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Sample records for resonance spectroscopy evaluates

  1. 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)

  2. Electron Paramagnetic Resonance Spectroscopy

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 20; Issue 11. Electron Paramagnetic Resonance Spectroscopy: Biological Applications. B G Hegde. General Article Volume 20 Issue 11 November 2015 pp 1017-1032. Fulltext. Click here to view fulltext PDF. Permanent link:

  3. 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.

  4. Neutron resonance spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Gunsing, F

    2005-06-15

    The present document has been written in order to obtain the diploma 'Habilitation a Diriger des Recherches'. Since this diploma is indispensable to supervise thesis students, I had the intention to write a document that can be useful for someone starting in the field of neutron resonance spectroscopy. Although the here described topics are already described elsewhere, and often in more detail, it seemed useful to have most of the relevant information in a single document. A general introduction places the topic of neutron-nucleus interaction in a nuclear physics context. The large variations of several orders of magnitude in neutron-induced reaction cross sections are explained in terms of nuclear level excitations. The random character of the resonances make nuclear model calculation predictions impossible. Then several fields in physics where neutron-induced reactions are important and to which I have contributed in some way or another, are mentioned in a first synthetic chapter. They concern topics like parity nonconservation in certain neutron resonances, stellar nucleosynthesis by neutron capture, and data for nuclear energy applications. The latter item is especially important for the transmutation of nuclear waste and for alternative fuel cycles. Nuclear data libraries are also briefly mentioned. A second chapter details the R-matrix theory. This formalism is the foundation of the description of the neutron-nucleus interaction and is present in all fields of neutron resonance spectroscopy. (author)

  5. Proton magnetic resonance spectroscopy and apparent diffusion coefficient in evaluation of solid brain lesions

    Directory of Open Access Journals (Sweden)

    Ristić-Baloš Dragana

    2013-01-01

    Full Text Available Background/Aim. Advanced magnetic resonance techniques can provide insight in physiological changes within pathological canges and contribute to better distinquishing between different tumor types and their discrimination from non-neoplastic lesions. The aim of this study was to evaluate the role of proton magnetic resonance spectroscopy (1H-MRS and apparent diffusion coefficients (ADC in distinguishing intracranial glial tumors from tumor like nonneoplastic lesions, as well as for differentiating high- from low-grade gliomas. Methods. This retrospective study included 47 patients with solid brain lesions (25 nonneoplastic, 14 low-grade and 8 anaplastic glial tumors. In all patients 1H-MRS (at a TE of 135 ms and 30 ms and diffusion- weighted imaging (DWI were performed. The choline to creatine (Cho/Cr, choline to N-acetyl aspartate (Cho/NAA, N-acetyl aspartate to creatine (NAA/Cr and myoinositol to creatine (mIn/Cr ratios and the apparent diffusion coefficient (ADC were determined. Results. The Cho/Cr ratio was significantly higher in glial tumors grade II than in non-neoplastic lesions (p = 0.008 and in glial tumors grade III than in non-neoplastic lesions (p = 0.001. The Cho/NAA ratio was significantly higher in glial tumors grade II than in non-neoplastic lesions (p = 0.037. ΔADC/ADC between glial tumors grade II and glial tumors grade III showed a statistical significance (p = 0.023. Conclusion. Our study showed that 1H-MRS and apparent diffusion coefficients can help in evaluation and differentiation of solid brain lesions.

  6. Magnetic Resonance Spectroscopy for Evaluating Portal-Systemic Encephalopathy in Patients with Chronic Hepatic Schistosomiasis Japonicum.

    Science.gov (United States)

    Li, Ying; Mei, Lihong; Qiang, Jinwei; Ju, Shuai; Zhao, Shuhui

    2016-12-01

    Portal-systemic encephalopathy (PSE) is classified as type B hepatic encephalopathy. Portal-systemic shunting rather than liver dysfunction is the main cause of PSE in chronic hepatic schistosomiasis japonicum (HSJ) patients. Owing to lack of detectable evidence of intrinsic liver disease, chronic HSJ patients with PSE are frequently clinically undetected or misdiagnosed, especially chronic HSJ patients with covert PSE (subclinical encephalopathy). In this study, we investigated whether magnetic resonance spectroscopy (MRS) could be a useful tool for diagnosing PSE in chronic HSJ patients. Magnetic resonance (MR) T1-weighted imaging, diffusion-weighted imaging, and MRS were performed in 41 chronic HSJ patients with suspected PSE and in 21 age-matched controls. The T1 signal intensity index (T1SI) and apparent diffusion coefficient (ADC) value were obtained in the Globus pallidus. Liver function was also investigated via serum ammonia and liver function tests. Higher T1SI and ADC values, increased lactate and glutamine levels, and decreased myo-inositol were found in the bilateral Globus pallidus in chronic HSJ patients with PSE. No significantly abnormal serum ammonia or liver function tests were observed in chronic HSJ patients with PSE. On the basis of these findings, we propose a diagnostic procedure for PSE in chronic HSJ patients. This study reveals that MRS can be useful for diagnosing PSE in chronic HSJ patients.

  7. Electron Paramagnetic Resonance Spectroscopy

    Indian Academy of Sciences (India)

    IAS Admin

    Recently, electron paramagnetic resonance (EPR) spectros- copy has emerged as a powerful tool to study the structure and dynamics of biological macromolecules such as proteins, protein aggregates, RNA and DNA. It is used in combination with molecular modelling to study complex systems such as soluble proteins ...

  8. Migraine and magnetic resonance spectroscopy

    DEFF Research Database (Denmark)

    Younis, Samaira; Hougaard, Anders; Vestergaard, Mark B.

    2017-01-01

    Purpose of review: To present an updated and streamlined overview of the metabolic and biochemical aspect of the migraine pathophysiology based on findings from phosphorous (31P) and hydrogen (1H) magnetic resonance spectroscopy (MRS) studies. Recent findings: Despite of the variation in the meth......Purpose of review: To present an updated and streamlined overview of the metabolic and biochemical aspect of the migraine pathophysiology based on findings from phosphorous (31P) and hydrogen (1H) magnetic resonance spectroscopy (MRS) studies. Recent findings: Despite of the variation...

  9. Nuclear Magnetic Resonance Spectroscopy

    Indian Academy of Sciences (India)

    protons and neutrons (both have a spin quantum number of 1/2) and the distribution of positive charge. NMR spectroscopy is most often concerned with nuclei with spin I = 1/2, examples of. Nuclei. Unpaired. Unpaired. Spin protons neutrons. IH. 1. 0. 1/2. 2H. 1. 1. 1 ..... tached to the oxygen in the COOH group. They are in ...

  10. Resonance Raman spectroscopy.

    Science.gov (United States)

    Li, Jiang; Kitagawa, Teizo

    2014-01-01

    Flavin is a general name given to molecules having the heteroaromatic ring system of 7,8-dimethylisoalloxazine but practically means riboflavin (Rfl), flavin adenine dinucleotide (FAD), and flavin mononucleotide (FMN) in biological systems, whose structures are illustrated in Fig. 1, together with the atomic numbering scheme and ring numbering of the isoalloxazine moiety. As the isoalloxazine skeleton cannot be synthesized in human cells, it is obtained from diet as Rfl (vitamin B2). FAD and FMN can act as cofactors in flavoenzymes but Rfl does not. Most flavoenzymes catalyze redox reactions of substrates (Miura, Chem Rec 1:183-194, 2001). When O2 serves as the oxidant in the oxidation half cycle of an enzymic reaction, the enzyme is called "flavo-oxidase" but when others do, the enzyme is called "flavo-dehydrogenase." The difference between the two types of oxidative catalysis arises from delicate differences in the π-electron distributions in the isoalloxazine ring, which can be revealed by Raman spectroscopy (Miura, Chem Rec 1:183-194, 2001). Since a flavin is an extremely versatile molecule, the scientific field including chemistry, biochemistry, and enzymology is collectively called "flavonology." It was found recently, however, that the flavin also acts as a chromophore to initiate light-induced DNA repair and signal transductions (Sancar, Chem Rev 103:2203-2237, 2003).

  11. Magnetic resonance imaging and proton magnetic resonance spectroscopy of the brain in the diagnostic evaluation of developmental delay

    NARCIS (Netherlands)

    Verbruggen, Krijn T.; Meiners, Linda C.; Sijens, Paul E.; Lunsing, Roelineke J.; van Spronsen, Francjan J.; Brouwer, Oebele F.

    Aim: To assess the contribution of MRI and proton spectroscopy (1HMRS) in establishing an etiological diagnosis in children with developmental delay (DD) and to assess whether the chance of finding specific abnormalities correlates with the presence of neurological signs and/or abnormal head

  12. Magnetic Resonance Spectroscopy of the Breast at 3T: Pre- and Post-Contrast Evaluation for Breast Lesion Characterization

    Directory of Open Access Journals (Sweden)

    E. Kousi

    2012-01-01

    Full Text Available Purpose. To determine whether in vivo proton magnetic resonance spectroscopy at 3T can provide accurate breast lesion characterization, and to determine the effect of gadolinium on the resonance of tCho. Methods. Twenty-four positive-mammogram patients were examined on a 3T MR scanner. 1H-MRS was performed before and after gadolinium administration. tCho peak was qualitatively evaluated before and after contrast injection. Results. Fourteen out of 27 lesions proved to be malignant after histopathological diagnosis. Using 1H-MRS, before contrast injection, 6/14 confirmed malignancies and 11/13 benign lesions were correctly classified; while, after contrast injection, 11/14 confirmed malignancies and 12/13 benign processes were correctly classified. Post gadolinium 1H-MRS proved useful in picking up tCho signal, improving the overall accuracy, sensitivity, and specificity by 35%, 83%, and 9%, respectively. Conclusion. 1H-MRS overall accuracy, sensitivity, and specificity in detecting breast lesion’s malignancy were increased after gadolinium administration. It is prudent to perform 1H-MRS before contrast injection in large breast lesions to avoid choline underestimation. In cases of small or non-mass lesions, it is recommended to perform 1H-MRS after contrast injection for better voxel prescription to enable a reliable preoperative diagnosis.

  13. Effects of electromagnetic radiation produced by 3G mobile phones on rat brains: magnetic resonance spectroscopy, biochemical, and histopathological evaluation.

    Science.gov (United States)

    Dogan, M; Turtay, M G; Oguzturk, H; Samdanci, E; Turkoz, Y; Tasdemir, S; Alkan, A; Bakir, S

    2012-06-01

    The effects of electromagnetic radiation (EMR) produced by a third-generation (3G) mobile phone (MP) on rat brain tissues were investigated in terms of magnetic resonance spectroscopy (MRS), biochemistry, and histopathological evaluations. The rats were randomly assigned to two groups: Group 1 is composed of 3G-EMR-exposed rats (n = 9) and Group 2 is the control group (n = 9). The first group was subjected to EMR for 20 days. The control group was not exposed to EMR. Choline (Cho), creatinin (Cr), and N-acetylaspartate (NAA) levels were evaluated by MRS. Catalase (CAT) and glutathione peroxidase (GSH-Px) enzyme activities were measured by spectrophotometric method. Histopathological analyses were carried out to evaluate apoptosis in the brain tissues of both groups. In MRS, NAA/Cr, Cho/Cr, and NAA/Cho ratios were not significantly different between Groups 1 and 2. Neither the oxidative stress parameters, CAT and GSH-Px, nor the number of apoptotic cells were significantly different between Groups 1 and 2. Usage of short-term 3G MP does not seem to have a harmful effect on rat brain tissue.

  14. Migraine and magnetic resonance spectroscopy

    DEFF Research Database (Denmark)

    Younis, Samaira; Hougaard, Anders; Vestergaard, Mark B.

    2017-01-01

    Purpose of review: To present an updated and streamlined overview of the metabolic and biochemical aspect of the migraine pathophysiology based on findings from phosphorous (31P) and hydrogen (1H) magnetic resonance spectroscopy (MRS) studies. Recent findings: Despite of the variation in the meth......Purpose of review: To present an updated and streamlined overview of the metabolic and biochemical aspect of the migraine pathophysiology based on findings from phosphorous (31P) and hydrogen (1H) magnetic resonance spectroscopy (MRS) studies. Recent findings: Despite of the variation...... in the methodology and quality of the MRS migraine studies over time, some results were consistent and reproducible. 31P-MRS studies suggested reduced availability of neuronal energy and implied a mitochondrial dysfunction in the migraine brain. 1H-MRS studies reported interictal abnormalities in the excitatory...... and inhibitory neurotransmitters, glutamate and g-aminobutyric acid (GABA), suggesting persistent altered excitability in migraine patients. N-Acetylaspartate levels were decreased in migraine, probably due to a mitochondrial dysfunction and abnormal energy metabolism. The reported abnormalities may increase...

  15. Resonance ionization spectroscopy in dysprosium

    Energy Technology Data Exchange (ETDEWEB)

    Studer, D., E-mail: dstuder@uni-mainz.de; Dyrauf, P.; Naubereit, P.; Heinke, R.; Wendt, K. [Johannes Gutenberg-Universität Mainz, Institut für Physik (Germany)

    2017-11-15

    We report on resonance ionization spectroscopy (RIS) of high-lying energy levels in dysprosium. We developed efficient excitation schemes and re-determined the first ionization potential (IP) via analysis of Rydberg convergences. For this purpose both two- and three-step excitation ladders were investigated. An overall ionization efficiency of 25(4) % could be demonstrated in the RISIKO mass separator of Mainz University, using a three-step resonance ionization scheme. Moreover, an extensive analysis of the even-parity 6sns- and 6snd-Rydberg-series convergences, measured via two-step excitation was performed. To account for strong perturbations in the observed s-series, the approach of multichannel quantum defect theory (MQDT) was applied. Considering all individual series limits we extracted an IP-value of 47901.76(5) cm{sup −1}, which agrees with the current literature value of 47901.7(6) cm{sup −1}, but is one order of magnitude more precise.

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

    DEFF Research Database (Denmark)

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

    2006-01-01

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

  17. Resonant photothermal IR spectroscopy of picogram samples with microstring resonator

    DEFF Research Database (Denmark)

    Yamada, Shoko; Schmid, Silvan; Boisen, Anja

    2013-01-01

    an in-situ sampling method and the resonance frequency of the string is measured optically. Resonance frequency shifts, proportional to the absorbed heat, are recorded in real time as monochromatic infrared light is being scanned over the mid-infrared range. These resonant photothermal IR spectroscopy...

  18. Quality evaluation and species differentiation of Rhizoma coptidis by using proton nuclear magnetic resonance spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Fan Gang [College of Ethnic Medicine, Chengdu University of Traditional Chinese Medicine, Chengdu 611137 (China); Zhang Mengying [China Agricultural University, Beijing 100094 (China); Zhou Xiangdong, E-mail: zhouxd88@yahoo.cn [Department of Medicinal Chemistry, College of Pharmacy, Third Military Medical University, Chongqing 400038 (China); Lai Xianrong; Yue Qinghong; Tang Ce [College of Ethnic Medicine, Chengdu University of Traditional Chinese Medicine, Chengdu 611137 (China); Luo Weizao [Chongqing Academy of Chinese Materia Medica, Chongqing 400065 (China); Zhang Yi, E-mail: tcmzhangyi@yahoo.cn [College of Ethnic Medicine, Chengdu University of Traditional Chinese Medicine, Chengdu 611137 (China)

    2012-10-17

    Highlights: Black-Right-Pointing-Pointer We report a qNMR method for the determination of six alkaloids in Rhizoma coptidis. Black-Right-Pointing-Pointer The results of the qNMR method are reliable by comparison with a HPLC method. Black-Right-Pointing-Pointer The proposed method has good selectivity, precision, repeatability and accuracy. Black-Right-Pointing-Pointer This method coupled with chemometrics can distinguish three Rhizoma coptidis species. - Abstract: Rhizoma coptidis, a broadly used traditional Chinese medicine, derives from the dried rhizomes of Coptis chinensis Franch, Coptis deltoidea C.Y. Cheng et Hsiao and Coptis teeta Wall. Quantitative determination of protoberberine alkaloids in R. coptidis is critical for controlling its quality. In this study, a rapid, simple and accurate quantitative {sup 1}H NMR (qNMR) method was developed for simultaneous determination of berberine, jatrorrhizine, epiberberine, coptisine, palmatine and columbamine in R. coptidis from the three species. Method validation was performed in terms of selectivity, precision, repeatability, stability, accuracy, robustness and linearity. The average recoveries obtained were in the range of 96.9-102.4% for all the six alkaloids. In addition, the qNMR data were analyzed with analysis of variance (ANOVA), hierarchical clustering analysis (HCA) and principal component analysis (PCA), and the results showed that the contents of the active alkaloids have significant difference among the three species. Compared with the conventional HPLC approach, the proposed qNMR method was demonstrated to be a powerful tool for quantifying the six alkaloids due to its unique advantages of high robustness, rapid analysis time and no need of standard compounds for calibration curves preparation. These findings indicate that this method has potential as a reliable method for quality evaluation of herb medicines, especially for protoberberine alkaloid-containing ones.

  19. 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)

  20. single voxel magnetic resonance spectroscopy in distinguishing

    African Journals Online (AJOL)

    2011-03-03

    Mar 3, 2011 ... magnetic resonance spectroscopy (MRI, MRS) in differentiating focal neoplastic lesions from focal non- neoplastic (infective or degenerative) brain lesions. Design: Descriptive, analytical - prospective study. Setting: The Aga Khan University MRI department. Subject: Seventy four consecutive patients.

  1. Resonant metallic nanostructures for enhanced terahertz spectroscopy

    KAUST Repository

    Toma, A.

    2015-11-12

    We present our recent studies on terahertz resonant dipole nanoantennas. Exploiting the localization and enhancement capabilities of these devices, we introduce an effective method to perform terahertz spectroscopy on an extremely small number of nano-objects.

  2. Nanometrology using localized surface plasmon resonance spectroscopy

    DEFF Research Database (Denmark)

    Jeppesen, Claus; Lindstedt, Daniel N.; Laurberg, Asger V.

    2013-01-01

    A novel optical characterization technique called localized surface plasmon resonance (LSPR) spectroscopy is presented. LSPR spectroscopy exploits light excited surface plasmons, which are collective coherent electron oscillations at a metal/dielectric interface. The LSPR can be observed in a tra...

  3. Single voxel magnetic resonance spectroscopy in distinguishing ...

    African Journals Online (AJOL)

    Objective: Assess diagnostic utility of combined magnetic resonance imaging and magnetic resonance spectroscopy (MRI, MRS) in differentiating focal neoplastic lesions from focal non- neoplastic (infective or degenerative) brain lesions. Design: Descriptive, analytical - prospective study. Setting: The Aga Khan University ...

  4. Triplet State Resonance Raman Spectroscopy

    DEFF Research Database (Denmark)

    Wilbrandt, Robert Walter; Jensen, N. H.; Pagsberg, Palle Bjørn

    1978-01-01

    Makes the first report on the resonance Raman spectrum of a molecule in its triplet state generated by pulse radiolysis. A solution of 0.01 mol dm-3 of p-terphenyl in benzene was studied......Makes the first report on the resonance Raman spectrum of a molecule in its triplet state generated by pulse radiolysis. A solution of 0.01 mol dm-3 of p-terphenyl in benzene was studied...

  5. Jet-associated resonance spectroscopy

    Science.gov (United States)

    Englert, Christoph; Ferretti, Gabriele; Spannowsky, Michael

    2017-12-01

    We present a model-independent study aimed at characterising the nature of possible resonances in the jet-photon or jet- Z final state at hadron colliders. Such resonances are expected in many models of compositeness and would be a clear indication of new physics. At leading order, in the narrow width approximation, the matrix elements are parameterised by just a few constants describing the coupling of the various helicities to the resonance. We present the full structure of such amplitudes up to spin 2 and use them to simulate relevant kinematic distributions that could serve to constrain the coupling structure. This also generalises the signal generation strategy that is currently pursued by ATLAS and CMS to the most general case in the considered channels. While the determination of the P/CP properties of the interaction seems to be out of reach within this framework, there is a wealth of information to be gained about the spin of the resonance and the relative couplings of the helicities.

  6. Evaluation of neuron-glia integrity by in vivo proton magnetic resonance spectroscopy: Implications for psychiatric disorders.

    Science.gov (United States)

    Xu, Haiyun; Zhang, Handi; Zhang, Jie; Huang, Qingjun; Shen, Zhiwei; Wu, Renhua

    2016-12-01

    Proton magnetic resonance spectroscopy (1H-MRS) has been widely applied in human studies. There is now a large literature describing findings of brain MRS studies with mental disorder patients including schizophrenia, bipolar disorder, major depressive disorder, and anxiety disorders. However, the findings are mixed and cannot be reconciled by any of the existing interpretations. Here we proposed the new theory of neuron-glia integrity to explain the findings of brain 1H-MRS stuies. It proposed the neurochemical correlates of neuron-astrocyte integrity and axon-myelin integrity on the basis of update of neurobiological knowledge about neuron-glia communication and of experimental MRS evidence for impairments in neuron-glia integrity from the authors and the other investigators. Following the neuron-glia integrity theories, this review collected evidence showing that glutamate/glutamine change is a good marker for impaired neuron-astrocyte integrity and that changes in N-acetylaspartate and lipid precursors reflect impaired myelination. Moreover, this new theory enables us to explain the differences between MRS findings in neuropsychiatric and neurodegenerative disorders. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

  7. Proton Resonance Spectroscopy -- Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Shriner, Jr., J. F. [Tennessee Technological Univ., Cookeville, TN (United States)

    2009-07-27

    This report summarizes work supported by the DOE Grant DE-FG02-96ER40990 during its duration from June 1996 to May 2009. Topics studied include (1) statistical descriptions of nuclear levels and measurements of proton resonances relevant to such descriptions, including measurements toward a complete level scheme for 30P, (2) the development of methods to estimate the missing fraction of levels in a given measurement, and (3) measurements at HRIBF relevant to nuclear astrophysics.

  8. 1H magnetic resonance spectroscopy in human hydrocephalus

    NARCIS (Netherlands)

    Braun, Kees P. J.; Gooskens, Rob H. J. M.; Vandertop, W. Peter; Tulleken, Cees A. F.; van der Grond, Jeroen

    2003-01-01

    PURPOSE: To evaluate cerebral metabolism in clinical hydrocephalus with (1)H magnetic resonance spectroscopy (MRS). MATERIALS AND METHODS: In 24 children and adults with progressive, arrested, or normal pressure hydrocephalus, long-echo time (1)H MR spectra were acquired from periventricular white

  9. Acute administration of epirubicin induces myocardial depression in isolated rat heart and production of radical species evaluated by electron spin resonance spectroscopy.

    Science.gov (United States)

    Delemasure, Stéphanie; Sicard, Pierre; Lauzier, Benjamin; Moreau, Daniel; Vergely, Catherine; Rochette, Luc

    2007-12-01

    The aim of our study was to evaluate the acute effect of epirubicin (EPI), an anthracycline anticancer drug, on the evolution of cardiac functional parameters and production of reactive oxygen/nitrogen species (RONS). Isolated perfused rat hearts were subjected to 70 minutes of EPI (10.3 microM) infusion and to 5 minutes of isoproterenol (ISO, 0.1 microM) at the end of the protocol. Coronary flow (CF), left ventricular developed pressure (LVDP), and lactate dehydrogenase (LDH) release in the coronary effluents were evaluated throughout the protocol. RONS were detected in the coronary effluents by electron spin resonance spectroscopy with a spin probe, 1-hydroxy-3-carboxy-pyrrolidine (CP-H, 0.1 mM). EPI induced a reduction in CF and in LVDP (P now needed to determine whether new cardioprotective agents targeting oxidative stress may reduce the incidence of anthracycline-induced cardiotoxicity.

  10. Perspective: Two-dimensional resonance Raman spectroscopy

    Science.gov (United States)

    Molesky, Brian P.; Guo, Zhenkun; Cheshire, Thomas P.; Moran, Andrew M.

    2016-11-01

    Two-dimensional resonance Raman (2DRR) spectroscopy has been developed for studies of photochemical reaction mechanisms and structural heterogeneity in complex systems. The 2DRR method can leverage electronic resonance enhancement to selectively probe chromophores embedded in complex environments (e.g., a cofactor in a protein). In addition, correlations between the two dimensions of the 2DRR spectrum reveal information that is not available in traditional Raman techniques. For example, distributions of reactant and product geometries can be correlated in systems that undergo chemical reactions on the femtosecond time scale. Structural heterogeneity in an ensemble may also be reflected in the 2D spectroscopic line shapes of both reactive and non-reactive systems. In this perspective article, these capabilities of 2DRR spectroscopy are discussed in the context of recent applications to the photodissociation reactions of triiodide and myoglobin. We also address key differences between the signal generation mechanisms for 2DRR and off-resonant 2D Raman spectroscopies. Most notably, it has been shown that these two techniques are subject to a tradeoff between sensitivity to anharmonicity and susceptibility to artifacts. Overall, recent experimental developments and applications of the 2DRR method suggest great potential for the future of the technique.

  11. Application of 3.0T magnetic resonance spectroscopy imaging in the evaluation on the development of normal brain white matter in infants and young children

    Directory of Open Access Journals (Sweden)

    Wen-li XU

    2014-01-01

    Full Text Available Objective To calculate the radios of peak area of proton magnetic resonance spectroscopy metabolites in brain white matter of normal infants and young children, to observe the features of metabolite spectra, and to explore the relations between their ratio with age. Methods The peak areas of metabolites, including N-acetyl aspartate (NAA, choline (Cho, creatine (Cr, and their ratio of NAA/Cho, NAA/Cr, Cho/Cr, in paraventricular white matter of 180 normal infants and young children with different ages as evaluated by multi-voxel proton magnetic resonance spectroscopy. Results In paraventricular white matter, spectrum of NAA increased, and that of Cho decreased gradually, while both of them were stabilized at 2 years old. Cr was increased obviously within 3 months, and stabilized after 4 months. Significant differences were found in ratio of different metabolites in paraventricular white matter in different ages (P<0.05. The ratios of NAA/Cho and NAA/Cr in paraventricular white mater were positively correlated with age (r=0.741, r=0.625, while that of Cho/Cr was negatively correlated with age (r=–0.552, P<0.05. Conclusion The ratios of different metabolites are different in brain white matter in infants of different ages. Metabolites concentrations in brain white matter are correlated to some extent with age, which may provide a diagnostic criterion for evaluation of normal brain development and abnormal brain metabolism. DOI: 10.11855/j.issn.0577-7402.2013.12.05

  12. Magnetic resonance spectroscopy of the human brain

    Science.gov (United States)

    Strózik-Kotlorz, D.

    2014-01-01

    I give a brief description of the magnetic resonance spectroscopy (MRS) in the human brain examinations. MRS allows a noninvasive chemical analysis of the brain using a standard high field MR system. Nowadays, the dominant form of MR brain spectroscopy is proton spectroscopy. Two main techniques of MRS, which utilize the chemical shift of metabolites in the external magnetic field, are SVS (single voxel) and CSI (single slice). The major peaks in the spectrum of a normal brain include NAA, Cr, Cho and m-Ins, which are neuronal, energetic, membrane turnover and glial markers, respectively. In disease, two pathological metabolites can be found in the brain spectra: Lac, which is end product of anaerobic glycolysis and Lip, which is a marker of membrane breakdown, occurring in necrosis. The common way to analyze clinical spectra is to determine metabolite ratios, e.g. NAA/Cr, Cho/Cr, Cho/NAA. This analysis permits a safe and noninvasive examination of the brain tissue as each disease state has its own characteristic spectroscopic image. MRS is a valuable diagnostic tool in such clinical applications as detecting brain tumors and differentiating tumors from inflammatory and infectious processes. Proton MRS is also very helpful in diagnostic of ischemic lesions, Alzheimer's disease and hepatic encephalopathy. The MRS brain spectra should always be correlated with the Magnetic Resonance Imaging (MRI) results and alone cannot make neurological diagnosis.

  13. Breast Tissue Metabolism by Magnetic Resonance Spectroscopy.

    Science.gov (United States)

    Jagannathan, Naranamangalam R; Sharma, Uma

    2017-06-07

    Metabolic alterations are known to occur with oncogenesis and tumor progression. During malignant transformation, the metabolism of cells and tissues is altered. Cancer metabolism can be studied using advanced technologies that detect both metabolites and metabolic activities. Identification, characterization, and quantification of metabolites (metabolomics) are important for metabolic analysis and are usually done by nuclear magnetic resonance (NMR) or by mass spectrometry. In contrast to the magnetic resonance imaging that is used to monitor the tumor morphology during progression of the disease and during therapy, in vivo NMR spectroscopy is used to study and monitor tumor metabolism of cells/tissues by detection of various biochemicals or metabolites involved in various metabolic pathways. Several in vivo, in vitro and ex vivo NMR studies using ¹H and 31P magnetic resonance spectroscopy (MRS) nuclei have documented increased levels of total choline containing compounds, phosphomonoesters and phosphodiesters in human breast cancer tissues, which is indicative of altered choline and phospholipid metabolism. These levels get reversed with successful treatment. Another method that increases the sensitivity of substrate detection by using nuclear spin hyperpolarization of 13C-lableled substrates by dynamic nuclear polarization has revived a great interest in the study of cancer metabolism. This review discusses breast tissue metabolism studied by various NMR/MRS methods.

  14. Breast Tissue Metabolism by Magnetic Resonance Spectroscopy

    Directory of Open Access Journals (Sweden)

    Naranamangalam R. Jagannathan

    2017-06-01

    Full Text Available Metabolic alterations are known to occur with oncogenesis and tumor progression. During malignant transformation, the metabolism of cells and tissues is altered. Cancer metabolism can be studied using advanced technologies that detect both metabolites and metabolic activities. Identification, characterization, and quantification of metabolites (metabolomics are important for metabolic analysis and are usually done by nuclear magnetic resonance (NMR or by mass spectrometry. In contrast to the magnetic resonance imaging that is used to monitor the tumor morphology during progression of the disease and during therapy, in vivo NMR spectroscopy is used to study and monitor tumor metabolism of cells/tissues by detection of various biochemicals or metabolites involved in various metabolic pathways. Several in vivo, in vitro and ex vivo NMR studies using 1H and 31P magnetic resonance spectroscopy (MRS nuclei have documented increased levels of total choline containing compounds, phosphomonoesters and phosphodiesters in human breast cancer tissues, which is indicative of altered choline and phospholipid metabolism. These levels get reversed with successful treatment. Another method that increases the sensitivity of substrate detection by using nuclear spin hyperpolarization of 13C-lableled substrates by dynamic nuclear polarization has revived a great interest in the study of cancer metabolism. This review discusses breast tissue metabolism studied by various NMR/MRS methods.

  15. Breast Tissue Metabolism by Magnetic Resonance Spectroscopy

    Science.gov (United States)

    Jagannathan, Naranamangalam R.; Sharma, Uma

    2017-01-01

    Metabolic alterations are known to occur with oncogenesis and tumor progression. During malignant transformation, the metabolism of cells and tissues is altered. Cancer metabolism can be studied using advanced technologies that detect both metabolites and metabolic activities. Identification, characterization, and quantification of metabolites (metabolomics) are important for metabolic analysis and are usually done by nuclear magnetic resonance (NMR) or by mass spectrometry. In contrast to the magnetic resonance imaging that is used to monitor the tumor morphology during progression of the disease and during therapy, in vivo NMR spectroscopy is used to study and monitor tumor metabolism of cells/tissues by detection of various biochemicals or metabolites involved in various metabolic pathways. Several in vivo, in vitro and ex vivo NMR studies using 1H and 31P magnetic resonance spectroscopy (MRS) nuclei have documented increased levels of total choline containing compounds, phosphomonoesters and phosphodiesters in human breast cancer tissues, which is indicative of altered choline and phospholipid metabolism. These levels get reversed with successful treatment. Another method that increases the sensitivity of substrate detection by using nuclear spin hyperpolarization of 13C-lableled substrates by dynamic nuclear polarization has revived a great interest in the study of cancer metabolism. This review discusses breast tissue metabolism studied by various NMR/MRS methods. PMID:28590405

  16. Proton magnetic resonance spectroscopy and perfusion magnetic resonance imaging in the evaluation of musculoskeletal tumors; Espectroscopia de protons e perfusao por ressonancia magnetica na avaliacao dos tumores do sistema musculoesqueletico

    Energy Technology Data Exchange (ETDEWEB)

    Costa, Flavia Martins; Setti, Marcela [Clinica de Diagnostico Por Imagem (CDPI), Rio de Janeiro, RJ (Brazil)], e-mail: flavia26rio@hotmail.com; Vianna, Evandro Miguelote; Domingues, Romulo Cortes [Clinica de Diagnostico Por Imagem (CDPI), Rio de Janeiro, RJ (Brazil); Multi-Imagem, Rio de Janeiro, RJ (Brazil); Meohas, Walter; Rezende, Jose Francisco [Instituto Nacional de Cancer (INCA), Rio de Janeiro, RJ (Brazil); Gasparetto, Emerson Leandro [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil); Clinica de Diagnostico Por Imagem (CDPI), Rio de Janeiro, RJ (Brazil)

    2009-07-15

    Objective: To assess the role of proton magnetic resonance spectroscopy and dynamic contrast-enhanced magnetic resonance imaging in the differentiation between malignant and benign musculoskeletal tumors. Materials And Methods: Fifty-five patients with musculoskeletal tumors (27 malignant and 28 benign) were studied. The examinations were performed in a 1.5 T magnetic resonance scanner with standard protocol, and single voxel proton magnetic resonance spectroscopy with 135 msec echo time. The dynamic contrast study was performed using T1-weighted gradient-echo sequence after intravenous gadolinium injection. Time signal intensity curves and slope values were calculated. The statistical analysis was performed with the Levene's test, followed by a Student's t-test, besides the Pearson's chi-squared and Fischer's exact tests. Results: Proton magnetic resonance spectroscopy sensitivity, specificity and accuracy were, respectively, 87.5%, 92.3% and 90.9% (p < 0.0001). Statistically significant difference was observed in the slope (%/min) between benign (mean, 27.5%/min) and malignant (mean, 110.9%/min) lesions (p < 0.0001). Conclusion: The time-intensity curve and slope values using dynamic-enhanced perfusion magnetic resonance imaging in association with the presence of choline peak demonstrated by single voxel magnetic resonance spectroscopy study are useful in the differentiation between malignant and benign musculoskeletal tumors. (author)

  17. Magnetic resonance spectroscopy studies in migraine

    Energy Technology Data Exchange (ETDEWEB)

    Montagna, P.; Cortelli, P.; Barbiroli, B. (Inst. of Medical Pathology, Univ. of Bologna (Italy))

    1994-06-01

    The authors describe the method of [sup 31]phosphorus magnetic resonance spectroscopy and review the results when it is applied to the study of brain and muscle energy metabolism in migraine subjects. Brain energy metabolism appears to be abnormal in all major subtypes of migraine when measured both during and between attacks. Impaired energy metabolism is also documented in skeletal muscle. It is suggested that migraine is associated with a generalized disorder of mitochondrial oxidative phosphorylation and that this may constitute a threshold for the triggering of migraine attacks. 47 refs., 10 figs., 3 tabs.

  18. Role of proton magnetic resonance spectroscopy in diagnosis of ...

    African Journals Online (AJOL)

    Magnetic resonance (MR) imaging was performed at 1.5 Tesla MR system using a standard head coil. Imaging included conventional MRI and proton magnetic resonance spectroscopy. Proton magnetic resonance spectroscopy was done using either single or multi-voxel technique. Surgical biopsy was then performed to ...

  19. Magnetic resonance spectroscopy in cancer diagnostics

    Directory of Open Access Journals (Sweden)

    Ana Margarida Abrantes

    2011-12-01

    Full Text Available Magnetic resonance spectroscopy (MRS is one of the most powerful analytical techniques, being frequently used to derive physical, chemical, electronic, and structural information about molecules. Considering its potentialities and its evolution as cell/tissue response predictor, it can be used to detect changes in the tumor pathophysiology before, during, and after treatment. Of particular relevance to this analysis, due to its higher sensitivity, is proton magnetic resonance spectroscopy (1H-MRS either applied directly in vivo or by using tumor biopsies and high-rotation magic angle spinning (HRMAS. Several metabolites have been quantified in several tumors, including creatine and phosphocreatine, choline, lactate and myoinositol, and used for distinguishing different cancer types. Several advantages characterize this technique including swiftness and ability to support the characterization of tumoral lesions on the basis of their biochemical composition, which may provide additional diagnostic and prognostic information as an adjunct to routine histological assessment. Many tumors have already been studied by 1H-MRS, and there is growing interest in studying others in order to establish extended metabolite databases which could help in their identification and characterization.

  20. Historical survey of resonance ionization spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Hurst, G.S.

    1984-04-01

    We have recently celebrated the 10th birthday of Resonance Ionization Spectroscopy (RIS), and this seems an appropriate time to review the history of its development. Basically, RIS is a photophysics process in which tunable light sources are used to remove a valence electron from an atom of selected atomic number, Z. If appropriate lasers are used as the light source, one electron can be removed from each atom of the selected Z in the laser pulse. This implies that RIS can be a very efficient, as well as selective, ionization process. In what we normally call RIS, laser schemes are employed which preserve both of these features. In contrast, multiphoton ionization (MPI) is more general, although not necessarily Z selective or very efficient because resonances are often not used. Early research completed in the USSR and described as selective two-step photoionization, employed resonances to ionize the rubidium atom and served to guide work on laser isotope separation. 29 references, 8 figures.

  1. Evaluation of epileptogenic focus in temporal lobe: correlation between ictal brain SPECT, magnetic resonance imaging and magnetic resonance spectroscopy; Avaliacao de foco epileptogenico do lobo temporal: correlacao entre SPECT ictal, ressonancia magnetica e ressonancia magnetica com espectroscopia de protons

    Energy Technology Data Exchange (ETDEWEB)

    Diegues, Maria Elena Martins [Hospital Universitario Clementino Fraga Filho, Rio de Janeiro, RJ (Brazil). Servico de Medicina Nuclear]. E-mail: emartyns@terra.com.br; Pellini, Marcos Pinto; Alves-Leon, Soniza Vieira [Universidade Federal, Rio de Janeiro, RJ (Brazil). Faculdade de Medicina; Domingues, Romeu Cortes [Clinica de Diagnostico por Imagem (CDPI), Rio de Janeiro, RJ (Brazil)

    2004-02-01

    The purpose of this study was to determine the degree of concordance between radiological and radioisotopic methods and, if positive, to evaluate the usefulness of ictal SPECT in the localization of the epileptogenic focus. Ictal brain SPECT, magnetic resonance imaging (MRI) and magnetic resonance spectroscopy (MRS) were performed on six patients with refractory temporal lobe epilepsy. Ictal SPECT was performed after withdrawal of the anti-epileptogenic drugs during video-EEG monitoring, using {sup 99m}Tc-ECD, administered to patients at the time of the ictus. MRI was performed in T1, T2 and FLAIR sequences and MRS was obtained using the PRESS technique, with a single voxel positioned in both hippocampi. The statistical analysis included the determination of the values of Kappa (k), standard error (se) and significance level (p) for the lateralization of the ictal focus. The analysis of all findings was based on EEG localization of the ictal discharge, seizure duration (109-280 s; 152 s average) and time of radiotracer injection (30-262 s; 96 s average). We obtained correlated data in four patients (67 per cent) and values of k = 0.67, se = 0.38, and p 0.041. We concluded that there is a concordance between ictal SPECT, MRI and MRS data and the usefulness of the radioisotopic procedure is related to a non diagnostic EEG and when there is a discordant or misleading diagnosis after a comparative analysis of EEG and MRS. (author)

  2. Resonant Raman spectroscopy of twisted multilayer graphene

    Science.gov (United States)

    Wu, Jiang-Bin; Zhang, Xin; Ijäs, Mari; Han, Wen-Peng; Qiao, Xiao-Fen; Li, Xiao-Li; Jiang, De-Sheng; Ferrari, Andrea C.; Tan, Ping-Heng

    2014-11-01

    Graphene and other two-dimensional crystals can be combined to form various hybrids and heterostructures, creating materials on demand with properties determined by the interlayer interaction. This is the case even for a single material, where multilayer stacks with different relative orientation have different optical and electronic properties. Probing and understanding the interface coupling is thus of primary importance for fundamental science and applications. Here we study twisted multilayer graphene flakes with multi-wavelength Raman spectroscopy. We find a significant intensity enhancement of the interlayer coupling modes (C peaks) due to resonance with new optically allowed electronic transitions, determined by the relative orientation of the layers. The interlayer coupling results in a Davydov splitting of the C peak in systems consisting of two equivalent graphene multilayers. This allows us to directly quantify the interlayer interaction, which is much smaller compared with Bernal-stacked interfaces. This paves the way to the use of Raman spectroscopy to uncover the interface coupling of two-dimensional hybrids and heterostructures.

  3. Electronic resonances in broadband stimulated Raman spectroscopy

    Science.gov (United States)

    Batignani, G.; Pontecorvo, E.; Giovannetti, G.; Ferrante, C.; Fumero, G.; Scopigno, T.

    2016-01-01

    Spontaneous Raman spectroscopy is a formidable tool to probe molecular vibrations. Under electronic resonance conditions, the cross section can be selectively enhanced enabling structural sensitivity to specific chromophores and reaction centers. The addition of an ultrashort, broadband femtosecond pulse to the excitation field allows for coherent stimulation of diverse molecular vibrations. Within such a scheme, vibrational spectra are engraved onto a highly directional field, and can be heterodyne detected overwhelming fluorescence and other incoherent signals. At variance with spontaneous resonance Raman, however, interpreting the spectral information is not straightforward, due to the manifold of field interactions concurring to the third order nonlinear response. Taking as an example vibrational spectra of heme proteins excited in the Soret band, we introduce a general approach to extract the stimulated Raman excitation profiles from complex spectral lineshapes. Specifically, by a quantum treatment of the matter through density matrix description of the third order nonlinear polarization, we identify the contributions which generate the Raman bands, by taking into account for the cross section of each process.

  4. Evaluation of six-point modified dixon and magnetic resonance spectroscopy for fat quantification: a fat-water-iron phantom study.

    Science.gov (United States)

    Fukuzawa, Kei; Hayashi, Tatsuya; Takahashi, Junji; Yoshihara, Chiharu; Tano, Masakatsu; Kotoku, Jun'ichi; Saitoh, Satoshi

    2017-09-01

    This study aimed to evaluate (1) the agreement between the true fat fraction (FF) and proton density FF (PDFF) measured using a six-echo modified Dixon (6mDixon) and magnetic resonance spectroscopy (MRS) and (2) the influence of fat on T2* values. The study was performed using phantoms of varying fat and iron content. Point-resolved spectroscopy (PRESS) and stimulated echo acquisition mode (STEAM) with single-echo (S) and multiecho (M) (PRESS-S, PRESS-M, STEAM-S, and STEAM-M) were used for MRS. In phantoms without iron, the agreement between the true FF and measured PDFF was tested using Bland-Altman analysis. The influence of iron on PDFF was evaluated in phantoms with iron. The relationship between the true FF and T2* value was assessed in phantoms without iron, wherein the mean differences (limits of agreement) for each method were as follows: 6mDixon 2.9% (-2.4 to 8.1%); STEAM-S 3.2% (-9.5 to 16.0%); STEAM-M -0.7% (-6.9 to 5.5%); PRESS-S 8.9% (-14.5 to 32.4%); and PRESS-M -5.8% (-18.3 to 6.7%). In the 20% fat phantoms with iron, as iron increased, PDFFs with STEAM-S, PRESS-S, and PRESS-M were considerably overestimated, while, PDFF with STEAM-M was stable at 0.04-0.2 mM iron concentrations (17.2 and 21.4%, respectively), and PDFF with 6mDixon was reliable at even 0.4 mM iron concentration (24.8%). The T2* value showed a negative correlation with the true FF (r = -0.942, P = 0.005). STEAM-M and 6mDixon were reliable methods of fat quantification in the absence of iron, and the T2* value was shortened by fat.

  5. Magnetic resonance spectroscopy as a diagnostic modality for carcinoma thyroid

    Energy Technology Data Exchange (ETDEWEB)

    Gupta, Nikhil [Department of Surgery, Maulana Azad Medical College, Lok Nayak Hospital, New Delhi (India)], E-mail: nikhil_ms26@yahoo.co.in; Kakar, Arun K. [Department of Surgery, Maulana Azad Medical College, Lok Nayak Hospital, New Delhi (India); Chowdhury, Veena [Department of Radiodiagnosis, Maulana Azad Medical College, Lok Nayak Hospital, New Delhi (India); Gulati, Praveen [MR Centre, A-23 Green Park, New Delhi (India); Shankar, L. Ravi [Department of Radioiodine Uptake and Imaging, Institute of Nucler Medicine and Allied Sciences (INMAS), Timarpur, New Delhi (India); Vindal, Anubhav [Department of Surgery, Maulana Azad Medical College, Lok Nayak Hospital, New Delhi (India)

    2007-12-15

    Aim: The aim of this study was to observe the findings of magnetic resonance spectroscopy of solitary thyroid nodules and its correlation with histopathology. Materials and methods: In this study, magnetic resonance spectroscopy was carried out on 26 patients having solitary thyroid nodules. Magnetic resonance spectroscopy (MRS) was performed on a 1.5 T super conductive system with gradient strength of 33 mTs. Fine needle aspiration cytology was done after MRS. All 26 patients underwent surgery either because of cytopathologically proven malignancy or because of cosmetic reasons. Findings of magnetic resonance spectroscopy were compared with histopathology of thyroid specimens. Results and conclusion: It was seen that presence or absence of choline peak correlates very well with presence or absence of malignant foci with in the nodule (sensitivity = 100%; specificity = 88.88%). These results indicate that magnetic resonance spectroscopy may prove to be an useful diagnostic modality for carcinoma thyroid.

  6. Neutron resonance spectroscopy at n-TOF at CERN

    Energy Technology Data Exchange (ETDEWEB)

    Gunsing, F.; Abbondanno, U.; Aerts, G.; Alvarez, H.; Alvarez-Velarde, F.; Andriamonje, S.; Andrzejewski, J.; Assimakopoulos, P.; Audouin, L.; Badurek, G.; Baumann, P.; Becvar, F.; Berthoumieux, E.; Calvino, F.; Calviani, M.; Cano-Ott, D.; Capote, R.; Carrapic, C.; Cennini, P.; Chepel, V.; Chiaveri, E.; Colonna, N.; Cortes, G.; Couture, A.; Cox, J.; Dahlfors, M.; David, S.; Dillmann, I.; Domingo-Pardo, C.; Dridi, W.; Duran, I.; Eleftheriadis, C.; Embid-Segura, M.; Ferrant, L.; Ferrari, A.; Ferreira-Marques, R.; Fujii, K.; Furman, W.; Goncalves, I.; Gonzalez-Romero, E.; Gramegna, F.; Guerrero, C.; Haas, B.; Haight, R.; Heil, M.; Herrera-Martinez, A.; Igashira, M.; Jericha, E.; Kappeler, F.; Kadi, Y.; Karadimos, D.; Karamanis, D.; Kerveno, M.; Koehler, P.; Kossionides, E.; Krticka, M.; Lampoudis, C.; Leeb, H.; Lindote, A.; Lopes, I.; Lozano, M.; Lukic, S.; Marganiec, J.; Marrone, S.; Martinez, T.; Massimi, C.; Mastinu, P.; Mengoni, A.; Milazzo, P.M.; Moreau, C.; Mosconi, M.; Neves, F.; Oberhummer, H.; O' Brien, S.; Pancin, J.; Papachristodoulou, C.; Papadopoulos, C.; Paradela, C.; Patronis, N.; Pavlik, A.; Pavlopoulos, P.; Perrot, L.; Pigni, M.T.; Plag, R.; Plompen, A.; Plukis, A.; Poch, A.; Praena, J.; Pretel, C.; Quesada, J.; Rauscher, T.; Reifarth, R.; Rubbia, C.; Rudolf, G.; Rullhusen, P.; Salgado, J.; Santos, C.; Sarchiapone, L.; Savvidis, I.; Stephan, C.; Tagliente, G.; Tain, J.L.; Tassan-Got, L.; Tavora, L.; Terlizzi, R.; Vannini, G.; Vaz, P.; Ventura, A.; Villamarin, D.; Vincente, M.C.; Vlachoudis, V.; Vlastou, R.; Voss, F.; Walter, S.; Wiescher, M.; Wisshak, K

    2008-07-01

    Neutron resonance spectroscopy plays an important role in the investigation of neutron induced reaction cross sections and nuclear structure in the MeV excitation range. Neutron time-of-flight facilities are the most used installations to explore neutron resonances. In this paper we describe the basic features of neutron resonance spectroscopy together with recent results from the time-of-flight facility n-TOF at CERN. (authors)

  7. Evaluation of intracranial neoplasia and noninfectious meningoencephalitis in dogs by use of short echo time, single voxel proton magnetic resonance spectroscopy at 3.0 Tesla.

    Science.gov (United States)

    Carrera, Inés; Richter, Henning; Beckmann, Katrin; Meier, Dieter; Dennler, Matthias; Kircher, Patrick R

    2016-05-01

    OBJECTIVE To investigate metabolite concentrations of the brains of dogs with intracranial neoplasia or noninfectious meningoencephalitis by use of short echo time, single voxel proton magnetic resonance spectroscopy ((1)H MRS) at 3.0 T. ANIMALS 29 dogs with intracranial lesions (14 with neoplasia [3 oligodendromas, 3 glioblastomas multiformes, 3 astrocytomas, 2 lymphomas, and 3 meningiomas] and 15 is with noninfectious meningoencephalitis) and 10 healthy control dogs. PROCEDURES Short echo time, single voxel (1)H-MRS at 3.0 T was performed on neoplastic and noninfectious inflammatory intracranial lesions identified with conventional MRI. Metabolites of interest included N-acetyl aspartate (NAA), total choline, creatine, myoinositol, the glutamine-glutamate complex (Glx), glutathione, taurine, lactate, and lipids. Data were analyzed with postprocessing fitting algorithm software. Metabolite concentrations relative to brain water content were calculated and compared with results for the healthy control dogs, which had been previously evaluated with the same (1)H MRS technique. RESULTS NAA, creatine, and Glx concentrations were reduced in the brains of dogs with neoplasia and noninfectious meningoencephalitis, whereas choline concentration was increased. Concentrations of these metabolites differed significantly between dogs with neoplasia and dogs with noninfectious meningoencephalitis. Concentrations of NAA, creatine, and Glx were significantly lower in dogs with neoplasia, whereas the concentration of choline was significantly higher in dogs with neoplasia. Lipids were predominantly found in dogs with high-grade intra-axial neoplasia, meningioma, and necrotizing meningoencephalitis. A high concentration of taurine was found in 10 of 15 dogs with noninfectious meningoencephalitis. CONCLUSIONS AND CLINICAL RELEVANCE (1)H MRS provided additional metabolic information about intracranial neoplasia and noninfectious meningoencephalitis in dogs.

  8. Can magnetic resonance spectroscopy differentiate endometrial cancer?

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Jie; Cai, Shifeng; Han, Xue; Liu, Qingwei; Xin, Yinghui [Shandong University, Department of Radiology, Shandong Provincial Hospital, Jinan (China); Li, Changzhong; Yang, Chunrun [Shandong University, Department of Obstetrics and Gynecology, Shandong Provincial Hospital, Jinan (China); Sun, Xichao; Zong, Yuanyuan [Shandong University, Department of Pathology, Shandong Provincial Hospital, Jinan (China); Fu, Caixia [Siemens Shenzhen Magnetic Resonance Ltd., Siemens MRI Center, Shenzhen (China)

    2014-10-15

    To investigate whether the choline-containing compounds (Cho) obtained from three-dimensional {sup 1}H magnetic resonance (MR) spectroscopy can differentiate endometrial cancer (ECa) from benign lesions in endometria or in submucosa (BLs-ESm) and is associated with the aggressiveness of ECa. Fifty-seven patients (ECa, 38; BLs-ESm, 19) underwent preoperative multi-voxel MR spectroscopy at 3.0 T. The ratio of the sum of the Cho peak integral to the sum of the unsuppressed water peak integral (Cho/water) and the coefficient of variation (CV) used to describe the variability of Cho/water in one lesion were calculated. Mean Cho/water (±standard deviation [SD]) was (3.02 ± 1.43) x 10{sup -3} for ECa and (1.68 ± 0.33) x 10{sup -3} for BLs-ESm (p < 0.001). Mean Cho/water was (4.42 ± 1.53) x 10{sup -3} for type II ECa and (2.65 ± 1.17) x 10{sup -3} for type I ECa (p = 0.001). There were no significant differences among different stages of ECa (p = 0.107) or different grades of ECa (p = 0.142). The Cho/water was positively correlated with tumour stage (r = 0.386, p = 0.017) and size (r = 0.333, p = 0.041). The CV was also positively correlated with tumour stage (r = 0.537, p = 0.001) and size (r = 0.34, p = 0.037). The Cho/water can differentiate ECa from BLs-ESm and differentiate type II from type I ECa, but cannot differentiate different stages of ECa or different grades of ECa. Cho/water increased with the increase of tumour stage and size. (orig.)

  9. Collinear resonance ionization spectroscopy of radium ions

    CERN Multimedia

    We propose to study the neutron-deficient radium isotopes with high-resolution collinear resonance ionization spectroscopy. Probing the hyperfine structure of the $7{s}\\,^2\\!{S}\\!_{1/2}\\,\\rightarrow\\,7{p}\\,^{2}\\!{P}\\!_{1/2}$ and $7{s}\\,^{2}\\!{S}\\!_{1/2}\\,\\rightarrow\\,7{p}\\,^{2}\\!{P}\\!_{3/2}$ transitions in Ra II will provide atomic-structure measurements that have not been achieved for $^{{A}<208}$Ra. Measurement of the $7{s}\\,^{2}\\!{S}\\!_{1/2}\\,\\rightarrow\\,7{p}\\,^{2}\\!{P}\\!_{3/2}$ transition in $^{{A}<214}$Ra will allow the spectroscopic quadrupole moments to be directly measured for the first time. In addition, the technique will allow tentative spin assignments to be confirmed and the magnetic dipole moments measured for $^{\\textit{A}<208}$Ra. Measurement of the hyperfine structure (in particular the isotope shifts) of the neutron-deficient radium will provide information to further constrain the nuclear models away from the N=126 shell closure.

  10. Resonant Raman spectroscopy on InN

    Energy Technology Data Exchange (ETDEWEB)

    Kuball, M.; Pomeroy, J.W. [H. H. Wills Physics Laboratory, University of Bristol, Bristol BS8 1TL (United Kingdom); Wintrebert-Fouquet, M.; Butcher, K.S.A. [Department of Physics, Macquarie University, Sydney NSW 2109 (Australia); Lu, Hai; Schaff, W.J. [Department of Electrical Engineering, Cornell University, Ithaca NY 14507 (United States); Shubina, T.V.; Ivanov, S.V. [Ioffe Physico-Technical Institute, St. Petersburg 194021 (Russian Federation); Vasson, A.; Leymarie, J. [LASMEA-UMR 6602 UBP/CNRS, University of Clermont-Ferrand II, F-63177 Aubiere Cedex (France)

    2005-04-01

    The novel use of resonant Raman spectroscopy to elucidate the band gap of InN is illustrated in a study of MBE-grown films. This technique can distinguish between electronic transitions related to the InN from transitions related to defects and impurities that are so typical for current InN material. Using excitation energies from 1.49 eV (830 nm) to 2.54 eV (488 nm), we identify a critical point in the InN band structure within {approx}200-300 meV below 1.5 eV. The origin of this critical point, whether band gap or higher critical point, is discussed. Furthermore, Raman results are presented on the temperature dependence of the InN phonons. Analysis of the data provides information on phonon lifetimes and decay mechanisms, important to assess whether hot phonon effects need to be considered in future InN devices. (copyright 2005 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  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. The effect of gingko biloba extract on energy metabolic status in C3H mouse fibrosarcoma: evaluated by in vivo {sup 31}P magnetic resonance spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Ha, Sung Whan; Kim, Won Dong; Ahn, Yong Chan; Park, Charn Il [Seoul National University, College of Medicine, Seoul (Korea, Republic of); Lim, Tae Hwan; Lee, Tae Kuen [Ulsan University, Seoul (Korea, Republic of)

    2002-06-15

    Gingko biloba extract (GBE), a natural product extracted from Gingko leaves, is known to increase the radiosensitivity of tumors. This radiosensitization probably arises from the increase in the peripheral blood flow by decreasing the blood viscosity and relaxing the vasospasm. The influence of a GBE on the metabolic status in fibrosarcoma II (FSall) of a C3H mouse was investigated using {sup 31}P magnetic resonance spectroscopy (MRS). Eighteen C3H mice with fibrosarcoma II (from 100 mm{sup 3} to 130 mm{sup 3}) were prepared for this experiment. The mice were divided into 2 groups; one (9 mice) without a priming dose, and the other (9 mice) with a priming dose of GBE. The GBE priming dose (100 mg/kg) was administered by an intraperitoneal (i.p.) injection 24 hours prior to the measurement. First {sup 31}P MRS spectra were measured in the mice from each group as a baseline and test dose of GBE (100 mg/kg) was then administered to each group. One hour later, the {sup 31}P MRS spectra were measured again to evaluate the change in the energy metabolic status. In the group without the priming dose, the mean pH, PCr/Pi, PME/ATP, Pi/ATP, PCr/(Pi + PME) values 1 hour after the test dose were not changed significantly compared to the values at the baseline. However, in the group with the priming dose, the mean PCr/Pi, Pi/ATP, PCr/(Pi + PME) values 1 hour after the test dose changed from the baseline values of 0.49, 0.77, 0.17 to 0.74, 0.57, 0.28 respectively. According to the paired t-test, the differences were statistically significant. The above findings suggest that the metabolic status is significantly improved after administering GBE if the priming dose is given 24 hours earlier. This shows that the radiosensitizing effect of GBE is based on the increase of tumor blood flow and the improvement in the metabolic status.

  13. Coherent Excitation-Selective Spectroscopy of Multipole Resonances

    Science.gov (United States)

    Fang, Xu; Tseng, Ming Lun; Tsai, Din Ping; Zheludev, Nikolay I.

    2016-01-01

    Thin films of functional materials, from graphene to semiconductor heterostructures, and from nanomembranes to Langmuir-Blodgett films play key roles in modern technologies. For such films optical interrogation is the main and often the only practical method of characterization. Here, we show that characterization of the optical response of thin films can be greatly improved with a type of coherent spectroscopy using two counterpropagating beams of light. The spectroscopy is selective to particular types of multipole resonances that form the absorption spectrum of the film, and therefore can reveal lines that are hidden in conventional absorption spectroscopy. We explicitly demonstrate selectivity of this spectroscopy in a series of proof-of-principle experiments with plasmonic metamaterial arrays designed to exhibit different multipole resonances. We further demonstrate the analytic potential of this spectroscopy by extracting the hidden resonance from the spectrum of a complex nanostructure.

  14. High energy resolution off-resonant X-ray spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Wojciech, Blachucki [Univ. of Fribourg (Switzerland). Dept. of Physics

    2015-10-16

    This work treats of the high energy resolution off-resonant X-ray spectroscopy (HEROS) method of determining the density of unoccupied electronic states in the vicinity of the absorption edge. HEROS is an alternative to the existing X-ray absorption spectroscopy (XAS) methods and opens the way for new studies not achievable before.

  15. Fast Resonance Raman Spectroscopy of Short-Lived Radicals

    DEFF Research Database (Denmark)

    Pagsberg, Palle Bjørn; Wilbrandt, Robert Walter; Hansen, Karina Benthin

    1976-01-01

    We report the first application of pulsed resonance Raman spectroscopy to the study of short-lived free radicals produced by pulse radiolysis. A single pulse from a flash-lamp pumped tunable dye laser is used to excite the resonance Raman spectrum of the p-terphenyl anion radical with an initial...

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2016-12-15

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

  17. Non-invasive in vivo evaluation of in situ forming PLGA implants by benchtop magnetic resonance imaging (BT-MRI) and EPR spectroscopy.

    Science.gov (United States)

    Kempe, Sabine; Metz, Hendrik; Pereira, Priscila G C; Mäder, Karsten

    2010-01-01

    In the present study, we used benchtop magnetic resonance imaging (BT-MRI) for non-invasive and continuous in vivo studies of in situ forming poly(lactide-co-glycolide) (PLGA) implants without the use of contrast agents. Polyethylene glycol (PEG) 400 was used as an alternative solvent to the clinically used NMP. In addition to BT-MRI, we applied electron paramagnetic resonance (EPR) spectroscopy to characterize implant formation and drug delivery processes in vitro and in vivo. We were able to follow key processes of implant formation by EPR and MRI. Because EPR spectra are sensitive to polarity and mobility, we were able to follow the kinetics of the solvent/non-solvent exchange and the PLGA precipitation. Due to the high water affinity of PEG 400, we observed a transient accumulation of water in the implant neighbourhood. Furthermore, we detected the encapsulation by BT-MRI of the implant as a response of the biological system to the polymer, followed by degradation over a period of two months. We could show that MRI in general has the potential to get new insights in the in vivo fate of in situ forming implants. The study also clearly shows that BT-MRI is a new viable and much less expensive alternative for superconducting MRI machines to monitor drug delivery processes in vivo in small mammals. Copyright 2009 Elsevier B.V. All rights reserved.

  18. Magnetic Resonance Spectroscopy of Breast Disease

    National Research Council Canada - National Science Library

    Ikeda, Debra

    2001-01-01

    We have developed a unique magnetic resonance imaging multi voxel pulse sequence producing spectroscopic images of key metabolites found in breast cancer, and validated our work with in vitro spectra and pathology...

  19. Experimental studies on evaluation of the effects of radiotherapy and chemotherapy in urogenital tumors using [sup 31]P-magnetic resonance spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Kanimoto, Yusuke; Suzuki, Yuji; Okada, Kenichiro (Fukui Medical School, Matsuoka (Japan))

    1994-04-01

    The effects of local irradiation and intraperitoneal injection of cisplatinum (CDDP) and VP-16 were examined in the sequential [sup 31]P magnetic resonance spectroscopy (MRS) in testicular cancer (TC-1) and bladder tumor (BT-8) of human origin, serially transplanted in nude mice. In the early phase of tumor growth, high-energy phosphate metabolites such as phosphocreatinine (PCr), adenosine triphosphate (ATP) and phosphomonoester (PME) were detected in both grafted tumors. However, the relative value of inorganic phosphate (Pi) to PCr increased with the growth of the tumor. Irradiation had the most pronounced effect to inhibit growth, followed by CDDP in both strains. However, growth inhibition was not observed in the VP-16 group. The effect of irradiation on the tumor histology was severely expressed in the nucleus and cytoplasm on the 4th to 7th day. The high PCr/Pi ratio during 2 to 14 days after irradiation suggested reoxygenation in the tumors with a high hypoxic cell fraction. In the CDDP and VP-16 groups, without histological change, the changes of PCr and Pi were milder than that in the irradiation group. Thus the spectroscopic analysis is presumably expected to give us an earlier and more accurate information on the tumor than the conventional parameters. (author).

  20. Evaluation of the distribution of Paclitaxel by immunohistochemistry and nuclear magnetic resonance spectroscopy after the application of a drug-eluting balloon in the porcine ureter.

    Science.gov (United States)

    Liourdi, Despoina; Kallidonis, Panagiotis; Kyriazis, Iason; Tsamandas, Athanasios; Karnabatidis, Dimitrios; Kitrou, Panagiotis; Spyroulias, Georgios A; Kostopoulou, Ourania N; Marousis, Kostas; Kalpaxis, Dimitrios L; Goumenos, Dimitrios S; Liatsikos, Evangelos

    2015-05-01

    The urothelium represents "the tightest and most impermeable barrier in the body." We investigated the distribution of paclitaxel (PTX) in the ureteral wall after the inflation of a paclitaxel-eluting balloon (PEB) in an attempt to elucidate the possibility of clinical application of PEBs in the ureter. Nine domestic pigs were used. Nine PEBs and nine conventional percutaneous angioplasty balloons (CB) were inflated in the right and left ureter of each animal, respectively. The ureter treated by CB was the control for the contralateral ureter. Specimens were removed: Immediately after inflation (group A), after 12 hours (group B), and after 24 hours (group C). Two samples were obtained from each ureter of groups A, B and C. One sample was investigated by nuclear magnetic resonance spectroscopy (NMR), the other by histology and immunohistochemistry (IHC) using a specific for PTX polyclonal antibody. Reduced inflammation was observed in the group B and C samples in comparison with their controls. PTX was distributed mostly in the urothelium and submucosal layer in group A (IHC). The agent was present in the urothelial, submucosal, and muscle layer in groups B and C. The concentration of PTX (NMR) has been reduced in group C compared with the tissue extracts of group B. The distribution of PTX includes the urothelial, submucosal, and smooth muscle layers. Inflammation was reduced in the case of drug-eluting balloons.

  1. Resonance Raman Spectroscopy of Free Radicals Produced by Ionizing Radiation

    DEFF Research Database (Denmark)

    Wilbrandt, Robert Walter

    1984-01-01

    Applications of time-resolved resonance Raman spectroscopy to the study of short-lived free radicals produced by ionizing radiation are briefly reviewed. Potential advantages and limitations of this technique are discussed in the light of given examples. The reduction of p-nitrobenzylchloride and......Applications of time-resolved resonance Raman spectroscopy to the study of short-lived free radicals produced by ionizing radiation are briefly reviewed. Potential advantages and limitations of this technique are discussed in the light of given examples. The reduction of p......-nitrobenzylchloride and subsequent formation of the p-nitrobenzyl radical and the reaction of p-nitrotoluene with O– are studied by resonance Raman and optical absorption spectroscopy....

  2. Changes of the cerebral metabolite patterns in patients undergoing hemodialysis due to chronic renal failure: evaluation with proton magnetic resonance spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Baik, Hye Won; Yu, Hyeon; Yu, Soo Jeong; Kim, Gi Hyeon [Chung-Ang University Medical Center, College of Medicine, Seoul (Korea, Republic of)

    2007-08-15

    We wanted to evaluate the cerebral metabolites in patients with chronic renal failure (CRF) and who were undergoing hemodialysis by performing proton MR spectroscopy and were wanted to evaluate the correlation between the changes in the cerebral metabolite ratios and the duration after starting the initial hemodialysis. Proton MR spectroscopy was performed in 15 patients with CRF and who were undergoing hemodialysis and in ten healthy volunteers. The changes in N-acetylaspartate (NAA), choline-containing compounds (Cho), myo-inositol (Myo), glutamine/glutamate complex (Glx), and creatine (Cr) were analyzed. MR spectroscopy was performed before and after hemodialysis. For the patients with CRF before hemodialysis, the Cho/Cr ratio in the gray matter ({rho} < 0.001) and the Myo/Cr ratio in both the gray and white matter ({rho} < 0.01) were significantly elevated compared with those in the control subjects. For the patients with CRF after hemodialysis, their Cho/Cr ratios were significantly reduced in both the gray and white matter compared with that before hemodialysis ({rho} < 0.05). There was a significant positive correlation between the Cho/Cr ratio and serum Cr in the gray matter of CRF patients after hemodialysis (r = 0.54, {rho} < 0.05). The cerebral metabolite ratios were not significantly correlated with the duration after starting the initial hemodialysis. The cerebral metabolite patterns are significantly different between the patients with CRF and who are undergoing hemodialysis and the normal controls. The cerebral metabolite ratios are not significantly correlated with the duration after starting the initial hemodialysis.

  3. Waveguide volume probe for magnetic resonance imaging and spectroscopy

    DEFF Research Database (Denmark)

    2015-01-01

    The present disclosure relates to a probe for use within the field of nuclear magnetic resonance, such as magnetic resonance imaging (MRI), and magnetic resonance spectroscopy (MRS)). One embodiment relates to an RF probe for magnetic resonance imaging and/or spectroscopy comprising a conductive...... non-magnetic hollow waveguide having an internal volume and at least one open end, one or more capacitors and at least a first conductive non-magnetic wire, wherein said first conductive wire connects at least one of said one or more capacitors to opposite walls of one open end of the waveguide...... and wherein said first conductive wire and said one or more capacitors are located outside of said internal volume, wherein the internal volume of the hollow waveguide defines an imaging volume or sample volume....

  4. 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.

  5. Detection of Nitric Oxide by Electron Paramagnetic Resonance Spectroscopy

    OpenAIRE

    Hogg, Neil

    2010-01-01

    Electron paramagnetic resonance (EPR) spectroscopy has been used in a number of ways to study nitric oxide chemistry and biology. As an intrinsically stable and relatively unreactive diatomic free radical, the challenges for detecting this species by EPR are somewhat different than those for transient radical species. This review gives a basic introduction to EPR spectroscopy and discusses its uses to assess and quantify nitric oxide formation in biological systems.

  6. Assessment of trabecular bone tissue elasticity with resonant ultrasound spectroscopy

    OpenAIRE

    Daoui, H.; Cai, Xiran; BOUBENIDER, F.; Laugier, P.; Grimal, Q.

    2017-01-01

    International audience; The material properties of the trabeculae (tissue-level properties), together with the trabecular architecture and the bone volume fraction determine the apparent millimetre-scale bone mechanical properties. We present a novel method to measure trabecular tissue elastic modulus E t using resonant ultrasound spec-troscopy (RUS). The first mechanical resonance frequency f e of a freestanding cuboid specimen is measured and used to back-calculate E t. The steps of the bac...

  7. Acoustic properties of novel materials using resonant ultrasound spectroscopy

    Science.gov (United States)

    Pestka, Kenneth A., II

    Resonant Ultrasound Spectroscopy (RUS) is a relatively new acoustic method capable of determining an object's elastic tensor through observation of the object's normal modes of free vibration. This work describes the acoustic properties and characterization of five different novel materials using the RUS technique. The elastic constants of thin film magnesium diboride (MgB2), a Bardeen Cooper Schrieffer (BCS) type superconductor, were measured for the first time and are significantly different from theoretical bulk calculations indicating the presence of strain induced effects. The resonant spectra of arbitrarily shaped bulk magnesium diboride samples were measured and the subsequent investigation, which included Finite Element Analysis (FEA), demonstrated that the samples were not uniform single crystals. In addition to the superconductor MgB2, several other unusual materials were investigated; the elastic constants of thin film columnar silicon carbide were measured to assess changes in material elasticity due to thin film growth mechanisms, the elastic constants of the biological material human dentin were measured to assess variation in elastic constants due to age of the sample donor, the complete elastic tensor of bulk gadolinium scandate (GdScO 3) was measured and sound speeds determined to evaluate applications in acoustic cavity design, and the bulk acoustic sound speed of the colossal magnetoresistant material La0.7Ca0.3MnO3 was determined via RUS for comparison with recently available sound speed measurements obtained using optical pulse methods.

  8. Phosphorus magnetic resonance spectroscopy in malformations of cortical development

    Directory of Open Access Journals (Sweden)

    Celi Santos Andrade

    2013-07-01

    Full Text Available Introduction Malformations of cortical development (MCD result from disruptions in the dynamic process of cerebral corticogenesis and are important causes of epilepsy, motor deficits and cognitive impairment. Objectives The aim of this study was to evaluate phospholipids metabolism in vivo in a series of patients with epilepsy and MCD. Methods Thirty-seven patients with MCD and 31 control subjects were studied using three-dimensional phosphorus magnetic resonance spectroscopy (31P-MRS at a 3.0 T scanner. Quantification methods were applied to the following resonances: phosphoethanolamine (PE, phosphocholine (PC, glycerophosphoethanolamine (GPE, glycerophosphocholine (GPC, inorganic phosphate (Pi, phosphocreatine (PCr, and a-, b-, and g-adenosine triphosphate (ATP. The magnesium (Mg2+ levels and pH were calculated based on PCr, Pi and b-ATP chemical shifts. Results Compared to controls, the MCD lesions exhibited lower pH values and higher Mg2+ levels (p<0.05. The lesions also presented significant reduction of GPC and PDE, and an increased PME/PDE ratio. The otherwise normal appearing parenchyma also demonstrated lower pH values in the frontoparietal cortex and bilateral centrum semiovale. Conclusions Our data support the idea that metabolic impairments occur in the lesions of MCD, with propagation to remote normal appearing parenchyma. The results also suggest that there are membrane turnover disturbances in MCD lesions.

  9. In vivo magnetic resonance spectroscopy; In vivo magnetisk resonansspektroskopi

    Energy Technology Data Exchange (ETDEWEB)

    Bakken, Inger Johanne; Skjetne, Tore; Gribbestad, Ingrid S.; Kvistad, Kjell Arne

    2002-07-01

    Magnetic resonance tomography (MR) has become a highly useful tool for diagnostic imaging. The technology is in a process of rapid development with new and better methods emerging for the imaging of anatomic and pathologic aspects. With some additional equipment, the MR instrument may also be used for in vivo magnetic resonance spectroscopy (MRS). In vivo MRS provides biochemical information about metabolites in a given tissue volume. This type of biochemical information can be extracted from volumes the size of a sugar lump within a recording period of about five minutes. New technologies also allow extracting such information from several volumes during one recording in which the information is processed as metabolic pictures. The method has found clinical applications in several fields, including the evaluation of brain tumours and epilepsy. The use of in vivo MRS will probably increase in the years ahead, especially, perhaps, for the follow-up of various therapeutic regimens. All suppliers of MR equipment now provide in vivo MRS sets and routines for recording and data analysis have become very user-friendly. (author)

  10. Periodontitis diagnostics using resonance Raman spectroscopy on saliva

    Science.gov (United States)

    Gonchukov, S.; Sukhinina, A.; Bakhmutov, D.; Biryukova, T.; Tsvetkov, M.; Bagratashvily, V.

