Planned Closeout of the Cf-252 Loan/Lease Program

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sherman, Steven R; Patton, Bradley D

2012-09-01

New funding is sought to pursue planned closeout of the Cf-252 Loan Program. The work will be performed in phases. In the initial phase, users will be surveyed to determine whether they wish to take ownership of sources in their possession, or return them. In the second phase, sources will be recalled from non-DOE entities, and source ownership transfers will be performed. In the third phase, the remaining sources from DOE entities will be recalled. Initial funding of $350K is sought to fund the first phase, and to plan execution of the remaining phases given information collected from user surveys.

A Monte Carlo simulation and setup optimization of output efficiency to PGNAA thermal neutron using 252Cf neutrons

NASA Astrophysics Data System (ADS)

Zhang, Jin-Zhao; Tuo, Xian-Guo

2014-07-01

We present the design and optimization of a prompt γ-ray neutron activation analysis (PGNAA) thermal neutron output setup based on Monte Carlo simulations using MCNP5 computer code. In these simulations, the moderator materials, reflective materials, and structure of the PGNAA 252Cf neutrons of thermal neutron output setup are optimized. The simulation results reveal that the thin layer paraffin and the thick layer of heavy water moderating effect work best for the 252Cf neutron spectrum. Our new design shows a significantly improved performance of the thermal neutron flux and flux rate, that are increased by 3.02 times and 3.27 times, respectively, compared with the conventional neutron source design.

SU-E-T-90: Accuracy of Calibration of Lithium-6 and -7 Enriched LiF TLDs for Neutron Measurements in High Energy Radiotherapy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Keehan, S; Franich, R; Taylor, M

Purpose: To determine the potential error involved in the interpretation of neutron measurements from medical linear accelerators (linacs) using TLD-600H and TLD-700H if standard AmBe and {sup 252}Cf neutron sources are used for calibration without proper inclusion of neutron energy spectrum information. Methods: The Kerma due to neutrons can be calculated from the energy released by various nuclear interactions (elastic and inelastic scatter, (n,α), (n,p), (n,d), (n,t), (n,2n), etc.). The response of each TLD can be considered the sum of the neutron and gamma components; each proportional to the Kerma. Using the difference between the measured TLD responses and themore » ratio of the calculated Kerma for each material, the neutron component of the response can be calculated. The Monte Carlo code MCNP6 has been used to calculate the neutron energy spectra resulting from photonuclear interactions in a Varian 21EX linac. TLDs have been exposed to the mixed (γ-n) field produced by a linac and AmBe and {sup 252}Cf standard neutron sources. Results: For dosimetry of neutrons from AmBe or {sup 252}Cf sources, assuming TLD-700H insensitivity to neutrons will Result in 10% or 20% overestimation of neutron doses respectively.For dosimetry of neutrons produced in a Varian 21EX, applying a calibration factor derived from a standard AmBe or {sup 252}Cf source will Result in an overestimation of neutron fluence, by as much as a factor of 47.The assumption of TLD-700H insensitivity to neutrons produced by linacs leads to a negligible error due to the extremely high Kerma ratio (600H/700H) of 3000 for the assumed neutron spectrum. Conclusion: Lithium-enriched TLDs calibrated with AmBe and/or {sup 252}Cf neutron sources are not accurate for use under the neutron energy spectrum produced by a medical linear accelerator.« less

Localization and spectral isolation of special nuclear material using stochastic image reconstruction

NASA Astrophysics Data System (ADS)

Hamel, M. C.; Polack, J. K.; Poitrasson-Rivière, A.; Clarke, S. D.; Pozzi, S. A.

2017-01-01

In this work we present a technique for isolating the gamma-ray and neutron energy spectra from multiple radioactive sources localized in an image. Image reconstruction algorithms for radiation scatter cameras typically focus on improving image quality. However, with scatter cameras being developed for non-proliferation applications, there is a need for not only source localization but also source identification. This work outlines a modified stochastic origin ensembles algorithm that provides localized spectra for all pixels in the image. We demonstrated the technique by performing three experiments with a dual-particle imager that measured various gamma-ray and neutron sources simultaneously. We showed that we could isolate the peaks from 22Na and 137Cs and that the energy resolution is maintained in the isolated spectra. To evaluate the spectral isolation of neutrons, a 252Cf source and a PuBe source were measured simultaneously and the reconstruction showed that the isolated PuBe spectrum had a higher average energy and a greater fraction of neutrons at higher energies than the 252Cf. Finally, spectrum isolation was used for an experiment with weapons grade plutonium, 252Cf, and AmBe. The resulting neutron and gamma-ray spectra showed the expected characteristics that could then be used to identify the sources.

Isolation and Purification of the Xenon Fraction of 252Cf Spontaneous Fission Products for the Production of Radio Xenon Calibration Standards

DOE Office of Scientific and Technical Information (OSTI.GOV)

McGrath, Christopher A.

2015-04-01

The presence of radioactive xenon isotopes indicates that fission events have occurred, and is used to help enforce the Comprehensive Test Ban Treaty. Idaho National Laboratory (INL) produces 135Xe, 133mXe, 133Xe, and 131mXe standards used for the calibration and testing of collection equipment and analytical techniques used to monitor radio xenon emissions. At INL, xenon is produced and collected as one of several spontaneous fission products from a 252Cf source. Further chromatographic purification of the fission gases ensures the separations of the xenon fraction for selective collection. An explanation of the fission gas collection, separation and purification is presented. Additionally,more » the range of 135Xe to 133Xe ratio that can be isolated is explained. This is an operational update on the work introduced previously, now that it is in operation and has been recharged with a second 252Cf source.« less

Measurement of the ambient gamma dose equivalent and kerma from the small 252Cf source at 1 meter and the small 60Co source at 2 meters

DOE Office of Scientific and Technical Information (OSTI.GOV)

Carl, W. F.

NASA Langley Research Center requested a measurement and determination of the ambient gamma dose equivalent rate and kerma at 100 cm from the 252Cf source and determination of the ambient gamma dose equivalent rate and kerma at 200 cm from the 60Co source for the Radiation Budget Instrument Experiment (Rad-X). An Exradin A6 ion chamber with Shonka air-equivalent plastic walls in combination with a Supermax electrometer were used to measure the exposure rate and free-in-air kerma rate of the two sources at the requested distances. The measured gamma exposure, kerma, and dose equivalent rates are tabulated.

A new facility for non-destructive assay using a 252Cf source.

PubMed

Stevanato, L; Caldogno, M; Dima, R; Fabris, D; Hao, Xin; Lunardon, M; Moretto, S; Nebbia, G; Pesente, S; Pino, F; Sajo-Bohus, L; Viesti, G

2013-03-01

A new laboratory facility for non-destructive analysis (NDA) using a time-tagged (252)Cf source is presented. The system is designed to analyze samples having maximum size of about 20 × 25 cm(2), the material recognition being obtained by measuring simultaneously total and energy dependent transmission of neutrons and gamma rays. The equipment technical characteristics and performances of the NDA system are presented, exploring also limits due to the sample thickness. Some recent applications in the field of cultural heritage are presented. Copyright © 2012 Elsevier Ltd. All rights reserved.

Source detection at 100 meter standoff with a time-encoded imaging system

DOE Office of Scientific and Technical Information (OSTI.GOV)

Brennan, J.; Brubaker, E.; Gerling, M.

Here, we present the design, characterization, and testing of a laboratory prototype radiological search and localization system. The system, based on time-encoded imaging, uses the attenuation signature of neutrons in time, induced by the geometrical layout and motion of the system. We have demonstrated the ability to detect a ~1 mCi 252 Cf radiological source at 100 m standoff with 90% detection efficiency and 10% false positives against background in 12 min. As a result, this same detection efficiency is met at 15 s for a 40 m standoff, and 1.2 s for a 20 m standoff.

Source detection at 100 meter standoff with a time-encoded imaging system

DOE PAGES

Brennan, J.; Brubaker, E.; Gerling, M.; ...

2017-09-28

Here, we present the design, characterization, and testing of a laboratory prototype radiological search and localization system. The system, based on time-encoded imaging, uses the attenuation signature of neutrons in time, induced by the geometrical layout and motion of the system. We have demonstrated the ability to detect a ~1 mCi 252 Cf radiological source at 100 m standoff with 90% detection efficiency and 10% false positives against background in 12 min. As a result, this same detection efficiency is met at 15 s for a 40 m standoff, and 1.2 s for a 20 m standoff.

Exploiting Fission Chain Reaction Dynamics to Image Fissile Materials

NASA Astrophysics Data System (ADS)

Chapman, Peter Henry

Radiation imaging is one potential method to verify nuclear weapons dismantlement. The neutron coded aperture imager (NCAI), jointly developed by Oak Ridge National Laboratory (ORNL) and Sandia National Laboratories (SNL), is capable of imaging sources of fast (e.g., fission spectrum) neutrons using an array of organic scintillators. This work presents a method developed to discriminate between non-multiplying (i.e., non-fissile) neutron sources and multiplying (i.e., fissile) neutron sources using the NCAI. This method exploits the dynamics of fission chain-reactions; it applies time-correlated pulse-height (TCPH) analysis to identify neutrons in fission chain reactions. TCPH analyzes the neutron energy deposited in the organic scintillator vs. the apparent neutron time-of-flight. Energy deposition is estimated from light output, and time-of-flight is estimated from the time between the neutron interaction and the immediately preceding gamma interaction. Neutrons that deposit more energy than can be accounted for by their apparent time-of-flight are identified as fission chain-reaction neutrons, and the image is reconstructed using only these neutron detection events. This analysis was applied to measurements of weapons-grade plutonium (WGPu) metal and 252Cf performed at the Nevada National Security Site (NNSS) Device Assembly Facility (DAF) in July 2015. The results demonstrate it is possible to eliminate the non-fissile 252Cf source from the image while preserving the fissileWGPu source. TCPH analysis was also applied to additional scenes in which theWGPu and 252Cf sources were measured individually. The results of these separate measurements further demonstrate the ability to remove the non-fissile 252Cf source and retain the fissileWGPu source. Simulations performed using MCNPX-PoliMi indicate that in a one hour measurement, solid spheres ofWGPu are retained at a 1sigma level for neutron multiplications M -˜ 3.0 and above, while hollowWGPu spheres are retained for M -˜ 2.7 and above.

The D-D Neutron Generator as an Alternative to Am(Li) Isotopic Neutron Source in the Active Well Coincidence Counter

DOE Office of Scientific and Technical Information (OSTI.GOV)

McElroy, Robert Dennis; Cleveland, Steven L.

The 235U mass assay of bulk uranium items, such as oxide canisters, fuel pellets, and fuel assemblies, is not achievable by traditional gamma-ray assay techniques due to the limited penetration of the item by the characteristic 235U gamma rays. Instead, fast neutron interrogation methods such as active neutron coincidence counting must be used. For international safeguards applications, the most commonly used active neutron systems, the Active Well Coincidence Counter (AWCC), Uranium Neutron Collar (UNCL) and 252Cf Shuffler, rely on fast neutron interrogation using an isotopic neutron source [i.e., 252Cf or Am(Li)] to achieve better measurement accuracies than are possible usingmore » gamma-ray techniques for high-mass, high-density items. However, the Am(Li) sources required for the AWCC and UNCL systems are no longer manufactured, and newly produced systems rely on limited supplies of sources salvaged from disused instruments. The 252Cf shuffler systems rely on the use of high-output 252Cf sources, which while still available have become extremely costly for use in routine operations and require replacement every five to seven years. Lack of a suitable alternative neutron interrogation source would leave a potentially significant gap in the safeguarding of uranium processing facilities. In this work, we made use of Oak Ridge National Laboratory’s (ORNL’s) Large Volume Active Well Coincidence Counter (LV-AWCC) and a commercially available deuterium-deuterium (D-D) neutron generator to examine the potential of the D-D neutron generator as an alternative to the isotopic sources. We present the performance of the LV-AWCC with D-D generator for the assay of 235U based on the results of Monte Carlo N-Particle (MCNP) simulations and measurements of depleted uranium (DU), low enriched uranium (LEU), and highly enriched uranium (HEU) items.« less

Validation of IRDFF in 252Cf standard and IRDF-2002 reference neutron fields

DOE Office of Scientific and Technical Information (OSTI.GOV)

Simakov, Stanislav; Capote Noy, Roberto; Greenwood, Lawrence R.

The results of validation of the latest release of International Reactor Dosimetry and Fusion File, IRDFF-1.03, in the standard 252Cf(s.f.) and reference 235U(nth,f) neutron benchmark fields are presented. The spectrum-averaged cross sections were shown to confirm the recommended spectrum for 252Cf spontaneous fission source; that was not the case for the current recommended spectra for 235U(nth,f). IRDFF was also validated in the spectra of the research reactor facilities ISNF, Sigma-Sigma and YAYOI, which are available in the IRDF- 2002 collection. Before this analysis, the ISFN spectrum was resimulated to remove unphysical oscillations in spectrum. IRDFF-1.03 was shown to reasonably reproducemore » the spectrum-averaged data measured in these fields except for the case of YAYOI.« less

Replacing a 252Cf source with a neutron generator in a shuffler - a conceptual design performed with MCNPX

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schear, Melissa A; Tobin, Stephen J

2009-01-01

The {sup 252}Cf shuffler has been widely used in nuclear safeguards and radioactive waste management to assay fissile isotopes, such as {sup 235}U or {sup 239}Pu, present in a variety of samples, ranging from small cans of uranium waste to metal samples weighing several kilograms. Like other non-destructive assay instruments, the shuffler uses an interrogating neutron source to induce fissions in the sample. Although shufflers with {sup 252}Cf sources have been reliably used for several decades, replacing this isotopic source with a neutron generator presents some distinct advantages. Neutron generators can be run in a continuous or pulsed mode, andmore » may be turned off, eliminating the need for shielding and a shuffling mechanism in the shuffler. There is also essentially no dose to personnel during installation, and no reliance on the availability of {sup 252}Cf. Despite these advantages, the more energetic neutrons emitted from the neutron generator (141 MeV for D-T generators) present some challenges for certain material types. For example when the enrichment of a uranium sample is unknown, the fission of {sup 238}U is generally undesirable. Since measuring uranium is one of the main uses of a shuffler, reducing the delayed neutron contribution from {sup 238}U is desirable. Hence, the shuffler hardware must be modified to accommodate a moderator configuration near the source to tailor the interrogating spectrum in a manner which promotes sub-threshold fissions (below 1 MeV) but avoids the over-moderation of the interrogating neutrons so as to avoid self-shielding. In this study, where there are many material and geometry combinations, the Monte Carlo N-Particle eXtended (MCNPX) transport code was used to model, design, and optimize the moderator configuration within the shuffler geometry. The code is then used to evaluate and compare the assay performances of both the modified shuffler and the current {sup 252}Cf shuffler designs for different test samples. The matrix effect and the non-uniformity of the interrogating flux are investigated and quantified in each case. The modified geometry proposed by this study can serve s a guide in retrofitting shufflers that are already in use.« less

Moderator design studies for a new neutron reference source based on the D-T fusion reaction

NASA Astrophysics Data System (ADS)

Mozhayev, Andrey V.; Piper, Roman K.; Rathbone, Bruce A.; McDonald, Joseph C.

2016-06-01

The radioactive isotope Californium-252 (252Cf) is relied upon internationally as a neutron calibration source for ionizing radiation dosimetry because of its high specific activity. The source may be placed within a heavy-water (D2O) moderating sphere to produce a softened spectrum representative of neutron fields common to commercial nuclear power plant environments, among others. Due to termination of the U.S. Department of Energy loan/lease program in 2012, the expense of obtaining 252Cf sources has undergone a significant increase, rendering high output sources largely unattainable. On the other hand, the use of neutron generators in research and industry applications has increased dramatically in recent years. Neutron generators based on deuteriumtritium (D-T) fusion reaction provide high neutron fluence rates and, therefore, could possibly be used as a replacement for 252Cf. To be viable, the 14 MeV D-T output spectrum must be significantly moderated to approximate common workplace environments. This paper presents the results of an effort to select appropriate moderating materials and design a configuration to reshape the primary neutron field toward a spectrum approaching that from a nuclear power plant workplace. A series of Monte-Carlo (MCNP) simulations of single layer high- and low-Z materials are used to identify initial candidate moderators. Candidates are refined through a similar series of simulations involving combinations of 2-5 different materials. The simulated energy distribution using these candidate moderators are rated in comparison to a target spectrum. Other properties, such as fluence preservation and/or enhancement, prompt gamma production and other characteristics are also considered.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Meierbachtol, K.; Tovesson, F.; Shields, D.

We developed the SPectrometer for Ion DEtermination in fission Research (SPIDER) for measuring mass yield distributions of fission products from spontaneous and neutron-induced fission. The 2E–2v method of measuring the kinetic energy (E) and velocity (v) of both outgoing fission products has been utilized, with the goal of measuring the mass of the fission products with an average resolution of 1 atomic mass unit (amu). Moreover, the SPIDER instrument, consisting of detector components for time-of-flight, trajectory, and energy measurements, has been assembled and tested using 229Th and 252Cf radioactive decay sources. For commissioning, the fully assembled system measured fission productsmore » from spontaneous fission of 252Cf. Individual measurement resolutions were met for time-of-flight (250 ps FWHM), spacial resolution (2 mm FHWM), and energy (92 keV FWHM for 8.376 MeV). Finally, these mass yield results measured from 252Cf spontaneous fission products are reported from an E–v measurement.« less

Unfolding the prompt gamma ray spectra measured in a Lanthanum Bromide detector using GRAVEL method

NASA Astrophysics Data System (ADS)

De, S.; Thomas, R. G.; Rout, P. C.; Suryanarayana, S. V.; Nayak, B. K.; Saxena, A.

2018-02-01

Prompt fission Upsilon -ray energy spectra in spontaneous fission of 252Cf has been measured using a 6'' LaBr3(Ce) detector. Unfolding of the measured Upsilon -ray energy spectra has been carried out using GRAVEL method. The response matrix of the detector has been simulated using GEANT4 and the unfolding of Upsilon -ray energy spectra for 60Co and 137Cs sources have been validated. This unfolding technique has then been applied to the prompt gamma spectra obtained from the spontaneous fission of 252Cf.

Moderator design studies for a new neutron reference source based on the D–T fusion reaction

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mozhayev, Andrey V.; Piper, Roman K.; Rathbone, Bruce A.

2016-06-01

The radioactive isotope Californium-252 (252Cf) is relied upon internationally as a neutron calibration source for ionizing radiation dosimetry because of its high specific activity. The source may be placed within a heavy-water (D2O) moderating sphere to produce a softened spectrum representative of neutron fields common to commercial nuclear power plant environments, among others. Due to termination of the U.S. Department of Energy loan/lease program in 2012, the expense of obtaining 252Cf sources has undergone a significant increase, rendering high output sources largely unattainable. On the other hand, the use of neutron generators in research and industry applications has increased dramaticallymore » in recent years. Neutron generators based on deuterium-tritium (D-T) fusion reaction provide high neutron fluence rates and, therefore, could possibly be used as a replacement for 252Cf. To be viable, the 14.6 MeV D-T output spectrum must be significantly moderated to approximate common workplace environments. This paper presents the results of an effort to select appropriate moderating materials and design a configuration to reshape the primary neutron field toward a spectrum approaching that from a nuclear power plant workplace. A series of Monte-Carlo (MCNP) simulations of single layer high- and low-Z materials are used to identify initial candidate moderators. Candidates are refined through a similar series of simulations involving combinations of 2 to 5 different materials. The simulated energy distribution using these candidate moderators are rated in comparison to a target spectrum. Other properties, such as fluence preservation and/or enhancement, prompt gamma production and other characteristics are also considered.« less

The SPIDER fission fragment spectrometer for fission product yield measurements

DOE PAGES

Meierbachtol, K.; Tovesson, F.; Shields, D.; ...

2015-04-01

We developed the SPectrometer for Ion DEtermination in fission Research (SPIDER) for measuring mass yield distributions of fission products from spontaneous and neutron-induced fission. The 2E–2v method of measuring the kinetic energy (E) and velocity (v) of both outgoing fission products has been utilized, with the goal of measuring the mass of the fission products with an average resolution of 1 atomic mass unit (amu). Moreover, the SPIDER instrument, consisting of detector components for time-of-flight, trajectory, and energy measurements, has been assembled and tested using 229Th and 252Cf radioactive decay sources. For commissioning, the fully assembled system measured fission productsmore » from spontaneous fission of 252Cf. Individual measurement resolutions were met for time-of-flight (250 ps FWHM), spacial resolution (2 mm FHWM), and energy (92 keV FWHM for 8.376 MeV). Finally, these mass yield results measured from 252Cf spontaneous fission products are reported from an E–v measurement.« less

Upset due to a single particle caused propagated transients in a bulk CMOS microprocessor

DOE Office of Scientific and Technical Information (OSTI.GOV)

Leavy, J.F.; Hoffmann, L.F.; Shoran, R.W.

1991-12-01

This paper reports on data pattern advances observed in preset, single event upset (SEU) hardened clocked flip-flops, during static Cf-252 exposures on a bulk CMOS microprocessor, that were attributable to particle caused anomalous clock signals, or propagated transients. SPICE simulations established that particle strikes in the output nodes of a clock control logic flip-flop could produce transients of sufficient amplitude and duration to be accepted as legitimate pulses by clock buffers fed by the flip-flop's output nodes. The buffers would then output false clock pulses, thereby advancing the state of the present flip-flops. Masking the clock logic on one ofmore » the test chips made the flip-flop data advance cease, confirming the clock logic as the source of the SEU. By introducing N{sub 2} gas, at reduced pressures, into the SEU test chamber to attenuate Cf-252 particle LET's, a 24-26 MeV-cm{sup 2}/mg LET threshold was deduced. Subsequent tests, at the 88-inch cyclotron at Berkeley, established an LET threshold of 30 MeV-cm{sup 2}/mg (283 MeV Cu at 0{degrees}) for the generation of false clocks. Cyclotron SEU tests are considered definitive, while Cf-252 data usually is not. However, in this instance Cf-252 tests proved analytically useful, providing SEU characterization data that was both timely and inexpensive.« less

Beyond Californium-A Neutron Generator Alternative for Dosimetry and Instrument Calibration in the U.S.

PubMed

Piper, Roman K; Mozhayev, Andrey V; Murphy, Mark K; Thompson, Alan K

2017-09-01

Evaluations of neutron survey instruments, area monitors, and personal dosimeters rely on reference neutron radiations, which have evolved from the heavy reliance on (α,n) sources to a shared reliance on (α,n) and the spontaneous fission neutrons of californium-252 (Cf). Capable of producing high dose equivalent rates from an almost point source geometry, the characteristics of Cf are generally more favorable when compared to the use of (α,n) and (γ,n) sources or reactor-produced reference neutron radiations. Californium-252 is typically used in two standardized configurations: unmoderated, to yield a fission energy spectrum; or with the capsule placed within a heavy-water moderating sphere to produce a softened spectrum that is generally considered more appropriate for evaluating devices used in nuclear power plant work environments. The U.S. Department of Energy Cf Loan/Lease Program, a longtime origin of affordable Cf sources for research, testing and calibration, was terminated in 2009. Since then, high-activity sources have become increasingly cost-prohibitive for laboratories that formerly benefited from that program. Neutron generators, based on the D-T and D-D fusion reactions, have become economically competitive with Cf and are recognized internationally as important calibration and test standards. Researchers from the National Institute of Standards and Technology and the Pacific Northwest National Laboratory are jointly considering the practicality and technical challenges of implementing neutron generators as calibration standards in the U.S. This article reviews the characteristics of isotope-based neutron sources, possible isotope alternatives to Cf, and the rationale behind the increasing favor of electronically generated neutron options. The evaluation of a D-T system at PNNL has revealed characteristics that must be considered in adapting generators to the task of calibration and testing where accurate determination of a dosimetric quantity is necessary. Finally, concepts are presented for modifying the generated neutron spectra to achieve particular targeted spectra, simulating Cf or workplace environments.

Measurement of prompt fission neutron spectrum for spontaneous fission of 252Cf using γ multiplicity tagging

NASA Astrophysics Data System (ADS)

Blain, E.; Daskalakis, A.; Block, R. C.; Danon, Y.

2017-06-01

The prompt fission neutron spectrum from spontaneous fission of 252Cf is an integral part of several aspects of nuclear data. Not only is the spectrum itself of interest, but neutron detectors often use the spectrum for calibration, and other prompt fission neutron spectra are measured as a ratio to 252Cf. Therefore, reducing the uncertainties in this spectrum will allow for more accurate nuclear data to be available across a wide range of fields. The prompt fission neutron spectrum for the spontaneous fission of 252Cf was measured at Rensselaer Polytechnic Institute using the multiple γ tagging method with a 18.4-ng fission sample. An EJ-301 liquid scintillator fast neutron detector was used to measure the high energy portion of the spectrum, 0.5-7 MeV, and a thin EJ-204 plastic scintillator was used to measure the low energy portion of the spectrum, from 50 keV to 2 MeV. These spectra both show good agreement with the current evaluation of 252Cf and have low associated uncertainties providing a new high precision measurement that helps reduce the uncertainties in the prompt fission neutron spectrum for the spontaneous fission of 252Cf.

Determination of the optimum-size californium-252 neutron source for borehole capture gamma-ray analysis

USGS Publications Warehouse

Senftle, F.E.; Macy, R.J.; Mikesell, J.L.

1979-01-01

The fast- and thermal-neutron fluence rates from a 3.7 ??g 252Cf neutron source in a simulated borehole have been measured as a function of the source-to-detector distance using air, water, coal, iron ore-concrete mix, and dry sand as borehole media. Gamma-ray intensity measurements were made for specific spectral lines at low and high energies for the same range of source-to-detector distances in the iron ore-concrete mix and in coal. Integral gamma-ray counts across the entire spectrum were also made at each source-to-detector distance. From these data, the specific neutron-damage rate, and the critical count-rate criteria, we show that in an iron ore-concrete mix (low hydrogen concentration), 252Cf neutron sources of 2-40 ??g are suitable. The source size required for optimum gamma-ray sensitivity depends on the energy of the gamma ray being measured. In a hydrogeneous medium such as coal, similar measurements were made. The results show that sources from 2 to 20 ??g are suitable to obtain the highest gamma-ray sensitivity, again depending on the energy of the gamma ray being measured. In a hydrogeneous medium, significant improvement in sensitivity can be achieved by using faster electronics; in iron ore, it cannot. ?? 1979 North-Holland Publishing Co.

THERMAL NEUTRON INTENSITIES IN SOILS IRRADIATED BY FAST NEUTRONS FROM POINT SOURCES. (R825549C054)

EPA Science Inventory

Thermal-neutron fluences in soil are reported for selected fast-neutron sources, selected soil types, and selected irradiation geometries. Sources include 14 MeV neutrons from accelerators, neutrons from spontaneously fissioning ²⁵²Cf, and neutrons produced from alp...

Fast neutron counting in a mobile, trailer-based search platform

NASA Astrophysics Data System (ADS)

Hayward, Jason P.; Sparger, John; Fabris, Lorenzo; Newby, Robert J.

2017-12-01

Trailer-based search platforms for detection of radiological and nuclear threats are often based upon coded aperture gamma-ray imaging, because this method can be rendered insensitive to local variations in gamma background while still localizing the source well. Since gamma source emissions are rather easily shielded, in this work we consider the addition of fast neutron counting to a mobile platform for detection of sources containing Pu. A proof-of-concept system capable of combined gamma and neutron coded-aperture imaging was built inside of a trailer and used to detect a 252Cf source while driving along a roadway. Neutron detector types employed included EJ-309 in a detector plane and EJ-299-33 in a front mask plane. While the 252Cf gamma emissions were not readily detectable while driving by at 16.9 m standoff, the neutron emissions can be detected while moving. Mobile detection performance for this system and a scaled-up system design are presented, along with implications for threat sensing.

What happened to the moon? A lunar history mission using neutrons

DOE Office of Scientific and Technical Information (OSTI.GOV)

Breitkreutz, H.; Li, X.; Burfeindt, J.

2011-07-01

The ages of lunar rocks can be determined using the {sup 40}Ar -{sup 39}Ar technique that can be used in-situ on the moon if a neutron source, a noble gas mass spectrometer and a gas extraction and purification system are brought to the lunar surface. A possible instrument for such a task is ISAGE, which combines a strong {sup 252}Cf neutron source and a compact spectrometer for in-situ dating of e.g. the South Pole Aitken impact basin or the potentially very young basalts south of the Aristachus Plateau. In this paper, the design of the neutron source will be discussed.more » The source is assumed to be a hollow sphere surrounded by a reflector, a geometry that provides a very homogeneous flux at the irradiation position inside the sphere. The optimal source geometry depending on the experimental conditions, the costs of transportation for the reflector and the costs of the source itself are calculated. A minimum {sup 252}Cf mass of 1.5 mg is determined. (authors)« less

Analysis of linear energy transfers and quality factors of charged particles produced by spontaneous fission neutrons from 252Cf and 244Pu in the human body.

PubMed

Endo, Akira; Sato, Tatsuhiko

2013-04-01

Absorbed doses, linear energy transfers (LETs) and quality factors of secondary charged particles in organs and tissues, generated via the interactions of the spontaneous fission neutrons from (252)Cf and (244)Pu within the human body, were studied using the Particle and Heavy Ion Transport Code System (PHITS) coupled with the ICRP Reference Phantom. Both the absorbed doses and the quality factors in target organs generally decrease with increasing distance from the source organ. The analysis of LET distributions of secondary charged particles led to the identification of the relationship between LET spectra and target-source organ locations. A comparison between human body-averaged mean quality factors and fluence-averaged radiation weighting factors showed that the current numerical conventions for the radiation weighting factors of neutrons, updated in ICRP103, and the quality factors for internal exposure are valid.

Electron Attachment to Halomethanes at High Temperature: CH2CI2, CF2CI2, CH3CI, and CF3CI Attachment Rate Constants up to 1100 K

DTIC Science & Technology

2009-08-01

hour per response, including the time for reviewing instructions, searching existing data sources, gathering and maintaining the data needed, and...attachment reactions: 390i 50 meV (CH:Cl;). 124* 20 meV (CF2CI2), 670 + 70 meV (CH3CI), and 406±50 meV (CF,C1). Comparisons are made with existing data ...Research Laboratory, 29 Randolph Road, Hanscom Air Force Base . Massachusetts 01731-3010, USA (Received 15 May 2009; accepted 4 August 2009; published

MCNP SIMULATION OF THE HP(10) ENERGY RESPONSE OF A BRAZILIAN TLD ALBEDO NEUTRON INDIVIDUAL DOSEMETER, FROM THERMAL TO 20 MeV.

PubMed

Freitas, B M; Martins, M M; Pereira, W W; da Silva, A X; Mauricio, C L P

2016-09-01

The Brazilian Instituto de Radioproteção e Dosimetria (IRD) runs a neutron individual monitoring system with a home-made TLD albedo dosemeter. It has already been characterised and calibrated in some reference fields. However, the complete energy response of this dosemeter is not known, and the calibration factors for all monitored workplace neutron fields are difficult to be obtained experimentally. Therefore, to overcome such difficulties, Monte Carlo simulations have been used. This paper describes the simulation of the HP(10) neutron response of the IRD TLD albedo dosemeter using the MCNPX transport code, for energies from thermal to 20 MeV. The validation of the MCNPX modelling is done comparing the simulated results with the experimental measurements for ISO standard neutron fields of (241)Am-Be, (252)Cf, (241)Am-B and (252)Cf(D2O) and also for (241)Am-Be source moderated with paraffin and silicone. Bare (252)Cf are used for normalisation. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

An active drop counting device using condenser microphone for superheated emulsion detector

DOE Office of Scientific and Technical Information (OSTI.GOV)

Das, Mala; Marick, C.; Kanjilal, D.

2008-11-15

An active device for superheated emulsion detector is described. A capacitive diaphragm sensor or condenser microphone is used to convert the acoustic pulse of drop nucleation to electrical signal. An active peak detector is included in the circuit to avoid multiple triggering of the counter. The counts are finally recorded by a microprocessor based data acquisition system. Genuine triggers, missed by the sensor, were studied using a simulated clock pulse. The neutron energy spectrum of {sup 252}Cf fission neutron source was measured using the device with R114 as the sensitive liquid and compared with the calculated fission neutron energy spectrummore » of {sup 252}Cf. Frequency analysis of the detected signals was also carried out.« less

Identification of cellular targets involved in cardiac failure caused by PKI in oncology: an approach combining pharmacovigilance and pharmacodynamics.

PubMed

Patras de Campaigno, Emilie; Bondon-Guitton, Emmanuelle; Laurent, Guy; Montastruc, Francois; Montastruc, Jean-Louis; Lapeyre-Mestre, Maryse; Despas, Fabien

2017-07-01

The aims of the present study were to evaluate the risk of cardiac failure (CF) associated with 15 anticancer protein kinase inhibitors (PKIs) through a case/noncase analysis and to identify which PK(s) and pathways are involved in PKI-induced CF. In order to evaluate the risk of CF, adjusted reporting odds ratios (aRORs) were calculated for the 15 anticancer PKIs in the World Health Organization safety report database (VigiBase®). We realised a literature review to identify 21 protein kinases (PKs) that were possibly involved in CF caused by PKIs. Pearson correlation coefficients (r) between aRORs and affinity data of the 15 PKIs for the 21 PKs were calculated to identify the cellular target most likely to be involved in PKI-induced CF. A total of 141 601 individual case safety reports (ICSRs) were extracted from VigiBase® for the following PKIs: afatinib, axitinib, bosutinib, crizotinib, dasatinib, erlotinib, gefitinib, imatinib, lapatinib, nilotinib, pazopanib, ruxolitinib, sorafenib, sunitinib and vandetanib. Among them, 2594 ICSRs concerned CF. The disproportionality analysis revealed that, for dasatinib, imatinib, bosutinib, sunitinib and nilotinib, disproportionality for CF was significantly higher than for other PKIs, with aRORs of 2.52 [95% CI 2.26, 2.82], 1.79 (95% CI 1.57, 2.03), 1.73 (95% CI 1.18, 2.54), 1.67 (95% CI 1.51, 1.84) and 1.38 (95% CI 1.18, 1.61), respectively. Significant values for correlation coefficients between the product of dissociation constant (pKd) and aROR were observed for two non-receptor protein kinases: ABL1 (non-phosphorylated and phosphorylated forms) and ABL2 protein kinases, with values of r = 0.83 (P = 0.0001), r = 0.75 (P = 0.0014) and r = 0.78 (P = 0.0006), respectively. We observed a higher disproportionality for CF with dasatinib, imatinib, bosutinib, sunitinib and nilotinib than with other PKIs. In addition, the study highlighted the role of ABL tyrosine kinases in CF caused by anticancer PKIs. © 2017 The British Pharmacological Society.

In situ calibration of neutron activation system on the large helical device

NASA Astrophysics Data System (ADS)

Pu, N.; Nishitani, T.; Isobe, M.; Ogawa, K.; Kawase, H.; Tanaka, T.; Li, S. Y.; Yoshihashi, S.; Uritani, A.

2017-11-01

In situ calibration of the neutron activation system on the Large Helical Device (LHD) was performed by using an intense 252Cf neutron source. To simulate a ring-shaped neutron source, we installed a railway inside the LHD vacuum vessel and made a train loaded with the 252Cf source run along a typical magnetic axis position. Three activation capsules loaded with thirty pieces of indium foils stacked with total mass of approximately 18 g were prepared. Each capsule was irradiated over 15 h while the train was circulating. The activation response coefficient (9.4 ± 1.2) × 10-8 of 115In(n, n')115mIn reaction obtained from the experiment is in good agreement with results from three-dimensional neutron transport calculations using the Monte Carlo neutron transport simulation code 6. The activation response coefficients of 2.45 MeV birth neutron and secondary 14.1 MeV neutron from deuterium plasma were evaluated from the activation response coefficient obtained in this calibration experiment with results from three-dimensional neutron calculations using the Monte Carlo neutron transport simulation code 6.

Development and operation of a 6LiF:ZnS(Ag)-scintillating plastic capture-gated detector

NASA Astrophysics Data System (ADS)

Wilhelm, K.; Nattress, J.; Jovanovic, I.

2017-01-01

We report on the design, construction, and operation of a capture-gated neutron detector based on a heterogeneous scintillating structure comprising two scintillator types. A flat, 500 μm thick sheet composed of a mixture of lithium-6-fluoride capture agent, 6LiF, and zinc sulfide phosphor, ZnS(Ag), is wrapped around scintillating polyvinyl toluene (PVT) in a form of cylinder. The 6LiF: ZnS(Ag) sheet uses an aluminum foil backing as a support for the scintillating material and as an optical reflector, and its optical properties have been characterized independently. The composite scintillator was tested using 252Cf, DD fusion, 137Cs, and 60Co sources. The intrinsic detection efficiency for neutrons from an unmoderated 252Cf source and rejection of gammas from 137Cs were measured to be 3.6 % and 10-6, respectively. A figure of merit for pulse shape discrimination of 4.6 was achieved, and capture-gated spectroscopic analysis is demonstrated.

