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Sample records for alpha spectrometry

  1. Alpha spectrometry and secondary ion mass spectrometry of thorium

    International Nuclear Information System (INIS)

    Strisovska, Jana; Kuruc, Jozef; Galanda, Dusan; Matel, Lubomir; Velic, Dusan; Aranyosiova, Monika

    2009-01-01

    A sample of thorium content on steel discs was prepared by electrodeposition with a view to determining the natural thorium isotope. Thorium was determined by alpha spectrometry and by secondary ion mass spectrometry and the results of the two methods were compared

  2. Determination of plutonium-238 in plutonium by alpha spectrometry

    International Nuclear Information System (INIS)

    Aggarwal, S.K.; Jain, H.C.; Mathews, C.K.; Ramaniah, M.V.

    1975-01-01

    A method is presented for the determination of 238 Pu in plutonium samples by alpha spectrometry. Various factors attributing towards the energy degradation, a problem usually encountered in alpha spectrometry, are discussed. A computer programme is given for the evaluation of peak areas when the alpha spectrum is degraded. The results are compared with those obtained by mass spectrometry. (author)

  3. Performance Test of Alpha Spectrometry for Environmental Radioactivity Analysis

    International Nuclear Information System (INIS)

    Choi, Jung Youn; Yoon, Jong-Ho; Han, Ki-Tek; Ahn, Gil Hoon

    2015-01-01

    Environmental samples are analyzed by various methods such as, ICP-MS (inductively coupled plasma mass spectrometry), AMS (accelerator mass spectrometry) TIMS (thermal ionization mass spectrometry), HRGS (high resolution gamma spectrometry) and alpha /beta particle analysis. In this study, we will described the result of performance test using alpha spectrometry for analyzing environmental samples. Measurement data of the U activity using SRM based on extraction chromatography with UTEVA resin. It should be effective way to separate of uranium isotope for the measurement of alpha spectrometry. But, the result of this measurement data is higher than another recovery data. Also concentration of U data is lack of consistency. We leave out of consideration many effect of factors about influence in the experiment process. In the future work, we will try to reduce the step of experiment process and reflect the uncertainty factors

  4. Concentration of Radon Progeny in Air by Alpha Spectrometry Measurement

    International Nuclear Information System (INIS)

    Acena, M. L.; Crespo, M. T.

    1989-01-01

    The concentration of radon progeny in air has been determined by alpha spectrometry measurement of 214 Po and 318 Po. A known volume of air was passed through a filter, then the alpha activity was directly measured on this filter. (Author) 15 refs

  5. Measurement of radium micro-precipitates using alpha spectrometry and total alpha counting methods

    International Nuclear Information System (INIS)

    Hosseini, T.; Fathivand, A.A.

    2004-01-01

    Background: This study consists of two parts. The first part deals with both qualitative and quantitative analysis of 226 Ra suing alpha spectrometry measurement method. In the second part, the percentage of radioactive equilibrium between 226 Radium and its daughter products were determined by alpha spectrometry and total alpha measurement system after elapsed time of 15 days from precipitation. Materials and methods: Twelve 226 Radium samples as Barium-Radium Sulfate in form of micro-precipitates on millipore and What man 42 filters were prepared. An alpha spectrometer with surface barrier detector and a total alpha measurement system consists of scintillation crystal assembly Zinc Silver were used for counting. Results: The minimum detection limit of alpha spectrometry and total alpha counting for 226 Radium measurements in samples for counting time equal to 10000 seconds, were found to be 3.7 mBq and 15.8 mBq respectively. Results from total alpha counting showed that radioactive equilibrium between 226 Radium and its daughter products reached to about 92%± 3.5, where as, in the case of alpha spectrometry radioactive equilibrium, it was destroyed due to vacuum during counting the sample. Also in case of alpha spectrometry, the optimum sample to detector distance, was found to be 0.5 centimeter. Conclusion: From this study it was concluded that micro-precipitation can be used as a proper method for sample preparation and alpha spectrometry due to its lower detection limit to measure low concentration of 224 Radium and 226 Radium in these precipitates, prepared from different samples. Besides it is not time consuming and sources can be measured immediately after sample preparation

  6. Liquid scintillation alpha particle spectrometry. Progress report

    International Nuclear Information System (INIS)

    Bell, L.L.; Hakooz, S.A.; Johnson, L.O.; Nieschmidt, E.B.; Meikrantz, D.H.

    1979-12-01

    Objective to develop a technique whereby Pu may be put into solution, extracted by solvent extraction into a suitable extractive scintillant and subsequently counted. Presented here are results of attempts to separate beta and alpha activities through pulse shape discrimination. A qualitative discussion is given which yields alpha particle peak widths, resolution and response. The detection efficiency for alpha particles in a liquid scintillant is 100%. Present detection sensitivities of the equipment being used are: 4.5 x 10 -6 μCi (100 s), 1.2 x 10 -6 μCi (1000 s), and 4.0 x 10 -7 μCi (10,000 s) at the 3 sigma level. The detectability of a particular alpha-emitting species is strongly dependent upon the population of other species. The ability to discriminate depends upon the system resolution. 14 figures, 2 tables

  7. 226Ra determination in phosphogypsum by alpha-particle spectrometry

    International Nuclear Information System (INIS)

    Aguado, J.L.; Bolivar, J.P.; Garcia-Tenorio, R.

    1999-01-01

    A radiochemical method for 226 Ra determination by alpha-particle spectrometry in environmental samples has been developed in our laboratory. The method has been validated by measurements in samples with known concentrations of this radionuclide and it has been applied in studies related to 226 Ra behaviour in phosphogypsum (the main by-product of producing phosphoric acid from phosphate rocks). (author)

  8. 226Ra determination in phosphogypsum by alpha-particle spectrometry

    Science.gov (United States)

    Aguado, J. L.; Bolívar, J. P.; García-Tenorio, R.

    1999-01-01

    A radiochemical method for226Ra determination by alpha-particle spectrometry in environmental samples has been developed in our laboratory. The method has been validated by measurements in samples with known concentrations of this radionuclide and it has been applied in studies related to226Ra behaviour in phosphogypsum (the main by-product of producing phosphoric acid from phosphate rocks).

  9. New advanced in alpha spectrometry by liquid scintillation methods

    Energy Technology Data Exchange (ETDEWEB)

    McDowell, W.J.; Case, G.N.

    1979-01-01

    Although the ability to count alpha particles by liquid scintillation methods has been long recognized, limited use has been made of the method because of problems of high background and alpha energy identification. In recent years some new developments in methods of introducing the alpha-emitting nuclide to the scintillator, in detector construction, and in electronics for processing the energy analog and time analog signals from the detector have allowed significant alleviation of the problems of alpha spectrometry by liquid scintillation. Energy resolutions of 200 to 300 keV full peak width at half maximum and background counts of < 0.01 counts/min with rejection with rejection of > 99% of all beta plus gamma interference is now possible. Alpha liquid scintillation spectrometry is now suitable for a wide range of applications, from the accurate quantitative determination of relatively large amounts of known nuclides in laboratory-generated samples to the detection and identification of very small, subpicocurie amounts of alpha emitters in environmental-type samples. Suitable nuclide separation procedures, sample preparation methods, and instrument configurations are available for a variety of analyses.

  10. Simultaneous determination of U and Pu isotopes by alpha spectrometry

    International Nuclear Information System (INIS)

    Equillor, H.E.; Campos, J.M.

    2011-01-01

    Determination of actinides by alpha spectrometry is usually carried out after full separation of each of the components of the sample. The procedure presented in this paper permits U and Pu isotopes to be measured together allowing faster sample processing and measurement. The method consists in the extraction with tributyl phosphate of U and Pu isotopes from the rest of the matrix, followed by a cathodic electrodeposition to obtain alpha spectrometry suitable pieces. It can be applied to various environmental samples, such as water, filters and soil (about 0.5 g of solid sample for the described conditions). High-quality electroplated discs are essential for simultaneous processing, so a technique to achieve this requirement is also explained. (authors) [es

  11. Determination of Ra in environmental samples by. alpha. -particle spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Hancock, G.J.; Martin, P. (Alligator Rivers Region Research Inst., Jabiru, N.T. (Australia))

    1991-01-01

    A method of determining Ra isotopes by {alpha}-particle spectrometry using {sup 225}Ra as a yield tracer has been developed. Radium is coprecipitated with lead sulphate, purified using ion exchange techniques, and electrodeposited from an aqueous/ethanol solution. The procedure can be easily completed in 1 day. Tracer recoveries are typically 80%, and the resolution obtained is typically 40 keV FWHM. (author).

  12. Response of commercial photodiodes for application in alpha spectrometry

    International Nuclear Information System (INIS)

    Ferreira Filho, Alfredo Lopes

    1998-06-01

    The use of semiconductor detector for ionizing radiations spectrometry and dosimetry has been growing in the last years due to its characteristics of fast response, good efficiency for unit of volume and excellent resolution. Since the working principle of a semiconductor detector is identical to that of the semiconductor junctions of commercial electronic devices, a study was carried out on the PIN-photodiodes response, aiming at set up an alpha spectrometry system of low cost and easy acquisition. The tested components have the following characteristics: active area varying between 13.2 and 25 mm 2 , window of thickness equal or lower than 57 mg/cm 2 , depletion area with depth ranging from 10 to 300 μm and junction capacitance of 16 to 20 pF.Am-241, Cm-244, U-233 and Np-237 alpha sources produced by electrodeposition were used to evaluate the response of the devices as a function of the radiation energy. The results have shown a linear response of the photodiodes with the incident alpha particle energy. The resolution varied from 1.6% to 0.45% and the better detection efficiency found was about 7.2. The low cost of the photodiodes and the excellent results obtained at room temperature make such components very attractive for teaching purposes for environmental monitoring. (author)

  13. Iterative inversion of gamma or alpha spectrometry data

    International Nuclear Information System (INIS)

    Nordemann, D.J.R.

    1985-12-01

    Gamma - and alpha ray spectrometry data are processed by an iterative regression method (Wolberg, 1967) to obtain the activities or yields of radionuclides. This method, applied to Nuclear Geophysics Research, permits the use of either selected energy bands or of all the channels one by one. It may be easily programmed in popular microcomputers and offers many advantages such as the use of mixtures of radionuclides for the calibrations and the treatment of the uncertainties on the measurements and results. Several conclusions about the method and options of nuclear data processing are presented. (Author) [pt

  14. Chemical vapor deposition (CVD) of uranium for alpha spectrometry

    International Nuclear Information System (INIS)

    Ramirez V, M. L.; Rios M, C.; Ramirez O, J.; Davila R, J. I.; Mireles G, F.

    2015-09-01

    The uranium determination through radiometric techniques as alpha spectrometry requires for its proper analysis, preparation methods of the source to analyze and procedures for the deposit of this on a surface or substrate. Given the characteristics of alpha particles (small penetration distance and great loss of energy during their journey or its interaction with the matter), is important to ensure that the prepared sources are thin, to avoid problems of self-absorption. The routine methods used for this are the cathodic electro deposition and the direct evaporation, among others. In this paper the use of technique of chemical vapor deposition (CVD) for the preparation of uranium sources is investigated; because by this, is possible to obtain thin films (much thinner than those resulting from electro deposition or evaporation) on a substrate and comprises reacting a precursor with a gas, which in turn serves as a carrier of the reaction products to achieve deposition. Preliminary results of the chemical vapor deposition of uranium are presented, synthesizing and using as precursor molecule the uranyl acetylacetonate, using oxygen as carrier gas for the deposition reaction on a glass substrate. The uranium films obtained were found suitable for alpha spectrometry. The variables taken into account were the precursor sublimation temperatures and deposition temperature, the reaction time and the type and flow of carrier gas. Of the investigated conditions, two depositions with encouraging results that can serve as reference for further work to improve the technique presented here were selected. Alpha spectra obtained for these depositions and the characterization of the representative samples by scanning electron microscopy and X-ray diffraction are also presented. (Author)

  15. Determination of plutonium isotopes in bilberry using liquid scintillation spectrometry and alpha-particle spectrometry

    International Nuclear Information System (INIS)

    Seferinoğlu, Meryem; Aslan, Nazife; Kurt, Aylin; Erden, Pınar Esra; Mert, Hülya

    2014-01-01

    This paper presents α-particle spectrometry and liquid scintillation spectrometry methods to determine plutonium isotopes in bilberry. The analytical procedure involves sample preparation steps for ashing, digestion of bilberry samples, radiochemical separation of plutonium radioisotopes and their measurement. The validity of the method was checked for coherence using the ζ test, z-test, relative bias and relative uncertainty outlier tests. The results indicated that the recommended procedures for both measurement systems could be successfully applied for the accurate determination of plutonium activities in bilberry samples. - Highlights: • Sample preparation methods for Pu using LSS and alpha spectrometry developed. • Complete separation of plutonium from interfering radionuclides. • Commercial bilberry was spiked with NPL 2011 (AH-B11144) proficiency test sample. • Results were checked using ζ test, z-test, rel. bias and rel. uncert. outlier tests. • Recommended procedures successfully applied to bilberry samples

  16. Determination of radium-226 by high-resolution alpha spectrometry

    International Nuclear Information System (INIS)

    Sill, C.W.

    1983-01-01

    The determination of radium-226 by alpha spectrometry has been investigated critically to determine experimental conditions under which high resolution and accurate and reliable results can be obtained. Refractory solids such as soils, ores, and tailings from uranium mills are dissolved completely by fusion with potassium fluoride in the presence of barium-133 tracer. The fluoride cake is then transposed with sulfuric acid to a pyrosulfate fusion with simultaneous volatilization of all silica and fluoride. Radium is precipitated with barium already present in the sample by addition of lead perchlorate to a dilute hydrochloric acid solution of the pyrosulfate cake. The resulting insoluble sulfates are dissolved in an alkaline solution of diethylenetriaminepentaacetic acid, and the radium and barium sulfates are reprecipitated with acetic acid. The precipitate is mounted on a membrane filter and analyzed by alpha spectrometry. Water samples are partially evaporated and treated similarly. Resolution of the subsequent alpha spectra is much better than has been achieved previously from barium sulfate, and is almost as good as is obtainable with actinides electrodeposited on polished steel plates. The resolution is about 60 keV full-width-half-maximum with 100 μg of barium on a 1-inch filter with a 450 mm 2 detector at 20% counting efficiency. Recovery is about 97% and accuracy is generally as good as the counting statistics obtained will permit. Grossly inaccurate results can be obtained under certain conditions when barium-133 tracer is used to determine the chemical yield of radium-226. Severe contamination of the surface-barrier detector by polonium-210 and by recoil products of the radium isotopes being counted is demonstrated, amd methods for virtual elimination of both problems are discussed

  17. Performance of alpha spectrometry in the analysis of uranium isotopes in environmental and nuclear materials

    International Nuclear Information System (INIS)

    Carvalho, F.P.; Oliveira, J.M.

    2009-01-01

    The accuracy of alpha spectrometry in the determination of uranium isotopes at various concentrations levels and with various isotope ratios was tested in a round robin international intercomparison exercise. Results of isotope activity/mass and isotope mass ratios obtained by alpha spectrometry were accurate in a wide range of uranium masses and in isotopic ratios typical of depleted, natural, and low enriched uranium samples. Determinations by alpha spectrometry compared very satisfactorily in accuracy with those by mass spectrometry. For example, determination of U isotopes in natural uranium by alpha spectrometry agreed with mass spectrometry determinations at within ±1%. However, the 236 U isotope, particularly if present in activities much lower than 235 U, might not be determined accurately due to overlap in the alpha particle energies of these two uranium isotopes. (author)

  18. Alpha spectrometry enriched uranium urinalysis results from IPEN

    International Nuclear Information System (INIS)

    Lima, Marina Ferreira

    2008-01-01

    Full text: IPEN (Instituto de Pesquisas Energeticas e Nucleares) manufactures the nuclear fuel to its research reactor, the IEA-R1. The CCN (Centro do Ciclo do Combustivel) facility produces the fuel cermets from UF 6 (uranium hexafluoride) enriched to 19.75% in 235 U. The production involves the transformation of the gaseous form in oxides and silicates by ceramic and metallurgical processing. The workers act in more than one step that involves exposition to types F, S and M compounds of uranium. Until 2003, only fluorimetric analysis was carried out by the LRT (Laboratorio de Radiotoxicologia - IPEN) in order to evaluate the intake of uranium, in spite of the sub estimation of the 234 U contribution to the internal doses. Isotopic uranium determination in urine by alpha spectrometry is the current method to monitoring the contribution of 234 U, 235 U and 238 U. Alpha spectrometry data of 164 samples from 84 individuals separate in three categories of workers: routinely work group; special operation group and control group - were analyzed how the isotopic composition excreted by urinary tract corresponds with the level of enrichment and isotopic composition of the plant products. Results show that is hard to estimate these intakes of 234 U and 235 U since these isotopes alpha activities are below the limit of detection or minimum detectable activity (MAD) of this method in the most part of the samples. Only in 22 samples it was possibly to measure the three radionuclides. Not expected high contribution of 234 U activity was found in samples of the control group. No one result over the 234 U and 235 U MAD was found in the samples from the special operation group. Only in 5 samples from the routinely group the levels of 235 U was higher than the levels of others groups. In a complementary study, 3 solid samples of UF 6 , U 2 O 8 and U 3 Si 2 from CCN plant were analyzed to determinate the isotopic uranium composition in these salts, since this composition varies

  19. Determination of 239Pu/240Pu isotopic ratio by high resolution alpha-particle spectrometry

    International Nuclear Information System (INIS)

    Amoudry, F.; Burger, P.

    1983-05-01

    The development of passivated ion-implanted silicon detectors and of very thin alpha-particle sources improves the resolution of alpha-particle spectra and allows to separate energy pics up to now unseparate. The 239 Pu/ 240 Pu isotopic ratio of a mixture has been measured using the alpha spectrometry deconvolution code DEMO [fr

  20. Determination of radium-226 by high-resolution alpha spectrometry

    International Nuclear Information System (INIS)

    Sill, C.W.

    1983-01-01

    Condition were determined under which high resolution and accurate and reliable results can be obtained. Refractory solids are dissolved completely by fusion with KF and Ba-133 tracer. The fluoride cake is then transposed with sulfuric acid to a pyrosulfate fusion. Radium is precipitated with barium by addition of lead perchlorate to a dilute HCl solution of the pyrosulfate cake. The resulting insoluble sulfates are dissolved in an alkaline solution of DTPA and the Ra and Ba sulfates are reprecipitated with acetic acid to produce very small crystals. The precipitate is mounted on 0.1-μm membrane filter and analyzed by alpha spectrometry. Water samples are partially evaporated and treated similarly. Resolution, almost as good as with actinides electrodeposited on polished steel plates, is about 60 keV full-width-half-maximum with 100 μg of barium on a 1-inch filter with a 450 mm 2 detector at 20% counting efficiency. Recovery is about 97%. One solid sample can be prepared for counting in less than 2 hours. Methods are discussed for ensuring reliability of the results. Severe contamination of the surface-barrier detector by polonium-210 and recoil products is discussed

  1. Determination of environmental actinide nuclides and 210Pb (210Po) by low-energy photon spectrometry with alpha-spectrometry

    International Nuclear Information System (INIS)

    Sakanoue, Masanobu; Yamamoto, M.; Komura, Kazuhisa

    1987-01-01

    Low-energy photon spectrometry with alpha spectrometry was used to determine the environmental concentrations of low-level actinides and other nuclides, especially 210 Pb and 210 Po. The isotopic ratio of 2 40 Pu/ 239 Pu was successfully determined by measuring L x -ray/α-ray counting ratio. A reliable method was developed for the determination of extremely low-level 237 Np global fallout in environmental samples. The non-destructive determination by Ge-LEPS for natural 210 Pb in various samples (tobacco leaves, commercially available tobacco, etc.) was also carried out with the determination of 210 Po by alpha spectrometry using 209 Po as a yield tracer. (author) 6 refs.; 5 tabs

  2. Experiences with large-area frisch grid chambers in low-level alpha spectrometry

    International Nuclear Information System (INIS)

    Hoetzl, H.; Winkler, R.

    1984-01-01

    The properties of parallel-plate gridded ionization chambers with areas of 300 cm 2 , developed by us for alpha spectrometry of samples with low specific alpha activity are reported. Several practical hints for optimum operating conditions are presented. The chambers can be operated routinely at atmospheric pressure for several days, without the need for purification of the gas filling (P10). The minimum detectable activity at 5 MeV is 0.01 pCi, based on 4.65 standard deviations of background and 1000 min counting time. At the GSF Research Center ionization chambers of this type are used for the analysis of natural alpha emitters, as well as of transuranium nuclides in environmental samples by: a) direct alpha spectrometry without any previous treatment of the sample, b) semi-direct spectrometry after removal of organic matter by low-temperature ashing and c) spectrometry after chemical separation. Some typical example of application are given. Furthermore the range of application of the chambers in comparison to semiconductor detectors in the field of low-level alpha spectrometry is discussed. (orig.)

  3. Radiometric dating by alpha spectrometry on uranium series nuclides

    NARCIS (Netherlands)

    Wijk, Albert van der

    1987-01-01

    De Engelse titel van dit proegschrift \\"Radiometric Dating by Alpha Spectometry on Uranium Series Nuclides\\" kan in het Nederlands wellicht het best worden weergegeven door \\"ouderdomsdbepalingen door stralingsmeting aan kernen uit de uraniumreeks met behulp van alfaspectometrie\\". In dit laatste

  4. Use of Peltier cells in high resolution alpha spectrometry

    International Nuclear Information System (INIS)

    Bueno, C.C.; Santos, M.D.S.; Goncalves, J.A.C.

    1994-01-01

    The experiments with low-cost commercial silicon PIN photodiodes have shown the possibility of their transformation for use as alpha detectors with performance comparable with surface barrier detectors which are more expensive. Utilizing the silicon photodiode with reverse bias, an energy resolution for 241 Am alpha particles of 28 KeV and 23 KeV were obtained at room temperature and at -30 0 C respectively. (author). 4 refs, 4 figs

  5. RAPID DETERMINATION OF 237 NP AND PU ISOTOPES IN WATER BY INDUCTIVELY COUPLED PLASMA MASS SPECTROMETRY AND ALPHA SPECTROMETRY

    Energy Technology Data Exchange (ETDEWEB)

    Maxwell, S.; Jones, V.; Culligan, B.; Nichols, S.; Noyes, G.

    2010-06-23

    A new method that allows rapid preconcentration and separation of plutonium and neptunium in water samples was developed for the measurement of {sup 237}Np and Pu isotopes by inductively-coupled plasma mass spectrometry (ICP-MS) and alpha spectrometry; a hybrid approach. {sup 238}U can interfere with {sup 239}Pu measurement by ICP-MS as {sup 238}UH{sup +} mass overlap and {sup 237}Np via peak tailing. The method provide enhanced removal of uranium by separating Pu and Np initially on TEVA Resin, then moving Pu to DGA resin for additional removal of uranium. The decontamination factor for uranium from Pu is almost 100,000 and the decontamination factor for U from Np is greater than 10,000. This method uses stacked extraction chromatography cartridges and vacuum box technology to facilitate rapid separations. Preconcentration is performed using a streamlined calcium phosphate precipitation method. Purified solutions are split between ICP-MS and alpha spectrometry so that long and short-lived Pu isotopes can be measured successfully. The method allows for simultaneous extraction of 20 samples (including QC samples) in 4 to 6 hours, and can also be used for emergency response. {sup 239}Pu, {sup 242}Pu and {sup 237}Np were measured by ICP-MS, while {sup 236}Pu, {sup 238}Pu, and {sup 239}Pu were measured by alpha spectrometry.

  6. Improved sample preparation method for environmental plutonium analysis by ICP-SFMS and alpha-spectrometry

    International Nuclear Information System (INIS)

    Varga, Z.; Stefanka, Z.; Suranyi, G.; Vajda, N.

    2007-01-01

    A rapid and simple sample preparation method for plutonium determination in environmental samples by inductively coupled plasma sector field mass spectrometry (ICP-SFMS) and alpha-spectrometry is described. The developed procedure involves a selective CaF 2 co-precipitation for preconcentration followed by extraction chromatographic separation. The proposed method effectively eliminates the possible interferences in mass spectrometric analysis and also removes interfering radionuclides that may disturb alpha-spectrometric measurement. For 239 Pu, 240 Pu and 241 Pu limits of detection of 9.0 fg x g -1 (0.021 mBq), 1.7 fg x g -1 (0.014 mBq) and 3.1 fg x g -1 (11.9 mBq) were achieved by ICP-SFMS, respectively, and 0.02 mBq by alpha-spectrometry. Results of certified reference materials agreed well with the recommended values. (author)

  7. A simple source preparation method for alpha-ray spectrometry of volcanic rock sample

    International Nuclear Information System (INIS)

    Takahashi, Masaomi; Kurihara, Yuichi; Sato, Jun

    2006-01-01

    A simple source preparation method was developed for the alpha-ray spectrometry to determine U and Th in volcanic rockes. Isolation of U and Th from volcanic rocks was made by use of UTEVA-Spec. resin, extraction chromatograph material. U and Th were extracted by TTA-benzene solution and organic phase was evaporated drop by drop on a hot stainless steel planchet to dryness. This method was found to be effective for the preparation of sources for alpha-ray spectrometry. (author)

  8. Problems and progress in the preparation of sources for the alpha spectrometry of plutonium

    International Nuclear Information System (INIS)

    Miguel, M.; Deron, S.; Swietly, H.; Heinonen, O.J.

    1981-01-01

    The interpretation of non-destructive measurements of plutonium materials require more accurate determinations of the isotopic abundance of Pu-238 than conventional chemical assays. The requirements of calorimetry, passive neutron and conventional chemical assays are presented and compared. When Pu-238 is measured by alpha spectrometry, these requirements define how well the plutonium must be separated from americium, and what should be the accuracy of the spectrometry. The latter can strongly depend upon the resolution of the alpha spectrum. The authors describe a procedure to produce sources by drop deposition which ensure a resolution of 17 keV with commercial instrumentation

  9. Rapid determination of actinides in urine by inductively coupled plasma mass spectrometry and alpha spectrometry: a hybrid approach.

    Science.gov (United States)

    Maxwell, Sherrod L; Jones, Vernon D

    2009-11-15

    A new rapid separation method that allows separation and preconcentration of actinides in urine samples was developed for the measurement of longer lived actinides by inductively coupled plasma mass spectrometry (ICP-MS) and short-lived actinides by alpha spectrometry; a hybrid approach. This method uses stacked extraction chromatography cartridges and vacuum box technology to facilitate rapid separations. Preconcentration, if required, is performed using a streamlined calcium phosphate precipitation. Similar technology has been applied to separate actinides prior to measurement by alpha spectrometry, but this new method has been developed with elution reagents now compatible with ICP-MS as well. Purified solutions are split between ICP-MS and alpha spectrometry so that long- and short-lived actinide isotopes can be measured successfully. The method allows for simultaneous extraction of 24 samples (including QC samples) in less than 3h. Simultaneous sample preparation can offer significant time savings over sequential sample preparation. For example, sequential sample preparation of 24 samples taking just 15 min each requires 6h to complete. The simplicity and speed of this new method makes it attractive for radiological emergency response. If preconcentration is applied, the method is applicable to larger sample aliquots for occupational exposures as well. The chemical recoveries are typically greater than 90%, in contrast to other reported methods using flow injection separation techniques for urine samples where plutonium yields were 70-80%. This method allows measurement of both long-lived and short-lived actinide isotopes. (239)Pu, (242)Pu, (237)Np, (243)Am, (234)U, (235)U and (238)U were measured by ICP-MS, while (236)Pu, (238)Pu, (239)Pu, (241)Am, (243)Am and (244)Cm were measured by alpha spectrometry. The method can also be adapted so that the separation of uranium isotopes for assay is not required, if uranium assay by direct dilution of the urine sample

  10. RAPID DETERMINATION OF ACTINIDES IN URINE BY INDUCTIVELY-COUPLED PLASMA MASS SPECTROMETRY AND ALPHA SPECTROMETRY: A HYBRID APPROACH

    Energy Technology Data Exchange (ETDEWEB)

    Maxwell, S.; Jones, V.

    2009-05-27

    A new rapid separation method that allows separation and preconcentration of actinides in urine samples was developed for the measurement of longer lived actinides by inductively coupled plasma mass spectrometry (ICP-MS) and short-lived actinides by alpha spectrometry; a hybrid approach. This method uses stacked extraction chromatography cartridges and vacuum box technology to facilitate rapid separations. Preconcentration, if required, is performed using a streamlined calcium phosphate precipitation. Similar technology has been applied to separate actinides prior to measurement by alpha spectrometry, but this new method has been developed with elution reagents now compatible with ICP-MS as well. Purified solutions are split between ICP-MS and alpha spectrometry so that long- and short-lived actinide isotopes can be measured successfully. The method allows for simultaneous extraction of 24 samples (including QC samples) in less than 3 h. Simultaneous sample preparation can offer significant time savings over sequential sample preparation. For example, sequential sample preparation of 24 samples taking just 15 min each requires 6 h to complete. The simplicity and speed of this new method makes it attractive for radiological emergency response. If preconcentration is applied, the method is applicable to larger sample aliquots for occupational exposures as well. The chemical recoveries are typically greater than 90%, in contrast to other reported methods using flow injection separation techniques for urine samples where plutonium yields were 70-80%. This method allows measurement of both long-lived and short-lived actinide isotopes. 239Pu, 242Pu, 237Np, 243Am, 234U, 235U and 238U were measured by ICP-MS, while 236Pu, 238Pu, 239Pu, 241Am, 243Am and 244Cm were measured by alpha spectrometry. The method can also be adapted so that the separation of uranium isotopes for assay is not required, if uranium assay by direct dilution of the urine sample is preferred instead

  11. Preparation of 237Np samples by electrodeposition and its determination by alpha spectrometry

    International Nuclear Information System (INIS)

    Mertzig, W.; Matsuda, H.T.; Araujo, B.F. de; Araujo, J.A. de

    1980-01-01

    An analytical method followed by alpha spectrometry was developed for the determination of trace amounts of actinides. A technique for quantitative electrodeposition of 237 Np, under optimal conditions, using a carrier, is presented. This method will be applied for the control of trace amounts of 237 Np in the solutions from the reprocessing (Purex process) of irradiated uranium. (C.L.B.) [pt

  12. Determination of ''226Ra by Alpha Spectrometry by Using ''225Ra as Yield Tracer

    International Nuclear Information System (INIS)

    Crespo, M. T.; Oller, O.

    1999-01-01

    A method for the determination of low-level ''226 Ra in environmental and geological samples by alpha spectrometry is described. The method is based on the use of ''225 Ra from ''229 Th as yield tracer and has been developed to analyze U, Th and Ra in the same sample. (Author) 12 refs

  13. Intercomparison of alpha and gamma spectrometry techniques used in (210)Pb geochronology.

    Science.gov (United States)

    Zaborska, Agata; Carroll, Jolynn; Papucci, Carlo; Pempkowiak, Janusz

    2007-01-01

    (210)Pb geochronology is a widely used tool in sedimentological studies aimed at the absolute ages of modern sediments (up to 100 years). (210)Pb activities required to model sedimentation regimes are measured using either alpha, gamma or beta spectrometry. Sediment accumulation rates derived from (210)Pb activity profiles measured by these methods are often used interchangeably in mass balance studies. Yet there is a lack of investigations considering the comparability of data derived using different analytical methods. Differences between methods could be caused by different behaviors of (210)Pb and (210)Po (used for alpha measurement) in the marine environment. In gamma spectrometry errors may arise when many gamma emitters are measured simultaneously and their activity peaks overlap. In alpha spectrometry chemical separation of (210)Po may result in analytical error due to incomplete sample dissolution. In the present study we evaluate total, supported and excess (210)Pb activities and their use in deriving sediment accumulation rates and (210)Pb excess inventories for three sediment cores collected from the Barents Sea. (210)Pb activities derived by alpha and gamma methods are shown to agree within counting error and there is also good agreement in the derived sediment accumulation rates. The inherent compatibility of analytical results based on alpha or gamma techniques is established.

  14. Ultra-high-resolution alpha spectrometry for nuclear forensics and safeguards applications

    International Nuclear Information System (INIS)

    Bacrania, Minesh K.; Croce, Mark; Bond, Evelyn; Dry, Donald; Moody, W. Allen; Lamont, Stephen; Rabin, Michael; Rim, Jung; Smith, Audrey; Beall, James; Bennett, Douglas; Kotsubo, Vincent; Horansky, Robert; Hilton, Gene; Schmidt, Daniel; Ullom, Joel; Cantor, Robin

    2010-01-01

    We will present our work on the development of ultra-high-resolution detectors for alpha particle spectrometry. These detectors, based on superconducting transition-edge sensors, offer energy resolution that is five to ten times better than conventional silicon detectors. Using these microcalorimeter detectors, the isotopic composition of mixed-actinide samples can be determined rapidly without the need for actinide separation chemistry to isolate each element, or mass spectrometry to separate isotopic signatures that can not be resolved using traditional alpha spectrometry (e.g. Pu-239/Pu-240, or Pu-238/Am-241). This paper will cover the detector and measurement system, actinide source preparation, and the quantitative isotopic analysis of a number of forensics- and safeguards-relevant radioactive sources.

  15. Determination of Uranium plus Plutonium by Alpha spectrometry in different matrix

    International Nuclear Information System (INIS)

    Equillor, Hugo E.; Campos, Juan M.

    2011-01-01

    Usually, the determination of alpha emitters by alpha spectrometry is performed with a prior purification of each of the elements to be quantified. In this work, a methodology for the determination of uranium and plutonium isotopes as jointly described, in order to improve analytical processing times and measurement. The method includes purifying uranium and plutonium, and the subsequent electrodeposition for alpha spectrometry measurement. The technique is based on the use of TBP (tributyl phosphate) as extractant and easy to obtain reactants. It is applicable to various matrices, including water, filters and soils. In the conditions described, is applied to small aliquots of approximately 0.5 g of solid. The technique produces high quality electrodeposits. (authors) [es

  16. Characterization of high level waste for minor actinides by chemical separation and alpha spectrometry

    International Nuclear Information System (INIS)

    Murali, M.S.; Bhattacharayya, A.; Kar, A.S.; Tomar, B.S.; Manchanda, V.K.

    2010-01-01

    Quantification of minor actinides present in of High Level Waste (HLW) solutions originating from the power reactors is important in view of management of radioactive wastes and actinide partitioning. Several methods such as ICP-MS, X-ray fluorescence methods, ICP-AES, alpha spectrometry are used in characterizing such types of wastes. As alpha spectrometry is simple and reliable, this technique has been used for the estimation of minor actinides after devising steps of separation for estimating Np and Pu present in HLW solutions of PHWR origin. Using a wealth of knowledge appropriate to the solution chemistry of actinides, the task of separation, though appears easy, it is challenging job for a radiochemist handling high-dose HLW samples, for obtaining clean alpha peaks for Np and Pu. This paper reports on the successful attempt made to quantify 241 Am, 244 Cm, Pu (239 mainly) and 237 Np present in HLW-PHWR obtained from PREFRE, Tarapur

  17. Determination of {sup 227}Ac by {alpha}-particle spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Martin, P. [Environmental Research Inst. of the Supervising Scientist, Jabiru, NT (Australia); Hancock, G.J. [Commonwealth Scientific and Industrial Research Organization, Canberra, ACT (Australia). Div. of Water Resources; Paulka, S. [Australian Radiation Lab., Yallambie, VIC (Australia); Akber, R.A. [Queensland Univ. of Technology, Brisbane, QLD (Australia)

    1995-10-01

    A method is described for the determination of {sup 227}Ac concentration in environmental samples. Actinium is separated from the sample digest by co-precipitation with lead sulphate, purified using anion and cation exchange techniques, and electrodeposited onto a stainless-steel disc. The chemical yield is monitored by addition of a {sup 229}Th/{sup 225}Ra/{sup 225}Ac tracer before sample dissolution. {sup 225}Ac recovery is determined from an initial count by measurement of its {alpha}-emitting daughter, {sup 217}At. The disc is then stored for 2-3 months and recounted. The {sup 227}Ac activity is obtained by measurement of the ingrown {sup 227}Th and {sup 223}Ra activities in the 5.38-6.10 MeV region. Co-precipitation with lead sulphate enables the convenient determination of actinium, thorium and radium on the same sample digest. (author).

  18. Radiometric dating by alpha spectrometry on uranium series nuclides

    International Nuclear Information System (INIS)

    Wijk, A. van der.

    1987-01-01

    This thesis describes the analytical and technical procedures that are required for routine application of both the 230 Th/ 234 U disequilibrium dating method for peat and the 210 Pb dating method for lake sediments. Its principal aim is to test, refine and discuss the reliability and validity of these methods. On the other hand, the analytical procedures that were introduced open a wide range of other interesting fields of research that are not necessarily restricted to geological problems only. Chapter 5 reports an obviously not foreseen application: detection of alpha emitting nuclides released in the first weeks of May, 1986 during the accident with the nuclear power plant in Chernobyl, USSR. 128 refs.; 43 figs.; 15 tabs

  19. Application of PERALS™ alpha spectrometry and gamma spectrometry for analysis and investigation of environmental spills at ISL uranium mining projects.

    Science.gov (United States)

    Borysenko, A; Ostrowski, A; Bellifemine, D; Palmer, G; Haigh, P; Johnston, A

    2014-03-01

    Radiation protection and environmental monitoring in mining requires effective and reliable radionuclide analysis at all stages of the mine project-prior to mining, during operation and through to remediation and decommissioning. The approach presented in this paper was specially developed for the monitoring of radioactive waste resulting from spills during mining and mineral processing operations and uses a combination of high resolution gamma spectrometry, and PERALS™ alpha spectrometry to identify and reliably quantify the activity of the major members of the U-238 decay chain at activities down to 10 mBq g(-1) by direct radionuclide counting and by assessment of the activity of their decay products. This approach has reduced sample preparation and analysis time while providing effective analysis and quantification of naturally occurring radionuclides in environmental samples. It has been successfully applied to several in situ leach (ISL) mining-related projects involving investigations of process material spill impacts and also to routine environmental monitoring.

  20. Determination of Uranium, Thorium and Radium 226 in Zircon containig sands by alpha spectrometry

    International Nuclear Information System (INIS)

    Spezzano, P.

    1985-01-01

    The industrial utilization of Zircon sands for the production of refractories presents radiological problems owing to the risk of inhalation of Uranium, Thorium and their decay products, present in high concentrations in such materials. A method of analysis was realized for the determination of Uranium, Thorium and Radium-226 in Zircon sands, including the total dissolution of the sample, radiochemical separation and final measurement by alpha spectrometry with surface barrier detector. The concentrations of the main alpha-emitting radionuclides presents in two samples of Zircon sands have been determined and the possibility of disequilibrium along the decay series has been pointed out

  1. Alpha spectrometry of thick sources. I. Application to alpha emitters determination

    International Nuclear Information System (INIS)

    Acena, M.L.; Garcia-Torano, E.; Rivero, M.C.

    1977-01-01

    A method for determining alpha emitters by silicon surface barrier detector spectroscopy using thick sources is studied. Two types of spectra have been obtained. They have different shapes of line according to the procedure used for preparing the sources. For both spectra a computing least square programme has been developed. In this way it is possible to calculate line intensities with accuracy better than 20 percent. (author) [es

  2. Proceedings of the International Symposium Advances in alpha, Beta- and Gamma-Ray spectrometry

    International Nuclear Information System (INIS)

    1997-01-01

    The International Committee for Radionuclide Metrology (ICRM) is an association of radionuclide metrology laboratories whose membership is composed of delegates of these laboratories together with other scientists actively engaged in the study and applications of radioactivity. The scientific activities are carried out in the frame of six Working Groups. Two of them, the Alpha-Particle Spectrometry and the Gamma-and Beta-ray Spectrometry Working Groups held a common workshop in Pushkin, St. Petersburg, 18 to 20 September 1996, under the title Advances in Alpha-Beta-and Gamma-Ray Sepectrometry, at the kind invitation of the D.I. Mendeleyev Institute for Metrology. More than 30 people from 14 laboratories attended the meeting, and nineteen oral communications were presented, from which twelve were retained for publication an are included in these proceedings. (Author)

  3. Standard test method for 238Pu isotopic abundance by alpha spectrometry

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2001-01-01

    1.1 This test method covers the use of alpha spectrometry for determining the 238Pu isotopic abundance in plutonium samples. It is particularly useful for samples in which the 238Pu content is less than 1 % of the total plutonium content. For such samples, mass spectrometric results are less reliable than those from alpha spectrometry because of interference from any 238U isobar remaining after ion exchange. 1.2 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

  4. Alpha spectrometry of thick sources. II. Application to the study of radioactive equilibria in uranium ores

    International Nuclear Information System (INIS)

    Acena Barrenechea, M.L.; Tormo Ferrero, M.J.

    1977-01-01

    A method for determining nuclide activities in 4n + 2 uranium series using alpha spectrometry of thick sources is described. This method has been applied to several uranium ores, showing different states of radioactive equilibria. The spectra from samples prepared by cold compression show some anomalies, due to the evolution and later decay of 219 Rn and daughters. This phenomenon must be taken in consideration when computing spectra line intensities. (author) [es

  5. Cryogenic microcalorimeter system for ultra-high resolution alpha-particle spectrometry

    International Nuclear Information System (INIS)

    Rabin, Michael W.; Hoover, Andrew S.; Bacrania, Minesh K.; Croce, Mark P.; Hoteling, N.J.; Lamont, S.P.; Plionis, A.A.; Dry, D.E.; Ullom, J.N.; Bennett, D.A.; Horansky, R.; Kotsubo, V.; Cantor, R.

    2009-01-01

    Microcalorimeters have been shown to yield unsurpassed energy resolution for alpha spectrometry, up to 1.06 keV FWHM at 5.3 MeV. These detectors use a superconducting transition-edge sensor (TES) to measure the temperature change in an absorber from energy deposited by an interacting alpha particle. Our system has four independent detectors mounted inside a liquid nitrogen/liquid helium cryostat. An adiabatic demagnetization refrigerator (ADR) cools the detector stage to its operating temperature of 80 mK. Temperature regulation with ∼15 uK peak-to-peak variation is achieved by PID control of the ADR. The detectors are voltage-biased, and the current signal is amplified by a commercial SQUID readout system and digitized for further analysis, This paper will discuss design and operation of our microcalorimeter alpha spectrometer, and will show recent results.

  6. Factors affecting the energy resolution in alpha particle spectrometry with silicon diodes

    International Nuclear Information System (INIS)

    Camargo, Fabio de.

    2005-01-01

    In this work are presented the studies about the response of a multi-structure guard rings silicon diode for detection and spectrometry of alpha particles. This ion-implanted diode (Al/p + /n/n + /Al) was processed out of 300 μm thick, n type substrate with a resistivity of 3 kΩ·cm and an active area of 4 mm 2 . In order to use this diode as a detector, the bias voltage was applied on the n + side, the first guard ring was grounded and the electrical signals were readout from the p + side. These signals were directly sent to a tailor made preamplifier, based on the hybrid circuit A250 (Amptek), followed by a conventional nuclear electronic. The results obtained with this system for the direct detection of alpha particles from 241 Am showed an excellent response stability with a high detection efficiency (≅ 100 %). The performance of this diode for alpha particle spectrometry was studied and it was prioritized the influence of the polarization voltage, the electronic noise, the temperature and the source-diode distance on the energy resolution. The results showed that the major contribution for the deterioration of this parameter is due to the diode dead layer thickness (1 μm). However, even at room temperature, the energy resolution (FWHM = 18.8 keV) measured for the 5485.6 MeV alpha particles ( 241 Am) is comparable to those obtained with ordinary silicon barrier detectors frequently used for these particles spectrometry. (author)

  7. Rapid determination of (237)Np and plutonium isotopes in urine by inductively-coupled plasma mass spectrometry and alpha spectrometry.

    Science.gov (United States)

    Maxwell, Sherrod L; Culligan, Brian K; Jones, Vernon D; Nichols, Sheldon T; Noyes, Gary W; Bernard, Maureen A

    2011-08-01

    A new rapid separation method was developed for the measurement of plutonium and neptunium in urine samples by inductively-coupled plasma mass spectrometry (ICP-MS) and/or alpha spectrometry with enhanced uranium removal. This method allows separation and preconcentration of plutonium and neptunium in urine samples using stacked extraction chromatography cartridges and vacuum box flow rates to facilitate rapid separations. There is an increasing need to develop faster analytical methods for emergency response samples. There is also enormous benefit to having rapid bioassay methods in the event that a nuclear worker has an uptake (puncture wound, etc.) to assess the magnitude of the uptake and guide efforts to mitigate dose (e.g., tissue excision and chelation therapy). This new method focuses only on the rapid separation of plutonium and neptunium with enhanced removal of uranium. For ICP-MS, purified solutions must have low salt content and low concentration of uranium due to spectral interference of (238)U(1)H(+) on m/z 239. Uranium removal using this method is enhanced by loading plutonium and neptunium initially onto TEVA resin, then moving plutonium to DGA resin where additional purification from uranium is performed with a decontamination factor of almost 1×10(5). If UTEVA resin is added to the separation scheme, a decontamination factor of ~3 × 10(6) can be achieved.

  8. RETROSPECTIVE METHOD VALIDATION AND UNCERTAINTY ESTIMATION FOR ACTINIDES DETERMINATION IN EXCRETA BY ALPHA SPECTROMETRY.

    Science.gov (United States)

    Hernández, C; Sierra, I

    2016-09-01

    Two essential technical requirements of ISO 17025 guide for accreditation of testing and calibration laboratories are the validation of methods and the estimation of all sources of uncertainty that may affect the analytical result. Bioelimination Laboratory from Radiation Dosimetry Service of CIEMAT (Spain) uses alpha spectrometry to quantify alpha emitters (Pu, Am, Th, U and Cm isotopes) in urine and faecal samples from workers exposed to internal radiation. Therefore and as a step previous to achieving the ISO 17025 accreditation, the laboratory has performed retrospective studies based on the obtained results in the past few years to validate the analytical method. Uncertainty estimation was done identifying and quantifying all the contributions, and finally the overall combined standard uncertainty was calculated. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  9. Sensitivity of ICP-MS, PERALS and alpha spectrometry for the determination of actinides

    International Nuclear Information System (INIS)

    Ayranov, M.; Krahenbiihl, U.; Rollin, S.; Burger, M.

    2004-01-01

    The purpose of this study was to compare the sensitivity of the three most popular techniques for the determination of minor actinides at environmental levels: ICP-MS, PERALS and solid state alpha spectrometry. For each method the limit of detection and the resolution were estimated in order to study the content and isotopic composition of the actinides. The sensitivities of the three determination techniques were compared. Two international reference materials, IAEA-135 (Irish Sea sediment) and IAEA-300 (Baltic Sea sediment) were analyzed for activity concentrations of 238 Pu, 239 Pu, 240 Pu, 241 Pu and 241 Am. (authors)

  10. The determination of radium-226 in uranium ores and mill products by alpha energy spectrometry

    International Nuclear Information System (INIS)

    Zimmerman, J.B.; Armstrong, V.C.

    1975-12-01

    A reliable routine procedure for determining 226 Ra by alpha energy spectrometry is described. Radium is isolated as sulphate from the sample matrix by co-precipitation with a small mass of barium and analysed using a ruggedized silicon surface barrier detector. The method is capable of providing high accuracy over a large 226 Ra concentration range and is applicable to materials such as uranium ores, uranium mill products and effluent streams. Samples resulting from nitric acid leach experiments with Elliot Lake ores were examined using the procedure. The distribution of 223 Ra, 224 Ra and 226 Ra between the leach products, (residue and leach liquor), is discussed. (author)

  11. Simulation study for high resolution alpha particle spectrometry with mesh type collimator

    International Nuclear Information System (INIS)

    Park, Seunghoon; Kwak, Sungwoo; Kang, Hanbyeol; Shin, Jungki; Park, Iljin

    2014-01-01

    An alpha particle spectrometry with a mesh type collimator plays a crucial role in identifying specific radionuclide in a radioactive source collected from the atmosphere or environment. The energy resolution is degraded without collimation because particles with a high angle have a longer path to travel in the air. Therefore, collision with the background increases. The collimator can cut out particles which traveling at a high angle. As a result, an energy distribution with high resolution can be obtained. Therefore, the mesh type collimator is simulated for high resolution alpha particle spectrometry. In conclusion, the collimator can improve resolution. With collimator, the collimator is a role of cutting out particles with a high angle, so, low energy tail and broadened energy distribution can be reduced. The mesh diameter is found out as an important factor to control resolution and counting efficiency. Therefore, a target particle, for example, 235 U, can be distinguished by a detector with a collimator under a mixture of various nuclides, for example: 232 U, 238 U, and 232 Th

  12. Rapid determination of radium-224/226 in seawater sample by alpha spectrometry.

    Science.gov (United States)

    Song, Lijuan; Yang, Yonggang; Luo, Maoyi; Ma, Yan; Dai, Xiongxin

    2017-05-01

    A new radiochemical separation method has been developed for rapid determination of alpha-emitting radium isotopes in seawater samples. This method can be applied for the measurement of 226 Ra in seawater samples when 224 Ra is used as tracer for chemical recovery correction. Likewise, 226 Ra can also be added as tracer for the determination of 224 Ra in seawater sample. In the method, radium is first pre-concentrated with hydrous titanium oxide (HTiO) and is purified by combined anion/cation exchange column chromatographic separation. The radium in the eluate is then co-precipitated with HTiO, dissolved in 9 M H 2 SO 4 , and followed through a BaSO 4 micro-precipitation step to prepare a thin-layer counting source to determine the activities of 224 Ra/ 226 Ra by alpha spectrometry. Replicate spike and blank samples were measured to evaluate the performance of the procedure. The minimum detectable activity concentration was determined to be 0.5 mBq·L -1 for 226 Ra and 0.4 mBq·L -1 for 224 Ra in 1 L of seawater sample with a counting time of 48 h. The method is a promising candidate for rapid measurement for alpha-emitting Ra isotopes in a large population of environment water samples. Copyright © 2017 Elsevier Ltd. All rights reserved.

  13. Uranium isotopes determination in urine samples using alpha spectrometry and ICP-MS

    Energy Technology Data Exchange (ETDEWEB)

    Rosa, Mychelle M.L.; Maihara, Vera A. [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Tine, Fernanda D.; Santos, Sandra M.C.; Bonifacio, Rodrigo L.; Taddei, Maria HelenaT. [Comissao Nacional de Energia Nuclear (LAPOC/CNEN-MG), Pocos de Caldas, MG (Brazil). Laboratorio de Pocos de Caldas

    2015-07-01

    The action of determining the concentration of uranium isotopes in biological samples, 'in vitro' bioassay, is an indirect method for evaluating the incorporation and quantification of these radionuclides internally deposited. When incorporated, these radionuclides tend to be disposed through excretion, with urine being the main source of data because it can be easily collected and analyzed. The most widely used methods for determination of uranium isotopes ({sup 234}U, {sup 235}U and {sup 238}U) are Alpha Spectrometry and ICP-MS. This work presents a comparative study for the determination of uranium isotopes using these two methodologies in real samples from occupationally exposed workers. In order to validate the methodology, a sample of the intercomparison exercise organized by PROCORAD (Association pour la Promotion du Controle de Qualite des Analyses de Biologie Medicale em Radiotoxicologie) was used, and the results were statistically compared applying the Student's t-test. (author)

  14. Standard practice for mounting actinides for alpha spectrometry using neodymium fluoride

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2008-01-01

    1.1 This practice covers the preparation of separated fractions of actinides for alpha spectrometry as an alternate to electrodeposition. It is applicable to any of the actinides that can be dissolved in dilute hydrochloric acid. Examples of applicable samples would be the final elution from an ion exchange separation or the final strip from a solvent extraction separation. 1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard. 1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. For a specific hazard statement, see Section 9.

  15. Standard test method for the radiochemical determination of americium-241 in soil by alpha spectrometry

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2007-01-01

    1.1 This method covers the determination of americium–241 in soil by means of chemical separations and alpha spectrometry. It is designed to analyze up to ten grams of soil or other sample matrices that contain up to 30 mg of combined rare earths. This method allows the determination of americium–241 concentrations from ambient levels to applicable standards. The values stated in SI units are to be regarded as standard. 1.2 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. For specific precaution statements, see Section 10.

  16. An improved method for determination of uranium isotopic composition in urine by alpha spectrometry

    International Nuclear Information System (INIS)

    Duarte, C.L.; Szeles, M.S.M.F.

    1994-01-01

    A comparative study of source preparation techniques to determine uranium isotopic composition by alpha spectrometry, namely electrodeposition and chemical stripping with polymeric membrane containing trioctylphosphine oxide (TOPO), is presented. The mean yield obtained for electrodeposition and TOPO deposition were 85% and 74%, respectively. The mean activity ratio 235 U/ 238 U were 0.044 and 0.042 and the ratio 234 U/ 238 U were 0.994 and 1.009, using electrodeposition and TOPO deposition techniques, respectively. The method of uranium separation from urine using an ion-exchange resin Dowex 1 x 8, chloride form and citrate form, was also studied. The obtained global yields of these methods were 50% and 41%, respectively. (author)

  17. Electrospray mass spectrometry characterization of post-translational modifications of barley alpha-amylase 1 produced in yeast

    DEFF Research Database (Denmark)

    Søgaard, M; Andersen, Jens S.; Roepstorff, P

    1993-01-01

    We have used electrospray mass spectrometry (ESMS) in combination with protein chemistry and genetics to delineate post-translational modifications in yeast of barley alpha-amylase 1 (AMY1), a 45 kD enzyme crucial for production of malt, an important starting material in the manufacture of beer...

  18. Determination of uranium and thorium isotopes by solid phase extraction and alpha spectrometry

    International Nuclear Information System (INIS)

    Kuruc, J.; Kovacova, M.; Strisovska, J.; Galanda, D.

    2013-01-01

    The aim of this work was to test the modified method suitable for the separation of isotopes of uranium and thorium samples of rocks, including gold ore and gold concentrate using of extraction chromatography method, after digestion of the sample, concentrating, separate the isotopes of uranium and thorium isotopes to prepare sources for the measurement of alpha spectra. Samples of rocks, gold ore and gold concentrate were digered in microwave decomposition in the environment of hydrogen peroxide and concentrated nitric acid. For the separation of uranium and thorium the vacuum box with cartridges DGA Resin and Resin(R) UTEVA (Triskem International, France) was used. Both sorbents allow separation of uranium from thorium. The results confirmed that the both sorbents give the same results within expanded uncertainty. The mass activity of monitored uranium and thorium radioisotopes was determined by alpha spectrometry method. The yields of separation were determined using uranium-232 as a tracer radionuclide; the activity of 232 U was 0.1438 Bq. Alpha spectra were measured on the Alpha spectrometer EG and G ORTEC 576A with the software MAESTRO, MCA Emulator and Gamma Vision-32 for Windows, USA. Mass activities of radionuclides were converted to mass concentration of isotopes 238 U, 234 U, 232 Th, 230 Th and 228 Th. The highest concentration of 238 U was sampled in granodiorite (Tunnel S-XIV-2, southwards, mining of Cu ore, not working there since 1990), where m( 238 U) = (0.81 ± 0.09) mg kg -1 (DGA Resin) and m( 238 U) = (0.90 ± 0.09) mg kg -1 (UTEVA(R) Resin), as well as m( 232 Th) = (18.8 ± 1.7) mg kg -1 (DGA Resin) and m( 232 Th) = (17.8 ± 1.5) mg kg -1 (UTEVA(R) Resin). In other samples of rocks, gold ore and gold concentrates have specific masses of isotopes of uranium and thorium two-to ten-folds lower. It can be concluded that the rocks, gold ores and concentrates of gold from the 'Rozalia' mine contain lower concentrations of uranium several times against

  19. Optimization of parameters of alpha spectrometry with silicon detector for low level measurements of actinides in environmental samples.

    Science.gov (United States)

    Rao, D D; Sudheendran, V; Sarkar, P K

    2012-08-01

    Determination of actinides in environmental and biological samples is an important activity of radiation protection program at nuclear energy facilities. High resolution alpha spectrometry with passivated ion implanted Silicon detectors is widely used for the determination of actinides concentration. Low levels of activity concentrations in these samples often require long counting duration of a few days to obtain accurate and statistically significant data for further impact assessment. In alpha spectrometry, the chamber in which Si detector operated is a critical component and maintained at a desired vacuum for minimizing the alpha particle attenuation. Experimental evaluation of variations in energy resolution and tailing of alpha spectra was investigated under different chamber air pressures from about 6.7 Pa to more than 2700 Pa under the chamber hold mode and pump electrically switched off conditions. As part of validation, data collected on an IAEA inter-comparison exercise sample are presented under short and long counting durations with pump operating and switched off conditions respectively. It has been observed that the FWHM values do not significantly degrade, to impact the low and medium level concentration alpha spectra, for variations in vacuum chamber pressures from about 6.7 Pa to 2700 Pa. Copyright © 2012 Elsevier Ltd. All rights reserved.

  20. A sequential extraction procedure to determine Ra and U isotopes by alpha-particle spectrometry in selective leachates

    International Nuclear Information System (INIS)

    Aguado, J.L.; Bolivar, J.P.; San-Miguel, E.G.; Garcia-Tenorio, R.

    2003-01-01

    A radiochemical sequential extraction procedure has been developed in our laboratory to determine 226 Ra and 234,238 U by alpha spectrometry in environmental samples. This method has been validated for both radionuclides by comparing in selected samples the values obtained through its application with the results obtained by applying alternative procedures. Recoveries obtained, counting periods applied and background levels found in the alpha spectra give suitable detection limits to allow the Ra and U determination in operational forms defined in riverbed contaminated sediments. Results obtained in these speciation studies show that 226 Ra and 234,238 U contamination tend to be associated to precipitated forms of the sediments. (author)

  1. Determination of uranium and polonium in Spa rus aura ta by alpha spectrometry

    International Nuclear Information System (INIS)

    Luna P, M.; Renteria, M.; Montero C, M. E.; Manjon C, G.; Diaz, I.

    2012-01-01

    The aim of this study was optimizing conditions for the specific activities determination of some uranium-series radionuclides present in Spa rus aura ta by alpha spectrometry. Determinations of specific activities were conducted varying the type of digestion: acid attack on hot plate, controlled microwave digestion and acid attack after calcination of the sample. The latter procedure was applied only to the case of uranium isotopes determination. The variation in the isotope extraction method consisted of applying the techniques of liquid-liquid extracting using Tributyl phosphate or chromatographic UTEVA resin. Results depending on the type of treatment given to the samples were compared based on obtained chemical yields. The results reveal a higher bioaccumulation of polonium in the liver sample, with activities of 0.809, 2.495 and 2.439 Bq kg -1 fresh wt compared with the fillet. The best chemical yields of polonium were close to 60% for samples that were digested by microwave. In the case of uranium the best chemical yields, close to 80% for fillet, were obtained with a previous calcination of the sample and using the UTEVA resin. (Author)

  2. Aerosols in King George Island (Antarctic peninsula) using PIXE and alpha spectrometry

    International Nuclear Information System (INIS)

    Dias da Cunha, K.; Medeiros, G.; Leal, M.A.; Lima, C.; Dalia, K.C.

    2009-01-01

    The aim of this study was to characterize the airborne particles and particles deposited in the recent snow samples collected at King George Island (Admiralty Bay) in order to evaluate the possible local sources of airborne particles and the aerosol transport from South America to Antarctic at sea level. Airborne particles samples were collected using a cascade impactor and cyclones at several sampling points at Admiralty Bay. Airborne particles were also collected during the ship travel from Rio de Janeiro to Antarctica. The recent snow samples and aerosols collected at several sampling points at Admiralty Bay were analyzed by PIXE for the determination of the elemental mass concentration. Snow samples were analyzed by alpha spectrometry to determine the 232Th, 228Th, 238U and 234U concentrations in snow. The Mass Median Aerodynamic Diameter of airborne particles was determined. The results suggest that there is a correlation between the aerosol samples and the particles deposited in the snow, but the elemental mass distributions are not equal. The snow elemental concentration can be used as an indicator of the elements present in the aerosols. The local aerosol sources (natural and anthropogenic) have been considered to characterize the aerosol transport to Antarctic, mainly King George Island. The main aerosol sources are the marine spray, weathering of local rocks and anthropogenic sources, as the diesel burning in the island. Besides the local aerosol sources the transport of airborne particles from south Atlantic to Antarctic is an important source of airborne particles at King George Island. (author)

  3. Determination of uranium and polonium in Spa rus aura ta by alpha spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Luna P, M.; Renteria, M.; Montero C, M. E. [Centro de Investigacion en Materiales Avanzados, S. C., Miguel de Cervantes No. 120, Complejo Industrial Chihuahua, 31109 Chihuahua (Mexico); Manjon C, G.; Diaz, I., E-mail: elena.montero@cimav.edu.mx [Universidad de Sevilla, Escuela Tecnica Superior de Arquitectura, Departamento de Fisica Aplicada II, San Fernando No. 4, 41004 Sevilla (Spain)

    2012-06-15

    The aim of this study was optimizing conditions for the specific activities determination of some uranium-series radionuclides present in Spa rus aura ta by alpha spectrometry. Determinations of specific activities were conducted varying the type of digestion: acid attack on hot plate, controlled microwave digestion and acid attack after calcination of the sample. The latter procedure was applied only to the case of uranium isotopes determination. The variation in the isotope extraction method consisted of applying the techniques of liquid-liquid extracting using Tributyl phosphate or chromatographic UTEVA resin. Results depending on the type of treatment given to the samples were compared based on obtained chemical yields. The results reveal a higher bioaccumulation of polonium in the liver sample, with activities of 0.809, 2.495 and 2.439 Bq kg{sup -1} fresh wt compared with the fillet. The best chemical yields of polonium were close to 60% for samples that were digested by microwave. In the case of uranium the best chemical yields, close to 80% for fillet, were obtained with a previous calcination of the sample and using the UTEVA resin. (Author)

  4. Alpha and gamma spectrometry for natural radioactive nuclides around uranium mines and nuclear power plants

    Energy Technology Data Exchange (ETDEWEB)

    Sanchez, A.M.; Tome, F.V.; Bejarano, J.D.; Aparicio, A.G. (Universidad de Extremadura, Badajoz (Spain). Dept. de Fisica)

    1992-01-01

    Concentration of uranium and [sup 234]U/[sup 238]U and [sup 235]U/[sup 238]U activity ratios were studied in water samples taken in the neighbourhood of two uranium mines ('El Lobo' and 'El Pedregal', Badajoz, Spain), and around two nuclear power plants and their cooling reservoirs (the Central Nuclear de Almaraz, which is working today, and the Central Nuclear de Valdecaballeros, which is in the construction phase), using alpha spectrometry with semiconductor detectors. The Valdecaballeros data were taken to check for comparison with those of the Central Nuclear de Almaraz and with future values after the start of operation. Measurements were also made of all soluble gamma emitting nuclides using a shielded coaxial high purity germanium detector. The data suggest that the mechanisms responsible for the changes in the concentrations and in the [sup 234]U/[sup 238]U activity ratios in surface waters are principally dilution and leaching. (author).

  5. Interaction between alpha and upsilon-crystallin, common to the eye of the Australian platypus, by radical probe mass spectrometry.

    Science.gov (United States)

    Issa, Samah; Downard, Kevin M

    2006-10-01

    The interaction between alpha-crystallin and upsilon-crystallin, a class recently discovered in the eye of the Australian platypus, has been shown by native shift gel assay and examined by radical probe mass spectrometry in the context of the ability of alpha-crystallin to protect upsilon-crystallin from oxidation and oxidative damage through radical-based oxidative stress mechanisms. Residues 22-41, 132-148, 212-227 and 245-264 of upsilon-crystallin display the greatest protection when interacted with alpha-crystallin at a ratio of 2 : 1 observed for the complex, which is commensurate with their levels measured in the eye of the platypus. Across each domain, a delay in the onset of oxidative damage is observed as the time of exposure to radicals is increased. The results are discussed in the context of the structure of the porcine homologue of upsilon-crystallin. Copyright 2006 John Wiley & Sons, Ltd.

  6. Concentration of Radon Progeny in Air by Alpha Spectrometry Measurement; Medida de los descendientes del radon en aire por Espectrometria Alfa

    Energy Technology Data Exchange (ETDEWEB)

    Acena, M. L.; Crespo, M. T.

    1989-07-01

    The concentration of radon progeny in air has been determined by alpha spectrometry measurement of 214 Po and 318 Po. A known volume of air was passed through a filter, then the alpha activity was directly measured on this filter. (Author) 15 refs.

  7. Comparison of analytical methods used to determine 235U, 238U and 210Pb from sediment samples by alpha, beta and gamma spectrometry

    International Nuclear Information System (INIS)

    Vesterbacka, P.; Klemola, S.; Salahel-Din, K.

    2009-01-01

    An intercomparison of the methodology (alpha, beta and gamma spectrometry) used for 238 U, 235 U and 210 Pb determination was carried out based on 38 sediment samples. The activity range of the samples varied from 10-700 Bq/kg for 210 Pb, 1-35 Bq/kg for 235 U and 10-800 Bq/ kg for 238 U. Results obtained using the three methods were not statistically different at high activity levels, but agreement between the results decreased at lower sample activity levels. For 210 Pb, the smallest difference was found between alpha and gamma spectrometry. A good correlation between results from alpha and gamma spectrometry was observed over the whole activity range. In beta spectrometry, the results were slightly higher than those obtained by alpha or gamma spectrometry due to the impurity of 228 Ra. In 238 U analysis, good correspondence was observed between 238 U determined by gamma and alpha spectrometry, particularly at higher 238 U activity concentrations over 100 Bq/kg. In 235 U analysis, attention needs to be paid to interference from 226 Ra and its reduction. (author)

  8. Measurement of electro-sprayed 238 and 239+240 plutonium isotopes using 4π-alpha spectrometry. Application to environmental samples

    International Nuclear Information System (INIS)

    Charmoille-Roblot, M.

    1999-01-01

    A new protocol for plutonium deposition using the electro-spray technique coupled with 4π-α spectrometry is proposed to improve the detection limit, shorten the counting time. In order to increase the detection efficiency, it was proposed to measure 238 and 239+240 plutonium isotopes electro-sprayed deposit simultaneously on both sides of the source support, that must be as transparent as possible to alpha-emissions, in a two-alpha detectors chamber. A radiochemical protocol was adapted to electro-spray constraints and a very thin carbon foil was selected for 4π -alpha spectrometry. The method was applied to a batch of sediment samples and gave the same results as an electrodeposited source measured using conventional alpha spectrometry with a 25 % gain on counting time and 10 % on plutonium 238 detection limit. Validation and application of the technique have been made on reference samples. (author)

  9. Determination of 210Pb by direct gamma-ray spectrometry, beta counting via 210Bi and alpha-particle spectrometry via 210Po in coal, slag and ash samples from thermal power plant

    International Nuclear Information System (INIS)

    Seslak, Bojan; Vukanac, Ivana; Kandic, Aleksandar; Durasevic, Mirjana; Eric, Milic; Jevremovic, Aleksandar

    2017-01-01

    In order to compare three different techniques and estimate radiological impact, activity concentration of 210 Pb in coal, slag and ash samples from thermal power plant 'Nikola Tesla', Serbia, were measured, and results are presented in this study. Determination of 210 Pb was carried out in three ways: using HPGe gamma spectrometer and via in-growth of 210 Po and 210 Bi by alpha-particle spectrometry and proportional counting, respectively. The results obtained for three different techniques were compared. Statistical analysis and comparison of methods were carried out by combination of Z score and χ 2 statistical tests. Tests results, as well as values of measured activities concentrations obtained by alpha and gamma spectrometry, showed that gamma spectrometry is a valid alternative to time-consuming alpha spectrometry for low level activity measurements of 210 Pb. This remark is also valid even for gamma spectrometers with poor efficiency in low energy region. (author)

  10. Preparation of large-area sources with uniform layers for the spectrometry of alpha-emitting nuclides

    International Nuclear Information System (INIS)

    Biehl, R.; Paschke, M.; Pilwat, G.

