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Sample records for 131mxe 133mxe 133xe

  1. Evaluation of 133Xe and 133Xe(m) decay data.

    PubMed

    Galán, M

    2009-01-01

    This paper presents the decay data evaluation of (133)Xe and (133)Xe(m), which includes the most recent available data, such as half-life results and gamma-ray intensities that have not been considered in previous evaluations. The adopted internal conversion coefficients (ICC) have been calculated using the 'Frozen Orbital' approximation and are compared here to recent measured values. Recent Q-value tabulations, recommended gamma-ray energies for calibrations, as well as new evaluated gamma-ray intensities for the 81- and 233-keV lines (37.0 (3)% and 10.16 (13)%, respectively) are also presented in this evaluation. Atomic radiation emission probabilities (X-ray and Auger electron) associated with nuclear radiations have been deduced and also included in this work. PMID:18805017

  2. Dose dependence of the production yield of endohedral 133Xe-fullerene by ion implantation

    NASA Astrophysics Data System (ADS)

    Watanabe, S.; Ishioka, N. S.; Shimomura, H.; Muramatsu, H.; Sekine, T.

    2003-05-01

    The production yield of endohedral 133Xe-fullerene by ion implantation has been studied by taking advantage of the radioactivity of 133Xe. Fullerene targets, which were produced by vacuum evaporation of C 60 or C 70 on a Ni backing, were bombarded with 30-38 keV 133Xe ions by using an isotope separator at doses ranging from 1 × 10 12 to 1 × 10 14 cm -2. The production yield of endohedral 133Xe-fullerene was determined by an high performance liquid chromatography analysis following the dissolution of the targets in o-dichlorobenzene. It was found that the production yield decreased with increasing dose and incident energy, and the production yield of 133Xe@C 70 was higher than that of 133Xe@C 60 for the same dose and incident energy. Those production yields are discussed in connection with amorphization of fullerene molecules in collisions with 133Xe ions.

  3. Response of Panasonic dosimeters to submersion exposure by 133Xe.

    PubMed

    Hoffman, J M; Catchen, G L

    1990-01-01

    The dose response to 133Xe radiation of several types of Panasonic 800 series thermoluminescent dosimeters (TLD) were evaluated. The dosimeters were exposed by submersion in 133Xe gas. The relative sensitivities of the lithium borate and the calcium sulfate phosphors were determined for several configurations. The TLDs were exposed in the holders (as the devices came from the vendor) with various shields covering the elements, and they were exposed with the TLDs removed from the holders. Some dosimeters were exposed, both in holders and out of holders (TL insert only configuration), both in plastic bags and free in air. For the in-holder configuration, the responses of the heavily shielded (greater than 170 mg cm-2) elements were used to obtain the photon dose-rate component, and the responses of the lightly shielded (less than 13 mg cm-2) element were used to obtain the beta component. Similarly, for the insert-only configurations, the observed over-response of the calcium sulfate phosphors to low-energy photons could be used to separate the beta dose rate component. By using the calculated beta doses, correction factors were determined for the apparent under-responses of the elements to beta radiation. The results of both methods are consistent. These results also suggest that the beta component could be used in environmental monitoring as a more sensitive means to determine 133Xe activities in clouds and to separate some of the effects of submersion exposure from those of distant exposure.

  4. Evaluation of 133Xe radiation exposure dosimetry for workers in nuclear medicine laboratories.

    PubMed

    Piltingsrud, H V; Gels, G L

    1982-06-01

    Evaluation of past studies of 133Xe dosimetry and nuclear medicine laboratory air concentrations of 133Xe indicates that significant levels of 133Xe may exist in routine operational environments of a nuclear medicine laboratory. This leads to the question of whether present health physics radiation control methods are adequate to keep occupational personnel exposures within acceptable levels. It would appear that if personnel dosimeters (film and TLD badges) respond properly to the radiation of 133Xe, normal health physics control procedures are probably adequate. If they do not respond adequately, personnel exposures may exceed recommended levels and special instrumentation or administrative procedures are called for. Therefore, the first step in studying potential problems in the subject area is to evaluate the response of a variety of personnel radiation dosimeters to 133Xe. This paper describes the methods and materials used to expose personnel dosimeters to known amounts of 133Xe radiations in an exposure chamber constructed at the BRH Nuclear Medicine Laboratory. Also presented are calculated values for Dose Equivalents (D.E.) in a phantom from external radiation resulting from immersion in clouds having a constant concentration of 133Xe but varying cloud radii. This implies the relative importance of the beta and the X + gamma radiation responses of the personnel dosimeters under various exposure conditions. Results of this study indicate that none of the dosimeter systems evaluated provide adequate performance for use as a primary indicator of the D.E. resulting from 133Xe radiations for a worker in a nuclear medicine laboratory, and that personnel dosimetry considerations in 133Xe-containing atmospheres are very dependent on the radii of the 133Xe clouds.

  5. Cerebral blood flow studied by /sup 133/Xe inhalation technique in parkinsonism: loss of hyperfrontal pattern

    SciTech Connect

    Bes, A.; Gueell, A.; Fabre, N.; Dupui, P.; Victor, G.; Geraud, G.

    1983-03-01

    Cerebral blood flow (grey matter flow) in parkinsonism requires further investigation. The noninvasive method of /sup 133/Xe inhalation permits study of larger numbers of subjects than previously used invasive techniques such as the intracarotid /sup 133/Xe injection method. Measurements were made in this laboratory in 30 subjects having Parkinson's disease. Mean hemispheric blood flow (F1) values were 70.4 +/- 9.3 ml/100 g/min, compared to 76.3 for a group of age-matched normal subjects, which is a decrease of -7.8%. The most striking difference was the loss of the hyperfrontal distribution in parkinsonism. The prefrontal F1 values were only 1.8% greater than the hemisphere grey matter flow, compared with 8.5% in controls of a similar age group.

  6. Prospective use of xenon /sup 133/Xe clearance for amputation level selection

    SciTech Connect

    Moore, W.S.; Henry, R.E.; Malone, J.M.; Daly, M.J.; Patton, D.; Childers, S.J.

    1981-01-01

    Xenon /sup 133/Xe clearance was used to select the most distal amputation level that would allow sufficient blood flow for healing. Capillary blood flow was first measured at the most distal potential amputation level, then at successive proximal levels until an amputation site was found that had a capillary skin blood flow rate greater than or equal to 2.6 mL/min/100 g of tissue. Xenon /sup 133/Xe in saline was injected intracutaneously at each level, and flow rates were determined using a gamma camera interfaced with a computer system programmed for the Ketty-Schmidt formula modified for capillary blood flow. There were 45 cases, including one toes, six transmetatarsal, five Syme's, 25 below-knee, four knee disarticulation, three above-knee, and one hip disarticulation amputation. All amputations in patients with flow rates exceeding 2.4 mL/min/100 g of tissue healed, with two exceptions.

  7. Detection of (133)Xe from the Fukushima nuclear power plant in the upper troposphere above Germany.

    PubMed

    Simgen, Hardy; Arnold, Frank; Aufmhoff, Heinfried; Baumann, Robert; Kaether, Florian; Lindemann, Sebastian; Rauch, Ludwig; Schlager, Hans; Schlosser, Clemens; Schumann, Ulrich

    2014-06-01

    After the accident in the Japanese Fukushima Dai-ichi nuclear power plant in March 2011 large amounts of radioactivity were released and distributed in the atmosphere. Among them were also radioactive noble gas isotopes which can be used as tracers to test global atmospheric circulation models. This work presents unique measurements of the radionuclide (133)Xe from Fukushima in the upper troposphere above Germany. The measurements involve air sampling in a research jet aircraft followed by chromatographic xenon extraction and ultra-low background gas counting with miniaturized proportional counters. With this technique a detection limit of the order of 100 (133)Xe atoms in liter-scale air samples (corresponding to about 100 mBq/m(3)) is achievable. Our results provide proof that the (133)Xe-rich ground level air layer from Fukushima was lifted up to the tropopause and distributed hemispherically. Moreover, comparisons with ground level air measurements indicate that the arrival of the radioactive plume at high altitude over Germany occurred several days before the ground level plume. PMID:24607612

  8. Detection of (133)Xe from the Fukushima nuclear power plant in the upper troposphere above Germany.

    PubMed

    Simgen, Hardy; Arnold, Frank; Aufmhoff, Heinfried; Baumann, Robert; Kaether, Florian; Lindemann, Sebastian; Rauch, Ludwig; Schlager, Hans; Schlosser, Clemens; Schumann, Ulrich

    2014-06-01

    After the accident in the Japanese Fukushima Dai-ichi nuclear power plant in March 2011 large amounts of radioactivity were released and distributed in the atmosphere. Among them were also radioactive noble gas isotopes which can be used as tracers to test global atmospheric circulation models. This work presents unique measurements of the radionuclide (133)Xe from Fukushima in the upper troposphere above Germany. The measurements involve air sampling in a research jet aircraft followed by chromatographic xenon extraction and ultra-low background gas counting with miniaturized proportional counters. With this technique a detection limit of the order of 100 (133)Xe atoms in liter-scale air samples (corresponding to about 100 mBq/m(3)) is achievable. Our results provide proof that the (133)Xe-rich ground level air layer from Fukushima was lifted up to the tropopause and distributed hemispherically. Moreover, comparisons with ground level air measurements indicate that the arrival of the radioactive plume at high altitude over Germany occurred several days before the ground level plume.

  9. Intraoperative sup 133 Xe cerebral blood flow measurements by intravenous versus intracarotid methods

    SciTech Connect

    Young, W.L.; Prohovnik, I.; Schroeder, T.; Correll, J.W.; Ostapkovich, N. )

    1990-10-01

    To document the comparability of cerebral blood flow (CBF) values determined by quantification of 133Xe washout after either intravenous or intracarotid administration, 12 patients undergoing elective carotid endarterectomy anesthetized with N2O/O2 and either isoflurane or halothane were studied. Scintillation counters were placed over the middle cerebral artery territory ipsilateral to the operated carotid artery. CBF was measured by the intravenous method during dissection of the carotid sheath and was calculated as the initial slope index from head washout curves collected for 11 min after injection of 10-20 mCi 133Xe in saline into a large vein. Immediately prior to carotid occlusion, CBF was determined by direct injection of 1 mCi 133Xe in saline into either the internal carotid artery or the common carotid artery with the external carotid artery occluded. For the intracarotid injections, the initial slope was calculated from the 1st min of washout. Data were analyzed by linear regression and analysis of variance. Values are expressed as mean +/- SD. The mean CBF for intravenous and intracarotid methods were both 29 +/- 10 ml.100 g-1.min-1. The correlation between CBF measured by intravenous and intracarotid methods was excellent and was described by the line y = x + 0.6, r = 0.92. We conclude that in the flow range studied, the intravenous technique may be applied to measure CBF in physiologically stable situations in which direct intracarotid injection is not feasible.

  10. Response of Panasonic dosimeters to submersion exposure by sup 133 Xe

    SciTech Connect

    Hoffman, J.M.; Catchen, G.L. )

    1990-01-01

    The dose response to {sup 133}Xe radiation of several types of Panasonic 800 series thermoluminescent dosimeters (TLD) were evaluated. The dosimeters were exposed by submersion in {sup 133}Xe gas. The relative sensitivities of the lithium borate and the calcium sulfate phosphors were determined for several configurations. The TLDs were exposed in the holders (as the devices came from the vendor) with various shields covering the elements, and they were exposed with the TLDs removed from the holders. Some dosimeters were exposed, both in holders and out of holders (TL insert only configuration), both in plastic bags and free in air. For the in-holder configuration, the responses of the heavily shielded (greater than 170 mg cm-2) elements were used to obtain the photon dose-rate component, and the responses of the lightly shielded (less than 13 mg cm-2) element were used to obtain the beta component. Similarly, for the insert-only configurations, the observed over-response of the calcium sulfate phosphors to low-energy photons could be used to separate the beta dose rate component. By using the calculated beta doses, correction factors were determined for the apparent under-responses of the elements to beta radiation. The results of both methods are consistent. These results also suggest that the beta component could be used in environmental monitoring as a more sensitive means to determine {sup 133}Xe activities in clouds and to separate some of the effects of submersion exposure from those of distant exposure.

  11. Penile xenon (/sup 133/Xe) washout: a rapid method of screening for vasculogenic impotence

    SciTech Connect

    Nseyo, U.O.; Wilbur, H.J.; Kang, S.A.; Flesh, L.; Bennett, A.H.

    1984-01-01

    The radioactive inert gas xenon (/sup 133/Xe) is a well-established isotopic indicator used to assess vascular status in many organ systems. Xenon-133 was used to evaluate male impotence. Xenon-133 was injected subcutaneously at the level of the coronal sulcus in the detumescent state. Using the gamma camera, sequential images were obtained and computer-generated curves calculated. The clearance time for 50 per cent washout of the injected /sup 133/Xe (T1/2) was then calculated for each patient, as well as a control group. Preliminary findings indicate a correlation with such established techniques of evaluating erectile impotence as history, physical examination, penile pulse Doppler tracings, and brachial-penile blood pressure index. The xenon-133 washout study was a rapid, minimally invasive, reproducible, and cost-effective method of screening those impotent patients for vasculogenic etiology of their erectile impotence. We recommend the addition of this method to the surgeon engaged in the care of impotent males.

  12. Measured absorbed dose rates from semi-infinite hemispherical volumes of 133Xe.

    PubMed

    Munyon, W J; Barber, D E; Howley, J R

    1986-07-01

    Surface absorbed dose rates from different hemispheric volumes of 133Xe have been measured directly with an extrapolation chamber. The results indicate that a linear relationship exists between the radius of the cloud volume and the surface absorbed dose rate for radii between 0 and 23 cm. If cloud volumes with radii larger than 23 cm are taken to be infinite with respect to the range of the charged particles emitted, the absorbed dose rate calculated based on that assumption will be within the uncertainty of any measurement of absorbed dose rate that might be made. For hemispheric volumes having radii less than or equal to 23 cm, the surface absorbed dose rate in tissue-equivalent material, in mGy h-1, is approximated (+/- 20%) by the product of [1.30 mGy h-1 cm-1 kBq-1 cm3] X [cloud radius, cm] X [cloud activity concentration, kBq cm-3].

  13. Atmospheric transport modelling of time resolved 133Xe emissions from the isotope production facility ANSTO, Australia.

    PubMed

    Schöppner, M; Plastino, W; Hermanspahn, N; Hoffmann, E; Kalinowski, M; Orr, B; Tinker, R

    2013-12-01

    The verification of the Comprehensive Nuclear-Test Ban Treaty (CTBT) relies amongst other things on the continuous and worldwide monitoring of radioxenon. The characterization of the existing and legitimate background, which is produced mainly by nuclear power plants and isotope production facilities, is of high interest to improve the capabilities of the monitoring network. However, the emissions from legitimate sources can usually only be estimated. For this paper historic source terms of (133)Xe emissions from the isotope production facility at ANSTO, Sydney, Australia, have been made available in a daily resolution. Based on these high resolution data, different source term sets with weekly, monthly and yearly time resolution have been compiled. These different sets are then applied together with atmospheric transport modelling (ATM) to predict the concentration time series at two radioxenon monitoring stations. The results are compared with each other in order to examine the improvement of the prediction capability depending on the used time resolution of the most dominant source term in the region.

  14. A semiconductor silicon PIN diode matrix detector for measurement of 133Xe washout in small regional skin areas.

    PubMed

    Jensen, J H; Sørensen, J L; Hauge, E N; Sejrsen, P; Bojsen, J

    1993-05-01

    Local variations in microvascularization are expected in lesions and lesion-free skin of patients with pressure sores. To investigate these variations, methods for studies of the regional blood flow rate within small skin areas are needed. Regional blood flow can be estimated by measuring the washout of 133Xe from the tissue. This study describes a 2 x 12 Si PIN diode matrix detector capable of 133Xe detection, and equipped with a collimator to improve the spatial resolution. Thus the regional blood flow in subcutaneous skin areas down to about 2 cm2 can be investigated when the atraumatic epicutaneous labelling technique is used. The capability of the matrix detector and its collimator is described by laboratory investigations. In pilot investigations three normal subjects and three paraplegics with pressure sores were studied. In each individual study the detector matrix was divided into six square areas containing four diode detectors each. Thus six 133Xe disappearance rate constants from adjacent subcutaneous tissue could be determined simultaneously. PMID:8334415

  15. Cerebral hemodynamics in normal-pressure hydrocephalus. Evaluation by 133Xe inhalation method and dynamic CT study

    SciTech Connect

    Tamaki, N.; Kusunoki, T.; Wakabayashi, T.; Matsumoto, S.

    1984-09-01

    Cerebral hemodynamics in 31 patients with suspected normal-pressure hydrocephalus were studied by means of the xenon-133 (133Xe) inhalation method and on dynamic computerized tomography (CT) scanning. Cerebral blood flow (CBF) is reduced in all patients with dementia. Hypoperfusion was noted in a frontal distribution in these patients compared with normal individuals. There was no difference in CBF patterns between patients with good and those with poor outcome. The CBF was increased following cerebrospinal fluid (CSF) shunting in patients who responded to that procedure: increase in flow correlated with clinical improvement, frontal and temporal lobe CBF was most markedly increased, and the CBF pattern became normal. In contrast, CBF was decreased after shunt placement in patients who were considered to have suffered from degenerative dementia, as evidenced by non-response to shunting. Dynamic computerized tomography studies demonstrated that patients with a good outcome showed a postoperative reduction in mean transit time of contrast material, most prominent in the frontal and temporal gray matter, and slight in the deep frontal structures, but not in the major cerebral vessels. Patients with poor outcome after shunting, however, had an increase in transit time in all regions. This corresponded well with the results as determined by the 133Xe inhalation method.

  16. [Evaluation of gamma camera collimator for regional cerebral blood flow measurements using a 133Xe inhalation method].

    PubMed

    Saegusa, K; Arimizu, N; Uematsu, S

    1984-09-01

    In the measurements of regional cerebral blood flow (rCBF) using inhalation of 133Xe gas, the activity present is generally limited in lower levels than those of usual brain scintigraphy. Measurements with low count-rate are usually resulted in diminishing the accuracies of results obtained. Therefore, it is necessary to make measurements using a high sensitive collimator for getting as much count-rate as possible when a gamma camera is used. The relationships among sensitivity and structures of multi-parallel collimator were mathematically analyzed. The results of analysis suggested that sensitivity usually increased by using a collimator with holes of reduced height and diameter. A prototype multi-parallel collimator with holes of low height and small diameter was made in our laboratory for testing sensitivity and resolution. The collimator possessing 1141 holes of 6 mm phi in hole diameter, 1.5 cm is hole height and septal thickness of 1 mm lead showed 24 times more sensitive than those of a general all purpose collimator supplied by the manufacturer. However, resolution measured in FWHM was of 9 to 14 mm at the collimator face and of 29 to 38 mm at 5 cm from the face. The results indicated that this collimator was useful enough in rCBF measurements with 133Xe inhalation using a gamma camera. The mathematical analysis however, suggested that optimum collimator for rCBF measurements was approximate 4.5 mm phi in hole diameter and 1.0 cm in hole height. PMID:6515050

  17. Relationship of 133Xe cerebral blood flow to middle cerebral arterial flow velocity in men at rest

    NASA Technical Reports Server (NTRS)

    Clark, J. M.; Skolnick, B. E.; Gelfand, R.; Farber, R. E.; Stierheim, M.; Stevens, W. C.; Beck, G. Jr; Lambertsen, C. J.

    1996-01-01

    Cerebral blood flow (CBF) was measured by 133Xe clearance simultaneously with the velocity of blood flow through the left middle cerebral artery (MCA) over a wide range of arterial PCO2 in eight normal men. Average arterial PCO2, which was varied by giving 4% and 6% CO2 in O2 and by controlled hyperventilation on O2, ranged from 25.3 to 49.9 mm Hg. Corresponding average values of global CBF15 were 27.2 and 65.0 ml 100 g min-1, respectively, whereas MCA blood-flow velocity ranged from 42.8 to 94.2 cm/s. The relationship of CBF to MCA blood-flow velocity over the imposed range of arterial PCO2 was described analytically by a parabola with the equation: CBF = 22.8 - 0.17 x velocity + 0.006 x velocity2 The observed data indicate that MCA blood-flow velocity is a useful index of CBF response to change in arterial PCO2 during O2 breathing at rest. With respect to baseline values measured while breathing 100% O2 spontaneously, percent changes in velocity were significantly smaller than corresponding percent changes in CBF at increased levels of arterial PCO2 and larger than CBF changes at the lower arterial PCO2. These observed relative changes are consistent with MCA vasodilation at the site of measurement during exposure to progressive hypercapnia and also during extreme hyperventilation hypocapnia.

  18. Concentration Independent Calibration of β-γ Coincidence Detector Using 131mXe and 133Xe

    SciTech Connect

    McIntyre, Justin I.; Cooper, Matthew W.; Carman, April J.; Bowyer, Ted W.; Day, Anthony R.; Haas, Derek A.; Hayes, James C.; Heimbigner, Tom R.; Hubbard, Charles W.; Litke, Kevin E.; Ripplinger, Michael D.; Schrom, Brian T.; Suarez, Reynold

    2009-12-01

    Absolute efficiency calibration of radiometric detectors is frequently difficult and requires careful detector modeling and accurate knowledge of the radioactive source used. In the past we have calibrated the b-g coincidence detector of the Automated Radioxenon Sampler/Analyzer (ARSA) using a variety of sources and techniques which have proven to be less than desirable.[1] A superior technique has been developed that uses the conversion-electron (CE) and x-ray coincidence of 131mXe to provide a more accurate absolute gamma efficiency of the detector. The 131mXe is injected directly into the beta cell of the coincident counting system and no knowledge of absolute source strength is required. In addition, 133Xe is used to provide a second independent means to obtain the absolute efficiency calibration. These two data points provide the necessary information for calculating the detector efficiency and can be used in conjunction with other noble gas isotopes to completely characterize and calibrate the ARSA nuclear detector. In this paper we discuss the techniques and results that we have obtained.

  19. Sources of variability of resting cerebral blood flow in healthy subjects: a study using 133Xe SPECT measurements

    PubMed Central

    Henriksen, Otto M; Kruuse, Christina; Olesen, Jes; Jensen, Lars T; Larsson, Henrik B W; Birk, Steffen; Hansen, Jakob M; Wienecke, Troels; Rostrup, Egill

    2013-01-01

    Measurements of cerebral blood flow (CBF) show large variability among healthy subjects. The aim of the present study was to investigate the relative effect of established factors influencing CBF on the variability of resting CBF. We retrospectively analyzed spontaneous variability in 430 CBF measurements acquired in 152 healthy, young subjects using 133Xe single-photon emission computed tomography. Cerebral blood flow was correlated positively with both end-tidal expiratory PCO2 (PETCO2) and female gender and inversely with hematocrit (Hct). Between- and within-subject CO2 reactivity was not significantly different. Including PETCO2, Hct and gender in the model reduced between-subject and within-subject variance by 14% and 13.5%, respectively. Within-subject variability was mainly influenced by PETCO2 and between-subject variability mostly by Hct, whereas gender appeared to be of little added value when Hct was also accounted for. The present study confirms large between-subject variability in CBF measurements and that gender, Hct, and PETCO2 explain only a small part of this variability. This implies that a large fraction of CBF variability may be due to unknown factors such as differences in neuron density or metabolism that could be subject for further studies. PMID:23403374

  20. Adsorption and desorption of noble gases on activated charcoal: I. 133Xe studies in a monolayer and packed bed.

    PubMed

    Scarpitta, S C; Harley, N H

    1990-10-01

    Detailed desorption studies using petroleum-based activated charcoals were conducted in monolayers and packed beds. Less extensive studies were conducted on several other types of charcoal. Kinetic studies, using 133Xe, demonstrated the existence of a micropore volume with entrance capillaries that together determined the response characteristics of charcoal to external concentration gradients of tracer gases. This new two-phase model, composed of micropores and entrance capillaries, describes the desorption dynamics of an adsorbed gas in the presence of water vapor. Condensed water vapor in the entrance capillaries of the charcoal reduced the effective pore radius and increased the diffusion half-time. Water could also adversely affect the integrating capability of the charcoal dramatically if the adsorbed water completely blocked the entrance capillaries. The amount of adsorbed water required to block the capillaries varied with the charcoal type and was termed here as the "break-point." The desorption parameters measured in this work can be used to design an improved passive Rn monitor to effectively integrate during a 3-7 d exposure period by eliminating the adverse effects of water vapor. The improved canister design would provide more accurate and reproducible measurements of indoor Rn concentrations than are currently available. PMID:2398007

  1. /sup 133/Xe blood flow monitoring during arteriovenous malformation resection: a case of intraoperative hyperperfusion with subsequent brain swelling

    SciTech Connect

    Young, W.L.; Solomon, R.A.; Prohovnik, I.; Ornstein, E.; Weinstein, J.; Stein, B.M.

    1988-04-01

    Measurement of regional cerebral blood flow (rCBF) using the i.v. 133Xe technique was carried out during resection of a right temporooccipital arteriovenous malformation (AVM) with ipsilateral middle and posterior cerebral arterial supply. Intraoperatively, a rCBF detector was in place over the right frontotemporal area, about 5 to 6 cm from the border of the AVM. Anesthesia was 0.75% isoflurane in oxygen and nitrous oxide. After dural exposure, the rCBF was 27 ml/100 g/min at a pCO2 of 29 mm Hg and a mean arterial pressure (MAP) of 90 mm Hg. The pCO2 was then elevated to 40 mm Hg, and the rCBF was increased to 55 ml/100 g/min at a MAP of 83 mm Hg. After AVM removal, the rCBF rose to 50 ml/100 g/min at a pCO2 of 27 mm Hg and a MAP of 75 mm Hg. The pCO2 was elevated to 33 mm Hg and the rCBF increased to 86 ml/100 g/min at a MAP of 97 mm Hg. During skin closure, the rCBF was 94 ml/100 g/min at a pCO2 of 26 mm Hg and a MAP of 97 mm Hg. The patient was neurologically normal postoperatively except for a mild, new visual field defect. After 2 to 3 days, the patient gradually developed lethargy, confusion, and nausea with relatively normal blood pressure. An angiogram revealed residual enlargement of the posterior cerebral artery feeding vessel. Computed tomography showed edema extending from the area of AVM resection as far as the frontal region, producing a significant midline shift anteriorly. Intraoperative rCBF monitoring revealed significant hyperperfusion after AVM resection, which was associated with signs and symptoms of the normal perfusion pressure breakthrough syndrome.

  2. Cerebral hemodynamics in patients with moyamoya disease. A study of regional cerebral blood flow by the /sup 133/Xe inhalation method

    SciTech Connect

    Takeuchi, S.; Tanaka, R.; Ishii, R.; Tsuchida, T.; Kobayashi, K.; Arai, H.

    1985-05-01

    Regional cerebral blood flow was measured by the /sup 133/Xe inhalation method in 20 young patients with moyamoya disease and five young healthy volunteers. Most patients showed low values of mean hemispheric blood flow in both hemispheres. Regional cerebral blood flow was at a low value in the upper frontal region and at an almost average value in the posterotemporal and occipital regions, which was different from the ''hyperfrontal'' pattern in healthy volunteers. Regional cerebral blood flow was reduced evenly by hyperventilation. By 5% CO/sub 2/ inhalation, regional cerebral blood flow was increased in the temporooccipital regions and was nearly unchanged or decreased in the frontal region.

  3. Studies on 133Xe wash-out from human skin: quantitative measurements of blood flow in normal and corticosteroid-treated skin.

    PubMed

    Kristensen, J K; Wadskov, S

    1977-04-01

    Blood flow was measured by the 133Xe technique in normal and corticosteroid-treated skin. Epicutaneous and intracutaneous methods of tracer application were compared in normal skin. The two labeling methods were equally suitable for measuring cutaneous blood flow provided calculations in both cases were based on a biexponential resolution of the wash-out curve in its cutaneous and subcutaneous components and provided the traumatic hyperemia phase was considered, when intracutaneous application of the tracer was used. Results were invalidated if calculations were based on initial slope of the wash-out curves.Topical application of beta-methasone valerate in a reduction in cutaneous blood flow as measured by the intracutaneous technique with curve resolution, whereas no effect could be demonstrated when calculations were based on the initial slopes of the curves. The 133Xe technique is a simple and reliable method for measuring cutaneous blood flow, which might prove useful in estimations of penetration ability and potency of topical corticosteroids.

  4. Effects of selected materials and geometries on the beta dose equivalent rate in a tissue equivalent phantom immersed in infinite clouds of 133Xe.

    PubMed

    Piltingsrud, H V; Gels, G L

    1986-06-01

    Most calculations of dose equivalent (D.E.) rates at 70-micron tissue depths in tissue equivalent (T.E.) phantoms from infinite clouds (radius exceeds maximum beta range in air) of 133Xe do not consider the possible effects of clothing overlays. Consequently, a series of measurements were made using a 1-mm-thick plastic scintillation detector assembly mounted in a tissue equivalent (T.E.) phantom with an overlay of 70 micron of T.E. material. This assembly was placed in an infinite cloud containing a known concentration of 133Xe. Material samples were placed at selected distances from the detector phantom, both individually and in various combinations. Pulse-height spectra resulting from beta radiations were converted to relative D.E. rates at a 70-micron tissue depth. The relative D.E. rates were reduced from values with no clothing cover by as little as 45% when placing a single thin nylon cloth 1 cm from the phantom, to 94% for a T-shirt material plus wool material plus denim placed 1/2, 1 and 3 cm, respectively, from the phantom. The results indicate that even loosely fitting clothing can have an important effect on reducing the D.E. rate. Close-fitting clothing appears to provide better protection.

  5. Effects of selected materials and geometries on the beta dose equivalent rate in a tissue equivalent phantom immersed in infinite clouds of 133Xe.

    PubMed

    Piltingsrud, H V; Gels, G L

    1986-06-01

    Most calculations of dose equivalent (D.E.) rates at 70-micron tissue depths in tissue equivalent (T.E.) phantoms from infinite clouds (radius exceeds maximum beta range in air) of 133Xe do not consider the possible effects of clothing overlays. Consequently, a series of measurements were made using a 1-mm-thick plastic scintillation detector assembly mounted in a tissue equivalent (T.E.) phantom with an overlay of 70 micron of T.E. material. This assembly was placed in an infinite cloud containing a known concentration of 133Xe. Material samples were placed at selected distances from the detector phantom, both individually and in various combinations. Pulse-height spectra resulting from beta radiations were converted to relative D.E. rates at a 70-micron tissue depth. The relative D.E. rates were reduced from values with no clothing cover by as little as 45% when placing a single thin nylon cloth 1 cm from the phantom, to 94% for a T-shirt material plus wool material plus denim placed 1/2, 1 and 3 cm, respectively, from the phantom. The results indicate that even loosely fitting clothing can have an important effect on reducing the D.E. rate. Close-fitting clothing appears to provide better protection. PMID:3710789

  6. Effects of selected materials and geometries on the beta dose equivalent rate in a tissue equivalent phantom immersed in infinite clouds of 133Xe

    SciTech Connect

    Piltingsrud, H.V.; Gels, G.L.