A feasibility study of [sup 252]Cf neutron brachytherapy, cisplatin + 5-FU chemo-adjuvant and accelerated hyperfractionated radiotherapy for advanced cervical cancer

DOE Office of Scientific and Technical Information (OSTI.GOV)

Murayama, Y.; Wierzbicki, J.; Bowen, M.G.

The purpose was to evaluate the feasibility and toxicity of [sup 252]Cf neutron brachytherapy combined with hyperaccelerated chemoradiotherapy for Stage III and IV cervical cancers. Eleven patients with advanced Stage IIIB-IVA cervical cancers were treated with [sup 252]Cf neutron brachytherapy in an up-front schedule followed by cisplatin (CDDP; 50 mg/m[sup 2]) chemotherapy and hyperfractionated accelerated (1.2 Gy bid) radiotherapy given concurrently with intravenous infusion of 5-Fluorouracil (5-FU) (1000 mg/m[sup 2]/day [times] 4 days) in weeks 1 and 4 with conventional radiation (weeks 2, 3, 5, and 6). Total dose at a paracervical point A isodose surface was 80-85 Gy-eq bymore » external and intracavitary therapy and 60 Gy at the pelvic sidewalls. Patients tolerated the protocol well. There was 91% compliance with the chemotherapy and full compliance with the [sup 252]Cf brachytherapy and the external beam radiotherapy. There were no problems with acute chemo or radiation toxicity. One patient developed a rectovaginal fistula (Grade 3-4 RTOG criteria) but no other patients developed significant late cystitis, proctitis or enteritis. There was complete response (CR) observed in all cases. With mean follow-up to 26 months, local control has been achieved with 90% actuarial 3-year survival with no evidence of disease (NED). [sup 252]Cf neutrons can be combined with cisplatin and 5-FU infusion chemotherapy plus hyperaccelerated chemoradiotherapy without unusual side effects or toxicity and with a high local response and tumor control rate. Further study of [sup 252]Cf neutron-chemoradiotherapy for advanced and bulky cervical cancer are indicated. The authors found chemotherapy was more effective with the improved local tumor control. 18 refs., 2 tabs.« less

Calibration of neutron detectors on the Joint European Torus.

PubMed

Batistoni, Paola; Popovichev, S; Conroy, S; Lengar, I; Čufar, A; Abhangi, M; Snoj, L; Horton, L

2017-10-01

The present paper describes the findings of the calibration of the neutron yield monitors on the Joint European Torus (JET) performed in 2013 using a 252 Cf source deployed inside the torus by the remote handling system, with particular regard to the calibration of fission chambers which provide the time resolved neutron yield from JET plasmas. The experimental data obtained in toroidal, radial, and vertical scans are presented. These data are first analysed following an analytical approach adopted in the previous neutron calibrations at JET. In this way, a calibration function for the volumetric plasma source is derived which allows us to understand the importance of the different plasma regions and of different spatial profiles of neutron emissivity on fission chamber response. Neutronics analyses have also been performed to calculate the correction factors needed to derive the plasma calibration factors taking into account the different energy spectrum and angular emission distribution of the calibrating (point) 252 Cf source, the discrete positions compared to the plasma volumetric source, and the calibration circumstances. All correction factors are presented and discussed. We discuss also the lessons learnt which are the basis for the on-going 14 MeV neutron calibration at JET and for ITER.

Viability of Acremonium coenophialum in tall fescue seed after ionizing radiation treatments

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bagegni, A.M.; Sleper, D.A.; Kerr, H.D.

Planting tall fescue (Festuca arundinacea Schreb.) seed free of the endophyte Acremonium coenophialum Morgan-Jones and Gams allows establishment of swards free of the fungus. Eradication of the fungal endophyte from infected tall fescue seeds containing 130 g kg{sup {minus}1} moisture using ionizing radiation was investigated. Three sources of radiation were used: gamma rays ({sup 60}Co source), neutron particles ({sup 252}Cf source), and a thermal neutron beam. The percent germination of tall fescue seeds among gamma doses did not differ significantly (P < 0.05) from the control treatment and did not show a significant negative response (R{sub 2} = 0.41) tomore » increasing levels of gamma radiation. At 250 Gy of gamma radiation, percent germination after 14 d was still > 90%. Percent seed germination of tall fescue and high levels of radiation were negatively correlated for both sources of neutrons. Gamma radiation was shown to reduce (P < 0.01) the percent of the viable endophyte to {approx} 10% of control. The {sup 252}Cf and thermal neutrons reduced the percent of tall fescue infected by the endophyte to {approx} 30% without deleterious effects on seed germination.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kelley, R.P., E-mail: rpkelley@ufl.edu; Ray, H.; Jordan, K.A.

An empirical investigation of the scintillation mechanism in a pressurized {sup 4}He gas fast neutron detector was conducted using pulse shape fitting. Scintillation signals from neutron interactions were measured and averaged to produce a single generic neutron pulse shape from both a {sup 252}Cf spontaneous fission source and a (d,d) neutron generator. An expression for light output over time was then developed by treating the decay of helium excited states in the same manner as the decay of radioactive isotopes. This pulse shape expression was fitted to the measured neutron pulse shape using a least-squares optimization algorithm, allowing an empiricalmore » analysis of the mechanism of scintillation inside the {sup 4}He detector. A further understanding of this mechanism in the {sup 4}He detector will advance the use of this system as a neutron spectrometer. For {sup 252}Cf neutrons, the triplet and singlet time constants were found to be 970 ns and 686 ns, respectively. For neutrons from the (d,d) generator, the time constants were found to be 884 ns and 636 ns. Differences were noted in the magnitude of these parameters compared to previously published data, however the general relationships were noted to be the same and checked with expected trends from theory. Of the excited helium states produced from a {sup 252}Cf neutron interaction, 76% were found to be born as triplet states, similar to the result from the neutron generator of 71%. The two sources yielded similar pulse shapes despite having very different neutron energy spectra, validating the robustness of the fits across various neutron energies.« less

Simulation of the neutron response matrix of an EJ309 liquid scintillator

NASA Astrophysics Data System (ADS)

Bai, Huaiyong; Wang, Zhimin; Zhang, Luyu; Jiang, Haoyu; Lu, Yi; Chen, Jinxiang; Zhang, Guohui

2018-04-01

The neutron response matrix is the basis for measuring the neutron energy spectrum through unfolding the pulse height spectrum detected with a liquid scintillator. Based on the light output of the EJ309 liquid scintillator and the related reaction cross sections, a Monte Carlo code is developed to obtain the neutron response matrix. The effects of the related reactions, the contributions of different number of neutron interactions and the wall effect of the recoil proton are discussed. With the obtained neutron response matrix and the GRAVEL iterative unfolding method, the neutron energy spectra of the 252Cf and the 241AmBe neutron sources are measured, and the results are respectively compared with the theoretical prediction of the 252Cf neutron energy spectrum and the previous results of the 241AmBe neutron energy spectra.

French comparison exercise with the rotating neutron spectrometer, 'ROSPEC'.

PubMed

Crovisier, P; Asselineau, B; Pelcot, G; Van-Ryckeghem, L; Cadiou, A; Truffert, H; Groetz, J E; Benmosbah, M

2005-01-01

The French laboratories in charge of 'neutron' dosimetry using the spectrometer 'ROSPEC', formed a working group in 2001. The participants began to study the behaviour of the instrument with a comparison exercise in broad energy neutron fields recommended by the International Organisation for Standardisation (ISO) and available at the LMDN in Cadarache. The complete version of the ROSPEC is made up of six spherical proportional counters fixed to a rotating platform. These counters cover different energy ranges which overlap each other to provide a link between the detectors, within the energy range from thermal neutrons to 4.5 MeV. The irradiation configurations chosen were ISO standard sources (252Cf, (252Cf+D2O)(/Cd), 241Am-Be) and the SIGMA facility. The results show that the 'thermal and epithermal' neutron fluence was widely overestimated by the spectrometer in all configurations.

Detection of ternary and quaternary fission fragments from 252Cf with a position-sensitive ΔE-E telescope based on silicon detectors

NASA Astrophysics Data System (ADS)

Ahmadov, G. S.; Kopatch, Yu. N.; Telezhnikov, S. A.; Ahmadov, F. I.; Granja, C.; Garibov, A. A.; Pospisil, S.

2015-07-01

The silicon based pixel detector Timepix is a multi-parameter detector which gives simultaneously information about position, energy and arrival time of a particle hitting the detector. Applying the ΔE-E method with these detectors makes it possible to determine types of detected particles, separating them by charge. Using a thin silicon detector with thickness of 12 μm combined with a Timepix (300 μm), a ΔE-E telescope has been constructed. The telescope provides information about position, energy, time and type of registered particles. The emission probabilities and the energy distributions of ternary particles (He, Li, Be) from 252Cf spontaneous fission source were determined using this telescope. Besides the ternary particles, a few events were collected, which were attributed to the "pseudo" quaternary fission.

AN INTERLABORATORY COMPARISON ON THE DETERMINATION OF 241Am, 244Cm AND 252Cf IN URINE.

PubMed

Gerstmann, Udo C; Taubner, Kerstin; Hartmann, Martina

2016-09-01

An intercomparison exercise on the determination of (241)Am, (244)Cm and (252)Cf in urine was performed. Since it was designed with regard to emergency preparedness, the detection limit for each nuclide was set to 0.1 Bq per 24-h urine sample. Most of the participating laboratories were established bioassay laboratories. However, some laboratories that routinely determine (241)Am only in environmental samples were also invited in order to explore their potential for emergency bioassay analysis. Another aspect of the intercomparison was to investigate the performance of all laboratories concerning the chemical yields of the (243)Am tracer in comparison with (244)Cm and (252)Cf. In summary, both types of laboratories showed good results. There was a negative bias for the results of (244)Cm and (252)Cf, which can be explained by slightly different radiochemical behaviours of americium, curium and californium and which is in agreement with results reported in the literature. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Neutron noise measurements at the Delphi subcritical assembly

DOE Office of Scientific and Technical Information (OSTI.GOV)

Szieberth, M.; Klujber, G.; Kloosterman, J. L.

2012-07-01

The paper presents the results and evaluations of a comprehensive set of neutron noise measurements on the Delphi subcritical assembly of the Delft Univ. of Technology. The measurements investigated the effect of different source distributions (inherent spontaneous fission and {sup 252}Cf) and the position of the detectors applied (both radially and vertically). The evaluation of the measured data has been performed by the variance-to-mean ratio (VTMR, Feynman-{alpha}), the autocorrelation (ACF, Rossi-{alpha}) and the cross-correlation (CCF) methods. The values obtained for the prompt decay constant show a strong bias, which depends both on the detector position and on the source distribution.more » This is due to the presence of higher modes in the system. It has been observed that the {alpha} value fitted is higher when the detector is close to the boundary of the core or to the {sup 252}Cf point-source. The higher alpha-modes have also been observed by fitting functions describing two alpha-modes. The successful set of measurement also provides a good basis for further theoretical investigations including the Monte Carlo simulation of the noise measurements and the calculation of the alpha-modes in the Delphi subcritical assembly. (authors)« less

Development of a new method for measurement of neutron detector efficiency up to 20 MeV

DOE PAGES

Kornilov, N. V.; Grimes, S. M.; Massey, T. N.; ...

2014-09-03

A new approach to neutron detector efficiency has been taken. A neutron detector has been calibrated with a 252Cf source at low energy. The calibration can be extended to energies above 8 MeV based on the 252Cf results. The techniques uses the fact that the cross section for a symmetric reaction with nucleus of atomic number A yielding a final nucleus with atomic number (2A-1) and a neutron A + A → (2A – 1) + n. This reaction must be symmetric about 90° in the center-of-mass system. Furthermore, the laboratory energies for the neutrons at the paired energies differmore » substantially. Thus, an efficiency known at one of the two angles can be used to determine the efficiency to higher energies or, for a negative Q, to lower neutron energies.« less

Performance of the electronic personal dosemeter for neutron 'Saphydose-N' at different workplaces of nuclear facilities.

PubMed

Lahaye, T; Chau, Q; Ménard, S; Lacoste, V; Muller, H; Luszik-Bhadra, M; Reginatto, M; Bruguier, P

2006-01-01

This paper mainly aims at presenting the measurements and the results obtained with the electronic personal neutron dosemeter Saphydose-N at different facilities. Three campaigns were led in the frame of the European contract EVIDOS ('Evaluation of Individual Dosimetry in Mixed Neutron and Photon Radiation Fields'). The first one consisted in the measurements at the IRSN French research laboratory in reference neutron fields generated by a thermal facility (SIGMA), radionuclide ISO sources ((241)AmBe; (252)Cf; (252)Cf(D(2)O)\\Cd) and a realistic spectrum (CANEL/T400). The second one was performed at the Krümmel Nuclear Power Plant (Germany) close to the boiling water reactor and to a spent fuel transport cask. The third one was realised at Mol (Belgium), at the VENUS Research Reactor and at Belgonucléaire, a fuel processing factory.

A physics investigation of deadtime losses in neutron counting at low rates with Cf252

DOE Office of Scientific and Technical Information (OSTI.GOV)

Evans, Louise G; Croft, Stephen

2009-01-01

{sup 252}Cf spontaneous fission sources are used for the characterization of neutron counters and the determination of calibration parameters; including both neutron coincidence counting (NCC) and neutron multiplicity deadtime (DT) parameters. Even at low event rates, temporally-correlated neutron counting using {sup 252}Cf suffers a deadtime effect. Meaning that in contrast to counting a random neutron source (e.g. AmLi to a close approximation), DT losses do not vanish in the low rate limit. This is because neutrons are emitted from spontaneous fission events in time-correlated 'bursts', and are detected over a short period commensurate with their lifetime in the detector (characterizedmore » by the system die-away time, {tau}). Thus, even when detected neutron events from different spontaneous fissions are unlikely to overlap in time, neutron events within the detected 'burst' are subject to intrinsic DT losses. Intrinsic DT losses for dilute Pu will be lower since the multiplicity distribution is softer, but real items also experience self-multiplication which can increase the 'size' of the bursts. Traditional NCC DT correction methods do not include the intrinsic (within burst) losses. We have proposed new forms of the traditional NCC Singles and Doubles DT correction factors. In this work, we apply Monte Carlo neutron pulse train analysis to investigate the functional form of the deadtime correction factors for an updating deadtime. Modeling is based on a high efficiency {sup 3}He neutron counter with short die-away time, representing an ideal {sup 3}He based detection system. The physics of dead time losses at low rates is explored and presented. It is observed that new forms are applicable and offer more accurate correction than the traditional forms.« less

Preliminary calibration of the ACP safeguards neutron counter

NASA Astrophysics Data System (ADS)

Lee, T. H.; Kim, H. D.; Yoon, J. S.; Lee, S. Y.; Swinhoe, M.; Menlove, H. O.

2007-10-01

The Advanced Spent Fuel Conditioning Process (ACP), a kind of pyroprocess, has been developed at the Korea Atomic Energy Research Institute (KAERI). Since there is no IAEA safeguards criteria for this process, KAERI has developed a neutron coincidence counter to make it possible to perform a material control and accounting (MC&A) for its ACP materials for the purpose of a transparency in the peaceful uses of nuclear materials at KAERI. The test results of the ACP Safeguards Neutron Counter (ASNC) show a satisfactory performance for the Doubles count measurement with a low measurement error for its cylindrical sample cavity. The neutron detection efficiency is about 21% with an error of ±1.32% along the axial direction of the cavity. Using two 252Cf neutron sources, we obtained various parameters for the Singles and Doubles rates for the ASNC. The Singles, Doubles, and Triples rates for a 252Cf point source were obtained by using the MCNPX code and the results for the ft8 cap multiplicity tally option with the values of ɛ, fd, and ft measured with a strong source most closely match the measurement results to within a 1% error. A preliminary calibration curve for the ASNC was generated by using the point model equation relationship between 244Cm and 252Cf and the calibration coefficient for the non-multiplying sample is 2.78×10 5 (Doubles counts/s/g 244Cm). The preliminary calibration curves for the ACP samples were also obtained by using an MCNPX simulation. A neutron multiplication influence on an increase of the Doubles rate for a metal ingot and UO2 powder is clearly observed. These calibration curves will be modified and complemented, when hot calibration samples become available. To verify the validity of this calibration curve, a measurement of spent fuel standards for a known 244Cm mass will be performed in the near future.

A new method for using Cf-252 in SEU testing

NASA Astrophysics Data System (ADS)

Costantine, A.; Howard, J. W.; Becker, M.; Block, R. C.; Smith, L. S.; Soli, G. A.; Stauber, M. C.

1990-12-01

A system using Cf-252 and associated nuclear instrumentation has determined the single-event upset (SEU) cross section versus linear energy transfer (LET) curve for several 2K x 8 static random access memories (SRAMs). The Cf-252 fission fragments pass through a thin-film organic scintillator detector (TFD) on the way to the device under test (DUT). The TFD provides energy information for each transiting fragment. Data analysis provides the energy of the individual ion responsible for each SEU; thus, separate upset cross sections can be developed for different energy and mass regions of the californium spectrum. This californium-based device is quite small and fits onto a bench top. It provides a convenient and inexpensive supplement or alternative to accelerator and high-altitude/space SEU testing.

A new method for using Cf-252 in SEU testing

NASA Technical Reports Server (NTRS)

Costantine, A.; Howard, J. W.; Becker, M.; Block, R. C.; Smith, L. S.; Soli, G. A.; Stauber, M. C.

1990-01-01

A system using Cf-252 and associated nuclear instrumentation has determined the single-event upset (SEU) cross section versus linear energy transfer (LET) curve for several 2K x 8 static random access memories (SRAMs). The Cf-252 fission fragments pass through a thin-film organic scintillator detector (TFD) on the way to the device under test (DUT). The TFD provides energy information for each transiting fragment. Data analysis provides the energy of the individual ion responsible for each SEU; thus, separate upset cross sections can be developed for different energy and mass regions of the californium spectrum. This californium-based device is quite small and fits onto a bench top. It provides a convenient and inexpensive supplement or alternative to accelerator and high-altitude/space SEU testing.

Studying fission neutrons with 2E-2v and 2E

NASA Astrophysics Data System (ADS)

Al-Adili, Ali; Jansson, Kaj; Tarrío, Diego; Hambsch, Franz-Josef; Göök, Alf; Oberstedt, Stephan; Olivier Frégeau, Marc; Gustavsson, Cecilia; Lantz, Mattias; Mattera, Andrea; Prokofiev, Alexander V.; Rakopoulos, Vasileios; Solders, Andreas; Vidali, Marzio; Österlund, Michael; Pomp, Stephan

2018-03-01

This work aims at measuring prompt-fission neutrons at different excitation energies of the nucleus. Two independent techniques, the 2E-2v and the 2E techniques, are used to map the characteristics of the mass-dependent prompt fission neutron multiplicity, v(A), when the excitation energy is increased. The VERDI 2E-2v spectrometer is being developed at JRC-GEEL. The Fission Fragment (FF) energies are measured using two arrays of 16 silicon (Si) detectors each. The FFs velocities are obtained by time-of-flight, measured between micro-channel plates (MCP) and Si detectors. With MCPs placed on both sides of the fission source, VERDI allows for independent timing measurements for both fragments. 252Cf(sf) was measured and the present results revealed particular features of the 2E-2v technique. Dedicated simulations were also performed using the GEF code to study important aspects of the 2E-2v technique. Our simulations show that prompt neutron emission has a non-negligible impact on the deduced fragment data and affects also the shape of v(A). Geometrical constraints lead to a total-kinetic energy-dependent detection efficiency. The 2E technique utilizes an ionization chamber together with two liquid scintillator detectors. Two measurements have been performed, one of 252Cf(sf) and another one of thermal-neutron induced fission in 235U(n,f). Results from 252Cf(sf) are reported here.

Technical basis for the use of a correlated neutron source in the uranium neutron coincidence collar

DOE PAGES

Root, Margaret A.; Menlove, Howard Olsen; Lanza, Richard C.; ...

2017-01-16

Active neutron coincidence systems are commonly used by international inspectorates to verify a material balance across the various stages of the nuclear fuel cycle. The Uranium Neutron Coincidence Collar (UNCL) is one such instrument; it is used to measure the linear density of 235U (g 235U/cm of active length in assembly) in fresh light water reactor fuel in nuclear fuel fabrication facilities. The UNCL and other active neutron interrogation detectors have historically relied on americium lithium ( 241AmLi) sources to induce fission within the sample in question. Californium-252 is under consideration as a possible alternative to the traditional 241AmLi source.more » Finally, this work relied upon a combination of experiments and Monte Carlo simulations to demonstrate the technical basis for the replacement of 241AmLi sources with 252Cf sources by evaluating the statistical uncertainty in the measurements incurred by each source and assessing the penetrability of neutrons from each source for the UNCL.« less

Technical basis for the use of a correlated neutron source in the uranium neutron coincidence collar

DOE Office of Scientific and Technical Information (OSTI.GOV)

Root, Margaret A.; Menlove, Howard Olsen; Lanza, Richard C.

Active neutron coincidence systems are commonly used by international inspectorates to verify a material balance across the various stages of the nuclear fuel cycle. The Uranium Neutron Coincidence Collar (UNCL) is one such instrument; it is used to measure the linear density of 235U (g 235U/cm of active length in assembly) in fresh light water reactor fuel in nuclear fuel fabrication facilities. The UNCL and other active neutron interrogation detectors have historically relied on americium lithium ( 241AmLi) sources to induce fission within the sample in question. Californium-252 is under consideration as a possible alternative to the traditional 241AmLi source.more » Finally, this work relied upon a combination of experiments and Monte Carlo simulations to demonstrate the technical basis for the replacement of 241AmLi sources with 252Cf sources by evaluating the statistical uncertainty in the measurements incurred by each source and assessing the penetrability of neutrons from each source for the UNCL.« less

Studies On Particle-Accompanied Fission Of 252Cf(sf) And 235U(nth,f)

NASA Astrophysics Data System (ADS)

Kopatch, Yu N.; Tishchenko, V.; Speransky, M.; Mutterer, M.; Gönnenwein, F.; Jesinger, P.; Gagarski, A. M.; von Kalben, J.; Kojouharov, I.; Lubkiewics, E.; Mezentseva, Z.; Nezvishevsky, V.; Petrov, G. A.; Schaffner, H.; Scharma, H.; Trzaska, W. H.; Wollersheim, H.-J.

2005-11-01

In recent multi-parameter studies of spontaneous and thermal neutron induced fission, 252Cf(sf) and 235U(nth,f) respectively, the energies and emission angles of fission fragments and light charged particles were measured. Fragments were detected by an energy and angle sensitive twin ionization chamber while the light charged particles were identified by a series of ΔE-Erest telescopes. Up to Be the light particle isotopes could be disentangled. In addition, in the 252Cf(sf) experiment, gammas emitted by the fragments were analyzed by a pair of large-volume segmented clover Ge detectors. Here the main interest is to study the γ-decay and the anisotropy of gammas emitted by fragments and light particles. On the other hand, the high count rates achieved in the U-experiment performed at the high flux reactor of the ILL, Grenoble, should allow to explore fragment-particle correlations in very rare events like quaternary fission. At the present stage of data evaluation, yields and energy distributions of light particles are available. For the present contribution in particular the yields of Be-isotopes for the two reactions studied are compared and discussed. For 252Cf(sf) these isotopic yields were hitherto not known.

Evaluation of PM emissions from two in-service gas turbine general aviation aircraft engines

NASA Astrophysics Data System (ADS)

Yu, Zhenhong; Liscinsky, David S.; Fortner, Edward C.; Yacovitch, Tara I.; Croteau, Philip; Herndon, Scott C.; Miake-Lye, Richard C.

2017-07-01

We determined particulate matter (PM) emissions in the exhaust plumes from two gas turbine aircraft engines: a CF34-3A1 turbofan engine and a TPE331-6-252B turboprop engine in a dedicated study on in-service general aviation aircraft. The engine power states were from 16% to 100% engine thrust. Both nucleation and soot mode particles were observed from the emission exhausts of the CF34-3A1 engine but only soot particle mode was detected from the TPE331-6-252B engine. For the CF34-3A1 engine, the contribution of soot mode to total PM emissions was dominant at high power, while at decreased engine power states nucleation mode organic PM became important. PM emissions indices of the TPE331-6-252B engine were found to be generally larger than those of the CF34-3A1 engine. For both engines, medium power conditions (40-60% of thrust) yielded the lowest PM emissions. For the TPE331-6-252B engine, volatile PM components including organic and sulfate were more than 50% in mass at low power, while non-volatile black carbon became dominant at high power conditions such as takeoff.

An equivalent n-source for WGPu derived from a spectrum-shifted PuBe source

NASA Astrophysics Data System (ADS)

Ghita, Gabriel; Sjoden, Glenn; Baciak, James; Walker, Scotty; Cornelison, Spring

2008-04-01

We have designed, built, and laboratory-tested a unique shield design that transforms the complex neutron spectrum from PuBe source neutrons, generated at high energies, to nearly exactly the neutron signature leaking from a significant spherical mass of weapons grade plutonium (WGPu). This equivalent "X-material shield assembly" (Patent Pending) enables the harder PuBe source spectrum (average energy of 4.61 MeV) from a small encapsulated standard 1-Ci PuBe source to be transformed, through interactions in the shield, so that leakage neutrons are shifted in energy and yield to become a close reproduction of the neutron spectrum leaking from a large subcritical mass of WGPu metal (mean energy 2.11 MeV). The utility of this shielded PuBe surrogate for WGPu is clear, since it directly enables detector field testing without the expense and risk of handling large amounts of Special Nuclear Materials (SNM) as WGPu. Also, conventional sources using Cf-252, which is difficult to produce, and decays with a 2.7 year half life, could be replaced by this shielded PuBe technology in order to simplify operational use, since a sealed PuBe source relies on Pu-239 (T½=24,110 y), and remains viable for more than hundreds of years.

Historical review of californium-252 discovery and development

DOE Office of Scientific and Technical Information (OSTI.GOV)

Stoddard, D.H.

1985-01-01

This paper discusses the discovery and history of californium 252. This isotope may be synthesized by irradiating plutonium 239, plutonium 242, americium 243, or curium 244 with neutrons in a nuclear reactor. Various experiments and inventions involving /sup 252/Cf conducted at the Savannah River Plant are discussed. The evolution of radiotherapy using californium 252 is reviewed. (PLG)

Results from field tests of the one-dimensional Time-Encoded Imaging System.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Marleau, Peter; Brennan, James S.; Brubaker, Erik

2014-09-01

A series of field experiments were undertaken to evaluate the performance of the one dimensional time encoded imaging system. The significant detection of a Cf252 fission radiation source was demonstrated at a stand-off of 100 meters. Extrapolations to different quantities of plutonium equivalent at different distances are made. Hardware modifications to the system for follow on work are suggested.

Single-view 3D reconstruction of correlated gamma-neutron sources

DOE PAGES

Monterial, Mateusz; Marleau, Peter; Pozzi, Sara A.

2017-01-05

We describe a new method of 3D image reconstruction of neutron sources that emit correlated gammas (e.g. Cf- 252, Am-Be). This category includes a vast majority of neutron sources important in nuclear threat search, safeguards and non-proliferation. Rather than requiring multiple views of the source this technique relies on the source’s intrinsic property of coincidence gamma and neutron emission. As a result only a single-view measurement of the source is required to perform the 3D reconstruction. In principle, any scatter camera sensitive to gammas and neutrons with adequate timing and interaction location resolution can perform this reconstruction. Using a neutronmore » double scatter technique, we can calculate a conical surface of possible source locations. By including the time to a correlated gamma we further constrain the source location in three-dimensions by solving for the source-to-detector distance along the surface of said cone. As a proof of concept we applied these reconstruction techniques on measurements taken with the the Mobile Imager of Neutrons for Emergency Responders (MINER). Two Cf-252 sources measured at 50 and 60 cm from the center of the detector were resolved in their varying depth with average radial distance relative resolution of 26%. To demonstrate the technique’s potential with an optimized system we simulated the measurement in MCNPX-PoliMi assuming timing resolution of 200 ps (from 2 ns in the current system) and source interaction location resolution of 5 mm (from 3 cm). Furthermore, these simulated improvements in scatter camera performance resulted in radial distance relative resolution decreasing to an average of 11%.« less

Single-view 3D reconstruction of correlated gamma-neutron sources

DOE Office of Scientific and Technical Information (OSTI.GOV)

Monterial, Mateusz; Marleau, Peter; Pozzi, Sara A.

We describe a new method of 3D image reconstruction of neutron sources that emit correlated gammas (e.g. Cf- 252, Am-Be). This category includes a vast majority of neutron sources important in nuclear threat search, safeguards and non-proliferation. Rather than requiring multiple views of the source this technique relies on the source’s intrinsic property of coincidence gamma and neutron emission. As a result only a single-view measurement of the source is required to perform the 3D reconstruction. In principle, any scatter camera sensitive to gammas and neutrons with adequate timing and interaction location resolution can perform this reconstruction. Using a neutronmore » double scatter technique, we can calculate a conical surface of possible source locations. By including the time to a correlated gamma we further constrain the source location in three-dimensions by solving for the source-to-detector distance along the surface of said cone. As a proof of concept we applied these reconstruction techniques on measurements taken with the the Mobile Imager of Neutrons for Emergency Responders (MINER). Two Cf-252 sources measured at 50 and 60 cm from the center of the detector were resolved in their varying depth with average radial distance relative resolution of 26%. To demonstrate the technique’s potential with an optimized system we simulated the measurement in MCNPX-PoliMi assuming timing resolution of 200 ps (from 2 ns in the current system) and source interaction location resolution of 5 mm (from 3 cm). Furthermore, these simulated improvements in scatter camera performance resulted in radial distance relative resolution decreasing to an average of 11%.« less

Californium-252 Program Equipment Evaluation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chattin, Fred Rhea; Wilson, Kenton; Ezold, Julie G.

2017-12-01

To successfully continue the 252Cf production and meet the needs of the customers, a comprehensive evaluation of the Building 7920 processing equipment was requested to identify equipment critical to the operational continuity of the program.

{sup 252}Cf-plasma desorption mass spectra of bacterial oligosaccharides

DOE Office of Scientific and Technical Information (OSTI.GOV)

Elkin, Y.N.; Komandrova, N.A.; Tomshich, S.V.

1994-07-20

The possibility has been investigated of using the MSBKh instrument ({sup 252}Cf plasma desorption mass spectrometer) for studying the oligosaccharides of the O-specific chains of bacterial lipopolysaccharides. Experimental results on the ionization of galacturonic acid and of neutral and bacterial oligosaccharides containing NHR and COOH groups have been obtained and are discussed. The instrument has been used for estimating the compositions of fractions in the separation of degradation products of O-specific polysaccharide chains and establishing their structures.

GEANT4 and PHITS simulations of the shielding of neutrons from the 252Cf source

NASA Astrophysics Data System (ADS)

Shin, Jae Won; Hong, Seung-Woo; Bak, Sang-In; Kim, Do Yoon; Kim, Chong Yeal

2014-09-01

Monte Carlo simulations are performed by using the GEANT4 and the PHITS for studying the neutron-shielding abilities of several materials, such as graphite, iron, polyethylene, NS-4-FR and KRAFTON-HB. As a neutron source, 252Cf is considered. For the Monte Carlo simulations by using the GEANT4, high precision (G4HP) models with the G4NDL 4.2 based on ENDF/B-VII data are used. For the simulations by using the PHITS, the JENDL-4.0 library is used. The neutron-dose-equivalent rates with or without five different shielding materials are estimated and compared with the experimental values. The differences between the shielding abilities calculated by using the GEANT4 with the G4NDL 4.2 and the PHITS with the JENDL-4.0 are found not to be significant for all the cases considered in this work. The neutron-dose-equivalent rates obtained by using the GEANT4 and the PHITS are compared with experimental data and other simulation results. Our neutron-dose-equivalent rates agree well with the experimental dose-equivalent rates, within 20% errors, except for polyethylene. For polyethylene, the discrepancies between our calculations and the experiments are less than 40%, as observed in other simulation results.

Design and feasibility of a multi-detector neutron spectrometer for radiation protection applications based on thermoluminescent 6LiF:Ti,Mg (TLD-600) detectors

NASA Astrophysics Data System (ADS)

Lis, M.; Gómez-Ros, J. M.; Bedogni, R.; Delgado, A.

2008-01-01

The design of a neutron detector with spectrometric capability based on thermoluminescent (TL) 6LiF:Ti,Mg (TLD-600) dosimeters located along three perpendicular axis within a single polyethylene (PE) sphere has been analyzed. The neutron response functions have been calculated in the energy range from 10 -8 to 100 MeV with the Monte Carlo (MC) code MCNPX 2.5 and their shape and behaviour have been used to discuss a suitable configuration for an actual instrument. The feasibility of such a device has been preliminary evaluated by the simulation of exposure to 241Am-Be, bare 252Cf and Fe-PE moderated 252Cf sources. The expected accuracy in the evaluation of energy quantities has been evaluated using the unfolding code FRUIT. The obtained results together with additional calculations performed using MAXED and GRAVEL codes show the spectrometric capability of the proposed design for radiation protection applications, especially in the range 1 keV-20 MeV.

Use of SRIM and Garfield with Geant4 for the characterization of a hybrid 10B/3He neutron detector

NASA Astrophysics Data System (ADS)

van der Ende, B. M.; Rand, E. T.; Erlandson, A.; Li, L.

2018-06-01

This paper describes a method for more complete neutron detector characterization using Geant4's Monte Carlo methods for characterizing overall detector response rate and Garfield interfaced with SRIM for the simulation of the detector's raw pulses, as applied to a hybrid 10B/3He detector. The Geant4 models characterizing the detector's interaction with a 252Cf point source and parallel beams of mono-energetic neutrons (assuming ISO 8529 reference energy values) compare and agree well with calibrated 252Cf measurements to within 6.4%. Validated Geant4 model outputs serve as input to Garfield+SRIM calculations to provide meaningful pulse height spectra. Modifications to Garfield for this work were necessary to account for simultaneous tracking of electrons resulting from proton and triton reaction products from a single 3He neutron capture event, and it was further necessary to interface Garfield with the energy loss, range, and straggling calculations provided by SRIM. Individual raw pulses generated by Garfield+SRIM are also observed to agree well with experimentally measured raw pulses from the detector.

A probe for neutron activation analysis in a drill hole using 252Cf, and a Ge(Li) detector cooled by a melting cryogen

USGS Publications Warehouse

Tanner, A.B.; Moxham, R.M.; Senftle, F.E.; Baicker, J.A.

1972-01-01

A sonde has been built for high-resolution measurement of natural or neutron-induced gamma rays in boreholes. The sonde is 7.3 cm in diameter and about 2.2 m in length and weighs about 16 kg. The lithium-compensated germanium semiconductor detector is stabilized at -185 to -188??C for as much as ten hours by a cryostatic reservoir containing melting propane. During periods when the sonde is not in use the propane is kept frozen by a gravity-fed trickle of liquid nitrogen from a reservoir temporarily attached to the cryostat section. A 252Cf source, shielded from the detector, may be placed in the bottom section of the sonde for anlysis by measurement of neutron-activation or neutron-capture gamma rays. Stability of the cryostat with changing hydrostatic pressure, absence of vibration, lack of need for power to the cryostat during operation, and freedom of orientation make the method desirable for borehole, undersea, space, and some laboratory applications. ?? 1972.

Californium Recovery from Palladium Wire

DOE Office of Scientific and Technical Information (OSTI.GOV)

Burns, Jon D.

2014-08-01

The recovery of 252Cf from palladium- 252Cf cermet wires was investigated to determine the feasibility of implementing it into the cermet wire production operation at Oak Ridge National Laboratory’s Radiochemical Engineering Development Center. The dissolution of Pd wire in 8 M HNO 3 and trace amounts of HCl was studied at both ambient and elevated temperatures. These studies showed that it took days to dissolve the wire at ambient temperature and only 2 hours at 60°C. Adjusting the ratio of the volume of solvent to the mass of the wire segment showed little change in the kinetics of dissolution, whichmore » ranged from 0.176 mL/mg down to 0.019 mL/mg. A successful chromatographic separation of 153Gd, a surrogate for 252Cf, from Pd was demonstrated using AG 50x8 cation exchange resin with a bed volume of 0.5 mL and an internal diameter of 0.8 cm.« less

Measurement of the 23Na(n,2n) cross section in 235U and 252Cf fission neutron spectra

NASA Astrophysics Data System (ADS)

Košťál, Michal; Schulc, Martin; Rypar, Vojtěch; Losa, Evžen; Švadlenková, Marie; Baroň, Petr; Jánský, Bohumil; Novák, Evžen; Mareček, Martin; Uhlíř, Jan

2017-09-01

The presented paper aims to compare the calculated and experimental reaction rates of 23Na(n,2n)22Na in a well-defined reactor spectra and in the spontaneous fission spectrum of 252Cf. The experimentally determined reaction rate, derived using gamma spectroscopy of irradiated NaF sample, is used for average cross section determination.Estimation of this cross-section is important as it is included in International Reactor Dosimetry and Fusion File and is also relevant to the correct estimation of long-term activity of Na coolant in Sodium Fast Reactors. The calculations were performed with the MCNP6 code using ENDF/B-VII.0, JEFF-3.1, JEFF-3.2, JENDL-3.3, JENDL-4, ROSFOND-2010, CENDL-3.1 and IRDFF nuclear data libraries. In the case of reactor spectrum, reasonable agreement was not achieved with any library. However, in the case of 252Cf spectrum agreement was achieved with IRDFF, JEFF-3.1 and JENDL libraries.