    1999-01-01

    A procedure for the preparation of large-area sources with uniform layers for α-spectrometry for the large-area grid ionization chamber has been developed. It is based on the direct evaporation of a sample solution in the counting dish in the presence of an excess of a sublimable chemical compound like ammonium nitrate. In the course of evaporation this excess compound precipitates and thus avoids the formation of clusters during the further evaporation process. After dryness, the excess compound is removed from the source by sublimation. Samarium nitrate is added as an internal standard and the alpha-activity of the isotope 147 Sm is chosen to measure the counting efficiency due to self-absorption. Examples are presented of the application of large-area sources for α-spectrometry for the large-area grid ionization chamber. (author)

  11. Trace uranium analysis in geological sample by isotope dilution-alpha spectrometry and comparison with other techniques

    International Nuclear Information System (INIS)

    Shihomatsu, H.M.; Iyer, S.S.

    1988-12-01

    Establishment of uranium determination in geological samples by alpha spectrometric isotope dilution technique using 233 U tracer is described in the present work. The various steps involved in the method namely, preparation of the sample, electrodeposition, alpha spectrometry, isotope dilution, calculation of the concentration and error statistics are discussed in detail. The experimental parameters for the electrodeposition of uranium, like current density, pH concentration of the electrolyte solution, deposition time, electrode distance were all optimised based on the efficiency of the deposition. The total accuracy and precision of the IDAS using 233 U tracer in the determination of uranium in mineral and granite samples were of the order of 1 to 2% for the concentration range of 50-1500 ppm of U. Our results are compared with those obtained by others workers using similar and different techniques. (author) [pt

  12. Secondary ion mass spectrometry combined with alpha track detection for isotope abundance ratio analysis of individual uranium-bearing particles.

    Science.gov (United States)

    Esaka, Fumitaka; Magara, Masaaki

    2014-03-01

    Secondary ion mass spectrometry (SIMS) was used in combination with alpha track detection for the efficient analysis of uranium-bearing particles with higher (235)U abundances in environmental samples. A polycarbonate film containing particles was prepared and placed in contact with a CR-39 plastic detector. After exposure for 28 days, the detector was etched in a NaOH solution and each uranium-bearing particle was identified through observation of the alpha tracks recorded in the detector. A portion of the film containing each uranium-bearing particle was cut out and put onto a glassy carbon planchet. The films on the planchet were decomposed through plasma ashing for subsequent uranium abundance ratio analysis with SIMS. The alpha track-SIMS analysis of 10 uranium-bearing particles in a sample taken from a nuclear facility enabled n((235)U)/n((238)U) abundance ratios in the range 0.0072-0.25 to be detected, which were significantly higher than those obtained by SIMS without alpha track detection. The duration of the whole analytical process for analysis of 10 particles was about 32 days. The detection efficiency was calculated to be 27.1±6.5%, based on the analysis of the particles in uranium reference materials. The detection limits, defined as the diameter of the particle which produces alpha tracks more than one for a 28-days exposure, were estimated to be 0.8, 0.9, 1.1, 2.1 and 3.0 μm for the particles having the same uranium abundance ratios with NBL CRM U850, U500, U350, U050 and U010 reference materials, respectively. The use of alpha track detection for subsequent SIMS analysis is an inexpensive and an efficient way to measure uranium-bearing particles with higher (235)U abundances. Copyright © 2013 Elsevier B.V. All rights reserved.

  13. DETERMINATION OF MUSHROOM TOXIN ALPHA-AMANITIN IN SERUM BY LIQUID CHROMATOGRAPHY-MASS SPECTROMETRY AFTER SOLID-PHASE EXTRACTION

    Directory of Open Access Journals (Sweden)

    Maja Vujović

    2015-03-01

    Full Text Available Alpha-amanitin is a cyclic peptide which belongs to a large group of mushroom toxins known as amatoxins. Being responsible for the majority of fatal mushroom poisonings, they require rapid detection and excretion from the body fluids. In accordance with these requirements, a simple and an accurate method was developed for successful identification and quantification of alpha-amanitin in serum with electrospray liquid chromatography–mass spectrometry (LC-ESI-MS after collision-induced dissociation. The method conforms to the established International Conference on Harmonization Q2A/Q2B 1996 guidelines on the validation of analytical methods. Linearity, precision, extraction recovery and stability test on blank serum spiked with alpha-amanitin and stored in different conditions met the acceptance criteria. The obtained calibration curve was linear over the concentration range 5-100 ng/mL with a lower limit of quantification (LOQ of 5 ng/mL and limit of detection (LOD of 2.5 ng/mL. The mean intra- and inter-day precision and accuracy were 6.05% and less than ±15% of nominal values, respectively. The neutral solid phase extraction with copolymer hydrophilic–lipophilic balance cartridges was found optimal for sample preparation with the mean recovery of 91.94%. The proposed method demonstrated high sensitivity and selectivity which can be useful both for clinical and forensic toxicology analysis of alpha-amanitin at low concentrations.

  14. Alternate method of source preparation for alpha spectrometry: no electrodeposition, no hydrofluoric acid

    International Nuclear Information System (INIS)

    Hiromu Kurosaki; Lambert, S.B.; Rao, G.R.; Mueller, R.J.

    2017-01-01

    An alternate method of preparing actinide alpha counting sources was developed in place of electrodeposition or lanthanide fluoride micro-precipitation. The method uses lanthanide hydroxide micro-precipitation to avoid the use of hazardous hydrofluoric acid. It provides a quicker, simpler, and safer way of preparing actinide alpha counting sources in routine, production-type laboratories that process many samples daily. (author)

  15. Alternate method of source preparation for alpha spectrometry: No electrodeposition, no hydrofluoric acid

    International Nuclear Information System (INIS)

    Kurosaki, Hiromu; Mueller, Rebecca J.; Lambert, Susan B.; Rao, Govind R.

    2016-01-01

    An alternate method of preparing actinide alpha counting sources was developed in place of electrodeposition or lanthanide fluoride micro-precipitation. The method uses lanthanide hydroxide micro-precipitation to avoid the use of hazardous hydrofluoric acid. Lastly, it provides a quicker, simpler, and safer way of preparing actinide alpha counting sources in routine, production-type laboratories that process many samples daily.

  16. Comparative determination of uranium in rock phosphates and columbite by ICP-OES, alpha and gamma spectrometry

    International Nuclear Information System (INIS)

    Singhal, R.K.; Sharma, P.K.; Bassan, M.K.T.; Basu, H.; Reddy, A.V.R.

    2011-01-01

    During this work selective separation of uranium from rock phosphate and columbite mineral was done before its quantitative estimation by using Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES). Uranium from the rock phosphate and columbite was extracted by sodium peroxide fusion followed by leaching in 2 M HNO 3 . To avoid spectral interference in the estimation of uranium by ICP-OES, the selective separation of uranium from the leachate was carried out by using two different extractants, 30% Tributyl Phosphates (TBP) in CCl 4 and a equi-volume mixture of Di(2-ethylhexyl) phosphoric acid (D2EHPA) and TBP in petrofin. Uranium was stripped from the organic phase by using 1 M ammonium carbonate solution. Determination of uranium by ICP-OES was done after dissolving the residue left after evaporation of ammonium carbonate solution in 4% HNO 3 . The concentration of the uranium observed in the rock phosphates samples was 40-200 μg g -1 whereas in columbite samples the concentration range was 100-600 μg g -1 . Uranium concentration evaluated by ICP-OES was complimented by gamma and alpha spectrometry. Concentration of uranium evaluated by gamma spectrometry in case of rock phosphate and columbite was in close agreement with the uranium content obtained by ICP-OES. Uranium determination by alpha spectrometry showed only minor deviation (1-2%) from the results obtained by ICP-OES in case of rock phosphates whereas in case of columbites results are off by 20-30%. (author)

  17. Chemical vapor deposition (CVD) of uranium for alpha spectrometry; Deposicion quimica de vapor (CVD) de uranio para espectrometria alfa

    Energy Technology Data Exchange (ETDEWEB)

    Ramirez V, M. L.; Rios M, C.; Ramirez O, J.; Davila R, J. I.; Mireles G, F., E-mail: luisalawliet@gmail.com [Universidad Autonoma de Zacatecas, Unidad Academica de Estudios Nucleares, Cipres No. 10, Fracc. La Penuela, 98068 Zacatecas (Mexico)

    2015-09-15

    The uranium determination through radiometric techniques as alpha spectrometry requires for its proper analysis, preparation methods of the source to analyze and procedures for the deposit of this on a surface or substrate. Given the characteristics of alpha particles (small penetration distance and great loss of energy during their journey or its interaction with the matter), is important to ensure that the prepared sources are thin, to avoid problems of self-absorption. The routine methods used for this are the cathodic electro deposition and the direct evaporation, among others. In this paper the use of technique of chemical vapor deposition (CVD) for the preparation of uranium sources is investigated; because by this, is possible to obtain thin films (much thinner than those resulting from electro deposition or evaporation) on a substrate and comprises reacting a precursor with a gas, which in turn serves as a carrier of the reaction products to achieve deposition. Preliminary results of the chemical vapor deposition of uranium are presented, synthesizing and using as precursor molecule the uranyl acetylacetonate, using oxygen as carrier gas for the deposition reaction on a glass substrate. The uranium films obtained were found suitable for alpha spectrometry. The variables taken into account were the precursor sublimation temperatures and deposition temperature, the reaction time and the type and flow of carrier gas. Of the investigated conditions, two depositions with encouraging results that can serve as reference for further work to improve the technique presented here were selected. Alpha spectra obtained for these depositions and the characterization of the representative samples by scanning electron microscopy and X-ray diffraction are also presented. (Author)

  18. Measurement of electro-sprayed 238 and 239+240 plutonium isotopes using 4{pi}-alpha spectrometry. Application to environmental samples; Spectrometrie alpha 4{pi} de sources d'actinides realisees par electronebulisation. Developpement et optimisation d'un protocole applique au mesurage des isotopes 238 et 239+240 du plutonium dans l'environnement

    Energy Technology Data Exchange (ETDEWEB)

    Charmoille-Roblot, M. [CEA/Fontenay-aux-Roses, Dept. de Protection de l' Environnement (DPRE), 92 (France)]|[Paris-11 Univ., 91 - Orsay (France)

    1999-07-01

    A new protocol for plutonium deposition using the electro-spray technique coupled with 4{pi}-{alpha} spectrometry is proposed to improve the detection limit, shorten the counting time. In order to increase the detection efficiency, it was proposed to measure 238 and 239+240 plutonium isotopes electro-sprayed deposit simultaneously on both sides of the source support, that must be as transparent as possible to alpha-emissions, in a two-alpha detectors chamber. A radiochemical protocol was adapted to electro-spray constraints and a very thin carbon foil was selected for 4{pi} -alpha spectrometry. The method was applied to a batch of sediment samples and gave the same results as an electrodeposited source measured using conventional alpha spectrometry with a 25 % gain on counting time and 10 % on plutonium 238 detection limit. Validation and application of the technique have been made on reference samples. (author)

  19. Phosphoinositide binding regulates alpha-actinin CH2 domain structure: analysis by hydrogen/deuterium exchange mass spectrometry.

    Science.gov (United States)

    Full, Stephen J; Deinzer, Max L; Ho, P Shing; Greenwood, Jeffrey A

    2007-12-01

    alpha-Actinin is an actin bundling protein that regulates cell adhesion by directly linking actin filaments to integrin adhesion receptors. Phosphatidylinositol (4,5)-diphosphate (PtdIns (4,5)-P(2)) and phosphatidylinositol (3,4,5)-triphosphate (PtdIns (3,4,5)-P(3)) bind to the calponin homology 2 domain of alpha-actinin, regulating its interactions with actin filaments and integrin receptors. In this study, we examine the mechanism by which phosphoinositide binding regulates alpha-actinin function using mass spectrometry to monitor hydrogen-deuterium (H/D) exchange within the calponin homology 2 domain. The overall level of H/D exchange for the entire protein showed that PtdIns (3,4,5)-P(3) binding alters the structure of the calponin homology 2 domain increasing deuterium incorporation, whereas PtdIns (4,5)-P(2) induces changes in the structure decreasing deuterium incorporation. Analysis of peptic fragments from the calponin homology 2 domain showed decreased local H/D exchange within the loop region preceding helix F with both phosphoinositides. However, the binding of PtdIns (3,4,5)-P(3) also induced increased exchange within helix E. This suggests that the phosphate groups on the fourth and fifth position of the inositol head group of the phosphoinositides constrict the calponin homology 2 domain, thereby altering the orientation of actin binding sequence 3 and decreasing the affinity of alpha-actinin for filamentous actin. In contrast, the phosphate group on the third position of the inositol head group of PtdIns (3,4,5)-P(3) perturbs the calponin homology 2 domain, altering the interaction between the N and C terminus of the full-length alpha-actinin antiparallel homodimer, thereby disrupting bundling activity and interaction with integrin receptors.

  20. Nuclear Track Detector Characterization via Alpha-Spectrometry for Radioprotection Use

    Energy Technology Data Exchange (ETDEWEB)

    Morelli, D.; Imme, G.; Catalano, R. [Dipartimento di Fisica e Astronomia, Universita degli Studi di Catania, via S. Sofia, 64- 95123 Catania (Italy); Istituto Nazionale di Fisica Nucleare - Sezione di Catania, via S. Sofia, 64- 95123 Catania (Italy); Aranzulla, M. [Istituto Nazionale Geofisica e Vulcanologia - Sezione di Catania, piazza Roma, 2- 95127 Catania (Italy); Tazzer, A. L. Rosselli; Mangano, G. [Dipartimento di Fisica e Astronomia, Universita degli Studi di Catania, via S. Sofia, 64- 95123 Catania (Italy)

    2011-12-13

    Solid Nuclear Track Detectors (SNTDs), CR-39 type, are usually adopted to monitor radon gas concentrations. In order to characterize the detectors according to track geometrical parameters, detectors were irradiated inside a vacuum chamber by alpha particles at twelve energy values, obtained by different Mylar foils in front of a {sup 241}Am source. The alpha energy values were verified using a Si detector. After the exposure to the alpha particles, the detectors were chemically etched to enlarge the tracks, which were then analyzed by means of a semiautomatic system composed of an optical microscope equipped with a CCD camera connected to a personal computer to store images. A suitable routine analyzed the track parameters: major and minor axis length and mean grey level, allowing us to differentiate tracks according to the incident alpha energy and then to individuate the discrimination factors for radon alpha tracks. The combined use of geometrical and optical parameters allows one to overcome the ambiguity in the alpha energy determination due to the non-monotonicity of each parameter versus energy. After track parameter determination, a calibration procedure was performed by means of a radon chamber. The calibration was verified through an inter-comparing survey.

  1. Analysis of zearalenone and alpha-zearalenol in urine of ruminants using gas chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Plasencia, J; Mirocha, C J; Pawlosky, R J; Smith, J F

    1990-01-01

    The present paper describes a sensitive procedure for quantitative analysis of the Fusarium mycotoxins zearalenone and alpha-zearalenol in urine of ruminants. Extraction is done with an octadecyl (C18) column and cleanup with a silica column providing a preparation that is analyzed by gas chromatography-tandem mass spectrometry (GC-MS/MS). The trimethylsilyl ether derivatives of zearalenone and alpha-zearalenol yield molecular ions with m/z 462 and 536, respectively. These ions are selected in the first mass analyzer and then fragmented in a collision cell to give characteristic daughter ions (m/z 151, 333, 318, and 446). The method is known as multiple reaction monitoring (MRM). Elimination of chemical background noise by selecting proper fragment ions produces chromatograms in which identification and quantitation in a biological matrix is possible. The method was tested with sheep urine from an experimental feeding trial and was used to confirm natural mycotoxicosis of cows affected with zearalenone. Zearalenone (1 ppb) and alpha-zearalenol (14 ppb) were found in 2 different cow urine samples. The detection limit for both zearalenone and zearalenol is 1 ppb (1 ng/mL) in urine and is linear between 1 and 20 ppb for the former and 1 and 10 ppb for the latter.

  2. Functional unfolding of alpha1-antitrypsin probed by hydrogen-deuterium exchange coupled with mass spectrometry.

    Science.gov (United States)

    Baek, Je-Hyun; Yang, Won Suk; Lee, Cheolju; Yu, Myeong-Hee

    2009-05-01

    The native state of alpha(1)-antitrypsin (alpha(1)AT), a member of the serine protease inhibitor (serpin) family, is considered a kinetically trapped folding intermediate that converts to a more stable form upon complex formation with a target protease. Although previous structural and mutational studies of alpha(1)AT revealed the structural basis of the native strain and the kinetic trap, the mechanism of how the native molecule overcomes the kinetic barrier to reach the final stable conformation during complex formation remains unknown. We hypothesized that during complex formation, a substantial portion of the molecule undergoes unfolding, which we dubbed functional unfolding. Hydrogen-deuterium exchange coupled with ESI-MS was used to analyze this serpin in three forms: native, complexing, and complexed with bovine beta-trypsin. Comparing the deuterium content at the corresponding regions of these three samples, we probed the unfolding of alpha(1)AT during complex formation. A substantial portion of the alpha(1)AT molecule unfolded transiently during complex formation, including not only the regions expected from previous structural studies, such as the reactive site loop, helix F, and the following loop, but also regions not predicted previously, such as helix A, strand 6 of beta-sheet B, and the N terminus. Such unfolding of the native interactions may elevate the free energy level of the kinetically trapped native serpin sufficiently to cross the transition state during complex formation. In the current study, we provide evidence that protein unfolding has to accompany functional execution of the protein molecule.

  3. Identification of a Rare Hemoglobin Variant HbJ-Rajappen [alpha90 (FG2) Lys → Thr] Using Mass Spectrometry.

    Science.gov (United States)

    Bhat, Vijay S; Mandal, Amit Kumar; Mathew, Bobby

    2012-10-01

    Hemoglobin J-Rajappen (alpha)90 Lys → Thr is an alpha chain variant found in heterozygous state and presents normal hematological blood picture. Due to the ambiguity in results obtained while analyzing by HPLC and alkaline gel electrophoresis, we report this rare case of HbJ-Rajappen using non denaturing gel electrophoresis and matrix assisted laser desorption ionization mass spectrometry. Though HbJ-Rajappen has earlier been reported using different techniques, this is the first report being validated using mass spectrometry technique.

  4. Differentiation of Boc-protected alpha,delta-/delta,alpha- and beta,delta-/delta,beta-hybrid peptide positional isomers by electrospray ionization tandem mass spectrometry.

    Science.gov (United States)

    Raju, G; Ramesh, V; Srinivas, R; Sharma, G V M; Shoban Babu, B

    2010-06-01

    Two new series of Boc-N-alpha,delta-/delta,alpha- and beta,delta-/delta,beta-hybrid peptides containing repeats of L-Ala-delta(5)-Caa/delta(5)-Caa-L-Ala and beta(3)-Caa-delta(5)-Caa/delta(5)-Caa-beta(3)-Caa (L-Ala = L-alanine, Caa = C-linked carbo amino acid derived from D-xylose) have been differentiated by both positive and negative ion electrospray ionization (ESI) ion trap tandem mass spectrometry (MS/MS). MS(n) spectra of protonated isomeric peptides produce characteristic fragmentation involving the peptide backbone, the Boc-group, and the side chain. The dipeptide positional isomers are differentiated by the collision-induced dissociation (CID) of the protonated peptides. The loss of 2-methylprop-1-ene is more pronounced for Boc-NH-L-Ala-delta-Caa-OCH(3) (1), whereas it is totally absent for its positional isomer Boc-NH-delta-Caa-L-Ala-OCH(3) (7), instead it shows significant loss of t-butanol. On the other hand, second isomeric pair shows significant loss of t-butanol and loss of acetone for Boc-NH-delta-Caa-beta-Caa-OCH(3) (18), whereas these are insignificant for its positional isomer Boc-NH-beta-Caa-delta-Caa-OCH(3) (13). The tetra- and hexapeptide positional isomers also show significant differences in MS(2) and MS(3) CID spectra. It is observed that 'b' ions are abundant when oxazolone structures are formed through five-membered cyclic transition state and cyclization process for larger 'b' ions led to its insignificant abundance. However, b(1)(+) ion is formed in case of delta,alpha-dipeptide that may have a six-membered substituted piperidone ion structure. Furthermore, ESI negative ion MS/MS has also been found to be useful for differentiating these isomeric peptide acids. Thus, the results of MS/MS of pairs of di-, tetra-, and hexapeptide positional isomers provide peptide sequencing information and distinguish the positional isomers. Copyright 2010 John Wiley & Sons, Ltd.

  5. Chemical analysis of radioactive mixed liquid wastes by Alpha/Gamma Spectrometry, ICP-OES and Arsenazo III

    Energy Technology Data Exchange (ETDEWEB)

    Ferreira, Eduardo G.A.; Ferreira, Rafael V.P.; Araujo, Leandro G.; Dellamano, Jose Claudio; Marumo, Julio T., E-mail: jtmarumo@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Taddei, Maria Helena Tirollo, E-mail: mhtaddei@cnen.gov.br [Comissao Nacional de Energia Nuclear (LAPOC/CNEN), Pocos de Caldas, MG (Brazil). Laboratorio de Pocos de Caldas

    2013-07-01

    Radioactive waste characterization is a very important step in radioactive waste management because it can influence subsequent stages, as waste conditioning, storage and disposal. This characterization must provide reliable information in order to satisfy some quality requirements based on chemical analysis of representative waste samples. This paper presents procedures adopted for characterization of thirteen different mixed liquid wastes stored at Waste Management Laboratory of Nuclear and Energy Research Institute, IPEN-CNEN/SP. The first action was the sampling of representative samples of each liquid storage package, followed by the alpha and gamma spectrometry, Arsenazo III and ICP-OES analysis. It was identified the radionuclides U, Pu, Cs and Am and others seven chemical elements. The results obtained will be used to perform the treatment of these wastes. (author)

  6. Determination of C and O and other elements by alpha-induced X-ray energy spectrometry

    International Nuclear Information System (INIS)

    Henningsen, W.P.; Schaetzler, H.P.; Kuehn, W.

    1978-01-01

    X-ray energy spectrometry combined with alpha-excitation by means of radionuclides, especially Po-210, has been found as a versatile tool for multielement analysis. Down to Z = 6 (carbon) qualitative and quantitative measurements have been carried out with energy resolution good enough to separate adjacent elements. Thereby errors and lowest detectable concentrations were in the region of one percent. By utilizing M- and L-X-radiation the set of detectable elements can be opened to high atomic numbers. As an example with special regard to environmental research cadmium in organic matrix was measured down to 100 ppm without any preconcentration. Much lower detection limits might be reached by appropriate measures. (orig.) [de

  7. Measurement of airborne concentrations of radon-220 daughter products by alpha-particle spectrometry

    International Nuclear Information System (INIS)

    Kerr, G.D.; Ryan, M.T.; Perdue, P.T.

    1978-01-01

    The decay of naturally occurring uranium-238 and thorium-232 produces radon-222 and radon-220 isotopes which can escape into the atmosphere. If these radon gases become concentrated in air, their daughter products may present an inhalation hazard to man. The airborne concentrations of radon-222 can usually be measured very accurately in the presence of normal airborne concentrations of radon-220 and its daughters. In contrast, the measurements of the airborne concentrations of radon-220 daughters are usually complicated by the presence of radon-222 and its daughters even at normally occurring airborne concentrations. The complications involved in these measurements can be overcome in most situations by using an alpha particle spectrometer to distinguish the activity of radon-222 daughters from that due to radon-220 daughters collected on a filter. A practical spectrometer for field measurements of alpha particle activity on a filter is discussed

  8. Alpha-ray spectrometry at high temperature by using a compound semiconductor detector.

    Science.gov (United States)

    Ha, Jang Ho; Kim, Han Soo

    2013-11-01

    The use of conventional radiation detectors in harsh environments is limited by radiation damage to detector materials and by temperature constraints. We fabricated a wide-band gap semiconductor radiation detector based on silicon carbide. All the detector components were considered for an application in a high temperature environment like a nuclear reactor core. The radiation response, especially to alpha particles, was measured using an (241)Am source at variable operating voltages at room temperature in the air. The temperature on detector was controlled from 30°C to 250°C. The alpha-particle spectra were measured at zero bias operation. Even though the detector is operated at high temperature, the energy resolution as a function of temperature is almost constant within 3.5% deviation. Copyright © 2013 Elsevier Ltd. All rights reserved.

  9. An experimental study of symmetric and asymmetric peak-fitting parameters for alpha-particle spectrometry

    International Nuclear Information System (INIS)

    Martin Sanchez, A.; Vera Tome, F.; Caceres Marzal, D.; Bland, C.J.

    1994-01-01

    A pulse-height spectrum of alpha-particle emissions at discrete energies can be fitted by the peak-shape functions generated by combining asymmetric truncated exponential functions with a symmetric Gaussian distribution. These functions have been applied successfully by several workers. A correlation was previously found between the variance of the symmetric Gaussian portion of the fitting function, and the parameter characterising the principal exponential tailing function. The results of a more detailed experimental study are reported, which involve varying the angle and the distance between the source and the detector. This analysis shows that the parameters of the symmetric and asymmetric parts of the fitted functions seem to depend on either the detector or the source. These parameters are influenced by the energy loss suffered by the alpha-particles as well as by the efficiency of charge collection in the solid-state detector. (orig.)

  10. Application of alpha spectrometry to the discovery of new elements by heavy-ion-beam bombardment

    International Nuclear Information System (INIS)

    Nitschke, J.M.

    1983-05-01

    Starting with polonium in 1898, α-spectrometry has played a decisive role in the discovery of new, heavy elements. For even-even nuclei, α-spectra have proved simple to interpret and exhibit systematic trends that allow extrapolation to unknown isotopes. The early discovery of the natural α-decay series led to the very powerful method of genetically linking the decay of new elements to the well-established α-emission of daughter and granddaughter nuclei. This technique has been used for all recent discoveries of new elements including Z = 109. Up to mendelevium (Z = 101), thin samples suitable for α-spectrometry were prepared by chemical methods. With the advent of heavy-ion accelerators new sample preparation methods emerged. These were based on the large momentum transfer associated with heavy-ion reactions, which produced energetic target recoils that, when ejected from the target, could be thermalized in He gas. Subsequent electrical deposition or a He-jet technique yielded samples that were not only thin enough for α-spectroscopy, but also for α- and #betta#-recoil experiments. Many variations of these methods have been developed and are discussed. For the synthesis of element 106 an aerosol-based recoil transport technique was devised. In the most recent experiments, α-spectrometry has been coupled with the magnetic analysis of the recoils. The time from production to analysis of an isotope has thereby been reduced to 10 - 6 s; while it was 10 - 1 to 10 0 s for He-jets and 10 1 to 10 3 s for rapid chemical separations. Experiments are now in progress to synthesize super heavy elements (SHE) and to analyze them with these latest techniques. Again, α-spectrometry will play a major role since the expected signature for the decay of a SHE is a sequence of α-decays followed by spontaneous fission

  11. Thorium: one of the analytical techniques in neutronic activation and alpha spectrometry of the CDTN (Brazilian Nuclear Technology Development Center) in the last three decades

    International Nuclear Information System (INIS)

    Menezes, M.A.B.C.; Sabino, C.V.S.

    1994-01-01

    For long years, the CDTN (Brazilian Nuclear Technology Development Center ) has applied several analytical techniques in the thorium determination. This work is about the evolution of the neutronic activation in the thorium 232 analysis from the 1960's to now. The importance of the analysis request and alpha spectrometry for the thorium 228 and thorium 232 determination is emphasized. (J.A.M.M.)

  12. Separation of Ra and Th from rock matrices for alpha-spectrometry

    International Nuclear Information System (INIS)

    Ditchburn, R.G.; Whitehead, N.E.

    1995-01-01

    Dating rocks using 226 Ra/ 230 Th isochrons demands radiochemical purification of radium and thorium. This paper presents an improved method. Rocks are solubilised by nitric/hydrofluoric digestion followed by dissolution of insoluble fluorides by boric/nitric acids, and Th is extracted by passing the 8M nitric solution through an anion column in nitrate form. The eluant contains Ra and Ba which are precipitated as sulphate and redissolved in alkaline EDTA. Complete separation of Ba and Ra from sulphate is on an AG 1 x 8 anion column in EDTA form, which was found better than the chloride form. The Ba+Ra is separated on an AG 50W x 8 cation column, and uses CDTA as an eluant for Ba. Careful pH control is essential. Ra elutes later with EDTA or 4M HCl and is precipitated with 125μg barium as sulphate to yield a source suitable for α-spectrometry, or further treated to electroplate the Ra. The yield tracers used are 228 Th and 224 Ra. Because the sample contains natural 224 Ra a correction must be applied, calculated from the amount of natural 232 Th in the Th spectrum. Th may be precipitated with 100 μg of ferric iron and gives a spectrometry-quality source, but further purification and electrodeposition was found to be preferable. Variations on the method for the case of analysis of calcium-rich fish otoliths are described. (author) 37 refs.; 3 figs

  13. A rapid method of extraction of uranium and thorium from granite for alpha spectrometry

    International Nuclear Information System (INIS)

    Gascoyne, M.; Larocque, J.P.A.

    1984-01-01

    The lithium metaborate fusion technique for analysis of rock samples has been adapted for the alpha spectrometric determination of uranium and thorium isotope abundances in granite. Powdered granite is spiked with a solution of a uranium-thorium isotope tracer, mixed with LiBO 2 in a 1: 3 ratio and fused at 950 o C in a graphite crucible. The mixture is poured into 1 M HNO 3 and stirred until dissolved. Uranium and thorium are simultaneously extracted with 10% tributylphosphate(TBP) in amyl acetate using AI(NO 3 ) 3 as the salting agent, and then back-extracted into 1 M H 2 SO 4 . Uranium is separated from thorium using anion exchange resin and, after further purification, each is plated onto steel discs for alpha counting. Overall chemical yields are adequate at present (generally 20 to 60%). Preliminary tests show the TBP extraction step to be almost quantitative for both elements, in spite of the presence of silicon and high concentrations of aluminium. This procedure is much faster than the usual acid digestion technique, and uranium and thorium discs for counting can be prepared in approximately eight hours, starting from rock powder. (author)

  14. A rapid method of extraction of uranium and thorium from granite for alpha spectrometry

    International Nuclear Information System (INIS)

    Gascoyne, M.; Larocque, J.P.A.

    1984-01-01

    The lithium metaborate fusion technique for analysis of rock samples has been adapted for the alpha spectrometric determination of uranium and thorium isotope abundances in granite. Powdered granite is spiked with a solution of a uranium-thorium isotope tracer, mixed with LiBO 2 in a 1:3 ratio and fused at 950 0 C in a graphite crucible. The mixture is poured into 1 M HNO 3 and stirred until dissolved. Uranium and thorium are simultaneously extracted with 10% tributylphosphate (TBP) in amyl acetate using Al(NO 3 ) 3 as the salting agent, and then back-extracted into 1 M H 2 SO 4 . Uranium is separated from thorium using anion exchange resin and, after further purification, each is plated onto steel discs for alpha counting. Overall chemical yields are adequate at present (generally 20 to 60%). Preliminary tests show the TBP extraction step to be almost quantitative for both elements, in spite of the presence of silicon and high concentrations of aluminium. This procedure is much faster than the usual digestion technique, and uranium and thorium discs for counting can be prepared in approximately eight hours, starting from rock powder. (orig.)

  15. A rapid method of extraction of uranium and thorium from granite for alpha spectrometry

    Science.gov (United States)

    Gascoyne, M.; Larocque, J. P. A.

    1984-06-01

    The lithium metaborate fusion technique for analysis of rock samples has been adapted for the alpha spectrometric determination of uranium and thorium isotope abundances in granite. Powdered granite is spiked with a solution of a uranium-thorium isotope tracer, mixed with LiBO 2 in a 1:3 ratio and fused at 950°C in a graphite crucible. The mixture is poured into 1 M HNO 3 and stirred until dissolved. Uranium and thorium are simultaneously extracted with 10% tributylphosphate (TBP) in amyl acetate using Al(NO 3) 3 as the salting agent, and then back-extracted into 1 M H 2SO 4. Uranium is separated from thorium using anion exchange resin and, after further purification, each is plated onto steel discs for alpha counting. Overall chemical yields are adequate at present (generally 20 to 60%). Preliminary tests show the TBP extraction step to be almost quantitative for both elements, in spite of the presence of silicon and high concentrations of aluminium. This procedure is much faster than the usual acid digestion technique, and uranium and thorium discs for counting can be prepared in approximately eight hours, starting from rock powder.

  16. Contribution to the study of the geophysical behaviour of lead-210 by application of alpha spectrometry; Contribution a l'etude du comportement geophysique du plomb 210 par application de la spectrometrie alpha

    Energy Technology Data Exchange (ETDEWEB)

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

    1965-06-01

    A study of the changes in the lead-210 contents of rain-water and of water produced by melting polar ice has required the development of a method for dosing lead-210, an {alpha} emitter. This method is 40 times more sensitive than that which measures the lead-210 by bismuth-210, a ({beta} emitter. The first part of the report presents the study of a spectrometry using semiconductor detectors; a catalogue of a spectra shows the advantages of this method. In the second part will be found at first a new chemical separation method for polonium-210 and the results obtained with this method. The main results obtained on the geophysical behaviour of lead-210 are the following: - the monthly lead-210 and polonium-210 contents in rain water are approximately constant with time. - in the Gif-sur-Yvette region, the clean-up by 'dry fall-out' can attain 40 to 50 per cent of the total fall-out. - a study of Antarctic ice samples makes it possible to determine an annual accumulation rate equivalent to 13.8 cm of water and to show discrepancies in the periodic concentrations which correspond to the latest maxima of solar activity. - a balance is drawn up between the radon produced by the continents and the lead-210 fall-out. (author) [French] Une etude sur les variations de la teneur en plomb 210 des eaux de pluie et des eaux de fusion des glaces polaires a necessite la mise au point d'une methode de dosage du plomb 210 emetteur {alpha}. Cette methode permet d'obtenir une sensibilite quarante fois superieure a celle dosant le plomb 210 par le bismuth 210 emetteur {beta}. La premiere partie du travail presente l'etude de la spectrometrie {alpha} par detecteur a semiconducteurs, un catalogue de spectres {alpha} met en evidence les avantages de cette methode. Dans la deuxieme partie on trouvera en premier lieu une nouvelle methode chimique de separation du polonium 210 ainsi que les resultats obtenus grace a cette methode. Les principaux resultats sur le

  17. A rapid method for determination of the isotopic composition of uranium samples by alpha spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Martin Sanchez, A.; Tome, F.V.; Diaz Bejarano, J.; Jurado Vargas, M. (Dept. de Fisica, Univ. Extremadura, Badajoz (Spain))

    1992-03-01

    A simple method of analyzing alpha spectra from natural and enriched or depleted uranium samples is developed. The procedure is non-iterative, and takes into consideration low-energy tail and branching-ratio corrections to accurately calculate the area corresponding to each uranium isotope ({sup 234}U, {sup 235}U, {sup 236}U, {sup 238}U) in the spectrum, and then the isotopic composition of the sample. A BASIC computer program, called ENURA, has been developed to perform all the necessary calculations to give the results together with their uncertainties. Several samples were prepared with different uranium concentrations made from standard solutions with known compositions, and the method was checked against the experimental measurements from these samples. Other series of uranium spectra were theoretically constructed using a given line shape in order to cover the required range of enriched or depleted uranium. (orig.).

  18. A rapid method for determination of the isotopic composition of uranium samples by alpha spectrometry

    Science.gov (United States)

    Sánchez, A. Martín; Tomé, F. Vera; Bejarano, J. Díaz; Vargas, M. Jurado

    1992-03-01

    A simple method of analyzing alpha spectra from natural and enriched or depleted uranium samples is developed. The procedure is non-iterative, and takes into consideration low-energy tail and branching-ratio corrections to accurately calculate the area corresponding to each uranium isotope (234U, 235U, 236U, 238U) in the spectrum, and then the isotopic composition of the sample. A BASIC computer program, called ENURA, has been developed to perform all the necessary calculations to give the results together with their uncertainties. Several samples were prepared with different uranium concentrations made from standard solutions with known compositions, and the method was checked against the experimental measurements from these samples. Other series of uranium spectra were theoretically constructed using a given line shape in order to cover the required range of enriched or depleted uranium.

  19. Derivatives of 16alpha-hydroxy-dehydroepiandrosterone with an additional 7-oxo or 7-hydroxy substituent: synthesis and gas chromatography/mass spectrometry analysis.

    Science.gov (United States)

    Pouzar, Vladimír; Cerný, Ivan; Hill, Martin; Bicíková, Marie; Hampl, Richard

    2005-10-01

    Derivatives of 16alpha-hydroxy-dehydroepiandrosterone, which have an additional oxygen substituent at position 7 (oxo or hydroxy group), were synthesized. Firstly, 17,17-dimethoxyandrost-5-ene-3beta,16alpha-diyl diacetate was prepared and then oxidized with a complex of chromium(VI) oxide and 2,5-dimethylpyrazole to the respective 7-oxo derivative. This key intermediate was both deprotected or reduced by l-Selectride or sodium borohydride in the presence of cerium(III) chloride and then deprotected to give 7-oxo, 7alpha-hydroxy and 7beta-hydroxy derivatives of 16alpha-hydroxy-dehydroepiandrosterone. The target compounds were characterized by (1)H and (13)C NMR spectra and in the form of O-methyloxime-trimethylsilyl derivatives, by gas chromatography/mass spectrometry methods.

  20. Determination of Neptunium, Americium and Curium in Spent Nuclear Fuel Samples by Alpha Spectrometry Using 239Np and 243Am as a Spike and a Tracer

    International Nuclear Information System (INIS)

    Jeo, Kih-Soo; Song, Byung-Chul; Kim, Young-Bok; Han, Sun-Ho; Jeon, Young-Shin; Jung, Euo-Chang; Jee, Kwang-Yong

    2007-01-01

    Determination of actinide elements and fission products in spent nuclear fuels is of importance for a burnup determination and source term evaluation. Especially, the amounts of uranium and plutonium isotopes are used for the evaluation of a burnup credit in spent nuclear fuels. Additionally, other actinides such as Np, Am and Cm in spent nuclear fuel samples is also required for the purposes mentioned above. In this study, 237 Np, 241 Am and 244 Cm were determined by an alpha spectrometry for the source term data for high burnup spent nuclear fuels ranging from 37 to 62.9 GWD/MtU as a burnup. Generally, mass spectrometry has been known as the most powerful method for isotope determinations such as high concentrations of uranium and plutonium. However, in the case of minor actinides such as Np, Am and Cm, alpha spectrometry would be recommended instead. Determination of the transuranic elements in spent nuclear fuel samples is different from that for environmental samples because the amount of each nuclide in the spent fuel samples is higher and the relative ratios between each nuclide are also different from those for environmental samples. So, it is important to select an appropriate tracer and an optimum sample size depending on the nuclides and analytical method. In this study 237 Np was determined by an isotope dilution alpha(gamma) spectrometry using 239 Np as a spike, and 241 Am and curium isotopes were determined by alpha spectrometry using 243 Am as a tracer. The content of each nuclide was compared with that by the Origen-2 code

  1. Contribution to the study of the geophysical behaviour of lead-210 by application of alpha spectrometry

    International Nuclear Information System (INIS)

    Nezami, M.

    1965-06-01

    A study of the changes in the lead-210 contents of rain-water and of water produced by melting polar ice has required the development of a method for dosing lead-210, an α emitter. This method is 40 times more sensitive than that which measures the lead-210 by bismuth-210, a (β emitter. The first part of the report presents the study of a spectrometry using semiconductor detectors; a catalogue of a spectra shows the advantages of this method. In the second part will be found at first a new chemical separation method for polonium-210 and the results obtained with this method. The main results obtained on the geophysical behaviour of lead-210 are the following: - the monthly lead-210 and polonium-210 contents in rain water are approximately constant with time. - in the Gif-sur-Yvette region, the clean-up by 'dry fall-out' can attain 40 to 50 per cent of the total fall-out. - a study of Antarctic ice samples makes it possible to determine an annual accumulation rate equivalent to 13.8 cm of water and to show discrepancies in the periodic concentrations which correspond to the latest maxima of solar activity. - a balance is drawn up between the radon produced by the continents and the lead-210 fall-out. (author) [fr

  2. Standard test method for radiochemical determination of uranium isotopes in soil by alpha spectrometry

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2011-01-01

    1.1 This test method covers the determination of alpha-emitting uranium isotopes in soil. This test method describes one acceptable approach to the determination of uranium isotopes in soil. 1.2 The test method is designed to analyze 10 g of soil; however, the sample size may be varied to 50 g depending on the activity level. This test method may not be able to completely dissolve all forms of uranium in the soil matrix. Studies have indicated that the use of hydrofluoric acid to dissolve soil has resulted in lower values than results using total dissolution by fusion. 1.3 The lower limit of detection is dependent on count time, sample size, detector, background, and tracer yield. The chemical yield averaged 78 % in a single laboratory evaluation, and 66 % in an interlaboratory collaborative study. 1.4 The values stated in SI units are to be regarded as standard. The values given in parentheses are for information only. 1.5 This standard does not purport to address all of the safety concerns, if any, ass...

  3. Radionuclide content of simulated and fully radioactive SRLLL waste glasses: comparison of results from ICP-MS, gamma spectrometry and alpha spectrometry

    International Nuclear Information System (INIS)

    Wolf, S.F.; Bates, J.K.

    1995-01-01

    We have measured the transuranic content of two transuranic=doped, simulated waste glasses, using inductively coupled plasma-mass spectrometry (ICP-MS), γ-spectrometry, and α-spectrometry. Average concentrations measured by each technique were within ± 10% of the as-doped concentrations. We also report the transuranic content of three fully radioactive SRL waste glasses that were determined using γ- and α-spectrometry measurements to deconvolute isobaric interferences present in the ICP-MS analyses

  4. Application of the alpha spectrometry for the study of core sediment extracted in the San Marcos dam in Chihuahua

    International Nuclear Information System (INIS)

    Mendez G, C.; Renteria V, M.; Montero C, M. E.; Garcia T, R.

    2012-01-01

    The determination of the specific activities of 210 Po and isotopic uranium by alpha spectrometry was performed in a sediment core from San Marcos Dam. The objective of this work was to analyze the vertical distribution of isotopic uranium and 210 Po and the behavior of these radionuclides along sediment core collected from the San Marcos Dam. Sample was divided into 11 sections, in which 210 Po and isotopic uranium were determined using liquid-liquid extraction with tributyl phosphate. Furthermore, it was made a comparison between the tributyl phosphate technique and the technique of extraction chromatography using UTEVA resins for uranium. The results of specific activities for 210 Po show a trend to decrease along the core, whereas the uranium isotopic does not show a pointed trend. The results of isotopic ratios between the 234 U and 238 U show that they are close to secular equilibrium in each of the core sections. The comparison between the two uranium extraction techniques indicates that the chemical yield is better using the UTEVA technique than tributyl phosphate extraction. (Author)

  5. Application of the alpha spectrometry for the study of core sediment extracted in the San Marcos dam in Chihuahua

    Energy Technology Data Exchange (ETDEWEB)

    Mendez G, C.; Renteria V, M.; Montero C, M. E. [Centro de Investigacion en Materiales Avanzados, S. C., Miguel de Cervantes No. 120, Complejo Industrial Chihuahua, 31109 Chihuahua (Mexico); Garcia T, R., E-mail: elena.montero@cimav.edu.mx [Universidad de Sevilla, Escuela Tecnica Superior de Arquitectura, Grupo de Fisica Nuclear Aplicada, Av. Reina Mercedes s/n, 41012 Sevilla (Spain)

    2012-06-15

    The determination of the specific activities of {sup 210}Po and isotopic uranium by alpha spectrometry was performed in a sediment core from San Marcos Dam. The objective of this work was to analyze the vertical distribution of isotopic uranium and {sup 210}Po and the behavior of these radionuclides along sediment core collected from the San Marcos Dam. Sample was divided into 11 sections, in which {sup 210}Po and isotopic uranium were determined using liquid-liquid extraction with tributyl phosphate. Furthermore, it was made a comparison between the tributyl phosphate technique and the technique of extraction chromatography using UTEVA resins for uranium. The results of specific activities for {sup 210}Po show a trend to decrease along the core, whereas the uranium isotopic does not show a pointed trend. The results of isotopic ratios between the {sup 234}U and {sup 238}U show that they are close to secular equilibrium in each of the core sections. The comparison between the two uranium extraction techniques indicates that the chemical yield is better using the UTEVA technique than tributyl phosphate extraction. (Author)

  6. Measurement of short-lived radon progenies by simultaneous alpha gamma-spectrometry at the German radon reference chamber

    CERN Document Server

    Paul, A; Honig, A; Sulima, T; Buchholz, A; Keyser, U

    1999-01-01

    In the German radon reference chamber, the short-lived radon progenies are separated by a sample tube according to the attached or unattached fraction, while their activity concentration is afterwards measured by simultaneous alpha- and gamma-spectrometry. The results are expressed by the equilibrium factor F and the unattached fraction f sub p (International Commission on Radiological Protection, ICRP Publication 50, Ann. ICRP 17 (1987) 1). Both F and f sub p , can be therefore studied with respect to the full set of environmental parameters, e.g. temperature, humidity, air pressure and aerosol concentration (Honig et al., Nucl. Instr. and Meth. A 416 (1998) 525). Up to now, well-defined and stable equilibrium factors in the interval from 0.1 to 1.0 have been established. In correlation with this, the unattached fraction can be varied from 0.01 to 0.9. The sample and measuring technique for the short-lived radon progenies described in this work is the basis for fundamental studies with regard to the equilibr...

  7. Alpha spectrometry Analysis of radioisotopes of thorium and uranium in the soil (IAEA soil reference ground 375 and the natural region of Utique (Bizerte))

    International Nuclear Information System (INIS)

    Mejri, Mouna

    2008-01-01

    Since the formation of the terrestrial crust, the primordial radionuclides are present in the minerals. The main are the radioactive elemnts of the Uranium 238, of Uranium 235, of the Thorium 232 chains, Potassium 40 and the Ribidium 87. In this survey, we will present the methodology of analysis of the natural radioisotopes of uranium ( 238 U, 235 U and 234 U) and those of the thorium ( 232 Th, 230 Th and 228 Th) presents to the state of tracers in the natural soils. The method of measurement used is the alpha spectrometry. This technique is very important in the radiometric analysis, especially for the pure alpha emitters or for the low levels of radioactivity analysis. The results if analysis of the Thorium are compared to those gotten by the ICP - AES ( t he Atomic Emission Spectrometry Coupled to an inductive Plasma ) . (Author)

  8. Estimation of ultra trace plutonium isotopy ({approx_equal}10{sup -9} G) by alpha spectrometry; Estimation de l'isotopie du plutonium par spectrometrie alpha, a partir d'ultra traces ({approx_equal}10{sup -9} G) contenues dans les echantillons

    Energy Technology Data Exchange (ETDEWEB)

    Curnier, J.P.; Andrieu, G. [Cogema, 30 - Marcoule (France)

    1997-07-01

    Alpha emission spectrometry has been used to determine the activity or mass ratio between the plutonium isotopes 239 and 240 with a sensitivity of about 10%. It is nevertheless necessary to have an energy resolution of about 10 keV and an electrolytic plutonium deposit on a stainless steel sheet of about 10{sup -8} g (or 1 Bq)

  9. Quantitative Measurement of Intact Alpha-Synuclein Proteoforms from Post-Mortem Control and Parkinson's Disease Brain Tissue by Intact Protein Mass Spectrometry

    Science.gov (United States)

    Kellie, John F.; Higgs, Richard E.; Ryder, John W.; Major, Anthony; Beach, Thomas G.; Adler, Charles H.; Merchant, Kalpana; Knierman, Michael D.

    2014-07-01

    A robust top down proteomics method is presented for profiling alpha-synuclein species from autopsied human frontal cortex brain tissue from Parkinson's cases and controls. The method was used to test the hypothesis that pathology associated brain tissue will have a different profile of post-translationally modified alpha-synuclein than the control samples. Validation of the sample processing steps, mass spectrometry based measurements, and data processing steps were performed. The intact protein quantitation method features extraction and integration of m/z data from each charge state of a detected alpha-synuclein species and fitting of the data to a simple linear model which accounts for concentration and charge state variability. The quantitation method was validated with serial dilutions of intact protein standards. Using the method on the human brain samples, several previously unreported modifications in alpha-synuclein were identified. Low levels of phosphorylated alpha synuclein were detected in brain tissue fractions enriched for Lewy body pathology and were marginally significant between PD cases and controls (p = 0.03).

  10. Determination of radium isotopes in environmental samples by gamma spectrometry, liquid scintillation counting and alpha spectrometry: a review of analytical methodology

    International Nuclear Information System (INIS)

    Jia, Guogang; Jia, Jing

    2012-01-01

    Radium (Ra) isotopes are important from the viewpoints of radiation protection and environmental protection. Their high toxicity has stimulated the continuing interest in methodology research for determination of Ra isotopes in various media. In this paper, the three most routinely used analytical techniques for Ra isotope determination in biological and environmental samples, i.e. low-background γ-spectrometry, liquid scintillation counting and α-spectrometry, were reviewed, with emphasis on new methodological developments in sample preparation, preconcentration, separation, purification, source preparation and measurement techniques. The accuracy, selectivity, traceability, applicability and minimum detectable activity (MDA) of the three techniques were discussed. It was concluded that the MDA (0.1 mBq L −1 ) of the α-spectrometry technique coupled with chemical separation is about two orders of magnitude lower than that of low-background HPGe γ-spectrometry and LSC techniques. Therefore, when maximum sensitivity is required, the α-spectrometry technique remains the first choice. - Highlights: ► A review is made for determination of Ra isotopes in environmental samples. ► Gamma spectrometry, LSC and a-spectrometry are the main concerned radiometric approach. ► Sample preparation, preconcentration, separation and source preparation are discussed. ► The methods can analyse air, water, seawater, soil, sediment and foodstuffs samples. ► Some new data obtained recently from our laboratory for Ra method study are included.

  11. Determination of 222Rn in fresh water: development of a robust method of analysis by alpha/beta separation liquid scintillation spectrometry.

    Science.gov (United States)

    Pates, Jacqueline M; Mullinger, Neil J

    2007-01-01

    Liquid scintillation spectrometry is used widely for determining (222)Rn in natural waters; however, the benefits of alpha/beta separation have not been fully explored. The extractants toluene and Ultima Gold F were compared, and both performed well for a range of extreme waters. A robust method for calibrating extraction and counting efficiencies has been developed. Detection limits are 20 mBql(-1) (toluene) and 16 mBql(-1) (UGF) for a 60 min count and 600-ml sample, halving the required sample volume.

  12. Comparison of the analytical methods used to determine natural and artificial radionuclides from environmental samples by gamma, alpha and beta spectrometry

    DEFF Research Database (Denmark)

    Pöllänen, Roy; Virtanen, Sinikka; Kämäräinen, Meerit

    In CAMNAR, an extensive interlaboratory exercise on the analytical methods used to determine several radionuclides present in the environmental samples was organized. Activity concentration of different natural radionuclides, such as Rn-222, Pb-210, Po-210, K-40, Ra-226, Ra-228 and isotopes of ur...... Nordic and European countries participated in the intercomparison. Extraordinary variation between the results reported by different laboratories were revealed for some radionuclides indicating the need of future intercomparisons especially in the case of natural water samples.......In CAMNAR, an extensive interlaboratory exercise on the analytical methods used to determine several radionuclides present in the environmental samples was organized. Activity concentration of different natural radionuclides, such as Rn-222, Pb-210, Po-210, K-40, Ra-226, Ra-228 and isotopes...... of uranium, in addition to artificial Cs-137 and Am-241 were analysed from lake sediment samples and drinking water. The measurement techniques were gamma-ray spectrometry, alpha spectrometry, liquid scintillation counting and inductively coupled plasma mass spectrometry. Twenty six laboratories from nine...

  13. Application of MALDI-TOF mass spectrometry for study on fibrillar and oligomeric aggregates of alpha-synuclein

    NARCIS (Netherlands)

    Severinovskaya, O. V.; Kovalska, V B; Losytskyy, M Yu; Cherepanov, V. V.; Subramaniam, V.; Yarmoluk, S M

    2014-01-01

    Aim. To study the α-synuclein (ASN) aggregates of different structural origin, namely amyloid fibrils and spherical oligomers, in comparison with a native protein. Methods. MALDI TOF mass spectrometry and atomic force microscopy (AFM). Results. The mass spectra of native and fibrillar ASN have

  14. Implantation of alpha spectrometry methodology for the determination of U and Th isotopes in igneous rocks: application to the study of radioactive desequilibrium in the Trindade Island, Brazil

    International Nuclear Information System (INIS)

    Santos, Rosana Nunes dos

    2001-01-01

    This work describes the implementation of experimental procedures for alpha spectrometry measurement of 238 U, 234 U and 230 Th activities in silicates. The best experimental conditions were defined using 233 U, 232 U and 229 Th radioactive tracers and simulating the usual conditions found in processing silicates. The chemical procedures consists of the following steps: radioactive tracer addition and sample dissolution by acid digestion, U and Th pre-concentration by co-precipitation, element separation and purification by ion exchange chromatography and electrodeposition in inox steel disks. In order to evaluate its effectiveness, the procedure was applied to the Brazilian geological standards BB-1 (basalt) and GB-1 (granite). The obtained chemical yields for uranium and thorium are of about 60% and 70%, respectively, for both matrices. The described methodology furnishes activity measurements with less than 4% relative precision and accuracies of about 1%, that are essential for petrogenetic applications. The 238 U and 232 Th series disequilibrium conditions were investigated by alpha spectrometry, together with neutron activation analysis and natural gamma-ray spectrometry. 234 U/ 238 U, 238 U/ 232 Th and 230 Th/ 232 Th activity ratios and the 234 Th, 214 Pb, 214 Bi, 235 U, 228 Ac, 212 Pb, 212 Bi and 208 Tl specific activities were obtained. These results were interpreted with the help of additional constraints given by the larger and smaller elements concentrations, measured by X-ray fluorescence. The 232 Th series is in secular radioactive equilibrium in all analysed samples. In the case of the 238 U series, the equilibrium condition was verified, as expected, in the oldest rocks from the Trindade Island (Trindade Complex and Desejado Sequence). On the other hand, the results show that, in the samples from the last three volcanic episodes in the island (Morro Vermelho Formation, Valado Formation and Vulcao do Paredao), the 230 Th and 238 U are not in

  15. Localization of an O-glycosylated site in the recombinant barley alpha-amylase 1 produced in yeast and correction of the amino acid sequence using matrix-assisted laser desorption/ionization mass spectrometry of peptide mixtures

    DEFF Research Database (Denmark)

    Andersen, Jens S.; Søgaard, M; Svensson, B

    1994-01-01

    Matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) of peptide mixtures was used to characterize recombinant barley alpha-amylase 1, produced in yeast. Three peptide mixtures were generated by cleavage with CNBr, digestion with endoproteinase Lys-C and Asp-N, respectively...

  16. Characterization of the occupational exposure and air transported particles using the techniques of PIXE 252Cf PMDS and alpha spectrometry

    International Nuclear Information System (INIS)

    Carneiro, Luana Gomes

    2008-01-01

    The risk for human health due to exposure to aerosols depends on the intake pattern, the mass concentration and the speciation of the elements present in airborne particles. In this work PDMS (Plasma Desorption Mass Spectrometry) was used as complementary technique to the PIXE (Particle Induced X ray Emission) technique to characterize aerosols samples collected in the environment. The PIXE technique allows the identification of the elements present in the sample and to determine their mass concentrations. The mass spectrometry (PDMS) was used to identify the speciation of these elements present in the samples. The aerosol samples were collected using a six stage cascade impactor in three sites. The Mass Median Aerodynamic Diameter (MMAD) measured indicated that the airborne particulate were in the fine fraction of the aerosols. The theoretical uranium concentration in urine samples using ICRP lung model parameters suggest that the elemental mass concentration in respirable fraction of aerosol and the chemical speciation are important factors to determine the uranium concentration in urine and that the determination of specific solubility parameters for each compound is the most important factor to calculate the uranium concentration in urine. PIXE allows to identify and quantify the elements heavier than Na (Z=11) while PDMS allows to identify the organic and inorganic compounds present in the samples. As these techniques are used as complementary techniques they provide important information about the aerosols characterization. (author)

  17. AN EXPERIMENTAL INVESTIGATION OF THE 236U DETECTION LIMIT IN THE SURFACE AIR USING RADIOCHEMICAL SEPARATION AND ALPHA-SPECTROMETRY

    Directory of Open Access Journals (Sweden)

    A. D. Gedeonov

    2011-01-01

    Full Text Available Due to nuclear weapon testing, nuclear reactor accidents, uranium mining and nuclear fuel reprocessing, additional uranium has been introduced into the environment. 236U isotope is produced from 235U by capture of a thermal neutron and it can be used as an indicator for artificial uranium in the environment. In this paper the sensitive method for236U determination in the surface air is described. This method includes a total dissolution of the air dust in a mixture of mineral acids, uranium concentration and purification by anion-exchange chromatography. Long time measurements of the separated uranium fraction are made with the use of alpha-spectrometer based on PIPS-detector. The lower limit of detection for 236U in the surface air is determined as 5 • 10-9 Bq/m3 (2 ng/m3.

  18. Analysis of plutonium isotope ratios including238Pu/239Pu in individual U-Pu mixed oxide particles by means of a combination of alpha spectrometry and ICP-MS.

    Science.gov (United States)

    Esaka, Fumitaka; Yasuda, Kenichiro; Suzuki, Daisuke; Miyamoto, Yutaka; Magara, Masaaki

    2017-04-01

    Isotope ratio analysis of individual uranium-plutonium (U-Pu) mixed oxide particles contained within environmental samples taken from nuclear facilities is proving to be increasingly important in the field of nuclear safeguards. However, isobaric interferences, such as 238 U with 238 Pu and 241 Am with 241 Pu, make it difficult to determine plutonium isotope ratios in mass spectrometric measurements. In the present study, the isotope ratios of 238 Pu/ 239 Pu, 240 Pu/ 239 Pu, 241 Pu/ 239 Pu, and 242 Pu/ 239 Pu were measured for individual Pu and U-Pu mixed oxide particles by a combination of alpha spectrometry and inductively coupled plasma mass spectrometry (ICP-MS). As a consequence, we were able to determine the 240 Pu/ 239 Pu, 241 Pu/ 239 Pu, and 242 Pu/ 239 Pu isotope ratios with ICP-MS after particle dissolution and chemical separation of plutonium with UTEVA resins. Furthermore, 238 Pu/ 239 Pu isotope ratios were able to be calculated by using both the 238 Pu/( 239 Pu+ 240 Pu) activity ratios that had been measured through alpha spectrometry and the 240 Pu/ 239 Pu isotope ratios determined through ICP-MS. Therefore, the combined use of alpha spectrometry and ICP-MS is useful in determining plutonium isotope ratios, including 238 Pu/ 239 Pu, in individual U-Pu mixed oxide particles. Copyright © 2016 Elsevier B.V. All rights reserved.

  19. Simultaneous determinations of uranium, thorium, and plutonium in soft tissues by solvent extraction and alpha-spectrometry

    International Nuclear Information System (INIS)

    Singh, N.P.; Zimmerman, C.J.; Lewis, L.L.; Wrenn, M.E.

    1984-01-01

    A radiochemical procedure for the simultaneous determination of uranium, thorium, and plutonium, in soft tissues has been developed. The weighed amounts of tissues, spiked with 232 U, 242 Pu, and 229 th tracers, are wet ashed. Uranium, thorium, and plutonium are coprecipitated with iron as hydroxides, dissolved in concentrated HCl and the acidity adjusted to 10 M. Uranium and plutonium are extracted into 20% TLA solution in xylene, leaving thorium in the aqueous phase. Plutonium is back-extracted by reducing to the trivalent state with 0.05 M NH 4 I solution in 8 M HCl, and uranium is back-extracted with 0.1 M HCl. Thorium is extracted into 20% TLA solution from 4 M HNO 3 and back-extracted with 10 M HCl. Uranium, thorium and plutonium are electrodeposited separately onto platinum discs and counted alpha-spectrometrically using surface barrier silicon diodes and a multichannel analyzer. The method was developed using bovine liver and applied to dog and human tissues. The mean radiochemical recoveries of these actinides in different organs were better than 70%. 6 references, 2 tables

  20. The Use of Isotope Dilution Alpha Spectrometry and Liquid Scintillation Counting to Determine Radionuclides in Environmental Samples (abstract)

    Science.gov (United States)

    Bylyku, Elida

    2009-04-01

    In Albania in recent years it has been of increasing interest to determine various pollutants in the environment and their possible effects on human health. The radiochemical procedure used to identify Pu, Am, U, Th, and Sr radioisotopes in soil, sediment, water, coal, and milk samples is described. The analysis is carried out in the presence of respective tracer solutions and combines the procedure for Pu analysis based on anion exchange, the selective method for Sr isolation based on extraction chromatography using Sr-Spec resin, and the application of the TRU-Spec column for separation of Am fraction. An acid digestion method has been applied for the decomposition of samples. The radiochemical procedure involves the separation of Pu from Th, Am, and Sr by anion exchange, followed by the preconcentration of Am and Sr by coprecipitation with calcium oxalate. Am is separated from Sr by extraction chromatography. Uranium is separated from the bulk elements by liquid-liquid extraction using UTEVA® resin. Thin sources for alpha spectrometric measurements are prepared by microprecipitation with NdF3. Two International Atomic Energy Agency reference materials were analyzed in parallel with the samples.

  1. Development of a methodology for the detection of Ra226 in large volumes of water by gamma spectrometry; modification and validation of the method for detection and quantification of Ra226 in small volumes of water by alpha spectrometry, used by the Centro de Investigacion en Ciencias Atomicas, Nucleares y Moleculares (CICANUM, UCR)

    International Nuclear Information System (INIS)

    Molina Porras, Arnold

    2011-01-01

    The test method has been validated for quantifying the specific activity of Ra 226 in water alpha spectrometry. The CICANUM has used this method as part of the proposed harmonization of methods ARCAL (IAEA). The method is based on a first separation and preconcentration of Ra 226 by coprecipitation and subsequent MnO 2 micro precipitation as Ba (Ra) SO 4 . Samples were prepared and then was performed the counting by alpha spectrometry. A methodology of radio sampling for large volumes of water was tested in parallel, using acrylic fibers impregnated with manganese oxide (IV) to determine the amount of Ra 226 present by gamma spectrometry. Small-scale tests, have determined that the best way to prepare the fiber is the reference method found in the literature and using the oven at 60 degrees Celsius. (author) [es

  2. Magnetic immunoassay coupled with inductively coupled plasma mass spectrometry for simultaneous quantification of alpha-fetoprotein and carcinoembryonic antigen in human serum

    Science.gov (United States)

    Zhang, Xing; Chen, Beibei; He, Man; Zhang, Yiwen; Xiao, Guangyang; Hu, Bin

    2015-04-01

    The absolute quantification of glycoproteins in complex biological samples is a challenge and of great significance. Herein, 4-mercaptophenylboronic acid functionalized magnetic beads were prepared to selectively capture glycoproteins, while antibody conjugated gold and silver nanoparticles were synthesized as element tags to label two different glycoproteins. Based on that, a new approach of magnetic immunoassay-inductively coupled plasma mass spectrometry (ICP-MS) was established for simultaneous quantitative analysis of glycoproteins. Taking biomarkers of alpha-fetoprotein (AFP) and carcinoembryonic antigen (CEA) as two model glycoproteins, experimental parameters involved in the immunoassay procedure were carefully optimized and analytical performance of the proposed method was evaluated. The limits of detection (LODs) for AFP and CEA were 0.086 μg L- 1 and 0.054 μg L- 1 with the relative standard deviations (RSDs, n = 7, c = 5 μg L- 1) of 6.5% and 6.2% for AFP and CEA, respectively. Linear range for both AFP and CEA was 0.2-50 μg L- 1. To validate the applicability of the proposed method, human serum samples were analyzed, and the obtained results were in good agreement with that obtained by the clinical chemiluminescence immunoassay. The developed method exhibited good selectivity and sensitivity for the simultaneous determination of AFP and CEA, and extended the applicability of metal nanoparticle tags based on ICP-MS methodology in multiple glycoprotein quantifications.

  3. In Situ Peroxidase Labeling and Mass-Spectrometry Connects Alpha-Synuclein Directly to Endocytic Trafficking and mRNA Metabolism in Neurons.

    Science.gov (United States)

    Chung, Chee Yeun; Khurana, Vikram; Yi, Song; Sahni, Nidhi; Loh, Ken H; Auluck, Pavan K; Baru, Valeriya; Udeshi, Namrata D; Freyzon, Yelena; Carr, Steven A; Hill, David E; Vidal, Marc; Ting, Alice Y; Lindquist, Susan

    2017-02-22

    Synucleinopathies, including Parkinson's disease (PD), are associated with the misfolding and mistrafficking of alpha-synuclein (α-syn). Here, using an ascorbate peroxidase (APEX)-based labeling method combined with mass spectrometry, we defined a network of proteins in the immediate vicinity of α-syn in living neurons to shed light on α-syn function. This approach identified 225 proteins, including synaptic proteins, proteins involved in endocytic vesicle trafficking, the retromer complex, phosphatases and mRNA binding proteins. Many were in complexes with α-syn, and some were encoded by genes known to be risk factors for PD and other neurodegenerative diseases. Endocytic trafficking and mRNA translation proteins within this spatial α-syn map overlapped with genetic modifiers of α-syn toxicity, developed in an accompanying study (Khurana et al., this issue of Cell Systems). Our data suggest that perturbation of these particular pathways is directly related to the spatial localization of α-syn within the cell. These approaches provide new avenues to systematically examine protein function and pathology in living cells. Copyright © 2017 Elsevier Inc. All rights reserved.

  4. Gas chromatography-mass spectrometry microanalysis of alpha- and gamma-tocopherol in plasma and whole blood.

    Science.gov (United States)

    Zerbinati, C; Galli, F; Regolanti, R; Poli, G; Iuliano, L

    2015-06-15

    Assessing vitamin E status in humans is critical for nutritional evaluation and verification of clinical and biological compliance of supplemented subjects. An accurate analytical method for measuring the two main vitamin E isoforms, i.e. α- and γ-tocopherol (α- and γ-TOH) in small volumes of plasma can facilitate the application of this analysis to clinical trials and in situations where a limited amount of sample is available. We have developed a micro method, which uses only 5 μL plasma, based on isotope dilution, trimethylsilation and GC-MS. The method was validated according to the guidelines of the International Conference on Harmonization of analytical procedures. The method was also applied to 5 μL of whole blood for the potential use in conditions were the availability of specimens is limited. Accurate quantitation of α-TOH and γ-TOH was achieved at levels ≥ 0.417 μM and ≥ 0.007 μM, respectively. Within-day coefficient of variation was 1.31% and 4.70% for α-TOH and γ-TOH, respectively. Between-day coefficient of variation was 1.32% and 2.88% for α-TOH and γ-TOH, respectively. Recovery, assessed at three concentration levels, ranged 98-103% and 100-102% for α-TOH and γ-TOH, respectively. The method allowed the detection of α-TOH and γ-TOH in 5 μL whole blood and in membranes of red blood cells washed from 5 μL of blood as well. The analytical performance was assessed in plasma from a cohort of Italian healthy subjects (n = 205). The mean plasma concentrations were 28.01 ± 6.31 and 0.68 ± 0.48 μM (mean ± SD) for α-TOH and γ-TOH, respectively. Alpha-TOH correlated with total cholesterol (r = 0.617, p < 0.0001) and triglycerides (r = 0.420, p < 0.0001) while γ-TOH correlated modestly with total cholesterol (r = 0.213, p < 0.0001) but not with triglycerides. γ-TOH, but not α-TOH, was significantly lower in smokers than in non-smokers (0.72 ± 0.50 vs. 0.56 ± 0.37, μM, mean ± SD, p = 0.017). Given the high sensitivity, the

  5. Magnetic immunoassay coupled with inductively coupled plasma mass spectrometry for simultaneous quantification of alpha-fetoprotein and carcinoembryonic antigen in human serum

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Xing; Chen, Beibei; He, Man; Zhang, Yiwen; Xiao, Guangyang; Hu, Bin, E-mail: binhu@whu.edu.cn

    2015-04-01

    The absolute quantification of glycoproteins in complex biological samples is a challenge and of great significance. Herein, 4-mercaptophenylboronic acid functionalized magnetic beads were prepared to selectively capture glycoproteins, while antibody conjugated gold and silver nanoparticles were synthesized as element tags to label two different glycoproteins. Based on that, a new approach of magnetic immunoassay-inductively coupled plasma mass spectrometry (ICP-MS) was established for simultaneous quantitative analysis of glycoproteins. Taking biomarkers of alpha-fetoprotein (AFP) and carcinoembryonic antigen (CEA) as two model glycoproteins, experimental parameters involved in the immunoassay procedure were carefully optimized and analytical performance of the proposed method was evaluated. The limits of detection (LODs) for AFP and CEA were 0.086 μg L{sup −1} and 0.054 μg L{sup −1} with the relative standard deviations (RSDs, n = 7, c = 5 μg L{sup −1}) of 6.5% and 6.2% for AFP and CEA, respectively. Linear range for both AFP and CEA was 0.2–50 μg L{sup −1}. To validate the applicability of the proposed method, human serum samples were analyzed, and the obtained results were in good agreement with that obtained by the clinical chemiluminescence immunoassay. The developed method exhibited good selectivity and sensitivity for the simultaneous determination of AFP and CEA, and extended the applicability of metal nanoparticle tags based on ICP-MS methodology in multiple glycoprotein quantifications. - Highlights: • 4-Mercaptophenylboronic acid functionalized magnetic beads were prepared and characterized. • ICP-MS based magnetic immunoassay approach was developed for quantification of glycoproteins. • AFP and CEA were quantified simultaneously with Au and Ag NPs as element tags. • The developed method exhibited good selectivity and sensitivity for target glycoproteins.

