{beta}-Ray angular distribution from purely nuclear spin aligned {sup 20}F

Energy Technology Data Exchange (ETDEWEB)

Nagatomo, T., E-mail: nagatomo@riken.jp [RIKEN Nishina Center (Japan); Matsuta, K. [Osaka University (Japan); Minamisono, K. [NSCL/MSU (United States); Sumikama, T. [Tokyo University of Science (Japan); Mihara, M. [Osaka University (Japan); Ozawa, A.; Tagishi, Y. [University of Tsukuba (Japan); Ogura, M.; Matsumiya, R.; Fukuda, M. [Osaka University (Japan); Yamaguchi, M.; Yasuno, T.; Ohta, H.; Hashizume, Y. [University of Tsukuba (Japan); Fujiwara, H. [Osaka University (Japan); Chiba, A. [University of Tsukuba (Japan); Minamisono, T. [Fukui University of Technology (Japan)

2007-11-15

The alignment correlation term in the {beta}-ray angular distribution from purely nuclear spin aligned {sup 20}F has been measured to test the G-parity conservation law which is one of the fundamental symmetries in the weak nucleon current. We utilized the hyperfine interaction of {sup 20}F in an MgF{sub 2} single crystal and successfully created the pure alignment from the polarization by means of the spin manipulation technique based on the {beta}-NMR method.

Influences of Sr-90 beta-ray irradiation on electrical characteristics of carbon nanoparticles

Energy Technology Data Exchange (ETDEWEB)

Kasani, H. [Department of Physics, University of Mohaghegh Ardabili, Ardabil (Iran, Islamic Republic of); Taghi Ahmadi, M., E-mail: ahmadi1351@gmail.com [Nano-Technology Research Center, Nano-Electronic Group, Physics Department, Urmia University, 57147 Urmia (Iran, Islamic Republic of); Department of Electronics and Computer Engineering, Faculty of Electrical Engineering, Universiti Teknologi Malaysia, 81310 UTM Johor Bahru, Johor (Malaysia); Khoda-bakhsh, R., E-mail: r.khodabakhsh16@gmail.com [Department of Physics, Faculty of Sciences, Urmia University, Urmia (Iran, Islamic Republic of); RezaeiOchbelagh, D. [Departments of Nuclear Engineering and Physics, Amirkabir University of Technology, Tehran (Iran, Islamic Republic of); Ismail, Razali [Department of Electronics and Computer Engineering, Faculty of Electrical Engineering, Universiti Teknologi Malaysia, 81310 UTM Johor Bahru, Johor (Malaysia)

2016-03-28

This work is concerned with the low cost fabrication of carbon nanoparticles (CNPs), and its application to beta ray detection. The structural and morphological properties of the CNPs were obtained by spectral and microscopy techniques. A system based on CNPs application in the metal-semiconductor-metal (MSM) junction platform, which acts as a beta-ray (β-ray) sensor, is fabricated. The prototype is characterised by modelling, Monte Carlo simulation, and electrical investigations. Changes to the electrical behaviour of the proposed MSM system due to β-ray irradiation are validated by experimental results in both Ohmic and non-Ohmic (Schottky) contacts. The simulation was performed using the MCNPX code, which showed that most of the β-ray energies are deposited into CNPs and electrodes. However, in the Ohmic contact, because the β-ray is induced, the current of CNPs is decreased. The reduction of the current might be due to the change of the carrier properties by increasing the scattering of electrons. The current-density equation for electrons was employed for understanding the effects of β-ray in Ohmic contact of CNPs. On the contrary, in the Schottky contact case, CNPs current was increased with constant voltage when biased by β-ray irradiation. In this paper, the electron–hole generation using β-rays is dominant when compared to other significant effects of radiation exposure on semiconducting CNP-based Schottky contact. Hence, the current increment of CNPs can be justified by electron–hole generation in the depletion region.

A semiconductor beta ray spectrometer

International Nuclear Information System (INIS)

Bom, V.R.

1987-01-01

Measurement of energy spectra of beta particles emitted from nuclei in beta-decay processes provides information concerning the mass difference of these nuclei between initial and final state. Moreover, experimental beta spectra yield information on the feeding of the levels in the daughter nucleus. Such data are valuable in the construction and checking of the level schemes. This thesis describes the design, construction, testing and usage of a detector for the accurate measurement of the mentioned spectra. In ch. 2 the design and construction of the beta spectrometer, which uses a hyper-pure germanium crystal for energy determination, is described. A simple wire chamber is used to discriminate beta particles from gamma radiation. Disadvantages arise from the large amounts of scattered beta particles deforming the continua. A method is described to minimize the scattering. In ch. 3 some theoretical aspects of data analysis are described and the results of Monte-Carlo simulations of the summation of annihilation radiation are compared with experiments. Ch. 4 comprises the results of the measurements of the beta decay energies of 103-108 In. 87 refs.; 34 figs.; 7 tabs

Characteristic tests of ionization chamber and GM counter survey meters for beta-rays, (2)

International Nuclear Information System (INIS)

Suga, Shin-ichi; Bingo, Kazuyoshi; Kajimoto, Yoichi

1979-03-01

To estimate a beta-ray absorbed dose rate of contaminated skin, measurements were done twice by a survey meter without and with a filter, keeping the distance from the contaminated skin surface to the survey meter at 10 mm. The absorbed dose rate was obtained multiplying a net reading (equals a reading of survey meter's indicator measured without the filter minus that measured with the filter) by a multiplying factor. Calibrations were made with reference plane sources of natural uranium, 198 Au and 204 Tl, varying their area. The five types of ionization chamber survey meters had nearly same multiplying factors when the diameter of source was larger than the diameter of the chamber cylinder. Estimation of the absorbed doses due to beta-emitting nuclides was possible when the measured value without filter was larger by 20% or more than that of with filter. In the case of small sources, the multiplying factor varied significantly with area of the source. The multiplying factors agreed within +-30% in the respective types i.e. manufacturers and in maximum beta-ray energies from 0.7 up to 2.5 MeV. In the source to detector distance of 1 cm +-0.2 cm, the multiplying factor varied within +-20%. The multiplying factor of a GM counter survey meter varied with beta-ray energy, the multiplying factor for uranium was 1/3 that of 204 Tl. (author)

Calibration of TLD cards to beta ray spectra of 32P

International Nuclear Information System (INIS)

Ben-Shachar, B.; German, U.; Naim, E.

1994-01-01

The results of the evaluation of TLD chips are received in nC, and we need to transform these values to mGy, in order to obtain the penetrating and the non-penetrating dose. The calibration factors were determined experimentally by irradiation the TLD chips with an uranium source. Beta rays having other spectra can cause incorrect values when estimating the non-penetrating dose. If the spectrum of the beta source is known, a specific evaluation of the calibration factor can be performed. In this report, the estimation of the calibration factor for a 32 P source is presented. LiF:Ti,Mg TLD cards were irradiated calibrated source of 90 Sr/ 90 Y and 204 Tl and non-calibrated source of 32 P, in order to find the beta correction factor for the spectrum of 32 P. Calculations of the beta correction factor were performed too, by applying the Loevinger equations to the geometry of the TLD chips used in our routine measurements. The calculated values of the beta correction factors are lower than the experimental ones. When comparing the ratios, between the beta factors of 32 P and 90 Sr/ 90 Y received from the experiments and from the calculation, we found them to be constant up to ±5%. (authors) 15 refs, 2 figs, 6 tabs

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)

Comparisons of experimental beta-ray spectra important to decay heat predictions with ENSDF [Evaluated Nuclear Structure Data File] evaluations

International Nuclear Information System (INIS)

Dickens, J.K.

1990-03-01

Graphical comparisons of recently obtained experimental beta-ray spectra with predicted beta-ray spectra based on the Evaluated Nuclear Structure Data File are exhibited for 77 fission products having masses 79--99 and 130--146 and lifetimes between 0.17 and 23650 sec. The comparisons range from very poor to excellent. For beta decay of 47 nuclides, estimates are made of ground-state transition intensities. For 14 cases the value in ENSDF gives results in very good agreement with the experimental data. 12 refs., 77 figs., 1 tab

In-trap decay spectroscopy for {beta}{beta} decays

Energy Technology Data Exchange (ETDEWEB)

Brunner, Thomas

2011-01-18

The presented work describes the implementation of a new technique to measure electron-capture (EC) branching ratios (BRs) of intermediate nuclei in {beta}{beta} decays. This technique has been developed at TRIUMF in Vancouver, Canada. It facilitates one of TRIUMF's Ion Traps for Atomic and Nuclear science (TITAN), the Electron Beam Ion Trap (EBIT) that is used as a spectroscopy Penning trap. Radioactive ions, produced at the radioactive isotope facility ISAC, are injected and stored in the spectroscopy Penning trap while their decays are observed. A key feature of this technique is the use of a strong magnetic field, required for trapping. It radially confines electrons from {beta} decays along the trap axis while X-rays, following an EC, are emitted isotropically. This provides spatial separation of X-ray and {beta} detection with almost no {beta}-induced background at the X-ray detector, allowing weak EC branches to be measured. Furthermore, the combination of several traps allows one to isobarically clean the sample prior to the in-trap decay spectroscopy measurement. This technique has been developed to measure ECBRs of transition nuclei in {beta}{beta} decays. Detailed knowledge of these electron capture branches is crucial for a better understanding of the underlying nuclear physics in {beta}{beta} decays. These branches are typically of the order of 10{sup -5} and therefore difficult to measure. Conventional measurements suffer from isobaric contamination and a dominating {beta} background at theX-ray detector. Additionally, X-rays are attenuated by the material where the radioactive sample is implanted. To overcome these limitations, the technique of in-trap decay spectroscopy has been developed. In this work, the EBIT was connected to the TITAN beam line and has been commissioned. Using the developed beam diagnostics, ions were injected into the Penning trap and systematic studies on injection and storage optimization were performed. Furthermore, Ge

Effect on pancreatic beta cells and nerve cells by low let x-ray

Energy Technology Data Exchange (ETDEWEB)

Park, Kwang Hun [Dept. of Nuclear Medicine, Kyungbuk National University Hospital, Daegu (Korea, Republic of); Kim, Kgu Hwan [Dept. of Radiological Technology, Daegu health College, Daegu (Korea, Republic of)

2014-03-15

Cultured pancreatic beta cells and nerve cells, it is given normal condition of 10% FBS (fetal bovine serum), 11.1 mM glucose and hyperglycemia condition of 1% FBS, 30 mM glucose. For low LET X-ray irradiated with 0.5 Gy/hr dose-rate(total dose: 0.5 to 5 Gy). Survival rates were measured by MTT assay. When non irradiated, differentiated in the pancreatic beta cells experiment is hyperglycemia conditions survival rate compared to normal conditions survival rate seemed a small reduction. However increasing the total dose of X-ray, the survival rate of normal conditions decreased slightly compared to the survival rate of hyperglycemia conditions, the synergistic effect was drastically reduced. When non irradiated, undifferentiated in the nerve cells experiment is hyperglycemia conditions survival rate compared to normal conditions survival rate seemed a large reduction. As the cumulative dose of X-ray normal conditions and hyperglycemia were all relatively rapid cell death. But the rate of decreased survivals by almost parallel to the reduction proceed and it didn't show synergistic effect.

Measurement of aerosol concentration with a beta-ray gage

International Nuclear Information System (INIS)

Auzac, G. d'; Dubillot, J.

1978-01-01

Because dusts in suspension are a dangerous polluting agent, several methods have been used to monitor their concentration. Among these, the beta-ray gage enjoys a privileged position. The authors describe such a gage and discuss the conditions to be observed for it to be capable of giving results comparable to those obtained with manual gravimetric methods. The satisfactory results obtained led to standardization of the method and a whole range of instruments based on this principle are employed in pollution supervising networks and for continuously monitoring industrial emissions [fr

Beta decay of the fission product 125Sb and a new complete evaluation of absolute gamma ray transition intensities

Science.gov (United States)

Rajput, M. U.; Ali, N.; Hussain, S.; Mujahid, S. A.; MacMahon, D.

2012-04-01

The radionuclide 125Sb is a long-lived fission product, which decays to 125Te by negative beta emission with a half-life of 1008 day. The beta decay is followed by the emission of several gamma radiations, ranging from low to medium energy, that can suitably be used for high-resolution detector calibrations, decay heat calculations and in many other applications. In this work, the beta decay of 125Sb has been studied in detail. The complete published experimental data of relative gamma ray intensities in the beta decay of the radionuclide 125Sb has been compiled. The consistency analysis was performed and discrepancies found at several gamma ray energies. Evaluation of the discrepant data was carried out using Normalized Residual and RAJEVAL methods. The decay scheme balance was carried out using beta branching ratios, internal conversion coefficients, populating and depopulating gamma transitions to 125Te levels. The work has resulted in the consistent conversion factor equal to 29.59(13) %, and determined a new evaluated set of the absolute gamma ray emission probabilities. The work has also shown 22.99% of the delayed intensity fraction as outgoing from the 58 d isomeric 144 keV energy level and 77.01% of the prompt intensity fraction reaching to the ground state from the other excited states. The results are discussed and compared with previous evaluations. The present work includes additional experimental data sets which were not included in the previous evaluations. A new set of recommended relative and absolute gamma ray emission probabilities is presented.

Beta decay of the fission product 125Sb and a new complete evaluation of absolute gamma ray transition intensities

International Nuclear Information System (INIS)

Rajput, M.U.; Ali, N.; Hussain, S.; Mujahid, S.A.; MacMahon, D.

2012-01-01

The radionuclide 125 Sb is a long-lived fission product, which decays to 125 Te by negative beta emission with a half-life of 1008 day. The beta decay is followed by the emission of several gamma radiations, ranging from low to medium energy, that can suitably be used for high-resolution detector calibrations, decay heat calculations and in many other applications. In this work, the beta decay of 125 Sb has been studied in detail. The complete published experimental data of relative gamma ray intensities in the beta decay of the radionuclide 125 Sb has been compiled. The consistency analysis was performed and discrepancies found at several gamma ray energies. Evaluation of the discrepant data was carried out using Normalized Residual and RAJEVAL methods. The decay scheme balance was carried out using beta branching ratios, internal conversion coefficients, populating and depopulating gamma transitions to 125 Te levels. The work has resulted in the consistent conversion factor equal to 29.59(13) %, and determined a new evaluated set of the absolute gamma ray emission probabilities. The work has also shown 22.99% of the delayed intensity fraction as outgoing from the 58 d isomeric 144 keV energy level and 77.01% of the prompt intensity fraction reaching to the ground state from the other excited states. The results are discussed and compared with previous evaluations. The present work includes additional experimental data sets which were not included in the previous evaluations. A new set of recommended relative and absolute gamma ray emission probabilities is presented.

Gallium Arsenide detectors for X-ray and electron (beta particle) spectroscopy

Energy Technology Data Exchange (ETDEWEB)

Lioliou, G.; Barnett, A.M.

2016-11-11

Results characterizing GaAs p{sup +}-i-n{sup +} mesa photodiodes with a 10 µm i layer for their spectral response under illumination of X-rays and beta particles are presented. A total of 22 devices, having diameters of 200 µm and 400 µm, were electrically characterized at room temperature. All devices showed comparable characteristics with a measured leakage current ranging from 4 nA/cm{sup 2} to 67 nA/cm{sup 2} at an internal electric field of 50 kV/cm. Their unintentionally doped i layers were found to be almost fully depleted at 0 V due to their low doping density. {sup 55}Fe X-ray spectra were obtained using one 200 µm diameter device and one 400 µm diameter device. The best energy resolution (FWHM at 5.9 keV) achieved was 625 eV using the 200 µm and 740 eV using the 400 µm diameter device, respectively. Noise analysis showed that the limiting factor for the energy resolution of the system was the dielectric noise; if this noise was eliminated by better design of the front end of the readout electronics, the achievable resolution would be 250 eV. {sup 63}Ni beta particle spectra obtained using the 200 µm diameter device showed the potential utility of these detectors for electron and beta particle detection. The development of semiconductor electron spectrometers is important particularly for space plasma physics; such devices may find use in future space missions to study the plasma environment of Jupiter and Europa and the predicted electron impact excitation of water vapor plumes from Europa hypothesized as a result of recent Hubble Space Telescope (HST) UV observations.

Gallium Arsenide detectors for X-ray and electron (beta particle) spectroscopy

Science.gov (United States)

Lioliou, G.; Barnett, A. M.

2016-11-01

Results characterizing GaAs p+-i-n+ mesa photodiodes with a 10 μm i layer for their spectral response under illumination of X-rays and beta particles are presented. A total of 22 devices, having diameters of 200 μm and 400 μm, were electrically characterized at room temperature. All devices showed comparable characteristics with a measured leakage current ranging from 4 nA/cm2 to 67 nA/cm2 at an internal electric field of 50 kV/cm. Their unintentionally doped i layers were found to be almost fully depleted at 0 V due to their low doping density. 55Fe X-ray spectra were obtained using one 200 μm diameter device and one 400 μm diameter device. The best energy resolution (FWHM at 5.9 keV) achieved was 625 eV using the 200 μm and 740 eV using the 400 μm diameter device, respectively. Noise analysis showed that the limiting factor for the energy resolution of the system was the dielectric noise; if this noise was eliminated by better design of the front end of the readout electronics, the achievable resolution would be 250 eV. 63Ni beta particle spectra obtained using the 200 μm diameter device showed the potential utility of these detectors for electron and beta particle detection. The development of semiconductor electron spectrometers is important particularly for space plasma physics; such devices may find use in future space missions to study the plasma environment of Jupiter and Europa and the predicted electron impact excitation of water vapor plumes from Europa hypothesized as a result of recent Hubble Space Telescope (HST) UV observations.

Evaluation of induced radioactivity in 10 MeV-Electron irradiated spices, (2); [beta]-ray counting

Energy Technology Data Exchange (ETDEWEB)

Katayama, Tadashi; Furuta, Masakazu; Shibata, Setsuko; Matsunami, Tadao; Ito, Norio; Mizohata, Akira; Toratani, Hirokazu (Osaka Prefectural Univ., Sakai (Japan). Research Inst. for Advanced Science and Technology); Takeda, Atsuhiko

1994-02-01

In order to check radioactivity of beta-emmitters produced by ([gamma], n) reactions which could occur at energies up to 10 MeV, black pepper, white pepper, red pepper, ginger and turmeric were irradiated with 10 MeV electron from a linear accelerator to a dose of 100 kGy. Beta-rays were counted using a 2[pi] gas flow counter and a liquid scintillation counter. Any induced radioactivity could not be detected in irradiated samples. When inorganic compounds containing the nuclides in the list were artificially added in the samples and were irradiated, the [beta]-activities were detected. From the amount of observed radioactivities of [beta]-emmitters produced in the compounds as photonuclear products, it is concluded that the induced radioactivity in natural samples by 10 MeV-electron irradiation were far smaller than natural radioactivity from [sup 40]K contained in the samples and, hence, its biological effects should be negligible. (author).

Counting efficiency for radionuclides decaying by beta and gamma-ray emission; Calculo de la eficiencia de recuento de nucleidos que experimentan desintegracion beta y desexcitacion gamma simple

Energy Technology Data Exchange (ETDEWEB)

Grau, A.; Garcia-Torano, E.

1988-07-01

In this paper, counting efficiency vs figure of merit for beta and gamma-ray emitters has been computed. It is assumed that the decay scheme has only a gamma level and the beta-ray emission may be coincident with the gamma-rays or the internal-conversion electrons. The radionuclides tabulated are: 20 {sub 0}, 20{sub p}, 28{sub A}l, 35{sub p}, 41{sub A}r, 42{sub K}, 47{sub S}e, 62{sub F}e, 66{sub C}u, 81{sub G}e, 86{sub B}b, 108{sub R}u, 112{sub p}d, 121{sub S}n(Ni), 122{sub I}n, 129{sub I}, 141{sub C}e 171{sub T}m, 194{sub O}s, 2O3{sub H}g, 205{sub H}g, 210{sub p}b, 225{sub R}a, 142{sub p}r, 151{sub S}m, 244{sub A}m(m). It has been assumed that the liquid is a toluene based scintillator solution in standard glass vials containing 10 cm''3. (Author) 8 refs.

The P1approximation in the transport of beta rays

International Nuclear Information System (INIS)

Legarda, F.; Idoeta, R.; Herranz, M.

1994-01-01

A validation test for the p1 approximation to the linear transport of electrons in planar geometry has been performed. The p1 approximation is shown to be a good option for the description of the transport of beta rays with endpoint energies between 400kev and 3.5Mev through aluminium foils . This approximation together with the use of only elastic interactions of electrons with atoms has found good agreement with experimental results . A calculation has been made of the fraction of transmitted electrons through foils, solving the transport equation for planar geometry in the p1 approximation and assuming that only elastic scattering processes take place. The boundary condition at the entrance of the foil was a collimated beta source, while at the end of the foil has been adopted a vaccum boundary condition.Sources considered are those for which experimental and calculated spectrum shapes are known to agree. The calculated fractional transmission through different absorber thicknesses is found to have an exponential shape . Besides this fact the attenuation coefficients found ,when compared with those empirically obtained, agree to within 5%. 1 fig.; 4 refs. (author)

Simultaneous beta and gamma spectroscopy

Science.gov (United States)

Farsoni, Abdollah T.; Hamby, David M.

2010-03-23

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

Spin-polarized x-ray emission of 3d transition-metal ions : A comparison via K alpha and K beta detection

NARCIS (Netherlands)

Wang, Xin; deGroot, F.M.F.; Cramer, SP

1997-01-01

This paper demonstrates that spin-polarized x-ray-excitation spectra can be obtained using K alpha emission as well as K beta lines. A spin-polarized analysis of K alpha x-ray emission and the excitation spectra by K alpha detection on a Ni compound is reported. A systematic analysis of the

Calculation of absorbed dose of anchorage-dependent cells from internal beta-rays irradiation

International Nuclear Information System (INIS)

Chen Jianwei; Huang Gang; Li Shijun

2001-01-01

Objective: To elicit the formula of internal dosimetry in anchorage-dependent cells by beta-emitting radionuclides from uniformly distributed volume sources. Methods: By means of the definition of absorbed dose and the MIRD (Medical International Radiation Dose) scheme the formula of internal dosimetry was reasonably deduced. Firstly, studying the systems of suspension culture cells. Then, taking account of the speciality of the systems of the anchorage-dependent cells and the directions of irradiation, the absorbed dose of anchorage -dependent cells was calculated by the accumulated radioactivity, beta-ray energy, and the volume of the cultured systems. Results: The formula of internal dosimetry of suspension culture cells and anchorage-dependent cells were achieved. At the same time, the formula of internal dosimetry of suspension culture cells was compared with that of MIRD and was confirmed accurate. Conclusion: The formula of internal dosimetry is concise, reliable and accurate

Beta rays and neutrinos

International Nuclear Information System (INIS)

Adams, S.F.

1992-01-01

It was over 30 years between the first observation of the enigmatic process of beta decay and the first postulation of the neutrino. It took a further 26 years until the first neutrino was detected and yet another 27 until the electroweak theory was confirmed by the discovery of W and Z particles. This article traces some of the puzzles and paradoxes associated with the history of the neutrino. (author)

Guidelines for the calibration of low energy photon sources at beta-ray brachytherapy sources

International Nuclear Information System (INIS)

2000-01-01

Kerma Rate. In this document the latter recommendation is adopted. Both of the quantities give the same numerical value for the source strength and differ only in the units they are expressed. The recommended dose calculation method is discussed further in the text. Sealed beta-ray sources for brachytherapy treatments have been in use for few decades already. An example is application of 90 Sr/ 90 Y planar sources for ophthalmic brachytherapy treatments. For these types of treatments, a precise dose distribution within the eye globe is needed. Modern diagnostic techniques permit the determination of all volumes of interest in the eye, i.e. tumor and critical structures such as optic disc and iris with a high precision. It is therefore of importance to optimize the treatment by limiting the dose to these critical structures. A relatively new and rapidly developing field in brachytherapy is the use of beta-ray sources for prevention of restenosis, i.e. re-closing of artery, following coronary and peripheral artery interventional procedures such as angioplasty, atherectomy and stent implantation. The dosimetry of beta-ray sources for therapeutic applications is particularly difficult due to the short distances involved, being at the millimeter range, and the high dose gradients at such short distances. Further difficulties are caused by the non-uniform distribution of activity in the source itself, causing a highly irregular dose distribution. The aim of this report is to recommend methods for calibration of low energy photon sources and beta-ray sources used in brachytherapy treatments and to propose suitable detectors for this purpose. Dose calculation methods are given both for the photon sources and beta-ray sources covered in this report. The present report has been developed in close collaboration with the ICRU Report Committee on this subject. The ICRU is planning to publish a report on the calibration of the type of sources discussed here. The present report is to

Initial response of an automatic dew-point hygrometer using [beta]-ray backscattering

Energy Technology Data Exchange (ETDEWEB)

Matsumoto, Shigeaki (Saitama Univ., Urawa (Japan). Faculty of Engineering)

1992-05-01

This paper describes the initial response of an automatic dew-point hygrometer using [beta]-ray backscattering. The response time after starting of measurement was evaluated in which the dew point measured with the hygrometer reached a value of 90 percent of the correct dew point in its response. Theoretical calculation was made by means of the loop transfer function of a control system employed in the hygrometer. The response times ranged from 1.7 min to 16 min corresponding to the dew point of 47.5degC and -6degC, respectively, and agreed well with experimental ones. (author).

Radiosensitivity of Prostate Cancer Cell Lines for Irradiation from Beta Particle-emitting Radionuclide ¹⁷⁷Lu Compared to Alpha Particles and Gamma Rays.

Science.gov (United States)

Elgqvist, Jörgen; Timmermand, Oskar Vilhelmsson; Larsson, Erik; Strand, Sven-Erik

2016-01-01

The purpose of the present study was to investigate the radiosensitivity of the prostate cancer cell lines LNCaP, DU145, and PC3 when irradiated with beta particles emitted from (177)Lu, and to compare the effect with irradiation using alpha particles or gamma rays. Cells were irradiated with beta particles emitted from (177)Lu, alpha particles from (241)Am, or gamma rays from (137)Cs. A non-specific polyclonal antibody was labeled with (177)Lu and used to irradiate cells in suspension with beta particles. A previously described in-house developed alpha-particle irradiator based on a (241)Am source was used to irradiate cells with alpha particles. External gamma-ray irradiation was achieved using a standard (137)Cs irradiator. Cells were irradiated to absorbed doses equal to 0, 0.5, 1, 2, 4, 6, 8, or 10 Gy. The absorbed doses were calculated as mean absorbed doses. For evaluation of cell survival, the tetrazolium-based WST-1 assay was used. After irradiation, WST-1 was added to the cell solutions, incubated, and then measured for level of absorbance at 450 nm, indicating the live and viable cells. LNCaP, DU145, and PC3 cell lines all had similar patterns of survival for the different radiation types. No significant difference in surviving fractions were observed between cells treated with beta-particle and gamma-ray irradiation, represented for example by the surviving fraction values (mean±SD) at 2, 6, and 10 Gy (SF2, SF6, and SF10) for DU145 after beta-particle irradiation: 0.700±0.090, 0.186±0.050 and 0.056±0.010, respectively. A strong radiosensitivity to alpha particles was observed, with SF2 values of 0.048±0.008, 0.018±0.006 and 0.015±0.005 for LNCaP, DU145, and PC3, respectively. The surviving fractions after irradiation using beta particles or gamma rays did not differ significantly at the absorbed dose levels and dose rates used. Irradiation using alpha particles led to a high level of cell killing. The results show that the beta-particle emitter

Preliminary soft x-ray studies of beta-SiC

Energy Technology Data Exchange (ETDEWEB)

Shek, M.L. [Brookhaven National Lab., Upton, NY (United States); Miyano, K.E.; Ederer, D.L. [Tulane Univ., New Orleans, LA (United States). Dept. of Physics; Dong, Q.Y.; Callcott, T.A. [Tennessee Univ., Knoxville, TN (United States). Dept. of Physics

1994-06-01

We have looked at beta-SiC with soft x-ray emission and photoemission spectroscopy. From the Si L{sub 23} and C K emissions, the Si s+d-like and C p partial density of states in the bulk valence band are identified, and compared with valence band photoemission. In addition to bulk electronic structural features, photoemission from a (3 {times} 2) Si-rich surface shows two surface-derived valence features at {approximately}{minus}2.6 and {approximately}{minus}1.6 eV relative to the Fermi level. The intensities of these valence features vary as those of surface Si 2p core level components shifted by {minus}0.5 eV and {minus}1.4 eV from the bulk-like SiC Si 2p core level. We have also used the Si L{sub 23} absorption edge as a probe of the unfilled states near the conduction, band minimum.

Microscopic beta and gamma data for decay-heat needs

International Nuclear Information System (INIS)

Dickens, J.K.

1983-01-01

Microscopic beta and gamma data for decay-heat needs are defined as absolute-intensity spectral distributions of beta and gamma rays following radioactive decay of radionuclides created by, or following, the fission process. Four well-known evaluated data files, namely the US ENDF/B-V, the UK UKFPDD-2, the French BDN (for fission products), and the Japanese JNDC Nuclear Data Library, are reviewed. Comments regarding the analyses of experimental data (particularly gamma-ray data) are given; the need for complete beta-ray spectral measurements is emphasized. Suggestions on goals for near-term future experimental measurements are presented. 34 references

On evaluated nuclear data for beta-delayed gamma rays following of special nuclear materials

Energy Technology Data Exchange (ETDEWEB)

Mencarini, Leonardo de H.; Caldeira, Alexandre D., E-mail: mencarini@ieav.cta.b, E-mail: alexdc@ieav.cta.b [Instituto de Estudos Avancados (IEAv/CTA), Sao Jose dos Campos, SP (Brazil)

2011-07-01

In this paper, a new type of information available in ENDF is discussed. During a consistency check of the evaluated nuclear data library ENDF/B-VII.0 performed at the Nuclear Data Subdivision of the Institute for Advanced Studies, the size of the files for some materials drew the attention of one of the authors. Almost 94 % of all available information for these special nuclear materials is used to represent the beta-delayed gamma rays following fission. This is the first time this information is included in an ENDF version. (author)

On evaluated nuclear data for beta-delayed gamma rays following of special nuclear materials

International Nuclear Information System (INIS)

Mencarini, Leonardo de H.; Caldeira, Alexandre D.

2011-01-01

In this paper, a new type of information available in ENDF is discussed. During a consistency check of the evaluated nuclear data library ENDF/B-VII.0 performed at the Nuclear Data Subdivision of the Institute for Advanced Studies, the size of the files for some materials drew the attention of one of the authors. Almost 94 % of all available information for these special nuclear materials is used to represent the beta-delayed gamma rays following fission. This is the first time this information is included in an ENDF version. (author)

Dose-response relationship for the induction of structural chromosome aberrations in human spermatozoa after in vitro exposure ti tritium. beta. -rays

Energy Technology Data Exchange (ETDEWEB)

Kamiguchi, Yujiroh; Tateno, Hiroyuki; Mikamo, Kazuya (Asahikawa Medical College (Japan). Department of Biological Sciences)

1990-02-01

THe effects of tritium (HTO) {beta}-rays on human sperm chromosomes were studied using our interspecific in vitro fertilization system between human spermatozoa and zona-free hamster oocytes. Semen samples were treated with media containing 1.53-24.3 mCi/ml HTO for about 80 min. 1290 spermatozoa from the controls and 1842 spermatozoa from the irradiated groups were karyotyped. The incidence of spermatozoa with structural chromosome aberrations increased linearly with increasing dosage. Breakage-type aberrations occurred far more frequently than exchange-type. Chromosome-type aberrations appeared far more frequently than chromatid-ype. All of these types of aberrations showed linear dose-dependent increases. The RBE valus of HTO {beta}-rays relative to X-rays were calculated for the above-mentioned 5 indices, respectively. Their RBE values franged from 1.89 to 3.00 when the absorbed dose was estimated to be the minimum, whereas the values ranged between 1.04 and 1.65 when the absorbed dose was estimated to be the maximum. (author). 15 refs.; 3 figs.; 4 tabs.

Angular dependence of Ll, L $\\alpha$ , L $\\beta$ and L $\\gamma$ X-ray differential and fluorescence cross-sections for Er, Ta, W, Au, Hg and Tl

CERN Document Server

Demir, L; Kurucu, Y; Karabulut, A; Sahin, Y; 10.1016/S0969-806X(02)00501-7

2003-01-01

Ll, L alpha , L beta and L gamma X-ray differential cross-sections, fluorescence cross-sections and L/sub i/-subshell ( sigma /sub L1/, sigma /sub L2/, and sigma /sub L3/) fluorescence cross-sections were measured for Er, Ta, W, Au, Hg, and Tl at an excitation energy of 59.6 keV using a Si(Li) detector. The differential cross-sections for these elements have been measured at different angles varying from 54 degrees to 153 degrees at intervals of 9 degrees . The Ll and L alpha groups in the L X-ray lines are found to be spatially anisotropic, while those in the L beta and L gamma peaks are isotropic. Experimental and theoretical values of L X-ray fluorescence cross- sections and L/sub i/-subshell X-ray fluorescence cross-sections were compared. (20 refs).

A new method for characterizing beta-ray ophthalmic applicator sources

International Nuclear Information System (INIS)

Sayeg, J.A.; Gregory, R.C.

1991-01-01

A technique is described which enables one to obtain detailed dose characteristics of 90Sr beta-ray ophthalmic applicators. A radiochromic radiation detector which is a solid-state solution of hexahydroxyethyl pararosaniline cyanide in a nylon polymer (i.e., thin foil), has been used to determine the surface dose rate and dose distribution of these sources. The detectors are rugged, easily handled, have an equivalent response (optical density per unit absorbed dose) to photons and electrons, and produce high-resolution images. They have been found useful for this application due to the high surface dose rates [0.10-1.0 Gy (H2O)/s] and their low sensitivity (approximately 10(4) Gy for an optical density of 1.0). The foils have been evaluated on a He-Ne scanning laser densitometer with a resolution of 0.3 mum. Comparison with NIST (formerly NBS) extrapolation ionization chamber measurements indicates surface dose-rate agreement within 6%. Spectral dosimetric characteristics are presented and discussed

Design and characteristics of beta-excited X-ray sources; Caracteristiques des sources de rayons X excitees par des particules beta; Konstruktsiya i kharakteristiki beta-vozbuzhdennykh istochnikov rentgenovskikh luchej; Diseno y caracteristicas de las fuentes de rayos X excitadas por particulas beta

Energy Technology Data Exchange (ETDEWEB)

Filosofo, I; Reiffel, L; Stone, C A; Voyvodic, L [Physics Division, Armour Research Foundation, Chicago, IL (United States)

1962-01-15

The paper reports on recent work on beta-excited X-ray sources. Results of detailed experimental investigation on the X-rays produced by the fission products Pm{sup 147}, Kr{sup 85} and Sr{sup 90} are described. X-ray yields and spectral distributions have been studied for target materials ranging from copper to uranium and in a variety of source-target geometries (transmission target, reflection target, sandwich target, intimate source-target mixtures). To interpret the experimental results, an analytical treatment of the processes involved in X-ray production by beta particles has been developed and is outlined. By taking into account bremsstrahlung, K-shell ionization, and fluorescent X-ray excitation, a convenient mathematical formulation may be derived for photon spectra and yields as functions of maximum {beta}-energy, target thickness and source configuration. The agreement between calculated and experimentally determined yields is excellent and confirms the merit of the analysis. It thus becomes possible to optimize the design of isotopic X-ray sources for specific applications. Kr{sup 85} and Pm{sup 147} prototype sources have been designed and 'their performance in thickness and composition-analysis measurements is discussed. A high level Pm{sup 147} source for industrial radiography has also been designed and its performance, along with the utility of image intensifiers to extend its applicability, is considered. Finally, a general review of potentialities, advantages and limitations of isotopic X-ray sources is given. (author) [French] Le memoire rend compte des recents travaux sur les sources de rayons X excitees par des particules beta. Il donne les resultats d'une etude experimentale detaillee sur les rayons X emis par les produits de fission {sup 147}Pm, {sup 85}Kr et {sup 90}Sr. Les auteurs ont etudie l'emission et la distribution spectrale des rayons X pour des cibles allant du cuivre a l'uranium, et ce dans plusieurs geometries source

Intergrown new zeolite beta polymorphs with interconnected 12-ring channels solved by combining electron crystallography and single-crystal X-ray diffraction

KAUST Repository

Yu, Zhengbao

2012-10-09

Two new polymorphs of zeolite beta, denoted as SU-78A and SU-78B, were synthesized by employing dicyclohexylammonium hydroxides as organic structure-directing agents. The structure was solved by combining transmission electron microscopy and single-crystal X-ray diffraction. SU-78 is an intergrowth of SU-78A and SU-78B and contains interconnected 12-ring channels in three directions. The two polymorphs are built from the same building layer, similar to that for the zeolite beta family. The layer stacking in SU-78, however, is different from those in zeolite beta polymorph A, B, and C, showing new zeolite framework topologies. SU-78 is thermally stable up to 600 °C. © 2012 American Chemical Society.

Beta-decay of {sup 56}Cu

Energy Technology Data Exchange (ETDEWEB)

Ramdhane, M.; Baumann, P.; Knipper, A.; Walter, G. [Institute de Recherches Subatomiques, 67 - Strasbourg (France); Janas, Z.; Plochocki, A. [Warsaw Univ. (Poland). Inst. of Experimental Physics; Aeystoe, J.; Dendooven, P.; Jokinen, A.; Oinonen, M.; Pentilae, H. [Jyvaeskylae Univ. (Finland); Liu, W.; Grawe, H.; Hu, Z.; Kirchner, R.; Klepper, O.; Roeckl, E. [Gesellschaft fuer Schwerionenforschung mbH, Darmstadt (Germany); Gorska, M. [Warsaw Univ. (Poland). Inst. of Experimental Physics]|[Gesellschaft fuer Schwerionenforschung mbH, Darmstadt (Germany); Fujita, Y. [Osaka Univ. (Japan); Brown, B.A. [Michigan State Univ., East Lansing, MI (United States)

1998-02-01

By measuring positrons and {beta}-delayed {gamma}-rays emitted from mass-separated sources, the decay of {sup 56}Cu(4{sup +},T{sub z}=-1,T=1) to states in the doubly-magic nucleus {sup 56}Ni was studied for the first time. The half-life of {sup 56}Cu was measured to be 78(15) ms, and four {beta}-delayed {gamma}-rays were assigned to its decay. The resulting experimental data on Fermi and Gamow-Teller strength are compared with shell-model predictions. (orig.)

Research Applications of Beta-Particle Techniques: Back-Scattering and X-Ray Excitation; Applications de l'irradiation beta dans la recherche: retrodiffusion et excitation de rayons X; Primenenie metodov beta-chastits v issledovatel'skoj rabote: obratnoe rasseyanie i vozbuzhdenie rentgenovskikh luchej; Aplicacion de la irradiacion beta en la investigacion: retrodispersion y excitacion de rayos X

Energy Technology Data Exchange (ETDEWEB)

Mueller, R H [Los Alamos Scientific Laboratory, University of California, Los Alamos, NM (United States)

1962-01-15

Studies in this Laboratory during the past seven years have established precise relationships for the back-scattering of beta-particles and these methods have been supplemented by techniques using isotope-excited X-rays. Such X-ray techniques have received wide attention and in many cases have revolutionized industrial gauging practices. This report is concerned with applications to precise absorptiometry, thickness of films, the identification and quantitative estimation of substances by absorption-edge measurements, and to paper chromatography. In the latter, chromatograms can be evaluated by beta-absorption, by X-ray absorption, or by excitation of X-rays in the various zones by beta-bombardment. These alternative approaches are compared and evaluated. Some microchemical techniques have been examined, and, either by beta-absorption or by beta-excitation of X-rays, small amounts of substances can be identified and determined. The lower limits of detection are not as small as one can achieve by tracer techniques, but there are numerous advantages, the primary one being that one deals with sealed sources from which contamination is virtually impossible. For all these phenomena precise equations have been developed from the data - some empirical, and others substantially fundamental. It is interesting that these equations accurately predict optimum source parameters as established by other investigators both in the United States and abroad. It is believed that these techniques confirm the opinion that radioactive isotopes have tremendous scientific and technical promise. As far as X-ray sources are concerned, it may be said that everything in X-ray technology, other than crystal-structure elucidation, can be done more simply by these means. With multi-curie sources, even the latter may eventually be possible. (author) [French] Les etudes qui se poursuivent depuis sept ans au Laboratoire de Los Alamos ont permis d'etablir des rapports precis pour la retrodiffusion

Beta decay of Cu-56

NARCIS (Netherlands)

Borcea, R; Aysto, J; Caurier, E; Dendooven, P; Doring, J; Gierlik, M; Gorska, M; Grawe, H; Hellstrom, M; Janas, Z; Jokinen, A; Karny, M; Kirchner, R; La Commara, M; Langanke, K; Martinez-Pinedo, G; Mayet, P; Nieminen, A; Nowacki, F; Penttila, H; Plochocki, A; Rejmund, M; Roeckl, E; Schlegel, C; Schmidt, K; Schwengner, R; Sawicka, M

2001-01-01

The proton-rich isotope Cu-56 was produced at the GSI On-Line Mass Separator by means of the Si-28(S-32, p3n) fusion-evaporation reaction. Its beta -decay properties were studied by detecting beta -delayed gamma rays and protons. A half-Life of 93 +/- 3 ms was determined for Cu-56. Compared to the

Multiple Beta Spectrum Analysis Method Based on Spectrum Fitting

Energy Technology Data Exchange (ETDEWEB)

Lee, Uk Jae; Jung, Yun Song; Kim, Hee Reyoung [UNIST, Ulsan (Korea, Republic of)

2016-05-15

When the sample of several mixed radioactive nuclides is measured, it is difficult to divide each nuclide due to the overlapping of spectrums. For this reason, simple mathematical analysis method for spectrum analysis of the mixed beta ray source has been studied. However, existing research was in need of more accurate spectral analysis method as it has a problem of accuracy. The study will describe the contents of the separation methods of the mixed beta ray source through the analysis of the beta spectrum slope based on the curve fitting to resolve the existing problem. The fitting methods including It was understood that sum of sine fitting method was the best one of such proposed methods as Fourier, polynomial, Gaussian and sum of sine to obtain equation for distribution of mixed beta spectrum. It was shown to be the most appropriate for the analysis of the spectrum with various ratios of mixed nuclides. It was thought that this method could be applied to rapid spectrum analysis of the mixed beta ray source.

Studies of. gamma. -ray irradiation effects on tris(. beta. -diketonato)iron(III) and cobalt(III) coordination compounds by means of Moessbauer spectroscopy and magnetic susceptibility measurements

Energy Technology Data Exchange (ETDEWEB)

Sakai, Y.; Endo, K.; Sano, H. (Tokyo Metropolitan Univ. (Japan). Faculty of Science)

1981-06-01

Both absorption Moessbauer spectroscopy and magnetic susceptibility measurements on tris(..beta..-diketonato)iron(III) and cobalt(III) compounds indicate that ligands which have phenyl group as a substituent are more stable to ..gamma..-ray radiolysis, in accordance with previous results of emission Moessbauer spectroscopic studies of /sup 57/Co-labelled tris (..beta..-diketonato)cobalt(III) compounds.

The application of {beta}-ray excitation fluorescence to the measurement of the thickness of deposits and to analysis; Applications de la fluorescence excitee au moyen des rayons {beta} a la mesure des epaisseurs des depots et a l'analyse

Energy Technology Data Exchange (ETDEWEB)

Martinelli, P [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires; Seibel, G [Institut de Recherches de la Siderurgie Francaise (IRSID), 78 - Saint-Germain-en-Laye (France)

1961-07-01

Principles of the method are first outlined and the instrumentation used is described. The different types of radiation detectors are subject of a detailed study. As a source of {beta}-radiation {sup 90}(Sr + Y) was used as well as {sup 147}Pm. Great care was taken to eliminate back-diffused electrons by deflection by a strong permanent magnet. The method was applied to the measurement of the thickness of deposits of Cr, Zn, Sn, Cd and Cu on iron as well as Zn, Cr, Ag and Au on copper and the results obtained are discussed. An attempt was made, to use {beta}-X-ray fluorescence for the analysis of minerals, iron ore and glass and for routine control of Si-Mn, Si-Ca, Fe-Mn and Fe-W. Finally the method of {beta}-X-ray fluorescence is compared with normal-X-ray fluorescence and possibilities of further development are cited. (author) [French] Les principes de la methode et l'instrumentation utilisee sont presentes. On decrit en particulier les detecteurs de rayonnement utilises. Comme source de rayonnement on utilise {sup 90}(Sr + Y) et {sup 147}Pm. Pour eliminer les electrons retrodiffuses on utilise un aimant permanent place sur le trajet du faisceau. La methode est appliquee a la mesure des epaisseurs des depots metalliques tels que le Cr, Zn, Sn, Cd et Cu sur fer et le Zn, Cr, Ag et Au sur cuivre. D'autre part, la fluorescence {beta}-X etait utilisee pour l'analyse des minerais et des verres et pour le controle des alliages Fe-Mn, Fe-W, Si-Mn, Si-Ca. Enfin, on passe a une comparaison entre la fluorescence {beta}-X et la fluorescence X normale et on discute les possibilites d'un developpement futur. (auteur)

Expression, purification, crystallization, and preliminary X-ray crystallographic analysis of OXA-17, an extended-spectrum {beta}-lactamase conferring severe antibiotic resistance

Energy Technology Data Exchange (ETDEWEB)

Lee, J. H., E-mail: msgjhlee@mju.ac.kr; Sohn, S. G., E-mail: sgsohn@mju.ac.kr; Jung, H. I., E-mail: jhinumber1@hanmail.net; An, Y. J., E-mail: anyj0120@hanmail.net; Lee, S. H., E-mail: sangheelee@mju.ac.kr [Myongji University, Drug Resistance Proteomics Laboratory, Department of Biological Sciences (Korea, Republic of)

2013-07-15

OXA-17, an extended-spectrum {beta}-lactamase (ESBL) conferring severe antibiotic resistance, hydrolytically inactivates {beta}-lactam antibiotics, inducing a lack of eradication of pathogenic bacteria by oxyimino {beta}-lactams and not helping hospital infection control. Thus, the enzyme is a potential target for developing antimicrobial agents against pathogens producing ESBLs. OXA-17 was purified and crystallized at 298 K. X-ray diffraction data from OXA-17 crystal have been collected to 1.85 A resolution using synchrotron radiation. The crystal of OXA-17 belongs to space group P2{sub 1}2{sub 1}2{sub 1}, with unit-cell parameters a = 48.37, b = 101.12, and c = 126.07 A. Analysis of the packing density shows that the asymmetric unit probably contains two molecules with a solvent content of 54.6%.

Rapid method of identification of {beta}-ray emitters and of {beta}-radioactive impurity dosage (1961); Methode rapide d'identification des emetteurs-{beta} et de dosage d'impuretes radioactives-{beta} (1961)

Energy Technology Data Exchange (ETDEWEB)

Le Gallic, Y; Legrand, J; Grinberg, B [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1961-07-01

We describe a simple method of radioactive analysis, which allows an accurate determination of maximal energies of {beta}-emitters, and detection and titration of radioactive impurities in radionuclides as well. The method described, which uses a plastic scintillator, is based on the fact that the curve obtained by plotting the number of pulses measured against the threshold is a straight line, in the case of pure {beta}-emitters. We then derive a simple relation between the data of this straight line and the maximal energy of the {beta}-spectrum of the radionuclide under consideration. (authors) [French] Description d'une methode simple d'analyse radioactive, permettant de determiner avec precision l'energie maximum des emetteurs-{beta}, ainsi que de deceler et de doser les impuretes radioactives dans un radionuclide. La technique decrite utilise un scintillateur plastique. On exploite le fait que la courbe du nombre d'impulsions mesurees, en fonction du seuil de discrimination, est une droite, pour un emetteur-{beta} pur. Une relation simple entre les caracteristiques de cette droite et l'energie maximum du spectre-{beta} du radionuclide, correspondant, a ete etablie. (auteurs)

Indirect radio-chemo-beta therapy: a targeted approach to increase biological efficiency of x-rays based on energy.

Science.gov (United States)

Oktaria, Sianne; Corde, Stéphanie; Lerch, Michael L F; Konstantinov, Konstantin; Rosenfeld, Anatoly B; Tehei, Moeava

2015-10-21

Despite the use of multimodal treatments incorporating surgery, chemotherapy and radiotherapy, local control of gliomas remains a major challenge. The potential of a new treatment approach called indirect radio-chemo-beta therapy using the synergy created by combining methotrexate (MTX) with bromodeoxyuridine (BrUdR) under optimum energy x-ray irradiation is assessed. 9L rat gliosarcoma cells pre-treated with 0.01 μM MTX and/or 10 μM BrUdR were irradiated in vitro with 50 kVp, 125 kVp, 250 kVp, 6 MV and 10 MV x-rays. The cytotoxicity was assessed using clonogenic survival as the radiobiological endpoint. The photon energy with maximum effect was determined using radiation sensitization enhancement factors at 10% clonogenic survival (SER10%). The cell cycle distribution was investigated using flow cytometric analysis with propidium iodide staining. Incorporation of BrUdR in the DNA was detected by the fluorescence of labelled anti-BrUdR antibodies. The radiation sensitization enhancement exhibits energy dependence with a maximum of 2.3 at 125 kVp for the combined drug treated cells. At this energy, the shape of the clonogenic survival curve of the pharmacological agents treated cells changes substantially. This change is interpreted as an increased lethality of the local radiation environment and is attributed to supplemented inhibition of DNA repair. Radiation induced chemo-beta therapy was demonstrated in vitro by the targeted activation of combined pharmacological agents with optimized energy tuning of x-ray beams on 9 L cells. Our results show that this is a highly effective form of chemo-radiation therapy.

Analytical investigation of energy spectrums of beta rays emitted from 90Sr and 204Tl radioisotopes

International Nuclear Information System (INIS)

Yalcin, S.

2011-01-01

The energy spectra of beta rays emitted from 90 Sr and 204 Tl radioisotopes were obtained by using a silicon surface barrier detector with a 1000 μm depleted layer and 50 mm 2 effective area. The detector response function is interpreted by making use of range distributions of mono-energetic electrons in matter and by assuming a linear energy loss along the range in the depleted layer of the detector. An analytical expression is given for pulse height distribution obtained in the surface barrier detector. A good agreement is observed between the experimental results and theoretical interpretation. (author)

Evidence for novel beta-sheet structures in Iowa mutant beta-amyloid fibrils.

Science.gov (United States)

Tycko, Robert; Sciarretta, Kimberly L; Orgel, Joseph P R O; Meredith, Stephen C

2009-07-07

Asp23-to-Asn mutation within the coding sequence of beta-amyloid, called the Iowa mutation, is associated with early onset, familial Alzheimer's disease and cerebral amyloid angiopathy, in which patients develop neuritic plaques and massive vascular deposition predominantly of the mutant peptide. We examined the mutant peptide, D23N-Abeta40, by electron microscopy, X-ray diffraction, and solid-state NMR spectroscopy. D23N-Abeta40 forms fibrils considerably faster than the wild-type peptide (k = 3.77 x 10(-3) min(-1) and 1.07 x 10(-4) min(-1) for D23N-Abeta40 and the wild-type peptide WT-Abeta40, respectively) and without a lag phase. Electron microscopy shows that D23N-Abeta40 forms fibrils with multiple morphologies. X-ray fiber diffraction shows a cross-beta pattern, with a sharp reflection at 4.7 A and a broad reflection at 9.4 A, which is notably smaller than the value for WT-Abeta40 fibrils (10.4 A). Solid-state NMR measurements indicate molecular level polymorphism of the fibrils, with only a minority of D23N-Abeta40 fibrils containing the in-register, parallel beta-sheet structure commonly found in WT-Abeta40 fibrils and most other amyloid fibrils. Antiparallel beta-sheet structures in the majority of fibrils are indicated by measurements of intermolecular distances through (13)C-(13)C and (15)N-(13)C dipole-dipole couplings. An intriguing possibility exists that there is a relationship between the aberrant structure of D23N-Abeta40 fibrils and the unusual vasculotropic clinical picture in these patients.

Development of beta reference radiations

International Nuclear Information System (INIS)

Wan Zhaoyong; Cai Shanyu; Li Yanbo; Yin Wei; Feng Jiamin; Sun Yuhua; Li Yongqiang

1997-09-01

A system of beta reference radiation has been developed, that is composed of 740 MBq 147 Pm beta source, 74 MBq and 740 MBq 90 Sr + 90 Y β sources, compensation filters, a source handling tool, a source jig, spacing bars, a shutter, a control unit and a beta dose meter calibration stand. For 740 MBq 147 Pm and 74 MBq 90 Sr + 90 Y beta reference radiations with compensation filters and 740 MBq 90 Sr + 90 Y beta reference radiation without compensation filter, at 20 cm, 30 cm and 30 cm distance separately; the residual energy of maximum is 0.14 MeV, 1.98 MeV and 2.18 MeV separately; the absorbed dose to tissue D (0.07) is 1.547 mGy/h (1996-05-20), 5.037 mGy/h (1996-05-10) and 93.57 mGy/h (1996-05-15) separately; the total uncertainty is 3.0%, 1.7% and 1.7% separately. For the first and the second beta reference radiation, the dose rate variability in the area of 18 cm diameter in the plane perpendicular to the beta-ray beam axis is within +-6% and +-3% separately. (3 refs., 2 tabs., 8 figs.)

Investigation of Deuterium Loaded Materials Subject to X-Ray Exposure

Science.gov (United States)

Benyo, Theresa L.; Steinetz, Bruce M.; Hendricks, Robert C.; Martin, Richard E.; Forsley, Lawrence P.; Daniels, Christopher C.; Chait, Arnon; Pines, Vladimir; Pines, Marianna; Penney, Nicholas;

Beta-structures in fibrous proteins.

Science.gov (United States)

Kajava, Andrey V; Squire, John M; Parry, David A D

2006-01-01

The beta-form of protein folding, one of the earliest protein structures to be defined, was originally observed in studies of silks. It was then seen in early studies of synthetic polypeptides and, of course, is now known to be present in a variety of guises as an essential component of globular protein structures. However, in the last decade or so it has become clear that the beta-conformation of chains is present not only in many of the amyloid structures associated with, for example, Alzheimer's Disease, but also in the prion structures associated with the spongiform encephalopathies. Furthermore, X-ray crystallography studies have revealed the high incidence of the beta-fibrous proteins among virulence factors of pathogenic bacteria and viruses. Here we describe the basic forms of the beta-fold, summarize the many different new forms of beta-structural fibrous arrangements that have been discovered, and review advances in structural studies of amyloid and prion fibrils. These and other issues are described in detail in later chapters.

Copper L X-ray spectra measured by a high resolution ion-induced X-ray spectrometer

Energy Technology Data Exchange (ETDEWEB)

Takahashi, Ryohei; Hamaguchi, Dai; Kageyama, Hiroyoshi [Kyoto Inst. of Tech. (Japan); and others

1997-03-01

High resolution L X-ray emission spectra of Cu have been measured by 0.75 MeV/u H, He, and F, 0.73 MeV/u Ar, 0.64 MeV/u Si, and 0.073 MeV/u Si ion impacts with a crystal spectrometer. The X-ray transition energies in the Cu target for L{iota}, L{eta}, L{alpha}{sub 1,2}, L{beta}{sub 1}, and L{beta}{sub 3,4} diagram lines induced by light ion impacts are determined, which are in good agreement with those given in the reference. The difference in L X-ray emission spectra produced by H, He, F, Si, and Ar ions are considered and the L{alpha}{sub 1,2} and L{beta}{sub 1} emission spectra are compared with the calculated ones based on the multiconfiguration Dirac-Fock method. (author)

Biodegradable films containing {alpha}-tocopherol/{beta}-cyclodextrin complex; Filmes biodegradaveis contendo {alpha}-tocoferol complexado em {beta}-ciclodextrina

Energy Technology Data Exchange (ETDEWEB)

Motta, Caroline; Martelli, Silvia M.; Soldi, Valdir, E-mail: vsoldi@qmc.ufsc.br [Lab. de Materiais Polimericos (POLIMAT), Dept. de Quimica, Universidade Federal de Santa Catarina, Florianopolis, SC (Brazil); Barreto, Pedro L.M. [Lab. de Reologia (REOLAB), Dept. de Ciencia e Tecnologia de Alimentos, Universidade Federal de Santa Catarina, Florianopolis, SC (Brazil)

2011-07-01

The growing environmental concern about pollution and the need to reduce dependence of plastic industry in relation to non-renewable resources has increased the interest of both researchers and industry in the use of biopolymers. In this work {beta}-cyclodextrin/{alpha}-tocopherol complexes were prepared and characterized. In order to obtain polymeric active biofilms, the {beta}-cyclodextrin/{alpha}-tocopherol complex was incorporated into a polymeric matrix of carboxymethylcellulose. The {beta}-cyclodextrin/{alpha}-tocopherol complex was characterized through of X-ray diffraction and thermogravimetric analysis. The physicochemical properties of the films incorporated with the complex were evaluated through mechanical and colorimetric analysis and moisture sorption isotherm. (author)

RBE of tritium beta rays for causes of death other than myeloid leukemia in male CBA/H mice

International Nuclear Information System (INIS)

Myers, D.K.; Jackson, J.S.; Dunford, D.W.

1991-05-01

Causes of death were examined for 5,206 male CBA/H mice which had previously been treated with tritiated water or with X rays at comparable doses and comparable dose rates. Data on induced myeloid leukemia had been examined in detail in a previous report. The purpose of the present study was to examine the relative biological effectiveness of tritium beta rays for causes of death other than mye-loid leukemia. However, no consistent values for the tritium relative biological effectiveness were obtained. The values were spread over a wide range for different endpoints and were generally less reliable than those for induction of myeloid leukemia. A surprising decrease in time to death of animals without tumours was observed in the irradiated groups of mice. This observation suggests that a detailed review of recent data on non-specific life shortening in irradiated animals and humans might be useful

The imaging pin detector - a simple and effective new imaging device for soft x-rays and soft beta emissions

International Nuclear Information System (INIS)

Bateman, J.E.

1984-01-01

The development of a new bidimensional imaging detector system for soft X and beta radiations is reported. Based on the detection of the differential induction signals on pickup electrodes placed around a point anode in a gas avalanche detector, the system described has achieved a spatial resolution of better than 1mm fwhm over a field of 30mm diameter while preserving excellent pulse height resolution. The present device offers considerable potential as a cheap and robust imaging system for applications in X-ray diffraction and autoradiography. (author)

Beta decay of 22O

International Nuclear Information System (INIS)

Hubert, F.; Dufour, J.P.; Moral, R. del; Fleury, A.; Jean, D.; Pravikoff, M.S.; Delagrange, H.; Geissel, H.; Schmidt, K.H.; Hanelt, E.

1989-01-01

The beta-gamma spectroscopic study of 22 O is presented. This nucleus, produced as a projectile-like fragment from the interaction of a 60 MeV/n 40 Ar beam with a Be target, has been separated by the LISE spectrometer. Several gamma rays from 22 O decay have been observed, from which a half-life of (2.25±0.15) s has been determined. Accurate excitation energies have been deduced for several states in 22 F. A partial beta decay scheme of 22 O has been established. Experimental results have been compared with shell model calculations. (orig.)

Detection of gamma rays using scintillation optical fibers

International Nuclear Information System (INIS)

Park, J. W.; Hong, S. B.

2002-01-01

Scintillating optical fibers have several advantages over other conventional materials used for radiation detection. We have used glass and plastic scintillating fibers to detect gamma rays emitted from 60 Co and 137 Cs, and beta rays from 90 Sr. The sensors are constructed of single strand or multi-strand fibers of 1 mm diameter. The glass scintillating fiber used contains cerium-activated lithium-silicate as scintillating material and the plastic scintillating fiber used is Bicron model BCF-12. In this paper, we report the pulse-height spectra obtained by both sensor types, and analyze them in the aspect of their usability for radiation detectors. Our investigation suggests that the glass fiber can be used to develop gamma ray detectors which will function in high and low gamma ray flux environments. Use of the sensor for the beta ray detection was not satisfactory. The plastic fiber sensor did not work satisfactorily for the weak gamma sources, but did produce somewhat promising results. The scintillating plastic fiber offers some feasibility as beta ray sensor material

Simulated progress in double-beta decay

International Nuclear Information System (INIS)

Miley, H.S.; Arthur, R.J.; Avignone, F.T.

1993-09-01

A Monte Carlo code has been developed to accurately simulate double-beta decay measurements. Coincident gamma rays, beta spectra, and angular correlations have been added to adequately simulate a complete 100 Mo nuclear decay and provide corrections to experimentally determined detector efficiencies. This code has been used to strip certain low-background spectra obtained in the Homestake gold mine in Lead, SD, for the purpose of extremely sensitive materials assay for the construction of new, large, enriched germanium detectors. Assays as low as 9 μBq/g of 210 Pb in lead shielding were obtained

Towards a comprehensive X-ray approach for studying the photosynthetic manganese complex-XANES, K{alpha}/K{beta}/K{beta}-satellite emission lines, RIXS, and comparative computational approaches for selected model complexes

Energy Technology Data Exchange (ETDEWEB)

Zaharieva, I; Chernev, P; Risch, M; Gerencser, L; Haumann, M; Dau, H [Free University Berlin, FB Physik, Arnimallee 14, D-14195 Berlin (Germany); Berggren, G; Shevchenko, D; Anderlund, M [Dept. of Photochemistry and Molecular Science, Uppsala University, Box 523, S-751 20 Uppsala (Sweden); Weng, T C, E-mail: holger.dau@fu-berlin.d, E-mail: michael.haumann@fu-berlin.d [European Synchrotron Radiation Facility, BP 220, F-38043 Grenoble Cedex (France)

2009-11-15

Advanced X-ray spectroscopy experiments can contribute to elucidation of the mechanism of water oxidation in biological (tetra-manganese complex of Photosystem II) and artificial systems. Although the electronic structure of the catalytic metal site is of high interest, it is experimentally not easily accessible. Therefore, we and other researchers are working towards a comprehensive approach involving a combination of methods, namely (1) quantitative analysis of X-ray absorption near-edge structure (XANES) spectra collected at the K-edge and, in the long run, at the L-edge of manganese; (2) high-resolution X-ray emission spectroscopy (XES) of K{alpha} and K{beta} lines, (3) two-dimensional resonant inelastic X-ray scattering (RIXS) spectra. Collection of these spectroscopic data sets requires state-of-the-art synchrotron radiation facilities as well as experimental strategies to minimize the radiation-induced modifications of the samples. Data analysis requires the use and development of appropriate theoretical tools. Here, we present exemplary data collected for three multi-nuclear synthetic Mn complexes with the Mn ions in the oxidation states II, III, and IV, and for Mn{sup VII} of the permanganate ion. Emission spectra are calculated for the Mn{sup VII} ion using both multiple-scattering (MS) approach and time-dependent density functional theory (TDDFT).