Evaluation of neutron sources for ISAGE-in-situ-NAA for a future lunar mission.

PubMed

Li, X; Breitkreutz, H; Burfeindt, J; Bernhardt, H-G; Trieloff, M; Hopp, J; Jessberger, E K; Schwarz, W H; Hofmann, P; Hiesinger, H

2011-11-01

For a future Moon landing, a concept for an in-situ NAA involving age determination using the (40)Ar-(39)Ar method is developed. A neutron source (252)Cf is chosen for sample irradiation on the Moon. A special sample-in-source irradiation geometry is designed to provide a homogeneous distribution of neutron flux at the irradiation position. Using reflector, the neutron flux is likely to increase by almost 200%. Sample age of 1Ga could be determined. Elemental analysis using INAA is discussed. Copyright © 2011 Elsevier Ltd. All rights reserved.

γ -soft Ba 146 and the role of nonaxial shapes at N ≈ 90

DOE PAGES

Mitchell, A. J.; Lister, C. J.; McCutchan, E. A.; ...

2016-01-12

Low-spin states in the neutron-rich, N = 90 nuclide 146Ba were populated following β decay of 146Cs , with the goal of clarifying the development of deformation in barium isotopes through delineation of their nonyrast structures. Fission fragments of 146Cs were extracted from a 1.7-Ci 252Cf source and mass selected using the CAlifornium Rare Ion Breeder Upgrade (CARIBU) facility. Low-energy ions were deposited at the center of a box of thin β detectors, surrounded by a highly efficient high-purity Ge array. The new 146Ba decay scheme now contains 31 excited levels extending up to ~2.5 MeV excitation energy, double whatmore » was previously known. These data are compared to predictions from the interacting boson approximation (IBA) model. It appears that the abrupt shape change found at N = 90 in Sm and Gd is much more gradual in Ba and Ce, due to an enhanced role of the γ degree of freedom.« less

Historical Review of Californium-252 Discovery and Development

DOE R&D Accomplishments Database

Stoddard, D. H.

1985-01-01

This paper discusses the discovery and history of californium 252. This isotope may be synthesized by irradiating plutonium 239, plutonium 242, americium 243, or curium 244 with neutrons in a nuclear reactor. Various experiments and inventions involving Cf conducted at the Savannah River Plant are discussed. The evolution of radiotherapy using californium 252 is reviewed. (PLG)

Pre-experiment testing of the Multi Channel Systems 16-channel preamplifier CPA16

DOE Office of Scientific and Technical Information (OSTI.GOV)

Patin, J B; Stoyer, M A; Moody, K J

2003-11-03

The 16-channel preamplifier model CPA16 from Multi Channel Systems was studied. The CPA16 preamplifier/amplifier module is a candidate to be used as the preamplifiers and amplifiers for the focal plane detectors of the Mass Analyzer of Super Heavy Atoms (MASHA). The equipment used to test the CPA16, the results of testing the CPA16 with a pulser, a mixed {sup 229}Th/{sup 148}Gd source and a {sup 252}Cf source, and a summary of the results will be presented.

Fission-neutrons source with fast neutron-emission timing

NASA Astrophysics Data System (ADS)

Rusev, G.; Baramsai, B.; Bond, E. M.; Jandel, M.

2016-05-01

A neutron source with fast timing has been built to help with detector-response measurements. The source is based on the neutron emission from the spontaneous fission of 252Cf. The time is provided by registering the fission fragments in a layer of a thin scintillation film with a signal rise time of 1 ns. The scintillation light output is measured by two silicon photomultipliers with rise time of 0.5 ns. Overall time resolution of the source is 0.3 ns. Design of the source and test measurements using it are described. An example application of the source for determining the neutron/gamma pulse-shape discrimination by a stilbene crystal is given.

The neutron-gamma Feynman variance to mean approach: Gamma detection and total neutron-gamma detection (theory and practice)

NASA Astrophysics Data System (ADS)

Chernikova, Dina; Axell, Kåre; Avdic, Senada; Pázsit, Imre; Nordlund, Anders; Allard, Stefan

2015-05-01

Two versions of the neutron-gamma variance to mean (Feynman-alpha method or Feynman-Y function) formula for either gamma detection only or total neutron-gamma detection, respectively, are derived and compared in this paper. The new formulas have particular importance for detectors of either gamma photons or detectors sensitive to both neutron and gamma radiation. If applied to a plastic or liquid scintillation detector, the total neutron-gamma detection Feynman-Y expression corresponds to a situation where no discrimination is made between neutrons and gamma particles. The gamma variance to mean formulas are useful when a detector of only gamma radiation is used or when working with a combined neutron-gamma detector at high count rates. The theoretical derivation is based on the Chapman-Kolmogorov equation with the inclusion of general reactions and corresponding intensities for neutrons and gammas, but with the inclusion of prompt reactions only. A one energy group approximation is considered. The comparison of the two different theories is made by using reaction intensities obtained in MCNPX simulations with a simplified geometry for two scintillation detectors and a 252Cf-source. In addition, the variance to mean ratios, neutron, gamma and total neutron-gamma are evaluated experimentally for a weak 252Cf neutron-gamma source, a 137Cs random gamma source and a 22Na correlated gamma source. Due to the focus being on the possibility of using neutron-gamma variance to mean theories for both reactor and safeguards applications, we limited the present study to the general analytical expressions for Feynman-alpha formulas.

Cross-correlation measurements with the EJ-299-33 plastic scintillator

NASA Astrophysics Data System (ADS)

Bourne, Mark M.; Whaley, Jeff; Dolan, Jennifer L.; Polack, John K.; Flaska, Marek; Clarke, Shaun D.; Tomanin, Alice; Peerani, Paolo; Pozzi, Sara A.

2015-06-01

New organic-plastic scintillation compositions have demonstrated pulse-shape discrimination (PSD) of neutrons and gamma rays. We present cross-correlation measurements of 252Cf and mixed uranium-plutonium oxide (MOX) with the EJ-299-33 plastic scintillator. For comparison, equivalent measurements were performed with an EJ-309 liquid scintillator. Offline, digital PSD was applied to each detector. These measurements show that EJ-299-33 sacrifices a factor of 5 in neutron-neutron efficiency relative to EJ-309, but could still utilize the difference in neutron-neutron efficiency and neutron single-to-double ratio to distinguish 252Cf from MOX. These measurements were modeled with MCNPX-PoliMi, and MPPost was used to convert the detailed collision history into simulated cross-correlation distributions. MCNPX-PoliMi predicted the measured 252Cf cross-correlation distribution for EJ-309 to within 10%. Greater photon uncertainty in the MOX sample led to larger discrepancy in the simulated MOX cross-correlation distribution. The modeled EJ-299-33 plastic also gives reasonable agreement with measured cross-correlation distributions, although the MCNPX-PoliMi model appears to under-predict the neutron detection efficiency.

Angular correlations in the prompt neutron emission in spontaneous fission of 252Cf

NASA Astrophysics Data System (ADS)

Kopatch, Yuri; Chietera, Andreina; Stuttgé, Louise; Gönnenwein, Friedrich; Mutterer, Manfred; Gagarski, Alexei; Guseva, Irina; Dorvaux, Olivier; Hanappe, Francis; Hambsch, Franz-Josef

2017-09-01

An experiment aiming at the detailed investigation of angular correlations in the neutron emission from spontaneous fission of 252Cf has been performed at IPHC Strasbourg using the angle-sensitive double ionization chamber CODIS for measuring fission fragments and a set of 60 DEMON scintillator counters for neutron detection. The main aim of the experiment is to search for an anisotropy of neutron emission in the center-of-mass system of the fragments. The present status of the data analysis and the full Monte-Carlo simulation of the experiment are reported in the present paper.

Costs of bronchoalveolar lavage-directed therapy in the first 5 years of life for children with cystic fibrosis.

PubMed

Moodie, Marj; Lal, Anita; Vidmar, Suzanna; Armstrong, David S; Byrnes, Catherine A; Carlin, John B; Cheney, Joyce; Cooper, Peter J; Grimwood, Keith; Robertson, Colin F; Tiddens, Harm A; Wainwright, Claire E

2014-09-01

To determine whether bronchoalveolar lavage (BAL)-directed therapy for infants and young children with cystic fibrosis (CF), rather than standard therapy, was justified on the grounds of a decrease in average costs and whether the use of BAL reduced treatment costs associated with hospital admissions. Costs were assessed in a randomized controlled trial conducted in Australia and New Zealand on infants diagnosed with CF after newborn screening and assigned to receive either BAL-directed or standard therapy until they reached 5 years of age. A health care funder perspective was adopted. Resource use measurement was based on standardized data collection forms administered for patients across all sites. Unit costs were obtained primarily from government schedules. Mean costs per child during the study period were Australian dollars (AUD)92 860 in BAL-directed therapy group and AUD90 958 in standard therapy group (mean difference AUD1902, 95% CI AUD-27 782 to 31 586, P = .90). Mean hospital costs per child during the study period were AUD57 302 in the BAL-directed therapy group and AUD66 590 in the standard therapy group (mean difference AUD-9288; 95% CI AUD-35 252 to 16 676, P = .48). BAL-directed therapy did not result in either lower mean hospital admission costs or mean costs overall compared with managing patients with CF by a standard protocol based upon clinical features and oropharyngeal culture results alone. Following on our previous findings that BAL-directed treatment offers no clinical advantage over standard therapy at age 5 years, flexible bronchoscopy with BAL cannot be recommended for the routine management of preschool children with CF on the basis of overall cost savings. Copyright © 2014 Elsevier Inc. All rights reserved.

Spectral correction factors for conventional neutron dosemeters used in high-energy neutron environments.

PubMed

Lee, K W; Sheu, R J

2015-04-01

High-energy neutrons (>10 MeV) contribute substantially to the dose fraction but result in only a small or negligible response in most conventional moderated-type neutron detectors. Neutron dosemeters used for radiation protection purpose are commonly calibrated with (252)Cf neutron sources and are used in various workplace. A workplace-specific correction factor is suggested. In this study, the effect of the neutron spectrum on the accuracy of dose measurements was investigated. A set of neutron spectra representing various neutron environments was selected to study the dose responses of a series of Bonner spheres, including standard and extended-range spheres. By comparing (252)Cf-calibrated dose responses with reference values based on fluence-to-dose conversion coefficients, this paper presents recommendations for neutron field characterisation and appropriate correction factors for responses of conventional neutron dosemeters used in environments with high-energy neutrons. The correction depends on the estimated percentage of high-energy neutrons in the spectrum or the ratio between the measured responses of two Bonner spheres (the 4P6_8 extended-range sphere versus the 6″ standard sphere). © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

A Complex Inoculant of N2-Fixing, P- and K-Solubilizing Bacteria from a Purple Soil Improves the Growth of Kiwifruit (Actinidia chinensis) Plantlets

PubMed Central

Shen, Hong; He, Xinhua; Liu, Yiqing; Chen, Yi; Tang, Jianming; Guo, Tao

2016-01-01

Limited information is available if plant growth promoting bacteria (PGPB) can promote the growth of fruit crops through improvements in soil fertility. This study aimed to evaluate the capacity of PGPB, identified by phenotypic and 16S rRNA sequencing from a vegetable purple soil in Chongqing, China, to increase soil nitrogen (N), phosphorus (P), and potassium (K) availability and growth of kiwifruit (Actinidia chinensis). In doing so, three out of 17 bacterial isolates with a high capacity of N2-fixation (Bacillus amyloliquefaciens, XD-N-3), P-solubilization (B. pumilus, XD-P-1) or K-solubilization (B. circulans, XD-K-2) were mixed as a complex bacterial inoculant. A pot experiment then examined its effects of this complex inoculant on soil microflora, soil N2-fixation, P- and K-solubility and kiwifruit growth under four treatments. These treatments were (1) no-fertilizer and no-bacterial inoculant (Control), (2) no-bacterial inoculant and a full-rate of chemical NPK fertilizer (CF), (3) the complex inoculant (CI), and (4) a half-rate CF and full CI (1/2CF+CI). Results indicated that significantly greater growth of N2-fixing, P- and K-solubilizing bacteria among treatments ranked from greatest to least as under 1/2CF+CI ≈ CI > CF ≈ Control. Though generally without significant treatment differences in soil total N, P, or K, significantly greater soil available N, P, or K among treatments was, respectively, patterned as under 1/2CF+CI ≈ CI > CF ≈ Control, under 1/2CF+CI > CF > CI > Control or under 1/2CF+CI > CF ≈ CI > Control, indicating an improvement of soil fertility by this complex inoculant. In regards to plant growth, significantly greater total plant biomass and total N, P, and K accumulation among treatments were ranked as 1/2CF+CI ≈ CI > CF > Control. Additionally, significantly greater leaf polyphenol oxidase activity ranked as under CF > 1/2CF+CI ≈ Control ≈ CI, while leaf malondialdehyde contents as under Control > CI ≈ CF > 1/2CF+CI. In short, the applied complex inoculant is able to improve available soil N, P, and K and kiwifruit growth. These results demonstrate the potential of using a complex bacterial inoculant for promoting soil fertility and plant growth. PMID:27445991

A Complex Inoculant of N2-Fixing, P- and K-Solubilizing Bacteria from a Purple Soil Improves the Growth of Kiwifruit (Actinidia chinensis) Plantlets.

PubMed

Shen, Hong; He, Xinhua; Liu, Yiqing; Chen, Yi; Tang, Jianming; Guo, Tao

2016-01-01

Limited information is available if plant growth promoting bacteria (PGPB) can promote the growth of fruit crops through improvements in soil fertility. This study aimed to evaluate the capacity of PGPB, identified by phenotypic and 16S rRNA sequencing from a vegetable purple soil in Chongqing, China, to increase soil nitrogen (N), phosphorus (P), and potassium (K) availability and growth of kiwifruit (Actinidia chinensis). In doing so, three out of 17 bacterial isolates with a high capacity of N2-fixation (Bacillus amyloliquefaciens, XD-N-3), P-solubilization (B. pumilus, XD-P-1) or K-solubilization (B. circulans, XD-K-2) were mixed as a complex bacterial inoculant. A pot experiment then examined its effects of this complex inoculant on soil microflora, soil N2-fixation, P- and K-solubility and kiwifruit growth under four treatments. These treatments were (1) no-fertilizer and no-bacterial inoculant (Control), (2) no-bacterial inoculant and a full-rate of chemical NPK fertilizer (CF), (3) the complex inoculant (CI), and (4) a half-rate CF and full CI (1/2CF+CI). Results indicated that significantly greater growth of N2-fixing, P- and K-solubilizing bacteria among treatments ranked from greatest to least as under 1/2CF+CI ≈ CI > CF ≈ Control. Though generally without significant treatment differences in soil total N, P, or K, significantly greater soil available N, P, or K among treatments was, respectively, patterned as under 1/2CF+CI ≈ CI > CF ≈ Control, under 1/2CF+CI > CF > CI > Control or under 1/2CF+CI > CF ≈ CI > Control, indicating an improvement of soil fertility by this complex inoculant. In regards to plant growth, significantly greater total plant biomass and total N, P, and K accumulation among treatments were ranked as 1/2CF+CI ≈ CI > CF > Control. Additionally, significantly greater leaf polyphenol oxidase activity ranked as under CF > 1/2CF+CI ≈ Control ≈ CI, while leaf malondialdehyde contents as under Control > CI ≈ CF > 1/2CF+CI. In short, the applied complex inoculant is able to improve available soil N, P, and K and kiwifruit growth. These results demonstrate the potential of using a complex bacterial inoculant for promoting soil fertility and plant growth.

Combined liquid chromatography-mass spectrometry for trace analysis of pharmaceuticals

NASA Astrophysics Data System (ADS)

Schmidt, Lothar; Danigel, Harald; Jungclas, Hartmut

1982-07-01

A 252Cf-plasma desorption mass spectrometer (PDMS) for the analysis of thin layers from nonvolatile organic samples has been set up to be combined with a liquid chromatograph. A novel interface performs the direct inlet of the liquid sample through a capillary into the vacuum system of the spectrometer. Samples of drugs are periodically collected, transferred to the ion source and analysed using a rotating disk. This on-line sample preparation has been tested for three antiarrhythmic drugs using various solvents and mixtures.

A Comparison of Neutron-Based Non-Destructive Assessment Methods for Chemical Warfare Materiel and High Explosives

DOE Office of Scientific and Technical Information (OSTI.GOV)

E.H. Seabury; D.L. Chichester; C.J. Wharton

2008-08-01

Prompt Gamma Neutron Activation Analysis (PGNAA) systems employ neutrons as a probe to interrogate items, e.g. chemical warfare materiel-filled munitions. The choice of a neutron source in field-portable systems is determined by its ability to excite nuclei of interest, operational concerns such as radiological safety and ease-of-use, and cost. Idaho National Laboratory’s PINS Chemical Assay System has traditionally used a Cf-252 isotopic neutron source, but recently a Deuterium-Tritium (DT) Electronic Neutron Generator (ENG) has been tested as an alternate neutron source. This paper presents the results of using both of these neutron sources to interrogate chemical warfare materiel (CWM) andmore » high explosive (HE) filled munitions.« less

A Comparison of Neutron-Based Non-Destructive Assessment Methods for Chemical Warfare Material and High Explosives

DOE Office of Scientific and Technical Information (OSTI.GOV)

Seabury, E. H.; Chichester, D. L.; Wharton, C. J.

2009-03-10

Prompt Gamma Neutron Activation Analysis (PGNAA) systems employ neutrons as a probe to interrogate items, e.g. chemical warfare materiel-filled munitions. The choice of a neutron source in field-portable systems is determined by its ability to excite nuclei of interest, operational concerns such as radiological safety and ease-of-use, and cost. Idaho National Laboratory's PINS Chemical Assay System has traditionally used a {sup 252}Cf isotopic neutron source, but recently a deuterium-tritium (DT) electronic neutron generator (ENG) has been tested as an alternate neutron source. This paper presents the results of using both of these neutron sources to interrogate chemical warfare materiel (CWM)more » and high explosive (HE) filled munitions.« less

Dose profile modeling of Idaho National Laboratory's active neutron interrogation laboratory.

PubMed

Chichester, D L; Seabury, E H; Zabriskie, J M; Wharton, J; Caffrey, A J

2009-06-01

A new laboratory has been commissioned at Idaho National Laboratory for performing active neutron interrogation research and development. The facility is designed to provide radiation shielding for deuterium-tritium (DT) fusion (14.1 MeV) neutron generators (2 x 10(8) n/s), deuterium-deuterium (DD) fusion (2.5 MeV) neutron generators (1 x 10(7) n/s), and (252)Cf spontaneous fission neutron sources (6.96 x 10(7) n/s, 30 microg). Shielding at the laboratory is comprised of modular concrete shield blocks 0.76 m thick with tongue-in-groove features to prevent radiation streaming, arranged into one small and one large test vault. The larger vault is designed to allow operation of the DT generator and has walls 3.8m tall, an entrance maze, and a fully integrated electrical interlock system; the smaller test vault is designed for (252)Cf and DD neutron sources and has walls 1.9 m tall and a simple entrance maze. Both analytical calculations and numerical simulations were used in the design process for the building to assess the performance of the shielding walls and to ensure external dose rates are within required facility limits. Dose rate contour plots have been generated for the facility to visualize the effectiveness of the shield walls and entrance mazes and to illustrate the spatial profile of the radiation dose field above the facility and the effects of skyshine around the vaults.

DOSE PROFILE MODELING OF IDAHO NATIONAL LABORATORY’S ACTIVE NEUTRON INTERROGATION TEST FACILITY

DOE Office of Scientific and Technical Information (OSTI.GOV)

D. L. Chichester; E. H. Seabury; J. M. Zabriskie

2009-06-01

A new research and development laboratory has been commissioned at Idaho National Laboratory for performing active neutron interrogation research and development. The facility is designed to provide radiation shielding for DT fusion (14.1 MeV) neutron generators (2 x 108 neutrons per second), DD fusion (2.5 MeV) neutron generators (up to 2 x 106 neutrons per second), and 252Cf spontaneous fission neutron sources (6.7 x 107 neutrons per second, 30 micrograms). Shielding at the laboratory is comprised of modular concrete shield blocks 0.76 m thick with tongue-in-groove features to prevent radiation streaming, arranged into one small and one large test vault.more » The larger vault is designed to allow operation of the DT generator and has walls 3.8 m tall, an entrance maze, and a fully integrated electrical interlock system; the smaller test vault is designed for 252Cf and DD neutron sources and has walls 1.9 m tall and a simple entrance maze. Both analytical calculations and numerical simulations were used in the design process for the building to assess the performance of the shielding walls and to ensure external dose rates are within required facility limits. Dose rate contour plots have been generated for the facility to visualize the effectiveness of the shield wall and entrance maze and to illustrate the spatial profile of the radiation dose field above the facility and the effects of skyshine around the vaults.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lintereur, Azaree T.; Ely, James H.; Stave, Jean A.

The goal of this was research effort was to test the ability of two poly vinyltoluene research samples to produce recordable, distinguishable signals in response to gamma rays and neutrons. Pulse shape discrimination was performed to identify if the signal was generated by a gamma ray or a neutron. A standard figure of merit for pulse shape discrimination was used to quantify the gamma-neutron pulse separation. Measurements were made with gamma and neutron sources with and without shielding. The best figure of merit obtained was 1.77; this figure of merit was achieved with the first sample in response to anmore » un-moderated 252Cf source shielded with 5.08 cm of lead.« less

Californium-252 Brachytherapy Combined With External-Beam Radiotherapy for Cervical Cancer: Long-Term Treatment Results

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lei Xin; Qian Chengyuan; Qing Yi

Purpose: To observe, by retrospective analysis, the curative effects and complications due to californium-252 ({sup 252}Cf) neutron intracavitary brachytherapy (ICBT) combined with external-beam radiotherapy (EBRT) in the treatment of cervical cancer. Methods and Materials: From February 1999 to December 2007, 696 patients with cervical cancer (Stages IB to IIIB) were treated with {sup 252}Cf-ICBT in combination of EBRT. Of all, 31 patients were at Stage IB, 104 at IIA, 363 at IIB, 64 at IIIA, and 134 at IIIB. Californium-252 ICBT was delivered at 7-12 Gy per insertion per week, with a total dose of 29-45 Gy to reference pointmore » A in three to five insertions. The whole pelvic cavity was treated with 8-MV X-ray external irradiation at 2 Gy per fraction, four times per week. After 16-38 Gy of external irradiation, the center of the whole pelvic field was blocked with a 4-cm-wide lead shield, with a total external irradiation dose of 44-56 Gy. The total treatment course was 5 to 6 weeks. Results: Overall survival rate at 3 and 5 years for all patients was 76.0% and 64.9%, respectively. Disease-free 3- and 5-year survival rates of patients were 71.2% and 58.4%, respectively. Late complications included vaginal contracture and adhesion, radiation proctitis, radiation cystitis, and inflammatory bowel, which accounted for 5.8%, 7.1%, 6.2%, and 4.9%, respectively. Univariate analysis results showed significant correlation of stage, age, histopathologic grade, and lymph node status with overall survival. Cox multiple regression analysis showed that the independent variables were stage, histopathologic grade, tumor size, and lymphatic metastasis in all patients. Conclusion: Results of this series suggest that the combined use of {sup 252}Cf-ICBT with EBRT is an effective method for treatment of cervical cancer.« less

Project Plan 7930 Cell G PaR Remote Handling System Replacement

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kinney, Kathryn A

2009-10-01

For over 40 years the US Department of Energy (DOE) and its predecessors have made Californium-252 ({sup 252}Cf) available for a wide range of industries including medical, nuclear fuels, mining, military and national security. The Radiochemical Engineering Development Center (REDC) located within the Oak Ridge National Laboratory (ORNL) processes irradiated production targets from the High Flux Isotope Reactor (HFIR). Operations in Building 7930, Cell G provide over 70% of the world's demand for {sup 252}Cf. Building 7930 was constructed and equipped in the mid-1960s. Current operations for {sup 252}Cf processing in Building 7930, Cell G require use of through-the-wall manipulatorsmore » and the PaR Remote Handling System. Maintenance and repairs for the manipulators is readily accomplished by removal of the manipulator and relocation to a repair shop where hands-on work can be performed in glove boxes. Contamination inside cell G does not currently allow manned entry and no provisions were created for a maintenance area inside the cell. There has been no maintenance of the PaR system or upgrades, leaving operations vulnerable should the system have a catastrophic failure. The Cell G PaR system is currently being operated in a run to failure mode. As the manipulator is now 40+ years old there is significant risk in this method of operation. In 2006 an assessment was completed that resulted in recommendations for replacing the manipulator operator control and power centers which are used to control and power the PaR manipulator in Cell G. In mid-2008 the chain for the bridge drive failed and subsequent examinations indicated several damaged links (see Figure 1). To continue operations the PaR manipulator arm is being used to push and pull the bridge as a workaround. A retrieval tool was fabricated, tested and staged inside Cell G that will allow positioning of the bridge and manipulator arm for removal from the cell should the PaR system completely fail. A fully functioning and reliable Par manipulator arm is necessary for uninterrupted {sup 252}Cf operations; a fully-functioning bridge is needed for the system to function as intended.« less

Detecting fast and thermal neutrons with a boron loaded liquid scintillator, EJ-339A.

PubMed

Pino, F; Stevanato, L; Cester, D; Nebbia, G; Sajo-Bohus, L; Viesti, G

2014-09-01

A commercial boron-loaded liquid scintillator EJ-339 A was studied, using a (252)Cf source with/without polyethylene moderator, to examine the possibility of discriminating slow-neutron induced events in (10)B from fast-neutron events, resulting from proton recoils, and gamma-ray events. Despite the strong light quenching associated with neutron induced events in (10)B, correct classification of these events is shown to be possible with the aid of digital signal processing. Copyright © 2014 Elsevier Ltd. All rights reserved.

Evaluation of radioisotope tracer and activation analysis techniques for contamination monitoring in space environment simulation chambers

NASA Technical Reports Server (NTRS)

Smathers, J. B.; Kuykendall, W. E., Jr.; Wright, R. E., Jr.; Marshall, J. R.

1973-01-01

Radioisotope measurement techniques and neutron activation analysis are evaluated for use in identifying and locating contamination sources in space environment simulation chambers. The alpha range method allows the determination of total contaminant concentration in vapor state and condensate state. A Cf-252 neutron activation analysis system for detecting oils and greases tagged with stable elements is described. While neutron activation analysis of tagged contaminants offers specificity, an on-site system is extremely costly to implement and provides only marginal detection sensitivity under even the most favorable conditions.

Octupole Deformation Bands of πh11/2 in Neutron-Rich 145,147La Nuclei

NASA Astrophysics Data System (ADS)

Zhu, Sheng-jiang; S, Zhu J.; Wang, Mu-ge; J, Hamilton H.; A, Ramayya V.; B, Babu R. S.; W, Ma C.; Long, Gui-lu; Zhu, Ling-yan; Li, Ming; A, Sakhaee; Gan, Cui-yun; Yang, Li-ming; J, Komicki; J, Cole D.; R, Aryaeinejad; M, Drigert W.; J, Rasmussen O.; M, Stoyer A.; S, Chu Y.; K, Gregorich E.; M, Mohar F.; S, Prussin G.; I, Lee Y.; Yu, Oganessian Ts; G, Ter-Akopian M.; A, Daniel V.

1999-03-01

Octupole deformation bands built on πh11/2 orbital in neutron-rich odd-Z 145,147La nuclei have been investigated by measuring the prompt γ-rays emitted from the 252Cf source. The alternating parity band structures and strong E1 transitions observed between negative- and positive-parity bands in both nuclei indicate the octupole deformation enhanced by the h11/2 single proton coupling. According to observed energy displacements the octupole deformation becomes stable at the intermediate spin states.

Neutron detection with a NaI spectrometer using high-energy photons

NASA Astrophysics Data System (ADS)

Holm, Philip; Peräjärvi, Kari; Sihvonen, Ari-Pekka; Siiskonen, Teemu; Toivonen, Harri

2013-01-01

Neutrons can be indirectly detected by high-energy photons. The performance of a 4″×4″×16″ NaI portal monitor was compared to a 3He-based portal monitor with a comparable cross-section of the active volume. Measurements were performed with bare and shielded 252Cf and AmBe sources. With an optimum converter and moderator structure for the NaI detector, the detection efficiencies and minimum detectable activities of the portal monitors were similar. The NaI portal monitor preserved its detection efficiency much better with shielded sources, making the method very interesting for security applications. For heavily shielded sources, the NaI detector was 2-3 times more sensitive than the 3He-based detector.

Radioactivity in atomic-bomb samples from exposure to environmental neutrons.

PubMed

Endo, S; Shizuma, K; Tanaka, K; Ishikawa, M; Rühm, W; Egbert, S D; Hoshi, M

2007-12-01

For about one decade, activation measurements performed on environmental samples from a distance larger than 1 km from the hypocenter of the atomic-bomb explosion over Hiroshima suggested much higher thermal neutron fluences to the survivors than predicted. This caused concern among the radiation protection community and prompted a complete re-evaluation of all aspects of survivor dosimetry. While it was shown recently that secondary neutrons from cosmic radiation and other sources have probably been the reason for the high measured concentrations of the long-lived radioisotope 36Cl in these samples, the source for high measured concentrations of the short-lived radionuclides 152Eu and 60Co has not yet been investigated in detail. In order to quantify the production of 152Eu and 60Co in environmental samples by secondary neutrons from cosmic radiation, thermal neutron fluxes were measured by means of a He gas proportional counter in various buildings where these samples had been and still are being stored. Because a 252Cf neutron source has been operated occasionally close to one of the sample storage rooms, additional neutron flux measurements were carried out when the neutron source was in operation. The thermal neutron fluxes measured ranged from 0.00017 to 0.00093 n cm(-2) s(-1) and depended on the floor number of the investigated building. Based on the measured neutron fluxes, the specific activities from the reactions 151Eu(n,gamma)152Eu and 59Co(n,gamma)60Co in the atomic-bomb samples were estimated to be 7.9 mBq g(-1) Eu and 0.27 mBq g(-1) Co, respectively, in saturation. These activities are much lower than those recently measured in samples that had been exposed to atomic-bomb neutrons. It is therefore concluded that environmental and moderated 252Cf neutrons are not the source for the high activities that had been measured in these samples.

Prompt fission gamma-ray emission spectral data for 239Pu(n,f) using fast directional neutrons from the LICORNE neutron source

NASA Astrophysics Data System (ADS)

Qi, L.; Wilson, J. N.; Lebois, M.; Al-Adili, A.; Chatillon, A.; Choudhury, D.; Gatera, A.; Georgiev, G.; Göök, A.; Laurent, B.; Maj, A.; Matea, I.; Oberstedt, A.; Oberstedt, S.; Rose, S. J.; Schmitt, C.; Wasilewska, B.; Zeiser, F.

2018-03-01

Prompt fission gamma-ray spectra (PFGS) have been measured for the 239Pu(n,f) reaction using fast neutrons at Ēn=1.81 MeV produced by the LICORNE directional neutron source. The setup makes use of LaBr3 scintillation detectors and PARIS phoswich detectors to measure the emitted prompt fission gamma rays (PFG). The mean multiplicity, average total energy release per fission and average energy of photons are extracted from the unfolded PFGS. These new measurements provide complementary information to other recent work on thermal neutron induced fission of 239Pu and spontaneous fission of 252Cf.

Response of CMS avalanche photo-diodes to low energy neutrons

NASA Astrophysics Data System (ADS)

Brown, R. M.; Deiters, K.; Ingram, Q.; Renker, D.

2012-12-01

The response of the Avalanche Photo-diodes (APDs) installed in the CMS detector at the LHC to neutrons from 241AmBe and 252Cf sources is reported. Signals in size equivalent to those of up to 106 photo-electrons with the nominal APD gain are observed. Measurements with an APD with the protective epoxy coating removed and with the source placed behind the APD show that there is an important response due to recoil protons from neutron interactions with the hydrogen in the epoxy, in addition to signals from neutron interactions with the silicon of the diode. The effective gain of these signals is much smaller than the diode's nominal gain.

Benchmarking Data for the Proposed Signature of Used Fuel Casks

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rauch, Eric Benton

2016-09-23

A set of benchmarking measurements to test facets of the proposed extended storage signature was conducted on May 17, 2016. The measurements were designed to test the overall concept of how the proposed signature can be used to identify a used fuel cask based only on the distribution of neutron sources within the cask. To simulate the distribution, 4 Cf-252 sources were chosen and arranged on a 3x3 grid in 3 different patterns and raw neutron totals counts were taken at 6 locations around the grid. This is a very simplified test of the typical geometry studied previously in simulationmore » with simulated used nuclear fuel.« less

Using Cf-252 for single event upset testing

NASA Astrophysics Data System (ADS)

Howard, J. W.; Chen, R.; Block, R. C.; Becker, M.; Costantine, A. G.; Smith, L. S.; Soli, G. A.; Stauber, M. C.

An improved system using Cf-252 and associated nuclear instrumentation has been used to determine single event upset (SEU) cross section versus linear energy transfer (LET) curve for several static random access memory (SRAM) devices. Through the use of a thin-film scintillator, providing energy information on each fission fragment, individual SEU's and ion energy can be associated to calculate the cross section curves. Results are presented from tests of several SRAM's over the 17-43 MeV-cm squared/mg LET range. Values obtained for SEU cross sections and LET thresholds are in good agreement with the results from accelerator testing. The equipment is described, the theory of thin-film scintillation detector response is summarized, experimental procedures are reviewed, and the test results are discussed.

Fast-neutron, coded-aperture imager

NASA Astrophysics Data System (ADS)

Woolf, Richard S.; Phlips, Bernard F.; Hutcheson, Anthony L.; Wulf, Eric A.

2015-06-01

This work discusses a large-scale, coded-aperture imager for fast neutrons, building off a proof-of concept instrument developed at the U.S. Naval Research Laboratory (NRL). The Space Science Division at the NRL has a heritage of developing large-scale, mobile systems, using coded-aperture imaging, for long-range γ-ray detection and localization. The fast-neutron, coded-aperture imaging instrument, designed for a mobile unit (20 ft. ISO container), consists of a 32-element array of 15 cm×15 cm×15 cm liquid scintillation detectors (EJ-309) mounted behind a 12×12 pseudorandom coded aperture. The elements of the aperture are composed of 15 cm×15 cm×10 cm blocks of high-density polyethylene (HDPE). The arrangement of the aperture elements produces a shadow pattern on the detector array behind the mask. By measuring of the number of neutron counts per masked and unmasked detector, and with knowledge of the mask pattern, a source image can be deconvolved to obtain a 2-d location. The number of neutrons per detector was obtained by processing the fast signal from each PMT in flash digitizing electronics. Digital pulse shape discrimination (PSD) was performed to filter out the fast-neutron signal from the γ background. The prototype instrument was tested at an indoor facility at the NRL with a 1.8-μCi and 13-μCi 252Cf neutron/γ source at three standoff distances of 9, 15 and 26 m (maximum allowed in the facility) over a 15-min integration time. The imaging and detection capabilities of the instrument were tested by moving the source in half- and one-pixel increments across the image plane. We show a representative sample of the results obtained at one-pixel increments for a standoff distance of 9 m. The 1.8-μCi source was not detected at the 26-m standoff. In order to increase the sensitivity of the instrument, we reduced the fastneutron background by shielding the top, sides and back of the detector array with 10-cm-thick HDPE. This shielding configuration led to a reduction in the background by a factor of 1.7 and thus allowed for the detection and localization of the 1.8 μCi. The detection significance for each source at different standoff distances will be discussed.

Neutron radiative capture methods for surface elemental analysis

USGS Publications Warehouse

Trombka, J.I.; Senftle, F.; Schmadebeck, R.

1970-01-01

Both an accelerator and a 252Cf neutron source have been used to induce characteristic gamma radiation from extended soil samples. To demonstrate the method, measurements of the neutron-induced radiative capture and activation gamma rays have been made with both Ge(Li) and NaI(Tl) detectors, Because of the possible application to space flight geochemical analysis, it is believed that NaI(Tl) detectors must be used. Analytical procedures have been developed to obtain both qualitative and semiquantitative results from an interpretation of the measured NaI(Tl) pulse-height spectrum. Experiment results and the analytic procedure are presented. ?? 1970.

