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Sample records for simultaneous 31p-nmr spectroscopy

  1. Simultaneous determination of phenolic compounds and triterpenic acids in oregano growing wild in Greece by 31P NMR spectroscopy.

    PubMed

    Agiomyrgianaki, Alexia; Dais, Photis

    2012-11-01

    (31)P nuclear magnetic resonance (NMR) spectroscopy was used to detect and quantify simultaneously a large number of phenolic compounds and the two triterpenic acids, ursolic acid and oleanolic acid, extracted from two oregano species Origanum onites and Origanum vulgare ssp. Hirtum using two different organic solvents ethanol and ethyl acetate. This analytical method is based on the derivatization of the hydroxyl and carboxyl groups of these compounds with the phosphorous reagent 2-chloro-4,4,5,5-tetramethyl-1,3,2-dioxa phospholane and the identification of the phosphitylated compounds on the basis of the (31)P chemical shifts. Unambiguous assignment of the (31)P NMR chemical shifts of the dihydroxy- and polyhydroxy-phenols in oregano species as well as those of the triterpenic acids was achieved upon comparison with the chemical shifts of model compounds assigned by using two-dimensional NMR techniques. Furthermore, the integration of the appropriate signals of the hydroxyl derivatives in the corresponding (31)P NMR spectra and the use of the phosphitylated cyclohexanol as an internal standard allowed the quantification of these compounds. The validity of this technique for quantitative measurements was thoroughly examined.

  2. 31P NMR spectroscopy of in vivo tumors

    NASA Astrophysics Data System (ADS)

    Ng, T. C.; Evanochko, W. T.; Hiramoto, R. N.; Ghanta, V. K.; Lilly, M. B.; Lawson, A. J.; Corbett, T. H.; Durant, J. R.; Glickson, J. D.

    A probe, suitable for any wide-bore NMR spectrometer, was constructed for monitoring high-resolution spectra of in vivo subcutaneously implanted tumors in mice. Preliminary studies of a variety of murine tumors (MOPC 104E myeloma, Dunn osteosarcoma, colon-26, ovarian M5, and mammary adenocarcinoma as well as human colon, mammary, and lung tumors in athymic mice) indicate that the 31P NMR spectrum is a sensitive monitor of progressive metabolic changes that occur during untreated tumor growth and an early indicator of tumor response to chemotherapy, hyperthermia, and X radiation. Response to each of these therapeutic modalities is accompanied by distinctly different spectral changes.

  3. Detoxification of organophosphorus pesticides and nerve agents through RSDL: efficacy evaluation by (31)P NMR spectroscopy.

    PubMed

    Elsinghorst, Paul W; Worek, Franz; Koller, Marianne

    2015-03-04

    Intoxication by organophosphorus compounds, especially by pesticides, poses a considerable risk to the affected individual. Countermeasures involve both medical intervention by means of antidotes as well as external decontamination to reduce the risk of dermal absorption. One of the few decontamination options available is Reactive Skin Decontamination Lotion (RSDL), which was originally developed for military use. Here, we present a (31)P NMR spectroscopy based methodology to evaluate the detoxification efficacy of RSDL with respect to a series of organophosphorus pesticides and nerve agents. Kinetic analysis of the obtained NMR data provided degradation half-lives proving that RSDL is also reasonably effective against organophosphorus pesticides. Unexpected observations of different RSDL degradation patterns are presented in view of its reported oximate-catalyzed mechanism of action.

  4. Chemical Characterization and Water Content Determination of Bio-Oils Obtained from Various Biomass Species using 31P NMR Spectroscopy

    SciTech Connect

    David, K.; Ben, H.; Muzzy, J.; Feik, C.; Iisa, K.; Ragauskas, A.

    2012-03-01

    Pyrolysis is a promising approach to utilize biomass for biofuels. One of the key challenges for this conversion is how to analyze complicated components in the pyrolysis oils. Water contents of pyrolysis oils are normally analyzed by Karl Fischer titration. The use of 2-chloro-4,4,5,5,-tetramethyl-1,3,2-dioxaphospholane followed by {sup 31}P NMR analysis has been used to quantitatively analyze the structure of hydroxyl groups in lignin and whole biomass. Results: {sup 31}P NMR analysis of pyrolysis oils is a novel technique to simultaneously characterize components and analyze water contents in pyrolysis oils produced from various biomasses. The water contents of various pyrolysis oils range from 16 to 40 wt%. The pyrolysis oils obtained from Loblolly pine had higher guaiacyl content, while that from oak had a higher syringyl content. Conclusion: The comparison with Karl Fischer titration shows that {sup 31}P NMR could also reliably be used to measure the water content of pyrolysis oils. Simultaneously with analysis of water content, quantitative characterization of hydroxyl groups, including aliphatic, C-5 substituted/syringyl, guaiacyl, p-hydroxyl phenyl and carboxylic hydroxyl groups, could also be provided by {sup 31}P NMR analysis.

  5. Analysis of monoglycerides, diglycerides, sterols, and free fatty acids in coconut (Cocos nucifera L.) oil by 31P NMR spectroscopy.

    PubMed

    Dayrit, Fabian M; Buenafe, Olivia Erin M; Chainani, Edward T; de Vera, Ian Mitchelle S

    2008-07-23

    Phosphorus-31 nuclear magnetic resonance spectroscopy ( (31)P NMR) was used to differentiate virgin coconut oil (VCO) from refined, bleached, deodorized coconut oil (RCO). Monoglycerides (MGs), diglycerides (DGs), sterols, and free fatty acids (FFAs) in VCO and RCO were converted into dioxaphospholane derivatives and analyzed by (31)P NMR. On the average, 1-MG was found to be higher in VCO (0.027%) than RCO (0.019%). 2-MG was not detected in any of the samples down to a detection limit of 0.014%. On the average, total DGs were lower in VCO (1.55%) than RCO (4.10%). When plotted in terms of the ratio [1,2-DG/total DGs] versus total DGs, VCO and RCO samples grouped separately. Total sterols were higher in VCO (0.096%) compared with RCO (0.032%), and the FFA content was 8 times higher in VCO than RCO (0.127% vs 0.015%). FFA determination by (31)P NMR and titration gave comparable results. Principal components analysis shows that the 1,2-DG, 1,3-DG, and FFAs are the most important parameters for differentiating VCO from RCO.

  6. Fluorescence anisotropy, FT-IR spectroscopy and 31-P NMR studies on the interaction of paclitaxel with lipid bilayers.

    PubMed

    Dhanikula, Anand Babu; Panchagnula, Ramesh

    2008-06-01

    To understand the bilayer interaction with paclitaxel, fluorescence polarization, Fourier transform infrared spectroscopy (FT-IR) and 31-phosphorus nuclear magnetic resonance (31P-NMR) studies were performed on paclitaxel bearing liposomes. Fluorescence anisotropy of three probes namely, 1,6-diphenyl-1,3,5-hexatriene (DPH), 12-(9-anthroyloxy) stearic acid (12AS) and 8-anilino-1-naphthalene sulfonate (ANS) were monitored as a function of paclitaxel concentration in the unsaturated bilayers. The incorporation of paclitaxel decreased anisotropy of 12AS and ANS probes, while slightly increased anisotropy of DPH. Paclitaxel has a fluidizing effect in the upper region of the bilayer whereas the hydrophobic core is slightly rigidized. FT-IR spectroscopy showed an increase in the asymmetric and symmetric methylene stretching frequencies, splitting of methylene scissoring band and broadening of carbonyl stretching mode. These studies collectively ascertained that paclitaxel mainly occupies the cooperativity region and interact with the interfacial region of unsaturated bilayers and induces fluidity in the headgroup region of bilayer. At higher loadings (>3 mol%), paclitaxel might gradually tend to accumulate at the interface and eventually partition out of bilayer as a result of solute exclusion phenomenon, resulting in crystallization; seed non-bilayer phases, as revealed by 31P-NMR, thereby destabilizing liposomal formulations. In general, any membrane component which has a rigidization effect will decrease, while that with a fluidizing effect will increase, with a bearing on headgroup interactions, partitioning of paclitaxel into bilayers and stability of the liposomes.

  7. A simple ergometer for 31P NMR spectroscopy during dynamic forearm exercise in a whole body magnetic resonance imaging system.

    PubMed

    Nishijima, H; Nishida, M; Anzai, T; Yonezawa, K; Fukuda, H; Sato, I; Yasuda, H

    1992-03-01

    The purpose of this study was to construct a simple ergometer for the 31P NMR spectroscopic study of dynamic forearm exercise in a whole body magnetic resonance imaging system and to evaluate the total system and the physiological response to this type of exercise using a multistage protocol. The system consisted of a completely nonmagnetic assembly including a rope, pulley and weights. The work of lifting weights was quantitated. The exercise protocol of 1-min increments in work load enabled subjects to reach maximal effort. Phosphocreatine decreased linearly with an increase in work load and was accompanied by a fall in pH and an increase in lactate level in the antecubital vein of the exercising forearm; concomitantly, there was a slight increase in whole body oxygen uptake and heart rate. Spectroscopy gave reproducible results using this exercise protocol. These results demonstrate that this system provides a reliable means for performing 31P magnetic resonance spectroscopy studies during forearm exercise.

  8. Hetergeneous tumour response to photodynamic therapy assessed by in vivo localised 31P NMR spectroscopy.

    PubMed Central

    Ceckler, T. L.; Gibson, S. L.; Kennedy, S. D.; Hill, R.; Bryant, R. G.

    1991-01-01

    Photodynamic therapy (PDT) is efficacious in the treatment of small malignant lesions when all cells in the tumour receive sufficient drug, oxygen and light to induce a photodynamic effect capable of complete cytotoxicity. In large tumours, only partial effectiveness is observed presumably because of insufficient light penetration into the tissue. The heterogeneity of the metabolic response in mammary tumours following PDT has been followed in vivo using localised phosphorus NMR spectroscopy. Alterations in nucleoside triphosphates (NTP), inorganic phosphate (Pi) and pH within localised regions of the tumour were monitored over 24-48 h following PDT irradiation of the tumour. Reduction of NTP and increases in Pi were observed at 4-6 h after PDT irradiation in all regions of treated tumours. The uppermost regions of the tumours (those nearest the skin surface and exposed to the greatest light fluence) displayed the greatest and most prolonged reduction of NTP and concomitant increase in Pi resulting in necrosis. The metabolite concentrations in tumour regions located towards the base of the tumour returned a near pre-treatment levels by 24-48 h after irradiation. The ability to follow heterogeneous metabolic responses in situ provides one means to assess the degree of metabolic inhibition which subsequently leads to tumour necrosis. Images Figure 4 PMID:1829953

  9. Differences in nucleotide compartmentation and energy state in isolated and in situ rat heart: assessment by 31P-NMR spectroscopy.

    PubMed

    Williams, J P; Headrick, J P

    1996-08-07

    Free cytosolic concentrations of ATP, PCr, ADP and 5'-AMP, and the cytosolic [ATP]/[ADP].[Pi] ratio, were determined in isolated and in situ rat hearts using 31P-NMR spectroscopy. Total tissue metabolite concentrations were determined by HPLC analysis of freeze-clamped, perchloric acid-extracted tissue. In in situ myocardium the PCr/ATP ratio was 2.7 +/- 0.2 determined from 31P-NMR data (using either PCr/beta-NTP or PCr/gamma-NTP), and 1.9 +/- 0.1 (P < 0.01) determined from total tissue concentrations. 31P-NMR-determined and total tissue [PCr] were in excellent agreement (49.6 +/- 8.4 and 49.5 +/- 1.0 mumol.g-1 dry wt, respectively), whereas 31P-NMR-determined [ATP] (18.6 +/- 3.2 mumol.g-1 dry wt) was only 71% of the total tissue concentration (26.1 +/- 1.7 mumol.g-1 dry wt, P < 0.01). Isolation and Langendorff perfusion of rat hearts with glucose as substrate reduced total tissue [ATP] and [PCr] and the 31P-NMR-determined PCr/ATP ratio fell to 1.5 +/- 0.1. This value agreed well with the total tissue ratio of 1.4 +/- 0.1, and there was excellent agreement between 31P-NMR-determined and total tissue [PCr] and [ATP] values in the perfused heart. Addition of pyruvate to perfusate increased the 31P-NMR-determined PCr/ATP ratio to 1.7 +/- 0.1 due to elevated [PCr], and there remained excellent agreement between NMR-determined and total tissue [PCr] and [ATP] values. Free cytosolic [ADP] (from the creatine kinase equilibrium) was 5% of total tissue ADP, and free cytosolic [5'-AMP] (from the adenylate kinase equilibrium) ranged from 0.2-0.3% of total tissue 5'-AMP. Bioenergetic state, indexed by [ATP]/[ADP].[Pi], was much lower in isolated perfused hearts (30 mM-1) vs. in situ myocardium (approximately 150 mM-1). In summary, we observe a substantial disproportionality between total tissue PCr/ATP and 31P-NMR-determined PCr/ATP in highly energised in situ myocardium but not in isolated perfused hearts. This appears due to an NMR invisible ATP compartment approximating 29

  10. Analysis of the urinary excretion of ifosfamide and its N-dechloroethylated metabolites in children using 31P-NMR spectroscopy.

    PubMed

    Misiura, Konrad; Zubowska, Małgorzata; Zielińska, Elzbieta

    2003-01-01

    Amounts of ifosfamide (CAS 3778-73-2) and its N-dechloroethylated metabolites excreted in the urine were measured using 31P-NMR spectroscopy in 26 cancer children treated with this drug. Strong inter-patient variation in levels of these compounds were found. These differences were independent from patients age, body surface area, and sex, the dose of the drug, suggesting genetic base of observed variations in ifosfamide metabolism.

  11. Quantitative (31)P NMR spectroscopy and (1)H MRI measurements of bone mineral and matrix density differentiate metabolic bone diseases in rat models.

    PubMed

    Cao, Haihui; Nazarian, Ara; Ackerman, Jerome L; Snyder, Brian D; Rosenberg, Andrew E; Nazarian, Rosalynn M; Hrovat, Mirko I; Dai, Guangping; Mintzopoulos, Dionyssios; Wu, Yaotang

    2010-06-01

    In this study, bone mineral density (BMD) of normal (CON), ovariectomized (OVX), and partially nephrectomized (NFR) rats was measured by (31)P NMR spectroscopy; bone matrix density was measured by (1)H water- and fat-suppressed projection imaging (WASPI); and the extent of bone mineralization (EBM) was obtained by the ratio of BMD/bone matrix density. The capability of these MR methods to distinguish the bone composition of the CON, OVX, and NFR groups was evaluated against chemical analysis (gravimetry). For cortical bone specimens, BMD of the CON and OVX groups was not significantly different; BMD of the NFR group was 22.1% (by (31)P NMR) and 17.5% (by gravimetry) lower than CON. For trabecular bone specimens, BMD of the OVX group was 40.5% (by (31)P NMR) and 24.6% (by gravimetry) lower than CON; BMD of the NFR group was 26.8% (by (31)P NMR) and 21.5% (by gravimetry) lower than CON. No significant change of cortical bone matrix density between CON and OVX was observed by WASPI or gravimetry; NFR cortical bone matrix density was 10.3% (by WASPI) and 13.9% (by gravimetry) lower than CON. OVX trabecular bone matrix density was 38.0% (by WASPI) and 30.8% (by gravimetry) lower than CON, while no significant change in NFR trabecular bone matrix density was observed by either method. The EBMs of OVX cortical and trabecular specimens were slightly higher than CON but not significantly different from CON. Importantly, EBMs of NFR cortical and trabecular specimens were 12.4% and 26.3% lower than CON by (31)P NMR/WASPI, respectively, and 4.0% and 11.9% lower by gravimetry. Histopathology showed evidence of osteoporosis in the OVX group and severe secondary hyperparathyroidism (renal osteodystrophy) in the NFR group. These results demonstrate that the combined (31)P NMR/WASPI method is capable of discerning the difference in EBM between animals with osteoporosis and those with impaired bone mineralization.

  12. Synthesis, crystal structure, vibrational and 31P-NMR spectroscopy of the thiophosphate NaMg[PO3S]·9H2O

    NASA Astrophysics Data System (ADS)

    Höppe, Henning A.; Scharinger, Stefan W.; Heck, Joachim G.; Gross, Peter; Netzsch, Philip; Kazmierczak, Karolina

    2016-12-01

    NaMg[PO3S]·9H2O was obtained as single-phase crystalline powder starting from NaOH, PSCl3 and MgCl2·6H2O. At room temperature NaMg[PO3S]·9H2O crystallises in space group Cmc21 (no. 36) (a=638.58(4) pm, b=1632.31(10) pm, c=1217.16(7) pm, Z = 4; Rint = 0.032, Rσ = 0.034, R1 = 0.036, wR2 = 0.071). The data collection at 100 K reveals an ordering of the PO3S tetrahedra by undergoing a symmetry reduction to P21 (no. 4) and an according formation of twins (C1121, unconv. setting of P21, a=631.41(3) pm, b=1630.00(7) pm, c=1219.24(5) pm, γ=90.00(2)°, Z = 4; Rint = 0.115, Rσ = 0.064, R1 = 0.045, wR2 = 0.070). NaMg[PO3S]·9H2O comprises isolated PO3S tetrahedra, distorted MgO6 octahedra and trigonal NaO6 prisms. 31P NMR spectroscopy showed a chemical shift of 33.7 ppm. The vibrational spectra of NaMg[PO3S]·9H2O were recorded and the relevant bands were assigned.

  13. An examination of the metabolic processes underpinning critical swimming in Atlantic cod (Gadus morhua L.) using in vivo 31P-NMR spectroscopy.

    PubMed

    Lurman, Glenn J; Bock, Christian H; Pörtner, Hans-O

    2007-11-01

    Traditionally, critical swimming speed has been defined as the speed when a fish can no longer propel itself forward, and is exhausted. To gain a better understanding of the metabolic processes at work during a U(crit) swim test, and that lead to fatigue, we developed a method using in vivo (31)P-NMR spectroscopy in combination with a Brett-type swim tunnel. Our data showed that a metabolic transition point is reached when the fish change from using steady state aerobic metabolism to non-steady state anaerobic metabolism, as indicated by a significant increase in inorganic phosphate levels from 0.3+/-0.3 to 9.5+/-3.4 mol g(-1), and a drop in intracellular pH from 7.48+/-0.03 to 6.81+/-0.05 in muscle. This coincides with the point when the fish change gait from subcarangiform swimming to kick-and-glide bursts. As the number of kicks increased, so too did the Pi concentration, and the pH(i) dropped. Both changes were maximal at U(crit). A significant drop in Gibbs free energy change of ATP hydrolysis from -55.6+/-1.4 to -49.8+/-0.7 kJ mol(-1) is argued to have been involved in fatigue. This confirms earlier findings that the traditional definition of U(crit), unlike other critical points that are typically marked by a transition from aerobic to anaerobic metabolism, is the point of complete exhaustion of both aerobic and anaerobic resources.

  14. Characteristics and degradation of carbon and phosphorus from aquatic macrophytes in lakes: Insights from solid-state (13)C NMR and solution (31)P NMR spectroscopy.

    PubMed

    Liu, Shasha; Zhu, Yuanrong; Meng, Wei; He, Zhongqi; Feng, Weiying; Zhang, Chen; Giesy, John P

    2016-02-01

    Water extractable organic matter (WEOM) derived from macrophytes plays an important role in biogeochemical cycling of nutrients, including carbon (C), nitrogen (N) and phosphorus (P) in lakes. However, reports of their composition and degradation in natural waters are scarce. Therefore, compositions and degradation of WEOM derived from six aquatic macrophytes species of Tai Lake, China, were investigated by use of solid-state (13)C NMR and solution (31)P NMR spectroscopy. Carbohydrates were the predominant constituents of WEOM fractions, followed by carboxylic acid. Orthophosphate (ortho-P) was the dominant form of P (78.7% of total dissolved P) in the water extracts, followed by monoester P (mono-P) (20.6%) and little diester P (0.65%). The proportion of mono-P in total P species increased with the percentage of O-alkyl and O-C-O increasing in the WEOM, which is likely due to degradation and dissolution of biological membranes and RNA from aquatic plants. Whereas the proportion of mono-P decreased with alkyl-C, NCH/OCH3 and COO/N-C=O increasing, which may be owing to the insoluble compounds including C functional groups of alkyl-C, NCH/OCH3 and COO/N-C=O, such as aliphatic biopolymers, lignin and peptides. Based on the results of this study and information in the literature about water column and sediment, we propose that WEOM, dominated by polysaccharides, are the most labile and bioavailable component in debris of macrophytes. Additionally, these WEOMs would also be a potential source for bioavailable organic P (e.g., RNA, DNA and phytate) for lakes.

  15. Coal liquefaction process streams characterization and evaluation: Estimation of total phenol concentrations in coal liquefaction resids by [sup 31]P NMR spectroscopy

    SciTech Connect

    Mohan, J.T.; Verkade, J.G. )

    1992-11-01

    In this study, Iowa State University researchers used [sub 31]P-tagged reagents to derivatize the labile hydrogen functional groups in the THF-soluble portion of 850[degrees]F[sup +] distillation resid materials and the THF-soluble portion of process oils derived from direct coal liquefaction.[sup 31]P-NMR was used to analyze the derivatized samples. NMR peak assignments can be made by comparison to model compounds similarly derivatized. Species can be quantified by integration of the NMR signals. Different [sup 31]P-NMR tagged reagents can be used to produce different degrees of peak resolution in the NMR spectrum. This, in turn, partially dictates the degree of speciation and/or quantification of species, or classes of compounds, that can be accomplished. Iowa State chose a [sup 31]P-tagged reagent (ClPOCMe[sub 2]CMe[sub 2]O) which was shown previously to be particularly useful in the derivatization of phenols. The derivatized samples all exhibited a small group of peaks attributed to amines and a broad group of peaks in the phenol region. The presence of paramagnetic species in the samples caused the NMR signals to broaden. Electron paramagnetic resonance (EPR) spectra confirmed the presence of paramagnetic organic free radicals in selected samples. Various methods were employed to process the NMR data. The complexity and broadness of the phenol peak, however, made speciation of the phenols impractical.

  16. Coal liquefaction process streams characterization and evaluation: Estimation of total phenol concentrations in coal liquefaction resids by {sup 31}P NMR spectroscopy

    SciTech Connect

    Mohan, J.T.; Verkade, J.G.

    1992-11-01

    In this study, Iowa State University researchers used {sub 31}P-tagged reagents to derivatize the labile hydrogen functional groups in the THF-soluble portion of 850{degrees}F{sup +} distillation resid materials and the THF-soluble portion of process oils derived from direct coal liquefaction.{sup 31}P-NMR was used to analyze the derivatized samples. NMR peak assignments can be made by comparison to model compounds similarly derivatized. Species can be quantified by integration of the NMR signals. Different {sup 31}P-NMR tagged reagents can be used to produce different degrees of peak resolution in the NMR spectrum. This, in turn, partially dictates the degree of speciation and/or quantification of species, or classes of compounds, that can be accomplished. Iowa State chose a {sup 31}P-tagged reagent (ClPOCMe{sub 2}CMe{sub 2}O) which was shown previously to be particularly useful in the derivatization of phenols. The derivatized samples all exhibited a small group of peaks attributed to amines and a broad group of peaks in the phenol region. The presence of paramagnetic species in the samples caused the NMR signals to broaden. Electron paramagnetic resonance (EPR) spectra confirmed the presence of paramagnetic organic free radicals in selected samples. Various methods were employed to process the NMR data. The complexity and broadness of the phenol peak, however, made speciation of the phenols impractical.

  17. Probing the PI3K/Akt/mTor pathway using 31P-NMR spectroscopy: routes to glycogen synthase kinase 3

    PubMed Central

    Phyu, Su M.; Tseng, Chih-Chung; Fleming, Ian N.; Smith, Tim A. D.

    2016-01-01

    Akt is an intracellular signalling pathway that serves as an essential link between cell surface receptors and cellular processes including proliferation, development and survival. The pathway has many downstream targets including glycogen synthase kinase3 which is a major regulatory kinase for cell cycle transit as well as controlling glycogen synthase activity. The Akt pathway is frequently up-regulated in cancer due to overexpression of receptors such as the epidermal growth factor receptor, or mutation of signalling pathway kinases resulting in inappropriate survival and proliferation. Consequently anticancer drugs have been developed that target this pathway. MDA-MB-468 breast and HCT8 colorectal cancer cells were treated with inhibitors including LY294002, MK2206, rapamycin, AZD8055 targeting key kinases in/associated with Akt pathway and the consistency of changes in 31P-NMR-detecatable metabolite content of tumour cells was examined. Treatment with the Akt inhibitor MK2206 reduced phosphocholine levels in MDA-MB-468 cells. Treatment with either the phosphoinositide-3-kinase inhibitor, LY294002 and pan-mTOR inhibitor, AZD8055 but not pan-Akt inhibitor MK2206 increased uridine-5′-diphosphate-hexose cell content which was suppressed by co-treatment with glycogen synthase kinase 3 inhibitor SB216763. This suggests that there is an Akt-independent link between phosphoinositol-3-kinase and glycogen synthase kinase3 and demonstrates the potential of 31P-NMR to probe intracellular signalling pathways. PMID:27811956

  18. Variations of different dissolved and particulate phosphorus classes during an algae bloom in a eutrophic lake by (31)P NMR spectroscopy.

    PubMed

    Bai, Xiuling; Sun, Jinhua; Zhou, Yunkai; Gu, Lei; Zhao, Hongyan; Wang, Jiehua

    2017-02-01

    Characterization of phosphorus (P) pools is vital to understanding the contribution of P to water eutrophication. In this study, dissolved and particulate P classes during an algae bloom in Lake Taihu, as well as their relationships with the main environmental factors, were analyzed based on solution (31)P NMR. The results showed that dissolved P was dominated by orthophosphate (Ortho-P) in heavily polluted regions and by orthophosphate monoester (Mono-P) and orthophosphate diester (Diester-P) in lightly polluted regions, indicating that the main dissolved P classes varied with the degree of lake pollution. The difference in the temporal variation patterns of dissolved P classes revealed that dissolved Ortho-P is the preferred class, and its concentration may be affected by major primary producers. It also revealed that dissolved Mono-P is prone to accumulation under the effects of algal blooms, especially in heavily polluted regions. The main particulate P classes were similar to those of dissolved P, but their variation trends were the same in different lake regions. There were significant positive correlations between the major particulate P classes and Chl a during the majority of the sampling period, indicating that living algal cells have a major contribution to particulate P. Obvious temporal variations of P classes may affect the bioavailability and dynamics of P in the water of Lake Taihu, but the particle reactivities of the main inorganic and organic P classes were similar. Therefore, they have little effect on P partitioning between the dissolved and particulate phases.

  19. Quantitative 31P NMR for Simultaneous Trace Analysis of Organophosphorus Pesticides in Aqueous Media Using the Stir Bar Sorptive Extraction Method

    NASA Astrophysics Data System (ADS)

    Ansari, S.; Talebpour, Z.; Molaabasi, F.; Bijanzadeh, H. R.; Khazaeli, S.

    2016-09-01

    The analysis of pesticides in water samples is of primary concern for quality control laboratories due to the toxicity of these compounds and their associated public health risk. A novel analytical method based on stir bar sorptive extraction (SBSE), followed by 31P quantitative nuclear magnetic resonance (31P QNMR), has been developed for simultaneously monitoring and determining four organophosphorus pesticides (OPPs) in aqueous media. The effects of factors on the extraction efficiency of OPPs were investigated using a Draper-Lin small composite design. An optimal sample volume of 4.2 mL, extraction time of 96 min, extraction temperature of 42°C, and desorption time of 11 min were obtained. The results showed reasonable linearity ranges for all pesticides with correlation coefficients greater than 0.9920. The limit of quantification (LOQ) ranged from 0.1 to 2.60 mg/L, and the recoveries of spiked river water samples were from 82 to 94% with relative standard deviation (RSD) values less than 4%. The results show that this method is simple, selective, rapid, and can be applied to other sample matrices.

  20. Catalytic mechanism of α-phosphate attack in dUTPase is revealed by X-ray crystallographic snapshots of distinct intermediates, 31P-NMR spectroscopy and reaction path modelling.

    PubMed

    Barabás, Orsolya; Németh, Veronika; Bodor, Andrea; Perczel, András; Rosta, Edina; Kele, Zoltán; Zagyva, Imre; Szabadka, Zoltán; Grolmusz, Vince I; Wilmanns, Matthias; Vértessy, Beáta G

    2013-12-01

    Enzymatic synthesis and hydrolysis of nucleoside phosphate compounds play a key role in various biological pathways, like signal transduction, DNA synthesis and metabolism. Although these processes have been studied extensively, numerous key issues regarding the chemical pathway and atomic movements remain open for many enzymatic reactions. Here, using the Mason-Pfizer monkey retrovirus dUTPase, we study the dUTPase-catalyzed hydrolysis of dUTP, an incorrect DNA building block, to elaborate the mechanistic details at high resolution. Combining mass spectrometry analysis of the dUTPase-catalyzed reaction carried out in and quantum mechanics/molecular mechanics (QM/MM) simulation, we show that the nucleophilic attack occurs at the α-phosphate site. Phosphorus-31 NMR spectroscopy ((31)P-NMR) analysis confirms the site of attack and shows the capability of dUTPase to cleave the dUTP analogue α,β-imido-dUTP, containing the imido linkage usually regarded to be non-hydrolyzable. We present numerous X-ray crystal structures of distinct dUTPase and nucleoside phosphate complexes, which report on the progress of the chemical reaction along the reaction coordinate. The presently used combination of diverse structural methods reveals details of the nucleophilic attack and identifies a novel enzyme-product complex structure.

  1. Hepatic lipid profiling of deer mice fed ethanol using {sup 1}H and {sup 31}P NMR spectroscopy: A dose-dependent subchronic study

    SciTech Connect

    Fernando, Harshica; Bhopale, Kamlesh K.; Boor, Paul J.; Ansari, G.A. Shakeel; Kaphalia, Bhupendra S.

    2012-11-01

    Chronic alcohol abuse is a 2nd major cause of liver disease resulting in significant morbidity and mortality. Alcoholic liver disease (ALD) is characterized by a wide spectrum of pathologies starting from fat accumulation (steatosis) in early reversible stage to inflammation with or without fibrosis and cirrhosis in later irreversible stages. Previously, we reported significant steatosis in the livers of hepatic alcohol dehydrogenase (ADH)-deficient (ADH{sup −}) vs. hepatic ADH-normal (ADH{sup +}) deer mice fed 4% ethanol daily for 2 months [Bhopale et al., 2006, Alcohol 39, 179–188]. However, ADH{sup −} deer mice fed 4% ethanol also showed a significant mortality. Therefore, a dose-dependent study was conducted to understand the mechanism and identify lipid(s) involved in the development of ethanol-induced fatty liver. ADH{sup −} and ADH{sup +} deer mice fed 1, 2 or 3.5% ethanol daily for 2 months and fatty infiltration in the livers were evaluated by histology and by measuring dry weights of extracted lipids. Lipid metabolomic changes in extracted lipids were determined by proton ({sup 1}H) and {sup 31}phosphorus ({sup 31}P) nuclear magnetic resonance (NMR) spectroscopy. The NMR data was analyzed by hierarchical clustering (HC) and principle component analysis (PCA) for pattern recognition. Extensive vacuolization by histology and significantly increased dry weights of total lipids found only in the livers of ADH{sup −} deer mice fed 3.5% ethanol vs. pair-fed controls suggest a dose-dependent formation of fatty liver in ADH{sup −} deer mouse model. Analysis of NMR data of ADH{sup −} deer mice fed 3.5% ethanol vs. pair-fed controls shows increases for total cholesterol, esterified cholesterol, fatty acid methyl esters (FAMEs), triacylglycerides and unsaturation, and decreases for free cholesterol, phospholipids and allylic and diallylic protons. Certain classes of neutral lipids (cholesterol esters, fatty acyl chain (-COCH{sub 2}-) and FAMEs) were

  2. Evaluation of Phosphorus Characterization in Broiler Ileal Digesta, Manure, and Litter Samples: 31P-NMR vs. HPLC

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Using 31-Phosphorus Nuclear Magnetic Resosonance Spectroscopy (31P-NMR) to characterize phosphorus (P) in manures and litter has become prevalent in the area of nutrient management. To date, there has been no published work evaluating P quantification in manure/litter samples with 31P-NMR compared t...

  3. Role of magnesium and calcium in alcohol-induced hypertension and strokes as probed by in vivo television microscopy, digital image microscopy, optical spectroscopy, 31P-NMR, spectroscopy and a unique magnesium ion-selective electrode.

    PubMed

    Altura, B M; Altura, B T

    1994-10-01

    It is not known why alcohol ingestion poses a risk for development of hypertension, stroke and sudden death. Of all drugs, which result in body depletion of magnesium (Mg), alcohol is now known to be the most notorious cause of Mg-wasting. Recent data obtained through the use of biophysical (and noninvasive) technology suggest that alcohol may induce hypertension, stroke, and sudden death via its effects on intracellular free Mg2+ ([Mg2+]i), which in turn alter cellular and subcellular bioenergetics and promote calcium ion (Ca2+) overload. Evidence is reviewed that demonstrates that the dietary intake of Mg modulates the hypertensive actions of alcohol. Experiments with intact rats indicates that chronic ethanol ingestion results in both structural and hemodynamic alterations in the microcirculation, which, in themselves, could account for increased vascular resistance. Chronic ethanol increases the reactivity of intact microvessels to vasoconstrictors and results in decreased reactivity to vasodilators. Chronic ethanol ingestion clearly results in vascular smooth muscle cells that exhibit a progressive increase in exchangeable and cellular Ca2+ concomitant with a progressive reduction in Mg content. Use of 31P-NMR spectroscopy coupled with optical-backscatter reflectance spectroscopy revealed that acute ethanol administration to rats results in dose-dependent deficits in phosphocreatine (PCr), the [PCr]/[ATP] ratio, intracellular pH (pHi), oxyhemoglobin, and the mitochondrial level of oxidized cytochrome oxidase aa3 concomitant with a rise in brain-blood volume and inorganic phosphate. Temporal studies performed in vivo, on the intact brain, indicate that [Mg2+]i is depleted before any of the bioenergetic changes. Pretreatment of animals with Mg2+ prevents ethanol from inducing stroke and prevents all of the adverse bioenergetic changes from taking place. Use of quantitative digital imaging microscopy, and mag-fura-2, on single-cultured canine cerebral vascular

  4. Using solid (13)C NMR coupled with solution (31)P NMR spectroscopy to investigate molecular species and lability of organic carbon and phosphorus from aquatic plants in Tai Lake, China.

    PubMed

    Liu, Shasha; Zhu, Yuanrong; Wu, Fengchang; Meng, Wei; Wang, Hao; He, Zhongqi; Guo, Wenjing; Song, Fanhao; Giesy, John P

    2017-01-01

    Forms and labilities of plant-derived organic matters (OMs) including carbon (C) and phosphorus (P) were fundamental for understanding their release, degradation and environmental behaviour in lake ecosystems. Thus, solid (13)C and solution (31)P nuclear magnetic resonance (NMR) spectroscopy were used to characterize biomass of six aquatic plants in Tai Lake, China. The results showed that carbohydrates (61.2% of the total C) were predominant C functional group in the solid (13)C NMR spectra of plant biomass, which may indicate high lability and bioavailability of aquatic plants-derived organic matter in lakes. There was 72.6-103.7% of the total P in aquatic plant biomass extracted by NaOH-EDTA extracts. Solution (31)P NMR analysis of these NaOH-EDTA extracts further identified several molecular species of P including orthophosphate (50.1%), orthophosphate monoesters (46.8%), DNA (1.6%) and pyrophosphate (1.4%). Orthophosphate monoesters included β-glycerophosphate (17.7%), hydrolysis products of RNA (11.7%), α-glycerophosphate (9.2%) and other unknown monoesters (2.1%). Additionally, phytate, the major form of organic P in many lake sediments, was detected in floating plant water poppy. These inorganic P (e.g. orthophosphate and pyrophosphate) and organic P (e.g. diester and its degradation products) identified in plant biomass were all labile and bioavailable P, which would play an important role in recycling of P in lakes. These results increased knowledge of chemical composition and bioavailability of OMs derived from aquatic plants in lakes.

  5. Comparison of phosphorus forms in three extracts of dairy feces by solution 31P NMR analysis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Using solution 31P NMR spectroscopy, we compared three extractants, deionized water, sodium acetate buffer (pH 5.0) with fresh sodium dithionite (NaAc-SD), and 0.25 M NaOH-0.05 M EDTA (NaOH-EDTA), for the profile of P compounds in two dairy fecal samples. Phosphorus extracted was 35% for water, and...

  6. Evaluation of phosphorus characterization in broiler ileal digesta, manure, and litter samples: (31)P-NMR vs. HPLC.

    PubMed

    Leytem, A B; Kwanyuen, P; Plumstead, P W; Maguire, R O; Brake, J

    2008-01-01

    Using 31-phosphorus nuclear magnetic resonance spectroscopy ((31)P-NMR) to characterize phosphorus (P) in animal manures and litter has become a popular technique in the area of nutrient management. To date, there has been no published work evaluating P quantification in manure/litter samples with (31)P-NMR compared to other accepted methods such as high performance liquid chromatography (HPLC). To evaluate the use of (31)P-NMR to quantify myo-inositol hexakisphosphate (phytate) in ileal digesta, manure, and litter from broilers, we compared results obtained from both (31)P-NMR and a more traditional HPLC method. The quantification of phytate in all samples was very consistent between the two methods, with linear regressions having slopes ranging from 0.94 to 1.07 and r(2) values of 0.84 to 0.98. We compared the concentration of total monoester P determined with (31)P-NMR with the total inositol P content determined with HPLC and found a strong linear relationship between the two measurements having slopes ranging from 0.91 to 1.08 and r(2) values of 0.73 to 0.95. This suggests that (31)P-NMR is a very reliable method for quantifying P compounds in manure/litter samples.

  7. Liquid-liquid extraction of metal ions by neutral phosphoramides. Part I. Extraction of uranyl ions from nitrate and sulphate media. Examination of extracted species by UV/VIS and {sup 31}P NMR spectroscopy

    SciTech Connect

    Rodehueser, L.; Rubini, P.R.; Bokolo, K.; Laakel, N.; Delpuech, J.J.

    1992-09-01

    The extraction of uranyl nitrate and uranyl sulphate from aqueous media by the neutral chelating diphosphoramides CH{sub 3}-N[P(O)(NMe{sub 2}){sub 2}]{sub 2} (NIPA) and its less hydrophilic homologs R-N[P(O)(NMe{sub 2}){sub 2}]{sub 2} (R = -C{sub 12}H{sub 25} (ODIPA) or -C{sub 16}H{sub 33} (OHDIPA)), diluted in CH{sub 3}NO{sub 2} or toluene, has been studied. In the presence of HNO{sub 3}, NaNO{sub 3}, NaCl, and Na{sub 2}SO{sub 4} as salting-out agents, extraction is generally excellent. Some of the extracted complex species have been identified by comparing their {sup 31}P NMR and UV/vis spectra with those of pure complexes of known structure. The results are compared with extractions using tri-n-butyl phosphate (TBP) as the complexing agent. 20 refs., 9 figs., 4 tabs.

  8. /sup 31/P-NMR differentiation between intracellular phosphate pools in Cosmarium (chlorophyta)

    SciTech Connect

    Elgavish, A.; Elgavish, G.A.

    1980-09-01

    /sup 31/P nuclear magnetic resonance (NMR) spectroscopy of intact Cosmarium sp. cells is presented as a suitable tool for the differentiation of intracellular accumulation pools of polyphosphates. The cold trichloroacetic acid (TCA) insoluble fraction is shown to contain most of the total cellular phosphate in the phosphate rich Cosmarium cells. Moreover, evidence from a /sup 31/P-NMR study and electron microscopic observations of cold TCA treated Cosmarium cells indicate that this fraction consists mostly of polyphosphates which seem to retain the native morphological structure observed in the untreated cells. The determination of orthophosphate in the hot water extract of Cosmarium cells did not measure the polyphosphate pools. Determination of total phosphorus content in the hot water extract rendered a value three times higher than the frequently used orthophosphate determination procedure. However, as revealed by the /sup 31/P-NMR spectra and the chemical analyses of the extract and of the treated cells, even total phosphorus in the extract measured only 30% of the total cellular phosphorus. /sup 31/P-NMR enabled the unequivocal chemical identification of the major phosphate compounds in the hot water extract (Surplus P) as orthophosphate and polyphosphates of about 10 phosphate units chainlength. More than 70% of the accumulation pool of polyphosphates was still in the cells after extraction. However, the electron microscopy study revealed that the native granular structure of polyphosphates had been destroyed by the hot water extraction procedure.

  9. Using solid 13C NMR coupled with solution 31P NMR spectroscopy to investigate molecular species and lability of organic carbon and phosphorus from aquatic plants in Tai Lake, China

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Aquatic plants are involved in the storage and release capacity for organic matter and nutrients. In this study, solid 13C and solution 31P nuclear magnetic resonance (NMR) spectroscopy were used to characterize the biomass samples of six aquatic plants. Solid 13C NMR spectroscopy revealed the domin...

  10. The host plant Pinus pinaster exerts specific effects on phosphate efflux and polyphosphate metabolism of the ectomycorrhizal fungus Hebeloma cylindrosporum: a radiotracer, cytological staining and (31) P NMR spectroscopy study.

    PubMed

    Torres-Aquino, Margarita; Becquer, Adeline; Le Guernevé, Christine; Louche, Julien; Amenc, Laurie K; Staunton, Siobhan; Quiquampoix, Hervé; Plassard, Claude

    2017-02-01

    Ectomycorrhizal (ECM) association can improve plant phosphorus (P) nutrition. Polyphosphates (polyP) synthesized in distant fungal cells after P uptake may contribute to P supply from the fungus to the host plant if they are hydrolyzed to phosphate in ECM roots then transferred to the host plant when required. In this study, we addressed this hypothesis for the ECM fungus Hebeloma cylindrosporum grown in vitro and incubated without plant or with host (Pinus pinaster) and non-host (Zea mays) plants, using an experimental system simulating the symbiotic interface. We used (32) P labelling to quantify P accumulation and P efflux and in vivo and in vitro nuclear magnetic resonance (NMR) spectroscopy and cytological staining to follow the fate of fungal polyP. Phosphate supply triggered a massive P accumulation as newly synthesized long-chain polyP in H. cylindrosporum if previously grown under P-deficient conditions. P efflux from H. cylindrosporum towards the roots was stimulated by both host and non-host plants. However, the host plant enhanced (32) P release compared with the non-host plant and specifically increased the proportion of short-chain polyP in the interacting mycelia. These results support the existence of specific host plant effects on fungal P metabolism able to provide P in the apoplast of ectomycorrhizal roots.

  11. Inhibition mechanisms of Zn precipitation on aluminum oxide by glyphosate: a 31P NMR and Zn EXAFS study.

    PubMed

    Li, Wei; Wang, Yu-Jun; Zhu, Mengqiang; Fan, Ting-Ting; Zhou, Dong-Mei; Phillips, Brian L; Sparks, Donald L

    2013-05-07

    In this research, the effects of glyphosate (GPS) on Zn sorption/precipitation on γ-alumina were investigated using a batch technique, Zn K-edge EXAFS, and (31)P NMR spectroscopy. The EXAFS analysis revealed that, in the absence of glyphosate, Zn adsorbed on the aluminum oxide surface mainly as bidentate mononuclear surface complexes at pH 5.5, whereas Zn-Al layered double hydroxide (LDH) precipitates formed at pH 8.0. In the presence of glyphosate, the EXAFS spectra of Zn sorption samples at pH 5.5 and 8.0 were very similar, both of which demonstrated that Zn did not directly bind to the mineral surface but bonded with the carboxyl group of glyphosate. Formation of γ-alumina-GPS-Zn ternary surface complexes was further suggested by (31)P solid state NMR data which indicated the glyphosate binds to γ-alumina via a phosphonate group, bridging the mineral surface and Zn. Additionally, we showed the sequence of additional glyphosate and Zn can influence the sorption mechanism. At pH 8, Zn-Al LDH precipitates formed if Zn was added first, and no precipitates formed if glyphosate was added first or simultaneously with Zn. In contrast, at pH 5.5, only γ-alumina-GPS-Zn ternary surface complexes formed regardless of whether glyphosate or Zn was added first or both were added simultaneously.

  12. Forms and Lability of Phosphorus in Algae and Aquatic Macrophytes Characterized by Solution 31P NMR Coupled with Enzymatic Hydrolysis

    NASA Astrophysics Data System (ADS)

    Feng, Weiying; Zhu, Yuanrong; Wu, Fengchang; He, Zhongqi; Zhang, Chen; Giesy, John P.

    2016-11-01

    Solution Phosphorus-31 nuclear magnetic resonance (31P NMR) spectroscopy coupled with enzymatic hydrolysis (EH) with commercially available phosphatases was used to characterize phosphorus (P) compounds in extracts of the dominant aquatic macrophytes and algae in a eutrophic lake. Total extractable organic P (Po) concentrations ranged from 504 to 1643 mg kg‑1 and 2318 to 8395 mg kg‑1 for aquatic macrophytes and algae, respectively. Using 31P NMR spectroscopy, 11 Po species were detected in the mono- and diester region. Additionally, orthophosphate, pyrophosphate and phosphonates were also detected. Using EH, phytate-like P was identified as the prevalent class of enzyme-labile Po, followed by labile monoester- and diester-P. Comparison of the NMR and EH data indicated that the distribution pattern of major P forms in the samples determined by the two methods was similar (r = 0.712, p < 0.05). Additional 31P NMR spectroscopic analysis of extracts following EH showed significant decreases in the monoester and pyrophosphate regions, with a corresponding increase in the orthophosphate signal, as compared to unhydrolyzed extracts. Based on these quantity and hydrolysis data, we proposed that recycling of Po in vegetative biomass residues is an important mechanism for long-term self-regulation of available P for algal blooming in eutrophic lakes.

  13. Forms and Lability of Phosphorus in Algae and Aquatic Macrophytes Characterized by Solution 31P NMR Coupled with Enzymatic Hydrolysis

    PubMed Central

    Feng, Weiying; Zhu, Yuanrong; Wu, Fengchang; He, Zhongqi; Zhang, Chen; Giesy, John P.

    2016-01-01

    Solution Phosphorus-31 nuclear magnetic resonance (31P NMR) spectroscopy coupled with enzymatic hydrolysis (EH) with commercially available phosphatases was used to characterize phosphorus (P) compounds in extracts of the dominant aquatic macrophytes and algae in a eutrophic lake. Total extractable organic P (Po) concentrations ranged from 504 to 1643 mg kg−1 and 2318 to 8395 mg kg−1 for aquatic macrophytes and algae, respectively. Using 31P NMR spectroscopy, 11 Po species were detected in the mono- and diester region. Additionally, orthophosphate, pyrophosphate and phosphonates were also detected. Using EH, phytate-like P was identified as the prevalent class of enzyme-labile Po, followed by labile monoester- and diester-P. Comparison of the NMR and EH data indicated that the distribution pattern of major P forms in the samples determined by the two methods was similar (r = 0.712, p < 0.05). Additional 31P NMR spectroscopic analysis of extracts following EH showed significant decreases in the monoester and pyrophosphate regions, with a corresponding increase in the orthophosphate signal, as compared to unhydrolyzed extracts. Based on these quantity and hydrolysis data, we proposed that recycling of Po in vegetative biomass residues is an important mechanism for long-term self-regulation of available P for algal blooming in eutrophic lakes. PMID:27849040

  14. Degradation of black phosphorus: a real-time 31P NMR study

    NASA Astrophysics Data System (ADS)

    Wang, Yue; Yang, Bingchao; Wan, Bensong; Xi, Xuekui; Zeng, Zhongming; Liu, Enke; Wu, Guangheng; Liu, Zhongyuan; Wang, Wenhong

    2016-09-01

    In this work, degradation behaviors and mechanisms of black phosphorus (BP) crystals in air under ambient conditions were investigated by nuclear magnetic resonance spectroscopy. It has been found that the 31P NMR line intensity for BP decreases exponentially during aging even at the very first several hours, suggesting the origin of the degradation of transport properties. In addition to phosphoric acid, new phosphorous acid was also well resolved in the final aging products. Moreover, BP has been found to be stable in water without the presence of oxygen molecules. These findings are relevant for better understanding of degradation behaviors of BP upon aging and should be helpful for overcoming a barrier that might hamper progress toward applications of BP as a 2D material.

  15. Physiologic significance of the phosphorylation potential in isolated perfused rat hearts (/sup 31/P NMR)

    SciTech Connect

    Watters, T.; Wikman-Coffelt, J.; Wu, S.; Wendland, M.; James, T.; Sievers, R.; Botvinick, E.; Parmley, W.

    1986-03-05

    The authors assessed the metabolic and mechanical effects of changes in coronary perfusion pressure (CPP) and afterload (A) in isolated working apex-ejecting rat hearts perfused with Krebs-Henseleit solution containing an excess of O/sub 2/ and substrate. Log(phosphorylation potential) or log (ATP)/(ADP)x (Pi), designated (L), and log (PCR)/(Pi), designated (L*), were calculated from HPLC measurements after rapid freeze-clamping. Increasing CPP from 80-140 cm H/sub 2/O caused an increase in coronary flow(flow), developed pressure(DevP), O/sub 2/ consumption (VO/sub 2/), L, L*, and CO. L and L* were directly related to VO/sub 2/ and CO. Increasing A from 80-140 cm H/sub 2/O caused an increase in DevP and VO/sub 2/, but a decrease in L, L*, and CO. L and L* were inversely linearly related to VO/sub 2/ but were directly linearly related to CO. In both experiments, L and L* are directly related to CO, suggesting that determination of L* (which can be done with /sup 31/P NMR spectroscopy) may be a useful non-invasive method for determining cardiac pump function curves. L and L* may be related to the Frank-Starling mechanism. In a separate experiment using /sup 31/P NMR spectroscopy of isovolumic (left ventricular balloon) perfused rat hearts, increasing CPP caused a direct linear increase in flow, DevP, and L*, confirming the L* results reported above with CPP experiments using the rapid freeze-clamp technique.

  16. Physiologic significance of the phosphorylation potential in isolated perfused rat hearts (31-P NMR)

    SciTech Connect

    Watters, T.; Wikman-Coffelt, J.; Wu, S.; Wendland, M.; James, T.; Sievers, R.; Botvinick, E.; Parmley, W.

    1986-03-05

    The authors assessed the metabolic and mechanical effects of changes in coronary perfusion pressure (CPP) and afterload (A) in isolated working apex-ejecting rat hearts perfused with Krebs-Henseleit solution containing an excess of O/sub 2/ and substrate. Log (phosphorylation potential) or log (ATP)/(ADP)x (Pi), designated (L), and log (PCR)/(Pi), designated (L*), were calculated from HPLC measurements after rapid freeze-clamping. Increasing CPP from 80-140 cm H/sub 2/O caused an increase in coronary flow (flow), developed pressure (DevP), O/sub 2/ consumption (VO/sub 2/), L, L*, and CO. L and L* were directly related to VO/sub 2/ and CO. Increasing A from 80-140 cm H/sub 2/O caused an increase in DevP and VO/sub 2/, but a decrease in L, L*, and CO. L and L* were inversely linearly related to VO/sub 2/ but were directly linearly related to CO. In both experiments, L and L* are directly related to CO, suggesting that determination of L* (which can be done with 31-P NMR spectroscopy) may be a useful non-invasive method for determining cardiac pump function curves. L and L* may be related to the Frank-Starling mechanism. In a separate experiment using 31-P NMR spectroscopy of isovolumic (left ventricular balloon) perfused rat hearts, increasing CPP caused a direct linear increase in flow, DevP, and L*, confirming the L* results reported above with CPP experiments using the rapid freeze-clamp technique.

  17. Detection of Phosphomonoester Signals in Proton-Decoupled 31P NMR Spectra of the Myocardium of Patients with Myocardial Hypertrophy

    NASA Astrophysics Data System (ADS)

    Jung, Wulf-Ingo; Sieverding, Ludger; Breuer, Johannes; Schmidt, Oliver; Widmaier, Stefan; Bunse, Michael; van Erckelens, Franz; Apitz, Jürgen; Dietze, Guenther J.; Lutz, Otto

    1998-07-01

    Proton-decoupled31P NMR spectroscopy at 1.5 T of the anterior left ventricular myocardium was used to monitor myocardial phosphate metabolism in asymptomatic patients with hypertrophic cardiomyopathy (HCM,n= 14) and aortic stenosis (AS,n= 12). In addition to the well-known phosphorus signals a phosphomonoester (PME) signal was detected at about 6.9 ppm in 7 HCM and 2 AS patients. This signal was not observed in the spectra of normal controls (n= 11). We suggest that in spectra of patients with myocardial hypertrophy the presence of a PME signal reflects alterations in myocardial glucose metabolism.

  18. Site-specificity of ethanol-induced dephosphorylation of rat hepatocyte keratins 8 and 18: A 31P NMR study.

    PubMed

    Eckert, B S; Yeagle, P L

    1996-01-01

    Chronic feeding of ethanol to rats results in disorganization of the keratin intermediate filament network within hepatocytes. Previous studies from this laboratory have shown that intermediate filament organization in cultured cells is related to the phosphorylation state of the proteins. Therefore, we have examined the phosphorylation state of hepatocyte keratins from control and ethanol-fed rats. Feeding ethanol to rats results in dephosphorylation of one site on keratin 8 and one site on keratin 18 at all time points beginning with 6 weeks of ethanol treatment. Dephosphorylation was detected by phosphate analysis and by two-dimensional electrophoresis in which a change in isoelectric point of keratins from ethanol-fed rats was observed. These observations indicate that dephosphorylation of keratins in ethanol-fed animals may be an early step in alcoholic hepatitis which has occurred by 6 weeks of ethanol treatment. To further characterize keratin dephosphorylation in ethanol-fed rats, we used 31P NMR spectroscopy to classify the dephosphorylation site(s). Hepatocyte keratins were purified and solubilized in 9.5 M urea, 10 mM Tris-Cl, pH 8.1. 31P NMR spectra were obtained at 109 MHz, in 10 mm tubes at 30 degrees C. Samples of hepatocyte keratins were phosphorylated with A-kinase, protein kinase C, casein kinase II or Ca/CAM kinase and these samples were analyzed by 31P NMR spectroscopy. The resulting spectra were used as standards to compare the 31P chemical shifts of the resonances produced by these kinases with the phosphorus resonances of control and experimental samples. The 31P NMR spectrum of control hepatocyte keratins shows three resonances at 0.7, 4 and 5 ppm. In vitro phosphorylation by A-kinase produces a resonance at 4 ppm which is distinctly different from the resonance produced by each of the other kinases. In hepatocyte keratins from ethanol-fed animals, the resonance at 4 ppm was missing from the spectrum. These observations indicate that the

  19. Using 31P-NMR to investigate dynamics of soil phosphorus compounds in the Rothamsted Long Term Experiments

    NASA Astrophysics Data System (ADS)

    Blackwell, Martin; Turner, Ben; Granger, Steve; Hooper, Tony; Darch, Tegan; Hawkins, Jane; Yuan, Huimin; McGrath, Steve

    2015-04-01

    The technique of 31P-NMR spectroscopy has done more to advance the knowledge of phosphorus forms (especially organic phosphorus) in environmental samples than any other method. The technique has advanced such that specific compounds can be identified where previously only broad categories such as orthophosphate monoesters and diesters were distinguishable. The Soil Archive and Long Term Experiments at Rothamsted Research, UK, potentially provides an unequalled opportunity to use this technique to observe changes in soil phosphorus compounds with time and under different treatments, thereby enhancing our understanding of phosphorus cycling and use by plants. Some of the earliest work using this technique on soils was carried out by Hawkes et al. in 1984 and this used soils from two of the oldest Rothamsted Long Term Experiments, namely Highfield and Park Grass. Here we revisit the samples studied in this early work and reanalyse them using current methodology to demonstrate how the 31P-NMR technique has advanced. We also present results from a study on the phosphorus chemistry in soils along the Hoosfield acid strip (Rothamsted, UK), where a pH gradient from 3.7 to 7.8 occurs in a single soil with little variation in total phosphorus (mean ± standard deviation 399 ± 27 mg P kg-1). Soil pH was found to be an important factor in determining the proportion of phosphomonoesters and phosphodiesters in the soil organic phosphorus, although total organic phosphorus concentrations were a relatively consistent proportion of the total soil phosphorus (36 ± 2%) irrespective of soil pH. Key words. 31P-NMR, soil organic phosphorus, long term experiments, Hoosfield acid strip

  20. 31P-NMR study of resting in vitro rat diaphragm exposed to hypercapnia.

    PubMed

    Fitzgerald, R S; Howell, S; Jacobus, W E

    1988-11-01

    We have reported previously that, when exposed to hypercapnia of various intensities, the diaphragm reduces its force of twitch and tetanic contractions in the in vitro rat preparation as well as in the in vivo dog preparation. The experiments reported here with 31P nuclear magnetic resonance (31P-NMR) spectroscopy attempt to examine cellular mechanisms that might be responsible for this deterioration in mechanical performance. Specifically they describe certain characteristics of this preparation and cautions needed to study the resting in vitro rat diaphragm with such techniques. Second, they report the response of intracellular pH (pHi), phosphocreatine (PCr), ATP, and inorganic phosphate (Pi) in the resting in vitro rat diaphragm exposed to long-term normocapnia or to long-term hypercapnia. The results show that 1) to maintain a viable preparation, it was necessary to keep the diaphragm extended to an area approximating that at functional residual capacity, 2) the diaphragm seemed quite capable of maintaining a constant pHi and constant contents of ATP and Pi during normocapnia, but there was a gradual decline in PCr, and 3) during hypercapnia there was a significant decrease in pHi, but the behavior of the phosphate metabolites was exactly as during normocapnia. The results suggest that the decrease in mechanical performance of the diaphragm is probably not due to a decrease in the availability of the high-energy phosphates, although they do not completely exclude this possibility or possibilities related to regional compartmentation.

  1. TLC and 31P-NMR analysis of low polarity phospholipids.

    PubMed

    Vyssotski, Mikhail; MacKenzie, Andrew; Scott, Dawn

    2009-04-01

    High-performance TLC and (31)P-NMR were assessed as methods of observing the presence of numerous low polarity phospholipids: bis-phosphatidic acid (BPA), semi-lyso bis-phosphatidic acid (SLBPA), N-acyl phosphatidylethanolamine (NAPE), N-(1,1-dimethyl-3-oxo-butyl)-phosphatidylethanolamine (diacetone adduct of PE, DOBPE), N-acetyl PE, phosphatidylmethanol (PM), phosphatidylethanol (PEt), phosphatidyl-n-propanol (PP), phosphatidyl-n-butanol (PB). Both techniques are non-discriminative and do not require the prior isolation of individual lipids. It appears that 2D TLC is superior to (31)P NMR in the analysis of low polarity phospholipids. All phosphatidylalcohols were well separated by 2D TLC. However, some compounds which can present difficulty in separation by 2D-TLC (e.g., SLBPA and NAPE; or DOBPE and N-acetyl PE) were easily distinguished using (31)P NMR so the methods are complimentary. A disadvantage of 2D TLC is that Rf values can vary with different brands and batches of TLC plates. The chemical shifts of (31)P NMR were less variable, and so a library of standards may not be necessary for peak identification. Another advantage of (31)P NMR is the ease of quantification of phospholipids. The applicability of the methods was tested on natural extracts of fish brain and cabbage stem.

  2. Improvement of (31)P NMR spectral resolution by 8-hydroxyquinoline precipitation of paramagnetic Fe and Mn in environmental samples.

    PubMed

    Ding, Shiming; Xu, Di; Li, Bin; Fan, Chengxin; Zhang, Chaosheng

    2010-04-01

    Solution (31)P nuclear magnetic resonance (NMR) spectroscopy is currently the main method for the characterization of phosphorus (P) forms in environment samples. However, identification and quantification of P compounds may be hampered by poor resolution of spectra caused by paramagnetic Fe and Mn. In this study, a novel technique was developed to improve spectral resolution by removing paramagnetic Fe and Mn from alkaline extracts via 8-hydroxyquinoline (8-HOQ) precipitation. Batch experiments showed that both Fe and Mn were effectively removed by the precipitation at pH 9.0, with the removal efficiencies of 83-91% for Fe and 67-78% for Mn from the extracts of five different environmental samples, while little effect was found on concentration of total P. The (31)P NMR analysis of a model P solution showed that addition of 8-HOQ and its precipitation with metal ions did not alter P forms. Further analyses of the five extracts with (31)P NMR spectroscopy demonstrated that the 8-HOQ precipitation was an ideal method compared with the present postextraction techniques, such as bicarbonate dithionate (BD), EDTA and Chelex-100 treatments, by improving spectral resolution to a large extent with no detrimental effects on P forms.

  3. 31P NMR study of erythrocytes from a patient with hereditary pyrimidine-5'-nucleotidase deficiency.

    PubMed Central

    Swanson, M S; Angle, C R; Stohs, S J; Wu, S T; Salhany, J M; Eliot, R S; Markin, R S

    1983-01-01

    The composition of phosphate metabolites and the intracellular pH in erythrocytes from a patient with hereditary pyrimidine-5'-nucleotidase deficiency were examined using 31P NMR spectroscopy. Several resonances were identified in spectra from intact cells and from extracts. The 2,3-bisphosphoglycerate line intensities were normal but the NTP resonances were about twice normal due to the presence of millimolar quantities of pyrimidine phosphates. Several intense resonances were also observed in the diphosphodiester region of the spectrum. One compound contributing to these lines has been identified as cytidine diphosphocholine. The resonances of NTPs were in a position indicating that the additional triphosphates were also bound by Mg2+. Direct measurement shows that there is a nearly proportional increase in total cell Mg2+ in the patient's cells, in agreement with the interpretation of the spectra. The intracellular pH was about 0.2 unit lower in the patient's erythrocytes. This lower pH is due to the elevation in intracellular fixed negative charges and the shift in permeable anions consequent to the Donnan equilibrium. We suggest that the lower intracellular pH may explain the lower oxygen affinity of these cells in the presence of otherwise normal 2,3-bisphosphoglycerate levels and the increased Mg2+ triphosphates level, because the Mg2+ form of NTPs is known not to alter the oxygen affinity of hemoglobin under physiologic conditions. Furthermore, the lower intracellular pH can also explain the abnormalities in glycolytic intermediates observed for these cells. PMID:6296865

  4. 39K, 23Na, and 31P NMR Studies of Ion Transport in Saccharomyces cerevisiae

    NASA Astrophysics Data System (ADS)

    Ogino, T.; den Hollander, J. A.; Shulman, R. G.

    1983-09-01

    The relationship between efflux and influx of K+, Na+, and intracellular pH (pHin) in yeast cells upon energizing by oxygenation was studied by using the noninvasive technique of 39K, 23Na, and 31P NMR spectroscopy. By introducing an anionic paramagnetic shift reagent, Dy3+(P3O105-)2, into the medium, NMR signals of intra- and extracellular K+ and Na+ could be resolved, enabling us to study ion transport processes by NMR. Measurements showed that 40% of the intracellular K+ and Na+ in yeast cells contributed to the NMR intensities. By applying this correction factor, the intracellular ion concentrations were determined to be 130-170 mM K+ and 2.5 mM Na+ for fresh yeast cells. With the aid of a home-built solenoidal coil probe for 39K and a double-tuned probe for 23Na and 31P, we could follow time courses of K+ and Na+ transport and of pHin with a time resolution of 1 min. It was shown that H+ extrusion is correlated with K+ uptake and not with Na+ uptake upon energizing yeast cells by oxygenation. When the cells were deenergized after the aerobic period, K+ efflux, H+ influx, and Na+ influx were calculated to be 1.6, 1.5, and 0.15 μ mol/min per ml of cell water, respectively. Therefore, under the present conditions, K+ efflux is balanced by exchange for H+ with an approximate stoichiometry of 1:1.

  5. CD and 31P NMR studies of tachykinin and MSH neuropeptides in SDS and DPC micelles

    NASA Astrophysics Data System (ADS)

    Schneider, Sydney C.; Brown, Taylor C.; Gonzalez, Javier D.; Levonyak, Nicholas S.; Rush, Lydia A.; Cremeens, Matthew E.

    2016-02-01

    Secondary structural characteristics of substance P (SP), neurokinin A (NKA), neurokinin B (NKB), α-melanocyte stimulating hormone peptide (α-MSH), γ1-MSH, γ2-MSH, and melittin were evaluated with circular dichroism in phosphite buffer, DPC micelles, and SDS micelles. CD spectral properties of γ1-MSH and γ2-MSH as well as 31P NMR of DPC micelles with all the peptides are reported for the first time. Although, a trend in the neuropeptide/micelle CD data appears to show increased α-helix content for the tachykinin peptides (SP, NKA, NKB) and increased β-sheet content for the MSH peptides (α-MSH, γ1-MSH, γ2-MSH) with increasing peptide charge, the lack of perturbed 31P NMR signals for all neuropeptides could suggest that the reported antimicrobial activity of SP and α-MSH might not be related to a membrane disruption mode of action.

  6. [Optimizing the method for 31P-NMR analysis of organic phosphorus from wetland sediments].

    PubMed

    Lu, Jin; Wang, Hai-Wen; Hao, Hong; Gao, Bo; Jia, Jian-Li

    2013-11-01

    Solution 31P-Nuclear Magnetic Resonance (NMR) is an analysis technology which has been an effective means for the analysis of environmental organic phosphorus. However, the method is rarely applied in the study of wetlands so that the corresponding researches about wetland sediment sample preparation method also very deficient. The present study was aimed to find the most suitable sample preparation method for 31P-NMR analysis of the artificial wetland sediments, using different extractant (NaOH or 0.25 mol x L(-1) NaOH + 0.05 mol x L(-1) EDTA as main extractant, and 1M HCl as pre-extractant or not), sample to extractant ratio (1 : 8 or 1 : 10), centrifugation conditions and scans time and so on. The results showed that the best 31P-NMR spectrum could be obtained with freeze-ried, ground and sieved sediments, 1M HCl as pre-extractant for 16 h, NaOH + 0.05 mol x L(-1) EDTA as main extractant for 16 h, extraction ratio of 1 : 8, and low temperature and high-speed centrifugation (4 degrees C, 10 000 r x min(-1) for 30 min) for avoiding hydrolysis of certain components. Besides, choosing much longer NMR scan time, as 14-16 h (scans about 25 000 times), could get more complete spectral signals spectrum. And finally, four kinds of P-compounds (orthophosphate, orthophosphate monoesters, orthophosphate diesters and pyrophosphate) were detected in the NMR spectrum. But neither polyphosphate nor phosphonates was not found in all these experiments, which need further study. Compared with the traditional chemical analysis method, 31P-NMR method of sample preparation is relatively simple. Then it is less destructive with components distinguished completely. Using 31P-NMR technology, the cognition of wetland phosphorus cycle, especially organophosphate, will be expected to get new breakthrough.

  7. Pyrolysis temperature affects phosphorus transformation in biochar: Chemical fractionation and (31)P NMR analysis.

    PubMed

    Xu, Gang; Zhang, You; Shao, Hongbo; Sun, Junna

    2016-11-01

    Phosphorus (P) recycling or reuse by pyrolyzing crop residue has recently elicited increased research interest. However, the effects of feedstock and pyrolysis conditions on P species have not been fully understood. Such knowledge is important in identifying the agronomic and environmental uses of biochar. Residues of three main Chinese agricultural crops and the biochars (produced at 300°C-600°C) derived from these crops were used to determine P transformations during pyrolysis. Hedley sequential fractionation and (31)P NMR analyses were used in the investigation. Our results showed that P transformation in biochar was significantly affected by pyrolysis temperature regardless of feedstock (Wheat straw, maize straw and peanut husk). Pyrolysis treatment transformed water soluble P into a labile (NaHCO3-Pi) or semi-labile pool (NaOH-Pi) and into a stable pool (Dil. HCl P and residual-P). At the same time, organic P was transformed into inorganic P fractions which was identified by the rapid decomposition of organic P detected with solution (31)P NMR. The P transformation during pyrolysis process suggested more stable P was formed at a higher pyrolysis temperature. This result was also evidenced by the presence of less soluble or stable P species, such as such as poly-P, crandallite (CaAl3(OH)5(PO4)2) and Wavellite (Al3(OH)3(PO4)2·5H2O), as detected by solid-state (31)P NMR in biochars formed at a higher pyrolysis temperature. Furthermore, a significant proportion of less soluble pyrophosphate was identified by solution (2%-35%) and solid-state (8%-53%) (31)P NMR, which was also responsible for the stable P forms at higher pyrolysis temperature although their solubility or stability requires further investigation. Results suggested that a relatively lower pyrolysis temperature retains P availability regardless of feedstock during pyrolysis process.

  8. In-depth investigation on quantitative characterization of pyrolysis oil by 31P NMR

    DOE PAGES

    Ben, Haoxi; Ferrell, III, Jack R.

    2016-01-29

    The characterization of different heteroatom functional groups by employing 31P NMR has been developed for almost 30 years. In this study, an in-depth investigation of this commonly used method has been accomplished for the analysis of pyrolysis oil. Several commonly used internal standards for 31P NMR have been examined by in situ monitoring. The results indicated that endo-N-hydroxy-5-norbornene-2,3-dicarboximide (NHND) is not stable after a long period of storage or experiment (>12 hours), but both cyclohexanol and triphenylphosphine oxide (TPPO) can be used as internal standards if a long experiment or storage is required. The pyrolysis oil has also been investigatedmore » by both short time (16 hours) in situ monitoring and long time (14 days) ex situ monitoring. The results showed that aliphatic OH, carboxylic acids and water contents are not very stable after 2 hours, and thus a short time of preparation, storage, and experiment need to be considered to ensure a precise quantitative measurement. The decomposition products are still unclear, but some preliminary investigations for different acids, (e.g. formic acid) have been accomplished. The results indicated that the aromatic carboxylic acids (benzoic acid and vanillic acid) are more stable than formic acid and acetic acid. Interestingly, the formic acid will even decompose to some other compounds at the very beginning of the in situ monitoring test. Further characterization found that water is one of the major products for the decomposition of formic acid in the 31P NMR solution. Finally, as far as we know, this is the first report on such time-dependent changes when using 31P NMR to analyze the pyrolysis oil, and these results show that proper application of this method is essential to achieve reliable quantitative data.« less

  9. Detailed Chemical Composition of Condensed Tannins via Quantitative (31)P NMR and HSQC Analyses: Acacia catechu, Schinopsis balansae, and Acacia mearnsii.

    PubMed

    Crestini, Claudia; Lange, Heiko; Bianchetti, Giulia

    2016-09-23

    The chemical composition of Acacia catechu, Schinopsis balansae, and Acacia mearnsii proanthocyanidins has been determined using a novel analytical approach that rests on the concerted use of quantitative (31)P NMR and two-dimensional heteronuclear NMR spectroscopy. This approach has offered significant detailed information regarding the structure and purity of these complex and often elusive proanthocyanidins. More specifically, rings A, B, and C of their flavan-3-ol units show well-defined and resolved absorbance regions in both the quantitative (31)P NMR and HSQC spectra. By integrating each of these regions in the (31)P NMR spectra, it is possible to identify the oxygenation patterns of the flavan-3-ol units. At the same time it is possible to acquire a fingerprint of the proanthocyanidin sample and evaluate its purity via the HSQC information. This analytical approach is suitable for both the purified natural product proanthocyanidins and their commercial analogues. Overall, this effort demonstrates the power of the concerted use of these two NMR techniques for the structural elucidation of natural products containing labile hydroxy protons and a carbon framework that can be traced out via HSQC.

  10. Phospholipid composition of plasma and erythrocyte membranes in animal species by 31P NMR.

    PubMed

    Ferlazzo, Alida Maria; Bruschetta, Giuseppe; Di Pietro, Patrizia; Medica, Pietro; Notti, Anna; Rotondo, Enrico

    2011-12-01

    The aim of this study was to provide basal values of phospholipid (PL) composition in different animal species by 31P NMR analysis using detergents. This fast and accurate method allowed a quantitative analysis of PLs without any previous separation. Plasma and erythrocyte membrane PLs were investigated in mammals (pig, cow, horse). Moreover, for the first time, the composition of plasma PLs in avian (chicken and ostrich) was performed by 31P NMR. Significant qualitative and quantitative interspecies differences in plasma PL levels were found. Phosphatidilcholine (PC) and sphingomyelin (SPH) levels were significantly higher (P < 0.001) in chicken plasma than all the other species tested. In erythrocytes, cow PC and phosphatidylcholine diarachidoyl were significantly lower (P < 0.001) than for pigs and horses, whereas pig PC presented intermediate values among cows and horses. Inorganic phosphate and 2,3-diphosphoglycerate levels were also significantly different between the species under investigation. The [SPH/total PLs] molar ratios in erythrocytes confirmed interspecies differences in phospholipid composition while the PC/SPH molar ratios could be related to a distinct erythrocyte flexibility and aggregability. Diet and nutrition may contribute primarily to the interspecies differences in plasma PL amounts detected. Significant differences between chicken plasma PC and SPH levels and those of the other animal species could be ascribed to a fat metabolism specific to egg production.

  11. Synthesis of prostanoids; enantiomeric purity of alcohols by a /sup 31/P NMR technique

    SciTech Connect

    Penning, T.D.

    1985-01-01

    The enone, 2,2-diemthyl-3a..beta.., 6a..beta..-dihydro-4H-cyclopenta-1,3-dioxol-4-one, has been synthesized in six steps from cyclopentadiene, resolved using sulfoximine chemistry, and converted into (-)-prostaglandin E/sub 2/ methyl ester in three steps. Introduction of the optically pure omega side-chain using a conjugate addition of a stabilized organocopper reagent, followed by direct alkylation of the enolate with the ..cap alpha.. side-chain allylic iodide in the presence of hexamethylphosphoramide, afforded a trans, vicinally disubstituted cyclopentanone. Deprotection of the C-15 alcohol, followed by aluminum amalgam reduction of the C-10/oxygen bond, provided (-)-PGE/sub 2/ methyl ester in 47% overall yield from the enone. In an extension of previously described work, 2-chloro-3,4-dimethyl-5-phenyl-1,3,2-oxazaphospholidine 2-sulfide, prepared from l-ephedrine and thiophosphoryl chloride, was used to determine the enantiomeric excess of chiral alcohols in conjunction with /sup 31/P NMR. Chiral primary and secondary alcohols added quantitatively to the phospholidine to give diastereomers which could be analyzed by /sup 31/P NMR and HPLC. A number of other phosphorus heterocycles were also explored as potential chiral derivatizing reagents.

  12. Phosphatidylinositol-specific phospholipase C from Bacillus cereus combines intrinsic phosphotransferase and cyclic phosphodiesterase activities: A sup 31 P NMR study

    SciTech Connect

    Shashidhar, M.S.; Kuppe, A. ); Volwerk, J.J.; Griffith, O.H.