  6. Description of analytical method and clinical utility of measuring serum 7-alpha-hydroxy-4-cholesten-3-one (7aC4) by mass spectrometry.

    Science.gov (United States)

    Donato, Leslie J; Lueke, Alan; Kenyon, Stacy M; Meeusen, Jeffrey W; Camilleri, Michael

    2018-02-01

    Imbalance of bile acids (BA) homeostasis in the gastrointestinal tract can lead to chronic diarrhea or constipation when BA in the colon are in excess or low, respectively. Since both disturbances of bowel function can result from other etiologies, identifying BA imbalance is important to tailor treatment strategies. Serum concentrations of 7-alpha-hydroxy-4-cholesten-3-one (7aC4), a precursor in bile acid synthesis, reflect BA homeostasis. Here we describe a method to accurately measure serum 7aC4 and evaluate the clinical utility in patients with diarrhea or constipation phenotypes. Serum 7aC4 is measured after acetonitrile protein precipitation using C18 liquid chromatography, tandem mass spectrometry, and deuterium-labeled 7aC4 internal standard. Assay performance including linearity, precision, and accuracy was assessed using waste serum samples. The reference interval was established in healthy individuals without BA-altering conditions or medications. Clinical performance was assessed in patients with irritable bowel syndrome. The method precisely and accurately measured 7aC4 in human serum from 1.4-338ng/mL with no ion suppression or interference from related 7-keto-cholesterol. Central 95th percentile reference interval was 2.5-63.2ng/mL. Lower serum 7aC4 was found in patients with constipation with sensitivity/specificity of 79%/55% compared to healthy controls. Higher 7aC4 was found in patients with bile acid diarrhea (BAD) compared to those without BAD with sensitivity/specificity of 82%/53%. We have developed a sensitive and precise assay for measuring the concentration of 7aC4 in serum. The assay can be used to screen for diarrhea caused by bile acid malabsorption. Copyright © 2017 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.

  7. A sequential method for the determination of 210Pb, 226Ra, and uranium and thorium radioisotopes by LSC and alpha-spectrometry.

    Science.gov (United States)

    Lozano, J C; Tomé, F Vera; Rodríguez, P Blanco; Prieto, C

    2010-01-01

    A procedure for the determination of (210)Pb, and alpha-emitting radioisotopes of uranium, thorium, and radium from the same aliquot of a sample has been proposed. The key step consisted in the recovery of Pb(II) and Ra by precipitation of insoluble Pb(NO(3))(2), the uranium and thorium radioisotopes remaining in solution. Afterwards, the fractions were handled by specific, well consolidated procedures. Lead-210 was determined by the LSC technique while the uranium, thorium, and radium radioisotopes were measured with silicon alpha-spectrometers. The procedure was applied to a reference sample and several environmental samples obtaining satisfactory results. Copyright 2009 Elsevier Ltd. All rights reserved.

  8. Direct determination of the estrogenic compounds 8-prenylnaringenin, zearalenone, alpha- and beta-zearalenol in beer by liquid chromatography-mass spectrometry.

    Science.gov (United States)

    Maragou, Niki C; Rosenberg, Erwin; Thomaidis, Nikolaos S; Koupparis, Michael A

    2008-08-15

    A novel LC-ESI-MS method for the simultaneous determination of four of the most significant estrogenic compounds naturally occurring in beer, 8-prenylnaringenin (8-PN), zearalenone (ZON), alpha-zearalenol (alpha-ZOL) and beta-zearalenol (beta-ZOL) which requires minimal sample preparation was developed using a chemometric approach. Experimental design was applied to assess the effects of the LC-ESI-MS parameters (mobile phase flow rate, drying gas flow, nebuliser pressure and capillary potential) on the obtained signal and to optimize the values in order to provide maximum sensitivity and detectability. The proposed method is simple, consisting only of degassing the beer and diluting with water (1:1, v/v) before injection. Comparison between the two internal standards used, zearalanone (ZAN) and 4,2'-dihydroxychalcone (4,2'-DHC), showed that ZAN performs better as internal standard not only for the mycotoxins but for 8-PN as well, giving lower % RSDs. Under inter-day conditions mean recoveries were 107% for ZON, 87.8% for alpha-ZOL, 72.8% for beta-ZOL, and 77.5% for 8-PN. The corresponding % RSDs ranged between 5.0 and 8.0. The method limits of detection were 1.3, 1.4, 1.0 and 0.8 ng mL(-1) for ZON, alpha-ZOL, beta-ZOL and 8-PN, respectively. The method was applied to 15 beer samples obtained from local supermarkets and the concentration of the phytoestrogen 8-PN in beer ranged between <0.8 and 38.6 ng mL(-1), while neither ZON nor its metabolites, alpha-ZOL and beta-ZOL, were detected.

  9. Boron concentration measurements by alpha spectrometry and quantitative neutron autoradiography in cells and tissues treated with different boronated formulations and administration protocols.

    Science.gov (United States)

    Bortolussi, Silva; Ciani, Laura; Postuma, Ian; Protti, Nicoletta; Luca Reversi; Bruschi, Piero; Ferrari, Cinzia; Cansolino, Laura; Panza, Luigi; Ristori, Sandra; Altieri, Saverio

    2014-06-01

    The possibility to measure boron concentration with high precision in tissues that will be irradiated represents a fundamental step for a safe and effective BNCT treatment. In Pavia, two techniques have been used for this purpose, a quantitative method based on charged particles spectrometry and a boron biodistribution imaging based on neutron autoradiography. A quantitative method to determine boron concentration by neutron autoradiography has been recently set-up and calibrated for the measurement of biological samples, both solid and liquid, in the frame of the feasibility study of BNCT. This technique was calibrated and the obtained results were cross checked with those of α spectrometry, in order to validate them. The comparisons were performed using tissues taken form animals treated with different boron administration protocols. Subsequently the quantitative neutron autoradiography was employed to measure osteosarcoma cell samples treated with BPA and with new boronated formulations. © 2013 Published by Elsevier Ltd.

  10. Micro-electrodeposition techniques for the preparation of small actinide counting sources for ultra-high resolution alpha spectrometry by microcalorimetry

    International Nuclear Information System (INIS)

    Plionis, A.A.; Hastings, E.P.; LaMont, S.P.; Dry, D.E.; Bacrania, M.K.; Rabin, M.W.; Rim, J.H.

    2009-01-01

    Special considerations and techniques are desired for the preparation of small actinide counting sources. Counting sources have been prepared on metal disk substrates (planchets) with an active area of only 0.079 mm 2 . This represents a 93.75% reduction in deposition area from standard electrodeposition methods. The actinide distribution upon the smaller planchet must remain thin and uniform to allow alpha particle emissions to escape the counting source with a minimal amount of self-attenuation. This work describes the development of micro-electrodeposition methods and optimization of the technique with respect to deposition time and current density for various planchet sizes. (author)

  11. Procedure for the determination of uranium on cellulose air-sampling filters by photon-electron-rejecting-alpha-liquid-scintillation spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    McDowell, W.J.; Case, G.N.

    1986-08-01

    A procedure is described for obtaining from cellulose air-sampling filters the total uranium content whether it be in the form of metal, oxide, tetrafluoride or most other salts of uranium. It is demonstrated that the uranium content can be accurately assayed by low-temperature ashing of the filter paper, dissolving the ash in a mixed nitrate-sulfate system, extracting the uranium selectively into a scintillator containing a high-molecular-weight amine sulfate, and counting the extract using a Photon-Electron-Rejecting-Alpha-Liquid-Scintillation (PERALS) spectrometer. 2 refs., 4 figs., 2 tabs.

  12. Determination of zearalenone and its metabolites alpha- and beta-zearalenol in beer samples by high-performance liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Zöllner, P; Berner, D; Jodlbauer, J; Lindner, W

    2000-02-11

    A fast, robust and sensitive LC-MS-MS method for the determination of zearalenone (ZON) and its metabolites alpha-zearalenol (alpha-ZOL) and beta-zearalenol (beta-ZOL) in beer samples is described. Sample preparation was performed by direct RP-18 solid-phase extraction of undiluted beer samples followed by selective determination of analytes by LC-MS-MS applying an atmospheric pressure chemical ionization (APCI) interface. Using the negative ion mode limits of determination of 0.03-0.06 microg l(-1) beer and limits of quantification of 0.07-0.15 microg l(-1) beer were achieved, which was distinctly more sensitive than in the positive ion mode. Twenty-three beer samples from different countries, produced from different grains and under different brewing conditions, were investigated by this method, but only in one sample could beta-ZOL and ZON be detected. Independently of the type of beer, relative standard deviations between 2.1% and 3.3%, a linear working range of 0.15 microg l(-1) to 500 microg l(-1) beer and recovery rates around 100% could be achieved when zearalanone (ZAN) was used as internal standard.

  13. A Procedure for the Sequential Determination of Radionuclides in Phosphogypsum Liquid Scintillation Counting and Alpha Spectrometry for 210Po, 210Pb, 226Ra, Th and U Radioisotopes

    International Nuclear Information System (INIS)

    2014-01-01

    Since 2004, the Environment Programme of the IAEA has included activities aimed at the development of a set of procedures for the determination of radionuclides in terrestrial environmental samples. Reliable, comparable and 'fit for purpose' results are essential requirements for any decision based on analytical measurements. For the analyst, tested and validated analytical procedures are extremely important tools for the production of such analytical data. For maximum utility, such procedures should be comprehensive, clearly formulated, and readily available to both the analyst and the customer for reference. In this publication, a combined procedure for the sequential determination of 210Po, 210Pb, 226Ra, Th and U radioisotopes in phosphogypsum is described. The method is based on the dissolution of small amounts of phosphogypsum by microwave digestion, followed by sequential separation of 210Po, 210Pb, Th and U radioisotopes by selective extraction chromatography using Sr, TEVA and UTEVA resins. Radium-226 is separated from interfering elements using Ba(Ra)SO4 co-precipitation. Lead-210 is determined by liquid scintillation counting. The alpha source of 210Po is prepared by autodeposition on a silver plate. The alpha sources of Th and U are prepared by electrodeposition on a stainless steel plate. A comprehensive methodology for the calculation of results, including the quantification of measurement uncertainty, was also developed. The procedure is introduced as a recommended procedure and validated in terms of trueness, repeatability and reproducibility in accordance with ISO guidelines

  14. Identification of Clinical Streptococcus pneumoniae Isolates among other Alpha and Nonhemolytic Streptococci by Use of the Vitek MS Matrix-Assisted Laser Desorption Ionization–Time of Flight Mass Spectrometry System

    Science.gov (United States)

    Segonds, Christine; Prere, Marie-Françoise; Marty, Nicole; Oswald, Eric

    2013-01-01

    Discrimination between Streptococcus pneumoniae and its close relatives of the viridans group is a common difficulty in matrix-assisted laser desorption ionization–time of flight (MALDI-TOF) mass spectrometry-based identification. In the present study, the performances of the Vitek MS MALDI-TOF mass spectrometry system were assessed using 334 pneumococci, 166 other S. mitis group streptococci, 184 non-S. mitis group streptococci, and 19 related alpha- and nonhemolytic aerobic Gram-positive catalase-negative coccal isolates. Pneumococci had been identified by means of optochin susceptibility and bile solubility or serotyping, and other isolates mainly by use of RapidID32 Strep strips. In case of discordant or low-discrimination results, genotypic methods were used. The sensitivity of the Vitek MS for the identification of S. pneumoniae was 99.1%, since only three bile-insoluble isolates were misidentified as Streptococcus mitis/Streptococcus oralis. Conversely, two optochin-resistant pneumococci were correctly identified (specificity, 100%). Three Streptococcus pseudopneumoniae isolates were also correctly identified. Among nonpneumococcal isolates, 90.8% (n = 335) were correctly identified to the species or subspecies level and 2.4% (n = 9) at the group level. For the remaining 25 isolates, the Vitek MS proposed a bacterial species included in the list of possible species suggested by genotypic methods, except for 4 isolates which were not identified due to the absence of the species in the database. According to our study, the Vitek MS displays performance similar to that of the optochin susceptibility test for routine identification of pneumococcal isolates. Moreover, the Vitek MS is efficient for the identification of other viridans group streptococci and related isolates, provided that the species are included in the database. PMID:23576536

  15. A Procedure for the Sequential Determination of Radionuclides in Environmental Samples. Liquid Scintillation Counting and Alpha Spectrometry for 90Sr, 241Am and Pu Radioisotopes

    International Nuclear Information System (INIS)

    2014-01-01

    Since 2004, IAEA activities related to the terrestrial environment have aimed at the development of a set of procedures to determine radionuclides in environmental samples. Reliable, comparable and ‘fit for purpose’ results are an essential requirement for any decision based on analytical measurements. For the analyst, tested and validated analytical procedures are extremely important tools for the production of analytical data. For maximum utility, such procedures should be comprehensive, clearly formulated and readily available for reference to both the analyst and the customer. This publication describes a combined procedure for the sequential determination of 90 Sr, 241 Am and Pu radioisotopes in environmental samples. The method is based on the chemical separation of strontium, americium and plutonium using ion exchange chromatography, extraction chromatography and precipitation followed by alpha spectrometric and liquid scintillation counting detection. The method was tested and validated in terms of repeatability and trueness in accordance with International Organization for Standardization (ISO) guidelines using reference materials and proficiency test samples. Reproducibility tests were performed later at the IAEA Terrestrial Environment Laboratory. The calculations of the massic activity, uncertainty budget, decision threshold and detection limit are also described in this publication. The procedure is introduced for the determination of 90 Sr, 241 Am and Pu radioisotopes in environmental samples such as soil, sediment, air filter and vegetation samples. It is expected to be of general use to a wide range of laboratories, including the Analytical Laboratories for the Measurement of Environmental Radioactivity (ALMERA) network for routine environmental monitoring purposes

  16. Evaluation of uncertainty and detection limits in 210Pb and 210Po measurement in water by alpha spectrometry using 210Po spontaneous deposition onto a silver disk

    International Nuclear Information System (INIS)

    Fernández, Pedro L.; Gómez, José; Ródenas, Carmen

    2012-01-01

    An easy and accurate method for the determination of 210 Pb and 210 Po in water using 210 Po spontaneous deposition onto a silver disk is proposed and assessed for its detection capabilities according to the ISO Guide for the expression of uncertainty in measurement (GUM) and ISO Standard 11929-7 concerning the evaluation of the characteristic limits for ionizing radiation measurements. The method makes no assumption on the initial values of the activity concentrations of 210 Pb, 210 Bi and 210 Po in the sample to be analyzed, and is based on the alpha spectrometric measurement of 210 Po in two different aliquots: the first one measured five weeks after the sampling date to ensure radioactive equilibrium between 210 Pb and 210 Bi and the second after a sufficient time for the ingrowth of 210 Po from 210 Pb to be significant. As shown, for a recommended time interval of seven months between 210 Po measurements, the applicability of the proposed method is limited to water samples with a 226 Ra to 210 Pb activity ratio C Ra /C Pb ≤4, as usual in natural waters. Using sample and background counting times of 24 h and 240 h, respectively, the detection limit of the activity concentration of each radionuclide at the sampling time for a 1 L sample typically varies between 0.7 and 16 mBq L −1 for 210 Pb in water samples with an initial activity of 210 Po in the range 0–200 mBq L −1 , and between 0.6 and 8.5 mBq L −1 for 210 Po in water samples with an initial activity of 210 Pb in the same range. - Highlights: ► 210 Pb and 210 Po measurement in water by 210 Po spontaneous deposition onto silver disks. ► 210 Pb and 210 Po determination based on 210 Po measurement in two different aliquots. ► Evaluation of characteristic limits in radioactivity measurements using ISO 11929-7. ► 10 Pb - 210 Po detection limits decrease with time elapsed between 210 Po measurements.

  17. Contribution to the study of the {alpha} spectrometry by the impulse ionization chamber. Application to the study of the beam fine structure of some heavy nuclei; Contribution a l'etude de la spectrometrie {alpha} par la chambre d'ionisation a impulsion. Application a l'etude de la structure fine du rayonnement de quelques noyaux lourds

    Energy Technology Data Exchange (ETDEWEB)

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

    1954-05-15

    In the first part, it studies an impulse spectrometer of which the resolution and stability have been pushed to their maximum possibilities. It uses an ionization chamber because of its simple and steady functioning. The general characteristics and building of the ionization chamber are described. The electronic devices are described as well as the recording system. The theoretical study of the amplifier has allowed to reduce the amplitude dispersion from electronic devices as background noise. The resolution in energy of an {alpha} spectrometer using an impulse ionization chamber is studied and results are discussed. The spectral lines display of the fine structure under the effect of conversion electrons emitted by coincidence in the ionization chamber is studied. Finally, the detection possibilities of very low intensity spectral lines of fine structure of detection are considered. In the second part, the {alpha} emission of fine structure of {sup 230}Th, {sup 234}U and {sup 238}U nuclei is studied. (M.P.)

  18. Alpha sources deposit by sublimation

    International Nuclear Information System (INIS)

    Amoudry, F.; Eloy, J.F.

    1983-09-01

    We studied and realized a device able to perform some very thin substracts used for alpha spectrometry measurements. Sources are prepared by sublimation of the sample in a vacuum container. The energy required for this sublimation is furnished by a laser beam [fr

  19. Rapid quantification of alpha emitters in low- and intermediate-level dry radioactive waste

    International Nuclear Information System (INIS)

    Tae-Hong Park; Eul-Hye Jeon; Yong Sul Choi; Jong-Ho Park; Hong Joo Ahn; Yong Jun Park

    2016-01-01

    We developed a rapid quantification method of Pu, Am, and Cm in low- and intermediate-level radioactive waste using TRU resin, alpha spectrometry, and thermal ionization mass spectrometry for radioactive waste disposal. In particular, we focused on the optimization of sample preparation methods for alpha spectrometry and mass spectrometry to reduce the analysis time. The optimized method used Am and Pu stripping solutions for micro-coprecipitation and showed good recovery and alpha spectrum resolution for alpha counting. In addition, appropriate selection of Pu elution solution decreased the sample preparation time for thermal ionization mass spectrometry measurements. (author)

  20. Improved peak shape fitting in alpha spectra.

    Science.gov (United States)

    Pommé, S; Caro Marroyo, B

    2015-02-01

    Peak overlap is a recurrent issue in alpha-particle spectrometry, not only in routine analyses but also in the high-resolution spectra from which reference values for alpha emission probabilities are derived. In this work, improved peak shape formulae are presented for the deconvolution of alpha-particle spectra. They have been implemented as fit functions in a spreadsheet application and optimum fit parameters were searched with built-in optimisation routines. Deconvolution results are shown for a few challenging spectra with high statistical precision. The algorithm outperforms the best available routines for high-resolution spectrometry, which may facilitate a more reliable determination of alpha emission probabilities in the future. It is also applicable to alpha spectra with inferior energy resolution. Copyright © 2014 The Authors. Published by Elsevier Ltd.. All rights reserved.

  1. Determination of natural alpha-emitting isotopes of uranium and thorium in environmental and geological samples

    International Nuclear Information System (INIS)

    Crespo, M.T.

    1996-01-01

    It is described the complete radiochemical procedure used for the determination of uranium and thorium isotopes in environmental and geological samples by alpha spectrometry. Source preparation methods, alpha-counting and spectral analysis are also included

  2. Buffett's Alpha

    DEFF Research Database (Denmark)

    Frazzini, Andrea; Kabiller, David; Heje Pedersen, Lasse

    Berkshire Hathaway has realized a Sharpe ratio of 0.76, higher than any other stock or mutual fund with a history of more than 30 years, and Berkshire has a significant alpha to traditional risk factors. However, we find that the alpha becomes insignificant when controlling for exposures to Betting-Against-Beta...... in publicly traded stocks versus wholly-owned private companies, we find that the former performs the best, suggesting that Buffett's returns are more due to stock selection than to his effect on management. These results have broad implications for market efficiency and the implementability of academic...

  3. Improved peak shape fitting in alpha spectra

    OpenAIRE

    POMME Stefaan; CARO MARROYO BELEN

    2014-01-01

    Peak overlap is a recurrent issue ina lpha-particle spectrometry, not only in routine analyses but also in the high-resolution spectra from which reference values for alpha emission probabilities are derived. In this work, improved peak shape formulae are presented for the deconvolution of alpha-particle spectra. They have been implemented as fit functions in a spreadsheet application and optimum fit parameters were searched with built-in optimisation routines. Deconvolution results are shown...

  4. Spectrometry techniques for radioactivity measurements

    International Nuclear Information System (INIS)

    Anilkumar, S.

    2016-01-01

    The energy of the radiation emission following the nuclear decay is unique and the characteristic of the radio nuclide which undergoes decay. Thus measurement of the energy of the radiation offers a method of identifying the radio nuclides. The prime requirement of the energy measurement is a suitable detector which shows response proportional to the energy of the radiation rather than the presence of the radiation. The response from such detectors are suitably processed and distributed with respect to the signal strength which is proportional to incident energy. This distribution is normally referred as energy spectrum and is recorded in the multichannel analyser. The measurement of energy and intensity of radiation from the spectrum is called radiation spectrometry. Thus the radiation spectrometry allows the identification and quantification of radioactive isotopes in variety of matrices. The radiation spectrometry has now become a popular radioanalytical technique in wide area of nuclear fuel cycle programs. The popular spectrometry techniques commonly used for the radioactivity measurement and analysis are Alpha spectrometry, Gamma ray spectrometry and Beta spectrometry

  5. Measurement of radon daughters in air samples by alpha spectroscopy

    International Nuclear Information System (INIS)

    Acena, M.L.; Crespo, M.T.

    1989-01-01

    The concentration of radon progeny in air has been determined by alpha spectrometry measurement of polonium 214 and polonium 218. A known volume of air was passed through a filter, then the alpha activity was directly measured on this filter (Author)

  6. Numerical analysis of alpha spectra using two different codes

    International Nuclear Information System (INIS)

    Hurtado, S.; Jimenez-Ramos, M.C.; Villa, M.; Vioque, I.; Manjon, G.; Garcia-Tenorio, R.

    2008-01-01

    This work presents an intercomparison between commercial software for alpha-particle spectrometry, Genie 2000, and the new free available software, Winalpha, developed by International Atomic Energy Agency (IAEA). In order to compare both codes, different environmental spectra containing plutonium, uranium, thorium and polonium have been analyzed, together with IAEA test alpha spectra. A statistical study was performed in order to evaluate the precision and accuracy in the analyses, and to enhance the confidence in using the software on alpha spectrometric studies

  7. Elimination of alpha-gal xenoreactive epitope: alpha-galactosidase treatment of porcine heart valves.

    Science.gov (United States)

    Choi, Sun-Young; Jeong, Hee-Jin; Lim, Hong-Gook; Park, Seong-Sik; Kim, Soo-Hwan; Kim, Yong Jin

    2012-05-01

    Porcine heart valves are among the most widely used tissue valves in clinical heart valve implantation. However, immunologic responses have been implicated as potential causes of the limited durability of xenograft heart valves. The study aim was to determine the effectiveness of alpha-galactosidase treatment used to degrade the major xenoreactive antigens found in xenograft heart valves. Fresh porcine heart valves and pericardium treated with alpha-galactosidase were studied to evaluate the xenoreactive galactose (alpha1,3) galactose (alpha-gal) antigen. Removal of the alpha-gal epitope from the porcine heart valve was monitored via 3,3'-diaminobenzidine staining intensity, while the removal of alpha-gal from N-glycans on porcine heart valves treated with recombinant alpha-galactosidase was determined either qualitatively or quantitatively by mass fingerprinting using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). The porcine pericardium was used for monitoring the change in mechanical properties after alpha-galactosidase treatment. In addition, the biomechanical modification property of collagen fiber rearrangement on tissue was assessed using transmission electron microscopy (TEM). Following a 24-h incubation at pH 7.2, 4 degrees C, employing 0.1 U/ml of Bacteroides thetaiotaomicron-derived recombinant alpha-galactosidase, the enzyme effectively removed the alpha-gal epitopes expressed on porcine heart valves. The identification type of alpha-gal N-glycan on fresh aortic valve, aortic wall, pulmonary valve, and pulmonary wall was 7.1%, 10.3%, 6% and 8%, respectively. In the presence of alpha-galactosidase treatment, alpha-gal-containing N-glycans were converted into alpha-gal-negative N-glycans. Likewise, alpha-gal-containing N-glycans were not detected when MALDI-TOF MS quantitative analysis was used. Furthermore, no significant difference was observed in the mechanical properties and findings from TEM in alpha

  8. Coulomb correction to elastic. alpha. -. alpha. scattering

    Energy Technology Data Exchange (ETDEWEB)

    Bera, P.K.; Jana, A.K.; Haque, N.; Talukdar, B. (Department of Physics, Visva-Bharati University, Santiniketan-731235, West Bengal, India (IN))

    1991-02-01

    The elastic {alpha}-{alpha} scattering is treated within the framework of a generalized phase-function method (GPFM). This generalization consists in absorbing the effect of Coulomb interaction in the comparison functions for developing the phase equation. Based on values of scattering phase shifts computed by the present method, it is concluded that the GPFM provides an uncomplicated approach to rigorous Coulomb correction in the {alpha}-{alpha} scattering.

  9. Intrahepatic expression of interferon alpha & interferon alpha ...

    African Journals Online (AJOL)

    kemrilib

    Alpha m-RNA while 30% only expressed Interferon Alpha Receptor m-RNA. Responders and non-responders to Interferon therapy ... expression of IFN Alpha Receptor mRNA. Regardless of the response to interferon, histological .... generation reverse hybridisation, line probe assay. (Inno-LiPA HCV II; Innogenetics, Ghent,.

  10. Mass spectrometry

    DEFF Research Database (Denmark)

    Nyvang Hartmeyer, Gitte; Jensen, Anne Kvistholm; Böcher, Sidsel

    2010-01-01

    Matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) is currently being introduced for the rapid and accurate identification of bacteria. We describe 2 MALDI-TOF MS identification cases - 1 directly on spinal fluid and 1 on grown bacteria. Rapidly obtained...

  11. Liquid chromatography-high resolution mass spectrometry with immunoaffinity clean-up for the determination of the oxidative stress biomarker 8-iso-prostaglandin F2alpha in wastewater.

    Science.gov (United States)

    Ryu, Yeonsuk; Reid, Malcolm J; Thomas, Kevin V

    2015-08-28

    A reliable oxidative stress biomarker, 8-iso-prostaglandin F2α (8-iso-PGF2α), was for the first time quantitatively analysed in wastewater using an analytical method consisting of liquid chromatography-high resolution mass spectrometry coupled to immunoaffinity clean-up (IAC-LC-HRMS). Factors influencing the method's robustness were investigated, including analyte stability in sewage and enzymatic deconjugation with β-glucuronidase. The IAC-LC-HRMS method was linear over the range of 0.1-100ng/mL with correlation coefficient (R(2)) of 0.999. The quantification limits were sufficiently low to detect 8-iso-PGF2α in sewage (method quantification limit of 0.3ng/L) and precision, expressed as relative standard deviation was less than 7% and the accuracy expressed as relative recovery was in the 103-113% range. As a result, the application of the method to 24-h composite wastewater samples from Oslo showed 8-iso-PGF2α concentrations of 18.9-23.3ng/L for 8 days in March 2015. This study demonstrates a standard method to analyse 8-iso-PGF2α in sewage that will contribute to the further investigation of the potential use of 8-iso-PGF2α as a sewage biomarker for assessing the status of community health. Copyright © 2015 Elsevier B.V. All rights reserved.

  12. Application of atomic and nuclear techniques to the study of inhomogeneities in electrodeposited {alpha}-particle sources

    Energy Technology Data Exchange (ETDEWEB)

    Martin Sanchez, A. E-mail: ams@unex.es; Nuevo, M.J.; Jurado Vargas, M.; Diaz Bejarano, J.; Silva, M.F. da; Roldan Garcia, C.; Paul, A.; Ferrero Calabuig, J.L.; Mendez Vilas, A.; Juanes Barber, D

    2002-05-01

    Three {alpha}-particle sources made by different methods of electrodeposition were analysed using {alpha}-particle spectrometry, Rutherford backscattering (RBS), and atomic force microscopy (AFM) on several surface zones. The thickness and homogeneity of these sources was studied using RBS, and the results were analysed jointly with those obtained with {alpha}-particle spectrometry and AFM techniques. The comparison of the electrodeposition methods showed that the most homogeneous electrodeposited zones corresponded to the source made with a stirring cathode.

  13. Liquid-scintillation alpha-detection techniques

    International Nuclear Information System (INIS)

    McKlveen, J.W.; McDowell, W.J.

    1983-01-01

    Accurate, quantitative determinations of alpha-emitting nuclides by conventional plate-counting methods are difficult because of sample self-absorption problems in counting and because of non-reproducible losses in conventional sample separation methods. Liquid scintillation alpha spectrometry offers an attractive with no sample self-absorption or geometry problems and with 100% counting efficiency. Sample preparation may include extraction of the alpha emitter of interest by a specific organic-phase-soluble compound directly into the liquid scintillation counting medium. Detection electronics use energy and pulse-shape discrimination to yield alpha spectra without beta and gamma background interference. Specific procedures have been developed for gross alpha, uranium, plutonium, thorium, and polonium assay. Possibilities for a large number of other applications exist. Accuracy and reproducibility are typically in the 1% range. Backgrounds on the order of 0.01 cpm are readily achievable. The paper will present an overview of liquid scintillation alpha counting techniques and some of the results achieved for specific applications

  14. [Mass spectrometry of triterpene glycosides molecular complexation with purine bases of nucleic acids].

    Science.gov (United States)

    Lekar', A V; Vetrova, E V; Borisenko, N I; Iakovishin, L A; Grishkovets, V I

    2011-01-01

    The molecular complexation of adenine and guanine with hederagenin 3-O-alpha-L-rhamnopyranosyl-(1-->2)-O-alpha-L-arabinopyranoside (alpha-hederin) and its 28-O-alpha-L-rhamnopyranosyl-(1-->4)-O-beta-D-glucopyranosyl-(1-->6)-O-beta-D-glucopyranosyl ester (hederasaponin C) was investigated for the first time using the method of electrospray ionization mass spectrometry. Guanine forms complexes more diverse in composition than adenine.

  15. Determination of curium-242 by α spectrometry and mass spectrometry in spent nuclear fuels

    International Nuclear Information System (INIS)

    Chartier, F.; Aubert, M.; Degros, J.P.; Duda, J.M.

    2004-01-01

    Curium-242 is a particularly important isotope in spent nuclear fuels due to its contribution to the residual power and also of its radioactive decrease chain. The determination of its content is therefore essential to improve the knowledge of the nuclear data. According to the nature and the cooling time of the spent fuel, the 242 Cm content can be lower than the detection limit of the classically used mass spectrometric techniques. To overcome this limitation, alpha spectrometry can be advantageously used for this radionuclide of short period (T = 162.9 days). From dilute solutions of MOX fuels of short time of cooling and for which the content of 242 Cm is about a few tens of pg, the development of different successive chemical separations permitted to get sufficiently pure curium fractions to perform curium isotopic analysis by thermal ionization mass spectrometry but also the determination of the 242 Cm/ 244 Cm ratio by alpha spectrometry. The agreement on the ratios determined by the two techniques has allowed to spread the measure by alpha spectrometry to a UOX fuel of content in 242 Cm even lower. The association of the 242 Cm/ 244 Cm ratio measurement with the 244 Cm/ 238 U ratio obtained by thermal ionization mass spectrometry and isotope dilution, with a 248 Cm/ 233 U spike, permits to know the content in curium-242 in relation to uranium-238 which is used as a reference in the fuel. (author)

  16. The determination of $\\alpha_s$ by the ALPHA collaboration

    CERN Document Server

    Bruno, Mattia

    2016-01-01

    We review the ALPHA collaboration strategy for obtaining the QCD coupling at high scale. In the three-flavor effective theory it avoids the use of perturbation theory at $\\alpha > 0.2$ and at the same time has the physical scales small compared to the cutoff $1/a$ in all stages of the computation. The result $\\Lambda_\\overline{MS}^{(3)}=332(14)$~MeV is translated to $\\alpha_\\overline{MS}(m_Z)=0.1179(10)(2)$ by use of (high order) perturbative relations between the effective theory couplings at the charm and beauty quark "thresholds". The error of this perturbative step is discussed and estimated as $0.0002$.

  17. Spatio-temporal profiling and degradation of alpha-amylase isozymes during barley seed germination

    DEFF Research Database (Denmark)

    Bak-Jensen, K.S.; Laugesen, Sabrina; Østergaard, Ole

    2007-01-01

    Ten genes from two multigene families encode barley alpha-amylases. To gain insight into the occurrence and fate of individual isoforms during seed germination, the alpha-amylase repertoire was mapped by using a proteomics approach consisting of 2D gel electrophoresis, western blotting, and mass...... spectrometry. Mass spectrometric analysis confirmed that the 29 alpha-amylase positive 2D gel spots contained products of one ( GenBank accession gi| 113765) and two ( gi vertical bar 4699831 and gi vertical bar 166985) genes encoding alpha-amylase 1 and 2, respectively, but lacked products from seven other...... genes. Eleven spots were identified only by immunostaining. Mass spectrometry identified 12 full-length forms and 12 fragments from the cultivar Barke. Products of both alpha-amylase 2 entries co-migrated in five full-length and one fragment spot. The alpha-amylase abundance and the number of fragments...

  18. Gas chromatography-mass spectrometry (GC-MS) and liquid chromatography-mass spectrometry (LC-MS) in toxicological analysis. Studies on the detection of clobenzorex and its metabolites within a systematic toxicological analysis procedure by GC-MS and by immunoassay and studies on the detection of alpha- and beta-amanitin in urine by atmospheric pressure ionization electrospray LC-MS.

    Science.gov (United States)

    Maurer, H H; Kraemer, T; Ledvinka, O; Schmitt, C J; Weber, A A

    1997-02-07

    GC-MS is the method of choice for toxicological analysis of toxicants volatile in GC while non-volatile and/or thermally labile toxicants need LC-MS for their determination. Studies are presented on the toxicological detection of the amphetamine-like anorectic clobenzorex in urine by GC-MS after acid hydrolysis, extraction and acetylation and by fluorescence polarization immunoassay (FPIA, TDx (meth)amphetamine II). After ingestion of 60 mg of clobenzorex, the parent compound and/or its metabolites could be detected by GC-MS for up to 84 h or by FPIA for up to 60 h. Since clobenzorex shows no cross-reactivity with the used immunoassay, the N-dealkylated metabolite amphetamine is responsible for the positive TDx results. The intake of clobenzorex instead of amphetamine can be differentiated by GC-MS detection of hydroxyclobenzorex which is detectable for at least as long as amphetamine. In addition, the described GC-MS procedure allows the simultaneous detection of most of the toxicologically relevant drugs. Furthermore, studies are described on the atmospheric pressure ionization electrospray LC-MS detection of alpha- and beta-amanitin, toxic peptides of amanita mushrooms, in urine after solid-phase extraction on RP-18 columns. Using the single ion monitoring mode with the ions m/z 919 and 920 the amanitins could be detected down to 10 ng/ml of urine which allows us to diagnose intoxications with amanita mushrooms.

  19. Lyman Alpha Control

    CERN Document Server

    Nielsen, Daniel Stefaniak

    2015-01-01

    This document gives an overview of how to operate the Lyman Alpha Control application written in LabVIEW along with things to watch out for. Overview of the LabVIEW code itself as well as the physical wiring of and connections from/to the NI PCI-6229 DAQ box is also included. The Lyman Alpha Control application is the interface between the ALPHA sequencer and the HighFinesse Wavelength Meter as well as the Lyman Alpha laser setup. The application measures the wavelength of the output light from the Lyman Alpha cavity through the Wavelength Meter. The application can use the Wavelength Meter’s PID capabilities to stabilize the Lyman Alpha laser output as well as switch between up to three frequencies.

  20. New ALPHA-2 magnet

    CERN Multimedia

    Anaïs Schaeffer

    2012-01-01

    On 21 June, members of the ALPHA collaboration celebrated the handover of the first solenoid designed for the ALPHA-2 experiment. The magnet has since been successfully installed and is working well.   Khalid Mansoor, Sumera Yamin and Jeffrey Hangst in front of the new ALPHA-2 solenoid. “This was the first of three identical solenoids that will be installed between now and September, as the rest of the ALPHA-2 device is installed and commissioned,” explains ALPHA spokesperson Jeffrey Hangst. “These magnets are designed to allow us to transfer particles - antiprotons, electrons and positrons - between various parts of the new ALPHA-2 device by controlling the transverse size of the particle bunch that is being transferred.” Sumera Yamin and Khalid Mansoor, two Pakistani scientists from the National Centre for Physics in Islamabad, came to CERN in February specifically to design and manufacture these magnets. “We had the chance to work on act...

  1. Plutonium determination in urine by techniques of mass spectrometry

    International Nuclear Information System (INIS)

    Hernandez M, H.; Yllera de Ll, A.

    2013-10-01

    The objective of this study was to develop an analytic method for quantification and plutonium reappraisal in plane tables of alpha spectrometry be means of the mass spectrometry technique of high resolution with plasma source inductively coupled and desolvator Aridus (Aridus-Hr-Icp-Ms) and mass spectrometry with accelerator (AMS). The obtained results were, the recovery percentage of Pu in the plane table was of ∼ 90% and activity minimum detectable obtained with Aridus-Hr-Icp-Ms and AMS was of ∼ 3 and ∼ 0.4 f g of 239 Pu, respectively. Conclusion, the results demonstrate the aptitude of the Aridus-Hr-Icp-Ms and AMS techniques in the Pu reappraisal in plane tables with bigger speed and precision, improving the values notably of the activity minimum detectable that can be obtained with the alpha spectrometry (∼ 50 f g of 239 Pu). (author)

  2. Quantification of active infliximab in human serum with liquid chromatography-tandem mass spectrometry using a tumor necrosis factor alpha -based pre-analytical sample purification and a stable isotopic labeled infliximab bio-similar as internal standard: A target-based, sensitive and cost-effective method.

    Science.gov (United States)

    El Amrani, Mohsin; van den Broek, Marcel P H; Göbel, Camiel; van Maarseveen, Erik M

    2016-07-08

    The therapeutic monoclonal antibody Infliximab (IFX) is a widely used drug for the treatment of several inflammatory autoimmune diseases. However, approximately 10% of patients develop anti-infliximab antibodies (ATIs) rendering the treatment ineffective. Early detection of underexposure to unbound IFX would result in a timely switch of therapy which could aid in the treatment of this disease. Streptavidin coated 96 well plates were used to capture biotinylated-tumor necrosis factor -alpha (b-TNF-α), which in turn was used to selectively extract the active form of IFX in human serum. After elution, IFX was digested using trypsin and one signature peptide was selected for subsequent analysis on liquid chromatography-tandem mass spectrometry (LC-MS/MS). The internal standard used was a stable isotopic labeled IFX bio-similar. The assay was successfully validated according to European Medicines Agency (EMA) guidelines and was found to be linear in a range of 0.5-20μg/mL (r(2)=0.994). Lower limit of quantification for the assay (<20% CV) was 0.5μg/mL, requiring only 2μL of sample. Cross-validation against enzyme-linked immunosorbent assay (ELISA) resulted in a high correlation between methods (r(2)=0.95 with a ρc=0.83) and the accuracy was in line with previously published results. In conclusion, a sensitive, robust and cost-effective method was developed for the bio-analysis of IFX with LC-MS/MS by means of a target-based pre-analytical sample purification. Moreover, low volume and costs of consumables per sample promote its feasibility in (pre)clinical studies and in therapeutic drug monitoring. This method should be considered as first choice due to its accuracy and multiple degree of selectivity. Copyright © 2016 Elsevier B.V. All rights reserved.

  3. Alpha Shapes and Proteins

    DEFF Research Database (Denmark)

    Winter, Pawel; Sterner, Henrik; Sterner, Peter

    2009-01-01

    We provide a unified description of (weighted) alpha shapes, beta shapes and the corresponding simplicialcomplexes. We discuss their applicability to various protein-related problems. We also discuss filtrations of alpha shapes and touch upon related persistence issues.We claim that the full...... potential of alpha-shapes and related geometrical constructs in protein-related problems yet remains to be realized and verified. We suggest parallel algorithms for (weighted) alpha shapes, and we argue that future use of filtrations and kinetic variants for larger proteins will need such implementation....

  4. Application of Micro-coprecipitation Method to Alpha Source Preparation for Measuring Alpha Nuclides

    International Nuclear Information System (INIS)

    Lee, Myung Ho; Park, Jong Ho; Oh, Se Jin; Song, Byung Chul; Song, Kyuseok

    2011-01-01

    Among the source preparations, an electrodeposition is a commonly used method for the preparation of sources for an alpha spectrometry, because this technique is simple and produces a very thin deposit, which is essential for a high resolution of the alpha peak. Recently, micro-coprecipitation with rare earths have been used to yield sources for -spectrometry. In this work, the Pu, Am and Cm isotopes were purified from hindrance nuclides and elements with an a TRU resin in radioactive waste samples, and the activity concentrations of the Pu, Am and Cm isotopes were determined by radiation counting methods after alpha source preparation like micro coprecipitation. After the Pu isotopes in the radioactive waste samples were separated from the other nuclides with an anion exchange resin, the Am isotopes were purified with a TRU resin and an anion exchange resin or a TRU resin. Activity concentrations and chemical recoveries of 241 Am purified with the TRU resin were similar to those with the TRU resin and anion exchange resin. In this study, to save on the analytical time and cost, the Am isotopes were purified with the TRU resin without using an additional anion exchange resin. After comparing the electrodeposition method with the micro-coprecipitation method, the micro-coprecipitation method was used for the alpha source preparation, because the micro-coprecipitation method is simple and more reliable for source preparation of the Pu, Am and Cm isotopes

  5. Targeted Alpha Therapy: From Alpha to Omega

    International Nuclear Information System (INIS)

    Allen, Barry J; Clarke, Raymond; Huang Chenyu

    2013-01-01

    This review covers the broad spectrum of Targeted Alpha Therapy (TAT) research in Australia; from in vitro and in vivo studies to clinical trials. The principle of tumour anti-vascular alpha therapy (TAVAT) is discussed in terms of its validation by Monte Carlo calculations of vascular models and the potential role of biological dosimetry is examined. Summmary of this review is as follows: 1. The essence of TAT 2. Therapeutic objectives 3. TAVAT and Monte Carlo microdosimetry 4. Biological dosimetry 5. Preclinical studies 6. Clinical trials 7. What next? 8. Obstacles. (author)

  6. Alpha1-antitrypsin deficiency

    DEFF Research Database (Denmark)

    Stolk, Jan; Seersholm, Niels; Kalsheker, Noor

    2006-01-01

    The Alpha One International Registry (AIR), a multinational research program focused on alpha1-antitrypsin (AAT) deficiency, was formed in response to a World Health Organization recommendation. Each of the nearly 20 participating countries maintains a national registry of patients with AAT defic...... epidemiology, inflammatory and signalling processes, therapeutic advances, and lung imaging techniques....

  7. Alpha clustering in nuclei

    International Nuclear Information System (INIS)

    Hodgson, P.E.

    1990-01-01

    The effects of nucleon clustering in nuclei are described, with reference to both nuclear structure and nuclear reactions, and the advantages of using the cluster formalism to describe a range of phenomena are discussed. It is shown that bound and scattering alpha-particle states can be described in a unified way using an energy-dependent alpha-nucleus potential. (author)

  8. Nanocrystalline alpha-Fe Layer Examined by Mossbauer Spectrometry

    Czech Academy of Sciences Publication Activity Database

    David, Bohumil; Schneeweiss, Oldřich; Pizúrová, Naděžda; Rek, Antonín; Kudrle, V.; Jašek, J.

    2014-01-01

    Roč. 126, č. 1 (2014), s. 94-95 ISSN 0587-4246. [CSMAG Czech and Slovak Conference on Magnetism /15./. Košice, 17.06.2013-21.06.2013] R&D Projects: GA MŠk(CZ) ED1.1.00/02.0068 Institutional support: RVO:68081723 ; RVO:68081731 Keywords : nanostructured pure iron * microwave plasma * Mossbauer spectroscopy * TEM * SEM Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 0.530, year: 2014 http://przyrbwn.icm.edu.pl/ APP /PDF/126/a126z1p043.pdf

  9. Equilibria determination in uranium ores by alpha spectrometry

    International Nuclear Information System (INIS)

    Tormo Ferrero, M.J.

    1976-01-01

    A method for the measurement of the U-234/U-238 activities is described. The separation of the uranium from the interferring elements is carried out by ionic change with anionic resine, in chlorhydric-metanol-ascorbic acid medium. The method has been applied to different spanish ores in which the equilibrium state has been determined (author)

  10. Genetics Home Reference: alpha thalassemia

    Science.gov (United States)

    ... Facebook Twitter Home Health Conditions Alpha thalassemia Alpha thalassemia Printable PDF Open All Close All Enable Javascript to view the expand/collapse boxes. Description Alpha thalassemia is a blood disorder that reduces the production ...

  11. Elevated levels of serum alpha(2) macroglobulin in wild black bears during hibernation.

    Science.gov (United States)

    Sheikh, Ashfaq M; Chauhan, Ved; Tsiouris, John A; Mehta, Pankaj D; Burguess, Kelcey; Fenko, Michael D; Spivack, Warren; Vaughan, Michael; Malik, Mazhar

    2003-10-01

    Bear serum alpha(2) macroglobulin (alpha(2)M) was purified by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and partially characterized by tryptic digestion of alpha(2)M and analysis of the peptides by peptide mass fingerprinting. The molecular weight of bear serum alpha(2)M was 181 kDa, same as for human serum alpha(2)M, on SDS-PAGE. However, the MALDI mass spectrum of the tryptic digested bear serum alpha(2)M showed that it is different from human alpha(2)M or other data bank proteins. Liquid chromatography (LC)/mass spectrometry (MS)/MS of the proteolytic products of bear serum alpha(2)M showed eight peptides that had similarities to human alpha(2)M suggesting that the protein of interest was indeed alpha(2)M of bear. The polyclonal antibody against bear serum alpha(2)M recognized only one protein from the western blot of bear serum proteins. It also recognized human alpha(2)M. The levels of serum alpha(2)M were significantly increased during hibernating state as compared to active state of bears indicating its protective role from the consequences of the metabolic depression during hibernation.

  12. Determining Some Parameters Of Uranium Material By GAMMA Spectrometry Using Intrinsic Efficiency Calibration

    International Nuclear Information System (INIS)

    Le Tuan Anh; Bui Minh Hue; Bui Van Loat; Nguyen Cong Tam

    2011-01-01

    Abundance and age of uranium material are two significant parameters. Traditionally, they are determined by alpha spectrometry and mass-spectrometry, which are destructive methods. In this report, we exhibit the result of abundance and age, which were determined by gamma-spectrometry using intrinsic efficiency calibration. This is a nondestructive method without using standard source or any reference samples, and applicable to material of any geometrical shape. The result obtained is in good agreement with the results obtained by other authors. (author)

  13. Rapid method for the sequential measurement of isotopes of Am and Pu in liquid matrices by alpha spectrometry; Método rápido para la medida secuencial de isótopos de Am y Pu en matrices líquidas por espectrometría alfa

    Energy Technology Data Exchange (ETDEWEB)

    Mantero Cabrera, J.

    2014-07-01

    : In radiological emergencies it's necessary a fast response from the laboratories in the quantification of certain radionuclides, in order to take decisions. In these cases, is the reaction time the key parameter to consider (without neglecting the quality of the measurement). In this work, it is shown a method for aqueous matrices that generates Pu and Am isotopes sources in one single day of work, to be measured subsequently by alpha spectrometry. The developed methodology has been validated through its application to reference samples and also taking part intercom- parison exercises, having in both cases, satisfactory results. This way, we check the validity of this fast method that let us generate in 24 hours (since the sample arrives our laboratory), one measurement with a Minimun Detectable Activity (MDA) of about 0.004Bq/L for Pu and Am isotopes in liquid matrices. [Spanish] En situaciones de emergencia radiológica es muy común la necesidad de dar una respuesta rápida por parte de los laboratorios en la cuantificación de ciertos radionucleidos, de cara a la toma de decisiones. En estos casos, el tiempo de reacción es una variable fundamental a considerar (aunque obviamente sin dejar de lado la calidad en el resultado de la medida). En este trabajo se presenta un método para matrices acuosas que permite generar en una única jornada de trabajo, las fuentes de medida necesarias en la detección de isótopos de Pu y Am para ser medidas con posterioridad por espectrometría alfa. La metodología puesta a punto ha sido validada mediante su aplicación a muestras de referencia y mediante la participación en ejercicios de intercomparación, en ambos casos, con resultados satisfactorios. Queda así demostrada la validez de este método rápido que nos permite generar en 24 horas desde la recepción de la muestra, una medida en nuestros sistemas con una Actividad Mínima Detectable (AMD) de 0.004 Bq/L tanto para isótopos de Pu (238Pu, 239+240Pu) como de

  14. Alpha Thalassemia (For Parents)

    Science.gov (United States)

    ... the body has a problem producing alpha globin Beta thalassemia : when the body has a problem producing beta ... Transfusion Blood Test: Hemoglobin Electrophoresis Sickle Cell Disease Beta Thalassemia Blood All About Genetics Prenatal Genetic Counseling Genetic ...

  15. ALPHA-2: the sequel

    CERN Multimedia

    Katarina Anthony

    2012-01-01

    While many experiments are methodically planning for intense works over the long shutdown, there is one experiment that is already working at full steam: ALPHA-2. Its final components arrived last month and will completely replace the previous ALPHA set-up. Unlike its predecessor, this next generation experiment has been specifically designed to measure the properties of antimatter.   The ALPHA team lower the new superconducting solenoid magnet into place. The ALPHA collaboration is working at full speed to complete the ALPHA-2 set-up for mid-November – this will give them a few weeks of running before the AD shutdown on 17 December. “We really want to get some experience with this device this year so that, if we need to make any changes, we will have time during the long shutdown in which to make them,” says Jeffrey Hangst, ALPHA spokesperson. “Rather than starting the 2014 run in the commissioning stage, we will be up and running from the get go.&...

  16. Expression of triplicated and quadruplicated alpha globin genes in sheep.

    Science.gov (United States)

    Vestri, R; Pieragostini, E; Yang, F; di Gregorio, P; Rando, A; Masina, P

    1991-01-01

    In the sheep alpha alpha alpha globin gene haplotype, the three genes display from the 5' to the 3' end the percentage efficiencies of about 30:14:6, as indicated by the amounts of the three types of alpha chain produced in the alpha alpha alpha/alpha alpha alpha homozygotes. The 3' gene in the alpha alpha alpha alpha haplotype appears to have an efficiency around 1%, as suggested by analysis of one quadruple alpha homozygote. Moreover, the total outputs of the alpha alpha alpha as well as of the alpha alpha alpha alpha haplotypes do not substantially differ from that of the common alpha alpha haplotype.

  17. Monte Carlo alpha calculation

    Energy Technology Data Exchange (ETDEWEB)

    Brockway, D.; Soran, P.; Whalen, P.

    1985-01-01

    A Monte Carlo algorithm to efficiently calculate static alpha eigenvalues, N = ne/sup ..cap alpha..t/, for supercritical systems has been developed and tested. A direct Monte Carlo approach to calculating a static alpha is to simply follow the buildup in time of neutrons in a supercritical system and evaluate the logarithmic derivative of the neutron population with respect to time. This procedure is expensive, and the solution is very noisy and almost useless for a system near critical. The modified approach is to convert the time-dependent problem to a static ..cap alpha../sup -/eigenvalue problem and regress ..cap alpha.. on solutions of a/sup -/ k/sup -/eigenvalue problem. In practice, this procedure is much more efficient than the direct calculation, and produces much more accurate results. Because the Monte Carlo codes are intrinsically three-dimensional and use elaborate continuous-energy cross sections, this technique is now used as a standard for evaluating other calculational techniques in odd geometries or with group cross sections.

  18. Monte Carlo alpha deposition

    International Nuclear Information System (INIS)

    Talley, T.L.; Evans, F.

    1988-01-01

    Prior work demonstrated the importance of nuclear scattering to fusion product energy deposition in hot plasmas. This suggests careful examination of nuclear physics details in burning plasma simulations. An existing Monte Carlo fast ion transport code is being expanded to be a test bed for this examination. An initial extension, the energy deposition of fast alpha particles in a hot deuterium plasma, is reported. The deposition times and deposition ranges are modified by allowing nuclear scattering. Up to 10% of the initial alpha particle energy is carried to greater ranges and times by the more mobile recoil deuterons. 4 refs., 5 figs., 2 tabs

  19. Buffett’s Alpha

    DEFF Research Database (Denmark)

    Frazzini, Andrea; Kabiller, David; Heje Pedersen, Lasse

    Berkshire Hathaway has realized a Sharpe ratio of 0.76, higher than any other stock or mutual fund with a history of more than 30 years, and Berkshire has a significant alpha to traditional risk factors. However, we find that the alpha becomes insignificant when controlling for exposures to Betting......-Against-Beta and Quality-Minus-Junk factors. Further, we estimate that Buffett’s leverage is about 1.6-to-1 on average. Buffett’s returns appear to be neither luck nor magic, but, rather, reward for the use of leverage combined with a focus on cheap, safe, quality stocks. Decomposing Berkshires’ portfolio into ownership...

  20. Maduramicin. alpha. : Characterization of sup 14 C-derived residues in turkey excreta

    Energy Technology Data Exchange (ETDEWEB)

    Stout, S.J.; daCunha, A.R.; Lee, A. (American Cyanamid Co., Princeton, NJ (United States)); Jinn Wu; King, K.G. (XenoBiotic Labs., Inc., Princeton, NJ (United States))

    1991-02-01

    Maduramicin {alpha}, a highly potent polyether ionophore antibiotic for preventing coccidiosis in poultry, is passed predominantly in turkey excreta following oral feeding. Following isolation and purification, the turkey excreta metabolites were characterized primarily by liquid chromatography/mass spectrometry and liquid chromatography/tandem mass spectrometry. Maduramicin {alpha} and its metabolites generate a characteristic pair of ions corresponding to (M + NH{sub 4}){sup +} and (M + Na){sup +} which assist in differentiating the metabolites from matrix coextractives. These two ions also fragment differently in tandem mass spectrometry, thus providing structural information for characterizing the nature of unknown metabolites. The primary metabolic pathway of maduramicin {alpha} in the turkey is O-demethylation at one or more of the methoxy groups. Hydroxylation and glucuronide conjugation are minor secondary metabolic processes.

  1. Case Study - Alpha

    Directory of Open Access Journals (Sweden)

    Stephen Leybourne

    2016-11-01

    Full Text Available This case study was developed from an actual scenario by Dr. Steve Leybourne of Boston University.  The case documents the historical evolution of an organization, and has been used successfully in courses dealing with organizational and cultural change, and the utilization of ‘soft skills’ in project-based management. This is a short case, ideal for classroom use and discussion.  The issues are easily accessible to students, and there is a single wide ranging question that allows for the inclusion of many issues surrounding strategic decision-making, and behavioural and cultural change. Alpha was one of the earlier companies in the USA to invest in large, edge-of-town superstores, with plentiful free vehicle parking, selling food and related household products. Alpha was created in the 1950s as a subsidiary of a major publicly quoted retail group.  It started business by opening a string of very large discount stores in converted industrial and warehouse premises in the south of the United States. In the early days shoppers were offered a limited range of very competitively priced products. When Alpha went public in 1981 it was the fourth largest food retailer in the US, selling an ever-widening range of food and non-food products.  Its success continued to be based on high volume, low margins and good value for money, under the slogan of ‘Alpha Price.’

  2. Alpha-mannosidosis

    DEFF Research Database (Denmark)

    Borgwardt, Line; Stensland, Hilde Monica Frostad Riise; Olsen, Klaus Juul

    2015-01-01

    of the three subgroups of genotype/subcellular localisation and the clinical and biochemical data were done to investigate the potential relationship between genotype and phenotype in alpha-mannosidosis. Statistical analyses were performed using the SPSS software. Analyses of covariance were performed...

  3. Improved Isotopic Measurement of Plutonium by Thermal Ionization Mass Spectrometry

    International Nuclear Information System (INIS)

    Shick, C. Jr.

    2002-01-01

    Thermal ionization mass spectrometry (TIMS) is accepted widely as the benchmark method for precise and accurate isotopic determination of plutonium. TIMS is one of the few analytical methods capable of determining Pu in bioassay samples at the level required for detecting a 50 yr committed dose of 100 mRem resulting from an inhalation exposure to highly insoluble forms of Pu. Typically, Pu is measured in bioassay samples by radiochemical separation, electrodeposition onto a planchet, and radiometric determination by alpha spectrometry. If, based on the alpha spectrometry results, a sample is deemed to need a more sensitive analysis (i.e. suspected uptake, borderline alpha spectrometry positive for Pu uptake, etc.), then the sample is prepared for analysis by TIMS. Part of the development process for establishing a program to determine Pu in bioassay samples by TIMS at the Savannah River Site involved a careful evaluation of the Pu blank value in the reagents used for sample preparation and in urine blanks. This exercise allowed for the evaluation of the newly developed radiochemical separation procedure, the resin bead loading procedure, and the detection limits of the thermal ionization mass spectrometer

  4. Identification of metabolites in urine and feces from rats dosed with the heterocyclic amine, 2-amino-3-methyl-9H-pyrido[2,3-b]indole (MeA alpha C)

    DEFF Research Database (Denmark)

    Frederiksen, H; Frandsen, H

    2004-01-01

    , the in vivo metabolism of MeA alpha C in rats was investigated. Rats were dosed with tritium-labeled MeA alpha C, and urine and feces were collected over 3 days. The metabolites of MeA alpha C were identified by high performance liquid chromatography-mass spectrometry and quantified by liquid scintillation...

  5. Methods of neutron spectrometry

    International Nuclear Information System (INIS)

    Doerschel, B.

    1981-01-01

    The different methods of neutron spectrometry are based on the direct measurement of neutron velocity or on the use of suitable energy-dependent interaction processes. In the latter case the measuring effect of a detector is connected with the searched neutron spectrum by an integral equation. The solution needs suitable unfolding procedures. The most important methods of neutron spectrometry are the time-of-flight method, the crystal spectrometry, the neutron spectrometry by use of elastic collisions with hydrogen nuclei, and neutron spectrometry with the aid of nuclear reactions, especially of the neutron-induced activation. The advantages and disadvantages of these methods are contrasted considering the resolution, the measurable energy range, the sensitivity, and the experimental and computational efforts. (author)

  6. Measurement of cross sections for alpha-induced reactions on 197Auand thick-target yields for the (alpha,gamma) process on 64Zn and63Cu

    Energy Technology Data Exchange (ETDEWEB)

    Basunia, M.S.; Shugart, H.A.; Smith, A.R.; Norman, E.B.

    2006-08-07

    We have measured the cross sections for the197Au(alpha,gamma)201Tl and 197Au(alpha,2n)199Tl reactions in the 17.9-to 23.9-MeV energy range, and 197Au(alpha,n)200Tl reaction in the 13.4-to 23.9-MeV energy range using an activation technique. Thick-targetyields for the 64Zn(alpha,gamma)68Ge (7- to 14-MeV) and63Cu(alpha,gamma)67Ga (7-MeV) reactions were measured. For allmeasurements, natural elements were bombarded with He+ beams from the88-inch Cyclotron at the Lawrence Berkeley National Laboratory (LBNL).Irradiated samples were counted using a gamma-spectrometry system at LBNLs Low Background Facility. Measured 197Au(alpha,gamma)201Tlcross-sections were compared with the NON-SMOKER theoretical values. Thethick-target yields for the 64Zn(alpha,gamma)68Ge and63Cu(alpha,gamma)67Ga reactions are also compared with the theoreticalyield, calculated numerically using the energy dependent NON-SMOKER crosssection data. In both cases, measured values are found to follow a trendof overlapping the predicted value near the alpha nucleus barrier heightand fall below with a slowly widening difference between them in the subbarrier energy points.

  7. Demystifying AlphaGo Zero as AlphaGo GAN

    OpenAIRE

    Dong, Xiao; Wu, Jiasong; Zhou, Ling

    2017-01-01

    The astonishing success of AlphaGo Zero\\cite{Silver_AlphaGo} invokes a worldwide discussion of the future of our human society with a mixed mood of hope, anxiousness, excitement and fear. We try to dymystify AlphaGo Zero by a qualitative analysis to indicate that AlphaGo Zero can be understood as a specially structured GAN system which is expected to possess an inherent good convergence property. Thus we deduct the success of AlphaGo Zero may not be a sign of a new generation of AI.

  8. $\\alpha$-Representation for QCD

    OpenAIRE

    Tuan, Richard Hong

    1998-01-01

    An $\\alpha$-parameter representation is derived for gauge field theories.It involves, relative to a scalar field theory, only constants and derivatives with respect to the $\\alpha$-parameters. Simple rules are given to obtain the $\\alpha$-representation for a Feynman graph with an arbitrary number of loops in gauge theories in the Feynman gauge.

  9. Alpha Theta Meditation: Phenomenological, neurophysiologic ...

    African Journals Online (AJOL)

    Alpha Theta Meditation: Phenomenological, neurophysiologic, mindfulness, mood, health and sport implications. ... the single alpha theta meditation was associated with elevated alpha and theta activity, as well as decrease in negative mood perceptions, especially with regard to anxiety, sadness and confusion scores.

  10. Alpha scintillation radon counting

    International Nuclear Information System (INIS)

    Lucas, H.F. Jr.

    1977-01-01

    Radon counting chambers which utilize the alpha-scintillation properties of silver activated zinc sulfide are simple to construct, have a high efficiency, and, with proper design, may be relatively insensitive to variations in the pressure or purity of the counter filling. Chambers which were constructed from glass, metal, or plastic in a wide variety of shapes and sizes were evaluated for the accuracy and the precision of the radon counting. The principles affecting the alpha-scintillation radon counting chamber design and an analytic system suitable for a large scale study of the 222 Rn and 226 Ra content of either air or other environmental samples are described. Particular note is taken of those factors which affect the accuracy and the precision of the method for monitoring radioactivity around uranium mines

  11. Combining Alphas via Bounded Regression

    Directory of Open Access Journals (Sweden)

    Zura Kakushadze

    2015-11-01

    Full Text Available We give an explicit algorithm and source code for combining alpha streams via bounded regression. In practical applications, typically, there is insufficient history to compute a sample covariance matrix (SCM for a large number of alphas. To compute alpha allocation weights, one then resorts to (weighted regression over SCM principal components. Regression often produces alpha weights with insufficient diversification and/or skewed distribution against, e.g., turnover. This can be rectified by imposing bounds on alpha weights within the regression procedure. Bounded regression can also be applied to stock and other asset portfolio construction. We discuss illustrative examples.

  12. Atomic mass spectrometry

    International Nuclear Information System (INIS)

    Sanz-Medel, A.

    1997-01-01

    The elemental inorganic analysis seems to be dominated today by techniques based on atomic spectrometry. After an evaluation of advantages and limitations of using mass analysers (ion detectors) versus conventional photomultipliers (photon detector) a brief review of the more popular techniques of the emerging Atomic Mass spectrometry is carried out. Their huge potential for inorganic trace analysis is such that in the future we could well witness how this end of the century and millennium marked the fall of the photons empire in Analytical Atomic Spectrometry. (Author)

  13. Alpha-bungarotoxin binding to target cell in a developing visual system by carboxylated nanodiamond

    Energy Technology Data Exchange (ETDEWEB)

    Liu, K-K; Chen, P-Y; Lee, Tony J F; Chao, J-I [Institute of Pharmacology and Toxicology, Tzu Chi University, Hualien 970, Taiwan (China); Chen, M-F [Neuro-Medical Scientific Center, Tzu Chi General Hospital, Hualien 970, Taiwan (China); Cheng, C-L [Department of Physics, National Dong Hwa University, Hualien 974, Taiwan (China); Chang, C-C [Department of Biological Science and Technology, National Chiao Tung University, Hsin-Chu 300, Taiwan (China); Ho, Y-P [Department of Chemistry, National Dong Hwa University, Hualien 974, Taiwan (China)], E-mail: chaoji@mail.tcu.edu.tw

    2008-05-21

    Biological molecules conjugating with nanoparticles are valuable for applications including bio-imaging, bio-detection, and bio-sensing. Nanometer-sized diamond particles have excellent electronic and chemical properties for bio-conjugation. In this study, we manipulated the carboxyl group produced on the surface of nanodiamond (carboxylated nanodiamond, cND) for conjugating with alpha-bungarotoxin ({alpha}-BTX), a neurotoxin derived from Bungarus multicinctus with specific blockade of alpha7-nicotinic acetylcholine receptor ({alpha}7-nAChR). The electrostatic binding of cND-{alpha}-BTX was mediated by the negative charge of the cND and the positive charge of the {alpha}-BTX in physiological pH conditions. Sodium dodecyl sulfate-polyacrylamide gel analysis and matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI/TOF-MS) spectra displayed that {alpha}-BTX proteins were conjugated with cND particles via non-covalent bindings. The green fluorescence of the cND particles combining with the red fluorescence of tetramethylrhodamine-labeled {alpha}-BTX presented a yellow color at the same location, which indicated that {alpha}-BTX proteins were conjugated with cND particles. Xenopus laevis's oocytes expressed the human {alpha}7-nAChR proteins by microinjection with {alpha}7-nAChR mRNA. The cND-{alpha}-BTX complexes were bound to {alpha}7-nAChR locating on the cell membrane of oocytes and human lung A549 cancer cells analyzed by laser scanning confocal microscopy. The choline-evoked {alpha}7-nAChR-mediated inward currents of the oocytes were blocked by cND-{alpha}-BTX complexes in a concentration-dependent manner using two-electrode voltage-clamp recording. Furthermore, the fluorescence intensity of cND-{alpha}-BTX binding on A549 cells could be quantified by flow cytometry. These results indicate that cND-conjugated {alpha}-BTX still preserves its biological activity in blocking the function of {alpha}7-nAChR, and provide a visual

  14. Molecular Imaging Mass Spectrometry

    Directory of Open Access Journals (Sweden)

    Kovac, S.