SPECTRAL CORRECTION FACTORS FOR CONVENTIONAL NEUTRON DOSE METERS USED IN HIGH-ENERGY NEUTRON ENVIRONMENTS-IMPROVED AND EXTENDED RESULTS BASED ON A COMPLETE SURVEY OF ALL NEUTRON SPECTRA IN IAEA-TRS-403.

PubMed

Oparaji, U; Tsai, Y H; Liu, Y C; Lee, K W; Patelli, E; Sheu, R J

2017-06-01

This paper presents improved and extended results of our previous study on corrections for conventional neutron dose meters used in environments with high-energy neutrons (En > 10 MeV). Conventional moderated-type neutron dose meters tend to underestimate the dose contribution of high-energy neutrons because of the opposite trends of dose conversion coefficients and detection efficiencies as the neutron energy increases. A practical correction scheme was proposed based on analysis of hundreds of neutron spectra in the IAEA-TRS-403 report. By comparing 252Cf-calibrated dose responses with reference values derived from fluence-to-dose conversion coefficients, this study provides recommendations for neutron field characterization and the corresponding dose correction factors. Further sensitivity studies confirm the appropriateness of the proposed scheme and indicate that (1) the spectral correction factors are nearly independent of the selection of three commonly used calibration sources: 252Cf, 241Am-Be and 239Pu-Be; (2) the derived correction factors for Bonner spheres of various sizes (6"-9") are similar in trend and (3) practical high-energy neutron indexes based on measurements can be established to facilitate the application of these correction factors in workplaces. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Study of the Mo-Ba partition in 252Cf spontaneous fission

NASA Astrophysics Data System (ADS)

Biswas, D. C.; Choudhury, R. K.; Cinausero, M.; Fornal, B.; Shetty, D. V.; Viesti, G.; Fabris, D.; Fioretto, E.; Lunardon, M.; Nebbia, G.; Prete, G.; Bazzacco, D.; DePoli, M.; Napoli, D. R.; Ur, C. A.; Vedovato, G.

Measurements of fission fragment yields and neutron multiplicities have been carried out for the Mo-Ba fragment pairs in the spontaneous fission of 252Cf, using the γ-ray spectroscopy technique to analyze γ-γ-γ coincidence data. Prompt γ -ray multiplicities were also measured as a function of the number of neutrons emitted in the fission process leading to the Mo-Ba partition. We do not observe the enhancement in the yields of events with high neutron emission multiplicity (νn > 7) that has been associated to a second fission mode leading to the production of hyperdeformed Ba fragments, as reported in some earlier studies. The average γ-ray multiplicity is found to be rather weakly dependent on the number of neutrons emitted in the fission process.

The Th17 Pathway in Cystic Fibrosis Lung Disease

PubMed Central

Tan, Hui-Leng; Regamey, Nicolas; Brown, Sarah; Bush, Andrew; Lloyd, Clare M.; Davies, Jane C.

2012-01-01

Rationale Cystic fibrosis (CF) is characterized by bronchoalveolar neutrophilia and submucosal lymphocytosis. We hypothesized that Th17 lymphocytes are part of this submucosal infiltrate. Objectives Quantification and phenotyping of the lymphocytic infiltrate in the bronchial submucosa of patients with CF (n=53, of which 20 were newly diagnosed), non-CF bronchiectasis (n = 17), and healthy control subjects (n = 13). Methods We measured IL-17 levels in bronchoalveolar lavage and CD4+, CD8+, and IL-17+ cell counts in endobronchial biopsies. Correlations were made with infection status and other inflammatory markers. Potential cellular sources of IL-17 were determined by double staining. Measurements and Main Results IL-17+ cell counts (median [interquartile range] cells/mm2) were significantly higher in patients with established CF (205 [115–551]) and non-CF bronchiectasis (245 [183–436]) than in control subjects (53 [12–82]) (P<0.01 for both). Patients with newly diagnosed CF had intermediate counts (171 [91–252]). IL-17–positive CD4+ T cells, γδT cells, natural killer T cells, and neutrophils were identified. Bronchoalveolar lavage IL-17 levels (pg/ml) were highest in established CF (14.6 [2.2–38.4]), low in newly diagnosed CF and control subjects (1.7 [1.7–1.74]; 1.7 [1.7–3]), and intermediate in non-CF bronchiectasis (9.1 [1.7–34] pg/ml) (Kruskal-Wallis P = 0.001). There was a significant correlation between IL-17 and neutrophil counts (P < 0.001, R = 0.6) as well as IL-4 (P < 0.001, R = 0.84). Conclusions Th17 lymphocytes are present in the airway submucosa in CF, even in a young, newly diagnosed group. Other IL-17+ cells include neutrophils, γδ T cells, and natural killer T cells. PMID:21474644

Monte Carlo N-particle simulation of neutron-based sterilisation of anthrax contamination

PubMed Central

Liu, B; Xu, J; Liu, T; Ouyang, X

2012-01-01

Objective To simulate the neutron-based sterilisation of anthrax contamination by Monte Carlo N-particle (MCNP) 4C code. Methods Neutrons are elementary particles that have no charge. They are 20 times more effective than electrons or γ-rays in killing anthrax spores on surfaces and inside closed containers. Neutrons emitted from a 252Cf neutron source are in the 100 keV to 2 MeV energy range. A 2.5 MeV D–D neutron generator can create neutrons at up to 1013 n s−1 with current technology. All these enable an effective and low-cost method of killing anthrax spores. Results There is no effect on neutron energy deposition on the anthrax sample when using a reflector that is thicker than its saturation thickness. Among all three reflecting materials tested in the MCNP simulation, paraffin is the best because it has the thinnest saturation thickness and is easy to machine. The MCNP radiation dose and fluence simulation calculation also showed that the MCNP-simulated neutron fluence that is needed to kill the anthrax spores agrees with previous analytical estimations very well. Conclusion The MCNP simulation indicates that a 10 min neutron irradiation from a 0.5 g 252Cf neutron source or a 1 min neutron irradiation from a 2.5 MeV D–D neutron generator may kill all anthrax spores in a sample. This is a promising result because a 2.5 MeV D–D neutron generator output >1013 n s−1 should be attainable in the near future. This indicates that we could use a D–D neutron generator to sterilise anthrax contamination within several seconds. PMID:22573293

Monte Carlo N-particle simulation of neutron-based sterilisation of anthrax contamination.

PubMed

Liu, B; Xu, J; Liu, T; Ouyang, X

2012-10-01

To simulate the neutron-based sterilisation of anthrax contamination by Monte Carlo N-particle (MCNP) 4C code. Neutrons are elementary particles that have no charge. They are 20 times more effective than electrons or γ-rays in killing anthrax spores on surfaces and inside closed containers. Neutrons emitted from a (252)Cf neutron source are in the 100 keV to 2 MeV energy range. A 2.5 MeV D-D neutron generator can create neutrons at up to 10(13) n s(-1) with current technology. All these enable an effective and low-cost method of killing anthrax spores. There is no effect on neutron energy deposition on the anthrax sample when using a reflector that is thicker than its saturation thickness. Among all three reflecting materials tested in the MCNP simulation, paraffin is the best because it has the thinnest saturation thickness and is easy to machine. The MCNP radiation dose and fluence simulation calculation also showed that the MCNP-simulated neutron fluence that is needed to kill the anthrax spores agrees with previous analytical estimations very well. The MCNP simulation indicates that a 10 min neutron irradiation from a 0.5 g (252)Cf neutron source or a 1 min neutron irradiation from a 2.5 MeV D-D neutron generator may kill all anthrax spores in a sample. This is a promising result because a 2.5 MeV D-D neutron generator output >10(13) n s(-1) should be attainable in the near future. This indicates that we could use a D-D neutron generator to sterilise anthrax contamination within several seconds.

Defense Horizons. Number 38, January 2004. Dirty Bombs: The Threat Revisited

DTIC Science & Technology

2004-01-01

plutonium-238 (238Pu), americium - 241 (241Am), and cali- fornium-252 (252Cf). Types of Damage Deterministic Injuries. Radiation is said to cause...megasources” such as Russian radioisotope thermal generators ( RTGs ) and Gamma-Kolos seed irradiators. By far the most likely route for terrorist...facility or a business or residential district, not just open space . More efficient RDDs relying on other means to disseminate the same amount of

Keno-Nr a Monte Carlo Code Simulating the Californium -252-SOURCE-DRIVEN Noise Analysis Experimental Method for Determining Subcriticality

NASA Astrophysics Data System (ADS)

Ficaro, Edward Patrick

The ^{252}Cf -source-driven noise analysis (CSDNA) requires the measurement of the cross power spectral density (CPSD) G_ {23}(omega), between a pair of neutron detectors (subscripts 2 and 3) located in or near the fissile assembly, and the CPSDs, G_{12}( omega) and G_{13}( omega), between the neutron detectors and an ionization chamber 1 containing ^{252}Cf also located in or near the fissile assembly. The key advantage of this method is that the subcriticality of the assembly can be obtained from the ratio of spectral densities,{G _sp{12}{*}(omega)G_ {13}(omega)over G_{11 }(omega)G_{23}(omega) },using a point kinetic model formulation which is independent of the detector's properties and a reference measurement. The multigroup, Monte Carlo code, KENO-NR, was developed to eliminate the dependence of the measurement on the point kinetic formulation. This code utilizes time dependent, analog neutron tracking to simulate the experimental method, in addition to the underlying nuclear physics, as closely as possible. From a direct comparison of simulated and measured data, the calculational model and cross sections are validated for the calculation, and KENO-NR can then be rerun to provide a distributed source k_ {eff} calculation. Depending on the fissile assembly, a few hours to a couple of days of computation time are needed for a typical simulation executed on a desktop workstation. In this work, KENO-NR demonstrated the ability to accurately estimate the measured ratio of spectral densities from experiments using capture detectors performed on uranium metal cylinders, a cylindrical tank filled with aqueous uranyl nitrate, and arrays of safe storage bottles filled with uranyl nitrate. Good agreement was also seen between simulated and measured values of the prompt neutron decay constant from the fitted CPSDs. Poor agreement was seen between simulated and measured results using composite ^6Li-glass-plastic scintillators at large subcriticalities for the tank of uranyl nitrate. It is believed that the response of these detectors is not well known and is incorrectly modeled in KENO-NR. In addition to these tests, several benchmark calculations were also performed to provide insight into the properties of the point kinetic formulation.

Longevity of Patients With Cystic Fibrosis in 2000 to 2010 and Beyond: Survival Analysis of the Cystic Fibrosis Foundation Patient Registry

PubMed Central

MacKenzie, Todd; Gifford, Alex H.; Sabadosa, Kathryn A.; Quinton, Hebe B.; Knapp, Emily A.; Goss, Christopher H.; Marshall, Bruce C.

2015-01-01

Background Advances in treatments for cystic fibrosis (CF) continue to extend survival. An updated estimate of survival is needed for better prognostication and to anticipate evolving adult care needs. Objective To characterize trends in CF survival between 2000 and 2010 and to project survival for children born and diagnosed with the disease in 2010. Design Registry-based study. Setting 110 Cystic Fibrosis Foundation–accredited care centers in the United States. Patients All patients represented in the Cystic Fibrosis Foundation Patient Registry (CFFPR) between 2000 and 2010. Measurements Survival was modeled with respect to age, age at diagnosis, gender, race or ethnicity, F508del mutation status, and symptoms at diagnosis. Results Between 2000 and 2010, the number of patients in the CFFPR increased from 21 000 to 26 000, median age increased from 14.3 to 16.7 years, and adjusted mortality decreased by 1.8% per year (95% CI, 0.5% to 2.7%). Males had a 19% (CI, 13% to 24%) lower adjusted risk for death than females. Median survival of children born and diagnosed with CF in 2010 is projected to be 37 years (CI, 35 to 39 years) for females and 40 years (CI, 39 to 42 years) for males if mortality remains at 2010 levels and more than 50 years if mortality continues to decrease at the rate observed between 2000 and 2010. Limitations The CFFPR does not include all patients with CF in the United States, and loss to follow-up and missing data were observed. Additional analyses to address these limitations suggest that the survival projections are conservative. Conclusion Children born and diagnosed with CF in the United States in 2010 are expected to live longer than those born earlier. This has important implications for prognostic discussions and suggests that the health care system should anticipate greater numbers of adults with CF. Primary Funding Source Cystic Fibrosis Foundation. PMID:25133359

Apparatus for irradiating a continuously flowing stream of fluid. [For neutron activation analysis

DOEpatents

Speir, L.G.; Adams, E.L.

1982-05-13

An apparatus for irradiating a continuously flowing stream of fluid is disclosed. The apparatus consists of a housing having a spherical cavity and a spherical moderator containing a radiation source positioned within the spherical cavity. The spherical moderator is of lesser diameter than the spherical cavity so as to define a spherical annular volume around the moderator. The housing includes fluid intake and output conduits which open onto the spherical cavity at diametrically opposite positions. Fluid flows through the cavity around the spherical moderator and is uniformly irradiated due to the 4..pi.. radiation geometry. The irradiation source, for example a /sup 252/Cf neutron source, is removable from the spherical moderator through a radial bore which extends outwardly to an opening on the outside of the housing. The radiation source may be routinely removed without interrupting the flow of fluid or breaching the containment of the fluid.

Apparatus for irradiating a continuously flowing stream of fluid

DOEpatents

Speir, Leslie G.; Adams, Edwin L.

1984-01-01

An apparatus for irradiating a continuously flowing stream of fluid is diosed. The apparatus consists of a housing having a spherical cavity and a spherical moderator containing a radiation source positioned within the spherical cavity. The spherical moderator is of lesser diameter than the spherical cavity so as to define a spherical annular volume around the moderator. The housing includes fluid intake and output conduits which open onto the spherical cavity at diametrically opposite positions. Fluid flows through the cavity around the spherical moderator and is uniformly irradiated due to the 4.pi. radiation geometry. The irradiation source, for example a .sup.252 CF neutron source, is removable from the spherical moderator through a radial bore which extends outwardly to an opening on the outside of the housing. The radiation source may be routinely removed without interrupting the flow of fluid or breaching the containment of the fluid.

The relationship between access to and use of dental services following expansion of a primary care service to embrace dental team training.

PubMed

Wanyonyi, K L; Radford, D R; Gallagher, J E

2013-11-01

To investigate changes in the patient population and treatment case-mix within an expanded primary care dental training facility in Southern England. Cross-sectional analysis of patient management system data. Electronic data for patients with a closed/completed treatment plan in the 12-month period prior to, and following, dental service expansion were extracted for analysis (n = 4343). Descriptive analysis involved age, sex, payment status, deprivation status and treatment activity. Logistic regression was used to model the likelihood of treatment involving laboratory constructed devices (crowns, bridges, dentures), in relation to demography and deprivation in each time period. The volume of patients using the service increased by 48.3% (1749 cf 2594). The average age increased from 31.97 (95%CI: 30.8, 32.5) to 36.4 years (95%CI: 35.6, 37.1); greatest increase was in the over 75 years age-group (96%). The patient base became less deprived: patients exempt from payment reduced from 43.2% (n = 755) to 28.6% (n = 741) (P = 0.001) and the mean population deprivation score (IMD) reduced from 24.5 (95%CI: 23.8, 25.2) to 22.3 (95%CI: 21.7, 22.8). The volume and proportion of care involving laboratory constructed devices increased from 8.3% (n = 145) to 15.8% (n = 411) whilst assessments without interventive care decreased (34.5%-26.3%). On a logistic regression, the odds of having treatment involving laboratory constructed devices, increased with increasing age in both time periods 7% (95% CI: 1.06-1.08) and 6% (95% CI: 1.05-1.07) respectively. Furthermore, the odds increased by 38% OR: 1.38 (95% CI: 1.01-1.89) in period 2, for white patients. After adjusting for these effects, the odds of having care that involved laboratory constructed devices were less in period 2 than period 1 (100% cf 43%) for those who were technically exempt from payment (OR = 2.0; 95% CI 1.34 to 2.90 cf, OR = 1.43; 95% CI 1.13-1.81). The patient population altered in relation to age and socio-economic status. The expanded service had greater uptake by older people while users were less likely to be deprived. The expanded service, free at the point of delivery, attracted a higher proportion of patients who would normally have to pay health service charges. The service also showed an increase in treatment case-mix that involved laboratory constructed dental devices. © 2013 The Royal Society for Public Health. Published by Elsevier Ltd. All rights reserved.

Long-term outcomes of children with intermediate sweat chloride values in infancy.

PubMed

Groves, Tyler; Robinson, Paul; Wiley, Veronica; Fitzgerald, Dominic A

2015-06-01

To describe the clinical course of children who have intermediate sweat chloride values on initial screening for cystic fibrosis (CF). We performed a retrospective review of children with intermediate sweat chloride values (raised immunoreactive trypsinogen/1 copy of p.F508del CF mutation on newborn screening (NBS)/sweat chloride value of 30-59 mmol/L) presenting to The Children's Hospital at Westmead over 15 years. Patients with an intermediate sweat chloride evolving to a formal diagnosis of CF (termed "delayed CF") were matched (2:1) with NBS positive patients with CF (termed "NBS positive CF"). Clinical outcomes were compared. Fourteen of 29 (48%, 95% CI 0.3-0.66) patients with intermediate sweat chloride value evolved to a diagnosis of CF and were matched with 28 NBS positive patients with CF. Delayed CF had less pancreatic insufficiency (OR 0.06, 95% CI 0.01-0.44, P = .006), less colonization with nonmucoid Pseudomonas aeruginosa (OR 0.04, 95% CI 0.01-0.38, P = .005), milder obstructive lung disease (forced expiratory volume in 1 second/forced vital capacity ratio), and overall disease severity (Shwachman scores) at 10 years (mean difference 5.93, 95% CI 0.39-11.46, P = .04; mean difference 4.72, 95% CI 0.9-8.53, P = .015, respectively). Nutritional outcomes were better at 2 years for delayed CF but did not persist to later ages. In this cohort, approximately one-half of infants with intermediate sweat chloride value were later diagnosed with CF. The clinical course of delayed CF was milder in some aspects compared with NBS positive CF. These results emphasize the importance of ongoing follow-up of infants with intermediate sweat chloride values. Crown Copyright © 2015. Published by Elsevier Inc. All rights reserved.

Poor recovery from cystic fibrosis pulmonary exacerbations is associated with poor long-term outcomes.

PubMed

Sanders, Don B; Zhao, Qianqian; Li, Zhanhai; Farrell, Philip M

2017-10-01

People with CF treated with IV antibiotics for a pulmonary exacerbation (PEx) frequently fail to recover to baseline FEV 1 . The long-term impact of these events has not been studied. To determine if a patient's spirometric recovery after a PEx is associated with time to next PEx within 1 year, the spirometric recovery after the next PEx, and/or the number of PEx episodes in the next 3 years. We used data from the CF Foundation Patient Registry from 2004 to 2011. We randomly selected one PEx per patient that met inclusion/exclusion criteria. Patients were defined as Non-Responders if their best FEV 1 (in liters) recorded in the 3 months after the PEx was <90% of the best FEV 1 (in liters) in the 6 months before the PEx. We compared Responders and Non-Responders using multivariable regression models. We randomly chose 13 954 PEx episodes that met inclusion/exclusion criteria. A total of 2 762 (19.8%) patients were classified as Non-Responders. Non-Responders had a shorter median time to the next PEx, 235 (95%CI 218, 252) days, versus >365 days for Responders. Thirty-four percent of Non-Responders at the initial PEx were also Non-Reponders at the next PEx, versus 20% of Responders at the initial PEx. Non-Responders had more PEx episodes over the next 3 years, 4.99 (95%CI 4.84, 5.13), than Responders, 3.46 (95%CI 3.41, 3.51). Poor recovery after a PEx is associated with a shorter time to the next PEx, increased risk of poor recovery at a second PEx, and more frequent subsequent PEx treatments. © 2017 Wiley Periodicals, Inc.

Benchmark test of neutron transport calculations: indium, nickel, gold, europium, and cobalt activation with and without energy moderated fission neutrons by iron simulating the Hiroshima atomic bomb casing.

PubMed

Iwatani, K; Hoshi, M; Shizuma, K; Hiraoka, M; Hayakawa, N; Oka, T; Hasai, H

1994-10-01

A benchmark test of the Monte Carlo neutron and photon transport code system (MCNP) was performed using a bare- and energy-moderated 252Cf fission neutron source which was obtained by transmission through 10-cm-thick iron. An iron plate was used to simulate the effect of the Hiroshima atomic bomb casing. This test includes the activation of indium and nickel for fast neutrons and gold, europium, and cobalt for thermal and epithermal neutrons, which were inserted in the moderators. The latter two activations are also to validate 152Eu and 60Co activity data obtained from the atomic bomb-exposed specimens collected at Hiroshima and Nagasaki, Japan. The neutron moderators used were Lucite and Nylon 6 and the total thickness of each moderator was 60 cm or 65 cm. Measured activity data (reaction yield) of the neutron-irradiated detectors in these moderators decreased to about 1/1,000th or 1/10,000th, which corresponds to about 1,500 m ground distance from the hypocenter in Hiroshima. For all of the indium, nickel, and gold activity data, the measured and calculated values agreed within 25%, and the corresponding values for europium and cobalt were within 40%. From this study, the MCNP code was found to be accurate enough for the bare- and energy-moderated 252Cf neutron activation calculations of these elements using moderators containing hydrogen, carbon, nitrogen, and oxygen.

Neutron detection using a water Cherenkov detector with pure water and a single PMT

NASA Astrophysics Data System (ADS)

Sidelnik, Iván; Asorey, Hernán; Blostein, Juan Jerónimo; Gómez Berisso, Mariano

2017-12-01

We present the performance of a novel neutron detector based on a water Cherenkov detector (WCD) employing pure water and a single photomultiplier tube (PMT). The experiments presented in this work were performed using 241AmBe and 252Cf neutron sources in different neutron moderator and shielding configurations. We show that fast neutrons from the 241AmBe and 241Cf sources, as well as thermal neutrons from a neutron moderator, despite having different spectral characteristics, produce essentially the same pulse histogram shape. This characteristic pulse-height histogram shapes are recorded as a clear signature of neutrons with energies lower than ≃ 11 MeV . This is verified in different experimental conditions. Our estimation of the neutron detection efficiency is at the level of (15±5)%, for fast neutrons. Since water is the material employed as active volume, the results of this study are of interest for the construction of low cost and large active volume neutron detectors for various applications. Of special importance are those related with space weather phenomena monitoring as well as those for the detection of fissile special nuclear material, including uranium or plutonium.

A USB-2 based portable data acquisition system for detector development and nuclear research

NASA Astrophysics Data System (ADS)

Jiang, Hao; Ojaruega, M.; Becchetti, F. D.; Griffin, H. C.; Torres-Isea, R. O.

2011-10-01

A highly portable high-speed CAMAC data acquisition system has been developed using Kmax software (Sparrow, Inc.) for Macintosh laptop and tower computers. It uses a USB-2 interface to the CAMAC crate controller with custom-written software drivers. Kmax permits 2D parameter gating and specific algorithms have been developed to facilitate the rapid evaluation of various multi-element nuclear detectors for energy and time-of-flight measurements. This includes tests using neutrons from 252Cf and a 2.5 MeV neutron generator as well as standard gamma calibration sources such as 60Co and 137Cs. In addition, the system has been used to measure gamma-gamma coincidences over extended time periods using radioactive sources (e.g., Ra-228, Pa-233, Np-237, and Am-243).

Evaluation Of Shielding Efficacy Of A Ferrite Containing Ceramic Material

DOE Office of Scientific and Technical Information (OSTI.GOV)

Verst, C.

2015-10-12

The shielding evaluation of the ferrite based Mitsuishi ceramic material has produced for several radiation sources and possible shielding sizes comparative dose attenuation measurements and simulated projections. High resolution gamma spectroscopy provided uncollided and scattered photon spectra at three energies, confirming theoretical estimates of the ceramic’s mass attenuation coefficient, μ/ρ. High level irradiation experiments were performed using Co-60, Cs-137, and Cf-252 sources to measure penetrating dose rates through steel, lead, concrete, and the provided ceramic slabs. The results were used to validate the radiation transport code MCNP6 which was then used to generate dose rate attenuation curves as a functionmore » of shielding material, thickness, and mass for photons and neutrons ranging in energy from 200 keV to 2 MeV.« less

SHIELDING AND DETECTOR RESPONSE CALCULATIONS PERTAINING TO CATEGORY 1 QUANTITIES OF PLUTONIUM AND HAND-HELD PLASTIC SCINTILLATORS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Couture, A.

2013-06-07

Nuclear facilities sometimes use hand-held plastic scintillator detectors to detect attempts to divert special nuclear material in situations where portal monitors are impractical. MCNP calculations have been performed to determine the neutron and gamma radiation field arising from a Category I quantity of weapons-grade plutonium in various shielding configurations. The shields considered were composed of combinations of lead and high-density polyethylene such that the mass of the plutonium plus shield was 22.7 kilograms. Monte-Carlo techniques were also used to determine the detector response to each of the shielding configurations. The detector response calculations were verified using field measurements of high-,more » medium-, and low- energy gamma-ray sources as well as a Cf-252 neutron source.« less

Developments toward Understanding and Improving the Low Energy Measurement Capabilities of a Fission Time Projection Chamber

NASA Astrophysics Data System (ADS)

Bundgaard, Jeremy J.

Nuclear physicists have been recently called upon for new, high precision fission measurements to improve existing fission models, ultimately enabling engineers to design next generation reactors as well as guarding the nation's stockpile. In response, a resurgence in fission research is aimed at developing detectors to design and build new experiments to meet these needs. The Neutron Induced Fission Fragment Tracking Experiment (NIFFTE) collaboration has developed the fission Time Projection Chamber (fissionTPC) to measure neutron induced fission with unprecedented precision. The fissionTPC is annually deployed to the Los Alamos Neutron Science Center LANSCE where it operates with a neutron beam passing axially through the drift volume, irradiating heavy actinide targets to induce fission. The fissionTPC was developed at the Lawrence Livermore National Laboratory's (LLNL) TPC lab, where it is tested with spontaneous fission (SF) from radioactive sources, typically 252Cf and 244Cm, to characterize detector response, improve performance, and evolve the design. One of the experiments relevant for both nuclear energy and nonproliferation is to measure the neutron induced fission of 239Pu, which exhibits a high alpha activity, generating a large unwanted background for the fission measurements. The ratio of alpha to fission present in our neutron induced fission measurement of 239Pu is on the same order of magnitude as the 244Cm alpha/SF branching ratio. The high alpha rate required the TPC to be triggering on fission signals during beam time and we set out to build a trigger system, which, using 244Cm to produce a similar alpha to fission ratio as 239Pu in the neutron beam, we successfully demonstrated the viability of this approach. The trigger design has been evolved for use in NIFFTE's current measurements at LANSCE. In addition to several hardware and software contributions in the development and operation of the fissionTPC, a central purpose of this thesis was also to develop analyses to demonstrate the fissionTPC's performance abilities/limitations in measuring the alpha/SF branching ratio of 252Cf and 244Cm. Our method results in benchmarking the fissionTPC's ability to produce a competitive alpha/SF ratio for 252Cf with sub-percent precision.

ALGORITHM BASED ON ARTIFICIAL BEE COLONY FOR UNFOLDING OF NEUTRON SPECTRA OBTAINED WITH BONNER SPHERES.

PubMed

Silva, Everton R; Freitas, Bruno M; Santos, Denison S; Maurício, Cláudia L P

2018-04-13

Occupational neutron fields usually have energies from the thermal range to some MeV and the characterization of the spectra is essential for estimation of the radioprotection quantities. Thus, the spectrum must be unfolded based on a limited number of measurements. This study implemented an algorithm based on the bee colonies behavior, named Artificial Bee Colony (ABC), where the intelligent behavior of the bees in search of food is reproduced to perform the unfolding of neutron spectra. The experimental measurements used Bonner spheres and 6LiI (Eu) detector, with irradiations using a thermal neutron flux and three reference fields: 241Am-Be, 252Cf and 252Cf (D2O). The ABC obtained good estimation of the expected spectrum even without previous information and its results were closer to expected spectra than those obtained by the SPUNIT algorithm.

A new measurement of the 6Li(n, α)t cross section at MeV energies using a 252Cf fission chamber and 6Li scintillators

NASA Astrophysics Data System (ADS)

Kirsch, Leo E.; Devlin, M.; Mosby, S. M.; Gomez, J. A.

2017-12-01

A new measurement is presented of the 6Li(n, α)t cross section from 245 keV to 10 MeV using a 252Cf fission chamber with 6LiI(Eu) and Cs2LiYCl6:Ce (CLYC) scintillators which act as both target and detector. Neutron energies are determined from the time of flight (TOF) method using the signals from spontaneous fission and reaction product recoil. Simulations of neutron downscatter in the crystals and fission chamber bring 6Li(n, α)t cross section values measured with the 6LiI(Eu) into agreement with previous experiments and evaluations, except for two resonances at 4.2 and 6.5 MeV introduced by ENDF/B-VII.1. Suspected neutron transport modeling issues cause the cross section values obtained with CLYC to be discrepant above 2 MeV.

Neutron-neutron angular correlations in spontaneous fission of 252Cf and 240Pu

NASA Astrophysics Data System (ADS)

Verbeke, J. M.; Nakae, L. F.; Vogt, R.

2018-04-01

Background: Angular anisotropy has been observed between prompt neutrons emitted during the fission process. Such an anisotropy arises because the emitted neutrons are boosted along the direction of the parent fragment. Purpose: To measure the neutron-neutron angular correlations from the spontaneous fission of 252Cf and 240Pu oxide samples using a liquid scintillator array capable of pulse-shape discrimination. To compare these correlations to simulations combining the Monte Carlo radiation transport code MCNPX with the fission event generator FREYA. Method: Two different analysis methods were used to study the neutron-neutron correlations with varying energy thresholds. The first is based on setting a light output threshold while the second imposes a time-of-flight cutoff. The second method has the advantage of being truly detector independent. Results: The neutron-neutron correlation modeled by FREYA depends strongly on the sharing of the excitation energy between the two fragments. The measured asymmetry enabled us to adjust the FREYA parameter x in 240Pu, which controls the energy partition between the fragments and is so far inaccessible in other measurements. The 240Pu data in this analysis was the first available to quantify the energy partition for this isotope. The agreement between data and simulation is overall very good for 252Cf(sf ) and 240Pu(sf ) . Conclusions: The asymmetry in the measured neutron-neutron angular distributions can be predicted by FREYA. The shape of the correlation function depends on how the excitation energy is partitioned between the two fission fragments. Experimental data suggest that the lighter fragment is disproportionately excited.

Quantitative NDA of isotopic neutron sources.

PubMed

Lakosi, L; Nguyen, C T; Bagi, J

2005-01-01

A non-destructive method for assaying transuranic neutron sources was developed, using a combination of gamma-spectrometry and neutron correlation technique. Source strength or actinide content of a number of PuBe, AmBe, AmLi, (244)Cm, and (252)Cf sources was assessed, both as a safety issue and with respect to combating illicit trafficking. A passive neutron coincidence collar was designed with (3)He counters embedded in a polyethylene moderator (lined with Cd) surrounding the sources to be measured. The electronics consist of independent channels of pulse amplifiers and discriminators as well as a shift register for coincidence counting. The neutron output of the sources was determined by gross neutron counting, and the actinide content was found out by adopting specific spontaneous fission and (alpha,n) reaction yields of individual isotopes from the literature. Identification of an unknown source type and constituents can be made by gamma-spectrometry. The coincidences are due to spontaneous fission in the case of Cm and Cf sources, while they are mostly due to neutron-induced fission of the Pu isotopes (i.e. self-multiplication) and the (9)Be(n,2n)(8)Be reaction in Be-containing sources. Recording coincidence rate offers a potential for calibration, exploiting a correlation between the Pu amount and the coincidence-to-total ratio. The method and the equipment were tested in an in-field demonstration exercise, with participation of national public authorities and foreign observers. Seizure of the illicit transport of a PuBe source was simulated in the exercise, and the Pu content of the source was determined. It is expected that the method could be used for identification and assay of illicit, found, or not documented neutron sources.

Study of the 249-251Cf + 48Ca reactions: recent results and outlook

NASA Astrophysics Data System (ADS)

Voinov, A. A.; Oganessian, Yu Ts; Abdullin, F. Sh; Brewer, N. T.; Dmitriev, S. N.; Grzywacz, R. K.; Hamilton, J. H.; Itkis, M. G.; Miernik, K.; Polyakov, A. N.; Roberto, J. B.; Rykaczewski, K. P.; Sabelnikov, A. V.; Sagaidak, R. N.; Shirokovsky, I. V.; Shumeiko, M. V.; Stoyer, M. A.; Subbotin, V. G.; Sukhov, A. M.; Tsyganov, Yu S.; Utyonkov, V. K.; Vostokin, G. K.

2018-02-01

Experiment aiming at the synthesis of heavy isotopes of Z=118 (Og) using beam of 48Ca and a target of 249-251Cf was undertaken in October 2015 - April 2016 employing the Dubna Gas-Filled Recoil Separator (FLNR JINR). The target of mixed isotopes of 249-251Cf (50.7% of 249Cf, 12.9% of 250Cf, and 36.4% of 251Cf) was irradiated by 48Ca ions at two beam energies of 252 and 258 MeV with the corresponding accumulated beam doses of 1.6×1019 and 1.1×1019. A single event observed at lower beam energy was assigned to the isotope 294Og, the product of the reaction 249Cf(48Ca, 3n); its decay pattern and the observed radioactive properties of the nuclides in the decay chain reproduce in full those observed for 294Og in our earlier experiments of 2002-2005 and 2012. At higher beam energy we observed no decay chains that could be attributed to the isotopes of Og. The possibility of renewal of this experiment in the future is discussed.

Benchmark test of transport calculations of gold and nickel activation with implications for neutron kerma at Hiroshima.

PubMed

Hoshi, M; Hiraoka, M; Hayakawa, N; Sawada, S; Munaka, M; Kuramoto, A; Oka, T; Iwatani, K; Shizuma, K; Hasai, H

1992-11-01

A benchmark test of the Monte Carlo neutron and photon transport code system (MCNP) was performed using a 252Cf fission neutron source to validate the use of the code for the energy spectrum analyses of Hiroshima atomic bomb neutrons. Nuclear data libraries used in the Monte Carlo neutron and photon transport code calculation were ENDF/B-III, ENDF/B-IV, LASL-SUB, and ENDL-73. The neutron moderators used were granite (the main component of which is SiO2, with a small fraction of hydrogen), Newlight [polyethylene with 3.7% boron (natural)], ammonium chloride (NH4Cl), and water (H2O). Each moderator was 65 cm thick. The neutron detectors were gold and nickel foils, which were used to detect thermal and epithermal neutrons (4.9 eV) and fast neutrons (> 0.5 MeV), respectively. Measured activity data from neutron-irradiated gold and nickel foils in these moderators decreased to about 1/1,000th or 1/10,000th, which correspond to about 1,500 m ground distance from the hypocenter in Hiroshima. For both gold and nickel detectors, the measured activities and the calculated values agreed within 10%. The slopes of the depth-yield relations in each moderator, except granite, were similar for neutrons detected by the gold and nickel foils. From the results of these studies, the Monte Carlo neutron and photon transport code was verified to be accurate enough for use with the elements hydrogen, carbon, nitrogen, oxygen, silicon, chlorine, and cadmium, and for the incident 252Cf fission spectrum neutrons.

Verification of threshold activation detection (TAD) technique in prompt fission neutron detection using scintillators containing 19F

NASA Astrophysics Data System (ADS)

Sibczynski, P.; Kownacki, J.; Moszyński, M.; Iwanowska-Hanke, J.; Syntfeld-Każuch, A.; Gójska, A.; Gierlik, M.; Kaźmierczak, Ł.; Jakubowska, E.; Kędzierski, G.; Kujawiński, Ł.; Wojnarowicz, J.; Carrel, F.; Ledieu, M.; Lainé, F.

2015-09-01

In the present study ⌀ 5''× 3'' and ⌀ 2''× 2'' EJ-313 liquid fluorocarbon as well as ⌀ 2'' × 3'' BaF2 scintillators were exposed to neutrons from a 252Cf neutron source and a Sodern Genie 16GT deuterium-tritium (D+T) neutron generator. The scintillators responses to β- particles with maximum endpoint energy of 10.4 MeV from the n+19F reactions were studied. Response of a ⌀ 5'' × 3'' BC-408 plastic scintillator was also studied as a reference. The β- particles are the products of interaction of fast neutrons with 19F which is a component of the EJ-313 and BaF2 scintillators. The method of fast neutron detection via fluorine activation is already known as Threshold Activation Detection (TAD) and was proposed for photofission prompt neutron detection from fissionable and Special Nuclear Materials (SNM) in the field of Homeland Security and Border Monitoring. Measurements of the number of counts between 6.0 and 10.5 MeV with a 252Cf source showed that the relative neutron detection efficiency ratio, defined as epsilonBaF2 / epsilonEJ-313-5'', is 32.0% ± 2.3% and 44.6% ± 3.4% for front-on and side-on orientation of the BaF2, respectively. Moreover, the ⌀ 5'' EJ-313 and side-on oriented BaF2 were also exposed to neutrons from the D+T neutron generator, and the relative efficiency epsilonBaF2 / epsilonEJ-313-5'' was estimated to be 39.3%. Measurements of prompt photofission neutrons with the BaF2 detector by means of data acquisition after irradiation (out-of-beam) of nuclear material and between the beam pulses (beam-off) techniques were also conducted on the 9 MeV LINAC of the SAPHIR facility.