    1990-09-04

    The inositol phosphate products formed during the cleavage of phosphatidylinositol by phosphatidylinositol-specific phospholipase C from Bacillus cereus were analyzed by {sup 31}P NMR. {sup 31}P NMR spectroscopy can distinguish between the inositol phosphate species and phosphatidylinositol. Chemical shift values (with reference to phosphoric acid) observed are {minus}0.41, 3.62, 4.45, and 16.30 ppm for phosphatidylinositol, myo-inositol 1-monophosphate, myo-inositol 2-monophosphate, and myo-inositol 1,2-cyclic monophosphate, respectively. It is shown that under a variety of experimental conditions this phospholipase C cleaves phosphatidylinositol via an intramolecular phosphotransfer reaction producing diacylglycerol and D-myo-inositol 1,2-cyclic monophosphate. The authors also report the new and unexpected observation that the phosphatidylinositol-specific phospholipase C from B. cereus is able to hydrolyze the inositol cyclic phosphate to form D-myo-inositol 1-monophosphate. The enzyme, therefore, possesses phosphotransferase and cyclic phosphodiesterase activities. The second reaction requires thousandfold higher enzyme concentrations to be observed by {sup 31}P NMR. This reaction was shown to be regiospecific in that only the 1-phosphate was produced and stereospecific in that only D-myo-inositol 1,2-cyclic monophosphate was hydrolyzed. Inhibition with a monoclonal antibody specific for the B.cereus phospholipase C showed that the cyclic phosphodiesterase activity is intrinsic to the bacterial enzyme. They propose a two-step mechanism for the phosphatidyl-inositol-specific phospholipase C from B. cereus involving sequential phosphotransferase and cyclic phosphodiesterase activities. This mechanism bears a resemblance to the well-known two-step mechanism of pancreatic ribonuclease, RNase A.

  13. Phospholipid fingerprints of milk from different mammalians determined by 31P NMR: towards specific interest in human health.

    PubMed

    Garcia, Cyrielle; Lutz, Norbert W; Confort-Gouny, Sylviane; Cozzone, Patrick J; Armand, Martine; Bernard, Monique

    2012-12-01

    Our objective was to identify and quantify phospholipids in milk from different species (human HM, cow CoM, camel CaM, and mare MM) using an optimised (31)P NMR spectroscopy procedure. The phospholipid fingerprints were species-specific with a broader variety of classes found in HM and MM; HM and CaM were richer in sphingomyelin (78.3 and 117.5μg/ml) and plasmalogens (27.3 and 24μg/ml), possibly important for infant development. Total phospholipid content was higher in CaM (0.503mM) and lower in MM (0.101mM) compared to HM (0.324mM) or CoM (0.265mM). Our optimised method showed good sensitivity, high resolution, and easy sample preparation with minimal loss of target molecules. It is suitable for determining the accurate composition of a large number of bioactive phospholipids with putative health benefits, including plasmalogens, and should aid in selecting appropriate ingredient sources for infant milk substitutes or fortifiers, and for functional foods dedicated to adults.

  14. Exploring new Routes for Identifying Phosphorus Species in Terrestrial and Aquatic Ecosystems with 31P NMR

    NASA Astrophysics Data System (ADS)

    Vestergren, Johan; Persson, Per; Sundman, Annelie; Ilstedt, Ulrik; Giesler, Reiner; Schleucher, Jürgen; Gröbner, Gerhard

    2014-05-01

    Phosphorus (P) is the primary growth-limiting nutrient in some of the world's biomes. Rock phosphate is a non-renewable resource and the major source of agricultural fertilizers. Predictions of P consumption indicate that rock phosphate mining may peak within 35 years, with severe impacts on worldwide food production1. Organic P compounds constitute a major fraction of soil P, but little is known about the dynamics and bioavailability of organic P species. Our aim is to develop new liquid and solid state 31P-NMR (nuclear magnetic resonance) techniques to identify P-species in water and soils; information required for correlating P speciation with plant and soil processes2, and eventually to improve P use. Soil organic P is frequently extracted using NaOH/EDTA, followed by characterization of the extract by solution 31P-NMR. However, the obtained NMR spectra usually have poor resolution due to line broadening caused by the presence of paramagnetic ions. Therefore, we successfully developed an approach to avoid paramagnetic line broadening by precipitation of metal sulfides. Sulfide precipitation dramatically reduces NMR line widths for soil extracts, without affecting P-composition. The resulting highly improved resolution allowed us to apply for the first time 2D 1H,31P-NMR methods to identify different P monoesters in spectral regions which are extremely crowded in 1D NMR spectra.3 By exploiting 2D 1H-31P NMR spectra of soil extracts we were able to unambiguously identify individual organic P species by combining 31P and 1H chemical shifts and coupling constants. This approach is even suitable for a structural characterization of unknown P-components and for tracing degradation pathways between diesters and monoesters3,4.Currently we apply our approach on boreal4 and tropical soils with focus on Burkina Faso. In addition we also monitor P-species in aqueos ecosystems. For this purpose stream water from the Krycklan catchment in northern Sweden5 has been used to

  15. In vivo 31P NMR Study of the Metabolism of Murine Mammary 16/C Adenocarcinoma and Its Response to Chemotherapy, X-Radiation, and Hyperthermia

    NASA Astrophysics Data System (ADS)

    Evanochko, W. T.; Ng, T. C.; Lilly, M. B.; Lawson, A. J.; Corbett, T. H.; Durant, J. R.; Glickson, J. D.

    1983-01-01

    31P NMR spectroscopy with surface coils has been used to monitor, in vivo, the phosphate metabolism of subcutaneously implanted mammary 16/C adenocarcinoma in C3H/He mice. This model tumor was studied during untreated tumor growth and after treatment with adriamycin, hyperthermia, and x-radiation. The mammary 16/C tumor exhibited a Gompertzian growth pattern. Levels of high-energy phosphate metabolites--phosphocreatine and ATP--decreased with increases in tumor mass. There was a concomitant increase in the level of Pi and a decrease in the apparent pH of the tumor. These spectral changes appear to reflect changes in tumor vascularization that accompany tumor growth, the tumor becoming progressively more hypoxic. Partial response of this tumor to chemotherapy with adriamycin was reflected in a small but measurable increase in the phosphocreatine resonance, a decrease in Pi, and a return of the intratumor pH to neutral. Hyperthermia resulted in progressive conversion of the 31P NMR spectrum to that of a dead tumor (high levels of Pi, small levels of residual sugar phosphates and pyridine dinucleotides, and acidic pH). X-irradiation (14.0 Gy) led to disappearance of the phosphocreatine peak within 15 min of treatment. Subsequently, this resonance grew back beyond its pretreatment level. As the tumor receded, its spectrum reflected the characteristics of aerobically metabolizing tissue (high levels of phosphocreatine and ATP and low levels of Pi and sugar phosphates).

  16. Modified Prony Method to Resolve and Quantify in Vivo31P NMR Spectra of Tumors

    NASA Astrophysics Data System (ADS)

    Barone, P.; Guidoni, L.; Ragona, R.; Viti, V.; Furman, E.; Degani, H.

    Prony's method, successfully used in processing NMR signals, performs poorly at low signal-to-noise ratios. To overcome this problem, a statistical approach has been adopted by using Prony's method as a sampling device from the distribution associated with the true spectrum. Specifically, Prony's method is applied for each regression order p and number of data points n, both considered in a suitable range, and the estimates of frequencies, amplitudes, and decay factors are pooled separately. A histogram of the pooled frequencies is computed and, looking at the histogram, a lower and an upper frequency bound for each line of interest is determined. All frequency estimates in each of the determined intervals as well as associated decay factors and amplitudes are considered to be independent normal variates. A mean value and a corresponding 95% confidence interval are computed for each parameter. 31P NMR signals from MCF7 human breast cancer cells, inoculated into athymic mice and which developed into tumors, have been processed with traditional methods and with this modified Prony's method. The main components of the phosphomonoester peak, namely those deriving from phosphorylcholine and phosphorylethanolamine, are always well resolved with this new approach and their relative amplitudes can be consequently evaluated. Peak intensities of these two signals show different behavior during treatment of tumors with the antiestrogenic drug tamoxifen. The results of this new approach are compared with those obtainable with traditional techniques.

  17. Towards the versatile DFT and MP2 computational schemes for 31P NMR chemical shifts taking into account relativistic corrections.

    PubMed

    Fedorov, Sergey V; Rusakov, Yury Yu; Krivdin, Leonid B

    2014-11-01

    The main factors affecting the accuracy and computational cost of the calculation of (31)P NMR chemical shifts in the representative series of organophosphorous compounds are examined at the density functional theory (DFT) and second-order Møller-Plesset perturbation theory (MP2) levels. At the DFT level, the best functionals for the calculation of (31)P NMR chemical shifts are those of Keal and Tozer, KT2 and KT3. Both at the DFT and MP2 levels, the most reliable basis sets are those of Jensen, pcS-2 or larger, and those of Pople, 6-311G(d,p) or larger. The reliable basis sets of Dunning's family are those of at least penta-zeta quality that precludes their practical consideration. An encouraging finding is that basically, the locally dense basis set approach resulting in a dramatic decrease in computational cost is justified in the calculation of (31)P NMR chemical shifts within the 1-2-ppm error. Relativistic corrections to (31)P NMR absolute shielding constants are of major importance reaching about 20-30 ppm (ca 7%) improving (not worsening!) the agreement of calculation with experiment. Further better agreement with the experiment by 1-2 ppm can be obtained by taking into account solvent effects within the integral equation formalism polarizable continuum model solvation scheme. We recommend the GIAO-DFT-KT2/pcS-3//pcS-2 scheme with relativistic corrections and solvent effects taken into account as the most versatile computational scheme for the calculation of (31)P NMR chemical shifts characterized by a mean absolute error of ca 9 ppm in the range of 550 ppm.

  18. A Wet-Lab Approach to Stereochemistry Using [superscript 31]P NMR Spectroscopy

    ERIC Educational Resources Information Center

    Fenton, Owen S.; Sculimbrene, Bianca R.

    2011-01-01

    Understanding stereochemistry is an important and difficult task for students to master in organic chemistry. In both introductory and advanced courses, students are encouraged to explore the spatial relationships between molecules, but this exploration is often limited either to the lecture hall or the confines of the library. As such, we sought…

  19. Assessment of membrane protection by /sup 31/P-NMR effects of lidocaine on calcium-paradox in myocardium

    SciTech Connect

    Sakai, Hirosumi; Yoshiyama, Minoru; Teragaki, Masakazu; Takeuchi, Kazuhide; Takeda, Takeda; Ikata, Mari; Ishikawa, Makoto; Miura, Iwao

    1989-01-01

    In studying calcium paradox, perfused rat hearts were used to investigate the myocardial protective effects of lidocaine. Intracellular contents of phosphates were measured using the /sup 31/P-NMR method. In hearts reexposed to calcium, following 3 minute calcium-free perfusion, a rapid contracture occurred, followed by rapid and complete disappearance of intracellular phosphates with no resumption of cardiac function. In hearts where lidocaine was administered from the onset of the calcium-free perfusion until 2 minutes following the onset of reexposure to calcium, both intracellular phosphates and cardiac contractility were maintained. Therefore, it can be said that cell membranes were protected by lidocaine.

  20. Phytate degradation by lactic acid bacteria and yeasts during the wholemeal dough fermentation: a 31P NMR study.

    PubMed

    Reale, Anna; Mannina, Luisa; Tremonte, Patrizio; Sobolev, Anatoli P; Succi, Mariantonietta; Sorrentino, Elena; Coppola, Raffaele

    2004-10-06

    myo-Inositol hexaphosphate (IP6) is the main source of phosphorus in cereal grains, and therefore, in bakery products. Different microorganisms such as yeasts and lactic acid bacteria have phytase enzymes able to hydrolyze IP6 during the wholemeal breadmaking. In this paper, the phytase activity of Lactobacillus plantarum, Lactobacillus brevis, Lactobacillus curvatus, and Saccharomyces cerevisiae strains, isolated from southern Italian sourdoughs, is assayed using the (31)P NMR technique. The sourdough technology based on the use of lactic acid bacteria in the breadmaking is finally suggested.

  1. /sup 31/P NMR analysis of membrane phospholipid organization in viable, reversibly electropermeabilized Chinese hamster ovary cells

    SciTech Connect

    Lopez, A.; Rols, M.P.; Teissie, J.

    1988-02-23

    Chinese hamster ovary (CHO) cells were reversibly permeabilized by submitting them to short, high-intensity, square wave pulses (1.8 kV/cm, 100 ..mu..s). The cells remained in a permeable state without loss of viability for several hours at 4/sup 0/C. A new anisotropic peak with respect to control cells was observed on /sup 31/P NMR spectroscopic analysis of the phospholipid components. This peak is only present when the cells are permeable, and normal anisotropy is recovered after resealing. Taking into account the fusogenicity of electropermeabilized cells, comparative studies were performed on 5% poly(ethylene glycol) treated cells. The /sup 31/P NMR spectra of the phospholipids displayed the same anisotropic peak as in the case of the electropermeabilized cells. In the two cases, this anisotropic peak was located downfield from the main peak associated to the phospholipids when organized in bilayers. The localization of this anisotropic peak is very different from the one of a hexagonal phase. The authors proposed a reorganization of the polar head group region leading to a weakening of the hydration layer to account for these observations. This was also thought to explain the electric field induced fusogenicity of these cells.

  2. Ab initio and DFT study of 31P-NMR chemical shifts of sphingomyelin and dihydrosphingomyelin lipid molecule

    NASA Astrophysics Data System (ADS)

    Sugimori, K.; Kawabe, H.; Nagao, H.; Nishikawa, K.

    One of the phospholipids, sphingomyelin (SM, N-acyl-sphingosine-1-phosphorylcholine) is the most abundant component of mammalian membranes in brain, nervous tissues, and human ocular lens. It plays an important role for apoptosis, aging, and signal transduction. Recently, Yappert and coworkers have shown that human lens sphingomyelin and its hydrogenated derivative, dihydrosphingomyelin (DHSM) are interacted with Ca2+ ions to develop human cataracts. Previously, we have investigated conformational differences between an isolated SM/DHSM molecule and Ca2+-coordinated form by using density functional theory (DFT) for geometry optimization and normal mode analysis. As a result, one of stable conformers of SMs has a hydrogen bonding between hydroxyl group and phosphate group, whereas another conformer has a hydrogen bonding between hydroxyl and phosphate amide group. In this study, 31P-Nuclear Magnetic Resonance (NMR) shielding constants of the obtained conformers are investigated by using ab initio and DFT with NMR-gauge invariant atomic orbitals (NMR-GIAO) calculations. The experimental 31P-NMR chemical shifts of SMs and DHSMs have significant small value around 0.1 ppm. We consider the relative conformational changes between SMs and DHSMs affect the slight deviations of 31P-NMR chemical shifts, and discuss intramolecular hydrogen bondings and the solvent effect in relation to NMR experimental reference.

  3. Geographical characterization of greek virgin olive oils (cv. Koroneiki) using 1H and 31P NMR fingerprinting with canonical discriminant analysis and classification binary trees.

    PubMed

    Petrakis, Panos V; Agiomyrgianaki, Alexia; Christophoridou, Stella; Spyros, Apostolos; Dais, Photis

    2008-05-14

    This work deals with the prediction of the geographical origin of monovarietal virgin olive oil (cv. Koroneiki) samples from three regions of southern Greece, namely, Peloponnesus, Crete, and Zakynthos, and collected in five harvesting years (2001-2006). All samples were chemically analyzed by means of 1H and 31P NMR spectroscopy and characterized according to their content in fatty acids, phenolics, diacylglycerols, total free sterols, free acidity, and iodine number. Biostatistical analysis showed that the fruiting pattern of the olive tree complicates the geographical separation of oil samples and the selection of significant chemical compounds. In this way the inclusion of the harvesting year improved the classification of samples, but increased the dimensionality of the data. Discriminant analysis showed that the geographical prediction at the level of three regions is very high (87%) and becomes (74%) when we pass to the thinner level of six sites (Chania, Sitia, and Heraklion in Crete; Lakonia and Messinia in Peloponnesus; Zakynthos). The use of classification and binary trees made possible the construction of a geographical prediction algorithm for unknown samples in a self-improvement fashion, which can be readily extended to other varieties and areas.

  4. sup 31 P NMR measurements of the ADP concentration in yeast cells genetically modified to express creatine kinase

    SciTech Connect

    Brindle, K.; Braddock, P.; Fulton, S. )

    1990-04-03

    Rabbit muscle creatine kinase has been introduced into the yeast Saccharomyces cerevisiae by transforming cells with a multicopy plasmid containing the coding sequence for the enzyme under the control of the yeast phosphoglycerate kinase promoter. The transformed cells showed creating kinase activities similar to those found in mammalian heart muscle. {sup 31}P NMR measurements of the near-equilibrium concentrations of phosphocreatine and cellular pH together with measurements of the total extractable concentrations of phosphocreatine and creatine allowed calculation of the free ADP/ATP ratio in the cell. The calculated ratio of approximately 2 was considerably higher than the ratio of between 0.06 and 0.1 measured directly in cell extracts.

  5. Preservation of bilayer structure in human erythrocytes and erythrocyte ghosts after phospholipase treatment. A 31P-NMR study.

    PubMed

    van Meer, G; de Kruijff, B; op den Kamp, J A; van Deenen, L L

    1980-02-15

    1. Fresh human erythrocytes were treated with lytic and non-lytic combinations of phospholipases A2, C and sphingomyelinase. The 31P-NMR spectra of ghosts derived from such erythrocytes show that, in all cases, the residual phospholipids and lysophospholipids remain organized in a bilayer configuration. 2. A bilayer configuration of the (lyso)phospholipids was also observed after treatment of erythrocyte ghosts with various phospholipases even in the case that 98% of the phospholipid was converted into lysophospholipid (72%) and ceramides (26%). 3. A slightly decreased order of the phosphate group of phospholipid molecules, seen as reduced effective chemical shift anisotropy in the 31P-NMR spectra, was found following the formation of diacyglycerols and ceramides in the membrane of intact erythrocytes. Treatment of ghosts always resulted in an extensive decrease in the order of the phosphate groups. 4. The results allow the following conclusions to made: a. Hydrolysis of phospholipids in intact red cells and ghosts does not result in the formation of non-bilayer configuration of residual phospholipids and lysophospholipids. b. Haemolysis, which is obtained by subsequent treatment of intact cells with sphingomyelinase and phospholipase A2, or with phospholipase C, cannot be ascribed to the formation of non-bilayer configuration of phosphate-containing lipids. c. Preservation of bilayer structure, even after hydrolysis of all phospholipid, shows that other membrane constitutents, e.g. cholesterol and/or membrane proteins play an important role in stabilizing the structure of the erythrocyte membrane. d. A major prerequisite for the application of phospholipases in lipid localization studies, the preservation of a bilayer configuration during phospholipid hydrolysis, is met for the erythrocyte membrane.

  6. A 31P-NMR study of the interaction of Mg2+ ions with nucleoside diphosphates.

    PubMed Central

    Tran-Dinh, S; Neumann, J M

    1977-01-01

    The interaction of Mg2+ with nucleoside disphosphates : ADP, GDP, CDP and UDP has been studied by phosphorus magnetic resonance spectroscopy in aqueous solution. The results show that these four nucleotides behave similarly, the Mg2+ ion binds to the alpha but not to the beta phosphate moiety. The strength of the interaction of Mg2+ ions with nucleoside diphosphates is weaker than with nucleoside triphosphates. The association of Mg2+ on the phosphate chain is stronger in a neutral than in an acid medium. PMID:14328

  7. 13C and 31P NMR for the diagnosis of muscular phosphorylase-kinase deficiency

    NASA Astrophysics Data System (ADS)

    Jehenson, P.; Duboc, D.; Laforet, P.; Eymard, B.; Lombès, A.; Fardeau, M.; Brunet, P.; Syrota, A.

    1998-02-01

    To further develop and specify the range of medical applications of in vivo NMR spectroscopy for the study of myopathies, it is ncessary to study the largest number of well characterized cases. We here report on the 31P and 13C NMR study of a purely muscular form of phosphorylase-kinase (PK) deficiency. Abnormalities were observed that agree with and increase our pathophysiological knowledge, in particular on the activation of phosphorylase and PK. Also, the abnormalities are different from those found in other clinically similar metabolic myopathies and could be used for the differential diagnosis. Afin de continuer à développer et préciser les applications médicales de la spectroscopie RMN in vivo, il faut étudier le plus grand nombre possible de cas bien caractérisés. Nous avons étudié ici une forme purement musculaire de déficit en phosphorylase-kinase (PK) par RMN du phosphore 31 et du carbone 13. Les altérations observées sont en accord avec et augmentent nos connaissances physiopathologiques, par exemple concernant l'activation de la phosphorylase et PK. Par ailleurs, la combinaison d'altérations observées en 31P et 13C est différente de celle retrouvée dans d'autres myopathies métaboliques cliniquement semblables et pourrait être utilisée pour le diagnostic différentiel.

  8. Direct and simultaneous quantification of ATP, ADP and AMP by (1)H and (31)P Nuclear Magnetic Resonance spectroscopy.

    PubMed

    Lian, Yakun; Jiang, Hua; Feng, Jinzhou; Wang, Xiaoyan; Hou, Xiandeng; Deng, Pengchi

    2016-04-01

    ATP, ADP and AMP are energy substances with vital biological significance. Based on the structural differences, a simple, rapid and comprehensive method has been established by (1)H and (31)P Nuclear Magnetic Resonance ((1)H-NMR and (31)P-NMR) spectroscopies. Sodium 3-(trimethylsilyl) propionate-2,2,3,3-d4 (TMSP) and anhydrous disodium hydrogen phosphate (Na2HPO4) were selected as internal standards for (1)H-NMR and (31)P-NMR, respectively. Those three compounds and corresponding internal standards can be easily distinguished both by (1)H-NMR and (31)P-NMR. In addition, they all have perfect linearity in a certain range: 0.1-100mM for (1)H-NMR and 1-75 mM for (31)P-NMR. To validate the precision of this method, mixed samples of different concentrations were measured. Recovery experiments were conducted in serum (91-113% by (1)H-NMR and 89-113% by (31)P-NMR).

  9. Quantitative 31P NMR analysis of solid wood offers an insight into the acetylation of its components.

    PubMed

    Sadeghifar, Hasan; Dickerson, James P; Argyropoulos, Dimitris S

    2014-11-26

    As a solid substrate, wood and its components are almost invariably examined via spectroscopic or indirect methods of analysis. Unlike earlier approaches, in this effort we dissolve pulverized wood in ionic liquid and then directly derive its functional group contents by quantitative (31)P NMR. As such, this novel analytical methodology is thoroughly examined and an insight into the detailed way acetylation proceeds on solid wood and its components is provided as a function of wood density and within its various anatomical features. As anticipated, the efficiency of acetylation was found to be greater within low density wood than in high density wood. The lignin, the cellulose and the hemicelluloses of the low density wood was found to be acetylated nearly twice as fast with remarkable differences in their quantitative degree of acetylation amongst them. This direct analytical data validates the applied methodology and confirms, for the first time, that the order of acetylation in solid wood is lignin>hemicellulose>cellulose and no reactivity differences exist between early wood and late wood.

  10. Functional pools of fast and slow twitch fibers observed by /sup 31/P-NMR during exercise of flexor wrist muscles in man

    SciTech Connect

    Park, J.H.; Park, C.R.; Brown, R.L.; Chance, B.

    1987-05-01

    Functional compartments of fast and slow twitch fibers have been observed by /sup 31/P-NMR spectroscopy during exercise of the wrist flexor muscles in a sedentary, young male subject. Values of Pi, phosphocreatine (PCr) and adenine nucleotides were determined at rest and during an exercise protocol. The subject flexed his wrist muscles at 20% of maximum strength every 5 sec for 6 min and then increased his effort in the next two 6 min intervals to 40% and 60% of maximum. With exercise, the Pi/PCr rose rapidly to the exceptionally high value of 2.2 at 60% effort. As the Pi increased, the initial single peak (pH 7.0-6.9) split into two distinct components with pH values of 6.8 and 6.3. Quantitatively, distribution of the Pi was 40% in the pH 6.8 peak and 60% in the pH 6.3 peak as determined by area estimation following curve fitting. This presumably reflects two pools of Pi corresponding to the oxidative (slow twitch, high pH) and glycolytic (fast twitch, low pH) fibers. In the second identical exercise sequence which followed immediately, only one Pi peak (pH 6.8-6.9) appeared. This suggested that the glycolytic contribution to energy production was largely exhausted and the residual energy was derived from oxidative metabolism. During exercise at high levels, total phosphate decreased due primarily to loss of NMR visible adenine nucleotides. Similar phenomena have been observed in three other sedentary individuals, but not in trained athletes.

  11. Direct Speciation of Phosphorus in Alum-Amended Poultry Litter: Solid-State 31P NMR Investigation

    SciTech Connect

    Hunger, Stefan; Cho, Herman M.; Sims, James T.; Sparks, Donald L.

    2004-02-01

    Amending poultry litter (PL) with aluminum sulfate (alum) has proven to be effective in reducing water-soluble phosphorus (P) in the litter and in runoff from fields that have received PL applications; it has therefore been suggested as a best management practice. Although its effectiveness has been demonstrated on a macroscopic scale in the field, little is known about P speciation in either alumamended or unamended litter. This knowledge is important for the evaluation of the long-term stability and bioavailability of P, which is a necessary prerequisite for the assessment of the sustainability of intensive poultry operations. Both solid state MAS and CP-MAS {sup 31}P NMR as well as {sup 31}P({sup 27}Al) TRAPDOR were used to investigate P speciation in alumamended and unamended PL. The results indicate the presence of a complex mixture of organic and inorganic orthophosphate phases. A calcium phosphate phase, probably a surface precipitate on calcium carbonate, could be identified in both unamended and alum-amended PL, as well as physically bound HPO{sub 4}{sup 2-}. Phosphate associated with Al was found in the alum-amended PL, most probably a mixture of a poorly ordered wavellite and phosphate surface complexes on aluminum hydroxide that had been formed by the hydrolysis of alum. However, a complex mixture of organic and inorganic phosphate species could not be resolved. Phosphate associated with Al comprised on average 40{+-}14% of the total P in alum-amended PL, whereas calcium phosphate phases comprised on average 7{+-}4% in the alum-amended PL and 14{+-}5% in the unamended PL.

  12. Thermotropic phase behavior of model membranes composed of phosphatidylcholines containing cis-monounsaturated acyl chain homologues of oleic acid: differential scanning calorimetric and /sup 31/P NMR spectroscopic studies

    SciTech Connect

    Lewis, R.N.A.H.; Sykes, B.D.; McElhaney, R.N.

    1988-02-09

    The thermotropic phase behavior of dioleoylphosphatidylcholine and six of its longer chain homologues was studied by differential scanning calorimetry and /sup 31/P nuclear magnetic resonance (NMR) spectroscopy. Aqueous dispersions of these compounds all exhibit a single endotherm upon heating but upon cooling exhibit at least two exotherms, both of which occur at temperatures lower than those of their heating endotherm. The single transition observed upon heating was shown by /sup 31/P NMR spectroscopy to be a net conversion from a condensed, subgel-like phase (L/sub c/ phase) to the liquid-crystalline state. Aqueous ethylene glycol dispersions of these compounds also exhibit single endotherms upon heating and cooling exotherms centered at temperatures lower than those of their corresponding heating endotherm. However, the behavior of the aqueous ethylene glycol dispersions differs with respect to their transition temperatures and enthalpies as well as the extent of undercooling observed, and there is some evidence of discontinuities in the cooling behavior of the odd- and even-numbered members of the homologous series. Like the aqueous dispersions, /sup 31/P NMR spectroscopy also shows that the calorimetric events observed in aqueous ethylene glycol involve net interconversions between an L/sub c/-like phase and the liquid-crystalline state. These results demonstrate that although the presence of a cis double bond can perturb the solid-state packing of the acyl chains, its presence does not preclude the formation of highly ordered subgel-like phases in lipid bilayers. In the particular case of these unsaturated phosphatidylcholines, the formation of the subgel phases is more kinetically favorable than is the case with their saturated n-acyl counterparts.

  13. Ionization behavior of polyphosphoinositides determined via the preparation of pH titration curves using solid-state 31P NMR.

    PubMed

    Graber, Zachary T; Kooijman, Edgar E

    2013-01-01

    Detailed knowledge of the degree of ionization of lipid titratable groups is important for the evaluation of protein-lipid and lipid-lipid interactions. The degree of ionization is commonly evaluated by acid-base titration, but for lipids localized in a multicomponent membrane interface this is not a suitable technique. For phosphomonoester-containing lipids such as the polyphosphoinositides, phosphatidic acid, and ceramide-1-phosphate, this is more conveniently accomplished by (31)P NMR. Here, we describe a solid-state (31)P NMR procedure to construct pH titration curves to determine the degree of ionization of phosphomonoester groups in polyphosphoinositides. This procedure can also be used, with suitable sample preparation conditions, for other important signaling lipids. Access to a solid-state, i.e., magic angle spinning, capable NMR spectrometer is assumed. The procedures described here are valid for a Bruker instrument, but can be adapted for other spectrometers as needed.

  14. Correcting human heart 31P NMR spectra for partial saturation. Evidence that saturation factors for PCr/ATP are homogeneous in normal and disease states

    NASA Astrophysics Data System (ADS)

    Bottomley, Paul A.; Hardy, Christopher J.; Weiss, Robert G.

    Heart PCr/ATP ratios measured from spatially localized 31P NMR spectra can be corrected for partial saturation effects using saturation factors derived from unlocalized chest surface-coil spectra acquired at the heart rate and approximate Ernst angle for phosphor creatine (PCr) and again under fully relaxed conditions during each 31P exam. To validate this approach in studies of normal and disease states where the possibility of heterogeneity in metabolite T1 values between both chest muscle and heart and normal and disease states exists, the properties of saturation factors for metabolite ratios were investigated theoretically under conditions applicable in typical cardiac spectroscopy exams and empirically using data from 82 cardiac 31P exams in six study groups comprising normal controls ( n = 19) and patients with dilated ( n = 20) and hypertrophic ( n = 5) cardiomyopathy, coronary artery disease ( n = 16), heart transplants ( n = 19), and valvular heart disease ( n = 3). When TR ≪ T1,(PCr), with T1(PCr) ⩾ T1(ATP), the saturation factor for PCr/ATP lies in the range 1.5 ± 0.5, regardless of the T1 values. The precise value depends on the ratio of metabolite T1 values rather than their absolute values and is insensitive to modest changes in TR. Published data suggest that the metabolite T1 ratio is the same in heart and muscle. Our empirical data reveal that the saturation factors do not vary significantly with disease state, nor with the relative fractions of muscle and heart contributing to the chest surface-coil spectra. Also, the corrected myocardial PCr/ATP ratios in each normal or disease state bear no correlation with the corresponding saturation factors nor the fraction of muscle in the unlocalized chest spectra. However, application of the saturation correction (mean value, 1.36 ± 0.03 SE) significantly reduced scatter in myocardial PCr/ATP data by 14 ± 11% (SD) ( p ⩽ 0.05). The findings suggest that the relative T1 values of PCr and ATP are

  15. Simultaneously cycled NMR spectroscopy.

    PubMed

    Parish, David M; Szyperski, Thomas

    2008-04-09

    Simultaneously cycled (SC) NMR was introduced and exemplified by implementing a set of 2-D [1H,1H] SC exclusive COSY (E.COSY) NMR experiments, that is, rf pulse flip-angle cycled (SFC), rf pulse phase cycled (SPC), and pulsed field gradient (PFG) strength cycled (SGC) E.COSY. Spatially selective 1H rf pulses were applied as composite pulses such that all steps of the respective cycles were affected simultaneously in different slices of the sample. This increased the data acquisition speed for an n-step cycle n-fold. A high intrinsic sensitivity was achieved by defining the cycles in a manner that the receiver phase remains constant for all steps of the cycle. Then, the signal resulting from applying the cycle corresponded to the sum of the signals from all steps of the cycle. Hence, the detected free induction decay did not have to be separated into the contributions arising from different slices, and read-out PFGs, which not only greatly reduce sensitivity but also negatively impact lineshapes in the direct dimension, were avoided. The current implementation of SFC E.COSY reached approximately 65% of the intrinsic sensitivity of the conventional phase cycled congener, making this experiment highly attractive whenever conventional data acquisition is sampling limited. Highly resolved SC E.COSY yielding accurate 3J-coupling values was recorded for the 416 Da plant alkaloid tomatidine within 80 min, that is, 12 times faster than with conventional phase cycled E.COSY. SC NMR is applicable for a large variety of NMR experiments and thus promises to be a valuable addition to the arsenal of approaches for tackling the NMR sampling problem to avoid sampling limited data acquisition.

  16. Differently saturated fatty acids can be differentiated by 31P NMR subsequent to derivatization with 2-chloro-4,4,5,5-tetramethyldioxaphospholane: a cautionary note.

    PubMed

    Eibisch, Mandy; Riemer, Thomas; Fuchs, Beate; Schiller, Jürgen

    2013-03-20

    The analysis of free fatty acid (FFA) mixtures is a very important but, even nowadays, challenging task. This particularly applies as the so far most commonly used technique-gas chromatography/mass spectrometry (GC/MS)-is tedious and time-consuming. It has been convincingly shown ( Spyros, A.; Dais, P. J. Agric. Food Chem. 2000, 48, 802 - 5) that FFA may be analyzed by (31)P NMR subsequent to derivatization with 2-chloro-4,4,5,5-tetramethyldioxaphospholane (CTDP). However, it was also indicated that differently unsaturated FFAs result in the same (31)P NMR chemical shift and cannot be differentiated. Therefore, only the overall fatty acid content of a sample can be determined by the CTDP assay. In contrast, we will show here by using high-field NMR (600 MHz spectrometer, i.e., 242.884 MHz for (31)P) that the CTDP assay may be used to differentiate FFAs that have pronounced differences in their double bond contents: saturated fatty acids (16:0), moderately unsaturated (18:1, 18:2), highly unsaturated (20:4), and extremely unsaturated fatty acids (22:6) result in slightly different chemical shifts. The same applies for oxidized fatty acids. Finally, it will also be shown that the CTDP derivatization products decompose in a time-dependent manner. Therefore, all investigations must adhere to a strict time regime.

  17. 31P NMR characterization and efficiency of new types of water-insoluble phosphate fertilizers to supply plant-available phosphorus in diverse soil types.

    PubMed

    Erro, Javier; Baigorri, Roberto; Yvin, Jean-Claude; Garcia-Mina, Jose M

    2011-03-09

    Hydroponic plant experiments demonstrated the efficiency of a type of humic acid-based water-insoluble phosphate fertilizers, named rhizosphere controlled fertilizers (RCF), to supply available phosphorus (P) to different plant species. This effect was well correlated to the root release of specific organic acids. In this context, the aims of this study are (i) to study the chemical nature of RCF using solid-state (31)P NMR and (ii) to evaluate the real efficiency of RCF matrix as a source of P for wheat plants cultivated in an alkaline and acid soil in comparison with traditional water-soluble (simple superphosphate, SSP) and water-insoluble (dicalcium phosphate, DCP) P fertilizers. The (31)P NMR study revealed the formation of multimetal (double and triple, MgZn and/or MgZnCa) phosphates associated with chelating groups of the humic acid through the formation of metal bridges. With regard to P fertilizer efficiency, the results obtained show that the RCF matrix produced higher plant yields than SSP in both types of soil, with DCP and the water-insoluble fraction from the RCF matrix (WI) exhibiting the best results in the alkaline soil. By contrast, in the acid soil, DCP showed very low efficiency, WI performed on a par with SSP, and RCF exhibited the highest efficiency, thus suggesting a protector effect of humic acid from soil fixation.

  18. In vitro (31)P NMR studies on biopsy skeletal muscle samples compared with meat quality of normal and heterozygous malignant hyperthermia pigs.

    PubMed

    Lahucky, R; Baulain, U; Henning, M; Demo, P; Krska, P; Liptaj, T

    2002-07-01

    Phosphorus nuclear magnetic resonance ((31)P NMR) measurements were made to determine muscle energetic metabolism on muscle biopsy samples of heterozygote malignant hyperthermia (Nn) and normal (NN) pigs DNA tested on occurrence of mutation in RYR 1 gene. Biopsy samples (approx. 1 g) were obtained by spring-loaded biopsy instrument (Biotech, Slovakia) from Longissimus dorsi (LD) muscle at 80 kg live weight. The spectra were recorded at 121 MHz on a VXR 300 (Varian) spectrometer in 10 mm diameter tube (maintained at 39 °C) for 50 min. pH of bioptates after NMR measurements were also measured at 60 min. The changes in inorganic phosphate (Pi), phosophocreatine (PCr) and adenosine triphosphate (ATP) were faster in heterozygote malignant hyperthermia (MH; 29 crossbred White Meaty×Pietrain) than in normal (13 Duroc, Yorkshire and White Meaty). The values of PCr at 20 min and pH at 60 min after taking biopsy allowed discrimination between NN and Nn pigs and significant (P<0.05) differences were also found between two subgroups in heterozygote MH pigs with different rate of post mortem muscle metabolism. The values of PCr and pH as measured at definite time on the biopsies, were significantly (P<0.05) correlated with the rate of post mortem metabolism (pH) and with meat quality traits (r approx. 0.4-0.6). The (31)P NMR measurements pointed to impaired muscle energetic metabolism connected with the occurrence of mutation on the RYR 1 gene in heterozygote MH pigs.

  19. Forms and lability of phosphorus in algae and aquatic macrophytes characterized by solution 31P NMR coupled with enzymatic hydrolysis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Increased information on forms and lability of phosphorus (P) in aquatic macrophytes and algae is crucial for better understanding of P biogeochemical cycling in eutrophic lakes. In this work, solution 31P nuclear magnetic resonance (NMR) spectroscopy coupled with enzymatic hydrolysis (EH) was used ...

  20. Simultaneous beta and gamma spectroscopy

    DOEpatents

    Farsoni, Abdollah T.; Hamby, David M.

    2010-03-23

    A phoswich radiation detector for simultaneous spectroscopy of beta rays and gamma rays includes three scintillators with different decay time characteristics. Two of the three scintillators are used for beta detection and the third scintillator is used for gamma detection. A pulse induced by an interaction of radiation with the detector is digitally analyzed to classify the type of event as beta, gamma, or unknown. A pulse is classified as a beta event if the pulse originated from just the first scintillator alone or from just the first and the second scintillator. A pulse from just the third scintillator is recorded as gamma event. Other pulses are rejected as unknown events.

  1. On the use of 31P NMR for the quantification of hydrosoluble phosphorus-containing compounds in coral host tissues and cultured zooxanthellae

    NASA Astrophysics Data System (ADS)

    Godinot, Claire; Gaysinski, Marc; Thomas, Olivier P.; Ferrier-Pagès, Christine; Grover, Renaud

    2016-02-01

    31P Nuclear Magnetic Resonance (NMR) was assessed to investigate the phosphorus-containing compounds present in the tissues of the scleractinian coral Stylophora pistillata as well as of cultured zooxanthellae (CZ). Results showed that phosphorus-containing compounds observed in CZ were mainly phosphate and phosphate esters. Phosphate accounted for 19 ± 2% of the total phosphorus compounds observed in CZ maintained under low P-levels (0.02 μM). Adding 5 mM of dissolved inorganic phosphorus (KH2PO4) to the CZ culture medium led to a 3.1-fold increase in intracellular phosphate, while adding 5 mM of dissolved organic phosphorus led to a reduction in the concentration of phosphorus compounds, including a 2.5-fold intracellular phosphate decrease. In sharp contrast to zooxanthellae, the host mainly contained phosphonates, and to a lesser extent, phosphate esters and phosphate. Two-months of host starvation decreased the phosphate content by 2.4 fold, while bleaching of fed corals did not modify this content. Based on 31P NMR analyses, this study highlights the importance of phosphonates in the composition of coral host tissues, and illustrates the impact of phosphorus availability on the phosphorus composition of host tissues and CZ, both through feeding of the host and inorganic phosphorus enrichment of the CZ.

  2. Rate equation for creatine kinase predicts the in vivo reaction velocity: /sup 31/P NMR surface coil studies in brain, heart, and skeletal muscle of the living rat

    SciTech Connect

    Bittl, J.A.; DeLayre, J.; Ingwall, J.S.

    1987-09-22

    Brain, heart, and skeletal muscle contain four different creatine kinase isozymes and various concentrations of substrates for the creatine kinase reaction. To identify if the velocity of the creatine kinase reaction under cellular conditions is regulated by enzyme activity and substrate concentrations as predicted by the rate equation, the authors used /sup 31/P NMR and spectrophotometric techniques to measure reaction velocity, enzyme content, isozyme distribution, and concentrations of substrates in brain, heart, and skeletal muscle of living rat under basal or resting conditions. The total tissue activity of creatine kinase in the direction of MgATP synthesis provided an estimate for V/sub max/ and exceeded the NMR-determined in vivo reaction velocities by an order of magnitude. The isozyme composition varied among the three tissues: >99% BB for brain; 14% MB, 61% MM, and 25% mitochondrial for heart; and 98% MM and 2% mitochondrial for skeletal muscle. The NMR-determined reaction velocities agreed with predicted values from the creatine kinase rate equation. The concentrations of free creatine and cytosolic MgADP, being less than or equal to the dissociation constants for each isozyme, were dominant terms in the creatine kinase rate equation for predicting the in vivo reaction velocity. Thus, they observed that the velocity of the creatine kinase reaction is regulated by total tissue enzyme activity and by the concentrations of creatine and MgADP in a manner that is independent of isozyme distribution.

  3. On the use of 31P NMR for the quantification of hydrosoluble phosphorus-containing compounds in coral host tissues and cultured zooxanthellae.

    PubMed

    Godinot, Claire; Gaysinski, Marc; Thomas, Olivier P; Ferrier-Pagès, Christine; Grover, Renaud

    2016-02-23

    (31)P Nuclear Magnetic Resonance (NMR) was assessed to investigate the phosphorus-containing compounds present in the tissues of the scleractinian coral Stylophora pistillata as well as of cultured zooxanthellae (CZ). Results showed that phosphorus-containing compounds observed in CZ were mainly phosphate and phosphate esters. Phosphate accounted for 19 ± 2% of the total phosphorus compounds observed in CZ maintained under low P-levels (0.02 μM). Adding 5 mM of dissolved inorganic phosphorus (KH2PO4) to the CZ culture medium led to a 3.1-fold increase in intracellular phosphate, while adding 5 mM of dissolved organic phosphorus led to a reduction in the concentration of phosphorus compounds, including a 2.5-fold intracellular phosphate decrease. In sharp contrast to zooxanthellae, the host mainly contained phosphonates, and to a lesser extent, phosphate esters and phosphate. Two-months of host starvation decreased the phosphate content by 2.4 fold, while bleaching of fed corals did not modify this content. Based on (31)P NMR analyses, this study highlights the importance of phosphonates in the composition of coral host tissues, and illustrates the impact of phosphorus availability on the phosphorus composition of host tissues and CZ, both through feeding of the host and inorganic phosphorus enrichment of the CZ.

  4. The effect of ethanol on hydroxyl and carbonyl groups in biopolyol produced by hydrothermal liquefaction of loblolly pine: (31)P-NMR and (19)F-NMR analysis.

    PubMed

    Celikbag, Yusuf; Via, Brian K; Adhikari, Sushil; Buschle-Diller, Gisela; Auad, Maria L

    2016-08-01

    The goal of this study was to investigate the role of ethanol and temperature on the hydroxyl and carbonyl groups in biopolyol produced from hydrothermal liquefaction of loblolly pine (Pinus spp.) carried out at 250, 300, 350 and 390°C for 30min. Water and water/ethanol mixture (1/1, wt/wt) were used as liquefying solvent in the HTL experiments. HTL in water and water/ethanol is donated as W-HTL and W/E-HTL, respectively. It was found that 300°C and water/ethanol solvent was the optimum liquefaction temperature and solvent, yielding up to 68.1wt.% bio-oil and 2.4wt.% solid residue. (31)P-NMR analysis showed that biopolyol produced by W-HTL was rich in phenolic OH while W/E-HTL produced more aliphatic OH rich biopolyols. Moreover, biopolyols with higher hydroxyl concentration were produced by W/E-HTL. Carbonyl groups were analyzed by (19)F-NMR, which showed that ethanol reduced the concentration of carbonyl groups.

  5. On the use of 31P NMR for the quantification of hydrosoluble phosphorus-containing compounds in coral host tissues and cultured zooxanthellae

    PubMed Central

    Godinot, Claire; Gaysinski, Marc; Thomas, Olivier P.; Ferrier-Pagès, Christine; Grover, Renaud

    2016-01-01

    31P Nuclear Magnetic Resonance (NMR) was assessed to investigate the phosphorus-containing compounds present in the tissues of the scleractinian coral Stylophora pistillata as well as of cultured zooxanthellae (CZ). Results showed that phosphorus-containing compounds observed in CZ were mainly phosphate and phosphate esters. Phosphate accounted for 19 ± 2% of the total phosphorus compounds observed in CZ maintained under low P-levels (0.02 μM). Adding 5 mM of dissolved inorganic phosphorus (KH2PO4) to the CZ culture medium led to a 3.1-fold increase in intracellular phosphate, while adding 5 mM of dissolved organic phosphorus led to a reduction in the concentration of phosphorus compounds, including a 2.5-fold intracellular phosphate decrease. In sharp contrast to zooxanthellae, the host mainly contained phosphonates, and to a lesser extent, phosphate esters and phosphate. Two-months of host starvation decreased the phosphate content by 2.4 fold, while bleaching of fed corals did not modify this content. Based on 31P NMR analyses, this study highlights the importance of phosphonates in the composition of coral host tissues, and illustrates the impact of phosphorus availability on the phosphorus composition of host tissues and CZ, both through feeding of the host and inorganic phosphorus enrichment of the CZ. PMID:26902733

  6. {sup 31}P NMR study of the complexation of TBP with lanthanides and actinides in solution and in a clay matrix

    SciTech Connect

    Hartzell, C.J.

    1994-07-24

    Goal was to use NMR to study TBP/lanthanide complexes in the interlayer or on edge sites of clays. Work in this laboratory yielded details of the complexation of Eu(NO{sub 3}){sub 3} and Pr(NO{sub 3}){sub 3} with TBP in hexane solution; this information is crucial to interpretation of results of NMR studies of the complexes exchanged into clays. The solution {sup 31}P-chemical shift values were improved by repeating the studies on the lanthanide salts dissolved directly into neat TBP. NMR studies of these neat solutions of the Eu(NO{sub 3}){sub 3}{lg_bullet}3TBP-complex and the Pr(NO{sub 3}){sub 3}{lg_bullet}3TBP-complex show that the {sup 31}P chemical shift remains relatively constant for TBP: lanthanide ratios below 3: 1. At higher ratios, the chemical shift approaches that of free TBP, indicating rapid exchange of TBP between the free and complexed state. Exchange of these complexes into the clay hectorite yielded discrete {sup 31}P-NMR signals for the Eu{lg_bullet}TBP complex at -190 ppm and free TBP at -6 ppm. Adsorption of the Pr{lg_bullet}TBP complex yielded broad signals at 76 ppm for the complex and -6 ppm for free TBP. There was no evidence of exchange between the incorporated complex and the free TBP.

  7. Hyposmotic shock: effects on rubidium/potassium efflux in normal and ischemic rat hearts, assessed by 87Rb and 31P NMR.

    PubMed

    Jilkina, Olga; Kuzio, Bozena; Kupriyanov, Valery V

    2003-01-20

    The study evaluated effects of hyposmotic shock on the rate of Rb(+)/K(+) efflux, intracellular pH and energetics in Langendorff-perfused rat hearts with the help of 87Rb- and 31P-NMR. Two models of hyposmotic shock were compared: (1) normosmotic hearts perfused with low [NaCl] (70 mM) buffer, (2) hyperosmotic hearts equilibrated with additional methyl alpha-D-glucopyranoside (Me-GPD, 90 or 33 mM) or urea (90 mM) perfused with normosmotic buffer. Four minutes after hyposmotic shock, Rb(+) efflux rate constant transiently increased approximately two-fold, while pH transiently decreased by 0.08 and 0.06 units, in the first and the second models, respectively, without significant changes in phosphocreatine and ATP. Hyposmotic shock (second model) did not change the rate of Rb(+)/K(+) uptake, indicating that the activity of Na(+)/K(+) ATPase was not affected. Dimethylamiloride (DMA) (10 microM) abolished activation of the Rb(+)/K(+) efflux in the second model; however, Na(+)/H(+) exchanger was not involved, because intracellular acidosis induced by the hyposmotic shock was not enhanced by DMA treatment. After 12 or 20 min of global ischemia, the rate of Rb(+)/K(+) efflux increased by 120%. Inhibitor of the ATP-sensitive potassium channels, glibenclamide (5 microM), partially (40%) decreased the rate constant; however, reperfusion with hyperosmolar buffer (90 mM Me-GPD) did not. We concluded that the shock-induced stimulation of Rb(+)/K(+) efflux occurred, at least partially, through the DMA-sensitive cation/H(+) exchanger and swelling-induced mechanisms did not considerably contribute to the ischemia-reperfusion-induced activation of Rb(+)/K(+) efflux.

  8. Structural and {sup 31}P NMR investigation of Bi(MM'){sub 2}PO{sub 6} statistic solid solutions: Deconvolution of lattice constraints and cationic influences

    SciTech Connect

    Colmont, Marie; Delevoye, Laurent; Ketatni, El Mostafa; Montagne, Lionel; Mentre, Olivier . E-mail: mentre@ensc-lille.fr

    2006-07-15

    Two solid solutions BiM{sub x} Mg{sub (2-x)}PO{sub 6} (with M {sup 2+}=Zn or Cd) have been studied through {sup 31}P MAS NMR. The analysis has been performed on the basis of refined crystal structures through X-ray diffraction and neutron diffraction. The BiZn {sub x} Mg{sub (2-x)}PO{sub 6} does not provide direct evidence for sensitive changes in the phosphorus local symmetry. This result is in good agreement with structural data which show nearly unchanged lattices and atomic separations through the Zn{sup 2+} for Mg{sup 2+} substitution. On the other hand, the Cd{sup 2+} for Mg{sup 2+} substitution behaves differently. Indeed, up to five resonances are observed, each corresponding to one of the five first-cationic neighbour distributions, i.e. 4Mg/0Cd, 3Mg/1Cd, 2Mg/2Cd, 1Mg/3Cd and 0Mg/4Cd. Their intensities match rather well the expected weight for each configuration of the statistical Cd{sup 2+}/Mg{sup 2+} mixed occupancy. The match is further improved when one takes into account the influence of the 2nd cationic sphere that is available from high-field NMR data (18.8 T). Finally, the fine examination of the chemical shift for each resonance versus x allows to de-convolute the mean Z/a {sup 2} effective field into two sub-effects: a lattice constraint-only term and a chemical-only term whose effects are directly quantifiable. - Graphical abstract: First (CdMg){sub 4} cationic sphere influence on the {sup 31}P NMR signal in Bi(Cd,Mg){sub 2}PO{sub 6}. Display Omitted.

  9. 31P NMR spectroscopy in the quality control and authentication of extra-virgin olive oil: a review of recent progress.

    PubMed

    Dais, Photis; Spyros, Apostolos

    2007-05-01

    This review is a brief account on the application of a novel methodology to the quality control and authentication of extra-virgin olive oil. This methodology is based on the derivatization of the labile hydrogens of functional groups, such as hydroxyl and carboxyl groups, of olive oil constituents with the phosphorus reagent 2-chloro-4,4,5,5-tetramethyldioxaphospholane, and the use of the (31)P chemical shifts to identify the phosphitylated compounds. Various experimental aspects such as pertinent instrumentation, sample preparation, acquisition parameters and properties of the phosphorus reagent are reviewed. The strategy to assign the (31)P signals of the phosphitylated model compounds and olive oil constituents by employing 1D and 2D NMR experiments is presented. Finally, the capability of this technique to assess the quality and the genuineness of extra-virgin olive oil and to detect fraud is discussed.

  10. Characteristics and degradation of carbon and phosphorus from aquatic macrophytes in lakes: insights from solid-state 13C NMR and solution 31P NMR spectroscopy

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Water extractable organic matter (WEOM) derived from macrophytes plays an important role in biogeochemical cycling of nutrients, including carbon (C), nitrogen (N) and phosphorus (P) in lakes. However, reports of their composition and degradation in natural waters are scarce. Therefore, compositions...

  11. Characteristics and assessment of biogenic phosphorus in sediments from the multi-polluted Haihe River, China, using phosphorus fractionation and phosphorus-31 nuclear magnetic resonance (31P-NMR)

    NASA Astrophysics Data System (ADS)

    Zhang, W. Q.; Zhang, H.; Tang, W. Z.; Shan, B. Q.

    2013-10-01

    We studied the phosphorus (P) pollution, as described by concentrations, distribution and transformation potential, of sediments of the water scarce and heavily polluted Fuyang River, a tributary of the Haihe River, using P fractionation and phosphorus-31 nuclear magnetic resonance (31P-NMR).The sediments of the Fuyang River accumulate significant amounts of inorganic phosphorus (Pi) and organic phosphorus (Po) from industrial and domestic wastewater and agricultural non-point pollution. In terms of their contribution to total phosphorus, the rank order of the P fractions was as follows: H2SO4-P > NaOH-Pi > Res-P > NaOH-Po > KCl-P and their average relative proportions were 69.7:47.5:15.9:2.9:1.0 (the proportion was based on the average proportion of the KCl-P). Seven P compounds were detected by the 31P-NMR analysis. Orthophosphate (Ortho-P: 45.2-92.4%) and orthophosphate monoesters (mono-P: 6.6-45.7%) were the dominant forms. Smaller amounts of pyrophosphates (pyro-P: 0.1-6.6%), deoxyribonucleic acid (DNA-P: 0.3-3.9%), phosphonates (phon-P: 0-3.3%), phospholipids (lipids-P: 0-2.7%) and polyphosphate (poly-P: 0-0.04%) were observed in the sediments. Results of P fractionation and 31P-NMR analysis showed that 35% of Pi was labile P, including KCl-P and NaOH-Pi (Fe-P and Al-P). Biogenic-P accounted for 24% of P in the sediments. Analysis of the relationships between P species and water quality indicated that the Po compounds would mineralize to form ortho-P and would be potentially bioavailable for recycling to surface water, supporting further growth of phytoplankton and leading to algal blooms.

  12. Determination of the enantiomeric excess of chiral carboxylic acids by 31P NMR with phosphorylated derivatizing agents from C2-symmetrical diamines containing the (S)-alpha-phenylethyl group.

    PubMed

    Mastranzo, Virginia M; Quintero, Leticia; de Parrodi, Cecilia Anaya

    2007-06-01

    The use of P(III) and P(V) organophosphorus derivatizing agents prepared from C(2) symmetrical (1R,2R)- and (1S,2S)-trans-N,N'-bis-[(S)-alpha-phenylethyl]-cyclohexane-1,2-diamines 1 and 2, as well as (1R,2R)- and (1S,2S)-trans-N,N'-bis-[(S)-alpha-phenylethyl]-4-cyclohexene-1,2-diamines 3 and 4 for the determination of enantiomeric composition of chiral carboxylic acids by (31)P NMR, is described.

  13. Phospholipid compositions of sera and synovial fluids from dog, human and horse: a comparison by 31P-NMR and MALDI-TOF MS.

    PubMed

    Fuchs, B; Bondzio, A; Wagner, U; Schiller, J

    2009-08-01

    Alterations of the phospholipid (PL) compositions of body fluids are assumed to be indicative of inflammatory diseases, e.g. rheumatoid arthritis (RA). Recently, we have shown that particularly the phosphatidylcholine/lysophosphatidylcholine (PC/LPC) ratio determined in human synovial fluids (SF) and sera represents a reliable measure of the inflammatory state in RA patients. However, it is not yet clear to what extent the PC/LPC ratio is also affected by nutrition habits. In the present study, the PL and the corresponding acyl chain compositions of human body fluids (SF and serum of RA patients as well as serum from healthy volunteers) are compared with those of two other mammalian species (horses and dogs suffering from degenerative joint diseases as well as healthy controls) by high-resolution 31P-nuclear magnetic resonance (NMR) spectroscopy and matrix-assisted laser desorption and ionization time-of-flight mass spectrometry (MALDI-TOF MS). The most important result of this study is that the PL compositions of SF and serum of horse and dog are comparable with those of human body fluids. Compared with humans, however, the horse body fluid contains less PCs with highly unsaturated arachidonoyl residues, while that of dogs possesses the highest content of arachidonoyl-containing PC. These species-related differences stem primarily from different nutrition habits (meat vs. plants).

  14. In vivo sup 23 Na and sup 31 P NMR measurement of a tonoplast Na sup + /H sup + exchange process and its characteristics in two barley cultivars

    SciTech Connect

    Fan, T.W.M.; Norlyn, J.; Epstein, E. ); Higashi, R.M. )

    1989-12-01

    A Na{sup +} uptake-associated vacuolar alkalinization was observed in roots of two barley cultivars (Arivat and the more salt-tolerant California Mariout) by using {sup 23}Na and {sup 31}P in vivo NMR spectroscopy. A NaCl uptake-associated broadening was also noted for both vacuolar P{sub i} and intracellular Na NMR peaks, consistent with Na{sup +} uptake into the same compartment as the vacuolar P{sub i}. A close coupling of Na{sup +} with H{sup +} transport (presumably the Na{sup +}/H{sup +} antiport) in vivo was evidence by qualitative and quantitative correlations between Na{sup +} accumulation and vacuolar alkalinization for both cultivars. Prolongation of the low NaCl pretreatment (30 mM) increased the activity of the putative antiport in Arivat but reduced it in California Mariout. This putative antiport also showed a dependence on NaCl concentration for California Mariout but not for Arivat. No cytoplasmic acidification accompanied the antiporter activity for either cultivar. The response of adenosine phosphates indicated that ATP utilization exceeded the capacity for ATP synthesis in Arivat, but the two processes seemed balanced in California Mariout. These comparisons provide clues to the role of the tonoplast Na{sup +}/H{sup +} antiport and compensatory cytoplasmic adjustments including pH, osymolytes, and energy phosphates in governing the different salt tolerance of the two cultivars.

  15. 31P NMR 2D Mapping of Creatine Kinase Forward Flux Rate in Hearts with Postinfarction Left Ventricular Remodeling in Response to Cell Therapy

    PubMed Central

    Gao, Ling; Cui, Weina; Zhang, Pengyuan; Jang, Albert; Zhu, Wuqiang; Zhang, Jianyi

    2016-01-01

    Utilizing a fast 31P magnetic resonance spectroscopy (MRS) 2-dimensional chemical shift imaging (2D-CSI) method, this study examined the heterogeneity of creatine kinase (CK) forward flux rate of hearts with postinfarction left ventricular (LV) remodeling. Immunosuppressed Yorkshire pigs were assigned to 4 groups: 1) A sham-operated normal group (SHAM, n = 6); 2) A 60 minutes distal left anterior descending coronary artery ligation and reperfusion (MI, n = 6); 3) Open patch group; ligation injury plus open fibrin patch over the site of injury (Patch, n = 6); and 4) Cell group, hiPSCs-cardiomyocytes, -endothelial cells, and -smooth muscle cells (2 million, each) were injected into the injured myocardium pass through a fibrin patch (Cell+Patch, n = 5). At 4 weeks, the creatine phosphate (PCr)/ATP ratio, CK forward flux rate (Flux PCr→ATP), and k constant of CK forward flux rate (kPCr→ATP) were severely decreased at border zone myocardium (BZ) adjacent to MI. Cell treatment results in significantly increase of PCr/ATP ratio and improve the value of kPCr→ATP and Flux PCr→ATP in BZ myocardium. Moreover, the BZ myocardial CK total activity and protein expression of CK mitochondria isozyme and CK myocardial isozyme were significantly reduced, but recovered in response to cell treatment. Thus, cell therapy results in improvement of BZ bioenergetic abnormality in hearts with postinfarction LV remodeling, which is accompanied by significantly improvements in BZ CK activity and CK isozyme expression. The fast 2D 31P MR CSI mapping can reliably measure the heterogeneity of bioenergetics in hearts with post infarction LV remodeling. PMID:27606901

  16. Assessing crop residue phosphorus speciation using chemical fractionation and solution 31P nuclear magnetic resonance spectroscopy.

    PubMed

    Noack, Sarah R; Smernik, Ronald J; McBeath, Therese M; Armstrong, Roger D; McLaughlin, Mike J

    2014-08-01

    At physiological maturity, nutrients in crop residues can be released to the soil where they are incorporated into different labile and non-labile pools while the remainder is retained within the residue itself. The chemical speciation of phosphorus (P) in crop residues is an important determinant of the fate of this P. In this study, we used chemical fractionation and (31)P nuclear magnetic resonance (NMR) spectroscopy, first separately and then together, to evaluate the P speciation of mature oat (Avena sativa) residue. Two water extracts (one employing shaking and the other sonication) and two acid extracts (0.2N perchloric acid and 10% trichloroacetic acid) of these residues contained similar concentrations of orthophosphate (molybdate-reactive P determined by colorimetry) as NaOH-EDTA extracts of whole plant material subsequently analysed by solution (31)P NMR spectroscopy. However, solution (31)P NMR analysis of the extracts and residues isolated during the water/acid extractions indicated that this similarity resulted from a fortuitous coincidence as the orthophosphate concentration in the water/acid extracts was increased by the hydrolysis of pyrophosphate and organic P forms while at the same time there was incomplete extraction of orthophosphate. Confirmation of this was the absence of pyrophosphate in both water and acid fractions (it was detected in the whole plant material) and the finding that speciation of organic P in the fractions differed from that in the whole plant material. Evidence for incomplete extraction of orthophosphate was the finding that most of the residual P in the crop residues following water/acid extractions was detected as orthophosphate using (31)P NMR. Two methods for isolating and quantifying phospholipid P were also tested, based on solubility in ethanol:ether and ethanol:ether:chloroform. While these methods were selective and appeared to extract only phospholipid P, they did not extract all phospholipid P, as some was

  17. 31P-NMR analysis of the B to Z transition in double-stranded (dC-dG)3 and (dC-dG)4 in high salt solution.

    PubMed Central

    Holak, T A; Borer, P N; Levy, G C; van Boom, J H; Wang, A H

    1984-01-01

    In 4M NaCl solutions (dC-dG)n (n = 3,4; approximately 9 mM) exist as a mixture o +/- B and Z forms. The low and high field components of two 31P NMR resonances originating from internal phosphodiester groups are assigned to the GpC and CpG linkages, respectively. Low temperatures stabilize the Z-forms, which completely disappear above 50 degrees C (n = 3) and 65 degrees C (n = 4). delta H = -44 and -17 kJ/mol for B to Z transition in the hexamer and octamer duplexes, respectively. Temperature dependent changes (0-50 degrees C range) in the spin-lattice relaxation times at 145.7 MHz are distinctly different for the 31P nuclei o +/- GpC and CpG groups. The relaxation data can be explained by assuming that the GpC phosphodiester groups undergo more local internal motion than do the CpG groups. PMID:6547530

  18. In situ preparation and fate of cis-4-hydroxycyclophosphamide and aldophosphamide: 1H and 31P NMR evidence for equilibration of cis- and trans-4-hydroxycyclophosphamide with aldophosphamide and its hydrate in aqueous solution.

    PubMed

    Borch, R F; Hoye, T R; Swanson, T A

    1984-04-01

    cis-4-Hydroxycyclophosphamide (2) and aldophosphamide (4) were generated in aqueous phosphate or cacodylate buffer by dimethyl sulfide reduction of cis-4-hydroperoxycyclophosphamide (8) and by sodium periodate cleavage of 3,4-dihydroxybutyl N,N-bis(2-chloroethyl)phosphorodiamidate (9), respectively; the reactions of 2 and 4 were examined by 1H and 31P NMR. Within 30-60 min (pH or pD 7.0, 25 degrees C) the same pseudoequilibrium mixture was established in both reactions, with cis- and trans-4-hydroxycyclophosphamide (2 and 3), aldophosphamide (4), and its hydrate (5) present in the approximate ratio of 4:2:0.3:1. Structures of the intermediates were assigned unambiguously based upon analysis of the chemical shifts and coupling constants in the proton spectra determined in D2O buffers, and the 31P assignments followed by correlation of component ratios at equilibrium. Free energy differences of 0.4, 0.4, and 0.7 kcal/mol at 25 degrees C were estimated between 2, 3, 5, and 4, respectively, with 2 being the most stable. The aldehyde 4 reacted most rapidly with water to give hydrate 5; cyclization of 4 to 3 occurred faster than to 2, and the rate of cyclization to 2 was comparable to that for elimination to 6. Compound 5 is formed much faster than 3 from the diol cleavage, but 5 and 3 are produced at comparable rates from 2, suggesting that conversion of 2 to 3 can proceed by a mechanism other than ring opening. The rate of equilibration appears to be independent of buffer structure, indicating that bifunctional catalysis is not important in the ring-opening reaction.(ABSTRACT TRUNCATED AT 250 WORDS)

  19. Simultaneous Conoscopic Holography and Raman Spectroscopy

    NASA Technical Reports Server (NTRS)

    Schramm, Harry F.; Kaiser, Bruce

    2005-01-01

    A new instrument was developed for chemical characterization of surfaces that combines the analytical power of Raman spectroscopy with the three-dimensional topographic information provided by conoscopic holography. The figure schematically depicts the proposed hybrid instrument. The output of the conoscopic holographic portion of the instrument is a topographical map of the surface; the output of the Raman portion of the instrument is hyperspectral Raman data, from which the chemical and/or biological composition of the surface would be deduced. By virtue of the basic principles of design and operation of the instrument, the hyperspectral image data would be inherently spatially registered with the topographical data. In conoscopic holography, the object and reference beams of classical holography are replaced by the ordinary and extraordinary components generated by a single beam traveling through a birefringent, uniaxial crystal. In the basic conoscopic configuration, a laser light is projected onto a specimen and the resulting illuminated spot becomes a point source of diffuse light that propagates in every direction. The laser beam is rasterscanned in two dimensions (x and y) perpendicular to the beam axis (z), and at each x,y location, the pattern of interference between the ordinary and extraordinary rays is recorded. The recorded interferogram constitutes the conoscopic hologram. Of particular significance for the proposed instrument is that the conoscopic hologram contains information on the z coordinate (height) of the illuminated surface spot. Hence, a topographical map of the specimen is constructed point-by-point by rastering the laser beam in the x and y directions and correlating the x and y coordinates with the z information obtained from the interferograms. Conoscopic imaging is an established method, and conoscopic laboratory instruments for surface metrology are commercially available. In Raman spectroscopy of a surface, one measures the spectrum

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

    SciTech Connect

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

    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.

  1. Simultaneous Surface-Near and Solution Fluorescence Correlation Spectroscopy.

    PubMed

    Winterflood, Christian M; Seeger, Stefan

    2016-05-01

    We report the first simultaneous measurement of surface-confined and solution fluorescence correlation spectroscopy (FCS). We use an optical configuration for tightly focused excitation and separate detection of light emitted below (undercritical angle fluorescence, UAF) and above (supercritical angle fluorescence, SAF) the critical angle of total internal reflection of the coverslip/sample interface. This creates two laterally coincident detection volumes which differ in their axial extent. While detection of far-field UAF emission producesa standard confocal volume, near-field-mediated SAF produces a highly surface-confined detection volume at the coverslip/sample interface which extends only ~200 nm into the sample. A characterization of the two detection volumes by FCS of free diffusion is presented and compared with analytical models and simulations. The presented FCS technique allows to determine bulk solution concentrations and surface-near concentrations at the same time.

  2. Posttranslational modification of Klebsiella pneumoniae flavodoxin by covalent attachment of coenzyme A, shown by sup 31 P NMR and electrospray mass spectrometry, prevents electron transfer from the nifJ protein to nitrogenase. A possible new regulatory mechanism for biological nitrogen fixation

    SciTech Connect

    Thorneley, R.N.F.; Ashby, G.A.; Drummond, M.H.; Eady, R.R.; Huff, S.; Macdonald, C.J. ); Abell, C.; Schneier, A. )

    1992-02-04

    A strain of Escherichia coli (71-18) that produces ca. 15% of its soluble cytoplasmic protein as a flavodoxin, the Klebsiella pneumoniae nifF gene product, has been constructed. The flavodoxin was purified using FPLC and resolved into two forms, designated KpFldI and KpFldII, which were shown to have identical N-terminal amino acid sequences (30 residues) in agreement with that predicted by the K. pneumoniae nifF DNA sequence. {sup 31}P NMR, electrospray mass spectrometry, UV-visible spectra, and thiol group estimations showed that the single cysteine residue (position 68) of KpFldI is posttranslationally modified in KpFldII by the covalent, mixed disulfide, attachment of coenzyme A. KpFldII was inactive as an electron carrier between the K. pneumoniae nifJ product (a pyruvate-flavodoxin oxidoreductase) and K. pneumoniae nifH product (the Fe-protein of nitrogenase). This novel posttranslational modification of a flavodoxin is discussed in terms of the regulation of nitrogenase activity in vivo in response to the level of dissolved O{sub 2} and the carbon status of diazotrophic cultures.

  3. Simultaneous denitrification and phosphorus removal by Agrobacterium sp. LAD9 under varying oxygen concentration.

    PubMed

    Ma, Tao; Chen, Qian; Gui, Mengyao; Li, Can; Ni, Jinren

    2016-04-01

    Although efficient aerobic denitrification has received increasing attention, few studies have been made on simultaneous denitrification and phosphorus removal (SDPR) under aerobic condition. In this study, SDPR by an efficient aerobic denitrifier, Agrobacterium sp. LAD9, was firstly demonstrated. High nitrate and phosphorus removal rates of 7.50 and 1.02 mg L(-1) h(-1) were achieved in wide range of O2 concentration from 5.92 to 20.02 mg L(-1). The N2O production would be inhibited as O2 concentration exceeded 11.06 mg L(-1), while the phosphorus removal efficiency would be generally improved with increasing O2 concentration. (15)N mass spectrometry revealed that nitrogen removal accorded with the typical aerobic denitrification pathway, while (31)P nuclear magnetic resonance spectroscopy ((31)P NMR) indicated the fate of phosphorus to cells, extracellular polymeric substances (EPS), and polyphosphate (poly-P) of the denitrifier. EPS acted as a reservoir of phosphorus and the transformation of poly-P was dynamic and depended on initial orthophosphate (ortho-P) content. The aerobic SDPR would greatly simplify the conventional wastewater treatment processes which required separated considerations of nitrogen and phosphorus removal.

  4. Simultaneous multi-beam planar array IR (pair) spectroscopy

    DOEpatents

    Elmore, Douglas L.; Rabolt, John F.; Tsao, Mei-Wei

    2005-09-13

    An apparatus and method capable of providing spatially multiplexed IR spectral information simultaneously in real-time for multiple samples or multiple spatial areas of one sample using IR absorption phenomena requires no moving parts or Fourier Transform during operation, and self-compensates for background spectra and degradation of component performance over time. IR spectral information and chemical analysis of the samples is determined by using one or more IR sources, sampling accessories for positioning the samples, optically dispersive elements, a focal plane array (FPA) arranged to detect the dispersed light beams, and a processor and display to control the FPA, and display an IR spectrograph. Fiber-optic coupling can be used to allow remote sensing. Portability, reliability, and ruggedness is enhanced due to the no-moving part construction. Applications include determining time-resolved orientation and characteristics of materials, including polymer monolayers. Orthogonal polarizers may be used to determine certain material characteristics.

  5. Combined coherent anti-Stokes Raman spectroscopy and linear Raman spectroscopy for simultaneous temperature and multiple species measurements.

    PubMed

    Weikl, Markus C; Beyrau, Frank; Kiefer, Johannes; Seeger, Thomas; Leipertz, Alfred

    2006-06-15

    The simultaneous application of pure rotational coherent anti-Stokes Raman spectroscopy (CARS) and vibrational linear Raman spectroscopy (LRS) for the measurement of temperature and species concentrations in combustion systems is demonstrated. In addition to the standard rotational CARS experimental setup, only one detection system (spectrometer and intensified CCD camera) for the collection of the LRS signals was applied. The emission of the broadband dye laser used for CARS was shifted to the deep red to avoid interferences with the LRS signals located in the visible region. First experimental results from a vaporizing propane spray using an engine injection system are shown.

  6. Simultaneous rotational coherent anti-Stokes Raman spectroscopy and coherent Stokes Raman spectroscopy with arbitrary pump-Stokes spectral separation.

    PubMed

    Eckbreth, A C; Anderson, T J

    1986-08-01

    A new approach to pure rotational coherent anti-Stokes Raman spectroscopy (CARS) and coherent Stokes Raman spectroscopy (CSRS) is demonstrated in which the pump and broadband Stokes lasers that are mixed have a large and arbitrary spectral separation. In this method, the rotational Raman coherences are established by different frequency components within the single, broadband Stokes source. The narrow band then scatters from the excited coherences, producing CARS and CSRS simultaneously. We discuss phase matching for this new technique and its inherent advantages relative to pure rotational CARS as normally implemented.

  7. Characterizing mixed phosphonic acid ligand capping on CdSe/ZnS quantum dots using ligand exchange and NMR spectroscopy.

    PubMed

    Davidowski, Stephen K; Lisowski, Carmen E; Yarger, Jeffery L

    2016-03-01

    The ligand capping of phosphonic acid functionalized CdSe/ZnS core-shell quantum dots (QDs) was investigated with a combination of solution and solid-state (31) P nuclear magnetic resonance (NMR) spectroscopy. Two phosphonic acid ligands were used in the synthesis of the QDs, tetradecylphosphonic acid and ethylphosphonic acid. Both alkyl phosphonic acids showed broad liquid and solid-state (31) P NMR resonances for the bound ligands, indicative of heterogeneous binding to the QD surface. In order to quantify the two ligand populations on the surface, ligand exchange facilitated by phenylphosphonic acid resulted in the displacement of the ethylphosphonic acid and tetradecylphosphonic acid and allowed for quantification of the free ligands using (31) P liquid-state NMR. After washing away the free ligand, two broad resonances were observed in the liquids' (31) P NMR corresponding to the alkyl and aromatic phosphonic acids. The washed samples were analyzed via solid-state (31) P NMR, which confirmed the ligand populations on the surface following the ligand exchange process. Copyright © 2015 John Wiley & Sons, Ltd.

  8. Detergent-like properties of magainin antibiotic peptides: a 31P solid-state NMR spectroscopy study.

    PubMed

    Bechinger, Burkhard

    2005-06-15

    (31)P solid-state NMR spectroscopy has been used to investigate the macroscopic phase behavior of phospholipid bilayers in the presence of increasing amounts of magainin antibiotic peptides. Addition of >1 mol% magainin 2 to gel-phase DMPC or liquid crystalline POPC membranes respectively, results in (31)P NMR spectra that are characterized by the coexistence of isotropic signals and line shapes typical for phospholipid bilayers. The isotropic signal intensity is a function of temperature and peptide concentration. At peptide concentrations >4 mol% of the resulting phospholipid (31)P NMR spectra are characteristic of magnetically oriented POPC bilayers suggesting the formation of small disk-like micelles or perforated sheets. In contrast, addition of magainin to acidic phospholipids results in homogenous bilayer-type (31)P NMR spectra with reduced chemical shift anisotropies. The results presented are in good agreement with the interfacial insertion of magainin helices with an alignment parallel to the surface of the phospholipid bilayers. The resulting curvature strain results in detergent-like properties of the amphipathic helical peptides.