    2013-07-01

    In view of its wealth of molecular information, Raman spectroscopy has been the subject of active biomedical research. The aim of this work is Raman spectroscopy (RS) application for the determination of molecular biomarkers in saliva with the objective of early periodontitis detection. As was shown in our previous study, carotenoids contained in saliva can be molecular fingerprint information for the periodontitis level. It is shown here that the carotenoid RS lines at wavenumbers of 1156 and 1524 cm-1 can be easily detected and serve as reliable biomarkers of periodontitis using resonance Raman spectroscopy of dry saliva.

  11. The INTERPRET Decision-Support System version 3.0 for evaluation of Magnetic Resonance Spectroscopy data from human brain tumours and other abnormal brain masses

    Directory of Open Access Journals (Sweden)

    Mercadal Guillem

    2010-11-01

    Full Text Available Abstract Background Proton Magnetic Resonance (MR Spectroscopy (MRS is a widely available technique for those clinical centres equipped with MR scanners. Unlike the rest of MR-based techniques, MRS yields not images but spectra of metabolites in the tissues. In pathological situations, the MRS profile changes and this has been particularly described for brain tumours. However, radiologists are frequently not familiar to the interpretation of MRS data and for this reason, the usefulness of decision-support systems (DSS in MRS data analysis has been explored. Results This work presents the INTERPRET DSS version 3.0, analysing the improvements made from its first release in 2002. Version 3.0 is aimed to be a program that 1st, can be easily used with any new case from any MR scanner manufacturer and 2nd, improves the initial analysis capabilities of the first version. The main improvements are an embedded database, user accounts, more diagnostic discrimination capabilities and the possibility to analyse data acquired under additional data acquisition conditions. Other improvements include a customisable graphical user interface (GUI. Most diagnostic problems included have been addressed through a pattern-recognition based approach, in which classifiers based on linear discriminant analysis (LDA were trained and tested. Conclusions The INTERPRET DSS 3.0 allows radiologists, medical physicists, biochemists or, generally speaking, any person with a minimum knowledge of what an MR spectrum is, to enter their own SV raw data, acquired at 1.5 T, and to analyse them. The system is expected to help in the categorisation of MR Spectra from abnormal brain masses.

  12. In vivo magnetic resonance spectroscopy: basic methodology and clinical applications.

    NARCIS (Netherlands)

    Graaf, M. van der

    2010-01-01

    The clinical use of in vivo magnetic resonance spectroscopy (MRS) has been limited for a long time, mainly due to its low sensitivity. However, with the advent of clinical MR systems with higher magnetic field strengths such as 3 Tesla, the development of better coils, and the design of optimized

  13. Resonant Dipole Nanoantenna Arrays for Enhanced Terahertz Spectroscopy

    KAUST Repository

    Toma, A.

    2015-08-04

    Our recent studies on dipole nanoantenna arrays resonating in the terahertz frequency range (0.1 – 10 THz) will be presented. The main near- and far-field properties of these nanostructures will be shown and their application in enhanced terahertz spectroscopy of tiny quantities of nanomaterials will be discussed.

  14. Role of proton magnetic resonance spectroscopy in diagnosis of ...

    African Journals Online (AJOL)

    Mohammed Mahmoud Donia

    2012-01-23

    Jan 23, 2012 ... Aim of the work: To study the role of proton magnetic resonance spectroscopy in diagnosis of pil- ocytic astrocytoma in children. Subjects and methods: This study included seven pediatric patients with histopathologically proven pilocytic astrocytoma. All patients were subjected to full history taking and ...

  15. Surface Plasmon Resonance Spectroscopy: A Versatile Technique in a

    Science.gov (United States)

    Bakhtiar, Ray

    2013-01-01

    Surface plasmon resonance (SPR) spectroscopy is a powerful, label-free technique to monitor noncovalent molecular interactions in real time and in a noninvasive fashion. As a label-free assay, SPR does not require tags, dyes, or specialized reagents (e.g., enzymes-substrate complexes) to elicit a visible or a fluorescence signal. During the last…

  16. Introduction to Spin Label Electron Paramagnetic Resonance Spectroscopy of Proteins

    Science.gov (United States)

    Melanson, Michelle; Sood, Abha; Torok, Fanni; Torok, Marianna

    2013-01-01

    An undergraduate laboratory exercise is described to demonstrate the biochemical applications of electron paramagnetic resonance (EPR) spectroscopy. The beta93 cysteine residue of hemoglobin is labeled by the covalent binding of 3-maleimido-proxyl (5-MSL) and 2,2,5,5-tetramethyl-1-oxyl-3-methyl methanethiosulfonate (MTSL), respectively. The excess…

  17. Using Multi Resonance Effects Towards Single Conformer Microwave Spectroscopy

    Science.gov (United States)

    Abeysekera, Chamara; Hernandez-Castillo, Alicia O.; Hays, Brian M.; Zwier, Timothy S.

    2016-06-01

    The relationship between the molecular structure and rotational frequencies makes rotational spectroscopy highly structural specific and an ideal tool for complex mixture analysis. The modern developments in broadband microwave techniques have immensely reduced the data acquisition time, while creating a need for high speed data analysis procedures. A new microwave-microwave double resonance method will be introduced, to perform single conformer/isomer microwave spectroscopy in complex chemical mixtures. The method combines the selective excitation schemes possible in chirped pulse microwave spectroscopy with multi-resonance effects observed upon sweeping in the rapid adiabatic passage regime, enabling perturbations to be induced in the intensities of most of the transitions ascribable to a single molecular constituent (e.g. a conformational isomer) in a mixture. Details of the method, experimental implementation and future challenges will be discussed.

  18. Cardiac magnetic resonance spectroscopy: potential clinical applications

    Energy Technology Data Exchange (ETDEWEB)

    Neubauer, S. [Dept. of Cardiovascular Medicine, Oxford Univ. (United Kingdom)

    2000-06-01

    MR spectroscopy is the only method for non-invasive detection of various aspects of cardiac metabolism in humans. While the {sup 1}H nucleus of water and fat molecules is the signal source for MR imaging, the MR spectroscopic technique allows for the study of a number of other nuclei, such as {sup 13}C, {sup 19}F, {sup 23}Na, {sup 31}P, {sup 39}K and {sup 87}Rb. Clinical applications presently are confined to the {sup 31}P nucleus. {sup 31}P-MR spectroscopy allows the non-invasive study of cardiac high-energy phosphate metabolites ATP and phosphocreatine. The phosphocreatine/ATP ratio is considered an index of the energetic state of the heart. Possible clinical indications include heart failure, valve disease and coronary artery disease. In heart failure, the phosphocreatine/ATP ratio is reduced and correlates with clinical severity, ejection fraction and prognosis. In mitral and aortic valve disease, a reduced phosphocreatine/ATP ratio may indicate the optimum timing for valve replacement. In coronary artery disease, a regional decrease of phosphocreatine during stress (''biochemical ergometry'') may indicate local ischemia. Furthermore, absolute quantification of high-energy phosphates may allow diagnosis of myocardial viability. Major technical developments, leading to improved spatial and temporal resolution will be necessary to establish MR spectroscopy as a routine clinical tool. (orig.) [German] Die MR-Spektroskopie ist die einzige Methode, die es erlaubt, am Patienten verschiedene Aspekte des Myokardstoffwechsels nichtinvasiv zu untersuchen. Waehrend der {sup 1}H-Kern der Wasser- und Fettmolekuele die Signalquelle fuer die MR-Bildgebung darstellt, kann man mit der Spektroskopie eine Vielzahl anderer Kerne wie {sup 13}C, {sup 19}F, {sup 23}Na, {sup 31}P, {sup 39}K und {sup 87}Rb untersuchen. Klinische Anwendungen sind bisher auf die {sup 31}P-MR Spektroskopie beschraenkt. Mit dieser Methode lassen sich die energiereichen Phosphate ATP und

  19. Glutamatergic Effects of Divalproex in Adolescents with Mania: A Proton Magnetic Resonance Spectroscopy Study

    Science.gov (United States)

    Strawn, Jeffrey R.; Patel, Nick C.; Chu, Wen-Jang; Lee, Jing-Huei; Adler, Caleb M.; Kim, Mi Jung; Bryan, Holly S.; Alfieri, David C.; Welge, Jeffrey A.; Blom, Thomas J.; Nandagopal, Jayasree J.; Strakowski, Stephen M.; DelBello, Melissa P.

    2012-01-01

    Objectives: This study used proton magnetic resonance spectroscopy ([superscript 1]H MRS) to evaluate the in vivo effects of extended-release divalproex sodium on the glutamatergic system in adolescents with bipolar disorder, and to identify baseline neurochemical predictors of clinical remission. Method: Adolescents with bipolar disorder who were…

  20. Brain magnetic resonance imaging and magnetic resonance spectroscopy findings of children with kernicterus.

    Science.gov (United States)

    Sarı, Sahabettin; Yavuz, Alpaslan; Batur, Aabdussamet; Bora, Aydın; Caksen, Huseyin

    2015-01-01

    The term kernicterus, or bilirubin encephalopathy, is used to describe pathological bilirubin staining of the basal ganglia, brain stem, and cerebellum, and is associated with hyperbilirubinemia. Kernicterus generally occurs in untreated hyperbilirubinemia or cases where treatment is delayed. Magnetic resonance imaging (MRI)-based studies have shown characteristic findings in kernicterus. The objective of our study was to describe the role of (1)H magnetic resonance spectroscopy (MRS) in demonstrating these metabolic changes and to review conventional MRI findings of kernicterus. Forty-eight pediatric cases with kernicterus were included in this study. MRI and MRS examinations were performed on variable dates (10-29 days after birth). NAA, Cr, Cho, NAA/Cr, NAA/Cho, and Cho/Cr values were evaluated visually and by computer analysis. There was no statistically significant difference between the NAA and Cho levels in the acute kernicterus patients and the control group (healthy patients), whereas both were significantly elevated in the chronic kernicterus patients. Both the mean NAA/Cr and Cho/Cr ratio values were significantly higher in the acute and chronic cases compared to the control group. The NAA/Cho ratio value was statistically lower in the acute cases than in the control group while it was similar in the chronic cases. Conventional MR imaging and (1)H-MRS are important complementary tools in the diagnostics of neonatal bilirubin encephalopathy. This study provided important information for applying these MR modalities in the evaluation of neonates with bilirubin encephalopathy.

  1. Resonance ionization spectroscopy using ultraviolet laser

    CERN Document Server

    Han, J M; Ko, D K; Park, H M; Rhee, Y J

    2002-01-01

    In this study, Ti:sapphire laser which is pumped by the enhanced Nd:YAG laser using laser diode, was designed and manufactured. The AO Q-switched CW Nd:YAG laser was converted into a high repetition plus-type laser using the AO Q-switch, and two heads were installed inside the cavity in order to improve the laser beam quality. The Nd:YAG laser enhancement was completed by optimization using a simulation for the cavity length, structure and thermal lens effect that greatly effected the laser beam output and quality. As the result of the enhancement, a 30W laser at 532nm and at 5k-Hz was successfully made. Also, the Ti:sapphire laser that will be used for atomic spectroscopy which is pumped by the Nd:YAG laser, was completely designed. As a basic experiment for laser oscillation. We measured the tunability of the laser, and it turned out that the wave tunability range was 730 850 nm. A self-seeding type tunable laser using grating for narrow line width, is planned to be designed due to the fact that the Ti:sapp...

  2. The diagnostic accuracy and cost-effectiveness of magnetic resonance spectroscopy and enhanced magnetic resonance imaging techniques in aiding the localisation of prostate abnormalities for biopsy: a systematic review and economic evaluation.

    Science.gov (United States)

    Mowatt, G; Scotland, G; Boachie, C; Cruickshank, M; Ford, J A; Fraser, C; Kurban, L; Lam, T B; Padhani, A R; Royle, J; Scheenen, T W; Tassie, E

    2013-05-01

    In the UK, prostate cancer (PC) is the most common cancer in men. A diagnosis can be confirmed only following a prostate biopsy. Many men find themselves with an elevated prostate-specific antigen (PSA) level and a negative biopsy. The best way to manage these men remains uncertain. To assess the diagnostic accuracy of magnetic resonance spectroscopy (MRS) and enhanced magnetic resonance imaging (MRI) techniques [dynamic contrast-enhanced MRI (DCE-MRI), diffusion-weighted MRI (DW-MRI)] and the clinical effectiveness and cost-effectiveness of strategies involving their use in aiding the localisation of prostate abnormalities for biopsy in patients with prior negative biopsy who remain clinically suspicious for harbouring malignancy. Databases searched--MEDLINE (1946 to March 2012), MEDLINE In-Process & Other Non-Indexed Citations (March 2012), EMBASE (1980 to March 2012), Bioscience Information Service (BIOSIS; 1995 to March 2012), Science Citation Index (SCI; 1995 to March 2012), The Cochrane Library (Issue 3 2012), Database of Abstracts of Reviews of Effects (DARE; March 2012), Medion (March 2012) and Health Technology Assessment database (March 2012). Types of studies: direct studies/randomised controlled trials reporting diagnostic outcomes. MRS, DCE-MRI and DW-MRI. Comparators: T2-weighted magnetic resonance imaging (T2-MRI), transrectal ultrasound-guided biopsy (TRUS/Bx). Reference standard: histopathological assessment of biopsied tissue. A Markov model was developed to assess the cost-effectiveness of alternative MRS/MRI sequences to direct TRUS-guided biopsies compared with systematic extended-cores TRUS-guided biopsies. A health service provider perspective was adopted and the recommended 3.5% discount rate was applied to costs and outcomes. A total of 51 studies were included. In pooled estimates, sensitivity [95% confidence interval (CI)] was highest for MRS (92%; 95% CI 86% to 95%). Specificity was highest for TRUS (imaging test) (81%; 95% CI 77% to 85

  3. High Resolution-Resonance Ionization Spectroscopy on uranium

    Energy Technology Data Exchange (ETDEWEB)

    Hakimi, Amin, E-mail: hakimi@uni-mainz.de; Fischbach, Thomas [Johannes Gutenberg-Universitaet Mainz, Institut fuer Physik (Germany); Raeder, Sebastian [TRIUMF (Canada); Trautmann, Norbert [Johannes Gutenberg-Universitaet Mainz, Institut fuer Kernchemie (Germany); Wendt, Klaus [Johannes Gutenberg-Universitaet Mainz, Institut fuer Physik (Germany)

    2013-04-15

    High Resolution-Resonance Ionization Spectroscopy (HR-RIS) allows for sensitive probing of atomic structures and energy level schemes even for highly complex systems. This work explores the applicability of commercial diode lasers for isotope selective spectroscopy of uranium. Using narrow bandwidth continuous-wave (cw) diode lasers, multi step excitation processes were investigated involving levels which could be populated with the radiation of 405 nm BluRay{sup Copyright-Sign} laser diodes as a first step for ultra trace analysis of uranium.

  4. Magnetic Resonance Spectroscopy of siRNA-Based Cancer Therapy.

    Science.gov (United States)

    Penet, Marie-France; Chen, Zhihang; Mori, Noriko; Krishnamachary, Balaji; Bhujwalla, Zaver M

    2016-01-01

    Small interfering RNA (siRNA) is routinely used as a biological tool to silence specific genes, and is under active investigation in cancer treatment strategies. Noninvasive magnetic resonance spectroscopy (MRS) provides the ability to assess the functional effects of siRNA-mediated gene silencing in cultured cancer cells, and following nanoparticle-based delivery in tumors in vivo. Here we describe the use of siRNA to downregulate choline kinase, a critical enzyme in choline phospholipid metabolism of cancer cells and tumors, and the use of (1)H MRS of cells and (1)H magnetic resonance spectroscopic imaging (MRSI) of tumors to assess the efficacy of the downregulation.

  5. Resonant ultrasound spectroscopy: Elastic properties of some intermetallic compounds

    Energy Technology Data Exchange (ETDEWEB)

    Chu, F.; Thoma, D.J.; He, Y.; Maloy, S.A.; Mitchell, T.E. [Los Alamos National Lab., NM (United States). Materials Science Technology Div.

    1996-09-01

    A novel nondestructive evaluation method, resonant ultrasound spectroscopy (RUS), is reviewed with an emphasis upon defining the elastic properties of intermetallic phases. The applications and advantages of RUS as compared to other conventional elastic constant measurement methods are explained. RUS has been employed to measure the elastic properties of single crystal and/or polycrystalline intermetallics, such as Laves phases (C15 HfV{sub 2} and NbCr{sub 2}), Nb-modified titanium aluminides, and transition metal disilicides (C11{sub b} MoSi{sub 2}, C40 NbSi{sub 2} and TaSi{sub 2}). For Laves phases, the elastic properties of HfV{sub 2}-based C15 phases show various anomalies and those of C15 NbCr{sub 2} do not. For Nb-modified titanium aluminides, the elastic properties of O-phase alloys are investigated as a function of alloying content. For transition metal disilicides, single crystal elastic constants of MoSi{sub 2}, NbSi{sub 2}, and TaSi{sub 2} are obtained and compared. Based on the experimentally determined elastic properties, the characteristics of interatomic bonding in these materials are examined and the possible impact of the elastic properties on mechanical behavior is discussed.

  6. Gravity Resonance Spectroscopy and Einstein-Cartan Gravity

    OpenAIRE

    Abele, Hartmut; Ivanov, Andrei; Jenke, Tobias; Pitschmann, Mario; Geltenbort, Peter

    2015-01-01

    The qBounce experiment offers a new way of looking at gravitation based on quantum interference. An ultracold neutron is reflected in well-defined quantum states in the gravity potential of the Earth by a mirror, which allows to apply the concept of gravity resonance spectroscopy (GRS). This experiment with neutrons gives access to all gravity parameters as the dependences on distance, mass, curvature, energy-momentum as well as on torsion. Here, we concentrate on torsion.

  7. Two-Color Laser Resonance Ionization Spectroscopy of Zirconium Atoms

    Science.gov (United States)

    Hasegawa, Shuichi; Nagamoto, Daisuke

    2017-10-01

    We have performed two-color laser resonance ionization spectroscopy of zirconium atoms to measure the energies of excited states below the third ionization limit. The number of intermediate states that we observed is 19, and energies deduced from the experiments agree with previous data. Complex ionization spectra of the excited states were observed through the intermediate states. The values of the first, second, and third ionization limits were derived from the Rydberg series of the spectra with quantum defect theory.

  8. Brain Biochemistry and Personality: A Magnetic Resonance Spectroscopy Study

    OpenAIRE

    Ryman, Sephira G.; Gasparovic, Chuck; Bedrick, Edward J.; Flores, Ranee A.; Marshall, Alison N.; Jung, Rex E.

    2011-01-01

    To investigate the biochemical correlates of normal personality we utilized proton magnetic resonance spectroscopy ((1)H-MRS). Our sample consisted of 60 subjects ranging in age from 18 to 32 (27 females). Personality was assessed with the NEO Five-Factor Inventory (NEO-FFI). We measured brain biochemistry within the precuneus, the cingulate cortex, and underlying white matter. We hypothesized that brain biochemistry within these regions would predict individual differences across major domai...

  9. 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.

  10. Magnetic resonance spectroscopy and imaging for the study of fossils.

    Science.gov (United States)

    Giovannetti, Giulio; Guerrini, Andrea; Salvadori, Piero A

    2016-07-01

    Computed tomography (CT) has long been used for investigating palaeontological specimens, as it is a nondestructive technique which avoids the need to dissolve or ionize the fossil sample. However, magnetic resonance spectroscopy (MRS) and magnetic resonance imaging (MRI) have recently gained ground as analytical tools for examination of palaeontological samples, by nondestructively providing information about the structure and composition of fossils. While MRI techniques are able to reveal the three-dimensional geometry of the trace fossil, MRS can provide information on the chemical composition of the samples. The multidimensional nature of MR (magnetic resonance) signals has potential to provide rich three-dimensional data on the palaeontological specimens and also to help in elucidating paleopathological and paleoecological questions. In this work the verified applications and the emerging uses of MRI and MRS in paleontology are reviewed, with particular attention to fossil spores, fossil plants, ambers, fossil invertebrates, and fossil vertebrate studies. Copyright © 2016 Elsevier Inc. All rights reserved.

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

    Science.gov (United States)

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

    2012-01-01

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

  12. High energy resolution off-resonant spectroscopy: A review

    Science.gov (United States)

    Błachucki, Wojciech; Hoszowska, Joanna; Dousse, Jean-Claude; Kayser, Yves; Stachura, Regina; Tyrała, Krzysztof; Wojtaszek, Klaudia; Sá, Jacinto; Szlachetko, Jakub

    2017-10-01

    We review the high energy resolution off-resonant spectroscopy (HEROS) technique. HEROS probes the unoccupied electronic states of matter in a single-shot manner thanks to the combination of off-resonant excitation around atomic core states using wavelength dispersive X-ray detection setups. In this review we provide a general introduction to the field of X-ray spectroscopy together with the specification of the available X-ray techniques and X-ray methodologies. Next, the theoretical description of the HEROS approach is introduced with a special focus on the derivation of the X-ray emission and X-ray absorption correspondence relation at off-resonant excitation conditions. Finally, a number of experimental HEROS reports are reviewed in the field of chemistry and material science. We emphasize the applicability of HEROS to pulsed X-ray sources, like X-ray free electron lasers, and support the review with experimental examples. The review is complemented with perspectives on and possible further applications of the HEROS technique to the field of X-ray science.

  13. Acoustic Resonance Spectroscopy (ARS) Munition Classification System enhancements. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Vela, O.A.; Huggard, J.C.

    1997-09-18

    Acoustic Resonance Spectroscopy (ARS) is a non-destructive evaluation technology developed at the Los Alamos National Laboratory (LANL). This technology has resulted in three generations of instrumentation, funded by the Defense Special Weapons Agency (DSWA), specifically designed for field identification of chemical weapon (CW) munitions. Each generation of ARS instrumentation was developed with a specific user in mind. The ARS1OO was built for use by the U.N. Inspection Teams going into Iraq immediately after the Persian Gulf War. The ARS200 was built for use in the US-Russia Bilateral Chemical Weapons Treaty (the primary users for this system are the US Onsite Inspection Agency (OSIA) and their Russian counterparts). The ARS300 was built with the requirements of the Organization for the Prohibition of Chemical Weapons (OPCW) in mind. Each successive system is an improved version of the previous system based on learning the weaknesses of each and, coincidentally, on the fact that more time was available to do a requirements analysis and the necessary engineering development. The ARS300 is at a level of development that warrants transferring the technology to a commercial vendor. Since LANL will supply the computer software to the selected vendor, it is possible for LANL to continue to improve the decision algorithms, add features where necessary, and adjust the user interface before the final transfer occurs. This paper describes the current system, ARS system enhancements, and software enhancements. Appendices contain the Operations Manual (software Version 3.01), and two earlier reports on enhancements.

  14. A microwave resonator for limiting depth sensitivity for electron paramagnetic resonance spectroscopy of surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Sidabras, Jason W.; Varanasi, Shiv K.; Hyde, James S. [Department of Biophysics, Medical College of Wisconsin, Milwaukee, Wisconsin 53211 (United States); Mett, Richard R. [Department of Biophysics, Medical College of Wisconsin, Milwaukee, Wisconsin 53211 (United States); Department of Physics and Chemistry, Milwaukee School of Engineering, Milwaukee, Wisconsin 53202 (United States); Swarts, Steven G. [Department of Radiation Oncology, University of Florida, Gainesville, Florida, 32610 (United States); Swartz, Harold M. [Department of Radiology, Geisel Medical School at Dartmouth, Hanover, New Hampshire 03755 (United States)

    2014-10-15

    A microwave Surface Resonator Array (SRA) structure is described for use in Electron Paramagnetic Resonance (EPR) spectroscopy. The SRA has a series of anti-parallel transmission line modes that provides a region of sensitivity equal to the cross-sectional area times its depth sensitivity, which is approximately half the distance between the transmission line centers. It is shown that the quarter-wave twin-lead transmission line can be a useful element for design of microwave resonators at frequencies as high as 10 GHz. The SRA geometry is presented as a novel resonator for use in surface spectroscopy where the region of interest is either surrounded by lossy material, or the spectroscopist wishes to minimize signal from surrounding materials. One such application is in vivo spectroscopy of human finger-nails at X-band (9.5 GHz) to measure ionizing radiation dosages. In order to reduce losses associated with tissues beneath the nail that yield no EPR signal, the SRA structure is designed to limit depth sensitivity to the thickness of the fingernail. Another application, due to the resonator geometry and limited depth penetration, is surface spectroscopy in coating or material science. To test this application, a spectrum of 1.44 μM of Mg{sup 2+} doped polystyrene 1.1 mm thick on an aluminum surface is obtained. Modeling, design, and simulations were performed using Wolfram Mathematica (Champaign, IL; v. 9.0) and Ansys High Frequency Structure Simulator (HFSS; Canonsburg, PA; v. 15.0). A micro-strip coupling circuit is designed to suppress unwanted modes and provide a balanced impedance transformation to a 50 Ω coaxial input. Agreement between simulated and experimental results is shown.

  15. A microwave resonator for limiting depth sensitivity for electron paramagnetic resonance spectroscopy of surfaces.

    Science.gov (United States)

    Sidabras, Jason W; Varanasi, Shiv K; Mett, Richard R; Swarts, Steven G; Swartz, Harold M; Hyde, James S

    2014-10-01

    A microwave Surface Resonator Array (SRA) structure is described for use in Electron Paramagnetic Resonance (EPR) spectroscopy. The SRA has a series of anti-parallel transmission line modes that provides a region of sensitivity equal to the cross-sectional area times its depth sensitivity, which is approximately half the distance between the transmission line centers. It is shown that the quarter-wave twin-lead transmission line can be a useful element for design of microwave resonators at frequencies as high as 10 GHz. The SRA geometry is presented as a novel resonator for use in surface spectroscopy where the region of interest is either surrounded by lossy material, or the spectroscopist wishes to minimize signal from surrounding materials. One such application is in vivo spectroscopy of human finger-nails at X-band (9.5 GHz) to measure ionizing radiation dosages. In order to reduce losses associated with tissues beneath the nail that yield no EPR signal, the SRA structure is designed to limit depth sensitivity to the thickness of the fingernail. Another application, due to the resonator geometry and limited depth penetration, is surface spectroscopy in coating or material science. To test this application, a spectrum of 1.44 μM of Mg(2+) doped polystyrene 1.1 mm thick on an aluminum surface is obtained. Modeling, design, and simulations were performed using Wolfram Mathematica (Champaign, IL; v. 9.0) and Ansys High Frequency Structure Simulator (HFSS; Canonsburg, PA; v. 15.0). A micro-strip coupling circuit is designed to suppress unwanted modes and provide a balanced impedance transformation to a 50 Ω coaxial input. Agreement between simulated and experimental results is shown.

  16. Resonance Enhanced Multi-photon Spectroscopy of DNA

    Science.gov (United States)

    Ligare, Marshall Robert

    For over 50 years DNA has been studied to better understand its connection to life and evolution. These past experiments have led to our understanding of its structure and function in the biological environment but the interaction of DNA with UV radiation at the molecular level is still not very well understood. Unique mechanisms in nucleobase chromaphores protect us from adverse chemical reactions after UV absorption. Studying these processes can help develop theories for prebiotic chemistry and the possibility of alternative forms of DNA. Using resonance enhanced multi-photon spectroscopic techniques in the gas phase allow for the structure and dynamics of individual nucleobases to be studied in detail. Experiments studying different levels of structure/complexity with relation to their biological function are presented. Resonant IR multiphoton dissociation spectroscopy in conjunction with molecular mechanics and DFT calculations are used to determine gas phase structures of anionic nucleotide clusters. A comparison of the identified structures with known biological function shows how the hydrogen bonding of the nucleotides and their clusters free of solvent create favorable structures for quick incorporation into enzymes such as DNA polymerase. Resonance enhanced multi-photon ionization (REMPI) spectroscopy techniques such as resonant two photon ionization (R2PI) and IR-UV double resonance are used to further elucidate the structure and excited state dynamics of the bare nucleobases thymine and uracil. Both exhibit long lived excited electronic states that have been implicated in DNA photolesions which can ultimately lead to melanoma and carcinoma. Our experimental data in comparison with many quantum chemical calculations suggest a new picture for the dynamics of thymine and uracil in the gas phase. A high probability of UV absorption from a vibrationally hot ground state to the excited electronic state shows that the stability of thymine and uracil comes from

  17. Acoustic resonance spectroscopy (ARS): ARS300 operations manual, software version 2.01

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-07-25

    Acoustic Resonance Spectroscopy (ARS) is a nondestructive evaluation technology developed at the Los Alamos National Laboratory. The ARS technique is a fast, safe, and nonintrusive technique that is particularly useful when a large number of objects need to be tested. Any physical object, whether solid, hollow, or fluid filled, has many modes of vibration. These modes of vibration, commonly referred to as the natural resonant modes or resonant frequencies, are determined by the object`s shape, size, and physical properties, such as elastic moduli, speed of sound, and density. If the object is mechanically excited at frequencies corresponding to its characteristic natural vibrational modes, a resonance effect can be observed when small excitation energies produce large amplitude vibrations in the object. At other excitation frequencies, i.e., vibrational response of the object is minimal.

  18. Gravity resonance spectroscopy constrains dark energy and dark matter scenarios.

    Science.gov (United States)

    Jenke, T; Cronenberg, G; Burgdörfer, J; Chizhova, L A; Geltenbort, P; Ivanov, A N; Lauer, T; Lins, T; Rotter, S; Saul, H; Schmidt, U; Abele, H

    2014-04-18

    We report on precision resonance spectroscopy measurements of quantum states of ultracold neutrons confined above the surface of a horizontal mirror by the gravity potential of Earth. Resonant transitions between several of the lowest quantum states are observed for the first time. These measurements demonstrate that Newton's inverse square law of gravity is understood at micron distances on an energy scale of 10-14  eV. At this level of precision, we are able to provide constraints on any possible gravitylike interaction. In particular, a dark energy chameleon field is excluded for values of the coupling constant β>5.8×108 at 95% confidence level (C.L.), and an attractive (repulsive) dark matter axionlike spin-mass coupling is excluded for the coupling strength gsgp>3.7×10-16 (5.3×10-16) at a Yukawa length of λ=20  μm (95% C.L.).

  19. Gravity Resonance Spectroscopy Constrains Dark Energy and Dark Matter Scenarios

    Science.gov (United States)

    Jenke, T.; Cronenberg, G.; Burgdörfer, J.; Chizhova, L. A.; Geltenbort, P.; Ivanov, A. N.; Lauer, T.; Lins, T.; Rotter, S.; Saul, H.; Schmidt, U.; Abele, H.

    2014-04-01

    We report on precision resonance spectroscopy measurements of quantum states of ultracold neutrons confined above the surface of a horizontal mirror by the gravity potential of Earth. Resonant transitions between several of the lowest quantum states are observed for the first time. These measurements demonstrate that Newton's inverse square law of gravity is understood at micron distances on an energy scale of 10-14 eV. At this level of precision, we are able to provide constraints on any possible gravitylike interaction. In particular, a dark energy chameleon field is excluded for values of the coupling constant β >5.8×108 at 95% confidence level (C.L.), and an attractive (repulsive) dark matter axionlike spin-mass coupling is excluded for the coupling strength gsgp>3.7×10-16 (5.3×10-16) at a Yukawa length of λ =20 μm (95% C.L.).

  20. Breathers in Josephson junction ladders: resonances and electromagnetic wave spectroscopy.

    Science.gov (United States)

    Miroshnichenko, A E; Flach, S; Fistul, M V; Zolotaryuk, Y; Page, J B

    2001-12-01

    We present a theoretical study of the resonant interaction between dynamical localized states (discrete breathers) and linear electromagnetic excitations (EE's) in Josephson junction ladders. By making use of direct numerical simulations we find that such an interaction manifests itself by resonant steps and various sharp switchings (voltage jumps) in the current-voltage characteristics. Moreover, the power of ac oscillations away from the breather center (the breather tail) displays singularities as the externally applied dc bias decreases. All these features may be mapped to the spectrum of EE's that has been derived analytically and numerically. Using an improved analysis of the breather tail, a spectroscopy of the EE's is developed. The nature of breather instability driven by localized EE's is established.

  1. Magnetic Resonance Imaging and Spectroscopy in Cancer Theranostic Imaging.

    Science.gov (United States)

    Penet, Marie-France; Jin, Jiefu; Chen, Zhihang; Bhujwalla, Zaver M

    2016-10-01

    With its exquisite anatomical resolution and wide-ranging functional imaging capabilities, magnetic resonance imaging (MRI) has found multiple applications in detection, staging, and monitoring treatment response in cancer. The metabolic information provided by magnetic resonance spectroscopy (MRS) is being actively investigated to complement MRI parameters, as well as existing biomarkers, in cancer detection and in monitoring response to treatment. Located at the interface of detection and therapy, theranostic imaging is a rapidly expanding new field that is showing significant promise for precision medicine of cancer. Innovations in the development of novel nanoparticles decorated with imaging reporters that can be used to deliver therapeutic cargo to specific cells and environments have provided new roles for MRI and MRS in theranostic imaging.

  2. Resonance Raman spectroscopy in one-dimensional carbon materials

    Directory of Open Access Journals (Sweden)

    Dresselhaus Mildred S.

    2006-01-01

    Full Text Available Brazil has played an important role in the development and use of resonance Raman spectroscopy as a powerful characterization tool for materials science. Here we present a short history of Raman scattering research in Brazil, highlighting the important contributions to the field coming from Brazilian researchers in the past. Next we discuss recent and important contributions where Brazil has become a worldwide leader, that is on the physics of quasi-one dimensional carbon nanotubes. We conclude this article by presenting results from a very recent resonance Raman study of exciting new materials, that are strictly one-dimensional carbon chains formed by the heat treatment of very pure double-wall carbon nanotube samples.

  3. Susceptibility-Weighted Imaging and Magnetic Resonance Spectroscopy in Concussion.

    Science.gov (United States)

    Kirov, Ivan I; Whitlow, Christopher T; Zamora, Carlos

    2018-02-01

    Although susceptibility-weighted imaging (SWI) studies have suggested an increased number of microhemorrhages in concussion, most show no significant differences compared with controls. There have been mixed results on using SWI to predict neurologic outcomes. Drawbacks include inability to time microhemorrhages and difficulty in attributing them to the concussion. Magnetic resonance spectroscopy (MRS) in concussion can identify metabolic abnormalities, with many studies showing correlations with clinical outcome. Applications in individual patients are impeded by conflicting data and lack of consensus on an optimal protocol. Therefore, currently MRS has most utility in group-level comparisons designed to reveal the pathophysiology of concussion. Copyright © 2017 Elsevier Inc. All rights reserved.

  4. Collinear Resonance Ionization Spectroscopy of Neutron-Deficient Francium Isotopes

    CERN Document Server

    Flanagan, K T; Ruiz, R F Garcia; Budincevic, I; Procter, T J; Fedosseev, V N; Lynch, K M; Cocolios, T E; Marsh, B A; Neyens, G; Strashnov, I; Stroke, H H; Rossel, R E; Heylen, H; Billowes, J; Rothe, S; Bissell, M L; Wendt, K D A; de Groote, R P; De Schepper, S

    2013-01-01

    The magnetic moments and isotope shifts of the neutron-deficient francium isotopes Fr202-205 were measured at ISOLDE-CERN with use of collinear resonance ionization spectroscopy. A production-to-detection efficiency of 1\\% was measured for Fr-202. The background from nonresonant and collisional ionization was maintained below one ion in 10(5) beam particles. Through a comparison of the measured charge radii with predictions from the spherical droplet model, it is concluded that the ground-state wave function remains spherical down to Fr-205, with a departure observed in Fr-203 (N = 116).

  5. Neutron resonance spin echo spectroscopy on split modes

    Energy Technology Data Exchange (ETDEWEB)

    Habicht, K [Helmholtz-Zentrum Berlin fuer Materialien und Energie, Lise-Meitner-Campus, Hahn-Meitner Platz 1, D-14109 Berlin (Germany); Enderle, M [Institut Laue-Langevin, BP 156-38042 Grenoble Cedex 9 (France); Faak, B [Commissariat a l' Energie Atomique, INAC, SPSMS, 38054 Grenoble (France); Hradil, K [Institut fuer Physikalische Chemie, Georg-August-Universitaet Goettingen, Aussenstelle am FRM II, Lichtenbergstrasse 1, D-85747 Garching (Germany); Boeni, P [Physik-Department E21, Technische Universitaet Muenchen, D-85747 Garching (Germany); Keller, T, E-mail: habicht@helmholtz-berlin.d [ZWE FRMII, TU Munich, Lichtenbergstrasse 1, D-85747 Garching (Germany)

    2010-02-01

    We present an analytical formalism investigating effects of multiple excitations with different dispersion parameters in the context of neutron resonance spin echo spectroscopy. This allows identifying conditions to obtain high-resolution information on the energy split of two dispersive modes which may differ or not in their local energy gradient. Comparison to experimental data is provided by recent measurements on magnon excitations in RbMnF{sub 3}. Potential future applications are investigations of hybridized phonon or magnon modes or mixed excitations.

  6. Collinear Resonance Ionization Spectroscopy of Neutron-Deficient Francium Isotopes

    Science.gov (United States)

    Flanagan, K. T.; Lynch, K. M.; Billowes, J.; Bissell, M. L.; Budinčević, I.; Cocolios, T. E.; de Groote, R. P.; De Schepper, S.; Fedosseev, V. N.; Franchoo, S.; Garcia Ruiz, R. F.; Heylen, H.; Marsh, B. A.; Neyens, G.; Procter, T. J.; Rossel, R. E.; Rothe, S.; Strashnov, I.; Stroke, H. H.; Wendt, K. D. A.

    2013-11-01

    The magnetic moments and isotope shifts of the neutron-deficient francium isotopes Fr202-205 were measured at ISOLDE-CERN with use of collinear resonance ionization spectroscopy. A production-to-detection efficiency of 1% was measured for Fr202. The background from nonresonant and collisional ionization was maintained below one ion in 105 beam particles. Through a comparison of the measured charge radii with predictions from the spherical droplet model, it is concluded that the ground-state wave function remains spherical down to Fr205, with a departure observed in Fr203 (N=116).

  7. Assessment of trabecular bone tissue elasticity with resonant ultrasound spectroscopy.

    Science.gov (United States)

    Daoui, H; Cai, X; Boubenider, F; Laugier, P; Grimal, Q

    2017-10-01

    The material properties of the trabeculae (tissue-level properties), together with the trabecular architecture and the bone volume fraction determine the apparent millimetre-scale bone mechanical properties. We present a novel method to measure trabecular tissue elastic modulus Et using resonant ultrasound spectroscopy (RUS). The first mechanical resonance frequency fe of a freestanding cuboid specimen is measured and used to back-calculate Et. The steps of the back-calculation are (1) the apparent stiffness tensors C(Et˜) is computed using micro-finite elements for a set of trial values of tissue Young's modulus Et˜ based on the computed tomography image of the specimen; (2) the modeled free-vibration resonance frequencies fm(Et˜) of the specimen is calculated with the Rayleigh-Ritz method using C(Et˜); (3) finally, Et is obtained by interpolation using fe and fm(Et˜). Four bovine bone specimens were tested (nominal size 5×6 ×6mm3). Average (standard deviation) of Et was 13.12 (1.06)GPa. The measurement of a single resonance frequency enabled an estimation of tissue elasticity in line with available data. RUS is a non destructive technique relatively easy to implement compared to traditional mechanical testing. The novel method could contribute to a better documentation of bone tissue elasticity which is an important parameter of micro-finite element analyses for the clinical assessment of bone strength. Copyright © 2017 Elsevier Ltd. All rights reserved.

  8. Monitoring temozolomide treatment of low-grade glioma with proton magnetic resonance spectroscopy

    DEFF Research Database (Denmark)

    Murphy, P. S.; Viviers, L; Abson, C

    2004-01-01

    Assessment of low-grade glioma treatment response remains as much of a challenge as the treatment itself. Proton magnetic resonance spectroscopy ((1)H-MRS) and imaging were incorporated into a study of patients receiving temozolomide therapy for low-grade glioma in order to evaluate and monitor...... tumour metabolite and volume changes during treatment. Patients (n=12) received oral temozolomide (200 mg m(-2) day(-1)) over 5 days on a 28-day cycle for 12 cycles. Response assessment included baseline and three-monthly magnetic resonance imaging studies (pretreatment, 3, 6, 9 and 12 months) assessing...

  9. Applying nonlinear resonant ultrasound spectroscopy to improving thermal damage assessment in concrete.

    Science.gov (United States)

    Payan, C; Garnier, V; Moysan, J; Johnson, P A

    2007-04-01

    Nonlinear resonant ultrasound spectroscopy (NRUS) consists of evaluating one or more resonant frequency peak shifts while increasing excitation amplitude. NRUS exhibits high sensitivity to global damage in a large group of materials. Most studies conducted to date are aimed at interrogating the mechanical damage influence on the nonlinear response, applying bending, or longitudinal modes. The sensitivity of NRUS using longitudinal modes and the comparison of the results with a classical linear method to monitor progressive thermal damage (isotropic) of concrete are studied in this paper. In addition, feasibility and sensitivity of applying shear modes for the NRUS method are explored.

  10. Bayesian inference of elastic properties with resonant ultrasound spectroscopy.

    Science.gov (United States)

    Bales, Ben; Petzold, Linda; Goodlet, Brent R; Lenthe, William C; Pollock, Tresa M

    2018-01-01

    Bayesian modeling and Hamiltonian Monte Carlo (HMC) are utilized to formulate a robust algorithm capable of simultaneously estimating anisotropic elastic properties and crystallographic orientation of a specimen from a list of measured resonance frequencies collected via Resonance Ultrasound Spectroscopy (RUS). Unlike typical optimization procedures which yield point estimates of the unknown parameters, computing a Bayesian posterior yields probability distributions for the unknown parameters, and HMC is an efficient way to compute this posterior. The algorithms described are demonstrated on RUS data collected from two parallelepiped specimens of structural metal alloys. First, the elastic constants for a specimen of fine-grain polycrystalline Ti-6Al-4 V with random crystallographic texture and isotropic elastic symmetry are estimated. Second, the elastic constants and crystallographic orientation for a single crystal Ni-based superalloy CMSX-4 specimen are accurately determined, using only measurements of the specimen geometry, mass, and resonance frequencies. The unique contributions of this paper are as follows: the application of HMC for sampling the Bayesian posterior of a probabilistic RUS model, and the procedure for simultaneous estimation of elastic constants and lattice-specimen misorientation. Compared to previous approaches these algorithms demonstrate superior convergence behavior, particularly when the initial parameterization is unknown, and enable substantially simplified experimental procedures.

  11. Magnetic resonance imaging and spectroscopy at ultra high fields

    Energy Technology Data Exchange (ETDEWEB)

    Neuberger, Thomas

    2009-06-23

    The goal of the work presented in this thesis was to explore the possibilities and limitations of MRI / MRS using an ultra high field of 17.6 tesla. A broad range of specific applications and MR methods, from MRI to MRSI and MRS were investigated. The main foci were on sodium magnetic resonance spectroscopic imaging of rodents, magnetic resonance spectroscopy of the mouse brain, and the detection of small amounts of iron labeled stem cells in the rat brain using MRI Sodium spectroscopic imaging was explored since it benefits tremendously from the high magnetic field. Due to the intrinsically low signal in vivo, originating from the low concentrations and short transverse relaxation times, only limited results have been achieved by other researchers until now. Results in the literature include studies conducted on large animals such as dogs to animals as small as rats. No studies performed on mice have been reported, despite the fact that the mouse is the most important laboratory animal due to the ready availability of transgenic strains. Hence, this study concentrated on sodium MRSI of small rodents, mostly mice (brain, heart, and kidney), and in the case of the brain on young rats. The second part of this work concentrated on proton magnetic resonance spectroscopy of the rodent brain. Due to the high magnetic field strength not only the increasing signal but also the extended spectral resolution was advantageous for such kind of studies. The difficulties/limitations of ultra high field MRS were also investigated. In the last part of the presented work detection limits of iron labeled stem cells in vivo using magnetic resonance imaging were explored. The studies provided very useful benchmarks for future researchers in terms of the number of labeled stem cells that are required for high-field MRI studies. Overall this work has shown many of the benefits and the areas that need special attention of ultra high fields in MR. Three topics in MRI, MRS and MRSI were

  12. Localised proton magnetic resonance spectroscopy in X-linked adrenoleukodystrophy

    Energy Technology Data Exchange (ETDEWEB)

    Confort-Gouny, S. [Centre de Resonance Magnetique Biologique et Medicale (CRMBM), URA, CNRS, Faculte de Medicine, 13 - Marseille (France); Vion-Dury, J. [Centre de Resonance Magnetique Biologique et Medicale (CRMBM), URA, CNRS, Faculte de Medicine, 13 - Marseille (France); Cozzone, P.J. [Centre de Resonance Magnetique Biologique et Medicale (CRMBM), URA, CNRS, Faculte de Medicine, 13 - Marseille (France); Chabrol, B. [Service de Neuropediatrie, Hospital d`Enfants, Centre Hospitalo Universitaire, 13 - Marseille (France); Nicoli, F. [Service de Neurologie, Hopital Ste Margeurite, 13 - Marseille (France)

    1995-10-01

    We have performed localised proton magnetic resonance spectroscopy (MRS) of the brain on four patients with X-linked adrenoleukodystrophy (X-ALD). The spectrum is characterised at the beginning of the disease by a decrease in N-acetylaspartate and phosphocreatine-creatine content. Choline is strongly increased, and lactate can be detected in some cases. A proton signal from the CH{sub 2} groups borne by free intracellular very long chain fatty acids can also be observed. Later in the disease, the levels of all metabolites, in particular NAA, decrease significantly. The progression of neurometabolism documented by MRS correlates well with MRI and clinical progression on follow-up study. In one case, the metabolic profile recorded by proton MRS was abnormal before any change occurred on MRI. Proton MRS of the brain might be the method of choice for monitoring patients with X-ALD, to screen presumed cases and to study the effects of treatment. (orig.)

  13. Brain biochemistry and personality: a magnetic resonance spectroscopy study.

    Science.gov (United States)

    Ryman, Sephira G; Gasparovic, Chuck; Bedrick, Edward J; Flores, Ranee A; Marshall, Alison N; Jung, Rex E

    2011-01-01

    To investigate the biochemical correlates of normal personality we utilized proton magnetic resonance spectroscopy ((1)H-MRS). Our sample consisted of 60 subjects ranging in age from 18 to 32 (27 females). Personality was assessed with the NEO Five-Factor Inventory (NEO-FFI). We measured brain biochemistry within the precuneus, the cingulate cortex, and underlying white matter. We hypothesized that brain biochemistry within these regions would predict individual differences across major domains of personality functioning. Biochemical models were fit for all personality domains including Neuroticism, Extraversion, Openness, Agreeableness, and Conscientiousness. Our findings involved differing concentrations of Choline (Cho), Creatine (Cre), and N-acetylaspartate (NAA) in regions both within (i.e., posterior cingulate cortex) and white matter underlying (i.e., precuneus) the Default Mode Network (DMN). These results add to an emerging literature regarding personality neuroscience, and implicate biochemical integrity within the default mode network as constraining major personality domains within normal human subjects.

  14. Brain biochemistry and personality: a magnetic resonance spectroscopy study.

    Directory of Open Access Journals (Sweden)

    Sephira G Ryman

    Full Text Available To investigate the biochemical correlates of normal personality we utilized proton magnetic resonance spectroscopy ((1H-MRS. Our sample consisted of 60 subjects ranging in age from 18 to 32 (27 females. Personality was assessed with the NEO Five-Factor Inventory (NEO-FFI. We measured brain biochemistry within the precuneus, the cingulate cortex, and underlying white matter. We hypothesized that brain biochemistry within these regions would predict individual differences across major domains of personality functioning. Biochemical models were fit for all personality domains including Neuroticism, Extraversion, Openness, Agreeableness, and Conscientiousness. Our findings involved differing concentrations of Choline (Cho, Creatine (Cre, and N-acetylaspartate (NAA in regions both within (i.e., posterior cingulate cortex and white matter underlying (i.e., precuneus the Default Mode Network (DMN. These results add to an emerging literature regarding personality neuroscience, and implicate biochemical integrity within the default mode network as constraining major personality domains within normal human subjects.

  15. Review: Magnetic Resonance Spectroscopy Studies of Pediatric Major Depressive Disorder

    Directory of Open Access Journals (Sweden)

    Douglas G. Kondo

    2011-01-01

    Full Text Available Introduction. This paper focuses on the application of Magnetic Resonance Spectroscopy (MRS to the study of Major Depressive Disorder (MDD in children and adolescents. Method. A literature search using the National Institutes of Health's PubMed database was conducted to identify indexed peer-reviewed MRS studies in pediatric patients with MDD. Results. The literature search yielded 18 articles reporting original MRS data in pediatric MDD. Neurochemical alterations in Choline, Glutamate, and N-Acetyl Aspartate are associated with pediatric MDD, suggesting pathophysiologic continuity with adult MDD. Conclusions. The MRS literature in pediatric MDD is modest but growing. In studies that are methodologically comparable, the results have been consistent. Because it offers a noninvasive and repeatable measurement of relevant in vivo brain chemistry, MRS has the potential to provide insights into the pathophysiology of MDD as well as the mediators and moderators of treatment response.

  16. Collinear resonant ionization laser spectroscopy of rare francium isotopes

    CERN Document Server

    Neyens, G; Flanagan, K; Rajabali, M M; Le blanc, F M; Ware, T; Procter, T J

    2008-01-01

    We propose a programme of collinear resonant ionization spectroscopy (CRIS) of the francium isotopes up to and including $^{201}$Fr and $^{218,219}$Fr. This work aims at answering questions on the ordering of quantum states, and effect of the ($\\pi s_{1/2}^{-1}$)1/2$^{+}$ intruder state, which is currently believed to be the ground state of $^{199}$Fr. This work will also study the edge of the region of reflection asymmetry through measurement of the moments and radii of $^{218,219}$Fr. This proposal forms the first part of a series of experiments that will study nuclei in this region of the nuclear chart. Based on the success of this initial proposal it is the intention of the collaboration to perform high resolution measurements on the isotopes of radium and radon that surround $^{201}$Fr and $^{218}$Fr and thus providing a comprehensive description of the ground state properties of this region of the nuclear chart. Recent in-source spectroscopy measurements of lead, bismuth and polonium have demonstrated a...

  17. THz Electron Paramagnetic Resonance / THz Spectroscopy at BESSY II

    Directory of Open Access Journals (Sweden)

    Karsten Holldack

    2016-02-01

    Full Text Available The THz beamline at BESSY II employs high power broadband femto- to picosecond long THz pulses for magneto-optical THz and FIR studies. A newly designed set-up exploits the unique properties of ultrashort THz pulses generated by laser-energy modulation of electron bunches in the storage ring or alternatively from compressed electron bunches. Experiments from 0.15 to 5 THz (~ 5 – 150 cm-1 may be conducted at a user station equipped with a fully evacuated high resolution FTIR spectrometer (0.0063 cm-1, lHe cooled bolometer detectors, a THz TDS set-up and different sample environments, including a superconducting high field magnet (+11 T - 11T with variable temperature insert (1.5 K – 300 K, a sample cryostat and a THz attenuated total reflection chamber.  Main applications are Frequency Domain Fourier transform THz-Electron Paramagnetic Resonance (FD-FT THz-EPR, THz-FTIR spectroscopy and optical pump - THz probe time domain spectroscopy (TDS, with sub-ps time resolution.

  18. Quantitative in vivo magnetic resonance spectroscopy using synthetic signal injection.

    Science.gov (United States)

    Marro, Kenneth I; Lee, Donghoon; Shankland, Eric G; Mathis, C Mark; Hayes, Cecil E; Friedman, Seth D; Kushmerick, Martin J

    2010-12-28

    Accurate conversion of magnetic resonance spectra to quantitative units of concentration generally requires compensation for differences in coil loading conditions, the gains of the various receiver amplifiers, and rescaling that occurs during post-processing manipulations. This can be efficiently achieved by injecting a precalibrated, artificial reference signal, or pseudo-signal into the data. We have previously demonstrated, using in vitro measurements, that robust pseudo-signal injection can be accomplished using a second coil, called the injector coil, properly designed and oriented so that it couples inductively with the receive coil used to acquire the data. In this work, we acquired nonlocalized phosphorous magnetic resonance spectroscopy measurements from resting human tibialis anterior muscles and used pseudo-signal injection to calculate the Pi, PCr, and ATP concentrations. We compared these results to parallel estimates of concentrations obtained using the more established phantom replacement method. Our results demonstrate that pseudo-signal injection using inductive coupling provides a robust calibration factor that is immune to coil loading conditions and suitable for use in human measurements. Having benefits in terms of ease of use and quantitative accuracy, this method is feasible for clinical use. The protocol we describe could be readily translated for use in patients with mitochondrial disease, where sensitive assessment of metabolite content could improve diagnosis and treatment.

  19. Quantitative in vivo magnetic resonance spectroscopy using synthetic signal injection.

    Directory of Open Access Journals (Sweden)

    Kenneth I Marro

    Full Text Available Accurate conversion of magnetic resonance spectra to quantitative units of concentration generally requires compensation for differences in coil loading conditions, the gains of the various receiver amplifiers, and rescaling that occurs during post-processing manipulations. This can be efficiently achieved by injecting a precalibrated, artificial reference signal, or pseudo-signal into the data. We have previously demonstrated, using in vitro measurements, that robust pseudo-signal injection can be accomplished using a second coil, called the injector coil, properly designed and oriented so that it couples inductively with the receive coil used to acquire the data. In this work, we acquired nonlocalized phosphorous magnetic resonance spectroscopy measurements from resting human tibialis anterior muscles and used pseudo-signal injection to calculate the Pi, PCr, and ATP concentrations. We compared these results to parallel estimates of concentrations obtained using the more established phantom replacement method. Our results demonstrate that pseudo-signal injection using inductive coupling provides a robust calibration factor that is immune to coil loading conditions and suitable for use in human measurements. Having benefits in terms of ease of use and quantitative accuracy, this method is feasible for clinical use. The protocol we describe could be readily translated for use in patients with mitochondrial disease, where sensitive assessment of metabolite content could improve diagnosis and treatment.

  20. Characterization of a Continuous Wave Laser for Resonance Ionization Mass Spectroscopy Analysis in Nuclear Forensics

    Science.gov (United States)

    2015-06-01

    OF A CONTINUOUS WAVE LASER FOR RESONANCE IONIZATION MASS SPECTROSCOPY ANALYSIS IN NUCLEAR FORENSICS by Sunny G. Lau June 2015 Thesis...IONIZATION MASS SPECTROSCOPY ANALYSIS IN NUCLEAR FORENSICS 5. FUNDING NUMBERS 6. AUTHOR(S) Sunny G. Lau 7. PERFORMING ORGANIZATION NAME(S) AND...200 words) The application of resonance ionization mass spectroscopy (RIMS) to nuclear forensics involves the use of lasers to selectively ionize

  1. Evaluation of DNA damage using microwave dielectric absorption spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Hirayama, Makoto; Matuo, Youichrou; Izumi, Yoshinobu [Research Institute of Nuclear Engineering, University of Fukui, Fukui (Japan); Sunagawa, Takeyoshi [Fukui University of Technology, Fukui (Japan)

    2016-12-15

    Evaluation of deoxyribonucleic acid (DNA)-strand break is important to elucidate the biological effect of ionizing radiations. The conventional methods for DNA-strand break evaluation have been achieved by Agarose gel electrophoresis and others using an electrical property of DNAs. Such kinds of DNA-strand break evaluation systems can estimate DNA-strand break, according to a molecular weight of DNAs. However, the conventional method needs pre-treatment of the sample and a relatively long period for analysis. They do not have enough sensitivity to detect the strand break products in the low-dose region. The sample is water, methanol and plasmid DNA solution. The plasmid DNA pUC118 was multiplied by using Escherichia coli JM109 competent cells. The resonance frequency and Q-value were measured by means of microwave dielectric absorption spectroscopy. When a sample is located at a center of the electric field, resonance curve of the frequency that existed as a standing wave is disturbed. As a result, the perturbation effect to perform a resonance with different frequency is adopted. The resonance frequency shifted to higher frequency with an increase in a concentration of methanol as the model of the biological material, and the Q-value decreased. The absorption peak in microwave power spectrum of the double-strand break plasmid DNA shifted from the non-damaged plasmid DNA. Moreover, the sharpness of absorption peak changed resulting in change in Q-value. We confirmed that a resonance frequency shifted to higher frequency with an increase in concentration of the plasmid DNA. We developed a new technique for an evaluation of DNA damage. In this paper, we report the evaluation method of DNA damage using microwave dielectric absorption spectroscopy.

  2. Resonant ultrasound spectroscopy for materials with high damping and samples of arbitrary geometry

    Science.gov (United States)

    Remillieux, Marcel C.; Ulrich, T. J.; Payan, Cédric; Rivière, Jacques; Lake, Colton R.; Le Bas, Pierre-Yves

    2015-07-01

    Resonant ultrasound spectroscopy (RUS) is a powerful and established technique for measuring elastic constants of a material with general anisotropy. The first step of this technique consists of extracting resonance frequencies and damping from the vibrational frequency spectrum measured on a sample with free boundary conditions. An inversion technique is then used to retrieve the elastic tensor from the measured resonance frequencies. As originally developed, RUS has been mostly applicable to (i) materials with small damping such that the resonances of the sample are well separated and (ii) samples with simple geometries for which analytical solutions exist. In this paper, these limitations are addressed with a new RUS approach adapted to materials with high damping and samples of arbitrary geometry. Resonances are extracted by fitting a sum of exponentially damped sinusoids to the measured frequency spectrum. The inversion of the elastic tensor is achieved with a genetic algorithm, which allows searching for a global minimum within a discrete and relatively wide solution space. First, the accuracy of the proposed approach is evaluated against numerical data simulated for samples with isotropic symmetry and transversely isotropic symmetry. Subsequently, the applicability of the approach is demonstrated using experimental data collected on a composite structure consisting of a cylindrical sample of Berea sandstone glued to a large piezoelectric disk. In the proposed experiments, RUS is further enhanced by the use of a 3-D laser vibrometer allowing the visualization of most of the modes in the frequency band studied.

  3. CURRENT APPROACHES TO DIAGNOSING PROSTATE CANCER, BY APPLYING MAGNETIC RESONANCE SPECTROSCOPY (A CLINICAL STUDY

    Directory of Open Access Journals (Sweden)

    E. A. Moskalenko

    2011-01-01

    Full Text Available By evaluating abnormal metabolism, magnetic resonance spectroscopy (MRS is a highly effective tool for diagnosing prostate cancer (PC. Our study has indicated that the level of citrate (Ci and the ratio of the content of choline (Cho and creatine (Cr to that of citrate ((Cho + Cr/Ci are the most sensitive and specific indicators. These may be effectively used separately (to diagnose tumor involvement and to determine the degree of tumor differentiation and as a part of the authors’ discriminant model.The findings suggest that it is expedient to use MRS in the comprehensive diagnosis of PC.

  4. Chains, clumps, and strings: Magnetofossil taphonomy with ferromagnetic resonance spectroscopy

    Science.gov (United States)

    Kopp, Robert E.; Weiss, Benjamin P.; Maloof, Adam C.; Vali, Hojotollah; Nash, Cody Z.; Kirschvink, Joseph L.

    2006-07-01

    Magnetotactic bacteria produce intracellular crystals of magnetite or greigite, the properties of which have been shaped by evolution to maximize the magnetic moment per atom of iron. Intracellular bacterial magnetite therefore possesses traits amenable to detection by physical techniques: typically, narrow size and shape distributions, single-domain size and arrangement in linear chains, and often crystal elongation. Past strategies for searching for bacterial magnetofossils using physical techniques have focused on identifying samples containing significant amounts of single domain magnetite or with narrow coercivity distributions. Searching for additional of traits would, however, increase the likelihood that candidate magnetofossils are truly of biological origin. Ferromagnetic resonance spectroscopy (FMR) is in theory capable of detecting the distinctive magnetic anisotropy produced by chain arrangement and crystal elongation. Here we present analyses of intact and lysed magnetotactic bacteria, dilutions of synthetic magnetite, and sedimentary samples of modern carbonates from the Great Bahama Bank, Oligocene-Miocene deep-sea muds from the South Atlantic, and Pleistocene lacustrine deposits from Mono Basin, California. We demonstrate that FMR can distinguish between intact bacterial magnetite chains, collapsed chains, and linear strings of magnetite formed by physical processes. We also show that sediments in which the magnetization is likely carried by bacterial magnetite have FMR spectra resembling those of intact or altered bacterial magnetite chains.

  5. Coherent pump pulses in Double Electron Electron Resonance Spectroscopy

    Science.gov (United States)

    Tait, Claudia E.; Stoll, Stefan

    2016-01-01

    The recent introduction of shaped pulses to Double Electron Electron Resonance (DEER) spectroscopy has led to significant enhancements in sensitivity through increased excitation bandwidths and improved control over spin dynamics. The application of DEER has so far relied on the presence of an incoherent pump channel to average out most undesired coherent effects of the pump pulse(s) on the observer spins. However, in fully coherent EPR spectrometers that are increasingly used to generate shaped pulses, the presence of coherent pump pulses means that these effects need to be explicitly considered. In this paper, we examine the effects of coherent rectangular and sech/tanh pump pulses in DEER experiments with up to three pump pulses. We show that, even in the absence of significant overlap of the observer and pump pulse excitation bandwidths, coherence transfer pathways involving both types of pulses generate spin echoes of considerable intensity. These echoes introduce artefacts, which, if not identified and removed, can easily lead to misinterpretation. We demonstrate that the observed echoes can be quantitatively modelled using a simple spin quantum dynamics approach that includes instrumental transfer functions. Based on an analysis of the echo crossing artefacts, we propose efficient phase cycling schemes for their suppression. This enables the use of advanced DEER experiments, characterized by high sensitivity and increased accuracy for long-distance measurements, on novel fully coherent EPR spectrometers. PMID:27339858

  6. Magnetic Resonance Imaging (MRI and Spectroscopy (MRS in Breast Cancer

    Directory of Open Access Journals (Sweden)

    Uma Sharma

    2008-01-01

    Full Text Available Breast cancer is a major health problem in women and early detection is of prime importance. Breast magnetic resonance imaging (MRI provides both physical and physiologic tissue features that are useful in discriminating malignant from benign lesions. Contrast enhanced MRI is valuable for diagnosis of small tumors in dense breast and the structural and kinetic parameters improved the specificity of diagnosing benign from malignant lesions. It is a complimentary modality for preoperative staging, to follow response to therapy, to detect recurrences and for screening high risk women. Diffusion, perfusion and MR elastography have been applied to breast lesion characterization and show promise.In-vivo MR spectroscopy (MRS is a valuable method to obtain the biochemical status of normal and diseased tissues. Malignant tissues contain high concentration of choline containing compounds that can be used as a biochemical marker. MRS helps to increase the specificity of MRI in lesions larger than 1cm and to monitor the tumor response. Various MR techniques show promise primarily as adjunct to the existing standard detection techniques, and its acceptability as a screening method will increase if specificity can be improved. This review presents the progress made in different MRI and MRS techniques in breast cancer management.

  7. Magnetic Resonance Imaging (MRI and Spectroscopy (MRS in Breast Cancer

    Directory of Open Access Journals (Sweden)

    Uma Sharma

    2008-01-01

    Full Text Available Breast cancer is a major health problem in women and early detection is of prime importance. Breast magnetic resonance imaging (MRI provides both physical and physiologic tissue features that are useful in discriminating malignant from benign lesions. Contrast enhanced MRI is valuable for diagnosis of small tumors in dense breast and the structural and kinetic parameters improved the specificity of diagnosing benign from malignant lesions. It is a complimentary modality for preoperative staging, to follow response to therapy, to detect recurrences and for screening high risk women. Diffusion, perfusion and MR elastography have been applied to breast lesion characterization and show promise. In-vivo MR spectroscopy (MRS is a valuable method to obtain the biochemical status of normal and diseased tissues. Malignant tissues contain high concentration of choline containing compounds that can be used as a biochemical marker. MRS helps to increase the specificity of MRI in lesions larger than 1cm and to monitor the tumor response. Various MR techniques show promise primarily as adjunct to the existing standard detection techniques, and its acceptability as a screening method will increase if specificity can be improved. This review presents the progress made in different MRI and MRS techniques in beast cancer management.

  8. Measurement of anisotropic elasticity of cortical bone with resonant ultrasound spectroscopy

    OpenAIRE

    de Bernard, Simon; GRIMAL, Quentin; Haupert, Sylvain; Laugier, Pascal

    2012-01-01

    International audience; Resonant Ultrasound Spectroscopy (RUS) is a method able to precisely characterise all the terms of the stiffness tensor of an anisotropic material from a single measurement of the mechanical resonant frequencies of a sample. A previous attempt to apply this method to bone was unsuccessful due to high mechanical damping of bone which causes resonance peaks to overlap. We built a custom RUS setup and applied a signal processing method which allows retrieving resonant fre...

  9. Optically Detected Magnetic Resonance and Thermal Activation Spectroscopy Study of Organic Semiconductors

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Chang-Hwan [Iowa State Univ., Ames, IA (United States)

    2003-01-01

    Organic electronic materials are a new class of emerging materials. Organic light emitting devices (OLEDs) are the most promising candidates for future flat panel display technologies. The photophysical characterization is the basic research step one must follow to understand this new class of materials and devices. The light emission properties are closely related to the transport properties of these materials. The objective of this dissertation is to probe the relation between transport and photophysical properties of organic semiconductors. The transport characteristics were evaluated by using thermally stimulated current and thermally stimulated luminescence techniques. The photoluminescence detected magnetic resonance and photoluminescence quantum yield studies provide valuable photophysical information on this class of materials. OLEDs are already in the market. However, detailed studies on the degradation mechanisms are still lacking. Since both optically detected magnetic resonance and thermal activation spectroscopy probe long-lived defect-related states in organic semiconductors, the combined study generates new insight on the OLED operation and degradation mechanisms.

  10. Noninvasive detection of temozolomide in brain tumor xenografts by magnetic resonance spectroscopy

    DEFF Research Database (Denmark)

    Kato, Y.; Holm, David Alberg; Okollie, B.

    2010-01-01

    detection of drug directly in the tumor can be critically important for accessing, predicting, and eventually improving effectiveness of therapy. In this study, in vivo magnetic resonance spectroscopy (MRS) was used to detect an anticancer agent, temozolomide (TMZ), in vivo in murine xenotransplants of U87......MG human brain cancer. Dynamic magnetic resonance imaging (MRI) with the low-molecular-weight contrast agent, gadolinium diethylenetriaminepentaacetic acid (GdDTPA), was used to evaluate tumor vascular parameters. Carbon-13-labeled TMZ ([C-13]TMZ, 99%) was intraperitoneally administered at a dose...... experiments demonstrated slower recovery of MRI signal following an intravenous bolus injection of GdDTPA, higher vascular flow and volume obtained by T-2*-weighted MRI, as well as enhanced uptake of the contrast agent in the brain tumor compared with normal brain detected by T-1-weighted MRI. These data...

  11. High-resolution inverse Raman and resonant-wave-mixing spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Rahn, L.A. [Sandia National Laboratories, Livermore, CA (United States)

    1993-12-01

    These research activities consist of high-resolution inverse Raman spectroscopy (IRS) and resonant wave-mixing spectroscopy to support the development of nonlinear-optical techniques for temperature and concentration measurements in combustion research. Objectives of this work include development of spectral models of important molecular species needed to perform coherent anti-Stokes Raman spectroscopy (CARS) measurements and the investigation of new nonlinear-optical processes as potential diagnostic techniques. Some of the techniques being investigated include frequency-degenerate and nearly frequency-degenerate resonant four-wave-mixing (DFWM and NDFWM), and resonant multi-wave mixing (RMWM).

  12. Radiofrequency coils for magnetic resonance applications: theory, design, and evaluation.

    Science.gov (United States)

    Giovannetti, Giulio; Hartwig, Valentina; Positano, Vincenzo; Vanello, Nicola

    2014-01-01

    Magnetic resonance imaging and magnetic resonance spectroscopy are noninvasive diagnostic techniques based on the phenomenon of nuclear magnetic resonance. Radiofrequency coils are key components in both the transmission and receiving phases of magnetic resonance systems. Transmitter coils have to produce a highly homogeneous alternating field in a wide field of view, whereas receiver coils have to maximize signal detection while minimizing noise. Development of modern magnetic resonance coils often is based on numerical methods for simulating and predicting coil performance. Numerical methods allows the behavior of the coil in the presence of realistic loads to be simulated and the coil's efficiency at high magnetic fields to be investigated. After being built, coils have to be characterized in the laboratory to optimize their setting and performance by extracting several quality indices. Successively, coils performance has to be evaluated in a scanner using standardized image quality parameters with phantom and human experiments. This article reviews the principles of radiofrequency coils, coil performance parameters, and their estimation methods using simulations, workbench, and magnetic resonance experiments. Finally, an overview of future developments in radiofrequency coils technology is included.

  13. Average resonance parameters evaluation for actinides

    Energy Technology Data Exchange (ETDEWEB)

    Porodzinskij, Yu.V.; Sukhovitskij, E.Sh. [Radiation Physics and Chemistry Problems Inst., Minsk-Sosny (Belarus)

    1997-03-01

    New evaluated <{Gamma}{sub n}{sup 0}> and values for {sup 238}U, {sup 237}Np, {sup 243}Cm, {sup 245}Cm, {sup 246}Cm and {sup 241}Am nuclei in the resolved resonance region are presented. The applied method based on the idea that experimental resonance missing results in correlated changes of reduced neutron widths and level spacings distributions is discussed. (author)

  14. 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...

  15. 1H magnetic resonance spectroscopy of the brain in paediatrics: The diagnosis of creatine deficiencies

    NARCIS (Netherlands)

    Sijens, P.E.; Oudkerk, M.

    2005-01-01

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

  16. Interfacing capillary electrophoresis and surface-enhanced resonance Raman spectroscopy for the determination of dye compounds

    NARCIS (Netherlands)

    Arraez Roman, D.; Efremov, E.V.; Ariese, F.; Segura Carretero, A.; Gooijer, C.

    2005-01-01

    The at-line coupling of capillary electrophoresis (CE) and surface-enhanced resonance Raman spectroscopy (SERRS) was optimized for the separation and subsequent spectroscopic identification of charged analytes (dye compounds). Raman spectra were recorded following deposition of the electropherogram

  17. Can magnetic resonance spectroscopy differentiate malignant and benign causes of lymphadenopathy? An in-vitro approach

    National Research Council Canada - National Science Library

    Lionel Buré; Louis-Martin Boucher; Miriam Blumenkrantz; Stefan Schob; Pierre Lafaye de Micheaux; Caroline Reinhold; Benoit Gallix

    2017-01-01

    .... The goal of our research was to assess whether magnetic resonance (MR) spectroscopy contains the necessary information to allow differentiation of benign from malignant lymph nodes in an in-vitro approach using a modern pattern recognition method...

  18. Evaluating minerals of environmental concern using spectroscopy

    Science.gov (United States)

    Swayze, G.A.; Clark, R.N.; Higgins, C.T.; Kokaly, R.F.; Eric, Livo K.; Hoefen, T.M.; Ong, C.; Kruse, F.A.

    2006-01-01

    Imaging spectroscopy has been successfully used to aid researchers in characterizing potential environmental impacts posed by acid-rock drainage, ore-processing dust on mangroves, and asbestos in serpentine mineral deposits and urban dust. Many of these applications synergistically combine field spectroscopy with remote sensing data, thus allowing more-precise data calibration, spectral analysis of the data, and verification of mapping. The increased accuracy makes these environmental evaluation tools efficient because they can be used to focus field work on those areas most critical to the research effort. The use of spectroscopy to evaluate minerals of environmental concern pushes current imaging spectrometer technology to its limits; we present laboratory results that indicate the direction for future designs of imaging spectrometers.