    1986-06-01

    Most calculations of dose equivalent (D.E.) rates at 70-micron tissue depths in tissue equivalent (T.E.) phantoms from infinite clouds (radius exceeds maximum beta range in air) of /sup 133/Xe do not consider the possible effects of clothing overlays. Consequently, a series of measurements were made using a 1-mm-thick plastic scintillation detector assembly mounted in a tissue equivalent (T.E.) phantom with an overlay of 70 micron of T.E. material. This assembly was placed in an infinite cloud containing a known concentration of /sup 133/Xe. Material samples were placed at selected distances from the detector phantom, both individually and in various combinations. Pulse-height spectra resulting from beta radiations were converted to relative D.E. rates at a 70-micron tissue depth. The relative D.E. rates were reduced from values with no clothing cover by as little as 45% when placing a single thin nylon cloth 1 cm from the phantom, to 94% for a T-shirt material plus wool material plus denim placed 1/2, 1 and 3 cm, respectively, from the phantom. The results indicate that even loosely fitting clothing can have an important effect on reducing the D.E. rate. Close-fitting clothing appears to provide better protection.

  7. A method for estimating (41)Ar, (85)(,88)Kr and (131m,133)Xe doses to non-human biota.

    PubMed

    Vives I Batlle, J; Jones, S R; Copplestone, D

    2015-06-01

    A method is presented for estimating (41)Ar, (85,88)Kr and (131m,133)Xe dose rates to terrestrial wildlife without having to resort to comparisons with analogue radionuclides. The approach can be used to calculate the dose rates arising from external exposures to given ambient air concentrations of these isotopes. Dose conversion coefficient (DCC) values for a range of representative organisms are calculated, using a Monte Carlo approach to generate absorbed fractions based on representing animals as reference ellipsoid geometries. Plume immersion is the main component of the total DCC. DCC values calculated for a human-sized organism are compared with human dose conversion factors from ICRP Publication 119, demonstrating the consistency of the biota approach with that for humans. An example of application is provided for hypothetical nuclear power plant atmospheric discharges with associated exposures to birds and insects. In this example, the dose rates appear to be dominated by (133)Xe and (88)Kr, respectively. The biota considered would be protected from the effects of noble gas radiation from a population protection perspective.

  8. A method for estimating (41)Ar, (85)(,88)Kr and (131m,133)Xe doses to non-human biota.

    PubMed

    Vives I Batlle, J; Jones, S R; Copplestone, D

    2015-06-01

    A method is presented for estimating (41)Ar, (85,88)Kr and (131m,133)Xe dose rates to terrestrial wildlife without having to resort to comparisons with analogue radionuclides. The approach can be used to calculate the dose rates arising from external exposures to given ambient air concentrations of these isotopes. Dose conversion coefficient (DCC) values for a range of representative organisms are calculated, using a Monte Carlo approach to generate absorbed fractions based on representing animals as reference ellipsoid geometries. Plume immersion is the main component of the total DCC. DCC values calculated for a human-sized organism are compared with human dose conversion factors from ICRP Publication 119, demonstrating the consistency of the biota approach with that for humans. An example of application is provided for hypothetical nuclear power plant atmospheric discharges with associated exposures to birds and insects. In this example, the dose rates appear to be dominated by (133)Xe and (88)Kr, respectively. The biota considered would be protected from the effects of noble gas radiation from a population protection perspective. PMID:25863225

  9. Reproducibility of the /sup 133/Xe inhalation technique in resting studies: task order and sex related effects in healthy young adults

    SciTech Connect

    Warach, S.; Gur, R.C.; Gur, R.E.; Skolnick, B.E.; Obrist, W.D.; Reivich, M.

    1987-12-01

    Repeated applications of the /sup 133/Xe inhalation technique for measuring regional CBF (rCBF) were made during consecutive resting conditions in a sample of young healthy subjects. Subjects were grouped by order and by sex (nine had resting studies as the initial two measurements in a series of four measurement (six men, three women) and six had these measurements later (two men, four women)). Three flow parameters were examined: f1 (fast flow) and IS (initial slope) for gray matter CBF, and CBF-15 for mean CBF (gray and white matter over 15-min integration), as well as w1, the percentage of tissue with fast clearing characteristics. With all groups combined, there were no significant differences between the two resting measurements, and high test-retest correlations were obtained for the flow parameters and w1. Analyses by order and sex grouping revealed, for the flow parameters, significant interactions of test-retest difference with order. Repeated initial studies showed reduced CBF from the first to second measurement, whereas resting studies performed later in the series showed no reduction. Interactions for test-retest difference with sex indicated that reduced CBF in serial measures was more pronounced for women. No hemispheric or regional specificity to account for these effects was found. Correction for PaCO/sub 2/ differences did not alter these results. The results resemble data regarding habituation effects measured for other psychophysiologic measures, and suggest that reduction in CBF for consecutive measurements made on the same day may reflect habituation. This underscores the importance of controlling for effects of habituation on serial measurements of CBF and metabolism.

  10. Computation and Analysis of the Global Distribution of the Radioxenon Isotope 133Xe based on Emissions from Nuclear Power Plants and Radioisotope Production Facilities and its Relevance for the Verification of the Nuclear-Test-Ban Treaty

    NASA Astrophysics Data System (ADS)

    Wotawa, Gerhard; Becker, Andreas; Kalinowski, Martin; Saey, Paul; Tuma, Matthias; Zähringer, Matthias

    2010-05-01

    Monitoring of radioactive noble gases, in particular xenon isotopes, is a crucial element of the verification of the Comprehensive Nuclear-Test-Ban Treaty (CTBT). The capability of the noble gas network, which is currently under construction, to detect signals from a nuclear explosion critically depends on the background created by other sources. Therefore, the global distribution of these isotopes based on emissions and transport patterns needs to be understood. A significant xenon background exists in the reactor regions of North America, Europe and Asia. An emission inventory of the four relevant xenon isotopes has recently been created, which specifies source terms for each power plant. As the major emitters of xenon isotopes worldwide, a few medical radioisotope production facilities have been recently identified, in particular the facilities in Chalk River (Canada), Fleurus (Belgium), Pelindaba (South Africa) and Petten (Netherlands). Emissions from these sites are expected to exceed those of the other sources by orders of magnitude. In this study, emphasis is put on 133Xe, which is the most prevalent xenon isotope. First, based on the emissions known, the resulting 133Xe concentration levels at all noble gas stations of the final CTBT verification network were calculated and found to be consistent with observations. Second, it turned out that emissions from the radioisotope facilities can explain a number of observed peaks, meaning that atmospheric transport modelling is an important tool for the categorization of measurements. Third, it became evident that Nuclear Power Plant emissions are more difficult to treat in the models, since their temporal variation is high and not generally reported. Fourth, there are indications that the assumed annual emissions may be underestimated by factors of two to ten, while the general emission patterns seem to be well understood. Finally, it became evident that 133Xe sources mainly influence the sensitivity of the

  11. An evaluation of the external radiation exposure dosimetry and calculation of maximum permissible concentration values for airborne materials containing 18F, 15O, 13N, 11C and 133Xe.

    PubMed

    Piltingsrud, H V; Gels, G L

    1985-11-01

    To better understand the dose equivalent (D.E.) rates produced by airborne releases of gaseous positron-emitting radionuclides under various conditions of cloud size, a study of the external radiation exposure dosimetry of these radionuclides, as well as negatron, gamma and x-ray emitting 133Xe, was undertaken. This included a calculation of the contributions to D.E. as a function of cloud radii, at tissue depths of 0.07 mm (skin), 3 mm (lens of eye) and 10 mm (whole body) from both the particulate and photon radiations emitted by these radionuclides. Estimates of maximum permissible concentration (MPC) values were also calculated based on the calculated D.E. rates and current regulations for personnel radiation protection (CFR84). Three continuous air monitors, designed for use with 133Xe, were evaluated for applications in monitoring air concentrations of the selected positron emitters. The results indicate that for a given radionuclide and for a cloud greater than a certain radius, personnel radiation dosimeters must respond acceptably to only the photon radiations emitted by the radionuclide to provide acceptable personnel dosimetry. For clouds under that radius, personnel radiation dosimeters must also respond acceptably to the positron or negatron radiations to provide acceptable personnel dosimetry. It was found that two out of the three air concentration monitors may be useful for monitoring air concentrations of the selected positron emitters.

  12. SDAT – Analysis of 131mXe with 133Xe Interference

    SciTech Connect

    Biegalski, Steven R.; Foltz Biegalski, Kendra M.; Haas, Derek A.

    2009-12-01

    The Spectral Deconvolution Analysis Tool (SDAT) software was developed at The University of Texas at Austin. SDAT utilizes a standard spectrum technique for the analysis of beta-gamma coincidence spectra. Testing was performed on the software to compare the standard spectrum analysis technique with a region of interest (ROI) analysis technique. Experimentally produced standard spectra and sample data were produced at the Nuclear Engineering Teaching Laboratory (NETL) TRIGA reactor. The results of the testing showed that the standard spectrum technique had lower errors than the ROI analysis technique for samples with low counting statistics. In contrast, the ROI analysis technique outperformed the standard spectrum technique in high counting statistics samples. It was also shown that the standard spectrum technique benefitted from a compression of the number of channels within the spectra.

  13. Effect of hematocrit and systolic blood pressure on cerebral blood flow in newborn infants

    SciTech Connect

    Younkin, D.P.; Reivich, M.; Jaggi, J.L.; Obrist, W.D.; Delivoria-Papadopoulos, M.

    1987-06-01

    The effects of hematocrit and systolic blood pressure on cerebral blood flow were measured in 15 stable, low birth weight babies. CBF was measured with a modification of the xenon-133 (/sup 133/Xe) clearance technique, which uses an intravenous bolus of /sup 133/Xe, an external chest detector to estimate arterial /sup 133/Xe concentration, eight external cranial detectors to measure cephalic /sup 133/Xe clearance curves, and a two-compartmental analysis of the cephalic /sup 133/Xe clearance curves to estimate CBF. There was a significant inverse correlation between hematocrit and CBF, presumably due to alterations in arterial oxygen content and blood viscosity. Newborn CBF varied independently of systolic blood pressure between 60 and 84 mm Hg, suggesting an intact cerebrovascular autoregulatory mechanism. These results indicate that at least two of the factors that affect newborn animal CBF are operational in human newborns and may have important clinical implications.

  14. Source term estimation of radioxenon released from the Fukushima Dai-ichi nuclear reactors using measured air concentrations and atmospheric transport modeling.

    PubMed

    Eslinger, P W; Biegalski, S R; Bowyer, T W; Cooper, M W; Haas, D A; Hayes, J C; Hoffman, I; Korpach, E; Yi, J; Miley, H S; Rishel, J P; Ungar, K; White, B; Woods, V T

    2014-01-01

    Systems designed to monitor airborne radionuclides released from underground nuclear explosions detected radioactive fallout across the northern hemisphere resulting from the Fukushima Dai-ichi Nuclear Power Plant accident in March 2011. Sampling data from multiple International Modeling System locations are combined with atmospheric transport modeling to estimate the magnitude and time sequence of releases of (133)Xe. Modeled dilution factors at five different detection locations were combined with 57 atmospheric concentration measurements of (133)Xe taken from March 18 to March 23 to estimate the source term. This analysis suggests that 92% of the 1.24 × 10(19) Bq of (133)Xe present in the three operating reactors at the time of the earthquake was released to the atmosphere over a 3 d period. An uncertainty analysis bounds the release estimates to 54-129% of available (133)Xe inventory.

  15. Inspiratory flow and intrapulmonary gas distribution

    SciTech Connect

    Rehder, K.; Knopp, T.J.; Brusasco, V.; Didier, E.P.

    1981-01-01

    The effect of flow of inspired gas on intrapulmonary gas distribution was examined by analysis of regional pulmonary /sup 133/Xe clearances and of total pulmonary /sup 133/Xe clearance measured at the mouth after equilibration of the lungs with /sup 133/Xe. Five awake healthy volunteers (24 to 40 yr of age) and another 5 healthy, anesthetized-paralyzed volunteers (26 to 28 yr of age) were studied while they were in the right lateral decubitus position. The awake subjects were studied at 3 inspiratory flows (0.4, 0.7, and 1.0 L/s) and the anesthetized-paralyzed subjects at 4 inspiratory flows (0.2, 0.5, 1.1, and 1.6 L/s). Interregional differences in /sup 133/Xe clearances along the vertical axis were significantly less during anesthesia-paralysis and mechanical ventilation than during spontaneous breathing in the awake state. No differences in the regional or total pulmonary /sup 133/Xe clearances were detected at these different flows in either of the two states, i.e., the difference between the awake and anesthetized-paralyzed states persisted.

  16. Radioxenon standards used in laboratory inter-comparisons.

    PubMed

    Gohla, H; Auer, M; Cassette, Ph; Hague, R K; Lechermann, M; Nadalut, B

    2016-03-01

    Preparation methods for (133)Xe standards of activity concentration and the results of the 2014 (133)Xe laboratory inter-comparison exercise are described. One element of the quality assurance/quality control (QA/QC) program for laboratories of the International Monitoring System (IMS) will be regular inter-comparison exercises. However, until recently, no activity concentration standards for benchmarking were available. Therefore, two (133)Xe activity concentration reference standards were produced independently by Idaho National Laboratory and Seibersdorf Laboratories and used for the 2014 laboratory inter-comparison exercise. The preparation of a complementary (127)Xe activity concentration standard as well as a (127)Xe laboratory inter-comparison exercise suggests (127)Xe as a suitable isotope for QA/QC of remote IMS noble gas stations.

  17. Preliminary application of dynamic pulmonary xenon-133 single-photon emission tomography in the evaluation of patients with pulmonary emphysema for thoracoscopic lung volume reduction surgery.

    PubMed

    Suga, K; Nishigauchi, K; Matsunaga, N; Matsumoto, T; Kume, N; Sugi, K; Esato, K

    1998-04-01

    Dynamic pulmonary xenon-133 single-photon emission tomography (SPET) with three-dimensional (3D) displays was preliminarily applied to select resection targets for thoracoscopic lung volume reduction surgery (LVRS) and to assess regional ventilatory changes following surgery. Dynamic SPET was performed using a triple-detector SPET system in 14 patients with pulmonary emphysema before and after LVRS. After reconstructing colour-illuminated, surface-rendered 3D images of equilibrium (EQ) and 3-min washout (WO3), a single 3D fusion display was created from these two different time-course image sets, in which the 3D WO3 image indicating 133Xe retention was visible through the overlying 3D EQ image delineating lung contours. Volumetric extent of retention on this display was quantified by a 133Xe retention index, defined as the ratio (%) of total pixel numbers of segmented 3-min WO data to those of EQ data. 133Xe SPET and appropriately thresholded 3D displays efficiently localized a total of 36 retention sites; 19 (52.7%) of these sites were not localized by CT because they were within the widely or homogeneously spreading non-bullous emphysematous lung tissues. The 3D displays enhanced the perception of anatomical configurations and the extent of 133Xe retention compared with multislice tomograms. Postoperatively, 3D fusion display visualized the details of regional changes in retention, and changes in the retention index on the 3D display with a standardized threshold correlated well with changes in 133Xe clearance time (T1/2) and %FEV1 (r = 0.881 and 0. 856, respectively; P<0.0001). This preliminary study indicates that 133Xe SPET and appropriately thresholded, topographic 3D displays are of potential use in selecting resection targets for LVRS, and in evaluating the treatment effects on regional ventilation.

  18. Estimation of the radioactive source dispersion from Fukushima nuclear power plant accident.

    PubMed

    Schöppner, Michael; Plastino, Wolfango; Povinec, Pavel; Nikkinen, Mika; Ruggieri, Federico; Bella, Francesco

    2013-11-01

    Following the Fukushima nuclear power plant accident detections of (133)Xe have been made in various locations. Using results of these remote measurements the Fukushima (133)Xe source term has been reconstructed and compared with previously reconstructed (137)Cs and (131)I source terms. The reconstruction is accomplished by applying atmospheric transport modeling and an adapted least square error method. The obtained results are in agreement with previous estimations of the Fukushima radionuclide source, and also serve as a proof of principle for source term reconstruction based on atmospheric transport modeling.

  19. Solubility of krypton, xenon and radon in polycarbonates. Application for measurement of their radioactive isotopes

    NASA Astrophysics Data System (ADS)

    Pressyanov, D.; Mitev, K.; Dimitrova, I.; Georgiev, S.

    2011-02-01

    Bisphenol-A polycarbonates have a high absorption ability for noble gases that can be employed for sampling and measurement of radioactive isotopes of these gases. In this report the solubility of krypton, xenon and radon in the specified polycarbonates is determined by measurement of 85Kr, 133Xe and 222Rn absorbed in polycarbonate specimens. The found solubility is used to develop a general methodology for measurement of radioactive noble gases in air and water. The methodology is tested in pilot measurements of 133Xe in air under real conditions. The results demonstrate sufficient potential for practical applications.

  20. Hemodynamics of erection in man

    SciTech Connect

    Shirai, M.; Ishii, N.

    1981-02-01

    Inquiry was made into the theory that closure of the efferent vein from the corpora cavernosa is essential for erection of the human penis. To determine whether the venous closure is indeed a prerequisite to human penile erection, two tests were carried out in men: (1) direct infusion in 133Xe into corpora cavernosa and (2) performance of carvernosography. In each case, penile erection was induced by providing the subject with sexual stimulation. The behavioral changes were studied through the 133Xe clearance curve and the contrast medium, respectively. When the penis remained flaccid, the 133Xe clearance curve followed a gentle path and the contrast medium could be noted within the penis for a relatively long period. However, on erection with sexual stimulation, the 133Xe clearance curve fell rapidly instead of following the gentle course expected in the case of venous closure. Also, the contrast medium quickly flowed out of the corpora cavernosa. The human penis therefore can well erect without closure of the efferent vein from the corpora cavernosa.

  1. Noninvasive method of estimating human newborn regional cerebral blood flow

    SciTech Connect

    Younkin, D.P.; Reivich, M.; Jaggi, J.; Obrist, W.; Delivoria-Papadopoulos, M.

    1982-12-01

    A noninvasive method of estimating regional cerebral blood flow (rCBF) in premature and full-term babies has been developed. Based on a modification of the /sup 133/Xe inhalation rCBF technique, this method uses eight extracranial NaI scintillation detectors and an i.v. bolus injection of /sup 133/Xe (approximately 0.5 mCi/kg). Arterial xenon concentration was estimated with an external chest detector. Cerebral blood flow was measured in 15 healthy, neurologically normal premature infants. Using Obrist's method of two-compartment analysis, normal values were calculated for flow in both compartments, relative weight and fractional flow in the first compartment (gray matter), initial slope of gray matter blood flow, mean cerebral blood flow, and initial slope index of mean cerebral blood flow. The application of this technique to newborns, its relative advantages, and its potential uses are discussed.

  2. Adrenergic vasoconstriction in peripheral nerves of the rabbit

    SciTech Connect

    Selander, D.; Mansson, L.G.; Karlsson, L.; Svanvik, J.

    1985-01-01

    The blood flow in the sciatic nerve of the rabbit was estimated from the wash out of intraneurally injected /sup 133/Xe. To avoid diffusion of the tracer into the surrounding muscular tissue, the nerve was covered by a gas-tight plastic film. Using this technique, the basal blood flow in the sciatic nerve was estimated to 35 ml X min-1 X 100 g-1. It was found that intraarterial norepinephrine and electrical stimulation of the lumbar sympathetic chain strongly reduced the wash out of /sup 133/Xe, which only can be explained by a pronounced reduction of the blood flow in the nerve itself. The blood flow again increased within 4 min of stopping the infusion of norepinephrine or the sympathetic stimulation. The prolonged effect and higher neurotoxicity of local anesthetics containing adrenaline may be explained by an alpha receptor-mediated vasoconstriction of the microvessels of peripheral nerves.

  3. Cerebral blood flow studied by Xenon-133 inhalation technique in parkinsonism: loss of hyperfrontal pattern

    SciTech Connect

    Bes, A.; Gueell, A.; Fabre, N.; Dupui, P.; Victor, G.; Geraud, G.

    1983-03-01

    Cerebral blood flow (grey matter flow) in parkinsonism requires further investigation. The noninvasive method of /sup 133/Xe inhalation permits study of larger numbers of subjects than previously used invasive techniques such as the intracarotid /sup 133/Xe injection method. Measurements were made in this laboratory in 30 subjects having Parkinson's disease. Mean hemispheric blood flow (F1) values were 70.4 +/- 9.3 ml/100 g/min, compared to 76.3 for a group of age-matched normal subjects, which is a decrease of -7.8%. The most striking difference was the loss of the hyperfrontal distribution in parkinsonism. The prefrontal F1 values were only 1.8% greater than the hemisphere grey matter flow, compared with 8.5% in controls of a similar age group.

  4. Vertebrobasilar insufficiency revealed by xenon-133 inhalation SPECT

    SciTech Connect

    Delecluse, F.; Voordecker, P.; Raftopoulos, C.

    1989-07-01

    A study of cerebral and cerebellar blood flow reactivity to acetazolamide by xenon-133-inhalation single photon emission computed tomography (/sup 133/Xe SPECT) was carried out in a patient with bouts of transient basilar ischemia, whose neurological examination, computed tomographic scan, and auditory evoked potentials were normal. Though the patient was symptom-free at the time of the study, /sup 133/Xe SPECT demonstrated vertebrobasilar insufficiency by showing an impaired vasodilatory response in both the occipital lobes and the right cerebellar hemisphere. Three weeks later, the patient suffered an extensive stroke in these same areas. We therefore suggest that this method could be of great value in the assessment of vertebrobasilar insufficiency.

  5. Understanding radioxenon isotopical ratios originating from radiopharmaceutical facilities

    NASA Astrophysics Data System (ADS)

    Saey, P. R. J.; Ringbom, A.; Bowyer, T. W.; Becker, A.; de Geer, L.-E.; Nikkinen, M.; Payne, R. F.

    2009-04-01

    It was recently shown that radiopharmaceutical facilities (RPF) are major contributors to the general background of 133Xe and other xenon isotopes both in the northern and southern hemisphere. To distinguish a nuclear explosion signal from releases from civil nuclear facilities, not only the activity concentrations but also the ratios of the four different CTBT relevant radioxenon isotopes (131mXe, 133mXe, 133Xe and 135Xe) have to be well understood. First measurements taken recently in and around two of the world's largest RPF's: NTP at Pelindaba, South Africa and IRE at Fleurus, Belgium have been presented. At both sites, also stack samples were taken in close cooperation with the facility operators. The radioxenon in Belgium could be classified in four classes: the normal European background (133Xe activity between 0 - 5 mBq/m3) on one hand and then the samples where all four isotopes were detected with 133mXe/131mXe > 1. In northern South Africa the Pelindaba RPF is in practice the sole source of radioxenon. It generated a background of 133Xe at the measurement site some 230 km to the west of the RPF of 0 - 5 mBq/m3. In the cases where the air from the Pelindaba facility reached the measurement site directly and in a short time period, the 133Xe was higher, also 135Xe was present and in some samples 133mXe as well. The ratios of the activity concentrations of 135Xe/133Xe vs. 133mXe/131mXe (Multiple Isotope Ratio Plot - MIRC) have been analysed. For both facilities, the possible theoretical ratio's for different scenarios were calculated with the information available and compared with the measurements. It was found that there is an excess of 131mXe present in the European samples compared to theoretical calculations. A similar excess has also been seen in samples measured in northern America. In South Africa, neither the environmental samples nor the stack ones contained 131mXe at measurable levels. This can probably be explained by different processes and

  6. Elevated radioxenon detected remotely following the Fukushima nuclear accident.

    PubMed

    Bowyer, T W; Biegalski, S R; Cooper, M; Eslinger, P W; Haas, D; Hayes, J C; Miley, H S; Strom, D J; Woods, V

    2011-07-01

    We report on the first measurements of short-lived gaseous fission products detected outside of Japan following the Fukushima nuclear releases, which occurred after a 9.0 magnitude earthquake and tsunami on March 11, 2011. The measurements were conducted at the Pacific Northwest National Laboratory (PNNL), (46°16'47″N, 119°16'53″W) located more than 7000 km from the emission point in Fukushima Japan (37°25'17″N, 141°1'57″E). First detections of (133)Xe were made starting early March 16, only four days following the earthquake. Maximum concentrations of (133)Xe were in excess of 40 Bq/m(3), which is more than ×40,000 the average concentration of this isotope is this part of the United States.

  7. Factors affecting the adsorption of xenon on activated carbon

    SciTech Connect

    Underhill, D.W.; DiCello, D.C.; Scaglia, L.A.; Watson, J.A.

    1986-08-01

    The presence of water vapor was found to interfere strongly with the dynamic adsorption of /sup 133/Xe on coconut-base activated charcoal. The percent loss in the xenon adsorption coefficient was similar to values reported earlier for the adsorption of krypton on humidified charcoal. Attempts to increase the adsorption of xenon by (a) using a petroleum-based adsorbent with an extremely high surface area and (b) by impregnation of the adsorbent with iodine were not successful.

  8. Spatial anisotropy of xenon-defect configurations in cubic single crytals

    NASA Astrophysics Data System (ADS)

    Claes, J.; Namavar, F.; Rots, M.

    1982-03-01

    Ion-implanted tungsten and copper single crystals are investigated by the perturbed angular correlation technique, using an allowed β- γ cascade in 133Xe decay. The spatial distribution function describing the orientation of the quadrupole hyperfine interaction does not show up the cubic symmetry of the lattice in the case of xenon-induced radiation damage. This conclusion is interpreted in terms of xenon-vacancy loop interaction.

  9. Regional comparison of technetium-99m DTPA aerosol and radioactive gas ventilation (xenon and krypton) studies in patients with suspected pulmonary embolism

    SciTech Connect

    Ramanna, L.; Alderson, P.O.; Waxman, A.D.; Berman, D.S.; Brachman, M.B.; Kroop, S.A.; Goldsmith, M.; Tanasescu, D.E.

    1986-09-01

    The regional distribution of (99mTc)DTPA aerosol was compared with that of /sup 133/Xe (n = 30) and krypton (n = 24) in a group of patients with suspected pulmonary embolism. All patients had an aerosol study using a recently available commercial generator system, a ventilation study with one of the gases, and perfusion imaging. Regional information was assessed visually on xenon, krypton, and aerosol studies independently by considering each lung as three equal-sized zones. In addition, gas ventilation findings peripheral to regions of aerosol turbulence (hot spots) were evaluated. Only 64% of the zones were in complete agreement on xenon and aerosol. Most of the discordance between xenon and aerosol was accounted for by minor degrees of /sup 133/Xe washout retention in zones that appeared normal in the aerosol study. An agreement rate of 85% was noted between 81mKr and aerosol regionally. The regions of discordance between aerosol and gas studies, however, usually were associated with unimpressive perfusion defects that did not change the scintigraphic probability for pulmonary embolism in any patient. Regarding zones of aerosol hyperdeposition, 76% had associated washout abnormalities on xenon; however, there was no correlation between the presence of these abnormalities or perfusion abnormalities. The results confirm the high sensitivity of /sup 133/Xe washout imaging, but suggest that radioaerosol imaging will detect most parenchymal abnormalities associated with perfusion defects of significance.

  10. Improvements of low-level radioxenon detection sensitivity by a state-of-the art coincidence setup.

    PubMed

    Cagniant, A; Le Petit, G; Gross, P; Douysset, G; Richard-Bressand, H; Fontaine, J-P

    2014-05-01

    The ability to quantify isotopic ratios of 135, 133 m, 133 and 131 m radioxenon is essential for the verification of the Comprehensive Nuclear-Test Ban Treaty (CTBT). In order to improve detection limits, CEA has developed a new on-site setup using photon/electron coincidence (Le Petit et al., 2013. J. Radioanal. Nucl. Chem., DOI : 10.1007/s 10697-013-2525-8.). Alternatively, the electron detection cell equipped with large silicon chips (PIPS) can be used with HPGe detector for laboratory analysis purpose. This setup allows the measurement of β/γ coincidences for the detection of (133)Xe and (135)Xe; and K-shell Conversion Electrons (K-CE)/X-ray coincidences for the detection of (131m)Xe, (133m)Xe and (133)Xe as well. Good energy resolution of 11 keV at 130 keV and low energy threshold of 29 keV for the electron detection were obtained. This provides direct discrimination between K-CE from (133)Xe, (133m)Xe and (131m)Xe. Estimation of Minimum Detectable Activity (MDA) for (131m)Xe is in the order of 1mBq over a 4 day measurement. An analysis of an environmental radioxenon sample using this method is shown. PMID:24332879

  11. Cerebral blood flow in sickle cell cerebrovascular disease

    SciTech Connect

    Huttenlocher, P.R.; Moohr, J.W.; Johns, L.; Brown, F.D.

    1984-05-01

    Cerebral blood flow (CBF) has been studied by the xenon-133 (/sup 133/Xe) inhalation method in 16 children with suspected sickle cell cerebrovascular disease. Abnormalities consisting of decreases in total, hemispheral, or regional CBF were found in 17 of 26 studies. Eleven studies performed immediately after stroke, transient ischemic attack, or depression of state of alertness showed abnormalities. In addition to confirming regional cerebrovascular insufficiency in children with stroke due to major cerebral artery occlusion, the method detected diffuse decrease in CBF in children with stupor, coma, and seizures who had normal angiographic findings. In contrast, six of seven studies obtained after exchange transfusion or during maintenance on hypertransfusion therapy showed normal findings. The difference between results in patients with acute neurologic disturbances and those receiving transfusion therapy was statistically significant (P less than .005). The data indicate that the /sup 133/Xe method reliably demonstrates cerebrovascular impairment in sickle cell disease. They also suggest that CBF changes in patients with sickle cell disease can be reversed by exchange transfusion and by hypertransfusion therapy. The /sup 133/Xe CBF method may be useful for following up children with sickle cell disease who are at high risk for recurrent stroke.

  12. Atmospheric removal times of the aerosol-bound radionuclides 137Cs and 131I measured after the Fukushima Dai-ichi nuclear accident - a constraint for air quality and climate models

    NASA Astrophysics Data System (ADS)

    Kristiansen, N. I.; Stohl, A.; Wotawa, G.

    2012-11-01

    Caesium-137 (137Cs) and iodine-131 (131I) are radionuclides of particular concern during nuclear accidents, because they are emitted in large amounts and are of significant health impact. 137Cs and 131I attach to the ambient accumulation-mode (AM) aerosols and share their fate as the aerosols are removed from the atmosphere by scavenging within clouds, precipitation and dry deposition. Here, we estimate their removal times from the atmosphere using a unique high-precision global measurement data set collected over several months after the accident at the Fukushima Dai-ichi nuclear power plant in March 2011. The noble gas xenon-133 (133Xe), also released during the accident, served as a passive tracer of air mass transport for determining the removal times of 137Cs and 131I via the decrease in the measured ratios 137Cs/133Xe and 131I/133Xe over time. After correction for radioactive decay, the 137Cs/133Xe ratios reflect the removal of aerosols by wet and dry deposition, whereas the 131I/133Xe ratios are also influenced by aerosol production from gaseous 131I. We find removal times for 137Cs of 10.0-13.9 days and for 131I of 17.1-24.2 days during April and May 2011. The removal time of 131I is longer due to the aerosol production from gaseous 131I, thus the removal time for 137Cs serves as a better estimate for aerosol lifetime. The removal time of 131I is of interest for semi-volatile species. We discuss possible caveats (e.g. late emissions, resuspension) that can affect the results, and compare the 137Cs removal times with observation-based and modeled aerosol lifetimes. Our 137Cs removal time of 10.0-13.9 days should be representative of a "background" AM aerosol well mixed in the extratropical Northern Hemisphere troposphere. It is expected that the lifetime of this vertically mixed background aerosol is longer than the lifetime of fresh AM aerosols directly emitted from surface sources. However, the substantial difference to the mean lifetimes of AM aerosols

  13. Atmospheric removal times of the aerosol-bound radionuclides 137Cs and 131I during the months after the Fukushima Dai-ichi nuclear power plant accident - a constraint for air quality and climate models

    NASA Astrophysics Data System (ADS)

    Kristiansen, N. I.; Stohl, A.; Wotawa, G.