  9. Fluorine-19 or phosphorus-31 NMR spectroscopy: a suitable analytical technique for quantitative in vitro metabolic studies of fluorinated or phosphorylated drugs.

    PubMed

    Martino, Robert; Gilard, Véronique; Desmoulin, Franck; Malet-Martino, Myriam

    2005-08-10

    Fluorine-19 or phosphorus-31 NMR (19F NMR or 31P NMR) spectroscopy provides a highly specific tool for identification of fluorine- or phosphorus-containing drugs and their metabolites in biological media as well as a suitable analytical technique for their absolute quantification. This article focuses on the application of in vitro 19F or 31P NMR to the quantitative metabolic studies of some fluoropyrimidine or oxazaphosphorine drugs in clinical use. The first part presents an overview of the advantages (non-destructive and non-selective direct quantitative study of the biological matrices) and limitations (expensive cost of the spectrometers, limited mass or concentration sensitivity) of NMR spectroscopy. The second part deals with the criteria to be considered for successful quantification by NMR (uniform excitation over the entire spectral width of the spectrum, resonance signals properly characterised by taking into account T1 values and avoiding NOE enhancements, optimisation of the data processing, choice of a suitable standard reference). The third and fourth parts report some examples of quantification of 5-fluorouracil, its prodrug capecitabine, 5-fluorocytosine and their metabolites in bulk solutions (biofluids, tissue extracts, perfusates and culture media) and heterogeneous media (excised tissues and packed intact cells) as well as cyclophosphamide and ifosfamide in biofluids. These two parts emphasise the high potential of in vitro 19F or 31P NMR for absolute quantification, in a single run, of all the fluorine- or phosphorus-containing species in the matrices analysed. The limit of quantification in bulk solutions is 1-3 microM for 19F NMR and approximately 10 microM for 31P NMR. In heterogeneous media analysed with 19F NMR, it is 2-5 nmol in excised tissues and cell pellets.

  10. Simultaneous femtosecond X-ray spectroscopy and diffraction of photosystem II at room temperature.

    PubMed

    Kern, Jan; Alonso-Mori, Roberto; Tran, Rosalie; Hattne, Johan; Gildea, Richard J; Echols, Nathaniel; Glöckner, Carina; Hellmich, Julia; Laksmono, Hartawan; Sierra, Raymond G; Lassalle-Kaiser, Benedikt; Koroidov, Sergey; Lampe, Alyssa; Han, Guangye; Gul, Sheraz; Difiore, Dörte; Milathianaki, Despina; Fry, Alan R; Miahnahri, Alan; Schafer, Donald W; Messerschmidt, Marc; Seibert, M Marvin; Koglin, Jason E; Sokaras, Dimosthenis; Weng, Tsu-Chien; Sellberg, Jonas; Latimer, Matthew J; Grosse-Kunstleve, Ralf W; Zwart, Petrus H; White, William E; Glatzel, Pieter; Adams, Paul D; Bogan, Michael J; Williams, Garth J; Boutet, Sébastien; Messinger, Johannes; Zouni, Athina; Sauter, Nicholas K; Yachandra, Vittal K; Bergmann, Uwe; Yano, Junko

    2013-04-26

    Intense femtosecond x-ray pulses produced at the Linac Coherent Light Source (LCLS) were used for simultaneous x-ray diffraction (XRD) and x-ray emission spectroscopy (XES) of microcrystals of photosystem II (PS II) at room temperature. This method probes the overall protein structure and the electronic structure of the Mn4CaO5 cluster in the oxygen-evolving complex of PS II. XRD data are presented from both the dark state (S1) and the first illuminated state (S2) of PS II. Our simultaneous XRD-XES study shows that the PS II crystals are intact during our measurements at the LCLS, not only with respect to the structure of PS II, but also with regard to the electronic structure of the highly radiation-sensitive Mn4CaO5 cluster, opening new directions for future dynamics studies.

  11. Simultaneous measurement of neuronal activity and cortical hemodynamics by unshielded magnetoencephalography and near-infrared spectroscopy

    NASA Astrophysics Data System (ADS)

    Seki, Yusuke; Miyashita, Tsuyoshi; Kandori, Akihiko; Maki, Atsushi; Koizumi, Hideaki

    2012-10-01

    The correlation between neuronal activity and cortical hemodynamics, namely, neurovascular coupling (NVC), is important to shed light on the mechanism of a variety of brain functions or neuronal diseases. NVC can be studied by simultaneously measuring neuronal activity and cortical hemodynamics. Consequently, noninvasive measurements of the NVC have been widely studied using both electroencephalography (EEG) and functional magnetic resonance imaging (fMRI). However, electromagnetic interference between EEG and fMRI is still a major problem. On the other hand, near-infrared spectroscopy (NIRS) is another promising tool for detecting cortical hemodynamics because it can be combined with EEG or magnetoencephalography (MEG) without any electromagnetic interference. Accordingly, in the present study, a simultaneous measurement system-combining an unshielded MEG using a two-dimensional gradiometer based on a low-T superconducting quantum interference device (SQUID) and an NIRS using nonmagnetic thin probes-was developed. This combined system was used to simultaneously measure both an auditory-evoked magnetic field and blood flow change in the auditory cortex. It was experimentally demonstrated that the combined unshielded MEG/NIRS system can simultaneously measure neuronal activity and cortical hemodynamics.

  12. Simultaneous measurement of neuronal activity and cortical hemodynamics by unshielded magnetoencephalography and near-infrared spectroscopy.

    PubMed

    Seki, Yusuke; Miyashita, Tsuyoshi; Kandori, Akihiko; Maki, Atsushi; Koizumi, Hideaki

    2012-10-01

    The correlation between neuronal activity and cortical hemodynamics, namely, neurovascular coupling (NVC), is important to shed light on the mechanism of a variety of brain functions or neuronal diseases. NVC can be studied by simultaneously measuring neuronal activity and cortical hemodynamics. Consequently, noninvasive measurements of the NVC have been widely studied using both electroencephalography (EEG) and functional magnetic resonance imaging (fMRI). However, electromagnetic interference between EEG and fMRI is still a major problem. On the other hand, near-infrared spectroscopy (NIRS) is another promising tool for detecting cortical hemodynamics because it can be combined with EEG or magnetoencephalography (MEG) without any electromagnetic interference. Accordingly, in the present study, a simultaneous measurement system-combining an unshielded MEG using a two-dimensional gradiometer based on a low-Tc superconducting quantum interference device (SQUID) and an NIRS using nonmagnetic thin probes-was developed. This combined system was used to simultaneously measure both an auditory-evoked magnetic field and blood flow change in the auditory cortex. It was experimentally demonstrated that the combined unshielded MEG/NIRS system can simultaneously measure neuronal activity and cortical hemodynamics.

  13. Simultaneous ion luminescence imaging and spectroscopy of individual aerosol particles with external proton or helium microbeams

    NASA Astrophysics Data System (ADS)

    Kada, Wataru; Satoh, Takahiro; Yokoyama, Akihito; Koka, Masashi; Kamiya, Tomihiro

    2014-08-01

    Simultaneous microscopic imaging and spectroscopy of individual aerosol particles were performed with an external microbeam. Visible luminescence induced by the external microbeam was successfully used as a probe to detect organic contaminants in the targets. Combined ion luminescence (IL)/particle-induced X-ray emission (PIXE) analysis of the aerosol targets revealed microscopic chemical and elemental composition distributions under ambient atmospheric conditions. The simple confocal micro-optics for the IL spectroscopy and microscopic imaging were sufficiently sensitive for detecting these molecules at sub-parts per million concentrations and at a wavelength resolution of less than 5 nm. The IL spectra were monitored to prevent severe damage to the samples. Furthermore, our IL system has the advantage that it is simple to add to a conventional micro-PIXE system.

  14. Simultaneous Imaging and Spectroscopy of Detonation Interaction in Reactive and Energetic Materials.

    PubMed

    Johnson, Stephanie; Clemenson, Michael; Glumac, Nick

    2017-01-01

    A dual framing camera system was coupled with custom-designed ultrafast imaging spectrometer optics to yield simultaneous imaging and imaging spectroscopy of extremely short detonation interaction events in reactive materials. For short exposures of 100 ns or less, spectral resolutions of 2.4 Å are achievable, allowing for time-resolved identification of key intermediate species evolving from prompt reaction. Under some circumstances, emission can be fit to a local emission temperature, assuming the optically thin limit. Applications to reactive metal systems involving aluminum, magnesium, titanium, boron, and silicon are demonstrated.

  15. Dynamic High-Resolution H-1 and P-31 NMR Spectroscopy and H-1 T-2 Measurements in Postmortem Rabbit Muscles Using Slow Magic Angle Spinning

    SciTech Connect

    Bertram, Hanne Christine; Hu, Jian Zhi; Rommereim, Donald N.; Wind, Robert A.; Andersen, Henrik J.

    2004-05-05

    Postmortem changes in rabbit muscle tissue with different glycogen status (normal vs low) were followed continuously from 13 min postmortem until 8 h postmortem and again 20 h postmortem using simultaneous magic angle spinning 1H and 31P NMR spectroscopy together with measurement of the transverse relaxation time, T2, of the muscle water. The 1H metabolite spectra were measured using the phase-altered spinning sidebands (PASS) technique at a spinning rate of 40 Hz. pH values calculated from the 31P NMR spectra using the chemical shifts of the C-6 line of histidine in the 1H spectra and the chemical shifts of inorganic phosphate in the 31P spectra confirmed the different muscle glycogen status in the tissues. High-resolution 1H spectra obtained from the PASS technique revealed the presence of a new resonance line at 6.8 ppm during the postmortem period, which were absent in muscles with low muscle glycogen content. This new resonance line may originate from the aminoprotons in creatine, and its appearance may be a result of a pH effect on the exchange rate between the amino and the water protons and thereby the NMR visibility. Alternatively, the new resonance line may originate from the aromatic protons in tyrosine, and its appearance may be a result of a pH-induced protein unfolding exposing hydrophobic amino acid residues to the aqueous environment. Further studies are needed to evaluate these hypotheses. Finally, distributed analysis of the water T2 relaxation data revealed three relaxation populations and an increase in the population believed to reflect extramyofibrillar water through the postmortem period. This increase was significantly reduced (p < 0.0001) in samples from animals with low muscle glycogen content, indicating that the pH is controlling the extent of postmortem expulsion of water from myofibrillar structures. The significance of the postmortem increase in the amount extramyofibrillar water on the water-holding capacity was verified by

  16. AMP promotes oxygen consumption and ATP synthesis in heart mitochondria through the adenylate kinase reaction: an NMR spectroscopy and polarography study.

    PubMed

    Doliba, Nicolai M; Babsky, Andriy M; Doliba, Nataliya M; Wehrli, Suzanne L; Osbakken, Mary D

    2015-03-01

    Adenylate kinase plays an important role in cellular energy homeostasis by catalysing the interconversion of adenine nucleotides. The goal of present study was to evaluate the contribution of the adenylate kinase reaction to oxidative ATP synthesis by direct measurements of ATP using (31) P NMR spectroscopy. Results show that AMP can stimulate ATP synthesis in the presence or absence of ADP. In particular, addition of 1 mM AMP to the 0.6 mM ADP superfusion system of isolated superfused mitochondria (contained and maintained in agarose beads) led to a 25% increase in ATP synthesis as measured by the increase in βATP signal. More importantly, we show that AMP can support ATP synthesis in the absence of ADP, demonstrated as follows. Superfusion of mitochondria without ADP led to the disappearance of ATP γ, α and β signals and the increase of Pi . Addition of AMP to the medium restored the production of ATP, as demonstrated by the reappearance of γ, α and β ATP signals, in conjunction with a decrease in Pi , which is being used for ATP synthesis. Polarographic studies showed Mg(2+) dependence of this process, confirming the specificity of the adenylate kinase reaction. Furthermore, data obtained from this study demonstrate, for the first time, that different aspects of the adenylate kinase reaction can be evaluated with (31) P NMR spectroscopy. SIGNIFICANCE OF RESEARCH PARAGRAPH: The data generated in the present study indicate that (31) P NMR spectroscopy can effectively be used to study the adenylate kinase reaction under a variety of conditions. This is important because understanding of adenylate kinase function and/or malfunction is essential to understanding its role in health and disease. The data obtained with (31) P NMR were confirmed by polarographic studies, which further strengthens the robustness of the NMR findings. In summary, (31) P NMR spectroscopy provides a sensitive tool to study adenylate kinase activity in different physiological and

  17. Classification of edible oils by employing 31P and 1H NMR spectroscopy in combination with multivariate statistical analysis. A proposal for the detection of seed oil adulteration in virgin olive oils.

    PubMed

    Vigli, Georgia; Philippidis, Angelos; Spyros, Apostolos; Dais, Photis

    2003-09-10

    A combination of (1)H NMR and (31)P NMR spectroscopy and multivariate statistical analysis was used to classify 192 samples from 13 types of vegetable oils, namely, hazelnut, sunflower, corn, soybean, sesame, walnut, rapeseed, almond, palm, groundnut, safflower, coconut, and virgin olive oils from various regions of Greece. 1,2-Diglycerides, 1,3-diglycerides, the ratio of 1,2-diglycerides to total diglycerides, acidity, iodine value, and fatty acid composition determined upon analysis of the respective (1)H NMR and (31)P NMR spectra were selected as variables to establish a classification/prediction model by employing discriminant analysis. This model, obtained from the training set of 128 samples, resulted in a significant discrimination among the different classes of oils, whereas 100% of correct validated assignments for 64 samples were obtained. Different artificial mixtures of olive-hazelnut, olive-corn, olive-sunflower, and olive-soybean oils were prepared and analyzed by (1)H NMR and (31)P NMR spectroscopy. Subsequent discriminant analysis of the data allowed detection of adulteration as low as 5% w/w, provided that fresh virgin olive oil samples were used, as reflected by their high 1,2-diglycerides to total diglycerides ratio (D > or = 0.90).

  18. Simultaneous measurement of electroencephalography and near-infrared spectroscopy during voluntary motor preparation

    PubMed Central

    Zama, Takuro; Shimada, Sotaro

    2015-01-01

    We investigated the relationship between electrophysiological activity and haemodynamic response during motor preparation by simultaneous recording of electroencephalography (EEG) and near-infrared spectroscopy (NIRS). It is still unknown how exactly EEG signals correlate with the haemodynamic response, although the activation in the premotor area during motor preparation has been captured by EEG and haemodynamic approaches separately. We conducted EEG-NIRS simultaneous recordings over the sensorimotor area with a self-paced button press task. Participants were instructed to press a button at their own pace after a cue was shown. The result showed that the readiness potential (RP), a negative slow potential shift occurring during motor preparation, on C3 in the extended 10–20 system occurred about 1000 ms before the movement onset. An increase in concentration of oxyhaemoglobin (oxyHb) in the premotor cortex during motor preparation was also confirmed by NIRS, which resulted in a significant correlation between the amplitude of the RP and the change in oxyHb concentration (Pearson’s correlation r2 = 0.235, p = 0.03). We show that EEG-NIRS simultaneous recording can demonstrate the correlation between the RP and haemodynamic response in the premotor cortex contralateral to the performing hand. PMID:26574186

  19. Combining optical trapping in a microfluidic channel with simultaneous micro-Raman spectroscopy and motion detection

    NASA Astrophysics Data System (ADS)

    Lawton, Penelope F.; Saunter, Christopher D.; Girkin, John M.

    2014-03-01

    Since their invention by Ashkin optical tweezers have demonstrated their ability and versatility as a non-invasive tool for micromanipulation. One of the most useful additions to the basic optical tweezers system is micro-Raman spectroscopy, which permits highly sensitive analysis of single cells or particles. We report on the development of a dual laser system combining two spatial light modulators to holographically manipulate multiple traps (at 1064nm) whilst undertaking Raman spectroscopy using a 532nm laser. We can thus simultaneously trap multiple particles and record their Raman spectra, without perturbing the trapping system. The dual beam system is built around micro-fluidic channels where crystallisation of calcium carbonate occurs on polymethylmethacrylate (PMMA) beads. The setup is designed to simulate at a microscopic level the reactions that occur on items in a dishwasher, where permanent filming of calcium carbonate on drinking glasses is a problem. Our system allows us to monitor crystal growth on trapped particles in which the Raman spectrum and changes in movement of the bead are recorded. Due to the expected low level of crystallisation on the bead surfaces this allows us to obtain results quickly and with high sensitivity. The long term goal is to study the development of filming on samples in-situ with the microfl.uidic system acting as a model dishwasher.

  20. Simultaneous optimization by neuro-genetic approach for analysis of plant materials by laser induced breakdown spectroscopy

    NASA Astrophysics Data System (ADS)

    Nunes, Lidiane Cristina; da Silva, Gilmare Antônia; Trevizan, Lilian Cristina; Santos Júnior, Dario; Poppi, Ronei Jesus; Krug, Francisco José

    2009-06-01

    A simultaneous optimization strategy based on a neuro-genetic approach is proposed for selection of laser induced breakdown spectroscopy operational conditions for the simultaneous determination of macro-nutrients (Ca, Mg and P), micro-nutrients (B, Cu, Fe, Mn and Zn), Al and Si in plant samples. A laser induced breakdown spectroscopy system equipped with a 10 Hz Q-switched Nd:YAG laser (12 ns, 532 nm, 140 mJ) and an Echelle spectrometer with intensified coupled-charge device was used. Integration time gate, delay time, amplification gain and number of pulses were optimized. Pellets of spinach leaves (NIST 1570a) were employed as laboratory samples. In order to find a model that could correlate laser induced breakdown spectroscopy operational conditions with compromised high peak areas of all elements simultaneously, a Bayesian Regularized Artificial Neural Network approach was employed. Subsequently, a genetic algorithm was applied to find optimal conditions for the neural network model, in an approach called neuro-genetic. A single laser induced breakdown spectroscopy working condition that maximizes peak areas of all elements simultaneously, was obtained with the following optimized parameters: 9.0 µs integration time gate, 1.1 µs delay time, 225 (a.u.) amplification gain and 30 accumulated laser pulses. The proposed approach is a useful and a suitable tool for the optimization process of such a complex analytical problem.

  1. Beyond hard x-ray photoelectron spectroscopy: Simultaneous combination with x-ray diffraction

    SciTech Connect

    Rubio-Zuazo, Juan; Castro, German R.

    2013-05-15

    Hard x-ray photoelectron spectroscopy (HAXPES) is a powerful and novel emerging technique for the nondestructive determination of electronic properties and chemical composition of bulk, buried interfaces and surfaces. It benefits from the exceptionally large escape depth of high kinetic energy photoelectrons, increasing the information depth up to several tens of nanometers. Complementing HAXPES with an atomic structure sensitive technique (such as x-ray diffraction) opens a new research field with major applications for materials science. At SpLine, the Spanish CRG beamline at the European Synchrotron Radiation Facility, we have developed a novel experimental set-up that combines HAXPES and x-ray diffraction (x-ray reflectivity, surface x-ray diffraction, grazing incidence x-ray diffraction, and reciprocal space maps). Both techniques can be operated simultaneously on the same sample and using the same excitation source. The set-up includes a robust 2S + 3D diffractometer hosting a ultrahigh vacuum chamber equipped with a unique photoelectron spectrometer (few eV < electron kinetic energy < 15 keV), x-ray tube (Mg/Ti), 15 keV electron gun, and auxiliary standard surface facilities (molecular beam epitaxy evaporator, ion gun, low energy electron diffraction, sample heating/cooling system, leak valves, load-lock sample transfer, etc.). This end-station offers the unique possibility of performing simultaneous HAXPES + x-ray diffraction studies. In the present work, we describe the experimental set-up together with two experimental examples that emphasize its outstanding capabilities: (i) nondestructive characterization of the Si/Ge and HfO{sub 2}/SiO{sub 2} interfaces on Ge-based CMOS devices, and (ii) strain study on La{sub 0.7}Ca{sub 0.3}MnO{sub 3} ultrathin films grown on SrTiO{sub 3}(001) substrate.

  2. Simultaneous 19F-1H medium resolution NMR spectroscopy for online reaction monitoring

    NASA Astrophysics Data System (ADS)

    Zientek, Nicolai; Laurain, Clément; Meyer, Klas; Kraume, Matthias; Guthausen, Gisela; Maiwald, Michael

    2014-12-01

    Medium resolution nuclear magnetic resonance (MR-NMR) spectroscopy is currently a fast developing field, which has an enormous potential to become an important analytical tool for reaction monitoring, in hyphenated techniques, and for systematic investigations of complex mixtures. The recent developments of innovative MR-NMR spectrometers are therefore remarkable due to their possible applications in quality control, education, and process monitoring. MR-NMR spectroscopy can beneficially be applied for fast, non-invasive, and volume integrating analyses under rough environmental conditions. Within this study, a simple 1/16″ fluorinated ethylene propylene (FEP) tube with an ID of 0.04″ (1.02 mm) was used as a flow cell in combination with a 5 mm glass Dewar tube inserted into a benchtop MR-NMR spectrometer with a 1H Larmor frequency of 43.32 MHz and 40.68 MHz for 19F. For the first time, quasi-simultaneous proton and fluorine NMR spectra were recorded with a series of alternating 19F and 1H single scan spectra along the reaction time coordinate of a homogeneously catalysed esterification model reaction containing fluorinated compounds. The results were compared to quantitative NMR spectra from a hyphenated 500 MHz online NMR instrument for validation. Automation of handling, pre-processing, and analysis of NMR data becomes increasingly important for process monitoring applications of online NMR spectroscopy and for its technical and practical acceptance. Thus, NMR spectra were automatically baseline corrected and phased using the minimum entropy method. Data analysis schemes were designed such that they are based on simple direct integration or first principle line fitting, with the aim that the analysis directly revealed molar concentrations from the spectra. Finally, the performance of 1/16″ FEP tube set-up with an ID of 1.02 mm was characterised regarding the limit of detection (LOQ (1H) = 0.335 mol L-1 and LOQ (19F) = 0.130 mol L-1 for trifluoroethanol in

  3. Simultaneous prediction of density and moisture content of wood by terahertz time domain spectroscopy

    NASA Astrophysics Data System (ADS)

    Inagaki, Tetsuya; Ahmed, Belal; Hartley, Ian D.; Tsuchikawa, Satoru; Reid, Matthew

    2014-11-01

    In this study, demonstration of simultaneous prediction of solid wood density and moisture content, both of which are critical in manufacturing operations, of 4 species (Aspen, Birch, Hemlock and Maple) was accomplished using terahertz time-domain spectroscopy (THz-TDS). THz measurements of wood at various moisture contents were taken for two orientations of the THz field (parallel and perpendicular) with respect to the visible grain. The real and imaginary parts of the dielectric function averaged over the frequency range of 0.1 to 0.2 THz had strong correlation with density and moisture content of the wood. We extend a model that has been applied previously to oven-dry wood to include the effects of moisture below the fiber saturation point by combining two effective medium models, which allows the dielectric function of water, air and oven-dry cell wall material to be modeled to give an effective dielectric function for the wood. A strong correlation between measured and predicted values for density and moisture content were observed.

  4. Simultaneous Determination of Amiloride and Hydrochlorothiazide in a Compound Tablet by Diffuse Reflectance Spectroscopy and Chemometrics

    NASA Astrophysics Data System (ADS)

    Tang, J.; Li, X.; Feng, Y.; Liang, B.

    2016-09-01

    This paper studies the simultaneous determination of amiloride hydrochloride (AMH) and hydrochlorothiazide (HCTZ) in amiloride hydrochloride tablets by ultraviolet-visible-shortwave near-infrared diffuse reflectance spectroscopy (UV-Vis-swNIR DRS) and chemometrics. Quantitative models for the two components were established by partial least squares (PLS) and support vector regression (SVR), respectively. For the PLS models of AMH and HCTZ, the determination coefficient R2 of the calibration set was 0.9503 and 0.9538, and the coefficient R2 of the prediction set was 0.8983 and 0.9260, respectively. The root mean square error of the calibration set (RMSEC) was 0.8 mg and 8.1 mg, while the root mean square error of the prediction set (RMSEP) was 1.0 mg and 8.7 mg, respectively. For the SVR models of AMH and HCTZ, the R2 of the calibration set was 0.9668 and 0.9609; the R2 of the prediction set was 0.9145 and 0.9446, respectively. The RMSEC was 0.7 and 7.5 mg, and the RMSEP was 0.9 and 8.9 mg, respectively. The results show that SVR modeling has a satisfactory prediction effect. The proposed method based on UV-vis-swNIR and chemometrics is efficient, nondestructive, and expected to be used for online quality monitoring in the production of drugs.

  5. Multichannel wearable system dedicated for simultaneous electroencephalography/near-infrared spectroscopy real-time data acquisitions

    NASA Astrophysics Data System (ADS)

    Lareau, Etienne; Lesage, Frederic; Pouliot, Philippe; Nguyen, Dang; Le Lan, Jerome; Sawan, Mohamad

    2011-09-01

    Functional neuroimaging is becoming a valuable tool in cognitive research and clinical applications. The clinical context brings specific constraints that include the requirement of a high channel count to cover the whole head, high sensitivity for single event detection, and portability for long-term bedside monitoring. For epilepsy and stroke monitoring, the combination of electroencephalography (EEG) and functional near-infrared spectroscopy (NIRS) is expected to provide useful clinical information, and efforts have been deployed to create prototypes able to simultaneously acquire both measurement modalities. However, to the best of our knowledge, existing systems lack portability, NIRS sensitivity, or have low channel count. We present a battery-powered, portable system with potentially up to 32 EEG channels, 32 NIRS light sources, and 32 detectors. Avalanche photodiodes allow for high NIRS sensitivity and the autonomy of the system is over 24 h. A reduced channel count prototype with 8 EEG channels, 8 sources, and 8 detectors was tested on phantoms. Further validation was done on five healthy adults using a visual stimulation protocol to detect local hemodynamic changes and visually evoked potentials. Results show good concordance with literature regarding functional activations and suggest sufficient performance for clinical use, provided some minor adjustments were made.

  6. Structural investigations of PuIII phosphate by X-ray diffraction, MAS-NMR and XANES spectroscopy

    NASA Astrophysics Data System (ADS)

    Popa, Karin; Raison, Philippe E.; Martel, Laura; Martin, Philippe M.; Prieur, Damien; Solari, Pier L.; Bouëxière, Daniel; Konings, Rudy J. M.; Somers, Joseph

    2015-10-01

    PuPO4 was prepared by a solid state reaction method and its crystal structure at room temperature was solved by powder X-ray diffraction combined with Rietveld refinement. High resolution XANES measurements confirm the +III valence state of plutonium, in agreement with valence bond derivation. The presence of the americium (as β- decay product of plutonium) in the +III oxidation state was determined based on XANES spectroscopy. High resolution solid state 31P NMR agrees with the XANES results and the presence of a solid-solution.

  7. Simultaneous UV imaging and raman spectroscopy for the measurement of solvent-mediated phase transformations during dissolution testing.

    PubMed

    Østergaard, Jesper; Wu, Jian X; Naelapää, Kaisa; Boetker, Johan P; Jensen, Henrik; Rantanen, Jukka

    2014-04-01

    The current work reports the simultaneous use of UV imaging and Raman spectroscopy for detailed characterization of drug dissolution behavior including solid-state phase transformations during dissolution. The dissolution of drug substances from compacts of sodium naproxen in 0.1 HCl as well as theophylline anhydrate and monohydrate in water was studied utilizing a flow-through setup. The decreases in dissolution rates with time observed by UV imaging were associated with concomitant solid form changes detected by Raman spectroscopy. Sodium naproxen and theophylline anhydrate were observed to convert to the more stable forms (naproxen, and theophylline monohydrate) within approximately 5 min. Interestingly, the new approach revealed that three intermediate forms are involved in the dissolution process prior to the appearance of the neutral naproxen during dissolution in an acidic medium. The combination of UV imaging and Raman spectroscopy offers a detailed characterization of drug dissolution behavior in a time-effective and sample-sparing manner.

  8. Complex Mixture Analysis of Organic Compounds in Yogurt by NMR Spectroscopy.

    PubMed

    Lu, Yi; Hu, Fangyu; Miyakawa, Takuya; Tanokura, Masaru

    2016-06-16

    NMR measurements do not require separation and chemical modification of samples and therefore rapidly and directly provide non-targeted information on chemical components in complex mixtures. In this study, one-dimensional (¹H, (13)C, and (31)P) and two-dimensional (¹H-(13)C and ¹H-(31)P) NMR spectroscopy were conducted to analyze yogurt without any pretreatment. ¹H, (13)C, and (31)P NMR signals were assigned to 10 types of compounds. The signals of α/β-lactose and α/β-galactose were separately observed in the ¹H NMR spectra. In addition, the signals from the acyl chains of milk fats were also successfully identified but overlapped with many other signals. Quantitative difference spectra were obtained by subtracting the diffusion ordered spectroscopy (DOSY) spectra from the quantitative ¹H NMR spectra. This method allowed us to eliminate interference on the overlaps; therefore, the correct intensities of signals overlapped with those from the acyl chains of milk fat could be determined directly without separation. Moreover, the ¹H-(31)P HMBC spectra revealed for the first time that N-acetyl-d-glucosamine-1-phosphate is contained in yogurt.

  9. Complex Mixture Analysis of Organic Compounds in Yogurt by NMR Spectroscopy

    PubMed Central

    Lu, Yi; Hu, Fangyu; Miyakawa, Takuya; Tanokura, Masaru

    2016-01-01

    NMR measurements do not require separation and chemical modification of samples and therefore rapidly and directly provide non-targeted information on chemical components in complex mixtures. In this study, one-dimensional (1H, 13C, and 31P) and two-dimensional (1H-13C and 1H-31P) NMR spectroscopy were conducted to analyze yogurt without any pretreatment. 1H, 13C, and 31P NMR signals were assigned to 10 types of compounds. The signals of α/β-lactose and α/β-galactose were separately observed in the 1H NMR spectra. In addition, the signals from the acyl chains of milk fats were also successfully identified but overlapped with many other signals. Quantitative difference spectra were obtained by subtracting the diffusion ordered spectroscopy (DOSY) spectra from the quantitative 1H NMR spectra. This method allowed us to eliminate interference on the overlaps; therefore, the correct intensities of signals overlapped with those from the acyl chains of milk fat could be determined directly without separation. Moreover, the 1H-31P HMBC spectra revealed for the first time that N-acetyl-d-glucosamine-1-phosphate is contained in yogurt. PMID:27322339

  10. Inframolecular acid–base and coordination properties towards Na+ and Mg2+ of myo-inositol 1,3,4,5,6-pentakisphosphate: a structural approach to biologically relevant species† †Electronic supplementary information (ESI) available: Application of the Cluster Expansion Method (Table S1); 31P NMR spectra (Fig. S1); Structural details of Ins(1,3,4,5,6)P 5–Mg2+ interaction (Fig. S2); Comparative fit of alternative chemical models for the Ins(1,3,4,5,6)P 5–Na+ system (Fig. S3). See DOI: 10.1039/c2dt31807e Click here for additional data file.

    PubMed Central

    Torres, Julia; Macho, Israel; Gómez, Kerman; Godage, Himali Y.; Riley, Andrew M.; Potter, Barry V. L.; González, Gabriel; Kremer, Carlos

    2013-01-01

    The myo-inositol phosphates (InsPs) are specific signalling metabolites ubiquitous in eukaryotic cells. Although Ins(1,3,4,5,6)P 5 is the second most abundant member of the InsPs family, its certain biological roles are far from being elucidated, in part due to the large number of species formed by Ins(1,3,4,5,6)P 5 in the presence of metal ions. In light of this, we have strived in the past to make a complete and at the same time “biological-user-friendly” description of the Ins(1,3,4,5,6)P 5 chemistry with mono and multivalent cations. In this work we expand these studies focusing on the inframolecular aspects of its protonation equilibria and the microscopic details of its coordination behaviour towards biologically relevant metal ions. We present here a systematic study of the Ins(1,3,4,5,6)P 5 intrinsic acid–base processes, in a non-interacting medium, and over a wide pH range, analyzing the 31P NMR curves by means of a model based on the Cluster Expansion Method. In addition, we have used a computational approach to analyse the energetic and structural features of the protonation and conformational changes of Ins(1,3,4,5,6)P 5, and how they are influenced by the presence of two physiologically relevant cations, Na+ and Mg2+. PMID:23183928

  11. Intermediate valence behavior of Yb2Ni12P7 studied by using 31P NMR

    NASA Astrophysics Data System (ADS)

    Koyama, T.; Sugiura, K.; Ueda, K.; Mito, T.; Kohara, T.; Satoh, R.; Tsuchiya, K.; Nakano, T.; Takeda, N.

    2013-08-01

    The Yb-based heavy-fermion compound Yb2Ni12P7 with a hexagonal Zr2Fe12P7-type crystal structure was investigated by using the 31P nuclear magnetic resonance (NMR) technique. The complicated NMR line changes its shape gradually with decreasing temperature, implying the presence of some Knight shift components. The temperature dependences of the Knight shift and the nuclear spin-lattice relaxation rate 1/ T 1 suggest the delocalization of 4 f electrons.

  12. sup 31 P NMR analysis of coal moieties bearing -OH, -NH, and -SH functions

    SciTech Connect

    Verkade, J.G.

    1991-08-31

    NMR reagents for the speciation and quantitation of labile-hydrogen functional groups and sulfur groups in coal ligands have been synthesized and evaluated. These reagents, which contain the NMR-active nuclei {sup 31}p, {sup 119}Sn or {sup 195}pt, were designed to possess improved chemical shift resolution over reagents reported in the literature. Our efforts were successful in the case of the new {sup 31}p and {sup 119}Sn reagents we developed, but the {sup 195}pt work on sulfur groups was only partially successful in as much as the grant came to a close and was not renewed. Our success with {sup 31}P and {sup 119}Sn NMR reagents came to the attention of Amoco and they have recently expressed interest in further supporting that work. A further measure of the success of our efforts can be seen in the nine publications supported by this grant which are cited in the reference list.

  13. Gated /sup 31/P NMR study of tetanic contraction in rat muscle depleted of phosphocreatine

    SciTech Connect

    Shoubridge, E.A.; Radda, G.K.

    1987-05-01

    Rats were fed a diet containing 1% ..beta..-guanidino-propionic acid (GPA) for 6-12 wk to deplete their muscles of phosphocreatine (PCr). Gated /sup 31/P nuclear magnetic resonance (NMR) spectra were obtained from the gastrocnemius-plantaris muscle at various time points during either a 1- or 3-s isometric tetanic contraction using a surface coil. The energy cost of a 1-s tetanus in unfatigued control rat muscle was 48.4 ..mu..mol ATP x g dry wt/sup -1/ x s/sup -1/ and was largely supplied by PCr; anaerobic glycogenolysis was negligible. In GPA-fed rats PCr was undetectable after 400 ms. This had no effect on initial force generated per gram, which was not significantly different from controls. Developed tension in a 3-s tetanus in GPA-fed rats could be divided into a peak phase (duration 0.8-0.9 s) and a plateau phase (65% peak tension) in which PCr was undetectable and the (ATP) was < 20% of that in control muscle. Energy from glycogenolysis was sufficient to maintain force generation at this submaximal level. Mean net glycogen utilization per 3-s tetanus was 78% greater than in control muscle. However, the observed decrease in intracellular pH was less than that expected from energy budget calculations, suggesting either increased buffering capacity or modulation of ATP hydrolysis in the muscles of GPA-fed rats. The results demonstrate that the transport role of PCr is not essential in contracting muscle in GPA-fed rats. PCr is probably important in this regard in the larger fibers of control muscle. Although fast-twitch muscles depleted of PCr have nearly twice the glycogen reserves of control muscle, glycogenolysis is limited in its capacity to fill the role of PCr as an energy buffer under conditions of maximum ATP turnover.

  14. Multibeam long-path differential optical absorption spectroscopy instrument: a device for simultaneous measurements along multiple light paths.

    PubMed

    Pundt, Irene; Mettendorf, Kai Uwe

    2005-08-10

    A novel long-path differential optical absorption spectroscopy (DOAS) apparatus for measuring tropospheric trace gases and the first results from its use are presented: We call it the multibeam instrument. It is the first active DOAS device that emits several light beams simultaneously through only one telescope and with only one lamp as a light source, allowing simultaneous measurement along multiple light paths. In contrast to conventional DOAS instruments, several small mirrors are positioned near the lamp, creating multiple virtual light sources that emit one light beam each in one specific direction. The possibility of error due to scattering between the light beams is negligible. The trace-gas detection limits of NO2, SO2, O3, and H2CO are similar to those of the traditional long-path DOAS instrument.

  15. Communication: two-dimensional gas-phase coherent anti-Stokes Raman spectroscopy (2D-CARS): simultaneous planar imaging and multiplex spectroscopy in a single laser shot.

    PubMed

    Bohlin, Alexis; Kliewer, Christopher J

    2013-06-14

    Coherent anti-Stokes Raman spectroscopy (CARS) has been widely used as a powerful tool for chemical sensing, molecular dynamics measurements, and rovibrational spectroscopy since its development over 30 years ago, finding use in fields of study as diverse as combustion diagnostics, cell biology, plasma physics, and the standoff detection of explosives. The capability for acquiring resolved CARS spectra in multiple spatial dimensions within a single laser shot has been a long-standing goal for the study of dynamical processes, but has proven elusive because of both phase-matching and detection considerations. Here, by combining new phase matching and detection schemes with the high efficiency of femtosecond excitation of Raman coherences, we introduce a technique for single-shot two-dimensional (2D) spatial measurements of gas phase CARS spectra. We demonstrate a spectrometer enabling both 2D plane imaging and spectroscopy simultaneously, and present the instantaneous measurement of 15,000 spatially correlated rotational CARS spectra in N2 and air over a 2D field of 40 mm(2).

  16. Communication: Two-dimensional gas-phase coherent anti-Stokes Raman spectroscopy (2D-CARS): Simultaneous planar imaging and multiplex spectroscopy in a single laser shot

    NASA Astrophysics Data System (ADS)

    Bohlin, Alexis; Kliewer, Christopher J.

    2013-06-01

    Coherent anti-Stokes Raman spectroscopy (CARS) has been widely used as a powerful tool for chemical sensing, molecular dynamics measurements, and rovibrational spectroscopy since its development over 30 years ago, finding use in fields of study as diverse as combustion diagnostics, cell biology, plasma physics, and the standoff detection of explosives. The capability for acquiring resolved CARS spectra in multiple spatial dimensions within a single laser shot has been a long-standing goal for the study of dynamical processes, but has proven elusive because of both phase-matching and detection considerations. Here, by combining new phase matching and detection schemes with the high efficiency of femtosecond excitation of Raman coherences, we introduce a technique for single-shot two-dimensional (2D) spatial measurements of gas phase CARS spectra. We demonstrate a spectrometer enabling both 2D plane imaging and spectroscopy simultaneously, and present the instantaneous measurement of 15 000 spatially correlated rotational CARS spectra in N2 and air over a 2D field of 40 mm2.

  17. Communication: Two-dimensional gas-phase coherent anti-Stokes Raman spectroscopy (2D-CARS): Simultaneous planar imaging and multiplex spectroscopy in a single laser shot

    SciTech Connect

    Bohlin, Alexis; Kliewer, Christopher J.

    2013-01-01

    Coherent anti-Stokes Raman spectroscopy (CARS) has been widely used as a powerful tool for chemical sensing, molecular dynamics measurements, and rovibrational spectroscopy since its development over 30 years ago, finding use in fields of study as diverse as combustion diagnostics, cell biology, plasma physics, and the standoff detection of explosives. The capability for acquiring resolved CARS spectra in multiple spatial dimensions within a single laser shot has been a long-standing goal for the study of dynamical processes, but has proven elusive because of both phase-matching and detection considerations. Here, by combining new phase matching and detection schemes with the high efficiency of femtosecond excitation of Raman coherences, we introduce a technique for single-shot two-dimensional (2D) spatial measurements of gas phase CARS spectra. We demonstrate a spectrometer enabling both 2D plane imaging and spectroscopy simultaneously, and present the instantaneous measurement of 15, 000 spatially correlated rotational CARS spectra in N2 and air over a 2D field of 40 mm2.

  18. Growth of block copolymer stabilized metal nanoparticles probed simultaneously by in situ XAS and UV-Vis spectroscopy.

    PubMed

    Nayak, C; Bhattacharyya, D; Jha, S N; Sahoo, N K

    2016-01-01

    The growth of Au and Pt nanoparticles from their respective chloride precursors using block copolymer-based reducers has been studied by simultaneous in situ measurement of XAS and UV-Vis spectroscopy at the energy-dispersive EXAFS beamline (BL-08) at INDUS-2 SRS at RRCAT, Indore, India. While the XANES spectra of the precursor give real-time information on the reduction process, the EXAFS spectra reveal the structure of the clusters formed at the intermediate stages of growth. The growth kinetics of both types of nanoparticles are found to be almost similar and are found to follow three stages, though the first stage of nucleation takes place earlier in the case of Au than in the case of Pt nanoparticles due to the difference in the reduction potential of the respective precursors. The first two stages of the growth of Au and Pt nanoparticles as obtained by in situ XAS measurements could be corroborated by simultaneous in situ measurement of UV-Vis spectroscopy also.

  19. Dynamics of cortical neurovascular coupling analyzed by simultaneous DC-magnetoencephalography and time-resolved near-infrared spectroscopy.

    PubMed

    Mackert, Bruno-Marcel; Leistner, Stefanie; Sander, Tilmann; Liebert, Adam; Wabnitz, Heidrun; Burghoff, Martin; Trahms, Lutz; Macdonald, Rainer; Curio, Gabriel

    2008-02-01

    Functional magnetic resonance imaging (fMRI) visualizes activated brain areas with a high spatial resolution. The activation signal is determined by the local change of cerebral blood oxygenation, blood volume and blood flow which serve as surrogate marker for the neuronal signal itself. Here, the complex coupling between these parameters and the electrophysiologic activity is characterized non-invasively in humans during a simple motor task using simultaneously DC-magnetoencephalography (DC-MEG), for the detection of neuronal signals, and time-resolved near-infrared spectroscopy (trNIRS), for cortical metabolic/vascular responses: over the left primary motor cortex hand area of healthy subjects DC-fields and trNIRS parameters followed closely the 30 s motor task cycles, i.e., finger movements of the right hand alternating with rest. In subjects showing a sufficient signal-to-noise ratio the analysis of variance of photon time of flight proved that the task-related trNIRS changes originated from the cortex. While onset and relaxation started simultaneously, trNIRS signals reached 50% of the maximum level 1-4 s later than the DC-MEG-signals. The non-invasive 'dual' setup helps to characterize simultaneously the two complementary aspects of the 'hemodynamic inverse problem', i.e., the coupling of neuronal and vascular/metabolic signals, in healthy subjects and provides a new analysis perspective for pathophysiological coupling concepts in diverse diseases, e.g., in stroke, hypertension and Alzheimer's disease.

  20. Scanning angle Raman spectroscopy: A nondestructive method for simultaneously determining mixed polymer fractional composition and film thickness

    DOE PAGES

    Bobbitt, Jonathan M.; Mendivelso-Pérez, Deyny; Smith, Emily A.

    2016-11-03

    A scanning angle (SA) Raman spectroscopy method was developed to simultaneously measure the chemical composition and thickness of waveguide mixed polymer films with varying fractional compositions. In order to test the method, six films of polystyrene-block-poly(methyl methacrylate), some mixed with poly(methyl methacrylate) homopolymer (PS-b-PMMA:PMMA), and two films of poly(2-vinylnapthalene)-block-poly(methyl methacrylate) (P2VN-b-PMMA) were prepared. The film thickness ranged from 495 to 971 nm. The chemical composition and thickness of PS-b-PMMA:PMMA films was varied by the addition of the PMMA homopolymer and annealing the films in toluene. SA Raman peak amplitude ratios (1001 cm-1 for PS, 812 cm-1 for PMMA, and 1388more » cm-1 for P2VN) were used to calculate the refractive index of the polymer film, an input parameter in calculations of the sum square electric field (SSEF). The film thickness was determined by SSEF models of the experimental Raman amplitudes versus the incident angle of light. The average film thickness determined by the developed SA Raman spectroscopy method was within 5% of the value determined by optical profilometry. In conclusion, SA Raman spectroscopy will be useful for in situ label-free analyses of mixed polymer waveguide films.« less

  1. Scanning angle Raman spectroscopy: A nondestructive method for simultaneously determining mixed polymer fractional composition and film thickness

    SciTech Connect

    Bobbitt, Jonathan M.; Mendivelso-Pérez, Deyny; Smith, Emily A.

    2016-11-03

    A scanning angle (SA) Raman spectroscopy method was developed to simultaneously measure the chemical composition and thickness of waveguide mixed polymer films with varying fractional compositions. In order to test the method, six films of polystyrene-block-poly(methyl methacrylate), some mixed with poly(methyl methacrylate) homopolymer (PS-b-PMMA:PMMA), and two films of poly(2-vinylnapthalene)-block-poly(methyl methacrylate) (P2VN-b-PMMA) were prepared. The film thickness ranged from 495 to 971 nm. The chemical composition and thickness of PS-b-PMMA:PMMA films was varied by the addition of the PMMA homopolymer and annealing the films in toluene. SA Raman peak amplitude ratios (1001 cm-1 for PS, 812 cm-1 for PMMA, and 1388 cm-1 for P2VN) were used to calculate the refractive index of the polymer film, an input parameter in calculations of the sum square electric field (SSEF). The film thickness was determined by SSEF models of the experimental Raman amplitudes versus the incident angle of light. The average film thickness determined by the developed SA Raman spectroscopy method was within 5% of the value determined by optical profilometry. In conclusion, SA Raman spectroscopy will be useful for in situ label-free analyses of mixed polymer waveguide films.

  2. Simultaneous measurements of temperature and density in air flows using UV laser spectroscopy

    NASA Technical Reports Server (NTRS)

    Fletcher, D. G.; Mckenzie, R. L.

    1991-01-01

    The simultaneous measurement of temperature and density using laser-induced fluorescence of oxygen in combination with Q-branch Raman scattering of nitrogen and oxygen is demonstrated in a low-speed air flow. The lowest density and temperature measured in the experiment correspond to the freestream values at Mach 5 in the Ames 3.5-Foot Hypersonic Wind Tunnel for stagnation conditions of 100 atm and 1000 K. The experimental results demonstrate the viability of the optical technique for measurements that support the study of compressible turbulence and the validation of numerical codes in supersonic and hypersonic wind tunnel flows.

  3. In Situ Planetary Mineralogy Using Simultaneous Time Resolved Fluorescence and Raman Spectroscopy

    NASA Technical Reports Server (NTRS)

    Blacksberg, J.; Rossman , G.R.

    2011-01-01

    Micro-Raman spectroscopy is one of the primary methods of mineralogical analysis in the laboratory, and more recently in the field. Because of its versatility and ability to interrogate rocks in their natural form it is one of the front runners for the next generation of in situ instruments designed to explore adverse set of solar system bodies (e.g. Mars, Venus, the Moon, and other primitive bodies such as asteroids and the Martian moons Phobos and Deimos), as well as for pre-selection of rock and soil samples for potential cache and return missions.

  4. In-situ determination of dispersion and resolving power in simultaneous multiple-angle XUV spectroscopy

    NASA Astrophysics Data System (ADS)

    Zastrau, U.; Hilbert, V.; Brown, C.; Döppner, T.; Dziarzhytski, S.; Förster, E.; Glenzer, S. H.; Göde, S.; Gregori, G.; Harmand, M.; Hochhaus, D.; Laarmann, T.; Lee, H. J.; Meiwes-Broer, K.-H.; Neumayer, P.; Przystawik, A.; Radcliffe, P.; Schulz, M.; Skruszewicz, S.; Tavella, F.; Tiggesbäumker, J.; Toleikis, S.; White, T.

    2011-10-01

    We report on the simultaneous determination of non-linear dispersion functions and resolving power of three flat-field XUV grating spectrometers. A moderate-intense short-pulse infrared laser is focused onto technical aluminum which is commonly present as part of the experimental setup. In the XUV wavelength range of 10-19 nm, the spectrometers are calibrated using Al-Mg plasma emission lines. This cross-calibration is performed in-situ in the very same setup as the actual main experiment. The results are in excellent agreement with ray-tracing simulations. We show that our method allows for precise relative and absolute calibration of three different XUV spectrometers.

  5. Simultaneous visible and ultraviolet spectroscopy of stellar wind variability in Zeta Puppis

    NASA Technical Reports Server (NTRS)

    Wegner, G. A.; Snow, T. P., Jr.

    1978-01-01

    Spectra of He II 4686 A and H-alpha in Zeta Pup were obtained simultaneously with Copernicus ultraviolet scans of several P Cygni profiles in this O4 If supergiant with strong mass loss. The visible-wavelength data show significant variations in the profiles of both lines, consisting of doubling of the emission over times of less than a day. Recent theoretical calculations show that the observed profile variations in 4686 A can be produced by significant fluctuations in the wind density. The Copernicus data show less variability, although in one scan of the 1400-A Si IV doublet there appears to be a significant enhancement of the emission which may be correlated with one of the doublings observed in 4686 A and H-alpha, as though a density enhancement formed at low levels and then moved outward in the wind.

  6. Simultaneously probing two ultrafast condensed-phase molecular symmetry breaking events by two-dimensional infrared spectroscopy.

    PubMed

    Yang, Fan; Yu, Pengyun; Zhao, Juan; Wang, Jianping

    2013-08-05

    In condensed phases, a highly symmetric gas-phase molecule lowers its symmetry under perturbation of the solvent, which is vital to a variety of structural chemistry related processes. However, the dynamical aspects of solvent-mediated symmetry-breaking events remain largely unknown. Herein, direct evidence for two types of solvent-mediated symmetry-breaking events that coexist on the picosecond timescale in a highly symmetric anion, namely, hexacyanocobaltate, is presented: 1) an equilibrium symmetry-breaking event in which a solvent-bound species having lowered symmetry undergoes a population exchange reaction with the symmetry-retaining species; 2) a dynamic symmetry-breaking event that is composed of many dynamic population-exchange reactions under fluctuating solvent interactions. Ultrafast two-dimensional infrared spectroscopy is used to simultaneously observe and dynamically characterize these two events. This work opens a new window into molecular symmetry and structural dynamics under equilibrium and non-equilibrium conditions.

  7. Probing the interaction of U(VI) with phosphonate-functionalized mesoporous silica using solid-state NMR spectroscopy

    DOE PAGES

    Uribe, Eva C.; Mason, Harris E.; Shusterman, Jennifer A.; ...

    2016-05-30

    The fundamental interaction of U(VI) with diethylphosphatoethyl triethoxysilane functionalized SBA-15 mesoporous silica is studied by macroscopic batch experiments and solid-state NMR spectroscopy. DPTS-functionalized silica has been shown to extract U(VI) from nitric acid solutions at or above pH 3. Extraction is dependent on pH and ionic strength. Single-pulse 31P NMR on U(VI) contacted samples revealed that U(VI)only interacts with a fraction of the ligands present on the surface. At pH 4 the U(VI) extraction capacity of the material is limited to 27–37% of the theoretical capacity, based on ligand loading. We combined single pulse 31P NMR on U(VI)-contacted samples withmore » batch studies to measure a ligand-to-metal ratio of approximately 2 : 1 at pH 3 and 4. Batch studies and cross-polarization NMR measurements reveal that U(VI) binds to deprotonated phosphonate and/or silanol sites. We use 31P–31P DQ-DRENAR NMR studies to compare the average dipolar coupling between phosphorus spins for both U(VI)-complexed and non-complexed ligand environments. Furthermore, these measurements reveal that U(VI) extraction is not limited by inadequate surface distribution of ligands, but rather by low stability of the surface phosphonate complex.« less

  8. Probing the interaction of U(vi) with phosphonate-functionalized mesoporous silica using solid-state NMR spectroscopy.

    PubMed

    Uribe, Eva C; Mason, Harris E; Shusterman, Jennifer A; Bruchet, Anthony; Nitsche, Heino

    2016-06-21

    The fundamental interaction of U(vi) with diethylphosphatoethyl triethoxysilane functionalized SBA-15 mesoporous silica is studied by macroscopic batch experiments and solid-state NMR spectroscopy. DPTS-functionalized silica has been shown to extract U(vi) from nitric acid solutions at or above pH 3. Extraction is dependent on pH and ionic strength. Single-pulse (31)P NMR on U(vi) contacted samples revealed that U(vi) only interacts with a fraction of the ligands present on the surface. At pH 4 the U(vi) extraction capacity of the material is limited to 27-37% of the theoretical capacity, based on ligand loading. We combined single pulse (31)P NMR on U(vi)-contacted samples with batch studies to measure a ligand-to-metal ratio of approximately 2 : 1 at pH 3 and 4. Batch studies and cross-polarization NMR measurements reveal that U(vi) binds to deprotonated phosphonate and/or silanol sites. We use (31)P-(31)P DQ-DRENAR NMR studies to compare the average dipolar coupling between phosphorus spins for both U(vi)-complexed and non-complexed ligand environments. These measurements reveal that U(vi) extraction is not limited by inadequate surface distribution of ligands, but rather by low stability of the surface phosphonate complex.

  9. Tumour oxygen dynamics measured simultaneously by near-infrared spectroscopy and 19F magnetic resonance imaging in rats

    NASA Astrophysics Data System (ADS)

    Xia, Mengna; Kodibagkar, Vikram; Liu, Hanli; Mason, Ralph P.

    2006-01-01

    Simultaneous near-infrared spectroscopy (NIRS) and magnetic resonance imaging (MRI) were used to investigate the correlation between tumour vascular oxygenation and tissue oxygen tension dynamics in rat breast 13762NF tumours with respect to hyperoxic gas breathing. NIRS directly detected global variations in the oxygenated haemoglobin concentration (Δ[HbO2]) within tumours and oxygen tension (pO2) maps were achieved using 19F MRI of the reporter molecule hexafluorobenzene. Multiple correlations were examined between rates and magnitudes of vascular (Δ[HbO2]) and tissue (pO2) responses. Significant correlations were found between response to oxygen and carbogen breathing using either modality. Comparison of results for the two methods showed a correlation between the vascular perfusion rate ratio and the mean pO2 values (R2 > 0.7). The initial rates of increase of Δ[HbO2] and the slope of dynamic pO2 response, d(pO2)/dt, of well-oxygenated voxels in response to hyperoxic challenge were also correlated. These results demonstrate the feasibility of simultaneous measurements using NIRS and MRI. As expected, the rate of pO2 response to oxygen is primarily dependent upon the well perfused rather than poorly perfused vasculature. Presented in part at the 12th annual meeting of the International Society of Magnetic Resonance in Medicine, Kyoto, 2004.

  10. Polyoxomolybdate promoted hydrolysis of a DNA-model phosphoester studied by NMR and EXAFS spectroscopy.

    PubMed

    Absillis, Gregory; Van Deun, Rik; Parac-Vogt, Tatjana N

    2011-11-21

    Hydrolysis of (p-nitrophenyl)phosphate (NPP), a commonly used phosphatase model substrate, was examined in molybdate solutions by means of (1)H, (31)P, and (95)Mo NMR spectroscopy and Mo K-edge Extended X-ray Absorption Fine Structure (EXAFS) spectroscopy. At 50 °C and pD 5.1 the cleavage of the phosphoester bond in NPP proceeds with a rate constant of 2.73 × 10(-5) s(-1) representing an acceleration of nearly 3 orders of magnitude as compared to the hydrolysis measured in the absence of molybdate. The pD dependence of k(obs) exhibits a bell-shaped profile, with the fastest cleavage observed in solutions where [Mo(7)O(24)](6-) is the major species in solution. Mixing of NPP and [Mo(7)O(24)](6-) resulted in formation of these two intermediate complexes that were detected by (31)P NMR spectroscopy. Complex A was characterized by a (31)P NMR resonance at -4.27 ppm and complex B was characterized by a (31)P NMR resonance at -7.42 ppm. On the basis of the previous results from diffusion ordered NMR spectroscopy, performed with the hydrolytically inactive substrate phenylphosphonate (PhP), the structure of these two complexes was deduced to be (NPP)(2)Mo(5)O(21)(4-) (complex A) and (NPP)(2)Mo(12)O(36)(H(2)O)(6)(4-) (complex B). The pH studies point out that both complexes are hydrolytically active and lead to the hydrolysis of phosphoester bond in NPP. The NMR spectra did not show evidence of any paramagnetic species, excluding the possibility of Mo(VI) reduction to Mo(V), and indicating that the cleavage of the phosphomonoester bond is purely hydrolytic. The Mo K-edge XANES region also did not show any sign of Mo(VI) to Mo(V) reduction during the hydrolytic reaction. (95)Mo NMR and Mo K-edge EXAFS spectra measured during different stages of the hydrolytic reaction showed a gradual disappearance of [Mo(7)O(24)](6-) during the hydrolytic reaction and appearance of [P(2)Mo(5)O(23)](6-), which was the final complex observed at the end of hydrolytic reaction.

  11. Simultaneous X-ray and optical spectroscopy of the Oef supergiant λ Cephei

    NASA Astrophysics Data System (ADS)

    Rauw, G.; Hervé, A.; Nazé, Y.; González-Pérez, J. N.; Hempelmann, A.; Mittag, M.; Schmitt, J. H. M. M.; Schröder, K.-P.; Gosset, E.; Eenens, P.; Uuh-Sonda, J. M.

    2015-08-01

    Context. Probing the structures of stellar winds is of prime importance for the understanding of massive stars. Based on their optical spectral morphology and variability, it has been suggested that the stars in the Oef class feature large-scale structures in their wind. Aims: High-resolution X-ray spectroscopy and time-series of X-ray observations of presumably single O-type stars can help us understand the physics of their stellar winds. Methods: We have collected XMM-Newton observations and coordinated optical spectroscopy of the O6 Ief star λ Cep to study its X-ray and optical variability and to analyse its high-resolution X-ray spectrum. We investigate the line profile variability of the He ii λ 4686 and Hα emission lines in our time series of optical spectra, including a search for periodicities. We further discuss the variability of the broadband X-ray flux and analyse the high-resolution spectrum of λ Cep using line-by-line fits as well as a code designed to fit the full high-resolution X-ray spectrum consistently. Results: During our observing campaign, the He ii λ 4686 line varies on a timescale of ~18 h. On the contrary, the Hα line profile displays a modulation on a timescale of 4.1 days which is likely the rotation period of the star. The X-ray flux varies on timescales of days and could in fact be modulated by the same 4.1-day period as Hα, although both variations are shifted in phase. The high-resolution X-ray spectrum reveals broad and skewed emission lines as expected for the X-ray emission from a distribution of wind-embedded shocks. Most of the X-ray emission arises within less than 2 R∗ above the photosphere. Conclusions: The properties of the X-ray emission of λ Cep generally agree with the expectations of the wind-embedded shock model. There is mounting evidence for the existence of large-scale structures that modulate the Hα line and about 10% of the X-ray emission of λ Cep. Based on observations collected with XMM-Newton, an ESA

  12. Transient Grating Spectroscopy in Magnetic Thin Films: Simultaneous Detection of Elastic and Magnetic Dynamics

    PubMed Central

    Janušonis, J.; Jansma, T.; Chang, C. L.; Liu, Q.; Gatilova, A.; Lomonosov, A. M.; Shalagatskyi, V.; Pezeril, T.; Temnov, V. V.; Tobey, R. I.

    2016-01-01

    Surface magnetoelastic waves are coupled elastic and magnetic excitations that propagate along the surface of a magnetic material. Ultrafast optical techniques allow for a non-contact excitation and detection scheme while providing the ability to measure both elastic and magnetic components individually. Here we describe a simple setup suitable for excitation and time resolved measurements of high frequency magnetoelastic waves, which is based on the transient grating technique. The elastic dynamics are measured by diffracting a probe laser pulse from the long-wavelength spatially periodic structural deformation. Simultaneously, a magnetooptical measurement, either Faraday or Kerr effect, is sensitive to the out-of-plane magnetization component. The correspondence in the response of the two channels probes the resonant interaction between the two degrees of freedom and reveals their intimate coupling. Unraveling the observed dynamics requires a detailed understanding of the spatio-temporal evolution of temperature, magnetization and thermo-elastic strain in the ferromagnet. Numerical solution of thermal diffusion in two dimensions provides the basis on which to understand the sensitivity in the magnetooptic detection. PMID:27377262

  13. Transient Grating Spectroscopy in Magnetic Thin Films: Simultaneous Detection of Elastic and Magnetic Dynamics.

    PubMed

    Janušonis, J; Jansma, T; Chang, C L; Liu, Q; Gatilova, A; Lomonosov, A M; Shalagatskyi, V; Pezeril, T; Temnov, V V; Tobey, R I

    2016-07-05

    Surface magnetoelastic waves are coupled elastic and magnetic excitations that propagate along the surface of a magnetic material. Ultrafast optical techniques allow for a non-contact excitation and detection scheme while providing the ability to measure both elastic and magnetic components individually. Here we describe a simple setup suitable for excitation and time resolved measurements of high frequency magnetoelastic waves, which is based on the transient grating technique. The elastic dynamics are measured by diffracting a probe laser pulse from the long-wavelength spatially periodic structural deformation. Simultaneously, a magnetooptical measurement, either Faraday or Kerr effect, is sensitive to the out-of-plane magnetization component. The correspondence in the response of the two channels probes the resonant interaction between the two degrees of freedom and reveals their intimate coupling. Unraveling the observed dynamics requires a detailed understanding of the spatio-temporal evolution of temperature, magnetization and thermo-elastic strain in the ferromagnet. Numerical solution of thermal diffusion in two dimensions provides the basis on which to understand the sensitivity in the magnetooptic detection.

  14. Solid-state Hadamard NMR spectroscopy: simultaneous measurements of multiple selective homonuclear scalar couplings.

    PubMed

    Kakita, Veera Mohana Rao; Kupče, Eriks; Bharatam, Jagadeesh

    2015-02-01

    Unambiguous measurement of homonuclear scalar couplings (J) in multi-spin scalar network systems is not straightforward. Further, the direct measurement of J-couplings is obscured in solid-state samples due to the dipolar and chemical shift anisotropy (CSA)-dominated line broadening, even under the magic angle spinning (MAS). We present a new multiple frequency selective spin-echo method based on Hadamard matrix encoding, for simultaneous measurement of multiple homonuclear scalar couplings (J) in the solid-state. In contrast to the Hadamard encoded selective excitation schemes known for the solution-state, herein the selectivity is achieved during refocusing period. The Hadamard encoded refocusing scheme concurrently allows to create the spin-spin commutation property between number of spin-pairs of choice in uniformly labelled molecules, which, therefore avoids (1) the repetition of the double selective refocusing experiments for each spin-pair and (2) the synthesis of expensive selective labelled molecules. The experimental scheme is exemplified for determining (1)JCC and (3)JCC values in (13)C6l-Histidine.HCl molecule, which are found to be in excellent agreement with those measured in conventional double frequency selective refocusing mode as well as in the solution-state. This method can be simply extended to 2D/3D pulse schemes and be applied to small bio-molecular solids.

  15. Polarization-modulation infrared reflection-absorption spectroscopy affording time-resolved simultaneous detection of surface and liquid phase species at catalytic solid-liquid interfaces.

    PubMed

    Meier, Daniel M; Urakawa, Atsushi; Baiker, Alfons

    2009-09-01

    Polarization-modulation infrared reflection-absorption spectroscopy (PM-IRRAS) combined with concentration modulation allows simultaneous monitoring of dynamic evolutions of surface and liquid phase species during reactions at catalytic interfaces as demonstrated for the Pt-catalysed oxidation of CO by O2 in cyclohexane.

  16. Simultaneous detection of trace metal ions in water by solid phase extraction spectroscopy combined with multivariate calibration

    NASA Astrophysics Data System (ADS)

    Wang, Lei; Cao, Peng; Li, Wei; Tong, Peijin; Zhang, Xiaofang; Du, Yiping

    2016-04-01

    Solid Phase Extraction Spectroscopy (SPES) developed in this paper is a technique to measure spectrum directly on the solid phase material where the analytes are concentrated in SPE process. Membrane enrichment and UV-Visible spectroscopy were utilized to fulfill SPES, and multivariate calibration method of partial least squares (PLS) was used to simultaneously detect the concentrations of trace cobalt (II) and zinc (II) in water samples. The proposed method is simple, sensitive and selective. The complexes of analyte ions were collected on the cellulose acetate membranes via membrane filtration after the complexation reaction with 1-2-pyridylazo 2-naphthol (PAN). The spectra of the membranes which contained the complexes of metal ions and PAN were measured directly without eluting. The analytical conditions including pH, reaction time, sample volume, the amount of PAN, and flow rates were optimized. Nonionic surfactant Brij-30 was absorbed on the membranes prior to SPES to modify the membranes for improving the enrichment and spectrum measurement. The interference from other ions to the determination was investigated. Under the optimal condition, the absorbance was linearly related to the concentration at the range of 0.1-3.0 μg/L and 0.1-2.0 μg/L, with the correlation coefficients (R2) of 0.9977 and 0.9951 for Co (II) and Zn (II), respectively. The limits of detection were 0.066 μg/L for cobalt (II) and 0.104 μg/L for zinc (II). PLS regression with leave-one-out cross-validation was utilized to build models to detect cobalt (II) and zinc (II) in drinking water samples simultaneously. The correlation coefficient between ion concentration and spectrum of calibration set and independent prediction set were 1.0000 and 0.9974 for cobalt (II) and 1.0000 and 0.9956 for zinc (II). For cobalt (II) and zinc (II), the errors of the prediction set were in the range 0.0406-0.1353 μg/L and 0.0025-0.1884 μg/L.

  17. Spectroscopy system based on a single quantum cascade laser for simultaneous detection of CO and CO2

    NASA Astrophysics Data System (ADS)

    Wei, Min; Ye, Qing-Hao; Kan, Rui-Feng; Chen, Bing; Yang, Chen-Guang; Xu, Zhen-Yu; Chen, Xiang; Ruan, Jun; Fan, Xue-Li; Wang, Wei; Hu, Mai; Liu, Jian-Guo

    2016-09-01

    A quantum cascade laser (QCL) based system for simultaneous detection of CO and CO2 is developed. The QCL can scan over two neighboring CO (2055.40 cm-1) and CO2 (2055.16 cm-1) lines with a single current scan. The wavelength modulation spectroscopy (f = 20 kHz) is utilized to enhance the signal-to-noise ratio. A white cell with an effective optical path length of 74 m is used. The calibration of the sensor is performed and minimum detection limits of 1.3 ppb (1 × 10-9) for CO and 0.44 ppm (1 × 10-6) for CO2 are achieved. Project supported by the National Key Scientific Instrument and Equipment Development Project of China (Grnat No. 2014YQ060537), the National Basic Research Program of China (Grant No. 2013CB632803), the Strategic Priority Research Program of the Chinese Academy of Sciences (Grant No. XDA05040102), and the National Natural Science Foundation of China (Grant No. 41405134).

  18. Simultaneous blood flow and blood oxygenation measurements using a combination of diffuse speckle contrast analysis and near-infrared spectroscopy

    NASA Astrophysics Data System (ADS)

    Seong, Myeongsu; Phillips, Zephaniah; Mai, Phuong Minh; Yeo, Chaebeom; Song, Cheol; Lee, Kijoon; Kim, Jae Gwan

    2016-02-01

    A combined diffuse speckle contrast analysis (DSCA)-near-infrared spectroscopy (NIRS) system is proposed to simultaneously measure qualitative blood flow and blood oxygenation changes in human tissue. The system employs an optical switch to alternate two laser sources at two different wavelengths and a CCD camera to capture the speckle image. Therefore, an optical density can be measured from two wavelengths for NIRS measurements and a speckle contrast can be calculated for DSCA measurements. In order to validate the system, a flow phantom test and an arm occlusion protocol for arterial and venous occlusion were performed. Shorter exposure times (<1 ms) show a higher drop (between 50% and 66%) and recovery of 1/KS2 values after occlusion (approximately 150%), but longer exposure time (3 ms) shows more consistent hemodynamic changes. For four subjects, the 1/KS2 values dropped to an average of 82.1±4.0% during the occlusion period and the average recovery of 1/KS2 values after occlusion was 109.1±0.8%. There was also an approximately equivalent amplitude change in oxyhemoglobin (OHb) and deoxyhemoglobin (RHb) during arterial occlusion (max RHb=0.0085±0.0024 mM/DPF, min OHb=-0.0057±0.0044 mM/DPF). The sensitivity of the system makes it a suitable modality to observe qualitative hemodynamic trends during induced physiological changes.

  19. Simultaneous determination of 2-naphthoxyacetic acid and indole-3-acetic acid by first derivation synchronous fluorescence spectroscopy

    NASA Astrophysics Data System (ADS)

    Liu, Xiangxiang; Wan, Yiqun

    2013-07-01

    A simple, rapid, sensitive and selective method for simultaneously determining 2-naphthoxyacetic acid (BNOA) and Indole-3-Acetic Acid (IAA) in mixtures has been developed using derivation synchronous fluorescence spectroscopy based on their synchronous fluorescence. The synchronous fluorescence spectra were obtained with Δλ = 100 nm in a pH 8.5 NaH2PO4-NaOH buffer solution, and the detected wavelengths of quantitative analysis were set at 239 nm for BNOA and 293 nm for IAA respectively. The over lapped fluorescence spectra were well separated by the synchronous derivative method. Under optimized conditions, the limits of detection (LOD) were 0.003 μg/mL for BNOA and 0.012 μg/mL for IAA. This method is simple and expeditious, and it has been successfully applied to the determination of 2-naphthoxyacetic acid and indole-3-acetic acid in fruit juice samples with satisfactory results. The samples were only filtrated through a 0.45 μm membrane filter, which was free from the tedious separation procedures. The obtaining recoveries were in the range of 83.88-87.43% for BNOA and 80.76-86.68% for IAA, and the relative standard deviations were all less than 5.0%. Statistical comparison of the results with high performance liquid chromatography Mass Spectrometry (HPLC-MS) method revealed good agreement and proved that there were no significant difference in the accuracy and precision between these two methods.

  20. Polymer nanopillar-gold arrays as surface-enhanced Raman spectroscopy substrate for the simultaneous detection of multiple genes.

    PubMed

    Picciolini, Silvia; Mehn, Dora; Morasso, Carlo; Vanna, Renzo; Bedoni, Marzia; Pellacani, Paola; Marchesini, Gerardo; Valsesia, Andrea; Prosperi, Davide; Tresoldi, Cristina; Ciceri, Fabio; Gramatica, Furio

    2014-10-28

    In our study, 2D nanopillar arrays with plasmonic crystal properties are optimized for surface-enhanced Raman spectroscopy (SERS) application and tested in a biochemical assay for the simultaneous detection of multiple genetic leukemia biomarkers. The special fabrication process combining soft lithography and plasma deposition techniques allows tailoring of the structural and chemical parameters of the crystal surfaces. In this way, it has been possible to tune the plasmonic resonance spectral position close to the excitation wavelength of the monochromatic laser light source in order to maximize the enhancing properties of the substrate. Samples are characterized by scanning electron microscopy and reflectance measurements and tested for SERS activity using malachite green. Besides, as the developed substrate had been prepared on a simple glass slide, SERS detection from the support side is also demonstrated. The optimized substrate is functionalized with thiol-modified capture oligonucleotides, and concentration-dependent signal of the target nucleotide is detected in a sandwich assay with labeled gold nanoparticles. Gold nanoparticles functionalized with different DNA and various Raman reporters are applied in a microarray-based assay recognizing a disease biomarker (Wilms tumor gene) and housekeeping gene expressions in the same time on spatially separated microspots. The multiplexing performance of the SERS-based bioassay is illustrated by distinguishing Raman dyes based on their complex spectral fingerprints.

  1. Simultaneous determination of 2-naphthoxyacetic acid and indole-3-acetic acid by first derivation synchronous fluorescence spectroscopy.

    PubMed

    Liu, Xiangxiang; Wan, Yiqun

    2013-07-01

    A simple, rapid, sensitive and selective method for simultaneously determining 2-naphthoxyacetic acid (BNOA) and Indole-3-Acetic Acid (IAA) in mixtures has been developed using derivation synchronous fluorescence spectroscopy based on their synchronous fluorescence. The synchronous fluorescence spectra were obtained with Δλ=100 nm in a pH 8.5 NaH2PO4-NaOH buffer solution, and the detected wavelengths of quantitative analysis were set at 239 nm for BNOA and 293 nm for IAA respectively. The over lapped fluorescence spectra were well separated by the synchronous derivative method. Under optimized conditions, the limits of detection (LOD) were 0.003 μg/mL for BNOA and 0.012 μg/mL for IAA. This method is simple and expeditious, and it has been successfully applied to the determination of 2-naphthoxyacetic acid and indole-3-acetic acid in fruit juice samples with satisfactory results. The samples were only filtrated through a 0.45 μm membrane filter, which was free from the tedious separation procedures. The obtaining recoveries were in the range of 83.88-87.43% for BNOA and 80.76-86.68% for IAA, and the relative standard deviations were all less than 5.0%. Statistical comparison of the results with high performance liquid chromatography Mass Spectrometry (HPLC-MS) method revealed good agreement and proved that there were no significant difference in the accuracy and precision between these two methods.

  2. Cerebral hemodynamic responses to seizure in the mouse brain: simultaneous near-infrared spectroscopy-electroencephalography study

    NASA Astrophysics Data System (ADS)

    Lee, Seungduk; Lee, Mina; Koh, Dalkwon; Kim, Beop-Min; Choi, Jee Hyun

    2010-05-01

    We applied near-infrared spectroscopy (NIRS) and electroencephalography (EEG) simultaneously on the mouse brain and investigated the hemodynamic response to epileptic episodes under pharmacologically driven seizure. γ-butyrolactone (GBL) and 4-aminopyridine (4-AP) were applied to induce absence and tonic-clonic seizures, respectively. The epileptic episodes were identified from the single-channel EEG, and the corresponding hemodynamic changes in different regions of the brain were characterized by multichannel frequency-domain NIRS. Our results are the following: (i) the oxyhemoglobin level increases in the case of GBL-treated mice but not 4-AP-treated mice compared to the predrug state; (ii) the dominant response to each absence seizure is a decrease in deoxyhemolobin; (iii) the phase shift between oxy- and deoxyhemoglobin reduces in GBL-treated mice but no 4-AP-treated mice; and (iv) the spatial correlation of hemodynamics increased significantly in 4-AP-treated mice but not in GBL-treated mice. Our results shows that spatiotemporal tracking of cerebral hemodynamics using NIRS can be successfully applied to the mouse brain in conjunction with electrophysiological recording, which will support the study of molecular, cellular, and network origin of neurovascular coupling in vivo.

  3. Simultaneous ground-based thermospheric wind measurements using Doppler asymmetric spatial heterodyne spectroscopy (DASH) and Fabry-Perot Interferometry

    NASA Astrophysics Data System (ADS)

    Englert, C. R.; Harlander, J. M.; Meriwether, J. W.; Brown, C. M.; Drob, D. P.; Emmert, J. T.; Castelaz, M.; Roesler, F. L.