  19. Espectroscopia de prótons e perfusão por ressonância magnética na avaliação dos tumores do sistema musculoesquelético Proton magnetic resonance spectroscopy and perfusion magnetic resonance imaging in the evaluation of musculoskeletal tumors

    Directory of Open Access Journals (Sweden)

    Flávia Martins Costa

    2009-08-01

    Full Text Available OBJETIVO: Avaliar a espectroscopia de prótons e o estudo dinâmico do contraste por ressonância magnética na diferenciação dos tumores musculoesqueléticos benignos e malignos. MATERIAIS E MÉTODOS: Foram estudados 55 pacientes com tumores musculoesqueléticos (27 malignos e 28 benignos. Os exames foram realizados em aparelho de ressonância magnética de 1.5 T com protocolo convencional e espectroscopia de prótons com TE de 135 ms. O estudo dinâmico do contraste foi adquirido pela sequência T1 gradiente-eco após a administração intravenosa de gadolínio. Curvas de intensidade de sinal versus tempo e valores de slope foram calculados. A análise estatística foi realizada pelo teste de Levene, seguido pelo teste t de Student, além dos testes qui-quadrado de Pearson e exato de Fischer. RESULTADOS: A sensibilidade, especificidade e acurácia da espectroscopia de prótons foram, respectivamente, de 87,5%, 92,3% e 90,9% (p OBJECTIVE: To assess the role of proton magnetic resonance spectroscopy and dynamic contrast-enhanced magnetic resonance imaging in the differentiation between malignant and benign musculoskeletal tumors. MATERIALS AND METHODS: Fifty-five patients with musculoskeletal tumors (27 malignant and 28 benign were studied. The examinations were performed in a 1.5 T magnetic resonance scanner with standard protocol, and single voxel proton magnetic resonance spectroscopy with 135 msec echo time. The dynamic contrast study was performed using T1-weighted gradient-echo sequence after intravenous gadolinium injection. Timesignal intensity curves and slope values were calculated. The statistical analysis was performed with the Levene's test, followed by a Student's t-test, besides the Pearson's chi-squared and Fischer's exact tests. RESULTS: Proton magnetic resonance spectroscopy sensitivity, specificity and accuracy were, respectively, 87.5%, 92.3% and 90.9% (p < 0.0001. Statistically significant difference was observed in the

  20. Resonance Raman Spectroscopy of human brain metastasis of lung cancer analyzed by blind source separation

    Science.gov (United States)

    Zhou, Yan; Liu, Cheng-Hui; Pu, Yang; Cheng, Gangge; Yu, Xinguang; Zhou, Lixin; Lin, Dongmei; Zhu, Ke; Alfano, Robert R.

    2017-02-01

    Resonance Raman (RR) spectroscopy offers a novel Optical Biopsy method in cancer discrimination by a means of enhancement in Raman scattering. It is widely acknowledged that the RR spectrum of tissue is a superposition of spectra of various key building block molecules. In this study, the Resonance Raman (RR) spectra of human metastasis of lung cancerous and normal brain tissues excited by a visible selected wavelength at 532 nm are used to explore spectral changes caused by the tumor evolution. The potential application of RR spectra human brain metastasis of lung cancer was investigated by Blind Source Separation such as Principal Component Analysis (PCA). PCA is a statistical procedure that uses an orthogonal transformation to convert a set of observations of possibly correlated variables into a set of values of linearly uncorrelated variables called principal components (PCs). The results show significant RR spectra difference between human metastasis of lung cancerous and normal brain tissues analyzed by PCA. To evaluate the efficacy of for cancer detection, a linear discriminant analysis (LDA) classifier is utilized to calculate the sensitivity, and specificity and the receiver operating characteristic (ROC) curves are used to evaluate the performance of this criterion. Excellent sensitivity of 0.97, specificity (close to 1.00) and the Area Under ROC Curve (AUC) of 0.99 values are achieved under best optimal circumstance. This research demonstrates that RR spectroscopy is effective for detecting changes of tissues due to the development of brain metastasis of lung cancer. RR spectroscopy analyzed by blind source separation may have potential to be a new armamentarium.

  1. Inductive-detection electron-spin resonance spectroscopy with 65 spins/ √{Hz } sensitivity

    Science.gov (United States)

    Probst, S.; Bienfait, A.; Campagne-Ibarcq, P.; Pla, J. J.; Albanese, B.; Da Silva Barbosa, J. F.; Schenkel, T.; Vion, D.; Esteve, D.; Mølmer, K.; Morton, J. J. L.; Heeres, R.; Bertet, P.

    2017-11-01

    We report electron spin resonance spectroscopy measurements performed at millikelvin temperatures in a custom-built spectrometer comprising a superconducting micro-resonator at 7 GHz and a Josephson parametric amplifier. Owing to the small ( ˜10-12λ3 ) magnetic resonator mode volume and to the low noise of the parametric amplifier, the spectrometer's single shot sensitivity reaches 260 ± 40 spins/echo translating into 65 ±10 spins/√{Hz } for repeated acquisition.

  2. 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.

  3. Metabolomic imaging of prostate cancer with magnetic resonance spectroscopy and mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Spur, Eva-Margarete [Massachusetts General Hospital, Harvard Medical School, Department of Pathology, Boston, MA (United States); Massachusetts General Hospital, Harvard Medical School, Department of Radiology, Boston, MA (United States); Charite Universitaetsmedizin, Berlin (Germany); Decelle, Emily A.; Cheng, Leo L. [Massachusetts General Hospital, Harvard Medical School, Department of Pathology, Boston, MA (United States); Massachusetts General Hospital, Harvard Medical School, Department of Radiology, Boston, MA (United States)

    2013-07-15

    Metabolomic imaging of prostate cancer (PCa) aims to improve in vivo imaging capability so that PCa tumors can be localized noninvasively to guide biopsy and evaluated for aggressiveness prior to prostatectomy, as well as to assess and monitor PCa growth in patients with asymptomatic PCa newly diagnosed by biopsy. Metabolomics studies global variations of metabolites with which malignancy conditions can be evaluated by profiling the entire measurable metabolome, instead of focusing only on certain metabolites or isolated metabolic pathways. At present, PCa metabolomics is mainly studied by magnetic resonance spectroscopy (MRS) and mass spectrometry (MS). With MRS imaging, the anatomic image, obtained from magnetic resonance imaging, is mapped with values of disease condition-specific metabolomic profiles calculated from MRS of each location. For example, imaging of removed whole prostates has demonstrated the ability of metabolomic profiles to differentiate cancerous foci from histologically benign regions. Additionally, MS metabolomic imaging of prostate biopsies has uncovered metabolomic expression patterns that could discriminate between PCa and benign tissue. Metabolomic imaging offers the potential to identify cancer lesions to guide prostate biopsy and evaluate PCa aggressiveness noninvasively in vivo, or ex vivo to increase the power of pathology analysis. Potentially, this imaging ability could be applied not only to PCa, but also to different tissues and organs to evaluate other human malignancies and metabolic diseases. (orig.)

  4. Breathers in Josephson junction ladders: Resonances and electromagnetic wave spectroscopy

    DEFF Research Database (Denmark)

    Miroshnichenko, A. E.; Flach, S.; Fistul, M.

    2001-01-01

    We present a theoretical study of the resonant interaction between dynamical localized states (discrete breathers) and linear electromagnetic excitations (EE's) in Josephson junction ladders. By making use of direct numerical simulations we find that such an interaction manifests itself by resonant...

  5. Vulnerable atherosclerotic plaque detection by resonance Raman spectroscopy

    Science.gov (United States)

    Liu, Cheng-hui; Boydston-White, Susie; Weisberg, Arel; Wang, Wubao; Sordillo, Laura A.; Perotte, Adler; Tomaselli, Vincent P.; Sordillo, Peter P.; Pei, Zhe; Shi, Lingyan; Alfano, Robert R.

    2016-12-01

    A clear correlation has been observed between the resonance Raman (RR) spectra of plaques in the aortic tunica intimal wall of a human corpse and three states of plaque evolution: fibrolipid plaques, calcified and ossified plaques, and vulnerable atherosclerotic plaques (VPs). These three states of atherosclerotic plaque lesions demonstrated unique RR molecular fingerprints from key molecules, rendering their spectra unique with respect to one another. The vibrational modes of lipids, cholesterol, carotenoids, tryptophan and heme proteins, the amide I, II, III bands, and methyl/methylene groups from the intrinsic atherosclerotic VPs in tissues were studied. The salient outcome of the investigation was demonstrating the correlation between RR measurements of VPs and the thickness measurements of fibrous caps on VPs using standard histopathology methods, an important metric in evaluating the stability of a VP. The RR results show that VPs undergo a structural change when their caps thin to 66 μm, very close to the 65-μm empirical medical definition of a thin cap fibroatheroma plaque, the most unstable type of VP.

  6. The magnetic resonance spectroscopy analysis for fatty acid of cooking oil

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Seung Man [Dept. of Radiological Science, College of Health Science, Gimcheon University, Gimcheon (Korea, Republic of)

    2016-11-15

    The aim of this study was to evaluate possibility for chemical changes analysis of the Soybean and Olive oil using a medical magnetic resonance imaging/spectrometer. The two edible oils including soybean and olive oil were selected for manufacturing the phantom series. For the acquisition of data without any physical environment change, 5 ml was transferred to a sealed plastic vial. All MRI and 1H-MRS experiments were performed on a 3.0 Tesla MRI scanner using a 32-channel brain array coil. The total lipid ((-CH2-)n/noise), total saturated fatty acid, total unsaturated fatty acid, total unsaturated bond, and poly unsaturated bond were quantified by separating each peak area of -CH{sub 3}, (-CH{sub 2}-)n, -CH{sub 2}-C=C-CH{sub 2}-, =C-CH{sub 2}-C=, and -CH=CH-byCH{sub 3} by MRS analysis. Soybean oil had the highest concentration of methyl protons and methane protons, expressed as 0.9 and 5.3 ppm compared to olive oil. However, its methylene protons at 1.3 ppm were the lowest. Olive oil had the highest amount of methylene protons and allylic protons and the lowest amount of methyl protons. Through the magnetic resonance spectroscopic analysis it was to analyze the chemical characteristics of Olive oil and soybean oil. And it was confirmed that it is possible to proceed to an extended study using magnetic resonance spectroscopy.

  7. Bithiophene radical cation: Resonance Raman spectroscopy and molecular orbital calculations

    DEFF Research Database (Denmark)

    Grage, M.M.-L.; Keszthelyi, T.; Offersgaard, J.F.

    1998-01-01

    The resonance Raman spectrum of the photogenerated radical cation of bithiophene is reported. The bithiophene radical cation was produced via a photoinduced electron transfer reaction between excited bithiophene and the electron acceptor fumaronitrile in a room temperature acetonitrile solution a...

  8. Cellular solid-state Nuclear Magnetic Resonance spectroscopy

    NARCIS (Netherlands)

    Renault, M.A.M.; Tommassen-van Boxtel, H.A.M.; Bos, M.P.; Post, J.A.; Tommassen, J.P.M.; Baldus, M.

    2012-01-01

    Decrypting the structure, function, and molecular interactions of complex molecular machines in their cellular context and at atomic resolution is of prime importance for understanding fundamental physiological processes. Nuclear magnetic resonance is a wellestablished imaging method that can

  9. Medulloblastoma: correlation among findings of conventional magnetic resonance imaging, diffusion-weighted imaging and proton magnetic resonance spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Fonte, Mariana Vieira de Melo da; Otaduy, Maria Concepcion Garcia; Lucato, Leandro Tavares; Reed, Umbertina Conti; Leite, Claudia da Costa [Universidade de Sao Paulo (USP), Sao Paulo, SP (Brazil). Hospital das Clinicas. Inst. de Radiologia]. E-mail: mvmfonte@uol.com.br; Costa, Maria Olivia Rodrigues; Amaral, Raquel Portugal Guimaraes [Universidade de Sao Paulo (USP), Sao Paulo, SP (Brazil). Faculdade de Medicina. Dept. de Radiologia; Reed, Umbertina Conti [Universidade de Sao Paulo (USP), Sao Paulo, SP (Brazil). Faculdade de Medicina. Dept. de Neurologia; Rosemberg, Sergio [Universidade de Sao Paulo (USP), Sao Paulo, SP (Brazil). Hospital das Clinicas. Dept. de Patologia

    2008-11-15

    To correlate imaging findings of medulloblastomas at conventional magnetic resonance imaging, diffusion-weighted imaging and proton magnetic resonance spectroscopy, comparing them with data in the literature. Preoperative magnetic resonance imaging studies of nine pediatric patients with histologically confirmed medulloblastomas (eight desmoplastic medulloblastoma, and one giant cell medulloblastoma) were retrospectively reviewed, considering demographics as well as tumors characteristics such as localization, morphology, signal intensity, contrast-enhancement, dissemination, and diffusion-weighted imaging and spectroscopy findings. In most of cases the tumors were centered in the cerebellar vermis (77.8%), predominantly solid (88.9%), hypointense on T 1-weighted images and intermediate/hyperintense on T 2-FLAIR-weighted images, with heterogeneous enhancement (100%), tumor dissemination/extension (77.8%) and limited water molecule mobility (100%). Proton spectroscopy acquired with STEAM technique (n = 6) demonstrated decreased Na a / Cr ratio (83.3%) and increased Co/Cr (100%) and ml/Cr (66.7%) ratios; and with PRESS technique (n = 7) demonstrated lactate peak (57.1%). Macroscopic magnetic resonance imaging findings in association with biochemical features of medulloblastomas have been useful in the differentiation among the most frequent posterior fossa tumors. (author)

  10. Coplanar photonic bandgap resonators for low temperature electron and nuclear magnetic resonance spectroscopy

    Science.gov (United States)

    Sigillito, A. J.; Tyryshkin, A. M.; Lyon, S. A.

    In recent years, superconducting coplanar waveguide (CPW) resonators have become a useful tool for low temperature pulsed electron spin resonance (ESR), even at dilution refrigerator temperatures. Their small mode volumes make CPW resonators particularly well suited to measuring small numbers of spins near the resonator surface, since in this region the spin sensitivity is very high. While these resonators have proven useful for ESR at single microwave frequencies, it is difficult to also manipulate nuclear spins in electron-nuclear-double resonance (ENDOR) experiments, since manipulation of nuclear spins requires radio frequency (RF) magnetic fields. Ideally one would simply generate these fields by passing RF currents through the CPW, but because conventional CPW resonators are capacitively coupled, they will not transmit low-frequency RF currents. In this talk, we discuss the use of one dimensional photonic bandgap (PBG) resonators to overcome this challenge. PBG resonators are a promising alternative to conventional CPW resonators since they offer high quality factors at microwave frequencies, while simultaneously allowing transmission of nonresonant RF currents below the photonic bandgap. Here, we will discuss PBG resonator designs and present data showing their use for low temperature ESR of donors in 28Si. Initial ENDOR results will also be presented.

  11. Photothermal Infrared Spectroscopy of Airborne Samples with Mechanical String Resonators

    DEFF Research Database (Denmark)

    Yamada, Shoko; Schmid, Silvan; Larsen, Tom

    2013-01-01

    the mid-infrared range. As a proof-of-concept, we sample and analyze polyvinylpyrrolidone (PVP) and the IR spectrum measured by photothermal spectroscopy matches the reference IR spectrum measured by an FTIR spectrometer. We further identify the organic surface coating of airborne TiO2 nanoparticles...

  12. Quantification of liver fat using magnetic resonance spectroscopy

    DEFF Research Database (Denmark)

    Thomsen, C; Becker, Povl Ulrik; Winkler, K

    1994-01-01

    Localized proton MR spectroscopy using stimulated echoes was used to quantify the liver fat concentration in patients with various degrees of fatty liver due to alcohol abuse. Ten patients underwent a liver biopsy followed by chemical triglyceride estimation of the fatty content. A statistically ...

  13. Electron beam imaging and spectroscopy of plasmonic nanoantenna resonances

    NARCIS (Netherlands)

    Vesseur, P.C.

    2011-01-01

    Nanoantennas are metal structures that provide strong optical coupling between a nanoscale volume and the far field. This coupling is mediated by surface plasmons, oscillations of the free electrons in the metal. Increasing the control over the resonant plasmonic field distribution opens up a wide

  14. Role of proton magnetic resonance spectroscopy in diagnosis of ...

    African Journals Online (AJOL)

    Background: Pilocytic astrocytomas are the second overall most common pediatric brain tumor. Magnetic resonance (MR) imaging is widely used in the diagnosis and follow up of pediatric patients with pilocytic astrocytomas because of its ability to provide anatomical detail. However conventional MR imaging does not ...

  15. Fast Resonance Raman Spectroscopy of a Free Radical

    DEFF Research Database (Denmark)

    Wilbrandt, Robert Walter; Pagsberg, Palle Bjørn; Hansen, K. B.

    1975-01-01

    The resonance Raman spectrum of a 10−3 molar solution of the stable diphenyl-pikryl-hydrazyl radical in benzene was obtained using a single laser pulse of 10 mJ energy and 600 ns duration from a flashlamp pumped tunable dye laser. Spectra were recorded using an image intensifier coupled to a TV...... camera and a video disk....

  16. Surface Plasmon Resonance: An Introduction to a Surface Spectroscopy Technique

    Science.gov (United States)

    Tang, Yijun; Zeng, Xiangqun; Liang, Jennifer

    2010-01-01

    Surface plasmon resonance (SPR) has become an important optical biosensing technology in the areas of biochemistry, biology, and medical sciences because of its real-time, label-free, and noninvasive nature. The high cost of commercial devices and consumables has prevented SPR from being introduced in the undergraduate laboratory. Here, we present…

  17. Ultraviolet resonance Raman spectroscopy for the detection of cocaine in oral fluid

    Science.gov (United States)

    D'Elia, Valentina; Montalvo, Gemma; Ruiz, Carmen García; Ermolenkov, Vladimir V.; Ahmed, Yasmine; Lednev, Igor K.

    2018-01-01

    Detecting and quantifying cocaine in oral fluid is of significant importance for practical forensics. Up to date, mainly destructive methods or biochemical tests have been used, while spectroscopic methods were only applied to pretreated samples. In this work, the possibility of using resonance Raman spectroscopy to detect cocaine in oral fluid without pretreating samples was tested. It was found that ultraviolet resonance Raman spectroscopy with 239-nm excitation allows for the detection of cocaine in oral fluid at 10 μg/mL level. Further method development will be needed for reaching the practically useful levels of cocaine detection.

  18. Magnetic resonance spectroscopy of normal appearing white matter in early relapsing-remitting multiple sclerosis: correlations between disability and spectroscopy

    Directory of Open Access Journals (Sweden)

    Foronda Jesus

    2004-06-01

    Full Text Available Abstract Background What currently appears to be irreversible axonal loss in normal appearing white matter, measured by proton magnetic resonance spectroscopy is of great interest in the study of Multiple Sclerosis. Our aim is to determine the axonal damage in normal appearing white matter measured by magnetic resonance spectroscopy and to correlate this with the functional disability measured by Multiple Sclerosis Functional Composite scale, Neurological Rating Scale, Ambulation Index scale, and Expanded Disability Scale Score. Methods Thirty one patients (9 male and 22 female with relapsing remitting Multiple Sclerosis and a Kurtzke Expanded Disability Scale Score of 0–5.5 were recruited from four hospitals in Andalusia, Spain and included in the study. Magnetic resonance spectroscopy scans and neurological disability assessments were performed the same day. Results A statistically significant correlation was found (r = -0.38 p Conclusions There is correlation between disability (measured by Expanded Disability Scale Score and the NAA/Cr ratio in normal appearing white matter. The lack of correlation between the NAA/Cr ratio and the Multiple Sclerosis Functional Composite score indicates that the Multiple Sclerosis Functional Composite is not able to measure irreversible disability and would be more useful as a marker in stages where axonal damage is not a predominant factor.

  19. Decay-assisted collinear resonance ionization spectroscopy: Application to neutron-deficient francium

    OpenAIRE

    K. M. Lynch; Billowes, J.; M. L. Bissell; Budinčević, I.; T. E. Cocolios; R. P. De Groote; de Schepper, S.; V. N. Fedosseev; K. T. Flanagan; Franchoo, S.; R. F. Garcia Ruiz; Heylen, H.; B. A. Marsh; Neyens, G.; T. J. Procter

    2014-01-01

    This paper reports on the hyperfine-structure and radioactive-decay studies of the neutron-deficient francium isotopes $^{202-206}$Fr performed with the Collinear Resonance Ionization Spectroscopy (CRIS) experiment at the ISOLDE facility, CERN. The high resolution innate to collinear laser spectroscopy is combined with the high efficiency of ion detection to provide a highly-sensitive technique to probe the hyperfine structure of exotic isotopes. The technique of decay-assisted laser spectros...

  20. Bayesian normal modes identification and estimation of elastic coefficients in resonant ultrasound spectroscopy

    OpenAIRE

    de Bernard, Simon; Marrelec, Guillaume; Laugier, Pascal; GRIMAL, Quentin

    2015-01-01

    International audience; Resonant ultrasound spectroscopy is an experimental technique for measuring the stiffness of anisotropic solid materials. The free vibration resonant frequencies of a specimen are measured and the stiffness coefficients of the material adjusted to minimize the difference between experimental and predicted frequencies. An issue of this inverse approach is that the measured frequencies are not easily paired with their predicted counterpart, leading to ambiguities in the ...

  1. Usefulness of 1H magnetic resonance spectroscopy in human testes: preliminary study.

    Science.gov (United States)

    Baleato-González, S; García-Figueiras, R; Santiago-Pérez, M I; Requejo-Isidro, I; Vilanova, J C

    2015-09-01

    To identify and quantify the metabolites detected on proton magnetic resonance spectroscopy ((1)H-MRS) in human testes. The institutional review board approved the study, and all patients provided informed consent. A total of 27 patients consulting the Urology Department underwent single-voxel (1)H-MRS (4000 ms repetition time [RT], 31 ms echo time [TE], 128 averages for each TE) at 1.5 T. Spectroscopy was not evaluable in one patient, and four patients had only one testis; thus, 48 testes were studied. Choline-containing compounds (Cho) and methylene lipid (Lip) values were measured and the Cho/Lip ratio was calculated. Testes were classified as normal or abnormal based on conventional magnetic resonance imaging (MRI) findings. The Mann-Whitney U-test was used for correlated data and bootstrapping to compare mean Cho/Lip ratios between normal and abnormal testes, and the area under the receiver operating characteristic curve (AUC) was calculated. Thirty testes were classified as normal and 18 as abnormal. The mean Cho/Lip ratio was 1.02±0.46 in normal testes and 0.45±0.36 in abnormal testes (Mann-Whitney U, p=0.001; bootstrapping mean difference, 0.57; 95% confidence interval (CI) 0.32-0.82; AUC=0.833). (1)H-MRS could be useful in routine clinical practice to identify the major metabolites in the testes and help discriminate between normal and abnormal testes. Copyright © 2015 The Royal College of Radiologists. Published by Elsevier Ltd. All rights reserved.

  2. Photothermal IR spectroscopy with perforated membrane micromechanical resonators

    DEFF Research Database (Denmark)

    Kurek, Maksymilian

    and temperature sensor. The string could be considered as a single filter-fiber and guaranteed relatively high overall sampling efficiency through impaction of airborne nanoparticles on the resonator surface. When the analyte, collected by the sensor, is exposed to IR radiation it absorbs light at a certain......-IR method. In order to overcome them, string resonators were replaced by membranes. A reliable sampling technique was maintained by adding perforation to membranes and thereby essentially getting membrane porous filters. Membranes gave also access to fully integrated magnetic transduction that allowed...... for significant shrinkage and simplification of the system. An analytical model of a locally heated membrane was developed and confirmed through FEM simulations. Then, low stress silicon nitride perforated membranes were fabricated and characterized using two different experimental setups that employed optical...

  3. 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.

  4. Brain changes detected by functional magnetic resonance imaging and spectroscopy in patients with Crohn's disease.

    Science.gov (United States)

    Lv, Kun; Fan, Yi-Hong; Xu, Li; Xu, Mao-Sheng

    2017-05-28

    Crohn's disease (CD) is a chronic, non-specific granulomatous inflammatory disorder that commonly affects the small intestine and is a phenotype of inflammatory bowel disease (IBD). CD is prone to relapse, and its incidence displays a persistent increase in developing countries. However, the pathogenesis of CD is poorly understood, with some studies emphasizing the link between CD and the intestinal microbiota. Specifically, studies point to the brain-gut-enteric microbiota axis as a key player in the occurrence and development of CD. Furthermore, investigations have shown white-matter lesions and neurologic deficits in patients with IBD. Based on these findings, brain activity changes in CD patients have been detected by blood oxygenation level dependent functional magnetic resonance imaging (BOLD-fMRI). BOLD-fMRI functions by detecting a local increase in relative blood oxygenation that results from neurotransmitter activity and thus reflects local neuronal firing rates. Therefore, biochemical concentrations of neurotransmitters or metabolites may change in corresponding brain regions of CD patients. To further study this phenomenon, brain changes of CD patients can be detected non-invasively, effectively and accurately by BOLD-fMRI combined with magnetic resonance spectroscopy (MRS). This approach can further shed light on the mechanisms of the occurrence and development of neurological CD. Overall, this paper reviews the current status and prospects on fMRI and MRS for evaluation of patients with CD based on the brain-gut-enteric microbiota axis.

  5. Minimal invasive gender determination of birds by means of UV-resonance Raman spectroscopy.

    Science.gov (United States)

    Harz, M; Krause, M; Bartels, T; Cramer, K; Rösch, P; Popp, J

    2008-02-15

    The identification of avian gender is important for prosperous breeding of birds. Since birds do not possess external genital organs, endoscopic investigations, blood analysis, and molecular biological methods are applied to determine the gender in monomorphic species. However, anesthesia and blood sampling impose stress on the examined bird and should be avoided in terms of animal protection. Here we report on the application of UV-resonance Raman spectroscopy as a minimal invasive method for gender determination of birds via an evaluation of feather pulp samples. Sample preparation for this investigation method is simple and facilitates a quick and easy analysis. The UV-resonance Raman spectra of the feather pulp sample extracts are dominated by DNA and protein signals. The different DNA content in male and female chicken allows for gender differentiation via its characteristic Raman fingerprint. The classification either to male or female chicken is ideally accomplished by support vector machines due to the fact that no unknown classes are involved. Recognition rates of about 95% were compared to less effective results of the unsupervised hierarchical cluster analysis. Within the scope of our investigations, principal component analysis was also applied to determine the important spectral regions for the classification of chicken's feather pulp samples.

  6. Non destructive characterization of cortical bone micro-damage by nonlinear resonant ultrasound spectroscopy.

    Science.gov (United States)

    Haupert, Sylvain; Guérard, Sandra; Peyrin, Françoise; Mitton, David; Laugier, Pascal

    2014-01-01

    The objective of the study was to evaluate the ability of a nonlinear ultrasound technique, the so-called nonlinear resonant ultrasound spectroscopy (NRUS) technique, for detecting early microdamage accumulation in cortical bone induced by four-point bending fatigue. Small parallelepiped beam-shaped human cortical bone specimens were subjected to cyclic four-point bending fatigue in several steps. The specimens were prepared to control damage localization during four-point bending fatigue cycling and to unambiguously identify resonant modes for NRUS measurements. NRUS measurements were achieved to follow the evolution of the nonlinear hysteretic elastic behavior during fatigue-induced damage. After each fatigue step, a small number of specimens was removed from the protocol and set apart to quantitatively assess the microcrack number density and length using synchrotron radiation micro-computed tomography (SR-µCT). The results showed a significant effect of damage steps on the nonlinear hysteretic elastic behavior. No significant change in the overall length of microcracks was observed in damaged regions compared to the load-free control regions. Only an increased number of shortest microcracks, those in the lowest quartile, was noticed. This was suggestive of newly formed microcracks during the early phases of damage accumulation. The variation of nonlinear hysteretic elastic behavior was significantly correlated to the variation of the density of short microcracks. Our results suggest that the nonlinear hysteretic elastic behavior is sensitive to early bone microdamage. Therefore NRUS technique can be used to monitor fatigue microdamage progression in in vitro experiments.

  7. Meson spectroscopy, resonances and scattering on the lattice

    Directory of Open Access Journals (Sweden)

    Thomas Christopher E.

    2017-01-01

    Full Text Available I discuss some recent progress in studying the spectra of mesons using first-principles lattice QCD calculations. In particular, I highlight some new results on resonances, near-threshold states and related scattering phenomena – this is an area which is very interesting experimentally and theoretically and where we have made significant advances in the last few years. I conclude with an outlook on future prospects.

  8. REFLECTANCE UV-VIS AND UV RESONANCE RAMAN SPECTROSCOPY IN CHARACTERIZATION OF KRAFT PULPS

    OpenAIRE

    Anni Lähdetie; Tiina Liitiä; Tarja Tamminen; Anna-Stiina Jääskeläinen

    2009-01-01

    Reflectance UV-Vis spectroscopy and UV resonance Raman (UVRR) spectroscopy are both nondestructive techniques that are applicable to study trace concentrations of lignin in-situ. In this study, unbleached and bleached softwood kraft pulps were analyzed by reflectance UV-Vis (k/s) and UVRR spectroscopy to follow lignin and hexenuronic acid (HexA) contents and structural changes in residual lignin. The height of the lignin band in the UV-Vis spectra (280 nm) correlated well with the lignin band...

  9. Neutron resonance spectroscopy on [sup 113]Cd to [ital E][sub [ital n

    Energy Technology Data Exchange (ETDEWEB)

    Frankle, C.M. (Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)); Sharapov, E.I.; Popov, Y.P. (Joint Institute for Nuclear Research, Dubna, Russia 141980 (Russian Federation)); Harvey, J.A.; Hill, N.W.; Weston, L.W. (Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 (United States))

    1994-12-01

    The results of a study of the compound nucleus [sup 114]Cd by neutron time-of-flight spectroscopy methods are presented. Targets of both natural cadmium and cadmium enriched in the 113 isotope were used. The neutron total capture and neutron transmission were both measured. A total of 275 new resonances were located. In addition, 102 other resonances which were previously known but not assigned to a particular cadmium isotope were definitively assigned to [sup 113]Cd. Resonance parameters [ital E][sub 0] and [ital g][Gamma][sub [ital n

  10. In vivo imaging of a stable paramagnetic probe by pulsed-radiofrequency electron paramagnetic resonance spectroscopy

    DEFF Research Database (Denmark)

    Murugesan; Cook; Devasahayam

    1997-01-01

    Imaging of free radicals by electron paramagnetic resonance (EPR) spectroscopy using time domain acquisition as in nuclear magnetic resonance (NMR) has not been attempted because of the short spin-spin relaxation times, typically under 1 μs, of most biologically relevant paramagnetic species......, Recent advances in radiofrequency (RF) electronics have enabled the generation of pulses of the order of 10-50 ns. Such short pulses provide adequate spectral coverage for EPR studies at 300 MHz resonant frequency. Acquisition of free induction decays (FID) of paramagnetic species possessing...

  11. Electron Paramagnetic Resonance Imaging and Spectroscopy of Polydopamine Radicals.

    Science.gov (United States)

    Mrówczyński, Radosław; Coy, L Emerson; Scheibe, Błażej; Czechowski, Tomasz; Augustyniak-Jabłokow, Maria; Jurga, Stefan; Tadyszak, Krzysztof

    2015-08-13

    A thorough investigation of biomimetic polydopamine (PDA) by Electron Paramagnetic Resonance (EPR) is shown. In addition, temperature dependent spectroscopic EPR data are presented in the range 3.8-300 K. Small discrepancies in magnetic susceptibility behavior are observed between previously reported melanin samples. These variations were attributed to thermally acitivated processes. More importantly, EPR spatial-spatial 2D imaging of polydopamine radicals on a phantom is presented for the first time. In consequence, a new possible application of polydopamine as EPR imagining marker is addressed.

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

    Science.gov (United States)

    Lacelle, S

    1984-01-01

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

  13. Signal processing in magnetic resonance spectroscopy with biomedical applications

    CERN Document Server

    Belkic, Dzevad

    2010-01-01

    ""a useful addition to the fields of both magnetic resonance (MR) as well as signal processing. … immensely useful as a practical resource handbook to dip into from time to time and to find specific advice on issues faced during the course of work in MR techniques for cancer research. … the best feature of this book is how it positions the very practical area of digital signal processing in the contextual framework of a much more esoteric and fundamental field-that of quantum mechanics. The direct link between quantum-mechanical spectral analysis and rational response functions and the gene

  14. Zero-field nuclear magnetic resonance spectroscopy of viscous liquids.

    Science.gov (United States)

    Shimizu, Y; Blanchard, J W; Pustelny, S; Saielli, G; Bagno, A; Ledbetter, M P; Budker, D; Pines, A

    2015-01-01

    We report zero-field NMR measurements of a viscous organic liquid, ethylene glycol. Zero-field spectra were taken showing resolved scalar spin-spin coupling (J-coupling) for ethylene glycol at different temperatures and water contents. Molecular dynamics strongly affects the resonance linewidth, which closely follows viscosity. Quantum chemical calculations have been used to obtain the relative stability and coupling constants of all ethylene glycol conformers. The results show the potential of zero-field NMR as a probe of molecular structure and dynamics in a wide range of environments, including viscous fluids. Copyright © 2014 Elsevier Inc. All rights reserved.

  15. All-Semiconductor Plasmonic Resonator for Surface-Enhanced Infrared Absorption Spectroscopy

    Directory of Open Access Journals (Sweden)

    Wei Wei

    2017-01-01

    Full Text Available Infrared absorption spectroscopy remains a challenge due to the weak light-matter interaction between micron-wavelengthed infrared light and nano-sized molecules. A highly doped semiconductor supports intrinsic plasmon modes at infrared frequencies, and is compatible with the current epitaxial growth processing, which makes it promising for various applications. Here, we propose an all-semiconductor plasmonic resonator to enhance the infrared absorption of the adsorbed molecules. An optical model is employed to investigate the effect of structural parameters on the spectral features of the resonator and the enhanced infrared absorption characteristics are further discussed. When a molecular layer is deposited upon the resonator, the weak molecular absorption signal can be significantly enhanced. A high enhancement factor of 470 can be achieved once the resonance wavelength of the resonator is overlapped with the desired vibrational mode of the molecules. Our study offers a promising approach to engineering semiconductor optics devices for mid-infrared sensing applications.

  16. Cardiac function and lipid distribution in rats fed a high-fat diet: in vivo magnetic resonance imaging and spectroscopy.

    Science.gov (United States)

    Nagarajan, Vijayasarathi; Gopalan, Venkatesh; Kaneko, Manami; Angeli, Veronique; Gluckman, Peter; Richards, Arthur Mark; Kuchel, Philip W; Velan, S Sendhil

    2013-06-01

    Obesity is a major risk factor in the development of cardiovascular disease, type 2 diabetes, and its pathophysiological precondition insulin resistance. Very little is known about the metabolic changes that occur in the myocardium and consequent changes in cardiac function that are associated with high-fat accumulation. Therefore, cardiac function and metabolism were evaluated in control rats and those fed a high-fat diet, using magnetic resonance imaging, magnetic resonance spectroscopy, mRNA analysis, histology, and plasma biochemistry. Analysis of blood plasma from rats fed the high-fat diet showed that they were insulin resistant (P biochemistry, magnetic resonance imaging, and mRNA analysis confirmed that rats on the high-fat diet had moderate diabetes along with mild cardiac hypertrophy. The magnetic resonance spectroscopy results showed the extramyocellular lipid signal only in the spectra from high-fat diet rats, which was absent in the control diet rats. The intramyocellular lipids in high-fat diet rats was higher (8.7%) compared with rats on the control diet (6.1%). This was confirmed by electron microscope and light microscopy studies. Our results indicate that lipid accumulation in the myocardium might be an early indication of the cardiovascular pathophysiology associated with type 2 diabetes.

  17. Avaliação de foco epileptogênico do lobo temporal: correlação entre SPECT ictal, ressonância magnética e ressonância magnética com espectroscopia de prótons Evaluation of epileptogenic focus in temporal lobe: correlation between ictal brain SPECT, magnetic resonance imaging and magnetic resonance spectroscopy

    Directory of Open Access Journals (Sweden)

    Maria Elena Martins Diegues

    2004-02-01

    Full Text Available O objetivo deste trabalho foi determinar a existência de concordância entre os métodos radioisotópico e radiológico e, em caso positivo, avaliar a utilidade do SPECT ictal na determinação do foco epileptogênico. Foram realizados SPECT ictal, ressonância magnética (RM e ressonância magnética com espectroscopia de prótons (RME em seis pacientes com epilepsia de lobo temporal refratária. O SPECT ictal foi realizado após a retirada das drogas antiepilépticas durante monitoramento por vídeo-EEG, utilizando-se o 99mTc-ECD, administrado aos pacientes no início da crise. As imagens de RM foram obtidas em T1, T2 e FLAIR, com cortes de 3 e 5 mm de espessura, e a RME foi realizada com técnica PRESS, com voxel único posicionado no hipocampo, bilateralmente. A análise estatística incluiu os valores de Kappa (k, erro-padrão (ep e o nível de significância (p para a lateralização do foco. Os achados foram analisados com base na localização por EEG da descarga ictal, no tempo de duração da crise (109-280 s; média: 152 s e no tempo de administração do traçador (30-262 s; média: 96 s. Obtivemos dados correlatos em quatro pacientes (67%, com valores de k = 0,67, ep = 0,38 e p = 0,041. Concluímos que existe concordância entre SPECT ictal, RM e RME, e a utilidade do procedimento radioisotópico está relacionada aos casos em que o EEG não é diagnóstico e quando há discordância ou indefinição diagnóstica na análise comparativa entre EEG, RM e RME.The purpose of this study was to determine the degree of concordance between radiological and radioisotopic methods and, if positive, to evaluate the usefulness of ictal SPECT in the localization of the epileptogenic focus. Ictal brain SPECT, magnetic resonance imaging (MRI and magnetic resonance spectroscopy (MRS were performed on six patients with refractory temporal lobe epilepsy. Ictal SPECT was performed after withdrawal of the anti-epileptogenic drugs during video

  18. MRI and P-31 Magnetic Resonance Spectroscopy Hardware for Axillary Lymph Node Investigation at 7T

    NARCIS (Netherlands)

    Rivera, Debra S.; Wijnen, Jannie P.; van der Kemp, Wybe J. M.; Raaijmakers, Alexander J.; Luijten, Peter R.; Klomp, DWJ

    PurposeNeoadjuvant treatment response in lymph nodes predicts patient outcome, but existing methods do not track response during therapy accurately. In this study, specialized hardware was used to adapt high-field (7T) P-31 magnetic resonance spectroscopy (MRS), which has been shown to track

  19. Resonance enhanced multiphoton ionisation (REMPI) and REMPI-photoelectron spectroscopy of carbonyl sulphide and carbon disulphide

    NARCIS (Netherlands)

    Morgan, R.A.; Buma, W.J.; Baldwin, M.A.; Ascenzi, D.; Orr-Ewing, A.J.; Ashfold, M.N.R.; de Milan, J.B.; Scheper, C.R.; de Lange, C.A.

    1996-01-01

    The results of recent mass-resolved resonance enhanced multiphoton ionisation (REMPI) and REMPI-photoelectron spectroscopy (PES) studies of the sixteen valence electron molecules OCS and CS2 are used to illustrate some of the many opportunities offered by (and a few of the possible limitations

  20. H-1 magnetic resonance spectroscopy in monocarboxylate transporter 8 gene deficiency

    NARCIS (Netherlands)

    Sijens, Paul E.; Rodiger, Lars A.; Meiners, Linda C.; Lunsing, Roelineke J.

    Context: In monocarboxylate transporter 8 (MCT8) gene deficiency, a syndrome combining thyroid and neurological abnormalities, the central nervous system has not yet been characterized by magnetic resonance (MR) spectroscopy. Objective: We studied whether the degree of dysmyelinization in MCT8 gene

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

    NARCIS (Netherlands)

    VanDenThillart, G; VanWaarde, A

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

  2. Sensitivity Analysis and Requirements for Temporally and Spatially Resolved Thermometry Using Neutron Resonance Spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Fernandez, Juan Carlos [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Barnes, Cris William [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Mocko, Michael Jeffrey [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Zavorka, Lukas [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2018-01-31

    This report is intended to examine the use of neutron resonance spectroscopy (NRS) to make time- dependent and spatially-resolved temperature measurements of materials in extreme conditions. Specifically, the sensitivities of the temperature estimate on neutron-beam and diagnostic parameters is examined. Based on that examination, requirements are set on a pulsed neutron-source and diagnostics to make a meaningful measurement.

  3. Monitoring fluoropyrimidine metabolism in solid tumors with in vivo (19)F magnetic resonance spectroscopy

    NARCIS (Netherlands)

    van Laarhoven, Hanneke W. M.; Punt, Cornelis J. A.; Kamm, Yvonne J. L.; Heerschap, Arend

    2005-01-01

    (19)Fluorine magnetic resonance spectroscopy ((19)F MRS) offers unique possibilities for monitoring the pharmacokinetics of fluoropyrimidines in vivo in tumors and normal tissue in a non-invasive way, both in animals and in patients. This method may therefore be useful for predicting response to

  4. Monitoring fluoropyrimidine metabolism in solid tumors with in vivo (19)F magnetic resonance spectroscopy.

    NARCIS (Netherlands)

    Laarhoven, H.W.M. van; Punt, C.J.A.; Kamm, Y.J.L.; Heerschap, A.

    2005-01-01

    (19)Fluorine magnetic resonance spectroscopy ((19)F MRS) offers unique possibilities for monitoring the pharmacokinetics of fluoropyrimidines in vivo in tumors and normal tissue in a non-invasive way, both in animals and in patients. This method may therefore be useful for predicting response to

  5. Cerebral metabolism, magnetic resonance spectroscopy and cognitive dysfunction in early multiple sclerosis: an exploratory study

    DEFF Research Database (Denmark)

    Blinkenberg, Morten; Mathiesen, Henrik K; Tscherning, Thomas

    2012-01-01

    OBJECTIVES: Positron emission tomography (PET) studies have shown that cortical cerebral metabolic rate of glucose (CMRglc) is reduced in multiple sclerosis (MS). Quantitative magnetic resonance spectroscopy (MRS) measures of N-acetyl-aspartate (NAA) normalized to creatine (NAA/Cr) assess neuronal...

  6. Development of resonance ionization spectroscopy system for fusion material surface analysis

    Energy Technology Data Exchange (ETDEWEB)

    Iguchi, Tetsuo [Tokyo Univ., Tokai, Ibaraki (Japan). Nuclear Engineering Research Lab.; Satoh, Yasushi; Nakazawa, Masaharu

    1996-10-01

    A Resonance Ionization Spectroscopy (RIS) system is now under development aiming at in-situ observation and analysis neutral particles emitted from fusion material surfaces under irradiation of charged particles and neutrons. The basic performance of the RIS system was checked through a preliminary experiment on Xe atom detection. (author)

  7. Electro-Optical Multichannel Spectrometer for Transient Resonance Raman and Absorption Spectroscopy

    DEFF Research Database (Denmark)

    Hansen, Karina Benthin; Wilbrandt, Robert Walter; Pagsberg, Palle Bjørn

    1979-01-01

    An optical multichannel system is described, used for time‐dependent absorption measurements in the gas phase and the liquid phase and for resonance Raman spectroscopy of short‐lived transient species in the liquid phase in pulse radiolysis. It consists of either an image converter streak unit...

  8. 2p3d Resonant X-ray emission spectroscopy of cobalt compounds

    NARCIS (Netherlands)

    van Schooneveld, M.M.|info:eu-repo/dai/nl/315032863

    2013-01-01

    This manuscript demonstrates that 2p3d resonant X-ray emission spectroscopy (RXES) yields unique information on the chemically relevant valence electrons of transition metal atoms or ions. Experimental data on cobalt compounds and several theories were used hand-in-hand. In chapter 1 2p3d RXES was

  9. Continuous Flow-Resonance Raman Spectroscopy of an Intermediate Redox State of Cytochrome-C

    DEFF Research Database (Denmark)

    Forster, M.; Hester, R. E.; Cartling, B.

    1982-01-01

    An intermediate redox state of cytochrome c at alkaline pH, generated upon rapid reduction by sodium dithionite, has been observed by resonance Raman (RR) spectroscopy in combination with the continuous flow technique. The RR spectrum of the intermediate state is reported for excitation both in t...

  10. Proton magnetic resonance spectroscopy of temporal lobe white matter in patients with histologically proven hippocampal sclerosis

    NARCIS (Netherlands)

    Meiners, LC; van der Grond, J; van Rijen, PC; Springorum, R; de Kort, GAP; Jansen, GH

    The purpose of this study was to assess temporal lobe white matter changes accompanying hippocampal sclerosis on magnetic resonance (MR) imaging using single-voxel H-1 MR spectroscopy and to strengthen the hypothesis that these white matter changes are caused by myelin alterations. In 11 patients

  11. Identification and Quantification of Copper Sites in Zeolites by Electron Paramagnetic Resonance Spectroscopy

    DEFF Research Database (Denmark)

    Godiksen, Anita; Vennestrøm, Peter N. R.; Rasmussen, Søren Birk

    2017-01-01

    Recent quantitative electron paramagnetic resonance spectroscopy (EPR) data on different copper species present in copper exchanged CHA zeolites are presented and put into context with the literature on other copper zeolites. Results presented herein were obtained using ex situ and in situ EPR...

  12. Direct rate assessment of laccase catalysed radical formation in lignin by electron paramagnetic resonance spectroscopy

    DEFF Research Database (Denmark)

    Munk, Line; Andersen, Mogens Larsen; Meyer, Anne S.

    2017-01-01

    Laccases (EC 1.10.3.2) catalyse removal of an electron and a proton from phenolic hydroxyl groups, including phenolic hydroxyls in lignins, to form phenoxy radicals during reduction of O2. We employed electron paramagnetic resonance spectroscopy (EPR) for real time measurement of such catalytic...

  13. 31P magnetic resonance spectroscopy of skeletal muscle in patients with fibromyalgia

    DEFF Research Database (Denmark)

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

    1992-01-01

    31Phosphorous nuclear magnetic resonance (31P NMR) spectroscopy of painful calf muscle was performed in 12 patients with fibromyalgia (FS) and 7 healthy subjects during rest, aerobic and anaerobic exercising conditions, and postexercise recovery. Ratios of inorganic phosphate and creatinine...

  14. Optical fiber strain sensor using fiber resonator based on frequency comb Vernier spectroscopy

    DEFF Research Database (Denmark)

    Zhang, Liang; Lu, Ping; Chen, Li

    2012-01-01

    A novel (to our best knowledge) optical fiber strain sensor using a fiber ring resonator based on frequency comb Vernier spectroscopy is proposed and demonstrated. A passively mode-locked optical fiber laser is employed to generate a phased-locked frequency comb. Strain applied to the optical fiber...

  15. Brain magnetic resonance imaging and magnetic resonance spectroscopy findings of children with kernicterus

    OpenAIRE

    Sarı, Sahabettin; Yavuz, Alpaslan; Batur, Aabdussamet; Bora, Aydın; Caksen, Huseyin

    2015-01-01

    Summary Background The term kernicterus, or bilirubin encephalopathy, is used to describe pathological bilirubin staining of the basal ganglia, brain stem, and cerebellum, and is associated with hyperbilirubinemia. Kernicterus generally occurs in untreated hyperbilirubinemia or cases where treatment is delayed. Magnetic resonance imaging (MRI)-based studies have shown characteristic findings in kernicterus. The objective of our study was to describe the role of 1H magnetic resonance spectrosc...

  16. Automated Microwave Double Resonance Spectroscopy: a Tool to Identify and Characterize Chemical Compounds

    Science.gov (United States)

    Martin-Drumel, Marie-Aline; McCarthy, Michael C.; Patterson, David; McGuire, Brett A.; Crabtree, Kyle N.

    2016-06-01

    Owing to its unparalleled structural specificity, rotational spectroscopy is a powerful technique to unambiguously identify and characterize volatile, polar molecules. We present here a new experimental approach, automated microwave double resonance (AMDOR) spectroscopy, to rapidly determine the rotational constants of these compounds without any a priori knowledge of elemental composition or molecular structure. This task is achieved by rapidly acquiring the classical (frequency vs. intensity) broadband spectrum of a molecule using chirped-pulse Fourier transform microwave (FTMW) spectroscopy, and subsequently analyzing it in near-real time using complementary cavity FTMW detection and double resonance. AMDOR measurements provide a unique ``barcode'' for each compound from which rotational constants can be extracted. To illustrate the power of this approach, AMDOR spectra of three aroma compounds --- trans-cinnamaldehyde, α- and β-ionone --- have been recorded and analyzed. The prospects to extend this approach to mixture characterization and purity assessment are described.

  17. Transmission resonance Raman spectroscopy: experimental results versus theoretical model calculations.

    Science.gov (United States)

    Gonzálvez, Alicia G; González Ureña, Ángel

    2012-10-01

    A laser spectroscopic technique is described that combines transmission and resonance-enhanced Raman inelastic scattering together with low laser power (Raman signal dependence on the sample thickness is also presented. Essentially, the model considers the sample to be homogeneous and describes the underlying physics using only three parameters: the Raman cross-section, the laser-radiation attenuation cross-section, and the Raman signal attenuation cross-section. The model was applied successfully to describe the sample-size dependence of the Raman signal in both β-carotene standards and carrot roots. The present technique could be useful for direct, fast, and nondestructive investigations in food quality control and analytical or physiological studies of animal and human tissues.

  18. Resonant three-photon ionization spectroscopy of atomic Fe

    Science.gov (United States)

    Liu, Y.; Gottwald, T.; Havener, C. C.; Mattolat, C.; Vane, C. R.; Wendt, K.

    2013-12-01

    Laser spectroscopic investigations on high-lying states around the ionization potential (IP) in the atomic spectrum of Fe have been carried out for the development of a practical three-step resonance ionization scheme accessible by Ti: sapphire lasers. A hot cavity laser ion source, typically used at on-line radioactive ion beam production facilities, was employed in this work. Ionization schemes employing high-lying Rydberg and autoionizing states populated by three-photon excitations were established. Five new Rydberg and autoionizing Rydberg series converging to the ground and to the first four excited states of Fe II are reported. Analyses of the Rydberg series yield the value 63 737.686 ± 0.068 cm-1 for the ionization potential of iron.

  19. Double resonance rotational spectroscopy of CH2D+

    Science.gov (United States)

    Töpfer, Matthias; Jusko, Pavol; Schlemmer, Stephan; Asvany, Oskar

    2016-09-01

    Context. Deuterated forms of CH are thought to be responsible for deuterium enrichment in lukewarm astronomical environments. There is no unambiguous detection of CH2D+ in space to date. Aims: Four submillimetre rotational lines of CH2D+ are documented in the literature. Our aim is to present a complete dataset of highly resolved rotational lines, including millimetre (mm) lines needed for a potential detection. Methods: We used a low-temperature ion trap and applied a novel IR-mm-wave double resonance method to measure the rotational lines of CH2D+. Results: We measured 21 low-lying (J ≤ 4) rotational transitions of CH2D+ between 23 GHz and 1.1 THz with accuracies close to 2 ppb.

  20. Applications of magnetic resonance spectroscopy to chitin from insect cuticles.

    Science.gov (United States)

    Gonil, Pattarapond; Sajomsang, Warayuth

    2012-11-01

    Chitin is the second most abundant polysaccharide in nature after cellulose. At the present time, the main commercial sources of chitin are the crab and shrimp shells which are major waste products from the seafood industry. However, current chitin resources have some inherent problems including seasonal availability, limited supplies, and environmental pollution. As an alternative, insect cuticle is proposed as an unconventional but viable source of chitin. This review focuses on the recent sources of insect chitin and the application of various magnetic resonance spectroscopic techniques to native insect cuticles, particularly cicada sloughs and chitin extracted from insect sloughs. In addition, the physicochemical properties, isolation process, and degree of N-acetylation (DA) is reviewed and discussed. Copyright © 2012 Elsevier B.V. All rights reserved.

  1. Clinical application of proton magnetic resonance spectroscopy in the diagnosis of intracranial mass lesions

    Energy Technology Data Exchange (ETDEWEB)

    Moeller-Hartmann, W.; Krings, T. [Department of Neuroradiology, University Hospital of Aachen University of Technology (Germany); Herminghaus, S.; Lanfermann, H.; Pilatus, U.; Zanella, F.E. [Department of Neuroradiology, University Hospital of Johann Wolfgang von Goethe-University, Frankfurt Main (Germany); Marquardt, G. [Clinic of Neurosurgery, University Hospital of Johann Wolfgang von Goethe-University, Frankfurt Main (Germany)

    2002-05-01

    Diagnosis of primary and secondary brain tumours and other focal intracranial mass lesions based on imaging procedures alone is still a challenging problem. Proton magnetic resonance spectroscopy ({sup 1}H-MRS) gives completely different information related to cell membrane proliferation, neuronal damage, energy metabolism and necrotic transformation of brain or tumour tissues. Our purpose was to evaluate the clinical utility of {sup 1}H-MRS added to MRI for the differentiation of intracranial neoplastic and non-neoplastic mass lesions. 176 mostly histologically verified lesions were studied with a constant clinically available single volume {sup 1}H-MRS protocol following routine MRI. 12 spectra (6.8%) were not of satisfactory diagnostic quality; 164 spectroscopic data sets were therefore available for definitive evaluation. Our study shows that spectroscopy added to MRI helps in tissue characterization of intracranial mass lesions, thereby leading to an improved diagnosis of focal brain disease. Non-neoplastic lesions such as cerebral infarctions and brain abscesses are marked by decreases in choline (Cho), creatine (Cr) and N-acetyl-aspartate (NAA), while tumours generally have elevated Cho and decreased levels of Cr and NAA. Gliomas exhibit significantly increased Cho and lipid formation with higher WHO tumour grading. Metastases have elevated Cho similar to anaplastic astrocytomas, but can be differentiated from high-grade gliomas by their higher lipid levels. Extra-axial tumours, i.e. meningiomas and neurinomas, are characterized by a nearly complete absence of the neuronal marker NAA. The additive information of {sup 1}H-MRS led to a 15.4%-higher number of correct diagnoses, to 6.2% fewer incorrect and 16% fewer equivocal diagnoses than with structural MRI data alone. (orig.)

  2. RESONANCE

    Indian Academy of Sciences (India)

    Nuclear magnetic resonance (NMR) is a mani- festation of an intrinsic property of the nucleus, i.e. nuclear spin angular momen- tum. Spin angular momentum gives rise to magnetic moments. Thus, nuclei that pos- sess net magnetic moments behave like very small bar magnets. NMR spectroscopy in- volves the study of the ...

  3. In vivo assessment of cold adaptation in insect larvae by magnetic resonance imaging and magnetic resonance spectroscopy.

    Directory of Open Access Journals (Sweden)

    Daniel Mietchen

    Full Text Available BACKGROUND: Temperatures below the freezing point of water and the ensuing ice crystal formation pose serious challenges to cell structure and function. Consequently, species living in seasonally cold environments have evolved a multitude of strategies to reorganize their cellular architecture and metabolism, and the underlying mechanisms are crucial to our understanding of life. In multicellular organisms, and poikilotherm animals in particular, our knowledge about these processes is almost exclusively due to invasive studies, thereby limiting the range of conclusions that can be drawn about intact living systems. METHODOLOGY: Given that non-destructive techniques like (1H Magnetic Resonance (MR imaging and spectroscopy have proven useful for in vivo investigations of a wide range of biological systems, we aimed at evaluating their potential to observe cold adaptations in living insect larvae. Specifically, we chose two cold-hardy insect species that frequently serve as cryobiological model systems--the freeze-avoiding gall moth Epiblema scudderiana and the freeze-tolerant gall fly Eurosta solidaginis. RESULTS: In vivo MR images were acquired from autumn-collected larvae at temperatures between 0 degrees C and about -70 degrees C and at spatial resolutions down to 27 microm. These images revealed three-dimensional (3D larval anatomy at a level of detail currently not in reach of other in vivo techniques. Furthermore, they allowed visualization of the 3D distribution of the remaining liquid water and of the endogenous cryoprotectants at subzero temperatures, and temperature-weighted images of these distributions could be derived. Finally, individual fat body cells and their nuclei could be identified in intact frozen Eurosta larvae. CONCLUSIONS: These findings suggest that high resolution MR techniques provide for interesting methodological options in comparative cryobiological investigations, especially in vivo.

  4. Magnetic effects in resonant X-ray emission spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Grebennikov, V.I. E-mail: greben@imp.uran.ru

    2004-07-01

    A theoretical description for L{sub {alpha}} and L{sub {beta}} emission spectra recorded at different excitation photon energies gives the main spectral lines: a normal emission peak, with the constant energy, and a quasi-elastic peak that moves in energy scale when the incident photon energy changes. The intensity of the quasi-elastic peak is strongly controlled by valence electron excitations due to core-hole effects. Characteristic shake-up processes give rise to double lines in spectra. Applications of resonant inelastic soft X-ray scattering for studying magnetic systems are discussed. Emission spectra (as well as absorption spectra) show the magnetic dichroism when they are excited by the polarized incident X-ray radiation. But, the emission experiments contain information on the local magnetic moment values on excited atoms even in the case of depolarized incident radiation and in disordered magnetic states. The integral intensities ratio for L{sub {beta}}/L{sub {alpha}} lines in transition metal oxides are analyzed from this point of view. The similarity of experimental X-ray fluorescent spectra with emission spectra received by electron impacts allow us to conclude that in 3d-element compounds the high-energy electron impact transfers the 2p-electron into valence states with considerable probability.

  5. Laser resonance ionization spectroscopy on lutetium for the MEDICIS project

    Science.gov (United States)

    Gadelshin, V.; Cocolios, T.; Fedoseev, V.; Heinke, R.; Kieck, T.; Marsh, B.; Naubereit, P.; Rothe, S.; Stora, T.; Studer, D.; Van Duppen, P.; Wendt, K.

    2017-11-01

    The MEDICIS-PROMED Innovative Training Network under the Horizon 2020 EU program aims to establish a network of early stage researchers, involving scientific exchange and active cooperation between leading European research institutions, universities, hospitals, and industry. Primary scientific goal is the purpose of providing and testing novel radioisotopes for nuclear medical imaging and radionuclide therapy. Within a closely linked project at CERN, a dedicated electromagnetic mass separator system is presently under installation for production of innovative radiopharmaceutical isotopes at the new CERN-MEDICIS laboratory, directly adjacent to the existing CERN-ISOLDE radioactive ion beam facility. It is planned to implement a resonance ionization laser ion source (RILIS) to ensure high efficiency and unrivaled purity in the production of radioactive ions. To provide a highly efficient ionization process, identification and characterization of a specific multi-step laser ionization scheme for each individual element with isotopes of interest is required. The element lutetium is of primary relevance, and therefore was considered as first candidate. Three two-step excitation schemes for lutetium atoms are presented in this work, and spectroscopic results are compared with data of other authors.

  6. Laser resonance ionization spectroscopy on lutetium for the MEDICIS project

    Energy Technology Data Exchange (ETDEWEB)

    Gadelshin, V., E-mail: gadelshin@uni-mainz.de [University of Mainz, Institute of Physics (Germany); Cocolios, T. [KU Leuven, Institute for Nuclear and Radiation Physics (Belgium); Fedoseev, V. [CERN, EN Department (Switzerland); Heinke, R.; Kieck, T. [University of Mainz, Institute of Physics (Germany); Marsh, B. [CERN, EN Department (Switzerland); Naubereit, P. [University of Mainz, Institute of Physics (Germany); Rothe, S.; Stora, T. [CERN, EN Department (Switzerland); Studer, D. [University of Mainz, Institute of Physics (Germany); Duppen, P. Van [KU Leuven, Institute for Nuclear and Radiation Physics (Belgium); Wendt, K. [University of Mainz, Institute of Physics (Germany)

    2017-11-15

    The MEDICIS-PROMED Innovative Training Network under the Horizon 2020 EU program aims to establish a network of early stage researchers, involving scientific exchange and active cooperation between leading European research institutions, universities, hospitals, and industry. Primary scientific goal is the purpose of providing and testing novel radioisotopes for nuclear medical imaging and radionuclide therapy. Within a closely linked project at CERN, a dedicated electromagnetic mass separator system is presently under installation for production of innovative radiopharmaceutical isotopes at the new CERN-MEDICIS laboratory, directly adjacent to the existing CERN-ISOLDE radioactive ion beam facility. It is planned to implement a resonance ionization laser ion source (RILIS) to ensure high efficiency and unrivaled purity in the production of radioactive ions. To provide a highly efficient ionization process, identification and characterization of a specific multi-step laser ionization scheme for each individual element with isotopes of interest is required. The element lutetium is of primary relevance, and therefore was considered as first candidate. Three two-step excitation schemes for lutetium atoms are presented in this work, and spectroscopic results are compared with data of other authors.

  7. Magnetic resonance spectroscopy in patients with Fabry and Gaucher disease

    Energy Technology Data Exchange (ETDEWEB)

    Gruber, S., E-mail: stephan@nmr.at [Department of Radiology, MR-Centre of Excellence, Medical University of Vienna, Waehringer Guertel 18-20, A-1090 Vienna (Austria); Bogner, W. [Department of Radiology, MR-Centre of Excellence, Medical University of Vienna, Waehringer Guertel 18-20, A-1090 Vienna (Austria); Stadlbauer, A. [MR Physics Group, Department of Radiology, Landesklinikum St. Poelten (Austria); Krssak, M. [Department of Radiology, MR-Centre of Excellence, Medical University of Vienna, Waehringer Guertel 18-20, A-1090 Vienna (Austria); Bodamer, O. [Department of Pediatrics, Medical University of Vienna (Austria)

    2011-08-15

    Objective: Fabry and Gaucher diseases are rare progressive inherited disorders of glycosphingolipid metabolism that affect multiple organ systems. The aim of this study was to investigate evidence for metabolic changes in the central nervous system involvement using proton magnetic resonance spectroscopic imaging. Methods: Seven Fabry and eight Gaucher patients were included into this study. A two-dimensional, spectroscopic imaging method with an ultra-short echo-time of 11 ms was used at a 3 T whole body magnet. Absolute metabolic values were retrieved using internal water scaling. Results were compared, with sex- and age-matched controls. Results: In contrast to previous findings, absolute and relative metabolite values of N-acetyl-aspartate (NAA) or NAA/Creatine (Cr), Cr, Choline (Cho) or Cho/Cr and myo-Inositol (mI) or mI/Cr revealed no, differences between Fabry and Gaucher Type 1 (GD1) patients and controls. Average values were, 10.22, 6.32, 2.15 and 5.39 mMol/kg wet weight for NAA, Cr, Cho and mI, respectively. In this study, we found significantly decreasing NAA/Cho with increasing age in all three groups (Fabry, GD1, patients and healthy controls) (between 5 and 8% per decade). Conclusions: There were no changes of the quantified metabolites detected by MRS in normal appearing white matter. This study shows the importance of sex- and age-matched controls.

  8. Electron paramagnetic resonance spectroscopy of lithium donors in monoisotopic silicon

    Science.gov (United States)

    Ezhevskii, Alexandr A.; Soukhorukov, Andrey V.; Guseinov, Davud V.; Gusev, Anatoly V.

    2009-12-01

    Electron paramagnetic resonance (X-band EPR) spectra are reported for lithium-related donors in monoisotopic silicon. High resolution EPR spectra of lithium donor centers in monoisotopic silicon, enriched by 28Si isotope (99.99%) with very narrow individual lines are observed. In monoisotopic silicon sample (28Si enriched floating zone silicon with low concentration of lithium 1016 cm-3), the trigonal EPR spectrum, with well resolved 7Li hyperfine structure is recorded in the temperature range 3.5-20 K. This spectrum was attributed to LiO complex. At high concentration of lithium (about 1018 cm-3) in monoisotopic silicon two types of spectra are observed. The trigonal one has the same feature as for low concentration of lithium with g-values: g∥=1.9974 and g⊥=1.9989. Another spectrum consists of two lines and has tetragonal symmetry with g∥=1.9992 and g⊥=1.9983. This spectrum is more intensive than the trigonal one and has no resolved hyperfine structure probably due to time averaging of the hyperfine interaction caused by hopping motion of electrons.

  9. Effects of Recent Concussion on Brain Bioenergetics: A Phosphorus-31 Magnetic Resonance Spectroscopy Study.

    Science.gov (United States)

    Sikoglu, Elif M; Liso Navarro, Ana A; Czerniak, Suzanne M; McCafferty, Joseph; Eisenstock, Jordan; Stevenson, J Herbert; King, Jean A; Moore, Constance M

    2015-12-01

    Although clinical evaluations and neurocognitive assessments are commonly used to evaluate the extent of and recovery from concussion, brain bioenergetics could provide a more quantitative marker. The neurometabolic response to a concussion is thought to increase neuronal energy consumption and thus the demand for nucleoside triphosphate (NTP). We investigated the possible disruption in high-energy metabolism within the prefrontal cortex of college athletes who had either had a concussion within the past 6 months (n=14) or had never had a concussion (n=13). We hypothesized that concussed athletes would have imbalanced brain bioenergetics resulting from increased NTP consumption, and these biochemical changes would correspond to impaired cognitive abilities. We used phosphorus-31 magnetic resonance spectroscopy to quantify high-energy phosphates. We performed the neuroimaging in conjunction with neurocognitive assessments targeting prefrontal cortex-mediated tasks. Our results revealed significantly lower γ-NTP levels in the athletes after concussion. Although the concussed and non-concussed participants performed similarly in neurocognitive assessments, lower levels of γ-NTP were associated with worse scores on neurocognitive tasks. Our results support the concept of increased energy demand in the prefrontal cortex of a concussed brain, and we found that while neurocognitive assessments appear normal, brain energetics may be abnormal. A longitudinal study could help establish brain NTP levels as a biomarker to aid in diagnosis and to assess recovery in concussed patients.

  10. Non-Destructive Evaluation of Materials via Ultraviolet Spectroscopy

    Science.gov (United States)

    Pugel, Betsy

    2008-01-01

    A document discusses the use of ultraviolet spectroscopy and imaging for the non-destructive evaluation of the degree of cure, aging, and other properties of resin-based composite materials. This method can be used in air, and is portable for field use. This method operates in reflectance, absorbance, and luminescence modes. The ultraviolet source is used to illuminate a composite surface of interest. In reflectance mode, the reflected response is acquired via the imaging system or via the spectrometer. The spectra are analyzed for organic compounds (conjugated organics) and inorganic compounds (semiconducting band-edge states; luminescing defect states such as silicates, used as adhesives for composite aerospace applications; and metal oxides commonly used as thermal coating paints on a wide range of spacecraft). The spectra are compared with a database for variation in conjugation, substitution, or length of molecule (in the case of organics) or band edge position (in the case of inorganics). This approach is useful in the understanding of material quality. It lacks the precision in defining the exact chemical structure that is found in other materials analysis techniques, but it is advantageous over methods such as nuclear magnetic resonance, infrared spectroscopy, and chromatography in that it can be used in the field to assess significant changes in chemical structure that may be linked to concerns associated with weaknesses or variations in structural integrity, without disassembly of or destruction to the structure of interest.

  11. Nondestructive evaluation of composite materials via scanning laser ultrasound spectroscopy

    Science.gov (United States)

    Koskelo, Elise Anne C.; Flynn, Eric B.

    2017-04-01

    Composite materials pose a complex problem for ultrasonic nondestructive evaluation due to their unique material properties, greater damping, and often complicated geometry. In this study, we explored acoustic wavenumber spectroscopy (AWS) as a means of rapid inspection of laminate and honeycomb composites. Each aerospace sample was tested at different ultrasonic frequencies using steady-state excitation via a piezo electric actuator. We measured the velocity response of the composite at each pixel via a raster scan using a laser Doppler vibrometer. We were able to detect radial inserts along corners, delamination, and facing-core separation by analyzing local amplitude and wavenumber responses. For each honeycomb composite, we excited the sample at the first resonant frequency of the individual cells. The local mode shape for each cell was extracted from the local amplitude response. Analyzing local amplitude and phase responses for each cell provided an accurate indication as to the presence, size, shape, and type of defect present in the composite. We detected both delamination and deformation of cells within a honeycomb composite. For the laminar composites, we analyzed the non-resonance steady-state response at several excitation frequencies.

  12. OXSA: An open-source magnetic resonance spectroscopy analysis toolbox in MATLAB.

    Science.gov (United States)

    Purvis, Lucian A B; Clarke, William T; Biasiolli, Luca; Valkovič, Ladislav; Robson, Matthew D; Rodgers, Christopher T

    2017-01-01

    In vivo magnetic resonance spectroscopy provides insight into metabolism in the human body. New acquisition protocols are often proposed to improve the quality or efficiency of data collection. Processing pipelines must also be developed to use these data optimally. Current fitting software is either targeted at general spectroscopy fitting, or for specific protocols. We therefore introduce the MATLAB-based OXford Spectroscopy Analysis (OXSA) toolbox to allow researchers to rapidly develop their own customised processing pipelines. The toolbox aims to simplify development by: being easy to install and use; seamlessly importing Siemens Digital Imaging and Communications in Medicine (DICOM) standard data; allowing visualisation of spectroscopy data; offering a robust fitting routine; flexibly specifying prior knowledge when fitting; and allowing batch processing of spectra. This article demonstrates how each of these criteria have been fulfilled, and gives technical details about the implementation in MATLAB. The code is freely available to download from https://github.com/oxsatoolbox/oxsa.

  13. OXSA: An open-source magnetic resonance spectroscopy analysis toolbox in MATLAB.

    Directory of Open Access Journals (Sweden)

    Lucian A B Purvis

    Full Text Available In vivo magnetic resonance spectroscopy provides insight into metabolism in the human body. New acquisition protocols are often proposed to improve the quality or efficiency of data collection. Processing pipelines must also be developed to use these data optimally. Current fitting software is either targeted at general spectroscopy fitting, or for specific protocols. We therefore introduce the MATLAB-based OXford Spectroscopy Analysis (OXSA toolbox to allow researchers to rapidly develop their own customised processing pipelines. The toolbox aims to simplify development by: being easy to install and use; seamlessly importing Siemens Digital Imaging and Communications in Medicine (DICOM standard data; allowing visualisation of spectroscopy data; offering a robust fitting routine; flexibly specifying prior knowledge when fitting; and allowing batch processing of spectra. This article demonstrates how each of these criteria have been fulfilled, and gives technical details about the implementation in MATLAB. The code is freely available to download from https://github.com/oxsatoolbox/oxsa.

  14. Gate-Tunable Resonant Raman Spectroscopy of Bilayer MoS2.

    Science.gov (United States)

    Lu, Xin; Utama, M I B; Wang, Xingzhi; Xu, Weigao; Zhao, Weijie; Owen, Man Hon Samuel; Xiong, Qihua

    2017-09-01

    The gate-tunable phonon properties in bilayer MoS2 are shown to be dependent on excitation energy. Raman intensity, Raman shift, and linewidth are affected by resonant excitation, while a nonresonant laser does not influence the intensity significantly. The gate-dependent Raman shift of A1g mode (either blue-, red-, or no-shift) is a result of the combined effect of antibonding electron and resonant-related decoupling effect. Although the decoupling effect cannot be directly measured due to the resonant background, it can be indirectly and qualitatively probed by observing A1g mode. This study on gate-tunable resonant Raman spectroscopy has clarified the influence of carrier doping on phonon properties and demonstrates a new degree of freedom in manipulating phonons in 2D material systems. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. Proton magnetic resonance spectroscopy: clinical applications in patients with brain lesions

    Directory of Open Access Journals (Sweden)

    Sérgio Luiz Ramin

    Full Text Available CONTEXT: Proton spectroscopy has been recognized as a safe and noninvasive diagnostic method that, coupled with magnetic resonance imaging techniques, allows for the correlation of anatomical and physiological changes in the metabolic and biochemical processes occurring within previously-determined volumes in the brain. There are two methods of proton magnetic resonance spectroscopy: single voxel and chemical shift imaging OBJECTIVE: The present work focused on the clinical applications of proton magnetic resonance spectroscopy in patients with brain lesions. CONCLUSIONS: In vivo proton spectroscopy allows the detection of certain metabolites in brain tissue, such as N-acetyl aspartate, creatine, choline, myoinositol, amino acids and lipids, among others. N-acetyl aspartate is a neuronal marker and, as such, its concentration will decrease in the presence of aggression to the brain. Choline increase is the main indicator of neoplastic diseases. Myoinositol is raised in patients with Alzheimer's disease. Amino acids are encountered in brain abscesses. The presence of lipids is related to necrotic processes.

