Science.gov

Sample records for 131mxe 133mxe 133xe

  1. 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.

  2. 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. PMID:7107291

  3. Measurement of both left ventricular function and regional myocardial perfusion with 133Xe in dogs.

    PubMed

    Ruddy, T D; Yasuda, T; Barlai-Kovach, M; Nedelman, M A; Moore, R H; Alpert, N M; Correia, J A; Newell, J B; Okada, R D; Boucher, C A

    1987-01-01

    A technique to measure left ventricular (LV) function and myocardial perfusion was validated in 12 dogs. 133Xe in saline was injected into the left atrium (LA) or LV and two data sets were obtained using gamma camera imaging: 1) A first pass gated scan for LV function; followed by 2) Sequential images for regional myocardial perfusion. LV ejection fraction and wall motion measurements from the 133Xe blood pool images were compared to ejection fraction (r = 0.88, P less than 0.01) and wall motion (r = 0.83, P less than 0.01) data from 99mTc labeled blood pool scans. The perfusion measurements obtained with the 133Xe method were compared to microsphere data (r = 0.79, P less than 0.01). Measurements after LV 133Xe injection were similar to data following LA injection. Thus, quantitative assessment of global LV function, regional wall motion and myocardial perfusion is possible with LA or LV 133Xe injection and gamma camera imaging. PMID:3569342

  4. Monoexponential analysis of /sup 133/Xe clearance curves for regional cerebral blood flow measurements

    SciTech Connect

    Ryding, E.

    1984-06-01

    The theoretical properties of a monoexponential flow index, analogous to the one used earlier by other investigators for regional CBF (rCBF) measured after intraarterial injection, were investigated after the administration of /sup 133/Xe intraarterially, intravenously, and by inhalation under high and low flow conditions. The sensitivity of the flow index to changes in fast flow components or changes in the weight ratio between the fast and the slow flow compartments was found to be dependent on whichever part of the /sup 133/Xe clearance curve was used for the flow calculation and on the shape of the input function for /sup 133/Xe. Since biexponential analysis of the clearance curves includes a monoexponential approximation for each of the two components of the clearance curve corresponding to the high and the low flow ''families'' in the brain, the limitations of the monoexponential flow index observed are in principle also valid for the results of biexponential analysis of the clearance curves.

  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. 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.

  7. 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.

  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. PMID:24607612

  9. 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.

  10. Effect of Anti-inflammatory Drug Therapy on Clearance of 133Xe from Knee Joints of Patients with Rheumatoid Arthritis

    PubMed Central

    Dick, C.; Dick, P. H.; Nuki, G.; Whaley, K.; Boyle, J. A.; Shenkin, A.; Downie, W. W.; Buchanan, W. W.

    1969-01-01

    The degree of joint inflammation in 13 patients with rheumatoid arthritis, as measured by clinical indices, was reduced by both sodium salicylate and indomethacin. The clearance rate of 133Xe was reduced by indomethacin alone, and showed no correlation with the clinical features. PMID:4895341

  11. 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.

  12. 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.

  13. 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.

  14. 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

  15. Some experimental errors in calculating regional cerebral blood flow from the intracarotid 133Xe clearance curve. A quantitative evaluation employing a digital model.

    PubMed

    Kanno, I; Uemura, K

    1975-01-01

    A digital model study has been developed for quantitative assessment of experimental errors in the analysis of 133Xe clearance curve from the brain. A small computer synthesized a model of the clearance curve, varying combinations of fast and slow components. The curves were convoluted with Poisson random digits to simulate statistical fluctuations. Identical curves were overlapped with varying intervals to study the influence of remaining activity. The height over area method to ten minutes was confirmed to overestimate CBF by 10% to 15% with a slow component of 20 ml/100 gm per minute, and the overstimation was increased with a lower slow flow component. The initial slope value was shown to have a close relationship with the fast flow component when the latter was less than 100 ml/100 gm per minute. Errors due to statistical fluctuations were determined only by the initial height (Ho cps), as the percent standard deviation was deltaHo/Ho in the height over area method and 2 deltaHo/HologHo in the initial slope method, where deltaHo equals square rootHo. Remaining activity caused errors of 1% to 3% in the initial slope method with an injection interval of 15 minutes. The influence of remaining activity can be eliminated with an injection interval of more than 25 to 30 minutes in the initial slope method and more than 40 minutes in the height over area method. PMID:1154473

  16. 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.

  17. KINETICS OF INGESTED (222)RN IN HUMANS DETERMINED FROM MEASUREMENTS WITH (133)XE

    EPA Science Inventory

    The problem of naturally occurring 222-radon contamination has received a great deal of public and scientific attention over the past several years, and has become a major public health issue worldwide. The purpose of the work reported in the document was to provide information a...

  18. Abnormal cerebral vasodilation in aneurysmal subarachnoid hemorrhage: use of serial 133Xe cerebral blood flow measurement plus acetazolamide to assess cerebral vasospasm.

    PubMed

    Tran Dinh, Y R; Lot, G; Benrabah, R; Baroudy, O; Cophignon, J; Seylaz, J

    1993-10-01

    A patient with cerebral vasospasm following subarachnoid hemorrhage (SAH) was investigated by serial measurement of cerebral blood flow (CBF) using the xenon-133 emission tomography method. The CBF was measured before and after acetazolamide injection. On Day 2 after SAH, there was early local hyperperfusion in the middle cerebral artery (MCA) territory, ipsilateral to the left posterior communicating artery aneurysm. The regional CBF of this arterial territory decreased slightly after acetazolamide injection, probably because of vasoplegia and the "steal" phenomenon, and thus surgery was delayed. A right hemiplegia with aphasia and disturbed consciousness occurred 4 days later (on Day 6 after SAH) due to arterial vasospasm, despite treatment with a calcium-channel blocker. The initial hyperemia of the left MCA territory was followed by ischemia. The vasodilation induced by acetazolamide administration was significantly subnormal until Day 13, at which time CBF and vasoreactivity amplitude returned to normal and the patient's clinical condition improved. Surgery on Day 14 and outcome were without complication. It is concluded that serial CBF measurements plus acetazolamide injection are useful for monitoring the development of cerebral vasospasm to determine the most appropriate time for aneurysm surgery. PMID:8410215

  19. Gastrointestinal visualization during xenon-133 ventilation study in a patient with tracheoesophageal fistula

    SciTech Connect

    Takehara, Y.; Takahashi, M.; Isoda, H.; Niwa, H.; Mizuno, T.; Kaneko, M.

    1989-02-01

    A 37-yr-old female with H-type tracheoesophageal fistula demonstrated visualization of the gastrointestinal tract during a ventilation study using 133Xe gas. Gastrointestinal visualization by /sup 133/Xe on a ventilation study may prove to be a useful screening procedure for this condition in appropriate patients.

  20. 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.

  1. Radioxenon monitoring in Beijing following the Fukushima Daiichi NPP accident.

    PubMed

    Shilian, Wang; Qi, Li; Qinghua, Meng; Zhanying, Chen; Yungang, Zhao; Huijuan, Li; Huaimao, Jia; Yinzhong, Chang; Shujiang, Liu; Xinjun, Zhang; Yuanqing, Fan; Ling, Wan; Yun, Lou

    2013-11-01

    This paper reports the brief process and results of radioxenon monitoring and analysis in Beijing following the Fukushima Daiichi nuclear power plant accident. The accident and release of volatile radionuclides were caused by 9.0 magnitude earthquake and tsunami on March 11, 2011. The maximum concentrations of (133)Xe and (131 m)Xe were in excess of 0.90 Bq.m(-3) and 0.047 Bq.m(-3), respectively. The activity ratio of (131 m)Xe to (133)Xe and the dynamic trend of (133)Xe activity concentration were analyzed. PMID:23601858

  2. 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. PMID:24211671

  3. 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.

  4. Comparison of external lung monitoring with end-tidal air detection using the xenon-133 inhalation method

    SciTech Connect

    Hazelrig, J.B.; Halsey, J.H. Jr.; Wilson, E.M.; Wills, E.L.

    1985-11-01

    When the 133Xe inhalation method is employed for measuring regional cerebral blood flow, the arterial 133Xe concentration is usually approximated by the end-tidal air concentration. However, this approximation may be invalid in the presence of certain lung pathologies or when the breathing pattern is irregular. Jaggi and Obrist, using an intravenous injection of 133Xe, suggested that the counts detected by an external lung probe could provide an alternative estimate for arterial blood concentration once the noise produced by 133Xe in superficial tissues is removed from the signal. A mathematical model, based on hypotheses similar to theirs is presented here together with a new computational procedure for removing the noise. Results from normal rest studies on ten healthy young males indicate that the approximations for arterial blood concentration obtained from end-tidal air and from corrected lung counts are not equivalent when 133Xe is administered by inhalation. The concentration-time curves have different shapes, and these differences are reflected in blood flow values computed by head channel. However, there is no effect on comparisons between homologous regions of the left and right hemispheres.

  5. 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. PMID:26682890

  6. 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.

  7. Simulating the venting of radioactivity from a soviet nuclear test

    NASA Astrophysics Data System (ADS)

    Rodriguez, Daniel J.; Peterson, Kendall R.

    Fresh fission products were found in several routine air samples in Europe during the second and third weeks of March 1987. Initially, it was suspected that the radionuclides, principally 133Xe and 131I, had been accidentally released from a European facility handling nuclear materials. However, the announcement of an underground nuclear test at Semipalatinsk, U.S.S.R. on 26 February 1987 suggested that the elevated amounts of radioactivity may, instead, have been caused by a venting episode. Upon learning of these events, we simulated the transport and diffusion of 133Xe with our Hemispheric MEDIC and ADPIC models, assuming Semipalatinsk to be the source of the radioactive emissions. The correspondence between the calculated concentrations and the daily average 133Xe measurements made by the Federal Office for Civil Protection in F.R.G. was excellent. While this agreement does not, in itself, prove that an atmospheric venting of radioactive material occurred at Semipalatinsk, a body of circumstantial evidence exists which, when added together, strongly supports this conclusion. Our calculations suggested a total fission yield of about 40 kt, which is within the 20-150 kt range of tests acknowledged by the U.S.S.R. Finally, dose calculations indicated that no health or environmental impact occurred outside of the U.S.S.R. due to the suspected venting of 133Xe. However, the inhalation dose resulting from 133I, an unmodeled component of the radioactive cloud, represented a greater potential risk to public health.

  8. 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

  9. 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.

  10. Detection of radioxenon in Darwin, Australia following the Fukushima Dai-ichi nuclear power plant accident.

    PubMed

    Orr, Blake; Schöppner, Michael; Tinker, Rick; Plastino, Wolfango

    2013-12-01

    A series of (133)Xe detections in April 2011 made at the Comprehensive Nuclear-Test-Ban Treaty Organisation (CTBTO) International Monitoring System noble gas station in Darwin, Australia, were analysed to determine the most likely source location. Forward and backwards atmospheric transport modelling simulations using FLEXPART were conducted. It was shown that the most likely source location was the Fukushima Dai-ichi nuclear power plant accident. Other potential sources in the southern hemisphere were analysed, including the Australian Nuclear Science and Technology Organisation (ANSTO) radiopharmaceutical facility, but it was shown that sources originating from these locations were highly unlikely to be the source of the observed (133)Xe Darwin detections. PMID:23933085

  11. 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.

