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Sample records for 31p-magnetic resonance spectroscopy

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

    NARCIS (Netherlands)

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

    2012-01-01

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

  2. 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

    consumption and 31P-magnetic resonance spectroscopy (31P-MRS). When perfused at rest with Krebs-Ringer buffer, the preparation maintained physiological levels of phosphocreatine (PCr), inorganic phosphate (Pi), ATP and pH at a stable oxygen consumption of 0.51 +/- 0.01 micromol min(-1) g(-1) for more than 2 h...

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

    Science.gov (United States)

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

    1987-10-24

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

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

    NARCIS (Netherlands)

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

    1991-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1990-11-01

    The hyperuricemia responsible for the development of gouty arthritis results from a wide range of environmental factors and underlying genetically determined aberrations of metabolism. {sup 31}P magnetic resonance spectroscopy studies of children with hereditary fructose intolerance revealed a readily detectable rise in phosphomonoesters with a marked fall in inorganic phosphate in their liver in vivo and a rise in serum urate in response to very low doses of oral fructose. Parents and some family members heterozygous for this enzyme deficiency showed a similar pattern when given a substantially larger dose of fructose. Three of the nine heterozygotes thus identified also had clinical gout, suggesting the possibility of this defect being a fairly common cause of gout. In the present study this same noninvasive technology was used to identify the same spectral pattern in 2 of the 11 families studied with hereditary gout. In one family, the index patient's three brothers and his mother all showed the fructose-induced abnormality of metabolism, in agreement with the maternal inheritance of metabolism, in agreement with the maternal inheritance of the gout in this family group. The test dose of fructose used produced a significantly larger increment in the concentration of serum urate in the patients showing the changes in {sup 31}P magnetic resonance spectra than in the other patients with familial gout or in nonaffected members, thus suggesting a simpler method for initial screening for the defect.

  6. 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...

  7. 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.

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

    Science.gov (United States)

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

    1994-08-01

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

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

    NARCIS (Netherlands)

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

    2011-01-01

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

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

    DEFF Research Database (Denmark)

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

    1992-01-01

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

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

    Science.gov (United States)

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

    2003-04-01

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

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

    Science.gov (United States)

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

    2011-05-01

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

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

    Institute of Scientific and Technical Information of China (English)

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

    2009-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1993-12-01

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

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

    Institute of Scientific and Technical Information of China (English)

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

    2001-01-01

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

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

    DEFF Research Database (Denmark)

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

    1990-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2010-02-15

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

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

    Energy Technology Data Exchange (ETDEWEB)

    Yoshiyama, Minoru

    1988-10-01

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

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

    Science.gov (United States)

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

    1994-10-01

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

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

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    Ming Li

    2016-07-01

    Full Text Available Background. Generally, males display greater strength and muscle capacity than females while performing a task. Muscle biopsy is regarded as the reference method of evaluating muscle functions; however, it is invasive and has sampling errors, and is not practical for longitudinal studies and dynamic measurement during excise. In this study, we built an in-house force control and gauge system for quantitatively applying force to quadriceps while the subjects underwent 31P Magnetic Resonance Spectroscopy (31P-MRS; our aim was to investigate if there is a sex difference of phosphate metabolite change in working muscles in young heathy Chinese volunteers. Methods. Volunteers performed knee-extending excises using a force control and gauge system while lying prone in a Philips 3T Magnetic Resonance (MR scanner. The 31P-MRS coil was firmly placed under the middle of the quadriceps . 31P-MRS measurements of inorganic phosphate (Pi, phosphocreatine (PCr and adenosine triphosphate (ATP were acquired from quadriceps while subjects were in a state of pre-, during- and post-exercise. The PCr, Pi, PCr/Pi, PCr/ATP, pH, work/energy cost ratio (WE, kPCr and oxidative capacity were compared between males and females. Results. A total of 17 volunteers underwent the study. Males: N = 10, age = 23.30 ± 1.25years; females: N = 7, age = 23.57 ± 0.79 years. In this study, males had significantly greater WE (16.33 ± 6.46 vs. 7.82 ± 2.16, p = 0.002 than females. Among PCr, Pi, PCr/Pi, PCr/ATP, pH, kPCr and oxidative capacity at different exercise status, only PCr/Pi (during-exercise, males = 5.630 ± 1.647, females = 4.014 ± 1.298, p = 0.047, PCr/ATP (during-exercise, males =1.273 ± 0.219, females = 1.523 ± 0.167, p = 0.025, and ATP (post-exercise, males = 24.469 ± 3.911 mmol/kg, females = 18.353 ± 4.818 mmol/kg, p = 0.035 had significant sex differences. Males had significantly greater PCr/Pi, but less PCr/ATP than females during exercise, suggesting males had

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

    Institute of Scientific and Technical Information of China (English)

    Wei Tan; Guangyao Wu; Junmo Sun

    2006-01-01

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

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

    Institute of Scientific and Technical Information of China (English)

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

    2014-01-01

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

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

    Institute of Scientific and Technical Information of China (English)

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

    2012-01-01

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

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

    Institute of Scientific and Technical Information of China (English)

    涂慧娟; 吴飞云; 秦斌; 陈婷; 齐静

    2012-01-01

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

  5. 31P-MRS评价肝细胞癌代谢水平及其与临床、病理特征的关系%Relationship between clinical-pathological features and metabolic status of hepatocellular carcinoma detected by 31p magnetic resonance spectroscopy

    Institute of Scientific and Technical Information of China (English)

    于德新; 马祥兴; 李笃民; 张晓明; 王茜; 李传福

    2011-01-01

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

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

    CERN Document Server

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

    2015-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2008-05-15

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

  8. Gluconeogenesis, liver energy metabolism and weight loss in lung cancer : dynamic studies using stable isotope tracers and 31P magnetic resonance spectroscopy

    NARCIS (Netherlands)

    S. Leij-Halfwerk (Susanne)

    1999-01-01

    textabstractWeight loss is a major problem in many types of cancer and is associated with reduced quality of life and a poor prognosis. Weight loss can also interfere with potentially curable treatment [41,561. Many uncertainties remain about the mechanisms underlying weight loss in patients with ca

  9. Effects of oral D-tagatose, a stereoisomer of D-fructose, on liver metabolism in man as examined by 31P-magnetic resonance spectroscopy

    DEFF Research Database (Denmark)

    Buemann, B; Gesmar, H; Astrup, A

    2000-01-01

    D-tagatose, which is a stereoisomer of D-fructose, is phosphorylated to D-tagatose-1-phosphate by fructokinase in the liver. Because of a slow degradation rate of D-tagatose-1-phosphate, this substance may accumulate, and ingested D-tagatose may therefore cause a longer lasting reduction in inorg...... concentration were found after D-fructose. These results suggest that a moderate intake of D-tagatose may affect liver metabolism by phosphate trapping despite the fact that the sugar may only be incompletely absorbed in the gut...

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

    Science.gov (United States)

    Tiret, Brice; Brouillet, Emmanuel; Valette, Julien

    2016-09-01

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

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

    DEFF Research Database (Denmark)

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

    1993-01-01

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

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

    DEFF Research Database (Denmark)

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

    1992-01-01

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

  13. Intracellular Phosphate Dynamics in Muscle Measured by Magnetic Resonance Spectroscopy during Hemodialysis.

    Science.gov (United States)

    Lemoine, Sandrine; Fournier, Thomas; Kocevar, Gabriel; Belloi, Amélie; Normand, Gabrielle; Ibarrola, Danielle; Sappey-Marinier, Dominique; Juillard, Laurent

    2016-07-01

    Of the 600-700 mg inorganic phosphate (Pi) removed during a 4-hour hemodialysis session, a maximum of 10% may be extracted from the extracellular space. The origin of the other 90% of removed phosphate is unknown. This study tested the hypothesis that the main source of phosphate removed during hemodialysis is the intracellular compartment. Six binephrectomized pigs each underwent one 3-hour hemodialysis session, during which the extracorporeal circulation blood flow was maintained between 100 and 150 ml/min. To determine in vivo phosphate metabolism, we performed phosphorous ((31)P) magnetic resonance spectroscopy using a 1.5-Tesla system and a surface coil placed over the gluteal muscle region. (31)P magnetic resonance spectra (repetition time =10 s; echo time =0.35 ms) were acquired every 160 seconds before, during, and after dialysis. During the dialysis sessions, plasma phosphate concentrations decreased rapidly (-30.4 %; P=0.003) and then, plateaued before increasing approximately 30 minutes before the end of the sessions; 16 mmol phosphate was removed in each session. When extracellular phosphate levels plateaued, intracellular Pi content increased significantly (11%; P<0.001). Moreover, βATP decreased significantly (P<0.001); however, calcium levels remained balanced. Results of this study show that intracellular Pi is the source of Pi removed during dialysis. The intracellular Pi increase may reflect cellular stress induced by hemodialysis and/or strong intracellular phosphate regulation.

  14. Growth inhibition in response to estrogen withdrawal and tamoxifen therapy of human breast cancer xenografts evaluated by in vivo 31P magnetic resonance spectroscopy, creatine kinase activity, and apoptotic index

    DEFF Research Database (Denmark)

    Kristensen, C A; Kristjansen, P E; Brünner, N;

    1995-01-01

    index, and creatine kinase (CK) activity. Tumors of each line were grown in ovariectomized nude mice during stimulation from a s.c. 17 beta-estradiol pellet. At a tumor size of approximately 350 mm3, the pellet was removed from one-half of the animals. The remaining one-half served as controls...

  15. Effect of estrogen withdrawal on energy-rich phosphates and prediction of estrogen dependence monitored by in vivo 31P magnetic resonance spectroscopy of four human breast cancer xenografts

    DEFF Research Database (Denmark)

    Kristensen, C A; Kristjansen, P E; Brünner, N

    1995-01-01

    The effect of estrogen withdrawal on energy metabolism was studied in four human breast cancer xenografts: the estrogen-dependent MCF-7 and ZR75-1 and the estrogen-independent ZR75/LCC-3 and MDA-MB-231. The tumors were grown in ovariectomized nude mice with a s.c. implanted estrogen pellet. After...

  16. 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)

  17. Nuclear Magnetic Resonance Spectroscopy

    Science.gov (United States)

    1992-04-23

    devices same is (C22-C24). A spectrometer based on adc SQUID that is ,I suitable for NQR and low-frequency NMR spectroscopy has is been developed (C25...relatively few papers that saE is have a primarily instrumental focus. This is due in part to s the tendency of spectrometer and probe vendors not to publish...from NOE data, etc. sNoe i This has been reflected in two trends in data processing SEN0S 12 hardware. Spectrometer vendors are starting to move awav 9

  18. Baryon Spectroscopy and Resonances

    Energy Technology Data Exchange (ETDEWEB)

    Robert Edwards

    2011-12-01

    A short review of current efforts to determine the highly excited state spectrum of QCD, and in particular baryons, using lattice QCD techniques is presented. The determination of the highly excited spectrum of QCD is a major theoretical and experimental challenge. The experimental investigation of the excited baryon spectrum has been a long-standing element of the hadronic-physics program, an important component of which is the search for so-called 'missing resonances', baryonic states predicted by the quark model based on three constituent quarks but which have not yet been observed experimentally. Should such states not be found, it may indicate that the baryon spectrum can be modeled with fewer effective degrees of freedom, such as in quark-diquark models. In the past decade, there has been an extensive program to collect data on electromagnetic production of one and two mesons at Jefferson Lab, MIT-Bates, LEGS, MAMI, ELSA, and GRAAL. To analyze these data, and thereby refine our knowledge of the baryon spectrum, a variety of physics analysis models have been developed at Bonn, George Washington University, Jefferson Laboratory and Mainz. To provide a theoretical determination and interpretation of the spectrum, ab initio computations within lattice QCD have been used. Historically, the calculation of the masses of the lowest-lying states, for both baryons and mesons, has been a benchmark calculation of this discretized, finite-volume computational approach, where the aim is well-understood control over the various systematic errors that enter into a calculation; for a recent review. However, there is now increasing effort aimed at calculating the excited states of the theory, with several groups presenting investigations of the low-lying excited baryon spectrum, using a variety of discretizations, numbers of quark flavors, interpolating operators, and fitting methodologies. Some aspects of these calculations remain unresolved and are the subject of

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

    DEFF Research Database (Denmark)

    Yamada, Shoko; Schmid, Silvan; Boisen, Anja

    2013-01-01

    Here, we report a demonstration of resonant photothermal IR spectroscopy using microstrings in mid-infrared region providing rapid identification of picogram samples. In our microelectromechanical resonant photothermal IR spectroscopy system, samples are deposited directly on microstrings using...... 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...

  20. Torque-mixing Magnetic Resonance Spectroscopy

    Science.gov (United States)

    Losby, Joseph; Fani Sani, Fatemeh; Grandmont, Dylan; Diao, Zhu; Belov, Miro; Burgess, Jacob; Compton, Shawn; Hiebert, Wayne; Vick, Doug; Mohammad, Kaveh; Salimi, Elham; Bridges, Gregory; Thomson, Douglas; Freeman, Mark

    A universal, mechanical torque method for magnetic resonance spectroscopy is presented. In analogy to resonance detection by induction, a signal proportional to the transverse component of a precessing dipole moment can be measured as a pure mechanical torque in broadband, frequency-swept spectroscopy. Comprehensive electron spin resonance of a single-crystal, mesoscopic yttrium iron garnet disk at room temperature are presented to demonstrate the method. The rich detail allows analysis of even complex 3D spin textures.

  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......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 transmission spectrum and it is very sensitive to the constituent materials as well as both lateral and vertical dimensions of the structures. This makes LSPR spectroscopy interesting for a number of applications including nanometrology. Like scatterometry, LSPR spectroscopy requires test structures...

  3. Proton Resonance Spectroscopy -- Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Shriner, Jr, J F

    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.

  4. Muscle metabolism from near infrared spectroscopy during rhythmic handgrip in humans

    DEFF Research Database (Denmark)

    Boushel, Robert Christopher; Pott, F; Madsen, P;

    1998-01-01

    with forearm oxygen uptake (VO2) [flow x (oxygen saturation in arnterial blood-oxygen saturation in venous blood, SaO2 - SvO2)], and with the 31P-magnetic resonance spectroscopy-determined ratio of inorganic phosphate to phosphocreatine (P(I):PCr). During ischaemia at rest, the fall in NIRS-O2 was more....... To conclude, NIRS-O2 of forearm flexor muscles closely reflected the exercise intensity and the metabolic rate determined by magnetic resonance spectroscopy but not that rate derived from flow and the arterio-venous oxygen difference....

  5. Progress in nuclear magnetic resonance spectroscopy

    CERN Document Server

    Emsley, J W; Sutcliffe, L H

    2013-01-01

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

  6. Frequency shifts in gravitational resonance spectroscopy

    CERN Document Server

    Baeßler, S; Pignol, G; Protasov, K V; Rebreyend, D; Kupriyanova, E A; Voronin, A Yu

    2015-01-01

    Quantum states of ultracold neutrons in the gravitational field are to be characterized through gravitational resonance spectroscopy. This paper discusses systematic effects that appear in the spectroscopic measurements. The discussed frequency shifts, which we call Stern-Gerlach shift, interference shift, and spectator state shift, appear in conceivable measurement schemes and have general importance. These shifts have to be taken into account in precision experiments.

  7. 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.

  8. 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)

  9. 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.

  10. 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.

  11. 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.

  12. 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.)

  13. 31P Magnetic resonance spectroscopyによるラット精巣機能の評価法の検討

    OpenAIRE

    鈴木, 裕志; 蟹本, 雄右; 岡田, 謙一郎; 石井, 靖

    1995-01-01

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

  14. 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.

  15. Spatial localization in nuclear magnetic resonance spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

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

    2006-08-21

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

  16. 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...

  17. Trace gas absorption spectroscopy using functionalized microring resonators.

    Science.gov (United States)

    Stievater, Todd H; Pruessner, Marcel W; Park, Doewon; Rabinovich, William S; McGill, R Andrew; Kozak, Dmitry A; Furstenberg, Robert; Holmstrom, Scott A; Khurgin, Jacob B

    2014-02-15

    We detect trace gases at parts-per-billion levels using evanescent-field absorption spectroscopy in silicon nitride microring resonators coated with a functionalized sorbent polymer. An analysis of the microring resonance line shapes enables a measurement of the differential absorption spectra for a number of vapor-phase analytes. The spectra are obtained at the near-infrared overtone of OH-stretch resonance, which provides information about the toxicity of the analyte vapor.

  18. Acoustic resonance spectroscopy for the advanced undergraduate laboratory

    CERN Document Server

    Franco-Villafañe, J A; Báez, G; Gandarilla-Carrillo, O; Méndez-Sánchez, R A

    2013-01-01

    We present a simple experiment that allows advanced undergraduates to learn the principles and applications of spectroscopy. The technique, known as acoustic resonance spectroscopy, is applied to study a vibrating rod. The setup includes electromagnetic-acoustic transducers, an audio amplifier and a vector network analyzer. Typical results of compressional, torsional and bending waves are analyzed and compared with analytical results.

  19. Acoustic resonance spectroscopy for the advanced undergraduate laboratory

    Science.gov (United States)

    Franco-Villafañe, J. A.; Flores-Olmedo, E.; Báez, G.; Gandarilla-Carrillo, O.; Méndez-Sánchez, R. A.

    2012-11-01

    We present a simple experiment that allows advanced undergraduates to learn the principles and applications of spectroscopy. The technique, known as acoustic resonance spectroscopy, is applied to study a vibrating rod. The setup includes electromagnetic-acoustic transducers, an audio amplifier and a vector network analyzer. Typical results of compressional, torsional and bending waves are analyzed and compared with analytical results.

  20. Chemical Principles Revisited. Proton Magnetic Resonance Spectroscopy.

    Science.gov (United States)

    McQuarrie, Donald A.

    1988-01-01

    Discusses how to interpret nuclear magnetic resonance (NMR) spectra and how to use them to determine molecular structures. This discussion is limited to spectra that are a result of observation of only the protons in a molecule. This type is called proton magnetic resonance (PMR) spectra. (CW)

  1. Torque-mixing magnetic resonance spectroscopy (Conference Presentation)

    Science.gov (United States)

    Losby, Joseph; Fani Sani, Fatemeh; Grandmont, Dylan T.; Diao, Zhu; Belov, Miro; Burgess, Jacob A.; Compton, Shawn R.; Hiebert, Wayne K.; Vick, Doug; Mohammad, Kaveh; Salimi, Elham; Bridges, Gregory E.; Thomson, Douglas J.; Freeman, Mark R.

    2016-10-01

    An optomechanical platform for magnetic resonance spectroscopy will be presented. The method relies on frequency mixing of orthogonal RF fields to yield a torque amplitude (arising from the transverse component of a precessing dipole moment, in analogy to magnetic resonance detection by electromagnetic induction) on a miniaturized resonant mechanical torsion sensor. In contrast to induction, the method is fully broadband and allows for simultaneous observation of the equilibrium net magnetic moment alongside the associated magnetization dynamics. To illustrate the method, comprehensive electron spin resonance spectra of a mesoscopic, single-crystal YIG disk at room temperature will be presented, along with situations where torque spectroscopy can offer complimentary information to existing magnetic resonance detection techniques. The authors are very grateful for support from NSERC, CRC, AITF, and NINT. Reference: Science 350, 798 (2015).

  2. Pulsed electron-nuclear-electron triple resonance spectroscopy

    Science.gov (United States)

    Thomann, Hans; Bernardo, Marcelino

    1990-05-01

    A new experimental technique, pulsed electron-nuclear-electron triple resonance spectroscopy, is demonstrated. It is based on a modification of the pulse sequence for electron-nuclear double resonance (ENDOR) in which two EPR and one NMR transition are irradiated. The irradiation of one EPR transition is detected via a second EPR transition. The nuclear hyperfine coupling, which separates these EPR transition frequencies, is the irradiated NMR transition. The major advantages of triple resonance spectroscopy include the ability to resolve overlapping nuclear resonances in the ENDOR spectrum and a more direct quantitative assignment of nuclear hyperfine and quadrupole couplings. The triple resonance experiment is an alternative to the recently proposed method of employing rapid magnetic field jumps between microwave pulses for generating hyperfine selective ENDOR spectra.

  3. Resonance scattering spectroscopy of gold nanoparticle

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The gold nanoparticles in diameter of 10-95 nm have been prepared by Frens procedure, all of which exhibit a resonance scattering peak at 580 nm. The mechanism of resonance scattering for gold nanoparticle has been considered according to the wave motion theory of nanoparticle in liquid. The principle of superamolecular interface energy band(SIEB) has been set up and utilized to explain the relationship between the diameter and colors for gold nanoparticle in liquid. A novel spectrophotometric ruler for the determination of the diameter has been proposed according to the relationship of the maximum absorption wavelength and diameter.

  4. 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......Micromechanical photothermal infrared spectroscopy is a promising technique, where absorption-related heating is detected by frequency detuning of microstring resonators. We present photothermal infrared spectroscopy with mechanical string resonators providing rapid identification of femtogram......-scale airborne samples. Airborne sample material is directly collected on the microstring with an efficient nondiffusion limited sampling method based on inertial impaction. Resonance frequency shifts, proportional to the absorbed heat in the microstring, are recorded as monochromatic IR light is scanned over...

  5. 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....

  6. 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....

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

    Institute of Scientific and Technical Information of China (English)

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

    2000-01-01

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

  8. Active plasma resonance spectroscopy: A functional analytic description

    OpenAIRE

    Lapke, Martin; Oberrath, Jens; Mussenbrock, Thomas; Brinkmann, Ralf Peter

    2012-01-01

    The term "Active Plasma Resonance Spectroscopy" refers to a class of diagnostic methods which employ the ability of plasmas to resonate on or near the plasma frequency. The basic idea dates back to the early days of discharge physics: An signal in the GHz range is coupled to the plasma via an electrical probe; the spectral response is recorded, and then evaluated with a mathematical model to obtain information on the electron density and other plasma parameters. In recent years, the concept h...

  9. 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.

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

    Science.gov (United States)

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

    2006-01-01

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

  11. 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…

  12. 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.

  13. Diamond based single molecule magnetic resonance spectroscopy

    CERN Document Server

    Cai, J -M; Plenio, M B; Retzker, A

    2011-01-01

    The detection of a nuclear spin in an individual molecule represents a key challenge in physics and biology whose solution has been pursued for many years. The small magnetic moment of a single nucleus and the unavoidable environmental noise present the key obstacles for its realization. Here, we theoretically demonstrate that a single nitrogen-vacancy (NV) center in diamond can be used to construct a nano-scale single molecule spectrometer that is capable of detecting the position and spin state of a single nucleus and can determine the distance and alignment of a nuclear or electron spin pair. In combination with organic spin labels, this device will find applications in single molecule spectroscopy in chemistry and biology, such as in determining protein structure or monitoring macromolecular motions and can thus provide a tool to help unravelling the microscopic mechanisms underlying bio-molecular function.

  14. Magnetic resonance spectroscopy may hold promise in studying metabolites, tissues

    Energy Technology Data Exchange (ETDEWEB)

    1989-02-24

    Almost 15 years ago, in a basement at Chicago's University of Illinois Medical Center, Michael Barany, MD, PhD, measured phosphorus metabolites in an intact frog muscle using magnetic resonance spectroscopy (MRS). Prior to that, chemists used spectroscopy solely to analyze the contents of test tubes. Only a British group preceded Barany in proving that it would work in tissue as well. Today, he does spectroscopy clinically, one day a week, at the Greenberg Radiology Institute in Highland Park, IL, north of Chicago. Barany says that he can distinguish malignant from benign tumors in the living brain. The tool he uses is a standard magnetic resonance imaging (MRI) machine. While MRI capabilities have forged ahead, human MRS has been awaiting improvements in magnet and computer technology. Barany is one of a number of researchers who, since the early 1980s, have been developing MRS technology and techniques so that it can be done in the human body.

  15. 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

  16. 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...

  17. Wax Point Determinations Using Acoustic Resonance Spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Bostick, D.T.; Jubin, R.T.; Schmidt, T.W.

    2001-06-01

    The thermodynamic characterization of the wax point of a given crude is essential in order to maintain flow conditions that prevent plugging of undersea pipelines. This report summarizes the efforts made towards applying an Acoustic Cavity Resonance Spectrometer (ACRS) to the determination of pressures and temperatures at which wax precipitates from crude. Phillips Petroleum Company, Inc., the CRADA participant, supplied the ACRS. The instrumentation was shipped to Dr. Thomas Schmidt of ORNL, the CRADA contractor, in May 2000 after preliminary software development performed under the guidance of Dr. Samuel Colgate and Dr. Evan House of the University of Florida, Gainesville, Fl. Upon receipt it became apparent that a number of modifications still needed to be made before the ACRS could be precisely and safely used for wax point measurements. This report reviews the sequence of alterations made to the ACRS, as well as defines the possible applications of the instrumentation once the modifications have been completed. The purpose of this Cooperative Research and Development Agreement (CRADA) between Phillips Petroleum Company, Inc. (Participant) and Lockheed Martin Energy Research Corporation (Contractor) was the measurement of the formation of solids in crude oils and petroleum products that are commonly transported through pipelines. This information is essential in the proper design, operation and maintenance of the petroleum pipeline system in the United States. Recently, new petroleum discoveries in the Gulf of Mexico have shown that there is a potential for plugging of undersea pipeline because of the precipitation of wax. It is important that the wax points of the expected crude oils be well characterized so that the production facilities for these new wells are capable of properly transporting the expected production. The goal of this work is to perform measurements of solids formation in crude oils and petroleum products supplied by the Participant. It is

  18. 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 1H MRS of cells and 1H magnetic resonance spectroscopic imaging (MRSI) of tumors to assess the efficacy of the downregulation. PMID:26530913

  19. Gravity Resonance Spectroscopy and Einstein-Cartan Gravity

    CERN Document Server

    Abele, Hartmut; 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.

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

    OpenAIRE

    Hossein Pourmodheji; Ebrahim Ghafar-Zadeh; Sebastian Magierowski

    2016-01-01

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

  1. 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.

  2. Scanning micro-resonator direct-comb absolute spectroscopy

    CERN Document Server

    Gambetta, Alessio; Gatti, Davide; Laporta, Paolo; Galzerano, Gianluca

    2016-01-01

    Direct optical frequency Comb Spectroscopy (DCS) is proving to be a fundamental tool in many areas of science and technology thanks to its unique performance in terms of ultra-broadband, high-speed detection and frequency accuracy, allowing for high-fidelity mapping of atomic and molecular energy structure. Here we present a novel DCS approach based on a scanning Fabry-Perot micro-cavity resonator (SMART) providing a simple, compact and accurate method to resolve the mode structure of an optical frequency comb. The SMART approach, while drastically reducing system complexity, allows for a straightforward absolute calibration of the optical-frequency axis with an ultimate resolution limited by the micro-resonator resonance linewidth and can be used in any spectral region from XUV to THz. An application to high-precision spectroscopy of acetylene at 1.54 um is presented, demonstrating frequency resolution as low as 20 MHz with a single-scan optical bandwidth up to 1 THz in 20-ms measurement time and a noise-equ...

  3. 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

  4. 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.

  5. Molecular aspects of magnetic resonance imaging and spectroscopy.

    Science.gov (United States)

    Boesch, C

    1999-01-01

    Magnetic resonance imaging (MRI) is a well known diagnostic tool in radiology that produces unsurpassed images of the human body, in particular of soft tissue. However, the medical community is often not aware that MRI is an important yet limited segment of magnetic resonance (MR) or nuclear magnetic resonance (NMR) as this method is called in basic science. The tremendous morphological information of MR images sometimes conceal the fact that MR signals in general contain much more information, especially on processes on the molecular level. NMR is successfully used in physics, chemistry, and biology to explore and characterize chemical reactions, molecular conformations, biochemical pathways, solid state material, and many other applications that elucidate invisible characteristics of matter and tissue. In medical applications, knowledge of the molecular background of MRI and in particular MR spectroscopy (MRS) is an inevitable basis to understand molecular phenomenon leading to macroscopic effects visible in diagnostic images or spectra. This review shall provide the necessary background to comprehend molecular aspects of magnetic resonance applications in medicine. An introduction into the physical basics aims at an understanding of some of the molecular mechanisms without extended mathematical treatment. The MR typical terminology is explained such that reading of original MR publications could be facilitated for non-MR experts. Applications in MRI and MRS are intended to illustrate the consequences of molecular effects on images and spectra.

  6. Nuclear magnetic resonance spectroscopy of single subnanoliter ova

    CERN Document Server

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

    2015-01-01

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

  7. Elastic properties of gamma-Pu by resonant ultrasound spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Migliori, Albert [Los Alamos National Laboratory; Betts, J [Los Alamos National Laboratory; Trugman, A [Los Alamos National Laboratory; Mielke, C H [Los Alamos National Laboratory; Mitchell, J N [Los Alamos National Laboratory; Ramos, M [Los Alamos National Laboratory; Stroe, I [WORXESTER, MA

    2009-01-01

    Despite intense experimental and theoretical work on Pu, there is still little understanding of the strange properties of this metal. We used resonant ultrasound spectroscopy method to investigate the elastic properties of pure polycrystalline Pu at high temperatures. Shear and longitudinal elastic moduli of the {gamma}-phase of Pu were determined simultaneously and the bulk modulus was computed from them. A smooth linear and large decrease of all elastic moduli with increasing temperature was observed. We calculated the Poisson ratio and found that it increases from 0.242 at 519K to 0.252 at 571K.

  8. 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).

  9. Sub-terahertz resonance spectroscopy of biological macromolecules and cells

    Science.gov (United States)

    Globus, Tatiana; Moyer, Aaron; Gelmont, Boris; Khromova, Tatyana; Sizov, Igor; Ferrance, Jerome

    2013-05-01

    Recently we introduced a Sub-THz spectroscopic system for characterizing vibrational resonance features from biological materials. This new, continuous-wave, frequency-domain spectroscopic sensor operates at room temperature between 315 and 480 GHz with spectral resolution of at least 1 GHz and utilizes the source and detector components from Virginia Diode, Inc. In this work we present experimental results and interpretation of spectroscopic signatures from bacterial cells and their biological macromolecule structural components. Transmission and absorption spectra of the bacterial protein thioredoxin, DNA and lyophilized cells of Escherichia coli (E. coli), as well as spores of Bacillus subtillis and B. atrophaeus have been characterized. Experimental results for biomolecules are compared with absorption spectra calculated using molecular dynamics simulation, and confirm the underlying physics for resonance spectroscopy based on interactions between THz radiation and vibrational modes or groups of modes of atomic motions. Such interactions result in multiple intense and narrow specific resonances in transmission/absorption spectra from nano-gram samples with spectral line widths as small as 3 GHz. The results of this study indicate diverse relaxation dynamic mechanisms relevant to sub-THz vibrational spectroscopy, including long-lasting processes. We demonstrate that high sensitivity in resolved specific absorption fingerprints provides conditions for reliable detection, identification and discrimination capability, to the level of strains of the same bacteria, and for monitoring interactions between biomaterials and reagents in near real-time. Additionally, it creates the basis for the development of new types of advanced biological sensors through integrating the developed system with a microfluidic platform for biomaterial samples.

  10. Thin liquid sample fabrication for neutron resonance spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Noguere, G. [CEA Cadarache, F-13108 Saint Paul les Durance (France)], E-mail: gilles.noguere@cea.fr; Brusegan, A. [EC-JRC-IRMM, B-2440 Geel (Belgium); Lepretre, A. [CEA Saclay, F-91191 Gif sur Yvette (France); Lombard, T.; Lupo, J. [EC-JRC-IRMM, B-2440 Geel (Belgium)

    2008-03-11

    In neutron resonance spectroscopy, preparation of thin cylindrical samples of large diameter containing 10{sup -4}-10{sup -5} atoms per barn of raw materials in powder form make pressing a uniform thickness sample difficult. The use of liquid samples is a suitable alternative to overcome the technical limits inherent to the fabrication of pressed solid samples by compaction methods. This paper presents the fabrication of a 2 mm thick cylindrical sample, with a inner diameter of 65 mm, filled with an aqueous solution of lithium iodide. The sample was designed to measure the low neutron energy range of the {sup 127}I total cross-section by means of the neutron resonance transmission technique. The resonance shape analysis provided results consistent with those obtained by measuring a 17.5 mm thick lead iodine sample under the same experimental conditions as for LiI sample. Such liquid sample could be used to repeat similar measurements on a large variety of stable isotopes and low radioactive materials.

  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. Simultaneous surface plasmon resonance and x-ray absorption spectroscopy

    Science.gov (United States)

    Serrano, A.; Rodríguez de la Fuente, O.; Collado, V.; Rubio-Zuazo, J.; Monton, C.; Castro, G. R.; García, M. A.

    2012-08-01

    We present an experimental setup for the simultaneous measurement of surface plasmon resonance (SPR) and x-ray absorption spectroscopy (XAS) on metallic thin films at a synchrotron beamline. The system allows measuring in situ and in real time the effect of x-ray irradiation on the SPR curves to explore the interaction of x-rays with matter. It is also possible to record XAS spectra while exciting SPR in order to study changes in the films induced by the excitation of surface plasmons. Combined experiments recording simultaneously SPR and XAS curves while scanning different parameters can be also carried out. The relative variations in the SPR and XAS spectra that can be detected with this setup range from 10-3 to 10-5, depending on the particular experiment.

  13. Brain proton magnetic resonance spectroscopy for hepatic encephalopathy

    Science.gov (United States)

    Ong, Chin-Sing; McConnell, James R.; Chu, Wei-Kom

    1993-08-01

    Liver failure can induce gradations of encephalopathy from mild to stupor to deep coma. The objective of this study is to investigate and quantify the variation of biochemical compounds in the brain in patients with liver failure and encephalopathy, through the use of water- suppressed, localized in-vivo Proton Magnetic Resonance Spectroscopy (HMRS). The spectral parameters of the compounds quantitated are: N-Acetyl Aspartate (NAA) to Creatine (Cr) ratio, Choline (Cho) to Creatine ratio, Inositol (Ins) to Creatine ratio and Glutamine-Glutamate Amino Acid (AA) to Creatine ratio. The study group consisted of twelve patients with proven advanced chronic liver failure and symptoms of encephalopathy. Comparison has been done with results obtained from five normal subjects without any evidence of encephalopathy or liver diseases.

  14. Electron energy-loss spectroscopy of branched gap plasmon resonators

    Science.gov (United States)

    Raza, Søren; Esfandyarpour, Majid; Koh, Ai Leen; Mortensen, N. Asger; Brongersma, Mark L.; Bozhevolnyi, Sergey I.

    2016-12-01

    The miniaturization of integrated optical circuits below the diffraction limit for high-speed manipulation of information is one of the cornerstones in plasmonics research. By coupling to surface plasmons supported on nanostructured metallic surfaces, light can be confined to the nanoscale, enabling the potential interface to electronic circuits. In particular, gap surface plasmons propagating in an air gap sandwiched between metal layers have shown extraordinary mode confinement with significant propagation length. In this work, we unveil the optical properties of gap surface plasmons in silver nanoslot structures with widths of only 25 nm. We fabricate linear, branched and cross-shaped nanoslot waveguide components, which all support resonances due to interference of counter-propagating gap plasmons. By exploiting the superior spatial resolution of a scanning transmission electron microscope combined with electron energy-loss spectroscopy, we experimentally show the propagation, bending and splitting of slot gap plasmons.

  15. Simultaneous Surface Plasmon Resonance and X-ray Absorption Spectroscopy

    CERN Document Server

    Serrano, A; Collado, V; Rubio-Zuazo, J; Monton, C; Castro, G; García, M A

    2012-01-01

    We present here an experimental set-up to perform simultaneously measurements of surface plasmon resonance (SPR) and X-ray absorption spectroscopy (XAS) in a synchrotron beamline. The system allows measuring in situ and in real time the effect of X-ray irradiation on the SPR curves to explore the interaction of X-rays with matter. It is also possible to record XAS spectra while exciting SPR in order to detect the changes in the electronic configuration of thin films induced by the excitation of surface plasmons. Combined experiments recording simultaneously SPR and XAS curves while scanning different parameters can be carried out. The relative variations in the SPR and XAS spectra that can be detected with this set-up ranges from 10-3 to 10-5, depending on the particular experiment.

  16. Simultaneous surface plasmon resonance and x-ray absorption spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Serrano, A. [Instituto de Ceramica y Vidrio (ICV-CSIC), Cantoblanco, 28049 Madrid (Spain); Departamento de Fisica de Materiales, Universidad Complutense de Madrid, 28040 Madrid (Spain); Rodriguez de la Fuente, O. [Departamento de Fisica de Materiales, Universidad Complutense de Madrid, 28040 Madrid (Spain); Collado, V.; Rubio-Zuazo, J.; Castro, G. R. [SpLine, Spanish CRG Beamline at the ESRF, F-38043 Grenoble, Cedex 09, France and Instituto de Ciencia de Materiales de Madrid, (ICMM-CSIC), Cantoblanco, 28049 Madrid (Spain); Monton, C. [Department of Physics and Center for Advanced Nanoscience, University of California San Diego, La Jolla, California 92093 (United States); Garcia, M. A. [Instituto de Ceramica y Vidrio (ICV-CSIC), Cantoblanco, 28049 Madrid (Spain); IMDEA Nanociencia, Cantoblanco, 28049 Madrid (Spain)

    2012-08-15

    We present an experimental setup for the simultaneous measurement of surface plasmon resonance (SPR) and x-ray absorption spectroscopy (XAS) on metallic thin films at a synchrotron beamline. The system allows measuring in situ and in real time the effect of x-ray irradiation on the SPR curves to explore the interaction of x-rays with matter. It is also possible to record XAS spectra while exciting SPR in order to study changes in the films induced by the excitation of surface plasmons. Combined experiments recording simultaneously SPR and XAS curves while scanning different parameters can be also carried out. The relative variations in the SPR and XAS spectra that can be detected with this setup range from 10{sup -3} to 10{sup -5}, depending on the particular experiment.

  17. 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.

  18. Resonant and Time-Resolved Spin Noise Spectroscopy

    Science.gov (United States)

    Song, Xinlin; Pursley, Brennan; Sih, Vanessa

    Spin noise spectroscopy is a technique which can probe the system while it remains in equilibrium. It was first demonstrated in atomic gases and then in solid state systems. Most existing spin noise measurement setups digitize the spin fluctuation signal and then analyze the power spectrum. Recently, pulsed lasers have been used to expand the bandwidth of accessible dynamics and allow direct time-domain correlation measurements. Here we develop and test a model for ultrafast pulsed laser spin noise measurements as well as a scheme to measure spin lifetimes longer than the laser repetition period. For the resonant spin noise technique, analog electronics are used to capture correlations from the extended pulse train, and the signal at a fixed time delay is measured as a function of applied magnetic field.

  19. Active plasma resonance spectroscopy: A functional analytic description

    CERN Document Server

    Lapke, Martin; Mussenbrock, Thomas; Brinkmann, Ralf Peter

    2012-01-01

    The term "Active Plasma Resonance Spectroscopy" refers to a class of diagnostic methods which employ the ability of plasmas to resonate on or near the plasma frequency. The basic idea dates back to the early days of discharge physics: An signal in the GHz range is coupled to the plasma via an electrical probe; the spectral response is recorded, and then evaluated with a mathematical model to obtain information on the electron density and other plasma parameters. In recent years, the concept has found renewed interest as a basis of industry compatible plasma diagnostics. This paper analyzes the diagnostics technique in terms of a general description based on functional analytic (or Hilbert Space) methods which hold for arbitrary probe geometries. It is shown that the response function of the plasma-probe system can be expressed as a matrix element of the resolvent of an appropriately defined dynamical operator. A specialization of the formalism for a symmetric probe desing is given, as well as an interpreation...

  20. 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.

  1. Two-dimensional Nutation Echo Nuclear Quadrupole Resonance Spectroscopy

    Science.gov (United States)

    Harbison, Gerard S.; Slokenbergs, Andris

    1990-04-01

    We discuss two new two-dimensional nuclear quadrupole resonance experiments, both based on the principle of nutation spectroscopy, which can be used to determine the asymmetry parameter, and thus the full quadrupolar tensor, of spin-3/2 nuclei at zero applied magnetic field. The first experiment is a simple nutation pulse sequence in which the first time period (t1) is the duration of the radiofrequency exciting pulse; and the second (t2) is the normal free-precession of a quadrupolar nucleus at zero-field. After double Fourier-transformation, the result is a 2 D spectrum in which the first frequency dimension is the nutation spectrum for the quadrupolar nucleus at zero-field. For polycrystalline samples this sequence generates powder lineshapes; the position of the singularities, in these lineshapes can be used to determine the asymmetry parameters η in a very straightforward manner, η has previously only been obtainable using Zeeman perturbed NQR methods. The second sequence is the same nutation experiment with a spin-echo pulse added. The virtue of this refocussing pulse is that it allows acquisition of nutation spectra from samples with arbitrary inhomogeneous linewidth; thus, asymmetry parameters can be determined even where the quadrupolar resonance is wider than the bandwidth of the spectrometer. Experimental examples of 35Cl, 81Br and 63Cu nutation and nutation-echo spectra are presented.

  2. In vivo magnetic resonance spectroscopy of liver tumors and metastases

    Institute of Scientific and Technical Information of China (English)

    EGW ter Voert; L Heijmen; HWM van Laarhoven; A Heerschap

    2011-01-01

    Primary liver cancer is the fifth most common malignancy in men and the eighth in women worldwide. The liver is also the second most common site for metastatic spread of cancer. To assist in the diagnosis of these liver lesions non-invasive advanced imaging techniques are desirable. Magnetic resonance (MR) is commonly used to identify anatomical lesions, but it is a very versatile technique and also can provide specific information on tumor pathophysiology and metabolism,in particular with the application of MR spectroscopy (MRS). This may include data on the type, grade and stage of tumors, and thus assist in further management of the disease. The purpose of this review is to summarize and discuss the available literature on proton, phosphorus and carbon-13-MRS as performed on primary liver tumors and metastases, with human applications as the main perspective. Upcoming MRS approaches with potential applications to liver tumors are also included. Since knowledge of some technical background is indispensable to understand the results, a basic introduction of MRS and some technical issues of MRS as applied to tumors and metastases in the liver are described as well. In vivo MR spectroscopy of tumors in a metabolically active organ such as the liver has been demonstrated to provide important information on tumor metabolism, but it also is challenging as compared to applications on some other tissues, in particular in humans, mostly because of its abdominal location where movement may be a disturbing factor.

  3. Collinear resonant ionization laser spectroscopy of rare francium isotopes

    CERN Multimedia

    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...

  4. 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

  5. Magnetic resonance spectroscopy imaging characteristics of cerebral Blastomycosis

    Directory of Open Access Journals (Sweden)

    Jay A Vachhani

    2014-01-01

    Full Text Available Background: Blastomycosis is a dimorphic fungus that is endemic to the midwest and southwestern United States. Involvement of the central nervous system (CNS is thought to only represent 5-10% of cases of disseminated Blastomycosis. Case Description: A 54-year-old Caucasian female presented to the Neurosurgery service with a 1-day history of progressive right sided hemiparesis. Magnetic resonance imaging (MRI demonstrated a 2 × 4 cm heterogeneous intracranial mass lesion involving the left motor cortex and extending into the ipsilateral parietal lobe. Single-voxel magnetic resonance spectroscopy (MRS over the enhancing area demonstrated diminished N-acetyl aspartate (NAA to creatine ratio (1.10, normal choline to NAA ratio (0.82, normal choline to creatine ratio (0.9, and a diminished myoinositol to creatine ratio (0.39. There appeared to be peaks between 3.6 and 3.8 ppm over the enhancing area that were not present in the contralateral normal brain and thought to represent a "trehalose" peak. Due to worsening symptoms and uncertain preoperative diagnosis, the patient underwent a left fronto-parietal craniotomy for open surgical biopsy with possible resection approximately one month after presentation. Pathological analysis confirmed the diagnosis of Blastomycosis. Conclusion: We present the second documented case of intracranial Blastomycosis with MRS imaging. There appears to be a characteristic peak between 3.6 and 3.8 ppm that is thought to represent a "trehalose" peak. This peak is rather specific to fungi and can be helpful in differentiating fungal abscesses from pyogenic abscesses and malignant neoplasms.