    2012-05-01

    Caesium-137 (137Cs) and iodine-131 (131I) are radionuclides of particular concern during nuclear accidents, because they are emitted in large amounts and are of significant health impact. 137Cs and 131I attach to the ambient accumulation-mode (AM) aerosols and share their fate as the aerosols are removed from the atmosphere by scavenging within clouds, precipitation and dry deposition. Here, we estimate their removal times from the atmosphere using a unique high-precision global measurement data set collected over several months after the accident at the Fukushima Dai-ichi nuclear power plant in March 2011. The noble gas xenon-133 (133Xe), also released during the accident, served as a passive tracer of air mass transport for determining the removal times of 137Cs and 131I via the decrease in the measured ratios 137Cs/133Xe and 131I/133Xe over time. After correction for radioactive decay, the 137Cs/133Xe ratios reflect the removal of aerosols by wet and dry deposition, whereas the 131I/133Xe ratios are also influenced by aerosol production from gaseous 131I. We find removal times for 137Cs of 10.0-13.9 days and for 131I of 17.1-24.2 days during April and May 2011. We discuss possible caveats (e.g. late emissions, resuspension) that can affect the results, and compare the 137Cs removal times with observation-based and modeled aerosol lifetimes. Our 137Cs removal time of 10.0-13.9 days should be representative of a "background" AM aerosol well mixed in the extratropical Northern Hemisphere troposphere. It is expected that the lifetime of this vertically mixed background aerosol is longer than the lifetime of AM aerosols originating from surface sources. However, the substantial difference to the mean lifetimes of AM aerosols obtained from aerosol models, typically in the range of 3-7 days, warrants further research on the cause of this discrepancy. Too short modeled AM aerosol lifetimes would have serious implications for air quality and climate model predictions.

  14. Radiation exposure to human trachea from Xenon-133 procedures

    SciTech Connect

    Prohovnik, I.; Metz, C.D.; Atkins, H.L. ||

    1995-08-01

    The general dosimetry of {sup 133}Xe for human studies is well documented, but the resultant radiation exposure to tracheal tissue is poorly known. This organ is of central relevance because the tracer is primarily eliminated through exhalation. We report actual {sup 133}Xe concentrations in respiratory air during measurement of regional cerebral blood flow (rCBF), when the tracer is administered both by inhalation and intravenous injection. Data were collected from 102 patients, with equal gender representation and an age range of 18-82 yr. Most of the patients had subarachnoid hemorrhage or Alzheimer`s disease or were normal control subjects. Average administered doses were 18 {plus_minus} 4 mCi by inhalation and 15 {plus_minus} 3 intravenously. We found average respiratory concentrations of about 1.80 mCi/liter during a 1-min inhalation and 0.74 mCi/liter following intravenous injection of standard doses. These activities drop rapidly: average respiratory concentrations during the second minute are 0.70 mCi/liter for inhalation and 0.19 mCi/liter for intravenous injection and reach negligible levels thereafter. We calculate that the tracheal absorbed dose from {sup 133}Xe procedures is approximately 28 mrad following inhalation and about 11 mrad following intravenous injection. These values reflect the full 11-min exposure, but most of the activity is only present initially. These values will agree with previous estimates and indicate an excellent safety margin. 6 refs., 2 figs., 1 tab.

  15. Atmospheric xenon radioactive isotope monitoring.

    PubMed

    Fontaine, J P; Pointurier, F; Blanchard, X; Taffary, T

    2004-01-01

    The Comprehensive Nuclear Test Ban Treaty (CTBT) organisation is implementing a world-wide monitoring network in order to check that the State Signatories comply with the treaty. One of the monitoring facilities consists of an atmospheric noble gas monitoring equipment. According to the requirements annexed in the treaty, the French Atomic Energy Commission (CEA) developed a device, called SPALAX, which automatically extracts xenon from ambient air and makes in situ measurements of the activities of four xenon radioisotopes (131mXe, 133mXe, 133Xe, 135Xe). The originality of this device is noticeable essentially in the gas sample processing method: thanks to the coupling of a gas permeator and of a noble gas specific adsorbent, it can selectively extract and concentrate xenon to more than 3 x 10 E6. This process is carried out continuously without cryogenic cooling, without any regeneration time. The detection of the xenon radioactive isotopes is done automatically by high spectral resolution gamma spectrometry, a robust technology well-suited for on-field instrumentation. In the year 2000, a prototype was involved in an international evaluation exercise directed by the CTBT organisation (CTBTO). This exercise demonstrated that the SPALAX equipment perfectly met the requirements of the CTBTO for such systems. On the basis of the continuous 24-h resolution record of the atmospheric xenon radioactive isotopes concentrations, the SPALAX system also demonstrated that ambient levels of 133Xe can fluctuate quickly from less than the detection limit to over 40 x 10(-3) Bq m(-3). In order to build an industrial version of this equipment, the CEA entered into a partnership with a French engineering company (S.F.I., Marseille, France), which is now able to produce an industrial version of SPALAX, i.e. more compact and more efficient than the prototypes. The 133Xe minimum detectable concentration is 0.15 x 10(-3) Bq m(-3) air per 24 h sampling cycle.

  16. Suppression of VEGF-induced angiogenesis by the protein tyrosine kinase inhibitor, lavendustin A.

    PubMed Central

    Hu, D E; Fan, T P

    1995-01-01

    1. Vascular endothelial growth factor (VEGF) is a heparin-binding angiogenic factor which specifically acts on endothelial cells via distinct membrane-spanning tyrosine kinase receptors. Here we used the rat sponge implant model to test the hypothesis that the angiogenic activity of VEGF can be suppressed by protein tyrosine kinase (PTK) inhibitors. 2. Neovascular responses in subcutaneous sponge implants were determined by measurements of relative sponge blood flow by use of a 133Xe clearance technique, and confirmed by histological studies and morphometric analysis. 3. Daily local administration of 250 ng VEGF165 accelerated the rate of 133Xe clearance from the sponges and induced an intense neovascularisation. This VEGF165-induced angiogenesis was inhibited by daily co-administration of the selective PTK inhibitor, lavendustin A (10 micrograms), but not its negative control, lavendustin B (10 micrograms). Blood flow measurements and morphometric analysis of 8-day-old sponges showed that lavendustin A reduced the 133Xe clearance of VEGF165-treated sponges from 32.9 +/- 1.5% to 20.9 +/- 1.6% and the total fibrovascular growth area from 62.4 +/- 6.1% to 21.6 +/- 6.8% (n = 12, P < 0.05). 4. Co-injection of suramin (3 mg), an inhibitor of heparin-binding growth factors, also suppressed the VEGF165-elicited neovascular response. In contrast, neither lavendustin A nor suramin produced any effect on the basal sponge-induced angiogenesis. 5. When given alone, low doses of VEGF165 (25 ng) or basic fibroblast growth factor (bFGF; 10 ng) did not modify the basal sponge-induced neovascularisation.(ABSTRACT TRUNCATED AT 250 WORDS) Images Figure 2 Figure 2 PMID:7533611

  17. Regional cerebral blood flow for singers and nonsingers while speaking, singing, and humming a rote passage

    SciTech Connect

    Formby, C.; Thomas, R.G.; Halsey, J.H. Jr. )

    1989-05-01

    Two groups of singers (n = 12,13) and a group of nonsingers (n = 12) each produced the national anthem by (1) speaking and (2) singing the words and by (3) humming the melody. Regional cerebral blood flow (rCBF) was measured at rest and during each phonation task from seven areas in each hemisphere by the {sup 133}Xe-inhalation method. Intrahemisphere, interhemisphere, and global rCBF were generally similar across phonation tasks and did not yield appreciable differences among the nonsingers and the singers.

  18. Separation of rare gases and chiral molecules by selective binding in porous organic cages

    SciTech Connect

    Chen, Linjiang; Reiss, Paul S.; Chong, Samantha Y.; Holden, Daniel; Jelfs, Kim E.; Hasell, Tom; Little, Marc A.; Kewley, Adam; Briggs, Michael E.; Stephenson, Andrew; Thomas, K. M.; Armstrong, Jayne A.; Bell, Jon; Busto, Jose; Noel, Raymond; Liu, Jian; Strachan, Denis M.; Thallapally, Praveen K.; Cooper, Andrew I.

    2014-10-31

    Abstract: The rare gases krypton, xenon, and radon pose both an economic opportunity and a potential environmental hazard. Xenon is used in commercial lighting, medical imaging, and anesthesia, and can sell for $5,000 per kilogram. Radon, by contrast, Is naturally radioactive and the second largest cause of lung cancer, and radioactive xenon, 133Xe, was a major pollutant released In the Fukushima Daiichi Nuclear Power Plant disaster. We describe an organic cage molecule that can capture xenon and radon with unprecedented selectivity, suggesting new technologies for environmental monitoring, removal of pollutants, or the recovery of rare, valuable elements from air.

  19. Evaluation of the response to xenon-133 radiations by thermoluminescent dosimeters used during the accident at Three Mile Island.

    PubMed

    Riley, R J; Zanzonico, P B; Masterson, M E; St Germain, J M; Laughlin, J S

    1982-03-01

    An evaluation is presented of the accuracy and sensitivity of three types of TLD's used during the accident at the Three Mile Island Nuclear Station. This evaluation indicated that, due to the method of calibration, all the dosimeters over-responded to 133Xe radiations. The response ranged from slightly above unity to almost two. Exposures of the TLD's were of two types, namely, the characteristic X-rays either were or were not filtered from the beam. The angular sensitivity of the dosimeters is also reported. PMID:7068394

  20. Standalone Calibration Toolset

    NASA Astrophysics Data System (ADS)

    Cooper, M.

    2013-12-01

    Radioxenon measurements require a well calibrated nuclear detector, which typically requires several weeks to perform a complex analysis of the resulting data to determine the detection efficiencies. To reduce the need to have an expert in nuclear physics, PNNL has developed a Standalone Calibration Toolset (SCT), which will aid an analyst in B-y nuclear detector calibration. SCT takes data generated from measurement of isotopically pure calibration samples: Xe-135, Xe-133, Xe-133m and Xe-131m, and generates nuclear detector configuration files. This will result in a simplified calibration and will make verification and corrections to b-g detectors routine.

  1. Standardization of xenon-127 and measurement of photon emission intensities.

    PubMed

    Rodrigues, M; Lépy, M-C; Cassette, P; Mougeot, X; Bé, M M

    2014-05-01

    Xenon-127 was standardized by internal gas counting using three proportional counters in a differential arrangement to eliminate edge effects. The detection efficiency of the proportional counters was calculated by considering the cascade of events following the electron capture and associated gamma transitions. Activity per unit volume was measured with 0.7% relative standard uncertainty. Gamma-ray spectrometry was performed and absolute photon emission intensities were derived. This study shows that (127)Xe could be a surrogate for (133)Xe for the calibration of remote radio-xenon monitoring stations.

  2. Method of locating a leaking fuel element in a fast breeder power reactor

    DOEpatents

    Honekamp, John R.; Fryer, Richard M.

    1978-01-01

    Leaking fuel elements in a fast reactor are identified by measuring the ratio of .sup.134 Xe to .sup.133 Xe in the reactor cover gas following detection of a fuel element leak, this ratio being indicative of the power and burnup of the failed fuel element. This procedure can be used to identify leaking fuel elements in a power breeder reactor while continuing operation of the reactor since the ratio measured is that of the gases stored in the plenum of the failed fuel element. Thus, use of a cleanup system for the cover gas makes it possible to identify sequentially a multiplicity of leaking fuel elements without shutting the reactor down.

  3. Regional cerebral blood flow in essential hypertension: data evaluation by a mapping system

    SciTech Connect

    Rodriguez, G.; Arvigo, F.; Marenco, S.; Nobili, F.; Romano, P.; Sandini, G.; Rosadini, G.

    1987-01-01

    Regional cerebral blood flow was studied by means of the 133Xe inhalation method in 26 untreated and 10 treated patients with essential hypertension. The untreated subjects were divided into newly and previously diagnosed groups to assess the relation between regional cerebral blood flow and the duration of hypertension. The overall flow reduction was more marked in the frontal and temporal regions in the previously diagnosed group, and this was attributed to pathological changes in the district served by the middle cerebral artery. Regional temporal lobe impairment was also noted in the newly diagnosed and treated subjects. A significant correlation was found between regional cerebral blood flow and mean arterial blood pressure.

  4. Source Term Estimation of Radioxenon Released from the Fukushima Dai-ichi Nuclear Reactors Using Measured Air Concentrations and Atmospheric Transport Modeling

    SciTech Connect

    Eslinger, Paul W.; Biegalski, S.; Bowyer, Ted W.; Cooper, Matthew W.; Haas, Derek A.; Hayes, James C.; Hoffman, Ian; Korpach, E.; Yi, Jing; Miley, Harry S.; Rishel, Jeremy P.; Ungar, R. Kurt; White, Brian; Woods, Vincent T.

    2014-01-01

    Systems designed to monitor airborne radionuclides released from underground nuclear explosions detected radioactive fallout from the Fukushima Daiichi nuclear accident in March 2011. Atmospheric transport modeling (ATM) of plumes of noble gases and particulates were performed soon after the accident to determine plausible detection locations of any radioactive releases to the atmosphere. We combine sampling data from multiple International Modeling System (IMS) locations in a new way to estimate the magnitude and time sequence of the releases. Dilution factors from the modeled plume at five different detection locations were combined with 57 atmospheric concentration measurements of 133-Xe taken from March 18 to March 23 to estimate the source term. This approach estimates that 59% of the 1.24×1019 Bq of 133-Xe present in the reactors at the time of the earthquake was released to the atmosphere over a three day period. Source term estimates from combinations of detection sites have lower spread than estimates based on measurements at single detection sites. Sensitivity cases based on data from four or more detection locations bound the source term between 35% and 255% of available xenon inventory.

  5. Cerebral blood flow in the newborn infant: comparison of Doppler ultrasound and /sup 133/xenon clearance

    SciTech Connect

    Greisen, G.; Johansen, K.; Ellison, P.H.; Fredriksen, P.S.; Mali, J.; Friis-Hansen, B.

    1984-03-01

    Two techniques of Doppler ultrasound examination, continuous-wave and range-gated, applied to the anterior cerebral artery and to the internal carotid artery, were compared with /sup 133/xenon clearance after intravenous injection. Thirty-two sets of measurements were obtained in 16 newborn infants. The pulsatility index, the mean flow velocity, and the end-diastolic flow velocity were read from the Doppler recordings. Mean cerebral blood flow was estimated from the /sup 133/Xe clearance curves. The correlation coefficients between the Doppler and the /sup 133/Xe measurements ranged from 0.41 to 0.82. In the subset of 16 first measurements in each infant, there were no statistically significant differences between the correlation coefficients of the various Doppler ultrasound variables, but the correlation coefficients were consistently lower for the pulsatility index than for mean flow velocity or end-diastolic flow velocity, and they were consistently higher for the range-gated than for the continuous-wave Doppler technique.

  6. Cerebral blood flow during paroxysmal EEG activation induced by sleep in patients with complex partial seizures

    SciTech Connect

    Gozukirmizi, E.; Meyer, J.S.; Okabe, T.; Amano, T.; Mortel, K.; Karacan, I.

    1982-01-01

    Cerebral blood flow (CBF) measurements were combined with sleep polysomnography in nine patients with complex partial seizures. Two methods were used: the 133Xe method for measuring regional (rCBF) and the stable xenon CT method for local (LCBF). Compared to nonepileptic subjects, who show diffuse CBF decreases during stages I-II, non-REM sleep onset, patients with complex partial seizures show statistically significant increases in CBF which are maximal in regions where the EEG focus is localized and are predominantly seen in one temporal region but are also propagated to other cerebral areas. Both CBF methods gave comparable results, but greater statistical significance was achieved by stable xenon CT methodology. CBF increases are more diffuse than predicted by EEG paroxysmal activity recorded from scalp electrodes. An advantage of the 133Xe inhalation method was achievement of reliable data despite movement of the head. This was attributed to the use of a helmet which maintained the probes approximated to the scalp. Disadvantages were poor resolution (7 cm3) and two-dimensional information. The advantage of stable xenon CT method is excellent resolution (80 mm3) in three dimensions, but a disadvantage is that movement of the head in patients with seizure disorders may limit satisfactory measurements.

  7. Estimates of radioxenon released from Southern Hemisphere medical isotope production facilities using measured air concentrations and atmospheric transport modeling.

    PubMed

    Eslinger, Paul W; Friese, Judah I; Lowrey, Justin D; McIntyre, Justin I; Miley, Harry S; Schrom, Brian T

    2014-09-01

    The International Monitoring System (IMS) of the Comprehensive-Nuclear-Test-Ban-Treaty monitors the atmosphere for radioactive xenon leaking from underground nuclear explosions. Emissions from medical isotope production represent a challenging background signal when determining whether measured radioxenon in the atmosphere is associated with a nuclear explosion prohibited by the treaty. The Australian Nuclear Science and Technology Organisation (ANSTO) operates a reactor and medical isotope production facility in Lucas Heights, Australia. This study uses two years of release data from the ANSTO medical isotope production facility and (133)Xe data from three IMS sampling locations to estimate the annual releases of (133)Xe from medical isotope production facilities in Argentina, South Africa, and Indonesia. Atmospheric dilution factors derived from a global atmospheric transport model were used in an optimization scheme to estimate annual release values by facility. The annual releases of about 6.8 × 10(14) Bq from the ANSTO medical isotope production facility are in good agreement with the sampled concentrations at these three IMS sampling locations. Annual release estimates for the facility in South Africa vary from 2.2 × 10(16) to 2.4 × 10(16) Bq, estimates for the facility in Indonesia vary from 9.2 × 10(13) to 3.7 × 10(14) Bq and estimates for the facility in Argentina range from 4.5 × 10(12) to 9.5 × 10(12) Bq. PMID:24811887

  8. Adipose tissue and skeletal muscle blood flow during mental stress

    SciTech Connect

    Linde, B.; Hjemdahl, P.; Freyschuss, U.; Juhlin-Dannfelt, A.

    1989-01-01

    Mental stress (a modified Stroop color word conflict test (CWT)) increased adipose tissue blood flow (ATBF; 133Xe clearance) by 70% and reduced adipose tissue vascular resistance (ATR) by 25% in healthy male volunteers. The vasculatures of adipose tissue (abdomen as well as thigh), skeletal muscle of the calf (133Xe clearance), and the entire calf (venous occlusion plethysmography) responded similarly. Arterial epinephrine (Epi) and glycerol levels were approximately doubled by stress. Beta-Blockade by metoprolol (beta 1-selective) or propranolol (nonselective) attenuated CWT-induced tachycardia similarly. Metoprolol attenuated stress-induced vasodilation in the calf and tended to do so in adipose tissue. Propranolol abolished vasodilation in the calf and resulted in vasoconstriction during CWT in adipose tissue. Decreases in ATR, but not in skeletal muscle or calf vascular resistances, were correlated to increases in arterial plasma glycerol (r = -0.42, P less than 0.05), whereas decreases in skeletal muscle and calf vascular resistances, but not in ATR, were correlated to increases in arterial Epi levels (r = -0.69, P less than 0.01; and r = -0.43, P less than 0.05, respectively). The results suggest that mental stress increases nutritive blood flow in adipose tissue and skeletal muscle considerably, both through the elevation of perfusion pressure and via vasodilatation. Withdrawal of vasoconstrictor nerve activity, vascular beta 2-adrenoceptor stimulation by circulating Epi, and metabolic mechanisms (in adipose tissue) may contribute to the vasodilatation.

  9. Cutaneous blood flow in psoriasis

    SciTech Connect

    Klemp, P.; Staberg, B.

    1983-12-01

    The disappearance rate of /sup 133/Xe was studied in 20 patients with psoriasis vulgaris, using an epicutaneous labeling technique in involved skin lesions or normal-appearing skin of the proximal extensor site of the forearm. Control experiments were performed in 10 normal subjects. Calculations of the cutaneous blood flow (CBF) in psoriatic skin lesions were performed using a tissue-to-blood partition coefficient for /sup 133/Xe, lambda c,pso, of 1.2 ml/100 g/min. lambda c,pso was estimated after the relative content of water, lipids, and proteins had been analyzed in psoriatic skin biopsies of 6 patients with untreated psoriasis. The mean relative content of water was markedly reduced to 23.5 +/- 1.5% (SEM), and lipids and proteins were markedly increased to 2.5 +/- 0.7% and 74.0 +/- 2.2, respectively, compared to previously published data for normal skin (water 72.5%, lipids 1%, proteins 26.5%). Mean CBF in untreated psoriatic skin was 63.5 +/- 9.0 ml/100 g/min. This was significantly higher than the mean CBF in 10 normal subjects, 6.3 +/- 0.5 ml/100 g/min (p much less than 0.0001). Mean CBF in normal-appearing skin in patients with psoriasis was 11.0 +/- 1.3 ml/100 g/min. This was significantly higher than CBF in normal subjects (p less than 0.0002).

  10. Estimation of Explosion Energy Yield at Chernobyl NPP Accident

    NASA Astrophysics Data System (ADS)

    Pakhomov, Sergey A.; Dubasov, Yuri V.

    2010-05-01

    The value of the 133Xe/133mXe isometric activity ratio for the stationary regime of reactor work is about 35, and that for an instant fission (explosion) is about 11, which allowed estimation of the nuclear component of the instant (explosion) energy release during the NPP accident. Atmospheric xenon samples were taken at the trajectory of accident product transfers (in the Cherepovetz area); these samples were measured by a gamma spectrometer, and the 133Xe/133mXe ratio was determined as an average value of 22.4. For estimations a mathematic model was elaborated considering both the value of instant released energy and the schedule of reactor power change before the accident, as well as different fractionation conditions on the isobaric chain. Comparison of estimated results with the experimental data showed the value of the instant specific energy release in the Chernobyl NPP accident to be 2·105-2·106 J/Wt or 6·1014-6·1015 J (100-1,000 kt). This result is matched up to a total reactor power of 3,200 MWt. However this estimate is not comparable with the actual explosion scale estimated as 10t TNT. This suggests a local character of the instant nuclear energy release and makes it possible to estimate the mass of fuel involved in this explosion process to be from 0.01 to 0.1% of total quantity.

  11. Xenon-133 determination of muscle blood flow: Use in evaluating cardioactive drugs

    SciTech Connect

    Wexler, J.P.; Davis, L.; Mancini, D.; Chadwick, B.; Le Jemtel, T.

    1985-05-01

    Cardioactive drugs may effect both the central and peripheral circulatory systems. The effects on the central and peripheral circulatory systems of chronic Captorpril therapy in 7 pts with severe congestive heart failure (CHF) were evaluated simultaneously. Skeletal muscle blood flow (SMBF) determined using 133-Xe washout and a Cd/Te detector, oxygen consumption (VO/sub 2/), and radial artery and femoral vein O/sub 2/ concentration difference (A-V) were determined at rest and peak upright bicycle exercise before (BT) and after (AT) 6-12 weeks of Captopril therapy. In CI pts there was a significant increase in VO/sub 2/ and SMBF AT vs BT. In contrast, in CNC pts there was no change in VO/sub 2/ and a significant decrease in SMBF AT vs BT. In pts with severe CHF who are CI, there is an apparent fall in peripheral vascular resistance (PVR). In contrast, in CNC pts there is an increase in PVR. This study demonstrates that SMBF determines using 133-Xe is an important method for determining the effects of cardioactive drugs.

  12. Evaluation of observed and modelled aerosol lifetimes using radioactive tracers of opportunity and an ensemble of 19 global models

    DOE PAGES

    Kristiansen, N. I.; Stohl, A.; Olivie, D. J. L.; Croft, B.; Sovde, O. A.; Klein, H.; Christoudias, T.; Kunkel, D.; Leadbetter, S. J.; Lee, Y. H.; et al

    2016-03-17

    Aerosols have important impacts on air quality and climate, but the processes affecting their removal from the atmosphere are not fully understood and are poorly constrained by observations. This makes modelled aerosol lifetimes uncertain. In this study, we make use of an observational constraint on aerosol lifetimes provided by radionuclide measurements and investigate the causes of differences within a set of global models. During the Fukushima Dai-Ichi nuclear power plant accident of March 2011, the radioactive isotopes cesium-137 (137Cs) and xenon-133 (133Xe) were released in large quantities. Cesium attached to particles in the ambient air, approximately according to their available aerosolmore » surface area. 137Cs size distribution measurements taken close to the power plant suggested that accumulation-mode (AM) sulfate aerosols were the main carriers of cesium. Hence, 137Cs can be used as a proxy tracer for the AM sulfate aerosol's fate in the atmosphere. In contrast, the noble gas 133Xe behaves almost like a passive transport tracer. Global surface measurements of the two radioactive isotopes taken over several months after the release allow the derivation of a lifetime of the carrier aerosol. We compare this to the lifetimes simulated by 19 different atmospheric transport models initialized with identical emissions of 137Cs that were assigned to an aerosol tracer with each model's default properties of AM sulfate, and 133Xe emissions that were assigned to a passive tracer. We investigate to what extent the modelled sulfate tracer can reproduce the measurements, especially with respect to the observed loss of aerosol mass with time. Modelled 137Cs and 133Xe concentrations sampled at the same location and times as station measurements allow a direct comparison between measured and modelled aerosol lifetime. The e-folding lifetime τe, calculated from station measurement data taken between 2 and 9 weeks after the start of the emissions, is 14.3 days (95

  13. Evaluation of observed and modelled aerosol lifetimes using radioactive tracers of opportunity and an ensemble of 19 global models

    NASA Astrophysics Data System (ADS)

    Kristiansen, N. I.; Stohl, A.; Olivié, D. J. L.; Croft, B.; Søvde, O. A.; Klein, H.; Christoudias, T.; Kunkel, D.; Leadbetter, S. J.; Lee, Y. H.; Zhang, K.; Tsigaridis, K.; Bergman, T.; Evangeliou, N.; Wang, H.; Ma, P.-L.; Easter, R. C.; Rasch, P. J.; Liu, X.; Pitari, G.; Di Genova, G.; Zhao, S. Y.; Balkanski, Y.; Bauer, S. E.; Faluvegi, G. S.; Kokkola, H.; Martin, R. V.; Pierce, J. R.; Schulz, M.; Shindell, D.; Tost, H.; Zhang, H.

    2016-03-01

    Aerosols have important impacts on air quality and climate, but the processes affecting their removal from the atmosphere are not fully understood and are poorly constrained by observations. This makes modelled aerosol lifetimes uncertain. In this study, we make use of an observational constraint on aerosol lifetimes provided by radionuclide measurements and investigate the causes of differences within a set of global models. During the Fukushima Dai-Ichi nuclear power plant accident of March 2011, the radioactive isotopes cesium-137 (137Cs) and xenon-133 (133Xe) were released in large quantities. Cesium attached to particles in the ambient air, approximately according to their available aerosol surface area. 137Cs size distribution measurements taken close to the power plant suggested that accumulation-mode (AM) sulfate aerosols were the main carriers of cesium. Hence, 137Cs can be used as a proxy tracer for the AM sulfate aerosol's fate in the atmosphere. In contrast, the noble gas 133Xe behaves almost like a passive transport tracer. Global surface measurements of the two radioactive isotopes taken over several months after the release allow the derivation of a lifetime of the carrier aerosol. We compare this to the lifetimes simulated by 19 different atmospheric transport models initialized with identical emissions of 137Cs that were assigned to an aerosol tracer with each model's default properties of AM sulfate, and 133Xe emissions that were assigned to a passive tracer. We investigate to what extent the modelled sulfate tracer can reproduce the measurements, especially with respect to the observed loss of aerosol mass with time. Modelled 137Cs and 133Xe concentrations sampled at the same location and times as station measurements allow a direct comparison between measured and modelled aerosol lifetime. The e-folding lifetime τe, calculated from station measurement data taken between 2 and 9 weeks after the start of the emissions, is 14.3 days (95

  14. Xenon-133 and caesium-137 releases into the atmosphere from the Fukushima Dai-ichi nuclear power plant: determination of the source term, atmospheric dispersion, and deposition

    NASA Astrophysics Data System (ADS)

    Stohl, A.; Seibert, P.; Wotawa, G.; Arnold, D.; Burkhart, J. F.; Eckhardt, S.; Tapia, C.; Vargas, A.; Yasunari, T. J.

    2012-03-01

    On 11 March 2011, an earthquake occurred about 130 km off the Pacific coast of Japan's main island Honshu, followed by a large tsunami. The resulting loss of electric power at the Fukushima Dai-ichi nuclear power plant developed into a disaster causing massive release of radioactivity into the atmosphere. In this study, we determine the emissions into the atmosphere of two isotopes, the noble gas xenon-133 (133Xe) and the aerosol-bound caesium-137 (137Cs), which have very different release characteristics as well as behavior in the atmosphere. To determine radionuclide emissions as a function of height and time until 20 April, we made a first guess of release rates based on fuel inventories and documented accident events at the site. This first guess was subsequently improved by inverse modeling, which combined it with the results of an atmospheric transport model, FLEXPART, and measurement data from several dozen stations in Japan, North America and other regions. We used both atmospheric activity concentration measurements as well as, for 137Cs, measurements of bulk deposition. Regarding 133Xe, we find a total release of 15.3 (uncertainty range 12.2-18.3) EBq, which is more than twice as high as the total release from Chernobyl and likely the largest radioactive noble gas release in history. The entire noble gas inventory of reactor units 1-3 was set free into the atmosphere between 11 and 15 March 2011. In fact, our release estimate is higher than the entire estimated 133Xe inventory of the Fukushima Dai-ichi nuclear power plant, which we explain with the decay of iodine-133 (half-life of 20.8 h) into 133Xe. There is strong evidence that the 133Xe release started before the first active venting was made, possibly indicating structural damage to reactor components and/or leaks due to overpressure which would have allowed early release of noble gases. For 137Cs, the inversion results give a total emission of 36.6 (20.1-53.1) PBq, or about 43% of the estimated

  15. Subcutaneous blood flow in psoriasis

    SciTech Connect

    Klemp, P.

    1985-03-01

    The simultaneously recorded disappearance rates of /sup 133/xe from subcutaneous adipose tissue in the crus were studied in 10 patients with psoriasis vulgaris using atraumatic labeling of the tissue in lesional skin (LS) areas and symmetrical, nonlesional skin (NLS) areas. Control experiments were performed bilaterally in 10 younger, healthy subjects. The subcutaneous washout rate constant was significantly higher in LS, 0.79 +/- 0.05 min-1 x 10(2) compared to the washout rate constant of NLS, 0.56 +/- 0.07 min-1. 10(2), or the washout rate constant in the normal subjects, 0.46 +/- 0.17 min-1 x 10(2). The mean washout rate constant in NLS was 25% higher than the mean washout rate constant in the normal subjects. The difference was, however, not statistically significant. Differences in the washout rate constants might be due to abnormal subcutaneous tissue-to-blood partition (lambda) in the LS--and therefore not reflecting the real differences in the subcutaneous blood flow (SBF). The lambda for /sup 133/Xe was therefore measured--using a double isotope washout method (/sup 133/Xe and (/sup 131/I)antipyrine)--in symmetrical sites of the lateral crus in LS and NLS of 10 patients with psoriasis vulgaris and in 10 legs of normal subjects. In LS the lambda was 4.52 +/- 1.67 ml/g, which was not statistically different from that of NLS, 5.25 +/- 2.19 ml/g, nor from that of normal subcutaneous tissue, 4.98 +/- 1.04 ml/g. Calculations of the SBF using the obtained lambda values gave a significantly higher SBF in LS, 3.57 +/- 0.23 ml/100 g/min, compared to SBF in the NLS, 2.94 +/- 0.37 ml/100 g/min. There was no statistically significant difference between SBF in NLS and SBF in the normal subjects. The increased SBF in LS of psoriatics might be a secondary phenomenon to an increased heat loss in the lesional skin.