    2009-05-01

    Full Text Available Molecular imaging mass spectrometry (IMS is a recently developed method for direct determination of spatial distribution of biopolymers, preferably proteins on cell surface and tissues. Imaging mass spectrometry data are mainly based on Matrix-Assisted Laser Desorption/Ionization- Time of Flight (MALDI TOF. The MALDI TOF based imaging mass spectrometry was applied for determination of changes in kidney tissue of sensitive mice after poisoning with aristolochic acid I. The second application presented here were changes in the gastric tissue in mice after infection with Helicobacter pylori, as a model of gastric cancer in humans caused by this pathogen microorganism. Molecular imaging mass spectrometry can be applied in medicine, mostly for identification of candidate biomarkers for malignant and non-malignant diseases. Furthermore, imaging MS has almost unlimited capacity in agriculture, food technology and biotechnology, e. g. for monitoring, process development and quality control of manufactured tissue of animal, plant and microbial origin.

  15. Software for nuclear spectrometry

    International Nuclear Information System (INIS)

    1998-10-01

    The Advisory Group Meeting (AGM) on Software for Nuclear Spectrometry was dedicated to review the present status of software for nuclear spectrometry and to advise on future activities in this field. Because similar AGM and consultant's meetings had been held in the past; together with an attempt to get more streamlined, this AGM was devoted to the specific field of software for gamma ray spectrometry. Nevertheless, many of the issues discussed and the recommendations made are of general concern for any software on nuclear spectrometry. The report is organized by sections. The 'Summary' gives conclusions and recommendations adopted at the AGM. These conclusions and recommendations resulted from the discussions held during and after presentations of the scientific and technical papers. These papers are reported here in their integral form in the following Sections

  16. Ion mobility spectrometry

    CERN Document Server

    Eiceman, GA

    2005-01-01

    Key Developments for Faster, More Precise Detection Capabilities Driven by the demand for the rapid and advanced detection of explosives, chemical and biological warfare agents, and narcotics, ion mobility spectrometry (IMS) undergone significant refinements in technology, computational capabilities, and understanding of the principles of gas phase ion chemistry and mobility. Beginning with a thorough discussion of the fundamental theories and physics of ion mobility, Ion Mobility Spectrometry, Second Edition describes the recent advances in instrumentation and newly

  17. Identification of a novel bean alpha-amylase inhibitor with chitinolytic activity.

    Science.gov (United States)

    Dayler, Charles S A; Mendes, Paulo A M; Prates, Maura V; Bloch, Carlos; Franco, Octavio L; Grossi-de-Sá, Maria F

    2005-10-24

    Zabrotes subfasciatus is a devastating starch-dependent storage bean pest. In this study, we attempted to identify novel alpha-amylase inhibitors from wild bean seeds, with efficiency toward pest alpha-amylases. An inhibitor named Phaseolus vulgaris chitinolytic alpha-amylase inhibitor (PvCAI) was purified and mass spectrometry analyses showed a protein with 33330 Da with the ability to form dimers. Purified PvCAI showed significant inhibitory activity against larval Z. subfasciatus alpha-amylases with no activity against mammalian enzymes. N-terminal sequence analyses showed an unexpected high identity to plant chitinases from the glycoside hydrolase family 18. Furthermore, their chitinolytic activity was also detected. Our data provides compelling evidence that PvCAI also possessed chitinolytic activity, indicating the emergence of a novel alpha-amylase inhibitor class.

  18. Treatment of alpha bearing wastes

    International Nuclear Information System (INIS)

    1988-01-01

    This report deals with the current state of the art of alpha waste treatment, which is an integral part of the overall nuclear waste management system. The International Atomic Energy Agency (IAEA) defines alpha bearing waste as 'waste containing one or more alpha emitting radionuclides, usually actinides, in quantities above acceptable limits'. The limits are established by national regulatory bodies. The limits above which wastes are considered as alpha contaminated refer to the concentrations of alpha emitters that need special consideration for occupational exposures and/or potential safety, health, or environmental impact during one or more steps from generation through disposal. Owing to the widespread use of waste segregation by source - that is, based upon the 'suspect origin' of the material - significant volumes of waste are being handled as alpha contaminated which, in fact, do not require such consideration by reason of risk or environmental concern. The quantification of de minimis concepts by national regulatory bodies could largely contribute to the safe reduction of waste volumes and associated costs. Other factors which could significantly contribute to the reduction of alpha waste arisings are an increased application of assaying and sorting, instrumentation and the use of feedback mechanisms to control or modify the processes which generate these wastes. Alpha bearing wastes are generated during fabrication and reprocessing of nuclear fuels, decommissioning of alpha contaminated facilities, and other activities. Most alpha wastes are contact handled, but a small portion may require shielding or remote handling because of high levels of neutron (n), beta (β), or gamma (γ) emissions associated with the waste material. This report describes the sources and characteristics of alpha wastes and strategies for alpha waste management. General descriptions of treatment processes for solid and liquid alpha wastes are included. 71 refs, 14 figs, 9 tabs

  19. The alpha effect

    International Nuclear Information System (INIS)

    Anon.

    1982-01-01

    Much of the recent interest in RAM system reliability stems from concern over alpha particle soft error rates reported for the initial 64 k RAMs. With increasing memory density likely in the next few years the problem of soft errors is rearing its head again. A few years ago ITT carried out experiments on 16k RAMs and found no significant problems. However, recent tests have shown a raise in the number of soft errors with 64k RAMs, and the launch of 256k and 512k memories is likely to make the problem acute

  20. Alpha-mannosidosis

    Directory of Open Access Journals (Sweden)

    Nilssen Øivind

    2008-07-01

    Full Text Available Abstract Alpha-mannosidosis is an inherited lysosomal storage disorder characterized by immune deficiency, facial and skeletal abnormalities, hearing impairment, and intellectual disability. It occurs in approximately 1 of 500,000 live births. The children are often born apparently normal, and their condition worsens progressively. Some children are born with ankle equinus or develop hydrocephalus in the first year of life. Main features are immune deficiency (manifested by recurrent infections, especially in the first decade of life, skeletal abnormalities (mild-to-moderate dysostosis multiplex, scoliosis and deformation of the sternum, hearing impairment (moderate-to-severe sensorineural hearing loss, gradual impairment of mental functions and speech, and often, periods of psychosis. Associated motor function disturbances include muscular weakness, joint abnormalities and ataxia. The facial trait include large head with prominent forehead, rounded eyebrows, flattened nasal bridge, macroglossia, widely spaced teeth, and prognathism. Slight strabismus is common. The clinical variability is significant, representing a continuum in severity. The disorder is caused by lysosomal alpha-mannosidase deficiency. Alpha-mannosidosis is inherited in an autosomal recessive fashion and is caused by mutations in the MAN2B1 gene located on chromosome 19 (19 p13.2-q12. Diagnosis is made by measuring acid alpha-mannosidase activity in leukocytes or other nucleated cells and can be confirmed by genetic testing. Elevated urinary secretion of mannose-rich oligosaccharides is suggestive, but not diagnostic. Differential diagnoses are mainly the other lysosomal storage diseases like the mucopolysaccharidoses. Genetic counseling should be given to explain the nature of the disease and to detect carriers. Antenatal diagnosis is possible, based on both biochemical and genetic methods. The management should be pro-active, preventing complications and treating

  1. Assessment of measurement result uncertainty in determination of 210Pb with the focus on matrix composition effect in gamma-ray spectrometry

    International Nuclear Information System (INIS)

    Iurian, A.R.; Pitois, A.; Kis-Benedek, G.; Migliori, A.; Padilla-Alvarez, R.; Ceccatelli, A.

    2016-01-01

    Reference materials were used to assess measurement result uncertainty in determination of 210 Pb by gamma-ray spectrometry, liquid scintillation counting, or indirectly by alpha-particle spectrometry, using its daughter 210 Po in radioactive equilibrium. Combined standard uncertainties of 210 Pb massic activities obtained by liquid scintillation counting are in the range 2–12%, depending on matrices and massic activity values. They are in the range 1–3% for the measurement of its daughter 210 Po using alpha-particle spectrometry. Three approaches (direct computation of counting efficiency and efficiency transfer approaches based on the computation and, respectively, experimental determination of the efficiency transfer factors) were applied for the evaluation of 210 Pb using gamma-ray spectrometry. Combined standard uncertainties of gamma-ray spectrometry results were found in the range 2–17%. The effect of matrix composition on self-attenuation was investigated and a detailed assessment of uncertainty components was performed. - Highlights: • Confirmed 210 Pb certified values by LSC and alpha-particle spectrometry ( 210 Po). • Assessed 210 Po measurement result uncertainty by alpha-particle spectrometry. • Matrix composition effect on gamma-ray spectrometry measurement result uncertainty. • Assessment of 210 Pb measurement result uncertainty by gamma-ray spectrometry. • Comparison of techniques and approaches: ‘fit-for-purpose’ considerations.

  2. alpha-particle radioactivity from LR 115 by two methods of analysis

    CERN Document Server

    Azkour, K; Adloff, J C; Pape, A

    1999-01-01

    LR115 track detectors were exposed to samples of Moroccan phosphate and phosphogypsum to measure their alpha-particle radioactivity. Then two formalisms were used for the dosimetry: simulation by a Monte Carlo method and determination of concentrations from a numerically integrated track registration equation. The results were compared with those deduced gamma-ray spectrometry.

  3. Alpha activity measurement with lsc

    International Nuclear Information System (INIS)

    Dobrin, R. I.; Dulama, C. N.; Ciocirlan, C. N.; Toma, A.; Stoica, S. M.; Valeca, M.

    2013-01-01

    Recently, we showed that the alpha activity in liquid samples can be measured using a liquid scintillation analyzer without alpha/beta discrimination capability. The purpose of this work was to evaluate the performances of the method and to optimize the procedure of the sample preparation. A series of tests was performed to validate the procedure of alpha emitting radionuclides extraction in aqueous samples with Actinide Resin, especially regarding to the contact time required to extract all alpha nuclides. The main conclusions were that a minimum 18 hours stirring time is needed to achieve a percent recovery of the alpha nuclides grater than 90% and that the counting efficiency of alphas measurements with LSC is nearly 100%. (authors)

  4. Molecular characterization of alpha 1- and alpha 2-adrenoceptors.

    Science.gov (United States)

    Harrison, J K; Pearson, W R; Lynch, K R

    1991-02-01

    Three 'alpha 1-adrenoceptors' and three 'alpha 2-adrenoceptors' have now been cloned. How closely do these receptors match the native receptors that have been identified pharmacologically? What are the properties of these receptors, and how do they relate to other members of the cationic amine receptor family? Kevin Lynch and his colleagues discuss these questions in this review.

  5. Alpha wastes treatment

    International Nuclear Information System (INIS)

    Thouvenot, P.

    2000-01-01

    Alter 2004, the alpha wastes issued from the Commissariat a l'Energie Atomique installations will be sent to the CEDRA plant. The aims of this installation are decontamination and wastes storage. Because of recent environmental regulations concerning ozone layer depletion, the use of CFC 113 in the decontamination unit, as previously planned, is impossible. Two alternatives processes are studied: the AVD process and an aqueous process including surfactants. Best formulations for both processes are defined issuing degreasing kinetics. It is observed that a good degreasing efficiency is linked to a good decontamination efficiency. Best results are obtained with the aqueous process. Furthermore, from the point of view of an existing waste treatment unit, the aqueous process turns out to be more suitable than the AVD process. (author)

  6. Ion Mobility Spectrometry (IMS) and Mass Spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Shvartsburg, Alexandre A.

    2010-04-20

    In a media of finite viscosity, the Coulomb force of external electric field moves ions with some terminal speed. This dynamics is controlled by “mobility” - a property of the interaction potential between ions and media molecules. This fact has been used to separate and characterize gas-phase ions in various modes of ion mobility spectrometry (IMS) developed since 1970. Commercial IMS devices were introduced in 1980-s for field detection of volatile traces such as explosives and chemical warfare agents. Coupling to soft-ionization sources, mass spectrometry (MS), and chromatographic methods in 1990-s had allowed IMS to handle complex samples, enabling new applications in biological and environmental analyses, nanoscience, and other areas. Since 2003, the introduction of commercial systems by major instrument vendors started bringing the IMS/MS capability to broad user community. The other major development of last decade has been the differential IMS or “field asymmetric waveform IMS” (FAIMS) that employs asymmetric time-dependent electric field to sort ions not by mobility itself, but by the difference between its values in strong and weak electric fields. Coupling of FAIMS to conventional IMS and stacking of conventional IMS stages have enabled two-dimensional separations that dramatically expand the power of ion mobility methods.

  7. New and effective multi-element alpha-hematite systems for reduction of trichloroethylene.

    Science.gov (United States)

    Ghorpade, Praveen A; Kim, Jung-Hwan; Choi, Won-Ho; Park, Joo-Yang

    2014-01-01

    The reactivity of different alpha-hematite (alpha-Fe203) systems for dechlorination of trichloroethylene (TCE) in the presence of Fe(II) and CaO was investigated. Initially different experiments were conducted to investigate the reactivity of pure and doped alpha-Fe203. It was found that the presence of elements such as Si, Cu, and Mn in alpha-Fe203 had a significant effect on TCE reduction potential of alpha-Fe203; however, the reduction potential was less than that of alpha-Fe203 (Bayferrox- 110 M, used in a previous study). Further studies were carried out and alpha-Fe203 was synthesized in a manner similar to that of Bayferrox-110 M. This synthetic alpha-Fe203 showed improved reactivity and was found to follow pseudo-first-order kinetics when used in TCE reduction experiments. The preliminary end products analysis showed that TCE degradation was probably via beta-elimination pathway. Detailed investigations ofa-Fe203 systems were carried out using X-ray diffraction, X-ray fluorescence, and scanning electron microscopy with energy-dispersive spectrometry. The results demonstrated that the TCE reduction capacity of alpha-Fe203 was strongly dependent on the other elements present in iron powder used to synthesize alpha-Fe203. It was suspected that these multi-elements in alpha-Fe203 helped to improve its conduction property. Current findings suggest that alpha-Fe203 not in the pure but combined with other elements could be thought as a potential system for TCE reduction.

  8. Mind Your p's and Alphas.

    Science.gov (United States)

    Stallings, William M.

    In the educational research literature alpha, the a priori level of significance, and p, the a posteriori probability of obtaining a test statistic of at least a certain value when the null hypothesis is true, are often confused. Explanations for this confusion are offered. Paradoxically, alpha retains a prominent place in textbook discussions of…

  9. Summary of Alpha Particle Transport

    Energy Technology Data Exchange (ETDEWEB)

    Medley, S.S.; White, R.B.; Zweben, S.J.

    1998-08-19

    This paper summarizes the talks on alpha particle transport which were presented at the 5th International Atomic Energy Agency's Technical Committee Meeting on "Alpha Particles in Fusion Research" held at the Joint European Torus, England in September 1997.

  10. Overexpression, purification, and characterization of recombinant barley alpha-amylases 1 and 2 secreted by the methylotrophic yeast Pichia pastoris

    DEFF Research Database (Denmark)

    Juge, N; Andersen, Jens S.; Tull, D

    1996-01-01

    Recombinant barley alpha-amylase isozymes 1 and 2 were secreted by Pichia pastoris at up to 50 and 1 mg/liter, respectively, representing approximately a 50-fold increase compared to the levels of the heterologous expression by Saccharomyces cerevisiae. The cDNA clones E or pM/C encoding isozymes 1...... with a value of 45,447 calculated from the sequence, liquid chromatography/mass spectrometry of endo Lys C-generated peptides followed by tandem mass spectrometry on a nanoelectrospray ionization/mass spectrometry/mass spectrometry system identified additional recombinant isozyme 1 forms to be glycosylated...... on Thr410, N-acetylated on His1, S-glutathionylated on Cys95, or C-terminally truncated of -412RS, -411QRS, and -410LQRS. The recombinant enzymes and the alpha-amylases from barley malt closely resembled each other in enzymatic activity on insoluble Blue Starch, amylose of degree of polymerization 17...

  11. Proteinaceous alpha-araylase inhibitors

    DEFF Research Database (Denmark)

    Svensson, Birte; Fukuda, Kenji; Nielsen, P.K.

    2004-01-01

    Proteins that inhibit alpha-amylases have been isolated from plants and microorganisms. These inhibitors can have natural roles in the control of endogenous a-amylase activity or in defence against pathogens and pests; certain inhibitors are reported to be antinutritional factors. The alpha-amylase...... inhibitors belong to seven different protein structural families, most of which also contain evolutionary related proteins without inhibitory activity. Two families include bifunctional inhibitors acting both on alpha-amylases and proteases. High-resolution structures are available of target alpha-amylases...... in complex with inhibitors from five families. These structures indicate major diversity but also some similarity in the structural basis of alpha-amylase inhibition. Mutational analysis of the mechanism of inhibition was performed in a few cases and various protein engineering and biotechnological...

  12. Stable isotope studies on steroid metabolism and kinetics: Sulfates of 3 alpha-hydroxy-5 alpha-pregnane derivatives in human pregnancy

    International Nuclear Information System (INIS)

    Anderson, R.A.; Baillie, T.A.; Axelson, M.; Cronholm, T.; Sjoevall, K.S.; Sjoevall, J.

    1990-01-01

    The metabolism and production rates of 3 alpha-hydroxy-5 alpha-pregnan-20-one sulfate and the 3-sulfate and 3,20-disulfate of 5 alpha-pregnane-3 alpha,20 alpha-diol in pregnant women were studied. The steroid sulfates were labeled with deuterium in the 3 beta,11,11- or 3 beta,11,11,20 beta-positions and were injected intravenously. The deuterium content of steroids in the monosulfate and disulfate fraction of plasma collected at different times after the injection was determined by capillary column gas chromatography/mass spectrometry. The injected steroid sulfates underwent oxidoreduction at C-20 and 16 alpha-hydroxylation. In addition, the 3-sulfate of 5 alpha-pregnane-3 alpha,20 alpha-diol became hydroxylated at C-21. The pregnanediol and pregnanetriol monosulfates were also converted to disulfates. No evidence was obtained for a metabolic sequence involving hydrolysis, oxidoreduction, and resulfation at the C-3 position. Production rates and rates of metabolic transformations were determined using different one- and two-pool models. The production rate of the pregnanolone/pregnanediol monosulfate couple was 0.08 to 0.5 mmol/24 h, the variability probably depending both on individual factors and stage of pregnancy. The half-life time for oxidation and reduction at C-20 was 0.1 to 0.4 hours, reduction being the faster process. The half-life time for the turnover of the steroid skeleton was 1.3 to 3.3 hours. The injected steroid monosulfates were 16 alpha-hydroxylated at a rate of 1 to 8 mumol/24 h. A significant fraction of these 16 alpha-hydroxylated steroid sulfates, 0.5 to 25 mumol/24 h, was formed from other, probably unconjugated, precursors. The 16 alpha-hydroxylated steroid monosulfates underwent rapid oxidoreduction at C-20. The 3-sulfate of 5 alpha-pregnane-3 alpha,20 alpha-diol was hydroxylated at C-21

  13. Sensitive bioassay for detection of PPAR{alpha} potentially hazardous ligands with gold nanoparticle probe

    Energy Technology Data Exchange (ETDEWEB)

    Xia, Wei; Wan, Yan-Jian [Minister of Education Key Laboratory of Environment and Health, School of Public Health, Tongji Medical College of Huazhong University of Science and Technology, Wuhan, Hubei Province 430030 (China); Wang, Xianliang [Division of Environmental Pollution and Human Health, Chinese Research Academy of Environmental Sciences, Beijing 100012 (China); Li, Yuan-yuan; Yang, Wen-Jie; Wang, Chun-Xiang [Minister of Education Key Laboratory of Environment and Health, School of Public Health, Tongji Medical College of Huazhong University of Science and Technology, Wuhan, Hubei Province 430030 (China); Xu, Shun-qing, E-mail: shunqing@mails.tjmu.edu.cn [Minister of Education Key Laboratory of Environment and Health, School of Public Health, Tongji Medical College of Huazhong University of Science and Technology, Wuhan, Hubei Province 430030 (China)

    2011-09-15

    Highlights: {yields} We develop a sensitive and high throughput method to screen PPAR{alpha} ligands. {yields} This method is based on the ligand-receptor interaction on microplate. {yields} The sensitivity is increased through sliver enhancement on captured gold nanoparticle probes. {yields} There is a significant correlation between the bioassay and LC-MS for water spiked samples. - Abstract: There are so many kinds of peroxisome proliferator-activated receptor {alpha} (PPAR{alpha}) ligands with hazardous effect for human health in the environment, such as certain herbicides, plasticizers and drugs. Among these agonists, perfluorooctane sulfonate (PFOS), perfluorooctanoic acid (PFOA), and mono-(2-ethylhexyl) phthalate (MEHP) are mostly investigated due to their persistence and accumulation in environment and their potential toxicity via PPAR{alpha}. This investigation aims at developing a bioassay method to detect PPAR{alpha} ligands based on the ligand-receptor interaction on microplate. PPAR{alpha}, which formed heterodimers with retinoid X receptor-{alpha} (RXR{alpha}), were activated by PPAR{alpha} ligands to form ligands-PPAR{alpha}-RXR{alpha} complexes. Then the complexes were transferred into a microplate and captured via monoclonal anti-PPAR{alpha} antibody. The PPAR{alpha} responsive elements (PPRE) modified-gold nanoparticle probes were captured by the ligand-PPAR{alpha}-RXR{alpha} complexes immobilized on the microplate, and then could be quantified through measuring the optical density after silver enhancement. The results showed that PFOS was quantified with a linear range from 100 pM to 1 {mu}M and the detection limit was 10 pM. In addition to PFOS, PFOA and MEHP were also quantified within a proper range through the proposed bioassay. This bioassay was compared with that of liquid chromatography tandem-mass spectrometry (LC-MS) for water spiked samples with a significant correlation (r = 0.9893). This study provides a high-throughput detection

  14. Fourier Transform Mass Spectrometry.

    Science.gov (United States)

    Gross, Michael L.; Rempel, Don L.

    1984-01-01

    Discusses the nature of Fourier transform mass spectrometry and its unique combination of high mass resolution, high upper mass limit, and multichannel advantage. Examines its operation, capabilities and limitations, applications (ion storage, ion manipulation, ion chemistry), and future applications and developments. (JN)

  15. Miniaturization and Mass Spectrometry

    NARCIS (Netherlands)

    le Gac, S.; le Gac, Severine; van den Berg, Albert; van den Berg, A.; Unknown, [Unknown

    2009-01-01

    With this book we want to illustrate how two quickly growing fields of instrumentation and technology, both applied to life sciences, mass spectrometry and microfluidics (or microfabrication) naturally came to meet at the end of the last century and how this marriage impacts on several types of

  16. Targeted mass spectrometry

    DEFF Research Database (Denmark)

    Osinalde, Nerea; Aloria, Kerman; Omaetxebarria, Miren J.

    2017-01-01

    biological processes in the cell and it is one the most characterized PTM up to date. During the last decade, the development of phosphoprotein/phosphopeptide enrichment strategies and mass spectrometry (MS) technology has revolutionized the field of phosphoproteomics discovering thousands of new site...

  17. ALPHA freezes antiprotons

    CERN Multimedia

    CERN Bulletin

    2010-01-01

    Laboratories like CERN can routinely produce many different types of antiparticles. In 1995, the PS210 experiment formed the first antihydrogen atoms and a few years later, in 2002, ATRAP and ATHENA were already able to produce several thousand of them. However, no experiment in the world has succeeded in ‘trapping’ these anti-atoms in order to study them. This is the goal of the ALPHA experiment, which has recently managed to cool down the antiprotons to just a few Kelvin. This represents a major step towards trapping the anti-atom, thus opening a new avenue into the investigation of antimatter properties.   Members of the ALPHA collaboration working on the apparatus in the Antiproton Decelerator experimental hall at CERN. Just like the atom, the anti-atom is neutral. Unlike the atom, the anti-atom is made up of antiprotons (as opposed to protons in the atom) and positrons (as opposed to electrons). In order to thoroughly study the properties of the anti-atoms, scien...

  18. Alpha-1-antitrypsin deficiency.

    Science.gov (United States)

    Bals, Robert

    2010-10-01

    Alpha-1-antitrypsin deficiency (AATD) is a rare genetic disorder associated with the development of liver and lung disease. AAT is a 52-kD glycoprotein, produced mainly by hepatocytes and secreted into the blood. Agglomeration of the AAT-protein in hepatocytes can result in liver disease. Exposure to smoke is the major risk factor for the development of lung disease characterised as early chronic obstructive lung disease (COPD). Diagnosis is based on the analysis of the AAT genotype and phenotype. The measurement of the AAT serum level is useful as screening test. Liver biopsy is not necessary to establish the diagnosis. Therapy for AAT-related liver disease is supportive, a specific therapy is not available. AATD is a rare condition (1:5000-10000) and, as a consequence, data and information on diagnosis and treatment are not easily accessible. This chapter provides a comprehensive overview on AATD, covering basic biology, diagnostic and therapeutic approaches. Copyright © 2010 Elsevier Ltd. All rights reserved.

  19. Comparison of mass-spectrometry and α-counting in analysis of uranium and plutonium isotopes in environmental samples

    International Nuclear Information System (INIS)

    Irleweck, K.; Pichlmayer, F.

    1980-01-01

    The determination of trace amounts of U and Pu isotopes is of interest in environmental and personal monitoring programmes. Commonly after preconcentration and separation of the radionuclides a proper sample is prepared electrolytically and the measurements are performed by alpha spectrometry. Some investigations on uranium isotopic abundances and on plutonium fallout deposition in soil have been carried out in this way. It is impossible to distinguish between the isotopes 239 Pu and 240 Pu by alpha spectrometry, however, because their α-energies are too close together. Such determinations can only be carried out by mass spectrometry. Specific Pu emissions, e.g. from nuclear production plants, can be discriminated from the global fallout level. Mass spectrometry is the more sensitive method for measuring long-lived nuclides compared with α-spectrometry. In the case of soil analysis, however, Pu detection is obstructed by the high natural uranium content, usually in the range 0.2 to 2.0 ppm which exceeds the trace amounts of plutonium by several orders of magnitude. This work describes a chemical procedure which separates U/Pu sufficiently for alpha spectrometry as well as for mass spectrometry, and compares results of environmental analysis applying both methods. (author)

  20. Cyclodextrin--piroxicam inclusion complexes: analyses by mass spectrometry and molecular modelling

    Science.gov (United States)

    Gallagher, Richard T.; Ball, Christopher P.; Gatehouse, Deborah R.; Gates, Paul J.; Lobell, Mario; Derrick, Peter J.

    1997-11-01

    Mass spectrometry has been used to investigate the natures of non-covalent complexes formed between the anti-inflammatory drug piroxicam and [alpha]-, [beta]- and [gamma]-cyclodextrins. Energies of these complexes have been calculated by means of molecular modelling. There is a correlation between peak intensities in the mass spectra and the calculated energies.

  1. Measurement of $\\alpha_{s}$ with Radiative Hadronic Events

    CERN Document Server

    Abbiendi, G; Åkesson, P F; Alexander, G; Anagnostou, G; Anderson, K J; Asai, S; Axen, D; Bailey, I; Barberio, E; Barillari, T; Barlow, R J; Batley, R J; Bechtle, P; Behnke, T; Bell, K W; Bell, P J; Bella, G; Bellerive, A; Benelli, G; Bethke, S; Biebel, O; Boeriu, O; Bock, P; Boutemeur, M; Braibant, S; Brown, R M; Burckhart, H J; Campana, S; Capiluppi, P; Carnegie, R K; Carter, A A; Carter, J R; Chang, C Y; Charlton, D G; Ciocca, C; Csilling, A; Cuffiani, M; Dado, S; Dallavalle, M; de Roeck, A; De Wolf, E A; Desch, K; Dienes, B; Dubbert, J; Duchovni, E; Duckeck, G; Duerdoth, I P; Etzion, E; Fabbri, F; Ferrari, P; Fiedler, F; Fleck, I; Ford, M; Frey, A; Gagnon, P; Gary, J W; Geich-Gimbel, C; Giacomelli, G; Giacomelli, P; Giunta, M; Goldberg, J; Gross, E; Grunhaus, J; Gruwé, M; Sen-Gupta, A; Hajdu, C; Hamann, M; Hanson, G G; Harel, A; Hauschild, M; Hawkes, C M; Hawkings, R; Herten, G; Heuer, R D; Hill, J C; Horváth, D; Igo-Kemenes, P; Ishii, K; Jeremie, H; Jovanovic, P; Junk, T R; Kanzaki, J; Karlen, D; Kawagoe, K; Kawamoto, T; Keeler, R K; Kellogg, R G; Kennedy, B W; Kluth, S; Kobayashi, T; Kobel, M; Komamiya, S; Kramer, T; Krasznahorkays, A Jr; Krieger, P; Von Krogh, J; Kühl, T; Kupper, M; Lafferty, G D; Landsman, H; Lanske, D; Lellouch, D; Letts, J; Levinson, L; Lillich, J; Lloyd, S L; Loebinger, F K; Lü, J; Ludwig, A; Ludwig, J; Mader, W; Marcellini, S; Martin, A J; Mashimo, T; Mättig, P; McKenna, J; McPherson, R A; Meijers, F; Menges, W; Merritt, F S; Mes, H; Meyer, N; Michelini, A; Mihara, S; Mikenberg, G; Miller, D J; Mohr, W; Mori, T; Mutter, A; Nagai, K; Nakamura, I; Nanjo, H; Neal, H A; O'Neale, S W; Oh, A; Oreglia, M J; Orito, S; Pahl, C; Pásztor, G; Pater, J R; Pilcher, J E; Pinfold, J L; Plane, D E; Pooth, O; Przybycien, M; Quadt, A; Rabbertz, K; Rembser, C; Renkel, P; Roney, J M; Rossi, A M; Rozen, Y; Runge, K; Sachs, K; Saeki, T; Sarkisyan-Grinbaum, E; Schaile, A D; Schaile, O; Scharff-Hansen, P; Schiecks, J; Schörner-Sadenius, T; Schröder, M; Schumacher, M; Seuster, R; Shears, T G; Shen, B C; Sherwood, P; Skuja, A; Smith, A M; Sobie, R J; Söldner-Rembold, S; Spanó, F; Stahl, A; Strom, D; Ströhmer, R; Tarem, S; Tasevsky, M; Teuscher, R; Thomson, M A; Torrence, E; Toya, D; Trigger, I; Trócsányi, Z L; Tsur, E; Turner-Watson, M F; Ueda, I; Ujvári, B; Vollmer, C F; Vannerem, P; Vertesi, R; Verzocchi, M; Voss, H; Vossebeld, J; Ward, C P; Ward, D R; Watkins, P M; Watson, A T; Watson, N K; Wells, P S; Wengler, T; Wermes, N; Wilson, G W; Wilson, J A; Wolf, G; Wyatt, T R; Yamashita, S; Zer-Zion, D; Zivkovic, L

    2008-01-01

    Hadronic final states with a hard isolated photon are studied using data taken at centre-of-mass energies around the mass of the Z0 boson with the OPAL detector at LEP. The strong coupling alpha S is extracted by comparing data and QCD predictions for event shape observables at average reduced centre-of-mass energies ranging from 24 GeV to 78 GeV, and the energy dependence of alpha S is studied. Our results are consistent with the running of alpha S as predicted by QCD and show that within the uncertainties of our analysis event shapes in hadronic Z0 decays with hard and isolated photon radiation can be described by QCD at reduced centre-of-mass energies. Combining all values from different event shape observables and energies gives alpha S (Mz)=0.1182 pm 0.0015(stat.) pm 0.0101(syst.).

  2. What Powers Lyman alpha Blobs?

    OpenAIRE

    Ao, Y.; Matsuda, Y.; Beelen, A.; Henkel, C.; Cen, R.; De Breuck, C.; Francis, P.; Kovacs, A.; Lagache, G.; Lehnert, M.; Mao, M.; Menten, K. M.; Norris, R.; Omont, A.; Tatemastu, K.

    2015-01-01

    Lyman alpha blobs (LABs) are spatially extended lyman alpha nebulae seen at high redshift. The origin of Lyman alpha emission in the LABs is still unclear and under debate. To study their heating mechanism(s), we present Australia Telescope Compact Array (ATCA) observations of the 20 cm radio emission and Herschel PACS and SPIRE measurements of the far-infrared (FIR) emission towards the four LABs in the protocluster J2143-4423 at z=2.38. Among the four LABs, B6 and B7 are detected in the rad...

  3. Alpha heating in toroidal devices

    Energy Technology Data Exchange (ETDEWEB)

    Miley, G.H.

    1978-01-01

    Ignition (or near-ignition) by alpha heating is a key objective for the achievement of economic fusion reactors. While good confinement of high-energy alphas appears possible in larger reactors, near-term tokamak-type ignition experiments as well as some concepts for small reactors (e.g., the Field-Reversed Mirror or FRM) potentially face marginal situations. Consequently, there is a strong motivation to develop methods to evaluate alpha losses and heating profiles in some detail. Such studies for a TFTR-size tokamak and for a small FRM are described here.

  4. alpha-Dicarbonyl compounds formed by nonenzymatic browning during the dry heating of caseinate and lactose.

    Science.gov (United States)

    Ge Pan, Geoffrey; Oliver, Christine M; Melton, Laurence D

    2006-09-06

    A method using high-performance liquid chromatography with UV and electrospray ionization mass spectrometry detection was developed for monitoring the alpha-dicarbonyl compound profiles generated from nonenzymatic browning using o-phenylenediamine (OPD) as a trapping agent. The alpha-dicarbonyl compounds were generated by the "dry" reaction of sodium caseinate and lactose heated at various relative humidities (RHs). The proportions of alpha-dicarbonyls formed were different for samples heated at low, intermediate, and high RHs. This study shows that relatively large amounts of 3-deoxypentosulose and galactosyl 2-pentosulose are produced under high RHs, while galactosyl hexosulose and 1,4-dideoxyhexosulose are elevated under low RH conditions. Both caramelization and Maillard reaction pathways contributed to the generation of alpha-dicarbonyls.

  5. Determination of 210Pb in marine sediment core- A comparison between alpha and gamma techniques

    International Nuclear Information System (INIS)

    Zal Uyun Wan Mahmood; Yii Mei Wo; Zaharudin Ahmad

    2010-01-01

    The most commonly used techniques of alpha and gamma spectrometry were performed to measure 210 Pb activity in marine sediment core as a comparison. Alpha analytical technique measured the activity of 210 Pb from its in-grow grand-daughter 210 Po after a chemical separation, assuming radioactive equilibrium between the two radionuclides. Meanwhile, gamma analysis technique allows direct measurement, non-destructive and no preliminary chemical separation. Through the comparison, it is found that both alpha and gamma analysis techniques were slightly difference. Overall, the results from alpha analytical technique were basically higher than those from the gamma analytical techniques. Some logical argument had been discussed to explain this situation. In routine analysis, the analytical technique used should be chosen carefully based on advantages and disadvantages of the each technique and analysis requirements. Therefore, it is recommended to determine exactly the needs and purpose of analysis and to know the sample history before decide the appropriate analytical technique. (author)

  6. Desorption in Mass Spectrometry.

    Science.gov (United States)

    Usmanov, Dilshadbek Tursunbayevich; Ninomiya, Satoshi; Chen, Lee Chuin; Saha, Subhrakanti; Mandal, Mridul Kanti; Sakai, Yuji; Takaishi, Rio; Habib, Ahsan; Hiraoka, Kenzo; Yoshimura, Kentaro; Takeda, Sen; Wada, Hiroshi; Nonami, Hiroshi

    2017-01-01

    In mass spectrometry, analytes must be released in the gas phase. There are two representative methods for the gasification of the condensed samples, i.e. , ablation and desorption. While ablation is based on the explosion induced by the energy accumulated in the condensed matrix, desorption is a single molecular process taking place on the surface. In this paper, desorption methods for mass spectrometry developed in our laboratory: flash heating/rapid cooling, Leidenfrost phenomenon-assisted thermal desorption (LPTD), solid/solid friction, liquid/solid friction, electrospray droplet impact (EDI) ionization/desorption, and probe electrospray ionization (PESI), will be described. All the methods are concerned with the surface and interface phenomena. The concept of how to desorb less-volatility compounds from the surface will be discussed.

  7. Rutherford Backscattering Spectrometry

    International Nuclear Information System (INIS)

    Gyulai, J.

    1981-02-01

    The bases of Rutherford ion backscattering and its combination with channeling effect technique are reviewed. This combined method is recently referred to as Backscattering Spectrometry. The measurement of chemical compositions, the detection of crystal defects etc are dealt with. Comparison with other surface analysis methods is also given. The review was delivered as a lecture during the ''International School for Surface Physics'' (Varna, Bulgaria, Sep 18 - Oct 20, 1980). (author)

  8. Mass spectrometry in oceanography

    International Nuclear Information System (INIS)

    Aggarwal, Suresh K.

    2000-01-01

    Mass spectrometry plays an important role in oceanography for various applications. Different types of inorganic as well as organic mass spectrometric techniques are being exploited world-wide to understand the different aspects of marine science, for palaeogeography, palaeoclimatology and palaeoecology, for isotopic composition and concentrations of different elements as well as for speciation studies. The present paper reviews some of the applications of atomic mass spectrometric techniques in the area of oceanography

  9. Mass spectrometry with accelerators.

    Science.gov (United States)

    Litherland, A E; Zhao, X-L; Kieser, W E

    2011-01-01

    As one in a series of articles on Canadian contributions to mass spectrometry, this review begins with an outline of the history of accelerator mass spectrometry (AMS), noting roles played by researchers at three Canadian AMS laboratories. After a description of the unique features of AMS, three examples, (14)C, (10)Be, and (129)I are given to illustrate the methods. The capabilities of mass spectrometry have been extended by the addition of atomic isobar selection, molecular isobar attenuation, further ion acceleration, followed by ion detection and ion identification at essentially zero dark current or ion flux. This has been accomplished by exploiting the techniques and accelerators of atomic and nuclear physics. In 1939, the first principles of AMS were established using a cyclotron. In 1977 the selection of isobars in the ion source was established when it was shown that the (14)N(-) ion was very unstable, or extremely difficult to create, making a tandem electrostatic accelerator highly suitable for assisting the mass spectrometric measurement of the rare long-lived radioactive isotope (14)C in the environment. This observation, together with the large attenuation of the molecular isobars (13)CH(-) and (12)CH 2(-) during tandem acceleration and the observed very low background contamination from the ion source, was found to facilitate the mass spectrometry of (14)C to at least a level of (14)C/C ~ 6 × 10(-16), the equivalent of a radiocarbon age of 60,000 years. Tandem Accelerator Mass Spectrometry, or AMS, has now made possible the accurate radiocarbon dating of milligram-sized carbon samples by ion counting as well as dating and tracing with many other long-lived radioactive isotopes such as (10)Be, (26)Al, (36)Cl, and (129)I. The difficulty of obtaining large anion currents with low electron affinities and the difficulties of isobar separation, especially for the heavier mass ions, has prompted the use of molecular anions and the search for alternative

  10. A simple screening method for the determination of 230Th in soil and sediment samples by gamma-spectrometry

    International Nuclear Information System (INIS)

    Lozano, J.C.; Rodriguez, P.B.; Tome, F.V.

    2001-01-01

    A simple and easy to perform method for the determination of 230 Th in soil and sediment samples using gamma-spectrometry is proposed and compared with the more usual procedure using alpha-particle spectrometry. The proposed method involves an efficiency calibration for the specific determination of this radionuclide instead of a complete calibration of the spectra. A single density parameter is introduced to correct the efficiencies obtained from the reference sources. The activities of 230 Th determined by gamma-spectrometry and alpha-particle spectrometry are compared. The minimum detectable activity values obtained are completely adequate for 230 Th determination in soil and sediment samples, in which 230 Th activities are usually fairly high. Thus, this procedure is intended as a very easy way to obtain the activity of this radionuclide in these types of samples, at least as a screening method before carrying out other more laborious procedures. (author)

  11. Plutonium determination in urine by techniques of mass spectrometry; Determinacion de plutonio en orina por tecnicas de espectrometria de masas

    Energy Technology Data Exchange (ETDEWEB)

    Hernandez M, H. [ININ, Departamento de Quimica, Carretera Mexico-Toluca s/n, 52750 Ocoyoacac, Estado de Mexico (Mexico); Yllera de Ll, A., E-mail: hector.hernandez520@gmail.com [Centro de Investigaciones Energeticas, Medioambientales y Tecnologicas, Departamento de Medio Ambiente, Av. Complutense 22, 28040 Madrid (Spain)

    2013-10-15

    The objective of this study was to develop an analytic method for quantification and plutonium reappraisal in plane tables of alpha spectrometry be means of the mass spectrometry technique of high resolution with plasma source inductively coupled and desolvator Aridus (Aridus-Hr-Icp-Ms) and mass spectrometry with accelerator (AMS). The obtained results were, the recovery percentage of Pu in the plane table was of ∼ 90% and activity minimum detectable obtained with Aridus-Hr-Icp-Ms and AMS was of ∼ 3 and ∼ 0.4 f g of {sup 239}Pu, respectively. Conclusion, the results demonstrate the aptitude of the Aridus-Hr-Icp-Ms and AMS techniques in the Pu reappraisal in plane tables with bigger speed and precision, improving the values notably of the activity minimum detectable that can be obtained with the alpha spectrometry (∼ 50 f g of {sup 239}Pu). (author)

  12. Development of optical monitor of alpha radiations based on CR-39.

    Science.gov (United States)

    Joshirao, Pranav M; Shin, Jae Won; Vyas, Chirag K; Kulkarni, Atul D; Kim, Hojoong; Kim, Taesung; Hong, Seung-Woo; Manchanda, Vijay K

    2013-11-01

    Fukushima accident has highlighted the need to intensify efforts to develop sensitive detectors to monitor the release of alpha emitting radionuclides in the environment caused by the meltdown of the discharged spent fuel. Conventionally, proportional counting, scintillation counting and alpha spectrometry are employed to assay the alpha emitting radionuclides but these techniques are difficult to be configured for online operations. Solid State Nuclear Track Detectors (SSNTDs) offer an alternative off line sensitive technique to measure alpha emitters as well as fissile radionuclides at ultra-trace level in the environment. Recently, our group has reported the first ever attempt to use reflectance based fiber optic sensor (FOS) to quantify the alpha radiations emitted from (232)Th. In the present work, an effort has been made to develop an online FOS to monitor alpha radiations emitted from (241)Am source employing CR-39 as detector. Here, we report the optical response of CR-39 (on exposure to alpha radiations) employing techniques such as Atomic Force Microscopy (AFM) and Reflectance Spectroscopy. In the present work GEANT4 simulation of transport of alpha particles in the detector has also been carried out. Simulation includes validation test wherein the projected ranges of alpha particles in the air, polystyrene and CR-39 were calculated and were found to agree with the literature values. An attempt has been further made to compute the fluence as a function of the incidence angle and incidence energy of alphas. There was an excellent correlation in experimentally observed track density with the simulated fluence. The present work offers a novel approach to design an online CR-39 based fiber optic sensor (CRFOS) to measure the release of nanogram quantity of (241)Am in the environment. © 2013 Elsevier Ltd. All rights reserved.

  13. Classification of alpha 1-adrenoceptor subtypes

    NARCIS (Netherlands)

    Michel, M. C.; Kenny, B.; Schwinn, D. A.

    1995-01-01

    Two alpha 1-adrenoceptor subtypes (alpha 1A and alpha 1B) have been detected in various tissues by pharmacological techniques, and three distinct cDNAs encoding alpha 1-adrenoceptor subtypes have been cloned. The profile of an increasing number of subtype-selective compounds at cloned and endogenous

  14. Triplication of alpha-globin genes is responsible for unusual alpha 113Leu/alpha 113His-globin chain ratios in sheep.

    Science.gov (United States)

    Vestri, R; Masina, P; Rando, A; Testa, A; Di Gregorio, P

    1987-10-01

    By investigations at the DNA and protein level, it has been shown that in sheep a previously detected, presumed quantitative allele of the II alpha 113His gene, displaying a reduced efficiency (called the II alpha 113His decreases gene), is carried by a chromosome bearing three alpha-globin loci. In particular, five sheep having an alpha 113Leu/alpha 113His-chain ratio of about 13:1 (13:1 phenotype) possessed the -I alpha 113Leu-II alpha 113Leu-/-I alpha 113Leu-II alpha 113Leu-III alpha 113His decreases genotype. One sheep showing a alpha 113Leu/alpha 113His-chain ratio of about 3:1 (3:1 phenotype) had the -I alpha 113Leu-II alpha 113His-/-I alpha 113Leu-II alpha 113Leu-III alpha 113His decreases genotype, while one sheep having a chain ratio of about 6:1 (6:1 phenotype) carried the -I alpha 113Leu-II alpha 113Leu-II alpha 113His decreases-/-I alpha 113Leu-II alpha 113Leu-III alpha 113His decreases genotype. Nineteen sheep, displaying the common phenotypes, all possessed the alpha alpha/alpha alpha gene arrangement. Furthermore, the possible location of the gene with reduced efficiency and the expression of the three genes in the triple alpha-globin loci chromosome are discussed.

  15. Contribution to the study of the alpha-alpha interaction

    International Nuclear Information System (INIS)

    Darriulat, Pierre

    1965-01-01

    The new variable energy cyclotron at Berkeley that can accelerate an alpha beam up to an energy of 130 MeV and the mass production of lithium diffused junctions have enabled us to perform 2 series of measurement, in the first one we use alpha beams with an energy ranging between 50 and 120 MeV to study alpha-alpha forces in the second one we use the flexibility of the variable energy cyclotron the resonances around 40 MeV, region that can not yet be reached by tandem accelerators. This work is divided into 6 chapters. The first chapter is dedicated to the formalism of partial wave analysis and the theory of the compound nucleus. In the second chapter the author presents the 88 cyclotron at Berkeley and the diffusion chamber, the alpha detectors are lithium diffused junctions made of silicon. The third chapter deals with the experimental methods used and the issue of the reduction of the volume of data. In the fourth chapter the results obtained in the upper part of the energy range are described in terms of complex shifts that allow the description of the α-α interaction at high energy. The very low impact parameter has enabled us to find 2 new components (l=6 and l=8) of the rotational spectrum and to define a more accurate phenomenological potential. The fifth chapter is dedicated to the narrow resonances we have found between 12 and 27 MeV. We present in the last chapter a calculation of the binding energy of C 12 in which we have considered the 12 C nucleus as formed by 3 alpha particles interacting with each other through the phenomenological potential defined above

  16. High-resolution plasma spectrometry

    International Nuclear Information System (INIS)

    Edelson, M.C.

    1987-01-01

    In this chapter, the authors consider the topic of high-resolution plasma spectrometry (HRPS). Several different experimental approaches to HRPS are reviewed, and the benefits derived from increased spectral resolution are discussed. Results from the scientific literature are presented, but no attempt is made to provide an encyclopedic review. The discussion is limited to plasma emission spectrometry and, in particular, to inductively coupled plasma-atomic emission spectrometry (ICP-AES)

  17. Workshop on Precision Measurements of $\\alpha_s$

    Energy Technology Data Exchange (ETDEWEB)

    Bethke, Siegfried; /Munich, Max Planck Inst.; Hoang, Andre H.; /Vienna U.; Kluth, Stefan; /Munich, Max Planck Inst.; Schieck, Jochen; /Munich U.; Stewart, Iain W.; Aoki, S.; Beneke, M.; Bethke, S.; Blumlein, J.; Brambilla, N.; Brodsky, S.; /MIT, LNS

    2011-10-01

    These are the proceedings of the Workshop on Precision Measurements of {alpha}{sub s} held at the Max-Planck-Institute for Physics, Munich, February 9-11, 2011. The workshop explored in depth the determination of {alpha}{sub s}(m{sub Z}) in the {ovr MS} scheme from the key categories where high precision measurements are currently being made, including DIS and global PDF fits, {tau}-decays, electro-weak precision observables and Z-decays, event-shapes, and lattice QCD. These proceedings contain a short summary contribution from the speakers, as well as the lists of authors, conveners, participants, and talks.

  18. Sample Preprocessing For Atomic Spectrometry

    International Nuclear Information System (INIS)

    Kim, Sun Tae

    2004-08-01

    This book gives descriptions of atomic spectrometry, which deals with atomic absorption spectrometry such as Maxwell-Boltzmann equation and Beer-Lambert law, atomic absorption spectrometry for solvent extraction, HGAAS, ETASS, and CVAAS and inductively coupled plasma emission spectrometer, such as basic principle, generative principle of plasma and device and equipment, and interferences, and inductively coupled plasma mass spectrometry like device, pros and cons of ICP/MS, sample analysis, reagent, water, acid, flux, materials of experiments, sample and sampling and disassembling of sample and pollution and loss in open system and closed system.

  19. Mass spectrometry in clinical chemistry

    International Nuclear Information System (INIS)

    Pettersen, J.E.

    1977-01-01

    A brief description is given of the functional elements of a mass spectrometer and of some currently employed mass spectrometric techniques, such as combined gas chromatography-mass spectrometry, mass chromatography, and selected ion monitoring. Various areas of application of mass spectrometry in clinical chemistry are discussed, such as inborn errors of metabolism and other metabolic disorders, intoxications, quantitative determinations of drugs, hormones, gases, and trace elements, and the use of isotope dilution mass spectrometry as a definitive method for the establishment of true values for concentrations of various compounds in reference sera. It is concluded that mass spectrometry is of great value in clinical chemistry. (Auth.)

  20. Investigation of advanced materials for fusion alpha particle diagnostics

    Energy Technology Data Exchange (ETDEWEB)

    Bonheure, G., E-mail: g.bonheure@fz-juelich.de [Laboratory for Plasma Physics, Association “Euratom-Belgian State”, Royal Military Academy, Avenue de la Renaissance, 30 Kunstherlevinglaan, B-1000 Brussels (Belgium); Van Wassenhove, G. [Laboratory for Plasma Physics, Association “Euratom-Belgian State”, Royal Military Academy, Avenue de la Renaissance, 30 Kunstherlevinglaan, B-1000 Brussels (Belgium); Hult, M.; González de Orduña, R. [Institute for Reference Materials and Measurements (IRMM), Retieseweg 111, B-2440 Geel (Belgium); Strivay, D. [Centre Européen d’Archéométrie, Institut de Physique Nucléaire, Atomique et de Spectroscopie, Université de Liège (Belgium); Vermaercke, P. [SCK-CEN, Boeretang, B-2400 Mol (Belgium); Delvigne, T. [DSI SPRL, 3 rue Mont d’Orcq, Froyennes B-7503 (Belgium); Chene, G.; Delhalle, R. [Centre Européen d’Archéométrie, Institut de Physique Nucléaire, Atomique et de Spectroscopie, Université de Liège (Belgium); Huber, A.; Schweer, B.; Esser, G.; Biel, W.; Neubauer, O. [Forschungszentrum Jülich GmbH, Institut für Plasmaphysik, EURATOM-Assoziation, Trilateral Euregio Cluster, D-52425 Jülich (Germany)

    2013-10-15

    Highlights: ► We examine the feasibility of alpha particle measurements in ITER. ► We test advanced material detectors borrowed from the GERDA neutrino experiment. ► We compare experimental results on TEXTOR tokamak with our detector response model. ► We investigate the detector response in ITER full power D–T plasmas. ► Advanced materials show good signal to noise ratio and alpha particle selectivity. -- Abstract: Fusion alpha particle diagnostics for ITER remain a challenging task. Standard escaping alpha particle detectors in present tokamaks are not applicable to ITER and techniques suitable for fusion reactor conditions need further research and development [1,2]. The activation technique is widely used for the characterization of high fluence rates inside neutron reactors. Tokamak applications of the neutron activation technique are already well developed [3] whereas measuring escaping ions using this technique is a novel fusion plasma diagnostic development. Despite low alpha particle fluence levels in present tokamaks, promising results using activation technique combined with ultra-low level gamma-ray spectrometry [4] were achieved before in JET [5,6]. In this research work, we use new advanced detector materials. The material properties beneficial for alpha induced activation are (i) moderate neutron cross-sections (ii) ultra-high purity which reduces neutron-induced background activation and (iii) isotopic tailoring which increases the activation yield of the measured activation product. Two samples were obtained from GERDA[7], an experiment aimed at measuring the neutrinoless double beta decay in {sup 76}Ge. These samples, made of highly pure (9 N) germanium highly enriched to 87% in isotope Ge-76, were irradiated in real D–D fusion plasma conditions inside the TEXTOR tokamak. Comparison of the calculated and the experimentally measured activity shows good agreement. Compared to previously investigated high temperature ceramic material [8

  1. Conditioning of alpha bearing wastes

    International Nuclear Information System (INIS)

    1991-01-01

    Alpha bearing wastes are generated during the reprocessing of spent fuel, mixed oxide fuel fabrication, decommissioning and other activities. The safe and effective management of these wastes is of particular importance owing to the radiotoxicity and long lived characteristics of certain transuranic (TRU) elements. The management of alpha bearing wastes involves a number of stages which include collection, characterization, segregation, treatment, conditioning, transport, storage and disposal. This report describes the currently available matrices and technologies for the conditioning of alpha wastes and relates them to their compatibility with the other stages of the waste management process. The selection of a specific immobilization process is dependent on the waste treatment state and the subsequent handling, transport, storage and disposal requirements. The overall objectives of immobilization are similar for all waste producers and processors, which are to produce: (a) Waste forms with sufficient mechanical, physical and chemical stability to satisfy all stages of handling, transport and storage (referred to as the short term requirements), and (b) Waste forms which will satisfy disposal requirements and inhibit the release of radionuclides to the biosphere (referred to as the long term requirements). Cement and bitumen processes have already been successfully applied to alpha waste conditioning on the industrial scale in many of the IAEA Member States. Cement systems based on BFS and pozzolanic cements have emerged as the principal encapsulation matrices for the full range of alpha bearing wastes. Alternative technologies, such as polymers and ceramics, are being developed for specific waste streams but are unlikely to meet widespread application owing to cost and process complexity. The merits of alpha waste conditioning are improved performance in transport, storage and disposal combined with enhanced public perception of waste management operations. These

  2. Nanoscience, nanotechnology and spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Adams, Freddy C. [Department of Chemistry, University of Antwerp, B-2610 Wilrijk (Belgium); Barbante, Carlo, E-mail: barbante@unive.it [Institute for the Dynamics of Environmental Processes — CNR, Venice (Italy); Department of Environmental Sciences, Informatics and Statistics, Ca' Foscari University, Venice (Italy)

    2013-08-01

    Nanoscience has outgrown its infancy, and nanotechnology has found important applications in our daily life — with many more to come. Although the central concepts of the nano world, namely the changes of particular physical properties on the length scale of individual atoms and molecules, have been known and developed for quite some time already, experimental advances since the 1980s and recognition of the potential of nanomaterials led to a genuine breakthrough of the inherently multidisciplinary nanoscience field. Analytical nanoscience and nanotechnology and especially the use of micro and nano electro mechanical systems, of the quantum dots and of mass spectrometry, currently provide one of the most promising avenues for developments in analytical science, derived from their two main fields of action, namely (a) the analysis of nano-structured materials and (b) their use as new tools for analysis. An overview is given of recent developments and trends in the field, highlighting the importance and point out future directions, while also touching drawbacks, such as emerging concerns about health and environmental issues. - Highlights: • We review the analysis of nano-structured materials. • Nano-structured materials can be used as new tools for analysis. • Use of nano electro mechanical systems, of quantum dots and of mass spectrometry • Nanotechnologies are among the most promising tools in analytical science.

  3. Nanoscience, nanotechnology and spectrometry

    International Nuclear Information System (INIS)

    Adams, Freddy C.; Barbante, Carlo

    2013-01-01

    Nanoscience has outgrown its infancy, and nanotechnology has found important applications in our daily life — with many more to come. Although the central concepts of the nano world, namely the changes of particular physical properties on the length scale of individual atoms and molecules, have been known and developed for quite some time already, experimental advances since the 1980s and recognition of the potential of nanomaterials led to a genuine breakthrough of the inherently multidisciplinary nanoscience field. Analytical nanoscience and nanotechnology and especially the use of micro and nano electro mechanical systems, of the quantum dots and of mass spectrometry, currently provide one of the most promising avenues for developments in analytical science, derived from their two main fields of action, namely (a) the analysis of nano-structured materials and (b) their use as new tools for analysis. An overview is given of recent developments and trends in the field, highlighting the importance and point out future directions, while also touching drawbacks, such as emerging concerns about health and environmental issues. - Highlights: • We review the analysis of nano-structured materials. • Nano-structured materials can be used as new tools for analysis. • Use of nano electro mechanical systems, of quantum dots and of mass spectrometry • Nanotechnologies are among the most promising tools in analytical science

  4. Monitoring in vivo metabolism and elimination of the endogenous DNA adduct, M1dG {3-(2-deoxy-beta-D-erythro-pentofuranosyl)pyrimido[1,2-alpha]purin-10(3H)-one}, by accelerator mass spectrometry.

    Science.gov (United States)

    Knutson, Charles G; Skipper, Paul L; Liberman, Rosa G; Tannenbaum, Steven R; Marnett, Lawrence J

    2008-06-01

    Our laboratory is investigating the in vitro and in vivo metabolic processing of endogenously formed DNA adducts as a means of evaluating candidate urinary biomarkers. In particular, we have focused our studies on the metabolism and disposition of the peroxidation-derived pyrimidopurinone deoxyguanosine (dG) adduct, 3-(2-deoxy-beta-D-erythro-pentofuranosyl)pyrimido[1,2-R]purin-10(3H)-one (M1dG), and its principal metabolite, 6-oxo-M1dG. We now report the metabolic processing of M1dG at concentrations 4-8 orders of magnitude lower in concentration than previously analyzed, by the use of accelerator mass spectrometry analysis. Administration of 2.0 nCi/kg [14C]M1dG resulted in 49% of the 14C recovered in urine, whereas 51% was recovered in feces. In urine samples, approximately 40% of the 14C corresponded to the metabolite, 6-oxo-M1dG. Following iv administration of 0.5 and 54 pCi/kg [14C]M1dG, approximately 25% of the urinary recovery corresponded to the metabolite, 6-oxo-M1dG. Thus, upon administration of trace amounts of M1dG, a significant percentage of 6-oxo-M1dG was produced, suggesting that 6-oxo-M1dG maybe a useful urinary marker of exposure to endogenous oxidative damage.

  5. Negative chemical ionization mass spectrometry

    International Nuclear Information System (INIS)

    Smit, A.L.C.

    1979-01-01

    This thesis describes some aspects of Negative Chemical Ionization (NCI) mass spectrometry. The reasons for the growing interest in NCI are: (i) to extend the basic knowledge of negative ions and their reactions in the gas phase; (ii) to investigate whether or not this knowledge of negative ions can be used successfully to elucidate the structure of molecules by mass spectrometry. (Auth.)

  6. Laboratory of acceleration mass spectrometry

    International Nuclear Information System (INIS)

    Hybler, P.; Chrapan, J.

    2002-01-01

    In this paper authors describe the principle of the method of acceleration mass spectrometry and the construction plans of this instrument at the Faculty of ecology and environmental sciences in Banska Stiavnica. Using of this instrument for radiocarbon dating is discussed. A review of laboratories with acceleration mass spectrometry is presented

  7. Preface Miniaturization and Mass Spectrometry

    NARCIS (Netherlands)

    Unknown, [Unknown; le Gac, Severine; le Gac, S.; van den Berg, Albert; van den Berg, A.

    2009-01-01

    Miniaturization and Mass Spectrometry illustrates this trend and focuses on one particular analysis technique, mass spectrometry whose popularity has "dramatically" increased in the last two decades with the explosion of the field of biological analysis and the development of two "soft" ionization

  8. Improved Alpha Testing Using Hashed Sampling.

    Science.gov (United States)

    Wyman, Chris; McGuire, Morgan

    2017-08-14

    We further describe and analyze the idea of hashed alpha testing from Wyman and McGuire [1], which builds on stochastic alpha testing and simplifies stochastic transparency. Typically, alpha testing provides a simple mechanism to mask out complex silhouettes using simple proxy geometry with applied alpha textures. While widely used, alpha testing has a long-standing problem: geometry can disappear entirely as alpha mapped polygons recede with distance. As foveated rendering for virtual reality spreads, this problem worsens as peripheral minification and prefiltering introduce this problem on nearby objects.

  9. International Mass Spectrometry Society (IMSS).

    Science.gov (United States)

    Cooks, R G; Gelpi, E; Nibbering, N M

    2001-02-01

    This paper gives a brief description of the recently formalized International Mass Spectrometry Society (IMSS). It is presented here in order to increase awareness of the opportunities for collaboration in mass spectrometry in an international context. It also describes the recent 15th International Mass Spectrometry Conference, held August/September 2000, in Barcelona. Each of the authors is associated with the IMSS. The 15th Conference, which covers all of mass spectrometry on a triennial basis, was chaired by Professor Emilio Gelpi of the Instituto de Investigaciones Biomedicas, Barcelona. The outgoing and founding President of the IMSS is Professor Graham Cooks, Purdue University, and the incoming President is Professor Nico Nibbering, University of Amsterdam. Similar material has been provided to the Editors of other journals that cover mass spectrometry.

  10. ALPHA,·ANTITRYPSIN DEFICIENCY*

    African Journals Online (AJOL)

    1971-02-06

    Feb 6, 1971 ... Lieberman," in fact, found that 15·2% of 66 patients hospitalized with pulmonary emphysema had heterozygous alpha,-antitrypsin deficiency. The over-all incidence of the deficiency was 25'8% in this group. Of patients under the age of 50 years, 47·8% had deficient levels. If such observations are confirmed ...

  11. Accelerator-based ultrasensitive mass spectrometry

    International Nuclear Information System (INIS)

    Gove, H.E.

    1985-01-01

    This chapter describes a new mass spectrometry technique involving charged particle accelerators normally used for basic research in nuclear science. Topics considered include the limitations of conventional mass spectrometry, the limitations of the direct measurement of radioactive decay, mass spectrometry using a tandem electrostatic accelerator, mass spectrometry using a cyclotron, how accelerator mass spectrometry circumvents the limitations of conventional mass spectrometry, measurements of stable isotopes, nuclear physics and astrophysics applications, modifications to existing accelerators, descriptions of dedicated systems, and future applications

  12. The effect of a metalloproteinase inhibitor (GI5402) on tumor necrosis factor-alpha (TNF-alpha) and TNF-alpha receptors during human endotoxemia

    NARCIS (Netherlands)

    Dekkers, P. E.; Lauw, F. N.; ten Hove, T.; te Velde, A. A.; Lumley, P.; Becherer, D.; van Deventer, S. J.; van der Poll, T.

    1999-01-01

    Tumor necrosis factor-alpha (TNF-alpha) is released from the cell surface by cleavage of pro-TNF-alpha by metalloproteinases (MPs). In cell cultures, inhibition of MPs has been found not only to reduce the release of TNF-alpha, but also to enhance the surface expression of TNF-alpha and TNF-alpha

  13. Prion protein paralog doppel protein interacts with alpha-2-macroglobulin: a plausible mechanism for doppel-mediated neurodegeneration.

    Directory of Open Access Journals (Sweden)

    Stefano Benvegnù

    2009-06-01

    Full Text Available Doppel protein (Dpl is a paralog of the cellular form of the prion protein (PrP(C, together sharing common structural and biochemical properties. Unlike PrP(C, which is abundantly expressed throughout the central nervous system (CNS, Dpl protein expression is not detectable in the CNS. Interestingly, its ectopic expression in the brain elicits neurodegeneration in transgenic mice. Here, by combining native isoelectric focusing plus non-denaturing polyacrylamide gel electrophoresis and mass spectrometry analysis, we identified two Dpl binding partners: rat alpha-1-inhibitor-3 (alpha(1I(3 and, by sequence homology, alpha-2-macroglobulin (alpha(2M, two known plasma metalloproteinase inhibitors. Biochemical investigations excluded the direct interaction of PrP(C with either alpha(1I(3 or alpha(2M. Nevertheless, enzyme-linked immunosorbent assays and surface plasmon resonance experiments revealed a high affinity binding occurring between PrP(C and Dpl. In light of these findings, we suggest a mechanism for Dpl-induced neurodegeneration in mice expressing Dpl ectopically in the brain, linked to a withdrawal of natural inhibitors of metalloproteinase such as alpha(2M. Interestingly, alpha(2M has been proven to be a susceptibility factor in Alzheimer's disease, and as our findings imply, it may also play a relevant role in other neurodegenerative disorders, including prion diseases.

  14. Prion protein paralog doppel protein interacts with alpha-2-macroglobulin: a plausible mechanism for doppel-mediated neurodegeneration.

    Science.gov (United States)

    Benvegnù, Stefano; Franciotta, Diego; Sussman, Josh; Bachi, Angela; Zardini, Elisabetta; Torreri, Paola; Govaerts, Cedric; Pizzo, Salvatore; Legname, Giuseppe

    2009-06-18

    Doppel protein (Dpl) is a paralog of the cellular form of the prion protein (PrP(C)), together sharing common structural and biochemical properties. Unlike PrP(C), which is abundantly expressed throughout the central nervous system (CNS), Dpl protein expression is not detectable in the CNS. Interestingly, its ectopic expression in the brain elicits neurodegeneration in transgenic mice. Here, by combining native isoelectric focusing plus non-denaturing polyacrylamide gel electrophoresis and mass spectrometry analysis, we identified two Dpl binding partners: rat alpha-1-inhibitor-3 (alpha(1)I(3)) and, by sequence homology, alpha-2-macroglobulin (alpha(2)M), two known plasma metalloproteinase inhibitors. Biochemical investigations excluded the direct interaction of PrP(C) with either alpha(1)I(3) or alpha(2)M. Nevertheless, enzyme-linked immunosorbent assays and surface plasmon resonance experiments revealed a high affinity binding occurring between PrP(C) and Dpl. In light of these findings, we suggest a mechanism for Dpl-induced neurodegeneration in mice expressing Dpl ectopically in the brain, linked to a withdrawal of natural inhibitors of metalloproteinase such as alpha(2)M. Interestingly, alpha(2)M has been proven to be a susceptibility factor in Alzheimer's disease, and as our findings imply, it may also play a relevant role in other neurodegenerative disorders, including prion diseases.

  15. Calibration of sources for alpha spectroscopy systems

    International Nuclear Information System (INIS)

    Freitas, I.S.M.; Goncalez, O.L.

    1992-01-01

    This paper describes the calibration methodology for measuring the total alpha activity of plane and thin sources with the Alpha Spectrometer for Silicon Detector in the Nuclear Measures and Dosimetry laboratory at IEAv/CTA. (author)

  16. Potentialities of mass spectrometry (ICP-MS) for actinides determination in urine.

    Science.gov (United States)

    Bouvier-Capely, C; Ritt, J; Baglan, N; Cossonnet, C

    2004-05-01

    The applicability of inductively coupled plasma-mass spectrometry (ICP-MS) for determining actinides in urine was investigated. Performances of ICP-MS including detection limit and analysis time were studied and compared with alpha spectrometry performances. In the field of individual monitoring of workers, the comparison chart obtained in this study can be used as a guide for medical laboratories to select the most adequate procedure to be carried out depending on the case in question (the radioisotope to be measured, the required sensitivity, and the desired response time).

  17. Determination of the brominated flame retardant, hexabroomcyclodocane in sediments and biota by liquid chromatography-electrospray ionization mass spectrometry

    NARCIS (Netherlands)

    Morris, S.; Bersuder, P.; Allchin, C.R.; Zegers, B.; Boon, J.P.; Leonards, P.E.G.; Boer, de J.