  16. Investigation of natural frequencies of laser inertial confinement fusion capsules using resonant ultrasound spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Ma, Xiaojun [Institute of Modern Physics, Fudan University, Shanghai 200433 (China); Research Center of Laser Fusion, CAEP, Mianyang 621900 (China); Tang, Xing; Wang, Zongwei [Research Center of Laser Fusion, CAEP, Mianyang 621900 (China); Chen, Qian; Qian, Menglu [Institute of Acoustic, Tongji University, Shanghai 200433 (China); Meng, Jie [Research Center of Laser Fusion, CAEP, Mianyang 621900 (China); Tang, Yongjian [Institute of Modern Physics, Fudan University, Shanghai 200433 (China); Research Center of Laser Fusion, CAEP, Mianyang 621900 (China); Zou, Yaming; Shen, Hao [Institute of Modern Physics, Fudan University, Shanghai 200433 (China); Gao, Dangzhong, E-mail: dgaocn@163.com [Research Center of Laser Fusion, CAEP, Mianyang 621900 (China)

    2017-01-15

    Highlights: • The frequency equation of isotropic multi-layer hollow spheres was derived using three-dimension (3D) elasticity theory and transfer matrix method. • The natural frequencies of the capsules with a millimeter-sized diameter are determined experimentally using resonant ultrasound spectrum (RUS) system. • The predicted natural frequencies of the frequency equation accord well with the observed results. • The theoretical and experimental investigation has proved the potential applicability of RUS to both metallic and non-metallic capsules. - Abstract: The natural frequency problem of laser inertial confinement fusion (ICF) capsules is one of the basic problems for determining non-destructively the elasticity modulus of each layer material using resonant ultrasound spectroscopy (RUS). In this paper, the frequency equation of isotropic one-layer hollow spheres was derived using three dimension (3D) elasticity theory and some simplified frequency equations were discussed under axisymmetric and spherical symmetry conditions. The corresponding equation of isotropic multi-layer hollow spheres was given employing transfer matrix method. To confirm the validity of the frequency equation and explore the feasibility of RUS for characterizing the ICF capsules, three representative capsules with a millimeter-sized diameter were determined by piezoelectric-based resonant ultrasound spectroscopy (PZT-RUS) and laser-based resonant ultrasound spectroscopy (LRUS) techniques. On the basis of both theoretical and experimental results, it is proved that the calculated and measured natural frequencies are accurate enough for determining the ICF capsules.

  17. Neuroimaging in Parkinsonism: a study with magnetic resonance and spectroscopy as tools in the differential diagnosis

    Energy Technology Data Exchange (ETDEWEB)

    Vasconcellos, Luiz Felipe Rocha [1Hospital dos Servidores do Estado, Rio de Janeiro RJ (Brazil)], e-mail: luizneurol@terra.com.br; Novis, Sergio A. Pereira; Rosso, Ana Lucia Z. [Hospital Universitario Clementino Fraga Filho (HUCFF), Rio de Janeiro, RJ (Brazil); Moreira, Denise Madeira [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Inst. de Neurologia Deolindo Couto; Leite, Ana Claudia C.B. [Fundacao Oswaldo Cruz (FIOCRUZ), Rio de Janeiro, RJ (Brazil)

    2009-03-15

    The differential diagnosis of Parkinsonism based on clinical features, sometimes may be difficult. Diagnostic tests in these cases might be useful, especially magnetic resonance imaging, a noninvasive exam, not as expensive as positron emission tomography, and provides a good basis for anatomical analysis. The magnetic resonance spectroscopy analyzes cerebral metabolism, yielding inconsistent results in parkinsonian disorders. We selected 40 individuals for magnetic resonance imaging and spectroscopy analysis, 12 with Parkinson's disease, 11 with progressive supranuclear palsy, 7 with multiple system atrophy (parkinsonian type), and 10 individuals without any psychiatric or neurological disorders (controls). Clinical scales included Hoenh and Yahr, unified Parkinson's disease rating scale and mini mental status examination. The results showed that patients with Parkinson's disease and controls presented the same aspects on neuroimaging, with few or absence of abnormalities, and supranuclear progressive palsy and multiple system atrophy showed abnormalities, some of which statistically significant. Thus, magnetic resonance imaging and spectroscopy could be useful as a tool in differential diagnosis of Parkinsonism. (author)

  18. Multidimensional resonance raman spectroscopy by six-wave mixing in the deep UV

    Energy Technology Data Exchange (ETDEWEB)

    Molesky, Brian P.; Giokas, Paul G.; Guo, Zhenkun; Moran, Andrew M., E-mail: ammoran@email.unc.edu [Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599 (United States)

    2014-09-21

    Two-dimensional (2D) resonance Raman spectroscopies hold great potential for uncovering photoinduced relaxation processes in molecules but are not yet widely applied because of technical challenges. Here, we describe a newly developed 2D resonance Raman experiment operational at the third-harmonic of a Titanium-Sapphire laser. High-sensitivity and rapid data acquisition are achieved by combining spectral interferometry with a background-free (six-pulse) laser beam geometry. The third-harmonic laser pulses are generated in a filament produced by the fundamental and second-harmonic pulses in neon gas at pressures up to 35 atm. The capabilities of the setup are demonstrated by probing ground-state wavepacket motions in triiodide. The information provided by the experiment is explored with two different representations of the signal. In one representation, Fourier transforms are carried out with respect to the two experimentally controlled delay times to obtain a 2D Raman spectrum. Further insights are derived in a second representation by dispersing the signal pulse in a spectrometer. It is shown that, as in traditional pump-probe experiments, the six-wave mixing signal spectrum encodes the wavepacket's position by way of the (time-evolving) emission frequency. Anharmonicity additionally induces dynamics in the vibrational resonance frequency. In all cases, the experimental signals are compared to model calculations based on a cumulant expansion approach. This study suggests that multi-dimensional resonance Raman spectroscopies conducted on systems with Franck-Condon active modes are fairly immune to many of the technical issues that challenge off-resonant 2D Raman spectroscopies (e.g., third-order cascades) and photon-echo experiments in the deep UV (e.g., coherence spikes). The development of higher-order nonlinear spectroscopies operational in the deep UV is motivated by studies of biological systems and elementary organic photochemistries.

  19. Evaluation of toxicological effects induced by tributyltin in clam Ruditapes decussatus using high-resolution magic angle spinning nuclear magnetic resonance spectroscopy: Study of metabolic responses in heart tissue and detection of a novel metabolite.

    Science.gov (United States)

    Hanana, H; Simon, G; Kervarec, N; Cérantola, S

    2014-01-01

    Tributyltin (TBT) is a highly toxic pollutant present in many aquatic ecosystems. Its toxicity in mollusks strongly affects their performance and survival. The main purpose of this study was to elucidate the mechanisms of TBT toxicity in clam Ruditapes decussatus by evaluating the metabolic responses of heart tissues, using high-resolution magic angle-spinning nuclear magnetic resonance (HRMAS NMR), after exposure to TBT (10-9, 10-6 and 10-4 M) during 24 h and 72 h. Results show that responses of clam heart tissue to TBT exposure are not dose dependent. Metabolic profile analyses indicated that TBT 10-6 M, contrary to the two other doses tested, led to a significant depletion of taurine and betaine. Glycine levels decreased in all clam groups treated with the organotin. It is suggested that TBT abolished the cytoprotective effect of taurine, betaine and glycine thereby inducing cardiomyopathie. Moreover, results also showed that TBT induced increase in the level of alanine and succinate suggesting the occurrence of anaerobiosis particularly in clam group exposed to the highest dose of TBT. Taken together, these results demonstrate that TBT is a potential toxin with a variety of deleterious effects on clam and this organotin may affect different pathways depending to the used dose. The main finding of this study was the appearance of an original metabolite after TBT treatment likely N-glycine-N'-alanine. It is the first time that this molecule has been identified as a natural compound. Its exact role is unknown and remains to be elucidated. We suppose that its formation could play an important role in clam defense response by attenuating Ca2+ dependent cell death induced by TBT. Therefore this compound could be a promising biomarker for TBT exposure.

  20. Localised proton magnetic resonance spectroscopy of the brain after perinatal hypoxia: a preliminary report

    Energy Technology Data Exchange (ETDEWEB)

    Chateil, J.F. [Service de Radiologie A, Hopital Pellegrin, Bordeaux (France)]|[Unite de Radiopediatrie, Hopital Pellegrin, Bordeaux (France); Quesson, B.; Thiaudiere, E.; Delalande, C.; Canioni, P. [Resonance Magnetique des Systemes Biologiques, CNRS, Bordeaux (France); Brun, M.; Diard, F. [Service de Radiologie A, Hopital Pellegrin, Bordeaux (France); Sarlangue, J.; Billeaud, C. [Service de Neonatalogie, Hopital Pellegrin, Bordeaux (France)

    1999-03-01

    Objectives. Perinatal hypoxic ischaemic injury is a significant cause of neurodevelopmental impairment. The aim of this study was to evaluate localised proton magnetic resonance spectroscopy ({sup 1}H-MRS) after birth asphyxia. Materials and methods. Thirty newborn infants suspected of having perinatal asphyxia (Apgar score < 3) were studied. The mean gestational age was 37 weeks, mean age at the MR examination was 18 days and mean weight was 2.9 kg. A 1.5-T unit was used for imaging and spectroscopy. None of the babies had mechanically assisted ventilation. No sedation was used. Axial T1-weighted and T2-weighted images were obtained. {sup 1}H-MRS was recorded in a single voxel, localised in white matter, using a STEAM sequence. Results. Image quality was good in 25 of 30 babies. {sup 1}H-MRS was performed in 19 of 30 subjects, with adequate quality in 16. Choline, creatine/phosphocreatine and N-acetylaspartate peaks and peak-area ratios were analysed. Lactate was detected in four infants. The N-acetylaspartate/choline ratio was lower in infants with an impaired neurological outcome, but the difference was not statistically significant. Conclusions. This study suggests that {sup 1}H-MRS may be useful for assessing cerebral metabolism in the neonate. A raised lactate level and decreased N-acetylaspartate/choline ratio may be predictive of a poor outcome. However, in our experience this method is limited by the difficulty in performing the examination during the first hours after birth in critically ill babies, the problems related to use of a monovoxel sequence, the dispersion of the ratios and the lack of determination of the absolute concentration of the metabolites. (orig.) With 3 figs., 2 tabs., 20 refs.

  1. Non destructive characterization of cortical bone micro-damage by nonlinear resonant ultrasound spectroscopy.

    Directory of Open Access Journals (Sweden)

    Sylvain Haupert

    Full Text Available The objective of the study was to evaluate the ability of a nonlinear ultrasound technique, the so-called nonlinear resonant ultrasound spectroscopy (NRUS technique, for detecting early microdamage accumulation in cortical bone induced by four-point bending fatigue. Small parallelepiped beam-shaped human cortical bone specimens were subjected to cyclic four-point bending fatigue in several steps. The specimens were prepared to control damage localization during four-point bending fatigue cycling and to unambiguously identify resonant modes for NRUS measurements. NRUS measurements were achieved to follow the evolution of the nonlinear hysteretic elastic behavior during fatigue-induced damage. After each fatigue step, a small number of specimens was removed from the protocol and set apart to quantitatively assess the microcrack number density and length using synchrotron radiation micro-computed tomography (SR-µCT. The results showed a significant effect of damage steps on the nonlinear hysteretic elastic behavior. No significant change in the overall length of microcracks was observed in damaged regions compared to the load-free control regions. Only an increased number of shortest microcracks, those in the lowest quartile, was noticed. This was suggestive of newly formed microcracks during the early phases of damage accumulation. The variation of nonlinear hysteretic elastic behavior was significantly correlated to the variation of the density of short microcracks. Our results suggest that the nonlinear hysteretic elastic behavior is sensitive to early bone microdamage. Therefore NRUS technique can be used to monitor fatigue microdamage progression in in vitro experiments.

  2. Hypothalamic metabolic compartmentation during appetite regulation as revealed by magnetic resonance imaging and spectroscopy methods

    Directory of Open Access Journals (Sweden)

    Blanca eLizarbe

    2013-06-01

    Full Text Available We review the role of neuroglial compartmentation and transcellular neurotransmitter cycling during hypothalamic appetite regulation as detected by Magnetic Resonance Imaging (MRI and Spectroscopy (MRS methods. We address first the neurochemical basis of neuroendocrine regulation in the hypothalamus and the orexigenic and anorexigenic feed-back loops that control appetite. Then we examine the main Magnetic Resonance Imaging and Spectroscopy strategies that have been used to investigate appetite regulation. Manganese enhanced magnetic resonance imaging (MEMRI, Blood oxygenation level dependent contrast (BOLD and Diffusion weighted magnetic resonance imaging (DWI have revealed Mn2+accumulations, augmented oxygen consumptions and astrocytic swelling in the hypothalamus under fasting conditions, respectively. High field 1H magnetic resonance in vivo, showed increased hypothalamic myo-inositol concentrations as compared to other cerebral structures. 1H and 13C high resolution magic angle spinning (HRMAS revealed increased neuroglial oxidative and glycolytic metabolism, as well as increased hypothalamic glutamatergic and GABAergic neurotransmissions under orexigenic stimulation. We propose here an integrative interpretation of all these findings suggesting that the neuroendocrine regulation of appetite is supported by important ionic and metabolic transcellular fluxes which begin at the tripartite orexigenic clefts and become extended spatially in the hypothalamus through astrocytic networks, becoming eventually MRI and MRS detectable.

  3. Resonance-Enhanced Excited-State Raman Spectroscopy of Conjugated Thiophene Derivatives: Combining Experiment with Theory

    Science.gov (United States)

    Barclay, Matthew S.; Quincy, Timothy J.; Caricato, Marco; Elles, Christopher G.

    2017-06-01

    Resonance-enhanced Femtosecond Stimulated Raman Spectroscopy (FSRS) is an ultrafast experimental method that allows for the study of excited-state structural behaviors, as well as the characterization of higher electronically excited states accessible through the resonant conditions of the observed vibrations. However, interpretation of the experiment is difficult without an accurate vibrational assignment of the resonance-enhanced spectra. We therefore utilize simulations of off-resonant excited-state Raman spectra, in which we employ a numerical derivative of the analytical excited-state polarizabilities along the normal mode displacements, in order to identify and interpret the resonance-enhanced vibrations observed in experiment. We present results for a benchmark series of conjugated organic thiophene derivatives, wherein we have computed the off-resonant excited-state Raman spectra for each molecule and matched it with its resonance-enhanced experimental spectrum. This comparison allows us to successfully identify the vibrational displacements of the observed FSRS bands, as well as validate the accuracy of the theoretical results through an experimental benchmark. The agreement between the experimental and computed results demonstrates that we are able to predict qualitatively accurate excited-state Raman spectra for these conjugated thiophenes, allowing for a more thorough interpretation of excited-state Raman signals at relatively low computational cost.

  4. Neutron resonance spectroscopy on 113Cd to En=15 keV

    Science.gov (United States)

    Frankle, C. M.; Sharapov, E. I.; Popov, Yu. P.; Harvey, J. A.; Hill, N. W.; Weston, L. W.

    1994-12-01

    The results of a study of the compound nucleus 114Cd by neutron time-of-flight spectroscopy methods are presented. Targets of both natural cadmium and cadmium enriched in the 113 isotope were used. The neutron total capture and neutron transmission were both measured. A total of 275 new resonances were located. In addition, 102 other resonances which were previously known but not assigned to a particular cadmium isotope were definitively assigned to 113Cd. Resonance parameters E0 and gΓn were obtained for both newly identified and previously known resonances. Of the 437 resonances now known in 113Cd, we identify 104 of them as l=1 based on their small widths. Strength functions and level spacings are obtained for both l=0 and l=1 resonances. Comparisons of the data with Porter-Thomas reduced width distributions, Wigner nearest neighbor spacing distributions, and the Dyson-Metha Δ3 statistic are given. The linear correlation coefficient between adjacent spacings is also discussed. The spectroscopic information obtained is of importance for planning and interpretation of parity violation measurements on the p-wave resonances of 113Cd.

  5. First on-line results from the CRIS (Collinear Resonant Ionisation Spectroscopy) beam line at ISOLDE

    Energy Technology Data Exchange (ETDEWEB)

    Procter, T. J., E-mail: thomas.procter@postgrad.manchester.ac.uk; Flanagan, K. T. [University of Manchester (United Kingdom); Collaboration: CRIS Collaboration

    2013-04-15

    The CRIS (Collinear Resonant Ionisation Spectroscopy) experiment at the on-line isotope separator facility, ISOLDE, CERN, has been constructed for high-sensitivity laser spectroscopy measurements on radioactive isotopes. The technique determines the magnetic dipole and electric quadrupole moments, nuclear spin and changes in mean-square charge radii of exotic nuclei via measurement of their hyperfine structures and isotope shifts. In November 2011 the first on-line run was performed using the CRIS beam line, when the hyperfine structure of {sup 207}Fr was successfully measured. This paper will describe the technique and experimental setup of CRIS and present the results from the first on-line experiment.

  6. Theoretical analysis of a resonant quartz-enhanced photoacoustic spectroscopy sensor

    Science.gov (United States)

    Aoust, Guillaume; Levy, Raphael; Raybaut, Myriam; Godard, Antoine; Melkonian, Jean-Michel; Lefebvre, Michel

    2017-02-01

    In this paper, we report the first analytical model for quartz-enhanced photoacoustic spectroscopy in combination with an acoustic resonator. A generalized fundamental equation is proposed to model the photoacoustic effect, taking into account the coupling between the tuning fork and the surrounding fluid. The analytical signal-to-noise ratio is derived, yielding a direct physical insight with respect to the system design. Experimental behaviors are very well reproduced, and numerical finite elements methods are implemented to successfully confirm the relevance of our approach. We also provide a detailed explanation of the coupling dynamics between the quartz tuning fork and the acoustically resonant tube.

  7. The Collinear Resonance Ionization Spectroscopy (CRIS) experimental setup at CERN-ISOLDE

    Science.gov (United States)

    Cocolios, T. E.; Al Suradi, H. H.; Billowes, J.; Budinčević, I.; de Groote, R. P.; De Schepper, S.; Fedosseev, V. N.; Flanagan, K. T.; Franchoo, S.; Garcia Ruiz, R. F.; Heylen, H.; Le Blanc, F.; Lynch, K. M.; Marsh, B. A.; Mason, P. J. R.; Neyens, G.; Papuga, J.; Procter, T. J.; Rajabali, M. M.; Rossel, R. E.; Rothe, S.; Simpson, G. S.; Smith, A. J.; Strashnov, I.; Stroke, H. H.; Verney, D.; Walker, P. M.; Wendt, K. D. A.; Wood, R. T.

    2013-12-01

    The CRIS setup at CERN-ISOLDE is a laser spectroscopy experiment dedicated to the high-resolution study of the spin, hyperfine structure and isotope shift of radioactive nuclei with low production rates (a few per second). It combines the Doppler-free resolution of the in-flight collinear geometry with the high detection efficiency of resonant ionisation. A recent commissioning campaign has demonstrated a 1% experimental efficiency, and as low as a 0.001% non-resonant ionisation. The current status of the experiment and its recent achievements with beams of francium isotopes are reported. The first identified systematic effects are discussed.

  8. Observation of ballistic transport in double-barrier resonant-tunneling structures by electroluminescence spectroscopy

    Science.gov (United States)

    Teissier, R.; Cockburn, J. W.; Buckle, P. D.; Skolnick, M. S.; Finley, J. J.; Grey, R.; Hill, G.; Pate, M. A.

    1994-08-01

    We report a direct observation by electroluminescence (EL) spectroscopy of ballistic-electron transport in double-barrier resonant-tunneling GaAs/AlxGa1-xAs p-i-n diodes. The samples studied contain two confined electron states (e1 and e2) and consequently two resonances in the current versus bias characteristic. When biased for electron tunneling through e2, an analysis of EL intensities permits a quantitative determination of the ratio (1:16 and 1:203 for the two samples studied) of the ballistic current flowing directly through e2 to the current flowing sequentially through e1.

  9. Magnetic resonance spectroscopy in schizophrenia. Possibilities and limitations; Magnetresonanzspektroskopie bei Schizophrenie. Moeglichkeiten und Grenzen

    Energy Technology Data Exchange (ETDEWEB)

    Wobrock, T. [Universitaetsklinikum des Saarlandes, Homburg/Saar (Germany). Klinik fuer Psychiatrie und Psychotherapie; Universitaetsklinikum des Saarlandes, Klinik fuer Psychiatrie und Psychotherapie, Homburg/Saar (Germany); Scherk, H.; Falkai, P. [Universitaetsklinikum des Saarlandes, Homburg/Saar (Germany). Klinik fuer Psychiatrie und Psychotherapie

    2005-02-01

    Magnetic resonance spectroscopy is a noninvasive investigative technique for in vivo detection of biochemical changes in neuropsychiatric disorders for which especially proton ({sup 1}H-MRS) and phosphorus ({sup 31}P-MRS) magnetic resonance spectroscopy have been used. In this review we explain the principles of MRS and summarize the studies in schizophrenia. A systematic literature review was carried out for {sup 1}H-MRS studies investigating schizophrenic patients compared to controls. The inconsistent results in the cited studies may be due to different study population, specific neuroimaging technique, and selected brain regions. Frequent findings are decreased PME and increased PDE concentrations ({sup 31}P-MRS) linked to altered metabolism of membrane phospholipids and decreased N-acetylaspartate (NAA) or NAA/choline ratio ({sup 1}H-MRS) linked to neuronal damage in frontal (DLPFC) or temporal regions in patients with schizophrenia. These results contribute to the disturbed frontotemporal-thalamic network assumed in schizophrenia and are supported by additional functional neuroimaging, MRI morphometry, and neuropsychological evaluation. The combination of the described investigative techniques with MRS in follow-up studies may provide more specific clues for understanding the pathogenesis and disease course in schizophrenia. (orig.) [German] Die Magnetresonanzspektroskopie (MRS) stellt ein nichtinvasives Verfahren dar, mit dem in vivo biochemische Veraenderungen spezifischer Hirnregionen bei verschiedenen psychiatrischen Erkrankungen untersucht werden koennen. Dabei werden insbesondere die Protonenmagnetresonanzspektroskopie ({sup 1}H-MRS) sowie die Phosphormagnetresonanzspektroskopie ({sup 31}P-MRS) verwendet. In der vorliegenden Uebersichtsarbeit werden die methodischen Grundlagen erlaeutert sowie die Befundlage bei der Schizophrenie referiert. Fuer die Darstellung der Studien zur {sup 1}H-MRS bei schizophrenen Patienten im Vergleich zu einer Kontrollgruppe

  10. Noninvasive assessment of isocitrate dehydrogenase mutation status in cerebral gliomas by magnetic resonance spectroscopy in a clinical setting

    DEFF Research Database (Denmark)

    Tietze, Anna; Choi, Changho; Mickey, Bruce

    2018-01-01

    OBJECTIVE Mutations in the isocitrate dehydrogenase (IDH) genes are of proven diagnostic and prognostic significance for cerebral gliomas. The objective of this study was to evaluate the clinical feasibility of using a recently described method for determining IDH mutation status by using magnetic...... resonance spectroscopy (MRS) to detect the presence of 2-hydroxyglutarate (2HG), the metabolic product of the mutant IDH enzyme. METHODS By extending imaging time by 6 minutes, the authors were able to include a point-resolved spectroscopy (PRESS) MRS sequence in their routine glioma imaging protocol. In 30...... to detect the presence of IDH mutations in the glioma tissue resected. RESULTS In vivo MRS for 2HG correctly identified the IDH mutational status in 88.6% of patients. The sensitivity and specificity was 89.5% and 81.3%, respectively, when using 2 mM 2HG as threshold to discriminate IDH-mutated from...

  11. Highly specific determination of IDH status using edited in vivo magnetic resonance spectroscopy.

    Science.gov (United States)

    Branzoli, Francesca; Di Stefano, Anna Luisa; Capelle, Laurent; Ottolenghi, Chris; Valabrègue, Romain; Deelchand, Dinesh K; Bielle, Franck; Villa, Chiara; Baussart, Bertrand; Lehéricy, Stéphane; Sanson, Marc; Marjanska, Malgorzata

    2017-11-06

    Mutations in the isocitrate dehydrogenase (IDH) enzyme affects 40% of gliomas and represent a major diagnostic and prognostic marker. The goals of this study were to evaluate the performance of noninvasive magnetic resonance spectroscopy (MRS) methods to determine the IDH status of patients with brain gliomas through detection of the oncometabolite 2-hydroxyglutarate (2HG), and to compare performance of these methods with DNA sequencing and tissue 2HG analysis. Twenty-four subjects with suspected diagnosis of low grade glioma were included prospectively in the study. For all subjects, MRS data were acquired at 3 T using two MRS methods, edited MRS using MEGA-PRESS sequence and a PRESS sequence optimized for 2HG detection, using a volume of interest larger than 6 mL. IDH mutational status was determined by combination of automated immunohistochemical analysis (IHC) and Sanger sequencing. 2HG levels in tissue samples measured by gas chromatography-mass spectrometry (GC-MS) were compared to those estimated by MRS. Edited MRS provided 100% specificity and 100% sensitivity in the detection of 2HG. The 2HG levels estimated by this technique were in line with those derived from tissue samples. Optimized PRESS provided lower performance, in agreement with previous findings. Our results suggest that edited MRS is one of the most reliable tools to predict IDH mutation noninvasively, showing high sensitivity and specificity for 2HG detection. Integrating edited MRS in clinical practice may be highly beneficial for noninvasive diagnosis of glioma, prognostic assessment, and treatment planning.

  12. Effects of cardiovascular lifestyle change on lipoprotein subclass profiles defined by nuclear magnetic resonance spectroscopy.

    Science.gov (United States)

    Decewicz, David J; Neatrour, David M; Burke, Amy; Haberkorn, Mary Jane; Patney, Heather L; Vernalis, Marina N; Ellsworth, Darrell L

    2009-06-29

    Low-density lipoprotein (LDL) cholesterol lowering is a primary goal in clinical management of patients with cardiovascular disease, but traditional cholesterol levels may not accurately reflect the true atherogenicity of plasma lipid profiles. The size and concentration of lipoprotein particles, which transport cholesterol and triglycerides, may provide additional information for accurately assessing cardiovascular risk. This study evaluated changes in plasma lipoprotein profiles determined by nuclear magnetic resonance (NMR) spectroscopy in patients participating in a prospective, nonrandomized lifestyle modification program designed to reverse or stabilize progression of coronary artery disease (CAD) to improve our understanding of lipoprotein management in cardiac patients. The lifestyle intervention was effective in producing significant changes in lipoprotein subclasses that contribute to CAD risk. There was a clear beneficial effect on the total number of LDL particles (-8.3%, p lifestyle change program were not confounded by lipid-lowering medications. In at risk patients motivated to participate, an intensive lifestyle change program can effectively alter traditional CAD risk factors and plasma lipoprotein subclasses and may reduce risk for cardiovascular events. Improvements in lipoprotein subclasses are more evident in men compared to women.

  13. Effects of cardiovascular lifestyle change on lipoprotein subclass profiles defined by nuclear magnetic resonance spectroscopy

    Directory of Open Access Journals (Sweden)

    Patney Heather L

    2009-06-01

    Full Text Available Abstract Background Low-density lipoprotein (LDL cholesterol lowering is a primary goal in clinical management of patients with cardiovascular disease, but traditional cholesterol levels may not accurately reflect the true atherogenicity of plasma lipid profiles. The size and concentration of lipoprotein particles, which transport cholesterol and triglycerides, may provide additional information for accurately assessing cardiovascular risk. This study evaluated changes in plasma lipoprotein profiles determined by nuclear magnetic resonance (NMR spectroscopy in patients participating in a prospective, nonrandomized lifestyle modification program designed to reverse or stabilize progression of coronary artery disease (CAD to improve our understanding of lipoprotein management in cardiac patients. Results The lifestyle intervention was effective in producing significant changes in lipoprotein subclasses that contribute to CAD risk. There was a clear beneficial effect on the total number of LDL particles (-8.3%, p Conclusion In at risk patients motivated to participate, an intensive lifestyle change program can effectively alter traditional CAD risk factors and plasma lipoprotein subclasses and may reduce risk for cardiovascular events. Improvements in lipoprotein subclasses are more evident in men compared to women.

  14. Anterior insula GABA levels correlate with emotional aspects of empathy: a proton magnetic resonance spectroscopy study.

    Directory of Open Access Journals (Sweden)

    Qianfeng Wang

    Full Text Available Empathy is a multidimensional construct referring to the capacity to understand and share the emotional and affective states of another person. Cerebral γ-aminobutyric acid (GABA-ergic levels are associated with a variety of neurological and psychiatric disorders. However, the role of the GABA system in different dimensions of empathy has not been investigated.Thirty-two right-handed healthy volunteers took part in this study. We used proton magnetic resonance spectroscopy to determine GABA concentrations in the anterior insula (AI and the anterior cingulate cortex (ACC and to examine the relationship between the GABA concentrations and the subcomponents of empathy evaluated by the Interpersonal Reactivity Index (IRI.Pearson correlation analyses (two-tailed showed that AI GABA was significantly associated with the empathy concern score (r = 0.584, p<0.05 and the personal distress score (r = 0.538, p<0.05 but not significantly associated with other empathy subscales. No significant correlation was found between ACC GABA and empathy subscores.Left AI GABA was positively correlated with the emotional aspects of empathy. These preliminary findings call into question whether AI GABA alterations might predict empathy dysfunction in major psychiatric disorders such as autism and schizophrenia, which have been described as deficits in emotional empathic abilities.

  15. Metabolic profile of dystrophic mdx mouse muscles analyzed with in vitro magnetic resonance spectroscopy (MRS).

    Science.gov (United States)

    Martins-Bach, Aurea B; Bloise, Antonio C; Vainzof, Mariz; Rahnamaye Rabbani, Said

    2012-10-01

    Duchenne muscular dystrophy (DMD) is a recessive X-linked form of muscular dystrophy characterized by progressive and irreversible degeneration of the muscles. The mdx mouse is the classical animal model for DMD, showing similar molecular and protein defects. The mdx mouse, however, does not show significant muscle weakness, and the diaphragm muscle is significantly more degenerated than skeletal muscles. In this work, (1)H magnetic resonance spectroscopy (MRS) was used to study the metabolic profile of quadriceps and diaphragm muscles from mdx and control mice. Using principal components analysis (PCA), the animals were separated into groups according to age and lineages. The classification was compared to histopathological analysis. Among the 24 metabolites identified from the nuclear MR spectra, only 19 were used by the PCA program for classification purposes. These can be important key biomarkers associated with the progression of degeneration in mdx muscles and with natural aging in control mice. Glutamate, glutamine, succinate, isoleucine, acetate, alanine and glycerol were increased in mdx samples as compared to control mice, in contrast to carnosine, taurine, glycine, methionine and creatine that were decreased. These results suggest that MRS associated with pattern recognition analysis can be a reliable tool to assess the degree of pathological and metabolic alterations in the dystrophic tissue, thereby affording the possibility of evaluation of beneficial effects of putative therapies. Copyright © 2012 Elsevier Inc. All rights reserved.

  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. ROLE OF MAGNETIC RESONANCE SPECTROSCOPY IN INTRACRANIAL LESIONS- A STUDY OF 75 CASES

    Directory of Open Access Journals (Sweden)

    Rajendra N. Solank

    2017-10-01

    Full Text Available BACKGROUND Our study have shown the role of MR spectroscopy in lesions whenever results are equivocal or non-conclusive even on MRI. MR spectroscopy can differentiate the lesions, particularly intracranial lesions on the basis of various metabolites. The aims of this study is to diagnose the intracranial lesions and to show the advantage of MR spectroscopy over the conventional MRI, to differentiate the neoplastic from non-neoplastic lesion, to prove the reliability of MR spectroscopy in identifying the different grades of glioma with histopathological correlation as well as to differentiate recurrent tumour from post-operative changes or radiation necrosis. MATERIALS AND METHODS During the period of August 2009 to July 2011, a prospective study of 75 patients was carried out at Department of Radiodiagnosis, Civil Hospital and BJ Medical College, Ahmedabad, Gujarat. MRI was performed on 1.5 Tesla MR scanner (GE HDXT using dedicated head coil. Conventional MR imaging was performed followed by MR spectroscopy using point resolved spectroscopy. After deciding the region of interest voxel was kept and 2D multivoxel proton spectroscopy (TR- 1000 msec, TE- 144 msec, voxel size 20 x 20 mm or single voxel proton spectroscopy (TR- 1500 msec, TE- 35 msec, voxel size 20 x 20 mm was performed and spectra obtained. RESULTS In the present study of 75 patients, the maximum number of patients were between 31 to 50 years of age. The approximate ratio of male: female was 2: 1. In our study sensitivity, specificity, positive predictive value, negative predictive value of MRI are 89%, 87%, 87% and 89% respectively and of MRI + MRS are 100%, 97%, 97% and 100% respectively in tumours. CONCLUSION MRS (Magnetic Resonance Spectroscopy is a non-invasive imaging technique that studies the chemical activity in the brain and detects the presence of certain chemical substances. Through this imaging technique, images and graphs of the brain can be obtained.

  18. Minipig Model of Huntington's Disease: H-1 Magnetic Resonance Spectroscopy of the Brain

    Czech Academy of Sciences Publication Activity Database

    Jozefovičová, M.; Herynek, V.; Jírů, F.; Dezortová, M.; Juhásová, Jana; Juhás, Štefan; Motlík, Jan; Hájek, M.

    2016-01-01

    Roč. 65, č. 1 (2016), s. 155-163 ISSN 0862-8408 R&D Projects: GA TA ČR(CZ) TA01011466; GA MŠk(CZ) 7F14308; GA MŠk ED2.1.00/03.0124 Institutional support: RVO:67985904 Keywords : Huntington´s disease * minipigs * magnetic resonance spectroscopy Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 1.461, year: 2016

  19. Real-time assessment of Krebs cycle metabolism using hyperpolarized 13C magnetic resonance spectroscopy

    OpenAIRE

    Schroeder, Marie A.; Atherton, Helen J; Ball, Daniel R; Cole, Mark A; Heather, Lisa C; Griffin, Julian L.; Clarke, Kieran; Radda, George K.; Tyler, Damian J

    2009-01-01

    The Krebs cycle plays a fundamental role in cardiac energy production and is often implicated in the energetic imbalance characteristic of heart disease. In this study, we measured Krebs cycle flux in real time in perfused rat hearts using hyperpolarized magnetic resonance spectroscopy (MRS). [2-13C]Pyruvate was hyperpolarized and infused into isolated perfused hearts in both healthy and postischemic metabolic states. We followed the enzymatic conversion of pyruvate to lactate, acetylcarnitin...

  20. Optimization of metabolite detection by quantum mechanics simulations in magnetic resonance spectroscopy

    OpenAIRE

    Gambarota, Giulio

    2016-01-01

    International audience; Magnetic resonance spectroscopy (MRS) is a well established modality for investigating tissue metabolism in vivo. In recent years, many efforts by the scientific community have been directed towards the improvement of metabolite detection and quantitation.Quantum mechanics simulations allow for investigations of the MR signal behaviour of metabolites; thus, they provide an essential tool in the optimization of metabolite detection.In this review, we will examine quantu...

  1. In vivo 1H-magnetic resonance spectroscopy study of the attentional networks in autism

    OpenAIRE

    Bernardi, Silvia; Anagnostou, Evdokia; Shen, Jun; Kolevzon, Alexander; Buxbaum, Joseph D.; Hollander, Eric; Hof, Patrick R.; Fan, Jin

    2010-01-01

    Attentional dysfunction is one of the most consistent findings in individuals with autism spectrum disorders (ASD). However, the significance of such findings for the pathophysiology of autism is unclear. In this study, we investigated cellular neurochemistry with proton magnetic resonance spectroscopy imaging (1H-MRS) in brain regions associated with networks subserving alerting, orienting, and executive control of attention in patients with ASD. Concentrations of cerebral N-acetyl-aspartate...

  2. Optimally designed narrowband guided-mode resonance reflectance filters for mid-infrared spectroscopy

    OpenAIRE

    Liu, Jui-Nung; Schulmerich, Matthew V.; Bhargava, Rohit; Cunningham, Brian T.

    2011-01-01

    An alternative to the well-established Fourier transform infrared (FT-IR) spectrometry, termed discrete frequency infrared (DFIR) spectrometry, has recently been proposed. This approach uses narrowband mid-infrared reflectance filters based on guided-mode resonance (GMR) in waveguide gratings, but filters designed and fabricated have not attained the spectral selectivity (≤ 32 cm−1) commonly employed for measurements of condensed matter using FT-IR spectroscopy. With the incorporation of disp...

  3. Determination of elastic modulus for hollow spherical shells via resonant ultrasound spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Ma, Xiaojun [Institute of Modern Physics, Fudan University, Shanghai 200433 (China); Research Center of Laser Fusion, CAEP, Mianyang 621900 (China); Tang, Xing; Wang, Zongwei [Research Center of Laser Fusion, CAEP, Mianyang 621900 (China); Chen, Qian; Qian, Menglu [Institute of Acoustic, Tongji University, Shanghai 200092 (China); Meng, Jie [Research Center of Laser Fusion, CAEP, Mianyang 621900 (China); Tang, Yongjian [Institute of Modern Physics, Fudan University, Shanghai 200433 (China); Research Center of Laser Fusion, CAEP, Mianyang 621900 (China); Shen, Hao [Institute of Modern Physics, Fudan University, Shanghai 200433 (China); Gao, Dangzhong, E-mail: dgaocn@163.com [Research Center of Laser Fusion, CAEP, Mianyang 621900 (China)

    2017-04-15

    Highlights: • The axisymmetric frequency equation of an isotropic hollow two-layer sphere is deduced by three dimension elasticity theory and global matrix method. • The simulated results demonstrate that the natural frequencies of a hollow sphere are more strongly dependent on Young’s modulus than Poisson's ratio. • The Young’s moduli of polymer capsules with an sub-millimeter inner radius are measured accurately with an uncertainty of ∼10%. - Abstract: The elastic property of a capsule is one of the essential parameters both in engineering applications and scientific understanding of material nature in inertial confinement fusion (ICF) experiments. The axisymmetric frequency equation of an isotropic hollow two-layer sphere is deduced by three dimension elasticity theory and global matrix method, and a combined resonant ultrasound spectroscopy(RUS), which consists of a piezoelectric-based resonant ultrasound spectroscopy(PZT-RUS) and a laser-based resonant ultrasound spectroscopy(LRUS), is developed for determining the elastic modulus of capsule. To understand the behavior of natural frequencies varying with elastic properties, the dependence of natural frequencies on Young’s modulus and Poisson’s ratio are calculated numerically. Some representative polymer capsules are measured using PZT-RUS and LRUS. Based on the theoretical and experimental results, the Young’s moduli of these capsules are measured accurately with an uncertainty of ∼10%.

  4. Phosphorous31 magnetic resonance spectroscopy after total sleep deprivation in healthy adult men.

    Science.gov (United States)

    Dorsey, Cynthia M; Lukas, Scott E; Moore, Constance M; Tartarini, Wendy L; Parow, Aimee M; Villafuerte, Rosemond A; Renshaw, Perry F

    2003-08-01

    To investigate chemical changes in the brains of healthy adults after sleep deprivation and recovery sleep, using phosphorous magnetic resonance spectroscopy. Three consecutive nights (baseline, sleep deprivation, recovery) were spent in the laboratory. Objective sleep measures were assessed on the baseline and recovery nights using polysomnography. Phosphorous magnetic resonance spectroscopy scans took place beginning at 7 am to 8 am on the morning after each of the 3 nights. Sleep laboratory in a private psychiatric teaching hospital. Eleven healthy young men. Following a baseline night of sleep, subjects underwent a night of total sleep deprivation, which involved supervision to ensure the absence of sleep but was not polysomnographically monitored. No significant changes in any measure of brain chemistry were observed the morning after a night of total sleep deprivation. However, after the recovery night, significant increases in total and beta-nucleoside triphosphate and decreases in phospholipid catabolism, measured by an increase in the concentration of glycerylphosphorylcholine, were observed. Chemical changes paralleled some changes in objective sleep measures. Significant chemical changes in the brain were observed following recovery sleep after 1 night of total sleep deprivation. The specific process underlying these changes is unclear due to the large brain region sampled in this exploratory study, but changes may reflect sleep inertia or some aspect of the homeostatic sleep mechanism that underlies the depletion and restoration of sleep. Phosphorous magnetic resonance spectroscopy is a technique that may be of value in further exploration of such sleep-wake functions.

  5. Segmentation of brain tumor images using in vivo spectroscopy, relaxometry and diffusometry by magnetic resonance

    Energy Technology Data Exchange (ETDEWEB)

    Martin L, M. [Universidad Central de Venezuela, A.P. 47586, Caracas 1041-A (Venezuela)

    2006-07-01

    A new methodology is developed for the segmentation of brain tumor images using information obtained by different magnetic resonance techniques such as in vivo spectroscopy, relaxometry and diffusometry. In vivo spectroscopy is used as a sort of virtual biopsy to characterize the different tissue types present in the lesion (active tumor, necrotic tissue or edema and normal or non-affected tissue). Due to the fact that in vivo spectroscopy information lacks the spatial resolution for treatment considerations, this information has to be combined or fused with images obtained by relaxometry and diffusometry with excellent spatial resolution. Some segmentation schemes are presented and discussed, using the high spatial resolution techniques individually or combined. The results show that segmentation done in this way is highly reliable for the application of future therapies such as radiosurgery or radiotherapy. (Author)

  6. Far off-resonance laser frequency stabilization using multipass cells in Faraday rotation spectroscopy.

    Science.gov (United States)

    Quan, Wei; Li, Yang; Li, Rujie; Shang, Huining; Fang, Zishan; Qin, Jie; Wan, Shuangai

    2016-04-01

    We propose a far off-resonance laser frequency stabilization method by using multipass cells in Rb Faraday rotation spectroscopy. Based on the detuning equation, if multipass cells with several meters optical path length are used in the conventional Faraday spectroscopy, the detuning of the lock point can be extended much further from the alkali metal resonance. A plate beam splitter was used to generate two different Faraday signals at the same time. The transmitted optical path length was L=50  mm and the reflected optical path length was 2L=100  mm. When the optical path length doubled, the detuning of the lock points moved further away from the atomic resonance. The temperature dependence of the detuning of the lock point was also analyzed. A temperature-insensitive lock point was found near resonance when the cell temperature was between 110°C and 130°C. We achieved an rms fluctuation of 0.9 MHz/23 h at a detuning of 0.5 GHz. A frequency drift of 16 MHz/h at a detuning of -5.6  GHz and 4 MHz/h at a detuning of -5.2  GHz were also obtained for the transmitted and reflected light Faraday signal.

  7. Effect of gadoxetic acid on quantification of hepatic steatosis using magnetic resonance spectroscopy: A prospective study

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Ju Won; Kim, Sung Mo; Heo, Sook Hee; Kim, Jin Woong; Jeong, Yong Yeon; Kang, Heoung Keun [Dept. of Radiology, Chonnam National University Hwasun Hospital, Hwasun (Korea, Republic of); Jeong, Gwang Woo; Shin, Sang Soo [Dept. of Radiology, Chonnam National University Hospital, Gwangju (Korea, Republic of)

    2017-04-15

    We prospectively evaluated whether gadoxetic acid (Gd-EOB-DTPA) administration for liver magnetic resonance (MR) imaging affects the quantification of hepatic steatosis using MR spectroscopy (MRS). A total of 155 patients were included, who underwent gadoxetic acid-enhanced liver MR imaging and MRS during a 5-month period. Fast breath-hold high-speed T2-corrected multi-echo MRS was used before, and 20 min after, gadoxetic acid injection. The same location was maintained in the pre-contrast and post-contrast MRS. Changes in the fat fraction (FF) were compared between the pre- and post-contrast MRS using a paired t-test. The change in FF between cirrhotic and non-cirrhotic patients was compared using an independent t-test. In cirrhotic patients, the correlation between FF change and biochemical marker using Pearson's correlation test, was evaluated. The mean FF in the post-contrast MRS (5.05 ± 5.26%) was significantly higher than in the pre-contrast MRS (4.77 ± 0.57%) (p < 0.000). The FF change between pre-contrast and post-contrast MRS was significantly higher in non-cirrhotic patients (0.41 ± 0.77%) than in cirrhotic patients (0.14 ± 0.59) (p = 0.010). Albumin and alkaline phosphatase shows weak correlation with FF change (both p < 0.02). Gadoxetic acid affects the quantification of hepatic steatosis by MRS. Hence, MRS should be performed before gadoxetic acid injection, particularly in non-cirrhotic patients.

  8. Preliminary observations and clinical value of N-acetyl resonances in ovarian tumours using in-vivo proton MR spectroscopy at 3T

    Energy Technology Data Exchange (ETDEWEB)

    Takeuchi, Mayumi; Matsuzaki, Kenji; Harada, Masafumi [University of Tokushima, Department of Radiology, Tokushima (Japan)

    2011-12-15

    To retrospectively evaluate the clinical significance of N-acetyl resonances at 2 ppm in in-vivo proton magnetic resonance (MR) spectroscopy for distinguishing mucinous and non-mucinous tumours in patients with ovarian masses. MR spectroscopy was performed in patients with pathologically diagnosed ovarian tumours at 3T-MR imaging. Single-voxel MR spectroscopy data were collected from a single square volume of interest that encompassed the ovarian masses. The metabolite resonance peak areas at 2 ppm were quantified relative to unsuppressed water using a software package (LCModel). A total of 32 ovarian lesions in 32 patients were evaluated in this study. High metabolite peak at 2 ppm was observed in all nine mucinous tumours (9.71 +/- 7.46 mM), whereas low peak was observed in 14 of 23 non-mucinous tumours (3.12 +/- 1.42 mM) (p < 0.001). Using a cut off value of 4.45 mM for mucinous tumours had a sensitivity of 89%, specificity of 86%, PPV of 80%, and NPV of 92%. Proton MR spectroscopy with quantitative evaluation of the metabolite at 2 ppm concentration, which may suggest the presence of mucinous material containing N-acetyl mucinous compounds, can provide helpful information in distinguishing mucinous and non-mucinous ovarian tumours. (orig.)

  9. Localized one-dimensional single voxel magnetic resonance spectroscopy without J coupling modulations.

    Science.gov (United States)

    Lin, Yanqin; Lin, Liangjie; Wei, Zhiliang; Zhong, Jianhui; Chen, Zhong

    2016-12-01

    To acquire single voxel localized one-dimensional 1 H magnetic resonance spectroscopy (MRS) without J coupling modulations, free from amplitude and phase distortions. A pulse sequence, named PRESSIR, is developed for volume localized MRS without J modulations at arbitrary echo time (TE). The J coupling evolution is suppressed by the J-refocused module that uses a 90° pulse at the midpoint of a double spin echo. The localization performance of the PRESSIR sequence was tested with a two-compartment phantom. The proposed sequence shows similar voxel localization accuracy as PRESS. Both PRESSIR and PRESS sequences were performed on MRS brain phantom and pig brain tissue. PRESS spectra suffer from amplitude and phase distortions due to J modulations, especially under moderate and long TEs, while PRESSIR spectra are almost free from distortions. The PRESSIR sequence proposed herein enables the acquisition of single voxel in-phase MRS within a single scan. It allows an enhanced signal intensity of J coupling metabolites and reducing undesired broad resonances with short T2s while suppressing J modulations. Moreover, it provides an approach for direct measurement of nonoverlapping J coupling peaks and of transverse relaxation times T2s. Magn Reson Med 76:1661-1667, 2016. © 2015 International Society for Magnetic Resonance in Medicine. © 2015 International Society for Magnetic Resonance in Medicine.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2001-03-01

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

  11. [Possibilities in the differential diagnosis of brain neoplasms using the long and short time sequences of proton magnetic resonance spectroscopy

    NARCIS (Netherlands)

    Gajewicz, W.; Goraj, B.M.

    2004-01-01

    Currently to perform proton magnetic resonance spectroscopy (1H MRS) with single voxel spectroscopy (SVS) technique long and/or short echo time sequences are used in order to provide complementary information. PURPOSE: The aim of the study was to compare the usefulness of STEAM (time echo, TE, 20

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

    DEFF Research Database (Denmark)

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

    1988-01-01

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

  13. Progress in Resonance Enhanced Multiphoton Ionization Spectroscopy of Transient Free Radicals

    Science.gov (United States)

    Hudgens, Jeffrey W.

    The following sections are included: * IntroductioN * An Overview of Rehpi Spectroscopy * A Brief History * The Rempi Mechanism * Multiphoton Selection Rules * Characteristics of Rydberg States * Experimental Elements * Apparatus * Identification of Spectral Carriers * The Unique Role of Mass Spectrometry * REMPI Mass Spectra of Free Radicals Show Little Fragmentation * Determination of the Photon Order of the Resonant State * Summary of Transient Radicals Studied By Rempi Spectroscopy * Diatomic Radicals * CF Radical * CH Radical * REMPI Spectra of ClO and BrO Radicals * ClO * BrO * CCl Radical * NH (a1 Δ) Radical * PH (b 1Σ+) Radical * PO Radical * SiF Radical * Triatomic Radicals * CCO Radical * NH2 Radical * HCO Radical * SiF2 Radical * Methyl Radical * One Photon Resonance Enhanced Ionization * Three Photon REMPI of Methyl radicals * Two Photon Spectroscopy * The np ^{2}A^{primeprime}_{2}l←l← tildeX ^{2}A^{primeprime}_{2} Bands * The nf ^{2}E^{prime} l← l← tildeX ^{2}A^{primeprime}_{2} Bands * Substituted Methyl Radicals * CH2F Radical * CHCl2 Radical * CH2OH Radical * CF3 Radical * Other Polyatomic Radicals * Allyl and 2-Methvlallyl Radicals * Substituted Allyl Radicals * Benzyl Radical * Cyclohexanyl radicals * Ethyl Radical * Methoxy Radical * Acknowledgments * References

  14. Investigation of radiosterilization of Benzydamine Hydrochloride by electron spin resonance spectroscopy

    Science.gov (United States)

    Çolak, Şeyda

    2016-10-01

    The use of ionizing radiation for sterilization of pharmaceuticals is an attractive and growing technology. In the present work, the spectroscopic and kinetic features of the radicals induced in gamma irradiated solid Benzydamine Hydrochloride (BH) sample is investigated in the dose range of 3-34 kGy at different temperatures using Electron Spin Resonance (ESR) spectroscopy. Gamma irradiated BH indicated eight resonance peaks centered at g=2.0029 originating from two different radical species. Decay activation energy of the radical mostly responsible from central intense resonance line was calculated to be 25.6±1.5 kJ/mol by using the signal intensity decay data derived from annealing studies performed at high temperatures. A linear function of the applied dose was found to describe best the experimental dose-response data. However, the discrimination of irradiated BH from unirradiated one was possible even 3 months after storage at normal conditions. Basing on these findings it was concluded that BH and BH containing drugs could be safely sterilized by gamma radiation and that ESR spectroscopy could be successfully used as a potential technique for monitoring their radiosterilizations.

  15. Elucidation of reactive wavepackets by two-dimensional resonance Raman spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Guo, Zhenkun; Molesky, Brian P.; Cheshire, Thomas P.; Moran, Andrew M., E-mail: ammoran@email.unc.edu [Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599 (United States)

    2015-09-28

    Traditional second-order kinetic theories fail to describe sub-picosecond photochemical reactions when solvation and vibrational dephasing undermine the assumption of equilibrium initial conditions. Four-wave mixing spectroscopies may reveal insights into such non-equilibrium processes but are limited by the single “population time” available in these types of experiments. Here, we use two-dimensional resonance Raman (2DRR) spectroscopy to expose correlations between coherent nuclear motions of the reactant and product in the photodissociation reaction of triiodide. It is shown that the transition of a nuclear wavepacket from the reactant (triiodide) to product (diiodide) states gives rise to a unique pattern of 2DRR resonances. Peaks associated with this coherent reaction mechanism are readily assigned, because they are isolated in particular quadrants of the 2DRR spectrum. A theoretical model in which the chemical reaction is treated as a vibronic coherence transfer transition from triiodide to diiodide reproduces the patterns of 2DRR resonances detected in experiments. These signal components reveal correlation between the nonequilibrium geometry of triiodide and the vibrational coherence frequency of diiodide. The 2DRR signatures of coherent reaction mechanisms established in this work may generalize to studies of ultrafast energy and charge transfer processes.

  16. Resonance-Enhanced Raman Spectroscopy on Explosives Vapor at Standoff Distances

    Directory of Open Access Journals (Sweden)

    Anneli Ehlerding

    2012-01-01

    Full Text Available Resonance-enhanced Raman spectroscopy has been used to perform standoff measurements on nitromethane (NM, 2,4-DNT, and 2,4,6-TNT in vapor phase. The Raman cross sections for NM, DNT, and TNT in vapor phase have been measured in the wavelength range 210–300 nm under laboratory conditions, in order to estimate how large resonance enhancement factors can be achieved for these explosives. The results show that the signal is enhanced up to 250,000 times for 2,4-DNT and up to 60,000 times for 2,4,6-TNT compared to the nonresonant signal at 532 nm. Realistic outdoor measurements on NM in vapor phase at 13 m distance were also performed, which indicate a potential for resonance Raman spectroscopy as a standoff technique for detection of vapor phase explosives. In addition, the Raman spectra of acetone, ethanol, and methanol were measured at the same wavelengths, and their influence on the spectrum from NM was investigated.

  17. Measurement of free radicals using electron paramagnetic resonance spectroscopy during open aorto-iliac arterial reconstruction.

    Science.gov (United States)

    Majewski, Wacław; Krzyminiewski, Ryszard; Stanisić, Michał; Iskra, Maria; Krasiński, Zbigniew; Nowak, Marek; Dobosz, Bernadeta

    2014-11-27

    Aortic cross-clamping during abdominal aortic aneurysm (AAA) open repair leads to development of ischemia-reperfusion injury. Electron paramagnetic resonance spectroscopy (EPR) spin-trapping is a valuable method of direct measurement of free radicals. The objective of the study was to evaluate the results of EPR as a direct method of free radical measurement and degree of inflammatory response in open operative treatment of patients with AAA and aorto-iliac occlusive disease (AIOD). The study was performed on a group of 32 patients with AAA and 25 patients with AIOD scheduled for open repair. Peripheral venous blood for EPR spectroscopy and for SOD, GPx, ox-LDL, Il-6, TNF-alfa, CRP, and HO-1 were harvested. Selected parameters were established accordingly to specified EPR and immunohistochemical methods and analyzed between groups by Mann-Whitney U test and Wilcoxon matched-pairs signed-ranks test with Bonferroni correction. Free radicals level was correlated with the time of the aortic cross-clamping after the reperfusion of he first and second leg in AAA (r=0.7; r=0.47). ox-LDL in AAA decreased 5 min after reperfusion of the first leg (32.99 U/L, range: 14.09-77.12) and 5 min after reperfusion of the second leg (26.75 U/L, range: 11.56-82.12) and 24 h after the operation (25.85 U/L, range: 14.29-49.70). HO-1 concentration increased to above the level before intervention 24 h after surgery. The activities of GPx and SOD decreased 5 min after the first-leg reperfusion in AAA. Twenty-four hours after surgery, inflammatory markers increased in AAA to CRP was 14.76 ml/l (0.23-38.55), IL-6 was 141.22 pg/ml (84.3-591.03), TNF-alfa was 6.82 pg/ml (1.76-80.01) and AIOD: CRP was 18.44 mg/l (2.56-33.14), IL-6: 184.1 pg/ml (128.46-448.03), TNF-alfa was 7.74 pg/ml (1.74-74.74). EPR spin-trapping demonstrates temporarily elevated level of free radicals in early phase of reperfusion, leading to decrease antioxidants in AAA. Elevated free radical levels decreased 24 h after

  18. Thalamic metabolic abnormalities in patients with Huntington's disease measured by magnetic resonance spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Casseb, R.F.; Castellano, G., E-mail: gabriela@ifi.unicamp.br [Cooperacao Interinstitucional de Apoio a Pesquisas sobre o Cerebro (Programa CInAPCe), Sao Paulo, SP (Brazil); Universidade Estadual de Campinas (UNICAMP), SP (Brazil). Instituto de Fisica Gleb Wataghin. Dept. de Raios Cosmicos e Cronologia; D' Abreu, A.; Cendes, F. [Universidade Estadual de Campinas (UNICAMP), SP (Brazil). Dept. de Neurologia. Lab. de Neuroimagem; Cooperacao Interinstitucional de Apoio a Pesquisas sobre o Cerebro (Programa CInAPCe), Sao Paulo, SP (Brazil); Ruocco, H.H. [Universidade Estadual de Campinas (UNICAMP), SP (Brazil). Fac. de Ciencias Medicas. Dept. de Neurologia. Lab. de Neuroimagem; Lopes-Cendes, I., E-mail: seixas.fk@gmail.com [Universidade Estadual de Campinas (UNICAMP), SP (Brazil). Fac. de Ciencias Medicas. Dept. de Genetica Medica; Cooperacao Interinstitucional de Apoio a Pesquisas sobre o Cerebro (Programa CInAPCe), Sao Paulo, SP (Brazil)

    2013-08-15

    Huntington's disease (HD) is a neurologic disorder that is not completely understood; its fundamental physiological mechanisms and chemical effects remain somewhat unclear. Among these uncertainties, we can highlight information about the concentrations of brain metabolites, which have been widely discussed. Concentration differences in affected, compared to healthy, individuals could lead to the development of useful tools for evaluating the progression of disease, or to the advance of investigations of different/alternative treatments. The aim of this study was to compare the thalamic concentration of metabolites in HD patients and healthy individuals using magnetic resonance spectroscopy. We used a 2.0-Tesla magnetic field, repetition time of 1500 ms, and echo time of 135 ms. Spectra from 40 adult HD patients and 26 control subjects were compared. Quantitative analysis was performed using the LCModel method. There were statistically significant differences between HD patients and controls in the concentrations of N-acetylaspartate+N-acetylaspartylglutamate (NAA+NAAG; t-test, P,0.001), and glycerophosphocholine+phosphocholine (GPC+PCh; t-test, P=0.001) relative to creatine+phosphocreatine (Cr+PCr). The NAA+NAAG/Cr+PCr ratio was decreased by 9% and GPC+PCh/Cr+PCr increased by 17% in patients compared with controls. There were no correlations between the concentration ratios and clinical features. Although these results could be caused by T1 and T2 changes, rather than variations in metabolite concentrations given the short repetition time and long echo time values used, our findings point to thalamic dysfunction, corroborating prior evidence. (author)

  19. Proton magnetic resonance spectroscopy in patients with early stages of amyotrophic lateral sclerosis

    Energy Technology Data Exchange (ETDEWEB)

    Sivak, Stefan [Comenius University, Clinic of Neurology, Jessenius Faculty of Medicine, Martin (Slovakia); Jessenius Medical Faculty, Clinic of Neurology, Martin (Slovakia); Bittsansky, Michal; Dobrota, Dusan [Comenius University, Department of Medical Biochemistry, Jessenius Faculty of Medicine, Martin (Slovakia); Kurca, Egon; Turcanova-Koprusakova, Monika; Grofik, Milan; Nosal, Vladimir [Comenius University, Clinic of Neurology, Jessenius Faculty of Medicine, Martin (Slovakia); Polacek, Hubert [Comenius University, Clinic of Radiodiagnostics, Jessenius Faculty of Medicine, Martin (Slovakia)

    2010-12-15

    Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative disorder primarily affecting upper and lower motor neurons. Due to relative fast progression of the disease, early diagnosis is essential. Proton magnetic resonance spectroscopy ({sup 1}H-MRS) is used for objectivization of upper motor neuron (UMN) lesions. The aim of this study was to assess the use of {sup 1}H-MRS in the early stages of ALS. Eleven patients with clinically definite (n = 2), probable (n = 7), and probable laboratory-supported (n = 2) diagnosis of ALS with disease duration of less than 14 months were studied. Control group consists of 11 sex- and age-matched healthy subjects. All subjects underwent assessment of functional disability using revised ALS Functional Rating Scale (ALSFRS-R) and single-voxel {sup 1}H-MRS examination of both precentral gyri, pons, medulla oblongata, and occipital lobe. Spectra were evaluated with LCModel software. The mean disease duration was 6.5 {+-} 3.5 months. The median ALSFRS-R was 42. Significant decrease between patient and control groups was found in the NAA/Cre ratio in the left and right precentral gyri (p = 0.008, p = 0.040). Other metabolite ratios in other areas did not show significant differences. Total ALSFRS-R score weakly positively correlated with NAA/Cre ratio in the left precentral gyrus (p = 0.047). {sup 1}H-MRS is sensitive to detect metabolic changes caused by neurodegeneration processes during ALS and can be used for detection of UMN dysfunction. These MRS changes in the early stages of ALS are most prominent in motor cortex. (orig.)

  20. A proton magnetic resonance spectroscopy study in schizoaffective disorder: comparison of bipolar disorder and schizophrenia.

    Science.gov (United States)

    Kalaycı, Demet; Ozdel, Osman; Sözeri-Varma, Gülfizar; Kıroğlu, Yılmaz; Tümkaya, Selim

    2012-04-27

    The aim of this study was to compare schizoaffective disorder, bipolar disorder and schizophrenia based on (1)H-MRS metabolite values in dorsolateral prefrontal cortex and executive functions. The subjects comprised 15 patients with bipolar disorder type I (BD), 15 with schizophrenia (SCH), 15 with schizoaffective disorder (SAD) and 15 healthy controls. We performed proton magnetic resonance spectroscopy ((1)H-MRS) of the dorsolateral prefrontal cortex (DLPFC) bilaterally. Levels of N-acetyl aspartate (NAA), choline-containing compounds (Cho) and creatine-containing compounds (Cr) were measured in the DLPFC using (1)H-MRS. We administered the Wisconsin Card Sorting Test (WCST) and the Stroop Test (ST) to evaluate executive functions. The SAD, BD and SCH patients had lower levels of NAA than the control group. The SAD and BD patients had low levels of Cho compared to the control group. The left DLPFC Cr levels in all of the patient groups and the right DLPFC Cr levels in the BD and SAD groups were lower than in the control group. The levels of NAA Cho and Cr were not related to executive functions and attention performance. Cr level were related to attention processes, only in SCH. Our results indicate that NAA levels are reduced in schizoaffective disorder, bipolar disorder and schizophrenia, but the reduction in the levels of NAA is not a distinctive feature among these three illnesses. Schizoaffective and bipolar disorders have similar features related to the levels of compounds containing Cho and Cr. This similarity may be related to these illnesses both having an affective basis. Copyright © 2012 Elsevier Inc. All rights reserved.

  1. Metabolic imaging of human kidney triglyceride content: reproducibility of proton magnetic resonance spectroscopy.

    Directory of Open Access Journals (Sweden)

    Sebastiaan Hammer

    Full Text Available OBJECTIVE: To assess the feasibility of renal proton magnetic resonance spectroscopy for quantification of triglyceride content and to compare spectral quality and reproducibility without and with respiratory motion compensation in vivo. MATERIALS AND METHODS: The Institutional Review Board of our institution approved the study protocol, and written informed consent was obtained. After technical optimization, a total of 20 healthy volunteers underwent renal proton magnetic resonance spectroscopy of the renal cortex both without and with respiratory motion compensation and volume tracking. After the first session the subjects were repositioned and the protocol was repeated to assess reproducibility. Spectral quality (linewidth of the water signal and triglyceride content were quantified. Bland-Altman analyses and a test by Pitman were performed. RESULTS: Linewidth changed from 11.5±0.4 Hz to 10.7±0.4 Hz (all data pooled, p<0.05, without and with respiratory motion compensation respectively. Mean % triglyceride content in the first and second session without respiratory motion compensation were respectively 0.58±0.12% and 0.51±0.14% (P = NS. Mean % triglyceride content in the first and second session with respiratory motion compensation were respectively 0.44±0.10% and 0.43±0.10% (P = NS between sessions and P = NS compared to measurements with respiratory motion compensation. Bland-Altman analyses showed narrower limits of agreement and a significant difference in the correlated variances (correlation of -0.59, P<0.05. CONCLUSION: Metabolic imaging of the human kidney using renal proton magnetic resonance spectroscopy is a feasible tool to assess cortical triglyceride content in humans in vivo and the use of respiratory motion compensation significantly improves spectral quality and reproducibility. Therefore, respiratory motion compensation seems a necessity for metabolic imaging of renal triglyceride content in vivo.

  2. THz/Infrared Double Resonance Two-Photon Spectroscopy of HD+ for Determination of Fundamental Constants

    Directory of Open Access Journals (Sweden)

    Florin Lucian Constantin

    2017-10-01

    Full Text Available A double resonance two-photon spectroscopy scheme is discussed to probe jointly rotational and rovibrational transitions of ensembles of trapped HD+ ions. The two-photon transition rates and lightshifts are calculated with the two-photon tensor operator formalism. The rotational lines may be observed with sub-Doppler linewidth at the hertz level and good signal-to-noise ratio, improving the resolution in HD+ spectroscopy beyond the 10−12 level. The experimental accuracy, estimated at the 10−12 level, is comparable with the accuracy of theoretical calculations of HD+ energy levels. An adjustment of selected rotational and rovibrational HD+ lines may add clues to the proton radius puzzle, may provide an independent determination of the Rydberg constant, and may improve the values of proton-to-electron and deuteron-to-proton mass ratios beyond the 10−11 level.

  3. Nuclear resonance vibrational spectroscopy (NRVS) of rubredoxin and MoFe protein crystals

    Energy Technology Data Exchange (ETDEWEB)

    Guo, Yisong [University of California, Department of Applied Science (United States); Brecht, Eric [Montana State University, Department of Chemistry and Biochemistry (United States); Aznavour, Kristen [University of Southern California, Department of Chemistry (United States); Nix, Jay C. [Lawrence Berkeley National Laboratory, Physical Biosciences Division (United States); Xiao, Yuming; Wang, Hongxin [University of California, Department of Applied Science (United States); George, Simon J. [Lawrence Berkeley National Laboratory, Physical Biosciences Division (United States); Bau, Robert [University of Southern California, Department of Chemistry (United States); Keable, Stephen; Peters, John W. [Montana State University, Department of Chemistry and Biochemistry (United States); Adams, Michael W. W. [University of Georgia, Department of Biochemistry and Molecular Biology (United States); Jenney, Francis E. Jr. [Georgia Campus, Philadelphia College of Osteopathic Medicine (United States); Sturhahn, Wolfgang; Alp, Ercan E.; Zhao, Jiyong [Argonne National Laboratory, Advanced Photon Source (United States); Yoda, Yoshitaka [JASRI (Japan); Cramer, Stephen P., E-mail: spcramer@lbl.gov [University of California, Department of Applied Science (United States)

    2013-12-15

    We have applied {sup 57}Fe nuclear resonance vibrational spectroscopy (NRVS) for the first time to study the dynamics of Fe centers in Iron-sulfur protein crystals, including oxidized wild type rubredoxin crystals from Pyrococcus furiosus, and the MoFe protein of nitrogenase from Azotobacter vinelandii. Thanks to the NRVS selection rule, selectively probed vibrational modes have been observed in both oriented rubredoxin and MoFe protein crystals. The NRVS work was complemented by extended X-ray absorption fine structure spectroscopy (EXAFS) measurements on oxidized wild type rubredoxin crystals from Pyrococcus furiosus. The EXAFS spectra revealed the Fe-S bond length difference in oxidized Pf Rd protein, which is qualitatively consistent with the crystal structure.

  4. The Collinear Resonance Ionization Spectroscopy (CRIS) experimental setup at CERN-ISOLDE

    CERN Document Server

    Cocolios, T E; Procter, T J; Rothe, S; Garcia Ruiz, R F; Stroke, H H; Rossel, R E; Heylen, H; Franchoo, S; Marsh, B A; Verney, D; Papuga, J; Strashnov, I; Billowes, J; de Groote, R P; Le Blanc, F; Simpson, G S; Fedosseev, V N; Lynch, K M; Wood, R T; Budincevic, I; Mason, P J R; Wendt, K D A; Flanagan, K T; De Schepper, S; Rajabali, M M; Al Suradi, H H; Walker, P M; Smith, A J

    2013-01-01

    The CRIS setup at CERN-ISOLDE is a laser spectroscopy experiment dedicated to the high-resolution study of the spin, hyperfine structure and isotope shift of radioactive nuclei with low production rates (a few per second). It combines the Doppler-free resolution of the in-flight collinear geometry with the high detection efficiency of resonant ionisation. A recent commissioning campaign has demonstrated a 1\\% experimental efficiency, and as low as a 0.001\\% non-resonant ionisation. The current status of the experiment and its recent achievements with beams of francium isotopes are reported. The first identified systematic effects are discussed. (C) 2013 The Authors. Published by Elsevier B.V. All rights reserved.

  5. Resonant ionization spectroscopy of autoionizing Rydberg states in cobalt and redetermination of its ionization potential

    Science.gov (United States)

    Liu, Y.; Gottwald, T.; Mattolat, C.; Wendt, K.

    2017-04-01

    Multi-step resonance ionization spectroscopy of cobalt has been performed using a hot-cavity laser ion source and three Ti:Sapphire lasers. The photoionization spectra revealed members of five new autoionizing Rydberg series that originate from three different lower levels of 3d 74s5s h 4F9/2, 3d 74s4d f 4G11/2, and 3d 74s4d f 4H13/2 and converge to the first four excited states of singly ionized Co. The analyses of the Rydberg series yield 63 564.689 ± 0.036 cm-1 as the first ionization potential of Co, which is an order of magnitude more accurate than the previous estimation. Using a three-step resonance ionization scheme that employs an autoinizing Rydberg state in the last transition, we obtained an overall ionization efficiency of about 18% for Co. ).

  6. Assessment of Isocitrate Dehydrogenase mutational status in cerebral gliomas by in vivo Magnetic Resonance Spectroscopy

    DEFF Research Database (Denmark)

    Tietze, Anna; Oettingen, Gorm von; Sangill, Ryan

    Background: The identification of mutations in the Isocitrate Dehydrogenase (IDH) gene in gliomas has considerable prognostic value, as patients with IDH-mutated tumors have a better overall survival than those without [1]. The IDH mutational status is therefore an important marker in the clinics...... and has the potential to open up for more personalized treatment approaches. It is usually assessed by immunohistochemistry or polymerase chain reaction (PCR) in tumor tissue obtained by surgical biopsies. IDH-mutated tumor cells accumulate 2-hydroxyglutarate (2-HG) that is present in very low...... concentrations in normal tissue or in gliomas with wildtype IDH. It has recently been shown that 2-HG is detectable non-invasively by clinical Magnetic Resonance Spectroscopy (MRS) [2]. The aim of our study is to establish 2-HG MRS in patients suspected for cerebral gliomas on a clinical Magnetic Resonance (MR...

  7. Application of Nonlinear Elastic Resonance Spectroscopy For Damage Detection In Concrete: An Interesting Story

    Energy Technology Data Exchange (ETDEWEB)

    Byers, Loren W. [Los Alamos National Laboratory; Ten Cate, James A. [Los Alamos National Laboratory; Johnson, Paul A. [Los Alamos National Laboratory

    2012-06-28

    Nonlinear resonance ultrasound spectroscopy experiments conducted on concrete cores, one chemically and mechanically damaged by alkali-silica reactivity, and one undamaged, show that this material displays highly nonlinear wave behavior, similar to many other damaged materials. They find that the damaged sample responds more nonlinearly, manifested by a larger resonant peak and modulus shift as a function of strain amplitude. The nonlinear response indicates that there is a hysteretic influence in the stress-strain equation of state. Further, as in some other materials, slow dynamics are present. The nonlinear response they observe in concrete is an extremely sensitive indicator of damage. Ultimately, nonlinear wave methods applied to concrete may be used to guide mixing, curing, or other production techniques, in order to develop materials with particular desired qualities such as enhanced strength or chemical resistance, and to be used for damage inspection.

  8. Double resonant absorption measurement of acetylene symmetric vibrational states probed with cavity ring down spectroscopy

    CERN Document Server

    Karhu, J; Vainio, M; Metsälä, M; Hoekstra, S; Halonen, L

    2016-01-01

    A novel mid-infrared/near-infrared double resonant absorption setup for studying infrared-inactive vibrational states is presented. A strong vibrational transition in the mid-infrared region is excited using an idler beam from a singly resonant continuous-wave optical parametric oscillator, to populate an intermediate vibrational state. High output power of the optical parametric oscillator and the strength of the mid-infrared transition result in efficient population transfer to the intermediate state, which allows measuring secondary transitions from this state with a high signal-to-noise ratio. A secondary, near-infrared transition from the intermediate state is probed using cavity ring down spectroscopy, which provides high sensitivity in this wavelength region. Due to the narrow linewidths of the excitation sources, the rovibrational lines of the secondary transition are measured with sub-Doppler resolution. The setup is used to access a previously unreported symmetric vibrational state of acetylene, $\

  9. Characterization of humic acids from tundra soils of northern Western Siberia by electron paramagnetic resonance spectroscopy

    Science.gov (United States)

    Chukov, S. N.; Ejarque, E.; Abakumov, E. V.

    2017-01-01

    Humic acids from polar soils—cryozems (Cryosols), gleyezems (Gleysols), and peat soils (Histosols)—have been studied by electron paramagnetic resonance spectroscopy. First information was acquired on the content of free radicals in humic acids from polar soils for the northern regions of Western Siberia (Gydan Peninsula, Belyi Island). It was found that polar soils are characterized by higher contents of free radicals than other zonal soils. This is related to the lower degree of humification of organic matter and the enhanced hydromorphism under continuous permafrost conditions. The low degree of organic matter humification in the cryolithozone was confirmed by the increased content of free radicals as determined by electron paramagnetic resonance, which indicates a low biothermodynamic stability of organic matter.