X-ray investigations of sulfur-containing fungicides. II. Intramolecular forces governing the conformation of four novel alpha-phenylazo- and alpha-phenylhydrazono-beta-ketosulfones.

Science.gov (United States)

Wolf , W M

2001-02-01

The crystal and molecular structures of four novel beta-ketosulfones, phenyl benzoyl(phenylhydrazono)methyl sulfone (I), phenyl benzoyl(4-nitrophenylhydrazono)methyl sulfone (II), (benzoyl)(phenyl)(phenylazo)methyl phenyl sulfone (III) and (benzoyl)(phenyl)(3-chlorophenylazo)methyl 4-tolyl sulfone (IV), have been investigated using X-ray analysis and density functional theory supplemented by ab initio Hartree-Fock calculations. The conformations of (I) and (II) are stabilized by strong intramolecular resonance-assisted hydrogen bonds formed between the sulfonyl and the alpha-hydrazono moieties. The following increase of a positive charge on the S atoms is compensated via pi-conjugation and stereoelectronic back-donation from the nearby beta-carbonyl group. Compounds (III) and (IV) adopt a strongly distorted propeller shape with pivotal tetrahedral C1 atoms. Distortion mostly follows from the approximate coplanarity of the alpha-azophenyl and alpha-phenyl moieties opposite each other. The main stereoelectronic interactions involve the donation of electron density from the alpha-azo N2 towards the sulfonyl S and the beta-carbonyl C2 atoms.

A study on radiation safety measures for the use of high-energy beta-ray sources in medical fields

Energy Technology Data Exchange (ETDEWEB)

Park, Jae Woo; Yang, Jeong Seon; Kim, Hyeon Jo [Cheju National Univ., Cheju (Korea, Republic of)

2000-12-15

The scope of this study consists of : an investigation of the current application status of medical radioisotopes, Sr-90, Ho-166, Re-188, which emit beta-rays of energy greater than 1.5 Mev, analyses of the environments under which the above isotopes are used, estimation of personal radiation doses by using the MCNP-4C computer code for the situations in which high radiation doses might be probable, review of the USA's regulations related to safe use of the radioisotopes, investigation of past over-expose cases reported in the internet, analysis of the current domestic regulations, suggestion of safety measures necessary for the use of the radioisotopes.

Beta decay to the second 2+ excited state of 122Te

International Nuclear Information System (INIS)

Hayashi, Takeo; Yamada, Shigeru

1976-01-01

The first-forbidden beta transition in Sb-122 was studied by the angular correlation experiment and the beta-spectra. The special precautions were paid for counting the beta particles having energy lower than 750 keV in the beta-gamma angular correlation measurement. The sources of Sb-122 were obtained by irradiating enriched Sb-121 in the Kyoto University reactor. The reduced beta coefficient R(E) was obtained from the angular correlation function. The beta spectrum measurement was performed with a sector type double focusing beta-ray spectrometer. The R(E) values for the beta transitions were analyzed by using the simplex method as used by Manthuruthil and Poirier to compare the angular correlation data with the exact formula given by Morita and Morita. Sets of the nuclear matrix parameters thus obtained show that the condition for the cancellation effect is satisfied in the beta transition. (Kato, T.)

A 4{pi} Anticoincidence Arrangement for Measurements of Beta-Ray Emitting Isotopes; Montage a Anticoiencidence 4{pi} pour la Mesure des Radioisotopes Emetteurs Beta; 4{pi} sistema schetchikov antisovpadenij dlya izmerenij beta-izluchayushchikh izotopov; Aparato de Recuento 4{pi} en Anticoincidencia para Medir Emisores Beta

Energy Technology Data Exchange (ETDEWEB)

Srdoc, D. [Institute ' ' Ruder Boskovic' ' , Zagreb, Yugoslavia (Croatia)

1965-10-15

A 4{pi} anticoincidence, low-background counting system consisting of two specially designed parallel plate counters and a bridge anticoincidence circuit is described. Each counter is of a flat, mica window ''pancake'' type. The diameter of the counters is much larger than the gap between the plates. Good counting properties are obtained in spite of the unusual counter geometry, owing to the flexibility of the counter shape design when a neon-halogen mixture is used. The counters are so arranged that both windows face the sample, leaving a narrow slit for the sample holder. The sample is spread on a thin metalized plastic film. The pulses from both counters due to beta-particles coming from the sample are recorded, giving a 4{pi} counting geometry. The pulses due to cosmic particles triggering both counters simultaneously cancel out in a simple bridge anticoincidence arrangement, thus eliminating the need for an electronic circuit. Furthermore, the parallel plate counters used here for beta-particle counting possess a markedly reduced sensitivity to gamma-rays near the threshold voltage, resulting in a further lowering of the background. Sources of beta-particles of higher energies, as well as gamma-ray sources, can also be measured by the described system, because in the proposed geometry there is no possibility of triggering both counters simultaneously, as is the case with the conventional guard-counter arrangements. (author) [French] Le memoire decrit un ensemble de mesure a anticolhcidence 4{pi}, ayant un faible bruit de fond, compose de deux compteurs speciaux a plateaux paralleles relies par un pont d'anticofncidence. Ces deux compteurs sont de type circulaire plat a fenetre de mica. Le diametre du compteur est tres superieur a l'espace entre les plaques. Malgre sa geometrie inusitee, l'appareil a des proprietes de comptage satisfaisantes en raison de la souplesse que lui conferent ses caracteristiques lorsqu'on utilise un melange halogene-neon. Les

RBE [relative biological effectiveness] of tritium beta radiation to gamma radiation and x-rays analyzed by both molecular and genetic methods

International Nuclear Information System (INIS)

Lee, W.R.

1988-01-01

The relative biological effectiveness (RBE) of tritium beta radiation to 60 Co gamma radiation was determined using sex-linked recessive lethals (SLRL) induced in Drosophila melanogaster spermatozoa as the biological effect. The SLRL test, a measure of mutations induced in germ cells transmitted through successive generations, yields a linear dose-response curve in the range used in these experiments. From these ratios of the slopes of the 3 H beta and the 60 Co gamma radiation linear dose response curves, an RBE of 2.7 is observed. When sources of error are considered, this observation suggests that the tritium beta particle is 2.7 ± 0.3 times more effective per unit of energy absorbed in inducing gene mutations transmitted to successive generation than 60 Co gamma radiation. Ion tracks with a high density of ions (high LET) are more efficient than tracks with a low ion density (low LET) in inducing transmissible mutations, suggesting interaction among products of ionization. Molecular analysis of x-ray induced mutations shows that most mutations are deletions ranging from a few base pairs as determined from sequence data to multi locus deletions as determined from complementation tests and Southern blots. 14 refs., 1 fig

Beta-decay of {sup 103}In: evidence for the Gamow-Teller resonance near {sup 100}Sn

Energy Technology Data Exchange (ETDEWEB)

Karny, M. [Warsaw Univ. (Poland). Inst. of Experimental Physics; Batist, L.; Brown, B.A. [and others

1998-04-01

The {beta} decay of the neutron-deficient isotope {sup 103}In was investigated by using total absorption {gamma}-ray spectrometry on mass-separated sources. The measurement reveals a high-lying resonance of the {beta}-decay strength in striking disagreement with high-resolution {gamma}-ray data. The result is discussed in comparison with shell-model predictions. (orig.)

Structure of .beta.-galactosidase complexes

Czech Academy of Sciences Publication Activity Database

Dohnálek, Jan; Skálová, Tereza; Dušková, Jarmila; Petroková, Hana; Hašek, Jindřich; Lipovová, P.; Spiwok, V.; Strnad, Hynek; Králová, B.

2006-01-01

Roč. 13, č. 3 (2006), s. 137-138 ISSN 1211-5894. [Czech and Slovak Crystallographic Colloquium. 22.06.2006-24.06.2006, Grenoble] R&D Projects: GA AV ČR KJB500500512 Keywords : .beta.-galactosidase * X-ray diffraction * cold-active enzyme Subject RIV: EB - Genetics ; Molecular Biology http://www. xray .cz/ms/default.htm

Extração, estruturas e propriedades de alfa- e beta-quitina Extraction, structures and properties of alpha- AND beta-chitin

Directory of Open Access Journals (Sweden)

Sergio P. Campana-Filho

2007-06-01

Full Text Available The fact that alpha- and beta-chitin adopt different arrays in the solid state is explored to emphasize their different properties and distinct spectral characteristics and X ray diffraction patterns. The methods for their extraction from the biomass in view of the preservation of their native structures and aiming to fulfill the claims of purity and uniformity for potential applications are discussed. The different arrays adopted by alpha- and beta-chitin also result in distinct reactivities toward the deacetylation reaction. Thus, the deacetylation of beta-chitin is more efficient owing to the better accessibility to amide groups due to the lower crystallinity of this polymorph.

Measurement of gross beta radioactivity in high-level liquid waste

International Nuclear Information System (INIS)

Lu Feng; Lin Cansheng; Zhang Xianzi; Chen Guoan; Zhang Chonghai

1992-01-01

Using beta plastic scintillation counter of low level background, gross beta radioactivity of twelve samples for high-level liquid waste is determined directly. Beta efficiency curves of plastic scintillation counter for four mass thickness are calibrated in advance. Determining gross beta radioactivity, gross efficiency of the scintillation counter for various energy beta ray is calculated via weighted mean method with the ratio of radioactivity for each nuclide. The ratio of radioactivity for nuclides which have gamma disintegration is determined in terms of the radioactivity measured by gamma spectrometer. The ratio of the radioactivity for 90 Sr which has purity beta disintegration is calculated in terms of half life time approximation. The ratio of the radioactivity for 147 Pm which also has purity disintegration is calculated by means of apparent cooling-time approximation. The uncertainty of results for the present work is about +-15%

Weak interaction studies from nuclear beta decay

International Nuclear Information System (INIS)

Morita, M.

1981-01-01

The studies performed at the theoretical nuclear physics division of the Laboratory of Nuclear Studies, Osaka University, are reported. Electron spin density and internal conversion process, nuclear excitation by electron transition, beta decay, weak charged current, and beta-ray angular distributions in oriented nuclei have been studied. The relative intensity of internal conversion electrons for the case in which the radial wave functions of orbital electrons are different for electron spin up and down was calculated. The calculated value was in good agreement with the experimental one. The nuclear excitation following the transition of orbital electrons was studied. The calculated probability of the nuclear excitation of Os 189 was 1.4 x 10 - 7 in conformity with the experimental value 1.7 x 10 - 7 . The second class current and other problems on beta-decay have been extensively studied, and described elsewhere. Concerning weak charged current, the effects of all induced terms, the time component of main axial vector, all partial waves of leptons, Coulomb correction for the electrons in finite size nuclei, and radiative correction were studied. The beta-ray angular distribution for the 1 + -- 0 + transition in oriented B 12 and N 12 was investigated. In this connection, investigation on the weak magnetism to include all higher order corrections for the evaluation of the spectral shape factors was performed. Other works carried out by the author and his collaborators are also explained. (Kato, T.)

Proton microprobe analysis of pancreatic. beta. cells

Energy Technology Data Exchange (ETDEWEB)

Lindh, U [Uppsala Univ. (Sweden). Gustaf Werner Inst.; Juntti-Berggren, L; Berggren, P O; Hellman, B [Uppsala Univ. (Sweden)

1985-01-01

Freeze-dried pancreas sections from obese hyperglycemic mice were subjected to proton bombardment and the elemental contents in the ..beta.. cells and the exocrine part were obtained from the characteristic X-rays emitted. Quantitative data were provided for 18 different elements. The mole ratio between K and Na exceeded 10, implying that neither the sample preparation nor the irradiation had induced significant diffuse changes. With the demonstration of this high K/Na ratio it seems likely that also the ..beta.. cells are equipped with an efficient Na/sup +//K/sup +/ pump. The ..beta.. cells contained about 70 mmoles Cl per litre cell water. Observed amounts of Ca and Mg were equivalent to those previously recorded by electrothermal atomic absorption spectroscopy. The significant role of Zn for the storage of insulin was emphasized by the demonstration of 3 times as much of this element in the ..beta.. cells as compared with the exocrine pancreas. In addition, the sensitivity of the proton microprobe enabled measurements of various trace elements such as Rb, Cr, Cu, Al and Pb not previously demonstrated in the pancreatic ..beta.. cells.

Beta-Excited Sources of Electromagnetic Radiation; Sources de rayonnements electromagnetiques excites par des particules beta; Vozbuzhdennye beta-chastitsami istochniki ehlektromagnitnogo izlucheniya; Fuentes de radiacion electromagnetica excitadas por particulas beta

Energy Technology Data Exchange (ETDEWEB)

Cameron, J F; Rhodes, J R [Physics Group, Isotope Research Division, (AERE), Wantage Research Laboratory, Wantage, Berks (United Kingdom)

1962-01-15

Beta-excited sources of electromagnetic radiation covering the energy region 1-200 keV and suitable for industrial use are described. H{sup 3}, Pm{sup 147}, Kr{sup 85}, Tl{sup 204} and (Sr+Y){sup 90} were chosen as sources of beta particles by the criteria of long half-life, low price, ready availability and high specific activity. The {beta}-excited sources have been designed on the basis of a compromise between practical source construction and the best theoretical efficiency in a given energy region. In their paper, the authors calculate the number of photons produced per beta particle and consider how the results must be corrected for self-absorption of the X-rays. In the calculations account is taken of both bremsstrahlung and characteristic {alpha}-radiation; optimum characteristic X-ray yield is achieved for targets with an atomic number between 40 and 60. ''Sandwich'' targets of 1-2 beta half-value thicknesses are found to give maximum photon-yields in the desired energy region. Al, Ag and Au are suitable from the manufacturing point of view as source coverings. They were also found to give satisfactory bremsstrahlung and X-ray yields and distribution for various energy regions in the range 1-200 keV when correctly combined with the above-mentioned D-emitters. Some energy spectra are given and absorption curves in Al and Fe are shown for the best source-target combinations. The difference between sources constructed of {beta}-emitters sandwiched between target foils and intimate source-target mixtures was found to be small. Tables are given as a guide to the best source to be used for a particular absorber thickness range. (author) [French] Les auteurs decrivent des sources de rayonnements electromagnetiques excites par des particules beta, couvrant une gamme d'energies allant de 1 a 200 keV et convenant aux usages industriels. Comme sources de particules beta on a choisi le tritium, le {sup 147}Pm, le {sup 85}Kr, le {sup 204}Tl et le {sup 90}(Sr+Y), en

Beta-glucan ameliorates gamma-rays induced oxidative injury in male Swiss albino rats

International Nuclear Information System (INIS)

Salama, S.F.

2011-01-01

1,3-beta-D-Glucan is a natural polysaccharide derived from the cell walls of bakers yeast Saccharomyces cerevsiae with immunoenhancing and potent antioxidant effects. This study investigated the pathways through which beta-glucan gavage treatment (50mg/kg) exerts its effect on radiation-induced oxidative damage in male rats. Beta-glucan was given orally to male rats; 3 hours post gamma-irradiation at dose 5Gy, for 10 and 20 days post-irradiation level were assayed, being remarkable indicators in cell oxidative stress. Results pointed out that irradiation at 5Gy significantly depressed all blood parameters, such as erythrocytes count (RBCs), hemoglobin content (Hb), hematocrit value (Hct), total leucocytes count and absolute lymphocytes and neutrophils counts, blood glutathione (GSH) level and conversely elevated level of serum ascorbyl radical (AsR), product of lipid peroxidation (MDA melanodialdehyde), triglycerides and cholesterol. Total leucocytes count and absolute lymphocytes and neutrophils counts, RBCs, Hb, Hct, blood GSH and serum MDA of irradiated animals receiving beta-glucan administration were exhibited significant differences compared to the irradiated group. Marrow count and the percentage of viability and spleenocytes viability were also significantly decreased. Beta-glucan treatment accelerates recovery of cell damage induced by ionizing irradiation through its potential immune-enhancing activity and free radical scavenging ability that is partially mediated through stimulation of immunohaematological system thus could play a role in regulating irradiation complications

Study of $\\beta$-delayed neutron decay of $^{8}$He

CERN Multimedia

The goal of the present proposal is to study $\\beta$-delayed neutron decay branch of $^{8}$He. The energy spectra of the emitted neutrons will be measured in the energy range of 0.1 – 6 MeV using the VANDLE spectrometer. Using coincident $\\gamma$-ray measurement, components of the spectrum corresponding to transitions to the ground- and first- excited states of $^{7}$Li will be disentangled. The new data will allow us to get a more complete picture of the $\\beta$-decay of $^{8}$He and to clarify the discrepancy between the B(GT) distributions derived from the $\\beta$-decay and $^{8}$He(p, n)$^{8}$Li reaction studies.

Signal and background studies for the search of neutrinoless double beta decay in GERDA

Energy Technology Data Exchange (ETDEWEB)

Agostini, Matteo

2013-04-24

The GERDA experiment searches for the neutrinoless double beta decay in Ge-76, by operating bare HPGe detectors in ultra-pure liquid Ar. This dissertation presents a first decomposition of the background measured in the current data-taking phase. The background at the energy of interest was found to be dominated by {sup 214}Bi, {sup 208}Tl and {sup 42}K gamma-rays, with secondary contributions from {sup 42}K and {sup 214}Bi beta-rays, and {sup 210}Po alpha-rays. For the forthcoming upgrade of the apparatus, a new HPGe detector design (BEGe) has been studied, with focus on its capability of suppressing the identified backgrounds through pulse shape analysis. This included the development of a comprehensive modeling of the detectors and the experimental characterization of their response to surface interactions. The achieved results show that GERDA can improve the present limit on the neutrinoless double beta decay half-life by an order of magnitude.

Signal and background studies for the search of neutrinoless double beta decay in GERDA

International Nuclear Information System (INIS)

Agostini, Matteo

2013-01-01

The GERDA experiment searches for the neutrinoless double beta decay in Ge-76, by operating bare HPGe detectors in ultra-pure liquid Ar. This dissertation presents a first decomposition of the background measured in the current data-taking phase. The background at the energy of interest was found to be dominated by 214 Bi, 208 Tl and 42 K gamma-rays, with secondary contributions from 42 K and 214 Bi beta-rays, and 210 Po alpha-rays. For the forthcoming upgrade of the apparatus, a new HPGe detector design (BEGe) has been studied, with focus on its capability of suppressing the identified backgrounds through pulse shape analysis. This included the development of a comprehensive modeling of the detectors and the experimental characterization of their response to surface interactions. The achieved results show that GERDA can improve the present limit on the neutrinoless double beta decay half-life by an order of magnitude.

Relation between the 2{nu}{beta}{beta} and 0{nu}{beta}{beta} nuclear matrix elements

Energy Technology Data Exchange (ETDEWEB)

Vogel, Petr [Kellogg Radiation Laboratory, Caltech, Pasadena, CA 91125 (United States); Simkovic, Fedor [Department of Nuclear Physics and Biophysics, Comenius University, Mlynska dolina F1, SK-84248 Bratislava (Slovakia)

2011-12-16

A formal relation between the GT part of the nuclear matrix elements M{sub GT}{sup 0{nu}} of 0{nu}{beta}{beta} decay and the closure matrix elements M{sub cl}{sup 2{nu}} of 2{nu}{beta}{beta} decay is established. This relation is based on the integral representation of these quantities in terms of their dependence on the distance r between the two nucleons undergoing transformation. We also discuss the difficulties in determining the correct values of the closure 2{nu}{beta}{beta} decay matrix elements.

Annihilation gamma ray background characterization and rejection for a positron camera

International Nuclear Information System (INIS)

Levin, C.S.; Tornai, M.P.; MacDonald, L.R.

1996-01-01

We have developed a miniature (1.2 cm 2 ) beta-ray camera prototype to assist a surgeon in locating and removing the margins of a resected tumor. When imaging positron emitting radiopharmaceuticals, annihilation gamma ray interactions in the detector can mimic those of the betas. The extent of the background contamination depends on the detector, geometry and tumor specificity of the radiopharmaceutical. We have characterized the effects that annihilation gamma rays have on positron imaging with the camera. We studied beta and gamma ray detection rates and imaging using small positron or electron sources directly exposed to the detector to simulate hot tumor remnants and a cylinder filled with 18 F to simulate annihilation background from the brain. For various ratios of phantom brain/tumor activity, a annihilation gamma rate of 1.8 cts/sec/gCi was measured in the CaF 2 (Eu) detector. We present two gamma-ray background rejection schemes that use a β-γ coincidence. Results show that the coincidence methods works with ∼99% gamma ray rejection efficiency

Detection of Beta-rays by using Plastic Scintillating Fibers

International Nuclear Information System (INIS)

Park, Chan Hee

2005-02-01

Optical fibers have been used as sensing materials in various nuclear applications. Optical fiber sensors have proven to present several advantages as compared with other conventional sensors. They can be prepared in very small sizes and they are light enough to be easily put into very narrow channels such as between nuclear to be easily put into very narrow channels such as between nuclear fuel rods. No electrical power is needed to the sensor part so they are less susceptible to troubles in harsh environments such as underground and underwater. Optical fiber sensors cost relatively cheap to make, so that they are more suitable for multi-point radiation monitoring such as in nuclear power plants, accelerators, fusion study facilities. If one develops radiation sensors using scintillating optical fibers, that can directly measure the concentration of 3 H or 14 C in radioactive liquid, they can be useful tools to substitute the current liquid scintillation counters. They can be also used to measure the radioactivity of liquid radioactive wastes by dipping into the liquid wastes. Recently, several new scintillating materials of high density and low hygroscopicity have been found, and they can be transformed into good radiation-detection tools when they are combined with optical fibers. In this study, we have used commercially available plastic scintillating fibers of Bicron model BCF-12 (0.5mm, 1mm in diameter) to detect beta rays emitted from 3 H, 14 C. Several types of radiation sensors were constructed : each was constructed with thirty strands of the fibers being packed an aluminum tube. The optical signals generated inside the fiber bundle were converted into electrical pluses by a photomultiplier tube(PMT). The pulses were counted either through a non-coincidence circuit or a coincidence circuit. Two types of sensors were constructed for the non-coincidence counting. The open type (sensor A) is a sensor for which one end of the fibers is open and the other end

The use of cosmic-ray muons in the energy calibration of the Beta-decay Paul Trap silicon-detector array

Energy Technology Data Exchange (ETDEWEB)

Hirsh, T. Y.; Perez Galvan, A.; Burkey, M.; Aprahamian, A.; Buchinger, F.; Caldwell, S.; Clark, J. A.; Gallant, A.; Heckmaier, E.; Levand, A. F.; Savard, G.

2018-04-01

This article presents an approach to calibrate the energy response of double-sided silicon strip detectors (DSSDs) for low-energy nuclear-science experiments by utilizing cosmic-ray muons. For the 1-mm-thick detectors used with the Beta-decay Paul Trap, the minimum-ionizing peak from these muons provides a stable and time-independent in situ calibration point at around 300 keV, which supplements the calibration data obtained above 3 MeV from sources. The muon-data calibration is achieved by comparing experimental spectra with detailed Monte Carlo simulations performed using GEANT4 and CRY codes. This additional information constrains the calibration at lower energies, resulting in improvements in quality and accuracy.

Graphite mixed magnesium borate TL dosemeters for beta ray dosimetry

DEFF Research Database (Denmark)

Prokic, M; Christensen, Poul

1984-01-01

Sintered MgB4O7:Dy dosemeters with graphite contents from 1 to 10% were investigated for application for personnel dosimetry. Data are given on dose response, dose threshold, reproducibility, beta energy response and fading. Furthermore, results from practical field experiments are presented...

Beta-spectrometer with Si-detectors for the study of 144Ce-144Pr decays

Science.gov (United States)

Alexeev, I. E.; Bakhlanov, S. V.; Bazlov, N. V.; Chmel, E. A.; Derbin, A. V.; Drachnev, I. S.; Kotina, I. M.; Muratova, V. N.; Pilipenko, N. V.; Semyonov, D. A.; Unzhakov, E. V.; Yeremin, V. K.

2018-05-01

Here we present the specifications of a newly developed beta-spectrometer, based on full absorption Si(Li) detector and thin transmission detector, allowing one to perform efficient separation beta-radiation and accompanying X-rays and gamma radiation. Our method is based on registration of coincident events from both detectors. The spectrometer can be used for precision measurements of various beta-spectra, namely for the beta-spectrum shape study of 144Pr, which is considered to be an advantageous anti-neutrino source for sterile neutrino searches.

Beta-delayed proton emission from {sup 20}Mg

Energy Technology Data Exchange (ETDEWEB)

Lund, M.V.; Fynbo, H.O.U.; Howard, A.M.; Kirsebom, O.S.; Munch, M.; Riisager, K. [Aarhus University, Department of Physics and Astronomy, Aarhus C (Denmark); Andreyev, A.; Wadsworth, R. [University of York, Department of Physics, York (United Kingdom); Borge, M.J.G. [CSIC, Instituto de Estructura de la Materia, Madrid (Spain); CERN, ISOLDE, PH Department, Geneva 23 (Switzerland); Cederkaell, J. [Lund University, Department of Nuclear Physics, Lund (Sweden); Witte, H. de; Huyse, M.; Duppen, P. van [Instituut voor Kern- en Stralingsfysica, KU-Leuven, Leuven (Belgium); Fraile, L.M.; Vedia, V. [Universidad Complutense de Madrid, CEI Moncloa, Facultad de Ciencias Fisicas, Madrid (Spain); Greenlees, P.T.; Konki, J.; Rahkila, P. [University of Helsinki, Helsinki Institute of Physics, Helsinki (Finland); University of Jyvaeskylae, Department of Physics, Jyvaeskylae (Finland); Harkness-Brennan, L.J.; Judson, D.S.; Page, R.D. [University of Liverpool, Department of Physics, Oliver Lodge Laboratory, Liverpool (United Kingdom); Jonson, B.; Lindberg, S.; Nilsson, T. [Chalmers University of Technology, Department of Physics, Goeteborg (Sweden); Kurcewicz, J.; Madurga, M.; Rapisarda, E. [CERN, ISOLDE, PH Department, Geneva (Switzerland); Lazarus, I.; Pucknell, V. [STFC Daresbury, Daresbury, Warrington (United Kingdom); Lica, R. [CERN, ISOLDE, PH Department, Geneva (Switzerland); ' ' Horia Hulubei' ' National Institute of Physics and Nuclear Engineering, Magurele (Romania); Marginean, N.; Marginean, R.; Mihai, C.; Negret, A.; Pascu, S.; Rotaru, F.; Stanoiu, M.; Turturica, A. [' ' Horia Hulubei' ' National Institute of Physics and Nuclear Engineering, Magurele (Romania); Marroquin, I.; Nacher, E.; Perea, A.; Tengblad, O. [CSIC, Instituto de Estructura de la Materia, Madrid (Spain); Sotty, C. [Instituut voor Kern- en Stralingsfysica, KU-Leuven, Leuven (Belgium); ' ' Horia Hulubei' ' National Institute of Physics and Nuclear Engineering, Magurele (Romania); Warr, N. [Universitaet Koeln, Institut fuer Kernphysik, Koeln (Germany); Collaboration: IDS Collaboration

2016-10-15

Beta-delayed proton emission from {sup 20} Mg has been measured at ISOLDE, CERN, with the ISOLDE Decay Station (IDS) setup including both charged-particle and gamma-ray detection capabilities. A total of 27 delayed proton branches were measured including seven so far unobserved. An updated decay scheme, including three new resonances above the proton separation energy in {sup 20}Na and more precise resonance energies, is presented. Beta-decay feeding to two resonances above the Isobaric Analogue State (IAS) in {sup 20}Na is observed. This may allow studies of the 4032.9(2.4) keV resonance in {sup 19}Ne through the beta decay of {sup 20}Mg, which is important for the astrophysically relevant reaction {sup 15}O(α, γ){sup 19}Ne. Beta-delayed protons were used to obtain a more precise value for the half-life of {sup 20}Mg, 91.4(1.0) ms. (orig.)

A mini X-ray generator as an alternative to a ⁹⁰Sr/⁹⁰Y beta source in luminescence dating

DEFF Research Database (Denmark)

Andersen, C.E.; Bøtter-Jensen, L.; Murray, A.S.

2003-01-01

We have carried out an investigation to test whether mini X-ray generators are a suitable alternative to radioactive sources in luminescence dating. The study has mainly been motivated by the need for high dose rates (similar to 1 Gy/s) to make dating of older samples using regeneration protocols...... with a sample of thermally sensitized sedimentary quartz suggest that we can use beta and X-ray irradiation interchangeably from the point of view of construction of growth curves by the single-aliquot regenerative-dose protocol. (C) 2003 Elsevier Science Ltd. All rights reserved....

$\\beta$-decay studies using total-absorption spectroscopy

CERN Document Server

Algora, A; García-Borge, M J; Cano-Ott, D; Collatz, R; Courtin, S; Dessagne, P; Fraile-Prieto, L M; Gadea, A; Gelletly, W; Hellström, M; Janas, Z; Jungclaus, A; Kirchner, R; Karny, M; Le Scornet, G; Miehé, C; Maréchal, F; Moroz, F; Nacher, E; Poirier, E; Roeckl, E; Rubio, B; Rykaczewski, K; Taín, J L; Tengblad, O; Wittmann, V

2004-01-01

$\\beta$-decay experiments are a primary source of information for nuclear-structure studies and at the same time complementary to in- beam investigations of nuclei far from stability. Although both types of experiment are mainly based on $\\gamma$-ray spectroscopy, they face different experimental problems. The so-called " Pandemonium effect " is a critical problem in $\\beta$-decay if we are to test theoretically calculated transition probabilities. In this contribution we will present a solution to this problem using total absorption spectroscopy methods. We will also present some examples of experiments carried out with the Total Absorption Spectrometer (TAS) at GSI and describe a new device LUCRECIA recently installed at CERN.

A beta ray spectrometer based on a two-, or three-element silicon detector coincidence telescope

International Nuclear Information System (INIS)

Horowitz, Y.S.; Weizman, Y.; Hirning, C.R.

1995-01-01

The operation of a beta ray energy spectrometer based on a two-or three-element silicon detector telescope is described. The front detector (A) is a thin, totally depleted, silicon surface barrier detector either 40 μm, 72 μm or 98 μm thick. The back detector (C) is a Li compensated silicon detector, 5000 μm thick. An additional thin detector can be inserted between these two detectors when additional photon rejection capability is required in intense photon fields. The capability of the spectrometer to reject photons is based on the fact that incident photons will have a small probability of simultaneously losing detectable energy in two detectors and an even smaller probability of losing detectable energy in all three detectors. Electrons, however, above a low energy threshold, will always record simultaneous, events in all three detectors. The spectrometer is capable of measuring electron energies from a lower energy coincidence threshold of 70 keV with 60% efficiency increasing to 100% efficiency in the energy region between 150 keV and 2.5 MeV. (Author)

Hanford beta-gamma personnel dosimeter prototypes and evaluation

International Nuclear Information System (INIS)

Fix, J.J.; Holbrook, K.L.; Soldat, K.L.

1983-04-01

Upgraded and modified Hanford dosimeter prototypes were evaluated for possible use at Hanford as a primary beta-gamma dosimeter. All prototypes were compatible with the current dosimeter card and holder design, as well as processing with the automated Hanford readers. Shallow- and deep-dose response was determined for selected prototypes using several beta sources, K-fluorescent x rays and filtered x-ray techniques. All prototypes included a neutron sensitive chip. A progressive evaluation of the performance of each of the upgrades to the current dosimeter is described. In general, the performance of the current dosimeter can be upgraded using individual chip sensitivity factors to improve precision and an improved algorithm to minimize bias. The performance of this dosimeter would be adequate to pass all categories of the ANSI N13.11 performance criteria for dosimeter procesors, provided calibration techniques compatible with irradiations adopted in the standard were conducted. The existing neutron capability of the dosimeter could be retained. Better dosimeter performance to beta-gamma radiation can be achieved by modifying the Hanford dosimeter so that four of the five chip positions are devoted to calculating these doses instead of the currently used two chip positions. A neutron sensitive chip was used in the 5th chip position, but all modified dosimeter prototypes would be incapable of discriminating between thermal and epithermal neutrons. An improved low energy beta response can be achieved for the current dosimeter and all prototypes considered by eliminating the security credential. Further improvement can be obtained by incorporating the 15-mil thick TLD-700 chips

Transforming growth factor beta 1 expression and inflammatory cells in tooth extraction socket after X-ray irradiation

Directory of Open Access Journals (Sweden)

Ramadhan Hardani Putra

2016-06-01

Full Text Available Background: Radiographic examination is often used in dentistry to evaluate tooth extraction complications. X-ray used in radiographic examination, however, has negative effects, including damage to DNA and inflammatory response during wound healing process. Purpose: This study aimed to analyze the effects of X-ray irradiation on transforming growth factor beta 1 (TGF-ß1 expression and number of inflammatory cells in tooth extraction sockets. Method: Thirty rats were divided into three groups, which consist of control group (with a radiation of 0 mSv, treatment group 1 (with a radiation of 0.08 mSv, and treatment group 2 (with a radiation of 0.16 mSv. These rats in each group were sacrificed on days 3 and 5 after treatment. Inflammatory cells which were observed in this research were PMN, macrophages, and lymphocytes. Histopathological and immunohistochemical examinations were used to calculate the number of inflammatory cells and TGF-ß1 expression. Obtained data were analyzed using SPSS 16.0 software with one way ANOVA and Tukey’s HSD tests. Result: There was no significant decrease in the number of PMN. On the other hand, there were significant decreases in the number of macrophages and lymphocytes in the sacrificed group on day-5 with the radiation of 0.16 mSv. Similarly, the most significant decreased expression of TGF-ß1 was found in the group sacrificed on day 5 with the radiation of 0.16 mSv. Conclusion: X-ray irradiation with 0.08 mSv and 0.16 mSv doses can decrease TGF-ß1 expression and number of inflammatory cells in tooth extraction sockets on day 3 and 5 post extraction.

Natural triple beta-stranded fibrous folds.

Science.gov (United States)

Mitraki, Anna; Papanikolopoulou, Katerina; Van Raaij, Mark J

2006-01-01

A distinctive family of beta-structured folds has recently been described for fibrous proteins from viruses. Virus fibers are usually involved in specific host-cell recognition. They are asymmetric homotrimeric proteins consisting of an N-terminal virus-binding tail, a central shaft or stalk domain, and a C-terminal globular receptor-binding domain. Often they are entirely or nearly entirely composed of beta-structure. Apart from their biological relevance and possible gene therapy applications, their shape, stability, and rigidity suggest they may be useful as blueprints for biomechanical design. Folding and unfolding studies suggest their globular C-terminal domain may fold first, followed by a "zipping-up" of the shaft domains. The C-terminal domains appear to be important for registration because peptides corresponding to shaft domains alone aggregate into nonnative fibers and/or amyloid structures. C-terminal domains can be exchanged between different fibers and the resulting chimeric proteins are useful as a way to solve structures of unknown parts of the shaft domains. The following natural triple beta-stranded fibrous folds have been discovered by X-ray crystallography: the triple beta-spiral, triple beta-helix, and T4 short tail fiber fold. All have a central longitudinal hydrophobic core and extensive intermonomer polar and nonpolar interactions. Now that a reasonable body of structural and folding knowledge has been assembled about these fibrous proteins, the next challenge and opportunity is to start using this information in medical and industrial applications such as gene therapy and nanotechnology.

{beta}-Delayed proton-decay study of {sup 20}Mg and its implications for the {sup 19}Ne(p,{gamma}){sup 20}Na breakout reaction in X-ray bursts

Energy Technology Data Exchange (ETDEWEB)

Wallace, J.P., E-mail: J.P.Wallace@sms.ed.ac.uk [University of Edinburgh, Edinburgh, EH9 3JZ (United Kingdom); Woods, P.J.; Lotay, G. [University of Edinburgh, Edinburgh, EH9 3JZ (United Kingdom); Alharbi, A.; Banu, A. [Cyclotron Institute, Texas A and M University, College Station, TX (United States); David, H.M.; Davinson, T. [University of Edinburgh, Edinburgh, EH9 3JZ (United Kingdom); McCleskey, M.; Roeder, B.T.; Simmons, E.; Spiridon, A.; Trache, L.; Tribble, R.E. [Cyclotron Institute, Texas A and M University, College Station, TX (United States)

2012-05-30

Under astrophysical conditions of high temperature and density, such as for example found in X-ray bursts, breakout can occur from the hot CNO cycles into the rapid proton capture process. A key breakout route is via the sequence {sup 15}O({alpha},{gamma}){sup 19}Ne(p,{gamma}){sup 20}Na. The {sup 19}Ne(p,{gamma}){sup 20}Na reaction rate is expected to be dominated by a single resonance at 457(3) keV. The identity of the resonance has been under discussion for a long time, with J{sup {pi}}=1{sup +} and 3{sup +} assignments suggested. In this study of the {beta}-delayed proton decay of {sup 20}Mg we report a new, significantly more stringent, upper limit on the {beta}-decay branch to this state of 0.02% with a confidence level of 90%. This makes a 1{sup +} assignment highly unlikely and favours a 3{sup +} assignment for which no branch is expected to be observed. The 3{sup +} state is predicted to have a significantly higher resonance strength, and to produce a proportionately higher {sup 19}Ne(p,{gamma}){sup 20}Na reaction rate in X-ray burst conditions.

Physical changes of beta-sitosterol crystals in oily suspensions during heating

DEFF Research Database (Denmark)

von Bonsdorff-Nikander, Anna; Lievonen, Satu; Christiansen, Leena

2005-01-01

with the mechanical properties of the suspensions during heating were studied by using variable temperature X-ray powder diffractometry (VT-XRPD), differential scanning calorimetry (DSC), and dynamic mechanical analysis (DMA). Hydrated beta-sitosterol crystals in an oil-suspension dehydrated, despite the composition...... of the suspensions, at low temperatures. At high beta-sitosterol concentration, the monohydrate crystal form changed partially to a hemihydrated form, and when only a small amount of water was initially incorporated, the hemihydrate crystal form dehydrated to a mostly anhydrate crystal form. The released water......, which was immiscible in the surrounding oil, caused the recrystallization of hydrated beta-sitosterol during cooling. This procedure indicated a reversible dehydration process. Structural and thermal analysis of beta-sitosterol crystals in suspensions, together with mechanical analysis made it possible...

X-ray Diffraction Study of Arsenopyrite at High Pressure

Energy Technology Data Exchange (ETDEWEB)

D Fan; M Ma; W Zhou; S Wei; Z Chen; H Xie

2011-12-31

The high-pressure X-ray diffraction study of a natural arsenopyrite was investigated up to 28.2 GPa using in situ angle-dispersive X-ray diffraction and a diamond anvil cell at National Synchrotron Light Source, Brookhaven National Laboratory. The 16:3:1 methanol-ethanol-water mixture was used as a pressure-transmitting medium. Pressures were measured using the ruby-fluorescence method. No phase change has been observed up to 28.2 GPa. The isothermal equation of state (EOS) was determined. The values of K{sub 0}, and K'{sub 0} refined with a third-order Birch-Murnaghan EOS are K{sub 0} = 123(9) GPa, and K'{sub 0} = 5.2(8). Furthermore, we confirm that the linear compressibilities ({beta}) along a, b and c directions of arsenopyrite is elastically isotropic ({beta}{sub a} = 6.82 x 10{sup -4}, {beta}{sub b} = 6.17 x 10{sup -4} and {beta}{sub c} = 6.57 x 10{sup -4} GPa{sup -1}).

BETA digital beta radiometer

International Nuclear Information System (INIS)

Borovikov, N.V.; Kosinov, G.A.; Fedorov, Yu.N.

1989-01-01

Portable transportable digital beta radiometer providing for measuring beta-decay radionuclide specific activity in the range from 5x10 -9 up to 10 -6 Cu/kg (Cu/l) with error of ±25% is designed and introduced into commercial production for determination of volume and specific water and food radioactivity. The device specifications are given. Experience in the BETA radiometer application under conditions of the Chernobyl' NPP 30-km zone has shown that it is convenient for measuring specific activity of the order of 10 -8 Cu/kg, and application of a set of different beta detectors gives an opportunity to use it for surface contamination measurement in wide range of the measured value

Investigation of beta ray attenuation in CaSO4:Dy(Tm)-teflon rods

International Nuclear Information System (INIS)

Szabo, P.P.

1990-12-01

Ultrathin discs were prepared from CaSO 4 :Dy(Tm)-teflon rods by cutting them with a microtom. The effect of cutting was studied experimentally. It was found that the cutting does not affect the TL signal of the discs, so one will be able to irradiate the rod and cut it afterwards which means that this method can be applied in the dosimetry of boundaries or to establish the energy of beta radiation. Depth dose distribution measurements were carried out by irradiating the rods with beta sources. (K.A.) 5 refs.; 6 figs

LHCb: $2\\beta_s$ measurement at LHCb

CERN Multimedia

Conti, G

2009-01-01

A measurement of $2\\beta_s$, the phase of the $B_s-\\bar{B_s}$ oscillation amplitude with respect to that of the ${\\rm b} \\rightarrow {\\rm c^{+}}{\\rm W^{-}}$ tree decay amplitude, is one of the key goals of the LHCb experiment with first data. In the Standard Model (SM), $2\\beta_s$ is predicted to be $0.0360^{+0.0020}_{-0.0016} \\rm rad$. The current constraints from the Tevatron are: $2\\beta_{s}\\in[0.32 ; 2.82]$ at 68$\\%$CL from the CDF experiment and $2\\beta_{s}=0.57^{+0.24}_{-0.30}$ from the D$\\oslash$ experiment. Although the statistical uncertainties are large, these results hint at the possible contribution of New Physics in the $B_s-\\bar{B_s}$ box diagram. After one year of data taking at LHCb at an average luminosity of $\\mathcal{L}\\sim2\\cdot10^{32}\\rm cm^{-2} \\rm s^{-1}$ (integrated luminosity $\\mathcal{L}_{\\rm int}\\sim 2 \\rm fb^{-1}$), the expected statistical uncertainty on the measurement is $\\sigma(2\\beta_s)\\simeq 0.03$. This uncertainty is similar to the $2\\beta_s$ value predicted by the SM.

Optimization of plastic scintillator thicknesses for online beta/gamma detection

Directory of Open Access Journals (Sweden)

Pourtangestani K.

2012-04-01

Full Text Available For efficient beta detection in a mixed beta gamma field, Monte Carlo simulation models have been built to optimize the thickness of a plastic scintillator, used in a whole body monitor. The simulation has been performed using the MCNP/X code for different thicknesses of plastic scintillator from 150 μm to 600 μm. The relationship between the thickness of the scintillator and the efficiency of the detector has been analyzed. For 150 μm thickness, an experimental investigation has been conducted with different beta sources at different positions on the scintillator and the counting efficiency of the unit has been measured. Evaluated data along with experimental ones have been discussed. A thickness of 300 μm to 500 μm has been found to be the optimum thickness for high efficiency beta detection in the presence of low energy gamma-rays.

Development of a new family of conformationally restricted peptides as potent nucleators of beta-turns. Design, synthesis, structure, and biological evaluation of a beta-lactam peptide analogue of melanostatin.

Science.gov (United States)

Palomo, Claudio; Aizpurua, Jesus M; Benito, Ana; Miranda, José Ignacio; Fratila, Raluca M; Matute, Carlos; Domercq, Maria; Gago, Federico; Martin-Santamaria, Sonsoles; Linden, Anthony

2003-12-31

Novel enantiopure (i)-(beta-lactam)-(Gly)-(i+3) peptide models, defined by the presence of a central alpha-alkyl-alpha-amino-beta-lactam ring placed as the (i+1) residue, have been synthesized in a totally stereocontrolled way by alpha-alkylation of suitable N-[bis(trimethylsilyl)methyl]-beta-lactams. The structural properties of these beta-lactam pseudopeptides have been studied by X-ray crystallography, Molecular Dynamics simulation, and NOESY-restrained NMR simulated annealing techniques, showing a strong tendency to form stable type II or type II' beta-turns either in the solid state or in highly coordinating DMSO solutions. Tetrapeptide models containing syn- or anti-alpha,beta-dialkyl-alpha-amino-beta-lactam rings have also been synthesized and their conformations analyzed, revealing that alpha-alkyl substitution is essential for beta-turn stabilization. A beta-lactam analogue of melanostatin (PLG amide) has also been prepared, characterized as a type-II beta-turn in DMSO-d6 solution, and tested by competitive binding assay as a dopaminergic D2 modulator in rat neuron cultured cells, displaying moderate agonist activity in the micromolar concentration range. On the basis of these results, a novel peptidomimetic design concept, based on the separation of constraint and recognition elements, is proposed.

Investigation of High Temperature Ductility Losses in Alpha-Beta Titanium Alloys

Science.gov (United States)

1988-04-01

Strain Rate . ...... 89 4.1.3 Results of Initial Tests .9.... 94 4.2 CCT Diagram Development .. ......... .. 94 4.3 Lattice Incompatibility Measurements...123 5.1 Phase Stability and Transformations . . . 124 5.1.1 CCT Diagrams ........... 126 Aluminum Additions. ........ .147 Beta... CCT ) Diagram of Ti-6211..............101 1 4.6 High-Temperature X-Ray Diffraction Specimen Configurations..............106 4.7 High-Temperature X-Ray

Sealed drift tube cosmic ray veto counters

International Nuclear Information System (INIS)

Rios, R.; Tatar, E.; Bacon, J.D.; Bowles, T.J.; Hill, R.; Green, J.A.; Hogan, G.E.; Ito, T.M.; Makela, M.; Morris, C.L.; Mortenson, R.; Pasukanics, F.E.; Ramsey, J.; Saunders, A.; Seestrom, S.J.; Sondheim, W.E.; Teasdale, W.; Saltus, M.; Back, H.O.; Cottrell, C.R.

2011-01-01

We describe a simple drift tube counter that has been used as a cosmic ray veto for the UCNA experiment, a first-ever measurement of the neutron beta-asymmetry using ultra-cold neutrons. These detectors provide an inexpensive alternative to more conventional scintillation detectors for large area cosmic ray anticoincidence detectors.

Anodic Aluminum Oxide Membrane-Assisted Fabrication of beta-In(2)S(3) Nanowires.

Science.gov (United States)

Shi, Jen-Bin; Chen, Chih-Jung; Lin, Ya-Ting; Hsu, Wen-Chia; Chen, Yu-Cheng; Wu, Po-Feng

2009-06-06

In this study, beta-In(2)S(3) nanowires were first synthesized by sulfurizing the pure Indium (In) nanowires in an AAO membrane. As FE-SEM results, beta-In(2)S(3) nanowires are highly ordered, arranged tightly corresponding to the high porosity of the AAO membrane used. The diameter of the beta-In(2)S(3) nanowires is about 60 nm with the length of about 6-8 mum. Moreover, the aspect ratio of beta-In(2)S(3) nanowires is up to 117. An EDS analysis revealed the beta-In(2)S(3) nanowires with an atomic ratio of nearly S/In = 1.5. X-ray diffraction and corresponding selected area electron diffraction patterns demonstrated that the beta-In(2)S(3) nanowire is tetragonal polycrystalline. The direct band gap energy (E(g)) is 2.40 eV from the optical measurement, and it is reasonable with literature.

beta. and. gamma. -comparative dose estimates on Enewetak Atoll

Energy Technology Data Exchange (ETDEWEB)

Crase, K.W.; Gudiksen, P.H.; Robison, W.L. (California Univ., Livermore (USA). Lawrence Livermore National Lab.)

1982-05-01

Enewetak Atoll in the Pacific is used for atmospheric testing of U.S. nuclear weapons. Beta dose and ..gamma..-ray exposure measurements were made on two islands of the Enewetak Atoll during July-August 1976 to determine the ..beta.. and low energy ..gamma..-contribution to the total external radiation doses to the returning Marshallese. Measurements were made at numerous locations with thermoluminescent dosimeters (TLD), pressurized ionization chambers, portable NaI detectors, and thin-window pancake GM probes. Results of the TLD measurements with and without a ..beta..-attenuator indicate that approx. 29% of the total dose rate at 1 m in air is due to ..beta..- or low energy ..gamma..-contribution. The contribution at any particular site, however, is reduced by vegetation. Integral 30-yr external shallow dose estimates for future inhabitants were made and compared with external dose estimates of a previous large scale radiological survey. Integral 30-yr shallow external dose estimates are 25-50% higher than whole body estimates. Due to the low penetrating ability of the ..beta..'s or low energy ..gamma..'s, however, several remedial actions can be taken to reduce the shallow dose contribution to the total external dose.

Interactions between two beta-sheets. Energetics of beta/beta packing in proteins.

Science.gov (United States)

Chou, K C; Némethy, G; Rumsey, S; Tuttle, R W; Scheraga, H A

1986-04-20

The analysis of the interactions between regularly folded segments of the polypeptide chain contributes to an understanding of the energetics of protein folding. Conformational energy-minimization calculations have been carried out to determine the favorable ways of packing two right-twisted beta-sheets. The packing of two five-stranded beta-sheets was investigated, with the strands having the composition CH3CO-(L-Ile)6-NHCH3 in one beta-sheet and CH3CO-(L-Val)6-NHCH3 in the other. Two distinct classes of low-energy packing arrangements were found. In the class with lowest energies, the strands of the two beta-sheets are aligned nearly parallel (or antiparallel) with each other, with a preference for a negative orientation angle, because this arrangement corresponds to the best complementary packing of the two twisted saddle-shaped beta-sheets. In the second class, with higher interaction energies, the strands of the two beta-sheets are oriented nearly perpendicular to each other. While the surfaces of the two beta-sheets are not complementary in this arrangement, there is good packing between the corner of one beta-sheet and the interior part of the surface of the other, resulting in a favorable energy of packing. Both classes correspond to frequently observed orientations of beta-sheets in proteins. In proteins, the second class of packing is usually observed when the two beta-sheets are covalently linked, i.e. when a polypeptide strand passes from one beta-sheet to the other, but we have shown here that a large contribution to the stabilization of this packing arrangement arises from noncovalent interactions.

β-ray scintillation survey meter for small-sized pipes

International Nuclear Information System (INIS)

Yamano, Toshiya; Suzuki, Toshikazu; Yoshida, Yoshiteru; Higashidate, Takamichi; Yonemura, Kenji; Fujita, Michio.

1990-01-01

The outer surface of the small-sized pipes used as scaffolding is measured by beta/gamma survey meter when they are carried out from the controlled area in nuclear facilities. But, the measurement of the radioactive contamination on the inner surface, when it is needed, is done indirectly using the smear method. To improve these vexatious works, Fuji Electric Co., Ltd. and Chubu Electric Power Co., Inc. jointly developed a beta-ray scintillation survey meter which, when inserted directly into pipes, can detect radioactive contamination on the inner surface. This detector is made of cylindrical plastic scintillator and it can measure low energy beta-ray by using the coincidence method which reduces random noise. A field test carried out with this prototype survey meter brought favorable results for designing its final version. (author)

Interaction with beta-arrestin determines the difference in internalization behavor between beta1- and beta2-adrenergic receptors.

Science.gov (United States)

Shiina, T; Kawasaki, A; Nagao, T; Kurose, H

2000-09-15

The beta(1)-adrenergic receptor (beta(1)AR) shows the resistance to agonist-induced internalization. As beta-arrestin is important for internalization, we examine the interaction of beta-arrestin with beta(1)AR with three different methods: intracellular trafficking of beta-arrestin, binding of in vitro translated beta-arrestin to intracellular domains of beta(1)- and beta(2)ARs, and inhibition of betaAR-stimulated adenylyl cyclase activities by beta-arrestin. The green fluorescent protein-tagged beta-arrestin 2 translocates to and stays at the plasma membrane by beta(2)AR stimulation. Although green fluorescent protein-tagged beta-arrestin 2 also translocates to the plasma membrane, it returns to the cytoplasm 10-30 min after beta(1)AR stimulation. The binding of in vitro translated beta-arrestin 1 and beta-arrestin 2 to the third intracellular loop and the carboxyl tail of beta(1)AR is lower than that of beta(2)AR. The fusion protein of beta-arrestin 1 with glutathione S-transferase inhibits the beta(1)- and beta(2)AR-stimulated adenylyl cyclase activities, although inhibition of the beta(1)AR-stimulated activity requires a higher concentration of the fusion protein than that of the beta(2)AR-stimulated activity. These results suggest that weak interaction of beta(1)AR with beta-arrestins explains the resistance to agonist-induced internalization. This is further supported by the finding that beta-arrestin can induce internalization of beta(1)AR when beta-arrestin 1 does not dissociate from beta(1)AR by fusing to the carboxyl tail of beta(1)AR.

Study and industrial applications of the external slowing-down {beta}{sup -} radiation of the yttrium - 90; Etude et applications industrielles du rayonnement de freinage externe des {beta}{sup -} de l'yttrium - 90

Energy Technology Data Exchange (ETDEWEB)

Leveque, P; Martinelli, P; Chauvin, R [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1955-07-01

Inelastic scattering of the {beta}{sup -} particles on the nucleus gives place to the emission of a X-ray Bremsstrahlung radiation. In view of possible industrial applications, we studied the slowing-down radiation of {sup 90}(Sr + Y) sources in various materials. This pure {beta}{sup -} emitter of long period is in the fission products of uranium. Among of the industrial applications, these sources of weak X-rays energy can be used for the radiography of thin pieces, for measuring the thickness, or for the analysis by fluorescence. (M.B.) [French] La diffusion inelastique des particules {beta}{sup -} sur les noyaux donne lieu a l'emission d'un rayonnement X de freinage. En vue de possibles applications industrielles, nous avons etudie le rayonnement de freinage des sources {sup 90}(Sr + Y) dans divers materiaux. Cet emetteur {beta}{sup -} pur a longue periode se trouve dans les produits de fission de l'uranium. Parmi les applications industrielles a l'etude, ces sources de rayons X de faible energie peuvent etre utilisees pour la radiographie de pieces minces, la mesure d'epaisseurs, ou encore pour l'analyse par fluorescence. (M.B.)

Realisation of a {beta} spectrometer solenoidal and a double {beta} spectrometer at coincidence; Realisation d'un spectrometre {beta} solenoidal et d'un double spectrometre {beta} a coincidence

Energy Technology Data Exchange (ETDEWEB)

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

1955-06-15

The two spectrometers have been achieved to tackle numerous problems of nuclear spectrometry. They possess different fields of application that complete themselves. The solenoidal spectrometer permits the determination of the energy limits of {beta} spectra and of their shape; it also permits the determination of the coefficients of internal conversion and reports {alpha}{sub K} / {alpha}{sub L} and it is especially efficient for the accurate energy levels of the {gamma} rays by photoelectric effect. The double coincidence spectrometer has been conceived to get a good efficiency in coincidence: indeed, the sum of the solid angles used for the {beta} and {gamma} emission is rather little lower to 4{pi} steradians. To get this efficiency, one should have sacrificed a little the resolution that is lower to the one obtained with the solenoidal spectrometer for a same brightness. Each of the elements of the double spectrometer can also be adapted to the study of angular correlations {beta}{gamma} and e{sup -}{gamma}. In this use, it is superior to the thin magnetic lens used up to here. The double spectrometer also permits the survey of the coincidences e{sup -}e{sup -}, e{sup -}{beta} of a equivalent way to a double lens; it can also be consider some adaptation for the survey of the angular correlations e{sup -}e{sup -}, e{sup -}{beta}. Finally, we applied the methods by simple spectrometry and by coincidence spectrometry, to the study of the radiances of the following radioelements: {sup 76}As (26 h), {sup 122}Sb (2,8 j), {sup 124}Sb (60 j), {sup 125}Sb (2,7 years). (M.B.) [French] Les deux spectrometres qui ont ete realises permettent d'aborder un grand nombre de problemes de spectrometrie nucleaire. Ils possedent des champs d'application tres differents qui se completent. Le spectrometre solenoidal permet la determination des energies limites des spectres {beta} et de leur forme; il permet aussi la determination des coefficients de conversion interne et des rapports

Extração, estruturas e propriedades de alfa- e beta-quitina

OpenAIRE

Campana-Filho,Sergio P.; Britto,Douglas de; Curti,Elisabete; Abreu,Fernanda R.; Cardoso,Marcia B.; Battisti,Marcos V.; Sim,Priscilla C.; Goy,Rejane C.; Signini,Roberta; Lavall,Rodrigo L.

2007-01-01

The fact that alpha- and beta-chitin adopt different arrays in the solid state is explored to emphasize their different properties and distinct spectral characteristics and X ray diffraction patterns. The methods for their extraction from the biomass in view of the preservation of their native structures and aiming to fulfill the claims of purity and uniformity for potential applications are discussed. The different arrays adopted by alpha- and beta-chitin also result in distinct reactivities...

Beta dose due to monazite sands of Kerala

International Nuclear Information System (INIS)

Massand, O.P.; Venkataraman, G.; Dhairyawan, M.P.

1977-01-01

The heavy black mineral sands of the sea coast of Kerala in India contain patches of monazite in concentrations varying between 0.5 to 5%. Monazite contains about 9.5% of thorium oxide (ThO 2 ) and 0.35% of uranium oxide (U 3 O 8 ). The high natural background radiation of this area had been a matter of concern and reports on the measured gamma radiation levels have appeared. The dose contribution due to beta rays emitted by the materials in the sand has been calculated using Loevinger's formula. The annual beta dose is of the order of 4200 mrad and 740 mrad at a height of 5 and 200 cm respectively from ground level. (author)

Measurement of relative L X-ray intensity ratio following radioactive decay and photoionization

Energy Technology Data Exchange (ETDEWEB)

Yalcin, P. [Department of Science Education, Faculty of Education, Erzincan University, 24030 Erzincan (Turkey)], E-mail: pasayalcin@hotmail.com; Porikli, S.; Kurucu, Y.; Sahin, Y. [Department of Physics, Faculty of Sciences, Atatuerk University, 25240 Erzurum (Turkey)

2008-05-22

The measurements of the L X-ray intensity ratio I(L{alpha})/I(L{beta}), I(L{alpha})/I(L{gamma}), I(L{alpha})/I(L{iota}), I(L{beta})/I(L{gamma}) and I(L{iota})/I(L{gamma}) for elements Dy, Ho, Yb, W, Hg, Tl and Pb were experimentally determined both by photon excitation, in which 59.5 keV {gamma}-rays from a filtered radioisotope {sup 241}Am was used, and by the radioactive decay of {sup 160}Tb, {sup 160}Er, {sup 173}Lu, {sup 182}Re, {sup 201}Tl, {sup 203}Pb and {sup 207}Bi. L X-rays emitted by samples were counted by a Si(Li) detector with resolution 160 eV at 5.9 keV. Obtained values were compared with the calculated theoretical values. Theoretical values of the I(L{alpha}/L{beta}), I(L{alpha}/L{gamma}), I(L{alpha}/L{iota}), I(L{beta}/L{gamma}) and I(L{iota}/L{gamma}) intensity ratios were calculated using theoretically tabulated values of subshell photoionization cross-section, fluorescence yield, fractional X-ray emission rates, Coster-Kronig transition probabilities. It was observed that present values agree with previous theoretical and other available experimental results.

High Sensitivity Detection of Xe Isotopes Via Beta-Gamma Coincidence Counting

International Nuclear Information System (INIS)

Bowyer, Ted W.; McIntyre, Justin I.; Reeder, Paul L.

1999-01-01

Measurement of xenon fission product isotopes is a key element in the global network being established to monitor the Comprehensive Nuclear-Test-Ban Treaty. Pacific Northwest National Laboratory has developed an automated system for separating Xe from air which includes a beta-gamma counting system for 131mXe, 133mXe, 133Xe, and 135Xe. Betas and conversion electrons are detected in a plastic scintillation cell containing the Xe sample. The counting geometry is nearly 100% for beta and conversion electrons. The resolution in the pulse height spectrum from the plastic scintillator is sufficient to observe distinct peaks for specific conversion electrons. Gamma and X-rays are detected in a NaI(Tl) scintillation detector which surrounds the plastic scintillator sample cell. Two-dimensional pulse height spectra of gamma energy versus beta energy are obtained. Each of the four xenon isotopes has a distinctive signature in the two-dimensional energy array. The details of the counting system, examples of two-dimensional beta-gamma data, and operational experience with this counting system will be described

Beta and gamma decay heat measurements between 0.1s--50,000s for neutron fission of 235U, 238U and 239Pu

International Nuclear Information System (INIS)

Schier, W.A.; Couchell, G.P.

1993-01-01

A helium-jet/tape-transport system is employed in the study of beta-particle and gamma-ray energy spectra of aggregate fission products as a function of time after fission. During the initial nine months of this project we have investigated the following areas: Design, assembly and characterization of a beta-particle spectrometer; Measurement of 235 U(n th ff) beta spectra for delay times 0.2 s to 12,000 s; Assembly and characterization of a 5 x 5 Nal(Tl) gamma-ray spectrometer; Measurement of 235 U(n th ff) gamma-ray spectra for delay times 0.2s to 1 5,500s; Assembly and characterization of HPGe gamma-ray spectrometer with a Nal(Tl) Compton-and-background-suppression annulus; Measurement of 235 U(n th ,ff) high-resolution gamma-ray spectra for delay times 0.6 s to over 100,000 s; Comparison of individual gamma-line intensities with ENDF/B-VI; Adaptation to our computer of unfolding program FERDO for beta and gamma aggregate fission-product energy spectra and development of a spectrum-stripping program for analysis of HPGe gamma-ray spectra; Study of the helium-jet fission-fragment elemental transfer efficiency. This work has resulted in the publication of twelve BAPS abstracts of presentations at scientific meetings. There are currently four Ph.D. and two M.S. candidates working on dissertations associated with the project

$\\beta$-decay studies using total absorption techniques some recent results

CERN Document Server

Algora, A; García-Borge, M J; Cano-Ott, D; Collatz, R; Courtin, S; Dessagne, P; Fraile-Prieto, L M; Gadea, A; Gelletly, W; Hellström, M; Janas, Z; Jungclaus, A; Karny, M; Kirchner, R; Maréchal, F; Miehé, C; Moroz, F; Nacher, E; Poirier, E; Roeckl, E; Rubio, B; Rykaczewski, K; Scornet, G L; Taín, J L; Tengblad, O; Wittmann, V

2004-01-01

$\\beta$-decay experiments, are a primary source of information for nuclear structure studies and at the same time complementary to in-beam investigations far from stability. Although both types of experiment are mainly based on $\\gamma$-ray spectroscopy, they face different experimental problems. The so-called $\\textit{Pandemonium effect}$ is a critical problem in $\\beta$-decay. In this contribution we will present a solution to this problem using total absorption spectroscopy methods. We will also present some examples of experiments carried out with the total absorption spectrometers TAS at GSI and Lucrecia recently installed at CERN. (25 refs).