Newborn bloodspot screening for cystic fibrosis: What do antenatal and postnatal women know about cystic fibrosis?

PubMed

Fitzgerald, C; Linnane, B; Heery, E; Conneally, N; George, S; Fitzpatrick, P

2016-07-01

The Republic of Ireland has one of the highest reported incidences of cystic fibrosis (CF) in the world (1/1353) with an estimated carrier rate of 1/20. No cure exists, however there have been significant advances in available treatments. Newborn bloodspot screening (NBS) for CF was added to the NBS programme in Ireland in July 2011. Little is known about antenatal or postnatal women's knowledge about CF. This was a cross-sectional study of 662 antenatal (≥36weeks gestation) and 480 postnatal women (post NBS). Women were asked to self-complete a questionnaire including 14 CF knowledge questions. Among the respondents significantly more postnatal than antenatal women were aware that CF is included on the NBS (81.8% vs 63.5%; p<0.001). 92.7% believe that there are health consequences to being a carrier and 33.6% believe there is a cure for CF. In the multivariate analysis, lower educational status (OR 2.13; 95% CI 1.31, 3.46) being an antenatal mother (OR 1.51; 95% CI 1.04, 2.18), having no family history of CF (OR 5.82; 95% CI 1.62, 20.90) were associated with poor CF knowledge, while increasing age was found to be protective against poor CF knowledge (OR 0.96; 95% CI 0.92, 0.99). Results from this study provide a useful insight into women's preexisting knowledge about CF, which could be used to inform initial discussions with parents about their child's diagnosis. Copyright © 2015 European Cystic Fibrosis Society. Published by Elsevier B.V. All rights reserved.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Joshi, Jay Prakash

The objectives of this project are to calibrate the Advanced Experimental Fuel Counter (AEFC), benchmark MCNP simulations using experimental results, investigate the effects of change in fuel assembly geometry, and finally to show the boost in doubles count rates with 252Cf active soruces due to the time correlated induced fission (TCIF) effect.

A new measurement of the 6Li(n,α)t cross section at MeV energies using a 252Cf fission chamber and 6Li scintillators

DOE PAGES

Kirsch, Leo Edward; Devlin, Matthew James; Mosby, Shea Morgan; ...

2017-09-01

We present a new measurement of the 6Li(n,α)t cross section from 245 keV to 10 MeV using a 252Cf fission chamber with 6LiI(Eu) and Cs 2LiYCl 6:Ce (CLYC) scintillators which act as both target and detector. Neutron energies are determined from the time of flight (TOF) method using the signals from spontaneous fission and reaction product recoil. Simulations of neutron downscatter in the crystals and fission chamber bring 6Li(n,α)t cross section values measured with the 6LiI(Eu) into agreement with previous experiments and evaluations, except for two resonances at 4.2 and 6.5 MeV introduced by ENDF/B-VII.1. Suspected neutron transport modeling issuesmore » cause the cross section values obtained with CLYC to be discrepant above 2 MeV.« less

Application of 252Cf plasma desorption mass spectrometry in dental research

NASA Astrophysics Data System (ADS)

Fritsch, Hans-Walter; Schmidt, Lothar; Köhl, Peter; Jungclas, Hartmut; Duschner, Heins

1993-07-01

Topically applied fluorides introduced in dental hygiene products elevate the concentration levels of fluoride in oral fluids and thus also affect chemical reactions of enamel de- and remineralisation. The chemical reactions on the surface of tooth enamel still are a subject of controversy. Here 252Cf-plasma desorption mass spectrometry and argon ion etching are used to analyse the molecular structure of the upper layes of enamel. The mass spectrum of untreated enamel is characterised by a series of cluster ions containing phosphate. It is evident that under certain conditions the molecular structure of the surface enamel is completely transformed by treatment with fluorides. The result of the degradation and precipitation processes is reflected by a total replacement of the phosphate by fluoride in the measured cluster ion distribution. Stepwise etching of the upper layers by Ar+ ions reveals the transition from a nearly pure CaF2 structure to the unchanged composition of the enamel mineral.

A new measurement of the 6Li(n,α)t cross section at MeV energies using a 252Cf fission chamber and 6Li scintillators

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kirsch, Leo Edward; Devlin, Matthew James; Mosby, Shea Morgan

We present a new measurement of the 6Li(n,α)t cross section from 245 keV to 10 MeV using a 252Cf fission chamber with 6LiI(Eu) and Cs 2LiYCl 6:Ce (CLYC) scintillators which act as both target and detector. Neutron energies are determined from the time of flight (TOF) method using the signals from spontaneous fission and reaction product recoil. Simulations of neutron downscatter in the crystals and fission chamber bring 6Li(n,α)t cross section values measured with the 6LiI(Eu) into agreement with previous experiments and evaluations, except for two resonances at 4.2 and 6.5 MeV introduced by ENDF/B-VII.1. Suspected neutron transport modeling issuesmore » cause the cross section values obtained with CLYC to be discrepant above 2 MeV.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rogers, D.M.; Coggins, T.L.; Marsh, J.

Numerous efforts are funded by US agencies (DOE, DoD, DHS) for development of novel radiation sensing and measurement systems. An effort has been undertaken to develop a flexible shielding system compatible with a variety of sources (beta, X-ray, gamma, and neutron) that can be highly characterized using conventional radiation detection and measurement systems. Sources available for use in this system include americium-beryllium (AmBe), plutonium-beryllium (PuBe), strontium-90 (Sr-90), californium-252 (Cf-252), krypton-85 (Kr-85), americium-241 (Am-241), and depleted uranium (DU). Shielding can be varied by utilization of materials that include lexan, water, oil, lead, and polyethylene. Arrangements and geometries of source(s) and shieldingmore » can produce symmetrical or asymmetrical radiation fields. The system has been developed to facilitate accurately repeatable configurations. Measurement positions are similarly capable of being accurately re-created. Stand-off measurement positions can be accurately re-established using differential global positioning system (GPS) navigation. Instruments used to characterize individual measurement locations include a variety of sodium iodide (NaI(Tl)) (3 x 3 inch, 4 x 4 x 16 inch, Fidler) and lithium iodide (LiI(Eu)) detectors (for use with multichannel analyzer software) and detectors for use with traditional hand held survey meters such as boron trifluoride (BF{sub 3}), helium-3 ({sup 3}He), and Geiger-Mueller (GM) tubes. Also available are Global Dosimetry thermoluminescent dosimeters (TLDs), CR39 neutron chips, and film badges. Data will be presented comparing measurement techniques with shielding/source configurations. The system is demonstrated to provide a highly functional process for comparison/characterization of various detector types relative to controllable radiation types and levels. Particular attention has been paid to use of neutron sources and measurements. (authors)« less

An airport cargo inspection system based on X-ray and thermal neutron analysis (TNA).

PubMed

Ipe, Nisy E; Akery, A; Ryge, P; Brown, D; Liu, F; Thieu, J; James, B

2005-01-01

A cargo inspection system incorporating a high-resolution X-ray imaging system with a material-specific detection system based on Ancore Corporation's patented thermal neutron analysis (TNA) technology can detect bulk quantities of explosives and drugs concealed in trucks or cargo containers. The TNA process utilises a 252Cf neutron source surrounded by a moderator. The neutron interactions with the inspected object result in strong and unique gamma-ray signals from nitrogen, which is a key ingredient in modern high explosives, and from chlorinated drugs. The TNA computer analyses the gamma-ray signals and automatically determines the presence of explosives or drugs. The radiation source terms and shielding design of the facility are described. For the X-ray generator, the primary beam, leakage radiation, and scattered primary and leakage radiation were considered. For the TNA, the primary neutrons and tunnel scattered neutrons as well as the neutron-capture gamma rays were considered.

A Sensitive, Selective, and Portable Detector for Contraband: The Compact Integrated Narcotics Detection Instrument

DOE Office of Scientific and Technical Information (OSTI.GOV)

T. O. Tuemer; L. Doan; C. W. Su

2000-06-04

This paper describes the design and operation of a Compact Integrated Narcotics Detection Instrument (CINDI), which utilizes neutrons emitted from {sup 252}Cf. Neutrons emitted from the front face of CINDI penetrate dense compartment barrier materials with little change in energy but are backscattered by hydrogen-rich materials such as drugs. CINDI has led to a new technology that shows promise for identifying the concealed contraband. Carriers such as vehicles, marine vessels, airplanes, containers, cargo, and luggage will be scanned using both neutron and gamma-ray sources. The signal from both the neutron and gamma-ray backscattering and/or transmission can be used simultaneously tomore » detect and possibly identify the contrabands it has been trained for.« less

Calibration of LiBaF3: Ce Scintillator for Fission Spectrum Neutrons

DOE Office of Scientific and Technical Information (OSTI.GOV)

Reeder, Paul L.; Bowyer, Sonya M.

2002-05-21

The scintillator LiBaF3 doped with small amounts of Ce+3 has the ability to distinguish heavy charged particles (p, d, t, or a) from beta and/or gamma radiation based on the presence or absence of ns components in the scintillation light output. Because the neutron capture reaction on 6Li produces recoil alphas and tritons, this scintillator also discriminates between neutron induced events and beta or gamma interactions. An experimental technique using a time-tagged 252Cf source has been used to measure the efficiency of this scintillator for neutron capture, the calibration of neutron capture pulse height, and the pulse height resolution -more » all as a function of incident neutron energy.« less

Fast neutron flux analyzer with real-time digital pulse shape discrimination

NASA Astrophysics Data System (ADS)

Ivanova, A. A.; Zubarev, P. V.; Ivanenko, S. V.; Khilchenko, A. D.; Kotelnikov, A. I.; Polosatkin, S. V.; Puryga, E. A.; Shvyrev, V. G.; Sulyaev, Yu. S.

2016-08-01

Investigation of subthermonuclear plasma confinement and heating in magnetic fusion devices such as GOL-3 and GDT at the Budker Institute (Novosibirsk, Russia) requires sophisticated equipment for neutron-, gamma- diagnostics and upgrading data acquisition systems with online data processing. Measurement of fast neutron flux with stilbene scintillation detectors raised the problem of discrimination of the neutrons (n) from background cosmic particles (muons) and neutron-induced gamma rays (γ). This paper describes a fast neutron flux analyzer with real-time digital pulse-shape discrimination (DPSD) algorithm FPGA-implemented for the GOL-3 and GDT devices. This analyzer was tested and calibrated with the help of 137Cs and 252Cf radiation sources. The Figures of Merit (FOM) calculated for different energy cuts are presented.

E2/M1 mixing ratios in transitions from the gamma vibrational bands to the ground state rotational bands of 102, 104, 106, 108Mo, 108, 110, 112Ru, and 112, 114, 116Pd

NASA Astrophysics Data System (ADS)

Eldridge, J. M.; Fenker, B.; Hamilton, J. H.; Goodin, C.; Zachary, C. J.; Wang, E.; Ramayya, A. V.; Daniel, A. V.; Ter-Akopian, G. M.; Oganessian, Yu. Ts.; Luo, Y. X.; Rasmussen, J. O.; Zhu, S. J.

2018-02-01

E2/ M1 mixing ratios have been measured for transitions from states in the γ vibrational bands ( I+_{γ}) to states in the ground state bands (I+ or [I-1]+) of the neutron rich, even-even, deformed isotopes, 102, 104, 106, 108Mo, 108, 110, 112Ru, and 112, 114, 116Pd, including from states as high as 9+_{γ}. These measurements were done using the GAMMASPHERE detector array, which, at the time of the experiment, had 101 working HPGe detectors, arranged at 64 different angles. A 62 μCi source of 252Cf was placed inside GAMMASPHERE yielding 5.7× 10^{11} γ-γ-γ and higher coincidence events. The angular correlations between the transitions from the γ-bands to the ground bands, and the pure E2 transitions within the ground band were then measured. These angular correlations yielded the mixing ratios, demonstrating that these transitions are pure or nearly pure E2, in agreement with theory. In order to correct for possible attenuation due to the lifetime of the intermediate state in these correlations, the g-factors of the intermediate states needed to be known. Therefore, the g-factors of the 2+ states in the ground state band have been measured.

Reliability of Monte Carlo simulations in modeling neutron yields from a shielded fission source

NASA Astrophysics Data System (ADS)

McArthur, Matthew S.; Rees, Lawrence B.; Czirr, J. Bart

2016-08-01

Using the combination of a neutron-sensitive 6Li glass scintillator detector with a neutron-insensitive 7Li glass scintillator detector, we are able to make an accurate measurement of the capture rate of fission neutrons on 6Li. We used this detector with a 252Cf neutron source to measure the effects of both non-borated polyethylene and 5% borated polyethylene shielding on detection rates over a range of shielding thicknesses. Both of these measurements were compared with MCNP calculations to determine how well the calculations reproduced the measurements. When the source is highly shielded, the number of interactions experienced by each neutron prior to arriving at the detector is large, so it is important to compare Monte Carlo modeling with actual experimental measurements. MCNP reproduces the data fairly well, but it does generally underestimate detector efficiency both with and without polyethylene shielding. For non-borated polyethylene it underestimates the measured value by an average of 8%. This increases to an average of 11% for borated polyethylene.

Assessment of neutron dosemeters around standard sources and nuclear fissile objects.

PubMed

Raimondi, N; Tournier, B; Groetz, J E; Piot, J; Riebler, E; Crovisier, P; Chambaudet, A; Cabanné, N

2002-01-01

In order to evaluate the neutron doses around nuclear fissile objects, a comparative study has been made on several neutron dosemeters: bubble dosemeters, etched-track detectors (CR-39) and 3He-filled proportional counters used as dose-rate meters. The measurements were made on the ambient and the personal dose equivalents H*(10) and Hp(10). Results showed that several bubble dosemeters should have been used due to a low reproducibility in the measurements. A strong correlation with the neutron energy was also found, with about a 30% underestimation of Hp(10) for neutrons from the PuBe source, and about a 9% overestimation for neutrons from the 252Cf source. Measurements of the nuclear fissile objects were made using the CR-39 and the dose-rate meters. The CR-39 led to an underestimation of 30% with respect to the neutron dose-rate meter measurements. In addition, the MCNP calculation code was used in the different configurations.

40 CFR 61.252 - Standard.

Code of Federal Regulations, 2011 CFR

2011-07-01

... EMISSION STANDARDS FOR HAZARDOUS AIR POLLUTANTS National Emission Standards for Radon Emissions From Operating Mill Tailings § 61.252 Standard. (a) Radon-222 emissions to the ambient air from an existing uranium mill tailings pile shall not exceed 20 pCi/(m2-sec) (1.9 pCi/(ft2-sec)) of radon-222. (b) After...

Early introduction of complementary foods and childhood overweight in breastfed and formula-fed infants in the Netherlands: the PIAMA birth cohort study.

PubMed

Pluymen, Linda P M; Wijga, Alet H; Gehring, Ulrike; Koppelman, Gerard H; Smit, Henriëtte A; van Rossem, L

2018-02-22

To investigate whether early introduction of complementary foods (CF) is associated with an increased risk of overweight during childhood, and whether this association differs between formula-fed and breastfed infants. We included 2611 participants that were born at term from a Dutch population-based birth cohort (n = 3963) designed to investigate the development of asthma and allergies. Parents kept records of their infant's age when CF were first introduced. Weight and height were parent reported yearly from age 1 to 8 years, and at ages 11, 14 and 17 years. We used multivariate generalized estimating equations analysis to investigate the association between timing of CF introduction (before 4 months vs at or after 4 months of age) and overweight at ages 1-17 years. Children with CF introduction before 4 months had higher odds of being overweight during childhood than children with CF introduction at or after 4 months (OR 1.32, 95% CI 1.19, 1.47). This association was observed in formula-fed infants (OR 1.51, 95% CI 1.17, 1.94) and breastfed infants (OR 1.32, 95% CI 1.19, 1.47). The duration of breastfeeding modified the association between CF introduction and overweight: children breastfed for shorter than 4 months, but not children breastfed for 4 months or longer with CF introduction before 4 months had higher odds of being overweight (OR 1.37, 95% CI 1.19, 1.57 and 1.07, 95% CI 0.87, 1.32, respectively), compared to those with CF introduction at or after 4 months. In children born at term, formula-fed infants and infants who were breastfed for shorter than 4 months, but not infants who were breastfed for 4 months or longer, had a higher risk of being overweight during childhood when being introduced to CF before 4 months of age.

Preoperative Right-Sided Cardiac Congestion Is Associated with Gastrointestinal Bleeding in Patients with Continuous-Flow Left Ventricular Assist Devices.

PubMed

Tomizawa, Yutaka; Tanaka, Akiko; Kitahara, Hiroto; Sakuraba, Atsushi; Uriel, Nir; Jeevanandam, Valluvan; Ota, Takeyoshi

2018-06-01

Large scale data on preoperative risk stratification for gastrointestinal bleeding (GIB) following continuous-flow left ventricular assist device (CF-LVAD) implantation are scarce. To identify independent predictors for GIB following CF-LVAD implantation. We conducted a retrospective cohort study of consecutive 243 patients who underwent CF-LVAD implantation (HeartMateII) from January 2009 to March 2015 at the University of Chicago Medical Center. GIB was defined as the presence of overt bleeding or occult GIB with ≥ 2 g/dl drop in hemoglobin (Hgb) from recorded baseline values and hemoccult-positive stool. The preoperative and postoperative data were reviewed. Within a median follow-up duration of 408 (IQR 113-954) days, 83 (34%) patients developed GIB after a median of 149 (IQR 27-615) days after implantation of CF-LVAD. There were no significant differences between the groups of GIB and non-GIB with respect to preoperative demographics and comorbidity except for ethnicity. The source of bleeding was identified in 39 (47%) patients and arteriovenous malformation or submucosal streaming vessel was the most frequent cause of bleeding (18/39, 46%). Multivariate-adjusted analysis demonstrated preoperative central venous pressure (CVP) ≥ 18 mmHg (HR 3.56; 95% CI 1.16-10.9; p = 0.026), mean pulmonary artery pressure (mPA) ≥ 36 mmHg (HR 4.14; 95% CI 1.35-12.7; p = 0.013), and the presence of moderate/severe tricuspid valve disease (HR 1.01; 95% CI 1.01-3.86; p = 0.046) were associated with the risk of GIB. In this study, preoperative right-sided cardiac congestion (i.e., increased CVP, mPA and the presence of moderate/severe tricuspid valve disease) was associated with GIB in patients with CF-LVAD.

Application of real-time PCR of sex-independent insertion-deletion polymorphisms to determine fetal sex using cell-free fetal DNA from maternal plasma.

PubMed

Ho, Sherry Sze Yee; Barrett, Angela; Thadani, Henna; Asibal, Cecille Laureano; Koay, Evelyn Siew-Chuan; Choolani, Mahesh

2015-07-01

Prenatal diagnosis of sex-linked disorders requires invasive procedures, carrying a risk of miscarriage of up to 1%. Cell-free fetal DNA (cffDNA) present in cell-free DNA (cfDNA) from maternal plasma offers a non-invasive source of fetal genetic material for analysis. Detection of Y-chromosome sequences in cfDNA indicates presence of a male fetus; in the absence of a Y-chromosome signal a female fetus is inferred. We aimed to validate the clinical utility of insertion-deletion polymorphisms (INDELs) to confirm presence of a female fetus using cffDNA. Quantitative real-time PCR (qPCR) for the Y-chromosome-specific sequence, SRY, was performed on cfDNA from 82 samples at 6-39 gestational weeks. In samples without detectable SRY, qPCRs for eight INDELs were performed on maternal genomic DNA and cfDNA. Detection of paternally inherited fetal alleles in cfDNA negative for SRY confirmed a female fetus. Fetal sex was correctly determined in 77/82 (93.9%) cfDNA samples. SRY was detected in all 39 samples from male-bearing pregnancies, and none of the 43 female-bearing pregnancies (sensitivity and specificity of SRY qPCR is therefore 100%; 95% CI 91%-100%). Paternally inherited fetal alleles were detected in 38/43 samples with no SRY signal, confirming the presence of a female fetus (INDEL assay sensitivity is therefore 88.4%; 95% CI 74.1%-95.6%). Since paternally inherited fetal INDELs were not used in women bearing male fetuses, the specificity of INDELs cannot be calculated. Five cfDNA samples were negative for both SRY and INDELS. We have validated a non-invasive prenatal test to confirm fetal sex as early as 6 gestational weeks using cffDNA from maternal plasma.

Correlated fission data measurements with DANCE and NEUANCE

NASA Astrophysics Data System (ADS)

Jandel, M.; Baramsai, B.; Bredeweg, T. A.; Couture, A.; Favalli, A.; Hayes, A. C.; Ianakiev, K. D.; Iliev, M. L.; Kawano, T.; Mosby, S.; Rusev, G.; Stetcu, I.; Talou, P.; Ullmann, J. L.; Vieira, D. J.; Walker, C. L.; Wilhelmy, J. B.

2018-02-01

To enhance the capabilities of the DANCE array, a new detector array NEUANCE was developed to enable simultaneous measurements of prompt fission neutrons and γ rays. NEUANCE was designed and constructed using 21 stilbene organic scintillator crystals. It was installed in the central cavity of the DANCE array. Signals from the 160 BaF2 detectors of DANCE and the 21 detectors of NEUANCE were merged into a newly designed high-density high-throughput data acquisition system. The excellent pulse shape discrimination properties of stilbene enabled detection of neutrons with energy thresholds as low as 30-40 keVee. A fission reaction tagging method was developed using a NEUANCE γ-ray or neutron signal. The probability of detecting a neutron from the spontaneous fission of 252Cf using NEUANCE is ∼47%. New correlated data for prompt fission neutrons and prompt fission γ rays were obtained for 252Cf using this high detection efficiency experimental setup. Average properties of prompt fission neutron emission as a function of prompt fission γ-ray quantities were also obtained, suggesting that neutron and γ-ray emission in fission are correlated.

Real-Time, Fast Neutron Coincidence Assay of Plutonium With a 4-Channel Multiplexed Analyzer and Organic Scintillators

NASA Astrophysics Data System (ADS)

Joyce, Malcolm J.; Gamage, Kelum A. A.; Aspinall, M. D.; Cave, F. D.; Lavietes, A.

2014-06-01

The design, principle of operation and the results of measurements made with a four-channel organic scintillator system are described. The system comprises four detectors and a multiplexed analyzer for the real-time parallel processing of fast neutron events. The function of the real-time, digital multiple-channel pulse-shape discrimination analyzer is described together with the results of laboratory-based measurements with 252Cf, 241Am-Li and plutonium. The analyzer is based on a single-board solution with integrated high-voltage supplies and graphical user interface. It has been developed to meet the requirements of nuclear materials assay of relevance to safeguards and security. Data are presented for the real-time coincidence assay of plutonium in terms of doubles count rate versus mass. This includes an assessment of the limiting mass uncertainty for coincidence assay based on a 100 s measurement period and samples in the range 0-50 g. Measurements of count rate versus order of multiplicity for 252Cf and 241Am-Li and combinations of both are also presented.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jandel, Marian; Baramsai, Baramsai; Bredeweg, Todd Allen

To enhance the capabilities of the DANCE array, a new detector array NEUANCE was developed to enable simultaneous measurements of prompt fission neutrons and γ rays. NEUANCE was designed and constructed using 21 stilbene organic scintillator crystals. It was installed in the central cavity of the DANCE array. Signals from the 160 BaF 2 detectors of DANCE and the 21 detectors of NEUANCE were merged into a newly designed high-density high-throughput data acquisition system. The excellent pulse shape discrimination properties of stilbene enabled detection of neutrons with energy thresholds as low as 30–40 keVee. A fission reaction tagging method wasmore » developed using a NEUANCE γ-ray or neutron signal. The probability of detecting a neutron from the spontaneous fission of 252Cf using NEUANCE is 47%. New correlated data for prompt fission neutrons and prompt fission rays were obtained for 252Cf using this high detection efficiency experimental setup. In conclusion, average properties of prompt fission neutron emission as a function of prompt fission γ-ray quantities were also obtained, suggesting that neutron and γ-ray emission in fission are correlated.« less

Correlations of neutron multiplicity and γ -ray multiplicity with fragment mass and total kinetic energy in spontaneous fission of Cf 252

DOE PAGES

Wang, Taofeng; Li, Guangwu; Zhu, Liping; ...

2016-01-08

The dependence of correlations of neutron multiplicity ν and γ-ray multiplicity M γ in spontaneous fission of 252Cf on fragment mass A* and total kinetic energy (TKE) have been investigated by employing the ratio of M γ/ν and the form of M γ(ν). We show for the first time that M γ and ν have a complex correlation for heavy fragment masses, while there is a positive dependence of Mγ for light fragment masses and for near-symmetric mass splits. The ratio M γ/ν exhibits strong shell effects for neutron magic number N=50 and near doubly magic number shell closure atmore » Z=50 and N=82. The γ-ray multiplicity Mγ has a maximum for TKE=165-170 MeV. Above 170 MeV M γ(TKE) is approximately linear, while it deviates significantly from a linear dependence at lower TKE. The correlation between the average neutron and γ-ray multiplicities can be partly reproduced by model calculations.« less

Detecting special nuclear material using a neutron time projection chamber

NASA Astrophysics Data System (ADS)

Carosi, G.; Bernstein, A.; Bowden, N.; Burke, J.; Carter, D.; Foxe, M.; Heffner, M.; Jovanovic, I.; Mintz, J.; O'Malley, P.

2010-02-01

Time projection chambers are 3-dimensional charged particle cameras based on drifting ionization tracks at a known velocity onto an electronic readout plane. These instruments are capable of detecting fast neutrons which are unique signatures of special nuclear material with low natural background rates. Here we describe a neutron Time Projection Chamber (nTPC) developed at Lawrence Livermore National Laboratory (LLNL) which has demonstrated directional sensitivity to fission neutrons along with high rejection of background gamma-ray and electron events. Using a combination hydrogen/methane drift gas at several atmospheres we've demonstrated the ability to point to a Cf-252 source simulating 6kg of weapons grade plutonium at 10's of meters with one hour integration time. Plans for future field deployable devices will also be outlined. )

Verification of a SEU model for advanced 1-micron CMOS structures using heavy ions

NASA Technical Reports Server (NTRS)

Cable, J. S.; Carter, J. R.; Witteles, A. A.

1986-01-01

Modeling and test results are reported for 1 micron CMOS circuits. Analytical predictions are correlated with experimental data, and sensitivities to process and design variations are discussed. Unique features involved in predicting the SEU performance of these devices are described. The results show that the critical charge for upset exhibits a strong dependence on pulse width for very fast devices, and upset predictions must factor in the pulse shape. Acceptable SEU error rates can be achieved for a 1 micron bulk CMOS process. A thin retrograde well provides complete SEU immunity for N channel hits at normal incidence angle. Source interconnect resistance can be important parameter in determining upset rates, and Cf-252 testing can be a valuable tool for cost-effective SEU testing.

Canister cryogenic system for cooling germanium semiconductor detectors in borehole and marine probes

USGS Publications Warehouse

Boynton, G.R.

1975-01-01

High resolution intrinsic and lithium-drifted germanium gamma-ray detectors operate at about 77-90 K. A cryostat for borehole and marine applications has been designed that makes use of prefrozen propane canisters. Uses of such canisters simplifies cryostat construction, and the rapid exchange of canisters greatly reduces the time required to restore the detector to full holding-time capability and enhances the safety of a field operation where high-intensity 252Cf or other isotopic sources are used. A holding time of 6 h at 86 K was achieved in the laboratory in a simulated borehole probe in which a canister 3.7 cm diameter by 57 cm long was used. Longer holding times can be achieved by larger volume canisters in marine probes. ?? 1975.

[Shape of neutron energy].

PubMed

Nohtomi, Akihiro

2012-01-01

Cone-like acryl converters have been used for transforming the energy-distribution information of incident fast neutrons into the spatial-distribution information of recoil protons. The characteristics of neutron-proton conversion have been studied up to around 10MeV by using an imaging plate (IP). A notable and interesting signal enhancement due to recoil protons generated in an acrylic converter was observed on IP images for irradiation with a 252Cf source. A Monte Carlo calculation was carried out in order to understand the spatial distributions of the signal enhancement by recoil protons; these distributions promisingly involve the energy information of incident neutrons in principle. Consequently, it has been revealed that the neutron energy evaluation is surely possible by analyzing the spatial distributions of signal enhancement that is caused by recoil protons.

Micronucleus induction in Vicia faba roots. Part 2. Biological effects of neutrons below 1 cGy.

PubMed

Marshall, I; Bianchi, M

1983-08-01

A dose-effect relationship has been established for high-energy neutrons (maximum energy 600 MeV) within a dose range of 0.2 to 80 cGy and for low-energy neutrons produced by a 252Cf source (mean energy 2.35 MeV) for doses between 0.2 and 5 cGy. The frequency of micronuclei was found to increase linearly with dose. The relative biological effectiveness (r.b.e) values calculated using 60Co radiation as a reference were, in the high-dose region, 4.7 +/- 0.4 and 11.8 +/- 1.3 for the high- and low-energy neutrons, respectively. At doses below 1 cGy constant values of 25.4 +/- 4.4 and 63.7 +/- 12 were reached for the respective neutron energies.

Analytical validation of BRAF mutation testing from circulating free DNA using the amplification refractory mutation testing system.

PubMed

Aung, Kyaw L; Donald, Emma; Ellison, Gillian; Bujac, Sarah; Fletcher, Lynn; Cantarini, Mireille; Brady, Ged; Orr, Maria; Clack, Glen; Ranson, Malcolm; Dive, Caroline; Hughes, Andrew

2014-05-01

BRAF mutation testing from circulating free DNA (cfDNA) using the amplification refractory mutation testing system (ARMS) holds potential as a surrogate for tumor mutation testing. Robust assay validation is needed to establish the optimal clinical matrix for measurement and cfDNA-specific mutation calling criteria. Plasma- and serum-derived cfDNA samples from 221 advanced melanoma patients were analyzed for BRAF c.1799T>A (p.V600E) mutation using ARMS in two stages in a blinded fashion. cfDNA-specific mutation calling criteria were defined in stage 1 and validated in stage 2. cfDNA concentrations in serum and plasma, and the sensitivities and specificities of BRAF mutation detection in these two clinical matrices were compared. Sensitivity of BRAF c.1799T>A (p.V600E) mutation detection in cfDNA was increased by using mutation calling criteria optimized for cfDNA (these criteria were adjusted from those used for archival tumor biopsies) without compromising specificity. Sensitivity of BRAF mutation detection in serum was 44% (95% CI, 35% to 53%) and in plasma 52% (95% CI, 43% to 61%). Specificity was 96% (95% CI, 90% to 99%) in both matrices. Serum contains significantly higher total cfDNA than plasma, whereas the proportion of tumor-derived mutant DNA was significantly higher in plasma. Using mutation calling criteria optimized for cfDNA improves sensitivity of BRAF c.1799T>A (p.V600E) mutation detection. The proportion of tumor-derived cfDNA in plasma was significantly higher than in serum. Copyright © 2014 American Society for Investigative Pathology and the Association for Molecular Pathology. Published by Elsevier Inc. All rights reserved.

Predictors of influenza vaccination in the Cystic Fibrosis Foundation patient registry, 2006 through 2007.

PubMed

Ortiz, Justin R; Neuzil, Kathleen M; Victor, John C; Aitken, Moira L; Goss, Christopher H

2010-12-01

Influenza vaccination is recommended for all persons with cystic fibrosis (CF). Despite this recommendation, no study has been performed to determine factors associated with receipt of influenza vaccination among persons with CF. We conducted a 2-year cohort study from 2006 through 2007 using the CF Foundation (CFF) Patient Registry to assess predictors of influenza vaccination with logistical regression modeling. In 2006, the cohort consisted of 16,435 persons with vaccination data seen at CFF care centers. Vaccination rates were high for children aged < 5 years (90.5%), children 5 to < 18 years (91.1%), and adults (87.9%). In 2006, decreased odds of vaccination were seen among adults with other or unknown insurance (0.37; 95% CI, 0.15-0.87). Among children 5 to < 18 years and adults, decreased odds of vaccination were seen among Hispanics (children, 0.74; 95% CI, 0.55-0.98; adults, 0.67; 95% CI, 0.46-0.98) and with use of oxygen therapy (children, 0.55; 95% CI, 0.38-0.78; adults, 0.68; 95% CI, 0.55-0.86), whereas four or more clinic visits annually was associated with increased odds of vaccination (children, 2.33; 95% CI, 1.92-2.84; adults, 2.05; 95% CI, 1.71-2.47). Findings associated with decreased vaccine receipt remained significant in sensitivity analyses that assumed missing vaccination data were vaccine positive. Overall influenza vaccination rates are very high in the US CF population. Knowledge of influenza vaccination predictors among persons with CF may aid clinicians in targeting patients at greater risk for influenza infection. These data may have important implications for the evolving pandemic 2009 influenza A(H1N1).

E 2 / M 1 Mixing Ratios in Transitions From the Gamma-Vibrational-Bands to the Ground-State-Rotational-Bands of 102 , 104 , 106 , 108Mo, 108 , 110 , 112Ru, and 112 , 114 , 116Pd

NASA Astrophysics Data System (ADS)

Eldridge, Jonathan M.; Fenker, B.; Goodin, C.; Hamilton, J. H.; Wang, E. H.; Ramayya, A. V.; Daniel, A. V.; Ter-Akopian, G. M.; Luo, Y. X.; Rasmussen, J. O.; Oganesson, Yu. Ts.; Zhu, S. J.

2017-09-01

E 2 / M 1 mixing ratios have been measured for transitions from states in the γ-vibrational-bands (Iγ+) to states in the ground-state-bands (Ig+ or [I- 1 ] g +) of the neutron rich, deformed isotopes, 102 , 104 , 106 , 108Mo, 108 , 110 , 112Ru, and 112 , 114 , 116Pd, including from states as high as 9γ+. These measurements were done using the GAMMASPHERE detector array, which, at the time of the experiment, had 101 working HPGe detectors, arranged at 64 different angles. A 62 μCi source of 252Cf was placed inside GAMMASPHERE yielding 5.7 ×1011 γ - γ - γ and higher coincidence events. The angular correlation between the transitions from the γ-band to the ground band, and the pure E2 transitions within the ground band were then measured. These angular correlations yielded the mixing ratios, demonstrating that these transitions are all pure or nearly pure E2, in agreement with theory. In order to correct for possible attenuation due to the lifetime of the intermediate state in these correlations, the g-factors of the intermediate states needed to be known. Therefore, the g-factors of the 2g+ states in the ground state band have been measured. Supported by the US Department of Energy; Grant No. DE-FG0588ER40407, Contract No. DE-AC03-76SF00098.

Development of a lithium fluoride zinc sulfide based neutron multiplicity counter

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cowles, Christian; Behling, Spencer; Baldez, Phoenix

Here, the feasibility of a full-scale lithium fluoride zinc sulfide (LiF/ZnS) based neutron multiplicity counter has been demonstrated. The counter was constructed of modular neutron detecting stacks that each contain five sheets of LiF/ZnS interleaved between six sheets of wavelength shifting plastic with a photomultiplier tube on each end. Twelve such detector stacks were placed around a sample chamber in a square arrangement with lithiated high-density polyethylene blocks in the corners to reflect high-energy neutrons and capture low-energy neutrons. The final system design was optimized via modeling and small-scale test. Measuring neutrons from a 252Cf source, the counter achieved amore » 36% neutron detection efficiency (ϵϵ) and an View the MathML source11.7μs neutron die-away time (ττ) for a doubles figure-of-merit (ϵ 2/τ) of 109. This is the highest doubles figure-of-merit measured to-date for a 3He-free neutron multiplicity counter.« less

Unfolding the neutron spectrum of a NE213 scintillator using artificial neural networks.

PubMed

Sharghi Ido, A; Bonyadi, M R; Etaati, G R; Shahriari, M

2009-10-01

Artificial neural networks technology has been applied to unfold the neutron spectra from the pulse height distribution measured with NE213 liquid scintillator. Here, both the single and multi-layer perceptron neural network models have been implemented to unfold the neutron spectrum from an Am-Be neutron source. The activation function and the connectivity of the neurons have been investigated and the results have been analyzed in terms of the network's performance. The simulation results show that the neural network that utilizes the Satlins transfer function has the best performance. In addition, omitting the bias connection of the neurons improve the performance of the network. Also, the SCINFUL code is used for generating the response functions in the training phase of the process. Finally, the results of the neural network simulation have been compared with those of the FORIST unfolding code for both (241)Am-Be and (252)Cf neutron sources. The results of neural network are in good agreement with FORIST code.