  10. The Collinear Resonance Ionization Spectroscopy (CRIS) experimental setup at CERN-ISOLDE

    Energy Technology Data Exchange (ETDEWEB)

    Cocolios, T.E., E-mail: Thomas.Elias.Cocolios@cern.ch [School of Physics and Astronomy, University of Manchester, Manchester M13 9PL (United Kingdom); ISOLDE, PH Department, CERN, CH-1211 Geneva-23 (Switzerland); Al Suradi, H.H. [University of Sharja, Sharja (United Arab Emirates); Billowes, J. [School of Physics and Astronomy, University of Manchester, Manchester M13 9PL (United Kingdom); Budinčević, I.; Groote, R.P. de; De Schepper, S. [Instituut voor Kern- en Stralingsfysika, KU Leuven, B-3001 Leuven (Belgium); Fedosseev, V.N. [EN Department, CERN, CH-1211 Geneva-23 (Switzerland); Flanagan, K.T. [School of Physics and Astronomy, University of Manchester, Manchester M13 9PL (United Kingdom); Franchoo, S. [Institut de Physique Nucléaire d’Orsay, F-91406 Orsay (France); Garcia Ruiz, R.F.; Heylen, H. [Instituut voor Kern- en Stralingsfysika, KU Leuven, B-3001 Leuven (Belgium); Le Blanc, F. [Institut de Physique Nucléaire d’Orsay, F-91406 Orsay (France); Lynch, K.M. [School of Physics and Astronomy, University of Manchester, Manchester M13 9PL (United Kingdom); ISOLDE, PH Department, CERN, CH-1211 Geneva-23 (Switzerland); Marsh, B.A. [EN Department, CERN, CH-1211 Geneva-23 (Switzerland); Mason, P.J.R. [Centre for Nuclear and Radiation Physics, University of Surrey, Guilford GU2 7XH (United Kingdom); Neyens, G.; Papuga, J. [Instituut voor Kern- en Stralingsfysika, KU Leuven, B-3001 Leuven (Belgium); Procter, T.J. [School of Physics and Astronomy, University of Manchester, Manchester M13 9PL (United Kingdom); Rajabali, M.M. [Instituut voor Kern- en Stralingsfysika, KU Leuven, B-3001 Leuven (Belgium); Rossel, R.E. [EN Department, CERN, CH-1211 Geneva-23 (Switzerland); Institut für Physik, Johannes Gutenberg Universität, D-55099 Mainz (Germany); and others

    2013-12-15

    Highlights: • CRIS has been performed successfully on francium isotopes at ISOLDE. • Efficiency >1% has been achieved, with background <0.001%. • The analysis shows scatter with literature values of ±0.7%. • Alpha-decay tagging of hyperfine spectrum components has been demonstrated. -- Abstract: The CRIS setup at CERN-ISOLDE is a laser spectroscopy experiment dedicated to the high-resolution study of the spin, hyperfine structure and isotope shift of radioactive nuclei with low production rates (a few per second). It combines the Doppler-free resolution of the in-flight collinear geometry with the high detection efficiency of resonant ionisation. A recent commissioning campaign has demonstrated a 1% experimental efficiency, and as low as a 0.001% non-resonant ionisation. The current status of the experiment and its recent achievements with beams of francium isotopes are reported. The first identified systematic effects are discussed.

  11. Investigation of Fat Metabolism during Antiobesity Interventions by Magnetic Resonance Imaging and Spectroscopy

    Directory of Open Access Journals (Sweden)

    Arunima Pola

    2014-01-01

    Full Text Available The focus of current treatments for obesity is to reduce the body weight or visceral fat, which requires longer duration to show effect. In this study, we investigated the short-term changes in fat metabolism in liver, abdomen, and skeletal muscle during antiobesity interventions including Sibutramine treatment and diet restriction in obese rats using magnetic resonance imaging, magnetic resonance spectroscopy, and blood chemistry. Sibutramine is an antiobesity drug that results in weight loss by increasing satiety and energy expenditure. The Sibutramine-treated rats showed reduction of liver fat and intramyocellular lipids on day 3. The triglycerides (TG decreased on day 1 and 3 compared to baseline (day 0. The early response/nonresponse in different fat depots will permit optimization of treatment for better clinical outcome rather than staying with a drug for longer periods.

  12. Localized surface plasmon resonances in nanostructures to enhance nonlinear vibrational spectroscopies: towards an astonishing molecular sensitivity

    Directory of Open Access Journals (Sweden)

    Dan Lis

    2014-11-01

    Full Text Available Vibrational transitions contain some of the richest fingerprints of molecules and materials, providing considerable physicochemical information. Vibrational transitions can be characterized by different spectroscopies, and alternatively by several imaging techniques enabling to reach sub-microscopic spatial resolution. In a quest to always push forward the detection limit and to lower the number of needed vibrational oscillators to get a reliable signal or imaging contrast, surface plasmon resonances (SPR are extensively used to increase the local field close to the oscillators. Another approach is based on maximizing the collective response of the excited vibrational oscillators through molecular coherence. Both features are often naturally combined in vibrational nonlinear optical techniques. In this frame, this paper reviews the main achievements of the two most common vibrational nonlinear optical spectroscopies, namely surface-enhanced sum-frequency generation (SE-SFG and surface-enhanced coherent anti-Stokes Raman scattering (SE-CARS. They can be considered as the nonlinear counterpart and/or combination of the linear surface-enhanced infrared absorption (SEIRA and surface-enhanced Raman scattering (SERS techniques, respectively, which are themselves a branching of the conventional IR and spontaneous Raman spectroscopies. Compared to their linear equivalent, those nonlinear vibrational spectroscopies have proved to reach higher sensitivity down to the single molecule level, opening the way to astonishing perspectives for molecular analysis.

  13. In Vivo Assessment of Neurotransmitters and Modulators with Magnetic Resonance Spectroscopy: Application to Schizophrenia

    Science.gov (United States)

    Wijtenburg, S. Andrea; Yang, Shaolin; Fischer, Bernard A.; Rowland, Laura M.

    2015-01-01

    In vivo measurement of neurotransmitters and modulators is now feasible with advanced proton magnetic resonance spectroscopy (1H-MRS) techniques. This review provides a basic tutorial of MRS, describes the methods available to measure brain glutamate, glutamine, γ-aminobutyric acid, glutathione, N-acetylaspartylglutamate, glycine, and serine at magnetic field strengths of 3Tesla or higher, and summarizes the neurochemical findings in schizophrenia. Overall, 1H-MRS holds great promise for producing biomarkers that can serve as treatment targets, prediction of disease onset, or illness exacerbation in schizophrenia and other brain diseases. PMID:25614132

  14. 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.

  15. Final Version: Orbital Specificity in the Unoccupied States of UO2 from Resonant Inverse Photoelectron Spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Tobin, J G; Yu, S W

    2012-03-12

    One of the crucial questions of all actinide electronic structure determinations is the issue of 5f versus 6d character and the distribution of these components across the density of states. Here, a break-though experiment is discussed, which has allowed the direct determination of the U5f and U6d contributions to the unoccupied density of states (UDOS) in Uranium Dioxide. A novel Resonant Inverse Photoelectron (RIPES) and X-ray Emission Spectroscopy (XES) investigation of UO{sub 2} is presented. It is shown that the U5f and U6d components are isolated and identified unambiguously.

  16. Gamma-irradiated ExtraVit M nutritive supplement studied by electron paramagnetic resonance spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Petrisor, Dina [Faculty of Physics, Babes-Bolyai University, 1A Kogalniceanu Street, 400084 Cluj-Napoca (Romania)], E-mail: dinapetrisor@yahoo.co.uk; Damian, Grigore; Simon, Simion [Faculty of Physics, Babes-Bolyai University, 1A Kogalniceanu Street, 400084 Cluj-Napoca (Romania)

    2008-04-15

    An unirradiated and {gamma}-irradiated nutritive supplement named ExtraVit M was studied by electron paramagnetic resonance (EPR) spectroscopy in order to detect stable paramagnetic species following improvement of hygienic quality by {gamma}-radiation. Free radicals were induced by {gamma}-radiation in the studied samples from low absorbed doses, showing a certain sensibility of these samples to the radiation treatment. The EPR spectrum of irradiated ExtraVit M is typical for drugs or nutritive supplements containing high levels of sugars, vitamin C and cellulose.

  17. Amantadine DNA interaction as studied by classical and resonance Raman spectroscopy

    Science.gov (United States)

    Staničová, J.; Fabriciová, G.; Chinsky, L.; Šutiak, V.; Miškovský, P.

    1999-03-01

    The interaction of the antiviral agent amantadine with calf thymus DNA was studied by classical and UV-resonance Raman spectroscopy. It was found that: (i) the drug interacts with purine bases adenine and guanine via hydrogen bonds formation between N7 positions of purines and amino group of amantadine and (ii) the interaction leads to partial DNA structure change, which is demonstrated by a deformation of the hydrogen bonds of the A-T base pairs and by a partial deformation of the sugar-phosphate backbone of DNA, which does not lead to the DNA conformation transition.

  18. Measurements of vitamin B12 in human blood serum using resonance Raman spectroscopy

    Science.gov (United States)

    Tsiminis, G.; Schartner, E. P.; Brooks, J. L.; Hutchinson, M. R.

    2016-12-01

    Vitamin B12 (cobalamin and its derivatives) deficiency has been identified as a potential modifiable risk factor for dementia and Alzheimer's disease. Chronic deficiency of vitamin B12 has been significantly associated with an increased risk of cognitive decline. An effective and efficient method for measuring vitamin B12 concentration in human blood would enable ongoing tracking and assessment of this potential modifiable risk factor. In this work we present an optical sensor based on resonance Raman spectroscopy for rapid measurements of vitamin B12 in human blood serum. The measurement takes less than a minute and requires minimum preparation (centrifuging) of the collected blood samples.

  19. Magnetic resonance spectroscopy-guided transperineal prostate biopsy and brachytherapy for recurrent prostate cancer.

    Science.gov (United States)

    Barnes, Agnieszka Szot; Haker, Steven J; Mulkern, Robert V; So, Minna; D'Amico, Anthony V; Tempany, Clare M

    2005-12-01

    Brachytherapy targeted to the peripheral zone with magnetic resonance imaging (MRI) guidance is a prostate cancer treatment option with potentially fewer complications than other treatments. Follow-up MRI when failure is suspected is, however, difficult because of radiation-induced changes. Furthermore, MR spectroscopy (MRS) is compromised by susceptibility artifacts from radioactive seeds in the peripheral zone. We report a case in which combined MRI/MRS was useful for the detection of prostate cancer in the transitional zone in patients previously treated with MR-guided brachytherapy. We propose that MRI/MRS can help detect recurrent prostate cancer, guide prostate biopsy, and help manage salvage treatment decisions.

  20. Measurement of electron paramagnetic resonance using terahertz time-domain spectroscopy.

    Science.gov (United States)

    Kozuki, Kohei; Nagashima, Takeshi; Hangyo, Masanori

    2011-12-05

    We present a frequency-domain electron spin resonance (ESR) measurement system using terahertz time-domain spectroscopy. A crossed polarizer technique is utilized to increase the sensitivity in detecting weak ESR signals of paramagnets caused by magnetic dipole transitions between magnetic sublevels. We demonstrate the measurements of ESR signal of paramagnetic copper(II) sulfate pentahydrate with uniaxial anisotropy of the g-factor under magnetic fields up to 10 T. The lineshape of the obtained ESR signals agrees well with the theoretical predictions for a powder sample with the uniaxial anisotropy.

  1. Phase-resolved optical emission spectroscopy for an electron cyclotron resonance etcher

    Energy Technology Data Exchange (ETDEWEB)

    Milosavljevic, Vladimir [BioPlasma Research Group, Dublin Institute of Technology, Sackville Place, Dublin 1 (Ireland); Biosystems Engineering, University College Dublin, Dublin 4, Ireland and Faculty of Physics, University of Belgrade, Belgrade (Serbia); MacGearailt, Niall; Daniels, Stephen; Turner, Miles M. [NCPST, Dublin City University, Dublin (Ireland); Cullen, P. J. [BioPlasma Research Group, Dublin Institute of Technology, Sackville Place, Dublin 1 (Ireland)

    2013-04-28

    Phase-resolved optical emission spectroscopy (PROES) is used for the measurement of plasma products in a typical industrial electron cyclotron resonance (ECR) plasma etcher. In this paper, the PROES of oxygen and argon atoms spectral lines are investigated over a wide range of process parameters. The PROES shows a discrimination between the plasma species from gas phase and those which come from the solid phase due to surface etching. The relationship between the micro-wave and radio-frequency generators for plasma creation in the ECR can be better understood by the use of PROES.

  2. Hypothalamic metabolic compartmentation during appetite regulation as revealed by magnetic resonance imaging and spectroscopy methods

    Science.gov (United States)

    Lizarbe, Blanca; Benitez, Ania; Peláez Brioso, Gerardo A.; Sánchez-Montañés, Manuel; López-Larrubia, Pilar; Ballesteros, Paloma; Cerdán, Sebastián

    2013-01-01

    We review the role of neuroglial compartmentation and transcellular neurotransmitter cycling during hypothalamic appetite regulation as detected by Magnetic Resonance Imaging (MRI) and Spectroscopy (MRS) methods. We address first the neurochemical basis of neuroendocrine regulation in the hypothalamus and the orexigenic and anorexigenic feed-back loops that control appetite. Then we examine the main MRI and MRS strategies that have been used to investigate appetite regulation. Manganese-enhanced magnetic resonance imaging (MEMRI), Blood oxygenation level-dependent contrast (BOLD), and Diffusion-weighted magnetic resonance imaging (DWI) have revealed Mn2+ accumulations, augmented oxygen consumptions, and astrocytic swelling in the hypothalamus under fasting conditions, respectively. High field 1H magnetic resonance in vivo, showed increased hypothalamic myo-inositol concentrations as compared to other cerebral structures. 1H and 13C high resolution magic angle spinning (HRMAS) revealed increased neuroglial oxidative and glycolytic metabolism, as well as increased hypothalamic glutamatergic and GABAergic neurotransmissions under orexigenic stimulation. We propose here an integrative interpretation of all these findings suggesting that the neuroendocrine regulation of appetite is supported by important ionic and metabolic transcellular fluxes which begin at the tripartite orexigenic clefts and become extended spatially in the hypothalamus through astrocytic networks becoming eventually MRI and MRS detectable. PMID:23781199

  3. Accurate measurement of cortical bone elasticity tensor with resonant ultrasound spectroscopy.

    Science.gov (United States)

    Bernard, Simon; Grimal, Quentin; Laugier, Pascal

    2013-02-01

    Resonant ultrasound spectroscopy (RUS) allows to accurately characterize the complete set of elastic constants of an anisotropic material from a set of measured mechanical resonant frequencies of a specimen. This method does not suffer from the drawbacks and limitations of the conventional sound velocity approach, but has been reported to fail to measure bone because of its strong viscoelastic damping. In this study, we take advantage of recent developments of RUS to overcome this limitation. The frequency response of a human cortical bone specimen (about 5 × 7 × 7 mm(3)) was measured between 100 and 280 kHz. Despite an important overlapping of the resonant peaks 20 resonant frequencies could be retrieved by using a dedicated signal processing method. The experimental frequencies were progressively matched to the frequencies predicted by a model of the sample whose elastic constants were adjusted. The determined diagonal elastic constants were in good agreement with concurrent sound velocity measurements performed in the principal directions of the specimen. This study demonstrates that RUS is suitable for an accurate measurement of cortical bone anisotropic elasticity. In particular, precision of measured Young and shear moduli is about 0.5%. Copyright © 2012 Elsevier Ltd. All rights reserved.

  4. Role of magnetic resonance venography in evaluation of cerebral ...

    African Journals Online (AJOL)

    Eman Abd-El Latif Abd-Elaziz El Damarawy

    2011-12-14

    Dec 14, 2011 ... Objective: To assess the role of magnetic resonance venography in the evaluation of cerebral veins and sinuses occlusion. Methods: The study was conducted on 15 patients with cerebral venous occlusion and subjected to. MRI and MRV. Abbreviations: MRI, magnetic resonance imaging; MRV, magnetic.

  5. Comparative analysis between findings of magnetic resonance spectroscopy of the masseter muscle in patients with and without temporomandibular disorder: part III

    OpenAIRE

    Luiz Fernando Giazzi NASSRI; ABDALA, NITAMAR; Szejnfeld, Jacob [UNIFESP; Maria Renata Giazzi NASSRI

    2009-01-01

    Objective: To evaluate the possible modifications of the massetermuscle regarding the metabolites – creatine, choline and lipid – inpatients with and without temporomandibular joint disorder (TMD)trough magnetic resonance spectroscopy sequence. Material andmethods: 20 volunteers were selected (11 without TMD and 9 withTMD), with full dentition and Angle class I occlusion. Results: Therelationship between the metabolites was preserved in both groups,but it showed an increasing tendency of the ...

  6. A cross-validation of near-infrared spectroscopy measurements of skeletal muscle oxidative capacity with phosphorus magnetic resonance spectroscopy.

    Science.gov (United States)

    Ryan, Terence E; Southern, W Michael; Reynolds, Mary Ann; McCully, Kevin K

    2013-12-01

    The purpose of this study was to cross-validate measurements of skeletal muscle oxidative capacity made with near-infrared spectroscopy (NIRS) measurements to those made with phosphorus magnetic resonance spectroscopy ((31)P-MRS). Sixteen young (age = 22.5 ± 3.0 yr), healthy individuals were tested with both (31)P-MRS and NIRS during a single testing session. The recovery rate of phosphocreatine was measured inside the bore of a 3-Tesla MRI scanner, after short-duration (∼10 s) plantar flexion exercise as an index of skeletal muscle oxidative capacity. Using NIRS, the recovery rate of muscle oxygen consumption was also measured using repeated, transient arterial occlusions outside the MRI scanner, after short-duration (∼10 s) plantar flexion exercise as another index of skeletal muscle oxidative capacity. The average recovery time constant was 31.5 ± 8.5 s for phosphocreatine and 31.5 ± 8.9 s for muscle oxygen consumption for all participants (P = 0.709). (31)P-MRS time constants correlated well with NIRS time constants for both channel 1 (Pearson's r = 0.88, P < 0.0001) and channel 2 (Pearson's r = 0.95, P < 0.0001). Furthermore, both (31)P-MRS and NIRS exhibit good repeatability between trials (coefficient of variation = 8.1, 6.9, and 7.9% for NIRS channel 1, NIRS channel 2, and (31)P-MRS, respectively). The good agreement between NIRS and (31)P-MRS indexes of skeletal muscle oxidative capacity suggest that NIRS is a valid method for assessing mitochondrial function, and that direct comparisons between NIRS and (31)P-MRS measurements may be possible.

  7. Profiling planktonic biomass using element-specific, multicomponent nuclear magnetic resonance spectroscopy.

    Science.gov (United States)

    Komatsu, Takanori; Kobayashi, Toshiya; Hatanaka, Minoru; Kikuchi, Jun

    2015-06-02

    Planktonic metabolism plays crucial roles in Earth's elemental cycles. Chemical speciation as well as elemental stoichiometry is important for advancing our understanding of planktonic roles in biogeochemical cycles. In this study, a multicomponent solid-state nuclear magnetic resonance (NMR) approach is proposed for chemical speciation of cellular components, using several advanced NMR techniques. Measurements by ssNMR were performed on (13)C and (15)N-labeled Euglena gracilis, a flagellated protist. 3D dipolar-assisted rotational resonance, double-cross-polarization (1)H-(13)C correlation spectroscopy, and (1)H-(13)C solid-state heteronuclear single quantum correlation spectroscopy successively allowed characterization of cellular components. These techniques were then applied to E. gracilis cultured in high and low ammonium media to demonstrate the power of this method for profiling and comparing cellular components. Cellular NMR spectra indicated that ammonium induced both paramylon degradation and amination. Arginine was stored as a nitrogen reserve and ammonium replaced by arginine catabolism via the arginine dihydrolase pathway. (15)N and (31)P cellular ssNMR indicated arginine and polyphosphate accumulation in E. gracilis, respectively. This chemical speciation technique will contribute to environmental research by providing detailed information on environmental chemical properties.

  8. Improved Cardiac Proton Magnetic Resonance Spectroscopy at 3 T Using High Permittivity Pads.

    Science.gov (United States)

    de Heer, Paul; Bizino, Maurice B; Versluis, Maarten J; Webb, Andrew G; Lamb, Hildo J

    2016-02-01

    The aim of this study was to determine whether high permittivity (HP) pads can be used to increase the signal-to-noise ratio (SNR) of cardiac proton magnetic resonance spectroscopy at 3 T, allowing faster data acquisition. The institutional review board approved the study protocol, and written informed consent was obtained from all participants. In 22 healthy volunteers, water-suppressed localized spectra were acquired in the interventricular septum without and with HP pads. The SNR and myocardial triglyceride content (MTGC) were measured without and with the HP pads, and the results were compared with a paired sample Student t test. Application of HP pads increased mean (SD) SNR from 27.9 (15.6) to 42.3 (24.4) (P permittivity pads improve cardiac proton magnetic resonance spectroscopy at 3 T by increasing the SNR on average by 60%, which can be used to reduce data acquisition time significantly, allowing fast assessment of MTGC without compromising spectral quality. The SNR increase arises primarily from the increase in receive sensitivity of the phased array, which is more closely coupled to the body via the HP pads. In addition, the transmit efficiency is also increased, allowing shorter or lower power radiofrequency pulses.

  9. In vivo phosphorus 31 magnetic resonance spectroscopy of rat hind limb skeletal muscle during sepsis.

    Science.gov (United States)

    Jacobs, D O; Maris, J; Fried, R; Settle, R G; Rolandelli, R R; Koruda, M J; Chance, B; Rombeau, J L

    1988-11-01

    High-energy phosphate metabolism in skeletal muscle is altered during sepsis, although the chronology of events is uncertain. Phosphorus 31 magnetic resonance spectroscopy was used to measure changes in muscle energy stores of the left hind limb musculature of adult male rats during sepsis. Following control scans, cecal ligation and puncture were performed and scanning was repeated 6, 24, and 48 hours after surgery. The ratios of phosphocreatine (PCr) to inorganic phosphate (Pi), a measure of energy stores, and adenosine triphosphate (ATP) to Pi ratio, a measure of the energy available for immediate use, were determined from peak heights. Intracellular pH was calculated using the distance between Pi and PCr peaks. In surviving animals, a 40% decrease in PCr/Pi ratio (+/- SEM) was observed by 24 hours (22.3 +/- 3.0 at time 0 vs 13.3 +/- 2.8 at 24 hours), whereas energy availability (beta-ATP/Pi) was statistically unchanged (18.2 +/- 2.2 at time 0 vs 15.2 +/- 1.2 at 48 hours). Intracellular pH did not change. Both PCr/Pi and ATP/Pi ratios were inversely correlated with time. In this model of documented peritonitis, skeletal muscle energy metabolism is rapidly altered following severe infection, and these changes can be detected using 31P magnetic resonance spectroscopy.

  10. Characterization of the pigment xanthomonadin in the bacterial genus Xanthomonas using micro- and resonance Raman spectroscopy

    Science.gov (United States)

    Paret, Mathews L.; Sharma, Shiv K.; Misra, Anupam K.; Acosta, Tayro; deSilva, Asoka S.; Vowell, Tomie; Alvarez, Anne M.

    2012-06-01

    We used micro- and resonance Raman spectroscopy with 785 nm and 514.5 nm laser excitation, respectively, to characterize a plant pathogenic bacteria, Xanthomonas axonopodis pv. dieffenbachiae D150. The bacterial genus Xathomonas is closely related to bacterial genus Stenotrophomonas that causes an infection in humans. This study has identified for the first time the unique Raman spectra of the carotenoid-like pigment xanthomonadin of the Xanthomonas strain. Xanthomonadin is a brominated aryl-polyene pigment molecule similar to carotenoids. Further studies were conducted using resonance Raman spectroscopy with 514.5 nm laser excitation on several strains of the bacterial genus Xanthomonas isolated from numerous plants from various geographical locations. The current study revealed that the Raman bands representing the vibrations (v1, v2, v3) of the polyene chain of xanthomonadin are 1003-1005 (v3), 1135-1138 (v2), and 1530 (v1). Overtone bands representing xanthomonadin were identified as 2264-2275 (2v2), and combinational bands at 2653-2662 (v1+ v2). The findings from this study validate our previous finding that the Raman fingerprints of xanthomonadin are unique for the genus Xanthomonas. This facilitates rapid identification (~5 minutes) of Xanthomonas spp. from bacterial culture plates. The xanthomonadin marker is different from Raman markers of many other bacterial genus including Agrobacterium, Bacillus, Clavibacter, Enterobacter, Erwinia, Microbacterium, Paenibacillus, and Ralstonia. This study also identified Xanthomonas spp. from bacterial strains isolated from a diseased wheat sample on a culture plate.

  11. The Utility of Magnetic Resonance Spectroscopy for Understanding Substance Use Disorders: A Systematic Review of the Literature.

    Science.gov (United States)

    Hellem, Tracy; Shi, Xianfeng; Latendresse, Gwen; Renshaw, Perry F

    2015-01-01

    The aim of this article is to present a systematic review of magnetic resonance spectroscopy (MRS) studies of substance use disorders. As a noninvasive and nonionizing imaging technique, MRS is being widely used in substance abuse research to evaluate the effects substances of abuse have on brain chemistry. Nearly 40 peer-reviewed research articles that focused on the utility of MRS in alcohol, methamphetamine, 3,4-methylenedioxymethamphetamine, cocaine, opiates, opioids, marijuana, and nicotine use disorders were reviewed. Findings indicate inconsistencies with respect to alterations in brain chemistry within each substance of abuse, and the most consistent finding across substances was decreased N-acetylaspartate and choline levels with chronic alcohol, methamphetamine, and nicotine use. Variation in the brain regions studied, imaging technique, as well as small sample sizes might explain the discrepancies in findings within each substance. Future well-designed MRS studies offer promise in examining novel treatment approaches in substance use disorders. © The Author(s) 2015.

  12. Cortical bone elasticity measured by resonant ultrasound spectroscopy is not altered by defatting and synchrotron X-ray imaging.

    Science.gov (United States)

    Cai, X; Peralta, L; Giron, A; Helfen, L; Olivier, C; Peyrin, F; Laugier, P; Grimal, Q

    2017-08-01

    In the study of mechanical properties of human bone, specimens may be defatted before experiments to prevent contamination and the risk of infections. High energy synchrotron radiation micro-computed tomography (SR-μCT) is a popular technique to study bone microstructure. However, little is known about the effects of defatting or irradiation during SR-μCT imaging on different elastic coefficients including shear and longitudinal moduli in different anatomical directions. In this work, these effects are evaluated on a set of 24 samples using resonant ultrasound spectroscopy (RUS), which allows one to accurately measure the complete set of elastic coefficients of cortical bone non destructively. The results show that defatting with diethylether and methanol and irradiation up to 2.5kGy has no detectable effect on any of the elastic coefficients of human cortical bone. Copyright © 2017. Published by Elsevier Ltd.

  13. Evaluation of stable tungsten isotopes in the resolved resonance region

    Directory of Open Access Journals (Sweden)

    Schillebeeckx P.

    2013-03-01

    Full Text Available In the last decade benchmark experiments and simulations, together with newly obtained neutron cross section data, have pointed out deficiencies in evaluated data files of W isotopes. The role of W as a fundamental structural material in different nuclear applications fully justifies a new evaluation of 182, 183, 184, 186W neutron resonance parameters. In this regard transmission and capture cross section measurements on natural and enriched tungsten samples were performed at the GELINA facility of the EC-JRC-IRMM. A resonance parameter file used as input in the resonance shape analysis was prepared based on the available literature and adjusted in first instance to transmission data.

  14. Laser Spectroscopy of CW Optical-Optical Double Resonance and All-Optical Triple Resonance in Diatomic Sodium Molecules

    Science.gov (United States)

    Whang, Thou-Jen

    The sodium dimer is one of the most interesting molecules studied since the last century due to its simplicity both in theory and in experiment. In this study the Na _2 2^1 Pi _ {rm g} state has been extensively studied through the intermediate A^1Sigma _sp{rm u}{+} state by optical-optical double resonance (OODR) spectroscopy and the 2^3Delta_{rm g}, 3^3Sigma_sp {rm g}{+}, 1^3 Delta_{rm g}, 2 ^3Pi_{rm g}, and 4^3Sigma_sp{rm g}{+} states have been either newly observed or extensively studied through the intermediate perturbed A^1Sigma_sp{ rm u}{+} ~ b^3Pi_{rm u}nuclear hyperfine structures. For these states, most of the Dunham coefficients, RKR potential curves, and absolute vibrational numberings have been determined and are presented in tables and figures. The second part of this work is the spectroscopic study in the Na_2 b^3 Pi_{rm u} state by the perturbation-facilitated optical-optical double resonance -stimulated emission pumping technique (PFOODR-SEP). Because of the spin-forbidden transition from the thermally populated ground state to the b^3Pi_ {rm u} state, it is difficult to investigate the b state except for those levels perturbed by the A^1Sigma_sp{rm u}{+} state due to the spin-orbit interaction. In this study the b^3Pi _{Omega u} state (Omega = 0, 1, and 2 components) has been reached in the region of lower vibrational levels and of higher vibrational levels, most of which are unperturbed. The resultant Dunham coefficients have been obtained from deperturbed molecular constants of each vibrational level. The value of this newly developed technique (all-optical triple resonance) is, however, not only that it can detect unperturbed levels in the b state inaccessible from single photon transition but also that it can generally reduce restrictions imposed by the Franck-Condon principle or by symmetry selection rules. Thus, for example, one can now investigate the long-range molecules such as in the A^1 Sigma_sp{rm u}{+} state and state

  15. Atom-at-a-time laser resonance ionization spectroscopy of nobelium.

    Science.gov (United States)

    Laatiaoui, Mustapha; Lauth, Werner; Backe, Hartmut; Block, Michael; Ackermann, Dieter; Cheal, Bradley; Chhetri, Premaditya; Düllmann, Christoph Emanuel; van Duppen, Piet; Even, Julia; Ferrer, Rafael; Giacoppo, Francesca; Götz, Stefan; Heßberger, Fritz Peter; Huyse, Mark; Kaleja, Oliver; Khuyagbaatar, Jadambaa; Kunz, Peter; Lautenschläger, Felix; Mistry, Andrew Kishor; Raeder, Sebastian; Ramirez, Enrique Minaya; Walther, Thomas; Wraith, Calvin; Yakushev, Alexander

    2016-10-27

    Optical spectroscopy of a primordial isotope has traditionally formed the basis for understanding the atomic structure of an element. Such studies have been conducted for most elements and theoretical modelling can be performed to high precision, taking into account relativistic effects that scale approximately as the square of the atomic number. However, for the transfermium elements (those with atomic numbers greater than 100), the atomic structure is experimentally unknown. These radioactive elements are produced in nuclear fusion reactions at rates of only a few atoms per second at most and must be studied immediately following their production, which has so far precluded their optical spectroscopy. Here we report laser resonance ionization spectroscopy of nobelium (No; atomic number 102) in single-atom-at-a-time quantities, in which we identify the ground-state transition 1S01P1. By combining this result with data from an observed Rydberg series, we obtain an upper limit for the ionization potential of nobelium. These accurate results from direct laser excitations of outer-shell electrons cannot be achieved using state-of-the-art relativistic many-body calculations that include quantum electrodynamic effects, owing to large uncertainties in the modelled transition energies of the complex systems under consideration. Our work opens the door to high-precision measurements of various atomic and nuclear properties of elements heavier than nobelium, and motivates future theoretical work.

  16. Developments for resonance ionization laser spectroscopy of the heaviest elements at SHIP

    Science.gov (United States)

    Lautenschläger, F.; Chhetri, P.; Ackermann, D.; Backe, H.; Block, M.; Cheal, B.; Clark, A.; Droese, C.; Ferrer, R.; Giacoppo, F.; Götz, S.; Heßberger, F. P.; Kaleja, O.; Khuyagbaatar, J.; Kunz, P.; Mistry, A. K.; Laatiaoui, M.; Lauth, W.; Raeder, S.; Walther, Th.; Wraith, C.

    2016-09-01

    The experimental determination of atomic levels and the first ionization potential of the heaviest elements (Z ⩾ 100) is key to challenge theoretical predictions and to reveal changes in the atomic shell structure. These elements are only artificially produced in complete-fusion evaporation reactions at on-line facilities such as the GSI in Darmstadt at a rate of, at most, a few atoms per second. Hence, highly sensitive spectroscopic methods are required. Laser spectroscopy is one of the most powerful and valuable tools to investigate atomic properties. In combination with a buffer-gas filled stopping cell, the Radiation Detected Resonance Ionization Spectroscopy (RADRIS) technique provides the highest sensitivity for laser spectroscopy on the heaviest elements. The RADRIS setup, as well as the measurement procedure, have been optimized and characterized using the α -emitter 155 Yb in on-line conditions, resulting in an overall efficiency well above 1%. This paves the way for a successful search of excited atomic levels in nobelium and heavier elements.

  17. Atom-at-a-time laser resonance ionization spectroscopy of nobelium

    Science.gov (United States)

    Laatiaoui, Mustapha; Lauth, Werner; Backe, Hartmut; Block, Michael; Ackermann, Dieter; Cheal, Bradley; Chhetri, Premaditya; Düllmann, Christoph Emanuel; van Duppen, Piet; Even, Julia; Ferrer, Rafael; Giacoppo, Francesca; Götz, Stefan; Heßberger, Fritz Peter; Huyse, Mark; Kaleja, Oliver; Khuyagbaatar, Jadambaa; Kunz, Peter; Lautenschläger, Felix; Mistry, Andrew Kishor; Raeder, Sebastian; Ramirez, Enrique Minaya; Walther, Thomas; Wraith, Calvin; Yakushev, Alexander

    2016-10-01

    Optical spectroscopy of a primordial isotope has traditionally formed the basis for understanding the atomic structure of an element. Such studies have been conducted for most elements and theoretical modelling can be performed to high precision, taking into account relativistic effects that scale approximately as the square of the atomic number. However, for the transfermium elements (those with atomic numbers greater than 100), the atomic structure is experimentally unknown. These radioactive elements are produced in nuclear fusion reactions at rates of only a few atoms per second at most and must be studied immediately following their production, which has so far precluded their optical spectroscopy. Here we report laser resonance ionization spectroscopy of nobelium (No; atomic number 102) in single-atom-at-a-time quantities, in which we identify the ground-state transition 1S0 1P1. By combining this result with data from an observed Rydberg series, we obtain an upper limit for the ionization potential of nobelium. These accurate results from direct laser excitations of outer-shell electrons cannot be achieved using state-of-the-art relativistic many-body calculations that include quantum electrodynamic effects, owing to large uncertainties in the modelled transition energies of the complex systems under consideration. Our work opens the door to high-precision measurements of various atomic and nuclear properties of elements heavier than nobelium, and motivates future theoretical work.

  18. Resonance Effects in the Ultraviolet Raman Spectroscopy of Collagen in Mineralized Tissues

    Science.gov (United States)

    Ager, J. W., III; Pugach, M.; Habelitz, S.; Balooch, G.; Kinney, J. H.; Marshall, G. W.; Ritchie, R. O.

    2007-03-01

    Ultraviolet resonance Raman spectroscopy (UVRRS) was used to investigate type I collagen in solid tissues including tendon, dentin, and bone. With 244 nm excitation, spectral features from both the amide backbone (amide I, II, and III) and resonance-enhanced side-chain vibrations (Y8a, tyrosine) were observed. This contrasts with reported Raman spectra of proteins in solution excited with similar UV wavelengths, where side chain vibrations, but not strong amide features, are observed. The height of the dominant amide I feature in teeth and bone can be reversibly increased/decreased in dentin by dehydration/rehydration cycles. Also, the amide I peak is relatively stronger in both human bone and dentin from older donors. The strong intensity of the amide I UVRRS feature in these mineralized tissues is attributed to an increase in the width of the π-> π^* amide resonance in collagen compared to the solution phase. These findings suggest that UVRRS can be used as a specific probe of the collagen environment in bone and dentin.

  19. Preliminary identification of unicellular algal genus by using combined confocal resonance Raman spectroscopy with PCA and DPLS analysis

    Science.gov (United States)

    He, Shixuan; Xie, Wanyi; Zhang, Ping; Fang, Shaoxi; Li, Zhe; Tang, Peng; Gao, Xia; Guo, Jinsong; Tlili, Chaker; Wang, Deqiang

    2018-02-01

    The analysis of algae and dominant alga plays important roles in ecological and environmental fields since it can be used to forecast water bloom and control its potential deleterious effects. Herein, we combine in vivo confocal resonance Raman spectroscopy with multivariate analysis methods to preliminary identify the three algal genera in water blooms at unicellular scale. Statistical analysis of characteristic Raman peaks demonstrates that certain shifts and different normalized intensities, resulting from composition of different carotenoids, exist in Raman spectra of three algal cells. Principal component analysis (PCA) scores and corresponding loading weights show some differences from Raman spectral characteristics which are caused by vibrations of carotenoids in unicellular algae. Then, discriminant partial least squares (DPLS) classification method is used to verify the effectiveness of algal identification with confocal resonance Raman spectroscopy. Our results show that confocal resonance Raman spectroscopy combined with PCA and DPLS could handle the preliminary identification of dominant alga for forecasting and controlling of water blooms.

  20. Assembling a prototype resonance electrical impedance spectroscopy system for breast tissue signal detection: preliminary assessment

    Science.gov (United States)

    Sumkin, Jules; Zheng, Bin; Gruss, Michelle; Drescher, John; Leader, Joseph; Good, Walter; Lu, Amy; Cohen, Cathy; Shah, Ratan; Zuley, Margarita; Gur, David

    2008-03-01

    Using electrical impedance spectroscopy (EIS) technology to detect breast abnormalities in general and cancer in particular has been attracting research interests for decades. Large clinical tests suggest that current EIS systems can achieve high specificity (>= 90%) at a relatively low sensitivity ranging from 15% to 35%. In this study, we explore a new resonance frequency based electrical impedance spectroscopy (REIS) technology to measure breast tissue EIS signals in vivo, which aims to be more sensitive to small tissue changes. Through collaboration between our imaging research group and a commercial company, a unique prototype REIS system has been assembled and preliminary signal acquisition has commenced. This REIS system has two detection probes mounted in the two ends of a Y-shape support device with probe separation of 60 mm. During REIS measurement, one probe touches the nipple and the other touches to an outer point of the breast. The electronic system continuously generates sweeps of multi-frequency electrical pulses ranging from 100 to 4100 kHz. The maximum electric voltage and the current applied to the probes are 1.5V and 30mA, respectively. Once a "record" command is entered, multi-frequency sweeps are recorded every 12 seconds until the program receives a "stop recording" command. In our imaging center, we have collected REIS measurements from 150 women under an IRB approved protocol. The database includes 58 biopsy cases, 78 screening negative cases, and other "recalled" cases (for additional imaging procedures). We measured eight signal features from the effective REIS sweep of each breast. We applied a multi-feature based artificial neural network (ANN) to classify between "biopsy" and normal "non-biopsy" breasts. The ANN performance is evaluated using a leave-one-out validation method and ROC analysis. We conducted two experiments. The first experiment attempted to classify 58 "biopsy" breasts and 58 "non-biopsy" breasts acquired on 58 women

  1. Biophysical Characterisation of Globins and Multi-Heme Cytochromes Using Electron Paramagnetic Resonance and Optical Spectroscopy

    Science.gov (United States)

    Desmet, Filip

    Heme proteins of different families were investigated in this work, using a combination of pulsed and continuous-wave electron paramagnetic resonance (EPR) spectroscopy, optical absorption spectroscopy, resonance Raman spectroscopy and laser flash photolysis. The first class of proteins that were investigated, were the globins. The globin-domain of the globin-coupled sensor of the bacterium Geobacter sulfurreducens was studied in detail using different pulsed EPR techniques (HYSCORE and Mims ENDOR). The results of this pulsed EPR study are compared with the results of the optical investigation and the crystal structure of the protein. The second globin, which was studied, is the Protoglobin of Methanosarcina acetivorans, various mutants of this protein were studied using laser flash photolysis and Raman spectroscopy to unravel the link between this protein's unusual structure and its ligand-binding kinetics. In addition to this, the CN -bound form of this protein was investigated using EPR and the influence of the strong deformation of the heme on the unusual low gz values is discussed. Finally, the neuroglobins of three species of fishes, Danio rerio, Dissostichus mawsoni and Chaenocephalus aceratus are studied. The influence of the presence or absence of two cysteine residues in the C-D and D-region of the protein on the EPR spectrum, and the possible formation of a disulfide bond is studied. The second group of proteins that were studied in this thesis belong to the family of the cytochromes. First the Mouse tumor suppressor cytochrome b561 was studied, the results of a Raman and EPR investigation are compared to the Human orthologue of the protein. Secondly, the tonoplast cytochrome b561 of Arabidopsis was investigated in its natural form and in two double-mutant forms, in which the heme at the extravesicular side was removed. The results of this investigation are then compared with two models in literature that predict the localisation of the hemes in this

  2. Adolescent anorexia nervosa: cross-sectional and follow-up frontal gray matter disturbances detected with proton magnetic resonance spectroscopy.

    Science.gov (United States)

    Castro-Fornieles, Josefina; Bargalló, Nuria; Lázaro, Luisa; Andrés, Susana; Falcon, Carles; Plana, Maria Teresa; Junqué, Carme

    2007-12-01

    There are very few magnetic resonance spectroscopy studies in anorexia nervosa and none of them with young adolescent patients. We studied 12 anorexia nervosa (DSM-IV) patients aged 11-17 consecutively admitted to an Eating Disorders Unit. An evaluation with laboratory data, psychopathological scales, magnetic resonance spectroscopy ((1)H MRS) and a neuropsychological battery was carried out at admission and after 7 months' follow-up and weight recovery. Psychopathological and neuropsychological and MRS examinations were also performed in 12 control subjects. In the MRS study at the frontal gray matter, the anorexic group had a significantly lower N-acetyl-aspartate (NAA) (p = .002), glutamate/glutamine (Glx) (p = .010) and myo-Inositol (mI) (p = .022) than the control group. The NAA correlated positive and significantly with triiodothyronin (Rho = .64) and the estimate level of intelligence measured with the vocabulary subtest of the WISC-R (Rho=.64). There were also positive correlations with body mass index (Rho = .47) and with attention measured with the coding subtest of the WISC-R (Rho=.51) and negative with loss of weight (Rho = -.51) but they were not statistically significant. At follow-up, there was an increase in body mass index (p=.002), triiodothyronin (p = .005), and insulin-like growth factor 1 (p = .017) and a decrease in cortisol (p = .005). In the MRS a significant increase (p = .013) in NAA was observed. The conclusion would be that NAA, Glx and mI are low in the frontal gray matter of adolescents with anorexia nervosa and specially NAA correlates with some nutritional and cognitive parameters. These alterations seem to be reversible in young patients.

  3. The relationship between choline plus creatine- to-citrate ratio in magnetic resonance spectroscopy with the invasion of prostate cancer

    Directory of Open Access Journals (Sweden)

    M Ghafoori

    2012-12-01

    Full Text Available Background: Prostate cancer is the most common cancer and the second cause of cancer mortality in men. Although histopathological examination is the gold-standard for its diagnosis, tendency toward less invasive methods is growing. The purpose of this study was to evaluate the relationship between choline plus creatine- to-citrate ratio in magnetic resonance spectroscopy (MRS with the invasion of prostate cancer in a series of patients with prostate cancer.Methods: Totally, 200 patients with pathologically proven prostate cancer were enrolled in this cross-sectional study by a non-probability sampling method in Hazrat Rasul Akram Hospital in Tehran, Iran during 2009-2010. Pathological staging was the gold standard for the diagnosis of prostate cancer while the patients underwent MRS for choline plus creatine- to-citrate ratio determination. MRS and pathological results were compared and analyzed.Results: The mean (±SD values of choline plus creatine- to-citrate ratio in patients with Gleason scores less than 3, 3 to 4 and greater than 4 were 245.8±146.8, 427.1±173.6 and 427.1±173.6, respectively (P<0.001. The mean (±SD values of choline plus creatine- to-citrate ratio in patients with PSA levels less than 4, 4 to 10 and greater than 10 were 180.7±58.3, 247±93.5 and 385.1±106.6, respectively (P<0.001.Conclusion: Choline plus creatine- to-citrate ratio determined by magnetic resonance spectroscopy has a significant relationship with the degree of invasion of prostate cancer and can be used for the staging of the disease.

  4. Ultraviolet radiation and nanoparticle induced intracellular free radicals generation measured in human keratinocytes by electron paramagnetic resonance spectroscopy.

    Science.gov (United States)

    Rancan, F; Nazemi, B; Rautenberg, S; Ryll, M; Hadam, S; Gao, Q; Hackbarth, S; Haag, S F; Graf, C; Rühl, E; Blume-Peytavi, U; Lademann, J; Vogt, A; Meinke, M C

    2014-05-01

    Several nanoparticle-based formulations used in cosmetics and dermatology are exposed to sunlight once applied to the skin. Therefore, it is important to study possible synergistic effects of nanoparticles and ultraviolet radiation. Electron paramagnetic resonance spectroscopy (EPR) was used to detect intracellular free radicals induced by ultraviolet B (UVB) radiation and amorphous silica nanoparticle and to evaluate the influence of nanoparticle surface chemistry on particle cytotoxicity toward HaCaT cells. Uncoated titanium dioxide nanoparticles served as positive control. In addition, particle intracellular uptake, viability, and induction of interleukin-6 were measured. We found that photo-activated titanium dioxide particles induced a significant amount of intracellular free radicals. On the contrary, no intracellular free radicals were generated by the investigated silica nanoparticles in the dark as well as under UVB radiation. However, under UVB exposure, the non-functionalized silica nanoparticles altered the release of IL-6. At the same concentrations, the amino-functionalized silica nanoparticles had no influence on UVB-induced IL-6 release. EPR spectroscopy is a useful technique to measure nanoparticle-induced intracellular free radicals. Non-toxic concentrations of silica particles enhanced the toxicity of UVB radiation. This synergistic effect was not mediated by particle-generated free radicals and correlated with particle surface charge and intracellular distribution. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  5. Application of a protocol for magnetic resonance spectroscopy of adrenal glands: an experiment with over 100 cases.

    Science.gov (United States)

    Melo, Homero José de Farias E; Goldman, Suzan M; Szejnfeld, Jacob; Faria, Juliano F; Huayllas, Martha K P; Andreoni, Cássio; Kater, Cláudio E

    2014-01-01

    To evaluate a protocol for two-dimensional (2D) hydrogen proton (1H) magnetic resonance spectroscopy (MRS) (Siemens Medical Systems; Erlangen, Germany) in the detection of adrenal nodules and differentiation between benign and malignant masses (adenomas, pheochromocytomas, carcinomas and metastases). A total of 118 patients (36 men; 82 women) (mean age: 57.3 ± 13.3 years) presenting with 138 adrenal nodules/masses were prospectively assessed. A multivoxel system was utilized with a 2D point-resolved spectroscopy/chemical shift imaging sequence. The following ratios were calculated: choline (Cho)/creatine (Cr), 4.0-4.3/Cr, lipid (Lip)/Cr, Cho/Lip and lactate (Lac)/Cr. 2D-1H-MRS was successful in 123 (89.13%) lesions. Sensitivity and specificity values observed for the ratios and cutoff points were the following: Cho/Cr ≥ 1.2, 100% sensitivity, 98.2% specificity (differences between adenomas/pheochromocytomas and carcinomas/ metastases); 4.0-4.3 ppm/Cr ≥ 1.5, 92.3% sensitivity, 96.9% specificity (differences between carcinomas/pheochromocytomas and adenomas/metastases); Lac/Cr ≤ -7.449, 90.9% sensitivity and 77.8% specificity (differences between pheochromocytomas and carcinomas/adenomas). Information provided by 2D-1H-MRS were effective and allowed for the differentiation between adrenal masses and nodules in most cases of lesions with > 1.0 cm in diameter.

  6. Evaluation of thyroid tissue by Raman spectroscopy

    Science.gov (United States)

    Teixeira, C. S. B.; Bitar, R. A.; Santos, A. B. O.; Kulcsar, M. A. V.; Friguglietti, C. U. M.; Martinho, H. S.; da Costa, R. B.; Martin, A. A.

    2010-02-01

    Thyroid gland is a small gland in the neck consisting of two lobes connected by an isthmus. Thyroid's main function is to produce the hormones thyroxine (T4), triiodothyronine (T3) and calcitonin. Thyroid disorders can disturb the production of these hormones, which will affect numerous processes within the body such as: regulating metabolism and increasing utilization of cholesterol, fats, proteins, and carbohydrates. The gland itself can also be injured; for example, neoplasias, which have been considered the most important, causing damage of to the gland and are difficult to diagnose. There are several types of thyroid cancer: Papillary, Follicular, Medullary, and Anaplastic. The occurrence rate, in general is between 4 and 7%; which is on the increase (30%), probably due to new technology that is able to find small thyroid cancers that may not have been found previously. The most common method used for thyroid diagnoses are: anamnesis, ultrasonography, and laboratory exams (Fine Needle Aspiration Biopsy- FNAB). However, the sensitivity of those test are rather poor, with a high rate of false-negative results, therefore there is an urgent need to develop new diagnostic techniques. Raman spectroscopy has been presented as a valuable tool for cancer diagnosis in many different tissues. In this work, 27 fragments of the thyroid were collected from 18 patients, comprising the following histologic groups: goitre adjacent tissue, goitre nodular tissue, follicular adenoma, follicular carcinoma, and papillary carcinoma. Spectral collection was done with a commercial FTRaman Spectrometer (Bruker RFS100/S) using a 1064 nm laser excitation and Ge detector. Principal Component Analysis, Cluster Analysis, and Linear Discriminant Analysis with cross-validation were applied as spectral classification algorithm. Comparing the goitre adjacent tissue with the goitre nodular region, an index of 58.3% of correct classification was obtained. Between goitre (nodular region and

  7. A clinical and magnetic resonance spectroscopy study of a brain tumor in a patient with segmental neurofibromatosis.

    Science.gov (United States)

    Chebel, S; Ben Yahia, S; Boughammoura-Bouatay, A; Salem, R; Golli, M; Khairallah, M; Frih-Ayed, M

    2010-08-01

    Segmental neurofibromatosis 1 (segmental NF-1) is a rare genodermatosis caused by somatic mutations in the NF-1 gene. It consists of localized characteristic skin lesions. A serial study using magnetic resonance imaging (MRI) and magnetic resonance spectroscopy (MRS) of a brain tumor in a 16-year-old patient with segmental NF-1 is reported. A 16-year-old boy with congenital dorsal scoliosis and segmental NF-1 was evaluated for bilateral optic atrophy. Neurological examination showed an isolated tetra pyramidal syndrome. The cerebral MRI showed a bilateral brain lesion involving the basal ganglia, optic pathways, temporal lobes, and the midbrain. Serial MRSs showed a decreased N-acetylaspartate (NAA)/creatine ratio and increased choline/creatine ratio. An increase in the myoinositol (MYO)/creatine ratio and the presence of a lipid/lactate peak were also recorded. A neuroimaging follow-up with MRI and MRS performed 2 years later showed similar findings. We describe an MRS study of a brain tumor in a patient with segmental NF-1 for the first time. The MRS study showed similar findings, described earlier in rare studies of patients with the classic form of NF-1. MRS is a noninvasive technique for detecting the presence of tumor tissue in the brain through its metabolic activity. MRS plays an important role in clinical studies and it can be used to differentiate malignant and nonmalignant brain lesions from normal brain tissue. Copyright (c) 2010 Elsevier Masson SAS. All rights reserved.

  8. Electron cyclotron resonance ion source plasma characterization by X-ray spectroscopy and X-ray imaging

    Energy Technology Data Exchange (ETDEWEB)

    Mascali, David, E-mail: davidmascali@lns.infn.it; Castro, Giuseppe; Celona, Luigi; Neri, Lorenzo; Gammino, Santo [INFN–Laboratori Nazionali del Sud, Via S. Sofia 62, 95125 Catania (Italy); Biri, Sándor; Rácz, Richárd; Pálinkás, József [Institute for Nuclear Research (Atomki), Hungarian Academy of Sciences, Bem tér 18/c, H-4026 Debrecen (Hungary); Caliri, Claudia [INFN–Laboratori Nazionali del Sud, Via S. Sofia 62, 95125 Catania (Italy); Università degli Studi di Catania, Dip.to di Fisica e Astronomia, via Santa Sofia 64, 95123 Catania (Italy); Romano, Francesco Paolo [INFN–Laboratori Nazionali del Sud, Via S. Sofia 62, 95125 Catania (Italy); CNR, Istituto per i Beni Archeologici e Monumentali, Via Biblioteca 4, 95124 Catania (Italy); Torrisi, Giuseppe [INFN–Laboratori Nazionali del Sud, Via S. Sofia 62, 95125 Catania (Italy); Università Mediterranea di Reggio Calabria, DIIES, Via Graziella, I-89100 Reggio Calabria (Italy)

    2016-02-15

    An experimental campaign aiming to investigate electron cyclotron resonance (ECR) plasma X-ray emission has been recently carried out at the ECRISs—Electron Cyclotron Resonance Ion Sources laboratory of Atomki based on a collaboration between the Debrecen and Catania ECR teams. In a first series, the X-ray spectroscopy was performed through silicon drift detectors and high purity germanium detectors, characterizing the volumetric plasma emission. The on-purpose developed collimation system was suitable for direct plasma density evaluation, performed “on-line” during beam extraction and charge state distribution characterization. A campaign for correlating the plasma density and temperature with the output charge states and the beam intensity for different pumping wave frequencies, different magnetic field profiles, and single-gas/gas-mixing configurations was carried out. The results reveal a surprisingly very good agreement between warm-electron density fluctuations, output beam currents, and the calculated electromagnetic modal density of the plasma chamber. A charge-coupled device camera coupled to a small pin-hole allowing X-ray imaging was installed and numerous X-ray photos were taken in order to study the peculiarities of the ECRIS plasma structure.

  9. Real-time assessment of Krebs cycle metabolism using hyperpolarized 13C magnetic resonance spectroscopy.

    Science.gov (United States)

    Schroeder, Marie A; Atherton, Helen J; Ball, Daniel R; Cole, Mark A; Heather, Lisa C; Griffin, Julian L; Clarke, Kieran; Radda, George K; Tyler, Damian J

    2009-08-01

    The Krebs cycle plays a fundamental role in cardiac energy production and is often implicated in the energetic imbalance characteristic of heart disease. In this study, we measured Krebs cycle flux in real time in perfused rat hearts using hyperpolarized magnetic resonance spectroscopy (MRS). [2-(13)C]Pyruvate was hyperpolarized and infused into isolated perfused hearts in both healthy and postischemic metabolic states. We followed the enzymatic conversion of pyruvate to lactate, acetylcarnitine, citrate, and glutamate with 1 s temporal resolution. The appearance of (13)C-labeled glutamate was delayed compared with that of other metabolites, indicating that Krebs cycle flux can be measured directly. The production of (13)C-labeled citrate and glutamate was decreased postischemia, as opposed to lactate, which was significantly elevated. These results showed that the control and fluxes of the Krebs cycle in heart disease can be studied using hyperpolarized [2-(13)C]pyruvate.

  10. Operational electrochemical stability of thiophene-thiazole copolymers probed by resonant Raman spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Wade, Jessica; Wood, Sebastian; Kim, Ji-Seon, E-mail: ji-seon.kim@imperial.ac.uk [Department of Physics and Centre for Plastic Electronics, Imperial College London, London SW7 2AZ (United Kingdom); Beatrup, Daniel; Hurhangee, Michael; McCulloch, Iain; Durrant, James R. [Department of Chemistry and Centre for Plastic Electronics, Imperial College London, London SW7 2AY (United Kingdom); Bronstein, Hugo [Department of Chemistry and Centre for Plastic Electronics, Imperial College London, London SW7 2AY (United Kingdom); Department of Chemistry, University College London, London WC1H 0AJ (United Kingdom)

    2015-06-28

    We report on the electrochemical stability of hole polarons in three conjugated polymers probed by resonant Raman spectroscopy. The materials considered are all isostructural to poly(3-hexyl)thiophene, where thiazole units have been included to systematically deepen the energy level of the highest occupied molecular orbital (HOMO). We demonstrate that increasing the thiazole content planarizes the main conjugated backbone of the polymer and improves the electrochemical stability in the ground state. However, these more planar thiazole containing polymers are increasingly susceptible to electrochemical degradation in the polaronic excited state. We identify the degradation mechanism, which targets the C=N bond in the thiazole units and results in disruption of the main polymer backbone conjugation. The introduction of thiazole units to deepen the HOMO energy level and increase the conjugated backbone planarity can be beneficial for the performance of certain optoelectronic devices, but the reduced electrochemical stability of the hole polaron may compromise their operational stability.

  11. Conformational Structure of Tyrosine, Tyrosyl-Glycine, and Tyrosyl-Glycyl-Glycine by Double Resonance Spectroscopy

    Science.gov (United States)

    Abo-Riziq, Ali; Grace, Louis; Crews, Bridgit; Callahan, Michael P,; van Mourik, Tanja; de Vries, Mattanjah S,

    2011-01-01

    We investigated the variation in conformation for the amino acid tyrosine (Y), alone and in the small peptides tyrosine-glycine (YC) and tyrosine-glycine-glycine (YGG), in the gas phase by using UV-UV and IR-UV double resonance spectroscopy and density functional theory calculations. For tyrosine we found seven different conformations, for YG we found four different conformations, and for YGG we found three different conformations. As the peptides get larger, we observe fewer stable conformers, despite the increasing complexity and number of degrees of freedom. We find structural trends similar to those in phenylalanine-glycine glycine (FGG) and tryptophan-glycine-glycine (WGG)j however) the effect of dispersive forces in FGG for stabilizing a folded structure is replaced by that of hydrogen bonding in YGG.

  12. Optimization of metabolite detection by quantum mechanics simulations in magnetic resonance spectroscopy.

    Science.gov (United States)

    Gambarota, Giulio

    2017-07-15

    Magnetic resonance spectroscopy (MRS) is a well established modality for investigating tissue metabolism in vivo. In recent years, many efforts by the scientific community have been directed towards the improvement of metabolite detection and quantitation. Quantum mechanics simulations allow for investigations of the MR signal behaviour of metabolites; thus, they provide an essential tool in the optimization of metabolite detection. In this review, we will examine quantum mechanics simulations based on the density matrix formalism. The density matrix was introduced by von Neumann in 1927 to take into account statistical effects within the theory of quantum mechanics. We will discuss the main steps of the density matrix simulation of an arbitrary spin system and show some examples for the strongly coupled two spin system. Copyright © 2016 Elsevier Inc. All rights reserved.

  13. High resolution collinear resonance ionization spectroscopy of neutron-rich $^{76,77,78}$Cu isotopes

    CERN Document Server

    AUTHOR|(CDS)2083035

    In this work, nuclear magnetic dipole moments, electric quadrupole moments, nuclear spins and changes in the mean-squared charge radii of radioactive copper isotopes are presented. Reaching up to $^{78}$Cu ($Z=29$, $N=49$), produced at rates of only 10 particles per second, these measurements represent the most exotic laser spectroscopic investigations near the doubly-magic and very exotic $^{78}$Ni ($Z=28$,$N=50$) to date. This thesis outlines the technical developments and investigations of laser-atom interactions that were performed during this thesis. These developments were crucial for establishing a high-resolution, high sensitivity collinear resonance ionization spectroscopy experiment at ISOLDE, CERN. This thesis furthermore provides a detailed description of the analysis tools that were implemented and applied to extract the nuclear observables from the experimental data. The results were compared to several large-scale shell model calculations, and provide deep insight into the structure of $^{78}$N...

  14. Proton magnetic resonance spectroscopy reflects metabolic decompensation in maple syrup urine disease

    Energy Technology Data Exchange (ETDEWEB)

    Heindel, W. [Dept. of Diagnostic Radiology, Univ. Koeln (Germany); Kugel, H. [Dept. of Diagnostic Radiology, Univ. Koeln (Germany); Wendel, U. [Children`s Hospital, Univ. Duesseldorf (Germany); Roth, B. [Children`s Hospital, Univ. Koeln (Germany); Benz-Bohm, G. [Dept. of Diagnostic Radiology, Univ. Koeln (Germany)

    1995-06-01

    Using localized proton magnetic resonance spectroscopy ({sup 1}H-MRS), accumulation of branchedchain amino acids (BCAA) and their corresponding 2-oxo acids (BCOA) could be non-invasively demonstrated in the brain of a 9-year-old girl suffering from classical maple syrup urine disease. During acute metabolic decompensation, the compounds caused a signal at a chemical shift of 0.9 ppm which was assigned by in vitro experiments. The brain tissue concentration of the sum of BCAA and BCOA could be estimated as 0.9 mmol/l. Localized {sup 1}H-MRS of the brain appears to be suitable for examining patients suffering from maple syrup urine disease in different metabolic states. (orig.)

  15. Proton Magnetic Resonance Spectroscopy: Relevance of Glutamate and GABA to Neuropsychology.

    Science.gov (United States)

    Ende, Gabriele

    2015-09-01

    Proton Magnetic Resonance Spectroscopy (MRS) has been widely used to study the healthy and diseased brain in vivo. The availability of whole body MR scanners with a field strength of 3 Tesla and above permit the quantification of many metabolites including the neurotransmitters glutamate (Glu) and γ-aminobutyric acid (GABA). The potential link between neurometabolites identified by MRS and cognition and behavior has been explored in numerous studies both in healthy subjects and in patient populations. Preliminary findings suggest direct or opposite associations between GABA or Glu with impulsivity, anxiety, and dexterity. This chapter is intended to provide an overview of basic principles of MRS and the literature reporting correlations between GABA or Glu and results of neuropsychological assessments.

  16. Magnetic Resonance Spectroscopy for Detection of 2-Hydroxyglutarate as a Biomarker for IDH Mutation in Gliomas

    Science.gov (United States)

    Leather, Thomas; Jenkinson, Michael D.; Das, Kumar; Poptani, Harish

    2017-01-01

    Mutations in the isocitrate dehydrogenase (IDH)1/2 genes are highly prevalent in gliomas and have been suggested to play an important role in the development and progression of the disease. Tumours harbouring these mutations exhibit a significant alteration in their metabolism resulting in the aberrant accumulation of the oncometabolite 2-hydroxygluarate (2-HG). As well as being suggested to play an important role in tumour progression, 2-HG may serve as a surrogate indicator of IDH status through non-invasive detection using magnetic resonance spectroscopy (MRS). In this review, we describe the recent efforts in developing MRS methods for detection and quantification of 2-HG in vivo and provide an assessment of the role of the 2-HG in gliomagenesis and patient prognosis. PMID:28629182

  17. In vivo Magnetic Resonance Spectroscopy of cerebral glycogen metabolism in animals and humans.

    Science.gov (United States)

    Khowaja, Ameer; Choi, In-Young; Seaquist, Elizabeth R; Öz, Gülin

    2015-02-01

    Glycogen serves as an important energy reservoir in the human body. Despite the abundance of glycogen in the liver and skeletal muscles, its concentration in the brain is relatively low, hence its significance has been questioned. A major challenge in studying brain glycogen metabolism has been the lack of availability of non-invasive techniques for quantification of brain glycogen in vivo. Invasive methods for brain glycogen quantification such as post mortem extraction following high energy microwave irradiation are not applicable in the human brain. With the advent of (13)C Magnetic Resonance Spectroscopy (MRS), it has been possible to measure brain glycogen concentrations and turnover in physiological conditions, as well as under the influence of stressors such as hypoglycemia and visual stimulation. This review presents an overview of the principles of the (13)C MRS methodology and its applications in both animals and humans to further our understanding of glycogen metabolism under normal physiological and pathophysiological conditions such as hypoglycemia unawareness.

  18. Nonlinear Resonant Ultrasound Spectroscopy (NRUS) Applied to Damage Assessment in Bone

    Science.gov (United States)

    Muller, M.; Tencate, J. A.; Darling, T. W.; Sutin, A.; Guyer, R. A.; Talmant, M.; Laugier, P.; Johnson, P. A.

    2006-05-01

    This study shows for the first time the feasibility of Nonlinear Resonant Ultrasound Spectroscopy (NRUS) techniques for damage characterization in bone. Two diaphysis of bovine bone were subjected to a progressive damage experiment. Fatigue damage was progressively induced in the samples by mechanical testing in 11 steps. At each damage step, the nonlinear elastic parameter was measured using NRUS. For independent assessment of damage, high energy X-ray CT imaging was performed, but only helped in the detection of the prominent cracks. As the amount of damage accumulation increased, a corresponding increase in the nonlinear response was observed. The measured nonlinear response is much more sensitive than the change in modulus. The results suggest that NRUS could be a potential tool for micro-damage assessment in bone. Further work has to be carried out for a better understanding of the physical nature of damaged bone, and for the ultimate goal of in vivo implementation of the technique.

  19. Detectability of Neuronal Currents in Human Brain with Magnetic Resonance Spectroscopy.

    Energy Technology Data Exchange (ETDEWEB)

    Jones, Howland D. T. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Thomas, Edward V. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Harper, Jason C. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Mayer, Andrew R. [Mind Research Network, Albuquerque, NM (United States); Univ. of New Mexico, Albuquerque, NM (United States); Caprihan, Arvind [Mind Research Network, Albuquerque, NM (United States); Gasparovic, Charles [Mind Research Network, Albuquerque, NM (United States); Univ. of New Mexico, Albuquerque, NM (United States); Blagoev, Krastan B. [Mind Research Network, Albuquerque, NM (United States); Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Haaland, David M. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2012-09-01

    Magnetic resonance spectroscopy has been used in a high-risk, high-payoff search for neuronal current (NC) signals in the free induction decay (FID) data from the visual cortex of human subjects during visual stimulation. If successful, this approach could make possible the detection of neuronal currents in the brain at high spatial and temporal resolution. Our initial experiments indicated the presence of a statistically significant change in the FID containing the NC relative to FIDs with the NC absent, and this signal was consistent with the presence of NC. Unfortunately, two follow-on experiments were not able to confirm or replicate the positive findings of the first experiment. However, even if the result from the first experiment were evidence of NC in the FID, it is clear that its effect is so small, that a true NC imaging experiment would not be possible with the current instrumentation and experimental protocol used here.

  20. Adults with attention-deficit/hyperactivity disorder - a brain magnetic resonance spectroscopy study

    DEFF Research Database (Denmark)

    Dramsdahl, Margaretha; Ersland, Lars; Plessen, Kerstin J

    2011-01-01

    Background: Impaired cognitive control in individuals with attention-deficit/hyperactivity disorder (ADHD) may be related to a prefrontal cortical glutamatergic deficit. We assessed the glutamate level in the left and the right midfrontal region including the anterior cingulate cortex in adults...... with ADHD and healthy controls. Methods: Twenty-nine adults with ADHD and 38 healthy controls were included. We used Proton Magnetic Resonance Imaging with single voxel point-resolved spectroscopy to measure the ratio of glutamate to creatine (Glu/Cre) in the left and the right midfrontal region in the two...... groups. Results: The ADHD group showed a significant reduction of Glu/Cre in the left midfrontal region compared to the controls. Conclusion: The reduction of Glu/Cre in the left midfrontal region in the ADHD group may reflect a glutamatergic deficit in prefrontal neuronal circuitry in adults with ADHD...

  1. A CRITICAL REVIEW OF MAGNETIC RESONANCE SPECTROSCOPY STUDIES OF OBSESSIVE-COMPULSIVE DISORDER

    Science.gov (United States)

    Brennan, Brian P.; Rauch, Scott L.; Jensen, J. Eric; Pope, Harrison G.

    2012-01-01

    Functional neuroimaging studies have converged to suggest that cortico-striatal-thalamo-cortical (CSTC) circuit dysfunction is a core pathophysiolologic feature of obsessive-compulsive disorder (OCD). Now, complementary approaches examining regional neurochemistry are beginning to yield additional insights regarding the neurobiology of aberrant CSTC circuitry in OCD. In particular, proton magnetic resonance spectroscopy (1H-MRS), which allows for the in vivo quantification of various neurochemicals in the CSTC circuit and other brain regions, has recently been used extensively in studies of OCD patients. In this review, we summarize the diverse and often seemingly inconsistent findings of these studies, consider methodological factors that may help to explain these inconsistencies, and discuss several convergent findings that tentatively appear to be emerging. We conclude with suggestions for possible future 1H-MRS studies in OCD. PMID:22831979

  2. Frequency-comb-referenced singly-resonant OPO for sub-Doppler spectroscopy.

    Science.gov (United States)

    Ricciardi, I; De Tommasi, E; Maddaloni, P; Mosca, S; Rocco, A; Zondy, J-J; De Rosa, M; De Natale, P

    2012-04-09

    We present a widely-tunable, singly-resonant optical parametric oscillator, emitting more than 1 W between 2.7 and 4.2 μm, which is phase locked to a self-referenced frequency comb. Both pump and signal frequencies are directly phase-locked to the frequency comb of a NIR-emitting fs mode-locked fibre laser, linked, in turn, to the caesium primary standard. We estimate for the idler frequency a fractional Allan deviation of ∼ 3 × 10⁻¹²τ⁻½ between 1 and 200 s. To test the spectroscopic performance of the OPO, we carried out saturation spectroscopy of several transitions belonging to the ν1 rovibrational band of CH₃I, resolving their electronic quadrupole hyperfine structure, estimating a linewidth better than 200 kHz FWHM for the idler, and determining the absolute frequency of the hyperfine components with a 50-kHz-uncertainty.

  3. Cavity ring-up spectroscopy for dissipative and dispersive sensing in a whispering gallery mode resonator

    CERN Document Server

    Yang, Yong; Kasumie, Sho; Ward, Jonathan M; Chormaic, Síle Nic

    2016-01-01

    In whispering gallery mode resonator sensing applications, the conventional way to detect a change in the parameter to be measured is by observing the steady state transmission spectrum through the coupling waveguide. Alternatively, cavity ring-up spectroscopy (CRUS) sensing can be achieved transiently. In this work, we investigate CRUS using coupled mode equations and find analytical solutions with a large spectral broadening approximation of the input pulse. The relationships between the frequency detuning, coupling gap and ring-up peak height are determined and experimentally verified using an ultrahigh \\textit{Q}-factor silica microsphere. This work shows that distinctive dispersive and dissipative transient sensing can be realised by simply measuring the peak height of the CRUS signal, which might improve the data collection rate.

  4. Can magnetic resonance spectroscopy differentiate malignant and benign causes of lymphadenopathy? An in-vitro approach.

    Science.gov (United States)

    Buré, Lionel; Boucher, Louis-Martin; Blumenkrantz, Miriam; Schob, Stefan; Lafaye de Micheaux, Pierre; Reinhold, Caroline; Gallix, Benoit

    2017-01-01

    Lymphadenopathy continues to be a common problem to radiologists and treating physicians because of the difficulty in confidently categorizing a node as being benign or malignant using standard diagnostic techniques. The goal of our research was to assess whether magnetic resonance (MR) spectroscopy contains the necessary information to allow differentiation of benign from malignant lymph nodes in an in-vitro approach using a modern pattern recognition method. Tissue samples from a tissue bank were analyzed on a nuclear magnetic resonance (NMR) spectrometer. A total of 69 samples were studied. The samples included a wide variety of malignant and benign etiologies. Using 45 samples, we initially created a model which was able to predict if a certain spectrum originates from benign or malignant lymph nodes using a pattern-recognition technique which takes into account the entire magnetic spectrum rather than single peaks alone. The remaining 24 samples were blindly loaded in the model to assess its performance. We obtained an excellent accuracy in differentiating benign and malignant lymphadenopathy using the model. It correctly differentiated as malignant or benign, in a blinded fashion, all of the malignant samples (13 of 13) and 10 out of the 11 benign samples. We thus showed that magnetic spectroscopy is able to differentiate benign from malignant causes of lymphadenopathy. Additional experiments were performed to verify that the differentiating abilities of our model were not due to differential tissue decay in between benign and malignant tissues. If future experiments demonstrate that a similar approach could be executed with standard MR imaging, this technique could be useful as a problem-solving tool when assessing lymphadenopathy in general. Alternatively, our in-vitro technique could also be useful to pathologists faced with indeterminate pathologies of the lymph nodes after validating our results with a larger sample size.