Beta-decay studies using total absorption techniques: some recent results

Energy Technology Data Exchange (ETDEWEB)

Algora, A.; Rubio, B.; Nacher, E.; Cano O, D.; Tain, J.L.; Gadea, A. [lnstituto de Fisica Corpuscular, Apartado Oficial 22085, 46071 Valencia (Spain); Batist, L.; Moroz, F.; Wittmann, V. [St. Petersburg Nuclear Physics Institute, RU-188-350 Gatchina, (Russian Federation); Borge, M.J.G.; Jungclaus, A.; Tengblad, O. [Instituto Estructura de la Materia, E-28006 Madrid (Spain); Collatz, R.; Hellstrom, M.; Kirchner, R.; Roeckl, E. [Gesellschaft fur Schwerionenforschung, D-64291 Darmstadt (Germany); Courtin, H.; Dessagne, Ph.; Miehe, C.; Marechal, F.; Poirier, E. [lnstitut de Recherches Subatomiques, IN2P3-CNRS, F-67037 Strassbourg Cedex 2 (France); Fraile, L.M. [ISOLDE, Division EP, CERN, CH-1211 Geneva (Switzerland); Gelletly, W. [University of Surrey, Guildford GU2 7XH (United Kingdom); Janas, Z.; Karny, M.; Rykaczewski, K. [University of Warsaw, PL-00-681, Warsaw (Poland); Le Scornet, G. [CSNSM, 91405 Orsay (France)

2004-12-01

Beta-decay experiments are a primary source of information for nuclear structure studies and at the same time complementary to in-beam investigations far from stability. Although both types of experiment are mainly based on {gamma} ray spectroscopy, they face different experimental problems. The so called Pandemonium effect [1] is a critical problem in {beta}-decay. In this contribution we will present a solution to this problem using total absorption spectroscopy methods. We will also present some examples of experiments carried out with the total absorption spectrometers TAS at GSI and Lucrecia recently installed at CERN. (Author) 25 refs., 4 figs.

Sequence swapping does not result in conformation swapping for the beta4/beta5 and beta8/beta9 beta-hairpin turns in human acidic fibroblast growth factor.

Science.gov (United States)

Kim, Jaewon; Lee, Jihun; Brych, Stephen R; Logan, Timothy M; Blaber, Michael

2005-02-01

The beta-turn is the most common type of nonrepetitive structure in globular proteins, comprising ~25% of all residues; however, a detailed understanding of effects of specific residues upon beta-turn stability and conformation is lacking. Human acidic fibroblast growth factor (FGF-1) is a member of the beta-trefoil superfold and contains a total of five beta-hairpin structures (antiparallel beta-sheets connected by a reverse turn). beta-Turns related by the characteristic threefold structural symmetry of this superfold exhibit different primary structures, and in some cases, different secondary structures. As such, they represent a useful system with which to study the role that turn sequences play in determining structure, stability, and folding of the protein. Two turns related by the threefold structural symmetry, the beta4/beta5 and beta8/beta9 turns, were subjected to both sequence-swapping and poly-glycine substitution mutations, and the effects upon stability, folding, and structure were investigated. In the wild-type protein these turns are of identical length, but exhibit different conformations. These conformations were observed to be retained during sequence-swapping and glycine substitution mutagenesis. The results indicate that the beta-turn structure at these positions is not determined by the turn sequence. Structural analysis suggests that residues flanking the turn are a primary structural determinant of the conformation within the turn.

Current status of personnel monitoring for beta particles

International Nuclear Information System (INIS)

Plato, P.; Miklos, J.

1983-01-01

From 1975 to 1982, a concerted effort was made to develop a uniform procedure to test the performance of personnel dosimetry processors throughout the United States. The heart of this effort is a standard developed by the Health Physics Society Standards Committee (HPSSC) and adopted by the American National Standards Institute (ANSI) as ANSI N13.11-1982. The US Nuclear Regulatory Commission (NRC) sponsored a five year pilot study of this Standard which included three trial tests in which approximately 80 dosimetry processors participated. The Standard has made several contributions to the art and science of personnel monitoring for beta particles. First, the Standard defines test categories for beta particles and mixtures of beta particles plus gamma rays in addition to test categories for other types of radiation. Second, it defines a reference beta-particle source for test purposes. Third, it provides test criteria which are used to determine acceptable performance by a processor. The pilot study provided information on the state of the art of personnel monitoring within the bounds of the Standard. In addition, since the pilot study was advertised as the forerunner of a future mandatory certification program for dosimetry processors throughout the United States, considerable attention was given to personnel monitoring in general, and beta particles in particular. This paper discusses specific contibutions of the HPSSC/ANSI Standard and the pilot study to beta-particle dosimetry. The results of the three tests of the pilot study are summarized. The paper also amplifies on the needs to define the monitoring particle sources clearly

KATRIN :a New Beta-Spectroscopic Experiment to Determine the Neutrino Mass

Czech Academy of Sciences Publication Activity Database

Dragoun, Otokar

2007-01-01

Roč. 958, - (2007), s. 193-196. ISBN 978-0-7354-0472-4. ISSN N R&D Projects: GA MŠk LC07050 Institutional research plan: CEZ:AV0Z10480505 Keywords : neutrino mass * beta ray spectroscopy Subject RIV: BE - Theoretical Physics

Structural characterization of inclusion complex of hesperidin methyl chalcone and hydroxypropyl-beta-cyclodextrin

International Nuclear Information System (INIS)

Li, Y.; Li, F.; Chen, X.; Shen, W.

2016-01-01

Hesperidin methyl chalcone (HMC) was a semisynthetic derivative of hesperidin, which owned antiviral and antimicrobial activities. Owing these properties, it can be applied in pharmaceutical industry. However low stability had become a barrier to its application. In order to overcome this problem, an inclusion complex of hesperidin methyl chalcone and hydroxypropyl-beta-cyclodextrin (HP-beta-CD) were prepared by freeze-drying, using some analytical techniques to characterize the inclusion complex, including ultraviolet-visible spectroscopy (UV), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), X-ray diffractometry (XRD) and differential scanning calorimetry (DSC). The results of these analytical techniques indicated that the hesperidin methyl chalcone has been dispersed completely in the HP-beta-CD without a new compound formed, but entrapped inside the cavity of HP-beta-CD. (author)

Expression of transforming growth factor beta (TGF beta) receptors and expression of TGF beta 1, TGF beta 2 and TGF beta 3 in human small cell lung cancer cell lines

DEFF Research Database (Denmark)

Damstrup, L; Rygaard, K; Spang-Thomsen, M

1993-01-01

A panel of 21 small cell lung cancer cell (SCLC) lines were examined for the presence of Transforming growth factor beta receptors (TGF beta-r) and the expression of TGF beta mRNAs. By the radioreceptor assay we found high affinity receptors to be expressed in six cell lines. scatchard analysis......(r) = 65,000 and 90,000 and the betaglycan (type III) with M(r) = 280,000. Northern blotting showed expression of TGF beta 1 mRNA in ten, TGF beta 2 mRNA in two and TGF beta 3 mRNA in seven cell lines. Our results provide, for the first time, evidence that a large proportion of a broad panel of SCLC cell...... lines express TGF beta-receptors and also produce TGF beta mRNAs....

Purification, crystallization and preliminary X-ray analysis of a thermostable glycoside hydrolase family 43 beta-xylosidase from Geobacillus thermoleovorans IT-08

NARCIS (Netherlands)

Rohman, Ali; van Oosterwijk, Niels; Kralj, Slavko; Dijkhuizen, Lubbert; Dijkstra, Bauke W.; Puspaningsih, Ni Nyoman Tri

2007-01-01

The main enzymes involved in xylan-backbone hydrolysis are endo-1,4-beta-xylanase and beta-xylosidase. beta-Xylosidase converts the xylo-oligosaccharides produced by endo-1,4-beta-xylanase into xylose monomers. The beta-xylosidase from the thermophilic Geobacillus thermoleovorans IT-08, a member of

Beta decay of 72Co and excited levels in 72Ni

International Nuclear Information System (INIS)

Grzywacz, R.; Rykaczewski, K.; Sawicka, M.; Pfuetzner, M.; Daugas, J.M.; Belier, G.; Sauvestre, J.E.; Meot, V.; Roig, O.; Giovinazzo, J.; Grawe, H.; Mayet, P.; Matea, I.; Georgiev, G.; Lewitowicz, M.; Olivieira, F. de; Stodel, C.; Saint-Laurent, M. G.; Stanoiu, M.; Verney, D.

2003-01-01

An experiment was performed at GANIL to observe isomeric- and beta-delayed gamma rays from very neutron-rich nuclei around 74Ni. Fragmentation products of the 86Kr beam at 58 AMeV were studied using new devices: the LISE 2000 spectrometer and detectors from the EXOGAM germanium array. The primary aim of the experiment was to find the 8+ microsecond isomer in 76Ni and to perform beta decay spectroscopy of Co nuclei. We have successfully measured the beta delayed gammas from the decay of 72Co to 72Ni. The energies for the lowest excited states in 72Ni are proposed, with the first 2+ state at 1096 keV. These findings suggest a solution of the problem of the disappearance of the 8+ isomer in 72Ni. We also measured beta decay of other neutron-rich Co isotopes including 70Co. First evidence was found for a new short lived isomer, most likely the Iπ=8+ state, in 76Ni

Dual energy x-ray absorptiometry (DEXA) in the assessment of liver iron in patients with beta thalassaemia major

International Nuclear Information System (INIS)

Chatterton, B.E.; Thomas, C.M.; Schultz, C.G.

2000-01-01

Full text: Beta thalassaemia major is a condition in which anaemia from abnormal haemoglobin production causes bone marrow expansion and frequently reduced bone mineral density. These patients have a chronic requirement for transfusion which results in tissue iron overload which may cause organ damage. Increased X-ray attenuation in the liver was noted in patients undergoing whole body DEXA for the assessment of bone density and it was assumed that this was related to liver iron stores. The aim of this study was to determine if useful information about liver iron could be obtained from these studies. Method: Using a Lunar DPXL, whole body scanning was performed in 16 patients (eight male) age 19-32 with Beta Thalassaemia. As well as calculating indices of total body composition, regions of interest were placed over the visualised liver. The 'bone mineral content' (BMC),g and bone mineral density (BMD),g/cm 2 were calculated over the liver regions, with the assumption that the calculation related to mineral in the region of interest. The results were compared with the serum ferritin as an indirect measure of body iron stores. Results showed a highly significant correlation (r=0.85) between 'BMD' in the liver region and ferritin. Conclusion: Despite the known difficulties with equating iron stores and ferritin, and possible confounders on liver density, such as fibrosis, the high correlation suggests that DEXA may have a place in the assessment of iron deposition, and be more cost effective than other technologies such as MRI and CT. Prospective studies with invasive measurements of liver iron will be needed to determine this. Copyright (2000) The Australian and New Zealand Society of Nuclear Medicine Inc

L{sub {iota}}, L{sub {alpha}}, L{sub {beta}} and L{sub {gamma}} X-ray fluorescence cross-sections of heavy elements for the exciting photons energy 38.18, 43.95, 50.21 and 59.5 keV

Energy Technology Data Exchange (ETDEWEB)

Bastug, Arif [Department of Physics Education, College of Education, Erzincan University, 24030 Erzincan (Turkey)], E-mail: abastug40@hotmail.com

2008-03-15

The cross-sections for the production of L{sub {iota}}, L{sub {alpha}}, L{sub {beta}} and L{sub {gamma}} X-ray fluorescence (XRF) in Er, Ta, W, Au, Hg, Tl, Pb and Bi by photons with energies in the range 38-59.5 keV have been measured, using a standard doublereflection experimental set-up. Measurements have been performed using an annular 241 Am primary source and X-ray emitting secondary-exciter system. Experimental cross-sections have been compared with the theoretically calculated values of L X-ray cross-sections and fairly good agreement is observed between the experimental and theoretical values.

Primary 4{pi}{beta}-{gamma} coincidence system for standardization of radionuclides by means of plastic scintillators; Sistema primario por coincidencias 4{pi}{beta}-{gamma} para a padronizacao de radionuclideos empregando cintiladores plasticos

Energy Technology Data Exchange (ETDEWEB)

Baccarelli, Aida Maria

2003-07-01

The present work describes a 4{pi}({alpha},{beta})-{gamma} coincidence system for absolute measurement of radionuclide activity using a plastic scintillator in 4{pi} geometry for charged particles detection and a Nal (Tl) crystal for gamma-ray detection. Several shapes and dimensions of the plastic scintillator have been tried in order to obtain the best system configuration. Radionuclides which decay by alpha emission, {beta}{sup -}, {beta}{sup +} and electron capture have been standardized. The results showed excellent agreement with other conventional primary system which makes use of a 4{pi} proportional counter for X-ray and charged particle detection. The system developed in the present work have some advantages when compared with the conventional systems, namely; it does not need metal coating on the films used as radioactive source holders. When compared to liquid scintillators, is showed the advantage of not needing to be kept in dark for more than 24 h to allow phosphorescence decay of ambient light. Therefore it can be set to count immediately after the sources are placed inside of it. (author)

Glycation induces formation of amyloid cross-beta structure in albumin.

Science.gov (United States)

Bouma, Barend; Kroon-Batenburg, Loes M J; Wu, Ya-Ping; Brünjes, Bettina; Posthuma, George; Kranenburg, Onno; de Groot, Philip G; Voest, Emile E; Gebbink, Martijn F B G

2003-10-24

Amyloid fibrils are components of proteinaceous plaques that are associated with conformational diseases such as Alzheimer's disease, transmissible spongiform encephalopathies, and familial amyloidosis. Amyloid polypeptides share a specific quarternary structure element known as cross-beta structure. Commonly, fibrillar aggregates are modified by advanced glycation end products (AGE). In addition, AGE formation itself induces protein aggregation. Both amyloid proteins and protein-AGE adducts bind multiligand receptors, such as receptor for AGE, CD36, and scavenger receptors A and B type I, and the serine protease tissue-type plasminogen activator (tPA). Based on these observations, we hypothesized that glycation induces refolding of globular proteins, accompanied by formation of cross-beta structure. Using transmission electron microscopy, we demonstrate here that glycated albumin condensates into fibrous or amorphous aggregates. These aggregates bind to amyloid-specific dyes Congo red and thioflavin T and to tPA. In contrast to globular albumin, glycated albumin contains amino acid residues in beta-sheet conformation, as measured with circular dichroism spectropolarimetry. Moreover, it displays cross-beta structure, as determined with x-ray fiber diffraction. We conclude that glycation induces refolding of initially globular albumin into amyloid fibrils comprising cross-beta structure. This would explain how glycated ligands and amyloid ligands can bind to the same multiligand "cross-beta structure" receptors and to tPA.

Optimization of Plastic Scintillator Thicknesses for Online Beta Detection in Mixed Fields

Energy Technology Data Exchange (ETDEWEB)

Pourtangestani, K.; Machrafi, R. [University of Ontario Institute of Technology, Oshawa, ON (Canada)

2013-07-15

For efficient beta detection in a mixed beta-gamma field, Monte Carlo simulation models have been developed to optimize the thickness of a plastic scintillator used in whole body monitor. The simulation has been performed using MCNP/X code and different thicknesses of plastic scintillators ranging from 150 to 600 {mu}m have been used. The relationship between the thickness of the scintillator and the efficiency of the detector has been analysed. For 150 {mu}m thickness, an experimental investigation has been conducted with different beta sources at different positions on the scintillator and the counting efficiency of the unit has been measured. Evaluated data along with experimental ones have been discussed. A thickness of 300 {mu}m to 500 {mu}m has been found to be an optimum thickness for better beta detection efficiency in the presence of low energy gamma ray. (author)

Beta-energy averaging and beta spectra

International Nuclear Information System (INIS)

Stamatelatos, M.G.; England, T.R.

1976-07-01

A simple yet highly accurate method for approximately calculating spectrum-averaged beta energies and beta spectra for radioactive nuclei is presented. This method should prove useful for users who wish to obtain accurate answers without complicated calculations of Fermi functions, complex gamma functions, and time-consuming numerical integrations as required by the more exact theoretical expressions. Therefore, this method should be a good time-saving alternative for investigators who need to make calculations involving large numbers of nuclei (e.g., fission products) as well as for occasional users interested in restricted number of nuclides. The average beta-energy values calculated by this method differ from those calculated by ''exact'' methods by no more than 1 percent for nuclides with atomic numbers in the 20 to 100 range and which emit betas of energies up to approximately 8 MeV. These include all fission products and the actinides. The beta-energy spectra calculated by the present method are also of the same quality

Effects of beta/gamma radiation on nuclear waste glasses

Energy Technology Data Exchange (ETDEWEB)

Weber, W.J. [Pacific Northwest National Lab., Richland, WA (United States)

1997-07-01

A key challenge in the disposal of high-level nuclear waste (HLW) in glass waste forms is the development of models of long-term performance based on sound scientific understanding of relevant phenomena. Beta decay of fission products is one source of radiation that can impact the performance of HLW glasses through the interactions of the emitted {beta}-particles and g-rays with the atoms in the glass by ionization processes. Fused silica, alkali silicate glasses, alkali borosilicate glasses, and nuclear waste glasses are all susceptible to radiation effects from ionization. In simple glasses, defects (e.g., non-bridging oxygen and interstitial molecular oxygen) are observed experimentally. In more complex glasses, including nuclear waste glasses, similar defects are expected, and changes in microstructure, such as the formation of bubbles, have been reported. The current state of knowledge regarding the effects of {beta}/{gamma} radiation on the properties and microstructure of nuclear waste glasses are reviewed. (author)

Measurement of relative intensities of L-shell x-rays in some high-Z elements

Energy Technology Data Exchange (ETDEWEB)

Kumar, S; Mittal, R; Allawadhi, K L; Sood, B S [Punjabi Univ., Patiala (India). Nuclear Science Labs.

1982-10-14

The L-shell x-ray relative intensities I(Lsub(..cap alpha..))/I(Lsub(l)),I(Lsub(..cap alpha..))/I(Lsub(..beta..)) and I(Lsub(..cap alpha..))/I(Lsub(..gamma..)) for U, Th, Pb and ratios I(Lsub(..cap alpha..+l))/I(Lsub(..beta..)) and I(Lsub(..cap alpha..+l))/I(Lsub(..gamma..)) for W have been measured. The L-shell electrons are excited by 59.57 keV gamma rays from /sup 241/Am and the fluorescent L-shell x-ray intensities are measured with a Si(Li) detector. The experimental results are found to agree well with theory.

beta- and gamma-Comparative dose estimates on Eniwetok Atoll

Energy Technology Data Exchange (ETDEWEB)

Crase, K.W.; Gudiksen, P.H.; Robison, W.L.

1982-05-01

Eniwetok Atoll is one of the Pacific atolls used for atmospheric testing of U.S. nuclear weapons. Beta dose and gamma-ray exposure measurements were made on two islands of the Eniwetok Atoll during July-August 1976 to determine the beta and low energy gamma-contribution to the total external radiation doses to the returning Marshallese. Measurements were made at numerous locations with thermoluminescent dosimeters (TLD), pressurized ionization chambers, portable NaI detectors, and thin-window pancake GM probes. Results of the TLD measurements with and without a beta-attenuator indicate that approx. 29% of the total dose rate at 1 m in air is due to beta- or low energy gamma-contribution. The contribution at any particular site, however, is somewhat dependent on ground cover, since a minimal amount of vegetation will reduce it significantly from that over bare soil, but thick stands of vegetation have little effect on any further reductions. Integral 30-yr external shallow dose estimates for future inhabitants were made and compared with external dose estimates of a previous large scale radiological survey (En73). Integral 30-yr shallow external dose estimates are 25-50% higher than whole body estimates. Due to the low penetrating ability of the beta's or low energy gamma's, however, several remedial actions can be taken to reduce the shallow dose contribution to the total external dose.

Scoparic acid A, a beta-glucuronidase inhibitor from Scoparia dulcis.

Science.gov (United States)

Hayashi, T; Kawasaki, M; Okamura, K; Tamada, Y; Morita, N; Tezuka, Y; Kikuchi, T; Miwa, Y; Taga, T

1992-12-01

The 70% EtOH extract of Scoparia dulcis showed inhibitory activity against beta-glucuronidase from bovine liver. Bioassay-directed fractionation of the active extract led to the isolation of three labdane-type diterpene acids, scoparic acid A [1] [6-benzoyl-12-hydroxy-labda-8(17), 13-dien-18-oic acid], scoparic acid B [2] [6-benzoyl-14,15-dinor-13-oxo-8(17)-labden-18-oic acid], and scoparic acid C [3] [6-benzoyl-15-nor-14-oxo-8(17)-labden-18-oic acid], the structures of which were established by spectral means, including X-ray analysis. Scoparic acid A was found to be a potent beta-glucuronidase inhibitor.

Speculative Betas

OpenAIRE

Harrison Hong; David Sraer

2012-01-01

We provide a model for why high beta assets are more prone to speculative overpricing than low beta ones. When investors disagree about the common factor of cash-flows, high beta assets are more sensitive to this macro-disagreement and experience a greater divergence-of-opinion about their payoffs. Short-sales constraints for some investors such as retail mutual funds result in high beta assets being over-priced. When aggregate disagreement is low, expected return increases with beta due to r...

Differential diagnosis of inflammatory lung affections by x-ray in children

Energy Technology Data Exchange (ETDEWEB)

Faerber, D.

1980-01-01

As a consequence of the rise in neonatal infections by ..beta..-streptococci the clinical respiratory distress syndrome in neonates is becoming increasingly important for differential diagnosis. The present paper reports on special problems in differential X-ray diagnosis of ..beta..-streptococcus pneumonia as compared to inflammatory lung affections attributable to various causes.

Mass measurement project by determination of Q{sub {beta}} for neutron-rich nuclei; Projet de mesure des masses par determination des Q{sub {beta}} pour des noyaux tres riches en neutrons

Energy Technology Data Exchange (ETDEWEB)

Pautrat, M; Lagrange, J M; Petizon, L [Paris-11 Univ., 91 - Orsay (France). Inst. de Physique Nucleaire; Vanhorenbeeck, J; Duhamel, P [Brussels Univ. (Belgium). Inst. d` Astronomie et d` Astrophysique; Binon, F [Universite Libre de Bruxelles (Belgium)

1994-12-31

The aim of the project described hereafter is to collect new data on the exotic neutron rich nuclei of the Fe to Zn region, and in particular to determine their masses, for both nuclear physics and astrophysics purposes. These isotopes will be produced through projectile fragmentation at the GANIL facility and selected by the LISE3 spectrometer. Their half-lives will be measured as well as the energy of their main {gamma} rays; {gamma} - {gamma} coincidences will then allow to build a preliminary level scheme. The analysis of {beta} spectra and {beta} - {gamma} coincidences will finally provide the maximum {beta} decay energies of the studied nuclei leading to their masses. The difficulties arising from the low production rates, the {beta} detection, the data handling are discussed together with the solutions proposed to overcome them. (authors). 17 refs.

Study of multi-neutron emission in the $\\beta$-decay of $^{11}$Li

CERN Multimedia

A new investigation of neutron emission in the $\\beta$-decay of $^{11}$Li is proposed. The principal goal of this study will be to directly measure, for the first time for any system, two $\\beta$-delayed neutrons in coincidence and determine the energy and angular correlations. This will be possible using liquid scintillator detectors, capable of distinguishing between neutrons and ambient $\\gamma$ and cosmic-rays, coupled to a new digital electronics and acquisition system. In parallel, a considerably more refined picture of the single-neutron emission will be obtained.

Experiments close to the beta-limit in W7-AS

International Nuclear Information System (INIS)

Weller, A; Geiger, J; Werner, A; Zarnstorff, M C; Nuehrenberg, C; Sallander, E; Baldzuhn, J; Brakel, R; Burhenn, R; Dinklage, A; Fredrickson, E; Gadelmeier, F; Giannone, L; Grigull, P; Hartmann, D; Jaenicke, R; Klose, S; Knauer, J P; Koenies, A; Kolesnichenko, Ya I; Laqua, H P; Lutsenko, V V; McCormick, K; Monticello, D; Osakabe, M; Pasch, E; Reiman, A; Rust, N; Spong, D A; Wagner, F; Yakovenko, Yu V

2003-01-01

A major objective of the experimental program in the last phase of the W7-AS stellarator was to explore and demonstrate the high-beta performance of advanced stellarators. MHD-quiescent discharges at low impurity radiation levels with volume averaged beta-values of up to beta=3.4% have been achieved. A very important prerequisite was the attainment of the high density H-Mode (HDH) regime. This was made possible by the installation of extensive graphite plasma facing components designed for island divertor operation. The co-directed neutral beam injection provided increased absorbed heating power of up to 3.2 MW in high-beta plasmas with B<=1.25 T. The anticipated improved features concerning equilibrium and stability at high plasma beta could be verified experimentally by the comparison of x-ray data with free boundary equilibrium calculations. The maximum beta found in configurations with a rotational transform around t=0.5 is determined by the available heating power. No evidence of a stability limit has been found in the accessible configuration space, and the discharges are remarkably quiescent at maximum beta, most likely due the increase of the magnetic well depth. An increase in low m/n MHD activity is typically observed during the transition towards high beta. The beneficial stability properties of net-current-free configurations could be demonstrated by comparison with configurations where a significant inductive current drive was involved. Current driven instabilities such as tearing modes and soft disruptions can prevent access to beta-values as high as in the currentless case. The experimental results indicate that optimized stellarators such as W7-X can be considered as a viable option for an attractive stellarator fusion reactor

Estimation of mineral concentration in bone samples by backscattering of beta-rays

International Nuclear Information System (INIS)

Meissner, J.; Marten, R.F.

1978-01-01

The method of using backscattered β-rays for the determination of density is used for the first time to measure the mineral concentration in specimens of bone and its usefulness as an aid in the diagnosis of osteopathies is investigated. The reliability of the technique is studied on the basis of methodical examinations employing model substances that are similar in composition to bone. For the geometry chosen for the measureing set-up, a calibration is carried out both for the determination of the effective atomic number and for the mineral concentration of measuring samples. The axial-symmetrical arrangement chose, permits the determination of the concentration to an accuracy of max. +-1% standard deviation. In agreement with computed deviations experiments confirm that with this set-up there is no dependence of the backscatter on sample density. After appropriate calibration, both mineral concentration and density can be measured in two suitable fixed positions of the beta source, sample and detector. The figure for mineral concentration calculated from the backscattering rates are compared with corresponding figure obtained with analytical chemical determinations. It can be seen that two methods have a high degree of agreement. The backscatter method seems to have the advantage of simplicity of the set-up that provides accurate results in thin specimens having a diameter of only 10 mm. With repect to measurements in bone, however, the method is limited to biopsy specimens obtained from compact bone. In such samples, however, both the absolute figure for mineral concentration can be determined and also its local variation in large parts of the skeleton examined. From the mineral concentration and density, the mineral content of the bone substance is computed; this provides differential diagnostic information on osteopathic conditions. (orig.) [de

Beta radiation effects in sup 1 sup 3 sup 7 Cs-substituted pollucite

CERN Document Server

Hess, N J; Conradson, S D; Weber, W J

2000-01-01

The effect of high-energy beta radiation on the long-range and local structure of sup 1 sup 3 sup 7 Cs-substituted CsAlSi sub 2 O sub 6 (pollucite) was studied by X-ray diffraction (XRD) and X-ray absorption spectroscopy (XAS) techniques at the Cs K-edge. Analysis of the XRD pattern of pollucite with an absorbed dose of 10 sup 1 sup 8 beta decays/g using Rietveld analysis indicates a 0.5-1% volume expansion of the tetrahedral structure as measured at 50 K and a minor displacement of the Cs cation toward the face of one of the six-membered rings. Analysis of the real-space pair-distribution function obtained from Fourier transformation of the diffraction pattern indicates significant correlated movement of the (Si,Al)-O pairs and large static disorder between Cs-O pairs. Analysis of the Cs K-edge XAS revealed substantial contributions from the Cs atomic X-ray absorption. This likely results from the exceedingly long Cs-O bond distances in the pollucite structure, which diminish the fine structure of the XAS os...

Evaluation of gamma-ray intensities

International Nuclear Information System (INIS)

Yoshizawa, Yasukazu; Inoue, Hikaru; Hoshi, Masaharu; Shizuma, Kiyoshi; Iwata, Yosei.

1980-04-01

Relative intensities and intensities per decay of gamma rays were evaluated for 16 nuclides, 22 Na, 24 Na, 46 Sc, 54 Mn, 60 Co, 85 Sr, 88 Y, 95 Nb, sup(108m)Ag, 134 Cs, 133 Ba, 139 Ce, sup(180m)Hf, 198 Au, 203 Hg and 207 Bi. For most of these nuclides disintegration rates can be determined by means of β-γ or X-γ coincidence method. Since decay schemes of these nuclides are established, intensities per decay of strong gamma rays were accurately evaluated by using weak beta-ray branching ratios, relative gamma-ray intensities and internal conversion coefficients. Half-lives of the nuclides were also evaluated. Use of the nuclides, therefore, are recommended for precision intensity calibration of the detectors. (author)

gamma-ray emission probabilities of sup 1 sup 9 sup 3 Os

CERN Document Server

Marnada, N; Ueda, N; Ikeda, K; Hayashi, N

2002-01-01

Precise measurements of disintegration rates by using a 4 pi beta-gamma coincidence apparatus have resulted in improved certainties of the principal gamma-ray emission probabilities of sup 1 sup 9 sup 3 Os. Most of the uncertainties are less than 1%, whereas the uncertainties of emission probabilities evaluated in the Nuclear Data Sheets (83 (1998) 921) are more than 6%. The precision is improved for the beta-ray branching ratio for direct transition to the ground state and the value is larger than the evaluated value by about 6%.

Labelling of. beta. -endorphin (. beta. -END) and. beta. -lipotropin (. beta. -LPH) by /sup 125/I

Energy Technology Data Exchange (ETDEWEB)

Deby-Dupont, G.; Joris, J.; Franchimont, P. (Universite de Liege (Belgique)); Reuter, A.M.; Vrindts-Gevaert, Y. (Institut des Radioelements, Fleurus (Belgique))

1983-01-01

5 ..mu..g of human ..beta..-endorphin were labelled with 2 mCi /sup 125/I by the chloramine T technique. After two gel filtrations on Sephadex G-15 and on Sephadex G-50 in phosphate buffer with EDTA, Trasylol and mercapto-ethanol, a pure tracer was obtained with a specific activity about 150 ..mu..Ci/..mu..g.Kept at + 4/sup 0/C, the tracer remained utilizable for 30 days without loss of immunoreactivity. The labelling with lactoperoxydase and the use of another gel filtration method (filtration on Aca 202) gave a /sup 125/I ..beta..-END tracer with the same immunoreactivity. The binding of this tracer to the antibody of an anti-..beta..-END antiserum diluted at 1/8000 was 32% with a non specific binding of 2%. 5 ..mu..g of human ..beta..-lipotropin were labelled with 0.5 mCi /sup 125/I by the lactoperoxydase method. After two gel filtrations on Sephadex G-25 and on Sephadex G-75 in phosphate buffer with EDTA, Trasylol and mercapto-ethanol, a pure tracer with a specific activity of 140 ..mu..Ci/..mu..g was obtained. It remained utilizable for 30 days when kept at + 4/sup 0/C. Gel filtration on Aca 202 did not give good purification, while gel filtration on Aca 54 was good but slower than on Sephadex G-75. The binding to antibody in absence of unlabelled ..beta..-LPH was 32% for an anti-..beta..-LPH antiserum diluted at 1/4000. The non specific binding was 2.5%.

Ionizing Radiation Promotes Migration and Invasion of Cancer Cells Through Transforming Growth Factor-Beta-Mediated Epithelial-Mesenchymal Transition

Energy Technology Data Exchange (ETDEWEB)

Zhou Yongchun [Department of Radiation Oncology, Xijing Hospital Fourth Military Medical University, Xi' an (China); Department of Radiation Medicine, College of Preventive Medicine, Xijing Hospital Fourth Military Medical University, Xi' an (China); Liu Junye; Li Jing; Zhang Jie [Department of Radiation Medicine, College of Preventive Medicine, Xijing Hospital Fourth Military Medical University, Xi' an (China); Xu Yuqiao [Department of Pathology, Xijing Hospital Fourth Military Medical University, Xi' an (China); Zhang Huawei; Qiu Lianbo; Ding Guirong [Department of Radiation Medicine, College of Preventive Medicine, Xijing Hospital Fourth Military Medical University, Xi' an (China); Su Xiaoming [Department of Radiation Oncology, 306th Hospital of PLA, Beijing (China); Mei Shi [Department of Radiation Oncology, Xijing Hospital Fourth Military Medical University, Xi' an (China); Guo Guozhen, E-mail: guozhenguo@hotmail.com [Department of Radiation Medicine, College of Preventive Medicine, Xijing Hospital Fourth Military Medical University, Xi' an (China)

2011-12-01

Purpose: To examine whether ionizing radiation enhances the migratory and invasive abilities of cancer cells through transforming growth factor (TGF-{beta})-mediated epithelial-mesenchymal transition (EMT). Methods and Materials: Six cancer cell lines originating from different human organs were irradiated by {sup 60}Co {gamma}-ray at a total dose of 2 Gy, and the changes associated with EMT, including morphology, EMT markers, migration and invasion, were observed by microscope, Western blot, immunofluorescence, scratch assay, and transwell chamber assay, respectively. Then the protein levels of TGF-{beta} in these cancer cells were detected by enzyme-linked immunosorbent assay, and the role of TGF-{beta} signaling pathway in the effect of ionizing radiation on EMT was investigate by using the specific inhibitor SB431542. Results: After irradiation with {gamma}-ray at a total dose of 2 Gy, cancer cells presented the mesenchymal phenotype, and compared with the sham-irradiation group the expression of epithelial markers was decreased and of mesenchymal markers was increased, the migratory and invasive capabilities were strengthened, and the protein levels of TGF-{beta} were enhanced. Furthermore, events associated with EMT induced by IR in A549 could be reversed through inhibition of TGF-{beta} signaling. Conclusions: These results suggest that EMT mediated by TGF-{beta} plays a critical role in IR-induced enhancing of migratory and invasive capabilities in cancer cells.

9-{beta}-arabinofuranosyladenine preferentially sensitizes radioresistant squamous cell carcinoma cell lines to x-rays

Energy Technology Data Exchange (ETDEWEB)

Heaton, D. [Rush Univ. Medical Center, Chicago, IL (United States). Therapeutic Radiology; Mustafi, R. [Chicago Univ., IL (United States). Dept. of Radiation and Cellular Oncology; Schwartz, J.L. [Chicago Univ., IL (United States). Dept. of Radiation and Cellular Oncology]|[Argonne National Lab., IL (United States)

1992-06-01

The effect of 9-{beta}-arabinofuranosyladenine (ara-A) on sensitivity to the deleterious effects of x-rays was studied in six squamous cell carcinoma cell lines. Three lines were relatively radioresistant, having D{sub 0} values of 2.31 to 2.89 Gy, and the other three lines were relatively radiosensitive, having D{sub 0} values of between 1.07 and 1.45 Gy. Ara-A (50 or 500 {mu}M) was added to cultures 30 min prior to irradiation and removed 30 min after irradiation, and sensitivity was measured in terms of cell survival. The radiosensitizing effect of ara-A was very dependent on the inherent radiosensitivity of the tumor cell line. Fifty micromolar concentrations of ara-A sensitized only the two most radioresistant lines, SCC-12B.2 and JSQ-3. Five hundred micromolar concentrations of ara-A sensitized the more sensitive cell lines, SQ-20B and SQ-9G, but failed to have any effect on the radiation response of the two most sensitive cell lines, SQ-38 and SCC-61. Concentrations of ara-A as low as 10 {mu}M were equally efficient in inhibiting DNA synthesis in all six cell lines. These results suggest that the target for the radiosensitizing effect of ara-A is probably related to the factor controlling the inherent radiosensitivity of human tumor cells. Therefore, ara-A might be useful in overcoming radiation resistance in vivo.

Energy response of graphite-mixed magnesium borate TLDs to low energy x-rays

DEFF Research Database (Denmark)

Pelliccioni, M.; Prokic, M.; Esposito, A.

1991-01-01

Graphite-mixed sintered magnesium borate TL dosemeters are attractive for beta/gamma dosimetry because they combine a low energy dependence to beta-rays with near tissue or air equivalence to photon irradiations and a high sensitivity. In this paper results from the experimental measurements...

A manual low background alpha beta counting system

Energy Technology Data Exchange (ETDEWEB)

Levison, S; German, U; Peled, O; Turgeman, S; Vangrovitz, U; Tirosh, D; Piestum, S; Assido, H [Israel Atomic Energy Commission, Beersheba (Israel). Nuclear Research Center-Negev

1996-12-01

An Alpha and Beta counting system consisting of a micro controller-based electronic unit and detectors assembly was developed. The radiation detection unit consists of two proportional detectors (a main detector and a cosmic-ray guard detector) which can be easily disassembled for decontamination or repair. The detectors are mounted in a manual operating sample changer shielded by 5 cm of lead. Simplicity of maintenance and functional operation were taken into consideration in the design. The electronic unit supplies the high voltage and enables the operational functions including controls anti alarms. Calculations of net cpm of Alpha and Beta counting are displayed and can be printed. RS-232 communication option enables connection to a computer and operation of more sophisticated programs for calculations and data storage in the future (authors).

A manual low background alpha beta counting system

International Nuclear Information System (INIS)

Levison, S.; German, U.; Peled, O.; Turgeman, S.; Vangrovitz, U.; Tirosh, D.; Piestum, S.; Assido, H.

1996-01-01

An Alpha and Beta counting system consisting of a micro controller-based electronic unit and detectors assembly was developed. The radiation detection unit consists of two proportional detectors (a main detector and a cosmic-ray guard detector) which can be easily disassembled for decontamination or repair. The detectors are mounted in a manual operating sample changer shielded by 5 cm of lead. Simplicity of maintenance and functional operation were taken into consideration in the design. The electronic unit supplies the high voltage and enables the operational functions including controls anti alarms. Calculations of net cpm of Alpha and Beta counting are displayed and can be printed. RS-232 communication option enables connection to a computer and operation of more sophisticated programs for calculations and data storage in the future (authors)

Synthesis of multi-walled carbon nanotubes/{beta}-FeOOH nanocomposites with high adsorption capacity

Energy Technology Data Exchange (ETDEWEB)

Song Haojie, E-mail: shj6922@163.com [School of Materials Science and Engineering, Jiangsu University (China); Liu Lei [Pharmaceutic College of Henan University (China); Jia Xiaohua; Min Chunying [School of Materials Science and Engineering, Jiangsu University (China)

2012-12-15

A hybrid nanostructure of multi-walled carbon nanotubes (CNTs) and {beta}-ferric oxyhydroxide ({beta}-FeOOH) nanoparticles is synthesized by ultrasonic-assisted in situ hydrolysis of the precursor ferric chloride and CNTs. Characterization by X-ray diffraction, scanning electron microscopy , and transmission electron microscopy establishes the nanohybrid structure of the synthesized sample. The results revealed that the surface of CNTs was uniformly assembled by numerous {beta}-FeOOH nanoparticles and had an average diameter of 3 nm. The formation route of anchoring {beta}-FeOOH nanoparticles onto CNTs was proposed as the intercalation and adsorption of iron ions onto the wall of CNTs, followed by the nucleation and growth of {beta}-FeOOH nanoparticles. The values of remanent magnetization (M{sub r}) and coercivity (H{sub c}) of the as-synthesized CNTs/{beta}-FeOOH nanocomposites were 0.1131 emu g, and 490.824 Oe, respectively. Furthermore, CNTs/{beta}-FeOOH nanocomposites showed a very high adsorption capacity of Congo red and thus these nanocomposites can be used as good adsorbents and can be used for the removal of the dye of Congo red from the waste water system.

High-resolution metallic magnetic calorimeters for {beta}-spectroscopy on {sup 187}rhenium and position resolved X-ray spectroscopy

Energy Technology Data Exchange (ETDEWEB)

Porst, Jan-Patrick

2011-02-01

This thesis describes the development of metallic magnetic calorimeters (MMCs) for high resolution spectroscopy. MMCs are energy dispersive particle detectors based on the calorimetric principle which are typically operated at temperatures below 100 mK. The detectors make use of a paramagnetic temperature sensor to transform the temperature rise upon the absorption of a particle in the detector into a measurable magnetic flux change in a dc-SQUID. The application of MMCs for neutrino mass measurements and their advantages with respect to other approaches are discussed. In view of this application the development of an MMC optimized for {beta}-endpoint spectroscopy on {sup 187}rhenium is presented. A fully micro-fabricated X-ray detector is characterized and performs close to design values. Furthermore, a new technique to more efficiently couple rhenium absorbers mechanically and thermally to the sensor was developed and successfully tested. By employing a metallic contact, signal rise times faster than 5 {mu}s could be observed with superconducting rhenium absorbers. In addition to the single pixel detectors, an alternative approach of reading out multiple pixels was developed in this work, too. Here, the individual absorbers have a different thermal coupling to only one temperature sensor resulting in a distribution of different pulse shapes. Straightforward position discrimination by means of rise time analysis is demonstrated for a four pixel MMC and a thermal model of the detector is provided. Unprecedented so far, an energy resolution of less than {delta}E{sub FWHM}<5 eV for 5.9 keV X-rays was achieved across all absorbers. (orig.)

A pulse synthesis of beta-FeSi sub 2 layers on silicon implanted with Fe sup + ions

CERN Document Server

Batalov, R I; Terukov, E I; Kudoyarova, V K; Weiser, G; Kuehne, H

2001-01-01

The synthesis of thin beta-FeSi sub 2 films was performed by means of the Fe sup + ion implantation into Si (100) and the following nanosecond pulsed ion treatment of implanted layer. Using the beta-FeSi sub 2 beta-FeSi sub 2 e X-ray diffraction it is shown that the pulsed ion treatment results in the generation of the mixture of two phases: FeSi and beta-FeSi sub 2 with stressed crystal lattices. The following short-time annealing leads to the total transformation of the FeSi phase into the beta-FeSi sub 2 one. The Raman scattering data prove the generation of the beta-FeSi sub 2 at the high degree of the silicon crystallinity. The experimental results of the optical absorption testify to the formation of beta-FeSi sub 2 layers and precipitates with the straight-band structure. The photoluminescence signal at lambda approx = 1.56 mu m observes up to 210 K

Design and production of sintered {beta}-tricalcium phosphate 3D scaffolds for bone tissue regeneration

Energy Technology Data Exchange (ETDEWEB)

Santos, Carlos F.L. [CICS-UBI - Centro de Investigacao em Ciencias da Saude, Universidade da Beira Interior, Covilha (Portugal); Silva, Abilio P. [Centro de Ciencia e Tecnologia Aeroespaciais, Universidade da Beira Interior, Covilha (Portugal); Lopes, Luis [CICS-UBI - Centro de Investigacao em Ciencias da Saude, Universidade da Beira Interior, Covilha (Portugal); Pires, Ines [Instituto de Engenharia Mecanica - Lisboa (IDMEC Lisboa/IST/UTL), Avenida Rovisco Pais, 1049-001 Lisboa (Portugal); Correia, Ilidio J., E-mail: icorreia@ubi.pt [CICS-UBI - Centro de Investigacao em Ciencias da Saude, Universidade da Beira Interior, Covilha (Portugal)

2012-07-01

The characteristics of sintered {beta}-tricalcium phosphate ({beta}-TCP) scaffolds produced by 3D printing were studied by means of X-ray diffraction, Scanning Electron Microscopy, Fourier transform infrared spectroscopy, uniaxial compression tests and cytotoxicity tests, using human osteoblast cells. The results reported include details of the {beta}-TCP scaffolds' porosity, density, phase stability, mechanical behavior and cytotoxic profile. Collectively, these properties are fundamental for the future application of these scaffolds as bone substitutes for individualized therapy. Highlights: Black-Right-Pointing-Pointer {beta}-Tricalcium phosphate ({beta}-TCP) 3D scaffolds were produced by rapid prototyping. Black-Right-Pointing-Pointer Scaffold properties were assessed by SEM, FTIR, XRD and by mechanical tests. Black-Right-Pointing-Pointer The cytotoxic profile of the scaffolds was characterized by in vitro assays. Black-Right-Pointing-Pointer Scaffolds have good properties for its application as bone substitutes for individualized therapy.

Assessment of affinities of beta-CIT, beta-CIT-FE, and beta-CIT-FP for monoamine transporters permanently expressed in cell lines

International Nuclear Information System (INIS)

Okada, Tomoya; Fujita, Masahiro; Shimada, Shoichi; Sato, Kohji; Schloss, Patrick; Watanabe, Yoshiyuki; Itoh, Yasushi; Tohyama, Masaya; Nishimura, Tsunehiko

1998-01-01

We investigated the effects of three cocaine analogs, beta-CIT (2-beta-carbomethoxy-3-beta-(4-iodophenyl)-tropane), beta-CIT-FE (2-beta-carbomethoxy-3-beta-(4-iodophenyl)-N-(2-fluoroethyl)-nortropane), and beta-CIT-FP (2-beta-carbomethoxy-3-beta-(4-iodophenyl)-N-(3-fluoropropyl)-nortropane), on the uptake of [ 3 H]dopamine(DA), serotonin(5-HT), and 1-norepinephrine (NE) using cell lines permanently expressing DA, 5-HT, and NE transporters, respectively, to determine their affinities for these three transporters. We generated cell lines stably expressing DA, 5-HT, and NE transporters, respectively, by the Chen-Okayama method, and then tested the abilities of (-)cocaine, beta-CIT, beta-CIT-FE, beta-CIT-FP, and clomipramine to inhibit the uptake of [ 3 H]DA, 5-HT, and 1-NE. Ki values of beta-CIT, beta-CIT-FE, and beta-CIT-FP for [ 3 H]DA, 5-HT, 1-NE uptake were 6, 29, and 33 nM, 91, 133, and 130 nM, and 28, 113 and 70 nM, respectively, whereas those of cocaine and clomipramine were 316, 581, and 176 nM and > 10,000, 437, and 851 nM, respectively. Beta-CIT, beta-CIT-FE, and beta-CIT-FP were shown to be potent DA, 5-HT, and NE uptake inhibitors. Beta-CIT and beta-CIT-FP were highly potent and selective dopamine uptake inhibitors, and therefore might be useful for imaging of DA transporter with single photon emission computed tomography (SPECT) or positron emission tomography (PET)

Beta-decay and decay heat. Summary report of consultants' meeting

International Nuclear Information System (INIS)

Nicols, A.L.

2006-01-01

Experts on decay data and decay heat calculations participated in a Consultants' Meeting organized at IAEA Headquarters on 12-14 December 2005. Debate focused on the validation of decay heat calculations as a function of cooling time for fuel irradiated in power reactors through comparisons with experimental benchmark data. Both the current understanding and quantification of mean beta and gamma decay energies were reviewed with respect to measurements and the Gross Theory of Beta Decay. Particular emphasis was placed on the known development of total absorption gamma-ray spectroscopy (TAGS), and detailed discussions took place to formulate the measurement requirements for mean beta and gamma data of individual radionuclides. This meeting was organized in cooperation with the OECD/NEA Working Party for Evaluation and Cooperation (WPEC). Proposals and recommendations were made to resolve particular difficulties, and an initial list of fission products was produced for TAGS studies. The discussions, conclusions and recommendations of the meeting are briefly described in this report. (author)

Delta-ray spectroscopy of quasi-atoms

International Nuclear Information System (INIS)

Kozhuharov, C.

1983-01-01

The spectroscopy of high energy delta-rays, emitted in collisions of very heavy ions, is studied. The ''orange''-type beta-spectrometer and the achromatic electron channel are the experimental setups. Delta ray production probabilities are studied as a function of the distance of closest approach R /SUB min/ or the impact parameter b. Coulomb ionization, ion trajectory, scaling laws, double differential cross sections, and K-X-rays information is extracted from the experiment. The dependence of delta-ray emission on the united charge number Z /SUB u/ is discussed. Asymmetric collision systems with Z x alpha approx. = 1 (delta ray spectrum from Pb→Sn collisions) are studied. Finally, very heavy collisions, such as 208 Pb + 208 Pb collisions at bombarding energy fas below the Coulomb barrier are touched upon

Far-ultraviolet and optical spectrophotometry of X-ray selected Seyfert galaxies

International Nuclear Information System (INIS)

Clarke, J.T.; Bowyer, S.; Grewing, M.; California Univ., Berkeley; Tuebingen Universitaet, West Germany)

1986-01-01

Five X-ray selected Seyfert galaxies were examined via near-simultaneous far-ultraviolet and optical spectrophotometry in an effort to test models for excitation of emission lines by X-ray and ultraviolet continuum photoionization. The observed Ly-alpha/H-beta ratio in the present sample averages 22, with an increase found toward the high-velocity wings of the H lines in the spectrum of at least one of the Seyfert I nuclei. It is suggested that Seyfert galaxies with the most high-velocity gas exhibit the highest Ly-alpha/H-beta ratios at all velocities in the line profiles, and that sometimes this ratio may be highest for the highest velocity material in the broad-line clouds. Since broad-lined objects are least affected by Ly-alpha trapping effects, they have Ly-alpha/H-beta ratios much closer to those predicted by early photoionization calculations. 21 references

Radiation synthesis of gelatin/CM-chitosan/{beta}-tricalcium phosphate composite scaffold for bone tissue engineering

Energy Technology Data Exchange (ETDEWEB)

Zhou Ying [College of Engineering, Peking University, Beijing 100871 (China); Center for Biomedical Materials and Tissue Engineering, Academy for Advanced Interdisciplinary Studies, Peking University, Beijing 100871 (China); Xu Ling, E-mail: lingxu@pku.edu.cn [College of Engineering, Peking University, Beijing 100871 (China); Center for Biomedical Materials and Tissue Engineering, Academy for Advanced Interdisciplinary Studies, Peking University, Beijing 100871 (China); Zhang Xiangmei; Zhao Yinghui [Center for Biomedical Materials and Tissue Engineering, Academy for Advanced Interdisciplinary Studies, Peking University, Beijing 100871 (China); Wei Shicheng, E-mail: sc-wei@pku.edu.cn [Center for Biomedical Materials and Tissue Engineering, Academy for Advanced Interdisciplinary Studies, Peking University, Beijing 100871 (China); Department of Oral and Maxillofacial Surgery, School and Hospital of Stomatology, Peking University, Beijing 100081 (China); Zhai Maolin [Beijing National Laboratory for Molecular Sciences, Department of Applied Chemistry, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871 (China)

2012-05-01

A series of biodegradable composite scaffolds was fabricated from an aqueous solution of gelatin, carboxymethyl chitosan (CM-chitosan) and {beta}-tricalcium phosphate ({beta}-TCP) by radiation-induced crosslinking at ambient temperature. Ultrasonic treatment on the polymer solutions significantly influenced the distribution of {beta}-TCP particles. An ultrasonic time of 20 min, followed by 30 kGy irradiation induced a crosslinked scaffold with homogeneous distribution of {beta}-TCP particles, interconnected porous structure, sound swelling capacity and mechanical strength. Fourier Transform Infrared Spectroscopy and X-ray Diffraction analysis indicated that {beta}-TCP successfully incorporated with the network of gelatin and CM-chitosan. In vivo implantation of the scaffold into the mandible of beagle dog revealed that the scaffolds had excellent biocompatibility and the presence of {beta}-TCP can accelerate bone regeneration. The comprehensive results of this study paved way for the application of gelatin/CM-chitosan/{beta}-TCP composite scaffolds as candidate of bone tissue engineering material. - Highlights: Black-Right-Pointing-Pointer Radiation induced a crosslinked scaffold with interconnected porous structure. Black-Right-Pointing-Pointer Ultrasonic time of 20 min led to homogenerously distribution of {beta}-TCP. Black-Right-Pointing-Pointer Increasing amount of {beta}-TCP would restrict the swelling properties. Black-Right-Pointing-Pointer Proper fraction of {beta}-TCP will promote the mechanical properties of the scaffolds. Black-Right-Pointing-Pointer Hybrid of {beta}-TCP promoted the bone regeneration of the mandibles of beagle dogs.

Biosynthesis and release of beta-endorphin-, N-acetyl beta-endorphin-, beta-endorphin-(1-27)-, and N-acetyl beta-endorphin-(1-27)-like peptides by rat pituitary neurointermediate lobe: beta-endorphin is not further processed by anterior lobe

International Nuclear Information System (INIS)

Liotta, A.S.; Yamaguchi, H.; Krieger, D.T.

1981-01-01

Continuous labeling and pulse-chase techniques were employed to study the synthesis and secretion of multiple forms of immunoreactive beta-endorphin by cultured dispersed rat anterior lobe cells and intact neurointermediate pituitary lobe. Intact neurointermediate lobes incorporated radiolabeled amino acids into four to six forms of immunoreactive beta-endorphin. Four of these forms were physicochemically similar to authentic beta-endorphin, N-acetylated beta-endorphin, beta-endorphin-(1-27), and N-acetylated beta-endorphin-(1-27). Pulse-chase studies indicated that a beta-lipotropin-like molecule served as a metabolic intermediate for a beta-endorphin-like molecule. As beta-endorphin-like material accumulated in the cell, some of it was N-acetylated (approximately 18% at 2 hr chase and approximately 65% at 18 hr chase). At later chase times, beta-endorphin-(1-27)- and N-acetylated beta-endorphin-(1-27)-like peptides were the predominant molecular species detected. All endorphin forms were detected in unlabeled tissue maintained in culture or tissue continuously labeled for 72 hr and were released into the medium under basal, stimulatory (10(-8) M norepinephrine), or inhibitory (10(-7) M dopamine) incubation conditions. In all cases, beta-endorphin-(1-27)-like species were the predominant forms (more than 70% of total) present in the cells and released into the medium. In contrast, approximately 90% of radiolabeled immunoreactive beta-endorphin extracted from anterior lobe cells and medium similarly incubated appeared to represent the authentic beta-endorphin molecule. Continuous labeling (72 hr) revealed the beta-lipotropin/beta-endorphin molar ratio to be approximately 4. We conclude that, in anterior lobe, most of the beta-endorphin is not processed further and is released intact, while in neurointermediate lobe, it serves as a biosynthetic intermediate

Molecular printboards: monolayers of beta-cyclodextrins on silicon oxide surfaces.

Science.gov (United States)

Onclin, Steffen; Mulder, Alart; Huskens, Jurriaan; Ravoo, Bart Jan; Reinhoudt, David N

2004-06-22

Monolayers of beta-cyclodextrin host molecules have been prepared on SiO2 surfaces. An ordered and stable cyano-terminated monolayer was modified in three consecutive surface reactions. First, the cyanide groups were reduced to their corresponding free amines using Red Al as a reducing agent. Second, 1,4-phenylene diisothiocyanate was used to react with the amine monolayer where it acts as a linking molecule, exposing isothiocyanates that can be derivatized further. Finally, per-6-amino beta-cyclodextrin was reacted with these isothiocyanate functions to yield a monolayer exposing beta-cyclodextrin. All monolayers were characterized by contact angle measurements, ellipsometric thickness measurements, Brewster angle Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, and time-of-flight secondary ion mass spectrometry, which indicate the formation of a densely packed cyclodextrin surface. It was demonstrated that the beta-cyclodextrin monolayer could bind suitable guest molecules in a reversible manner. A fluorescent molecule (1), equipped with two adamantyl groups for complexation, was adsorbed onto the host monolayer from solution to form a monolayer of guest molecules. Subsequently, the guest molecules were desorbed from the surface by competition with increasing beta-cyclodextrin concentration in solution. The data were fitted using a model. An intrinsic binding constant of 3.3 +/- 1 x 10(5) M(-1) was obtained, which corresponds well to previously obtained results with a divalent guest molecule on beta-cyclodextrin monolayers on gold. In addition, the number of guest molecules bound to the host surface was determined, and a surface coverage of ca. 30% was found.

Thermoluminescent dosimetry of new phosphors of Zn O exposed to beta radiation; Dosimetria termoluminiscente de nuevos fosforos de ZnO expuestos a radiacion beta

Energy Technology Data Exchange (ETDEWEB)

Cruz V, C.; Burruel I, S.E.; Grijalva M, H. [UNISON, A.P. 130, Hermosillo, Sonora (Mexico); Barboza F, M.; Bernal, R. [CIF, UNISON, A.P. 5-088, Hermosillo, Sonora (Mexico)

2004-07-01

In this work, we report the thermoluminescence dosimetry of a new Zn O phosphor obtained by annealing of Zn S powder precipitated when Zn S films were grown by employing a CBD method. The collected Zn S powder was pressed in a die to form pellets which were subjected to different thermal treatments under air atmosphere. X-ray diffraction (XRD) patterns and energy-dispersive X-ray Spectrometry (EDS) analyses confirmed the transformation of Zn S to Zn O. The phosphors thus obtained were exposed to high doses of beta radiation and their thermoluminescent dosimetry show that these new phosphors are materials suitable to be used in high dose thermoluminescence dosimetry. (Author)

Modification of polyethylene films by radiation grafting of glycidyl methacrylate and immobilization of {beta}-cyclodextrin

Energy Technology Data Exchange (ETDEWEB)

Nava-Ortiz, C.A.B. [Departamento de Quimica de Radiaciones y Radioquimica, Instituto de Ciencias Nucleares, Universidad Nacional Autonoma de Mexico, Circuito Exterior, Ciudad Universitaria, Mexico DF 04510 (Mexico); Burillo, G. [Departamento de Quimica de Radiaciones y Radioquimica, Instituto de Ciencias Nucleares, Universidad Nacional Autonoma de Mexico, Circuito Exterior, Ciudad Universitaria, Mexico DF 04510 (Mexico)], E-mail: burillo@nucleares.unam.mx; Bucio, E. [Departamento de Quimica de Radiaciones y Radioquimica, Instituto de Ciencias Nucleares, Universidad Nacional Autonoma de Mexico, Circuito Exterior, Ciudad Universitaria, Mexico DF 04510 (Mexico); Alvarez-Lorenzo, C. [Departamento de Farmacia y Tecnologia Farmaceutica, Facultad de Farmacia, Universidad de Santiago de Compostela, 15782 Santiago de Compostela (Spain)

2009-01-15

Glycidyl methacrylate was grafted onto polyethylene films using a preirradiation method with {gamma} rays. The effect of absorbed dose, monomer concentration, and reaction time on the degree of grafting was determined. The grafted samples were verified by FTIR-ATR spectroscopy. {beta}-Cyclodextrin was immobilized onto polypropylene modified with glycidyl methacrylate, and the ability of the cavities of {beta}-cyclodextrin to form inclusion complexes was demonstrated using the typically organic compound approach with m-toluic acid (3-MBA) as a probe.

Development of Simultaneous Beta-and-Coincidence-Gamma Imager for Plant Imaging Research

Energy Technology Data Exchange (ETDEWEB)

Tai, Yuan-Chuan [Washington Univ., St. Louis, MO (United States). School of Medicine

2016-09-30

The goal of this project is to develop a novel imaging system that can simultaneously acquire beta and coincidence gamma images of positron sources in thin objects such as leaves of plants. This hybrid imager can be used to measure carbon assimilation in plants quantitatively and in real-time after C-11 labeled carbon-dioxide is administered. A better understanding of carbon assimilation, particularly under the increasingly elevated atmospheric CO₂ level, is extremely critical for plant scientists who study food crop and biofuel production. Phase 1 of this project is focused on the technology development with 3 specific aims: (1) develop a hybrid detector that can detect beta and gamma rays simultaneously; (2) develop an imaging system that can differentiate these two types of radiation and acquire beta and coincidence gamma images in real-time; (3) develop techniques to quantify radiotracer distribution using beta and gamma images. Phase 2 of this project is to apply technologies developed in phase 1 to study plants using positron-emitting radionuclide such as ¹¹C to study carbon assimilation in biofuel plants.

Effects of 17 beta-estradiol on radiation transformation in vitro; inhibition of effects by protease inhibitors

International Nuclear Information System (INIS)

Kennedy, A.R.; Weichselbaum, R.R.

1981-01-01

We have investigated the effects of 17 beta-estradiol, given both alone and with X-irradiation, on the induction of malignant transformation in vitro. Treatment with 10(-6)M 17 beta-estradiol for 6 weeks, or 10(-5)M 17 beta-estradiol for only 5 days, induced malignant transformation in C3H 10T1/2 cells. Estradiol also acted as a cocarcinogen for X-ray induced transformation; the results indicate an additive effect when the cells were exposed to both agents together. The protease inhibitors antipain and leupeptin suppressed estradiol induced transformation as well as the additive effect observed for estradiol-radiation transformation

Effects of 17 beta-estradiol on radiation transformation in vitro; inhibition of effects by protease inhibitors

Energy Technology Data Exchange (ETDEWEB)

Kennedy, A.R.; Weichselbaum, R.R.

1981-01-01

We have investigated the effects of 17 beta-estradiol, given both alone and with X-irradiation, on the induction of malignant transformation in vitro. Treatment with 10(-6)M 17 beta-estradiol for 6 weeks, or 10(-5)M 17 beta-estradiol for only 5 days, induced malignant transformation in C3H 10T1/2 cells. Estradiol also acted as a cocarcinogen for X-ray induced transformation; the results indicate an additive effect when the cells were exposed to both agents together. The protease inhibitors antipain and leupeptin suppressed estradiol induced transformation as well as the additive effect observed for estradiol-radiation transformation.