Development of a lithium fluoride zinc sulfide based neutron multiplicity counter

DOE PAGES

Cowles, Christian; Behling, Spencer; Baldez, Phoenix; ...

2018-01-12

Here, the feasibility of a full-scale lithium fluoride zinc sulfide (LiF/ZnS) based neutron multiplicity counter has been demonstrated. The counter was constructed of modular neutron detecting stacks that each contain five sheets of LiF/ZnS interleaved between six sheets of wavelength shifting plastic with a photomultiplier tube on each end. Twelve such detector stacks were placed around a sample chamber in a square arrangement with lithiated high-density polyethylene blocks in the corners to reflect high-energy neutrons and capture low-energy neutrons. The final system design was optimized via modeling and small-scale test. Measuring neutrons from a 252Cf source, the counter achieved amore » 36% neutron detection efficiency (ϵϵ) and an View the MathML source11.7μs neutron die-away time (ττ) for a doubles figure-of-merit (ϵ 2/τ) of 109. This is the highest doubles figure-of-merit measured to-date for a 3He-free neutron multiplicity counter.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Andrews, Madison Theresa; Bates, Cameron Russell; Mckigney, Edward Allen

Here, this work presents the organic scintillation simulation capabilities of DRiFT, a post-processing Detector Response Function Toolkit for MCNPR output. DRiFT is used to create realistic scintillation detector response functions to incident neutron and gamma mixed- field radiation. As a post-processing tool, DRiFT leverages the extensively validated radiation transport capabilities of MCNPR ®6, which also provides the ability to simulate complex sources and geometries. DRiFT is designed to be flexible, it allows the user to specify scintillator material, PMT type, applied PMT voltage, and quenching data used in simulations. The toolkit's capabilities, which include the generation of pulse shape discriminationmore » plots and full-energy detector spectra, are demonstrated in a comparison of measured and simulated neutron contributions from 252Cf and PuBe, and photon spectra from 22Na and 228Th sources. DRiFT reproduced energy resolution effects observed in EJ-301 measurements through the inclusion of scintillation yield variances, photon transport noise, and PMT photocathode and multiplication noise.« less

Organic Scintillator Detector Response Simulations with DRiFT

DOE PAGES

Andrews, Madison Theresa; Bates, Cameron Russell; Mckigney, Edward Allen; ...

2016-06-11

Here, this work presents the organic scintillation simulation capabilities of DRiFT, a post-processing Detector Response Function Toolkit for MCNPR output. DRiFT is used to create realistic scintillation detector response functions to incident neutron and gamma mixed- field radiation. As a post-processing tool, DRiFT leverages the extensively validated radiation transport capabilities of MCNPR ®6, which also provides the ability to simulate complex sources and geometries. DRiFT is designed to be flexible, it allows the user to specify scintillator material, PMT type, applied PMT voltage, and quenching data used in simulations. The toolkit's capabilities, which include the generation of pulse shape discriminationmore » plots and full-energy detector spectra, are demonstrated in a comparison of measured and simulated neutron contributions from 252Cf and PuBe, and photon spectra from 22Na and 228Th sources. DRiFT reproduced energy resolution effects observed in EJ-301 measurements through the inclusion of scintillation yield variances, photon transport noise, and PMT photocathode and multiplication noise.« less

Organic scintillator detector response simulations with DRiFT

NASA Astrophysics Data System (ADS)

Andrews, M. T.; Bates, C. R.; McKigney, E. A.; Solomon, C. J.; Sood, A.

2016-09-01

This work presents the organic scintillation simulation capabilities of DRiFT, a post-processing Detector Response Function Toolkit for MCNP® output. DRiFT is used to create realistic scintillation detector response functions to incident neutron and gamma mixed-field radiation. As a post-processing tool, DRiFT leverages the extensively validated radiation transport capabilities of MCNP® 6 , which also provides the ability to simulate complex sources and geometries. DRiFT is designed to be flexible, it allows the user to specify scintillator material, PMT type, applied PMT voltage, and quenching data used in simulations. The toolkit's capabilities, which include the generation of pulse shape discrimination plots and full-energy detector spectra, are demonstrated in a comparison of measured and simulated neutron contributions from 252Cf and PuBe, and photon spectra from 22Na and 228Th sources. DRiFT reproduced energy resolution effects observed in EJ-301 measurements through the inclusion of scintillation yield variances, photon transport noise, and PMT photocathode and multiplication noise.

Experimental study of boron-coated straws with a neutron source

NASA Astrophysics Data System (ADS)

Xie, Zhaoyang; Zhou, Jianrong; Song, Yushou; Lacy, Jeffrey L.; Sun, Liang; Sun, Zhijia; Hu, Bitao; Chen, Yuanbo

2018-04-01

Multiple types of high quality neutron detectors are proposed for the first phase of the China Spallation Neutron Source (CSNS), which will be commissioned in 2018. Considering the shortage of 3He supply, a detector module composed of 49 boron-coated straws (BCS) was developed by Proportional Technologies Inc. (PTI). Each straw has a length of 1000 mm and a diameter of 7.5 mm. Seven straws are tightly packed in a tube, and seven tubes are organized in a row to form a detector module. The charge division method is used for longitudinal positioning. A specific readout system was utilized to output the signal and simultaneously encode each straw. The performance of this detector module was studied using a moderated 252Cf source at the Institute of High Energy Physics (IHEP). The signal amplitude spectrum indicates its n-gamma discrimination capability. Despite the complex readout method, a longitudinal resolution of FWHM=6.1 ± 0.5 mm was obtained. The three-dimensional positioning ability qualifies this BCS detector module as a promising detector for small angle neutron scattering.

TUNABLE IRRADIATION TESTBED

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wootan, David W.; Casella, Andrew M.; Asner, David M.

PNNL has developed and continues to develop innovative methods for characterizing irradiated materials from nuclear reactors and particle accelerators for various clients and collaborators around the world. The continued development of these methods, in addition to the ability to perform unique scientific investigations of the effects of radiation on materials could be greatly enhanced with easy access to irradiation facilities. A Tunable Irradiation Testbed with customized targets (a 30 MeV, 1mA cyclotron or similar coupled to a unique target system) is shown to provide a much more flexible and cost-effective source of irradiating particles than a test reactor or isotopicmore » source. The configuration investigated was a single shielded building with multiple beam lines from a small, flexible, high flux irradiation source. Potential applications investigated were the characterization of radiation damage to materials applicable to advanced reactors, fusion reactor, legacy waste, (via neutron spectra tailored to HTGR, molten salt, LWR, LMR, fusion environments); 252Cf replacement; characterization of radiation damage to materials of interest to High Energy Physics to enable the neutrino program; and research into production of short lived isotopes for potential medical and other applications.« less

Impact of bronchiectasis and trapped air on quality of life and exacerbations in cystic fibrosis.

PubMed

Tepper, Leonie A; Utens, Elisabeth M W J; Caudri, Daan; Bos, Aukje C; Gonzalez-Graniel, Karla; Duivenvoorden, Hugo J; van der Wiel, Els C W; Quittner, Alexandra L; Tiddens, Harm A W M

2013-08-01

Cystic fibrosis (CF) is primarily characterised by bronchiectasis and trapped air on chest computed tomography (CT). The revised Cystic Fibrosis Questionnaire respiratory symptoms scale (CFQ-R RSS) measures health-related quality of life. To validate bronchiectasis, trapped air and CFQ-R RSS as outcome measures, we investigated correlations and predictive values for pulmonary exacerbations. CF patients (aged 6-20 years) underwent CT, CFQ-R RSS and 1-year follow-up. Bronchiectasis and trapped air were scored using the CF-CT scoring system. Correlation coefficients and backward multivariate modelling were used to identify predictors of pulmonary exacerbations. 40 children and 32 adolescents were included. CF-CT bronchiectasis (r = -0.38, p<0.001) and CF-CT trapped air (r = -0.35, p = 0.003) correlated with CFQ-R RSS. Pulmonary exacerbations were associated with: bronchiectasis (rate ratio 1.10, 95% CI 1.02-1.19; p = 0.009), trapped air (rate ratio 1.02, 95% CI 1.00-1.05; p = 0.034) and CFQ-R RSS (rate ratio 0.95, 95% CI 0.91-0.98; p = 0.002). The CFQ-R RSS was an independent predictor of pulmonary exacerbations (rate ratio 0.96, 95% CI 0.94-0.97; p<0.001). Bronchiectasis, trapped air and CFQ-R RSS were associated with pulmonary exacerbations. The CFQ-R RSS was an independent predictor. This study further validated bronchiectasis, trapped air and CFQ-R RSS as outcome measures in CF.

Sweat conductivity and coulometric quantitative test in neonatal cystic fibrosis screening.

PubMed

Domingos, Mouseline Torquato; Magdalena, Neiva Isabel Rodrigues; Cat, Mônica Nunes Lima; Watanabe, Alexandra Mitiru; Rosário Filho, Nelson Augusto

2015-01-01

To compare the results obtained with the sweat test using the conductivity method and coulometric measurement of sweat chloride in newborns (NBs) with suspected cystic fibrosis (CF) in the neonatal screening program. The sweat test was performed simultaneously by both methods in children with and without CF. The cutoff values to confirm CF were >50 mmol/L in the conductivity and >60 mmol/L in the coulometric test. There were 444 infants without CF (185 males, 234 females, and 24 unreported) submitted to the sweat test through conductivity and coulometric measurement simultaneously, obtaining median results of 32 mmol/L and 12 mmol/L, respectively. For 90 infants with CF, the median values of conductivity and coulometric measurement were 108 mmol/L and 97 mmol/L, respectively. The false positive rate for conductivity was 16.7%, and was higher than 50 mmol/L in all patients with CF, which gives this method a sensitivity of 100% (95% CI: 93.8-97.8), specificity of 96.2% (95% CI: 93.8-97.8), positive predictive value of 83.3% (95% CI: 74.4-91.1), negative predictive value of 100% (95% CI: 90.5-109.4), and 9.8% accuracy. The correlation between the methods was r=0.97 (p>0.001). The best suggested cutoff value was 69.0 mmol/L, with a kappa coefficient=0.89. The conductivity test showed excellent correlation with the quantitative coulometric test, high sensitivity and specificity, and can be used in the diagnosis of CF in children detected through newborn screening. Copyright © 2015 Sociedade Brasileira de Pediatria. Published by Elsevier Editora Ltda. All rights reserved.

Heterogeneity in Survival in Adult Patients With Cystic Fibrosis With FEV1 < 30% of Predicted in the United States.

PubMed

Ramos, Kathleen J; Quon, Bradley S; Heltshe, Sonya L; Mayer-Hamblett, Nicole; Lease, Erika D; Aitken, Moira L; Weiss, Noel S; Goss, Christopher H

2017-06-01

Lung transplantation (LTx) is frequently considered for patients with cystic fibrosis (CF) when the FEV 1 reaches < 30%. This study estimated transplant-free survival for patients with CF and an FEV 1  < 30% and identified predictors of death without LTx. We conducted a retrospective cohort study using the CF Foundation Patient Registry from January 1, 2003 to December 31, 2013. Adult patients (≥ 18 years) with FEV 1  < 30% prior to LTx were included. We performed Kaplan-Meier survival estimates censored at LTx. Multivariable Cox proportional hazard regression identified predictors of mortality. There were 3,340 patients with an FEV 1  < 30%. Death without LTx occurred in 1,250 patients (37.4%); 951 patients (28.5%) underwent LTx; 918 patients (27.5%) remained alive without LTx at the end of follow-up; and 221 patients (6.6%) were lost to follow-up. Median transplant-free survival after FEV 1  < 30% was 6.6 years (95% CI, 5.9-7.0). Adjusted predictors of death without LTx included supplemental oxygen use (hazard ratio [HR], 2.1; 95% CI, 1.7-2.6), Burkholderia cepacia infection (HR, 1.8; 95% CI, 1.3-2.6), BMI ≤ 18 (HR, 1.6; 95% CI, 1.3-1.9), female sex (HR, 1.6; 95% CI, 1.2-2.0), CF-related diabetes in patients receiving insulin (HR, 1.4; 95% CI, 1.2-1.8), and ≥ one exacerbation per year (HR, 1.7; 95% CI, 1.3-2.2 vs. 0 exacerbations). Median survival was > 6.5 years for patients with CF and an FEV 1  < 30%, exceeding prior survival estimates. There was substantial heterogeneity in survival, with some patients with CF dying soon after reaching this lung function threshold and others living for many years. For this reason, we conclude that FEV 1  < 30% remains an important marker of disease severity for patients with CF. Patients with a supplemental oxygen requirement or frequent exacerbations should have prompt referral because of their increased risk of death. Copyright © 2017 American College of Chest Physicians. Published by Elsevier Inc. All rights reserved.

FY2017 Report on NISC Measurements and Detector Simulations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Andrews, Madison Theresa; Meierbachtol, Krista Cruse; Jordan, Tyler Alexander

FY17 work focused on automation, both of the measurement analysis and comparison of simulations. The experimental apparatus was relocated and weeks of continuous measurements of the spontaneous fission source 252Cf was performed. Programs were developed to automate the conversion of measurements into ROOT data framework files with a simple terminal input. The complete analysis of the measurement (which includes energy calibration and the identification of correlated counts) can now be completed with a documented process which involves one simple execution line as well. Finally, the hurdles of slow MCNP simulations resulting in low simulation statistics have been overcome with themore » generation of multi-run suites which make use of the highperformance computing resources at LANL. Preliminary comparisons of measurements and simulations have been performed and will be the focus of FY18 work.« less

Feasibility study for wax deposition imaging in oil pipelines by PGNAA technique.

PubMed

Cheng, Can; Jia, Wenbao; Hei, Daqian; Wei, Zhiyong; Wang, Hongtao

2017-10-01

Wax deposition in pipelines is a crucial problem in the oil industry. A method based on the prompt gamma-ray neutron activation analysis technique was applied to reconstruct the image of wax deposition in oil pipelines. The 2.223MeV hydrogen capture gamma rays were used to reconstruct the wax deposition image. To validate the method, both MCNP simulation and experiments were performed for wax deposited with a maximum thickness of 20cm. The performance of the method was simulated using the MCNP code. The experiment was conducted with a 252 Cf neutron source and a LaBr 3 : Ce detector. A good correspondence between the simulations and the experiments was observed. The results obtained indicate that the present approach is efficient for wax deposition imaging in oil pipelines. Copyright © 2017 Elsevier Ltd. All rights reserved.

Neutron and gamma-ray energy reconstruction for characterization of special nuclear material

DOE PAGES

Clarke, Shaun D.; Hamel, Michael C.; Di fulvio, Angela; ...

2017-06-30

Characterization of special nuclear material may be performed using energy spectroscopy of either the neutron or gamma-ray emissions from the sample. Gamma-ray spectroscopy can be performed relatively easily using high-resolution semiconductors such as high-purity germanium. Neutron spectroscopy, by contrast, is a complex inverse problem. Here, results are presented for 252Cf and PuBe energy spectra unfolded using a single EJ309 organic scintillator; excellent agreement is observed with the reference spectra. Neutron energy spectroscopy is also possible using a two-plane detector array, whereby time-offlight kinematics can be used. With this system, energy spectra can also be obtained as a function of position.more » Finally, spatial-dependent energy spectra are presented for neutron and gamma-ray sources that are in excellent agreement with expectations.« less

Detection of fast neutrons from shielded nuclear materials using a semiconductor alpha detector.

PubMed

Pöllänen, R; Siiskonen, T

2014-08-01

The response of a semiconductor alpha detector to fast (>1 MeV) neutrons was investigated by using measurements and simulations. A polyethylene converter was placed in front of the detector to register recoil protons generated by elastic collisions between neutrons and hydrogen nuclei of the converter. The developed prototype equipment was tested with shielded radiation sources. The low background of the detector and insensitivity to high-energy gamma rays above 1 MeV are advantages when the detection of neutron-emitting nuclear materials is of importance. In the case of a (252)Cf neutron spectrum, the intrinsic efficiency of fast neutron detection was determined to be 2.5×10(-4), whereas three-fold greater efficiency was obtained for a (241)AmBe neutron spectrum. Copyright © 2014 Elsevier Ltd. All rights reserved.

Neutron and gamma-ray energy reconstruction for characterization of special nuclear material

DOE Office of Scientific and Technical Information (OSTI.GOV)

Clarke, Shaun D.; Hamel, Michael C.; Di fulvio, Angela

Characterization of special nuclear material may be performed using energy spectroscopy of either the neutron or gamma-ray emissions from the sample. Gamma-ray spectroscopy can be performed relatively easily using high-resolution semiconductors such as high-purity germanium. Neutron spectroscopy, by contrast, is a complex inverse problem. Here, results are presented for 252Cf and PuBe energy spectra unfolded using a single EJ309 organic scintillator; excellent agreement is observed with the reference spectra. Neutron energy spectroscopy is also possible using a two-plane detector array, whereby time-offlight kinematics can be used. With this system, energy spectra can also be obtained as a function of position.more » Finally, spatial-dependent energy spectra are presented for neutron and gamma-ray sources that are in excellent agreement with expectations.« less

ORGANIC SCINTILLATOR FOR REAL-TIME NEUTRON DOSIMETRY.

PubMed

Beyer, Kyle A; Di Fulvio, Angela; Stolarczyk, Liliana; Parol, Wiktor; Mojzeszek, Natalia; Kopéc, Renata; Clarke, Shaun D; Pozzi, Sara A

2017-11-15

We developed a radiation detector based on an organic scintillator for spectrometry and dosimetry of out-of-field secondary neutrons from clinical proton beams. The detector consists of an EJ-299-34 crystalline organic scintillator, coupled by fiber optic cable to a silicon photomultiplier (SiPM). Proof of concept measurements were taken with 137Cs and 252Cf, and corresponding simulations were performed in MCNPX-PoliMi. Despite its small size, the detector is able to discriminate between neutron and gamma-rays via pulse shape discrimination. We simulated the response function of the detector to monoenergetic neutrons in the 100 keV-0 MeV range using MCNPX-PoliMi. The measured unfolded 252Cf neutron spectrum is in good agreement with the theoretical Watt fission spectrum. We determined the ambient dose equivalent by folding the spectrum with the fluence-to-ambient dose conversion coefficient, with a 1.4% deviation from theory. Some preliminary proton beam experiments were preformed at the Bronowice Cyclotron Center patient treatment facility using a clinically relevant proton pencil beam for brain tumor and craino-spinal treatment directed at a child phantom. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Correlated fission data measurements with DANCE and NEUANCE

DOE PAGES

Jandel, Marian; Baramsai, Baramsai; Bredeweg, Todd Allen; ...

2017-11-16

To enhance the capabilities of the DANCE array, a new detector array NEUANCE was developed to enable simultaneous measurements of prompt fission neutrons and γ rays. NEUANCE was designed and constructed using 21 stilbene organic scintillator crystals. It was installed in the central cavity of the DANCE array. Signals from the 160 BaF 2 detectors of DANCE and the 21 detectors of NEUANCE were merged into a newly designed high-density high-throughput data acquisition system. The excellent pulse shape discrimination properties of stilbene enabled detection of neutrons with energy thresholds as low as 30–40 keVee. A fission reaction tagging method wasmore » developed using a NEUANCE γ-ray or neutron signal. The probability of detecting a neutron from the spontaneous fission of 252Cf using NEUANCE is 47%. New correlated data for prompt fission neutrons and prompt fission rays were obtained for 252Cf using this high detection efficiency experimental setup. In conclusion, average properties of prompt fission neutron emission as a function of prompt fission γ-ray quantities were also obtained, suggesting that neutron and γ-ray emission in fission are correlated.« less

Proceedings of the 8th Matched-Field Processing Workshop, 12-14 June 1996,

DTIC Science & Technology

1996-10-01

and M. B. Porter Active Matched-Field Tracking (AMFT) ............................................ 29 Homer Bucker Matched-Field Track - Before - Detect (TBD...CD I- z - .4 U) - U :T 0 4,) 0j w CfI -ID 0 ci) CD) CD CD o0 0 C 0D CD 0C o 00 Matched-Field Track - Before - Detect (TBD) Processing using SWellEX...surfaces are used in a source-track search. Track - before - detect (TBD) processing makes use of this technique to extract source track information so that the

Realization of highly efficient hexagonal boron nitride neutron detectors

DOE PAGES

Maity, A.; Doan, T. C.; Li, J.; ...

2016-08-16

Here, we report the achievement of highly efficient 10B enriched hexagonal boron nitride (h- 10BN) direct conversion neutron detectors. These detectors were realized from freestanding 4-in. diameter h- 10BN wafers 43 μm in thickness obtained from epitaxy growth and subsequent mechanical separation from sapphire substrates. Both sides of the film were subjected to ohmic contact deposition to form a simple vertical “photoconductor-type” detector. Transport measurements revealed excellent vertical transport properties including high electrical resistivity (>10 13 Ω cm) and mobility-lifetime (μτ) products. A much larger μτ product for holes compared to that of electrons along the c-axis of h- BNmore » was observed, implying that holes (electrons) behave like majority (minority) carriers in undoped h- BN. Exposure to thermal neutrons from a californium-252 ( 252Cf) source moderated by a high density polyethylene moderator reveals that 43 μm h- 10BN detectors possess 51.4% detection efficiency at a bias voltage of 400 V, which is the highest reported efficiency for any semiconductor-based neutron detector. The results point to the possibility of obtaining highly efficient, compact solid-state neutron detectors with high gamma rejection and low manufacturing and maintenance costs.« less

Transplant center volume and outcomes in lung transplantation for cystic fibrosis.

PubMed

Hayes, Don; Sweet, Stuart C; Benden, Christian; Kopp, Benjamin T; Goldfarb, Samuel B; Visner, Gary A; Mallory, George B; Tobias, Joseph D; Tumin, Dmitry

2017-04-01

Transplant volume represents lung transplant (LTx) expertise and predicts outcomes, so we sought to determine outcomes related to center volumes in cystic fibrosis (CF). United Network for Organ Sharing data were queried for patients with CF in the United States (US) receiving bilateral LTx from 2005 to 2015. Multivariable Cox regression was used to model survival to 1 year and long-term (>1 year) survival, conditional on surviving at least 1 year. A total of 2025 patients and 67 centers were included in the analysis. The median annual LTx volumes were three in CF [interquartile range (IQR): 2, 6] and 17 in non-CF (IQR: 8, 33). Multivariable Cox regression in cases with complete data and surviving at least 1 year (n = 1510) demonstrated that greater annual CF LTx volume (HR per 10 LTx = 0.66; 95% CI: 0.49, 0.89; P = 0.006) but not greater non-CF LTx volume (HR = 1.00; 95% CI: 0.96, 1.05; P = 0.844) was associated with improved long-term survival in LTx recipients with CF. A Wald interaction test confirmed that CF LTx volume was more strongly associated with long-term outcomes than non-CF LTx volume (P = 0.012). In a US cohort, center volume was not associated with 1-year survival. CF-specific expertise predicted improved long-term outcomes of LTx for CF, whereas general LTx expertise was unassociated with CF patients' survival. © 2016 Steunstichting ESOT.

Survival in Patients with Advanced Non-cystic Fibrosis Bronchiectasis Versus Cystic Fibrosis on the Waitlist for Lung Transplantation.

PubMed

Hayes, Don; Kopp, Benjamin T; Tobias, Joseph D; Woodley, Frederick W; Mansour, Heidi M; Tumin, Dmitry; Kirkby, Stephen E

2015-12-01

Survival in non-cystic fibrosis (CF) bronchiectasis is not well studied. The United Network for Organ Sharing database was queried from 1987 to 2013 to compare survival in adult patients with non-CF bronchiectasis to patients with CF listed for lung transplantation (LTx). Each subject was tracked from waitlist entry date until death or censoring to determine survival differences between the two groups. Of 2112 listed lung transplant candidates with bronchiectasis (180 non-CF, 1932 CF), 1617 were used for univariate Cox and Kaplan-Meier survival function analysis, 1173 for multivariate Cox models, and 182 for matched-pairs analysis based on propensity scores. Compared to CF, patients with non-CF bronchiectasis had a significantly lower mortality by univariate Cox analysis (HR 0.565; 95 % CI 0.424, 0.754; p < 0.001). Adjusting for potential confounders, multivariate Cox models identified a significant reduction in risk for death associated with non-CF bronchiectasis who were lung transplant candidates (HR 0.684; 95 % CI 0.475, 0.985; p = 0.041). Results were consistent in multivariate models adjusting for pulmonary hypertension and forced expiratory volume in one second. Non-CF bronchiectasis with advanced lung disease was associated with significantly lower mortality hazard compared to CF bronchiectasis on the waitlist for LTx. Separate referral and listing criteria for LTx in non-CF and CF populations should be considered.

Improved charge breeding efficiency of light ions with an electron cyclotron resonance ion source

DOE Office of Scientific and Technical Information (OSTI.GOV)

Vondrasek, R.; Kutsaev, Sergey; Delahaye, P.

2012-11-15

The Californium Rare Isotope Breeder Upgrade is a new radioactive beam facility for the Argonne Tandem Linac Accelerator System (ATLAS). The facility utilizes a {sup 252}Cf fission source coupled with an electron cyclotron resonance ion source to provide radioactive beam species for the ATLAS experimental program. The californium fission fragment distribution provides nuclei in the mid-mass range which are difficult to extract from production targets using the isotope separation on line technique and are not well populated by low-energy fission of uranium. To date the charge breeding program has focused on optimizing these mid-mass beams, achieving high charge breeding efficienciesmore » of both gaseous and solid species including 14.7% for the radioactive species {sup 143}Ba{sup 27+}. In an effort to better understand the charge breeding mechanism, we have recently focused on the low-mass species sodium and potassium which up to present have been difficult to charge breed efficiently. Unprecedented charge breeding efficiencies of 10.1% for {sup 23}Na{sup 7+} and 17.9% for {sup 39}K{sup 10+} were obtained injecting stable Na{sup +} and K{sup +} beams from a surface ionization source.« less

Improved charge breeding efficiency of light ions with an electron cyclotron resonance ion source

DOE Office of Scientific and Technical Information (OSTI.GOV)

Vondrasek, R.; Delahaye, P.; Kutsaev, Sergey

2012-11-01

The Californium Rare Isotope Breeder Upgrade is a new radioactive beam facility for the Argonne Tandem Linac Accelerator System (ATLAS). The facility utilizes a 252Cf fission source coupled with an electron cyclotron resonance ion source to provide radioactive beam species for the ATLAS experimental program. The californium fission fragment distribution provides nuclei in the mid-mass range which are difficult to extract from production targets using the isotope separation on line technique and are not well populated by low-energy fission of uranium. To date the charge breeding program has focused on optimizing these mid-mass beams, achieving high charge breeding efficiencies ofmore » both gaseous and solid species including 14.7% for the radioactive species 143Ba27+. In an effort to better understand the charge breeding mechanism, we have recently focused on the low-mass species sodium and potassium which up to present have been difficult to charge breed efficiently. Unprecedented charge breeding efficiencies of 10.1% for 23Na7+ and 17.9% for 39K10+ were obtained injecting stable Na+ and K+ beams from a surface ionization source.« less

The impact of accelerometer wear location on the relationship between step counts and arterial stiffness in adults treated for hypertension and diabetes.

PubMed

Cooke, Alexandra B; Daskalopoulou, Stella S; Dasgupta, Kaberi

2018-04-01

Accelerometer placement at the wrist is convenient and increasingly adopted despite less accurate physical activity (PA) measurement than with waist placement. Capitalizing on a study that started with wrist placement and shifted to waist placement, we compared associations between PA measures derived from different accelerometer locations with a responsive arterial health indicator, carotid-femoral pulse wave velocity (cfPWV). Cross-sectional study. We previously demonstrated an inverse association between waist-worn pedometer-assessed step counts (Yamax SW-200, 7 days) and cfPWV (-0.20m/s, 95% CI -0.28, -0.12 per 1000 step/day increment) in 366 adults. Participants concurrently wore accelerometers (ActiGraph GT3X+), most at the waist but the first 46 at the wrist. We matched this subgroup with participants from the 'waist accelerometer' group (sex, age, and pedometer-assessed steps/day) and assessed associations with cfPWV (applanation tonometry, Sphygmocor) separately in each subgroup through linear regression models. Compared to the waist group, wrist group participants had higher step counts (mean difference 3980 steps/day; 95% CI 2517, 5443), energy expenditure (967kcal/day, 95% CI 755, 1179), and moderate-to-vigorous-PA (138min; 95% CI 114, 162). Accelerometer-assessed step counts (waist) suggested an association with cfPWV (-0.28m/s, 95% CI -0.58, 0.01); but no relationship was apparent with wrist-assessed steps (0.02m/s, 95% CI -0.24, 0.27). Waist but not wrist ActiGraph PA measures signal associations between PA and cfPWV. We urge researchers to consider the importance of wear location choice on relationships with health indicators. Copyright © 2017 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

Investigation of the effect of gelatine, egg albumin and cross-flow microfiltration on the phenolic composition of Pinotage wine.

PubMed

Oberholster, A; Carstens, L M; du Toit, W J

2013-06-01

The effect of fining and cross-flow microfiltration on the phenolic composition of red wine was investigated. Both gelatine (G) and egg albumin (EA) fining decreased the mean degree of polymerisation (mDP) of tannin significantly by 26.4% and 25.2%, respectively, compared to the control (C). Cross-flow microfiltration (CF) also decreased the mDP significantly by 25%. Thus, the fining agents and cross-flow microfiltration selectively removed the highly polymerised phenols. After 3.5 months of bottle ageing, differences between the different treatments and the control decreased. CF had the most significant effect on the flavan-3-ol and polymeric phenol (tannin) content of the wines compared to the control followed by G fining. CF and EA treatments significantly decreased the total pigment content compared to C. CF was also the only treatment that could be distinguished from the other treatments by sensory analysis. All treatments improved clarity of the wines with cross-flow microfiltration having the largest effect. Copyright © 2012 Elsevier Ltd. All rights reserved.

Levels and determinants of complementary feeding based on meal frequency among children of 6 to 23 months in Bangladesh.

PubMed

Chowdhury, Mohammad Rocky Khan; Rahman, Md Shafiur; Khan, Md Mobarak Hossain

2016-09-07

Information concerning complementary feeding (CF) practice during infancy and early childhood is still scarce in Bangladesh. Therefore, this study aimed to estimate the level of CF among children of 6-23 months and identify individual, household and community level determinants in Bangladesh. Secondary data from the Bangladesh Demographic Health Survey (BDHS) 2011 was used. A total of 2,373 children aged 6-23 months were selected. A simplified index called "dimension index" was used to estimate the level of CF. The score of this index was used either as continuous or categorical dependent variables. The highest score based on dimension index is associated to an adequate CF. Statistical analyses and tests were guided by types of variables. Finally, multivariable logistic regression (binary and multinomial) analyses were performed to identify the significant determinants of CF. The overall level of CF among children of 6-23 months was low. More than 90 % of children experienced either no (2.9 %) or inadequate CF (92.7 %). According to bivariable analyses, mean levels of CF as well as percentages of no/inadequate CF were significantly lower among children of the youngest age group, uneducated parents, unemployed/laborer fathers, socio-economically poor families, food insecure families and rural areas. No weekly exposure to mass media (namely watching TV and reading newspapers/magazines) also revealed significant associations with CF. However, only few variables remained significant for adequate CF in the multivariable logistic regression analysis. For example, the likelihood of experiencing adequate CF was significantly lower among children of 6-11 months (OR: 0.22, 95 % CI: 0.10-0.47), children of illiterate fathers (OR: 0.32, 95 % CI: 0.11-0.95) and socio-economically middle-class families (OR: 0.28, 95 % CI: 0.09-0.86) as compared to their reference categories. A high level of inadequate CF leading to malnutrition may cause serious health problems among children of 6-23 months in Bangladesh. Vulnerable groups of children (e.g., the children aged 6 to 11 months and children of illiterate fathers), who received low levels of adequate CF, should be targeted by government and other stakeholders while developing strategies and interventions in order to improve overall situation of CF in Bangladesh.

Respiratory infection rates differ between geographically distant paediatric cystic fibrosis cohorts

PubMed Central

Hart, Emily; Turkovic, Lidija; Padros-Goossens, Marc; Stick, Stephen M.; Ranganathan, Sarath C.

2016-01-01

Respiratory infections are a major cause of pulmonary decline in children with cystic fibrosis (CF). We compared the prevalence of infection in early life at geographically distant CF treatment centres participating in the same surveillance programme in Australia. Lower airway microbiology, inflammation and structural lung disease at annual review were evaluated for 260 children 0–8 years old with CF at 1032 visits to CF treatment centres in Melbourne or Perth. Melbourne patients were more likely to be culture-positive for common respiratory pathogens at all age groups (odds ratio (OR) 1.85, 95% CI 1.33–2.58). Subjects <2 years old in Melbourne were also more likely to have neutrophil elastase present (OR 3.11, 95% CI 1.62–5.95). Bronchiectasis (OR 2.02, 95% CI 1.21–3.38) and air trapping (OR 2.53, 95% CI 1.42–4.51) in subjects 2–5 years old was more common in Melbourne subjects. The severity of structural lung disease was also worse in Melbourne patients >5 years old. Patients at both centres had a similar rate of hospitalisations and prescribed antibiotics. No procedural differences were identified that could explain the disparity between pathogen prevalence. Geographical differences in early acquisition of infection may contribute to variability in outcomes between CF centres. PMID:27957481

Development of a thin scintillation films fission-fragment detector and a novel neutron source

NASA Astrophysics Data System (ADS)

Rusev, G.; Jandel, M.; Baramsai, B.; Bond, E. M.; Bredeweg, T. A.; Couture, A.; Daum, J. K.; Favalli, A.; Ianakiev, K. D.; Iliev, M. L.; Mosby, S.; Roman, A. R.; Springs, R. K.; Ullmann, J. L.; Walker, C. L.

2015-08-01

Investigation of prompt fission and neutron-capture Υ rays from fissile actinide samples at the Detector for Advanced Neutron Capture Experiments (DANCE) requires use of a fission-fragment detector to provide a trigger or a veto signal. A fission-fragment detector based on thin scintillating films and silicon photomultipliers has been built to serve as a trigger/veto detector in neutron-induced fission measurements at DANCE. The fissile material is surrounded by scintillating films providing a 4π detection of the fission fragments. The scintillations were registered with silicon photomultipliers. A measurement of the 235U(n,f) reaction with this detector at DANCE revealed a correct time-of-flight spectrum and provided an estimate for the efficiency of the prototype detector of 11.6(7)%. Design and test measurements with the detector are described. A neutron source with fast timing has been built to help with detector-response measurements. The source is based on the neutron emission from the spontaneous fission of 252Cf and the same type of scintillating films and silicon photomultipliers. Overall time resolution of the source is 0.3 ns. Design of the source and test measurements with it are described. An example application of the source for determining the neutron/gamma pulse-shape discrimination by a stilbene crystal is given.

Pretransplant Aspergillus colonization of cystic fibrosis patients and the incidence of post-lung transplant invasive aspergillosis.

PubMed

Luong, Me-Linh; Chaparro, Cecilia; Stephenson, Anne; Rotstein, Coleman; Singer, Lianne G; Waters, Valerie; Azad, Sassan; Keshavjee, Shaf; Tullis, Elizabeth; Husain, Shahid

2014-02-15

Invasive aspergillosis (IA) is an important cause of morbidity and mortality among patients undergoing lung transplant. Cystic fibrosis-lung transplant recipients (CF-LTRs) may be at greater risk of IA following lung transplantation because of the presence of Aspergillus in their airways before transplantation. This study evaluated the impact of pretransplant Aspergillus colonization on the risk for IA among CF-LTRs. A single-center retrospective cohort study of CF-LTRs was conducted between 2006 and 2010. Respiratory tract cultures before transplantation were reviewed to identify patients with pretransplant Aspergillus colonization. Patients with positive Aspergillus sputum culture or positive bronchoalvelolar lavage (BAL) galactomannan after transplantation were classified as having colonization or disease according to the International Society of Heart and Lung Transplantation criteria. A total of 93 CF patients underwent lung transplantation. Seventy percent (65/93) of CF-LTRs had pretransplant Aspergillus colonization. Thirty-six patients had positive intraoperative Aspergillus culture from the native lung BAL. Overall, 22.5% (20/93) of CF-LTRs developed IA. Median time to IA was 42 days following transplantation. Positive intraoperative Aspergillus culture (OR 4.36, 95% CI 1.35-14.05, P=0.01) and treatment for acute cellular rejection within 90 days after transplantation (OR 3.53, 95% CI 1.03-12.15, P=0.05) were independent risk factors for IA. Antifungal prophylaxis was administered to 61% (57/93) of CF-LTRs. One-year mortality rate was 16% (15/93). IA was not associated with increased risk of death (OR 2.10, 95% CI 0.62-7.06, P=0.23). Pretransplant Aspergillus colonization is frequent among CF-LTRs and a positive intraoperative Aspergillus culture produced a fourfold higher risk of developing IA.

Seasonality of acquisition of respiratory bacterial pathogens in young children with cystic fibrosis.