  12. Effects of platelet activating factor (PAF) and other vasoconstrictors on a model of angiogenesis in the mouse.

    PubMed

    Andrade, S P; Vieira, L B; Bakhle, Y S; Piper, P J

    1992-08-01

    The combination of sponge implant and 133Xe washout technique described in this paper provides a model to study neovascularization in mice which can be observed over several days in the same animal. The local blood flow within the ingrowing granulation tissue has been determined by measuring the washout rate of 133Xe injected into the implants. Tissue infiltration of the sponges was assessed by histological examination and by measurement of sponge wet weight, protein and glycosaminoglycans (GAG) content. The newly formed blood vessels, despite having abnormal configuration, responded to platelet activating factor (PAF) and to endothelin-1 (ET-1) similarly to the normal mature vessels in adjacent skin. However, the sponge blood vessels were more sensitive to angiotensin II than the skin blood vessels. Using this model we have also demonstrated an angiogenic activity of PAF substantiated by increased blood flow and biochemical variables in the implanted sponges. PMID:1382541

  13. 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.

  14. Source term estimates of radioxenon released from the BaTek medical isotope production facility using external measured air concentrations.

    PubMed

    Eslinger, Paul W; Cameron, Ian M; Dumais, Johannes Robert; Imardjoko, Yudi; Marsoem, Pujadi; McIntyre, Justin I; Miley, Harry S; Stoehlker, Ulrich; Widodo, Susilo; Woods, Vincent T

    2015-10-01

    BATAN Teknologi (BaTek) operates an isotope production facility in Serpong, Indonesia that supplies (99m)Tc for use in medical procedures. Atmospheric releases of (133)Xe in the production process at BaTek are known to influence the measurements taken at the closest stations of the radionuclide network of the International Monitoring System (IMS). The purpose of the IMS is to detect evidence of nuclear explosions, including atmospheric releases of radionuclides. The major xenon isotopes released from BaTek are also produced in a nuclear explosion, but the isotopic ratios are different. Knowledge of the magnitude of releases from the isotope production facility helps inform analysts trying to decide if a specific measurement result could have originated from a nuclear explosion. A stack monitor deployed at BaTek in 2013 measured releases to the atmosphere for several isotopes. The facility operates on a weekly cycle, and the stack data for June 15-21, 2013 show a release of 1.84 × 10(13) Bq of (133)Xe. Concentrations of (133)Xe in the air are available at the same time from a xenon sampler located 14 km from BaTek. An optimization process using atmospheric transport modeling and the sampler air concentrations produced a release estimate of 1.88 × 10(13) Bq. The same optimization process yielded a release estimate of 1.70 × 10(13) Bq for a different week in 2012. The stack release value and the two optimized estimates are all within 10% of each other. Unpublished production data and the release estimate from June 2013 yield a rough annual release estimate of 8 × 10(14) Bq of (133)Xe in 2014. These multiple lines of evidence cross-validate the stack release estimates and the release estimates based on atmospheric samplers. PMID:26093852

  15. 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.

  16. Effect of platelet activating factor (PAF) on the formation of blood vessels in subcutaneous implants in mice.

    PubMed

    Andrade, S P; Vieira, L B; Bakhle, Y S; Piper, P J

    1994-03-01

    Angiogenesis accompanies inflammatory processes and many other pathological conditions. We have studied the effect of platelet-activating factor (PAF) a well-known inflammatory mediator, as a promoter of angiogenesis in the sponge implant model in mice. Development of blood vessels and blood flow were monitored by use of a 133Xe washout technique. The results showed PAF to have angiogenic activity, which was inhibited by WEB 2086, and the PAF-induced vasculature to have normal pharmacological reactivity. PMID:7516807

  17. 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.

  18. A fence line noble gas monitoring system for nuclear power plants.

    PubMed

    Grasty, R L; Hovgaard, J; LaMarre, J R

    2001-01-01

    A noble gas monitoring system has been installed at Ontario Power Generation's Pickering Nuclear Generating Station (PNGS) near Toronto, Canada. This monitoring system allows a direct measure of air kerma from external radiation instead of calculating this based on plant emission data and meteorological models. This has resulted in a reduction in the reported effective dose from external radiation by a factor of at least ten. The system consists of nine self-contained units, each with a 7.6 cm x 7.6 cm (3 inch x 3 inch) NaI(TI) detector that is calibrated for air kerma. The 512-channel gamma ray spectral information is downloaded daily from each unit to a central computer where the data are stored and processed. A spectral stripping procedure is used to remove natural background variations from the spectral windows used to monitor xenon-133 (133Xe), xenon-135 (135Xe), argon-41 (41Ar), and skyshine radiation from the use of radiography sources. Typical monthly minimum detection limits in air kerma are 0.3 nGy for 133Xe, 0.7 nGy for 35Xe, 3 nGy for 41Ar and 2 nGy for skyshine radiation. Based on 9 months of continuous operation, the annualised air kerma due to 133Xe, 135Xe and 41Ar and skyshine radiation were 7 nGy, 8 nGy, 26 nGy and 107 nGy respectively. PMID:11605799

  19. 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

  20. 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.

  1. 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.

  2. 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.

  3. 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

  4. 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.

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

    PubMed

    Formby, C; Thomas, R G; Halsey, J H

    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 133Xe-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. PMID:2720376

  6. 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.

  7. Disturbances in the cerebral perfusion of human immune deficiency virus-1 seropositive asymptomatic subjects: A quantitative tomography study of 18 cases

    SciTech Connect

    Tran Dinh, Y.R.; Mamo, H.; Cervoni, J.; Caulin, C.; Saimot, A.C. , Paris )

    1990-10-01

    Quantitative measurements of cerebral blood flow (CBF) by xenon-133 ({sup 133}Xe) tomography, together with magnetic resonance imaging (MRI), electroencephalography (EEG), psychometric tests, and laboratory analyses were performed on 18 human immunodeficiency virus 1 (HIV-1) seropositive asymptomatic subjects. Abnormalities of cerebral perfusion were observed in 16 cases (88%). These abnormalities were particularly frequent in the frontal regions (77% of cases). MRI demonstrated leucoencephalopathy in only two cases. EEG showed only induced diffuse abnormalities in two cases. Psychometric tests showed restricted moderate disturbances in 55% of patients. These disturbances mostly concerned those sectors involved in cognitive functions and memorization. These results indicate that quantitative measurements of CBF by {sup 133}Xe-SPECT is capable of detecting abnormalities of cerebral perfusion at a very early stage (Phase II) of HIV-1 infection. These abnormalities are indications of disturbances resulting from unidentified metabolic or vascular lesions. This technique appears to be superior to MRI at this stage of the disease's development. It could provide objective information leading to earlier treatment, and prove useful in evaluating potential antiviral chemotherapy.

  8. 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.

  9. 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.

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

    PubMed

    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. PMID:7163722

  11. 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.

  12. 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.

  13. Effects of tumour cells on angiogenesis and vasoconstrictor responses in sponge implants in mice.

    PubMed

    Andrade, S P; Bakhle, Y S; Hart, I; Piper, P J

    1992-11-01

    The effects of tumour cells (Colon 26) on the development and response of new blood vessels to different vasoconstrictors (platelet activating factor; PAF, endothelin-1, angiotensin II, adrenalin and 5-hydroxytryptamine) have been investigated. Sponge implants in mice were used to host tumour cells while washout of 133Xe was employed to assess local blood flow in the implanted sponges. By 14 days after implantation the response of vessels in tumour-bearing implants to the various vasoconstrictors generally was decreased compared to that obtained in control sponge implants or adjacent normal skin. Thus at this time point the t1/2 for 133Xe washout from control sponges treated with adrenalin (0.5 micrograms) was 30 +/- 4 min whereas in tumour-bearing sponges it was 5 +/- 1 min. This decreased sensitivity in tumour vessels was probably not due to a complete lack of contractile elements since actin was demonstrated by immunohistochemistry around blood vessels in both types of implant. The results of the present study have shown that the pharmacological responses of blood vessels in a growing tumour, Colon 26, differed from the responses of vessels of a similar age in non-neoplastic tissue. These results appear to suggest that the different angiogenic stimuli released from tumour tissue may markedly influence pharmacological reactivity of newly formed blood vessels. PMID:1384642

  14. 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).

  15. 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.

  16. 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.

    2015-09-01

    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) sulphate aerosols were the main carriers for the cesium. Hence, 137Cs can be used as a proxy tracer for the AM sulphate 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 sulphate, and 133Xe emissions that were assigned to a passive tracer. We investigate to what extent the modelled sulphate tracer can reproduce the measurements, especially with respect to the observed loss of aerosol mass with time. Modelled 37Cs 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 two and nine weeks after the start of the emissions, is 14.3 days

  17. 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

  18. 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

  19. 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.

  20. Low level radioactivity measurement in support of the CTBTO. Comprehensive Nuclear-Test-Ban Treaty Organization

    PubMed

    Schulze; Auer; Werzi

    2000-07-01

    Radioactivity measurements, together with three other technologies: seismic, hydroacoustic and infrasound, are able to detect, identify and locate nuclear explosions down to 1 kt. Eighty stations worldwide, with a sensitivity of 10-30 microBq/m3 for 140Ba and 1 mBq/m m3 for 133Xe, have been or will be established in order to provide an estimated 90% detection probability within 10 days after a nuclear explosion. The equipment for manual stations--the high volume samplers, high sensitivity HPGe detectors and auxiliary measurement systems, as well as the automatic stations are described. The problems and results of atmospheric transport, site location as well as equipment and station operation are discussed. PMID:10879833

  1. Analysis of 125Xe electron–photon coincidence decay

    DOE PAGESBeta

    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

  2. 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.

  3. 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.

  4. 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

  5. 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

  6. Pentobarbital changes compartmental contribution to cerebral blood flow

    SciTech Connect

    Laurent, J.P.; Lawner, P.; Simeone, F.A.; Fink, E.

    1982-04-01

    Barbiturates were administered to normal dogs, establishing an isoelectric electrocorticogram. Cortical cerebral blood flows (CBF) and deeper CBF's were respectively measured by krypton-85 (85Kr) and xenon-133 (133 Xe). Following barbiturate administration, the two methods of measuring CBF showed a poor coefficient of variation (r.0.12, p less than 0.05). The cortical flows decreased less than the fast compartment flows. A shifting of percentage contribution of flow to the slow compartment (60% increase, p less than 0.001) was observed after barbiturate infusion. A selective shunting of blood flow to the slower areas may explain the lowering of intracranial pressure and protection of the deep white matter observed by many authors who use barbiturates in clinical an experimental situations.

  7. 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.

  8. Effect of external pressure on intramuscular blood flow at rest and after running

    SciTech Connect

    Thorsson, O.; Hemdal, B.; Lilja, B.; Westlin, N.

    1987-10-01

    Local blood flow in the thigh was measured with /sup 133/Xe clearance technique in eight male distance runners after compression with a foam rubber compress and a standard elastic bandage. Two degrees of compression were tested, and an initial experiment with rested subjects was followed by a similar experiment immediately after running. Maximum compression exerted a cutaneous pressure of 85 (+/- 8) mm Hg and caused an immediate cessation of intra-muscular blood flow in the compressed area. Moderate compression gave a cutaneous pressure of 40 (+/- 5) mm Hg and resulted in a reduction of blood flow by approximately 50%. During compression, there were no significant differences in the blood flow of rested subjects compared to subjects immediately after running. In acute soft tissue injuries, a maximum compression bandage should effectively reduce or eliminate the formation of an intra-muscular hematoma, and an additive effect on blood flow of ice should not be expected.

  9. 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.

  10. Measurement of relative K X-ray intensity ratio following radioactive decay and photoionization

    NASA Astrophysics Data System (ADS)

    Yalçın, P.