Electrets for beta radiation detection

International Nuclear Information System (INIS)

Campos, L.L.; Caldas, L.V.E.; Mascarenhas, S.

1983-01-01

Electret dosimetry has been reviewed by Gross. A cylindrical electret ionization-chamber type dosimeter has been studied for X and gamma rays and neutrons. The principle of the dosimeter is electret charge compensation due to ionization in the chamber volume. Electret ionization chambers can be designed with one or more electrets and in various shapes. This study is concerned with a simple system, similar to a cylindrical ionization chamber (sensitive volume: 3,5 cm 3 ) using teflon electrets. Aluminum and lucite were used as wall-materials. Other experiences were performed using chambers without wall, i.e., without defined sensitive volume. The teflon electrets were obtained by Corona discharge in the gas surrounding them. The measurement of the electret charge was made by induction using a co-axial insulated metal chamber connected to an electrometer Keithley 610C. By measuring the charge before and after irradiation it is possible to obtain a calibration curve: charge (Q) versus absorbed dose (D) for the dosimeter. The irradiation setup used was the Beta Secondary Standard System of IPEN calibration laboratory with four beta sources: 90 Sr 90 Y (74 and 1850 MBq), 204 Tl (18,5 MBq) and 147 Pm (518 MBq). In some cases a 85 Kr source was also used. The electrets were tested in different radiation field geometries: electret axis parallel and perpendicular to the field. In conclusion, depending on the wall material and radiation field geometry, the teflon electret detector can be used for different dose interval determinations, using beta radiation

Ultralow background germanium gamma-ray spectrometer using superclean materials and cosmic-ray anticoincidence

International Nuclear Information System (INIS)

Reeves, J.H.; Hensley, W.K.; Brodzinski, R.L.; Ryge, P.

1983-10-01

Efforts to measure the double beta decay of 76 Ge as predicted by Grand Unified Theories have resulted in the development of a high resolution germanium diode gamma-ray spectrometer with an exceptionally low background. This paper describes the development of this system and how these techniques can be utilized to significantly reduce the background in high resolution photon spectrometers at only a moderate cost

Structure of poly (. beta. -alanine) polymerized in the solid state. Koso jugo shita. beta. -alanine no kozo

Energy Technology Data Exchange (ETDEWEB)

Sakabe, Hiroshi; Nakamura, Hiroyoshi; Kimura, Hirokazu; Konishi, Takashi [Kyoto Inst. of Tech., Kyoto (Japan). Faculty of Textile Science

1989-12-05

The structure of poly({beta}-alanine) polymerized in the solid state was studied. This polymerization was carried out on a single crystal of {beta}-alanine at 170 centigrade for 40 h in an evacuated tube. The crystal structure of the polymer was assigned to I-type crystal of Nylon 3. The polymer chains were oriented vertical to the crystal side and different to monomer crystal orientation. This may be caused by the molecular layer slipping along the cleavage plane of monomer crystal. A scanning electron microscope(SEM) showed the band structure of hundreds nm width of same orientation, but X ray showed only unoriented rings, so that they are estimated to be the structure of fine fibril like assembly or necklace like continuous chain structure of grains. Near the surface, whiskers which were thought to be oligomer of low degree of polymerization, were observed. The SEM of end view of the etched surface did not show the laminated structure but showed the network structure of about 1 mu-m which is thought to be fibril precursor. 12 refs., 10 figs.

Purification of beta-acetylglucosaminase and beta-galactosidase from ram testis.

Science.gov (United States)

Caygill, J C; Roston, C P; Jevons, F R

1966-02-01

1. The presence of beta-galactosidase (EC 3.2.1.23) in an acetic acid extract of ram testis is reported. Some properties of the crude enzyme preparation were studied. 2. The purification of beta-acetylglucosaminase (EC 3.2.1.30) and of beta-galactosidase from the ram-testis extract by ammonium sulphate precipitation and chromatography on a CM-cellulose column is described. 3. The final purifications of the separated enzymes achieved were for the beta-acetylglucosaminase 35 times and for the beta-galactosidase 99 times. 4. The possibility of using DEAE-cellulose and Sephadex G-200 to purify the enzymes was investigated.

Supported Zeolite Beta Layers via an Organic Template-Free Preparation Route

Directory of Open Access Journals (Sweden)

Stephanie Reuss

2018-01-01

Full Text Available Layers of high silica zeolites, synthesized with an organic structure directing agent (OSDA and grown onto porous support structures, frequently suffer from the thermal stress during the removal of OSDA via the calcination process. The different thermal expansion coefficients of the zeolite and the support material, especially when stainless steel is used as a support, causes enormous tension resulting in defect formation in the zeolite layer. However, the calcination is an easy procedure to decompose the OSDA in the pore system of the zeolite. Recently, methods to synthesize zeolite beta without the use of an organic structure directing agent have been described. In the present study, a seed-directed synthesis is used to prepare OSDA-free zeolite beta layers on stainless steel supports via an in situ preparation route. For the application as membrane, a porous stainless steel support has been chosen. The beta/stainless steel composites are characterized by X-ray diffraction (XRD and scanning electron microscopy (SEM. To prove its possible application as a membrane, the beta/stainless steel composites were also tested by single gas permeances of H2, He, CO2, N2, and CH4.

Supported Zeolite Beta Layers via an Organic Template-Free Preparation Route.

Science.gov (United States)

Reuss, Stephanie; Sanwald, Dirk; Schülein, Marion; Schwieger, Wilhelm; Al-Thabaiti, Shaeel A; Mokhtar, Mohamed; Basahel, Sulaiman N

2018-01-21

Layers of high silica zeolites, synthesized with an organic structure directing agent (OSDA) and grown onto porous support structures, frequently suffer from the thermal stress during the removal of OSDA via the calcination process. The different thermal expansion coefficients of the zeolite and the support material, especially when stainless steel is used as a support, causes enormous tension resulting in defect formation in the zeolite layer. However, the calcination is an easy procedure to decompose the OSDA in the pore system of the zeolite. Recently, methods to synthesize zeolite beta without the use of an organic structure directing agent have been described. In the present study, a seed-directed synthesis is used to prepare OSDA-free zeolite beta layers on stainless steel supports via an in situ preparation route. For the application as membrane, a porous stainless steel support has been chosen. The beta/stainless steel composites are characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). To prove its possible application as a membrane, the beta/stainless steel composites were also tested by single gas permeances of H₂, He, CO₂, N₂, and CH₄.

Bone regeneration of calvarial defect using marine calcareous-derived beta-tricalcium phosphate macrospheres

Directory of Open Access Journals (Sweden)

Joshua Chou

2014-02-01

Full Text Available The aim of this study was to examine the bone regeneration properties of beta-tricalcium phosphate hydrothermally converted from foraminifera carbonate exoskeleton in the repair of rat calvarial defect. These natural materials possess unique interconnected porous network with uniform pore size distribution, which can be potentially advantageous. In total, 20 adult male Wistar rats received full-thickness calvarial defect with a diameter of 5 mm. The rate of newly formed bone was measured radiologically by X-ray and micro-computed tomography and by histologic examination. After 2 weeks, the beta-tricalcium phosphate group exhibited full closure of the defect site, while control group remained unrestored at the end of the 6-week experimentation. It was observed that the newly regenerated bone thickened over the course of the experiment in the beta-tricalcium phosphate group. No soft tissue reaction was observed around the beta-tricalcium phosphate implant and the rats remained healthy. These results showed that repair of the calvarial defect can be achieved by biomimetic beta-tricalcium phosphate macrospheres, which hold potential for application as bone grafts for bone augmentation surgeries.

The need for international standardization in clinical beta dosimetry for brachytherapy

International Nuclear Information System (INIS)

Quast, U.; Boehm, J.; Kaulich, T.W.

2002-01-01

Beta radiation has found increasing interest in radiotherapy. Besides the curative treatment of small and medium-sized intraocular tumors by means of ophthalmic beta radiation plaques, intravascular brachytherapy has proven to successfully overcome the severe problem of restenosis after interventional treatment of arterial stenosis in coronaries and peripheral vessels in many clinical trials with a large number of patients. Prior to initiating procedures applying beta radiation in radiotherapy, however, there is a common need to specify methods for the determination and specification of the absorbed dose to water or tissue and their spatial distributions. The IAEA-TECDOC-1274 Calibration of photon and beta ray sources used in brachytherapy (2002) is a help for photon brachytherapy calibration. But, for beta seed and line sources, IAEA recommends well type ionization chambers as working standards which are far from measuring absorbed dose to water of the radiation clinically used. Although the application of such working standards seems to be more precise, large errors can occur when the medical physicist has to convert the calibration data to absorbed dose to water of the beta radiation emitted. The user must believe that the source is equally activated and that the manufacturer did not change the design and construction of the source encapsulation. With the DGMP Report 16 (2001) Guidelines for medical physical aspects of intravascular brachytherapy a very detailed code of practice is given, especially for the calibration and clinical dosimetry of intravascular beta radiation sources. As there is a global need for standardization in clinical dosimetry for intravascular brachytherapy utilizing beta radiation, the DIN-NAR, the German committee on standardization in radiology, task group dosimetry, has initiated an international adhoc working group for a new ISO work item proposal on the standardization of procedures in clinical dosimetry to guarantee reliable

Preparation of hydroxyapatite nanoparticles facilitated by the presence of {beta}-cyclodextrin

Energy Technology Data Exchange (ETDEWEB)

Martinez-Perez, Carlos A., E-mail: camartin@uacj.mx [Institute of Engineering and Technology, Autonomous University of Juarez, UACJ, Ave. del Charro 610 norte, C.P. 32320, Cd. Juarez, Chihuahua (Mexico); Garcia-Montelongo, Jorge; Garcia Casillas, Perla E.; Farias-Mancilla, Jose R. [Institute of Engineering and Technology, Autonomous University of Juarez, UACJ, Ave. del Charro 610 norte, C.P. 32320, Cd. Juarez, Chihuahua (Mexico); Monreal Romero, Humberto [School of Odontology, Autonomous University of Chihuahua, UACH, Ave. Universidad s/n Campus Universitario I, C.P. 31170, Chihuahua (Mexico)

2012-09-25

Highlights: Black-Right-Pointing-Pointer It was found that {beta}-cyclodextrin can control the particle size in the production of nanohydroxyapatite. Black-Right-Pointing-Pointer Particle size in the range of 30-50 nm was obtained. Black-Right-Pointing-Pointer A new simple methodology for the preparation of hydroxyapatite nanoparticles with a well controlled size and narrow particles size distribution was developed. - Abstract: Hydroxyapatite nanoparticles with uniform morphology have been successfully synthesized by a chemical coprecipitation method and facilitated by the presence of the {beta}-cyclodextrin. X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM); and Fourier Transformed Infrared Spectroscopy (FT-IR) were used in order to characterize the hydroxyapatite samples. The experimental results indicate that the obtained HA is in the range of 20-50 nm. Also it was found that the content of {beta}-CD has an impact on the purity of the HA as well in the particle size of the hydroxyapatite nanoparticles.

Structure of $^{191}$Pb from $\\alpha$- and $\\beta$-decay spectroscopy

CERN Document Server

Cocolios, T E; Van de Walle, J; Franchoo, S; Marsh, B A; Sjoedin, A M; Huyse, M; Zemlyanoy, S; Cocolios, T E; Bastin, B; Barzakh, A; Page, R D; Mane, E; Van Duppen, P; Darby, I G; Venhart, M; Kudryavtsev, Yu; Huber, G; Fedosseev, V N; Andreyev, A N; Keupers, M; Flanagan, K T; Stefan, I; Dexters, W; Koester, U; Antalic, S; Buscher, J; Molkanov, P; Fedorov, D V

2010-01-01

Complementary studies of $^{191}$Pb have been made in the $\\beta$- decay of $^{191}$Bi at LISOL (CRC) and in the $\\alpha$- decay of $^{195}$Po at ISOLDE (CERN). Fine structures in the $\\alpha$- decay of the low-spin and high-spin isomers of $^{195}$Po have been fully resolved. Identification of the parent state is made possible via isomer selection based on narrow-band laser frequency scanning. The $\\alpha$-particle and $\\gamma$-ray energies have been determined with greater precision. New $\\alpha$-particle and $\\gamma$-ray energies are identified. Branching ratios in the decay of $^{195}$Po and $^{191}$Pb have been examined.

Theoretical study and construction of a multichannel {beta} spectrometer with uniform magnetic field; Etude et realisation d'un spectrometre {beta} multivoies a champ magnetique uniforme

Energy Technology Data Exchange (ETDEWEB)

Schussler, F [Commissariat a l' Energie Atomique, Grenoble (France). Centre d' Etudes Nucleaires

1965-09-01

After a brief survey of the interest of a multichannel beta spectrometer for studying decay schemes of short lived nuclides (30 seconds minimum, the theoretically well known characteristics of uniform magnetic field analyser (image of a large source, transmission and resolution) are briefly remembered. In the second part, the apparatus built as a result of these calculations is described. This apparatus allows the determination of beta spectra by simultaneous determination of the beta spectra in coincidence with four gamma rays predetermined in the gamma spectrum of the studied nuclide. Finally, in the last part, the experimental characteristics of the spectrometer (calibration in energy and transmission) and the first measurement of beta spectra ({sup 155}Sm) and of coincidences ({sup 24}Na), are given. (author) [French] Apres avoir brievement souligne l'interet pratique que presente un spectrometre multivoies pour l'etude des schemas de desintegration des corps radioactifs de courtes periodes (30 secondes au maximum), l'auteur effectue un rappel des caracteristiques theoriques bien connues d'un analyseur magnetique a champ uniforme (image d'une source etendue) calcul de la transmission et du pouvoir de resolution. Une deuxieme partie est consacree a la description de l'appareil realise d'apres ces calculs. Cet appareil permet le releve des spectres beta par detection, simultanee de dix groupes d'electrons d'energies differentes; il permet egalement le releve simultane des spectres beta en coincidence avec quatre rayonnements gammas preselectionnes a l'avance dans le spectre gamma du corps etudie. Dans une derniere partie enfin, sont donnees les caracteristiques experimentales du spectrometre (etalonnage en energie et en transmission) ainsi que les premiers resultats des etudes de spectre beta ({sup 155}Sm) et de coincidence ({sup 24}Na). (auteur)

Betting Against Beta

DEFF Research Database (Denmark)

Frazzini, Andrea; Heje Pedersen, Lasse

We present a model with leverage and margin constraints that vary across investors and time. We find evidence consistent with each of the model’s five central predictions: (1) Since constrained investors bid up high-beta assets, high beta is associated with low alpha, as we find empirically for U...... of the BAB factor is low; (4) Increased funding liquidity risk compresses betas toward one; (5) More constrained investors hold riskier assets........S. equities, 20 international equity markets, Treasury bonds, corporate bonds, and futures; (2) A betting-against-beta (BAB) factor, which is long leveraged low beta assets and short high-beta assets, produces significant positive risk-adjusted returns; (3) When funding constraints tighten, the return...

Conversion of beta-methylbutyric acid to beta-hydroxy-beta-methylbutyric acid by Galactomyces reessii.

OpenAIRE

Lee, I Y; Nissen, S L; Rosazza, J P

1997-01-01

beta-Hydroxy-beta-methylbutyric acid (HMB) has been shown to increase strength and lean mass gains in humans undergoing resistance-exercise training. HMB is currently marketed as a calcium salt of HMB, and thus, environmentally sound and inexpensive methods of manufacture are being sought. This study investigates the microbial conversion of beta-methylbutyric acid (MBA) to HMB by cultures of Galactomyces reessii. Optimal concentrations of MBA were in the range of 5 to 20 g/liter for HMB produ...

Effect of water on self-assembled tubules in {beta}-sitosterol + {gamma}-oryzanol-based organogels

Energy Technology Data Exchange (ETDEWEB)

Adel, Ruud den; Heussen, Patricia C M; Bot, Arjen, E-mail: ruud-den.adel@unilever.co [Unilever Research and Development Vlaardingen, Olivier van Noortlaan 120, NL-3133 AT Vlaardingen (Netherlands)

2010-10-01

Mixtures of {beta}-sitosterol and {gamma}-oryzanol form a network in triglyceride oil that may serve as an alternative to the network of small crystallites of triglycerides occurring in regular oil structuring. The present x-ray diffraction study investigates the relation between the crystal forms of the individual compounds and the mixture in oil, water and emulsion. {beta}-Sitosterol and {gamma}-oryzanol form normal crystals in oil, in water, or in emulsions. The crystals are sensitive to the presence of water. The mixture of {beta}-sitosterol + {gamma}-oryzanol forms crystals in water and emulsions that can be traced back to the crystals of the pure compounds. Only in oil, a completely different structure emerges in the mixture of {beta}-sitosterol + {gamma}-oryzanol, which bears no relation to the structures that are formed by both individual compounds, and which can be identified as a self-assembled tubule (diameter 7.2{+-}0.1 nm, wall thickness 0.8{+-}0.2 nm).

Forward-Looking Betas

DEFF Research Database (Denmark)

Christoffersen, Peter; Jacobs, Kris; Vainberg, Gregory

Few issues are more important for finance practice than the computation of market betas. Existing approaches compute market betas using historical data. While these approaches differ in terms of statistical sophistication and the modeling of the time-variation in the betas, they are all backward......-looking. This paper introduces a radically different approach to estimating market betas. Using the tools in Bakshi and Madan (2000) and Bakshi, Kapadia and Madan (2003) we employ the information embedded in the prices of individual stock options and index options to compute our forward-looking market beta...

Determination of 131mXe and 133mXe in the presence of 133gXe via combined beta-spectroscopy and delayed coincidence

International Nuclear Information System (INIS)

Reeder, P.L.; Bowyer, T.W.; McIntyre, J.I.; Pitts, W.K.

2001-01-01

The International Monitoring System for the Comprehensive Nuclear-Test-Ban Treaty will include measurements of Xe fission products. Pacific Northwest National Laboratory has developed an automated system for separating Xe from air which detects Xe fission products using a beta-gamma counting system for 131m Xe, 133m Xe, 133g Xe, and 135g Xe. Betas and conversion electrons are detected in a plastic scintillation cell containing the Xe sample. Gamma and X-rays are detected in a NaI(Tl) scintillation detector which surrounds the plastic scintillator sample cell. Two-dimensional pulse-height spectra of gamma-energy versus beta-energy are obtained. The plastic scintillator spectrum in coincidence with the 31-keV X-rays from 131m Xe. 133m Xe, and 133g Xe is a complex mixture of conversion electrons and betas. A new technique to simultaneously measure the delayed coincidence (T 1/2 = 6.27 ns) between beta-particles from 133g Xe and conversion electrons depopulating the 81-keV state in 133 Cs is being developed. This technique allows separation of the 133g Xe beta spectrum from the conversion electrons due to 131m Xe and 133m Xe and uniquely quantifies all three nuclides. (author)

Analyzing the evolution of beta-endorphin post-translational processing events: studies on reptiles.

Science.gov (United States)

Shoureshi, Pezhman; Baron, Andrea; Szynskie, Laura; Dores, Robert M

2007-01-01

In many cartilaginous fishes, most ray-finned fishes, lungfishes, and amphibians, the post-translational processing of POMC includes the monobasic cleavage of beta-endorphin to yield an opioid that is eight to ten amino acids in length. The amino acid motif within the beta-endorphin sequence required for a monobasic cleavage event is -E-R-(S/G)-Q-. Mammals and birds lack this motif and as a result beta-endorphin(1-8) is a not an end-product in either group. Since both mammals and birds were derived from ancestors with reptilian origins, an analysis of beta-endorphin sequences from extant groups of reptiles should provide insights into the manner in which beta-endorphin post-translational processing mechanisms have evolved in amniotes. To this end a POMC cDNA was cloned from the pituitary of the turtle, Chrysemys scripta. The beta-endorphin sequence in this species was compared to other reptile beta-endorphin sequences (i.e., Chinese soft shell turtle and gecko) and to known bird and mammal sequences. This analysis indicated that either the loss of the arginine residue at the cleavage site (the two turtle species, chick, and human) or a substitution at the glutamine position in the consensus sequence (gecko and ostrich) would account for the loss of the monobasic cleavage reaction in that species. Since amphibians are capable of performing the beta-endorphin monobasic reaction, it would appear that the amino acid substitutions that eliminated this post-translational process event in reptilian-related tetrapods must have occurred in the ancestral amniotes.

Method of fission product beta spectra measurements for predicting reactor anti-neutrino emission

Energy Technology Data Exchange (ETDEWEB)

Asner, D.M.; Burns, K.; Campbell, L.W.; Greenfield, B.; Kos, M.S., E-mail: markskos@gmail.com; Orrell, J.L.; Schram, M.; VanDevender, B.; Wood, L.S.; Wootan, D.W.

2015-03-11

The nuclear fission process that occurs in the core of nuclear reactors results in unstable, neutron-rich fission products that subsequently beta decay and emit electron antineutrinos. These reactor neutrinos have served neutrino physics research from the initial discovery of the neutrino to today's precision measurements of neutrino mixing angles. The prediction of the absolute flux and energy spectrum of the emitted reactor neutrinos hinges upon a series of seminal papers based on measurements performed in the 1970s and 1980s. The steadily improving reactor neutrino measurement techniques and recent reconsiderations of the agreement between the predicted and observed reactor neutrino flux motivates revisiting the underlying beta spectra measurements. A method is proposed to use an accelerator proton beam delivered to an engineered target to yield a neutron field tailored to reproduce the neutron energy spectrum present in the core of an operating nuclear reactor. Foils of the primary reactor fissionable isotopes placed in this tailored neutron flux will ultimately emit beta particles from the resultant fission products. Measurement of these beta particles in a time projection chamber with a perpendicular magnetic field provides a distinctive set of systematic considerations for comparison to the original seminal beta spectra measurements. Ancillary measurements such as gamma-ray emission and post-irradiation radiochemical analysis will further constrain the absolute normalization of beta emissions per fission. The requirements for unfolding the beta spectra measured with this method into a predicted reactor neutrino spectrum are explored.

Precision Study of the $\\beta$-decay of $^{62}$Ga

CERN Multimedia

2002-01-01

It is proposed to perform a precision study of the $\\beta$-decay of $\\,^{62}$Ga taking advantage of recent developments of the ISOLDE Laser Ion Source. The goal is to eventually extend the high-precision knowledge of superallowed $\\beta$-decays beyond the nine decays that presently are used for extracting the V$_{ud}$ quark mixing matrix element of the CKM matrix. The scientific motivations are the current deviation of more than 2$\\sigma$ of the unitary condition of this matrix, which could be an indication of non-standard-model physics, and a test of the theoretical corrections applied to the experimental data. The experiment will utilise the Total Absorption $\\gamma$-ray (TAG) spectrometer in order to determine weak branchings to excited states in $^{62}$Zn and the ISOLDE spectroscopy station to perform half-life measurements and detailed spectroscopy of this nucleus.

Enantioselective synthesis of alpha,beta-disubstituted-beta-amino acids.

Science.gov (United States)

Sibi, Mukund P; Prabagaran, Narayanasamy; Ghorpade, Sandeep G; Jasperse, Craig P

2003-10-01

Highly diastereoselective and enantioselective addition of N-benzylhydroxylamine to imides 17 and 20-30 produces alpha,beta-trans-disubstituted N-benzylisoxazolidinones 19 and 31-41. These reactions proceed in 60-96% ee with 93-99% de's using 5 mol % of Mg(NTf2)2 and ligand 18. The product isoxazolidinones can be hydrogenolyzed directly to provide alpha,beta-disubstituted-beta-amino acids.

A simple method for determining the activity of large-area beta sources constructed from anodized aluminum foils

International Nuclear Information System (INIS)

Stanga, D.

2014-01-01

A simple method has been developed for determining the activity of large-area beta reference sources in anodized aluminum foils. It is based on the modeling of the transmission of beta rays through thin foils in planar geometry using Monte Carlo simulation. The method was checked experimentally and measurement results show that the activity of large-area beta reference sources in anodized aluminum foils can be measured with standard uncertainties smaller than the limit of 10% required by ISO 8769. - Highlights: • A method for determining the activity of large-area beta sources is presented. • The method is based on a model of electron transport in planar geometry. • The method makes use of linear programming for determining the activity. • The uncertainty of the method is smaller than 10%

Beta-ray depth dose in tissue equivalent material due to gaseous radioactive effluents from nuclear power plants

International Nuclear Information System (INIS)

Schadt, W.W.

1978-01-01

The magnitude of the absorbed dose to skin from beta particles emitted by the radionuclides in gaseous effluents from boiling water nuclear power reactors is investigated in this dissertation. Using the radionuclide release patterns of F. Brutschy and the beta dosimetry methods of M. Berger, an equation is derived which gives the dose rate in rads per day when the total radionuclide concentration is one microcurie per gram of air. The coefficients in the equation are presented for a wide range of reactor gas hold-up times (48 minutes to 6 days) and plume environmental transit time (0.5 to 60 minutes). The beta dose rates at the skin surface are found to range from 3.9 to 26.7 rads per day. An upper limit of the relative standard deviation in the dose rate is estimated to be 30 percent. The techniques used to develop the equation are applied to data from the Millstone Nuclear Power Station obtained during the summer of 1972. The beta dose at a site 1.7 miles from the reactor is determined to have been 675 millirads per year at the skin surface and 476 millirads per year at a depth of 200 micrometers. At a site 5.1 miles from the reactor these dose rates were 138 and 100 millirads per year respectively

Structural and optical properties of {beta}-FeSi{sub 2}/Si(100) prepared by laser ablation method

Energy Technology Data Exchange (ETDEWEB)

Kakemoto, H; Makita, Y; Obara, A; Tsai, Y; Sakuragi, S; Ando, S; Tsukamoto, T

1997-07-01

{beta}-FeSi{sub 2} is a promising material for the application of various electronic, optoelectronic and energy devices. The authors present here the semiconducting properties of {beta}-FeSi{sub 2} films on Si(100) substrate prepared by laser ablation method. Samples were grown using poly-crystalline bulk {beta}-FeSi{sub 2} prepared by horizontal gradient freeze method. For the monitoring of growth, in-situ observation of ablation plume was made through fluorescence spectroscopy. Reflection of high-energy electron beam diffraction (RHEED) was also made in-situ to see the surface morphology. Characterization of the films by X-ray diffraction presented purely {beta}(220) orientation. Raman scattering measurements at room temperature also indicated that the grown films are semiconducting {beta}-FeSi{sub 2}. Optical absorption spectra at room temperature showed absorption coefficient higher than 10{sup 5} cm{sup {minus}1} above the band-gap ({approximately}1.2 eV). It was revealed that high quality semiconducting {beta}-FeSi{sub 2} films can be fabricated by laser ablation method without post-annealing.

Time and dose-related changes in the thickness of pig skin after irradiation with single doses of [sup 90]Sr/[sup 90]Y [beta]-rays

Energy Technology Data Exchange (ETDEWEB)

Rezvani, M.; Hamlet, R.; Hopewell, J.W.; Sieber, V.K. (Churchill Hospital, Oxford (United Kingdom))

1994-04-01

Time-related changes in pig skin thickness have been evaluated using a non-invasive ultrasound technique after exposure to a range of single doses of [sup 90]Sr/[sup 90]Yr [beta]-rays. The reduction in relative skin thickness developed in two distinct phases: the first was between 12 and 20 weeks postirradiation. No further changes were then seen until 52 weeks postirradiation when a second phase of skin thinning was observed. This was complete after 76 weeks and no further changes in relative skin thickness were seen in the maximum follow up period of 129 weeks. The timings of these phases of damage were independent of the radiation dose, however, the severity of both phases of radiation-induced skin thinning were dose related. (Author).

BetaTPred: prediction of beta-TURNS in a protein using statistical algorithms.

Science.gov (United States)

Kaur, Harpreet; Raghava, G P S

2002-03-01

beta-turns play an important role from a structural and functional point of view. beta-turns are the most common type of non-repetitive structures in proteins and comprise on average, 25% of the residues. In the past numerous methods have been developed to predict beta-turns in a protein. Most of these prediction methods are based on statistical approaches. In order to utilize the full potential of these methods, there is a need to develop a web server. This paper describes a web server called BetaTPred, developed for predicting beta-TURNS in a protein from its amino acid sequence. BetaTPred allows the user to predict turns in a protein using existing statistical algorithms. It also allows to predict different types of beta-TURNS e.g. type I, I', II, II', VI, VIII and non-specific. This server assists the users in predicting the consensus beta-TURNS in a protein. The server is accessible from http://imtech.res.in/raghava/betatpred/

X-ray diffraction study of the polymorphism of hydrated diacyl- and dialkylphosphatidylethanolamines.

Science.gov (United States)

Seddon, J M; Cevc, G; Kaye, R D; Marsh, D

1984-06-05

The structure and polymorphism of a homologous series of diacyl- and of dialkylphosphatidylethanolamines have been investigated by X-ray diffraction, calorimetry, and density measurement. The compositional dependence of the repeat spacings of the gel (L beta or L beta'), fluid bilayer (L alpha), and inverted hexagonal (HII) phases has been determined both for the short chain length (di-C12) dialkyl didodecylphosphatidylethanolamine (DDPE) and for the long chain length (di-C20) diacyl diarachinoylphosphatidylethanolamine (DAPE). These data, in conjunction with the measured phase transition temperatures obtained both by X-ray diffraction and by differential scanning calorimetry, have been used to construct phase diagrams for the two lipids. DDPE exhibits metastable behavior in the L beta and L alpha phases below 44 degrees C at all water contents and forms cubic and other nonlamellar phases between the L alpha and HII phases. At low water contents, crystalline and fluid phases coexist at temperatures up to 83 degrees C. For DAPE, the behavior is simpler. In the gel phase, the hydrocarbon chains are tilted at 29 degrees to the bilayer normal, and metastability is only observed at water contents below 3 wt %. The L alpha phase is adopted within a narrow temperature range and then transforms directly to the HII phase. The structural parameters of the L beta (L beta'), L alpha, and HII phases of DDPE and DAPE have been calculated from the X-ray data, in conjunction with the measured values of lipid partial specific volume. In addition, the chain-length dependence of the repeat spacings of the phases has been measured for the homologous series of diacyl and dialkyl lipids. Taken together, the results allow a detailed description of the effects of temperature, hydration, and chain length on the polymorphism of the saturated phosphatidylethanolamines.

X-ray scattering from surfaces of organic crystals

DEFF Research Database (Denmark)

Gidalevitz, D.; Feidenhans'l, R.; Smilgies, D.-M.

1997-01-01

X-ray scattering experiments have been performed on the surfaces of organic crystals. The (010) cleavage planes of beta-alanine and alpha-glycine were investigated, and both specular and off-specular crystal truncation rods were measured. This allowed a determination of the molecular layering...

Roughing up Beta

DEFF Research Database (Denmark)

Bollerslev, Tim; Li, Sophia Zhengzi; Todorov, Viktor

-section. An investment strategy that goes long stocks with high jump betas and short stocks with low jump betas produces significant average excess returns. These higher risk premiums for the discontinuous and overnight market betas remain significant after controlling for a long list of other firm characteristics......Motivated by the implications from a stylized equilibrium pricing framework, we investigate empirically how individual equity prices respond to continuous, or \\smooth," and jumpy, or \\rough," market price moves, and how these different market price risks, or betas, are priced in the cross......-section of expected returns. Based on a novel highfrequency dataset of almost one-thousand individual stocks over two decades, we find that the two rough betas associated with intraday discontinuous and overnight returns entail significant risk premiums, while the intraday continuous beta is not priced in the cross...

Analysis of alloys and salt solutions by 'beta'-ray back-scattering

Energy Technology Data Exchange (ETDEWEB)

Bahadur, A; Maji, K D; Kumar, R [National Metallurgical Lab., Jamshedpur (India)

1975-07-01

This investigation reports the results of a study undertaken to assess the suitability of using the GM counter for measuring the intensity of ..beta..-backscattered radiation to determine the chemical composition of binary solid alloys, and aqueous salt solutions containing a metallic radical. The results indicate that the technique is not suitable for the determination of the composition of binary alloys since the error is in the range of 1.2 to 2.3 wt-% metal. The technique can be conveniently adapted for aqueous salt solutions where the maximum error is approximately 0.2 wt-% metal for metallic elements with atomic number greater than 20.

Plasma beta-endorphin, beta-lipotropin and corticotropin in polycystic ovarian disease.

Science.gov (United States)

Laatikainen, T; Salminen, K; Virtanen, T; Apter, D

1987-04-01

In 9 women with polycystic ovarian disease (PCOD) and in 11 control subjects at the follicular phase of the normal cycle, blood samples were collected at 15-min intervals during a 2 h period of bed rest for the assay of beta-endorphin, beta-lipotropin, corticotropin, cortisol and prolactin. During the study period, the plasma levels of these hormones decreased more significantly in the PCOD than in the control group, suggesting that the PCOD patients had a more significant stress response to the puncture of the vein than the control subjects. The second hour of the study period was considered to represent resting levels of hormones. The mean resting levels (+/- S.E.) of the hormones between the PCOD and control groups, respectively, were as follows: beta-E, 2.0 +/- 0.4 vs. 1.1 +/- 0.1 pmol/l, p less than 0.05; beta-LPH, 3.4 +/- 0.6 vs. 2.1 +/- 0.5 pmol/l, N.S.; corticotropin, 2.0 +/- 0.3 vs. 1.1 +/- 0.5 pmol/l, p less than 0.05; cortisol, 176 +/- 24 vs. 128 +/- 16, N.S.; and prolactin; 3.9 +/- 0.6 vs. 5.6 +/- 1.2 ng/ml, N.S. These results confirm the previous findings on increased circulating levels of beta-E in PCOD. A concomitant increase of the plasma level of corticotropin suggests that the basal secretion of both beta-E and corticotropin from the anterior pituitary gland is increased in women with PCOD.

Cosmic-ray shock acceleration in oblique MHD shocks

Science.gov (United States)

Webb, G. M.; Drury, L. OC.; Volk, H. J.

1986-01-01

A one-dimensional, steady-state hydrodynamical model of cosmic-ray acceleration at oblique MHD shocks is presented. Upstream of the shock the incoming thermal plasma is subject to the adverse pressure gradient of the accelerated particles, the J x B force, as well as the thermal gas pressure gradient. The efficiency of the acceleration of cosmic-rays at the shock as a function of the upstream magnetic field obliquity and upstream plasma beta is investigated. Astrophysical applications of the results are briefly discussed.

On Fuzzy {beta}-I-open sets and Fuzzy {beta}-I-continuous functions

Energy Technology Data Exchange (ETDEWEB)

Keskin, Aynur [Department of Mathematics, Faculty of Science and Arts, Selcuk University, Campus, 42075 Konya (Turkey)], E-mail: akeskin@selcuk.edu.tr

2009-11-15

In this paper, first of all we obtain some properties and characterizations of fuzzy {beta}-I-open sets. After that, we also define the notion of {beta}-I-closed sets and obtain some properties. Lastly, we introduce the notions of fuzzy {beta}-I-continuity with the help of fuzzy {beta}-I-open sets to obtain decomposition of fuzzy continuity.

Clusters of conserved beta cell marker genes for assessment of beta cell phenotype

DEFF Research Database (Denmark)

Martens, Geert A; Jiang, Lei; Hellemans, Karine H

2011-01-01

The aim of this study was to establish a gene expression blueprint of pancreatic beta cells conserved from rodents to humans and to evaluate its applicability to assess shifts in the beta cell differentiated state. Genome-wide mRNA expression profiles of isolated beta cells were compared to those...... of a large panel of other tissue and cell types, and transcripts with beta cell-abundant and -selective expression were identified. Iteration of this analysis in mouse, rat and human tissues generated a panel of conserved beta cell biomarkers. This panel was then used to compare isolated versus laser capture...... microdissected beta cells, monitor adaptations of the beta cell phenotype to fasting, and retrieve possible conserved transcriptional regulators....

Beta decay heat following U-235, U-238 and Pu-239 neutron fission

Science.gov (United States)

Li, Shengjie

1997-09-01

This is an experimental study of beta-particle decay heat from 235U, 239Pu and 238U aggregate fission products over delay times 0.4-40,000 seconds. The experimental results below 2s for 235U and 239Pu, and below 20s for 238U, are the first such results reported. The experiments were conducted at the UMASS Lowell 5.5-MV Van de Graaff accelerator and 1-MW swimming-pool research reactor. Thermalized neutrons from the 7Li(p,n)7Be reaction induced fission in 238U and 239Pu, and fast neutrons produced in the reactor initiated fission in 238U. A helium-jet/tape-transport system rapidly transferred fission fragments from a fission chamber to a low background counting area. Delay times after fission were selected by varying the tape speed or the position of the spray point relative to the beta spectrometer that employed a thin-scintillator-disk gating technique to separate beta-particles from accompanying gamma-rays. Beta and gamma sources were both used in energy calibration. Based on low-energy(energies 0-10 MeV. Measured beta spectra were unfolded for their energy distributions by the program FERD, and then compared to other measurements and summation calculations based on ENDF/B-VI fission-product data performed on the LANL Cray computer. Measurements of the beta activity as a function of decay time furnished a relative normalization. Results for the beta decay heat are presented and compared with other experimental data and the summation calculations.

N-Benzylhydroxylamine addition to beta-aryl enoates. Enantioselective synthesis of beta-aryl-beta-amino acid precursors

Science.gov (United States)

Sibi; Liu

2000-10-19

Chiral Lewis acid catalyzed N-benzylhydroxylamine addition to pyrrolidinone-derived enoates afforded beta-aryl-beta-amino acid derivatives in high enantiomeric purity with moderate to very good chemical efficiency.

Amyloid fibril formation from sequences of a natural beta-structured fibrous protein, the adenovirus fiber.

Science.gov (United States)

Papanikolopoulou, Katerina; Schoehn, Guy; Forge, Vincent; Forsyth, V Trevor; Riekel, Christian; Hernandez, Jean-François; Ruigrok, Rob W H; Mitraki, Anna

2005-01-28

Amyloid fibrils are fibrous beta-structures that derive from abnormal folding and assembly of peptides and proteins. Despite a wealth of structural studies on amyloids, the nature of the amyloid structure remains elusive; possible connections to natural, beta-structured fibrous motifs have been suggested. In this work we focus on understanding amyloid structure and formation from sequences of a natural, beta-structured fibrous protein. We show that short peptides (25 to 6 amino acids) corresponding to repetitive sequences from the adenovirus fiber shaft have an intrinsic capacity to form amyloid fibrils as judged by electron microscopy, Congo Red binding, infrared spectroscopy, and x-ray fiber diffraction. In the presence of the globular C-terminal domain of the protein that acts as a trimerization motif, the shaft sequences adopt a triple-stranded, beta-fibrous motif. We discuss the possible structure and arrangement of these sequences within the amyloid fibril, as compared with the one adopted within the native structure. A 6-amino acid peptide, corresponding to the last beta-strand of the shaft, was found to be sufficient to form amyloid fibrils. Structural analysis of these amyloid fibrils suggests that perpendicular stacking of beta-strand repeat units is an underlying common feature of amyloid formation.

Beta Emission and Bremsstrahlung

Energy Technology Data Exchange (ETDEWEB)

Karpius, Peter Joseph [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

2017-11-13

Bremsstrahlung is continuous radiation produced by beta particles decelerating in matter; different beta emitters have different endpoint energies; high-energy betas interacting with high-Z materials will more likely produce bremsstrahlung; depending on the data, sometimes all you can say is that a beta emitter is present.

Application of inverse models and XRD analysis to the determination of Ti-17 {beta}-phase coefficients of thermal expansion

Energy Technology Data Exchange (ETDEWEB)

Freour, S. [GeM, Institut de Recherche en Genie Civil et Mecanique (UMR CNRS 6183), Universite de Nantes, Ecole Centrale de Nantes, 37 Boulevard de l' Universite, BP 406, 44 602 Saint-Nazaire cedex (France)]. E-mail: freour@crttsn.univ-nantes.fr; Gloaguen, D. [GeM, Institut de Recherche en Genie Civil et Mecanique (UMR CNRS 6183), Universite de Nantes, Ecole Centrale de Nantes, 37 Boulevard de l' Universite, BP 406, 44 602 Saint-Nazaire cedex (France); Francois, M. [Laboratoire des Systemes Mecaniques et d' Ingenierie Simultanee (LASMIS FRE CNRS 2719), Universite de Technologie de Troyes, 12 Rue Marie Curie, BP 2060, 10010 Troyes (France); Guillen, R. [GeM, Institut de Recherche en Genie Civil et Mecanique (UMR CNRS 6183), Universite de Nantes, Ecole Centrale de Nantes, 37 Boulevard de l' Universite, BP 406, 44 602 Saint-Nazaire cedex (France)

2006-04-15

scope of this work is the determination of the coefficients of thermal expansion of the Ti-17 {beta}-phase. A rigorous inverse thermo-elastic self-consistent scale transition micro-mechanical model extended to multi-phase materials was used. The experimental data required for the application of the inverse method were obtained from both the available literature and especially dedicated X-ray diffraction lattice strain measurements performed on the studied ({alpha} + {beta}) two-phase titanium alloy.

Nuclear Matrix Elements for the $\\beta\\beta$ Decay of the $^{76}$Ge

CERN Document Server

Brown, B A; Horoi, M

2015-01-01

The nuclear matrix elements for two-neutrino double-beta (2 n$\\beta\\beta$ ) and zero-neutrino double-beta (0 n$\\beta\\beta$) decay of 76 Ge are evaluated in terms of the configuration interaction (CI), quasiparticle random phase approximation (QRPA) and interacting boson model (IBM) methods. We show that the decomposition of the matrix elements in terms of interemediate states in 74 Ge is dominated by ground state of this nucleus. We consider corrections to the CI results that arise from configurations admixtures involving orbitals out-side of the CI configuration space by using results from QRPA, many-body-perturbation theory, and the connections to related observables. The CI two-neutrino matrix element is reduced due to the inclusion of spin-orbit partners, and to many-body correlations connected with Gamow-Teller beta decay. The CI zero-neutrino matrix element for the heavy neutrino is enhanced due to particle-particle correlations that are connected with the odd-even oscillations in the nuclear masse...

Change in the aldolase activity in rats' hearts after irradiation with. gamma. and. beta. rays

Energy Technology Data Exchange (ETDEWEB)

Kukulyanskaya, M F; Borodina, G N

1973-01-01

The activity of aldolase fructoso-1-phosphate (I) and aldolase fructoso-1, 6-diphosphate (II) has been studied at various periods after total ..gamma.. and ..beta.. irradiation of rats at a dose of 42 rads. It has been shown that after ..gamma.. irradiation the activity of I increases in the supernatant liquid of the heart muscle homogenate, but drops sharply in the nuclei. In total, the activity of the homogenate did not change. The activity of II dropped for seven days, and after 1 hour and 30 days it was above the normal level. After ..beta.. radiation the activity of II is slowed down after 1, 7, and 15 days. These changes occur in all subcellular fractions. The authors note that the changes in the activity of aldolases are more sharply demarcated after ..gamma.. irradiation and are more substantial for II. (JPRS)

Low level GAMMA0 spectrometry by beta-gamma coincidence

International Nuclear Information System (INIS)

Grigorescu, E.L.; Luca, A.; Razdolescu, A.C.; Ivan, C.

1999-01-01

Low level gamma spectrometry has a wide application, especially in environmental monitoring. Two variants, based on a beta-gamma coincidence technique, were studied. The equipment was composed of a beta detector and a Ge(Li) gamma detector (6% - relative efficiency), with the associated electronics. The gamma rays are recorded by the multichannel analyzer (4096 channels) only if the associated beta particles, which precede the gamma transitions, are registered in coincidence. Two types of beta detectors were used: plastic and liquid scintillators. In both cases, an external lead shield of 5 cm thick was used. The integral gamma background (50-1700 KeV) was reduced about 85 and 50 times, respectively. The corresponding MDA (Minimum Detectable Activity) values decreased about 1.5 and (3-7) times, respectively. The 2π sr plastic beta detector was placed on top the Ge(Li). The sample was inserted between the two detectors. The measurement time was 10 4 s. A 4π sr detector, built of the same material, was also studied, but it proved to be less advantageous because the background was reduced only 16 times; for a MDA reduction similar with that of the 2π sr variant, a longer measurement was needed (3.10 4 s). The other type of beta detector used, was a liquid scintillator. The dissolving of the samples in scintillator ensures a 4π sr measurement geometry. The vials with scintillator (10 ml volume) were placed on top the Ge(Li) and visualised by the photocathode of a phototube. This setup was surrounded by an enclosure which prevent the light penetration. The measurement time was 10 4 s. The only difficulty encountered in this low level measurement method is the accurate determination of the beta efficiency. A limitation is the possibility to measure only small mass samples. These variants are more simple and cheaper than others, previously studied. The advantage of the method is obvious when, instead of low MDA values, shorter measurement times are preferred. The

Determination of 131m Xe and 133m Xe in the presence of 133gXe via combined beta-spectroscopy and delayed coincidence

International Nuclear Information System (INIS)

Reeder, Paul L.; Bowyer, Ted W.; McIntyre, Justin I.; Pitts, W K.

2001-01-01

The International Monitoring System for the Comprehensive Nuclear-Test-Ban Treaty will include measurements of Xe fission products. Pacific Northwest National Laboratory has developed an automated system for separating Xe from air which detects Xe fission products using a beta-gamma counting system for 131mXe, 133mXe, 133Xe, and 135Xe. Betas and conversion electrons are detected in a plastic scintillation cell containing the Xe sample. Gamma and X-rays are detected in a NaI(Tl) scintillation detector which surrounds the plastic scintillator sample cell. Two-dimensional pulse height spectra of gamma energy versus beta energy are obtained. The plastic scintillator spectrum in coincidence with the 31-keV X-rays from 131mXe. 133mXe, and 133Xe is a complex mixture of conversion electrons and betas. A new technique to simultaneously measure the delayed coincidence (t1/2 = 6.27 ns) between beta particles from 133Xe and conversion electrons depopulating the 81-keV state in 133Cs is being developed. This technique will allow separation of the 133Xe spectrum from the conversion electrons due to 131mXe and 133mXe and will uniquely quantify all three nuclides

Empirical model for the Earth's cosmic ray shadow at 400 KM: prohibited cosmic ray access

International Nuclear Information System (INIS)

Humble, J.E.; Smart, D.F.; Shea, M.A.

1985-01-01

The possibility of constructing a unit sphere of access that describes the cosmic radiation allowed to an Earth-orbiting spacecraft is discussed. It is found that it is possible to model the occluded portion of the cosmic ray sphere of access as a circular projection with a diameter bounded by the satellite-Earth horizon. Maintaining tangency at the eastern edge of the spacecraft-Earth horizon, this optically occluded area is projected downward by an angle beta which is a function of the magnetic field inclination and cosmic ray arrival direction. This projected plane, corresponding to the forbidden area of cosmic ray access, is bounded by the spacecraft-Earth horizon in easterly directions, and is rotated around the vertical axis by an angle alpha from the eastern direction, where the angle alpha is a function of the offset dipole latitude of the spacecraft

Production of beta-xylanase and beta-xylosidase by the extremely halophilic archaeon Halorhabdus utahensis

DEFF Research Database (Denmark)

Wainø, M.; Ingvorsen, K.

2003-01-01

-xylosidase stabilities, approximately 55% and 83% of the initial beta-xylanase and beta-xylosidase activities, respectively, remained after 24 h incubation at 20% NaCl. The enzymes were also shown to be slightly thermophilic: P-xylanase activity exhibiting two optima at 55degrees and 70degreesC, while beta......The extremely halophilic archaeon, Halorhabdus utahensis, isolated from the Great Salt Lake, Utah, produced beta-xylanase and beta-xylosidase activities. Both enzymes were active over a broad NaCl range from near zero to 30% NaCl when tested with culture broth. A broad NaCl optimum was observed...... for beta-xylanase activity between 5% and 15% NaCl, while beta-xylosidase activity was highest at 5% NaCl. Almost half of the maximum activities remained at 27%-30% NaCl for both enzyme activities. When dialyzed culture supernatant and culture broth were employed for determination of beta-xylanase and beta...

Role of beta-adrenoceptors in memory consolidation: beta3-adrenoceptors act on glucose uptake and beta2-adrenoceptors on glycogenolysis.

Science.gov (United States)

Gibbs, Marie E; Hutchinson, Dana S; Summers, Roger J

2008-09-01

Noradrenaline, acting via beta(2)- and beta(3)-adrenoceptors (AR), enhances memory formation in single trial-discriminated avoidance learning in day-old chicks by mechanisms involving changes in metabolism of glucose and/or glycogen. Earlier studies of memory consolidation in chicks implicated beta(3)- rather than beta(2)-ARs in enhancement of memory consolidation by glucose, but did not elucidate whether stimulation of glucose uptake or of glycolysis was responsible. This study examines the role of glucose transport in memory formation using central injection of the nonselective facilitative glucose transporter (GLUT) inhibitor cytochalasin B, the endothelial/astrocytic GLUT-1 inhibitor phloretin and the Na(+)/energy-dependent endothelial glucose transporter (SGLT) inhibitor phlorizin. Cytochalasin B inhibited memory when injected into the mesopallium (avian cortex) either close to or between 25 and 45 min after training, whereas phloretin and phlorizin only inhibited memory at 30 min. This suggested that astrocytic/endothelial (GLUT-1) transport is critical at the time of consolidation, whereas a different transporter, probably the neuronal glucose transporter (GLUT-3), is important at the time of training. Inhibition of glucose transport by cytochalasin B, phloretin, or phlorizin also interfered with beta(3)-AR-mediated memory enhancement 20 min posttraining, whereas inhibition of glycogenolysis interfered with beta(2)-AR agonist enhancement of memory. We conclude that in astrocytes (1) activities of both GLUT-1 and SGLT are essential for memory consolidation 30 min posttraining; (2) neuronal GLUT-3 is essential at the time of training; and (3) beta(2)- and beta(3)-ARs consolidate memory by different mechanisms; beta(3)-ARs stimulate central glucose transport, whereas beta(2)-ARs stimulate central glycogenolysis.

Low-beta investment strategies

OpenAIRE

Korn, Olaf; Kuntz, Laura-Chloé

2015-01-01

This paper investigates investment strategies that exploit the low-beta anomaly. Although the notion of buying low-beta stocks and selling high-beta stocks is natural, a choice is necessary with respect to the relative weighting of high-beta stocks and low-beta stocks in the investment portfolio. Our empirical results for US large-cap stocks show that this choice is very important for the risk-return characteristics of the resulting portfolios and their sensitivities to common risk factors. W...

Ellagic acid promotes A{beta}42 fibrillization and inhibits A{beta}42-induced neurotoxicity

Energy Technology Data Exchange (ETDEWEB)

Feng, Ying [Department of Histology and Embryology, College of Basic Medical Science, China Medical University, Shenyang 110001 (China); Tsinghua University School of Medicine, Haidian District, Beijing 100084 (China); Yang, Shi-gao; Du, Xue-ting; Zhang, Xi; Sun, Xiao-xia; Zhao, Min [Tsinghua University School of Medicine, Haidian District, Beijing 100084 (China); Sun, Gui-yuan, E-mail: sungy2004@sohu.com [Department of Histology and Embryology, College of Basic Medical Science, China Medical University, Shenyang 110001 (China); Liu, Rui-tian, E-mail: rtliu@tsinghua.edu.cn [Tsinghua University School of Medicine, Haidian District, Beijing 100084 (China)

2009-12-25

Smaller, soluble oligomers of {beta}-amyloid (A{beta}) play a critical role in the pathogenesis of Alzheimer's disease (AD). Selective inhibition of A{beta} oligomer formation provides an optimum target for AD therapy. Some polyphenols have potent anti-amyloidogenic activities and protect against A{beta} neurotoxicity. Here, we tested the effects of ellagic acid (EA), a polyphenolic compound, on A{beta}42 aggregation and neurotoxicity in vitro. EA promoted A{beta} fibril formation and significant oligomer loss, contrary to previous results that polyphenols inhibited A{beta} aggregation. The results of transmission electron microscopy (TEM) and Western blot displayed more fibrils in A{beta}42 samples co-incubated with EA in earlier phases of aggregation. Consistent with the hypothesis that plaque formation may represent a protective mechanism in which the body sequesters toxic A{beta} aggregates to render them harmless, our MTT results showed that EA could significantly reduce A{beta}42-induced neurotoxicity toward SH-SY5Y cells. Taken together, our results suggest that EA, an active ingredient in many fruits and nuts, may have therapeutic potential in AD.

The GSF secondary standard dosimetry laboratory for photon and beta radiation

International Nuclear Information System (INIS)

Eckerl, H.; Nahrstedt, U.

1986-03-01

A brief outline of the laboratory's tasks and a detailed description of its layout and equipment is given. The laboratory contains a Co-60 irradiation unit, a Cs-137 irradiation unit, a panoramic irradiation unit for different nuclide sources, a 160- and 420 kV X-ray unit, a beta-irradiation unit and a measuring and control room. The calibration laboratory is equipped with reference and field dosemeters. (DG)

Evolution of Substrate Specificity within a Diverse Family of [beta/alpha]-Barrel-fold Basic Amino Acid Decarboxylases X-ray Structure Determination of Enzymes with Specificity for L-Arginine and Carboxynorspermidine

Energy Technology Data Exchange (ETDEWEB)

Deng, Xiaoyi; Lee, Jeongmi; Michael, Anthony J.; Tomchick, Diana R.; Goldsmith, Elizabeth J.; Phillips, Margaret A. (Sungkyunkwan); (UTSMC)

2010-08-26

Pyridoxal 5{prime}-phosphate (PLP)-dependent basic amino acid decarboxylases from the {beta}/{alpha}-barrel-fold class (group IV) exist in most organisms and catalyze the decarboxylation of diverse substrates, essential for polyamine and lysine biosynthesis. Herein we describe the first x-ray structure determination of bacterial biosynthetic arginine decarboxylase (ADC) and carboxynorspermidine decarboxylase (CANSDC) to 2.3- and 2.0-{angstrom} resolution, solved as product complexes with agmatine and norspermidine. Despite low overall sequence identity, the monomeric and dimeric structures are similar to other enzymes in the family, with the active sites formed between the {beta}/{alpha}-barrel domain of one subunit and the {beta}-barrel of the other. ADC contains both a unique interdomain insertion (4-helical bundle) and a C-terminal extension (3-helical bundle) and it packs as a tetramer in the asymmetric unit with the insertions forming part of the dimer and tetramer interfaces. Analytical ultracentrifugation studies confirmed that the ADC solution structure is a tetramer. Specificity for different basic amino acids appears to arise primarily from changes in the position of, and amino acid replacements in, a helix in the {beta}-barrel domain we refer to as the 'specificity helix.' Additionally, in CANSDC a key acidic residue that interacts with the distal amino group of other substrates is replaced by Leu{sup 314}, which interacts with the aliphatic portion of norspermidine. Neither product, agmatine in ADC nor norspermidine in CANSDC, form a Schiff base to pyridoxal 5{prime}-phosphate, suggesting that the product complexes may promote product release by slowing the back reaction. These studies provide insight into the structural basis for the evolution of novel function within a common structural-fold.

Rapid synthesis of beta zeolites

Science.gov (United States)

Fan, Wei; Chang, Chun -Chih; Dornath, Paul; Wang, Zhuopeng

2015-08-18

The invention provides methods for rapidly synthesizing heteroatom containing zeolites including Sn-Beta, Si-Beta, Ti-Beta, Zr-Beta and Fe-Beta. The methods for synthesizing heteroatom zeolites include using well-crystalline zeolite crystals as seeds and using a fluoride-free, caustic medium in a seeded dry-gel conversion method. The Beta zeolite catalysts made by the methods of the invention catalyze both isomerization and dehydration reactions.

Active-site-directed inactivation of Aspergillus oryzae beta-galactosidase with beta-D-galactopyranosylmethyl-p-nitrophenyltriazene.

Science.gov (United States)

Mega, T; Nishijima, T; Ikenaka, T

1990-04-01

beta-D-Galactopyranosylmethyl-p-nitrophenyltriazene (beta-GalMNT), a specific inhibitor of beta-galactosidase, was isolated as crystals by HPLC and its chemical and physicochemical characteristics were examined. Aspergillus oryzae beta-galactosidase was inactivated by the compound. We studied the inhibition mechanism in detail. The inhibitor was hydrolyzed by the enzyme to p-nitroaniline and an active intermediate (beta-galactopyranosylmethyl carbonium or beta-galactopyranosylmethyldiazonium), which inactivated the enzyme. The efficiency of inactivation of the enzyme (the ratio of moles of inactivated enzyme to moles of beta-GalMNT hydrolyzed by the enzyme) was 3%; the efficiency of Escherichia coli beta-galactosidase was 49%. In spite of the low efficiency, the rate of inactivation of A. oryzae enzyme was not very different from that of the E. coli enzyme, because the former hydrolyzed beta-GalMNT faster than the latter did. A. oryzae beta-galactosidase was also inactivated by p-chlorophenyl, p-tolyl, and m-nitrophenyl derivatives of beta-galactopyranosylmethyltriazene. However, E. coli beta-galactosidase was not inactivated by these triazene derivatives. The results showed that the inactivation of A. oryzae and E. coli beta-galactosidases by beta-GalMNT was an enzyme-activated and active-site-directed irreversible inactivation. The possibility of inactivation by intermediates produced nonenzymatically was ruled out for E. coli, but not for the A. oryzae enzyme.

Magnetic moment of $^{17}$Ne using beta -NMR and tilted foil polarization

CERN Document Server

Baby, L T; Hass, M; Haas, H; Weissman, L; Brown, B A

2004-01-01

We report on the measurement of the magnetic moment of the ground state of /sup 17/Ne. Radioactive /sup 17/Ne nuclei were delivered from the high resolution mass separator at ISOLDE onto a high voltage platform at -200 kV and were polarized using the tilted foil polarization method. The polarized nuclei were implanted into a Pt stopper situated in a liquid-helium cooled beta -NMR apparatus and the asymmetry destruction of the ensuing beta rays was monitored as a function of the rf frequency applied to the polarized nuclei. The measured value of mu = 0.74 +or- 0.03 affirms the nu p/sub 1/2//sup - / nature of the ground state of /sup 17/Ne and is compared to shell model calculations. (10 refs).

Maternal plasma concentrations of beta-lipotrophin, beta-endorphin and gamma-lipotrophin throughout pregnancy.

Science.gov (United States)

Browning, A J; Butt, W R; Lynch, S S; Shakespear, R A

1983-12-01

Plasma beta-LPH, beta-EP and gamma-LPH concentrations were measured by radioimmunoassay in 10 pregnant women from 12 weeks gestation until term and in nine women in the early follicular phase of the cycle. There was a progressive and significant rise in the concentration of all three peptides throughout pregnancy and by 32 weeks the concentrations of beta-LPH and beta-EP were greater than the corresponding concentrations in the follicular phase: gamma-LPH was greater than in the follicular phase by the end of pregnancy in those women who were delivered after 40 weeks. The ratio of beta-LPH to gamma-LPH did not change significantly throughout pregnancy, but there was a progressive fall in the beta-LPH/beta-EP ratio. The possible presence of a 'big LPH' to explain this finding is discussed.

Optimized formation of detergent micelles of beta-carotene and retinal production using recombinant human beta,beta-carotene 15,15'-monooxygenase.

Science.gov (United States)

Kim, Nam-Hee; Kim, Yeong-Su; Kim, Hye-Jung; Oh, Deok-Kun

2008-01-01

The formation of beta-carotene detergent micelles and their conversion into retinal by recombinant human beta,beta-carotene 15,15'-monooxygenase was optimized under aqueous conditions. Toluene was the most hydrophobic among the organic solvents tested; thus, it was used to dissolve beta-carotene, which is a hydrophobic compound. Tween 80 was selected as the detergent because it supported the highest level of retinal production among all of the detergents tested. The maximum production of retinal was achieved in detergent micelles containing 200 mg/L of beta-carotene and 2.4% (w/v) Tween 80. Under these conditions, the recombinant enzyme produced 97 mg/L of retinal after 16 h with a conversion yield of 48.5% (w/w). The amount of retinal produced, which is the highest ever reported, is a result of the ability of our system to dissolve large amounts of beta-carotene.

Precision study of the $\\beta$-decay of $^{74}$Rb

CERN Multimedia

Van Duppen, P L E; Lunney, D

2002-01-01

We are proposing a high-resolution study of the $\\beta$-decay of $^{74}$Rb in order to extrapolate our precision knowledge of the superallowed $\\beta$-decays from the sd and fp shells towards the medium-heavy Z=N nuclei. The primary goal is to provide new data for testing the CVC hypothesis and the unitarity condition of the CKM matrix of the Standard Model. The presented programme would involve the careful measurements of the decay properties of $^{74}$Rb including the branching ratios to the excited states as well as the precise determination of the decay energy of $^{74}$Rb. The experimental methods readily available at ISOLDE include high-transmission conversion electron spectroscopy, $\\gamma$-ray spectroscopy as well as the measurements of the masses of $^{74}$Rb and $^{74}$Kr using two complementary techniques, ISOLTRAP and MISTRAL. The experiment would rely on a high-quality $^{74}$Rb beam available at ISOLDE with adequate intensity.

Beta cell adaptation in pregnancy

DEFF Research Database (Denmark)

Nielsen, Jens Høiriis

2016-01-01

Pregnancy is associated with a compensatory increase in beta cell mass. It is well established that somatolactogenic hormones contribute to the expansion both indirectly by their insulin antagonistic effects and directly by their mitogenic effects on the beta cells via receptors for prolactin...... and growth hormone expressed in rodent beta cells. However, the beta cell expansion in human pregnancy seems to occur by neogenesis of beta cells from putative progenitor cells rather than by proliferation of existing beta cells. Claes Hellerström has pioneered the research on beta cell growth for decades...... in the expansion of the beta cell mass in human pregnancy, and the relative roles of endocrine factors and nutrients....

Thermoluminescent dosimetry of new phosphors of Zn O exposed to beta radiation

International Nuclear Information System (INIS)

Cruz V, C.; Burruel I, S.E.; Grijalva M, H.; Barboza F, M.; Bernal, R.