  6. Tetrachloridocuprates(II—Synthesis and Electron Paramagnetic Resonance (EPR Spectroscopy

    Directory of Open Access Journals (Sweden)

    Peter Strauch

    2012-02-01

    Full Text Available Ionic liquids (ILs on the basis of metal containing anions and/or cations are of interest for a variety of technical applications e.g., synthesis of particles, magnetic or thermochromic materials. We present the synthesis and the results of electron paramagnetic resonance (EPR spectroscopic analyses of a series of some new potential ionic liquids based on tetrachloridocuprates(II, [CuCl4]2−, with different sterically demanding cations: hexadecyltrimethylammonium 1, tetradecyltrimethylammonium 2, tetrabutylammonium 3 and benzyltriethylammonium 4. The cations in the new compounds were used to achieve a reasonable separation of the paramagnetic Cu(II ions for EPR spectroscopy. The EPR hyperfine structure was not resolved. This is due to the exchange broadening, resulting from still incomplete separation of the paramagnetic Cu(II centers. Nevertheless, the principal values of the electron Zeemann tensor (g║ and g┴ of the complexes could be determined. Even though the solid substances show slightly different colors, the UV/Vis spectra are nearly identical, indicating structural changes of the tetrachloridocuprate moieties between solid state and solution. The complexes have a promising potential e.g., as high temperature ionic liquids, as precursors for the formation of copper chloride particles or as catalytic paramagnetic ionic liquids.

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

    Science.gov (United States)

    Bai, Yanjie; Shi, Yong-Cheng

    2016-10-20

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

  8. 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).

  9. Strong overtones and combination bands in ultraviolet resonance Raman spectroscopy.

    Science.gov (United States)

    Efremov, Evtim V; Ariese, Freek; Mank, Arjan J G; Gooijer, Cees

    2006-05-01

    Ultraviolet resonance Raman spectroscopy is carried out using a continuous wave frequency-doubled argon ion laser operated at 229, 244, and 257 nm in order to characterize the overtones and combination bands for several classes of organic compounds in liquid solutions. Contrary to what is generally anticipated, for molecules such as pyrene and anthracene, strong overtones and combination bands can show up; it is demonstrated that their intensity depends critically on the applied laser wavelength. If the excitation wavelength corresponds with a purely electronic transition--this applies to a good approximation for 244-nm excitation in the case of pyrene and for 257-nm excitation in the case of anthracene--mostly fundamental vibrations (up to 1700 cm(-1)) are observed. Overtones and combination bands are detected but are rather weak. However, if the laser overlaps with the vibronic region--as holds for 229- and 257-nm excitation for pyrene and 244-nm excitation for anthracene--very strong bands are found in the region 1700-3400 cm(-1). As illustrated for pyrene at 257 nm, all these bands can be assigned to first overtones or binary combinations of fundamental vibrations. Their intensity distribution can roughly be simulated by multiplying the relative intensities of the fundamental bands. Significant bands can also be found in the region 3400-5000 cm(-1), corresponding with second overtones and ternary combinations. It is shown that these findings are not restricted to planar and rigid molecules with high symmetry. Substituted pyrenes exhibit similar effects, and relatively strong overtones are also observed for adenosine monophosphate and for abietic acid. The reasons for these observations are discussed, as well as the potential applicability for analytical purposes.

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

    Science.gov (United States)

    Friedrich, Jan O.

    1988-12-01

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

  11. 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.

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

    Directory of Open Access Journals (Sweden)

    Hossein Pourmodheji

    2016-06-01

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

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

    Science.gov (United States)

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

    2016-06-09

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

  14. Brain proton magnetic resonance spectroscopy of alcohol use disorders.

    Science.gov (United States)

    Meyerhoff, Dieter J

    2014-01-01

    This chapter critically reviews brain proton magnetic resonance spectroscopy ((1)H MRS) studies performed since 1994 in individuals with alcohol use disorders (AUD). We describe the neurochemicals that can be measured in vivo at the most common magnetic field strengths, summarize our knowledge about their general brain functions, and briefly explain some basic human (1)H MRS methods. Both cross-sectional and longitudinal research of individuals in treatment and of treatment-naïve individuals with AUD are discussed and interpreted on the basis of reported neuropathology. As AUDs are highly comorbid with chronic cigarette smoking and illicit substance abuse, we also summarize reports on their respective influences on regional proton metabolite levels. After reviewing research on neurobiologic correlates of relapse and genetic influences on brain metabolite levels, we finish with suggestions on future directions for (1)H MRS studies in AUDs. The review demonstrates that brain metabolic alterations associated with AUDs as well as their cognitive correlates are not simply a consequence of chronic alcohol consumption. Future MR research of AUDs in general has to be better prepared - and supported - to study clinically complex relationships between personality characteristics, comorbidities, neurogenetics, lifestyle, and living environment, as all these factors critically affect an individual's neurometabolic profile. (1)H MRS is uniquely positioned to tackle these complexities by contributing to a comprehensive biopsychosocial profile of individuals with AUD: it can provide non-invasive biochemical information on select regions of the brain at comparatively low overall cost for the ultimate purpose of informing more efficient treatments of AUDs.

  15. Proton magnetic resonance spectroscopy in 22q11 deletion syndrome.

    Directory of Open Access Journals (Sweden)

    Fabiana da Silva Alves

    Full Text Available OBJECTIVE: People with velo-cardio-facial syndrome or 22q11 deletion syndrome (22q11DS have behavioral, cognitive and psychiatric problems. Approximately 30% of affected individuals develop schizophrenia-like psychosis. Glutamate dysfunction is thought to play a crucial role in schizophrenia. However, it is unknown if and how the glutamate system is altered in 22q11DS. People with 22q11DS are vulnerable for haploinsufficiency of PRODH, a gene that codes for an enzyme converting proline into glutamate. Therefore, it can be hypothesized that glutamatergic abnormalities may be present in 22q11DS. METHOD: We employed proton magnetic resonance spectroscopy ((1H-MRS to quantify glutamate and other neurometabolites in the dorsolateral prefrontal cortex (DLPFC and hippocampus of 22 adults with 22q11DS (22q11DS SCZ+ and without (22q11DS SCZ- schizophrenia and 23 age-matched healthy controls. Also, plasma proline levels were determined in the 22q11DS group. RESULTS: We found significantly increased concentrations of glutamate and myo-inositol in the hippocampal region of 22q11DS SCZ+ compared to 22q11DS SCZ-. There were no significant differences in levels of plasma proline between 22q11DS SCZ+ and 22q11DS SCZ-. There was no relationship between plasma proline and cerebral glutamate in 22q11DS. CONCLUSION: This is the first in vivo(1H-MRS study in 22q11DS. Our results suggest vulnerability of the hippocampus in the psychopathology of 22q11DS SCZ+. Altered hippocampal glutamate and myo-inositol metabolism may partially explain the psychotic symptoms and cognitive impairments seen in this group of patients.

  16. 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

  17. Dysembryoplastic neuroepithelial tumors: magnetic resonance imaging and magnetic resonance spectroscopy evaluation

    Institute of Scientific and Technical Information of China (English)

    YU Ai-hong; CHEN Li; LI Yong-jie; ZHANG Guo-jun; LI Kun-cheng; WANG Yu-ping

    2009-01-01

    Background Dysembryoplastic neuroepithelial tumor (DNT) is a rare benign neoplasm of the central nervous system affecting young people. A correct preoperative diagnosis is helpful for planning surgical strategies and improving prognosis. The purpose of this study was to characterize DNTs using magnetic resonance imaging (MRI) and magnetic resonance spectroscopy (MRS) and to analyze the value of these two techniques in the diagnosis of DNTs.Methods MR images of 13 patients with DNTs were reviewed retrospectively; and five of the patients also underwent MRS. Tumors were confirmed by surgery. The distribution, extension and signal features of the lesions were assessed,and the MRS results were analyzed.Results All tumors were supratentorial. The cortex was the main area involved, with nine tumors located in the temporal lobe, three in the frontal lobe, and one on the boundary between the temporal and occipital lobes. All cases had decreased signal intensity on T1-weighted MR images and increased signal intensity on T2-weighted images. On fluid attenuated inversion recovery weighted images, the hyperintense "ring sign" and internal septation of the lesion were seen in 9 cases. Eight tumors had well-demarcated borders. Peritumoral edema or mass effect was absent in all cases. A contrast enhancement examination was performed in 9 cases. Contrast enhancement was absent in five cases, and four cases showed significant enhancement. The MRS showed a low N-acetylaspartate peak and a lack of elevated choline-containing component (Cho) or Cho-Cr ratio (Cho/Cr) in five patients.Conclusions The MRI findings of DNTs were stereotypical. The combination of MRI and MRS techniques were helpful in making a correct presurgical diagnosis.

  18. Elucidation of Chemical Reactions by Two-Dimensional Resonance Raman Spectroscopy

    Science.gov (United States)

    Moran, Andrew

    Two-dimensional (2D) Raman spectroscopies were proposed by Mukamel and Loring in1985 as a method for resolving line broadening mechanisms of vibrational motions in liquids. Significant technical issues challenged the development of both five- and seven-pulse 2D Raman spectroscopies. For this reason, 2D Raman experiments were largely abandoned in 2002 following the first demonstrations of 2D infrared spectroscopies (i.e., an alternate approach for obtaining similar information). We have recently shown that 2D Raman experiments conducted under electronically resonant conditions are much less susceptible to the problems encountered in the earlier 2D Raman work, which was carried out off-resonance. In effect, Franck-Condon activity obviates the problematic selection rules encountered under electronically off-resonant conditions. In this presentation, I will discuss applications of 2D resonance Raman spectroscopies to photodissocation reactions of triiodide and myoglobin. It will be shown that vibrational resonances of the reactants and products can be displayed in separate dimensions of a 2D resonance Raman spectrum when the photo-dissociation reaction is fast compared to the vibrational period. Such 2D spectra expose correlations between the nonequilibrium geometry of the reactant and the distribution of vibrational quanta in the product, thereby yielding insight in the photo-dissociation mechanism. Our results suggest that the ability of 2D resonance Raman spectroscopy to detect correlations between reactants and products will generalize to other ultrafast processes such as electron transfer and energy transfer.

  19. Spin measurement and neutron resonance spectroscopy for ^155Gd

    Science.gov (United States)

    Baramsai, Bayarbadrakh; Mitchell, G. E.; Chyzh, A.; Dashdorj, D.; Walker, C.; Bredeweg, T. A.; Couture, A.; Haight, R. C.; Jandel, M.; Keksis, A. L.; O'Donnell, J. M.; Rundberg, R. S.; Wouters, J. M.; Ullmann, J. L.; Viera, D. J.; Agvaanluvsan, U.; Becvar, F.; Krticka, M.

    2009-05-01

    The ^155Gd(n,γ) reaction has been measured with the DANCE calorimeter at Los Alamos Neutron Science Center. The highly segmented calorimeter provided detailed multiplicity distributions of the capture γ - rays. With this information the spins of the neutron capture resonances have been determined. The improved sensitivity of this method allowed the determination of the spins of even weak and unresolved resonances. With these new spin assignments as well as previously determined resonance parameters, level spacings and neutron strength functions are determined separately for s-wave resonances with J = 1 and 2.

  20. Fast Fourier Transform Chlorine Nuclear Quadrupole Resonance Spectroscopy.

    Science.gov (United States)

    D'Iorio, Marie

    A nuclear quadrupole resonance spectrometer operating in the frequency range 1-40 MHz was updated for fast Fourier transform spectroscopy and coupled to a Nicolet 1180 computer and data acquisition system. It was used with a low temperature cryostat for studies shown down to liquid helium temperature and with a high pressure/low temperature system for studies down to liquid nitrogen temperature and up to six kilobars. The study of the ('35)Cl NQR spectrum of K(,2)OsCl(,6) at 298 K and 77 K revealed the presence of a satellite associated with the nearest neighbour chlorines to H('+) ion impurities located at vacant octahedral sties. This result is in agreement with the predictions of a point charge model calculation. A residence time for the H('+) ion was deduced and is consistent with the result obtained from dielectric measurements. A detailed study of the ('35)Cl NQR frequency in K(,2)ReCl(,6) was performed in the temperature range 85 - 130K where two structural phase transitions occur, and at pressures from 1 to 2643 bars. A number of unusual features were revealed and discussed as the possible signature of incommensurate behavior. The primary effect of the pressure was to alter the temperatures at which the phase transitions occurred. Contrary to the behavior expected, the transition temperature for the antiferrorotative transition has a negative pressure coefficient. The spin-lattice and spin-spin relaxation times for the ('35)Cl and ('37)Cl isotopes of the one dimensional XY system, PrCl(,3), were measured at 4.2K. The spin-lattice relaxation is exponential and dominated by magnetic dipole -dipole interactions. The spin-spin relaxation is non-exponential and dominated by electric quadrupolar interactions arising from the coupling of the electric dipole moment at the praseodymium site and the quadrupole moment of the chlorine ion. The temperature dependence of the spin-spin relaxation time was investigated. At 17.4 K both magnetic dipolar and electric

  1. Muscle metabolism from near infrared spectroscopy during rhythmic handgrip in humans

    DEFF Research Database (Denmark)

    Boushel, Robert Christopher; Pott, F; Madsen, P

    1998-01-01

    The rate of metabolism in forearm flexor muscles (MO2) was derived from near-infrared spectroscopy (NIRS-O2) during ischaemia at rest rhythmic handgrip at 15% and 30% of maximal voluntary contraction (MVC), post-exercise muscle ischaemia (PEMI), and recovery in seven subjects. The MO2 was compare....... To conclude, NIRS-O2 of forearm flexor muscles closely reflected the exercise intensity and the metabolic rate determined by magnetic resonance spectroscopy but not that rate derived from flow and the arterio-venous oxygen difference.......The rate of metabolism in forearm flexor muscles (MO2) was derived from near-infrared spectroscopy (NIRS-O2) during ischaemia at rest rhythmic handgrip at 15% and 30% of maximal voluntary contraction (MVC), post-exercise muscle ischaemia (PEMI), and recovery in seven subjects. The MO2 was compared...... with forearm oxygen uptake (VO2) [flow x (oxygen saturation in arnterial blood-oxygen saturation in venous blood, SaO2 - SvO2)], and with the 31P-magnetic resonance spectroscopy-determined ratio of inorganic phosphate to phosphocreatine (P(I):PCr). During ischaemia at rest, the fall in NIRS-O2 was more...

  2. 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...

  3. 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)

  4. Proton resonance spectroscopy. Final performance report, June 1987--May 1996

    Energy Technology Data Exchange (ETDEWEB)

    Shriner, J.F. Jr.

    1998-09-01

    This report gives a brief summary of accomplishments made on this project. Approximately 22 refereed papers were published with support from this grant; reprints are attached with this report. Topics studied include amplitude distributions in proton resonance reactions, chaos in nuclei, and tests of detailed balance and of parity violation with resonance reactions. Appendix 1 lists personnel and collaborators associated with this work, including the undergraduate students hired with grant funds, while Appendix 2 provides a list of talks, abstracts, dissertations and theses, etc. associated with the work supported by this grant.

  5. 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...... in relaxation times, and can be used to estimate the fat concentration over the full range of fat content in contrast to the spectroscopic imaging methods. Localized spectroscopy may replace liver biopsy in the diagnosis of diffuse fatty infiltrations, and can be used for follow-up, due to its noninvasive...

  6. Resonant CARS Spectroscopy of s-Tetrazine Vapour

    NARCIS (Netherlands)

    Aartsma, Thijs J.; Hesselink, Wim H.; Wiersma, Douwe A.

    1980-01-01

    CARS experiments on s-tetrazine vapour show that the eletronic resonance enhancement in the Q-branch is most effective for the lower J values. This suggests that the radiationless relaxation rate in the excited state increases with rotational quantum number. Delayed picosecond CARS experiments indic

  7. 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 r

  8. 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...

  9. Methylmercury chloride damage to the adult rat hippocampus cannot be detected by proton magnetic resonance spectroscopy

    Institute of Scientific and Technical Information of China (English)

    Zhiyan Lu; Jinwei Wu; Guangyuan Cheng; Jianying Tian; Zeqing Lu; Yongyi Bi

    2014-01-01

    Previous studies have found that methylmercury can damage hippocampal neurons and accord-ingly cause cognitive dysfunction. However, a non-invasive, safe and accurate detection method for detecting hippocampal injury has yet to be developed. This study aimed to detect methylmer-cury-induced damage on hippocampal tissue using proton magnetic resonance spectroscopy. Rats were given a subcutaneous injection of 4 and 2 mg/kg methylmercury into the neck for 50 consecutive days. Water maze and pathology tests confirmed that cognitive function had been impaired and that the ultrastructure of hippocampal tissue was altered after injection. The results of proton magnetic resonance spectroscopy revealed that the nitrogen-acetyl aspartate/creatine, choline complex/creatine and myoinositol/creatine ratio in rat hippocampal tissue were unchanged. Therefore, proton magnetic resonance spectroscopy can not be used to determine structural damage in the adult rat hippocampus caused by methylmercury chloride.

  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...... to minimize motional artifacts from cardiac and lung motion that cause significant problems in frequency-domain spectral acquisition, such as in continuous wave (cw) EPR techniques...

  11. Visualization of subsurface nanoparticles in a polymer matrix using resonance tracking atomic force acoustic microscopy and contact resonance spectroscopy

    Science.gov (United States)

    Kimura, Kuniko; Kobayashi, Kei; Yao, Atsushi; Yamada, Hirofumi

    2016-10-01

    A visualization technique of subsurface features with a nanometer-scale spatial resolution is strongly demanded. Some research groups have demonstrated the visualization of subsurface features using various techniques based on atomic force microscopy. However, the imaging mechanisms have not yet been fully understood. In this study, we demonstrated the visualization of subsurface Au nanoparticles buried in a polymer matrix 900 nm from the surface using two techniques; i.e., resonance tracking atomic force acoustic microscopy and contact resonance spectroscopy. It was clarified that the subsurface features were visualized by the two techniques as the area with a higher contact resonance frequency and a higher Q-factor than those in the surrounding area, which suggests that the visualization is realized by the variation of the contact stiffness and damping of the polymer matrix due to the existence of the buried nanoparticles.

  12. Resonance Spectra of Caged Stringy Black Hole and Its Spectroscopy

    CERN Document Server

    Sakalli, I

    2015-01-01

    The Maggiore's method (MM), which evaluates the transition frequency that appears in the adiabatic invariant from the highly damped quasinormal mode (QNM) frequencies, is used to investigate the entropy/area spectra of the Garfinkle--Horowitz--Strominger black hole (GHSBH). Instead of the ordinary QNMs, we compute the boxed QNMs (BQNMs) that are the characteristic resonance spectra of the confined scalar fields in the GHSBH geometry. For this purpose, we assume that the GHSBH has a confining cavity (mirror) placed in the vicinity of the event horizon. We then show how the complex resonant frequencies of the caged GHSBH are computed using the Bessel differential equation that arises when the scalar perturbations around the event horizon are considered. Although the entropy/area is characterized by the GHSBH parameters, their quantization is shown to be independent of those parameters. However, both spectra are equally spaced.

  13. Resonance Spectra of Caged Stringy Black Hole and Its Spectroscopy

    Directory of Open Access Journals (Sweden)

    I. Sakalli

    2015-01-01

    quasinormal mode (QNM frequencies, is used to investigate the entropy/area spectra of the Garfinkle–Horowitz–Strominger black hole (GHSBH. Instead of the ordinary QNMs, we compute the boxed QNMs (BQNMs that are the characteristic resonance spectra of the confined scalar fields in the GHSBH geometry. For this purpose, we assume that the GHSBH has a confining cavity (mirror placed in the vicinity of the event horizon. We then show how the complex resonant frequencies of the caged GHSBH are computed using the Bessel differential equation that arises when the scalar perturbations around the event horizon are considered. Although the entropy/area is characterized by the GHSBH parameters, their quantization is shown to be independent of those parameters. However, both spectra are equally spaced.

  14. Modulation scheme for electron-electron double resonance spectroscopy

    Science.gov (United States)

    Mehlkopf, A. F.; Kuiper, F. G.; Smidt, J.; Tiggelman, T. A.

    1983-06-01

    A modulation scheme for electron-electron double resonance (ELDOR) spectrometers is presented. With this scheme an optimum stabilization signal for locking the pump microwave generator to the pumped electron paramagnetic resonance (EPR) line is generated. A separate pump power level and a separate magnetic field modulation amplitude are used for the purpose of locking. In general, such a modulation scheme introduces false ELDOR lines. These false lines disturb the real ELDOR signals, or introduce an ELDOR signal in the absence of any communication between the observed EPR line and the pumped EPR line. With the described modulation scheme the frequencies of the false ELDOR signals are limited to even multiples of the frequency of the wanted ELDOR signals. This makes a suppression of the false ELDOR lines easy.

  15. Advances in Zero-Field Nuclear Magnetic Resonance Spectroscopy

    OpenAIRE

    Theis, Thomas

    2012-01-01

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

  16. Active plasma resonance spectroscopy: a functional analytic description

    Science.gov (United States)

    Lapke, M.; Oberrath, J.; Mussenbrock, T.; Brinkmann, R. P.

    2013-04-01

    The term ‘active plasma resonance spectroscopy’ denotes a class of diagnostic methods which employ the ability of plasmas to resonate on or near the plasma frequency. The basic idea dates back to the early days of discharge physics: a signal in the GHz range is coupled to the plasma via an electrical probe; the spectral response is recorded, and then evaluated with a mathematical model to obtain information on the electron density and other plasma parameters. In recent years, the concept has found renewed interest as a basis of industry compatible plasma diagnostics. This paper analyzes the diagnostic technique in terms of a general description based on functional analytic (or Hilbert Space) methods which hold for arbitrary probe geometries. It is shown that the response function of the plasma-probe system can be expressed as a matrix element of the resolvent of an appropriately defined dynamical operator. A specialization of the formalism to a symmetric probe design is given, as well as an interpretation in terms of a lumped circuit model consisting of series resonance circuits. We present ideas for an optimized probe design based on geometric and electrical symmetry.

  17. 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.

  18. Glutamate-based magnetic resonance spectroscopy in neuroleptic malignant syndrome

    Directory of Open Access Journals (Sweden)

    Atri Chatterjee

    2014-01-01

    Full Text Available Glutamate neurotoxicity is implicated in a number of neurological diseases, including Neuroleptic Malignant syndrome. Therefore, functional magnetic resonance imaging can help in diagnosis and monitoring such conditions. However, reports of this application are scarce in the literature. In this manuscript, glutamate based imaging of the basal ganglia showed increased levels of the neurotransmitter bilaterally. In addition, a radon transform of the functional image was performed to look for any asymmetry in cerebral activation. Although no asymmetry was detected in this case, this novel analysis can be applied in physiological and pathological scenarios to visualize contribution of different brain structures.

  19. 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

  20. 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

  1. 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.

  2. Proton magnetic resonance spectroscopy in brain tumours: clinical applications

    Energy Technology Data Exchange (ETDEWEB)

    Burtscher, I.M.; Holtaas, S. [Lund Univ. (Sweden). Dept. of Diagnostic Radiology

    2001-05-01

    Parallel to the rapid development of clinical MRI, MR spectroscopy (MRS) has, after starting as an analytical tool used in chemistry and physics, evolved to a noninvasive clinical examination. Most common neuroradiological diagnostic indications for MRS are functional inborn errors, neonatal hypoxia, ischaemia, metabolic diseases, white matter and degenerative diseases, epilepsy, inflammation, infections and intracranial neoplasm. Compared to CT and MRI, well-established morphological diagnostic tools, MRS provides information on the metabolic state of brain tissue. We review the clinical impact of MRS in diagnosis of tumours and their differentiation from non-neoplastic lesions. (orig.)

  3. Dynamic measurement of temperature using neutron resonance spectroscopy (NRS)

    Energy Technology Data Exchange (ETDEWEB)

    Funk, D.J.; Asay, B.W.; Bennett, B.I.; Bowman, J.D.; Boat, R.M.; Dickson, P.M.; Henson, B.F.; Hull, L.M.; Idar, D.J.; Laabs, G.W.; London, R.K.; Mace, J.L.; Morgan, G.L.; Murk, D.M.; Rabie, R.L.; Ragan, C.E.; Stacy, H.L.; Yuan, V.W. [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)

    1998-07-01

    Accurate temperature measurements in dynamic systems have been pursued for decades and have usually relied on optical techniques. These approaches are generally hampered by insufficient information regarding the emissivity of the system under study. We are developing NRS techniques to measure temperature in dynamic systems and overcome these limitations. Many neutron resonances have narrow intrinsic Breit-Wigner widths such that the resonance is substantially broadened by the atomic motion even at room temperature. Thus, accurate measurement of the Doppler contribution allows one to infer the material temperature, and for the conditions achieved using standard high explosives, the probe itself is not perturbed by the high temperature and pressure. Experiments are conducted using a pulsed spallation source at LANSCE with time-of-flight measurement of the neutron spectra. In initial experiments, we have demonstrated that measurements with ten percent accuracy are possible. We have fielded dynamic tests, most of which were neutron-flux limited. An overview of the approach and the status of our experimental campaign are discussed. {copyright} {ital 1998 American Institute of Physics.}

  4. Resonantspectroscopy of solid-density aluminum plasmas.

    Science.gov (United States)

    Cho, B I; Engelhorn, K; Vinko, S M; Chung, H-K; Ciricosta, O; Rackstraw, D S; Falcone, R W; Brown, C R D; Burian, T; Chalupský, J; Graves, C; Hájková, V; Higginbotham, A; Juha, L; Krzywinski, J; Lee, H J; Messersmidt, M; Murphy, C; Ping, Y; Rohringer, N; Scherz, A; Schlotter, W; Toleikis, S; Turner, J J; Vysin, L; Wang, T; Wu, B; Zastrau, U; Zhu, D; Lee, R W; Nagler, B; Wark, J S; Heimann, P A

    2012-12-14

    The x-ray intensities made available by x-ray free electron lasers (FEL) open up new x-ray matter interaction channels not accessible with previous sources. We report here on the resonant generation of Kα emission, that is to say the production of copious Kα radiation by tuning the x-ray FEL pulse to photon energies below that of the K edge of a solid aluminum sample. The sequential absorption of multiple photons in the same atom during the 80 fs pulse, with photons creating L-shell holes and then one resonantly exciting a K-shell electron into one of these holes, opens up a channel for the Kα production, as well as the absorption of further photons. We demonstrate rich spectra of such channels, and investigate the emission produced by tuning the FEL energy to the K-L transitions of those highly charged ions that have transition energies below the K edge of the cold material. The spectra are sensitive to x-ray intensity dependent opacity effects, with ions containing L-shell holes readily reabsorbing the Kα radiation.

  5. Basic Principles and Clinical Applications of Magnetic Resonance Spectroscopy in Neuroradiology.

    Science.gov (United States)

    Ulmer, Stephan; Backens, Martin; Ahlhelm, Frank J

    2016-01-01

    Magnetic resonance spectroscopy is a powerful tool to assist daily clinical diagnostics. This review is intended to give an overview on basic principles of the technology, discuss some of its technical aspects, and present typical applications in daily clinical routine in neuroradiology.

  6. Resonance Light-Scattering Spectroscopy Study on Interaction between Gold Colloid and Thiol Containing Pharmaceutical

    Institute of Scientific and Technical Information of China (English)

    Liu; Xiao-ling; Cai; Ru-xiu; 等

    2003-01-01

    In this paper, we used resonance light-scattering (RLS) spectroscopy to study the interaction betwwen thiolcontaining pharmaceutical and gold colloid. And for the first time, we proposed that this highly sensitive, gold colloidbased assay using RLS technique may have potential application in detecting thoil-containing substances.

  7. Resonance Light-Scattering Spectroscopy Study on Interaction between Gold Colloid and Thiol Containing Pharmaceutical

    Institute of Scientific and Technical Information of China (English)

    Liu Xiao-ling; Cai Ru-xiu; Yuan Hong

    2003-01-01

    In this paper, we used resonance light-scattering (RLS) spectroscopy to study the interaction between thiol-containing pharmaceutical and gold colloid. And for the first time, we proposed that this highly sensitive, gold colloid-based assay using RLS technique may have potential application in detecting thiol-containing substances.

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

    Science.gov (United States)

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

    2008-01-01

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

  9. 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 or...

  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...

  11. 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.

    2008-01-01

    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

  12. Resonance Raman Spectroscopy of Beta-Carotene and Lycopene: A Physical Chemistry Experiment.

    Science.gov (United States)

    Hoskins, L. C.

    1984-01-01

    Discusses the theory of resonance Raman (RR) spectroscopy as it applies to beta-carotene and lycopene pigments (found in tomatoes and carrots, respectively). Also discusses an experiment which demonstrates the theoretical principles involved. The experiment has been tested over a three-year period and has received excellent acceptance by physical…

  13. Reproducibility of 3.0 Tesla Magnetic Resonance Spectroscopy for Measuring Hepatic Fat Content

    NARCIS (Netherlands)

    van Werven, Jochem R.; Hoogduin, Johannes M.; Nederveen, Aart J.; van Vliet, Andre A.; Wajs, Ewa; Vandenberk, Petra; Stroes, Erik S. G.; Stoker, Jaap

    2009-01-01

    Purpose: To investigate reproducibility of proton magnetic resonance spectroscopy (H-1-MRS) to measure hepatic triglyceride content (HTGC). Materials and Methods: In 24 subjects, HTGC was evaluated using H-1-MRS at 3.0 Tesla. We studied "between-weeks" reproducibility and reproducibility of H-1-MRS

  14. 2p3d Resonant X-ray emission spectroscopy of cobalt compounds

    NARCIS (Netherlands)

    van Schooneveld, M.M.

    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 s

  15. Structure Determination of Natural Products by Nuclear Magnetic Resonance Spectroscopy

    Science.gov (United States)

    Li, Du.

    High-field NMR experiments were used to determine the full structures of six new natural products extracted from plants. These are: four saponins (PT-2, P1, P2 and P3) from the plant Alphitonia zizyphoides found in Samoa; one sesquiterpene (DF-4) from Douglas fir and one diterpene derivative (E-2) from a Chinese medicinal herb. By concerted use of various 1D and 2D NMR techniques, the structures of the above compounds were established and complete resonance assignments were achieved. The 2D INADEQUATE technique coupled with a computerized spectral analysis was extensively used. When carried out on concentrations as low as 60 mg of sample, this technique provided absolute confirmation of the assignments for 35 of the possible 53 C-C bonds for PT-2. On 30 mg of sample of E-21, it revealed 22 of 28 possible C-C bonds.

  16. 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 (view, a model for the 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.

  17. Resonance Ionization Spectroscopy of Cesium Atoms in a Cesium Heat Pipe

    Science.gov (United States)

    Ardis, Robert G.; Gardner, Bernard W.; Smith, R. Seth

    1997-11-01

    A Cesium Heat Pipe has been constructed to produce a cesium metal vapor for use in laser spectroscopy. The heat pipe consists of a 24 inch stainless steel pipe with 2 inch diameter calcium fluoride windows on each end. Electric heaters are used to control the cesium vapor pressure. An argon buffer gas is used to maintain high transmittance through the end windows. Sensors are used to monitor both temperature and pressure. A Nd:YAG-pumped dye laser system is used to probe the cesium atoms via resonance ionization spectroscopy. Details of the construction of the heat pipe and the experimental setup will be presented. The results of the resonance ionization spectroscopy will be discussed. This experimental setup can be utilized with undergraduates in courses such as Optics, Laser Physics, and Senior Laboratory/Research.

  18. 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.

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

    Science.gov (United States)

    Roberts, Jody A

    2003-05-01

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

  20. 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.

  1. Identification of irradiated cashew nut by electron paramagnetic resonance spectroscopy.

    Science.gov (United States)

    Sanyal, Bhaskar; Sajilata, M G; Chatterjee, Suchandra; Singhal, Rekha S; Variyar, Prasad S; Kamat, M Y; Sharma, Arun

    2008-10-01

    Cashew nut samples were irradiated at gamma-radiation doses of 0.25, 0.5, 0.75, and 1 kGy, the permissible dose range for insect disinfestation of food commodities. A weak and short-lived triplet (g = 2.004 and hfcc = 30 G) along with an anisotropic signal (g perpendicular = 2.0069 and g parallel = 2.000) were produced immediately after irradiation. These signals were assigned to that of cellulose and CO 2 (-) radicals. However, the irradiated samples showed a dose-dependent increase of the central line (g = 2.0045 +/- 0.0002). The nature of the free radicals formed during conventional processing such as thermal treatment was investigated and showed an increase in intensity of the central line (g = 2.0045) similar to that of irradiation. Characteristics of the free radicals were studied by their relaxation and thermal behaviors. The present work explores the possibility to identify irradiated cashew nuts from nonirradiated ones by the thermal behaviors of the radicals beyond the period, when the characteristic electron paramagnetic resonance spectral lines of the cellulose free radicals have essentially disappeared. In addition, this study for the first time reports that relaxation behavior of the radicals could be a useful tool to distinguish between roasted and irradiated cashew nuts.

  2. 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.

  3. 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)

  4. Experimental studies on perturbed acoustic resonant spectroscopy by a small rock sample in a cylindrical cavity

    Institute of Scientific and Technical Information of China (English)

    CHEN Dehua; WANG Xiuming; CONG Jiansheng; XU Delong; SONG Yanjie; MA Shuilong

    2006-01-01

    A measurement system for acoustic resonant spectroscopy (ARS) is established,and the effects of resonant cavity geometry,inner perturbation samples and environmental temperature on the ARS are investigated.The ARSs of the small samples with various sizes and acoustic properties are measured.The results show that at the normal pressure,the resonant frequency decreases gradually with the increase of liquid temperature in the cylindrical cavity,while the resonant amplitude increases.At certain pressure and temperature,both the resonant frequency and the amplitude decrease greatly when there exist air bubbles inside the cavity fluid.The ARS is apparently affected by the sample porosity and the sample location in the resonant cavity.At the middle of the cavity,the resonant frequencies reach their maximum values for all of the measurement samples.The resonant frequencies of the porous rock samples are smaller than those of the compacted samples if other acoustic parameters are the same.As the sample is moved from the top to the middle of the cavity along its axis,the resonant amplitude increases gradually for the compacted rocks while decreases for the unconsolidated rocks.Furthermore,the resonant amplitude increases firstly and then decreases if the porosity of the rock sample is relatively small.In addition,through the comparisons between the experimental and theoretical results,it is found that the effects of the acoustic parameters and sizes of the samples and the size of the cylindrical cavity on the laboratory results agree well with the theoretical ones qualitatively.These results may provide basic reference for the experiment study of rock acoustic properties in a low frequency using ARS.

  5. 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.

  6. Magnetic resonance spectroscopy of the brain: review of metabolites and clinical applications

    Energy Technology Data Exchange (ETDEWEB)

    Soares, D.P. [Section of Radiology, Department of Surgery, Radiology, Anaesthetics, and Intensive Care, University Hospital of the West Indies, Mona, Kingston (Jamaica)], E-mail: dpsoares@cwjamaica.com; Law, M. [Department of Radiology and Neurosurgery, Mount Sinai Medical Centre, New York, New York (United States)

    2009-01-15

    Magnetic resonance imaging (MRI) provides anatomic images and morphometric characterization of disease, whereas magnetic resonance spectroscopy (MRS) provides metabolite/biochemical information about tissues non-invasively in vivo. MRS has been used clinically for more than two decades. The major applications of this advanced MRI tool are in the investigation of neurological and neurosurgical disorders. MRS has also been used in the evaluation of the prostate gland and muscle tissue, but these applications will not be addressed in this review. The aim of this review is to attempt to introduce the technique, review the metabolites and literature, as well as briefly describe our clinical experience.

  7. Comparison among T1-Weighted Magnetic Resonance Imaging, Modified Dixon Method, and Magnetic Resonance Spectroscopy in Measuring Bone Marrow Fat

    Directory of Open Access Journals (Sweden)

    Wei Shen

    2013-01-01

    Full Text Available Introduction. An increasing number of studies are utilizing different magnetic resonance (MR methods to quantify bone marrow fat due to its potential role in osteoporosis. Our aim is to compare the measurements of bone marrow fat among T1-weighted magnetic resonance imaging (MRI, modified Dixon method (also called fat fraction MRI (FFMRI, and magnetic resonance spectroscopy (MRS. Methods. Contiguous MRI scans were acquired in 27 Caucasian postmenopausal women with a modified Dixon method (i.e., FFMRI. Bone marrow adipose tissue (BMAT of T1-weighted MRI and bone marrow fat fraction of the L3 vertebra and femoral necks were quantified using SliceOmatic and Matlab. MRS was also acquired at the L3 vertebra. Results. Correlation among the three MR methods measured bone marrow fat fraction and BMAT ranges from 0.78 to 0.88 in the L3 vertebra. Correlation between BMAT measured by T1-weighted MRI and bone marrow fat fraction measured by modified FFMRI is 0.86 in femoral necks. Conclusion. There are good correlations among T1-weighted MRI, FFMRI, and MRS for bone marrow fat quantification. The inhomogeneous distribution of bone marrow fat, the threshold segmentation of the T1-weighted MRI, and the ambiguity of the FFMRI may partially explain the difference among the three methods.

  8. High-field proton magnetic resonance spectroscopy reveals metabolic effects of normal brain aging.

    Science.gov (United States)

    Harris, Janna L; Yeh, Hung-Wen; Swerdlow, Russell H; Choi, In-Young; Lee, Phil; Brooks, William M

    2014-07-01

    Altered brain metabolism is likely to be an important contributor to normal cognitive decline and brain pathology in elderly individuals. To characterize the metabolic changes associated with normal brain aging, we used high-field proton magnetic resonance spectroscopy in vivo to quantify 20 neurochemicals in the hippocampus and sensorimotor cortex of young adult and aged rats. We found significant differences in the neurochemical profile of the aged brain when compared with younger adults, including lower aspartate, ascorbate, glutamate, and macromolecules, and higher glucose, myo-inositol, N-acetylaspartylglutamate, total choline, and glutamine. These neurochemical biomarkers point to specific cellular mechanisms that are altered in brain aging, such as bioenergetics, oxidative stress, inflammation, cell membrane turnover, and endogenous neuroprotection. Proton magnetic resonance spectroscopy may be a valuable translational approach for studying mechanisms of brain aging and pathology, and for investigating treatments to preserve or enhance cognitive function in aging.

  9. Billion-Fold Enhancement in Sensitivity of Nuclear Magnetic Resonance Spectroscopy for Magnesium Ions in Solution

    CERN Document Server

    Gottberg, Alexander; Kowalska, Magdalena; Bissell, Mark L; Arcisauskaite, Vaida; Blaum, Klaus; Helmke, Alexander; Johnston, Karl; Kreim, Kim; Larsen, Flemming H; Neugart, Rainer; Neyens, Gerda; Garcia Ruiz, Ronald F; Szunyogh, Daniel; Thulstrup, Peter W; Yordanov, Deyan T; Hemmingsen, Lars

    2014-01-01

    β-nuclear magnetic resonance (NMR) spectroscopy is highly sensitive compared to conventional NMR spectroscopy, and may be applied for several elements across the periodic table. β-NMR has previously been successfully applied in the fields of nuclear and solid-state physics. In this work, β-NMR is applied, for the first time, to record an NMR spectrum for a species in solution. 31Mg β-NMR spectra are measured for as few as 107 magnesium ions in ionic liquid (EMIM-Ac) within minutes, as a prototypical test case. Resonances are observed at 3882.9 and 3887.2 kHz in an external field of 0.3 T. The key achievement of the current work is to demonstrate that β-NMR is applicable for the analysis of species in solution, and thus represents a novel spectroscopic technique for use in general chemistry and potentially in biochemistry.

  10. Neurochemical metabolites in the medial prefrontal cortex in bipolar disorder A proton magnetic resonance spectroscopy study

    Institute of Scientific and Technical Information of China (English)

    Osman (O)zdel; Demet Kalayci; Gülfizar S(o)zeri-Varma; Yilmaz Kiro(g)lu; Selim Tümkaya; Tu(g)(c)e Toker-U(g)urlu

    2012-01-01

    The aim of this study was to investigate proton magnetic resonance spectroscopy metabolite values in the medial prefrontal cortex of individuals with euthymic bipolar disorder. The subjects consisted of 15 patients with euthymic bipolar disorder type I and 15 healthy controls. We performed proton magnetic resonance spectroscopy of the bilateral medial prefrontal cortex and measured levels of N-acetyl aspartate, choline and creatine. Levels of these three metabolites in the medial prefrontal cortex were found to be lower in patients with bipolar disorder compared with healthy controls. A positive correlation was found between illness duration and choline levels in the right medial prefrontal cortex. Our study suggests that during the euthymic period, there are abnormalities in cellular energy and membrane phospholipid metabolism in the medial prefrontal cortex, and that this may impair neuronal activity and integrity.

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

    Science.gov (United States)

    Lovchinsky, I; Sushkov, A O; Urbach, E; de Leon, N P; Choi, S; De Greve, K; Evans, R; Gertner, R; Bersin, E; Müller, C; McGuinness, L; Jelezko, F; Walsworth, R L; Park, H; Lukin, M D

    2016-02-19

    Nuclear magnetic resonance spectroscopy is a powerful tool for the structural analysis of organic compounds and biomolecules but typically requires macroscopic sample quantities. We use a sensor, which consists of two quantum bits corresponding to an electronic spin and an ancillary nuclear spin, to demonstrate room temperature magnetic resonance detection and spectroscopy of multiple nuclear species within individual ubiquitin proteins attached to the diamond surface. Using quantum logic to improve readout fidelity and a surface-treatment technique to extend the spin coherence time of shallow nitrogen-vacancy centers, we demonstrate magnetic field sensitivity sufficient to detect individual proton spins within 1 second of integration. This gain in sensitivity enables high-confidence detection of individual proteins and allows us to observe spectral features that reveal information about their chemical composition.

  12. Billion-fold enhancement in sensitivity of nuclear magnetic resonance spectroscopy for magnesium ions in solution.

    Science.gov (United States)

    Gottberg, Alexander; Stachura, Monika; Kowalska, Magdalena; Bissell, Mark L; Arcisauskaite, Vaida; Blaum, Klaus; Helmke, Alexander; Johnston, Karl; Kreim, Kim; Larsen, Flemming H; Neugart, Rainer; Neyens, Gerda; Garcia Ruiz, Ronald F; Szunyogh, Daniel; Thulstrup, Peter W; Yordanov, Deyan T; Hemmingsen, Lars

    2014-12-15

    β-nuclear magnetic resonance (NMR) spectroscopy is highly sensitive compared to conventional NMR spectroscopy, and may be applied for several elements across the periodic table. β-NMR has previously been successfully applied in the fields of nuclear and solid-state physics. In this work, β-NMR is applied, for the first time, to record an NMR spectrum for a species in solution. (31)Mg β-NMR spectra are measured for as few as 10(7) magnesium ions in ionic liquid (EMIM-Ac) within minutes, as a prototypical test case. Resonances are observed at 3882.9 and 3887.2 kHz in an external field of 0.3 T. The key achievement of the current work is to demonstrate that β-NMR is applicable for the analysis of species in solution, and thus represents a novel spectroscopic technique for use in general chemistry and potentially in biochemistry.

  13. Biochemical Support for the “Threshold” Theory of Creativity: A Magnetic Resonance Spectroscopy Study

    OpenAIRE

    2009-01-01

    A broadly accepted definition of creativity refers to the production of something both novel and useful within a given social context. Studies of patients with neurological and psychiatric disorders and neuroimaging studies of healthy controls have each drawn attention to frontal and temporal lobe contributions to creativity. Based on previous magnetic resonance (MR) spectroscopy studies demonstrating relationships between cognitive ability and concentrations of N-acetyl-aspartate (NAA), a co...

  14. 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...