    2007-01-01

    The measurements of the K X-ray intensity ratio I(Kα2/Kα1), I(Kβ1/Kα1) and I(Kβ/Kα) for elements V, Mn, Zn, Tc, Ru, Cd, Xe, Ba, Cs, Hg and Rn were experimentally determined both by photon excitation, in which 59.5 keV γ-rays from a 241Am and 123.6 keV γ-rays from a 60Co were used, and following the radioactive decay of 51Cr, 55Fe, 67Ga, 99Tc, 111In, 131I, 133Ba, 133Xe, 137Cs, 201Tl and 226Ra. K X-rays emitted by samples were counted by a Si(Li) detector with resolution 160 eV at 5.9 keV. Obtained values were compared with the theoretical values. It was observed that present values agree with the previous theoretical and other experimental results.

  11. Effect of flunarizine on regional cerebral blood flow in common and complicated migraine. Pilot study.

    PubMed

    Lagrèze, H L; Tsuda, Y; Hartmann, A; Bülau, P

    1986-01-01

    Alterations of regional cerebral blood flow (rCBF) are at least epiphenomena of common and complicated migraine, but may lead to serious clinical complications. Since flunarizine seems to be effective in migraine prevention it may exert a beneficial influence on rCBF in migraine as well. rCBF was assessed using the 133Xe inhalation method in 5 patients with common and 8 patients with complicated migraine. Measurements were done interictally prior and after therapy with 15 mg flunarizine p.o. daily over a period of 4 weeks. Major abnormalities of grey matter flow were observed even interictally. Significant improvement of rCBF in initially hypoemic regions may be attributed to flunarizine therapy. These preliminary data suggest that calcium entry blockers may prevent the ischemic complications of migraine. PMID:3093236

  12. 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.

  13. Regional myocardial blood flow in man during dipyridamole coronary vasodilation

    SciTech Connect

    Sorensen, S.G.; Groves, B.M.; Horwitz, L.D.; Chaudhuri, T.K.

    1985-06-01

    Regional myocardial blood flow before and after intravenous dipyridamole (0.56 mg/kg) was measured during cardiac catheterization in 11 patients using the /sup 133/Xe washout technique. Significant increases in heart rate and decreases in systolic blood pressure were observed with dipyridamole infusion. However, double product and cardiac output did not differ before or after drug infusion. Regional myocardial blood flow increased from 67 to 117 ml/100 mg/min in myocardial segments supplied by nonobstructed coronary arteries. In stenotic coronary arteries, flow increased from 57 to 79 ml/100 mg/min with dipyridamole. We conclude that dipyridamole infusion results in flow differences which discriminate stenotic from nonstenotic coronary arteries.

  14. 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.

  15. 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.

  16. 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.

  17. Role of scintigraphy in focally abnormal sonograms of fatty livers

    SciTech Connect

    Lisbona, R.; Mishkin, S.; Derbekyan, V.; Novales-Diaz, J.A.; Roy, A.; Sanders, L.

    1988-06-01

    Fatty infiltration of the liver may cause a range of focal abnormalities on hepatic sonography which may simulate hepatic nodular lesions. Discrete deposits of fat or islands of normal tissue which are uninvolved by fatty infiltration may stand out as potential space-occupying lesions on the sonograms. Twelve patients with such focally abnormal ultrasound images were referred for liver scintigraphy with /sup 133/Xe and /sup 99m/Tc colloidal SPECT studies to clarify the issue. These examinations helped identify, in nine of 12 patients, the innocent nature of the sonographic abnormalities which were simply related to the fat deposition process. Further, (/sup 99m/Tc)RBC scans defined the additional pathologic process in three patients in whom actual space-occupying lesions were indeed present in the liver. Scintigraphy has an important role to play in the understanding of focal hepatic ultrasound abnormalities particularly in unsuspected hepatic steatosis.

  18. 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.

  19. Pharmacological reactivity of neoplastic and non-neoplastic associated neovasculature to vasoconstrictors.

    PubMed

    Andrade, S P; Beraldo, W T

    1998-12-01

    Angiogenesis and the pharmacological responses of the tumour and non-tumour associated neovasculature have been investigated. Cannulated sponge discs in mice were used to host the angiogenic stimulators, while 133Xe washout was employed to assess local blood flow. Enhancement of blood flow was detected in implants bearing B16 cells, 3T3 cells and angiotensin II (AII)-treated at day 7. The responses of non-neoplastic associated neovasculature at day 14 post sponge implantation to the vasoconstrictors used endothelin-1 (Et-1), AII, platelet activating factor (PAF) and 5-hydroxytryptamine (5-HT) were dose-dependent. By contrast, the newly formed blood vessels induced by tumour cells were markedly insensitive to the vasoconstrictors agonists Et-1 and AII, while fully responsive to PAF and 5-HT. The vessels resulting from neoplastic stimulus exhibited altered pharmacological reactivity, suggesting that the characteristics of the neovasculature are dependent on the nature of the angiogenic stimuli. PMID:10319023

  20. 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.

  1. 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.

  2. 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

  3. Ambulatory measurement of nocturnal fluctuations in subcutaneous blood flow rate in the lower leg of man during 12-h periods with the portable CdTe(Cl) detector. Methodological considerations.

    PubMed

    Sindrup, J H; Kastrup, J; Jørgensen, B; Bülow, J; Tønnesen, K H

    1991-07-01

    Possible sources of error during long-term measurements of subcutaneous blood flow rate with the portable CdTe(Cl) detector system were ruled out in the present study. Local blood flow rates were recorded in the lower legs of normal human subjects by means of the 133Xe wash-out technique. A good correlation was found between the portable CdTe(Cl) and stationary NaI(Tl) detector systems both prior to (r = 0.88, P less than 0.0001) and after (r = 0.68, P = 0.07) day over night (12 h) measurements. Identical post-ischaemic reactive hyperaemia could be demonstrated by both detector systems 12 h after the application of the isotope depot. This indicates that blood flow rates and vascular reactivity can be measured over 12 h by the portable CdTe(Cl) detector. Identical results were obtained during the 12-h measurements performed with the portable CdTe(Cl) detector attached directly to the skin surface and with the detector elevated above the skin surface. Therefore, geometrical changes were without any influence on our measurements. We conclude that measurements of subcutaneous blood flow rates in the lower leg of human subjects can be performed under out-patients conditions by means of the 133Xe wash-out technique and portable CdTe(Cl) detectors. A skin area greater than or equal to 4 cm should be labelled by means of the atraumatic, epicutaneous labelling technique and the detector attached directly to the skin surface with a single layer of a 20-micron thick gas-tight Mylar membrane interposed between the skin surface and the detector. The investigation of the subcutaneous blood flow rate should not be initiated until at least 90 min after labelling.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:1914438

  4. 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.

  5. 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

  6. 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

  7. Measurement of fission product gases in the atmosphere

    NASA Astrophysics Data System (ADS)

    Schell, W. R.; Tobin, M. J.; Marsan, D. J.; Schell, C. W.; Vives-Batlle, J.; Yoon, S. R.

    1997-01-01

    The ability to quickly detect and assess the magnitude of releases of fission-produced radioactive material is of significant importance for ongoing operations of any conventional nuclear power plant or other activities with a potential for fission product release. In most instances, the control limits for the release of airborne radioactivity are low enough to preclude direct air sampling as a means of detection, especially for fission gases that decay by beta or electron emission. It is, therefore, customary to concentrate the major gaseous fission products (krypton, xenon and iodine) by cryogenic adsorption for subsequent separation and measurement. This study summarizes our initial efforts to develop an automated portable system for on-line separation and concentration with the potential for measuring environmental levels of radioactive gases, including 85Kr, 131,133,135Xe, 14C, 3H, 35S, 125,131I, etc., without using cryogenic fluids. Bench top and prototype models were constructed using the principle of heatless fractionation of the gases in a pressure swing system. This method removes the requirement for cryogenic fluids to concentrate gases and, with suitable electron and gamma ray detectors, provides for remote use under automatic computer control. Early results using 133Xe tracer show that kinetic chromatography, i.e., high pressure adsorption of xenon and low pressure desorption of air, using specific types of molecular sieves, permits the separation and quantification of xenon isotopes from large volume air samples. We are now developing the ability to measure the presence and amounts of fission-produced xenon isotopes that decay by internal conversion electrons and beta radiation with short half-lives, namely 131mXe, 11.8 d, 133mXe, 2.2 d, 133Xe, 5.2 d and 135Xe, 9.1 h. The ratio of the isotopic concentrations measured can be used to determine unequivocally the amount of fission gas and time of release of an air parcel many kilometers downwind from a

  8. Comparison of 133Xenon Ventilation Equilibrium Scan (XV) and 99mTechnetium Transmission (TT) Scan for Use in Regional Lung Analysis by 2D Gamma Scintigraphy in Healthy and Cystic Fibrosis Lungs

    PubMed Central

    Wu, Jihong; Donaldson, Scott H.; Bennett, William D.

    2013-01-01

    Abstract Background Quantification of particle deposition in the lung by gamma scintigraphy requires a reference image for location of regions of interest (ROIs) and normalization to lung thickness. In various laboratories, the reference image is made by a transmission scan (57Co or 99mTc) or gas ventilation scan (133Xe or 81Kr). There has not been a direct comparison of measures from the two methods. Methods We compared 99mTc transmission scans to 133Xe equilibrium ventilation scans as reference images for 38 healthy subjects and 14 cystic fibrosis (CF) patients for their effects on measures of regional particle deposition: the central-to-peripheral ratio of lung counts (C/P); and ROI area versus forced vital capacity. Whole right lung ROI was based on either an isocontour threshold of three times the soft tissue transmission (TT) or a threshold of 20% of peak xenon ventilation counts (XV). We used a central ROI drawn to 50% of height and of width of the whole right lung ROI and placed along the left lung margin and centered vertically. Results In general, the correlation of normalized C/P (nC/P) between the two methods was strong. However, the value of nC/P was significantly smaller for the XV method than the TT method. Regression equations for the relationship of nC/P between the two methods were, for healthy subjects, y=0.75x+0.61, R2=0.64 using rectangular ROIs and y=0.76x+0.45, R2=0.66 using isocontour ROIs; and for CF patients, y=0.94x+0.46, R2=0.43 and y=0.85x+0.42, R2=0.41, respectively. Conclusions (1) A transmission scan with an isocontour outline in combination with a rectangular central region to define the lung borders may be more useful than a ventilation scan. (2) Close correlation of nC/Ps measured by transmission or gas ventilation should allow confident comparison of values determined by the two methods. PMID:23421899

  9. Relationship between regional ventilation and aerosol deposition in tidal breathing

    SciTech Connect

    Trajan, M.; Logus, J.W.; Enns, E.G.; Man, S.F.

    1984-07-01

    The regional distribution of the deposition of 1.2 micron particles of 99mTc sulfur colloid inhaled by tidal breathing was compared with the distribution of ventilation as measured by a 133Xe washout technique. Twelve subjects were studied, 6 with normal pulmonary function tests, 5 with air-flow limitation, and 1 with unilateral phrenic nerve paralysis. Both xenon and aerosol were inhaled at tidal volume by the subjects while seated upright. A large field gamma camera acquired posterior scans. Thirteen experiments were also done on 7 dogs: 1 with extrathoracic obstruction of the airway to 1 lung, and 12 with bronchoconstriction from the instillation of methacholine chloride into the airways of a lower lobe. Two of these dogs were studied with a gamma camera system, and the others were studied with a Picker multi-probe system. Both in humans and in dogs, an increase in time constant, which indicated a decrease in ventilation, was associated with an increase in peripheral aerosol deposition when normalized for ventilation. It is suggested that the increased residence time is responsible for the increased deposition in regions that received lesser ventilation.

  10. 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.

  11. 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.

  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. 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

  15. 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.

  16. Radioxenon spiked air

    DOE PAGESBeta

    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. 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.