2004-01-01

In this work, we report the thermoluminescence dosimetry of a new Zn O phosphor obtained by annealing of Zn S powder precipitated when Zn S films were grown by employing a CBD method. The collected Zn S powder was pressed in a die to form pellets which were subjected to different thermal treatments under air atmosphere. X-ray diffraction (XRD) patterns and energy-dispersive X-ray Spectrometry (EDS) analyses confirmed the transformation of Zn S to Zn O. The phosphors thus obtained were exposed to high doses of beta radiation and their thermoluminescent dosimetry show that these new phosphors are materials suitable to be used in high dose thermoluminescence dosimetry. (Author)

X-ray powder diffraction analysis of liquid-phase-sintered silicon carbide ceramics

Energy Technology Data Exchange (ETDEWEB)

Ortiz, A.L.; Sanchez-Bajo, F. [Universidad de Extremadura, Badajoz (Spain). Dept. de Electronica e Ingenieria Electromecanica; Cumbrera, F.L. [Universidad de Extremadura, Badajoz (Spain). Dept. de Fisica

2002-07-01

In an attempt to gain a comprehensive understanding of the microstructural evolution in liquid-phase-sintered silicon carbide ceramics, the effect of the starting {beta}-SiC powder has been studied. Pellets of two different {beta}-SiC starting powders were sintered with simultaneous additions of Al{sub 2}O{sub 3} and Y{sub 2}O{sub 3} at 1950 C for 1 hour in flowing argon atmosphere. Here we have used X-ray diffraction to obtain the relative abundance of the resulting SiC polytypes after sintering. The significant influence of the defects concentration on the {beta} to {alpha} transformation rate has been determined using the Rietveld method. (orig.)

Beta spectrometry

International Nuclear Information System (INIS)

Dryak, P.; Zderadicka, J.; Plch, J.; Kokta, L.; Novotna, P.

1977-01-01

For the purpose of beta spectrometry, a semiconductor spectrometer with one Si(Li) detector cooled with liquid nitrogen was designed. Geometrical detection efficiency is about 10% 4 sr. The achieved resolution for 624 keV conversion electrons of sup(137m)Ba is 2.6 keV (FWHM). A program was written in the FORTRAN language for the correction of the deformation of the measured spectra by backscattering in the analysis of continuous beta spectra. The method permits the determination of the maximum energy of the beta spectrum with an accuracy of +-5 keV. (author)

DMPD: Immunoreceptor-like signaling by beta 2 and beta 3 integrins. [Dynamic Macrophage Pathway CSML Database

Lifescience Database Archive (English)

Full Text Available 17913496 Immunoreceptor-like signaling by beta 2 and beta 3 integrins. Jakus Z, Fod...) Show Immunoreceptor-like signaling by beta 2 and beta 3 integrins. PubmedID 17913496 Title Immunoreceptor-...like signaling by beta 2 and beta 3 integrins. Authors Jakus Z, Fodor S, Abram CL

Identification of active anti-inflammatory principles of beta- beta ...

African Journals Online (AJOL)

chromatography. Components of the extracts were identified by thin layer chromatography (TLC) scanner and UV-visible spectroscopy, using scopoletin as standard. Results: ... basic coumarin skeleton ring structure reduce ... Figure 2: Thin-layer chromatogram: (1) Ethanol extract; (2) Dichloromethane fraction; (3) Beta-beta.

Dimers of beta 2-glycoprotein I mimic the in vitro effects of beta 2-glycoprotein I-anti-beta 2-glycoprotein I antibody complexes

NARCIS (Netherlands)

Lutters, B. C.; Meijers, J. C.; Derksen, R. H.; Arnout, J.; de Groot, P. G.

2001-01-01

Anti-beta(2)-glycoprotein I antibodies are thought to cause lupus anticoagulant activity by forming bivalent complexes with beta(2)-glycoprotein I (beta(2)GPI). To test this hypothesis, chimeric fusion proteins were constructed of the dimerization domain (apple 4) of factor XI and beta(2)GPI. Both a

Exercise- and cold-induced changes in plasma beta-endorphin and beta-lipotropin in men and women.

Science.gov (United States)

Viswanathan, M; Van Dijk, J P; Graham, T E; Bonen, A; George, J C

1987-02-01

The plasma beta-endorphin (beta-EP) and beta-lipotropin (beta-LPH) response of men, eumenorrheic women, and amenorrheic women (n = 6) to 1 h of rest or to a bicycle ergometer test [20 min at 30% maximum O2 uptake (VO2max), 20 min at 60% VO2max, and at 90% VO2max to exhaustion] was studied in both normal (22 degrees C) and cold (5 degrees C) environments. beta-EP and beta-LPH was measured by radioimmunoassay in venous samples collected every 20 min during rest or after each exercise bout. Exhaustive exercise at ambient temperature (Ta) 22 degrees C induced significant increases in plasma beta-EP and beta-LPH in all subjects as did work at 60% VO2max in amenorrheic and eumenorrheic women. During work at Ta 5 degrees C, the relative increase in beta-EP and beta-LPH was suppressed in eumenorrheic women and completely prevented in amenorrheic women. Although significant lowering of beta-EP and beta-LPH was observed in men and eumenorrheic women during rest at 5 degrees C, amenorrheic women maintained precold exposure levels. These findings suggest that plasma beta-EP and beta-LPH may reflect a thermoregulatory response to heat load. There appears to be a sexual dimorphism in exercise- and cold-induced release of beta-EP and beta-LPH and amenorrhea may be accompanied by alterations in these responses.

$\\beta$ decay of $^{47}$Ar

CERN Document Server

Weissman, L; Bergmann, U C; Brown, B A; Catherall, R; Cederkäll, J; Dillmann, I; Hallmann, O; Fraile-Prieto, L M; Franchoo, S; Gaudefroy, L; Köster, U; Kratz, K L; Pfeiffer, B; Sorlin, O; 10.1103/PhysRevC.70.024304

2004-01-01

Information on beta -decay properties of neutron-rich /sup 47/Ar was obtained at the ISOLDE facility at CERN using isobaric selectivity. This was achieved by a combination of a plasma-ion source with a cooled transfer line and subsequent mass separation. A doubly charged beam was used in order to improve the signal-to-background ratio associated with multi-charged noble gas fission products. The identification of the /sup 47/Ar gamma -ray transitions was performed by comparing the spectra obtained from direct proton bombardment of the target and of the neutron converter. New excited levels in the daughter /sup 47/K nucleus corresponding to the negative-parity states were observed. The obtained data are compared to the result of large-scale shell model calculations and quasiparticle random-phase approximation predictions. (29 refs).

TL glow curve analysis of UV, beta and gamma induced limestone collected from Amarnath holy cave

Directory of Open Access Journals (Sweden)

Vikas Dubey

2015-01-01

Full Text Available The paper reports themoluminescence glow curve analysis of UV (ultraviolet, β (beta and γ (gamma induced limestone collected from Amarnath holy cave. The collected natural sample was characterized by X-ray diffraction (XRD technique and crystallite size calculated by Scherer's formula. Surface morphology and particle size was calculated by transmission electron microscopy (TEM study. Effect of annealing temperature on collected lime stone examined by TL glow curve study. The limestone was irradiated by UV radiation (254 nm source and the TL glow curve recorded for different UV exposure time. For beta irradiation Sr90 source was used and is shows intense peak at 256 °C with a shoulder peak at higher temperature range. For gamma radiation Co60 source and TL glow curve recorded for different doses of gamma. The kinetic parameters calculation was performed for different glow curve by computerized glow curve deconvolution (CGCD technique. The chemical composition of natural limestone was analyzed by energy dispersive X-ray spectroscopy (EDXS.

beta-Thalassemia present in cis to a new beta-chain structural variant, Hb Vicksburg [beta 75 (E19)Leu leads to 0].

Science.gov (United States)

Adams, J G; Steinberg, M H; Newman, M V; Morrison, W T; Benz, E J; Iyer, R

1981-01-01

Hemoglobin Vicksburg was discovered in a 6-year-old Black boy who had been anemic since infancy. Examination of his hemolysate revealed 87.5% Hb F, 2.4% Hb A2, and 7.6% Hb Vicksburg, which had the electrophoretic and chromatographic properties of Hb A. Structural analysis of Hb Vicksburg demonstrated a deletion of leucine at beta 75(E19), a new variant. Hb Vicksburg was neither unstable nor subject to posttranslational degradation. The alpha/non-alpha biosynthetic ratio was 2.6. Because the proband appeared to be a mixed heterozygote for Hb Vicksburg and beta 0-thalassemia, Hb Vicksburg should have comprised the major portion of the hemolysate. Thus, Hb Vicksburg was synthesized at a rate considerably lower than would be expected on the basis of gene dosage. There was no reason to suspect abnormal translation of beta Vicksburg mRNA; in individuals with Hb St. Antoine (beta 74 and beta 75 deleted), the abnormal hemoglobin comprised 25% of the hemolysate in the simple heterozygote yet was unstable. Deletion of beta 75, therefore, would not in itself appear to lead to diminished synthesis. There was a profound deficit of beta Vicksburg mRNA when measured by liquid hybridization analysis with beta cDNA. The most plausible explanation for the low output of Hb Vicksburg is that a mutation for beta +-thalassemia is present in cis to the structural mutation.

Clusters of conserved beta cell marker genes for assessment of beta cell phenotype

DEFF Research Database (Denmark)

Martens, Geert A; Jiang, Lei; Hellemans, Karine H

2011-01-01

The aim of this study was to establish a gene expression blueprint of pancreatic beta cells conserved from rodents to humans and to evaluate its applicability to assess shifts in the beta cell differentiated state. Genome-wide mRNA expression profiles of isolated beta cells were compared to those...... of a large panel of other tissue and cell types, and transcripts with beta cell-abundant and -selective expression were identified. Iteration of this analysis in mouse, rat and human tissues generated a panel of conserved beta cell biomarkers. This panel was then used to compare isolated versus laser capture...

Crystallization and preliminary X-ray analysis of beta-alanine synthase from the yeast Saccharomyces kluyveri

DEFF Research Database (Denmark)

Dobritzsch, D.; Gojkovic, Zoran; Andersen, Birgit

2003-01-01

In eukaryotes and some bacteria, the third step of reductive pyrimidine catabolism is catalyzed by beta-alanine synthase (EC 3.5.1.6). Crystals of the recombinant enzyme from the yeast Saccharomyces kluyveri were obtained using sodium citrate as a precipitant. The crystals belong to space group P2...

beta-Carotene in breast milk and serum is increased after a single beta-carotene dose.

Science.gov (United States)

Canfield, L M; Giuliano, A R; Neilson, E M; Yap, H H; Graver, E J; Cui, H A; Blashill, B M

1997-07-01

Normal lactating mothers were administered a single dose of 60 or 210 mg beta-carotene and changes in serum and milk retinol, alpha-tocopherol, and carotenoids were monitored for 8 d. Average serum beta-carotene concentrations increased 4.1- and 4.0-fold after the 60- and 210-mg doses, respectively. Milk beta-carotene concentrations increased 4.1- and 3.0-fold after the 60- and 210-mg doses, respectively. Maximum serum concentrations were reached 24 h after both supplements, although concentrations of milk beta-carotene continued to rise for 2-3 d. After 8 d, both serum and milk beta-carotene continued to rise for 2-3 d. After 8 d, both serum and milk beta-carotene concentrations remained about twofold higher than baseline concentrations. Increases in serum or milk beta-carotene concentrations were not dose-dependent. Initial serum and milk concentrations of beta-carotene predicted increases after supplementation, and increases in serum beta-carotene concentrations predicted those in milk. Concentrations of milk carotenoids were less than one-tenth their respective concentrations in serum. Lutein, beta-cryptoxanthin, lycopene, alpha-carotene, retinol, and alpha-tocopherol concentrations in serum or milk did not change significantly after beta-carotene supplementation. Retinol esters account for most of the retinol equivalents in the milk of well-nourished mothers. Initial and maximum concentrations of beta-carotene in serum and milk were strongly correlated for individual mothers. Collectively, the data showed that a single 60-mg supplement of beta-carotene sustained elevated beta-carotene concentrations in serum and milk for > 1 wk in normal mothers but did not affect concentrations of other major carotenoids, retinol, or alpha-tocopherol.

Beta Thalassemia (For Parents)

Science.gov (United States)

... Safe Videos for Educators Search English Español Beta Thalassemia KidsHealth / For Parents / Beta Thalassemia What's in this ... Symptoms Diagnosis Treatment Print en español Beta talasemia Thalassemias Thalassemias are a group of blood disorders that ...

Absolute disintegration rate and 320 keV {gamma}-ray emission probability of {sup 51}Cr

Energy Technology Data Exchange (ETDEWEB)

Almeida, M.C.M. de [Laboratorio Nacional de Metrologia das Radiacoes Ionizantes /Instituto de Radioprotecao e Dosimetria (LNMRI/ IRD), Avenida Salvador Allende, s/no. Recreio-Rio de Janeiro, CEP 22780-160 (Brazil)], E-mail: candida@ird.gov.br; Iwahara, A.; Poledna, R.; Silva, C.J. da; Delgado, J.U. [Laboratorio Nacional de Metrologia das Radiacoes Ionizantes /Instituto de Radioprotecao e Dosimetria (LNMRI/ IRD), Avenida Salvador Allende, s/no. Recreio-Rio de Janeiro, CEP 22780-160 (Brazil)

2007-09-21

This work describes the procedures for determining absolutely the {sup 51}Cr disintegration rate by using the 4{pi}{beta}-{gamma} coincidence and anti-coincidence counting and the sum-peak methods. A 4''x4''-NaI(Tl) scintillation detector was used in the {gamma}- channel of the 4{pi}{beta}-{gamma} coincidence system for {gamma}-ray counting. In the {beta}-channel, a 4{pi} gas flow proportional counter was used for counting of characteristic X-rays and Auger electrons originating from the electron capture events of the {sup 51}Cr decay scheme. Gamma spectrometry measurements by high-pure planar and coaxial germanium detectors were performed in the sum-peak method and in the determination of the 320 keV {gamma}-emission probability of {sup 51}Cr. This latter determined value agrees with the recent values found in the literature, confirming the reliability of the three methods used in this work for the disintegration rate measurements.

Crystal Structure of Human [Beta]-Hexosaminidase B: Understanding the Molecular Basis of Sandhoff and Tay-Sachs Disease

Energy Technology Data Exchange (ETDEWEB)

Mark, Brian L.; Mahuran, Don J.; Cherney, Maia M.; Zhao, Dalian; Knapp, Spencer; James, Michael N.G.

2010-12-01

In humans, two major {beta}-hexosaminidase isoenzymes exist: Hex A and Hex B. Hex A is a heterodimer of subunits {alpha} and {beta} (60% identity), whereas Hex B is a homodimer of {beta}-subunits. Interest in human {beta}-hexosaminidase stems from its association with Tay-Sachs and Sandhoff disease; these are prototypical lysosomal storage disorders resulting from the abnormal accumulation of G{sub M2}-ganglioside (G{sub M2}). Hex A degrades G{sub M2} by removing a terminal N-acetyl-D-galactosamine ({beta}-GalNAc) residue, and this activity requires the G{sub M2}-activator, a protein which solubilizes the ganglioside for presentation to Hex A. We present here the crystal structure of human Hex B, alone (2.4 {angstrom}) and in complex with the mechanistic inhibitors GalNAc-isofagomine (2.2 {angstrom}) or NAG-thiazoline (2.5 {angstrom}). From these, and the known X-ray structure of the G{sub M2}-activator, we have modeled Hex A in complex with the activator and ganglioside. Together, our crystallographic and modeling data demonstrate how {alpha} and {beta}-subunits dimerize to form either Hex A or Hex B, how these isoenzymes hydrolyze diverse substrates, and how many documented point mutations cause Sandhoff disease ({beta}-subunit mutations) and Tay-Sachs disease ({alpha}-subunit mutations).

Study of the Nuclear Structure of 39P Using Beta-Delayed Gamma Spectroscopy

Science.gov (United States)

Abromeit, Brittany; NSCL Experiment E14063 Team Team

2016-03-01

Investigation of nuclei with neutron and proton imbalance is at the forefront of nuclear physics research today. This is driven by the fact that the structure in these regimes may vary with that seen near the valley of stability. With eight neutrons more than the stable isotope of phosphorous, 39P is a neutron-rich exotic nucleus that has very limited information on it: previous studies of 39P produce only three known energy levels and gamma rays. The fragmentation of a 48Ca primary beam on a 564mg/cm2 thick Be target at the National Superconducting Cyclotron Laboratory (NSCL) was used to produce exotic 39Si. Using the NSCL Beta Counting System (BCS), consisting of a thick planner germanium double-sided strip detector (GeDSSD) and 16 High-purity germanium detectors in an array, SeGA, the beta-gamma coincidences from the decay of 39Si to 39P were analyzed. The resulting level scheme of 39P, including over 12 new gamma rays and energy states, confirmation of the previously measured half-life, and first-time logft values will be presented. This work was supported by the NSF under Grant No. 1401574.

GRAP, Gamma-Ray Level-Scheme Assignment

International Nuclear Information System (INIS)

Franklyn, C.B.

2002-01-01

1 - Description of program or function: An interactive program for allocating gamma-rays to an energy level scheme. Procedure allows for searching for new candidate levels of the form: 1) L1 + G(A) + G(B) = L2; 2) G(A) + G(B) = G(C); 3) G(A) + G(B) = C (C is a user defined number); 4) L1 + G(A) + G(B) + G(C) = L2. Procedure indicates intensity balance of feed and decay of each energy level. Provides for optimization of a level energy (and associated error). Overall procedure allows for pre-defining of certain gamma-rays as belonging to particular regions of the level scheme, for example, high energy transition levels, or due to beta- decay. 2 - Method of solution: Search for cases in which the energy difference between two energy levels is equal to a gamma-ray energy within user-defined limits. 3 - Restrictions on the complexity of the problem: Maximum number of gamma-rays: 999; Maximum gamma ray energy: 32000 units; Minimum gamma ray energy: 10 units; Maximum gamma-ray intensity: 32000 units; Minimum gamma-ray intensity: 0.001 units; Maximum number of levels: 255; Maximum level energy: 32000 units; Minimum level energy: 10 units; Maximum error on energy, intensity: 32 units; Minimum error on energy, intensity: 0.001 units; Maximum number of combinations: 6400 (ca); Maximum number of gamma-ray types : 127

Oxidative dehydration of glycerol to acrylic acid over vanadium-impregnated zeolite beta

Energy Technology Data Exchange (ETDEWEB)

Pestana, Carolina F.M.; Guerra, Antonio C.O.; Turci, Cassia C. [Universidade Federal do Rio de Janeiro, RJ (Brazil). Inst. de Quimica; Ferreira, Glaucio B. [Universidade Federal Fluminense, Niteroi, RJ (Brazil). Inst. de Quimica; Mota, Claudio J.A., E-mail: cmota@iq.ufrj.br [INCT Energia e Ambiente, Universidade Federal do Rio de Janeiro, RJ (Brazil)

2013-01-15

The oxidative dehydration of glycerol to acrylic acid was studied over vanadium-impregnated zeolite Beta. Catalysts were prepared by wet impregnation of ammonium metavanadate over ammonium-exchanged zeolite Beta, followed by air calcination at 823 K. Impregnation reduced the specific surface area, but did not significantly affected the acidity (Bronsted and Lewis) of the zeolites. The catalytic evaluation was carried out in a fixed bed flow reactor using air as the carrier and injecting glycerol by means of a syringe pump. Acrolein was the main product, with acetaldehyde and hydroxy-acetone (acetol) being also formed. Acrylic acid was formed with approximately 25% selectivity at 548 K over the impregnated zeolites. The result can be explained by XPS (X-ray photoelectron spectroscopy) measurements, which indicated a good dispersion of the vanadium inside the pores. (author)

Oxidative dehydration of glycerol to acrylic acid over vanadium-impregnated zeolite beta

International Nuclear Information System (INIS)

Pestana, Carolina F.M.; Guerra, Antonio C.O.; Turci, Cassia C.

2013-01-01

The oxidative dehydration of glycerol to acrylic acid was studied over vanadium-impregnated zeolite Beta. Catalysts were prepared by wet impregnation of ammonium metavanadate over ammonium-exchanged zeolite Beta, followed by air calcination at 823 K. Impregnation reduced the specific surface area, but did not significantly affected the acidity (Bronsted and Lewis) of the zeolites. The catalytic evaluation was carried out in a fixed bed flow reactor using air as the carrier and injecting glycerol by means of a syringe pump. Acrolein was the main product, with acetaldehyde and hydroxy-acetone (acetol) being also formed. Acrylic acid was formed with approximately 25% selectivity at 548 K over the impregnated zeolites. The result can be explained by XPS (X-ray photoelectron spectroscopy) measurements, which indicated a good dispersion of the vanadium inside the pores. (author)

Comparison of iodine-123 labelled 2{beta}-carbomethoxy-3{beta}-(4-iodophenyl)tropane and 2{beta}-carbomethoxy-3{beta}-(4-iodophenyl)-N-(3-fluoropropyl)nortropane for imaging of the dopamine transporter in the living human brain

Energy Technology Data Exchange (ETDEWEB)

Kuikka, J.T. [Dept. of Clinical Physiology, Kuopio Univ. Hospital (Finland); Bergstroem, K.A. [Dept. of Clinical Physiology, Kuopio Univ. Hospital (Finland); Ahonen, A. [Dept. of Clinical Chemistry, Oulu Univ. Central Hospital (Finland); Hiltunen, J. [MAP Medical Technologies Oy, Tikkakoski (Finland); Haukka, J. [MAP Medical Technologies Oy, Tikkakoski (Finland); Laensimies, E. [Dept. of Clinical Physiology, Kuopio Univ. Hospital (Finland); Wang Shaoyin [Research Biochemicals International (RBI), Natick, MA (United States); Neumeyer, J.L. [Research Biochemicals International (RBI), Natick, MA (United States)

1995-04-01

Several cocaine congeners are of potential for imaging the dopamine transporter (DAT). Previous studies have shown that iodine-123 labelled 2{beta}-carbomethoxy-3{beta}-(4-iodophenyl)tropane ([{sup 123}I]{beta}-CIT) is a promising radiotracer for imaging the serotonin (5-HT) and dopamine (DA) transporters in the living human brain with single-photon emission tomography (SPET). [{sup 123}I]{beta}-CIT was found to be not very practical for 1-day DAT imaging protocols since peak DAT uptake occurs later than 8 h. Here we report a pilot comparison of [{sup 123}I]{beta}-CIT and 2{beta}-carbomethoxy-3{beta}-(4-iodophenyl)-N-(3-fluoropropyl)nortropane ([{sup 123}I]{beta}-CIT-FP), using SPET imaging in four healthy male subjects. Peak uptake of [{sup 123}I]{beta}-CIT-FP into the basal ganglia occurred earlier (3-4 h after injection of tracer) than that of [{sup 123}I]{beta}-CIT (>8 h). However, the specific DAT binding of [{sup 123}I]{beta}-CIT-FP in the basal ganglia was somewhat less (0.813{+-}0.047) than that of [{sup 123}I]{beta}-CIT (0.922{+-}0.004). Imaging quality is excellent with both tracers and they are potentially of value for brain imaging in various neuropsychiatric disorders. (orig.)

Systematic Risk on Istanbul Stock Exchange: Traditional Beta Coefficient Versus Downside Beta Coefficient

Directory of Open Access Journals (Sweden)

Gülfen TUNA

2013-03-01

Full Text Available The aim of this study is to test the validity of Downside Capital Asset Pricing Model (D-CAPM on the ISE. At the same time, the explanatory power of CAPM's traditional beta and D-CAPM's downside beta on the changes in the average return values are examined comparatively. In this context, the monthly data for seventy three stocks that are continuously traded on the ISE for the period 1991-2009 is used. Regression analysis is applied in this study. The research results have shown that D-CAPM is valid on the ISE. In addition, it is obtained that the power of downside beta coefficient is higher than traditional beta coefficient on explaining the return changes. Therefore, it can be said that the downside beta is superior to traditional beta in the ISE for chosen period.

Integrins beta 5, beta 3 and alpha v are apically distributed in endometrial epithelium.

Science.gov (United States)

Aplin, J D; Spanswick, C; Behzad, F; Kimber, S J; Vićovac, L

1996-07-01

Several adhesion molecules have been shown to occur at the surface of endometrial cells. One of these is the integrin alpha v subunit which associates with various beta chains including beta 5. We demonstrate the presence of integrin beta 5 polypeptide in human endometrial epithelial cells throughout the menstrual cycle using immunocytochemistry with monospecific antibodies, and at the mRNA level by thermal amplification from endometrial cDNA. Integrin beta 5 is also found in a population of bone marrow-derived cells. A notable feature of the distribution of the beta 5 subunit in the glandular and luminal epithelium is its apical localization, which may suggest an involvement in implantation. However, no evidence was found for regulated expression of epithelial beta 5. In mouse, the beta 5 subunit is found at both the apical and basal surface of epithelial cells and expression is essentially oestrous cycle-independent. Comparisons are made in both species with the distribution of the alpha v and beta 3 subunits which also localize to the apical epithelium.

Post-extraction application of beta-tricalcium phosphate in alveolar socket

Directory of Open Access Journals (Sweden)

M. Muñoz-Corcuera

2015-03-01

Full Text Available Aim The objective of this study was to assess the capacity of beta-tricalcium phosphate to facilitate bone formation in the socket and prevent post-extraction alveolar resorption. Materials and methods After premolar extraction in 16 patients, the sockets were filled with beta-tricalcium phosphate. Six months later, during the implant placement surgery, a trephine was used to harvest the bone samples which were processed for histological and histomorphometrical analyses. Data were gathered on patient, clinical, histological and histomorphometric variables at the extraction and implant placement sessions, using data collection forms and pathological reports. Results Clinical outcomes were satisfactory, the biomaterial was radio-opaque on X-ray. Histological study showed: partial filling with alveolar bone of appropriate maturation and mineralization for the healing time, osteoblastic activity and bone lacunae containing osteocytes. The biomaterial was not completely resorbed at six months. Conclusion Beta-tricalcium phosphate is a material capable of achieving preservation of the alveolar bone when it is positioned in the immediate post-extraction socket followed by suture; it also helps the formation of new bone in the socket. Further studies are needed comparing this technique with other available biomaterials, with growth factors and with sites where no alveolar preservation techniques are performed.

Regulation of glycogen synthase kinase-3{beta} (GSK-3{beta}) after ionizing radiation; Regulation der Glykogen Synthase Kinase-3{beta} (GSK-3{beta}) nach ionisierender Strahlung

Energy Technology Data Exchange (ETDEWEB)

Boehme, K.A.

2006-12-15

Glycogen Synthase Kinase-3{beta} (GSK-3{beta}) phosphorylates the Mdm2 protein in the central domain. This phosphorylation is absolutely required for p53 degradation. Ionizing radiation inactivates GSK-3{beta} by phosphorylation at serine 9 and in consequence prevents Mdm2 mediated p53 degradation. During the work for my PhD I identified Akt/PKB as the kinase that phosphorylates GSK-3{beta} at serine 9 after ionizing radiation. Ionizing radiation leads to phosphorylation of Akt/PKB at threonine 308 and serine 473. The PI3 Kinase inhibitor LY294002 completely abolished Akt/PKB serine 473 phosphorylation and prevented the induction of GSK-3{beta} serine 9 phosphorylation after ionizing radiation. Interestingly, the most significant activation of Akt/PKB after ionizing radiation occurred in the nucleus while cytoplasmic Akt/PKB was only weakly activated after radiation. By using siRNA, I showed that Akt1/PKBa, but not Akt2/PKB{beta}, is required for phosphorylation of GSK- 3{beta} at serine 9 after ionizing radiation. Phosphorylation and activation of Akt/PKB after ionizing radiation depends on the DNA dependent protein kinase (DNA-PK), a member of the PI3 Kinase family, that is activated by free DNA ends. Both, in cells from SCID mice and after knockdown of the catalytic subunit of DNA-PK by siRNA in osteosarcoma cells, phosphorylation of Akt/PKB at serine 473 and of GSK-3{beta} at serine 9 was completely abolished. Consistent with the principle that phosphorylation of GSK-3 at serine 9 contributes to p53 stabilization after radiation, the accumulation of p53 in response to ionizing radiation was largely prevented by downregulation of DNA-PK. From these results I conclude, that ionizing radiation induces a signaling cascade that leads to Akt1/PKBa activation mediated by DNA-PK dependent phosphorylation of serine 473. After activation Akt1/PKBa phosphorylates and inhibits GSK-3{beta} in the nucleus. The resulting hypophosphorylated form of Mdm2 protein is no longer

High beta experiments in CHS

International Nuclear Information System (INIS)

Okamura, S.; Matsuoka, K.; Nishimura, K.

1994-09-01

High beta experiments were performed in the low-aspect-ratio helical device CHS with the volume-averaged equilibrium beta up to 2.1 %. These values (highest for helical systems) are obtained for high density plasmas in low magnetic field heated with two tangential neutral beams. Confinement improvement given by means of turning off gas puffing helped significantly to make high betas. Magnetic fluctuations increased with increasing beta, but finally stopped to increase in the beta range > 1 %. The coherent modes appearing in the magnetic hill region showed strong dependence on the beta values. The dynamic poloidal field control was applied to suppress the outward plasma movement with the plasma pressure. Such an operation gave fixed boundary operations of high beta plasmas in helical systems. (author)

Decay Spectroscopy for Nuclear Astrophysics: {beta}-delayed Proton Decay

Energy Technology Data Exchange (ETDEWEB)

Trache, L.; Simmons, E.; Spiridon, A.; McCleskey, M.; Roeder, B. T.; Tribble, R. E. [Texas A and M University, College Station, TX 77845 (United States); Saastamoinen, A.; Jokinen, A.; Aysto, J. [University of Jyvaskyla, Jyvaskyla (Finland); Davinson, T.; Woods, P. J. [University of Edinburgh, Edinburgh (United Kingdom); Pollacco, E.; Kebbiri, M. [CEA/IRFU Saclay (France); Pascovici, G. [IKP, Universitaet zu Koeln (Germany)

2011-11-30

Decay spectroscopy is one of the oldest indirect methods in nuclear astrophysics. We have developed at TAMU techniques to measure beta- and beta-delayed proton decay of sd-shell, proton-rich nuclei. The short-lived radioactive species are produced in-flight, separated, then slowed down (from about 40 MeV/u) and implanted in the middle of very thin Si detectors. These allowed us to measure protons with energies as low as 200 keV from nuclei with lifetimes of 100 ms or less. At the same time we measure gamma-rays up to 8 MeV with high resolution HPGe detectors. We have studied the decay of {sup 23}Al, {sup 27}P, {sup 31}Cl, all important for understanding explosive H-burning in novae. The technique has shown a remarkable selectivity to beta-delayed charged-particle emission and works even at radioactive beam rates of a few pps. The states populated are resonances for the radiative proton capture reactions {sup 22}Na(p,{gamma}){sup 23}Mg(crucial for the depletion of {sup 22}Na in novae), {sup 26m}Al(p,{gamma}){sup 27}Si and {sup 30}P(p,{gamma}){sup 31}S(bottleneck in novae and XRB burning), respectively. More recently we have radically improved the technique using a gas based detector we call AstroBox.

20F beta spectrum shape and weak interaction tests

Science.gov (United States)

Voytas, Paul; George, Elizabeth; Chuna, Thomas; Naviliat-Cuncic, Oscar; Hughes, Max; Huyan, Xueying; Minamisono, Kei; Paulauskas, Stanley

2016-09-01

Precision measurements of the shape of beta spectra can test our understanding of the weak interaction. We are carrying out a measurement of the shape of the energy spectrum of β particles from 20F decay. The primary motivation is to test the so-called strong form of the conserved vector current (CVC) hypothesis. The measurement should also enable us to place competitive limits on the contributions of exotic tensor couplings in beta decay. We aim to achieve a relative precision better than 3% on the linear contribution to the shape. This represents an order of magnitude improvement compared to previous experiments in 20F. In order to control systematic effects, we are using a technique that takes advantage of high energy radioactive beams at the NSCL to implant the decaying nuclei in scintillation detectors deeply enough that the emitted beta particles cannot escape. The β-particle energy is measured with the implantation detector after switching off the implantation beam. Ancillary detectors are used to identify the 1.633-MeV γ-rays following the 20F β decay for coincidence measurements in order to tag the transition of interest and to reduce backgrounds. We report on the status of the analysis. Supported in part with Awards from the NSCL PAC and the National Science Foundation under Grant No. PHY-1506084.

Conformation, molecular packing and field effect mobility of regioregular beta,beta'-dihexylsexithiophiophene

DEFF Research Database (Denmark)

Kiriy, N.; Kiriy, A.; Bocharova, V.

2004-01-01

by the pulse-radiolysis time-resolved microwave conductivity (PR-TRMC) technique was found to be Sigmamu(min) = 3.9 x 10(-3) cm(2) V-1 s(-1), which is comparable with the PR-TRMC mobility found for alpha,omega-DH6T. The field-effect mobility (FEM) of beta,beta'-DH6T was found to be on the order of 10(-5) cm(2......) V-1 s(-1), which is considerably less than the FEM of alpha,omega-DH6T. To understand the reason for such poor macroscopic electrical properties, the conformation and the molecular packing of beta,beta'-DH6T were systematically studied by means of UV-vis spectroscopy, scanning electron microscopy...... less dense crystalline packing than alpha,omega-DH6T. In contrast to the almost upright orientation of alpha,omega-DH6T molecules against the substrate (tilt angle about 68), the long axis of beta,beta'-DH6T molecules and the surface plane form an angle of similar to20degrees. Thus, the crystalline...

Levered and unlevered Beta

OpenAIRE

Fernandez, Pablo

2003-01-01

We prove that in a world without leverage cost the relationship between the levered beta ( L) and the unlevered beta ( u) is the No-costs-of-leverage formula: L = u + ( u - d) D (1 - T) / E. We also analyze 6 alternative valuation theories proposed in the literature to estimate the relationship between the levered beta and the unlevered beta (Harris and Pringle (1985), Modigliani and Miller (1963), Damodaran (1994), Myers (1974), Miles and Ezzell (1980), and practitioners) and prove that all ...

Boosted beta regression.

Directory of Open Access Journals (Sweden)

Matthias Schmid

Full Text Available Regression analysis with a bounded outcome is a common problem in applied statistics. Typical examples include regression models for percentage outcomes and the analysis of ratings that are measured on a bounded scale. In this paper, we consider beta regression, which is a generalization of logit models to situations where the response is continuous on the interval (0,1. Consequently, beta regression is a convenient tool for analyzing percentage responses. The classical approach to fit a beta regression model is to use maximum likelihood estimation with subsequent AIC-based variable selection. As an alternative to this established - yet unstable - approach, we propose a new estimation technique called boosted beta regression. With boosted beta regression estimation and variable selection can be carried out simultaneously in a highly efficient way. Additionally, both the mean and the variance of a percentage response can be modeled using flexible nonlinear covariate effects. As a consequence, the new method accounts for common problems such as overdispersion and non-binomial variance structures.

Recent technologic developments on high-resolution beta imaging systems for quantitative autoradiography and double labeling applications

CERN Document Server

Barthe, N; Chatti, K; Coulon, P; Maitrejean, S; 10.1016/j.nima.2004.03.014

2004-01-01

Two novel beta imaging systems, particularly interesting in the field of radiopharmacology and molecular biology research, were developed these last years. (1) a beta imager was derived from research conducted by Pr Charpak at CERN. This parallel plate avalanche chamber is a direct detection system of beta radioactivity, which is particularly adapted for qualitative and quantitative autoradiography. With this detector, autoradiographic techniques can be performed with emitters such as /sup 99m/Tc because this radionuclide emits many low-energy electrons and the detector has a very low sensitivity to low-range gamma -rays. Its sensitivity (smallest activity detected: 0.007 cpm/mm/sup 2/ for /sup 3/H and 0.01 for /sup 14/C), linearity (over a dynamic range of 10/sup 4/) and spatial resolution (50 mu m for /sup 3/H or /sup 99m/Tc to 150 mu m for /sup 32/P or /sup 18/F ( beta /sup +/)) gives a real interest to this system as a new imaging device. Its principle of detection is based on the analysis of light emitte...

Regulation of beta cell replication

DEFF Research Database (Denmark)

Lee, Ying C; Nielsen, Jens Høiriis

2008-01-01

Beta cell mass, at any given time, is governed by cell differentiation, neogenesis, increased or decreased cell size (cell hypertrophy or atrophy), cell death (apoptosis), and beta cell proliferation. Nutrients, hormones and growth factors coupled with their signalling intermediates have been...... suggested to play a role in beta cell mass regulation. In addition, genetic mouse model studies have indicated that cyclins and cyclin-dependent kinases that determine cell cycle progression are involved in beta cell replication, and more recently, menin in association with cyclin-dependent kinase...... inhibitors has been demonstrated to be important in beta cell growth. In this review, we consider and highlight some aspects of cell cycle regulation in relation to beta cell replication. The role of cell cycle regulation in beta cell replication is mostly from studies in rodent models, but whether...

Complement activation by the amyloid proteins A beta peptide and beta 2-microglobulin

DEFF Research Database (Denmark)

Nybo, Mads; Nielsen, E H; Svehag, S E

1999-01-01

component nor heparan sulfate did significantly alter the A beta-induced CA. The results indicate that not only fibrillar A beta but also oligomers of, in particular, beta 2M from patients with dialysis-associated amyloidosis are capable of inducing CA at supra-physiological concentrations....

Effects of prenatal exposure to low-dose {beta} radiation from tritiated water on the neutrobehavior of mice

Energy Technology Data Exchange (ETDEWEB)

Wang Bing [Tokyo Univ. (Japan). Faculty of Science; Zhou Xiangyan

1995-06-01

Pregnant adult C57BL/6J mice, randomly assigned to 1 of 4 groups, 3 of them were irradiated with {beta}-rays from tritiated water (HTO) by a single intraperitoneal injection on the 12.5th day of gestation. Their offspring received cumulative doses of 0, 5, 10 or 30 cGy in utero. Male pups were trained and examined using a set of behavioral tests that included avoidance acquisition and avoidance maintenance, open field test, hole-board dipping, a water maze, and a food labyrinth. Results were found for most parameters in the 10 and 30 cGy groups that differed significantly from results for the controls, indicating that the behavioral teratogenic effect of prenatal exposure to chronic {beta}-ray radiation from HTO may be greater than the same dose of acute X- or {gamma}-irradiation and that 10 cGy may be the lowest detectable dose level at which behavioral changes is detectable under the conditions used in this experiment. (author) 56 refs.

Enhancement of wear and corrosion resistance of beta titanium alloy by laser gas alloying with nitrogen

Science.gov (United States)

Chan, Chi-Wai; Lee, Seunghwan; Smith, Graham; Sarri, Gianluca; Ng, Chi-Ho; Sharba, Ahmed; Man, Hau-Chung

2016-03-01

The relatively high elastic modulus coupled with the presence of toxic vanadium (V) in Ti6Al4V alloy has long been a concern in orthopaedic applications. To solve the problem, a variety of non-toxic and low modulus beta-titanium (beta-Ti) alloys have been developed. Among the beta-Ti alloy family, the quaternary Ti-Nb-Zr-Ta (TNZT) alloys have received the highest attention as a promising replacement for Ti6Al4V due to their lower elastic modulus and outstanding long term stability against corrosion in biological environments. However, the inferior wear resistance of TNZT is still a problem that must be resolved before commercialising in the orthopaedic market. In this work, a newly developed laser surface treatment technique was employed to improve the surface properties of Ti-35.3Nb-7.3Zr-5.7Ta alloy. The surface structure and composition of the laser-treated TNZT surface were examined by grazing incidence X-ray diffraction (GI-XRD) and X-ray photoelectron spectroscopy (XPS). The wear and corrosion resistance were evaluated by pin-on-plate sliding test and anodic polarisation test in Hanks' solution. The experimental results were compared with the untreated (or base) TNZT material. The research findings showed that the laser surface treatment technique reported in this work can effectively improve the wear and corrosion resistance of TNZT.

Improved limits on beta(-) and beta(-) decays of Ca-48

Czech Academy of Sciences Publication Activity Database

Bakalyarov, A.; Balysh, A.; Barabash, AS.; Beneš, P.; Briancon, C.; Brudanin, V. B.; Čermák, P.; Egorov, V.; Hubert, F.; Hubert, P.; Korolev, NA.; Kosjakov, VN.; Kovalík, Alojz; Lebedev, NA.; Novgorodov, A. F.; Rukhadze, NI.; Štekl, NI.; Timkin, VV.; Veleshko, IE.; Vylov, T.; Umatov, VI.

2002-01-01

Roč. 76, č. 9 (2002), s. 545-547 ISSN 0021-3640 Institutional research plan: CEZ:AV0Z1048901 Keywords : beta decay * double beta decay * Ca-48 Subject RIV: BG - Nuclear, Atomic and Molecular Physics, Colliders Impact factor: 1.483, year: 2002

Adrenocorticotropin, beta-endorphin, and beta-lipotropin in normal thyroid and lung: possible implications for ectopic hormone secretion.

Science.gov (United States)

Clements, J A; Funder, J W; Tracy, K; Morgan, F J; Campbell, D J; Lewis, P; Hearn, M T

1982-12-01

The expression of the proopiomelanocortin (POMC) gene by normal lung and thyroid was examined by measurement of the content of ACTH, beta-lipotropin (beta LPH), and beta-endorphin (beta EP) in porcine lung and thyroid tissue. Acid extracts of normal porcine lung and thyroid tissue each contained appreciable amounts of immunoreactive (ir) ACTH, ir-beta LPH, and ir-beta EP. The content of ir-beta LPH in both tissues exceeded by severalfold, on a molar basis, the content of ir-ACTH and ir-beta EP, suggesting that the common precursor POMC was processed predominantly to peptides other than ir-ACTH and ir-beta EP. A porcine thyroid extract (Calcitare, porcine calcitonin, Armour) showed equivalent levels of beta EP-like immunoreactivity and bioactivity, measured by opiate radioreceptor assay; in contrast, ACTH-like bioactivity, measured by rat zona fasciculata steroidogenesis, was only 4% of ACTH-like immunoreactivity. On reversed phase high performance liquid chromatography, Calcitare showed multiple peaks of ACTH-like immunoreactivity, one of which coeluted with porcine ACTH-(1-39), and two much smaller peaks of beta EP-like immunoreactivity, of which the smaller coeluted with porcine beta EP. These data suggest that both lung and thyroid gland synthesize POMC, which in normal tissue is usually predominantly processed to species other than ACTH and beta EP. Ectopic secretion of ACTH and beta EP by lung and thyroid neoplasms may thus represent the loss of a system(s) normally responsible for processing the precursor beyond ACTH and beta EP.

Silencing of beta-carotene hydroxylase increases total carotenoid and beta-carotene levels in potato tubers

Directory of Open Access Journals (Sweden)

Pizzichini Daniele

2007-03-01

Full Text Available Abstract Background Beta-carotene is the main dietary precursor of vitamin A. Potato tubers contain low levels of carotenoids, composed mainly of the xanthophylls lutein (in the beta-epsilon branch and violaxanthin (in the beta-beta branch. None of these carotenoids have provitamin A activity. We have previously shown that tuber-specific silencing of the first step in the epsilon-beta branch, LCY-e, redirects metabolic flux towards beta-beta carotenoids, increases total carotenoids up to 2.5-fold and beta-carotene up to 14-fold. Results In this work, we silenced the non-heme beta-carotene hydroxylases CHY1 and CHY2 in the tuber. Real Time RT-PCR measurements confirmed the tuber-specific silencing of both genes . CHY silenced tubers showed more dramatic changes in carotenoid content than LCY-e silenced tubers, with beta-carotene increasing up to 38-fold and total carotenoids up to 4.5-fold. These changes were accompanied by a decrease in the immediate product of beta-carotene hydroxylation, zeaxanthin, but not of the downstream xanthophylls, viola- and neoxanthin. Changes in endogenous gene expression were extensive and partially overlapping with those of LCY-e silenced tubers: CrtISO, LCY-b and ZEP were induced in both cases, indicating that they may respond to the balance between individual carotenoid species. Conclusion Together with epsilon-cyclization of lycopene, beta-carotene hydroxylation is another regulatory step in potato tuber carotenogenesis. The data are consistent with a prevalent role of CHY2, which is highly expressed in tubers, in the control of this step. Combination of different engineering strategies holds good promise for the manipulation of tuber carotenoid content.

Improving the resolution of beta scattering spectroscopy

International Nuclear Information System (INIS)

Celiktas, C.; Selvi, S.; Yegin, G.

2004-01-01

We have examined the performance of a modified beta-ray spectrometer using a pulse shape analyzer/timing single channel analyzer and related electronics, thereby preserving the low energy electron tail in measurement of the scattered electron spectra from an n-type Si wafer target. Comparison of measurements with the scattering spectra calculated by the Monte Carlo program EGS4 indicates good agreement across a significant part of the spectrum, an exception being for the energy region 30-100 keV. Re-evaluation of existing scattering cross-sections would be useful, as would possible geometrical effects of the scattering arrangement used herein. Present efforts seek to contribute to the evaluation of electron scattering cross-sections and improvement in theoretical models

Effect of gamma-irradiation on the levels of total and cis/trans isomers of beta-carotene in dehydrated parsley

Energy Technology Data Exchange (ETDEWEB)

Sebastiao, K.I. E-mail: kisebas@net.ipen.br; Almeida-Muradian, L.B. E-mail: ligiabi@usp.br; Romanelli, Maria Fernanda; Koseki, Paula Massae; Villavicencio, A.L.C.H. E-mail: villavic@net.ipen.br

2002-03-01

Ionizing radiation is a method for preservation of foods that use the high energy of gamma rays or accelerated electrons, thereby ionizing molecules. The most important precursor of vitamin A is {beta}-carotene, a carotenoid with pro-vitamin A activity. The highly unsaturated chain confers the instability of {beta}-carotene, and some reactions, as isomerisation, can reduce the characteristics of pro-vitamin A. The present study investigated whether increasing doses of 0, 10 and 20 kGy lower the total {beta}-carotene level and if an enhancement of cis-isomers occurred on samples of dehydrated parsley. No differences were observed of either fractions analyzed at doses applied in this study, nor did it contribute to the decrease of vitamin A.

Determinants of RNA polymerase alpha subunit for interaction with beta, beta', and sigma subunits: hydroxyl-radical protein footprinting.

OpenAIRE

Heyduk, T; Heyduk, E; Severinov, K; Tang, H; Ebright, R H

1996-01-01

Escherichia coli RNA polymerase (RNAP) alpha subunit serves as the initiator for RNAP assembly, which proceeds according to the pathway 2 alpha-->alpha 2-->alpha 2 beta-->alpha 2 beta beta'-->alpha 2 beta beta' sigma. In this work, we have used hydroxyl-radical protein footprinting to define determinants of alpha for interaction with beta, beta', and sigma. Our results indicate that amino acids 30-75 of alpha are protected from hydroxyl-radical-mediated proteolysis upon interaction with beta ...

{beta} - amyloid imaging probes

Energy Technology Data Exchange (ETDEWEB)

Jeong, Jae Min [Seoul National University College of Medicine, Seoul (Korea, Republic of)

2007-04-15

Imaging distribution of {beta} - amyloid plaques in Alzheimer's disease is very important for early and accurate diagnosis. Early trial of the {beta} -amyloid plaques includes using radiolabeled peptides which can be only applied for peripheral {beta} - amyloid plaques due to limited penetration through the blood brain barrier (BBB). Congo red or Chrysamine G derivatives were labeled with Tc-99m for imaging {beta} - amyloid plaques of Alzheimer patient's brain without success due to problem with BBB penetration. Thioflavin T derivatives gave breakthrough for {beta} - amyloid imaging in vivo, and a benzothiazole derivative [C-11]6-OH-BTA-1 brought a great success. Many other benzothiazole, benzoxazole, benzofuran, imidazopyridine, and styrylbenzene derivatives have been labeled with F-18 and I-123 to improve the imaging quality. However, [C-11]6-OH-BTA-1 still remains as the best. However, short half-life of C-11 is a limitation of wide distribution of this agent. So, it is still required to develop an Tc-99m, F-18 or I-123 labeled agent for {beta} - amyloid imaging agent.

Isotope Effects in the Bonds of beta-CrOOH and beta-CrOOD

DEFF Research Database (Denmark)

Nørlund Christensen, A.; Hansen, P.; Lehmann, M. S.

1976-01-01

Samples of orthorhombic chromium oxide hydroxide, beta -CrOOH, and the deuterated compound, beta -CrOOD, were prepared hydrothermally. The crystal structures were determined by powder profile refinement technique using neutron diffraction data. Unit cells are: beta -CrOOH: a equals 4. 862(2) A, b...... equals 4. 298(a) A, c equals 2. 995(1) A; beta -CrOOD: a equals 4. 873(5) A, b equals 4. 332(7) A, c equals 2. 963(2) A, with Z equals 2. The space group is P2//1nm or Pnnm....

Noninvasive analysis of skin iron and zinc levels in beta-thalassemia major and intermedia

International Nuclear Information System (INIS)

Gorodetsky, R.; Goldfarb, A.; Dagan, I.; Rachmilewitz, E.A.

1985-01-01

Diagnostic x-ray spectrometry, a method based on x-ray fluorescence analysis, was used for noninvasive determination of iron and zinc in two distinct skin areas, representing predominantly dermal and epidermal tissues, in 56 patients with beta-thalassemia major and intermedia. The mean iron levels in the skin of patients with beta-thalassemia major and intermedia were elevated by greater than 200% and greater than 50%, respectively, compared with control values. The zinc levels of both skin areas examined were within the normal range. The data indicate that the rate and number of blood transfusions, which correlated well with serum ferritin levels (r . 0.8), are not the only factors that determine the amount of iron deposition in the skin (r less than 0.6). Other sources of iron intake contribute to the total iron load in the tissues, particularly in patients who are not given multiple transfusions. The noninvasive quantitation of skin levels may reflect the extent of iron deposition in major parenchymal organs. Repeated DXS examinations of the skin could monitor the clearance of iron from the tissues of patients with iron overload in the course of therapy with chelating agents

Antibodies against chromosomal beta-lactamase

DEFF Research Database (Denmark)

Giwercman, B; Rasmussen, J W; Ciofu, Oana

1994-01-01

A murine monoclonal anti-chromosomal beta-lactamase antibody was developed and an immunoblotting technique was used to study the presence of serum and sputum antibodies against Pseudomonas aeruginosa chromosomal group 1 beta-lactamase in patients with cystic fibrosis (CF). The serum antibody...... 1 cephalosporinase. We found a wide range of chromosomal beta-lactamase activity in the sputum samples, with no correlation with basal or induced activity of beta-lactamase expression. The presence of anti-beta-lactamase antibodies in endobronchial sputum could be an important factor in the defense...

Repair of soft X-ray damage to mammalian cell DNA

Energy Technology Data Exchange (ETDEWEB)

Meldrum, R.A.; Wharton, C.W. (Birmingham Univ. (UK). Dept. of Biochemistry)

1990-10-01

Inhibitors of polymerase {alpha} (hydroxyurea and cytosine arabinoside) and an inhibitor of polymerase {beta} and ''delta (di-deoxythymidine) had equal inhibitory effects on repair synthesis in the first 15 min after irradiation of Chinese hamster ovary cells with soft x-rays produced from a laser plasma. Polymerase {alpha} inhibitors had considerably more effect after 15 min following irradiation. This implies that polymerase {alpha}, {beta}, and/or {delta} are all equally active in the initial stages of repair synthesis after soft X-radiation, but {alpha}-activity is more prominent in later stages of repair synthesis. Polymerase {alpha} is thought to catalyse long-patch repair synthesis, while polymerase {beta} is thought to catalyse short-patch repair. Polymerase {delta} has been shown to be active in DNA repair synthesis, but its precise function is as yet uncertain. (author).

Metalo-beta-lactamases Metallo-beta-lactamases

Directory of Open Access Journals (Sweden)

Rodrigo Elisandro Mendes

2006-04-01

Full Text Available Nos últimos anos tem sido observada maior incidência de bacilos Gram-negativos resistentes a cefalosporinas de espectro ampliado no ambiente hospitalar, ocasionando, assim, maior uso de betalactâmicos mais potentes, como os carbapenens. A utilização de carbapenens exerce maior pressão seletiva sobre a microbiota hospitalar, o que pode ocasionar aumento da resistência a esses agentes. Entre os mecanismos de resistência a carbapenens mais comumente identificados estão a produção de betalactamases, como, por exemplo, as pertencentes à classe D de Ambler e as que pertencem à classe B de Ambler, ou metalo-beta-lactamases (MbetaL. Essas últimas hidrolisam todos betalactâmicos comercialmente disponíveis, sendo a única exceção o monobactam aztreonam. Desde o início da década de 1990, novos genes que codificam MbetaLs têm sido descritos em microrganismos clinicamente importantes, como Pseudomonas spp., Acinetobacter spp. e membros da família Enterobacteriaceae. O encontro desses microrganismos não-sensíveis a carbapenens pode ser submetido a metodologias fenotípicas para detecção da produção de MbetaL com o intuito de auxiliar a Comissão de Controle de Infecção Hospitalar (CCIH e prevenir a disseminação desses determinantes de resistência, uma vez que genes que codificam MbetaLs estão contidos em estruturas genéticas que propiciam sua mobilidade de forma muito efetiva, sendo então facilmente disseminados.Increase isolation of Gram-negative bacilli resistant to broad-spectrum cephalosporin has been observed during the last few years, thus determining the use of more potent beta-lactams, such as carbapenems. The use of these antimicrobial agents may lead to the emergence of carbapenem resistant Gram-negative bacilli in the nosocomial environment. Carbapenem resistance may be due to the production of Ambler class D beta-lactamase or Ambler class B beta-lactamase, also called metallo-beta-lactamase (MbetaL. Apart from

Beta limits for ETF

International Nuclear Information System (INIS)

Helton, F.J.; Miller, R.L.

1982-01-01

ETF (Engineering Test Facility) one-dimensional transport simulations indicate that a volume-average beta of 4% is required for ignition. It is therefore important that theoretical beta limits, determined by requiring equilibria to be stable to all ideal modes, exceed 4%. This paper documents an ideal MHD analysis wherein it is shown that, with appropriate plasma cross-sectional shape and current profile optimization, operation near 5% is possible. The critical beta value, however, depends on the functional form used for ff', which suggests that higher critical betas could be achieved by directly optimizing the safety factor profile. (author)

Derivatives of the Incomplete Beta Function

Directory of Open Access Journals (Sweden)

Robert J. Boik

1998-03-01

Full Text Available The incomplete beta function is defined as where Beta(p, q is the beta function. Dutka (1981 gave a history of the development and numerical evaluation of this function. In this article, an algorithm for computing first and second derivatives of Ix,p,q with respect to p and q is described. The algorithm is useful, for example, when fitting parameters to a censored beta, truncated beta, or a truncated beta-binomial model.

BetaShape: A new code for improved analytical calculations of beta spectra

Directory of Open Access Journals (Sweden)

Mougeot Xavier

2017-01-01

Full Text Available The new code BetaShape has been developed in order to improve the nuclear data related to beta decays. An analytical model was considered, except for the relativistic electron wave functions, for ensuring fast calculations. Output quantities are mean energies, log ft values and beta and neutrino spectra for single and multiple transitions. The uncertainties from the input parameters, read from an ENSDF file, are propagated. A database of experimental shape factors is included. A comparison over the entire ENSDF database with the standard code currently used in nuclear data evaluations shows consistent results for the vast majority of the transitions and highlights the improvements that can be expected with the use of BetaShape.

Preventive Effects of Beta-Hydroxy-Beta-Methyl Butyrate

OpenAIRE

N. Ravanbakhsh; N. Torabi; M. Foadoddini

2016-01-01

Aims: One of the major factors in sudden cardiac arrest is the initiation and continuation of deadly arrhythmias during ischemia. It is known that beta-hydroxy-beta-methylbutyrate (HMB) has useful effects such as anti-inflammatory and anti-apoptosis effects in the skeletal muscles. The aim of this study was to investigate the preventive effects of HMB on the ventricular arrhythmias due to the ischemia. Materials & Methods: In the experimental study, 30 Wistar male rats were randomly div...

Beta-thalassemia

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Origa Raffaella

2010-05-01

Full Text Available Abstract Beta-thalassemias are a group of hereditary blood disorders characterized by anomalies in the synthesis of the beta chains of hemoglobin resulting in variable phenotypes ranging from severe anemia to clinically asymptomatic individuals. The total annual incidence of symptomatic individuals is estimated at 1 in 100,000 throughout the world and 1 in 10,000 people in the European Union. Three main forms have been described: thalassemia major, thalassemia intermedia and thalassemia minor. Individuals with thalassemia major usually present within the first two years of life with severe anemia, requiring regular red blood cell (RBC transfusions. Findings in untreated or poorly transfused individuals with thalassemia major, as seen in some developing countries, are growth retardation, pallor, jaundice, poor musculature, hepatosplenomegaly, leg ulcers, development of masses from extramedullary hematopoiesis, and skeletal changes that result from expansion of the bone marrow. Regular transfusion therapy leads to iron overload-related complications including endocrine complication (growth retardation, failure of sexual maturation, diabetes mellitus, and insufficiency of the parathyroid, thyroid, pituitary, and less commonly, adrenal glands, dilated myocardiopathy, liver fibrosis and cirrhosis. Patients with thalassemia intermedia present later in life with moderate anemia and do not require regular transfusions. Main clinical features in these patients are hypertrophy of erythroid marrow with medullary and extramedullary hematopoiesis and its complications (osteoporosis, masses of erythropoietic tissue that primarily affect the spleen, liver, lymph nodes, chest and spine, and bone deformities and typical facial changes, gallstones, painful leg ulcers and increased predisposition to thrombosis. Thalassemia minor is clinically asymptomatic but some subjects may have moderate anemia. Beta-thalassemias are caused by point mutations or, more rarely

17Beta-hydroxysteroid dehydrogenase (17beta-HSD) in scleractinian corals and zooxanthellae.

Science.gov (United States)

Blomquist, Charles H; Lima, P H; Tarrant, A M; Atkinson, M J; Atkinson, S

2006-04-01

Steroid metabolism studies have yielded evidence of 17beta-hydroxysteroid dehydrogenase (17beta-HSD) activity in corals. This project was undertaken to clarify whether there are multiple isoforms of 17beta-HSD, whether activity levels vary seasonally, and if zooxanthellae contribute to activity. 17Beta-HSD activity was characterized in zooxanthellate and azooxanthellate coral fragments collected in summer and winter and in zooxanthellae cultured from Montipora capitata. More specifically, 17beta-HSD activity was characterized with regard to steroid substrate and inhibitor specificity, coenzyme specificity, and Michaelis constants for estradiol (E2) and NADP+. Six samples each of M. capitata and Tubastrea coccinea (three summers, three winters) were assayed with E2 and NADP+. Specific activity levels (pmol/mg protein) varied 10-fold among M. capitata samples and 6-fold among T. coccinea samples. There was overlap of activity levels between summer and winter samples. NADP+/NAD+ activity ratios varied from 1.6 to 22.2 for M. capatita, 2.3 to 3.8 for T. coccinea and 0.7 to 1.1 for zooxanthellae. Coumestrol was the most inhibitory of the steroids and phytoestrogens tested. Our data confirm that corals and zooxanthellae contain 17beta-HSD and are consistent with the presence of more than one isoform of the enzyme.

Synthesis and characterization of beta-Ga2O3 nanorod array clumps by chemical vapor deposition.

Science.gov (United States)

Shi, Feng; Wei, Xiaofeng

2012-11-01

beta-Ga2O3 nanorod array clumps were successfully synthesized on Si (111) substrates by chemical vapor deposition. The composition, microstructure, morphology, and light-emitting property of these clumps were characterized by X-ray diffraction, Fourier transform infrared spectrophotometry, X-ray photoelectron spectroscopy, scanning electron microscopy, high-resolution transmission electron microscopy, Raman spectroscopy, and photoluminescence. The results demonstrate that the sample synthesized at 1050 degrees C for 15 min was composed of monoclinic beta-Ga2O3 nanorod array clumps, where each single nanorod was about 300 nm in diameter with some nano-droplets on its tip. These results reveal that the growth mechanism agrees with the vapor-liquid-solid (VLS) process. The photoluminescence spectrum shows that the Ga2O3 nanorods have a blue emission at 438 nm, which may be attributed to defects, such as oxygen vacancies and gallium-oxygen vacancy pairs. Defect-energy aggregation confinement growth theory was proposed to explain the growth mechanism of Ga2O3 nanorod array clumps collaborated with the VLS mechanism.

Energy response of an imaging plate exposed to standard beta sources

International Nuclear Information System (INIS)

Gonzalez, A.L.; Li, H.; Mitch, M.; Tolk, N.; Duggan, D.M.

2002-01-01

Imaging plates (IPs) are a reusable media, which when exposed to ionizing radiation, store a latent image that can be read out with a red laser as photostimulated luminescence (PSL). They are widely used as a substitute for X-ray films for diagnostic studies. In diagnostic radiology this technology is known as computed radiography. In this work, the energy response of a commercial IP to beta-particle reference radiation fields used for calibrations at the National Institute of Standards and Technology was investigated. The absorbed dose in the active storage phosphor layer was calculated following the scaling procedure for depth dose for high Z materials with reference to water. It was found that the beta particles from Pm-147 and Kr-85 gave 68% and 24% higher PSL responses than that induced by Sr-90, respectively, which was caused by the different PSL detection efficiencies. In addition, normalized response curves of the IPs as a function of depth in polystyrene were measured and compared with the data measured using extrapolation chamber techniques. The difference between both sets of data resulted from the continuous energy change as the beta particle travels across the material, which leads to a different PSL response

Skin dose assessment in routine personnel beta/gamma dosimetry

International Nuclear Information System (INIS)

Christensen, P.