  16. Diet-induced changes in subcutaneous adipose tissue blood flow in man: effect of beta-adrenoceptor inhibition.

    PubMed

    Simonsen, L; Bülow, J; Astrup, A; Madsen, J; Christensen, N J

    1990-06-01

    The effect of a carbohydrate-rich meal on subcutaneous adipose tissue blood flow was studied with and without continuous i.v. infusion of propranolol in healthy volunteers. The subcutaneous adipose tissue blood flow was measured with the 133Xe washout method in three different locations: the forearm, the thigh and the abdomen. The subjects were given a meal consisting of white bread, jam, honey and apple juice (about 2300 kJ). The meal induced a twofold increase in blood flow in the examined tissues. Propranolol abolished the flow increase in the thigh and the abdomen and reduced it in the forearm. This indicates that the mechanism for the flow increase is elicited by a stimulation of vascular beta-adrenoceptors in the subcutaneous adipose tissue, since the beta-adrenoceptor inhibition did not affect the overall metabolic and hormonal responses to the meal.

  17. Atomic test of the Stokes-Einstein law: Diffusion and solubility of Xe

    NASA Astrophysics Data System (ADS)

    Pollack, Gerald L.

    1981-05-01

    The diffusion coefficient D and the Ostwald solubility α have been measured for 133Xe atoms in water-sucrose solutions ranging in viscosity η from 1 to 289 cP, i.e., 0.68% sucrose by weight. In water D(20 °C)=(1.32+/-0.05)×10-5 cm2/sec, in agreement with the Stokes-Einstein (SE) law. Over the entire range studied the observed dependence is D~η-0.63+/-0.02, significantly departing from the SE law. In water α(20 °C)=0.108+/-0.005. For water-sucrose solutions α is approximately proportional to the volume fraction of water in solution.

  18. SAUNA—a system for automatic sampling, processing, and analysis of radioactive xenon

    NASA Astrophysics Data System (ADS)

    Ringbom, A.; Larson, T.; Axelsson, A.; Elmgren, K.; Johansson, C.

    2003-08-01

    A system for automatic sampling, processing, and analysis of atmospheric radioxenon has been developed. From an air sample of about 7 m3 collected during 12 h, 0.5 cm3 of xenon is extracted, and the atmospheric activities from the four xenon isotopes 133Xe, 135Xe, 131mXe, and 133mXe are determined with a beta-gamma coincidence technique. The collection is performed using activated charcoal and molecular sieves at ambient temperature. The sample preparation and quantification are performed using preparative gas chromatography. The system was tested under routine conditions for a 5-month period, with average minimum detectable concentrations below 1 mBq/ m3 for all four isotopes.

  19. Cerebral Blood Flow Estimation Using Classification Techniques On A Sequence Of Low Resolution Tomographic Evolutive Images

    NASA Astrophysics Data System (ADS)

    Chan, Marie; Aguilar-Martin, Joseph; Boulanouar, Kader; Celsis, Pierre; Marc-Vergnes, Jean P.

    1989-05-01

    In order to improve the performance of the instrumental variable method (IVM) in calculating regional cerebral blood flow (rCBF) using Single Photon Emission Computed Tomography (SPELT), and inert diffusible tracer such as 133Xe, we use Learning Algorithms for Multivariate Data Analysis (LAMDA) to classify the voxels of the images of local concentrations in the brain. The LAMDA method correctly distinguished between extra and intra-cerebral voxels. However the topography of the intra-cerebral classes did not match the Regions Of Interest (ROI) defined on an anatomical basis. Provided that all the intra-cerebral classes contaminated by bone and air passage artefact were rejected, the results given by the NM are in good agreement with those derived by the bolus distribution principle. We thus conclude that LAMDA methods can improve the reliability of images of CBF estimates.

  20. Correlation of clinical and angiographic findings in brain ischemia with regional cerebral blood flow measured by the xenon inhalation technique

    SciTech Connect

    Awad, I.; Little, J.R.; Furlan, A.J.; Weinstein, M.

    1982-07-01

    Eighty-eight patients with brain ischemia underwent cerebral angiography and measurement of regional cerebral blood flow (rCBF) after /sup 133/Xe inhalation. A fast compartment flow rate and an initial slope index were computed for each detector and for each hemisphere. The clinical presentation, angiographic findings, and rCBF results were then examined for significant correlations. Patients with hemispheric infarction most frequently showed bilateral diffusely decreased rCBF. In patients with transient ischemic attacks, no specific pattern emerged. Patients with unilateral internal carotid artery occlusion frequently hd bilateral diffusely decreased rCBF. Patients with severe internal carotid artery stenosis were more likely to show decreased rCBF than were patients with mild or moderate stenosis. The initial slope index seemed to be a more sensitive indicator of brain ischemia than the fast compartment flow rate. The possible pathophysiological significance and relationship to patient management of the various rCBF patterns are discussed.

  1. Subcutaneous blood flow in early male pattern baldness

    SciTech Connect

    Klemp, P.; Peters, K.; Hansted, B.

    1989-05-01

    The subcutaneous blood flow (SBF) was measured by the /sup 133/Xe washout method in the scalp of 14 patients with early male pattern baldness. Control experiments were performed in 14 normal haired men matched for age. The SBF in the scalp of the normal individuals was about 10 times higher than previously reported SBF values in other anatomical regions. In patients with early male pattern baldness, SBF was 2.6 times lower than the values found in the normal individuals (13.7 +/- 9.6 vs 35.7 +/- 10.5 ml/100 g/min-1). This difference was statistically significant (p much less than 0.001). A reduced nutritive blood flow to the hair follicles might be a significant event in the pathogenesis of early male pattern baldness.

  2. Regional cerebral blood flow and anxiety: a correlation study in neurologically normal patients

    SciTech Connect

    Rodriguez, G.; Cogorno, P.; Gris, A.; Marenco, S.; Mesiti, C.; Nobili, F.; Rosadini, G.

    1989-06-01

    Regional CBF (rCBF) was evaluated by the /sup 133/Xe inhalation method in 60 neurologically normal patients (30 men and 30 women) and hemispheric and regional values were correlated with anxiety measurements collected by a self-rating questionnaire before and after the examination. Statistically significant negative correlations between rCBF and anxiety measures were found. rCBF reduction for high anxiety levels is in line with results previously reported by others and could be related to lower performance levels for moderately high anxiety scores as those reported in the present population. This could perhaps be explained by rearrangement of flow from cortical zones to deeper areas of the brain, classically known to be implicated in the control of emotions. However, these results should be interpreted cautiously, since they were obtained in patients and not in normal subjects.

  3. Local blood flow, cerebrovascular autoregulation and CO2 responsiveness in the rabbit hypothalamus

    PubMed Central

    Cranston, W. I.; Rosendorff, C.

    1971-01-01

    1. Local blood flow has been measured in the hypothalamus and other areas of the brain in the conscious rabbit, by measuring the rate of clearance of small volumes (2·5-10 μl.) of a saline solution of the inert tracer 133Xe injected locally. 2. Increasing the arterial PCO2 caused a mean rise in the hypothalamic blood flow of 34%. 3. The hypothalamic blood flow remained relatively constant over a mean arterial blood pressure range of 41-140 mm Hg. 4. Hypothalamic blood flow was relatively unaffected by anaesthesia with intravenous pentobarbitone; by contrast, blood flow in the cerebral cortex was greatly reduced. 5. It is concluded that the technique is a valid and useful one, since CO2 responsiveness and autoregulation is maintained. Different areas of grey matter have different flow rates, and vary in their responsiveness to barbiturate anaesthesia. PMID:5090987

  4. Global radioxenon emission inventory based on nuclear power reactor reports.

    PubMed

    Kalinowski, Martin B; Tuma, Matthias P

    2009-01-01

    Atmospheric radioactivity is monitored for the verification of the Comprehensive Nuclear-Test-Ban Treaty, with xenon isotopes 131mXe, 133Xe, 133mXe and 135Xe serving as important indicators of nuclear explosions. The treaty-relevant interpretation of atmospheric concentrations of radioxenon is enhanced by quantifying radioxenon emissions released from civilian facilities. This paper presents the first global radioxenon emission inventory for nuclear power plants, based on North American and European emission reports for the years 1995-2005. Estimations were made for all power plant sites for which emission data were unavailable. According to this inventory, a total of 1.3PBq of radioxenon isotopes are released by nuclear power plants as continuous or pulsed emissions in a generic year.

  5. Cerebral blood flow asymmetries in headache-free migraineurs

    SciTech Connect

    Levine, S.R.; Welch, K.M.; Ewing, J.R.; Joseph, R.; D'Andrea, G.

    1987-11-01

    Regional cerebral blood flow (rCBF) asymmetries were studied in controls and patients with common and classic/complicated migraine using /sup 133/Xe inhalation with 8 homologously situated external collimators over each cerebral hemisphere. Migraine patients as a group more frequently had posterior rCBF asymmetries than controls (p less than 0.03). Although there were no differences in the number of anterior rCBF asymmetries, migraine patients had 2 or more asymmetric probe pairs more often than controls (p less than 0.02). The posterior rCBF asymmetries, consistent with the site of activation of many migraine attacks, may be related to more labile control of the cerebral circulation.

  6. Occult pulmonary embolism: a common occurrence in deep venous thrombosis

    SciTech Connect

    Dorfman, G.S.; Cronan, J.J.; Tupper, T.B.; Messersmith, R.N.; Denny, D.F.; Lee, C.H.

    1987-02-01

    Ventilation-perfusion scans were used in a prospective study to determine the prevalence of occult pulmonary embolus in proven deep venous thrombosis. Fifty-eight patients without symptoms of pulmonary embolism, but with venographically proven deep venous thrombosis, were subjected to chest radiographs, /sup 99m/Tc macroaggregated-albumin perfusion scans, and /sup 133/Xe ventilation scans. Of the 49 patients with deep venous thrombosis proximal to the calf veins, 17 (35%) had high-probability scans. Of all 58 patients, only 12 (21%) had normal scans. When the study population was compared with a group of 430 patients described in reports of pulmonary perfusion in asymptomatic persons, a significantly higher percentage of high-probability scans was found in the study population with deep venous thrombosis. Baseline ventilation-perfusion lung scanning is valuable for patients with proven above-knee deep venous thrombosis.

  7. Potential impact of releases from a new Molybdenum-99 production facility on regional measurements of airborne xenon isotopes

    SciTech Connect

    Bowyer, Ted W.; Eslinger, Paul W.; Cameron, Ian M.; Friese, Judah I.; Hayes, James C.; Metz, Lori A.; Miley, Harry S.

    2014-03-01

    The monitoring of the radioactive xenon isotopes 131mXe, 133Xe, 133mXe, and 135Xe is important for the detection of nuclear explosions. While backgrounds of the xenon isotopes are short-lived, they are constantly replenished from activities dominated by the fission-based production of 99Mo used for medical procedures. One of the most critical locations on earth for the monitoring of nuclear explosions is the Korean peninsula, where the Democratic Republic of North Korea (DPRK) has announced that it had conducted three nuclear tests between 2009 and 2013. This paper explores the backgrounds that would be caused by the medium to large scale production of 99Mo in the region of the Korean peninsula.

  8. Radioxenon detections in the CTBT International Monitoring System likely related to the announced nuclear test in North Korea conducted on February 12, 2013

    SciTech Connect

    Ringbom, Anders; Axelssson, A.; Aldener, M.; Auer, M.; Bowyer, Ted W.; Fritioff, T.; Hoffman, Ian; Khrustalev, Kirill; Nikkinen, Mika; Popov, Vladimir Y.; Popov, Y.; Ungar, R. Kurt; Wotawa, G.

    2014-02-01

    Abstract: Observations of the radioxenon isotopes 133Xe and 131mXe collected at the IMS stations RN38 and RN58 on April 7-8, and April 12-13 2013, respectively, are unique with respect to the measurement history of these stations. Comparison of measured data with calculated isotopic ratios as well as analysis using atmospheric transport modeling indicate that it is likely that the xenon measured was created in the underground nuclear test conducted by North Korea on February 12, 2013, and released 7 weeks later. More than one release is required to explain all observations. The 131mXe source terms for each release were calculated to 7x1011 Bq, corresponding to about 1-10% of the total xenon inventory for a 10-kt explosion, depending on fractionation and release scenario. The observed ratios could not be used to obtain any information regarding the fissile material that was used in the test.

  9. Normal pressure hydrocephalus. Influences on cerebral hemodynamic and cerebrospinal fluid pressure--chemical autoregulation

    SciTech Connect

    Meyer, J.S.; Tachibana, H.; Hardenberg, J.P.; Dowell, R.E. Jr.; Kitagawa, Y.; Mortel, K.F.

    1984-02-01

    Blood flow in the cerebral gray matter was measured in normal pressure hydrocephalus and Alzheimer disease by 133Xe inhalation. Flow values in the frontal and temporal gray matter increased after lowering cerebrospinal fluid (CSF) pressure by lumbar puncture in normal pressure hydrocephalus (p less than 0.05) and also after shunting. One case with cerebral complications did not improve clinically. In Alzheimer disease the reverse (decreases in flow in the gray matter) occurred after removal of CSF. Normal pressure hydrocephalus was associated with impaired cerebral vasomotor responsiveness during 100% oxygen and 5% carbon dioxide inhalation. This complication was restored toward normal after CSF removal and/or shunting. Cerebral blood flow measurements appear to be useful for confirming the diagnosis of normal pressure hydrocephalus and predicting the clinical benefit from shunting.

  10. SPECT study of regional cerebral blood flow in Alzheimer disease

    SciTech Connect

    Bonte, F.J.; Ross, E.D.; Chehabi, H.H.; Devous, M.D. Sr.

    1986-07-01

    A common cause of dementia in late midlife and old age is Alzheimer disease (AD), which affects more than one in 20 individuals over the age of 65. Past studies of regional cerebral blood flow (rCBF) in patients with AD here suggested blood flow abnormalities, but findings have differed. We have studied 37 patients diagnosed as having AD with inhalation and washout of /sup 133/Xe and single-photon emission computed tomography (SPECT), obtaining evidence of abnormal rCBF patterns in 19. Flow reductions were most common in the temporoparietal regions and were occasionally found in the frontal areas. Investigators using positron-emission tomography (PET) have identified similar findings with respect to rCBF and regional oxygen, glucose, and protein metabolism. The SPECT determination of rCBF, which gives information similar to that provided by PET, may assume importance in the diagnosis of AD and in the differential diagnosis of the dementias.

  11. Analysis of 125Xe electron–photon coincidence decay

    DOE PAGES

    Klingberg, Franziska J.; Biegalski, Steven R.; Prinke, Amanda; Haas, Derek A.; Lowrey, Justin D.

    2015-10-26

    In this study, as part of the verification component of the Comprehensive Nuclear-Test-Ban Treaty (CTBT), environmental gas samples originating from nuclear fission are analyzed for the presence of 131mXe, 133mXe, 133Xe, and 135Xe. In this work, the non-traditional radioxenon isotope 125Xe was investigated. The isotope was produced as an isotopically pure sample via neutron activation of 124Xe at the University of Texas at Austin Nuclear Engineering Teaching Lab’s TRIGA MARK II Reactor. The sample was then measured using a HPGe detector as well as an ARSA-style β–γ coincidence detector. Potential sources and sensitivities for production of 125Xe are also consideredmore » for relevance to the CTBT verification mission.« less

  12. An automated ionization chamber for secondary radioactivity standards.

    PubMed

    Fitzgerald, R

    2010-01-01

    I report on the operation and characterization of a new ionization chamber system, "AUTOIC", featuring a commercial digital electrometer and a commercial robotic sample changer. The relative accuracy of the electrometer was improved significantly beyond the manufacturer's specifications through an in-house calibration of the various ranges, applied via software. The measurement precision and repeatability of the system have been determined by measuring multiple samples of the same radionuclide over the span of two or three years. The linearity of the system was examined by following the decay of (99m)Tc, (99)Mo and (133)Xe sources for up to 19 half-lives and determining half-life values. All of these values agree with the accepted literature values, within their combined uncertainties.

  13. Xenon-133 and caesium-137 releases into the atmosphere from the Fukushima Dai-ichi nuclear power plant: determination of the source term, atmospheric dispersion, and deposition

    NASA Astrophysics Data System (ADS)

    Stohl, A.; Seibert, P.; Wotawa, G.; Arnold, D.; Burkhart, J. F.; Eckhardt, S.; Tapia, C.; Vargas, A.; Yasunari, T. J.

    2011-10-01

    On 11 March 2011, an earthquake occurred about 130 km off the Pacific coast of Japan's main island Honshu, followed by a large tsunami. The resulting loss of electric power at the Fukushima Dai-ichi nuclear power plant (FD-NPP) developed into a disaster causing massive release of radioactivity into the atmosphere. In this study, we determine the emissions of two isotopes, the noble gas xenon-133 (133Xe) and the aerosol-bound caesium-137 (137Cs), which have very different release characteristics as well as behavior in the atmosphere. To determine radionuclide emissions as a function of height and time until 20 April, we made a first guess of release rates based on fuel inventories and documented accident events at the site. This first guess was subsequently improved by inverse modeling, which combined the first guess with the results of an atmospheric transport model, FLEXPART, and measurement data from several dozen stations in Japan, North America and other regions. We used both atmospheric activity concentration measurements as well as, for 137Cs, measurements of bulk deposition. Regarding 133Xe, we find a total release of 16.7 (uncertainty range 13.4-20.0) EBq, which is the largest radioactive noble gas release in history not associated with nuclear bomb testing. There is strong evidence that the first strong 133Xe release started very early, possibly immediately after the earthquake and the emergency shutdown on 11 March at 06:00 UTC. The entire noble gas inventory of reactor units 1-3 was set free into the atmosphere between 11 and 15 March 2011. For 137Cs, the inversion results give a total emission of 35.8 (23.3-50.1) PBq, or about 42% of the estimated Chernobyl emission. Our results indicate that 137Cs emissions peaked on 14-15 March but were generally high from 12 until 19 March, when they suddenly dropped by orders of magnitude exactly when spraying of water on the spent-fuel pool of unit 4 started. This indicates that emissions were not only coming from

  14. Xenon-133 and caesium-137 releases into the atmosphere from the Fukushima Dai-ichi nuclear power plant: determination of the source term, atmospheric dispersion, and deposition

    NASA Astrophysics Data System (ADS)

    Stohl, A.; Seibert, P.; Wotawa, G.; Arnold, D.; Burkhart, J. F.; Eckhardt, S.; Tapia, C.; Vargas, A.; Yasunari, T. J.

    2012-04-01

    This presentation will show the results of a paper currently under review in ACPD and some additional new results, including more data and with an independent box modeling approach to support some of the findings of the ACPD paper. On 11 March 2011, an earthquake occurred about 130 km off the Pacific coast of Japan's main island Honshu, followed by a large tsunami. The resulting loss of electric power at the Fukushima Dai-ichi nuclear power plant (FD-NPP) developed into a disaster causing massive release of radioactivity into the atmosphere. In this study, we determine the emissions of two isotopes, the noble gas xenon-133 (133Xe) and the aerosol-bound caesium-137 (137Cs), which have very different release characteristics as well as behavior in the atmosphere. To determine radionuclide emissions as a function of height and time until 20 April, we made a first guess of release rates based on fuel inventories and documented accident events at the site. This first guess was subsequently improved by inverse modeling, which combined the first guess with the results of an atmospheric transport model, FLEXPART, and measurement data from several dozen stations in Japan, North America and other regions. We used both atmospheric activity concentration measurements as well as, for 137Cs, measurements of bulk deposition. Regarding 133Xe, we find a total release of 16.7 (uncertainty range 13.4-20.0) EBq, which is the largest radioactive noble gas release in history not associated with nuclear bomb testing. There is strong evidence that the first strong 133Xe release started early, before active venting was performed. The entire noble gas inventory of reactor units 1-3 was set free into the atmosphere between 11 and 15 March 2011. For 137Cs, the inversion results give a total emission of 35.8 (23.3-50.1) PBq, or about 42% of the estimated Chernobyl emission. Our results indicate that 137Cs emissions peaked on 14-15 March but were generally high from 12 until 19 March, when they

  15. INGAS: Iranian Noble Gas Analyzing System for radioxenon measurement

    NASA Astrophysics Data System (ADS)

    Doost-Mohammadi, V.; Afarideh, H.; Etaati, G. R.; Safari, M. J.; Rouhi, H.

    2016-03-01

    In this article, Iranian Noble Gas Analyzing System (INGAS) will be introduced. This system is based on beta-gamma coincidence technique and consists of a well-type NaI(Tl) as gamma or X radiation detector and a cylindrical plastic scintillator to detect beta or conversion electron. Standard NIM modules were utilized to detect coincidence events of detectors. Both the beta and gamma detectors were appropriately calibrated. The efficiency curve of gamma detector for volume geometry was obtained by comparing the results of gamma point sources measurements and simulations of GATE V7.0 Monte Carlo code. The performance of detection system was checked by injection of 222Rn and 131mXe gaseous source in the detection cell. The minimum detectable activity of the system for 133Xe is 1.240±0.024 mBq for 24 h measurement time.

  16. The effects of activation procedures on regional cerebral blood flow in humans

    SciTech Connect

    Rozenfeld, D.; Wolfson, L.I.

    1981-07-01

    Regional cerebral blood flow (r-CBF) can be measured using 133XE and collimated detectors. The radionuclide can be administered either by inhalation or intracarotid injection. Comparison of blood flow determinations at rest and during performance of an activity identifies those brain regions that become active during the performance of the activity. Relatively specific patterns of r-CBF are observed during hand movements, sensory stimulation, eye movements, speech, listening, and reading. Regional CBF changes during reasoning and memorization are less specific and less well characterized. It is clear that brain lesions affect r-CBF responses to various activities, but this effect has not been well correlated with functional deficits or recovery of function. Regional CBF measurement gives information about brain activity and the functional response to experimental manipulation. This approach may well add to our understanding of normal, as well as pathologic, brain functioning.

  17. SPECTRAL ANALYSIS OF RADIOXENON

    SciTech Connect

    Cooper, Matthew W.; Bowyer, Ted W.; Hayes, James C.; Heimbigner, Tom R.; Hubbard, Charles W.; McIntyre, Justin I.; Schrom, Brian T.

    2008-09-23

    Monitoring changes in atmospheric radioxenon concentrations is a major tool in the detection of an underground nuclear explosion. Ground based systems like the Automated Radioxenon Sampler /Analyzer (ARSA), the Swedish Unattended Noble gas Analyzer (SAUNA) and the Automatic portable radiometer of isotopes Xe (ARIX), can collect and detect several radioxenon isotopes by processing and transferring samples into a high efficiency beta-gamma coincidence detector. The high efficiency beta-gamma coincidence detector makes these systems highly sensitive to the radioxenon isotopes 133Xe, 131mXe, 133mXe and 135Xe. The standard analysis uses regions of interest (ROI) to determine the amount of a particular radioxenon isotope present. The ROI method relies on the peaks of interest falling within energy limits of the ROI. Some potential problems inherent in this method are the reliance on stable detector gains and a fixed resolution for each energy peak. In addition, when a high activity sample is measured there will be more interference among the ROI, in particular within the 133Xe, 133mXe, and 131mXe regions. A solution to some of these problems can be obtained through spectral fitting of the data. Spectral fitting is simply the fitting of the peaks using known functions to determine the number and relative peak positions and widths. By knowing this information it is possible to determine which isotopes are present. Area under each peak can then be used to determine an overall concentration for each isotope. Using the areas of the peaks several key detector characteristics can be determined: efficiency, energy calibration, energy resolution and ratios between interfering isotopes (Radon daughters).

  18. High frequency jet ventilation and intermittent positive pressure ventilation. Effect of cerebral blood flow in patients after open heart surgery

    SciTech Connect

    Pittet, J.F.; Forster, A.; Suter, P.M. )

    1990-02-01

    Attenuation of ventilator-synchronous pressure fluctuations of intracranial pressure has been demonstrated during high frequency ventilation in animal and human studies, but the consequences of this effect on cerebral blood flow have not been investigated in man. We compared the effects of high frequency jet ventilation and intermittent positive pressure ventilation on CBF in 24 patients investigated three hours after completion of open-heart surgery. The patients were investigated during three consecutive periods with standard sedation (morphine, pancuronium): a. IPPV; b. HFJV; c. IPPV. Partial pressure of arterial CO{sub 2} (PaCO{sub 2}: 4.5-5.5 kPa) and rectal temperature (35.5 to 37.5{degree}C) were maintained constant during the study. The CBF was measured by intravenous {sup 133}Xe washout technique. The following variables were derived from the cerebral clearance of {sup 133}Xe: the rapid compartment flow, the initial slope index, ie, a combination of the rapid and the slow compartment flows, and the ratio of fast compartment flow over total CBF (FF). Compared to IPPV, HFJV applied to result in the same mean airway pressure did not produce any change in pulmonary gas exchange, mean systemic arterial pressure, and cardiac index. Similarly, CBF was not significantly altered by HFJV. However, important variations of CBF values were observed in three patients, although the classic main determinants of CBF (PaCO{sub 2}, cerebral perfusion pressure, Paw, temperature) remained unchanged. Our results suggest that in patients with normal systemic hemodynamics, the effects of HFJV and IPPV on CBF are comparable at identical levels of mean airway pressure.

  19. Divergent effects of flavone acetic acid on established versus developing tumour blood flow.

    PubMed Central

    Mahadevan, V.; Hart, I. R.

    1991-01-01

    Flavone Acetic Acid (FAA) exerts much of its effect by reducing tumour blood flow. Previous studies on FAA-induced changes in blood flow have used established tumours with a functional microvasculature. Using radioactive Xenon(133Xe) clearance to monitor local blood flow we show that the effects of FAA are dependent on the presence of this functional microvasculature with no evidence that FAA inhibits the actual development of tumour microcirculation. Thus, administration of multiple doses of FAA around the time of tumour cell injection failed to diminish t1/2 values of 133Xe (e.g. t1/2 16 min for FAA vs 14 min for saline controls at 10 days) or to affect tumour volumes (5.55 +/- 0.06 cm3 in FAA-treated animals vs 5.7 +/- 1.3 cm3 in controls at 25 days). In marked contrast a single dose of FAA (200 mg kg-1 body weight) 2 weeks after tumour cell injection dramatically extended t1/2 times (47 min for FAA vs 7 min for controls; P less than 0.001) and significantly reduced tumour burden. This effect is specific for tumour microvasculature and is not directed simply at new vessels since a similar treatment of animals with implanted-sponge-induced granulation tissue had no effect on t1/2 times (6.8 +/- 1.1 min for FAA at 200 mg kg-1 vs 7.2 +/- 1.0 min for saline-treated controls. PMID:1712621

  20. Local variation in cutaneous and subcutaneous blood flow measured by CdTe(C1) minidetectors in normal and psoriatic skin

    SciTech Connect

    Klemp, P.; Bojsen, J.

    1986-02-01

    The accuracy of the /sup 133/Xe washout method and the validity of newly developed cadmium telluride CdTe(Cl) minisemiconductor detectors were estimated by performing comparative, simultaneous measurements of both cutaneous (CBF) and subcutaneous (SBF) blood flow using 2 conventional scintillation sodium iodide NaI(Tl) and CdTe(Cl) detectors over the same radioactive depot in each of 10 individuals. The accuracy of the /sup 133/Xe washout method was found to be 13-15% (C.V.) for the CBF measurements and 9-12% (C.V.) for the SBF measurements. The CdTe(Cl) detectors, which have a weight of 20 g and were attached directly over the radioactive depot, may replace stationary NaI(Tl) detectors placed 20 cm from the depot for measurements of both CBF and SBF. Two CdTe(Cl) detectors were used for estimations of the local variation in CBF and SBF within a distance of 5 cm in normal skin of 10 individuals. The C.V. was 7% for the CBF measurements and 18% for the SBF measurements. Measurements of CBF and SBF were performed in 6 psoriatic patients who developed typical Woronoff rings. The local CBF differed significantly from the center of psoriatic plaques to the margin, in the Woronoff ring, and in nonlesional skin. In contrast, SBF was remarkably equal within the plaque and in the Woronoff ring. Cutaneous blood flow in chronic stable, lesional psoriatic skin was significantly lower than previously published values for active lesional psoriatic skin, but significantly higher than CBF in normal individuals. Measurements of CBF in tetrahydrofurfuryl nicotinic acid (Trafuril)-treated skin showed higher values than measurements of CBF in the postischemic hyperemia period both in normal and in lesional psoriatic skin. Trafuril induced a significant increase of CBF in both lesional and nonlesional skin.

  1. Environmental characterisation of a major radioxenon source in Europe

    NASA Astrophysics Data System (ADS)

    Saey, P. R. J.; Ringbom, A.; Becker, A.; Camps, J.; Paquet, N.; Sonck, M.; Taffary, T.; van der Meer, K.; Verboomen, B.; Zähringer, M.

    2009-04-01

    In the framework of the verification of the Comprehensive Nuclear-Test-Ban Treaty (CTBT) the atmospheric background of environmental radioxenon has been studied. It was recently shown that radiopharmaceutical facilities (RPF) have a major contribution to the general background of 133Xe and other xenon isotopes both in the northern and southern hemisphere. The daily International Monitoring System (IMS) noble gas measurements around the globe are influenced from such anthropogenic sources that could hide relevant radioxenon signals. To distinguish a nuclear explosion from releases from civil nuclear facilities, not only the activity concentration but also the ratio of different radioxenon isotopes (131mXe, 133mXe, 133Xe and 135Xe) plays a crucial role, since the ratios can be used to discriminate source types. Theoretical release and ratio studies were recently published, but no high-sensitive measurements in and close to radiopharmaceutical facilities have ever been performed. During the summer of 2008, a three week field campaign was carried out in the region around the Belgian radiopharmaceutical facility IRE in Fleurus, the world third largest one. The scope was to obtain the activity concentration of the releases and the isotopic composition. Two 6-hour noble gas measurements, using mobile SAUNA sampling equipment were collected each day at different distances from the facility (1 - 100 km). The sampling locations were guided by atmospheric dispersion model results. Three samples from the stack itself were also collected. All 38 samples were shipped after collection to and measured with a SAUNA at the laboratory in Stockholm, Sweden. The environmental concentrations of 133Xe were measured and found to be in the range between 0.7 - 4 105 mBq/m3. Nine samples contained all four CTBT relevant radioxenon isotopes. The concentrations of the stack spike samples were in the range 2 109 - 4 1010 mBq/m3. This corresponds to a daily release of around 1 TBq. This is

  2. Evaluation of environmental radioxenon isotopical signals from a singular large source emitter

    NASA Astrophysics Data System (ADS)

    Saey, P. R. J.; Bowyer, T. W.; Aldener, M.; Becker, A.; Cooper, M. W.; Elmgren, K.; Faanhof, A.; Hayes, J. C.; Hosticka, B.; Lidey, L. S.