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

    DEFF Research Database (Denmark)

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

    1988-01-01

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

  6. Quantitative magnetic resonance spectroscopy in the entire human cervical spinal cord and beyond at 3T.

    Science.gov (United States)

    Henning, Anke; Schär, Michael; Kollias, Spyros S; Boesiger, Peter; Dydak, Ulrike

    2008-06-01

    Quantitative magnetic resonance spectroscopy (MRS) amends differential diagnostics of neurological pathology. However, due to technical challenges, it has rarely been applied to the spinal cord and has mainly been restricted to the very upper part of the cervical spine. In this work, an improved acquisition protocol is proposed that takes technical problems as strong magnetic field inhomogeneities, pulsatile flow of the cerebrospinal fluid (CSF), and small voxel size into account. For that purpose, inner-volume saturated point-resolved spectroscopy sequence (PRESS) localization, ECG triggering, and localized higher-order shimming and F0 determination, based on high-resolution cardiac-triggered static magnetic field B0 mapping, are combined. For inner-volume saturation a highly selective T1- and B1-insensitive outer-volume suppression (OVS) sequence based on broadband RF pulses with polynomial-phase response (PPR) is used. Validation is performed in healthy volunteers and patients with multiple sclerosis and intramedullary tumors. The applicability of spinal cord MRS is extended to the entire cervical spine. Spectral quality and its consistency are improved. In addition, high quality MRS patient data from a lesion that occluded the spinal canal in the thoracic spinal cord could be acquired. A quantitative analysis of patient spectra and spectra from healthy volunteers at different positions along the spinal cord underlines the diagnostic value of spinal cord MRS. Copyright (c) 2008 Wiley-Liss, Inc.

  7. Double resonance spectroscopy of different conformers of the neurotransmitter amphetamine and its clusters with water

    Energy Technology Data Exchange (ETDEWEB)

    Brause, R. [Institut fuer Physikalische Chemie, Heinrich-Heine-Universitaet, Universitaetsstrasse 1, D-40225 Duesseldorf (Germany); Fricke, H. [Institut fuer Physikalische Chemie, Heinrich-Heine-Universitaet, Universitaetsstrasse 1, D-40225 Duesseldorf (Germany); Gerhards, M. [Institut fuer Physikalische Chemie, Heinrich-Heine-Universitaet, Universitaetsstrasse 1, D-40225 Duesseldorf (Germany); Weinkauf, R. [Institut fuer Physikalische Chemie, Heinrich-Heine-Universitaet, Universitaetsstrasse 1, D-40225 Duesseldorf (Germany); Kleinermanns, K. [Institut fuer Physikalische Chemie, Heinrich-Heine-Universitaet, Universitaetsstrasse 1, D-40225 Duesseldorf (Germany)], E-mail: kleinermanns@uni-duesseldorf.de

    2006-08-21

    In this paper the conformational landscape of amphetamine in the neutral ground state is examined by both spectroscopy and theory. Several spectroscopic methods are used: laser-induced fluorescence (LIF), resonance-enhanced two-photon ionization (R2PI), dispersed fluorescence and IR/R2PI hole burning spectroscopy. The latter two methods provide for the first time vibrationally resolved spectra of the neutral ground state of dl-amphetamine and the amphetamine-(H{sub 2}O){sub 1,2} complexes. Nine stable conformers of the monomer were found by DFT (B3LYP/6-311++G(d,p)) and ab initio (MP2/6-311++G(d,p)) calculations. For conformer analysis the vibrations observed in the IR/R2PI hole burning and dispersed fluorescence spectra obtained from single vibronic levels (SVLF) of a selected conformer were compared with the results of an ab initio normal mode analysis. By this procedure three S{sub 0} {sup {yields}} S{sub 1} transitions in the R2PI spectrum were assigned to three different conformer structures. Another weak transition earlier attributed to another conformer could be assigned to a vibronic band of one of the three conformers. Furthermore spectra of amphetamine-(H{sub 2}O){sub 1,2} are tentatively assigned.

  8. Clinical perspectives of hybrid proton-fluorine magnetic resonance imaging and spectroscopy.

    Science.gov (United States)

    Wolters, Martijn; Mohades, Seyede G; Hackeng, Tilman M; Post, Mark J; Kooi, Marianne E; Backes, Walter H

    2013-05-01

    The number of applications of fluorine 19 (19F) magnetic resonance (MR) imaging and spectroscopy in biomedical and clinical research is steadily growing. The 100% natural abundance of fluorine and its relatively high sensitivity for MR (83% to that of protons) make it an interesting nucleus for a wide range of MR applications. Fluorinated contrast media have a number of advantages over the conventionally used gadolinium-based or iron-based contrast agents. The absence of an endogenous fluorine background intensity in the human body facilitates reliable quantification of fluorinated contrast medium or drugs. Anatomy can be visualized separately with proton MR imaging, creating the application of hybrid hydrogen 1 (1H)/19F MR imaging. The availability of 2 channels (ie, the 1H and 19F channels) enables dual-targeted molecular imaging. Recently, novel developments have emerged on fluorine-based contrast media in preclinical studies and imaging techniques. The developments in fluorine MR seem promising for clinical applications, with contributions in therapy monitoring, assessment of lung function, angiography, and molecular imaging. This review outlines the translation from recent advances in preclinical MR imaging and spectroscopy to future perspectives of clinical hybrid 1H/19/F MR imaging applications.

  9. Dynamics of asymmetric binary glass formers. II. Results from nuclear magnetic resonance spectroscopy.

    Science.gov (United States)

    Bock, D; Kahlau, R; Pötzschner, B; Körber, T; Wagner, E; Rössler, E A

    2014-03-07

    Various (2)H and (31)P nuclear magnetic resonance (NMR) spectroscopy techniques are applied to probe the component dynamics of the binary glass former tripropyl phosphate (TPP)/polystyrene-d3 (PS) over the full concentration range. The results are quantitatively compared to those of a dielectric spectroscopy (DS) study on the same system previously published [R. Kahlau, D. Bock, B. Schmidtke, and E. A. Rössler, J. Chem. Phys. 140, 044509 (2014)]. While the PS dynamics does not significantly change in the mixtures compared to that of neat PS, two fractions of TPP molecules are identified, one joining the glass transition of PS in the mixture (α1-process), the second reorienting isotropically (α2-process) even in the rigid matrix of PS, although at low concentration resembling a secondary process regarding its manifestation in the DS spectra. Pronounced dynamical heterogeneities are found for the TPP α2-process, showing up in extremely stretched, quasi-logarithmic stimulated echo decays. While the time window of NMR is insufficient for recording the full correlation functions, DS results, covering a larger dynamical range, provide a satisfactory interpolation of the NMR data. Two-dimensional (31)P NMR spectra prove exchange within the broadly distributed α2-process. As demonstrated by (2)H NMR, the PS matrix reflects the faster α2-process of TPP by performing a spatially highly hindered motion on the same timescale.

  10. A Nested Phosphorus and Proton Coil Array for Brain Magnetic Resonance Imaging and Spectroscopy

    Science.gov (United States)

    Brown, Ryan; Lakshmanan, Karthik; Madelin, Guillaume; Parasoglou, Prodromos

    2015-01-01

    A dual-nuclei radiofrequency coil array was constructed for phosphorus and proton magnetic resonance imaging and spectroscopy of the human brain at 7 Tesla. An eight-channel transceive degenerate birdcage phosphorus module was implemented to provide whole-brain coverage and significant sensitivity improvement over a standard dual-tuned loop coil. A nested eight-channel proton module provided adequate sensitivity for anatomical localization without substantially sacrificing performance on the phosphorus module. The developed array enabled phosphorus spectroscopy, a saturation transfer technique to calculate the global creatine kinase forward reaction rate, and single-metabolite whole-brain imaging with 1.4 cm nominal isotropic resolution in 15 min (2.3 cm actual resolution), while additionally enabling 1 mm isotropic proton imaging. This study demonstrates that a multi-channel array can be utilized for phosphorus and proton applications with improved coverage and/or sensitivity over traditional single-channel coils. The efficient multi-channel coil array, time-efficient pulse sequences, and the enhanced signal strength available at ultra-high fields can be combined to allow volumetric assessment of the brain and could provide new insights into the underlying energy metabolism impairment in several neurodegenerative conditions, such as Alzheimer’s and Parkinson’s diseases, as well as mental disorders such as schizophrenia. PMID:26375209

  11. Accelerated 2D magnetic resonance spectroscopy of single spins using matrix completion

    Science.gov (United States)

    Scheuer, Jochen; Stark, Alexander; Kost, Matthias; Plenio, Martin B.; Naydenov, Boris; Jelezko, Fedor

    2015-12-01

    Two dimensional nuclear magnetic resonance (NMR) spectroscopy is one of the major tools for analysing the chemical structure of organic molecules and proteins. Despite its power, this technique requires long measurement times, which, particularly in the recently emerging diamond based single molecule NMR, limits its application to stable samples. Here we demonstrate a method which allows to obtain the spectrum by collecting only a small fraction of the experimental data. Our method is based on matrix completion which can recover the full spectral information from randomly sampled data points. We confirm experimentally the applicability of this technique by performing two dimensional electron spin echo envelope modulation (ESEEM) experiments on a two spin system consisting of a single nitrogen vacancy (NV) centre in diamond coupled to a single 13C nuclear spin. The signal to noise ratio of the recovered 2D spectrum is compared to the Fourier transform of randomly subsampled data, where we observe a strong suppression of the noise when the matrix completion algorithm is applied. We show that the peaks in the spectrum can be obtained with only 10% of the total number of the data points. We believe that our results reported here can find an application in all types of two dimensional spectroscopy, as long as the measured matrices have a low rank.

  12. Quantitative Determination and Validation of Metformin Hydrochloride in Pharmaceutical Using Quantitative Nuclear Magnetic Resonance Spectroscopy

    Directory of Open Access Journals (Sweden)

    H. H. Gadape

    2011-01-01

    Full Text Available Rapid, specific and accurate proton nuclear magnetic resonance spectroscopy (1H NMR method was developed to determine metformin hydrochloride antidiabetic drug in pharmaceutical tablet formulation. The method was based on quantitative NMR spectroscopy (qNMR using maleic acid as an internal standard and deuterium oxide (D2O as a diluent. For the quantification of the drug, the (1H NMR signals at 2.91 ppm and 6.25 ppm corresponding to the analyte proton of metformin hydrochloride and maleic acid internal reference standard (IS respectively were used. The method was validated for the parameters of specificity and selectivity, precision and intermediate precision, linearity, range, limit of detection (LOD and limit of quantification (LOQ, accuracy, solution stability and robustness. The linearity of the calibration curve for analyte in the desired concentration range was good (R2=0.9993. The method was accurate and precise with good recoveries. Range study was also performed up to saturation level (152.67 mg/0.60 mL in D2O. The advantage of the method is that no reference standard of analyte drug is required for quantification. The method is nondestructive and can be applied for quantification of metformin hydrochloride in commercial formulation products.

  13. Electron spin resonance spectroscopy of high purity crystals at millikelvin temperatures

    Science.gov (United States)

    Farr, Warrick G.; Creedon, Daniel L.; Goryachev, Maxim; Benmessai, Karim; Tobar, Michael E.

    2013-12-01

    Progress in the emerging field of engineered quantum systems requires the development of devices that can act as quantum memories. The realisation of such devices by doping solid state cavities with paramagnetic ions imposes a trade-off between ion concentration and cavity coherence time. Here, we investigate an alternative approach involving interactions between photons and naturally occurring impurity ions in ultra-pure crystalline microwave cavities exhibiting exceptionally high quality factors. We implement a hybrid Whispering Gallery/Electron Spin Resonance method to perform rigorous spectroscopy of an undoped single-crystal sapphire resonator over the frequency range 8{19 GHz, and at external applied DC magnetic fields up to 0.9 T. Measurements of a high purity sapphire cooled close to 100 mK reveal the presence of Fe3+, Cr3+, and V2+ impurities. A host of electron transitions are measured and identified, including the two-photon classically forbidden quadrupole transition (Δms = 2) for Fe3+, as well as hyperfine transitions of V2+.

  14. Resonance ionization spectroscopy of Europium The first application of the PISA at ISOLDE-RILIS

    CERN Document Server

    AUTHOR|(CDS)2099873; Marsh, Bruce Alan

    The following work has been carried out at the radioactive ion beam facility ISOLDE at CERN. A compact atomic beam unit named PISA (Photo Ionization Spectroscopy Apparatus) has been implemented as a recent addition to the laboratory of the Resonance Ionization Laser Ion Source (RILIS). The scope of this thesis work was to demonstrate different applications of the PISA, using the existing and highly developed laser setup of the RILIS installation. In a demonstration of the suitability of PISA for ionization scheme development, a new ionization scheme for Europium has been developed. This resulted in the observation of several new autoionizing states and Rydberg series. Through the analysis of the observed Rydberg resonances a refined value of $45734.33(3)(3)$ cm$^{-1}$ for the ionization potential of the europium atom has been determined. In addition this thesis reports on the feasibility of the use of the PISA as a RILIS performance monitoring device during laser ion source operations. Finally the present wor...

  15. Tuberculoma of the brain - A diagnostic dilemma: Magnetic resonance spectroscopy a new ray of hope

    Directory of Open Access Journals (Sweden)

    Subhasis Mukherjee

    2015-01-01

    Full Text Available Tuberculoma of the brain is an important clinical entity. The main challenge in the management of brain tuberculoma is its diagnosis. Appearance in computed tomography (CT scan of brain is common and consists of solitary or multiple ring-enhancing lesions with moderate perilesional edema, but these are not specific for tuberculoma as neurocysticercosis (NCC, coccidiomycosis, toxoplasmosis, metastasis and few other diseases may also have similar appearance on CT scan brain. Cerebrospinal fluid examination is often normal and biopsy and tissue culture from the lesion though the diagnosis of choice is technically too demanding and not feasible in most of the times. All these put the clinicians in a great dilemma as regard to a confidant diagnosis of tuberculoma of the brain. With advancement of imaging techniques, magnetic resonance imaging (MRI of brain with magnetic resonance spectroscopy (MRS has shown a great hope in this context as MRS shows a specific lipid peak in cases of tuberculoma which is not seen in any other differential diagnoses of tuberculoma. This review article is written to have an overview regarding the current diagnostic approach for brain tuberculoma with special emphasis on the role of MRS. Extensive literature review of the articles published in English was conducted using Google search, Google Scholar, PubMed and Medline using the keywords such as ring-enhancing lesions, etiology, tuberculoma, NCC, CT scan brain, MRI, MRS, images.

  16. Magnetic resonance spectroscopy for assessment of brain injury in the rat model of sepsis.

    Science.gov (United States)

    Wen, Miaoyun; Lian, Zhesi; Huang, Linqiang; Zhu, Senzhi; Hu, Bei; Han, Yongli; Deng, Yiyu; Zeng, Hongke

    2017-11-01

    The diagnostic value of magnetic resonance spectroscopy (MRS), T2-weighted imaging (T2WI) and serum markers of brain injury in a rat model of sepsis were investigated. Rats were randomly divided into the control group and 6, 12 and 24 h after lipopolysaccharide-injection groups. Brain morphology and metabolism were assessed with T2WI magnetic resonance imaging (MRI) and MRS. Serum and brain tissue samples were then collected to examine the concentrations of neuron-specific enolase (NSE) and S100-β protein. Brain T2WI showed no differences between the groups. N-acetylaspartate/choline (NAA/Cr) ratio measured by MRS showed different degrees of decrease in the sepsis groups, and serum NSE and S100-β concentrations were increased compared with the control group. Apoptosis rates were measured in the right hippocampal area, and there were statistically significant differences between the indicated groups and the control group (p<0.05). The correlation between apoptosis rate and NAA/Cr ratio was closer than that between apoptosis rate and NSE or S100-β (-0.925 vs. 0.434 vs. 0.517, respectively). In conclusion, MRS is a sensitive, non-invasive method to investigate complications of brain injury in septic rats, which may be utilized for the early diagnosis of brain injury caused by sepsis.

  17. Probing rotational relaxation in HBr (v=1) using double resonance spectroscopy.

    Science.gov (United States)

    Kabir, Md Humayun; Antonov, Ivan O; Heaven, Michael C

    2009-02-21

    Rotational energy transfer in HBr(v=1)+HBr collisions has been investigated using an optical pump-probe double resonance technique at ambient temperature. Rotationally state selective excitation of v=1 for rotational levels in the range J=0-9 was achieved by stimulated Raman pumping, and the evolution of population was monitored using (2+1) resonantly enhanced multiphoton ionization spectroscopy of the g (3) summation (-)-X (1) summation (+)(0-1) band. Collision-induced population transfer events with DeltaJ

  18. Bayesian normal modes identification and estimation of elastic coefficients in resonant ultrasound spectroscopy

    Science.gov (United States)

    Bernard, Simon; Marrelec, Guillaume; Laugier, Pascal; Grimal, Quentin

    2015-06-01

    Resonant ultrasound spectroscopy is an experimental technique for measuring the stiffness of anisotropic solid materials. The free vibration resonant frequencies of a specimen are measured and the stiffness coefficients of the material adjusted to minimize the difference between experimental and predicted frequencies. An issue of this inverse approach is that the measured frequencies are not easily paired with their predicted counterpart, leading to ambiguities in the definition of the objective function. In the past, this issue has been overcome through trial-and-error methods requiring the experimentalist to find the correct pairing, or through involved experimental methods measuring the shapes of the normal vibration modes in addition to their frequencies. The purpose of this work is to show, through a Bayesian formulation, that the inverse problem can be solved automatically and without requiring additions to the usual experimental setup. The pairing of measured and predicted frequencies is considered unknown, and the joint posterior probability distribution of pairing and stiffness is sampled using Markov chain Monte Carlo. The method is illustrated on two published data sets. The first set includes the exact pairing, allowing validation of the method. The second application deals with attenuative materials, for which many predicted modes cannot be observed, further complicating the inverse problem. In that case, introduction of prior information through Bayesian formulation reduces ambiguities.

  19. Shifted excitation resonance Raman difference spectroscopy using a microsystem light source at 488 nm

    Science.gov (United States)

    Maiwald, M.; Sowoidnich, K.; Schmidt, H.; Sumpf, B.; Erbert, G.; Kronfeldt, H.-D.

    2010-04-01

    Experimental results in shifted excitation resonance Raman difference spectroscopy (SERRDS) at 488 nm will be presented. A novel compact diode laser system was used as excitation light source. The device is based on a distributed feedback (DFB) diode laser as a pump light source and a nonlinear frequency doubling using a periodically poled lithium niobate (PPLN) waveguide crystal. All elements including micro-optics are fixed on a micro-optical bench with a footprint of 25 mm × 5 mm. An easy temperature management of the DFB laser and the crystal was used for wavelength tuning. The second harmonic generation (SHG) provides an additional suppression of the spontaneous emission. Raman spectra of polystyrene demonstrate that no laser bandpass filter is needed for the Raman experiments. Resonance-Raman spectra of the restricted food colorant Tartrazine (FD&C Yellow 5, E 102) in distilled water excited at 488 nm demonstrate the suitability of this light source for SERRDS. A limit of detection (LOD) of 0.4 μmol.l-1 of E102 enables SERRDS at 488 nm for trace detection in e.g. food safety control as an appropriate contactless spectroscopic technique.

  20. Correcting reaction rates measured by saturation-transfer magnetic resonance spectroscopy

    Science.gov (United States)

    Gabr, Refaat E.; Weiss, Robert G.; Bottomley, Paul A.

    2008-04-01

    Off-resonance or spillover irradiation and incomplete saturation can introduce significant errors in the estimates of chemical rate constants measured by saturation-transfer magnetic resonance spectroscopy (MRS). Existing methods of correction are effective only over a limited parameter range. Here, a general approach of numerically solving the Bloch-McConnell equations to calculate exchange rates, relaxation times and concentrations for the saturation-transfer experiment is investigated, but found to require more measurements and higher signal-to-noise ratios than in vivo studies can practically afford. As an alternative, correction formulae for the reaction rate are provided which account for the expected parameter ranges and limited measurements available in vivo. The correction term is a quadratic function of experimental measurements. In computer simulations, the new formulae showed negligible bias and reduced the maximum error in the rate constants by about 3-fold compared to traditional formulae, and the error scatter by about 4-fold, over a wide range of parameters for conventional saturation transfer employing progressive saturation, and for the four-angle saturation-transfer method applied to the creatine kinase (CK) reaction in the human heart at 1.5 T. In normal in vivo spectra affected by spillover, the correction increases the mean calculated forward CK reaction rate by 6-16% over traditional and prior correction formulae.

  1. Broadband multi-resonant strong field coherence breaking as a tool for single isomer microwave spectroscopy

    Science.gov (United States)

    Hernandez-Castillo, A. O.; Abeysekera, Chamara; Hays, Brian M.; Zwier, Timothy S.

    2016-09-01

    Using standard hardware available in chirped-pulse Fourier transform microwave (CP-FTMW) spectroscopy, an experimental method is introduced to selectively extract from the microwave spectrum of an otherwise complicated multicomponent mixture a set of transitions due to a single component, thereby speeding spectral assignment. The method operates the broadband chirped-pulse used to excite the sample in the strong-field limit through a combination of high power and control of the sweep rate. A procedure is introduced that leads to selection of three transition frequencies that can be incorporated as a set of resonant sequential single-frequency microwave pulses that follow broadband chirped-pulse excitation, resulting in a reduction in the coherent signal from a set of transitions ascribable to the component of interest. The difference in the CP-FTMW spectrum with and without this set of multi-resonant single-frequency pulses produces a set of transitions that can confidently be assigned to a single component of the mixture, aiding the analysis of its spectrum. The scheme is applied to (i) selectively extract the spectrum of one of five singly 13C-subsituted isotopologues of benzonitrile in natural abundance, (ii) obtain the microwave spectra of the two structural isomers (E)- and (Z)-phenylvinylnitrile, and (iii) obtain conformer-specific microwave spectra of methylbutyrate.

  2. Dynamics of asymmetric binary glass formers. I. A dielectric and nuclear magnetic resonance spectroscopy study.

    Science.gov (United States)

    Kahlau, R; Bock, D; Schmidtke, B; Rössler, E A

    2014-01-28

    Dielectric spectroscopy as well as (2)H and (31)P nuclear magnetic resonance spectroscopy (NMR) are applied to probe the component dynamics of the binary glass former tripropyl phosphate (TPP)/polystyrene (PS/PS-d3) in the full concentration (cTPP) range. In addition, depolarized light scattering and differential scanning calorimetry experiments are performed. Two glass transition temperatures are found: Tg 1(cTPP) reflects PS dynamics and shows a monotonic plasticizer effect, while the lower Tg 2(cTPP) exhibits a maximum and is attributed to (faster) TPP dynamics, occurring in a slowly moving or immobilized PS matrix. Dielectric spectroscopy probing solely TPP identifies two different time scales, which are attributed to two sub-ensembles. One of them, again, shows fast TPP dynamics (α2-process), the other (α1-process) displays time constants identical with those of the slow PS matrix. Upon heating the α1-fraction of TPP decreases until above some temperature Tc only a single α2-population exists. Inversely, below Tc a fraction of the TPP molecules is trapped by the PS matrix. At low cTPP the α2-relaxation does not follow frequency-temperature superposition (FTS), instead it is governed by a temperature independent distribution of activation energies leading to correlation times which follow Arrhenius laws, i.e., the α2-relaxation resembles a secondary process. Yet, (31)P NMR demonstrates that it involves isotropic reorientations of TPP molecules within a slowly moving or rigid matrix of PS. At high cTPP the super-Arrhenius temperature dependence of τ2(T), as well as FTS are recovered, known as typical of the glass transition in neat systems.

  3. Resonant inelastic scattering in dilute magnetic semiconductors by x-ray fluorescence spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Lawniczak-Jablonska, K. [Lawrence Berkeley National Lab., CA (United States)]|[Institute of Physics, Warsaw (Poland); Jia, J.J.; Underwood, J.H. [Lawrence Berkeley National Lab., CA (United States)] [and others

    1997-04-01

    As modern, technologically important materials have become more complex, element specific techniques have become invaluable in studying the electronic structure of individual components from the system. Soft x-ray fluorescence (SXF) and absorption (SXA) spectroscopies provide a unique means of measuring element and angular momentum density of electron states, respectively, for the valence and conducting bands in complex materials. X-ray absorption and the decay through x-ray emission are generally assumed to be two independent one-photon processes. Recent studies, however have demonstrated that SXF excited near the absorption threshold generate an array of spectral features that depend on nature of materials, particularly on the localization of excited states in s and d-band solids and that these two processes can no be longer treated as independent. Resonant SXF offers thus the new way to study the dynamics of the distribution of electronic valence states in the presence of a hole which is bound to the electron low lying in the conduction band. This process can simulate the interaction between hole-electron pair in wide gap semiconductors. Therefore such studies can help in understanding of transport and optics phenomena in the wide gap semiconductors. The authors report the result of Mn and S L-resonant emission in Zn{sub 1{minus}x}Mn{sub x}S (with x=0.2 and 0.3) and MnS as the energy of exciting radiation is tuned across the Mn and S L{sub 3,2} absorption edge, along with the resonant excited spectra from elemental Mn as a reference.

  4. In situ monitoring of polymer redox states by resonance µRaman spectroscopy and its applications in polymer modified microfluidic channels

    NARCIS (Netherlands)

    Logtenberg, Hella; Jellema, Laurens-Jan C.; Lopez-Martinez, Maria J.; Areephong, Jetsuda; Verpoorte, Elisabeth; Feringa, Ben L.; Browne, Wesley R.

    We report the application of multi-wavelength resonance Raman (rR) spectroscopy for the characterisation of vinyl-bridged polysexithiophene films formed by electropolymerisation on gold electrodes. Resonance Raman spectroscopy of the neutral, polaronic and bipolaronic states of the polymer were

  5. The prognostic value of proton magnetic resonance spectroscopy in term newborns treated with therapeutic hypothermia following asphyxia

    NARCIS (Netherlands)

    Sijens, Paul E.; Wischniowsky, Katharina; ter Horst, Hendrik J.

    2017-01-01

    Objective: The purpose of this study was to correlate brain metabolism assessed shortly after therapeutic hyperthermia by H-1 magnetic resonance spectroscopy (MRS), with neurodevelopmental outcome. Methods: At the age of 6.0 +/- 1.8 days, brain metabolites of 35 term asphyxiated newborns, treated

  6. Metabolic Profiling of Dividing Cells in Live Rodent Brain by Proton Magnetic Resonance Spectroscopy (1HMRS) and LCModel Analysis

    DEFF Research Database (Denmark)

    Park, June-Hee; Lee, Hedok; Makaryus, Rany

    2014-01-01

    RATIONALE: Dividing cells can be detected in the live brain by positron emission tomography or optical imaging. Here we apply proton magnetic resonance spectroscopy (1HMRS) and a widely used spectral fitting algorithm to characterize the effect of increased neurogenesis after electroconvulsive sh...

  7. Use of spin labels to study membrane proteins by high-frequency electron nuclear double resonance spectroscopy

    NARCIS (Netherlands)

    Orlinkskii, S.B.; Borovykh, I.V.; Zielke, V.; Steinhoff, H.J.

    2007-01-01

    The applicability of spin labels to study membrane proteins by high-frequency electron nuclear double resonance spectroscopy is demonstrated. With the use of bacteriorhodopsin embedded in a lipid membrane as an example, the spectra of protons of neighboring amino acids are recorded, electric field

  8. Direct assessment of hepatic mitochondrial oxidative and anaplerotic fluxes in humans using dynamic 13C magnetic resonance spectroscopy

    DEFF Research Database (Denmark)

    Befroy, Douglas E; Perry, Rachel J; Jain, Nimit

    2014-01-01

    Despite the central role of the liver in the regulation of glucose and lipid metabolism, there are currently no methods to directly assess hepatic oxidative metabolism in humans in vivo. By using a new (13)C-labeling strategy in combination with (13)C magnetic resonance spectroscopy, we show that...

  9. Coupling of column liquid chromatography and surface-enhanced resonance Raman spectroscopy via a thin-layer chromatographic plate.

    NARCIS (Netherlands)

    Coulter, S.K.; Gooijer, C.; Velthorst, N.H.; Brinkman, U.A.T.; Somsen, G.W.

    1997-01-01

    Surface-enhanced resonance Raman (SERR) spectroscopy was used to characterize compounds separated by column liquid chromatography (LC). Three percent of the effluent from a conventional-size LC column were immobilized on a moving thinlayer chromatography (TLC) plate using a spray-jet

  10. Surface-Enhanced Resonance Raman Scattering and Visible Extinction Spectroscopy of Copper Chlorophyllin: An Upper Level Chemistry Experiment

    Science.gov (United States)

    Schnitzer, Cheryl S.; Reim, Candace Lawson; Sirois, John J.; House, Paul G.

    2010-01-01

    Advanced chemistry students are introduced to surface-enhanced resonance Raman scattering (SERRS) by studying how sodium copper chlorophyllin (CuChl) adsorbs onto silver colloids (CuChl/Ag) as a function of pH. Using both SERRS and visible extinction spectroscopy, the extent of CuChl adsorption and colloidal aggregation are monitored. Initially at…

  11. Characterization of Al2O3-Supported Manganese Oxides by Electron Spin Resonance and Diffuse Reflectance Spectroscopy

    NARCIS (Netherlands)

    Kijlstra, W.S.; Poels, E.K.; Bliek, A.; Weckhuysen, B.M.; Schoonheydt, R.A.

    1996-01-01

    Alumina-supported manganese oxides, used as catalysts for the selective catalytic reduction of NO, were characterized by combined electron spin resonance and diffuse reflectance spectroscopies. Upon impregnation of the acetate precursor solution, the [Mn(H2O)6]^2+ complex interacts strongly with

  12. 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

  13. Mechanism of Exciplex Formation Between Cu-Porphyrin and Calf-thymus DNA as Revealed by Saturation Resonance Raman Spectroscopy

    NARCIS (Netherlands)

    Shvedko, A.G.; Kruglik, S.; Kruglik, S.G.; Ermolenkov, V.V.; Turpin, P.Y.; Greve, Jan; Otto, Cornelis

    1999-01-01

    The excited-state complex (exciplex) formation that results from the photoinduced interaction of water-soluble cationic copper(II) 5,10,15,20-tetrakis[4-(N-methylpyridyl)]porphyrin [Cu(TMpy-P4)] with calf-thymus DNA has been studied in detail by resonance Raman (RR) spectroscopy using both ~10 ns

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

    NARCIS (Netherlands)

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

    1991-01-01

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

  15. From raw data to data-analysis for magnetic resonance spectroscopy – the missing link: jMRUI2XML

    Czech Academy of Sciences Publication Activity Database

    Mocioiu, V.; Ortega-Martorell, S.; Olier, I.; Jablonski, Michal; Starčuková, Jana; Lisboa, P.; Arús, C.; Julia-Sapé, M.

    2015-01-01

    Roč. 16, NOV 9 (2015), s. 378-388 ISSN 1471-2105 R&D Projects: GA MŠk(CZ) LO1212; GA MŠk ED0017/01/01 Institutional support: RVO:68081731 Keywords : magnetic resonance spectroscopy * pattern recognition * signal processing, * software development Subject RIV: JC - Computer Hardware ; Software Impact factor: 2.435, year: 2015

  16. Roll control resonance test vehicle (RCRTV) system postflight evaluation report

    Energy Technology Data Exchange (ETDEWEB)

    Kryvoruka, J.K.

    1973-03-01

    This report presents the flight test results for a reentry vehicle spin-fin roll control system. The test vehicle, designated the Roll Control Resonance Test Vehicle, was flight tested on May 10, 1972, at the Sandia Laboratories Tonopah Test Range. The purpose of the flight were (1) to demonstrate and evaluate the capability of the control system to overcome a roll resonance flight instability and (2) to confirm the analytic predictions of system performance. The flight test vehicle had built-in asymmetries which, without roll control, would have caused a persistent roll resonance instability to occur. The test was successful in that all systems functioned properly and all program and flight test objectives were accomplished. Flight test data presented herein confirm analytic predictions and flight simulation methods. Results show that the system maintained roll rate control and prevented the roll resonance instability.

  17. Dielectric spectroscopy for evaluating dry matter content of potato tubers

    DEFF Research Database (Denmark)

    Gunner Brink Nielsen, Glenn; Kjær, Anders; Klösgen, Beate

    2016-01-01

    The present study investigated the application of dielectric spectroscopy as a method for evaluating the dry matter content of potato tubers. Sample specific factors determining the precision of this application were investigated by studying the prediction of the dry material content in agar gel ...

  18. Brain tumor evaluation and segmentation by in vivo proton spectroscopy and relaxometry.

    Science.gov (United States)

    Martín-Landrove, Miguel; Mayobre, Finita; Bautista, Igor; Villalta, Raúl

    2005-12-01

    A new methodology has been developed for the evaluation and segmentation of brain tumors using information obtained by different magnetic resonance techniques such as in vivo proton magnetic resonance spectroscopy (1HMRS) and relaxometry. In vivo 1HMRS may be used as a preoperative technique that allows noninvasive monitoring of metabolites to identify the different tissue types present in the lesion (active tumor, necrotic tissue, edema, and normal or non-affected tissue). Spatial resolution for treatment consideration may be improved by using 1HMRS combined or fused with images obtained by relaxometry which exhibit excellent spatial resolution. Some segmentation schemes are presented and discussed. The results show that segmentation performed in this way efficiently determines the spatial localization of the tumor both qualitatively and quantitatively. It provides appropriate information for therapy planning and application of therapies such as radiosurgery or radiotherapy and future control of patient evolution.

  19. Magnetic resonance evaluation of cerebral toxoplasmosis in patients with the acquired immunodeficiency syndrome

    Energy Technology Data Exchange (ETDEWEB)

    Batra, A; Tripathi, R.P.; Gorthi, S.P. [Inst. of Nuclear Medicine and Allied Sciences, Delhi (India). NMR Research Center

    2004-04-01

    PURPOSE: To evaluate and delineate the characteristics of cerebral toxoplasmosis lesions using a combination of magnetic resonance (MR) spectroscopy, diffusion, and perfusion studies. MATERIAL AND METHODS: A total of 8 patients with 23 lesions were evaluated on a 1.5-T MR system. Diffusion-weighted imaging (DWI) was performed with three 'b' values of 50, 500, and 1000 s/mm2, and the apparent diffusion coefficient maps were calculated. The diffusion-weighted appearances and the T2-weighted MR appearances of the lesions were compared. MR spectroscopy was performed using the point-resolved single-voxel technique with two TE values of 135 ms and 270 ms. Perfusion studies were carried out using the dynamic contrast-enhanced technique, and the relative cerebral blood volume maps were qualitatively and quantitatively analyzed. RESULTS: DWI revealed the majority of the lesions as having increased diffusion within their necrotic centers, with the ADC ranging from 0.5 to 3.01 (mean {+-} SD: 1.49 {+-} 0.7). All the lesions revealed a predominant lipid peak on MR spectroscopy and were extremely hypovascular on perfusion MR studies. CONCLUSION: MR diffusion, spectroscopy, and perfusion studies help in characterizing toxoplasmosis lesions and, in most cases, can be used in combination to help establish the diagnosis of toxoplasmosis.

  20. Static fluid magnetic resonance urography in evaluation of ureteral ...

    African Journals Online (AJOL)

    Introduction: Ectopic ureters are often very difficult to diagnose with conventional imaging modalities especially in children. Magnetic resonance urography (MRU) has been recently investigated as a problem-solving tool for the evaluation of various congenital urogenital anomalies with favorable results. Aim of the work: To ...

  1. Static fluid magnetic resonance urography in evaluation of ureteral ...

    African Journals Online (AJOL)

    T.Y. Gaweesh

    2012-09-06

    Sep 6, 2012 ... Abstract Introduction: Ectopic ureters are often very difficult to diagnose with conventional imag- ing modalities especially in children. Magnetic resonance urography (MRU) has been recently inves- tigated as a problem-solving tool for the evaluation of various congenital urogenital anomalies with favorable ...

  2. Theoretical evaluation of the electron paramagnetic resonance spin ...

    Indian Academy of Sciences (India)

    Theoretical evaluation of the electron paramagnetic resonance spin Hamiltonian parameters for the impurity displacements for Fe3+ and Ru3+ in corundum. Q FU1,SYWU1,2∗, J Z LIN1 and J S YAO1. 1Department of Applied Physics, University of Electronic Science and Technology of China, Chengdu 610054, People's ...

  3. FTIR difference and resonance Raman spectroscopy of rhodopsins with applications to optogenetics

    Science.gov (United States)

    Saint Clair, Erica C.

    The major aim of this thesis is to investigate the molecular basis for the function of several types of rhodopsins with special emphasis on their application to the new field of optogenetics. Rhodopsins are transmembrane biophotonic proteins with 7 alpha-helices and a retinal chromophore. Studies included Archaerhodopsin 3 (AR3), a light driven proton pump similar to the extensively studied bacteriorhodopsin (BR); channelrhodopsins 1 and 2, light-activated ion channels; sensory rhodopsin II (SRII), a light-sensing protein that modulates phototaxis used in archaebacteria; and squid rhodopsins (sRho), the major photopigment in squid vision and a model for human melanopsin, which controls circadian rhythms. The primary techniques used in these studies were FTIR difference spectroscopy and resonance Raman spectroscopy. These techniques, in combination with site directed mutagenesis and other biochemical methodologies produced new knowledge regarding the structural changes of the retinal chromophore, the location and function of internal water molecules as well as specific amino acids and peptide backbone. Specialized techniques were developed that allowed rhodopsins to be studied in intact membrane environments and in some cases in vivo measurements were made on rhodopsin heterologously expressed in E. coli thus allowing the effects of interacting proteins and membrane potential to be investigated. Evidence was found that the local environment of one or more internal water molecules in SRII is altered by interaction with its cognate transducer, HtrII, and is also affected by the local lipid environment. In the case of AR3, many of the broad IR continuum absorption changes below 3000 cm -1, assigned to networks of water molecules involved in proton transport through cytoplasmic and extracellular portions in BR, were found to be very similar to BR. Bands assigned to water molecules near the Schiff base postulated to be involved in proton transport were, however, shifted

  4. Double resonant absorption measurement of acetylene symmetric vibrational states probed with cavity ring down spectroscopy

    Science.gov (United States)

    Karhu, J.; Nauta, J.; Vainio, M.; Metsälä, M.; Hoekstra, S.; Halonen, L.

    2016-06-01

    A novel mid-infrared/near-infrared double resonant absorption setup for studying infrared-inactive vibrational states is presented. A strong vibrational transition in the mid-infrared region is excited using an idler beam from a singly resonant continuous-wave optical parametric oscillator, to populate an intermediate vibrational state. High output power of the optical parametric oscillator and the strength of the mid-infrared transition result in efficient population transfer to the intermediate state, which allows measuring secondary transitions from this state with a high signal-to-noise ratio. A secondary, near-infrared transition from the intermediate state is probed using cavity ring-down spectroscopy, which provides high sensitivity in this wavelength region. Due to the narrow linewidths of the excitation sources, the rovibrational lines of the secondary transition are measured with sub-Doppler resolution. The setup is used to access a previously unreported symmetric vibrational state of acetylene, ν 1 + ν 2 + ν 3 + ν4 1 + ν5 - 1 in the normal mode notation. Single-photon transitions to this state from the vibrational ground state are forbidden. Ten lines of the newly measured state are observed and fitted with the linear least-squares method to extract the band parameters. The vibrational term value was measured to be at 9775.0018(45) cm-1, the rotational parameter B was 1.162 222(37) cm-1, and the quartic centrifugal distortion parameter D was 3.998(62) × 10-6 cm-1, where the numbers in the parenthesis are one-standard errors in the least significant digits.

  5. Rapid identification of non-sporing anaerobes using nuclear magnetic resonance spectroscopy and an identification strategy

    Directory of Open Access Journals (Sweden)

    Menon S

    2007-01-01

    Full Text Available Purpose: The non-sporing anaerobes cause a wide spectrum of infections. They are difficult to culture and their identification is tedious and time-consuming. Rapid identification of anaerobes is highly desirable. Towards this end, the potential of nuclear magnetic resonance (NMR spectroscopy for providing a fingerprint within the proton spectrum of six genera belonging to anaerobes reflecting their characteristic metabolites has been investigated. Methods: NMR analysis was carried out using Mercury plus Varian 300 MHz (7.05 T NMR spectrophotometer on six different anaerobes. These included Bacteroides fragilis, Prevotella melaninogenica, Prevotella denticola, Fusobacterium necrophorum, Peptococcus niger and Peptostreptococcus spp. After the NMR analysis (256/512 scans, the different peaks were noted. The eight pus specimens, which yielded pure culture of anaerobe, also were analysed similarly. Results: The major resonances of multiplex of amino acids/lipid at 0.9 ppm along with lactate/lipid at 1.3 ppm, acetate at 1.92 ppm and multiplex of lysine at 3.0 ppm remained constant to label the organism as an anaerobe. There was a difference found in the MR spectra of different genera and species. A simple algorithm was developed for the identification of the six different anaerobes studied. The MR spectra of the pure culture of the organism matched the MR spectra of pus from which the organism was isolated. Conclusions: MR-based identification was of value in the identification of anaerobes. However, a larger database of the peaks produced by anaerobes needs to be created for identification of all genera and species. It could then have the potential of diagnosing an anaerobic infection in vivo and thus expedite management of deep-seated abscesses.

  6. Double resonant absorption measurement of acetylene symmetric vibrational states probed with cavity ring down spectroscopy.

    Science.gov (United States)

    Karhu, J; Nauta, J; Vainio, M; Metsälä, M; Hoekstra, S; Halonen, L

    2016-06-28

    A novel mid-infrared/near-infrared double resonant absorption setup for studying infrared-inactive vibrational states is presented. A strong vibrational transition in the mid-infrared region is excited using an idler beam from a singly resonant continuous-wave optical parametric oscillator, to populate an intermediate vibrational state. High output power of the optical parametric oscillator and the strength of the mid-infrared transition result in efficient population transfer to the intermediate state, which allows measuring secondary transitions from this state with a high signal-to-noise ratio. A secondary, near-infrared transition from the intermediate state is probed using cavity ring-down spectroscopy, which provides high sensitivity in this wavelength region. Due to the narrow linewidths of the excitation sources, the rovibrational lines of the secondary transition are measured with sub-Doppler resolution. The setup is used to access a previously unreported symmetric vibrational state of acetylene, ν1+ν2+ν3+ν4 (1)+ν5 (-1) in the normal mode notation. Single-photon transitions to this state from the vibrational ground state are forbidden. Ten lines of the newly measured state are observed and fitted with the linear least-squares method to extract the band parameters. The vibrational term value was measured to be at 9775.0018(45) cm(-1), the rotational parameter B was 1.162 222(37) cm(-1), and the quartic centrifugal distortion parameter D was 3.998(62) × 10(-6) cm(-1), where the numbers in the parenthesis are one-standard errors in the least significant digits.

  7. Lipid Resonance on In Vivo Proton MR Spectroscopy: Value of Other Metabolites in Differential Diagnosis.

    Science.gov (United States)

    Mohan, S; Verma, A; Lim, C C T; Hui, F; Kumar, S

    2010-06-01

    In vivo proton MR spectroscopy ((1)H-MRS) can non-invasively provide biochemical information at the same examination as conventional magnetic resonance imaging (MRI). Lipid resonance (0.9-1.5 ppm) is a marker of cell membrane breakdown and tissue necrosis, but its diagnostic significance has not been well described. We retrospectively analyzed spectra to study the different pathological conditions in patients with abnormal lipid resonance. All patients with neurological diseases showing lipid resonance on (1)H-MRS (1.5T) in a tertiary hospital over two years were retrospectively analyzed. (1)H-MRS was performed using the single voxel PRESS technique (TR/TE=3000/144 ms, eight excitations). Spectra were analysed for the presence of NAA (2.0 ppm), creatine (3.0 ppm), choline (3.2 ppm), acetate (1.92 ppm), succinate (2.4 ppm), cytosolic amino acids (0.9 ppm), lactate (1.3 ppm) and lipid (0.9-1.5 ppm) peaks. Ninety-two spectra from 69 patients (38 males, 31 females; aged 9 to 89 years) were analyzed. The final diagnosis was infective (n= 33), (tuberculoma n=17, pyogenic abscess n= 8, fungal abscess n= 3, sterile abscess n= 3, tubercular abscess n= 2), neoplastic (n= 21) (glial tumors n= 9, metastasis n= 8, lymphoma n= 4), and other (n= 15) abnormalities (subacute and chronic stroke n= 6, postictal edema n= 4, multiple sclerosis n= 2, Erdhiem Chester disease n= 2, Rosai Dorfmann disease n= 1). Succinate and acetate were detected only in pyogenic abscesses (2/4 cases), but amino acids were present in both pyogenic (4/8) and fungal (3/3) abscesses. Choline was seen not only in neoplasms (18) but also in tuberculomas (11/17), but was consistently absent in the abscesses. Lactate was present in glioblastoma (7/9), pyogenic (3/8) tubercular (2/2) and fungal (3/3) abscess. Isolated lipid resonance was found in Erdheim Chester disease (2/2) of the orbit, and lipid and choline was seen in Rosai Dorfmann's disease (1/1). Brain lesions containing lipid on (1)H-MRS could be

  8. Effect of ischemic preconditioning in skeletal muscle measured by functional magnetic resonance imaging and spectroscopy: a randomized crossover trial

    Directory of Open Access Journals (Sweden)

    Bartko Johann

    2011-06-01

    Full Text Available Abstract Background Nuclear magnetic resonance (NMR imaging and spectroscopy have been applied to assess skeletal muscle oxidative metabolism. Therefore, in-vivo NMR may enable the characterization of ischemia-reperfusion injury. The goal of this study was to evaluate whether NMR could detect the effects of ischemic preconditioning (IPC in healthy subjects. Methods Twenty-three participants were included in two randomized crossover protocols in which the effects of IPC were measured by NMR and muscle force assessments. Leg ischemia was administered for 20 minutes with or without a subsequent impaired reperfusion for 5 minutes (stenosis model. IPC was administered 4 or 48 hours prior to ischemia. Changes in 31phosphate NMR spectroscopy and blood oxygen level-dependent (BOLD signals were recorded. 3-Tesla NMR data were compared to those obtained for isometric muscular strength. Results The phosphocreatine (PCr signal decreased robustly during ischemia and recovered rapidly during reperfusion. In contrast to PCr, the recovery of muscular strength was slow. During post-ischemic stenosis, PCr increased only slightly. The BOLD signal intensity decreased during ischemia, ischemic exercise and post-ischemic stenosis but increased during hyperemic reperfusion. IPC 4 hours prior to ischemia significantly increased the maximal PCr reperfusion signal and mitigated the peak BOLD signal during reperfusion. Conclusions Ischemic preconditioning positively influenced muscle metabolism during reperfusion; this resulted in an increase in PCr production and higher oxygen consumption, thereby mitigating the peak BOLD signal. In addition, an impairment of energy replenishment during the low-flow reperfusion was detected in this model. Thus, functional NMR is capable of characterizing changes in reperfusion and in therapeutic interventions in vivo. Trial Registration ClinicalTrials.gov: NCT00883467

  9. Monitoring of the insecticide trichlorfon by phosphorus-31 nuclear magnetic resonance ({sup 31}P NMR) spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Talebpour, Zahra [Department of Chemistry, Faculty of Science, Alzahra University, Vanak, Tehran (Iran, Islamic Republic of); Ghassempour, Alireza [Medicinal Plants and Drugs Research Institute, Shahid Beheshti University, Faculty of Science, Chemistry Research Center, Evin, Tehran (Iran, Islamic Republic of)]. E-mail: aghassempour@scientist.com; Zendehzaban, Mehdi [Medicinal Plants and Drugs Research Institute, Shahid Beheshti University, Faculty of Science, Chemistry Research Center, Evin, Tehran (Iran, Islamic Republic of); Bijanzadeh, Hamid Reza [Faculty of Science, Tarbiat Modarres University, Tehran (Iran, Islamic Republic of); Mirjalili, Mohammad Hossein [Medicinal Plants and Drugs Research Institute, Shahid Beheshti University, Faculty of Science, Chemistry Research Center, Evin, Tehran (Iran, Islamic Republic of)

    2006-08-25

    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 {sup 31}P nuclear magnetic resonance ({sup 31}P NMR) has been described for monitoring of trichlorfon without any separation step. The quantitative works of {sup 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{sup -1}, without any sample preparation, and the linear working range was 150-5500 mg L{sup -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.

  10. A study of Roman glass by reflectance and electron paramagnetic resonance spectroscopies

    Science.gov (United States)

    Mirti, P.; Ferrari, R. P.; Laurenti, E.; Casoli, A.

    1993-08-01

    Reflectance and electron paramagnetic resonance (EPR) spectroscopies were used to study 25 fragments of Roman glass. Colour coordinates were used for an unbiased classification of the glasses in colour groups, which accounted for the presence of blue, blue-green, green, yellow-green, yellow and purple samples. Reflectance spectra were recorded in the 250-2500 nm wavelength range and showed absorption bands characteristic of Fe II, Fe III and Mn III ions; furthermore, Co II and Cu II bands were observed in the spectra of the blue glasses. A decrease of the absorbance ratio of Fe II to Fe III ions was observed moving from blue-green to green and yellow-green glasses; however, yellow fragments still proved to be reduced glasses. EPR spectra displayed the characteristic patterns of Fe III and Mn II ions, with g-values in the 2-5 interval and spectral features depending on the relative content of the two elements. The characteristic pattern of the V IV ion ( g ≈ 2) and signals due to the formation of iron-sulphur complexes ( g ≈ 6) appeared in the spectrum of a dark yellow glass, recorded at 77 K.

  11. Proton magnetic resonance spectroscopy in children with fetal alcohol spectrum disorders

    Energy Technology Data Exchange (ETDEWEB)

    Goncalves, Rita de Cassia Ferreira; Vasconcelos, Marcio Moacyr; Faleiros, Leticia Oliveira; Brito, Adriana Rocha; Werner Junior, Jairo; Herdy, Gesmar Volga Haddad [Universidade Federal Fluminense (UFF), Niteroi, RJ (Brazil). Faculdade de Medicina], e-mail: rcgonc@hotmail.com; Cruz Junior, Luiz Celso Hygino da; Domingues, Romeu Cortes [Multi-Imagem, Rio de Janeiro, RJ (Brazil)

    2009-06-15

    To analyze the metabolic constitution of brain areas through proton magnetic resonance spectroscopy in children affected with fetal alcohol spectrum disorder compared with normal children. Method: The sample of this case-control study included eight boys with epidemiologic history of in utero exposure to alcohol (median age 13.6{+-}3.8 years) who were diagnosed with fetal alcohol spectrum disorder, and eight controls (median age 12.1{+-}3,4 years). An 8 cm{sup 3} single voxel approach was used, with echo time 30 ms, repetition time 1500 ms, and 128 acquisitions in a 1.5T scanner, and four brain areas were analyzed: anterior cingulate, left frontal lobe, left striatum, and left cerebellar hemisphere. Peaks and ratios of metabolites N-acetylaspartate, choline, creatine, and myo-inositol were measured. Results: Children with fetal alcohol spectrum disorder showed a decrease in choline/creatine ratio (p=0.020) in left striatum and an increase in myo-inositol/creatine ratio (p=0.048) in left cerebellum compared with controls. There was no statistically significant difference in all peaks and ratios from the anterior cingulate and frontal lobe between the two groups. Conclusion: This study found evidence that the left striatum and left cerebellum are affected by intrauterine exposure to alcohol. Additional studies with larger samples are necessary to expand our knowledge of the effects of fetal exposure to alcohol. (author)

  12. Localized proton magnetic resonance spectroscopy of the brain differentiates the inborn metabolic encephalopathies in children

    Energy Technology Data Exchange (ETDEWEB)

    Chabrol, B.; Salvan, A.M.; Confort-Gouny, S.; Vion-Dury, J.; Cozzone, P.J. [Hopital de la Timone, 13 - Marseille (France)

    1995-09-01

    Localized brain proton magnetic resonance spectroscopy (MRS) has been performed using a STEAM (Stimulated echo-acquisition mode) method with a short-echo time (20ms) in 10 children suffering from different lysosomal diseases, 6 boys with X-linked adrenoleukodystrophy (X-ALD) and 5 healthy children. Metabolic data from localized spectra were processed by principal component analysis (PCA) of 7 metabolic variables recorded on the MR spectra. PCA allows to delineate different clusters corresponding to the 2 pathological groups which are separated from each other and from the control group. The position of each spectrum on the patient map correlates with the clinical data and to the evolution of the patients subjected to a follow-up. These results also confirm the metabolic features characterizing the pathologies of the lysosome (increase in inositol) and the peroxisome (increase in choline and free lipids). PCA constitutes an alternative to the classical statistical methods to analyze and compare metabolic modifications in small populations of patients and allows to identify the most critical parameters defining the organization of the pathological populations. This analysis clearly increases the discrimination among pathologies based on the metabolic profiles obtained by MRS. (author). 17 refs., 2 figs., 2 tabs.

  13. 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.

  14. Glutathione in the human brain: Review of its roles and measurement by magnetic resonance spectroscopy.

    Science.gov (United States)

    Rae, Caroline D; Williams, Stephen R

    2017-07-15

    We review the transport, synthesis and catabolism of glutathione in the brain as well as its compartmentation and biochemistry in different brain cells. The major reactions involving glutathione are reviewed and the factors limiting its availability in brain cells are discussed. We also describe and critique current methods for measuring glutathione in the human brain using magnetic resonance spectroscopy, and review the literature on glutathione measurements in healthy brains and in neurological, psychiatric, neurodegenerative and neurodevelopmental conditions In summary: Healthy human brain glutathione concentration is ∼1-2 mM, but it varies by brain region, with evidence of gender differences and age effects; in neurological disease glutathione appears reduced in multiple sclerosis, motor neurone disease and epilepsy, while being increased in meningiomas; in psychiatric disease the picture is complex and confounded by methodological differences, regional effects, length of disease and drug-treatment. Both increases and decreases in glutathione have been reported in depression and schizophrenia. In Alzheimer's disease and mild cognitive impairment there is evidence for a decrease in glutathione compared to age-matched healthy controls. Improved methods to measure glutathione in vivo will provide better precision in glutathione determination and help resolve the complex biochemistry of this molecule in health and disease. Copyright © 2017 Elsevier Inc. All rights reserved.

  15. Study of bioenergetics of mouse pregnant uterine muscle by magnetic resonance spectroscopy (MRS)

    Energy Technology Data Exchange (ETDEWEB)

    Negami, Akira; Tominaga, Toshiro

    1989-06-01

    To investigate the bioenergetics of uterine muscles in vivo, we examined the energy state of mouse preterm uterus by means of magnetic resonance spectroscopy. Full-term mouse uterus contained ATP, PCr, phospho-di and mono ester (PDE and PME) and inorganic phosphate (Pi). The oxytocin-induced uterine muscle contraction peaks level and positions changed. Multiple peak analysis indicated a muscle contraction induced increase in the Pi concentration and decrease in the PCr concentration. The peak position of Pi was shifted in the contractive state also, indicating that the intracellular pH was lower than in the non-contractive state and this low pH level was recovered within several minutes. There was no change in the AMP peak neight in the contractive and non-contractive states. These data indicated that the energetics of mouse uterine muscle was maintained by the ATP-PCr system and acidosis of muscle was recovered within several minutes at rest. The constant AMP peak levels may indicate that phosphorylase is not regulated by AMP, but the phosphorylated phosphorylase kinase and pH levels in the contractive and non-contractive states also may indicate that phosphorylase kinase is not regulated by proteolysis or by the intracellular pH level but by the elevated intracellular calcium ion and calmodulin system. (author).

  16. Fragile X syndrome: a pilot proton magnetic resonance spectroscopy study in premutation carriers

    LENUS (Irish Health Repository)

    Hallahan, Brian P

    2012-08-30

    AbstractPurposeThere is increasing evidence that neurodevelopmental differences in people with Fragile X syndrome (FraX) may be explained by differences in glutamatergic metabolism. Premutation carriers of FraX were originally considered to be unaffected although several recent reports demonstrate neuroanatomical, cognitive, and emotional differences from controls. However there are few studies on brain metabolism in premutation carriers of FraX.MethodsWe used proton magnetic resonance spectroscopy to compare neuronal integrity of a number of brain metabolites including N-Acetyl Aspartate, Creatine + Phosphocreatinine, Choline, myoInositol, and Glutamate containing substances (Glx) in 17 male premutation carriers of FraX and 16 male healthy control individuals.ResultsThere was no significant between-group difference in the concentration of any measured brain metabolites. However there was a differential increase in N-acetyl aspartate with aging in premutation FraX individuals compared to controls.ConclusionsThis is the first 1 H-MRS study to examine premutation FraX individuals. Although we demonstrated no difference in the concentration of any of the metabolites examined between the groups, this may be due to the large age ranges included in the two samples. The differential increase in NAA levels with aging may reflect an abnormal synaptic pruning process.

  17. Functional Magnetic Resonance Imaging and Functional Near-Infrared Spectroscopy: Insights from Combined Recording Studies.

    Science.gov (United States)

    Scarapicchia, Vanessa; Brown, Cassandra; Mayo, Chantel; Gawryluk, Jodie R

    2017-01-01

    Although blood oxygen level dependent (BOLD) functional magnetic resonance imaging (fMRI) is a widely available, non-invasive technique that offers excellent spatial resolution, it remains limited by practical constraints imposed by the scanner environment. More recently, functional near infrared spectroscopy (fNIRS) has emerged as an alternative hemodynamic-based approach that possesses a number of strengths where fMRI is limited, most notably in portability and higher tolerance for motion. To date, fNIRS has shown promise in its ability to shed light on the functioning of the human brain in populations and contexts previously inaccessible to fMRI. Notable contributions include infant neuroimaging studies and studies examining full-body behaviors, such as exercise. However, much like fMRI, fNIRS has technical constraints that have limited its application to clinical settings, including a lower spatial resolution and limited depth of recording. Thus, by combining fMRI and fNIRS in such a way that the two methods complement each other, a multimodal imaging approach may allow for more complex research paradigms than is feasible with either technique alone. In light of these issues, the purpose of the current review is to: (1) provide an overview of fMRI and fNIRS and their associated strengths and limitations; (2) review existing combined fMRI-fNIRS recording studies; and (3) discuss how their combined use in future research practices may aid in advancing modern investigations of human brain function.

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

    Science.gov (United States)

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

    2013-12-30

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

  19. Discrete magic angle turning system, apparatus, and process for in situ magnetic resonance spectroscopy and imaging

    Science.gov (United States)

    Hu, Jian Zhi [Richland, WA; Sears, Jr., Jesse A.; Hoyt, David W [Richland, WA; Wind, Robert A [Kennewick, WA

    2009-05-19

    Described are a "Discrete Magic Angle Turning" (DMAT) system, devices, and processes that combine advantages of both magic angle turning (MAT) and magic angle hopping (MAH) suitable, e.g., for in situ magnetic resonance spectroscopy and/or imaging. In an exemplary system, device, and process, samples are rotated in a clockwise direction followed by an anticlockwise direction of exactly the same amount. Rotation proceeds through an angle that is typically greater than about 240 degrees but less than or equal to about 360 degrees at constant speed for a time applicable to the evolution dimension. Back and forth rotation can be synchronized and repeated with a special radio frequency (RF) pulse sequence to produce an isotropic-anisotropic shift 2D correlation spectrum. The design permits tubes to be inserted into the sample container without introducing plumbing interferences, further allowing control over such conditions as temperature, pressure, flow conditions, and feed compositions, thus permitting true in-situ investigations to be carried out.

  20. Oxidative stress and depressive symptoms in older adults: A magnetic resonance spectroscopy study.

    Science.gov (United States)

    Duffy, Shantel L; Lagopoulos, Jim; Cockayne, Nicole; Hermens, Daniel F; Hickie, Ian B; Naismith, Sharon L

    2015-07-15

    Major depression is common in older adults and associated with greater health care utilisation and increased risk of poor health outcomes. Oxidative stress may be implicated in the pathophysiology of depression and can be measured via the neurometabolite glutathione using proton magnetic resonance spectroscopy ((1)H-MRS). This study aimed to examine the relationship between glutathione concentration and depressive symptom severity in older adults 'at-risk' of depression. In total, fifty-eight older adults considered 'at-risk' of depression (DEP) and 12 controls underwent (1)H-MRS, medical and neuropsychological assessments. Glutathione was measured in the anterior cingulate cortex (ACC), and calculated as a ratio to creatine. Depressive and anxiety symptoms were assessed using the Hospital Anxiety and Depression Scale (HADS). Compared to controls, DEP patients had increased glutathione/creatine ratios in the ACC (t=2.7, p=0.012). In turn, these increased ratios were associated with greater depressive symptoms (r=0.28, p=0.038), and poorer performance on a verbal learning task (r=-0.28, p=0.040). In conclusion, depressive symptoms in older people are associated with increased glutathione in the ACC. Oxidative stress may be pathophysiologically linked to illness development and may represent an early compensatory response. Further research examining the utility of glutathione as a marker for depressive symptoms and cognitive decline is now required. Copyright © 2015 Elsevier B.V. All rights reserved.

  1. MDM2-MDM4 molecular interaction investigated by atomic force spectroscopy and surface plasmon resonance.

    Science.gov (United States)

    Moscetti, Ilaria; Teveroni, Emanuela; Moretti, Fabiola; Bizzarri, Anna Rita; Cannistraro, Salvatore

    Murine double minute 2 (MDM2) and 4 (MDM4) are known as the main negative regulators of p53, a tumor suppressor. They are able to form heterodimers that are much more effective in the downregulation of p53. Therefore, the MDM2-MDM4 complex could be a target for promising therapeutic restoration of p53 function. To this aim, a deeper understanding of the molecular mechanisms underlining the heterodimerization is needed. The kinetic and thermodynamic characterization of the MDM2-MDM4 complex was performed with two complementary approaches: atomic force spectroscopy and surface plasmon resonance. Both techniques revealed an equilibrium dissociation constant (KD ) in the micromolar range for the MDM2-MDM4 heterodimer, similar to related complexes involved in the p53 network. Furthermore, the MDM2-MDM4 complex is characterized by a relatively high free energy, through a single energy barrier, and by a lifetime in the order of tens of seconds. New insights into the MDM2-MDM4 interaction could be highly important for developing innovative anticancer drugs focused on p53 reactivation.

  2. Technical and experimental features of Magnetic Resonance Spectroscopy of brain glycogen metabolism.

    Science.gov (United States)

    Soares, Ana Francisca; Gruetter, Rolf; Lei, Hongxia

    2017-07-15

    In the brain, glycogen is a source of glucose not only in emergency situations but also during normal brain activity. Altered brain glycogen metabolism is associated with energetic dysregulation in pathological conditions, such as diabetes or epilepsy. Both in humans and animals, brain glycogen levels have been assessed non-invasively by Carbon-13 Magnetic Resonance Spectroscopy (13C-MRS) in vivo. With this approach, glycogen synthesis and degradation may be followed in real time, thereby providing valuable insights into brain glycogen dynamics. However, compared to the liver and muscle, where glycogen is abundant, the sensitivity for detection of brain glycogen by 13C-MRS is inherently low. In this review we focus on strategies used to optimize the sensitivity for 13C-MRS detection of glycogen. Namely, we explore several technical perspectives, such as magnetic field strength, field homogeneity, coil design, decoupling, and localization methods. Furthermore, we also address basic principles underlying the use of 13C-labeled precursors to enhance the detectable glycogen signal, emphasizing specific experimental aspects relevant for obtaining kinetic information on brain glycogen. Copyright © 2016 Elsevier Inc. All rights reserved.

  3. Resonance Raman spectroscopy as an effective tool for the determination of antioxidative stability of cosmetic formulations.

    Science.gov (United States)

    Darvin, Maxim E; Sterry, Wolfram; Lademann, Jürgen

    2010-01-01

    Carotenoids beta-carotene, lutein, lycopene and others are well-known powerful antioxidants acting as an effective neutralizer of free radicals produced in the human organism as a result of the influence of stress factors, such as UV irradiation. The protective effect of antioxidants is used in cosmetic products to increase the skin protection against the destructive action of free radicals and for the stabilization of formulations against oxidation. In the skin, the different antioxidant substances form protection chains to avoid their destruction by the interaction with the free radicals. Similar effects have to be expected also in topically applied formulations. In the present study the influence of different mixtures of antioxidants (beta-carotene, vitamins C and E) on the stability of antioxidants in formulations used for skin treatment was investigated. The measurements were carried out by using non-invasive resonance Raman spectroscopy for the detection of the carotenoid concentration in the cosmetic formulations. 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. Energy calibration issues in nuclear resonant vibrational spectroscopy: observing small spectral shifts and making fast calibrations.

    Science.gov (United States)

    Wang, Hongxin; Yoda, Yoshitaka; Dong, Weibing; Huang, Songping D

    2013-09-01

    The conventional energy calibration for nuclear resonant vibrational spectroscopy (NRVS) is usually long. Meanwhile, taking NRVS samples out of the cryostat increases the chance of sample damage, which makes it impossible to carry out an energy calibration during one NRVS measurement. In this study, by manipulating the 14.4 keV beam through the main measurement chamber without moving out the NRVS sample, two alternative calibration procedures have been proposed and established: (i) an in situ calibration procedure, which measures the main NRVS sample at stage A and the calibration sample at stage B simultaneously, and calibrates the energies for observing extremely small spectral shifts; for example, the 0.3 meV energy shift between the 100%-(57)Fe-enriched [Fe4S4Cl4](=) and 10%-(57)Fe and 90%-(54)Fe labeled [Fe4S4Cl4](=) has been well resolved; (ii) a quick-switching energy calibration procedure, which reduces each calibration time from 3-4 h to about 30 min. Although the quick-switching calibration is not in situ, it is suitable for normal NRVS measurements.

  5. Creatine in the central nervous system: From magnetic resonance spectroscopy to creatine deficiencies.

    Science.gov (United States)

    Rackayova, Veronika; Cudalbu, Cristina; Pouwels, Petra J W; Braissant, Olivier

    2017-07-15

    Creatine (Cr) is an important organic compound acting as intracellular high-energy phosphate shuttle and in energy storage. While located in most cells where it plays its main roles in energy metabolism and cytoprotection, Cr is highly concentrated in muscle and brain tissues, in which Cr also appears to act in osmoregulation and neurotransmission. This review discusses the basis of Cr metabolism, synthesis and transport within brain cells. The importance of Cr in brain function and the consequences of its impaired metabolism in primary and secondary Cr deficiencies are also discussed. Cr and phosphocreatine (PCr) in living systems can be well characterized using in vivo magnetic resonance spectroscopy (MRS). This review describes how (1)H MRS allows the measurement of Cr and PCr, and how (31)P MRS makes it possible to estimate the creatine kinase (CK) rate constant and so detect dynamic changes in the Cr/PCr/CK system. Absolute quantification by MRS using creatine as internal reference is also debated. The use of in vivo MRS to study brain Cr in a non-invasive way is presented, as well as its use in clinical and preclinical studies, including diagnosis and treatment follow-up in patients. Copyright © 2016 Elsevier Inc. All rights reserved.

  6. Microcontroller based resonance tracking unit for time resolved continuous wave cavity-ringdown spectroscopy measurements.

    Science.gov (United States)

    Votava, Ondrej; Mašát, Milan; Parker, Alexander E; Jain, Chaithania; Fittschen, Christa

    2012-04-01

    We present in this work a new tracking servoloop electronics for continuous wave cavity-ringdown absorption spectroscopy (cw-CRDS) and its application to time resolved cw-CRDS measurements by coupling the system with a pulsed laser photolysis set-up. The tracking unit significantly increases the repetition rate of the CRDS events and thus improves effective time resolution (and/or the signal-to-noise ratio) in kinetics studies with cw-CRDS in given data acquisition time. The tracking servoloop uses novel strategy to track the cavity resonances that result in a fast relocking (few ms) after the loss of tracking due to an external disturbance. The microcontroller based design is highly flexible and thus advanced tracking strategies are easy to implement by the firmware modification without the need to modify the hardware. We believe that the performance of many existing cw-CRDS experiments, not only time-resolved, can be improved with such tracking unit without any additional modification to the experiment. © 2012 American Institute of Physics

  7. Even-parity Rydberg and autoionizing states of lutetium by laser resonance-ionization spectroscopy

    Science.gov (United States)

    Li, R.; Lassen, J.; Zhong, Z. P.; Jia, F. D.; Mostamand, M.; Li, X. K.; Reich, B. B.; Teigelhöfer, A.; Yan, H.

    2017-05-01

    Multistep laser resonance ionization spectroscopy of lutetium (Lu) has been performed at TRIUMF's off-line laser ion source test stand. The even-parity Rydberg series 6 s2n d 2D3 /2 , 6 s2n d 2D5 /2 , and 6 s2n s 2S1 /2 were observed converging to the 6 s2 ionization potential. The experimental results have been compared to those of previous work. Fifty-one levels of Rydberg series 6 s2n d 2D5 /2 and 52 levels of Rydberg series 6 s2n s 2S1 /2 were reported. Additionally, six even-parity autoionization (AI) series converging to Lu ionic states 5 d 6 s 3D1 and 5 d 6 s 3D2 were observed. The level energies of these AI states were measured. The configurations of the AI states were assigned by relativistic multichannel theory within the framework of multichannel quantum defect theory.

  8. Fragile X syndrome: a pilot proton magnetic resonance spectroscopy study in premutation carriers

    Directory of Open Access Journals (Sweden)

    Hallahan Brian P

    2012-08-01

    Full Text Available Abstract Purpose There is increasing evidence that neurodevelopmental differences in people with Fragile X syndrome (FraX may be explained by differences in glutamatergic metabolism. Premutation carriers of FraX were originally considered to be unaffected although several recent reports demonstrate neuroanatomical, cognitive, and emotional differences from controls. However there are few studies on brain metabolism in premutation carriers of FraX. Methods We used proton magnetic resonance spectroscopy to compare neuronal integrity of a number of brain metabolites including N-Acetyl Aspartate, Creatine + Phosphocreatinine, Choline, myoInositol, and Glutamate containing substances (Glx in 17 male premutation carriers of FraX and 16 male healthy control individuals. Results There was no significant between-group difference in the concentration of any measured brain metabolites. However there was a differential increase in N-acetyl aspartate with aging in premutation FraX individuals compared to controls. Conclusions This is the first 1 H-MRS study to examine premutation FraX individuals. Although we demonstrated no difference in the concentration of any of the metabolites examined between the groups, this may be due to the large age ranges included in the two samples. The differential increase in NAA levels with aging may reflect an abnormal synaptic pruning process.

  9. Magnetic Resonance Spectroscopy in Patients with Insomnia: A Repeated Measurement Study.

    Directory of Open Access Journals (Sweden)

    Kai Spiegelhalder

    Full Text Available Chronic insomnia is one of the most prevalent central nervous system disorders. It is characterized by increased arousal levels, however, the neurobiological causes and correlates of hyperarousal in insomnia remain to be further determined. In the current study, magnetic resonance spectroscopy was used in the morning and evening in a well-characterized sample of 20 primary insomnia patients (12 females; 8 males; 42.7 ± 13.4 years and 20 healthy good sleepers (12 females; 8 males; 44.1 ± 10.6 years. The most important inhibitory and excitatory neurotransmitters of the central nervous system, γ-aminobutyric acid (GABA and glutamate/glutamine (Glx, were assessed in the anterior cingulate cortex (ACC and dorsolateral prefrontal cortex (DLPFC. The primary hypothesis, a diurnal effect on GABA levels in patients with insomnia, could not be confirmed. Moreover, the current results did not support previous findings of altered GABA levels in individuals with insomnia. Exploratory analyses, however, suggested that GABA levels in the ACC may be positively associated with habitual sleep duration, and, thus, reduced GABA levels may be a trait marker of objective sleep disturbances. Moreover, there was a significant GROUP x MEASUREMENT TIME interaction effect on Glx in the DLPFC with increasing Glx levels across the day in the patients but not in the control group. Therefore, Glx levels may reflect hyperarousal at bedtime in those with insomnia. Future confirmatory studies should include larger sample sizes to investigate brain metabolites in different subgroups of insomnia.

  10. Human plasma metabolomics in age-related macular degeneration (AMD) using nuclear magnetic resonance spectroscopy.

    Science.gov (United States)

    Laíns, Inês; Duarte, Daniela; Barros, António S; Martins, Ana Sofia; Gil, João; Miller, John B; Marques, Marco; Mesquita, Tânia; Kim, Ivana K; Cachulo, Maria da Luz; Vavvas, Demetrios; Carreira, Isabel M; Murta, Joaquim N; Silva, Rufino; Miller, Joan W; Husain, Deeba; Gil, Ana M

    2017-01-01

    To differentiate the plasma metabolomic profile of patients with age related macular degeneration (AMD) from that of controls, by Nuclear Magnetic Resonance (NMR) spectroscopy. Two cohorts (total of 396 subjects) representative of central Portugal and Boston, USA phenotypes were studied. For each cohort, subjects were grouped according to AMD stage (early, intermediate and late). Multivariate analysis of plasma NMR spectra was performed, followed by signal integration and univariate analysis. Small changes were detected in the levels of some amino acids, organic acids, dimethyl sulfone and specific lipid moieties, thus providing some biochemical information on the disease. The possible confounding effects of gender, smoking history and age were assessed in each cohort and found to be minimal when compared to that of the disease. A similar observation was noted in relation to age-related comorbidities. Furthermore, partially distinct putative AMD metabolite fingerprints were noted for the two cohorts studied, reflecting the importance of nutritional and other lifestyle habits in determining AMD metabolic response and potential biomarker fingerprints. Notably, some of the metabolite changes detected were noted as potentially differentiating controls from patients diagnosed with early AMD. For the first time, this study showed metabolite changes in the plasma of patients with AMD as compared to controls, using NMR. Geographical origins were seen to affect AMD patients´ metabolic profile and some metabolites were found to be valuable in potentially differentiating controls from early stage AMD patients. Metabolomics has the potential of identifying biomarkers for AMD, and further work in this area is warranted.