1980-01-01

The International Commission on Radiological Protection (Publication 26) has recommended a tissue depth of 5 to 10 mg.cm -2 for skin dose assessments. This requirement is generally not fulfilled by routine monitoring procedures because of practical difficulties in using very thin dosemeters with low sensitivity and therefore a high minimum detectable dose. Especially for low-energy beta-ray exposures underestimations of the skin dose by a factor of more than ten may occur. Low-transparent graphite-mixed sintered LiF and Li 2 B 4 0 7 : Mn dosemeters were produced which show a skin-equivalent response to beta and gamma exposures over a wide range of energies. These have found wide-spread application for extremity dosimetry but have not yet been generally introduced in routine personnel beta/gamma monitoring. The following adaptations of existing routine monitoring systems for improved skin dose assessments have been investigated: 1) Placement of a supplementary, thin, skin-dose equivalent dosemeter in the TLD badge to give additional information on low-energy exposures. 2) Introduction of a second photomultiplier in the read-out chamber which enables a simultaneous determination of emitted TL from both sides of the dosemeter separately. This method makes use of the selfshielding of the dosemeter to give information on the low-energy dose contribution. 3) By diffusion of Li 2 B 4 0 7 into solid LiF-dosemeters it was possible to produce a surface layer with a new distinct glow-peak at about 340 deg C which is not present in the undiffused part of the LiF chip, and which can be utilized for the assessment of the skin-dose. Data on energy response and accuracy of dose measurement for beta/gamma exposures are given for the three methods and advantages and disadvantages are discussed (H.K.)

Human APC sequesters beta-catenin even in the absence of GSK-3beta in a Drosophila model.

Science.gov (United States)

Rao, P R; Makhijani, K; Shashidhara, L S

2008-04-10

There have been conflicting reports on the requirement of GSK-3beta-mediated phosphorylation of the tumor suppressor adenomatous polyposis coli (APC) vis-à-vis its ability to bind and degrade beta-catenin. Using a unique combination of loss of function for Shaggy/GSK-3beta and a gain of function for human APC in Drosophila, we show that misexpressed human APC (hAPC) can still sequester Armadillo/beta-catenin. In addition, human APC could suppress gain of Wnt/Wingless phenotypes associated with loss of Shaggy/GSK-3beta activity, suggesting that sequestered Armadillo/beta-catenin is non-functional. Based on these studies, we propose that binding per se of beta-catenin by APC does not require phosphorylation by GSK-3beta.

Genetics Home Reference: beta thalassemia

Science.gov (United States)

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

The effects of beta-carotene and vitamin E on erythrocytes lipid peroxidation in beta-thalassemia patients

Directory of Open Access Journals (Sweden)

Soleiman Mahjoub

2007-12-01

Full Text Available BACKGROUND: Thalassemia is the most common hereditary disease in the world. Thalassemic erythrocytes are exposed to higher oxidative stress and lipid peroxidation. The aim of this study was to investigate the effects of beta-carotene and vitamin E on erythrocytes lipid peroxidation in beta-thalassemia patients.
METHODS: A prospective double-blind, placebo-controlled study of the effect of beta-carotene and vitamin E on lipid peroxidation in erythrocytes membranes was performed on 120 beta-thalassemia major patients in four groups. The patients were supplemented for 4 weeks as follows: group 1 with beta-carotene (13 mg/day, group 2 with vitamin E (550 mg/day, group 3 with beta-carotene plus vitamin E and group 4 with placebo. We prepared all capsules for 4 roups in the same shape and color. Measurements of serum beta-carotene and vitamin E were performed by high performance
liquid chromatography. After preparation of ghost cells from blood specimens, malondialdehyde (MDA was determined as index of lipid peroxidation in erythrocytes membranes before and after treatment. RESULTS: The levels of serum beta-carotene and vitamin E were significantly lower and MDA concentrations in erythrocytes membranes were significantly higher in beta-thalassemia patients compared to controls (P<0.001. In groups that treated with vitamin supplements for 4-weeks, lipid peroxidation rates were significantly reduced after treatment (P<0.001, but in placebo group there was not significant difference (P>0.05.
CONCLUSIONS: Our findings provide evidence that an oral treatment with beta-carotene and vitamin E can significantly reduce lipid peroxidation of erythrocytes membranes and could be useful in management of beta-thalassemia major patients. KEYWORDS: Beta-thalassemia major, beta-carotene, vitamin E, malondialdehyde, lipid peroxidation.

A new tactic for Triatoma infestans control: fabrics impregnated with beta-cypermethrin Telas impregnadas de beta-cipermetrina: una nueva táctica para el control de Triatoma infestans

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Edgardo Wood

1999-07-01

alternativo que podría ser un complemento práctico y barato de las medidas de control convencionales sería el empleo de telas impregnadas de piretroides. Los insectos que intentaran penetrar la tela o caminaran sobre ella en busca de comida serían intoxicados por la exposición al piretroide absorbido. En este estudio se utilizó un concentrado emulsionado del piretroide beta-cipermetrina [alfa-ciano-3-fenoxibencil-3- (2,2-diclorovinil -2,2-dimetil-ciclopropano-carboxilato] para impregnar diferentes telas y después se investigó su eficacia y persistencia para matar a Triatoma infestans. Los bioensayos de laboratorio revelaron que, con una dosis de beta-cipermetrina de 0,2 g/m², el efecto insecticida era más duradero en la lana que en el algodón o el rayón. Ocho meses después de la impregnación, se registró una eficacia residual de 100% en la lana, de 80% en las telas de rayón y algodón y de 50% en las de rayón y poliéster. Además, las telas impregnadas de beta-cipermetrina presentaron mayor efecto repelente que las impregnadas de deltametrina o cipermetrina.En los estudios de campo, después de ser impregnadas in situ con una dosis de beta-cipermetrina de 1 g/m² y secadas, las telas fueron colocadas en el interior de las casas, debajo de los colchones o clavadas al techo. Estos estudios de campo demostraron que el método era muy eficaz para mantener los domicilios sin triatómidos durante al menos un año y que tenía un alto grado de aceptación por parte de los moradores.

Autoclave and beta-amylolysis lead to reduced in vitro digestibility of starch.

Science.gov (United States)

Hickman, B Elliot; Janaswamy, Srinivas; Yao, Yuan

2009-08-12

In this study, a combination of autoclave and beta-amylolysis was used to modulate the digestibility of normal corn starch (NCS) and wheat starch (WS). The modification procedure comprised three cycles of autoclave at 35% moisture content and 121 degrees C, beta-amylolysis, and one additional cycle of autoclave. Starch materials were sampled at each stage and characterized. The fine structure of starch was determined using high-performance size-exclusion chromatography, the micromorphology of starch dispersion was imaged using cryo-SEM, the crystalline pattern was evaluated using wide-angle X-ray powder diffraction, and the digestibility was measured using Englyst assay. After beta-amylolysis, amylose was enriched (from 25.4 to 33.2% for NCS and from 27.5 to 32.8% for WS) and the branch density was increased (from 5.2 to 7.7% for NCS and from 5.3 to 7.9% for WS). Cryo-SEM images showed that the autoclave treatment led to the formation of a low-swelling, high-density gel network, whereas beta-amylolysis nearly demolished the network structure. The loss of A-type crystalline structure and the formation of B- and V-type structures resulted from autoclave, which suggests the formation of amylose-based ordered structure. Englyst assay indicated that, due to beta-amylolysis, the resistant starch (RS) content was increased to 30 from 11% of native NCS and to 23 from 9% of native WS. In contrast, autoclave showed only minor impact on RS levels. The increase of RS observed in this study is associated with enhanced branch density, which is different from the four types of RS commonly defined.

Properties of low-lying intruder states in $^{34}$Al and $^{34}$Si sequentially populated in $\\beta$-decay of $^{34}$Mg

CERN Multimedia

A low-lying long-lived (26±1 ms) isomer in $^{34}$Al has been observed recently and assigned as 1$^{+}$ state of intruder character. It was populated in $^{36}$S fragmentation and feeds, in $\\beta$-decay, the 0$_{2}^{+}$ state in $^{34}$Si whose excitation energy and lifetime were determined in an electron-positron pairs spectroscopy experiment. In the present experiment we intend to measure for the first time the $\\gamma$-rays following the $\\beta$-decay of $^{34}$Mg. Despite the interest for $^{34}$Mg, the up-right corner of the “N$\\thicksim$20 island of inversion”, the only information on its $\\beta$-decay is the lifetime of 20±10 ms, determined from $\\beta$-neutron coincidences. As a result of the proposed experiment, we expect to place the first transitions in the level scheme of $^{34}$Al and to strongly populate the newly observed isomer, measuring its excitation energy, if the branching ratio to 4$^{−}$ ground state is significant. Theoretical estimations for the $\\beta$-decay of the new isome...

A Novel Dimeric Inhibitor Targeting Beta2GPI in Beta2GPI/Antibody Complexes Implicated in Antiphospholipid Syndrome

Energy Technology Data Exchange (ETDEWEB)

A Kolyada; C Lee; A De Biasio; N Beglova

2011-12-31

{beta}2GPI is a major antigen for autoantibodies associated with antiphospholipid syndrome (APS), an autoimmune disease characterized by thrombosis and recurrent pregnancy loss. Only the dimeric form of {beta}2GPI generated by anti-{beta}2GPI antibodies is pathologically important, in contrast to monomeric {beta}2GPI which is abundant in plasma. We created a dimeric inhibitor, A1-A1, to selectively target {beta}2GPI in {beta}2GPI/antibody complexes. To make this inhibitor, we isolated the first ligand-binding module from ApoER2 (A1) and connected two A1 modules with a flexible linker. A1-A1 interferes with two pathologically important interactions in APS, the binding of {beta}2GPI/antibody complexes with anionic phospholipids and ApoER2. We compared the efficiency of A1-A1 to monomeric A1 for inhibition of the binding of {beta}2GPI/antibody complexes to anionic phospholipids. We tested the inhibition of {beta}2GPI present in human serum, {beta}2GPI purified from human plasma and the individual domain V of {beta}2GPI. We demonstrated that when {beta}2GPI/antibody complexes are formed, A1-A1 is much more effective than A1 in inhibition of the binding of {beta}2GPI to cardiolipin, regardless of the source of {beta}2GPI. Similarly, A1-A1 strongly inhibits the binding of dimerized domain V of {beta}2GPI to cardiolipin compared to the monomeric A1 inhibitor. In the absence of anti-{beta}2GPI antibodies, both A1-A1 and A1 only weakly inhibit the binding of pathologically inactive monomeric {beta}2GPI to cardiolipin. Our results suggest that the approach of using a dimeric inhibitor to block {beta}2GPI in the pathological multivalent {beta}2GPI/antibody complexes holds significant promise. The novel inhibitor A1-A1 may be a starting point in the development of an effective therapeutic for antiphospholipid syndrome.

Multi-wavelength imaging of solar plasma. High-beta disruption model of solar flares

International Nuclear Information System (INIS)

Shibasaki, Kiyoto

2007-01-01

Solar atmosphere is filled with plasma and magnetic field. Activities in the atmosphere are due to plasma instabilities in the magnetic field. To understand the physical mechanisms of activities / instabilities, it is necessary to know the physical conditions of magnetized plasma, such as temperature, density, magnetic field, and their spatial structures and temporal developments. Multi-wavelength imaging is essential for this purpose. Imaging observations of the Sun at microwave, X-ray, EUV and optical ranges are routinely going on. Due to free exchange of original data among solar physics and related field communities, we can easily combine images covering wide range of spectrum. Even under such circumstances, we still do not understand the cause of activities in the solar atmosphere well. The current standard model of solar activities is based on magnetic reconnection: release of stored magnetic energy by reconnection is the cause of solar activities on the Sun such as solar flares. However, recent X-ray, EUV and microwave observations with high spatial and temporal resolution show that dense plasma is involved in activities from the beginning. Based on these observations, I propose a high-beta model of solar activities, which is very similar to high-beta disruptions in magnetically confined fusion experiments. (author)

Evaluation of partial beta-adrenoceptor agonist activity.

Science.gov (United States)

Lipworth, B J; Grove, A

1997-01-01

A partial beta-adrenoceptor (beta-AR) agonist will exhibit opposite agonist and antagonist activity depending on the prevailing degree of adrenergic tone or the presence of a beta-AR agonist with higher intrinsic activity. In vivo partial beta-AR agonist activity will be evident at rest with low endogenous adrenergic tone, as for example with chronotropicity (beta 1/beta 2), inotropicity (beta 1) or peripheral vasodilatation and finger tremor (beta 2). beta-AR blocking drugs which have partial agonist activity may exhibit a better therapeutic profile when used for hypertension because of maintained cardiac output without increased systemic vascular resistance, along with an improved lipid profile. In the presence of raised endogenous adrenergic tone such as exercise or an exogenous full agonist, beta-AR subtype antagonist activity will become evident in terms of effects on exercise induced heart rate (beta 1) and potassium (beta 2) responses. Reduction of exercise heart rate will occur to a lesser degree in the case of a beta-adrenoceptor blocker with partial beta 1-AR agonist activity compared with a beta-adrenoceptor blocker devoid of partial agonist activity. This may result in reduced therapeutic efficacy in the treatment of angina on effort when using beta-AR blocking drugs with partial beta 1-AR agonist activity. Effects on exercise hyperkalaemia are determined by the balance between beta 2-AR partial agonist activity and endogenous adrenergic activity. For predominantly beta 2-AR agonist such as salmeterol and salbutamol, potentiation of exercise hyperkalaemia occurs. For predominantly beta 2-AR antagonists such as carteolol, either potentiation or attenuation of exercise hyperkalaemia occurs at low and high doses respectively. beta 2-AR partial agonist activity may also be expressed as antagonism in the presence of an exogenous full agonist, as for example attenuation of fenoterol induced responses by salmeterol. Studies are required to investigate whether

Beta2- and beta3-adrenoceptors activate glucose uptake in chick astrocytes by distinct mechanisms: a mechanism for memory enhancement?

Science.gov (United States)

Hutchinson, Dana S; Summers, Roger J; Gibbs, Marie E

2007-11-01

Isoprenaline, acting at beta-adrenoceptors (ARs), enhances memory formation in single trial discriminated avoidance learning in day-old chicks by mechanisms involving alterations in glucose and glycogen metabolism. Earlier studies of memory consolidation in chicks indicated that beta3-ARs enhanced memory by increasing glucose uptake, whereas beta2-ARs enhance memory by increasing glycogenolysis. This study examines the ability of beta-ARs to increase glucose uptake in chick forebrain astrocytes. The beta-AR agonist isoprenaline increased glucose uptake in a concentration-dependent manner, as did insulin. Glucose uptake was increased by the beta2-AR agonist zinterol and the beta3-AR agonist CL316243, but not by the beta1-AR agonist RO363. In chick astrocytes, reverse transcription-polymerase chain reaction studies showed that beta1-, beta2-, and beta3-AR mRNA were present, whereas radioligand-binding studies showed the presence of only beta2- and beta3-ARs. beta-AR or insulin-mediated glucose uptake was inhibited by phosphatidylinositol-3 kinase and protein kinase C inhibitors, suggesting a possible interaction between the beta-AR and insulin pathways. However beta2- and beta3-ARs increase glucose uptake by two different mechanisms: beta2-ARs via a Gs-cAMP-protein kinase A-dependent pathway, while beta3-ARs via interactions with Gi. These results indicate that activation of beta2- and beta3-ARs causes glucose uptake in chick astrocytes by distinct mechanisms, which may be relevant for memory enhancement.

BETA (Bitter Electromagnet Testing Apparatus)

Science.gov (United States)

Bates, Evan M.; Birmingham, William J.; Rivera, William F.; Romero-Talamas, Carlos A.

2017-10-01

The Bitter Electromagnet Testing Apparatus (BETA) is a 1-Tesla (T) prototype of the 10-T Adjustable Long Pulse High-Field Apparatus (ALPHA). These water-cooled resistive magnets use high DC currents to produce strong uniform magnetic fields. Presented here is the successful completion of the BETA project and experimental results validating analytical magnet designing methods developed at the Dusty Plasma Laboratory (DPL). BETA's final design specifications will be highlighted which include electromagnetic, thermal and stress analyses. The magnet core design will be explained which include: Bitter Arcs, helix starters, and clamping annuli. The final version of the magnet's vessel and cooling system are also presented, as well as the electrical system of BETA, which is composed of a unique solid-state breaker circuit. Experimental results presented will show the operation of BETA at 1 T. The results are compared to both analytical design methods and finite element analysis calculations. We also explore the steady state maximums and theoretical limits of BETA's design. The completion of BETA validates the design and manufacturing techniques that will be used in the succeeding magnet, ALPHA.

Single-phase {beta}-FeSi{sub 2} thin films prepared on Si wafer by femtosecond laser ablation and its photoluminescence at room temperature

Energy Technology Data Exchange (ETDEWEB)

Lu Peixiang [State Key Laboratory of Laser Technology and Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan 430074 (China)]. E-mail: lupeixiang@mail.hust.edu.cn; Zhou Youhua [State Key Laboratory of Laser Technology and Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan 430074 (China) and Physics and Information School, Jianghan University, Wuhan 430056 (China)]. E-mail: yhzhou@jhun.edu.cn; Zheng Qiguang [State Key Laboratory of Laser Technology and Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan 430074 (China); Yang Guang [State Key Laboratory of Laser Technology and Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan 430074 (China)

2006-02-06

Single-phase {beta}-FeSi{sub 2} thin films were prepared on Si(100) and Si(111) wafers by using femtosecond laser deposition with a FeSi{sub 2} alloy target for the first time. X-ray diffraction (XRD), field scanning electron microscopy (FSEM), scanning probe microscopy (SPM), electron backscattered diffraction pattern (EBSD), and Fourier-transform Raman infrared spectroscopy (FTRIS) were used to characterize the structure, composition, and properties of the {beta}-FeSi{sub 2}/Si films. The orientation of {beta}-FeSi{sub 2} grains was found to depend on the orientation of the Si substrates, and photoluminescence at wavelength of 1.53 {mu}m was observed from the single-phase {beta}-FeSi{sub 2}/Si thin film at room temperature (20 {sup o}C)

Prevalence of Co-Inheritance of Alpha-Thalassemia with Beta-Thalassemia and Beta-Hemoglobinopathy in Ahvaz City

Directory of Open Access Journals (Sweden)

Najmaddin Saki

2013-09-01

Full Text Available Background: Co-inheritance of hemoglobin gene defects is a rare important status that can lead to double heterozygote or homozygote with significant clinical manifestations. Such conditions can be observed in co-inheritance of alpha-thalassemia with beta-thalassemia or hemoglobinopathy. The aim of this study was to evaluate the prevalence of alpha-thalassemia with beta-thalassemia and hemoglobinopathy co-inheritance in a considerable number of Iranian.   Methods: This descriptive study was performed on patients with abnormal hematological findings in favor of alpha-thalassemia, beta-thalassemia or beta-hemoglobinopathies. Patients with low MCV and MCH levels and high HbA2 (>3.5 and those with low MCV and MCH and normal or low HbA2 were candidate for molecular analysis for beta and alpha thalassemia respectively. Abnormal Hb electrophoresis was diagnostic criteria for molecular analysis of beta-hemoglobinopathies.   Results: Study revealed that more than half of the patients with alpha-thalassemia affected simultaneously by beta-thalassemia and about thirty percent inherited beta-hemoglobinopathies. Among patients with beta-thalassemia, HbSCd6 (A-T was the most common mutation and in alpha-thalassemic patients α 3.7 was the commonest mutation.   Conclusion: Relatively high prevalence of co-inheritance of alfa-thalassemia with beta-thalassemia and hemoglobinopathies reflect the necessity of genetic consulting and molecular analysis in diagnosis of such conditions.

K and L X-ray emission intensities of some radionuclides

Energy Technology Data Exchange (ETDEWEB)

Verma, H R; Pal, D [Punjabi Univ., Patiala (India). Dept. of Physics

1985-01-01

The K and L x-ray emission intensities per 100 disintegrations have been calculated for some radionuclides using the latest adopted data for gamma-ray intensities, electron capture and internal conversion coefficients for the parent nuclides, fluorescence yield values, Coster-Kronig transition probabilities, average total number of primary L shell vacancies produced in the decay of K shell vacancies and emission rates for various shells and subshells for the daughter nuclei. The results are in good agreement with theoretical and experimental values for the K x-ray intensities. There are no experimental results available to compare with the present calculations for the L x-ray intensities; however, there is a marked discrepancy in the L..cap alpha.. and L..beta.. intensities available on the basis of theoretical estimates.

Betting against Beta

DEFF Research Database (Denmark)

Frazzini, Andrea; Heje Pedersen, Lasse

2014-01-01

We present a model with leverage and margin constraints that vary across investors and time. We find evidence consistent with each of the model's five central predictions: (1) Because constrained investors bid up high-beta assets, high beta is associated with low alpha, as we find empirically...

Physico-chemical and Biological Evaluation of Flavonols: Fisetin, Quercetin and Kaempferol Alone and Incorporated in beta Cyclodextrins.

Science.gov (United States)

Corina, Danciu; Bojin, Florina; Ambrus, Rita; Muntean, Delia; Soica, Codruta; Paunescu, Virgil; Cristea, Mirabela; Pinzaru, Iulia; Dehelean, Cristina

2017-01-01

Fisetin,quercetin and kaempferol are among the important representatives of flavonols, biological active phytocomounds, with low water solubility. To evaluate the antimicrobial effect, respectively the antiproliferative and pro apoptotic activity on the B164A5 murine melanoma cell line of pure flavonols and their beta cyclodextrins complexes. Incorporation of fisetin, quercetin and kaempferol in beta cyclodextrins was proved by scanning electron microscopy (SEM), differencial scanning calorimetry (DSC) and X-ray powder diffraction (XRPD). Pure compounds and their complexes were tested for antiproliferative (MTT) and pro-apoptotic activity (Annexin V-PI) on the B164A5 murine melanoma cell line and for the antimicrobial properties (Disk Diffusion Method) on the selected strains. The phytocompounds presented in a different manner in vitro chemopreventive activity against B164A5 murine melanoma cell line and weak antimicrobial effect. The three flavonols: fisetin, quercetin and kaempferol were successfully incorporated in beta-cyclodextrin (BCD) and hydroxylpropyl-beta-cyclodextrin (HPBCD). Incorporation in beta cyclodextrins had a mix effect on the biological activity conducing to decrease, increase or consistent effect compared to pure phytocompound, depending on the screened process and on the chosen combination. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Activity of beta-lactam beta-lactamase inhibitor combinations against extended spectrum beta-lactamase producing enterobacteriaceae in urinary isolates

International Nuclear Information System (INIS)

Iqbal, F.I.; Farooqi, B.J.

2012-01-01

Objective: To determine the susceptibility pattern of beta-lactam beta-lactamase inhibitor combinations against extended-spectrum beta-lactamase (ESBL) producing Enterobacteriaceae in urinary isolates. Study Design: Observational study. Place and Duration of Study: Ziauddin University Hospital, Karachi, from February to October 2008. Methodology: A total of 190 consecutive non-duplicate isolates of ESBL producing Enterobacteriaceae from urine samples of in-patients were included in the study. Urinary samples from out-patients, repeat samples and non-ESBL producing isolates were excluded. Detection of ESBL was carried out by double disk diffusion technique. Antimicrobial susceptibility testing was performed using modified Kirby Bauer's disk diffusion method according to CLSI guidelines. Statistical analysis was performed by SPSS version 10. Results: Of the 190 ESBL isolates tested, 88 cases (46.31%) were sensitive and 6 cases (3.15%) were resistant to all three combinations, the rest 96 cases (50.52%) were resistant to at least one of the combinations. Susceptibility pattern of cefoperazone/sulbactam, piperacillin/tazobactam, and amoxicillin/clavulanic acid was 95.26, 92.10, and 44.31 percent respectively. Conclusion: Cefoperazone/sulbactam exhibited the best activity against ESBL producing Enterobacteriaceae followed by piperacillin/tazobactam. Hospital antibiotic policies should be reviewed periodically to reduce the usage of extended spectrum cephalosporins and replace them with beta-lactam beta-lactamase inhibitor combinations agent for treating urinary tract infections. (author)

Tables of double beta decay data

Energy Technology Data Exchange (ETDEWEB)

Tretyak, V.I. [AN Ukrainskoj SSR, Kiev (Ukraine)]|[Strasbourg-1 Univ., 67 (France). Centre de Recherches Nucleaires; Zdesenko, Y.G. [AN Ukrainskoj SSR, Kiev (Ukraine)

1995-12-31

A compilation of experimental data on double beta decay is presented. The tables contain the most stringent known experimental limits or positive results of 2{beta} transitions of 69 natural nuclides to ground and excited states of daughter nuclei for different channels (2{beta}{sup -}; 2{beta}{sup +}; {epsilon}{beta}{sup +}; 2{epsilon}) and modes (0{nu}; 2{nu}; 0{nu}M) of decay. (authors). 189 refs., 9 figs., 3 tabs.

Electronic structure of beta-FeSi sub 2 obtained by maximum entropy method and photoemission spectroscopy

CERN Document Server

Kakemoto, H; Makita, Y; Kino, Y; Tsukamoto, T; Shin, S; Wada, S; Tsurumi, T

2003-01-01

The electronic structure of beta-FeSi sub 2 was investigated by maximum entropy method (MEM) and photoemission spectroscopy. The electronic structure obtained by MEM using X-ray diffraction data at room temperature (RT) showed covalent bonds of Fe-Si and Si-Si electrons. The photoemission spectra of beta-FeSi sub 2 at RT were changed by incidence photon energies. For photon energies between 50 and 100 eV, resonant photoemission spectra caused by a super Coster-Kronig transition were observed. In order to reduce resonant effect about Fe(3d) for obtained photoemission spectra, difference spectrum between 53 and 57 eV was calculated, and it was compared with ab-initio band calculation and spectra function.

Neutrophil beta-2 microglobulin: an inflammatory mediator

DEFF Research Database (Denmark)

Bjerrum, O W; Nissen, Mogens Holst; Borregaard, N

1990-01-01

Beta-2 microglobulin (beta 2m) constitutes the light invariant chain of HLA class I antigen, and is a constituent of mobilizable compartments of neutrophils. Two forms of beta 2m exist: native beta 2m and proteolytically modified beta 2m (Des-Lys58-beta 2m), which shows alpha mobility in crossed ...

Background studies of high energy γ rays from (n,γ) reactions in the CANDLES experiment

Science.gov (United States)

Nakajima, K.; Iida, T.; Akutagawa, K.; Batpurev, T.; Chan, W. M.; Dokaku, F.; Fushimi, K.; Kakubata, H.; Kanagawa, K.; Katagiri, S.; Kawasaki, K.; Khai, B. T.; Kino, H.; Kinoshita, E.; Kishimoto, T.; Hazama, R.; Hiraoka, H.; Hiyama, T.; Ishikawa, M.; Li, X.; Maeda, T.; Matsuoka, K.; Moser, M.; Nomachi, M.; Ogawa, I.; Ohata, T.; Sato, H.; Shamoto, K.; Shimada, M.; Shokati, M.; Takahashi, N.; Takemoto, Y.; Takihira, Y.; Tamagawa, Y.; Tozawa, M.; Teranishi, K.; Tetsuno, K.; Trang, V. T. T.; Tsuzuki, M.; Umehara, S.; Wang, W.; Yoshida, S.; Yotsunaga, N.

2018-07-01

High energy γ rays with several MeV produced by (n,γ) reactions can be a trouble for low background measurements in the underground laboratories such as double beta decay experiments. In the CANDLES project, which aimed to observe the neutrino-less double beta decay from 48Ca, γ rays caused by (n,γ) reactions were found to be the most significant background. The profile of the background was studied by measurements with a neutron source and a simulation with a validity check of neutron processes in Geant4. The observed spectrum of γ rays from (n,γ) reactions was well reproduced by the simulated spectra, which were originated from the surrounding rock and a detector tank made of stainless steel. The environmental neutron flux was derived by the observed event rate of γ rays from (n,γ) reactions using the simulation. The thermal and non-thermal neutron flux were found to be (1.3 ± 0.6) ×10-6 cm-2s-1 and (1.1 ± 0.5) ×10-5 cm-2s-1 , respectively. It is necessary to install an additional shield to reduce the background from (n,γ) reaction to the required level.

Beta-decay rate and beta-delayed neutron emission probability of improved gross theory

Science.gov (United States)

Koura, Hiroyuki

2014-09-01

A theoretical study has been carried out on beta-decay rate and beta-delayed neutron emission probability. The gross theory of the beta decay is based on an idea of the sum rule of the beta-decay strength function, and has succeeded in describing beta-decay half-lives of nuclei overall nuclear mass region. The gross theory includes not only the allowed transition as the Fermi and the Gamow-Teller, but also the first-forbidden transition. In this work, some improvements are introduced as the nuclear shell correction on nuclear level densities and the nuclear deformation for nuclear strength functions, those effects were not included in the original gross theory. The shell energy and the nuclear deformation for unmeasured nuclei are adopted from the KTUY nuclear mass formula, which is based on the spherical-basis method. Considering the properties of the integrated Fermi function, we can roughly categorized energy region of excited-state of a daughter nucleus into three regions: a highly-excited energy region, which fully affect a delayed neutron probability, a middle energy region, which is estimated to contribute the decay heat, and a region neighboring the ground-state, which determines the beta-decay rate. Some results will be given in the presentation. A theoretical study has been carried out on beta-decay rate and beta-delayed neutron emission probability. The gross theory of the beta decay is based on an idea of the sum rule of the beta-decay strength function, and has succeeded in describing beta-decay half-lives of nuclei overall nuclear mass region. The gross theory includes not only the allowed transition as the Fermi and the Gamow-Teller, but also the first-forbidden transition. In this work, some improvements are introduced as the nuclear shell correction on nuclear level densities and the nuclear deformation for nuclear strength functions, those effects were not included in the original gross theory. The shell energy and the nuclear deformation for

The transmission of differing energy beta particles through various materials

International Nuclear Information System (INIS)

Quayle, D.R.

1996-04-01

The transmission of beta particles is frequently calculated in the same fashion as that of gamma rays, where the mass attenuation coefficient is defined by the slope of the exponential function. Numerous authors have used this approximation including Evans (1955), Loevinger (1952), and Chabot et. al. (1988). Recent work by McCarthy et. al. (1995) indicated that the exponential function seemed to fit well over a particular region of the transmission curve. Upon further investigation, the author decided to verify McCarthy's results by the use of different absorber materials and attempt to reproduce the experiments. A theoretical method will be used to estimate the transmission of the beta particles through the three absorbers, aluminum, zirconium, and iron. An alternate Monte Carlo code, the Electron Gamma Shower version 4 code (EGS4) will also be used to verify that the experiment is approximating a pencil beam of beta particles. Although these two methods offer a good cross check for the experimental data, they pose a conflict in regards to the type of beam that is to be generated. The experimental lab setup uses a collimated beam of electrons that will impinge upon the absorber, while the codes are written using a pencil beam. A minor discrepancy is expected to be observed in the experimental results and is currently under investigation by McCarthy. The results of this project supported the theory that the beta mass attenuation coefficient was accurately represented by the slope of an exponential function, but only for that particular region of the transmission curve that has a minimal absorber thickness. By fitting the data beyond 50% of the beta particle range this theory does not hold true. The theory generated by McCarthy (1995) and the EGS4 Monte Carlo code indicated that the transmission curve for a pencil beam was not accurately represented by an exponential function. The results of this experiment appeared to provide additional support to this assumption

Beta measurement evaluation and upgrade

International Nuclear Information System (INIS)

Swinth, K.L.; Rathbun, L.A.; Roberson, P.L.; Endres, G.W.R.

1986-01-01

This program focuses on the resolution of problems associated with the field measurement of the beta dose component at Department of Energy (DOE) facilities. The change in DOE programs, including increased efforts in improved waste management and decontamination and decommissioning (D and D) of facilities, coupled with beta measurement problems identified at Three Mile Island has increased the need to improve beta measurements. In FY 1982, work was initiated to provide a continuing effort to identify problems associated with beta dose assessment at DOE facilities. The problems identified resulted in the development of this program. The investigation includes (1) an assessment of measurement systems now in use, (2) development of improved calibration systems and procedures, (3) application of innovative beta dosimetry concepts, (4) investigation of new instruments or concepts for monitoring and spectroscopy, and (5) development of recommendations to assure an adequate beta measurement program within DOE facilities

Expression, purification, crystallization and preliminary X-ray analysis of Aeromonas hydrophilia metallo-[beta]-lactamase

Energy Technology Data Exchange (ETDEWEB)

Sharma, N.; Toney, J.H.; Fitzgerald, P.M.D. (Merck)

2010-07-20

The CphA metallo-{beta}-lactamase from Aeromonas hydrophilia has been expressed, purified and crystallized by the hanging-drop vapor-diffusion method using ammonium sulfate as the precipitant. The crystals exhibit orthorhombic symmetry (P2{sub 1}2{sub 1}2), with unit-cell parameters a = 40.75, b = 42.05, c = 128.88 {angstrom}. There is one monomer in the asymmetric unit and the solvent content is estimated to be 44% by volume. A data set extending to 1.8 {angstrom} has been measured.

Interactions between an alpha-helix and a beta-sheet. Energetics of alpha/beta packing in proteins.

Science.gov (United States)

Chou, K C; Némethy, G; Rumsey, S; Tuttle, R W; Scheraga, H A

1985-12-05

Conformational energy computations have been carried out to determine the favorable ways of packing a right-handed alpha-helix on a right-twisted antiparallel or parallel beta-sheet. Co-ordinate transformations have been developed to relate the position and orientation of the alpha-helix to the beta-sheet. The packing was investigated for a CH3CO-(L-Ala)16-NHCH3 alpha-helix interacting with five-stranded beta-sheets composed of CH3CO-(L-Val)6-NHCH3 chains. All internal and external variables for both the alpha-helix and the beta-sheet were allowed to change during energy minimization. Four distinct classes of low-energy packing arrangements were found for the alpha-helix interacting with both the parallel and the anti-parallel beta-sheet. The classes differ in the orientation of the axis of the alpha-helix relative to the direction of the strands of the right-twisted beta-sheet. In the class with the most favorable arrangement, the alpha-helix is oriented along the strands of the beta-sheet, as a result of attractive non-bonded side-chain-side-chain interactions along the entire length of the alpha-helix. A class with nearly perpendicular orientation of the helix axis to the strands is also of low energy, because it allows similarly extensive attractive interactions. In the other two classes, the helix is oriented diagonally relative to the strands of the beta-sheet. In one of them, it interacts with the convex surface near the middle of the saddle-shaped twisted beta-sheet. In the other, it is oriented along the concave diagonal of the beta-sheet and, therefore, it interacts only with the corner regions of the sheet, so that this packing is energetically less favorable. The packing arrangements involving an antiparallel and a parallel beta-sheet are generally similar, although the antiparallel beta-sheet has been found to be more flexible. The major features of 163 observed alpha/beta packing arrangements in 37 proteins are accounted for in terms of the computed

Kinematic shifts of beta -delayed particles as a probe of beta - nu angular correlations

CERN Document Server

Clifford, E T H; Evans, H C; Fästermann, T; Hagberg, E; Hardy, J C; Jackson, K P; Koslowsky, V T; Schmeing, H; Schrewe, U J

1981-01-01

Beta-delayed particles undergo a kinematic shift in energy due to recoil motion of the daughter nucleus following beta decay. A careful measurement of this energy shift can be used to establish the ratio of vector to axial vector components in beta transitions. Alpha-beta coincidence data for the beta-delayed alpha decay of /sup 20/Na have been obtained. Component ratios for 6 transitions including the superallowed branch are found. Limits on charge dependent mixing with the analogue state are deduced for 5 states in /sup 20/Ne*. For the superallowed branch the axial vector component is found; the polar vector component is deduced and establishes a value for the vector weak coupling constant of G/sub V/=(1.355+or-0.036)*10/sup -49/ erg cm /sup 3/. (13 refs).

RESEARCH OF BETA AS ADEQUATE RISK MEASURE-IS BETA STILL ALIVE?

Directory of Open Access Journals (Sweden)

Ante Perković

2011-02-01

Full Text Available The capital asset pricing model (CAPM is one of the most important models in financial economics and it has a long history of theoretical and empirical investigations. The main underlying concept of the CAPM model is that assets with a high risk (high beta should earn a higher return than assets with a low risk (low beta and vice versa. The implication which can be drawn out of this is that all assets with a beta above zero bear some risk and therefore their expected return is above the return of the risk-free rate. In this research observation on monthly stock prices on Croatian stock market from January 1st 2005 until December 31st 2009 is used to form our sample. CROBEX index is used as proxy of the market portfolio. The results demonstrate that beta can not be trusted in making investment decisions and rejects the validity of the whole CAPM model on Croatian stock market.

Interleukin-1 beta gene deregulation associated with chromosomal rearrangement: A candidate initiating event for murine radiation-myeloid leukemogenesis

International Nuclear Information System (INIS)

Silver, A.; Boultwood, J.; Breckon, G.; Masson, W.; Adam, J.; Shaw, A.R.; Cox, R.

1989-01-01

The incidence of acute myeloid leukemia (AML) in CBA/H mice following exposure to single acute doses of ionizing radiation has previously been determined. A high proportion of these AMLs are characterized by rearrangement of murine chromosome 2 in the C2 and/or E5-F regions, and there is evidence that these events are a direct consequence of radiation damage to multipotential hemopoietic cells. Using a combination of in situ chromosome hybridization and mRNA analyses, we show that the cytokine gene interleukin-1 beta (IL-1 beta) is encoded in the chromosome 2 F region and is translocated in a chromosome 2---2 rearrangement in an x-ray-induced AML (N36). Also, IL-1 beta is specifically deregulated in N36 and in two other chromosome 2-rearranged AMLs but not in a fourth, which has two cytogenetically normal chromosome 2 copies. We suggest that radiation-induced specific chromosome 2 rearrangement associated with IL-1 beta deregulation may initiate murine leukemogenesis through the uncoupling of normal proliferative control mechanisms in multipotential hemopoietic cells

Thermoluminescence of europium-doped zinc oxide exposed to beta particle irradiation

Energy Technology Data Exchange (ETDEWEB)

Iriqui R, J. L.; Cruz V, C. [Universidad de Sonora, Departamento de Investigacion en Polimeros y Materiales, Apdo. Postal 130, 83000 Hermosillo, Sonora (Mexico); Bernal, R. [Universidad de Sonora, Departamento de Investigacion en Fisica, Apdo. Postal 5-088, 83000 Hermosillo, Sonora (Mexico); Castano, V. M., E-mail: jorgeiriqui@gimmunison.com [UNAM, Instituto de Fisica, Centro de Fisica Aplicada y Tecnologia Avanzada, Apdo. Postal 1-1010, 76000 Queretaro, Qro. (Mexico)

2015-10-15

Full text: Zn O is a promising material for a range of optoelectronics applications, due to its direct wide band gap (E{sub g} ∼3.3 eV at 300 K) and large exciton binding energy (60 MeV). Its applications include UV light emitters, varistors, surface acoustic wave devices, piezoelectric transducers, and chemical and gas sensing. Rare-earth activation of phosphors has long been seen as an effective process since coupling energy into the rare-earth-ion site, either by ionization, charge exchange or a resonance energy process, results in light production. It is reported that Europium modifies the response thermoluminescence (Tl) for pure zinc oxide, when is irradiated with X-ray, created a peak at 365 degrees C. In this work, Zn O:Eu phosphors were synthesized by a chemical method. Some samples were exposed to beta particle irradiation for doses ranging from 1 up to 100 Gy. Tl response as a function of dose is linear throughout the studied dose range. The glow curve exhibits three maxima, centered at 176, 279 and 340 degrees C. The reusability studies obtained after ten repeated cycles of annealing irradiation readout for the Zn O:Eu shows that the variation in the Tl response is ten percent and tends to stabilization. The results indicate that these new Zn O:Eu phosphors are promising detectors and dosimeters for beta radiation. The structural and morphological characterization was carried out by X-ray diffraction and scanning electron microscopy, respectively. (Author)

Regulation of the friction coefficient of articular cartilage by TGF-beta1 and IL-1beta.

Science.gov (United States)

DuRaine, Grayson; Neu, Corey P; Chan, Stephanie M T; Komvopoulos, Kyriakos; June, Ronald K; Reddi, A Hari

2009-02-01

Articular cartilage functions to provide a low-friction surface for joint movement for many decades of life. Superficial zone protein (SZP) is a glycoprotein secreted by chondrocytes in the superficial layer of articular cartilage that contributes to effective boundary lubrication. In both cell and explant cultures, TGF-beta1 and IL-1beta have been demonstrated to, respectively, upregulate and downregulate SZP protein levels. It was hypothesized that the friction coefficient of articular cartilage could also be modulated by these cytokines through SZP regulation. The friction coefficient between cartilage explants (both untreated and treated with TGF-beta1 or IL-1beta) and a smooth glass surface due to sliding in the boundary lubrication regime was measured with a pin-on-disk tribometer. SZP was quantified using an enzyme-linked immunosorbant assay and localized by immunohistochemistry. Both TGF-beta1 and IL-1beta treatments resulted in the decrease of the friction coefficient of articular cartilage in a location- and time-dependent manner. Changes in the friction coefficient due to the TGF-beta1 treatment corresponded to increased depth of SZP staining within the superficial zone, while friction coefficient changes due to the IL-1beta treatment were independent of SZP depth of staining. However, the changes induced by the IL-1beta treatment corresponded to changes in surface roughness, determined from the analysis of surface images obtained with an atomic force microscope. These findings demonstrate that the low friction of articular cartilage can be modified by TGF-beta1 and IL-1beta treatment and that the friction coefficient depends on multiple factors, including SZP localization and surface roughness.

Development of a gas-ionization {beta}-spectrometer; Etude et realisation d'un spectrometre {beta} a ionisation gazeuse

Energy Technology Data Exchange (ETDEWEB)

Le Du, R [Commissariat a l' Energie Atomique, Bruyeres-le-Chatel (France). Centre d' Etudes

1968-05-15

We intend to develop in our laboratory a {beta}-spectrometer. This apparatus will have two main objectives: 1 - the determination of the nature and the degree of purity of certain {beta}-emitting radioactive substances; 2 - the study of an activity calibration process for {beta}-emitting radioactive sources. (author) [French] Nous nous proposons d'etudier et de realiser dans notre laboratoire un spectrometre {beta}. Cet appareil aura deux buts principaux: 1 - determiner la nature et le degre de purete de certains corps radioactifs emetteurs {beta}; 2 - permettre l'etude d'un procede d'etalonnage en activite de sources radioactives emetteurs {beta}. (auteur)

A new irradiated quartz for beta source calibration

DEFF Research Database (Denmark)

Hansen, Vicki; Murray, Andrew Sean; Buylaert, Jan-Pieter

2015-01-01

For luminescence dating to be an accurate absolute dating technique it is very important that we are able to deliver absolutely known radiation doses in the laboratory. This is normally done using a radiation source (alpha, beta, X-ray) calibrated against an absolutely known reference source. Man...... doses from a standardised gamma source to in-built irradiation sources....... from south-western Denmark (Rømø). Two grain sizes (4-11μm and 180-250μm) have been examined in detail. These were pre-treated (annealed, dosed and annealed again) to sensitise and stabilise the luminescence signals before being given an absolutely known gamma dose from a point 137Cs source in scatter...

Synthesis of the {beta}-phenethyl-mercaptan ({sup 35}S); Synthese du {beta}-phenethylmercaptan ({sup 35}S)

Energy Technology Data Exchange (ETDEWEB)

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

1957-07-01

{beta}-phenethyl-mercaptan ({sup 35}S) has been synthesized by action of elementary radioactive sulphur ({sup 35}S) on {beta}-phenethyl-magnesium-bromide, with a 90 per cent yield. (author) [French] Le {beta}-phenethylmercaptan ({sup 35}S) a ete synthetise par action du soufre radioactif elementaire ({sup 35}S) sur le bromure de {beta}-phenethylmagnesium, avec un rendement de 90 pour cent. (auteur)

Beta Instability and Stochastic Market Weights

OpenAIRE

David H. Goldenberg

1985-01-01

An argument is given for individual firm beta instability based upon the stochastic character of the market weights defining the market portfolio and the constancy of its beta. This argument is generalized to market weighted portfolios and the form of the stochastic process generating betas is linked to that of the market return process. The implications of this analysis for adequacy of models of beta nonstationarity and estimation of betas are considered in light of the available empirical e...

The effects of lower than conventional doses of oral nadolol on relative beta 1/beta 2-adrenoceptor blockade.

Science.gov (United States)

Wheeldon, N M; McDevitt, D G; Lipworth, B J

1994-08-01

1. The aim of the present study was to evaluate the relative beta 1/beta 2 antagonist selectivity of the beta-adrenoceptor blocker nadolol, in lower than conventional clinical doses. 2. Eight normal volunteers received single oral doses of either placebo (PL), nadolol 5 mg (N5), 20 mg (N20) or 80 mg (N80) in a single-blind, randomised crossover design. beta 1-adrenoceptor antagonism was assessed by attenuation of exercise tachycardia, and beta 2-adrenoceptor blockade by effects on salbutamol-induced chronotropic, hypokalaemic and finger tremor responses. The relative percentage attenuation of beta 2 and beta 1-mediated responses was calculated and expressed as beta 2:beta 1 selectivity ratios. 3. Nadolol produced dose-related reductions in exercise tachycardia in keeping with increasing beta 1-adrenoceptor blockade; mean % reduction (95% CI) compared with placebo: N5 10.7 (6.6 to 14.8), N20 21.4 (17.3 to 25.4), N80 38.9 (34.8 to 42.9). However, even the lowest dose of nadolol (5 mg) produced almost complete blunting of beta 2-mediated effects and significantly increase exercise hyperkalaemia; peak exercise hyperkalaemia (mmol l-1) (means and 95% CI): PL 4.88 (4.68 to 5.07), N5 5.36 (5.17 to 5.55), N20 5.48 (5.28 to 5.67), N80 5.42 (5.22 to 5.61). beta 2:beta 1 selectivity ratios significantly increased as the dose of nadolol was reduced. 4. These data suggest that whereas in the clinical dose range nadolol behaves as a non-selective beta-adrenoceptor antagonist, as the dose is reduced this drug demonstrates an increasing degree of selectivity for the beta 2-adrenoceptor.(ABSTRACT TRUNCATED AT 250 WORDS)

Expression of 11beta-hydroxysteroid dehydrogenase 1 and 2 in subcutaneous adipose tissue of lean and obese women with and without polycystic ovary syndrome

DEFF Research Database (Denmark)

Svendsen, P F; Madsbad, S; Nilas, L

2009-01-01

OBJECTIVE: To investigate the expression of 11beta-hydroxysteroid dehydrogenase (11beta-HSD) type 1 and 2 and hexose-6-phosphate dehydrogenase (H6PDH) mRNA in subcutaneous abdominal tissue from lean and obese women with and without polycystic ovary syndrome (PCOS), and to investigate...... assessment insulin resistance index. Body composition was evaluated by dual X-ray absorptiometry. Adipose mRNA expression of leptin and adiponectin were determined by real-time PCR. RESULTS: Polycystic ovary syndrome (P... distribution (PPolycystic ovary syndrome and obesity are independently associated with increased expression of 11beta-HSD1. This may lead to increased conversion of cortisone to cortisol...

Thermoluminescent dosimetry of beta radiations of 90 Sr/ 90 Y using ZrO2: Eu

International Nuclear Information System (INIS)

Olvera T, L.; Azorin N, J.; Barrera S, M.; Soto E, A.M.; Rivera M, T.

2005-01-01

In this work the results of studying the thermoluminescent properties (TL) of the doped zirconium oxide with europium (ZrO 2 : Eu 3+ ) before beta radiations of 90 Sr/ 90 Y are presented. The powders of ZrO 2 : Eu 3+ were obtained by means of the sol-gel technique and they were characterized by means of thermal analysis and by X-ray diffraction. The powders of ZrO 2 : Eu 3+ , previously irradiated with beta particles of 90 Sr/ 90 Y, presented a thermoluminescent curve with two peaks at 204 and 292 C respectively. The TL response of the ZrO 2 : Eu 3+ as function of the absorbed dose was lineal from 2 Gy up to 90 Gy. The fading of the information of the ZrO 2 : Eu 3+ was of 10% the first 2 hours remaining almost constant the information by the following 30 days. The ZrO 2 doped with the (Eu 3+ ) ion it was found more sensitive to the beta radiation that the one of zirconium oxide without doping (ZrO 2 ) obtained by the same method. Those studied characteristics allow to propose to the doped zirconium oxide with europium like thermoluminescent dosemeter for the detection of the beta radiation. (Author)

Atualizações sobre beta-hidroxi-beta-metilbutirato: suplementação e efeitos sobre o catabolismo de proteínas New findings on beta-hydroxy-beta-methylbutyirate: supplementation and effects on the protein catabolism

Directory of Open Access Journals (Sweden)

Everson Araújo Nunes

2008-04-01

Full Text Available O beta-hidroxi-beta-metilbutirato, metabólito do aminoácido leucina, vem sendo utilizado como suplemento alimentar, em situações específicas, com o intuito de aumentar ou manter a massa isenta de gordura. Os relatos dos efeitos do beta-hidroxi-beta-metilbutirato em estudos recentes fizeram crescer as expectativas sobre sua utilização em casos patológicos. Também foram demonstrados melhores resultados, quando da sua ingestão, no treinamento de força em indivíduos iniciantes e em idosos. Em humanos o beta-hidroxi-beta-metilbutirato tem sido usado como agente anti-catabólico, e em modelos animais foi demonstrado ser eficaz em inibir a atividade de vias proteolíticas em células musculares de indivíduos caquéticos in vitro e in vivo. Os mecanismos participantes desses processos envolvem: a inibição da atividade do sistema ubiquitina proteossoma ATP-dependente, a inibição de vias de sinalização com participação da proteína quinase C-alfa e a diminuição da concentração citoplasmática do fator nuclear - kappa B livre, eventos relacionados ao decréscimo da proteólise em células musculares.The leucine metabolite beta-hydroxy-beta-methylbutyrate has been used as a nutritional supplement in specific situations to prevent losing or to increase lean mass. Recent studies showed interesting results of beta-hydroxy-beta-methylbutyrate supplementation in certain disease states. Better results have also been demonstrated when it is taken by starters or old individuals doing strength training. In humans, beta-hydroxy-beta-methylbutyrate has been used as an anticatabolic agent and in animal models it has been demonstrated to be effective in inhibiting the activity of the proteolytic pathways in muscle cells of extremely weak individuals in vivo and in vitro. The mechanisms that participate in this process involve: inhibition of the ATP-ubiquitin-proteasome pathway, inhibition of the signalization pathways involving protein kinase C

High beta tokamaks

International Nuclear Information System (INIS)

Dory, R.A.; Berger, D.P.; Charlton, L.A.; Hogan, J.T.; Munro, J.K.; Nelson, D.B.; Peng, Y.K.M.; Sigmar, D.J.; Strickler, D.J.

1978-01-01

MHD equilibrium, stability, and transport calculations are made to study the accessibility and behavior of ''high beta'' tokamak plasmas in the range β approximately 5 to 15 percent. For next generation devices, beta values of at least 8 percent appear to be accessible and stable if there is a conducting surface nearby

Characterization of a beta-glycosidase highly active on disaccharides and of a beta-galactosidase from Tenebrio molitor midgut lumen.

Science.gov (United States)

Ferreira, Alexandre H P; Terra, Walter R; Ferreira, Clélia

2003-02-01

The midgut of the yellow mealworm, Tenebrio molitor L. (Coleoptera: Tenebrionidae) larvae has four beta-glycosidases. The properties of two of these enzymes (betaGly1 and betaGly2) have been described elsewhere. In this paper, the characterization of the other two glycosidases (betaGly3 and betaGly4) is described. BetaGly3 has one active site, hydrolyzes disaccharides, cellodextrins, synthetic substrates and beta-glucosides produced by plants. The enzyme is inhibited by amygdalin, cellotriose, cellotetraose and cellopentaose in high concentrations, probably due to transglycosylation. betaGly3 hydrolyzes beta 1,4-glycosidic linkages with a catalytic rate independent of the substrate polymerization degree (k(int)) of 11.9 s(-1). Its active site is formed by four subsites, where subsites +1 and -1 bind glucose residues with higher affinity than subsite +2. The main role of betaGly3 seems to be disaccharide hydrolysis. BetaGly4 is a beta-galactosidase, since it has highest activity against beta-galactosides. It can also hydrolyze fucosides, but not glucosides, and has Triton X-100 as a non-essential activator (K(a)=15 microM, pH 4.5). betaGly4 has two active sites that can hydrolyze p-nitrophenyl beta-galactoside (NPbetaGal). The one hydrolyzing NPbetaGal with more efficiency is also active against methylumbellipheryl beta-D-galactoside and lactose. The other active site hydrolyzes NPbetaFucoside and binds NPbetaGal weakly. BetaGly4 hydrolyzes hydrophobic substrates with high catalytical efficiency and is able to bind octyl-beta-thiogalactoside in its active site with high affinity. The betaGly4 physiological role is supposed to be the hydrolysis of galactolipids that are found in membranes from vegetal tissues. As the enzyme has a hydrophobic site where Triton X-100 can bind, it might be activated by membrane lipids, thus becoming fully active only at the surface of cell membranes.

Dynamic returns of beta arbitrage

OpenAIRE

Nascimento, Mafalda

2017-01-01

This thesis studies the patterns of the abnormal returns of the beta strategy. The topic can be helpful for professional investors, who intend to achieve a better performance in their portfolios. Following the methodology of Lou, Polk, & Huang (2016), the COBAR measure is computed in order to determine the levels of beta arbitrage in the market in each point in time. It is argued that beta arbitrage activity can have impact on the returns of the beta strategy. In fact, it is demonstrated that...

Depolymerization of schizophyllan by gamma-ray irradiation

Energy Technology Data Exchange (ETDEWEB)

Tabata, Kengo; Ito, Wataru; Hirata, Akio; Kojima, Takemasa [Taito Co. Ltd., Kobe (Japan). Research Lab.

1992-11-01

Schizophyllan, an antitumor (1 [yields] 3)-[beta]-D-glucan that takes on a triple helical structure in aqueous solution, was irradiated with gamma-ray at doses of 0.058 to 8.4 Mrad. The molecular weight of the polysaccharide decreased as the dose of radiation increased, and the number of reducing group increased. Methylation analysis by enzymic hydrolysis with exo-[beta]-1,3-glucanase and antitumor tests showed that the polysaccharide after irradiation at 0.058 or 0.26 Mrad had essentially the same chemical structure and antitumor activity as native schizophyllan. Treatment at 2 or 8.4 Mrad caused changes in the chemical structure and antitumor activity. The depolymerization mechanism seemed to be different from that caused by ultrasonic treatment or hydrodynamic shearing, because irradiation most readily caused changes in the chemical structure and antitumor activity. (author).

Equine endometrial fibrosis correlates with 11beta-HSD2, TGF-beta1 and ACE activities.

Science.gov (United States)

Ganjam, V K; Evans, T J

2006-03-27

Endometrial periglandular fibrosis (EPF) contributes to embryonic and fetal loss in mares. Equine EPF correlates inversely with conception and successful gestation. In the modified Kenney endometrial biopsy classification system, EPF categories I, IIA, IIB, and III correspond to minimal, mild, moderate, and severe fibrosis (+/-inflammation), respectively. Paraffin sections of biopsy specimens were stained with H&E, and picrosirius red (specific for fibrillar collagens types I and III), to determine %EPCVF. Endometrial ACE-binding activity, TGF-beta1 and 11beta-HSD2 activities were also measured. Ultrastructural changes in EPF categories IIB and III endometria strongly suggested myofibroblastic transformation. ACE-binding activity was highest in EPF category IIB; however, endometrial TGF-beta1 and 11beta-HSD2 activities were significantly correlated to the severity of EPF (P<0.05). We conclude that, locally generated angiotensin II initiates the expression of TGF-beta1 resulting in myofibroblastic transformation. 11Beta-HSD2 in concert appears to modulate the severity of endometrial fibrosis.

Soft X-ray Tangential Imaging of the NSTX Core Plasma by Means of a MPGD Pin-hole Camera

International Nuclear Information System (INIS)

Pacella, D.; Leigheb, M.; Bellazzini, R.; Brez, A.; Finkenthal, M.; Stutman, D.; Kaita, R.; Sabbagh, S.A.

2003-01-01

A fast X-ray system based on a Micro Pattern Gas Detector has been used, for the first time, to investigate emission from the plasma core of the National Spherical Tokamak eXperiment (NSTX) at the Princeton Plasma Physics Laboratory. The results presented in this work demonstrate the capability of such a device to measure with a time resolution of the order of 1 ms the curvature and the elongation of the X-ray iso-emissivity contours, under various plasma conditions. Also, comparisons with the magnetic surface structure calculated by the EFIT code show good agreement between reconstructed flux surface and the soft X-ray emissions (SXR) for poloidal beta values up to 0.6. For greater values of beta, X-ray iso-emissivity contours become circular, while magnetic flux surface reconstructions yield elongation 1.5 < k < 2.2. The X-ray images have been acquired with a (statistical) signal to noise ratio (SNR) per pixel of about 30. Thanks to the direct and efficient X-ray conversion and its operation in a photon counting mode, this new diagnostic tool allows the routine investigation of the plasma core with a sampling rate of 1 kHz and extremely high SNR under all experimental conditions in NSTX

[{sup 125}I]{beta}-CIT-FE and [{sup 125}I]{beta}-CIT-FP are superior to [{sup 125}I]{beta}-CIT for dopamine transporter visualization: Autoradiographic evaluation in the human brain

Energy Technology Data Exchange (ETDEWEB)

Guenther, Ilonka; Hall, Haakan; Halldin, Christer; Swahn, Carl-Gunnar; Farde, Lars; Sedvall, Goeran

1997-10-01

The binding of the three dopamine transporter radioligands ([{sup 125}I]{beta}-CIT, [{sup 125}I]{beta}-CIT-FE, and [{sup 125}I]{beta}-CIT-FP) was studied using whole-hemisphere autoradiography on postmortem human brains. The autoradiograms revealed an intense and homogeneous labeling of the nucleus caudatus and putamen but also to varying extent to serotonergic and noradrenergic transporters of neocortex and thalamus. The order of specificity estimated (striatum over neocortex ratios) was {beta}-CIT-FP > {beta}-CIT-FE >> {beta}-CIT, suggesting that {beta}-CIT-FE and {beta}-CIT-FP should be preferred for in vivo studies of the dopamine transporter in the human brain.

A comparison of heart function and arrhythmia in clinically asymptomatic patients with beta thalassemia intermedia and beta thalassemia major.

Science.gov (United States)

Amoozgar, Hamid; Zeighami, Samaneh; Haghpanah, Sezaneh; Karimi, Mehran

2017-01-01

The goal of this study was to compare heart function and arrhythmia in clinically asymptomatic patients with beta thalassemia intermedia and beta thalassemia major. In this cross-sectional study, 60 patients with beta thalassemia major and 60 patients with beta thalassemia intermedia who had clinically no symptoms of arrhythmia and clinically normal heart function were evaluated using 24-hour ambulatory electrocardiogram monitoring and echocardiography. For data analysis SPSS ver.20 software was used. A P-value of less than 0.05 was considered statistically significant. The mean age of the beta thalassemia intermedia patients was 24.18 ± 7.9 years and the mean age in beta thalassemia major was 24.38 ± 7.7 years (P>0.05). Premature atrial contractions (PACs) were observed in 14 (23.3%) patients with beta thalassemia intermedia and in 22 (36.6%) beta thalassemia major patients. Premature ventricular contractions (PVCs) were detected in 8 (13.3%) patients in the beta thalassemia intermediate group and 16 (26.6) patients in the beta thalassemia major group, respectively. The left ventricular diastolic dimension, end-diastolic volume, and stroke volume were significantly higher in beta thalassemia intermedia group (Pintermedia group. Both atrial and ventricular arrhythmias were more common in the beta thalassemia major group. Higher end-diastolic volume and stroke volume were detected in the beta thalassemia intermedia group. Pulmonary acceleration time was lower in the beta thalassemia intermedia group, which can be an indicator of higher pulmonary pressure.

Integration of BETA with Eclipse

DEFF Research Database (Denmark)

Andersen, Peter; Madsen, Ole Lehrmann; Enevoldsen, Mads Brøgger

2004-01-01

This paper presents language interoperability issues appearing in order to implement support for the BETA language in the Java-based Eclipse integrated development environment. One of the challenges is to implement plug-ins in BETA and be able to load them in Eclipse. In order to do this, some fo...... it is possible to implement plug-ins in BETA and even inherit from Java classes. In the paper the two approaches are described together with part of the mapping from BETA to Java class files. http://www.sciencedirect.com/science/journal/15710661...

Characterization of the beta-lactam binding site of penicillin acylase of Escherichia coli by structural and site-directed mutagenesis studies

NARCIS (Netherlands)

Alkema, WBL; Hensgens, CMH; Kroezinga, EH; de Vries, E; Floris, R; van der Laan, JM; Dijkstra, BW; Janssen, DB

2000-01-01

The binding of penicillin to penicillin acylase was studied by X-ray crystallography, The structure of the enzyme-substrate complex was determined after soaking crystals of an inactive beta N241A penicillin acylase mutant with penicillin G, Binding of the substrate induces a conformational change,

Estimation of potassium concentration in coconut water by beta radioactivity measurement

International Nuclear Information System (INIS)

Reddy, P.J.; Narayani, K.; Bhade, S.P.D.; Anilkumar, S.; Kolekar, R.V.; Singh, Rajvir; Pradeepkumar, K.S.

2014-01-01

Potassium is widely distributed in soil, in all vegetable, fruits and animal tissues. Approximately half the radioactivity found in humans comes from 40 K. Potassium is an essential element in our diet since it is required for proper nerve and muscle function, as well as for maintaining the fluid balance of cells and heart rhythm. Potassium can enter the body mainly consuming fruits, vegetables and food. Tender coconut water is consumed widely as natural refreshing drink which is rich in potassium. The simple way to determine 40 K activity is by gamma ray spectrometry. However, the low abundance of this gamma photon makes the technique less sensitive compared to gross beta measurement. Many analytical methods are reported for potassium estimation which is time consuming and destructive in nature. A unique way to estimate 40 K by beta activity is by Cerenkov Counting technique using Liquid Scintillation Analyzer. Also much lower detection limit is achieved, allowing for greater precision. In this work, we have compared two methods to arrive at the potassium concentration in tender and matured coconut water by measuring 40 K. One is non-scintillator method based on measurement of the Cerenkov radiation generated from the high-energy β of 40 K. The second method is based on beta activity measurement using low background Gas flow counter

Thymosin beta 4 and thymosin beta 10 expression in hepatocellular carcinoma

Directory of Open Access Journals (Sweden)

W. Theunissen

2014-03-01

Full Text Available Thymosin beta 4 (Tβ4 and thymosin beta 10 (Tβ10 are two members of the beta-thymosin family involved in many cellular processes such as cellular motility, angiogenesis, inflammation, cell survival and wound healing. Recently, a role for beta-thymosins has been proposed in the process of carcinogenesis as both peptides were detected in several types of cancer. The aim of the present study was to investigate the expression pattern of Tβ4 and Tβ10 in hepatocellular carcinoma (HCC. To this end, the expression pattern of both peptides was analyzed in liver samples obtained from 23 subjects diagnosed with HCC. Routinely formalin-fixed and paraffin-embedded liver samples were immunostained by indirect immunohistochemistry with polyclonal antibodies to Tβ4 and Tβ10. Immunoreactivity for Tβ4 and Tβ10 was detected in the liver parenchyma of the surrounding tumor area. Both peptides showed an increase in granular reactivity from the periportal to the periterminal hepatocytes. Regarding HCC, Tβ4 reactivity was detected in 7/23 cases (30% and Tβ10 reactivity in 22/23 (97% cases analyzed, adding HCC to human cancers that express these beta-thymosins. Intriguing finding was seen looking at the reactivity of both peptides in tumor cells infiltrating the surrounding liver. Where Tβ10 showed a strong homogeneous expression, was Tβ4 completely absent in cells undergoing stromal invasion. The current study shows expression of both beta-thymosins in HCC with marked differences in their degree of expression and frequency of immunoreactivity. The higher incidence of Tβ10 expression and its higher reactivity in tumor cells involved in stromal invasion indicate a possible major role for Tβ10 in HCC progression.