    2009-04-01

    In the framework of the verification of the Comprehensive Nuclear-Test-Ban Treaty (CTBT) the atmospheric background of environmental radioxenon is been studied near areas that could be affected by man-made sources. It was recently shown that radiopharmaceutical facilities (RPF) make a major contribution to the general background of 133Xe and other xenon isotopes both in the northern and southern hemisphere. The daily IMS noble gas measurements around the globe are influenced from such anthropogenic sources that could mask radioxenon signals from a nuclear explosion. To distinguish a nuclear explosion signal from releases from civil nuclear facilities, not only the activity concentration but also the ratio of different radioxenon isotopes (131mXe, 133mXe, 133Xe and 135Xe) plays a crucial role, since the ratios can be used to discriminate source types. Theoretical release and ratio studies were recently published, but no measurements close to radiopharmaceutical facilities have ever been performed. The world's fourth largest radiopharmaceutical facility, NTP Radioisotopes Ltd, is located in Pelindaba, South Africa. Other than a small nuclear power plant, located 1300 km southwest, near Cape Town and a small research reactor in the DR of Congo, located 2700 km northwest, this is the only facility that is known to emit any radioxenon on the African continent south of the Equator. This source is likely very dominant with respect to xenon emission. This makes it a point source, which is a unique situation, as all other worldwide large radiopharmaceutical facilities are situated in regions surrounded by many other nuclear facilities. Between 10 November and 22 December 2008, radioxenon was measured continuously with a radioactive xenon measurement system, at the North-West University, Mafikeng, South Africa, which is situated 250 km northwest of Pelindaba. Fifty-six 12-hour samples were measured with a beta-gamma coincidence detector, of which 55 contained 133Xe with

  3. Improved β-γ Coincidence Detector For Radioxenon Detection

    SciTech Connect

    Cooper, Matthew W; Carman, April J; Hayes, James C; Heimbigner, Tom R; Hubbard, Charles W; Litke, Kevin E; McIntyre, Justin I; Morris, Scott J; Ripplinger, Michael D; Suarez, Reynold

    2005-08-31

    The Automated Radio-xenon Analyzer/Sampler (ARSA), built by Pacific Northwest National Laboratory (PNNL), can collect and detect several radioxenon isotopes. ARSA is very sensitive to 133Xe, 131mXe, 133mXe and 135Xe due to the compact high efficiency coincidence detector it uses. For this reason it is an excellent treaty monitoring and environmental sampling device. Although the system is shown to be both robust and reliable, based on several field tests, it is also complex due to a detailed photomultiplier tube gain matching regime. This complexity is a problem from a maintenance and quality assurance/quality control (QA/QC) standpoint. To reduce these issues a simplified coincident detector has been developed. A comparison of three different well detectors has been completed. In addition, a new plastic scintillator gas cell was constructed. The new simplified detector system has been demonstrated to equal or better performance compared with the original ARSA design in spectral resolution and efficiency and significantly easier to setup and calibrate.

  4. Ultrasound modulated light blood flow measurement using intensity autocorrelation function: a Monte-Carlo simulation

    NASA Astrophysics Data System (ADS)

    Tsalach, A.; Metzger, Y.; Breskin, I.; Zeitak, R.; Shechter, R.

    2014-03-01

    Development of techniques for continuous measurement of regional blood flow, and in particular cerebral blood flow (CBF), is essential for monitoring critical care patients. Recently, a novel technique, based on ultrasound modulation of light was developed for non-invasive, continuous CBF monitoring (termed ultrasound-tagged light (UTL or UT-NIRS)), and shown to correlate with readings of 133 Xe SPECT1 and laser Doppler2. Coherent light is introduced into the tissue concurrently with an Ultrasound (US) field. Displacement of scattering centers within the sampled volume induced by Brownian motion, blood flow and the US field affects the photons' temporal correlation. Hence, the temporal fluctuations of the obtained speckle pattern provide dynamic information about the blood flow. We developed a comprehensive simulation, combining the effects of Brownian motion, US and flow on the obtained speckle pattern. Photons trajectories within the tissue are generated using a Monte-Carlo based model. Then, the temporal changes in the optical path due to displacement of scattering centers are determined, and the corresponding interference pattern over time is derived. Finally, the light intensity autocorrelation function of a single speckle is calculated, from which the tissue decorrelation time is determined. The simulation's results are compared with in-vitro experiments, using a digital correlator, demonstrating decorrelation time prediction within the 95% confidence interval. This model may assist in the development of optical based methods for blood flow measurements and particularly, in methods using the acousto-optic effect.

  5. The Solubility of Xenon in Simple Organic Solvents and in Aqueous Amino Acid Solutions.

    NASA Astrophysics Data System (ADS)

    Himm, Jeffrey Frank

    We have measured the Ostwald solubility (L) of ('133)Xe in a variety of liquids, including normal alkanes, normal alkanols, and aqueous solutions of amino acids, NaCl, and sucrose. For the alkanes and alkanols, measurements were made in the temperature range from 10-50(DEGREES)C. Values of L were found to decrease with increasing temperature, and also with increasing chain length, for both series of solvents. Thermodynamic properties of solution (enthalpy and entropy of solution) are calculated using both mole fraction and number density scales. Results are interpreted using Uhlig's model of the solvation process. Measurements of L in aqueous amino acid solutions were made at 25(DEGREES)C. Concentrations of amino acids in solution varied from near saturation for each of the amino acids studied to pure water. In all solutions, except those with NaCl, L decreases linearly with increasing solution molarity. Hydration numbers (H), the mean number of water molecules associated with each solute molecule, were determined for each amino acid, for NaCl, and for sucrose. Values of H obtained ranged from near zero (arginine, H = 0.2 (+OR-) 0.5) to about 16 (NaCl, H = 16.25 (+OR-) 0.3).

  6. Middle cerebral artery blood velocity and cerebral blood flow and O2 uptake during dynamic exercise.

    PubMed

    Madsen, P L; Sperling, B K; Warming, T; Schmidt, J F; Secher, N H; Wildschiødtz, G; Holm, S; Lassen, N A

    1993-01-01

    Results obtained by the 133Xe clearance method with external detectors and by transcranial Doppler sonography (TCD) suggest that dynamic exercise causes an increase of global average cerebral blood flow (CBF). These data are contradicted by earlier data obtained during less-well-defined conditions. To investigate this controversy, we applied the Kety-Schmidt technique to measure the global average levels of CBF and cerebral metabolic rate of oxygen (CMRO2) during rest and dynamic exercise. Simultaneously with the determination of CBF and CMRO2, we used TCD to determine mean maximal flow velocity in the middle cerebral artery (MCA Vmean). For values of CBF and MCA Vmean a correction for an observed small drop in arterial PCO2 was carried out. Baseline values for global CBF and CMRO2 were 50.7 and 3.63 ml.100 g-1.min-1, respectively. The same values were found during dynamic exercise, whereas a 22% (P < 0.0001) increase in MCA Vmean was observed. Hence, the exercise-induced increase in MCA Vmean is not a reflection of a proportional increase in CBF.

  7. Induced hypertension for the treatment of cerebral ischemia after subarachnoid hemorrhage. Direct effect on cerebral blood flow

    SciTech Connect

    Muizelaar, J.P.; Becker, D.P.

    1986-04-01

    The best treatment for symptomatic cerebral ischemia from presumed vasospasm after aneurysmal subarachnoid hemorrhage remains a matter of controversy. A direct effect of any treatment modality on regional cerebral blood flow has never been documented. In a series of 43 patients operated on for ruptured anterior circulation aneurysms, five patients (11.6%) developed clinical signs of cerebral ischemia postoperatively. In four of those patients, the diagnosis of vasospasm was made with measurements of cerebral blood flow (133Xe inhalation or intravenous injection, 10-16 detectors, cerebral blood flow infinity). Treatment with induced arterial hypertension with phenylephrine was instituted. Hemodilution was instituted in one patient; the other three patients already had hematocrits in the range of 33. Within 1 hour, the cerebral blood flow measurement was repeated to document the effect of treatment. The average pretreatment hemispherical blood flow on the operated side was 18.8 mL/100 g per minute, on the contralateral side 21.0 mL/100 g per minute. With treatment these flows increased to 30.8 and 35.8 mL/100 g per minute, respectively. There was also an immediate and obvious positive clinical effect in all patients. The role of measurement of cerebral blood flow in the clinical management of vasospasm is discussed. We stress the theoretical and practical advances of measurements of cerebral blood flow over cerebral angiography, especially in comatose patients.

  8. Closing capacity in awake and anesthetized-paralyzed man.

    PubMed

    Juno, J; Marsh, H M; Knopp, T J; Rehder, K

    1978-02-01

    Functional residual capacity (FRC), closing capacity (CC), and (FRC--CC) were determined in 61 supine patients using the 133Xe bolus test. In 28 of the 61 patients measurements were made both while the patients were awake and during anesthesia-paralysis. Both FRC and CC decreased significantly after induction of anesthesia-paralysis. The magnitude of the reduction in CC, but not of FRC, was dependent on the relationship between FRC and CC in the awake state. Patients whose FRC was larger than their CC while awake (group I) showed less decrease in CC than FRC, i.e., (FRC--CC) decreased. By contrast, those patients whose CC was larger than their FRC while awake (group II) showed a greater decrease in CC than in FRC, i.e., (FRC--CC) became less negative. The reduction in CC after induction of anesthesia-paralysis may result from an increased elastic recoil of the lung. The larger reduction in CC in group II patients may have been due to a larger increase in elastic recoil, possibly due to the development of atelactasis.

  9. Thenar muscle blood flow and bone mineral in the forearms of lumberjacks.

    PubMed

    Karjalainen, P; Alhava, E M; Valtola, J

    1975-02-01

    Forty lumberjacks who had used a chain saw for 0-20 years and who had no general disease affecting the bones were studied by measuring the thenar muscle blood flow of both hands by the 133-Xe local clearance method. Bone mineral in the left forearm in the region of cancellous and cortical bone was assessed by the 241-Am gamma ray attenuation method. Virbration was found to decrease the blood flow in the saw-bearing left hand compared with the right hand of the lumberjacks. The bone mineral density (g/vm-3) was lower in the forearm bones of the lumberjacks than in controls of the same age with healthy bones. Moreover the poorer the thenar muscle blood flow, the greater was the decrease in the mineral density of the distal radius. Measurement of the mineral density of the forearm bones by the gramma ray attenuation method can be used for early detection of bone lesions in traumatic vasospastic disease.

  10. Machine learning for radioxenon event classification for the Comprehensive Nuclear-Test-Ban Treaty.

    PubMed

    Stocki, Trevor J; Li, Guichong; Japkowicz, Nathalie; Ungar, R Kurt

    2010-01-01

    A method of weapon detection for the Comprehensive nuclear-Test-Ban-Treaty (CTBT) consists of monitoring the amount of radioxenon in the atmosphere by measuring and sampling the activity concentration of (131m)Xe, (133)Xe, (133m)Xe, and (135)Xe by radionuclide monitoring. Several explosion samples were simulated based on real data since the measured data of this type is quite rare. These data sets consisted of different circumstances of a nuclear explosion, and are used as training data sets to establish an effective classification model employing state-of-the-art technologies in machine learning. A study was conducted involving classic induction algorithms in machine learning including Naïve Bayes, Neural Networks, Decision Trees, k-Nearest Neighbors, and Support Vector Machines, that revealed that they can successfully be used in this practical application. In particular, our studies show that many induction algorithms in machine learning outperform a simple linear discriminator when a signal is found in a high radioxenon background environment. PMID:19811861

  11. Maximum reasonable radioxenon releases from medical isotope production facilities and their effect on monitoring nuclear explosions.

    PubMed

    Bowyer, Theodore W; Kephart, Rosara; Eslinger, Paul W; Friese, Judah I; Miley, Harry S; Saey, Paul R J

    2013-01-01

    Fission gases such as (133)Xe are used extensively for monitoring the world for signs of nuclear testing in systems such as the International Monitoring System (IMS). These gases are also produced by nuclear reactors and by fission production of (99)Mo for medical use. Recently, medical isotope production facilities have been identified as the major contributor to the background of radioactive xenon isotopes (radioxenon) in the atmosphere (Stocki et al., 2005; Saey, 2009). These releases pose a potential future problem for monitoring nuclear explosions if not addressed. As a starting point, a maximum acceptable daily xenon emission rate was calculated, that is both scientifically defendable as not adversely affecting the IMS, but also consistent with what is possible to achieve in an operational environment. This study concludes that an emission of 5 × 10(9) Bq/day from a medical isotope production facility would be both an acceptable upper limit from the perspective of minimal impact to monitoring stations, but also appears to be an achievable limit for large isotope producers. PMID:22995862

  12. Patterns of pulmonary perfusion scans in normal subjects. IV. The prevalence of abnormal scans in smokers 30 to 49 years of age

    SciTech Connect

    Fedullo, P.F.; Kapitan, K.S.; Brewer, N.S.; Ashburn, W.L.; Hartman, M.T.; Moser, K.M.

    1989-05-01

    The usefulness of ventilation-perfusion scans in the diagnosis of pulmonary embolism is limited by the wide range of pulmonary diseases that are associated with abnormal scans, and by the largely undetermined prevalence of abnormal scans in persons without cardiopulmonary disease. In prior studies, we found perfusion defects to be rarely present in young persons and in older nonsmokers. To determine if normal older smokers have a higher prevalence of abnormal ventilation and perfusion scans, we performed six-view /sup 99m/Tc perfusion (Q) scans and /sup 133/Xe ventilation (V) scans in 40 subjects 30 to 49 yr of age who had no known cardiopulmonary disease. Each subject had undergone a history, physical examination, electrocardiogram, spirometry, and posteroanterior chest roentgenogram prior to scanning. All V and Q scans were interpreted blindly and independently by two experienced readers. No subject demonstrated a lobar or segmental defect on two views. One subject had a matched subsegmental defect, and one subject had delayed washout from a subsegmental area of the right upper lobe during V scanning, with a normal Q scan. We conclude that abnormal V and Q scans are uncommon among normal smokers 30 to 49 yr of age.

  13. Patterns of pulmonary perfusion scans in normal subjects

    SciTech Connect

    Wallace, J.M.; Moser, K.M.; Hartman, M.T.; Ashburn, W.L.

    1981-01-01

    A vital factor conditioning the usage of the pulmonary perfusion (Q) scan in the evaluation of patients suspected of pulmonary embolism is the prevalence of abnormal Q scans in subjects free of cardiopulmonary disease. Because this prevalence has not been well defined, we performed Q scans in 80 nonsmoking subjects 18 to 29 yr of age having no known active cardiopulmonary disease. Each subject underwent a history, physical examination, electrocardiogram, spirometry, and PA chest roentgenogram, followed by a 6-view Q scan. Two subjects in whom a Q defect was suspected underwent a /sup 133/Xe equilibrium-washout ventilation (V) scan. All Q scans were interpreted blindly and independently by 2 experienced readers. Seventy-nine of the 80 Q scans were read as normal. No subject demonstrated a lobar or segmental defect. One of the 80 subjects, who had a mild pectus excavatum, had a left upper lobe subsegmental defect, which was not seen on the V scan. Based on the statistical analysis of these data, no more than 3.68% of normal nonsmoking persons in this age group may have a lobar or segmental Q scan defect and no more than 6.77% may have a subsegmental defect (with 95% confidence). Therefore, our study indicated that Q scan defects, particularly lobar or segmental, are rarely present among normal nonsmokers in this age group.

  14. The effect of amphetamine on regional cerebral blood flow during cognitive activation in schizophrenia

    SciTech Connect

    Daniel, D.G.; Weinberger, D.R.; Jones, D.W.; Zigun, J.R.; Coppola, R.; Handel, S.; Bigelow, L.B.; Goldberg, T.E.; Berman, K.F.; Kleinman, J.E. )

    1991-07-01

    To explore the role of monoamines on cerebral function during specific prefrontal cognitive activation, we conducted a double-blind placebo-controlled crossover study of the effects of 0.25 mg/kg oral dextroamphetamine on regional cerebral blood flow (rCBF) as determined by 133Xe dynamic single-photon emission-computed tomography (SPECT) during performance of the Wisconsin Card Sorting Test (WCST) and a sensorimotor control task. Ten patients with chronic schizophrenia who had been stabilized for at least 6 weeks on 0.4 mg/kg haloperidol participated. Amphetamine produced a modest, nonsignificant, task-independent, global reduction in rCBF. However, the effect of amphetamine on task-dependent activation of rCBF (i.e., WCST minus control task) was striking. Whereas on placebo no significant activation of rCBF was seen during the WCST compared with the control task, on amphetamine significant activation of the left dorsolateral prefrontal cortex (DLPFC) occurred (p = 0.0006). Both the mean number of correct responses and the mean conceptual level increased (p less than 0.05) with amphetamine relative to placebo. In addition, with amphetamine, but not with placebo, a significant correlation (p = -0.71; p less than 0.05) emerged between activation of DLPFC rCBF and performance of the WCST task. These findings are consistent with animal models in which mesocortical catecholaminergic activity modulates and enhances the signal-to-noise ratio of evoked cortical activity.

  15. Tissue/blood partition coefficients for xenon in various adipose tissue depots in man.

    PubMed

    Bülow, J; Jelnes, R; Astrup, A; Madsen, J; Vilmann, P

    1987-02-01

    Tissue/blood partition coefficients (lambda) for xenon were calculated for subcutaneous adipose tissue from the abdominal wall and the thigh, and for the perirenal adipose tissue after chemical analysis of the tissues for lipid, water and protein content. The lambda in the perirenal tissue was found to correlate linearly to the relative body weight (RBW) in per cent with the regression equation lambda = 0.045 . RBW + 0.99. The subcutaneous lambda on the abdomen correlated linearly to the local skinfold thickness (SFT) with the equation lambda = 0.22 SFT + 2.99. Similarly lambda on the thigh correlated to SFT with the equation lambda = 0.20 . SFT + 4.63. It is concluded that the previously accepted lambda value of 10 is generally too high in perirenal as well as in subcutaneous tissue. Thus, by application of the present regression equations, it is possible to obtain more exact estimates of the adipose tissue blood flow measured with the 133Xe wash-out method.

  16. Radioxenon spiked air

    DOE PAGES

    Watrous, Matthew G.; Delmore, James E.; Hague, Robert K.; Houghton, Tracy P.; Jenson, Douglas D.; Mann, Nick R.

    2015-08-27

    Four of the radioactive xenon isotopes (131mXe, 133mXe, 133Xe and 135Xe) with half-lives ranging from 9 h to 12 days are produced from nuclear fission and can be detected from days to weeks following their production and release. Being inert gases, they are readily transported through the atmosphere. Sources for release of radioactive xenon isotopes include operating nuclear reactors via leaks in fuel rods, medical isotope production facilities, and nuclear weapons' detonations. They are not normally released from fuel reprocessing due to the short half-lives. The Comprehensive Nuclear-Test-Ban Treaty has led to creation of the International Monitoring System. The Internationalmore » Monitoring System, when fully implemented, will consist of one component with 40 stations monitoring radioactive xenon around the globe. Monitoring these radioactive xenon isotopes is important to the Comprehensive Nuclear-Test-Ban Treaty in determining whether a seismically detected event is or is not a nuclear detonation. A variety of radioactive xenon quality control check standards, quantitatively spiked into various gas matrices, could be used to demonstrate that these stations are operating on the same basis in order to bolster defensibility of data across the International Monitoring System. This study focuses on Idaho National Laboratory's capability to produce three of the xenon isotopes in pure form and the use of the four xenon isotopes in various combinations to produce radioactive xenon spiked air samples that could be subsequently distributed to participating facilities.« less

  17. Analysis of data from sensitive U.S. monitoring stations for the Fukushima Dai-ichi nuclear reactor accident.

    PubMed

    Biegalski, S R; Bowyer, T W; Eslinger, P W; Friese, J A; Greenwood, L R; Haas, D A; Hayes, J C; Hoffman, I; Keillor, M; Miley, H S; Moring, M

    2012-12-01

    The March 11, 2011 9.0 magnitude undersea megathrust earthquake off the coast of Japan and subsequent tsunami waves triggered a major nuclear event at the Fukushima Dai-ichi nuclear power station. At the time of the event, units 1, 2, and 3 were operating and units 4, 5, and 6 were in a shutdown condition for maintenance. Loss of cooling capacity to the plants along with structural damage caused by the earthquake and tsunami resulted in a breach of the nuclear fuel integrity and release of radioactive fission products to the environment. Fission products started to arrive in the United States via atmospheric transport on March 15, 2011 and peaked by March 23, 2011. Atmospheric activity concentrations of (131)I reached levels of 3.0×10(-2) Bqm(-3) in Melbourne, FL. The noble gas (133)Xe reached atmospheric activity concentrations in Ashland, KS of 17 Bqm(-3). While these levels are not health concerns, they were well above the detection capability of the radionuclide monitoring systems within the International Monitoring System of the Comprehensive Nuclear-Test-Ban Treaty.

  18. Diaphragmatic contraction and the gradient of alveolar expansion in the lateral posture.

    PubMed

    Roussos, C S; Martin, R R; Engel, L A

    1977-07-01

    Using 133Xe we measured the vertical distribution of regional volume in four subjects in the lateral decubitus posture at 20, 40, 60, and 80% of vital capacity (VC). To study the influence of diaphragmatic tone, all measurements were performed either when transdiaphragmatic pressure (Pdi) was low, i.e., diaphragm was "relaxed" (RD) or during voluntary diaphragmatic contraction (VDC). The latter was achieved by tensing the abdominal muscles while keeping the glottis open. Under both conditions the gradient of alveolar expansion tended to be curvilinear, with a discontinuity at the level of the mediastinum. At all lung volumes the difference in regional volume between dependent and nondependent lung regions was less during VDC than during RD. At 70% total lung capacity (TLC) this difference, expressed as percent of regional TLC (%TLCr), decreased from 19.7 +/- 1.7 (mean +/- 1 SE) %TLCr during RD to 3.9 +/- 1.5% TLCr during VDC. It is likely that diaphragmatic tension influences the pleural pressure gradient and regional volume distribution 1) by modifying the transmission of the abdominal hydrostatic pressure gradient to the thorax, and 2) by an upward displacement of the mediastinum.

  19. Regulation of pulpal blood flow

    SciTech Connect

    Kim, S.

    1985-04-01

    The regulation of blood flow of the dental pulp was investigated in dogs and rats anesthetized with sodium pentobarbital. Pulpal blood flow was altered by variations of local and systemic hemodynamics. Macrocirculatory blood flow (ml/min/100 g) in the dental pulp was measured with both the /sup 133/Xe washout and the 15-microns radioisotope-labeled microsphere injection methods on the canine teeth of dogs, to provide a comparison of the two methods in the same tooth. Microcirculatory studies were conducted in the rat incisor tooth with microscopic determination of the vascular pattern, RBC velocity, and intravascular volumetric flow distribution. Pulpal resistance vessels have alpha- and beta-adrenergic receptors. Activation of alpha-receptors by intra-arterial injection of norepinephrine (NE) caused both a reduction in macrocirculatory Qp in dogs and decreases in arteriolar and venular diameters and intravascular volumetric flow (Qi) in rats. These responses were blocked by the alpha-antagonist PBZ. Activation of beta-receptors by intra-arterial injection of isoproterenal (ISO) caused a paradoxical reduction of Qp in dogs. In rats, ISO caused a transient increase in arteriolar Qi followed by a flow reduction; arteriolar dilation was accompanied by venular constriction. These macrocirculatory and microcirculatory responses to ISO were blocked by the alpha-antagonist propranolol.

  20. Isotopic signature of atmospheric xenon released from light water reactors.

    PubMed

    Kalinowski, Martin B; Pistner, Christoph

    2006-01-01

    A global monitoring system for atmospheric xenon radioactivity is being established as part of the International Monitoring System to verify compliance with the Comprehensive Nuclear-Test-Ban Treaty (CTBT). The isotopic activity ratios of (135)Xe, (133m)Xe, (133)Xe and (131m)Xe are of interest for distinguishing nuclear explosion sources from civilian releases. Simulations of light water reactor (LWR) fuel burn-up through three operational reactor power cycles are conducted to explore the possible xenon isotopic signature of nuclear reactor releases under different operational conditions. It is studied how ratio changes are related to various parameters including the neutron flux, uranium enrichment and fuel burn-up. Further, the impact of diffusion and mixing on the isotopic activity ratio variability are explored. The simulations are validated with reported reactor emissions. In addition, activity ratios are calculated for xenon isotopes released from nuclear explosions and these are compared to the reactor ratios in order to determine whether the discrimination of explosion releases from reactor effluents is possible based on isotopic activity ratios.

  1. Sufentanil does not increase cerebral blood flow in healthy human volunteers

    SciTech Connect

    Mayer, N.; Weinstabl, C.; Podreka, I.; Spiss, C.K. )

    1990-08-01

    The effect of sufentanil on human cerebral blood flow (CBF) was studied in seven unpremedicated, healthy volunteers 31 +/- 3.5 yr of age (mean +/- SD) and either sex. CBF (ml.100 g-1.min-1) was measured noninvasively with the 133Xe clearance technique and a scintillation camera before and after sufentanil 0.5 micrograms/kg administered intravenously. This technique provides values for global blood flow and for gray and white matter blood flow, and from 13 preselected regions in one hemisphere. After the administration of sufentanil, the volunteers were stimulated verbally in order to prevent their loss of consciousness and hypercarbia. Heart rate (HR), arterial pressure, oxyhemoglobin saturation, and end-tidal CO2 ETCO2 were recorded during the measurements. Neither global CBF (46.1 +/- 1.6 control and 43 +/- 1.9 after sufentanil, mean +/- SEM) nor gray (76.5 +/- 3.2 and 70.9 +/- 6.1) or white (22.7 +/- 1.5 and 24.2 +/- 1.6) matter blood flow changed significantly after sufentanil administration. As well, no significant differences in HR (72 +/- 4 control and 79 +/- 4 beats per min after sufentanil) and ETCO2 (39.8 +/- 1.4 and 41.1 +/- 1.1 mmHg) were observed. It is concluded that sufentanil has no significant effect on CBF in healthy human volunteers.

  2. Measuring radioactive noble gases by absorption in polycarbonates and other organics: From radon indoors to nuclear safety

    NASA Astrophysics Data System (ADS)

    Pressyanov, Dobromir S.

    2013-07-01

    The report summarizes recent research and practice of using materials with high absorption ability to noble gases to measure their radioactive isotopes. Most of the studies employ bisphenol-A based polycarbonates, because of their remarkably high absorption ability to noble gases. This is the material of which commercial CDs/DVDs are made and they may serve as serendipitous, already available in dwellings, radon and thoron detectors. We present the essence of the gathered experimental evidence that the CD/DVD method can successfully address some long-lasted problems in radon dosimetry: The first is making sufficiently precise retrospective 222Rn dosimetry for the purposes of epidemiological studies and risk estimation. The second is rapid identification of buildings with radon problem. We demonstrate how this can be used to develop an integrated approach to the radon problem. Within this approach detection, diagnostic and mitigation are considered as an unified whole, and the interval between the decision to provide disks for analysis and the complete mitigation of the building, if radon problem is identified, is short. Besides radon and thoron, bisphenol-A based polycarbonates were successfully used to measure 85Kr and 133Xe for the purposes of the effluents control and nuclear safety of nuclear installations. The perspectives to employ other organic materials in which noble gases are highly soluble for measurement of their radioactive isotopes are also discussed.

  3. Tracheal dead space influences regional ventilation measurement in dogs

    SciTech Connect

    Delaunois, L.; Boileau, R.; Martin, R.R. )

    1990-02-01

    The lung volume at which airway closure begins during expiration (closing volume, CV) can be measured (1) with a radioactive bolus inspired at residual volume (RV) and (2) with the single-breath N2 elimination test. In previous studies in dogs, we observed that N2 CV was systematically larger than 133Xe bolus CV (Xe CV) (N2 CV %vital capacity (VC) = 35 +/- 2.3 (SE) vs. Xe CV %VC = 24 +/- 2.2, P less than 0.01). Because the regional RV in the dog is evenly distributed throughout the lung and all airways closed at RV, N2 CV is related to the regional distribution of the tracheal N2; differences between N2 and Xe CV could then be related to the size of the inhaled dead space. Simultaneous measurements of Xe and N2 CV were performed at various sites of Xe bolus injection while the regional distribution of the bolus was measured. Injections at the level of the carina increased Xe CV to a value (30 +/- 1.4%VC) near simultaneous N2 CV (32 +/- 1.5%VC) and increased the unevenness of regional distribution of the Xe bolus. The difference between N2 and Xe CV is then the result of the size of the inspired tracheal dead space. Moreover, comparisons between different values of Xe CV require injections of the boluses at the same distance from the carina.

  4. CTBTO Contractor Laboratory Test Sample Production Report

    SciTech Connect

    Bob Hague; Tracy Houghton; Nick Mann; Matt Watrous

    2013-08-01

    In October 2012 scientists from both Idaho National Laboratory (INL) and the CTBTO contact laboratory at Seibersdorf, Austria designed a system and capability test to determine if the INL could produce and deliver a short lived radio xenon standard in time for the standard to be measured at the CTBTO contact laboratory at Seibersdorf, Austria. The test included sample standard transportation duration and potential country entrance delays at customs. On October 23, 2012 scientists at the Idaho National Laboratory (INL) prepared and shipped a Seibersdorf contract laboratory supplied cylinder. The canister contained 1.0 scc of gas that consisted of 70% xenon and 30% nitrogen by volume. The t0 was October 24, 2012, 1200 ZULU. The xenon content was 0.70 +/ 0.01 scc at 0 degrees C. The 133mXe content was 4200 +/ 155 dpm per scc of stable xenon on t0 (1 sigma uncertainty). The 133Xe content was 19000 +/ 800 dpm per scc of stable xenon on t0 (1 sigma uncertainty).

  5. Radioxenon spiked air.

    PubMed

    Watrous, Matthew G; Delmore, James E; Hague, Robert K; Houghton, Tracy P; Jenson, Douglas D; Mann, Nick R

    2015-12-01

    Four of the radioactive xenon isotopes ((131m)Xe, (133m)Xe, (133)Xe and (135)Xe) with half-lives ranging from 9 h to 12 days are produced from nuclear fission and can be detected from days to weeks following their production and release. Being inert gases, they are readily transported through the atmosphere. Sources for release of radioactive xenon isotopes include operating nuclear reactors via leaks in fuel rods, medical isotope production facilities, and nuclear weapons' detonations. They are not normally released from fuel reprocessing due to the short half-lives. The Comprehensive Nuclear-Test-Ban Treaty has led to creation of the International Monitoring System. The International Monitoring System, when fully implemented, will consist of one component with 40 stations monitoring radioactive xenon around the globe. Monitoring these radioactive xenon isotopes is important to the Comprehensive Nuclear-Test-Ban Treaty in determining whether a seismically detected event is or is not a nuclear detonation. A variety of radioactive xenon quality control check standards, quantitatively spiked into various gas matrices, could be used to demonstrate that these stations are operating on the same basis in order to bolster defensibility of data across the International Monitoring System. This paper focuses on Idaho National Laboratory's capability to produce three of the xenon isotopes in pure form and the use of the four xenon isotopes in various combinations to produce radioactive xenon spiked air samples that could be subsequently distributed to participating facilities. PMID:26318775

  6. Effects of nimodipine on cerebral blood flow and cerebrospinal fluid pressure after cardiac arrest: correlation with neurologic outcome.