  15. Magnetic resonance spectroscopy to study hepatic metabolism in diffuse liver diseases, diabetes and cancer

    Institute of Scientific and Technical Information of China (English)

    Pieter; C; Dagnelie; Susanne; Leij-Halfwerk

    2010-01-01

    This review provides an overview of the current state of the art of magnetic resonance spectroscopy (MRS) in in vivo investigations of diffuse liver disease. So far, MRS of the human liver in vivo has mainly been used as a research tool rather than a clinical tool. The liver is particularly suitable for static and dynamic metabolic studies due to its high metabolic activity. Furthermore, its relatively superfi cial position allows excellent MRS localization, while its large volume allows detection of signal...

  16. Using Electron Paramagnetic Resonance Spectroscopy To Facilitate Problem Solving in Pharmaceutical Research and Development.

    Science.gov (United States)

    Mangion, Ian; Liu, Yizhou; Reibarkh, Mikhail; Williamson, R Thomas; Welch, Christopher J

    2016-08-19

    As new chemical methodologies driven by single-electron chemistry emerge, process and analytical chemists must develop approaches to rapidly solve problems in this nontraditional arena. Electron paramagnetic resonance spectroscopy has been long known as a preferred technique for the study of paramagnetic species. However, it is only recently finding application in contemporary pharmaceutical development, both to study reactions and to track the presence of undesired impurities. Several case studies are presented here to illustrate its utility in modern pharmaceutical development efforts.

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

    Science.gov (United States)

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

    2000-08-01

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

  18. Magnetic Resonance Imaging and Magnetic Resonance Spectroscopy Characterize a Rodent Model of Covert Stroke

    Science.gov (United States)

    Herrera, Sheryl Lyn

    Covert stroke (CS) comprises lesions in the brain often associated by risk factors such as a diet high in fat, salt, cholesterol and sugar (HFSCS). Developing a rodent model for CS incorporating these characteristics is useful for developing and testing interventions. The purpose of this thesis was to determine if magnetic resonance (MR) can detect brain abnormalities to confirm this model will have the desired anatomical effects. Ex vivo MR showed brain abnormalities for rats with the induced lesions and fed the HFSCS diet. Spectra acquired on the fixed livers had an average percent area under the fat peak relative to the water peak of (20+/-4)% for HFSCS and (2+/-2)% for control. In vivo MR images had significant differences between surgeries to induce the lesions (p=0.04). These results show that applying MR identified abnormalities in the rat model and therefore is important in the development of this CS rodent model.

  19. Photonic crystal waveguides intersection for resonant quantum dot optical spectroscopy detection.

    Science.gov (United States)

    Song, Xiaohong; Declair, Stefan; Meier, Torsten; Zrenner, Artur; Förstner, Jens

    2012-06-18

    Using a finite-difference time-domain method, we theoretically investigate the optical spectra of crossing perpendicular photonic crystal waveguides with quantum dots embedded in the central rod. The waveguides are designed so that the light mainly propagates along one direction and the cross talk is greatly reduced in the transverse direction. It is shown that when a quantum dot (QD) is resonant with the cavity, strong coupling can be observed via both the transmission and crosstalk spectrum. If the cavity is far off-resonant from the QD, both the cavity mode and the QD signal can be detected in the transverse direction since the laser field is greatly suppressed in this direction. This structure could have strong implications for resonant excitation and in-plane detection of QD optical spectroscopy.

  20. Perforated SiN membrane resonators for nanomechanical IR spectroscopy poster

    DEFF Research Database (Denmark)

    Kurek, Maksymilian; Carnoy, Matthias; Boisen, Anja

    behavior. The principle of operation is based on the monitoring of the resonance frequency shift dueto various external factors such as change of temperature. It has been shown that photothermal infrared (IR) spectroscopy based onnanomechanical silicon nitride (SiN) string resonators (NAM-IR) enables...... the exceptionally fast chemical analysis of pictograms of analytedirectly from liquid solution in only a few minutes [1]. However in this technique the coupling of the IR laser beam to the nanometerwidestring resonators is difficult and inefficient. Therefore perforated SiN membranes with thickness of 100 nm......, lateral dimension of1×1 mm2 and 2 µm perforation grid pitch were used instead of strings which makes the IR beam alignment significantly simpler whilemaintaining similar sampling efficiency and photothermal IR absorption sensitivity....

  1. 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...... be proportionally improved by increasing the length of the optical fiber ring resonator....... of the fiber ring resonator can be measured with the transmission spectrum. A good linearity is obtained between displacement and the inverse of wavelength spacing with an R2 of 0.9989, and high sensitivities better than 40  pm/με within the range of 0 to 10  με are achieved. The sensitivity can...

  2. Quanty for core level spectroscopy - excitons, resonances and band excitations in time and frequency domain

    Science.gov (United States)

    Haverkort, Maurits W.

    2016-05-01

    Depending on the material and edge under consideration, core level spectra manifest themselves as local excitons with multiplets, edge singularities, resonances, or the local projected density of states. Both extremes, i.e., local excitons and non-interacting delocalized excitations are theoretically well under control. Describing the intermediate regime, where local many body interactions and band-formation are equally important is a challenge. Here we discuss how Quanty, a versatile quantum many body script language, can be used to calculate a variety of different core level spectroscopy types on solids and molecules, both in the frequency as well as the time domain. The flexible nature of Quanty allows one to choose different approximations for different edges and materials. For example, using a newly developed method merging ideas from density renormalization group and quantum chemistry [1-3], Quanty can calculate excitons, resonances and band-excitations in x-ray absorption, photoemission, x-ray emission, fluorescence yield, non-resonant inelastic x-ray scattering, resonant inelastic x-ray scattering and many more spectroscopy types. Quanty can be obtained from: http://www.quanty.org.

  3. 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.

  4. High-Frequency Electron Paramagnetic Resonance Spectroscopy of Nitroxide-Functionalized Nanodiamonds in Aqueous Solution.

    Science.gov (United States)

    Akiel, R D; Stepanov, V; Takahashi, S

    2016-06-21

    Nanodiamond (ND) is an attractive class of nanomaterial for fluorescent labeling, magnetic sensing of biological molecules, and targeted drug delivery. Many of those applications require tethering of target biological molecules on the ND surface. Even though many approaches have been developed to attach macromolecules to the ND surface, it remains challenging to characterize dynamics of tethered molecule. Here, we show high-frequency electron paramagnetic resonance (HF EPR) spectroscopy of nitroxide-functionalized NDs. Nitroxide radical is a commonly used spin label to investigate dynamics of biological molecules. In the investigation, we developed a sample holder to overcome water absorption of HF microwave. Then, we demonstrated HF EPR spectroscopy of nitroxide-functionalized NDs in aqueous solution and showed clear spectral distinction of ND and nitroxide EPR signals. Moreover, through EPR spectral analysis, we investigate dynamics of nitroxide radicals on the ND surface. The demonstration sheds light on the use of HF EPR spectroscopy to investigate biological molecule-functionalized nanoparticles.

  5. Quantification of total pigments in citrus essential oils by thermal wave resonant cavity photopyroelectric spectroscopy.

    Science.gov (United States)

    López-Muñoz, Gerardo A; Antonio-Pérez, Aurora; Díaz-Reyes, J

    2015-05-01

    A general theory of thermal wave resonant cavity photopyroelectric spectroscopy (TWRC-PPE) was recently proposed by Balderas-López (2012) for the thermo-optical characterisation of substances in a condensed phase. This theory is used to quantify the total carotenoids and chlorophylls in several folded and un-folded citrus essential oils to demonstrate the viability of using this technique as an alternative analytical method for the quantification of total pigments in citrus oils. An analysis of variance (ANOVA) reveals significant differences (p spectroscopy can be used to quantify concentrations up to five times higher of total carotenoids and chlorophylls in citrus oils than UV-Vis spectroscopy without sample preparation or dilution. The optical limits of this technique and possible interference are also described.

  6. Superconducting Pb stripline resonators in parallel magnetic field and their application for microwave spectroscopy

    Science.gov (United States)

    Ebensperger, Nikolaj G.; Thiemann, Markus; Dressel, Martin; Scheffler, Marc

    2016-11-01

    Planar superconducting microwave resonators are key elements in a variety of technical applications and also act as sensitive probes for microwave spectroscopy of various materials of interest in present solid state research. Here superconducting Pb is a suitable material as a basis for microwave stripline resonators. To utilize Pb stripline resonators in a variable magnetic field (e.g. in ESR measurements), the electrodynamics of such resonators in a finite magnetic field has to be fully understood. Therefore we performed microwave transmission measurements (with ample applied power to work in linear response) on superconducting Pb stripline resonators in a variable, parallel magnetic field. We determined surface resistance, penetration depth, as well as real and imaginary parts, {σ }1 and {σ }2, of the complex conductivity of superconducting Pb as a function of a magnetic field. Here we find features reminiscent of those in temperature-dependent measurements, such as a maximum in {σ }1 (coherence peak). At magnetic fields above the critical field of this type-I superconductor we still find a low-loss microwave response, which we assign to remaining superconductivity in the form of filaments within the Pb. Hysteresis effects are found in the quality factor of resonances once the swept magnetic field has exceeded the critical magnetic field. This is due to normal conducting areas that are pinned and can therefore persist in the superconducting phase. Besides zero-field-cooling we show an alternative way to eliminate these even at T\\lt {T}c. Based on our microwave data, we also determine the critical magnetic field and the critical temperature of Pb in a temperature range between 1.6 K and 6.5 K and magnetic fields up to 140 mT, showing good agreement with BCS predictions. We also study a Sn sample in a Pb resonator to demonstrate the applicability of superconducting Pb stripline resonators in the experimental study of other (super-)conducting materials in a

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

    Science.gov (United States)

    Cleveland, Zackary I.

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

  8. 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.)

  9. 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.

  10. Maturation of limbic regions in Asperger syndrome: a preliminary study using proton magnetic resonance spectroscopy and structural magnetic resonance imaging.

    Science.gov (United States)

    O'Brien, Finian M; Page, Lisa; O'Gorman, Ruth L; Bolton, Patrick; Sharma, Ajay; Baird, Gillian; Daly, Eileen; Hallahan, Brian; Conroy, Ronán M; Foy, Catherine; Curran, Sarah; Robertson, Dene; Murphy, Kieran C; Murphy, Declan G M

    2010-11-30

    People with autistic spectrum disorders (ASD, including Asperger syndrome) may have developmental abnormalities in the amygdala-hippocampal complex (AHC). However, in vivo, age-related comparisons of both volume and neuronal integrity of the AHC have not yet been carried out in people with Asperger syndrome (AS) versus controls. We compared structure and metabolic activity of the right AHC of 22 individuals with AS and 22 healthy controls aged 10-50 years and examined the effects of age between groups. We used structural magnetic resonance imaging (sMRI) to measure the volume of the AHC, and magnetic resonance spectroscopy ((1)H-MRS) to measure concentrations of N-acetyl aspartate (NAA), creatine+phosphocreatine (Cr+PCr), myo-inositol (mI) and choline (Cho). The bulk volume of the amygdala and the hippocampus did not differ significantly between groups, but there was a significant difference in the effect of age on the hippocampus in controls. Compared with controls, young (but not older) people with AS had a significantly higher AHC concentration of NAA and a significantly higher NAA/Cr ratio. People with AS, but not controls, had a significant age-related reduction in NAA and the NAA/Cr ratio. Also, in people with AS, but not controls, there was a significant relationship between concentrations of choline and age so that choline concentrations reduced with age. We therefore suggest that people with AS have significant differences in neuronal and lipid membrane integrity and maturation of the AHC.

  11. Clinical relevance of magnetic resonance imaging and magnetic resonance spectroscopy for the cirrhotic without overt hepatic encephalopathy

    Energy Technology Data Exchange (ETDEWEB)

    Fujishima, Yukou; Kato, Akinobu; Suzuki, Kazuyuki [Iwate Medical Univ., Morioka (Japan). School of Medicine

    1999-04-01

    To clarify the changes of pallidal high intensity on T1-weighted magnetic resonance imaging (MRI) and brain metabolites on magnetic resonance spectroscopy (MRS) as related to the severity of hepatic functions, the concentrations of blood ammonia (B-NH{sub 3}) and the levels of trace elements (Mn, Cu and Zn), 30 patients with liver cirrhosis without hepatic encephalopathy (HE) and 5 age-matched healthy control subjects underwent MRI and proton MRS. Pallidal high intensity (Pl index) and glutamine are higher in cirrhosis, and myo-inositol is lower than that of control statistically. In cirrhosis, there were statistically negative correlation between B-NH{sub 3} and myo-inositol and positive correlation between B-NH{sub 3} and glutamine. There was a statistically lower myo-inositol and higher Pl index, glutamine as the severity of hepatic functions increased. Furthermore there was a statistically positive correlation between Pl index and Mn. These data suggest that the changes of MRI and MRS findings already detected in cirrhosis without HE and these abnormalities may be reflect the B-NH{sub 3} and Mn metabolism and the severity of the hepatic functions. (author)

  12. Multinuclear nanoliter one-dimensional and two-dimensional NMR spectroscopy with a single non-resonant microcoil

    NARCIS (Netherlands)

    Fratila, R.M.; Gomez, M.V.; Sykora, S.; Velders, A.H.

    2014-01-01

    Nuclear magnetic resonance (NMR) spectroscopy is a powerful analytical technique, but its low sensitivity and highly sophisticated, costly, equipment severely constrain more widespread applications. Here we show that a non-resonant planar transceiver microcoil integrated in a microfluidic chip (dete

  13. Localized proton magnetic resonance spectroscopy of the cerebellum in detoxifying alcoholics.

    Science.gov (United States)

    Seitz, D; Widmann, U; Seeger, U; Nägele, T; Klose, U; Mann, K; Grodd, W

    1999-01-01

    An increased daily alcohol consumption results in neurological symptoms and morphological central nervous system changes, e.g. shrinkage of the frontal lobes and the cerebellar vermis. Brain shrinkage can be due to neuronal loss, gliosis, or alterations of (cell) membrane constitutes/myelin. Neuronal, glial, and metabolic changes can be measured in vivo with proton magnetic resonance spectroscopy. A total of 11 alcoholics and 10 age-matched volunteers were examined by magnetic resonance imaging and localized magnetic resonance spectroscopy at an echo time of 135 and 5 msec. Peak integral values were calculated for N-acetylaspartate (NAA), choline (Cho), myo-inositol (ml), glutamate/glutamine (Glx), and normalized to phosphocreatine/creatine (Cr). Patients had a significant shrinkage of the cerebellar vermis. NAA/Cr and Cho/Cr ratios were reduced in both sequences, but the NAA/Cr reduction was only significant in long echo time, although the Cho/Cr reduction was significant in short echo time. The ml/Cr and Glx/Cr ratios did not show any significant difference between volunteers and patients. The decrease of NAA/Cr in alcohol dependent patients is consistent with neuronal loss. The Cho/Cr decrease and an unchanged ml/Cr may reflect cell membrane modification or myelin alterations in alcohol-dependent patients. These changes lead to brain shrinkage, although hydration effects and gliosis are less likely.

  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. 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.

  16. Monitoring lactic acid production during milk fermentation by in situ quantitative proton nuclear magnetic resonance spectroscopy.

    Science.gov (United States)

    Bouteille, R; Gaudet, M; Lecanu, B; This, H

    2013-04-01

    When fermenting milk, lactic bacteria convert part of α- and β-lactoses into d- and l- lactic acids, causing a pH decrease responsible for casein coagulation. Lactic acid monitoring during fermentation is essential for the control of dairy gel textural and organoleptic properties, and is a way to evaluate strain efficiency. Currently, titrations are used to follow the quantity of acids formed during jellification of milk but they are not specific to lactic acid. An analytical method without the use of any reagent was investigated to quantify lactic acid during milk fermentation: in situ quantitative proton nuclear magnetic resonance spectroscopy. Two methods using in situ quantitative proton nuclear magnetic resonance spectroscopy were compared: (1) d- and l-lactic acids content determination, using the resonance of their methyl protons, showing an increase from 2.06 ± 0.02 to 8.16 ± 0.74 g/L during 240 min of fermentation; and (2) the determination of the α- and β-lactoses content, decreasing from 42.68 ± 0.02 to 30.76 ± 1.75 g/L for the same fermentation duration. The ratio between the molar concentrations of produced lactic acids and consumed lactoses enabled cross-validation, as the value (2.02 ± 0.18) is consistent with lactic acid bacteria metabolism.

  17. [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 ms

  18. 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...

  19. The Role of Multivoxel H1 Magnetic Resonance Spectroscopy in the Diagnosis of Prostate Cancer

    Directory of Open Access Journals (Sweden)

    Mahyar Ghafoori

    2010-05-01

    Full Text Available Prostate cancer is the most common cancer diagnosed in men. Prostate cancer shows an insidious onset and screening programs are used worldwide for the early diagnosis of prostate cancer. Checking serum prostate specific antigen (PSA is most commonly used for this purpose. In the case of PSA elevation, the patients are routinely referred for transrectal ultrasonography-guided biopsy of the prostate. In some occasions despite several biopsy attempts, prostate cancer is not diagnosed."nMultivoxel H1 magnetic resonance spectroscopy (MRS of the prostate with the use of endorectal coils is a valuable method that aids in the diagnosis of prostate cancer. The peripheral zone of the prostate normally contains high concentrations of citrate and low amounts of choline. When the tumoral cells of prostate cancer grow within the peripheral zone, they substitute the normal cells and decrease the amount of citrate. On the other hand because of the high turnover of tumoral cells and their rapid growth, choline increases in the tumoral region. The result of these changes is elevation of the choline to citrate ratio in prostate cancer."nIn the multivoxel H1 magnetic resonance spectroscopy, we divide the prostate to multiple small voxels and measure the amount of choline and citrate in each volume and evaluate the choline to citrate ratio. In the normal regions this ratio is low (because of high citrate and low choline and in the region of tumor this ratio is high (because of low citrate and high choline. "nMultivoxel H1 Magnetic Resonance Spectroscopy (MRS of the prostate with the use of endorectal coil is a valuable method for diagnosis of prostate cancer.    

  20. The neurochemical basis of human cortical auditory processing: combining proton magnetic resonance spectroscopy and magnetoencephalography

    Directory of Open Access Journals (Sweden)

    Tollkötter Melanie

    2006-08-01

    Full Text Available Abstract Background A combination of magnetoencephalography and proton magnetic resonance spectroscopy was used to correlate the electrophysiology of rapid auditory processing and the neurochemistry of the auditory cortex in 15 healthy adults. To assess rapid auditory processing in the left auditory cortex, the amplitude and decrement of the N1m peak, the major component of the late auditory evoked response, were measured during rapidly successive presentation of acoustic stimuli. We tested the hypothesis that: (i the amplitude of the N1m response and (ii its decrement during rapid stimulation are associated with the cortical neurochemistry as determined by proton magnetic resonance spectroscopy. Results Our results demonstrated a significant association between the concentrations of N-acetylaspartate, a marker of neuronal integrity, and the amplitudes of individual N1m responses. In addition, the concentrations of choline-containing compounds, representing the functional integrity of membranes, were significantly associated with N1m amplitudes. No significant association was found between the concentrations of the glutamate/glutamine pool and the amplitudes of the first N1m. No significant associations were seen between the decrement of the N1m (the relative amplitude of the second N1m peak and the concentrations of N-acetylaspartate, choline-containing compounds, or the glutamate/glutamine pool. However, there was a trend for higher glutamate/glutamine concentrations in individuals with higher relative N1m amplitude. Conclusion These results suggest that neuronal and membrane functions are important for rapid auditory processing. This investigation provides a first link between the electrophysiology, as recorded by magnetoencephalography, and the neurochemistry, as assessed by proton magnetic resonance spectroscopy, of the auditory cortex.

  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. Observation of Kondo resonance in rare-earth hexaborides using high resolution photoemission spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Maiti, Kalobaran; Patil, Swapnil; Adhikary, Ganesh [Department of Condensed Matter Physics and Materials Science, Tata Institute of Fundamental Research, Homi Bhabha Road, Colaba, Mumbai 400005 (India); Balakrishnan, Geetha, E-mail: kbmaiti@tifr.res.in [Department of Physics, University of Warwick, Coventry, CV4 7AL (United Kingdom)

    2011-01-01

    We studied the electronic structure of rare earth hexaborides, CeB{sub 6}, PrB{sub 6} and NdB{sub 6} using state-of-the-art high resolution photoemission spectroscopy. CeB{sub 6} is a dense Kondo system. PrB{sub 6} and NdB{sub 6} are antiferromagnetic (Neel temperature {approx}7 K), known to be stable moment systems and do not exhibit Kondo effect. Photoemission spectra exhibit distinct signature of surface and bulk electronic structures of these compounds. The energy position of the surface feature is not influenced by the 4f density of states. High resolution spectra of CeB{sub 6} reveal multiple Kondo resonance features in the bulk spectra due to various photoemission final states. Interestingly, high resolution photoemission spectra of antiferromagnetic PrB{sub 6} also exhibit a sharp feature at the Fermi level that shows temperature dependence similar to the Kondo resonance features.

  3. 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.

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

    Energy Technology Data Exchange (ETDEWEB)

    Chang-Hwan Kim

    2003-12-12

    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.

  5. Coherent anti-Stokes Raman spectroscopy in the presence of strong resonant signal from background molecules

    CERN Document Server

    Bitter, Martin

    2012-01-01

    Optical spectroscopy with broadband femtosecond laser pulses often involves simultaneous excitation of multiple molecular species with close resonance frequencies. Interpreting the collective optical response from molecular mixtures typically requires Fourier analysis of the detected time-resolved signal. We propose an alternative method of separating coherent optical responses from two molecular species with neighboring excitation resonances (here, vibrational modes of oxygen and carbon dioxide). We utilize ro-vibrational coupling as a mechanism of suppressing the strong vibrational response from the dominating molecular species (O$_{2}$). Coherent ro-vibrational dynamics lead to long "silence windows" of zero signal from oxygen molecules. In these silence windows, the detected signal stems solely from the minority species (CO$_{2}$) enabling background-free detection and characterization of the O$_2$/CO$_2$ mixing ratio. In comparison to a Fourier analysis, our technique does not require femtosecond time re...

  6. 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...... months, a significant reduction in the mean choline signal was observed compared with the pretreatment (P=0.035) and 3-month scan (P=0.021). The reduction in the tumour choline/water signal paralleled tumour volume change and may reflect the therapeutic effect of temozolomide...

  7. Note: High sensitivity pulsed electron spin resonance spectroscopy with induction detection.

    Science.gov (United States)

    Twig, Ygal; Dikarov, Ekaterina; Hutchison, Wayne D; Blank, Aharon

    2011-07-01

    Commercial electron spin resonance spectroscopy and imaging systems make use of the so-called "induction" or "Faraday" detection, which is based on a radio frequency coil or a microwave resonator. The sensitivity of induction detection does not exceed ~3 × 10(8) spins/√Hz. Here we show that through the use of a new type of surface loop-gap microresonators (inner size of 20 μm), operating at cryogenic temperatures at a field of 0.5 T, one can improve upon this sensitivity barrier by more than 2 orders of magnitude and reach spin sensitivities of ~1.5 × 10(6) spins/√Hz or ~2.5 × 10(4) spins for 1 h.

  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. Carbon-deuterium rotational-echo double-resonance NMR spectroscopy of lyophilized aspartame formulations.

    Science.gov (United States)

    Luthra, Suman A; Utz, Marcel; Gorman, Eric M; Pikal, Michael J; Munson, Eric J; Lubach, Joseph W

    2012-01-01

    In this study, changes in the local conformation of aspartame were observed in annealed lyophilized glasses by monitoring changes in the distance between two labeled sites using C-(2)H rotational-echo double-resonance (REDOR) nuclear magnetic resonance (NMR) spectroscopy. Confirmation that the REDOR experiments were producing accurate distance measurement was ensured by measuring the (13)C-(15)N distance in glycine. The experiment was further verified by measuring the REDOR dephasing curve on (13)C-(2)H methionine. (13)C-(2)H REDOR dephasing curves were then measured on lyophilized aspartame-disaccharide formulations. In aspartame-sucrose formulation, the internuclear distances increased upon annealing, which correlated with decreased chemical reactivity. By contrast, annealing had only a minimal effect on the dephasing curve in aspartame-trehalose formulation. The results show that stability is a function of both mobility and local structure (conformation), even in a small molecule system such as lyophilized aspartame-sucrose.

  10. Resonance light scattering spectroscopy study of interaction between gold colloid and thiamazole and its analytical application

    Science.gov (United States)

    Liu, Xiaoling; Yuan, Hong; Pang, Daiwen; Cai, Ruxiu

    2004-01-01

    In this paper, we used resonance light scattering (RLS) spectroscopy to study the interaction between thiol-containing pharmaceutical-thiamazole and gold colloid. At pH 5.2, the resonance light scattering spectrum of gold nanoparticles has a maximum peak at 555 nm and the RLS intensity is enhanced by trace amount of thiamazole due to the interaction between thiamazole and gold colloid. The binding of colloidal gold to thiamazole results in ligand-induced aggregation of colloidal gold, which was characterized by RLS spectrum, ultraviolet-visible (UV-Vis) spectrum, and transmission electron microscopy (TEM). Based upon the study, we proposed a highly sensitive, gold colloid-based assay using RLS spectrum to detect pharmaceuticals for the first time. The mechanism of binding interaction between Au colloid and thiamazole was also discussed.

  11. 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

  12. Electron spin resonance spectroscopy for the study of nanomaterial-mediated generation of reactive oxygen species

    Directory of Open Access Journals (Sweden)

    Weiwei He

    2014-03-01

    Full Text Available Many of the biological applications and effects of nanomaterials are attributed to their ability to facilitate the generation of reactive oxygen species (ROS. Electron spin resonance (ESR spectroscopy is a direct and reliable method to identify and quantify free radicals in both chemical and biological environments. In this review, we discuss the use of ESR spectroscopy to study ROS generation mediated by nanomaterials, which have various applications in biological, chemical, and materials science. In addition to introducing the theory of ESR, we present some modifications of the method such as spin trapping and spin labeling, which ultimately aid in the detection of short-lived free radicals. The capability of metal nanoparticles in mediating ROS generation and the related mechanisms are also presented.

  13. Information flow and protein dynamics: the interplay between nuclear magnetic resonance spectroscopy and molecular dynamics simulations

    Science.gov (United States)

    Pastor, Nina; Amero, Carlos

    2015-01-01

    Proteins participate in information pathways in cells, both as links in the chain of signals, and as the ultimate effectors. Upon ligand binding, proteins undergo conformation and motion changes, which can be sensed by the following link in the chain of information. Nuclear magnetic resonance (NMR) spectroscopy and molecular dynamics (MD) simulations represent powerful tools for examining the time-dependent function of biological molecules. The recent advances in NMR and the availability of faster computers have opened the door to more detailed analyses of structure, dynamics, and interactions. Here we briefly describe the recent applications that allow NMR spectroscopy and MD simulations to offer unique insight into the basic motions that underlie information transfer within and between cells. PMID:25999971

  14. Information Flow and Protein Dynamics: the Interplay Between Nuclear Magnetic Resonance Spectroscopy and Molecular Dynamics Simulations

    Directory of Open Access Journals (Sweden)

    Nina ePastor

    2015-05-01

    Full Text Available Proteins participate in information pathways in cells, both as links in the chain of signals, and as the ultimate effectors. Upon ligand binding, proteins undergo conformation and motion changes, which can be sensed by the following link in the chain of information. Nuclear magnetic resonance (NMR spectroscopy and molecular dynamics (MD simulations represent powerful tools for examining the time-dependent function of biological molecules. The recent advances in NMR and the availability of faster computers have opened the door to more detailed analyses of structure, dynamics and interactions. Here we briefly describe the recent applications that allow NMR spectroscopy and MD simulations to offer unique insight into the basic motions that underlie information transfer within and between cells.

  15. Excitation and Imaging of Resonant Optical Modes of Au Triangular Nano-Antennas Using Cathodoluminescence Spectroscopy

    CERN Document Server

    Kumar, Anil; Mabon, James C; Chow, Edmond; Fang, Nicholas X

    2010-01-01

    Cathodoluminescence (CL) imaging spectroscopy is an important technique to understand resonant behavior of optical nanoantennas. We report high-resolution CL spectroscopy of triangular gold nanoantennas designed with near-vacuum effective index and very small metal-substrate interface. This design helped in addressing issues related to background luminescence and shifting of dipole modes beyond visible spectrum. Spatial and spectral investigations of various plasmonic modes are reported. Out-of-plane dipole modes excited with vertically illuminated electron beam showed high-contrast tip illumination in panchromatic imaging. By tilting the nanostructures during fabrication, in-plane dipole modes of antennas were excited. Finite-difference time-domain simulations for electron and optical excitations of different modes showed excellent agreement with experimental results. Our approach of efficiently exciting antenna modes by using low index substrates is confirmed both with experiments and numerical simulations....

  16. Application of electron paramagnetic resonance (EPR) spectroscopy and imaging in drug delivery research - chances and challenges.

    Science.gov (United States)

    Kempe, Sabine; Metz, Hendrik; Mäder, Karsten

    2010-01-01

    Electron Paramagnetic Resonance (EPR) spectroscopy is a powerful technique to study chemical species with unpaired electrons. Since its discovery in 1944, it has been widely used in a number of research fields such as physics, chemistry, biology and material and food science. This review is focused on its application in drug delivery research. EPR permits the direct measurement of microviscosity and micropolarity inside drug delivery systems (DDS), the detection of microacidity, phase transitions and the characterization of colloidal drug carriers. Additional information about the spatial distribution can be obtained by EPR imaging. The chances and also the challenges of in vitro and in vivo EPR spectroscopy and imaging in the field of drug delivery are discussed.

  17. Multidimensional resonant nonlinear spectroscopy with coherent broadband x-ray pulses

    Science.gov (United States)

    Bennett, Kochise; Zhang, Yu; Kowalewski, Markus; Hua, Weijie; Mukamel, Shaul

    2016-12-01

    New x-ray free electron laser (XFEL) and high harmonic generation (HHG) light sources are capable of generating short and intense pulses that make x-ray nonlinear spectroscopy possible. Multidimensional spectroscopic techniques, which have long been used in the nuclear magnetic resonance, infrared, and optical regimes to probe the electronic structure and nuclear dynamics of molecules by sequences of short pulses with variable delays, can thus be extended to the attosecond x-ray regime. This opens up the possibility of probing core-electronic structure and couplings, the real-time tracking of impulsively created valence-electronic wavepackets and electronic coherences, and monitoring ultrafast processes such as nonadiabatic electron-nuclear dynamics near conical-intersection crossings. We survey various possible types of multidimensional x-ray spectroscopy techniques and demonstrate the novel information they can provide about molecules.

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

    Science.gov (United States)

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

    2011-07-13

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

  19. Correlation spectroscopy in cold atoms: Light sideband resonances in electromagnetically-induced-transparency condition

    Science.gov (United States)

    Florez, H. M.; Kumar, A.; Theophilo, K.; Nussenzveig, P.; Martinelli, M.

    2016-07-01

    The correlation spectroscopy has been successfully employed in the measurement of the intrinsic linewidth of electromagnetically induced transparency (EIT) in time and frequency domain. We study the role of the sidebands of the intense fields in the measured spectra, analyzing the information that can be recovered working with different analysis frequencies. In this case, the nonzero one-photon detuning appears as a necessary condition for spectrally resolving the sideband resonances in the correlation coefficient. Our experimental findings are supported by the perturbative model defined in the frequency domain.

  20. Correlation spectroscopy in cold atoms: light sidebands resonances in electromagnetically induced transparency condition

    CERN Document Server

    Florez, H M; Theophilo, K; Nussenzveig, P; Martinelli, M

    2015-01-01

    The correlation spectroscopy has been successfully employed in the measurement of the intrinsic linewidth of electromagnetically induced transparency (EIT) in time and frequency domain. We study the role of the sidebands of the intense fields in the measured spectra, analyzing the information that can be recovered working with different analysis frequencies. In this case, the non-zero one-photon detuning appears as a necessary condition for spectrally resolving the sideband resonances in the correlation coefficient. Our experimental findings are supported by the perturbative model defined in the frequency domain.

  1. Al-doped MgB2 materials studied using electron paramagnetic resonance and Raman spectroscopy

    Science.gov (United States)

    Bateni, Ali; Erdem, Emre; Repp, Sergej; Weber, Stefan; Somer, Mehmet

    2016-05-01

    Undoped and aluminum (Al) doped magnesium diboride (MgB2) samples were synthesized using a high-temperature solid-state synthesis method. The microscopic defect structures of Al-doped MgB2 samples were systematically investigated using X-ray powder diffraction, Raman spectroscopy, and electron paramagnetic resonance. It was found that Mg-vacancies are responsible for defect-induced peculiarities in MgB2. Above a certain level of Al doping, enhanced conductive properties of MgB2 disappear due to filling of vacancies or trapping of Al in Mg-related vacancy sites.

  2. Characterization of gold nanoparticle bioconjugation by resonance light scattering correlation spectroscopy

    Institute of Scientific and Technical Information of China (English)

    Xin Qiu; Li Chuan Tang; Chao Qing Dong; Ji Cun Ren

    2010-01-01

    Gold nanoparticles(GNPs)have been widely used as probes and nanomaterials in certain biological and biomedical fields thanks to its special physical and chemical properties.However,it is still difficult to characterize GNPs-bioconjugates in solution,which has greatly limited further bioapplications of GNPs.In this study,we reported a single particle method for characterizing GNPsbiomolecules in solution using resonance light scattering correlation spectroscopy(RLSCS).The interaction of GNPs with bovine serum albumin(BSA)and thiol-modified oligonucletides were investigated.

  3. Ordering of PCDTBT revealed by time-resolved electron paramagnetic resonance spectroscopy of its triplet excitons.

    Science.gov (United States)

    Biskup, Till; Sommer, Michael; Rein, Stephan; Meyer, Deborah L; Kohlstädt, Markus; Würfel, Uli; Weber, Stefan

    2015-06-22

    Time-resolved electron paramagnetic resonance (TREPR) spectroscopy is shown to be a powerful tool to characterize triplet excitons of conjugated polymers. The resulting spectra are highly sensitive to the orientation of the molecule. In thin films cast on PET film, the molecules' orientation with respect to the surface plane can be determined, providing access to sample morphology on a microscopic scale. Surprisingly, the conjugated polymer investigated here, a promising material for organic photovoltaics, exhibits ordering even in bulk samples. Orientation effects may significantly influence the efficiency of solar cells, thus rendering proper control of sample morphology highly important.

  4. High-overtone Bulk-Acoustic Resonator gravimetric sensitivity: towards wideband acoustic spectroscopy

    CERN Document Server

    Rabus, D; Ballandras, S; Baron, T; Lebrasseur, E; Carry, E

    2015-01-01

    In the context of direct detection sensors with compact dimensions, we investigate the gravimetric sensitivity of High-overtone Bulk Acoustic Resonators, through modeling of their acoustic characteristics and experiment. The high frequency characterizing such devices is expected to induce a significant effect when the acoustic field boundary conditions are modified by a thin adlayer. Furthermore, the multimode spectral characteristics is considered for wideband acoustic spectroscopy of the adlayer, once the gravimetric sensitivity dependence of the various overtones is established. Finally, means of improving the gravimetric sensitivity by confining the acoustic field in a low acoustic-impedance layer is theoretically established.

  5. 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

  6. 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.

  7. Resonant femtosecond stimulated Raman spectroscopy with an intense actinic pump pulse: Application to conical intersections

    Science.gov (United States)

    Rao, B. Jayachander; Gelin, Maxim F.; Domcke, Wolfgang

    2017-02-01

    We theoretically investigate the feasibility of characterizing conical intersections with time-resolved resonant femtosecond stimulated Raman spectroscopy (FSRS) using an intense actinic pump pulse. We perform nonperturbative numerical simulations of FSRS signals for a three-electronic-state two-vibrational-mode model, which is inspired by the S 2 ( π π * )- S 1 ( n π * ) conical intersection in pyrazine. Our results show that moderately strong actinic pulses increase the intensity of vibrational fingerprint lines in FSRS transients. They facilitate the extraction of useful spectroscopic information by enhancing peaks revealing the coupling and tuning modes of the conical intersection.

  8. Selective excitation of molecular mode in a mixture by femtosecond resonance-enhanced coherent anti-Stokes Raman scattering spectroscopy

    Institute of Scientific and Technical Information of China (English)

    He Ping; Li Si-Ning; Fan Rong-Wei; Li Xiao-Hui; Xia Yuan-Qin; Yu Xin; Chen De-Ying

    2012-01-01

    Femtosecond time-resolved coherent anti-Stokes Raman scattering (CARS) spectroscopy is used to investigate gaseous molecular dynamics.Due to the spectrally broad laser pulses,usually poorly resolved spectra result from this broad spectroscopy.However,it can be demonstrated that by the electronic resonance enhancement optimization control a selective excitation of specific vibrational mode is possible.Using an electronically resonance-enhanced effect,iodine molecule specific CARS spectroscopy can be obtained from a mixture of iodine-air at room temperature and a pressure of 1 atm (corresponding to a saturation iodine vapour as low as about 35 Pa).The dynamics on either the electronically excited state or the ground state of iodine molecules obtained is consistent with previous studies (vacuum,heated and pure iodine) in the femtosecond time resolved CARS spectroscopy,showing that an effective method of suppressing the non-resonant CARS background and other interferences is demonstrated.

  9. Studying Kittel-like modes in a 3D YIG disk using Torque-mixing Magnetic Resonance Spectroscopy

    Science.gov (United States)

    Fani Sani, Fatemeh; Losby, Joseph; Grandmont, Dylan; Diao, Zhu; Belov, Miro; Burgess, Jacob; Compton, Shawn; Hiebert, Wayne; Vick, Doug; Mohammad, Kaveh; Salimi, Elham; Bridges, Gregory; Thomson, Douglas; Freeman, Mark

    We report a study of ferrimagnetic resonance in a mesoscopic, single-crystalline YIG disk using torque-mixing magnetic resonance spectroscopy (TMRS). The Kittel model for magnetic resonance is a touchstone in measuring fundamental magnetic properties for magnetic films, which does not significantly depend on the film size. In 3D structures, ladders of confined resonance modes are observed, and these can exhibit the non-monotonic evolution of frequency with field familiar from Kittel modes. TMRS is a tool uniquely suited for observing this physics in individual 3D structures, on account of its combination of high sensitivity and broadband capability coupled with fine frequency resolution.

  10. Multipitched Diffraction Gratings for Surface Plasmon Resonance-Enhanced Infrared Reflection Absorption Spectroscopy.

    Science.gov (United States)

    Petefish, Joseph W; Hillier, Andrew C

    2015-11-03

    We demonstrate the application of metal-coated diffraction gratings possessing multiple simultaneous pitch values for surface enhanced infrared absorption (SEIRA) spectroscopy. SEIRA increases the magnitude of vibrational signals in infrared measurements by one of several mechanisms, most frequently involving the enhanced electric field associated with surface plasmon resonance (SPR). While the majority of SEIRA applications to date have employed nanoparticle-based plasmonic systems, recent advances have shown how various metals and structures lead to similar signal enhancement. Recently, diffraction grating couplers have been demonstrated as a highly tunable platform for SEIRA. Indeed, gratings are an experimentally advantageous platform due to the inherently tunable nature of surface plasmon excitation at these surfaces since both the grating pitch and incident angle can be used to modify the spectral location of the plasmon resonance. In this work, we use laser interference lithography (LIL) to fabricate gratings possessing multiple pitch values by subjecting photoresist-coated glass slides to repetitive exposures at varying orientations. After metal coating, these gratings produced multiple, simultaneous plasmon peaks associated with the multipitched surface, as identified by infrared reflectance measurements. These plasmon peaks could then be coupled to vibrational modes in thin films to provide localized enhancement of infrared signals. We demonstrate the flexibility and tunability of this platform for signal enhancement. It is anticipated that, with further refinement, this approach might be used as a general platform for broadband enhancement of infrared spectroscopy.

  11. Laser-rf double-resonance spectroscopy in a storage ring

    Science.gov (United States)

    Kristensen, M.; Hangst, J. S.; Jessen, P. S.; Nielsen, J. S.; Poulsen, O.; Shi, P.

    1992-10-01

    Laser-rf double-resonance spectroscopy of the hyperfine transition between F''=0 and F'=1 in the metastable 3S1 state of 6Li+ was performed in 100-keV beam in the storage ring ASTRID. High efficiency of optical pumping was demonstrated for complex pumping schemes. A broadband (dc-6 GHz) rf device was designed and used for rf spectroscopy in the storage ring. The possibility of obtaining coherent rf signals (Ramsey fringes) from successive interactions with the same field was investigated. Important limitations for the coherences due to magnetic-field inhomogeneities were observed. These led to randomization of the atomic polarization during only one turn in the storage ring and completely prevented observation of Ramsey fringes. This situation is different from the case of fundamental particles in a storage ring, where the polarization may be preserved for many round-trips. Limits were put on the demands to beam quality, beam positioning, and magnetic-field quality to overcome the problem. The effects of the rf device on the external degrees of freedom of the ion beam were investigated. Its small aperture substantially reduced the beam lifetime, and at very low rf frequencies the electric field in the rf device was able to excite external transverse resonances in the beam.

  12. Non-destructive testing of ceramic balls using high frequency ultrasonic resonance spectroscopy.

    Science.gov (United States)

    Petit, S; Duquennoy, M; Ouaftouh, M; Deneuville, F; Ourak, M; Desvaux, S

    2005-12-01

    Although ceramic balls are used more and more for bearings in the aerospace and space industries, defects in this type of ceramic material could be dangerous, particularly if such defects are located close to the surface. In this paper, we propose a non-destructive testing method for silicon nitride balls, based on ultrasonic resonance spectroscopy. Through the theoretical study of their elastic vibrations, it is possible to characterize the balls using a vibration mode that is similar to surface wave propagation. The proposed methodology can both excite spheroidal vibrations in the ceramic balls and detect such vibrations over a large frequency range. Studying their resonance spectrums allows the balls' elastic parameters be characterized. Ours is an original method that can quickly estimate the velocity of surface waves using high frequency resonances, which permits surface and sub-surface areas to be tested specifically. Two applications are described in this paper. Both use velocity measurements to achieve their different goals, the first to differentiate between flawless balls from different manufacturing processes, and the second to detect small defects, such as cracks. Our method is rapid and permits the entire ceramic ball to be tested in an industrial context.

  13. Optimized spectral analysis in magnetic resonance spectroscopy for early tumor diagnostics

    Science.gov (United States)

    Belkić, Karen; Belkić, Dževad

    2014-12-01

    Molecular imaging through magnetic resonance spectroscopy (MRS) can provide information about key metabolites. Conventional applications of MRS are hampered by data analysis via the fast Fourier transform (FFT). Most MRS studies for cancer detection have relied upon estimations of a mere handful or even a single composite metabolite, e.g. total choline. These have yielded incremental improvements in diagnostic accuracy. In vitro studies reveal richer metabolic information for identifying cancer, particularly in closely-overlapping resonances. Among these are phosphocholine, a marker of malignant transformation. The FFT cannot assess these congested spectral components. This can be done by the fast Pade transform (FPT), an advanced, high-resolution, quantification-equipped method, applied to MRS time signals as encoded from patients with breast cancers and other cancers, with benign pathology and with normal tissue, as illustrated herein for the latter. With realistic noise levels, the FPT accurately computes the metabolite concentrations, including phosphocholine, which completely underlies phosphoethanolamine. In sharp contrast, the FFT produces a rough envelope spectrum with only a few shortened, broadened peaks, and key metabolites altogether absent. The FPT clearly separates true metabolites from spurious resonances. The efficiency and high resolution of the FPT translates into shortened examination time of the patient. These capabilities strongly suggest that by applying the FPT to time signals encoded in vivo from breast cancer and other malignancies, MRS will fulfill its potential to become a clinically- reliable, cost-effective method for early cancer detection.