    2006-01-01

    A method involving reversed-phase, liquid chromatography coupled to electrospray ionisation mass spectrometry (LC-ESI-MS) was developed for separation, detection and quantitation of the alpha-, beta- and gamma-diastereoisomers of hexabromocyclododecane (HBCD). To address the lack of environmental

  18. Enzyme replacement therapy for alpha-mannosidosis

    DEFF Research Database (Denmark)

    Borgwardt, Line Gutte; Dali, Christine I.; Fogh, J

    2013-01-01

    Alpha-mannosidosis (OMIM 248500) is a rare lysosomal storage disease (LSD) caused by alpha-mannosidase deficiency. Manifestations include intellectual disabilities, facial characteristics and hearing impairment. A recombinant human alpha-mannosidase (rhLAMAN) has been developed for weekly intrave...... intravenous enzyme replacement therapy (ERT). We present the preliminary data after 12 months of treatment....

  19. THE ALPHA/BETA-HYDROLASE FOLD

    NARCIS (Netherlands)

    OLLIS, DL; CHEAH, E; CYGLER, M; FROLOW, F; FRANKEN, SM; HAREL, M; REMINGTON, SJ; SILMAN, [No Value; SCHRAG, J; SUSSMAN, JL; VERSCHUEREN, KHG; GOLDMAN, A

    We have identified a new protein fold-the alpha/beta-hydrolase fold-that is common to several hydrolytic enzymes of widely differing phylogenetic origin and catalytic function. The core of each enzyme is similar: an alpha/beta-sheet, not barrel, of eight beta-sheets connected by alpha-helices. These

  20. Nature of the pygmy dipole resonance in Ce-140 studied in (alpha, alpha 'gamma) experiments

    NARCIS (Netherlands)

    Savran, D.; Babilon, M.; van den Berg, A.M.; Harakeh, M.N.; Hasper, J.; Matic, A.; Wörtche, H.J.; Zilges, A.

    2006-01-01

    A concentration of electric-dipole excitations below the particle threshold, which is frequently denoted as the pygmy dipole resonance, has been studied in the semimagic nucleus Ce-140 in (alpha, alpha(')gamma) experiments at E-alpha=136 MeV. The technique of alpha-gamma coincidence experiments

  1. Alpha-amylase Inhibition and Antioxidant Activity of Marine Green Algae and its Possible Role in Diabetes Management.

    Science.gov (United States)

    Unnikrishnan, P S; Suthindhiran, K; Jayasri, M A

    2015-10-01

    In the continuing search for safe and efficient antidiabetic drug, marine algae become important source which provide several compounds of immense therapeutic potential. Alpha-amylase, alpha-glucosidase inhibitors, and antioxidant compounds are known to manage diabetes and have received much attention recently. In the present study, four green algae (Chaetomorpha aerea, Enteromorpha intestinalis, Chlorodesmis, and Cladophora rupestris) were chosen to evaluate alpha-amylase, alpha-glucosidase inhibitory, and antioxidant activity in vitro. The phytochemical constituents of all the extracts were qualitatively determined. Antidiabetic activity was evaluated by inhibitory potential of extracts against alpha-amylase and alpha-glucosidase by spectrophotometric assays. Antioxidant activity was determined by 2,2-diphenyl-1-picrylhydrazyl, hydrogen peroxide (H2O2), and nitric oxide scavenging assay. Gas chromatography-mass spectrometry (GC-MS) analysis was carried out to determine the major compound responsible for its antidiabetic action. Among the various extracts screened, chloroform extract of C. aerea (IC50 - 408.9 μg/ml) and methanol extract of Chlorodesmis (IC50 - 147.6 μg/ml) showed effective inhibition against alpha-amylase. The extracts were also evaluated for alpha-glucosidase inhibition, and no observed activity was found. Methanol extract of C. rupestris showed notable free radical scavenging activity (IC50 - 666.3 μg/ml), followed by H2O2 (34%) and nitric oxide (49%). Further, chemical profiling by GC-MS revealed the presence of major bioactive compounds. Phenol, 2,4-bis (1,1-dimethylethyl) and z, z-6,28-heptatriactontadien-2-one were predominantly found in the methanol extract of C. rupestris and chloroform extract of C. aerea. Our results demonstrate that the selected algae exhibit notable alpha-amylase inhibition and antioxidant activity. Therefore, characterization of active compounds and its in vivo assays will be noteworthy. Four green algae were

  2. Decreased levels of genuine large free hCG alpha in men presenting with abnormal semen analysis

    Directory of Open Access Journals (Sweden)

    Plas Eugen

    2011-08-01

    Full Text Available Abstract Background The pregnancy hormone human chorionic gonadotropin (hCG and its free subunits (hCG alpha, hCG beta are produced in the male reproductive tract and found in high concentrations in seminal fluid, in particular hCG alpha. This study aimed to elucidate changes in peptide hormone profiles in patients showing abnormal semen analyses and to determine the genuineness of the highly abundant hCG alpha. Methods Seminal plasma was obtained from 45 male patients undergoing semen analysis during infertility workups. Comprehensive peptide hormone profiles were established by a panel of immunofluorometric assays for hCG, hCG alpha, hCG beta and its metabolite hCG beta core fragment, placental lactogen, growth hormone and prolactin in seminal plasma of patients with abnormal semen analysis results (n = 29 versus normozoospermic men (n = 16. The molecular identity of large hyperglycosylated hCG alpha was analyzed by mass-spectrometry and selective deglycosylation. Results hCG alpha levels were found to be significantly lower in men with impaired semen quality (1346 +/- 191 vs. 2753 +/- 533 ng/ml, P = 0.022. Moreover, patients with reduced sperm count had reduced intact hCG levels compared with normozoospermic men (0.097 +/- 0.022 vs. 0.203 +/- 0.040 ng/ml, P = 0.028. Using mass-spectrometry, the biochemical identity of hCG alpha purified from seminal plasma was verified. Under non-reducing conditions in SDS-PAGE, hCG alpha isolated from seminal plasma migrated in a manner comparable with large free hCG alpha with an apparent molecular mass (Mr, app of 24 kDa, while hCG alpha dissociated from pregnancy-derived holo-hCG migrated at approximately 22 kDa. After deglycosylation with PNGase F under denaturing conditions, all hCG alpha variants showed an Mr, app of 15 kDa, indicating identical amino acid backbones. Conclusions The findings indicate a pathophysiological relevance of hCG, particularly its free alpha subunit, in spermatogenesis. The

  3. Alternative splicing of T cell receptor (TCR) alpha chain transcripts containing V alpha 1 or V alpha 14 elements.

    Science.gov (United States)

    Mahotka, C; Hansen-Hagge, T E; Bartram, C R

    1995-10-01

    Human acute lymphoblastic leukemia cell lines represent valuable tools to investigate distinct steps of the complex regulatory pathways underlying T cell receptor recombination and expression. A case in point are V delta 2D delta 3 and subsequent V delta 2D delta 3J alpha rearrangements observed in human leukemic pre-B cells as well as in normal lymphopoiesis. The functional expression of these unusual (VD) delta (JC) alpha hybrids is almost exclusively prevented by alternative splicing events. In this report we show that alternative splicing at cryptic splice donor sites within V elements is not a unique feature of hybrid TCR delta/alpha transcripts. Among seven V alpha families analyzed by RT-PCR, alternatively spliced products were observed in TCR alpha recombinations containing V alpha 1 or V alpha 14 elements. In contrast to normal peripheral blood cells and thymocytes, the leukemia cell line JM expressing functional V alpha 1J alpha 3C alpha transcripts lacked evidence of aberrant TCR alpha RNA species.

  4. Alpha particles detection in nitrocellulose

    International Nuclear Information System (INIS)

    Romero C, M.

    1976-01-01

    The method for the manufacturing of the detection films follows these steps: preparation of the mass which includes nitrocellulose in the form of cotton as raw material ethyl acetate, cellosolve acetate, isopropyl and butyl alcohols as solvents and dioctyl phtalate as plasticiser; dilution of the paste; pouring of the diluted mass; and drying of the detection films. The results obtained experimentally are: The determination of the development times of the different thicknesses of the manufactured films. Response linearity of the detectors, variation of the number of tracks according to the distance of the source to the detector. Sizes of the diameter of the tracks depending of the distance detector-alpha emmission source. As a conclusion we can say the the nitrocellulose detectors are specific for alpha radiation; the more effective thicknesses in uranium prospecting works were those of 60 microns, since for the laboratory works the thicknesses of 30 to 40 microns were the ideal; the development technique of the detection films is simple and cheap and can be realized even in another place than the laboratory; this way of the manufacturing of nitrocellulose detection film sensitive to alpha nuclear radiation is open to future research. (author)

  5. Accelerator mass spectrometry.

    Science.gov (United States)

    Hellborg, Ragnar; Skog, Göran

    2008-01-01

    In this overview the technique of accelerator mass spectrometry (AMS) and its use are described. AMS is a highly sensitive method of counting atoms. It is used to detect very low concentrations of natural isotopic abundances (typically in the range between 10(-12) and 10(-16)) of both radionuclides and stable nuclides. The main advantages of AMS compared to conventional radiometric methods are the use of smaller samples (mg and even sub-mg size) and shorter measuring times (less than 1 hr). The equipment used for AMS is almost exclusively based on the electrostatic tandem accelerator, although some of the newest systems are based on a slightly different principle. Dedicated accelerators as well as older "nuclear physics machines" can be found in the 80 or so AMS laboratories in existence today. The most widely used isotope studied with AMS is 14C. Besides radiocarbon dating this isotope is used in climate studies, biomedicine applications and many other fields. More than 100,000 14C samples are measured per year. Other isotopes studied include 10Be, 26Al, 36Cl, 41Ca, 59Ni, 129I, U, and Pu. Although these measurements are important, the number of samples of these other isotopes measured each year is estimated to be less than 10% of the number of 14C samples. Copyright 2008 Wiley Periodicals, Inc.

  6. Measurement and analysis of $\\alpha$ particle induced reactions on yttrium

    CERN Document Server

    Singh, N L; Chintalapudi, S N

    2000-01-01

    Excitation functions for /sup 89/Y[( alpha ,3n); ( alpha ,4n); ( alpha , p3n); ( alpha , alpha n); ( alpha , alpha 2n)] reactions were measured up to 50 MeV using stacked foil activation technique and HPGe gamma ray spectroscopy method. The experimental data were compared with calculations considering equilibrium as well as preequilibrium reactions according to the hybrid model of Blann (ALICE/90). For ( alpha , xnyp) type of reactions, the precompound contributions are described by the model. There seems to be indications of direct inelastic scattering effects in ( alpha , alpha xn) type of reactions. To the best of our knowledge, the excitation functions for ( alpha ,4n), ( alpha , p3n), ( alpha , alpha n) and ( alpha , alpha 2n) reactions were measured for the first time. (23 refs).

  7. Measurement and analysis of alpha particle induced reactions on yttrium

    Energy Technology Data Exchange (ETDEWEB)

    Singh, N.L.; Gadkari, M.S. [Baroda Univ. (India). Dept. of Physics; Chintalapudi, S.N. [IUC-DAEF Calcutta Centre, Calcutta (India)

    2000-05-01

    Excitation functions for {sup 89}Y[({alpha},3n);({alpha},4n);({alpha},p3n);({alpha},{alpha}n);({alpha},{alpha}2n)] reactions were measured up to 50 MeV using stacked foil activation technique and HPGe gamma ray spectroscopy method. The experimental data were compared with calculations considering equilibrium as well as preequilibrium reactions according to the hybrid model of Blann (ALICE/90). For ({alpha},xnyp) type of reactions, the precompound contributions are described by the model. There seems to be indications of direct inelastic scattering effects in ({alpha},{alpha}xn) type of reactions. To the best of our knowledge, the excitation functions for ({alpha},4n), ({alpha},p3n), ({alpha},{alpha}n) and ({alpha},{alpha}2n) reactions were measured for the first time. (orig.)

  8. Fast neutron spectrometry and dosimetry

    International Nuclear Information System (INIS)

    Blaize, S.; Ailloud, J.; Mariani, J.; Millot, J.P.

    1958-01-01

    We have studied fast neutron spectrometry and dosimetry through the recoil protons they produce in hydrogenated samples. In spectrometric, we used nuclear emulsions, in dosimetric, we used polyethylene coated with zinc sulphide and placed before a photomultiplier. (author) [fr

  9. Functional genomics by mass spectrometry

    DEFF Research Database (Denmark)

    Andersen, Jens S.; Mann, M

    2000-01-01

    function, mass spectrometry is the method of choice. Mass spectrometry can now identify proteins with very high sensitivity and medium to high throughput. New instrumentation for the analysis of the proteome has been developed including a MALDI hybrid quadrupole time of flight instrument which combines...... advantages of the mass finger printing and peptide sequencing methods for protein identification. New approaches include the isotopic labeling of proteins to obtain accurate quantitative data by mass spectrometry, methods to analyze peptides derived from crude protein mixtures and approaches to analyze large...... numbers of intact proteins by mass spectrometry directly. Examples from this laboratory illustrate biological problem solving by modern mass spectrometric techniques. These include the analysis of the structure and function of the nucleolus and the analysis of signaling complexes....

  10. Mass Spectrometry of Halopyrazolium Salts

    DEFF Research Database (Denmark)

    Larsen, Elfinn; Egsgaard, Helge; Pande, U. C.

    1983-01-01

    Eleven halogen substituted 1-methyl-2-phenylpyrazolium bromides or chlorides were investigated by field desorption, field ionization, and electron impact mass spectrometry. Dealkylation was found to be the predominant thermal decomposition. An exchange between covalent and ionic halogen prior...

  11. Interferon Alpha in Systemic Lupus Erythematosus

    Directory of Open Access Journals (Sweden)

    Timothy B. Niewold

    2010-01-01

    Full Text Available The pleiotropic cytokine interferon alpha is involved in multiple aspects of lupus etiology and pathogenesis. Interferon alpha is important under normal circumstances for antiviral responses and immune activation. However, heightened levels of serum interferon alpha and expression of interferon response genes are common in lupus patients. Lupus-associated autoantibodies can drive the production of interferon alpha and heightened levels of interferon interfere with immune regulation. Several genes in the pathways leading to interferon production or signaling are associated with risk for lupus. Clinical and cellular manifestations of excess interferon alpha in lupus combined with the genetic risk factors associated with interferon make this cytokine a rare bridge between genetic risk and phenotypic effects. Interferon alpha influences the clinical picture of lupus and may represent a therapeutic target. This paper provides an overview of the cellular, genetic, and clinical aspects of interferon alpha in lupus.

  12. Novel alpha-mannosidase inhibitors; Nye alfa-mannosidaseinhibitorer

    Energy Technology Data Exchange (ETDEWEB)

    Farr, R.A.; Kang, M.S.; Peet, N.P.; Sunkara, S.P.

    1997-05-20

    [4S-(4{alpha}, 4a{beta}, 6{alpha}, 7{alpha}, 7a{alpha})]-Octahydro-1H-1-pyridine-4,5,6,7-tetrols and [4R-(4{alpha}, 4a{alpha}, 5{alpha}, 6{beta}, 7{beta}, 7a{beta})]-octahydro-1H-1-pyridine-4,5,6,7-tetrols are useful inhibitors of alpha-mannosidase and are useful immunostimulants, chemoprotective and radioprotective agents and antimetastatic agents.

  13. Development of thin foil Faraday collector as a lost alpha particle diagnostic for high yield D-T tokamak fusion plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Van Belle, P.; Jarvis, O.N.; Sadler, G.J. [Commission of the European Communities, Abingdon (United Kingdom). JET Joint Undertaking; Cecil, F.E. [Colorado School of Mines, Golden, CO (United States)

    1994-07-01

    Alpha particle confinement is necessary for ignition of a D-T tokamak fusion plasma and for first wall protection. Due to high radiation backgrounds and temperatures, scintillators and semiconductor detectors may not be used to study alpha particles which are lost to the first wall during the D-T programs on JET and ITER. An alternative method of charged particle spectrometry capable of operation in these harsh environments, is proposed: it consists of thin foils of electrically isolated conductors with the flux of alpha particles determined by the positive current flowing from the foils. 2 refs., 3 figs.

  14. Selection and generation of waveforms for differential mobility spectrometry.

    Science.gov (United States)

    Krylov, Evgeny V; Coy, Stephen L; Vandermey, John; Schneider, Bradley B; Covey, Thomas R; Nazarov, Erkinjon G

    2010-02-01

    Devices based on differential mobility spectrometry (DMS) are used in a number of ways, including applications as ion prefilters for API-MS systems, as detectors or selectors in hybrid instruments (GC-DMS, DMS-IMS), and in standalone systems for chemical detection and identification. DMS ion separation is based on the relative difference between high field and low field ion mobility known as the alpha dependence, and requires the application of an intense asymmetric electric field known as the DMS separation field, typically in the megahertz frequency range. DMS performance depends on the waveform and on the magnitude of this separation field. In this paper, we analyze the relationship between separation waveform and DMS resolution and consider feasible separation field generators. We examine ideal and practical DMS separation field waveforms and discuss separation field generator circuit types and their implementations. To facilitate optimization of the generator designs, we present a set of relations that connect ion alpha dependence to DMS separation fields. Using these relationships we evaluate the DMS separation power of common generator types as a function of their waveform parameters. Optimal waveforms for the major types of DMS separation generators are determined for ions with various alpha dependences. These calculations are validated by comparison with experimental data.

  15. Activator protein 2alpha mediates parathyroid TGF-alpha self-induction in secondary hyperparathyroidism.

    Science.gov (United States)

    Arcidiacono, Maria Vittoria; Cozzolino, Mario; Spiegel, Noah; Tokumoto, Masanori; Yang, Jing; Lu, Yan; Sato, Tetsuhiko; Lomonte, Carlo; Basile, Carlo; Slatopolsky, Eduardo; Dusso, Adriana S

    2008-10-01

    In secondary hyperparathyroidism, enhanced expression of TGF-alpha in the parathyroid leads to its own upregulation, generating a feed-forward loop for TGF-alpha activation of its receptor, EGFR receptor (EGFR), which promotes parathyroid hyperplasia. These studies examined the role of activator protein 2alpha (AP2), an inducer of TGF-alpha gene transcription, in the upregulation of parathyroid TGF-alpha in secondary hyperparathyroidism. In rat and human secondary hyperparathyroidism, parathyroid AP2 expression strongly correlated with TGF-alpha levels and with the rate of parathyroid growth, as expected. Furthermore, the increases in rat parathyroid content of AP2 and its binding to a consensus AP2 DNA sequence preceded the increase in TGF-alpha induced by high dietary phosphate. More significant, in A431 cells, which provide a model of enhanced TGF-alpha and TGF-alpha self-induction, mutating the core AP2 site of the human TGF-alpha promoter markedly impaired promoter activity induced by endogenous or exogenous TGF-alpha. Important for therapy, in five-sixths nephrectomized rats fed high-phosphate diets, inhibition of parathyroid TGF-alpha self-induction using erlotinib, a highly specific inhibitor of TGF-alpha/EGFR-driven signals, reduced AP2 expression dosage dependently. This suggests that the increases in parathyroid AP2 occur downstream of EGFR activation by TGF-alpha and are required for TGF-alpha self-induction. Indeed, in A431 cells, erlotinib inhibition of TGF-alpha self-induction caused parallel reductions in AP2 expression and nuclear localization, as well as TGF-alpha mRNA and protein levels. In summary, increased AP2 expression and transcriptional activity at the TGF-alpha promoter determine the severity of the hyperplasia driven by parathyroid TGF-alpha self-upregulation in secondary hyperparathyroidism.

  16. Flame emission, atomic absorption and fluorescence spectrometry

    International Nuclear Information System (INIS)

    Horlick, G.

    1980-01-01

    Six hundred and thirty references are cited in this review. The information in the review is divided into 12 major areas: books, reviews, and bibliographies; fundamental studies in flames; developments in instrumentation; measurement techniques and procedure; flame emission spectrometry; flame atomic absorption spectrometry; flame molecular absorption spectrometry; electrothermal atomization atomic absorption spectroscopy; hydride generation techniques; graphite furnace atomic emission spectrometry; atomic fluorescence spectrometry; and analytical comparisons

  17. Determination of substraces of alpha emitter elements in water

    International Nuclear Information System (INIS)

    Gascon, J.L.

    1990-01-01

    To determine alpha emitter elements in water by alpha spectrometry, it is necessary to use large volumes of samples, concentration techniq-ues and to separate the elements of interest. In this report a study is presented about two concentration techniques and the process of analysis. Firstly, the stages of concentration method by iron hydroxide coprecipitation were studied in order to improve the results. The combination of liquid-liquid extraction and ion exchange techniques was the best way. Secondly, the technique by adsorption on manganese dioxide was studied. To apply this technique it was necessary to develop analysis methods to separate uranium, thorium, plutonium, americium and radium. These methods were designed combining several techniques of separation: liquid-liquid extraction, liquid-solid extraction, ionic exchange and coprecipitation. After the analysis methods were developped the adsorption on manganese dioxide with artificial samples was studied in the laboratory. Finally, the method of adsorption on manganese dioxide was studied to determine uranium, thorium and radium in the drinking water of Madrid. (Author)

  18. Cluster secondary ion mass spectrometry microscope mode mass spectrometry imaging.

    Science.gov (United States)

    Kiss, András; Smith, Donald F; Jungmann, Julia H; Heeren, Ron M A

    2013-12-30

    Microscope mode imaging for secondary ion mass spectrometry is a technique with the promise of simultaneous high spatial resolution and high-speed imaging of biomolecules from complex surfaces. Technological developments such as new position-sensitive detectors, in combination with polyatomic primary ion sources, are required to exploit the full potential of microscope mode mass spectrometry imaging, i.e. to efficiently push the limits of ultra-high spatial resolution, sample throughput and sensitivity. In this work, a C60 primary source was combined with a commercial mass microscope for microscope mode secondary ion mass spectrometry imaging. The detector setup is a pixelated detector from the Medipix/Timepix family with high-voltage post-acceleration capabilities. The system's mass spectral and imaging performance is tested with various benchmark samples and thin tissue sections. The high secondary ion yield (with respect to 'traditional' monatomic primary ion sources) of the C60 primary ion source and the increased sensitivity of the high voltage detector setup improve microscope mode secondary ion mass spectrometry imaging. The analysis time and the signal-to-noise ratio are improved compared with other microscope mode imaging systems, all at high spatial resolution. We have demonstrated the unique capabilities of a C60 ion microscope with a Timepix detector for high spatial resolution microscope mode secondary ion mass spectrometry imaging. Copyright © 2013 John Wiley & Sons, Ltd.

  19. Isolation, characterization, and mechanistic studies of (-)-alpha-gurjunene synthase from Solidago canadensis.

    Science.gov (United States)

    Schmidt, C O; Bouwmeester, H J; Bülow, N; König, W A

    1999-04-15

    The leaves of the composite Solidago canadensis (goldenrod) were shown to contain (-)-alpha-gurjunene synthase activity. This sesquiterpene is likely to be the precursor for cyclocolorenone, a sesquiterpene ketone present in high amounts in S. canadensis leaves. (-)-alpha-Gurjunene synthase was purified to apparent homogeneity (741-fold) by anion-exchange chromatography (on several matrices), dye ligand chromatography, hydroxylapatite chromatography, and gel filtration. Chromatography on a gel filtration matrix indicated a native molecular mass of 48 kDa, and SDS-PAGE showed the enzyme to be composed of one subunit with a denatured mass of 60 kDa. Its maximum activity was observed at pH 7.8 in the presence of 10 mM Mg2+ and the KM value for the substrate farnesyl diphosphate was 5.5 microM. Over a range of purification steps (-)-alpha-gurjunene and (+)-gamma-gurjunene synthase activities copurified. In addition, the product ratio of the enzyme activity under several different assay conditions was always 91% (-)-alpha-gurjunene and 9% (+)-gamma-gurjunene. This suggests that the formation of these two structurally related products is catalyzed by one enzyme. For further confirmation, we carried out a number of mechanistic studies with (-)-alpha-gurjunene synthase, in which an enzyme preparation was incubated with deuterated substrate analogues. Based on mass spectrometry analysis of the products formed, a cyclization mechanism was postulated which makes it plausible that the synthase catalyzes the formation of both sesquiterpenes. Copyright 1999 Academic Press.

  20. Aromatization of 16alpha-hydroxyandrostenedione by human placental microsomes: effect of preincubation with suicide substrates of androstenedione aromatization.

    Science.gov (United States)

    Numazawa, Mitsuteru; Tachibana, Mii; Mutsumi, Ayako; Yoshimura, Akiko; Osawa, Yoshio

    2002-06-01

    Estrogen synthase (aromatase) catalyzes the aromatization of androstenedione (AD) as well as 16alpha-hydroxyandrostenedione (16alpha-OHAD) leading to estrone and estriol, respectively. We found that several steroid analogs including 4-hydroxyandrostenedione (1), 6-oxoandrostenedione (6-oxoAD, 2) and its 19-hydroxy analog (3), 10beta-acetoxyestr-5-ene-7,17-dione (4), androst-5-ene-4,7,17-trione (5), and 17alpha-ethynyl-19-norteststerone (6), which are known suicide inactivators of AD aromatization, are not effective in inactivating 16alpha-OHAD aromatization in a time-dependent manner. The compounds were tested with the use of human placental microsomes and 1beta-tritiated-16alpha-OHAD as the substrate. The results of the tritium water method of 16alpha-OHAD aromatization was confirmed by the gas chromatography-mass spectrometry (GC-MS) method of estriol formation. The 1beta-tritiated-AD was used to measure AD aromatization as a positive control for these experiments. The compounds were tested at concentrations up to 40-fold higher than the K(i)'s determined for inhibition of AD aromatization. These studies suggest that differences exist in the binding site structures responsible for aromatization of 16alpha-OHAD and AD.

  1. Alpha particle studies during JET DT experiments

    International Nuclear Information System (INIS)

    1999-01-01

    The 1997 DT experiment (DTE1) at the Joint European Torus included studies of the behaviour of alpha particles in high temperature plasmas. Clear alpha particle heating was observed in a series of otherwise similar 10MW hot-ion H-modes by scanning the DT mixture from 0%T to 93%T. Maxima in central temperature and energy content were obtained which corresponded with the maximum in fusion yield. Alfven Eigenmodes (AEs) have been detected in JET, driven by NBI or ICRH fast ions. However, in agreement with theory, no AE activity was observed in DT plasmas which could be attributed to alpha particle drive, except in the afterglow of some Optimised Shear pulses. Ion Cyclotron Emission (ICE) was detected at harmonics of the alpha particle cyclotron frequency at the outer edge of the plasma. The ICE is interpreted as being close to magnetoacoustic cyclotron instability, driven by inverted alpha distributions at the plasma edge. The high-energy neutral particle spectra showed features, which are ascribed to a mixture of alphas, neutralised by helium-like impurities, and deuterons, born from elastic collisions with alpha particles and neutralised by hydrogen-like impurities. The results of all these studies are consistent with classical alpha particle trapping and slowing-down. Future DT experiments will aim to increase alpha particle pressure, so interactions with plasma instabilities can be studied. The measurement of knock-on neutral triton spectra offers a clean way to determine confined alpha densities in these future experiments. (author)

  2. Alpha particle studies during JET DT experiments

    International Nuclear Information System (INIS)

    2001-01-01

    The 1997 DT experiment (DTE1) at the Joint European Torus included studies of the behaviour of alpha particles in high temperature plasmas. Clear alpha particle heating was observed in a series of otherwise similar 10MW hot-ion H-modes by scanning the DT mixture from 0%T to 93%T. Maxima in central temperature and energy content were obtained which corresponded with the maximum in fusion yield. Alfven Eigenmodes (AEs) have been detected in JET, driven by NBI or ICRH fast ions. However, in agreement with theory, no AE activity was observed in DT plasmas which could be attributed to alpha particle drive, except in the afterglow of some Optimised Shear pulses. Ion Cyclotron Emission (ICE) was detected at harmonics of the alpha particle cyclotron frequency at the outer edge of the plasma. The ICE is interpreted as being close to magnetoacoustic cyclotron instability, driven by inverted alpha distributions at the plasma edge. The high-energy neutral particle spectra showed features, which are ascribed to a mixture of alphas, neutralised by helium-like impurities, and deuterons, born from elastic collisions with alpha particles and neutralised by hydrogen-like impurities. The results of all these studies are consistent with classical alpha particle trapping and slowing-down. Future DT experiments will aim to increase alpha particle pressure, so interactions with plasma instabilities can be studied. The measurement of knock-on neutral triton spectra offers a clean way to determine confined alpha densities in these future experiments. (author)

  3. The Alpha Magnetic Spectrometer (AMS)

    CERN Document Server

    Alcaraz, J; Ambrosi, G; Anderhub, H; Ao, L; Arefev, A; Azzarello, P; Babucci, E; Baldini, L; Basile, M; Barancourt, D; Barão, F; Barbier, G; Barreira, G; Battiston, R; Becker, R; Becker, U; Bellagamba, L; Bene, P; Berdugo, J; Berges, P; Bertucci, B; Biland, A; Bizzaglia, S; Blasko, S; Bölla, G; Boschini, M; Bourquin, Maurice; Brocco, L; Bruni, G; Buénerd, M; Burger, J D; Burger, W J; Cai, X D; Camps, C; Cannarsa, P; Capell, M; Casadei, D; Casaus, J; Castellini, G; Cecchi, C; Chang, Y H; Chen, H F; Chen, H S; Chen, Z G; Chernoplekov, N A; Tzi Hong Chiueh; Chuang, Y L; Cindolo, F; Commichau, V; Contin, A; Crespo, P; Cristinziani, M; Cunha, J P D; Dai, T S; Deus, J D; Dinu, N; Djambazov, L; Dantone, I; Dong, Z R; Emonet, P; Engelberg, J; Eppling, F J; Eronen, T; Esposito, G; Extermann, P; Favier, Jean; Fiandrini, E; Fisher, P H; Flügge, G; Fouque, N; Galaktionov, Yu; Gervasi, M; Giusti, P; Grandi, D; Grimm, O; Gu, W Q; Hangarter, K; Hasan, A; Hermel, V; Hofer, H; Huang, M A; Hungerford, W; Ionica, M; Ionica, R; Jongmanns, M; Karlamaa, K; Karpinski, W; Kenney, G; Kenny, J; Kim, W; Klimentov, A; Kossakowski, R; Koutsenko, V F; Kraeber, M; Laborie, G; Laitinen, T; Lamanna, G; Laurenti, G; Lebedev, A; Lee, S C; Levi, G; Levchenko, P M; Liu, C L; Liu, H T; Lopes, I; Lu, G; Lü, Y S; Lübelsmeyer, K; Luckey, D; Lustermann, W; Maña, C; Margotti, A; Mayet, F; McNeil, R R; Meillon, B; Menichelli, M; Mihul, A; Mourao, A; Mujunen, A; Palmonari, F; Papi, A; Park, I H; Pauluzzi, M; Pauss, Felicitas; Perrin, E; Pesci, A; Pevsner, A; Pimenta, M; Plyaskin, V; Pozhidaev, V; Postolache, V; Produit, N; Rancoita, P G; Rapin, D; Raupach, F; Ren, D; Ren, Z; Ribordy, M; Richeux, J P; Riihonen, E; Ritakari, J; Röser, U; Roissin, C; Sagdeev, R; Sartorelli, G; Schwering, G; Scolieri, G; Seo, E S; Shoutko, V; Shoumilov, E; Siedling, R; Son, D; Song, T; Steuer, M; Sun, G S; Suter, H; Tang, X W; Ting, Samuel C C; Ting, S M; Tornikoski, M; Torsti, J; Ulbricht, J; Urpo, S; Usoskin, I; Valtonen, E; Vandenhirtz, J; Velcea, F; Velikhov, E P; Verlaat, B; Vetlitskii, I; Vezzu, F; Vialle, J P; Viertel, Gert M; Vitè, Davide F; Gunten, H V; Wallraff, W; Wang, B C; Wang, J Z; Wang, Y H; Wiik, K; Williams, C; Wu, S X; Xia, P C; Yan, J L; Yan, L G; Yang, C G; Yang, M; Ye, S W; Yeh, P; Xu, Z Z; Zhang, H Y; Zhang, Z P; Zhao, D X; Zhu, G Y; Zhu, W Z; Zhuang, H L; Zichichi, A; Zimmermann, B

    2002-01-01

    The Alpha Magnetic Spectrometer (AMS) is a large acceptance (0.65 sr m sup 2) detector designed to operate in the International Space Station (ISS) for three years. The purposes of the experiment are to search for cosmic antimatter and dark matter and to study the composition and energy spectrum of the primary cosmic rays. A 'scaled-down' version has been flown on the Space Shuttle Discovery for 10 days in June 1998. The complete AMS is programmed for installation on the ISS in October 2003 for an operational period of 3 yr. This contribution reports on the experimental configuration that will be installed on the ISS.

  4. Targeted alpha therapy for cancer

    Energy Technology Data Exchange (ETDEWEB)

    Allen, Barry J [Centre for Experimental Radiation Oncology, St George Cancer Care Centre, Gray St, Kogarah 2217, NSW (Australia); Raja, Chand [Centre for Experimental Radiation Oncology, St George Cancer Care Centre, Gray St, Kogarah 2217, NSW (Australia); Rizvi, Syed [Centre for Experimental Radiation Oncology, St George Cancer Care Centre, Gray St, Kogarah 2217, NSW (Australia); Li Yong [Centre for Experimental Radiation Oncology, St George Cancer Care Centre, Gray St, Kogarah 2217, NSW (Australia); Tsui, Wendy [Centre for Experimental Radiation Oncology, St George Cancer Care Centre, Gray St, Kogarah 2217, NSW (Australia); Zhang, David [Centre for Experimental Radiation Oncology, St George Cancer Care Centre, Gray St, Kogarah 2217, NSW (Australia); Song, Emma [Centre for Experimental Radiation Oncology, St George Cancer Care Centre, Gray St, Kogarah 2217, NSW (Australia); Qu, C F [Centre for Experimental Radiation Oncology, St George Cancer Care Centre, Gray St, Kogarah 2217, NSW (Australia); Kearsley, John [Centre for Experimental Radiation Oncology, St George Cancer Care Centre, Gray St, Kogarah 2217, NSW (Australia); Graham, Peter [Centre for Experimental Radiation Oncology, St George Cancer Care Centre, Gray St, Kogarah 2217, NSW (Australia); Thompson, John [Sydney Melanoma Unit, Royal Prince Alfred Hospital, Camperdown 2050 NSW (Australia)

    2004-08-21

    Targeted alpha therapy (TAT) offers the potential to inhibit the growth of micrometastases by selectively killing isolated and preangiogenic clusters of cancer cells. The practicality and efficacy of TAT is tested by in vitro and in vivo studies in melanoma, leukaemia, colorectal, breast and prostate cancers, and by a phase 1 trial of intralesional TAT for melanoma. The alpha-emitting radioisotope used is Bi-213, which is eluted from the Ac-225 generator and chelated to a cancer specific monoclonal antibody (mab) or protein (e.g. plasminogen activator inhibitor-2 PAI2) to form the alpha-conjugate (AC). Stable alpha-ACs have been produced which have been tested for specificity and cytotoxicity in vitro against melanoma (9.2.27 mab), leukaemia (WM60), colorectal (C30.6), breast (PAI2, herceptin), ovarian (PAI2, herceptin, C595), prostate (PAI2, J591) and pancreatic (PAI2, C595) cancers. Subcutaneous inoculation of 1-1.5 million human cancer cells into the flanks of nude mice causes tumours to grow in all mice. Tumour growth is compared for untreated controls, nonspecific AC and specific AC, for local (subcutaneous) and systemic (tail vein or intraperitoneal) injection models. The {sup 213}Bi-9.2.27 AC is injected into secondary skin melanomas in stage 4 patients in a dose escalation study to determine the effective tolerance dose, and to measure kinematics to obtain the equivalent dose to organs. In vitro studies show that TAT is one to two orders of magnitude more cytotoxic to targeted cells than non-specific ACs, specific beta emitting conjugates or free isotopes. In vivo local TAT at 2 days post-inoculation completely prevents tumour formation for all cancers tested so far. Intra-lesional TAT can completely regress advanced sc melanoma but is less successful for breast and prostate cancers. Systemic TAT inhibits the growth of sc melanoma xenografts and gives almost complete control of breast and prostate cancer tumour growth. Intralesional doses up to 450 {mu

  5. The Alpha Magnetic Spectrometer (ams)

    Science.gov (United States)

    Ionica, Maria

    2004-01-01

    The Alpha Magnetic Spectrometer (AMS), once installed on the International Space Station will provide precise measurements of the cosmic ray spectra up to TeV energy range, and will search for cosmological antimatter and missing matter. A prototype version of the detector was operated successfully on the space shuttle Discovery in June 1998 (STS-91). Here we briefly report on the design of the AMS apparatus and present the results of the measurements of the fluxes of proton, electron, positron and helium from the STS-91 flight.

  6. Crossing symmetry in Alpha space

    CERN Multimedia

    CERN. Geneva

    2017-01-01

    The conformal bootstrap program aims to catalog all conformal field theories (second-order phase transitions) in D dimensions. Despite its ambitious scope much progress has been made over the past decade, e.g. in computing critical exponents for the 3D O(N) models to high precision. At this stage, analytic methods to explore the CFT landscape are not as well developed. In this talk I will describe a new mathematical framework for the bootstrap known as "alpha space", which reduces crossing symmetry to a set of integral equations. Based on arXiv:1702.08471 (with Balt van Rees) and arXiv:1703.08159.

  7. The Alpha Magnetic Spectrometer (AMS)

    International Nuclear Information System (INIS)

    Alcaraz, J.; Alpat, B.; Ambrosi, G.; Anderhub, H.; Ao, L.; Arefiev, A.; Azzarello, P.; Babucci, E.; Baldini, L.; Basile, M.; Barancourt, D.; Barao, F.; Barbier, G.; Barreira, G.; Battiston, R.; Becker, R.; Becker, U.; Bellagamba, L.; Bene, P.; Berdugo, J.; Berges, P.; Bertucci, B.; Biland, A.; Bizzaglia, S.; Blasko, S.; Boella, G.; Boschini, M.; Bourquin, M.; Brocco, L.; Bruni, G.; Buenerd, M.; Burger, J.D.; Burger, W.J.; Cai, X.D.; Camps, C.; Cannarsa, P.; Capell, M.; Casadei, D.; Casaus, J.; Castellini, G.; Cecchi, C.; Chang, Y.H.; Chen, H.F.; Chen, H.S.; Chen, Z.G.; Chernoplekov, N.A.; Chiueh, T.H.; Chuang, Y.L.; Cindolo, F.; Commichau, V.; Contin, A.; Crespo, P.; Cristinziani, M.; Cunha, J.P. da; Dai, T.S.; Deus, J.D.; Dinu, N.; Djambazov, L.; DAntone, I.; Dong, Z.R.; Emonet, P.; Engelberg, J.; Eppling, F.J.; Eronen, T.; Esposito, G.; Extermann, P.; Favier, J.; Fiandrini, E.; Fisher, P.H.; Fluegge, G.; Fouque, N.; Galaktionov, Yu.; Gervasi, M.; Giusti, P.; Grandi, D.; Grimm, O.; Gu, W.Q.; Hangarter, K.; Hasan, A.; Hermel, V.; Hofer, H.; Huang, M.A.; Hungerford, W.; Ionica, M.; Ionica, R.; Jongmanns, M.; Karlamaa, K.; Karpinski, W.; Kenney, G.; Kenny, J.; Kim, W.; Klimentov, A.; Kossakowski, R.; Koutsenko, V.; Kraeber, M.; Laborie, G.; Laitinen, T.; Lamanna, G.; Laurenti, G.; Lebedev, A.; Lee, S.C.; Levi, G.; Levtchenko, P.; Liu, C.L.; Liu, H.T.; Lopes, I.; Lu, G.; Lu, Y.S.; Luebelsmeyer, K.; Luckey, D.; Lustermann, W.; Mana, C.; Margotti, A.; Mayet, F.; McNeil, R.R.; Meillon, B.; Menichelli, M.; Mihul, A.; Mourao, A.; Mujunen, A.; Palmonari, F.; Papi, A.; Park, I.H.; Pauluzzi, M.; Pauss, F.; Perrin, E.; Pesci, A.; Pevsner, A.; Pimenta, M.; Plyaskin, V.; Pojidaev, V.; Postolache, V.; Produit, N.; Rancoita, P.G.; Rapin, D.; Raupach, F.; Ren, D.; Ren, Z.; Ribordy, M.; Richeux, J.P.; Riihonen, E.; Ritakari, J.; Roeser, U.; Roissin, C.; Sagdeev, R.; Sartorelli, G.; Schultz von Dratzig, A.; Schwering, G.; Scolieri, G.; Seo, E.S.; Shoutko, V.; Shoumilov, E.; Siedling, R.; Son, D.; Song, T.; Steuer, M.; Sun, G.S.; Suter, H.; Tang, X.W.; Ting, S.C.C.Samuel C.C.; Ting, S.M.; Tornikoski, M.; Torsti, J.; Tr umper, J.; Ulbricht, J.; Urpo, S.; Usoskin, I.; Valtonen, E.; Vandenhirtz, J.; Velcea, F.; Velikhov, E.; Verlaat, B.; Vetlitsky, I.; Vezzu, F.; Vialle, J.P.; Viertel, G.; Vite, D.; Gunten, H. Von; Wicki, S.W.S. Waldmeier; Wallraff, W.; Wang, B.C.; Wang, J.Z.; Wang, Y.H.; Wiik, K.; Williams, C.; Wu, S.X.; Xia, P.C.; Yan, J.L.; Yan, L.G.; Yang, C.G.; Yang, M.; Ye, S.W.; Yeh, P.; Xu, Z.Z.; Zhang, H.Y.; Zhang, Z.P.; Zhao, D.X.; Zhu, G.Y.; Zhu, W.Z.; Zhuang, H.L.; Zichichi, A.; Zimmermann, B.

    2002-01-01

    The Alpha Magnetic Spectrometer (AMS) is a large acceptance (0.65 sr m 2 ) detector designed to operate in the International Space Station (ISS) for three years. The purposes of the experiment are to search for cosmic antimatter and dark matter and to study the composition and energy spectrum of the primary cosmic rays. A 'scaled-down' version has been flown on the Space Shuttle Discovery for 10 days in June 1998. The complete AMS is programmed for installation on the ISS in October 2003 for an operational period of 3 yr. This contribution reports on the experimental configuration that will be installed on the ISS

  8. Renal Amyloidosis Associated With 5 Novel Variants in the Fibrinogen A Alpha Chain Protein.

    Science.gov (United States)

    Rowczenio, Dorota; Stensland, Maria; de Souza, Gustavo A; Strøm, Erik H; Gilbertson, Janet A; Taylor, Graham; Rendell, Nigel; Minogue, Shane; Efebera, Yvonne A; Lachmann, Helen J; Wechalekar, Ashutosh D; Hawkins, Philip N; Heimdal, Ketil R; Selvig, Kristian; Lægreid, Inger K; Demoulin, Nathalie; Aydin, Selda; Gillmore, Julian D; Wien, Tale N

    2017-05-01

    Fibrinogen A alpha chain amyloidosis is an autosomal dominant disease associated with mutations in the fibrinogen A alpha chain ( FGA ) gene, and it is the most common cause of hereditary renal amyloidosis in the UK. Patients typically present with kidney impairment and progress to end-stage renal disease over a median time of 4.6 years. Six patients presented with proteinuria, hypertension, and/or lower limb edema and underwent detailed clinical and laboratory investigations. A novel FGA gene mutation was identified in each case: 2 frameshift mutations F521Sfs*27 and G519Efs*30 and 4 single base substitutions G555F, E526K, E524K, R554H. In 5 subjects, extensive amyloid deposits were found solely within the glomeruli, which stained specifically with antibodies to fibrinogen A alpha chain, and in one of these cases, we found coexistent fibrinogen A alpha chain amyloidosis and anti-glomerular basement membrane antibody disease. One patient was diagnosed with light-chain amyloidosis after a bone marrow examination revealed a small clonal plasma cell population, and laser microdissection of the amyloid deposits followed by liquid chromatography and tandem mass spectrometry identified kappa light chain as the fibril protein. We report 6 novel mutations in the FGA gene: 5 were associated with renal fibrinogen A alpha chain amyloidosis and 1 was found to be incidental to light-chain amyloid deposits discovered in a patient with a plasma cell dyscrasia. Clinical awareness and suspicion of hereditary amyloidosis corroborated by genetic analysis and adequate typing using combined immunohistochemistry and laser microdissection and mass spectrometry is valuable to avoid misdiagnosis, especially when a family history of amyloidosis is absent.

  9. Burn-up determination of irradiated thoria samples by isotope dilution-thermal ionisation mass spectrometry

    International Nuclear Information System (INIS)

    Aggarwal, S.K.; Jaison, P.G.; Telmore, V.M.; Shah, R.V.; Sant, V.L.; Sasibhushan, K.; Parab, A.R.; Alamelu, D.

    2010-03-01

    Burn-up was determined experimentally using thermal ionization mass spectrometry for two samples from ThO 2 bundles irradiated in KAPS-2. This involved quantitative dissolution of the irradiated fuel samples followed by separation and determination of Th, U and a stable fission product burn-up monitor in the dissolved fuel solution. Stable fission product 148 Nd was used as a burn-up monitor for determining the number of fissions. Isotope Dilution-Thermal Ionisation Mass Spectrometry (ID-TIMS) using natural U, 229 Th and enriched 142 Nd as spikes was employed for the determination of U, Th and Nd, respectively. Atom % fission values of 1.25 ± 0.03 were obtained for both the samples. 232 U content in 233 U determined by alpha spectrometry was about 500 ppm and this was higher by a factor of 5 compared to the theoretically predicted value by ORIGEN-2 code. (author)

  10. Symposium on accelerator mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    None

    1981-01-01

    The area of accelerator mass spectrometry has expanded considerably over the past few years and established itself as an independent and interdisciplinary research field. Three years have passed since the first meeting was held at Rochester. A Symposium on Accelerator Mass Spectrometry was held at Argonne on May 11-13, 1981. In attendance were 96 scientists of whom 26 were from outside the United States. The present proceedings document the program and excitement of the field. Papers are arranged according to the original program. A few papers not presented at the meeting have been added to complete the information on the status of accelerator mass spectrometry. Individual papers were prepared separately for the data base.

  11. Mass spectrometry. [in organic chemistry

    Science.gov (United States)

    Burlingame, A. L.; Shackleton, C. H. L.; Howe, I.; Chizhov, O. S.

    1978-01-01

    A review of mass spectrometry in organic chemistry is given, dealing with advances in instrumentation and computer techniques, selected topics in gas-phase ion chemistry, and applications in such fields as biomedicine, natural-product studies, and environmental pollution analysis. Innovative techniques and instrumentation are discussed, along with chromatographic-mass spectrometric on-line computer techniques, mass spectral interpretation and management techniques, and such topics in gas-phase ion chemistry as electron-impact ionization and decomposition, photoionization, field ionization and desorption, high-pressure mass spectrometry, ion cyclotron resonance, and isomerization reactions of organic ions. Applications of mass spectrometry are examined with respect to bio-oligomers and their constituents, biomedically important substances, microbiology, environmental organic analysis, and organic geochemistry.

  12. Symposium on accelerator mass spectrometry

    International Nuclear Information System (INIS)

    1981-01-01

    The area of accelerator mass spectrometry has expanded considerably over the past few years and established itself as an independent and interdisciplinary research field. Three years have passed since the first meeting was held at Rochester. A Symposium on Accelerator Mass Spectrometry was held at Argonne on May 11-13, 1981. In attendance were 96 scientists of whom 26 were from outside the United States. The present proceedings document the program and excitement of the field. Papers are arranged according to the original program. A few papers not presented at the meeting have been added to complete the information on the status of accelerator mass spectrometry. Individual papers were prepared separately for the data base

  13. Quantum Estimates of Alpha Emitter Life Time

    Directory of Open Access Journals (Sweden)

    B. Santoso

    2006-01-01

    Full Text Available Quantum estimates of several alpha radioactive life time have been made using the probability of quantum tunneling through the nuclear potential barrier. It is assumed that for a given nucleus with mass number A and isotopic number Z, there exists an alpha particle moving freely back and forth in the nucleus with mass and isotopic numbers A -4 and Z-2. If the probability of penetrating the nuclear potential barrier is Τ, then after N times (N=1/Τ hitting the barrier an alpha particle is emitted. To obtain the elapsed time for emitting an alpha particle requires N times τ0, where τ0 is the time travel for alpha across the nuclear diameter, which is dependent on alpha energy. It is assumed here that this kinetic energy is the same as the emitted energy. The emitting alpha kinetic energies here are calculated by the difference of the masses of the parent and daughter nuclei and the alpha particles. They are in closed agreement with the experimental observations. While the alpha radioactive life time are not the same order of magnitudes but give the same linearity on the logarithmic scale as function of the inverse square root of energy.

  14. Sterically hindered C(alpha, alpha)-disubstituted alpha-amino acids: synthesis from alpha-nitroacetate and incorporation into peptides.

    Science.gov (United States)

    Fu, Y; Hammarström, L G; Miller, T J; Fronczek, F R; McLaughlin, M L; Hammer, R P

    2001-10-19

    The preparation of sterically hindered and polyfunctional C(alpha,alpha)-disubstituted alpha-amino acids (alpha alpha AAs) via alkylation of ethyl nitroacetate and transformation into derivatives ready for incorporation into peptides are described. Treatment of ethyl nitroacetate with N,N-diisopropylethylamine (DIEA) in the presence of a catalytic amount of tetraalkylammonium salt, followed by the addition of an activated alkyl halide or Michael acceptor, gives the doubly C-alkylated product in good to excellent yields. Selective nitro reduction with Zn in acetic acid or hydrogen over Raney Ni gives the corresponding amino ester that, upon saponification, can be protected with the fluorenylmethyloxycarbonyl (Fmoc) group. The first synthesis of an orthogonally protected, tetrafunctional C(alpha,alpha)-disubstituted analogue of aspartic acid, 2,2-bis(tert-butylcarboxymethyl)glycine (Bcmg), is described. Also, the sterically demanding C(alpha,alpha)-dibenzylglycine (Dbg) has been incorporated into a peptide using solid-phase synthesis. It was found that once sterically congested Dbg is at the peptide N-terminus, further chain extension becomes very difficult using uronium or phosphonium salts (PyAOP, PyAOP/HOAt, HATU). However, preformed amino acid symmetrical anhydride couples to N-terminal Dbg in almost quantitative yield in nonpolar solvent (dichloroethane-DMF, 9:1).

  15. Mass spectrometry for biomarker development

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Chaochao; Liu, Tao; Baker, Erin Shammel; Rodland, Karin D.; Smith, Richard D.

    2015-06-19

    Biomarkers potentially play a crucial role in early disease diagnosis, prognosis and targeted therapy. In the past decade, mass spectrometry based proteomics has become increasingly important in biomarker development due to large advances in technology and associated methods. This chapter mainly focuses on the application of broad (e.g. shotgun) proteomics in biomarker discovery and the utility of targeted proteomics in biomarker verification and validation. A range of mass spectrometry methodologies are discussed emphasizing their efficacy in the different stages in biomarker development, with a particular emphasis on blood biomarker development.

  16. Coincidence gamma-ray spectrometry

    DEFF Research Database (Denmark)

    Markovic, Nikola; Roos, Per; Nielsen, Sven Poul

    2017-01-01

    Gamma-ray spectrometry with high-purity germanium (HPGe) detectors is often the technique of choice in an environmental radioactivity laboratory. When measuring environmental samples associated activities are usually low so an important parameter that describes the performance of the spectrometer...... for a nuclide of interest is the minimum detectable activity (MDA). There are many ways for lowering the MDAs in gamma spectrometry. Recently, developments of fast and compact digital acquisition systems have led to growing number of multiple HPGe detector spectrometers. In these applications all detected...

  17. Application of isotopic dillution techniques by alpha and mass spechometry for determining uranium and evaluated its distributIon in geological materials

    International Nuclear Information System (INIS)

    Shihomatsu, H.M.

    1987-01-01

    Determination of uranium in the concentration range of 2 to 4000 ppm in nuclear raw materials by mass spectrometric (MSID) and alpha spectrometric isotope dilution techniques (ASID), using the isotope tracer enriched in 233 U, is presented. An investigation on the nature of the thermoionic emission in various types of filament arrangements like, single plane rhenium, single boat and double, are carried out for the isotope analysis by mass spectrometry. In the preparation of the sources for alpha spectrometry by electrodeposition the experimental parameters such as: current density, pH of the mixed solution containing sample and electrolyte, concentration of the electrolyte solution, time of deposition and distance between electrodes are optimised. The accuracy of the technique is discussed based on the determination of uranium in the same samples by other research workers employing various analytical techniques including mass spectrometric and alpha spectrometric isotope dilution techniques (MSID and ASID). (author) [pt

  18. Use of positive ion fast atom bombardment mass spectrometry for rapid identification of a bile alcohol glucuronide isolated from cerebrotendinous xanthomatosis patients

    International Nuclear Information System (INIS)

    Dayal, B.; Salen, G.; Tint, G.S.; Shefer, S.; Benz, S.W.

    1990-01-01

    The identification of a major biliary and plasma bile alcohol glucuronide, 5 beta-cholestane-3 alpha, 7 alpha, 12 alpha, 25-tetrol-3-0-beta-D-glucuronide, present in cerebrotendinous xanthomatosis (CTX) patients, was investigated by positive ion fast atom bombardment mass spectrometry (FAB-MS). The spectrum was characterized by abundant ions formed by attachment of a proton, [M + H]+, or of alkali ions, [M + Na]+ and [M + 39K]+, to the glucuronide salt. These ions allowed an unambiguous deduction of the molecular weight of the sample. It is suggested that FAB-MS could be used in the rapid diagnosis of CTX

  19. Gas chromatography-mass spectrometry/mass spectrometry analysis to determine natural and post-administration levels of oestrogens in bovine serum and urine

    Energy Technology Data Exchange (ETDEWEB)

    Biddle, S. [HFL, Newmarket Road, Fordham, Cambridgeshire (United Kingdom)]. E-mail: sbiddle@hfl.co.uk; Teale, P. [HFL, Newmarket Road, Fordham, Cambridgeshire (United Kingdom); Robinson, A. [HFL, Newmarket Road, Fordham, Cambridgeshire (United Kingdom); Bowman, J. [HFL, Newmarket Road, Fordham, Cambridgeshire (United Kingdom); Houghton, E. [HFL, Newmarket Road, Fordham, Cambridgeshire (United Kingdom)

    2007-03-14

    A novel analytical approach has been developed and shown to be capable of detecting the isomers of oestradiol in the low ppt (pg mL{sup -1}) range in bovine serum and urine. Following extractive derivatisation the analytes were detected as their 3-pentafluorobenzoyl 17-trimethylsilyl ether derivatives by gas chromatography-mass spectrometry/mass spectrometry (GC-MS/MS), using electron capture negative ion chemical ionisation. The isomers of oestradiol were quantified in both blank and post-administration urine and serum samples, with a view to setting action/threshold levels for these compounds, to allow discrimination between normal samples and samples from animals treated with growth promoting ear implants. A non-parametric statistical assessment of the data resulted in proposed action levels (with a false positive probability of 1 in 1000) of 1.6 and 2.7 ng mL{sup -1} for 17{alpha}-oestradiol, in male and female urine, respectively, and 40 and 44 pg mL{sup -1} for 17{beta}-oestradiol, in male and female urine, respectively. An action level of 20 pg mL{sup -1} was proposed for 17{alpha}- and 17{beta}-oestradiol in male serum. In female serum the proposed action levels were 40 and 20 pg mL{sup -1} for 17{alpha}- and 17{beta}-oestradiol, respectively.

  20. Hypothalamic PGC-1 alpha Protects Against High-Fat Diet Exposure by Regulating ER alpha

    NARCIS (Netherlands)

    Morselli, Eugenia; Fuente-Martin, Esther; Finan, Brian; Kim, Min; Frank, Aaron; Garcia-Caceres, Cristina; Navas, Carlos Rodriguez; Gordillo, Ruth; Neinast, Michael; Kalainayakan, Sarada P.; Li, Dan L.; Gao, Yuanqing; Yi, Chun-Xia; Hahner, Lisa; Palmer, Biff F.; Tschöp, Matthias H.; Clegg, Deborah J.

    2014-01-01

    High-fat diets (HFDs) lead to obesity and inflammation in the central nervous system (CNS). Estrogens and estrogen receptor alpha (ER alpha) protect premenopausal females from the metabolic complications of inflammation and obesity-related disease. Here, we demonstrate that hypothalamic PGC-1 alpha

  1. Tumor necrosis factor alpha (TNF alpha) in human skin : A comparison of different antibodies for immunohistochemistry

    NARCIS (Netherlands)

    van der Laan, N; de Leij, LFMH; Buurman, W; Timens, W; ten Duis, HJ

    Conflicting results have been reported regarding the localization and presence of TNF alpha in normal human skin, To study TNF alpha expression, we tested a panel of antibodies directed against human TNF alpha, First, antibodies were tested for immunoreactivity on cytospots of isolated

  2. Study of the pygmy dipole resonance in Mo-94 using the (alpha, alpha ' gamma) coincidence technique

    NARCIS (Netherlands)

    Derya, V.; Endres, J.; Elvers, M.; Harakeh, M. N.; Pietralla, N.; Romig, C.; Savran, D.; Scheck, M.; Siebenhuehner, F.; Stoica, V. I.; Wortche, H. J.; Zilges, A.

    2013-01-01

    The (alpha, alpha' gamma) reaction at E-alpha = 136 MeV was used to study the electric dipole response in the open-shell vibrational nucleus Mo-94 below the neutron-separation threshold. The coincidence experiment has been performed at the Kernfysisch Versneller Instituut in Groningen, The

  3. Increased Circulating Levels of Alpha-Ketoglutarate in Morbidly Obese Women with Non-Alcoholic Fatty Liver Disease.

    Directory of Open Access Journals (Sweden)

    Gemma Aragonès

    Full Text Available Non-alcoholic fatty liver disease (NAFLD causes a wide spectrum of liver damage, ranging from simple steatosis to cirrhosis. However, simple steatosis (SS and steatohepatitis (NASH cannot yet be distinguished by clinical or laboratory features. The aim of this study was to assess the relationship between alpha-ketoglutarate and the degrees of NAFLD in morbidly obese patients.We used a gas chromatography-quadruple time-of-flight-mass spectrometry analysis to quantify alpha-ketoglutarate in serum from normal-weight subjects (n = 30 and morbidly obese women (n = 97 with or without NAFLD.We found that serum levels of alpha-ketoglutarate were significantly higher in morbidly obese women than in normal-weight women. We showed that circulating levels of alpha-ketoglutarate were lower in lean controls and morbidly obese patients without NAFLD. We also found that alpha-ketoglutarate serum levels were higher in both SS and NASH than in normal liver of morbidly obese patients. However, there was no difference between SS and NASH. Moreover, we observed that circulating levels of alpha-ketoglutarate were associated with glucose metabolism parameters, lipid profile, hepatic enzymes and steatosis degree. In addition, diagnostic performance of alpha-ketoglutarate has been analyzed in NAFLD patients. The AUROC curves from patients with liver steatosis exhibited an acceptable clinical utility. Finally, we showed that the combination of biomarkers (AST, ALT and alpha-ketoglutarate had the highest accuracy in diagnosing liver steatosis.These findings suggest that alpha-ketoglutarate can determine the presence of non-alcoholic fatty liver in morbidly obese patients but it is not valid a biomarker for NASH.

  4. X-ray fluorescence spectrometry

    International Nuclear Information System (INIS)

    Vries, J.L. de.

    1976-01-01

    The seventh edition of Philips' Review of Literature on x-ray fluorescence spectrometry starts with a list of conference proceedings on the subject, organised by the Philips organisation at regular intervals in various European countries. It is followed by a list of bulletins. The bibliography is subdivided according to spectra, equipment, applications and absorption analysis

  5. Mass spectrometry with particle accelerator

    International Nuclear Information System (INIS)

    Anon.

    1983-01-01

    The heavy ion accelerator use is renewing the ultrasensitive mass spectrometry in extending the detection limits. These new devices allow the measurement of rare isotope ratio, as 10 Be, 14 C, 26 Al, 36 Cl or 41 Ca, from the earth natural reservoirs [fr

  6. Gamma and X 93 spectrometry

    International Nuclear Information System (INIS)

    1994-05-01

    The Meetings of Gamma and X 93 Spectrometry were held on 12-14 October 1993. The symposium was organized into six sessions: Instrumentation development, Nuclear matter measurement, Method and calibration, Medical applications, Environment survey (radioactive traces measurement), other applications (spent fuels analysis, various techniques). Separate abstracts were prepared for all the papers in this volume. (TEC)

  7. Mass Spectrometry Instrumentation in Proteomics

    DEFF Research Database (Denmark)

    Sprenger, Richard Remko; Roepstorff, Peter

    2012-01-01

    Mass spectrometry has evolved into a crucial technology for the field of proteomics, enabling the comprehensive study of proteins in biological systems. Innovative developments have yielded flexible and versatile mass spectrometric tools, including quadrupole time-of-flight, linear ion trap...

  8. Mass spectrometry in epigenetic research

    DEFF Research Database (Denmark)

    Beck, Hans Christian

    2010-01-01

    cancers has gained tremendous interest in recent years, and many of these inhibitors are currently undergoing clinical trials. Despite intense research, however, the exact molecular mechanisms of action of these molecules remain, to a wide extent, unclear. The recent application of mass spectrometry...

  9. Fully automated system for Pu measurement by gamma spectrometry of alpha contaminated solid wastes

    International Nuclear Information System (INIS)

    Cresti, P.

    1986-01-01

    A description is given of a fully automated system developed at Comb/Mepis Laboratories which is based on the detection of specific gamma signatures of Pu isotopes for monitoring Pu content in 15-25 l containers of low density (0.1 g/cm 3 ) wastes. The methodological approach is discussed; based on experimental data, an evaluation of the achievable performances (detection limit, precision, accuracy, etc.) is also given

  10. Standard test method for radiochemical determination of uranium isotopes in urine by alpha spectrometry

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2011-01-01

    1.1 This test method is applicable to the determination of uranium in urine at levels of detection dependent on sample size, count time, detector background, and tracer yield. It is designed as a screening tool for detection of possible exposure of occupational workers. 1.2 This test method is designed for 50 mL of urine. This test method does not address the sampling protocol or sample preservation methods associated with its use. 1.3 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard. 1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

  11. Determination of the isotopic composition of natural and slightly enriched uranium by alpha-spectrometry

    DEFF Research Database (Denmark)

    Kunzendorf, Helmar

    1968-01-01

    Determinations of the isotope contents of 238U, 235U and 234U in five uranium samples containing 0–5 at% 235U were carried out on the basis of a least-squares fit of the α-spectra from the samples, measured with a semiconductor detector, to the theoretically expected α-spectra. With a simple source...

  12. A procedure for the determination of Po-210 in water samples by alpha spectrometry

    International Nuclear Information System (INIS)

    2009-01-01

    Reliable, comparable and 'fit for purpose' results are an essential requirement for any decision based on analytical measurements. For the analyst, the availability of tested and validated analytical procedures is a extremely important tool for production of such analytical measurements. For maximum utility, such procedures should be comprehensive, clearly formulated, and readily available to both the analyst and the customer for reference. Since 2004 the Environment programme of the IAEA has included activities aimed at the development of a set of procedures for the determination of radionuclides in terrestrial environmental samples. In the case of 210 Po, this started with the collection and review of about 130 papers from the scientific literature. Based on this review, two candidate methods for the chemical separation of 210 Po from water samples were selected for testing, refinement and validation in accordance with ISO guidelines. A comprehensive methodology for calculation of results including quantification of measurement uncertainty was also developed. This report presents the final procedure which was developed based on that work

  13. Psychiatric Symptoms in Alpha-Mannosidosis

    Science.gov (United States)

    Malm, D.; Pantel, J.; Linaker, O. M.

    2005-01-01

    Alpha-mannosidosis is characterized by mild to moderate intellectual disability (ID), moderate to severe neurosensory hearing loss, frequent infections, psychomotor disturbances and skeletal dysmorphism. For the first time, a panel of nine alpha-mannosidosis patients with psychiatric symptoms is presented. The clinical picture has several…

  14. Coefficient Alpha Bootstrap Confidence Interval under Nonnormality

    Science.gov (United States)

    Padilla, Miguel A.; Divers, Jasmin; Newton, Matthew

    2012-01-01

    Three different bootstrap methods for estimating confidence intervals (CIs) for coefficient alpha were investigated. In addition, the bootstrap methods were compared with the most promising coefficient alpha CI estimation methods reported in the literature. The CI methods were assessed through a Monte Carlo simulation utilizing conditions…

  15. Alpha Shape Topology of the Cosmic Web

    NARCIS (Netherlands)

    Weygaert, Rien van de; Platen, Erwin; Vegter, Gert; Eldering, Bob; Kruithof, Nico

    2010-01-01

    We study the topology of the Megaparsec Cosmic Web on the basis of the Alpha Shapes of the galaxy distribution. The simplicial complexes of the alpha shapes are used to determine the set of Betti numbers (βk, k = 1, . . . , D), which represent a complete characterization of the topology of a

  16. Central and peripheral alpha-adrenoceptors

    NARCIS (Netherlands)

    van Zwieten, P A; van Meel, J. C. A.; de Jonge, A; Wilffert, B; Timmermans, P B

    1982-01-01

    The recent interest in the characterization and functional, role of alpha-adrenoceptors has prompted us to study the following different, although interdigitated, lines of research: (a) The functional role of calcium ions in the process of vasoconstriction, induced by alpha 2-adrenoceptor

  17. Producing alpha-olefins using polyketide synthases

    Energy Technology Data Exchange (ETDEWEB)

    Fortman, Jeffrey L.; Katz, Leonard; Steen, Eric J.; Keasling, Jay D.

    2018-01-02

    The present invention provides for a polyketide synthase (PKS) capable of synthesizing an .alpha.-olefin, such as 1-hexene or butadiene. The present invention also provides for a host cell comprising the PKS and when cultured produces the .alpha.-olefin.

  18. Bayesian Meta-Analysis of Coefficient Alpha

    Science.gov (United States)

    Brannick, Michael T.; Zhang, Nanhua

    2013-01-01

    The current paper describes and illustrates a Bayesian approach to the meta-analysis of coefficient alpha. Alpha is the most commonly used estimate of the reliability or consistency (freedom from measurement error) for educational and psychological measures. The conventional approach to meta-analysis uses inverse variance weights to combine…

  19. ALPHA experiment facility and Prof. Jeffrey Hangst.

    CERN Multimedia

    Maximilien Brice

    2010-01-01

    Picture 01-07: General views of the ALPHA experiment Picture 5: Andrea Gutierrez, a PhD student from UBC, transfers liquid helium from a storage dewar into the cryostat containing the superconducting magnetic trap used by the ALPHA experiment.Picture 08-11: Jeffery Hangst, spokesperson for ALPHA Picture 12: The ALPHA silicon detector, which surrounds the trapping resion and is used for imaging antiproton annihilations (Credit University of Liverpool) Picture 13: Untrapped antihydrogen atoms annihilating on the inner surface of the ALPHA trap. These are measured by the ALPHA annihilation detector. The events are concentrated at the electrode radius of about 22.3 mm. The coordinates are defined in the Nature article, Figure 1b. Picture 14: The electrodes (gold) for the ALPHA Penning trap being inserted into the vacuum chamber and cryostat assembly. This is the trap used to combine or "mix" positrons and antiprotons to make antihydrogen. (Credit: Niels Madsen ALPHA/Swansea.) Picture 15: Top, a diagram of the...

  20. Alpha-1 Antitrypsin Deficiency (Inherited Emphysema)

    Science.gov (United States)

    ... antitrypsin inactivates elastase once it has finished its job. Without alpha 1 antitrypsin, elastase can destroy the air sacs of the lung. How is the diagnosis made? Because Alpha-1 related disease is COPD, the diagnosis is made by the same methods. Your doctor may have you do a number ...