PubMed

Psoter, Kevin J; De Roos, Anneclaire J; Wakefield, Jon; Mayer, Jonathan D; Rosenfeld, Margaret

2017-06-09

Seasonal variations are often observed for respiratory tract infections; however, limited information is available regarding seasonal patterns of acquisition of common cystic fibrosis (CF)-related respiratory pathogens. We previously reported differential seasonal acquisition of Pseudomonas aeruginosa in young children with CF and no such variation for methicillin-susceptible Staphylococcus aureus acquisition. The purpose of this study was to describe and compare the seasonal incidence of acquisition of other respiratory bacterial pathogens in young children with CF. We conducted a retrospective study to describe and compare the seasonal incidence of methicillin-resistant Staphylococcus aureus (MRSA), Stenotrophomonas maltophilia, Achromobacter xylosoxidans, and Haemophilus influenzae acquisition in young CF patients residing in the U.S. using the Cystic Fibrosis Foundation National Patient Registry, 2003-2009. Log-linear overdispersed Poisson regression was used to evaluate seasonal acquisition of each of these pathogens. A total of 4552 children met inclusion criteria. During follow-up 910 (20%), 1161 (26%), 228 (5%), and 2148 (47%) children acquired MRSA, S. maltophilia, A. xylosoxidans and H. influenzae, respectively. Compared to winter season, MRSA was less frequently acquired in spring (Incidence Rate Ratio [IRR]: 0.79; 95% Confidence Interval [CI]: 0.65, 0.96) and summer (IRR: 0.69; 95% CI: 0.57, 0.84) seasons. Similarly, a lower rate of A. xylosoxidans acquisition was observed in spring (IRR: 0.59; 95% CI: 0.39, 0.89). For H. influenzae, summer (IRR: 0.88; 95% CI: 0.78, 0.99) and autumn (IRR: 0.78; 95% CI: 0.69, 0.88) seasons were associated with lower acquisition rates compared to winter. No seasonal variation was observed for S. maltophilia acquisition. Acquisition of CF-related respiratory pathogens displays seasonal variation in young children with CF, with the highest rate of acquisition for most pathogens occurring in the winter. Investigation of factors underlying these observed associations may contribute to our understanding of the aetiology of these infections and guide future infection control strategies.

Incidence and clinical impact of respiratory viruses in adults with cystic fibrosis.

PubMed

Flight, William G; Bright-Thomas, Rowland J; Tilston, Peter; Mutton, Kenneth J; Guiver, Malcolm; Morris, Julie; Webb, A Kevin; Jones, Andrew M

2014-03-01

Viral respiratory infection (VRI) is a common cause of pulmonary exacerbations in children with cystic fibrosis (CF). The importance of VRI in adult CF populations is unclear. To determine the incidence and clinical impact of VRI among adults with CF. One hundred adults with CF were followed up prospectively for 12 months. Sputum, nose swabs and throat swabs were collected every 2 months and at onset of pulmonary exacerbation. PCR assays for adenovirus, influenza A&B, human metapneumovirus, parainfluenza 1-3, respiratory syncytial virus and human rhinovirus were performed on each sample. Symptom scores, spirometry and inflammatory markers were measured at each visit. One or more respiratory viruses were detected in 191/626 (30.5%) visits. Human rhinovirus accounted for 72.5% of viruses. Overall incidence of VRI was 1.66 (95% CI 1.39 to 1.92) cases/patient-year. VRI was associated with increased risk of pulmonary exacerbation (OR=2.19; 95% CI 1.56 to 3.08; p<0.001) and prescription of antibiotics (OR=2.26; 95% CI 1.63 to 3.13; p<0.001). Virus-positive visits were associated with higher respiratory symptom scores and greater C-reactive protein levels. Virus-positive exacerbations had a lower acute fall in FEV1 than virus-negative exacerbations (12.7% vs 15.6%; p=0.040). The incidence of exacerbations, but not VRI, was associated with greater lung function decline over 12 months (-1.79% per pulmonary exacerbation/year; 95% CI -3.4 to -0.23; p=0.025). VRI is common in adults with CF and is associated with substantial morbidity. Respiratory viruses are a potential therapeutic target in CF lung disease.

Aircraft Radiation Shield Experiments--Preflight Laboratory Testing

NASA Technical Reports Server (NTRS)

Singleterry, Robert C., Jr.; Shinn, Judy L.; Wilson, John W.; Maiden, Donald L.; Thibeault, Sheila A.; Badavi, Francis F.; Conroy, Thomas; Braby, Leslie

1999-01-01

In the past, measurements onboard a research Boeing 57F (RB57-F) aircraft have demonstrated that the neutron environment within the aircraft structure is greater than that in the local external environment. Recent studies onboard Boeing 737 commercial flights have demonstrated cabin variations in radiation exposure up to 30 percent. These prior results were the basis of the present study to quantify the potential effects of aircraft construction materials on the internal exposures of the crew and passengers. The present study constitutes preflight measurements using an unmoderated Cf-252 fission neutron source to quantify the effects of three current and potential aircraft materials (aluminum, titanium, and graphite-epoxy composite) on the fast neutron flux. Conclusions about the effectiveness of the three selected materials for radiation shielding must wait until testing in the atmosphere is complete; however, it is clear that for shielding low-energy neutrons, the composite material is an improved shielding material over aluminum or titanium.

In-vivo assessment of total body protein in rats by prompt-γ neutron activation analysis

NASA Astrophysics Data System (ADS)

Stamatelatos, Ion E.; Boozer, Carol N.; Ma, Ruimei; Yasumura, Seiichi

1997-02-01

A prompt-(gamma) neutron activation analysis facility for in vivo determination of total body protein (TBP) in rats has been designed. TBP is determined in vivo by assessment of total body nitrogen. The facility is based on a 252Cf radionuclide neutron source within a heavy water moderator assembly and two NaI(Tl) scintillation detectors. The in vivo precision of the technique, as estimated by three repeated measurements of 15 rats is 6 percent, for a radiation dose equivalent of 60 mSv. The radiation dose per measurement is sufficiently low to enable serial measurements on the same animal. MCNP-4A Monte Carlo transport code was utilized to calculate thermal neutron flux correction factors to account for differences in size and shape of the rats and calibration phantoms. Good agrement was observed in comparing body nitrogen assessment by prompt-(gamma) neutron activation and chemical carcass analysis.

Characterization of boron coated vitreous carbon foam for neutron detection

NASA Astrophysics Data System (ADS)

Lavelle, C. M.; Deacon, Ryan M.; Hussey, Daniel S.; Coplan, Michael; Clark, Charles W.

2013-11-01

Reticulated vitreous carbon (RVC) foams coated with 3-11 μm thick layers of boron carbide (B4C) are experimentally characterized for use as an active material for neutron detection. The potential advantage of this material over thin films is that it can be fabricated in any shape and its porous structure may enhance the emission surface area for ionizing charged particles following thermal neutron capture. A coated foam is also advantageous because the neutron-absorbing material is only on the surface, which is more efficient for α particle emission on a per captured neutron basis. Measurements of the B4C layer thickness of an RVC coated foam, and determination of its elemental composition, are performed using scanning electron microscopy. Neutron transmission measurements using neutron radiography are presented and α particle emission from the coated foam in response to a moderated 252Cf thermal neutron source is demonstrated.

Late-time emission of prompt fission γ rays

DOE PAGES

Talou, Patrick; Kawano, Toshihiko; Stetcu, Ionel; ...

2016-12-22

The emission of prompt fission γ rays within a few nanoseconds to a few microseconds following the scission point is studied in the Hauser-Feshbach formalism applied to the deexcitation of primary excited fission fragments. Neutron and γ-ray evaporations from fully accelerated fission fragments are calculated in competition at each stage of the decay, and the role of isomers in the fission products, before β decay, is analyzed. The time evolution of the average total γ-ray energy, the average total γ-ray multiplicity, and the fragment-specific γ-ray spectra is presented in the case of neutron-induced fission reactions of 235U and 239Pu, asmore » well as spontaneous fission of 252Cf. The production of specific isomeric states is calculated and compared to available experimental data. About 7% of all prompt fission γ rays are predicted to be emitted between 10 ns and 5 μs following fission, in the case of 235U and 239Pu( nth,f) reactions, and up to 3% in the case of 252Cf spontaneous fission. The cumulative average total γ-ray energy increases by 2% to 5% in the same time interval. Lastly, those results are shown to be robust against significant changes in the model input parameters.« less

Prompt fission γ-ray data from spontaneous fission and the mechanism of fission-fragment de-excitation

NASA Astrophysics Data System (ADS)

Oberstedt, Stephan; Dragic, Aleksandar; Gatera, Angelique; Göök, Alf; Hambsch, Franz-Josef; Oberstedt, Andreas

2017-09-01

The investigation of prompt γ-ray emission in nuclear fission has a great relevance for the assessment of prompt heat generation in a reactor core and for the better understanding of the de-excitation mechanism of fission fragments. Some years ago experimental data was scarce and available only from a few fission reactions, 233,235U(nth, f), 239Pu(nth, f), and 252Cf(sf). Initiated by a high priority data request published by the OECD/NEA a dedicated prompt fission γ-ray measurement program is being conducted at the Joint Research Centre Geel. In recent years we obtained new and accurate prompt fission γ-ray spectrum (PFGS) characteristics (average number of photons per fission, average total energy per fission and mean photon energy) from 252Cf(sf), 235U(nth, f) and 239,241Pu(nth, f) within 2% of uncertainty. In order to understand the dependence of prompt fission γ-ray emission on the compound nuclear mass and excitation energy, we started a first measurement campaign on spontaneously fissioning plutonium and curium isotopes. Results on PFGS characteristics from 240,242Pu(sf) show a dependence on the fragment mass distribution rather than on the average prompt neutron multiplicity, pointing to a more complex competition between prompt fission γ-ray and neutron emission.

Is palivizumab effective as a prophylaxis of respiratory syncytial virus infections in cystic fibrosis patients? A meta-analysis.

PubMed

Sánchez-Solis, M; Gartner, S; Bosch-Gimenez, V; Garcia-Marcos, L

2015-01-01

Infections by respiratory syncytial virus (RSV) are more severe in patients with cystic fibrosis (CF), and many CF units use palivizumab as prophylaxis; however, information about palivizumab efficacy in CF patients is almost lacking. A literature search up to December 2012 on the morbidity of RSV bronchiolitis in CF patients and on the safety and efficacy of palivizumab in those patients was performed. A random-effects meta-analysis was conducted for those studies meeting pre-specified search criteria. Historical controls were allowed. The number of patients who received palivizumab was 354 and the hospital admission rate was 0.018 (95% CI 0.0077-0.048). The corresponding number in the non-treated groups was 463 patients with an admission rate of 0.126 (95% CI 0.086-0.182) (Q=13.9; p<0.001). Palivizumab may have a role in the prevention of severe lower airway infection by RSV in CF patients. Copyright © 2013 SEICAP. Published by Elsevier Espana. All rights reserved.

Assessment of CF lung disease using motion corrected PROPELLER MRI: a comparison with CT.

PubMed

Ciet, Pierluigi; Serra, Goffredo; Bertolo, Silvia; Spronk, Sandra; Ros, Mirco; Fraioli, Francesco; Quattrucci, Serena; Assael, M Baroukh; Catalano, Carlo; Pomerri, Fabio; Tiddens, Harm A W M; Morana, Giovanni

2016-03-01

To date, PROPELLER MRI, a breathing-motion-insensitive technique, has not been assessed for cystic fibrosis (CF) lung disease. We compared this technique to CT for assessing CF lung disease in children and adults. Thirty-eight stable CF patients (median 21 years, range 6-51 years, 22 female) underwent MRI and CT on the same day. Study protocol included respiratory-triggered PROPELLER MRI and volumetric CT end-inspiratory and -expiratory acquisitions. Two observers scored the images using the CF-MRI and CF-CT systems. Scores were compared with intra-class correlation coefficient (ICC) and Bland-Altman plots. The sensitivity and specificity of MRI versus CT were calculated. MRI sensitivity for detecting severe CF bronchiectasis was 0.33 (CI 0.09-0.57), while specificity was 100% (CI 0.88-1). ICCs for bronchiectasis and trapped air were as follows: MRI-bronchiectasis (0.79); CT-bronchiectasis (0.85); MRI-trapped air (0.51); CT-trapped air (0.87). Bland-Altman plots showed an MRI tendency to overestimate the severity of bronchiectasis in mild CF disease and underestimate bronchiectasis in severe disease. Motion correction in PROPELLER MRI does not improve assessment of CF lung disease compared to CT. However, the good inter- and intra-observer agreement and the high specificity suggest that MRI might play a role in the short-term follow-up of CF lung disease (i.e. pulmonary exacerbations). PROPELLER MRI does not match CT sensitivity to assess CF lung disease. PROPELLER MRI has lower sensitivity than CT to detect severe bronchiectasis. PROPELLER MRI has good to very good intra- and inter-observer variability. PROPELLER MRI can be used for short-term follow-up studies in CF.

GENETIC MODIFIERS OF LIVER DISEASE IN CYSTIC FIBROSIS

PubMed Central

Bartlett, Jaclyn R.; Friedman, Kenneth J.; Ling, Simon C.; Pace, Rhonda G.; Bell, Scott C.; Bourke, Billy; Castaldo, Giuseppe; Castellani, Carlo; Cipolli, Marco; Colombo, Carla; Colombo, John L.; Debray, Dominique; Fernandez, Adriana; Lacaille, Florence; Macek, Milan; Rowland, Marion; Salvatore, Francesco; Taylor, Christopher J.; Wainwright, Claire; Wilschanski, Michael; Zemková, Dana; Hannah, William B.; Phillips, M. James; Corey, Mary; Zielenski, Julian; Dorfman, Ruslan; Wang, Yunfei; Zou, Fei; Silverman, Lawrence M.; Drumm, Mitchell L.; Wright, Fred A.; Lange, Ethan M.; Durie, Peter R.; Knowles, Michael R.

2013-01-01

Context A subset (~3–5%) of patients with cystic fibrosis (CF) develops severe liver disease (CFLD) with portal hypertension. Objective To assess whether any of 9 polymorphisms in 5 candidate genes (SERPINA1, ACE, GSTP1, MBL2, and TGFB1) are associated with severe liver disease in CF patients. Design, Setting, and Participants A 2-stage design was used in this case–control study. CFLD subjects were enrolled from 63 U.S., 32 Canadian, and 18 CF centers outside of North America, with the University of North Carolina at Chapel Hill (UNC) as the coordinating site. In the initial study, we studied 124 CFLD patients (enrolled 1/1999–12/2004) and 843 CF controls (patients without CFLD) by genotyping 9 polymorphisms in 5 genes previously implicated as modifiers of liver disease in CF. In the second stage, the SERPINA1 Z allele and TGFB1 codon 10 genotype were tested in an additional 136 CFLD patients (enrolled 1/2005–2/2007) and 1088 CF controls. Main Outcome Measures We compared differences in distribution of genotypes in CF patients with severe liver disease versus CF patients without CFLD. Results The initial study showed CFLD to be associated with the SERPINA1 (also known as α1-antiprotease and α1-antitrypsin) Z allele (P value=3.3×10−6; odds ratio (OR) 4.72, 95% confidence interval (CI) 2.31–9.61), and with transforming growth factor β-1 (TGFB1) codon 10 CC genotype (P=2.8×10−3; OR 1.53, CI 1.16–2.03). In the replication study, CFLD was associated with the SERPINA1 Z allele (P=1.4×10−3; OR 3.42, CI 1.54–7.59), but not with TGFB1 codon 10. A combined analysis of the initial and replication studies by logistic regression showed CFLD to be associated with SERPINA1 Z allele (P=1.5×10−8; OR 5.04, CI 2.88–8.83). Conclusion The SERPINA1 Z allele is a risk factor for liver disease in CF. Patients who carry the Z allele are at greater odds (OR ~5) to develop severe liver disease with portal hypertension. PMID:19738092

A neutron Albedo system with time rejection for landmine and IED detection

NASA Astrophysics Data System (ADS)

Kovaltchouk, V. D.; Andrews, H. R.; Clifford, E. T. H.; Faust, A. A.; Ing, H.; McFee, J. E.

2011-10-01

A neutron Albedo system has been developed for imaging of buried landmines and improvised explosive devices (IEDs). It involves irradiating the ground with fast neutrons and subsequently detecting the thermalized neutrons that return. A scintillating 6Li loaded ZnS(Ag) screen with a sensitive area of 40 cm×40 cm is used as a thermal neutron detector. Scintillation light is captured by orthogonal arrays of wavelength-shifting fibers placed on either side of the scintillator surface and then transferred to X and Y multi-pixel PMTs. A timing circuit, used with pulsed neutron sources, records the time when a neutron detection takes place relative to an external synchronization pulse from the pulsed source. Experimental tests of the Albedo system performance have been done in a sand box with a 252Cf neutron source (no time gating) and with pulsed D-D (2.6 MeV) neutrons from the Defense R&D Ottawa Van de Graaff accelerator (with time gating). Information contained in the time evolution of the thermal neutron field provided improved detection capability and image reconstruction. The detector design is described and experimental results are discussed.

A Radiation Laboratory Curriculum Development at Western Kentucky University

NASA Astrophysics Data System (ADS)

Barzilov, Alexander P.; Novikov, Ivan S.; Womble, Phil C.

2009-03-01

We present the latest developments for the radiation laboratory curriculum at the Department of Physics and Astronomy of Western Kentucky University. During the last decade, the Applied Physics Institute (API) at WKU accumulated various equipment for radiation experimentation. This includes various neutron sources (computer controlled d-t and d-d neutron generators, and isotopic 252 Cf and PuBe sources), the set of gamma sources with various intensities, gamma detectors with various energy resolutions (NaI, BGO, GSO, LaBr and HPGe) and the 2.5-MeV Van de Graaff particle accelerator. XRF and XRD apparatuses are also available for students and members at the API. This equipment is currently used in numerous scientific and teaching activities. Members of the API also developed a set of laboratory activities for undergraduate students taking classes from the physics curriculum (Nuclear Physics, Atomic Physics, and Radiation Biophysics). Our goal is to develop a set of radiation laboratories, which will strengthen the curriculum of physics, chemistry, geology, biology, and environmental science at WKU. The teaching and research activities are integrated into real-world projects and hands-on activities to engage students. The proposed experiments and their relevance to the modern status of physical science are discussed.

Multicenter Retrospective Study of Cefmetazole and Flomoxef for Treatment of Extended-Spectrum-β-Lactamase-Producing Escherichia coli Bacteremia

PubMed Central

Yamamoto, Masaki; Nagao, Miki; Komori, Toshiaki; Fujita, Naohisa; Hayashi, Akihiko; Shimizu, Tsunehiro; Watanabe, Harumi; Doi, Shoichi; Tanaka, Michio; Takakura, Shunji; Ichiyama, Satoshi

2015-01-01

The efficacy of cefmetazole and flomoxef (CF) for the treatment of patients with extended-spectrum β-lactamase-producing Escherichia coli (ESBL-EC) bacteremia (ESBL-CF group) was compared with that of carbapenem treatment for ESBL-EC patients (ESBL-carbapenem group) and with that of CF treatment in patients with non-ESBL-EC bacteremia (non-ESBL-CF group). Adult patients treated for E. coli bacteremia in four hospitals were retrospectively evaluated. The 30-day mortality rates in patients belonging to the ESBL-CF, ESBL-carbapenem, and non-ESBL-CF groups were compared as 2 (empirical and definitive therapy) cohorts. The adjusted hazard ratios (aHRs) for mortality were calculated using Cox regression models with weighting according to the inverse probability of propensity scores for receiving CF or carbapenem treatment. The empirical-therapy cohort included 104 patients (ESBL-CF, 26; ESBL-carbapenem, 45; non-ESBL-CF, 33), and the definitive-therapy cohort included 133 patients (ESBL-CF, 59; ESBL-carbapenem, 54; non-ESBL-CF, 20). The crude 30-day mortality rates for patients in the ESBL-CF, ESBL-carbapenem, and non-ESBL-CF groups were, respectively, 7.7%, 8.9%, and 3.0% in the empirical-therapy cohort and 5.1%, 9.3%, and 5.0% in the definitve-therapy cohort. In patients without hematological malignancy and neutropenia, CF treatment for ESBL-EC patients was not associated with mortality compared with carbapenem treatment (empirical-therapy cohort: aHR, 0.87; 95% confidence interval [CI], 0.11 to 6.52; definitive therapy cohort: aHR, 1.04; CI, 0.24 to 4.49). CF therapy may represent an effective alternative to carbapenem treatment for patients with ESBL-EC bacteremia for empirical and definitive therapy in adult patients who do not have hematological malignancy and neutropenia. PMID:26100708

Multicenter retrospective study of cefmetazole and flomoxef for treatment of extended-spectrum-β-lactamase-producing Escherichia coli bacteremia.

PubMed

Matsumura, Yasufumi; Yamamoto, Masaki; Nagao, Miki; Komori, Toshiaki; Fujita, Naohisa; Hayashi, Akihiko; Shimizu, Tsunehiro; Watanabe, Harumi; Doi, Shoichi; Tanaka, Michio; Takakura, Shunji; Ichiyama, Satoshi

2015-09-01

The efficacy of cefmetazole and flomoxef (CF) for the treatment of patients with extended-spectrum β-lactamase-producing Escherichia coli (ESBL-EC) bacteremia (ESBL-CF group) was compared with that of carbapenem treatment for ESBL-EC patients (ESBL-carbapenem group) and with that of CF treatment in patients with non-ESBL-EC bacteremia (non-ESBL-CF group). Adult patients treated for E. coli bacteremia in four hospitals were retrospectively evaluated. The 30-day mortality rates in patients belonging to the ESBL-CF, ESBL-carbapenem, and non-ESBL-CF groups were compared as 2 (empirical and definitive therapy) cohorts. The adjusted hazard ratios (aHRs) for mortality were calculated using Cox regression models with weighting according to the inverse probability of propensity scores for receiving CF or carbapenem treatment. The empirical-therapy cohort included 104 patients (ESBL-CF, 26; ESBL-carbapenem, 45; non-ESBL-CF, 33), and the definitive-therapy cohort included 133 patients (ESBL-CF, 59; ESBL-carbapenem, 54; non-ESBL-CF, 20). The crude 30-day mortality rates for patients in the ESBL-CF, ESBL-carbapenem, and non-ESBL-CF groups were, respectively, 7.7%, 8.9%, and 3.0% in the empirical-therapy cohort and 5.1%, 9.3%, and 5.0% in the definitve-therapy cohort. In patients without hematological malignancy and neutropenia, CF treatment for ESBL-EC patients was not associated with mortality compared with carbapenem treatment (empirical-therapy cohort: aHR, 0.87; 95% confidence interval [CI], 0.11 to 6.52; definitive therapy cohort: aHR, 1.04; CI, 0.24 to 4.49). CF therapy may represent an effective alternative to carbapenem treatment for patients with ESBL-EC bacteremia for empirical and definitive therapy in adult patients who do not have hematological malignancy and neutropenia. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

Development of a technique using MCNPX code for determination of nitrogen content of explosive materials using prompt gamma neutron activation analysis method

NASA Astrophysics Data System (ADS)

Nasrabadi, M. N.; Bakhshi, F.; Jalali, M.; Mohammadi, A.

2011-12-01

Nuclear-based explosive detection methods can detect explosives by identifying their elemental components, especially nitrogen. Thermal neutron capture reactions have been used for detecting prompt gamma 10.8 MeV following radioactive neutron capture by 14N nuclei. We aimed to study the feasibility of using field-portable prompt gamma neutron activation analysis (PGNAA) along with improved nuclear equipment to detect and identify explosives, illicit substances or landmines. A 252Cf radio-isotopic source was embedded in a cylinder made of high-density polyethylene (HDPE) and the cylinder was then placed in another cylindrical container filled with water. Measurements were performed on high nitrogen content compounds such as melamine (C3H6N6). Melamine powder in a HDPE bottle was placed underneath the vessel containing water and the neutron source. Gamma rays were detected using two NaI(Tl) crystals. The results were simulated with MCNP4c code calculations. The theoretical calculations and experimental measurements were in good agreement indicating that this method can be used for detection of explosives and illicit drugs.

A reference aerosol for a radon reference chamber

NASA Astrophysics Data System (ADS)

Paul, Annette; Keyser, Uwe

1996-02-01

The measurement of radon and radon progenies and the calibration of their detection systems require the production and measurement of aerosols well-defined in size and concentration. In the German radon reference chamber, because of its unique chemical and physical properties, carnauba wax is used to produce standard aerosols. The aerosol size spectra are measured on-line by an aerosol measurement system in the range of 10 nm to 1 μm aerodynamic diameter. The experimental set-ups for the study of adsorption of radioactive ions on aerosols as function of their size and concentration will be described, the results presented and further adaptations for an aerosol jet introduced (for example, for the measurement of short-lived neutron-rich isotopes). Data on the dependence of aerosol radius, ion concentration and element selectivity is collected by using a 252Cf-sf source. The fission products of this source range widely in elements, isotopes and charges. Adsorption and the transport of radioactive ions on aerosols have therefore been studied for various ions for the first time, simultaneously with the aerosol size on-line spectrometry.

Work disability in adults with cystic fibrosis.

PubMed

Gillen, M; Lallas, D; Brown, C; Yelin, E; Blanc, P

1995-07-01

Greater numbers of persons with cystic fibrosis (CF) reach adulthood and, therefore, actively participate in the labor force. In this study, we estimated labor force participation rates and determined risk factors for work disability among persons with CF. We recruited 49 (73%) of 67 adults followed at one of two hospital-based CF centers. We ascertained employment history and CF-attributed work disability by structured questionnaire. Independently, we reviewed medical records for demographics and illness severity indicators. We analyzed potential risk factors for work disability by logistic regression analysis. All of those studied reported past or present labor force participation, consistent with high work motivation. Complete cessation of work attributed to CF was reported by 17 (35%; 95% CI, 21 to 49%). Although 23 (47%; 95% CI, 32 to 60%) of those surveyed stated that CF had affected career choice, only nine respondents had ever received career counselling and 16 had ever discussed job choice with their physicians. After adjusting for standard measures of disease severity by multiple logistic regression, age, adult diagnosis of CF, female gender, and single marital status, analyzed as a group, provided significant additional explanatory power to a predictive model of disability risk (model chi square [4 d.f.] = 11.5, p < 0.05). Health care professionals who design interventions targeted at work disability among persons with CF should address demographic factors as well as illness severity and should assess the vocational needs of persons with CF and the potential benefit of career counselling.

Environmental relevant concentrations of a chlorpyrifos commercial formulation affect two neotropical fish species, Cheirodon interruptus and Cnesterodon decemmaculatus.

PubMed

Bonifacio, Alejo Fabian; Ballesteros, María Laura; Bonansea, Rocío Inés; Filippi, Iohanna; Amé, María Valeria; Hued, Andrea Cecilia

2017-12-01

The increase of cultivated areas together with the intensive use of pesticides have greatly contributed to impair the quality of aquatic systems along different areas of South America. The main goal of the present study was to assess the effects of a commercial formulation of chlorpyrifos at environmentally relevant concentrations on two native fish species, Cheirodon interruptus and Cnesterodon decemmaculatus. Adult individuals were exposed during 48 h to the following concentrations: 0.084 nl/l (Ci-Cf 1) and 0.84 nl/l (Ci-CF 2) in C. interruptus (Ci) of Clorfox (CF), and 0.84 nl/l (Cd-CF 1) and 8.4 nl/l (Cd-CF 2) in C. decemmaculatus (Cd). Fish behavior was evaluated through locomotor activity and space usage variables. The activity of acetylcholinesterase (AChE) in brain and muscle, catalase (CAT) and glutathione-S-transferase (GST) in brain, liver, muscle and gills, and aspartate amino-transferase (AST), alanine amino-transferase (ALT), AST/ALT ratio and alkaline phosphatase (ALP) in liver, were measured. Both locomotor activity and space usage varied between the two species studied and between CF treatments. The enzyme activities showed significant variations in CAT for C. interruptus and in CAT, GST, AChE, AST, and AST/ALT for C. decemmaculatus under the exposure conditions. Given that both species responded to CF and the concentrations we tested are environmentally relevant, the presence of this pesticide in freshwater systems could impose a risk for populations of both native fish studied at field. Copyright © 2017 Elsevier Ltd. All rights reserved.

Increased Expression of Plasma-Induced ABCC1 mRNA in Cystic Fibrosis.

PubMed

Ideozu, Justin E; Zhang, Xi; Pan, Amy; Ashrafi, Zainub; Woods, Katherine J; Hessner, Martin J; Simpson, Pippa; Levy, Hara

2017-08-11

The ABCC1 gene is structurally and functionally related to the cystic fibrosis transmembrane conductance regulator gene ( CFTR ). Upregulation of ABCC1 is thought to improve lung function in patients with cystic fibrosis (CF); the mechanism underlying this effect is unknown. We analyzed the ABCC1 promoter single nucleotide polymorphism (SNP rs504348), plasma-induced ABCC1 mRNA expression levels, and ABCC1 methylation status and their correlation with clinical variables among CF subjects with differing CFTR mutations. We assigned 93 CF subjects into disease severity groups and genotyped SNP rs504348. For 23 CF subjects and 7 healthy controls, donor peripheral blood mononuclear cells (PBMCs) stimulated with plasma underwent gene expression analysis via qRT-PCR. ABCC1 promoter methylation was analyzed in the same 23 CF subjects. No significant correlation was observed between rs504348 genotypes and CF disease severity, but pancreatic insufficient CF subjects showed increased colonization with any form of Pseudomonas aeruginosa (OR = 3.125, 95% CI: 1.192-8.190) and mucoid P. aeruginosa (OR = 5.075, 95% CI: 1.307-28.620) compared to the pancreatic sufficient group. A significantly higher expression of ABCC1 mRNA was induced by CF plasma compared to healthy control plasma ( p < 0.001). CF subjects with rs504348 (CC/CG) also had higher mRNA expression compared to those with the ancestral GG genotype ( p < 0.005). ABCC1 promoter was completely unmethylated; therefore, we did not detect any association between methylation and CF disease severity. In silico predictions suggested that histone modifications are crucial for regulating ABCC1 expression in PBMCs. Our results suggest that ABCC1 expression has a role in CFTR activity thereby increasing our understanding of the molecular underpinnings of the clinical heterogeneity in CF.

Characterization of a prototype neutron portal monitor detector

NASA Astrophysics Data System (ADS)

Nakhoul, Nabil

The main objective of this thesis is to provide characterization measurements on a prototype neutron portal monitor (NPM) detector constructed at the University of Massachusetts Lowell. NPM detectors are deployed at all United States border crossings and shipping ports to stop the illicit transfer of weapons-grade plutonium (WGPu) into our country. This large prototype detector with its 0.93 square meter face area is based on thermal neutron capture in 6Li as an alternate technology to the current, very expensive, 3He-based NPM. A neutron detection efficiency of 27.5 % is measured with a 252Cf source which has a spontaneous fission neutron spectrum very similar to that of 240Pu in WGPu. Measurements with an intense 137Cs source establish the extreme insensitivity of the prototype NPM to gamma-ray backgrounds with only one additional count registered for 1.1 million incident gamma rays. This detector also has the ability to locate neutron sources to within an angle of a few degrees. Its sensitivity is further demonstrated by discovering in a few-second measurement the presence of a 2 curie PuBe neutron source even at a distance of 95.5 feet. This thesis also covers in considerable detail the design features that give rise to both a high intrinsic neutron detection efficiency and an extreme gamma-ray insensitivity.

Development of a thin scintillation films fission-fragment detector and a novel neutron source

DOE PAGES

Rusev, Gencho Yordanov; Jandel, Marian; Baramsai, Bayarbadrakh; ...

2015-08-26

Here, investigation of prompt fission and neutron-capture Υ rays from fissile actinide samples at the Detector for Advanced Neutron Capture Experiments (DANCE) requires use of a fission-fragment detector to provide a trigger or a veto signal. A fission-fragment detector based on thin scintillating films and silicon photomultipliers has been built to serve as a trigger/veto detector in neutron-induced fission measurements at DANCE. The fissile material is surrounded by scintillating films providing a 4π detection of the fission fragments. The scintillations were registered with silicon photomultipliers. A measurement of the 235U(n,f) reaction with this detector at DANCE revealed a correct time-of-flightmore » spectrum and provided an estimate for the efficiency of the prototype detector of 11.6(7)%. Design and test measurements with the detector are described. A neutron source with fast timing has been built to help with detector-response measurements. The source is based on the neutron emission from the spontaneous fission of 252Cf and the same type of scintillating films and silicon photomultipliers. Overall time resolution of the source is 0.3 ns. Design of the source and test measurements with it are described. An example application of the source for determining the neutron/gamma pulse-shape discrimination by a stilbene crystal is given.« less

Reflection Asymmetric Shapes in the Neutron-Rich 140,143Ba Isotopes

NASA Astrophysics Data System (ADS)

Zhu Sheng-jiang (S, J. Zhu; Wang, Mu-ge; J, H. Hamilton; A, V. Ramayya; B, R. S. Babu; W, C. Ma; Long, Gui-lu; Deng, Jing-kang; Zhu, Ling-yan; Li, Ming; T, N. Ginter; J, Komicki; J, D. Cole; R, Aryaeinejad; Y, K. Dardenne; M, W. Drigert; J, O. Rasmussen; Ts, Yu Oganessian; M, A. Stoyer; S, Y. Chu; K, E. Gregorich; M, F. Mohar; S, G. Prussin; I, Y. Lee; N, R. Johnson; F, K. McGowan

1997-08-01

Level schemes for the neutron-rich 140,143Ba nuclei have been determined by study of prompt γ-rays in spontaneous fission of 252Cf. The level pattern and enhanced E1 transitions between π = + and π = - bands show reflection asymmetric shapes with simplex quantum number s = +1 in 140Ba and s = ±i in 143Ba, respectively. The octupole deformation stability with spin variation has been discussed.

Respiratory viruses in healthy infants and infants with cystic fibrosis: a prospective cohort study.

PubMed

Korten, Insa; Kieninger, Elisabeth; Klenja, Shkipe; Mack, Ines; Schläpfer, Njima; Barbani, Maria Teresa; Regamey, Nicolas; Kuehni, Claudia E; Hilty, Markus; Frey, Urs; Gorgievski, Meri; Casaulta, Carmen; Latzin, Philipp

2018-01-01

Acute viral respiratory tract infections in children with cystic fibrosis (CF) are known causes of disease exacerbation. The role of viral infections during infancy is, however, less known, although early infancy is thought to be a crucial period for CF disease development.We prospectively assessed symptomatic and asymptomatic viral detection in the first year of life in infants with CF and healthy controls. In a prospective cohort study, we included 31 infants with CF from the Swiss Cystic Fibrosis Infant Lung Development Cohort and 32 unselected, healthy infants from the Basel Bern Infant Lung Development Cohort and followed them throughout the first year of life. Respiratory symptoms were assessed by weekly telephone interviews. Biweekly nasal swabs were analysed for 10 different viruses and two atypical bacteria with real-time seven duplex PCR (CF=561, controls=712). Infants with CF and healthy controls showed similar numbers of swabs positive for virus (mean 42% vs 44%; OR 0.91, 95% CI 0.66 to 1.26, p=0.6). Virus-positive swabs were less often accompanied by respiratory symptoms in infants with CF (17% vs 23%; OR 0.64, 95% CI 0.43 to 0.95, p=0.026). This finding was pronounced for symptomatic human rhinovirus detection (7% vs 11%; OR 0.52, 95% CI 0.31 to 0.9, p=0.02). Viral detection is not more frequent in infants with CF and respiratory symptoms during viral detection occur even less often than in healthy controls. It is likely an interplay of different factors such as local epithelial properties and immunological mechanisms that contribute to our findings. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Genetic association of pro-inflammatory cytokine gene polymorphisms with coronary artery disease (CAD) in a North Indian population.

PubMed

Mastana, Sarabjit; Prakash, Swayam; Akam, Elizabeth C; Kirby, Melissa; Lindley, Martin R; Sinha, Nakul; Agrawal, Suraksha

2017-09-10

Cytokines regulate the expression of inflammatory molecules which destabilize the atheromatic plaques. This study focuses on studying the association of inflammatory cytokine polymorphisms like TNF-α -308 (G/A), TNF-β +252 (A/G), IL-6 -174 (G/C) and IL-6 -597 (G/A), and IFN-ɣ +874 (T/A) with coronary artery disease (CAD) among north Indian patients. 143 CAD and 137 normal healthy controls were recruited in this study. DNA extraction was carried out by high salting out method. TNF-α -308 (G/A) (rs1800797), TNF-β +252 (A/G) (rs909253), IL-6 -174 (G/C) (rs1800795), IL6 -597 (G/A) (rs1800797), and IFN-ɣ +874 (T/A) (rs2430561) SNPs were genotyped by TaqMan®SNP genotyping assays. Different statistical analyses were performed using SPSS v 22.0 and SNPStats. p≤0.05 was considered significant. Significant risk association with CAD was found for TNF-α -308 (G/A) "A" allele (OR=5.6, CI 1.8-17.4, p=0.001) and TNF-β +252 (A/G) "G" allele (OR=3.4, CI=1.9-6.0, p<0.001). However, no statistical significance was found for IL-6 -174 (G/C) or IL6 -597 (G/A), with CAD. TNF-α -308 (G/A), and TNF-β +252 (A/G) haplotype "GG" "AG" increased CAD risk significantly (GG haplotype, adjusted OR=2.6, CI 1.4-5.0, p=0.003 and AG haplotype OR=8.5, CI 2.2-33.35, p=0.002) after adjustments for age, sex, TC, TG, HDL, APOB, smoking and diet. The present study found significant risk association for TNF-α -308 (G/A), and TNF-β +252 (A/G) genotypes, alleles and haplotypes, with CAD in a North Indian population. Copyright © 2017 Elsevier B.V. All rights reserved.