  14. Surface plasmon resonance spectroscopy of single bowtie nano-antennas using a differential reflectivity method.

    Science.gov (United States)

    Kaniber, M; Schraml, K; Regler, A; Bartl, J; Glashagen, G; Flassig, F; Wierzbowski, J; Finley, J J

    2016-03-23

    We report on the structural and optical properties of individual bowtie nanoantennas both on glass and semiconducting GaAs substrates. The antennas on glass (GaAs) are shown to be of excellent quality and high uniformity reflected by narrow size distributions with standard deviations for the triangle and gap size of = 4.5 nm = 2.6 nm and = 5.4 nm = 3.8 nm, respectively. The corresponding optical properties of individual nanoantennas studied by differential reflection spectroscopy show a strong reduction of the localised surface plasmon polariton resonance linewidth from 0.21 eV to 0.07 eV upon reducing the antenna size from 150 nm to 100 nm. This is attributed to the absence of inhomogeneous broadening as compared to optical measurements on nanoantenna ensembles. The inter-particle coupling of an individual bowtie nanoantenna, which gives rise to strongly localised and enhanced electromagnetic hotspots, is demonstrated using polarization-resolved spectroscopy, yielding a large degree of linear polarization of ρmax ~ 80%. The combination of highly reproducible nanofabrication and fast, non-destructive and non-contaminating optical spectroscopy paves the route towards future semiconductor-based nano-plasmonic circuits, consisting of multiple photonic and plasmonic entities.

  15. Numerical and experimental investigation of a low-frequency measurement technique: differential acoustic resonance spectroscopy

    Science.gov (United States)

    Yin, Hanjun; Zhao, Jianguo; Tang, Genyang; Ma, Xiaoyi; Wang, Shangxu

    2016-06-01

    Differential acoustic resonance spectroscopy (DARS) has been developed to determine the elastic properties of saturated rocks within the kHz frequency range. This laboratory technique is based on considerations from perturbation theory, wherein the resonance frequencies of the resonant cavity with and without a perturbation sample are used to estimate the acoustic properties of the test sample. In order to better understand the operating mechanism of DARS and therefore optimize the procedure, it is important to develop an accurate and efficient numerical model. Accordingly, this study presents a new multiphysics model by coupling together considerations from acoustics, solid mechanics, and electrostatics. The numerical results reveal that the newly developed model can successfully simulate the acoustic pressure field at different resonance modes, and that it can accurately reflect the measurement process. Based on the understanding of the DARS system afforded by the numerical simulation, we refine the system configuration by utilizing cavities of different lengths and appropriate radii to broaden the frequency bandwidth and ensure testing accuracy. Four synthetic samples are measured to test the performance of the optimized DARS system, in conjunction with ultrasonic and static measurements. For nonporous samples, the estimated bulk moduli are shown to be independent of the different measurement methods (i.e. DARS or ultrasonic techniques). In contrast, for sealed porous samples, the differences in bulk moduli between the low- and high-frequency techniques can be clearly observed; this discrepancy is attributed to frequency dispersion. In summary, the optimized DARS system with an extended frequency range of 500-2000 Hz demonstrates considerable utility in investigating the frequency dependence of the acoustic properties of reservoir rocks.

  16. Forward models for extending the mechanical damage evaluation capability of resonant ultrasound spectroscopy.

    Science.gov (United States)

    Goodlet, B R; Torbet, C J; Biedermann, E J; Jauriqui, L M; Aldrin, J C; Pollock, T M

    2017-02-08

    Finite element (FE) modeling has been coupled with resonant ultrasound spectroscopy (RUS) for nondestructive evaluation (NDE) of high temperature damage induced by mechanical loading. Forward FE models predict mode-specific changes in resonance frequencies (ΔfR), inform RUS measurements of mode-type, and identify diagnostic resonance modes sensitive to individual or multiple concurrent damage mechanisms. The magnitude of modeled ΔfR correlate very well with the magnitude of measured ΔfR from RUS, affording quantitative assessments of damage. This approach was employed to study creep damage in a polycrystalline Ni-based superalloy (Mar-M247) at 950°C. After iterative applications of creep strains up to 8.8%, RUS measurements recorded ΔfR that correspond to the accumulation of plastic deformation and cracks in the gauge section of a cylindrical dog-bone specimen. Of the first 50 resonance modes that occur, ranging from 3 to 220kHz, modes classified as longitudinal bending were most sensitive to creep damage while transverse bending modes were found to be largely unaffected. Measure to model comparisons of ΔfR show that the deformation experienced by the specimen during creep, specifically uniform elongation of the gauge section, is responsible for a majority of the measured ΔfR until at least 6.1% creep strain. After 8.8% strain considerable surface cracking along the gauge section of the dog-bone was observed, for which FE models indicate low-frequency longitudinal bending modes are significantly affected. Key differences between historical implementations of RUS for NDE and the FE model-based framework developed herein are discussed, with attention to general implementation of a FE model-based framework for NDE of damage.

  17. Individual variation in macronutrient regulation measured by proton magnetic resonance spectroscopy of human plasma.

    Science.gov (United States)

    Park, Youngja; Kim, Seoung Bum; Wang, Bing; Blanco, Roberto A; Le, Ngoc-Anh; Wu, Shaoxiong; Accardi, Carolyn J; Alexander, R Wayne; Ziegler, Thomas R; Jones, Dean P

    2009-07-01

    Proton nuclear magnetic resonance ((1)H-NMR) spectroscopy of plasma provides a global metabolic profiling method that shows promise for clinical diagnostics. However, cross-sectional studies are complicated by a lack of understanding of intraindividual variation, and this limits experimental design and interpretation of data. The present study determined the diurnal variation detected by (1)H NMR spectroscopy of human plasma. Data reduction methods revealed three time-of-day metabolic patterns, which were associated with morning, afternoon, and night. Major discriminatory regions for these time-of-day patterns included the various kinds of lipid signals (-CH(2)- and -CH(2)OCOR), and the region between 3 and 4 ppm heavily overlapped with amino acids that had alpha-CH and alpha-CH(2). The phasing and duration of time-of-day patterns were variable among individuals, apparently because of individual difference in food processing/digestion and absorption and clearance of macronutrient energy sources (fat, protein, carbohydrate). The times of day that were most consistent among individuals, and therefore most useful for cross-sectional studies, were fasting morning (0830-0930), postprandial afternoon (1430-1630), and nighttime samples (0430-0530). Importantly, the integrated picture of metabolism provided by (1)H-NMR spectroscopy of plasma suggests that this approach is suitable to study complex regulatory processes, including eating patterns/eating disorders, upper gastrointestinal functions (gastric emptying, pancreatic, biliary functions), and absorption/clearance of macronutrients. Hence, (1)H-NMR spectroscopy of plasma could provide a global metabolic tolerance test to assess complex processes involved in disease, including eating disorders and the range of physiological processes causing dysregulation of energy homeostasis.

  18. 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

  19. 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.

  20. 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.

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

    Directory of Open Access Journals (Sweden)

    Margaretha eDramsdahl

    2011-11-01

    Full Text Available BackgroundImpaired 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 (ACC in adults with ADHD and healthy controls. MethodsTwenty-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. ResultsThe ADHD group showed a significant reduction of Glu/Cre in the left midfrontal region compared to the controls. ConclusionsThe 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, resulting in problems with cognitive control.

  2. 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

    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......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...

  3. 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.

  4. 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

    2016-01-01

    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...... on copper ion exchanged into a CHA zeolite with Si/Al = 14 ± 1 to obtain Cu/Al = 0.46 ± 0.02. The results shed light on the identity of different copper species present after activation in air. Since the EPR signal is quantifiable, the content of the different EPR active species has been elucidated and Cu2...... information about the reactivity and the quantity of some of the otherwise EPR silent species. In this way the [Cu–OH]+ species in copper substituted low-Al zeolites has been indirectly observed and quantified. EPR active Cu2+ species have been followed under reduction and oxidation with gas mixtures relevant...

  5. Magnetic resonance spectroscopy of an atomically thin material using a single-spin qubit

    Science.gov (United States)

    Lovchinsky, I.; Sanchez-Yamagishi, J. D.; Urbach, E. K.; Choi, S.; Fang, S.; Andersen, T. I.; Watanabe, K.; Taniguchi, T.; Bylinskii, A.; Kaxiras, E.; Kim, P.; Park, H.; Lukin, M. D.

    2017-02-01

    Two-dimensional (2D) materials offer a promising platform for exploring condensed matter phenomena and developing technological applications. However, the reduction of material dimensions to the atomic scale poses a challenge for traditional measurement and interfacing techniques that typically couple to macroscopic observables. We demonstrate a method for probing the properties of 2D materials via nanometer-scale nuclear quadrupole resonance (NQR) spectroscopy using individual atomlike impurities in diamond. Coherent manipulation of shallow nitrogen-vacancy (NV) color centers enables the probing of nanoscale ensembles down to approximately 30 nuclear spins in atomically thin hexagonal boron nitride (h-BN). The characterization of low-dimensional nanoscale materials could enable the development of new quantum hybrid systems, combining atomlike systems coherently coupled with individual atoms in 2D materials.

  6. Free radical scavenging activity of erdosteine metabolite I investigated by electron paramagnetic resonance spectroscopy.

    Science.gov (United States)

    Braga, Pier Carlo; Culici, Maria; Dal Sasso, Monica; Falchi, Mario; Spallino, Alessandra

    2010-01-01

    The aim of this study was to explore the antiradical activity of Met I (an active metabolite of erdosteine) containing a pharmacologically active sulphydryl group, by means of electron paramagnetic resonance (EPR) spectroscopy which has not previously been used to characterize the antiradical activity of Met I. The effects of concentrations of 20, 10, 5, 2.5, 1.25 and 0.625 microg/ml of Met I were tested against: (a) the Fenton reaction model system with EPR detection of HO.; (b) the KO2-crown ether system with EPR detection of O2-.; (c) the EPR assay based on the reduction of the Tempol radical, and (d) the EPR assay based on the reduction of Fremy's salt radical. Our findings show that the intensity of 4 different free radicals was significantly reduced in the presence of Met I, thus indicating the presence of a termination reaction between the free radicals and Met I.

  7. 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.

  8. 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.

  9. In vivo neurochemistry with emission tomography and magnetic resonance spectroscopy: clinical applications.

    Science.gov (United States)

    Del Sole, Angelo; Gambini, Anna; Falini, Andrea; Lecchi, Michela; Lucignani, Giovanni

    2002-10-01

    The assessment of neurochemical processes in vivo has received much attention in the past decade as techniques such as positron or single photon emission tomography (PET and SPET), and magnetic resonance spectroscopy (MRS) have become more available. With PET and SPET, basic processes, such as blood flow and oxygen or glucose metabolism, can be regionally assessed, along with more specific functions such as the production, release, and reuptake of neurotransmitters and their occupancy of specific receptors. At the same time, MRS can reveal changes in concentration of several hydrogenate compounds in the brain. All these methods have been extensively applied for research in neurology, and some applications have reached the clinical level, namely for the study of degenerative diseases, motor-neuron diseases, movement disorders, cerebrovascular diseases, and epilepsy. This article focuses on the most relevant information that can be obtained with these complementary techniques to help clinicians in the assessment of neurological diseases.

  10. In vivo neurochemistry with emission tomography and magnetic resonance spectroscopy: clinical applications

    Energy Technology Data Exchange (ETDEWEB)

    Sole, Angelo Del [Azienda Ospedaliera San Paolo e Universita di Milano, 20142 Milan (Italy); Gambini, Anna; Falini, Andrea [IRCCS H San Raffaele e Universita Vita e Salute, 20132 Milan (Italy); Lecchi, Michela [Azienda Ospedaliera L. Sacco e Universita di Milano, 20157 Milan (Italy); Lucignani, Giovanni [Azienda Ospedaliera L. Sacco e Universita di Milano, 20157 Milan (Italy); Universita di Milano, Istituto di Scienze Radiologiche, Cattedra di Medicina Nucleare c/o Ospedale L. Sacco, Via G.B. Grassi, 74, 20157 Milan (Italy)

    2002-10-01

    The assessment of neurochemical processes in vivo has received much attention in the past decade as techniques such as positron or single photon emission tomography (PET and SPET), and magnetic resonance spectroscopy (MRS) have become more available. With PET and SPET, basic processes, such as blood flow and oxygen or glucose metabolism, can be regionally assessed, along with more specific functions such as the production, release, and reuptake of neurotransmitters and their occupancy of specific receptors. At the same time, MRS can reveal changes in concentration of several hydrogenate compounds in the brain. All these methods have been extensively applied for research in neurology, and some applications have reached the clinical level, namely for the study of degenerative diseases, motor-neuron diseases, movement disorders, cerebrovascular diseases, and epilepsy. This article focuses on the most relevant information that can be obtained with these complementary techniques to help clinicians in the assessment of neurological diseases. (orig.)

  11. 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.

  12. In vivo proton magnetic resonance spectroscopy in a known case of intracranial hydatid cyst

    Directory of Open Access Journals (Sweden)

    Chand K

    2005-01-01

    Full Text Available We are presenting magnetic resonance spectroscopy (MRS findings of a known case of hydatid cyst operated twice in the past. A 22-years-old male patient had presented with recurrent symptoms of generalized seizures and raised intracranial tension. MRI with MRS of the lesion was performed that showed a recurrent loculated cystic lesion in right parieto-occipital lobe. MRS through the lesion was performed using repetition time (TR of 1500 ms and time to echo (TE of 135 ms using 2 x 2 x 2 cm voxel, from the margin of the lesion. MRS showed mildly elevated choline (Cho, depressed creatine (Cr and N-acetyl aspartate (NAA, a large peak of lactate, pyruvate and acetate peaks.

  13. Determination of the first ionization potential of actinides by resonance ionization mass spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Koehler, S. [Institut fuer Kernchemie Universitaet Mainz, Mainz (Germany); Albus, F. [Institu fuer Physik, Universitaet Mainz, Mainz (Germany); Dibenberger, R.; Erdmann, N.; Funk, H. [Institut fuer Kernchemiess Universitaet Mainz, Mainz (Germany); Hasse, H. [Institut fuer Physik, Universitaet Mainz, Mainz (Germany); Herrmann, G. [Institut fuer Kernchemiess Universitaet Mainz, Mainz (Germany); Huber, G.; Kluge, H.; Nunnemann, M.; Passler, G. [Institut fuer Physik, Universitaet Mainz, Mainz (Germany); Rao, P.M. [Bhabha Atomic Research Centre Bombay (India); Riegel, J.; Trautmann, N. [Institut fuer Kernchemie Universitaet Mainz, Mainz (Germany); Urban, F. [Institut fuer Physik, Universitaet Mainz, Mainz (Germany)

    1995-04-01

    Resonance ionization mass spectroscopy (RIMS) is used for the precise determination of the first ionization potential of transuranium elements. The first ionization potentials (IP) of americium and curium have been measured for the first time to IP{sub {ital Am}}=5.9738(2) and IP{sub {ital Cm}}=5.9913(8) eV, respectively, using only 10{sup 12} atoms of {sup 243}Am and {sup 248}Cm. The same technique was applied to thorium, neptunium, and plutonium yielding IP{sub T{sub H}}=6.3067(2), IP{sub N{sub P}}=6.2655(2), and IP{sub {ital Pu}}=6.0257(8) eV. The good agreement of our results with the literature data proves the precision of the method which was additionally confirmed by the analysis of Rydberg seris of americium measured by RIMS. {copyright}American Institute of Physics 1995

  14. Proton magnetic resonance spectroscopy of a patient with Gerstmann-Straussler-Scheinker disease

    Energy Technology Data Exchange (ETDEWEB)

    Konaka, K.; Kaido, M.; Okuda, Y.; Aoike, F.; Abe, K.; Yanagihara, T. [Osaka Univ. Graduate School of Medicine (Japan). Dept. of Neurology; Kitamoto, T. [Tohoku Univ. Graduate School of Medicine (Japan). Dept. of Neurological Science

    2000-09-01

    A 23-year-old woman with Gerstmann-Straussler-Scheinker disease (GSS) was investigated by {sup 1}H-magnetic resonance spectroscopy ({sup 1}H-MRS). She developed gait ataxic at 22 years. The diagnosis was confirmed by DNA analysis showing a proline-to-leucine point mutation at codon 102 of the prion protein. On {sup 1}H-MRS, she showed a remarkable reduction of the N-acetylaspartate/creatine ratio in the frontal lobe, cerebellar hemisphere and vermis and putamen. MRI revealed mild atrophy of the cerebellar hemispheres and vermis and cerebral cortex, but single-photon emission computed tomography (SPECT) with {sup 99m}HMPAO showed normal perfusion in the cerebellum. The imaging studies suggest that MRS might be superior to MRI or SPECT for detection of early neuronal degeneration. (orig.)

  15. Quantification of brain metabolites in amyotrophic lateral sclerosis by localized proton magnetic resonance spectroscopy

    DEFF Research Database (Denmark)

    Gredal, O; Rosenbaum, S; Topp, S;

    1997-01-01

    We performed proton magnetic resonance spectroscopy (1H-MRS) in patients with motor neuron disease (MND) to determine the absolute in vivo concentrations in the brain of the metabolites N-acetyl aspartate (NAA), choline (Cho), and creatine (Cr/PCr). We examined the spectra acquired from a 20 x 20 x...... with both upper and lower motor neuron signs had a significantly decreased concentration of NAA (9.13 +/- 0.28 mM, mean +/- SEM) in the primary motor cortex when compared with healthy controls (10.03 +/- 0.22 mM). In conclusion, the slightly decreased concentration of NAA in the primary motor cortex from...... 20-mm3 voxel placed in the motor cortex and in the cerebellum from seven patients with clinically probable or definite amyotrophic lateral sclerosis (ALS) according to the El Escorial criteria, from three patients with suspected ALS (progressive muscular atrophy), and from eight normal control...

  16. Combining elastic and resonant inelastic optical spectroscopies for multiscale probing of embedded nanoparticle architectures

    Science.gov (United States)

    Farcau, Cosmin; Bonafos, Caroline; Benzo, Patrizio; Benassayag, Gerard; Carles, Robert

    2010-11-01

    Composite materials consisting of metal nanoparticles (NPs) embedded in a dielectric matrix have a great potential for photonic and plasmonic applications. A set of expensive, time-consuming, and destructive methods (like electron microscopy, electron energy loss, or secondary ion mass spectroscopy) are extensively being used for the structural characterization of such buried NP assemblies. Here, we show the power of combining complementary, noninvasive optical techniques to characterize planar arrays of Ag NPs embedded in a silica film. We use UV-Vis optical reflectivity and resonant Brillouin-Raman scattering, sustained by simulations, to show the sensitivity of these methods to the presence, density, size distribution, and spatial localization of NPs. The accuracy of the results is validated by transmission electron microscopy investigations. Finally the method is applied to obtain images of embedded plasmonic structures from reflectivity and Raman scanning microscopy.

  17. 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.)

  18. Molecularly imprinted polymers for highly sensitive detection of morphine using surface plasmon resonance spectroscopy

    Institute of Scientific and Technical Information of China (English)

    Hong Xia Hao; Hong Zhou; Jing Chang; Jun Zhu; Tian Xin Wei

    2011-01-01

    Molecular imprinting technology is applied in surface plasmon resonance spectroscopy for highly sensitive and selective detection of morphine (MO). As SPR-based sensor of MO, the preparation of molecular imprinted polymer is as follows: methacrylic acids (MAA), ethylene glycol dimethacrylate (EGDMA), azodiisobutyronitrile (AIBN) were used as functional monomer, cross-linker and initiator, respectively. The experiment results showed that morphine imprinted polymer had the performance of high sensitivity and specificity, i.e. the relative signal of SPR response was proportional to the concentration of morphine in acetonitrile in the range of 10-9 mol/L to 10-6mol/L (1 ppb-1 ppm) with LOD of 10-10mol/L, and MO was distinguished from its analogs, such as codeine.

  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. 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.

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

    Science.gov (United States)

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

    2013-01-01

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

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

    Science.gov (United States)

    Gambarota, Giulio

    2016-09-03

    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.

  3. Resonant two-photon ionization spectroscopy of Al atoms and dimers solvated in helium nanodroplets

    Energy Technology Data Exchange (ETDEWEB)

    Krasnokutski, Serge A.; Huisken, Friedrich [Laboratory Astrophysics Group of the Max Planck Institute for Astronomy at the Friedrich Schiller University Jena, Institute of Solid State Physics, Helmholtzweg 3, D-07743 Jena (Germany)

    2015-02-28

    Resonant two-photon ionization (R2PI) spectroscopy has been applied to investigate the solvation of Al atoms in helium droplets. The R2PI spectra reveal vibrational progressions that can be attributed to Al–He{sub n} vibrations. It is found that small helium droplets have very little chance to pick up an aluminum atom after collision. However, the pick-up probability increases with the size of the helium droplets. The absorption band that is measured by monitoring the ions on the mass of the Al dimer is found to be very little shifted with respect to the Al monomer band (∼400 cm{sup −1}). However, using the same laser wavelength, we were unable to detect any Al{sub n} photoion with n larger than two.

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

    Science.gov (United States)

    Blanchard, John Woodland

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

  5. Structural characterization of titania by X-ray diffraction, photoacoustic, Raman spectroscopy and electron paramagnetic resonance spectroscopy.

    Science.gov (United States)

    Kadam, R M; Rajeswari, B; Sengupta, Arijit; Achary, S N; Kshirsagar, R J; Natarajan, V

    2015-02-25

    A titania mineral (obtained from East coast, Orissa, India) was investigated by X-ray diffraction (XRD), photoacoustic spectroscopy (PAS), Raman and Electron Paramagnetic Resonance (EPR) studies. XRD studies indicated the presence of rutile (91%) and anatase (9%) phases in the mineral. Raman investigation supported this information. Both rutile and anatase phases have tetragonal structure (rutile: space group P4(2)/mnm, a=4.5946(1) Å, c=2.9597(1) Å, V=62.48(1) (Å)(3), Z=2; anatase: space group I4(1)/amd, 3.7848(2) Å, 9.5098(11) Å, V=136.22(2) (Å)(3), Z=4). The deconvoluted PAS spectrum showed nine peaks around 335, 370, 415,485, 555, 605, 659, 690,730 and 785 nm and according to the ligand field theory, these peaks were attributed to the presence of V(4+), Cr(3+), Mn(4+) and Fe(3+) species. EPR studies revealed the presence of transition metal ions V(4+)(d(1)), Cr(3+)(d(3)), Mn(4+)(d(3)) and Fe(3+)(d(5)) at Ti(4+) sites. The EPR spectra are characterized by very large crystal filed splitting (D term) and orthorhombic distortion term (E term) for multiple electron system (s>1) suggesting that the transition metal ions substitute the Ti(4+) in the lattice which is situated in distorted octahedral coordination of oxygen. The possible reasons for observation of unusually large D and E term in the EPR spectra of transition metal ions (S=3/2 and 5/2) are discussed.

  6. Fano resonance and the hidden order in URu2 Si 2 probed by quasiparticle scattering spectroscopy*

    Science.gov (United States)

    Park, W. K.; Greene, L. H.; Bauer, E. D.; Tobash, P. H.; Ronning, F.; Lu, X.; Sarrao, J. L.; Thompson, J. D.

    2011-03-01

    The nature of the hidden order transition occurring at 17.5 K in URu 2 Si 2 remains puzzling despite intensive investigations over the past two and half decades. Recent experimental and theoretical developments render it a timely subject to probe the hidden order state using quasiparticle tunneling and scattering techniques. We report on the Fano resonance in pure and Rh-doped URu 2 Si 2 single crystals using point-contact spectroscopy. The conductance spectra reproducibly reveal asymmetric double peak structures slightly off-centered around zero bias with the two peaks merging well above the hidden order transition temperature. An analysis using the Fano resonance model in a Kondo lattice [1] shows that the conductance peaks arise from the hybridization gap opening. Our estimated gap size agrees well with those reported from other measurements. We will present experimental results over a wide parameter space including temperature and doping dependences and discuss their underlying physics. M. Maltseva, M. Dzero, and P. Coleman, Phys. Rev. Lett. 103, 206402 (2009). * The work at UIUC is supported by the U.S. DOE under Award Nos. DE-FG02-07ER46453 and DE-AC02-98CH10886, and the work at LANL is carried out under the auspices of the U.S. DOE, Office of Science.

  7. Current and future applications of magnetic resonance imaging and spectroscopy of the brain in hepatic encephalopathy

    Institute of Scientific and Technical Information of China (English)

    VP Bob Grover; M Alex Dresner; Daniel M Forton; Serena Counsell; David J Larkman; Nayna Patel; Howard C Thomas; Simon D Taylor-Robinson

    2006-01-01

    Hepatic encephalopathy (HE) is a common neuropsychiatric abnormality, which complicates the course of patients with liver disease and results from hepatocellular failure and/or portosystemic shunting.The manifestations of HE are widely variable and involve a spectrum from mild subclinical disturbance to deep coma. Research interest has focused on the role of circulating gut-derived toxins, particularly ammonia, the development of brain swelling and changes in cerebral neurotransmitter systems that lead to global CNS depression and disordered function. Until recently the direct investigation of cerebral function has been difficult in man. However, new magnetic resonance imaging (MRI) techniques provide a non-invasive means of assessment of changes in brain volume (coregistered MRI) and impaired brain function (fMRI), while proton magnetic resonance spectroscopy (1H MRS) detects changes in brain biochemistry, including direct measurement of cerebral osmolytes, such as myoinositol, glutamate and glutamine which govern processes intrinsic to cellular homeostasis, including the accumulation of intracellular water. The concentrations of these intracellular osmolytes alter with hyperammonaemia. MRS-detected metabolite abnormalities correlate with the severity of neuropsychiatric impairment and since MR spectra return towards normal after treatment, the technique may be of use in objective patient monitoring and in assessing the effectiveness of various treatment regimens.

  8. 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...

  9. A new resonance-frequency based electrical impedance spectroscopy and its application in biomedical engineering

    Science.gov (United States)

    Dhurjaty, Sreeram; Qiu, Yuchen; Tan, Maxine; Zheng, Bin

    2014-03-01

    Electrical Impedance Spectroscopy (EIS) has shown promising results for differentiating between malignant and benign tumors, which exhibit different dielectric properties. However, the performance of current EIS systems has been inadequate and unacceptable in clinical practice. In the last several years, we have been developing and testing a new EIS approach using resonance frequencies for detection and classification of suspicious tumors. From this experience, we identified several limitations of current technologies and designed a new EIS system with a number of new characteristics that include (1) an increased A/D (analog-to-digital) sampling frequency, 24 bits, and a frequency resolution of 100 Hz, to increase detection sensitivity (2) automated calibration to monitor and correct variations in electronic components within the system, (3) temperature sensing and compensation algorithms to minimize impact of environmental change during testing, and (4) multiple inductor-switching to select optimum resonance frequencies. We performed a theoretical simulation to analyze the impact of adding these new functions for improving performance of the system. This system was also tested using phantoms filled with variety of liquids. The theoretical and experimental test results are consistent with each other. The experimental results demonstrated that this new EIS device possesses the improved sensitivity and/or signal detection resolution for detecting small impedance or capacitance variations. This provides the potential of applying this new EIS technology to different cancer detection and diagnosis tasks in the future.

  10. A nonferrous instrumental joystick device for recording behavioral responses during magnetic resonance imaging and spectroscopy.

    Science.gov (United States)

    Lukas, S E; Dobrosielski, M; Chiu, T M; Woods, B T; Teoh, S K; Mendelson, J H

    1993-12-01

    A nonferrous joystick device was developed to permit subjects to continuously report ethanol-induced alterations in subjective mood states while undergoing a magnetic resonance imaging (MRI) and magnetic resonance spectroscopy (MRS) procedure. The device utilizes air pressure (supplied by a small compressor) that is directed to a series of tubes that terminate in a hand-held unit. The hand-held unit easily fits inside the magnet and resembles a standard computer game joystick except that the ends of the air hoses replace the buttons. The control unit contains three pressure transducers, which are triggered when the tubes are occluded by the subject, activating different pens on an event marker located 6 m from the whole body imager. The unit is safe to use inside a 1.5-Tesla magnetic field and does not disrupt the MRI and MRS recording procedures. Subjective reports of ethanol-induced euphoria and intoxication paralleled the MRS detection of ethanol in the brain. This device could prove to be useful in numerous behavioral studies involving whole-body MRI and MRS.

  11. Monitoring and trace detection of hazardous waste and toxic chemicals using resonance Raman spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Sedlacek, A.J. III; Dougherty, D.R.; Chen, C.L.

    1993-04-01

    Raman scattering is a coherent, inelastic, two-photon process, which shifts the frequency of an outgoing photon according to the vibrational structure of the irradiated species, thereby providing a unique fingerprint of the molecule. When involving an allowed electronic transition (resonance Raman), this scattering cross section can be enhanced by 10{sup 4} to 10{sup 6} and provides the basis for a viable technique that can monitor and detect trace quantities of hazardous wastes and toxic chemicals. Resonance Raman spectroscopy (RRS) possesses many of the ideal characteristics for monitoring and detecting of hazardous waste and toxic chemicals. Some of these traits are: (1) very high selectivity (chemical specific fingerprints); (2) independence from the excitation wavelength (ability to monitor in the solar blind region); (3) chemical mixture fingerprints are the sum of its individual components (no spectral cross-talk); (4) near independence of the Raman fingerprint to its physical state (very similar spectra for gas, liquid, solid and solutions -- either bulk or aerosols); and (5) insensitivity of the Raman signature to environmental conditions (no quenching). Data from a few chemicals will be presented which illustrate these features. In cases where background fluorescence accompanies the Raman signals, an effective frequency modulation technique has been developed, which can completely eliminate this interference.

  12. Monitoring and trace detection of hazardous waste and toxic chemicals using resonance Raman spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Sedlacek, A.J. III; Dougherty, D.R.; Chen, C.L.

    1993-01-01

    Raman scattering is a coherent, inelastic, two-photon process, which shifts the frequency of an outgoing photon according to the vibrational structure of the irradiated species, thereby providing a unique fingerprint of the molecule. When involving an allowed electronic transition (resonance Raman), this scattering cross section can be enhanced by 10[sup 4] to 10[sup 6] and provides the basis for a viable technique that can monitor and detect trace quantities of hazardous wastes and toxic chemicals. Resonance Raman spectroscopy (RRS) possesses many of the ideal characteristics for monitoring and detecting of hazardous waste and toxic chemicals. Some of these traits are: (1) very high selectivity (chemical specific fingerprints); (2) independence from the excitation wavelength (ability to monitor in the solar blind region); (3) chemical mixture fingerprints are the sum of its individual components (no spectral cross-talk); (4) near independence of the Raman fingerprint to its physical state (very similar spectra for gas, liquid, solid and solutions -- either bulk or aerosols); and (5) insensitivity of the Raman signature to environmental conditions (no quenching). Data from a few chemicals will be presented which illustrate these features. In cases where background fluorescence accompanies the Raman signals, an effective frequency modulation technique has been developed, which can completely eliminate this interference.

  13. 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.)

  14. Magnetic resonance spectroscopy detectable metabolomic fingerprint of response to antineoplastic treatment.

    Directory of Open Access Journals (Sweden)

    Alessia Lodi

    Full Text Available Targeted therapeutic approaches are increasingly being implemented in the clinic, but early detection of response frequently presents a challenge as many new therapies lead to inhibition of tumor growth rather than tumor shrinkage. Development of novel non-invasive methods to monitor response to treatment is therefore needed. Magnetic resonance spectroscopy (MRS and magnetic resonance spectroscopic imaging are non-invasive imaging methods that can be employed to monitor metabolism, and previous studies indicate that these methods can be useful for monitoring the metabolic consequences of treatment that are associated with early drug target modulation. However, single-metabolite biomarkers are often not specific to a particular therapy. Here we used an unbiased 1H MRS-based metabolomics approach to investigate the overall metabolic consequences of treatment with the phosphoinositide 3-kinase inhibitor LY294002 and the heat shock protein 90 inhibitor 17AAG in prostate and breast cancer cell lines. LY294002 treatment resulted in decreased intracellular lactate, alanine fumarate, phosphocholine and glutathione. Following 17AAG treatment, decreased intracellular lactate, alanine, fumarate and glutamine were also observed but phosphocholine accumulated in every case. Furthermore, citrate, which is typically observed in normal prostate tissue but not in tumors, increased following 17AAG treatment in prostate cells. This approach is likely to provide further information about the complex interactions between signaling and metabolic pathways. It also highlights the potential of MRS-based metabolomics to identify metabolic signatures that can specifically inform on molecular drug action.

  15. High-resolution magnetic resonance spectroscopy in unstable fields via intermolecular zero-quantum coherences.

    Science.gov (United States)

    Lin, Meijin; Chen, Xi; Cai, Shuhui; Chen, Zhong

    2010-06-21

    Intermolecular zero-quantum coherences (iZQCs) have been utilized to achieve high-resolution nuclear magnetic resonance (NMR) proton spectra under inhomogeneous and/or unstable fields. In this paper, we demonstrated that despite the insensitivity of iZQCs to B(0) variations, the influence of unstable fields on the observable single-quantum coherence signals causes strong t(1) noises in the high-resolution iZQC spectra. Short-time acquisition (STA) and phase spectrum schemes were proposed for noise suppression in in vivo iZQC magnetic resonance spectroscopy (MRS) under temporal B(0) variations. The feasibility of these schemes were verified by localized spectroscopic studies under B(0) variations generated by the Z0 coil current oscillations and by voxel position variations in the presence of field gradients, which simulate the field conditions of MRS in the presence of physiological motions. The phase scheme not only improves the signal-to-noise ratio but also further reduces the linewidth by half.

  16. 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.

  17. Ejected-electron spectroscopy of autoionizing resonances of helium excited by fast-electron impact

    Science.gov (United States)

    Zhang, Zhe; Shan, Xu; Wang, Enliang; Chen, Xiangjun

    2012-06-01

    The autoionizing resonances (2s2)1S, (2p2)1D, and (2s2p)1P of helium have been investigated employing ejected-electron spectroscopy by fast-electron impact at incident energies of 250-2000 eV and ejected angles of 26°-116°. Shore parameters of the line shapes for these three resonances have been obtained in such high incident energy regime except at 250 eV. Distinct discrepancies between the present results at 250 eV and those of McDonald and Crowe at 200 eV [D. G. McDonald and A. Crowe, J. Phys. BJPAMA40953-407510.1088/0953-4075/25/9/018 25, 2129 (1992); D. G. McDonald and A. Crowe, J. Phys. BJPAMA40953-407510.1088/0953-4075/25/20/024 25, 4313 (1992)] and Sise at 250 eV [O. Sise, M. Dogan, I. Okur, and A. Crowe, Phys. Rev. APLRAAN1050-294710.1103/PhysRevA.84.022705 84, 022705 (2011)], especially for 1D and 1P states, are also observed.

  18. 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.

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

    Directory of Open Access Journals (Sweden)

    Shalini Agarwal

    2014-01-01

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

  20. Application of resonance Raman spectroscopy as a nuclear proliferation detection technology

    Energy Technology Data Exchange (ETDEWEB)

    Sedlacek, A.J. III; Chen, C.L.; Dougherty, D.R.

    1993-01-01

    Resonance Raman spectroscopy (RRS) potentially possesses many of the characteristics of an ideal verification technology. Some of these ideal traits are: very high selectivity and specificity to allow the deconvolution of a mixture of the chemicals of interest, high sensitivity in order to measure a species at trace levels, high reliability and long-term durability, applicability to a wide range of chemicals capability for sensing in a variety of environmental conditions, independence of the physical state of the chemical capability for quantitative analysis, and finally, but no less important capability for full signal development within seconds. In this presentation, the potential of RRS as a detection/identification technology for chemicals pertinent to nuclear materials production and processing will be assessed. A review of the basic principles behind this technique, both theoretical and experimental, will be discussed along with some recent results obtained in this laboratory. Raman scattering is a coherent, inelastic, two-photon scattering process where an exciting photon of energy hv promotes a molecule to a virtual level and the subsequently emitted photon is shifted in frequency in accordance with the rotational-vibrational structure of the irradiated species, therefore providing a unique fingerprint of the molecule. The enhancement of a Raman signal occurs when the excitation frequency is isoenergetic with an allowed electronic transition. Under resonance conditions, scattering cross-sections have been enhanced up to 6 orders of magnitude, thereby allowing the measurement of resonance Raman spectra from concentrations as dilute as 20 ppb for PAHs (with the potential of pptr). In detection/verification programs, this condition translates to increased sensitivity (ppm/ppb) and increased probing distance (m/km).

  1. Application of resonance Raman spectroscopy as a nuclear proliferation detection technology

    Energy Technology Data Exchange (ETDEWEB)

    Sedlacek, A.J. III; Chen, C.L.; Dougherty, D.R.

    1993-03-01

    Resonance Raman spectroscopy (RRS) potentially possesses many of the characteristics of an ideal verification technology. Some of these ideal traits are: very high selectivity and specificity to allow the deconvolution of a mixture of the chemicals of interest, high sensitivity in order to measure a species at trace levels, high reliability and long-term durability, applicability to a wide range of chemicals capability for sensing in a variety of environmental conditions, independence of the physical state of the chemical capability for quantitative analysis, and finally, but no less important capability for full signal development within seconds. In this presentation, the potential of RRS as a detection/identification technology for chemicals pertinent to nuclear materials production and processing will be assessed. A review of the basic principles behind this technique, both theoretical and experimental, will be discussed along with some recent results obtained in this laboratory. Raman scattering is a coherent, inelastic, two-photon scattering process where an exciting photon of energy hv promotes a molecule to a virtual level and the subsequently emitted photon is shifted in frequency in accordance with the rotational-vibrational structure of the irradiated species, therefore providing a unique fingerprint of the molecule. The enhancement of a Raman signal occurs when the excitation frequency is isoenergetic with an allowed electronic transition. Under resonance conditions, scattering cross-sections have been enhanced up to 6 orders of magnitude, thereby allowing the measurement of resonance Raman spectra from concentrations as dilute as 20 ppb for PAHs (with the potential of pptr). In detection/verification programs, this condition translates to increased sensitivity (ppm/ppb) and increased probing distance (m/km).

  2. 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

    2016-01-01

    A dual-nuclei radiofrequency coil array was constructed for phosphorus and proton magnetic resonance imaging and spectroscopy of the human brain at 7T. 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 1.4cm nominal isotropic resolution in 15min (2.3cm actual resolution), while additionally enabling 1mm 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.

  3. 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.

  4. [Characterization of biochar by X-ray photoelectron spectroscopy and 13C nuclear magnetic resonance].

    Science.gov (United States)

    Xu, Dong-yu; Jin, Jie; Yan, Yu; Han, Lan-fang; Kang, Ming-jie; Wang, Zi-ying; Zhao, Ye; Sun, Ke

    2014-12-01

    The wood (willow branch) and grass (rice straw) materials were pyrolyzed at different temperatures (300, 450 and 600 °C) to obtain the biochars used in the present study. The biochars were characterized using elementary analysis, X-ray photoelectron spectroscopy (XPS) and solid state 13C cross-polarization and magic angle spinning nuclear magnetic resonance spectroscopy (13C NMR) to illuminate the structure and composition of the biochars which were derived from the different thermal temperatures and biomass. The results showed that the H/C, O/C and (O+N)/C ratios of the biochars decreased with the increase in the pyrolysis temperatures. The surface polarity and ash content of the grass-derived biochars were higher than those of the wood-derived biochars. The minerals of the wood-derived biochars were mainly covered by the organic matter; in contrast, parts of the mineral surfaces of the grass-derived biochars were not covered by organic matter? The 13C NMR of the low temperature-derived biochars revealed a large contribution of aromatic carbon, aliphatic carbon, carboxyl and carbonyl carbon, while the high temperature-derived biochars contained a large amount of aromatic carbon. Moreover, the wood-derived biochars produced at low heat treatment temperatures contained more lignin residues than grass-derived ones, probably due to the existence of high lignin content in the feedstock soures of wood-derived biochars. The results of the study would be useful for environmental application of biochars.

  5. Angle-tunable enhanced infrared reflection absorption spectroscopy via grating-coupled surface plasmon resonance.

    Science.gov (United States)

    Petefish, Joseph W; Hillier, Andrew C

    2014-03-04

    Surface enhanced infrared absorption (SEIRA) spectroscopy is an attractive method for increasing the prominence of vibrational modes in infrared spectroscopy. To date, the majority of reports associated with SEIRA utilize localized surface plasmon resonance from metal nanoparticles to enhance electromagnetic fields in the region of analytes. Limited work has been performed using propagating surface plasmons as a method for SEIRA excitation. In this report, we demonstrate angle-tunable enhancement of vibrational stretching modes associated with a thin poly(methyl methacrylate) (PMMA) film that is coupled to a silver-coated diffraction grating. Gratings are fabricated using laser interference lithography to achieve precise surface periodicities, which can be used to generate surface plasmons that overlap with specific vibrational modes in the polymer film. Infrared reflection absorption spectra are presented for both bare silver and PMMA-coated silver gratings at a range of angles and polarization states. In addition, spectra were obtained with the grating direction oriented perpendicular and parallel to the infrared source in order to isolate plasmon enhancement effects. Optical simulations using the rigorous coupled-wave analysis method were used to identify the origin of the plasmon-induced enhancement. Angle-dependent absorption measurements achieved signal enhancements of more than 10-times the signal in the absence of the plasmon.

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

    Science.gov (United States)

    Brause, R.; Fricke, H.; Gerhards, M.; Weinkauf, R.; Kleinermanns, K.

    2006-08-01

    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 2O) 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 0 → S 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 2O) 1,2 are tentatively assigned.

  7. Distinguishing Unfolding and Functional Conformational Transitions of Calmodulin Using Ultraviolet Resonance Raman Spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Jones, Eric M.; Balakrishnan, G.; Squier, Thomas C.; Spiro, Thomas

    2014-06-14

    Calmodulin (CaM) is a ubiquitous moderator protein for calcium signaling in all eukaryotic cells. This small calcium-binding protein exhibits a broad range of structural transitions, including domain opening and folding-unfolding, that allow it to recognize a wide variety of binding partners in vivo. While the static structures of CaM associated with its various binding activities are fairly well known, it has been challenging to examine the dynamics of transition between these structures in real-time, due to a lack of suitable spectroscopic probes of CaM structure. In this paper, we examine the potential of ultraviolet resonance Raman (UVRR) spectroscopy for clarifying the nature of structural transitions in CaM. We find that the UVRR spectral change (with 229 nm excitation) due to thermal unfolding of CaM is qualitatively different from that associated with opening of the C-terminal domain in response to Ca2+ binding. This spectral difference is entirely due to differences in teritary contacts at the inter-domain tyrosine residue Tyr138, toward which other spectroscopic methods are not sensitive. We conclude that UVRR is ideally suited to identifying the different types of structural transitions in CaM and other proteins with conformation-sensitive tyrosine residues, opening a path to time-resolved studies of CaM dynamics using Raman spectroscopy.

  8. 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.

  9. Mechanism of initiation of oxidation in mayonnaise enriched with fish oil as studied by electron spin resonance spectroscopy

    DEFF Research Database (Denmark)

    Thomsen, M.K.; Jacobsen, Charlotte; Skibsted, L.H.

    2000-01-01

    Electron spin resonance spectroscopy (spin trapping technique) has been used to identify the most important single factor for initiation of lipid oxidation in mayonnaise enriched with fish oil. Low pH increases the formation of radicals during incubation under mildly accelerated conditions at 37 ...

  10. 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.

    2001-01-01

    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 sur

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

    OpenAIRE

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

    1983-01-01

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

  12. Exploring the mechanism of IR-UV double-resonance for quantitative spectroscopy of protonated polypeptides and proteins.

    Science.gov (United States)

    Nagornova, Natalia S; Rizzo, Thomas R; Boyarkin, Oleg V

    2013-06-03

    Spectroscopic fingerprint: Infrared–ultraviolet double resonance photodissociation is used for conformational assignment of the electronic spectra of a cold protonated decapeptide (see picture). A mechanism of the IR–UV depletion spectroscopy is proposed and a procedure of using it for measurements of absolute absorption cross-sections of vibrational transitions is elaborated.