  1. A stable lipid-induced aggregate of alpha-synuclein

    NARCIS (Netherlands)

    Drescher, Malte; van Rooijen, Bart D; Veldhuis, Gertjan; Subramaniam, Vinod; Huber, Martina

    2010-01-01

    The Parkinson's disease-related protein alpha-Synuclein (alphaS) is a 140 residue intrinsically disordered protein. Its membrane-binding properties are thought to be relevant for its physiological or pathologic activity. Here, the interaction of alphaS with POPG

  2. Technical Basis for the Use of Alpha Absorption Corrections on RCF Gross Alpha Data

    International Nuclear Information System (INIS)

    Ceffalo, G.M.

    1999-01-01

    This document provides the supporting data and rationale for making absorption corrections to gross alpha data to correct alpha data for loss due to absorption in the sample matrix. For some time there has been concern that the gross alpha data produced by the Environmental Restoration Contractor Radiological Counting Facility, particularly gross alpha analysis on soils, has been biased toward low results, as no correction for self-absorption was applied to the counting data. The process was investigated, and a new methodology for alpha self-absorption has been developed

  3. Measurement of radon progeny concentrations in air by alpha-particle spectrometey

    International Nuclear Information System (INIS)

    Kerr, G.D.

    1975-07-01

    A technique is presented for measuring air concentrations of the short-lived progeny of radon-222 by the use of alpha spectrometry. In this technique, the concentration of RaA, RaB, and RaC are calculated from one integral count of the RaA and two integral counts of the RaC' alpha-particle activity collected on a filter with an air sampling device. The influence of air sampling and counting intervals of time on the accuracy of the calculated concentrations is discussed in the report. A computer program is presented for use with this technique. It is written in the BASIC language. The program will calculate the air concentrations of RaA, RaB, and RaC, and will estimate the accuracy in these calculated concentrations. (U.S.)

  4. Quantitative autoradiography of alpha particle emission in geo-materials using the Beaver™ system

    International Nuclear Information System (INIS)

    Sardini, Paul; Angileri, Axel; Descostes, Michael; Duval, Samuel; Oger, Tugdual; Patrier, Patricia; Rividi, Nicolas; Siitari-Kauppi, Marja; Toubon, Hervé; Donnard, Jérôme

    2016-01-01

    In rocks or artificial geo-materials, radioactive isotopes emitting alpha particles are dispersed according to the mineralogy. At hand specimen scale, the achievement of quantitative chemical mapping of these isotopes takes on a specific importance. Knowledge of the distribution of the uranium and thorium series radionuclides is of prime interest to several disciplines, from the geochemistry of uranium deposits, to the dispersion of uranium mill tailings in the biosphere. The disequilibrium of these disintegration chains is also commonly used for dating. However, some prime importance isotopes, such as 226 Ra, are complicated to localize in geo-materials. Because of its high specific activity, 226 Ra is found in very low concentrations (~ppq), preventing its accurate localization in rock forming minerals. This paper formulates a quantitative answer to the following question: at hand specimen scale, how can alpha emitters in geo-materials be mapped quantitatively? In this study, we tested a new digital autoradiographic method (called the Beaver™) based on a Micro Patterned Gaseous Detector (MPGD) in order to quantitatively map alpha emission at the centimeter scale rock section. Firstly, for two thin sections containing U-bearing minerals at secular equilibrium, we compared the experimental and theoretical alpha count rates, measured by the Beaver™ and calculated from the uranium content, respectively. We found that they are very similar. Secondly, for a set of eight homemade standards made up of a mixture of inactive sand and low-radioactivity mud, we compared the count rates obtained by the Beaver™ and by an alpha spectrometer. The results indicate (i) a linearity between both count rates, and (ii) that the count obtained by the Beaver™ can be estimated from the count obtained by the alpha spectrometry using a factor of 0.82.

  5. Quantitative autoradiography of alpha particle emission in geo-materials using the Beaver™ system

    Energy Technology Data Exchange (ETDEWEB)

    Sardini, Paul; Angileri, Axel [IC2MP Equipe HydrASA, 6 Rue Michel Brunet, B35, TSA 51106 Poitiers Cedex 9 (France); Descostes, Michael [AREVA Mines, R& D Department, Paris (France); Duval, Samuel; Oger, Tugdual [AI4R SAS, Nantes (France); Patrier, Patricia [IC2MP Equipe HydrASA, 6 Rue Michel Brunet, B35, TSA 51106 Poitiers Cedex 9 (France); Rividi, Nicolas [Service Camparis, Université Pierre et Marie Curie, Paris (France); Siitari-Kauppi, Marja [Radiochemistry Laboratory, University of Helsinki, Helsinki (Finland); Toubon, Hervé [AREVA Mines, R& D Department, Paris (France); Donnard, Jérôme [AI4R SAS, Nantes (France)

    2016-10-11

    In rocks or artificial geo-materials, radioactive isotopes emitting alpha particles are dispersed according to the mineralogy. At hand specimen scale, the achievement of quantitative chemical mapping of these isotopes takes on a specific importance. Knowledge of the distribution of the uranium and thorium series radionuclides is of prime interest to several disciplines, from the geochemistry of uranium deposits, to the dispersion of uranium mill tailings in the biosphere. The disequilibrium of these disintegration chains is also commonly used for dating. However, some prime importance isotopes, such as {sup 226}Ra, are complicated to localize in geo-materials. Because of its high specific activity, {sup 226}Ra is found in very low concentrations (~ppq), preventing its accurate localization in rock forming minerals. This paper formulates a quantitative answer to the following question: at hand specimen scale, how can alpha emitters in geo-materials be mapped quantitatively? In this study, we tested a new digital autoradiographic method (called the Beaver™) based on a Micro Patterned Gaseous Detector (MPGD) in order to quantitatively map alpha emission at the centimeter scale rock section. Firstly, for two thin sections containing U-bearing minerals at secular equilibrium, we compared the experimental and theoretical alpha count rates, measured by the Beaver™ and calculated from the uranium content, respectively. We found that they are very similar. Secondly, for a set of eight homemade standards made up of a mixture of inactive sand and low-radioactivity mud, we compared the count rates obtained by the Beaver™ and by an alpha spectrometer. The results indicate (i) a linearity between both count rates, and (ii) that the count obtained by the Beaver™ can be estimated from the count obtained by the alpha spectrometry using a factor of 0.82.

  6. Solid-supported enzymatic synthesis of pectic oligogalacturonides and their analysis by MALDI-TOF mass spectrometry

    DEFF Research Database (Denmark)

    Guillaumie, Fanny; Sterling, J.D.; Jensen, K.J.

    2003-01-01

    Solid-phase biosynthetic reactions, followed by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry analysis (MALDI-TOF), was used to gain insight into the biosynthesis of pectin oligomers. Sepharose supports bearing long pectic oligogalacturonides (OGAs) anchored through...... into the liquid phases by MALDI-TOF mass spectrometry. In time course studies conducted with an immobilized (alpha-D-GalA)(14) and limiting amounts of the glycosyl donor, the predominant product was an OGA extended by one GalA residue at the non-reducing end (i.e., (GalA)(15)). When UDP-GalA was added...

  7. Determination of alpha_s using jet cross section parameterizations at hadron colliders

    CERN Document Server

    Stenzel, H

    2001-01-01

    Precise measurements of the single inclusive jet cross section have been performed by the TEVATRON experiments and will be provided by the LHC experiments extending to larger values of transverse energy. Theoretical predictions of this observable at NLO in perturbative QCD depend both on the PDF parameterization set and on the value of the strong coupling constant alpha_s. In this paper the dependence of the jet cross section on alpha_s is investigated. A method is presented to extract alpha_s(E_T) from a cross section measurement based on a parameterization of the alpha_s dependence. Systematic uncertainties and the E_T-range of applicability are discussed. A comparative study is performed between the case of ppbar at sqrt{s}=1.8 TeV (TEVATRON) and pp scattering at sqrt{s}=14 TeV (LHC).

  8. Alpha1 and Alpha2 Integrins Mediate Invasive Activity of Mouse Mammary Carcinoma Cells through Regulation of Stromelysin-1 Expression

    Energy Technology Data Exchange (ETDEWEB)

    Lochter, Andre; Navre, Marc; Werb, Zena; Bissell, Mina J

    1998-06-29

    Tumor cell invasion relies on cell migration and extracellular matrix proteolysis. We investigated the contribution of different integrins to the invasive activity of mouse mammary carcinoma cells. Antibodies against integrin subunits {alpha}6 and {beta}1, but not against {alpha}1 and {alpha}2, inhibited cell locomotion on a reconstituted basement membrane in two-dimensional cell migration assays, whereas antibodies against {beta}1, but not against a6 or {alpha}2, interfered with cell adhesion to basement membrane constituents. Blocking antibodies against {alpha}1 integrins impaired only cell adhesion to type IV collagen. Antibodies against {alpha}1, {alpha}2, {alpha}6, and {beta}1, but not {alpha}5, integrin subunits reduced invasion of a reconstituted basement membrane. Integrins {alpha}1 and {alpha}2, which contributed only marginally to motility and adhesion, regulated proteinase production. Antibodies against {alpha}1 and {alpha}2, but not {alpha}6 and {beta}1, integrin subunits inhibited both transcription and protein expression of the matrix metalloproteinase stromelysin-1. Inhibition of tumor cell invasion by antibodies against {alpha}1 and {alpha}2 was reversed by addition of recombinant stromelysin-1. In contrast, stromelysin-1 could not rescue invasion inhibited by anti-{alpha}6 antibodies. Our data indicate that {alpha}1 and {alpha}2 integrins confer invasive behavior by regulating stromelysin-1 expression, whereas {alpha}6 integrins regulate cell motility. These results provide new insights into the specific functions of integrins during tumor cell invasion.

  9. Study on influences of experimental factors on energy and absolute activity measurements of alpha-emitters

    International Nuclear Information System (INIS)

    Terini, R.A.

    1991-01-01

    This work presents firstly a review of the fundamental results and conclusions obtained through alpha-spectrometry and alpha-counting, and the influence of energy straggling, energy loss, self-absorption and backscattering, on the determination of the energy and the absolute activity of alpha samples. Is is shown that the techniques of source fabrication and the methods of measurements play a capital influence on the obtained results. Moreover, measurements made by us, with a silicon surface barrier detector, show that the peak-asymmetry and peak-shift of an alpha-spectrum increases with the angle of emission, and that the magnitude of this effect depends on the thickness and homogeneity of the sample, as well as on the geometry of the measuring system. Through an analysis of the angular distribution of the emitted particles, the degree of isotropy of some thin Am sup(241) sources was measured and the influence of source backing and the geometry was analysed. We can conclude that, in general, there is a larger precision in measurements made under very small solid angles around the normal to the sample, and we enphasize the necessary cares required on the production of the source and on the set up of the measuring system. (author)

  10. Mapping High-Velocity H-alpha and Lyman-alpha Emission from Supernova 1987A

    Science.gov (United States)

    France, Kevin; McCray, Richard; Fransson, Claes; Larsson, Josefin; Frank, Kari A.; Burrows, David N.; Challis, Peter; Kirshner, Robert P.; Chevalier, Roger A.; Garnavich, Peter; hide

    2015-01-01

    We present new Hubble Space Telescope images of high-velocity H-alpha and Lyman-alpha emission in the outer debris of SN 1987A. The H-alpha images are dominated by emission from hydrogen atoms crossing the reverse shock. For the first time we observe emission from the reverse shock surface well above and below the equatorial ring, suggesting a bipolar or conical structure perpendicular to the ring plane. Using the H-alpha imaging, we measure the mass flux of hydrogen atoms crossing the reverse shock front, in the velocity intervals (-7,500 < V(sub obs) < -2,800 km/s) and (1,000 < V(sub obs) < 7,500 km/s), ?M(sub H) = 1.2 × 10(exp -3) M/ y. We also present the first Lyman-alpha imaging of the whole remnant and new Chandra X-ray observations. Comparing the spatial distribution of the Lyman-alpha and X-ray emission, we observe that the majority of the high-velocity Lyman-alpha emission originates interior to the equatorial ring. The observed Lyman-alpha/H-alpha photon ratio, R(L-alpha/H-alpha) approx. = 17, is significantly higher than the theoretically predicted ratio of approx. = 5 for neutral atoms crossing the reverse shock front. We attribute this excess to Lyman-alpha emission produced by X-ray heating of the outer debris. The spatial orientation of the Lyman-alpha and X-ray emission suggests that X-ray heating of the outer debris is the dominant Lyman-alpha production mechanism in SN 1987A at this phase in its evolution.

  11. Ninth ISMAS workshop on mass spectrometry

    International Nuclear Information System (INIS)

    Aggarwal, S.K.

    2000-12-01

    Mass spectrometry has wide-ranging applications in such diverse areas as nuclear industry, agriculture, drugs, environment, petroleum and lentils. There is an urgent need to absorb and assimilate state-of-the-art technological developments in the field. Emerging trends in atomic mass spectrometry, advances in organic mass spectrometry, qualitative and quantitative analyses by mass spectrometry and mass spectrometry in oceanography are some of the areas that need to be expeditiously examined and are covered in this volume. Papers relevant to INIS are indexed separately

  12. Direct binding of syndecan-4 cytoplasmic domain to the catalytic domain of protein kinase C alpha (PKC alpha) increases focal adhesion localization of PKC alpha

    DEFF Research Database (Denmark)

    Lim, Ssang-Taek; Longley, Robert L; Couchman, John R

    2003-01-01

    alpha. Full-length PKC alpha weakly interacted with 4V by yeast two-hybrid assays, but PKC alpha constructs that lack the pseudosubstrate region or constructs of the whole catalytic domain interacted more strongly. A mutated 4V sequence (4V(YF): LGKKPIFKK) did not interact with PKC alpha, indicating...

  13. Increased virulence and competitive advantage of a/alpha over a/a or alpha/alpha offspring conserves the mating system of Candida albicans.

    Science.gov (United States)

    Lockhart, Shawn R; Wu, Wei; Radke, Joshua B; Zhao, Rui; Soll, David R

    2005-04-01

    The majority of Candida albicans strains in nature are a/alpha and must undergo homozygosis to a/a or alpha/alpha to mate. Here we have used a mouse model for systemic infection to test the hypothesis that a/alpha strains predominate in nature because they have a competitive advantage over a/a and alpha/alpha offspring in colonizing hosts. Single-strain injection experiments revealed that a/alpha strains were far more virulent than either their a/a or alpha/alpha offspring. When equal numbers of parent a/alpha and offspring a/a or alpha/alpha cells were co-injected, a/alpha always exhibited a competitive advantage at the time of extreme host morbidity or death. When equal numbers of an engineered a/a/alpha2 strain and its isogenic a/a parent strain were co-injected, the a/a/alpha2 strain exhibited a competitive advantage at the time of host morbidity or death, suggesting that the genotype of the mating-type (MTL) locus, not associated genes on chromosome 5, provides a competitive advantage. We therefore propose that heterozygosity at the MTL locus not only represses white-opaque switching and genes involved in the mating process, but also affects virulence, providing a competitive advantage to the a/alpha genotype that conserves the mating system of C. albicans in nature.

  14. Alpha intrusion on ovenight polysomnogram

    Directory of Open Access Journals (Sweden)

    Nahapetian R

    2014-06-01

    Full Text Available No abstract available. Article truncated after 150 words. A 30 year-old Army veteran with a past medical history significant for chronic lumbar back pain stemming from a fall-from-height injury sustained in 2006 was referred to the sleep laboratory for evaluation of chronic fatigue and excessive daytime hypersomnolence. His Epworth sleepiness scale score was 16. He denied a history of snoring and witnessed apnea. Body Mass Index (BMI was 25.7 kg/m2. His main sleep related complaints were frequent nocturnal arousals, poor sleep quality, un-refreshing sleep, prolonged latency to sleep onset, and nightmares. An In-lab attended diagnostic polysomnogram was performed. Sleep efficiency was reduced (73% and overall arousal index was not significantly elevated (3.2 events/hour. The sleep study showed rapid eye movement (REM related sleep disordered breathing that did not meet diagnostic criteria for sleep apnea. There was no evidence for period limb movement disorder. However, the study was significant for alpha wave intrusion in stage N2 non-REM and stage ...

  15. Diabetes and alpha lipoic acid

    Directory of Open Access Journals (Sweden)

    Issy eLaher

    2011-11-01

    Full Text Available Diabetes mellitus is a multi-faceted metabolic disorder where there is increased oxidative stress that contributes to the pathogenesis of this debilitating disease. This has prompted several investigations into the use of antioxidants as a complementary therapeutic approach. Alpha lipoic acid, a naturally occurring dithiol compound which plays an essential role in mitochondrial bioenergetic reactions, has gained considerable attention as an antioxidant for use in managing diabetic complications. Lipoic acid quenches reactive oxygen species, chelates metal ions, and reduces the oxidized forms of other antioxidants such as vitamin C, vitamin E and glutathione. It also boosts antioxidant defense system through Nrf2-mediated antioxidant gene expression and by modulation of peroxisome proliferator activated receptors-regulated genes. ALA inhibits nuclear factor kappa B and activates AMPK in skeletal muscles, which in turn have a plethora of metabolic consequences. These diverse actions suggest that a lipoic acid acts by multiple mechanisms, many of which have only been uncovered recently. In this review we briefly summarize the known biochemical properties of lipoic acid and then discussed the oxidative mechanisms implicated in diabetic complications and the mechanisms by which lipoic acid may ameliorate these reactions. The findings of some of the clinical trials in which lipoic acid administration has been tested in diabetic patients during the last 10 years are summarized. It appears that the clearest benefit of lipoic acid supplementation is in patients with diabetic neuropathy.

  16. Diagnostics for PLX-alpha

    Science.gov (United States)

    Gilmore, Mark; Hsu, Scott

    2015-11-01

    The goal of the Plasma Liner eXperiment PLX-alpha at Los Alamos National Laboratory is to establish the viability of creating a spherically imploding plasma liner for MIF and HED applications, using a spherical array of supersonic plasma jets launched by innovative contoured-gap coaxial plasma guns. PLX- α experiments will focus in particular on establishing the ram pressure and uniformity scalings of partial and fully spherical plasma liners. In order to characterize these parameters experimentally, a suite of diagnostics is planned, including multi-camera fast imaging, a 16-channel visible interferometer (upgraded from 8 channels) with reconfigurable, fiber-coupled front end, and visible and VUV high-resolution and survey spectroscopy. Tomographic reconstruction and data fusion techniques will be used in conjunction with interferometry, imaging, and synthetic diagnostics from modeling to characterize liner uniformity in 3D. Diagnostic and data analysis design, implementation, and status will be presented. Supported by the Advanced Research Projects Agency - Energy - U.S. Department of Energy.

  17. Effects of alpha particles on zebrafish embryos

    International Nuclear Information System (INIS)

    Yum, E.H.W.; Choi, V.W.Y.; Yu, K.N.; Li, V.W.T.; Cheng, S.H.

    2008-01-01

    Full text: Ionizing radiation such as X-ray and alpha particles can damage cellular macromolecules, which can lead to DNA single- and double-strand breaks. In the present work, we studied the effects of alpha particles on dechorionated zebrafish embryos. Thin polyallyldiglycol carbonate (PADC) films with a thickness of 16 μm were prepared from commercially available PADC films (with thickness of 100 μm) by chemical etching and used as support substrates for holding zebrafish embryos for alpha-particle irradiation. These films recorded alpha-particle hit positions, quantified the number and energy of alpha particles actually incident on the embryo cells, and thus enabled the calculation of the dose absorbed by the embryo cells. Irradiation was made at 1.25 hours post fertilization (hpf) with various absorbed dose. TdT-mediated dUTP Nick-End Labeling (TUNEL) assay was performed on the embryos at different time stages after irradiation. Marked apoptosis was detected only in embryos at earlier time stages. The results showed that DNA double-strand break during zebrafish embryogenesis can be induced by alpha-particle irradiation, which suggests that zebrafish is a potential model for assessing the effects of alpha-particle radiation

  18. Cortical Alpha Activity in Schizoaffective Patients

    Directory of Open Access Journals (Sweden)

    Mahdi Moeini

    2017-02-01

    Full Text Available Objective: Electrophysiological studies have identified abnormal oscillatory activities in the cerebral cortex in schizophrenia and mood disorders. Biological and pathophysiological evidence suggests specific deficits in serotonin (5-HT receptor function in schizoaffective disorder (SA, a clinical syndrome with characteristics of both schizophrenia and bipolar disorder. This study investigated alpha oscillations in patients with SA.Method: Electroencephalography was used to measure ongoing and evoked alpha oscillations in 38 adults meeting Diagnostic and Statistical Manual of Mental Disorders–Fourth Edition (DSM–IV criteria for SA, and in 39 healthy controls.Results: Spontaneous alpha power of the participants with SA was significantly lower than that of healthy participants [F (1, 75 = 8.81, P < 0.01]. Evoked alpha activity was also decreased in SA compared to controls [F (1, 75 = 5.67, P = 0.025].Conclusion: A strong reduction of alpha power in the posterior regions may reflect abnormality in the thalamocortical circuits. It is shown that hypoxia and reduced cerebral blood flow is associated with reduced alpha activity among different regions of the brain. Therefore, it can be concluded that greatly decreased alpha activity, particularly in centro-parietal and occipital regions, is related to SA symptoms such as hallucinations.

  19. Lucid dreaming and alpha activity: a preliminary report.

    Science.gov (United States)

    Ogilvie, R D; Hunt, H T; Tyson, P D; Lucescu, M L; Jeakins, D B

    1982-12-01

    10 good dream recallers spent 2 nights in the sleep lab during which they were awakened 4 times per night from REM sleep, twice during their highest alpha activity in REM, and twice during low REM alpha. 5 were given alpha feedback training prior to sleep onset. Arousals from high alpha REM sleep yielded significantly higher lucidity ratings. Alpha feedback had no effect upon lucidity or REM alpha levels. Similarities between lucid dreams and meditative phenomena are discussed.

  20. Analysis of essential oil of eaglewood tree (Aquilaria agallocha Roxb. by gas chromatography mass spectrometry

    Directory of Open Access Journals (Sweden)

    Mohammad Nazrul Islam Bhuiyan

    2009-06-01

    Full Text Available The study was carried out to find out the differences in composition of oils obtained from healthy, naturally infected and artificially screws wounds eaglewood (Aquilaria agallocha Roxb. using gas chromatography mass spectrometry (GC-MS analysis. Natural healthy plants agar contained octacosane (19.83%, naphthalene, 1,2,3,5,6,7,8,8a-octahydro-1,8a-dimethyl-7-(1-methylethenyl-, [1R-(1.alpha.,7.beta.,8a.alpha.]- (12.67%, 5-isobutyramido-2-methyl pyrimidine (13.52%, caryophyllene oxide (11.25% and (.+-.-cadinene (5.46%. Natural infected plants agar (super agar contained cycloheptane, 4-methylene-1-methyl-2-(2-methyl-1-propen-1-yl-1-vinyl- (46.17%, caryophyllene oxide (33.00% and 7-Isopropenyl-4a-methyl-1-methylenedecahydronaphthalene (20.83%. Artificially screw injected plants agar contained diisooctyl phthalate (71.97%, 1H-Cycloprop[e]azulen-4-ol, decahydro-1,1,4,7-tetramethyl-, [1ar-(1a.alpha.,4.beta.,4a.beta., 7.alpha., 7a.beta., 7b.alpha.]- (9.16%, hexadecanoic acid (7.05%, naphthalene, 1,2,3,5,6,7,8,8a-octahydro-1,8a-dimethyl-7-(1-methylethenyl-, [1R-(1.alpha.,7.beta.,8a.alpha.]- (6.45% and aristolene (5.36%. This study showed a marked difference in the oil compositions among the treatments with regards to their quality.

  1. Analysis of essential oil of eaglewood tree (Aquilaria agallocha Roxb. by gas chromatography mass spectrometry

    Directory of Open Access Journals (Sweden)

    Mohammad Nazrul Islam Bhuiyan

    2009-03-01

    Full Text Available The study was carried out to find out the differences in composition of oils obtained from healthy, naturally infected and artificially screws wounds eaglewood (Aquilaria agallocha Roxb. using gas chromatography mass spectrometry (GC-MS analysis. Natural healthy plants agar contained octacosane (19.83%, naphthalene, 1,2,3,5,6,7,8,8a-octahydro-1,8a-dimethyl-7-(1-methylethenyl-, [1R-(1.alpha.,7.beta.,8a.alpha.]- (12.67%, 5-isobutyramido-2-methyl pyrimidine (13.52%, caryophyllene oxide (11.25% and (.+-.-cadinene (5.46%. Natural infected plants agar (super agar contained cycloheptane, 4-methylene-1-methyl-2-(2-methyl-1-propen-1-yl-1-vinyl- (46.17%, caryophyllene oxide (33.00% and 7-Isopropenyl-4a-methyl-1-methylenedecahydronaphthalene (20.83%. Artificially screw injected plants agar contained diisooctyl phthalate (71.97%, 1H-Cycloprop[e]azulen-4-ol, decahydro-1,1,4,7-tetramethyl-, [1ar-(1a.alpha.,4.beta.,4a.beta., 7.alpha., 7a.beta., 7b.alpha.]- (9.16%, hexadecanoic acid (7.05%, naphthalene, 1,2,3,5,6,7,8,8a-octahydro-1,8a-dimethyl-7-(1-methylethenyl-, [1R-(1.alpha.,7.beta.,8a.alpha.]- (6.45% and aristolene (5.36%. This study showed a marked difference in the oil compositions among the treatments with regards to their quality.

  2. Automatic gamma spectrometry analytical apparatus

    International Nuclear Information System (INIS)

    Lamargot, J.-P.; Wanin, Maurice.

    1980-01-01

    This invention falls within the area of quantitative or semi-quantitative analysis by gamma spectrometry and particularly refers to a device for bringing the samples into the counting position. The purpose of this invention is precisely to provide an automatic apparatus specifically adapted to the analysis of hard gamma radiations. To this effect, the invention relates to a gamma spectrometry analytical device comprising a lead containment, a detector of which the sensitive part is located inside the containment and additionally comprising a transfer system for bringing the analyzed samples in succession to a counting position inside the containment above the detector. A feed compartment enables the samples to be brought in turn one by one on to the transfer system through a duct connecting the compartment to the transfer system. Sequential systems for the coordinated forward feed of the samples in the compartment and the transfer system complete this device [fr

  3. EMERGING POLLUTANTS, MASS SPECTROMETRY, AND ...

    Science.gov (United States)

    Historically fundamental to amassing our understanding of environmental processes and chemical pollution is the realm of mass spectrometry (MS) - the mainstay of analytical chemistry - the workhorse that supplies definitive data that environmental scientists and engineers reply upon for identifying molecular compositions (and ultimately structures) of chemicals. While the power of MS has long been visible to the practicing environmental chemist, it borders on obscurity to the lay public and many scientists. While MS has played a long, historic (and largely invisible) role in establishing our knowledge of environmental processes and pollution, what recognition it does enjoy is usually relegated to that of a tool. It is usually the relevance or significance of the knowledge acquired from the application of the tool that has ultimate meaning to the public and science at large - not how the data were acquired. Methods (736/800): Mass Spectrometry and the

  4. Imaging Mass Spectrometry in Neuroscience

    Science.gov (United States)

    2013-01-01

    Imaging mass spectrometry is an emerging technique of great potential for investigating the chemical architecture in biological matrices. Although the potential for studying neurobiological systems is evident, the relevance of the technique for application in neuroscience is still in its infancy. In the present Review, a principal overview of the different approaches, including matrix assisted laser desorption ionization and secondary ion mass spectrometry, is provided with particular focus on their strengths and limitations for studying different neurochemical species in situ and in vitro. The potential of the various approaches is discussed based on both fundamental and biomedical neuroscience research. This Review aims to serve as a general guide to familiarize the neuroscience community and other biomedical researchers with the technique, highlighting its great potential and suitability for comprehensive and specific chemical imaging. PMID:23530951

  5. Measurement of ²²⁶Ra in soil from oil field: advantages of γ-ray spectrometry and application to the IAEA-448 CRM.

    Science.gov (United States)

    Ceccatelli, A; Katona, R; Kis-Benedek, G; Pitois, A

    2014-05-01

    The analytical performance of gamma-ray spectrometry for the measurement of (226)Ra in TENORM (Technically Enhanced Naturally Occurring Radioactive Material) soil was investigated by the IAEA. Fast results were obtained for characterization and certification of a new TENORM Certified Reference Material (CRM), identified as IAEA-448 (soil from oil field). The combined standard uncertainty of the gamma-ray spectrometry results is of the order of 2-3% for massic activity measurement values ranging from 16500 Bq kg(-1) to 21500 Bq kg(-1). Methodologies used for the production and certification of the IAEA-448 CRM are presented. Analytical results were confirmed by alpha spectrometry. The "t" test showed agreement between alpha and gamma results at 95% confidence level. © 2013 Published by Elsevier Ltd.

  6. Anomalous atomic volume of alpha-Pu

    DEFF Research Database (Denmark)

    Kollar, J.; Vitos, Levente; Skriver, Hans Lomholt

    1997-01-01

    We have performed full charge-density calculations for the equilibrium atomic volumes of the alpha-phase light actinide metals using the local density approximation (LDA) and the generalized gradient approximation (GGA). The average deviation between the experimental and the GGA atomic radii is 1.......3%. The comparison between the LDA and GGA results show that the anomalously large atomic volume of alpha-Pu relative to alpha-Np can be ascribed to exchange-correlation effects connected with the presence of low coordinated sites in the structure where the f electrons are close to the onset of localization...

  7. Alpha spectral analysis via artificial neural networks

    International Nuclear Information System (INIS)

    Kangas, L.J.; Hashem, S.; Keller, P.E.; Kouzes, R.T.; Troyer, G.L.

    1994-10-01

    An artificial neural network system that assigns quality factors to alpha particle energy spectra is discussed. The alpha energy spectra are used to detect plutonium contamination in the work environment. The quality factors represent the levels of spectral degradation caused by miscalibration and foreign matter affecting the instruments. A set of spectra was labeled with a quality factor by an expert and used in training the artificial neural network expert system. The investigation shows that the expert knowledge of alpha spectra quality factors can be transferred to an ANN system

  8. Production of alpha 1-proteinase inhibitor (human).

    Science.gov (United States)

    Hein, R H; Van Beveren, S M; Shearer, M A; Coan, M H; Brockway, W J

    1990-03-01

    A method for large scale isolation of alpha 1-proteinase inhibitor (alpha 1-PI) is described. This method employs waste Cohn Fraction IV-1 as the starting material and involves fractional precipitation with polyethylene glycol followed by ion exchange chromatography on diethylaminoethanol (DEAE)-Sepharose. The process also incorporates a ten hour, at 60 degrees C, heat-treatment step to reduce or eliminate the risk of transmission of viral disease. The final product, having a purity of approximately 60%, is freeze-dried. This preparation behaves almost identically to the alpha 1-PI in plasma and is suitable for replacement therapy in hereditary emphysema.

  9. Measurements of $\\alpha_s$ in $pp$ Collisions at the LHC

    CERN Document Server

    Warburton, Andreas; The ATLAS collaboration

    2015-01-01

    The coupling of the strong force, $\\alpha_s$, is deemed to be a fundamental parameter of Nature, and, beyond the quark masses, constitutes the only free parameter in the QCD Lagrangian. Provided is an overview of CERN Large Hadron Collider (LHC) measurements of $\\alpha_s(M_Z)$ evaluated at the $Z$-boson mass and of the running of $\\alpha_s(Q)$ as a function of energy-momentum transfer $Q$. The measurements were performed by the ATLAS and CMS Collaborations using proton-proton ($pp$) collisions with centre-of-mass energies of 7 TeV and data samples with time-integrated luminosities of up to 5 fb$^{-1}$. Four different categories of observable were used in the described extractions of $\\alpha_s$: inclusive jet cross sections, 3-jet to 2-jet inclusive cross-section ratios, 3-jet mass cross sections, and top-quark pair production cross sections. These results, which include the first NNLO measurement of $\\alpha_s$ at a hadron collider and the first determinations of $\\alpha_s$ at energy scales above 1 TeV, are co...

  10. Mass Spectrometry Applications for Toxicology

    OpenAIRE

    Mbughuni, Michael M.; Jannetto, Paul J.; Langman, Loralie J.

    2016-01-01

    Toxicology is a multidisciplinary study of poisons, aimed to correlate the quantitative and qualitative relationships between poisons and their physiological and behavioural effects in living systems. Other key aspects of toxicology focus on elucidation of the mechanisms of action of poisons and development of remedies and treatment plans for associated toxic effects. In these endeavours, Mass spectrometry (MS) has become a powerful analytical technique with a wide range of application used i...

  11. A Quantitative Electrochemiluminescence Assay for Clostridium perfringens alpha toxin

    National Research Council Canada - National Science Library

    Merrill, Gerald A; Rivera, Victor R; Neal, Dwayne D; Young, Charles; Poli, Mark A

    2006-01-01

    .... Biotinylated antibodies to C. perfringens alpha toxin bound to streptavidin paramagnetic beads specifically immunoadsorbed soluble sample alpha toxin which subsequently selectively immunoadsorbed ruthenium (Ru...

  12. Autoxidation versus biotransformation of alpha-pinene to flavors with Pleurotus sapidus: regioselective hydroperoxidation of alpha-pinene and stereoselective dehydrogenation of verbenol.

    Science.gov (United States)

    Krings, Ulrich; Lehnert, Nicole; Fraatz, Marco A; Hardebusch, Björn; Zorn, Holger; Berger, Ralf G

    2009-11-11

    The enzymatic conversion of alpha-pinene to verbenols, verbenone, and minor volatile flavors was studied using submerged cultured cells, lyophilisate, and microsomal fractions of the edible basidiomycete Pleurotus sapidus . The similarity of the product range obtained by the bioconversions with the range of products found after autoxidation of alpha-pinene at 100 degrees C suggested similar initial pinene radicals. Extracts of the bioconversions were analyzed using thin layer chromatography with hydroperoxide staining and cool on-column capillary gas chromatography-mass spectrometry. Two isomer alpha-pinene hydroperoxides were identified as the key intermediates and their structures confirmed by comparison with synthesized reference samples and by microchemical reduction to (Z)- and (E)-verbenol. When the biocatalysts were supplemented with one of the verbenols, only the (Z)-isomer was oxidized, indicating the activity of a highly stereospecific monoterpenol dehydrogenase. The structural comparison of subunits shows that fungal oxifunctionalization reactions of some common terpene substrates, such as (+)-limonene or (+)-valencene, might likewise be catalyzed by dioxygenases rather than by CYP450 enzymes, as previously assumed.

  13. Instrumentation for mass spectrometry: 1997

    Energy Technology Data Exchange (ETDEWEB)

    McLuckey, S.A.

    1997-08-01

    All mass spectrometry experiments involve the manipulation of material, an interface with the mass spectrometer, ionization, ion manipulation/analysis, detection and data collection/reduction. Each of these elements involve instrumentation. The wide range of species now amenable to mass spectrometry and the diverse areas of physical science in which it plays a role have led to a seemingly unlimited array of instrumental combinations. However, only a limited number of mass analyzers, and their combinations, dominate. The dominant analyzers include time-of-flight, Fourier transform ion cyclotron resonance, the Paul trap, the mass filter, and the sector mass spectrometer. Why there are so few (or so many, depending upon one`s point of view) can be understood upon consideration of a set of mass analyzer figures of merit. These include mass resolution, mass accuracy, mass range, dynamic range, abundance sensitivity, precision, efficiency, speed, MS{sup n} capability, compatibility with the ionizer, cost, and size. The most appropriate form of mass spectrometry is determined by the priorities of the particular measurement placed on the various mass analyzer characteristics and the relative strengths of the analyzers in meeting the requirements. Each of the analyzer types has a unique set of figures of merit that makes it optimally suited for particular applications. This paper discusses these figures of merit, provides data illustrating recent developments for each analyzer type, and gives the figures of merit of each type of analyzer as they stand in 1997. 101 refs., 24 figs.

  14. Neutron-induced alpha radiography

    International Nuclear Information System (INIS)

    Pereira, Marco Antonio Stanojev

    2008-01-01

    A new radiography technique to inspect thin samples was developed. Low energy alpha particles, generated by a boron based screen under thermal neutron irradiation, are used as penetrating radiation. The solid state nuclear track detector CR-39 has been used to register the image. The interaction of the α - particles with the CR-39 gives rise to damages which under an adequate chemical etching became tracks the basic units forming the image. A digital system was developed for data acquisition and data analysis as well as for image processing. The irradiation and etching conditions to obtain the best radiography are 1,3 hours and 25 minutes at 70 deg C respectively. For such conditions samples having 10 μm in thickness can be inspected with a spatial resolution of 32 μm. The use of the digital system has reduced the time spent for data acquisition and data analysis and has improved the radiography image visualization. Furthermore, by using the digital system, it was possible to study several new parameters regarding the tracks which are very important to understand and study the image formation theory in solid state nuclear track detectors, the one used in this thesis. Some radiography images are also shown which demonstrate the potential of the proposed radiography technique. When compared with the other radiography techniques already in use to inspect thin samples, the present one developed in the present paper allows a smaller time to obtain the image, it is not necessary to handle liquid radioactive substances, the detector is insensitive to β, γ, X-ray and visible light. (author)

  15. Urban gamma spectrometry. Report 2

    International Nuclear Information System (INIS)

    Aage, H.K.; Kuukankorpi, S.; Moring, M.; Smolander, P.; Toivonen, H.

    2009-06-01

    Urban gamma spectrometry has been given only minor attention with the focus being on rural gamma spectrometry. However, in recent years the Nordic emergency management authorities have turned focus towards border control and lost or stolen sources. Gamma spectra measured in urban areas are characterized by a wide variety of spectrum shapes and very fast changes in environmental background. In 2004 a Danish CGS (Carborne Gamma Spectrometry) survey took place in Copenhagen. It was found that gamma spectrometry in urban areas is far more complicated to interpret than had previously been thought and a new method 'Fitting with Spectral Components', FSC, based on NASVD, was tested with some success. In Finland, a database 'LINSSI' has been developed for spectral data management. In CGS search mode a 'peak hypothesis test' is applied to the measured spectra. This system was tested during the Helsinki 2005 Athletics World Championship and it provides fast and reliable automated alarms for intermediate and high level signals. In Sweden mobile detector systems are used for border controls and problems are encountered when making measurement in harbour, container areas. The methods for handling data and for interpretation of urban gamma spectrometry measurements were compared and tested on the same data sets from Copenhagen and Helsinki. Software tools were developed for converting data between the Finnish LINSSI database and the binary file formats used in Denmark and Sweden. The Processing methods used at DTU and STUK have different goals. The ASSS and FSC methods are designed to optimize the overall detection capability of the system, while sacrificing speed, usability and to a certain level robustness. These methods cannot always be used for real time analysis. The Peak Significance method is designed to give robust alarms in real time, while sacrificing some of the detection capability. Thus these methods are not interchangeable, but rather complementary. An ideal system

  16. Urban gamma spectrometry. Report 2

    Energy Technology Data Exchange (ETDEWEB)

    Aage, H.K. (Technical Univ. of Denmark, Kgs. Lyngby (Denmark)); Kuukankorpi, S.; Moring, M.; Smolander, P.; Toivonen, H. (Radiation and Nuclear Safety Authority, Helsinki (Finland))

    2009-06-15

    Urban gamma spectrometry has been given only minor attention with the focus being on rural gamma spectrometry. However, in recent years the Nordic emergency management authorities have turned focus towards border control and lost or stolen sources. Gamma spectra measured in urban areas are characterized by a wide variety of spectrum shapes and very fast changes in environmental background. In 2004 a Danish CGS (Carborne Gamma Spectrometry) survey took place in Copenhagen. It was found that gamma spectrometry in urban areas is far more complicated to interpret than had previously been thought and a new method 'Fitting with Spectral Components', FSC, based on NASVD, was tested with some success. In Finland, a database 'LINSSI' has been developed for spectral data management. In CGS search mode a 'peak hypothesis test' is applied to the measured spectra. This system was tested during the Helsinki 2005 Athletics World Championship and it provides fast and reliable automated alarms for intermediate and high level signals. In Sweden mobile detector systems are used for border controls and problems are encountered when making measurement in harbour, container areas. The methods for handling data and for interpretation of urban gamma spectrometry measurements were compared and tested on the same data sets from Copenhagen and Helsinki. Software tools were developed for converting data between the Finnish LINSSI database and the binary file formats used in Denmark and Sweden. The Processing methods used at DTU and STUK have different goals. The ASSS and FSC methods are designed to optimize the overall detection capability of the system, while sacrificing speed, usability and to a certain level robustness. These methods cannot always be used for real time analysis. The Peak Significance method is designed to give robust alarms in real time, while sacrificing some of the detection capability. Thus these methods are not interchangeable, but rather

  17. NEW APPROACHES TO CONFINED ALPHA DIAGNOSTICS

    Energy Technology Data Exchange (ETDEWEB)

    FISHER,R.K

    2004-04-01

    Three new approaches to obtain information on the confined fast alphas in International Thermonuclear Experimental Reactor (ITER) are proposed. The first technique measures the energetic charge exchange (CX) neutrals that result from the alpha collision-induced knock-on fuel ion tails undergoing electron capture on the MeV D neutral beams planned for heating and current drive. The second technique measures the energetic knock-on neutron tail due to alphas using the lengths of the proton recoil tracks produced by neutron collisions in nuclear emulsions. The range of the 14 to 20 MeV recoil protons increases by {approx}140 microns per MeV. The third approach would measure the CX helium neutrals resulting from confined alphas capturing two electrons in the ablation cloud surrounding a dense gas jet that has been proposed for disruption mitigation in ITER.

  18. NEW APPROACHES TO CONFINED ALPHA DIAGNOSTICS

    International Nuclear Information System (INIS)

    FISHER, R.K.

    2004-01-01

    Three new approaches to obtain information on the confined fast alphas in International Thermonuclear Experimental Reactor (ITER) are proposed. The first technique measures the energetic charge exchange (CX) neutrals that result from the alpha collision-induced knock-on fuel ion tails undergoing electron capture on the MeV D neutral beams planned for heating and current drive. The second technique measures the energetic knock-on neutron tail due to alphas using the lengths of the proton recoil tracks produced by neutron collisions in nuclear emulsions. The range of the 14 to 20 MeV recoil protons increases by ∼140 microns per MeV. The third approach would measure the CX helium neutrals resulting from confined alphas capturing two electrons in the ablation cloud surrounding a dense gas jet that has been proposed for disruption mitigation in ITER

  19. Strichartz estimates on $alpha$-modulation spaces

    Directory of Open Access Journals (Sweden)

    Weichao Guo

    2013-05-01

    Full Text Available In this article, we consider some dispersive equations, including Schrodinger equations, nonelliptic Schrodinger equations, and wave equations. We develop some Strichartz estimates in the frame of alpha-modulation spaces.

  20. Targeted alpha therapy: Applications and current status

    Energy Technology Data Exchange (ETDEWEB)

    Bruchertseifer, Frank, E-mail: frank.bruchertseifer@ec.europa.eu [European Commission, Joint Research Centre, Karlsruhe (Germany)

    2017-07-01

    Full text: The field of targeted alpha therapy has been developed rapidly in the last decade. Besides {sup 223}Ra, {sup 211}At and {sup 212}Pb/{sup 212}Bi the alpha emitters {sup 225}Ac and {sup 213}Bi are promising therapeutic radionuclides for application in targeted alpha therapy of cancer and infectious diseases. The presentation will give a short overview about the current clinical treatments with alpha emitting radionuclides and will place an emphasis on the most promising clinical testing of peptides and antibodies labelled with {sup 225}Ac and {sup 213}Bi for treatment of metastatic castration-resistant prostate cancer patients with glioma and glioblastoma multiform, PSMA-positive tumor phenotype and bladder carcinoma in situ. (author)

  1. Calibration of alpha surface contamination monitor

    International Nuclear Information System (INIS)

    Freitas, I.S.M. de; Goncalez, O.L.

    1990-01-01

    In this work, the results, as well as the methodology, of the calibration of an alpha surface contamination monitor are presented. The calibration factors are obtained by least-squares fitting with effective variance. (author)

  2. Solar Imagery - Chromosphere - H-Alpha

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Collection includes a variety of H-alpha photographic datasets contributed by a number of national and private solar observatories located worldwide. Solar...

  3. Energy dependence of event shapes and of $\\alpha_s$ at LEP 2

    CERN Document Server

    Abreu, P; Adye, T; Adzic, P; Albrecht, Z; Alderweireld, T; Alekseev, G D; Alemany, R; Allmendinger, T; Allport, P P; Almehed, S; Amaldi, Ugo; Amapane, N; Amato, S; Anassontzis, E G; Andersson, P; Andreazza, A; Andringa, S; Antilogus, P; Apel, W D; Arnoud, Y; Åsman, B; Augustin, J E; Augustinus, A; Baillon, Paul; Bambade, P; Barão, F; Barbiellini, Guido; Barbier, R; Bardin, Dimitri Yuri; Barker, G; Baroncelli, A; Battaglia, Marco; Baubillier, M; Becks, K H; Begalli, M; Behrmann, A; Beillière, P; Belokopytov, Yu A; Belous, K S; Benekos, N C; Benvenuti, Alberto C; Bérat, C; Berggren, M; Bertini, D; Bertrand, D; Besançon, M; Bianchi, F; Bigi, M; Bilenky, S M; Bizouard, M A; Bloch, D; Blom, H M; Bonesini, M; Bonivento, W; Boonekamp, M; Booth, P S L; Borgland, A W; Borisov, G; Bosio, C; Botner, O; Boudinov, E; Bouquet, B; Bourdarios, C; Bowcock, T J V; Boyko, I; Bozovic, I; Bozzo, M; Branchini, P; Brenke, T; Brenner, R A; Brückman, P; Brunet, J M; Bugge, L; Buran, T; Burgsmüller, T; Buschbeck, Brigitte; Buschmann, P; Cabrera, S; Caccia, M; Calvi, M; Camporesi, T; Canale, V; Carena, F; Carroll, L; Caso, Carlo; Castillo-Gimenez, M V; Cattai, A; Cavallo, F R; Chabaud, V; Chapkin, M M; Charpentier, P; Chaussard, L; Checchia, P; Chelkov, G A; Chierici, R; Chliapnikov, P V; Chochula, P; Chorowicz, V; Chudoba, J; Cieslik, K; Collins, P; Contri, R; Cortina, E; Cosme, G; Cossutti, F; Cowell, J H; Crawley, H B; Crennell, D J; Crépé, S; Crosetti, G; Cuevas-Maestro, J; Czellar, S; Davenport, Martyn; Da Silva, W; Deghorain, A; Della Ricca, G; Delpierre, P A; Demaria, N; De Angelis, A; de Boer, Wim; De Clercq, C; De Lotto, B; De Min, A; De Paula, L S; Dijkstra, H; Di Ciaccio, Lucia; Dolbeau, J; Doroba, K; Dracos, M; Drees, J; Dris, M; Duperrin, A; Durand, J D; Eigen, G; Ekelöf, T J C; Ekspong, Gösta; Ellert, M; Elsing, M; Engel, J P; Erzen, B; Espirito-Santo, M C; Falk, E; Fanourakis, G K; Fassouliotis, D; Fayot, J; Feindt, Michael; Fenyuk, A; Ferrari, P; Ferrer, A; Ferrer-Ribas, E; Ferro, F; Fichet, S; Firestone, A; Flagmeyer, U; Föth, H; Fokitis, E; Fontanelli, F; Franek, B J; Frodesen, A G; Frühwirth, R; Fulda-Quenzer, F; Fuster, J A; Galloni, A; Gamba, D; Gamblin, S; Gandelman, M; García, C; Gaspar, C; Gaspar, M; Gasparini, U; Gavillet, P; Gazis, E N; Gelé, D; Ghodbane, N; Gil, I; Glege, F; Gokieli, R; Golob, B; Gómez-Ceballos, G; Gonçalves, P; González-Caballero, I; Gopal, Gian P; Gorn, L; Górski, M; Guz, Yu; Gracco, Valerio; Grahl, J; Graziani, E; Green, C; Grimm, H J; Gris, P; Grosdidier, G; Grzelak, K; Günther, M; Guy, J; Hahn, F; Hahn, S; Haider, S; Hallgren, A; Hamacher, K; Hansen, J; Harris, F J; Hedberg, V; Heising, S; Hernández, J J; Herquet, P; Herr, H; Hessing, T L; Heuser, J M; Higón, E; Holmgren, S O; Holt, P J; Hoorelbeke, S; Houlden, M A; Hrubec, Josef; Huet, K; Hughes, G J; Hultqvist, K; Jackson, J N; Jacobsson, R; Jalocha, P; Janik, R; Jarlskog, C; Jarlskog, G; Jarry, P; Jean-Marie, B; Johansson, E K; Jönsson, P E; Joram, C; Juillot, P; Kapusta, F; Karafasoulis, K; Katsanevas, S; Katsoufis, E C; Keränen, R; Kersevan, Borut P; Khomenko, B A; Khovanskii, N N; Kiiskinen, A P; King, B J; Kinvig, A; Kjaer, N J; Klapp, O; Klein, H; Kluit, P M; Kokkinias, P; Koratzinos, M; Kostyukhin, V; Kourkoumelis, C; Kuznetsov, O; Krammer, Manfred; Kriznic, E; Krstic, J; Krumshtein, Z; Kubinec, P; Kurowska, J; Kurvinen, K L; Lamsa, J; Lane, D W; Langefeld, P; Lapin, V; Laugier, J P; Lauhakangas, R; Leder, Gerhard; Ledroit, F; Lefébure, V; Leinonen, L; Leisos, A; Leitner, R; Lemonne, J; Lenzen, Georg; Lepeltier, V; Lesiak, T; Lethuillier, M; Libby, J; Liko, D; Lipniacka, A; Lippi, I; Lörstad, B; Loken, J G; Lopes, J H; López, J M; López-Fernandez, R; Loukas, D; Lutz, P; Lyons, L; MacNaughton, J N; Mahon, J R; Maio, A; Malek, A; Malmgren, T G M; Maltezos, S; Malychev, V; Mandl, F; Marco, J; Marco, R P; Maréchal, B; Margoni, M; Marin, J C; Mariotti, C; Markou, A; Martínez-Rivero, C; Martínez-Vidal, F; Martí i García, S; Mastroyiannopoulos, N; Matorras, F; Matteuzzi, C; Matthiae, Giorgio; Masik, J; Mazzucato, F; Mazzucato, M; McCubbin, M L; McKay, R; McNulty, R; McPherson, G; Meroni, C; Meyer, W T; Migliore, E; Mirabito, L; Mitaroff, Winfried A; Mjörnmark, U; Moa, T; Moch, M; Møller, R; Mönig, K; Monge, M R; Moreau, X; Morettini, P; Morton, G A; Müller, U; Münich, K; Mulders, M; Mulet-Marquis, C; Muresan, R; Murray, W J; Muryn, B; Myatt, Gerald; Myklebust, T; Naraghi, F; Nassiakou, M; Navarria, Francesco Luigi; Navas, S; Nawrocki, K; Negri, P; Némécek, S; Neufeld, N; Neumeister, N; Nicolaidou, R; Nielsen, B S; Nikolenko, M; Nomokonov, V P; Normand, Ainsley; Nygren, A; Obraztsov, V F; Olshevskii, A G; Onofre, A; Orava, Risto; Orazi, G; Österberg, K; Ouraou, A; Paganoni, M; Paiano, S; Pain, R; Paiva, R; Palacios, J; Palka, H; Papadopoulou, T D; Papageorgiou, K; Pape, L; Parkes, C; Parodi, F; Parzefall, U; Passeri, A; Passon, O; Pegoraro, M; Peralta, L; Pernicka, Manfred; Perrotta, A; Petridou, C; Petrolini, A; Phillips, H T; Pierre, F; Pimenta, M; Piotto, E; Podobnik, T; Pol, M E; Polok, G; Poropat, P; Pozdnyakov, V; Privitera, P; Pukhaeva, N; Pullia, Antonio; Radojicic, D; Ragazzi, S; Rahmani, H; Ratoff, P N; Read, A L; Rebecchi, P; Redaelli, N G; Regler, Meinhard; Reid, D; Reinhardt, R; Renton, P B; Resvanis, L K; Richard, F; Rídky, J; Rinaudo, G; Røhne, O M; Romero, A; Ronchese, P; Rosenberg, E I; Rosinsky, P; Roudeau, Patrick; Rovelli, T; Royon, C; Ruhlmann-Kleider, V; Ruiz, A; Saarikko, H; Sacquin, Yu; Sadovskii, A; Sajot, G; Salt, J; Sampsonidis, D; Sannino, M; Schneider, H; Schwemling, P; Schwering, B; Schwickerath, U; Schyns, M A E; Scuri, F; Seager, P; Sedykh, Yu; Segar, A M; Sekulin, R L; Shellard, R C; Sheridan, A; Siebel, M; Simard, L C; Simonetto, F; Sissakian, A N; Smadja, G; Smirnov, N; Smirnova, O G; Smith, G R; Sopczak, André; Sosnowski, R; Spassoff, Tz; Spiriti, E; Sponholz, P; Squarcia, S; Stanescu, C; Stanic, S; Stevenson, K; Stocchi, A; Strub, R; Stugu, B; Szczekowski, M; Szeptycka, M; Tabarelli de Fatis, T; Tegenfeldt, F; Terranova, F; Thomas, J; Timmermans, J; Tinti, N; Tkatchev, L G; Todorova-Nová, S; Tomaradze, A G; Tomé, B; Tonazzo, A; Tortora, L; Tranströmer, G; Treille, D; Tristram, G; Trochimczuk, M; Troncon, C; Tsirou, A L; Turluer, M L; Tyapkin, I A; Tzamarias, S; Ullaland, O; Uvarov, V; Valenti, G; Vallazza, E; Van der Velde, C; van Apeldoorn, G W; van Dam, P; Van Doninck, W K; Van Eldik, J; Van Lysebetten, A; Van Vulpen, I B; Vassilopoulos, N; Vegni, G; Ventura, L; Venus, W A; Verbeure, F; Verlato, M; Vertogradov, L S; Verzi, V; Vilanova, D; Vitale, L; Vlasov, E; Vodopyanov, A S; Vollmer, C F; Voulgaris, G; Vrba, V; Wahlen, H; Walck, C; Weiser, C; Wicke, D; Wickens, J H; Wilkinson, G R; Winter, M; Witek, M; Wolf, G; Yi, J; Yushchenko, O P; Zaitsev, A; Zalewska-Bak, A; Zalewski, Piotr; Zavrtanik, D; Zevgolatakos, E; Zimin, N I; Zucchelli, G C; Zumerle, G

    1999-01-01

    Infrared and collinear safe event shape distributions and their mean values are determined using the data taken at ve di erent centre of mass energies above $M_Z$ with the DELPHI detector at LEP. From the event shapes, the strong coupling $\\alpha_s$ is extracted in $O(\\alpha^2_s)$, NLLA and a combined scheme using hadronisation corrections evaluated with fragmentation model generators as well as using an analytical power ansatz. Comparing these measurements to those obtained at MZ, the energy dependence (running) of $\\alpha_s$ is accessible. The logarithmic energy slope of the inverse strong coupling is measured to be $d\\alpha_{s}^{-1}/d log(E_{cm}) = 1.39 \\pm 0.34(stat) \\pm 0.17(syst)$, in good agreement with the QCD expectation of 1.27.

  4. Influence of fast alpha diffusion and thermal alpha buildup on tokamak reactor performance

    International Nuclear Information System (INIS)

    Uckan, N.A.; Tolliver, J.S.; Houlberg, W.A.; Attenberger, S.E.

    1988-01-01

    The effect of fast alpha diffusion and thermal alpha accumulation on the confinement capability of a candidate Engineering Test Reactor plasma (Tokamak Ignition/Burn Experimental Reactor) in achieving ignition and steady-state driven operation has been assessed using both global and 1-1/2-dimensional transport models. Estimates are made of the threshold for radial diffusion of fast alphas and thermal alpha buildup. It is shown that a relatively low level of radial transport, when combined with large gradients in the fast alpha density, leads to a significant radial flow with a deleterious effect on plasma performance. Similarly, modest levels of thermal alpha concentration significantly influence the ignition and steady-state burn capability

  5. Measurement of the angle alpha at BABAR

    Energy Technology Data Exchange (ETDEWEB)

    Perez, A.; /Orsay, LAL

    2009-06-25

    The authors present recent measurements of the CKM angle {alpha} using data collected by the BABAR detector at the PEP-II asymmetric-energy e{sup +}e{sup -} collider at the SLAC National Accelerator Laboratory, operating at the {Upsilon}(4S) resonance. They present constraints on {alpha} from B {yields} {pi}{pi}, B {yields} {rho}{rho} and B {yields} {rho}{pi} decays.

  6. Conceptual design report for alpha waste incinerator

    International Nuclear Information System (INIS)

    1979-04-01

    The Alpha Waste Incinerator, a new facility in the SRP H-Area, will process transuranic or alpha-contaminated combustible solid wastes. It will seal the radioactive ash and scrubbing salt residues in cans for interim storage in drums on site burial ground pads. This report includes objectives, project estimate, schedule, standards and criteria, excluded costs, safety evaluation, energy consumption, environmental assessment, and key drawings

  7. Beteigeuze (Alpha Orionis) und Mintaka (Delta Orionis)

    Science.gov (United States)

    Vollmann, Wolfgang

    2013-02-01

    Magnitude measures transformed to Johnson V of Alpha Orionis (Betelgeuse) and Delta Orionis with a wide-angle lens and DSLR are presented and discussed. Alpha Orionis light changes are shown clearly. The primary and secondary eclipses of Delta Orionis with amplitudes of 0.12 and 0.05 mag respectively are clearly recorded. They occur near phase 0.00 and 0.50 respectively of current elements from VSX (2).

  8. Considering the determination of an alpha value

    International Nuclear Information System (INIS)

    Lorenz, B.

    1987-01-01

    Following an outline of the most important international methods of evaluating an alpha value (the monetary equivalent of one man-sievert) and an approach deemed suitable for use in the GDR, it is recommended that alpha be taken as 30,000 Mark per man-sievert in national cost-benefit analyses. This value should be revisited every five to ten years. (author)

  9. Alpha-root Processes for Derivatives pricing

    OpenAIRE

    Balakrishna, BS

    2010-01-01

    A class of mean reverting positive stochastic processes driven by alpha-stable distributions, referred to here as alpha-root processes in analogy to the square root process (Cox-Ingersoll-Ross process), is a subclass of affine processes, in particular continuous state branching processes with immigration (CBI processes). Being affine, they provide semi-analytical results for the implied term structures as well as for the characteristic exponents for their associated distributions. Their use h...

  10. Self-assembling, dynamic alphaPNAs

    DEFF Research Database (Denmark)

    Nielsen, Peter E

    2009-01-01

    In the recent report published in Science, Ghadiri and coworkers describe dynamic tPNAs, alphaPNA derivatives with a nucleobase attached via a thioester bond that are a step forward toward self-repairing and replicating molecules.......In the recent report published in Science, Ghadiri and coworkers describe dynamic tPNAs, alphaPNA derivatives with a nucleobase attached via a thioester bond that are a step forward toward self-repairing and replicating molecules....

  11. Alpha-emitters for medical therapy workshop

    International Nuclear Information System (INIS)

    Feinendegen, L.E.; McClure, J.J.

    1996-01-01

    A workshop on ''Alpha-Emitters for Medical Therapy'' was held May 30-31, 1996 in Denver Colorado to identify research goals and potential clinical needs for applying alpha-particle emitters and to provide DOE with sufficient information for future planning. The workshop was attended by 36 participants representing radiooncology, nuclear medicine, immunotherapy, radiobiology, molecular biology, biochemistry, radiopharmaceutical chemistry, dosimetry, and physics. This report provides a summary of the key points and recommendations arrived at during the conference

  12. Cytokine vaccination: neutralising IL-1alpha autoantibodies induced by immunisation with homologous IL-1alpha

    DEFF Research Database (Denmark)

    Svenson, M; Hansen, M B; Thomsen, Allan Randrup

    2000-01-01

    High-affinity IgG autoantibodies (aAb) to IL-1alpha are among the most frequently found aAb to cytokines in humans. To establish an animal model with aAb to IL-1alpha, we immunised mice with recombinant murine IL-1alpha. Unprimed and Bacille Calmette-Guérin (BCG)-primed BALB/cA mice were vaccinat...

  13. Structures of G [alpha [superscript i1

    Energy Technology Data Exchange (ETDEWEB)

    Johnston, Christopher A.; Willard, Francis S.; Jezyk, Mark R.; Fredericks, Zoey; Bodor, Erik T.; Jones, Miller B.; Blaesius, Rainer; Watts, Val J.; Harden, T. Kendall; Sondek, John; Ramer, J. Kevin; Siderovski, David P. (Karo Bio); (UNC); (Purdue)

    2010-07-19

    Heterotrimeric G proteins are molecular switches that regulate numerous signaling pathways involved in cellular physiology. This characteristic is achieved by the adoption of two principal states: an inactive, GDP bound state and an active, GTP bound state. Under basal conditions, G proteins exist in the inactive, GDP bound state; thus, nucleotide exchange is crucial to the onset of signaling. Despite our understanding of G protein signaling pathways, the mechanism of nucleotide exchange remains elusive. We employed phage display technology to identify nucleotide state-dependent G{alpha} binding peptides. Herein, we report a GDP-selective G{alpha} binding peptide, KB-752, that enhances spontaneous nucleotide exchange of G{alpha}{sub i} subunits. Structural determination of the G{alpha}{sub i1}/peptide complex reveals unique changes in the G{alpha} switch regions predicted to enhance nucleotide exchange by creating a GDP dissociation route. Our results cast light onto a potential mechanism by which G{alpha} subunits adopt a conformation suitable for nucleotide exchange.

  14. Current status and perspectives in alpha radioimmunotherapy.

    Science.gov (United States)

    Chérel, M; Davodeau, F; Kraeber-Bodéré, F; Chatal, J F

    2006-12-01

    Systemic administration of radiolabeled antibody directed against tumor antigens in radioimmunotherapy (RIT) enables to specifically target the cancer cells and to destroy them. So far, this strategy has proven its efficiency in the treatment of some hematological cancers with antibodies labeled with beta emitting radionuclides. In the last 2 decades, availability of short half life alpha emitters prompted to consider their use in RIT. Contrary to beta particles, alpha particles have a short path length and display a high lineic energy transfer. Those physical characteristics open new fields of clinical applications complementary to beta-RIT. To date, alpha-RIT is still at a preclinical stage of development: the radiolabeling methods need to be optimized to ensure in vivo stability of the radiopharmaceuticals. Some radionuclides have complex decay schemes with daughters emitting further alpha particles whose toxicity needs to be investigated. The modalities of administration of radiolabeled antibodies in animal models require also to be improved for delivering higher doses to tumor targets. A comprehensive analysis of the specific events occurring at cell or tissue level in response to alpha irradiation would be of great interest in order to define the best therapeutic association for residual disease or consolidation treatments. This approach has been proven to be efficient in increasing antitumor response either by using high doses with organ protection (kidney, bone marrow) or by a synergistic effect between alpha-RIT and associated treatments, such as chemotherapy.

  15. Systemic Targeted Alpha Radiotherapy for Cancer

    Directory of Open Access Journals (Sweden)

    Allan B. J.

    2013-09-01

    Full Text Available Background: The fundamental principles of internal targeted alpha therapy for cancer were established many decades ago.The high linear energy transfer (LET of alpha radiation to the targeted cancer cellscauses double strand breaks in DNA. At the same time, the short range radiation spares adjacent normal tissues. This targeted approach complements conventional external beam radiotherapy and chemotherapy. Such therapies fail on several fronts, such as lack of control of some primary cancers (e.g.glioblastoma multiformeand to inhibit the development of lethal metastatic cancer after successful treatment of the primary cancer. Objective: This review charts the developing role of systemic high LET, internal radiation therapy. Method: Targeted alpha therapy is a rapidly advancing experimental therapy that holds promise to deliver high cytotoxicity to targeted cancer cells. Initially thought to be indicated for leukemia and micrometastases, there is now evidence that solid tumors can also be regressed. Results: Alpha therapy may be molecular or physiological in its targeting. Alpha emitting radioisotopes such as Bi-212, Bi-213, At-211 and Ac-225 are used to label monoclonal antibodies or proteins that target specifc cancer cells. Alternatively, Radium-233 is used for palliative therapy of breast and prostate cancers because of its bone seeking properties. Conclusion: Preclinical studies and clinical trials of alpha therapy are discussed for leukemia, lymphoma, melanoma, glioblastoma multiforme, bone metastases, ovarian cancer, pancreatic cancer and other cancers.

  16. Cytokine vaccination: neutralising IL-1alpha autoantibodies induced by immunisation with homologous IL-1alpha

    DEFF Research Database (Denmark)

    Svenson, M; Hansen, M B; Thomsen, Allan Randrup

    2000-01-01

    High-affinity IgG autoantibodies (aAb) to IL-1alpha are among the most frequently found aAb to cytokines in humans. To establish an animal model with aAb to IL-1alpha, we immunised mice with recombinant murine IL-1alpha. Unprimed and Bacille Calmette-Guérin (BCG)-primed BALB/cA mice were vaccinated...... in mice by vaccination with recombinant murine IL-1alpha conjugated to PPD. Studies of the effects of IL-1alpha aAb in such animals may help clarify the importance of naturally occurring IL-1alpha aAb in humans and permit the evaluation of future therapies with cytokine aAb in patients...... with IL-1alpha coupled to purified protein derivative of tuberculin (PPD). Both unprimed and primed animals developed IgG aAb to IL-1alpha. These aAb persisted at high levels more than 100 days after vaccination and did not cross-react with murine IL-1beta. The induced anti-IL-1alpha aAb inhibited binding...

  17. Alpha 1-blockers vs 5 alpha-reductase inhibitors in benign prostatic hyperplasia. A comparative review

    DEFF Research Database (Denmark)

    Andersen, J T

    1995-01-01

    During recent years, pharmacological treatment of symptomatic benign prostatic hyperplasia (BPH) has become the primary treatment choice for an increasing number of patients. The 2 principal drug classes employed are alpha 1-blockers and 5 alpha-reductase inhibitors. Current information from...... of patients who will respond well to alpha 1-blockers have yet to be identified, and data concerning the long term effects of these drugs are not yet available. 5 alpha-Reductase inhibitors have a slow onset of effect, but treatment leads to improvement in symptoms, reduction of the size of the prostate gland...... or unwilling to undergo surgical resection of the prostate will benefit from such therapy....

  18. Project and construction of a spectrometer for alpha particles using surface barrier detectors

    International Nuclear Information System (INIS)

    Terini, R.A.

    1986-01-01

    The project, construction, tests and some applications of a system for alpha and beta spectrometry, using surface barrier detector are described. The device includes a solid state detector ORTEC-Series F coupled to a system for amplifying the charges produced by passage of an ionizing particle through the detector. The amplifying system is composed by a charge sensitive pre-amplifier, which employs an operational amplifier CA 3140, and a low noise linear amplifier, which is based on the operational amplifiers CA 3140 and LM 301. The pre-amplifier stage input impedance is on the order of TΩ and produces output pulses which heights are proportional to total charge produced by passage of particle through the detector sensitive volume. The main advantage to use charge sensitive system lies in obtention of independent pulse heights of the distributed capacity of connecting cable between the detector and the pre-amplifier. The total system amplification ca reach a maximum of 50.000 in the linear region. Pulses are analysed in a multichannel system ORTEC, model 6240. The amplifier system is easily constructed and low cost using components available in the national market, and it can be employed with ionization chambers, proportional counters, scitillation counters and semiconductor detectors. The results of spectrometer application for alpha spectrometry of AM 241 source were compared to systems made with imported stages. (Author) [pt

  19. Bulk GaN alpha-particle detector with large depletion region and improved energy resolution

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Qiang; Mulligan, Padhraic [Nuclear Engineering Program, Department of Mechanical and Aerospace Engineering, The Ohio State University, Columbus, OH 43210 (United States); Wang, Jinghui [Department of Radiology, Stanford University, 1201 Welch Rd, Stanford, CA 94305 (United States); Chuirazzi, William [Nuclear Engineering Program, Department of Mechanical and Aerospace Engineering, The Ohio State University, Columbus, OH 43210 (United States); Cao, Lei, E-mail: cao.152@osu.edu [Nuclear Engineering Program, Department of Mechanical and Aerospace Engineering, The Ohio State University, Columbus, OH 43210 (United States)

    2017-03-21

    An alpha-particle detector was fabricated using a freestanding n-type bulk GaN wafer with a Au/Ni/GaN sandwich Schottky structure. Current–voltage measurements at room temperature revealed a Schottky contact with a leakage current of 7.53±0.3 nA at a reverse bias of 200 V. The detector had a large depletion depth that can capture much of the energy from 5.486 MeV alpha particles emitted from a {sup 241}Am source. The resolution of its alpha-particle energy spectrum was improved to 2.2±0.2% at 5.486 MeV under a bias of 550 V. This superior resolution was attributed to the shortening of the carrier transit time and the large energy deposition within the large depletion depth, i.e., 27 µm at −550 V, which all resulted in a more complete charge collection. A model developed using the ATLAS simulation framework from Silvaco Inc. was employed to study the charge collection process. The simulation results were found to agree closely with the experimental results. This detector will be beneficial for research at neutron scattering facilities, the International Thermonuclear Experimental Reactor, and the Large Hadron Collider, among other institutions, where the Si-based charged particle detectors could be quickly degraded in an intense radiation field. - Highlights: • An alpha-particle detector based on a Schottky-structured GaN wafer was tested. • The detector's large depletion depth enables fuller energy spectra to be obtained. • The best resolution yet attained in GaN alpha-particle spectrometry was achieved. • The detector's short carrier transit time resulted in improved charge collection. • This detector is usable in extreme conditions, including intense radiation fields.