  18. 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.

  19. Cerebral blood flow is reduced in patients with sepsis syndrome

    SciTech Connect

    Bowton, D.L.; Bertels, N.H.; Prough, D.S.; Stump, D.A.

    1989-05-01

    The relationship between sepsis-induced CNS dysfunction and changes in brain blood flow remains unknown, and animal studies examining the influence of sepsis on cerebral blood flow (CBF) do not satisfactorily address that relationship. We measured CBF and cerebrovascular reactivity to CO/sub 2/ in nine patients with sepsis syndrome using the /sup 133/Xe clearance technique. Mean CBF was 29.6 +/- 15.8 (SD) ml/100 g.min, significantly lower than the normal age-matched value in this laboratory of 44.9 +/- 6.2 ml/100 g.min (p less than .02). This depression did not correlate with changes in mean arterial pressure. Despite the reduction in CBF, the specific reactivity of the cerebral vasculature to changes in CO/sub 2/ was normal, 1.3 +/- 0.9 ml/100 g.min/mm Hg. Brain blood flow is reduced in septic humans; the contribution of this reduction to the metabolic and functional changes observed in sepsis requires further study.

  20. 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).

  1. Xenon spill distribution and room clearance.

    PubMed

    Kelsey, C A; Telepak, R J

    1999-11-01

    The purpose of these studies was to investigate actual xenon gas clearance times under different exhaust conditions, to compare them with the calculated clearance times, to observe the distribution of the xenon gas while it was being exhausted from the room, and to determine the cause of a stationary xenon cloud that appeared on some clinical images. Clearance times with and without a flexible exhaust hose placed next to a simulated 133Xe gas spill were compared with clearance times measured in a room with all exhaust closed off. Two gamma cameras were used to observe the transport and exhaust of xenon following a simulated spill. Clearance times with the flexible exhaust hose were less than one minute because the xenon gas was removed before it had a chance to disperse into the room. Conventional room clearance calculations based on uniform mixing and measured exhaust rates yielded a clearance time of 22 min. The source of an artifactual stationary cloud image was discovered to be a small amount of xenon trapped between the collimator and camera face. A negative pressure and dedicated exhaust can be even more effective in exhausting spilled xenon from a room than air transfer calculations predict. The authors believe the flexible hose should always be used. PMID:10524516

  2. 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.

  3. Regional cerebral function and blood flow: complementary single photon emission computed tomography of the brain using xenon-133 and [123I]iodoamphetamine.

    PubMed

    Simon, T R; Devous, M D; Paulman, R G; Gregory, R; Homan, R W; Judd, C; Triebel, J G; Matthiesen, S; Raese, J D; Bonte, F J

    1989-01-01

    Regional cerebral function and blood flow can be imaged using isopropyl[123I]iodoamphetamine (IMP), or 133Xe (DSPECT), respectively. Both of these essentially non-invasive, quantitative, methods are suitable for many nuclear medicine laboratories. This study assessed the in vivo information about intracerebral disease provided by IMP and DSPECT techniques to determine the optimal diagnostic use of these modalities. Single photon emission computed tomograms of 53 subjects were acquired using similar displays for IMP and DSPECT data. Lobar tracer distributions were graded by three experienced observers and analyzed using a kappa statistic to eliminate chance agreements. Overall, both IMP and DSPECT had similar patterns. However, while similar, one or the other technique often displayed abnormalities not present on both. Although technical factors may account for some differences between the modalities, a case of arteriovenous malformation proves that discordant findings can result directly from tracer localization properties. Thus at least some discordances provide truly complementary diagnostic information lacking in either single study taken alone. PMID:2785513

  4. 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.

  5. 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.

  6. Cerebral hemodynamics in patients with chronic obstructive carotid disease by rCBF, rCBV, and rCBV/rCBF ratio using SPECT

    SciTech Connect

    Toyama, H.; Takeshita, G.; Takeuchi, A.; Anno, H.; Ejiri, K.; Maeda, H.; Katada, K.; Koga, S.; Ishiyama, N.; Kanno, T. )

    1990-01-01

    To evaluate cerebral hemodynamics, 21 patients with chronic occlusion or severe stenosis of the internal carotid or middle cerebral artery with normal or only lacunar infarction on x-ray CT were studied using single photon emission computed tomography (SPECT). We measured rCBV with 99mTc erythrocytes after rCBF with 133Xe, and calculated rCBV/rCBF. rCBF and rCBV of the 25 affected hemispheres were classified as (a) patients with normal rCBF (type I (n = 7) and type II (n = 3)); (b) patients with decreased rCBF (type III (n = 6) and type IV (n = 9)). These two groups then could be subdivided according to findings of rCBV, normal, and increased blood volumes. rCBV/rCBF increased as the cerebral perfusion pressure dropped from type I to type III. In type IV, other situations but cerebral autoregulation could be assumed. rCBV/rCBF signifies vascular mean transit time. Type III (high rCBV/rCBF) assumed as the increased OEF, misery perfusion as reported in PET. We propose rCBF, rCBV and rCBV/rCBF using SPECT can be an index for cerebral circulatory reserve.

  7. Automatic radioxenon analyzer for CTBT monitoring

    SciTech Connect

    Bowyer, T.W.; Abel, K.H.; Hensley, W.K.

    1996-12-01

    Over the past 3 years, with support from US DOE`s NN-20 Comprehensive Test Ban Treaty (CTBT) R&D program, PNNL has developed and demonstrated a fully automatic analyzer for collecting and measuring the four Xe radionuclides, {sup 131m}Xe(11.9 d), {sup 133m}Xe(2.19 d), {sup 133}Xe (5.24 d), and {sup 135}Xe(9.10 h), in the atmosphere. These radionuclides are important signatures in monitoring for compliance to a CTBT. Activity ratios permit discriminating radioxenon from nuclear detonation and that from nuclear reactor operations, nuclear fuel reprocessing, or medical isotope production and usage. In the analyzer, Xe is continuously and automatically separated from the atmosphere at flow rates of about 7 m{sup 3}/h on sorption bed. Aliquots collected for 6-12 h are automatically analyzed by electron-photon coincidence spectrometry to produce sensitivities in the range of 20-100 {mu}Bq/m{sup 3} of air, about 100-fold better than with reported laboratory-based procedures for short time collection intervals. Spectral data are automatically analyzed and the calculated radioxenon concentrations and raw gamma- ray spectra automatically transmitted to data centers.

  8. Uncertainty quantification for discrimination of nuclear events as violations of the comprehensive nuclear-test-ban treaty.

    PubMed

    Sloan, Jamison; Sun, Yunwei; Carrigan, Charles

    2016-05-01

    Enforcement of the Comprehensive Nuclear Test Ban Treaty (CTBT) will involve monitoring for radiologic indicators of underground nuclear explosions (UNEs). A UNE produces a variety of radioisotopes which then decay through connected radionuclide chains. A particular species of interest is xenon, namely the four isotopes (131m)Xe, (133m)Xe, (133)Xe, and (135)Xe. Due to their half lives, some of these isotopes can exist in the subsurface for more than 100 days. This convenient timescale, combined with modern detection capabilities, makes the xenon family a desirable candidate for UNE detection. Ratios of these isotopes as a function of time have been studied in the past for distinguishing nuclear explosions from civilian nuclear applications. However, the initial yields from UNEs have been treated as fixed values. In reality, these independent yields are uncertain to a large degree. This study quantifies the uncertainty in xenon ratios as a result of these uncertain initial conditions to better bound the values that xenon ratios can assume. We have successfully used a combination of analytical and sampling based statistical methods to reliably bound xenon isotopic ratios. We have also conducted a sensitivity analysis and found that xenon isotopic ratios are primarily sensitive to only a few of many uncertain initial conditions. PMID:26994449

  9. Cerebral circulatory and metabolic effects of 5-hydroxytryptamine in anesthetized baboons.

    PubMed Central

    Harper, M A; MacKenzie, E T

    1977-01-01

    1. The cerebral circulatory effects of the intracarotid administration of 5-hydroxytryptamine were examined in anaesthetized baboons. Cerebral blood flow was measured by the intracarotid 133Xe technique, cerebral O2 consumption and glucose uptake were measured as indices of brain metabolism and electrocortical activity was continuously monitored. 2. Despite a marked reduction in the calibre of the internal carotid artery (assessed angiographically), the intracarotid infusion of 5-hydroxytryptamine 0-1 microgram/kg. min did not effect any significant changes in cerebral blood flow, O2 consumption or glucose uptake. 3. Following transient osmotic disruption of the blood-brain barrier with the intracarotid infusion of hypertonic urea, the same dose of 5-hydroxytryptamine effected a marked reduction in cerebral blood flow from 51 +/- 2 to 36 +/- 2 ml./100 g. min (mean +/- S.E.; P less than 0-01). Both indices of cerebral metabolism were reduced significantly and the e.e.g. showed a more pronounced suppression-burst pattern. 4. We postulate that the cerebral circulatory responses to 5-hydroxytryptamine are dependent upon the integrity of the blood-brain barrier and the predominant effect of the intravascular administration of 5-hydroxytryptamine is on cortical activity or metabolism, rather than on cerebrovascular smooth muscle. Images Plate 1 PMID:411921

  10. 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

  11. RangerMaster{trademark}: Real-time pattern recognition software for in-field analysis of radiation sources

    SciTech Connect

    Murray, W.S.; Ziemba, F.; Szluk, N.

    1998-12-31

    RangerMaster{trademark} is the embedded firmware for Quantrad Sensor`s integrated nuclear instrument package, the Ranger{trademark}. The Ranger{trademark}, which is both a gamma-ray and neutron detection system, was originally developed at Los Alamos National Laboratory for in situ surveys at the Plutonium Facility to confirm the presence of nuclear materials. The new RangerMaster{trademark} software expands the library of isotopes and simplifies the operation of the instrument by providing an easy mode suitable for untrained operators. The expanded library of the Ranger{trademark} now includes medical isotopes {sup 99}Tc, {sup 201}Tl, {sup 111}In, {sup 67}Ga, {sup 133}Xe, {sup 103}Pa, and {sup 131}I; industrial isotopes {sup 241}Am, {sup 57}Co, {sup 133}Ba, {sup 137}Cs, {sup 40}K, {sup 60}Co, {sup 232}Th, {sup 226}Ra, and {sup 207}Bi; and nuclear materials {sup 235}U, {sup 238}U, {sup 233}U, and {sup 239}Pu. To accomplish isotopic identification, a simulated spectrum for each of the isotopes was generated using SYNTH. The SYNTH spectra formed the basis for the knowledge-based expert system and selection of the regions of interest that are used in the pattern recognition system. The knowledge-based pattern recognition system was tested against actual spectra under field conditions.

  12. 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.

  13. 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. PMID:22137556

  14. Insulin absorption and subcutaneous blood flow in normal subjects during insulin-induced hypoglycemia

    SciTech Connect

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

    1988-09-01

    We studied the effects of insulin-induced hypoglycemia on the absorption of 10 U /sup 125/I-labeled soluble human insulin injected sc in the thigh in 10 normal subjects. The disappearance of /sup 125/I from the injection site was followed by external gamma-counting. Subcutaneous blood flow (ATBF) was measured concomitantly with the 133Xe washout technique. The plasma glucose nadir (mean, 2.0 +/- 0.1 (+/- SE) mmol/L) occurred at 33 +/- 3 min and resulted in maximal arterial plasma epinephrine concentrations of approximately 6 nmol/L. From 30 min before to 60 min after the glucose nadir the (/sup 125/I)insulin absorption rate was depressed compared to that during normoglycemia. The first order disappearance rate constants were reduced by approximately 50% (P less than 0.01) during the first 30-min interval after the glucose nadir. During the same period ATBF increased by 100% (P less than 0.05). The results suggest that in normal subjects the absorption of soluble insulin from a sc depot is depressed in connection with hypoglycemia, despite considerably elevated ATBF.