    2011-12-01

    The concept of Doppler Asymmetric Spatial Heterodyne (DASH) instruments to measure upper atmospheric winds was initially published in 2006. The DASH approach is identical to the concept of Spatial Heterodyne Spectroscopy (SHS) except that one interferometer arm includes an additional fixed optical path offset, similar to the phase stepping Michelson technique which was used for the WINDII (Wind Imaging Interferometer) experiment. The advantages of DASH include having no moving parts, high sensitivity, and the ability to simultaneously observe multiple isolated emission lines, including a known light source for real time calibration. Since it was first proposed, the development of the DASH technique has progressed significantly. Major milestones include a proof of concept in the laboratory, the design, fabrication and test of a monolithic DASH interferometer for the thermospheric red line (O I 630nm), and initial ground based thermospheric wind measurements using this interferometer. To further increase the technical readiness level (TRL) of DASH for a future satellite instrument, we have conducted coordinated measurements with a DASH prototype and Fabry-Perot interferometer (FPI) from the Pisgah Astronomical Research Institute in North Carolina in the summer of 2011. We will present a comparison of the two experimental data sets and examine how they compare with the empirical horizontal wind model HWM-07.

  4. Fourier Transform-Plasmon Waveguide Spectroscopy: A Nondestructive Multifrequency Method for Simultaneously Determining Polymer Thickness and Apparent Index of Refraction

    SciTech Connect

    Bobbitt, Jonathan M; Weibel, Stephen C; Elshobaki, Moneim; Chaudhary, Sumit; Smith, Emily A

    2014-12-16

    Fourier transform (FT)-plasmon waveguide resonance (PWR) spectroscopy measures light reflectivity at a waveguide interface as the incident frequency and angle are scanned. Under conditions of total internal reflection, the reflected light intensity is attenuated when the incident frequency and angle satisfy conditions for exciting surface plasmon modes in the metal as well as guided modes within the waveguide. Expanding upon the concept of two-frequency surface plasmon resonance developed by Peterlinz and Georgiadis [ Opt. Commun. 1996, 130, 260], the apparent index of refraction and the thickness of a waveguide can be measured precisely and simultaneously by FT-PWR with an average percent relative error of 0.4%. Measuring reflectivity for a range of frequencies extends the analysis to a wide variety of sample compositions and thicknesses since frequencies with the maximum attenuation can be selected to optimize the analysis. Additionally, the ability to measure reflectivity curves with both p- and s-polarized light provides anisotropic indices of refraction. FT-PWR is demonstrated using polystyrene waveguides of varying thickness, and the validity of FT-PWR measurements are verified by comparing the results to data from profilometry and atomic force microscopy (AFM).

  5. Synchronous activity of two people's prefrontal cortices during a cooperative task measured by simultaneous near-infrared spectroscopy.

    PubMed

    Funane, Tsukasa; Kiguchi, Masashi; Atsumori, Hirokazu; Sato, Hiroki; Kubota, Kisou; Koizumi, Hideaki

    2011-07-01

    The brain activity during cooperation as a form of social process is studied. We investigate the relationship between coinstantaneous brain-activation signals of multiple participants and their cooperative-task performance. A wearable near-infrared spectroscopy (NIRS) system is used for simultaneously measuring the brain activities of two participants. Each pair of participants perform a cooperative task, and their relative changes in cerebral blood are measured with the NIRS system. As for the task, the participants are told to count 10 s in their mind after an auditory cue and press a button. They are also told to adjust the timing of their button presses to make them as synchronized as possible. Certain information, namely, the "intertime interval" between the two button presses of each participant pair and which of the participants was the faster, is fed back to the participants by a beep sound after each trial. When the spatiotemporal covariance between the activation patterns of the prefrontal cortices of each participant is higher, the intertime interval between their button-press times was shorter. This result suggests that the synchronized activation patterns of the two participants' brains are associated with their performance when they interact in a cooperative task.

  6. Fourier transform-plasmon waveguide spectroscopy: a nondestructive multifrequency method for simultaneously determining polymer thickness and apparent index of refraction.

    PubMed

    Bobbitt, Jonathan M; Weibel, Stephen C; Elshobaki, Moneim; Chaudhary, Sumit; Smith, Emily A

    2014-12-16

    Fourier transform (FT)-plasmon waveguide resonance (PWR) spectroscopy measures light reflectivity at a waveguide interface as the incident frequency and angle are scanned. Under conditions of total internal reflection, the reflected light intensity is attenuated when the incident frequency and angle satisfy conditions for exciting surface plasmon modes in the metal as well as guided modes within the waveguide. Expanding upon the concept of two-frequency surface plasmon resonance developed by Peterlinz and Georgiadis [Opt. Commun. 1996, 130, 260], the apparent index of refraction and the thickness of a waveguide can be measured precisely and simultaneously by FT-PWR with an average percent relative error of 0.4%. Measuring reflectivity for a range of frequencies extends the analysis to a wide variety of sample compositions and thicknesses since frequencies with the maximum attenuation can be selected to optimize the analysis. Additionally, the ability to measure reflectivity curves with both p- and s-polarized light provides anisotropic indices of refraction. FT-PWR is demonstrated using polystyrene waveguides of varying thickness, and the validity of FT-PWR measurements are verified by comparing the results to data from profilometry and atomic force microscopy (AFM).

  7. Synchronous activity of two people's prefrontal cortices during a cooperative task measured by simultaneous near-infrared spectroscopy

    NASA Astrophysics Data System (ADS)

    Funane, Tsukasa; Kiguchi, Masashi; Atsumori, Hirokazu; Sato, Hiroki; Kubota, Kisou; Koizumi, Hideaki

    2011-07-01

    The brain activity during cooperation as a form of social process is studied. We investigate the relationship between coinstantaneous brain-activation signals of multiple participants and their cooperative-task performance. A wearable near-infrared spectroscopy (NIRS) system is used for simultaneously measuring the brain activities of two participants. Each pair of participants perform a cooperative task, and their relative changes in cerebral blood are measured with the NIRS system. As for the task, the participants are told to count 10 s in their mind after an auditory cue and press a button. They are also told to adjust the timing of their button presses to make them as synchronized as possible. Certain information, namely, the ``intertime interval'' between the two button presses of each participant pair and which of the participants was the faster, is fed back to the participants by a beep sound after each trial. When the spatiotemporal covariance between the activation patterns of the prefrontal cortices of each participant is higher, the intertime interval between their button-press times was shorter. This result suggests that the synchronized activation patterns of the two participants' brains are associated with their performance when they interact in a cooperative task.

  8. Simultaneous monitoring of Staphylococcus aureus growth in a multi-parametric microfluidic platform using microscopy and impedance spectroscopy.

    PubMed

    Estrada-Leypon, O; Moya, A; Guimera, A; Gabriel, G; Agut, M; Sanchez, B; Borros, S

    2015-10-01

    We describe the design, construction, and characterization of a scalable microfluidic platform that allows continuous monitoring of biofilm proliferation under shear stress conditions. Compared to other previous end-point assay studies, our platform offers the advantages of integration into multiple environments allowing simultaneous optical microscopy and impedance spectroscopy measurements. In this work we report a multi-parametric sensor that can monitor the growth and activity of a biofilm. This was possible by combining two interdigitated microelectrodes (IDuEs), and punctual electrodes to measure dissolved oxygen, K+, Na+ and pH. The IDuE has been optimized to permit sensitive and reliable impedance monitoring of Staphylococcus aureus V329 growth with two- and four-electrode measurements. We distinguished structural and morphological changes on intact cellular specimens using four-electrode data modeling. We also detected antibiotic mediated effects using impedance. Results were confirmed by scanning electrode microscopy and fluorescence microscopy after live/dead cell staining. The bacitracin mediated effects detected with impedance prove that the approach described can be used for guiding the development of novel anti-biofilm agents to better address bacterial infection.

  9. Simultaneous fingerprint and high-wavenumber fiber-optic Raman spectroscopy improves in vivo diagnosis of esophageal squamous cell carcinoma at endoscopy

    PubMed Central

    Wang, Jianfeng; Lin, Kan; Zheng, Wei; Yu Ho, Khek; Teh, Ming; Guan Yeoh, Khay; Huang, Zhiwei

    2015-01-01

    This work aims to evaluate clinical value of a fiber-optic Raman spectroscopy technique developed for in vivo diagnosis of esophageal squamous cell carcinoma (ESCC) during clinical endoscopy. We have developed a rapid fiber-optic Raman endoscopic system capable of simultaneously acquiring both fingerprint (FP)(800–1800 cm−1) and high-wavenumber (HW)(2800–3600 cm−1) Raman spectra from esophageal tissue in vivo. A total of 1172 in vivo FP/HW Raman spectra were acquired from 48 esophageal patients undergoing endoscopic examination. The total Raman dataset was split into two parts: 80% for training; while 20% for testing. Partial least squares-discriminant analysis (PLS-DA) and leave-one patient-out, cross validation (LOPCV) were implemented on training dataset to develop diagnostic algorithms for tissue classification. PLS-DA-LOPCV shows that simultaneous FP/HW Raman spectroscopy on training dataset provides a diagnostic sensitivity of 97.0% and specificity of 97.4% for ESCC classification. Further, the diagnostic algorithm applied to the independent testing dataset based on simultaneous FP/HW Raman technique gives a predictive diagnostic sensitivity of 92.7% and specificity of 93.6% for ESCC identification, which is superior to either FP or HW Raman technique alone. This work demonstrates that the simultaneous FP/HW fiber-optic Raman spectroscopy technique improves real-time in vivo diagnosis of esophageal neoplasia at endoscopy. PMID:26243571

  10. Simultaneous fingerprint and high-wavenumber fiber-optic Raman spectroscopy improves in vivo diagnosis of esophageal squamous cell carcinoma at endoscopy

    NASA Astrophysics Data System (ADS)

    Wang, Jianfeng; Lin, Kan; Zheng, Wei; Yu Ho, Khek; Teh, Ming; Guan Yeoh, Khay; Huang, Zhiwei

    2015-08-01

    This work aims to evaluate clinical value of a fiber-optic Raman spectroscopy technique developed for in vivo diagnosis of esophageal squamous cell carcinoma (ESCC) during clinical endoscopy. We have developed a rapid fiber-optic Raman endoscopic system capable of simultaneously acquiring both fingerprint (FP)(800-1800 cm-1) and high-wavenumber (HW)(2800-3600 cm-1) Raman spectra from esophageal tissue in vivo. A total of 1172 in vivo FP/HW Raman spectra were acquired from 48 esophageal patients undergoing endoscopic examination. The total Raman dataset was split into two parts: 80% for training; while 20% for testing. Partial least squares-discriminant analysis (PLS-DA) and leave-one patient-out, cross validation (LOPCV) were implemented on training dataset to develop diagnostic algorithms for tissue classification. PLS-DA-LOPCV shows that simultaneous FP/HW Raman spectroscopy on training dataset provides a diagnostic sensitivity of 97.0% and specificity of 97.4% for ESCC classification. Further, the diagnostic algorithm applied to the independent testing dataset based on simultaneous FP/HW Raman technique gives a predictive diagnostic sensitivity of 92.7% and specificity of 93.6% for ESCC identification, which is superior to either FP or HW Raman technique alone. This work demonstrates that the simultaneous FP/HW fiber-optic Raman spectroscopy technique improves real-time in vivo diagnosis of esophageal neoplasia at endoscopy.

  11. Simultaneous Photometry and Spectroscopy of the Deeply Absorbing Polar MASTER OT J132104.04+560957.8

    NASA Astrophysics Data System (ADS)

    Hoyt, Taylor; Littlefield, Colin; Garnavich, Peter M.

    2016-01-01

    We present photometry and time-resolved spectroscopy of the suspected polar MASTER OT J132104.04+560957.8 (J1321) taken at the Large Binocular Telescope (LBT) simultaneously with the LBC camera and MODS spectrograph in binocular mode. Our V-band photometry confirmed a primary and secondary maximum first identified by Littlefield et al. In the spectra we see unusually deep Balmer and helium absorption features for about 10-15% of a 91 minute orbital period. The absorption lines first appear to the red of the emission peaks then shift bluewards, ultimately dominating the line profile at zero radial velocity. Towards the end of the absorption phase, weak absorption reappears to the blue of the emission lines. When the system is bright the spectra show a broadly-peaked continuum with a maximum around 500nm. We do not see absorption during the secondary bright red phase. Around the minima the continuum is blue and resembles a more typical polar spectrum with strong Balmer, neutral helium and ionized helium emission lines. The Doppler tomograms of J1321 are fuzzy and blobby and resemble those of the asynchronous polar BY Cam. The highly variable width of the secondary maximum remains a mystery along with the lack of a discernible irradiated secondary in the tomograms. We use our observations to constrain the properties of the white dwarf's magnetic field as well as the accretion flow structure. We also discuss evidence of J1321 being in a prolonged low-mass-transfer state in all observations prior to 2007.

  12. Simultaneous determination of CRP and D-dimer in human blood plasma samples with White Light Reflectance Spectroscopy.

    PubMed

    Koukouvinos, Georgios; Petrou, Panagiota; Misiakos, Konstantinos; Drygiannakis, Dimitris; Raptis, Ioannis; Stefanitsis, Gerasimos; Martini, Spyridoula; Nikita, Dimitra; Goustouridis, Dimitrios; Moser, Isabella; Jobst, Gerhard; Kakabakos, Sotirios

    2016-10-15

    A dual-analyte assay for the simultaneous determination of C-reactive protein (CRP) and D-dimer in human blood plasma based on a white light interference spectroscopy sensing platform is presented. Measurement is accomplished in real-time by scanning the sensing surface, on which distinct antibody areas have been created, with a reflection probe used both for illumination of the surface and collection of the reflected interference spectrum. The composition of the transducer, the sensing surface chemical activation and biofunctionalization procedures were optimized with respect to signal magnitude and repeatability. The assay format involved direct detection of CRP whereas for D-dimer a two-site immunoassay employing a biotinylated reporter antibody and reaction with streptavidin was selected. The assays were sensitive with detection limits of 25ng/mL for both analytes, precise with intra- and inter-assay CV values ranging from 3.6% to 7.7%, and from 4.8% to 9.5%, respectively, for both assays, and accurate with recovery values ranging from 88.5% to 108% for both analytes. Moreover, the values determined for the two analytes in 35 human plasma samples were in excellent agreement with those received for the same samples by standard diagnostic laboratory instrumentation employing commercial kits. The excellent agreement of the results supported the validity of the proposed system for clinical application for the detection of multiple analytes since it was demonstrated that up to seven antibody areas can be created on the sensing surface and successfully interrogated with the developed optical set-up.

  13. Simultaneous probing of bulk liquid phase and catalytic gas-liquid-solid interface under working conditions using attenuated total reflection infrared spectroscopy.

    PubMed

    Meemken, Fabian; Müller, Philipp; Hungerbühler, Konrad; Baiker, Alfons

    2014-08-01

    Design and performance of a reactor set-up for attenuated total reflection infrared (ATR-IR) spectroscopy suitable for simultaneous reaction monitoring of bulk liquid and catalytic solid-liquid-gas interfaces under working conditions are presented. As advancement of in situ spectroscopy an operando methodology for gas-liquid-solid reaction monitoring was developed that simultaneously combines catalytic activity and molecular level detection at the catalytically active site of the same sample. Semi-batch reactor conditions are achieved with the analytical set-up by implementing the ATR-IR flow-through cell in a recycle reactor system and integrating a specifically designed gas feeding system coupled with a bubble trap. By the use of only one spectrometer the design of the new ATR-IR reactor cell allows for simultaneous detection of the bulk liquid and the catalytic interface during the working reaction. Holding two internal reflection elements (IRE) the sample compartments of the horizontally movable cell are consecutively flushed with reaction solution and pneumatically actuated, rapid switching of the cell (<1 s) enables to quasi simultaneously follow the heterogeneously catalysed reaction at the catalytic interface on a catalyst-coated IRE and in the bulk liquid on a blank IRE. For a complex heterogeneous reaction, the asymmetric hydrogenation of 2,2,2-trifluoroacetophenone on chirally modified Pt catalyst the elucidation of catalytic activity/enantioselectivity coupled with simultaneous monitoring of the catalytic solid-liquid-gas interface is shown. Both catalytic activity and enantioselectivity are strongly dependent on the experimental conditions. The opportunity to gain improved understanding by coupling measurements of catalytic performance and spectroscopic detection is presented. In addition, the applicability of modulation excitation spectroscopy and phase-sensitive detection are demonstrated.

  14. Simultaneous fingerprint and high-wavenumber fiber-optic Raman spectroscopy enhances real-time in vivo diagnosis of adenomatous polyps during colonoscopy.

    PubMed

    Bergholt, Mads Sylvest; Lin, Kan; Wang, Jianfeng; Zheng, Wei; Xu, Hongzhi; Huang, Qingwen; Ren, Jian-Lin; Ho, Khek Yu; Teh, Ming; Srivastava, Supriya; Wong, Benjamin; Yeoh, Khay Guan; Huang, Zhiwei

    2016-04-01

    Colorectal cancer can be prevented if detected early (e.g., precancerous polyps-adenoma). Endoscopic differential diagnosis of hyperplastic polyps (that have little or no risk of malignant transformation) and adenomas (that have prominent malignant latency) remains an unambiguous clinical challenge. Raman spectroscopy is an optical vibrational technique capable of probing biomolecular changes of tissue associated with neoplastic transformation. This work aims to apply a fiber-optic simultaneous fingerprint (FP) and high wavenumber (HW) Raman spectroscopy technique for real-time in vivo assessment of adenomatous polyps during clinical colonoscopy. We have developed a fiber-optic Raman endoscopic technique capable of simultaneously acquiring both the FP (i.e., 800-1800 cm(-1)) and HW (i.e., 2800-3600 cm(-1)) Raman spectra from colorectal tissue subsurface (<200 µm) for real-time assessment of colorectal carcinogenesis. In vivo FP/HW Raman spectra were acquired from 50 patients with 17 colorectal polyps during clinical colonoscopy. Prominent Raman spectral differences (p < 0.001) were found between hyperplastic (n = 118 spectra), adenoma (n = 184 spectra) that could be attributed to changes in inter- and intra-cellular proteins, lipids, DNA and water structures and conformations. Simultaneous FP/HW Raman endoscopy provides a diagnostic sensitivity of 90.9% and specificity of 83.3% for differentiating adenoma from hyperplastic polyps, which is superior to either the FP or HW Raman technique alone. This study shows that simultaneous FP/HW Raman spectroscopy technique has the potential to be a clinically powerful tool for improving early diagnosis of adenomatous polyps in vivo during colonoscopic examination.

  15. Dynamics of asymmetric non-polymeric binary glass formers—A nuclear magnetic resonance and dielectric spectroscopy study

    SciTech Connect

    Pötzschner, B.; Mohamed, F.; Lichtinger, A.; Bock, D.; Rössler, E. A.

    2015-10-21

    We study a dynamically asymmetric binary glass former with the low-T{sub g} component m-tri-cresyl phosphate (m-TCP: T{sub g} = 206 K) and a spirobichroman derivative as a non-polymeric high-T{sub g} component (T{sub g} = 382 K) by means of {sup 1}H nuclear magnetic resonance (NMR), {sup 31}P NMR, and dielectric spectroscopy which allow component-selectively probing the dynamics. The entire concentration range is covered, and two main relaxation processes with two T{sub g} are identified, T{sub g1} and T{sub g2}. The slower one is attributed to the high-T{sub g} component (α{sub 1}-process), and the faster one is related to the m-TCP molecules (α{sub 2}-process). Yet, there are indications that a small fraction of m-TCP is associated also with the α{sub 1}-process. While the α{sub 1}-relaxation only weakly broadens upon adding m-TCP, the α{sub 2}-relaxation becomes extremely stretched leading to quasi-logarithmic correlation functions at low m-TCP concentrations—as probed by {sup 31}P NMR stimulated echo experiments. Frequency-temperature superposition does not apply for the α{sub 2}-process and it reflects an isotropic, liquid-like motion which is observed even below T{sub g1}, i.e., in the matrix of the arrested high-T{sub g} molecules. As proven by 2D {sup 31}P NMR, the corresponding dynamic heterogeneities are of transient nature, i.e., exchange occurs within the distribution G(lnτ{sub α2}). At T{sub g1} a crossover is found for the temperature dependence of (mean) τ{sub α2}(T) from non-Arrhenius above to Arrhenius below T{sub g1} which is attributed to intrinsic confinement effects. This “fragile-to-strong” transition also leads to a re-decrease of T{sub g2}(c{sub m−TCP}) at low concentration c{sub m−TCP}, i.e., a maximum is observed in T{sub g2}(c{sub m−TCP}) while T{sub g1}(c{sub m−TCP}) displays the well-known plasticizer effect. Although only non-polymeric components are involved, we re-discover essentially all features previously

  16. Dynamics of asymmetric non-polymeric binary glass formers—A nuclear magnetic resonance and dielectric spectroscopy study

    NASA Astrophysics Data System (ADS)

    Pötzschner, B.; Mohamed, F.; Lichtinger, A.; Bock, D.; Rössler, E. A.

    2015-10-01

    We study a dynamically asymmetric binary glass former with the low-Tg component m-tri-cresyl phosphate (m-TCP: Tg = 206 K) and a spirobichroman derivative as a non-polymeric high-Tg component (Tg = 382 K) by means of 1H nuclear magnetic resonance (NMR), 31P NMR, and dielectric spectroscopy which allow component-selectively probing the dynamics. The entire concentration range is covered, and two main relaxation processes with two Tg are identified, Tg1 and Tg2. The slower one is attributed to the high-Tg component (α1-process), and the faster one is related to the m-TCP molecules (α2-process). Yet, there are indications that a small fraction of m-TCP is associated also with the α1-process. While the α1-relaxation only weakly broadens upon adding m-TCP, the α2-relaxation becomes extremely stretched leading to quasi-logarithmic correlation functions at low m-TCP concentrations—as probed by 31P NMR stimulated echo experiments. Frequency-temperature superposition does not apply for the α2-process and it reflects an isotropic, liquid-like motion which is observed even below Tg1, i.e., in the matrix of the arrested high-Tg molecules. As proven by 2D 31P NMR, the corresponding dynamic heterogeneities are of transient nature, i.e., exchange occurs within the distribution G(lnτα2). At Tg1 a crossover is found for the temperature dependence of (mean) τα2(T) from non-Arrhenius above to Arrhenius below Tg1 which is attributed to intrinsic confinement effects. This "fragile-to-strong" transition also leads to a re-decrease of Tg2(cm-TCP) at low concentration cm-TCP, i.e., a maximum is observed in Tg2(cm-TCP) while Tg1(cm-TCP) displays the well-known plasticizer effect. Although only non-polymeric components are involved, we re-discover essentially all features previously reported for polymer-plasticizer systems.

  17. The Mn4Ca photosynthetic water-oxidation catalyst studied by simultaneous X-ray spectroscopy and crystallography using an X-ray free-electron laser

    PubMed Central

    Tran, Rosalie; Kern, Jan; Hattne, Johan; Koroidov, Sergey; Hellmich, Julia; Alonso-Mori, Roberto; Sauter, Nicholas K.; Bergmann, Uwe; Messinger, Johannes; Zouni, Athina; Yano, Junko; Yachandra, Vittal K.

    2014-01-01

    The structure of photosystem II and the catalytic intermediate states of the Mn4CaO5 cluster involved in water oxidation have been studied intensively over the past several years. An understanding of the sequential chemistry of light absorption and the mechanism of water oxidation, however, requires a new approach beyond the conventional steady-state crystallography and X-ray spectroscopy at cryogenic temperatures. In this report, we present the preliminary progress using an X-ray free-electron laser to determine simultaneously the light-induced protein dynamics via crystallography and the local chemistry that occurs at the catalytic centre using X-ray spectroscopy under functional conditions at room temperature. PMID:24914152

  18. Solid state {sup 31}P NMR study of phosphonate binding sites in guanidine-functionalized, molecular imprinted silica xerogels

    SciTech Connect

    Sasaki, D.Y.; Alam, T.D.

    2000-01-03

    Phosphonate binding sites in guanidine and ammonium surface-functionalized silica xerogels were prepared via the molecular imprinting technique and characterized using solid state {sup 31}P MAS NMR. One-point, two-point, and non-specific host-guest interactions between phenylphosphonic acid (PPA) and the functionalized gels were distinguished by characteristic chemical shifts of the observed absorption peaks. Using solid state as well as solution phase NMR analyses, absorptions observed at 15.5 ppm and 6.5 ppm were identified as resulting from the 1:1 (one-point) and 2:1 (two-point) guanidine to phosphonate interactions, respectively. Similar absorptions were observed with the ammonium functionalized gels. By examining the host-guest interactions within the gels, the efficiency of the molecular imprinting procedure with regard to the functional monomer-to-template interaction could be readily assessed. Template removal followed by substrate adsorption studies conducted on the guanidine functionalized gels provided a method to evaluate the binding characteristics of the receptor sites to a phosphonate substrate. During these experiments, {sup 29}Si and {sup 31}P MAS NMR acted as diagnostic monitors to identify structural changes occurring in the gel matrix and at the receptor site from solvent mediated processes.

  19. Combining solid-state and solution-state 31P NMR to study in vivo phosphorus metabolism.

    PubMed Central

    Cholli, A L; Yamane, T; Jelinski, L W

    1985-01-01

    Otherwise unavailable information concerning the distribution of phosphorylated compounds in biological systems is obtained by a combined solid-state/solution-state NMR approach, illustrated here for oocytes from Rana pipiens. General methodology is developed, and further extensions are proposed. The following conclusions pertain to the specific system under examination. (i) Nucleoside phosphates can be observed by magic-angle sample spinning of the lyophilized material. (ii) The solid-state NMR technique of dipolar decoupling provides no additional resolution of the phospholipid and phosphoprotein components of the yolk. However, cellular death produces sufficient pH changes to cause the phospholipid and protein phosphate peaks to become resolvable. The concentration of nucleoside phosphates also decreases. (iii) The phospholipid and phosphoprotein components are shown by computer simulation to be present in a ratio of 40:60, respectively. (iv) The amounts of inorganic phosphate, nucleoside phosphates, and sugar phosphates are determined by solution-state NMR observation of the perchloric acid extract of the oocytes. PMID:3871524

  20. {sup 31}P NMR analysis of coal moieties bearing -OH, -NH, and -SH functions. Final technical report

    SciTech Connect

    Verkade, J.G.

    1991-08-31

    NMR reagents for the speciation and quantitation of labile-hydrogen functional groups and sulfur groups in coal ligands have been synthesized and evaluated. These reagents, which contain the NMR-active nuclei {sup 31}p, {sup 119}Sn or {sup 195}pt, were designed to possess improved chemical shift resolution over reagents reported in the literature. Our efforts were successful in the case of the new {sup 31}p and {sup 119}Sn reagents we developed, but the {sup 195}pt work on sulfur groups was only partially successful in as much as the grant came to a close and was not renewed. Our success with {sup 31}P and {sup 119}Sn NMR reagents came to the attention of Amoco and they have recently expressed interest in further supporting that work. A further measure of the success of our efforts can be seen in the nine publications supported by this grant which are cited in the reference list.

  1. 31P NMR Relaxation of Cortical Bone Mineral at Multiple Magnetic Field Strengths and Levels of Demineralization

    PubMed Central

    Seifert, Alan C.; Wright, Alexander C.; Wehrli, Suzanne L.; Ong, Henry H.; Li, Cheng; Wehrli, Felix W.

    2013-01-01

    Purpose Recent work has shown that solid-state 1H and 31P MRI can provide detailed insight into bone matrix and mineral properties, thereby potentially enabling differentiation of osteoporosis from osteomalacia. However, 31P MRI of bone mineral is hampered by unfavorable relaxation properties. Hence, accurate knowledge of these properties is critical to optimizing MRI of bone phosphorus. Methods In this work, 31P MRI signal-to-noise ratio (SNR) was predicted on the basis of T1 and T2* (effective transverse relaxation time) measured in lamb bone at six field strengths (1.5 – 11.7 T) and subsequently verified by 3-D ultra-short echo-time and zero echo-time imaging. Further, T1 was measured in deuterium-exchanged bone and partially demineralized bone. Results 31P T2* was found to decrease from 220.3 ± 4.3 μs to 98.0 ± 1.4 μs from 1.5 to 11.7 T, and T1 to increase from 12.8 ± 0.5 s to 97.3 ± 6.4 s. Deuteron substitution of exchangeable water showed that 76% of the 31P longitudinal relaxation rate is due to 1H-31P dipolar interactions. Lastly, hypomineralization was found to decrease T1, which may have implications for 31P MRI based mineralization density quantification. Conclusion Despite the steep decrease in the T2*/T1 ratio, SNR should increase with field strength as Bo0.4 for sample-dominated noise and as Bo1.1 for coil-dominated noise. This was confirmed by imaging experiments. PMID:23505120

  2. Simultaneous assessment of pulsating and total blood in inflammatory skin lesions using functional diffuse reflectance spectroscopy in the visible range.

    PubMed

    Seo, InSeok; Bargo, Paulo R; Kollias, Nikiforos

    2010-01-01

    We present a simple and cost-effective optical technique for the simultaneous assessment of pulsating and total blood noninvasively in an inflammatory skin lesion. Acquisitions of diffuse reflectance spectra in the visible range at 6 Hz are used to trace the oscillating components of reflectance. Measurements on erythematous lesions from a UV insult show slow changing signal at about 0.1 Hz and heart-driven regular oscillations at about 1 Hz simultaneously. The results demonstrate the potential of the technique in monitoring both pulsating and steady components of the blood in inflammatory lesions of the skin.

  3. Hemodynamic and Electrophysiological Connectivity in the Language System: Simultaneous Near-Infrared Spectroscopy and Electrocorticography Recordings during Cortical Stimulation

    ERIC Educational Resources Information Center

    Sato, Yosuke; Oishi, Makoto; Fukuda, Masafumi; Fujii, Yukihiko

    2012-01-01

    We applied near-infrared spectroscopy (NIRS) and electrocorticography (ECoG) recordings during cortical stimulation to a temporal lobe epilepsy patient who underwent subdural electrode implantation. Using NIRS, changes in blood concentrations of oxyhemoglobin (HbO[subscript 2]) and deoxyhemoglobin (HbR) during cortical stimulation of the left…

  4. On the performance of multiway methods for simultaneous quantification of two fluoroquinolones in urine samples by fluorescence spectroscopy and second-order calibration strategies

    NASA Astrophysics Data System (ADS)

    Vosough, Maryam; Eshlaghi, Sara Noroozi; Zadmard, Reza

    2015-02-01

    In the present work, the analytical performance of three multi-way algorithms has been evaluated. The proposed analytical problem was the simultaneous determination of moxifloxacin and ciprofloxacin in human urine samples using fluorescence spectroscopy. Parallel factor analysis (PARAFAC), self-weighted alternating trilinear decomposition (SWATLD) and unfolded partial least squares combined with the residual bilinearization procedure (U-PLS/RBL) have been compared, regarding their ability to solve the proposed problem. In this study, "second-order advantage" was also exploited for the mentioned algorithms through different calibration strategies. The three-way data was obtained via fluorescence spectroscopy, so that excitation-emission matrices (EEM) of the samples were recorded as the analytical signals. The accuracy and precision of each individual algorithm for analyzing the drugs in urine samples were compared using root mean square error of prediction (RMSEP), recovery and elliptical joint confidence region (EJCR) plots. The results revealed that each of the three algorithms could be applied for determination of moxifloxacin and ciprofloxacin, despite different EEM subsets and calibration strategies. However, better analytical performances were observed through PARAFAC and U-PLS/RBL modeling for MOX and CIP, respectively. So, by coupling the multi-way decomposition algorithms with fluorescence spectroscopy, a main part of preliminary sample preparation steps can be eliminated and experimental procedure might be significantly simplified, while achieving desirable analytical performance.

  5. Feasibility of the Simultaneous Determination of Monomer Concentrations and Particle Size in Emulsion Polymerization Using in Situ Raman Spectroscopy

    PubMed Central

    2015-01-01

    An immersion Raman probe was used in emulsion copolymerization reactions to measure monomer concentrations and particle sizes. Quantitative determination of monomer concentrations is feasible in two-monomer copolymerizations, but only the overall conversion could be measured by Raman spectroscopy in a four-monomer copolymerization. The feasibility of measuring monomer conversion and particle size was established using partial least-squares (PLS) calibration models. A simplified theoretical framework for the measurement of particle sizes based on photon scattering is presented, based on the elastic-sphere-vibration and surface-tension models. PMID:26900256

  6. Simultaneous determination of pseudoephedrine hydrochloride, chlorpheniramine maleate, and dextromethorphan hydrobromide by second-derivative photodiode array spectroscopy.

    PubMed

    Murtha, J L; Julian, T N; Radebaugh, G W

    1988-08-01

    The simultaneous determination of the active ingredients in multicomponent pharmaceutical products normally requires the use of a separation technique, such as HPLC or GC, followed by quantitation. Presented here is a rapid, validated, analytical method that does not require prior separation for the simultaneous determination of three drugs, pseudoephedrine hydrochloride, chlorpheniramine maleate, and dextromethorphan hydrobromide, in a tablet formulation. A diode array spectrophotometer, capable of multicomponent analysis, was used for the quantitation. The utility of this method was demonstrated in two ways: the analysis of a chewable pediatric tablet (formulation CP) containing 7.5 mg of pseudoephedrine hydrochloride, 0.5 mg of chlorpheniramine maleate, and 2.5 mg of dextromethorphan hydrobromide, and the dissolution analysis of a hydroxypropyl methylcellulose-based sustained-release tablet (formulation SR) containing 120 mg of pseudoephedrine hydrochloride, 8 mg of chlorpheniramine maleate, and 60 mg of dextromethorphan hydrobromide. The sensitivity of this assay is 7.5 micrograms/mL for pseudoephedrine hydrochloride, 1.0 micrograms/mL for chlorpheniramine maleate, and 5.0 micrograms/mL for dextromethorphan hydrobromide, using the second-derivative spectra of the absorbance with respect to wavelength. Determinations were made in 0.1 M sodium acetate buffer at pH 5.0 using a 1-cm quartz cell. Absorbance spectra, and their first and second derivatives, from 240 to 300 nm were used for the determination. The results obtained by this method compared favorably with the results obtained by a validated HPLC method.

  7. Efficient Resonance Assignment of Proteins in MAS NMR by Simultaneous Intra- and Inter-residue 3D Correlation Spectroscopy

    PubMed Central

    Daviso, Eugenio; Eddy, Matthew T.; Andreas, Loren B.; Griffin, Robert G.; Herzfeld, Judith

    2013-01-01

    Resonance assignment is the first step in NMR structure determination. For magic angle spinning NMR, this is typically achieved with a set of heteronuclear correlation experiments (NCaCX, NCOCX, CONCa) that utilize SPECIFIC-CP 15N-13C transfers. However, the SPECIFIC-CP transfer efficiency is often compromised by molecular dynamics and probe performance. Here we show that one-bond ZF-TEDOR 15N-13C transfers provide simultaneous NCO and NCa transfers with at least as much sensitivity as SPECIFIC-CP for some non-crystalline samples. Furthermore, a 3D TEDOR-CC experiment provides heteronuclear sidechains correlations and robustness with respect to proton decoupling and radiofrequency power instabilities. We demonstrate transfer efficiencies and connectivities by application of 3D ZF-TEDOR-DARR to a model microcrystalline protein, GB1, and a less ideal system, GvpA in intact gas vesicles. PMID:23334347

  8. Simultaneous Analysis of Major Coenzymes of Cellular Redox Reactions and Energy Using ex Vivo (1)H NMR Spectroscopy.

    PubMed

    Nagana Gowda, G A; Abell, Lauren; Lee, Chi Fung; Tian, Rong; Raftery, Daniel

    2016-05-03

    Coenzymes of cellular redox reactions and cellular energy mediate biochemical reactions fundamental to the functioning of all living cells. Despite their immense interest, no simple method exists to gain insights into their cellular concentrations in a single step. We show that a simple (1)H NMR experiment can simultaneously measure oxidized and reduced forms of nicotinamide adenine dinucleotide (NAD(+) and NADH), oxidized and reduced forms of nicotinamide adenine dinucleotide phosphate (NADP(+) and NADPH), and adenosine triphosphate (ATP) and its precursors, adenosine diphosphate (ADP) and adenosine monophosphate (AMP), using mouse heart, kidney, brain, liver, and skeletal muscle tissue extracts as examples. Combining 1D/2D NMR experiments, chemical shift libraries, and authentic compound data, reliable peak identities for these coenzymes have been established. To assess this methodology, cardiac NADH and NAD(+) ratios/pool sizes were measured using mouse models with a cardiac-specific knockout of the mitochondrial Complex I Ndufs4 gene (cKO) and cardiac-specific overexpression of nicotinamide phosphoribosyltransferase (cNAMPT) as examples. Sensitivity of NAD(+) and NADH to cKO or cNAMPT was observed, as anticipated. Time-dependent investigations showed that the levels of NADH and NADPH diminish by up to ∼50% within 24 h; concomitantly, NAD(+) and NADP(+) increase proportionately; however, degassing the sample and flushing the sample tubes with helium gas halted such changes. The analysis protocol along with the annotated characteristic fingerprints for each coenzyme is provided for easy identification and absolute quantification using a single internal reference for routine use. The ability to visualize the ubiquitous coenzymes fundamental to cellular functions, simultaneously and reliably, offers a new avenue to interrogate the mechanistic details of cellular function in health and disease.

  9. Simultaneous Analysis of Major Coenzymes of Cellular Redox Reactions and Energy Using ex Vivo 1H NMR Spectroscopy

    PubMed Central

    2016-01-01

    Coenzymes of cellular redox reactions and cellular energy mediate biochemical reactions fundamental to the functioning of all living cells. Despite their immense interest, no simple method exists to gain insights into their cellular concentrations in a single step. We show that a simple 1H NMR experiment can simultaneously measure oxidized and reduced forms of nicotinamide adenine dinucleotide (NAD+ and NADH), oxidized and reduced forms of nicotinamide adenine dinucleotide phosphate (NADP+ and NADPH), and adenosine triphosphate (ATP) and its precursors, adenosine diphosphate (ADP) and adenosine monophosphate (AMP), using mouse heart, kidney, brain, liver, and skeletal muscle tissue extracts as examples. Combining 1D/2D NMR experiments, chemical shift libraries, and authentic compound data, reliable peak identities for these coenzymes have been established. To assess this methodology, cardiac NADH and NAD+ ratios/pool sizes were measured using mouse models with a cardiac-specific knockout of the mitochondrial Complex I Ndufs4 gene (cKO) and cardiac-specific overexpression of nicotinamide phosphoribosyltransferase (cNAMPT) as examples. Sensitivity of NAD+ and NADH to cKO or cNAMPT was observed, as anticipated. Time-dependent investigations showed that the levels of NADH and NADPH diminish by up to ∼50% within 24 h; concomitantly, NAD+ and NADP+ increase proportionately; however, degassing the sample and flushing the sample tubes with helium gas halted such changes. The analysis protocol along with the annotated characteristic fingerprints for each coenzyme is provided for easy identification and absolute quantification using a single internal reference for routine use. The ability to visualize the ubiquitous coenzymes fundamental to cellular functions, simultaneously and reliably, offers a new avenue to interrogate the mechanistic details of cellular function in health and disease. PMID:27043450

  10. Development and analytical validation of a screening method for simultaneous detection of five adulterants in raw milk using mid-infrared spectroscopy and PLS-DA.

    PubMed

    Botelho, Bruno G; Reis, Nádia; Oliveira, Leandro S; Sena, Marcelo M

    2015-08-15

    This paper proposed a new screening method for the simultaneous detection of five common adulterants in raw cow milk by using attenuated total reflectance (ATR) mid infrared spectroscopy and multivariate supervised classification (partial least squares discrimination analysis - PLSDA). The method was able to detect the presence of the adulterants water, starch, sodium citrate, formaldehyde and sucrose in milk samples containing from one up to five of these analytes, in the range of 0.5-10% w/v. A multivariate qualitative validation was performed, estimating specific figures of merit, such as false positive and false negative rates, selectivity, specificity and efficiency rates, accordance and concordance. The proposed method does not need any sample pretreatment, requires a small amount of sample (30 μL), is fast and simple, being suitable for the control of raw milk in a dairy industry or for the quality inspection of commercialized milk.

  11. Open-path quantum cascade laser-based system for simultaneous remote sensing of methane, nitrous oxide, and water vapor using chirped-pulse differential optical absorption spectroscopy

    NASA Astrophysics Data System (ADS)

    Castillo, Paulo; Diaz, Adrian; Thomas, Benjamin; Gross, Barry; Moshary, Fred

    2015-10-01

    Methane and Nitrous Oxide are long-lived greenhouse gases in the atmosphere with significant global warming effects. We report on application of chirped-pulsed quantum cascade lasers (QCLs) to simultaneous measurements of these trace gases in both open-path fence-line and backscatter systems. The intra-pulse thermal frequency chip in a QCL can be time resolved and calibrated to allow for high resolution differential optical absorption spectroscopy over the spectral window of the chip, which for a DFB-QCL can be reach ~2cm-1 for a 500 nsec pulse. The spectral line-shape of the output from these lasers are highly stable from pulse to pulse over long period of time (> 1 day), and the system does not require frequent calibrations.

  12. Note: application of a pixel-array area detector to simultaneous single crystal X-ray diffraction and X-ray absorption spectroscopy measurements.

    PubMed

    Sun, Cheng-Jun; Zhang, Bangmin; Brewe, Dale L; Chen, Jing-Sheng; Chow, G M; Venkatesan, T; Heald, Steve M

    2014-04-01

    X-ray diffraction (XRD) and X-ray absorption spectroscopy (XAS) are two main x-ray techniques in synchrotron radiation facilities. In this Note, we present an experimental setup capable of performing simultaneous XRD and XAS measurements by the application of a pixel-array area detector. For XRD, the momentum transfer in specular diffraction was measured by scanning the X-ray energy with fixed incoming and outgoing x-ray angles. By selecting a small fixed region of the detector to collect the XRD signal, the rest of the area was available for collecting the x-ray fluorescence for XAS measurements. The simultaneous measurement of XRD and X-ray absorption near edge structure for Pr0.67Sr0.33MnO3 film was demonstrated as a proof of principle for future time-resolved pump-probe measurements. A static sample makes it easy to maintain an accurate overlap of the X-ray spot and laser pump beam.

  13. Solid-state /sup 13/C nuclear magnetic resonance spectroscopy of simultaneously metabolized acetate and phenol in a soil Pseudomonas sp

    SciTech Connect

    Heiman, A.S.; Copper, W.T.

    1987-01-01

    An investigation was made of the concentration-dependent primary and secondary substrate relationships in the simultaneous metabolism of the ubiquitous pollutant phenol and the naturally occurring substrate acetate by a Pseudomonas sp. soil isolate capable of utilizing either substance as a sole source of carbon and energy. In addition to conventional analytical techniques, solid-state /sup 13/C nuclear magnetic resonance spectroscopy was used to follow the cellular distribution of (1-/sup 13/C)acetate in the presence of unlabeled phenol. These results suggest that, when phenol is present as the primary substrate, acetate is preferentially shuttled into fatty acyl chain synthesis, whereas phenol carbon is funnelled into the tricarboxylic acid cycle. Thus, simultaneous use of a xenobiotic compound and a natural substrate apparently does occur, and the relative concentrations of the two substrates do influence the rate and manner in which the compounds are utilized. These results also demonstrate the unique advantage of using solid-state nuclear magnetic resonance techniques combined with /sup 13/C labeling of specific sites in substrates when doing microbial degradation studies. In this work, the entire cellular biomass was examined directly without extensive extraction, fractionation, or isolation of subcellular units; thus, there is no uncertainty about chemical alteration of substrate metabolites as a result of these often harsh treatments.

  14. Combining Electrochemical Impedance Spectroscopy and Surface Plasmon Resonance into one Simultaneous Read-Out System for the Detection of Surface Interactions

    PubMed Central

    Vandenryt, Thijs; Pohl, Andrea; van Grinsven, Bart; Thoelen, Ronald; De Ceuninck, Ward; Wagner, Patrick; Opitz, Jörg

    2013-01-01

    In this article we describe the integration of impedance spectroscopy (EIS) and surface plasmon resonance (SPR) into one surface analytic device. A polydimethylsiloxane (PDMS) flow cell is created, matching the dimensions of a commercially available sensor chip used for SPR measurements. This flow cell allowed simultaneous measurements between an EIS and a SPR setup. After a successful integration, a proof of principle study was conducted to investigate any signs of interference between the two systems during a measurement. The flow cell was rinsed with 10 mM Tris-HCl and 1× PBS buffer in an alternating manner, while impedance and shifts of the resonance angle were monitored. After achieving a successful proof of principle, a usability test was conducted. It was assessed whether simultaneous detection occurred when: (i) Protein A is adsorbed to the gold surface of the chip; (ii) The non-occupied zone is blocked with BSA molecules and (iii) IgG1 is bound to the Protein A. The results indicate a successful merge between SPR and EIS. PMID:24172282

  15. Movement-related cortical activation with voluntary pinch task: simultaneous monitoring of near-infrared spectroscopy signals and movement-related cortical potentials

    NASA Astrophysics Data System (ADS)

    Sato, Yosuke; Fukuda, Masafumi; Oishi, Makoto; Fujii, Yukihiko

    2012-07-01

    This study was designed to evaluate hemodynamic and electrophysiological motor cortex responses to voluntary finger pinching in humans, with simultaneous recording of near-infrared spectroscopy (NIRS) signals and movement-related cortical potentials (MRCP). Six healthy, right-handed subjects performed 100 trials of voluntary right-thumb index-finger pinching with about a 10-second interval at their own pace. Throughout the session, 48 regions over the bilateral motor cortex were assessed by NIRS, while MRCP and electromyogram (EMG) were simultaneously monitored. MRCP started 1536+/-58 ms before EMG onset and peaked 127+/-24 ms after EMG onset. NIRS data showed bilateral prefrontal cortex at 0.5+/-0.1 s before EMG onset and bilateral dorsal premotor cortex activations at 0.6+/-0.1 s before EMG onset. The hand area of the sensorimotor cortex was activated left-dominantly, seen obviously peaked at 3.7+/-0.2 s after EMG onset. The comparison between MRCP and NIRS results raised the possibility that the vascular response to neural activity occurs within 4 s with a voluntary pinch task. These results indicate that our technique allows detailed study of the motor control. Our method is a promising strategy for event-related motor control and neurovascular coupling studies.

  16. Preliminary study of an offline simultaneous determination of metoprolol tartrate and hydrochlorothiazide in powders and tablets by reflectance near-infrared spectroscopy.

    PubMed

    Vranic, Branko Z; Vandamme, Thierry F

    2015-01-01

    A preliminary study of the feasibility of using near-infrared spectroscopy (NIRS) for the offline simultaneous determination of metoprolol tartrate (MTP) and hydrochlorothiazide (HTZ) in powders and tablets has been carried out. An industrial tableting process was simulated using an instrumented tablet press replicator - Presster™. Conventional reference analytics were replaced with gravimetric analysis. The NIRS models for powder and tablet analysis were developed using 55 samples, and tested on 80 independent samples. Powder mixture components were weighed in glass vials to collect reference values, mixed and manually transferred to a tablet press replicator and compacted to form tablets. NIRS calibration models were developed using spectral and gravimetric reference data. The two model drugs were simultaneously quantified exhibiting root mean-squared error of prediction (RMSEP) of 1.69 and 1.31 mg for HTZ powder and tablet samples, respectively, and RMSEP of 3.15 and 3.00 mg for MTP powder and tablet samples, respectively. NIRS analysis of MTP and HTZ in powder and tablet form has not been reported elsewhere.

  17. Evaluation of photoacoustic infrared spectroscopy for simultaneous measurement of N2 O and CO2 gas concentrations and fluxes at the soil surface.

    PubMed

    Iqbal, Javed; Castellano, Michael J; Parkin, Timothy B

    2013-01-01

    Simultaneous measurement of N2 O and CO2 flux at the soil surface with photoacoustic infrared spectroscopy (PAS) is gaining popularity due to portability, low maintenance, and ease-of-operation. However, the ability of PAS to measure N2 O with accuracy and precision similar to gas chromatography (GC) is uncertain due to overlap in N2 O, CO2 , and H2 O absorbance spectra combined with the large range in analyte concentrations. We tested the ability of six PAS units to simultaneously measure N2 O and CO2 gas concentrations and fluxes with accuracy and precision similar to two GC units. We also evaluated H2 O vapor and CO2 interferences with N2 O measurement. The accuracy and precision of standard gas concentration measurements with PAS and GC were similar. High water vapor (~26 600 ppm) and CO2 concentrations (~4500 ppm) did not interfere with N2 O measurement across the concentration range typically observed in static flux chambers at the soil surface (~0.5-3.0 ppm N2 O). On average, N2 O fluxes measured with the six PAS were 4.7% higher than one GC and 9.9% lower than the second GC.

  18. Elemental and molecular analysis of metal containing biomolecules using laser induced breakdown spectroscopy and sonic spray ionization mass spectrometry: A step towards full integration and simultaneous analysis

    NASA Astrophysics Data System (ADS)

    Marmatakis, Konstantinos; Pergantis, Spiros A.; Anglos, Demetrios

    2016-12-01

    A novel methodology is proposed that combines sonic spray ionization (SSI) mass spectrometry (MS) with laser induced breakdown spectroscopy (LIBS) for analyzing metal-containing biomolecules and complexes. Focusing pulses from a nanosecond laser (Nd:YAG, λ = 1064 nm) in the microdroplet ensemble produced by a pneumatic nebulizer yielded LIBS spectra that enabled highly sensitive detection of several metal ions in aqueous and aqueous methanolic solutions. Based on the calibration curve method, LOD values at the ng/mL level were achieved for Ca (15 ng/mL), Ba (27 ng/mL), Cu (67 ng/mL) and Fe (650 ng/mL) with accuracy > 90%. LIBS measurements were performed for the first time on aerosols of solutions of known biomolecules such as superoxide dismutase and alpha-lactalbumin, which led to the reliable determination of the concentration of Cu and Ca, respectively, both in the range of a few μg/mL. In parallel, the relative molecular mass of the metalloproteins was determined by separate SSI-MS measurements performed using an identical pneumatic nebulizer based sample introduction system. This is a first step towards the ultimate aim of integrating the two analytical techniques by use of a single pneumatic nebulization system for simultaneous sample introduction for both LIBS and SSI-MS. Such a system is expected to greatly enhance our capabilities to simultaneously acquire molecular and atomic data.

  19. Note: Application of a pixel-array area detector to simultaneous single crystal x-ray diffraction and x-ray absorption spectroscopy measurements

    SciTech Connect

    Sun, Cheng-Jun Brewe, Dale L.; Heald, Steve M.; Zhang, Bangmin; Chen, Jing-Sheng; Chow, G. M.; Venkatesan, T.

    2014-04-15

    X-ray diffraction (XRD) and X-ray absorption spectroscopy (XAS) are two main x-ray techniques in synchrotron radiation facilities. In this Note, we present an experimental setup capable of performing simultaneous XRD and XAS measurements by the application of a pixel-array area detector. For XRD, the momentum transfer in specular diffraction was measured by scanning the X-ray energy with fixed incoming and outgoing x-ray angles. By selecting a small fixed region of the detector to collect the XRD signal, the rest of the area was available for collecting the x-ray fluorescence for XAS measurements. The simultaneous measurement of XRD and X-ray absorption near edge structure for Pr{sub 0.67}Sr{sub 0.33}MnO{sub 3} film was demonstrated as a proof of principle for future time-resolved pump-probe measurements. A static sample makes it easy to maintain an accurate overlap of the X-ray spot and laser pump beam.

  20. Simultaneous observation of free and defect-bound excitons in CH3NH3PbI3 using four-wave mixing spectroscopy

    PubMed Central

    March, Samuel A.; Clegg, Charlotte; Riley, Drew B.; Webber, Daniel; Hill, Ian G.; Hall, Kimberley C.

    2016-01-01

    Solar cells incorporating organic-inorganic perovskite, which may be fabricated using low-cost solution-based processing, have witnessed a dramatic rise in efficiencies yet their fundamental photophysical properties are not well understood. The exciton binding energy, central to the charge collection process, has been the subject of considerable controversy due to subtleties in extracting it from conventional linear spectroscopy techniques due to strong broadening tied to disorder. Here we report the simultaneous observation of free and defect-bound excitons in CH3NH3PbI3 films using four-wave mixing (FWM) spectroscopy. Due to the high sensitivity of FWM to excitons, tied to their longer coherence decay times than unbound electron- hole pairs, we show that the exciton resonance energies can be directly observed from the nonlinear optical spectra. Our results indicate low-temperature binding energies of 13 meV (29 meV) for the free (defect-bound) exciton, with the 16 meV localization energy for excitons attributed to binding to point defects. Our findings shed light on the wide range of binding energies (2–55 meV) reported in recent years. PMID:27974815

  1. Simultaneous observation of free and defect-bound excitons in CH3NH3PbI3 using four-wave mixing spectroscopy.

    PubMed

    March, Samuel A; Clegg, Charlotte; Riley, Drew B; Webber, Daniel; Hill, Ian G; Hall, Kimberley C

    2016-12-15

    Solar cells incorporating organic-inorganic perovskite, which may be fabricated using low-cost solution-based processing, have witnessed a dramatic rise in efficiencies yet their fundamental photophysical properties are not well understood. The exciton binding energy, central to the charge collection process, has been the subject of considerable controversy due to subtleties in extracting it from conventional linear spectroscopy techniques due to strong broadening tied to disorder. Here we report the simultaneous observation of free and defect-bound excitons in CH3NH3PbI3 films using four-wave mixing (FWM) spectroscopy. Due to the high sensitivity of FWM to excitons, tied to their longer coherence decay times than unbound electron- hole pairs, we show that the exciton resonance energies can be directly observed from the nonlinear optical spectra. Our results indicate low-temperature binding energies of 13 meV (29 meV) for the free (defect-bound) exciton, with the 16 meV localization energy for excitons attributed to binding to point defects. Our findings shed light on the wide range of binding energies (2-55 meV) reported in recent years.

  2. Rapid and simultaneous determination of essential minerals and trace elements in human milk by improved flame atomic absorption spectroscopy (FAAS) with microwave digestion.

    PubMed

    Luo, Yang; Zhang, Bo; Chen, Ming; Wang, Jue; Zhang, Xue; Gao, Wei-Yin; Huang, Jun-Fu; Fu, Wei-Ling

    2010-09-08

    A method for the simultaneous and economical determination of many trace elements in human milk is developed. Two multi-element hollow cathode lamps (HCLs) were used instead of single-element HCLs to improve the sample throughput of flame atomic absorption spectroscopy (FAAS). The microwave digestion of milk is optimized prior to detection, and the performance characteristics of the improved analysis method are identified. Clinical samples are detected by both FAAS and inductively coupled plasma-optical emission spectroscopy (ICP-OES) for methodology evaluation. Results reveal that the proposed FAAS with multi-element HCLs could determine six essential minerals and trace elements within 15 min. This method provides a linear analytical range of 0.01-10 mg L(-1). For Ca, Cu, Fe, Mg, Mn, and Zn, the limits of determination are 1.5, 3, 1.8, 2.2, 2.1, and 1.3 microg L(-1), respectively. The mean relative standard deviations (RSDs) of intra- and interassays are lower than 7%. Excellent operational characteristics of rapidity, simplicity, and economy make the proposed method a promising one for the quantification of trace elements in human milk in clinics of underdeveloped areas.

  3. Simultaneous observation of free and defect-bound excitons in CH3NH3PbI3 using four-wave mixing spectroscopy

    NASA Astrophysics Data System (ADS)

    March, Samuel A.; Clegg, Charlotte; Riley, Drew B.; Webber, Daniel; Hill, Ian G.; Hall, Kimberley C.

    2016-12-01

    Solar cells incorporating organic-inorganic perovskite, which may be fabricated using low-cost solution-based processing, have witnessed a dramatic rise in efficiencies yet their fundamental photophysical properties are not well understood. The exciton binding energy, central to the charge collection process, has been the subject of considerable controversy due to subtleties in extracting it from conventional linear spectroscopy techniques due to strong broadening tied to disorder. Here we report the simultaneous observation of free and defect-bound excitons in CH3NH3PbI3 films using four-wave mixing (FWM) spectroscopy. Due to the high sensitivity of FWM to excitons, tied to their longer coherence decay times than unbound electron- hole pairs, we show that the exciton resonance energies can be directly observed from the nonlinear optical spectra. Our results indicate low-temperature binding energies of 13 meV (29 meV) for the free (defect-bound) exciton, with the 16 meV localization energy for excitons attributed to binding to point defects. Our findings shed light on the wide range of binding energies (2–55 meV) reported in recent years.

  4. Electrochemical lithiation/delithiation of SnP₂O₇ observed by in situ XRD and ex situ⁷Li/³¹P NMR, and ¹¹⁹Sn Mössbauer spectroscopy.

    PubMed

    Bezza, Ilham; Kaus, Maximilian; Riekehr, Lars; Pfaffmann, Lukas; Doyle, Stephen; Indris, Sylvio; Ehrenberg, Helmut; Solhy, Abderrahim; Saadoune, Ismael

    2016-04-21

    SnP2O7 was prepared by a sol-gel route. The structural changes of tin pyrophosphate during the electrochemical lithiation were followed by using in situ XRD measurements that reveal the existence of a crystalline phase at the beginning of the discharge process. Nevertheless, it becomes amorphous after the full discharge as a result of a conversion reaction leading to the formation of LixSny alloys. The electrochemical tests show a high capacity with high retention upon cycling. To better understand the reaction mechanism of SnP2O7 with Li, several techniques were applied, such as ex situ(119)Sn Mössbauer and ex situ(7)Li and (31)P NMR spectroscopies with which we can follow the changes in the local environment of each element during cycling.

  5. Second-derivative synchronous fluorescence spectroscopy for the simultaneous determination of cinnarizine and nicergoline in pharmaceutical preparations.

    PubMed

    Walash, Mohamed I; Belal, Fathalla; El-Enany, Nahed; Abdelal, Amina

    2008-01-01

    A rapid, simple, and highly sensitive second-derivative synchronous fluorometric method has been developed for the simultaneous analysis of binary mixtures of cinnarizine (CN) and nicergoline (NIC). The method is based upon measurement of the native fluorescence of these drugs at constant wavelength difference (Deltalambda) = 80 nm in aqueous methanol (50%, v/v). The different experimental parameters affecting the native fluorescence of the studied drugs were carefully studied and optimized. The fluorescence-concentration plots were rectilinear over the range of 0.025-1.5 and 0.25-5.5 microg/mL for CN and NIC, respectively, with lower detection limits of 0.58 and 0.82 ng/mL and quantitation limits of 1.93 and 2.73 ng/mL for CN and NIC, respectively. The proposed method was successfully applied for the determination of the studied compounds in synthetic mixtures and in commercial tablets. The results obtained were in good agreement with those obtained with reference methods. The high sensitivity attained by the proposed method allowed the determination of CN in real and spiked human plasma. The mean recovery in the case of spiked human plasma [number of trials (n) = 3] was 102.82 +/- 2.17%, while that in real human plasma (n = 3) was 105.25 +/- 2.05.

  6. Second-derivative synchronous fluorescence spectroscopy for the simultaneous determination of fluphenazine hydrochloride and nortriptyline hydrochloride in pharmaceutical preparations.

    PubMed

    Walash, M I; El-Brashy, A; El-Enany, N; Kamel, M E

    2009-09-01

    A rapid, simple, and highly sensitive second-derivative synchronous fluorimetric (SDSF) method has been developed for the simultaneous analysis of binary mixtures of fluphenazine hydrochloride (FLZ) and nortriptyline hydrochloride (NTP) in their co-formulated tablets. The method is based upon measurement of the native fluorescence of these drugs at constant wavelength difference (Deltalambda) = 120 nm in acetic acid. The different experimental parameters affecting the fluorescence intensity of the studied drugs were carefully studied and optimized. The fluorescence-concentration plots were rectilinear over the range of 0.25-3.0 and 1-10 microg/ml for FLZ and NTP respectively, with lower detection limits (LOD) of 0.05 and 0.18 microg/ml and quantitation limits of 0.15 and 0.53 microg/ml for FLZ and NTP respectively. The proposed method was successfully applied for the determination of the studied compounds in their synthetic mixtures and in commercial co-formulated tablets. The results obtained were in good agreement with those obtained by the reference methods.

  7. Simultaneous detection of molecular oxygen and water vapor in the tissue optical window using tunable diode laser spectroscopy.

    PubMed

    Persson, Linda; Lewander, Märta; Andersson, Mats; Svanberg, Katarina; Svanberg, Sune

    2008-04-20

    We report on a dual-diode laser spectroscopic system for simultaneous detection of two gases. The technique is demonstrated by performing gas measurements on absorbing samples such as an air distance, and on absorbing and scattering porous samples such as human tissue. In the latter it is possible to derive the concentration of one gas by normalizing to a second gas of known concentration. This is possible if the scattering and absorption of the bulk material is equal or similar for the two wavelengths used, resulting in a common effective pathlength. Two pigtailed diode lasers are operated in a wavelength modulation scheme to detect molecular oxygen ~760 nm and water vapor ~935 nm within the tissue optical window (600 nm to 1.3 mum). Different modulation frequencies are used to distinguish between the two wavelengths. No crosstalk can be observed between the gas contents measured in the two gas channels. The system is made compact by using a computer board and performing software-based lock-in detection. The noise floor obtained corresponds to an absorption fraction of approximately 6x10(-5) for both oxygen and water vapor, yielding a minimum detection limit of ~2 mm for both gases in ambient air. The power of the technique is illustrated by the preliminary results of a clinical trial, nonintrusively investigating gas in human sinuses.

  8. Simultaneous soft and hard X-ray spectroscopy of AM Herculis with EXOSAT: Discovery of photospheric absorption features

    NASA Technical Reports Server (NTRS)

    Paerels, Frits; Heise, John; Teeseling, Andre Van

    1994-01-01

    We present 0.1-10 keV spectroscopic observations of AM Herculis obtained with the Transmission Grating Spectrometers and Medium Energy experiments on EXOSAT, taken when the object was in its 'reversed X-ray mode.' The observation covers over six binary orbits without interruption, enabling us to analyze the phase and intensity dependence of both the hard and the soft spectrum simultaneously. We resolve the optically thick soft X-ray spectrum, and find definite evidence for time- and phase-dependent photospheric absorption structure arising in the white dwarf atmosphere. We present a simple empirical analysis of the combined soft and hard X-ray spectra, to examine whether the effect of a better determination of the column density of neutral absorbing material, afforded by our data, would solve the problem of the large relative soft X-ray overluminosity previously observed in AM Her. We find that a single absorbing column fits the entire spectrum, and that the column densities implied are indeed substantially lower than previously estimated. However, during half the binary orbit we still determine a strong lower limit to the soft-to-hard luminosity ratio of L(sub soft)/L(sub hard) is greater than or approximately equal to 10, in conflict with the simple radiative shock models for the accretion region. We argue that this indicates the need to reexamine the luminosity problem using explicit models for the emission spectrum based on a full solution of the atmospheric radiative transfer problem.

  9. HPLC and chemometrics-assisted UV-spectroscopy methods for the simultaneous determination of ambroxol and doxycycline in capsule

    NASA Astrophysics Data System (ADS)

    Hadad, Ghada M.; El-Gindy, Alaa; Mahmoud, Waleed M. M.

    2008-08-01

    High-performance liquid chromatography (HPLC) and multivariate spectrophotometric methods are described for the simultaneous determination of ambroxol hydrochloride (AM) and doxycycline (DX) in combined pharmaceutical capsules. The chromatographic separation was achieved on reversed-phase C 18 analytical column with a mobile phase consisting of a mixture of 20 mM potassium dihydrogen phosphate, pH 6-acetonitrile in ratio of (1:1, v/v) and UV detection at 245 nm. Also, the resolution has been accomplished by using numerical spectrophotometric methods as classical least squares (CLS), principal component regression (PCR) and partial least squares (PLS-1) applied to the UV spectra of the mixture and graphical spectrophotometric method as first derivative of the ratio spectra ( 1DD) method. Analytical figures of merit (FOM), such as sensitivity, selectivity, analytical sensitivity, limit of quantitation and limit of detection were determined for CLS, PLS-1 and PCR methods. The proposed methods were validated and successfully applied for the analysis of pharmaceutical formulation and laboratory-prepared mixtures containing the two component combination.

  10. Simultaneous intensive photometry and high resolution spectroscopy of δ Scuti stars. II. X Caeli: a star with unusual spectral features.

    NASA Astrophysics Data System (ADS)

    Mantegazza, L.; Poretti, E.

    1996-08-01

    Simultaneous photometric B, V (14 consecutive nights; 100 hours of observations) and high resolution spectroscopic observations (4 consecutive nights; 27 hours) were performed on the δ Scuti star X Caeli at La Silla Observatory in 1992. The photometric data allow the detection of 14 pulsation terms, some of which coincide in frequency with the second harmonics or the non-linear coupling terms of the lower frequency components. Possible excitation by resonance is suggested. The comparison with our previous observations of 1989 shows that while the amplitude of the strongest term (ν=7.39c/d) is very stable, a few other terms have changed their amplitudes. From the study of line profiles and their variations we derive vsin i=70km/s, 65deg<=i<=90deg, and that the dominant photometric term is a prograde mode with m=-1 and l=1 or 2. The other terms are probably non radial p modes with l=2+/-1. There is no evidence of the presence of high-degree sectorial modes with l=|m|. The stellar spectral lines have a narrow absorption core which could be due to the presence of a circumstellar shell.

  11. Simultaneous determination of hydrocarbon renewable diesel, biodiesel and petroleum diesel contents in diesel fuel blends using near infrared (NIR) spectroscopy and chemometrics.

    PubMed

    Alves, Julio Cesar Laurentino; Poppi, Ronei Jesus

    2013-11-07

    Highly polluting fuels based on non-renewable resources such as fossil fuels need to be replaced with potentially less polluting renewable fuels derived from vegetable or animal biomass, these so-called biofuels, are a reality nowadays and many countries have started the challenge of increasing the use of different types of biofuels, such as ethanol and biodiesel (fatty acid alkyl esters), often mixed with petroleum derivatives, such as gasoline and diesel, respectively. The quantitative determination of these fuel blends using simple, fast and low cost methods based on near infrared (NIR) spectroscopy combined with chemometric methods has been reported. However, advanced biofuels based on a mixture of hydrocarbons or a single hydrocarbon molecule, such as farnesane (2,6,10-trimethyldodecane), a hydrocarbon renewable diesel, can also be used in mixtures with biodiesel and petroleum diesel fuel and the use of NIR spectroscopy for the quantitative determination of a ternary fuel blend of these two hydrocarbon-based fuels and biodiesel can be a useful tool for quality control. This work presents a development of an analytical method for the quantitative determination of hydrocarbon renewable diesel (farnesane), biodiesel and petroleum diesel fuel blends using NIR spectroscopy combined with chemometric methods, such as partial least squares (PLS) and support vector machines (SVM). This development leads to a more accurate, simpler, faster and cheaper method when compared to the standard reference method ASTM D6866 and with the main advantage of providing the individual quantification of two different biofuels in a mixture with petroleum diesel fuel. Using the developed PLS model the three fuel blend components were determined simultaneously with values of root mean square error of prediction (RMSEP) of 0.25%, 0.19% and 0.38% for hydrocarbon renewable diesel, biodiesel and petroleum diesel, respectively, the values obtained were in agreement with those suggested by

  12. Functional Near Infrared Spectroscopy of the Sensory and Motor Brain Regions with Simultaneous Kinematic and EMG Monitoring During Motor Tasks

    PubMed Central

    Sukal-Moulton, Theresa; de Campos, Ana Carolina; Stanley, Christopher J.; Damiano, Diane L.

    2014-01-01

    There are several advantages that functional near-infrared spectroscopy (fNIRS) presents in the study of the neural control of human movement. It is relatively flexible with respect to participant positioning and allows for some head movements during tasks. Additionally, it is inexpensive, light weight, and portable, with very few contraindications to its use. This presents a unique opportunity to study functional brain activity during motor tasks in individuals who are typically developing, as well as those with movement disorders, such as cerebral palsy. An additional consideration when studying movement disorders, however, is the quality of actual movements performed and the potential for additional, unintended movements. Therefore, concurrent monitoring of both blood flow changes in the brain and actual movements of the body during testing is required for appropriate interpretation of fNIRS results. Here, we show a protocol for the combination of fNIRS with muscle and kinematic monitoring during motor tasks. We explore gait, a unilateral multi-joint movement (cycling), and two unilateral single-joint movements (isolated ankle dorsiflexion, and isolated hand squeezing). The techniques presented can be useful in studying both typical and atypical motor control, and can be modified to investigate a broad range of tasks and scientific questions. PMID:25548919

  13. Rapid and simultaneous determination of lycopene and beta-carotene contents in tomato juice by infrared spectroscopy.

    PubMed

    De Nardo, Thais; Shiroma-Kian, Cecilia; Halim, Yuwana; Francis, David; Rodriguez-Saona, Luis E

    2009-02-25

    The rapid quantification of lycopene and beta-carotene in tomato juices by attenuated total reflectance (ATR) infrared spectroscopy combined with multivariate analysis was evaluated. Two sample preparation methods were compared: a direct measurement of the tomato paste and an extraction method using hexane to isolate carotenoids. HPLC was used as the reference method. Cross-validated (leave-one-out) partial least-squares regression (PLSR) was used to create calibration models to predict these phytonutrient concentrations in blind test samples. The infrared spectra showed unique marker bands at 957 and 968 cm(-1) for lycopene and beta-carotene, respectively. Multivariate analysis of the infrared spectral data gave correlation coefficients (r values) of >0.9 between the ATR-IR predicted and HPLC reference values, and standard errors of cross-validation (SECV) of 0.5 and 0.04 mg/100 g of juice for lycopene and beta-carotene, respectively. ATR-IR could provide the tomato industry with a simple, rapid, and high-throughput technique for the determination of tomato quality.

  14. Simultaneous K- and L-band Spectroscopy of Be Stars: Circumstellar Envelope Properties from Hydrogen Emission Lines

    NASA Astrophysics Data System (ADS)

    Granada, A.; Arias, M. L.; Cidale, L. S.

    2010-05-01

    We present medium-resolution K- and L-band spectra of a sample of eight Be stars, obtained with Gemini/NIRI. The IR K and L bands contain many lines of different hydrogen series that are used as a diagnosis to the physical conditions in the circumstellar environments. We make an analysis on the optical depths of the line-forming regions based on the intensity ratios of Pfγ and Brα lines, the behavior of Humphreys' series, and the fluxes of Brα and Brγ lines. All our targets show spectroscopic and photometric long-term variability; thus, time-resolved K- and L-band spectroscopy is an ideal tool for studying the structure and evolution of the innermost regions of the envelope and to test models on the disk-forming mechanism. We note that the instrumental configuration used allowed us to obtain good quality IR observations and to take profit of Gemini band 3 observing time (allocation time for ranked programs in which the observing conditions are relaxed). Based on observations obtained at the Gemini Observatory, which is operated by the Association of Universities for Research in Astronomy, Inc., under a cooperative agreement with the NSF on behalf of the Gemini partnership: the National Science Foundation (USA), the Science and Technology Facilities Council (UK), the National Research Council (Canada), CONICYT (Chile), the Australian Research Council (Australia), Ministério da Ciência e Tecnologia (Brazil), and Ministerio de Ciencia, Tecnología e Innovación Productiva (Argentina).

  15. Studying cerebral hemodynamics and metabolism using simultaneous near-infrared spectroscopy and transcranial Doppler ultrasound: a hyperventilation and caffeine study

    PubMed Central

    Yang, Runze; Brugniaux, Julien; Dhaliwal, Harinder; Beaudin, Andrew E; Eliasziw, Misha; Poulin, Marc J; Dunn, Jeff F

    2015-01-01

    Caffeine is one of the most widely consumed psycho-stimulants in the world, yet little is known about its effects on brain oxygenation and metabolism. Using a double-blind, placebo-controlled, randomized cross-over study design, we combined transcranial Doppler ultrasound (TCD) and near-infrared spectroscopy (NIRS) to study caffeine's effect on middle cerebral artery peak blood flow velocity (Vp), brain tissue oxygenation (StO2), total hemoglobin (tHb), and cerebral oxygen metabolism (CMRO2) in five subjects. Hyperventilation-induced hypocapnia served as a control to verify the sensitivity of our measurements. During hypocapnia (∼16 mmHg below resting values), Vp decreased by 40.0 ± 2.4% (95% CI, P < 0.001), while StO2 and tHb decreased by 2.9 ± 0.3% and 2.6 ± 0.4%, respectively (P = 0.003 and P = 0.002, respectively). CMRO2, calculated using the Fick equation, was reduced by 29.3 ± 9% compared to the isocapnic-euoxia baseline (P < 0.001). In the pharmacological experiments, there was a significant decrease in Vp, StO2, and tHb after ingestion of 200 mg of caffeine compared with placebo. There was no significant difference in CMRO2 between caffeine and placebo. Both showed a CMRO2 decline compared to baseline showing the importance of a placebo control. In conclusion, this study showed that profound hypocapnia impairs cerebral oxidative metabolism. We provide new insight into the effects of caffeine on cerebral hemodynamics. Moreover, this study showed that multimodal NIRS/TCD is an excellent tool for studying brain hemodynamic responses to pharmacological interventions and physiological challenges. PMID:25907789

  16. Simultaneous Determination of Acetaminophen and Synthetic Color(s) by Derivative Spectroscopy in Syrup Formulations and Validation by HPLC: Exposure Risk of Colors to Children.

    PubMed

    Rastogi, Shanya Das; Dixit, Sumita; Tripathi, Anurag; Das, Mukul

    2015-06-01

    Color additives are used in pediatric syrup formulations as an excipient; though not pre-requisite, but pediatric syrup formulations are normally colored. An attempt has been made to measure simultaneously the single drug, acetaminophen (AT), along with the colors, carmoisine (CA), erythrosine (ET), and sunset yellow FCF (SSY) added in it by three derivative spectroscopy methods namely, 1st order, ratio, and differential derivative methods. Moreover, evaluation has been made for the exposure assessment of the colors added as excipient because some colors have been reported to cause allergic reactions and hypersensitivity in children. The present methods provide simple, accurate, and reproducible quantitative determination of the drug, AT, along with the color in synthetic mixtures and commercial drug formulations without any interference. The limit of detection varied from 0.0001-0.31 μg/ml while limit of quantification ranged from 0.002-1.04 μg/ml in all the three methods. The calibration curve of all the three derivative methods exhibited good linear relationship with excellent regression coefficients (0.9986-1.000). Both intra-day and inter-day precisions showed %RSD value less than 2% while the percentage recovery was found between 96.8-103.8%. The sensitivity of the proposed methods is almost comparable to HPLC and thus, can be used for determination of drug AT, and color simultaneously in pharmaceutical formulation on routine basis. The present methods also showed that colors like SSY and ET are saturating more than 50% of acceptable daily intake (ADI) value which is alarming and needs to be considered for modification by regulatory authorities to safeguard the health of children.