  13. Cerebellar Volume and Proton Magnetic Resonance Spectroscopy at Term, and Neurodevelopment at 2 Years of Age in Preterm Infants

    Science.gov (United States)

    van Kooij, Britt J. M.; Benders, Manon J. N. L.; Anbeek, Petronella; van Haastert, Ingrid C.; de Vries, Linda S.; Groenendaal, Floris

    2012-01-01

    Aim: To assess the relation between cerebellar volume and spectroscopy at term equivalent age, and neurodevelopment at 24 months corrected age in preterm infants. Methods: Magnetic resonance imaging of the brain was performed around term equivalent age in 112 preterm infants (mean gestational age 28wks 3d [SD 1wk 5d]; birthweight 1129g [SD 324g]).…

  14. 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…

  15. 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.

    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 dete

  16. Cingulate metabolites during pain and morphine treatment as assessed by magnetic resonance spectroscopy

    Directory of Open Access Journals (Sweden)

    Hansen TM

    2014-05-01

    Full Text Available Tine Maria Hansen,1 Anne Estrup Olesen,2 Carsten Wiberg Simonsen,1 Asbjørn Mohr Drewes,2,3 Jens Brøndum Frøkjær11Mech-Sense, Department of Radiology, 2Mech-Sense, Department of Gastroenterology, 3Center for Sensory-Motor Interaction, Department of Health Science and Technology, Aalborg University, Aalborg, DenmarkBackground: Experimental investigation of cerebral mechanisms underlying pain and analgesia are important in the development of methods for diagnosis and treatment of pain. The aim of the current study was to explore brain metabolites in response to pain and treatment with morphine.Methods: Proton magnetic resonance spectroscopy of the anterior cingulate cortex was performed in 20 healthy volunteers (13 males and seven females, aged 24.9±2.6 years during rest and acute pain before and during treatment with 30 mg of oral morphine or placebo in a randomized, double-blinded, cross-over study design. Pain was evoked by skin stimulation applied to the right upper leg using a contact heat-evoked potential stimulator.Results: Data from 12 subjects were valid for analysis. Painful stimulation induced an increase in N-acetylaspartate/creatine compared with rest (F=5.5, P=0.04. During treatment with morphine, painful stimulation induced decreased glutamate/creatine (F=7.3, P=0.02, myo-inositol/creatine (F=8.38, P=0.02, and N-acetylaspartate/creatine (F=13.8, P=0.004 concentrations, whereas an increase in the pain-evoked N-acetylaspartate/creatine concentration (F=6.1, P=0.04 was seen during treatment with placebo.Conclusion: This explorative study indicates that neuronal metabolites in the anterior cingulate cortex, such as N-acetylaspartate, glutamate, and myo-inositol, could be related to the physiology of pain and treatment with morphine. This experimental method has the potential to enable the study of brain metabolites involved in pain and its treatment, and may in the future be used to provide further insight into these mechanisms

  17. 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

  18. 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

  19. 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.

  20. Resonant Raman spectroscopy study of swift heavy ion irradiated MoS2

    Science.gov (United States)

    Guo, Hang; Sun, Youmei; Zhai, Pengfei; Zeng, Jian; Zhang, Shengxia; Hu, Peipei; Yao, Huijun; Duan, Jinglai; Hou, Mingdong; Liu, Jie

    2016-08-01

    Molybdenum disulphide (MoS2) crystal samples were irradiated by swift heavy ions (209Bi and 56Fe). Hillock-like latent tracks were observed on the surface of irradiated MoS2 by atomic force microscopy. The modifications of properties of irradiated MoS2 were investigated by resonant Raman spectroscopy and ultraviolet-visible spectroscopy (UV-Vis). A new peak (E1u2, ∼385.7 cm-1) occurs near the in-plane E2g1 peak (∼383.7 cm-1) after irradiation. The two peaks shift towards lower frequency and broaden due to structural defects and stress with increasing fluence. When irradiated with high fluence, two other new peaks appear at ∼ 190 and ∼ 230 cm-1. The peak at ∼230 cm-1 is disorder-induced LA(M) mode. The presence of this mode indicates defects induced by irradiation. The feature at ∼460 cm-1 is composed of 2LA(M) (∼458 cm-1) and A2u (∼466 cm-1) mode. With increasing fluence, the integrated intensity ratio between 2LA(M) and A2u increases. The relative enhancement of 2LA(M) mode is in agreement with the appearance of LA(M) mode, which both demonstrate structural disorder in irradiated MoS2. The ∼423-cm-1 peak shifts toward lower frequency due to the decrease in exciton energy of MoS2, and this was demonstrated by the results of UV-Vis spectra. The decrease in exciton energy could be due to introduction of defect levels into band gap.

  1. Magnetic resonance Spectroscopy with Linear Algebraic Modeling (SLAM) for higher speed and sensitivity.

    Science.gov (United States)

    Zhang, Yi; Gabr, Refaat E; Schär, Michael; Weiss, Robert G; Bottomley, Paul A

    2012-05-01

    Speed and signal-to-noise ratio (SNR) are critical for localized magnetic resonance spectroscopy (MRS) of low-concentration metabolites. Matching voxels to anatomical compartments a priori yields better SNR than the spectra created by summing signals from constituent chemical-shift-imaging (CSI) voxels post-acquisition. Here, a new method of localized Spectroscopy using Linear Algebraic Modeling (SLAM) is presented, that can realize this additional SNR gain. Unlike prior methods, SLAM generates spectra from C signal-generating anatomic compartments utilizing a CSI sequence wherein essentially only the C central k-space phase-encoding gradient steps with highest SNR are retained. After MRI-based compartment segmentation, the spectra are reconstructed by solving a sub-set of linear simultaneous equations from the standard CSI algorithm. SLAM is demonstrated with one-dimensional CSI surface coil phosphorus MRS in phantoms, the human leg and the heart on a 3T clinical scanner. Its SNR performance, accuracy, sensitivity to registration errors and inhomogeneity, are evaluated. Compared to one-dimensional CSI, SLAM yielded quantitatively the same results 4-times faster in 24 cardiac patients and healthy subjects. SLAM is further extended with fractional phase-encoding gradients that optimize SNR and/or minimize both inter- and intra-compartmental contamination. In proactive cardiac phosphorus MRS of six healthy subjects, both SLAM and fractional-SLAM (fSLAM) produced results indistinguishable from CSI while preserving SNR gains of 36-45% in the same scan-time. Both SLAM and fSLAM are simple to implement and reduce the minimum scan-time for CSI, which otherwise limits the translation of higher SNR achievable at higher field strengths to faster scanning.

  2. Magnetic resonance Spectroscopy with Linear Algebraic Modeling (SLAM) for higher speed and sensitivity

    Science.gov (United States)

    Zhang, Yi; Gabr, Refaat E.; Schär, Michael; Weiss, Robert G.; Bottomley, Paul A.

    2012-05-01

    Speed and signal-to-noise ratio (SNR) are critical for localized magnetic resonance spectroscopy (MRS) of low-concentration metabolites. Matching voxels to anatomical compartments a priori yields better SNR than the spectra created by summing signals from constituent chemical-shift-imaging (CSI) voxels post-acquisition. Here, a new method of localized Spectroscopy using Linear Algebraic Modeling (SLAM) is presented, that can realize this additional SNR gain. Unlike prior methods, SLAM generates spectra from C signal-generating anatomic compartments utilizing a CSI sequence wherein essentially only the C central k-space phase-encoding gradient steps with highest SNR are retained. After MRI-based compartment segmentation, the spectra are reconstructed by solving a sub-set of linear simultaneous equations from the standard CSI algorithm. SLAM is demonstrated with one-dimensional CSI surface coil phosphorus MRS in phantoms, the human leg and the heart on a 3T clinical scanner. Its SNR performance, accuracy, sensitivity to registration errors and inhomogeneity, are evaluated. Compared to one-dimensional CSI, SLAM yielded quantitatively the same results 4-times faster in 24 cardiac patients and healthy subjects. SLAM is further extended with fractional phase-encoding gradients that optimize SNR and/or minimize both inter- and intra-compartmental contamination. In proactive cardiac phosphorus MRS of six healthy subjects, both SLAM and fractional-SLAM (fSLAM) produced results indistinguishable from CSI while preserving SNR gains of 36-45% in the same scan-time. Both SLAM and fSLAM are simple to implement and reduce the minimum scan-time for CSI, which otherwise limits the translation of higher SNR achievable at higher field strengths to faster scanning.

  3. 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.

  4. Determination of resonance Raman cross-sections for use in biological SERS sensing with femtosecond stimulated Raman spectroscopy.

    Science.gov (United States)

    Silva, W Ruchira; Keller, Emily L; Frontiera, Renee R

    2014-08-05

    Surface-enhanced Raman spectroscopy (SERS) is a promising technique for in vivo bioanalyte detection, but accurate characterization of SERS biosensors can be challenging due to difficulties in differentiating resonance and surface enhancement contributions to the Raman signal. Here, we quantitate the resonance Raman cross-sections for a commonly used near-infrared SERS dye, 3,3'-diethylthiatricarbocyanine (DTTC). It is typically challenging to measure resonance Raman cross-sections for fluorescent dye molecules due to the overwhelming isoenergetic fluorescence signal. To overcome this issue, we used etalon-based femtosecond stimulated Raman spectroscopy, which is intrinsically designed to acquire a stimulated Raman signal without strong fluorescence or interference from signals resulting from other four-wave mixing pathways. Using this technique, we found that the cross-sections for most of the resonantly enhanced modes in DTTC exceed 10(-25) cm(2)/molecule. These cross-sections lead to high signal magnitude SERS signals from even weakly enhancing SERS substrates, as much of what appears to be a SERS signal is actually coming from the intrinsically strong resonance Raman signal. Our work will lead to a more accurate determination of SERS enhancement factors and SERS substrate characterization in the biologically relevant near-infrared region, ultimately leading to a more widespread use of SERS for biosensing and bioimaging applications.

  5. 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.

  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.

  7. Current Role and Future Perspectives of Magnetic Resonance Spectroscopy in Radiation Oncology for Prostate Cancer

    Directory of Open Access Journals (Sweden)

    Aleksandra Zapotoczna

    2007-06-01

    Full Text Available Prostatic neoplasms are not uniformly distributed within the prostate volume. With recent developments in three-dimensional intensity-modulated and imageguided radiation therapy, it is possible to treat different volumes within the prostate to different thresholds of doses. This approach has the potential to adapt the dose to the biologic aggressiveness of various clusters of tumor cells within the gland. The definition of tumor burden volume in prostate cancer can be facilitated by the use of magnetic resonance spectroscopy (MRS. The increasing sensitivity and specificity of MRS to the prostate is causing new interest in its potential role in the definition of target subvolumes at higher risk of failure following radical radiotherapy. Prostate MRS might also play a role as a noninvasive predictive factor for tumor response and treatment outcome. We review the use of MRS in radiation therapy for prostate cancer by evaluating its accuracy in the classification of aggressive cancer regions and target definition; its current role in the radiotherapy planning process, with special interest in technical issues behind the successful inclusion of MRS in clinical use; and available early experiences as a prognostic tool.

  8. Biochemical support for the "threshold" theory of creativity: a magnetic resonance spectroscopy study.

    Science.gov (United States)

    Jung, Rex E; Gasparovic, Charles; Chavez, Robert S; Flores, Ranee A; Smith, Shirley M; Caprihan, Arvind; Yeo, Ronald A

    2009-04-22

    A broadly accepted definition of creativity refers to the production of something both novel and useful within a given social context. Studies of patients with neurological and psychiatric disorders and neuroimaging studies of healthy controls have each drawn attention to frontal and temporal lobe contributions to creativity. Based on previous magnetic resonance (MR) spectroscopy studies demonstrating relationships between cognitive ability and concentrations of N-acetyl-aspartate (NAA), a common neurometabolite, we hypothesized that NAA assessed in gray and white matter (from a supraventricular slab) would relate to laboratory measures of creativity. MR imaging and divergent thinking measures were obtained in a cohort of 56 healthy controls. Independent judges ranked the creative products of each participant, from which a "Composite Creativity Index" (CCI) was created. Different patterns of correlations between NAA and CCI were found in higher verbal ability versus lower verbal ability participants, providing neurobiological support for a critical "threshold" regarding the relationship between intelligence and creativity. To our knowledge, this is the first report assessing the relationship between brain chemistry and creative cognition, as measured with divergent thinking, in a cohort comprised exclusively of normal, healthy participants.

  9. Discrete magic angle turning system, apparatus, and process for in situ magnetic resonance spectroscopy and imaging

    Science.gov (United States)

    Hu, Jian Zhi; Sears, Jr., Jesse A.; Hoyt, David W.; Wind, Robert A.

    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.

  10. Electron paramagnetic resonance (EPR) spectroscopy characterization of wheat grains from plants of different water stress tolerance.

    Science.gov (United States)

    Łabanowska, Maria; Filek, Maria; Kurdziel, Magdalena; Bednarska, Elżbieta; Dłubacz, Aleksandra; Hartikainen, Helina

    2012-09-01

    Grains of five genotypes of wheat (four Polish and one Finnish), differing in their tolerance to drought stress were chosen for this investigation. Electron paramagnetic resonance spectroscopy allowed observation of transition metal ions (Mn, Fe, Cu) and different types of stable radicals, including semiquinone centers, present in seed coats, as well as several types of carbohydrate radicals found mainly in the inner parts of grains. The content of paramagnetic metal centers was higher in sensitive genotypes (Radunia, Raweta) than in tolerant ones (Parabola, Nawra), whereas the Finnish genotype (Manu) exhibited intermediate amounts. Similarly, the concentrations of both types of radicals, carbohydrates and semiquinone were significantly higher in the grains originating from more sensitive wheat genotypes. The nature of carbohydrate radicals and their concentrations were confronted with the kinds and amounts of sugars found by the biochemical analyses and microscopy observations. It is suggested that some long lived radicals (semiquinone and starch radicals) occurring in grains could be indicators of stress resistance of wheat plants.

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

    Science.gov (United States)

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

    2016-01-01

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

  12. Proteomics, and metabolomics: magnetic resonance spectroscopy for the presurgical screening of thyroid nodules.

    Science.gov (United States)

    Minuto, Michele N; Shintu, Laetitia; Caldarelli, Stefano

    2014-06-01

    We review the progress and state-of-the-art applications of studies in Magnetic Resonance Spectroscopy (MRS) and Imaging as an aid for diagnosis of thyroid lesions of different nature, especially focusing our attention to those lesions that are cytologically undetermined. It appears that the high-resolution of High-Resolution Magic-Angle-Spinning (HRMAS) MRS improves the overall accuracy of the analysis of thyroid lesions to a point that a significant improvement in the diagnosis of cytologically undetermined lesions can be expected. This analysis, in the meantime, allows a more precise comprehension of the alterations in the metabolic pathways induced by the development of the different tumors. Although these results are promising, at the moment, a clinical application of the method to the common workup of thyroid nodules cannot be used, due to both the limitation in the availability of this technology and the wide range of techniques, that are not uniformly used. The coming future will certainly see a wider application of these methods to the clinical practice in patients affected with thyroid nodules and various other neoplastic diseases.

  13. Chemical shift imaging and localised magnetic resonance spectroscopy in full-term asphyxiated neonates

    Energy Technology Data Exchange (ETDEWEB)

    Brissaud, Olivier [Children' s Hospital, Paediatric Intensive Care Unit, Bordeaux (France); Chateil, Jean-Francois; Bordessoules, Martine; Brun, Muriel [Children' s Hospital, Radiology Unit, Bordeaux (France)

    2005-10-01

    Diagnosis of brain lesions after birth anoxia-ischemia is essential for appropriate management. Clinical evaluation is not sufficient. MRI has been proven to provide useful information. To compare abnormalities observed with MRI, including diffusion-weighted imaging (DWI), localised magnetic resonance spectroscopy (MRS) and chemical shift imaging (CSI) and correlate these findings with the clinical outcome. Fourteen full-term neonates with birth asphyxia were studied. MRI, MRS and CSI were performed within the first 4 days of life. Lesions observed with DWI were correlated with outcome, but the apparent diffusion coefficient (ADC) did improve diagnostic confidence. The mean value of Lac/Cr for the neonates with a favourable outcome was statically lower than for those who died (0.22 vs 1.04; P = 0.01). The same results were observed for the Lac/NAA ratio (0.21 vs 1.23; P = 0.01). Data obtained with localised MRS and CSI were correlated for the ratio N-acetyl-aspartate/choline, but not for the other metabolites. No correlation was found between the ADC values and the metabolite ratios. Combination of these techniques could be helpful in our understanding of the physiopathological events occurring in neonates with asphyxia. (orig.)

  14. 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.

  15. Biochemical Support for the “Threshold” Theory of Creativity: A Magnetic Resonance Spectroscopy Study

    Science.gov (United States)

    Jung, Rex E.; Gasparovic, Charles; Chavez, Robert S.; Flores, Ranee A.; Smith, Shirley M.; Caprihan, Arvind; Yeo, Ronald A.

    2009-01-01

    A broadly accepted definition of creativity refers to the production of something both novel and useful within a given social context. Studies of patients with neurological and psychiatric disorders and neuroimaging studies of healthy controls have each drawn attention to frontal and temporal lobe contributions to creativity. Based on previous magnetic resonance (MR) spectroscopy studies demonstrating relationships between cognitive ability and concentrations of N-acetyl-aspartate (NAA), a common neurometabolite, we hypothesized that NAA assessed in gray and white matter (from a supraventricular slab) would relate to laboratory measures of creativity. MR imaging and divergent thinking measures were obtained in a cohort of 56 healthy controls. Independent judges ranked the creative products of each participant, from which a “Composite Creativity Index” (CCI) was created. Different patterns of correlations between NAA and CCI were found in higher verbal ability versus lower verbal ability participants, providing neurobiological support for a critical “threshold” regarding the relationship between intelligence and creativity. To our knowledge, this is the first report assessing the relationship between brain chemistry and creative cognition, as measured with divergent thinking, in a cohort comprised exclusively of normal, healthy participants. PMID:19386928

  16. Ion chemistry and gas-phase basicity of nickelocene by ion cyclotron resonance spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Corderman, R.R.; Beauchamp, J.L.

    1976-01-01

    The gas-phase ion chemistry of bis(eta/sup 5/-cyclopentadienyl)nickel(nickelocene) is studied using the techniques of ion cyclotron resonance spectroscopy. Total rate constants for the reactions of the primary fragment ions at 70 eV are determined using trapped-ion methods. The long-lived nickelocene anion, Ni(C/sub 5/H/sub 5/)/sub 2//sup -/, is formed directly by electron attachment and is unreactive with a variety of simple molecules. Nickelocene is observed to be an exceptionally strong base in the gas phase. Equilibrium proton-transfer reactions are observed in mixtures of nickelocene with (CH/sub 3/)/sub 3/N and (C/sub 2/H/sub 5/)/sub 2/NH, from which the gas-phase basicity or proton affinity (PA) is determined to be 218.9 +- 1.0 kcal/mol relative to PA(NH/sub 3/) = 201 +- 1 kcal/mol. Attempts to determine the site of protonation were inconclusive. The ion chemistry and base strength of nickelocene and ferrocene are compared. 39 references, 2 figures, 3 tables.

  17. Ion chemistry and gas-phase basicity of nickelocene by ion cyclotron resonance spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Corderman, R.D.; Beauchamp, J.L.

    1976-03-01

    The gas-phase ion chemistry of bis(eta/sup 5/-cyclopentadienyl)nickel (nickelocene) is studied using the techniques of ion cyclotron resonance spectroscopy. Total rate constants for the reactions of the primary fragment ions at 70 eV are determined using trapped-ion methods. The long-lived nickelocene anion, Ni(C/sub 5/H/sub 5/)/sub 2//sup -/, is formed directly by electron attachment and is unreactive with a variety of simple molecules. Nickelocene is observed to be an exceptionally strong base in the gas phase. Equilibrium proton-transfer reactions are observed in mixtures of nickelocene with (CH/sub 3/)/sub 3/N and (C/sub 2/H/sub 5/)/sub 2/NH, from which the gas-phase basicity or proton affinity (PA) is determined to be 218.9 +- 1.0 kcal/mol relative to PA(NH/sub 3/) = 201 +- 1 kcal/mol. Attempts to determine the site of protonation were inconclusive. The ion chemistry and base strength of nickelocene and ferrocene are compared. (auth)

  18. Absolute quantification for benzoic acid in processed foods using quantitative proton nuclear magnetic resonance spectroscopy.

    Science.gov (United States)

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

    2012-09-15

    The absolute quantification method of benzoic acid (BA) in processed foods using solvent extraction and quantitative proton nuclear magnetic resonance spectroscopy was developed and validated. BA levels were determined using proton signals (δ(H) 7.53 and 7.98) referenced to 2-dimethyl-2-silapentane-5-sulfonate-d(6) sodium salt (DSS-d(6)) after simple solvent extraction from processed foods. All recoveries from several kinds of processed foods, spiked at their specified maximum Japanese usage levels (0.6-2.5 g kg(-1)) and at 0.13 g kg(-1) and 0.063 g kg(-1), were greater than 80%. The limit of quantification was confirmed as 0.063 g kg(-1) in processed foods, which was sufficiently low for the purposes of monitoring BA. The accuracy of the proposed method is equivalent to the conventional method using steam-distillation extraction and high-performance liquid chromatography. The proposed method was both rapid and simple. Moreover, it provided International System of Units traceability without the need for authentic analyte standards. Therefore, the proposed method is a useful and practical tool for determining BA levels in processed foods.

  19. 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.

  20. Blend uniformity analysis of pharmaceutical products by Broadband Acoustic Resonance Dissolution Spectroscopy (BARDS).

    Science.gov (United States)

    Fitzpatrick, Dara; Scanlon, Eoin; Krüse, Jacob; Vos, Bastiaan; Evans-Hurson, Rachel; Fitzpatrick, Eileen; McSweeney, Seán

    2012-11-15

    Blend uniformity analysis (BUA) is a routine and highly regulated aspect of pharmaceutical production. In most instances, it involves quantitative determination of individual components of a blend in order to ascertain the mixture ratio. This approach often entails the use of costly and sophisticated instrumentation and complex statistical methods. In this study, a new and simple qualitative blend confirmatory test is introduced based on a well known acoustic phenomenon. Several over the counter (OTC) product powder blends are analysed and it is shown that each product has a unique and highly reproducible acoustic signature. The acoustic frequency responses generated during the dissolution of the product are measured and recorded in real time. It is shown that intra-batch and inter-batch variation for each product is either insignificant or non-existent when measured in triplicate. This study demonstrates that Broadband Acoustic Resonance Dissolution Spectroscopy or BARDS can be used successfully to determine inter-batch variability, stability and uniformity of powder blends. This is just one application of a wide range of BARDS applications which are more cost effective and time efficient than current methods.

  1. Double-resonance spectroscopy in Rubidium vapour-cells for high performance and miniature atomic clocks

    Science.gov (United States)

    Gharavipour, M.; Affolderbach, C.; Kang, S.; Mileti, G.

    2017-01-01

    We report our studies on using microwave-optical double-resonance (DR) spectroscopy for a high-performance Rb vapour-cell atomic clock in view of future industrial applications. The clock physics package is very compact with a total volume of only 0.8 dm3. It contains a recently in-house developed magnetron-type cavity and a Rb vapour cell. A homed-made frequency-stabilized laser system with an integrated acousto-optical-modulator (AOM) – for switching and controlling the light output power– is used as an optical source in a laser head (LH). The LH has the overall volume of 2.5 dm3 including the laser diode, optical elements, AOM and electronics. In our Rb atomic clock two schemes of continuous-wave DR and Ramsey-DR schemes are used, where the latter one strongly reduces the light-shift effect by separation of the interaction of light and microwave. Applications of the DR clock approach to more radically miniaturized atomic clocks are discussed.

  2. 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.)

  3. Magnetic Resonance Spectroscopy: An In Vivo Molecular Imaging Biomarker for Parkinson’s Disease?

    Directory of Open Access Journals (Sweden)

    Rosella Ciurleo

    2014-01-01

    Full Text Available Parkinson’s disease (PD is a neurodegenerative disorder caused by selective loss of dopaminergic neurons in the substantia nigra pars compacta which leads to dysfunction of cerebral pathways critical for the control of movements. The diagnosis of PD is based on motor symptoms, such as bradykinesia, akinesia, muscular rigidity, postural instability, and resting tremor, which are evident only after the degeneration of a significant number of dopaminergic neurons. Currently, a marker for early diagnosis of PD is still not available. Consequently, also the development of disease-modifying therapies is a challenge. Magnetic resonance spectroscopy is a quantitative imaging technique that allows in vivo measurement of certain neurometabolites and may produce biomarkers that reflect metabolic dysfunctions and irreversible neuronal damage. This review summarizes the abnormalities of cerebral metabolites found in MRS studies performed in patients with PD and other forms of parkinsonism. In addition, we discuss the potential role of MRS as in vivo molecular imaging biomarker for early diagnosis of PD and for monitoring the efficacy of therapeutic interventions.

  4. On-line monitoring of chemical reactions by using bench-top nuclear magnetic resonance spectroscopy.

    Science.gov (United States)

    Danieli, E; Perlo, J; Duchateau, A L L; Verzijl, G K M; Litvinov, V M; Blümich, B; Casanova, F

    2014-10-06

    Real-time nuclear magnetic resonance (NMR) spectroscopy measurements carried out with a bench-top system installed next to the reactor inside the fume hood of the chemistry laboratory are presented. To test the system for on-line monitoring, a transfer hydrogenation reaction was studied by continuously pumping the reaction mixture from the reactor to the magnet and back in a closed loop. In addition to improving the time resolution provided by standard sampling methods, the use of such a flow setup eliminates the need for sample preparation. Owing to the progress in terms of field homogeneity and sensitivity now available with compact NMR spectrometers, small molecules dissolved at concentrations on the order of 1 mmol L(-1) can be characterized in single-scan measurements with 1 Hz resolution. Owing to the reduced field strength of compact low-field systems compared to that of conventional high-field magnets, the overlap in the spectrum of different NMR signals is a typical situation. The data processing required to obtain concentrations in the presence of signal overlap are discussed in detail, methods such as plain integration and line-fitting approaches are compared, and the accuracy of each method is determined. The kinetic rates measured for different catalytic concentrations show good agreement with those obtained with gas chromatography as a reference analytical method. Finally, as the measurements are performed under continuous flow conditions, the experimental setup and the flow parameters are optimized to maximize time resolution and signal-to-noise ratio.

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

    Science.gov (United States)

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

    2012-07-01

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

  6. Anthocyanin composition of wild Colombian fruits and antioxidant capacity measurement by electron paramagnetic resonance spectroscopy.

    Science.gov (United States)

    Santacruz, Liliana; Carriazo, José G; Almanza, Ovidio; Osorio, Coralia

    2012-02-15

    The qualitative and quantitative anthocyanin composition of four wild tropical fruits from Colombia was studied. Compounds of "mora pequeña" ( Rubus megalococcus Focke.), "uva de árbol" ( Myrciaria aff. cauliflora O. Berg), coral, and motilón ( Hyeronima macrocarpa Mull. Arg.) fruits were separately extracted with methanol-acetic acid (95:5, v/v). The anthocyanin-rich extracts (AREs) were obtained by selective adsorption on Amberlite XAD-7. Each extract was analyzed by HPLC-PDA and HPLC-HRESI-MS(n) with LCMS-IT-TOF equipment in order to characterize the anthocyanin pigments and the coinjection in HPLC using standards allowed identifying the major constituents in each extract. The antioxidant activity was measured by electron paramagnetic resonance (EPR) and UV-vis spectroscopy, using ABTS and DPPH free radicals. The ARE of motilón ( H. macrocarpa Müll. Arg) exhibited the highest radical scavenging activity in comparison to the other extracts. A second-order kinetic model was followed in all of the cases. These results suggested that the studied fruits are promising not only as source of natural pigments but also as antioxidant materials for food industry.

  7. Proton magnetic resonance spectroscopy detection of neurotransmitters in dorsomedial medulla correlate with spontaneous baroreceptor reflex function.

    Science.gov (United States)

    Garcia-Espinosa, Maria A; Shaltout, Hossam A; Olson, John; Westwood, Brian M; Robbins, Mike E; Link, Kerry; Diz, Debra I

    2010-02-01

    Control of heart rate variability via modulation of sympathovagal balance is a key function of nucleus tractus solitarii and the dorsal motor nucleus of the vagus localized in the dorsomedial medulla oblongata. Normal blood pressure regulation involves precise balance of glutamate (Glu)-glutamine-gamma-aminobutyric acid transmitter systems, and angiotensin II modulates these transmitters to produce tonic suppression of reflex function. It is not known, however, whether other brain transmitters/metabolites are indicators of baroreflex function. This study establishes the concept that comprehensive baseline transmitter/metabolite profiles obtained using in vivo (1)H magnetic resonance spectroscopy in rats with well-characterized differences in resting blood pressure and baroreflex function can be used as indices of autonomic balance or baroreflex sensitivity. Transgenic rats with over-expression of renin [m(Ren2)27] or under-expression of glial-angiotensinogen (ASrAogen) were compared with Sprague-Dawley rats. Glu concentration in the dorsal medulla is significantly higher in ASrAogen rats compared with either Sprague-Dawley or (mRen2)27 rats. Glu levels and the ratio of Glu:glutamine correlated positively with indices of higher vagal tone consistent with the importance of these neurotransmitters in baroreflex function. Interestingly, the levels of choline-containing metabolites showed a significant positive correlation with spontaneous baroreflex sensitivity and a negative correlation with sympathetic tone. Thus, we demonstrate the concept that noninvasive assessment of neurochemical biomarkers may be used as an index of baroreflex sensitivity.

  8. 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).

  9. Proton nuclear magnetic resonance spectroscopy based investigation on propylene glycol toxicosis in a Holstein cow

    Directory of Open Access Journals (Sweden)

    Raun Birgitte-Marie L

    2009-06-01

    Full Text Available Abstract Background It is unknown which metabolites are responsible for propylene glycol (PG-induced toxicosis, and a better understanding of the underlying mechanisms explaining incidences of abnormal behaviour of dairy cows fed PG is therefore needed. Methods The study included three cows of which one developed PG toxicosis. In order to investigate how the metabolism of PG differed in the cow developing toxicosis, proton nuclear magnetic resonance (NMR spectroscopy was applied on ruminal fluids and blood plasma samples obtained before and after feeding with PG. Results PG toxicosis was characterized by dyspnea and ruminal atony upon intake of concentrate containing PG. The oxygen saturation of arterial blood haemoglobin and the oxygen pressure in arterial blood decreased along with the appearance of the clinical symptoms. NMR revealed differences in plasma and ruminal content of several metabolites between the cow responding abnormally to PG and the two control cows. Conclusion It is concluded that PG-toxicosis is likely caused by pulmonary vasoconstriction, but no unusual metabolites directly related to induction of this condition could be detected in the plasma or the ruminal fluid.

  10. 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.

  11. Low skin carotenoid concentration measured by resonance Raman spectroscopy is associated with metabolic syndrome in adults.

    Science.gov (United States)

    Holt, Edward W; Wei, Esther K; Bennett, Nancy; Zhang, Laura M

    2014-10-01

    Oxidative stress is increased in patients with metabolic syndrome (MS). Antioxidants, including carotenoids, are decreased in MS. We hypothesized that a low skin carotenoid score (SCS), calculated using resonance Raman spectroscopy, would correlate with the presence of MS. We retrospectively reviewed consecutive patients referred for dietary assessment between 2010 and 2012. For each patient, a nutrition history, medical history, and SCS were recorded. χ(2) and Student t test were used to determine factors associated with MS. Multivariate logistic regression was used to identify factors associated with MS. One hundred fifty-five patients were included. The mean age was 54.1 ± 13.1 years, and the mean body mass index was 28.3 ± 6.1 kg/m(2). Metabolic syndrome was present in 43.9% of patients. The mean SCS was 28 084 ± 14 006 Raman counts (RC), including 23 058 ± 9812 RC for patients with MS and 32 011 ± 15 514 RC for patients without MS (P = .0001). In a multivariate analysis, SCS less than 25 000 RC (odds ratio, 3.71; 95% confidence interval, 1.36-10.7; P = .01) was independently associated with MS. A higher number of MS components was associated with a progressively lower SCS (P = .004). In a consecutive sample of patients referred for dietary assessment, a noninvasively measured SCS was lower among patients with MS.

  12. Molecular dynamics in rod-like liquid crystals probed by muon spin resonance spectroscopy.

    Science.gov (United States)

    McKenzie, Iain; Scheuermann, Robert; Sedlak, Kamil; Stoykov, Alexey

    2011-08-01

    Muoniated spin probes were produced by the addition of muonium (Mu) to two rod-like liquid crystals: N-(4-methoxybenzylidene)-4'-n-butylaniline (MBBA) and cholesteryl nonanoate (CN). Avoided level crossing muon spin resonance spectroscopy was used to characterize the muoniated spin probes and to probe dynamics at the molecular level. In MBBA Mu adds predominantly to the carbon of the bridging imine group and the muon and methylene proton hyperfine coupling constants (hfccs) of the resulting radical shift in the nematic phase due to the dipolar hyperfine coupling, the ordering of the molecules along the applied magnetic field and fluctuations about the local director. The amplitude of these fluctuations in in the nematic phase of MBBA is determined from the temperature dependence of the methylene proton hfcc. Mu adds to the double bond of the steroidal ring system of CN and the temperature dependence of the Δ(1) line width provides information about the amplitude of the fluctuations about the local director in the chiral nematic phase and the slow isotropic reorientation in the isotropic phase.

  13. 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.

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

    Science.gov (United States)

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

    2011-06-01

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

  15. Java-based framework for processing and displaying short-echo-time magnetic resonance spectroscopy signals.

    Science.gov (United States)

    De Neuter, B; Luts, J; Vanhamme, L; Lemmerling, P; Van Huffel, S

    2007-02-01

    Magnetic resonance spectroscopy (MRS) can be used to determine in a non-invasive way the concentrations of certain chemical substances, also called metabolites. The spectra of MRS signals contain peaks that correspond to the metabolites of interest. Short-echo-time signals are characterized by heavily overlapping metabolite peaks and require sophisticated processing methods. To be useful in a clinical environment tools are needed that can process those signals in an accurate and fast way. Therefore, we developed novel processing methods and we designed a freely available and open-source framework (http://www.esat.kuleuven.ac.be/sista/members/biomed) in which the processing methods can be integrated. The framework has a set of abstract classes, called hot spots, and its goal is to provide a general structure and determine the control flow of the program. It provides building blocks or components in order to help developers with integrating their methods in the framework via a plug-in system. The framework is designed with the unified modeling language (UML) and implemented in Java. When a developer implements the framework he gets an application that acts like a simple and user-friendly graphical user interface (GUI) for processing MRS data. This article describes in detail the structure and implementation of the framework and the integration of our processing methods in it.

  16. High-resolution monochromator for iron nuclear resonance vibrational spectroscopy of biological samples

    Science.gov (United States)

    Yoda, Yoshitaka; Okada, Kyoko; Wang, Hongxin; Cramer, Stephen P.; Seto, Makoto

    2016-12-01

    A new high-resolution monochromator for 14.4-keV X-rays has been designed and developed for the Fe nuclear resonance vibrational spectroscopy of biological samples. In addition to high resolution, higher flux and stability are especially important for measuring biological samples, because of the very weak signals produced due to the low concentrations of Fe-57. A 24% increase in flux while maintaining a high resolution better than 0.9 meV is achieved in the calculation by adopting an asymmetric reflection of Ge, which is used as the first crystal of the three-bounce high-resolution monochromator. A 20% increase of the exit beam size is acceptable to our biological applications. The higher throughput of the new design has been experimentally verified. A fine rotation mechanics that combines a weak-link hinge with a piezoelectric actuator was used for controlling the photon energy of the monochromatic beam. The resulting stability is sufficient to preserve the intrinsic resolution.

  17. Resonant Mie scattering in infrared spectroscopy of biological materials--understanding the 'dispersion artefact'.

    Science.gov (United States)

    Bassan, Paul; Byrne, Hugh J; Bonnier, Franck; Lee, Joe; Dumas, Paul; Gardner, Peter

    2009-08-01

    Infrared spectroscopic cytology is potentially a powerful clinical tool. However, in order for it to be successful, practitioners must be able to extract reliably a pure absorption spectrum from a measured spectrum that often contains many confounding factors. The most intractable problem to date is the, so called, dispersion artefact which most prominently manifests itself as a sharp decrease in absorbance on the high wavenumber side of the amide I band in the measured spectrum, exhibiting a derivative-like line shape. In this paper we use synchrotron radiation FTIR micro-spectroscopy to record spectra of mono-dispersed poly(methyl methacrylate) (PMMA) spheres of systematically varying size and demonstrate that the spectral distortions in the data can be understood in terms of resonant Mie scattering. A full understanding of this effect will enable us to develop strategies for deconvolving the scattering contribution and recovering the pure absorption spectrum, thus removing one of the last technological barriers to the development of clinical spectroscopic cytology.

  18. Quantitative detection of astaxanthin and cantaxanthin in Atlantic salmon by resonance Raman spectroscopy

    Science.gov (United States)

    Ermakov, Igor V.; Ermakova, Maia R.; Gellermann, Werner

    2006-02-01

    Two major carotenoids species found in salmonids muscle tissues are astaxanthin and cantaxanthin. They are taken up from fish food and are responsible for the attractive red-orange color of salmon filet. Since carotenoids are powerful antioxidants and biomarkers of nutrient consumption, they are thought to indicate fish health and resistance to diseases in fish farm environments. Therefore, a rapid, accurate, quantitative optical technique for measuring carotenoid content in salmon tissues is of economic interest. We demonstrate the possibility of using fast, selective, quantitative detection of astaxanthin and cantaxanthin in salmon muscle tissues, employing resonance Raman spectroscopy. Analyzing strong Raman signals originating from the carbon-carbon double bond stretch vibrations of the carotenoid molecules under blue laser excitation, we are able to characterize quantitatively the concentrations of carotenoids in salmon muscle tissue. To validate the technique, we compared Raman data with absorption measurements of carotenoid extracts in acetone. A close correspondence was observed in absorption spectra for tissue extract in acetone and a pure astaxanthin solution. Raman results show a linear dependence between Raman and absorption data. The proposed technique holds promise as a method of rapid screening of carotenoid levels in fish muscle tissues and may be attractive for the fish farm industry to assess the dietary status of salmon, risk for infective diseases, and product quality control.

  19. Magnetic Resonance Spectroscopy in Patients with Insomnia: A Repeated Measurement Study.

    Science.gov (United States)

    Spiegelhalder, Kai; Regen, Wolfram; Nissen, Christoph; Feige, Bernd; Baglioni, Chiara; Riemann, Dieter; Hennig, Jürgen; Lange, Thomas

    2016-01-01

    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.

  20. Neurometabolic abnormalities in schizophrenia and depression observed with magnetic resonance spectroscopy at 7 T

    Science.gov (United States)

    Osuch, Elizabeth A.; Schaefer, Betsy; Rajakumar, Nagalingam; Neufeld, Richard W. J.; Théberge, Jean; Williamson, Peter C.

    2017-01-01

    Background Examining neurometabolic abnormalities in critical brain areas in schizophrenia and major depressive disorder (MDD) may help guide future pharmacological interventions including glutamate-modulating treatments. Aims To measure metabolite concentrations within the anterior cingulate cortex (ACC) and thalamus of people with schizophrenia and people with MDD. Methods Spectra were acquired from 16 volunteers with schizophrenia, 17 with MDD and 18 healthy controls using magnetic resonance spectroscopy on a 7 Tesla scanner. Results In the thalamus, there were lower glycine concentrations in the schizophrenia group relative to control (P=0.017) and MDD groups (P=0.012), and higher glutamine concentrations relative to healthy controls (P=0.009). In the thalamus and the ACC, the MDD group had lower myo-inositol concentrations than the control (P=0.014, P=0.009, respectively) and schizophrenia (P=0.004, P=0.002, respectively) groups. Conclusion These results support the glutamatergic theory of schizophrenia and indicate a potential glycine deficiency in the thalamus. In addition, reduced myo-inositol concentrations in MDD suggest its involvement in the disorder. Declaration of interest None. Copyright and usage © The Royal College of Psychiatrists 2017. This is an open access article distributed under the terms of the Creative Commons Non-Commercial, No Derivatives (CC BY-NC-ND) license.

  1. 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)

  2. 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.

  3. Application of electrochemical surface plasmon resonance spectroscopy for characterization of electrochemical DNA sensors.

    Science.gov (United States)

    Salamifar, S Ehsan; Lai, Rebecca Y

    2014-10-01

    We report the use of electrochemical surface plasmon resonance spectroscopy (EC-SPR) in the characterization of electrochemical DNA sensors. Three DNA probes, including a stem-loop probe and two linear probes (LP), were used in this study. Among the three sensors, the 3xLP sensor, a new sensor design with three consecutive target recognition sites, showed the largest change in SPR signal upon hybridization to T-25, a 25-base target with overhang regions that do not bind to the 3xLP probe. A detection limit of 20nM was determined for T-25 using this sensor. Overall, this work has demonstrated the main advantage of EC-SPR, which is the ability to monitor both optical and electrochemical signals simultaneously, from sensor fabrication to target interrogation and sensor regeneration. It also alludes to the potential use of this hybrid technique to differentiate between non-specific binding and non-specific adsorption of non-complement targets onto the sensor surface.

  4. Optical pathology study of human abdominal aorta tissues using confocal micro resonance Raman spectroscopy

    Science.gov (United States)

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

    2016-03-01

    Resonance Raman (RR) spectroscopic technique has a high potential for label-free and in-situ detection of biomedical lesions in vivo. This study evaluates the ability of RR spectroscopy method as an optical histopathology tool to detect the atherosclerotic plaque states of abdominal aorta in vitro. This part demonstrates the RR spectral molecular fingerprint features from different sites of the atherosclerotic abdominal aortic wall tissues. Total 57 sites of five pieces aortic samples in intimal and adventitial wall from an autopsy specimen were examined using confocal micro Raman system of WITec 300R with excitation wavelength of 532nm. The preliminary RR spectral biomarkers of molecular fingerprints indicated that typical calcified atherosclerotic plaque (RR peak at 964cm-1) tissue; fibrolipid plaque (RR peaks at 1007, 1161, 1517 and 2888cm-1) tissue, lipid pool with the fatty precipitation cholesterol) with collagen type I (RR peaks at 864, 1452, 1658, 2888 and 2948cm-1) in the soft tissue were observed and investigated.

  5. Assessment of diabetic neuropathy with emission tomography and magnetic resonance spectroscopy.

    Science.gov (United States)

    Rao, Harshvardhan; Gaur, Neeraj; Tipre, Dnyanesh

    2017-04-01

    Diabetic neuropathies (DNs) are nerve-damaging disorders associated with diabetes. They are commonly attributed to peripheral nerves and primarily affect the limbs of the patient. They cause altered sensitivity to external stimuli along with loss in balance and reflexes of the affected patient. DNs are associated with a variety of clinical manifestations including autonomic failure and are caused by poor management of blood sugar levels. Imaging modalities provide vital information about early physiological changes in DNs. This review summarizes contributions by various teams of scientists in developing imaging methods to assess physiological changes in DNs and ongoing clinical trials where imaging modalities are applied to evaluate therapeutic intervention in DNs. Development of PET, single photon emission computed tomography, and magnetic resonance spectroscopy methods over the past 20 years are reviewed in the diagnostic assessment of DNs. Abnormal radiotracer pharmacokinetics and neurometabolite spectra in affected organs confirm physiological abnormalities in DN. With the use of the Siemens Biograph mMR and GE Signa - 60 cm (PET/MRI scanner), simultaneous acquisition of physiological and anatomical information could enhance understanding of DNs and accelerate drug development.