  15. 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.

  16. The imaging of myocardial perfusion with 81mKr during coronary arteriography.

    PubMed

    Kleynhans, P H; Lötter, M G; van Aswegen, A; Herbst, C P; Marx, J D; Minnaar, P C

    1982-01-01

    The use of 81mKr was investigated for imaging myocardial perfusion during coronary arteriography using conventional catheters. When the significance of stenosis judged by arteriography is unclear, the effect on tissue perfusion can be established and the contribution to collateral flow by each artery separately evaluated. The distribution of 81mKr, due to its 13-s half-life, represents regional blood flow. In order to evaluate interventions, studies can be repeated at a low radiation risk to patients. A sterile pyrogen-free 81Rb-81Kr generator was developed. With slow infusion, inadequate mixing and streaming takes place due to laminar flow in coronary arteries. Fast intermittent 3-ml 81Kr-dextrose bolus injections convincingly eliminated streaming artefacts. Imaging was performed in 13 patients with a mobile scintillation camera and digital imaging system. Blood flow was calculated using the inert gas washout technique. There was good correlation (r = 0.91) between coronary blood flow determinations using 81mKr and 133Xe respectively. The perfusion images correlated well with the coronary angiograms. Total coronary arterial occlusions as demonstrated by arteriography were all shown as perfusion defects during rest. During atrial pacing myocardial flow was increased two-fold in normal coronary arteries and to a lesser extent in arteries with significant disease. The most critical lesion in a branch of a left coronary artery leads to a redistribution of perfusion during pacing. PMID:7128629

  17. Effects of continuous phonation on /sup 133/xenon-inhalation air curves (of the kind used in deriving regional cerebral blood flow)

    SciTech Connect

    Formby, C.; Thomas, R.G.; Brown, W.S. Jr.; Halsey, J.H. Jr.

    1987-07-01

    Regional cerebral blood flow (rCBF) may be measured with inhalation techniques that use end-expired values of radioactivity to estimate the isotope concentration in arterial blood. These end-expired data are used as an input function in a mathematical equation to derive rCBF. End-expired air is assumed normally to be in equilibrium with the arterial blood at the alveolar surface of the lung during regular (passive) breathing; this assumption may not be valid during continuous phonation. We therefore have analyzed breathing (inhalation/exhalation) patterns and end-expired radioactivity (/sup 133/Xe) during (1) speaking, (2) singing, and (3) humming of the national anthem, and also during (4) passive breathing. Statistically significant differences in breathing patterns were measured between a group of nonmusicians and two groups of musicians (singers) during the phonation tasks: The nonmusicians breathed more often (and more rapidly) and exhibited less variability in their breathing patterns than did the musicians. Notwithstanding these differences, the shapes of smoothed functions derived from the end-expired values were not influenced appreciably during phonation (except possibly during talking). The latter finding suggests that estimates of rCBF derived with these data should not be confounded seriously because of the continuous phonation.

  18. The effects of continuous phonation on 133xenon-inhalation air curves (of the kind used in deriving regional cerebral blood flow).

    PubMed

    Formby, C; Thomas, R G; Brown, W S; Halsey, J H

    1987-07-01

    Regional cerebral blood flow (rCBF) may be measured with inhalation techniques that use end-expired values of radioactivity to estimate the isotope concentration in arterial blood. These end-expired data are used as an input function in a mathematical equation to derive rCBF. End-expired air is assumed normally to be in equilibrium with the arterial blood at the alveolar surface of the lung during regular (passive) breathing; this assumption may not be valid during continuous phonation. We therefore have analyzed breathing (inhalation/exhalation) patterns and end-expired radioactivity (133Xe) during (1) speaking, (2) singing, and (3) humming of the national anthem, and also during (4) passive breathing. Statistically significant differences in breathing patterns were measured between a group of nonmusicians and two groups of musicians (singers) during the phonation tasks: The nonmusicians breathed more often (and more rapidly) and exhibited less variability in their breathing patterns than did the musicians. Notwithstanding these differences, the shapes of smoothed functions derived from the end-expired values were not influenced appreciably during phonation (except possibly during talking). The latter finding suggests that estimates of rCBF derived with these data should not be confounded seriously because of the continuous phonation. PMID:3620907

  19. Dynamic dose assessment by Large Eddy Simulation of the near-range atmospheric dispersion.

    PubMed

    Vervecken, Lieven; Camps, Johan; Meyers, Johan

    2015-03-01

    In order to improve the simulation of the near-range atmospheric dispersion of radionuclides, computational fluid dynamics is becoming increasingly popular. In the current study, Large-Eddy Simulation is used to examine the time-evolution of the turbulent dispersion of radioactive gases in the atmospheric boundary layer, and it is coupled to a gamma dose rate model that is based on the point-kernel method with buildup factors. In this way, the variability of radiological dose rate from cloud shine due to instantaneous turbulent mixing processes can be evaluated. The steady release in an open field of (41)Ar and (133)Xe for 4 different release heights is studied, thus covering radionuclides that decay with a high-energy gamma and a low-energy gamma, respectively. Based on these simulations, the variability of dose rates at ground level for different averaging times in the dose measurements is analyzed. It is observed that turbulent variability in the wind field can lead to dose estimates that are underestimated by up to a factor of four when conventional long-term measurements are used to estimate the dose from short-term exposures. PMID:25634888

  20. The haemodynamic effects of the thromboxane A2 receptor antagonist GR32191B during cardiopulmonary bypass in the dog.

    PubMed

    Mathie, R T; Fleming, J S; Barrow, S E; Arnold, J V; Brannan, J J; Becket, J M; Ritter, J M; Taylor, K M

    1995-11-01

    This study examined whether treatment with the specific thromboxane (TX) A2 receptor antagonist GR32191B would result in an improvement in peripheral haemodynamics during and after cardiopulmonary bypass (CPB) in anaesthetized dogs compared with animals given either saline (control) or aspirin. Following thoracotomy, heparinization and aortic cannulation, and 35 minutes before CPB, dogs received intravenously either GR32191B (15 micrograms/kg/min), saline (50 ml bolus) or aspirin (225 mg bolus) (n = 6 per group). Cardiac output (dye dilution), femoral artery blood flow (electromagnetic flowmeter), gastrocnemius muscle tissue perfusion (133Xe clearance), retinal blood flow (fluorescein angiography), and thromboxane biosynthesis (urinary excretion rates of TXB2 and the metabolite 2,3-dinor-TXB2) were measured before, during and after a standard 90 minute period of CPB at 2.4 l/min/m2 and 28 degrees C. The aspirin-treated group manifested an eightfold reduction in TXB2 excretion compared with controls, indicating a decrease in TXA2 biosynthesis. There were few haemodynamic differences between the groups, though the aspirin-treated group had better maintained muscle tissue perfusion post-CPB and significantly fewer retinal microcirculatory occlusions than GR32191B-treated animals. We conclude that specific TXA2 receptor antagonism provides no significant improvement in peripheral haemodynamics; rather aspirin provides a modest haemodynamic benefit. PMID:8747897

  1. 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.

  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. 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. PMID:24316684

  4. Radioxenon production through neutron irradiation of stable xenon gas

    SciTech Connect

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

    2009-12-01

    The Spectral Deconvolution Analysis Tool (SDAT) software was developed to improve counting statistics and detection limits for nuclear explosion radionuclide measurements. SDAT utilizes spectral deconvolution spectroscopy techniques and can analyze both β-γ coincidence spectra for radioxenon isotopes and high-resolution HPGe spectra from aerosol monitors. The deconvolution algorithm of the SDAT requires a library of β-γ coincidence spectra of individual radioxenon isotopes to determine isotopic ratios in a sample. In order to get experimentally produced spectra of the individual isotopes we have irradiated enriched samples of 130Xe, 132Xe, and 134Xe gas with a neutron beam from the TRIGA reactor at The University of Texas. The samples produced were counted in an Automated Radioxenon Sampler/Analyzer (ARSA) style β-γ coincidence detector. The spectra produced show that this method of radioxenon production yields samples with very high purity of the individual isotopes for 131mXe and 135Xe and a sample with a substantial 133mXe to 133Xe ratio.

  5. Production of Samples of Individual Radioxenon Isotopes Through Neutron Irradiation of Stable Xenon Gas

    SciTech Connect

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

    2008-09-23

    The Spectral Deconvolution Analysis Tool (SDAT) software was developed to improve counting statistics and detection limits for nuclear explosion radionuclide measurements. SDAT utilizes spectral deconvolution spectroscopy techniques and can analyze both β-γ coincidence spectra for radioxenon isotopes and high-resolution HPGe spectra from aerosol monitors. The deconvolution algorithm of the SDAT requires a library of β-γ coincidence spectra of individual radioxenon isotopes to determine isotopic ratios in a sample. In order to get experimentally produced spectra of the individual isotopes we have irradiated enriched samples of 130Xe, 132Xe, and 134Xe gas with a neutron beam from the TRIGA reactor at The University of Texas. The samples produced were counted in an Automated Radioxenon Sampler/Analyzer (ARSA) style β-γ coincidence detector. The spectra produced show that this method of radioxenon production yields samples with very high purity of the individual isotopes for 131mXe and 135Xe and a sample with a substantial 133mXe to 133Xe ratio.

  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. The effect of local cold application on intramuscular blood flow at rest and after running.

    PubMed

    Thorsson, O; Lilja, B; Ahlgren, L; Hemdal, B; Westlin, N

    1985-12-01

    Local blood flow was measured with 133Xe clearance technique in eight male distance runners, where one leg was cooled for 20 min by applying two "instant cold packs" on the quadriceps muscle. An initial cooling period after resting was followed by a second cooling period 10 min after running. Skin temperature was maximally reduced after 4.5 min of cooling, both at rest and after running, by 15 degrees C and 14.9 degrees C, respectively. During the first 5 min of cooling no reduction of blood flow was seen. After 10 min of cooling blood flow was significantly reduced in the cooled compared to the control leg by 49% (P less than 0.05) after resting and 34% (P less than 0.05) after running. A maximum reduction of blood flow by 66 and 69% (P less than 0.01), respectively, was seen 10 min after the cooling period. In the event of an acute injury, this delayed reaction of cryotherapy on intramuscular blood flow should be carefully considered. PMID:4079745

  8. Radionuclide evaluation of lung trauma.

    PubMed

    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. PMID:6226097

  9. 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).

  10. Estimation of Coronary Blood Flow by Washout of Diffusible Indicators

    PubMed Central

    Bassingthwaighte, James B.; Strandell, Tore; Donald, David E.

    2010-01-01

    In 13 canine hearts, 158 disappearance curves for 133Xe and antipyrine-125I, given by intra-arterial slug injection, were recorded at a wide range of perfusion rates. Flow rates (ml/100 g/min) calculated from these curves by a variety of methods were compared with measured flow rates (Fa) per weight of perfused tissue. Perfusion of isolated, supported hearts and of anterior descending coronary arteries in open-chest dogs provided similar data. The semilogarithmic slope of curves from apex or whole heart decreased with time, particularly at high flow rates. There was a small, consistent difference in shape between antipyrine and xenon curves, suggesting that radioactivity in fat contributed somewhat to this tailing. Estimation of flow rate from the steepest semilog slope yielded an average value of 1.1Fa for all rates; estimation from slope at 30% of peak radioactivity gave 0.9Fa. The curves were closely described by a two-exponential equation which gave flow estimates of 0.95Fa when collimation limited the observations to the heart apex, and lower values when the whole heart was observed. Peak height/area methods gave values of approximately 0.75Fa in spite of various compensations for the impossibility of recording the curve until radioactivity = 0. PMID:4874081

  11. 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.