  11. New observations concerning the interpretation of magnetic resonance spectroscopy of meningioma

    Energy Technology Data Exchange (ETDEWEB)

    Yue, Qiang [University of Tsukuba, Department of Neurosurgery, Institute of Clinical Medicine, Tsukuba Science City, Ibaraki (Japan); West China Hospital of Sichuan University, Huaxi MR Research Center, Department of Radiology, Chengdu (China); Isobe, Tomonori [Kitasato University, Department of Medical Technology, School of Allied Health Sciences, Minato (Japan); Shibata, Yasushi; Kawamura, Hiraku; Yamamoto, Youhei; Takano, Shingo; Matsumura, Akira [University of Tsukuba, Department of Neurosurgery, Institute of Clinical Medicine, Tsukuba Science City, Ibaraki (Japan); Anno, Izumi [University of Tsukuba, Department of Radiology, Institute of Clinical Medicine, Tsukuba (Japan)

    2008-12-15

    This study was aimed to clarify some ambiguities in the interpretation of proton magnetic resonance spectroscopy (1H-MRS) of meningiomas. The cases of 31 meningioma patients (27 benign and 4 nonbenign meningiomas) that underwent single-voxel 1H-MRS (PRESS sequence, TR/TE = 2,000 ms/68, 136, 272 ms) were retrospectively analyzed. To verify the findings of in-vivo study, phantoms were measured, and pathological sections of 11 patients were reviewed. All meningiomas demonstrated increased choline and decreased creatine, except for a lipomatous meningioma that only displayed a prominent lipid (Lip) peak. Alanine (Ala) and lactate (Lac) coexisted in eight cases, indicating an alternative pathway of energy metabolism in meningiomas. They partially overlapped with each other and demonstrated a triplet-like spectral pattern, which was consistent with phantom study. Glutamine/glutamate (Glx) was helpful for the recognition of meningioma when Ala was absent. N-acetyl compounds(NACs) were observed in nine cases whose voxels were completely limited within the tumors, indicating that meningiomas might have endogenous NACs. Lac was indicative of an aggressive meningioma, although not always a nonbenign one. Lip not only represented micronecrosis in nonbenign meningiomas, but also reflected microcystic changes or fatty degeneration in benign meningiomas. 1H-MRS reflects some distinctive biochemical and pathological changes of meningiomas that might be misinterpreted. (orig.)

  12. Absolute quantification of carnosine in human calf muscle by proton magnetic resonance spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Oezdemir, Mahir S [Department of Electronics and Information Systems, MEDISIP, Ghent University-IBBT-IBiTech, De Pintelaan 185 block B, B-9000 Ghent (Belgium); Reyngoudt, Harmen [Department of Radiology, Ghent University Hospital, De Pintelaan 185, Ghent (Belgium); Deene, Yves de [Department of Radiotherapy, Ghent University Hospital, De Pintelaan 185, Ghent (Belgium); Sazak, Hakan S [Department of Statistics, Ege University, 35100 Bornova, Izmir (Turkey); Fieremans, Els [Department of Electronics and Information Systems, MEDISIP, Ghent University-IBBT-IBiTech, De Pintelaan 185 block B, B-9000 Ghent (Belgium); Delputte, Steven [Department of Electronics and Information Systems, MEDISIP, Ghent University-IBBT-IBiTech, De Pintelaan 185 block B, B-9000 Ghent (Belgium); D' Asseler, Yves [Department of Electronics and Information Systems, MEDISIP, Ghent University-IBBT-IBiTech, De Pintelaan 185 block B, B-9000 Ghent (Belgium); Derave, Wim [Department of Movement and Sports Science, Ghent University, Watersportlaan 2, Ghent (Belgium); Lemahieu, Ignace [Department of Electronics and Information Systems, MEDISIP, Ghent University-IBBT-IBiTech, De Pintelaan 185 block B, B-9000 Ghent (Belgium); Achten, Eric [Department of Radiology, Ghent University Hospital, De Pintelaan 185, Ghent (Belgium)

    2007-12-07

    Carnosine has been shown to be present in the skeletal muscle and in the brain of a variety of animals and humans. Despite the various physiological functions assigned to this metabolite, its exact role remains unclear. It has been suggested that carnosine plays a role in buffering in the intracellular physiological pH{sub i} range in skeletal muscle as a result of accepting hydrogen ions released in the development of fatigue during intensive exercise. It is thus postulated that the concentration of carnosine is an indicator for the extent of the buffering capacity. However, the determination of the concentration of this metabolite has only been performed by means of muscle biopsy, which is an invasive procedure. In this paper, we utilized proton magnetic resonance spectroscopy ({sup 1}H MRS) in order to perform absolute quantification of carnosine in vivo non-invasively. The method was verified by phantom experiments and in vivo measurements in the calf muscles of athletes and untrained volunteers. The measured mean concentrations in the soleus and the gastrocnemius muscles were found to be 2.81 {+-} 0.57/4.8 {+-} 1.59 mM (mean {+-} SD) for athletes and 2.58 {+-} 0.65/3.3 {+-} 0.32 mM for untrained volunteers, respectively. These values are in agreement with previously reported biopsy-based results. Our results suggest that {sup 1}H MRS can provide an alternative method for non-invasively determining carnosine concentration in human calf muscle in vivo.

  13. Characterization of self-assembling copolymers in aqueous solutions using Electron Paramagnetic Resonance and Fluorescence spectroscopy.

    Science.gov (United States)

    Beghein, N; Rouxhet, L; Dinguizli, M; Brewster, M E; Ariën, A; Préat, V; Habib, J L; Gallez, B

    2007-02-12

    Electron Paramagnetic Resonance and fluorescence spectroscopy have been used to determine the micropolarity and microviscosity of self-assembling systems based on mmePEG-p(CL-co-TMC) having different PEG chain lengths and different CL/TMC ratios and PEG/MOG/SA (45/5/50) polymers with different PEG chain lengths. Four reporter probes have been used: two spin probes, 16-doxyl stearic acid and 5-doxylstearic acid, and two fluorescent probes, pyrene and 1,3-bis(1-pyrenyl) propane (P3P). We found that the micelles based on mmePEG-p(CL-co-TMC) polymers are of a biphasic nature. The micelles are made of a hydrophilic corona with low viscosity while the core of the micelle is more hydrophobic and more viscous. The outer shell is made up of PEG chains, the hydrophobic part of the chains making the core. The partial hydration of the shell seems to lead to a looser chain network than that associated with deeper domains in the micelles. By contrast, in micelles composed of PEG/MOG/SA, there is no clear domain separation. This is consistent with a spatial configuration of random polymeric chains forming a loose network. In these micelles, the microviscosity is low and the hydrophobicity is high.

  14. Cerebral immune activation in chronic hepatitis C infection: a magnetic resonance spectroscopy study.

    Science.gov (United States)

    Forton, Daniel M; Hamilton, Gavin; Allsop, Joanna M; Grover, Vijay P; Wesnes, Keith; O'Sullivan, Catherine; Thomas, Howard C; Taylor-Robinson, Simon D

    2008-09-01

    Abnormal cerebral metabolism and cognitive impairments have been reported in patients with chronic hepatitis C (HCV) but studies have failed to demonstrate a relationship between these findings. Twenty-five HCV-positive patients with histologically-mild liver disease were studied with cerebral proton magnetic resonance spectroscopy (MRS), using acquisition parameters to quantify myo-inositol (mI) and other metabolites in frontal white matter (FWM). Patients underwent automated attention and working memory tests (Cognitive Drug Research test system). The mean mI/ creatine ratio in the HCV+ve patients (0.64, SD 0.21) was significantly higher (p=0.02) than in healthy controls (0.52, SD 0.10). On cognitive testing, the HCV+ve patients showed impairments in 2/4 composite scores, reflecting working memory and attention, compared to normative data from healthy volunteers (pcognitive-motor disorder. It is associated with infection and immune activation of microglial cells. The similar findings in this study suggest that cerebral immune activation may also occur in HCV infection. This may underlie the mild neurocognitive impairment and neuropsychological symptoms observed in a proportion of patients.

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

    Science.gov (United States)

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

    2012-07-13

    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. Copyright © 2012 Elsevier B.V. All rights reserved.

  16. Towards radiation detected resonance ionization spectroscopy on transfermium elements in a buffer gas cell

    Energy Technology Data Exchange (ETDEWEB)

    Lautenschlaeger, Felix; Walther, Thomas [Institut fuer Angewandte Physik, TU Darmstadt, 64289 Darmstadt (Germany); Laatiaoui, Mustapha; Block, Michael [GSI Helmholtzzentrum fuer Schwerionenforschung GmbH, 64291 Darmstadt (Germany); Helmholtz-Institut Mainz, 55128 Mainz (Germany); Lauth, Werner; Backe, Hartmut [Institut fuer Kernphysik, JGU Mainz, 55128 Mainz (Germany); Hessberger, Fritz-Peter [GSI Helmholtzzentrum fuer Schwerionenforschung GmbH, 64291 Darmstadt (Germany)

    2013-07-01

    The study of the atomic structure of transfermium elements like nobelium (No) and lawrencium (Lr) via Radiation Detected Resonance Ionization Spectroscopy (RADRIS) is one of the most fascinating disciplines of modern atomic physics. It allows the determination of relativistic effects at the heaviest elements and provides a critical test of theoretical predictions. For these transfermium elements no experimental data on atomic level schemes are available at present. First experiments on {sup 254}No were performed in 2007, in which a buffer gas cell with an overall efficiency of 1%. In this experiment the evaporation temperature of nobelium was determined for the first time. To increase the efficiency of the buffer gas cell, off-line measurements have been performed with nat. ytterbium, the chemical homologue of nobelium. Also on-line experiments during a parasitic beam-time in 2012 provided an insight into the critical parameters of our setup. The results of the off-line and on-line measurements are briefly summarized in this talk.

  17. Axonal and glial microstructural information obtained with diffusion weighted magnetic resonance spectroscopy at 7T

    Directory of Open Access Journals (Sweden)

    Itamar eRonen

    2013-03-01

    Full Text Available Diffusion weighted magnetic resonance spectroscopy (DWS of brain metabolites offers unique access to compartment-specific microstructural information on tissue, and to a more sensitive detection of compartment-specific changes in tissue in health and disease. The specificity of DWS is offset, however, by its relative low sensitivity, intrinsic to all MRS-based methods, and further exacerbated by the signal loss due to the diffusion weighting and long echo times. In this work we first provide an example for the type of compartment-specific information that can be obtained with DWS from a small volume of interest in brain white matter. We then propose and discuss a strategy for the analysis of DWS data, which includes the use of models of diffusion in compartments with simple geometries and can be used to extract properties, such as the cytosolic diffusion coefficient of metabolites, which are potential markers for intracellular damage in neurological disorders. We conclude with a brief discussion of the potential role of DWS in the larger scope of tissue microstructural characterization and the complementarity of DWS with less specific but more sensitive microstructural tools, such as diffusion tensor imaging.

  18. Analyzing Xanthine Dehydrogenase Iron-Sulfur Clusters Using Electron Paramagnetic Resonance Spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Hodson, R.

    2004-02-05

    Xanthine dehydrogenase is a metalloenzyme that is present in a variety of eukaryotic and prokaryotic organisms. The oxidation of the xanthine occurs at the molybdenum site, and the catalytic cycle is completed by electron transfer to the iron-sulfur (Fe/S) clusters and finally the flavin, where they are accepted by nicotinamide adenine dinucleotide (NAD). Since the site giving rise to the Fe/S I electron paramagnetic resonance (EPR) signal is thought to be the initial recipient of the electrons from the Mo, we wish to understand which EPR signal is associated with which Fe/S cluster in the structure in order to develop an understanding of the electron flow within the molecule. Samples of xanthine dehydrogenase wild-type and mutant forms were analyzed with EPR spectroscopy techniques at low and high temperatures. The results showed an altered Fe/S I signal along with an unaltered Fe/S II signal. The converted Cysteine, in the mutant, did affect the Fe/S cluster immediately adjacent to it. Therefore, the Fe/S I signal arises from the Fe/S cluster closest to the Mo and immediately adjacent to the mutated amino acid, and the Fe/S II signal must arise from the more distant Fe/S cluster.

  19. Low-energy d-d excitations in MnO studied by resonant x-ray fluorescence spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Butorin, S.M.; Guo, J.; Magnuson, M. [Uppsala Univ. (Sweden)] [and others

    1997-04-01

    Resonant soft X-ray emission spectroscopy has been demonstrated to possess interesting abilities for studies of electronic structure in various systems, such as symmetry probing, alignment and polarization dependence, sensitivity to channel interference, etc. In the present abstract the authors focus on the feasibility of resonant soft X-ray emission to probe low energy excitations by means of resonant electronic X-ray Raman scattering. Resonant X-ray emission can be regarded as an inelastic scattering process where a system in the ground state is transferred to a low excited state via a virtual core excitation. The energy closeness to a core excitation of the exciting radiation enhances the (generally) low probability for inelastic scattering at these wavelengths. Therefore soft X-ray emission spectroscopy (in resonant electronic Raman mode) can be used to study low energy d-d excitations in transition metal systems. The involvement of the intermediate core state allows one to use the selection rules of X-ray emission, and the appearance of the elastically scattered line in the spectra provides the reference to the ground state.

  20. Magnetic resonance imaging in the evaluation of periosteal reactions

    Energy Technology Data Exchange (ETDEWEB)

    Nogueira-Barbosa, Marcello Henrique; Trad, Clovis Simao; Muglia, Valdair Francisco; Elias Junior, Jorge; Simao, Marcelo Novelino, E-mail: marcello@fmrp.usp.b [Universidade de Sao Paulo (USP), Ribeirao Preto, SP (Brazil). Faculdade de Medicina. Centro de Ciencias das Imagens e Fisica Medica; Sa, Jose Luiz de [Universidade de Sao Paulo (USP), Ribeirao Preto, SP (Brazil). Faculdade de Medicina. Hospital das Clinicas; Oliveira, Rodrigo Cecilio Vieira de [Clinica de Diagnostico por Imagem Tomoson, Aracatuba, SP (Brazil); Engel, Edgard Eduard [Universidade de Sao Paulo (USP), Ribeirao Preto, SP (Brazil). Faculdade de Medicina. Dept. de Biomecanica, Medicina e Reabilitacao do Aparelho Locomotor

    2010-07-15

    The objective of the present essay was to encourage a careful evaluation of periosteal reactions on magnetic resonance images. The initial approach to bone lesions is made by conventional radiography and, based on the imaging findings, periosteal reactions are classified into classical subtypes. Although magnetic resonance imaging is considered as the gold standard for local staging of bone tumors, the utilization of such method in the study of periosteal reactions related to focal bone lesions has been poorly emphasized, with relatively few studies approaching this subject. The literature review revealed a study describing an experimental animal model of osteomyelitis suggesting that magnetic resonance imaging is superior to other imaging methods in the early identification of periosteal reactions. Another study has suggested a good correlation between conventional radiography and magnetic resonance imaging in the identification and classification of periosteal reactions in cases of osteosarcoma. The present essay illustrates cases of periosteal reactions observed at magnetic resonance imaging in correlation with findings of conventional radiography or other imaging methods. (author)

  1. In vivo proton magnetic resonance spectroscopy of liver metabolites in non-alcoholic fatty liver disease in rats: T2 relaxation times in methylene protons.

    Science.gov (United States)

    Song, Kyu-Ho; Baek, Hyeon-Man; Lee, Do-Wan; Choe, Bo-Young

    2015-10-01

    The aim of this study was to evaluate the transverse relaxation time of methylene resonance as compared to other lipid resonances. The examinations were performed using a 3.0 T scanner with a point-resolved spectroscopy (PRESS) sequence. Lipid relaxation time in a lipid phantom filled with canola oil was estimated with a repetition time (TR) of 6000ms and echo time (TE) of 40-550ms. For in vivo proton magnetic resonance spectroscopy ((1)H-MRS), eight male Sprague-Dawley rats were given free access to a normal-chow (NC) and another eight male Sprague-Dawley rats were given free access to a high-fat (HF) diet. Both groups drank water ad libitum. T2 measurements in the rats' livers were conducted at a fixed TR of 6000ms and TE of 40-220ms. Exponential curve fitting quality was calculated through the coefficients of determination (R(2)). Chemical analyses of the phantom and livers were not performed, but T2 decay curves were acquired. The T2 relaxation time of methylene resonance was estimated as follows: NC rats, 37.1±4.3ms; HF rats, 31.4±1.8ms (p<0.05). The extrapolated M0 values were higher in HF rats than in NC rats (p<0.005). This study of (1)H MRS led to sufficient spectral resolution and signal-to-noise ratio differences to characterize the T2 relaxation times of methylene resonance. (1)H MRS relaxation times may be useful for quantitative characterization of various liver diseases, including fatty liver disease. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  2. Non-invasive assessment of Isocitrate dehydrogenase (IDH) mutational status in cerebral gliomas by Magnetic Resonance Spectroscopy in a clinical setting

    DEFF Research Database (Denmark)

    Tietze, Anna; Choi, Changho; Mickey, Bruce

    2016-01-01

    Background: Mutations in the Isocitrate Dehydrogenase (IDH) gene are of proven diagnostic and prognostic significance for cerebral gliomas. We evaluated the clinical feasibility of using a recently described method for determining IDH mutational status by using Magnetic Resonance Spectroscopy (MRS......) to detect the presence of 2-hydroxyglutarate (2HG), the metabolic product of the mutant IDH enzyme. Material&Methods: By extending our imaging time by 6 minutes, we were able to include a point-resolved spectroscopy (PRESS) MRS sequence in our routine glioma imaging protocol. Of 35 patients imaged, 30 were...... subsequently diagnosed histologically as gliomas. Of the remaining 5 patients, one had a gangliocytoma, one a primary CNS lymphoma, and 3 had non-neoplastic lesions. Immunohistochemistry and/or polymerase chain reaction (PCR) were used to detect the presence of IDH mutations in the glioma tissue resected...

  3. Bone marrow fat content in 70 adolescent girls with anorexia nervosa: Magnetic resonance imaging and magnetic resonance spectroscopy assessment.

    Science.gov (United States)

    Ecklund, Kirsten; Vajapeyam, Sridhar; Mulkern, Robert V; Feldman, Henry A; O'Donnell, Jennifer M; DiVasta, Amy D; Gordon, Catherine M

    2017-07-01

    Adolescents and women with anorexia nervosa have increased bone marrow fat and decreased bone formation, at least in part due to hormonal changes leading to preferential stem cell differentiation to adipocytes over osteoblasts. The purpose of this study was to evaluate marrow fat content and correlate with age and disease severity using knee MRI with T1 relaxometry (T1-R) and MR spectroscopy (MRS) in 70 adolescents with anorexia nervosa. We enrolled 70 girls with anorexia nervosa who underwent 3-T knee MRI with coronal T1-W images, T1-R and single-voxel proton MRS at 30 and 60 ms TE. Metaphyses were scored visually on the T1-W images for red marrow. Visual T1 score, T1 relaxometry values, MRS lipid indices and fat fractions were analyzed by regression on age, body mass index (BMI) and bone mineral density (BMD) as disease severity markers. MRS measures included unsaturated fat index, T2 water, unsaturated and saturated fat fractions. All red marrow measures declined significantly with age. T1-R values were associated negatively with BMI and BMD for girls ≤16 years (P=0.03 and P=0.002, respectively) and positively for those≥17 years (P=0.05 and P=0.003, respectively). MRS identified a strong inverse association between T2 water and saturated fat fraction from 60 ms TE data (r=-0.85, Panorexia nervosa. In contrast, the physiological association between marrow fat content and age remained dominant in younger patients. The strong association between T2 water and saturated fat may relate to the restricted mobility of water with increasing marrow fat.

  4. Bone marrow fat content in 70 adolescent girls with anorexia nervosa: Magnetic resonance imaging and magnetic resonance spectroscopy assessment

    Energy Technology Data Exchange (ETDEWEB)

    Ecklund, Kirsten; Vajapeyam, Sridhar; Mulkern, Robert V. [Boston Children' s Hospital, Department of Radiology, Boston, MA (United States); Feldman, Henry A. [Boston Children' s Hospital, Clinical Research Center, Boston, MA (United States); O' Donnell, Jennifer M. [Rutgers Robert Wood Johnson Medical School, New Brunswick, NJ (United States); DiVasta, Amy D. [Division of Adolescent/Young Adult Medicine, Boston, MA (United States); Gordon, Catherine M. [Cincinnati Children' s Hospital Medical Center, Division of Adolescent and Transition Medicine, Cincinnati, OH (United States)

    2017-07-15

    Adolescents and women with anorexia nervosa have increased bone marrow fat and decreased bone formation, at least in part due to hormonal changes leading to preferential stem cell differentiation to adipocytes over osteoblasts. The purpose of this study was to evaluate marrow fat content and correlate with age and disease severity using knee MRI with T1 relaxometry (T1-R) and MR spectroscopy (MRS) in 70 adolescents with anorexia nervosa. We enrolled 70 girls with anorexia nervosa who underwent 3-T knee MRI with coronal T1-W images, T1-R and single-voxel proton MRS at 30 and 60 ms TE. Metaphyses were scored visually on the T1-W images for red marrow. Visual T1 score, T1 relaxometry values, MRS lipid indices and fat fractions were analyzed by regression on age, body mass index (BMI) and bone mineral density (BMD) as disease severity markers. MRS measures included unsaturated fat index, T2 water, unsaturated and saturated fat fractions. All red marrow measures declined significantly with age. T1-R values were associated negatively with BMI and BMD for girls ≤16 years (P=0.03 and P=0.002, respectively) and positively for those≥17 years (P=0.05 and P=0.003, respectively). MRS identified a strong inverse association between T2 water and saturated fat fraction from 60 ms TE data (r=-0.85, P<0.0001). There was no association between unsaturated fat index and BMI or BMD. The association between T1 and BMI and BMD among older girls suggests more marrow fat in those with severe anorexia nervosa. In contrast, the physiological association between marrow fat content and age remained dominant in younger patients. The strong association between T2 water and saturated fat may relate to the restricted mobility of water with increasing marrow fat. (orig.)

  5. Reliable diagnosis of IDH-mutant glioblastoma by 2-hydroxyglutarate detection: a study by 3-T magnetic resonance spectroscopy.

    Science.gov (United States)

    Natsumeda, Manabu; Motohashi, Kunio; Igarashi, Hironaka; Nozawa, Takanori; Abe, Hideaki; Tsukamoto, Yoshihiro; Ogura, Ryosuke; Okada, Masayasu; Kobayashi, Tsutomu; Aoki, Hiroshi; Takahashi, Hitoshi; Kakita, Akiyoshi; Okamoto, Kouichirou; Nakada, Tsutomu; Fujii, Yukihiko

    2017-09-27

    We have previously reported that reliable detection of 2-hydroxyglutarate (2HG) in isocitrate dehydrogenase (IDH)-mutant WHO grade 2 and 3 gliomas is possible utilizing 3.0-T single-voxel magnetic resonance spectroscopy (SVMRS). We set out to determine whether the same method could be applied to detect 2HG in IDH-mutant glioblastoma. Forty-four patients harboring glioblastoma underwent pre-operative MRS evaluation to detect 2HG and other metabolites. Presence of IDH-mutations was determined by IDH1 R132H immunohistochemical analysis and DNA sequencing of surgically obtained tissues. Six out of 44 (13.6%) glioblastomas were IDH-mutant. IDH-mutant glioblastoma exhibited significantly higher accumulation of 2HG (median 3.191 vs. 0.000 mM, p IDH-mutation in glioblastoma. Glioblastoma with high 2HG accumulation did not have significantly longer overall survival than glioblastoma with low 2HG accumulation (p = 0.107, log-rank test). Non-invasive and reliable detection of 2HG in IDH-mutant glioblastoma was possible by 3.0-T SVMRS.

  6. Application of magnetic resonance spectroscopy in the differentiation of high-grade brain neoplasm and inflammatory brain lesions

    Energy Technology Data Exchange (ETDEWEB)

    Ferraz-Filho, Jose Roberto Lopes; Santana-Netto, Pedro Vieira; Sgnolf, Aline [FAMERP Medical School, Sao Jose do Rio Preto SP (Brazil). Image Dept.], e-mail: jrl.ferraz@terra.com.br; Rocha-Filho, Jose Alves; Mauad, Fernando [FAMERP Medical School, Sao Jose do Rio Preto SP (Brazil). Radiology Dept.; Sanches, Rafael Angelo [FAMERP Medical School, Sao Jose do Rio Preto SP (Brazil). Imaging Dept.

    2009-06-15

    This study aims at evaluating the application of magnetic resonance spectroscopy (MRS) in the differential diagnosis of brain tumors and inflammatory brain lesions. The examinations of 81 individuals, who performed brain MRS and were retrospectively analyzed. The patients with ages between 10 and 80 years old, were divided into two groups. Group A consisted of 42 individuals with diagnoses of cerebral toxoplasmosis and Group B was formed of 39 individuals with diagnosis of glial neoplasms. On analyzing the ROC curve, the discriminatory boundary for the Cho/Cr ratio between inflammatory lesions and tumors was 1.97 and for the NAA/Cr ratio it was 1.12. RMS is an important method useful in the distinction of inflammatory brain lesions and high-degree tumors when the Cho/Cr ratio is greater than 1.97 and the NAA/Cr ratio is less than 1.12. And so this method is important in the planning of treatment and monitoring of the therapeutic efficiency. (author)

  7. Myoinositol as a Biomarker in Recurrent Glioblastoma Treated with Bevacizumab: A 1H-Magnetic Resonance Spectroscopy Study.

    Science.gov (United States)

    Steidl, Eike; Pilatus, Ulrich; Hattingen, Elke; Steinbach, Joachim P; Zanella, Friedhelm; Ronellenfitsch, Michael W; Bähr, Oliver

    2016-01-01

    Antiangiogenic treatment of glioblastomas with Bevacizumab lacks predictive markers. Myoinositol (MI) is an organic osmolyte, with intracellular concentration changes depending on the extracellular osmolality. Since Bevacizumab markedly reduces tumor edema and influences the tumor microenvironment, we investigated whether the MI concentration in the tumor changes during therapy. We used 1H-magnetic resonance spectroscopy to measure the MI concentrations in the tumor and contralateral control tissue of 39 prospectively recruited patients with recurrent glioblastomas before and 8-12 weeks after starting therapy. 30 patients received Bevacizumab and 9 patients were treated with CCNU/VM26 as control. We performed a survival analysis to evaluate MI as a predictive biomarker for Bevacizumab therapy. MI concentrations increased significantly during Bevacizumab therapy in tumor (p 1,817 mmol/l. No differences were observed for the relative changes or the post treatment concentrations. Additionally calculated creatine concentrations showed no differences in between subgroups or between pre and post treatment measurements. Our data suggest that recurrent glioblastoma shows a strong metabolic reaction to Bevacizumab. Further, our results support the hypothesis that MI might be a marker for early tumor cell invasion. Pre-therapeutic MI concentrations are predictive of overall survival in patients with recurrent glioblastoma treated with Bevacizumab.

  8. Myoinositol as a Biomarker in Recurrent Glioblastoma Treated with Bevacizumab: A 1H-Magnetic Resonance Spectroscopy Study.

    Directory of Open Access Journals (Sweden)

    Eike Steidl

    Full Text Available Antiangiogenic treatment of glioblastomas with Bevacizumab lacks predictive markers. Myoinositol (MI is an organic osmolyte, with intracellular concentration changes depending on the extracellular osmolality. Since Bevacizumab markedly reduces tumor edema and influences the tumor microenvironment, we investigated whether the MI concentration in the tumor changes during therapy.We used 1H-magnetic resonance spectroscopy to measure the MI concentrations in the tumor and contralateral control tissue of 39 prospectively recruited patients with recurrent glioblastomas before and 8-12 weeks after starting therapy. 30 patients received Bevacizumab and 9 patients were treated with CCNU/VM26 as control. We performed a survival analysis to evaluate MI as a predictive biomarker for Bevacizumab therapy.MI concentrations increased significantly during Bevacizumab therapy in tumor (p 1,817 mmol/l. No differences were observed for the relative changes or the post treatment concentrations. Additionally calculated creatine concentrations showed no differences in between subgroups or between pre and post treatment measurements.Our data suggest that recurrent glioblastoma shows a strong metabolic reaction to Bevacizumab. Further, our results support the hypothesis that MI might be a marker for early tumor cell invasion. Pre-therapeutic MI concentrations are predictive of overall survival in patients with recurrent glioblastoma treated with Bevacizumab.

  9. Proton Magnetic Resonance Spectroscopy Study on the Metabolism Changes of Cerebellum in Patients with Post-Stroke Depression.

    Science.gov (United States)

    Zhang, Lei; Sui, Ru-Bo

    2017-01-01

    To study the metabolic changes of cerebellum by proton magnetic resonance Spectroscopy (1H-MRS) and discuss the relationships between the cerebellar changes and depression severity in patients with post-stroke depression. Data of demographic characteristics, individual history and life style of all subjects were collected. 40 patients with stroke and 20 controls were enrolled. All groups received T1WI, T2WI, DWI and 1H-MRS examination. The cerebral infarction volume and the distribution and severity of leukoaraiosis were evaluated. The ratios of NAA/Cr, Cho/Cr and Cho/NAA in the cerebellum were calculated. There were no statistical significant difference in the NAA/Cr, Cho/Cr and Cho/NAA ratios in bilateral cerebellum between CONT group and NORM group. The Cho/Cr and Cho/NAA ratios in the cerebellum contralateral to the stroke region were higher in PSD group than those in NORM and CONT groups, and the Cho/Cr and Cho/NAA ratios in the cerebellum ipsilateral to the stroke region were similar with those in NORM and CONT groups. However, there were no statistical significant difference in the NAA/Cr ratios in bilateral cerebellum among three groups. The result shows preliminarily that the cerebellum involves in the development of post-stroke depression. © 2017 The Author(s). Published by S. Karger AG, Basel.

  10. T2 corrected quantification method of L-p-boronophenylalanine using proton magnetic resonance spectroscopy for boron neutron capture therapy

    Energy Technology Data Exchange (ETDEWEB)

    Yamamoto, Yohei [Department of Neurosurgery, Institute of Clinical Medicine, Graduated School of Comprehensive Human Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki (Japan); Isobe, Tomonori [Institute of Clinical Medicine, Graduated School of Comprehensive Human Sciences, University of Tsukuba (Japan); Yamamoto, Tetsuya [Department of Neurosurgery, Institute of Clinical Medicine, Graduated School of Comprehensive Human Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki (Japan)], E-mail: tetsu-ya@md.tsukuba.ac.jp; Shibata, Yasushi [Department of Neurosurgery, Institute of Clinical Medicine, Graduated School of Comprehensive Human Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki (Japan); Anno, Izumi [Department of Radiological Sciences, Ibaraki Prefectural University of Health Sciences (Japan); Nakai, Kei; Shirakawa, Makoto; Matsushita, Akira [Department of Neurosurgery, Institute of Clinical Medicine, Graduated School of Comprehensive Human Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki (Japan); Sato, Eisuke [School of Allied Health Sciences, Kitasato University (Japan); Matsumura, Akira [Department of Neurosurgery, Institute of Clinical Medicine, Graduated School of Comprehensive Human Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki (Japan)

    2009-07-15

    In the present study, we aimed to evaluate a T2 corrected quantification method of L-p-boronophenylalanine (BPA) concentration using proton magnetic resonance spectroscopy (MRS). We used five phantoms containing BPA (1.5, 3.0, 5.0, 7.5, and 10 mmol/kg=15, 30, 50, 75, and 100 {mu}g{sup 10}B/g), N-acetyl-aspartic acid (NAA: 3.0 mmol/kg), creatine (Cr: 5.0 mmol/kg), and choline (Cho: 3.0 mmol/kg). The signal intensities of BPA and internal water were corrected by T2 relaxation time. The absolute concentrations of BPA were calculated by proton MRS using an internal water signal as a standard. The major BPA peaks were detected between 7.1 and 7.6 ppm. Mean T2 relaxation time was 314.3{+-}10.8 ms in BPA, 885.1{+-}39.7 ms in internal water. The calculated BPA concentrations were almost same as the actual concentration of BPA and the correlation coefficient was 0.99. Our BPA quantification method was very simple and non-invasive, also it had high accuracy. Therefore, our results indicate that proton MRS can be potentially useful technique for in vivo BPA quantification in boron neutron capture therapy (BNCT)

  11. Spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Hellman, Hal

    1968-01-01

    This booklet discusses spectroscopy, the study of absorption of radiation by matter, including X-ray, gamma-ray, microwave, mass spectroscopy, as well as others. Spectroscopy has produced more fundamental information to the study of the detailed structure of matter than any other tools.

  12. 31P-magnetic resonance spectroscopy assessment of subnormal oxidative metabolism in skeletal muscle of renal failure patients.

    OpenAIRE

    Moore, G E; Bertocci, L A; Painter, P L

    1993-01-01

    In hemodialysis patients, erythropoietin increases hemoglobin, but often the corresponding increase in peak oxygen uptake is low. The disproportionality may be caused by impaired energy metabolism. 31P-magnetic resonance spectroscopy was used to study muscle energy metabolism in 11 hemodialysis patients, 11 renal transplant recipients, and 9 controls. Measurements were obtained during rest, static hand-grip, and rhythmic hand-grip; recoveries were followed to baseline. During static hand-grip...

  13. Spectroscopy

    CERN Document Server

    Walker, S

    1976-01-01

    The three volumes of Spectroscopy constitute the one comprehensive text available on the principles, practice and applications of spectroscopy. By giving full accounts of those spectroscopic techniques only recently introduced into student courses - such as Mössbauer spectroscopy and photoelectron spectroscopy - in addition to those techniques long recognised as being essential in chemistry teaching - sucha as e.s.r. and infrared spectroscopy - the book caters for the complete requirements of undergraduate students and at the same time provides a sound introduction to special topics for graduate students.

  14. Detection of reactive oxygen species in isolated, perfused lungs by electron spin resonance spectroscopy

    Directory of Open Access Journals (Sweden)

    Schudt Christian

    2005-07-01

    Full Text Available Abstract Background The sources and measurement of reactive oxygen species (ROS in intact organs are largely unresolved. This may be related to methodological problems associated with the techniques currently employed for ROS detection. Electron spin resonance (ESR with spin trapping is a specific method for ROS detection, and may address some these technical problems. Methods We have established a protocol for the measurement of intravascular ROS release from isolated buffer-perfused and ventilated rabbit and mouse lungs, combining lung perfusion with the spin probe l-hydroxy-3-carboxy-2,2,5,5-tetramethylpyrrolidine (CPH and ESR spectroscopy. We then employed this technique to characterize hypoxia-dependent ROS release, with specific attention paid to NADPH oxidase-dependent superoxide formation as a possible vasoconstrictor pathway. Results While perfusing lungs with CPH over a range of inspired oxygen concentrations (1–21 %, the rate of CP• formation exhibited an oxygen-dependence, with a minimum at 2.5 % O2. Addition of superoxide dismutase (SOD to the buffer fluid illustrated that a minor proportion of this intravascular ROS leak was attributable to superoxide. Stimulation of the lungs by injection of phorbol-12-myristate-13-acetate (PMA into the pulmonary artery caused a rapid increase in CP• formation, concomitant with pulmonary vasoconstriction. Both the PMA-induced CPH oxidation and the vasoconstrictor response were largely suppressed by SOD. When the PMA challenge was performed at different oxygen concentrations, maximum superoxide liberation and pulmonary vasoconstriction occurred at 5 % O2. Using a NADPH oxidase inhibitor and NADPH-oxidase deficient mice, we illustrated that the PMA-induced superoxide release was attributable to the stimulation of NADPH oxidases. Conclusion The perfusion of isolated lungs with CPH is suitable for detection of intravascular ROS release by ESR spectroscopy. We employed this technique to

  15. Proton magnetic resonance spectroscopy of the motor cortex in cervical myelopathy.

    Science.gov (United States)

    Kowalczyk, Izabela; Duggal, Neil; Bartha, Robert

    2012-02-01

    Alterations in motor function in cervical myelopathy secondary to degenerative disease may be due to local effects of spinal compression or distal effects related to cortical reorganization. This prospective study characterizes differences in metabolite levels in the motor cortex, specifically N-acetylaspartate, creatine, choline, myo-inositol and glutamate plus glutamine, due to alterations in cortical function in patients with reversible spinal cord compression compared with healthy controls. We hypothesized that N-acetylaspartate/creatine levels would be decreased in the motor cortex of patients with cervical myelopathy due to reduced neuronal integrity/function and myo-inositol/creatine levels would be increased due to reactive gliosis. Twenty-four patients with cervical myelopathy and 11 healthy controls underwent proton-magnetic resonance spectroscopy on a 3.0 Tesla Siemens Magnetom Tim Trio MRI. Areas of activation from functional magnetic resonance imaging scans of a finger-tapping paradigm were used to localize a voxel on the side of greater motor deficit in the myelopathy group (n = 10 on right side and n = 14 on left side of the brain) and on each side of the motor cortex in controls. Neurological function was measured with the Neck Disability Index, modified Japanese Orthopaedic Association and American Spinal Injury Association questionnaires. Metabolite levels were measured relative to total creatine within the voxel of interest. No metabolite differences were detected between the right side and left side of the motor cortex in controls. The myelopathy group had significantly decreased neurological function compared with the control group (Neck Disability Index: P myelopathy group (1.21 ± 0.07) compared with the right (1.37 ± 0.03; P = 0.01) and left (1.38 ± 0.03; P = 0.007) motor cortex in controls suggesting neuronal damage or dysfunction distal to the lesion in the spine. No difference was observed in levels of myo

  16. Fourier Transform Infrared (FTIR) Spectroscopy, Ultraviolet Resonance Raman (UVRR) Spectroscopy, and Atomic Force Microscopy (AFM) for Study of the Kinetics of Formation and Structural Characterization of Tau Fibrils.

    Science.gov (United States)

    Ramachandran, Gayathri

    2017-01-01

    Kinetic studies of tau fibril formation in vitro most commonly employ spectroscopic probes such as thioflavinT fluorescence and laser light scattering or negative stain transmission electron microscopy. Here, I describe the use of Fourier transform infrared (FTIR) spectroscopy, ultraviolet resonance Raman (UVRR) spectroscopy, and atomic force microscopy (AFM) as complementary probes for studies of tau aggregation. The sensitivity of vibrational spectroscopic techniques (FTIR and UVRR) to secondary structure content allows for measurement of conformational changes that occur when the intrinsically disordered protein tau transforms into cross-β-core containing fibrils. AFM imaging serves as a gentle probe of structures populated over the time course of tau fibrillization. Together, these assays help further elucidate the structural and mechanistic complexity inherent in tau fibril formation.

  17. Brain glutamate in anorexia nervosa: a magnetic resonance spectroscopy case control study at 7 Tesla.

    Science.gov (United States)

    Godlewska, Beata R; Pike, Alexandra; Sharpley, Ann L; Ayton, Agnes; Park, Rebecca J; Cowen, Philip J; Emir, Uzay E

    2017-02-01

    Anorexia nervosa (AN) is a serious psychiatric disorder with high morbidity and mortality. There are no established pharmacological treatments and the neurobiology of the condition is poorly understood. Previous studies using magnetic resonance spectroscopy (MRS) have shown that AN may be associated with reductions in indices of brain glutamate; however, at conventional field strengths (≤3 T), it is difficult to separate glutamate from its precursor and metabolite, glutamine. The objective of the present study was to use high field (7 T) MRS to measure concentrations of glutamate, in three separate brain voxels, in women with AN. We studied 13 female participants with AN and 12 healthy female controls who underwent MRS scanning at 7 T with voxels placed in anterior cingulate cortex, occipital cortex and putamen. Neurometabolites were calculated using the unsuppressed water signal as a reference and corrected for individual cerebrospinal fluid concentration in the voxel. We found that participants with AN had significantly lower concentrations of glutamate in all three voxels (mean reduction 8%, p = 0.002) but glutamine levels were not altered. Concentrations of N-acetylaspartate, creatine, GABA and glutathione were also unchanged. However, inositol was lower in AN participants in anterior cingulate (p = 0.022) and occipital cortex (p = 0.002). Women with AN apparently have widespread reductions in brain glutamate. Further work will be needed to assess if this change has pathophysiological relevance or whether it is a consequence of the many physical changes produced in AN by food restriction.

  18. Brain Phosphorus Magnetic Resonance Spectroscopy Imaging of Sleep Homeostasis and Restoration in Drug Dependence

    Directory of Open Access Journals (Sweden)

    George H. Trksak

    2007-01-01

    Full Text Available Numerous reports have documented a high occurrence of sleep difficulties in drug-dependent populations, prompting researchers to characterize sleep profiles and physiology in drug abusing populations. This mini-review examines studies indicating that drug-dependent populations exhibit alterations in sleep homeostatic and restoration processes in response to sleep deprivation. Sleep deprivation is a principal sleep research tool that results in marked physiological challenge, which provides a means to examine sleep homeostatic processes in response to extended wakefulness. A report from our laboratory demonstrated that following recovery sleep from sleep deprivation, brain high-energy phosphates particularly beta–nucleoside triphosphate (beta-NTP are markedly increased as measured with phosphorus magnetic resonance spectroscopy (MRS. A more recent study examined the effects of sleep deprivation in opiate-dependent methadone-maintained (MM subjects. The study demonstrated increases in brain beta-NTP following recovery sleep. Interestingly, these increases were of a markedly greater magnitude in MM subjects compared to control subjects. A similar study examined sleep deprivation in cocaine-dependent subjects demonstrating that cocaine-dependent subjects exhibit greater increases in brain beta-NTP following recovery sleep when compared to control subjects. The studies suggest that sleep deprivation in both MM subjects and cocaine-dependent subjects is characterized by greater changes in brain ATP levels than control subjects. Greater enhancements in brain ATP following recovery sleep may reflect a greater disruption to or impact of sleep deprivation in drug dependent subjects, whereby sleep restoration processes may be unable to properly regulate brain ATP and maintain brain high-energy equilibrium. These studies support the notion of a greater susceptibility to sleep loss in drug dependent populations. Additional sleep studies in drug abusing

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2005-07-01

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

  20. Electron Paramagnetic Resonance Spectroscopy of Photosynthetic Systems and Inorganic Model Complexes.

    Science.gov (United States)

    Dexheimer, Susan Lynne

    1990-01-01

    This thesis discusses the application of parallel polarization electron paramagnetic resonance (EPR) spectroscopy, a technique sensitive to formally forbidden transitions in high spin states, to the study of the electronic structure of photosynthetic electron transfer centers and related inorganic model complexes. The theoretical basis for the origin of the parallel polarization transitions and the interpretation of the resulting spectra is presented, and experimental aspects of the detection of parallel polarization transitions are discussed. Parallel polarization EPR was used to study inorganic complexes of trivalent manganese that serve as models for the spectroscopic properties of biological electron transfer centers. X-band EPR spectra were detected from non-Kramers spin states of these complexes. EPR spectra of the S = 2 ground states of the mononuclear complexes Mn(III) tris -acetylacetonate and Mn(III) tris-picolinate and a low-lying excited state of the weakly antiferromagnetically coupled binuclear complex Mn_2(III,III) O(O_2CCH_3) _2 (HB(pz)_3) _2 (HB(pz)_3 = hydrotris(1-pyrazolyl)borate) are discussed. The spectra are interpreted using numerical simulations. Application of parallel polarization EPR to photosyntheic systems led to the detection of a new paramagnetic intermediate associated with photosynthetic water oxidation. The parallel polarization EPR signal is assigned to an S = 1 spin state of an exchange-coupled manganese center in the resting (S_1) state of the photosynthetic oxygen-evolving complex. The properties of the S _1 state parallel polarization EPR signal indicate that it corresponds to the reduced form of the species that gives rise to the previously established multiline conventional EPR signal in the light-induced S _2 state, and the behavior of the signal upon advancement to the S_2 state demonstrates the presence of two separate redox-active centers in the oxygen-evolving complex. The implications for the electronic structure of

  1. In vivo proton magnetic resonance spectroscopy of breast lesions: an update.

    Science.gov (United States)

    Tse, Gary M; Yeung, David K Y; King, Ann D; Cheung, Humairah S; Yang, Wei-Tse

    2007-09-01

    In vivo proton magnetic resonance spectroscopy ((1)H-MRS) has been demonstrated to be successful in the differentiation of benign and malignant breast lesions in a non-invasive manner by detecting increased levels of composite choline (Cho) compounds. Currently there is molecular evidence of increased Cho metabolism in breast cancer cells. In breast malignancies, (1)H-MRS achieved a high-overall sensitivity (82%). Most test cases were infiltrating duct carcinoma, but infiltrating lobular, medullary, mucinous and adenoid cystic carcinomas were also positive by (1)H-MRS. Large lesional size is a pre-requisite for (1)H-MRS testing, and technical problems account for some of the false negative results. Another potential of (1)H-MRS is to assess patients' response to neoadjuvant chemotherapy. In ductal carcinoma in situ, the results of (1)H-MRS on the limited number of cases were negative. Most of the assessed benign breast lesions including fibroadenoma, fibrocystic changes, cysts and galactoceles, papilloma, tubular adenoma and phyllodes tumours and were mostly negative by (1)H-MRS, with an overall false positive rate was about 8%. Normal breast tissue was almost always negative by (1)H-MRS, whereas, lactating breast tissue showed positivity with a slightly different spectrum on further analysis. With the clinical use of stronger field MR scanners and better coils, the sensitivity of (1)H-MRS may be further improved. With these improvements, (1)H-MRS may potentially be useful in detection of smaller malignant lesions, characterization of malignant lesions into non-invasive or invasive, and as an invaluable tool in disease progression monitoring.

  2. Optimized multimodal functional magnetic resonance imaging/near-infrared spectroscopy probe for ultrahigh-resolution mapping

    Science.gov (United States)

    Hocke, Lia Maria; Cayetano, Kenroy; Tong, Yunjie; Frederick, Blaise

    2015-01-01

    Abstract. Functional near-infrared spectroscopy (fNIRS) is an increasingly important noninvasive method in neuroscience due to its high temporal resolution and ability to independently measure oxy- and deoxy-hemoglobin. However, the relatively low spatial resolution of fNIRS makes it difficult to relate this signal to underlying anatomy. Simultaneous functional magnetic resonance imaging (fMRI) can complement fNIRS with superior spatial resolution and the ability to image the entire brain, providing additional information to improve fNIRS localization. However, current simultaneous fMRI/fNIRS acquisition methods are not optimal, due to the poor physical compatibility of existing MR coils and fNIRS optodes. Here, we present a technique to manufacture a true multimodal fMRI/fNIRS probe in which both modalities can be used with maximal sensitivity. To achieve this, we designed custom MR coils with integral fNIRS optodes using three-dimensional printing. This multimodal probe can be used to optimize spatial (1.2×1.2×1.8  mm) and temporal resolution (2.5 Hz) of fMRI, and it provides maximal MRI sensitivity, while allowing for high flexibility in the location and density of fNIRS optodes within the area of interest. Phantom and human data are shown to confirm the improvement in sensitivity in both modalities. This probe shows promise for addressing fundamental questions of the relation of fNIRS to physiology. PMID:26668816

  3. Functional Magnetic Resonance Imaging and Functional Near-Infrared Spectroscopy: Insights from Combined Recording Studies

    Directory of Open Access Journals (Sweden)

    Vanessa Scarapicchia

    2017-08-01

    Full Text Available Although blood oxygen level dependent (BOLD functional magnetic resonance imaging (fMRI is a widely available, non-invasive technique that offers excellent spatial resolution, it remains limited by practical constraints imposed by the scanner environment. More recently, functional near infrared spectroscopy (fNIRS has emerged as an alternative hemodynamic-based approach that possesses a number of strengths where fMRI is limited, most notably in portability and higher tolerance for motion. To date, fNIRS has shown promise in its ability to shed light on the functioning of the human brain in populations and contexts previously inaccessible to fMRI. Notable contributions include infant neuroimaging studies and studies examining full-body behaviors, such as exercise. However, much like fMRI, fNIRS has technical constraints that have limited its application to clinical settings, including a lower spatial resolution and limited depth of recording. Thus, by combining fMRI and fNIRS in such a way that the two methods complement each other, a multimodal imaging approach may allow for more complex research paradigms than is feasible with either technique alone. In light of these issues, the purpose of the current review is to: (1 provide an overview of fMRI and fNIRS and their associated strengths and limitations; (2 review existing combined fMRI-fNIRS recording studies; and (3 discuss how their combined use in future research practices may aid in advancing modern investigations of human brain function.

  4. Impaired in vivo mitochondrial Krebs cycle activity after myocardial infarction assessed using hyperpolarized magnetic resonance spectroscopy.

    Science.gov (United States)

    Dodd, Michael S; Atherton, Helen J; Carr, Carolyn A; Stuckey, Daniel J; West, James A; Griffin, Julian L; Radda, George K; Clarke, Kieran; Heather, Lisa C; Tyler, Damian J

    2014-11-01

    Myocardial infarction (MI) is one of the leading causes of heart failure. An increasing body of evidence links alterations in cardiac metabolism and mitochondrial function with the progression of heart disease. The aim of this work was to, therefore, follow the in vivo mitochondrial metabolic alterations caused by MI, thereby allowing a greater understanding of the interplay between metabolic and functional abnormalities. Using hyperpolarized carbon-13 ((13)C)-magnetic resonance spectroscopy, in vivo alterations in mitochondrial metabolism were assessed for 22 weeks after surgically induced MI with reperfusion in female Wister rats. One week after MI, there were no detectable alterations in in vivo cardiac mitochondrial metabolism over the range of ejection fractions observed (from 28% to 84%). At 6 weeks after MI, in vivo mitochondrial Krebs cycle activity was impaired, with decreased (13)C-label flux into citrate, glutamate, and acetylcarnitine, which correlated with the degree of cardiac dysfunction. These changes were independent of alterations in pyruvate dehydrogenase flux. By 22 weeks, alterations were also seen in pyruvate dehydrogenase flux, which decreased at lower ejection fractions. These results were confirmed using in vitro analysis of enzyme activities and metabolomic profiles of key intermediates. The in vivo decrease in Krebs cycle activity in the 6-week post-MI heart may represent an early maladaptive phase in the metabolic alterations after MI in which reductions in Krebs cycle activity precede a reduction in pyruvate dehydrogenase flux. Changes in mitochondrial metabolism in heart disease are progressive and proportional to the degree of cardiac impairment. © 2014 American Heart Association, Inc.

  5. Brain metabolites in definite amyotrophic lateral sclerosis. A longitudinal proton magnetic resonance spectroscopy study.

    Science.gov (United States)

    Unrath, Alexander; Ludolph, Albert C; Kassubek, Jan

    2007-08-01

    Biomarkers beyond clinical assessment are needed in patients who suffer from amyotrophic lateral sclerosis (ALS). Here, single-voxel proton magnetic resonance spectroscopy ((1)H MRS) of the gray matter of the motor cortex and the white matter including the pyramidal tracts was used to investigate concentrations of N-acetylaspartate (NAA), creatine (Cr), choline (Cho), myoinositol, glutamate, and glutamine in patients with definite ALS in a longitudinal design (three measurements at study inclusion, after 3 and 6 months). A volume-corrected analysis of gray and white matter fractions within the volumes of interest (VOI) was performed for the identification of the absolute metabolite concentrations. The patient group showed a significant decline of the compound NAA over time in the motor cortex areas both of the clinically more and less affected hemisphere between first measurement and month 6 and for the less affected side additionally between first measurement and month 3. For the NAA/(Cr + Cho) ratio, significant decline in the less affected hemisphere was observed from the first measurement to month 3 and to month 6 as well as from month 3 to month 6. In contrast, neither NAA nor the NAA/(Cr + Cho) ratios in the white matter areas showed any significant alterations. All other compounds showed no significant changes over time. In summary, the longitudinal changes of cortical metabolite concentrations in the course of ALS could be assessed by optimized (1)H MRS techniques at group level, so that (1)H MRS parameters, in particular volume-corrected values of NAA in the clinically less affected hemisphere, seem to have the potential to serve as a surrogate marker for monitoring ALS disease progression.

  6. Characterization of iron, manganese, and copper synthetic hydroxyapatites by electron paramagnetic resonance spectroscopy

    Science.gov (United States)

    Sutter, B.; Wasowicz, T.; Howard, T.; Hossner, L. R.; Ming, D. W.

    2002-01-01

    The incorporation of micronutrients (e.g., Fe, Mn, Cu) into synthetic hydroxyapatite (SHA) is proposed for slow release of these nutrients to crops in NASA's Advanced Life Support (ALS) program for long-duration space missions. Separate Fe3+ (Fe-SHA), Mn2+ (Mn-SHA), and Cu2+ (Cu-SHA) containing SHA materials were synthesized by a precipitation method. Electron paramagnetic resonance (EPR) spectroscopy was used to determine the location of Fe3+, Mn2+, and Cu2+ ions in the SHA structure and to identify other Fe(3+)-, Mn(2+)-, and Cu(2+)-containing phases that formed during precipitation. The EPR parameters for Fe3+ (g=4.20 and 8.93) and for Mn2+ (g=2.01, A=9.4 mT, D=39.0 mT and E=10.5 mT) indicated that Fe3+ and Mn2+ possessed rhombic ion crystal fields within the SHA structure. The Cu2+ EPR parameters (g(z)=2.488, A(z)=5.2 mT) indicated that Cu2+ was coordinated to more than six oxygens. The rhombic environments of Fe3+ and Mn2+ along with the unique Cu2+ environment suggested that these metals substituted for the 7 or 9 coordinate Ca2+ in SHA. The EPR analyses also detected poorly crystalline metal oxyhydroxides or metal-phosphates associated with SHA. The Fe-, Mn-, and Cu-SHA materials are potential slow release sources of Fe, Mn, and Cu for ALS and terrestrial cropping systems.

  7. Parkinson's disease and brain mitochondrial dysfunction: a functional phosphorus magnetic resonance spectroscopy study.

    Science.gov (United States)

    Rango, Mario; Bonifati, Cristiana; Bresolin, Nereo

    2006-02-01

    In spite of several evidences for a mitochondrial impairment in Parkinson's disease (PD), so far it has not been possible to show in vivo mitochondrial dysfunction in the human brain of PD patients. The authors used the high temporal and spatial resolution 31 phosphorus magnetic resonance spectroscopy (31P MRS) technique, which they have previously developed in normal subjects and in patients with mitochondrial diseases to study mitochondrial function by observing high-energy phosphates (HEPs) and intracellular pH (pH) in the visual cortex of 20 patients with PD and 20 normal subjects at rest, during, and after visual activation. In normal subjects, HEPs remained unchanged during activation, but rose significantly (by 16%) during recovery, and pH increased during visual activation with a slow return to rest values. In PD patients, HEPs were within the normal range at rest and did not change during activation, but fell significantly (by 36%) in the recovery period; pH did not reveal a homogeneous pattern with a wide spread of values. Energy unbalance under increased oxidative metabolism requirements, that is, the postactivation phase, discloses a mitochondrial dysfunction that is present in the brain of patients with PD even in the absence of overt clinical manifestations, as in the visual cortex. This is in agreement with our previous findings in patients with mitochondrial disease without clinical central nervous system (CNS) involvement. The heterogeneity of the physicochemical environment (i.e., pH) suggests various degrees of subclinical brain involvement in PD. The combined use of MRS and brain activation is fundamental for the study of brain energetics in patients with PD and may prove an important tool for diagnostic purposes and, possibly, to monitor therapeutic interventions.

  8. Localization of the CyanoP binding site on Photosystem II by surface plasmon resonance spectroscopy

    Directory of Open Access Journals (Sweden)

    Kai U Cormann

    2014-11-01

    Full Text Available Photosystem II (PSII, a large multi subunit membrane protein complex localized in the thylakoid membrane of cyanobacteria and chloroplasts, is the only known enzyme that catalyzes the light driven oxidation of water. In addition to the membrane intrinsic part of PSII, efficient oxygen evolution requires soluble protein subunits at its luminal interface. In contrast to the detailed crystal structure of the active cyanobacterial complex the characterization of intermediate PSII species related to its assembly and repair is hampered by their instability or low abundance. As most structural variations of the corresponding PSII species are based on a different set of protein factors bound to the luminal interface of the complex we developed a system for interaction analysis between PSII and its soluble interaction partners based on surface plasmon resonance spectroscopy (SPR. The assay was validated by the correct localization of the extrinsic PSII proteins PsbO, PsbV and PsbU on the luminal PSII surface and used to determine the unknown binding position of CyanoP, the cyanobacterial homolog of higher plant PsbP. The CyanoP binding site was clearly localized in the center of PSII at a position, which is occupied by the PsbO subunit in mature PSII complexes. Consistently, we demonstrate selective binding of CyanoP to an inactive PSII assembly intermediate that lacks the extrinsic subunits PsbO, PsbV and PsbU. These findings suggest, that CyanoP functions in the dynamic lifecycle of PSII, possibly in the association of CP47 and CP43 or in photoactivation of the oxygen-evolving complex (OEC.

  9. Decreased auditory GABA+ concentrations in presbycusis demonstrated by edited magnetic resonance spectroscopy.

    Science.gov (United States)

    Gao, Fei; Wang, Guangbin; Ma, Wen; Ren, Fuxin; Li, Muwei; Dong, Yuling; Liu, Cheng; Liu, Bo; Bai, Xue; Zhao, Bin; Edden, Richard A E

    2015-02-01

    Gamma-aminobutyric acid (GABA) is the main inhibitory neurotransmitter in the central auditory system. Altered GABAergic neurotransmission has been found in both the inferior colliculus and the auditory cortex in animal models of presbycusis. Edited magnetic resonance spectroscopy (MRS), using the MEGA-PRESS sequence, is the most widely used technique for detecting GABA in the human brain. However, to date there has been a paucity of studies exploring changes to the GABA concentrations in the auditory region of patients with presbycusis. In this study, sixteen patients with presbycusis (5 males/11 females, mean age 63.1 ± 2.6 years) and twenty healthy controls (6 males/14 females, mean age 62.5 ± 2.3 years) underwent audiological and MRS examinations. Pure tone audiometry from 0.125 to 8 kHz and tympanometry were used to assess the hearing abilities of all subjects. The pure tone average (PTA; the average of hearing thresholds at 0.5, 1, 2 and 4 kHz) was calculated. The MEGA-PRESS sequence was used to measure GABA+ concentrations in 4 × 3 × 3 cm(3) volumes centered on the left and right Heschl's gyri. GABA+ concentrations were significantly lower in the presbycusis group compared to the control group (left auditory regions: p = 0.002, right auditory regions: p = 0.008). Significant negative correlations were observed between PTA and GABA+ concentrations in the presbycusis group (r = -0.57, p = 0.02), while a similar trend was found in the control group (r = -0.40, p = 0.08). These results are consistent with a hypothesis of dysfunctional GABAergic neurotransmission in the central auditory system in presbycusis and suggest a potential treatment target for presbycusis. Copyright © 2014 Elsevier Inc. All rights reserved.

  10. Change in brain magnetic resonance spectroscopy after treatment during acute HIV infection.

    Directory of Open Access Journals (Sweden)

    Napapon Sailasuta

    Full Text Available Single voxel proton magnetic resonance spectroscopy (MRS can be used to monitor changes in brain inflammation and neuronal integrity associated with HIV infection and its treatments. We used MRS to measure brain changes during the first weeks following HIV infection and in response to antiretroviral therapy (ART.Brain metabolite levels of N-acetyl aspartate (NAA, choline (tCHO, creatine (CR, myoinositol (MI, and glutamate and glutamine (GLX were measured in acute HIV subjects (n = 31 and compared to chronic HIV+individuals (n = 26 and HIV negative control subjects (n = 10 from Bangkok, Thailand. Metabolites were measured in frontal gray matter (FGM, frontal white matter (FWM, occipital gray matter (OGM, and basal ganglia (BG. Repeat measures were obtained in 17 acute subjects 1, 3 and 6 months following initiation of ART.After adjustment for age we identified elevated BG tCHO/CR in acute HIV cases at baseline (median 14 days after HIV infection compared to control (p = 0.0014, as well as chronic subjects (p = 0.0023. A similar tCHO/CR elevation was noted in OGM; no other metabolite abnormalities were seen between acute and control subjects. Mixed longitudinal models revealed resolution of BG tCHO/CR elevation after ART (p = 0.022 with tCHO/CR similar to control subjects at 6 months.We detected cellular inflammation in the absence of measurable neuronal injury within the first month of HIV infection, and normalization of this inflammation following acutely administered ART. Our findings suggest that early ART may be neuroprotective in HIV infection by mitigating processes leading to CNS injury.

  11. Magnetic resonance spectroscopy as a decision tool in multimodality treatment design for localised prostate cancer

    Directory of Open Access Journals (Sweden)

    Giuseppe Sasso

    2011-12-01

    Full Text Available Predicting the outcome of individual prostate adenocarcinoma can be challenging, especially for patients affected by intermediate or high risk, but localised disease. Natural histories of prostate cancers with similar stage and prognostic factors can differ significantly; and an ongoing debate surrounds the optimal treatment choice for men diagnosed with non-metastatic prostate cancer. A variety of effective therapeutic options are available to be used as a sole modality, or in combination, including surgery, external beam radiotherapy, brachytherapy, and endocrine manipulation. Although these treatments have been used routinely for more than 15 years, there is a paucity of data from randomised trials comparing their results. In addition, most treatment techniques have changed dramatically in the last two decades due to the ongoing healthcare technological revolution. The rapid proliferation of new and expensive therapeutic options (i.e. adaptive radiotherapy, focal ablation, etc. promises to minimise treatment related side effects and improve local control, however, there is no uniform consensus. Treatment choice is based on the available prognostic factors and life expectancy, along with patient preference, toxicity profiles, the individual institution’s (and clinician’s experience and resource availability. Unfortunately, our prognostic tools are still limited, as is our ability to precisely predict which subset of patients might benefit from more aggressive therapeutic combinations. Therefore, a significant number of patients receive unnecessary and expensive treatments, whilst others are denied highly technological procedures because of associated resource limitation. This paper aims to analyse the current evidence, cost-effectiveness and controversies, surrounding the nonsurgical treatment of localised prostate cancer, with a focus on radiation and endocrine therapies, and to discuss the role of magnetic resonance spectroscopy, as a

  12. Proton magnetic resonance spectroscopy and single photon emission CT in patients with olivopontocerebellar atrophy

    Energy Technology Data Exchange (ETDEWEB)

    Ikuta, Naomi [Yamaguchi Univ., Ube (Japan). School of Medicine

    1998-04-01

    Using proton magnetic resonance spectroscopy ({sup 1}H-MRS) and single photon emission CT (SPECT), the cerebellum of patients with olivopontocerebellar atrophy (OPCA) and of age-matched control subjects was studied. A spectrum was collected from a 27 cm{sup 3} (3 x 3 x 3 cm) voxel in the cerebellum containing white and gray matters in order to measure the distribution and relative signal intensities of N-acetylaspartate (NAA), creatine (Cre) and choline (Cho). In the cerebellum of the patients with OPCA, mean NAA/Cre ratios for OPCA patients were significantly decreased compared with normal control subjects (OPCA, 1.01{+-}0.247; controls, 1.526{+-}0.144: p<0.001). Mean NAA/Cho ratios for OPCA patients were slightly decreased (OPCA, 1.285{+-}0.228; controls 1.702{+-}0.469: p<0.06). Cho/Cre ratios valued in the cerebellum of OPCA patients were not significantly different from those in normal controls (OPCA, 0.793{+-}0.186; controls, 0.946{+-}0.219). The ratio of RI count in the cerebellum to that in the occipital lobe was significantly decreased in OPCA patients (OPCA, 0.947{+-}0.096; controls, 1.06{+-}0.063: p<0.01). Cerebellar signs were assessed including gait ataxia, limb ataxia, dysarthria, saccadic pursuit, and nystagmus separately or in combination. In patients with more severe ataxic gait and dysarthria, MRS revealed slightly lowered NAA/Cre ratio. There was no significant correlation between NAA/Cre ratio and severity of other clinical signs. The MRS and SPECT findings give a confirmative evidence of hypofunction in cerebellum of patients with OPCA. (author)

  13. Principal and independent component analysis of concomitant functional near infrared spectroscopy and magnetic resonance imaging data

    Science.gov (United States)

    Schelkanova, Irina; Toronov, Vladislav

    2011-07-01

    Although near infrared spectroscopy (NIRS) is now widely used both in emerging clinical techniques and in cognitive neuroscience, the development of the apparatuses and signal processing methods for these applications is still a hot research topic. The main unresolved problem in functional NIRS is the separation of functional signals from the contaminations by systemic and local physiological fluctuations. This problem was approached by using various signal processing methods, including blind signal separation techniques. In particular, principal component analysis (PCA) and independent component analysis (ICA) were applied to the data acquired at the same wavelength and at multiple sites on the human or animal heads during functional activation. These signal processing procedures resulted in a number of principal or independent components that could be attributed to functional activity but their physiological meaning remained unknown. On the other hand, the best physiological specificity is provided by broadband NIRS. Also, a comparison with functional magnetic resonance imaging (fMRI) allows determining the spatial origin of fNIRS signals. In this study we applied PCA and ICA to broadband NIRS data to distill the components correlating with the breath hold activation paradigm and compared them with the simultaneously acquired fMRI signals. Breath holding was used because it generates blood carbon dioxide (CO2) which increases the blood-oxygen-level-dependent (BOLD) signal as CO2 acts as a cerebral vasodilator. Vasodilation causes increased cerebral blood flow which washes deoxyhaemoglobin out of the cerebral capillary bed thus increasing both the cerebral blood volume and oxygenation. Although the original signals were quite diverse, we found very few different components which corresponded to fMRI signals at different locations in the brain and to different physiological chromophores.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2013-06-15

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

  15. Direct rate assessment of laccase catalysed radical formation in lignin by electron paramagnetic resonance spectroscopy.

    Science.gov (United States)

    Munk, Line; Andersen, Mogens Larsen; Meyer, Anne S

    2017-11-01

    Laccases (EC 1.10.3.2) catalyse removal of an electron and a proton from phenolic hydroxyl groups, including phenolic hydroxyls in lignins, to form phenoxy radicals during reduction of O2. We employed electron paramagnetic resonance spectroscopy (EPR) for real time measurement of such catalytic radical formation activity on three types of lignin (two types of organosolv lignin, and a lignin rich residue from wheat straw hydrolysis) brought about by two different fungal laccases, derived from Trametes versicolor (Tv) and Myceliophthora thermophila (Mt), respectively. Laccase addition to suspensions of the individual lignin samples produced immediate time and enzyme dose dependent increases in intensity in the EPR signal with g-values in the range 2.0047-2.0050 allowing a direct quantitative monitoring of the radical formation and thus allowed laccase enzyme kinetics assessment on lignin. The experimental data verified that the laccases acted upon the insoluble lignin substrates in the suspensions. When the action on the lignin substrates of the two laccases were compared on equal enzyme dosage levels (by activity units on syringaldazine) the Mt laccase exerted a significantly faster radical formation than the Tv laccase on all three types of lignin substrates. When comparing the equal laccase dose rates on the three lignin substrates the enzymatic radical formation rate on the wheat straw lignin residue was consistently higher than those of the organosolv lignins. The pH-temperature optimum for the radical formation rate in organosolv lignin was determined by response surface methodology to pH 4.8, 33°C and pH 5.8, 33°C for the Tv laccase and the Mt laccase, respectively. The results verify direct radical formation action of fungal laccases on lignin without addition of mediators and the EPR methodology provides a new type of enzyme assay of laccases on lignin. Copyright © 2017 Elsevier Inc. All rights reserved.

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

    Energy Technology Data Exchange (ETDEWEB)

    Ohtsuki, Takashi, E-mail: ohtsuki@nihs.go.jp [National Institute of Health Sciences, 1-18-1 Kamiyoga, Setagaya-ku, Tokyo 158-8501 (Japan); Sato, Kyoko; Sugimoto, Naoki; Akiyama, Hiroshi; Kawamura, Yoko [National Institute of Health Sciences, 1-18-1 Kamiyoga, Setagaya-ku, Tokyo 158-8501 (Japan)

    2012-07-13

    Highlights: Black-Right-Pointing-Pointer A method using qHNMR was applied and validated to determine SA in processed foods. Black-Right-Pointing-Pointer This method has good accuracy, precision, selectiveness, and linearity. Black-Right-Pointing-Pointer The proposed method is more rapid and simple than the conventional method. Black-Right-Pointing-Pointer We found that the proposed method is reliable for the accurate determination of SA. Black-Right-Pointing-Pointer 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{sup -1} (beverage: 0.013 g kg{sup -1}) were larger than 80%, whereas those for samples spiked at 0.063 g kg{sup -1} (beverage: 0.0063 g kg{sup -1}) were between 56.9 and 83.5%. The limit of quantification was 0.063 g kg{sup -1} for foods (and 0.0063 g kg{sup -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.

  17. Study of nanostructural organization of ionic liquids by electron paramagnetic resonance spectroscopy.

    Science.gov (United States)

    Merunka, Dalibor; Peric, Mirna; Peric, Miroslav

    2015-02-19

    The X-band electron paramagnetic resonance spectroscopy (EPR) of a stable, spherical nitroxide spin probe, perdeuterated 2,2,6,6-tetramethyl-4-oxopiperidine-1-oxyl (pDTO) has been used to study the nanostructural organization of a series of 1-alkyl-3-methylimidazolium tetrafluoroborate ionic liquids (ILs) with alkyl chain lengths from two to eight carbons. By employing nonlinear least-squares fitting of the EPR spectra, we have obtained values of the rotational correlation time and hyperfine coupling splitting of pDTO to high precision. The rotational correlation time of pDTO in ILs and squalane, a viscous alkane, can be fit very well to a power law functionality with a singular temperature, which often describes a number of physical quantities measured in supercooled liquids. The viscosity of the ILs and squalane, taken from the literature, can also be fit to the same power law expression, which means that the rotational correlation times and the ionic liquid viscosities have similar functional dependence on temperature. The apparent activation energy of both the rotational correlation time of pDTO and the viscous flow of ILs and squalane increases with decreasing temperature; in other words, they exhibit strong non-Arrhenius behavior. The rotational correlation time of pDTO as a function of η/T, where η is the shear viscosity and T is the temperature, is well described by the Stokes-Einstein-Debye (SED) law, while the hydrodynamic probe radii are solvent dependent and are smaller than the geometric radius of the probe. The temperature dependence of hyperfine coupling splitting is the same in all four ionic liquids. The value of the hyperfine coupling splitting starts decreasing with increasing alkyl chain length in the ionic liquids in which the number of carbons in the alkyl chain is greater than four. This decrease together with the decrease in the hydrodynamic radius of the probe indicates a possible existence of nonpolar nanodomains.

  18. Magnetic resonance spectroscopy of brain tumors; MR-Spektroskopie bei Hirntumoren

    Energy Technology Data Exchange (ETDEWEB)

    Ditter, P.; Hattingen, E. [Universitaetsklinikum Bonn, FE Neuroradiologie, Radiologische Klinik, Bonn (Germany)

    2017-06-15

    Conventional magnetic resonance imaging (MRI) under consideration of clinical information enables the correct diagnosis and therapy for the majority of cerebral space-occupying lesions. Some important differential diagnoses, e. g. low vs. high-grade tumors, require additional MRI methods. This article critically discusses the importance of magnetic resonance spectroscopy ({sup 1}H-MRS) in brain tumors. The concentration of normal and pathological brain metabolites can be non-invasively measured by {sup 1}H-MRS. It is based on the principle that chemical proton compounds of certain brain metabolites focally attenuate the external magnetic field and change the proton resonance frequency according to typical patterns. In addition, parameter maps of MRS imaging (MRSI) can show the tumor heterogeneity as well as changes in the surrounding brain tissue. In this context, the patterns of N-acetylaspartate, total choline (tCho) and creatine are relatively robust, whereas the patterns of other metabolites, such as myoinositol, glutamate, lactate or lipids greatly depend on the external field strength and echo time. The signal intensity of tCho in vital tumor tissue increases with the WHO grade of the brain tumor, i.e. increases with the level of malignancy. The use of MRSI facilitates the WHO grading of gliomas by determining target points in biopsies. Different distribution patterns and specific metabolite signals enable a better differentiation between abscesses, metastases, central nervous system (CNS) lymphomas and gliomas. The use of {sup 1}H-MRS provides valuable information on the differential diagnosis and graduation of brain tumors; however, so far artefacts, signal strength, parameter selection and a lack of standardization impede the establishment of {sup 1}H-MRS for use in clinical routine diagnostics. (orig.) [German] Die konventionelle MRT ermoeglicht unter Beruecksichtigung klinischer Information bei einem Grossteil zerebraler Raumforderungen die richtige

  19. A study of relaxation mechanisms in the A{sup 2}{Sigma}{sup +} state of nitric oxide by time resolved double resonant polarization spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Stampanoni-Panariello, A.; Bombach, R.; Hemmerling, B.; Hubschmid, W. [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

    1997-06-01

    Double resonant polarization labeling spectroscopy is applied to detect nitric oxide in flames and to characterize rotational energy transfer and orientation changing collisions in its first excited electronic state. (author) 4 figs., 3 refs.