  6. Monitoring the temperature-dependent elastic and anelastic properties in isotropic polycrystalline ice using resonant ultrasound spectroscopy

    Science.gov (United States)

    Vaughan, Matthew J.; van Wijk, Kasper; Prior, David J.; Hamish Bowman, M.

    2016-11-01

    The elastic and anelastic properties of ice are of interest in the study of the dynamics of sea ice, glaciers, and ice sheets. Resonant ultrasound spectroscopy allows quantitative estimates of these properties and aids 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).

  7. 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.

  8. An optic fiber sensor for multiple gases based on fiber loop ring-down spectroscopy and microring resonator arrays

    Science.gov (United States)

    Zhang, Xin; Jian, Jia-wen; Zheng, Yan-gong; Jin, Han; Zou, Jie

    2016-07-01

    A high-sensitivity sensor for multiple gases based on microring array filter and fiber loop ring-down spectroscopy system is proposed and demonstrated. The parameters of the resonators are designed so that the filtered signal from a broadband light source can be tuned with an absorption spectral line of gas. Therefore, through adding microring resonators horizontally and vertically, the number of target gases and filter range are increased. In this research, in the broad spectral range of about 0.9 μm, only the absorption spectral lines of target gases are filtered. The simulation results show that three target gases, CH4, CO2 and HF, can be simultaneously detected by the sensing system. Owing to the fiber loop ring-down spectroscopy, the whole system is optimized in mini-size and sensitivity, and we can choose different sensing methods to enhance the measurement accuracy for high and low concentration conditions.

  9. A dual-mode microwave resonator for double electron-electron spin resonance spectroscopy at W-band microwave frequencies

    Science.gov (United States)

    Tkach, Igor; Sicoli, Giuseppe; Höbartner, Claudia; Bennati, Marina

    2011-04-01

    We present a dual-mode resonator operating at/near 94 GHz (W-band) microwave frequencies and supporting two microwave modes with the same field polarization at the sample position. Numerical analysis shows that the frequencies of both modes as well as their frequency separation can be tuned in a broad range up to GHz. The resonator was constructed to perform pulsed ELDOR experiments with a variable separation of "pump" and "detection" frequencies up to Δ ν = 350 MHz. To examine its performance, test ESE/PELDOR experiments were performed on a representative biradical system.

  10. Muscle fat content and abdominal adipose tissue distribution investigated by magnetic resonance spectroscopy and imaging in obese children and youths

    DEFF Research Database (Denmark)

    Fonvig, Cilius E; Bille, Dorthe S; Chabanova, Elizaveta

    2012-01-01

    The degree of fat deposition in muscle and its implications for obesity-related complications in children and youths are not well understood. One hundred and fifty-nine patients (mean age: 13.3 years; range: 6-20) with a body mass index (BMI) >90(th) percentile for age and sex were included. Muscle...... fat content (MFC) was measured in the psoas muscle by proton magnetic resonance spectroscopy. The patients were assigned to two groups: MFC...

  11. Near-infrared single-photon spectroscopy of a whispering gallery mode resonator using energy-resolving transition edge sensors

    CERN Document Server

    Förtsch, Michael; Stevens, Martin J; Strekalov, Dmitry; Schunk, Gerhard; Fürst, Josef U; Vogl, Ulrich; Sedlmeir, Florian; Schwefel, Harald G L; Leuchs, Gerd; Nam, Sae Woo; Marquardt, Christoph

    2014-01-01

    We demonstrate a method to perform spectroscopy of near-infrared single photons without the need of dispersive elements. This method is based on a photon energy resolving transition edge sensor and is applied for the characterization of widely wavelength tunable narrow-band single photons emitted from a crystalline whispering gallery mode resonator. We measure the emission wavelength of the generated signal and idler photons with an uncertainty of up to 2 nm.

  12. Metabolic abnormalities in skeletal muscle of patients receiving zidovudine therapy observed by 31P in vivo magnetic resonance spectroscopy.

    OpenAIRE

    Sinnwell, T M; Sivakumar, K.; Soueidan, S; Jay, C; Frank, J.A.; McLaughlin, A C; Dalakas, M C

    1995-01-01

    Patients on long-term zidovudine (AZT) therapy experience muscle fatigue and weakness attributed to AZT-induced mitochondrial toxicity in skeletal muscle. To determine if the clinico-pathological abnormalities in these patients correspond to abnormal muscle energy metabolism, we used 31P in vivo magnetic resonance spectroscopy to follow phosphorylated metabolites during exercise. We studied 19 normal volunteers, 6 HIV-positive patients never treated with AZT, and 9 HIV-positive patients who h...

  13. Optical spectroscopy of single Si nanocylinders with magnetic and electric resonances

    DEFF Research Database (Denmark)

    Evlyukhin, A. B.; Eriksen, R. L.; Cheng, W.

    2014-01-01

    Resonant electromagnetic properties of nanoparticles fabricated from high-index semiconductor or dielectric materials are very promising for the realization of novel nanoantennas and metamaterials. In this paper we study optical resonances of Si nanocylinders located on a silica substrate...

  14. Detection of reactive oxygen species in isolated, perfused lungs by electron spin resonance spectroscopy

    Science.gov (United States)

    Weissmann, Norbert; Kuzkaya, Nermin; Fuchs, Beate; Tiyerili, Vedat; Schäfer, Rolf U; Schütte, Hartwig; Ghofrani, Hossein A; Schermuly, Ralph T; Schudt, Christian; Sydykov, Akylbek; Egemnazarow, Bakytbek; Seeger, Werner; Grimminger, Friedrich

    2005-01-01

    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 demonstrate that 1) PMA

  15. 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

  16. Phase modulation spectroscopy of space-charge wave resonances in Bi12SiO20

    DEFF Research Database (Denmark)

    Vasnetsov, M.; Buchhave, Preben; Lyuksyutov, S.

    1997-01-01

    A new experimental method for the study of resonance effects and space-charge wave excitation in photorefractive Bi12SiO20 crystals by using a combination of frequency detuning and phase modulation technique has been developed. The accuracy of the method allows a detection of resonance peaks...... and revealed its resonance dependence. A minimum of electric current through the sample corresponds to the main resonance detected by phase modulation technique....

  17. 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...

  18. 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

  19. 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.

  20. 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)

  1. 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.

  2. 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.

  3. 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

  4. Investigation of brain injury using in vivo multinuclear magnetic resonance imaging and spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Chew, W.M.

    1989-01-01

    Magnetic Resonance Imaging (MRI) and Spectroscopy (MRS) are becoming increasingly important tools to the fields of biochemistry, physiology, and medicine. MRI and MRS studies offer one the opportunity to obtain anatomic images and biochemical information non-invasively and non-destructively, thus making serial repeated measurements possible on the same experimental subject. To investigate brain injury, the non-invasiveness finally allows one to follow the time course of evolution of injury and its effects on the brains metabolism. Although MRI and MRS offer exciting opportunities, much work is needed to overcome the initial problems of signal localization from a specified region of interest. Also, the potential utility of multinuclear (i.e. {sup 13}C, {sup 19}F, {sup 23}Na...) MRI and MRS studies, in assessing brain injury, is yet to be determined. This thesis attacks the aforementioned problems with a series of studies both on phantoms and in vivo. Experiments were performed to determine optimal localization schemes for use in MRS of the brain to overcome the initial problems encountered with MRS studies. The feasibility and utility of multinuclear MRI and MRS was determined in vivo involving {sup 13}C, {sup 19}F, and {sup 23}Na nuclei. The results of these studies have proven that acceptable signal localization for MRS studies is achievable and is not a hindrance for future MRS studies. Also, multinuclear studies have shown that it is feasible to obtain MRI or MRS data from less abundant nuclei and that the information obtained does or can provide useful insights into brain metabolism in pathologic states.

  5. {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.

  6. 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)

  7. 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.)

  8. 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.

  9. Change in brain magnetic resonance spectroscopy after treatment during acute HIV infection.

    Directory of Open Access Journals (Sweden)

    Napapon Sailasuta

    Full Text Available OBJECTIVE: 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. METHODS: 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. RESULTS: 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. INTERPRETATION: 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.

  10. 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.

  11. Maintenance of high-energy brain phosphorous compounds during insulin-induced hypoglycemia in men. 31P nuclear magnetic resonance spectroscopy study

    DEFF Research Database (Denmark)

    Hilsted, Jannik; Jensen, K E; Thomsen, C;

    1988-01-01

    31P nuclear magnetic resonance (NMR) spectroscopy allows noninvasive studies of cerebral energy-rich phosphorous compounds in humans. In an attempt to characterize the relationship between peripheral blood glucose concentrations and whole-brain phosphate metabolism during insulin...

  12. 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...

  13. 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.

  14. Chromatographic and spectroscopic analysis of heavy crude oil mixtures with emphasis in nuclear magnetic resonance spectroscopy: A review

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Sandra L. [Department of Chemistry, QOPNA, University of Aveiro, Campus de Santiago, 3810-193 Aveiro (Portugal); Silva, Artur M.S., E-mail: artur.silva@ua.pt [Department of Chemistry, QOPNA, University of Aveiro, Campus de Santiago, 3810-193 Aveiro (Portugal); Ribeiro, Jorge C. [Petrogal SA, Laboratory of Matosinhos Refinery, Rua Belchior Robles, 4452-852 Leca da Palmeira, Matosinhos (Portugal); Martins, Fernando G. [LEPAE, University of Porto, Engineering Faculty, Department of Chemical Engineering, Rua Dr. Roberto Frias, 4200-465 Porto (Portugal); Da Silva, Francisco A.; Silva, Carlos M. [Department of Chemistry, CICECO, University of Aveiro, Campus de Santiago, 3810-193 Aveiro (Portugal)

    2011-11-30

    Graphical abstract: The chromatographic and spectroscopic techniques used to characterize heavy crude oils, although more focused in the nuclear magnetic resonance spectroscopy as the technique of choice, due to its capability to provide great information on the chemical nature of individual types of proton and carbon atoms in different and complex mixtures of crude oils are described. This review is based on 65 references and describes in a critical and interpretative ways the advantages of the NMR spectroscopy as a main technique to be used in crude oil refining industries that want to characterize crude oil fractions and the obtained refined products. Highlights: Black-Right-Pointing-Pointer Chromatogrfaphic and spectroscopic techniques used to characterize heavy crude oils have been reviewed. Black-Right-Pointing-Pointer This review describes in a critical and interpretative ways the advantages of the NMR spectroscopy as a main technique to be used in crude oil refining industries. Black-Right-Pointing-Pointer The progress in the interpretation of the NMR spectra and of different multivariate data analyses and their potential in the identification and characterization of hydrocarbons and their physical and chemical properties have also been reviewed. - Abstract: The state of the art in the characterization of heavy crude oil mixtures is presented. This characterization can be done by different techniques, such as gas chromatography (GC), high performance liquid chromatography (HPLC), thin layer chromatography (TLC), infrared spectroscopy (IR), Raman spectroscopy, nuclear magnetic resonance (NMR) spectroscopy and mass spectrometry (MS). Nuclear magnetic resonance spectroscopy is the technique of choice due to its capability to provide information on the chemical nature of individual types of hydrogen and carbon atoms in different and complex mixtures of crude oils. The progress made in the interpretation of the NMR spectra with the development of new NMR

  15. 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).

  16. Electron-volt spectroscopy at a pulsed neutron source using a resonance detector technique

    CERN Document Server

    Andreani, C; Senesi, R; Gorini, G; Tardocchi, M; Bracco, A; Rhodes, N; Schooneveld, E M

    2002-01-01

    The effectiveness of the neutron resonance detector spectrometer for deep inelastic neutron scattering measurements has been assessed by measuring the Pb scattering on the eVS spectrometer at ISIS pulsed neutron source and natural U foils as (n,gamma) resonance converters. A conventional NaI scintillator with massive shielding has been used as gamma detector. A neutron energy window up to 90 eV, including four distinct resonance peaks, has been assessed. A net decrease of the intrinsic width of the 6.6 eV resonance peak has also been demonstrated employing the double difference spectrum technique, with two uranium foils of different thickness.

  17. 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…

  18. Studying lipid-protein interactions with electron paramagnetic resonance spectroscopy of spin-labeled lipids.

    Science.gov (United States)

    Páli, Tibor; Kóta, Zoltán

    2013-01-01

    Spin label electron paramagnetic resonance (EPR) of lipid-protein interactions reveals crucial features of the structure and assembly of integral membrane proteins. Spin label EPR spectroscopy is the technique of choice to characterize the protein-solvating lipid shell in its highly dynamic nature, because the EPR spectra of lipids that are spin labeled close to the terminal methyl end of their acyl chains display two spectral components, those corresponding to lipids directly contacting the protein and those corresponding to lipids in the bulk fluid bilayer regions of the membrane. In this chapter, typical spin label EPR procedures are presented that allow determination of the stoichiometry of interaction of spin-labeled lipids with the intra-membranous region of membrane proteins or polypeptides, as well as the association constant of the spin-labeled lipid with respect to the host lipid. The lipids giving rise to the so-called immobile spectral component in the EPR spectrum of such samples are identified as the motionally restricted first-shell lipids solvating membrane proteins in biomembranes. Stoichiometry and selectivity are directly related to the structure of the intra-membranous sections of membrane-associated proteins or polypeptides and can be used to study the state of assembly of such proteins in the membrane. Since these characteristics of lipid-protein interactions are discussed in detail in the literature [see Marsh (Eur Biophys J 39:513-525, 2010) for a most recent review], here we focus more on how to spin label model and biomembranes and how to measure and analyze the two-component EPR spectra of spin-labeled lipids in phospholipid bilayers that contain proteins or polypeptides. After a description of how to prepare spin-labeled model and native biological membranes, we present the reader with computational procedures for determining the molar fraction of motionally restricted lipids when both, one, or none of the pure isolated-mobile or

  19. Differences between spinocerebellar ataxias and multiple system atrophy-cerebellar type on proton magnetic resonance spectroscopy.

    Directory of Open Access Journals (Sweden)

    Jiing-Feng Lirng

    Full Text Available PURPOSE: A broad spectrum of diseases can manifest cerebellar ataxia. In this study, we investigated whether proton magnetic resonance spectroscopy (MRS may help differentiate spinocerebellar ataxias (SCA from multiple systemic atrophy- cerebellar type (MSA-C. MATERIAL AND METHODS: This prospective study recruited 156 patients with ataxia, including spinocerebellar ataxia (SCA types 1, 2, 3, 6 and 17 (N = 94 and MSA-C (N = 62, and 44 healthy controls. Single voxel proton MRS in the cerebellar hemispheres and vermis were measured. The differences were evaluated using nonparametric statistic tests. RESULTS: When compared with healthy controls, the cerebellar and vermis NAA/Cr and NAA/Cho were lower in all patients(p<0.002. The Cho/Cr was lower in SCA2 and MSA-C (p<0.0005. The NAA/Cr and Cho/Cr were lower in MSA-C or SCA2 comparing with SCA3 or SCA6. The MRS features of SCA1 were in between (p<0.018. The cerebellar NAA/Cho was lower in SCA2 than SCA1, SCA3 or SCA6 (p<0.04. The cerebellar NAA/Cho in MSA-C was lower than SCA3 (p<0.0005. In the early stages of diseases (SARA score<10, significant lower NAA/Cr and NAA/Cho in SCA2, SCA3, SCA6 or MSA-C were observed comparing with healthy controls (p<0.017. The Cho/Cr was lower in MSA-C or SCA2 (p<0.0005. Patients with MSA-C and SCA2 had lower NAA/Cr and Cho/Cr than SCA3 or SCA6 (p<0.016. CONCLUSION: By using MRS, significantly lower NAA/Cr, Cho/Cr and NAA/Cho in the cerebellar hemispheres and vermis were found in patients with ataxia (SCAs and MSA-C. Rapid neuronal degeneration and impairment of membrane activities were observed more often in patients with MSA-C than those with SCA, even in early stages. MRS could also help distinguish between SCA2 and other subtypes of SCAs. MRS ratios may be of use as biomarkers in early stages of disease and should be further assessed in a longitudinal study.

  20. Proton magnetic resonance spectroscopy of normal human brain and glioma:a quantitive in vivo study

    Institute of Scientific and Technical Information of China (English)

    TONG Zhi-yong; YAMAKI Toshiaki; WANG Yun-jie

    2005-01-01

    Background In vivo proton magnetic resonance spectroscopy (MRS) provides a noninvasive method of examining a wide variety of cerebral metabolites in both healthy subjects and patients with various brain diseases.Absolute metabolite concentrations have been determined using external and internal standards with known concentrations.When an external standard is placed beside the head, variations in signal amplitudes due to B1 field inhomogeneity and static field inhomogeneity may occur.Hence an internal standard is preferable.The purpose of this study was to quantitatively analyze the metabolite concentrations in normal adult brains and gliomas by in vivo proton MRS using the fully relaxed water signal as an internal standard.Methods Between January 1998 and October 2001, 28 healthy volunteers and 16 patients with gliomas were examined by in vivo proton MRS.Single-voxel spectra were acquired using the point-resolved spectroscopic pulse sequence with a 1.5 T scanner (TR/TE/Ave=3000 ms/30 ms/64).Results The calculated concentrations of N-acetyl-asparatate (NAA), creatine (Cre), choline (Cho), and water (H2O) in the normal hemispheric white matter were (23.59±2.62) mmol/L, (13.06±1.8) mmol/L, (4.28±0.8) mmol/L, and (47 280.96±5414.85) mmol/L, respectively.The metabolite concentrations were not necessarily uniform in different parts of the brain.The concentrations of NAA and Cre decreased in all gliomas (P<0.001).The ratios of NAA/Cho and NAA/H2O showed a significant difference between the normal brain and gliomas, and also between the high and low grades (P<0.001).Conclusions Quantitative analysis of in vivo proton MR spectra using the fully relaxed water signal as an internal standard is useful.The concentrations of NAA and the ratios of NAA/H2O and NAA/Cho conduce to discriminating between the glioma and normal brain, and also between the low-grade glioma and high-grade glioma.

  1. Bone marrow fat is increased in chronic kidney disease by magnetic resonance spectroscopy

    Science.gov (United States)

    Fadel, W.; Eckert, G. J.; Ponsler-Sipes, K.; Moe, S. M.; Lin, C.

    2015-01-01

    Summary In aging, the bone marrow fills with fat and this may lead to higher fracture risk. We show that a bone marrow fat measurement by magnetic resonance spectroscopy (MRS), a newer technique not previously studied in chronic kidney disease (CKD), is useful and reproducible. CKD patients have significantly higher bone marrow fat than healthy adults. Introduction Renal osteodystrophy leads to increased morbidity and mortality in patients with CKD. Traditional bone biopsy histomorphometry is used to study abnormalities in CKD, but the bone marrow, the source of osteoblasts, has not been well characterized in patients with CKD. Methods To determine the repeatability of bone marrow fat fraction assessment by MRS and water-fat imaging (WFI) at four sites in patients with CKD, testing was performed to determine the coefficients of reproducibility and intraclass coefficients (ICCs). We further determined if this noninvasive technique could be used to determine if there are differences in the percent bone marrow fat in patients with CKD compared to matched controls using paired t tests. Results The mean age of subjects with CKD was 59.8±7.2 years, and the mean eGFR was 24±8 ml/min. MRS showed good reproducibility at all sites in subjects with CKD and controls, with a coefficient of reproducibilities ranging from 2.4 to 13 %. MRS and WFI assessment of bone marrow fat showed moderate to strong agreement (ICC 0.6–0.7) at the lumbar spine, with poorer agreement at the iliac crest and no agreement at the tibia. The mean percent bone marrow fat at L2–L4 was 13.8 % (95 % CI 8.3–19.7) higher in CKD versus controls (p<0.05). Conclusions MRS is a useful and reproducible technique to study bone marrow fat in CKD. Patients with CKD have significantly higher bone marrow fat than healthy adults; the relationship with bone changes requires further analyses. PMID:25701052

  2. 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...

  3. 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.

  4. 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)

  5. Active Plasma Resonance Spectroscopy: Evaluation of a fluiddynamic-model of the planar multipole resonance probe using functional analytic methods

    Science.gov (United States)

    Friedrichs, Michael; Brinkmann, Ralf Peter; Oberrath, Jens

    2016-09-01

    Measuring plasma parameters, e.g. electron density and electron temperature, is an important procedure to verify the stability and behavior of a plasma process. For this purpose the multipole resonance probe (MRP) represents a satisfying solution to measure the electron density. However the influence of the probe on the plasma through its physical presence makes it unattractive for some processes in industrial application. A solution to combine the benefits of the spherical MRP with the ability to integrate the probe into the plasma reactor is introduced by the planar model of the MRP. By coupling the model of the cold plasma with the maxwell equations for electrostatics an analytical model for the admittance of the plasma is derivated, adjusted to cylindrical geometry and solved analytically for the planar MRP using functional analytic methods.

  6. 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.

  7. Applications of magnetic resonance spectroscopy for noninvasive assessment of hepatic steatosis

    NARCIS (Netherlands)

    J.R. van Werven

    2011-01-01

    MR spectroscopy is a noninvasive technique to quantify hepatic steatosis. MR spectroscopy provides information about the chemical composition of tissues in a spectrum. Hepatic steatosis is characterized by accumulation of fat in the liver. The prevalence of hepatic steatosis is increasing due to its

  8. Characterization of prostate cancer, benign prostatic hyperplasia and normal prostates using transrectal 31phosphorus magnetic resonance spectroscopy: a preliminary report

    Energy Technology Data Exchange (ETDEWEB)

    Narayan, P.; Jajodia, P.; Kurhanewicz, J.; Thomas, A.; MacDonald, J.; Hubesch, B.; Hedgcock, M.; Anderson, C.M.; James, T.L.; Tanagho, E.A. (Univ. of California School of Medicine, San Francisco (USA))

    1991-07-01

    We assessed the ability of 31phosphorus (31P) transrectal magnetic resonance spectroscopy to characterize normal human prostates as well as prostates with benign and malignant neoplasms. With a transrectal probe that we devised for surface coil spectroscopy we studied 15 individuals with normal (5), benign hyperplastic (4) and malignant (6) prostates. Digital rectal examination, transrectal ultrasonography and magnetic resonance imaging were used to aid in accurate positioning of the transrectal probe against the region of interest within the prostate. The major findings of the in vivo studies were that normal prostates had phosphocreatine-to-adenosine triphosphate (ATP) ratios of 1.2 +/- 0.2, phosphomonoester-to-beta-ATP ratios of 1.1 +/- 0.1 and phosphomonoester-to-phosphocreatine ratios of 0.9 +/- 0.1. Malignant prostates had phosphocreatine-to-beta-ATP ratios that were lower (0.7 +/- 0.1) than those of normal prostates (p less than 0.02) or prostates with benign hyperplasia. Malignant prostates had phosphomonoester-to-beta-ATP ratios (1.8 +/- 0.2) that were higher than that of normal prostates (p less than 0.02). Using the phosphomonoester-to-phosphocreatine ratio, it was possible to differentiate metabolically malignant (2.7 +/- 0.3) from normal prostates (p less than 0.001), with no overlap of individual ratios. The mean phosphomonoester-to-phosphocreatine ratio (1.5 +/- 0.5) of prostates with benign hyperplasia was midway between the normal and malignant ratios, and there was overlap between individual phosphomonoester-to-phosphocreatine ratios of benign prostatic hyperplasia glands with that of normal and malignant glands. To verify the in vivo results, we performed high resolution magnetic resonance spectroscopy on perchloric acid extracts of benign prostatic hyperplasia tissue obtained at operation and on a human prostatic cancer cell line DU145.

  9. Electronic properties of atomic layer deposition films, anatase and rutile TiO2 studied by resonant photoemission spectroscopy

    Science.gov (United States)

    Das, C.; Richter, M.; Tallarida, M.; Schmeisser, D.

    2016-07-01

    The TiO2 films are prepared by atomic layer deposition (ALD) method using titanium isopropoxide precursors at 250 °C and analyzed using resonant photoemission spectroscopy (resPES). We report on the Ti2p and O1s core levels, on the valence band (VB) spectra and x-ray absorption spectroscopy (XAS) data, and on the resonant photoelectron spectroscopy (resPES) profiles at the O1s and the Ti3p absorption edges. We determine the elemental abundance, the position of the VB maxima, the partial density of states (PDOS) in the VB and in the conduction band (CB) and collect these data in a band scheme. In addition, we analyze the band-gap states as well as the intrinsic states due to polarons and charge-transfer excitations. These states are found to cause multiple Auger decay processes upon resonant excitation. We identify several of these processes and determine their relative contribution to the Auger signal quantitatively. As our resPES data allow a quantitative analysis of these defect states, we determine the relative abundance of the PDOS in the VB and in CB and also the charge neutrality level. The anatase and rutile polymorphs of TiO2 are analyzed in the same way as the TiO2 ALD layer. The electronic properties of the TiO2 ALD layer are compared with the anatase and rutile polymorphs of TiO2. In our comparative study, we find that ALD has its own characteristic electronic structure that is distinct from that of anatase and rutile. However, many details of the electronic structure are comparable and we benefit from our spectroscopic data and our careful analysis to find these differences. These can be attributed to a stronger hybridization of the O2p and Ti3d4s states for the ALD films when compared to the anatase and rutile polymorphs.

  10. Nanocrystalline tin oxide: Possible origin of its weak ferromagnetism deduced from nuclear magnetic resonance and X-ray photoelectron spectroscopies

    Science.gov (United States)

    Zhang, Feng; Lian, Yadong; Gu, Min; Yu, Ji; Tang, Tong B.; Sun, Jian; Zhang, Weiyi

    2016-09-01

    Nanocrystalline tin oxide was fabricated, with molar ratio O/Sn determined as 1.40, 1.55, 1.79, 1.92 and 1.96 from X-ray photoelectron spectroscopy. They displayed weak ferromagnetism, the sample with O/Sn = 1.55 showing the maximum saturation magnetization reaching almost 8 ×10-3 emu /g at room temperature. 119Sn nuclear magnetic resonance allowed the deduction, based on four resolved resonance peaks, that their Sn ions had four possible coordination numbers, namely 3, 4, 5 and 6. The relative fraction of 4-coordinated cations was the one found to bear positive linear correlation with saturation magnetization of the sample. It is surmised that magnetism in tin oxide results mainly from 4-coordination Sn ions, of valance about +3, as estimated from the binding energies of their 3d photoelectron emission levels.

  11. Fast high-resolution nuclear magnetic resonance spectroscopy through indirect zero-quantum coherence detection in inhomogeneous fields

    Science.gov (United States)

    Ke, Han-Ping; Chen, Hao; Lin, Yan-Qin; Wei, Zhi-Liang; Cai, Shu-Hui; Zhang, Zhi-Yong; Chen, Zhong

    2014-06-01

    In many cases, high-resolution nuclear magnetic resonance (NMR) spectra are virtually impossible to obtain by conventional nuclear magnetic resonance methods because of inhomogeneity of magnetic field and inherent heterogeneity of sample. Although conventional intramolecular zero-quantum coherence (ZQC) can be used to obtain high-resolution spectrum in inhomogeneous field, the acquisition takes rather long time. In this paper, a spatially encoded intramolecular ZQC technique is proposed to fast acquire high-resolution NMR spectrum in inhomogeneous field. For the first time, the gradient-driven decoding technique is employed to selectively acquire intramolecular ZQC signals. Theoretical analyses and experimental observations demonstrate that high-resolution NMR spectral information can be retrieved within several scans even when the field inhomogeneity is severe enough to erase most spectral information. This work provides a new way to enhance the acquisition efficiency of high-resolution intramolecular ZQC spectroscopy in inhomogeneous fields.

  12. 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.

  13. Proton magnetic resonance spectroscopy of the anterior cingulate gyrus and caudate nucleus in schizophrenia patients versus healthy controls

    Institute of Scientific and Technical Information of China (English)

    Lutfi Incesu; Meral Baydin; Kerim Aslan; Baris Diren; Huseyin Sahin; Omer Boke; Senol Dane

    2011-01-01

    Proton magnetic resonance spectroscopy (1H-MRS) permits the assessment of cerebral neurometabolites, such as N-acetylaspartate, choline, and creatine, in vivo and has been used to study schizophrenia. The present study used 1H-MRS to compare the spectroscopy change of N-acetylaspartate, creatine, and choline metabolite levels in the anterior cingulate and caudate nucleus of both schizophrenia patients and healthy controls, as well as between the left and right cerebral hemispheres in the schizophrenia patients. Results showed that N-acetylaspartate and creatine metabolite levels in the left anterior cingulate gyrus were significantly lower in the schizophrenia patients than in the healthy controls, indicating hypometabolism. In addition, choline concentration in the left caudate nucleus of schizophrenia patients was significantly lower than in the right caudate nucleus, indicating that it is necessary to study the cerebral lateralization of 1H-MRS in schizophrenia patients.

  14. Partial-Homogeneity-Based Two-Dimensional High-Resolution Nuclear Magnetic Resonance Spectroscopy under Inhomogeneous Magnetic Fields.

    Science.gov (United States)

    Qiu, Wenqi; Wei, Zhiliang; Ding, Nan; Yang, Yu; Ye, Qimiao; Lin, Yulan; Chen, Zhong

    2016-05-18

    High-resolution multidimensional nuclear magnetic resonance (NMR) spectroscopy serves as an irreplaceable and versatile tool in various chemical investigations. In this study, a method based on the concept of partial homogeneity is developed to offer two-dimensional (2D) high-resolution NMR spectra under inhomogeneous fields. Oscillating gradients are exerted to encode the high-resolution information, and a field-inhomogeneity correction algorithm based on pattern recognition is designed to recover high-resolution spectra. Under fields where inhomogeneity primarily distributes along a single orientation, the proposed method will improve performances of 2D NMR spectroscopy without increasing the experimental duration or significant loss in sensitivity, and thus may open important perspectives for studies of inhomogeneous chemical systems.

  15. Exploring Structure, Dynamics, and Topology of Nitroxide Spin-Labeled Proteins Using Continuous-Wave Electron Paramagnetic Resonance Spectroscopy.

    Science.gov (United States)

    Altenbach, Christian; López, Carlos J; Hideg, Kálmán; Hubbell, Wayne L

    2015-01-01

    Structural and dynamical characterization of proteins is of central importance in understanding the mechanisms underlying their biological functions. Site-directed spin labeling (SDSL) combined with continuous-wave electron paramagnetic resonance (CW EPR) spectroscopy has shown the capability of providing this information with site-specific resolution under physiological conditions for proteins of any degree of complexity, including those associated with membranes. This chapter introduces methods commonly employed for SDSL and describes selected CW EPR-based methods that can be applied to (1) map secondary and tertiary protein structure, (2) determine membrane protein topology, (3) measure protein backbone flexibility, and (4) reveal the existence of conformational exchange at equilibrium.

  16. 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......-PDGF mice, when compared to normal brain tissue in the control mice. CONCLUSIONS: Metabolic profiling using 1HMRS in combination with LCModel analysis did not reveal correlation between Lip13a+Lip13b spectral signatures and an increase in neurogenesis in adult rat hippocampus after ECS. However, increases...

  17. 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).

  18. Resonance Raman kinetic spectroscopy of bacteriorhodopsin on the microsecond time scale

    Energy Technology Data Exchange (ETDEWEB)

    Campion, A.; El-Sayed, M.A.; Terner, J.

    1977-12-01

    Using a rotating disk with a slit of variable width, a continuous wave argon ion laser, and an Optical Multichanel Analyzer for detection, a new technique is reported which should, in principle, be capable of recording resonance Raman spectra with time resolution of 100 ns. The resonance Raman spectra of the intermediates of the photosynthetic cycle of bacteriorhodopsin are recorded on the microsecond time scale. Both the kinetic results and the resonance enhancement profile suggest that deprotonation results in an intermediate preceding bM/sub 412/ that has an optical absorption maximum at a wavelength longer than that of bM/sub 412/.

  19. Examination of gamma-irradiated fruits and vegetables by electron spin resonance spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Desrosiers, M.F.; McLaughlin, W.L. (National Inst. of Standards and Technology (NML), Gaithersburg, MD (USA). Center for Radiation Research)

    1989-01-01

    The ESR spectra of the seeds, pits, shells, and skins of a variety of irradiated fruits and vegetables were measured. All spectra, control and irradiated, contained a single resonance with a g-factor of 2.00. Additional resonances due to Mn{sup 2+} were observed for the drupelets of blackberries and red raspberries. An unusual radiation-induced radical was observed for irradiated mango seed; however, the signal decayed completely within a few days. It was concluded that only in a few specialized cases could the ESR resonances observed be suitable for postirradiation monitoring or dosimetry. (author).

  20. Examination of gamma-irradiated fruits and vegetables by electron spin resonance spectroscopy

    Science.gov (United States)

    Desrosiers, Marc F.; McLaughlin, William L.

    The ESR spectra of the seeds, pits, shells, and skins of a variety of irradiated fruits and vegetables were measured. All spectra, control and irradiated, contained a single resonance with a g-factor of 2.00. Additional resonances due to Mn 2+ were observed for the drupelets of blackberries and red raspberries. An unusual radiation-induced radical was observed for irradiated mango seed; however, the signal decayed completely within a few days. It was concluded that only in a few specialized cases could the ESR resonances observed be suitable for postirradiation monitoring or dosimetry.

  1. Magnetic-dipolar-mode Fano resonances for microwave spectroscopy of high absorption matter

    CERN Document Server

    Vaisman, G; Shavit, R

    2015-01-01

    Study of interaction between high absorption matter and microwave radiated energy is a subject of great importance. Especially, this concerns microwave spectroscopic characterization of biological liquids. Use of effective testing methods to obtain information about physical properties of different liquids on the molecular level is one of the most important problems in biophysics. However, the standard methods based on the microwave resonant techniques are not sufficiently suitable for biological liquids because the resonance peak in a resonator with high-loss liquids is so broad that the material parameters cannot be measured correctly. Although molecular vibrations of biomolecules may have microwave frequencies, it is not thought that such resonant coupling is significant due to their low energy compared with thermal energy and the strongly dampening aqueous environment. This paper presents an innovative microwave sensing technique for different types of lossy materials, including biological liquids. The te...

  2. Solid State Multinuclear Magnetic Resonance Investigation of Electrolyte Decomposition Products on Lithium Ion Electrodes

    Science.gov (United States)

    DeSilva, J .H. S. R.; Udinwe, V.; Sideris, P. J.; Smart, M. C.; Krause, F. C.; Hwang, C.; Smith, K. A.; Greenbaum, S. G.

    2012-01-01

    Solid electrolyte interphase (SEI) formation in lithium ion cells prepared with advanced electrolytes is investigated by solid state multinuclear (7Li, 19F, 31P) magnetic resonance (NMR) measurements of electrode materials harvested from cycled cells subjected to an accelerated aging protocol. The electrolyte composition is varied to include the addition of fluorinated carbonates and triphenyl phosphate (TPP, a flame retardant). In addition to species associated with LiPF6 decomposition, cathode NMR spectra are characterized by the presence of compounds originating from the TPP additive. Substantial amounts of LiF are observed in the anodes as well as compounds originating from the fluorinated carbonates.

  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. 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)

  5. 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.

  6. 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

  7. Static and dynamic strain coupling behaviour of ferroic and multiferroic perovskites from resonant ultrasound spectroscopy.

    Science.gov (United States)

    Carpenter, M A

    2015-07-08

    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

  8. 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

  9. Resonant soft X-ray emission spectroscopy of vanadium oxides andrelated compounds

    Energy Technology Data Exchange (ETDEWEB)

    Schmitt, Thorsten

    2004-11-01

    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 {micro}m 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

  10. Resonant field enhancement in periodically arranged microslits for non-linear terahertz spectroscopy

    DEFF Research Database (Denmark)

    Pedersen, Pernille Klarskov; Iwaszczuk, Krzysztof; Zalkovskij, Maksim;

    We present a design of periodically arranged microslits in a gold film for nonlinear terahertz phonon spectroscopy.Global optimization of array parameters gives a field enhancement of more than 50, due to plasmonic coupling between individual slits....

  11. Analysis of structure-function relationships in cytochrome c oxidase and its biomimetic analogs via resonance Raman and surface enhanced resonance Raman spectroscopies.

    Science.gov (United States)

    Weidinger, Inez M

    2015-01-01

    Cytochrome c oxidase (CcO) catalyzes the four electron reduction of molecular oxygen to water while avoiding the formation of toxic peroxide; a quality that is of high relevance for the development of oxygen-reducing catalysts. Resonance Raman spectroscopy has been used since many years as a technique to identify electron transfer pathways in cytochrome c oxidase and to identify the key intermediates in the catalytic cycle. This information can be compared to artificial systems such as modified heme-copper enzymes, molecular heme-copper catalysts or CcO/electrode complexes in order to shed light into the reaction mechanism of these non-natural systems. Understanding the structural commonalities and differences of CcO with its non-natural analogs is of great value for designing efficient oxygen-reducing catalysts. In this review therefore Raman spectroscopic measurements on artificial heme-copper enzymes and model complexes are summarized and compared to the natural enzyme cytochrome c oxidase. This article is part of a Special Issue entitled: Vibrational spectroscopies and bioenergetic systems.

  12. Profiling human blood serum metabolites by nuclear magnetic resonance spectroscopy: a comprehensive tool for the evaluation of hemodialysis efficiency.

    Science.gov (United States)

    Kromke, Marika; Palomino-Schätzlein, Martina; Mayer, Horst; Pfeffer, Stefan; Pineda-Lucena, Antonio; Luy, Burkhard; Hausberg, Martin; Muhle-Goll, Claudia

    2016-05-01

    Hemodialysis remains the standard therapy to treat patients affected with end-stage renal disease by removing metabolites accumulated in blood plasma. The efficiency of hemodialysis is mainly monitored by urea clearance, which is routinely checked in clinical laboratory practice. However, there is mounting evidence that the clearance behavior of selected single metabolites is not sufficient to predict long-term outcome of treatment. To address this problem, we evaluated the potential of nuclear magnetic resonance spectroscopy for monitoring hemodialysis efficiency by comprehensive profiling of blood serum metabolites. We carried out a pilot study with a cohort of end-stage chronic kidney disease patients (n = 29), analyzing their serum prior and immediately after hemodialysis. To account for supposed variability in the accumulation of metabolites and efficiency of hemodialysis, patients' blood sera were repeatedly collected over a period of several months. Our results revealed that the metabolic profile in terms of concentrations varied considerably between patients but was comparably constant on the patient's level over the period of 4 months. Interestingly, also the individual clearance of the metabolites was characteristic for each patient. Thus, it is conceivable that the observed patient-dependent clearance patterns reflect to some extent the patients' long-term perspectives. We conclude that nuclear magnetic resonance spectroscopy is an optimal tool to complement traditional clinical methods based on a single variable, providing comprehensive and much more global information, which is crucial for patient evaluation and the development of improved treatments of kidney failure.

  13. 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.

  14. Assessment of bone marrow changes in postmenopausal women with varying bone densities: magnetic resonance spectroscopy and diffusion magnetic resonance imaging

    Institute of Scientific and Technical Information of China (English)

    LIU Yong; TANG Guang-yu; TANG Rong-biao; PENG Yi-feng; LI Wei

    2010-01-01

    Background Recent studies suggest that bone marrow adipose tissue might play a role in the pathogenesis of osteoporosis. There are inconsistent findings on the relationship among marrow fat content, bone mineral density and apparent diffusion coefficient (ADC). This study aimed to prospectively explore the efficacy of MR spectroscopy (MRS)and diffusion-weighted MR imaging (DWI) in detecting vertebral marrow changes in postmenopausal women with varying bone densities.Methods Both MRS and DWI of the lumber spine were performed in 102 postmenopausal women (mean age,(67.3±6.5) years; range, 55-83 years), who underwent dual X-ray absorptiometry. Marrow fat content and ADC were compared and correlated among three groups: 24 with normal bone density, 31 with osteopenia and 47 with osteoporosis.Results Vertebral marrow fat content was significantly increased in the osteoporotic group ((65.60±7.68)%, P <0.001)and the osteopenic group ((57.68±6.45)%, P <0.001), when compared with the normal bone density group ((51.67±3.27)%). ADC values were significantly decreased in the osteoporotic group ((0.39±0.03)×10-3mm2/s, P <0.001)and in the osteopenic group ((0.42±0.02)×10-3mm2/s, P <0.001), when compared with the normal bone density group ((0.47±0.03)×10-3 mm2/s). The marrow fat content negatively correlated with both bone density (r=-0.731, P <0.001)and marrow ADC (r=-0.572, P <0.001). The bone density positively correlated with the ADC values (r=0.802, P<0.001).Conclusions Postmenopausal women experience a corresponding increase in vertebral marrow fat content as the bone density decreases. Marrow fat content and ADC correlate to the bone density. MRS and DWI may indirectly assess the early bone marrow changes in postmenopausal women.

  15. Multi-wavelength resonance Raman spectroscopy of bacteria to study the effects of growth condition

    Science.gov (United States)

    Kunapareddy, Nagapratima; Grun, Jacob; Lunsford, Robert; Gillis, David; Nikitin, Sergei; Wang, Zheng

    2012-06-01

    We will examine the use of multi-wavelength UV resonance-Raman signatures to identify the effects of growth phase on different types of bacteria. Gram positive and gram-negative species, Escherichia coli, Bacillus cereus, Citrobacter koseri and Citrobacter braakii were grown to logarithmic and stationary phases in different culture media. Raman spectra of bacteria were obtained by sequential illumination of samples between 220 and 260 nm; a range which encompasses the resonance frequencies of cellular components. In addition to the information contained in the single spectrum, this two-dimensional signature contains information reflecting variations in resonance cross sections with illumination wavelength. Results of our algorithms in identifying the differences between these germs are discussed. Preliminary results indicate that growth affects the Raman signature, but not to an extent that would negate identification of the species.

  16. Interrogation of fiber Bragg-grating resonators by polarization-spectroscopy laser-frequency locking.

    Science.gov (United States)

    Gagliardi, G; De Nicola, S; Ferraro, P; De Natale, P

    2007-04-02

    We report on an optically-based technique that provides an efficient way to track static and dynamic strain by locking the frequency of a diode laser to a fiber Bragg-grating Fabry-Pérot cavity. For this purpose, a suitable optical frequency discriminator is generated exploiting the fiber natural birefringence and that resulting from the gratings inscription process. In our scheme, a polarization analyzer detects dispersive-shaped signals centered on the cavity resonances without need for additional optical elements in the resonator or any laser-modulation technique. This method prevents degradation of the resonator quality and maintains the configuration relatively simple, demonstrating static and dynamic mechanical sensing below the picostrain level.

  17. Surface-enhanced resonance Raman spectroscopy of copper chlorophyllin on silver and gold colloids

    Energy Technology Data Exchange (ETDEWEB)

    Hildebrandt, P.; Spiro, T.G.

    1988-06-16

    Surface-enhanced resonance Raman spectra (SERRS) are reported for copper chlorophyllin a (CuChl) adsorbed on silver and gold colloids. The surface species are shown to be monomeric, by comparison with solution resonance Raman (RR) spectra, although lowering the pH of the gold colloid to 2.0 induces spectral changes suggestive of surface aggregation. The similarity of CuChl monomer RR and SERRS spectra is consistent with electromagnetic enhancement of the RR spectra via the metal particles, with no indication of a chemical interaction that would perturb the electronic states. The SERRS spectra change markedly with excitation wavelength in ways that can be explained on the basis of the different Raman enhancement pattern expected for resonance with the different chlorin excited states. The SERRS spectra are highly resolved and are useful in suggesting new assignments for chlorin vibrational modes.

  18. Precision spectroscopy with COMPASS and the observation of a new iso-vector resonance

    Science.gov (United States)

    Paul, Stephan

    2014-06-01

    We report on the results of a novel partial-wave analysis based on 50 ṡ 106 events from the reaction π- + p → π-π-π+ + precoil at 190 GeV/c incoming beam momentum using the COMPASS spectrometer. A separated analysis in bins of m3π and four-momentum transfer t' reveals the interference of resonant and non-resonant particle production and allows their spectral separation. Besides well known resonances we observe a new iso-vector meson a1(1420) at a mass of 1420 MeV/c2 in the f0(980)π final state only, the origin of which is unclear. We have also examined the structure of the 0++ππ-isobar in the JPC = 0-+, 1++, 2-+ three pion waves. This clearly reveals the various 0++ππ-isobar components and its correlation to the decay of light mesons.