  17. Qualitative and simultaneous quantitative analysis of cimetidine polymorphs by ultraviolet-visible and shortwave near-infrared diffuse reflectance spectroscopy and multivariate calibration models.

    PubMed

    Feng, Yuyan; Li, Xiangling; Xu, Kailin; Zou, Huayu; Li, Hui; Liang, Bing

    2015-02-01

    The object of the present study was to investigate the feasibility of applying ultraviolet-visible and shortwave near-infrared diffuse reflectance spectroscopy (UV-vis-SWNIR DRS) coupled with chemometrics in qualitative and simultaneous quantitative analysis of drug polymorphs, using cimetidine as a model drug. Three polymorphic forms (A, B and D) and a mixed crystal (M1) of cimetidine, obtained by preparation under different crystallization conditions, were characterized by microscopy, X-ray powder diffraction (XRPD) and infrared spectroscopy (IR). The discriminant models of four forms (A, B, D and M1) were established by discriminant partial least squares (PLS-DA) using different pretreated spectra. The R and RMSEP of samples in the prediction set by discriminant model with original spectra were 0.9959 and 0.1004. Among the quantitative models of binary mixtures (A and D) established by partial least squares (PLS) and least squares-support vector machine (LS-SVM) with different pretreated spectra, the LS-SVM models based on original and MSC spectra had better prediction effect with a R of 1.0000 and a RMSEP of 0.0134 for form A, and a R of 1.0000 and a RMSEP of 0.0024 for form D. For ternary mixtures, the established PLS quantitative models based on normalized spectra had relatively better prediction effect for forms A, B and D with R of 0.9901, 0.9820 and 0.9794 and RMSEP of 0.0471, 0.0529 and 0.0594, respectively. This research indicated that UV-vis-SWNIR DRS can be used as a simple, rapid, nondestructive qualitative and quantitative method for the analysis of drug polymorphs.

  18. Hemodynamic and electrophysiological signals of conflict processing in the Chinese-character Stroop task: a simultaneous near-infrared spectroscopy and event-related potential study

    NASA Astrophysics Data System (ADS)

    Zhai, Jiahuan; Li, Ting; Zhang, Zhongxing; Gong, Hui

    2009-09-01

    A dual-modality method combining continuous-wave near-infrared spectroscopy (NIRS) and event-related potentials (ERPs) was developed for the Chinese-character color-word Stroop task, which included congruent, incongruent, and neutral stimuli. Sixteen native Chinese speakers participated in this study. Hemodynamic and electrophysiological signals in the prefrontal cortex (PFC) were monitored simultaneously by NIRS and ERP. The hemodynamic signals were represented by relative changes in oxy-, deoxy-, and total hemoglobin concentration, whereas the electrophysiological signals were characterized by the parameters P450, N500, and P600. Both types of signals measured at four regions of the PFC were analyzed and compared spatially and temporally among the three different stimuli. We found that P600 signals correlated significantly with the hemodynamic parameters, suggesting that the PFC executes conflict-solving function. Additionally, we observed that the change in deoxy-Hb concentration showed higher sensitivity in response to the Stroop task than other hemodynamic signals. Correlation between NIRS and ERP signals revealed that the vascular response reflects the cumulative effect of neural activities. Taken together, our findings demonstrate that this new dual-modality method is a useful approach to obtaining more information during cognitive and physiological studies.

  19. Simultaneous determination of penicillin G salts by infrared spectroscopy: Evaluation of combining orthogonal signal correction with radial basis function-partial least squares regression

    NASA Astrophysics Data System (ADS)

    Talebpour, Zahra; Tavallaie, Roya; Ahmadi, Seyyed Hamid; Abdollahpour, Assem

    2010-09-01

    In this study, a new method for the simultaneous determination of penicillin G salts in pharmaceutical mixture via FT-IR spectroscopy combined with chemometrics was investigated. The mixture of penicillin G salts is a complex system due to similar analytical characteristics of components. Partial least squares (PLS) and radial basis function-partial least squares (RBF-PLS) were used to develop the linear and nonlinear relation between spectra and components, respectively. The orthogonal signal correction (OSC) preprocessing method was used to correct unexpected information, such as spectral overlapping and scattering effects. In order to compare the influence of OSC on PLS and RBF-PLS models, the optimal linear (PLS) and nonlinear (RBF-PLS) models based on conventional and OSC preprocessed spectra were established and compared. The obtained results demonstrated that OSC clearly enhanced the performance of both RBF-PLS and PLS calibration models. Also in the case of some nonlinear relation between spectra and component, OSC-RBF-PLS gave satisfactory results than OSC-PLS model which indicated that the OSC was helpful to remove extrinsic deviations from linearity without elimination of nonlinear information related to component. The chemometric models were tested on an external dataset and finally applied to the analysis commercialized injection product of penicillin G salts.

  20. Direct and simultaneous quantification of tannin mean degree of polymerization and percentage of galloylation in grape seeds using diffuse reflectance fourier transform-infrared spectroscopy.

    PubMed

    Pappas, Christos; Kyraleou, Maria; Voskidi, Eleni; Kotseridis, Yorgos; Taranilis, Petros A; Kallithraka, Stamatina

    2015-02-01

    The direct and simultaneous quantitative determination of the mean degree of polymerization (mDP) and the degree of galloylation (%G) in grape seeds were quantified using diffuse reflectance infrared Fourier transform spectroscopy and partial least squares (PLS). The results were compared with those obtained using the conventional analysis employing phloroglucinolysis as pretreatment followed by high performance liquid chromatography-UV and mass spectrometry detection. Infrared spectra were recorded in solid state samples after freeze drying. The 2nd derivative of the 1832 to 1416 and 918 to 739 cm(-1) spectral regions for the quantification of mDP, the 2nd derivative of the 1813 to 607 cm(-1) spectral region for the degree of %G determination and PLS regression were used. The determination coefficients (R(2) ) of mDP and %G were 0.99 and 0.98, respectively. The corresponding values of the root-mean-square error of calibration were found 0.506 and 0.692, the root-mean-square error of cross validation 0.811 and 0.921, and the root-mean-square error of prediction 0.612 and 0.801. The proposed method in comparison with the conventional method is simpler, less time consuming, more economical, and requires reduced quantities of chemical reagents and fewer sample pretreatment steps. It could be a starting point for the design of more specific models according to the requirements of the wineries.

  1. Simultaneous speciation and preconcentration of ultra traces of inorganic tellurium and selenium in environmental samples by hollow fiber liquid phase microextraction prior to electrothermal atomic absorption spectroscopy determination.

    PubMed

    Ghasemi, Ensieh; Najafi, Nahid Mashkouri; Raofie, Farhad; Ghassempour, Alireza

    2010-09-15

    A simple and effective speciation and preconcentration method based on hollow fiber liquid phase microextraction (HF-LPME) was developed for simultaneous separation of trace inorganic tellurium and selenium in environmental samples prior to electrothermal atomic absorption spectroscopy (ETAAS) determination. The method involves the selective extraction of the Te (IV) and Se (IV) species by HF-LPME with the use of ammonium pyrrolidinecarbodithioate (APDC) as the chelating agent. The complex compounds were extracted into 10 microL of toluene and the solutions were injected into a graphite furnace for the determination of Te (IV) and Se (IV). To determine the total tellurium and selenium in the samples, first Te (VI) and Se (VI) were reduced to Te (IV) and Se (IV), and then the microextraction method was performed. The experimental parameters of HF-LPME were optimized using a central composite design after a 2(n-1) fractional factorial experimental design. Under optimum conditions, enrichment factors of up to 520 and 480 were achieved for Te (IV) and Se (IV), respectively. The detection limits were 4 ng L(-1) with 3.5% RSD (n=5, c=2.0 microg L(-1)) for Te (IV) and 5 ng L(-1) with 3.1% RSD for Se (IV). The applicability of the developed technique was evaluated by application to spiked, environmental water and soil samples.

  2. Mapping Cortical Responses to Somatosensory Stimuli in Human Infants with Simultaneous Near-Infrared Spectroscopy and Event-Related Potential Recording123

    PubMed Central

    Fabrizi, Lorenzo; Lee, Amy; Cooper, Robert J.; Fitzgerald, Maria; Meek, Judith

    2016-01-01

    Abstract Near-infrared spectroscopy (NIRS) and electroencephalography (EEG) have recently provided fundamental new information about how the newborn brain processes innocuous and noxious somatosensory information. However, results derived independently from these two techniques are not entirely consistent, raising questions about the relationship between hemodynamic and electrophysiological responses in the study of touch and pain processing in the newborn. To address this, we have recorded NIRS and EEG responses simultaneously for the first time in the human infant following noxious (time-locked clinically required heel lances) and innocuous tactile cutaneous stimulation in 30 newborn infants. The results show that both techniques can be used to record quantifiable and distinct innocuous and noxious evoked activity at a group level in the newborn cortex. Noxious stimulation elicits a peak hemodynamic response that is 10-fold larger than that elicited by an innocuous stimulus (HbO2: 2.0 vs 0.3 µm) and a distinct nociceptive-specific N3P3 waveform in electrophysiological recordings. However, a novel single-trial analysis revealed that hemodynamic and electrophysiological responses do not always co-occur at an individual level, although when they do (64% of noxious test occasions), they are significantly correlated in magnitude. These data show that, while hemodynamic and electrophysiological touch and pain brain activity in newborn infants are comparable in group analyses, important individual differences remain. These data indicate that integrated and multimodal brain monitoring is required to understand central touch and pain processing in the newborn. PMID:27200413

  3. Using UV-Vis spectroscopy for simultaneous geographical and varietal classification of tea infusions simulating a home-made tea cup.

    PubMed

    Diniz, Paulo Henrique Gonçalves Dias; Barbosa, Mayara Ferreira; de Melo Milanez, Karla Danielle Tavares; Pistonesi, Marcelo Fabián; de Araújo, Mário César Ugulino

    2016-02-01

    In this work we proposed a method to verify the differentiating characteristics of simple tea infusions prepared in boiling water alone (simulating a home-made tea cup), which represents the final product as ingested by the consumers. For this purpose we used UV-Vis spectroscopy and variable selection through the Successive Projections Algorithm associated with Linear Discriminant Analysis (SPA-LDA) for simultaneous classification of the teas according to their variety and geographic origin. For comparison, KNN, CART, SIMCA, PLS-DA and PCA-LDA were also used. SPA-LDA and PCA-LDA provided significantly better results for tea classification of the five studied classes (Argentinean green tea; Brazilian green tea; Argentinean black tea; Brazilian black tea; and Sri Lankan black tea). The proposed methodology provides a simpler, faster and more affordable classification of simple tea infusions, and can be used as an alternative approach to traditional tea quality evaluation as made by skilful tasters, which is evidently partial and cannot assess geographic origins.

  4. CW EC-QCL-based sensor for simultaneous detection of H2O, HDO, N2O and CH4 using multi-pass absorption spectroscopy

    DOE PAGES

    Yu, Yajun; Sanchez, Nancy P.; Griffin, Robert J.; ...

    2016-05-03

    A sensor system based on a continuous wave, external-cavity quantum-cascade laser (CW EC-QCL) was demonstrated for simultaneous detection of atmospheric H2O, HDO, N2O and CH4 using a compact, dense pattern multi-pass gas cell with an effective path-length of 57.6 m. The EC-QCL with a mode-hop-free spectral range of 1225-1285 cm-1 operating at similar to 7.8 mu m was scanned covering four neighboring absorption lines, for H2O at 1281.161 cm-1, HDO at 1281.455 cm-1, N2O at 1281.53 cm-1 and CH4 at 1281.61 cm-1. A first-harmonic-normalized wavelength modulation spectroscopy with second-harmonic detection (WMS-2f/1f) strategy was employed for data processing. An Allan-Werle deviationmore » analysis indicated that minimum detection limits of 1.77 ppmv for H2O, 3.92 ppbv for HDO, 1.43 ppbv for N2O, and 2.2 ppbv for CH4 were achieved with integration times of 50-s, 50-s, 100-s and 129-s, respectively. In conclusion, experimental measurements of ambient air are also reported.« less

  5. Simultaneous Enrichment and On-line Detection of Low-Concentration Copper, Cobalt, and Nickel Ions in Water by Near-Infrared Diffuse Reflectance Spectroscopy Combined with Chemometrics.

    PubMed

    Iqbal, Jibran; Du, Yiping; Howari, Fares; Bataineh, Mahmoud; Muhammad, Nawshad; Rahim, Abdur

    2017-03-01

    Sensitive detection of heavy metal ions in water is of great importance considering the effects that heavy metals have on public health. A developed fluidized bed enrichment technique was used to concentrate and detect low concentrations of Cu2+, Co2+, and Ni2+ in water samples by near-IR diffuse reflectance (NIDR) spectroscopy (NIDRS) directly without using any chemicals or reagents. The NIDR spectra of adsorbent were measured on-line, and quantitative detection was achieved by applying a built partial least-squares chemometric model. Sensitivity and accuracy was improved significantly because large-volume mixture solutions were used in the enrichment process. Root mean square error of cross-validation values for Cu2+, Co2+, and Ni2+ were 0.29, 0.41, and 0.35 μg/mL, respectively, with mean relative error values in the acceptable range of 6.56-10.27%. This study confirms the potential application of fluidized bed enrichment combined with NIDRS and chemometrics for the simultaneous detection of trace heavy metal ions in water, with low relative error.

  6. Multivariate classification of edible salts: Simultaneous Laser-Induced Breakdown Spectroscopy and Laser-Ablation Inductively Coupled Plasma Mass Spectrometry Analysis

    NASA Astrophysics Data System (ADS)

    Lee, Yonghoon; Nam, Sang-Ho; Ham, Kyung-Sik; Gonzalez, Jhanis; Oropeza, Dayana; Quarles, Derrick; Yoo, Jonghyun; Russo, Richard E.

    2016-04-01

    Laser-Induced Breakdown Spectroscopy (LIBS) and Laser-Ablation Inductively Coupled Plasma Mass Spectrometry (LA-ICP-MS), both based on laser ablation sampling, can be employed simultaneously to obtain different chemical fingerprints from a sample. We demonstrated that this analysis approach can provide complementary information for improved classification of edible salts. LIBS could detect several of the minor metallic elements along with Na and Cl, while LA-ICP-MS spectra were used to measure non-metallic and trace heavy metal elements. Principal component analysis using LIBS and LA-ICP-MS spectra showed that their major spectral variations classified the sample salts in different ways. Three classification models were developed by using partial least squares-discriminant analysis based on the LIBS, LA-ICP-MS, and their fused data. From the cross-validation performances and confusion matrices of these models, the minor metallic elements (Mg, Ca, and K) detected by LIBS and the non-metallic (I) and trace heavy metal (Ba, W, and Pb) elements detected by LA-ICP-MS provided complementary chemical information to distinguish particular salt samples.

  7. Simultaneous analysis of 17O/16O, 18O/16O and 2H/1H of gypsum hydration water by cavity ring‐down laser spectroscopy

    PubMed Central

    Mather, Ian; Rolfe, James; Evans, Nicholas P.; Herwartz, Daniel; Staubwasser, Michael; Hodell, David A.

    2015-01-01

    Rationale The recent development of cavity ring‐down laser spectroscopy (CRDS) instruments capable of measuring 17O‐excess in water has created new opportunities for studying the hydrologic cycle. Here we apply this new method to studying the triple oxygen (17O/16O, 18O/16O) and hydrogen (2H/1H) isotope ratios of gypsum hydration water (GHW), which can provide information about the conditions under which the mineral formed and subsequent post‐depositional interaction with other fluids. Methods We developed a semi‐automated procedure for extracting GHW by slowly heating the sample to 400°C in vacuo and cryogenically trapping the evolved water. The isotopic composition (δ17O, δ18O and δ2H values) of the GHW is subsequently measured by CRDS. The extraction apparatus allows the dehydration of five samples and one standard simultaneously, thereby increasing the long‐term precision and sample throughput compared with previous methods. The apparatus is also useful for distilling brines prior to isotopic analysis. A direct comparison is made between results of 17O‐excess in GHW obtained by CRDS and fluorination followed by isotope ratio mass spectrometry (IRMS) of O2. Results The long‐term analytical precision of our method of extraction and isotopic analysis of GHW by CRDS is ±0.07‰ for δ17O values, ±0.13‰ for δ18O values and ±0.49‰ for δ2H values (all ±1SD), and ±1.1‰ and ±8 per meg for the deuterium‐excess and 17O‐excess, respectively. Accurate measurement of the 17O‐excess values of GHW, of both synthetic and natural samples, requires the use of a micro‐combustion module (MCM). This accessory removes contaminants (VOCs, H2S, etc.) from the water vapour stream that interfere with the wavelengths used for spectroscopic measurement of water isotopologues. CRDS/MCM and IRMS methods yield similar isotopic results for the analysis of both synthetic and natural gypsum samples within analytical error of the two methods. Conclusions We

  8. Simultaneous detection of electronic structure changes from two elements of a bifunctional catalyst using wavelength-dispersive X-ray emission spectroscopy and in situ electrochemistry

    DOE PAGES

    Gul, Sheraz; Ng, Jia Wei Desmond; Alonso-Mori, Roberto; ...

    2015-02-25

    Multielectron catalytic reactions, such as water oxidation, nitrogen reduction, or hydrogen production in enzymes and inorganic catalysts often involve multimetallic clusters. In these systems, the reaction takes place between metals or metals and ligands to facilitate charge transfer, bond formation/breaking, substrate binding, and release of products. In this study, we present a method to detect X-ray emission signals from multiple elements simultaneously, which allows for the study of charge transfer and the sequential chemistry occurring between elements. Kβ X-ray emission spectroscopy (XES) probes charge and spin states of metals as well as their ligand environment. A wavelength-dispersive spectrometer based onmore » the von Hamos geometry was used to disperse Kβ signals of multiple elements onto a position detector, enabling an XES spectrum to be measured in a single-shot mode. This overcomes the scanning needs of the scanning spectrometers, providing data free from temporal and normalization errors and therefore ideal to follow sequential chemistry at multiple sites. We have applied this method to study MnOx-based bifunctional electrocatalysts for the oxygen evolution reaction (OER) and the oxygen reduction reaction (ORR). In particular, we investigated the effects of adding a secondary element, Ni, to form MnNiOx and its impact on the chemical states and catalytic activity, by tracking the redox characteristics of each element upon sweeping the electrode potential. In conclusion, the detection scheme we describe here is general and can be applied to time-resolved studies of materials consisting of multiple elements, to follow the dynamics of catalytic and electron transfer reactions.« less

  9. Simultaneous existence of defects and mesopores in nanosized ZSM-5 zeolite studied by positron annihilation and X-ray diffraction spectroscopies

    NASA Astrophysics Data System (ADS)

    Anh Tuyen, L.; Quang Hung, N.; Chi Cuong, L.; Duy Khiem, D.; Trong Phuc, P.; Ly Nguyen, L.; Ngoc Hue, N. T.; Thi Hue, P.; Van Phuc, D.

    2017-02-01

    Crystallization, formation, and accumulation of defects and mesopores in the ZSM-5 zeolite samples, which are synthesized from the gel composition of 1.2Na2O 0.1Al2O3 0.8 tetra-propylammonium hydroxide (TPAOH) 6SiO2 400H2O at a temperature of 140 degree Celsius (°C) in 10, 15, and 18 h, are studied by using the Positron annihilation lifetime (PALS) and X-ray diffraction (XRD) spectroscopies. The XRD is used for investigating the crystalline concentration and nano-crystal size of ZSM-5 during the crystallizing process, whereas the PALS is performed in order to determine the presence of templates, defects, and mesopores in the zeolite samples. The latter are calcined in air during 1, 2, and 3 h at a temperature of 600 °C before being measured. The results obtained indicate that there exist clusters of small crystals in the early crystalline stages of the samples. The size of these crystals increases with time and reaches approximately 100 nm after 18 h of reaction. In addition, the template (TPAOH) is found to exist not only in the channels inside the framework but also in the mesopores outside it. Finally, by analyzing the Positron lifetime spectra, we have found for the first time the simultaneous existence of defects and mesopores, which are formatted and accumulated during the crystallization of ZSM-5. Those important results contribute significantly to our understanding of the internal structure of the synthetic zeolite ZSM-5 as well as the synthetic processes for producing zeolites with special features.

  10. Ring-oven based preconcentration technique for microanalysis: simultaneous determination of Na, Fe, and Cu in fuel ethanol by laser induced breakdown spectroscopy.

    PubMed

    Cortez, Juliana; Pasquini, Celio

    2013-02-05

    The ring-oven technique, originally applied for classical qualitative analysis in the years 1950s to 1970s, is revisited to be used in a simple though highly efficient and green procedure for analyte preconcentration prior to its determination by the microanalytical techniques presently available. The proposed preconcentration technique is based on the dropwise delivery of a small volume of sample to a filter paper substrate, assisted by a flow-injection-like system. The filter paper is maintained in a small circular heated oven (the ring oven). Drops of the sample solution diffuse by capillarity from the center to a circular area of the paper substrate. After the total sample volume has been delivered, a ring with a sharp (c.a. 350 μm) circular contour, of about 2.0 cm diameter, is formed on the paper to contain most of the analytes originally present in the sample volume. Preconcentration coefficients of the analyte can reach 250-fold (on a m/m basis) for a sample volume as small as 600 μL. The proposed system and procedure have been evaluated to concentrate Na, Fe, and Cu in fuel ethanol, followed by simultaneous direct determination of these species in the ring contour, employing the microanalytical technique of laser induced breakdown spectroscopy (LIBS). Detection limits of 0.7, 0.4, and 0.3 μg mL(-1) and mean recoveries of (109 ± 13)%, (92 ± 18)%, and (98 ± 12)%, for Na, Fe, and Cu, respectively, were obtained in fuel ethanol. It is possible to anticipate the application of the technique, coupled to modern microanalytical and multianalyte techniques, to several analytical problems requiring analyte preconcentration and/or sample stabilization.

  11. Simultaneous acquisition of magnetic resonance spectroscopy (MRS) data and positron emission tomography (PET) images with a prototype MR-compatible, small animal PET imager

    NASA Astrophysics Data System (ADS)

    Raylman, Raymond R.; Majewski, Stan; Velan, S. Sendhil; Lemieux, Susan; Kross, Brian; Popov, Vladimir; Smith, Mark F.; Weisenberger, Andrew G.

    2007-06-01

    Multi-modality imaging (such as PET-CT) is rapidly becoming a valuable tool in the diagnosis of disease and in the development of new drugs. Functional images produced with PET, fused with anatomical images created by MRI, allow the correlation of form with function. Perhaps more exciting than the combination of anatomical MRI with PET, is the melding of PET with MR spectroscopy (MRS). Thus, two aspects of physiology could be combined in novel ways to produce new insights into the physiology of normal and pathological processes. Our team is developing a system to acquire MRI images and MRS spectra, and PET images contemporaneously. The prototype MR-compatible PET system consists of two opposed detector heads (appropriate in size for small animal imaging), operating in coincidence mode with an active field-of-view of ˜14 cm in diameter. Each detector consists of an array of LSO detector elements coupled through a 2-m long fiber optic light guide to a single position-sensitive photomultiplier tube. The use of light guides allows these magnetic field-sensitive elements of the PET imager to be positioned outside the strong magnetic field of our 3T MRI scanner. The PET scanner imager was integrated with a 12-cm diameter, 12-leg custom, birdcage coil. Simultaneous MRS spectra and PET images were successfully acquired from a multi-modality phantom consisting of a sphere filled with 17 brain relevant substances and a positron-emitting radionuclide. There were no significant changes in MRI or PET scanner performance when both were present in the MRI magnet bore. This successful initial test demonstrates the potential for using such a multi-modality to obtain complementary MRS and PET data.

  12. Simultaneous Detection of Electronic Structure Changes from Two Elements of a Bifunctional Catalyst Using Wavelength-Dispersive X-ray Emission Spectroscopy and in situ Electrochemistry

    PubMed Central

    Gul, Sheraz; Desmond Ng, Jia Wei; Alonso-Mori, Roberto; Kern, Jan; Sokaras, Dimosthenis; Anzenberg, Eitan; Lassalle-Kaiser, Benedikt; Gorlin, Yelena; Weng, Tsu-Chien; Zwart, Petrus H.; Zhang, Jin Z.; Bergmann, Uwe; Yachandra, Vittal K.; Jaramillo, Thomas F.; Yano, Junko

    2015-01-01

    Multielectron catalytic reactions, such as water oxidation, nitrogen reduction, or hydrogen production in enzymes and inorganic catalysts often involve multimetallic clusters. In these systems, the reaction takes place between metals or metals and ligands to facilitate charge transfer, bond formation/breaking, substrate binding, and release of products. In this study, we present a method to detect X-ray emission signals from multiple elements simultaneously, which allows for the study of charge transfer and the sequential chemistry occurring between elements. Kβ X-ray emission spectroscopy (XES) probes charge and spin states of metals as well as their ligand environment. A wavelength-dispersive spectrometer based on the von Hamos geometry was used to disperse Kβ signals of multiple elements onto a position detector, enabling an XES spectrum to be measured in a single-shot mode. This overcomes the scanning needs of the scanning spectrometers, providing data free from temporal and normalization errors and therefore ideal to follow sequential chemistry at multiple sites. We have applied this method to study MnOx-based bifunctional electrocatalysts for the oxygen evolution reaction (OER) and the oxygen reduction reaction (ORR). In particular, we investigated the effects of adding a secondary element, Ni, to form MnNiOx and its impact on the chemical states and catalytic activity, by tracking the redox characteristics of each element upon sweeping the electrode potential. The detection scheme we describe here is general and can be applied to time-resolved studies of materials consisting of multiple elements, to follow the dynamics of catalytic and electron transfer reactions. PMID:25747045

  13. Simultaneous detection of electronic structure changes from two elements of a bifunctional catalyst using wavelength-dispersive X-ray emission spectroscopy and in situ electrochemistry

    SciTech Connect

    Gul, Sheraz; Ng, Jia Wei Desmond; Alonso-Mori, Roberto; Kern, Jan; Sokaras, Dimosthenis; Anzenberg, Eitan; Lassalle-Kaiser, Benedikt; Gorlin, Yelena; Weng, Tsu-Chien; Zwart, Petrus H.; Zhang, Jin Z.; Bergmann, Uwe; Yachandra, Vittal K.; Jaramillo, Thomas F.; Yano, Junko

    2015-02-25

    Multielectron catalytic reactions, such as water oxidation, nitrogen reduction, or hydrogen production in enzymes and inorganic catalysts often involve multimetallic clusters. In these systems, the reaction takes place between metals or metals and ligands to facilitate charge transfer, bond formation/breaking, substrate binding, and release of products. In this study, we present a method to detect X-ray emission signals from multiple elements simultaneously, which allows for the study of charge transfer and the sequential chemistry occurring between elements. Kβ X-ray emission spectroscopy (XES) probes charge and spin states of metals as well as their ligand environment. A wavelength-dispersive spectrometer based on the von Hamos geometry was used to disperse Kβ signals of multiple elements onto a position detector, enabling an XES spectrum to be measured in a single-shot mode. This overcomes the scanning needs of the scanning spectrometers, providing data free from temporal and normalization errors and therefore ideal to follow sequential chemistry at multiple sites. We have applied this method to study MnOx-based bifunctional electrocatalysts for the oxygen evolution reaction (OER) and the oxygen reduction reaction (ORR). In particular, we investigated the effects of adding a secondary element, Ni, to form MnNiOx and its impact on the chemical states and catalytic activity, by tracking the redox characteristics of each element upon sweeping the electrode potential. In conclusion, the detection scheme we describe here is general and can be applied to time-resolved studies of materials consisting of multiple elements, to follow the dynamics of catalytic and electron transfer reactions.

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

    SciTech Connect

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

    2014-03-07

    Various {sup 2}H and {sup 31}P nuclear magnetic resonance (NMR) spectroscopy techniques are applied to probe the component dynamics of the binary glass former tripropyl phosphate (TPP)/polystyrene-d{sub 3} (PS) over the full concentration range. The results are quantitatively compared to those of a dielectric spectroscopy (DS) study on the same system previously published [R. Kahlau, D. Bock, B. Schmidtke, and E. A. Rössler, J. Chem. Phys. 140, 044509 (2014)]. While the PS dynamics does not significantly change in the mixtures compared to that of neat PS, two fractions of TPP molecules are identified, one joining the glass transition of PS in the mixture (α{sub 1}-process), the second reorienting isotropically (α{sub 2}-process) even in the rigid matrix of PS, although at low concentration resembling a secondary process regarding its manifestation in the DS spectra. Pronounced dynamical heterogeneities are found for the TPP α{sub 2}-process, showing up in extremely stretched, quasi-logarithmic stimulated echo decays. While the time window of NMR is insufficient for recording the full correlation functions, DS results, covering a larger dynamical range, provide a satisfactory interpolation of the NMR data. Two-dimensional {sup 31}P NMR spectra prove exchange within the broadly distributed α{sub 2}-process. As demonstrated by {sup 2}H NMR, the PS matrix reflects the faster α{sub 2}-process of TPP by performing a spatially highly hindered motion on the same timescale.

  15. Skeletal Muscle Quantitative Nuclear Magnetic Resonance Imaging and Spectroscopy as an Outcome Measure for Clinical Trials

    PubMed Central

    Carlier, Pierre G.; Marty, Benjamin; Scheidegger, Olivier; Loureiro de Sousa, Paulo; Baudin, Pierre-Yves; Snezhko, Eduard; Vlodavets, Dmitry

    2016-01-01

    Recent years have seen tremendous progress towards therapy of many previously incurable neuromuscular diseases. This new context has acted as a driving force for the development of novel non-invasive outcome measures. These can be organized in three main categories: functional tools, fluid biomarkers and imagery. In the latest category, nuclear magnetic resonance imaging (NMRI) offers a considerable range of possibilities for the characterization of skeletal muscle composition, function and metabolism. Nowadays, three NMR outcome measures are frequently integrated in clinical research protocols. They are: 1/ the muscle cross sectional area or volume, 2/ the percentage of intramuscular fat and 3/ the muscle water T2, which quantity muscle trophicity, chronic fatty degenerative changes and oedema (or more broadly, “disease activity”), respectively. A fourth biomarker, the contractile tissue volume is easily derived from the first two ones. The fat fraction maps most often acquired with Dixon sequences have proven their capability to detect small changes in muscle composition and have repeatedly shown superior sensitivity over standard functional evaluation. This outcome measure will more than likely be the first of the series to be validated as an endpoint by regulatory agencies. The versatility of contrast generated by NMR has opened many additional possibilities for characterization of the skeletal muscle and will result in the proposal of more NMR biomarkers. Ultra-short TE (UTE) sequences, late gadolinium enhancement and NMR elastography are being investigated as candidates to evaluate skeletal muscle interstitial fibrosis. Many options exist to measure muscle perfusion and oxygenation by NMR. Diffusion NMR as well as texture analysis algorithms could generate complementary information on muscle organization at microscopic and mesoscopic scales, respectively. 31P NMR spectroscopy is the reference technique to assess muscle energetics non-invasively during and

  16. Simultaneous determination of estrogens (ethinylestradiol and norgestimate) concentrations in human and bovine serum albumin by use of fluorescence spectroscopy and multivariate regression analysis.

    PubMed

    Hordge, LaQuana N; McDaniel, Kiara L; Jones, Derick D; Fakayode, Sayo O

    2016-05-15

    The endocrine disruption property of estrogens necessitates the immediate need for effective monitoring and development of analytical protocols for their analyses in biological and human specimens. This study explores the first combined utility of a steady-state fluorescence spectroscopy and multivariate partial-least-square (PLS) regression analysis for the simultaneous determination of two estrogens (17α-ethinylestradiol (EE) and norgestimate (NOR)) concentrations in bovine serum albumin (BSA) and human serum albumin (HSA) samples. The influence of EE and NOR concentrations and temperature on the emission spectra of EE-HSA EE-BSA, NOR-HSA, and NOR-BSA complexes was also investigated. The binding of EE with HSA and BSA resulted in increase in emission characteristics of HSA and BSA and a significant blue spectra shift. In contrast, the interaction of NOR with HSA and BSA quenched the emission characteristics of HSA and BSA. The observed emission spectral shifts preclude the effective use of traditional univariate regression analysis of fluorescent data for the determination of EE and NOR concentrations in HSA and BSA samples. Multivariate partial-least-squares (PLS) regression analysis was utilized to correlate the changes in emission spectra with EE and NOR concentrations in HSA and BSA samples. The figures-of-merit of the developed PLS regression models were excellent, with limits of detection as low as 1.6×10(-8) M for EE and 2.4×10(-7) M for NOR and good linearity (R(2)>0.994985). The PLS models correctly predicted EE and NOR concentrations in independent validation HSA and BSA samples with a root-mean-square-percent-relative-error (RMS%RE) of less than 6.0% at physiological condition. On the contrary, the use of univariate regression resulted in poor predictions of EE and NOR in HSA and BSA samples, with RMS%RE larger than 40% at physiological conditions. High accuracy, low sensitivity, simplicity, low-cost with no prior analyte extraction or separation

  17. High Resolution NMR ^15N and ^31P NMR Of Antiferroelectric Phase Transition in Ammonium Dihydrogen Arsenate and Ammonium Dihydrogen Phosphate

    NASA Astrophysics Data System (ADS)

    Gunaydin-Sen, Ozge

    2005-03-01

    Natural abundance ^15N CPMAS NMR has been used to investigate the paraelectric-antiferroelectric phase transition of NH4H2AsO4 (ADA) (TN˜216K) and of NH4H2PO4 (ADP) (148K), with a focus on the role of the NH4^+ ion. Isotropic chemical shift of ^15N for ADA exhibits an almost linear temperature dependence to within TN±1K, and then changes discontinuously, followed by another almost linear dependence. The spectra of the paraelectric and antiferroelectric phases coexist around the TN. The sharp anomaly around TN implies that the NH4^+ ions undergo a displacive transition, whereas the protons in the O-HO bonds undergo an order-disorder transition. The ^15N data thus support a mixed order-disorder-displacive mechanism for this transition. The ^15N data on ADP exhibit somewhat different behavior. ^31P CPMAS measurements will also be presented and discussed in terms of the above model.

  18. β,γ-CHF- and β,γ-CHCl-dGTP diastereomers: synthesis, discrete 31P NMR signatures and absolute configurations of new stereochemical probes for DNA polymerases

    PubMed Central

    Wu, Yue; Zakharova, Valeria M.; Kashemirov, Boris A.; Goodman, Myron F.; Batra, Vinod K.; Wilson, Samuel H.; McKenna, Charles E.

    2012-01-01

    Deoxynucleoside 5′-triphosphate analogues in which the β,γ-bridging oxygen has been replaced with a CXY group are useful chemical probes to investigate DNA polymerase catalytic and base selection mechanisms. A limitation of such probes has been that conventional synthetic methods generate a mixture of diastereomers when the bridging carbon substitution is non-equivalent (X ≠ Y). We report here a general solution to this long-standing problem with four examples of individual β,γ-CXY dNTP diastereomers: (S)- and (R)-β,γ-CHCl dGTP (12a-1, 12a-2) and (S)- and (R)-β,γ-CHF dGTP (12b-1, 12b-2). Central to their preparation was conversion of the achiral parent bisphosphonic acids to P,C-dimorpholinamide derivatives (7) of their (R)-mandelic acid monoesters (6), which provided access to the individual diastereomers 7a-1, 7a-2, 7b-1, and 7b-2 by preparative HPLC. Selective acidic hydrolysis of the P-N bond then afforded the “ portal ” diastereomers 10, which were readily coupled to morpholine-activated dGMP. Removal of the chiral auxiliary by H2 (Pd/C) afforded the four individual diastereomeric nucleotides (12), which were characterized by 31P, 1H and 19F NMR, and by MS. After treatment with Chelex®-100 to remove traces of paramagnetic ions, at pH ~10 the diastereomer pairs 12a and 12b exhibit discrete Pα and Pβ 31P resonances. The more upfield Pα and more downfield Pβ resonances (and also the more upfield 19F NMR resonance in 12b) are assigned to the (R) configuration at the Pβ-CHX-Pγ carbons, based on the absolute configurations of the individual diastereomers as determined by X-ray crystallographic structures of their ternary complexes with DNA-pol β. PMID:22397499

  19. Concurrent quantification of tissue metabolism and blood flow via 2H/31P NMR in vivo. III. Alterations of muscle blood flow and metabolism during sepsis.

    PubMed

    Song, S K; Hotchkiss, R S; Karl, I E; Ackerman, J J

    1992-05-01

    In the conclusion of this series of reports, the application of 31P/2H NMR to investigate the pathophysiology of sepsis in rat hindlimb muscle is demonstrated. Sepsis decreased muscle [PCr] by 18%, 18 +/- 4 SD vs 22 +/- 4 SD mmol/kg tissue wet wt (P = 0.01) in control rats but [ATP] was unchanged, 6 mmol/kg tissue wet wt (P = 0.2). The derived free cytosolic [ADP] in the two groups was similar, [ADP]septic = 0.023 +/- 0.004 SD and [ADP]control = 0.021 +/- 0.003 SD mmol/kg tissue wet wt, and not statistically different (P = 0.14). Likewise [Pi] in the septic and control groups was not statistically different, [Pi]septic = 1.1 +/- 0.5 SD and [Pi]control = 1.2 +/- 0.4 SD mmol/kg tissue wet wt (P = 0.2). Septic rats presented the symptom of respiratory alkalosis evidenced by elevated blood pH. Sepsis decreased muscle blood flow by 33%, P = 0.003, but examination of individual subjects did not demonstrate a correlation with the reduction in [PCr]. Thus, a metabolic energy deficit caused by cellular ischemia/hypoxia is not a likely cause of cellular abnormality in rat hindlimb muscle during sepsis.

  20. Structural investigations of Pu{sup III} phosphate by X-ray diffraction, MAS-NMR and XANES spectroscopy

    SciTech Connect

    Popa, Karin; Raison, Philippe E.; Martel, Laura; Martin, Philippe M.; Solari, Pier L.; Bouëxière, Daniel; Konings, Rudy J.M.; Somers, Joseph

    2015-10-15

    PuPO{sub 4} was prepared by a solid state reaction method and its crystal structure at room temperature was solved by powder X-ray diffraction combined with Rietveld refinement. High resolution XANES measurements confirm the +III valence state of plutonium, in agreement with valence bond derivation. The presence of the americium (as β{sup −} decay product of plutonium) in the +III oxidation state was determined based on XANES spectroscopy. High resolution solid state {sup 31}P NMR agrees with the XANES results and the presence of a solid-solution. - Graphical abstract: A full structural analysis of PuPO{sub 4} based on Rietveld analysis of room temperature X-ray diffraction data, XANES and MAS NMR measurements was performed. - Highlights: • The crystal structure of PuPO{sub 4} monazite is solved. • In PuPO{sub 4} plutonium is strictly trivalent. • The presence of a minute amount of Am{sup III} is highlighted. • We propose PuPO{sub 4} as a potential reference material for spectroscopic and microscopic studies.

  1. Localized Spectroscopy from Anatomically Matched Compartments: Improved Sensitivity and Localization for Cardiac 31P MRS in Humans

    NASA Astrophysics Data System (ADS)

    Löffler, Ralf; Sauter, Rolf; Kolem, Heinrich; Haase, Axel; von Kienlin, Markus

    1998-10-01

    Several pioneering studies have demonstrated that localized31P NMR spectroscopy of the human heart might become an important diagnostic tool in cardiology. The main limitation is due to the low sensitivity of these experiments, allowing only crude spatial resolution. We have implemented a three-dimensional version of SLOOP ("spectral localization with optimal pointspread function") on a clinical instrument. SLOOP takes advantage of all availablea prioriinformation to match the size and the shape of the sensitive volumes to the anatomical structures in the examined subject. Thus, SLOOP reduces the contamination from adjacent organs and improves the sensitivity compared to conventional techniques such as ISIS or chemical shift imaging (CSI). Initial studies were performed on six healthy volunteers at 1.5 T. The good localization properties are demonstrated by the absence of resonances from blood in the heart spectra, and by PCr-free spectra from the liver. Compared to conventional CSI, the signal-to-noise ratio of the SLOOP heart spectra was improved by approximately 30%. Taking into account the varying excitation angle in the inhomogeneous B1field of the surface coil, the SLOOP model computes the local spin saturation at every point in space. Therefore, no global saturation correction is required in the quantitative evaluation of local spectra. In this study, we found a PCr/γ-ATP ratio in the left ventricular wall of 1.90 ± 0.33 (mean ± standard deviation).

  2. Simultaneous determination of propranolol and amiloride in synthetic binary mixtures and pharmaceutical dosage forms by synchronous fluorescence spectroscopy: a multivariate approach

    NASA Astrophysics Data System (ADS)

    Divya, O.; Shinde, Mandakini

    2013-07-01

    A multivariate calibration model for the simultaneous estimation of propranolol (PRO) and amiloride (AMI) using synchronous fluorescence spectroscopic data has been presented in this paper. Two multivariate techniques, PCR (Principal Component Regression) and PLSR (Partial Least Square Regression), have been successfully applied for the simultaneous determination of AMI and PRO in synthetic binary mixtures and pharmaceutical dosage forms. The SF spectra of AMI and PRO (calibration mixtures) were recorded at several concentrations within their linear range between wavelengths of 310 and 500 nm at an interval of 1 nm. Calibration models were constructed using 32 samples and validated by varying the concentrations of AMI and PRO in the calibration range. The results indicated that the model developed was very robust and able to efficiently analyze the mixtures with low RMSEP values.

  3. A novel method for simultaneous determination of selected elements in dolomite and magnesia by Inductively Coupled Plasma Atomic Emission Spectroscopy with slurry sample introduction

    NASA Astrophysics Data System (ADS)

    Bok-Badura, Joanna; Jakóbik-Kolon, Agata; Turek, Marian; Szczerba, Jacek; Lemanowicz, Marcin; Karoń, Krzysztof

    2015-11-01

    The slurry nebulization ICP-AES method for simultaneous determination of selected elements in dolomite and magnesia was proposed. Based on the investigation results the optimal conditions for this analysis were as follows: particle size < 40 μm, the nitric acid concentration 10%, the RF power 1.0 kW, aqueous solutions (no dispersing agents) and mixing on magnetic stirrer, during the sample introduction into plasma, as homogenization method. The certified reference materials Dolomite CRM 782-1 and High Purity Magnesia BCS-CRM 389/1 were analyzed. Student's t-test proved that there were no statistically significant differences between determined values and the certified ones. This proves that the slurry sample introduction into plasma in ICP-AES technique can be applied for simultaneous determination of elements in dolomite and magnesia.

  4. Batch and continuous flow preparation of Hantzsch 1,4-dihydropyridines under microwave heating and simultaneous real-time monitoring by Raman spectroscopy. An exploratory study.

    PubMed

    Christiaens, Sylvain; Vantyghem, Xavier; Radoiu, Marilena; Vanden Eynde, Jean Jacques

    2014-07-09

    Dialkyl 1,4-dihydro-2,6-dimethylpyridine-3,5-dicarboxylates have been prepared in a batch mode under conventional heating as well as under continuous flow conditions in the Miniflow 200SS, Sairem's microwave-assisted batch and continuous flow equipment. Real-time monitoring of the reactions by Raman spectroscopy enabled to compare both heating modes and to determine (optimized) reaction times.

  5. Simultaneous determination of amino acid nitrogen and total acid in soy sauce using near infrared spectroscopy combined with characteristic variables selection.

    PubMed

    Zhao, Jiewen; Ouyang, Qin; Chen, Quansheng; Lin, Hao

    2013-08-01

    Amino acid nitrogen and total acid are two most important quality indices to assess the quality of soy sauce in China. This work employed near infrared spectroscopy combined with synergy interval partial least square and genetic algorithm to detect amino acid nitrogen and total acid content in soy sauce. First, synergy interval partial least square was used to select efficient spectral regions from the full spectrum region; and then, genetic algorithm was used to selected variables from the efficient spectral regions, to build partial least square model. The optimal genetic algorithm synergy interval partial least square models were obtained as follows: Rc  = 0.9988 and Rp = 0.9988 for amino acid nitrogen content model using 64 variables; Rc = 0.9917 and Rp = 0.9902 for total acid content model using 81 variables. Genetic algorithm synergy interval partial least square models showed superiority over the partial least square and synergy interval partial least square models. The results indicated that amino acid nitrogen and total acid content in soy sauce could be rapidly determined by near infrared spectroscopy technique. Also, the results indicated that genetic algorithm synergy interval partial least square can improve the performance in measurement of amino acid nitrogen and total acid content by near infrared spectroscopy.

  6. Simultaneous monitoring of nitric oxide, oxyhemoglobin and deoxyhemoglobin from small areas of the rat brain by in vivo visible spectroscopy and a least-square approach.

    PubMed

    Martín, Felipe A; Rojas-Díaz, David; Luis-García, M A Luz; González-Mora, Jose L; Castellano, Miguel A

    2004-12-30

    Nitric oxide (NO) is a versatile molecule involved in a wide range of biological processes. Under physiological conditions, NO reacts with oxyhemoglobin (OxyHb) to form methemoglobin (MetHb) at a very high rate. Previous works have shown that MetHb is proportional to NO and that MetHb absorption contributes to the in vivo absorption spectrum recorded with visible spectroscopy using optical fibers. However, in vivo spectrophotometric monitoring of a single molecule has long been a problem because the overlapping of OxyHb, deoxyhemoglobin (DeoxyHb), MetHb, cytochromes and other chromophores absorption spectra make in vivo quantitative spectroscopy difficult. The aim of this work was to evaluate the possibility of obtaining the contribution of each main endogenous chromophore, especially OxyHb, DeoxyHb and MetHb, to the in vivo visible absorption spectrum recorded from rat cortex, hippocampus and striatum. A least-square approach with a fitting equation containing the in vitro spectrum of the main endogenenous chromophores was used. The validity of this approach was studied by increasing the endogenous MetHb level with NO infusion and by biliverdin perfusion. Data indicate that in vivo visible spectroscopy in combination with the least-square fitting method may be a useful tool for gaining insight into the roles of NO, hemoglobins and the interaction between them even from small cerebral areas.

  7. Dynamics of asymmetric binary glass formers. I. A dielectric and nuclear magnetic resonance spectroscopy study

    SciTech Connect

    Kahlau, R.; Bock, D.; Schmidtke, B.; Rössler, E. A.

    2014-01-28

    Dielectric spectroscopy as well as {sup 2}H and {sup 31}P nuclear magnetic resonance spectroscopy (NMR) are applied to probe the component dynamics of the binary glass former tripropyl phosphate (TPP)/polystyrene (PS/PS-d{sub 3}) in the full concentration (c{sub TPP}) range. In addition, depolarized light scattering and differential scanning calorimetry experiments are performed. Two glass transition temperatures are found: T{sub g1}(c{sub TPP}) reflects PS dynamics and shows a monotonic plasticizer effect, while the lower T{sub g2}(c{sub TPP}) exhibits a maximum and is attributed to (faster) TPP dynamics, occurring in a slowly moving or immobilized PS matrix. Dielectric spectroscopy probing solely TPP identifies two different time scales, which are attributed to two sub-ensembles. One of them, again, shows fast TPP dynamics (α{sub 2}-process), the other (α{sub 1}-process) displays time constants identical with those of the slow PS matrix. Upon heating the α{sub 1}-fraction of TPP decreases until above some temperature T{sub c} only a single α{sub 2}-population exists. Inversely, below T{sub c} a fraction of the TPP molecules is trapped by the PS matrix. At low c{sub TPP} the α{sub 2}-relaxation does not follow frequency-temperature superposition (FTS), instead it is governed by a temperature independent distribution of activation energies leading to correlation times which follow Arrhenius laws, i.e., the α{sub 2}-relaxation resembles a secondary process. Yet, {sup 31}P NMR demonstrates that it involves isotropic reorientations of TPP molecules within a slowly moving or rigid matrix of PS. At high c{sub TPP} the super-Arrhenius temperature dependence of τ{sub 2}(T), as well as FTS are recovered, known as typical of the glass transition in neat systems.

  8. Simultaneous UV and X-ray Spectroscopy of the Seyfert 1 Galaxy NGC 5548. I: Physical Conditions in the UV Absorbers

    NASA Technical Reports Server (NTRS)

    Crenshaw, D. M.; Kraemer, S. B.; Gabel, J. R.; Kaastra, J. S.; Steenbrugge, K. C.; Brinkman, A. C.; Dunn, J. P.; George, I. M.; Liedahl, D. A.; Paerels, F. B. S.

    2003-01-01

    We present new UV spectra of the nucleus of the Seyfert 1 galaxy NGC 5548, which we obtained with the Space Telescope Imaging Spectrograph at high spectral resolution, in conjunction with simultaneous Chandra X-ray Observatory spectra. Taking advantage of the low UV continuum and broad emission-line fluxes, we have determined that the deepest UV absorption component covers at least a portion of the inner, high-ionization narrow-line region (NLR). We find nonunity covering factors in the cores of several kinematic components, which increase the column density measurements of N V and C IV by factors of 1.2 to 1.9 over the full-covering case; however, the revised columns have only a minor effect on the parameters derived from our photoionization models. For the first time, we have simultaneous N V and C IV columns for component 1 (at -1040 km/s), and find that this component cannot be an X-ray warm absorber, contrary to our previous claim based on nonsimultaneous observations. We find that models of the absorbers based on solar abundances severely overpredict the O VI columns previously obtained with the Far Ultraviolet Spectrograph, and present arguments that this is not likely due to variability. However, models that include either enhanced nitrogen (twice solar) or dust, with strong depletion of carbon in either case, are successful in matching all of the observed ionic columns. These models result in substantially lower ionization parameters and total column densities compared to dust-free solar-abundance models, and produce little O VII or O VIII, indicating that none of the UV absorbers are X-ray warm absorbers.

  9. Simultaneous determination of arsenic, cadmium, copper, chromium, nickel, lead and thallium in total digested sediment samples and available fractions by electrothermal atomization atomic absorption spectroscopy (ET AAS).

    PubMed

    Álvarez, María Á; Carrillo, Génesis

    2012-08-15

    This study describes the optimization and validation of a quick and simple method for the simultaneous determination of total content and available fractions of As, Cr, Cu, Ni, Pb and Tl in sediments by ET AAS, which has been proved to be useful for environmental research. The optimization was carried out using a 3(3) Box-Behnken factorial design which was applied to matrices of total digestion and to stages 1 and 2 of the modified BCR sequential extraction scheme for sediments in order to determine the appropriate atomization temperatures and masses for the chemical modifiers: Pd(NO(3))(2) and Mg(NO(3))(2). The simultaneous determination of the elements in all matrices considered was performed, without the use of chemical modifiers at atomization temperatures of 1700 °C for Cd and Tl, and 2100 °C for As, Cu, Cr, Ni and Pb, using a standard calibration curve for calibration purposes. The characteristic masses and limits of detection obtained were 36.5, 1.8, 6.5, 28, 34, 46.5 and 48 ρg and 0.11, 0.001, 0.022, 0.04, 0.2, 0.03 and 0.003 μg g(-1) for As, Cd, Cr, Cu, Ni, Pb and Tl, respectively. The analytical procedure was validated by analyzing three sediment certified reference materials (CRM NCS DC 73315 and LKSD-4 for total content and BCR 701 for available fractions). Good accuracy was obtained (tested statistically, P=0.05, and shown by the high recovery for each element in each matrix), except for total As in the matrix of total digestion, where losses of the analyte could be attributed to sample treatment with HNO(3). The precision of the procedure was between 0.6% and 6%.

  10. A quint-wavelength UV spectroscopy for simultaneous determination of dichlorobenzene, chlorobenzene, and benzene in simulated water reduced by nanoscale zero-valent Fe/Ni bimetal.

    PubMed

    Wan, Xiaofang; Liu, Yu; Chai, Xin-Sheng; Li, Youming; Guo, Congbao

    2017-03-18

    A quint-wavelength UV spectroscopy for rapid determination of dichlorobenzene (DCB), chlorobenzene (CB) and benzene (B) was developed for the dechlorination process of DCB reduced by nanoscale zero-valent Fe/Ni bimetal. Based on the absorbance measurements at 260, 269, 277, 290 and 300nm, the equations for calculating the concentration of DCB and CB and B were established, in which the spectral interference from the nanoparticles could be effectively minimized. The results show that the present method has a good measurement precision (the relative standard deviations are within 2.0%) and accuracy (the recoveries are between 89 and 111%) in the DCB, CB and B's quantification. The present method is simple, rapid, and such a methodology is very suitable to be used for evaluating the dechlorination performance of chlorinated aromatic compounds in the presence of bimetal nanoparticle.

  11. Towards simultaneous measurements of electronic and structural properties in ultra-fast x-ray free electron laser absorption spectroscopy experiments

    SciTech Connect

    Gaudin, J.; Fourment, C.; Cho, B. I.; Engelhorn, K.; Galtier, E.; Harmand, M.; Leguay, P. M.; Lee, H. J.; Nagler, B.; Nakatsutsumi, M.; Ozkan, C.; Störmer, M.; Toleikis, S.; Tschentscher, Th.; Heimann, P. A.; Dorchies, F.

    2014-04-17

    The rapidly growing ultrafast science with X-ray lasers unveils atomic scale processes with unprecedented time resolution bringing the so called “molecular movie” within reach. X-ray absorption spectroscopy is one of the most powerful x-ray techniques providing both local atomic order and electronic structure when coupled with ad-hoc theory. Collecting absorption spectra within few x-ray pulses is possible only in a dispersive setup. We demonstrate ultrafast time-resolved measurements of the LIII-edge x-ray absorption near-edge spectra of irreversibly laser excited Molybdenum using an average of only few x-ray pulses with a signal to noise ratio limited only by the saturation level of the detector. The simplicity of the experimental set-up makes this technique versatile and applicable for a wide range of pump-probe experiments, particularly in the case of non-reversible processes.

  12. Towards simultaneous measurements of electronic and structural properties in ultra-fast x-ray free electron laser absorption spectroscopy experiments

    DOE PAGES

    Gaudin, J.; Fourment, C.; Cho, B. I.; ...

    2014-04-17

    The rapidly growing ultrafast science with X-ray lasers unveils atomic scale processes with unprecedented time resolution bringing the so called “molecular movie” within reach. X-ray absorption spectroscopy is one of the most powerful x-ray techniques providing both local atomic order and electronic structure when coupled with ad-hoc theory. Collecting absorption spectra within few x-ray pulses is possible only in a dispersive setup. We demonstrate ultrafast time-resolved measurements of the LIII-edge x-ray absorption near-edge spectra of irreversibly laser excited Molybdenum using an average of only few x-ray pulses with a signal to noise ratio limited only by the saturation level ofmore » the detector. The simplicity of the experimental set-up makes this technique versatile and applicable for a wide range of pump-probe experiments, particularly in the case of non-reversible processes.« less

  13. Selective Alcohol Oxidation by a Copper TEMPO Catalyst: Mechanistic Insights by Simultaneously Coupled Operando EPR/UV-Vis/ATR-IR Spectroscopy.

    PubMed

    Rabeah, Jabor; Bentrup, Ursula; Stößer, Reinhard; Brückner, Angelika

    2015-09-28

    The first coupled operando EPR/UV-Vis/ATR-IR spectroscopy setup for mechanistic studies of gas-liquid phase reactions is presented and exemplarily applied to the well-known copper/TEMPO-catalyzed (TEMPO=(2,2,6,6-tetramethylpiperidin-1-yl)oxyl) oxidation of benzyl alcohol. In contrast to previous proposals, no direct redox reaction between TEMPO and Cu(I) /Cu(II) has been detected. Instead, the role of TEMPO is postulated to be the stabilization of a (bpy)(NMI)Cu(II) -O2 (⋅-) -TEMPO (bpy=2,2'-bipyridine, NMI=N-methylimidazole) intermediate formed by electron transfer from Cu(I) to molecular O2 .

  14. Simultaneous measurement of nitrogen and hydrogen dissociation from vacuum ultraviolet self-absorption spectroscopy in a developing low temperature plasma at atmospheric pressure

    SciTech Connect

    Laity, George; Fierro, Andrew; Dickens, James; Neuber, Andreas; Frank, Klaus

    2013-05-06

    We demonstrate a method for determining the dissociation density of N and H atoms present in a developing low temperature plasma, based on the emission and self-absorption of vacuum ultraviolet radiation produced from the plasma. Spark plasmas are produced via pulsed discharge in N{sub 2}/H{sub 2} mixtures at atmospheric pressure, where information on the dissociated densities of the constituent gas molecules is desired without employing invasive diagnostic techniques. By analyzing the self-absorption line profile of 121.5 nm Lyman-{alpha} H radiation emitted within the first {approx}1.0 mm of plasma near the anode tip, a peak dissociated H atom concentration of 5.6 Multiplication-Sign 10{sup 17} cm{sup -3} was observed {approx}100 ns into spark formation, with an estimated electron density of 2.65 Multiplication-Sign 10{sup 18} cm{sup -3} determined from Stark broadening. Similarly, simultaneous line fitting of the N 120.0/124.3 nm emission profiles revealed a peak dissociated N atom concentration of 3.8 Multiplication-Sign 10{sup 17} cm{sup -3} during the same discharge period.

  15. Simultaneous measurements of atmospheric HONO and NO2 via absorption spectroscopy using tunable mid-infrared continuous-wave quantum cascade lasers

    NASA Astrophysics Data System (ADS)

    Lee, B. H.; Wood, E. C.; Zahniser, M. S.; McManus, J. B.; Nelson, D. D.; Herndon, S. C.; Santoni, G. W.; Wofsy, S. C.; Munger, J. W.

    2011-02-01

    Nitrous acid (HONO) is important as a significant source of hydroxyl radical (OH) in the troposphere and as a potent indoor air pollutant. It is thought to be generated in both environments via heterogeneous reactions involving nitrogen dioxide (NO2). In order to enable fast-response HONO detection suitable for eddy-covariance flux measurements and to provide a direct method that avoids interferences associated with derivatization, we have developed a 2-channel tunable infrared laser differential absorption spectrometer (TILDAS) capable of simultaneous high-frequency measurements of HONO and NO2. Beams from two mid-infrared continuous-wave mode quantum cascade lasers (cw-QCLs) traverse separate 210 m paths through a multi-pass astigmatic sampling cell at reduced pressure for the direct detection of HONO (1660 cm-1) and NO2 (1604 cm-1). The resulting one-second detection limits (S/N=3) are 300 and 30 ppt (pmol/mol) for HONO and NO2, respectively. Our HONO quantification is based on revised line-strengths and peak positions for cis-HONO in the 6-micron spectral region that were derived from laboratory measurements. An essential component of ambient HONO measurements is the inlet system and we demonstrate that heated surfaces and reduced pressure minimize sampling artifacts.

  16. Chemometrics-assisted excitation-emission fluorescence spectroscopy on nylon-attached rotating disks. Simultaneous determination of polycyclic aromatic hydrocarbons in the presence of interferences.

    PubMed

    Cañas, Alejandro; Richter, Pablo; Escandar, Graciela M

    2014-12-10

    This work presents a green and very simple approach which enables the accurate and simultaneous determination of benzo[a]pyrene, dibenz[a,h]anthracene, benz[a]anthracene, and chrysene, concerned and potentially carcinogenic heavy-polycyclic aromatic hydrocarbons (PAHs) in interfering samples. The compounds are extracted from water samples onto a device composed of a small rotating Teflon disk, with a nylon membrane attached to one of its surfaces. After extraction, the nylon membrane containing the concentrated analytes is separated from the Teflon disk, and fluorescence excitation-emission matrices are directly measured on the nylon surface, and processed by applying parallel factor analysis (PARAFAC), without the necessity of a desorption step. Under optimum conditions and for a sample volume of 25 mL, the PAHs extraction was carried out in 20 min. Detection limits based on the IUPAC recommended criterion and relative errors of prediction were in the ranges 20-100 ng L(-1) and 5-7%, respectively. Thanks to the combination of the ability of nylon to strongly retain PAHs, the easy rotating disk extraction approach, and the selectivity of second-order calibration, which greatly simplifies sample treatment avoiding the use of toxic solvents, the developed method follows most green analytical chemistry principles.

  17. Utility of surface enhanced Raman spectroscopy (SERS) for elucidation and simultaneous determination of some penicillins and penicilloic acid using hydroxylamine silver nanoparticles.

    PubMed

    El-Zahry, Marwa R; Refaat, Ibrahim H; Mohamed, Horria A; Rosenberg, Erwin; Lendl, Bernhard

    2015-11-01

    Elucidation and quantitative determination of some of commonly used penicillins (ampicillin, penicillin G and carbenicillin) in the presence of their main degradation product (penicilloic acid) were developed. Forced acidic and basic degradation processes were applied at different time intervals. The formed degradation products were elucidated and quantified using surface enhanced Raman spectroscopy (SERS). Silver nanoparticles (AgNPs) prepared by reduction of silver nitrate using hydroxylamine-HCl in alkaline medium were used as SERS substrate. The results obtained in SERS were confirmed by the application of LC/MS method. The concentration range was 100-600 ng/ml in case of the studied penicillins and 100-700 ng/ml in case of penicilloic acid. An excellent correlation coefficient was found in case of ampicillin (r=0.9993) and in the case of penicilloic acid (r=0.9997). Validation procedures were carried out including precision, robustness and accuracy by comparing F- and t-values of both the proposed and reported methods.

  18. High pressure in situ x-ray absorption spectroscopy cell for studying simultaneously the liquid phase and the solid-liquid interface

    SciTech Connect

    Grunwaldt, Jan-Dierk; Ramin, Michael; Rohr, Markus; Michailovski, Alexej; Patzke, Greta R.; Baiker, Alfons

    2005-05-15

    A high pressure in situ x-ray absorption spectroscopy cell with two different path lengths and path positions is presented for studying element-specifically both the liquid phase and the solid-liquid interface at pressures up to 250 bar and temperatures up to 220 deg. C. For this purpose, one x-ray path probes the bottom, while the other x-ray path penetrates through the middle of the in situ cell. The basic design of the cell resembles a 10 ml volume batch reactor, which is equipped with in- and outlet lines to dose compressed gases and liquids as well as a stirrer for good mixing. Due to the use of a polyetheretherketone inset it is also suitable for measurements under corrosive conditions. The characteristic features of the cell are illustrated using case studies from catalysis and solid state chemistry: (a) the ruthenium-catalyzed formylation of an amine in 'supercritical' carbon dioxide in the presence of hydrogen; (b) the cycloaddition of carbon dioxide to propylene oxide in the presence of a solid Zn-based catalyst, and (c) the solvothermal synthesis of MoO{sub 3} nanorods from MoO{sub 3}-2H{sub 2}O.

  19. Design of Selenium-Based Chiral Chemical Probes for Simultaneous Enantio- and Chemosensing of Chiral Carboxylic Acids with Remote Stereogenic Centers by NMR Spectroscopy.

    PubMed

    Shyshkanov, Sergey A; Orlov, Nikolai V

    2016-10-17

    Selenium-based enantiopure chiral chemical probes have been designed in a modular way starting from available amino alcohols. The probes developed were found to be efficient in chemoselective interaction with carboxylic functions of chiral substrates leading to diastereomeric amide formation and in sensing α-, β-, and remote (up to seven bonds away from the carboxylic group) chiral centers by using (77) Se NMR spectroscopy. As a result, it was possible to determine the enantiomeric ratio of structurally diverse individual chiral acids including polyfunctional compounds and drugs with high accuracy. An approach to analyzing the crude reaction mixtures has been successfully developed by using bifunctional selenium- and fluorine-containing chiral probes. More importantly, it was revealed that, based on the (77) Se NMR data obtained, it is possible to obtain primary information about the location and nature of the substituents at the chiral center (chemo- and enantiosensing), which can simplify the structural elucidation of complex compounds. The derivatization procedure takes as little as 5 min and can be performed directly in an NMR tube followed by NMR measurements without any isolation and purification steps.

  20. High pressure in situ x-ray absorption spectroscopy cell for studying simultaneously the liquid phase and the solid/liquid interface

    NASA Astrophysics Data System (ADS)

    Grunwaldt, Jan-Dierk; Ramin, Michael; Rohr, Markus; Michailovski, Alexej; Patzke, Greta R.; Baiker, Alfons

    2005-05-01

    A high pressure in situ x-ray absorption spectroscopy cell with two different path lengths and path positions is presented for studying element-specifically both the liquid phase and the solid/liquid interface at pressures up to 250 bar and temperatures up to 220 °C. For this purpose, one x-ray path probes the bottom, while the other x-ray path penetrates through the middle of the in situ cell. The basic design of the cell resembles a 10 ml volume batch reactor, which is equipped with in- and outlet lines to dose compressed gases and liquids as well as a stirrer for good mixing. Due to the use of a polyetheretherketone inset it is also suitable for measurements under corrosive conditions. The characteristic features of the cell are illustrated using case studies from catalysis and solid state chemistry: (a) the ruthenium-catalyzed formylation of an amine in "supercritical" carbon dioxide in the presence of hydrogen; (b) the cycloaddition of carbon dioxide to propylene oxide in the presence of a solid Zn-based catalyst, and (c) the solvothermal synthesis of MoO3 nanorods from MoO3•2H2O.

  1. Thermal decomposition studies of 1,3,3-trinitroazetidine (TNAZ) and 1-nitroso-3,3-dinitroazetidine (NDNAZ) by simultaneous thermogravimetric modulated beam mass spectroscopy

    SciTech Connect

    Behrens, R. Jr.; Bulusu, S.

    1995-12-01

    The initial results from a study of the thermal decomposition of TNAZ, TNAZ-1-{sup 15}NO{sub 2} and NDNAZ using the simultaneous thermogravimetric modulated beam mass spectrometer (STMBMS) are presented. The major products formed in the decomposition of TNAZ are NO{sub 2} and NO with slightly lesser amounts of H{sub 2}O, HCN, CO/N{sub 2}, CO{sub 2}/N{sub 2}O and NDNAZ. The major product formed in the decomposition of NDNAZ is NO with lesser amounts of H{sub 2}O, HCN, CO/N{sub 2}O. The lower molecular weight products are similar to those observed in RSFTIR and IRMPD studies conducted previously by others. However, this study has shown that the mononitroso analogue of TNAZ, NDNAZ, is an important intermediate formed during the decomposition of TNAZ. It plays an important role in determining the identity of the products formed in the decomposition of TNAZ. The temporal behaviors Of the ion signals associated with the various thermal decomposition products from TNAZ, TNAZ-1-{sup 15}NO{sub 2} and NDNAZ are also presented. The illustrate the evolution sequence of the various products that are associated with the different reaction pathways that control the decomposition of these materials. In particular, the study of the {sup 15}N-labeled sample revealed that NO{sub 2} originates from both the likely sites in the TNAZ molecule and that the cleavage of the nitramine-NO{sub 2} group precedes that of the C-NO{sub 2} cleavage, resulting in similar sequences in the formation of NO and NDNAZ also.

  2. Development and application of a membrane cyclone reactor for in vivo NMR spectroscopy with high microbial cell densities.

    PubMed

    Hartbrich, A; Schmitz, G; Weuster-Botz, D; de Graaf, A A; Wandrey, C

    1996-09-20

    A new bioreactor system has been developed for in vivo NMR spectroscopy of microorganisms under defined physiological conditions. This cyclone reactor with an integrated NMR flow cell is continuously operated in the magnet of a 400-MHz wide-bore NMR spectrometer system. The residence times of medium and cells are decoupled by a circulation-integrated cross-flow microfiltration module to achieve higher cell densities as compared to continuous fermentations without cell retention (increase in cell density up to a factor of 10 in steady state). Volumetric mass transfer coefficients k(L)a of more than 1.0 s(-1) are possible in the membrane cyclone reactor, ensuring adequate oxygen supply [oxygen transfer rate >15,000 mg O(2) .(L h)(-1)] of high cell densities. With the aid of the membrane cyclone reactor we were able to show, using continuous in vivo (31)P NMR spectroscopy of anaerobic glucose fermentation by Zymomonas mobilis, that the NMR signal intensity was directly proportional to the cell concentration in the reactor. The concentration profiles of intracellular inorganic phosphate, NAD(H), NDP, NTP, UDP-sugar, a cyclic pyrophosphate, two sugar phosphate pools, and extracellular inorganic phosphate were recorded after a shift from one steady state to another. The intracellular cyclic pyrophosphate had not been detected before in in vitro measurements of Zymomonas mobilis extracts due to the high instability of this compound. Using continuous in vivo (13)C NMR spectroscopy of aerobic glucose utilization by Corynebacterium glutamicum at a density of 25 g(cell dry weight) . L(-1), the membrane cyclone reactor served to measure the different dynamics of labeling in the carbon atoms of L-lactate, L-glutamate, succinate, and L-lysine with a time resolution of 10 min after impressing a [1-(13)C]-glucose pulse.

  3. Wheat germ 5S ribosomal RNA common arm fragment conformations observed by sup 1 H and sup 31 P nuclear magnetic resonance spectroscopy

    SciTech Connect

    Wu, Jiejun; Marshall, A.G. )

    1990-02-20

    The nonexchangeable protons of the common arm fragment of wheat germ (Triticum aestivum) ribosomal 5S RNA have been observed by means of high-resolution 500-MHz {sup 1}H NMR spectroscopy in D{sub 2}O solution. Although NMR studies on the exchangeable protons support the presence of two distinct solution structures of the common arm fragment (and of the same base-paired segment in intact 5S rRNA), only a single conformation is manifested in the {sup 1}H NMR behavior of all of the H6 and H5 pyrimidine and most of the H8/H2 purine protons under the same salt conditions. The nonexchangeable protons near the base-paired helix have been assigned by a sequential strategy. Conformational features such as the presence of a cytidine-uridine (C{center dot}U) pair at the loop-helix junction and base stacking into the hairpin loop are evaluated from nuclear Overhauser enhancement spectroscopy (NOESY) data. Double-quantum filtered correlation spectroscopy (DQF-COSY) experiments show that most of the 26 riboses are in the C3{prime}-endo conformation. Finally, backbone conformational changes induced by Mg{sup 2+} and heating have been monitored by {sup 31}P NMR spectroscopy. The results show that the common arm RNA segment can assume two conformations which produce distinguishably different NMR environments at the base-pair hydrogen-bond imino protons but not at nonexchangeable base or ribose proton or backbone phosphate sites.

  4. Phosphorus speciation in a eutrophic lake by ³¹P NMR spectroscopy.

    PubMed

    Read, Emily K; Ivancic, Monika; Hanson, Paul; Cade-Menun, Barbara J; McMahon, Katherine D

    2014-10-01

    For eutrophic lakes, patterns of phosphorus (P) measured by standard methods are well documented but provide little information about the components comprising standard operational definitions. Dissolved P (DP) and particulate P (PP) represents important but rarely characterized nutrient pools. Samples from Lake Mendota, Wisconsin, USA were characterized using 31-phosphorus nuclear magnetic resonance spectroscopy ((31)P NMR) during the open water season of 2011 in this unmatched temporal study of aquatic P dynamics. A suite of organic and inorganic P forms was detected in both dissolved and particulate fractions: orthophosphate, orthophosphate monoesters, orthophosphate diesters, pyrophosphate, polyphosphate, and phosphonates. Through time, phytoplankton biomass, temperature, dissolved oxygen, and water clarity were correlated with changes in the relative proportion of P fractions. Particulate P can be used as a proxy for phytoplankton-bound P, and in this study, a high proportion of polyphosphate within particulate samples suggested P should not be a limiting factor for the dominant primary producers, cyanobacteria. Hypolimnetic particulate P samples were more variable in composition than surface samples, potentially due to varying production and transport of sinking particles. Surface dissolved samples contained less P than particulate samples, and were typically dominated by orthophosphate, but also contained monoester, diester, polyphosphate, pyrophosphate, and phosphonate. Hydrologic inflows to the lake contained more orthophosphate and orthophosphate monoesters than in-lake samples, indicating transformation of P from inflowing waters. This time series explores trends of a highly regulated nutrient in the context of other water quality metrics (chlorophyll, mixing regime, and clarity), and gives insight on the variability of the structure and occurrence of P-containing compounds in light of the phosphorus-limited paradigm.

  5. CW EC-QCL-based sensor for simultaneous detection of H2O, HDO, N2O and CH4 using multi-pass absorption spectroscopy

    SciTech Connect

    Yu, Yajun; Sanchez, Nancy P.; Griffin, Robert J.; Tittel, Frank K.

    2016-05-03

    A sensor system based on a continuous wave, external-cavity quantum-cascade laser (CW EC-QCL) was demonstrated for simultaneous detection of atmospheric H2O, HDO, N2O and CH4 using a compact, dense pattern multi-pass gas cell with an effective path-length of 57.6 m. The EC-QCL with a mode-hop-free spectral range of 1225-1285 cm-1 operating at similar to 7.8 mu m was scanned covering four neighboring absorption lines, for H2O at 1281.161 cm-1, HDO at 1281.455 cm-1, N2O at 1281.53 cm-1 and CH4 at 1281.61 cm-1. A first-harmonic-normalized wavelength modulation spectroscopy with second-harmonic detection (WMS-2f/1f) strategy was employed for data processing. An Allan-Werle deviation analysis indicated that minimum detection limits of 1.77 ppmv for H2O, 3.92 ppbv for HDO, 1.43 ppbv for N2O, and 2.2 ppbv for CH4 were achieved with integration times of 50-s, 50-s, 100-s and 129-s, respectively. In conclusion, experimental measurements of ambient air are also reported.

  6. Characterization of phosphorus forms in lake macrophytes and algae by solution (31)P nuclear magnetic resonance spectroscopy.

    PubMed

    Feng, Weiying; Zhu, Yuanrong; Wu, Fengchang; Meng, Wei; Giesy, John P; He, Zhongqi; Song, Lirong; Fan, Mingle

    2016-04-01

    Debris from aquatic macrophytes and algae are important recycling sources of phosphorus (P), which can result in continuing blooms of algae by recycling bioavailable P in the eutrophic lakes. However, knowledge of forms of P in aquatic macrophytes and algae and their contribution to internal loads of P in lakes is limited. Without such knowledge, it is difficult to develop appropriate strategies to remediate and or restore aquatic ecosystems that have become eutrophic. Therefore, in this work, P was extracted from six types of aquatic macrophytes and algae collected from Tai Lake of China and characterized by use of solution (31)P-nuclear magnetic resonance (NMR) spectroscopy. When extracted by 0.5 M NaOH-25 mM EDTA, extraction recovery of total P(TP) and organic P(Po) exceeded 90 %. Concentrations of Po in algae and aquatic macrophytes were 5552 mg kg(-1) and 1005 mg kg(-1) and accounted for 56.0 and 47.2 % of TP, respectively. When Po, including condensed P, was characterized by solution (31)P-NMR Po in algae included orthophosphate monoesters (79.8 %), pyrophosphate (18.2 %), and orthophosphate diester (2.0 %), and Po in aquatic macrophytes included orthophosphate monoesters (90.3 %), pyrophosphate (4.2 %), and orthophosphate diester (5.5 %). Additionally, orthophosphate monoesters in algal debris mainly included β-glycerophosphate (44.1 %), α-glycerophosphate (13.5 %), and glucose 6-phosphate (13.5 %). Orthophosphate monoesters in aquatic macrophytes mainly included β-glycerophosphate (27.9 %), α-glycerophosphate (24.6 %), and adenosine 5' monophosphate (8.2 %). Results derived from this study will be useful in better understanding nutrient cycling, relevant eutrophication processes, and pollution control for freshwater lakes.