    PubMed

    Forsman, M; Aarseth, H P; Nordby, H K; Skulberg, A; Steen, P A

    1989-04-01

    Fifty-one patients were included in a blind randomized study to evaluate whether the Ca-blocker nimodipine could influence cerebral blood flow (CBF) or cerebrospinal fluid pressure (CSFP) during the cerebral hypoperfusion period that follows resuscitation from cardiac arrest and to determine whether changes in CBF correlate with neurologic outcome. CBF measured 1 to 4 hours after arrest with the use of 133Xe intravenous was significantly greater with nimodipine than with placebo (27 +/- 3 versus 13 +/- 1 ml.100 g-1.min-1 at 3 hours), but with no significant difference at 24 hours. There was no clinical evidence of seriously increased CSFP in any patient in either group the first 48 hours. Mean arterial pressure was significantly lower (86 +/- 4 versus 101 +/- 4 mm Hg at 3 hours), and antiarrhythmic drugs were used significantly less frequently in the nimodipine group than in the placebo group. Twelve patients in each group eventually regained consciousness. There was no significant difference in neurologic status between the two groups at any point, and no positive correlation between CBF in the hypoperfusion period and neurologic outcome. PMID:2929976

  7. Muscle and whole body metabolism after norepinephrine.

    PubMed

    Kurpad, A V; Khan, K; Calder, A G; Elia, M

    1994-06-01

    The effect of an infusion of norepinephrine (0.42 nmol.kg-1.min-1) on energy metabolism in the whole body (using indirect calorimetry and the arteriovenous forearm catheterization techniques in eight healthy young male adults. The activity of the triglyceride-fatty acid cycle, which mainly operates in nonmuscular tissues, was also assessed by measuring glycerol turnover using [2H5]glycerol (to indicate lipolysis) and indirect calorimetry (to indicate net fat oxidation). Norepinephrine increased whole body oxygen consumption by almost 10% (P < 0.01), but the estimated oxygen consumption of muscles tended to decrease. Muscle blood flow (measured by 133Xe) and forearm blood flow (measured by strain-gauge plethysmography) were not significantly affected by norepinephrine, but the rate of uptake of nonesterified fatty acids and beta-hydroxybutyrate increased severalfold (P < 0.05), whereas that of glucose did not. The activity of the triglyceride-fatty acid cycle increased fourfold after norepinephrine administration, having a marginal effect on resting energy expenditure (approximately 1.5%) but accounting for approximately 15% of the increase in whole body energy expenditure. This study provides no evidence that skeletal muscle is an important site for norepinephrine-induced thermogenesis and suggests that an increase in the activity of the triglyceride-fatty acid cycle contributes to the norepinephrine-induced increase in energy expenditure of nonmuscular tissues.

  8. Ventilation-perfusion imaging in evaluating regional lung function in nonpenetrating injury to the chest.

    PubMed

    Van Eeden, S F; Klopper, J F; Alheit, B; Bardin, P G

    1989-03-01

    The extent of chest wall and lung injury after nonpenetrating injury to the chest (NIC) determine how aggressive and invasive management modalities should be. We investigated the value of ventilation (133Xe) and perfusion (99mTc) studies as indicators of extent of lung injury in 28 patients with moderate to severe unilateral NIC. The ventilation-perfusion (V/Q) abnormalities were compared with parameters conventionally used to evaluate NIC. All studies were carried out within 24 h of NIC and repeated 24 h later. Ventilation (p less than 0.001) and perfusion (p less than 0.01) abnormalities were more extensive soon after NIC than suggested by chest roentgenograms. Chest x-ray film changes lagged behind V/Q changes on admission and also after 24 h. The extent of ventilation, perfusion, and chest x-ray film abnormalities on admission were all predictors of increased morbidity. V/Q studies may be useful to define the extent as well as the changes in regional lung function following NIC.

  9. Modeling of long range transport pathways for radionuclides to Korea during the Fukushima Dai-ichi nuclear accident and their association with meteorological circulations.

    PubMed

    Lee, Kwan-Hee; Kim, Ki-Hyun; Lee, Jin-Hong; Yun, Ju-Yong; Kim, Cheol-Hee

    2015-10-01

    The Lagrangian FLEXible PARTicle (FLEXPART) dispersion model and National Centers for Environmental Prediction/Global Forecast System (NCEP/GFS) meteorological data were used to simulate the long range transport pathways of three artificial radionuclides: (131)I, (137)Cs, and (133)Xe, coming into Korean Peninsula during the Fukushima Dai-ichi nuclear accident. Using emission rates of these radionuclides estimated from previous studies, three distinctive transport routes of these radionuclides toward the Korean Peninsula for a period from 10 March to 20 April 2011 were exploited by three spatial scales: 1) intercontinental scale - plume released since mid-March 2011 and transported to the North to arrive Korea on 23 March 2011, 2) global (hemispherical) scale - plume traveling over the whole northern hemisphere passing through the Pacific Ocean/Europe to reach the Korean Peninsula with relatively low concentrations in late March 2011 and, 3) regional scale - plume released on early April 2011 arrived at the Korean Peninsula via southwest sea of Japan influenced directly by veering mesoscale wind circulations. Our identification of these transport routes at three different scales of meteorological circulations suggests the feasibility of a multi-scale approach for more accurate prediction of radionuclide transport in the study area. In light of the fact that the observed arrival/duration time of peaks were explained well by the FLEXPART model coupled with NCEP/GFS input data, our approach can be used meaningfully as a decision support model for radiation emergency situations. PMID:26149179

  10. Radioxenon detections in the CTBT international monitoring system likely related to the announced nuclear test in North Korea on February 12, 2013.

    PubMed

    Ringbom, A; Axelsson, A; Aldener, M; Auer, M; Bowyer, T W; Fritioff, T; Hoffman, I; Khrustalev, K; Nikkinen, M; Popov, V; Popov, Y; Ungar, K; Wotawa, G

    2014-02-01

    Observations made in April 2013 of the radioxenon isotopes (133)Xe and (131m)Xe at measurement stations in Japan and Russia, belonging to the International Monitoring System for verification of the Comprehensive Nuclear-Test-Ban Treaty, are unique with respect to the measurement history of these stations. Comparison of measured data with calculated isotopic ratios as well as analysis using atmospheric transport modeling indicate that it is likely that the xenon measured was created in the underground nuclear test conducted by North Korea on February 12, 2013, and released 7-8 weeks later. More than one release is required to explain all observations. The (131m)Xe source terms for each release were calculated to 0.7 TBq, corresponding to about 1-10% of the total xenon inventory for a 10 kt explosion, depending on fractionation and release scenario. The observed ratios could not be used to obtain any information regarding the fissile material that was used in the test.

  11. Modeling of long range transport pathways for radionuclides to Korea during the Fukushima Dai-ichi nuclear accident and their association with meteorological circulations.

    PubMed

    Lee, Kwan-Hee; Kim, Ki-Hyun; Lee, Jin-Hong; Yun, Ju-Yong; Kim, Cheol-Hee

    2015-10-01

    The Lagrangian FLEXible PARTicle (FLEXPART) dispersion model and National Centers for Environmental Prediction/Global Forecast System (NCEP/GFS) meteorological data were used to simulate the long range transport pathways of three artificial radionuclides: (131)I, (137)Cs, and (133)Xe, coming into Korean Peninsula during the Fukushima Dai-ichi nuclear accident. Using emission rates of these radionuclides estimated from previous studies, three distinctive transport routes of these radionuclides toward the Korean Peninsula for a period from 10 March to 20 April 2011 were exploited by three spatial scales: 1) intercontinental scale - plume released since mid-March 2011 and transported to the North to arrive Korea on 23 March 2011, 2) global (hemispherical) scale - plume traveling over the whole northern hemisphere passing through the Pacific Ocean/Europe to reach the Korean Peninsula with relatively low concentrations in late March 2011 and, 3) regional scale - plume released on early April 2011 arrived at the Korean Peninsula via southwest sea of Japan influenced directly by veering mesoscale wind circulations. Our identification of these transport routes at three different scales of meteorological circulations suggests the feasibility of a multi-scale approach for more accurate prediction of radionuclide transport in the study area. In light of the fact that the observed arrival/duration time of peaks were explained well by the FLEXPART model coupled with NCEP/GFS input data, our approach can be used meaningfully as a decision support model for radiation emergency situations.

  12. Analysis of data from sensitive U.S. monitoring stations for the Fukushima Dai-ichi nuclear reactor accident

    SciTech Connect

    Biegalski, Steven R.; Bowyer, Ted W.; Eslinger, Paul W.; Friese, Judah I.; Greenwood, Lawrence R.; Haas, Derek A.; Hayes, James C.; Hoffman, Ian; Keillor, Martin E.; Miley, Harry S.; Morin, Marc P.

    2012-12-01

    The March 11, 2011 9.0 magnitude undersea megathrust earthquake off the coast of Japan and subsequent tsunami waves triggered a major nuclear event at the Fukushima Dai-ichi nuclear power station. At the time of the event, units 1, 2, and 3 were operating and units 4, 5, and 6 were in a shutdown condition for maintenance. Loss of cooling capacity to the plants along with structural damage caused by the earthquake and tsunami resulted in a breach of the nuclear fuel integrity and release of radioactive fission products to the environment. Fission products started to arrive in the United States via atmospheric transport on March 15, 2011 and peaked by March 23, 2011. Atmospheric activity concentrations of 131I reached levels of 3.0 * 10*2 Bqm*3 in Melbourne, FL. The noble gas 133Xe reached atmospheric activity concentrations in Ashland, KS of 17 Bqm*3. While these levels are not health concerns, they were well above the detection capability of the radionuclide monitoring systems within the International Monitoring System of the Comprehensive Nuclear-Test-Ban Treaty.

  13. Plan for radionuclide tracer studies of the residence time distribution in the Wilsonville dissolver and preheater

    SciTech Connect

    Jolley, R.L.; Begovich, J.M.; Brashear, H.R.; Case, N.; Clark, T.G.; Emery, J.F.; Patton, B.D.; Rodgers, B.R.; Villiers-Fisher, J.F.; Watson, J.S.

    1983-12-01

    Stimulus-response measurements using radiotracers to measure residence time distribution (RTD) and hydrodynamic parameters for the preheaters and dissolvers at the Ft. Lewis Solvent Refined Coal (SRC) and the Exxon Donor Solvent (EDS) coal conversion pilot plants are reviewed. A plan is also presented for a series of radioactive tracer studies proposed for the Advanced Coal Liquefaction Facility at Wilsonville, Alabama, to measure the RTD for the preheater and dissolvers in the SRC-I mode. The tracer for the gas phase will be /sup 133/Xe, and /sup 198/Au (on carbonized resin or as an aqueous colloidal suspension) will be used as the slurry tracer. Four experimental phases are recommended for the RTD tracer studies: (1) preheater; (2) dissolver with 100% takeoff; (3) dissolver with 100% takeoff and solids withdrawal; and (4) dissolver with 50% takeoff. Eighteen gas-tracer and 22 liquid-tracer injections are projected to accomplish the four experimental phases. Two to four tracer injections are projected for preliminary tests to ensure the capability of safe injection of the radiotracers and the collection of statistically significant data. A complete projected cost and time schedule is provided, including procurement of necessary components, preparation of the radiotracers, assembly and testing of tracer injection apparatus and detection systems, onsite work and tracer injections, laboratory experimentation, data analysis, and report writing.

  14. Effects of hypnosis on regional cerebral blood flow during ischemic pain with and without suggested hypnotic analgesia.

    PubMed

    Crawford, H J; Gur, R C; Skolnick, B; Gur, R E; Benson, D M

    1993-11-01

    Using 133Xe regional cerebral blood flow (CBF) imaging, two male groups having high and low hypnotic susceptibility were compared in waking and after hypnotic induction, while at rest and while experiencing ischemic pain to both arms under two conditions: attend to pain and suggested analgesia. Differences between low and highly-hypnotizable persons were observed during all hypnosis conditions: only highly-hypnotizable persons showed a significant increase in overall CBF, suggesting that hypnosis requires cognitive effort. As anticipated, ischemic pain produced CBF increases in the somatosensory region. Of major theoretical interest is a highly-significant bilateral CBF activation of the orbito-frontal cortex in the highly-hypnotizable group only during hypnotic analgesia. During hypnotic analgesia, highly-hypnotizable persons showed CBF increase over the somatosensory cortex, while low-hypnotizable persons showed decreases. Research is supportive of a neuropsychophysiological model of hypnosis (Crawford, 1991; Crawford and Gruzelier, 1992) and suggests that hypnotic analgesia involves the supervisory, attentional control system of the far-frontal cortex in a topographically specific inhibitory feedback circuit that cooperates in the regulation of thalamocortical activities. PMID:8166843

  15. Single-photon tomographic determination of regional cerebral blood flow in psychiatric disorders

    SciTech Connect

    Devous, M.D. Sr.; Rush, A.J.; Schlesser, M.A.; Debus, J.; Raese, J.D.; Chehabi, H.H.; Bonte, F.J.

    1984-01-01

    Regional cerebral blood flow (rCBF) was measured by single-photon emission computed tomography (SPECT) of 133-Xe washout in 29 normal volunteers, 22 unipolar endogenous depressives (UPE), 9 unipolar nonendogenous depressives (UPNE), 13 bipolar depressed patients (BPD), and 14 schizophrenic patients (SCHZ). RCBF was measured 2 and 6 cm above and parallel to the cantho-meatal line and quantitated in 14 gray matter regions. Most subjects were drug-free for 4-14 days. Diagnoses were made by experienced clinicians employing the Research Diagnostic Criteria, the Hamilton Rating Scale, and the dexamethasone suppression test. SCHZ were rated with the Brief Psychiatric Rating Scale. UPE had reduced flow compared to normals in the right parietal and temporal lobes and a nonsignificant trend toward left temporal flow reductions. UPNE were not different from normal or other patient groups. BPD had significant flow elevations in the left hemisphere relative to normal, and in both hemispheres relative to UPE. SCHZ were not significantly different from normal or other patient groups. Anterior-posterior flow shifts were evaluated by subtracting parietal or temporal flows from frontal flows. SCHZ demonstrated a greater posterior shift (lower relative frontal lobe flow) in comparison to both UPE and UPNE. The most significant regional flow abnormalities were observed as frontal flow reductions in individual SCHZ, although these were not significant in the whole group in comparison to normal.

  16. Low-energy degassing mechanisms for a fluid-based radioxenon detection system

    SciTech Connect

    Russ, W.R.; Stuenkel, D.O.; Valentine, J.D.; Gross, K.C.

    1998-09-01

    A method to concentrate heavy noble gases from the atmosphere using certain organic fluids is being developed. To use this technique in a system to monitor the atmosphere for important noble gas fission products (Xe-131, Xe-131m, Xe-133, Xe-133m, and Xe-135) generated by nuclear testing, the radionuclides captured in the fluid must either be detected in the fluid or degassed. This study presents experimental results for a number of possible degassing methods, including heating bubbling with a purge gas, ultrasonic agitation, vacuum, and combinations thereof. Methods were evaluated for energy and time requirements and dilution of the degas product. Initial experiments indicate that in addition to overcoming the standard desorption process dictated by partial pressures per Henry`s Law, a capture mechanism must also be overcome to degas. Some type of agitation, thermal or mechanical, can be used to release weakly trapped gas atoms from the fluid, while diffusional mass transfer can be enhanced through entrainment with a purge gas or use of a vacuum. Ultrasonic agitation of a thin film in a strong vacuum has been shown to be the most effective method of those tested. Implementation of an efficient degas system, along with an absorption system and radioxenon detector could result in an ultrasensitive fluid-based radioxenon measurement system that is more portable, less expensive, and simpler than charcoal-based systems which use cryogenic techniques.

  17. Cerebral blood flow in patients (PTS) exposed to neurotoxic chemicals

    SciTech Connect

    Heuser, G.; Mena, I.; Thomas, C.

    1994-05-01

    Exposure to neurotoxic chemicals as pesticides, glues, solvents, etc. are known to induce neurologic and psychiatric symptomatology. We report on 72 pts, 33 young pts, 8 males, and 26 females, age 55 (7) yrs, 15 of them exposed to pesticides, and 37 to solvents. They were studied with quantitative and qualitative analysis of rCBF performed with 30 mCi of Xe-133 (Xe) by inhalation followed by 30 mCi of Tc-HMPAO given IV. Imaging was performed with a brain dedicated system, and distribution of rCBF was assessed with automatic ROI definition, and HMPAO normalized to maximal pixel activity in the brain. Results of Xe rCBF are expressed as mean and (S.D.) in ml/min/100g, and HMPAO as mean and (S.D.) uptake per ROI and compared with age-matched controls, 10 young and 20 elderly individuals, and also to a group of 36 elderly chronic fatigue pts (CFS), and 26 depression pts. CBF was diminished in young and elderly, 45 (7) and 40 (7) ml/min 100g, p<0.02 for both groups. Thus we conclude that pts exposed to chemicals present with diminished CBF, worse in elderly in the right dorsal frontal and parietal lobes, and in young, in left dorsal frontal and temporal lobes. These findings are significantly different from observations in pts and chronic fatigue and depression.

  18. Evaluation of radionuclide dose-calibrator measurements

    SciTech Connect

    Paras, P.; Comer, F.M.; Demeis, F.; Coursey, B.M.; Calhoun, J.M.; Golas, D.B.

    1986-01-01

    Performance data for radionuclide dose calibrators, which are primarily ionization chambers, are scarce. Large deviations have occasionally been reported, particularly for low photon energies, i.e., emissions from /sup 201/Tl, /sup 133/Xe. The volunteer user program (QB series) of the College of American Pathologists (CAP) (laboratory intercomparison quality control), supported by the US National Bureau of Standards (NBS), for quality control of dose calibrators was suspended. The Atomic Industrial Forum (AIF) has a quality control program among radiopharmaceutical manufacturers but there is no user program in the US at this time, and the performance of dose calibrators in the field is not known. In addition, a number of professionals expressed a strong feeling for the continuation of the CAP program and the availability of standards for dose calibrators from NBS. The objective of this study is twofold: (a) to evaluate the accuracy of dose calibrator measurements for individual patient radioactivity administered doses, and (b) to provide certified sources of certain radionuclides to calibrate the instruments for these radionuclides.

  19. Cognitive performance correlates with cerebrovascular impairments in multi-infarct dementia

    SciTech Connect

    Judd, B.W.; Meyer, J.S.; Rogers, R.L.; Gandhi, S.; Tanahashi, N.; Mortel, K.F.; Tawaklna, T.

    1986-05-01

    Cerebral blood flow (CBF) was measured by the /sup 133/Xe inhalation method in patients with multi-infarct dementia (MID, N = 26), Alzheimer's dementia (AD, N = 19), and among age-matched, neurologically normal, healthy volunteers (N = 26). Cognitive performance was assessed in all subjects using the Cognitive Capacity Screening Examination (CCSE). Cerebral vasomotor responses were calculated from differences in values of mean hemispheric gray matter blood flow (Delta CBF) measured during inhalation of 100% oxygen (hyperoxia) compared with CBF measured while breathing room air. Significant correlations were found between CCSE performance and vasomotor responsiveness in patients with MID (P less than .01), but not in patients with AD or in neurologically normal volunteers. Loss of vasomotor responsiveness is an indicator of cerebrovascular disease with rigidity and/or loss of reactivity of cerebral vessels, which impairs cerebrovascular responses to situational demands and predisposes to cerebral ischemia. Loss of cerebral vasomotor responsiveness among MID patients, which is a biologic marker of cerebrovascular disease, provides confirmatory evidence of the vascular etiology of MID and assists in separating MID from AD patients.

  20. Prospective analysis of long term control of mild hypertension on cerebral blood flow

    SciTech Connect

    Meyer, J.S.; Rogers, R.L.; Mortel, K.F.

    1985-11-01

    A group of 12 otherwise normal elderly volunteers (mean age = 69.8 years), were detected to have mild hypertension. Cerebral blood flow (CBF) values were measured using 133Xe inhalation method prior to initiating medical treatment and repeated at 6, 12, 24 and 36 months after BP was adequately controlled and restored to normal (below 150/90). Results indicate that CBF values increased markedly during follow-up intervals at 6, 12 and 24 months but not at 36 months. Hypertension is known to be a risk factor for stroke and 4 of the 12 subjects subsequently developed symptoms of cerebrovascular disease (stroke, multi-infarct dementia or transient ischemic attacks) despite control of hypertension. Analyses separating asymptomatic and symptomatic groups indicated that the eight asymptomatic patients continued to maintain increased CBF levels throughout the entire three year interval, whereas the 4 symptomatic patients developed declines in CBF which began, and progressively decreased below the initial pretreatment values, during the second and third years.

  1. Radionuclide evaluation of lung trauma

    SciTech Connect

    Lull, R.J.; Tatum, J.L.; Sugerman, H.J.; Hartshorne, M.F.; Boll, D.A.; Kaplan, K.A.

    1983-07-01

    Nuclear medicine imaging procedures can play a significant role in evaluating the pulmonary complications that are seen in trauma patients. A quantitative method for measuring increased pulmonary capillary permeability that uses Tc-99m HSA allows early diagnosis of acute respiratory distress syndrome (ARDS) and accurately differentiates this condition from pneumonia or cardiogenic pulmonary edema. This technique may be of great value in following the response to therapy. The use of 133Xe to diagnose inhalation injury remains an important diagnostic tool, particularly at hospitals with specialized burn units. Regional decreases in ventilation-perfusion images reliably localize aspirated foreign bodies. Radionuclide techniques that are used to demonstrate gastropulmonary aspiration remain controversial and require further clinical evaluation. Pulmonary perfusion imaging, although nonspecific, may provide the earliest clue for correct diagnosis of fat embolism, air embolism, contusion, or laceration. Furthermore, the possibility of perfusion abnormality due to these uncommon conditions must be remembered whenever trauma patients are evaluated for pulmonary thromboembolism with scintigraphy. Occasionally, liver or spleen scintigraphy may be the most appropriate procedure when penetrating chest trauma also involves these subdiaphragmatic organs.

  2. Cardiovascular reflexes during rest and exercise modified by gravitational stresses

    NASA Astrophysics Data System (ADS)

    Bonde-petersen, Flemming

    The hypotheses tested were whether variations in central venous pressure via the low pressure baroreceptors would take over or modify the arterial baroreceptor function, and further to which extent local and "whole body" hydrostatic stresses influence blood flow distribution. We investigated total forearm and skin blood flow (venous occlusion plethysmography and 133-Xe clearance) and cardiac output (rebreathing method) among other parameters. Hypo-and hypergravitational stresses were simulated by LBNP, LBPP, water immersion and lowering of the arm. The changes in flow distribution in the arm were ascribed to arterial baroreceptor function and not to low pressure baroreceptor activity. The enhancement of venous return during water immersion increased exercise tolerance during heat stress presumably due both to increased stroke volume and decreased venous pooling. The response to sustained handgrip exercise during LBNP and LBPP was not different from control measurements and the effects explained by arterial baroreceptor function. Application of exercise and local hydrostatic stresses in combination with gravitational stresses represent an interesting model for further study of the mechanisms behind the distribution of cardiac output to the peripheral organs.

  3. Combined technetium radioisotope penile plethysmography and xenon washout: A technique for evaluating corpora cavernosal inflow and outflow during early tumescence

    SciTech Connect

    Schwartz, A.N.; Graham, M.M. )

    1991-03-01

    Combined technetium radioisotope penile plethysmography and xenon washout is a new technique that measures both corporal arterial inflow and venous sinusoidal outflow during early tumescence in patients with erectile dysfunction. Fourteen patients were studied using 99mTc-RBCs to measure inflow and 133Xe or 127Xe in saline to measure outflow. Tumescence was induced by injecting papaverine intracorporally. Peak corporal rates corrected for inflow (r = 0.88) and uncorrected for outflow (r = 0.91) and change in volume over 2 min centered around peak inflow (r = 0.96) all correlated with angiography. Outflow measurements did not correlate with intracorporal resistance. Thus, outflow rates alone could not be used to predict venous sinusoidal competence. Normal inflow rate is greater than 20 ml/min; probable normal 12-20; indeterminate inflow 7-12; and abnormal inflow less than 7 ml/min. Technetium-99m radioisotope penile plethysmography and xenon washout can be performed together and both provide a method for simultaneously evaluating the relationship between corporal inflow and outflow rates in patients with erectile dysfunction.

  4. Cerebral blood flow tomography with xenon-133

    SciTech Connect

    Lassen, N.A.

    1985-10-01

    Cerebral blood flow (CBF) can be measured tomographically by inhalation of Xenon-/sup 133/. The calculation is based on taking a sequence of tomograms during the wash-in and wash-out phase of the tracer. Due to the dynamic nature of the process, a highly sensitive and fast moving single photon emission computed tomograph (SPECT) is required. Two brain-dedicated SPECT systems designed for this purpose are mentioned, and the method is described with special reference to the limitations inherent in the soft energy of the 133Xe primary photons. CBF tomography can be used for a multitude of clinical and investigative purposes. This article discusses in particular its use for the selection of patients with carotid occlusion for extracranial/intracranial bypass surgery, for detection of severe arterial spasm after aneurysm bleeding, and for detection of low flow areas during severe migraine attacks. The use of other tracers for CBF tomography using SPECT is summarized with emphasis on the /sup 99m/Tc chelates that freely pass the intact blood-brain barrier. The highly sensitive brain-dedicated SPECT systems described are a prerequisite for achieving high resolution tomograms with such tracers.

  5. Radioxenon spiked air.

    PubMed

    Watrous, Matthew G; Delmore, James E; Hague, Robert K; Houghton, Tracy P; Jenson, Douglas D; Mann, Nick R

    2015-12-01

    Four of the radioactive xenon isotopes ((131m)Xe, (133m)Xe, (133)Xe and (135)Xe) with half-lives ranging from 9 h to 12 days are produced from nuclear fission and can be detected from days to weeks following their production and release. Being inert gases, they are readily transported through the atmosphere. Sources for release of radioactive xenon isotopes include operating nuclear reactors via leaks in fuel rods, medical isotope production facilities, and nuclear weapons' detonations. They are not normally released from fuel reprocessing due to the short half-lives. The Comprehensive Nuclear-Test-Ban Treaty has led to creation of the International Monitoring System. The International Monitoring System, when fully implemented, will consist of one component with 40 stations monitoring radioactive xenon around the globe. Monitoring these radioactive xenon isotopes is important to the Comprehensive Nuclear-Test-Ban Treaty in determining whether a seismically detected event is or is not a nuclear detonation. A variety of radioactive xenon quality control check standards, quantitatively spiked into various gas matrices, could be used to demonstrate that these stations are operating on the same basis in order to bolster defensibility of data across the International Monitoring System. This paper focuses on Idaho National Laboratory's capability to produce three of the xenon isotopes in pure form and the use of the four xenon isotopes in various combinations to produce radioactive xenon spiked air samples that could be subsequently distributed to participating facilities.

  6. Maximum reasonable radioxenon releases from medical isotope production facilities and their effect on monitoring nuclear explosions.

    PubMed

    Bowyer, Theodore W; Kephart, Rosara; Eslinger, Paul W; Friese, Judah I; Miley, Harry S; Saey, Paul R J

    2013-01-01

    Fission gases such as (133)Xe are used extensively for monitoring the world for signs of nuclear testing in systems such as the International Monitoring System (IMS). These gases are also produced by nuclear reactors and by fission production of (99)Mo for medical use. Recently, medical isotope production facilities have been identified as the major contributor to the background of radioactive xenon isotopes (radioxenon) in the atmosphere (Stocki et al., 2005; Saey, 2009). These releases pose a potential future problem for monitoring nuclear explosions if not addressed. As a starting point, a maximum acceptable daily xenon emission rate was calculated, that is both scientifically defendable as not adversely affecting the IMS, but also consistent with what is possible to achieve in an operational environment. This study concludes that an emission of 5 × 10(9) Bq/day from a medical isotope production facility would be both an acceptable upper limit from the perspective of minimal impact to monitoring stations, but also appears to be an achievable limit for large isotope producers.

  7. Atmospheric Radioxenon Measurements in North Las Vegas, NV

    SciTech Connect

    Milbrath, Brian D.; Cooper, Matthew W.; Lidey, Lance S.; Bowyer, Ted W.; Hayes, James C.; McIntyre, Justin I.; Karr, L.; Shafer, D.; Tappen, J.

    2006-07-31

    PNNL deployed the ARSA radioxenon measurement system in North Las Vegas for two weeks in February and March 2006 for the purpose of measuring the radioxenon background at a level of sensitivity much higher than previously done in the vicinity of the NTS. The measurements establish what might be expected if future measurements are taken at NTS itself. The measurements are also relevant to test site readiness. A second detector, the PEMS, built and operated by DRI, was deployed in conjunction with the ARSA and contained a PIC, aerosol collection filters, and meteorological sensors. Originally, measurements were also to be performed at Mercury, NV on the NTS, but these were canceled due to initial equipment problems with the ARSA detector. Some of the radioxenon measurements detected 133Xe at levels up to 3 mBq/m3. This concentration of radioxenon is consistent with the observation of low levels of radioxenon emanating from distance nuclear reactors. Previous measurements in areas of high nuclear reactor concentration have shown similar results, but the western US, in general, does not have many nuclear reactors. Measurements of the wind direction indicate that the air carrying the radioxenon came from south of the detector and not from the NTS.

  8. Radioxenon Atmospheric Measurements in North Las Vegas

    SciTech Connect

    Milbrath, Brian D.; Cooper, Matthew W.; Lidey, Lance S.; Bowyer, Ted W.; Hayes, James C.; McIntyre, Justin I.; Karr, L.; Shafer, David S.; Tappen, J.

    2007-09-25

    Pacific Northwest National Laboratory (PNNL) deployed the Automated Radioxenon Sampler/Analyzer (ARSA) in North Las Vegas for two weeks in February and March 2006 for the purpose of measuring the radioxenon background at a level of sensitivity much higher than previously done in the vicinity of the Nevada Test Site (NTS). The measurements establish what might be expected if future measurements are taken at NTS itself and investigate improved methods of environmental monitoring of NTS for test site readiness. Also, such radioxenon measurements have not previously been performed in a United States location considered to be as remote from nuclear reactors. A second detector, the Portable Environmental Monitoring Station (PEMS), built and operated by the Desert Research Institute (DRI), was deployed in conjunction with the ARSA and contained a pressure ion chamber, aerosol collection filters, and meteorological sensors. Some of the radioxenon measurements detected 133Xe at levels up to 3 mBq/m3. This concentration of radioxenon is consistent with the observation of low levels of radioxenon emanating from distance nuclear reactors. Previous measurements in areas of high nuclear reactor concentration have shown similar results, but the western US, in general, does not have many nuclear reactors. Measurements of the wind direction indicate that the air carrying the radioxenon came from south of the detector and not from the NTS.