  19. Elucidating photoinduced structural changes in phytochromes by the combined application of resonance Raman spectroscopy and theoretical methods

    Science.gov (United States)

    Mroginski, M. A.; von Stetten, D.; Kaminski, S.; Escobar, F. Velazquez; Michael, N.; Daminelli-Widany, G.; Hildebrandt, P.

    2011-05-01

    Phytochromes constitute a family of red-light sensing photoreceptors in plants and microorganisms. The photoactive cofactor is an open-chain methine-bridged tetrapyrrole that, upon light absorption, undergoes a double bond isomerisation followed by series thermal relaxation processes which eventually lead to the functional structural change of the protein. Resonance Raman spectroscopy has contributed significantly to the understanding of the molecular functioning of these proteins although both the experiments and the interpretation of the spectra represent a considerable challenge. This account is dedicated to describe achievements, potential and limitations of combined resonance Raman spectroscopic and theoretical approaches for elucidating cofactor structures in phytochromes. Experimental approaches are discussed paying specific attention on strategies to overcome unwanted photochemical and photophysical processes when probing the various states of the photoinduced reaction cycle of phytochromes. The most comprehensive set of experimental data on phytochromes, including engineered protein variants and adducts formed with isotopically labelled tetrapyrroles, has been obtained by resonance Raman spectroscopy with near-infrared excitation that also allows probing phytochrome crystals without photo-induced destruction. Quantum mechanical calculations of Raman spectra of model compounds represent a first approximation for determining the methine bridge geometry of the protein-bound tetrapyrroles and constitute the basis for the identification of marker bands for specific structural properties such as the protonation state of the cofactor. Drawbacks of this theoretical method that inevitably neglects the protein environment have become evident with the first determinations of three-dimensional structures of phytochromes. These structural models can now be used for employing hybrid methods that combine quantum mechanical and molecular mechanics calculations of the

  20. Ultrahigh-Resolution Magnetic Resonance in Inhomogeneous Magnetic Fields: Two-Dimensional Long-Lived-Coherence Correlation Spectroscopy

    Science.gov (United States)

    Chinthalapalli, Srinivas; Bornet, Aurélien; Segawa, Takuya F.; Sarkar, Riddhiman; Jannin, Sami; Bodenhausen, Geoffrey

    2012-07-01

    A half-century quest for improving resolution in Nuclear Magnetic Resonance (NMR) and Magnetic Resonance Imaging (MRI) has enabled the study of molecular structures, biological interactions, and fine details of anatomy. This progress largely relied on the advent of sophisticated superconducting magnets that can provide stable and homogeneous fields with temporal and spatial variations below ΔB0/B0lungs, tissue-air interfaces, surgical implants, etc., lead to fluctuations and losses of local homogeneity. A new method dubbed “long-lived-coherence correlation spectroscopy” (LLC-COSY) opens the way to overcome both inhomogeneous and homogeneous broadening, which arise from local variations in static fields and fluctuating dipole-dipole interactions, respectively. LLC-COSY makes it possible to obtain ultrahigh resolution two-dimensional spectra, with linewidths on the order of Δν=0.1 to 1 Hz, even in very inhomogeneous fields (ΔB0/B0>10ppm or 5000 Hz at 9.7 T), and can improve resolution by a factor up to 9 when the homogeneous linewidths are determined by dipole-dipole interactions. The resulting LLC-COSY spectra display chemical shift differences and scalar couplings in two orthogonal dimensions, like in “J spectroscopy.” LLC-COSY does not require any sophisticated gradient switching or frequency-modulated pulses. Applications to in-cell NMR and to magnetic resonance spectroscopy (MRS) of selected volume elements in MRI appear promising, particularly when susceptibility variations tend to preclude high resolution.

  1. In vivo proton magnetic resonance spectroscopy reveals region specific metabolic responses to SIV infection in the macaque brain

    Directory of Open Access Journals (Sweden)

    Joo Chan-Gyu

    2009-06-01

    Full Text Available Abstract Background In vivo proton magnetic resonance spectroscopy (1H-MRS studies of HIV-infected humans have demonstrated significant metabolic abnormalities that vary by brain region, but the causes are poorly understood. Metabolic changes in the frontal cortex, basal ganglia and white matter in 18 SIV-infected macaques were investigated using MRS during the first month of infection. Results Changes in the N-acetylaspartate (NAA, choline (Cho, myo-inositol (MI, creatine (Cr and glutamine/glutamate (Glx resonances were quantified both in absolute terms and relative to the creatine resonance. Most abnormalities were observed at the time of peak viremia, 2 weeks post infection (wpi. At that time point, significant decreases in NAA and NAA/Cr, reflecting neuronal injury, were observed only in the frontal cortex. Cr was significantly elevated only in the white matter. Changes in Cho and Cho/Cr were similar across the brain regions, increasing at 2 wpi, and falling below baseline levels at 4 wpi. MI and MI/Cr levels were increased across all brain regions. Conclusion These data best support the hypothesis that different brain regions have variable intrinsic vulnerabilities to neuronal injury caused by the AIDS virus.

  2. Formation of continuous metallic film on quartz studied by noncontact resonant ultrasound spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Nakamura, N., E-mail: nobutomo@me.es.osaka-u.ac.jp; Yoshimura, N.; Ogi, H.; Hirao, M. [Osaka University, Graduate School of Engineering Science, Toyonaka, Osaka 560-8531 (Japan)

    2015-08-28

    Dynamics of continuous film formation of metallic films on quartz substrates is studied using an electrodeless resonance method. Bare quartz is used as a substrate, and a metallic film is deposited on it. We use antenna transmission technique to measure the evolution of resonance frequencies and internal friction of the substrate during and after deposition, and the morphological transition between discontinuous islands and a continuous film is detected. By comparison with atomic force microscopy images, we confirm that the frequency drop and the internal-friction peak that appear during deposition indicate this transition. We also find that Pt film shows unexpected morphology change after deposition.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2010-03-01

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

  4. 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...

  5. 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.

  6. Nuclear Magnetic Resonance (NMR) Spectroscopy For Metabolic Profiling of Medicinal Plants and Their Products.

    Science.gov (United States)

    Kumar, Dinesh

    2016-09-01

    NMR spectroscopy has multidisciplinary applications, including excellent impact in metabolomics. The analytical capacity of NMR spectroscopy provides information for easy qualitative and quantitative assessment of both endogenous and exogenous metabolites present in biological samples. The complexity of a particular metabolite and its contribution in a biological system are critically important for understanding the functional state that governs the organism's phenotypes. This review covers historical aspects of developments in the NMR field, its applications in chemical profiling, metabolomics, and quality control of plants and their derived medicines, foods, and other products. The bottlenecks of NMR in metabolic profiling are also discussed, keeping in view the future scope and further technological interventions.

  7. Coherent phonon spectroscopy of non-fully symmetric modes using resonant terahertz excitation

    Energy Technology Data Exchange (ETDEWEB)

    Huber, T., E-mail: tihuber@phys.ethz.ch; Huber, L.; Johnson, S. L. [Institute for Quantum Electronics, Physics Department, ETH Zurich, CH-8093 Zurich (Switzerland); Ranke, M. [The Hamburg Centre for Ultrafast Imaging, Luruper Chaussee 149, D-22761 Hamburg (Germany); Ferrer, A. [Institute for Quantum Electronics, Physics Department, ETH Zurich, CH-8093 Zurich (Switzerland); Swiss Light Source, Paul Scherrer Institut, CH-5232 Villigen PSI (Switzerland)

    2015-08-31

    We use intense terahertz (THz) frequency electromagnetic pulses generated via optical rectification in an organic crystal to drive vibrational lattice modes in single crystal Tellurium. The coherent modes are detected by measuring the polarization changes of femtosecond laser pulses reflecting from the sample surface, resulting in a phase-resolved detection of the coherent lattice motion. We compare the data to a model of Lorentz oscillators driven by the near-single-cycle broadband THz pulse. The demonstrated technique of optically probed coherent phonon spectroscopy with THz frequency excitation could prove to be a viable alternative to other time-resolved spectroscopic methods like standard THz time domain spectroscopy.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2016-06-14

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

  9. Quantum State Absorptions Coupled To Resonance Raman Spectroscopy Could Result In A General Explanation of TERS

    CERN Document Server

    Schultz, Zachary D; Dekhter, Rimma; Anestopoulos, Dimitris; Grammatikopoulos, Spyridon; Papagelis, Kostantinos; Marr, James M; Lewis, David; Galiotis, Costas; Lev, Dimtry; Lewis, Aaron

    2016-01-01

    Tip enhanced Raman scattering (TERS) amplifies the intensity of vibrational Raman scattering by employing the tip of a probe interacting, in ultra close proximity, with a surface. Although a general understanding of the TERS process is still to be fully elucidated, scanning tunneling microscopy (STM) feedback is often applied with success in TERS to keep a noble metal probe in intimate proximity with a noble metal substrate. Since such STM TERS is a common modality, the possible implications of plasmonic fields that may be induced by the tunneling process are investigated and reported. In addition, TERS of a 2D resonant molecular system, a MoS2 bilayer crystal and a 2D non-resonant, lipid molecular bilayer is compared. Data with multiple excitation wavelengths and surfaces for the resonant system in the near- (TERS) and far-field regimes are reported. An interpretation based on weak coupling interactions within the framework of conventional resonance Raman scattering can explain the observed TERS enhancements...

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

    NARCIS (Netherlands)

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

    2004-01-01

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

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

    DEFF Research Database (Denmark)

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

    2001-01-01

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

  12. 1H nuclear magnetic resonance spectroscopy-basedmetabonomic study in patients with cirrhosis and hepaticencephalopathy

    Institute of Scientific and Technical Information of China (English)

    2015-01-01

    AIM To identify plasma metabolites used as biomarkersin order to distinguish cirrhotics from controls and encephalopathics.METHODS: A clinical study involving stable cirrhoticpatients with and without overt hepatic encephalopathywas designed. A control group of healthy volunteers wasused. Plasma from those patients was analysed using1H - nuclear magnetic resonance spectroscopy. Weused the Carr Purcell Meiboom Gill sequence to processthe sample spectra at ambient probe temperature. Weused a gated secondary irradiation field for water signalsuppression. Samples were calibrated and referencedusing the sodium trimethyl silyl propionate peak at0.00 ppm. For each sample 128 transients (FID's)were acquired into 32 K complex data points over aspectral width of 6 KHz. 30 degree pulses were appliedwith an acquisition time of 4.0 s in order to achievebetter resolution, followed by a recovery delay of 12s, to allow for complete relaxation and recovery ofthe magnetisation. A metabolic profile was created forstable cirrhotic patients without signs of overt hepaticencephalopathy and encephalopathic patients as wellas healthy controls. Stepwise discriminant analysis wasthen used and discriminant factors were created todifferentiate between the three groups.RESULTS: Eighteen stabled cirrhotic patients, eighteenpatients with overt hepatic encephalopathy and seventeenhealthy volunteers were recruited. Patients with cirrhosishad significantly impaired ketone body metabolism, ureasynthesis and gluconeogenesis. This was demonstratedby higher concentrations of acetoacetate (0.23 ± 0.02vs 0.05 ± 0.00, P 〈 0.01), and b-hydroxybutarate (0.58± 0.14 vs 0.08 ± 0.00, P 〈 0.01), lower concentrationsof glutamine (0.44 ± 0.08 vs 0.63 ± 0.03, P 〈 0.05),histidine (0.16 ± 0.01 vs 0.36 ± 0.04, P 〈 0.01) andarginine (0.08 ± 0.01 vs 0.14 ± 0.02, P 〈 0.03) andhigher concentrations of glutamate (1.36 ± 0.25 vs0.58 ± 0.04, P 〈 0.01), lactate (1

  13. Neutron resonance transmission spectroscopy with high spatial and energy resolution at the J-PARC pulsed neutron source

    Energy Technology Data Exchange (ETDEWEB)

    Tremsin, A.S., E-mail: ast@ssl.berkeley.edu [University of California at Berkeley, 7 Gauss Way, Berkeley, CA 94720 (United States); Shinohara, T.; Kai, T.; Ooi, M. [Japan Atomic Energy Agency, 2–4 Shirakata-shirane, Tokai-mura, Naka-gun, Ibaraki 319-1195 (Japan); Kamiyama, T.; Kiyanagi, Y.; Shiota, Y. [Hokkaido University, Kita 13 Nishi 8 Kita-ku, Sapporo-shi, Hokkaido 060-8628 (Japan); McPhate, J.B.; Vallerga, J.V.; Siegmund, O.H.W. [University of California at Berkeley, 7 Gauss Way, Berkeley, CA 94720 (United States); Feller, W.B. [NOVA Scientific, Inc., 10 Picker Rd., Sturbridge, MA 01566 (United States)

    2014-05-11

    The sharp variation of neutron attenuation at certain energies specific to particular nuclides (the lower range being from ∼1 eV up to ∼1 keV), can be exploited for the remote mapping of element and/or isotope distributions, as well as temperature probing, within relatively thick samples. Intense pulsed neutron beam-lines at spallation sources combined with a high spatial, high-timing resolution neutron counting detector, provide a unique opportunity to measure neutron transmission spectra through the time-of-flight technique. We present the results of experiments where spatially resolved neutron resonances were measured, at energies up to 50 keV. These experiments were performed with the intense flux low background NOBORU neutron beamline at the J-PARC neutron source and the high timing resolution (∼20 ns at epithermal neutron energies) and spatial resolution (∼55 µm) neutron counting detector using microchannel plates coupled to a Timepix electronic readout. Simultaneous element-specific imaging was carried out for several materials, at a spatial resolution of ∼150 µm. The high timing resolution of our detector combined with the low background beamline, also enabled characterization of the neutron pulse itself – specifically its pulse width, which varies with neutron energy. The results of our measurements are in good agreement with the predicted results for the double pulse structure of the J-PARC facility, which provides two 100 ns-wide proton pulses separated by 600 ns, broadened by the neutron energy moderation process. Thermal neutron radiography can be conducted simultaneously with resonance transmission spectroscopy, and can reveal the internal structure of the samples. The transmission spectra measured in our experiments demonstrate the feasibility of mapping elemental distributions using this non-destructive technique, for those elements (and in certain cases, specific isotopes), which have resonance energies below a few keV, and with lower

  14. A transient method for measuring the gas volume fraction in a mixed gas-liquid flow using acoustic resonance spectroscopy

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    In this paper, the feasibility of measuring the gas volume fraction in a mixed gas-liquid flow by using an acoustic resonant spectroscopy (ARS) method in a transient way is studied theoretically and experimentally. Firstly, the effects of sizes and locations of a single air bubble in a cylindrical cavity with two open ends on resonant frequencies are investigated numerically. Then, a transient measurement system for ARS is established, and the trends of the resonant frequencies (RFs) and resonant amplitudes (RAs) in the cylindrical cavity with gas flux inside are investigated experimentally. The measurement results by the proposed transient method are compared with those by steady-state ones and numerical ones. The numerical results show that the RFs of the cavity are highly sensitive to the volume of the single air bubble. A tiny bubble volume perturbation may cause a prominent RF shift even though the volume of the air bubble is smaller than 0.1% of that of the cavity. When the small air bubble moves, the RF shift will change and reach its maximum value as it is located at the middle of the cavity. As the gas volume fraction of the two-phase flow is low, both the RFs and RAs from the measurement results decrease dramatically with the increasing gas volume, and this decreasing trend gradually becomes even as the gas volume fraction increases further. These experimental results agree with the theoretical ones qualitatively. In addition, the transient method for ARS is more suitable for measuring the gas volume fraction with randomness and instantaneity than the steady-state one, because the latter could not reflect the random and instant characteristics of the mixed fluid due to the time consumption for frequency sweeping. This study will play a very important role in the quantitative measurement of the gas volume fraction of multiphase flows.

  15. 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....

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

    DEFF Research Database (Denmark)

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

    1992-01-01

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

  17. 3μm - 1.6μm Double Resonance Spectroscopy of CH_4

    Science.gov (United States)

    Schwartz, George; Belaas, Erik; Yang, Shaoyue; Lehmann, Kevin

    2016-06-01

    The Near-IR Spectrum of CH_4 is dense with many overlapping bands that perturb each other by vibrational and ro-vibrational interactions. Assignments of the individual lines are needed in order to simulate the spectrum as a function of pressure and temperature, as needed in the search for CH_4 in extrasolar planets. Both the group at the University College, London^1 and that at the University of Reins^2 have produced theoretical spectra that allows simulation up to the high temperatures expected on ``Hot Jupiters''. The accuracy of these theoretical spectra need to be further tested. Because CH_4 is a light spherical top, assignment of its perturbed spectra is a formable challenge as none of the lines allowed in the rigid rotor approximation have ground vibrational state combination differences. We are using IR-IR double resonance to observe modulation in the strength of near-IR absorption caused by a modulation of a 3 μm OPO beam that is tuned to a particular transition in the C-H stretching fundamental of CH_4. This produces V-type double resonance transitions (which share the lower state with the pump transition), which provides firm assignments for lines normally observed in absorption in the near-IR. We also observe sequential double resonance which reveals transitions that have a known rotational level of the ν_3 fundamental as the lower state and reaches final states in the 9000 cm-1 spectral region. These are states of A, E, F_1 vibrational symmetries which are forbidden in transitions from the ground vibrational state. These 3 level double resonance transitions are Doppler Free and have a linewidth of ˜10 MHz due to a combination of near-IR laser jitter and power broadening of the mid-IR transition. We also observed many 4-level double resonance transitions that we have tentatively assigned as arising from the ν_4 fundamental level. These are distinguished from the 3-level double resonance transitions by they being Doppler broadened and having a large

  18. Application of Laser Magnetic Resonance Spectroscopy to the Measurement of Electric Dipole Moment of Free Radicals

    Institute of Scientific and Technical Information of China (English)

    郭远清; 黄光明; 林洁丽; 段传喜; 李奉延; 李津蕊; 刘煜炎

    2001-01-01

    An intracavity CO laser magnetic resonance spectrometer with homogeneous dc electric field applied via a pairof parallel Stark plates in the absorption cell is used to measure the electric dipole moments of free radicals.Taking advantage of the high sensitivity and high resolution of this technique and the Stark effect, highlyresolved saturated absorption spectra of the ν = 1 - 0 transition of 15 N16 O in the ground state X2 П3/2 have beensuccessfully observed in the presence of a low electric field. The electric dipole moment of NO in the electronicground state is determined asμ = 0.1566 ± 14D (Debye) from the analysis of the observed spectra, confirmingthat, combined with the Stark field, the laser magnetic resonance technique can be an effective and reliableapproach for the precise measurement of electric dipole moments of free radicals, especially unstable ones.

  19. Resonance-enhanced photon excitation spectroscopy of the even-parity autoionizing Rydberg states of Kr

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Kr atoms were produced in their metastable states 4p55s [3/2]2 and 4p55s’ [1/2]0 in a pulsed DC dis-charge in a beam,and subsequently excited to the even-parity autoionizing Rydberg states 4p5np’ [3/2]1,2,[1/2]1 and 4p5nf’ [5/2]3 using single photon excitation.The excitation spectra of the even-parity autoionizing resonance series from the metastable Kr were obtained by recording the autoionized Kr+ ions with time-of-flight ion detection in the photon energy range of 29000-40000 cm1.A wealth of autoionizing resonances were newly observed,from which more precise and more systematic spec-troscopic data of the level energy and quantum defects were derived.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1998-04-01

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

  1. Nanolaser spectroscopy and micro-optical resonators for detecting, analyzing, and manipulating bioparticles

    Science.gov (United States)

    Gourley, Paul L

    2012-06-26

    This invention provides a new method for rapidly analyzing single bioparticles to assess their material condition and state of health. The method is enabled by use of a resonant cavity apparatus to measure an optical property related to the bioparticle size and refractive index. Measuring the refractive index is useful for determining material properties of the bioparticle. The material properties depend on the biomolecular composition of the bioparticle. The biomolecular composition is, in turn, dependent on the state of health of the bioparticle. Thus, measured optical properties can be used to differentiate normal (healthy) and abnormal (diseased) states of bioparticles derived from cells or tissues. The method is illustrated with data obtained from a resonator with a gain medium. The invention also provides new methods for making multiple measurements in a single device and detecting, analyzing, and manipulating bioparticles that are much smaller than the wavelength of light.

  2. Resonance-enhanced photon excitation spectroscopy of the even-parity autoionizing Rydberg states of Kr

    Institute of Scientific and Technical Information of China (English)

    LI ChunYan; WANG TingTing; ZHEN JunFeng; ZHANG Qun; CHEN Yang

    2009-01-01

    Kr atoms were produced in their metastable states 4p55s [3/2]2 and 4p55s' [1/2]0 in a pulsed DC discharge in a beam, and subsequently excited to the even-parity autoionizing Rydberg states 4p5np' [3/2]1,2, [1/2]1 and 4p5nf' [5/2]3 using single photon excitation. The excitation spectra of the even-parity autoionizing resonance series from the metastable Kr were obtained by recording the autoionized Kr+ ions with time-of-flight ion detection in the photon energy range of 29000-40000 cm-1. A wealth of autoionizing resonances were newly observed, from which more precise and more systematic spec-troscopic data of the level energy and quantum defects were derived.

  3. Resonance-Enhanced Photon Excitation Spectroscopy of the Even-Parity Autoionizing Rydberg States of Xe

    Institute of Scientific and Technical Information of China (English)

    Chun-yan Li; Ting-ting Wang; Jun-feng Zhen; Qun Zhang; Yang Chen

    2008-01-01

    Xenon atoms were produced in their metastable states 5p56s[3/2]2 and 5p56s'[1/2]0 in a pulsed DC discharge in a beam, and subsequently excited to the even-parity autoionizing Rydberg states 5p5np' [3/2] 1 ,[1/2]1, t, and 5p5 nf'[5/2]3 using single photon excitation. The excitation spectra of the even-parity autoionizing resonance series from the metastable 129Xe were obtained by recording the autoionized Xe+ with time-of-flight ion detection in the photon energy range of 28000-42000 cm-1. A wealth of autoionizing resonances were newly observed, from which more precise and systematic spectroscopic data of the level energies and quantum defects were derived.

  4. Resonant Optical Gradient Force Interaction for Nano-Imaging and-Spectroscopy

    Science.gov (United States)

    2016-07-19

    frequency dependence of the optically induced force is often explored in optical trapping ofmicro-/ nanoparticles [5, 26–32], and in the optically...interpreted to result from an optical gradient force [38]. In contrast, similar force images on gold split ring resonators were attributed to thermal...reduced to an image sphere of radius r, as shown infigure 1(a). This coupled nanoparticle geometry has been used extensively andwith great success

  5. Detection of reactive oxygen species in isolated, perfused lungs by electron spin resonance spectroscopy

    OpenAIRE

    Schudt Christian; Schermuly Ralph T; Ghofrani Hossein A; Schütte Hartwig; Schäfer Rolf U; Tiyerili Vedat; Fuchs Beate; Kuzkaya Nermin; Weissmann Norbert; Sydykov Akylbek; Egemnazarow Bakytbek; Seeger Werner; Grimminger Friedrich

    2005-01-01

    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 v...

  6. Confocal microscopy and spectroscopy of nanocrystals on a high-Q microsphere resonator

    Energy Technology Data Exchange (ETDEWEB)

    Goetzinger, S [Institut fuer Physik, Humboldt-Universitaet zu Berlin, D-10117 Berlin (Germany); Menezes, L de S [Institut fuer Physik, Humboldt-Universitaet zu Berlin, D-10117 Berlin (Germany); Benson, O [Institut fuer Physik, Humboldt-Universitaet zu Berlin, D-10117 Berlin (Germany); Talapin, D V [Institut fuer Physikalische Chemie, Universitaet Hamburg, D-20146 Hamburg (Germany); Gaponik, N [Institut fuer Physikalische Chemie, Universitaet Hamburg, D-20146 Hamburg (Germany); Weller, H [Institut fuer Physikalische Chemie, Universitaet Hamburg, D-20146 Hamburg (Germany); Rogach, A L [Sektion Physik und CeNS, LMU Muenchen, D-80799 Munich (Germany); Sandoghdar, V [Laboratory of Physical Chemistry, Swiss Federal Institute of Technology (ETH), CH-8093 Zurich (Switzerland)

    2004-02-01

    We report on experiments where we used a home-made confocal microscope to excite single nanocrystals on a high-Q microsphere resonator. In that way spectra of an individual quantum emitter could be recorded. The Q factor of the microspheres coated with nanocrystals was still up to 10{sup 9}. We also demonstrate the use of a prism coupler as a well-defined output port to collect the fluorescence of an ensemble of nanocrystals coupled to whispering-gallery modes.

  7. Precision spectroscopy with COMPASS and the observation of a new iso-vector resonance

    Directory of Open Access Journals (Sweden)

    Paul Stephan

    2014-06-01

    Full Text Available We report on the results of a novel partial-wave analysis based on 50 ⋅ 106 events from the reaction π− + p → π−π−π+ + precoil at 190 GeV/c incoming beam momentum using the COMPASS spectrometer. A separated analysis in bins of m3π and four-momentum transfer t′ reveals the interference of resonant and non-resonant particle production and allows their spectral separation. Besides well known resonances we observe a new iso-vector meson a1(1420 at a mass of 1420 MeV/c2 in the f0(980π final state only, the origin of which is unclear. We have also examined the structure of the 0++ππ-isobar in the JPC = 0−+, 1++, 2−+ three pion waves. This clearly reveals the various 0++ππ-isobar components and its correlation to the decay of light mesons.

  8. Resolution Improvement in Multidimensional Nuclear Magnetic Resonance Spectroscopy of Proteins; Amelioration de la resolution dans la resonance magnetique nucleaire multidimensionnelle des proteines

    Energy Technology Data Exchange (ETDEWEB)

    Duma, L

    2004-07-01

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

  9. One- and Two-Dimensional Nuclear Magnetic Resonance Spectroscopy with a Diamond Quantum Sensor

    Science.gov (United States)

    Boss, J. M.; Chang, K.; Armijo, J.; Cujia, K.; Rosskopf, T.; Maze, J. R.; Degen, C. L.

    2016-05-01

    We report on Fourier spectroscopy experiments performed with near-surface nitrogen-vacancy centers in a diamond chip. By detecting the free precession of nuclear spins rather than applying a multipulse quantum sensing protocol, we are able to unambiguously identify the NMR species devoid of harmonics. We further show that, by engineering different Hamiltonians during free precession, the hyperfine coupling parameters as well as the nuclear Larmor frequency can be selectively measured with up to five digits of precision. The protocols can be combined to demonstrate two-dimensional Fourier spectroscopy. Presented techniques will be useful for mapping nuclear coordinates in molecules deposited on diamond sensor chips, en route to imaging their atomic structure.

  10. Magnetic Resonance Spectroscopy: An Objective Modality to Identify the Pathology of Breast Neoplasms

    Science.gov (United States)

    1999-05-01

    confirmed as invasive Miscellaneous 2 carcinoma, but with a marked inflam- Phyllodes tumor 2 matory cell infiltrate. DCIS* (n = 17)* Other Clinical... Phyllodes type 66 cytologic analysis (separate specimen than tumors are classified as fibroepithelial Ductal carcinoma of no special that in MR spectroscopy...propensity to lo- Tubular carcinoma 4 RESULTS cal recurrence to blood-borne metasta- hSample Collection sis. Both phyllodes tumors were ex- Note

  11. In vivo proton magnetic resonance spectroscopy of intraventricular tumours of the brain

    Energy Technology Data Exchange (ETDEWEB)

    Majos, Carles; Aguilera, Carles [Hospital Universitari de Bellvitge, Institut de Diagnostic per la Imatge (IDI). Centre Bellvitge, L' Hospitalet de Llobregat, Barcelona (Spain); Biomateriales y Nanomedicina (CIBER-BBN), Centro de Investigacion Biomedica en Red en Bioingenieria, Cerdanyola del Valles (Spain); Cos, Monica; Camins, Angels; Samitier, Alex; Castaner, Sara; Sanchez, Juan J. [Hospital Universitari de Bellvitge, Institut de Diagnostic per la Imatge (IDI). Centre Bellvitge, L' Hospitalet de Llobregat, Barcelona (Spain); Candiota, Ana P.; Delgado-Goni, Teresa [Biomateriales y Nanomedicina (CIBER-BBN), Centro de Investigacion Biomedica en Red en Bioingenieria, Cerdanyola del Valles (Spain); Unitat de Bioquimica de Biociencies, Department de Bioquimica i Biologia Molecular, Cerdanyola del Valles (Spain); Mato, David [Hospital Universitari de Bellvitge, Department of Neurosurgery, L' Hospitalet de Llobregat, Barcelona (Spain); Acebes, Juan J. [Hospital Universitari de Bellvitge, Department of Neurosurgery, L' Hospitalet de Llobregat, Barcelona (Spain); Biomateriales y Nanomedicina (CIBER-BBN), Centro de Investigacion Biomedica en Red en Bioingenieria, Cerdanyola del Valles (Spain); Arus, Carles [Unitat de Bioquimica de Biociencies, Department de Bioquimica i Biologia Molecular, Cerdanyola del Valles (Spain); Biomateriales y Nanomedicina (CIBER-BBN), Centro de Investigacion Biomedica en Red en Bioingenieria, Cerdanyola del Valles (Spain)

    2009-08-15

    The aim of this study was to assess the usefulness of proton MR spectroscopy in the diagnosis of intraventricular tumours. Fifty-two intraventricular tumours pertaining to 16 different tumour types were derived from our database. All cases had single-voxel proton MR spectroscopy performed at TE at both 30 and 136 ms at 1.5 T. The Mann-Whitney U test was used to search for the most discriminative datapoints each tumour type. Characteristic trends were found for some groups: high Glx and Ala in meningiomas (p<0.001 and p<0.01, respectively), high mobile lipids in metastasis (p<0.001), high Cho in PNET (p<0.001), high mI+Gly in ependymoma (p<0.001), high NAC (p<0.01) in the absence of the normal brain parenchyma pattern in colloid cysts, and high mI/Gly and Ala in central neurocytoma. Proton MR spectroscopy provides additional metabolic information that could be useful in the diagnosis of intraventricular brain tumors. (orig.)

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

    Science.gov (United States)

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

    2017-01-15

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

  13. Stimulated Raman spectroscopy and nanoscopy of molecules using near field photon induced forces without resonant electronic enhancement gain

    Science.gov (United States)

    Tamma, Venkata Ananth; Huang, Fei; Nowak, Derek; Kumar Wickramasinghe, H.

    2016-06-01

    We report on stimulated Raman spectroscopy and nanoscopy of molecules, excited without resonant electronic enhancement gain, and recorded using near field photon induced forces. Photon-induced interaction forces between the sharp metal coated silicon tip of an Atomic Force Microscope (AFM) and a sample resulting from stimulated Raman excitation were detected. We controlled the tip to sample spacing using the higher order flexural eigenmodes of the AFM cantilever, enabling the tip to come very close to the sample. As a result, the detection sensitivity was increased compared with previous work on Raman force microscopy. Raman vibrational spectra of azobenzene thiol and l-phenylalanine were measured and found to agree well with published results. Near-field force detection eliminates the need for far-field optical spectrometer detection. Recorded images show spatial resolution far below the optical diffraction limit. Further optimization and use of ultrafast pulsed lasers could push the detection sensitivity towards the single molecule limit.

  14. Investigation of bacterial spore structure by high resolution solid-state nuclear magnetic resonance spectroscopy and transmission electron microscopy.

    Science.gov (United States)

    Leuschner, R G; Lillford, P J

    2001-01-22

    High resolution solid-state nuclear magnetic resonance spectroscopy (NMR) in combination with transmission electron microscopy (TEM) of spores of Bacillus cereus, an outer coatless mutant B. subtilis 322, an inner coatless mutant B. subtilis 325 and of germinated spores of B. subtilis CMCC 604 were carried out. Structural differences in the coats, mainly protein of spores were reflected by NMR spectra which indicated also differences in molecular mobility of carbohydrates which was partially attributed to the cortex. Dipicolinic acid (DPA) of spores of B. cereus displayed a high degree of solid state order and may be crystalline. Heat activation was studied on spores of B. subtilis 357 lux + and revealed a structural change when analysed by TEM but this was not associated with increases in molecular mobility since no effects were measured by NMR.

  15. Is it Possible to Extract Brain Metabolic Pathways Information from In Vivo H Nuclear Magnetic Resonance Spectroscopy Data?

    CERN Document Server

    de Lara, Alejandro Chinea Manrique

    2010-01-01

    In vivo H nuclear magnetic resonance (NMR) spectroscopy is an important tool for performing non-invasive quantitative assessments of brain tumour glucose metabolism. Brain tumours are considered as fast-growth tumours because of their high rate of proliferation. In addition, tumour cells exhibit profound genetic, biochemical and histological differences with respect to the original non-transformed cellular types. Therefore, there is a strong interest from the clinical investigator point of view in understanding the role of brain metabolites in normal and pathological conditions and especially on the development of early tumour detection techniques. Unfortunately, current diagnosis techniques ignore the dynamic aspects of these signals. It is largely believed that temporal variations of NMR Spectra are noisy or just simply do not carry enough information to be exploited by any reliable diagnosis procedure. Thus, current diagnosis procedures are mainly based on empirical observations extracted from single avera...

  16. A magnetic-field enriched surface-enhanced resonance Raman spectroscopy strategy towards the early diagnosis of malaria

    Science.gov (United States)

    Yuen, Clement; Liu, Quan

    2012-03-01

    Early malaria diagnosis is important because malaria disease can develop into fatal illness within hours upon the appearance of the first symptom. The low concentration of the diagnosis biomarker, hemozoin, at the early stage of malaria disease makes early diagnosis difficult. In this paper, we present a magnetic field-enriched surface-enhanced resonance Raman spectroscopy (SERRS) strategy for the sensitive detection of β - hematin crystals, which is equivalent to hemozoin in the characteristics of Raman spectrum, by using magnetic nanoparticles. We observe several orders of magnitude enhancement in the SERRS signal of enriched β - hematin in comparison to the Raman signal of β - hematin in the cases of SERRS alone or magnetic enrichment alone, showing the great potential of this method towards early malaria diagnosis.

  17. A Mononuclear Mn(II) Pseudoclathrochelate Complex Studied by Multi-Frequency Electron-Paramagnetic-Resonance Spectroscopy.

    Science.gov (United States)

    Azarkh, Mykhailo; Penkova, Larysa V; Kats, Svitlana V; Varzatskii, Oleg A; Voloshin, Yan Z; Groenen, Edgar J J

    2014-03-06

    Knowledge of the correlation between structural and spectroscopic properties of transition-metal complexes is essential to deepen the understanding of their role in catalysis, molecular magnetism, and biological inorganic chemistry. It provides topological and, sometimes, functional insight with respect to the active site properties of metalloproteins. The electronic structure of a high-spin mononuclear Mn(II) pseudoclathrochelate complex has been investigated by electron-paramagnetic-resonance (EPR) spectroscopy at 9.5 and 275.7 GHz. A substantial, virtually axial zero-field splitting with D = -9.7 GHz (-0.32 cm(-1)) is found, which is the largest one reported to date for a Mn(II) complex with six nitrogen atoms in the first coordination sphere.

  18. Sub-terahertz spectroscopy of magnetic resonance in BiFeO3 using a vector network analyzer

    Science.gov (United States)

    Caspers, Christian; Gandhi, Varun P.; Magrez, Arnaud; de Rijk, Emile; Ansermet, Jean-Philippe

    2016-06-01

    Detection of sub-THz spin cycloid resonances (SCRs) of stoichiometric BiFeO3 (BFO) was demonstrated using a vector network analyzer. Continuous wave absorption spectroscopy is possible, thanks to heterodyning and electronic sweep control using frequency extenders for frequencies from 480 to 760 GHz. High frequency resolution reveals SCR absorption peaks with a frequency precision in the ppm regime. Three distinct SCR features of BFO were observed and identified as Ψ1 and Φ2 modes, which are out-of-plane and in-plane modes of the spin cycloid, respectively. A spin reorientation transition at 200 K is evident in the frequency vs temperature study. The global minimum in linewidth for both Ψ modes at 140 K is ascribed to the critical slowing down of spin fluctuations.

  19. Cerebral Magnetic Resonance Spectroscopy Demonstrates Long-Term Effect of Bone Marrow Transplantation in α-Mannosidosis

    DEFF Research Database (Denmark)

    Danielsen, Else R; Lund, Allan M; Thomsen, Carsten

    2013-01-01

    α-Mannosidosis, OMIM #248500, is an autosomal recessive lysosomal storage disease caused by acidic α-mannosidase deficiency. Treatment options include bone marrow transplantation (BMT) and, possibly in the future, enzyme replacement therapy. Brain magnetic resonance spectroscopy (MRS) enables non......-invasive monitoring of cerebral treatment effect. Accumulated cerebral mannose-containing oligosaccharides were demonstrated by MRS in a patient who at age 2 years and 11 months received a BMT from a haploidentical non-carrier sibling. The cerebral mannose-containing oligosaccharides had disappeared as early as 9......½ months after BMT. MRS furthermore demonstrated the persistent treatment effect at regular intervals up to 5½ years after BMT. MRS is a non-invasive tool that can demonstrate the effect of BMT treatment. Likewise, MRS may be used to demonstrate the cerebral effect of other potential treatments...

  20. A study of familial MELAS: Evaluation of A3243G mutation, clinical phenotype, and magnetic resonance spectroscopy-monitored progression

    Directory of Open Access Journals (Sweden)

    Chunnuan Chen

    2012-01-01

    Full Text Available The clinical manifestations of mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episodes syndrome (MELAS syndrome are nonspecific and can easily be misdiagnosed. Magnetic resonance spectroscopy (MRS-based detection of lactate in the brain has been found to be of diagnostic help in MELAS syndrome, however, the issue of whether MRS features vary by stage remains unresolved. We assessed the causative mutation and radiological features of a family of MELAS. Four of the family members harbored the A3243G mutation, probably of maternal inheritance. However, the clinical phenotypic expression was different in these patients. MRS showed a lactate peak, decreased N-acetylaspartate, choline, and creatine, which became more pronounced with progression of the disease, demonstrating that brain-MRS-based detection of lactate may be a suitable way to monitor the progression and treatment of MELAS.

  1. Magnetic resonance spectroscopy in the evaluation of treatment efficacy in unipolar major depressive disorder: a review of the literature.

    Science.gov (United States)

    Caverzasi, Eduardo; Pichiecchio, Anna; Poloni, Guy Umberto; Calligaro, Alessandro; Pasin, Moreno; Palesi, Fulvia; Castellazzi, Gloria; Pasquini, Massimo; Biondi, Massimo; Barale, Francesco; Bastianello, Stefano

    2012-01-01

    More and more neuroimaging studies are using in vivo proton magnetic resonance spectroscopy (1H-MRS) to explore correlates of response to therapy in major depressive disorder (MDD). Their aim is to further understanding of the effects of neurotransmitter changes in areas involved in MDD and the mechanisms underlying a good treatment response. We set out to summarise the literature from the past fifteen years on biochemical correlates of treatment response in MDD patients, reflected in pre- and post-therapy changes in 1H-MRS measurements. Our literature search identified fifteen articles reporting 1H-MRS studies in MDD treatment; no study used 1P-MRS. Despite the wide diversity of 1H-MRS methods applied, brain regions studied, and metabolite changes found, there emerged strong evidence of a correlation between changes in neurometabolite concentrations, in particular glutamate, N-acetylaspartate and choline, and a good treatment response to pharmacotherapy or antidepressant stimulation techniques.

  2. Depth profiles of pulmonary surfactant protein B in phosphatidylcholine bilayers, studied by fluorescence and electron spin resonance spectroscopy

    DEFF Research Database (Denmark)

    Cruz, A; Casals, C; Plasencia, I;

    1998-01-01

    Pulmonary surfactant-associated protein B (SP-B) has been isolated from porcine lungs and reconstituted in bilayers of dipalmitoylphosphatidylcholine (DPPC) or egg yolk phosphatidylcholine (PC) to characterize the extent of insertion of the protein into phospholipid bilayers. The parameters...... for the interaction of SP-B with DPPC or PC using different reconstitution protocols have been estimated from the changes induced in the fluorescence emission spectrum of the single protein tryptophan. All the different reconstituted SP-B-phospholipid preparations studied had similar Kd values for the binding....... These differences in the extent of insertion lead to qualitative and quantitative differences in the effect of the protein on the mobility of the phospholipid acyl chains, as studied by spin-label electron spin resonance (ESR) spectroscopy, and could represent different functional stages in the surfactant cycle...

  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. Kissing G domains of MnmE monitored by X-ray crystallography and pulse electron paramagnetic resonance spectroscopy.

    Directory of Open Access Journals (Sweden)

    Simon Meyer

    2009-10-01

    Full Text Available MnmE, which is involved in the modification of the wobble position of certain tRNAs, belongs to the expanding class of G proteins activated by nucleotide-dependent dimerization (GADs. Previous models suggested the protein to be a multidomain protein whose G domains contact each other in a nucleotide dependent manner. Here we employ a combined approach of X-ray crystallography and pulse electron paramagnetic resonance (EPR spectroscopy to show that large domain movements are coupled to the G protein cycle of MnmE. The X-ray structures show MnmE to be a constitutive homodimer where the highly mobile G domains face each other in various orientations but are not in close contact as suggested by the GDP-AlF(x structure of the isolated domains. Distance measurements by pulse double electron-electron resonance (DEER spectroscopy show that the G domains adopt an open conformation in the nucleotide free/GDP-bound and an open/closed two-state equilibrium in the GTP-bound state, with maximal distance variations of 18 A. With GDP and AlF(x, which mimic the transition state of the phosphoryl transfer reaction, only the closed conformation is observed. Dimerization of the active sites with GDP-AlF(x requires the presence of specific monovalent cations, thus reflecting the requirements for the GTPase reaction of MnmE. Our results directly demonstrate the nature of the conformational changes MnmE was previously suggested to undergo during its GTPase cycle. They show the nucleotide-dependent dynamic movements of the G domains around two swivel positions relative to the rest of the protein, and they are of crucial importance for understanding the mechanistic principles of this GAD.

  5. MDM2–MDM4 molecular interaction investigated by atomic force spectroscopy and surface plasmon resonance

    Directory of Open Access Journals (Sweden)

    Moscetti I

    2016-08-01

    Full Text Available Ilaria Moscetti,1 Emanuela Teveroni,2,3 Fabiola Moretti,3 Anna Rita Bizzarri,1 Salvatore Cannistraro1 1Biophysics and Nanoscience Centre, Department DEB, Università della Tuscia, Viterbo, Italy; 2Department of Endocrinology and Metabolism, Università Cattolica di Roma, Roma, Italy; 3Institute of Cell Biology and Neurobiology, Consiglio Nazionale delle Ricerche (CNR, Roma, Italy Abstract: 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. Keywords: MDM2, MDM4, atomic force spectroscopy, surface plasmon resonance

  6. Characterization of the AT180 epitope of phosphorylated Tau protein by a combined nuclear magnetic resonance and fluorescence spectroscopy approach

    Energy Technology Data Exchange (ETDEWEB)

    Amniai, Laziza [CNRS-UMR 8576 UGSF-IFR 147, Universite des Sciences et Technologies de Lille 1, 59655 Villeneuve d' Ascq Cedex (France); Lippens, Guy, E-mail: guy.lippens@univ-lille1.fr [CNRS-UMR 8576 UGSF-IFR 147, Universite des Sciences et Technologies de Lille 1, 59655 Villeneuve d' Ascq Cedex (France); Landrieu, Isabelle, E-mail: isabelle.landrieu@univ-lille1.fr [CNRS-UMR 8576 UGSF-IFR 147, Universite des Sciences et Technologies de Lille 1, 59655 Villeneuve d' Ascq Cedex (France)

    2011-09-09

    Highlights: {yields} pThr231 of the Tau protein is necessary for the binding of the AT180 antibody. {yields} pSer235 of the Tau protein does not interfere with the AT180 recognition of pThr231. {yields} Epitope mapping is efficiently achieved by combining NMR and FRET spectroscopy. -- Abstract: We present here the characterization of the epitope recognized by the AT180 monoclonal antibody currently used to define an Alzheimer's disease (AD)-related pathological form of the phosphorylated Tau protein. Some ambiguity remains as to the exact phospho-residue(s) recognized by this monoclonal: pThr231 or both pThr231 and pSer235. To answer this question, we have used a combination of nuclear magnetic resonance (NMR) and fluorescence spectroscopy to characterize in a qualitative and quantitative manner the phospho-residue(s) essential for the epitope recognition. Data from the first step of NMR experiments are used to map the residues bound by the antibodies, which were found to be limited to a few residues. A fluorophore is then chemically attached to a cystein residue introduced close-by the mapped epitope, at arginine 221, by mutagenesis of the recombinant protein. The second step of Foerster resonance energy transfer (FRET) between the AT180 antibody tryptophanes and the phospho-Tau protein fluorophore allows to calculate a dissociation constant Kd of 30 nM. We show that the sole pThr231 is necessary for the AT180 recognition of phospho-Tau and that phosphorylation of Ser235 does not interfere with the binding.