  7. Simultaneous high-speed gas property measurements at the exhaust gas recirculation cooler exit and at the turbocharger inlet of a multicylinder diesel engine using diode-laser-absorption spectroscopy.

    PubMed

    Jatana, Gurneesh S; Magee, Mark; Fain, David; Naik, Sameer V; Shaver, Gregory M; Lucht, Robert P

    2015-02-10

    A diode-laser-absorption-spectroscopy-based sensor system was used to perform high-speed (100 Hz to 5 kHz) measurements of gas properties (temperature, pressure, and H(2)O vapor concentration) at the turbocharger inlet and at the exhaust gas recirculation (EGR) cooler exit of a diesel engine. An earlier version of this system was previously used for high-speed measurements of gas temperature and H(2)O vapor concentration in the intake manifold of the diesel engine. A 1387.2 N m tunable distributed feedback diode laser was used to scan across multiple H(2)O absorption transitions, and the direct absorption signal was recorded using a high-speed data acquisition system. Compact optical connectors were designed to conduct simultaneous measurements in the intake manifold, the EGR cooler exit, and the turbocharger inlet of the engine. For measurements at the turbocharger inlet, these custom optical connectors survived gas temperatures as high as 800 K using a simple and passive arrangement in which the temperature-sensitive components were protected from high temperatures using ceramic insulators. This arrangement reduced system cost and complexity by eliminating the need for any active water or oil cooling. Diode-laser measurements performed during steady-state engine operation were within 5% of the thermocouple and pressure sensor measurements, and within 10% of the H(2)O concentration values derived from the CO(2) gas analyzer measurements. Measurements were also performed in the engine during transient events. In one such transient event, where a step change in fueling was introduced, the diode-laser sensor was able to capture the 30 ms change in the gas properties; the thermocouple, on the other hand, required 7.4 s to accurately reflect the change in gas conditions, while the gas analyzer required nearly 600 ms. To the best of our knowledge, this is the first implementation of such a simple and passive arrangement of high-temperature optical connectors as well

  8. Conformation and dynamics of melittin bound to magnetically oriented lipid bilayers by solid-state (31)P and (13)C NMR spectroscopy.

    PubMed Central

    Naito, A; Nagao, T; Norisada, K; Mizuno, T; Tuzi, S; Saitô, H

    2000-01-01

    The conformation and dynamics of melittin bound to the dimyristoylphosphatidylcholine (DMPC) bilayer and the magnetic orientation in the lipid bilayer systems were investigated by solid-state (31)P and (13)C NMR spectroscopy. Using (31)P NMR, it was found that melittin-lipid bilayers form magnetically oriented elongated vesicles with the long axis parallel to the magnetic field above the liquid crystalline-gel phase transition temperature (T(m) = 24 degrees C). The conformation, orientation, and dynamics of melittin bound to the membrane were further determined by using this magnetically oriented lipid bilayer system. For this purpose, the (13)C NMR spectra of site-specifically (13)C-labeled melittin bound to the membrane in the static, fast magic angle spinning (MAS) and slow MAS conditions were measured. Subsequently, we analyzed the (13)C chemical shift tensors of carbonyl carbons in the peptide backbone under the conditions where they form an alpha-helix and reorient rapidly about the average helical axis. Finally, it was found that melittin adopts a transmembrane alpha-helix whose average axis is parallel to the bilayer normal. The kink angle between the N- and C-terminal helical rods of melittin in the lipid bilayer is approximately 140 degrees or approximately 160 degrees, which is larger than the value of 120 degrees determined by x-ray diffraction studies. Pore formation was clearly observed below the T(m) in the initial stage of lysis by microscope. This is considered to be caused by the association of melittin molecules in the lipid bilayer. PMID:10777736

  9. Array-based photoacoustic spectroscopy

    DOEpatents

    Autrey, S. Thomas; Posakony, Gerald J.; Chen, Yu

    2005-03-22

    Methods and apparatus for simultaneous or sequential, rapid analysis of multiple samples by photoacoustic spectroscopy are disclosed. A photoacoustic spectroscopy sample array including a body having at least three recesses or affinity masses connected thereto is used in conjunction with a photoacoustic spectroscopy system. At least one acoustic detector is positioned near the recesses or affinity masses for detection of acoustic waves emitted from species of interest within the recesses or affinity masses.

  10. Simultaneous Monitoring of Vascular Oxygenation and Tissue Oxygen Tension of Breast Tumors under Hyperbaric Oxygen Exposure

    DTIC Science & Technology

    2006-04-01

    FOXY system, on various rat breast tumor size (months 14- 30). Instead of single-channel NIRS, steady-state diffuse reflectance spectroscopy (SSDRS...combination of normobaric and hyperbaric oxygen interventions) simultaneously monitored by steady-state diffuse reflectance spectroscopy (SSDRS) and...simultaneously by steady-state diffuse reflectance spectroscopy (SSDRS) and FOXY oxygen sensor in response to normobaric and hyperbaric oxygen

  11. Interaction Study of an Amorphous Solid Dispersion of Cyclosporin A in Poly-Alpha-Cyclodextrin with Model Membranes by (1)H-, (2)H-, (31)P-NMR and Electron Spin Resonance.

    PubMed

    Debouzy, Jean-Claude; Crouzier, David; Bourbon, Fréderic; Lahiani-Skiba, Malika; Skiba, Mohamed

    2014-01-01

    The properties of an amorphous solid dispersion of cyclosporine A (ASD) prepared with the copolymer alpha cyclodextrin (POLYA) and cyclosporine A (CYSP) were investigated by (1)H-NMR in solution and its membrane interactions were studied by (1)H-NMR in small unilamellar vesicles and by (31)P (2)H NMR in phospholipidic dispersions of DMPC (dimyristoylphosphatidylcholine) in comparison with those of POLYA and CYSP alone. (1)H-NMR chemical shift variations showed that CYSP really interacts with POLYA, with possible adduct formation, dispersion in the solid matrix of the POLYA, and also complex formation. A coarse approach to the latter mechanism was tested using the continuous variations method, indicating an apparent 1 : 1 stoichiometry. Calculations gave an apparent association constant of log Ka = 4.5. A study of the interactions with phospholipidic dispersions of DMPC showed that only limited interactions occurred at the polar head group level ((31)P). Conversely, by comparison with the expected chain rigidification induced by CYSP, POLYA induced an increase in the fluidity of the layer while ASD formation led to these effects almost being overcome at 298 K. At higher temperature, while the effect of CYSP seems to vanish, a resulting global increase in chain fluidity was found in the presence of ASD.

  12. The mitochondrial precursor protein apocytochrome c strongly influences the order of the headgroup and acyl chains of phosphatidylserine dispersions. A sup 2 H and sup 31 P NMR study

    SciTech Connect

    Jordi, W.; de Kroon, A.I.P.M.; Killian, A.; de Kruijff, B. )

    1990-03-06

    Deuterium and phosphorus nuclear magnetic resonance techniques were used to study the interaction of the mitochondrial precursor protein apocytochrome c with headgroup-deuterated (dioleoylphosphatidyl-L-(2-{sup 2}H{sub 1})serine) and acyl chain deuterated (1,2-(11,11-{sup 2}H{sub 2})dioleoylphosphatidylserine) dispersions. Binding of the protein to dioleoylphosphatidylserine liposomes results in phosphorus nuclear magnetic resonance spectra typical of phospholipids undergoing fast axial rotation in extended liquid-crystalline bilayers with a reduced residual chemical shift anisotropy and an increased line width. {sup 2}H NMR spectra on headgroup-deuterated dioleoylphosphatidylserine dispersions showed a decrease in quadrupolar splitting and a broadening of the signal on interaction with apocytochrome c. Addition of increasing amounts of apocytochrome c to the acyl chain deuterated dioleoylphosphatidylserine dispersions results in the gradual appearance of a second component in the spectra with a 44% reduced quadrupolar splitting. Such large reduction of the quadrupolar splitting has never been observed for any protein studied yet. The induction of a new spectral component with a well-defined reduced quadrupolar splitting seems to be confined to the N-terminus since addition of a small hydrophilic amino-terminal peptide (residues 1-38) also induces a second component with a strongly reduced quadrupolar splitting. A chemically synthesized peptide corresponding to amino acid residues 2-17 of the presequence of the mitochondrial protein cytochrome oxidase subunit IV also has a large perturbing effect on the order of the acyl chains, indicating that the observed effects may be a property shared by many mitochondrial precursor proteins. Implications of these data for the import of apocytochrome c into mitochondria will be discussed.

  13. Magnetism of the spin-trimer compound CaNi 3(P 2O 7)2: Microscopic insight from combined 31P NMR and first-principles studies

    NASA Astrophysics Data System (ADS)

    Majumder, M.; Kanungo, S.; Ghoshray, A.; Ghosh, M.; Ghoshray, K.

    2015-03-01

    Magnetization, 31P nuclear magnetic resonance study, and first-principles electronic structure calculations have been performed in the spin-1 trimer chain compound CaNi3(P2O7 )2. Two separate spectra arising from magnetically and crystallographically inequivalent P sites are observed. In the ordered state, the resonance lines for both the P sites (P1 and P2) are found to be split into two, which is clear microscopic evidence of the development of two-sublattice AFM order below TM. A nonnegligible contribution of ferromagnetic hyperfine field and dipolar field have also been seen in the ordered state. The first-principles calculations show that the intratrimer (J1) and intertrimer interactions (J2) are of weak ferromagnetic type with the values 2.85 and 1.49 meV, respectively, whereas the interchain interaction (J3) is of strong antiferromagnetic type with a value of 5.63 meV. The anisotropy of the imaginary part of dynamical spin susceptibility around TM along with the exponential decrement of 1 /T1 below TM indicate the probable participation of the Ni -3 d electron's orbital degrees of freedom in the ferrimagnetic transition. The dominance of orbital fluctuations over the spin fluctuations seems to be responsible for showing low value of the binding energy u of the local spin configuration (estimated from local spin models) and an unusually weak exponent in the power-law behavior of 1 /T1 below 50 K, in the paramagnetic state. Electronic structure calculations also reveal the importance of orbital degrees of freedom of Ni -3 d moments, which is consistent with our NMR data analysis.

  14. Interplay between Fe 3d and Ce 4f magnetism and Kondo interaction in CeFeAs(1-x)P(x)O probed by 75As and 31P NMR.

    PubMed

    Sarkar, R; Baenitz, M; Jesche, A; Geibel, C; Steglich, F

    2012-04-04

    A detailed (31)P (I = 1/2) and (75)As (I = 3/2) NMR study on polycrystalline CeFeAs(1-x)P(x)O alloys is presented. The magnetism of CeFeAsO changes drastically upon P substitution on the As site. CeFePO is a heavy fermion system without long-range order whereas CeFeAsO exhibits an Fe 3d SDW type of ordering accompanied by a structural transition from tetragonal (TT) to orthorhombic (OT) structure. Furthermore, Ce 4f(1) orders antiferromagnetically (AFM) at low temperature. At the critical concentration where the Fe magnetism is diminished the Ce-Ce interaction changes to a ferromagnetic (FM) type of ordering. Three representative samples of the CeFeAs(1-x)P(x)O (x = 0.05, 0.3 and 0.9) series are systematically investigated. (1) For the x = 0.05 alloy a drastic change of the linewidth at 130 K indicates the AFM-SDW type of ordering of Fe and the structural change from the TT to the OT phase. The linewidth roughly measures the internal field in the ordered state and the transition is most likely first order. The small and nearly constant shift from (31)P and (75)As NMR suggests the presence of competing hyperfine interactions between the nuclear spins and the 4f and 3d ions of Ce and Fe. (2) For the x = 0.3 alloy, the evolution of the Fe-SDW type of order takes place at around 70 K corroborating the results of bulk measurement and μSR. Here we found evidence for phase separation of paramagnetic and magnetic SDW phases. (3) In contrast to the heavy fermion CeFePO for the x = 0.9 alloy a phase transition is found at 2 K. The field-dependent NMR shift gives evidence of FM ordering. Above the ordering the spin-lattice relaxation rate (31)(1/T(1)) shows unconventional, non-Korringa-like behaviour which indicates a complex interplay of Kondo and FM fluctuations.

  15. Photoacoustic spectroscopy sample array vessels and photoacoustic spectroscopy methods for using the same

    DOEpatents

    Amonette, James E.; Autrey, S. Thomas; Foster-Mills, Nancy S.

    2006-02-14

    Methods and apparatus for simultaneous or sequential, rapid analysis of multiple samples by photoacoustic spectroscopy are disclosed. Particularly, a photoacoustic spectroscopy sample array vessel including a vessel body having multiple sample cells connected thereto is disclosed. At least one acoustic detector is acoustically positioned near the sample cells. Methods for analyzing the multiple samples in the sample array vessels using photoacoustic spectroscopy are provided.

  16. Comparison of cerebral tissue oxygenation values in full term and preterm newborns by the simultaneous use of two near-infrared spectroscopy devices: an absolute and a relative trending oximeter

    NASA Astrophysics Data System (ADS)

    Szczapa, Tomasz; Karpiński, Łukasz; Moczko, Jerzy; Weindling, Michael; Kornacka, Alicja; Wróblewska, Katarzyna; Adamczak, Aleksandra; Jopek, Aleksandra; Chojnacka, Karolina; Gadzinowski, Janusz

    2013-08-01

    The aim of this study is to compare a two-wavelength light emitting diode-based tissue oximeter (INVOS), which is designed to show trends in tissue oxygenation, with a four-wavelength laser-based oximeter (FORE-SIGHT), designed to deliver absolute values of tissue oxygenation. Simultaneous values of cerebral tissue oxygenation (StO2) are measured using both devices in 15 term and 15 preterm clinically stable newborns on the first and third day of life. Values are recorded simultaneously in two periods between which oximeter sensor positions are switched to the contralateral side. Agreement between StO2 values before and after the change of sensor position is analyzed. We find that mean cerebral StO2 values are similar between devices for term and preterm babies, but INVOS shows StO2 values spread over a wider range, with wider standard deviations than shown by the FORE-SIGHT. There is relatively good agreement with a bias up to 3.5% and limits of agreement up to 11.8%. Measurements from each side of the forehead show better repeatability for the FORE-SIGHT monitor. We conclude that performance of the two devices is probably acceptable for clinical purposes. Both performed sufficiently well, but the use of FORE-SIGHT may be associated with tighter range and better repeatability of data.

  17. Quarkonium spectroscopy

    SciTech Connect

    Scharre, D.L.

    1981-06-01

    Recent experimental investigations of heavy quark-antiquark bound state systems are reviewed. Results from SPEAR on charmonium spectroscopy and from DORIS and CESR on bottomonium spectroscopy are presented. The current status of the search for top is also discussed.

  18. Measurements of the earth`s stratosphere using balloon-borne far infrared spectroscopy: Simultaneous measurements of HO{sub x}, NO{sub x}, and Cl{sub x}

    SciTech Connect

    Chance, K.

    1995-12-31

    The Smithsonian Astrophysical Observatory far-infrared spectrometer (FIRS-2) measures vertical mixing ratio profiles in the stratosphere from a balloon platform. The FIRS-2 is a high-resolution (0.004 cm{sup -1} unapodized) two-beam Fourier transform spectrometer which measures thermal emission in the regions 80-210 cm{sup -1} and 350-700 cm{sup -1}. Observations are made at various elevation angles, with absolute pointing referenced to a gyroscope- and accelerometer-stabilized single-axis platform. Molecules currently measured include OH, HO{sub 2}, H{sub 2}O, H{sub 2}O{sub 2}, O{sub 3}P, O{sub 2}, O{sub 3}, HCl, HF, HBr, HOCl, HOBr, CO, CO{sub 2}, N{sub 2}O, NO{sub 2}, HNO{sub 3}, and HCN. The measurements, the development of the relevant spectroscopy, and the application of the measurements to improving models of the photochemistry of the ozone layer are discussed.

  19. Nano-scale simultaneous observation of Li-concentration profile and Ti-, O electronic structure changes in an all-solid-state Li-ion battery by spatially-resolved electron energy-loss spectroscopy

    NASA Astrophysics Data System (ADS)

    Yamamoto, Kazuo; Yoshida, Ryuji; Sato, Takeshi; Matsumoto, Hiroaki; Kurobe, Hisanori; Hamanaka, Tadashi; Kato, Takehisa; Iriyama, Yasutoshi; Hirayama, Tsukasa

    2014-11-01

    All-solid-state Li-ion batteries having incombustible solid electrolytes are expected to be promising candidates for safe next-generation energy storage devices that have a long lifetime and high energy density. However, it is essential to address the large resistance of Li-ion transfer at the electrode/solid-electrolyte interfaces. A new concept electrode that is formed in situ from the Li2O-Al2O3-TiO2-P2O5-based glass-ceramic solid electrolytes with Si and Ge doping (LASGTP) produces atomic scale connection at the interfaces, which provides extremely low interfacial resistance. However, the formation mechanism and the reason for the low resistance are still unclear. Here we applied spatially-resolved electron energy-loss spectroscopy in a transmission electron microscope mode (SR-TEM-EELS) to visualize the nanometer-scale Li distribution and its effects on the electronic structures of other important elements (Ti and O). Local electron diffraction showed that the in situ formed electrode was an amorphous phase caused by the Li insertion. Picometer-scale expansion of O-O distance due to the Li insertion was also visualized in the electrode. These electronic and crystal changes and gradual Li distribution contribute to the low resistance and stable battery cycles.

  20. Investigation of a fiber optic surface plasmon spectroscopy in conjunction with conductivity as an in situ method for simultaneously monitoring changes in dissolved organic carbon and salinity in coastal waters.

    PubMed

    Kim, Yoon-Chang; Cramer, Jeffrey A; Booksh, Karl S

    2011-10-21

    A combination surface plasmon resonance (SPR) and conductivity sensor array was developed and implemented to demonstrate the ability to differentiate among changes in dissolved organic carbon (DOC) and salinity in coastal water. The array is capable of achieving sufficient spatial and temporal data density to better understand the cycling and fate of terrestrial DOC in coastal areas. DOC is the second largest source of bioreactive carbon in the environment and plays a key role in mediating microbial activity and generation of atmospheric CO(2). In the coastal areas, the salinity is also an important property in many applications, such as leak detection for landfill liners, saltwater intrusion to drinking water, marine environment monitoring, and seasonal climate prediction. Conductivity sensors are the industry standard for determining salinity in ocean systems. However, both conductivity and refractive index sensors, such as SPR spectroscopy based sensors, respond to salinity and DOC levels. To demonstrate the capability of the SPR sensor and a conductivity sensor to collect complimentary data useful in discrimination of salinity and DOC in coastal zone water, conductivity, SPR, and temperature data were collected during passage from the Juan de Fuca ridge area returning to the University of Washington docks.

  1. Study by ³¹P NMR spectroscopy of the triacylglycerol degradation processes in olive oil with different heat-transfer mechanisms.

    PubMed

    Lucas-Torres, Covadonga; Pérez, Angel; Cabañas, Beatriz; Moreno, Andrés

    2014-12-15

    The thermal degradation of olive oil using conventional and microwave heating under the same experimental conditions were compared. A powerful identification and quantification technique based on (31)P NMR has been developed to characterise the differences between the minor components including diacylglycerol and free fatty acids in the heated samples. The (31)P NMR spectra of the degraded olive oils, which contain OH groups derivatised with a phosphorus reagent, showed that conventional heating is more detrimental to the oil than microwave technique. Conventional heating leads to a significant increase in the diacylglycerol and free fatty acid contents as well as in the number of degradation compounds, which damage the olive oil quality. However, the main process that takes place on using microwave heating is isomerisation between diacylglycerols, a change that could give a potential longer shelf life to the olive oil.

  2. Chiroptical spectroscopy

    NASA Astrophysics Data System (ADS)

    Gunde, Kevin Edward

    1997-09-01

    The research presented here is of chiroptical spectroscopy. A new type of non-linear chiroptical spectroscopy, two-photon circular dichroism, is developed experimentally and theoretically. A theoretical formalism is developed to describe another new chiroptical spectroscopy, second-harmonic generation circular dichroism. An established type of chiroptical spectroscopy, time-resolved chiroptical luminescence, is applied to two new sets of subject systems. Journal articles related to these topics, as well as other research to which the author has contributed, are reproduced and included as appendices.

  3. Simultaneity, relativity and conventionality

    NASA Astrophysics Data System (ADS)

    Janis, Allen I.

    2008-01-01

    The view of simultaneity presented by Max Jammer is almost breathtaking, encompassing, as the book's subtitle suggests, the period from antiquity to the 21st century. Many interesting things are to be found along the way. For example, what Jammer (p. 49) says "may well be regarded as probably the earliest recorded example of an operational definition of distant simultaneity" is due to St. Augustine (in his Confessions, written in 397 A.D.; for a modern translation, see Augustine, 2006). He was arguing against astrology by presenting the story of two women, one rich and one poor, who gave birth simultaneously. Although the two children thus had precisely the same horoscopes, their lives followed quite different courses. And how was it determined that the births were simultaneous? A messenger went from each birth site to the other, leaving the instant the child was born (and, presumably, traveling with equal speeds). Since the messengers met at the midpoint between the locations of the two births, the births must have been simultaneous. This is, of course, quite analogous to Albert Einstein's definition of simultaneity (given more than 1500 years later), which will be discussed in Section 2.1.

  4. Raman Spectroscopy.

    ERIC Educational Resources Information Center

    Gerrard, Donald L.

    1984-01-01

    Reviews literature on Raman spectroscopy from late 1981 to late 1983. Topic areas include: instrumentation and sampling; liquids and solutions; gases and matrix isolation; biological molecules; polymers; high-temperature and high-pressure studies; Raman microscopy; thin films and surfaces; resonance-enhanced and surface-enhanced spectroscopy; and…

  5. Amateur Spectroscopy

    NASA Astrophysics Data System (ADS)

    Gavin, M.; Murdin, P.

    2003-04-01

    Spectroscopy (see ASTRONOMICAL SPECTROSCOPY) has seen a revival of late. Pioneers in the 19th century such as Angelo Secchi and William Huggins observed spectra visually via large refractors under pristine skies. While the eye can comprehend the brilliant solar spectrum and a few brighter stars aided by a telescope, even low spectral dispersion greatly dilutes starlight. Photo-film can marginally ...

  6. Phosphorus-31 nuclear magnetic resonance studies of cellular systems

    SciTech Connect

    Robitaille, P.M.L.

    1986-01-01

    In this study, /sup 31/P-NMR spectroscopy was applied to the study of (1) sipunculan erythrocytes, (2) spermatozoa isolated from several vertebrate and invertebrate species, and (3) unfertilized eggs isolated from the blue crab and the horseshoe crab. /sup 31/P-NMR results center on the identification of key metabolites and on the determination of intracellular pH. In studies involving fish spermatozoa, emphasis was also placed on examining changes in metabolic profiles following (1) an anaerobic insult, (2) motility initiation, or (3) short-term storage. This study also captures several difficulties in spectral interpretation which a spectroscopist is likely to encounter.

  7. Psychosemantics and Simultaneous Interpretation.

    ERIC Educational Resources Information Center

    Le Ny, Jean-Francois

    A comprehension model of simultaneous interpretation activity raises three types of problems: structure of semantic information stored in long-term memory, modalities of input processing and specific restrictions due to situation. A useful concept of semantic mnesic structures includes: (1) a componential-predicative lexicon; (2) a propositional…

  8. Evaluating Simultaneous Integrals

    ERIC Educational Resources Information Center

    Kwong, Harris

    2012-01-01

    Many integrals require two successive applications of integration by parts. During the process, another integral of similar type is often invoked. We propose a method which can integrate these two integrals simultaneously. All we need is to solve a linear system of equations.

  9. Raman spectroscopy

    NASA Astrophysics Data System (ADS)

    Gleeson, Helen F.

    Raman spectroscopy has been used as a tool to study liquid crystals for several decades. There are several features that make Raman spectroscopy an important characterisation method. It is bond-specific, so can provide information about the interaction of liquid crystals with colloidal systems and can offer an insight into phase transitions. The polarization dependence of the scattering can be used to determine order parameters in liquid crystal systems. Finally, the relatively high spatial resolution of the technique (∽1 μm) can be used to explore spatiallydependent order in soft matter systems. This chapter describes the most important ways in which Raman spectroscopy can be used to reveal information about liquid crystal systems, illustrated by examples. Both the theoretical background and experimental considerations are described, providing a comprehensive introduction to anybody interested in using the technique to understand liquid crystal systems.

  10. Cometary spectroscopy

    NASA Astrophysics Data System (ADS)

    Biver, N.

    2011-04-01

    Cometary spectroscopy from the ultraviolet to the radio wavelength domain provides us with insights on the composition of the gases that are released by the cometary nuclei. While infrared to millimeter spectroscopy give access to the parent molecules that are released directly from the nucleus, visible spectroscopy enables observation of daughter species. Those "radicals" observable in the visible domain have more complex spectroscopic band-like structures and are mainly CN, C2, C3, NH2. Their spectroscopic signatures are easily accessible to amateur astronomers class equipment. Provided that carefully calibrated data are acquired, some simple calculation can readily be done to convert the line intensities into comet molecular outgassing rates and thus provide interesting physical data on comets. In addition to broadband dust measurements, the interested amateur can produce valuable scientific data on comets that will always be welcome from the professional community and certainly useful as the monitoring of comets activity is always essential.

  11. Simultaneous quantification of multiple magnetic nanoparticles

    NASA Astrophysics Data System (ADS)

    Rauwerdink, Adam M.; Giustini, Andrew J.; Weaver, John B.

    2010-11-01

    Distinct magnetic nanoparticle designs can have unique spectral responses to an AC magnetic field in a technique called the magnetic spectroscopy of Brownian motion (MSB). The spectra of the particles have been measured using desktop spectrometers and in vivo measurements. If multiple particle types are present in a region of interest, the unique spectral signatures allow for the simultaneous quantification of the various particles. We demonstrate such a potential experimentally with up to three particle types. This ability to concurrently detect multiple particles will enable new biomedical applications.

  12. SIMULTANEOUS DIFFERENTIAL EQUATION COMPUTER

    DOEpatents

    Collier, D.M.; Meeks, L.A.; Palmer, J.P.

    1960-05-10

    A description is given for an electronic simulator for a system of simultaneous differential equations, including nonlinear equations. As a specific example, a homogeneous nuclear reactor system including a reactor fluid, heat exchanger, and a steam boiler may be simulated, with the nonlinearity resulting from a consideration of temperature effects taken into account. The simulator includes three operational amplifiers, a multiplier, appropriate potential sources, and interconnecting R-C networks.

  13. Spectroscopy, scattering, and KK molecules

    SciTech Connect

    Weinstein, J.

    1994-04-01

    The author presents a pedagogical description of a new theoretical technique, based on the multichannel Schroedinger equation, for simultaneously applying the quark model to both meson spectroscopy and meson-meson scattering. This is an extension of an earlier analysis which led to the prediction that the f{sub o}(975) and a{sub o}(980) scalar mesons are K{bar K} molecular states.

  14. Modern Spectroscopy

    ERIC Educational Resources Information Center

    Barrow, Gordon M.

    1970-01-01

    Presents the basic ideas of modern spectroscopy. Both the angular momenta and wave-nature approaches to the determination of energy level patterns for atomic and molecular systems are discussed. The interpretation of spectra, based on atomic and molecular models, is considered. (LC)

  15. Simultaneous Determination of Cobalt, Copper, and Nickel by Multivariate Linear Regression.

    ERIC Educational Resources Information Center

    Dado, Greg; Rosenthal, Jeffrey

    1990-01-01

    Presented is an experiment where the concentrations of three metal ions in a solution are simultaneously determined by ultraviolet-vis spectroscopy. Availability of the computer program used for statistically analyzing data using a multivariate linear regression is listed. (KR)

  16. Note on Magnetism and Simultaneity

    ERIC Educational Resources Information Center

    Huggins, Elisha

    2009-01-01

    The paper on "Magnetism and Simultaneity" by Adler provides an excellent new thought experiment involving the lack of simultaneity in Einstein's special relativity. Adler uses the lack of simultaneity rather than the Lorentz contraction to derive the formula for the magnetic force on a moving charged particle. Advantages of his derivation are that…

  17. Grain Spectroscopy

    NASA Technical Reports Server (NTRS)

    Allamandola, L. J.

    1992-01-01

    Our fundamental knowledge of interstellar grain composition has grown substantially during the past two decades thanks to significant advances in two areas: astronomical infrared spectroscopy and laboratory astrophysics. The opening of the mid-infrared, the spectral range from 4000-400 cm(sup -1) (2.5-25 microns), to spectroscopic study has been critical to this progress because spectroscopy in this region reveals more about a materials molecular composition and structure than any other physical property. Infrared spectra which are diagnostic of interstellar grain composition fall into two categories: absorption spectra of the dense and diffuse interstellar media, and emission spectra from UV-Vis rich dusty regions. The former will be presented in some detail, with the latter only very briefly mentioned. This paper summarized what we have learned from these spectra and presents 'doorway' references into the literature. Detailed reviews of many aspects of interstellar dust are given.

  18. Laser Spectroscopy

    NASA Astrophysics Data System (ADS)

    Katori, H.; Yoneda, H.; Nakagawa, K.; Shimizu, F.

    2010-02-01

    Anderson localization of matter-waves in a controlled disorder: a quantum simulator? / A. Aspect ... [et al.] -- Squeezing and entanglement in a Bose-Einstein condensate / C. Gross ... [et al.] -- New physics in dipolar Bose-Einstein condensates / Y. Kawaguchi, H. Saito, and M. Ueda -- Observation of vacuum fluctuations in a spinor Bose-Einstein condensate / C. Klempt ... [et al.] -- Negative-index media for matter waves / F. Perales ... [et al.] -- Entanglement of two individual atoms using the Rydberg blockade / A. Browaeys ... [et al.] -- Array of mesoscopic ensembles on a magnetic atom chip / A. F. Tauschinsky ... [et al.] -- Stability of the proton-to-electron mass ratio tested with molecules using an optical link to primary clock / A. Amy-Klein ... [et al.] -- Metastable helium: lifetime measurements using cold atoms as a test of QED / K. G. H. Baldwin ... [et al.] -- Optical lattice clocks with single occupancy bosons and spin-polarized fermions toward 10[symbol] accuracy / M. Takamoto ... [et al.] -- Frequency measurements of Al[symbol] and Hg[symbol] optical standards / W. M. Itano ... [et al.] -- Switching of light with light using cold atoms inside a hollow optical fiber / M. Bajcsy ... [et al.] -- Room-temperature atomic ensembles for quantum memory and magnetometry / K. Jensen ... [et al.] -- Components for multi-photon non-classical state preparation and measurement / G. Puentes ... [et al.] -- Quantum field state measurement and reconstruction in a cavity by quantum nondemolition photon counting / M. Brune ... [et al.] -- XUV frequency comb spectroscopy / C. Gohle ... [et al.] -- Ultrahigh-repetition-rate pulse train with absolute-phase control produced by an adiabatic raman process / M. Katsuragawa ... [et al.] -- Strongly correlated bosons and fermions in optical lattices / S. Will ... [et al.] -- Bragg spectroscopy of ultracold bose gases in optical lattices / L. Fallani ... [et al.] -- Synthetic quantum many-body systems / C. Guerlin ... [et al

  19. Simultaneous Quantum Duel

    NASA Astrophysics Data System (ADS)

    Balthazar, Wagner F.; Huguenin, José A. O.; Schmidt, Alexandre G. M.

    2015-12-01

    We quantize the classical game of simultaneous two-person duel. In this game, the players Alice and Bob, have a two level system, for example, a spin 1/2 particle, which models alive and dead states. Through physical considerations we write up the unitary operator which represents the classical action of firing, which quantum mechanically is represented by flipping the opponent's spin and test its classical limits. We study three representative special cases of such duel where players start the duel: both alive; in a Bell state; and when one of them has her skills decreasing along the duel. We also present a proposal of experimental realization of this quantum game using twin photons produced by spontaneous parametric down conversion.

  20. Raman spectroscopy

    SciTech Connect

    Gerrard, D.L.; Bowley, H.J.

    1988-06-15

    The period of this review is from late 1985 to late 1987. During this time over 6000 papers have been published in the scientific literature dealing with many applications of Raman spectroscopy and extending its use to new areas of study. This article covers only those papers that are relevant to the analytical chemist and this necessitates a highly selective approach. There are some areas that have been the subject of many papers with relatively few being of analytical interest. In such cases the reader is referred to appropriate reviews which are detailed in this section.

  1. Laser Spectroscopy

    NASA Astrophysics Data System (ADS)

    Hollberg, Leo; Bergquist, James Charles; Kasevich, Mark A.

    2008-04-01

    Degenerate gases. Probing vortex pair sizes in the Berezinskii-Kosterlitz-Thouless regime on a two-dimensional lattice of Bose-Einstein condensates / V. Schweikhard ... [et al.]. Interacting Bose-Einstein condensates in random potentials / P. Bouyer ... [et al.]. Towards quantum magnetism with ultracold atoms in optical lattices / I. Bloch -- Precision measurement and fundamental physics. T-violation and the search for a permanent electric dipole moment of the mercury atom / E. N. Fortson -- Quantum information and control I. Quantum information processing and ramsey spectroscopy with trapped ions / C. F. Roos ... [et al.]. Quantum non-demolition counting of photons in a cavity / S. Haroche ... [et al.] -- Ultra-fast control and spectroscopy. Frequency-Comb- assisted mid-infrared spectroscopy / P. de Natale ... [et al.] -- Precision measurement and applications. Precision gravity tests by atom interferometry / G. M. Tino ... [et al.] -- Novel spectroscopic applications. On a variation of the proton-electron mass ratio / W. Ubachs ... [et al.] -- Quantum information and control II. Quantum interface between light and atomic ensembles / H. Krauter ... [et al.] -- Degenerate Fermi gases. An atomic Fermi gas near a P-wave Feshbach resonance / D. S. Jin, J. P. Gaebler and J. T. Stewart. Bragg scattering of correlated atoms from a degenerate Fermi gas / R. J. Ballagh, K. J. Challis and C. W. Gardiner -- Spectroscopy and control of atoms and molecules. Stark and Zeeman deceleration of neutral atoms and molecules / S. D. Hogan ... [et al.]. Generation of coherent, broadband and tunable soft x-ray continuum at the leading edge of the driver laser pulse / A. Jullien ... [et al.]. Controlling neural atoms and photons with optical conveyor belts and ultrathin optical fibers / D. Meschede. W. Alt and A. Rauschenbeutel -- Spectroscopy on the small scale. Wide-field cars-microscopy / C. Heinrich ... [et al.]. Atom nano-optics and nano-lithography / V. I. Balykin ... [et al

  2. Simultaneity in Emotional Moments

    NASA Astrophysics Data System (ADS)

    Clore, Gerald L.

    Emotions are described as emergent states, which exist only to the extent that multiple affective reactions to the same object occur at the same time. Emotions are thus the confluence of thoughts, feelings, expressions, desires, and so on. They emerge as meta-cognitive representations of embodied affective reactions. Emotions may be initiated by low-level, automatic, unconscious affective reactions, which are then iteratively re-processed with ever greater cognitive involvement until they become elaborated into emotional states. Affective and emotional reactions act as information about the value of objects of judgment and of accessible cognitions and inclinations during tasks. They influence judgment and thought when they are experienced simultaneously with sensory data about the world. Affective influences thus depend on our inability to disentangle affective from descriptive perceptions. To the extent that affective reactions reflect different, incommensurate sources of value (e.g., utilitarian, moral, aesthetic), perceived persons or objects may be experienced as being transcendently good or evil. Experiments varying people's attributions for their affective experiences allow the separate roles of affective and descriptive information to be examined. However, it is the inability to parse everyday experience into its separate sources of evaluative and descriptive information that gives rise to a colourful and transcendent reality.

  3. Simultaneous blur contrast

    NASA Astrophysics Data System (ADS)

    Webster, Shernaaz M.; Webster, Michael A.; Taylor, John; Jaikumar, Jaikishan; Verma, Richa

    2001-06-01

    How well-focused an image appears can be strongly influenced by the surroundings context. A blurred surround can cause a central image to appear too sharp, while sharped surrounds can induce blur. We examined some spatial properties and stimulus selectivities of this 'simultaneous blur contrast.' Observers adjusted the focus of a central test image by a 2AFC staircase procedure that varied the slope of the image amplitude spectrum. The test were surrounded by 8 identical images with biased spectra, that were presented concurrently with the test for 0.5 sec on a uniform gray background. Contrast effects were comparable in magnitude for image sizes ranging from 1-deg to 4-deg in visual angle, but were stronger for test that were viwe4 in the periphery rather than fixated directly. Consistent biases were found for different types of grayscale images, including natural images, filtered noise, and simple edges. However, effects were weaker when surrounds and tests were drawn from different images, or differed in contrast-polarity or color, and thus do not depend on blur or on average spatial- frequency content per se. These induction effects may in part reflect a manifestation of selective contrast gain control

  4. A Demonstration of Simultaneous Electrochemiluminescence

    ERIC Educational Resources Information Center

    Ibanez, Jorge G.; Zavala-Araiza, Daniel; Sotomayor-Martinez Barranco, Biaani; Torres-Perez, Jonatan; Camacho-Zuniga, Claudia; Bohrmann-Linde, Claudia; Tausch, Michael W.

    2013-01-01

    Paired (simultaneous) electrochemical processes can increase energy savings in selected cases by using the reactions at both electrodes of an electrochemical cell to perform a desired process, as is the case in the commercially successful chlor-alkali process. In the demonstration described herein, simultaneous blue electrochemiluminescence (ECL)…

  5. Simultaneous Spectral Temporal Adaptive Raman Spectrometer - SSTARS

    NASA Technical Reports Server (NTRS)

    Blacksberg, Jordana

    2010-01-01

    Raman spectroscopy is a prime candidate for the next generation of planetary instruments, as it addresses the primary goal of mineralogical analysis, which is structure and composition. However, large fluorescence return from many mineral samples under visible light excitation can render Raman spectra unattainable. Using the described approach, Raman and fluorescence, which occur on different time scales, can be simultaneously obtained from mineral samples using a compact instrument in a planetary environment. This new approach is taken based on the use of time-resolved spectroscopy for removing the fluorescence background from Raman spectra in the laboratory. In the SSTARS instrument, a visible excitation source (a green, pulsed laser) is used to generate Raman and fluorescence signals in a mineral sample. A spectral notch filter eliminates the directly reflected beam. A grating then disperses the signal spectrally, and a streak camera provides temporal resolution. The output of the streak camera is imaged on the CCD (charge-coupled device), and the data are read out electronically. By adjusting the sweep speed of the streak camera, anywhere from picoseconds to milliseconds, it is possible to resolve Raman spectra from numerous fluorescence spectra in the same sample. The key features of SSTARS include a compact streak tube capable of picosecond time resolution for collection of simultaneous spectral and temporal information, adaptive streak tube electronics that can rapidly change from one sweep rate to another over ranges of picoseconds to milliseconds, enabling collection of both Raman and fluorescence signatures versus time and wavelength, and Synchroscan integration that allows for a compact, low-power laser without compromising ultimate sensitivity.

  6. Exoplanet transmission spectroscopy using KMOS

    NASA Astrophysics Data System (ADS)

    Parviainen, Hannu; Aigrain, Suzanne; Thatte, Niranjan; Barstow, Joanna K.; Evans, Thomas M.; Gibson, Neale

    2015-11-01

    KMOS (K-Band Multi Object Spectrograph) is a novel integral field spectrograph installed in the Very Large Telescope's (VLT's) ANTU unit. The instrument offers an ability to observe 24 2.8 arcsec × 2.8 arcsec subfields positionable within a 7.2 arcmin patrol field, each subfield producing a spectrum with a 14 × 14-pixel spatial resolution. The main science drivers for KMOS are the study of galaxies, star formation, and molecular clouds, but its ability to simultaneously measure spectra of multiple stars makes KMOS an interesting instrument for exoplanet atmosphere characterization via transmission spectroscopy. We set to test whether transmission spectroscopy is practical with KMOS, and what are the conditions required to achieve the photometric precision needed, based on observations of a partial transit of WASP-19b, and full transits of GJ 1214b and HD 209458b. Our analysis uses the simultaneously observed comparison stars to reduce the effects from instrumental and atmospheric sources, and Gaussian processes to model the residual systematics. We show that KMOS can, in theory, deliver the photometric precision required for transmission spectroscopy. However, this is shown to require (a) pre-imaging to ensure accurate centring and (b) a very stable night with optimal observing conditions (seeing ˜0.8 arcsec). Combining these two factors with the need to observe several transits, each with a sufficient out-of-transit baseline (and with the fact that similar or better precision can be reached with telescopes and instruments with smaller pressure), we conclude that transmission spectroscopy is not the optimal science case to take advantage of the abilities offered by KMOS and VLT.

  7. Amateur spectroscopy

    NASA Astrophysics Data System (ADS)

    Gavin, M. V.

    1998-06-01

    (The 1997 Presidential Address to the British Astronomical Association.) Auguste Comte is remembered for an unfortunate remark. In 1825 he said the chemical composition of stars would never be revealed. Within a decade or so the heart of the atom was being explored in remote stars through the science of spectroscopy. In simplistic terms one can regard the atom as a miniature solar system, but with the novel option that electrons (representing planets) having the ability to 'jump' from one orbit to another. In 'falling' to a lower orbit a photon of light of precise wavelength is released to travel outwards. When the electron 'jumps' to a higher orbit a photon of light is absorbed. This is taking place on a vast scale which we observe as lines in the spectrum - their position and prominence relates to the particular atomic element, temperature and pressure within the stellar atmosphere. It is beyond the scope of this Address to discuss the various processes that affect spectra, or to provide a mathematical explanation which can be found elsewhere. In any case the lack of a deep understanding does not preclude enjoyable or useful observations. Methods and results from amateurs conducting such observations are discussed in this paper.

  8. MHD Spectroscopy

    SciTech Connect

    Heeter, R F; Fasoli, A; Testa, D; Sharapov, S; Berk, H L; Breizman, B; Gondhalekar, A; Mantsinen, M

    2004-03-23

    Experiments are conducted on the JET tokamak to assess the diagnostic potential of MHD active and passive spectroscopy, for the plasma bulk and its suprathermal components, using Alfv{acute e}n Eigenmodes (AEs) excited by external antennas and by energetic particles. The measurements of AE frequencies and mode numbers give information on the bulk plasma. Improved equilibrium reconstruction, in particular in terms of radial profiles of density and safety factor, is possible from the comparison between the antenna driven spectrum and that calculated theoretically. Details of the time evolution of the non-monotonic safety factor profile in advanced scenarios can be reconstructed from the frequency of ICRH-driven energetic particle modes. The plasma effective mass can be inferred from the resonant frequency of externally driven AEs in discharges with similar equilibrium profiles. The stability thresholds and the nonlinear development of the instabilities can give clues on energy and spatial distribution of the fast particle population. The presence of unstable AEs provides lower limits in the energy of ICRH generated fast ion tails. Fast ion pressure gradients and their evolution can be inferred from the stability of AEs at different plasma radial positions. Finally, the details of the AE spectrum in the nonlinear stage can be used to obtain information about the fast particle velocity space diffusion.

  9. SIMP spectroscopy

    NASA Astrophysics Data System (ADS)

    Hochberg, Yonit; Kuflik, Eric; Murayama, Hitoshi

    2016-05-01

    We study the interactions between strongly interacting massive particle dark matter and the Standard Model via a massive vector boson that is kinetically mixed with the hypercharge gauge boson. The relic abundance is set by 3 → 2 self-interactions of the dark matter, while the interactions with the vector mediator enable kinetic equilibrium between the dark and visible sectors. We show that a wide range of parameters is phenomenologically viable and can be probed in various ways. Astrophysical and cosmological constraints are evaded due to the p-wave nature of dark matter annihilation into visible particles, while direct detection methods using electron recoils can be sensitive to parts of the parameter space. In addition, we propose performing spectroscopy of the strongly coupled dark sector at e + e - colliders, where the energy of a mono-photon can track the resonance structure of the dark sector. Alternatively, some resonances may decay back into Standard Model leptons or jets, realizing `hidden valley' phenomenology at the LHC and ILC in a concrete fashion.

  10. Simultaneous monitoring of multimetallic atom densities in plasma processes employing a multimicrohollow cathode lamp

    SciTech Connect

    Ohta, Takayuki; Ito, Masafumi; Tachibana, Yoshihiro; Taneda, Satoshi; Takashima, Seigo; Hori, Masaru; Kano, Hiroyuki; Den, Shoji

    2007-06-18

    The authors have developed a simultaneous measurement technique of multimetallic atom densities in process plasmas using absorption spectroscopy employing a multimicrohollow cathode plasma as a light source. The optical emissions of four metallic atoms of Cu, Zn, Fe, and Mo were simultaneously produced from the multimicrohollow cathode plasma of millimeter size. The absolute densities of Cu and Mo in the magnetron sputtering plasma were simultaneously measured using this technique. The simultaneous monitoring of multimetallic atoms is very useful for controlling the plasma processes precisely.

  11. Infrared spectroscopy of aerosols

    NASA Astrophysics Data System (ADS)

    Mentel, Th.; Sebald, H.

    2003-04-01

    In our large Aerosol Chamber at the FZ Jülich we apply HR FTIR absorption spectroscopy for the determination of trace gases. In the FTIR spectra we also observe broad absorptions of several 10 to a few 100 cm-1 widths that arise from species in the condensed aerosol phase: liquid H_2O, NO_3^-, SO_42-, HSO_4^-, or dicarboxylic acids. Moreover, the aerosol droplets caused extinctions over several 1000 cm-1 by IR scattering. This allows for in-situ observation of changes in the condensed aerosol phase e.g. on HNO_3 uptake, like the shift of the sulfate/bisulfate equilibrium or the growth by water condensation. The IR absorptions of the condensed aerosol phase provide useful extra information in process studies, if they can be quantified. Therefore the absorption cross section, respective, the absorption index which is the imaginary part of the complex refractive index is needed. We set up an aerosol flow tube in which IR spectroscopy on a 8 m light path and aerosol size distribution measurements in the range from 20 nm - 10 μm can be performed simultaneously. We measured sulfate aerosols at several relative humidities (dry, metastable, deliquescent). We will demonstrate an iterative procedure based on Mie calculations and Kramers Kronig transformation to retrieve the absorption index from the observed IR spectra and the corresponding size distribution (for dry ammonium sulfate). We will compare resulting absorption indices for aqueous sodium bisulfate aerosols at several relative humidties with thermodynamic model calculations for the Na^+/H^+/HSO_4^-/SO_42-/H_2O system.

  12. [Simultaneous radical retropubic prostatectomy, diverticulectomy].

    PubMed

    Loran, O B; Sokolov, A E; Guspanov, R I; Polegen'kiĭ, V V

    2014-01-01

    Presented clinical case demonstrates a combination of rare congenital abnormality - giant true diverticula of the bladder - and high-risk prostate cancer, as well as a successful result of simultaneous operation - a radical prostatectomy with diverticulectomy.

  13. Audio-visual simultaneity judgments.

    PubMed

    Zampini, Massimiliano; Guest, Steve; Shore, David I; Spence, Charles

    2005-04-01

    The relative spatiotemporal correspondence between sensory events affects multisensory integration across a variety of species; integration is maximal when stimuli in different sensory modalities are presented from approximately the same position at about the same time. In the present study, we investigated the influence of spatial and temporal factors on audio-visual simultaneity perception in humans. Participants made unspeeded simultaneous versus successive discrimination responses to pairs of auditory and visual stimuli presented at varying stimulus onset asynchronies from either the same or different spatial positions using either the method of constant stimuli (Experiments 1 and 2) or psychophysical staircases (Experiment 3). The participants in all three experiments were more likely to report the stimuli as being simultaneous when they originated from the same spatial position than when they came from different positions, demonstrating that the apparent perception of multisensory simultaneity is dependent on the relative spatial position from which stimuli are presented.

  14. Chiroptical Spectroscopy

    NASA Astrophysics Data System (ADS)

    Gurst, Jerome E.

    1995-09-01

    A brief review of the literature, and Chemical and Engineering News in particular, reveals that the determination and use of optical activity is of increasing importance in today's commercial and research laboratories. The classical technique is to measure [alpha]D using a manual or recording polarimeter to provide a single value, the specific rotation at 589 nm. A spectropolarimeter can be used to determine optical activity through the UV-Visible spectrum (Optical Rotatory Dispersion [ORD]). At wavelengths far removed from electronic absorption bands, optical activity arises from circular birefringence, or the difference in the refractive index for left- and right-circularly polarized light; i.e., nL - nR does not equal zero for chiral materials. If the optical activity is measured through an absorption band, complex behavior is observed (a Cotton Effect curve). At an absorption band, chiral materials exhibit circular dichroism (CD), or a difference in the absorption of left- and right-circularly polarized light; epsilon L minus epsilon R does not equal zero. If the spectropolarimeter is set for the measurement of CD spectra, one observes what appears to be a UV-Vis spectrum except that some absorption bands are positive while others may be negative. Just as enantiomers have specific rotations that are equal and opposite at 589 nm (sodium D line), rotations are equal and opposite at all wavelengths, and CD measurements are equal and opposite at all wavelengths. Figure 1 shows the ORD curves for the enantiomeric carvones while Figure 2 contains the CD curves. The enantiomer of carvone that has the positive [alpha]D is obtained from caraway seeds and is known to have the S-configuration while the R-enantiomer is found in spearmint oil. Figure 1. ORD of S-(+)- and R-(-)-carvones Figure 2. CD of S-(+)- and R-(-)-carvones While little can be done to correlate stereochemistry with [alpha]D values, chiroptical spectroscopy (ORD and/or CD) often can be used to assign

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

    SciTech Connect

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

    1981-05-01

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

  16. Erythrocytes in muscular dystrophy. Investigation with /sup 31/P nuclear magnetic resonance spectroscopy

    SciTech Connect

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

    1981-05-01

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

  17. Spontaneous transient ultrafast coherent raman spectroscopy

    NASA Astrophysics Data System (ADS)

    Meiselman, Seth

    I explore the application of Transient Coherent Ultrafast Phonon Spectroscopy (TCUPS) to the measurement of vibrational coherence dynamics of liquid alcohols. The demonstrated technique is complementary to and, in some cases, simpler than traditional stimulated spectroscopy techniques in that it does not require more than one laser and is free of non-resonant background. I demonstrate coherence measurements of single-photon-level collective excitations: a single vibrational state at 1033 (1/cm) in; a pair of simultaneous excited vibrational states at 2834 and 2944 (1/cm) in methanol; and three simultaneous excited states at 2885, ˜2930, and 2976 (1/cm) in isopropanol. I develop a Fourier-transform-based analysis of the TCUPS data that overcomes poor signal-to-noise ratio and signal degradation due to etaloning and fluorescence. The coherence lifetimes and oscillation frequencies agree with frequency-domain line-shape measurements and femtosecond Coherent anti-Stokes Raman Scattering (CARS) measurements.

  18. Envisioning Curriculum as Six Simultaneities

    ERIC Educational Resources Information Center

    Hussain, Hanin; Conner, Lindsey; Mayo, Elaine

    2014-01-01

    This paper uses the discourse of complexity thinking to envision curriculum as six partial and coupled facets that exist simultaneously: curriculum as structure, curriculum as process, curriculum as content, curriculum as teaching, curriculum as learning and curriculum as activity. Such a curriculum is emergent and self-organising. It is emergent…

  19. Best Practices and Simultaneous Compliance

    EPA Science Inventory

    This wrap-up presentation to the workshop covers several topics concerning how lead and copper compliance under the Lead and Copper Rule should be integrated into an overall “simultaneous compliance” framework with other organizations. The LCR requires “optimization” of lead leve...

  20. Torque-mixing magnetic resonance spectroscopy.

    PubMed

    Losby, J E; Fani Sani, F; Grandmont, D T; Diao, Z; Belov, M; Burgess, J A J; Compton, S R; Hiebert, W K; Vick, D; Mohammad, K; Salimi, E; Bridges, G E; Thomson, D J; Freeman, M R

    2015-11-13

    A universal, torque-mixing method for magnetic resonance spectroscopy is presented. In analogy to resonance detection by magnetic induction, the transverse component of a precessing dipole moment can be measured in sensitive broadband spectroscopy, here using a resonant mechanical torque sensor. Unlike induction, the torque amplitude allows equilibrium magnetic properties to be monitored simultaneously with the spin dynamics. Comprehensive electron spin resonance spectra of a single-crystal, mesoscopic yttrium iron garnet disk at room temperature reveal assisted switching between magnetization states and mode-dependent spin resonance interactions with nanoscale surface imperfections. The rich detail allows analysis of even complex three-dimensional spin textures. The flexibility of microelectromechanical and optomechanical devices combined with broad generality and capabilities of torque-mixing magnetic resonance spectroscopy offers great opportunities for development of integrated devices.

  1. Heterodyne laser spectroscopy system

    DOEpatents

    Wyeth, Richard W.; Paisner, Jeffrey A.; Story, Thomas

    1989-01-01

    A heterodyne laser spectroscopy system utilizes laser heterodyne techniques for purposes of laser isotope separation spectroscopy, vapor diagnostics, processing of precise laser frequency offsets from a reference frequency and the like, and provides spectral analysis of a laser beam.

  2. Heterodyne laser spectroscopy system

    DOEpatents

    Wyeth, Richard W.; Paisner, Jeffrey A.; Story, Thomas

    1990-01-01

    A heterodyne laser spectroscopy system utilizes laser heterodyne techniques for purposes of laser isotope separation spectroscopy, vapor diagnostics, processing of precise laser frequency offsets from a reference frequency, and provides spectral analysis of a laser beam.

  3. Terahertz Spectroscopy of Biochars and Related Aromatic Compounds

    NASA Astrophysics Data System (ADS)

    Lepodise, L. M.; Horvat, J.; Lewis, R. A.

    2016-12-01

    A recent application of terahertz spectroscopy is to biochar, the agricultural charcoal produced by pyrolysis of various organic materials. Biochars simultaneously improve soil fertility and assist in carbon sequestration. Terahertz spectroscopy allows different biochars to be distinguished. However, the origin of the absorption features observed has not been clear. Given that biochar-based fertilizers are rich in aromatic compounds, we have investigated simple aromatic compounds as an approach to unravelling the complex biochar spectrum.

  4. Ultrafast slaving dynamics at the protein-water interface studied with 2D-IR spectroscopy

    NASA Astrophysics Data System (ADS)

    King, J. T.; Kubarych, K. J.

    2013-03-01

    The dynamics of hen egg white lysozyme in D2O/glycerol mixtures is studied using two-dimensional infrared spectroscopy. The hydration dynamics and the protein dynamics are studied simultaneously through vibrational probes attached to the protein surface.

  5. Simultaneous time and frequency resolved fluorescence microscopy of single molecules.

    SciTech Connect

    Hayden, Carl C.; Gradinaru, Claudiu C.; Chandler, David W.; Luong, A. Khai

    2005-01-01

    Single molecule fluorophores were studied for the first time with a new confocal fluorescence microscope that allows the wavelength and emission time to be simultaneously measured with single molecule sensitivity. In this apparatus, the photons collected from the sample are imaged through a dispersive optical system onto a time and position sensitive detector. This detector records the wavelength and emission time of each detected photon relative to an excitation laser pulse. A histogram of many events for any selected spatial region or time interval can generate a full fluorescence spectrum and correlated decay plot for the given selection. At the single molecule level, this approach makes entirely new types of temporal and spectral correlation spectroscopy of possible. This report presents the results of simultaneous time- and frequency-resolved fluorescence measurements of single rhodamine 6G (R6G), tetramethylrhodamine (TMR), and Cy3 embedded in thin films of polymethylmethacrylate (PMMA).

  6. SIMULTANEOUS MEASUREMENT OF CIRCULAR DICHROISM AND FLUORESCENCE POLARIZATION ANISOTROPY.

    SciTech Connect

    SUTHERLAND,J.C.

    2002-01-19

    Circular dichroism and fluorescence polarization anisotropy are important tools for characterizing biomolecular systems. Both are used extensively in kinetic experiments involving stopped- or continuous flow systems as well as titrations and steady-state spectroscopy. This paper presents the theory for determining circular dichroism and fluorescence polarization anisotropy simultaneously, thus insuring the two parameters are recorded under exactly the same conditions and at exactly the same time in kinetic experiments. The approach to measuring circular dichroism is that used in almost all conventional dichrographs. Two arrangements for measuring fluorescence polarization anisotropy are described. One uses a single fluorescence detector and signal processing with a lock-in amplifier that is similar to the measurement of circular dichroism. The second approach uses classic ''T'' format detection optics, and thus can be used with conventional photon-counting detection electronics. Simple extensions permit the simultaneous measurement of the absorption and excitation intensity corrected fluorescence intensity.

  7. Positional isotope exchange studies on enzyme using NMR spectroscopy

    SciTech Connect

    Matsunaga, T.O.

    1987-01-01

    The isotopically enriched compounds, /sup 18/O-..beta..,..gamma..-ATP and /sup 18/O bridge-labeled pyrophosphate, synthesized previously in this laboratory, were used to investigate and measure the exchange vs. turnover of substrates and products from their central complexes in four selected enzyme systems. Using hi-field /sup 31/P NMR, we were able to differentiate between /sup 18/O labeled in the bridge vs. the non-bridge positions by virtue of the isotope shift upon the phosphorus nuclei. The bridge to non-bridge scrambling of the label was quantitated and the exchange vs. turnover ratios under a variety of conditions was determined. Using the substrate inhibitor carboxycreatinine, PIX experiments with /sup 18/O-..beta..,..gamma..-ATP and creatine kinase were conducted. It was shown that carboxycreatinine and creatine kinase promoted exchange of the /sup 18/O label as determined by NMR. We have concluded that carboxycreatinine is either a substrate that catalyzes very slow turnover or it catalyzes exchange by a dissociative (SN/sub 1//sub P/) type of mechanism

  8. Microcoil nuclear magnetic resonance spectroscopy.

    PubMed

    Webb, A G

    2005-08-10

    In comparison with most analytical chemistry techniques, nuclear magnetic resonance has an intrinsically low sensitivity, and many potential applications are therefore precluded by the limited available quantity of certain types of sample. In recent years, there has been a trend, both commercial and academic, towards miniaturization of the receiver coil in order to increase the mass sensitivity of NMR measurements. These small coils have also proved very useful in coupling NMR detection with commonly used microseparation techniques. A further development enabled by small detectors is parallel data acquisition from many samples simultaneously, made possible by incorporating multiple receiver coils into a single NMR probehead. This review article summarizes recent developments and applications of "microcoil" NMR spectroscopy.

  9. Infrared spectroscopy of NGC 1068

    NASA Astrophysics Data System (ADS)

    Depoy, D. L.

    Spectroscopy of the nucleus of the nearby Seyfert 2 galaxy NGC 1068 has been obtained using the IRTF and the facility Cooled-Grating Array Spectrometer (CGAS). The wavelengths observed covered the expected wavelengths of the Bry (n = 7 4), Br (n = 5 4), and the Pf (n = 7 5) hydrogen recombination lines between 2.2 m and 4.6 m. The CGAS has a 32-element InSb array multiplexed by a Reticon and was used at a resolution of 250 km s-1, allowing accurate determination of the line profiles and surrounding continua simultaneously. For example, the S/N at each spectral position in the Br line spectrum was 100. The data show that the infrared lines are not more broadened than the optical hydrogen recombination lines, suggesting that the presence of an obscured Seyfert 1-like active nucleus is unlikely unless the visual extinction through any obscuring material present is larger than 100 mag.

  10. Multicomponent Analysis Using Synchronous-Excitation Phase-Resolved Fluorescence Spectroscopy.

    DTIC Science & Technology

    1987-12-04

    Excitation", APPLIED SPECTROSCOPY , 41, 395-399 (1987). Vitense, K. R. and McGown, L. B., "Simultaneous Two-Component Determination of Metals with 5-Sulfo-8...34, APPLIED SPECTROSCOPY , 41, 1080-1082 (1987). Vitense, K. R. and McGown, L. B., "Simultaneous Determination of A1(I1I) and Ga(III) with Lumogallion by Using

  11. Simultaneous bilateral patellar tendon rupture.

    PubMed

    Moura, Diogo Lino; Marques, José Pedro; Lucas, Francisco Manuel; Fonseca, Fernando Pereira

    2017-01-01

    Bilateral patellar tendon rupture is a rare entity, often associated with systemic diseases and patellar tendinopathy. The authors report a rare case of a 34-year-old man with simultaneous bilateral rupture of the patellar tendon caused by minor trauma. The patient is a retired basketball player with no past complaints of chronic knee pain and a history of steroid use. Surgical management consisted in primary end-to-end tendon repair protected temporarily with cerclage wiring, followed by a short immobilization period and intensive rehabilitation program. Five months after surgery, the patient was able to fully participate in sport activities.

  12. The diverse behaviour of the P-Cl bonds in the spiro-cis-ansa spermidine derivative cyclotriphosphazene towards mono-functional nucleophilic reagents

    NASA Astrophysics Data System (ADS)

    İbişoğlu, Hanife; Temur, Başak; Ün, İlker

    2009-10-01

    A number of new spiro-ansa spermidine derivative cyclotriphosphazenes ( 2- 10) is synthesized in order to provide insight into the reaction mechanism for nucleophilic substitution. The structures of the compounds were determined by elemental analysis, mass (MS), 1H, 19F (for 9) and 31P NMR spectroscopies. Compounds ( 2- 8) and 9, 10 can be formed by a proton abstraction-chloride elimination and both the SN1 and SN2 reaction mechanisms, respectively.

  13. Influence of natural organic matter on the bioavailability and preservation of organic phosphorus in lake sediments

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Organic P (Po) was sequentially extracted by H2O and NaOH-EDTA in the sediments from algae- and macrophyte-dominated regions of Lake Taihu, China and then analyzed by enzymatic hydrolysis and solution 31P-NMR spectroscopy. The amount of H2O-Po was 0.8-2.0 mg kg-1, 45.5% to 89.4% of which could be hy...

  14. Sub-Equimolar Hydrolysis and Condensation of Organophosphates

    DOE PAGES

    Alam, Todd M.; Kinnan, Mark K.; Wilson, Brendan W.; ...

    2016-07-16

    We characterized the in-situ hydrolysis and subsequent condensation reaction of the chemical agent simulant diethyl chlorophosphate (DECP) by high-resolution 31P NMR spectroscopy following the addition of water in sub-equimolar concentrations. Moreover, the identification and quantification of the multiple pyrophosphate and larger polyphosphate chemical species formed through a series of self-condensation reactions are reported. Finally, the DECP hydrolysis kinetics and distribution of breakdown species was strongly influenced by the water concentration and reaction temperature.

  15. Simultaneous tracking of spin angle and amplitude beyond classical limits

    NASA Astrophysics Data System (ADS)

    Colangelo, Giorgio; Ciurana, Ferran Martin; Bianchet, Lorena C.; Sewell, Robert J.; Mitchell, Morgan W.

    2017-03-01

    Measurement of spin precession is central to extreme sensing in physics, geophysics, chemistry, nanotechnology and neuroscience, and underlies magnetic resonance spectroscopy. Because there is no spin-angle operator, any measurement of spin precession is necessarily indirect, for example, it may be inferred from spin projectors at different times. Such projectors do not commute, and so quantum measurement back-action—the random change in a quantum state due to measurement—necessarily enters the spin measurement record, introducing errors and limiting sensitivity. Here we show that this disturbance in the spin projector can be reduced below N1/2—the classical limit for N spins—by directing the quantum measurement back-action almost entirely into an unmeasured spin component. This generates a planar squeezed state that, because spins obey non-Heisenberg uncertainty relations, enables simultaneous precise knowledge of spin angle and spin amplitude. We use high-dynamic-range optical quantum non-demolition measurements applied to a precessing magnetic spin ensemble to demonstrate spin tracking with steady-state angular sensitivity 2.9 decibels below the standard quantum limit, simultaneously with amplitude sensitivity 7.0 decibels below the Poissonian variance. The standard quantum limit and Poissonian variance indicate the best possible sensitivity with independent particles. Our method surpasses these limits in non-commuting observables, enabling orders-of-magnitude improvements in sensitivity for state-of-the-art sensing and spectroscopy.

  16. Simultaneous tracking of spin angle and amplitude beyond classical limits.

    PubMed

    Colangelo, Giorgio; Ciurana, Ferran Martin; Bianchet, Lorena C; Sewell, Robert J; Mitchell, Morgan W

    2017-03-22

    Measurement of spin precession is central to extreme sensing in physics, geophysics, chemistry, nanotechnology and neuroscience, and underlies magnetic resonance spectroscopy. Because there is no spin-angle operator, any measurement of spin precession is necessarily indirect, for example, it may be inferred from spin projectors at different times. Such projectors do not commute, and so quantum measurement back-action-the random change in a quantum state due to measurement-necessarily enters the spin measurement record, introducing errors and limiting sensitivity. Here we show that this disturbance in the spin projector can be reduced below N(1/2)-the classical limit for N spins-by directing the quantum measurement back-action almost entirely into an unmeasured spin component. This generates a planar squeezed state that, because spins obey non-Heisenberg uncertainty relations, enables simultaneous precise knowledge of spin angle and spin amplitude. We use high-dynamic-range optical quantum non-demolition measurements applied to a precessing magnetic spin ensemble to demonstrate spin tracking with steady-state angular sensitivity 2.9 decibels below the standard quantum limit, simultaneously with amplitude sensitivity 7.0 decibels below the Poissonian variance. The standard quantum limit and Poissonian variance indicate the best possible sensitivity with independent particles. Our method surpasses these limits in non-commuting observables, enabling orders-of-magnitude improvements in sensitivity for state-of-the-art sensing and spectroscopy.

  17. Simultaneous multislice (SMS) imaging techniques

    PubMed Central

    Barth, Markus; Breuer, Felix; Koopmans, Peter J.; Poser, Benedikt A.

    2015-01-01

    Simultaneous multislice imaging (SMS) using parallel image reconstruction has rapidly advanced to become a major imaging technique. The primary benefit is an acceleration in data acquisition that is equal to the number of simultaneously excited slices. Unlike in‐plane parallel imaging this can have only a marginal intrinsic signal‐to‐noise ratio penalty, and the full acceleration is attainable at fixed echo time, as is required for many echo planar imaging applications. Furthermore, for some implementations SMS techniques can reduce radiofrequency (RF) power deposition. In this review the current state of the art of SMS imaging is presented. In the Introduction, a historical overview is given of the history of SMS excitation in MRI. The following section on RF pulses gives both the theoretical background and practical application. The section on encoding and reconstruction shows how the collapsed multislice images can be disentangled by means of the transmitter pulse phase, gradient pulses, and most importantly using multichannel receiver coils. The relationship between classic parallel imaging techniques and SMS reconstruction methods is explored. The subsequent section describes the practical implementation, including the acquisition of reference data, and slice cross‐talk. Published applications of SMS imaging are then reviewed, and the article concludes with an outlook and perspective of SMS imaging. Magn Reson Med 75:63–81, 2016. © 2015 The Authors. Magnetic Resonance in Medicine Published by Wiley Periodicals, Inc. on behalf of International Society of Medicine in Resonance. PMID:26308571

  18. Simultaneous shoulder and elbow dislocation.

    PubMed

    Cobanoğlu, Mutlu; Yumrukcal, Feridun; Karataş, Cengiz; Duygun, Fatih

    2014-05-23

    Ipsilateral shoulder and elbow dislocation is very rare and only six articles are present in the literature mentioning this kind of a complex injury. With this presentation we aim to emphasise the importance of assessing the adjacent joints in patients with trauma in order not to miss any accompanying pathologies. We report a case of a 43-year-old female patient with ipsilateral right shoulder and elbow dislocation treated conservatively. The patient reported elbow pain when first admitted to emergency service but she was diagnosed with simultaneous ipsilateral shoulder and elbow injury and treated conservatively. As a more painful pathology may mask the additional ones, one should hasten to help before performing a complete evaluation. Any harm caused to the patient due to this reason would not be a complication but a malpractice.

  19. Simultaneous shoulder and elbow dislocation

    PubMed Central

    Çobanoğlu, Mutlu; Yumrukcal, Feridun; Karataş, Cengiz; Duygun, Fatih

    2014-01-01

    Ipsilateral shoulder and elbow dislocation is very rare and only six articles are present in the literature mentioning this kind of a complex injury. With this presentation we aim to emphasise the importance of assessing the adjacent joints in patients with trauma in order not to miss any accompanying pathologies. We report a case of a 43-year-old female patient with ipsilateral right shoulder and elbow dislocation treated conservatively. The patient reported elbow pain when first admitted to emergency service but she was diagnosed with simultaneous ipsilateral shoulder and elbow injury and treated conservatively. As a more painful pathology may mask the additional ones, one should hasten to help before performing a complete evaluation. Any harm caused to the patient due to this reason would not be a complication but a malpractice. PMID:24859563

  20. BATSE spectroscopy analysis system

    NASA Technical Reports Server (NTRS)

    Schaefer, Bradley E.; Bansal, Sandhia; Basu, Anju; Brisco, Phil; Cline, Thomas L.; Friend, Elliott; Laubenthal, Nancy; Panduranga, E. S.; Parkar, Nuru; Rust, Brad

    1992-01-01

    The Burst and Transient Source Experiment (BATSE) Spectroscopy Analysis System (BSAS) is the software system which is the primary tool for the analysis of spectral data from BATSE. As such, Guest Investigators and the community as a whole need to know its basic properties and characteristics. Described here are the characteristics of the BATSE spectroscopy detectors and the BSAS.

  1. VSWIR Microimaging Spectroscopy for Geologic History and Identifying and Quantifying Mineral, Ice, and Organic Abundances on Planetary Surfaces

    NASA Astrophysics Data System (ADS)

    Ehlmann, B. L.; Blaney, D. L.; Green, R. O.; Mouroulis, P.

    2016-10-01

    VSWIR microimaging spectroscopy is a key tool for landed planetary missions, acquiring simultaneous composition and texture. It has been matured to TRL 6 as UCIS and is presently being used for meteorite and terrestrial earth science studies.

  2. Laser Spectroscopy of Plasmas.

    DTIC Science & Technology

    1987-03-15

    AD-F161 00? LASER SPECTROSCOPY OF PLASMASMU CALIFORNIA NIY 1/1 BEKEEY J N DAILY 15 MAR 6? AFOSit-TR-6?-9?44 AFOSi-OS-0E? UNL SIFIF Z F//G2/9 M 22.5...TITLE (Inluded Secuity Clusifeation) 61102F 2308 I A3 Laser Spectroscopy of Plasmas ____________ % 12. PERSONAL AUTHOR(hI John W. Daily 13.. TYPE OF...Con Eanue on everse if neceuary and idenety by bioc* numInboen During the past year, work was initiated to develop novel advanced laser spectroscopy

  3. Simultaneous density contrast is bidirectional.

    PubMed

    Sun, Hua-Chun; Baker, Curtis L; Kingdom, Frederick A A

    2016-11-01

    Simultaneous density contrast, or SDC, is the phenomenon in which the perceived density of a textured region is altered by a surround of different density (Mackay, 1973). SDC provides an experimental tool to investigate mechanisms of density coding, yet has not been systematically examined. We measured SDC with a 2AFC staircase procedure in which human observers judged which of two patterns, one with and one without a surround, appeared more dense. We used a range of surround densities varying from very sparse to very dense (0-76.8 dots/deg2), and two center test densities (6.4 and 12.8 dots/deg2). Psychometric functions were used to estimate both the points of subjective equality (PSE) and their precision. Unexpectedly we find a bidirectional SDC effect across the five observers: Not only does a denser surround reduce perceived density of the center, but a sparser surround enhances its perceived density. We also show that SDC is not mediated by either contrast-contrast or spatial-frequency contrast. Our results suggest the presence of multiple channels selective for texture density, with lateral inhibitory interactions between them.

  4. LINPACK. Simultaneous Linear Algebraic Equations

    SciTech Connect

    Miller, M.A.

    1990-05-01

    LINPACK is a collection of FORTRAN subroutines which analyze and solve various classes of systems of simultaneous linear algebraic equations. The collection deals with general, banded, symmetric indefinite, symmetric positive definite, triangular, and tridiagonal square matrices, as well as with least squares problems and the QR and singular value decompositions of rectangular matrices. A subroutine-naming convention is employed in which each subroutine name consists of five letters which represent a coded specification (TXXYY) of the computation done by that subroutine. The first letter, T, indicates the matrix data type. Standard FORTRAN allows the use of three such types: S REAL, D DOUBLE PRECISION, and C COMPLEX. In addition, some FORTRAN systems allow a double-precision complex type: Z COMPLEX*16. The second and third letters of the subroutine name, XX, indicate the form of the matrix or its decomposition: GE General, GB General band, PO Positive definite, PP Positive definite packed, PB Positive definite band, SI Symmetric indefinite, SP Symmetric indefinite packed, HI Hermitian indefinite, HP Hermitian indefinite packed, TR Triangular, GT General tridiagonal, PT Positive definite tridiagonal, CH Cholesky decomposition, QR Orthogonal-triangular decomposition, SV Singular value decomposition. The final two letters, YY, indicate the computation done by the particular subroutine: FA Factor, CO Factor and estimate condition, SL Solve, DI Determinant and/or inverse and/or inertia, DC Decompose, UD Update, DD Downdate, EX Exchange. The LINPACK package also includes a set of routines to perform basic vector operations called the Basic Linear Algebra Subprograms (BLAS).

  5. LINPACK. Simultaneous Linear Algebraic Equations

    SciTech Connect

    Dongarra, J.J.

    1982-05-02

    LINPACK is a collection of FORTRAN subroutines which analyze and solve various classes of systems of simultaneous linear algebraic equations. The collection deals with general, banded, symmetric indefinite, symmetric positive definite, triangular, and tridiagonal square matrices, as well as with least squares problems and the QR and singular value decompositions of rectangular matrices. A subroutine-naming convention is employed in which each subroutine name consists of five letters which represent a coded specification (TXXYY) of the computation done by that subroutine. The first letter, T, indicates the matrix data type. Standard FORTRAN allows the use of three such types: S REAL, D DOUBLE PRECISION, and C COMPLEX. In addition, some FORTRAN systems allow a double-precision complex type: Z COMPLEX*16. The second and third letters of the subroutine name, XX, indicate the form of the matrix or its decomposition: GE General, GB General band, PO Positive definite, PP Positive definite packed, PB Positive definite band, SI Symmetric indefinite, SP Symmetric indefinite packed, HI Hermitian indefinite, HP Hermitian indefinite packed, TR Triangular, GT General tridiagonal, PT Positive definite tridiagonal, CH Cholesky decomposition, QR Orthogonal-triangular decomposition, SV Singular value decomposition. The final two letters, YY, indicate the computation done by the particular subroutine: FA Factor, CO Factor and estimate condition, SL Solve, DI Determinant and/or inverse and/or inertia, DC Decompose, UD Update, DD Downdate, EX Exchange. The LINPACK package also includes a set of routines to perform basic vector operations called the Basic Linear Algebra Subprograms (BLAS).