Double beta radioactivity and physics of the neutrino. Study of the background noise at 3 MeV in the search of 100Mo beta beta decay

International Nuclear Information System (INIS)

Piquemal, F.

1994-05-01

Double beta decay without neutrino emission provides a test of the mass and nature of neutrinos (Majorana or Dirac). Experimental proof would be the observation of a peak at the transition energy in the spectrum of the two emitted electrons. The expected half-life of the process is extremely long (about 10 25 years for 100 Mo). So, being thus, it is very important to get a good knowledge of the origins and contributions of background noise in the region where the signal could occur. The main origins of the background noise in the region where the signal could occur. The main origins of the background noise are found to be e + - e - pairs induced by heavy energy gamma rays. These gamma rays follow the thermal neutron capture by the components of the detector. Another factor in the production of background noise is natural radio-activity. For example, the presence of Radon in the laboratory has been observed to produce deposits of 214 Bi on the sides of the detector. Data taken with the NEMO 2 prototype and an enriched molybdenum source foil indicates that the background limit reached is of the order of 1 event per year in the 3 MeV region. Results of this work have proven the necessity to have a magnetic field in NEMO 3 in order to reject e + - e - pairs. (author)

In vitro effects of beta-lactams combined with beta-lactamase inhibitors against methicillin-resistant Staphylococcus aureus.

Science.gov (United States)

Kobayashi, S; Arai, S; Hayashi, S; Sakaguchi, T

1989-01-01

The effects of combinations of beta-lactams with two beta-lactamase inhibitors, sulbactam and clavulanic acid, were determined in vitro against 22 clinical isolates of methicillin-resistant Staphylococcus aureus. Combinations of cefpirome, cefotaxime, and cefazolin with sulbactam (10 micrograms/ml) showed synergistic effects against more than 70% of the strains. Combinations of methicillin and penicillin G with sulbactam also showed synergistic effects against 50 and 68% of the strains, respectively, while cefotiam, moxalactam, flomoxef, and cefmetazole in combination with sulbactam showed such effects against only 40% or fewer. Clavulanic acid was synergistic only when combined with penicillin G, the effect probably being due to the beta-lactamase inhibition by the inhibitor. Sulbactam did not improve the antimicrobial activities of the beta-lactams against methicillin-susceptible S. aureus strains. At 42 degrees C the MICs of cefotaxime, methicillin, and flomoxef alone were markedly decreased from the values at 35 degrees C, and no synergy between these beta-lactams and sulbactam appeared. The resistance to penicillin G was not inhibited by incubation at 42 degrees C, and combinations of penicillin G with sulbactam and clavulanic acid showed synergy. The amounts of beta-lactamase produced were not related to the decreases in the MICs of the beta-lactams, except for penicillin G combined with sulbactam. Clavulanic acid showed slightly stronger beta-lactamase-inhibiting activity than sulbactam did. These results suggest that the synergy between sulbactam and the beta-lactams, except for penicillin G, may not be due to beta-lactamase inhibition but to suppression of the methicillin-resistant S. aureus-specific resistance based on other factors. PMID:2786369

Alpha and beta detection and spectrometry

International Nuclear Information System (INIS)

Saro, S.

1984-01-01

The theory of alpha and beta radioactive decay, the interaction of alpha and beta particles with matter, and their detection and spectrometry are dealt with in seven chapters: 1. Alpha transformation of atomic nuclei; 2. Basic properties of detectors and statistics of detection; 3. Alpha detectors and spectrometers; 4. Applications of alpha detection and spectrometry; 5. Beta transformation of atomic nuclei; 6. Beta particle detectors and spectrometers; 7. Detection of low energy beta particles. Chapter 8 is devoted to sampling and preparation of samples for radiometry. (E.F.)

The interaction of beta 2-microglobulin (beta 2m) with mouse class I major histocompatibility antigens and its ability to support peptide binding. A comparison of human and mouse beta 2m

DEFF Research Database (Denmark)

Pedersen, L O; Stryhn, A; Holter, T L

1995-01-01

of class I molecules are involved in peptide binding, whereas most of class I molecules are involved in beta 2m binding. We propose that mouse beta 2m interacts with the minor peptide binding (i.e. the "empty") fraction with a lower affinity than human beta 2m does, whereas mouse and human beta 2m interact......The function of major histocompatibility complex (MHC) class I molecules is to sample peptides derived from intracellular proteins and to present these peptides to CD8+ cytotoxic T lymphocytes. In this paper, biochemical assays addressing MHC class I binding of both peptide and beta 2-microglobulin...... (beta 2m) have been used to examine the assembly of the trimolecular MHC class I/beta 2m/peptide complex. Recombinant human beta 2m and mouse beta 2ma have been generated to compare the binding of the two beta 2m to mouse class I. It is frequently assumed that human beta 2m binds to mouse class I heavy...

Misleading Betas: An Educational Example

Science.gov (United States)

Chong, James; Halcoussis, Dennis; Phillips, G. Michael

2012-01-01

The dual-beta model is a generalization of the CAPM model. In the dual-beta model, separate beta estimates are provided for up-market and down-market days. This paper uses the historical "Anscombe quartet" results which illustrated how very different datasets can produce the same regression coefficients to motivate a discussion of the…

Multi-isotopic gamma-ray assay system for alpha-contaminated waste

International Nuclear Information System (INIS)

Close, D.A.; Pratt, J.C.; Caldwell, J.T.; Kunz, W.E.; Schultz, F.J.; Haff, K.W.

1983-01-01

The capability of an existing segmented gamma-ray system is being expanded for the analysis of alpha-contaminated waste drums. A cursory assay of 114 transuranic waste drums of 208-l capacity has been made. Analysis of these data indicates a detection limit better than 100 nCi/g of waste for 237 Np/ 233 Pa, 239 Pu, 241 Am, 243 Am/ 239 Np, 60 Co, 125 Sb, 134 137 Cs, and 154 Eu. A pending Code of Federal Regulation (10CFR61) stipulates that the nuclear industry quantify not only its transuranic waste, but also certain beta- and gamma-ray-emitting fission products. An assay system based on gamma-ray spectroscopy is the only system that can meet this requirement for the fission products

Beta-glucosidase variants and polynucleotides encoding same

Science.gov (United States)

Wogulis, Mark; Harris, Paul; Osborn, David

2017-06-27

The present invention relates to beta-glucosidase variants, e.g. beta-glucosidase variants of a parent Family GH3A beta-glucosidase from Aspergillus fumigatus. The present invention also relates to polynucleotides encoding the beta-glucosidase variants; nucleic acid constructs, vectors, and host cells comprising the polynucleotides; and methods of using the beta-glucosidase variants.

Characterization of the inclusion complex ropivacaine: {beta}-cyclodextrin; Caracterizacao do complexo de inclusso ropivacaina: {beta}-ciclodextrina

Energy Technology Data Exchange (ETDEWEB)

Fraceto, Leonardo Fernandes [Universidade Estadual Paulista Julio de Mesquita Filho, Sorocaba, SP (Brazil). Dept. de Engenharia Ambiental]. E-mail: leonardo@sorocaba.unesp.br; Goncalves, Marcos Moises [Universidade de Sorocaba, SP (Brazil); Moraes, Carolina Morales; Araujo, Daniele Ribeiro de; Zanella, Luciana; Paula, Eneida de [Universidade Estadual de Campinas (UNICAMP), Campinas, SP (Brazil). Inst. de Biologia. Dept. de Bioquimica; Pertinhez, Thelma de Aguiar [Universidade de Parma (Italy). Dept. de Medicina Experimental

2007-09-15

Ropivacaine (RVC) is a widely used local anesthetic. The complexation of RVC with {beta}-cyclodextrin ({beta}-CD) is of great interest for the development of more efficient local anesthetic formulations. The present work focuses on the characterization of the RVC:{beta}-CD complex by nuclear magnetic resonance (NMR). The stoichiometry of the complex is 1:2 RVC:{beta}-CD. DOSY-NMR shows that the association constant is 55.5 M{sup -1}. Longitudinal relaxation time results show that RVC changes its mobility in the presence of {beta}-CD. This study is focused on the physicochemical characterization of inclusion complexes that are potentials options for pain treatment. (author)

Determinations of silicon and phosphorus in rice planted on a district of high incidence of amyotrophic lateral sclerosis by neutron activation and X-ray fluorescence analyses

Energy Technology Data Exchange (ETDEWEB)

Mizumoto, Yoshihiko; Ishikawa, Teruumi; Kusakabe, Toshio; Katsurayama, Kousuke (Kinki Univ., Higashi-Osaka, Osaka (Japan)); Iwata, Shiro

1989-12-01

Silicon and phosphorus contents in polished and unpolished rice planted on a district of high incidence of amyotrophic lateral sclerosis (ALS) have been determined by neutron activation and X-ray fluorescence methods, and compared with those from control areas. In the neutron activation analysis, {beta}-ray spectra of {sup 32}P produced by the {sup 31}P(n, {gamma}){sup 32}P reaction on polished and unpolished rice were measured with a low background {beta}-ray spectrometer. In the X-ray fluorescence analysis, characteristic X-ray were analyzed with a wavelength dispersive X-ray fluorescence spectrometer. Silicon contents in polished and unpolished rice from the ALS area are 42 {mu}g.g{sup -1} and 370 {mu}g.g{sup -1}, respectively, and the corresponding phosphorus contents are 1210 {mu}g.g{sup -1}, and 3370 {mu}g.g{sup -1}, respectively. The data for ALS area are equal to those for the control area within atandard deviation. (author).

The diagnosis of the gastric cancer using catheter-type semiconductor radiation detector. Comparison of diagnostic values of. beta. -emitting radionuclide label with. gamma. -emitting label

Energy Technology Data Exchange (ETDEWEB)

Sassa, R; Iwase, T [Asahi Life Foundation, Tokyo (Japan). Inst. for Adult Diseases; Sugita, T; Iio, M

1975-06-01

The diagnostic usefulness of /sup 32/P-phosphate for human gastric cancer, using a catheter-type semiconductor radiation detector (CASRAD) combined with gastrofiberscope technique, has already been reported by the authors. They have in addition used sup(99m)Tc-bleomycin, sup(99m)Tc-tetracycline in the diagnosis of experimental rabbit gastric cancer, too. In the present study, further refinement of the technique for the ..beta..-ray labeled substance (/sup 32/P-phosphate) for detection of the gastric cancer was compared with that of ..gamma..-ray labeled substance (sup(99m)Tc-tetracycline). A more correct diagnosis of the gastric cancer by in vivo measurement of beta activity could be obtained, when the collimater, made of stainless steel, was attached to the top of the detector. In this way contribution to the count from the adjacent tissues or organs could be eliminated. They were unable to produce an effective and useful collimater for ..gamma..-ray labeled substance which could to be used safely in vivo. Because of the unsatisfactory collimater, radioactivities of the adjacent organs caused on increase in the radioactivity of the background. Therefore inspite of the recent introduction of various sup(99m)Tc-tumor agents, these labels were not applicable to the CASRAD method. For such a small detector system, ..beta..-labels, represented by /sup 32/P-phosphate, was still prefererable to ..gamma..-labels.

Synthesis of 5/7-, 5/8- and 5/9-bicyclic lactam templates as constraints for external beta-turns.

Science.gov (United States)

Duggan, Heather M E; Hitchcock, Peter B; Young, Douglas W

2005-06-21

The 5/7-, 5/8- and 5/9-bicyclic lactams 3, 17, 5 and 6 have been synthesised as single diastereoisomers by a route involving ring closing olefin metathesis. The X-ray crystal structure of the amino acid hydrochloride has been carried out and compared to that of the saturated external beta-turn constraint 18.

Activities of beta-lactam antibiotics against Escherichia coli strains producing extended-spectrum beta-lactamases.

Science.gov (United States)

Jacoby, G A; Carreras, I

1990-01-01

Seven extended-spectrum beta-lactamases related to TEM and four enzymes derived from SHV-1 were transferred to a common Escherichia coli host so that the activity of a variety of beta-lactams could be tested in a uniform genetic environment. For most derivatives, penicillinase activity was 10% or less than that of strains making TEM-1, TEM-2, or SHV-1 beta-lactamase, suggesting that reduced catalytic efficiency accompanied the broader substrate spectrum. Despite this deficit, resistance to aztreonam, carumonam, cefdinir, cefepime, cefixime, cefmenoxime, cefotaxime, cefotiam, cefpirome, cefpodoxime, ceftazidime, ceftibuten, ceftizoxime, ceftriaxone, cefuroxime, and E1040 was enhanced. For strains producing TEM-type enzymes, however, MICs of carumonam, cefepime, cefmenoxime, cefotiam, cefpirome, and ceftibuten were 8 micrograms/ml or less. Susceptibilities of cefmetazole, cefotetan, cefoxitin, flomoxef, imipenem, meropenem, moxalactam, temocillin, FCE 22101, and Sch 34343 were unaffected. FCE 22101, imipenem, meropenem, and Sch 34343 were inhibitory for all strains at 1 microgram/ml or less. In E. coli an OmpF- porin mutation in combination with an extended-spectrum beta-lactamase enhanced resistance to many of these agents, but generally by only fourfold. Hyperproduction of chromosomal AmpC beta-lactamase increased resistance to 7-alpha-methoxy beta-lactams but not that to temocillin. When tested at 8 micrograms/ml, clavulanate was more potent than sulbactam or tazobactam in overcoming resistance to ampicillin, while cefoperazone-sulbactam was more active than ticarcillin-clavulanate or piperacillin-tazobactam, especially against TEM-type extended-spectrum beta-lactamases. PMID:2193623

TGF-{beta}-stimulated aberrant expression of class III {beta}-tubulin via the ERK signaling pathway in cultured retinal pigment epithelial cells

Energy Technology Data Exchange (ETDEWEB)

Chung, Eun Jee [Department of Ophthalmology, National Health Insurance Corporation Ilsan Hospital, Gyeonggi-do (Korea, Republic of); Chun, Ji Na; Jung, Sun-Ah [Konyang University Myunggok Medical Research Institute, Kim' s Eye Hospital, Konyang University College of Medicine, Seoul (Korea, Republic of); Cho, Jin Won [Department of Biology, Yonsei University, 134 Shinchon-dong, Seodaemun-gu, Seoul 120-749 (Korea, Republic of); Lee, Joon H., E-mail: joonhlee@konyang.ac.kr [Konyang University Myunggok Medical Research Institute, Kim' s Eye Hospital, Konyang University College of Medicine, Seoul (Korea, Republic of)

2011-11-18

Highlights: Black-Right-Pointing-Pointer TGF-{beta} induces aberrant expression of {beta}III in RPE cells via the ERK pathway. Black-Right-Pointing-Pointer TGF-{beta} increases O-GlcNAc modification of {beta}III in RPE cells. Black-Right-Pointing-Pointer Mature RPE cells have the capacity to express a neuron-associated gene by TGF-{beta}. -- Abstract: The class III {beta}-tubulin isotype ({beta}{sub III}) is expressed exclusively by neurons within the normal human retina and is not present in normal retinal pigment epithelial (RPE) cells in situ or in the early phase of primary cultures. However, aberrant expression of class III {beta}-tubulin has been observed in passaged RPE cells and RPE cells with dedifferentiated morphology in pathologic epiretinal membranes from idiopathic macular pucker, proliferative vitreoretinopathy (PVR) and proliferative diabetic retinopathy (PDR). Transforming growth factor-{beta} (TGF-{beta}) has been implicated in dedifferentiation of RPE cells and has a critical role in the development of proliferative vitreoretinal diseases. Here, we investigated the potential effects of TGF-{beta} on the aberrant expression of class III {beta}-tubulin and the intracellular signaling pathway mediating these changes. TGF-{beta}-induced aberrant expression and O-linked-{beta}-N-acetylglucosamine (O-GlcNac) modification of class III {beta}-tubulin in cultured RPE cells as determined using Western blotting, RT-PCR and immunocytochemistry. TGF-{beta} also stimulated phosphorylation of ERK. TGF-{beta}-induced aberrant expression of class III {beta}-tubulin was significantly reduced by pretreatment with U0126, an inhibitor of ERK phosphorylation. Our findings indicate that TGF-{beta} stimulated aberrant expression of class III {beta}-tubulin via activation of the ERK signaling pathway. These data demonstrate that mature RPE cells have the capacity to express a neuron-associated gene in response to TGF-{beta} stimulation and provide useful information

Respiration and phosphorylation in liver and kidney mitochondria of rats exposed to high-energy gamma and beta radiation

Energy Technology Data Exchange (ETDEWEB)

Mokhoreva, S I; Vetlugina, N S

1973-01-01

The effect of whole-body irradiation with ..gamma.. rays (radiation source /sup 60/Co) at 40 rad and ..beta.. rays (source, a linear accelerator, electron energy 25 MeV) at 43 rad on oxidative phosphorylation in liver and kidney mitochondria was studied in rats. Gamma radiation gradually slowed the esterification of phosphate and respiratory rate during the oxidation of succinate in the liver and kidney mitochondria. The decrease was largest on day 15 after irradiation. However, the P/O ratio did not decrease by more than 10 to 12 percent. Despite the oxidation of glutamate in the mitochondria, respiration, phosphate consumption, and P/O ratio scarcely changed. Irradiation with electrons slowed the rate of oxidation of succinate and glutamate in liver mitochondria within 3 to 7 days. Phosphate consumption decreased at the same time so that the P/O ratio remained unchanged. Beta irradiation had virtually no effect on liver mitochondria. There is a discussion of the mechanism of action of high-energy radiation on the phosphorylation system of the mitochondria.

Photovoltaic Performance of ZnO Nanosheets Solar Cell Sensitized with Beta-Substituted Porphyrin

Directory of Open Access Journals (Sweden)

Arumugam Mahesh

2011-01-01

Full Text Available The photoanode of dye-sensitized solar cell (DSSC was fabricated using two-dimensional ZnO nanosheets (2D ZnO NSs sensitized with beta-substituted porphyrins photosensitizer, and its photovoltaic performance in solid-state DSSC with TiO2 nanotubes (TiO2 TNs modified poly (ethylene oxide (PEO polymer electrolyte was studied. The ZnO NSs were synthesized through hydrothermal method and were characterized through high-resolution scanning electron microscopy (HRSEM, diffused reflectance spectra (DRS, photoluminescence spectra (PL, and X-ray diffraction (XRD analysis. The crystallinity of the polymer electrolytes was investigated using X-ray diffraction analysis. The photovoltaic performance of the beta-substituted porphyrins sensitized solar cells was evaluated under standard AM1.5G simulated illumination (100 mW cm−2. The efficiency of energy conversion from solar to electrical due to 2D ZnO NSs based DSSCs is 0.13%, which is about 1.6 times higher than that of the control DSSC using ZnO nanoparticles (ZnO NPs as photoanode (0.08%, when TiO2 NTs fillers modified PEO electrolyte was incorporated in the DSSCs. The current-voltage (- and photocurrent-time (- curves proved stable with effective collection of electrons, when the 2D ZnO nanostructured photoanode was introduced in the solid-state DSSC.

Milk Intolerance, Beta-Casein and Lactose.

Science.gov (United States)

Pal, Sebely; Woodford, Keith; Kukuljan, Sonja; Ho, Suleen

2015-08-31

True lactose intolerance (symptoms stemming from lactose malabsorption) is less common than is widely perceived, and should be viewed as just one potential cause of cows' milk intolerance. There is increasing evidence that A1 beta-casein, a protein produced by a major proportion of European-origin cattle but not purebred Asian or African cattle, is also associated with cows' milk intolerance. In humans, digestion of bovine A1 beta-casein, but not the alternative A2 beta-casein, releases beta-casomorphin-7, which activates μ-opioid receptors expressed throughout the gastrointestinal tract and body. Studies in rodents show that milk containing A1 beta-casein significantly increases gastrointestinal transit time, production of dipeptidyl peptidase-4 and the inflammatory marker myeloperoxidase compared with milk containing A2 beta-casein. Co-administration of the opioid receptor antagonist naloxone blocks the myeloperoxidase and gastrointestinal motility effects, indicating opioid signaling pathway involvement. In humans, a double-blind, randomized cross-over study showed that participants consuming A1 beta-casein type cows' milk experienced statistically significantly higher Bristol stool values compared with those receiving A2 beta-casein milk. Additionally, a statistically significant positive association between abdominal pain and stool consistency was observed when participants consumed the A1 but not the A2 diet. Further studies of the role of A1 beta-casein in milk intolerance are needed.

Milk Intolerance, Beta-Casein and Lactose

Directory of Open Access Journals (Sweden)

Sebely Pal

2015-08-01

Full Text Available True lactose intolerance (symptoms stemming from lactose malabsorption is less common than is widely perceived, and should be viewed as just one potential cause of cows’ milk intolerance. There is increasing evidence that A1 beta-casein, a protein produced by a major proportion of European-origin cattle but not purebred Asian or African cattle, is also associated with cows’ milk intolerance. In humans, digestion of bovine A1 beta-casein, but not the alternative A2 beta-casein, releases beta-casomorphin-7, which activates μ-opioid receptors expressed throughout the gastrointestinal tract and body. Studies in rodents show that milk containing A1 beta-casein significantly increases gastrointestinal transit time, production of dipeptidyl peptidase-4 and the inflammatory marker myeloperoxidase compared with milk containing A2 beta-casein. Co-administration of the opioid receptor antagonist naloxone blocks the myeloperoxidase and gastrointestinal motility effects, indicating opioid signaling pathway involvement. In humans, a double-blind, randomized cross-over study showed that participants consuming A1 beta-casein type cows’ milk experienced statistically significantly higher Bristol stool values compared with those receiving A2 beta-casein milk. Additionally, a statistically significant positive association between abdominal pain and stool consistency was observed when participants consumed the A1 but not the A2 diet. Further studies of the role of A1 beta-casein in milk intolerance are needed.

Gamma-spectrometric and total alpha-beta counting methods for radioactivity analysis of deuterium depleted water

International Nuclear Information System (INIS)

Ferdes, Ov. S.; Mladin, C.; Vladu, Mihaela; Bulubasa, G.; Bidica, N.

2008-01-01

According to national regulations, as well as to the EU directive on the quality of drinking water, the radionuclide concentrations represent some of the drinking water quality parameters. Among the most important radioactivity content parameters are: the total alpha and total beta concentration (Bq/l); K-40 content, and the gamma-nuclides volume activities. The paper presents the measuring methods for low-level total alpha and/or beta counting of volume samples, as well as the high-resolution gamma-ray spectrometric method used to measure the volume activity of nuclides in drinking water. These methods are applied to monitor the radioactivity content and quality of the QLARIVIA brand of Deuterium depleted water (DDW). There are discussed the performances of these applied methods as well as some preliminary results. (authors)

Beta-decay study of T{sub z}=-2 proton-rich nucleus {sup 24}Si

Energy Technology Data Exchange (ETDEWEB)

Ichikawa, Y.; Iwasaki, H.; Nakao, T.; Ong, H.J.; Onishi, T.K.; Suzuki, D.; Suzuki, H.; Suzuki, M.K. [University of Tokyo, Department of Physics, Tokyo (Japan); Kubo, T.; Aoi, N.; Fukuda, N.; Motobayashi, T.; Yamada, K.N.; Sakurai, H. [RIKEN, RIKEN Nishina Center, Saitama (Japan); Banerjee, V.; Chakrabarti, A. [Variable Energy Cyclotron Centre, Kolkata (India); Kubono, S.; Yamaguchi, H. [University of Tokyo, Center for Nuclear Study, Tokyo (Japan); Nakabayashi, T.; Nakamura, T.; Okumura, T. [Tokyo Institute of Technology, Department of Physics, Tokyo (Japan); Teranishi, T. [Kyushu University, Department of Physics, Fukuoka (Japan)

2009-12-15

{beta} -decay spectroscopy on a T{sub z}=-2 proton-rich nucleus {sup 24}Si was performed. The decay scheme of {sup 24}Si was reconstructed by the {beta} -delayed {gamma} -ray and proton measurements. Two {beta} branches to the bound 1{sub 1}{sup +} and 1{sub 2}{sup +} states in {sup 24}Al were observed for the first time. The observation of the allowed transition firmly established the spin-parity assignment for the 1{sub 2}{sup +} states. The branching ratios to the 1{sub 1}{sup +} and 1{sub 2}{sup +} states were determined to be 31(4)% and 23.9(15)%, respectively. The branching ratios to three unbound states in {sup 24}Al including a new level at 6.735MeV were also determined for the first time. The level structure of {sup 24}Al was compared with its mirror nucleus {sup 24}Na. The Thomas-Ehrman shift on the 1{sub 2}{sup +} state indicates s -wave dominance in the state as well as a characteristic behavior of the weakly bound s-wave proton in {sup 24}Al. (orig.)

Cross-class resistance to non-beta-lactam antimicrobials in extended-spectrum beta-lactamase-producing Klebsiella pneumoniae.

Science.gov (United States)

Procop, Gary W; Tuohy, Marion J; Wilson, Deborah A; Williams, Delisa; Hadziyannis, Emilia; Hall, Gerri S

2003-08-01

Extended spectrum beta-lactamases are modified beta-lactamase enzymes that impart resistance to third-generation cephalosporins and make all beta-lactam antibiotics and cephalosporins useless for therapy. We compared the antimicrobial susceptibility profiles of extended-spectrum beta-lactamase (ESBL)-producing and non-ESBL-producing isolates of Klebsiella pneumoniae. The ESBL producers had significantly diminished susceptibility compared with the non-ESBL producers for gentamicin (P < .001), tobramycin (P < .001), amikacin (P < .005), trimethoprim-sulfamethoxazole (P < .01), ciprofloxacin (P < .001), and nitrofurantoin (P < .001). All isolates were susceptible to imipenem. ESBL-producing K pneumoniae may also be resistant to non-beta-lactam antibiotics. Therefore, susceptibility testing of these isolates is critical for guiding therapy.

Dosimetry of {beta} extensive sources; Dosimetria de fuentes {beta} extensas

Energy Technology Data Exchange (ETDEWEB)

Rojas C, E.L.; Lallena R, A.M. [Departamento de Fisica Moderna, Universidad de Granada, E-18071 Granada (Spain)

2002-07-01

In this work, we have been studied, making use of the Penelope Monte Carlo simulation code, the dosimetry of {beta} extensive sources in situations of spherical geometry including interfaces. These configurations are of interest in the treatment of the called cranealfaringyomes of some synovia leisure of knee and other problems of interest in medical physics. Therefore, its application can be extended toward problems of another areas with similar geometric situation and beta sources. (Author)

Beta-1-Selective Beta-Blockers and Cognitive Functions in Patients With Coronary Artery Disease: A Cross-Sectional Study.

Science.gov (United States)

Burkauskas, Julius; Noreikaite, Aurelija; Bunevicius, Adomas; Brozaitiene, Julija; Neverauskas, Julius; Mickuviene, Narseta; Bunevicius, Robertas

2016-01-01

The association between current beta-1-selective beta-blocker use and cognitive function was evaluated in 722 patients with coronary artery disease without dementia. Beta-1-selective beta-blocker use was associated with worse incidental learning independently of sociodemographic characteristics, clinical coronary artery disease severity, and depression/anxiety.

The 76Ge(n,p)76Ga reaction and its relevance to searches for the neutrino-less double-beta decay of 76Ge

Science.gov (United States)

Tornow, W.; Bhike, Megha; Fallin, B.; Krishichayan, Fnu

2015-10-01

The 76Ge(n,p)76Ga reaction and the subsequent β decay of 76Ga to 76Ge has been used to excite the 3951.9 keV state of 76Ge, which decays by emission of a 2040.7 keV γ ray. Using HPGe detectors, the associated pulse-height signal may be undistinguishable from the potential signal produced in neutrino-less double-beta decay of 76Ge with its Q-value of 2039.0 keV. In the neutron energy range between 10 and 20 MeV the production cross section of the 2040.7 keV γ ray is approximately 0.1 mb. In the same experiment γ rays of energy 2037.9 keV resulting from the 76Ge(n, γ)77Ge reaction were clearly observed. Adding the 76Ge(n,n' γ)76Ge reaction, which also produces the 2040.7 keV γ ray with a cross section value of the order of 0.1 mb clearly shows that great care has to be taken to eliminate neutron-induced backgrounds in searches for neutrino-less double-beta decay of 76Ge. This work was supported by the U.S. DOE under Grant NO. DE-FG02-97ER41033.

Superconducting tests of beta = 0.1 and beta = 0.2 resonators

International Nuclear Information System (INIS)

Storm, D.W.; Amsbaugh, J.F.; Corcoran, D.T.; Howe, M.A.

1985-01-01

Several low beta (0.10) and two high beta (0.21) lead plated copper quarter wave resonators were cooled down, multipactor conditioned, tested, helium conditioned, and retested. The choice of the quarter wave resonator and of the lead plated copper technology is discussed. The fabrication is described and techniques for conditioning the resonators are presented. Performances are presented. 5 refs., 4 figs

Calculation of reasonable exemption levels for surface contamination by measuring overall gamma ray

International Nuclear Information System (INIS)

Ogino, Haruyuki; Hattori, Takatoshi

2008-01-01

The present regulation on surface contamination [Bq/cm 2 ] is determined from a simple radiological model for the most hazardous radionuclides (Pu-239 for alpha emitters and Sr-90 for beta emitters) and its extremely conservative model is applied for all other alpha and beta emitters. In this study, reasonable exemption levels for surface contamination are calculated for each radionuclide by adopting an original radiological dose evaluation method for surface contamination that can be applied in radiation safety, transport safety and waste safety. Furthermore, a new concept of judging the exemption by estimating the overall contamination [Bq] on the objects from the measurement of gamma ray has been designed and a reasonable value was derived. We conclude that the overall exemption levels obtained by gamma ray measurement can be one order smaller than those obtained by the conventional method for some radionuclides, such as Mn-54, Co-60, Nb-94, Cs-134, Cs-137, Eu-152 and Eu-154. (author)

Double beta radioactivity and physics of the neutrino. Study of the background noise at 3 MeV in the search of {sup 100}Mo beta beta decay; Double radioactivite beta et physique du neutrino. Etude du bruit de fond a 3 MeV dans la recherche de la desintegration beta beta du {sup 100}Mo

Energy Technology Data Exchange (ETDEWEB)

Piquemal, F

1994-05-01

Double beta decay without neutrino emission provides a test of the mass and nature of neutrinos (Majorana or Dirac). Experimental proof would be the observation of a peak at the transition energy in the spectrum of the two emitted electrons. The expected half-life of the process is extremely long (about 10{sup 25} years for {sup 100}Mo). So, being thus, it is very important to get a good knowledge of the origins and contributions of background noise in the region where the signal could occur. The main origins of the background noise in the region where the signal could occur. The main origins of the background noise are found to be e{sup +} - e{sup -} pairs induced by heavy energy gamma rays. These gamma rays follow the thermal neutron capture by the components of the detector. Another factor in the production of background noise is natural radio-activity. For example, the presence of Radon in the laboratory has been observed to produce deposits of {sup 214}Bi on the sides of the detector. Data taken with the NEMO 2 prototype and an enriched molybdenum source foil indicates that the background limit reached is of the order of 1 event per year in the 3 MeV region. Results of this work have proven the necessity to have a magnetic field in NEMO 3 in order to reject e{sup +} - e{sup -}pairs. (author).

Characterization of beta-turn and Asx-turns mimicry in a model peptide: stabilization via C--H . . . O interaction.

Science.gov (United States)

Thakur, A K; Kishore, R

2006-04-15

The chemical synthesis and single-crystal X-ray diffraction analysis of a model peptide, Boc-Thr-Thr-NH2 (1) comprised of proteinogenic residues bearing an amphiphilic Cbeta -stereogenic center, has been described. Interestingly, the analysis of its molecular structure revealed the existence of a distinct conformation that mimics a typical beta-turn and Asx-turns, i.e., the two Thr residues occupy the left- and right-corner positions. The main-chain torsion angles of the N- and C-terminal residues i.e., semiextended: phi = -68.9 degrees , psi = 128.6 degrees ; semifolded: phi = -138.1 degrees , psi = 2.5 degrees conformations, respectively, in conjunction with a gauche- disposition of the obligatory C-terminus Thr CgammaH3 group, characterize the occurrence of the newly described beta-turn- and Asx-turns-like topology. The preferred molecular structure is suggested to be stabilized by an effective nonconventional main-chain to side-chain Ci=O . . . H--Cgamma(i+2)-type intraturn hydrogen bond. Noteworthy, the observed topology of the resulting 10-membered hydrogen-bonded ring is essentially similar to the one perceived for a classical beta-turn and the Asx-turns, stabilized by a conventional intraturn hydrogen bond. Considering the signs as well as magnitudes of the backbone torsion angles and the orientation of the central peptide bond, the overall mimicked topology resembles the type II beta-turn or type II Asx-turns. An analysis of Xaa-Thr sequences in high-resolution X-ray elucidated protein structures revealed the novel topology prevalence in functional proteins (unpublished). In view of indubitable structural as well as functional importance of nonconventional interactions in bioorganic and biomacromolecules, we intend to highlight the participation of Thr CgammaH in the creation of a short-range C=O . . . H--Cgamma -type interaction in peptides and proteins. Copyright 2006 Wiley Periodicals, Inc.

BETA SPECTRA. I. Negatrons spectra; ESPECTROS BETA. I. Espectros simples de negatrones

Energy Technology Data Exchange (ETDEWEB)

Grau Malonda, A; Garcia-Torano, E

1978-07-01

Using the Fermi theory of beta decay, the beta spectra for 62 negatrons emitters have been computed introducing a correction factor for unique forbidden transitions. These spectra are plotted vs. energy, once normal i sed, and tabulated with the related Fermi functions. The average and median energies are calculated. (Author)

In vitro proliferation of adult human beta-cells.

Directory of Open Access Journals (Sweden)

Sabine Rutti

Full Text Available A decrease in functional beta-cell mass is a key feature of type 2 diabetes. Glucagon-like peptide 1 (GLP-1 analogues induce proliferation of rodent beta-cells. However, the proliferative capacity of human beta-cells and its modulation by GLP-1 analogues remain to be fully investigated. We therefore sought to quantify adult human beta-cell proliferation in vitro and whether this is affected by the GLP-1 analogue liraglutide.Human islets from 7 adult cadaveric organ donors were dispersed into single cells. Beta-cells were purified by FACS. Non-sorted cells and the beta-cell enriched ("beta-cells" population were plated on extracellular matrix from rat (804G and human bladder carcinoma cells (HTB9 or bovine corneal endothelial ECM (BCEC. Cells were maintained in culture+/-liraglutide for 4 days in the presence of BrdU.Rare human beta-cell proliferation could be observed either in the purified beta-cell population (0.051±0.020%; 22 beta-cells proliferating out of 84'283 beta-cells counted or in the non-sorted cell population (0.055±0.011%; 104 proliferating beta-cells out of 232'826 beta-cells counted, independently of the matrix or the culture conditions. Liraglutide increased human beta-cell proliferation on BCEC in the non-sorted cell population (0.082±0.034% proliferating beta-cells vs. 0.017±0.008% in control, p<0.05.These results indicate that adult human beta-cell proliferation can occur in vitro but remains an extremely rare event with these donors and particular culture conditions. Liraglutide increases beta-cell proliferation only in the non-sorted cell population and only on BCEC. However, it cannot be excluded that human beta-cells may proliferate to a greater extent in situ in response to natural stimuli.

Beta-Catenin Stability in Breast Cancer

National Research Council Canada - National Science Library

Baswaran, Vijay

1999-01-01

.... beta-catenin also binds the adenomatous polyposis coli protein (APC). The tumor suppressor function of APC is suggested to depend in part on its ability to bind beta-catenin and to facilitate beta-catenin degradation by an unknown mechanism...

Sequence-specific unusual (1-->2)-type helical turns in alpha/beta-hybrid peptides.

Science.gov (United States)

Prabhakaran, Panchami; Kale, Sangram S; Puranik, Vedavati G; Rajamohanan, P R; Chetina, Olga; Howard, Judith A K; Hofmann, Hans-Jörg; Sanjayan, Gangadhar J

2008-12-31

This article describes novel conformationally ordered alpha/beta-hybrid peptides consisting of repeating l-proline-anthranilic acid building blocks. These oligomers adopt a compact, right-handed helical architecture determined by the intrinsic conformational preferences of the individual amino acid residues. The striking feature of these oligomers is their ability to display an unusual periodic pseudo beta-turn network of nine-membered hydrogen-bonded rings formed in the forward direction of the sequence by 1-->2 amino acid interactions both in solid-state and in solution. Conformational investigations of several of these oligomers by single-crystal X-ray diffraction, solution-state NMR, and ab initio MO theory suggest that the characteristic steric and dihedral angle restraints exerted by proline are essential for stabilizing the unusual pseudo beta-turn network found in these oligomers. Replacing proline by the conformationally flexible analogue alanine (Ala) or by the conformationally more constrained alpha-amino isobutyric acid (Aib) had an adverse effect on the stabilization of this structural architecture. These findings increase the potential to design novel secondary structure elements profiting from the steric and dihedral angle constraints of the amino acid constituents and help to augment the conformational space available for synthetic oligomer design with diverse backbone structures.

Application of Electron Bernstein Wave heating and current drive to high beta plasmas

International Nuclear Information System (INIS)

Efthimion, P.C.

2002-01-01

Electron Bernstein Waves (EBW) can potentially heat and drive current in high-beta plasmas. Electromagnetic waves can convert to EBW via two paths. O-mode heating, demonstrated on W-7AS, requires waves be launched within a narrow k-parallel range. Alternately, in high-beta plasmas, the X-mode cutoff and EBW conversion layers are millimeters apart, so the fast X-mode can tunnel to the EBW branch. We are studying the conversion of EBW to the X-mode by measuring the radiation temperature of the cyclotron emission and comparing it to the electron temperature. In addition, mode conversion has been studied with an approximate kinetic full-wave code. We have enhanced EBW mode conversion to ∼ 100% by encircling the antenna with a limiter that shortens the density scale length at the conversion layer in the scrape off of the CDX-U spherical torus (ST) plasma. Consequently, a limiter in front of a launch antenna achieves efficient X-mode coupling to EBW. Ray tracing and Fokker-Planck codes have been used to develop current drive scenarios in NSTX high-beta (∼ 40%) ST plasmas and a relativistic code will examine the potential synergy of EBW current drive with the bootstrap current. (author)

Study of the irradiation effects on thorium phosphate diphosphate ({beta}-TPD): consequences on its chemical durability; Etude des effets d'irradiation sur le phosphate diphosphate de thorium ({beta}-PDT): consequences sur la durabilite chimique

Energy Technology Data Exchange (ETDEWEB)

Tamain, C

2005-12-15

Since Thorium Phosphate Diphosphate (beta-TPD) can be considered as a potential host matrix for long-term storage in underground repository, it is necessary to study the irradiation effects on the structure of this ceramics and the consequences on its chemical durability. Sintered samples of beta-TPD and of associated solid solutions of beta-TUPD were irradiated under ion beams and then altered in aqueous solutions. Depending on the electronic LET value, beta-TPD can be completely or partly amorphized. Furthermore, the ability of recrystallization of the amorphous material by thermal annealing was also demonstrated. Some leaching tests, realized on these irradiated samples, have shown a significant effect of the amorphous fraction on the normalized dissolution rate which was increased by a factor of 10 from the crystallized to the fully amorphized material. Correlatively, the amorphous fraction also modified the delay to reach the saturation conditions associated to the thermodynamic equilibria involved. On the other hand, it exhibited no influence neither on other kinetic parameters, such as activation energy of the dissolution process or partial order related to the proton concentration, nor on the nature of the neo-formed phase formed at the saturation of the leachate and identified as Thorium Phosphate Hydrogeno-Phosphate Hydrate (TPHPH). Beta-TUPD samples were also irradiated by gamma and alpha rays during leaching tests to study the effects of radiolysis in the leaching medium on the normalized leaching rate. It appeared that the radiolytic species occurring in the dissolution mechanism were unstable, disappearing quickly when stopping the irradiation. (author)

Preliminary Results of Nuclear Fluorescence Imaging of Alpha and Beta Emitting Sources

International Nuclear Information System (INIS)

Feener, Jessica S.; Charlton, William S.

2013-06-01

The preliminary results from a series of nuclear fluorescence imaging experiments using a variety of radioactive sources and shielding are given. These experiments were done as part of a proof of concept to determine if nuclear fluorescence imaging could be used as a safeguards measurements tool or for nuclear warhead verification for nuclear arms control treaties such as the New Strategic Arms Reduction Treaty and the Fissile Material Cut-Off Treaty. An off-the-shelf Princeton Instruments charged coupled device camera system was used to image the emission of fluorescence photons from the de-excitation of nitrogen molecules in air that have been excited by ionizing radiation. The fluorescence emissions are primarily in the near ultraviolet range; between the wavelengths of 300 and 400 nm. Fluorescent imaging techniques are currently being investigated in a number of applications. A French research team has successfully demonstrated this concept for remote imaging of alpha contamination. It has also been shown that the phenomenon can be seen through translucent materials and that alpha radiation can be seen in the presence of large gamma backgrounds. Additionally, fluorescence telescopes and satellites utilize the de-excitation of nitrogen molecules to observe cosmic ray showers in the atmosphere. In cosmic ray shower detection, electrons are the main contributor to the excitation of the of nitrogen molecules in air. The experiments presented in this paper were designed to determine if the imaging system could observe beta emitting sources, differentiate between beta emitters and alpha emitting materials such as uranium oxide and uranium metal, and to further investigate the phenomenon through translucent and non-translucent materials. The initial results show that differentiation can be made between beta and alpha emitting sources and that the device can observe the phenomenon through very thin non-transparent material. Additionally, information is given on the

Study and construction of a {beta}-spectrometer of uniform axial magnetic field fitted with a {beta}-{gamma} coincidence selector. Study of the {beta} spectra of {sup 32}P, {sup 203}Hg, {sup 198}Au. Measurement of the conversion coefficients of {sup 203}Ti and of {sup 198}Hg; Etude et realisation d'un spectrometre-{beta} a champ magnetique axial uniforme, muni d'un selecteur de coincidence {beta}-{gamma}. Etude des spectres {beta} du {sup 32}p, {sup 203}Hg, {sup 198}Au. Mesure des coefficients de conversion du {sup 203}Ti et du {sup 198}Hg

Energy Technology Data Exchange (ETDEWEB)

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

1964-06-01

In the first part is given the principle of the beta spectrometer with uniform axial field using systematically the idea of caustics. The apparatus is described and its properties compared to those deduced from trajectory calculations. The {beta}-ray and {gamma}-ray detectors and the device for selecting coincidences with a 2 {tau} resolution of 5 nanoseconds are also presented. In the second part, the spectrometer is used for studying reference elements and the most accurate results are confirmed. The {beta} spectrum of {sup 60}Co has a statistical form with an accuracy of 1 per cent; the maximum energy E{sub 0} is 316.5 {+-} 1.5 keV. That of the 7/2 + {yields} 11/2 transition for {sup 137}Cs has a unique form, once forbidden. E{sub 0}= 522 {+-} 3 keV. Conversion coefficients {alpha}{sub k} = 96 {+-} 1 X 10{sup -3} {alpha}L + M + N = 20.9 {+-} 0.5 X 10{sup -3}. The two {beta} spectra of {sup 59}Fe, separated by coincidence with the gamma, have the statistical form E{sub 0} = 462 {+-} 2 keV (55.1 + 0,3 per cent) and E{sub 1} = 275 {+-} 4 keV (44.9 {+-} 0.3 per cent). It is then verified whether the l selection rule is apparent in the shape of the phosphorus 32 beta spectrum. It is found in fact that it is not of statistical shape and its shape coefficient is determined. For a theoretical interpretation it is necessary to have better approximations than those generally used and this interpretation will not be unique. This work has also made it possible to show that the source contains a small proportion of {sup 33}P. The study of the {sup 203}Hg {beta} spectrum followed by the 279 keV gamma spectrum is designed to determine the conversion coefficients. The interior spectrum of gold 198 is not of statistical shape either. The form coefficient is determined together with the conversion coefficients which are in slight disagreement with those calculated by Rose or Sliv. An interpretation of the spectrum is put forward which proposes an imperfect compensation for the

Study and construction of a {beta}-spectrometer of uniform axial magnetic field fitted with a {beta}-{gamma} coincidence selector. Study of the {beta} spectra of {sup 32}P, {sup 203}Hg, {sup 198}Au. Measurement of the conversion coefficients of {sup 203}Ti and of {sup 198}Hg; Etude et realisation d'un spectrometre-{beta} a champ magnetique axial uniforme, muni d'un selecteur de coincidence {beta}-{gamma}. Etude des spectres {beta} du {sup 32}p, {sup 203}Hg, {sup 198}Au. Mesure des coefficients de conversion du {sup 203}Ti et du {sup 198}Hg

Energy Technology Data Exchange (ETDEWEB)

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

1964-06-01

In the first part is given the principle of the beta spectrometer with uniform axial field using systematically the idea of caustics. The apparatus is described and its properties compared to those deduced from trajectory calculations. The {beta}-ray and {gamma}-ray detectors and the device for selecting coincidences with a 2 {tau} resolution of 5 nanoseconds are also presented. In the second part, the spectrometer is used for studying reference elements and the most accurate results are confirmed. The {beta} spectrum of {sup 60}Co has a statistical form with an accuracy of 1 per cent; the maximum energy E{sub 0} is 316.5 {+-} 1.5 keV. That of the 7/2 + {yields} 11/2 transition for {sup 137}Cs has a unique form, once forbidden. E{sub 0}= 522 {+-} 3 keV. Conversion coefficients {alpha}{sub k} = 96 {+-} 1 X 10{sup -3} {alpha}L + M + N = 20.9 {+-} 0.5 X 10{sup -3}. The two {beta} spectra of {sup 59}Fe, separated by coincidence with the gamma, have the statistical form E{sub 0} = 462 {+-} 2 keV (55.1 + 0,3 per cent) and E{sub 1} = 275 {+-} 4 keV (44.9 {+-} 0.3 per cent). It is then verified whether the l selection rule is apparent in the shape of the phosphorus 32 beta spectrum. It is found in fact that it is not of statistical shape and its shape coefficient is determined. For a theoretical interpretation it is necessary to have better approximations than those generally used and this interpretation will not be unique. This work has also made it possible to show that the source contains a small proportion of {sup 33}P. The study of the {sup 203}Hg {beta} spectrum followed by the 279 keV gamma spectrum is designed to determine the conversion coefficients. The interior spectrum of gold 198 is not of statistical shape either. The form coefficient is determined together with the conversion coefficients which are in slight disagreement with those calculated by Rose or Sliv. An interpretation of the spectrum is put forward which proposes an imperfect compensation for the

Beta decay of 31,32Na and 31Mg

International Nuclear Information System (INIS)

Klotz, G.; Baumann, P.; Bounajma, M.; Huck, A.; Knipper, A.; Walter, G.; Poves, A.; Retamosa, J.

1993-01-01

31,32 Na and 31 Mg beta decays were studied at the CERN on-line mass separator ISOLDE by gamma, gamma-gamma and neutron-gamma measurements. In the 31 Na decay, the assignment of previously reported γ transitions and the observation of a new level at 3760 keV lead to a revised decay scheme. In the 31 Mg → 31 Al decay, a new decay scheme involves ten β branches and three states are reported for the first time. New spectroscopic results have been obtained in the 32 Na β - decay. A previously non-interpreted 1436 keV γ ray is now assigned in the 32 Mg scheme. (author) 33 refs., 16 figs., 12 tabs

Transgenic overexpression of active calcineurin in beta-cells results in decreased beta-cell mass and hyperglycemia.

Directory of Open Access Journals (Sweden)

Ernesto Bernal-Mizrachi

2010-08-01

Full Text Available Glucose modulates beta-cell mass and function through an initial depolarization and Ca(2+ influx, which then triggers a number of growth regulating signaling pathways. One of the most important downstream effectors in Ca(2+ signaling is the calcium/Calmodulin activated serine threonine phosphatase, calcineurin. Recent evidence suggests that calcineurin/NFAT is essential for beta-cell proliferation, and that in its absence loss of beta-cells results in diabetes. We hypothesized that in contrast, activation of calcineurin might result in expansion of beta-cell mass and resistance to diabetes.To determine the role of activation of calcineurin signaling in the regulation of pancreatic beta-cell mass and proliferation, we created mice that expressed a constitutively active form of calcineurin under the insulin gene promoter (caCn(RIP. To our surprise, these mice exhibited glucose intolerance. In vitro studies demonstrated that while the second phase of Insulin secretion is enhanced, the overall insulin secretory response was conserved. Islet morphometric studies demonstrated decreased beta-cell mass suggesting that this was a major component responsible for altered Insulin secretion and glucose intolerance in caCn(RIP mice. The reduced beta-cell mass was accompanied by decreased proliferation and enhanced apoptosis.Our studies identify calcineurin as an important factor in controlling glucose homeostasis and indicate that chronic depolarization leading to increased calcineurin activity may contribute, along with other genetic and environmental factors, to beta-cell dysfunction and diabetes.

Pengaruh Downside Beta, Upside Beta, Dan Beta Terhadap Expected Return (Studi Pada Saham Yang Termasuk Dalam 50 Leading Market Capitalization Di Bursa Efek Indonesia Periode 2012-2015)

OpenAIRE

Sinaga, Maria Goretty; Sulasmiyati, Sri

2017-01-01

Return or return on an investment is required by the investor. Most investors currently prefer shares in emerging markets. Return in the emerging market is not always symmetrical, it shows return in the emerging market is not normally distributed. The purposive of this research want to learn, compare, and explain about some model of stock risk. On this research downside risk expressed with beta downside. The models used in this research among others, dowside beta, upside beta, and beta. The k...

Selectivity of beta-adrenergic stimulating and blocking agents.

Science.gov (United States)

Löfdahl, C G; Svedmyr, N

1984-01-01

Studies have been performed to answer two questions: whether there are subgroups of beta 2-receptors separating effects in bronchial and skeletal muscle and whether beta 1-receptors in asthmatic airways mediate bronchoconstriction. Asthmatic patients have been studied in randomised cross-over trials. Effects on FEV1, heart rate and skeletal muscle tremor have been monitored. In some experimental studies, two new compounds, D2343 and QH-25, have shown a selectivity for beta 2-receptors in bronchial muscle compared to skeletal muscle. Studies in asthmatics did not confirm this. Thus, the beta 2-receptors in the two organs appear to be identical. The clinical effect of beta 1-receptors in the the airways was studied by giving selective beta 1-receptor blocking agents. It was shown that pafenolol , a beta-blocker more beta 1-selective than metoprolol, had less effect on FEV1 than metoprolol given in equipotent beta 1-blocking doses. Beta 1-receptor stimulation with a new selective beta 1-stimulating agent, prenalterol, did not give bronchodilation in doses which gave a significant increase of heart rate. Thus, beta 1-receptors do not contribute to bronchodilation in asthmatic patients.

Sorting out Downside Beta

NARCIS (Netherlands)

G.T. Post (Thierry); P. van Vliet (Pim); S.D. Lansdorp (Simon)

2009-01-01

textabstractDownside risk, when properly defined and estimated, helps to explain the cross-section of US stock returns. Sorting stocks by a proper estimate of downside market beta leads to a substantially larger cross-sectional spread in average returns than sorting on regular market beta. This

The best-beta CAPM

NARCIS (Netherlands)

Zou, L.

2006-01-01

The issue of 'best-beta' arises as soon as potential errors in the Sharpe-Lintner-Black capital asset pricing model (CAPM) are acknowledged. By incorporating a target variable into the investor preferences, this study derives a best-beta CAPM (BCAPM) that maintains the CAPM's theoretical appeal and

Effect of in vitro degradation of poly(D,L-lactide)/beta-tricalcium composite on its shape-memory properties.

Science.gov (United States)

Zheng, Xiaotong; Zhou, Shaobing; Yu, Xiongjun; Li, Xiaohong; Feng, Bo; Qu, Shuxin; Weng, Jie

2008-07-01

The in vitro degradation characteristic and shape-memory properties of poly(D,L-lactide) (PDLLA)/beta-tricalcium phosphate (beta-TCP) composites were investigated because of their wide application in biomedical fields. In this article, PDLLA and crystalline beta-TCP were compounded and interesting shape-memory behaviors of the composite were first investigated. Then, in vitro degradation of the PDLLA/beta-TCP composites with weight ratios of 1:1, 2:1, and 3:1 was performed in phosphate buffer saline solution (PBS) (154 mM, pH 7.4) at 37 degrees C. The effect of in vitro degradation time for PDLLA/beta-TCP composites on shape-memory properties was studied by scanning electron microscopy, differential scanning calorimetry, gel permeation chromatography, X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR). The changes of structural morphology, glass transition temperature (T(g)), molecular weight, and weight loss of composites matrix and pH change of degradation medium indicated that shape-memory effects at different degradation time were nonlinearly influenced because of the breaking down of polymer chain and the formation of degradation products. Furthermore, the results from XRD and FTIR implied that the degradation products, for example, hydroxyapatite (HA), calcium hydrogen phosphate (CaHPO(4)), and calcium pyrophosphate (Ca(2)P(2)O(7)) phases also had some effects on shape-memory properties during the degradation. 2007 Wiley Periodicals, Inc.

Beta genus papillomaviruses and skin cancer.

Science.gov (United States)

Howley, Peter M; Pfister, Herbert J

2015-05-01

A role for the beta genus HPVs in keratinocyte carcinoma (KC) remains to be established. In this article we examine the potential role of the beta HPVs in cancer revealed by the epidemiology associating these viruses with KC and supported by oncogenic properties of the beta HPV proteins. Unlike the cancer associated alpha genus HPVs, in which transcriptionally active viral genomes are invariably found associated with the cancers, that is not the case for the beta genus HPVs and keratinocyte carcinomas. Thus a role for the beta HPVs in KC would necessarily be in the carcinogenesis initiation and not in the maintenance of the tumor. Copyright © 2015 Elsevier Inc. All rights reserved.

Beta thalassemia - a review

Directory of Open Access Journals (Sweden)

R Jha

2014-09-01

Full Text Available Thalassemia is a globin gene disorder that results in a diminished rate of synthesis of one or more of the globin chains. About 1.5% of the global population (80 to 90 million people are carriers of beta Thalassemia. More than 200 mutations are described in beta thalassemia. However not all mutations are common in different ethnic groups. The only effective way to reduce burden of thalassemia is to prevent birth of homozygotes. Diagnosis of beta thalassemia can be done by fetal DNA analysis for molecular defects of beta thalassemia or by fetal blood analysis. Hematopoietic stem cell transplantation is the only available curative approach for Thalassemia. Many patients with thalassemia in underdeveloped nations die in childhood or adolescence. Programs that provide acceptable care, including transfusion of safe blood and supportive therapy including chelation must be established.DOI: http://dx.doi.org/10.3126/jpn.v4i8.11609 Journal of Pathology of Nepal; Vol.4,No. 8 (2014 663-671

The changes in beta-adrenoceptor-mediated cardiac function in experimental hypothyroidism: the possible contribution of cardiac beta3-adrenoceptors.

Science.gov (United States)

Arioglu, E; Guner, S; Ozakca, I; Altan, V M; Ozcelikay, A T

2010-02-01

Thyroid hormone deficiency has been reported to decrease expression and function of both beta(1)- and beta(2)-adrenoceptor in different tissues including heart. The purpose of this study was to examine the possible contribution of beta(3)-adrenoceptors to cardiac dysfunction in hypothyroidism. In addition, effect of this pathology on beta(1)- and beta(2)-adrenoceptor was investigated. Hypothyroidism was induced by adding methimazole (300 mg/l) to drinking water of rats for 8 weeks. Cardiac hemodynamic parameters were measured in anesthetised rats in vivo. Responses to beta-adrenoceptor agonists were examined in rat papillary muscle in vitro. We also studied the effect of hypotyroidism on mRNA expression of beta-adrenoceptors, Gialpha, GRK, and eNOS in rat heart. All of the hemodynamic parameters (systolic, diastolic and mean arterial pressure, left ventricular pressure, heart rate, +dp/dt, and -dp/dt) were significantly reduced by the methimazole treatment. The negative inotropic effect elicited by BRL 37344 (a beta(3)-adrenoceptor preferential agonist) and positive inotropic effects produced by isoprenaline and noradrenaline, respectively, were significantly decreased in papillary muscle of hypothyroid rats as compared to those of controls. On the other hand, hypothyroidism resulted in increased cardiac beta(2)- and beta(3)-adrenoceptor, Gialpha(2), Gialpha(3), GRK3, and eNOS mRNA expressions. However, beta(1)-adrenoceptor and GRK2 mRNA expressions were not changed significantly in this pathology. These results show that mRNA expression of beta(3)-adrenoceptors as well as the signalling pathway components mediated through beta(3)-adrenoceptors are significantly increased in hypothyroid rat heart. Since we could not correlate these alternates with the decreased negative inotropic response mediated by this receptor subtype, it is not clear whether these changes are important for hypothyroid induced reduction in cardiac function.

Standardization of low energy beta and beta-gamma complex emitters by the tracer and the efficiency extrapolation methods

International Nuclear Information System (INIS)

Sahagia, M.

1978-01-01

The absolute standardization of radioactive solutions of low energy beta emitters and beta-gamma emitters with a high probability of disintegration to the ground state is described; the tracer and the efficiency extrapolation methods were used. Both types of radionuclides were mathematically and physically treated in an unified manner. The theoretical relations between different beta spectra were calculated according to Williams' model and experimentally verified for: 35 S + 60 Co, 35 S + 95 Nb, 147 Pm + 60 Co, 14 C + 95 Nb and two beta branches of 99 Mo. The optimum range of beta efficiency variation was indicated. The basic supposition that all beta efficieny tend to unity in the same time was experimentally verified, using two 192 Ir beta branches. Four computer programs, written in the FORTRAN IV language, were elaborated, for the adequate processing of the experimental data. Good precision coefficients according to international standards were obtained in the absolute standardization of 35 S, 147 Pm, 99 Mo solutions. (author)

Beta-lactamases in Enterobacteriaceae in broilers

NARCIS (Netherlands)

Dierikx, C.M.

2013-01-01

Resistance to cephalosprins due to the production of extended spectrum beta-lactamases (ESBLs) or plasmid mediated AmpC beta-lactamases is increasingly found in infections in humans outside the hospital. The genes encoding for these beta-lactamases are located on mobile DNA (plasmids), which can be

Simultaneous determination of F-beta-alanine and beta-alanine in plasma and urine with dual-column reversed-phase high-performance liquid chromatography

NARCIS (Netherlands)

van Kuilenburg, A. B.; Stroomer, A. E.; Peters, G. J.; van Gennip, A. H.

2001-01-01

F-beta-Alanine and beta-alanine were detected in plasma and urine samples with fluorescence detection of orthophthaldialdehyde derivatives of F-beta-alanine and beta-alanine after separation with dual-column reversed-phase HPLC. The detection limits of F-beta-alanine and beta-alanine in the HPLC

Rat beta-LPH, gamma-LPH and beta-endorphin biosynthesized by isolated cells of pars intermedia and pars distalis

International Nuclear Information System (INIS)

Gianoulakis, C.; Seidah, N.G.; Routhier, R.; Chretien, M.