  12. Advanced Imaging Modalities in the Detection of Cerebral Vasospasm

    PubMed Central

    Mills, Jena N.; Mehta, Vivek; Russin, Jonathan; Amar, Arun P.; Rajamohan, Anandh; Mack, William J.

    2013-01-01

    The pathophysiology of cerebral vasospasm following aneurysmal subarachnoid hemorrhage (SAH) is complex and is not entirely understood. Mechanistic insights have been gained through advances in the capabilities of diagnostic imaging. Core techniques have focused on the assessment of vessel caliber, tissue metabolism, and/or regional perfusion parameters. Advances in imaging have provided clinicians with a multifaceted approach to assist in the detection of cerebral vasospasm and the diagnosis of delayed ischemic neurologic deficits (DIND). However, a single test or algorithm with broad efficacy remains elusive. This paper examines both anatomical and physiological imaging modalities applicable to post-SAH vasospasm and offers a historical background. We consider cerebral blood flow velocities measured by Transcranial Doppler Ultrasonography (TCD). Structural imaging techniques, including catheter-based Digital Subtraction Angiography (DSA), CT Angiography (CTA), and MR Angiography (MRA), are reviewed. We examine physiologic assessment by PET, HMPAO SPECT, 133Xe Clearance, Xenon-Enhanced CT (Xe/CT), Perfusion CT (PCT), and Diffusion-Weighted/MR Perfusion Imaging. Comparative advantages and limitations are discussed. PMID:23476766

  13. Changes in the loco-regional cerebral blood flow (r.C.B.F.) during a simulation of weightlessness

    NASA Astrophysics Data System (ADS)

    Guell, A.; Dupui, Ph.; Barrere, M.; Fanjaud, G.; Bes, A.; Kotowskaia, A.

    Experiments of prolonged bedrest in antiorthostatic position are conducted in order to simulate cardio-circulatory modifications observed in weightlessness. Until now, no studies of r.C.B.F. have been effected in these conditions. Six young, healthy volunteers (average age 23.8) were placed in strict bedrest and in antiorthostatic position -4° for 7 days. The r.C.B.F. measurements were studied by 133Xe inhalation method using a 32 detectors system. Studies were made first in basal conditions, then between the 6th and 12th hr, and finally between the 72nd and the 78th hr after the beginning of the experiment. Three of the subjects received 0.450 mg of Clonidine daily during the experiment. In the subjects having taken no Clonidine, we observed a constant increase in r.C.B.F. (12, 17 and 16% respectively) in the first 12 hr; at the 72nd hour, all values had returned to basal state. This findings agrees with the well known notion of a rapid correction of hemodynamic disturbances observed in the first days of weightlessness. In the subjects treated with Clonidine, the increase of r.C.B.F. did not occur. Several mechanicsms of action are possible; the Clonidine affecting either the heart by inhibiting volemic atrial receptors, or the brain by direct vasoconstriction.

  14. Clinical experience with technetium-99m DTPA aerosol with perfusion scintigraphy in suspected pulmonary embolism

    SciTech Connect

    Selby, J.B.; Gardner, J.J.

    1987-01-01

    To evaluate the clinical value of radioaerosol imaging, 156 patients with suspected pulmonary embolism (PE) were studied. In 25 patients, a preperfusion xenon-133 (Xe-133) study was compared with a postperfusion study using Tc-99m DTPA aerosol. It was found that they were of equal value most of the time (56%), but that the aerosol study was more often helpful. Because of this, and the technical ease of using six standard views with radioaerosol, the series was completed using perfusion scintigraphy followed by radioaerosol images. In 19 patients the perfusion scintigraphy with Tc-99 macroaggregated albumin (Tc-99m MAA) was normal or nearly normal and no aerosol study was required. Tc-99m DTPA aerosol images were satisfactory when the count rate was at least twice and preferably three times that of the previous perfusion study. There were 17 studies (11%) classified as intermediate. There were 26 patients classified as high probability for PE, and angiographic or autopsy correlation was available in 14. All of the 14 proved to have PE. In the 113 patients classified as low probability, there were ten with angiographic or autopsy correlation. In the ten, there was one patient with a small pulmonary embolus found at autopsy. Clinical follow-up for over two months confirmed the absence of PE in the remainder of this group. Aerosol studies have proven technically easier to perform and a satisfactory substitute for xenon imaging in suspected PE.

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. Monte Carlo simulation of a PhosWatch detector using Geant4 for xenon isotope beta-gamma coincidence spectrum profile and detection efficiency calculations.

    PubMed

    Mekarski, P; Zhang, W; Ungar, K; Bean, M; Korpach, E

    2009-10-01

    A simulation tool has been developed using the Geant4 Toolkit to simulate a PhosWatch single channel beta-gamma coincidence detection system consisting of a CsI(Tl)/BC404 Phoswich well detector and pulse shape analysis algorithms implemented digital signal processor. The tool can be used to simulate the detector's response for all the gamma rays and beta particles emitted from (135)Xe, (133m)Xe, (133)Xe, (131m)Xe and (214)Pb. Two- and three-dimensional beta-gamma coincidence spectra from the PhosWatch detector can be produced using the simulation tool. The accurately simulated spectra could be used to calculate system coincidence detection efficiency for each xenon isotope, the corrections for the interference from the various spectral components from radon and xenon isotopes, and system gain calibration. Also, it can generate two- and three-dimensional xenon reference spectra to test beta-gamma coincidence spectral deconvolution analysis software. PMID:19647444

  20. Near infrared spectroscopy--investigations in neurovascular diseases.

    PubMed

    Schytz, Henrik Winther

    2015-12-01

    The purpose of this thesis was to explore and develop methods, where continuous wave near infrared spectroscopy (CW-NIRS) can be applied in different neurovascular diseases, in order to find biological markers that are useful in clinical neurology. To develop a new method to detect changes in cerebral blood flow (CBF), the first study investigated a multi-source detector separation configuration and indocyanine green (ICG) as a tracer to calculate a corrected blood flow index (BFI) value. The study showed no correlation between CBF changes measured by 133Xenon single photon emission computer tomography (133Xe-SPECT) and the corrected BFI value. It was concluded, that it was not possible to obtain reliable BFI data with the ICG CW-NIRS method. NIRS measurements of low frequency oscillations (LFOs) may be a reliable method to investigate vascular alterations in neurovascular diseases, but this requires an acceptable LFOs variation between hemispheres and over time in the healthy brain. The second study therefore investigated day-to-day and hemispheric variations in LFOs with NIRS. It was shown that NIRS might be useful in assessing LFOs between hemispheres, as well as interhemispheric phase and gain directly and over time. Migraine may be associated with persistent impairment of neurovascular coupling, but there is no experimental evidence to support this. The third study therefore investigated interictal neurovascular coupling during a mental task by a Stroop test in migraine without aura (MO) patients, which is the most common type of migraine. The study showed intact neurovascular coupling in the prefrontal cortex outside of attacks in patients with MO. The fourth study aimed to investigate possible changes in LFOs amplitude following nitric oxide (NO) donor infusion in familial hemiplegic migraine (FHM), which is a rare Mendelian subtype of migraine with aura. This study showed increased LFOs amplitude only in FHM patients with co-existing common type of migraine

  1. 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

  2. An assessment on the PTS global radionuclide monitoring capabilities to detect the atmospheric traces of nuclear explosions

    NASA Astrophysics Data System (ADS)

    Becker, Andreas; Wotawa, Gerhard; Auer, Matthias; Krysta, Monika

    2010-05-01

    In order to detect any kind of nuclear explosion world-wide the Provisional Technical Secretariat to the Comprehensive Nuclear-Test-Ban Treaty (CTBT) is building up a verification regime that performs global monitoring for typical signals expected from such an event. Backbone of this regime is the 321 facilities International Monitoring System (IMS) comprising 80 stations to monitor for particulate radionuclides known to be fission or activation products of a nuclear explosion. Every second station is also equipped with a system capable to monitor for the occurrence of the CTBT relevant isotopes Xe-131m, Xe-133, Xe-133m, and Xe-135, which have the highest post-explosion fission yields among the noble gases, and are also not subject to wet deposition in the atmosphere. Moreover, they have a good chance to escape from the cavity of an underground nuclear explosion in contrast to the particulates. Effective radionuclide monitoring requires an optimum overall probability of a one-station detection of an atmospheric or underground nuclear explosion within 14 days. Consequently, the distribution of this detection probability is crucial for assessing the capacity of the radionuclide IMS to meet this requirement. The CTBT monitoring capabilities of the RN IMS are quite different in dependence on the environment in which the nuclear test is conducted (underground, underwater or atmospheric) as this determines the first crucial factor for the overall detection probability, the degree of containment. Secondly, the detection probability is subject to the nuclide specific decay and the dilution of any release (containment failure) during its atmospheric dispersion from the release location to one of the IMS stations. Thirdly, the detection limits of the measurement systems in use factor in. In the study presented here the radionuclide monitoring capabilities for detecting atmospheric and underground explosions, the latter mimicked by a 90% contained atmospheric release (first

  3. A single subcutaneous bolus of erythropoietin normalizes cerebral blood flow autoregulation after subarachnoid haemorrhage in rats

    PubMed Central

    Springborg, Jacob Bertram; Ma, XiaoDong; Rochat, Per; Knudsen, Gitte Moos; Amtorp, Ole; Paulson, Olaf B; Juhler, Marianne; Olsen, Niels Vidiendal

    2002-01-01

    Systemic administration of recombinant erythropoietin (EPO) has been demonstrated to mediate neuroprotection. This effect of EPO may in part rely on a beneficial effect on cerebrovascular dysfunction leading to ischaemic neuronal damage. We investigated the in vivo effects of subcutaneously administered recombinant EPO on impaired cerebral blood flow (CBF) autoregulation after experimental subarachnoid haemorrhage (SAH).Four groups of male Sprague-Dawley rats were studied: group A, sham operation plus vehicle; group B, sham operation plus EPO; group C, SAH plus vehicle; group D, SAH plus EPO. SAH was induced by injection of 0.07 ml of autologous blood into the cisterna magna. EPO (400 iu kg−1 s.c.) or vehicle was given immediately after the subarachnoid injection of blood or saline. Forty-eight hours after the induction of SAH, CBF autoregulatory function was evaluated using the intracarotid 133Xe method.CBF autoregulation was preserved in both sham-operated groups (lower limits of mean arterial blood pressure: 91±3 and 98±3 mmHg in groups A and B, respectively). In the vehicle treated SAH-group, autoregulation was abolished and the relationship between CBF and blood pressure was best described by a single linear regression line. A subcutaneous injection of EPO given immediately after the induction of SAH normalized autoregulation of CBF (lower limit in group D: 93±4 mmHg, NS compared with groups A and B).Early activation of endothelial EPO receptors may represent a potential therapeutic strategy in the treatment of cerebrovascular perturbations after SAH. PMID:11834631

  4. 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

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. 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

  12. Reciprocal Influence of Salt Intake on Adrenal Glomerulosa and Renal Vascular Responses to Angiotensin II in Normal Man

    PubMed Central

    Hollenberg, Norman K.; Chenitz, William R.; Adams, Douglass F.; Williams, Gordon H.