  6. Charmonium spectroscopy, 1987

    SciTech Connect

    Cahn, R.N.

    1987-07-30

    The state of charmonium spectroscopy is reviewed. All analyses proceed from a spin-dependent, non-relativistic Schroedinger equation. Many of the possible branching ratios for charm like states are investigated. 17 refs.

  7. Beam-foil spectroscopy

    SciTech Connect

    Berry, H.G.; Hass, M.

    1982-01-01

    A brief survey of some applications of beam-foil spectroscopy is presented. Among the topics covered are lifetime and magnetic moment measurements, nuclear alignment, and polarized light production. (AIP)

  8. Spectroscopy - so what?

    NASA Astrophysics Data System (ADS)

    Stanley, Matthew

    2010-07-01

    The development of astronomical spectroscopy allowed amazing achievements in investigating the composition and motion of celestial bodies. But even beyond specific measurements and results, the fruitfulness and practice of spectroscopy had important ramifications on a more abstract level. This paper will discuss ways in which spectroscopy inspired or boosted new theories of the atom, life, and the Universe; redrew the boundaries among scientific disciplines; demonstrated the unity of terrestrial and celestial physical laws; changed what counted as scientific knowledge; and even revealed divine mysteries. Scientists and science writers from the first half-century of astronomical spectroscopy will be discussed, including James Clerk Maxwell, William Crookes, John Tyndall, Agnes Clerke, William Huggins and Norman Lockyer.

  9. Spectroscopy - so what?

    NASA Astrophysics Data System (ADS)

    Stanley, Matthew

    2010-01-01

    The development of astronomical spectroscopy allowed amazing achievements in investigating the composition and motion of celestial bodies. But even beyond specific measurements and results, the fruitfulness and practice of spectroscopy had important ramifications on a more abstract level. This paper will discuss ways in which spectroscopy inspired or boosted new theories of the atom, life, and the universe; redrew the boundaries among scientific disciplines; demonstrated the unity of terrestrial and celestial physical laws; changed what counted as scientific knowledge; and even revealed divine mysteries. Scientists and science writers from the first half-century of astronomical spectroscopy will be discussed, including James Clerk Maxwell, William Thomson (Lord Kelvin), John Tyndall, Agnes Clerke, William Huggins, and Norman Lockyer.

  10. EDITORIAL: Nano Meets Spectroscopy Nano Meets Spectroscopy

    NASA Astrophysics Data System (ADS)

    Birch, David J. S.

    2012-08-01

    The multidisciplinary two-day Nano Meets Spectroscopy (NMS) event was held at the National Physical Laboratory (NPL), Teddington, UK, in September 2011. The event was planned from the outset to be at the interface of several areas—in particular, spectroscopy and nanoscience, and to bring together topics and people with different approaches to achieving common goals in biomolecular science. Hence the meeting cut across traditional boundaries and brought together researchers using diverse techniques, particularly fluorescence and Raman spectroscopy. Despite engaging common problems, these techniques are frequently seen as mutually exclusive with the two communities rarely interacting at conferences. The meeting was widely seen to have lived up to its billing in good measure. It attracted the maximum capacity of ~120 participants, including 22 distinguished speakers (9 from outside the UK), over 50 posters and a vibrant corporate exhibition comprising 10 leading instrument companies and IOP Publishing. The organizers were Professor David Birch (Chair), Dr Karen Faulds and Professor Duncan Graham of the University of Strathclyde, Professor Cait MacPhee of the University of Edinburgh and Dr Alex Knight of NPL. The event was sponsored by the European Science Foundation, the Institute of Physics, the Royal Society of Chemistry, NPL and the Scottish Universities Physics Alliance. The full programme and abstracts are available at http://sensor.phys.strath.ac.uk/nms/program.php. The programme was quite ambitious in terms of the breadth and depth of scope. The interdisciplinary and synergistic concept of 'X meets Y' played well, cross-fertilization between different fields often being a source of inspiration and progress. Fluorescence and Raman spectroscopy provided the core, but the meeting had little repetition and also attracted contributions on more specialist techniques such as CARS, super-resolution, single molecule and chiral methods. In terms of application the

  11. Nuclear Magnetic Resonance Spectroscopy

    DTIC Science & Technology

    1992-04-23

    and find new applications. A SENO 3 maturi ig undz:uanding of spin physics has allowed the de- 11 velopment of sophisticated techniques for assigning...structure of a fullerene Dist i S poial i9 derivative was determined. PAR" SENO3 I NMR spectroscopy continues to be invaluable as a routine 1i technique ...and SEN30 1s nucleic acids in solutions. The coverage of imaging and 7 spatially localized spectroscopy emphasizes technique de- 12 velopment and

  12. Spectroscopy of divertor plasmas

    SciTech Connect

    Isler, R.C.

    1995-12-31

    The requirements for divertor spectroscopy are treated with respect to instrumentation and observations on present machines. Emphasis is placed on quantitative measurements.of impurity concentrations from the interpretation of spectral line intensities. The possible influence of non-Maxwellian electron distributions on spectral line excitation in the divertor is discussed. Finally the use of spectroscopy for determining plasma temperature, density, and flows is examined.

  13. Spectroscopy of D Mesons

    SciTech Connect

    Bianco, Stefano

    2006-02-11

    The scenario of heavy quark meson spectroscopy underwent recently a major revolution, after the observation of BABAR and CLEO, confirmed by BELLE, of DsJ L=1 excited states, and by further evidences by SELEX. These experimental results have cast doubts on the incarnations of the ideas of Heavy Quark Effective Theory in heavy quark spectroscopy. I shall review the status of experimental data, discuss implications and sketch an outlook.

  14. [Thoracolaparoscopic simultaneous operations on esophagus].

    PubMed

    Khat'kov, I E; Izrailov, R E; Domrachev, S A; Kononets, P V; Vasnev, O S; Koshkin, M A

    2014-01-01

    Extirpation or subtotal resection of esophagus was performed in 14 patients by using of thoracolaparoscopic technique in terms from November 2011 to March 2014. The mean patients' age was 56 years old (27-67 years). In 10 patients indications for surgery included benign esophagus diseases such as cardiospasm stage IV (2 cases), peptic stricture (5 cases) and burn stricture (3 cases). 4 patients were operated for esophagus cancer including middle one-third cancer in 1 patient, lower one-third cancer in 3 cases. 10 patients underwent extirpation of esophagus with peristaltic gastric tube plasty. 1 patient had esophagus substituted by segment of the left colon. Esophageal anastomoses were formed on the neck (interrupted sutures were applied in 7 patients; staplers - in 3 cases). Lewis operation with intrapleural esophageal-gastric anastomosis forming was performed in 3 patients. The mean surgery duration was 579 minutes (305-710 min), mean blood loss - 141 ml (from 50 to 300 ml). Postoperative period had not complications in 8 of 14 patients. Different complications including partial failure of the anastomosis on the neck (5 cases), intrapleural anastomosis failure (1 case) were observed in 6 patients. Partial failure of the anastomosis on the neck was treated by using of therapy. All patients recovered. Patient with intrapleural anastomosis failure required additional surgery which included uncoupling of anastomosis, esophagostomy on the neck and gastrostomy forming. This patient died from recurrent myocardial infarction. Thus the authors consider that complete thoracolaparoscopic technique provides precise preparation of esophagus and stomach, adequate lymphadenectomy with minimal blood loss and operative trauma. The results after these operations are comparable with those after open interventions. Thoracolaparoscopic simultaneous operations must be applied in clinics having sufficient experience in esophagus surgery and thoracolaparoscopic technique.

  15. Electronic Spectroscopy & Dynamics

    SciTech Connect

    Mark Maroncelli, Nancy Ryan Gray

    2010-06-08

    The Gordon Research Conference (GRC) on Electronic Spectroscopy and Dynamics was held at Colby College, Waterville, NH from 07/19/2009 thru 07/24/2009. The Conference was well-attended with participants (attendees list attached). The attendees represented the spectrum of endeavor in this field coming from academia, industry, and government laboratories, both U.S. and foreign scientists, senior researchers, young investigators, and students. The GRC on Electronic Spectroscopy & Dynamics showcases some of the most recent experimental and theoretical developments in electronic spectroscopy that probes the structure and dynamics of isolated molecules, molecules embedded in clusters and condensed phases, and bulk materials. Electronic spectroscopy is an important tool in many fields of research, and this GRC brings together experts having diverse backgrounds in physics, chemistry, biophysics, and materials science, making the meeting an excellent opportunity for the interdisciplinary exchange of ideas and techniques. Topics covered in this GRC include high-resolution spectroscopy, biological molecules in the gas phase, electronic structure theory for excited states, multi-chromophore and single-molecule spectroscopies, and excited state dynamics in chemical and biological systems.

  16. 5 CFR 1651.11 - Simultaneous death.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 5 Administrative Personnel 3 2012-01-01 2012-01-01 false Simultaneous death. 1651.11 Section 1651.11 Administrative Personnel FEDERAL RETIREMENT THRIFT INVESTMENT BOARD DEATH BENEFITS § 1651.11 Simultaneous death. If a beneficiary dies at the same time as the participant, the beneficiary will be...

  17. 5 CFR 1651.11 - Simultaneous death.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 5 Administrative Personnel 3 2011-01-01 2011-01-01 false Simultaneous death. 1651.11 Section 1651.11 Administrative Personnel FEDERAL RETIREMENT THRIFT INVESTMENT BOARD DEATH BENEFITS § 1651.11 Simultaneous death. If a beneficiary dies at the same time as the participant, the beneficiary will be...

  18. 5 CFR 1651.11 - Simultaneous death.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 5 Administrative Personnel 3 2013-01-01 2013-01-01 false Simultaneous death. 1651.11 Section 1651.11 Administrative Personnel FEDERAL RETIREMENT THRIFT INVESTMENT BOARD DEATH BENEFITS § 1651.11 Simultaneous death. If a beneficiary dies at the same time as the participant, the beneficiary will be...

  19. 5 CFR 1651.11 - Simultaneous death.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 5 Administrative Personnel 3 2014-01-01 2014-01-01 false Simultaneous death. 1651.11 Section 1651.11 Administrative Personnel FEDERAL RETIREMENT THRIFT INVESTMENT BOARD DEATH BENEFITS § 1651.11 Simultaneous death. If a beneficiary dies at the same time as the participant, the beneficiary will be...

  20. 5 CFR 1651.11 - Simultaneous death.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 5 Administrative Personnel 3 2010-01-01 2010-01-01 false Simultaneous death. 1651.11 Section 1651.11 Administrative Personnel FEDERAL RETIREMENT THRIFT INVESTMENT BOARD DEATH BENEFITS § 1651.11 Simultaneous death. If a beneficiary dies at the same time as the participant, the beneficiary will be...

  1. Combined fiber probe for fluorescence lifetime and Raman spectroscopy

    PubMed Central

    Dochow, Sebastian; Ma, Dinglong; Latka, Ines; Bocklitz, Thomas; Hartl, Brad; Bec, Julien; Fatakdawala, Hussain; Marple, Eric; Urmey, Kirk; Wachsmann-Hogiu, Sebastian; Schmitt, Michael; Marcu, Laura; Popp, Jürgen

    2016-01-01

    In this contribution we present a dual modality fiber optic probe combining fluorescence lifetime imaging (FLIm) and Raman spectroscopy for in vivo endoscopic applications. The presented multi-spectroscopy probe enables efficient excitation and collection of fluorescence lifetime signals for FLIm in the UV/visible wavelength region, as well as of Raman spectra in the near-IR for simultaneous Raman/FLIm imaging. The probe was characterized in terms of its lateral resolution and distance dependency of the Raman and FLIm signals. In addition, the feasibility of the probe for in vivo FLIm and Raman spectral characterization of tissue was demonstrated. PMID:26093843

  2. Practical Considerations for Simultaneous LDV & PIV Measurements

    NASA Astrophysics Data System (ADS)

    Pothos, Stamatios; Boomsma, Aaron; Troolin, Dan

    2016-11-01

    Simultaneous LDV and PIV measurements are useful for validation experiments and when correlating high temporal resolution measurements with large structures of the flow. Performing simultaneous LDV and PIV measurements can be a challenging task due to the differences in temporal and spatial resolution of each technique, as well as requirements for adequate signal. Even so, simultaneous hot-wire and PIV measurements is even more difficult. Unlike hot-wire, LDV is a non-intrusive technique that is unaffected by PIV laser light-sheet heating. Furthermore, hot-wire measurements are adversely affected by seeding particles in the flow required for PIV. In the present study, we discuss several practical considerations for performing simultaneous LDV and PIV measurements. We completed two separate experiments, each with different seeding densities, flow velocities, and working fluids. With these data sets, we studied the effects of temporal and spatial interpolation, up/down sampling, PIV window size and overlap on the simultaneous signals.

  3. Optical control of fusion of microparticles in solution and simultaneous spectrophotometric measurements.

    PubMed

    Yao, H; Ikeda, H; Inoue, Y; Kitamura, N

    1996-12-01

    A multibeam laser manipulation technique has been applied to noncontact and nondestructive optical fusion of two dye-containing microdroplets or that of a dye/water droplet and a porous silica gel particle in solution. Characteristics of the dye/particle(s) before and after coalescence have been followed simultaneously by microspectroscopy. Application of the multibeam laser manipulation-spectroscopy method in microanalytical chemistry is discussed.

  4. Recent advances in the use of NIR spectroscopy for qualitative control and protection of extra virgin olive oil

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Recent studies on the use of near infrared (NIR) spectroscopy for the qualitative characterization of extra virgin olive oil, are reported and discussed in this paper. Research results confirms that NIR spectroscopy, combined with chemometric data analysis, allows to simultaneously evaluate all qual...

  5. The Use of Enzyme Hydrolysis to Assess the Seasonal Mobility and Bioavailability of Organic Phosphorus in Lake Sediments

    NASA Astrophysics Data System (ADS)

    Giles, C. D.; Lee, L. G.; Cade-Menun, B. J.; Rutila, B. C.; Schroth, A. W.; Xu, Y.; Hill, J. E.; Druschel, G.

    2013-12-01

    Lake sediments represent a significant internal source of phosphorus (P) in eutrophic freshwater systems during periods of high biological activity and oxygen depletion in sediments. Enzyme-labile and redox-sensitive P fractions may be a major component of the mobile sediment P pool which contributes to the development of harmful algal blooms. We present a high-through-put enzyme-based method for assessing potentially bioavailable (enzyme-labile) P in lake sediments and describe the relationship between enzyme-labile P, ascorbate-extractable (reactive) P and metals (Fe, Mn, Al, Ca), and P species identified using solution 31-P NMR spectroscopy. Sediment cores (0-10 cm) were collected from Lake Champlain over multiple years (Missisquoi Bay, VT, USA; 2007-2013). A principal components analysis of sediment properties suggests that enzyme-labile and reactive P, Mn, and Fe concentrations were more effective than the 31-P NMR methodology alone for differentiating algal bloom stage associated with periods of sediment anoxia. Bloom onset (July 2008) and peak bloom (August 2008, 2012) periods corresponded to the highest enzyme-labile P and lowest reactive P and metals proportions, despite 31-P NMR profiles which did not change significantly with respect to time and depth. High levels of reduced Fe and Mn ions were also detected in pore-water during this period, confirming previous reports that organic P bioavailability is linked to the redox status of sediments. High through-put analysis of enzyme-labile P fractions will provide spatially and temporally resolved information on bioavailable P pools at lower cost than traditional methods (i.e., 31-P NMR), and provide much-needed detail on aquatic P cycles during discrete stages of algal bloom development and sediment anoxia.

  6. Crystallinity and compositional changes in carbonated apatites: Evidence from {sup 31}P solid-state NMR, Raman, and AFM analysis

    SciTech Connect

    McElderry, John-David P.; Zhu, Peizhi; Mroue, Kamal H.; Xu, Jiadi; Pavan, Barbara; Fang, Ming; Zhao, Guisheng; McNerny, Erin; Kohn, David H.; Franceschi, Renny T.; Holl, Mark M.Banaszak; Tecklenburg, Mary M.J.; Ramamoorthy, Ayyalusamy; Morris, Michael D.

    2013-10-15

    Solid-state (magic-angle spinning) NMR spectroscopy is a useful tool for obtaining structural information on bone organic and mineral components and synthetic model minerals at the atomic-level. Raman and {sup 31}P NMR spectral parameters were investigated in a series of synthetic B-type carbonated apatites (CAps). Inverse {sup 31}P NMR linewidth and inverse Raman PO{sub 4}{sup 3−}ν{sub 1} bandwidth were both correlated with powder XRD c-axis crystallinity over the 0.3–10.3 wt% CO{sub 3}{sup 2−} range investigated. Comparison with bone powder crystallinities showed agreement with values predicted by NMR and Raman calibration curves. Carbonate content was divided into two domains by the {sup 31}P NMR chemical shift frequency and the Raman phosphate ν{sub 1} band position. These parameters remain stable except for an abrupt transition at 6.5 wt% carbonate, a composition which corresponds to an average of one carbonate per unit cell. This near-binary distribution of spectroscopic properties was also found in AFM-measured particle sizes and Ca/P molar ratios by elemental analysis. We propose that this transition differentiates between two charge-balancing ion-loss mechanisms as measured by Ca/P ratios. These results define a criterion for spectroscopic characterization of B-type carbonate substitution in apatitic minerals. - Graphical abstract: Carbonated apatite shows an abrupt change in spectral (NMR, Raman) and morphological (AFM) properties at a composition of about one carbonate substitution per unit cell. Display Omitted - Highlights: • Crystallinity (XRD), particle size (AFM) of carbonated apatites and bone mineral. • Linear relationships among crystallinity, {sup 31}P NMR and Raman inverse bandwidths. • Low and high carbonated apatites use different charge-balancing ion-loss mechanism.

  7. Phonons in Si24 at simultaneously elevated temperature and pressure

    NASA Astrophysics Data System (ADS)

    Tong, Xiao; Xu, Xiaolin; Fultz, B.; Zhang, Haidong; Strobel, Timothy A.; Kim, Duck Young

    2017-03-01

    Raman spectroscopy was used to measure the frequencies of phonons in Si24 with an open clathrate structure at temperatures from 80 to 400 K with simultaneous pressures of 0 to 8 GPa. The frequency shifts of the different phonons were substantially different under either temperature or pressure. The quasiharmonic behavior was isolated by varying pressure at low temperatures, and the anharmonic behavior was isolated by varying temperature at low pressures. Phonon modes dominated by bond bending were anomalous, showing stiffening with temperature and softening with pressure. Both the quasiharmonic behavior and the anharmonic behavior changed markedly with simultaneous changes in temperature Δ T and pressure Δ P . With Δ T =320 K and Δ P =8 GPa , some frequency shifts that scaled with the product Δ T Δ P were as large as the shifts from Δ T and Δ P alone. The thermodynamic entropy of this material likely has a dependence on Δ T and Δ P that cannot be obtained by adding effects from quasiharmonicity and phonon-phonon anharmonicity.

  8. Identification and characterization of a novel high affinity metal-binding site in the hammerhead ribozyme.

    PubMed Central

    Hansen, M R; Simorre, J P; Hanson, P; Mokler, V; Bellon, L; Beigelman, L; Pardi, A

    1999-01-01

    A novel metal-binding site has been identified in the hammerhead ribozyme by 31P NMR. The metal-binding site is associated with the A13 phosphate in the catalytic core of the hammerhead ribozyme and is distinct from any previously identified metal-binding sites. 31P NMR spectroscopy was used to measure the metal-binding affinity for this site and leads to an apparent dissociation constant of 250-570 microM at 25 degrees C for binding of a single Mg2+ ion. The NMR data also show evidence of a structural change at this site upon metal binding and these results are compared with previous data on metal-induced structural changes in the core of the hammerhead ribozyme. These NMR data were combined with the X-ray structure of the hammerhead ribozyme (Pley HW, Flaherty KM, McKay DB. 1994. Nature 372:68-74) to model RNA ligands involved in binding the metal at this A13 site. In this model, the A13 metal-binding site is structurally similar to the previously identified A(g) metal-binding site and illustrates the symmetrical nature of the tandem G x A base pairs in domain 2 of the hammerhead ribozyme. These results demonstrate that 31P NMR represents an important method for both identification and characterization of metal-binding sites in nucleic acids. PMID:10445883

  9. Crystallinity and compositional changes in carbonated apatites: Evidence from 31P solid-state NMR, Raman, and AFM analysis

    PubMed Central

    McElderry, John-David P.; Zhu, Peizhi; Mroue, Kamal H.; Xu, Jiadi; Pavan, Barbara; Fang, Ming; Zhao, Guisheng; McNerny, Erin; Kohn, David H.; Franceschi, Renny T.; Holl, Mark M. Banaszak; Tecklenburg, Mary M.J.; Ramamoorthy, Ayyalusamy; Morris, Michael D.

    2013-01-01

    Solid-state (magic-angle spinning) NMR spectroscopy is a useful tool for obtaining structural information on bone organic and mineral components and synthetic model minerals at the atomic-level. Raman and 31P NMR spectral parameters were investigated in a series of synthetic B-type carbonated apatites (CAps). Inverse 31P NMR linewidth and inverse Raman PO43− ν1 bandwidth were both correlated with powder XRD c-axis crystallinity over the 0.3–10.3 wt% CO32− range investigated. Comparison with bone powder crystallinities showed agreement with values predicted by NMR and Raman calibration curves. Carbonate content was divided into two domains by the 31P NMR chemical shift frequency and the Raman phosphate ν1 band position. These parameters remain stable except for an abrupt transition at 6.5 wt% carbonate, a composition which corresponds to an average of one carbonate per unit cell. This near-binary distribution of spectroscopic properties was also found in AFM-measured particle sizes and Ca/P molar ratios by elemental analysis. We propose that this transition differentiates between two charge-balancing ion-loss mechanisms as measured by Ca/P ratios. These results define a criterion for spectroscopic characterization of B-type carbonate substitution in apatitic minerals. PMID:24273344

  10. Crystallinity and compositional changes in carbonated apatites: Evidence from (31)P solid-state NMR, Raman, and AFM analysis.

    PubMed

    McElderry, John-David P; Zhu, Peizhi; Mroue, Kamal H; Xu, Jiadi; Pavan, Barbara; Fang, Ming; Zhao, Guisheng; McNerny, Erin; Kohn, David H; Franceschi, Renny T; Holl, Mark M Banaszak; Tecklenburg, Mary M J; Ramamoorthy, Ayyalusamy; Morris, Michael D

    2013-10-01

    Solid-state (magic-angle spinning) NMR spectroscopy is a useful tool for obtaining structural information on bone organic and mineral components and synthetic model minerals at the atomic-level. Raman and (31)P NMR spectral parameters were investigated in a series of synthetic B-type carbonated apatites (CAps). Inverse (31)P NMR linewidth and inverse Raman PO4(3-) ν1 bandwidth were both correlated with powder XRD c-axis crystallinity over the 0.3-10.3 wt% CO3(2-) range investigated. Comparison with bone powder crystallinities showed agreement with values predicted by NMR and Raman calibration curves. Carbonate content was divided into two domains by the (31)P NMR chemical shift frequency and the Raman phosphate ν1 band position. These parameters remain stable except for an abrupt transition at 6.5 wt% carbonate, a composition which corresponds to an average of one carbonate per unit cell. This near-binary distribution of spectroscopic properties was also found in AFM-measured particle sizes and Ca/P molar ratios by elemental analysis. We propose that this transition differentiates between two charge-balancing ion-loss mechanisms as measured by Ca/P ratios. These results define a criterion for spectroscopic characterization of B-type carbonate substitution in apatitic minerals.

  11. Contributions of nuclear magnetic resonance to renal biochemistry

    SciTech Connect

    Ross, B.; Freeman, D.; Chan, L.

    1986-01-01

    /sup 31/P NMR as a descriptive technique is of interest to nephrologists. Particular contributions of /sup 31/P NMR to our understanding of renal function may be enumerated.: Free metabolite levels are different from those classically accepted; in particular, ADP and Pi are low with implications for the control of renal metabolism and Pi transport, and, via the phosphorylation potential, for Na+ transport. Renal pH is heterogeneous; between cortex, outer medulla, and papilla, and between cell and lumen, a large pH gradient exists. Also, quantitation between cytosol and mitochondrion of the pH gradient is now feasible. In acute renal failure of either ischemic or nonischemic origin, both ATP depletion and acidification of the renal cell result in damage, with increasing evidence for the importance of the latter. Measurements of renal metabolic rate in vivo suggest the existence of a prodromal phase of acute renal failure, which could lead to its detection at an earlier and possibly reversible stage. Human renal cancers show a unique /sup 31/P NMR spectrum and a very acidic environment. Cancer chemotherapy may alter this and detection of such changes with NMR offers a method of therapeutic monitoring with significance beyond nephrology. Renal cortex and medulla have a different T1 relaxation time, possibly due to differences in lipid composition. It seems that NMR spectroscopy has much to offer to the future understanding of the relationship between renal biochemistry and function. 56 references.

  12. Fabricating Nanometer-Thick Simultaneously Oleophobic/Hydrophilic Polymer Coatings via a Photochemical Approach.

    PubMed

    Wang, Yongjin; Dugan, Michael; Urbaniak, Brian; Li, Lei

    2016-07-05

    The simultaneously oleophobic/hydrophilic coatings are highly desirable in antifogging, oil-water separation, and detergent-free cleaning. However, such coatings require special chemical structure, i.e., perfluorinated backbone and polar end-groups, and are too expensive for real-life application. Here, we have developed an UV-based photochemical approach to make nanometer-thick perfluoropolyethers without polar end-groups, which are not intrinsically simultaneously oleophobic/hydrophilic but cost-effective, become simultaneously oleophobic/hydrophilic. The contact angle, ellipsometry, and X-ray photoelectron spectroscopy (XPS) results indicated that the UV irradiation results in the covalent bonding between the polymer and the substrate, which renders more ordered packing of polymer chains and thus the appropriately small interchain distance. As a result, the small water molecules penetrate the polymer network while large oil molecules do not. As a result, the oil contact angle is larger than the water contact angle and the coating shows the simultaneous oleophobicity/hydrophilicity. Moreover, we also demonstrated that this nanometer-thick simultaneously oleophobic/hydrophilic coating has improved long-term antifogging performance and detergent-free cleaning capability and is mechanically robust. The photochemical approach established here potentially can be applied on many other polymers and greatly accelerate the development and application of simultaneously oleophobic/hydrophilic coatings.

  13. Scanning, non-contact, hybrid broadband diffuse optical spectroscopy and diffuse correlation spectroscopy system

    PubMed Central

    Johansson, Johannes D.; Mireles, Miguel; Morales-Dalmau, Jordi; Farzam, Parisa; Martínez-Lozano, Mar; Casanovas, Oriol; Durduran, Turgut

    2016-01-01

    A scanning system for small animal imaging using non-contact, hybrid broadband diffuse optical spectroscopy (ncDOS) and diffuse correlation spectroscopy (ncDCS) is presented. The ncDOS uses a two-dimensional spectrophotometer retrieving broadband (610-900 nm) spectral information from up to fifty-seven source-detector distances between 2 and 5 mm. The ncDCS data is simultaneously acquired from four source-detector pairs. The sample is scanned in two dimensions while tracking variations in height. The system has been validated with liquid phantoms, demonstrated in vivo on a human fingertip during an arm cuff occlusion and on a group of mice with xenoimplanted renal cell carcinoma. PMID:26977357

  14. Holographic tissue dynamics spectroscopy

    NASA Astrophysics Data System (ADS)

    Nolte, David D.; An, Ran; Turek, John; Jeong, Kwan

    2011-08-01

    Tissue dynamics spectroscopy uses digital holography as a coherence gate to extract depth-resolved quasi-elastic dynamic light scattering from inside multicellular tumor spheroids. The temporal speckle contrast provides endogenous dynamical images of proliferating and hypoxic or necrotic tissues. Fluctuation spectroscopy similar to diffusing wave spectroscopy is performed on the dynamic speckle to generate tissue-response spectrograms that track time-resolved changes in intracellular motility in response to environmental perturbations. The spectrograms consist of several frequency bands that range from 0.005 to 5 Hz. The fluctuation spectral density and temporal autocorrelations show the signature of constrained anomalous diffusion, but with large fluctuation amplitudes caused by active processes far from equilibrium. Differences in the tissue-response spectrograms between the proliferating outer shell and the hypoxic inner core differentiate normal from starved conditions. The differential spectrograms provide an initial library of tissue-response signatures to environmental conditions of temperature, osmolarity, pH, and serum growth factors.

  15. Holographic tissue dynamics spectroscopy.

    PubMed

    Nolte, David D; An, Ran; Turek, John; Jeong, Kwan

    2011-08-01

    Tissue dynamics spectroscopy uses digital holography as a coherence gate to extract depth-resolved quasi-elastic dynamic light scattering from inside multicellular tumor spheroids. The temporal speckle contrast provides endogenous dynamical images of proliferating and hypoxic or necrotic tissues. Fluctuation spectroscopy similar to diffusing wave spectroscopy is performed on the dynamic speckle to generate tissue-response spectrograms that track time-resolved changes in intracellular motility in response to environmental perturbations. The spectrograms consist of several frequency bands that range from 0.005 to 5 Hz. The fluctuation spectral density and temporal autocorrelations show the signature of constrained anomalous diffusion, but with large fluctuation amplitudes caused by active processes far from equilibrium. Differences in the tissue-response spectrograms between the proliferating outer shell and the hypoxic inner core differentiate normal from starved conditions. The differential spectrograms provide an initial library of tissue-response signatures to environmental conditions of temperature, osmolarity, pH, and serum growth factors.

  16. The question of simultaneity in multisensory integration

    NASA Astrophysics Data System (ADS)

    Leone, Lynnette; McCourt, Mark E.

    2012-03-01

    Early reports of audiovisual (AV) multisensory integration (MI) indicated that unisensory stimuli must evoke simultaneous physiological responses to produce decreases in reaction time (RT) such that for unisensory stimuli with unequal RTs the stimulus eliciting the faster RT had to be delayed relative to the stimulus eliciting the slower RT. The "temporal rule" states that MI depends on the temporal proximity of unisensory stimuli, the neural responses to which must fall within a window of integration. Ecological validity demands that MI should occur only for simultaneous events (which may give rise to non-simultaneous neural activations). However, spurious neural response simultaneities which are unrelated to singular environmental multisensory occurrences must somehow be rejected. Using an RT/race model paradigm we measured AV MI as a function of stimulus onset asynchrony (SOA: +/-200 ms, 50 ms intervals) under fully dark adapted conditions for visual (V) stimuli that were either weak (scotopic 525 nm flashes; 511 ms mean RT) or strong (photopic 630 nm flashes; 356 ms mean RT). Auditory (A) stimulus (1000 Hz pure tone) intensity was constant. Despite the 155 ms slower mean RT to the scotopic versus photopic stimulus, facilitative AV MI in both conditions nevertheless occurred exclusively at an SOA of 0 ms. Thus, facilitative MI demands both physical and physiological simultaneity. We consider the mechanisms by which the nervous system may take account of variations in response latency arising from changes in stimulus intensity in order to selectively integrate only those physiological simultaneities that arise from physical simultaneities.

  17. Spectroscopy of francium

    SciTech Connect

    Simsarian, J. E.; Grossman, J. S.; Orozco, L. A.; Pearson, M.; Sprouse, G. D.; Zhao, W. Z.

    1999-01-15

    Francium is the least studied of the alkali atoms because it has no stable isotopes. We have performed precision spectroscopy on cold Fr atoms in a magneto optical trap. We have determined the location of the first two excited states of the S series by two-photon spectroscopy. We have measured the lifetimes of the 7p levels with a precision better than 0.5%. Our measurements test the many-body perturbation theory ab initio calculations of the dipole matrix element to very high accuracy in this relativistic alkali.

  18. Practical Amateur Spectroscopy

    NASA Astrophysics Data System (ADS)

    Tonkin, Stephen F.

    Because today's amateur astronomical telescopes are both powerful and affordable, spectroscopy - once the province of professionals - is becoming more and more popular. Various spectroscopes, at prices to suit everyone, are now available "off the shelf". Practical Amateur Spectroscopy contains everything an amateur needs to grasp the basic principles, to begin observing, and to understand just what the spectra show. Contributions by leading practical amateurs from America and Europe cover a very wide range of amateur equipment and techniques. One even describes how an audio CD can be used to show solar emission and absorption lines!

  19. Dual-axis vapor cell for simultaneous laser frequency stabilization on disparate optical transitions

    SciTech Connect

    Jayakumar, Anupriya Plotkin-Swing, Benjamin; Jamison, Alan O.; Gupta, Subhadeep

    2015-07-15

    We have developed a dual-axis ytterbium (Yb) vapor cell and used it to simultaneously address the two laser cooling transitions in Yb at wavelengths 399 nm and 556 nm, featuring the disparate linewidths of 2π × 29 MHz and 2π × 182 KHz, respectively. By utilizing different optical paths for the two wavelengths, we simultaneously obtain comparable optical densities suitable for saturated absorption spectroscopy for both the transitions and keep both the lasers frequency stabilized over several hours. We demonstrate that by appropriate control of the cell temperature profile, two atomic transitions differing in relative strength across a large range of over three orders of magnitude can be simultaneously addressed, making the device adaptable to a variety of spectroscopic needs. We also show that our observations can be understood with a simple theoretical model of the Yb vapor.

  20. Advanced Spectroscopy Technique for Biomedicine

    NASA Astrophysics Data System (ADS)

    Zhao, Jianhua; Zeng, Haishan

    This chapter presents an overview of the applications of optical spectroscopy in biomedicine. We focus on the optical design aspects of advanced biomedical spectroscopy systems, Raman spectroscopy system in particular. Detailed components and system integration are provided. As examples, two real-time in vivo Raman spectroscopy systems, one for skin cancer detection and the other for endoscopic lung cancer detection, and an in vivo confocal Raman spectroscopy system for skin assessment are presented. The applications of Raman spectroscopy in cancer diagnosis of the skin, lung, colon, oral cavity, gastrointestinal tract, breast, and cervix are summarized.

  1. Mössbauer Spectroscopy

    NASA Astrophysics Data System (ADS)

    Dickson, Dominic P. E.; Berry, Frank J.

    1986-12-01

    Preface; 1. Principles of Mössbauer spectroscopy Dominic P. E. Dickson and Frank J. Berry; 2. Mössbauer spectroscopy and the chemical bond R. V. Parish; 3. Mössbauer spectroscopy as a structural probe Gary J. Long; 4. Mössbauer spectroscopy of magnetic solids M. F. Thomas and C. E. Johnson; 5. Time-dependent effects and relaxation in Mössbauer spectroscopy S. Dattagupta; 6. The dynamics of nuclei studied by Mössbauer spectroscopy E. R. Bauminger and I. Nowik; References; Index.

  2. Spectroscopy with Supersonic Jets.

    ERIC Educational Resources Information Center

    Skinner, Anne R.; Chandler, Dean W.

    1980-01-01

    Discusses a new technique that enables spectroscopists to study gas phase molecules at temperatures below 1 K, without traditional cryogenic apparatus. This technique uses supersonic jets as samples for gas molecular spectroscopy. Highlighted are points in the theory of supersonic flow which are important for applications in molecular…

  3. FTIR Rotational Spectroscopy.

    ERIC Educational Resources Information Center

    Woods, Ron; Henderson, Giles

    1987-01-01

    Presented are representative examples of the spectra and the analyses for a linear molecule (HC1), a symmetric top molecule (NH3), and an asymmetric top (H2O). Any combination of these projects could be incorporated in a physical chemistry or molecular spectroscopy laboratory. (RH)

  4. Simultaneous sensorimotor adaptation and sequence learning.

    PubMed

    Overduin, Simon A; Richardson, Andrew G; Bizzi, Emilio; Press, Daniel Z

    2008-01-01

    Sensorimotor adaptation and sequence learning have often been treated as distinct forms of motor learning. But frequently the motor system must acquire both types of experience simultaneously. Here, we investigated the interaction of these two forms of motor learning by having subjects adapt to predictable forces imposed by a robotic manipulandum while simultaneously reaching to an implicit sequence of targets. We show that adaptation to novel dynamics and learning of a sequence of movements can occur simultaneously and without significant interference or facilitation. When both conditions were presented simultaneously to subjects, their trajectory error and reaction time decreased to the same extent as those of subjects who experienced the force field or sequence independently.

  5. Broadband Rotational Spectroscopy

    NASA Astrophysics Data System (ADS)

    Pate, Brooks

    2014-06-01

    The past decade has seen several major technology advances in electronics operating at microwave frequencies making it possible to develop a new generation of spectrometers for molecular rotational spectroscopy. High-speed digital electronics, both arbitrary waveform generators and digitizers, continue on a Moore's Law-like development cycle that started around 1993 with device bandwidth doubling about every 36 months. These enabling technologies were the key to designing chirped-pulse Fourier transform microwave (CP-FTMW) spectrometers which offer significant sensitivity enhancements for broadband spectrum acquisition in molecular rotational spectroscopy. A special feature of the chirped-pulse spectrometer design is that it is easily implemented at low frequency (below 8 GHz) where Balle-Flygare type spectrometers with Fabry-Perot cavity designs become technologically challenging due to the mirror size requirements. The capabilities of CP-FTMW spectrometers for studies of molecular structure will be illustrated by the collaborative research effort we have been a part of to determine the structures of water clusters - a project which has identified clusters up to the pentadecamer. A second technology trend that impacts molecular rotational spectroscopy is the development of high power, solid state sources in the mm-wave/THz regions. Results from the field of mm-wave chirped-pulse Fourier transform spectroscopy will be described with an emphasis on new problems in chemical dynamics and analytical chemistry that these methods can tackle. The third (and potentially most important) technological trend is the reduction of microwave components to chip level using monolithic microwave integrated circuits (MMIC) - a technology driven by an enormous mass market in communications. Some recent advances in rotational spectrometer designs that incorporate low-cost components will be highlighted. The challenge to the high-resolution spectroscopy community - as posed by Frank De

  6. An approach to directly probe simultaneity

    NASA Astrophysics Data System (ADS)

    Kipreos, Edward T.; Balachandran, Riju S.

    2016-08-01

    The theory of special relativity derives from the Lorentz transformation. The Lorentz transformation implies differential simultaneity and light speed isotropy. Experiments to probe differential simultaneity should be able to distinguish the Lorentz transformation from a kinematically-similar alternate transformation that predicts absolute simultaneity, the absolute Lorentz transformation. Here, we describe how published optical tests of light speed isotropy/anisotropy cannot distinguish between the two transformations. We show that the shared equations of the two transformations, from the perspective of the “stationary” observer, are sufficient to predict null results in optical resonator experiments and in tests of frequency changes in one-way light paths. In an influential 1910 exposition on differential simultaneity, Comstock described how a “stationary” observer would observe different clock readings for spatially-separated “moving” clocks. The difference in clock readings is an integral aspect of differential simultaneity. We derive the equation for the difference in clock readings and show that it is equivalent to the Sagnac correction that describes light speed anisotropies in satellite communications. We describe an experimental strategy that can measure the differences in spatially-separated clock times to allow a direct probe of the nature of simultaneity.

  7. Parallel reconstruction in accelerated multi voxel MR Spectroscopy

    PubMed Central

    Boer, V.O.; Klomp, D.W.J.; Laterra, J.; Barker, P.B.

    2015-01-01

    Purpose To develop the simultaneous acquisition of multiple voxels in localized MR spectroscopy using sensitivity encoding, allowing reduced total scan time compared to conventional sequential single voxel acquisition methods. Methods Dual volume localization was used to simultaneously excite voxels in both hemispheres. Receiver coil sensitivity profiles were used to unfold the data. To demonstrate the method, MRS voxels in the left and right hippocampus were measured at 3T, and left and right motor cortex at 7T. Spectra were compared to conventional single voxel acquisitions. Spectra were also recorded from the lesion and contralateral hemisphere of a patient with a low grade oligodendroglioma at 7T. Results It was possible to generate signal in two voxels simultaneously and separate the signal originating from the different locations, with spectral results almost identical to those observed using conventional single voxel methods. The method results in an increased chemical shift displacement artifact, which might be improved by advanced pulse designs, and a noise increase due to the unfolding ‘g-factor’, which was larger at 3T than 7T. Conclusion The simultaneous acquisition of voxels for MR spectroscopy is possible by using modulated slice selective pulses and receive coil sensitivity profiles to unfold the resulting signals. PMID:26151840

  8. Determination of deep trapping lifetime in organic semiconductors using impedance spectroscopy

    SciTech Connect

    Takagi, Kenichiro; Nagase, Takashi; Kobayashi, Takashi; Naito, Hiroyoshi

    2016-02-01

    A method for determining deep trapping lifetime in semiconductors using an impedance spectroscopy is proposed. A unique feature of the method is the simultaneous determination of the drift mobility and deep trapping lifetime in thin-film electronic devices. The validity of the proposed method is examined by numerical calculation. Simultaneous determinations of the drift mobility and deep trapping lifetime using this method are demonstrated in prototypical hole transporting organic semiconductors.

  9. Combined fiber probe for fluorescence lifetime and Raman spectroscopy.

    PubMed

    Dochow, Sebastian; Ma, Dinglong; Latka, Ines; Bocklitz, Thomas; Hartl, Brad; Bec, Julien; Fatakdawala, Hussain; Marple, Eric; Urmey, Kirk; Wachsmann-Hogiu, Sebastian; Schmitt, Michael; Marcu, Laura; Popp, Jürgen

    2015-11-01

    In this contribution we present a dual modality fiber optic probe combining fluorescence lifetime imaging (FLIm) and Raman spectroscopy for in vivo endoscopic applications. The presented multi-spectroscopy probe enables efficient excitation and collection of fluorescence lifetime signals for FLIm in the UV/visible wavelength region, as well as of Raman spectra in the near-IR for simultaneous Raman/FLIm imaging. The probe was characterized in terms of its lateral resolution and distance dependency of the Raman and FLIm signals. In addition, the feasibility of the probe for in vivo FLIm and Raman spectral characterization of tissue was demonstrated. Graphical Abstract An image comparison between FLIm and Raman spectroscopy acquired with the bimodal probe onseveral tissue samples.

  10. Probing single cells of purple sulfur bacteria with Raman spectroscopy: carotenoids and elemental sulfur.

    PubMed

    Oren, Aharon; Mana, Lily; Jehlička, Jan

    2015-03-01

    We explored the use of Raman spectroscopy to simultaneously monitor the presence of different biomarkers (carotenoids, elemental sulfur) within single cells of the purple sulfur photosynthetic bacteria Allochromatium vinosum and A. warmingii. Raman microspectrometry using excitation at 532 nm allowed the detection of different carotenoids. Raman signals of elemental sulfur appeared soon after feeding starved cells with sulfide. Raman spectroscopy is thus a convenient and sensitive technique to qualitatively and semiquantitatively assess the presence of different compounds of interest within single bacterial cells.

  11. Simultaneous solution-based generation and characterization of crystalline bismuth thin film by femtosecond laser spectroscopy

    SciTech Connect

    Zhu, Liangdong; Keszler, Douglas A.; Fang, Chong; Saha, Sumit; Liu, Weimin; Wang, Yanli

    2015-08-10

    We demonstrate generation and characterization of crystalline bismuth thin film from triphenyl bismuth in methanol. Upon ultraviolet (267 nm) femtosecond laser irradiation of the solution, a thin film of elemental bismuth forms on the inner side of the sample cuvette, confirmed by detection of the coherent A{sub 1g} optical phonon mode of crystalline bismuth at ∼90 cm{sup −1}. Probe pulses at 267 and 400 nm are used to elucidate the excited state potential energy surface and photochemical reaction coordinate of triphenyl bismuth in solution with femtosecond resolution. The observed phonon mode blueshifts with increasing irradiation time, likely due to the gradual thickening of nascent bismuth thin film to ∼80 nm in 90 min. From transient absorption with the 400 nm probe, we observe a dominant ∼4 ps decay time constant of the excited-state absorption signal, which is attributed to a characteristic metal-ligand bond-weakening/breaking intermediate enroute to crystalline metallic thin film from the solution precursor molecules. Our versatile optical setup thus opens an appealing avenue to characterize the laser-induced crystallization process in situ and prepare high-quality thin films and nanopatterns directly from solution phase.

  12. Simultaneous Determination of Metamizole, Thiamin and Pyridoxin Using UV-Spectroscopy in Combination with Multivariate Calibration

    PubMed Central

    Chotimah, Chusnul; Sudjadi; Riyanto, Sugeng; Rohman, Abdul

    2015-01-01

    Purpose: Analysis of drugs in multicomponent system officially is carried out using chromatographic technique, however, this technique is too laborious and involving sophisticated instrument. Therefore, UV-VIS spectrophotometry coupled with multivariate calibration of partial least square (PLS) for quantitative analysis of metamizole, thiamin and pyridoxin is developed in the presence of cyanocobalamine without any separation step. Methods: The calibration and validation samples are prepared. The calibration model is prepared by developing a series of sample mixture consisting these drugs in certain proportion. Cross validation of calibration sample using leave one out technique is used to identify the smaller set of components that provide the greatest predictive ability. The evaluation of calibration model was based on the coefficient of determination (R2) and root mean square error of calibration (RMSEC). Results: The results showed that the coefficient of determination (R2) for the relationship between actual values and predicted values for all studied drugs was higher than 0.99 indicating good accuracy. The RMSEC values obtained were relatively low, indicating good precision. The accuracy and presision results of developed method showed no significant difference compared to those obtained by official method of HPLC. Conclusion: The developed method (UV-VIS spectrophotometry in combination with PLS) was succesfully used for analysis of metamizole, thiamin and pyridoxin in tablet dosage form. PMID:26819934

  13. Observations of stimulated Raman scattering using simultaneous Thomson scattering, fast electron spectroscopy, and infrared diagnostics

    SciTech Connect

    McIntosh, G.; Meyer, J.; Yazhou, Z.

    1986-10-01

    Stimulated Raman scattering (SRS) in a CO/sub 2/ laser(lambda/sub 0/ -- 10.6 ..mu..m) produced plasma has been studied experimentally. The enhanced electron plasma wave (epw) fluctuations observed with ruby laser Thomson scattering have been compared with the scattered infrared (IR) spectra and the high-energy (near 100 keV) electrons. No scattered IR light in the range 1.5lambda/sub 0/

  14. High resolution hypernuclear spectroscopy

    SciTech Connect

    F. Garibaldi

    2005-02-01

    Hypernuclear spectroscopy provides fundamental information for understanding the effective ?-Nucleon interaction. Jefferson Laboratory experiment E94-107 was designed to perform high resolution hypernuclear spectroscopy by electroproduction of strangeness in four 1p-shell nuclei: 12C, 9Be, 16O, and 7Li. The first part of the experiment on 12C and 9Be has been performed in January and April-May 2004 in Hall A at Jefferson Lab. Significant modifications were made to the standard Hall A apparatus for this challenging experiment: two septum magnets and a RICH detector have been added to get reasonable counting rates and excellent particle identification, as required for the experiment. A description of the apparatus and the preliminary analysis results are presented here.

  15. Raman spectroscopy in astrobiology.

    PubMed

    Jorge Villar, Susana E; Edwards, Howell G M

    2006-01-01

    Raman spectroscopy is proposed as a valuable analytical technique for planetary exploration because it is sensitive to organic and inorganic compounds and able to unambiguously identify key spectral markers in a mixture of biological and geological components; furthermore, sample manipulation is not required and any size of sample can be studied without chemical or mechanical pretreatment. NASA and ESA are considering the adoption of miniaturised Raman spectrometers for inclusion in suites of analytical instrumentation to be placed on robotic landers on Mars in the near future to search for extinct or extant life signals. In this paper we review the advantages and limitations of Raman spectroscopy for the analysis of complex specimens with relevance to the detection of bio- and geomarkers in extremophilic organisms which are considered to be terrestrial analogues of possible extraterrestial life that could have developed on planetary surfaces.

  16. Precision Muonium Spectroscopy

    NASA Astrophysics Data System (ADS)

    Jungmann, Klaus P.

    2016-09-01

    The muonium atom is the purely leptonic bound state of a positive muon and an electron. It has a lifetime of 2.2 µs. The absence of any known internal structure provides for precision experiments to test fundamental physics theories and to determine accurate values of fundamental constants. In particular ground state hyperfine structure transitions can be measured by microwave spectroscopy to deliver the muon magnetic moment. The frequency of the 1s-2s transition in the hydrogen-like atom can be determined with laser spectroscopy to obtain the muon mass. With such measurements fundamental physical interactions, in particular quantum electrodynamics, can also be tested at highest precision. The results are important input parameters for experiments on the muon magnetic anomaly. The simplicity of the atom enables further precise experiments, such as a search for muonium-antimuonium conversion for testing charged lepton number conservation and searches for possible antigravity of muons and dark matter.

  17. BATSE spectroscopy detector calibration

    NASA Technical Reports Server (NTRS)

    Band, D.; Ford, L.; Matteson, J.; Lestrade, J. P.; Teegarden, B.; Schaefer, B.; Cline, T.; Briggs, M.; Paciesas, W.; Pendleton, G.

    1992-01-01

    We describe the channel-to-energy calibration of the Spectroscopy Detectors of the Burst and Transient Source Experiment (BATSE) on the Compton Gamma Ray Observatory (GRO). These detectors consist of NaI(TI) crystals viewed by photomultiplier tubes whose output in turn is measured by a pulse height analyzer. The calibration of these detectors has been complicated by frequent gain changes and by nonlinearities specific to the BATSE detectors. Nonlinearities in the light output from the NaI crystal and in the pulse height analyzer are shifted relative to each other by changes in the gain of the photomultiplier tube. We present the analytical model which is the basis of our calibration methodology, and outline how the empirical coefficients in this approach were determined. We also describe the complications peculiar to the Spectroscopy Detectors, and how our understanding of the detectors' operation led us to a solution to these problems.

  18. Inelastic electron tunneling spectroscopy

    NASA Technical Reports Server (NTRS)

    Khanna, S. K.; Lambe, J.

    1983-01-01

    Inelastic electron tunneling spectroscopy is a useful technique for the study of vibrational modes of molecules adsorbed on the surface of oxide layers in a metal-insulator-metal tunnel junction. The technique involves studying the effects of adsorbed molecules on the tunneling spectrum of such junctions. The data give useful information about the structure, bonding, and orientation of adsorbed molecules. One of the major advantages of inelastic electron tunneling spectroscopy is its sensitivity. It is capable of detecting on the order of 10 to the 10th molecules (a fraction of a monolayer) on a 1 sq mm junction. It has been successfully used in studies of catalysis, biology, trace impurity detection, and electronic excitations. Because of its high sensitivity, this technique shows great promise in the area of solid-state electronic chemical sensing.

  19. Plasma Spectroscopy in ISTTOK

    NASA Astrophysics Data System (ADS)

    Figueiredo, J.; Gomes, R. B.; Pereira, T.; Fernandes, H.; Sharakovski, A.

    2008-04-01

    Plasma spectroscopy is a well established technique for impurities study in fusion plasmas. A brief description of the several spectroscopic systems which have been in operation at ISTTOK is given. In ISTTOK a passive spectroscopy diagnostic system is being used to perform spectral and spatial characterization in the 300-850 nm wavelength range. The system used to perform that work consist essentially of a cooled CCD camera coupled to a half a meter imaging spectrograph with collection optics based on a multi-fiber set to allow for enhanced spatial resolution. Experimental data is shown underlining typical plasma fusion spectral lines and specific ISTTOK characteristics. A web based data access tool is presented that allows the spectral plasma survey in specific wavelength ranges. The information provided by this survey has been used to select suitable transmission filters for a diagnostic, currently under development, to measure Zeff parameter for ISTTOK plasmas. A description of this diagnostic is also presented.

  20. Chiral rotational spectroscopy

    NASA Astrophysics Data System (ADS)

    Cameron, Robert P.; Götte, Jörg B.; Barnett, Stephen M.

    2016-09-01

    We introduce chiral rotational spectroscopy, a technique that enables the determination of the orientated optical activity pseudotensor components BX X, BY Y, and BZ Z of chiral molecules, in a manner that reveals the enantiomeric constitution of a sample and provides an incisive signal even for a racemate. Chiral rotational spectroscopy could find particular use in the analysis of molecules that are chiral solely by virtue of their isotopic constitution and molecules with multiple chiral centers. A basic design for a chiral rotational spectrometer together with a model of its functionality is given. Our proposed technique offers the more familiar polarizability components αX X, αY Y, and αZ Z as by-products, which could see it find use even for achiral molecules.

  1. Charm Baryon Spectroscopy

    NASA Astrophysics Data System (ADS)

    Chistov, R.

    2016-02-01

    B-factories Belle and BaBar during its operation made not only measurements connected with B-meson decays but also numerous observation and measurements in charm physics. In particular, their results on charm baryon decays and spectroscopy have enlarged and enriched the current picture of heavy flavour hadrons. In this talk we overview current status of charm baryons and their excited states.

  2. Coherent spectroscopy of semiconductors.

    PubMed

    Cundiff, Steven T

    2008-03-31

    The coherent optical response of semiconductors has been the subject of substantial research over the last couple of decades. The interest has been motivated by unique aspects of the interaction between light and semiconductors that are revealed by coherent techniques. The ability to probe the dynamics of charge carriers has been a significant driver. This paper presents a review of selected results in coherent optical spectroscopy of semiconductors.

  3. Applications in Photoacoustic Spectroscopy.

    DTIC Science & Technology

    1979-08-01

    25 Chopping frequency vs. PA signal ... ..... 30 Concentration vs. PA signal .. ........ .. 35 III Photoacoustic Detection of Thin Films ...1,21, researchers today utilize PA spectroscopy to investigate the optical and thermal properties of solids (3,4] and solutions (5]. Reviews of the basic... optical properties , the thermal properties and the physical dimensions of the 2 sample, the cell, and the coupling gas. Studies to date have been somewhat

  4. Quantum Gravitational Spectroscopy

    SciTech Connect

    Nesvizhevsky, Valery V.; Antoniadis, Ignatios; Baessler, Stefan; Pignol, Guillaume

    2015-01-01

    We report that one of the main goals for improving the accuracy of quantum gravitational spectroscopy with neutrons is searches for extra short-range fundamental forces. We discuss also any progress in all competing nonneutron methods as well as constraints at other characteristic distances. Among major methodical developments related to the phenomenon of gravitational quantum states are the detailed theoretical analysis and the planning experiments on observation of gravitational quantum states of antihydrogen atoms.

  5. 2008 Vibrational Spectroscopy

    SciTech Connect

    Philip J. Reid

    2009-09-21

    The conference focuses on using vibrational spectroscopy to probe structure and dynamics of molecules in gases, liquids, and interfaces. The goal is to bring together a collection of researchers who share common interests and who will gain from discussing work at the forefront of several connected areas. The intent is to emphasize the insights and understanding that studies of vibrations provide about a variety of systems.

  6. Dielectric spectroscopy of polyaniline

    SciTech Connect

    Calleja, R.D.; Matveeva, E.M.

    1993-12-31

    Polyaniline films (PANI) are being considered as attractive new galvanic sources, electrochromic displays, chemical sensors, etc. So far much work has been done to study their optical, electrochemical and electrical properties. However, there are still doubts about the basic electric conductivity mechanisms of PANI. The aim of this paper is to study the influence of water molecules and acid anions on the properties of PANI films by dielectric spectroscopy.

  7. Theory and spectroscopy

    NASA Astrophysics Data System (ADS)

    Stanton, John F.

    2015-05-01

    The interaction between quantum-mechanical theory and spectroscopy is one of the most fertile interfaces in all of science, and has a richly storied history. Of course it was spectroscopy that provided essentially all of the evidence that not all was well (or, perhaps more correctly put, complete) with the world of 19th century classical physics. From the discoveries of the dark lines in the solar spectrum by Fraunhöfer in 1814 to the curiously simple geometric formula discovered seventy years later that described the hydrogen atom spectrum, spectroscopy and spectroscopists have consistently identified the areas of atomic and molecular science that are most in need of hard thinking by theoreticians. The rest of the story, of course, is well-known: spectroscopic results were used to understand and motivate the theory of radioactivity and ultimately the quantum theory, first in its immature form that was roughly contemporaneous with the first World War, and then the Heisenberg-Schrödinger-Dirac version that has withstood the test of time. Since the basic principles of quantum mechanics ware first understood, the subject has been successfully used to understand the patterns found in spectra, and how these relate to molecular structure, symmetry, energy levels, and dynamics. But further understanding required to attain these intellectual achievements has often come only as a result of vital and productive interactions between theoreticians and spectroscopists (of course, many people have strengths in both areas). And indeed, a field that might be termed "theoretical spectroscopy" was cultivated and is now an important part of modern molecular science.

  8. Colloquium: Graphene spectroscopy

    NASA Astrophysics Data System (ADS)

    Basov, D. N.; Fogler, M. M.; Lanzara, A.; Wang, Feng; Zhang, Yuanbo

    2014-07-01

    Spectroscopic studies of electronic phenomena in graphene are reviewed. A variety of methods and techniques are surveyed, from quasiparticle spectroscopies (tunneling, photoemission) to methods probing density and current response (infrared optics, Raman) to scanning probe nanoscopy and ultrafast pump-probe experiments. Vast complimentary information derived from these investigations is shown to highlight unusual properties of Dirac quasiparticles and many-body interaction effects in the physics of graphene.

  9. Layman friendly spectroscopy

    NASA Astrophysics Data System (ADS)

    Sentic, Stipo; Sessions, Sharon

    Affordable consumer grade spectroscopes (e.g. SCiO, Qualcomm Tricorder XPRIZE) are becoming more available to the general public. We introduce the concepts of spectroscopy to the public and K12 students and motivate them to delve deeper into spectroscopy in a dramatic participatory presentation and play. We use diffraction gratings, lasers, and light sources of different spectral properties to provide a direct experience of spectroscopy techniques. Finally, we invite the audience to build their own spectroscope--utilizing the APS SpectraSnapp cell phone application--and study light sources surrounding them in everyday life. We recontextualize the stigma that science is hard (e.g. ``Math, Science Popular Until Students Realize They're Hard,'' The Wall Street Journal) by presenting the material in such a way that it demonstrates the scientific method, and aiming to make failure an impersonal scientific tool--rather than a measure of one's ability, which is often a reason for shying away from science. We will present lessons we have learned in doing our outreach to audiences of different ages. This work is funded by the APS Outreach Grant ``Captain, we have matter matters!'' We thank New Mexico Tech Physics Department and Physics Club for help and technical equipment.

  10. High Resolution Laboratory Spectroscopy

    NASA Astrophysics Data System (ADS)

    Brünken, S.; Schlemmer, S.

    2016-05-01

    In this short review we will highlight some of the recent advancements in the field of high-resolution laboratory spectroscopy that meet the needs dictated by the advent of highly sensitive and broadband telescopes like ALMA and SOFIA. Among these is the development of broadband techniques for the study of complex organic molecules, like fast scanning conventional absorption spectroscopy based on multiplier chains, chirped pulse instrumentation, or the use of synchrotron facilities. Of similar importance is the extension of the accessible frequency range to THz frequencies, where many light hydrides have their ground state rotational transitions. Another key experimental challenge is the production of sufficiently high number densities of refractory and transient species in the laboratory, where discharges have proven to be efficient sources that can also be coupled to molecular jets. For ionic molecular species sensitive action spectroscopic schemes have recently been developed to overcome some of the limitations of conventional absorption spectroscopy. Throughout this review examples demonstrating the strong interplay between laboratory and observational studies will be given.

  11. Analysis of the Aspergillus fumigatus Biofilm Extracellular Matrix by Solid-State Nuclear Magnetic Resonance Spectroscopy

    PubMed Central

    Reichhardt, Courtney; Ferreira, Jose A. G.; Joubert, Lydia-Marie; Clemons, Karl V.; Stevens, David A.

    2015-01-01

    Aspergillus fumigatus is commonly responsible for lethal fungal infections among immunosuppressed individuals. A. fumigatus forms biofilm communities that are of increasing biomedical interest due to the association of biofilms with chronic infections and their increased resistance to antifungal agents and host immune factors. Understanding the composition of microbial biofilms and the extracellular matrix is important to understanding function and, ultimately, to developing strategies to inhibit biofilm formation. We implemented a solid-state nuclear magnetic resonance (NMR) approach to define compositional parameters of the A. fumigatus extracellular matrix (ECM) when biofilms are formed in RPMI 1640 nutrient medium. Whole biofilm and isolated matrix networks were also characterized by electron microscopy, and matrix proteins were identified through protein gel analysis. The 13C NMR results defined and quantified the carbon contributions in the insoluble ECM, including carbonyls, aromatic carbons, polysaccharide carbons (anomeric and nonanomerics), aliphatics, etc. Additional 15N and 31P NMR spectra permitted more specific annotation of the carbon pools according to C-N and C-P couplings. Together these data show that the A. fumigatus ECM produced under these growth conditions contains approximately 40% protein, 43% polysaccharide, 3% aromatic-containing components, and up to 14% lipid. These fundamental chemical parameters are needed to consider the relationships between composition and function in the A. fumigatus ECM and will enable future comparisons with other organisms and with A. fumigatus grown under alternate conditions. PMID:26163318

  12. Experimental demonstration of quantitation errors in MR spectroscopy resulting from saturation corrections under changing conditions

    NASA Astrophysics Data System (ADS)

    Galbán, Craig J.; Ellis, Scott J.; Spencer, Richard G. S.

    2003-04-01

    Metabolite concentration measurements in in vivo NMR are generally performed under partially saturated conditions, with correction for partial saturation performed after data collection using a measured saturation factor. Here, we present an experimental test of the hypothesis that quantitation errors can occur due to application of such saturation factor corrections in changing systems. Thus, this extends our previous theoretical work on quantitation errors due to varying saturation factors. We obtained results for two systems frequently studied by 31P NMR, the ischemic rat heart and the electrically stimulated rat gastrocnemius muscle. The results are interpreted in light of previous theoretical work which defined the degree of saturation occurring in a one-pulse experiment for a system with given spin-lattice relaxation times, T1s, equilibrium magnetizations, M0s, and reaction rates. We found that (i) the assumption of constancy of saturation factors leads to quantitation errors on the order of 40% in inorganic phosphate; (ii) the dominant contributor to the quantitation errors in inorganic phosphate is most likely changes in T1; (iii) T1 and M0 changes between control and intervention periods, and chemical exchange contribute to different extents to quantitation errors in phosphocreatine and γ-ATP; (iv) relatively small increases in interpulse delay substantially decreased quantitation errors for metabolites in ischemic rat hearts; (v) random error due to finite SNR led to approximately 4% error in quantitation, and hence was a substantially smaller contributor than were changes in saturation factors.

  13. Analysis of the Aspergillus fumigatus Biofilm Extracellular Matrix by Solid-State Nuclear Magnetic Resonance Spectroscopy.

    PubMed

    Reichhardt, Courtney; Ferreira, Jose A G; Joubert, Lydia-Marie; Clemons, Karl V; Stevens, David A; Cegelski, Lynette

    2015-11-01

    Aspergillus fumigatus is commonly responsible for lethal fungal infections among immunosuppressed individuals. A. fumigatus forms biofilm communities that are of increasing biomedical interest due to the association of biofilms with chronic infections and their increased resistance to antifungal agents and host immune factors. Understanding the composition of microbial biofilms and the extracellular matrix is important to understanding function and, ultimately, to developing strategies to inhibit biofilm formation. We implemented a solid-state nuclear magnetic resonance (NMR) approach to define compositional parameters of the A. fumigatus extracellular matrix (ECM) when biofilms are formed in RPMI 1640 nutrient medium. Whole biofilm and isolated matrix networks were also characterized by electron microscopy, and matrix proteins were identified through protein gel analysis. The (13)C NMR results defined and quantified the carbon contributions in the insoluble ECM, including carbonyls, aromatic carbons, polysaccharide carbons (anomeric and nonanomerics), aliphatics, etc. Additional (15)N and (31)P NMR spectra permitted more specific annotation of the carbon pools according to C-N and C-P couplings. Together these data show that the A. fumigatus ECM produced under these growth conditions contains approximately 40% protein, 43% polysaccharide, 3% aromatic-containing components, and up to 14% lipid. These fundamental chemical parameters are needed to consider the relationships between composition and function in the A. fumigatus ECM and will enable future comparisons with other organisms and with A. fumigatus grown under alternate conditions.

  14. Simultaneous occurrences of floods in mesoscale catchments

    NASA Astrophysics Data System (ADS)

    Bàrdossy, Andràs

    2016-04-01

    Floods in mesoscale catchments are often the result of intense precipitation of varying duration. The spatial extent of precipitation is linked to the extent of flooding. The simultaneous occurrence of floods in different medium size catchments is often the reason for large scale floods. The spatial behavior of extreme precipitation and discharge can be investigated using copulas and extreme indices. The relationship between intense precipitations measured at different locations depends on the large scale meteorological conditions. Depending on the geographic location and the dominating weather pattern certain catchments have frequent simultaneous extremes while others behave in a complementary fashion. The purpose of this work is to investigate the simultaneous and complementary occurrence of floods in catchments using copulas conditioned on atmospheric circulation patterns (CPs). Circulation patterns responsible for simultaneous floods are identified using areal precipitation and/or unusual discharge increases. Patterns are identified using a fuzzy rule based approach based on anomalies of the 700 hPa surfaces. The rules are formed by maximizing the explained variance under the assumption of simultaneous and complementary behavior. The conditional copulas are investigated for extreme behavior. Besides the traditional bivariate investigations higher dimensional dependences are investigated using an entropy based approach.

  15. Stokes shift spectroscopy for breast cancer diagnosis

    NASA Astrophysics Data System (ADS)

    Jeyasingh, Ebenezar; Prakashrao, Aruna; Singaravelu, Ganesan

    2010-02-01

    The objective of this study is to assess the diagnostic potential of stokes shift (SS) spectroscopy (SSS) for normal and different pathological breast tissues such as fibroadenoma and infiltrating ductal carcinoma. The SS spectra is measured by simultaneously scanning both the excitation and emission wavelengths while keeping a fixed wavelength interval Δλ=20 nm between them. Characteristic, highly resolved peaks and significant spectral differences between normal and different pathological breast tissues were observed. The SS spectra of normal and different pathological breast tissues shows the distinct peaks around 300, 350, 450, 500 and 600 nm may be attributed to tryptophan, collagen, NADH, flavin and porphyrin respectively. Using SSS technique one can obtain all the key fluorophores in a single scan and hence they can be targeted as a tumor markers in this study. In order to quantify the altered spectral differences between normal and different pathological breast tissues are verified by different ratio parameters.

  16. Infrared spectroscopy of wafer-scale graphene.

    PubMed

    Yan, Hugen; Xia, Fengnian; Zhu, Wenjuan; Freitag, Marcus; Dimitrakopoulos, Christos; Bol, Ageeth A; Tulevski, George; Avouris, Phaedon

    2011-12-27

    We report spectroscopy results from the mid- to far-infrared on wafer-scale graphene, grown either epitaxially on silicon carbide or by chemical vapor deposition. The free carrier absorption (Drude peak) is simultaneously obtained with the universal optical conductivity (due to interband transitions) and the wavelength at which Pauli blocking occurs due to band filling. From these, the graphene layer number, doping level, sheet resistivity, carrier mobility, and scattering rate can be inferred. The mid-IR absorption of epitaxial two-layer graphene shows a less pronounced peak at 0.37 ± 0.02 eV compared to that in exfoliated bilayer graphene. In heavily chemically doped single-layer graphene, a record high transmission reduction due to free carriers approaching 40% at 250 μm (40 cm(-1)) is measured in this atomically thin material, supporting the great potential of graphene in far-infrared and terahertz optoelectronics.

  17. The Goodness of Simultaneous Fits in ISIS

    NASA Astrophysics Data System (ADS)

    Kühnel, Matthias; Falkner, Sebastian; Grossberger, Christoph; Ballhausen, Ralf; Dauser, Thomas; Schwarm, Fritz-Walter; Kreykenbohm, Ingo; Nowak, Michael A.; Pottschmidt, Katja; Ferrigno, Carlo; Rothschild, Richard E.; Martínez-Núñez, Silvia; Torrejón, José Miguel; Fürst, Felix; Klochkov, Dmitry; Staubert, Rüdiger; Kretschmar, Peter; Wilms, Jörn

    2016-02-01

    In a previous work, we introduced a tool for analyzing multiple datasets simultaneously, which has been implemented into ISIS. This tool was used to fit many spectra of X-ray binaries. However, the large number of degrees of freedom and individual datasets raise an issue about a good measure for a simultaneous fit quality. We present three ways to check the goodness of these fits: we investigate the goodness of each fit in all datasets, we define a combined goodness exploiting the logical structure of a simultaneous fit, and we stack the fit residuals of all datasets to detect weak features. These tools are applied to all RXTE-spectra from GRO 1008-57, revealing calibration features that are not detected significantly in any single spectrum. Stacking the residuals from the best-fit model for the Vela X-1 and XTE J1859+083 data evidences fluorescent emission lines that would have gone undetected otherwise.

  18. Simultaneous wireless electrophysiological and neurochemical monitoring

    NASA Astrophysics Data System (ADS)

    Murari, Kartikeya; Mollazadeh, Mohsen; Thakor, Nitish; Cauwenberghs, Gert

    2008-08-01

    Information processing and propagation in the central nervous system is mostly electrical in nature. At synapses, electrical signals cause the release of neurotransmitters like dopamine, glutamate etc., that are sensed by post-synaptic neurons resulting in signal propagation or inhibition. It can be very informative to monitor electrical and neurochemical signals simultaneously to understand the mechanisms underlying normal or abnormal brain function. We present an integrated system for the simultaneous wireless acquisition of neurophysiological and neurochemical activity. Applications of the system to neuroscience include monitoring EEG and glutamate in rat somatosensory cortex following global ischemia.

  19. Mass exchange during simultaneous grinding and dissolution

    SciTech Connect

    Aksel'rud, G.A.; Semenishin, E.M.; Kopyt, S.Ya.; Trotskii, V.I.

    1988-03-20

    Extraction of ore components of interest has a number of disadvantages, one of which being low efficiency. Combining the grinding and dissolution steps in one apparatus makes the process more efficient. Adoption of this technology, however, requires theoretical and mathematical studies. This paper reports the kinetics of simultaneous grinding and dissolution of copper-containing minerals. Simultaneous grinding and dissolution accelerated several fold the mass transfer of components of interest in the interaction of malachite and azurite with sulfuric acid solutions. The complete dissolution time was determined by adding the experimental rates of dissolution and abrasion.

  20. OPTOPUS spectroscopy of galaxies

    NASA Astrophysics Data System (ADS)

    Schnur, G. F. O.

    The spectra of selected H II regions in the center of the starburst galaxy NGC 1808 and of many faint galaxies surrounding the NGC 1808 were obtained simultaneously, using the Optopus fiber-optics spectrograph facility (described by Lund, 1986) at the ESO 3.6-m telescope. The preparation of Optopus plates (each of which employed more than 40 fibers), observations, and the procedures of data processing and Optopus calibration are described together with the problems caused by cosmic ray events. Preliminary results are included.

  1. Time-domain diffuse correlation spectroscopy

    PubMed Central

    Sutin, Jason; Zimmerman, Bernhard; Tyulmankov, Danil; Tamborini, Davide; Wu, Kuan Cheng; Selb, Juliette; Gulinatti, Angelo; Rech, Ivan; Tosi, Alberto; Boas, David A.; Franceschini, Maria Angela

    2016-01-01

    Physiological monitoring of oxygen delivery to the brain has great significance for improving the management of patients at risk for brain injury. Diffuse correlation spectroscopy (DCS) is a rapidly growing optical technology able to non-invasively assess the blood flow index (BFi) at the bedside. The current limitations of DCS are the contamination introduced by extracerebral tissue and the need to know the tissue’s optical properties to correctly quantify the BFi. To overcome these limitations, we have developed a new technology for time-resolved diffuse correlation spectroscopy. By operating DCS in the time domain (TD-DCS), we are able to simultaneously acquire the temporal point-spread function to quantify tissue optical properties and the autocorrelation function to quantify the BFi. More importantly, by applying time-gated strategies to the DCS autocorrelation functions, we are able to differentiate between short and long photon paths through the tissue and determine the BFi for different depths. Here, we present the novel device and we report the first experiments in tissue-like phantoms and in rodents. The TD-DCS method opens many possibilities for improved non-invasive monitoring of oxygen delivery in humans. PMID:28008417

  2. Vacuum-ultraviolet frequency-modulation spectroscopy.

    PubMed

    Hollenstein, U; Schmutz, H; Agner, J A; Sommavilla, M; Merkt, F

    2017-01-07

    Frequency-modulation (FM) spectroscopy has been extended to the vacuum-ultraviolet (VUV) range of the electromagnetic spectrum. Coherent VUV laser radiation is produced by resonance-enhanced sum-frequency mixing (νVUV=2νUV+ν2) in Kr and Xe using two near-Fourier-transform-limited laser pulses of frequencies νUV and ν2. Sidebands generated in the output of the second laser (ν2) using an electro-optical modulator operating at the frequency νmod are directly transferred to the VUV and used to record FM spectra. Demodulation is demonstrated both at νmod and 2νmod. The main advantages of the method compared to VUV absorption spectroscopy are its background-free nature, the fact is that its implementation using table-top laser equipment is straightforward and that it can be used to record VUV absorption spectra of cold samples in skimmed supersonic beams simultaneously with laser-induced-fluorescence and photoionization spectra. To illustrate these advantages, we present VUV FM spectra of Ar, Kr, and N2 in selected regions between 105000 cm(-1) and 122000 cm(-1).

  3. Noninvasive glucose sensing by transcutaneous Raman spectroscopy

    PubMed Central

    Shih, Wei-Chuan; Bechtel, Kate L.; Rebec, Mihailo V.

    2015-01-01

    Abstract. We present the development of a transcutaneous Raman spectroscopy system and analysis algorithm for noninvasive glucose sensing. The instrument and algorithm were tested in a preclinical study in which a dog model was used. To achieve a robust glucose test system, the blood levels were clamped for periods of up to 45 min. Glucose clamping and rise/fall patterns have been achieved by injecting glucose and insulin into the ear veins of the dog. Venous blood samples were drawn every 5 min and a plasma glucose concentration was obtained and used to maintain the clamps, to build the calibration model, and to evaluate the performance of the system. We evaluated the utility of the simultaneously acquired Raman spectra to be used to determine the plasma glucose values during the 8-h experiment. We obtained prediction errors in the range of ∼1.5−2  mM. These were in-line with a best-case theoretical estimate considering the limitations of the signal-to-noise ratio estimates. As expected, the transition regions of the clamp study produced larger predictive errors than the stable regions. This is related to the divergence of the interstitial fluid (ISF) and plasma glucose values during those periods. Two key contributors to error beside the ISF/plasma difference were photobleaching and detector drift. The study demonstrated the potential of Raman spectroscopy in noninvasive applications and provides areas where the technology can be improved in future studies. PMID:25688542

  4. Noninvasive glucose sensing by transcutaneous Raman spectroscopy

    NASA Astrophysics Data System (ADS)

    Shih, Wei-Chuan; Bechtel, Kate L.; Rebec, Mihailo V.