1980-01-01

Rats pars intermedia cells were incubated for 3 h with the following amino-acids: a) 35 S-methionine and 3 H-phenylalamine; b) 3 H-valine; and c) 3 H-valine and 3 H-lysine. Radioactive gamma-lipotropin, beta-lipotropin and beta-endorphin were purified on carboxy- methyl-cellulose and characterized by polyacrylamide disc gel electrophoresis af pH 4.5, molecular weight estimation and microsequencing. Rat gamma-lipotropin was shown to differ slightly from ovine gamma-lipotropin in its NH 2 -terminal amino acid sequence, in containing no methionine and having phenylalanine at position 6, valine at positions 13 and 27, and lysine at position 20. The same variations were observed in the sequence of rat beta-lipotropin, while rat beta-endorphin was shown to be identical to the ovine beta-endorphin. Following a 3-h pulse of rat pars distalis, the cells were extracted with care to avoid beta-lipotropin degradation by proteolytic enzymes. A peptide was purified and identified to be rat beta-endorphin, thus demonstrating that beta-endorphin is biosynthesized in pars distalis and is not an extraction artifact. (author)

El factor de crecimiento transformante beta como blanco terapéutico Transforming growth factor-beta as a therapeutic target

Directory of Open Access Journals (Sweden)

Francisco Javier Gálvez-Gastélum

2004-08-01

Full Text Available El factor de crecimiento transformante beta (TGF-beta es una familia de proteínas que incluye al TGF-beta, activinas y a la proteína morfogénica de hueso (BMP, por sus siglas en inglés, citocinas que son secretadas y se relacionan estructuralmente en diferentes especies de metazoarios. Los miembros de la familia del TGF-beta regulan diferentes funciones celulares como proliferación, apoptosis, diferenciación, migración, y tienen un papel clave en el desarrollo del organismo. El TGF-beta está implicado en varias patologías humanas, incluyendo desórdenes autoinmunes y vasculares, así como enfermedades fibróticas y cáncer. La activación del receptor del TGF-beta propicia su fosforilación en residuos de serina/treonina y dispara la fosforilación de proteínas efectoras intracelulares (smad, que una vez activas se translocan al núcleo para inducir la transcripción de genes blanco, y así regular procesos y funciones celulares. Se están desarrollando novedosas estrategias terapéuticas encaminadas a corregir las alteraciones presentes en patologías que involucran al TGF-beta como actor principal.Transforming growth factor-beta (TGF-beta family members include TGF-beta, activins, and bone morphogenetic proteins (BMP. These proteins are structurally related cytokines secreted in diverse Metazoans. TGF-beta family members regulate cellular functions such as proliferation, apoptosis, differentiation, and migration, and play an important role in organism development. Deregulated TGF-beta family signaling participates in various human pathologies including auto-immune diseases, vascular disorders, fibrotic disease, and cancer. Ligand-induced activation of TGF-beta family receptors with intrinsic serine/threonine kinase activity, triggers phosphorylation of the intracellular effectors of TGF-beta signaling, the Smads proteins. Once these proteins are activated they translocate into the nucleus, where they induce transcription of target

Beta-decay half-lives and level ordering of sup 1 sup 0 sup 2 sup m sup , sup g Rh

CERN Document Server

Shibata, M; Itoh, S; Itoh, S; Yamamoto, H; Kawade, K; Kasugai, Y; Ikeda, Y

1998-01-01

Beta-decay half-lives of the ground state and an isomer of sup 1 sup 0 sup 2 Rh have been determined 207.3(17) d and 3.742(10) y, respectively, by gamma-ray decay curves following each beta-decay. It has been found that a state (2 sup -) which has a shorter half-life (207.3 d) is the ground state from the result that the half-life of the 41.9 keV isomeric gamma-transition was equal to 3.742 y. It has also been confirmed that the 41.9 keV transition is certainly an isomeric transition with X-gamma coincidence measurement.

Standardization of 56Co had been carried out using 4 pi beta-gamma coincidence methods

International Nuclear Information System (INIS)

Wardiyanto, Gatot; Pujadi

2000-01-01

Standardization of exp.56 Co had been carried out using 4 pi beta-gamma coincidence methods. The radionuclide use for calibration of nuclear instruments on range of energy over 1500 keV. The exp.56 Co had been produced by irradiation of proton by using a cyclotron with 15 MeV of energy and 300 mb of cross-section to natural iron target (99,5% of purity) at the Institute for Nuclear Study, University of Tokyo. Source preparation had been done by gravimetry method after the irradiated source was dissolved in 8N HCI solution. The disintegration rate had been measured using 4 pi beta-gamma coincidence apparatus, where the gamm gets sets on 511 and 847 keV gamma-rays. The result measurement is fairly good with the specific activity is 3078 n 15 Bq/mg

Beta particle measurement fundamentals

International Nuclear Information System (INIS)

Alvarez, J.L.

1986-01-01

The necessary concepts for understanding beta particle behavior are stopping power, range, and scattering. Dose as a consequence of beta particle interaction with tissue can be derived and explained by these concepts. Any calculations of dose, however, assume or require detailed knowledge of the beta spectrum at the tissue depth of calculation. A rudimentary knowledge of the incident spectrum can be of use in estimating dose, interpretating dose measuring devices and designing protection. The stopping power and range based on the csda will give a conservative estimate in cases of protection design, as scattering will reduce the range. Estimates of dose may be low because scattering effects were neglected

Energy dispersive X-ray microanalysis of zinc and calcium in organelles of insulin-producing cells of the mouse, rat, and a fish

Energy Technology Data Exchange (ETDEWEB)

Falkmer, S; Odselius, R [Lund Univ. (Sweden); Blondel, B; Prentki, M; Wollheim, C B [Geneva Univ. (Switzerland)

1985-01-01

By means of energy dispersive X-ray microanalysis in the scanning-transmission electron microscope, spectra were obtained from quick-frozen, cryo-ultramicrotome-cut, freeze-dried sections of insulin cells from a fish and a mouse. It was shown that both zinc and calcium are present in significant quantities in native islet cell ..beta.. granules. In the ..beta.. granules of the rat RINm5F insuloma cells calcium, but not zinc, seemed to accumulate; the zinc contents in the secretion granules of these neoplastic ..beta.. cells were probably below the detection limit.

Thermoluminescent dosimetry of beta radiations of {sup 90} Sr/ {sup 90} Y using ZrO{sub 2}: Eu; Dosimetria termoluminiscente de radiaciones beta de {sup 90} Sr/ {sup 90} Y usando ZrO{sub 2}: Eu

Energy Technology Data Exchange (ETDEWEB)

Olvera T, L.; Azorin N, J.; Barrera S, M.; Soto E, A.M. [UAM-I, 09340 Mexico D.F. (Mexico); Rivera M, T. [CICATA-IPN, Legaria 694, 11500 Mexico D.F. (Mexico)

2005-07-01

In this work the results of studying the thermoluminescent properties (TL) of the doped zirconium oxide with europium (ZrO{sub 2}: Eu{sup 3+}) before beta radiations of {sup 90}Sr/ {sup 90}Y are presented. The powders of ZrO{sub 2}: Eu{sup 3+} were obtained by means of the sol-gel technique and they were characterized by means of thermal analysis and by X-ray diffraction. The powders of ZrO{sub 2}: Eu{sup 3+}, previously irradiated with beta particles of {sup 90}Sr/ {sup 90}Y, presented a thermoluminescent curve with two peaks at 204 and 292 C respectively. The TL response of the ZrO{sub 2}: Eu{sup 3+} as function of the absorbed dose was lineal from 2 Gy up to 90 Gy. The fading of the information of the ZrO{sub 2}: Eu{sup 3+} was of 10% the first 2 hours remaining almost constant the information by the following 30 days. The ZrO{sub 2} doped with the (Eu{sup 3+}) ion it was found more sensitive to the beta radiation that the one of zirconium oxide without doping (ZrO{sub 2}) obtained by the same method. Those studied characteristics allow to propose to the doped zirconium oxide with europium like thermoluminescent dosemeter for the detection of the beta radiation. (Author)

Status of evidence for neutrinoless double beta decay, and the future. Genius and genius-TF

International Nuclear Information System (INIS)

Klapdor-Kleingrothaus, H.V.

2004-01-01

The first evidence for neutrinoless double beta decay has been observed in the HEIDELBERG-MOSCOW experiment, which is the most sensitive double beta decay experiment since ten years. This is the first evidence for lepton number violation and proves that the neutrino is a Majorana particle. It further shows that neutrino masses are degenerate. In addition it puts several stringent constraints on other physics beyond the Standard Model. The result from the HEIDEL-BERG-MOSCOW experiment is consistent with recent results from CMB investigations, with high energy cosmic rays, with the result from the g-2 experiment and with recent theoretical work. It is indirectly supported by the analysis of other Ge double beta experiments. The new project GENIUS will cover a wide range of the parameter space of predictions of SUSY for neutralinos as cold dark matter. Further it has the potential to be a real-time detector for low-energy (pp and 7 Be) solar neutrinos. A GENIUS Test Facility has come into operation on May 5, 2003. This is the first time that this novel technique for extreme background reduction in search for rare decays is applied under the background conditions of an underground laboratory. (author)

Monte Carlo simulation of {beta}-{gamma} coincidence system using plastic scintillators in 4{pi} geometry

Energy Technology Data Exchange (ETDEWEB)

Dias, M.S. [Instituto de Pesquisas Energeticas e Nucleares: IPEN-CNEN/SP, Av. Prof. Lineu Prestes 2242, 05508-000 Sao Paulo, SP (Brazil)], E-mail: msdias@ipen.br; Piuvezam-Filho, H. [Instituto de Pesquisas Energeticas e Nucleares: IPEN-CNEN/SP, Av. Prof. Lineu Prestes 2242, 05508-000 Sao Paulo, SP (Brazil); Baccarelli, A.M. [Departamento de Fisica-PUC/SP-Rua Marques de Paranagua 111, 01303-050 Sao Paulo, SP (Brazil); Takeda, M.N. [Universidade Santo Amaro, UNISA-Rua Prof. Eneas da Siqueira Neto 340, 04829-300 Sao Paulo, SP (Brazil); Koskinas, M.F. [Instituto de Pesquisas Energeticas e Nucleares: IPEN-CNEN/SP, Av. Prof. Lineu Prestes 2242, 05508-000 Sao Paulo, SP (Brazil)

2007-09-21

A modified version of a Monte Carlo code called Esquema, developed at the Nuclear Metrology Laboratory in IPEN, Sao Paulo, Brazil, has been applied for simulating a 4{pi}{beta}(PS)-{gamma} coincidence system designed for primary radionuclide standardisation. This system consists of a plastic scintillator in 4{pi} geometry, for alpha or electron detection, coupled to a NaI(Tl) counter for gamma-ray detection. The response curves for monoenergetic electrons and photons have been calculated previously by Penelope code and applied as input data to code Esquema. The latter code simulates all the disintegration processes, from the precursor nucleus to the ground state of the daughter radionuclide. As a result, the curve between the observed disintegration rate as a function of the beta efficiency parameter can be simulated. A least-squares fit between the experimental activity values and the Monte Carlo calculation provided the actual radioactive source activity, without need of conventional extrapolation procedures. Application of this methodology to {sup 60}Co and {sup 133}Ba radioactive sources is presented and showed results in good agreement with a conventional proportional counter 4{pi}{beta}(PC)-{gamma} coincidence system.

Symbiotic Stars in X-rays

Science.gov (United States)

Luna, G. J. M.; Sokoloski, J. L.; Mukai, K.; Nelson, T.

2014-01-01

Until recently, symbiotic binary systems in which a white dwarf accretes from a red giant were thought to be mainly a soft X-ray population. Here we describe the detection with the X-ray Telescope (XRT) on the Swift satellite of 9 white dwarf symbiotics that were not previously known to be X-ray sources and one that was previously detected as a supersoft X-ray source. The 9 new X-ray detections were the result of a survey of 41 symbiotic stars, and they increase the number of symbiotic stars known to be X-ray sources by approximately 30%. Swift/XRT detected all of the new X-ray sources at energies greater than 2 keV. Their X-ray spectra are consistent with thermal emission and fall naturally into three distinct groups. The first group contains those sources with a single, highly absorbed hard component, which we identify as probably coming from an accretion-disk boundary layer. The second group is composed of those sources with a single, soft X-ray spectral component, which likely arises in a region where low-velocity shocks produce X-ray emission, i.e. a colliding-wind region. The third group consists of those sources with both hard and soft X-ray spectral components. We also find that unlike in the optical, where rapid, stochastic brightness variations from the accretion disk typically are not seen, detectable UV flickering is a common property of symbiotic stars. Supporting our physical interpretation of the two X-ray spectral components, simultaneous Swift UV photometry shows that symbiotic stars with harder X-ray emission tend to have stronger UV flickering, which is usually associated with accretion through a disk. To place these new observations in the context of previous work on X-ray emission from symbiotic stars, we modified and extended the alpha/beta/gamma classification scheme for symbiotic-star X-ray spectra that was introduced by Muerset et al. based upon observations with the ROSAT satellite, to include a new sigma classification for sources with

Direct ethanol production from barley beta-glucan by sake yeast displaying Aspergillus oryzae beta-glucosidase and endoglucanase.

Science.gov (United States)

Kotaka, Atsushi; Bando, Hiroki; Kaya, Masahiko; Kato-Murai, Michiko; Kuroda, Kouichi; Sahara, Hiroshi; Hata, Yoji; Kondo, Akihiko; Ueda, Mitsuyoshi

2008-06-01

Three beta-glucosidase- and two endoglucanase-encoding genes were cloned from Aspergillus oryzae, and their gene products were displayed on the cell surface of the sake yeast, Saccharomyces cerevisiae GRI-117-UK. GRI-117-UK/pUDB7 displaying beta-glucosidase AO090009000356 showed the highest activity against various substrates and efficiently produced ethanol from cellobiose. On the other hand, GRI-117-UK/pUDCB displaying endoglucanase AO090010000314 efficiently degraded barley beta-glucan to glucose and smaller cellooligosaccharides. GRI-117-UK/pUDB7CB codisplaying both beta-glucosidase AO090009000356 and endoglucanase AO090010000314 was constructed. When direct ethanol fermentation from 20 g/l barley beta-glucan as a model substrate was performed with the codisplaying strain, the ethanol concentration reached 7.94 g/l after 24 h of fermentation. The conversion ratio of ethanol from beta-glucan was 69.6% of the theoretical ethanol concentration produced from 20 g/l barley beta-glucan. These results showed that sake yeast displaying A. oryzae cellulolytic enzymes can be used to produce ethanol from cellulosic materials. Our constructs have higher ethanol production potential than the laboratory constructs previously reported.

The performance of a hybrid spark chamber beta-ray camera

International Nuclear Information System (INIS)

Aoyama, Takahiko; Watanabe, Tamaki

1978-01-01

This paper describes the performance of a hybrid spark chamber for measuring β-ray emitting radionuclide distribution on a plane source, which was developed to improve the instability of usual self-triggering spark chambers. The chamber consists of a parallel plate spark chamber gap and a parallel plate proportional chamber gap composed of mesh electrodes in the same gas space, and is operated by flowing gas, a mixture of argon and ethanol saturated vapor at 0 0 C, continuously through it. Instability is due to the occurrence of spurious sparks not caused by incident particles and it became conspicuous in the small intensity of incident particles. The hybrid spark chamber enabled us to obtain good counting plateau, that is, good stability for especially small intensity of β-rays and even for the background by setting up gas multiplication in the proportional chamber gap moderately high. Good spatial resolution less than 1 mm was obtained for 3 H and 14 C by keeping the distance between the chamber cathode and the source less than 1 mm. In order to obtain good spatial resolution, it is desirable to keep the overvoltage as small as possible while small overvoltage results in the deterioration of the uniformity of sensitivity. It was found by theoretical estimation and experiment that for a given large overvoltage the spatial resolution was improved by increasing the gas multiplication in the proportional chamber gap. The hybrid spark chamber has a relatively long dead time. When there being a number of active spots having different activities in a detection area, the sparking efficiency of a weak active spot also decreases by large counting loss due to the total strong activity. (auth.)

MetroBeta: Beta Spectrometry with Metallic Magnetic Calorimeters in the Framework of the European Program of Ionizing Radiation Metrology

Science.gov (United States)

Loidl, M.; Beyer, J.; Bockhorn, L.; Enss, C.; Györi, D.; Kempf, S.; Kossert, K.; Mariam, R.; Nähle, O.; Paulsen, M.; Rodrigues, M.; Schmidt, M.

2018-05-01

MetroBeta is a European project aiming at the improvement of the knowledge of the shapes of beta spectra, both in terms of theoretical calculations and measurements. It is part of a common European program of ionizing radiation metrology. Metallic magnetic calorimeters (MMCs) with the beta emitter embedded in the absorber have in the past proven to be among the best beta spectrometers, in particular for low-energy beta transitions. Within this project, new designs of MMCs optimized for five different beta energy ranges were developed. A new detector module with thermal decoupling of MMC and SQUID chips was designed. An important aspect of the research and development concerns the source/absorber preparation techniques. Four beta spectra with maximum energies ranging from 76 to 709 keV will be measured. Improved theoretical calculation methods and complementary measurement techniques complete the project.

Analysis of interleukin (IL)-1 beta and transforming growth factor (TGF)-beta-induced signal transduction pathways in IL-2 and TGF-beta secretion and proliferation in the thymoma cell line EL4.NOB-1.

Science.gov (United States)

Siese, A; Jaros, P P; Willig, A

1999-02-01

In the present study we investigated the interleukin (IL)-1beta and transforming growth factor-beta1 (TGF-beta1)-mediated proliferation, and production of IL-2 and TGF-beta, in the murine T-cell line, EL4.NOB-1. This cell line is resistant to TGF-beta concerning growth arrest but not autoinduction or suppression of IL-1-induced IL-2 production. When cocultured with IL-1beta, TGF-beta showed growth-promoting activity that could be antagonized by adding the phosphatidyl choline-dependent phospholipase C (PC-PLC) inhibitor, D609. Using specific enzyme inhibitors of protein kinases (PK) C and A, mitogen-activated protein kinase (MAPK), phospholipase A2 (PLA2), phosphatidylinositol-dependent (PI)-PLC and PC-PLC, we showed that IL-1beta-induced IL-2 synthesis was dependent on all investigated kinases and phospholipases, except PC-PLC. TGF-beta1 was able to inhibit IL-2 synthesis by the activation of PKA and MAPK. The same kinases are involved in TGF-beta autoinduction that is accompanied by a secretion of the active but not the latent growth factor and is antagonized by IL-1beta. Addition of the PI-PLC inhibitor, ET 18OCH3, or the PLA2 inhibitor (quinacrine) alone, resulted in secretion of latent TGF-beta and, in the case of ET 18OCH3, active TGF-beta. These data implicate a role for PI-PLC and PLA2 in the control of latency and secretion. Analysis of specific tyrosine activity and c-Fos expression showed synergistic but no antagonistic effects. These events are therefore not involved in IL- and TGF-beta-regulated IL-2 and TGF-beta production, but might participate in IL-1/TGF-beta-induced growth promotion.

Monitor for alpha beta contamination of hands; Moniteur de contamination alpha beta des mains

Energy Technology Data Exchange (ETDEWEB)

Guitton, J

1958-07-01

The following specifications of hands alpha beta contamination monitor are presented: the position of the hands, the detection and separation of alpha and beta, the information processing, the programming, the results presentation and general characteristics. (A.L.B.)

Study on mineral components of rat calvaria by means of X-ray powder diffraction analysis and Raman microprobe spectroscopy

Energy Technology Data Exchange (ETDEWEB)

Tamura, Norihiro [Meikai Univ., Sakado, Saitama (Japan). School of Dentistry

2000-07-01

The present study was designed to examine the occurrence of the precursor minerals of hydroxyapatite (HA) during the process of HA formation in the rat calvaria. Dried and powdered rat calvaria and synthetic samples, such as HA, dicalcium phosphate dihydrate (DCPD), octacalcium phosphate (OCP), ({beta}-calcium pyrophosphate) and ({beta}-tricalcium phosphate), were used. Determinations were carried out by X-ray powder diffraction and Raman microprobe spectrometry. In general, significant widening of the diffraction peaks was shown to occur after the plasma ashing was performed for the X-ray diffraction. As a result, two adjacent peaks seen normally in the diffraction angles (2 {theta}) 30-35 deg, which is a characteristic feature of HA, were found to fuse with each other, forming a widened single peak. Also, there was a tendency for the intensity of the diffraction peaks to increase with age. With regard to the effect of plasma ashing on the crystallograms of synthetic specimens, all specimens manifested sharp peak patterns except DCPD and OCP. In contrast, a widening of diffraction peaks was observed in the DCPD and OCP samples, indicating that crystallinity had changed during the pretreatment. Results obtained from both vital and synthetic samples after heat treatment at 1000 deg C were as follow: Clearcut diffraction patterns, characteristics of HA, were obtained in all of the calvaria samples. Further, {beta}-TCP was produced by heat treatment of OCP, and its pattern was detected in the samples from rats younger than 6 days of age. Amounts of {beta}-TCP in percentage were disclosed to be 40.2% in embryonal samples, 28.4% in newborn samples, and 18.6% in 6-day-old samples. But no {beta}-TCP could be detected in the 12-week-old samples, indicating that the amount of {beta}-TCP in calvaria decreased with age. We also found that ashing pretreatment did not cause any changes in the samples of HA, {beta}-CPP, and {beta}-TCP. Further, DCPD and {beta}-CPP samples shared

Partitioning diversity into independent alpha and beta components.

Science.gov (United States)

Jost, Lou

2007-10-01

Existing general definitions of beta diversity often produce a beta with a hidden dependence on alpha. Such a beta cannot be used to compare regions that differ in alpha diversity. To avoid misinterpretation, existing definitions of alpha and beta must be replaced by a definition that partitions diversity into independent alpha and beta components. Such a unique definition is derived here. When these new alpha and beta components are transformed into their numbers equivalents (effective numbers of elements), Whittaker's multiplicative law (alpha x beta = gamma) is necessarily true for all indices. The new beta gives the effective number of distinct communities. The most popular similarity and overlap measures of ecology (Jaccard, Sorensen, Horn, and Morisita-Horn indices) are monotonic transformations of the new beta diversity. Shannon measures follow deductively from this formalism and do not need to be borrowed from information theory; they are shown to be the only standard diversity measures which can be decomposed into meaningful independent alpha and beta components when community weights are unequal.

Optical characterization of {beta}-FeSi{sub 2} thin films prepared on fused quartz by femtosecond laser

Energy Technology Data Exchange (ETDEWEB)

Zhou Youhua [Wuhan National Laboratory for Optoelectronics and School of Optoelectronics Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074 (China); School of Physics and Information Engineering, Jianghan University, Wuhan 430056 (China); Lu Peixiang [Wuhan National Laboratory for Optoelectronics and School of Optoelectronics Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074 (China)]. E-mail: lupeixiang@mail.hust.edu.cn; Yang Guang [Wuhan National Laboratory for Optoelectronics and School of Optoelectronics Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074 (China); Long Hua [Wuhan National Laboratory for Optoelectronics and School of Optoelectronics Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074 (China); Zheng Qiguang [Wuhan National Laboratory for Optoelectronics and School of Optoelectronics Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074 (China)

2007-10-01

Single-phase {beta}-FeSi{sub 2} thin films have been grown on quartz substrates using femtosecond laser deposition (800 nm, 50 fs, 1 kHz) under gas pressure of 3.0x10{sup -4} Pa. X-ray diffraction (XRD) and field-emission scanning electron microscopy (SEM) were used to determine the structural properties and surface images of the films. Typical XRD patterns of the film showed that no other diffraction peak except {beta}-FeSi{sub 2} was found. The SEM results indicated that the films were composed of well-distributed grains, in the range 50-150 nm in diameter. In addition, normal incidence spectral transmittance and reflectance data suggested that the {beta}-FeSi{sub 2} film has a direct energy gap of about 0.85 eV. The thickness of the layer and the refractive index of the film were determined by performed calculation in the wavelength range 1.9-2.7 {mu}m. Furthermore, the Raman spectra of the films were also discussed.

Magnetic moment and beta decay of RaE

International Nuclear Information System (INIS)

Morita, Masato; Ohtsubo, Hisao; Arita, Kozo.

1976-01-01

Asymmetry of the beta-ray angular distribution in polarized RaE is evaluated with the numerical values of nuclear matrix elements, i∫r, ∫α and ∫sigma x r, which are derived by the method of the least chi-square fit to the experimental data on the spectral shape, longitudinal polarization and ft value. The magnetic moment of RaE is known to have a negative sign from this calculation, the measured asymmetry in Tokyo and the knowledge about the internal magnetic field at decaying nucleus. A consistent explanation of i∫r, ∫sigma x r and the magnetic moment of RaE is obtained in a shell model, where the tensor forces in the residual interaction and the core polarization are properly taken into account. (auth.)

Conditional Betas and Investor Uncertainty

OpenAIRE

Fernando D. Chague

2013-01-01

We derive theoretical expressions for market betas from a rational expectation equilibrium model where the representative investor does not observe if the economy is in a recession or an expansion. Market betas in this economy are time-varying and related to investor uncertainty about the state of the economy. The dynamics of betas will also vary across assets according to the assets' cash-flow structure. In a calibration exercise, we show that value and growth firms have cash-flow structures...

[{sup 18}F]{beta}-CIT-FP is superior to [{sup 11}C]{beta}-CIT-FP for quantitation of the dopamine transporter

Energy Technology Data Exchange (ETDEWEB)

Lundkvist, Camilla; Halldin, Christer; Ginovart, Nathalie; Swahn, Carl-Gunnar; Farde, Lars

1997-10-01

{beta}-CIT-FP [N-(3-fluoropropyl)-2{beta}-carbomethoxy-3{beta}-(4-iodophenyl)nortropane] is a cocaine analogue with high affinity for the dopamine transporter. Positron emission tomography (PET) studies with [O-methyl-{sup 11}C]{beta}-CIT-FP ([{sup 11}C]{beta}-CIT-FP) has shown that equilibrium conditions were approached but, however, not reached at the end of measurement. Moreover, metabolite studies of [{sup 11}C]{beta}-CIT-FP in monkey plasma demonstrated a lipophilic-labelled metabolite that may enter the brain. We therefore labelled {beta}-CIT-FP with fluorine-18 in a position that may avoid the formation of labelled lipophilic metabolites. The more long-lived radionuclide ({sup 18}F) was used to allow for measurements over longer time. [N-fluoropropyl-{sup 18}F]{beta}-CIT-FP ([{sup 18}F]{beta}-CIT-FP) was prepared by N-alkylation of nor-{beta}-CIT with [{sup 18}F]fluoropropyl bromide. PET studies were performed in cynomolgus monkeys. [{sup 18}F]{beta}-CIT-FP entered the brain rapidly. There was a high concentration of radioactivity in the striatum and much lower in the thalamus, neocortex, and cerebellum. The striatum-to-cerebellum ratio was about 5 at time of transient equilibrium, which occurred after 60 to 100 min. After pretreatment with GBR 12909, radioactivity in the striatum was markedly reduced, thus indicating specific [{sup 18}F]{beta}-CIT-FP binding to the dopamine transporter. The fraction of unchanged [{sup 18}F]{beta}-CIT-FP determined by HPLC was 10-15% after 140 min. No lipophilic labelled metabolites were detected. The absence of measurable lipophilic labelled metabolites and the occurrence of transient equilibrium within the time of the PET measurement indicate that [{sup 18}F]{beta}-CIT-FP is superior to [{sup 11}C]{beta}-CIT-FP as a PET radioligand for quantification of the dopamine transporter in the human brain.

Monitoring body iron burden using X-ray fluorescence (XRF)

International Nuclear Information System (INIS)

Farquharson, M.J.; Bagshaw, A.P.

2001-01-01

X-ray fluorescence, using Cu K alpha and K beta radiation, has been used to measure the Fe content of skin of two groups of rats, one Fe overloaded and one control group. These skin Fe levels were compared to the liver and heart Fe levels measured using colorimetry. Correlation coefficients of 0.86 and 0.88 respectively were found indicating that skin Fe levels may be a potential marker for body iron burden.

Reduction of beta-interference in gamma-spectrometric measurements of neutron-irradiated geological material

International Nuclear Information System (INIS)

Garmann, L.B.

1986-01-01

The analytical technique for INAA, when applied to geological materials, is improved by introducing an electromagnetic field between sample and detector. This field lowers the bremsstrahlung background intensity in the gamma-spectrum by reducing the number of beta-particles reaching the detector. Thus precision, accuracy and lower detection limit are improved. The technique was used on alkalisyenite and on meteoritic material, rocks containing high quantities of sodium and iron, respectively. After neutron irradiation, the induced nuclides sup(24)Na and sup(59)Fe are responsible for high bremsstrahlung interference, which under normal analyitical conditions would mask any x-ray or gamma-ray peaks of interest. The technique is easily applied to multielement analysis of geological and biological materials. It can be combined with sophisticated spectrum-treating techniques such as spectrum stripping and spectrum smoothing, or coincidence-anticoincidence circuits. (author)

Reduced beta-adrenergic receptor activation decreases G-protein expression and beta-adrenergic receptor kinase activity in porcine heart.

OpenAIRE

Ping, P; Gelzer-Bell, R; Roth, D A; Kiel, D; Insel, P A; Hammond, H K

1995-01-01

To determine whether beta-adrenergic receptor agonist activation influences guanosine 5'-triphosphate-binding protein (G-protein) expression and beta-adrenergic receptor kinase activity in the heart, we examined the effects of chronic beta 1-adrenergic receptor antagonist treatment (bisoprolol, 0.2 mg/kg per d i.v., 35 d) on components of the myocardial beta-adrenergic receptor-G-protein-adenylyl cyclase pathway in porcine myocardium. Three novel alterations in cardiac adrenergic signaling as...

Fundamentals of gamma-ray measurements and radiometric analyses

International Nuclear Information System (INIS)

Hochel, R.C.

1990-01-01

There are four primary modes of radioactive decay. All can be measured using various types of detectors and are the basis of many analytical techniques and much of what we know about the nucleus and its structure. Alpha particle emission occurs mostly in heavy nuclei of atomic number, Z, greater than 82 like Po, Ra, Th, and U, etc. Beta particles are simply electrons. They are emitted from the nucleus with a distribution of energies ranging from 0--3 MeV. Gamma-rays are photons with energies ranging from a few keV to 10 MeV or more. They usually follow alpha or beta decay, and depending on their energy, can have considerable range in matter. Neutrons are emitted in fission processes and also from a few of the highly excited fission product nuclei. Fission neutrons typically have energies of 1--2 MeV. Like gamma-rays, they have long ranges. The energies involved in nuclear decay processes are much higher than anything encountered in, say, chemical reactions. They are at the very top of the electromagnetic spectrum -- about a million times more energetic than visible light. As a result, these particles always produce ionization, either directly or indirectly, as they pass through matter. It is this ionization which is the basis of all radiation detectors

The {beta}-decay Paul trap: A radiofrequency-quadrupole ion trap for precision {beta}-decay studies

Energy Technology Data Exchange (ETDEWEB)

Scielzo, N.D., E-mail: scielzo1@llnl.gov [Physics Division, Argonne National Laboratory, Argonne, Illinois 60439 (United States); Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, California 94550 (United States); Li, G. [Physics Division, Argonne National Laboratory, Argonne, Illinois 60439 (United States); Department of Physics, McGill University, Montreal, Quebec, Canada H3A 2T8 (Canada); Sternberg, M.G.; Savard, G. [Physics Division, Argonne National Laboratory, Argonne, Illinois 60439 (United States); Department of Physics, University of Chicago, Chicago, Illinois 60637 (United States); Bertone, P.F. [Physics Division, Argonne National Laboratory, Argonne, Illinois 60439 (United States); Buchinger, F. [Department of Physics, McGill University, Montreal, Quebec, Canada H3A 2T8 (Canada); Caldwell, S. [Physics Division, Argonne National Laboratory, Argonne, Illinois 60439 (United States); Department of Physics, University of Chicago, Chicago, Illinois 60637 (United States); Clark, J.A. [Physics Division, Argonne National Laboratory, Argonne, Illinois 60439 (United States); Crawford, J. [Department of Physics, McGill University, Montreal, Quebec, Canada H3A 2T8 (Canada); Deibel, C.M. [Physics Division, Argonne National Laboratory, Argonne, Illinois 60439 (United States); Joint Institute for Nuclear Astrophysics, Michigan State University, East Lansing, Michigan 48824 (United States); Fallis, J. [Physics Division, Argonne National Laboratory, Argonne, Illinois 60439 (United States); Department of Physics and Astronomy, University of Manitoba, Winnipeg, Manitoba, Canada R3T 2N2 (Canada); Greene, J.P. [Physics Division, Argonne National Laboratory, Argonne, Illinois 60439 (United States); and others

2012-07-21

The {beta}-decay Paul trap is a linear radiofrequency-quadrupole ion trap that has been developed for precision {beta}-decay studies. The design of the trap electrodes allows a variety of radiation detectors to surround the cloud of trapped ions. The momentum of the low-energy recoiling daughter nuclei following {beta} decay is negligibly perturbed by scattering and is available for study. This advantageous property of traps allows the kinematics of particles that are difficult or even impossible to directly detect to be precisely reconstructed using conservation of energy and momentum. An ion-trap system offers several advantages over atom traps, such as higher trapping efficiencies and element-independent capabilities. The first precision experiment using this system is a measurement of {beta}-decay angular correlations in the decay of {sup 8}Li performed by inferring the momentum of the neutrino from the kinematic shifts imparted to the breakup {alpha} particles. Many other {beta}-decay studies that would benefit from a determination of the nuclear recoil can be performed with this system.

Adverse CNS-effects of beta-adrenoceptor blockers.

Science.gov (United States)

Gleiter, C H; Deckert, J

1996-11-01

In 1962 propranolol, the first beta adrenoceptor antagonist (beta blocker), was brought on to the market. There is now a host of different beta blockers available, and these compounds are among the most commonly prescribed groups of drugs. The efficacy of beta blockers has been proven predominantly for the treatment of cardiovascular diseases. Beta blockers are also used for certain types of CNS disorders, such as anxiety disorders, essential tremor and migraine. While low toxicity means that they have a favorable risk-benefit ratio, given the high intensity of use, it is essential to have a comprehensive knowledge of adverse events. Adverse events of beta blockers that can be related to the CNS are quite often neglected, even in textbooks of clinical pharmacology or review articles, and thus often misdiagnosed. The following article, therefore, after summarizing the use of beta blockers for CNS indications, critically reviews the literature on centrally mediated adverse events. General pharmacological features of beta blockers and their molecular basis of action will briefly be addressed to the extent that they are or may become relevant for central nervous pharmacotherapy and side-effects.

Interactions between beta subunits of the KCNMB family and Slo3: beta4 selectively modulates Slo3 expression and function.

Directory of Open Access Journals (Sweden)

Cheng-Tao Yang

2009-07-01

Full Text Available The pH and voltage-regulated Slo3 K(+ channel, a homologue of the Ca(2+- and voltage-regulated Slo1 K(+ channel, is thought to be primarily expressed in sperm, but the properties of Slo3 studied in heterologous systems differ somewhat from the native sperm KSper pH-regulated current. There is the possibility that critical partners that regulate Slo3 function remain unidentified. The extensive amino acid identity between Slo3 and Slo1 suggests that auxiliary beta subunits regulating Slo1 channels might coassemble with and modulate Slo3 channels. Four distinct beta subunits composing the KCNMB family are known to regulate the function and expression of Slo1 Channels.To examine the ability of the KCNMB family of auxiliary beta subunits to regulate Slo3 function, we co-expressed Slo3 and each beta subunit in heterologous expression systems and investigated the functional consequences by electrophysiological and biochemical analyses. The beta4 subunit produced an 8-10 fold enhancement of Slo3 current expression in Xenopus oocytes and a similar enhancement of Slo3 surface expression as monitored by YFP-tagged Slo3 or biotin labeled Slo3. Neither beta1, beta2, nor beta3 mimicked the ability of beta4 to increase surface expression, although biochemical tests suggested that all four beta subunits are competent to coassemble with Slo3. Fluorescence microscopy from beta4 KO mice, in which an eGFP tag replaced the deleted exon, revealed that beta4 gene promoter is active in spermatocytes. Furthermore, quantitative RT-PCR demonstrated that beta4 and Slo3 exhibit comparable mRNA abundance in both testes and sperm.These results argue that, for native mouse Slo3 channels, the beta4 subunit must be considered as a potential interaction partner and, furthermore, that KCNMB subunits may have functions unrelated to regulation of the Slo1 alpha subunit.

In vitro digestibility of beta-casein and beta-lactoglobulin under simulated human gastric and duodenal conditions: A multi-laboratory evaluation

DEFF Research Database (Denmark)

Mandalari, G.; Adel-Patient, K.; Barkholt, Vibeke

2009-01-01

Initially the resistance to digestion of two cow's milk allergens, beta-casein, and beta-lactoglobulin (beta-Lg), was compared using a "high-protease assay" and a "low-protease assay" in a single laboratory. The low-protease assay represents an alternative standardised protocol mimicking conditions...... found in the gastrointestinal tract. For the high-protease assay, both proteins were incubated with either pepsin or pancreatin and digestion monitored by sodium dodecyl sulphate-polyacrylamide gel electrophoresis and reverse phase-high performance liquid chromatography. The low-protease assay involved...... gastroduodenal digestion in the presence or absence of phosphatidylcholine (PC). Both beta-casein and beta-Lg were susceptible to hydrolysis by pepsin and pancreatin in the high-protease assay. In contrast, the kinetics of beta-casein digestion in the low-protease assay were slower, beta-Lg being pepsin...

Murrayafoline A attenuates the Wnt/{beta}-catenin pathway by promoting the degradation of intracellular {beta}-catenin proteins

Energy Technology Data Exchange (ETDEWEB)

Choi, Hyuk; Gwak, Jungsug; Cho, Munju; Ryu, Min-Jung [PharmacoGenomics Research Center, Inje University, Busan 614-735 (Korea, Republic of); Lee, Jee-Hyun; Kim, Sang Kyum; Kim, Young Ho [College of Pharmacy, Chungnam National University, Daejeon 305-764 (Korea, Republic of); Lee, Gye Won [Department of Pharmaceutical Engineering, Konyang University, Nonsan 320-711 (Korea, Republic of); Yun, Mi-Young [Department of Beauty Health Care, Daejeon University, Daejeon 305-764 (Korea, Republic of); Cuong, Nguyen Manh [Institute of Natural Products Chemistry, Vietnam Academy of Science and Technology, Hanoi (Viet Nam); Shin, Jae-Gook [PharmacoGenomics Research Center, Inje University, Busan 614-735 (Korea, Republic of); Song, Gyu-Yong, E-mail: gysong@cnu.ac.kr [College of Pharmacy, Chungnam National University, Daejeon 305-764 (Korea, Republic of); Oh, Sangtaek, E-mail: ohsa@inje.ac.kr [PharmacoGenomics Research Center, Inje University, Busan 614-735 (Korea, Republic of)

2010-01-01

Molecular lesions in Wnt/{beta}-catenin signaling and subsequent up-regulation of {beta}-catenin response transcription (CRT) occur frequently during the development of colon cancer. To identify small molecules that suppress CRT, we screened natural compounds in a cell-based assay for detection of TOPFalsh reporter activity. Murrayafoline A, a carbazole alkaloid isolated from Glycosmis stenocarpa, antagonized CRT that was stimulated by Wnt3a-conditioned medium (Wnt3a-CM) or LiCl, an inhibitor of glycogen synthase kinase-3{beta} (GSK-3{beta}), and promoted the degradation of intracellular {beta}-catenin without altering its N-terminal phosphorylation at the Ser33/37 residues, marking it for proteasomal degradation, or the expression of Siah-1, an E3 ubiquitin ligase. Murrayafoline A repressed the expression of cyclin D1 and c-myc, which is known {beta}-catenin/T cell factor (TCF)-dependent genes and thus inhibited the proliferation of various colon cancer cells. These findings indicate that murrayafoline A may be a potential chemotherapeutic agent for use in the treatment of colon cancer.

Encapsulation and release of the hypnotic agent zolpidem from biodegradable polymer microparticles containing hydroxypropyl-beta-cyclodextrin.

Science.gov (United States)

Trapani, Giuseppe; Lopedota, Angela; Boghetich, Giancarlo; Latrofa, Andrea; Franco, Massimo; Sanna, Enrico; Liso, Gaetano

2003-12-11

The goal of this study was to design a prolonged release system of the hypnotic agent zolpidem (ZP) useful for the treatment of insomnia. In this work, ZP alone or in the presence of HP-beta-CD was encapsulated in microparticles constituted by poly(DL-lactide) (PDLLA) and poly(DL-lactide-co-glycolide) (PLGA) and the drug release from these systems was evaluated. ZP alone-loaded microparticles were prepared by the classical O/W emulsion-solvent evaporation method. Conversely, ZP/HP-beta-CD containing microparticles were prepared by the W/O/W emulsion-solvent evaporation method following two different procedures (i.e. A and B). Following procedure A, the previously produced ZP/HP-beta-CD solid complex was added to the water phase of primary emulsion. In the procedure B, HP-beta-CD was added to the aqueous phase and ZP to the organic phase. The resulting microparticles were characterized about morphology, size, encapsulation efficiency and release rates. FT-IR, X-ray, and DSC results suggest the drug is in an essentially amorphous state within the microparticles. The release profiles of ZP from microparticles were in general biphasic, being characterized by an initial burst effect and a subsequent slow ZP release. It resulted that co-encapsulating ZP with or without HP-beta-CD in PDLLA and PLGA the drug release from the corresponding microparticles was protracted. Moreover, in a preliminary pharmacological screening, the ataxic activity in rats was investigated and it was found that intragastric administration of the ZP/HP-beta-CD/PLGA microparticles prepared according to procedure B produced the same ataxic induction time as the one induced by the currently used formulation Stilnox. Interestingly moreover, there was a longer ataxic lasting and a lower intensity of ataxia produced by the ZP/HP-beta-CD/PLGA-B-formulation already after 60 min following the administration. However, a need for further pharmacokinetic and pharmacodynamic studies resulted to fully evaluate

Coexistence of beta 1- and beta 2-adrenoceptors in the rabbit heart: quantitative analysis of the regional distribution by (-)-/sup 3/H-dihydroalprenolol binding

Energy Technology Data Exchange (ETDEWEB)

Brodde, O.E.; Leifert, F.J.; Krehl, H.J.

1982-01-01

We determined the amount of beta 1- and beta 2-adrenoceptors in right and left atria and ventricles of rabbits. For this purpose inhibition of specific (-)-/sup 3/H-dihydroalprenolol ((-)-/sup 3/H-DHA) binding (5 nM) by beta 1-selective (practolol, metoprolol) and beta 2-selective (zinterol, IPS 339) adrenergic drugs was determined and analyzed by pseudo-Scatchard (Hofstee) plots. For both atria, inhibition of binding by the four selective beta-adrenergic drugs resulted in non-linear Hofstee plots, suggesting the coexistence of both beta-adrenoceptor subtypes. From these plots we calculated a beta 1:beta 2-adrenoceptor ratio of 72:28 for the right atrium and of 82:18 for the left. In contrast, only a very small amount of beta 2-adrenoceptors (approximately 5-7% of the total beta-adrenoceptor population) could be detected in the ventricles. For comparison we analyzed the inhibition of specific (-)-/sup 3/H-DHA binding in tissues with homogeneous population of beta-adrenoceptors (beta 1:guinea pig left ventricle; beta 2: cerebellum of mature rats). For both tissues the four selective beta-adrenergic drugs showed linear Hofstee plots, demonstrating that in tissues with homogeneous beta-receptor population interaction of each drug with the receptor followed simple mass-action kinetics. We conclude that beta 1- and beta 2-adrenoceptors coexist in rabbit atria while the ventricles are predominantly endowed the beta 1-adrenoceptors.

Development and applications of beta and near beta titanium alloys

International Nuclear Information System (INIS)

Takemura, A.; Ohyama, H.; Nishimura, T.; Abumiya, T.

1993-01-01

In this report the authors introduced application of beta and near beta titanium alloys also development and processing of these alloys at Kobe Steel LTD. Ti-15Mo-5Zr-3Al is an alloy developed by Kobe Steel which has been applied for variety of sporting goods, also used as an erosion shield of steam turbine blades. Ti-15Mo-5Zr-3Al high strength wire for valve springs is under development. New beta alloys(Ti-V-Nb-Sn-Al) are under development which have lower flow stress at room temperature than Ti 15V-3Cr-3Sn-3Al, expected to improve productivity of cold forging. NNS forging and thermo mechanical treatment of Ti-10V-2Fe-3Al were studied. Ti-10V-2Fe3Al steam turbine blades and structural parts for aircraft were developed. Fine grain cold strips of Ti 15V-3Cr-3Sn-3Al are produced by annealing and pickling process. These cold strips are used for parts of a fishing rod

BETASCAN: probable beta-amyloids identified by pairwise probabilistic analysis.

Directory of Open Access Journals (Sweden)

Allen W Bryan

2009-03-01

Full Text Available Amyloids and prion proteins are clinically and biologically important beta-structures, whose supersecondary structures are difficult to determine by standard experimental or computational means. In addition, significant conformational heterogeneity is known or suspected to exist in many amyloid fibrils. Recent work has indicated the utility of pairwise probabilistic statistics in beta-structure prediction. We develop here a new strategy for beta-structure prediction, emphasizing the determination of beta-strands and pairs of beta-strands as fundamental units of beta-structure. Our program, BETASCAN, calculates likelihood scores for potential beta-strands and strand-pairs based on correlations observed in parallel beta-sheets. The program then determines the strands and pairs with the greatest local likelihood for all of the sequence's potential beta-structures. BETASCAN suggests multiple alternate folding patterns and assigns relative a priori probabilities based solely on amino acid sequence, probability tables, and pre-chosen parameters. The algorithm compares favorably with the results of previous algorithms (BETAPRO, PASTA, SALSA, TANGO, and Zyggregator in beta-structure prediction and amyloid propensity prediction. Accurate prediction is demonstrated for experimentally determined amyloid beta-structures, for a set of known beta-aggregates, and for the parallel beta-strands of beta-helices, amyloid-like globular proteins. BETASCAN is able both to detect beta-strands with higher sensitivity and to detect the edges of beta-strands in a richly beta-like sequence. For two proteins (Abeta and Het-s, there exist multiple sets of experimental data implying contradictory structures; BETASCAN is able to detect each competing structure as a potential structure variant. The ability to correlate multiple alternate beta-structures to experiment opens the possibility of computational investigation of prion strains and structural heterogeneity of amyloid

Teratogenic effects of 60Co gamma rays irradiation on rat embryos

International Nuclear Information System (INIS)

Lee, Juing-Yi; Okuda, Hiroe; Tutimoto, Sigeo; Satow, Yukio

1987-01-01

The teratogenicity of 60 Co gamma rays was evaluated in Donryu rats. The results were compared with those of triterated water (HTO) for determining relative biological effectiveness (RBE) for incidence of malformations and LD 50 in rats. Pregnant rats were irradiated with a 60 Co source at a dose-rate of 0.5 Gy/min or 0.01 Gy/min on day 7, 8, 9, 10 or 11 of gestation with 0.8, 1.0, 1.2, 1.5, 2.0, 2.3, 2.5, 2.8 or 3.0 Gy. HTO was administered intraperitoneal injection to pregnant rats at various doses on day 7, 8, 9, 10 and 11 of gestation. The rats were sacrificed on day 18 and the offspring were examined for external and visceral malformations. Mortality, teratogenicity and effects on fetal growth were day-and dosage-dependent in both radiation groups. Congenital malformations were found most frequently in the 9-day irradiated group and followed by the 8, 11, 10 and 7-day irradiated groups. The incidence of cardiovascular anomalies was highest, especially in the day 9 of gestation group, followed by malformations in the central nervous system, craniofacial system, respiratory system, hind limbs and tail. Beta rays from HTO were found to be more effective than γ rays in inducing congenital malformations. The RBE for incidence of malformations and LD 50 was between 1.3 and 1.5. These studies suggest that simulator of tritium irradiation is urgently needed to investigate the biological effects on rats to estimate the human risks, with respect to RBE of tritium beta rays. (author)

Specific radioimmunoassay of human. beta. -endorphin in unextracted plasma

Energy Technology Data Exchange (ETDEWEB)

Wiedemann, E. (Univ. of California, Berkeley); Saito, T.; Linfoot, J.A.; Li, C.H.

1979-09-01

With an antiserum against human ..beta..-endorphin (..beta..-EP) crossreacting <2% with human ..beta..-lipotropin (..beta..-LPH) by weight we have developed a radioimmunoassay that can detect 1 pg ..beta..-EP in diluted raw plasma. In a.m. fasting plasma of 14 normal subjects ..beta..-EP ranged from <5 to 45 pg/ml. ..beta..-EP was elevated in untreated, but normal in successfully treated Cushing's disease; undetectable in a patient with adrenal adenoma; extremely high in Nelson's syndrome; and elevated in a patient with bronchogenic carcinoma before, but undetectable after tumor resection. In subjects with intact hypothalamic-pituitary-adrenal axis, ..beta..-EP was undectectable after dexamethasone and increased after metyrapone administration and insulin-induced hypoglycemia. ..beta..-EP concentration was considerably lower in serum than in simultaneously collected plasma, but increased in serum left unfrozen for several hours after clot removal. Thus, ..beta..-EP behaves like a hormone responding to the same stimuli as ACTH and ..beta..-LPH and blood appears to contain enzymes both generating and destroying immunoreactive ..beta..-EP.

The potential role of SOCS-3 in the interleukin-1beta-induced desensitization of insulin signaling in pancreatic beta-cells

DEFF Research Database (Denmark)

Emanuelli, Brice; Glondu, Murielle; Filloux, Chantal

2004-01-01

insulin signaling is required for the optimal beta-cell function, we assessed the effect of IL-1beta on the insulin pathway in a rat pancreatic beta-cell line. We show that IL-1beta decreases insulin-induced tyrosine phosphorylation of the insulin receptor (IR) and insulin receptor substrate (IRS...

Molecular analysis of the beta-thalassemia phenotype associated with inheritance of hemoglobin E (alpha 2 beta2(26)Glu leads to Lys).

OpenAIRE

Benz, E J; Berman, B W; Tonkonow, B L; Coupal, E; Coates, T; Boxer, L A; Altman, A; Adams, J G

1981-01-01

Inheritance of the gene for betaE-globin is associated with hypochromia and microcytosis, reminiscent of typical heterozygous beta-thalassemia. Patients with hemoglobin (Hb)E-beta-thalassemia exhibit clinical phenotypes of severe beta-thalassemia, a circumstance not encountered in other compound heterozygous states for structural beta-chain mutations and beta-thalassemia. We have analyzed the kinetics of globin synthesis and the levels of globin messenger (m) RNA accumulation in patients with...

Double beta decays studied by β-γ spectroscopy with a drift chamber

International Nuclear Information System (INIS)

Okada, K.; Ejiri, H.; Shibata, T.

1986-01-01

A large scale ultra low background β-γ spectrometer ELEGANTS-V for studying double beta decays(ββ) of /sup 100/Mo and/or /sup 150/Nd is designed and is now under construction. It consists of drift chambers for identification of tracks and vertex of two β-rays, thin NaI(T1) or plastic scintillators for β-rays energy and NaI(T1) counters for γ- and cosmic-rays. Specifications of the spectrometer; energy resolution, detection efficiency, possible background counting rate and available ββ sources, have been evaluated. The spectrometer has extremely high sensitivities of the neutrinoless ββ decays (0νββ), two neutrino ββ decays (2νββ) and neutrinoless ββ decays followed one boson (Majoron). It may detect 0νββ decays with half lives up to T/sub 1/2/ = 1.2- 1.7 . 10/sup 23/ year. This limit corresponds to one part of million for the Majoran neutrino mass in units of the electron mass and for the right-handed weak current in units of the left handed one

The refined 2.0 A X-ray crystal structure of the complex formed between bovine beta-trypsin and CMTI-I, a trypsin inhibitor from squash seeds (Cucurbita maxima). Topological similarity of the squash seed inhibitors with the carboxypeptidase A inhibitor from potatoes.

Science.gov (United States)

Bode, W; Greyling, H J; Huber, R; Otlewski, J; Wilusz, T

1989-01-02

The stoichiometric complex formed between bovine beta-trypsin and the Cucurbita maxima trypsin inhibitor I (CMTI-I) was crystallized and its X-ray crystal structure determined using Patterson search techniques. Its structure has been crystallographically refined to a final R value of 0.152 (6.0-2.0 A). CMTI-I is of ellipsoidal shape; it lacks helices or beta-sheets, but consists of turns and connecting short polypeptide stretches. The disulfide pairing is CYS-3I-20I, Cys-10I-22I and Cys-16I-28I. According to the polypeptide fold and disulfide connectivity its structure resembles that of the carboxypeptidase A inhibitor from potatoes. Thirteen of the 29 inhibitor residues are in direct contact with trypsin; most of them are in the primary binding segment Val-2I (P4)-Glu-9I (P4') which contains the reactive site bond Arg-5I-Ile-6I and is in a conformation observed also for other serine proteinase inhibitors.

Automation of electrostatic and magnetic beta-spectrometers; Avtomatizatsiya ehlektrostaticheskogo i magnitnogo {beta}-spektrometra

Energy Technology Data Exchange (ETDEWEB)

Sidorov, V T; Petev, P A

1996-12-31

Paper describes control units of voltage and current NM respectively, for electrostatic and magnetic beta-spectrometers. These units may be designed on the basis of either SPELMAN company voltage devider ensuring 0.5 accuracy or using a computer modification of feedback. Software for automated electrostatic beta-spectrometer made according to CAMAC standards is considered. 5 figs.

Thermally Induced Alpha-Helix to Beta-Sheet Transition in Regenerated Silk Fibers and Films

Energy Technology Data Exchange (ETDEWEB)

Drummy,L.; Phillips, D.; Stone, M.; Farmer, B.; Naik, R.

2005-01-01

The structure of thin films cast from regenerated solutions of Bombyx mori cocoon silk in hexafluoroisopropyl alcohol (HFIP) was studied by synchrotron X-ray diffraction during heating. A solid-state conformational transition from an alpha-helical structure to the well-known beta-sheet silk II structure occurred at a temperature of approximately 140 degrees C. The transition appeared to be homogeneous, as both phases do not coexist within the resolution of the current study. Modulated differential scanning calorimetry (DSC) of the films showed an endothermic melting peak followed by an exothermic crystallization peak, both occurring near 140 degrees C. Oriented fibers were also produced that displayed this helical molecular conformation. Subsequent heating above the structural transition temperature produced oriented beta-sheet fibers very similar in structure to B. mori cocoon fibers. Heat treatment of silk films at temperatures well below their degradation temperature offers a controllable route to materials with well-defined structures and mechanical behavior.

Characterization of an extrapolation chamber in a 90Sr/90Y beta radiation field

International Nuclear Information System (INIS)

Oramas Polo, I.; Tamayo Garcia, J. A.

2015-01-01

The extrapolation chamber is a parallel plate chamber and variable volume based on the Bragg-Gray theory. It determines in absolute mode, with high accuracy the dose absorbed by the extrapolation of the ionization current measured for a null distance between the electrodes. This camera is used for dosimetry of external beta rays for radiation protection. This paper presents the characterization of an extrapolation chamber in a 90 Sr/ 90 Y beta radiation field. The absorbed dose rate to tissue at a depth of 0.07 mm was calculated and is (0.13206±0.0028) μGy. The extrapolation chamber null depth was determined and its value is 60 μm. The influence of temperature, pressure and humidity on the value of the corrected current was also evaluated. Temperature is the parameter that has more influence on this value and the influence of pressure and the humidity is not very significant. Extrapolation curves were obtained. (Author)

Experiments on double beta decay

Energy Technology Data Exchange (ETDEWEB)

Busto, J [Neuchatel Univ. (Switzerland). Inst. de Physique

1996-11-01

The Double Beta Decay, and especially ({beta}{beta}){sub 0{nu}} mode, is an excellent test of Standard Model as well as of neutrino physics. From experimental point of view, a very large number of different techniques are or have been used increasing the sensitivity of this experiments quite a lot (the factor of 10{sup 4} in the last 20 years). In future, in spite of several difficulties, the sensitivity would be increased further, keeping the interest of this very important process. (author) 4 figs., 5 tabs., 21 refs.

Maternal and cord plasma concentrations of beta-lipotrophin, beta-endorphin and gamma-lipotrophin at delivery; effect of analgesia.

Science.gov (United States)

Browning, A J; Butt, W R; Lynch, S S; Shakespear, R A; Crawford, J S

1983-12-01

Maternal venous plasma concentrations of beta-LPH, beta-EP and gamma-LPH were compared in (i) patients undergoing vaginal delivery, 11 with an epidural block and 13 with pethidine and nitrous oxide or no analgesics; (ii) patients delivered by caesarean section, 7 under epidural block and 8 under general anaesthesia. Patients delivered by either method under epidural block had significantly lower levels of all three peptides than those receiving no epidural. There were significant negative correlations between umbilical vein beta-LPH, beta-EP and gamma-LPH concentrations and umbilical artery pH and positive correlations between beta-LPH and beta-EP but not gamma-LPH and cord PCO2 in 29 patients. There was no relation between cord levels of any of the three peptides and the method of analgesia or the route of delivery. Although concentrations of all three peptides were closely correlated to one another in either maternal or cord plasma, there was no relationship between maternal and fetal levels.

Abstraction Mechanisms in the BETA Programming Language

DEFF Research Database (Denmark)

Kristensen, Bent Bruun; Madsen, Ole Lehrmann; Møller-Pedersen, Birger

1983-01-01

. It is then necessary that the abstraction mechanisms are powerful in order to define more specialized constructs. BETA is an object oriented language like SIMULA 67 ([SIMULA]) and SMALLTALK ([SMALLTALK]). By this is meant that a construct like the SIMULA class/subclass mechanism is fundamental in BETA. In contrast......]) --- covering both data, procedural and control abstractions, substituting constructs like class, procedure, function and type. Correspondingly objects, procedure activation records and variables are all regarded as special cases of the basic building block of program executions: the entity. A pattern thus......The BETA programming language is developed as part of the BETA project. The purpose of this project is to develop concepts, constructs and tools in the field of programming and programming languages. BETA has been developed from 1975 on and the various stages of the language are documented in [BETA...

Prediction of beta-turns with learning machines.

Science.gov (United States)

Cai, Yu-Dong; Liu, Xiao-Jun; Li, Yi-Xue; Xu, Xue-biao; Chou, Kuo-Chen

2003-05-01

The support vector machine approach was introduced to predict the beta-turns in proteins. The overall self-consistency rate by the re-substitution test for the training or learning dataset reached 100%. Both the training dataset and independent testing dataset were taken from Chou [J. Pept. Res. 49 (1997) 120]. The success prediction rates by the jackknife test for the beta-turn subset of 455 tetrapeptides and non-beta-turn subset of 3807 tetrapeptides in the training dataset were 58.1 and 98.4%, respectively. The success rates with the independent dataset test for the beta-turn subset of 110 tetrapeptides and non-beta-turn subset of 30,231 tetrapeptides were 69.1 and 97.3%, respectively. The results obtained from this study support the conclusion that the residue-coupled effect along a tetrapeptide is important for the formation of a beta-turn.

Colour-producing [beta]-keratin nanofibres in blue penguin (Eudyptula minor) feathers

Energy Technology Data Exchange (ETDEWEB)

D; Alba, Liliana; Saranathan, Vinodkumar; Clarke, Julia A.; Vinther, Jakob A.; Prum, Richard O.; Shawkey, Matthew D. (Yale); (Akron); (Texas)

2012-03-26

The colours of living organisms are produced by the differential absorption of light by pigments (e.g. carotenoids, melanins) and/or by the physical interactions of light with biological nanostructures, referred to as structural colours. Only two fundamental morphologies of non-iridescent nanostructures are known in feathers, and recent work has proposed that they self-assemble by intracellular phase separation processes. Here, we report a new biophotonic nanostructure in the non-iridescent blue feather barbs of blue penguins (Eudyptula minor) composed of parallel {beta}-keratin nanofibres organized into densely packed bundles. Synchrotron small angle X-ray scattering and two-dimensional Fourier analysis of electron micrographs of the barb nanostructure revealed short-range order in the organization of fibres at the appropriate size scale needed to produce the observed colour by coherent scattering. These two-dimensional quasi-ordered penguin nanostructures are convergent with similar arrays of parallel collagen fibres in avian and mammalian skin, but constitute a novel morphology for feathers. The identification of a new class of {beta}-keratin nanostructures adds significantly to the known mechanisms of colour production in birds and suggests additional complexity in their self-assembly.

Ranking beta sheet topologies of proteins

DEFF Research Database (Denmark)

Fonseca, Rasmus; Helles, Glennie; Winter, Pawel

2010-01-01

One of the challenges of protein structure prediction is to identify long-range interactions between amino acids. To reliably predict such interactions, we enumerate, score and rank all beta-topologies (partitions of beta-strands into sheets, orderings of strands within sheets and orientations...... of paired strands) of a given protein. We show that the beta-topology corresponding to the native structure is, with high probability, among the top-ranked. Since full enumeration is very time-consuming, we also suggest a method to deal with proteins with many beta-strands. The results reported...... in this paper are highly relevant for ab initio protein structure prediction methods based on decoy generation. The top-ranked beta-topologies can be used to find initial conformations from which conformational searches can be started. They can also be used to filter decoys by removing those with poorly...

Strain-dependent differences in sensitivity of rat beta-cells to interleukin 1 beta in vitro and in vivo

DEFF Research Database (Denmark)

Reimers, J I; Andersen, H U; Mauricio, D

1996-01-01

/kg) or vehicle for 5 days. All the strains investigated were susceptible to IL-1 beta-induced changes in body weight, food intake, temperature, and plasma glucagon and corticosterone. However, IL-1 beta induced hyperglycemia and impairment of beta-cell glucose responsiveness in WK/Mol and LS/Mol rats...

Gamma irradiation effect and time of storage on the beta-carotene rate of dehydrated parsley; Efeito da irradiacao gama e tempo de estoque no teor de beta-caroteno de salsa desidratada

Energy Technology Data Exchange (ETDEWEB)

Sebastiao, K.I.; Romanelli, M.F.; Leite, Q.R.; Koseki, P.M.; Hamasaki, K.; Villavicencio, A.L.C.H. [Instituto de Pesquisas Energeticas e Nucleares (IPEN), Sao Paulo, SP (Brazil). Centro de Tecnologia das Radiacoes. Lab. de Analise e Deteccao de Alimentos]. E-mail: villavic@net.ipen.br; Almeida-Muradian, L.B. [Sao Paulo Univ., SP (Brazil). Faculdade de Ciencias Farmaceuticas]. E-mail: ligiabi@usp.br

2000-07-01

The A vitamin is an essential nutrient for men. Therefore, this vitamin or one of its precursors must be ingested for a healthful diet. The carotenoids are also called pro-vitamin A. As any another carotenoid, the {beta}-carotene has a structure with many unsaturations, conferring certain instability. It can be modified and even destroyed for acid, light, heat, oxygen; the formation of cis-trans isomers, reduction of its color and its pro-vitacimin A activity reduction can happen. Those alterations can occur during the processing or storage of the food. The use of the ionizing radiation is a kind of food processing that consists of the use of the high energy of the gamma ray or accelerates electrons, capable to ionize molecules. The carotenoids are considered by literature little sensible to the irradiation. It is suggested doses of 1 to 10 kGy in the irradiation of spices, dehydrated condiments and vegetables. These doses are enough to eliminate or to reduce pathogenic microorganisms and insects, to magnify the time of useful life and still substitute the use of chemical fumigants. They also reveal adequate to the organoleptic aspect, not affecting its flavor and smell. This study had as objective to search the different {beta}-carotene levels in samples of dehydrated parsley submitted to the radiation of {sup 60}Co and stored by 6 months. The results gotten in first analysis had not indicated difference significant statistics in {beta}-carotene rate between the controlled sample and the radiated one. After 6 months of storage, were verified that the {beta}-carotene rate had fallen for the half in both samples.