  9. Study of medical isotope production facility stack emissions and noble gas isotopic signature using automatic gamma-spectra analysis platform

    NASA Astrophysics Data System (ADS)

    Zhang, Weihua; Hoffmann, Emmy; Ungar, Kurt; Dolinar, George; Miley, Harry; Mekarski, Pawel; Schrom, Brian; Hoffman, Ian; Lawrie, Ryan; Loosz, Tom

    2013-04-01

    The nuclear industry emissions of the four CTBT (Comprehensive Nuclear-Test-Ban Treaty) relevant radioxenon isotopes are unavoidably detected by the IMS along with possible treaty violations. Another civil source of radioxenon emissions which contributes to the global background is radiopharmaceutical production companies. To better understand the source terms of these background emissions, a joint project between HC, ANSTO, PNNL and CRL was formed to install real-time detection systems to support 135Xe, 133Xe, 131mXe and 133mXe measurements at the ANSTO and CRL 99Mo production facility stacks as well as the CANDU (CANada Deuterium Uranium) primary coolant monitoring system at CRL. At each site, high resolution gamma spectra were collected every 15 minutes using a HPGe detector to continuously monitor a bypass feed from the stack or CANDU primary coolant system as it passed through a sampling cell. HC also conducted atmospheric monitoring for radioxenon at approximately 200 km distant from CRL. A program was written to transfer each spectrum into a text file format suitable for the automatic gamma-spectra analysis platform and then email the file to a server. Once the email was received by the server, it was automatically analysed with the gamma-spectrum software UniSampo/Shaman to perform radionuclide identification and activity calculation for a large number of gamma-spectra in a short period of time (less than 10 seconds per spectrum). The results of nuclide activity together with other spectrum parameters were saved into the Linssi database. This database contains a large amount of radionuclide information which is a valuable resource for the analysis of radionuclide distribution within the noble gas fission product emissions. The results could be useful to identify the specific mechanisms of the activity release. The isotopic signatures of the various radioxenon species can be determined as a function of release time. Comparison of 133mXe and 133Xe activity

  10. Unexpected bias in NIST 4πγ ionization chamber measurements.

    PubMed

    Unterweger, M P; Fitzgerald, R

    2012-09-01

    In January of 2010, it was discovered that the source holder used for calibrations in the NIST 4πγ ionization chamber (IC) has not been stable. The positioning ring that determines the height of the sample in the reentrant tube of the IC has slowly shifted during 35 years of use. This has led to a slow change in the calibration factors for the various radionuclides measured by this instrument. The changes are dependent on γ-ray energy and the time the IC was calibrated for a given radionuclide. A review of the historic data with regard to when the calibrations were done has enabled us to approximate the magnitude of the changes with time. This requires a number of assumptions, and corresponding uncertainty components, including whether the changes in height were gradual or in steps as will be shown in drawings of sample holder. For calibrations the changes in calibration factors have been most significant for low energy gamma emitters such as (133)Xe, (241)Am, (125)I and (85)Kr. The corrections to previous calibrations can be approximated and the results corrected with an increase in the overall uncertainty. At present we are recalibrating the IC based on new primary measurements of the radionuclides measured on the IC. Likewise we have been calibrating a new automated ionization-chamber system. A bigger problem is the significant number of half-life results NIST has published over the last 35 years that are based on IC measurements. The effect on half-life is largest for long-lived radionuclei, especially low-energy γ-ray emitters. This presentation will review our results and recommend changes in values and/or uncertainties. Any recommendation for withdrawal of any results will also be undertaken.

  11. Cerebral blood flow decreases with time whereas cerebral oxygen consumption remains stable during hypothermic cardiopulmonary bypass in humans

    SciTech Connect

    Prough, D.S.; Rogers, A.T.; Stump, D.A.; Roy, R.C.; Cordell, A.R.; Phipps, J.; Taylor, C.L. )

    1991-02-01

    Recent investigations demonstrate that cerebral blood flow (CBF) progressively declines during hypothermic, nonpulsatile cardiopulmonary bypass (CPB). If CBF declines because of brain cooling, the cerebral metabolic rate for oxygen (CMRO2) should decline in parallel with the reduction in CBF. Therefore we studied the response of CBF, the cerebral arteriovenous oxygen content difference (A-VDcereO2) and CMRO2 as a function of the duration of CPB in humans. To do this, we compared the cerebrovascular response to changes in the PaCO2. Because sequential CBF measurements using xenon 133 (133Xe) clearance must be separated by 15-25 min, we hypothesized that a time-dependent decline in CBF would accentuate the CBF reduction caused by a decrease in PaCO2, but would blunt the CBF increase associated with a rise in PaCO2. We measured CBF in 25 patients and calculated the cerebral arteriovenous oxygen content difference using radial arterial and jugular venous bulb blood samples. Patients were randomly assigned to management within either a lower (32-48 mm Hg) or higher (50-71 mm Hg) range of PaCO2 uncorrected for temperature. Each patient underwent two randomly ordered sets of measurements, one at a lower PaCO2 and the other at a higher PaCO2 within the respective ranges. Cerebrovascular responsiveness to changes in PaCO2 was calculated as specific reactivity (SR), the change in CBF divided by the change in PaCO2, expressed in mL.100 g-1.min-1.mm Hg-1.

  12. International challenge to predict the impact of radioxenon releases from medical isotope production on a comprehensive nuclear test ban treaty sampling station.

    PubMed

    Eslinger, Paul W; Bowyer, Ted W; Achim, Pascal; Chai, Tianfeng; Deconninck, Benoit; Freeman, Katie; Generoso, Sylvia; Hayes, Philip; Heidmann, Verena; Hoffman, Ian; Kijima, Yuichi; Krysta, Monika; Malo, Alain; Maurer, Christian; Ngan, Fantine; Robins, Peter; Ross, J Ole; Saunier, Olivier; Schlosser, Clemens; Schöppner, Michael; Schrom, Brian T; Seibert, Petra; Stein, Ariel F; Ungar, Kurt; Yi, Jing

    2016-06-01

    The International Monitoring System (IMS) is part of the verification regime for the Comprehensive Nuclear-Test-Ban-Treaty Organization (CTBTO). At entry-into-force, half of the 80 radionuclide stations will be able to measure concentrations of several radioactive xenon isotopes produced in nuclear explosions, and then the full network may be populated with xenon monitoring afterward. An understanding of natural and man-made radionuclide backgrounds can be used in accordance with the provisions of the treaty (such as event screening criteria in Annex 2 to the Protocol of the Treaty) for the effective implementation of the verification regime. Fission-based production of (99)Mo for medical purposes also generates nuisance radioxenon isotopes that are usually vented to the atmosphere. One of the ways to account for the effect emissions from medical isotope production has on radionuclide samples from the IMS is to use stack monitoring data, if they are available, and atmospheric transport modeling. Recently, individuals from seven nations participated in a challenge exercise that used atmospheric transport modeling to predict the time-history of (133)Xe concentration measurements at the IMS radionuclide station in Germany using stack monitoring data from a medical isotope production facility in Belgium. Participants received only stack monitoring data and used the atmospheric transport model and meteorological data of their choice. Some of the models predicted the highest measured concentrations quite well. A model comparison rank and ensemble analysis suggests that combining multiple models may provide more accurate predicted concentrations than any single model. None of the submissions based only on the stack monitoring data predicted the small measured concentrations very well. Modeling of sources by other nuclear facilities with smaller releases than medical isotope production facilities may be important in understanding how to discriminate those releases from

  13. Retention of {sup 99m}{Tc}-bicisate in the human brain after intracarotid injection

    SciTech Connect

    Friberg, L.; Lassen, N.A.; Andersen, A.R.; Dam, M.

    1994-01-01

    {sup 99m}{Tc}-bicisate (ECD) was injected as a bolus into the internal carotid artery, and cerebral uptake and retention were recorded with fast-rotating single photon emission computed tomography (SPECT) equipment in four patients suffering from temporal lobe epilepsy. Quantitative regional cerebral blood flow (rCBF) was measured tomographically with the {sup 133}Xe inhalation technique. The authors applied a three-compartment kinetic model and algorithms modified from a previous analysis of {sup 99m}{Tc} d,l-hexamethylpropyleneamine oxide (HM-PAO) kinetics. The bicisate brain uptake and retention curve was very similar to that of HM-PAO, and it can be described by a triexponential function including an initial steep component representing the vascular transmitted spike, a second less steep component representing back-diffusion from brain tissue to blood, and a third, very slow component, representing the very slow loss due to incomplete retention of the deesterified hydrophilic metabolites. Computerized curve-fitting on data from three patients gave average kinetic values for the first-passage (unilateral) extraction of E = 0.60 (range, 0.59-0.61); the overall retained fraction of the tracer supplied was R = 0.44 (0.43-0.45), and the conversion/clearance ratio was {alpha} = k{sub 3}/k{sub 2} = 2.59 (2.38-2.77). This {alpha} is higher than that for HM-PAO, and therefore bicisate uptake as a function of blood flow is more linear than in HM-PAO. Less correction for backdiffusion is therefore needed. From 1 to 24 h there was an average loss of hydrophilic tracer of 3.5%/h, but the late distribution images were essentially unchanged over time, pointing to practically the same rate of loss in all regions. 18 refs., 5 figs., 2 tabs.

  14. Cerebral autoregulation and flow/metabolism coupling during cardiopulmonary bypass: the influence of PaCO/sub 2/

    SciTech Connect

    Murkin, J.M.; Farrar, J.K.; Tweed, W.A.; McKenzie, F.N.; Guiraudon, G.

    1987-09-01

    Measurement of /sup 133/Xe clearance and effluent cerebral venous blood sampling were used in 38 patients to determine the effects of cardiopulmonary bypass, and of maintaining temperature corrected or noncorrected PaCO/sub 2/ at 40 mm Hg on regulation of cerebral blood flow (CBF) and flow/metabolism coupling. After induction of anesthesia with diazepam and fentanyl, mean CBF was 25 ml X 100 g-1 X min-1 and cerebral oxygen consumption, 1.67 ml X 100 g-1 X min-1. Cerebral oxygen consumption during nonpulsatile cardiopulmonary bypass at 26 degrees C was reduced to 0.42 ml X 100 g-1 X min-1 in both groups. CBF was reduced to 14-15 ml X 100 g-1 X min-1 in the non-temperature-corrected group (n = 21), was independent of cerebral perfusion pressure over the range of 20-100 mm Hg, but correlated with cerebral oxygen consumption. In the temperature-corrected group (n = 17), CBF varied from 22 to 32 ml X 100 g-1 X min-1, and flow/metabolism coupling was not maintained (i.e., CBF and cerebral oxygen consumption varied independently). However, variation in CBF correlated significantly with cerebral perfusion pressure over the pressure range of 15-95 mm Hg. This study demonstrates a profound reduction in cerebral oxygen consumption during hypothermic nonpulsatile cardiopulmonary bypass. When a non-temperature-corrected PaCO/sub 2/ of approximately 40 mm Hg was maintained, CBF was lower, and analysis of pooled data suggested that CBF regulation was better preserved, i.e., CBF was independent of pressure changes and dependent upon cerebral oxygen consumption.

  15. Effects of cardiac oscillations and lung volume on acinar gas mixing during apnea

    SciTech Connect

    Mackenzie, C.F.; Skacel, M.; Barnas, G.M.; Brampton, W.J.; Alana, C.A. )

    1990-05-01

    We evaluated the importance of cardiogenic gas mixing in the acini of 13 dogs during 2 min of apnea. 133Xe (1-2 mCi in 4 ml of saline) was injected into an alveolar region through an occluded pulmonary artery branch, and washout was measured by gamma scintillation scanning during continued occlusion or with blood flow reinstated. The monoexponential rate constant for Xe washout (XeW) was -0.4 +/- 0.08 (SE) min-1 at functional residual capacity (FRC) with no blood flow in the injected region. It decreased by more than half at lung volumes 500 ml above and 392 ml below FRC. With intact pulmonary blood flow, XeW was -1.0 +/- 0.08 (SE) min-1 at FRC, and it increased with decreasing lung volume. However, if calculated Xe uptake by the blood was subtracted from the XeW measured with blood flow intact, resulting values at FRC and at FRC + 500 ml were not different from XeW with no blood flow. Reasonable calculation of Xe blood uptake at 392 ml below FRC was not possible because airway closure, increased shunt, and other factors affect XeW. After death, no significant XeW could be measured, which suggests that XeW caused by molecular diffusion was small. We conclude that (1) the effect of heart motion on the lung parenchyma increases acinar gas mixing during apnea, (2) this effect diminishes above or below FRC, and (3) there is probably no direct effect of pulmonary vascular pulsatility on acinar gas mixing.

  16. Negative neurofunctional effects of frequency, depth and environment in recreational scuba diving: the Geneva "memory dive" study

    PubMed Central

    Slosman, D; de Ribaupierre, S; Chicherio, C; Ludwig, C; Montandon, M; Allaoua, M; Genton, L; Pichard, C; Grousset, A; Mayer, E; Annoni, J; de Ribaupierre, A

    2004-01-01

    Objectives: To explore relationships between scuba diving activity, brain, and behaviour, and more specifically between global cerebral blood flow (CBF) or cognitive performance and total, annual, or last 6 months' frequencies, for standard dives or dives performed below 40 m, in cold water or warm sea geographical environments. Methods: A prospective cohort study was used to examine divers from diving clubs around Lac Léman and Geneva University Hospital. The subjects were 215 healthy recreational divers (diving with self-contained underwater breathing apparatus). Main outcome measures were: measurement of global CBF by 133Xe SPECT (single photon emission computed tomography); psychometric and neuropsychological tests to assess perceptual-motor abilities, spatial discrimination, attentional resources, executive functioning, and memory; evaluation of scuba diving activity by questionnaire focusing on number and maximum depth of dives and geographical site of the diving activity (cold water v warm water); and body composition analyses (BMI). Results: (1) A negative influence of depth of dives on CBF and its combined effect with BMI and age was found. (2) A specific diving environment (more than 80% of dives in lakes) had a negative effect on CBF. (3) Depth and number of dives had a negative influence on cognitive performance (speed, flexibility and inhibition processing in attentional tasks). (4) A negative effect of a specific diving environment on cognitive performance (flexibility and inhibition components) was found. Conclusions: Scuba diving may have long-term negative neurofunctional effects when performed in extreme conditions, namely cold water, with more than 100 dives per year, and maximal depth below 40 m. PMID:15039241

  17. Response of cerebral blood flow to changes in carbon dioxide tension during hypothermic cardiopulmonary bypass

    SciTech Connect

    Prough, D.S.; Stump, D.A.; Roy, R.C.; Gravlee, G.P.; Williams, T.; Mills, S.A.; Hinshelwood, L.; Howard, G.

    1986-05-01

    Changes in cerebral blood flow (CBF) in response to changes in PaCO/sub 2/ were measured by intraaortic injection of /sup 133/Xe in 12 patients during hypothermic (23-30 degrees C) cardiopulmonary bypass. In each patient, CBF was determined at two randomly ordered levels of PaCO/sub 2/ obtained by varying the rate of gas inflow into the pump oxygenator (Group I, n = 6) or by varying the percentage of CO/sub 2/ added to the gas inflow (Group II, n = 6). Nasopharyngeal temperature, mean arterial pressure, pump-oxygenator flow, and hematocrit were maintained within a narrow range. In group I, a PaCO/sub 2/ (uncorrected for body temperature) of 36 +/- 4 mmHg (mean +/- SD) was associated with a CBF of 13 +/- 5 ml X 100 g-1 X min-1, while a PaCO/sub 2/ of 42 +/- 4 mmHg was associated with a CBF of 19 +/- 10 ml X 100 g-1 X min-1. In group II, a PaCO/sub 2/ of 47 +/- 3 mmHg was associated with a CBF of 20 +/- 8 ml X 100 g-1 X min-1, and a PaCO/sub 2/ of 53 +/- 3 mmHg was associated with a CBF of 26 +/- 9 ml X 100 g-1 X min-1. Within group I, the difference in CBF was significant (P less than 0.05); within group II, the difference in CBF was significant at the P less than 0.002 level. All CBF measurements were lower than those reported for normothermic, unanesthetized subjects of similar age.

  18. Effects of midazolam on cerebral blood flow in human volunteers

    SciTech Connect

    Forster, A.; Juge, O.; Morel, D.

    1982-06-01

    The effects of intravenously administered midazolam on cerebral blood flow were evaluated in eight healthy volunteers using the /sup 133/Xe inhalation technique. Six minutes after an intravenous dose of 0.15 mg/kg midazolam, the cerebral blood flow decreased significantly (P less than 0.001) from a value of 40.6 +/- 3.3 to a value of 27.0 +/- 5.0 ml . 100 g-1 . min-1. Cerebrovascular resistance (CVR) increased from 2.8 +/- 0.2 to 3.9 to 0.6 mmHg/(ml . 100 g-1 . min-1)(P less than 0.001). Mean arterial blood pressure decreased significantly (P less than 0.05) from 117 +/- 8 to 109 +/- 9 mmHg and arterial carbon dioxide tension increased from 33.9 +/- 2.3 to 38.6 +/- 3.2 mmHg (P less than 0.05). Arterial oxygen tension remained stable throughout the study, 484 +/- 95 mmHg before the administration of midazolam and 453 +/- 76 mmHg after. All the subjects slept after the injection of the drug and had anterograde amnesia of 24.5 +/- 5 min. The decrease in mean arterial blood pressure was probably not important since it remained in the physiologic range for cerebral blood flow autoregulation. The increase in arterial carbon dioxide tension observed after the midazolam injection may have partially counteracted the effect of this new benzodiazepine on cerebral blood flow. Our data suggest that midazolam might be a safe agent to use for the induction of anethesia in neurosurgical patients with intracranial hypertension.

  19. Technegas: A medical application of {sup 99m}Tc for the study of buckyballs, blood clots, lung disease and AIDS

    SciTech Connect

    Willett, G.D.; Dance, I.G.; Fisher, K.J.; Burch, W.M.; Dasaklis, C.; Mackey, D.W.J.

    1994-12-31

    Radionuclide studies of lung disease have been greatly enhanced by the introduction of an Australian invention; the Technegas generator. The properties of the {open_quotes}dry radio-aerosols{close_quotes} produced by this device ensure lung images superior to those from true radio-gases such as {sup 133}Xe with the additional advantage of employing {sup 99m}Tc, the most widespread radionuclide agent. A Technegas lung scan can enable identification of pulmonary mebolism (an immediately life threatening condition) emphysema and chronic obstructive lung disease. A simple modification to the generator gas mixture produces Pertechnegas an agent useful in studies of the integrity of the alveolar epithelial membrane in immunosuppressed patients such as transplants and AIDS. Although these agents are now common in Australia and Europe, little has been proven of their chemical composites. Technegas is formed by the initial evaporation of ({sup 99m}Tc) sodium pertechnetate with the subsequent sublimation of carbon from a disposable graphite crucible at {approximately}2500{degrees}C in an atmosphere of 100% argon. {sup 99m}Tc atoms are lifted off with the crystalline layers of graphite during the vaporization. Technegas then possibly consists of {sup 99m}Tc based metallo-fullerenes and fullerenes. Technegas has an effective half life in the lung very similar to the physical half life of Technetium (6 hours) regardless of clinical condition; a result which suggests that Technegas contains endohedral fullerenes. Pertechnegas is created in an atmosphere of 97% Ar 3% O{sub 2} and has an effective half life in the lung of less than 15 minutes.

  20. Assessment of demented patients by dynamic SPECT of inhaled xenon-133

    SciTech Connect

    Komatani, A.; Yamaguchi, K.; Sugai, Y.; Takanashi, T.; Kera, M.; Shinohara, M.; Kawakatsu, S.

    1988-10-01

    We studied the potential for using dynamic single photon emission computed tomography of inhaled xenon-133 (/sup 133/Xe) gas in the assessment of demented patients. An advanced ring-type single photon emission computed tomography (SPECT) HEADTOME with improved spatial resolution (15 mm in full width at half maximum (FWHM)) was used for tomographic measurement of regional cerebral blood flow (rCBF). All 34 patients underwent a detailed psychiatric examination and x-ray computed tomography scan, and matched research criteria for Alzheimer's disease (n = 13), senile dementia of the Alzheimer type (n = 9), or multi-infarct dementia (n = 12). In comparison with a senile control group (n = 7), mean CBF of both the whole brain and the temporo-parietal region was significantly less in the Alzheimer's disease and senile dementia Alzheimer type groups, but no significant difference was seen between the senile control group and multi-infarct dementia group. The correlation was 0.72 (p less than 0.004) between the mean CBF of the whole brain and the score of Hasegawa's Dementia Scale, and 0.94 (p less than 0.0001) between rCBF of the temporo-parietal region and the scale in Alzheimer's disease. In the senile dementia Alzheimer type group, the correlations were 0.77 (p less than 0.01) and 0.83 (p less than 0.004) respectively. No significant correlations were found in the multi-infarct dementia group. A temporo-parietal reduction in the distribution of the rCBF characteristic in the Alzheimer's disease group and a patchy whole brain reduction characteristic in the multi-infarct dementia group was detected. The ability of our improved SPECT to provide both quantitative measurement of rCBF and characteristic rCBF distribution patterns, makes it a promising tool for research or routine examination of demented patients.

  1. Cerebral blood flow and CO/sub 2/ reactivity in transient ischemic attacks: comparison between TIAs due to the ICA occlusion and ICA mild stenosis

    SciTech Connect

    Tsuda, Y.; Kimura, K.; Yoneda, S.; Etani, H.; Asai, T.; Nakamura, M.; Abe, H.

    1983-01-01

    Hemispheric mean cerebral blood flow (CBF), together with its CO2 reactivity in response to hyperventilation, was investigated in 18 patients with transient ischemic attacks (TIAs) by intraarterial 133Xe injection method in a subacute-chronic stage of the clinical course. In 8 patients, the lesion responsible for symptoms was regarded as unilateral internal carotid artery (ICA) occlusion, and in 10 patients, it was regarded as unilateral ICA mild stenosis (less than 50% stenosis in diameter). Resting flow values were significantly decreased in the affected hemisphere of TIA due to the ICA occlusion as compared with the unaffected hemisphere of the same patient, regarded as the relative control. It was not decreased in the affected hemisphere of TIA due to the ICA mild stenosis as compared with the control. With respect to the responsiveness of CBF to changes in PaCO2, it was preserved in both TIAs, due to the ICA occlusion and ICA mild stenosis. Vasoparalysis was not observed in either types of TIAs in the subacute-chronic stage. However, in the relationship of blood pressure and CO2 reactivity, expressed as delta CBF(%)/delta PaCO2, pressure-dependent CO2 reactivity as a group was observed with significance in 8 cases of TIA due to the ICA occlusion, while no such relationship was noted in 10 cases of TIA due to the ICA mild stenosis. Moreover, clinical features were different between TIAs due to the ICA occlusion and ICA mild stenosis, i.e., more typical, repeatable TIA (6.3 +/- 3.7 times) with shorter duration (less than 30 minutes) was observed in TIAs due to the ICA mild stenosis, while more prolonged, less repeatable TIA (2.4 +/- 1.4 times) was observed in TIAs due to fixed obstruction of the ICA. From these observations, two different possible mechanisms as to the pathogenesis of TIA might be expected.

  2. Evidence for a local sympathetic venoarteriolar ''reflex'' in the dog hindleg

    SciTech Connect

    Henriksen, O.; Amtorp, O.; Faris, I.; Agerskov, K.

    1983-05-01

    The study was performed in order to determine whether a local sympathetic venoarteriolar ''reflex'' is present in the dog hindleg. Femoral artery blood flow was measured by an electromagnetic flowmeter probe, and blood flow in the thigh muscle and subcutaneous tissue distally in the paw was measured by the local 133Xe washout technique. Twenty experiments were carried out in seven dogs unilaterally sympathectomized 2-4 weeks previously. Resting vascular tone did not differ in the sympathectomized and nonsympathectomized legs. In the control leg, venous pressure elevation caused a decrease in femoral blood flow of 49% corresponding to an increase in vascular resistance of 58%. In muscle and subcutaneous tissue vascular resistance increased by 81% and 35%, respectively. In the denervated leg, venous stasis caused no change in total vascular resistance. In muscle the vascular resistance increased by only 24%. In subcutaneous tissue, vascular resistance decreased by 12%. The effect of acute lumbar sympathectomy was studied in another group of seven dogs. Operation caused an immediate decrease in vascular resistance of 40%. The increase in vascular resistance during venous stasis in the total leg, as well as in muscle and subcutaneous tissue, was not affected. However, acute lumbar sympathectomy combined with injection of phenoxybenzamine into the femoral artery almost abolished the vasoconstriction induced by venous stasis. In muscle, the increase in vascular resistance was still present, but considerably attenuated. In subcutaneous tissue, the normal response was completely blocked. Finally, local suction induced vasoconstriction in an adjoining area not subjected to changes in vascular transmural pressure, an effect that could be blocked by local neural blockade at the site of suction. The results strongly suggest that a local sympathetic veno-arteriolar (axon) ''reflex'' is present in muscle and subcutaneous tissue in the dog hindleg.

  3. Sympathetic reflex control of skeletal muscle blood flow in patients with congestive heart failure: evidence for beta-adrenergic circulatory control

    SciTech Connect

    Kassis, E.; Jacobsen, T.N.; Mogensen, F.; Amtorp, O.

    1986-11-01

    Mechanisms controlling forearm muscle vascular resistance (FMVR) during postural changes were investigated in seven patients with severe congestive heart failure (CHF) and in seven control subjects with unimpaired left ventricular function. Relative brachioradial muscle blood flow was determined by the local /sup 133/Xe-washout technique. Unloading of baroreceptors with use of 45 degree upright tilt was comparably obtained in the patients with CHF and control subjects. Control subjects had substantially increased FMVR and heart rate to maintain arterial pressure whereas patients with CHF had decreased FMVR by 51 +/- 11% and had no increase in heart rate despite a fall in arterial pressure during upright tilt. The autoregulatory and local vasoconstrictor reflex responsiveness during postural changes in forearm vascular pressures were intact in both groups. In the patients with CHF, the left axillary nerve plexus was blocked by local anesthesia. No alterations in forearm vascular pressures were observed. This blockade preserved the local regulation of FMVR but reversed the vasodilator response to upright tilt as FMVR increased by 30 +/- 7% (p less than .02). Blockade of central neural impulses to this limb combined with brachial arterial infusions of phentolamine completely abolished the humoral vasoconstriction in the tilted position. Infusions of propranolol to the contralateral brachial artery that did not affect baseline values of heart rate, arterial pressure, or the local reflex regulation of FMVR reversed the abnormal vasodilator response to upright tilt as FMVR increased by 42 +/- 12% (p less than .02). Despite augmented baseline values, forearm venous but not arterial plasma levels of epinephrine increased in the tilted position, as did arteri rather than venous plasma concentrations of norepinephrine in these patients.

  4. Fission Product Monitoring and Release Data for the Advanced Gas Reactor -1 Experiment

    SciTech Connect

    Dawn M. Scates; John B. Walter; Jason M. Harp; Mark W. Drigert; Edward L. Reber

    2010-10-01

    The AGR-1 experiment is a fueled multiple-capsule irradiation experiment that was irradiated in the Advanced Test Reactor (ATR) from December 26, 2006 until November 6, 2009 in support of the Very High Temperature Reactor (VHTR) Technology Development Office (TDO) Fuel Development and Qualification program. An important measure of the fuel performance is the quantification of the fission product releases over the duration of the experiment. To provide this data for the inert fission gasses(Kr and Xe), a fission product monitoring system (FPMS) was developed and implemented to monitor the individual capsule effluents for the radioactive species. The FPMS continuously measured the concentrations of various krypton and xenon isotopes in the sweep gas from each AGR-1 capsule to provide an indicator of fuel irradiation performance. Spectrometer systems quantified the concentrations of Kr-85m, Kr-87, Kr-88, Kr-89, Kr-90, Xe-131m, Xe-133, Xe 135, Xe 135m, Xe-137, Xe-138, and Xe-139 accumulated over repeated eight hour counting intervals.-. To determine initial fuel quality and fuel performance, release activity for each isotope of interest was derived from FPMS measurements and paired with a calculation of the corresponding isotopic production or birthrate. The release activities and birthrates were combined to determine Release-to-Birth ratios for the selected nuclides. R/B values provide indicators of initial fuel quality and fuel performance during irradiation. This paper presents a brief summary of the FPMS, the release to birth ratio data for the AGR-1 experiment and preliminary comparisons of AGR-1 experimental fuels data to fission gas release models.

  5. Lactate release from the subcutaneous tissue in lean and obese men.

    PubMed Central

    Jansson, P A; Larsson, A; Smith, U; Lönnroth, P

    1994-01-01

    Lactate concentration in the subcutaneous interstitial fluid and adipose tissue blood flow (ATBF, ml/100 g.min) were simultaneously measured with the microdialysis technique combined with 133Xe clearance in the abdominal and femoral subcutaneous adipose tissue in nine lean and nine obese men. The studies were performed both in the postabsorptive state and 2 h after an oral glucose load and the results compared to the lactate levels in arterialized venous plasma. After an overnight's fast, arterial lactate was 738 +/- 49 and 894 +/- 69 microM (mean +/- SE) (P < 0.05) in the lean and obese subjects, respectively. The interstitial lactate levels were significantly higher than blood lactate in both subject groups without any regional differences. Abdominal and femoral ATBF was 3.2 +/- 0.6 vs. 2.8 +/- 0.4 and 1.7 +/- 0.3 vs. 2.4 +/- 0.4 ml/100 g.min (P < 0.05) in lean and obese subjects, respectively. Mean apparent lactate release from the abdominal vs. femoral adipose tissue in the fasting state was 10.5 +/- 3.1 vs. 8.6 +/- 2.3 and 6.0 +/- 2.3 vs. 8.5 +/- 2.3 mumol/kg.min (NS) in lean and obese subjects, respectively. Both plasma and interstitial lactate levels increased significantly after an oral glucose load in both subject groups. However, apparent lactate release increased significantly only in the lean group. It is concluded that subcutaneous adipose tissue is a significant source of whole-body lactate release in the postabsorptive state and that this is further enhanced in obese subjects due to their large adipose mass. PMID:8282793

  6. Influence of circulating epinephrine on absorption of subcutaneously injected insulin

    SciTech Connect

    Fernqvist, E.; Gunnarsson, R.; Linde, B.

    1988-06-01

    Effects of epinephrine (Epi) infusion on the absorption of subcutaneously injected 125I-labeled soluble human insulin (10 U) from the thigh or the abdomen were studied in 16 healthy subjects and from the thigh in 10 insulin-dependent diabetic (IDDM) patients. Epi was infused at 0.3 (high dose) or 0.1 (low dose; healthy subjects) nmol.kg-1.min-1 i.v., resulting in arterial plasma Epi levels of approximately 6 and 2 nM, respectively. Saline was infused on a control day. Insulin absorption was measured as disappearance of radioactivity from the injection site and as appearance of plasma immunoreactive insulin (IRI). Adipose tissue blood flow was measured with the 133Xe clearance technique. First-order disappearance rate constants of 125I from the thigh depot decreased approximately 40-50% during the high dose of Epi compared with control (P less than .001). The corresponding decrease from the abdominal depot was approximately 40% (P less than .001), whereas no significant change was found during the low Epi dose. IRI fell compared with control in all groups at the high Epi dose. The Epi-induced depression of insulin absorption occurred despite unaltered or even slightly increased subcutaneous blood flow. The results indicate that circulating Epi at levels seen during moderate physical stress depresses the absorption of soluble insulin from subcutaneous injection sites to an extent that might be important for glycemic control in IDDM patients. Furthermore, dissociation is found between changes in insulin absorption and subcutaneous blood flow during Epi infusion, suggesting that factors other than blood flow may also influence the absorption of subcutaneously injected insulin.

  7. [Clinical application of the central somatosensory conduction time (CCT)].