    2015-05-01

    We present the development of a transcutaneous Raman spectroscopy system and analysis algorithm for noninvasive glucose sensing. The instrument and algorithm were tested in a preclinical study in which a dog model was used. To achieve a robust glucose test system, the blood levels were clamped for periods of up to 45 min. Glucose clamping and rise/fall patterns have been achieved by injecting glucose and insulin into the ear veins of the dog. Venous blood samples were drawn every 5 min and a plasma glucose concentration was obtained and used to maintain the clamps, to build the calibration model, and to evaluate the performance of the system. We evaluated the utility of the simultaneously acquired Raman spectra to be used to determine the plasma glucose values during the 8-h experiment. We obtained prediction errors in the range of ˜1.5-2 mM. These were in-line with a best-case theoretical estimate considering the limitations of the signal-to-noise ratio estimates. As expected, the transition regions of the clamp study produced larger predictive errors than the stable regions. This is related to the divergence of the interstitial fluid (ISF) and plasma glucose values during those periods. Two key contributors to error beside the ISF/plasma difference were photobleaching and detector drift. The study demonstrated the potential of Raman spectroscopy in noninvasive applications and provides areas where the technology can be improved in future studies.

  5. The rheo-Raman microscope: Simultaneous chemical, conformational, mechanical, and microstructural measures of soft materials

    NASA Astrophysics Data System (ADS)

    Kotula, Anthony P.; Meyer, Matthew W.; De Vito, Francesca; Plog, Jan; Hight Walker, Angela R.; Migler, Kalman B.

    2016-10-01

    The design and performance of an instrument capable of simultaneous Raman spectroscopy, rheology, and optical microscopy are described. The instrument couples a Raman spectrometer and optical microscope to a rotational rheometer through an optically transparent base, and the resulting simultaneous measurements are particularly advantageous in situations where flow properties vary due to either chemical or conformational changes in molecular structure, such as in crystallization, melting, gelation, or curing processes. Instrument performance is demonstrated on two material systems that show thermal transitions. First, we perform steady state rotational tests, Raman spectroscopy, and polarized reflection microscopy during a melting transition in a cosmetic emulsion. Second, we perform small amplitude oscillatory shear measurements along with Raman spectroscopy and polarized reflection microscopy during crystallization of a high density polyethylene. The instrument can be applied to study structure-property relationships in a variety of soft materials including thermoset resins, liquid crystalline materials, colloidal suspensions undergoing sol-gel processes, and biomacromolecules. Official contribution of the National Institute of Standards and Technology; not subject to copyright in the United States.

  6. Dual-Comb Spectroscopy in the Open Air

    NASA Astrophysics Data System (ADS)

    Rieker, Greg B.; Klose, Andrew; Diddams, Scott; Coddington, Ian; Giorgetta, Fabrizio; Sinclair, Laura; Baumann, Esther; Truong, Gar-Wing; Ycas, Gabriel; Swann, William C.; Newbury, Nathan R.

    2015-06-01

    Dual-comb spectroscopy is arguably the natural successor to FTIR. Based on the interference between two frequency combs, this technique can record broadband spectra with a resolution better than 0.0003 wn. Like FTIR, dual-comb spectroscopy measures an entire spectrum simultaneously, allowing for suppression of systematic errors related to temporal dynamics of the sample. Unlike FTIR it records the entire spectrum with virtually no instrument lineshape or error in the frequency axis. The lack of moving parts in dual-comb spectroscopy means that spectra can be recorded in milliseconds to microseconds with the desired signal-to-noise being the only real constrain on the minimum recording time. Finally the high spacial beam quality of the frequency combs allows for increased sensitivity through long interaction paths either in free-space, multi-pass cells or enhancement cavities. This talk will explore the recent use of dual-comb spectroscopy in the near-infrared to measure atmospheric carbon dioxide, methane and water concentrations over a 2-km outdoor open-air path. Due to many of the strengths just mentioned, precisions of <1 ppm for CO_2 and <3 ppb for CH_4 in 5 min are achieved making this system very attractive for carbon monitoring at length scales relevant to carbon transport models. Additionally this presentation will address recent work on robust, compact, and portable dual-comb spectrometers as well as dual-comb spectroscopy further into the IR.

  7. Single nanowire extinction spectroscopy.

    PubMed

    Giblin, Jay; Vietmeyer, Felix; McDonald, Matthew P; Kuno, Masaru

    2011-08-10

    Here we show the first direct extinction spectra of single one-dimensional (1D) semiconductor nanostructures obtained at room temperature utilizing a spatial modulation approach. (1) For these materials, ensemble averaging in conventional extinction spectroscopy has limited our understanding of the interplay between carrier confinement and their electrostatic interactions. (2-4) By probing individual CdSe nanowires (NWs), we have identified and assigned size-dependent exciton transitions occurring across the visible. In turn, we have revealed the existence of room temperature 1D excitons in the narrowest NWs.

  8. Spectroscopy of Stellar Coronae

    NASA Astrophysics Data System (ADS)

    Laming, J. Martin

    I review the important spectroscopic results that have come from observations of stellar coronae, mainly by EUVE and ASCA, but also from HST. The plasma parameters that can be determined from such spectra include the electron density and temperature distributions, and relative element abundances. With high resolution spectra dynamical information can be obtained. Such parameters can then be used to put constraints on models of the heating and structure of stellar coronae. Throughout, I try to emphasise the similarities and differences between stellar coronal spectroscopy and that of the solar corona.

  9. Visible Light Spectroscopy of GEO Debris

    NASA Technical Reports Server (NTRS)

    Seitzer, Patrick; Lederer, Susan M.; Cowardin, Heather; Barker, Edwin S.; Abercromby, Kira J.

    2012-01-01

    Our goal is to understand the physical characteristics of debris at geosynchronous orbit (GEO). Our approach is to compare the observed reflectance as a function of wavelength with laboratory measurements of typical spacecraft surfaces to understand what the materials are likely to be. Because debris could be irregular in shape and tumbling at an unknown rate, rapid simultaneous measurements over a range of wavelengths are required. Acquiring spectra of optically faint objects with short exposure times to minimize these effects requires a large telescope. We describe optical spectroscopy obtained during 12-14 March 2012 with the IMACS imaging spectrograph on the 6.5-m 'Walter Baade' Magellan telescope at Las Campanas Observatory in Chile. When used in f/2 imaging mode for acquisition, this instrument has a field of view of 30 arc-minutes in diameter. After acquisition and centering of a GEO object, a 2.5 arc-second wide slit and a grism are moved into the beam for spectroscopy. We used a 200 l/mm grism blazed at 660 nm for wavelength coverage in the 500-900 nm region. Typical exposure times for spectra were 15-30 seconds. Spectra were obtained for five objects in the GEO regime listed as debris in the US Space Command public catalog, and one high area to mass ratio GEO object. In addition spectra were obtained of three cataloged IDCSP (Initial Defense Communications Satellite Program) satellites with known initial properties just below the GEO regime. All spectra were calibrated using white dwarf flux standards and solar analog stars. We will describe our experiences using Magellan, a telescope never used previously for orbital debris spectroscopy, and our initial results.

  10. Visible Light Spectroscopy of GEO Debris

    NASA Astrophysics Data System (ADS)

    Seitzer, P.; Abercromby, K. J.; Barker, E. S.; Cardona, T.; Lederer, S. M.; Cowardin, H.

    2012-09-01

    Our goal is to understand the physical characteristics of debris at geosynchronous orbit (GEO). Our approach is to compare the observed reflectance as a function of wavelength with laboratory measurements of typical spacecraft surfaces to understand what the materials are likely to be. Because debris could be irregular in shape and tumbling at an unknown rate, rapid simultaneous measurements over a range of wavelengths are required. Acquiring spectra of optically faint objects with short exposure times to minimize these effects requires a large telescope. We describe optical spectroscopy obtained with two imaging spectrographs on the 6.5-m Magellan telescopes at Las Campanas Observatory in Chile. Our first observing run was 12-14 March 2012 with the IMACS imaging spectrograph on the 'Walter Baade' telescope, which was followed by a run on 1-2 May 2012 on the 'Landon Clay' telescope. Both telescopes have spectrographs with an imaging mode for acquisition. After acquisition and centering of a GEO object, a slit and grism are moved into the beam for spectroscopy. We used low resolution grisms blazed near 600 nm for wavelength coverage in the 400-800 nm region. Typical exposure times for spectra were 15-30 seconds. Spectra were obtained for objects in the GEO regime listed as debris in the US Space Command public catalog, and one high area to mass ratio GEO object. In addition spectra were obtained of IDCSP (Initial Defense Communications Satellite Program) satellites with known initial properties just below the GEO regime. All spectra were calibrated using white dwarf flux standards and solar analog stars. We will describe our experiences using Magellan, a telescope never used previously for orbital debris spectroscopy, and our initial results. 1. This work is supported by NASAs Orbital Debris Program Office, Johnson Space Center, Houston, Texas, USA. 2. This paper includes data gathered with the 6.5 meter Magellan Telescopes located at Las Campanas Observatory, Chile.

  11. Simultaneous message framing and error detection

    NASA Technical Reports Server (NTRS)

    Frey, A. H., Jr.

    1968-01-01

    Circuitry simultaneously inserts message framing information and detects noise errors in binary code data transmissions. Separate message groups are framed without requiring both framing bits and error-checking bits, and predetermined message sequence are separated from other message sequences without being hampered by intervening noise.

  12. Simultaneous onset of ferromagnetism and superconductivity.

    PubMed

    Suhl, H

    2001-10-15

    In a few compounds, magnetic ordering and superconductivity appear to arise at the same value of a critical parameter. Assuming a model of magnetic ordering based on localized spins, this simultaneous onset may be explained as a coupling of two conduction electrons via one localized spin. This is analogous to magnetic order arising from coupling of two localized spins via one conduction electron.

  13. Simultaneous Translation: Idiom Interpretation and Parsing Heuristics.

    ERIC Educational Resources Information Center

    McDonald, Janet L.; Carpenter, Patricia A.

    1981-01-01

    Presents a model of interpretation, parsing and error recovery in simultaneous translation using two experts and two amateur German-English bilingual translators orally translating from English to German. Argues that the translator first comprehends the text in English and divides it into meaningful units before translating. Study also…

  14. Problems of Simultaneous Interpreting of Scientific Discussion.

    ERIC Educational Resources Information Center

    Chachibaia, Nelly

    This article focuses on the problems of simultaneous translation (SI) of scientific discussion at the Conference on Training Translators and Interpreters in the New Millennium, the development of which greatly depends on extralinguistic, external conference conditions. Text linguistics considers text not only as a grammatical unit larger than a…

  15. Baseline estimation from simultaneous satellite laser tracking

    NASA Technical Reports Server (NTRS)

    Dedes, George C.

    1987-01-01

    Simultaneous Range Differences (SRDs) to Lageos are obtained by dividing the observing stations into pairs with quasi-simultaneous observations. For each of those pairs the station with the least number of observations is identified, and at its observing epochs interpolated ranges for the alternate station are generated. The SRD observables are obtained by subtracting the actually observed laser range of the station having the least number of observations from the interpolated ranges of the alternate station. On the basis of these observables semidynamic single baseline solutions were performed. The aim of these solutions is to further develop and implement the SRD method in the real data environment, to assess its accuracy, its advantages and disadvantages as related to the range dynamic mode methods, when the baselines are the only parameters of interest. Baselines, using simultaneous laser range observations to Lageos, were also estimated through the purely geometric method. These baselines formed the standards the standards of comparison in the accuracy assessment of the SRD method when compared to that of the range dynamic mode methods. On the basis of this comparison it was concluded that for baselines of regional extent the SRD method is very effective, efficient, and at least as accurate as the range dynamic mode methods, and that on the basis of a simple orbital modeling and a limited orbit adjustment. The SRD method is insensitive to the inconsistencies affecting the terrestrial reference frame and simultaneous adjustment of the Earth Rotation Parameters (ERPs) is not necessary.

  16. Simultaneous Prompting: A Review of the Literature

    ERIC Educational Resources Information Center

    Morse, Timothy E.; Schuster, John W.

    2004-01-01

    Published literature pertaining to the simultaneous prompting teaching procedure is reviewed. Purposes of this review are to (a) present an initial analysis of effectiveness of this emerging response prompting procedure, (b) discuss work that has been conducted to date, and (c) provide directions for future research. Data from all published…

  17. Simultaneous Visual Discrimination in Asian Elephants

    ERIC Educational Resources Information Center

    Nissani, Moti; Hoefler-Nissani, Donna; Lay, U. Tin; Htun, U. Wan

    2005-01-01

    Two experiments explored the behavior of 20 Asian elephants ("Elephas aximus") in simultaneous visual discrimination tasks. In Experiment 1, 7 Burmese logging elephants acquired a white+/black- discrimination, reaching criterion in a mean of 2.6 sessions and 117 discrete trials, whereas 4 elephants acquired a black+/white- discrimination in 5.3…

  18. Simultaneous-Frequency Nonlinear Radar: Hardware Simulation

    DTIC Science & Technology

    2015-08-01

    Army Research Laboratory Simultaneous-Frequency Nonlinear Radar : Hardware Simulation by Gregory J Mazzaro, Kenneth I Ranney, Kyle A Gallagher...distribution unlimited. NOTICES Disclaimers The findings in this report are not to be construed as an official Department of the Army position

  19. Simultaneous Renewal through Professional Development School Partnerships

    ERIC Educational Resources Information Center

    Shroyer, Gail; Yahnke, Sally; Bennett, Andrew; Dunn, Cindi

    2007-01-01

    The authors describe the premises, processes used, and outcomes of a K-16 simultaneous renewal model, as implemented through the Kansas State University Professional Development School Partnership Project. The goal of this partnership is to improve K-12 teaching and learning while improving a university teacher-preparation program through…

  20. Preventing Simultaneous Conduction In Switching Transistors

    NASA Technical Reports Server (NTRS)

    Mclyman, William T.

    1990-01-01

    High voltage spikes and electromagnetic interference suppressed. Power-supply circuit including two switching transistors easily modified to prevent simultaneous conduction by both transistors during switching intervals. Diode connected between collector of each transistor and driving circuit for opposite transistor suppresses driving signal to transistor being turned on until transistor being turned off ceases to carry current.

  1. Multisensory integration is independent of perceived simultaneity.

    PubMed

    Harrar, Vanessa; Harris, Laurence R; Spence, Charles

    2017-03-01

    The importance of multisensory integration for perception and action has long been recognised. Integrating information from individual senses increases the chance of survival by reducing the variability in the incoming signals, thus allowing us to respond more rapidly. Reaction times (RTs) are fastest when the components of the multisensory signals are simultaneous. This response facilitation is traditionally attributed to multisensory integration. However, it is unclear if facilitation of RTs occurs when stimuli are perceived as synchronous or are actually physically synchronous. Repeated exposure to audiovisual asynchrony can change the delay at which multisensory stimuli are perceived as simultaneous, thus changing the delay at which the stimuli are integrated-perceptually. Here we set out to determine how such changes in multisensory integration for perception affect our ability to respond to multisensory events. If stimuli perceived as simultaneous were reacted to most rapidly, it would suggest a common system for multisensory integration for perception and action. If not, it would suggest separate systems. We measured RTs to auditory, visual, and audiovisual stimuli following exposure to audiovisual asynchrony. Exposure affected the variability of the unisensory RT distributions; in particular, the slowest RTs were either speed up or slowed down (in the direction predicted from shifts in perceived simultaneity). Additionally, the multisensory facilitation of RTs (beyond statistical summation) only occurred when audiovisual onsets were physically synchronous, rather than when they appeared simultaneous. We conclude that the perception of synchrony is therefore independent of multisensory integration and suggest a division between multisensory processes that are fast (automatic and unaffected by temporal adaptation) and those that are slow (perceptually driven and adaptable).

  2. Emission Spectroscopy measurement of hybrid ECR-Helicon plasma source parameters

    NASA Astrophysics Data System (ADS)

    Hala, Ahmed

    2015-09-01

    Optical emission spectroscopy measurement of plasma temperature and density were conducted on KACST hybrid plasma source. The hybrid source involves ECR and helicon source operated simultanously. The results indicate that the ECR alone density is higher than the density of the combined sources while the combined temperature is lower.

  3. Resonance Raman spectroscopy.

    PubMed

    Robert, Bruno

    2009-01-01

    Resonance Raman spectroscopy may yield precise information on the conformation of, and on the interactions assumed by, the chromophores involved in the first steps of the photosynthetic process, whether isolated in solvents, embedded in soluble or membrane proteins, or, as shown recently, in vivo. By making use of this technique, it is possible, for instance, to relate the electronic properties of these molecules to their structure and/or the physical properties of their environment, or to determine subtle changes of their conformation associated with regulatory processes. After a short introduction to the physical principles that govern resonance Raman spectroscopy, the information content of resonance Raman spectra of chlorophyll and carotenoid molecules is described in this review, together with the experiments which helped in determining which structural parameter each Raman band is sensitive to. A selection of applications of this technique is then presented, in order to give a fair and precise idea of which type of information can be obtained from its use in the field of photosynthesis.

  4. Nanowire Electron Scattering Spectroscopy

    NASA Technical Reports Server (NTRS)

    Hunt, Brian; Bronikowsky, Michael; Wong, Eric; VonAllmen, Paul; Oyafuso, Fablano

    2009-01-01

    Nanowire electron scattering spectroscopy (NESS) has been proposed as the basis of a class of ultra-small, ultralow-power sensors that could be used to detect and identify chemical compounds present in extremely small quantities. State-of-the-art nanowire chemical sensors have already been demonstrated to be capable of detecting a variety of compounds in femtomolar quantities. However, to date, chemically specific sensing of molecules using these sensors has required the use of chemically functionalized nanowires with receptors tailored to individual molecules of interest. While potentially effective, this functionalization requires labor-intensive treatment of many nanowires to sense a broad spectrum of molecules. In contrast, NESS would eliminate the need for chemical functionalization of nanowires and would enable the use of the same sensor to detect and identify multiple compounds. NESS is analogous to Raman spectroscopy, the main difference being that in NESS, one would utilize inelastic scattering of electrons instead of photons to determine molecular vibrational energy levels. More specifically, in NESS, one would exploit inelastic scattering of electrons by low-lying vibrational quantum states of molecules attached to a nanowire or nanotube.

  5. Vibronic Spectroscopy of Phenylvinylnitrile

    NASA Astrophysics Data System (ADS)

    Mehta, Deepali N.; Navotnaya, Polina; Parobek, Alex; Clayton, Rachel; Vara, Vanesa Vaquero; Zwier, Timothy S.

    2012-06-01

    This talk will present results of a gas phase, jet-cooled vibronic spectroscopy study of phenylvinylnitrile (C_6H_5-CH=CH-C≡N, PVN). This molecule is seen as a potential photochemical precursor to nitrogen heteroaromatics, and therefore is particularly relevant to Titan's atmosphere, where nitriles exist in significant abundance. As a first step towards such photochemical studies, a fluorescence excitation spectrum of PVN spanning the range 33,500-35,840 cm- 1 (298.5-279.0 nm) has been recorded, and dispersed fluorescence spectra that uncover and characterize the vibronic activity have been acquired. The S_0-S_1 origin is a prominent band located at 33,826 cm- 1, and the excitation spectrum is characterized by significant vibronic activity leading to spectral congestion. Hole-burning in the region of 33,500-35,840 cm- 1 has also been completed, and the excitation spectrum can be assigned solely to (E)-PVN. As PVN is the nitrogen-containing counterpart to phenylvinylacetylene (PVA), a comparison of the vibronic spectroscopy between the two molecules will be made.

  6. Photothermal spectroscopy of aerosols

    SciTech Connect

    Campillo, A.J.; Lin, H.B.

    1981-04-01

    In situ aerosol absorption spectroscopy was performed using two novel photothermal detection schemes. The first, based on a photorefractive effect and coherent detection, called phase fluctuation optical heterodyne (PFLOH) spectroscopy, could, depending on the geometry employed, yield particle specific or particle and gas absorption data. Single particles of graphite as small as 1 ..mu..m were detected in the particle specific mode. In another geometrical configuration, the total absorption (both gas and particle) of submicron sized aerosols of ammonium sulfate particles in equilibrium with gaseous ammonia and water vapor were measured at varying CO/sub 2/ laser frequencies. The specific absorption coefficient for the sulfate ion was measured to be 0.5 m/sup 2//g at 1087 cm/sup -1/. The absorption coefficient sensitivity of this scheme was less than or equal to 10/sup -8/ cm/sup -1/. The second scheme is a hybrid visible Mie scattering scheme incorporating photothermal modulation. Particle specific data on ammonium sulfate droplets were obtained. For chemically identical species, the relative absorption spectrum versus laser frequency can be obtained for polydisperse aerosol distributions directly from the data without the need for complex inverse scattering calculations.

  7. Atmospheric trace molecule spectroscopy

    NASA Technical Reports Server (NTRS)

    Farmer, C. B.

    1982-01-01

    The Spacelab investigation entitled Atmospheric Trace Molecule Spectroscopy (ATMOS) is designed to obtain fundamental information related to the chemistry and physics of the Earth's upper atmosphere using the techniques of infrared absorption spectroscopy. There are two principal objectives to be met. The first is the determination, on a global scale, of the compositional structure of the upper atmosphere and its spatial variability. The establishment of this variability represents the first step toward determining the characteristic residence times for the upper atmospheric constituents; the magnitudes of their sources and sinks; and, ultimately, an understanding of their effects on the stability of the stratosphere. The second objective is to provide the high-resolution, calibrated spectral information which is essential for the detailed design of advanced instrumentation for subsequent global monitoring of specific species found to be critical to atmospheric stability. This information will be disseminated in the form of a three dimensional atlas of solar absorption spectra obtained over a range of latitudes, longitudes, and altitudes.

  8. Wave mixing spectroscopy

    SciTech Connect

    Smith, R.W.

    1980-08-01

    Several new aspects of nonlinear or wave mixing spectroscopy were investigated utilizing the polarization properties of the nonlinear output field and the dependence of this field upon the occurrence of multiple resonances in the nonlinear susceptibility. First, it is shown theoretically that polarization-sensitive detection may be used to either eliminate or controllably reduce the nonresonant background in coherent anti-Stokes Raman spectroscopy, allowing weaker Raman resonances to be studied. The features of multi-resonant four-wave mixing are examined in the case of an inhomogeneously broadened medium. It is found that the linewidth of the nonlinear output narrows considerably (approaching the homogeneous width) when the quantum mechanical expressions for the doubly- and triply-resonant susceptibilities are averaged over a Doppler or strain broadened profile. Experimental studies of nonlinear processes in Pr/sup +3/:LaF/sub 3/ verify this linewidth narrowing, but indicate that this strain broadened system cannot be treated with a single broadening parameter as in the case of Doppler broadening in a gas. Several susceptibilities are measured from which are deduced dipole matrix elements and Raman polarizabilities related to the /sup 3/H/sub 4/, /sup 3/H/sub 6/, and /sup 3/P/sub 0/ levels of the praseodymium ions.

  9. Octa-BODIPY derivative dendrimeric cyclotetraphosphazenes; photophysical properties and fluorescent chemosensor for Co2 + ions

    NASA Astrophysics Data System (ADS)

    Şenkuytu, Elif; Eçik, Esra Tanrıverdi

    2017-02-01

    We have designed and synthesized the first examples of fluorescent chemosensors based on octa-BODIPY decorated dendrimeric cyclotetraphosphazenes. The structures these synthesized compounds were verified by 1H, 13C, 31P NMR spectroscopies and UV-vis electronic absorption spectra. The photophysical and metal sensing properties in THF solutions of dendrimeric cyclotetraphosphazenes (OBCP 1-3) were investigated by fluorescence spectroscopy. OBCP 1-3 showed strong absorption in the 500-640 nm region with high molar extinction coefficients. Additionally, octa-BODIPY decorated dendrimeric cyclotetraphosphazenes are candidate for fluorescent chemosensor for Co2 + showing high selectivity with a low limit of detection.

  10. Transcendental and interpolation methods in simultaneous stabilization and simultaneous partial pole placement problems

    NASA Technical Reports Server (NTRS)

    Ghosh, B. K.

    1986-01-01

    The existence of a compensator which simultaneously renders a given r-tuple of multiinput-multioutput p x m linear dynamical systems internally stable is investigated. In particular, a set of simultaneously stabilizable r-tuples of plants is parametrized, and it is shown that, provided r = max(m,p) or less, the above set is semialgebraic and dense in the space Sigma of r-tuples of plants. An extension of the classical pole placement and stabilization problems is considered, and the simultaneous partial pole placement problem is investigated.

  11. Photoelectron photoion molecular beam spectroscopy

    SciTech Connect

    Trevor, D.J.

    1980-12-01

    The use of supersonic molecular beams in photoionization mass spectroscopy and photoelectron spectroscopy to assist in the understanding of photoexcitation in the vacuum ultraviolet is described. Rotational relaxation and condensation due to supersonic expansion were shown to offer new possibilities for molecular photoionization studies. Molecular beam photoionization mass spectroscopy has been extended above 21 eV photon energy by the use of Stanford Synchrotron Radiation Laboratory (SSRL) facilities. Design considerations are discussed that have advanced the state-of-the-art in high resolution vuv photoelectron spectroscopy. To extend gas-phase studies to 160 eV photon energy, a windowless vuv-xuv beam line design is proposed.

  12. Simultaneous formation of solar system giant planets

    NASA Astrophysics Data System (ADS)

    Guilera, O. M.; Fortier, A.; Brunini, A.; Benvenuto, O. G.

    2011-08-01

    Context. In the last few years, the so-called "Nice model" has become increasingly significant for studying the formation and evolution of the solar system. According to this model, the initial orbital configuration of the giant planets was much more compact than the one we observe today. Aims: We study the formation of the giant planets in connection with several parameters that describe the protoplanetary disk. We aim to establish which conditions enable their simultaneous formation in line with the initial configuration proposed by the Nice model. We focus on the conditions that lead to the simultaneous formation of two massive cores, corresponding to Jupiter and Saturn, which are able to reach the cross-over mass (where the mass of the envelope of the giant planet equals the mass of the core, and gaseous runway starts), while two other cores that correspond to Uranus and Neptune have to be able to grow to their current masses. Methods: We compute the in situ planetary formation, employing the numerical code introduced in our previous work for different density profiles of the protoplanetary disk. Planetesimal migration is taken into account and planetesimals are considered to follow a size distribution between r_pmin (free parameter) and r_pmax= 100 km. The core's growth is computed according to the oligarchic growth regime. Results: The simultaneous formation of the giant planets was successfully completed for several initial conditions of the disk. We find that for protoplanetary disks characterized by a power law (Σ ∝ r - p), flat surface density profiles (p ≤ 1.5) favor the simultaneous formation. However, for steep slopes (p 2, as previously proposed by other authors) the simultaneous formation of the solar system giant planets is unlikely. Conclusions: The simultaneous formation of the giant planets - in the context of the Nice model - is favored by flat surface density profiles. The formation time-scale agrees with the estimates of disk lifetimes if

  13. Understanding catalyst behavior during in situ heating through simultaneous secondary and transmitted electron imaging

    NASA Astrophysics Data System (ADS)

    Howe, Jane Y.; Allard, Lawrence F.; Bigelow, Wilbur C.; Demers, Hendrix; Overbury, Steven H.

    2014-11-01

    By coupling techniques of simultaneous secondary (SE) and transmitted electron (TE) imaging at high resolution in a modern scanning transmission electron microscope (STEM), with the ability to heat specimens using a highly stable MEMS-based heating platform, we obtained synergistic information to clarify the behavior of catalysts during in situ thermal treatments. Au/iron oxide catalyst 'leached' to remove surface Au was heated to temperatures as high as 700°C. The Fe2O3 support particle structure tended to reduce to Fe3O4 and formed surface terraces; the formation, coalescence, and mobility of 1- to 2-nm particles on the terraces were characterized in SE, STEM-ADF, and TEM-BF modes. If combined with simultaneous nanoprobe spectroscopy, this approach will open the door to a new way of studying the kinetics of nano-scaled phenomena.

  14. Quantitative Comparison of Tumor Delivery for Multiple Targeted Nanoparticles Simultaneously by Multiplex ICP-MS

    PubMed Central

    Elias, Andrew; Crayton, Samuel H.; Warden-Rothman, Robert; Tsourkas, Andrew

    2014-01-01

    Given the rapidly expanding library of disease biomarkers and targeting agents, the number of unique targeted nanoparticles is growing exponentially. The high variability and expense of animal testing often makes it unfeasible to examine this large number of nanoparticles in vivo. This often leads to the investigation of a single formulation that performed best in vitro. However, nanoparticle performance in vivo depends on many variables, many of which cannot be adequately assessed with cell-based assays. To address this issue, we developed a lanthanide-doped nanoparticle method that allows quantitative comparison of multiple targeted nanoparticles simultaneously. Specifically, superparamagnetic iron oxide (SPIO) nanoparticles with different targeting ligands were created, each with a unique lanthanide dopant. Following the simultaneous injection of the various SPIO compositions into tumor-bearing mice, inductively coupled plasma mass spectroscopy was used to quantitatively and orthogonally assess the concentration of each SPIO composition in serial blood and resected tumor samples. PMID:25068300

  15. Quantitative Comparison of Tumor Delivery for Multiple Targeted Nanoparticles Simultaneously by Multiplex ICP-MS

    NASA Astrophysics Data System (ADS)

    Elias, Andrew; Crayton, Samuel H.; Warden-Rothman, Robert; Tsourkas, Andrew

    2014-07-01

    Given the rapidly expanding library of disease biomarkers and targeting agents, the number of unique targeted nanoparticles is growing exponentially. The high variability and expense of animal testing often makes it unfeasible to examine this large number of nanoparticles in vivo. This often leads to the investigation of a single formulation that performed best in vitro. However, nanoparticle performance in vivo depends on many variables, many of which cannot be adequately assessed with cell-based assays. To address this issue, we developed a lanthanide-doped nanoparticle method that allows quantitative comparison of multiple targeted nanoparticles simultaneously. Specifically, superparamagnetic iron oxide (SPIO) nanoparticles with different targeting ligands were created, each with a unique lanthanide dopant. Following the simultaneous injection of the various SPIO compositions into tumor-bearing mice, inductively coupled plasma mass spectroscopy was used to quantitatively and orthogonally assess the concentration of each SPIO composition in serial blood and resected tumor samples.

  16. Note: Time-gated 3D single quantum dot tracking with simultaneous spinning disk imaging

    SciTech Connect

    DeVore, M. S.; Stich, D. G.; Keller, A. M.; Phipps, M. E.; Hollingsworth, J. A.; Goodwin, P. M.; Werner, J. H.; Cleyrat, C.; Lidke, D. S.; Wilson, B. S.

    2015-12-15

    We describe recent upgrades to a 3D tracking microscope to include simultaneous Nipkow spinning disk imaging and time-gated single-particle tracking (SPT). Simultaneous 3D molecular tracking and spinning disk imaging enable the visualization of cellular structures and proteins around a given fluorescently labeled target molecule. The addition of photon time-gating to the SPT hardware improves signal to noise by discriminating against Raman scattering and short-lived fluorescence. In contrast to camera-based SPT, single-photon arrival times are recorded, enabling time-resolved spectroscopy (e.g., measurement of fluorescence lifetimes and photon correlations) to be performed during single molecule/particle tracking experiments.

  17. [A method of obtaining vibrational dephasing time of molecular multi-vibrational modes simultaneously].

    PubMed

    Wan, Hui; Yin, Jun; Yu, Ling-Yao; Liu, Xing; Qu, Jun-Le; Lin, Zi-Yang; Niu, Han-Ben

    2011-02-01

    In the present paper, the authors used the time-resolved coherent anti-Stokes Raman scattering (CARS) spectroscopy based on supercontinuum developed by ourselves to acquire simultaneously the molecular vibration spectrum and vibrational dephasing time of the molecular various vibrational modes. Using benzonitrile as the sample, the authors measured its vibrational relaxation processes at its five typical vibrational modes and obtained their vibrational dephasing time respectively. In the experiment, the authors also found the phenomenon that oscillations appear in the vibrational dephasing of plane bending vibration mode of benzene ring in benzonitrile, which was caused by superposition of the two adjacent normal vibrational modes excited simultaneously. After mixing benzonitrile with anhydrous ethanol, the authors also measured their vibrational dephasing time. This method is capable of monitoring the changes of the molecular characteristics and its micro-environment, therefore it will find widespread applications in biology, chemistry and materials science.

  18. Chemically modified Si(111) surfaces simultaneously demonstrating hydrophilicity, resistance against oxidation, and low trap state densities

    NASA Astrophysics Data System (ADS)

    Brown, Elizabeth S.; Hlynchuk, Sofiya; Maldonado, Stephen

    2016-03-01

    Chemically modified Si(111) surfaces have been prepared through a series of wet chemical surface treatments that simultaneously show resistance towards surface oxidation, selective reactivity towards chemical reagents, and areal defect densities comparable to unannealed thermal oxides. Specifically, grazing angle attenuated total reflectance infrared and X-ray photoelectron (XP) spectroscopies were used to characterize allyl-, 3,4-methylenedioxybenzene-, or 4-[bis(trimethylsilyl)amino]phenyl-terminated surfaces and the subsequently hydroxylated surfaces. Hydroxylated surfaces were confirmed through reaction with 4-(trifluoromethyl)benzyl bromide and quantified by XP spectroscopy. Contact angle measurements indicated all surfaces remained hydrophilic, even after secondary backfilling with CH3sbnd groups. Surface recombination velocity measurements by way of microwave photoconductivity transients showed the relative defect-character of as-prepared and aged surfaces. The relative merits for each investigated surface type are discussed.

  19. Large-scale Growth and Simultaneous Doping of Molybdenum Disulfide Nanosheets

    NASA Astrophysics Data System (ADS)

    Kim, Seong Jun; Kang, Min-A.; Kim, Sung Ho; Lee, Youngbum; Song, Wooseok; Myung, Sung; Lee, Sun Sook; Lim, Jongsun; An, Ki-Seok

    2016-04-01

    A facile method that uses chemical vapor deposition (CVD) for the simultaneous growth and doping of large-scale molybdenum disulfide (MoS2) nanosheets was developed. We employed metalloporphyrin as a seeding promoter layer for the uniform growth of MoS2 nanosheets. Here, a hybrid deposition system that combines thermal evaporation and atomic layer deposition (ALD) was utilized to prepare the promoter. The doping effect of the promoter was verified by X-ray photoelectron spectroscopy and Raman spectroscopy. In addition, the carrier density of the MoS2 nanosheets was manipulated by adjusting the thickness of the metalloporphyrin promoter layers, which allowed the electrical conductivity in MoS2 to be manipulated.

  20. Large-scale Growth and Simultaneous Doping of Molybdenum Disulfide Nanosheets

    PubMed Central

    Kim, Seong Jun; Kang, Min-A; Kim, Sung Ho; Lee, Youngbum; Song, Wooseok; Myung, Sung; Lee, Sun Sook; Lim, Jongsun; An, Ki-Seok

    2016-01-01

    A facile method that uses chemical vapor deposition (CVD) for the simultaneous growth and doping of large-scale molybdenum disulfide (MoS2) nanosheets was developed. We employed metalloporphyrin as a seeding promoter layer for the uniform growth of MoS2 nanosheets. Here, a hybrid deposition system that combines thermal evaporation and atomic layer deposition (ALD) was utilized to prepare the promoter. The doping effect of the promoter was verified by X-ray photoelectron spectroscopy and Raman spectroscopy. In addition, the carrier density of the MoS2 nanosheets was manipulated by adjusting the thickness of the metalloporphyrin promoter layers, which allowed the electrical conductivity in MoS2 to be manipulated. PMID:27044862

  1. Resonant ultrasound spectroscopy

    DOEpatents

    Migliori, Albert

    1991-01-01

    A resonant ultrasound spectroscopy method provides a unique characterization of an object for use in distinguishing similar objects having physical differences greater than a predetermined tolerance. A resonant response spectrum is obtained for a reference object by placing excitation and detection transducers at any accessible location on the object. The spectrum is analyzed to determine the number of resonant response peaks in a predetermined frequency interval. The distribution of the resonance frequencies is then characterized in a manner effective to form a unique signature of the object. In one characterization, a small frequency interval is defined and stepped though the spectrum frequency range. Subsequent objects are similarly characterized where the characterizations serve as signatures effective to distinguish objects that differ from the reference object by more than the predetermined tolerance.

  2. Soliton absorption spectroscopy

    PubMed Central

    Kalashnikov, V. L.; Sorokin, E.

    2010-01-01

    We analyze optical soliton propagation in the presence of weak absorption lines with much narrower linewidths as compared to the soliton spectrum width using the novel perturbation analysis technique based on an integral representation in the spectral domain. The stable soliton acquires spectral modulation that follows the associated index of refraction of the absorber. The model can be applied to ordinary soliton propagation and to an absorber inside a passively modelocked laser. In the latter case, a comparison with water vapor absorption in a femtosecond Cr:ZnSe laser yields a very good agreement with experiment. Compared to the conventional absorption measurement in a cell of the same length, the signal is increased by an order of magnitude. The obtained analytical expressions allow further improving of the sensitivity and spectroscopic accuracy making the soliton absorption spectroscopy a promising novel measurement technique. PMID:21151755

  3. Broadband local dielectric spectroscopy

    NASA Astrophysics Data System (ADS)

    Labardi, M.; Lucchesi, M.; Prevosto, D.; Capaccioli, S.

    2016-05-01

    A route to extend the measurement bandwidth of local dielectric spectroscopy up to the MHz range has been devised. The method is based on a slow amplitude modulation at a frequency Ω of the excitation field oscillating at a frequency ω and the coherent detection of the modulated average electric force or force gradient at Ω. The cantilever mechanical response does not affect the measurement if Ω is well below its resonant frequency; therefore, limitations on the excitation field frequency are strongly reduced. Demonstration on a thin poly(vinyl acetate) film is provided, showing its structural relaxation spectrum on the local scale up to 45 °C higher than glass temperature, and nanoscale resolution dielectric relaxation imaging near conductive nanowires embedded in the polymer matrix was obtained up to 5 MHz frequency, with no physical reason to hinder further bandwidth extension.

  4. Femtosecond Stimulated Raman Spectroscopy.

    PubMed

    Dietze, Daniel R; Mathies, Richard A

    2016-05-04

    Femtosecond stimulated Raman spectroscopy (FSRS) is an ultrafast nonlinear optical technique that provides vibrational structural information with high temporal (sub-50 fs) precision and high spectral (10 cm(-1) ) resolution. Since the first full demonstration of its capabilities ≈15 years ago, FSRS has evolved into a mature technique, giving deep insights into chemical and biochemical reaction dynamics that would be inaccessible with any other technique. It is now being routinely applied to virtually all possible photochemical reactions and systems spanning from single molecules in solution to thin films, bulk crystals and macromolecular proteins. This review starts with an historic overview and discusses the theoretical and experimental concepts behind this technology. Emphasis is put on the current state-of-the-art experimental realization and several variations of FSRS that have been developed. The unique capabilities of FSRS are illustrated through a comprehensive presentation of experiments to date followed by prospects.

  5. Computational multiheterodyne spectroscopy

    PubMed Central

    Burghoff, David; Yang, Yang; Hu, Qing

    2016-01-01

    Dual-comb spectroscopy allows for high-resolution spectra to be measured over broad bandwidths, but an essential requirement for coherent integration is the availability of a phase reference. Usually, this means that the combs’ phase and timing errors must be measured and either minimized by stabilization or removed by correction, limiting the technique’s applicability. We demonstrate that it is possible to extract the phase and timing signals of a multiheterodyne spectrum completely computationally, without any extra measurements or optical elements. These techniques are viable even when the relative linewidth exceeds the repetition rate difference and can tremendously simplify any dual-comb system. By reconceptualizing frequency combs in terms of the temporal structure of their phase noise, not their frequency stability, we can greatly expand the scope of multiheterodyne techniques. PMID:27847870

  6. Protected subspace Ramsey spectroscopy

    NASA Astrophysics Data System (ADS)

    Ostermann, L.; Plankensteiner, D.; Ritsch, H.; Genes, C.

    2014-11-01

    We study a modified Ramsey spectroscopy technique employing slowly decaying states for quantum metrology applications using dense ensembles. While closely positioned atoms exhibit super-radiant collective decay and dipole-dipole induced frequency shifts, recent results [L. Ostermann, H. Ritsch, and C. Genes, Phys. Rev. Lett. 111, 123601 (2013), 10.1103/PhysRevLett.111.123601] suggest the possibility to suppress such detrimental effects and achieve an even better scaling of the frequency sensitivity with interrogation time than for noninteracting particles. Here we present an in-depth analysis of this "protected subspace Ramsey technique" using improved analytical modeling and numerical simulations including larger three-dimensional (3D) samples. Surprisingly we find that using subradiant states of N particles to encode the atomic coherence yields a scaling of the optimal sensitivity better than 1 /√{N } . Applied to ultracold atoms in 3D optical lattices we predict a precision beyond the single atom linewidth.

  7. Tool For Driving Many Fasteners Simultaneously

    NASA Technical Reports Server (NTRS)

    Cook, Joseph S., Jr.

    1995-01-01

    Proposed tool tightens or loosens several bolts, screws, nuts, or other threaded fasteners arranged in circle on compressor head, automotive wheel, pipe-end flange, or similar object. Enables assembly or disassembly in fraction of time needed to tighten fasteners one at a time. Simultaneously applies same torque to all fasteners, preventing distortion and enhancing reliability. Concept not limited to circular fastener patterns. Adapted to rectangular configurations like on engine intake manifolds, by adding gears to drive train to provide proper spacing. Designed to deliver fixed or adjustable maximum torque. To ensure even seal loading, piston pressure simultaneously ramped from initial to final values to maintain relatively constant torque loading on all fasteners until final specifications limit achieved.

  8. Bilateral inguinal hernias: simultaneous or sequential repair?

    PubMed Central

    Stott, M. A.; Sutton, R.; Royle, G. T.

    1988-01-01

    Two hundred and forty four patients underwent either simultaneous bilateral inguinal hernia repair (n = 122) or unilateral inguinal hernia (n = 122) repair at a general hospital between January 1971 and December 1981. The two groups of patients were matched for age and sex. Both groups had a similar overall incidence of post-operative complications and in both groups the duration of post-operative stay and duration of operating time were similar. Chest infections developed in 12 patients after bilateral repair and in 3 patients after unilateral repair (P less than 0.02). All patients were assessed prospectively from 4 to 15 years after operation, when no significant difference in the number of recurrent hernias was found. Our results suggest that simultaneous bilateral inguinal herniorrhaphy is economical in terms of both operating time and duration of hospital stay, and that this economy is not bought at a cost of increased short term morbidity or long-term recurrence rate. PMID:3200778

  9. Simultaneous CARS and Interferometric Rayleigh Scattering

    NASA Technical Reports Server (NTRS)

    Bivolaru, Daniel; Danehy, Paul M.; Grinstead, Keith D., Jr.; Tedder, Sarah; Cutler, Andrew D.

    2006-01-01

    This paper reports for the first time the combination of a dual-pump coherent anti-Stokes Raman scattering system with an interferometric Rayleigh scattering system (CARS - IRS) to provide time-resolved simultaneous measurement of multiple properties in combustion flows. The system uses spectrally narrow green (seeded Nd:YAG at 532 nm) and yellow (552.9 nm) pump beams and a spectrally-broad red (607 nm) beam as the Stokes beam. A spectrometer and a planar Fabry-Perot interferometer used in the imaging mode are used to record the spectrally broad CARS spectra and the spontaneous Rayleigh scattering spectra, respectively. Time-resolved simultaneous measurement of temperature, absolute mole fractions of N2, O2, and H2, and two components of velocity in a Hencken burner flame were performed to demonstrate the technique.

  10. Simultaneous nano-tracking of multiple motor proteins via spectral discrimination of quantum dots

    PubMed Central

    Kakizuka, Taishi; Ikezaki, Keigo; Kaneshiro, Junichi; Fujita, Hideaki; Watanabe, Tomonobu M.; Ichimura, Taro

    2016-01-01

    Simultaneous nanometric tracking of multiple motor proteins was achieved by combining multicolor fluorescent labeling of target proteins and imaging spectroscopy, revealing dynamic behaviors of multiple motor proteins at the sub-diffraction-limit scale. Using quantum dot probes of distinct colors, we experimentally verified the localization precision to be a few nanometers at temporal resolution of 30 ms or faster. One-dimensional processive movement of two heads of a single myosin molecule and multiple myosin molecules was successfully traced. Furthermore, the system was modified for two-dimensional measurement and applied to tracking of multiple myosin molecules. Our approach is useful for investigating cooperative movement of proteins in supramolecular nanomachinery. PMID:27446684

  11. Simultaneous Temperature and Velocity Measurements in a Large-Scale, Supersonic, Heated Jet

    NASA Technical Reports Server (NTRS)

    Danehy, P. M.; Magnotti, G.; Bivolaru, D.; Tedder, S.; Cutler, A. D.

    2008-01-01

    Two laser-based measurement techniques have been used to characterize an axisymmetric, combustion-heated supersonic jet issuing into static room air. The dual-pump coherent anti-Stokes Raman spectroscopy (CARS) measurement technique measured temperature and concentration while the interferometric Rayleigh scattering (IRS) method simultaneously measured two components of velocity. This paper reports a preliminary analysis of CARS-IRS temperature and velocity measurements from selected measurement locations. The temperature measurements show that the temperature along the jet axis remains constant while dropping off radially. The velocity measurements show that the nozzle exit velocity fluctuations are about 3% of the maximum velocity in the flow.

  12. Electron spectroscopy analysis

    NASA Technical Reports Server (NTRS)

    Gregory, John C.

    1992-01-01

    The Surface Science Laboratories at the University of Alabama in Huntsville (UAH) are equipped with x-ray photoelectron spectroscopy (XPS or ESCA) and Auger electron spectroscopy (AES) facilities. These techniques provide information from the uppermost atomic layers of a sample, and are thus truly surface sensitive. XPS provides both elemental and chemical state information without restriction on the type of material that can be analyzed. The sample is placed into an ultra high vacuum (UHV) chamber and irradiated with x-rays which cause the ejection of photoelectrons from the sample surface. Since x-rays do not normally cause charging problems or beam damage, XPS is applicable to a wide range of samples including metals, polymers, catalysts, and fibers. AES uses a beam of high energy electrons as a surface probe. Following electronic rearrangements within excited atoms by this probe, Auger electrons characteristic of each element present are emitted from the sample. The main advantage of electron induced AES is that the electron beam can be focused down to a small diameter and localized analysis can be carried out. On the rastering of this beam synchronously with a video display using established scanning electron microscopy techniques, physical images and chemical distribution maps of the surface can be produced. Thus very small features, such as electronic circuit elements or corrosion pits in metals, can be investigated. Facilities are available on both XPS and AES instruments for depth-profiling of materials, using a beam of argon ions to sputter away consecutive layers of material to reveal sub-surface (and even semi-bulk) analyses.

  13. Simultaneous statistical inference for epigenetic data.

    PubMed

    Schildknecht, Konstantin; Olek, Sven; Dickhaus, Thorsten

    2015-01-01

    Epigenetic research leads to complex data structures. Since parametric model assumptions for the distribution of epigenetic data are hard to verify we introduce in the present work a nonparametric statistical framework for two-group comparisons. Furthermore, epigenetic analyses are often performed at various genetic loci simultaneously. Hence, in order to be able to draw valid conclusions for specific loci, an appropriate multiple testing correction is necessary. Finally, with technologies available for the simultaneous assessment of many interrelated biological parameters (such as gene arrays), statistical approaches also need to deal with a possibly unknown dependency structure in the data. Our statistical approach to the nonparametric comparison of two samples with independent multivariate observables is based on recently developed multivariate multiple permutation tests. We adapt their theory in order to cope with families of hypotheses regarding relative effects. Our results indicate that the multivariate multiple permutation test keeps the pre-assigned type I error level for the global null hypothesis. In combination with the closure principle, the family-wise error rate for the simultaneous test of the corresponding locus/parameter-specific null hypotheses can be controlled. In applications we demonstrate that group differences in epigenetic data can be detected reliably with our methodology.

  14. Simultaneous face and voice processing in schizophrenia.

    PubMed

    Liu, Taosheng; Pinheiro, Ana P; Zhao, Zhongxin; Nestor, Paul G; McCarley, Robert W; Niznikiewicz, Margaret

    2016-05-15

    While several studies have consistently demonstrated abnormalities in the unisensory processing of face and voice in schizophrenia (SZ), the extent of abnormalities in the simultaneous processing of both types of information remains unclear. To address this issue, we used event-related potentials (ERP) methodology to probe the multisensory integration of face and non-semantic sounds in schizophrenia. EEG was recorded from 18 schizophrenia patients and 19 healthy control (HC) subjects in three conditions: neutral faces (visual condition-VIS); neutral non-semantic sounds (auditory condition-AUD); neutral faces presented simultaneously with neutral non-semantic sounds (audiovisual condition-AUDVIS). When compared with HC, the schizophrenia group showed less negative N170 to both face and face-voice stimuli; later P270 peak latency in the multimodal condition of face-voice relative to unimodal condition of face (the reverse was true in HC); reduced P400 amplitude and earlier P400 peak latency in the face but not in the voice-face condition. Thus, the analysis of ERP components suggests that deficits in the encoding of facial information extend to multimodal face-voice stimuli and that delays exist in feature extraction from multimodal face-voice stimuli in schizophrenia. In contrast, categorization processes seem to benefit from the presentation of simultaneous face-voice information. Timepoint by timepoint tests of multimodal integration did not suggest impairment in the initial stages of processing in schizophrenia.

  15. An Introductory Infrared Spectroscopy Experiment.

    ERIC Educational Resources Information Center

    Hess, Kenneth R.; Smith, Wendy D.; Thomsen, Marcus W.; Yoder, Claude H.

    1995-01-01

    Describes a project designed to introduce infrared spectroscopy as a structure-determination technique. Students are introduced to infrared spectroscopy fundamentals then try to determine the identity of an unknown liquid from its infrared spectrum and molecular weight. The project demonstrates that only rarely can the identity of even simple…

  16. The light meson spectroscopy program

    SciTech Connect

    Smith, Elton S.

    2014-06-01

    Recent discoveries of a number of unexpected new charmomium-like meson states at the BaBar and Belle B-factories have demonstrated how little is still known about meson spectroscopy. In this talk we will review recent highlights of the light quark spectroscopy from collider and fixed target experiments.

  17. Industrial applications of Raman spectroscopy

    NASA Astrophysics Data System (ADS)

    Grasselli, J. G.; Walder, F.; Petty, C.; Kemeny, G.

    1993-03-01

    In the last two decades, Raman spectroscopy has matured as an important method for the study of molecules and complex molecular systems. This is evident from the number of fine texts and the many review articles which have been published describing theory and applications of Raman spectroscopy over a very broad range of subjects (1-10). Raman spectroscopy is the essential partner to infrared spectroscopy for a complete vibrational analysis of a molecule in structure determinations. From the understanding developed on small molecules, theory was extended to interpret the spectra of larger systems such as polymers, biological molecules, and ordered condensed phases. The contribution of Raman spectroscopy to these areas has been significant. It was the development of commercial lasers in the 1960s which spurred the renewed interest in the Raman technique. But applications were still limited for highly fluorescing or intensely colored systems. In 1986, a breakthrough paper by Hirschfeld and Chase (11) described the use of near-infrared laser excitation and a commercial interferometer-based FT-IR spectrometer to record FT-Raman spectra. Significant advantages included the inherent multiplex, throughput and data processing features of the FT interferometers and the use of a ND:YAG laser (1.064 μm) which dramatically decreased problems with sample fluorescence and decomposition. A deluge of papers describing applications of FT-Raman spectroscopy can be found in the Journal of Raman Spectroscopy, Spectrochimica Acta (special issues 40A ad 47A), and Applied Spectroscopy since then.

  18. Spectroscopy, Understanding the Atom Series.

    ERIC Educational Resources Information Center

    Hellman, Hal

    This booklet is one of the "Understanding the Atom" Series. The science of spectroscopy is presented by a number of topics dealing with (1) the uses of spectroscopy, (2) its origin and background, (3) the basic optical systems of spectroscopes, spectrometers, and spectrophotometers, (4) the characteristics of wave motion, (5) the…

  19. Wavelength-modulated photocapacitance spectroscopy

    NASA Technical Reports Server (NTRS)

    Kamieniecki, E.; Lagowski, J.; Gatos, H. C.

    1980-01-01

    Derivative deep-level spectroscopy was achieved with wavelength-modulated photocapacitance employing MOS structures and Schottky barriers. The energy position and photoionization characteristics of deep levels of melt-grown GaAs and the Cr level in high-resistivity GaAs were determined. The advantages of this method over existing methods for deep-level spectroscopy are discussed.

  20. Infrared heterodyne spectroscopy in astronomy

    NASA Technical Reports Server (NTRS)

    Betz, A.

    1980-01-01

    A heterodyne spectrometer was constructed and applied to problems in infrared astronomical spectroscopy. The instrument offers distinct observational advantages for the detection and analysis of individual spectral lines at Doppler-limited resolution. Observations of carbon dioxide in planetary atmospheres and ammonia in circumstellar environments demonstrate the substantial role that infrared heterodyne techniques will play in the astronomical spectroscopy of the future.

  1. Laser Spectroscopy and Frequency Combs

    NASA Astrophysics Data System (ADS)

    Hänsch, Theodor W.; Picqué, Nathalie

    2013-12-01

    The spectrum of a frequency comb, commonly generated by a mode-locked femtosecond laser consists of several hundred thousand precisely evenly spaced spectral lines. Such laser frequency combs have revolutionized the art measuring the frequency of light, and they provide the long-missing clockwork for optical atomic clocks. The invention of the frequency comb technique has been motivated by precision laser spectroscopy of the simple hydrogen atom. The availability of commercial instruments is facilitating the evolution of new applications far beyond the original purpose. Laser combs are becoming powerful instruments for broadband molecular spectroscopy by dramatically improving the resolution and recording speed of Fourier spectrometers and by creating new opportunities for highly multiplexed nonlinear spectroscopy, such as two-photon spectroscopy or coherent Raman spectroscopy. Other emerging applications of frequency combs range from fundamental research in astronomy, chemistry, or attosecond science to telecommunications and satellite navigation.

  2. Combining scanning probe microscopy and x-ray spectroscopy

    PubMed Central

    2011-01-01

    A new versatile tool, combining Shear Force Microscopy and X-Ray Spectroscopy was designed and constructed to obtain simultaneously surface topography and chemical mapping. Using a sharp optical fiber as microscope probe, it is possible to collect locally the visible luminescence of the sample. Results of tests on ZnO and on ZnWO4 thin layers are in perfect agreement with that obtained with other conventional techniques. Twin images obtained by simultaneous acquisition in near field of surface topography and of local visible light emitted by the sample under X-Ray irradiation in synchrotron environment are shown. Replacing the optical fibre by an X-ray capillary, it is possible to collect local X-ray fluorescence of the sample. Preliminary results on Co-Ti sample analysis are presented. PMID:21711848

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

    NASA Astrophysics Data System (ADS)

    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).

  4. Real-time multiplexed digital cavity-enhanced spectroscopy

    DOE PAGES

    Boyson, Toby K.; Dagdigian, Paul J.; Pavey, Karl D.; ...

    2015-10-01

    Cavity-enhanced spectroscopy is a sensitive optical absorption technique but one where the practical applications have been limited to studying small wavelength ranges. In addition, this Letter shows that wideband operation can be achieved by combining techniques usually reserved for the communications community with that of cavity-enhanced spectroscopy, producing a multiplexed real-time cavity-enhanced spectrometer. We use multiple collinear laser sources operating asynchronously and simultaneously while being detected on a single photodetector. This is synonymous with radio frequency (RF) cellular systems in which signals are detected on a single antenna but decoded uniquely. Here, we demonstrate results with spectra of methyl salicylatemore » and show parts-per-billion per root hertz sensitivity measured in real-time.« less

  5. Photothermal cantilever deflection spectroscopy of a photosensitive polymer

    SciTech Connect

    Yun, Minhyuk; Lee, Dongkyu; Jung, Namchul; Jeon, Sangmin; Kim, Seonghwan; Chae, Inseok; Thundat, Thomas

    2012-05-14

    The mechanical and chemical information of a poly(methyl methacrylate) (PMMA) film on a microcantilever were simultaneously acquired by photothermal cantilever deflection spectroscopy as a function of ultraviolet (UV) irradiation time. Nanomechanical infrared (IR) spectra from the PMMA-coated microcantilever agreed well with the Fourier transform infrared spectroscopy (FTIR) spectra of PMMA on gold-coated silicon wafer. The decreasing intensities of nanomechanical IR peaks represent chemical as well as mechanical information of UV radiation-induced photodegradation processes in the PMMA which cannot be obtained by a conventional FTIR technique. The observed decrease in the resonance frequency of the microcantilever is related to the change in the Young's modulus of the PMMA under UV exposure.

  6. Analysis of milk by FT-Raman spectroscopy.

    PubMed

    Mazurek, Sylwester; Szostak, Roman; Czaja, Tomasz; Zachwieja, Andrzej

    2015-06-01

    Fat, protein, carbohydrates and dry matter were quantified in commercial bovine milk samples, with the relative standard errors of prediction (RSEP) in the 3.4-6.1% range, using the partial least squares (PLS) method based on Raman spectra of liquid milk samples. Results of a better quality were obtained from a PLS model derived from IR spectra registered using single reflection ATR diamond accessory, which yielded RSEP values of 2.4-4.4%. The data indicated IR single reflection ATR spectroscopy and Raman spectroscopy in combination with multivariate modelling using the PLS method, allowed for the reliable, simultaneous quantitative determination of macronutrients in milk. The low signal to noise ratio of Raman spectra affects the quality of fat quantification especially for strongly defatted milk samples.

  7. Real-time multiplexed digital cavity-enhanced spectroscopy

    SciTech Connect

    Boyson, Toby K.; Dagdigian, Paul J.; Pavey, Karl D.; Fitzgerald, Nicholas J.; Spence, Thomas G.; Moore, David S.; Harb, Charles C.

    2015-10-01

    Cavity-enhanced spectroscopy is a sensitive optical absorption technique but one where the practical applications have been limited to studying small wavelength ranges. In addition, this Letter shows that wideband operation can be achieved by combining techniques usually reserved for the communications community with that of cavity-enhanced spectroscopy, producing a multiplexed real-time cavity-enhanced spectrometer. We use multiple collinear laser sources operating asynchronously and simultaneously while being detected on a single photodetector. This is synonymous with radio frequency (RF) cellular systems in which signals are detected on a single antenna but decoded uniquely. Here, we demonstrate results with spectra of methyl salicylate and show parts-per-billion per root hertz sensitivity measured in real-time.

  8. Measuring Rocket Engine Temperatures with Hydrogen Raman Spectroscopy

    NASA Technical Reports Server (NTRS)

    Wehrmeyer, Joseph A.

    2002-01-01

    Laser-based combustion diagnostics, such as single-pulse UV Raman spectroscopy and visible Raman spectroscopy, have been successfully applied to optically-accessible rocket-like test articles. If an independent pressure measurement is available, Raman major species concentration measurements can also provide a temperature measurement. However it is desirable to obtain a Raman-derived temperature measurement without the need for simultaneous pressure measurement, especially when chamber pressure may vary spatially. This report describes Raman temperature measurements obtained by exploiting the variation in shape of the H2 Raman spectrum. Hydrogen is advantageous since it is ubiquitous in H2-O2 systems and its Raman spectrum is simpler than for other diatomics. However the influence of high pressure on the H2 Raman spectrum must be investigated. At moderate pressures, well below those of rocket engines, the Raman spectra of O2 and N2 are known to become featureless due to collisional broadening.

  9. Operando fuel cell spectroscopy

    NASA Astrophysics Data System (ADS)

    Kendrick, Ian Michael

    The active state of a catalyst only exists during catalysis (1) provided the motivation for developing operando spectroscopic techniques. A polymer electrolyte membrane fuel cell (PEMFC) was designed to interface with commercially available instruments for acquisition of infrared spectra of the catalytic surface of the membrane electrode assembly (MEA) during normal operation. This technique has provided insight of the complex processes occurring at the electrode surface. Nafion, the solid electrolyte used in most modern-day polymer electrolyte membrane fuel cells (PEMFC), serves many purposes in fuel cell operation. However, there is little known of the interface between Nafion and the electrode surface. Previous studies of complex Stark tuning curves of carbon monoxide on the surface of a platinum electrode were attributed the co-adsorption of bisulfite ions originating from the 0.5M H2SO4 electrolyte used in the study(2). Similar tuning curves obtained on a fuel cell MEA despite the absence of supplemental electrolytes suggest the adsorption of Nafion onto platinum (3). The correlation of spectra obtained using attenuated total reflectance spectroscopy (ATR) and polarization modulated IR reflection-absorption spectroscopy (PM-IRRAS) to a theoretical spectrum generated using density functional theory (DFT) lead to development of a model of Nafion and platinum interaction which identified participation of the SO3- and CF3 groups in Nafion adsorption. The use of ethanol as a fuel stream in proton exchange membrane fuel cells provides a promising alternative to methanol. Relative to methanol, ethanol has a greater energy density, lower toxicity and can be made from the fermentation of biomass(4). Operando IR spectroscopy was used to study the oxidation pathway of ethanol and Stark tuning behavior of carbon monoxide on Pt, Ru, and PtRu electrodes. Potential dependent products such as acetaldehyde, acetic acid and carbon monoxide are identified as well as previously

  10. Dual-wavelength quantum cascade laser for trace gas spectroscopy

    SciTech Connect

    Jágerská, J.; Tuzson, B.; Mangold, M.; Emmenegger, L.; Jouy, P.; Hugi, A.; Beck, M.; Faist, J.; Looser, H.

    2014-10-20

    We demonstrate a sequentially operating dual-wavelength quantum cascade laser with electrically separated laser sections, emitting single-mode at 5.25 and 6.25 μm. Based on a single waveguide ridge, this laser represents a considerable asset to optical sensing and trace gas spectroscopy, as it allows probing multiple gas species with spectrally distant absorption features using conventional optical setups without any beam combining optics. The laser capability was demonstrated in simultaneous NO and NO{sub 2} detection, reaching sub-ppb detection limits and selectivity comparable to conventional high-end spectroscopic systems.

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

    SciTech Connect

    Migliori, Albert; Betts, J; Trugman, A; Mielke, C H; Mitchell, J N; Ramos, M; Stroe, I

    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.

  12. Cavity Ring-Down Spectroscopy for Trace Gas Analysis

    NASA Astrophysics Data System (ADS)

    Czy Zewski, A.; Ernst, K.; Karasinski, G.; Lange, H.; Rairoux, P.; Skubiszak, W.; Stacewicz, T.

    2002-08-01

    Cavity Ring-Down Spectroscopy (CRDS) is a novel technique of measurement of the absorption coefficient based on determination of the Q-factor of an optical resonator which contains the investigated absorber. We present a modified CRDS method (so called CRD-Spectrography) in which the signal is simultaneously analysed within a broad spectral range. This technique was used for monitoring of trace gases (nitrogen oxides) in the atmosphere. Another modification of CRDS technique allows to determine the transient absorption coefficient. This method was applied for studies of kinetics of CH radical produced by pulsed electric discharge in methane.

  13. Project LITE Spectroscopy

    NASA Astrophysics Data System (ADS)

    Weeks, E.; Brecher, K.; Carr, P.; Garik, P.

    2003-12-01

    Spectroscopy is one of the most important tools used by astronomers to disentangle information about the universe. However, it is one of the most challenging subjects in undergraduate astronomy courses. Among the most difficult concepts for students to master are Kirchhoff's laws, blackbody radiation, the Stefan-Boltzmann law, Wien's law, the nature and causes of emission and absorption lines, and the relation of spectra to the underlying astronomical and physical processes producing them. Students often seem baffled by the connection between a spectrum seen visually as a color band and the same spectrum plotted graphically as intensity versus wavelength or frequency. Project LITE (Light Inquiry Through Experiments) is a software, curriculum, and materials development project at Boston University. As part of the project, we are currently developing a suite of spectroscopic tools for astronomy education. We are also assessing their effectiveness in improving conceptual understanding of spectroscopic phenomena by astronomy students at the undergraduate level. The spectroscopy component of Project LITE includes take-home laboratory materials and experiments, which are integrated with web-based software. We have also developed a novel quantitative handheld binocular spectrometer (patent pending). Here we present an overview of the Project LITE homelab kits and curriculum, the Spectrum Explorer, and the Project LITE spectrometer. The homelab experiments and the Spectrum Explorer have been tested with students in a non-science majors introductory astronomy course as well as in a School of Education course for prospective elementary school science teachers. We present preliminary results of pre- and post-instruction surveys of student understanding of various spectral properties of light both from students who used the homelab activities and the Spectrum Explorer and those who did not. The Spectrum Explorer (along with many other applets about both the physical and

  14. Long-path Atmospheric Measurements Using Dual Frequency Comb Spectroscopy

    NASA Astrophysics Data System (ADS)

    Cossel, K.; Truong, G. W.; Waxman, E.; Baumann, E.; Giorgetta, F.; Rieker, G. B.; Sinclair, L.; Swann, W.; Coddington, I.; Newbury, N.

    2015-12-01

    Dual frequency comb (DFC) spectroscopy is a new technique that combines broad spectral bandwidth, high spectral resolution, rapid data acquisition, and high sensitivity. In addition, unlike standard Fourier-transform spectroscopy, it has an almost ideal instrument lineshape function and does not require recalibration. These features make DFC spectroscopy well suited for accurate measurements of multiple species simultaneously. We have recently demonstrated DFC-based open-path measurements of several greenhouse gases in the 1.6-1.67 μm (6250-6000 cm-1) spectral region with 2 km of path length [Rieker et al, 2014]. This initial demonstration used laboratory-based lasers and achieved a sensitivity of 2.3 ppbv for CH4, 1 ppmv for CO2, and <1 ppmv for H2O and HDO with 5 minute measurement times. We are currently developing a portable system that will cover a wider spectral region (about 1.3-2.1 μm or 7700-4750 cm-1) with improved sensitivity. In this talk, we will provide an introduction to dual frequency comb spectroscopy and then discuss ongoing improvements to the open-path system. G. B. Rieker, F. R. Giorgetta, W. C. Swann, J. Kofler, A. M. Zolot, L. C. Sinclair, E. Baumann, C. Cromer, G. Petron, C. Sweeney, P. P. Tans, I. Coddington, and N. R. Newbury (2014), Frequency-comb-based remote sensing of greenhouse gases over kilometer air paths, Optica, 1(5), 290-298.

  15. Atmospheric and environmental sensing by photonic absorption spectroscopy

    NASA Astrophysics Data System (ADS)

    Chen, W.; Wu, T.; Zhao, W.; Wysocki, G.; Cui, X.; Lengignon, C.; Maamary, R.; Fertein, E.; Coeur, C.; Cassez, A.; Wang, Y.; Zhang, W.; Gao, X.; Liu, W.; Dong, F.; Zha, G.; Zheng, Xu; Wang, T.

    2013-01-01

    Chemically reactive short-lived species play a crucial role in tropospheric processes affecting regional air quality and global climate change. Contrary to long-lived species (such as greenhouse gases), fast, accurate and precise monitoring changes in concentration of atmospheric short-lived species represents a real challenge due to their short life time (~1 s for OH radical) and very low concentration in the atmosphere (down to 106 molecules/cm3, corresponding to 0.1 pptv at standard temperature and pressure). We report on our recent progress in instrumentation developments for spectroscopic sensing of trace reactive species. Modern photonic sources such as quantum cascade laser (QCL), distributed feedback (DFB) diode laser, light emitting diode (LED), difference-frequency generation (DFG) parametric source are implemented in conjunction with highsensitivity spectroscopic measurement techniques for : (1) nitrous acid (HONO) monitoring by QCL-based long optical pathlength absorption spectroscopy and LED-based IBBCEAS (incoherent broadband cavity-enhanced absorption spectroscopy); (2) DFB laser-based hydroxyl free radical (OH) detection using WM-OA-ICOS (wavelength modulation off-axis integrated cavity output spectroscopy) and FRS (Faraday rotation spectroscopy), respectively; (3) nitrate radical (NO3) and nitrogen dioxide (NO2) simultaneous measurements with IBBCEAS approach. Applications in field observation and in smog chamber study will be presented.

  16. Neutron Speed Echo Spectroscopy

    NASA Astrophysics Data System (ADS)

    Ioffe, A.

    Neutron speed echo (NSPE) technique is in a way a generalization of the neutron spin echo (NSE) technique. Similar to NSE spectrometers, the resolution of such NSPE spectrometer is extremely high and is not connected with the monochromatization of the incoming beam. However, in contrast to NSE spectrometers, the operation of proposed spectrometer does not necessarily require a polarized neutron beam. Such decoupling the polarization and the resolution is in clear contrast to NSE technique. Because the resolution of a NSPE spectrometer can be a few orders higher than the resolution of NSE spectrometers, one can achieve the energy resolution of about 10-14 eV by the use of ultra cold neutrons; a fact that can be used in some fundamental physics experiments. Though the scattering on the sample impose limitations on the resolution of a NSPE spectrometer, the use of the proposed technique in a low-resolution mode can be useful in the combination with triple-axis spectrometers and allow for the significant improvement of their energy resolution, however, without the use of polarized neutrons. This fact opens new possibilities for the study of magnetic phenomena in solids, where the NSE method is principally not applicable because of the neutron precession in the sample, especially by combining polarization analysis with high-resolution spectroscopy. The proposed technique also allows for an easy implementation of the principle of the NSE focusing, when the resolution ellipse is aligned along a dispersion curve.

  17. Infrared diode laser spectroscopy

    NASA Astrophysics Data System (ADS)

    Civiš, S.; Cihelka, J.; Matulková, I.

    2010-12-01

    Three types of lasers (double-heterostructure 66 K InAsSb/InAsSbP laser diode, room temperature, multi quantum wells with distributed feedback (MQW with DFB) (GaInAsSb/AlGaAsSb based) diode laser and vertical cavity surface emitting lasers (VCSELs) (GaSb based) have been characterized using Fourier transform emission spectroscopy and compared. The photoacoustic technique was employed to determine the detection limit of formaldehyde (less than 1 ppmV) for the strongest absorption line of the v3 + v5 band in the emission region of the GaInAsSb/AlGaAsSb diode laser. The detection limit (less than 10 ppbV) of formaldehyde was achieved in the 2820 cm-1 spectral range in case of InAsSb/InAsSbP laser (fundamental bands of v1, v5). Laser sensitive detection (laser absorption together with high resolution Fourier transform infrared technique including direct laser linewidth measurement, infrared photoacoustic detection of neutral molecules (methane, form-aldehyde) is discussed. Additionally, very sensitive laser absorption techniques of such velocity modulation are discussed for case of laser application in laboratory research of molecular ions. Such sensitive techniques (originally developed for lasers) contributed very much in identifying laboratory microwave spectra of a series of anions (C6H-, C4H-, C2H-, CN-) and their discovery in the interstellar space (C6H-, C4H-).

  18. Relic Neutrino Absorption Spectroscopy

    SciTech Connect

    Eberle, b

    2004-01-28

    Resonant annihilation of extremely high-energy cosmic neutrinos on big-bang relic anti-neutrinos (and vice versa) into Z-bosons leads to sizable absorption dips in the neutrino flux to be observed at Earth. The high-energy edges of these dips are fixed, via the resonance energies, by the neutrino masses alone. Their depths are determined by the cosmic neutrino background density, by the cosmological parameters determining the expansion rate of the universe, and by the large redshift history of the cosmic neutrino sources. We investigate the possibility of determining the existence of the cosmic neutrino background within the next decade from a measurement of these absorption dips in the neutrino flux. As a by-product, we study the prospects to infer the absolute neutrino mass scale. We find that, with the presently planned neutrino detectors (ANITA, Auger, EUSO, OWL, RICE, and SalSA) operating in the relevant energy regime above 10{sup 21} eV, relic neutrino absorption spectroscopy becomes a realistic possibility. It requires, however, the existence of extremely powerful neutrino sources, which should be opaque to nucleons and high-energy photons to evade present constraints. Furthermore, the neutrino mass spectrum must be quasi-degenerate to optimize the dip, which implies m{sub {nu}} 0.1 eV for the lightest neutrino. With a second generation of neutrino detectors, these demanding requirements can be relaxed considerably.

  19. Broadband transmission EPR spectroscopy.

    PubMed

    Hagen, Wilfred R

    2013-01-01

    EPR spectroscopy employs a resonator operating at a single microwave frequency and phase-sensitive detection using modulation of the magnetic field. The X-band spectrometer is the general standard with a frequency in the 9-10 GHz range. Most (bio)molecular EPR spectra are determined by a combination of the frequency-dependent electronic Zeeman interaction and a number of frequency-independent interactions, notably, electron spin - nuclear spin interactions and electron spin - electron spin interactions, and unambiguous analysis requires data collection at different frequencies. Extant and long-standing practice is to use a different spectrometer for each frequency. We explore the alternative of replacing the narrow-band source plus single-mode resonator with a continuously tunable microwave source plus a non-resonant coaxial transmission cell in an unmodulated external field. Our source is an arbitrary wave digital signal generator producing an amplitude-modulated sinusoidal microwave in combination with a broadband amplifier for 0.8-2.7 GHz. Theory is developed for coaxial transmission with EPR detection as a function of cell dimensions and materials. We explore examples of a doublet system, a high-spin system, and an integer-spin system. Long, straigth, helical, and helico-toroidal cells are developed and tested with dilute aqueous solutions of spin label hydroxy-tempo. A detection limit of circa 5 µM HO-tempo in water at 800 MHz is obtained for the present setup, and possibilities for future improvement are discussed.

  20. Meson spectroscopy at COMPASS

    NASA Astrophysics Data System (ADS)

    Grube, Boris

    2016-11-01

    The goal of the COMPASS experiment at CERN is to study the structure and dynamics of hadrons. The two-stage spectrometer used by the experiment has large acceptance and covers a wide kinematic range for charged as well as neutral particles and can therefore measure a wide range of reactions. The spectroscopy of light mesons is performed with negative (mostly π-) and positive (p, π+) hadron beams with a momentum of 190 GeV/c. The light-meson spectrum is measured in different final states produced in diffractive dissociation reactions with squared four-momentum transfer t to the target between 0.1 and 1.0 (GeV=c)2. The flagship channel is the π-π-π+ final state, for which COMPASS has recorded the currently world's largest data sample. These data not only allow to measure the properties of known resonances with high precision, but also to observe new states. Among these is a new axial-vector signal, the a1(1420), with unusual properties. Novel analysis techniques have been developed to extract also the amplitude of the π-π+ subsystem as a function of 3π mass from the data. The findings are confirmed by the analysis of the π-π0π0 final state.