  20. Selectivity of the imidazoline alpha-adrenoceptor agonists (oxymetazoline and cirazoline) for human cloned alpha 1-adrenoceptor subtypes.

    Science.gov (United States)

    Horie, K.; Obika, K.; Foglar, R.; Tsujimoto, G.

    1995-01-01

    1. To investigate the structure-activity relationships of alpha-adrenoceptor agonists for the alpha 1-adrenoceptor subtypes, we have compared the imidazoline class of compounds, oxymetazoline and cirazoline, with the phenethylamine, noradrenaline, in their affinities and also in their intrinsic activities in Chinese hamster ovary (CHO) cells stably expressing the cloned human alpha 1-adrenoceptor subtypes (alpha 1a-, alpha 1b-, and alpha 1d-subtypes). 2. Radioligand binding studies with [125I]-HEAT showed that cirazoline and oxymetazoline had higher affinities at alpha 1a-subtype than at alpha 1b- and alpha 1d-subtypes, while noradrenaline had higher affinity at the alpha 1d-subtype than at alpha 1a- and alpha 1b-subtypes. 3. In functional studies, cirazoline caused transients of cytosolic Ca2+ concentrations ([Ca2+]i response) in a concentration-dependent manner and developed a maximal response similar to that to noradrenaline in CHO cells expressing the alpha 1a-subtype, while it acted as a partial agonist at alpha 1b- and alpha 1d-adrenoceptors. Oxymetazoline, on the other hand, was a weak agonist at alpha 1a-adrenoceptors, and has no intrinsic activity at the other subtypes. 4. Using the phenoxybenzamine inactivation method, the relationships between receptor occupancy and noradrenaline-induced [Ca2+]i response for alpha 1a- and alpha 1d-subtypes were found to be linear, whereas it was moderately hyperbolic for the alpha 1b-subtype, indicating the absence of receptor reserves in CHO cells expressing alpha 1a- and alpha 1d-subtypes while there exists a small receptor reserve for CHO cells expressing the alpha 1b-subtype.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:8564227

  1. Structure-activity relationships of 2alpha-substituted androstenedione analogs as aromatase inhibitors and their aromatization reactions.

    Science.gov (United States)

    Numazawa, Mitsuteru; Handa, Wakako; Hasegawa, Chie; Takahashi, Madoka

    2005-12-01

    Aromatase catalyzes the conversion of androstenedione (1a, AD) to estrone through three sequential oxygenations of the 19-methyl group. To gain insight into the spatial nature of the AD binding (active) site of aromatase in relation to the catalytic function of the enzyme, we tested for the ability of 2alpha-substituted (halogeno, alkyl, hydroxy, and alkoxy) ADs (1b-1i) to inhibit aromatase in human placental microsomes as well as their ability to serve as a substrate for the enzyme. All of the steroids inhibited the enzyme in a competitive manner with the apparent K(i)'s ranging from 45 to 1150 nM. 2alpha-Halogeno (F, Cl, and Br) and 2alpha-alkyl (CH3 and CH2CH3) steroids 1b-1f were powerful to good inhibitors (Ki=45-171 nM) whereas steroids 1g-1i, having an oxygen function (hydroxy or alkoxy) at C-2alpha, were poor inhibitors (Ki=670-1150 nM). Aromatization of some of the steroids with placental microsomes was analyzed by gas chromatography-mass spectrometry, indicating that the aromatization rate of the bromide 1d was about two-fold that of the natural substrate AD and that of 2alpha-methoxide 1h was similar to that of AD. Kinetic analysis of the aromatization of androgens revealed that a good substrate was not essentially a good inhibitor for aromatase.

  2. Tumor necrosis factor alpha promotes the expression of immunosuppressive proteins and enhances the cell growth in a human bone marrow-derived stem cell culture

    Energy Technology Data Exchange (ETDEWEB)

    Miettinen, Johanna A., E-mail: johanna.miettinen@oulu.fi [Institute of Clinical Medicine, Department of Internal Medicine, University of Oulu, P.O. Box 5000, FIN-90014 Oulu (Finland); Pietilae, Mika [Institute of Biomedicine, Department of Anatomy and Cell Biology, University of Oulu, P.O. Box 5000, FIN-90014 Oulu (Finland); Salonen, Riikka J. [Institute of Clinical Medicine, Department of Internal Medicine, University of Oulu, P.O. Box 5000, FIN-90014 Oulu (Finland); Institute of Biomedicine, Department of Anatomy and Cell Biology, University of Oulu, P.O. Box 5000, FIN-90014 Oulu (Finland); Ohlmeier, Steffen [Proteomics Core Facility, Biocenter Oulu, Department of Biochemistry, University of Oulu, P.O. Box 3000, FIN-90014 Oulu (Finland); Ylitalo, Kari; Huikuri, Heikki V. [Institute of Clinical Medicine, Department of Internal Medicine, University of Oulu, P.O. Box 5000, FIN-90014 Oulu (Finland); Lehenkari, Petri [Institute of Biomedicine, Department of Anatomy and Cell Biology, University of Oulu, P.O. Box 5000, FIN-90014 Oulu (Finland)

    2011-04-01

    Mesenchymal stem cells (MSCs) are widely used in experimental treatments for various conditions that involve normal tissue regeneration via inflammatory repair. It is known that MSCs can secrete multiple soluble factors and suppress inflammation. Even though the effect of MSCs on inflammation has been extensively studied, the effect of inflammation on MSCs is poorly understood. One of the major cytokines released at the site of inflammation is tumor necrosis factor alpha (TNF-{alpha}) which is known to induce MSC invasion and proliferation. Therefore, we wanted to test the effects of TNF-{alpha} exposure on MSCs derived from human bone marrow. We found, as expected, that cell proliferation was significantly enhanced during TNF-{alpha} exposure. However, according to the cell surface marker analysis, the intensity of several antigens in the minimum criteria panel for MSCs proposed by International Society of Cellular Therapy (ISCT) was decreased dramatically, and in certain cases, the criteria for MSCs were not fulfilled. In addition, TNF-{alpha} exposure resulted in a significant but transient increase in human leukocyte antigen and CD54 expression. Additional proteomic analysis by two-dimensional difference gel electrophoresis and mass spectrometry revealed three proteins whose expression levels decreased and 8 proteins whose expression levels increased significantly during TNF-{alpha} exposure. The majority of these proteins could be linked to immunosuppressive and signalling pathways. These results strongly support reactive and immunosuppressive activation of MSCs during TNF-{alpha} exposure, which might influence MSC differentiation stage and capacity.

  3. Anti-IL-1alpha autoantibodies in early rheumatoid arthritis

    DEFF Research Database (Denmark)

    Forslind, K; Svensson, Birte; Svenson, M

    2001-01-01

    To investigate the potential predictive value of autoantibodies against IL1-alpha (anti-IL-1alpha) in patients with early rheumatoid arthritis (RA).......To investigate the potential predictive value of autoantibodies against IL1-alpha (anti-IL-1alpha) in patients with early rheumatoid arthritis (RA)....

  4. The nitric oxide-donating pravastatin derivative, NCX 6550 [(1S-[1alpha(betaS*, deltaS*), 2alpha, 6alpha, 8beta-(R*), 8a alpha

    Science.gov (United States)

    Dever, G; Spickett, C M; Kennedy, S; Rush, C; Tennant, G; Monopoli, A; Wainwright, C L

    2007-01-01

    Statins possess anti-inflammatory effects that may contribute to their ability to slow atherogenesis, whereas nitric oxide (NO) also influences inflammatory cell adhesion. This study aimed to determine whether a novel NO-donating pravastatin derivative, NCX 6550 [(1S-[1alpha(betaS*,deltaS*),2alpha,6alpha,8beta-(R*),8a alpha

  5. Deuterium measurement by emission spectrometry

    International Nuclear Information System (INIS)

    Niemann, E.G.; Heilig, K.; Dumke, I.

    1978-01-01

    The method makes it possible to determine the relative deuterium content of enriched water samples. For this, the relative intensities of the Hα and Dα lines are measured which are emitted by a high-frequency discharge in water vapour. Although the method is not as exact as mass spectrometry, it has the following advantages: - Easy sample preparation (no reduction necessary); - samples of highly different enrichment can be measured one after the other without the danger of memory effects; - much lower apparatus and cost expenditure. The necessary sample size is about the same in both methods. (orig.) [de

  6. Principle of accelerator mass spectrometry

    International Nuclear Information System (INIS)

    Matsuzaki, Hiroyuki

    2007-01-01

    The principle of accelerator mass spectrometry (AMS) is described mainly on technical aspects: hardware construction of AMS, measurement of isotope ratio, sensitivity of measurement (measuring limit), measuring accuracy, and application of data. The content may be summarized as follows: rare isotope (often long-lived radioactive isotope) can be detected by various use of the ion energy obtained by the acceleration of ions, a measurable isotope ratio is one of rare isotope to abundant isotopes, and a measured value of isotope ratio is uncertainty to true one. Such a fact must be kept in mind on the use of AMS data to application research. (M.H.)

  7. Role of Mass Spectrometry in Clinical Endocrinology.

    Science.gov (United States)

    Ketha, Siva S; Singh, Ravinder J; Ketha, Hemamalini

    2017-09-01

    The advent of mass spectrometry into the clinical laboratory has led to an improvement in clinical management of several endocrine diseases. Liquid chromatography tandem mass spectrometry found some of its first clinical applications in the diagnosis of inborn errors of metabolism, in quantitative steroid analysis, and in drug analysis laboratories. Mass spectrometry assays offer analytical sensitivity and specificity that is superior to immunoassays for many analytes. This article highlights several areas of clinical endocrinology that have witnessed the use of liquid chromatography tandem mass spectrometry to improve clinical outcomes. Copyright © 2017 Elsevier Inc. All rights reserved.

  8. Alpha-particle fluence in radiobiological experiments.

    Science.gov (United States)

    Nikezic, Dragoslav; Yu, Kwan Ngok

    2017-03-01

    Two methods were proposed for determining alpha-particle fluence for radiobiological experiments. The first involved calculating the probabilities of hitting the target for alpha particles emitted from a source through Monte Carlo simulations, which when multiplied by the activity of the source gave the fluence at the target. The second relied on the number of chemically etched alpha-particle tracks developed on a solid-state nuclear track detector (SSNTD) that was irradiated by an alpha-particle source. The etching efficiencies (defined as percentages of latent tracks created by alpha particles from the source that could develop to become visible tracks upon chemical etching) were computed through Monte Carlo simulations, which when multiplied by the experimentally counted number of visible tracks would also give the fluence at the target. We studied alpha particles with an energy of 5.486 MeV emitted from an 241Am source, and considered the alpha-particle tracks developed on polyallyldiglycol carbonate film, which is a common SSNTD. Our results showed that the etching efficiencies were equal to one for source-film distances of from 0.6 to 3.5 cm for a circular film of radius of 1 cm, and for source-film distances of from 1 to 3 cm for circular film of radius of 2 cm. For circular film with a radius of 3 cm, the etching efficiencies never reached 1. On the other hand, the hit probability decreased monotonically with increase in the source-target distance, and fell to zero when the source-target distance was larger than the particle range in air. © The Author 2016. Published by Oxford University Press on behalf of The Japan Radiation Research Society and Japanese Society for Radiation Oncology.

  9. Cancer radioimmunotherapy with alpha-emitting nuclides

    Energy Technology Data Exchange (ETDEWEB)

    Couturier, Olivier [INSERM U 601, Nantes (France); Place Alexis Ricordeau, Department of Nuclear Medicine, Nantes, Cedex (France); Supiot, Stephane; Degraef-Mougin, Marie; Faivre-Chauvet, Alain; Carlier, Thomas; Chatal, Jean-Francois; Davodeau, Francois; Cherel, Michel [INSERM U 601, Nantes (France)

    2005-04-01

    In lymphoid malignancies and in certain solid cancers such as medullary thyroid carcinoma, somewhat mixed success has been achieved when applying radioimmunotherapy (RIT) with {beta}-emitters for the treatment of refractory cases. The development of novel RIT with {alpha}-emitters has created new opportunities and theoretical advantages due to the high linear energy transfer (LET) and the short path length in biological tissue of {alpha}-particles. These physical properties offer the prospect of achieving selective tumoural cell killing. Thus, RIT with {alpha}-emitters appears particularly suited for the elimination of circulating single cells or cell clusters or for the treatment of micrometastases at an early stage. However, to avoid non-specific irradiation of healthy tissues, it is necessary to identify accessible tumoural targets easily and rapidly. For this purpose, a small number of {alpha}-emitters have been investigated, among which only a few have been used for in vivo preclinical studies. Another problem is the availability and cost of these radionuclides; for instance, the low cost and the development of a reliable actinium-225/bismuth-213 generator were probably determining elements in the choice of bismuth-213 in the only human trial of RIT with an {alpha}-emitter. This article reviews the literature concerning monoclonal antibodies radiolabelled with {alpha}-emitters that have been developed for possible RIT in cancer patients. The principal radio-immunoconjugates are considered, starting with physical and chemical properties of {alpha}-emitters, their mode of production, the possibilities and difficulties of labelling, in vitro studies and finally, when available, in vivo preclinical and clinical studies. (orig.)

  10. Cancer radioimmunotherapy with alpha-emitting nuclides.

    Science.gov (United States)

    Couturier, Olivier; Supiot, Stéphane; Degraef-Mougin, Marie; Faivre-Chauvet, Alain; Carlier, Thomas; Chatal, Jean-François; Davodeau, François; Cherel, Michel

    2005-05-01

    In lymphoid malignancies and in certain solid cancers such as medullary thyroid carcinoma, somewhat mixed success has been achieved when applying radioimmunotherapy (RIT) with beta-emitters for the treatment of refractory cases. The development of novel RIT with alpha-emitters has created new opportunities and theoretical advantages due to the high linear energy transfer (LET) and the short path length in biological tissue of alpha-particles. These physical properties offer the prospect of achieving selective tumoural cell killing. Thus, RIT with alpha-emitters appears particularly suited for the elimination of circulating single cells or cell clusters or for the treatment of micrometastases at an early stage. However, to avoid non-specific irradiation of healthy tissues, it is necessary to identify accessible tumoural targets easily and rapidly. For this purpose, a small number of alpha-emitters have been investigated, among which only a few have been used for in vivo preclinical studies. Another problem is the availability and cost of these radionuclides; for instance, the low cost and the development of a reliable actinium-225/bismuth-213 generator were probably determining elements in the choice of bismuth-213 in the only human trial of RIT with an alpha-emitter. This article reviews the literature concerning monoclonal antibodies radiolabelled with alpha-emitters that have been developed for possible RIT in cancer patients. The principal radio-immunoconjugates are considered, starting with physical and chemical properties of alpha-emitters, their mode of production, the possibilities and difficulties of labelling, in vitro studies and finally, when available, in vivo preclinical and clinical studies.

  11. Pharmacologic specificity of alpha-2 adrenergic receptor subtypes

    Energy Technology Data Exchange (ETDEWEB)

    Petrash, A.; Bylund, D.

    1986-03-01

    The authors have defined alpha-2 adrenergic receptor subtypes in human and rat tissues using prazosin as a subtype selective drug. Prazosin has a lower affinity (250 nM) at alpha-2A receptor and a higher affinity (5 nM) at alpha-2B receptors. In order to determine if other adrenergic drugs are selective for one or the other subtypes, the authors performed (/sup 3/H)yohimbine inhibition experiments with various adrenergic drugs in tissues containing alpha-2A, alpha-2B or both subtypes. Oxymetazoline, WB4101 and yohimbine were found to be 80-, 20- and 10-fold more potent at alpha-2A receptors than at alpha-2B receptors. Phentolamine, adazoxan, (+)- and (-)-mianserin, clonidine, (+)-butaclamol, (-)- and (+)-norepinephrine, epinephrine, dopamine and thioridazine were found to have equal affinities for the two subtypes. These results further validate the subdivision of alpha-2 adrenergic receptors into alpha-2A and alpha-2B subtypes.

  12. Validation of Am-241 measurement in ion chamber type smoke detector by using gamma spectrometry system

    International Nuclear Information System (INIS)

    Yii Mei Wo; Khairul Nizam Razali

    2005-01-01

    Smoke detectors are useful devices in modern days that able to save many lives. Even though, the use of ion chamber type smoke detector (usually contain Americium-241) was exempted in Malaysia, but the trading of this device was controlled by regulation, under the Atomic Energy Licensing Act (Act 304). The activity of the Am-241 can be measured by using the Gamma Spectrometry System since it was much easier, compared to Alpha Spectrometry System. To do so, the system was first need to be calibrated using the standard reference source to find the efficiency of the germanium detector. The method used for the measurement was first validated for several relevant parameters, which include specificity, precision (repeatability), bias (accuracy), linearity, working range, detection limit, robustness and ruggedness to ensure it was fit for the purpose. The measured Am-241 activity inside the smoke detector will be reported together with a reasonable expanded uncertainty arise from the measurement. (Author)

  13. Protective effects of plasma alpha-tocopherols on the risk of inorganic arsenic-related urothelial carcinoma

    Energy Technology Data Exchange (ETDEWEB)

    Chung, Chi-Jung [School of Public Health, College of Public Health and Nutrition, Taipei Medical University, Taipei, Taiwan (China); Pu, Yeong-Shiau [Department of Urology, National Taiwan University Hospital, Taipei, Taiwan (China); Chen, Ying-Ting [Department of Public Health, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan (China); Su, Chien-Tien [Department of Family Medicine, Taipei Medical University Hospital, Taipei, Taiwan (China); Wu, Chia-Chang [School of Public Health, College of Public Health and Nutrition, Taipei Medical University, Taipei, Taiwan (China); Department of Urology, Taipei Medical Universtiy-Shuang Ho Hospital, Taipei, Taiwan (China); Shiue, Horng-Sheng [Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Taoyuan, Taiwan (China); Huang, Chao-Yuan [Department of Urology, National Taiwan University Hospital, Taipei, Taiwan (China); Graduate Institute of Clinical Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan (China); Hsueh, Yu-Mei, E-mail: ymhsueh@tmu.edu.tw [Department of Public Health, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan (China)

    2011-02-15

    Arsenic plays an important role in producing oxidative stress in cultured cells. To investigate the interaction between high oxidative stress and low arsenic methylation capacity on arsenic carcinogenesis, a case-control study was conducted to evaluate the relationship among the indices of oxidative stress, such as urinary 8-hydroxydeoxyquanine (8-OHdG), as well as plasma micronutrients and urinary arsenic profiles on urothelial carcinoma (UC) risk. Urinary 8-OHdG was measured using high-sensitivity enzyme-linked immunosorbent assay kits. The urinary arsenic species were analyzed using high-performance liquid chromatography and hydride generator-atomic absorption spectrometry. Plasma micronutrient levels were analyzed using reversed-phase high-performance liquid chromatography. The present study showed a significant protective effect of plasma alpha-tocopherol on UC risk. Plasma alpha-tocopherol levels were significantly inversely related to urinary total arsenic concentrations and inorganic arsenic percentage (InAs%), and significantly positively related to dimethylarsinic acid percentage (DMA%). There were no correlations between plasma micronutrients and urinary 8-OHdG. Study participants with lower alpha-tocopherol and higher urinary total arsenic, higher InAs%, higher MMA%, and lower DMA% had a higher UC risk than those with higher alpha-tocopherol and lower urinary total arsenic, lower InAs%, lower MMA%, and higher DMA%. These results suggest that plasma alpha-tocopherol might modify the risk of inorganic arsenic-related UC. - Research Highlights: {yields} Plasma alpha-tocopherol levels were significantly inversely related to UC risk. {yields} There were no correlations between plasma micronutrients and urinary 8-OHdG. {yields} People with lower alpha-tocopherol and higher total arsenic had increased UC risk.

  14. Alpha 1 B- but not alpha 1 A-adrenoceptors mediate inositol phosphate generation

    NARCIS (Netherlands)

    Michel, M. C.; Hanft, G.; Gross, G.

    1990-01-01

    We used novel highly subtype-selective antagonists to study whether alpha 1A- and/or alpha 1B-adrenoceptors mediate the stimulation of inositol phosphate generation by noradrenaline in rat cerebral cortex. Phentolamine (10 microM) and prazosin (100 nM) completely abolished the stimulated inositol

  15. Role of macrophage inflammatory protein-1 alpha (MIP-1 alpha) in acute lung injury in rats

    DEFF Research Database (Denmark)

    Shanley, T P; Schmal, H; Friedl, H P

    1995-01-01

    The role of macrophage inflammatory protein-1 alpha (MIP-1 alpha) in the pathogenesis of acute lung injury in rats after intrapulmonary deposition of IgG immune complexes or intratracheal administration of LPS has been assessed. Critical to these studies was the cloning and functional expression...

  16. Alpha-in-air monitor for continuous monitoring based on alpha to beta ratio

    International Nuclear Information System (INIS)

    Somayaji, K.S.; Venkataramani, R.; Swaminathan, N.; Pushparaja

    1997-01-01

    Measurement of long-lived alpha activity collected on a filter paper in continuous air monitoring of ambient working environment is difficult due to interference from much larger concentrations of short-lived alpha emitting daughter products of 222 Rn and 220 Rn. However, the ratio between the natural alpha and beta activity is approximately constant and this constancy of the ratio is used to discriminate against short-lived natural radioactivity in continuous air monitoring. Detection system was specially designed for the purpose of simultaneous counting of alpha and beta activity deposited on the filter paper during continuous monitoring. The activity ratios were calculated and plotted against the monitoring duration up to about six hours. Monitoring was carried out in three facilities with different ventilation conditions. Presence of any long-lived alpha contamination on the filter paper results in increase in the alpha to beta ratio. Long-lived 239 Pu contamination of about 16 DAC.h could be detected after about 45 minutes of commencement of the sampling. The experimental results using prototype units have shown that the approach of using alpha to beta activity ratio method to detect long-lived alpha activity in the presence of short-lived natural activity is satisfactory. (author)

  17. PLE CATALYZED HYDROLYZES OF ALPHA-SUBSTITUTED ALPHA-HYDROXY ESTERS - THE INFLUENCE OF THE SUBSTITUENTS

    NARCIS (Netherlands)

    MOORLAG, H; KELLOGG, RM

    1991-01-01

    The enzymatic hydrolyses of a variety of alpha-substituted mandelic and lactic esters using pig liver esterase (PLE) have been investigated. High to moderate enantioselectivity was found for various alpha-substituted mandelic esters, whereas PLE showed low to no enantioselectivity for

  18. Increased voluntary exercise in mice deficient for tumour necrosis factor-alpha and lymphotoxin-alpha.

    NARCIS (Netherlands)

    Netea, M.G.; Kullberg, B.J.; Vonk, A.G.; Verschueren, I.; Joosten, L.A.B.; Meer, J.W.M. van der

    2007-01-01

    BACKGROUND: The endogenous mediators playing a role in the sensing of fatigue and cessation of exercise are yet to be characterized. We hypothesized that proinflammatory cytokines, in particular tumour necrosis factor-alpha (TNFalpha) and lymphotoxin-alpha (LT) transmit signals leading to fatigue.

  19. Alpha-particle elastic scattering on [sup 16]O in the four [alpha]-particle model

    Energy Technology Data Exchange (ETDEWEB)

    Li Qingrun (CCAST (World Lab.), Beijing (China) Inst. of High Energy Physics, Academia Sinica, Beijing (China)); Yang Yongxu (Dept. of Physics, Guangxi Normal Univ., Guilin (China))

    1993-08-23

    A folding potential describing the alpha-particle scattering on [sup 16]O is constructed based on the four [alpha]-particle model of the nucleus [sup 16]O. This folding potential provides a good description of the experimental data covering a broad energy range. (orig.)

  20. Consistent Measurements of $\\alpha_{s}$ from Precise Oriented Event Shape Distributions

    CERN Document Server

    Abreu, P.; Adye, T.; Adzic, P.; Albrecht, Z.; Alderweireld, T.; Alekseev, G.D.; Alemany, R.; Allmendinger, T.; Allport, P.P.; Almehed, S.; Amaldi, U.; Amapane, N.; Amato, S.; Anassontzis, E.G.; Andersson, P.; Andreazza, A.; Andringa, S.; Antilogus, P.; Apel, W.D.; Arnoud, Y.; Asman, B.; Augustin, J.E.; Augustinus, A.; Baillon, P.; Bambade, P.; Barao, F.; Barbiellini, G.; Barbier, R.; Bardin, D.Yu.; Barker, G.J.; Baroncelli, A.; Battaglia, M.; Baubillier, M.; Becks, K.H.; Begalli, M.; Behrmann, A.; Beilliere, P.; Belokopytov, Yu.; Benekos, N.C.; Benvenuti, A.C.; Berat, C.; Berggren, M.; Bertini, D.; Bertrand, D.; Besancon, M.; Bigi, M.; Bilenky, Mikhail S.; Bizouard, M.A.; Bloch, D.; Blom, H.M.; Bonesini, M.; Bonivento, W.; Boonekamp, M.; Booth, P.S.L.; Borgland, A.W.; Borisov, G.; Bosio, C.; Botner, O.; Boudinov, E.; Bouquet, B.; Bourdarios, C.; Bowcock, T.J.V.; Boyko, I.; Bozovic, I.; Bozzo, M.; Branchini, P.; Brenke, T.; Brenner, R.A.; Bruckman, P.; Brunet, J.M.; Bugge, L.; Buran, T.; Burgsmuller, T.; Buschbeck, B.; Buschmann, P.; Cabrera, S.; Caccia, M.; Calvi, M.; Camporesi, T.; Canale, V.; Carena, F.; Carroll, L.; Caso, C.; Castillo Gimenez, M.V.; Cattai, A.; Cavallo, F.R.; Chabaud, V.; Charpentier, P.; Chaussard, L.; Checchia, P.; Chelkov, G.A.; Chierici, R.; Chochula, P.; Chorowicz, V.; Chudoba, J.; Cieslik, K.; Collins, P.; Contri, R.; Cortina, E.; Cosme, G.; Cossutti, F.; Cowell, J.H.; Crawley, H.B.; Crennell, D.; Crepe-Renaudin, Sabine; Crosetti, G.; Cuevas Maestro, J.; Czellar, S.; Davenport, M.; Da Silva, W.; Deghorain, A.; Della Ricca, G.; Delpierre, P.; Demaria, N.; De Angelis, A.; De Boer, W.; De Clercq, C.; De Lotto, B.; De Min, A.; De Paula, L.; Dijkstra, H.; Di Ciaccio, L.; Dolbeau, J.; Doroba, K.; Dracos, M.; Drees, J.; Dris, M.; Duperrin, A.; Durand, J.D.; Eigen, G.; Ekelof, T.; Ekspong, G.; Ellert, M.; Elsing, M.; Engel, J.P.; Erzen, B.; Espirito Santo, M.C.; Fanourakis, G.; Fassouliotis, D.; Fayot, J.; Feindt, M.; Ferrari, P.; Ferrer, A.; Ferrer-Ribas, E.; Ferro, F.; Fichet, S.; Firestone, A.; Flagmeyer, U.; Foeth, H.; Fokitis, E.; Fontanelli, F.; Franek, B.; Frodesen, A.G.; Fruhwirth, R.; Fulda-Quenzer, F.; Fuster, J.; Galloni, A.; Gamba, D.; Gamblin, S.; Gandelman, M.; Garcia, C.; Gaspar, C.; Gaspar, M.; Gasparini, U.; Gavillet, P.; Gazis, Evangelos; Gele, D.; Ghodbane, N.; Gil Botella, Ines; Glege, F.; Gokieli, R.; Golob, B.; Gomez-Ceballos, G.; Goncalves, P.; Gonzalez Caballero, I.; Gopal, G.; Gorn, L.; Gracco, V.; Grahl, J.; Graziani, E.; Green, C.; Grimm, H.J.; Gris, P.; Grosdidier, G.; Grzelak, K.; Gunther, M.; Guy, J.; Hahn, F.; Hahn, S.; Haider, S.; Hallgren, A.; Hamacher, K.; Hansen, J.; Harris, F.J.; Hedberg, V.; Heising, S.; Hernandez, J.J.; Herquet, P.; Herr, H.; Hessing, T.L.; Heuser, J.M.; Higon, E.; Holmgren, S.O.; Holt, P.J.; Hoorelbeke, S.; Houlden, M.; Hrubec, J.; Huet, K.; Hughes, G.J.; Hultqvist, K.; Jackson, John Neil; Jacobsson, R.; Jalocha, P.; Janik, R.; Jarlskog, C.; Jarlskog, G.; Jarry, P.; Jean-Marie, B.; Johansson, Erik Karl; Jonsson, P.; Joram, C.; Juillot, P.; Kapusta, Frederic; Karafasoulis, K.; Katsanevas, S.; Katsoufis, E.C.; Keranen, R.; Kersevan, B.P.; Khomenko, B.A.; Khovansky, N.N.; Kiiskinen, A.; King, B.; Kinvig, A.; Kjaer, N.J.; Klapp, O.; Klein, Hansjorg; Kluit, P.; Kokkinias, P.; Koratzinos, M.; Kourkoumelis, C.; Kuznetsov, O.; Krammer, M.; Kriznic, E.; Krumshtein, Z.; Kubinec, P.; Kurowska, J.; Kurvinen, K.; Lamsa, J.W.; Lane, D.W.; Langefeld, P.; Laugier, J.P.; Lauhakangas, R.; Leder, G.; Ledroit, Fabienne; Lefebure, V.; Leinonen, L.; Leisos, A.; Leitner, R.; Lemonne, J.; Lenzen, G.; Lepeltier, V.; Lesiak, T.; Lethuillier, M.; Libby, J.; Liko, D.; Lipniacka, A.; Lippi, I.; Lorstad, B.; Loken, J.G.; Lopes, J.H.; Lopez, J.M.; Lopez-Fernandez, R.; Loukas, D.; Lutz, P.; Lyons, L.; MacNaughton, J.; Mahon, J.R.; Maio, A.; Malek, A.; Malmgren, T.G.M.; Maltezos, S.; Malychev, V.; Mandl, F.; Marco, J.; Marco, R.; Marechal, B.; Margoni, M.; Marin, J.C.; Mariotti, C.; Markou, A.; Martinez-Rivero, C.; Martinez-Vidal, F.; Marti i Garcia, S.; Masik, J.; Mastroyiannopoulos, N.; Matorras, F.; Matteuzzi, C.; Matthiae, G.; Mazzucato, F.; Mazzucato, M.; McCubbin, M.; McKay, R.; McNulty, R.; McPherson, G.; Meroni, C.; Meyer, W.T.; Migliore, E.; Mirabito, L.; Mitaroff, W.A.; Mjornmark, U.; Moa, T.; Moch, M.; Moller, Rasmus; Monig, Klaus; Monge, M.R.; Moreau, X.; Morettini, P.; Morton, G.; Muller, U.; Munich, K.; Mulders, M.; Mulet-Marquis, C.; Muresan, R.; Murray, W.J.; Muryn, B.; Myatt, G.; Myklebust, T.; Naraghi, F.; Nassiakou, M.; Navarria, F.L.; Navas, Sergio; Nawrocki, K.; Negri, P.; Nemecek, S.; Neufeld, N.; Nicolaidou, R.; Nielsen, B.S.; Niezurawski, P.; Nikolenko, M.; Nomokonov, V.; Normand, A.; Nygren, A.; Olshevsky, A.G.; Onofre, A.; Orava, R.; Orazi, G.; Osterberg, K.; Ouraou, A.; Paganoni, M.; Paiano, S.; Pain, R.; Paiva, R.; Palacios, J.; Palka, H.; Papadopoulou, T.D.; Papageorgiou, K.; Pape, L.; Parkes, C.; Parodi, F.; Parzefall, U.; Passeri, A.; Passon, O.; Pegoraro, M.; Peralta, L.; Pernicka, M.; Perrotta, A.; Petridou, C.; Petrolini, A.; Phillips, H.T.; Pierre, F.; Pimenta, M.; Piotto, E.; Podobnik, T.; Pol, M.E.; Polok, G.; Poropat, P.; Pozdnyakov, V.; Privitera, P.; Pukhaeva, N.; Pullia, A.; Radojicic, D.; Ragazzi, S.; Rahmani, H.; Ratoff, P.N.; Read, Alexander L.; Rebecchi, P.; Redaelli, Nicola Giuseppe; Regler, M.; Reid, D.; Reinhardt, R.; Renton, P.B.; Resvanis, L.K.; Richard, F.; Ridky, J.; Rinaudo, G.; Rodrigo, German; Rohne, O.; Romero, A.; Ronchese, P.; Rosenberg, E.I.; Rosinsky, P.; Roudeau, P.; Rovelli, T.; Royon, C.; Ruhlmann-Kleider, V.; Ruiz, A.; Saarikko, H.; Sacquin, Y.; Sadovsky, A.; Sajot, G.; Salt, J.; Sampsonidis, D.; Sannino, M.; Schneider, H.; Schwemling, P.; Schwering, B.; Schwickerath, U.; Schyns, M.A.E.; Scuri, Fabrizio; Seager, P.; Sedykh, Yu.; Segar, A.M.; Sekulin, R.; Shellard, R.C.; Sheridan, A.; Siebel, M.; Simard, L.; Simonetto, F.; Sisakian, A.N.; Smadja, G.; Smirnova, O.; Smith, G.R.; Sopczak, A.; Sosnowski, R.; Spassoff, T.; Spiriti, E.; Sponholz, P.; Squarcia, S.; Stanescu, C.; Stanic, S.; Stevenson, K.; Stocchi, A.; Strauss, J.; Strub, R.; Stugu, B.; Szczekowski, M.; Szeptycka, M.; Tabarelli, T.; Tegenfeldt, F.; Terranova, F.; Thomas, J.; Timmermans, Jan; Tinti, N.; Tkachev, L.G.; Todorova, S.; Tomaradze, A.; Tome, B.; Tonazzo, A.; Tortora, L.; Transtromer, G.; Treille, D.; Tristram, G.; Trochimczuk, M.; Troncon, C.; Tsirou, A.; Turluer, M.L.; Tyapkin, I.A.; Tzamarias, S.; Ullaland, O.; Valenti, G.; Vallazza, E.; Vander Velde, C.; Van Apeldoorn, G.W.; Van Dam, Piet; Van Doninck, Walter; Van Eldik, J.; Van Lysebetten, A.; Van Remortel, N.; Van Vulpen, I.; Vassilopoulos, N.; Vegni, G.; Ventura, L.; Venus, W.; Verbeure, F.; Verlato, M.; Vertogradov, L.S.; Verzi, V.; Vilanova, D.; Vitale, L.; Vodopianov, A.S.; Vollmer, C.; Voulgaris, G.; Vrba, V.; Wahlen, H.; Walck, C.; Weiser, C.; Wicke, D.; Wickens, J.H.; Wilkinson, G.R.; Winter, M.; Witek, M.; Wolf, G.; Yi, J.; Zalewska, A.; Zalewski, P.; Zavrtanik, D.; Zevgolatakos, E.; Zimine, N.I.; Zucchelli, G.C.; Zumerle, G.

    2000-01-01

    An updated analysis using about 1.5 million events recorded at $\\sqrt{s} =M_Z$ with the DELPHI detector in 1994 is presented. Eighteen infrared and collinear safe event shape observables are measured as a function of the polar angle of the thrust axis. The data are compared to theoretical calculations in${\\cal O} (\\alpha_s^2)$ including the event orientation. A combined fit of $\\alpha_s$ and of the renormalization scale $x_{\\mu}$ in $\\cal O(\\alpha_s^2$)yields an excellent description of the high statistics data. The weighted average from 18 observables including quark mass effects and correlations is $\\alpha_s(M_Z^2) = 0.1174 \\pm 0.0026$. The final result, derived from the jet cone energy fraction, the observable with the smallest theoretical and experimental uncertainty, is $\\alpha_s(M_Z^2) = =0:1180 0:0006(exp:) 0:0013(hadr:) 0:0008(scale) 0:0007(mass). Further studies include an s determination using theoretical predictions in the next-to-leading log approximation (NLLA), matched NLLA and O(\\alpha^{2}_{s})...

  1. The analysis, by a fusion procedure and X-ray-fluorescence spectrometry, of silicates and slags

    International Nuclear Information System (INIS)

    Jacobs, J.J.; Balaes, A.M.E.

    1980-01-01

    A glass-disc fusion method is described for the analysis, by X-ray-fluorescence spectrometry, of slags and silicate materials. The data are corrected for detector dead time and short-term instrumental drift. Corrections are made for matrix variations by use of the Lachange-Traill mathematical model, and the results are processed on a mini-computer, an iterative procedure being used in the solving of the simultaneous equations. As the alpha-correction coefficients of the Lachange-Traill model are not truly constant, a modified version of the model is proposed [af

  2. Mass Spectrometry Applications for Toxicology.

    Science.gov (United States)

    Mbughuni, Michael M; Jannetto, Paul J; Langman, Loralie J

    2016-12-01

    Toxicology is a multidisciplinary study of poisons, aimed to correlate the quantitative and qualitative relationships between poisons and their physiological and behavioural effects in living systems. Other key aspects of toxicology focus on elucidation of the mechanisms of action of poisons and development of remedies and treatment plans for associated toxic effects. In these endeavours, Mass spectrometry (MS) has become a powerful analytical technique with a wide range of application used in the Toxicological analysis of drugs, poisons, and metabolites of both. To date, MS applications have permeated all fields of toxicology which include; environmental, clinical, and forensic toxicology. While many different analytical applications are used in these fields, MS and its hyphenated applications such as; gas chromatography MS (GC-MS), liquid chromatography MS (LC-MS), inductively coupled plasma ionization MS (ICP-MS), tandem mass spectrometry (MS/MS and MS n ) have emerged as powerful tools used in toxicology laboratories. This review will focus on these hyphenated MS technologies and their applications for toxicology.

  3. Activity monitoring of alpha-bearing wastes

    International Nuclear Information System (INIS)

    Birkhoff, G.; Bondar, L.

    1980-01-01

    The paper aims at the survey on the actual situation in activity monitoring of alpha-bearing wastes. Homogeneous materials such as liquid-, gaseous- and homogeneous solid wastes are amenable to destructive analyses of representative samples. Available destructive analyses methods are sensitive and precise enough to cope with all requirements in alpha-waste monitoring. The more difficult problems are encountered with alpha-contaminated solids, when representative sampling is not practicable. Non-destructive analysis techniques are applied for monitoring this category of solid wastes. The techniques for nondestructive analysis of alpha-bearing wastes are based on the detection of gamma and/or neutron-emission of actinides. Principles and a theory of non-destructive radiometric assay of plutonium contaminated solid waste streams are explained. Guidelines for the calibration of instruments and interpretation of experimental data are given. Current theoretical and experimental development work in this problem area is reviewed. Evaluations concerning capabilities and limitations of monitoring systems for alpha-bearing solid wastes are very complex and out of the scope of this paper

  4. Role of Frontal Alpha Oscillations in Creativity

    Science.gov (United States)

    Lustenberger, Caroline; Boyle, Michael R.; Foulser, A. Alban; Mellin, Juliann M.; Fröhlich, Flavio

    2015-01-01

    Creativity, the ability to produce innovative ideas, is a key higher-order cognitive function that is poorly understood. At the level of macroscopic cortical network dynamics, recent EEG data suggests that cortical oscillations in the alpha frequency band (8 – 12 Hz) are correlated with creative thinking. However, whether alpha oscillations play a fundamental role in creativity has remained unknown. Here we show that creativity is increased by enhancing alpha power using 10 Hz transcranial alternating current stimulation (10Hz-tACS) of the frontal cortex. In a study of 20 healthy participants with a randomized, balanced cross-over design, we found a significant improvement of 7.4% in the Creativity Index measured by the Torrance Test of Creative Thinking, a comprehensive and most frequently used assay of creative potential and strengths. In a second similar study with 20 subjects, 40Hz-tACS was used in instead of 10Hz-tACS to rule out a general “electrical stimulation” effect. No significant change in the Creativity Index was found for such frontal gamma stimulation. Our results suggest that alpha activity in frontal brain areas is selectively involved in creativity; this enhancement represents the first demonstration of specific neuronal dynamics that drive creativity and can be modulated by non-invasive brain stimulation. Our findings agree with the model that alpha recruitment increases with internal processing demands and is involved in inhibitory top-down control, which is an important requirement for creative ideation. PMID:25913062

  5. Purification and characterization of alpha-amylase from rat pancreatic acinar carcinoma. Comparison with pancreatic alpha-amylase.

    OpenAIRE

    Reddy, M K; Heda, G D; Reddy, J K

    1987-01-01

    alpha-Amylase was purified to apparent homogeneity from normal pancreas and a transplantable pancreatic acinar carcinoma of the rat by affinity chromatography on alpha-glucohydrolase inhibitor (alpha-GHI) bound to aminohexyl-Sepharose 4B. Recovery was 95-100% for both pancreas and tumour alpha-amylases. They were monomeric proteins, with Mr approx. 54000 on SDS/polyacrylamide-gel electrophoresis. Isoelectric focusing of both normal and tumour alpha-amylases resolved each into two major isoenz...

  6. Opposing actions of the progesterone metabolites, 5alpha-dihydroprogesterone (5alphaP) and 3alpha-dihydroprogesterone (3alphaHP) on mitosis, apoptosis, and expression of Bcl-2, Bax and p21 in human breast cell lines.

    Science.gov (United States)

    Wiebe, John P; Beausoleil, Michel; Zhang, Guihua; Cialacu, Valentin

    2010-01-01

    Previous studies have shown that breast tissues and breast cell lines convert progesterone (P) to 5alpha-dihydroprogesterone (5alphaP) and 3alpha-dihydroprogesterone (3alphaHP) and that 3alphaHP suppresses, whereas 5alphaP promotes, cell proliferation and detachment. The objectives of the current studies were to determine if the 5alphaP- and 3alphaHP-induced changes in cell numbers are due to altered rates of mitosis and/or apoptosis, and if 3alphaHP and 5alphaP act on tumorigenic and non-tumorigenic cells, regardless of estrogen (E) and P receptor status. The studies were conducted on tumorigenic (MCF-7, MDA-MB-231, T47D) and non-tumorigenic (MCF-10A) human breast cell lines, employing several methods to assess the effects of the hormones on cell proliferation, mitosis, apoptosis and expression of Bcl-2, Bax and p21. In all four cell lines, 5alphaP increased, whereas 3alphaHP decreased cell numbers, [(3)H]thymidine uptake and mitotic index. Apoptosis was stimulated by 3alphaHP and suppressed by 5alphaP. 5alphaP resulted in increases in Bcl-2/Bax ratio, indicating decreased apoptosis; 3alphaHP resulted in decreases in Bcl-2/Bax ratio, indicating increased apoptosis. The effects of either 3alphaHP or 5alphaP on cell numbers, [(3)H]thymidine uptake, mitosis, apoptosis, and Bcl-2/Bax ratio, were abrogated when cells were treated simultaneously with both hormones. The expression of p21 was increased by 3alphaHP, and was unaffected by 5alphaP. The results provide the first evidence that 5alphaP stimulates mitosis and suppresses apoptosis, whereas 3alphaHP inhibits mitosis and stimulates apoptosis. The opposing effects of 5alphaP and 3alphaHP were observed in all four breast cell lines examined and the data suggest that all breast cancers (estrogen-responsive and unresponsive) might be suppressed by blocking 5alphaP formation and/or increasing 3alphaHP. The findings further support the hypothesis that progesterone metabolites are key regulatory hormones and that changes

  7. Low energy alphas in the drift detector

    International Nuclear Information System (INIS)

    Snowden-Ifft, D.P.; Lawson, T.; Spooner, N.J.C.; Villaume, N.

    2004-01-01

    The Directional Recoil Identification From Tracks project is a US-UK endeavor to build and operate a low pressure negative ion TPC (NITPC) to search for weakly interacting massive particles (WIMPs) thought to make up the dark matter in our Galaxy. Low energy (∼10 keV) alpha events from U and Th decays within the walls and wires of the detector can enter the active volume of the detector and be confused for WIMP interactions. This paper presents data on and a model of low energy alphas in a NITPC operated at 40 Torr CS 2 with the aim of understanding and removing this potentially serious background. A comparison of the data to this model reveals good agreement with range predictions of SRIM2000 and allows us to calculate the energy dissipation per ion pair, W=19.0±0.5 eV for low energy alphas in CS 2

  8. Liver replacement for alpha1-antitrypsin deficiency

    Science.gov (United States)

    Putnam, Charles W.; Porter, Kendrick A.; Peters, Robert L.; Ashcavai, Mary; Redeker, Allan G.; Starzl, Thomas E.

    2010-01-01

    A 16-year-old girl with advanced cirrhosis and severe alpha1-antitrypsin deficiency of the homozygous PiZZ phenotype was treated by orthotopic liver transplantation. After replacement of the liver with a homograft from a donor with the normal PiMM phenotype, the alpha1-antitrypsin concentration in the recipient’s serum rose to normal; it had the PiMM phenotype. Two and a third years later, chronic rejection necessitated retransplantation. Insertion of a homograft from a heterozygous PiMZ donar was followed by the identification of that phenotype in the recipient’s serum. Neither liver graft developed the alpha1-antitrypsin glycoprotein deposits seen with the deficiency state. These observations confirm that this hepatic- based inborn error metabolism is metabolically cured by liver replacement. PMID:320694

  9. Handbook on Mobile Gamma-ray Spectrometry

    DEFF Research Database (Denmark)

    Aage, Helle Karina; Korsbech, Uffe C C

    2003-01-01

    Basic physics and mathematics for Airborne and Car-borne Gamma-ray Spectrometry supplemented with practical examples and methods for advanced data processing......Basic physics and mathematics for Airborne and Car-borne Gamma-ray Spectrometry supplemented with practical examples and methods for advanced data processing...

  10. Peculiarities of the modern neutron spectrometry

    Indian Academy of Sciences (India)

    transition shift are discussed in the report. Keywords. Neutron spectrometry; slowing-down spectrometry; nucleosynthesis; Maxwellian neu- tron spectra. PACS Nos 29.30.Hs; 29.30.-h. “One can hardly find another field, the study of which gives so ...

  11. Improved sensitivity using liquid chromatography mass spectrometry ...

    African Journals Online (AJOL)

    Improved sensitivity using liquid chromatography mass spectrometry (LC-MS) for detection of propyl chloroformate derivatised β-N-methylamino-L-alanine (BMAA) in ... We show a 10-fold increase in sensitivity with the LC-MS method compared to the previously published gas chromatography mass spectrometry (GC-MS) ...

  12. Gamma spectrometry of infinite 4Π geometry

    International Nuclear Information System (INIS)

    Nordemann, D.J.R.

    1987-07-01

    Owing to the weak absorption og gamma radiation by matter, gamma-ray spectrometry may be applied to samples of great volume. A very interesting case is that of the gamma-ray spectrometry applied with 4Π geometry around the detector on a sample assumed to be of infinite extension. The determination of suitable efficiencies allows this method to be quantitative. (author) [pt

  13. Advances in alpha air monitoring instrumentation

    International Nuclear Information System (INIS)

    Valentine, A.M.

    1979-01-01

    Early detection of airborne radioactive material is important for effective protection of workers, particularly at facilities handling high toxicity alpha-emitting radionuclides such as 238 Pu and 239 Pu. Variable levels of ever present and naturally occurring alpha-emitting radon daughters made gross alpha air monitoring systems unreliable for live-time monitoring of airborne plutonium. Hence, good live-time monitoring was not possible until an improved alpha air monitoring instrument capable of monitoring select plutonium radionuclides of concern was developed and marketed by nuclear instrumentation companies in the USA during the late 1960s and early 1970s. This monitoring instrument utilized a solid-state silicon-diffused junction type of detector and pulse-height analyser system to achieve a radon-daughter rejection capability. This rejection capability has resulted in an improved sensitivity for specific alpha-emitting radionuclides such as 238 Pu, 239 Pu and 241 Am. Current models of this instrument are capable of detecting 40 dis/min (0.65 Bq) of plutonium alpha activity. This activity is about equal to the integrated activity workers would be exposed to if they worked for eight hours in an airborne concentration equal to the maximum permissible concentration for transportable 239 Pu. The Los Alamos Scientific Laboratory began using these instruments in its plutonium research laboratories when they became available in the early 1970s. Approximately 300 are currently in service, and their use has resulted in much improved protection of plutonium workers because accidental airborne releases can now be detected soon after they occur. General design features of these instruments are discussed together with actual operational experience and field calibration procedures. (author)

  14. Parallel Genetic Algorithm for Alpha Spectra Fitting

    Science.gov (United States)

    García-Orellana, Carlos J.; Rubio-Montero, Pilar; González-Velasco, Horacio

    2005-01-01

    We present a performance study of alpha-particle spectra fitting using parallel Genetic Algorithm (GA). The method uses a two-step approach. In the first step we run parallel GA to find an initial solution for the second step, in which we use Levenberg-Marquardt (LM) method for a precise final fit. GA is a high resources-demanding method, so we use a Beowulf cluster for parallel simulation. The relationship between simulation time (and parallel efficiency) and processors number is studied using several alpha spectra, with the aim of obtaining a method to estimate the optimal processors number that must be used in a simulation.

  15. Enteric alpha defensins in norm and pathology

    Directory of Open Access Journals (Sweden)

    Lisitsyn Nikolai A

    2012-01-01

    Full Text Available Abstract Microbes living in the mammalian gut exist in constant contact with immunity system that prevents infection and maintains homeostasis. Enteric alpha defensins play an important role in regulation of bacterial colonization of the gut, as well as in activation of pro- and anti-inflammatory responses of the adaptive immune system cells in lamina propria. This review summarizes currently available data on functions of mammalian enteric alpha defensins in the immune defense and changes in their secretion in intestinal inflammatory diseases and cancer.

  16. Clustering of Lyman-Alpha Emitters galaxies

    Science.gov (United States)

    Francke, Harold

    2009-06-01

    Galaxy clustering properties have been studied for decades to constrain cosmological parameters and have today, with large datasets of high-redshift sources piling up, become a powerful tool to discriminate and characterize primeval galaxies. In the last years, several Lyman-Alpha Emitter (LAE) galaxy samples have been gathered, which are big, uniform and compact enough to allow clustering analysis. Here we present a summary of the discussion session on the clustering properties of LAEs at the "Understanding Lyman-Alpha Emitters" conference.

  17. Diffusion of cobalt in alpha zirconium

    International Nuclear Information System (INIS)

    Ghosh, U.; Pruthi, D.D.; Anand, M.S.

    1979-01-01

    The diffusion of 60 Co in alpha zirconium has been studied in the temperature range of 873-1123 K using the sectioning technique. The diffusion parameters obey the following Arrhenius equation:- D = (1.132 +- 0.22)10 -4 exp((-136.43 +- 3.50 KJ)/RT)m 2 s -1 . The diffusivity in this phase is as high as that observed in β-phase. It is also about five orders of magnitude higher when compared to the self diffusion values. The high diffusivity of cobalt in alpha zirconium has been explained on the basis of an interstitial mechanism. (auth.)

  18. Radiological hazards of alpha-contaminated waste

    International Nuclear Information System (INIS)

    Rodgers, J.C.

    1982-01-01

    The radiological hazards of alpha-contaminated wastes are discussed in this overview in terms of two components of hazard: radiobiological hazard, and radioecological hazard. Radiobiological hazard refers to human uptake of alpha-emitters by inhalation and ingestion, and the resultant dose to critical organs of the body. Radioecological hazard refers to the processes of release from buried wastes, transport in the environment, and translocation to man through the food chain. Besides detailing the sources and magnitude of hazards, this brief review identifies the uncertainties in their estimation, and implications for the regulatory process

  19. The murine alpha B-crystallin/small heat shock protein enhancer: identification of alpha BE-1, alpha BE-2, alpha BE-3, and MRF control elements.

    OpenAIRE

    Gopal-Srivastava, R; Piatigorsky, J

    1993-01-01

    The murine alpha B-crystallin gene (a member of the small heat shock protein family) is expressed constitutively at high levels in the lens and at lower levels in many other tissues, including skeletal muscle. We have previously used the herpes simplex virus thymidine kinase promoter fused to the human growth hormone gene to identify an alpha B-crystallin enhancer at positions -427 to -259 that has high activity in muscle and low activity in lens cell lines. In the study reported here, we per...

  20. Fan-less long range alpha detector

    Science.gov (United States)

    MacArthur, Duncan W.; Bounds, John A.

    1994-01-01

    A fan-less long range alpha detector which operates by using an electrical field between a signal plane and the surface or substance to be monitored for air ions created by collisions with alpha radiation. Without a fan, the detector can operate without the possibility of spreading dust and potential contamination into the atmosphere. A guard plane between the signal plane and the electrically conductive enclosure and maintained at the same voltage as the signal plane, reduces leakage currents. The detector can easily monitor soil, or other solid or liquid surfaces.

  1. Recoil-alpha-fission and recoil-alpha-alpha-fission events observed in the reaction Ca-48 + Am-243

    NARCIS (Netherlands)

    Forsberg, U.; Rudolph, D.; Andersson, L. -L.; Nitto, A. Di; Düllmann, Ch E.; Gates, J. M.; Golubev, P.; Gregorich, K. E.; Gross, C. J.; Herzberg, R. -D.; Hessberger, F. P.; Khuyagbaatar, J.; Kratz, J. V.; Rykaczewski, K.; Sarmiento, L. G.; Schädel, M.; Yakushev, A.; Åberg, S.; Ackermann, D.; Block, M.; Brand, H.; Carlsson, B. G.; Cox, D.; Derkx, X.; Dobaczewski, J.; Eberhardt, K.; Even, J.; Fahlander, C.; Gerl, J.; Jäger, E.; Kindler, B.; Krier, J.; Kojouharov, I.; Kurz, N.; Lommel, B.; Mistry, A.; Mokry, C.; Nazarewicz, W.; Nitsche, H.; Omtvedt, J. P.; Papadakis, P.; Ragnarsson, I.; Runke, J.; Schaffner, H.; Schausten, B.; Shi, Y.; Thörle-Pospiech, P.; Torres, T.; Traut, T.; Trautmann, N.; Türler, A.; Ward, A.; Ward, D. E.; Wiehl, N.

    2016-01-01

    Products of the fusion-evaporation reaction Ca-48 + Am-243 were studied with the TASISpec set-up at the gas-filled separator TASCA at the GSI Helmholtzzentrum f\\"ur Schwerionenforschung. Amongst the detected thirty correlated alpha-decay chains associated with the production of element Z=115, two

  2. Alpha 1-adrenoceptor subtypes in the rat ventricular muscle.

    Science.gov (United States)

    Kinami, J; Tsuchihashi, H; Baba, S; Mano, F; Maruyama, K; Nagatomo, T

    1992-02-01

    Scatchard analyses of [3H]prazosin binding in rat ventricular muscle membranes showed biphasic curves, which identified alpha 1High- and alpha 1Low-affinity sites. The alpha 1High-affinity site was completely inhibited by 1 microM phenoxybenzamine. The displacement potencies of alpha 1-adrenergic antagonists were characterized by [3H]prazosin binding to alpha 1High- and alpha 1Low-affinity sites in the absence and presence of 1 microM phenoxybenzamine. The affinities of most chemicals for alpha 1Low-affinity sites were significantly lower than those for alpha 1High-affinity sites, but WB-4101 (2-(2,6-dimethoxy-phenoxyethyl)aminomethyl-1,4-benzodioxane), arotinolol, cinanserin, nifedipine, and p-aminoclonidine had the same affinities for both alpha 1Low- and alpha 1High-affinity sites. These results show that two alpha 1-adrenoceptor subtypes, alpha 1High- and alpha 1Low-affinity, are present in the rat heart, and that there are physical variations in alpha 1-adrenoceptor binding sites, based on their selectivity to antagonists.

  3. Electrophoresis-mass spectrometry probe

    Science.gov (United States)

    Andresen, Brian D.; Fought, Eric R.

    1987-01-01

    The invention involves a new technique for the separation of complex mixtures of chemicals, which utilizes a unique interface probe for conventional mass spectrometers which allows the electrophoretically separated compounds to be analyzed in real-time by a mass spectrometer. This new chemical analysis interface, which couples electrophoresis with mass spectrometry, allows complex mixtures to be analyzed very rapidly, with much greater specificity, and with greater sensitivity. The interface or probe provides a means whereby large and/or polar molecules in complex mixtures to be completely characterized. The preferred embodiment of the probe utilizes a double capillary tip which allows the probe tip to be continually wetted by the buffer, which provides for increased heat dissipation, and results in a continually operating interface which is more durable and electronically stable than the illustrated single capillary tip probe interface.

  4. Atomic mass spectrometry of materials

    Science.gov (United States)

    Anthony, J. M.; Matteson, S.; Duggan, J. L.; Elliott, P.; Marble, D.; McDaniel, F. D.; Weathers, D.

    1990-12-01

    Texas Instruments and the University of North Texas (UNT) are collaborating on the design of an accelerator mass spectrometry (AMS) system dedicated primarily to the analysis of impurities in electronic materials and metals. An AMS beamline consisting of high-resolution magnetic ( {M}/{dM } > 350) and electrostatic ( {E}/{dE } > 700) analysis followed by a surface barrier detector has been installed on the NEC 9SDH pelletron at UNT, and a "clean" ion source is under development. An existing ion source (NEC Cs sputter source) has been used in conjunction with the AMS beamline to generate computer controlled molecule-free mass analyses of solid samples. Through a careful choice of isotopes and charge states a robust algorithm can be developed for removing molecular interferences from the mass analysis for essentially all materials. Examples using graphite, Si and CdZnTe are discussed.

  5. Laser sputter neutral mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    King, B.V.; Clarke, M.; Hu, H.; Betz [Newcastle Univ., NSW (Australia). Dept. of Physics

    1993-12-31

    Laser sputter neutral mass spectrometry (LSNMS) is an emerging technique for highly sensitive surface analysis. In this technique a target is bombarded with a pulsed beam of keV ions. The sputtered particles are intercepted by a high intensity pulsed laser beam above the surface and ionised with almost 100% efficiency. The photions may then be mass analysed using a quadrupole or, more commonly, using time of flight (TOF) techniques. In this method photoions are extracted from the ionisation region, accelerated to a known energy E{sub o} and strike a channelplate detector a distance `d` away. The flight time `t` of the photoions is then related to their mass by `d` {radical}m / {radical} 2E{sub o} so measurement of `t` allows mass spectra to be obtained. It is found that LSNMS is an emerging technique of great sensitivity and flexibility, useful for both applied analysis and to investigate basic sputtering processes. 4 refs., 3 figs.

  6. Synthesis and analytics of 2,2,3,4,4-d5-19-nor-5alpha-androsterone--an internal standard in doping analysis.

    Science.gov (United States)

    Gaertner, Peter; Bica, Katharina; Felzmann, Wolfgang; Forsdahl, Guro; Gmeiner, Günter

    2007-05-01

    A short and efficient synthesis of pentadeuterated 2,2,3,4,4-d5-19-nor-5alpha-androsterone 7 starting from 19-norandrost-4-ene-3,17-dione 1 by a d1-L-Selectride mediated stereo- and regioselective reduction of the 3-keto group is presented. The use of compound 7 as internal standard for the detection of anabolic steroids via mass spectrometric techniques such as gas chromatography-mass spectrometry (GC-MS) is discussed.

  7. Six HLA-D region alpha-chain genes on human chromosome 6: polymorphisms and associations of DC alpha-related sequences with DR types.

    OpenAIRE

    Spielman, R S; Lee, J; Bodmer, W F; Bodmer, J G; Trowsdale, J

    1984-01-01

    Analysis of cosmid clones containing genes related to the HLA-DR alpha chain calls for at least six HLA-D region alpha-chain coding sequences in man; namely, DR alpha, DC alpha, DX alpha (very closely related to DC alpha), SB alpha 1, SB alpha 2 (two closely linked genes on the same cosmid clones), and DZ alpha. The first four genes have been described previously. SB alpha 2 and DZ alpha are recently identified genes, characterized by their unique and, from a limited study, nonpolymorphic ban...

  8. Phenomenological Alpha-Alpha Interactions and its Application on 16O Nucleus

    International Nuclear Information System (INIS)

    Qandil, O.S.A.A.

    2013-01-01

    The thesis includes the study of alpha-alpha interactions and apply them to the nucleus of the 16 O by using Hartree-Fock method for bosons. The used potentials are Ali-Bodmer potential, Modified Woods- Saxon potential, Fish-Bone I (FB-I) and Fish-Bone II (FB-II) potential. Also, the properties of nuclear structure of 16 O nucleus are calculated such as binding energy, form factor and root mean square radius. The results we have obtained were compared with previous results in the same field of research topic. This work requires knowledge of different kinds of potentials and the difference between the phenomenological and microscopic interactions and research in Hartree-Fock method and nuclear models, especially shell model. The content of the present thesis can be summarized as the following: The first Chapter, (Introduction), presents detailed informations about the nuclear structure, clustering, alpha clustering and nuclear models especially the shell model. Also, a review of previous researches in the research topic ( phenomenological alpha- alpha interactions). The second chapter, (Alpha-Alpha interactions), many types of phenomenological alpha-alpha interactions and its various forms are displayed, including what has been used in the thesis.The third chapter, (Derivation of Hartree-Fock Method for Bosons), illustrates the theoretical calculations which have been used in the thesis, the derivation of the Hartree-Fock method for bosons, the variational method and the derivation of binding energy, form factor and root mean square radius equations. the fourth chapter, (Numerical Results and Discussion), includes the present theoretical results of the nuclear structure of 16 O nucleus using the previous four potentials, and comparing our present results with the experimental and previous theoretical ones.

  9. Thermochemical Stability of alpha-Amino-alpha-carbonylmethyl Radicals and Their Resonance As Measured by ESR.

    Science.gov (United States)

    Welle, Frank M.; Beckhaus, Hans-Dieter; Rüchardt, Christoph

    1997-02-07

    ESR spectra of the captodative alpha-amino-alpha-carbonylmethyl radicals 8 have been recorded. No coalescence temperature for the rotation of the two NMe groups was found at temperatures below the decomposition temperature of the radicals. From known coalescence temperatures and rotational barriers of substituted methyl radicals the rotational barrier of >/=17 kcal mol(-)(1) was estimated for the (*)C-N bond in the radicals 8. Enthalpies DeltaH(diss) and entropies DeltaS(diss) of the homolytic dissociation of 7a,c,d into 8a,c,d have been obtained from equilibrium measurements by ESR. By correcting for substituent interaction enthalpies in 7 (steric and geminal), a radical stabilization enthalpy RSE = -20.7 +/- 1.0 kcal mol(-)(1) was obtained for 8. By addition of the known RSEs of dialkylamino- and carbonyl groups, a RSE = -9.9 kcal mol(-)(1) is predicted for 8. The difference between the experimental and predicted values of 10.8 kcal mol(-)(1) is attributed to a synergistic captodative substituent effect. A linear correlation between the radical stabilization enthalpies of the radicals 8 and of other mono- and disubstituted alkyl radicals and their ESR aH(alpha) coupling constants was found. According to this correlation the reduction of aH(alpha) by 1 G corresponds to an increase in RSE of 1.57 kcal mol(-)(1). The large resonance of the captodative alpha-amino-alpha-carbonylmethyl radicals 3, expressed by their high RSE, their small aH(alpha) coupling constant, and their high rotational barrier, can be rationalized by a strong interaction between the alpha-amino and the alpha-carbonyl groups similar to that in amides and expressed in the resonance structures 6.

  10. Production of pi /sup 0/ at large transverse momentum in alpha alpha and alpha p collisions at the CERN Intersecting Storage Rings

    CERN Document Server

    Karabarbounis, A; Fields, T; Filippas-Tassos, A; Fokitis, E; Goldberg, M; Kourkoumelis, C; Lissauer, D; Mannelli, I; Molzon, W; Mouzourakis, P; Palmer, R B; Rahm, David Charles; Rehak, P; Resvanis, L K; Stumer, I; Trakkas, C; Willis, W

    1981-01-01

    Inclusive pi /sup 0/ production has been measured at the CERN Intersecting Storage Rings in alpha alpha and alpha p collisions near 90 degrees , for p/sub T/ between 2 and 5 GeV/c. The differential cross sections show a slower exponential fall-off with p/sub T/ than has been observed in pp collisions at the corresponding nucleon- nucleon centre-of-mass energies at large p/sub T/. The ratio of the pi /sup 0/ production cross sections for alpha alpha collisions to those for pp collisions is observed to be larger than 16. (8 refs).

  11. A survey of the alpha-nucleon interaction

    International Nuclear Information System (INIS)

    Ali, S.; Ahmad, A.A.Z.; Ferdous, N.

    1984-10-01

    A survey of the alpha-nucleon interaction is made. The experimental work on angular distributions of differential scattering cross-sections and polarizations in proton-alpha and neutron-alpha scattering is described. The phenomenological approach which includes the study of both local and non-local potentials reproducing the experimental alpha-nucleon scattering data, is discussed. Basic studies of the alpha-nucleon interaction attempting to build an interaction between an alpha particle and a nucleon from first principles are then described. A critical discussion of the results with some concluding remarks suggesting the direction for further investigation is made. (author)

  12. Production of {alpha}-glucosidases by Bacillus sp. strains

    Energy Technology Data Exchange (ETDEWEB)

    Castro, G.R. [Univ. Nacional de Tucuman, Facultad de Bioquimica, Quimica y Farmacia, Catedra de Microbiologia Superior, PROIMI-MIRCEN, Tucuman (Argentina); Baigori, M.D. [Univ. Nacional de Tucuman, Facultad de Bioquimica, Quimica y Farmacia, Catedra de Microbiologia Superior, PROIMI-MIRCEN, Tucuman (Argentina); Sineriz, F. [Univ. Nacional de Tucuman, Facultad de Bioquimica, Quimica y Farmacia, Catedra de Microbiologia Superior, PROIMI-MIRCEN, Tucuman (Argentina)

    1995-12-31

    {alpha}-Glucosidase was detected in four wild-type amylolytic production strains belonging to the Bacillus genus. The strains showed {alpha}-glucosidase activity in extracellular and membrane-bound fractions. Kinetic studies of the {alpha}-glucosidase synthesis in the batch cultures of four strains of the Bacillus genus showed two profiles: partially and totally growth-linked synthesis. The presence of different activities and production profiles of {alpha}-glucosidase in the strains at high or low glucose concentrations in the medium would indicate that {alpha}-glucosidase may have a role in the regulation of the metabolism of {alpha}-polysaccharides. (orig.)