    1974-01-01

    The adrenal glomerulosa cell and the renal vasculature respond to similar arterial angiotensin II (A II) levels. We have assessed the effect of decreased sodium intake on their responses to A II in man. Studies were performed in 42 normal subjects in balance on a daily intake of 100 meq potassium and either 200 or 10 meq sodium/day. Renal blood flow was measured with 133Xe and arterial A II, renin and aldosterone concentrations by radioimmunoassay. A II was infused intravenously (1, 3, or 10 ng/kg/min) for 40—60 min; 14 subjects received graded doses. The A II level increased linearly with dose and plateaued within 3 min; blood pressure and renal vascular resistance showed a similar time-course. Aldosterone rose within 10 and plateaued within 20 min. Dose-response relationships were established between the rate of A II infusion and the adrenal, the renal vascular, and pressor responses. Sodium restriction reduced the pressor (P < 0.01) and the renal vascular response (P < 0.01), but potentiated the adrenal response to A II (P < 0.01). An excellent correlation was found between the plasma A II and aldosterone levels, but the slope of their regression relationship on a high (y = 0.13x + 6) and low salt intake (y = 0.32x + 14) differed significantly (P < 0.0005). Thus, sodium intake reciprocally influences vascular and adrenal responses to A II: salt restriction blunts the vascular response and potentiates the adrenal's, a physiologically important influence in view of aldosterone's role in sodium conservation. PMID:4365595

  13. 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.

  14. 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.

  15. Blood flow and oxygenation in peritendinous tissue and calf muscle during dynamic exercise in humans

    PubMed Central

    Boushel, Robert; Langberg, Henning; Green, Simon; Skovgaard, Dorthe; Bülow, Jens; Kjær, Michael

    2000-01-01

    Circulation around tendons may act as a shunt for muscle during exercise. The perfusion and oxygenation of Achilles' peritendinous tissue was measured in parallel with that of calf muscle during exercise to determine (1) whether blood flow is restricted in peritendinous tissue during exercise, and (2) whether blood flow is coupled to oxidative metabolism. Seven individuals performed dynamic plantar flexion from 1 to 9 W. Radial artery and popliteal venous blood were sampled for O2, peritendinous blood flow was determined by 133Xe-washout, calf blood flow by plethysmography, cardiac output by dye dilution, arterial pressure by an arterial catheter-transducer, and muscle and peritendinous O2 saturation by spatially resolved spectroscopy (SRS). Calf blood flow rose 20-fold with exercise, reaching 44 ± 7 ml (100 g)−1 min−1 (mean ± s.e.m.) at 9 W, while Achilles' peritendinous flow increased (7-fold) to 14 ± 4 ml (100 g)−1 min−1, which was 18 % of the maximal flow established during reactive hyperaemia. SRS-O2 saturation fell both in muscle (from 66 ± 2 % at rest to 57 ± 3 %, P < 0.05) and in peritendinous regions (58 ± 4 to 52 ± 4 %, P < 0.05) during exercise along with a rise in leg vascular conductance and microvascular haemoglobin volume, despite elevated systemic vascular resistance. The parallel rise in calf muscle and peritendinous blood flow and fall in O2 saturation during exercise indicate that blood flow is coupled to oxidative metabolism in both tissue regions. Increased leg vascular conductance accompanied by elevated microvascular haemoglobin volume reflect vasodilatation in both muscle and peritendinous regions. However, peak exercise peritendinous blood flow reaches only ≈20 % of its maximal blood flow capacity. PMID:10747200

  16. 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.

  17. Ability of chest radiography to predict widespread scintigraphic ventilation abnormalities in patients with suspected pulmonary embolism (PE)

    SciTech Connect

    Smith, R.; Ellis, K.; Alderson, P.O.

    1984-01-01

    The false negative rate of ventilation-perfusion (V-P) scintigraphy for PE increases in the presence of widespread obstructive pulmonary disease (OPD) because diffuse V abnormalities conceal potential V-P mismatches. To determine whether this situation could be predicted accurately by a pre-scintigraphy chest x-ray (CXR), a double-blind evaluation of 55 CXRs and V-P scans in 53 patients (pts) was performed. Multiview Kr-81m (Kr) scans were done in 38 cases and pre-perfusion Xe-133 (Xe) studies including washout in 17. All CXRs were obtained within 24 hrs of the scans and none showed infiltrates that would otherwise render the V-P scan nondiagnostic (NDX). All V-P scans showing V abnormalities in greater than or equal to67% of the lung fields were considered NDX, and those showing V abnormalities in 50-67% of the lungs were considered ''borderline'' for interpretation. CXRs were classified as showing diffuse OPD, focal OPD, or as no evidence for OPD. All V and all P scans were abnormal; 7 cases were read as high probability for PE, 29 as low probability and the remainder as NDX. Eleven of 13 (85%) pts with diffuse OPD by CXR had NDX scans (8/9 Kr, 3/4 Xe) and two were considered borderline. However, none of 10 pts with focal OPD by CXR had NDX scans and only 2 were considered borderline. The CXR showed no OPD in 32 cases, but 8 (25%) had enough V abnormalities to be classified NDX (2 of 21 Kr scans, 6 0f 11 Xe scans) and 2 others (both Kr scans) were considered borderline. The findings confirm that V scintigraphy with either Kr or Xe is more sensitive than the CXR in detecting airways disease, but indicate that V-P scintigraphy is likely to be NDX for PE in pts whose CXRs demonstrate diffuse OPD.

  18. 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.

  19. Regional pulmonary blood flow in mitral disease studied by xenon radiospirometry.

    PubMed Central

    Anderson, L H; Johansen, J K; Hyldebrandt, N

    1976-01-01

    Regional lung perfusion was measured in the sitting position by 4 external detectors after intravenous injection of 133Xe in 24 patients with mitral valve disease and in 8 people with no cardiopulmonary disease acting as normal controls. Right- and left-sided heart catheterization was carried out on the patients on the following day. Mitral valve stenosis was found in 9, mitral valve regurgitation in 8, and both stenosis and regurgitation in the remaining 7. Regional lung perfusion in the normal people fell linearly from the basal to the apical sections of the lungs. The perfusion distribution in patients with mitral valve disease and a pulmonary capillary vein (PCV) pressure lower than 15 mmHg (2-0 kPa) did not differ significantly from that of the controls. A redistribution of the regional perfusion, with an increase in the apical perfusion and a fall in the basal perfusion of the lungs, was seen in patients with a raised PCV pressure. The hyperperfusion of the apical lung sections correlated with the mean pressure in the pulmonary artery (r=+0-795, P less than 0-001), while the basal hypoperfusion correlated with the PCV pressure (r=0-842, P less than 0-001). The PCV pressure can be predicted with an exactitude of +/- 7 mmHg (0-9 kPa) (95% confidence limits). Neither the cardiac index nor the pulmonary vascular resistance correlated with the changes in perfusion. Xenon radiospirometry is a rapid and reliable method for evaluating PCV pressure before or after operation in patients with mitral valve disease. PMID:1275987

  20. Comparison of Tc-99m DTPA aerosol with radioactive gas ventilation imaging in patients (pts) with suspected pulmonary embolism (PE)

    SciTech Connect

    Alderson, P.O.; Kroop, S.A.; Biello, D.R.; Siegel, B.A.; Gottschalk, A.; Hoffer, P.B.; Ramanna, L.; Waxman, A.D.

    1984-01-01

    The utility of Tc-99m labeled DTPA aerosol (A) as a ventilation agent was compared to that of Xe-133 (Xe) or Kr-81m (Kr) gases in a series of 100 pts (age range 20-83, 53% women) undergoing ventilation-perfusion (V-P) imaging for suspected PE. The majority of pts had A and Xe studies in conjunction with P scans; 26 had A and Kr studies. All A studies were comprised of multiple 100K ct views performed prior to P scanning. Conventional Xe or Kr studies were then performed in conjunction with a multiview P scan. The studies were later reviewed by four independent readers who evaluated 100 V-P studies (100 A-P pairs, 100 gas-P pairs) and the accompanying chest radiographs and determined the probability of PE as none, low, high, or nondiagnostic (NDX). The A scans showed central hot spots in 27% of pts, but poor peripheral penetration in only 5%. Prominent lower lobe deposition was seen in 19 of the 66 pts who inhaled A upright, but in none who inhaled in the supine position. The A-P and gas-P scans were either both diagnostic or both NDX 82% of the time. There were 77% agreement between probability categories for A-P and Kr-P studies, and 74% agreement with Xe-P. These results were better than the inter-observer agreement for gas-P studies alone. Angiography revealed that 3 A-P studies were true negatives, 3 were true positives (pos), and one was a false pos (also pos by gas-P). The results suggest that commercially available DTPA aerosols provide comparable results to gas-P studies in pts with suspected PE.

  1. 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.

  2. 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.

  3. The effect of PCO2 on hypoxic pulmonary vasoconstriction.

    PubMed

    Noble, W H; Kay, J C; Fisher, J A

    1981-09-01

    Lung areas with a low V/Q ratio cause hypoxaemia. The low alveolar oxygen concentration may cause local hypoxic pulmonary vasoconstriction (HPV) which reduces perfusion, raises the V/Q ratio, and hence reduces the tendency to a low PaO2. By changing PCO2, the HPV response can be altered. We examined this relationship in anaesthetized dogs by using a tracheal divider to separate hypoxic (nitrogen ventilated) from oxygenated (100 per cent oxygen ventilated) lung. Relative perfusion was assessed from total 133Xe exhaled from each lung area after intravenous infusions. When PaCO2 was changed by changing ventilation, we found that an increasing PaCO2 increased HPV and also PaO2. At a PaCO2 of 3.3 kPa, HPV was abolished and PaO2 fell. We also changed PaCO2 by altering PICO2 to one or both lung areas while ventilation remained constant throughout the experiment. Again as PaCO2 increased, HPV and PaCO2 increased. When PaCO2 fell and end tidal carbon dioxide in the hypoxic lung (PETCO2) remained elevated by maintaining PICO2 in the hypoxic lung and removing CO2 from the oxygenated lung) HPV was maintained. Thus it is the alveolar concentration of CO2 in the hypoxic lung which is important in modifying HPV. We conclude that in this model a low PETCO2 (3.3 kPa) in hypoxic lung will reduce HPV, and will result in more severe hypoxaemia. This may have relevance in both anaesthetized and intensive care unit patients when a higher PaO2 may be obtained by increasing hypoxic lung PETCO2. The effect of PETCO2 on PaO2 will be influenced by other variables, but when hypoventilated or hypoxic exist, increasing PETCO2 may reinforce hypoxic pulmonary vasoconstriction and thus may increase PaO2. PMID:6793220

  4. 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.

  5. The Development of the improved equipment for the measurement radionuclides of xenon in atmospheric air

    NASA Astrophysics Data System (ADS)

    Pakhomov, S. A.; Dubasov, Y. V.

    2009-04-01

    surely define Xe volumetric concentration of 0.05% in β-cell, that is equivalent less then 0,5 cm3 of Xe. The first approbation of described equipment was fulfilled in St. Petersburg at autumn of 2007 year and have shown that the spectrometer allows to measure 133Xe concentration at the level of 2 mBq/m3, and this value is in a good agreement with the results of other measurements. Described equipment was practically approbated in field conditions on 2008 year during the expeditionary work carryout in Sosnovyi Bor, Udomlya and Polyarnie Zori - the cities of North-West of Russia, which are located in close neighboring with acting NPP.

  6. 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.

  7. 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).

  8. 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

  9. 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

  10. Cardiovascular and neurohumoral postural responses and baroreceptor abnormalities during a course of adjunctive vasodilator therapy with felodipine for congestive heart failure.