  20. Role of multipolar plasmon resonances during surface-enhanced Raman spectroscopy on Au micro-patches

    DEFF Research Database (Denmark)

    Dowd, Annette; Geisler, Mathias; Zhu, Shaoli

    2016-01-01

    The enhancement of a Raman signal by multipolar plasmon resonances – as opposed to the more common practice of using dipolar resonances – is investigated. A wide range of gold stars, triangles, circles and squares with multipolar resonances in the visible region were designed and then produced...... by electron beam lithography. We used 633 nm excitation and Rhodamine 6G as a probe molecule to confirm that, although the dipolar resonances of these shapes lie well into the infrared, SERS in the visible can still be obtained by coupling to their ‘dark mode’ multipolar resonances. However, the magnitude...

  1. Injury of the ligaments of the knee: Magnetic resonance evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Ahn, Joong Mo; Kang, Heung Sik; Kim, Sung Moon; Seong, Sang Cheol [Seoul National University College of Medicine, Seoul (Korea, Republic of)

    1992-03-15

    To evaluation the value of MR imaging in the examination of ligament injury of the knee, we retrospectively analysed the MR images of 61 injured knees of 60 patients. The presence of tear was determined by arthroscopy in all caes. Anterio/posterior cruciate ligaments(ACL/PCL) were demonstrated by sagittal images. Medial/lateral collateral ligaments(MCL/ LCL) were evaluated on coronal images. The diagnostic accuracy were 91.8%, 96.7% and 100% for ACL, PCL and MCL, respectively. The specificity for the lateral collateral ligament was 100%. It is concluded that magnetic resonance imaging is an accurate method in detecting injury of the ligaments of the knee.

  2. Controlled attenuation parameter and magnetic resonance spectroscopy-measured liver steatosis are discordant in obese HIV-infected adults.

    Science.gov (United States)

    Price, Jennifer C; Dodge, Jennifer L; Ma, Yifei; Scherzer, Rebecca; Korn, Natalie; Tillinghast, Kyle; Peters, Marion G; Noworolski, Susan; Tien, Phyllis C

    2017-09-24

    Hepatic steatosis is common in HIV-infected individuals. Magnetic resonance spectroscopy (MRS) is the preferred noninvasive method for hepatic steatosis measurement but is expensive. Controlled attenuation parameter (CAP) also assesses hepatic steatosis and is conveniently performed concomitantly with transient elastography. We aimed to assess the accuracy of CAP in the setting of HIV infection. Cross-sectional study. CAP and MRS were performed in 82 study participants (39 HIV monoinfected; seven hepatitis C virus (HCV) monoinfected; 21 HIV/HCV coinfected; 15 with neither infection). We used concordance correlation coefficients to compare log-transformed and standardized CAP and MRS values and linear regression to examine factors associated with CAP and MRS-measured hepatic steatosis (MRS-HS). The accuracy of CAP to detect at least mild hepatic steatosis, defined as MRS-liver fat fraction more than 0.05, and the factors associated with discordance between CAP and MRS were evaluated. Overall, CAP-measured hepatic steatosis and MRS-HS correlated moderately well (rc = 0.63; P CAP-measured hepatic steatosis and MRS-HS. Using a validated CAP cut-off of at least 238 dB/m, sensitivity and specificity for at least mild hepatic steatosis were 84% and 75% in the entire cohort; 89% and 80% in the HIV-monoinfected group. Participants with higher body composition parameters were more likely to be misclassified as having hepatic steatosis by CAP. Our findings suggest CAP is an acceptable noninvasive surrogate for hepatic steatosis in HIV-infected individuals but may overestimate hepatic steatosis prevalence, especially in individuals with high BMI. Evaluation of factors that improve CAP accuracy and determination of optimal cut-offs are warranted.

  3. Insula-specific responses induced by dental pain. A proton magnetic resonance spectroscopy study

    Energy Technology Data Exchange (ETDEWEB)

    Gutzeit, A.; Weymarn, C. von; Froehlich, J.M.; Binkert, C.A. [Cantonal Hospital Winterthur, Department of Radiology, Winterthur (Switzerland); Meier, D. [University and ETH Zurich, Institute for Biomedical Engineering, Zurich (Switzerland); Meier, M.L.; Bruegger, M. [University of Zurich, Institute of Psychology, Division Neuropsychology, Zurich (Switzerland); Ettlin, D.A. [University of Zuerich, Center for Dental and Oral Medicine and Cranio-Maxillofacial Surgery, Clinic for Removable Prosthodontics, Masticatory Disorders and Special Care Dentistry, Zuerich (Switzerland); Graf, N. [University Hospital of Zurich, Clinical Trials Center, Center for Clinical Research, Zurich (Switzerland)

    2011-04-15

    To evaluate whether induced dental pain leads to quantitative changes in brain metabolites within the left insular cortex after stimulation of the right maxillary canine and to examine whether these metabolic changes and the subjective pain intensity perception correlate. Ten male volunteers were included in the pain group and compared with a control group of 10 other healthy volunteers. The pain group received a total of 87-92 electrically induced pain stimuli over 15 min to the right maxillary canine tooth. Contemporaneously, they evaluated the subjective pain intensity of every stimulus using an analogue scale. Neurotransmitter changes within the left insular cortex were evaluated by MR spectroscopy. Significant metabolic changes in glutamine (+55.1%), glutamine/glutamate (+16.4%) and myo-inositol (-9.7%) were documented during pain stimulation. Furthermore, there was a significant negative correlation between the subjective pain intensity perception and the metabolic levels of Glx, Gln, glutamate and N-acetyl aspartate. The insular cortex is a metabolically active region in the processing of acute dental pain. Induced dental pain leads to quantitative changes in brain metabolites within the left insular cortex resulting in significant alterations in metabolites. Negative correlation between subjective pain intensity rating and specific metabolites could be observed. (orig.)

  4. In situ monitoring of polymer redox states by resonance µRaman spectroscopy and its applications in polymer modified microfluidic channels

    OpenAIRE

    Logtenberg, Hella; Jellema, Laurens-Jan C.; Lopez-Martinez, Maria J.; Areephong, Jetsuda; Verpoorte, Elisabeth; Feringa, Ben L.; Browne, Wesley R.

    2012-01-01

    We report the application of multi-wavelength resonance Raman (rR) spectroscopy for the characterisation of vinyl-bridged polysexithiophene films formed by electropolymerisation on gold electrodes. Resonance Raman spectroscopy of the neutral, polaronic and bipolaronic states of the polymer were determined by in situ mu Raman spectroelectrochemistry. In particular the differences in the UV/Vis-NIR absorption spectra of the neutral, monopolaronic and bipolaronic states of the polymer allow for ...

  5. Investigating the lignocellulosic composition during delignification using confocal raman spectroscopy, cross-polarization magic angle spinning carbon 13 - nuclear magnetic resonance (CP/MAS 13C- NMR) spectroscopy and atomic force microscopy

    CSIR Research Space (South Africa)

    Chunilall, Viren

    2012-03-01

    Full Text Available spectroscopy, Cross-Polarization Magic Angle Spinning Carbon 13 - Nuclear Magnetic Resonance (CP/MAS 13C-NMR) spectroscopy and Atomic Force Microscopy (AFM) in conjunction with image analysis. The confocal Raman results showed that there were differences...

  6. Investigation of Antioxidant Activity of Pomegranate Juices by Means of Electron Paramagnetic Resonance and UV-Vis Spectroscopy.

    Science.gov (United States)

    Kozik, Violetta; Jarzembek, Krystyna; Jędrzejowska, Agnieszka; Bąk, Andrzej; Polak, Justyna; Bartoszek, Mariola; Pytlakowska, Katarzyna

    2015-01-01

    Pomegranate fruit (Punica granatum L.) is a source of numerous phenolic compounds, and it contains flavonoids such as anthocyanins, anthocyanidins, cyanidins, catechins and other complexes of flavonoids, ellagitannins, and hydrolyzed tannins. Pomegranate juice shows antioxidant, antiproliferative, and anti-atherosclerotic properties. The antioxidant capacity (TEAC) of the pomegranate juices was measured using electron paramagnetic resonance (EPR) spectroscopy and 1,1-diphenyl-2-picrylhydrazyl (DPPH•) as a source of free radicals, and the total phenolic (TP) content was measured using UV-Vis spectroscopy. All the examined pomegranate juices exhibited relatively high antioxidant properties. The TEAC values determined by means of EPR spectroscopy using Trolox (TE) as a free radical scavenger were in the range of 463.12 to 1911.91 μmol TE/100 mL juice. The TP content measured by the Folin-Ciocalteu method, using gallic acid (GA) as a free radical scavenger, widely varied in the investigated pomegranate juice samples and ranged from 1673.62 to 5263.87 mg GA/1 L juice. The strongest antioxidant properties were observed with the fresh pomegranate juices obtained from the fruits originating from Israel, Lebanon, and Azerbaijan. Correlation analysis of numerical data obtained by means of EPR spectroscopy (TEAC) and UV-Vis spectroscopy (TP) gave correlation coefficient (r)=0.90 and determination coefficient (r2)=0.81 (P<0.05).

  7. Magnetic resonance spectroscopy of the normal cerebellum: what degree of variability can be expected?

    Science.gov (United States)

    Currie, Stuart; Hadjivassiliou, Marios; Wilkinson, Iain David; Griffiths, Paul David; Hoggard, Nigel

    2013-04-01

    The objectives of this paper are (a) to establish the reliability of relative metabolite concentrations determined with (1)H-MR spectroscopy of the cerebellum using a method appropriate to the constraints of clinical radiology and (b) to record normal values for metabolites within the cerebellum and to look for differences in metabolite concentrations between the cerebellar hemispheric white matter and the superior vermis. 3-T (1)H-MR spectra were obtained from voxels positioned in the right cerebellar hemispheric white matter and the superior vermis in 55 healthy adults (mean age 41 years, range 20 to 77) using a single voxel PRESS sequence (TR/TE = 2,000/144 ms). One volunteer (male, age 34 years) was examined in six separate sessions over a period of 3 weeks. Reliability of intra- and inter-subject metabolite fitted area ratios was determined by evaluating coefficients of variance (%). Inter- and intra-subject coefficients of variance (%) in metabolite ratios were consistently lower in the vermis (4 to 11.6) compared to those of the hemisphere (7.2 to 14.3). Cho/Cr was significantly higher in the vermis (0.83 ± 0.10) compared to the hemisphere (0.76 ± 0.11) and NAA/Cho was significantly lower in the vermis (1.19 ± 0.12) compared to the hemisphere (1.35 ± 0.16). Low inter- and intra-subject variability can be achieved when using a (1)H-MR spectroscopy technique that is appropriate to the time constraints of clinical radiology. The regional variations of Cho/Cr and NAA/Cho within the hemisphere and vermis should be considered when performing studies of diseases, which may preferentially target a particular cerebellar location.

  8. Hydrogen magnetic resonance spectroscopy follow-up after radiation therapy of human brain cancer: Unexpected inverse correlation between the changes in tumor choline level and post-gadolinium magnetic resonance imaging contrast

    NARCIS (Netherlands)

    P.E. Sijens (Paul); C.J. Vecht (Charles); P.C. Levendag (Peter); P. van Dijk (Pieter); M. Oudkerk (Matthijs)

    1995-01-01

    textabstractRATIONALE AND OBJECTIVES The anatomic and metabolic changes in human brain tumors treated by radiation therapy were compared using gadolinium–enhanced magnetic resonance imaging and hydrogen (1H) magnetic resonance spectroscopy. The study was intended to assess the potential

  9. Multimodal metabolic imaging of cerebral gliomas: positron emission tomography with [18F]fluoroethyl-L-tyrosine and magnetic resonance spectroscopy.

    Science.gov (United States)

    Floeth, Frank Willi; Pauleit, Dirk; Wittsack, Hans-Jörg; Langen, Karl Josef; Reifenberger, Guido; Hamacher, Kurt; Messing-Jünger, Martina; Zilles, Karl; Weber, Friedrich; Stummer, Walter; Steiger, Hans-Jakob; Woebker, Gabriele; Müller, Hans-Wilhelm; Coenen, Heinz; Sabel, Michael

    2005-02-01

    The purpose of this study was to determine the predictive value of [18F]fluoroethyl-L-tyrosine (FET)-positron emission tomography (PET) and magnetic resonance (MR) spectroscopy for tumor diagnosis in patients with suspected gliomas. Both FET-PET and MR spectroscopy analyses were performed in 50 consecutive patients with newly diagnosed intracerebral lesions supposed to be diffuse gliomas on contrast-enhanced MR imaging. Lesion/brain ratios of FET uptake greater than 1.6 were considered positive, that is, indicative of tumor. Results of MR spectroscopy were considered positive when N-acetylaspartate (NAA) was decreased in conjunction with an absolute increase of choline (Cho) and an NAA/Cho ratio of 0.7 or less. An FET lesion/brain ratio, an NAA/Cho ratio, and signal abnormalities on MR images were compared with histological findings in neuronavigated biopsy specimens. The FET lesion/brain ratio and the NAA/Cho ratio were identified as significant independent predictors for the histological identification of tumor tissue. The accuracy in distinguishing neoplastic from nonneoplastic tissue could be increased from 68% with the use of MR imaging alone to 97% with MR imaging in conjunction with FET-PET and MR spectroscopy. Sensitivity and specificity for tumor detection were 100 and 81% for MR spectroscopy and 88 and 88% for FET-PET, respectively. Results of histological studies did not reveal tumor tissue in any of the lesions that were negative on FET-PET and MR spectroscopy. In contrast, a tumor diagnosis was made in 97% of the lesions that were positive with both methods. In patients with intracerebral lesions supposed to be diffuse gliomas on MR imaging, FET-PET and MR spectroscopy analyses markedly improved the diagnostic efficacy of targeted biopsies.

  10. Preparation of a Cobalt(II) Cage: An Undergraduate Laboratory Experiment That Produces a ParaSHIFT Agent for Magnetic Resonance Spectroscopy

    Science.gov (United States)

    Burns, Patrick J.; Tsitovich, Pavel B.; Morrow, Janet R.

    2016-01-01

    Laboratory experiments that demonstrate the effect of paramagnetic complexes on chemical shifts and relaxation times of protons are a useful way to introduce magnetic resonance spectroscopy (MRS) probes or magnetic resonance imaging (MRI) contrast agents. In this undergraduate inorganic chemistry experiment, a paramagnetic Co(II) cage complex is…

  11. Computerized detection of breast cancer using resonance-frequency-based electrical impedance spectroscopy

    Science.gov (United States)

    Gao, Wei; Fan, Ming; Zhao, Weijie; Zheng, Bin; Li, Lihua

    2017-03-01

    This study developed and tested a multi-probe resonance-frequency-based electrical impedance spectroscopy (REIS) system aimed at detection of breast cancer. The REIS system consists of specially designed mechanical supporting device that can be easily lifted to fit women of different height, a seven probe sensor cup, and a computer providing software for system control and management. The sensor cup includes one central probe for direct contact with the nipple, and other six probes uniformly distributed at a distance of 35mm away from the center probe to enable contact with breast skin surface. It takes about 18 seconds for this system to complete a data acquisition process. We utilized this system for examination of breast cancer, collecting a dataset of 289 cases including biopsy verified 74 malignant and 215 benign tumors. After that, 23 REIS based features, including seven frequency, fifteen magnitude features were extracted, and an age feature. To reduce redundancy we selected 6 features using the evolutionary algorithm for classification. The area under a receiver operating characteristic curve (AUC) was computed to assess classifier performance. A multivariable logistic regression method was performed for detection of the tumors. The results of our study showed for the 23 REIS features AUC and ACC, Sensitivity and Specificity of 0.796, 0.727, 0.731 and 0.726, respectively. The AUC and ACC, Sensitivity and Specificity for the 6 REIS features of 0.840, 0.80, 0.703 and 0.833, respectively, and AUC of 0.662 and 0.619 for the frequency and magnitude based REIS features, respectively. The performance of the classifiers using all the 6 features was significantly better than solely using magnitude features (p=3.29e-08) and frequency features (5.61e-07). Smote algorithm was used to expand small samples to balance the dataset, the AUC after data balance of 0.846 increased than the original data classification performance. The results indicated that the REIS system is

  12. Novel use of proton magnetic resonance spectroscopy (1HMRS to non-invasively assess placental metabolism.

    Directory of Open Access Journals (Sweden)

    Fiona C Denison

    Full Text Available Placental insufficiency is a major cause of antepartum stillbirth and fetal growth restriction (FGR. In affected pregnancies, delivery is expedited when the risks of ongoing pregnancy outweigh those of prematurity. Current tests are unable to assess placental function and determine optimal timing for delivery. An accurate, non-invasive test that clearly defines the failing placenta would address a major unmet clinical need. Proton magnetic resonance spectroscopy ((1H MRS can be used to assess the metabolic profile of tissue in-vivo. In FGR pregnancies, a reduction in N-acetylaspartate (NAA/choline ratio and detection of lactate methyl are emerging as biomarkers of impaired neuronal metabolism and fetal hypoxia, respectively. However, fetal brain hypoxia is a late and sometimes fatal event in placental compromise, limiting clinical utility of brain (1H MRS to prevent stillbirth. We hypothesised that abnormal placental (1H MRS may be an earlier biomarker of intrauterine hypoxia, affording the opportunity to optimise timing of delivery in at-risk fetuses.We recruited three women with severe placental insufficiency/FGR and three matched controls. Using a 3T MR system and a combination of phased-array coils, a 20×20×40 mm(1H MRS voxel was selected along the 'long-axis' of the placenta with saturation bands placed around the voxel to prevent contaminant signals. A significant choline peak (choline/lipid ratio 1.35-1.79 was detected in all healthy placentae. In contrast, in pregnancies complicated by FGR, the choline/lipid ratio was ≤0.02 in all placentae, despite preservation of the lipid peak (p<0.001.This novel proof-of-concept study suggests that in severe placental insufficiency/FGR, the observed 60-fold reduction in the choline/lipid ratio by (1H MRS may represent an early biomarker of critical placental insufficiency. Further studies will determine performance of this test and the potential role of 1H-MRS in the in-vivo assessment of

  13. Concurrent diffuse optical tomography, spectroscopy and magnetic resonance imaging of breast cancer

    Science.gov (United States)

    Ntziachristos, Vasilis

    2000-12-01

    Diffuse Optical Tomography (DOT) in the Near Infrared NIR offers the potential to perform non-invasive three- dimensional quantified imaging of large-organs in vivo. The technique targets tissue intrinsic chromophores such as oxy- and deoxy-hemoglobin and the uptake of optical contrast agents. This work considers the DOT application in studying the vascularization, hemoglobin saturation and Indocyanine Green (ICG) uptake of breast tumors in-vivo as measures of angiogenesis, blood vessel permeability and oxygen delivery and consumption. To realize this work an optical tomographer based on the single-photon-counting time- correlated technique was coupled to a Magnetic Resonance Imaging (MRI) scanner. All patients entered the study were also scheduled for biopsy; hence histopathological information was also available as the ``Gold Standard'' for the diagnostic performance. The feasibility of Diffuse Optical Tomography to image tissue in-vivo is demonstrated by direct comparison of contrast-enhanced MRI and DOT images obtained from the same breast under identical geometrical and physiological conditions. Additionally, the effect of tissue optical background heterogeneity on the imaging performance is studied using simulations. We also present optimization schemes that yield superior reconstruction and spectroscopic capacity when probing the intrinsic and extrinsic contrast of highly heterogeneous optical media. The simultaneous examination also pioneers a hybrid diagnostic modality where MRI and image-guided localized diffuse optical spectroscopy (DOS) information are concurrently available. The approach employs the MR structural and functional information as a-priori knowledge and thus improves the quantification ability of the optical method. We have employed DOS and localized DOS to quantify optical properties of tissue in two and three wavelengths and obtain functional properties of malignant, benign and normal breast lesions. Generally, cancers exhibited higher

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

    Science.gov (United States)

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

    2013-03-01

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

  15. Correlating brain blood oxygenation level dependent (BOLD) fractal dimension mapping with magnetic resonance spectroscopy (MRS) in Alzheimer's disease.

    Science.gov (United States)

    Warsi, Mohammed A; Molloy, William; Noseworthy, Michael D

    2012-10-01

    To correlate temporal fractal structure of resting state blood oxygen level dependent (rsBOLD) functional magnetic resonance imaging (fMRI) with in vivo proton magnetic resonance spectroscopy ((1)H-MRS), in Alzheimer's disease (AD) and healthy age-matched normal controls (NC). High temporal resolution (4 Hz) rsBOLD signal and single voxel (left putamen) magnetic resonance spectroscopy data was acquired in 33 AD patients and 13 NC. The rsBOLD data was analyzed using two types of fractal dimension (FD) analysis based on relative dispersion and frequency power spectrum. Comparisons in FD were performed between AD and NC, and FD measures were correlated with (1)H-MRS findings. Temporal fractal analysis of rsBOLD, was able to differentiate AD from NC subjects (P = 0.03). Low FD correlated with markers of AD severity including decreased concentrations of N-acetyl aspartate (R = 0.44, P = 0.015) and increased myoinositol (mI) (R = -0.45, P = 0.012). Based on these results we suggest fractal analysis of rsBOLD could provide an early marker of AD.

  16. Calibration of near infrared spectroscopy for solid fat content of fat blends analysis using nuclear magnetic resonance data

    Energy Technology Data Exchange (ETDEWEB)

    Rodrigues, J.C. [Instituto de Investigacao Cientifica Tropical, Grupo Florestal e dos Produtos Florestais, ISA/DEF, Tapada da Ajuda, 1349-017 Lisbon (Portugal); Nascimento, A.C. [Instituto Superior de Agronomia, DAIAT, Dep. Agro-Industrias, Centro de Estudos Agro-Alimentares, Tapada da Ajuda, 1349-017 Lisbon (Portugal); Alves, A. [Instituto Superior de Agronomia, DEF, Centro de Estudos Florestais, Tapada da Ajuda, 1349-017 Lisbon (Portugal); Osorio, N.M. [Instituto Superior de Agronomia, DAIAT, Dep. Agro-Industrias, Centro de Estudos Agro-Alimentares, Tapada da Ajuda, 1349-017 Lisbon (Portugal); Pires, A.S. [Instituto Superior Tecnico, Centro de Engenharia Biologica e Quimica, Av. Rovisco Pais, 1049-001 Lisbon (Portugal); Gusma o, J.H. [FIMA/VG, Marinhas de Dom Pedro, 2695-361 Santa Iria de Azoia (Portugal); Fonseca, M.M.R. da [Instituto Superior Tecnico, Centro de Engenharia Biologica e Quimica, Av. Rovisco Pais, 1049-001 Lisbon (Portugal); Ferreira-Dias, S. [Instituto Superior de Agronomia, DAIAT, Dep. Agro-Industrias, Centro de Estudos Agro-Alimentares, Tapada da Ajuda, 1349-017 Lisbon (Portugal)]. E-mail: suzanafdias@mail.telepac.pt

    2005-07-15

    The functional properties of fats are determined by the distribution pattern of fatty acid residues in their acylglycerols, which may be modified by ester interchange (transesterification). In the margarine industry, the time course of the transesterification of fat blends is monitored by assaying for the amount of the solid fraction at different temperatures (SFC-solid fat content) currently measured by nuclear magnetic resonance (NMR). The aim of this study was to evaluate the feasibility of near infrared spectroscopy (NIRS) to quantify the SFC of different fat blends using NMR data for calibration. SFC values of 128 samples, consisting of different blends of palm stearin, palm kernel oil and concentrates of triglycerides enriched with {omega}-3 polyunsaturated fatty acids were assayed by NMR prior to (64 samples) and following inorganic (10 samples) or lipase-catalysed transesterification (54 samples). Prior to SFC measurement by NMR, sample preparation takes about 90 min. With NIRS technique, a faster determination is achieved since NIR spectra for SFC estimations are directly obtained on the sample at room temperature. High correlations were obtained for cross-validation of the data estimated by NIRS models and NMR for SFC assays at 10 deg. C (R {sup 2} = 0.91, RMSECV = 2.4), 20 deg. C (R {sup 2} = 0.96, RMSECV 1.7), 30 deg. C (R {sup 2} = 0.96, RMSECV = 1.3) and 35 deg. C (R {sup 2} = 0.96, RMSECV = 1.3) of the different blends tested. The obtained results show that NIRS is a reliable technique to replace NMR for SFC estimation.

  17. Role of diffusion tensor imaging or magnetic resonance spectroscopy in the diagnosis and disability assessment of amyotrophic lateral sclerosis.

    Science.gov (United States)

    Liu, Chanchan; Jiang, Rifeng; Yi, Xiyan; Zhu, Wenzhen; Bu, Bitao

    2015-01-15

    To compare the results of magnetic resonance spectroscopy (MRS) and diffusion tensor imaging (DTI) in amyotrophic lateral sclerosis (ALS) patients. Nineteen ALS patients and thirteen age-matched healthy controls underwent MRS and DTI between October 2013 and July 2014. Fractional anisotropy (FA), apparent diffusion coefficient (ADC), N-acetylaspartate (NAA), choline (Cho), and creatine (Cr) were collected as the quantitative results of the imaging study. The ALS functional rating scale-revised (ALSFRS-R) and disease progression rate were evaluated to assess patients' disability. The imaging study results were compared between ALS patients and healthy controls. The relationship between disability assessment and imaging study results was analyzed. NAA/Cr in the motor cortex and FA in the corticospinal tract (CST) of both sides were significantly lower in patients than controls. There was no significant difference between the two groups in Cho/Cr, tract length, tract volume, ADC or NAA. No relationship was found between ALSFRS-R and FA (r=0.243, p=0.316) in the right CST; NAA (r=0.095, p=0.699) or NAA/Cr (r=0.172, p=0.481) in the left motor cortex; or NAA (r=0.320, p=0.182) or NAA/Cr (r=0.193, p=0.492) in the right motor cortex. There was no relationship between the disease progression rate and FA, NAA, or NAA/Cr on either side. NAA/Cr and FA can help diagnose ALS. Regional brain NAA/Cr and FA values could not assess the ALSFRS-R or disease progression rate. Copyright © 2014 Elsevier B.V. All rights reserved.

  18. Reliability of Calf Bioelectrical Impedance Spectroscopy and Magnetic-Resonance-Imaging-Acquired Skeletal Muscle Hydration Measures in Healthy People

    Directory of Open Access Journals (Sweden)

    Anuradha Sawant

    2013-01-01

    Full Text Available Purpose. The purpose of this study was to investigate the test-retest reliability, relative variability, and agreement between calf bioelectrical impedance-spectroscopy (cBIS acquired extracellular fluid (ECF, intracellular fluid (ICF, total water and the ratio of ECF : ICF, magnetic-resonance-imaging (MRI acquired transverse relaxation times (T2, and apparent diffusion coefficient (ADC of calf muscles of the same segment in healthy individuals. Methods. Muscle hydration measures were collected in 32 healthy individuals on two occasions and analyzed by a single rater. On both occasions, MRI measures were collected from tibialis anterior (TA, medial (MG, and lateral gastrocnemius (LG and soleus muscles following the cBIS data acquired using XiTRON Hydra 4200 BIS device. The intraclass correlation coefficients (ICC2,1, coefficient of variation (CV, and agreement between MRI and cBIS data were also calculated. Results. ICC2,1 values for cBIS, T2, and ADC ranged from 0.56 to 0.92, 0.96 to 0.99, and 0.05 to 0.56, respectively. Relative variability between measures (CV ranged from 14.6 to 25.6% for the cBIS data and 4.2 to 10.0% for the MRI-acquired data. The ratio of ECF : ICF could significantly predict T2 of TA and soleus muscles. Conclusion. MRI-acquired measures of T2 had the highest test-retest reliability of muscle hydration with the least error and variation on repeated testing. Hence, T2 of a muscle is the most reliable and stable outcome measure for evaluating individual muscle hydration.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2010-06-15

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

  20. Simulation of electron spin resonance spectroscopy in diverse environments: An integrated approach

    Science.gov (United States)

    Zerbetto, Mirco; Polimeno, Antonino; Barone, Vincenzo

    2009-12-01

    We discuss in this work a new software tool, named E-SpiReS (Electron Spin Resonance Simulations), aimed at the interpretation of dynamical properties of molecules in fluids from electron spin resonance (ESR) measurements. The code implements an integrated computational approach (ICA) for the calculation of relevant molecular properties that are needed in order to obtain spectral lines. The protocol encompasses information from atomistic level (quantum mechanical) to coarse grained level (hydrodynamical), and evaluates ESR spectra for rigid or flexible single or multi-labeled paramagnetic molecules in isotropic and ordered phases, based on a numerical solution of a stochastic Liouville equation. E-SpiReS automatically interfaces all the computational methodologies scheduled in the ICA in a way completely transparent for the user, who controls the whole calculation flow via a graphical interface. Parallelized algorithms are employed in order to allow running on calculation clusters, and a web applet Java has been developed with which it is possible to work from any operating system, avoiding the problems of recompilation. E-SpiReS has been used in the study of a number of different systems and two relevant cases are reported to underline the promising applicability of the ICA to complex systems and the importance of similar software tools in handling a laborious protocol. Program summaryProgram title: E-SpiReS Catalogue identifier: AEEM_v1_0 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AEEM_v1_0.html Program obtainable from: CPC Program Library, Queen's University, Belfast, N. Ireland Licensing provisions: GPL v2.0 No. of lines in distributed program, including test data, etc.: 311 761 No. of bytes in distributed program, including test data, etc.: 10 039 531 Distribution format: tar.gz Programming language: C (core programs) and Java (graphical interface) Computer: PC and Macintosh Operating system: Unix and Windows Has the code been vectorized or

  1. Double-resonance spectroscopy of InAs/GaAs self-assembled quantum dots

    NARCIS (Netherlands)

    Murdin, B. N.; Hollingworth, A. R.; Barker, J. A.; Clarke, D. G.; Findlay, P. C.; Pidgeon, C. R.; Wells, J. P. R.; Bradley, I. V.; Malik, S.; Murray, R.

    2000-01-01

    We present far-/near-infrared double resonance measurements of self-assembled InAs/GaAs quantum dots. The far-infrared resonance is unambiguously associated with a bound-bound intraband transition in the neutral dots. The results show that the interband photoluminescence (PL) lines originate from

  2. Double resonant absorption measurement of acetylene symmetric vibrational states probed with cavity ring down spectroscopy

    NARCIS (Netherlands)

    Karhu, J.; Nauta, J.; Vainio, M.; Metsala, M.; Hoekstra, S.; Halonen, L.

    2016-01-01

    A novel mid-infrared/near-infrared double resonant absorption setup for studying infrared-inactive vibrational states is presented. A strong vibrational transition in the mid-infrared region is excited using an idler beam from a singly resonant continuous-wave optical parametric oscillator, to

  3. N-acetyl resonances in in vivo and in vitro NMR spectroscopy of cystic ovarian tumors.

    NARCIS (Netherlands)

    Kolwijck, E.; Engelke, U.F.H.; Graaf, M. van der; Heerschap, A.; Blom, H.J.; Hadfoune, M.; Buurman, W.A.; Massuger, L.F.A.G.; Wevers, R.A.

    2009-01-01

    An unassigned and prominent resonance in the region from delta 2.0-2.1 ppm has frequently been found in the in vivo MR spectra of cancer patients. We demonstrated the presence of this resonance with in vivo MRS in the cyst fluid of a patient with an ovarian tumor. (1)H-NMRS on the aspirated cyst

  4. Spectroscopy

    DEFF Research Database (Denmark)

    Berg, Rolf W.

    This introductory booklet covers the basics of molecular spectroscopy, infrared and Raman methods, instrumental considerations, symmetry analysis of molecules, group theory and selection rules, as well as assignments of fundamental vibrational modes in molecules.......This introductory booklet covers the basics of molecular spectroscopy, infrared and Raman methods, instrumental considerations, symmetry analysis of molecules, group theory and selection rules, as well as assignments of fundamental vibrational modes in molecules....

  5. Magnetic resonance spectroscopy features of normal-appearing white matter in patients with acute brucellosis

    Energy Technology Data Exchange (ETDEWEB)

    Kayabas, Uner [Department of Infectious Disease and Clinical Microbiology, Inonu University, Medical Faculty, TR-44280 Malatya (Turkey)], E-mail: ukayabas@inonu.edu.tr; Alkan, Alpay; Firat, Ahmet Kemal; Karakas, Hakki Muammer [Department of Radiology, Inonu University, Medical Faculty, TR-44280 Malatya (Turkey); Bayindir, Yasar; Yetkin, Funda [Department of Infectious Disease and Clinical Microbiology, Inonu University, Medical Faculty, TR-44280 Malatya (Turkey)

    2008-03-15

    We aimed to evaluate whether the subtle metabolic cerebral changes are present in normal-appearing white matter on conventional MRI, in patients with acute brucellosis, by using MR spectroscopy (MRS). Sixteen patients with acute brucellosis and 13 healthy control subjects were investigated with conventional MRI and single-voxel MRS. Voxels were placed in normal-appearing parietal white matter (NAPWM). N-Acetyl aspartate (NAA)/creatine (Cr) and choline (Cho)/Cr ratios were calculated. There was no significant difference between the study subjects and the control group in NAA/Cr ratios obtained from NAPWM. However, the Cho/Cr ratios were significantly higher in patients with acute brucellosis compared to controls (p = 0.01). MRS revealed metabolic changes in normal-appearing white matter of patients with brucellosis. Brucellosis may cause subtle cerebral alterations, which may only be discernible with MRS. Increased Cho/Cr ratio possibly represents an initial phase of inflammation and/or demyelination process of brucellosis.

  6. 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.

  7. Hyperfine interaction of Er3+ ions in Y2SiO5 : An electron paramagnetic resonance spectroscopy study

    Science.gov (United States)

    Guillot-Noël, O.; Goldner, Ph.; Du, Y. Le; Baldit, E.; Monnier, P.; Bencheikh, K.

    2006-12-01

    Electron paramagnetic resonance (EPR) spectroscopy of rare earth ions in crystals is a powerful tool to analyze the hyperfine structure of the rare earth ground state. This can be useful for coherent spectroscopy and quantum information applications where the hyperfine structure of the electronic levels is used. In this work, we give a detailed analysis of the hyperfine structure of the ground state [I15/24(0)] of Er3+ ions in Y2SiO5 . The electronic Zeeman, hyperfine, and quadrupole matrices are obtained from angular variations of the magnetic field in three orthogonal crystal planes. An excellent agreement is obtained between experimental and simulated magnetic field positions and relative intensities of EPR lines.

  8. Use of a Continuous Wave Laser and Pockels Cell for Sensitive High-Resolution Collinear Resonance Ionization Spectroscopy

    Science.gov (United States)

    de Groote, R. P.; Budinčević, I.; Billowes, J.; Bissell, M. L.; Cocolios, T. E.; Farooq-Smith, G. J.; Fedosseev, V. N.; Flanagan, K. T.; Franchoo, S.; Garcia Ruiz, R. F.; Heylen, H.; Li, R.; Lynch, K. M.; Marsh, B. A.; Neyens, G.; Rossel, R. E.; Rothe, S.; Stroke, H. H.; Wendt, K. D. A.; Wilkins, S. G.; Yang, X.

    2015-09-01

    New technical developments have led to a 2 orders of magnitude improvement of the resolution of the collinear resonance ionization spectroscopy (CRIS) experiment at ISOLDE, CERN, without sacrificing the high efficiency of the CRIS technique. Experimental linewidths of 20(1) MHz were obtained on radioactive beams of francium, allowing us for the first time to determine the electric quadrupole moment of the short lived [t1 /2=22.0 (5 ) ms ] 219Fr Qs=-1.21 (2 ) eb , which would not have been possible without the advantages offered by the new method. This method relies on a continuous-wave laser and an external Pockels cell to produce narrow-band light pulses, required to reach the high resolution in two-step resonance ionization. Exotic nuclei produced at rates of a few hundred ions/s can now be studied with high resolution, allowing detailed studies of the anchor points for nuclear theories.

  9. Surface-enhanced resonance Raman scattering spectroscopy applied to phytochrome and its model compounds. 1. Biliverdin photoisomers

    Energy Technology Data Exchange (ETDEWEB)

    Holt, R.E.; Farrens, D.L.; Song, Pillsoon; Cotton, T.M. (Univ. of Nebraska, Lincoln (USA))

    1989-12-20

    The application of surface-enhanced resonance Raman scattering (SERRS) spectroscopy to the analysis of the configuration of biliverdin dimethyl ester (BVDE) is reported. SERRS spectra obtained by adsorption of the compounds onto an electrochemically roughened silver electrode and recorded at 7 K were intense and free of significant photodegradation. The similarity of the SERRS and resonance Raman (RR) spectra obtained under identical conditions suggests that no perturbation of the electronic structure of the BVDE occurs upon interaction with the silver surface, and that the distribution of conformers comprising the BVDE solution is not changed. SERRS spectra of the deuterated and monoprotonated Z,Z,Z isomer are also presented. To investigate the influence of configuration upon the Raman spectrum we have synthesized and purified the E,Z,A, and Z,Z,E isomers of BVDE. Excellent SERRS spectra were obtained from the solutions of the compounds eluted directly from the TLC plates.

  10. Resonance ionization spectroscopy in dysprosium. Excitation scheme development and re-determination of the first ionization potential

    Science.gov (United States)

    Studer, D.; Dyrauf, P.; Naubereit, P.; Heinke, R.; Wendt, K.

    2017-11-01

    We report on resonance ionization spectroscopy (RIS) of high-lying energy levels in dysprosium. We developed efficient excitation schemes and re-determined the first ionization potential (IP) via analysis of Rydberg convergences. For this purpose both two- and three-step excitation ladders were investigated. An overall ionization efficiency of 25(4) % could be demonstrated in the RISIKO mass separator of Mainz University, using a three-step resonance ionization scheme. Moreover, an extensive analysis of the even-parity 6s ns- and 6s nd-Rydberg-series convergences, measured via two-step excitation was performed. To account for strong perturbations in the observed s-series, the approach of multichannel quantum defect theory (MQDT) was applied. Considering all individual series limits we extracted an IP-value of 47901.76(5) cm-1, which agrees with the current literature value of 47901.7(6) cm-1, but is one order of magnitude more precise.

  11. Quantification of N-Acetyl Aspartyl Glutamate in Human Brain using Proton Magnetic Resonance Spectroscopy at 7 T

    Science.gov (United States)

    Elywa, M.

    2015-07-01

    The separation of N-acetyl aspartyl glutamate (NAAG) from N-acetyl aspartate (NAA) and other metabolites, such as glutamate, by in vivo proton magnetic resonance spectroscopy at 7 T is described. This method is based on the stimulated echo acquisition mode (STEAM), with short and long echo time (TE) and allows quantitative measurements of NAAG in the parietal and pregenual anterior cingulate cortex (pgACC) of human brain. Two basesets for the LCModel have been established using nuclear magnetic resonance simulator software (NMR-SIM). Six healthy volunteers (age 25-35 years) have been examined at 7 T. It has been established that NAAG can be separated and quantified in the parietal location and does not get quantified in the pgACC location when using a short echo time, TE = 20 ms. On the other hand, by using a long echo time, TE = 74 ms, NAAG can be quantified in pgACC structures.

  12. Resolution performance of the fast Pade transform: Potential advantages for magnetic resonance spectroscopy in ovarian cancer diagnostics

    Energy Technology Data Exchange (ETDEWEB)

    Belkic, Karen [Department of Oncology/Pathology, Karolinska Institute, Stockholm (Sweden); Institute for Prevention Research, University of Southern California Keck School of Medicine, Los Angeles, CA (United States)], E-mail: Karen.Belkic@ki.se

    2007-10-01

    We examine the resolution performance of the fast Pade transform (FPT) applied to theoretically generated (synthesized) noiseless time signals that are reminiscent of in vitro magnetic resonance spectroscopy (MRS) data as encoded from benign and malignant ovarian cyst fluid at strong magnetic fields. All the input spectral parameters were reconstructed exactly by the FPT using only N/16=64 signal points out of N=1024 sampled data. The resulting Pade absorption spectra exhibit all the unequivocally resolved metabolites that are inherent in the input time signal. The present study reveals the potential of the FPT to reliably as well as accurately quantify and split apart closely lying resonances with a very small number of signal points, over two orders of magnitude fewer than with the conventional fast Fourier transform. These features of the FPT could be of potential benefit for ovarian cancer diagnostics via MRS.

  13. 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).

  14. Metabolic profiling of heat or anoxic stress in mouse C2C12 myotubes using multinuclear magnetic resonance spectroscopy

    DEFF Research Database (Denmark)

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

    2010-01-01

    In the present study, the metabolic effects of heat and anoxic stress in myotubes from the mouse cell line C2C12 were investigated by using a combination of (13)C, (1)H, and (31)P nuclear magnetic resonance (NMR) spectroscopy and enrichment with [(13)C]-glucose. Both the (13)C and the (1)H NMR...... spectra showed reduced levels of the amino acids alanine, glutamate, and aspartate after heat or anoxic stress. The decreases were smallest at 42 degrees C, larger at 45 degrees C, and most pronounced after anoxic conditions. In addition, in both the (1)H and the (31)P NMR spectra, decreases in the high...

  15. Monitoring the temperature-dependent elastic and anelastic properties in isotropic polycrystalline ice using resonant ultrasound spectroscopy

    Directory of Open Access Journals (Sweden)

    M. J. Vaughan

    2016-11-01

    calibration of active and passive seismic data gathered in the field. The elastic properties and anelastic quality factor Q in laboratory-manufactured polycrystalline isotropic ice cores decrease (reversibly with increasing temperature, but compressional-wave speed and attenuation prove most sensitive to temperature, indicative of pre-melting of the ice. This method of resonant ultrasound spectroscopy can be deployed in the field, for those situations where shipping samples is difficult (e.g. remote locations, or where the properties of ice change rapidly after extraction (e.g. in the case of sea ice.

  16. Raman spectroscopy: a novel experimental approach to evaluating renal tumours.

    Science.gov (United States)

    Bensalah, Karim; Fleureau, Julien; Rolland, Denis; Lavastre, Olivier; Rioux-Leclercq, Nathalie; Guillé, François; Patard, Jean-Jacques; Senhadji, Lotfi; de Crevoisier, Renaud

    2010-10-01

    New optical techniques of spectroscopy have shown promising results in the evaluation of solid tumours. To evaluate the potential of Raman spectroscopy (RS) to assess renal tumours at surgery. Over a 5-mo period, Raman optical spectra were prospectively acquired on surgical renal specimens removed due to suspicion of cancer. Raman measures were normalised to ensure comparison between spectra. A lower resolution signal was computed using a wavelet decomposition procedure to diminish the size of the signal and exploit the complete spectrum. A support vector machine (SVM) with a linear kernel and a sequential minimal optimisation solver was applied. A leave-one-out cross-validation technique was used to train and test the SVM. There were 36 patients with 34 malignant tumours (27 clear-cell, 6 papillary, and 1 chromophobe) and 2 benign (1 oncocytoma and 1 metanephric cyst) tumours. A total of 241 analysable Raman spectra were obtained. The SVM was able to classify tumoural and normal tissue with an accuracy of 84% (sensitivity 82%, specificity 87%). High-grade and low-grade tumours were differentiated with a precision of 82% (sensitivity 84%, specificity 80%). Histologic subtype could be categorised with an accuracy of 93% (sensitivity 96%, specificity 87%). SVM could not be applied to classify benign and malignant tumours because of the restricted number of benign spectra. RS can accurately differentiate normal and tumoural renal tissue, low-grade and high-grade renal tumours, and histologic subtype of renal cell carcinoma. Larger prospective studies are needed to confirm these preliminary data. Copyright 2010 European Association of Urology. Published by Elsevier B.V. All rights reserved.

  17. Static and dynamic strain coupling behaviour of ferroic and multiferroic perovskites from resonant ultrasound spectroscopy

    Science.gov (United States)

    Carpenter, M. A.

    2015-07-01

    Resonant ultrasound spectroscopy (RUS) provides a window on the pervasive influence of strain coupling at phase transitions in perovskites through determination of elastic and anelastic relaxations across wide temperature intervals and with the application of external fields. In particular, large variations of elastic constants occur at structural, ferroelectric and electronic transitions and, because of the relatively long interaction length provided by strain fields in a crystal, Landau theory provides an effective formal framework for characterizing their form and magnitude. At the same time, the Debye equations provide a robust description of dynamic relaxational processes involving the mobility of defects which are coupled with strain. Improper ferroelastic transitions driven by octahedral tilting in KMnF3, LaAlO3, (Ca,Sr)TiO3, Sr(Ti,Zr)O3 and BaCeO3 are accompanied by elastic softening of tens of % and characteristic patterns of acoustic loss due to the mobility of twin walls. RUS data for ferroelectrics and ferroelectric relaxors, including BaTiO3, (K,Na)NbO3,Pb(Mg1/3Nb2/3)O3 (PMN), Pb(Sc1/2Ta1/2)O3 (PST), (Pb(Zn1/3Nb2/3)O3)0.955(PbTiO3)0.045 (PZN-PT) and (Pb(In1/2Nb1/2)O3)0.26(Pb(Mg1/3Nb2/3)O3)0.44(PbTiO3)0.30 (PIN-PMN-PT) show similar patterns of softening and attenuation but also have precursor softening associated with the development of polar nano regions. Defect-induced ferroelectricity occurs in KTaO3, without the development of long range ordering. By way of contrast, spin-lattice coupling is much more variable in strength, as reflected in a greater range of softening behaviour for Pr0.48Ca0.52MnO3 and Sm0.6Y0.4MnO3 as well as for the multiferroic perovskites EuTiO3,BiFeO3, Bi0.9Sm0.1FeO3, Bi0.9Nd0.1FeO3, (BiFeO3)0.64(CaFeO2.5)0.36, (Pb(Fe0.5Ti0.5)O3)0.4(Pb(Zr0.53Ti0.47)O3)0.6. A characteristic feature of transitions in which there is a significant Jahn-Teller component is softening as the transition point is approached from above, as illustrated by

  18. Resonant soft X-ray emission spectroscopy of vanadium oxides andrelated compounds

    Energy Technology Data Exchange (ETDEWEB)

    Schmitt, Thorsten [Uppsala Univ. (Sweden)

    2004-01-01

    In today's information world, bits of data are processed by semiconductor chips, and stored in the magnetic disk drives. But tomorrow's information technology may see magnetism (spin) and semiconductivity (charge) combined in one ''spintronic'' device that exploits both charge and ''spin'' to carry data (the best of two worlds). Spintronic devices such as spin valve transistors, spin light emitting diodes, non-volatile memory, logic devices, optical isolators and ultra-fast optical switches are some of the areas of interest for introducing the ferromagnetic properties at room temperature in a semiconductor to make it multifunctional. The potential advantages of such spintronic devices will be higher speed, greater efficiency, and better stability at a reduced power consumption. This Thesis contains two main topics: In-depth understanding of magnetism in Mn doped ZnO, and our search and identification of at least six new above room temperature ferromagnetic semiconductors. Both complex doped ZnO based new materials, as well as a number of nonoxides like phosphides, and sulfides suitably doped with Mn or Cu are shown to give rise to ferromagnetism above room temperature. Some of the highlights of this work are discovery of room temperature ferromagnetism in: (1) ZnO:Mn (paper in Nature Materials, Oct issue, 2003); (2) ZnO doped with Cu (containing no magnetic elements in it); (3) GaP doped with Cu (again containing no magnetic elements in it); (4) Enhancement of Magnetization by Cu co-doping in ZnO:Mn; and (5) CdS doped with Mn, and a few others not reported in this thesis. We discuss in detail the first observation of ferromagnetism above room temperature in the form of powder, bulk pellets, in 2-3 μm thick transparent pulsed laser deposited films of the Mn (< 4 at.%) doped ZnO. High-resolution transmission electron microscopy (HRTEM) and electron energy loss spectroscopy (EELS) spectra recorded from 2 to 200nm

  19. An Investigation of the Potential of 31-Phosphorus Nuclear Magnetic Resonance Spectroscopy to Predict Radiation Sensitivity

    Science.gov (United States)

    1988-01-01

    adenine triphosphate (NTP). The PME resonance originates primarily from phosphorylethanolamine (PE) and phosphorylcholine (PC). The phosphate diester (PDE...1985. 17. Gyulai, L., Bolinger, L., Leigh, J. S., Jr., Barlow, C., and Chance, B. Phosphorylethanolamine -the major constituent of the

  20. Resonance

    DEFF Research Database (Denmark)

    Petersen, Nils Holger

    2014-01-01

    A chapter in a book about terminology within the field of medievalism: the chapter discusses the resonance of medieval music and ritual in modern (classical) music culture and liturgical practice.......A chapter in a book about terminology within the field of medievalism: the chapter discusses the resonance of medieval music and ritual in modern (classical) music culture and liturgical practice....

  1. The Condition for Universality at Resonance and Direct Measurement of Pair Wavefunctions Using rf Spectroscopy

    OpenAIRE

    Diener, Roberto B.; Ho, Tin-Lun

    2004-01-01

    We show that when the Fermi energy of a Fermi gas is much smaller than the intrinsic energy width of a Fashbach resonance, the system behaves like a Fermi gas interacting with contact potential. This in turn implies universality at resonance, and large fermionic pairs in the strongly interacting regime. The recent experiments of JILA (PRL. 92, 040403 (2004)) and MIT (PRL. 92, 120403 (2004)) turn out to be deep inside this universal regime, which explains the perfect fit of these experiments b...

  2. Cross-Polarized Surface-Enhanced Infrared Spectroscopy by Fano-Resonant Asymmetric Metamaterials

    OpenAIRE

    Ishikawa, Atsushi; Hara, Shuhei; Tanaka, Takuo; Hayashi, Yasuhiko; Tsuruta, Kenji

    2017-01-01

    Plasmonic metamaterials have overcome fundamental limitations in conventional optics by their capability to engineer material resonances and dispersions at will, holding great promise for sensing applications. Recent demonstrations of metamaterial sensors, however, have mainly relied on their resonant nature for strong optical interactions with molecules, but few examples fully exploit their functionality to manipulate the polarization of light. Here, we present cross-polarized surface-enhanc...

  3. Spectroscopy of high lying resonances in 9Be produced with radioactive 8Li beams

    Directory of Open Access Journals (Sweden)

    Lépine-Szily A.

    2014-04-01

    Full Text Available We present the results of the 8Li(p,α5He and 8Li(p,p8Li reactions measured at the RIBRAS (Radioactive Ion Beams in Brazil system. The experiment was realized in inverse kinematics using a thick [CH2]n polyethylene target and an incident 8Li beam, produced by RIBRAS. Using the thick target method, the complete excitation function could be measured between Ecm = 0.2 − 2.1 MeV, which includes the Gamow peak energy region. The excitation function of the 8Li(p,α5He reaction, populating resonances between 16.888 and 19.0 MeV in 9Be, was obtained[1] and the resonances were fitted using R-matrix calculations. This study shed light on spins, parities, partial widths and isospin values of high lying resonances in 9Be. The measurement of the resonant elastic scattering 8Li(p,p8Li populating resonances in the same energy region can constrain the resonance parameters. Preliminary results of the elastic scattering are also presented.

  4. UV-Vis Ratiometric Resonance Synchronous Spectroscopy for Determination of Nanoparticle and Molecular Optical Cross Sections.

    Science.gov (United States)

    Nettles, Charles B; Zhou, Yadong; Zou, Shengli; Zhang, Dongmao

    2016-03-01

    Demonstrated herein is a UV-vis Ratiometric Resonance Synchronous Spectroscopic (R2S2, pronounced as "R-two-S-two" for simplicity) technique where the R2S2 spectrum is obtained by dividing the resonance synchronous spectrum of a NP-containing solution by the solvent resonance synchronous spectrum. Combined with conventional UV-vis measurements, this R2S2 method enables experimental quantification of the absolute optical cross sections for a wide range of molecular and nanoparticle (NP) materials that range optically from pure photon absorbers or scatterers to simultaneous photon absorbers and scatterers, simultaneous photon absorbers and emitters, and all the way to simultaneous photon absorbers, scatterers, and emitters in the UV-vis wavelength region. Example applications of this R2S2 method were demonstrated for quantifying the Rayleigh scattering cross sections of solvents including water and toluene, absorption and resonance light scattering cross sections for plasmonic gold nanoparticles, and absorption, scattering, and on-resonance fluorescence cross sections for semiconductor quantum dots (Qdots). On-resonance fluorescence quantum yields were quantified for the model molecular fluorophore Eosin Y and fluorescent Qdots CdSe and CdSe/ZnS. The insights and methodology presented in this work should be of broad significance in physical and biological science research that involves photon/matter interactions.

  5. Spectroscopy of high lying resonances in {sup 9}Be produced with radioactive {sup 8}Li beams

    Energy Technology Data Exchange (ETDEWEB)

    Lepini-Szily, A.; Leistenschneider, E.; Lichtenthäler, R.; Guimaraes, V.; Condori, R. Pampa; Scarduelli, V.; Rossi, E.; Zagatto, V.A.; Aguiar, V.A.P.; Duarte, J., E-mail: alinka@if.usp.br [Universidade de Sao Paulo (USP), Sao Paulo, SP (Brazil). Instituto de Fisica; Mendes Junior, D.R.; Faria, P.N. de; Santos, H. [Universidade Federal Fluminense (UFF), Niteroi, RJ (Brazil). Instituto de Fisica; Descouvemont, P. [Physique Nucleaire Theorique et Physique Mathematique, Universite Libre de Bruxelles (ULB), Brussels (Belgium); Barioni, A. [Universidade Federal da Bahia (UFBA), Salvador, BA (Brazil); Pires, K.C.C. [Universidade Tecnologica Federal do Parana (UFTPR), Cornelio Procopio, PR (Brazil); Morcelle, V. [Universidade Federal de Itajuba (UNIFEI), Itabira, MG (Brazil); Moraes, M.C. [Centro Brasileiro de Pesquisas Fisicas (CBPF), Rio de Janeiro, RJ (Brazil); Britos, T.; Assuncao, M. [Universidade Federal de Sao Paulo (UNIFESP), Diadema, SP (Brazil); Zamora, J.C. [Technische Universität Darmstadt, (Germany); Shorto, J.M.B. [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2014-07-01

    We present the results of the {sup 8}Li(p,α){sup 5}He and {sup 8}Li(p,p){sup 8}Li reactions measured at the RIBRAS (Radioactive Ion Beams in Brazil) system. The experiment was realized in inverse kinematics using a thick [CH{sub 2}]{sub n} polyethylene target and an incident {sup 8}Li beam, produced by RIBRAS. Using the thick target method, the complete excitation function could be measured between E{sub cm} = 0.2 - 2.1 MeV, which includes the Gamow peak energy region. The excitation function of the {sup 8}Li(p,α){sup 5}He reaction, populating resonances between 16.888 and 19.0 MeV in {sup 9}Be, was obtained[1] and the resonances were fitted using R-matrix calculations. This study shed light on spins, parities, partial widths and isospin values of high lying resonances in {sup 9}Be. The measurement of the resonant elastic scattering {sup 8}Li(p,p){sup 8}Li populating resonances in the same energy region can constrain the resonance parameters. Preliminary results of the elastic scattering are also presented. (author)

  6. Oxidative stress markers and phosphorus magnetic resonance spectroscopy in a patient with GLUT1 deficiency treated with modified Atkins diet.

    Science.gov (United States)

    Kitamura, Yuri; Okumura, Akihisa; Hayashi, Masaharu; Mori, Harushi; Takahashi, Satoru; Yanagihara, Keiko; Miyata, Rie; Tanuma, Naoyuki; Mimaki, Takashi; Abe, Shinpei; Shimizu, Toshiaki

    2012-05-01

    Glucose transporter type 1 deficiency syndrome is an inborn error of glucose transport across blood-tissue barriers, and the modified Atkins diet is an effective and well-tolerated treatment. To investigate the effects of the modified Atkins diet, we examined the cerebrospinal fluid markers and performed phosphorus magnetic resonance spectroscopy in a patient with glucose transporter type 1 deficiency syndrome before and after the modified Atkins diet. Cerebrospinal fluid levels of the oxidative stress markers, 8-hydroxy-2'-deoxyguanosine and hexanoyl-lysine adduct, were markedly increased above the cutoff index and were normalized 18 months after the modified Atkins diet. Phosphorus magnetic resonance spectroscopy measurements showed 18% increase of PCr/γ-ATP ratio after the modified Atkins diet. These results suggest that the modified Atkins diet may reduce oxidative stress in the brain and improve energy reserve capacity, which is important in sustaining electrophysiological activities essential for performing brain functions. Copyright © 2011 The Japanese Society of Child Neurology. Published by Elsevier B.V. All rights reserved.

  7. Resonant x-ray emission spectroscopy of liquid water: novel instrumentation, high resolution, and the"map" approach

    Energy Technology Data Exchange (ETDEWEB)

    Weinhardt, L.; Fuchs, O.; Blum, M.; B& #228; r, M.; Weigand, M.; Denlinger, J.D.; Zubavichus, Y.; Zharnikov, M.; Grunze, M.; Heske, C.; Umbach, E.

    2008-06-17

    Techniques to study the electronic structure of liquids are rare. Most recently, resonant x-ray emission spectroscopy (XES) has been shown to be an extremely versatile spectroscopy to study both occupied and unoccupied electronic states for liquids in thermodynamic equilibrium. However, XES requires high-brilliance soft x-ray synchrotron radiation and poses significant technical challenges to maintain a liquid sample in an ultra-high vacuum environment. Our group has therefore developed and constructed a novel experimental setup for the study of liquids, with the long-term goal of investigating the electronic structure of biological systems in aqueous environments. We have developed a flow-through liquid cell in which the liquid is separated from vacuum by a thin Si3N4 or SiC window and which allows a precise control of temperature. This approach has significant advantages compared to static liquids cells used in the past. Furthermore, we have designed a dedicated high-transmission, high-resolution soft x-ray spectrometer. The high transmission makes it possible to measure complete resonant XES"maps" in less than an hour, giving unprecedented detailed insight into the electronic structure of the investigated sample. Using this new equipment we have investigated the electronic structure of liquid water. Furthermore, our XES spectra and maps give information about ultra-fast dissociation on the timescale of the O 1s core hole lifetime, which is strongly affected by the initial state hydrogen bonding configuration.

  8. Semi-quantitative analysis of indigo carmine, using silver colloids, by surface enhanced resonance Raman spectroscopy (SERRS)

    Science.gov (United States)

    Shadi, I. T.; Chowdhry, B. Z.; Snowden, M. J.; Withnall, R.

    2003-08-01

    The application of surface enhanced resonance Raman spectroscopy (SERRS) to the semi-quantitative analysis of the dye, indigo carmine, has been examined using citrate-reduced silver colloids. Good linear correlations are observed for the dye band at 1580 cm -1 in the concentration range 10 -7-10 -5 and 10 -9-10 -5 mol dm -3, using laser exciting wavelengths of 514.5 [( R=0.9983)] and 632.8 nm [( R=0.9978)], respectively. At concentrations of dye above 10 -6 M the concentration dependence of the SERRS signals is non-linear due to the coverage of the surface of the colloidal particles by the dye being in excess of a full monolayer. At concentrations above 10 -6 M resonance Raman spectroscopy (RRS) can be employed for the quantitative analysis of the dye. An internal standard was used and a good linear correlation ( R=0.997) was observed for the dependence of dye signal intensities at 1580 cm -1 in the concentration range 10 -5-10 -4 M using a laser exciting wavelength of 514.5 nm. The limits of detection of indigo carmine by SERRS (514.5 nm), SERRS (632.8 nm) and solution RRS (514.5 nm) are found to be 0.9, 1 and 38 ppm, respectively.

  9. Evaluation of muscle injury using magnetic resonance imaging

    Science.gov (United States)

    LeBlanc, A. D.; Jaweed, M.; Evans, H.

    1993-01-01

    The objective of this study was to investigate spin echo T2 relaxation time changes in thigh muscles after intense eccentric exercise in healthy men. Spin echo and calculated T2 relaxation time images of the thighs were obtained on several occasions after exercise of one limb; the contralateral limb served as control. Muscle damage was verified by elevated levels of serum creatine kinase (CK). Thirty percent of the time no exercise effect was discernible on the magnetic resonance (MR) images. In all positive MR images (70%) the semitendinosus muscle was positive, while the biceps femoris, short head, and gracilis muscles were also positive in 50% and 25% of the total cases, respectively. The peak T2 relaxation time and serum CK were correlated (r = 0.94, pmuscle T2 relaxation time and serum CK were similar, although T2 relaxation time remained positive after serum CK returned to background levels. We conclude that magnetic resonance imaging can serve as a useful tool in the evaluation of eccentric exercise muscle damage by providing a quantitative indicator of damage and its resolution as well as the specific areas and muscles.

  10. UV photostability of insect repellents evaluated through Raman spectroscopy

    Science.gov (United States)

    Bório, Viviane G.; Fernandes, Adjaci U.; Silveira, Landulfo

    2016-02-01

    The use of insect repellents either indoors or at places with incidence of solar radiation has been common due to dengue epidemics in Brazil. The lack of studies on the photostability of these substances has motivated this study, where the main goal was to verify the photostability and photodegradation of some of the commercially insect repellents available under the simulated ultraviolet (UV) radiation, by evaluating the molecular changes using dispersive Raman spectroscopy (830 nm excitation). A laboratory-made chamber was used for irradiating the repellents, where UV-A + UV-B radiations (UV-A: 5.5 mW/cm2 and UV-B 1.5 mW/cm2) can be obtained. The chamber internal temperature did not exceed 31 °C during experiments. The compounds n,n-diethyl-m-toluamide (DEET), IR-3535, andiroba and citronella oils, used as active ingredients in insect repellents, and commercial formula containing DEET (14.5% in ethanol and isopropyl myristate) and IR-3535 (16% in carbopol) were continuously irradiated for 8 h. The Raman spectrum of each sample was obtained before and after UV exposure. The compounds and the commercial formula containing IR-3535 showed photo-stability when irradiated, since no changes in the peaks were found. The commercial formula containing DEET showed spectral decrease at 524, 690, 1003 and 1606 cm-1, assigned to the DEET, and increase at 884 cm-1, assigned to the ethanol. These results indicate that the excipient could influence the photostability of the active ingredient. The Raman spectroscopy can be suitable to monitor the photodegradation under UV irradiation rapidly and reliably.

  11. Role of magnetic resonance venography in evaluation of cerebral ...

    African Journals Online (AJOL)

    Eman Abd-El Latif Abd-Elaziz El Damarawy

    2011-12-14

    Dec 14, 2011 ... Abbreviations: MRI, magnetic resonance imaging; MRV, magnetic resonance venography; SSS, superior sagittal sinus; CVO, cerebral venous occlusion; CVT, cerebral venous thrombosis; DSA, digital subtraction angiography; CT, computed tomography; CTV, computed tomography venography; CVST ...

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

    DEFF Research Database (Denmark)

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

    1992-01-01

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

  13. Effects of acupuncture therapy on abdominal fat and hepatic fat content in obese children: a magnetic resonance imaging and proton magnetic resonance spectroscopy study.

    Science.gov (United States)

    Zhang, Hong; Peng, Yun; Liu, ZuXiang; Li, Shilian; Lv, Zhongli; Tian, LiFang; Zhu, Jie; Zhao, XuNa; Chen, Min

    2011-05-01

    The aim of this study was to use magnetic resonance imaging (MRI) together with proton magnetic resonance spectroscopy ((1)H-MRS) to study the influence of acupuncture therapy on abdominal fat and hepatic fat content in obese children. The design was a longitudinal, clinical intervention study of acupuncture therapy. SUBJECTS were 10 healthy, obese children (age: 11.4 ± 1.65 years, body-mass index [BMI]: 29.03 ± 4.81 kg/m(2)). Measurements included various anthropometric parameters, abdominal fat (assessed by MRI) and hepatic fat content (assessed by (1)H-MRS) at baseline and after 1 month of acupuncture therapy. One (1) month of acupuncture therapy significantly reduced the subjects' BMI by 3.5% (p = 0.005), abdominal visceral adipose tissue (VAT) volume by 16.04% (p  0.05). There was a significant correlation between the level of abdominal fat (SAT, VAT) and anthropometric parameters (weight, BMI, waist circumferences, hip circumferences). There was no statistically significant correlation between IHTG and anthropometric parameters or abdominal fat content. The first direct experimental evidence is provided demonstrating that acupuncture therapy significantly reduces BMI and abdominal adipose tissue by reducing abdominal VAT content without significant changes in body weight, waist circumference, hip circumference, WHR, abdominal SAT, or IHTG content. Thus, the use of acupuncture therapy to selectively target a reduction in abdominal VAT content should become more important and more popular in the future.

  14. Resonances

    DEFF Research Database (Denmark)

    an impetus or drive to that account: change, innovation, rupture, or discontinuity. Resonances: Historical Essays on Continuity and Change explores the historiographical question of the modes of interrelation between these motifs in historical narratives. The essays in the collection attempt to realize...... theoretical consciousness through historical narrative ‘in practice’, by discussing selected historical topics from Western cultural history, within the disciplines of history, literature, visual arts, musicology, archaeology, philosophy, and theology. The title Resonances indicates the overall perspective...... of the book: how connotations of past meanings may resonate through time, in new contexts, assuming new meanings without surrendering the old....

  15. Cross-Polarized Surface-Enhanced Infrared Spectroscopy by Fano-Resonant Asymmetric Metamaterials.

    Science.gov (United States)

    Ishikawa, Atsushi; Hara, Shuhei; Tanaka, Takuo; Hayashi, Yasuhiko; Tsuruta, Kenji

    2017-06-09

    Plasmonic metamaterials have overcome fundamental limitations in conventional optics by their capability to engineer material resonances and dispersions at will, holding great promise for sensing applications. Recent demonstrations of metamaterial sensors, however, have mainly relied on their resonant nature for strong optical interactions with molecules, but few examples fully exploit their functionality to manipulate the polarization of light. Here, we present cross-polarized surface-enhanced infrared absorption (SEIRA) by the Fano-resonant asymmetric metamaterial allowing for strong background suppression as well as significant field enhancement. The metamaterial is designed to exhibit the controlled Fano resonance with the cross-polarization conversion property at 1730 cm-1, which spectrally overlaps with the C=O vibrational mode. In the cross-polarized SEIRA measurement, the C=O mode of poly(methyl methacrylate) molecules is clearly observed as a distinct dip within a Fano-resonant transmission peak of the metamaterial. The vibrational signal contrast is then improved based on the cross-polarized detection scheme where only the light interacting with the metamaterial-molecular coupled system is detected by totally eliminating the unwanted background light. Our metamaterial approach achieves the zeptomole sensitivity with a large signal-to-noise ratio in the far-field measurement, paving the way toward the realization of ultrasensitive IR inspection technologies.

  16. Magnetic resonance spectroscopy of current hand amputees reveals evidence for neuronal-level changes in former sensorimotor cortex.

    Science.gov (United States)

    Cirstea, Carmen M; Choi, In-Young; Lee, Phil; Peng, Huiling; Kaufman, Christina L; Frey, Scott H

    2017-04-01

    Deafferentation is accompanied by large-scale functional reorganization of maps in the primary sensory and motor areas of the hemisphere contralateral to injury. Animal models of deafferentation suggest a variety of cellular-level changes including depression of neuronal metabolism and even neuronal death. Whether similar neuronal changes contribute to patterns of reorganization within the contralateral sensorimotor cortex of chronic human amputees is uncertain. We used functional MRI-guided proton magnetic resonance spectroscopy to test the hypothesis that unilateral deafferentation is associated with lower levels of N -acetylaspartate (NAA, a putative marker of neuronal integrity) in the sensorimotor hand territory located contralateral to the missing hand in chronic amputees ( n = 19) compared with the analogous hand territory of age- and sex-matched healthy controls ( n = 28). We also tested whether former amputees [i.e., recipients of replanted ( n = 3) or transplanted ( n = 2) hands] exhibit NAA levels that are indistinguishable from controls, possible evidence for reversal of the effects of deafferentation. As predicted, relative to controls, current amputees exhibited lower levels of NAA that were negatively and significantly correlated with the time after amputation. Contrary to our prediction, NAA levels in both replanted and transplanted patients fell within the range of the current amputees. We suggest that lower levels of NAA in current amputees reflects altered neuronal integrity consequent to chronic deafferentation. Thus local changes in NAA levels may provide a means of assessing neuroplastic changes in deafferented cortex. Results from former amputees suggest that these changes may not be readily reversible through reafferentation. NEW & NOTEWORTHY This study is the first to use functional magnetic resonance-guided magnetic resonance spectroscopy to examine neurochemical mechanisms underlying functional reorganization in the primary somatosensory

  17. Evaluation of the fetal cerebellum by magnetic resonance imaging.

    Science.gov (United States)

    Llorens Salvador, R; Viegas Sainz, A; Montoya Filardi, A; Montoliu Fornas, G; Menor Serrano, F

    Obstetric protocols dictate that the fetal cerebellum should always be assessed during sonograms during pregnancy. For various reasons, including technical limitations or inconclusive sonographic findings, suspicion of cerebellar abnormalities is one of the most common indications for prenatal magnetic resonance imaging (MRI). Although sonography is the imaging technique of choice to assess the cerebellum, MRI shows the anatomy of the posterior fossa and abnormalities in the development of the fetal cerebellum in greater detail and thus enables a more accurate prenatal diagnosis. We describe and illustrate the normal anatomy of the fetal cerebellum on MRI as well as the different diseases that can affect its development. Moreover, we review the most appropriate terminology to define developmental abnormalities, their differential diagnoses, and the role of MRI in the prenatal evaluation of the posterior fossa. Copyright © 2017 SERAM. Publicado por Elsevier España, S.L.U. All rights reserved.

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

    DEFF Research Database (Denmark)

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

    1992-01-01

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

  19. Comparison of magnetic resonance imaging-compatible optical detectors for in-magnet tissue spectroscopy: photodiodes versus silicon photomultipliers.

    Science.gov (United States)

    El-Ghussein, Fadi; Jiang, Shudong; Pogue, Brian W; Paulsen, Keith D

    2014-01-01

    Tissue spectroscopy inside the magnetic resonance imaging (MRI) system adds a significant value by measuring fast vascular hemoglobin responses or completing spectroscopic identification of diagnostically relevant molecules. Advances in this type of spectroscopy instrumentation have largely focused on fiber coupling into and out of the MRI; however, nonmagnetic detectors can now be placed inside the scanner with signal amplification performed remotely to the high field environment for optimized light detection. In this study, the two possible detector options, such as silicon photodiodes (PD) and silicon photomultipliers (SiPM), were systematically examined for dynamic range and wavelength performance. Results show that PDs offer 10⁸(160 dB) dynamic range with sensitivity down to 1 pW, whereas SiPMs have 10⁷(140 dB) dynamic range and sensitivity down to 10 pW. A second major difference is the spectral sensitivity of the two detectors. Here, wavelengths in the 940 nm range are efficiently captured by PDs (but not SiPMs), likely making them the superior choice for broadband spectroscopy guided by MRI.

  20. Optical pathology of human brain metastasis of lung cancer using combined resonance Raman and spatial frequency spectroscopies

    Science.gov (United States)

    Zhou, Yan; Liu, Cheng-hui; Pu, Yang; Cheng, Gangge; Zhou, Lixin; Chen, Jun; Zhu, Ke; Alfano, Robert R.

    2016-03-01

    Raman spectroscopy has become widely used for diagnostic purpose of breast, lung and brain cancers. This report introduced a new approach based on spatial frequency spectra analysis of the underlying tissue structure at different stages of brain tumor. Combined spatial frequency spectroscopy (SFS), Resonance Raman (RR) spectroscopic method is used to discriminate human brain metastasis of lung cancer from normal tissues for the first time. A total number of thirty-one label-free micrographic images of normal and metastatic brain cancer tissues obtained from a confocal micro- Raman spectroscopic system synchronously with examined RR spectra of the corresponding samples were collected from the identical site of tissue. The difference of the randomness of tissue structures between the micrograph images of metastatic brain tumor tissues and normal tissues can be recognized by analyzing spatial frequency. By fitting the distribution of the spatial frequency spectra of human brain tissues as a Gaussian function, the standard deviation, σ, can be obtained, which was used to generate a criterion to differentiate human brain cancerous tissues from the normal ones using Support Vector Machine (SVM) classifier. This SFS-SVM analysis on micrograph images presents good results with sensitivity (85%), specificity (75%) in comparison with gold standard reports of pathology and immunology. The dual-modal advantages of SFS combined with RR spectroscopy method may open a new way in the neuropathology applications.