  13. Remarks on tilde g_{alpha}-irresolute maps

    Directory of Open Access Journals (Sweden)

    Nirmala Rebecca Paul

    2011-12-01

    Full Text Available Only a few of the class of generalized closed sets form a topology. The class of tilde g_{alpha}-closed sets is one among them. The aim of this paper is to introduce the different notions of irresolute function using tilde g_{alpha}-closed sets and study some of their basic properties.We also study the relation between strongly tilde g_{alpha}- continuous and perfectly eg-continuous functions. We also introduce tilde g_{alpha}-compact and ilde g_{alpha}-connectedspaces and study their properties using tilde g_{alpha}-continuous and eg-irresolute functions.

  14. Neuropsychiatric Complications Associated with Interferon - Alpha ...

    African Journals Online (AJOL)

    Several adverse effects have been associated with interferon alpha 2b treatment and neuropsychiatric effects have also been commonly reported. Psychosis and mood disorders have been described in the literature. This case report is of a 30 year old man with malignant melanoma stage 3a who was receiving adjuvant ...

  15. Alpha -2b treatment of Malignant Melanoma

    African Journals Online (AJOL)

    Introduction. Interferon preparations such as interferon alpha are widely used in the treatment of a number of non malignant and malignant conditions including malignant melanoma where it used. Mania has been observed in patients undergoing interferon treatment especially after significant dose- reduction or treatment ...

  16. Laboratory system for alpha particle spectroscopy

    International Nuclear Information System (INIS)

    Dean, J.R.; Chiu, N.W.

    1987-03-01

    An automated alpha particle spectroscopy system has beeen designed and fabricated. It consists of two major components, the automatic sample changer and the controller/data acquisition unit. It is capable of unattended analysis of ten samples for up to 65,000 seconds per sample

  17. Biomarkers of Alpha Particle Radiation Exposure

    Science.gov (United States)

    2014-04-01

    work towards the identification of gene-based biomarkers of alpha-particle radiation exposure. Peripheral blood mononuclear cells (PBMN) isolated from...manipulation et l’exposition au rayonnement ionisant chez les humains . CSSP-2012-CD-1117 and CSSP-2012-CD-1114 iii Table of contents...19 Acknowledgements This work was supported by the Centre for

  18. Superparamagnetic relaxation in alpha-Fe particles

    DEFF Research Database (Denmark)

    Bødker, Franz; Mørup, Steen; Pedersen, Michael Stanley

    1998-01-01

    The superparamagnetic relaxation time of carbon-supported alpha-Fe particles with an average size of 3.0 Mm has been studied over a large temperature range by the use of Mossbauer spectroscopy combined with AC and DC magnetization measurements. It is found that the relaxation time varies with tem...

  19. Extraction of molybdenum VI by alpha benzoinoxime

    International Nuclear Information System (INIS)

    Achache, M.; Meklati, M.

    1990-06-01

    The concentration of molybdenum, was studied using alpha benzoinoxime dissolved in chloroform. Several acids and salt at different levels of concentration were investigated as well as other parameters such as (mixing time, extractant to metal ratio, temperature etc.) The molybdenum stippling was also studied in alkaline medium with the subsequent recovery of the extractant and solvent

  20. Syndecan-4 associates with alpha-actinin

    DEFF Research Database (Denmark)

    Greene, Daniel K; Tumova, Sarka; Couchman, John R

    2002-01-01

    during the formation of focal adhesions. To date, a direct link between syndecan-4 and the cytoskeleton has remained elusive. We now demonstrate by Triton X-100 extraction immunoprecipitation and in vitro binding assays that the focal adhesion component alpha-actinin interacts with syndecan-4 in a beta...

  1. Genetics Home Reference: alpha-1 antitrypsin deficiency

    Science.gov (United States)

    ... rapid heartbeat upon standing. Affected individuals often develop emphysema, which is a lung disease caused by damage to the small air ... exposure to tobacco smoke accelerates the appearance of emphysema symptoms and damage to the lungs. About 10 percent of infants with alpha-1 ...

  2. Diagnosis of foetal membrane ruptures: Placental alpha ...

    African Journals Online (AJOL)

    AbstRACt. Context: Pre‑labour rupture of membranes (PROM) is a common obstetric complication which presents a diagnostic challenge, especially in equivocal cases. Standard methods of diagnosis are limited by high false positives and negatives. This study compared the accuracy of a biomarker placental alpha ...

  3. Evaluation of microcrystalline cellulose modifed from alpha ...

    African Journals Online (AJOL)

    Alpha cellulose was obtained from Costus afer and part of it was modified to microcrystalline cellulose (CAMCC). The physicochemical properties of the microcrystalline cellulose were determined and compared with those of commercial microcrystalline cellulose (Avicel 101). The swelling capacity, hydration capacity, loss ...

  4. Physicochemical and powder properties of alpha- and ...

    African Journals Online (AJOL)

    Cob alpha-celluloses (CAC) was extracted from maize cobs by defibering, delignification and bleaching; then subjected to acid hydrolysis to obtain Cob- microcrystalline-cellulose (CMCC). Their physicochemical properties were evaluated and compared with those of Avicel®, a commercial variety of microcrystalline ...

  5. Comparison of alpha decay and alpha transfer reactions in the lead region. [R matrix theory, absolute alpha widths, cross sections, 93 MeV

    Energy Technology Data Exchange (ETDEWEB)

    DeVries, R.M.

    1978-01-01

    Data were taken for five transitions in the lead region allowing a quantitative comparison with corresponding alpha-decay data via R-matrix theory using the same target + alpha nuclear potential. Good agreement between the absolute reduced widths determined from the two sets of data suggests that in transfer reactions, as in alpha decay, an alpha particle in its ground state is transferred in a one-step process. In a separate analysis, elastic and total reaction cross sections for the systems ..cap alpha.. + /sup 208/Pb, /sup 209/Bi were analyzed to obtain a limited set of potentials which, in turn, were used to calculate absolute alpha widths. Existing shell model calculations give ..gamma../sub ..cap alpha..//sup 2/ values three orders of magnitude smaller.

  6. Involvement of the clock gene Rev-erb alpha in the regulation of glucagon secretion in pancreatic alpha-cells.

    Directory of Open Access Journals (Sweden)

    Elaine Vieira

    Full Text Available Disruption of pancreatic clock genes impairs pancreatic beta-cell function, leading to the onset of diabetes. Despite the importance of pancreatic alpha-cells in the regulation of glucose homeostasis and in diabetes pathophysiology, nothing is known about the role of clock genes in these cells. Here, we identify the clock gene Rev-erb alpha as a new intracellular regulator of glucagon secretion. Rev-erb alpha down-regulation by siRNA (60-70% inhibition in alphaTC1-9 cells inhibited low-glucose induced glucagon secretion (p<0.05 and led to a decrease in key genes of the exocytotic machinery. The Rev-erb alpha agonist GSK4112 increased glucagon secretion (1.6 fold and intracellular calcium signals in alphaTC1-9 cells and mouse primary alpha-cells, whereas the Rev-erb alpha antagonist SR8278 produced the opposite effect. At 0.5 mM glucose, alphaTC1-9 cells exhibited intrinsic circadian Rev-erb alpha expression oscillations that were inhibited by 11 mM glucose. In mouse primary alpha-cells, glucose induced similar effects (p<0.001. High glucose inhibited key genes controlled by AMPK such as Nampt, Sirt1 and PGC-1 alpha in alphaTC1-9 cells (p<0.05. AMPK activation by metformin completely reversed the inhibitory effect of glucose on Nampt-Sirt1-PGC-1 alpha and Rev-erb alpha. Nampt inhibition decreased Sirt1, PGC-1 alpha and Rev-erb alpha mRNA expression (p<0.01 and glucagon release (p<0.05. These findings identify Rev-erb alpha as a new intracellular regulator of glucagon secretion via AMPK/Nampt/Sirt1 pathway.

  7. Nicotine enhances expression of the alpha 3, alpha 4, alpha 5, and alpha 7 nicotinic receptors modulating calcium metabolism and regulating adhesion and motility of respiratory epithelial cells.

    Science.gov (United States)

    Zia, S; Ndoye, A; Nguyen, V T; Grando, S A

    1997-09-01

    The purpose of this study was to investigate the possibility of direct toxic effects of nicotine (Nic) on human bronchial epithelial cells (BEC) suggested by our previous findings of functional nicotinic acetylcholine receptors (nAChRs) in the epithelial cells lining mucocutaneous membranes. We now demonstrate for the first time that human and murine BEC both in vivo and in vitro express functional nAChRs, and that classic alpha 3, alpha 4, alpha 5 and alpha 7 subunits can contribute to formation of these acetylcholine-gated ion channels. In human bronchial and mouse lung tissues, and in cultures of human BEC, the nAChRs were visualized by subunit-specific antibodies on the cell membranes, particularly at the sites of cell-to-cell contacts. The epithelial cells of submucosal glands abundantly expressed alpha 7 nAChRs. Smoking significantly (p epithelial nAChRs apparently involve regulation of cell-to-cell communications, adhesion and motility, because Mec caused rapid and profound changes in these cell functions which were reversible by Nic. An over exposure of BEC to Nic, however, produced an antagonist-like effect, suggesting that the pathobiological effects of Nic toxicity might result from both activation of nAChR channels and nAChR desensitization. We conclude that medical consequences of smoking can be mediated by direct toxic effects of inhaled Nic on the respiratory tissues wherein Nic specifically binds to and activates the nicotinic ion channels present on the cell surfaces of BEC. We believe that outside the neural system Nic interferes with functioning of non-neuronal cholinergic networks by displacing from nAChR its natural ligand acetylcholine which acts as a local hormone or cytokine in a variety of non-neuronal locations.

  8. Chromaticity separation and the alpha response.

    Science.gov (United States)

    Haigh, S M; Cooper, N R; Wilkins, A J

    2018-01-08

    Chromatic gratings can be uncomfortable to view and can evoke a large haemodynamic response. Both the discomfort and the amplitude of the haemodynamic response increase monotonically with the perceptual difference in the colour of the component bars of the grating, as registered by the separation in their chromaticity in the CIE 1976 UCS diagram. Individuals with photosensitive epilepsy exhibit epileptiform EEG activity in response to flickering light of alternate colours. The probability of the epileptiform response again increases monotonically with the separation of the colours in the CIE UCS diagram. We investigated whether alpha power, which is known to reflect the excitation of large populations of neurons, is similarly affected by the separation in chromaticity. Chromatic square-wave gratings with bars that differed in CIE UCS chromaticity were presented, together with a central fixation cross. In 18 non-clinical participants, alpha responses were recorded over the visual cortex (O1, Oz, O2, PO3, POz, PO4, P1, P2) and compared to responses in prefrontal cortex (F1, F2). Gratings comprised bars of two alternate colours that either had a small difference in chromaticity (mean CIE UCS separation of 0.03), a medium difference (mean separation of 0.19), or a large difference (mean separation of 0.43). The colour pairs had chromaticities that lay on the red-green, red-blue, or blue-green borders of the screen gamut. Regardless of the hue, the larger the separation in chromaticity, the greater the alpha desynchronization and the lower the alpha power (p = 0.004), but only in posterior electrodes (p < 0.001). Together this indicates that differences in colour evoke a cortical excitation that increases monotonically with the colour difference. In this respect the alpha response resembles the haemodynamic response. Copyright © 2017 Elsevier Ltd. All rights reserved.

  9. Determination of the cross-reactivities for alpha-zearalenol, beta-zearalenol, zearalanone, alpha-zearalanol, and beta-zearalanol on three commercial immunoaffinity columns targeting zearalenone.

    Science.gov (United States)

    Erbs, Marianne; Hartmann, Niccolo; Bucheli, Thomas D

    2007-01-01

    Immunoaffinity extraction has become increasingly important as a sample preparation and cleanup method in mycotoxin analysis. In this study, the antibody specificities of 3 commercial immunoaffinity columns (IACs) targeting zearalenone (ZON) were compared for alpha-zearalenol, beta-zearalenol, zearalanone, alpha-zearalanol, and beta-zearalanol. The recoveries of ZON and its 5 analogs were determined in triplicate when extracted from 10 mL circumneutral river water samples spiked with 20 ng analyte individually or in a mixture. The analytes were analyzed by means of electrospray ionization liquid chromatography/tandem mass spectrometry using deuterated internal standards for quantitation. Recoveries ranged from 69 to 115% for all analytes with relative standard deviations of 1-39%. Cross-reactivities for the analogs were > 80% when applied both individually and in a mixture. No significant competition effects were observed when the compounds were applied as a multianalyte mixture well below the stated IAC capacities. The results obtained here demonstrate that all IACs tested are highly cross-reactive towards the 5 ZON derivatives and may be applied for their simultaneous extraction or cleanup.

  10. The measurement of $\\alpha_s$ from event shapes with the DELPHI detector at the highest LEP energies

    CERN Document Server

    Abdallah, J; Adam, W; Adzic, P; Albrecht, T; Alderweireld, T; Alemany-Fernandez, R; Allmendinger, T; Allport, P P; Amaldi, Ugo; Amapane, N; Amato, S; Anashkin, E; Andreazza, A; Andringa, S; Anjos, N; Antilogus, P; Apel, W D; Arnoud, Y; Ask, S; Åsman, B; Augustin, J E; Augustinus, A; Baillon, Paul; Ballestrero, A; Bambade, P; Barbier, R; Bardin, Dimitri Yuri; Barker, G; Baroncelli, A; Battaglia, Marco; Baubillier, M; Becks, K H; Begalli, M; Behrmann, A; Ben-Haim, E; Benekos, N C; Benvenuti, Alberto C; Bérat, C; Berggren, M; Berntzon, L; Bertrand, D; Besançon, M; Besson, N; Bloch, D; Blom, M; Bluj, M; Bonesini, M; Boonekamp, M; Booth, P S L; Borisov, G; Botner, O; Bouquet, B; Bowcock, T J V; Boyko, I; Bracko, M; Brenner, R; Brodet, E; Brückman, P; Brunet, J M; Bugge, L; Buschmann, P; Calvi, M; Camporesi, T; Canale, V; Carena, F; Castro, N; Cavallo, F R; Chapkin, M M; Charpentier, P; Checchia, P; Chierici, R; Shlyapnikov, P; Chudoba, J; Chung, S U; Cieslik, K; Collins, P; Contri, R; Cosme, G; Cossutti, F; Costa, M J; Crennell, D J; Cuevas-Maestro, J; D'Hondt, J; Dalmau, J; Da Silva, T; Da Silva, W; Della Ricca, G; De Angelis, A; de Boer, Wim; De Clercq, C; De Lotto, B; De Maria, N; De Min, A; De Paula, L S; Di Ciaccio, Lucia; Di Simone, A; Doroba, K; Drees, J; Dris, M; Eigen, G; Ekelöf, T J C; Ellert, M; Elsing, M; Espirito-Santo, M C; Fanourakis, G K; Fassouliotis, D; Feindt, M; Fernández, J; Ferrer, A; Ferro, F; Flagmeyer, U; Föth, H; Fokitis, E; Fulda-Quenzer, F; Fuster, J A; Gandelman, M; García, C; Gavillet, P; Gazis, E N; Gokieli, R; Golob, B; Gómez-Ceballos, G; Gonçalves, P; Graziani, E; Grosdidier, G; Grzelak, K; Guy, J; Haag, C; Hallgren, A; Hamacher, K; Hamilton, K; Haug, S; Hauler, F; Hedberg, V; Hennecke, M; Herr, H; Hoffman, J; Holmgren, S O; Holt, P J; Houlden, M A; Hultqvist, K; Jackson, J N; Jarlskog, G; Jarry, P; Jeans, D; Johansson, E K; Johansson, P D; Jonsson, P; Joram, C; Jungermann, L; Kapusta, F; Katsanevas, S; Katsoufis, E C; Kernel, G; Kersevan, Borut P; Kerzel, U; Kiiskinen, A P; King, B T; Kjaer, N J; Kluit, P; Kokkinias, P; Kourkoumelis, C; Kuznetsov, O; Krumshtein, Z; Kucharczyk, M; Lamsa, J; Leder, G; Ledroit, F; Leinonen, L; Leitner, R; Lemonne, J; Lepeltier, V; Lesiak, T; Liebig, W; Liko, D; Lipniacka, A; Lopes, J H; López, J M; Loukas, D; Lutz, P; Lyons, L; MacNaughton, J; Malek, A; Maltezos, S; Mandl, F; Marco, J; Marco, R; Maréchal, B; Margoni, M; Marin, J C; Mariotti, C; Markou, A; Martínez-Rivero, C; Masik, J; Mastroyiannopoulos, N; Matorras, F; Matteuzzi, C; Mazzucato, F; Mazzucato, M; McNulty, R; Meroni, C; Migliore, E; Mitaroff, W A; Mjörnmark, U; Moa, T; Moch, M; Mönig, K; Monge, R; Montenegro, J; Moraes, D; Moreno, S; Morettini, P; Müller, U; Münich, K; Mulders, M; Mundim, L M; Murray, W; Muryn, B; Myatt, Gerald; Myklebust, T; Nassiakou, M; Navarria, Francesco Luigi; Nawrocki, K; Nicolaidou, R; Nikolenko, M; Oblakowska-Mucha, A; Obraztsov, V F; Olshevskii, A G; Onofre, A; Orava, Risto; Österberg, K; Ouraou, A; Oyanguren, A; Paganoni, M; Paiano, S; Palacios, J P; Palka, H; Papadopoulou, T D; Pape, L; Parkes, C; Parodi, F; Parzefall, U; Passeri, A; Passon, O; Peralta, L; Perepelitsa, V F; Perrotta, A; Petrolini, A; Piedra, J; Pieri, L; Pierre, F; Pimenta, M; Piotto, E; Podobnik, T; Poireau, V; Pol, M E; Polok, G; Poropat, P; Pozdnyakov, V; Pukhaeva, N; Pullia, Antonio; Rames, J; Ramler, L; Read, A; Rebecchi, P; Rehn, J; Reid, D; Reinhardt, R; Renton, P B; Richard, F; Rídky, J; Rivero, M; Rodríguez, D; Romero, A; Ronchese, P; Roudeau, Patrick; Rovelli, T; Ruhlmann-Kleider, V; Ryabtchikov, D; Sadovskii, A; Salmi, L; Salt, J; Savoy-Navarro, A; Schwickerath, U; Segar, A; Sekulin, R L; Siebel, M; Sissakian, A N; Smadja, G; Smirnova, O G; Sokolov, A; Sopczak, A; Sosnowski, R; Spassoff, Tz; Stanitzki, M; Stocchi, A; Strauss, J; Stugu, B; Szczekowski, M; Szeptycka, M; Szumlak, T; Tabarelli de Fatis, T; Taffard, A C; Tegenfeldt, F; Timmermans, J; Tkatchev, L G; Tobin, M; Todorovova, S; Tomé, B; Tonazzo, A; Tortosa, P; Travnicek, P; Treille, D; Tristram, G; Trochimczuk, M; Troncon, C; Turluer, M L; Tyapkin, I A; Tyapkin, P; Tzamarias, S; Uvarov, V; Valenti, G; van Dam, P; Van Eldik, J; Van Lysebetten, A; Van Remortel, N; Van Vulpen, I B; Vegni, G; Veloso, F; Venus, W A; Verdier, P; Verzi, V; Vilanova, D; Vitale, L; Vrba, V; Wahlen, H; Washbrook, A J; Weiser, C; Wicke, D; Wickens, J H; Wilkinson, G; Winter, M; Witek, M; Yushchenko, O P; Zalewska-Bak, A; Zalewski, Piotr; Zavrtanik, D; Zhuravlov, V; Zimin, N I; Zinchenko, A I; Zupan, M

    2004-01-01

    Hadronic event shape distributions are determined from data in e+e- collisions between 183 and 207 GeV. From these the strong coupling alpha_s is extracted in O(alpha_s^2), NLLA and matched O(alpha_s^2)+NLLA theory. Hadronisation corrections evaluated with fragmentation model generators as well as an analytical power ansatz are applied. Comparing these measurements to those obtained at and around M_Z allows a combined measurement of alpha_s from all DELPHI data and a test of the energy dependence of the strong coupling.

  11. Cytotoxic lipidic {alpha}-amino acids from the zoanthid Protopalythoa variabilis from the Northeastern coast of Brazil

    Energy Technology Data Exchange (ETDEWEB)

    Wilke, Diego Veras; Jimenez, Paula Christine; Pessoa, Claudia; Moraes, Manoel Odorico de; Costa-Lotufo, Leticia Veras [Universidade Federal do Ceara (UFC), Fortaleza, CE (Brazil). Faculdade de Medicina. Dept. de Fisiologia e Farmacologia], e-mail: lvcosta@secrel.com.br, e-mail: lvcosta@ufc.br; Araujo, Renata Mendonca; Silva, Wildson Max Barbosa da; Silveira, Edilberto Rocha; Pessoa, Otilia Deusdenia Loiola; Braz-Filho, Raimundo [Universidade Federal do Ceara (UFC), Fortaleza, CE (Brazil). Dept. de Quimica Organica e Inorganica; Lopes, Norberto Peporine [Universidade de Sao Paulo (USP), Ribeirao Preto, SP (Brazil). Faculdade de Ciencias Farmaceuticas. Dept. de Fisica e Quimica

    2009-07-01

    Two lipidic {alpha}-amino acids 1a and 1b were isolated from the zoanthid Protopalythoa variabilis using a bioguided fractionation for cytotoxic activity. The structures of the metabolites were determined by spectroscopic methods, including NMR (nuclear magnetic resonance) {sup 1}H and {sup 13}C, IR infrared) and high resolution mass spectrometry (positive mode). The cytotoxic activity of the crude extract, as well as of the mixture of 1a and 1b were measured in vitro using the MTT assay for four human tumor cell lines. This finding has important biological and chemical implications for this type of compound. This is the first report of lipidic {alpha}-amino acids from natural sources, as well as of their cytotoxic activity. (author)

  12. Mammalian peptidylglycine alpha-amidating monooxygenase (PAM) mRNA expression can be modulated by the La autoantigen

    DEFF Research Database (Denmark)

    Brenet, Fabienne; Dussault, Nadège; Borch, Jonas

    2005-01-01

    Peptidylglycine alpha-amidating monooxygenase (PAM; EC 1.14.17.3) catalyzes the COOH-terminal alpha-amidation of peptidylglycine substrates, yielding amidated products. We have previously reported a putative regulatory RNA binding protein (PAM mRNA-BP) that binds specifically to the 3' untranslated...... region (UTR) of PAM-mRNA. Here, the PAM mRNA-BP was isolated and revealed to be La protein using affinity purification onto a 3' UTR PAM RNA, followed by tandem mass spectrometry identification. We determined that the core binding sequence is approximately 15-nucleotides (nt) long and is located 471 nt...... downstream of the stop codon. Moreover, we identified the La autoantigen as a protein that specifically binds the 3' UTR of PAM mRNA in vivo and in vitro. Furthermore, La protein overexpression caused a nuclear retention of PAM mRNAs and resulted in the down-regulation of endogenous PAM activity. Most...

  13. Muramidase, alpha-1 antitrypsin, alpha-1 antichymotrypsin, and S-100 protein immunoreactivity in giant cell lesions.

    Science.gov (United States)

    Regezi, J A; Zarbo, R J; Lloyd, R V

    1987-01-01

    A spectrum of giant cell lesions was evaluated for muramidase, alpha-1 antitrypsin, alpha-1 antichymotrypsin, and S-100 protein immunoreactivity using an avidin-biotin-complex immunoperoxidase method. Peripheral giant cell granuloma, central giant cell granuloma, giant cell tumor, osteitis fibrosa cystica, cherubism, and giant cell tumor of tendon sheath showed similar patterns of reactivity. Granulomatous inflammatory lesions stained more intensely for muramidase than did noninflammatory lesions. Alpha-1-antichymotrypsin was a slightly better marker of giant cell lesions than was alpha-1-antitrypsin. Positive S-100 protein staining in half the lesions was thought to be due to the presence of Langerhans cells. The results supported the belief that giant cell lesions of bone and tendon sheath are differentiated toward cells of the mononuclear-phagocyte system and that multinucleated giant cells are derived from macrophages.

  14. Measurement of total alpha activity in water; Messung der Gesamt-Alpha-Aktivitaet in Wasser

    Energy Technology Data Exchange (ETDEWEB)

    Eikenberg, Jost [Paul Scherrer Institut (PSI), Villigen (Switzerland). Abt. fuer Strahlenschutz und Sicherheit; Florschuetz, Bernd [Hessisches Landesamt fuer Umwelt und Geologie, Kassel (Germany). Dezernat 15 - Strahlenschutz; Salvamoser, Josef [Institut fuer Angewandte Isotopen-, Gas- und Umweltuntersuchungen, Woerthsee (Germany); Steinkopff, Thomas [Deutscher Wetterdienst, Offenbach am Main (Germany); Wilhelm, Christoph [Karlsruher Institut fuer Technologie (KIT), Eggenstein-Leopoldshafen (Germany). Sicherheitsmanagement - Analytische Labore; Wisser, Sascha [FCI, Mainz (Germany)

    2014-04-01

    The article describes the measurement of the total alpha activity in an (evaporated) liquid sample, and the various sample preparation methods for measurements with proportional counters or LSC. (orig.)

  15. Protein Analysis by Mass Spectrometry

    Directory of Open Access Journals (Sweden)

    Cindic, M.

    2008-04-01

    Full Text Available Soft ionization techniques, electrospray (ESI and matrix-assisted laser desorption/ionization (MALDI make the analysis of biomolecules by mass spectrometry (MS possible. MS is used for determination of the molecular weight of peptides and protein, sequence analysis, characterization of protein-ligand interactions etc. The detection limit, resolution and mass accuracy depend on instrument used (Table 1. Impurities (buffers, salts, detergents can reduce the ion intensities or even totally suppress them, so a separation method (chromatography, 2D-gel electrophoresis must be used for purification of the sample.Molecular mass of intact protein can be determined by ESI or MALDI MS. Multiply charged ions are produced by ESI MS, while singly charged ions are predominant in MALDI spectra (Fig. 2.Sequence analysis of proteins by MS can be performed using peptide mass fingerprint. In this method, proteins are separated by 2-D gel electrophoresis and digested with specific protease (Table 2 or digested and then separated by two-dimensional chromatography (Fig. 1. The obtained peptide mixtures are analyzed by MS or MALDI-TOF technique. The masses determined by MS are compared with calculated masses from database entries. Different algorithms have been developed for protein identification. Example of posttranslational modifications (N- and O-glycosylation and protein sequence complex analysis after dual digestion (endoproteinase digestion followed by endoglycosidase digestion is shown in Fig. 3.It is known that detection of peptides by MS is influenced by intrinsic properties like amino acid composition, the basicity of the C-terminal amino acid, hydrophobicity, etc. Arginine-containing peptides dominate in MS spectra of tryptic digest, so the chemical derivatization of lysine terminal residue by O-methilisourea or 2-methoxy-4,5-1H-imidazole was suggested (Fig. 4.The peptide mass fingerprint method can be improved further by peptide fragmentation using tandem

  16. A REVIEW ON MASS SPECTROMETRY DETECTORS

    OpenAIRE

    Khatri Neetu; Gupta Ankit; Taneja Ruchi; Bilandi Ajay; Beniwal Prashant

    2012-01-01

    Mass spectrometry is an analytical technique for "weighing" molecules. Obviously, this is not done with a conventional scale or balance. Instead, mass spectrometry is based upon the principle of the motion of a charged particle that is called an ion, in an electric or magnetic field. The mass to charge ratio (m/z) of the ion affects particles motion. Since the charge of an electron is known, the mass to charge ratio (m/z) is a measurement of mass of an ion. Mass spectrometry research focuses ...

  17. Mass spectrometry at the Pittsburgh conference

    International Nuclear Information System (INIS)

    Borman, S.

    1987-01-01

    Each year analytical chemists flock to the Pittsburgh Conference to learn about the latest trends in analytical instrumentation. In this Focus, a number of prominent mass spectroscopists who attended this year's meeting in Atlantic City, NJ, discuss their perceptions of current developments in the field of mass spectrometry (MS). In the June 1 issue of Analytical Chemistry, the authors coverage of the Pittsburgh Conferences continues with a follow-up article on specific developments in hyphenated mass spectrometry - primarily liquid chromatography - MS (LC/MS) and gas chromatography - infrared spectrometry MS (GC/IR/MS)

  18. Synthesis and coupling reactions of alpha,alpha-dialkylated amino acids with nucleobase side chains.

    OpenAIRE

    Azumaya, I; Aebi, R; Kubik, S; Rebek, J

    1995-01-01

    Several di- and tripeptides containing protected purine (adenine) and pyrimidine (thymine) residues on their side chains were synthesized. The parent amino acids alpha, alpha-dialkylated in a symmetrical manner. An effective coupling procedure was developed for these sterically hindered amino acids: the fluoren-9-ylmethyloxycarbonyl-protected amino acid was dehydrated to its oxazolinone form, which was coupled in good yields with amino esters in hot tetrachloroethane.

  19. Catalytic enantioselective Michael addition reactions of alpha-nitroesters to alpha,beta-unsaturated ketones

    NARCIS (Netherlands)

    Keller, E; Veldman, N; Spek, AL; Feringa, BL

    1997-01-01

    Enantioselective Michael additions of alpha-nitroesters 2a-d with alpha,beta-unsaturated ketones were carried out in the presence of a catalytic amount of chiral Al-Li-(R,R')-2,2'-dihydroxy-1,1'-binaphthyl ('AlLiBINOL') complex prepared in situ from LiAlH4 and 2.45 equiv. of (R,R')-BINOL. The

  20. CAMEX-4 NOAA LYMAN-ALPHA HYGROMETER V1

    Data.gov (United States)

    National Aeronautics and Space Administration — The CAMEX-4 NOAA Lyman-Alpha Hygrometer dataset was collected by the NOAA Lyman-alpha Total Water Hygrometer, which was flown during the fourth field campaign in the...

  1. Alpha-(trifluoromethyl)amine derivatives via nucleophilic trifluoromethylation of nitrones.

    Science.gov (United States)

    Nelson, D W; Owens, J; Hiraldo, D

    2001-04-20

    (Trifluoromethyl)trimethylsilane (TMSCF(3)) reacts with nitrones to afford alpha-(trifluoromethyl)hydroxylamines protected as O-trimethylsilyl ethers. Potassium t-butoxide initiates the nucleophilic trifluoromethylation. The reaction works best with alpha,N-diaryl nitrones, and the conditions are compatible with a range of substituents on the aryl groups. Acidic deprotection of the nitrone/TMSCF(3) adducts generates alpha-(trifluoromethyl)hydroxylamines. Catalytic hydrogenation of the adducts produces alpha-(trifluoromethyl)amines. Nitrone/TMSCF(3) adducts with strong electron-withdrawing groups on the alpha-aryl ring or heterocyclic alpha-aryl groups undergo an elimination/addition sequence to generate alpha,alpha-bis(trifluoromethyl)amines. Nitrones with alkyl groups bound directly to the 1,3-dipolar moiety fail to react with TMSCF(3), but trifluoromethylation of beta,gamma-unsaturated nitrones followed by reduction of the double bond can circumvent this limitation.

  2. Plasma Ubiquinone, Alpha-Tocopherol and Cholesterol in Man

    DEFF Research Database (Denmark)

    Karlsson, Jan; Diamant, Bertil; Edlund, Per Olof

    1992-01-01

    Farmakologi, Coenzyme Q10, free cholesterol, vitamin E, antioxidants, Alpha-Tocopherol, vitamin Q, plasma, LDL-particle......Farmakologi, Coenzyme Q10, free cholesterol, vitamin E, antioxidants, Alpha-Tocopherol, vitamin Q, plasma, LDL-particle...

  3. Estimation of Time-Varying Autoregressive Symmetric Alpha Stable

    Data.gov (United States)

    National Aeronautics and Space Administration — In the last decade alpha-stable distributions have become a standard model for impulsive data. Especially the linear symmetric alpha-stable processes have found...

  4. Interferon alpha for chronic hepatitis D.

    Science.gov (United States)

    Abbas, Zaigham; Khan, Muhammad Arsalan; Salih, Mohammad; Jafri, Wasim

    2011-12-07

    Hepatitis D virus is a small defective RNA virus that requires the presence of hepatitis B virus infection to infect a person. Hepatitis D is a difficult-to-treat infection. Several clinical trials have been published on the efficacy of interferon alpha for hepatitis D virus (HDV) infection. However, there are few randomised trials evaluating the effects of interferon alpha, and it is difficult to judge any benefit of this intervention from the individual trials. To evaluate the beneficial and harmful effects of interferon alpha for patients with chronic hepatitis D. We identified relevant for the review randomised clinical trials by electronic searches in the Cochrane Hepato-Biliary Group Controlled Trials Register, the Cochrane Central Register of Controlled Trials (CENTRAL) in The Cochrane Library, MEDLINE, EMBASE, and Science Citation Index Expanded until May 2011. We also checked the bibliographic references of identified randomised trials, textbooks, and review articles in order to find randomised trials not identified by the electronic searches. Randomised clinical trials evaluating interferon alpha versus placebo or no intervention for patients with chronic hepatitis D infection. Two authors assessed the trials and extracted data on mortality, virologic, biochemical, and histological response as well as adverse events at end of treatment and six months or more after completing treatment. The analyses were performed using the intention-to-treat principle including all randomised participants irrespective of follow-up. Drop-outs, withdrawals, and non-compliance were considered as treatment failures. Data were analysed with fixed- and random-effects models. Reported results were based on fixed-effect model except in cases where statistical significance varied between the two models. Six randomised trials fulfilled the inclusion criteria. Two hundred and one randomised participants (male = 174) were included. The risk of bias in all the included trials was high

  5. Neurosteroids: Can a 2alpha,3alpha-epoxy ring make up for the 3alpha-hydroxyl group?

    Czech Academy of Sciences Publication Activity Database

    Kasal, Alexander; Buděšínský, Miloš; Mareš, Pavel; Krištofíková, Z.; Leitao, A. J.; Sá e Melo, M. L.; Silva, M. M. C.

    2016-01-01

    Roč. 105, Jan (2016), s. 12-18 ISSN 0039-128X R&D Projects: GA ČR(CZ) GA305/09/0846; GA ČR(CZ) GBP304/12/G069 Institutional support: RVO:61388963 ; RVO:67985823 Keywords : neurosteroids * NMR spectrometry * GABA (A) receptor * TBPS-test Subject RIV: CC - Organic Chemistry; FH - Neurology (FGU-C) Impact factor: 2.282, year: 2016

  6. Silicon vertex detector upgrade in the ALPHA experiment

    CERN Document Server

    Amole, C; Ashkezari, M.D; Baquero-Ruiz, M; Bertsche, W; Burrows, C; Butler, E; Capra, A; Cesar, C.L; Chapman, S; Charlton, M; Deller, A; Eriksson, S; Fajans, J; Friesen, T; Fujiwara, M.C; Gill, D.R; Gutierrez, A; Hangst, J.S; Hardy, W.N; Hayden, M.E; Humphries, A.J; Isaac, C.A; Jonsell, S; Kurchaninov, L; Little, A; Madsen, N; McKenna, J.T.K; Menary, S; Napoli, S.C; Nolan, P; Olchanski, K; Olin, A; Povilus, A; Pusa, P; Rasmussen, C.Ø; Robicheaux, F; Sacramento, R.L; Sampson, J.A; Sarid, E; Seddon, D; Silveira, D.M; So, C; Stracka, S; Tharp, T; Thompson, R.I; Thornhill, J; Tooley, M.P; Van Der Werf, D.P; Wells, D

    2013-01-01

    The Silicon Vertex Detector (SVD) is the main diagnostic tool in the ALPHA-experiment. It provides precise spatial and timing information of antiproton (antihydrogen) annihilation events (vertices), and most importantly, the SVD is capable of directly identifying and analysing single annihilation events, thereby forming the basis of ALPHA ' s analysis. This paper describes the ALPHA SVD and its upgrade, installed in the ALPHA ' s new neutral atom trap.

  7. Expression of alpha-amylase in Bacillus licheniformis.

    OpenAIRE

    Rothstein, D M; Devlin, P E; Cate, R L

    1986-01-01

    In Bacillus licheniformis, alpha-amylase production varied more than 100-fold depending on the presence or absence of a catabolite-repressing carbon source in the growth medium. alpha-Amylase was produced during the growth phase and not at the onset of the stationary phase. Induction of alpha-amylase correlated with synthesis of mRNA initiating at the promoter of the alpha-amylase gene.

  8. Proton transfer reaction - mass spectrometry

    International Nuclear Information System (INIS)

    Cappellin, L.

    2012-01-01

    Proton transfer reaction mass spectrometry (PTR-MS) provides on-line monitoring of volatile organic compounds (VOCs) with a low detection threshold and a fast response time. Commercially available set-ups are usually based on quadrupole analysers but recently new instruments based on time-of-flight (PTR-ToF-MS) analysers have been proposed and commercialized. PTR-MS has been successfully applied to a variety of fields including environmental science, food science and technology, plant physiology and medical science. Many new challenges arise from the newly available PTR-ToF-MS instruments, ranging from mass calibration and absolute VOC concentration determination to data mining and sample classification. This thesis addresses some of these problems in a coherent framework. Moreover, relevant applications in food science and technology are presented. It includes twelve papers published in peer reviewed journals. Some of them address methodological issues regarding PTR-ToF-MS; the others contain applicative studies of PTR-ToF-MS to food science and technology. Among them, there are the first two published applications of PTR-ToF-MS in this field. (author)

  9. Photon spectrometry utilizing neural networks

    International Nuclear Information System (INIS)

    Silveira, R.; Benevides, C.; Lima, F.; Vilela, E.

    2015-01-01

    Having in mind the time spent on the uneventful work of characterization of the radiation beams used in a ionizing radiation metrology laboratory, the Metrology Service of the Centro Regional de Ciencias Nucleares do Nordeste - CRCN-NE verified the applicability of artificial intelligence (artificial neural networks) to perform the spectrometry in photon fields. For this, was developed a multilayer neural network, as an application for the classification of patterns in energy, associated with a thermoluminescent dosimetric system (TLD-700 and TLD-600). A set of dosimeters was initially exposed to various well known medium energies, between 40 keV and 1.2 MeV, coinciding with the beams determined by ISO 4037 standard, for the dose of 10 mSv in the quantity Hp(10), on a chest phantom (ISO slab phantom) with the purpose of generating a set of training data for the neural network. Subsequently, a new set of dosimeters irradiated in unknown energies was presented to the network with the purpose to test the method. The methodology used in this work was suitable for application in the classification of energy beams, having obtained 100% of the classification performed. (authors)

  10. Difraction spectrometry by laser beams

    Directory of Open Access Journals (Sweden)

    Frías, M.

    1988-12-01

    Full Text Available The advances in laser technology have permitted the development of numerous applications, in particular diffraction spectrometry by laser beams for the determination of the distribution curve of the particle sizes of different materials; this permits one to obtain the distribution of particle size in both wet and dry materials. In the present paper a brief description of the technique and its principles is offered. The results obtained with different materials-limestone clay, gypsum, Portland cement and siliceous materials are given.

    Los avances en la tecnología laser han permitido el desarrollo de múltiples aplicaciones, en concreto la espectrometría de difracción de rayos laser para la determinación de la curva de distribución del tamaño de partícula de diferentes materiales, y que permite la obtención de la misma tanto en seco como en húmedo. En este trabajo se hace una descripción breve de la técnica y de sus fundamentos. Se presentan resultados con diferentes materiales: caliza, arcilla, yeso, cemento Portland y materiales silíceos.

  11. NICHD Biomedical Mass Spectrometry Core Facility

    Data.gov (United States)

    Federal Laboratory Consortium — The NICHD Biomedical Mass Spectrometry Core Facility was created under the auspices of the Office of the Scientific Director to provide high-end mass-spectrometric...

  12. Pyrolysis - gas chromatography - mass spectrometry of lignins

    Energy Technology Data Exchange (ETDEWEB)

    Martin, F.; Saiz-Jimenez, C.; Gonzalez-Vila, F.J.

    1979-01-01

    Milled wood lignins from spruce, beech and bamboo were pyrolysed. The high-boiling products of pyrolysis were studied by GLC and mass spectrometry. The forty-three products identified provide information on the structural units of lignin.

  13. Mass Spectrometry-Based Biomarker Discovery.

    Science.gov (United States)

    Zhou, Weidong; Petricoin, Emanuel F; Longo, Caterina

    2017-01-01

    The discovery of candidate biomarkers within the entire proteome is one of the most important and challenging goals in proteomic research. Mass spectrometry-based proteomics is a modern and promising technology for semiquantitative and qualitative assessment of proteins, enabling protein sequencing and identification with exquisite accuracy and sensitivity. For mass spectrometry analysis, protein extractions from tissues or body fluids and subsequent protein fractionation represent an important and unavoidable step in the workflow for biomarker discovery. Following extraction of proteins, the protein mixture must be digested, reduced, alkylated, and cleaned up prior to mass spectrometry. The aim of our chapter is to provide comprehensible and practical lab procedures for sample digestion, protein fractionation, and subsequent mass spectrometry analysis.

  14. Stable isotope mass spectrometry in petroleum exploration

    International Nuclear Information System (INIS)

    Mathur, Manju

    1997-01-01

    The stable isotope mass spectrometry plays an important role to evaluate the stable isotopic composition of hydrocarbons. The isotopic ratios of certain elements in petroleum samples reflect certain characteristics which are useful for petroleum exploration

  15. Mass Spectrometry Analyses of Multicellular Tumor Spheroids.

    Science.gov (United States)

    Acland, Mitchell; Mittal, Parul; Lokman, Noor A; Klingler-Hoffmann, Manuela; Oehler, Martin K; Hoffmann, Peter

    2017-12-11

    Multicellular tumor spheroids (MCTS) are a powerful biological in vitro model, which closely mimics the 3D structure of primary avascularized tumors. Mass spectrometry (MS) has established itself as a powerful analytical tool, not only to better understand and describe the complex structure of MCTS, but also to monitor their response to cancer therapeutics. The first part of this review focuses on traditional mass spectrometry approaches with an emphasis on elucidating the molecular characteristics of these structures. Then the mass spectrometry imaging (MSI) approaches used to obtain spatially defined information from MCTS is described. Finally the analysis of primary spheroids, such as those present in ovarian cancer, and the great potential that mass spectrometry analysis of these structures has for improved understanding of cancer progression and for personalized in vitro therapeutic testing is discussed. © 2017 The Authors. PROTEOMICS - Clinical Applications Published by WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. Introduction to mass spectrometry-based proteomics

    DEFF Research Database (Denmark)

    Matthiesen, R.; Bunkenborg, J.

    2013-01-01

    Mass spectrometry has been widely applied to study biomolecules and one rapidly developing field is the global analysis of proteins, proteomics. Understanding and handling mass spectrometry data is a multifaceted task that requires many decisions to be made to get the most comprehensive information...... from an experiment. Later chapters in this book deal in-depth with various aspects of the process and how different tools can be applied to the many analytical challenges. This introductory chapter is intended as a basic introduction to mass spectrometry (MS)-based proteomics to set the scene...... for newcomers and give pointers to reference material. There are many applications of mass spectrometry in proteomics and each application is associated with some analytical choices, instrumental limitations and data processing steps that depend on the aim of the study and means of conducting it. Different...

  17. Mass spectrometry of fluorocarbon-labeled glycosphingolipids

    DEFF Research Database (Denmark)

    Li, Yunsen; Arigi, Emma; Eichert, Heather

    2010-01-01

    A method for generation of novel fluorocarbon derivatives of glycosphingolipids (GSLs) with high affinity for fluorocarbon phases has been developed, and their potential applications to mass spectrometry (MS)-based methodologies for glycosphingolipidomics have been investigated. Sphingolipid...

  18. Covariation of spectral and nonlinear EEG measures with alpha biofeedback.

    NARCIS (Netherlands)

    Fell, J.; Elfadil, H.; Klaver, P.; Roschke, J.; Elger, C.E.; Fernandez, G.S.E.

    2002-01-01

    This study investigated how different spectral and nonlinear EEG measures covaried with alpha power during auditory alpha biofeedback training, performed by 13 healthy subjects. We found a significant positive correlation of alpha power with the largest Lyapunov-exponent, pointing to an increased

  19. Particularization of alpha contamination using CR-39 track detectors

    Indian Academy of Sciences (India)

    Solid-state nuclear track detectors have found wide use in various domains of science and technology, e.g. in environmental experiments. The measurement of alpha activity on sources in an environment, such as air is not easy because of short penetration range of alpha particles. Furthermore, measurement of alpha ...

  20. Mass spectrometry of long-lived radionuclides

    International Nuclear Information System (INIS)

    Becker, Johanna Sabine.

    2003-01-01

    The capability of determining element concentrations at the trace and ultratrace level and isotope ratios is a main feature of inorganic mass spectrometry. The precise and accurate determination of isotope ratios of long-lived natural and artificial radionuclides is required, e.g. for their environmental monitoring and health control, for studying radionuclide migration, for age dating, for determining isotope ratios of radiogenic elements in the nuclear industry, for quality assurance and determination of the burn-up of fuel material in a nuclear power plant, for reprocessing plants, nuclear material accounting and radioactive waste control. Inorganic mass spectrometry, especially inductively coupled plasma mass spectrometry (ICP-MS) as the most important inorganic mass spectrometric technique today, possesses excellent sensitivity, precision and good accuracy for isotope ratio measurements and practically no restriction with respect to the ionization potential of the element investigated--therefore, thermal ionization mass spectrometry (TIMS), which has been used as the dominant analytical technique for precise isotope ratio measurements of long-lived radionuclides for many decades, is being replaced increasingly by ICP-MS. In the last few years instrumental progress in improving figures of merit for the determination of isotope ratio measurements of long-lived radionuclides in ICP-MS has been achieved by the application of a multiple ion collector device (MC-ICP-MS) and the introduction of the collision cell interface in order to dissociate disturbing argon-based molecular ions, to reduce the kinetic energy of ions and neutralize the disturbing noble gas ions (e.g. of 129 Xe + for the determination of 129 I). The review describes the state of the art and the progress of different inorganic mass spectrometric techniques such as ICP-MS, laser ablation ICP-MS vs. TIMS, glow discharge mass spectrometry, secondary ion mass spectrometry, resonance ionization mass

  1. Fast atom bombardment tandem mass spectrometry of carotenoids

    Energy Technology Data Exchange (ETDEWEB)

    van Breeman, R.B. [Univ. of Illinois, Chicago, IL (United States); Schmitz, H.H.; Schwartz, S.J. [North Carolina State Univ., Raleigh, NC (United States)

    1995-02-01

    Positive ion fast atom bombardment (FAB) tandem mass spectrometry (MS-MS) using a double-focusing mass spectrometer with linked scanning at constant B/E and high-energy collisionally activated dissociation (CAD) was used to differentiate 17 different cartenoids, including {beta}-apo-8{prime}- carotenal, astaxanthin, {alpha}-carotene, {beta}-carotene, {gamma}-carotene, {zeta}-carotene, canthaxanthin, {beta}-cryptoxanthin, isozeaxanthin bis (pelargonate), neoxanthin, neurosporene, nonaprene, lutein, lycopene, phytoene, phytofluene, and zeaxanthin. The carotenoids were either synthetic or isolated from plant tissues. The use of FAB ionization minimized degradation or rearrangement of the carotenoid structures due to the inherent thermal instability generally ascribed to these compounds. Instead of protonated molecules, both polar xanthophylls and nonpolar carotenes formed molecular ions, M{sup {center_dot}+}, during FAB ionization. Following collisionally activated dissociation, fragment ions of selected molecular ion precursors showed structural features indicative of the presence of hydroxyl groups, ring systems, ester groups, and aldehyde groups and the extent of aliphatic polyene conjugation. The fragmentation patterns observed in the mass spectra herein may be used as a reference for the structural determination of carotenoids isolated from plant and animal tissues. 18 refs., 4 figs.

  2. Determination of sulphur with total reflection x-ray spectrometry

    International Nuclear Information System (INIS)

    Steinmeyer, S.; Kolbesen, B.O.

    2000-01-01

    The potential and limitations of total reflection x-ray spectrometry (TXRF) were tested for the quantitative determination of the light element sulphur in inorganic and biological samples. As representatives of inorganic samples alkali, transition metal, magnesium and aluminum sulphates were investigated. As biological samples the sulphur containing amino acid methionine and the pharmaceutical drug insulin were chosen. All measurements were performed on a TXRF-spectrometer EXTRA IIA (Atomika Instruments, Oberschleissheim/Germany) using tungsten L-radiation as the excitation tube. Various concentrations of all samples ranging from 20 mg/l to 0.5 mg/l were determined. In addition the surface topography and thickness of the dry residue of these samples were investigated with SEM and a thickness profilometer (Alpha-Step). The result show that the reliable determination of sulphur in sulphates depends on the cation involved. Alkali sulphates like Na 2 SO 4 , or K 2 SO 4 form bulky residues resulting in significant deviations of the recovery rate of sulphur. In this case the use of smoothing detergents like 1 % HF, 1 % malic acid and 2 % hydrazinhydrat was found to be necessary for accurate determination. The results for the biological samples agree well with the expected values. The investigations lead to the conclusion that TXRF combined with a proper samples preparation is well suited for the determination of sulphur in different samples with various concentrations and matrices. (author)

  3. Thirteenth ISMAS symposium cum workshop on spectrometry

    International Nuclear Information System (INIS)

    Aggarwal, S.K.; Jaison, P.G.; Alamelu, D.

    2008-01-01

    Mass spectrometry is an important analytical tool and finds applications in almost all branches of science and technology like Physics, Chemistry, Biology, Material Science, Geology, Nuclear Science, Industry, Oceanography, Environment etc. Innovations in the designs of mass spectrometers coupled with new ionization techniques have further strengthened the capabilities of mass spectrometry for analyzing all types of molecules including thermally labile and non-volatile at concentrations down to femto gram levels. The applications of mass spectrometry to the biomedical sciences have provided a unique, easy and fast approach to genomics, proteomics and metabolomics. The availability of different types of mass spectrometers for inorganic elemental and isotopic composition determination have strengthened the role of mass spectrometry for analyzing all elements starting from hydrogen onwards. It is now possible to carry out speciation analysis using electrospray mass spectrometry. The individual conference papers in the proceedings covers fundamentals of mass spectrometry, qualitative and quantitative aspects and data interpretation, maintenance of mass spectrometers, selection of mass spectrometer, and recent advances in the field. Papers relevant to INIS are indexed separately

  4. Alpha blockers: A relook at phenoxybenzamine

    Directory of Open Access Journals (Sweden)

    Sambhunath Das

    2017-01-01

    Full Text Available Phenoxybenzamine (PBZ is an alpha adrenergic antagonist, used for the management of hypertension. PBZ acts by blocking alpha-adrenergic receptors, leading to vasodilatation and low systemic vascular resistance. This helps in control of blood pressure in pheochromocytoma, improvement of systemic oxygen delivery, and optimization of the Qp/Qs in pediatric cardiac surgery such as hypoplastic left heart syndrome and improving perfusion parameters during open heart surgery. The uses have further extended to causalgia, Raynaud's phenomenon, autonomic hyperreflexia, and even for patency of radial artery conduit in coronary artery bypass grafting surgery. However, its prolonged hypotensive effect limits the regular use. In this review, we discussed the mechanism of action, pharmaco-physiology of PBZ, perioperative uses in different clinical setting and controversies for its uses; publications in different scientific journals from the previous years.

  5. The Alpha Magnetic Spectrometer Silicon Tracker

    CERN Document Server

    Burger, W J

    1999-01-01

    The Alpha Magnetic Spectrometer (AMS) is designed as a independent module for installation on the International Space Station Alpha (ISSA) in the year 2002 for an operational period of three years. The principal scientific objectives are the searches for antimatter and dark matter in cosmic rays. The AMS uses 5.5 m sup 2 of silicon microstrip sensors to reconstruct charged particle trajectories in the field of a permanent magnet. The detector design and construction covered a 3 yr period which terminated with a test flight on the NASA space shuttle Discovery during June 2-12, 1988. In this contribution, we describe the shuttle version of the AMS silicon tracker, including preliminary results of the tracker performance during the flight. (author)

  6. Alpha-contaminated waste management workshop

    International Nuclear Information System (INIS)

    1982-12-01

    These proceedings are published to provide a record of the oral presentations made at the DOE Alpha-Contaminated Workshop held in Gaithersburg, Maryland, on August 10-13, 1982. The papers are transcriptions of these oral presentations and, as such, do not contain as significant detail as will be found in the reviewed papers to be published in the periodical Nuclear and Chemical Waste Management in the first issue for 1983. These transcriptions have been reviewed by the speakers and some illustrations have been provided, but these contain only the preliminary information that will be provided in the technical papers to be published in the periodical. These papers have been grouped under the following headings: source terms; disposal technology and practices for alpha-contaminated waste; risk analyses and safety assessments. These papers in addition to those dealing with legislative and regulatory aspects have been abstracted and indexed for the Energy Data Base

  7. Sneutrino Inflation with $\\alpha$-attractors

    CERN Document Server

    Kallosh, Renata; Roest, Diederik; Wrase, Timm

    2016-11-22

    Sneutrino inflation employs the fermionic partners of the inflaton and stabilizer field as right-handed neutrinos to realize the seesaw mechanism for light neutrino masses. A crucial ingredient in existing constructions for sneutrino (multi-)natural inflation is an unbroken discrete shift symmetry. We demonstrate that a similar construction applies to $\\alpha$-attractor models. In this case the hyperbolic geometry protects the neutrino Yukawa couplings to the inflaton field, and the masses of leptons and Higgs fields, from blowing up when the inflaton is super-Planckian. We find that the predictions for $n_s$ and $r$ for $\\alpha$-attractor cosmological models, compatible with the current cosmological data, are preserved in the presence of the neutrino sector.

  8. The ALPHA project: a progress report

    International Nuclear Information System (INIS)

    Yadigaroglu, G.; Cachard, F. de; Coddington, P.; Dreier, J.; Smith, B.; Guentay, S.; Varadi, G.

    1995-01-01

    A review of the ALPHA project is presented, including a summary of progress and current status. The project comprises the experimental and analytical investigation of the long-term decay heat removal phenomena from the containment of the next generation of 'passive' Advanced Light Water Reactors. The effects of aerosols that may result from hypothetical severe accidents are also considered. The construction of the major ALPHA experimental facilities, PANDA, LINX-2 and AIDA, has been completed and all facilities are now in their commissioning phases. Scaling studies have guided the design of the experimental facilities. Several small-scale experiments and studies have already produced valuable results which can be used to direct the experimental work, as well as the design of the passive ALWRs. (author) 7 figs., 23 refs

  9. Alpha Resonant States in 13C

    International Nuclear Information System (INIS)

    Rodrigues, M. R. D.; Borello-Lewin, T.; Horodynski-Matsushigue, L. B.; Duarte, J. L. M.; Rodrigues, C. L.; Souza, M. A.; Miyake, H.; Cunsolo, A.; Cappuzzello, F.; Ukita, G. M.

    2011-01-01

    The 9 Be( 6 Li,d) 13 C reaction was used to investigate alpha resonant states in 13 C up to 15 MeV of excitation. The reaction was measured at a bombarding energy of 25.5 MeV employing the Sao Paulo Pelletron-Enge-Spectrograph facility and the nuclear emulsion detection technique. An energy resolution of 50 keV was obtained. Several narrow alpha resonant states not previously measured were detected, in particular the one at the (3α+n) threshold populated by an L = 2 transfer, revealing a 9 Be+α component for the 1/2 - cluster state candidate at this threshold. Experimental angular distributions are presented in comparison with DWBA predictions.

  10. Ripple loss of alpha particles in ITER

    International Nuclear Information System (INIS)

    Tani, Keiji; Takizuka, Tomonori; Azumi, Masafumi

    1989-07-01

    Part I: A benchmark test for the ripple loss of alpha particles in ITER has been executed by using an orbit-following Monte-Carlo (OFMC) code. In ITER with a plasma current of the order of 10 MA and an edge ripple of the order of 3%, the total power-loss fraction derived by JAERI's OFMC code is 6.6%. Part II: Two dimensional heat load on the first wall due to ripple loss of alpha particles in ITER has been estimated by using an OFMC code. The peak heat load due to ripple-trapped loss is of the order of 0.1 MW/m 2 . The peak heat load by ripple-untrapped loss averaged over the toroidal angle is about 0.07 MW/m 2 . (author)

  11. Non destructive and destructive dating by low energy gamma ray spectrometry

    International Nuclear Information System (INIS)

    Brrada, M.; Choukri, A.; El-Khoukhi, T.

    1994-01-01

    Alpha spectrometry is mainly used in U-series dating for the determination of equilibrium ratios, but chemical attacks, radiochemical separations, preparations of thin layers are needed. To avoid this destructive method, gamma spectrometry in the 40-380 KeV region by coaxial Germanium detectors, was also used, but 234-U is still difficult to determine because its 53.2 KeV gamma ray interferes absolutely with the 10 times more intense gamma ray of 214-Pb. In our work we were interested in the 20-80 KeV region of the gamma spectrum obtained by a small Germanium planar detector having an excellent resolution. It contains the 25.6, 27.4, 50.2, 63.3 and 67.7 KeV gamma rays emitted respectively by 231-Th, 231-Pa, 227-Th, (234-U + 214-Pb), 234-Th and 230-Th, which are all the radionuclides needed for dating. The peaks obtained with such a detector are better resolved, with a lower background, because this detector is less sensitive to higher energy and more intense gamma rays coming from 226-Ra decay products, than the voluminous coaxial detector. We worked on a geological sample containing uranium and coming from the Ganntour moroccan phosphate ore. In this paper we present 3 gamma ray spectra, one obtained directly with a Germanium coaxial detector in the 40-380 KeV region, the second obtained directly with a germanium planar detector in the 20-80 KeV region, and the third obtained after chemical separation of radium, with a germanium planar detector in the 20-80 KeV region. Good agreement was found with the results of alpha spectrometry. 2 figs., 1 tab., 2 refs. (author)

  12. Determination of alpha radionuclides in fish

    International Nuclear Information System (INIS)

    Pernicka, L.; Matel, L.; Rosskopfova, O.

    2001-01-01

    In atmospheric water, external water and undercurrent the occurrence of radionuclides is usual. It is an important factor of quality of the environment. Plants ingest radionuclides from water and with they everyone. And it arises radioactivity infest food-chain. Radiotoxicity of this radionuclides is very deer sometimes. The sensitive radiochemical procedures for their determination are necessarily important. The poster presents the combined procedure used at our laboratory for determination of alpha radionuclides in biological samples. (authors)

  13. Alpha autoradiography by cellulose nitrate layer

    International Nuclear Information System (INIS)

    Simonovic, J.; Vukovic, J.; Antanasijevic, R.

    1977-01-01

    From domestic cellulose nitrate bulk material thin layers for α-particle autoradiography were prepared. An artificial test specimen of a uniformly alpha labelled grid source was used. The efficiency of autoradiography by cellulose nitrate was calculated comparing with data from an Ilford K2 nuclear emulsion exposed under the same conditions as the cellulose nitrate film. The resolution was determined as the distance from grid pitch edge at which the track density fell considerably. (Auth.)

  14. Alpha autoradiography by cellulose nitrate layer

    International Nuclear Information System (INIS)

    Simonovic, J.; Vukovic, J.; Antanasijevic, R.

    1976-01-01

    From domestic cellulose nitrate bulk material thin layers for α-particle autoradiography were prepared. An artifical test specimen of a uniformly alpha labelled grid source was used. The efficiency of autoradiographs by cellulose nitrate was calculated comparing with data from an Ilford K2 nuclear emulsion exposed under the same conditions as the cellulose nitrate film. The resolution was determined as the distance from grid pitch edge at which the track density fell considerably. (orig.) [de

  15. Effects of internally deposited alpha emitters

    International Nuclear Information System (INIS)

    Rundo, J.; Schlenker, R.A.; Stebbings, J.H.

    1985-01-01

    This study seeks to identify and quantify the human health effects of occupational exposures to radium, use the health effects data from the radium study to predict responses to other alpha-emitting and/or bone-seeking radionuclides at occupational exposure levels and above, and predict the effects of these radionuclides, specifically environmental radium and its daughters, at nonoccupational exposure levels. 14 refs

  16. Alpha Emitting Radionuclides and Radiopharmaceuticals for Therapy

    International Nuclear Information System (INIS)

    Chérel, Michel; Barbet, Jacques

    2013-01-01

    Today, cancer treatments mainly rely on surgery or external beam radiation to remove or destroy bulky tumors. Chemotherapy is given when tumours cannot be removed or when dissemination is suspected. However, these approaches cannot permanently treat all cancers and relapse occurs in up to 50% of the patients’ population. Radioimmunotherapy (RIT) and peptide receptor radionuclide therapy (PRRT) are effective against some disseminated and metastatic diseases, although they are rarely curative. Most preclinical and clinical developments in this field have involved electron-emitting radionuclides, particularly iodine-131, yttrium-90 and lutetium-177. The large range of the electrons emitted by these radionuclides reduces their efficacy against very small tumour cell clusters or isolated tumour cells present in residual disease and in many haematological tumours (leukaemia, myeloma). The range of alpha particles in biological tissues is very short, less than 0.1 mm, which makes alpha emitters theoretically ideal for treatment of such isolated tumour cells or micro-clusters of malignant cells. Thus, over the last decade, a growing interest for the use of alpha-emitting radionuclides has emerged. Research on targeted alpha therapy (TAT) began years ago in Nantes through cooperation between Subatech, a nuclear physics laboratory, CRCNA, a cancer research centre with a nuclear oncology team and ITU (Karlsruhe, Germany). CD138 was demonstrated as a potential target antigen for Multiple Myeloma, which is a target of huge clinical interest particularly suited for TAT because of the disseminated nature of the disease consisting primarily of isolated cells and small clusters of tumour cells mainly localized in the bone marrow. Thus anti-CD138 antibodies were labelled with bismuth-213 from actinium-225/bismuth-213 generators provided by ITU and used to target multiple myeloma cells. In vitro studies showed cell cycle arrest, synergism with chemotherapy and very little induction

  17. Alpha-particle Gas Pressure Gauge

    Science.gov (United States)

    Buehler, M. G.; Bell, L. D.; Hecht, M. H.

    1995-01-01

    Described are preliminary results obtained on a novel gas pressure gauge that operates between 0.1 and 1000 mb. This gauge uses a 1- micron Ci alpha particle source to ionize the gas in a small chamber with an electric field imposed between anode and cathode electrodes that drives positive ions to the cathode where they are collected electronically. This gauge could make Martian pressure measurements.

  18. Proceedings, High-Precision $\\alpha_s$ Measurements from LHC to FCC-ee

    Energy Technology Data Exchange (ETDEWEB)

    d' Enterria, David [CERN; Skands, Peter Z. [Monash U.

    2015-01-01

    This document provides a writeup of all contributions to the workshop on "High precision measurements of $\\alpha_s$: From LHC to FCC-ee" held at CERN, Oct. 12--13, 2015. The workshop explored in depth the latest developments on the determination of the QCD coupling $\\alpha_s$ from 15 methods where high precision measurements are (or will be) available. Those include low-energy observables: (i) lattice QCD, (ii) pion decay factor, (iii) quarkonia and (iv) $\\tau$ decays, (v) soft parton-to-hadron fragmentation functions, as well as high-energy observables: (vi) global fits of parton distribution functions, (vii) hard parton-to-hadron fragmentation functions, (viii) jets in $e^\\pm$p DIS and $\\gamma$-p photoproduction, (ix) photon structure function in $\\gamma$-$\\gamma$, (x) event shapes and (xi) jet cross sections in $e^+e^-$ collisions, (xii) W boson and (xiii) Z boson decays, and (xiv) jets and (xv) top-quark cross sections in proton-(anti)proton collisions. The current status of the theoretical and experimental uncertainties associated to each extraction method, the improvements expected from LHC data in the coming years, and future perspectives achievable in $e^+e^-$ collisions at the Future Circular Collider (FCC-ee) with $\\cal{O}$(1--100 ab$^{-1}$) integrated luminosities yielding 10$^{12}$ Z bosons and jets, and 10$^{8}$ W bosons and $\\tau$ leptons, are thoroughly reviewed. The current uncertainty of the (preliminary) 2015 strong coupling world-average value, $\\alpha_s(m_Z)$ = 0.1177 $\\pm$ 0.0013, is about 1\\%. Some participants believed this may be reduced by a factor of three in the near future by including novel high-precision observables, although this opinion was not universally shared. At the FCC-ee facility, a factor of ten reduction in the $\\alpha_s$ uncertainty should be possible, mostly thanks to the huge Z and W data samples available.

  19. Convulxin binds to native, human glycoprotein Ib alpha.

    Science.gov (United States)

    Kanaji, Sachiko; Kanaji, Taisuke; Furihata, Kenichi; Kato, Kazunobu; Ware, Jerry L; Kunicki, Thomas J

    2003-10-10

    Convulxin (CVX), a C-type snake protein from Crotalus durissus terrificus venom, is the quintessential agonist for studies of the collagen receptor, glycoprotein VI (GPVI) and its role in platelet adhesion to collagens. In this study, CVX, purified from venom, behaves as expected, i.e. it binds to platelet GPVI and recombinant human GPVI, induces platelet aggregation and platelet prothrombinase activity, and binds uniquely to GPVI in ligand blots of SDS-denatured proteins. Nonetheless, we find that CVX has a dual specificity for both GPVI and native but not denatured human GPIb alpha. First, CVX binds to human GPIb alpha expressed on the surface of CHO cells. Second, CVX binds weakly to murine platelet GPIb alpha but more strongly to human platelet GPIb alpha, as evidenced by comparative binding to wild-type, GPVI(-/-), FcR gamma (-/-), and human GPIb transgenic mice. Third, the binding of CVX to human GPIb alpha is inhibited by soluble, recombinant human GPVI. Fourth, CVX binding to GPIb alpha is disrupted by phenylalanine substitutions at GPIb alpha tyrosine-276, tyrosine-278, and tyrosine-279, which also disrupts von Willebrand factor and alpha-thrombin binding to GPIb alpha. Fifth, CVX binding to GPIb alpha on Chinese hamster ovary cell transfectants is inhibited by function-blocking murine monoclonal anti-GPIb alpha antibodies. Lastly, CVX fails to bind to denatured GPIb alpha in detergent extracts of platelets. Three separate preparations of CVX (two purified by the authors; one obtained commercially) produced equivalent results. These results indicate that CVX exhibits dual specificity for both native GPIb alpha and GPVI. Furthermore, the binding site on GPIb alpha for CVX may be close to that for von Willebrand factor. Therefore, a contribution of GPIb alpha to CVX-induced platelet responses needs to be carefully re-evaluated.

  20. Fasting induces basolateral uptake transporters of the SLC family in the liver via HNF4alpha and PGC1alpha.

    Science.gov (United States)

    Dietrich, Christoph G; Martin, Ina V; Porn, Anne C; Voigt, Sebastian; Gartung, Carsten; Trautwein, Christian; Geier, Andreas

    2007-09-01

    Fasting induces numerous adaptive changes in metabolism by several central signaling pathways, the most important represented by the HNF4alpha/PGC-1alpha-pathway. Because HNF4alpha has been identified as central regulator of basolateral bile acid transporters and a previous study reports increased basolateral bile acid uptake into the liver during fasting, we hypothesized that HNF4alpha is involved in fasting-induced bile acid uptake via upregulation of basolateral bile acid transporters. In rats, mRNA of Ntcp, Oatp1, and Oatp2 were significantly increased after 48 h of fasting. Protein expression as determined by Western blot showed significant increases for all three transporters 72 h after the onset of fasting. Whereas binding activity of HNF1alpha in electrophoretic mobility shift assays remained unchanged, HNF4alpha binding activity to the Ntcp promoter was increased significantly. In line with this result, we found significantly increased mRNA expression of HNF4alpha and PGC-1alpha. Functional studies in HepG2 cells revealed an increased endogenous NTCP mRNA expression upon cotransfection with either HNF4alpha, PGC-1alpha, or a combination of both. We conclude that upregulation of the basolateral bile acid transporters Ntcp, Oatp1, and Oatp2 in fasted rats is mediated via the HNF4alpha/PGC-1alpha pathway.