    PubMed

    Kassis, E; Amtorp, O

    1987-06-01

    Studies in patients with congestive heart failure (CHF) have demonstrated an abnormal beta-adrenergic reflex vasodilation during orthostatic tilt. Baroreflex modulation of vascular resistance in patients with CHF was investigated during therapy with a vasoselective calcium antagonist, felodipine. Eight patients on conventional therapy for severe CHF were studied after a 3 week course of additional felodipine or placebo treatment under randomized, double-blind, and crossover conditions. Forearm subcutaneous vascular resistance (FSVR) was estimated with use of the local 133Xe washout. Aortic pulsatile stretch, expressed as the systolic distension in percent of diastolic diameter, was calculated from echocardiographic measurements of aortic root diameters. At 3 weeks, felodipine reduced the arterial pressure, systemic vascular resistance, and FSVR, preserved cardiac filling pressures and heart rate, and increased cardiac output, stroke volume, and aortic pulsatile stretch. Upright tilt (45 degrees) was used to study baroreflex-mediated cardiovascular responses. The unloading of cardiopulmonary baroreceptors during upright tilt was substantial and about equal during both treatment courses, but the pulse pressure was maintained during the placebo and decreased during the felodipine period. During tilt, the patients on placebo failed to increase heart rate and their FSVR, systemic vascular resistance, and arterial mean pressure were decreased, whereas during tilt after felodipine, heart rate and systemic vascular resistance increased to maintain arterial mean pressure and FSVR also tended to increase. Both the stroke volume and aortic pulsatile stretch increased during tilt in patients on placebo but they decreased in those on felodipine. The tilt caused increments in circulating norepinephrine and epinephrine levels during both treatment regimens. Regulation of FSVR during the sympathetic stimulation of orthostatic stress was further elucidated. Proximal neural blockade

  11. Impairment of bronchial mucociliary clearance in long-term survivors of heart/lung and double-lung transplantation. The Paris-Sud Lung Transplant Group.

    PubMed

    Herve, P; Silbert, D; Cerrina, J; Simonneau, G; Dartevelle, P

    1993-01-01

    The study objective was to investigate bronchial mucociliary clearance after heart/lung and double lung transplantation. Bronchial mucociliary clearance was measured using a noninvasive radioaerosol technique: 99mTc-labeled albumin was aerosolized using a spinning-top generator (mass median aerodynamic diameter, 7.5 mu; geometric standard deviation, 1.5 mu). Radioactivity counts were acquired during 60 min with a gamma camera. A region of interest was drawn over the right lung delineated by a 133Xe lung ventilation image. Bronchial mucociliary clearance was assessed as the percentage of decrease in radioactivity per hour calculated on time-activity curves fitted by a monoexponential model. To exclude patients with acute lung rejection, opportunistic lung infection, and obliterative bronchiolitis, all patients with transplants underwent pulmonary function tests and bronchoscopic examination before clearance measurement. Eight heart/lung and five double-lung nonsmoking transplant patients with normal lung histology were studied 19.3 +/- 4.0 mo after surgery and compared to nine normal nonsmokers. A similar proximal deposition of the aerosol was obtained in patients with transplants and normal subjects; skew values of distribution histograms of aerosol radioactivity counts were 2.1 +/- 0.2 and 1.8 +/- 0.1, respectively, and the ratios between central and peripheral 99mTc radioactivity counts were 2.4 +/- 0.1 and 2.3 +/- 0.2, respectively. No significant difference was observed in bronchial clearance values between patients with heart/lung and double-lung transplants (26.4 +/- 3.0 percent/h vs 35.9 +/- 3.5 percent/h). Conversely, bronchial clearance was significantly lower in transplant recipients (30.0 +/- 2.5 percent/h) than in normal controls (58.7 +/- 6.2 percent/h; p < 0.001). This decreased bronchial clearance can be expected to increase the risk of lung infection in long-term survivors of heart/lung and double-lung transplantation. PMID:8380268

  12. Regional Myocardial Perfusion Rates in Patients with Coronary Artery Disease

    PubMed Central

    Cannon, Paul J.; Dell, Ralph B.; Dwyer, Edward M.

    1972-01-01

    Regional myocardial perfusion rates were estimated from the myocardial washout of 133Xenon in 24 patients with heart disease whose coronary arteriograms were abnormal and 17 similar subjects whose coronary arteriograms were judged to be normal. Disappearance rates of 133Xe from multiple areas of the heart were monitored externally with a multiple-crystal scintillation camera after the isotope had been injected into a coronary artery and local myocardial perfusion rates were calculated by the Kety formula. The mean myocardial perfusion rates in the left ventricle exceeded those in the right ventricle or atrial regions in subjects without demonstrable coronary artery disease. In this group there was a significant lack of homogeneity of local perfusion rates in left ventricular myocardium; the mean coefficient of variation of left ventricular local perfusion rates was 15.8%. In the patients with radiographically demonstrable coronary artery disease, a variety of myocardial perfusion patterns were observed. Local capillary blood flow rates were depressed throughout the myocardium of patients with diffuse coronary disease but were subnormal only in discrete myocardial regions of others with localized occlusive disease. Local myocardial perfusion rates were similar to those found in the group with normal coronary arteriograms in patients with slight degrees of coronary disease and in those areas of myocardium distal to marked coronary constrictions or occlusions which were well supplied by collateral vessels. In subjects with right coronary disease, the mean right ventricular perfusion rates were significantly subnormal; in seven subjects of this group perfusion of the inferior left ventricle by a dominant right coronary artery was absent or depressed. The average mean left ventricular perfusion rate of 12 subjects with significant disease of two or more branches of the left coronary artery was significantly lower than that of the group with normal left coronary

  13. Barium and xenon isotope yields in photopion reactions of sup 133 Cs

    SciTech Connect

    Sakamoto, K.; Hamajima, Y.; Soto, M.; Kubota, Y.; Yoshida, M.; Kunugise, A.; Masatani, M. ); Shibata, S.; Imamura, M. ); Furukawa, M. ); Fujiwara, I. )

    1990-10-01

    Radiochemical yield measurements are reported for barium isotopes from {sup 133}Cs({gamma},{pi}{sup {minus}}{ital xn}){sup 133{minus}{ital x}}Ba for {ital x}=0, 2, 4, 5, 6, 7, and 9 for bremsstrahlung maximum end-point energies {ital E}{sub 0}=30--1050 MeV and for {sup 133}Xe from {sup 133}Cs({gamma},{pi}{sup +}){sup 133{ital m},{ital g}}Xe for {ital E}{sub 0}=300--1000 MeV. Emphasis was placed on Ba measurements near the pion threshold and for different target thicknesses in order to assess interfering secondary particle-induced reactions. Clear evidence of secondary reactions was found in the form of a shoulder in the yield curves for a range of values near {ital E}{sub 0}{approx lt}{ital Q}{sub {pi}{sup {minus}}}, the {ital Q}{sub {pi}{sup {minus}}} value of {sup 133}Cs({gamma},{pi}{sup {minus}}{ital xn}) reaction. This result was used for the correction of yields at {ital E}{sub 0}{approx gt}{ital Q}{sub {pi}{sup {minus}}} with the aid of reported measurements of photoproton spectra from {sup 12}C and other complex nuclei and cross sections of ({sup 133}Cs+{ital p}) reactions. The yields corrected for the secondaries {sigma}{sub {ital q}}({ital E}{sub 0}) were unfolded into cross sections per photon of energy {ital k}, {sigma}({ital k}). The characteristic features of {sigma}{sub {ital q}}({ital E}{sub 0}) and {sigma}({ital k}) are then discussed in terms of {ital E}{sub 0} and {ital k} dependences and product mass ({ital A}{sub {ital p}}=133{minus}{ital x}) by comparing the present results with those for other systems currently obtained by our group. It was found that the present results of {sigma}({ital k}) are generally reproduced by a cascade-evaporation calculation based on the PICA code of Gabriel and Alsmiller, only if the calculated values are shifted up in photon energy by 30 MeV and the neutron cutoff energy is chosen to be 1 MeV.

  14. 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

  15. Interpreting aerosol lifetimes using the GEOS-Chem model and constraints from radionuclide measurements

    NASA Astrophysics Data System (ADS)

    Croft, B.; Pierce, J. R.; Martin, R. V.

    2013-12-01

    Aerosol removal processes control global aerosol abundance, but the rate of that removal remains uncertain. A recent study of aerosol-bound radionuclide measurements after the Fukushima Dai-Ichi nuclear power plant accident documents 137Cs removal (e-folding) times of 10.0 to 13.9 days, suggesting that mean aerosol lifetimes in the range of 3-7 days in global models might be too short by a factor of two. In this study, we attribute this discrepancy to differences between the e-folding and mean aerosol lifetimes. We implement a~simulation of 137Cs and 133Xe into the GEOS-Chem chemical transport model and examine the removal rates for the Fukushima case. We find a~general consistency between modelled and measured e-folding times. The simulated 137Cs global burden e-folding time is about 14 days. However, the simulated mean lifetime of aerosol-bound 137Cs over a 6 month post-accident period is only 1.8 days. We find that the mean lifetime depends strongly on the removal rates in the first few days after emissions, before the aerosols leave the boundary layer and are transported to altitudes and latitudes where lifetimes with respect to wet removal are longer by a few orders of magnitude. We present sensitivity simulations that demonstrate the influence of differences in altitude and location of the radionuclides on the mean lifetime. Global mean lifetimes are shown to strongly depend on the altitude of injection. The global mean 137Cs lifetime is more than one order of magnitude greater for the injection at 7 km than into the boundary layer above the Fukushima site. Instantaneous removal rates are slower during the first few days after the emissions for a free tropospheric vs. boundary layer injection and this strongly controls the mean lifetimes. Global mean aerosol lifetimes for the GEOS-Chem model are 3-6 days, which is longer than for the 137Cs injected at the Fukushima site (likely due to precipitation shortly after Fukushima emissions), but about the same as the

  16. Interpreting aerosol lifetimes using the GEOS-Chem model and constraints from radionuclide measurements

    NASA Astrophysics Data System (ADS)

    Croft, B.; Pierce, J. R.; Martin, R. V.

    2014-04-01

    Aerosol removal processes control global aerosol abundance, but the rate of that removal remains uncertain. A recent study of aerosol-bound radionuclide measurements after the Fukushima Daiichi nuclear power plant accident documents 137Cs removal (e-folding) times of 10.0-13.9 days, suggesting that mean aerosol lifetimes in the range of 3-7 days in global models might be too short by a factor of two. In this study, we attribute this discrepancy to differences between the e-folding and mean aerosol lifetimes. We implement a simulation of 137Cs and 133Xe into the GEOS-Chem chemical transport model and examine the removal rates for the Fukushima case. We find a general consistency between modelled and measured e-folding times. The simulated 137Cs global burden e-folding time is about 14 days. However, the simulated mean lifetime of aerosol-bound 137Cs over a 6-month post-accident period is only 1.8 days. We find that the mean lifetime depends strongly on the removal rates in the first few days after emissions, before the aerosols leave the boundary layer and are transported to altitudes and latitudes where lifetimes with respect to wet removal are longer by a few orders of magnitude. We present sensitivity simulations that demonstrate the influence of differences in altitude and location of the radionuclides on the mean lifetime. Global mean lifetimes are shown to strongly depend on the altitude of injection. The global mean 137Cs lifetime is more than one order of magnitude greater for the injection at 7 km than into the boundary layer above the Fukushima site. Instantaneous removal rates are slower during the first few days after the emissions for a free tropospheric versus boundary layer injection and this strongly controls the mean lifetimes. Global mean aerosol lifetimes for the GEOS-Chem model are 3-6 days, which is longer than that for the 137Cs injected at the Fukushima site (likely due to precipitation shortly after Fukushima emissions), but similar to the

  17. 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

  18. 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.

  19. 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

  20. 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.