  7. Assessment of Anterior Cingulate Cortex (ACC) and Left Cerebellar Metabolism in Asperger's Syndrome with Proton Magnetic Resonance Spectroscopy (MRS)

    Science.gov (United States)

    Goji, Aya; Ito, Hiromichi; Mori, Kenji; Harada, Masafumi; Hisaoka, Sonoka; Toda, Yoshihiro; Mori, Tatsuo; Abe, Yoko; Miyazaki, Masahito; Kagami, Shoji

    2017-01-01

    Purpose Proton magnetic resonance spectroscopy (1H MRS) is a noninvasive neuroimaging method to quantify biochemical metabolites in vivo and it can serve as a powerful tool to monitor neurobiochemical profiles in the brain. Asperger’s syndrome (AS) is a type of autism spectrum disorder, which is characterized by impaired social skills and restrictive, repetitive patterns of interest and activities, while intellectual levels and language skills are relatively preserved. Despite clinical aspects have been well-characterized, neurometabolic profiling in the brain of AS remains to be clear. The present study used proton magnetic resonance spectroscopy (1H MRS) to investigate whether pediatric AS is associated with measurable neurometabolic abnormalities that can contribute new information on the neurobiological underpinnings of the disorder. Methods Study participants consisted of 34 children with AS (2–12 years old; mean age 5.2 (±2.0); 28 boys) and 19 typically developed children (2–11 years old; mean age 5.6 (±2.6); 12 boys) who served as the normal control group. The 1H MRS data were obtained from two regions of interest: the anterior cingulate cortex (ACC) and left cerebellum. Results In the ACC, levels of N-acetylaspartate (NAA), total creatine (tCr), total choline-containing compounds (tCho) and myo-Inositol (mI) were significantly decreased in children with AS compared to controls. On the other hand, no significant group differences in any of the metabolites were found in the left cerebellum. Neither age nor sex accounted for the metabolic findings in the regions. Conclusion The finding of decreased levels of NAA, tCr, tCho, and mI in the ACC but not in left cerebellar voxels in the AS, suggests a lower ACC neuronal density in the present AS cohort compared to controls. PMID:28060873

  8. Kissing G domains of MnmE monitored by X-ray crystallography and pulse electron paramagnetic resonance spectroscopy.

    Science.gov (United States)

    Meyer, Simon; Böhme, Sabine; Krüger, André; Steinhoff, Heinz-Jürgen; Klare, Johann P; Wittinghofer, Alfred

    2009-10-01

    MnmE, which is involved in the modification of the wobble position of certain tRNAs, belongs to the expanding class of G proteins activated by nucleotide-dependent dimerization (GADs). Previous models suggested the protein to be a multidomain protein whose G domains contact each other in a nucleotide dependent manner. Here we employ a combined approach of X-ray crystallography and pulse electron paramagnetic resonance (EPR) spectroscopy to show that large domain movements are coupled to the G protein cycle of MnmE. The X-ray structures show MnmE to be a constitutive homodimer where the highly mobile G domains face each other in various orientations but are not in close contact as suggested by the GDP-AlF(x) structure of the isolated domains. Distance measurements by pulse double electron-electron resonance (DEER) spectroscopy show that the G domains adopt an open conformation in the nucleotide free/GDP-bound and an open/closed two-state equilibrium in the GTP-bound state, with maximal distance variations of 18 A. With GDP and AlF(x), which mimic the transition state of the phosphoryl transfer reaction, only the closed conformation is observed. Dimerization of the active sites with GDP-AlF(x) requires the presence of specific monovalent cations, thus reflecting the requirements for the GTPase reaction of MnmE. Our results directly demonstrate the nature of the conformational changes MnmE was previously suggested to undergo during its GTPase cycle. They show the nucleotide-dependent dynamic movements of the G domains around two swivel positions relative to the rest of the protein, and they are of crucial importance for understanding the mechanistic principles of this GAD.

  9. Chemistry of paramagnetic and diamagnetic contrast agents for Magnetic Resonance Imaging and Spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Perez-Mayoral, Elena [Laboratorio de Sintesis Organica e Imagen Molecular por Resonancia Magnetica, Facultad de Ciencias, UNED, Paseo Senda del Rey 9, E-28040 Madrid (Spain); Departamento de Quimica Inorganica y Quimica Tecnica, Facultad de Ciencias, UNED, Paseo Senda del Rey 9, E-28040 Madrid (Spain); Negri, Viviana; Soler-Padros, Jordi [Laboratorio de Sintesis Organica e Imagen Molecular por Resonancia Magnetica, Facultad de Ciencias, UNED, Paseo Senda del Rey 9, E-28040 Madrid (Spain); Cerdan, Sebastian [Laboratorio de Imagen Espectroscopica por Resonancia Magnetica (LIERM), Instituto de Investigaciones Biomedicas ' Alberto Sols' , CSIC/UAM, c/Arturo Duperier 4, E-28029 Madrid (Spain); Ballesteros, Paloma [Laboratorio de Sintesis Organica e Imagen Molecular por Resonancia Magnetica, Facultad de Ciencias, UNED, Paseo Senda del Rey 9, E-28040 Madrid (Spain)], E-mail: pballesteros@ccia.uned.es

    2008-09-15

    We provide a brief overview of the chemistry and most relevant properties of paramagnetic and diamagnetic contrast agents (CAs) for Magnetic Resonance Imaging and Magnetic Resonance Spectroscopic Imaging. Paramagnetic CAs for MRI consist mainly of Gd(III) complexes from linear or macrocyclic polyaminopolycarboxylates. These agents reduce, the relaxation times T{sub 1} and T{sub 2} of the water protons in a concentration dependent manner, increasing selectively MRI contrast in those regions in which they accumulate. In most instances they provide anatomical information on the localization of lesions and in some specific cases they may allow to estimate some physiological properties of tissues including mainly vascular performance. Because of its ability to discriminate easily between normal and diseased tissue, extracellular pH (pH{sub e}) has been added recently, to the battery of variables amenable to MRI investigation. A variety of Gd(III) containing macrocycles sensitive to pH, endogenous or exogenous polypeptides or even liposomes have been investigated for this purpose, using the pH dependence of their relaxivity or magnetization transfer rate constant (chemical exchange saturation transfer, CEST). Many environmental circumstances in addition to pH affect, however, relaxivity or magnetization transfer rate constants of these agents, making the results of pH measurements by MRI difficult to interpret. To overcome these limitations, our laboratory synthesized and developed a novel series of diamagnetic CAs for Magnetic Resonance Spectroscopic Imaging, a new family of monomeric and dimeric imidazolic derivatives able to provide unambiguous measurements of pH{sub e}, independent of water relaxivity, diffusion or exchange.

  10. Double resonance capacitance spectroscopy (DORCAS): A new experimental technique for assignment of X-ray absorption peaks to surface sites of semiconductor

    CERN Document Server

    Ishii, M

    2003-01-01

    As a new microspectroscopy for semiconductor surface analysis using an X-ray beam, double resonance capacitance spectroscopy (DORCAS) is proposed. For a microscopic X-ray absorption measurement, a local capacitance change owing to X-ray induced emission of localized electrons is detected by a microprobe. The applied bias voltage V sub b dependence of the capacitance also provides information on the surface density of state. The resonance of the Fermi energy with a surface level by V sub b control makes possible the selection of the observable surface site in the X-ray absorption measurements, i.e. site-specific spectroscopy. The double resonance of the surface site selection (V sub b resonance) and the resonant X-ray absorption of the selected site (photon energy h nu resonance) enhances the capacitance signal. The DORCAS measurement of the GaAs surface shows correlation peaks at h nu=10.402 keV and V sub b =-0.4 V and h nu=10.429 keV and V sub b =+0.1 V, indicating that these resonant X-ray absorption peaks ...

  11. Combining Nuclear Magnetic Resonance Spectroscopy and Density Functional Theory Calculations to Characterize Carvedilol Polymorphs.

    Science.gov (United States)

    Rezende, Carlos A; San Gil, Rosane A S; Borré, Leandro B; Pires, José Ricardo; Vaiss, Viviane S; Resende, Jackson A L C; Leitão, Alexandre A; De Alencastro, Ricardo B; Leal, Katia Z

    2016-09-01

    The experiments of carvedilol form II, form III, and hydrate by (13)C and (15)N cross-polarization magic-angle spinning (CP MAS) are reported. The GIPAW (gauge-including projector-augmented wave) method from DFT (density functional theory) calculations was used to simulate (13)C and (15)N chemical shifts. A very good agreement was found for the comparison between the global results of experimental and calculated nuclear magnetic resonance (NMR) chemical shifts for carvedilol polymorphs. This work aims a comprehensive understanding of carvedilol crystalline forms employing solution and solid-state NMR as well as DFT calculations.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1994-04-01

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

  13. Pulsed electron-electron double resonance (PELDOR) as EPR spectroscopy in nanometre range

    Energy Technology Data Exchange (ETDEWEB)

    Tsvetkov, Yu D; Milov, A D; Maryasov, A G [Institute of Chemical Kinetics and Combustion, Siberian Branch of the Russian Academy of Sciences, Novosibirsk (Russian Federation)

    2008-06-30

    The results of development of pulsed electron-electron double resonance (PELDOR) method and its applications in structural studies are generalised and described systematically. The foundations of the theory of the method are outlined, some methodological features and applications are considered, in particular, determination of the distances between spin labels in the nanometre range for iminoxyl biradicals, spin-labelled biomacromolecules, radical ion pairs and peptide-membrane complexes. The attention is focussed on radical systems that form upon self-assembly of nanosized complexes (in particular, peptide complexes), spatial effects, and radical pairs in photolysis and photosynthesis. The position of PELDOR among other structural EPR techniques is analysed.

  14. Coupled analysis of high and low frequency resonant ultrasound spectroscopy: Application to the detection of defects in ceramic balls

    Energy Technology Data Exchange (ETDEWEB)

    Deneuville, Francois; Duquennoy, Marc; Ouaftouh, Mohammadi; Jenot, Frederic; Ourak, Mohamed [IEMN-DOAE (UMR CNRS 8520), Universite de Valenciennes, 59313 Valenciennes cedex 9 (France); Desvaux, Sebastien [SKF Aeroengine France, Z. I. no. 2, Rouvignies, 59309 Valenciennes (France)

    2009-05-15

    A coupled analysis of high and low frequency resonant ultrasound spectroscopy of spheroidal modes is presented in this paper. Experimentally, by using an ultrasonic probe for the excitation (piezoelectric transducer) and a heterodyne optic probe for the receiver (interferometer), it was possible to take spectroscopic measurements of spheroidal vibrations over a large frequency range of 100 kHz-45 MHz in a continuous regime. This wide analysis range enabled variations in velocity due to the presence of defects to be differentiated from the inherent characteristics of the balls and consequently, it offers the possibility of detecting cracks independently of production variations. This kind of defect is difficult to detect because the C-shaped surface crack is very small and narrow (500x5 {mu}m{sup 2}), and its depth does not exceed 50 {mu}m. The proposed methodology can excite spheroidal vibrations in the ceramic balls and detect such vibrations over a large frequency range. On the one hand, low frequency resonances are used in order to estimate the elastic coefficients of the balls according to various inspection depths. This method has the advantage of providing highly accurate evaluations of the elastic coefficients over a wide frequency range. On the other hand, high frequency vibrations are considered because they are similar to the surface waves propagating in the surface zone of the ceramic balls and consequently can be used to detect C-crack defects.

  15. Joseph F. Keithley Award For Advances in Measurement Science: Resonant Ultrasound Spectroscopy: An Odyssey in Measurement Science

    Science.gov (United States)

    Migliori, Albert

    Perhaps the speeds of sound, or, equivalently, the elastic moduli are some of the most fundamental attributes of a solid, connecting to fundamental physics, metallurgy, non-destructive testing, and more. Unlike most of the quantities used to characterize condensed matter, the elastic moduli are fourth-rank tensors containing a wealth of detail, directional information, and consistency constraints that provide some of the most revealing probes of solids. We describe here the current state of the art in one method, Resonant Ultrasound Spectroscopy, where the mechanical resonances of a specimen of regular shape (easy to measure) are analyzed (difficult computational problem) to obtain the full elastic tensor. With modern advances in electronics and analysis, fractions of a part per million changes in elastic moduli are detectable providing new and important insight into grand challenges in condensed matter physics. This work was supported as part of the Materials Science of Actinides, an Energy Frontier Research Center funded by the U.S. Department of Energy, Office of Science, Basic Energy Sciences under Award # DE-SC0001089.

  16. 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.

  17. Resonant photoelectron spectroscopy of γ-Al{sub 2}O{sub 3}/SrTiO{sub 3} heterostructures

    Energy Technology Data Exchange (ETDEWEB)

    Schuetz, Philipp; Pfaff, Florian; Zapf, Michael; Gabel, Judith; Dudy, Lenart; Berner, Goetz; Sing, Michael; Claessen, Ralph [Wuerzburg Univ. (Germany). Physikalisches Inst. and Roentgen Center for Complex Material Systems (RCCM); Chen, Yunzhong; Pryds, Nini [Technical Univ. of Denmark, Risoe (Denmark). Dept. of Energy Conversion and Storage; Rogalev, Victor; Strocov, Vladimir [Paul Scherrer Institut, Villigen (Switzerland). Swiss Light Source; Schlueter, Christoph; Lee, Tien-Lin [Diamond Light Source Ltd., Didcot (United Kingdom)

    2015-07-01

    The spinel/perovskite heterointerface between the band insulators γ-Al{sub 2}O{sub 3} and SrTiO{sub 3} hosts a two-dimensional electron system (2DES) with exceptionally high electron mobility. Soft X-ray resonant photoelectron spectroscopy at the Ti L absorption edge is used to probe the Ti 3d derived interface states. Marked differences in the resonance behavior are found for the SrTiO{sub 3} valence band and the different interface states, which are observed in the band gap of SrTiO{sub 3}. A comparison to X-ray absorption spectra of Ti 3d{sup 0} and Ti 3d{sup 1} systems reveals the presence of different types of electronic states with Ti 3d character, i.e., oxygen vacancy induced, trapped in-gap states and itinerant states contributing to the 2DES. Furthermore, exposure to low doses of oxygen during irradiation allows for the controlled and reversible manipulation of the interfacial electronic structure, i.e., the in-gap state intensity and the valence band offset between SrTiO{sub 3} and γ-Al{sub 2}O{sub 3}.

  18. Magnetic Resonance Spectroscopy and Single-Photon Emission Computed Tomography in the Evaluation of Cerebral Tumors: A Case Report

    Science.gov (United States)

    Siasios, Ioannis; Valotassiou, Varvara; Kapsalaki, Eftychia; Tsougos, Ioannis; Georgoulias, Panagiotis; Fotiadou, Aggeliki; Ioannou, Maria; Koukoulis, Georgios; Dimopoulos, Vassilios; Fountas, Kostas

    2017-01-01

    In their daily clinical practice, physicians have to confront diagnostic dilemmas which cannot be resolved by the application of only one imaging technique. In this case report, we present a 66-year-old woman who was admitted to our institution for the surgical resection of a recently diagnosed brain tumor. The patient had a history of epileptic seizures and was hospitalized in the past for anti-phospholipid syndrome related to a non-Hodgkin lymphoma in remission. Magnetic resonance imaging (MRI) examination revealed an enhancing right parasagittal lesion with significant edema suggestive of a high grade glioma. Advanced MRI techniques including proton magnetic resonance spectroscopy (1H-MRS) showed findings compatible of glioma. An additional examination was performed as part of a protocol that we are routinely performing in our institution for all brain tumors including not only the gold standard advanced MRI techniques but also single-photon emission computed tomography (SPECT) with technetium-99m (Tc99m). Brain SPECT indicated the presence of a meningioma which was verified by the histopathology of the resected specimen. In conclusion, a multimodality approach for the pre-surgical assessment of brain tumors has significant advantages not only for the diagnosis but also for the evaluation of intracranial tumors histology. PMID:27924180

  19. 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.

  20. Two-dimensional electron paramagnetic resonance spectroscopy of nitroxides: Elucidation of restricted molecular motions in glassy solids

    Science.gov (United States)

    Dubinskii, Alexander A.; Maresch, Günter G.; Spiess, Hans-Wolfgang

    1994-02-01

    The combination of concepts of two-dimensional (2D) spectroscopy with the well-known field step electron-electron double resonance (ELDOR) method offers a practical route to recording 2D ELDOR spectra covering the full spectral range needed for electron paramagnetic resonance (EPR) of nitroxide spin labels in the solid state. The 2D ELDOR pattern provides information about molecular reorientation measured in real time, the anisotropies of electron phase, and electron spin-lattice relaxation as well as nuclear spin-lattice relaxation all of which are connected with the detailed geometry of the molecular reorientation. Thus, in 2D ELDOR the same electron spin probes the motional behavior over a wide range of correlation times from 10-4 to 10-12 s. An efficient algorithm for simulating 2D ELDOR spectra is derived, based on analytical solutions of the spin relaxation behavior for small-angle fluctuations and offers a means of quantitatively analyzing experimental data. As an example, the motion of nitroxide spin labels in a liquid-crystalline side-group polymer well below its glass transition is determined as a β-relaxation process with a mean angular amplitude of 5° and a distribution of correlation times with a mean correlation time of 0.9×10-10 s and a width of 2.5 decades.

  1. Characterization of Full Set Material Constants and Their Temperature Dependence for Piezoelectric Materials Using Resonant Ultrasound Spectroscopy.

    Science.gov (United States)

    Tang, Liguo; Cao, Wenwu

    2016-04-27

    During the operation of high power electromechanical devices, a temperature rise is unavoidable due to mechanical and electrical losses, causing the degradation of device performance. In order to evaluate such degradations using computer simulations, full matrix material properties at elevated temperatures are needed as inputs. It is extremely difficult to measure such data for ferroelectric materials due to their strong anisotropic nature and property variation among samples of different geometries. Because the degree of depolarization is boundary condition dependent, data obtained by the IEEE (Institute of Electrical and Electronics Engineers) impedance resonance technique, which requires several samples with drastically different geometries, usually lack self-consistency. The resonant ultrasound spectroscopy (RUS) technique allows the full set material constants to be measured using only one sample, which can eliminate errors caused by sample to sample variation. A detailed RUS procedure is demonstrated here using a lead zirconate titanate (PZT-4) piezoceramic sample. In the example, the complete set of material constants was measured from room temperature to 120 °C. Measured free dielectric constants and  were compared with calculated ones based on the measured full set data, and piezoelectric constants d15 and d33 were also calculated using different formulas. Excellent agreement was found in the entire range of temperatures, which confirmed the self-consistency of the data set obtained by the RUS.

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

    Institute of Scientific and Technical Information of China (English)

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

    2015-01-01

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

  3. ¹H magnetic resonance spectroscopy: a review of the current literature and its potential utility in veterinary oncology.

    Science.gov (United States)

    Lynch, Katherine; O'Brien, Robert

    2014-05-01

    Advanced imaging of veterinary cancer patients has evolved in recent years and modalities once limited to human medicine have now been described for diagnostic purposes in veterinary medicine (positron emission tomography/computed tomography, single-photon emission computed tomography, whole body magnetic resonance imaging). Magnetic resonance spectroscopy (MRS) is a non-invasive and non-ionizing technique that is well described in the human medical literature and is most frequently used to evaluate the metabolic activity of tissues with questionable malignant transformation. Differentiation of neoplastic tissue from surrounding normal tissue is dependent on variations in cellular metabolism. Positive identification of malignancy can be made when neoplastic alterations are occurring at the cellular level prior to gross anatomic changes. This improved, early detection of cancer occurrence (or recurrence) can improve patient survival and direct medical therapy. MRS techniques are largely underutilized in veterinary medicine, with current research predominantly limited to the brain (both evaluation of normal and diseased tissue). Given the clinical utility of MRS in humans, the technique may also be useful in the staging of cancer in veterinary medicine.

  4. A no-tune no-match wideband probe for nuclear quadrupole resonance spectroscopy in the VHF range

    Science.gov (United States)

    Scharfetter, Hermann; Petrovic, Andreas; Eggenhofer, Heidi; Stollberger, Rudolf

    2014-12-01

    Nuclear quadrupole resonance (NQR) spectroscopy is a method for the characterization of chemical compounds containing so-called quadrupolar nuclei. Similar to nuclear magnetic resonance (NMR), the sample under investigation is irradiated with strong radiofrequency (RF) pulses, which stimulate the emission of weak RF signals from the quadrupolar nuclei. The signals are then amplified and Fourier transformed so as to obtain a spectrum. In principle, narrowband NQR spectra can be measured with NMR spectrometers. However, pure NQR signals require the absence of a static magnetic field and several special applications require the characterization of a substance over a large bandwidth, e.g. 50-100% of the central frequency, which is hardly possible with standard NMR equipment. Dedicated zero-field NQR equipment is not widespread and current concepts employ resonating probes which are tuned and matched over a wide range by using mechanical capacitors driven by stepper motors. While providing the highest signal to noise ratio (SNR) such probes are slow in operation and can only be operated from dedicated NMR consoles. We developed a low-cost NQR wideband probe without tuning and matching for applications in the very high frequency (VHF) range below 300 MHz. The probe coil was realized as part of a reactive network which approximates an exponential transmission line. The input reflection coefficient of the two developed prototype probe coils is ≤ 20 dB between 90-145 MHz and 74.5-99.5 MHz, respectively. Two wideband NQR spectra of published test substances were acquired with an SNR of better than 20 dB after sufficient averaging. The measured signals and the SNR correspond very well to the theoretically expected values and demonstrate the feasibility of the method. Because there is no need for tuning and matching, our probes can be operated easily from any available NMR console.

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

    Institute of Scientific and Technical Information of China (English)

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

    2006-01-01

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

  6. Noninvasive measurement of brain glycogen by nuclear magnetic resonance spectroscopy and its application to the study of brain metabolism.

    Science.gov (United States)

    Tesfaye, Nolawit; Seaquist, Elizabeth R; Oz, Gülin

    2011-12-01

    Glycogen is the reservoir for glucose in the brain. Beyond the general agreement that glycogen serves as an energy source in the central nervous system, its exact role in brain energy metabolism has yet to be elucidated. Experiments performed in cell and tissue culture and animals have shown that glycogen content is affected by several factors, including glucose, insulin, neurotransmitters, and neuronal activation. The study of in vivo glycogen metabolism has been hindered by the inability to measure glycogen noninvasively, but, in the past several years, the development of a noninvasive localized (13) C nuclear magnetic resonance (NMR) spectroscopy method has allowed the study of glycogen metabolism in the conscious human. With this technique, (13) C-glucose is administered intravenously, and its incorporation into and washout from brain glycogen is tracked. One application of this method has been to the study of brain glycogen metabolism in humans during hypoglycemia: data have shown that mobilization of brain glycogen is augmented during hypoglycemia, and, after a single episode of hypoglycemia, glycogen synthesis rate is increased, suggesting that glycogen stores rebound to levels greater than baseline. Such studies suggest that glycogen may serve as a potential energy reservoir in hypoglycemia and may participate in the brain's adaptation to recurrent hypoglycemia and eventual development of hypoglycemia unawareness. Beyond this focused area of study, (13) C NMR spectroscopy has a broad potential for application in the study of brain glycogen metabolism and carries the promise of a better understanding of the role of brain glycogen in diabetes and other conditions.

  7. A study on the Fermi resonance of phenol under the effects of pressure and temperature by Raman spectroscopy.

    Science.gov (United States)

    Li, DongFei; Hua, Zhong; Liu, ChengZhi; Fan, Cunbo; Sun, ChengLin; Li, ZuoWei; Chen, WanJin

    2015-02-05

    The ν1-ν18a Fermi resonance (FR) of phenol were investigated by pressure-dependent Raman spectroscopy from atmospheric up to P=15.2GPa and temperature-dependent Raman spectroscopy from 40 down to T=-180°C, respectively. In the case of pressure, we found the Fermi coupling coefficient W, which were calculated based on the FR theory, exposed a value turnover between 1.912 and 2.244GPa in the process of increasing the pressure. This turnover phenomenon of the Fermi coupling coefficient W has been ascribed to the crystal structure of phenol evolving towards a more symmetric structure with pressure, from a structure like a pseudo-threefold helical chain at ambient pressure to like a ribbon arrangement at 1.912GPa, then to adopt a herringbone arrangement at much higher pressure. On the other hand, we also found the Fermi coupling coefficient W exhibited monotonic reduction without turnover points appearing by decreasing the temperature. The tendencies of the Fermi coupling coefficient W with temperature were in good agreement with the pressure dependence of the Fermi coupling coefficient W in the region of ambient to 1.912GPa, indicating that the effect of pressure and temperature on the FR of phenol in this region might be the same. A conformation evolving induced by pressure and temperature on the ν1 and ν18a FR of phenol have been analyzed.

  8. Structural and dynamic properties of amorphous solid dispersions: the role of solid-state nuclear magnetic resonance spectroscopy and relaxometry.

    Science.gov (United States)

    Paudel, Amrit; Geppi, Marco; Van den Mooter, Guy

    2014-09-01

    Amorphous solid dispersions (ASDs) are one of the frontier strategies to improve solubility and dissolution rate of poorly soluble drugs and hence tackling the growing challenges in oral bioavailability. Pharmaceutical performance, physicochemical stability, and downstream processability of ASD largely rely on the physical structure of the product. This necessitates in-depth characterization of ASD microstructure. Solid-state nuclear magnetic resonance (SS-NMR) techniques bear the ultimate analytical capabilities to provide the molecular level information on the dynamics and phase compositions of amorphous dispersions. SS-NMR spectroscopy/relaxometry, as a single and nondestructive technique, can reveal diverse and critical structural information of complex ASD formulations that are barely amenable from any other existing technique. The purpose of the current article is to review the recent most important studies on various sophisticated and information-rich one-dimensional and two-dimensional SS-NMR spectroscopy/relaxometry for the analysis of molecular mobility, miscibility, drug-carrier interactions, crystallinity, and crystallization in ASD. Some specific examples on microstructural elucidations of challenging ASD using multidimensional and multinuclear SS-NMR are presented. Additionally, some relevant examples on the utility of solution-NMR and NMR-imaging techniques for the investigation of the dissolution behavior of ASD are gathered.

  9. Spatial location of indomethacin associated with unimeric amphiphilic carrier macromolecules as determined by nuclear magnetic resonance spectroscopy.

    Science.gov (United States)

    Orban, David E; Moretti, Alysha; Uhrich, Kathryn E

    2016-07-01

    A combination of nuclear magnetic resonance (NMR) techniques including, proton NMR, relaxation analysis, two-dimensional nuclear Overhauser effect spectroscopy, and diffusion-ordered spectroscopy, has been used to demonstrate the spatial location of indomethacin within a unimolecular micelle. Understanding the location of drugs within carrier molecules using such NMR techniques can facilitate rational carrier design. In addition, this information provides insight to encapsulation efficiency of different drugs to determine the most efficient system for a particular bioactive. This study demonstrates that drugs loaded by the unimolecular amphiphile under investigation are not necessarily encapsulated but reside or localize to the periphery or interfacial region of the carrier molecule. The results have further implications as to the features of the unimolecular carrier that contribute to drug loading. In addition, evidence of drug retention associated with the unimolecular surfactant is possible in organic media, as well as in an aqueous environment. Such findings have implications for rational carrier design to correlate the carrier features to the drug of interest and indicate the strong retention capabilities of the unimolecular micelle for delivery applications. Copyright © 2016 John Wiley & Sons, Ltd.

  10. Definition of the intermediates and mechanism of the anticancer drug bleomycin using nuclear resonance vibrational spectroscopy and related methods

    Science.gov (United States)

    Liu, Lei V.; Bell, Caleb B.; Wong, Shaun D.; Wilson, Samuel A.; Kwak, Yeonju; Chow, Marina S.; Zhao, Jiyong; Hodgson, Keith O.; Hedman, Britt; Solomon, Edward I.

    2010-01-01

    Bleomycin (BLM) is a glycopeptide anticancer drug capable of effecting single- and double-strand DNA cleavage. The last detectable intermediate prior to DNA cleavage is a low spin FeIII peroxy level species, termed activated bleomycin (ABLM). DNA strand scission is initiated through the abstraction of the C-4′ hydrogen atom of the deoxyribose sugar unit. Nuclear resonance vibrational spectroscopy (NRVS) aided by extended X-ray absorption fine structure spectroscopy and density functional theory (DFT) calculations are applied to define the natures of FeIIIBLM and ABLM as (BLM)FeIII─OH and (BLM)FeIII(η1─OOH) species, respectively. The NRVS spectra of FeIIIBLM and ABLM are strikingly different because in ABLM the δFe─O─O bending mode mixes with, and energetically splits, the doubly degenerate, intense O─Fe─Nax transaxial bends. DFT calculations of the reaction of ABLM with DNA, based on the species defined by the NRVS data, show that the direct H-atom abstraction by ABLM is thermodynamically favored over other proposed reaction pathways. PMID:21149675

  11. Optical frequency comb spectroscopy at 3-5.4 {\\mu}m with a doubly resonant optical parametric oscillator

    CERN Document Server

    Khodabakhsh, Amir; Rutkowski, Lucile; Johansson, Alexandra C; Lee, Kevin F; Jiang, Jie; Mohr, Christian; Fermann, Martin E; Foltynowicz, Aleksandra

    2016-01-01

    We present a versatile mid-infrared frequency comb spectroscopy system based on a doubly resonant optical parametric oscillator tunable in the 3-5.4 {\\mu}m range and two detection methods, a Fourier transform spectrometer (FTS) and a Vernier spectrometer. Using the FTS with a multipass cell we measure high-precision broadband absorption spectra of CH$_4$ and NO at ~3.3 {\\mu}m and ~5.2 {\\mu}m, respectively, and of atmospheric species (CH$_4$, CO, CO$_2$ and H$_2$O) in air in the signal and idler wavelength range. The figure of merit of the system is on the order of 10$^{-8}$ cm$^{-1}$ Hz$^{-1/2}$ per spectral element, and multiline fitting yields minimum detectable concentrations of 10-20 ppb Hz$^{-1/2}$ for CH$_4$, NO and CO. For the first time in the mid-infrared, we perform continuous-filtering Vernier spectroscopy using a low finesse enhancement cavity, a grating and a single detector, and measure the absorption spectrum of CH$_4$ and H$_2$O in ambient air at ~3.3 {\\mu}m.

  12. Early Detection of Myocardial Bioenergetic Deficits: A 9.4 Tesla Complete Non Invasive 31P MR Spectroscopy Study in Mice with Muscular Dystrophy.

    Directory of Open Access Journals (Sweden)

    Weina Cui

    Full Text Available Duchenne muscular dystrophy (DMD is the most common fatal form of muscular dystrophy characterized by striated muscle wasting and dysfunction. Patients with DMD have a very high incidence of heart failure, which is increasingly the cause of death in DMD patients. We hypothesize that in the in vivo system, the dystrophic cardiac muscle displays bioenergetic deficits prior to any functional or structural deficits. To address this we developed a complete non invasive 31P magnetic resonance spectroscopy (31P MRS approach to measure myocardial bioenergetics in the heart in vivo.Six control and nine mdx mice at 5 months of age were used for the study. A standard 3D -Image Selected In vivo Spectroscopy (3D-ISIS sequence was used to provide complete gradient controlled three-dimensional localization for heart 31P MRS. These studies demonstrated dystrophic hearts have a significant reduction in PCr/ATP ratio compare to normal (1.59±0.13 vs 2.37±0.25, p<0.05.Our present study provides the direct evidence of significant cardiac bioenergetic deficits in the in vivo dystrophic mouse. These data suggest that energetic defects precede the development of significant hemodynamic or structural changes. The methods provide a clinically relevant approach to use myocardial energetics as an early marker of disease in the dystrophic heart. The new method in detecting the in vivo bioenergetics abnormality as an early non-invasive marker of emerging dystrophic cardiomyopathy is critical in management of patients with DMD, and optimized therapies aimed at slowing or reversing the cardiomyopathy.

  13. Metabolic profile of different Italian cultivars of hazelnut (Corylus avellana) by nuclear magnetic resonance spectroscopy.

    Science.gov (United States)

    Sciubba, Fabio; Di Cocco, Maria Enrica; Gianferri, Raffaella; Impellizzeri, Danilo; Mannina, Luisa; De Salvador, Flavio Roberto; Venditti, Alessandro; Delfini, Maurizio

    2014-01-01

    High-resolution proton NMR spectroscopy was performed on three Italian hazelnut cultivars, Tonda di Giffoni, Mortarella and Tonda Gentile Romana, and it allowed to define their metabolic profile. The hazelnuts were grown in the same pedoclimatic conditions in the Monti Cimini (Latium) area. The samples were obtained by using a modified Bligh-Dyer extraction protocol which did not give rise to artefacts arising from the demolition of macromolecular structures such as proteins and polysaccharides. Metabolites belonging to different chemical classes (amino acids, organic acids, carbohydrates, lipids and miscellaneous compounds) were identified and quantified. The three cultivars were discriminated by means of univariate (ANOVA) and multivariate (PCA) statistical analysis.

  14. Studying phase structure of burned ferrous manganese ores by method of nuclear gamma-resonance spectroscopy

    Directory of Open Access Journals (Sweden)

    B. Shayakhmetov

    2014-04-01

    Full Text Available In the given article there are presented the results of studying the phase structure of burned ferrous manganese ores of Zhomart and Zapadny Kamys deposits of by the method of Mossbauer spectroscopy. There is established a variety of iron location forms in the studied materials and their quantitative content that allows to define the degree of completing regenerative processes at magnetizing roasting, and also the processes of formation of solid solutions (Fe1-XMX3O4 and stabilization of Fe1-XO from eutectoid disintegration at cooling.

  15. Relaxation in the glass former acetylsalicylic acid studied by deuteron magnetic resonance and dielectric spectroscopy

    Science.gov (United States)

    Nath, R.; El Goresy, T.; Geil, B.; Zimmermann, H.; Böhmer, R.

    2006-08-01

    Supercooled liquid and glassy acetylsalicylic acid was studied using dielectric spectroscopy and deuteron relaxometry in a wide temperature range. The supercooled liquid is characterized by major deviations from thermally activated behavior. In the glass the secondary relaxation exhibits the typical features of a Johari-Goldstein process. Via measurements of spin-lattice relaxation times the selectively deuterated methyl group was used as a sensitive probe of its local environments. There is a large difference in the mean activation energy in the glass with respect to that in crystalline acetylsalicylic acid. This can be understood by taking into account the broad energy barrier distribution in the glass.

  16. The examination of cardiac metabolism of patients with hypercholesterolemia by phosphorus-31 magnetic resonance spectroscopy

    CERN Document Server

    Martinek, M

    2001-01-01

    Objectives: we decided to investigate weather alterations in high energy phosphates occur in the myocardium of persons with hypercholesterolemia. Background: myocardial high energy phosphates have been shown to be reduced in various diseases of the heart such as coronary artery disease, heart failure and dilated cardiomyopathy. The latest studies on hypercholesterolemia show direct effects of high serum cholesterol on heart muscle cells, so do studies on statins. Methods: in the present study 32 male patients (mean age 48) with hypercholesterolemia and 27 male healthy volunteers (mean age 44,5) as age matched controls were included. The patients were divided into a statin-treated (n = 17) and an untreated subgroup (n = 15). Using a 1,5 Tesla whole-body magnetic resonance scanner (Siemens, Germany) phosphor-31 magnetic resonance spectroscopic imaging (31P MRSI) of the heart was performed in all subjects. The 31P MRSI slab (slab thickness = 40 mm, field of view = 320 mm, matrix 32 x 32, TR = 323 ms, TE 3 ms) co...

  17. Site-selective resonant Auger spectroscopy of iso-dichloroethylene at the carbon K-edge

    Energy Technology Data Exchange (ETDEWEB)

    Ceolin, D.; Travnikova, O. [Department of Physics and Astronomy, Uppsala University, SE-75120 Uppsala (Sweden); Synchrotron SOLEIL, l' Orme des Merisiers, Saint-Aubin, FR-91192 Gif-sur-Yvette Cedex (France); Bao, Z. [Department of Physics and Astronomy, Uppsala University, SE-75120 Uppsala (Sweden); Guimaraes, F.F.; Costa, M.S. da [Institute of Chemistry, Federal University of Goias, CP 131 CEP 74001-970 Goiania, GO (Brazil); Velkov, Y. [Theoretische Chemie, PCI, Universitaet Heidelberg, Im Neuenheimer Feld 229, 69120 Heidelberg (Germany); Sisourat, N.; Carniato, S.; Simon, M. [Universite Pierre et Marie Curie, Laboratoire de Chimie Physique, Matiere et Rayonnement (UMR7614), FR-75231 Paris Cedex 05 (France); Centre National de la Recherche Scientifique, Laboratoire de Chimie Physique, Matiere et Rayonnement (UMR7614), FR-75231 Paris Cedex 05 (France); Piancastelli, M.N., E-mail: Maria-Novella.Piancastelli@fysik.uu.se [Department of Physics and Astronomy, Uppsala University, SE-75120 Uppsala (Sweden); Universite Pierre et Marie Curie, Laboratoire de Chimie Physique, Matiere et Rayonnement (UMR7614), FR-75231 Paris Cedex 05 (France); Centre National de la Recherche Scientifique, Laboratoire de Chimie Physique, Matiere et Rayonnement (UMR7614), FR-75231 Paris Cedex 05 (France)

    2012-09-15

    Highlights: Black-Right-Pointing-Pointer We provide detailed results on electron decay following core excitations to two carbon atoms to the LUMO in different chemical environments to the LUMO in CH{sub 2}=CCl{sub 2}. Black-Right-Pointing-Pointer The experimental results are compared with high-quality theoretical calculations. Black-Right-Pointing-Pointer We report calculated valence spectra in the ground-state, C (CH{sub 2}) and C (CCl{sub 2}) core-excited states. -- Abstract: This study focuses on the two C1s-to-LUMO (lowest unoccupied molecular orbital) excitations of the iso-dichloroethylene (H{sub 2}C=CCl{sub 2}) and the subsequent Auger decay. We investigate the effect of the two different carbon core excitations on the population of the cation produced after electronic relaxation. The resonant Auger spectra are interpreted by comparison to the valence shells photoionization spectrum and with the help of theoretical calculations. Several consequences of the core-hole localization on the electronic decay are observed. In particular, the resonant excitation of the C1s(CH{sub 2}) to the LUMO leads to a large intensity increase in the region of the first satellite state, whereas no dramatic changes are observed for the C1s(CCl{sub 2}) excitation.

  18. Investigating the phase-dependent photochemical reaction dynamics of chlorine dioxide using resonance Raman spectroscopy

    Science.gov (United States)

    Hayes, Sophia C.; Wallace, Paul M.; Bolinger, Josh C.; Reid, Philip J.

    Recent progress in understanding the phase-dependent reactivity demonstrated by halooxides is outlined. Specifically, resonance Raman intensity analysis (RRIA) and time-resolved resonance Raman (TRRR) studies of chlorine dioxide (OClO) photochemistry in solution are presented. Using RRIA, it has been determined that the excited-state structural evolution that occurs along the asymmetric-stretch coordinate in the gas phase is restricted in solution. The absence of evolution along this coordinate results in the preservation of groundstate symmetry in the excited state. The role of symmetry in defining the reaction coordinate and the solvent-solute interactions responsible for modification of the excited-state potential energy surface are discussed. TRRR studies are presented which demonstrate that geminate recombination of the primary photoproducts resulting in the reformation of ground-state OClO is a central feature of OClO photochemistry in solution. These studies also demonstrate that a fraction of photoexcited OClO undergoes photoisomerization to form ClOO, with the ground-state thermal decomposition of this species resulting in Cl production on the subnanosecond timescale. Finally, time-resolved anti-Stokes experiments are presented which demonstrate that the OClO vibrational-relaxation dynamics are solvent dependent. The current picture of OClO photochemistry derived from these studies is discussed, and future directions for study are outlined.

  19. Chemical shift magnetic resonance spectroscopy of cingulate grey matter in patients with minimal hepatic encephalopathy

    Energy Technology Data Exchange (ETDEWEB)

    Mechtcheriakov, Sergei; Kugener, Andre; Mattedi, Michael; Hinterhuber, Hartmann; Marksteiner, Josef [Innsbruck Medical University, Department of General Psychiatry, Innsbruck (Austria); Schocke, Michael [Innsbruck Medical University, Department of Radiology I, Innsbruck (Austria); Graziadei, Ivo W.; Vogel, Wolfgang [Innsbruck Medical University, Department of Gastroenterology, Innsbruck (Austria)

    2005-01-01

    Minimal hepatic encephalopathy (MHE) is frequently diagnosed in patients with liver cirrhosis who do not show overt clinical cirrhosis-associated neurological deficits. This condition manifests primarily with visuo-motor and attention deficits. We studied the association between visuo-motor deficits and magnetic resonance spectroscopic parameters in cingulate grey matter and white matter of centrum semiovale in patients with liver cirrhosis. The data revealed an increase in the glutamate-glutamine/creatine ratio and a decrease in choline/creatine and inositol/creatine ratios in patients with liver cirrhosis. The analysis of the data showed that cirrhosis-associated deterioration of the visuo-motor function significantly correlates with a decrease in the choline/creatine ratio and an increase in N-acetylaspartate/choline in cingulate grey matter but not in the neighbouring white matter. Furthermore, the increase in the glutamate-glutamine/creatine ratio correlated significantly with the increase in the N-acetylaspartate/creatine ratio. These data suggest an association between altered choline, glutamate-glutamine and NAA metabolism in cingulate grey matter and symptoms of MHE, and underline the importance of differentiation between grey and white matter in magnetic resonance spectroscopic studies on patients with cirrhosis-associated brain dysfunction. (orig.)

  20. A multiplexed high-resolution imaging spectrometer for resonant inelastic soft X-ray scattering spectroscopy.

    Science.gov (United States)

    Warwick, Tony; Chuang, Yi De; Voronov, Dmitriy L; Padmore, Howard A

    2014-07-01

    The optical design of a two-dimensional imaging soft X-ray spectrometer is described. A monochromator will produce a dispersed spectrum in a narrow vertical illuminated stripe (∼2 µm wide by ∼2 mm tall) on a sample. The spectrometer will use inelastically scattered X-rays to image the extended field on the sample in the incident photon energy direction (vertical), resolving the incident photon energy. At the same time it will image and disperse the scattered photons in the orthogonal (horizontal) direction, resolving the scattered photon energy. The principal challenge is to design a system that images from the flat-field illumination of the sample to the flat field of the detector and to achieve sufficiently high spectral resolution. This spectrometer provides a completely parallel resonant inelastic X-ray scattering measurement at high spectral resolution (∼30,000) over the energy bandwidth (∼5 eV) of a soft X-ray absorption resonance.