    PubMed

    Ueda, M; Matsumae, M; Sato, O; Suzuki, Y; Murase, H; Sakurai, I

    1987-09-01

    We tried to prove the usefulness of CCT as an index of cerebral functions. CCT, regional cerebral blood flow (CBF) and CT scan findings were studied in 213 neurological patients with CVD (66 cases), cerebral tumors (66 cases) and head traumas (81 cases). The technique of CCT recording was modified from that of Jones (1977) using CADWELL 5200 system. CCT was defined as the difference of the peak latency between N13 recorded at the C-7 vertebral electrode and N20 recorded at the somatosensory cortex. The control CCT in normal volunteers (N = 20) was 5.7 +/- 0.4 msec. RCBF was measured with 133 Xe intra carotid injection method of Lassen & Ingvar using gammacamera (DEC GAMM 11/34). CCT tended significantly to become more prolonged in affected hemisphere than in unaffected hemisphere of patients with three groups (CVD, tumor and trauma) (p less than 0.01). Forty percent reduction of control rCBF caused a prolongation of CCT over 7 msec. The degrees of CCT prolongations appeared to be proportional to the degree of rCBF diminution. Prolongation of CCT was remarkable in the side of low density area on CT scan. The prolongation of CCT were revealed in the patients before they did not manifest their neurological deficits especially in the disease of metastatic tumors and glioma. In the case of patients with trauma who we could follow to measure rCBF, CCT tended to become shorten as rCBF increased till normal range. CCT was not significantly prolonged in congenital hydrocephalus.(ABSTRACT TRUNCATED AT 250 WORDS)

  8. The workshop on signatures of medical and industrial isotope production - WOSMIP; Strassoldo, Italy, 1-3 July 2009.

    PubMed

    Matthews, K M; Bowyer, T W; Saey, P R J; Payne, R F

    2012-08-01

    Radiopharmaceuticals make contributions of inestimable value to medical practice. With growing demand new technologies are being developed and applied worldwide. Most diagnostic procedures rely on (99m)Tc and the use of uranium targets in reactors is currently the favored method of production, with 95% of the necessary (99)Mo parent currently being produced by four major global suppliers. Coincidentally there are growing concerns for nuclear security and proliferation. New disarmament treaties such as the Comprehensive Nuclear-Test-Ban Treaty (CTBT) are coming into effect and treaty compliance-verification monitoring is gaining momentum. Radioxenon emissions (isotopes Xe-131, 133, 133m and 135) from radiopharmaceutical production facilities are of concern in this context because radioxenon is a highly sensitive tracer for detecting nuclear explosions. There exists, therefore, a potential for confusing source attribution, with emissions from radiopharmaceutical-production facilities regularly being detected in treaty compliance-verification networks. The CTBT radioxenon network currently under installation is highly sensitive with detection limits approaching 0.1 mBq/m³ and, depending on transport conditions and background, able to detect industrial release signatures from sites thousands of kilometers away. The method currently employed to distinguish between industrial and military radioxenon sources involves plots of isotope ratios (133m)Xe/(131m)Xe versus (135)Xe/(133)Xe, but source attribution can be ambiguous. Through the WOSMIP Workshop the environmental monitoring community is gaining a better understanding of the complexities of the processes at production facilities, and the production community is recognizing the impact their operations have on monitoring systems and their goal of nuclear non-proliferation. Further collaboration and discussion are needed, together with advances in Xe trapping technology and monitoring systems. Such initiatives will help

  9. Gas exchange and intrapulmonary distribution of ventilation during continuous-flow ventilation

    SciTech Connect

    Vettermann, J.; Brusasco, V.; Rehder, K.

    1988-05-01

    In 12 anesthetized paralyzed dogs, pulmonary gas exchange and intrapulmonary inspired gas distribution were compared between continuous-flow ventilation (CFV) and conventional mechanical ventilation (CMV). Nine dogs were studied while they were lying supine, and three dogs were studied while they were lying prone. A single-lumen catheter for tracheal insufflation and a double-lumen catheter for bilateral endobronchial insufflation (inspired O2 fraction = 0.4; inspired minute ventilation = 1.7 +/- 0.3 (SD) 1.kg-1.min-1) were evaluated. Intrapulmonary gas distribution was assessed from regional 133Xe clearances. In dogs lying supine, CO2 elimination was more efficient with endobronchial insufflation than with tracheal insufflation, but the alveolar-arterial O2 partial pressure difference was larger during CFV than during CMV, regardless of the type of insufflation. By contrast, endobronchial insufflation maintained both arterial PCO2 and alveolar-arterial O2 partial pressure difference at significantly lower levels in dogs lying prone than in dogs lying supine. In dogs lying supine, the dependent lung was preferentially ventilated during CMV but not during CFV. In dogs lying prone, gas distribution was uniform with both modes of ventilation. The alveolar-arterial O2 partial pressure difference during CFV in dogs lying supine was negatively correlated with the reduced ventilation of the dependent lung, which suggests that increased ventilation-perfusion mismatching was responsible for the increase in alveolar-arterial O2 partial pressure difference. The more efficient oxygenation during CFV in dogs lying prone suggests a more efficient matching of ventilation to perfusion, presumably because the distribution of blood flow is also nearly uniform.

  10. Depth discrimination in acousto-optic cerebral blood flow measurement simulation

    NASA Astrophysics Data System (ADS)

    Tsalach, A.; Schiffer, Z.; Ratner, E.; Breskin, I.; Zeitak, R.; Shechter, R.; Balberg, M.

    2016-03-01

    Monitoring cerebral blood flow (CBF) is crucial, as inadequate perfusion, even for relatively short periods of time, may lead to brain damage or even death. Thus, significant research efforts are directed at developing reliable monitoring tools that will enable continuous, bed side, simple and cost-effective monitoring of CBF. All existing non invasive bed side monitoring methods, which are mostly NIRS based, such as Laser Doppler or DCS, tend to underestimate CBF in adults, due to the indefinite effect of extra-cerebral tissues on the obtained signal. If those are to find place in day to day clinical practice, the contribution of extra-cerebral tissues must be eliminated and data from the depth (brain) should be extracted and discriminated. Recently, a novel technique, based on ultrasound modulation of light was developed for non-invasive, continuous CBF monitoring (termed ultrasound-tagged light (UTL or UT-NIRS)), and shown to correlate with readings of 133Xe SPECT and laser Doppler. We have assembled a comprehensive computerized simulation, modeling this acousto-optic technique in a highly scattering media. Using the combination of light and ultrasound, we show how depth information may be extracted, thus distinguishing between flow patterns taking place at different depths. Our algorithm, based on the analysis of light modulated by ultrasound, is presented and examined in a computerized simulation. Distinct depth discrimination ability is presented, suggesting that using such method one can effectively nullify the extra-cerebral tissues influence on the obtained signals, and specifically extract cerebral flow data.

  11. International challenge to predict the impact of radioxenon releases from medical isotope production on a comprehensive nuclear test ban treaty sampling station.

    PubMed

    Eslinger, Paul W; Bowyer, Ted W; Achim, Pascal; Chai, Tianfeng; Deconninck, Benoit; Freeman, Katie; Generoso, Sylvia; Hayes, Philip; Heidmann, Verena; Hoffman, Ian; Kijima, Yuichi; Krysta, Monika; Malo, Alain; Maurer, Christian; Ngan, Fantine; Robins, Peter; Ross, J Ole; Saunier, Olivier; Schlosser, Clemens; Schöppner, Michael; Schrom, Brian T; Seibert, Petra; Stein, Ariel F; Ungar, Kurt; Yi, Jing

    2016-06-01

    The International Monitoring System (IMS) is part of the verification regime for the Comprehensive Nuclear-Test-Ban-Treaty Organization (CTBTO). At entry-into-force, half of the 80 radionuclide stations will be able to measure concentrations of several radioactive xenon isotopes produced in nuclear explosions, and then the full network may be populated with xenon monitoring afterward. An understanding of natural and man-made radionuclide backgrounds can be used in accordance with the provisions of the treaty (such as event screening criteria in Annex 2 to the Protocol of the Treaty) for the effective implementation of the verification regime. Fission-based production of (99)Mo for medical purposes also generates nuisance radioxenon isotopes that are usually vented to the atmosphere. One of the ways to account for the effect emissions from medical isotope production has on radionuclide samples from the IMS is to use stack monitoring data, if they are available, and atmospheric transport modeling. Recently, individuals from seven nations participated in a challenge exercise that used atmospheric transport modeling to predict the time-history of (133)Xe concentration measurements at the IMS radionuclide station in Germany using stack monitoring data from a medical isotope production facility in Belgium. Participants received only stack monitoring data and used the atmospheric transport model and meteorological data of their choice. Some of the models predicted the highest measured concentrations quite well. A model comparison rank and ensemble analysis suggests that combining multiple models may provide more accurate predicted concentrations than any single model. None of the submissions based only on the stack monitoring data predicted the small measured concentrations very well. Modeling of sources by other nuclear facilities with smaller releases than medical isotope production facilities may be important in understanding how to discriminate those releases from

  12. Regulation of local subcutaneous blood flow in patients with psoriasis and effects of antipsoriatic treatment on subcutaneous blood flow

    SciTech Connect

    Klemp, P.

    1985-08-01

    Local regulation of the doubled subcutaneous blood flow (SBF) rates in psoriatic lesional skin was studied in 8 patients using a traumatic epicutaneous /sup 133/Xe labeling washout technique. Venous stasis of 40 mm Hg induced a significant reduction in the SBF (-34%, p less than 0.01), i.e., a normal vasoconstrictor response. Limb elevation of 40 cm above heart level induced no statistical changes in the SBF (p = 0.50), i.e., a normal local autoregulation response. This indicates normal, local regulation mechanisms of SBF in psoriasis. In another 8 patients, the effect on SBF of a 4-week antipsoriatic treatment with tar was studied in lesional and symmetrically nonlesional skin areas. One patient was clear of psoriasis on day 22, and was followed only to that time. The mean pretreatment SBF in lesional skin areas was 3.87 +/- SD 0.78 ml X (100 g X min)-1, which was not statistically different from measurements on days 3, 7, 14, and 21 after treatment had started. Between day 21 and day 28, the SBF decreased significantly to 3.38 +/- SD 0.78 ml X (100 g X min)-1, p less than 0.05. The difference between the pretreatment SBF and SBF at the end of treatment was statistically significant, p less than 0.05. The changes in SBF in symmetrically nonlesional skin areas were statistically nonsignificant during the period of treatment. Pretreatment SBF was 2.60 +/- SD 1.08 (N = 8), and on day 28 was 1.91 +/- SD 0.74 ml X (100 g X min)-1 (N = 7). However, the tendency of a decreasing SBF at the end of treatment was a clear trend, since SBF in 6 of 7 patients decreased during the third week and in the patient who was discharged on day 22, a decrease in the SBF was observed on days 14 and 21.

  13. Diabetic patients have abnormal cerebral autoregulation during cardiopulmonary bypass

    SciTech Connect

    Croughwell, N.; Lyth, M.; Quill, T.J.; Newman, M.; Greeley, W.J.; Smith, L.R.; Reves, J.G. )

    1990-11-01

    We tested the hypothesis that insulin-dependent diabetic patients with coronary artery bypass graft surgery experience altered coupling of cerebral blood flow and oxygen consumption. In a study of 23 patients (11 diabetics and 12 age-matched controls), cerebral blood flow was measured using 133Xe clearance during nonpulsatile, alpha-stat blood gas managed cardiopulmonary bypass at the conditions of hypothermia and normothermia. In diabetic patients, the cerebral blood flow at 26.6 +/- 2.42 degrees C was 25.3 +/- 14.34 ml/100 g/min and at 36.9 +/- 0.58 degrees C it was 27.3 +/- 7.40 ml/100 g/min (p = NS). The control patients increased cerebral blood flow from 20.7 +/- 6.78 ml/100 g/min at 28.4 +/- 2.81 degrees C to 37.6 +/- 8.81 ml/100 g/min at 36.5 +/- 0.45 degrees C (p less than or equal to 0.005). The oxygen consumption was calculated from jugular bulb effluent and increased from hypothermic values of 0.52 +/- 0.20 ml/100 g/min in diabetics to 1.26 +/- 0.28 ml/100 g/min (p = 0.001) at normothermia and rose from 0.60 +/- 0.27 to 1.49 +/- 0.35 ml/100 g/min (p = 0.0005) in the controls. Thus, despite temperature-mediated changes in oxygen consumption, diabetic patients did not increase cerebral blood flow as metabolism increased. Arteriovenous oxygen saturation gradients and oxygen extraction across the brain were calculated from arterial and jugular bulb blood samples. The increase in arteriovenous oxygen difference between temperature conditions in diabetic patients and controls was significantly different (p = 0.01). These data reveal that diabetic patients lose cerebral autoregulation during cardiopulmonary bypass and compensate for an imbalance in adequate oxygen delivery by increasing oxygen extraction.

  14. Solubility of xenon in amino-acid solutions. II. Nine less-soluble amino acids

    NASA Astrophysics Data System (ADS)

    Kennan, Richard P.; Himm, Jeffrey F.; Pollack, Gerald L.

    1988-05-01

    Ostwald solubility (L) of xenon gas, as the radioisotope 133Xe, has been measured as a function of solute concentration, at 25.0 °C, in aqueous solutions of nine amino acids. The amino-acid concentrations investigated covered much of their solubility ranges in water, viz., asparagine monohydrate (0-0.19 M), cysteine (0-1.16 M), glutamine (0-0.22 M), histidine (0-0.26 M), isoleucine (0-0.19 M), methionine (0-0.22 M), serine (0-0.38 M), threonine (0-1.4 M), and valine (0-0.34 M). We have previously reported solubility results for aqueous solutions of six other, generally more soluble, amino acids (alanine, arginine, glycine, hydroxyproline, lysine, and proline), of sucrose and sodium chloride. In general, L decreases approximately linearly with increasing solute concentration in these solutions. If we postulate that the observed decreases in gas solubility are due to hydration, the results under some assumptions can be used to calculate hydration numbers (H), i.e., the number of H2O molecules associated with each amino-acid solute molecule. The average values of hydration number (H¯) obtained at 25.0 °C are 15.3±1.5 for asparagine, 6.8±0.3 for cysteine, 11.5±1.1 for glutamine, 7.3±0.7 for histidine, 5.9±0.4 for isoleucine, 10.6±0.8 for methionine, 11.2±1.3 for serine, 7.7± 1.0 for threonine, and 6.6±0.6 for valine. We have also measured the temperature dependence of solubility L(T) from 5-40 °C for arginine, glycine, and proline, and obtained hydration numbers H¯(T) in this range. Between 25-40 °C, arginine has an H¯ near zero. This may be evidence for an attractive interaction between xenon and arginine molecules in aqueous solution.

  15. Testicular blood flow and a study of the testicular venous to arterial transfer of radioactive krypton and testosterone in the rhesus monkey

    PubMed Central

    Einer-Jensen, N.; Waites, G. M. H.

    1977-01-01

    1. Testicular blood flow (ml. 100 g-1.min-1; mean ± S.E. of the mean) measured in monkeys by 133Xe clearance was 15·9 ± 1·2 (twenty-six estimations on three monkeys; six testes) within 15 min of anaesthesia and 7·5 ± 0·8 (twelve estimates; four monkeys, eight testes), after 1-2 hr of anaesthesia; and, when measured by 85Kr clearance in the second hour of anaesthesia was 9·1 ± 3·7 (seven estimates; four monkeys, four testes). Testicular temperature was 32·9 ± 0·2° C (mean ± S.E. of mean) when deep body temperature was 37·2 ± 0·2° C. 2. Blood flow in the caput epididymidis was 27·4 ± 2·1 ml. 100 g-1.min-1 (mean ± S.E. of mean; four estimates). 3. Radioactivity accumulated in the ipsilateral testis and epididymis but not in the contralateral tissues, during the infusion of 85Kr saline into the testicular veins. 4. During [3H]testosterone infusions into the testicular veins, radioactivity was consistently higher in ipsilateral testicular arterial plasma than in plasma withdrawn simultaneously from the aorta in four of five experiments with no difference in one. After two such infusions, the radioactivity was up to 5 times greater in the ipsilateral testis and epididymis than in the contralateral tissues. 5. During one infusion of [125I]bovine serum albumin into the testicular veins, there was no accumulation of radioactivity in the ipsilateral tissues. 6. Testosterone concentrations (ng.ml-1; mean ± S.E. of mean) in plasma from seven anaesthetized monkeys which were sexually experienced were: testicular vein 53·22 ± 8·03 (eight estimates); testicular artery, 4·58 ± 0·94 (14); saphenous vein, 3·81 ± 0·68 (14). The corresponding values from four sexually inexperienced monkeys were 25·27 ± 2·11 (12); 2·89 ± 1·99 (12); aorta 2·76 ± 0·57 (12). 7. The results are discussed as evidence for vascular exchange of molecules between the testicular veins and artery in the spermatic cord. PMID:874824

  16. An inverse modeling method to assess the source term of the Fukushima nuclear power plant accident using gamma dose rate observations

    NASA Astrophysics Data System (ADS)

    Saunier, O.; Mathieu, A.; Didier, D.; Tombette, M.; Quélo, D.; Winiarek, V.; Bocquet, M.

    2013-06-01

    The Chernobyl nuclear accident and more recently the Fukushima accident highlighted that the largest source of error on consequences assessment is the source term including the time evolution of the release rate and its distribution between radioisotopes. Inverse modeling methods, which combine environmental measurements and atmospheric dispersion models, have proven efficient in assessing source term due to an accidental situation (Gudiksen, 1989; Krysta and Bocquet, 2007; Stohl et al., 2012a; Winiarek et al., 2012). Most existing approaches are designed to use air sampling measurements (Winiarek et al., 2012) and some of them also use deposition measurements (Stohl et al., 2012a; Winiarek et al., 2013) but none of them uses dose rate measurements. However, it is the most widespread measurement system, and in the event of a nuclear accident, these data constitute the main source of measurements of the plume and radioactive fallout during releases. This paper proposes a method to use dose rate measurements as part of an inverse modeling approach to assess source terms. The method is proven efficient and reliable when applied to the accident at the Fukushima Daiichi nuclear power plant (FD-NPP). The emissions for the eight main isotopes 133Xe, 134Cs, 136Cs, 137Cs, 137mBa, 131I, 132I and 132Te have been assessed. Accordingly, 103 PBq of 131I, 35.5 PBq of 132I, 15.5 PBq of 137Cs and 12 100 PBq of noble gases were released. The events at FD-NPP (such as venting, explosions, etc.) known to have caused atmospheric releases are well identified in the retrieved source term. The estimated source term is validated by comparing simulations of atmospheric dispersion and deposition with environmental observations. The result is that the model-measurement agreement for all of the monitoring locations is correct for 80% of simulated dose rates that are within a factor of 2 of the observed values. Changes in dose rates over time have been overall properly reconstructed, especially

  17. How to tackle wet-deposition of radionuclides in the context of RN threshold-monitoring for CTBT verification?

    NASA Astrophysics Data System (ADS)

    Becker, A.; Ceranna, L.; Ross, O.; Schneider, U.; Meyer-Christoffer, A.; Ziese, M.; Rudolf, B.

    2011-12-01

    . Becker, 2010: High-Resolution Precipitation Dataset, WMO/IOC/UNEP/ICSU GCOS, GCOS/WCRP AOPC-XVI, Geneva, Switzerland, 7 - 11 FEBRUARY 2011, Doc 12.1-V.1 Wotawa, G., Becker, A., et al. 2009: Computation and analysis of the global distribution of the Radioxenon Isotope 133Xe based on emissions from nuclear power plants and isotope production facilities and its relevance for the verification of the Nuclear-Test-Ban Treaty. Pure and Applied Geophysics Topical Volume 167 (4-5), 541-557

  18. Examining Changes in Radioxenon Isotope Activity Ratios during Subsurface Transport

    NASA Astrophysics Data System (ADS)

    Annewandter, Robert

    2014-05-01

    volume method. The parabolic and hyperbolic problem can be solved separately by operator-splitting. The resulting system of linear equations is solved by the algebraic multigrid library SAMG, developed at the Fraunhofer Institute for Algorithms and Scientific Computing, Germany. CSMP++ is developed at Montan University of Leoben, ETH Zuerich, Imperial College London and Heriot-Watt University in Edinburgh. This study examines barometric pumping-driven subsurface transport of Xe-135, Xe-133m, Xe-133, Xe-131m including I-131, I-133 and I-135 on arrival times and isotopic activity ratios. This work was funded by the CTBTO Research Award for Young Scientist and Engineers (2013).

  19. Improved scheme for parametrization of convection in the Met Office's Numerical Atmospheric-dispersion Modelling Environment (NAME)

    NASA Astrophysics Data System (ADS)

    Meneguz, Elena; Thomson, David; Witham, Claire; Kusmierczyk-Michulec, Jolanta

    2015-04-01

    the isotope 133Xe available at International Monitoring System stations around the South Pacific Ocean. In addition, timeseries of modelled output concentrations obtained using NAME on a grid of 25 km size are compared with those obtained with FLEXPART, another well-known atmospheric dispersion model used by the Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO) and other scientific communities. Findings are discussed and discrepancies investigated.

  20. Examining Changes in Radioxenon Isotope Activity Ratios during Subsurface Transport

    NASA Astrophysics Data System (ADS)

    Annewandter, R.

    2013-12-01

    differential equations by a complementary finite volume method. The parabolic and hyperbolic problem can be solved separately using the operator-splitting method (Implicit Pressure Explicit Saturation, IMPES). The resulting system of linear equations is solved by the algebraic multigrid library SAMG, developed at the Fraunhofer Institute for Algorithms and Scientific Computing. CSMP++ is developed at Montan University of Leoben, ETH Zuerich, Imperial College London and Heriot-Watt University in Edinburgh. To date, there has been no research investigating how subsurface transport impacts isotope activity ratios. The isotopic activity ratio method can be used to discriminate between civil release or nuclear explosion sources. This study examines possible fractionation of Xe-135, Xe-133m, Xe-133, Xe-131m during barometric pumping-driven subsurface migration, which can affect surface arrival times and isotopic activity ratios. Surface arrival times for the Noble gases Kr-81, Kr-85 and Ar-39 are also calculated.

  1. Evaluation of Observed and Modelled Aerosol Lifetimes Using Radioactive Tracers of Opportunity and an Ensemble of 19 Global Models

    NASA Technical Reports Server (NTRS)

    Kristiansen, N. I.; Stohl, A.; Olivie, D. J. L.; Croft, B.; Sovde, O. A.; Klein, H.; Christoudias, T.; Kunkel, D.; Leadbetter, S. J.; Lee, Y. H.; Zhang, K.; Tsigaridis, K.; Bauer, S. E.; Faluvegi, G. S.; Shindell, D.

    2016-01-01

    Aerosols have important impacts on air quality and climate, but the processes affecting their removal from the atmosphere are not fully understood and are poorly constrained by observations. This makes modelled aerosol lifetimes uncertain. In this study, we make use of an observational constraint on aerosol lifetimes provided by radionuclide measurements and investigate the causes of differences within a set of global models. During the Fukushima Dai-Ichi nuclear power plant accident of March 2011, the radioactive isotopes cesium-137 (Cs-137) and xenon-133 (Xe-133) were released in large quantities. Cesium attached to particles in the ambient air, approximately according to their available aerosol surface area. Cs-137 size distribution measurements taken close to the power plant suggested that accumulation mode (AM) sulfate aerosols were the main carriers of cesium. Hence, Cs-137 can be used as a proxy tracer for the AM sulfate aerosol's fate in the atmosphere. In contrast, the noble gas Xe-133 behaves almost like a passive transport tracer. Global surface measurements of the two radioactive isotopes taken over several months after the release allow the derivation of a lifetime of the carrier aerosol. We compare this to the lifetimes simulated by 19 different atmospheric transport models initialized with identical emissions of Cs-137that were assigned to an aerosol tracer with each model's default properties of AM sulfate, and Xe-133 emissions that were assigned to a passive tracer. We investigate to what extent the modelled sulfate tracer can reproduce the measurements, especially with respect to the observed loss of aerosol mass with time. Modelled Cs-137and Xe-133 concentrations sampled at the same location and times as station measurements allow a direct comparison between measured and modelled aerosol lifetime. The e-folding lifetime e, calculated from station measurement data taken between 2 and 9 weeks after the start of the emissions, is 14.3 days (95

  2. Atmospheric lifetime of caesium-137 as an estimate of aerosol lifetime -quantified from global measurements in the months after the Fukushima Dai-ichi nuclear accident

    NASA Astrophysics Data System (ADS)

    Iren Kristiansen, Nina; Stohl, Andreas; Wotawa, Gerhard

    2013-04-01

    Radionuclides like caesium-137 (137Cs) can be emitted to the atmosphere in great quantities during nuclear accidents and are of significant health impact. A global set of radionuclide measurements collected over several months after the accidental release from the Fukushima Dai-ichi nuclear power plant in March 2011 has been used to estimate the atmospheric lifetime of 137Cs. Lifetime is here defined as the e-folding time scale (the time interval in which the exponential decay of the 137Cs quantity has decreased by factor of e). The estimated atmospheric lifetime of 137Cs can also be used as an estimate of the lifetime of aerosols in the atmosphere. This is based on the fact that 137Cs attaches to the ambient accumulation-mode (AM) aerosols and trace their fate in the atmosphere. The 137Cs "tags" the AM aerosols and both the 137Cs and AM aerosols are removed simultaneously from the atmosphere by scavenging within clouds, precipitation and dry deposition. The 137Cs emitted from Fukushima attached mainly to sulphate aerosols in the size range 0.1-2 μm diameter. Measured 137Cs activity concentrations from several stations spread mostly over the Northern Hemisphere were evaluated, and the decrease in activity concentrations over time (after correction for radioactive decay) reflects the removal of aerosols by wet and dry deposition. Corrections for air mass transport were made using measurements of the noble gas xenon-133 (133Xe) which was also released during the accident. This noble gas does not attach to the aerosols and was thus used as a passive tracer of air mass transport. The atmospheric lifetime of 137Cs was estimated to 10.0-13.9 days during April and May 2011. This represents the atmospheric lifetime of a "background" AM aerosol well mixed in the extratropical northern hemisphere troposphere. It is expected that the lifetime of this vertically mixed background aerosol is longer than the lifetime of fresh AM aerosols directly emitted from surface sources

  3. An inverse modeling method to assess the source term of the Fukushima Nuclear Power Plant accident using gamma dose rate observations

    NASA Astrophysics Data System (ADS)

    Saunier, O.; Mathieu, A.; Didier, D.; Tombette, M.; Quélo, D.; Winiarek, V.; Bocquet, M.

    2013-11-01

    The Chernobyl nuclear accident, and more recently the Fukushima accident, highlighted that the largest source of error on consequences assessment is the source term, including the time evolution of the release rate and its distribution between radioisotopes. Inverse modeling methods, which combine environmental measurements and atmospheric dispersion models, have proven efficient in assessing source term due to an accidental situation (Gudiksen, 1989; Krysta and Bocquet, 2007; Stohl et al., 2012a; Winiarek et al., 2012). Most existing approaches are designed to use air sampling measurements (Winiarek et al., 2012) and some of them also use deposition measurements (Stohl et al., 2012a; Winiarek et al., 2014). Some studies have been performed to use dose rate measurements (Duranova et al., 1999; Astrup et al., 2004; Drews et al., 2004; Tsiouri et al., 2012) but none of the developed methods were carried out to assess the complex source term of a real accident situation like the Fukushima accident. However, dose rate measurements are generated by the most widespread measurement system, and in the event of a nuclear accident, these data constitute the main source of measurements of the plume and radioactive fallout during releases. This paper proposes a method to use dose rate measurements as part of an inverse modeling approach to assess source terms. The method is proven efficient and reliable when applied to the accident at the Fukushima Daiichi Nuclear Power Plant (FD-NPP). The emissions for the eight main isotopes 133Xe, 134Cs, 136Cs, 137Cs, 137mBa, 131I, 132I and 132Te have been assessed. Accordingly, 105.9 PBq of 131I, 35.8 PBq of 132I, 15.5 PBq of 137Cs and 12 134 PBq of noble gases were released. The events at FD-NPP (such as venting, explosions, etc.) known to have caused atmospheric releases are well identified in the retrieved source term. The estimated source term is validated by comparing simulations of atmospheric dispersion and deposition with

  4. Variation in airborne 137Cs peak levels with altitude from high-altitude locations across Europe after the arrival of Fukushima-labeled air masses

    NASA Astrophysics Data System (ADS)

    Masson, Olivier; Bieringer, Jacqueline; Dalheimer, Axel; Estier, Sybille; Evrard, Olivier; Penev, Ilia; Ringer, Wolfgang; Schlosser, Clemens; Steinkopff, Thomas; Tositti, Laura; de Vismes-Ott, Anne

    2015-04-01

    level were transported until Europe at rather high altitudes. This is consistent with 137Cs activity levels and 133Xe observations performed at the tropopause level thanks to aircraft samples over Germany and Switzerland (Estier and Steinmann). This also validates dispersion model computation according to which the Fukushima-labeled air masses were transported to Europe above 5500 m a.s.l. Conclusions : High altitude locations are on 'sentry duty' for radioactive monitoring and cross-border spreading of a contaminated plume. In this sense they can provide useful information on the vertical spreading of radionuclides, reveal arrival times over a given region and make it possible to explain ground deposition levels as a result of interactions of cloud droplets or rain drops with aerosols at high altitude. Beside non-homogeneities encountered on the European scale at lowland locations, this study shows that 137Cs peak activity levels regularly decreased between about 3500 m and less than 1000 m a.s.l. In addition field measurements confirm that air masses travelled at high altitude and that the 137Cs peaks were due to air masses coming from high tropospheric levels. This study also highlights the need to reinforce high-altitude aerosol sampling during emergency situations. This will make it possible to specify the dispersion conditions for modeling purposes and help explaining simulation and observation discrepancies.

  5. Differential effects of angiostatic steroids and dexamethasone on angiogenesis and cytokine levels in rat sponge implants.

    PubMed Central

    Hori, Y.; Hu, D. E.; Yasui, K.; Smither, R. L.; Gresham, G. A.; Fan, T. P.

    1996-01-01

    1. Subcutaneous implantation of sterile polyether sponges elicited a reproducible neovascular response in rats, as determined by blood flow measurement with a 133Xe clearance technique and confirmed histologically. This model was used to monitor the levels of two cytokines during angiogenesis and to compare the activities of angiostatic steroids and anti-inflammatory steroids. 2. Initial experiments followed the neovascular development over a 20-day period. Daily local injection of hydrocortisone caused a dose-dependent (0.5, 5 and 50 micrograms per sponge) inhibition of the basal sponge-induced angiogenesis. However, daily systemic treatment of hydrocortisone (2, 10 and 50 mg kg-1, s.c.) was less effective at inhibiting angiogenesis, and this inhibition was not sustained by day 20 after sponge implantation. 3. To investigate the involvement of cytokines during the course of angiogenesis, we measured the endogenous levels of tumour necrosis factor-alpha (TNF-alpha) and interleukin 6 (IL-6) in sponge implants. Levels of IL-6 and TNF-alpha peaked at day 7 and day 11 after implantation, respectively. These cytokine levels subsided through the completion of angiogenesis by day 20. 4. Subsequent experiments were carried out over a 14-day period. Among the three angiostatic steroids tested, U-24067 (6 alpha-fluoro-17,21 - dihydroxy-16 alpha-methylpregna -4,9(11)-diene-3,20-dione-21-acetate) showed a dose-dependent inhibition (0.5, 5 and 50 micrograms per sponge per day) of sponge-induced angiogenesis. Tetrahydro-S was also effective at 5 micrograms doses, but medroxyprogesterone failed to affect the angiogenic response. None of these steroids caused atrophies of the spleen and thymus. 5. Daily local injection of dexamethasone (0.5 microgram per sponge) inhibited the basal sponge-induced angiogenesis almost completely. Although higher doses of dexamethasone (5 and 50 micrograms per sponge) did not produce further inhibition of angiogenesis, they caused severe spleen and