The effect of iron-fortified complementary food and intermittent preventive treatment of malaria on anaemia in 12- to 36-month-old children: a cluster-randomised controlled trial.

PubMed

Glinz, Dominik; Hurrell, Richard F; Ouattara, Mamadou; Zimmermann, Michael B; Brittenham, Gary M; Adiossan, Lukas G; Righetti, Aurélie A; Seifert, Burkhardt; Diakité, Victorine G; Utzinger, Jürg; N'Goran, Eliézer K; Wegmüller, Rita

2015-09-17

Iron deficiency (ID) and malaria co-exist in tropical regions and both contribute to high rates of anaemia in young children. It is unclear whether iron fortification combined with intermittent preventive treatment (IPT) of malaria would be an efficacious strategy for reducing anaemia in young children. A 9-month cluster-randomised, single-blinded, placebo-controlled intervention trial was carried out in children aged 12-36 months in south-central Côte d'Ivoire, an area of intense and perennial malaria transmission. The study groups were: group 1: normal diet and IPT-placebo (n = 125); group 2: consumption of porridge, an iron-fortified complementary food (CF) with optimised composition providing 2 mg iron as NaFeEDTA and 3.8 mg iron as ferrous fumarate 6 days per week (CF-FeFum) and IPT-placebo (n = 126); group 3: IPT of malaria at 3-month intervals, using sulfadoxine-pyrimethamine and amodiaquine and no dietary intervention (n = 127); group 4: both CF-FeFum and IPT (n = 124); and group 5: consumption of porridge, an iron-fortified CF with the composition currently on the Ivorian market providing 2 mg iron as NaFeEDTA and 3.8 mg iron as ferric pyrophosphate 6 days per week (CF-FePP) and IPT-placebo (n = 127). The primary outcome was haemoglobin (Hb) concentration. Linear and logistic regression mixed-effect models were used for the comparison of the five study groups, and a 2 × 2 factorial analysis was used to assess treatment interactions of CF-FeFum and IPT (study groups 1-4). After 9 months, the Hb concentration increased in all groups to a similar extent with no statistically significant difference between groups. In the 2 × 2 factorial analysis after 9 months, no treatment interaction was found on Hb (P = 0.89). The adjusted differences in Hb were 0.24 g/dl (95 % CI -0.10 to 0.59; P = 0.16) in children receiving IPT and -0.08 g/dl (95 % CI -0.42 to 0.26; P = 0.65) in children receiving CF-FeFum. At baseline, anaemia (Hb <11.0 g/dl) was 82.1 %. After 9 months, IPT decreased the odds of anaemia (odds ratio [OR], 0.46 [95 % CI 0.23-0.91]; P = 0.023), whereas iron-fortified CF did not (OR, 0.85 [95 % CI 0.43-1.68]; P = 0.68), although ID (plasma ferritin <30 μg/l) was decreased markedly in children receiving iron fortified CF (OR, 0.19 [95 % CI 0.09-0.40]; P < 0.001). IPT alone only modestly decreased anaemia, but neither IPT nor iron fortified CF significantly improved Hb concentration after 9 months. Additionally, IPT did not augment the effect of the iron fortified CF. CF fortified with highly bioavailable iron improved iron status but not Hb concentration, despite three-monthly IPT of malaria. Thus, further research is necessary to develop effective combination strategies to prevent and treat anaemia in malaria endemic regions. http://www.clinicaltrials.gov ; identifier NCT01634945; registered on July 3, 2012.

Requirements UML Tool (RUT) Expanded for Extreme Programming (CI02)

NASA Technical Reports Server (NTRS)

McCoy, James R.

2003-01-01

A procedure for capturing and managing system requirements that incorporates XP user stories. Because costs associated with identifying problems in requirements increase dramatically over the lifecycle of a project, a method for identifying sources of software risks in user stories is urgently needed. This initiative aims to determine a set of guide-lines for user stories that will result in high-quality requirement. To further this initiative, a tool is needed to analyze user stories that can assess the quality of individual user stories, detect sources cf software risk's, produce software metrics, and identify areas in user stories that can be improved.

Prognosis of acute coronary events is worse in patients living alone: the FINAMI myocardial infarction register.

PubMed

Lammintausta, Aino; Airaksinen, Juhani K E; Immonen-Räihä, Pirjo; Torppa, Jorma; Kesäniemi, Antero Y; Ketonen, Matti; Koukkunen, Heli; Kärjä-Koskenkari, Päivi; Lehto, Seppo; Salomaa, Veikko

2014-08-01

Single living has been associated with a worse prognosis of acute coronary syndrome (ACS). We aimed to study the relation of sociodemographic characteristics to the morbidity, mortality, and case fatality (CF) of ACS in a large population-based ACS register. The population-based FINAMI myocardial infarction register recorded 15,330 cases of ACS among persons aged 35-99 years in Finland in 1993-2002. Record linkage with the files of Statistics Finland provided information on sociodemographic characteristics (marital status, household size). ACS incidence and 28-day mortality rate were higher in unmarried men and women in all age groups. The prehospital CF of incident ACS was higher in single living and/or unmarried 35-64-year-old people. The 28-day CF was 26% (95% confidence interval, CI, 24-29%) in married men, 42% (95% CI 37-47%) in men who had previously been married, and 51% (95% CI 46-57%) in never-married men. Among women, the corresponding figures were 20% (95% CI 15-24%), 32% (95% CI 25-39%), and 43% (95% CI 31-56%). Most of these CF differences were apparent already at the prehospital phase. The only difference in treatment was that middle-aged men living alone or unmarried received thrombolysis less often. The disparities in ACS morbidity and mortality by marital status tended to widen during the study period. Single living and/or being unmarried increases the risk of having a heart attack and worsens its prognosis both in men and women regardless of age. Most of the excess mortality appears already before the hospital admission and seems not to be related to differences in treatment of ACS. © The European Society of Cardiology 2013 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.

Respiratory syncytial virus prophylaxis in cystic fibrosis: the Canadian registry of palivizumab data (2005-2016).

PubMed

Mitchell, Ian; Wong, S K; Paes, B; Ruff, M; Bjornson, C; Li, A; Lanctôt, K L

2018-05-04

Respiratory syncytial virus (RSV) may cause severe illness in cystic fibrosis (CF) children, but recommendations vary on prophylaxis. CARESS is a prospective registry of children who received palivizumab in 32 Canadian sites from 2005 to 2016. Demographic data were collected at enrollment and respiratory illness-related events recorded monthly. We reviewed respiratory illness hospitalization (RIH) and RSV hospitalization (RSVH) in CF children aged < 24 months versus those prophylaxed for standard indications (SI; prematurity, chronic lung disease [CLD] and congenital heart disease [CHD]), and complex medical disorders (CM). Of 23,228 children analyzed, 19,452 (83.8%) were SI, 3349 (14.4%) were CM, and 427 (1.8%) were CF. CF children were more likely to be Caucasian, heavier at birth and enrollment, and less likely to have a sibling or live in crowded conditions. CF children were similar to the other groups in daycare attendance, history of atopy, and exposure to smoking. RIH incidences were 4.3% (premature), 13.8% CLD, 11.5% CHD, 11.7% CM, and 6.8% CF. RSVH incidence in CF children was similar to that in the SI and CM groups: 1.1, 1.5, and 2.0% groups respectively. Cox regression analyses showed that compared to CF children, the HRs for RSVH in SI (HR 2.0 95% CI 0.5-8.3, p = 0.3) and CM (HR 2.4, 95% CI 0.6-9.8, p = 0.2) did not differ. CF children are equally at risk for RSVH relative to those prophylaxed for other indications. Pending robust evidence from prospective trials, palivizumab could perhaps be considered in the interim, for young CF patients born early during the RSV season with evidence of serious lung disease.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Miller, C A; Clarke, S D; Pozzi, S A

Purpose: To develop an instrument for measuring neutron and photon dose rates from mixed fields with a single device. Methods: Stilbene organic scintillators can be used to detect fast neutrons and photons. Stilbene was used to measure emission from mixed particle sources californium-252 (Cf-252) and plutonium-beryllium (PuBe). Many source detector configurations were used, along with varying amounts of shielding. Collected spectra were analyzed using pulse shape discrimination software, to separate neutron and photon interactions. With a measured light output to energy relationship the pulse height spectrum was converted to energy deposited in the detector. Energy deposited was converted to dosemore » with a variety of standard dose factors, for comparison to current methods. For validation, all measurements and processing was repeated using an EJ-309 liquid scintillator detector. Dose rates were also measured in the same configuration with commercially available dose meters for further validation. Results: Measurements of dose rates will show agreement across all methods. Higher accuracy of pulse shape discrimination at lower energies with stilbene leads to more accurate measurement of neutron and photon deposited dose. In strong fields of mixed particles discrimination can be performed well at a very low energy threshold. This shows accurate dose measurements over a large range of incident particle energy. Conclusion: Stilbene shows promise as a material for dose rate measurements due to its strong ability for separating neutrons and photon pulses and agreement with current methods. A dual particle dose meter would simplify methods which are currently limited to the measurement of only one particle type. Future work will investigate the use of a silicon photomultiplier to reduce the size and required voltage of the assembly, for practical use as a handheld survey meter, room monitor, or phantom installation. Funding From the United States Department of Energy and the National Nuclear Security Administration.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Milbrandt, Anelia; Booth, Samuel

Carbon fiber (CF), known also as graphite fiber, is a lightweight, strong, and flexible material used in both structural (load-bearing) and non-structural applications (e.g., thermal insulation). The high cost of precursors (the starting material used to make CF, which comes predominately from fossil sources) and manufacturing have kept CF a niche market with applications limited mostly to high-performance structural materials (e.g., aerospace). Alternative precursors to reduce CF cost and dependence on fossil sources have been investigated over the years, including biomass-derived precursors such as rayon, lignin, glycerol, and lignocellulosic sugars. The purpose of this study is to provide a comprehensivemore » overview of CF precursors from biomass and their market potential. We examine the potential CF production from these precursors, the state of technology and applications, and the production cost (when data are available). We discuss their advantages and limitations. We also discuss the physical properties of biomass-based CF, and we compare them to those of polyacrylonitrile (PAN)-based CF. We also discuss manufacturing and end-product considerations for bio-based CF, as well as considerations for plant siting and biomass feedstock logistics, feedstock competition, and risk mitigation strategies. The main contribution of this study is that it provides detailed technical and market information about each bio-based CF precursor in one document while other studies focus on one precursor at a time or a particular topic (e.g., processing). Thus, this publication allows for a comprehensive view of the CF potential from all biomass sources and serves as a reference for both novice and experienced professionals interested in CF production from alternative sources.« less

The prognostic value of KRAS mutation by cell-free DNA in cancer patients: A systematic review and meta-analysis.

PubMed

Zhuang, Rongyuan; Li, Song; Li, Qian; Guo, Xi; Shen, Feng; Sun, Hong; Liu, Tianshu

2017-01-01

KRAS mutation has been found in various types of cancer. However, the prognostic value of KRAS mutation in cell-free DNA (cfDNA) in cancer patients was conflicting. In the present study, a meta-analysis was conducted to clarify its prognostic significance. Literature searches of Cochrane Library, EMBASE, PubMed and Web of Science were performed to identify studies related to KRAS mutation detected by cfDNA and survival in cancer patients. Two evaluators reviewed and extracted the information independently. Review Manager 5.3 software was used to perform the statistical analysis. Thirty studies were included in the present meta-analysis. Our analysis showed that KRAS mutation in cfDNA was associated with a poorer survival in cancer patients for overall survival (OS, HR 2.02, 95% CI 1.63-2.51, P<0.01) and progression-free survival (PFS, HR 1.64, 95% CI 1.27-2.13, P<0.01). In subgroup analyses, KRAS mutation in pancreatic cancer, colorectal cancer, non-small cell lung cancer and ovarian epithelial cancer had HRs of 2.81 (95% CI 1.83-4.30, P<0.01), 1.67 (95% CI 1.25-2.42, P<0.01), 1.64 (95% CI 1.13-2.39, P = 0.01) and 2.17 (95% 1.12-4.21, p = 0.02) for OS, respectively. In addition, the ethnicity didn't influence the prognostic value of KRAS mutation in cfDNA in cancer patients (p = 0.39). Prognostic value of KRAS mutation was slightly higher in plasma than in serum (HR 2.13 vs 1.65), but no difference was observed (p = 0.37). Briefly, KRAS mutation in cfDNA was a survival prognostic biomarker in cancer patients. Its prognostic value was different in various types of cancer.

Prevention of exacerbations in patients with stable non-cystic fibrosis bronchiectasis: a systematic review and meta-analysis of pharmacological and non-pharmacological therapies.

PubMed

Abu Dabrh, Abd Moain; Hill, Adam T; Dobler, Claudia C; Asi, Noor; Farah, Wigdan H; Haydour, Qusay; Wang, Zhen; Benkhadra, Khalid; Prokop, Larry J; Murad, Mohammad Hassan

2018-04-20

Several pharmacological and non-pharmacological therapies are used to treat stable bronchiectasis of non-cystic fibrosis (CF) aetiology. We conducted a systematic review and meta-analysis to assess the evidence of the effectiveness of pharmacological and non-pharmacological treatment options in patients with stable non-CF bronchiectasis with a focus on reducing exacerbations. Multiple databases were searched through September 2017. Outcomes included the number of patients with exacerbation events, mean number of exacerbations, hospitalisations, mortality, quality of life measures, and safety and adverse effects. Meta-analysis was conducted using the random effects model. 30 randomised controlled trials enrolled subjects with non-CF bronchiectasis using different interventions. Moderate-quality evidence supported the effect of long-term antibiotics (≥3 months) on lowering the number of patients experiencing exacerbation events (relative risk 0.77 (95% CI 0.68 to 0.89)), reducing number of exacerbations (incidence rate ratio 0.62 (95% CI 0.49 to 0.78)), improving forced expiratory volume (litre) in the first second (FEV 1 ) (weighted mean difference (WMD); 0.02 (95% CI 0.00 to 0.04)), decreasing sputum purulence scores (numerical scale of 1-8) (WMD -0.90 (95% CI -1.58 to -0.22)) and improving quality of life scores assessed by the St George's Respiratory Questionnaire (WMD -6.07 (95% CI -10.7 to -1.43)). Bronchospasm increased with inhaled antibiotics while diarrhoea increased particularly with oral macrolide therapy. Moderate-quality evidence supports long-term antibiotic therapy for preventing exacerbations in stable non-CF bronchiectasis. However, data about the optimum agent, mode of therapy and length of treatment are limited. There is paucity of high-quality evidence to support the management of stable non-CF bronchiectasis including prevention of exacerbations. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Routine Angiographic Follow-Up versus Clinical Follow-Up after Percutaneous Coronary Intervention in Acute Myocardial Infarction

PubMed Central

Kim, Yong Hoon; Her, Ae-Young; Choi, Byoung Geol; Shim, Minsuk; Choi, Se Yeon; Byun, Jae Kyeong; Li, Hu; Kim, Woohyeun; Kang, Jun Hyuk; Choi, Jah Yeon; Park, Eun Jin; Park, Sung Hun; Lee, Sunki; Na, Jin Oh; Choi, Cheol Ung; Lim, Hong Euy; Kim, Eung Ju; Park, Chang Gyu; Seo, Hong Seog; Oh, Dong Joo

2017-01-01

Purpose Differences in the utility of routine angiographic follow-up (RAF) and clinical follow-up (CF) after percutaneous coronary intervention (PCI) in acute myocardial infarction (AMI) are not well understood. The present study aimed to compare the 3-year clinical outcomes of RAF and CF in AMI patients who underwent PCI with drug-eluting stents (DES). Materials and Methods A total of 774 consecutive AMI patients who underwent PCI with DES were enrolled. RAF was performed at 6 to 9 months after index PCI (n=425). The remaining patients were medically managed and clinically followed (n=349); symptom-driven events were captured. To adjust for any potential confounders, a propensity score matched analysis was performed using a logistic regression model, and two propensity-matched groups (248 pairs, n=496, C-statistic=0.739) were generated. Cumulative clinical outcomes up to 3 years were compared between RAF and CF groups. Results During the 3-year follow-up period, the cumulative incidences of revascularization [target lesion revascularization: hazard ratio (HR), 2.40; 95% confidence interval (CI), 1.18–4.85; p=0.015, target vessel revascularization (TVR): HR, 3.33; 95% CI, 1.69–6.58; p=0.001, non-TVR: HR, 5.64; 95% CI, 1.90–16.6; p=0.002] and major adverse cardiac events (MACE; HR, 3.32; 95% CI, 1.92–5.73; p<0.001) were significantly higher in the RAF group than the CF group. However, the 3-year incidences of death and myocardial infarction were not different between the two groups. Conclusion RAF following index PCI with DES in AMI patients was associated with increased incidences of revascularization and MACE. Therefore, CF seems warranted for asymptomatic patients after PCI for AMI. PMID:28540983

Risk factors for persistent Aspergillus respiratory isolation in cystic fibrosis.

PubMed

Hong, Gina; Psoter, Kevin J; Jennings, Mark T; Merlo, Christian A; Boyle, Michael P; Hadjiliadis, Denis; Kawut, Steven M; Lechtzin, Noah

2018-02-12

Aspergillus species are increasingly detected in the respiratory tracts of individuals with cystic fibrosis (CF), and chronic Aspergillus fumigatus is associated with more frequent hospitalizations for pulmonary exacerbations. However, patient and clinical factors that may contribute to the acquisition of persistent Aspergillus infection have yet to be identified. The objective of this study was to identify risk factors for development of Aspergillus respiratory isolation in CF. A retrospective cohort study of participants in the CF Foundation Patient Registry between 2006 and 2012 was conducted. Generalized estimating equation models were used to evaluate the association between the development of persistent Aspergillus respiratory isolation and individual level demographic and clinical characteristics. Among 16,095 individuals with CF followed from 2006 to 2012, 1541 (9.6%) subjects developed persistent Aspergillus isolation. White race (Odds Ratio [OR] 1.74, 95% confidence interval 1.23, 2.48, p<0.001) and pancreatic insufficiency (OR 1.50, 95% CI 1.09, 2.06, p<0.001) were found to be risk factors for persistent Aspergillus isolation. Chronic therapies, including inhaled antibiotics (OR 1.33; 95% CI 1.21, 1.46), macrolides (OR 1.23, 95% CI 1.14, 1.32, p<0.001), and inhaled corticosteroids (OR 1.13, 95% CI 1.04, 1.20, p<0.001) were also independently associated with an increased risk for persistent Aspergillus isolation. We identified macrolides and inhaled antibiotics, which individually have been shown to improve CF outcomes, and inhaled corticosteroids as risk factors for developing persistent Aspergillus isolation. Further work is needed to determine whether these associations are causal or due to confounding by other factors. Copyright © 2018 European Cystic Fibrosis Society. Published by Elsevier B.V. All rights reserved.

A portable neutron spectroscope (NSPECT) for detection, imaging and identification of nuclear material

NASA Astrophysics Data System (ADS)

Ryan, James M.; Bancroft, Christopher; Bloser, Peter; Bravar, Ulisse; Fourguette, Dominique; Frost, Colin; Larocque, Liane; McConnell, Mark L.; Legere, Jason; Pavlich, Jane; Ritter, Greg; Wassick, Greg; Wood, Joshua; Woolf, Richard

2010-08-01

We have developed, fabricated and tested a prototype imaging neutron spectrometer designed for real-time neutron source location and identification. Real-time detection and identification is important for locating materials. These materials, specifically uranium and transuranics, emit neutrons via spontaneous or induced fission. Unlike other forms of radiation (e.g. gamma rays), penetrating neutron emission is very uncommon. The instrument detects these neutrons, constructs images of the emission pattern, and reports the neutron spectrum. The device will be useful for security and proliferation deterrence, as well as for nuclear waste characterization and monitoring. The instrument is optimized for imaging and spectroscopy in the 1-20 MeV range. The detection principle is based upon multiple elastic neutron-proton scatters in organic scintillator. Two detector panel layers are utilized. By measuring the recoil proton and scattered neutron locations and energies, the direction and energy spectrum of the incident neutrons can be determined and discrete and extended sources identified. Event reconstruction yields an image of the source and its location. The hardware is low power, low mass, and rugged. Its modular design allows the user to combine multiple units for increased sensitivity. We will report the results of laboratory testing of the instrument, including exposure to a calibrated Cf-252 source. Instrument parameters include energy and angular resolution, gamma rejection, minimum source identification distances and times, and projected effective area for a fully populated instrument.

Epidemiology of nontuberculous mycobacteria (NTM) amongst individuals with cystic fibrosis (CF).

PubMed

Viviani, Laura; Harrison, Michael J; Zolin, Anna; Haworth, Charles S; Floto, R Andres

2016-09-01

Infection by nontuberculous mycobacteria (NTM) in patients with cystic fibrosis (CF) is often associated with significant morbidity. Limited, conflicting results are published regarding risk factors for pulmonary NTM disease. We analysed factors potentially associated with NTM in a large population of European patients with CF. We investigated associations between presence of NTM and various factors for patients registered in the European Cystic Fibrosis Society Patient Registry. 374 (2.75%) of 13,593 patients studied had at least one positive NTM culture within the study year. Age- and FEV1-adjusted odds of NTM infection was more than 2.5 times higher (95%CI: 1.79; 3.60) in patients infected by Stenotrophomonas maltophilia than in patients not infected (p<0.0001), 2.36 times higher (95%CI: 1.80;3.08) in patients with ABPA than without (p<0.0001), 1.79 times higher (95%CI: 1.34; 2.38) in patients who use bronchodilators than in patients who don't (p<0.0001), 1.49 times higher (95%CI: 1.18; 1.89) in patients who use inhaled antibiotics than in patients who don't (p=0.001), and 1.30 times higher (95%CI: 1.02; 1.66) in patients who use rhDNase than in patients who don't (p=0.032). NTM-positive cultures in individuals with CF are associated with distinct clinical variables. Improved data collection identifying risk factors for NTM infection will allow more focused screening strategies, and influence therapeutic choices and infection control measures in high-risk patients. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

New band structures in Neutron-Rich Mo and Ru Isotopes

DOE PAGES

Hamilton, J. H.; Luoa, Y. X.; Zhu, S. J.; ...

2009-01-01

Rotational bands in 110,112Ru and 108Mo have been investigated by means of γ-γ-γ and γ-γ(θ) coincidences of prompt γ rays emitted in the spontaneous fission of 252Cf. New ΔI = 1 negative parity doublet bands are found. These bands in 110,112Ru and 108Mo have all the properties expected for chiral vibrations. Microscopic calculations that combine the TAC meanfield with random phase approximation support this interpretation.

Piezonuclear battery

DOEpatents

Bongianni, Wayne L.

1992-01-01

A piezonuclear battery generates output power arising from the piezoelectric voltage produced from radioactive decay particles interacting with a piezoelectric medium. Radioactive particle energy may directly create an acoustic wave in the piezoelectric medium or a moderator may be used to generate collision particles for interacting with the medium. In one embodiment a radioactive material (.sup.252 Cf) with an output of about 1 microwatt produced a 12 nanowatt output (1.2% conversion efficiency) from a piezoelectric copolymer of vinylidene fluoride/trifluorethylene.

Chronic Mycobacterium abscessus infection and lung function decline in cystic fibrosis.

PubMed

Esther, Charles R; Esserman, Denise A; Gilligan, Peter; Kerr, Alan; Noone, Peadar G

2010-03-01

Although nontuberculous mycobacteria (NTM) are recognized pathogens in cystic fibrosis (CF), associations with clinical outcomes remain unclear. Microbiological data was obtained from 1216 CF patients over 8years (481+/-55patients/year). Relationships to clinical outcomes were examined in the subset (n=271, 203+/-23 patients/year) with longitudinal data. Five hundred thirty-six of 4862 (11%) acid-fast bacilli (AFB) cultures grew NTM, with Mycobacterium abscessus (n=298, 55.6%) and Mycobacterium avium complex (n=190, 35.4%) most common. Associated bacterial cultures grew Stenotrophomonas or Aspergillus species more often when NTM were isolated (18.2% vs. 8.4% and 13.9% vs. 7.2%, respectively, p<0.01). After controlling for confounders, patients with chronic M. abscessus infection had greater rates of lung function decline than those with no NTM infection (-2.52 vs. -1.64% predicted FEV(1)/year, p<0.05). NTM infection is common in CF and associated with particular pathogens. Chronic M. abscessus infection is associated with increased lung function decline. Copyright (c) 2009 European Cystic Fibrosis Society. Published by Elsevier B.V. All rights reserved.

Optimization and Characterization of a Novel Self Powered Solid State Neutron Detector

NASA Astrophysics Data System (ADS)

Clinton, Justin

There is a strong interest in detecting both the diversion of special nuclear material (SNM) from legitimate, peaceful purposes and the transport of illicit SNM across domestic and international borders and ports. A simple solid-state detector employs a planar solar-cell type p-n junction and a thin conversion layer that converts incident neutrons into detectable charged particles, such as protons, alpha-particles, and heavier ions. Although simple planar devices can act as highly portable, low cost detectors, they have historically been limited to relatively low detection efficiencies; ˜10% and ˜0.2% for thermal and fast detectors, respectively. To increase intrinsic detection efficiency, the incorporation of 3D microstructures into p-i-n silicon devices was proposed. In this research, a combination of existing and new types of detector microstructures were investigated; Monte Carlo models, based on analytical calculations, were constructed and characterized using the GEANT4 simulation toolkit. The simulation output revealed that an array of etched hexagonal holes arranged in a honeycomb pattern and filled with either enriched (99% 10B) boron or parylene resulted in the highest intrinsic detection efficiencies of 48% and 0.88% for thermal and fast neutrons, respectively. The optimal parameters corresponding to each model were utilized as the basis for the fabrication of several prototype detectors. A calibrated 252Cf spontaneous fission source was utilized to generate fast neutrons, while thermal neutrons were created by placing the 252Cf in an HDPE housing designed and optimized using the MCNP simulation software. Upon construction, thermal neutron calibration was performed via activation analysis of gold foils and measurements from a 6Li loaded glass scintillator. Experimental testing of the prototype detectors resulted in maximum intrinsic efficiencies of 4.5 and 0.12% for the thermal and fast devices, respectively. The prototype thermal device was filled with natural (19% 10B) boron; scaling the response to 99% 10B enriched boron resulted in an intrinsic efficiency of 22.5%, one of the highest results in the literature. A comparison of simulated and experimental detector responses demonstrated a high degree of correlation, validating the conceptual models.

A study of intrinsic statistical variation for low-energy nuclear recoils in liquid xenon detector for dark matter searches

NASA Astrophysics Data System (ADS)

Wang, Lu; Wei, Wenzhao; Mei, Dongming; Cubed Collaboration

2015-10-01

Noble liquid xenon experiments, such as XENON100, LUX, XENON 1-Ton, and LZ are large dark matter experiments directly searches for weakly interacting massive particles (WIMPs). One of the most important features is to discriminate nuclear recoils from electronic recoils. Detector response is generally calibrated with different radioactive sources including 83mKr, tritiated methane, 241AmBe, 252Cf, and DD-neutrons. The electronic recoil and nuclear recoil bands have been determined by these calibrations. However, the width of nuclear recoil band needs to be fully understood. We derive a theoretical model to understand the correlation of the width of nuclear recoil band and intrinsic statistical variation. In addition, we conduct experiments to validate the theoretical model. In this paper, we present the study of intrinsic statistical variation contributing to the width of nuclear recoil band. DE-FG02-10ER46709 and the state of South Dakota.

Development of a lithium fluoride zinc sulfide based neutron multiplicity counter

NASA Astrophysics Data System (ADS)

Cowles, Christian; Behling, Spencer; Baldez, Phoenix; Folsom, Micah; Kouzes, Richard; Kukharev, Vladislav; Lintereur, Azaree; Robinson, Sean; Siciliano, Edward; Stave, Sean; Valdez, Patrick

2018-04-01

The feasibility of a full-scale lithium fluoride zinc sulfide (LiF/ZnS) based neutron multiplicity counter has been demonstrated. The counter was constructed of modular neutron detecting stacks that each contain five sheets of LiF/ZnS interleaved between six sheets of wavelength shifting plastic with a photomultiplier tube on each end. Twelve such detector stacks were placed around a sample chamber in a square arrangement with lithiated high-density polyethylene blocks in the corners to reflect high-energy neutrons and capture low-energy neutrons. The final system design was optimized via modeling and small-scale test. Measuring neutrons from a 252Cf source, the counter achieved a 36% neutron detection efficiency (ɛ) and an 11 . 7 μs neutron die-away time (τ) for a doubles figure-of-merit (ɛ2 / τ) of 109. This is the highest doubles figure-of-merit measured to-date for a 3He-free neutron multiplicity counter.

An evaluation of a manganese bath system having a new geometry through MCNP modelling.

PubMed

Khabaz, Rahim

2012-12-01

In this study, an approximate symmetric cylindrical manganese bath system with equal diameter and height was appraised using a Monte Carlo simulation. For nine sizes of the tank filled with MnSO(4).H(2)O solution of three different concentrations, the necessary correction factors involved in the absolute measurement of neutron emission rate were determined by a detailed modelling of the MCNP4C code with the ENDF/B-VII.0 neutron cross section data library. The results obtained were also used to determine the optimum dimensions of the bath for each concentration of solution in the calibration of (241)Am-Be and (252)Cf sources. Also, the amount of gamma radiation produced as a result of (n,γ) the reaction with the nuclei of the manganese sulphate solution that escaped from the boundary of each tank was evaluated. This gamma can be important for the background in NaI(Tl) detectors and issues concerned with radiation protection.

Stabilization of Particle Discrimination Efficiencies for Neutron Spectrum Unfolding With Organic Scintillators

NASA Astrophysics Data System (ADS)

Lawrence, Chris C.; Polack, J. K.; Febbraro, Michael; Kolata, J. J.; Flaska, Marek; Pozzi, S. A.; Becchetti, F. D.

2017-02-01

The literature discussing pulse-shape discrimination (PSD) in organic scintillators dates back several decades. However, little has been written about PSD techniques that are optimized for neutron spectrum unfolding. Variation in n-γ misclassification rates and in γ/n ratio of incident fields can distort the neutron pulse-height response of scintillators and these distortions can in turn cause large errors in unfolded spectra. New applications in arms-control verification call for detection of lower-energy neutrons, for which PSD is particularly problematic. In this article, we propose techniques for removing distortions on pulse-height response that result from the merging of PSD distributions in the low-pulse-height region. These techniques take advantage of the repeatable shapes of PSD distributions that are governed by the counting statistics of scintillation-photon populations. We validate the proposed techniques using accelerator-based time-of-flight measurements and then demonstrate them by unfolding the Watt spectrum from measurement with a 252Cf neutron source.

Key metrics for HFIR HEU and LEU models

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ilas, Germina; Betzler, Benjamin R.; Chandler, David

This report compares key metrics for two fuel design models of the High Flux Isotope Reactor (HFIR). The first model represents the highly enriched uranium (HEU) fuel currently in use at HFIR, and the second model considers a low-enriched uranium (LEU) interim design fuel. Except for the fuel region, the two models are consistent, and both include an experiment loading that is representative of HFIR's current operation. The considered key metrics are the neutron flux at the cold source moderator vessel, the mass of 252Cf produced in the flux trap target region as function of cycle time, the fast neutronmore » flux at locations of interest for material irradiation experiments, and the reactor cycle length. These key metrics are a small subset of the overall HFIR performance and safety metrics. They were defined as a means of capturing data essential for HFIR's primary missions, for use in optimization studies assessing the impact of HFIR's conversion from HEU fuel to different types of LEU fuel designs.« less

NIST Calibration of a Neutron Spectrometer ROSPEC.

PubMed

Heimbach, Craig

2006-01-01

A neutron spectrometer was acquired for use in the measurement of National Institute of Standards and Technology neutron fields. The spectrometer included options for the measurement of low and high energy neutrons, for a total measurement range from 0.01 eV up to 17 MeV. The spectrometer was evaluated in calibration fields and was used to determine the neutron spectrum of an Americium-Beryllium neutron source. The calibration fields used included bare and moderated (252)Cf, monoenergetic neutron fields of 2.5 MeV and 14 MeV, and a thermal-neutron beam. Using the calibration values determined in this exercise, the spectrometer gives a good approximation of the neutron spectrum, and excellent values for neutron fluence, for all NIST calibration fields. The spectrometer also measured an Americium-Beryllium neutron field in a NIST exposure facility and determined the field quite well. The spectrometer measured scattering effects in neutron spectra which previously could be determined only by calculation or integral measurements.

CHARACTERIZATION OF A THIN SILICON SENSOR FOR ACTIVE NEUTRON PERSONAL DOSEMETERS.

PubMed

Takada, M; Nunomiya, T; Nakamura, T; Matsumoto, T; Masuda, A

2016-09-01

A thin silicon sensor has been developed for active neutron personal dosemeters for use by aircrews and first responders. This thin silicon sensor is not affected by the funneling effect, which causes detection of cosmic protons and over-response to cosmic neutrons. There are several advantages to the thin silicon sensor: a decrease in sensitivity to gamma rays, an improvement of the energy detection limit for neutrons down to 0.8 MeV and an increase in the sensitivity to fast neutrons. Neutron response functions were experimentally obtained using 2.5 and 5 MeV monoenergy neutron beams and a (252)Cf neutron source. Simulation results using the Monte Carlo N-Particle transport code agree quite well with the experimental ones when an energy deposition region shaped like a circular truncated cone is used in place of a cylindrical region. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

40 CFR 61.252 - Standard.

Code of Federal Regulations, 2010 CFR

2010-07-01

... uranium mill tailings pile shall not exceed 20 pCi/(m2-sec) (1.9 pCi/(ft2-sec)) of radon-222. (b) After... piles, the exemption for existing piles in 40 CFR 192.32(a) notwithstanding. [54 FR 51703, Dec. 15, 1989...

Nonnegative Tensor Factorization Approach Applied to Fission Chamber’s Output Signals Blind Source Separation

NASA Astrophysics Data System (ADS)

Laassiri, M.; Hamzaoui, E.-M.; Cherkaoui El Moursli, R.

2018-02-01

Inside nuclear reactors, gamma-rays emitted from nuclei together with the neutrons introduce unwanted backgrounds in neutron spectra. For this reason, powerful extraction methods are needed to extract useful neutron signal from recorded mixture and thus to obtain clearer neutron flux spectrum. Actually, several techniques have been developed to discriminate between neutrons and gamma-rays in a mixed radiation field. Most of these techniques, tackle using analogue discrimination methods. Others propose to use some organic scintillators to achieve the discrimination task. Recently, systems based on digital signal processors are commercially available to replace the analog systems. As alternative to these systems, we aim in this work to verify the feasibility of using a Nonnegative Tensor Factorization (NTF) to blind extract neutron component from mixture signals recorded at the output of fission chamber (WL-7657). This last have been simulated through the Geant4 linked to Garfield++ using a 252Cf neutron source. To achieve our objective of obtaining the best possible neutron-gamma discrimination, we have applied the two different NTF algorithms, which have been found to be the best methods that allow us to analyse this kind of nuclear data.

Segmented Ge detector rejection of internal beta activity produced by neutron irradiation

NASA Technical Reports Server (NTRS)

Varnell, L. S.; Callas, J. L.; Mahoney, W. A.; Pehl, R. H.; Landis, D. A.

1991-01-01

Future Ge spectrometers flown in space to observe cosmic gamma-ray sources will incorporate segmented detectors to reduce the background from radioactivity produced by energetic particle reactions. To demonstrate the effectiveness of a segmented Ge detector in rejecting background events due to the beta decay of internal radioactivity, a laboratory experiment has been carried out in which radioactivity was produced in the detector by neutron irradiation. A Cf-252 source of neutrons was used to produce, by neutron capture on Ge-74 (36.5 percent of natural Ge) in the detector itself, Ge-75 (t sub 1/2 = 82.78 min), which decays by beta emission with a maximum electron kinetic energy of 1188 keV. By requiring that an ionizing event deposit energy in two or more of the five segments of the detector, each about 1-cm thick, the beta particles, which have a range of about 1-mm, are rejected, while most external gamma rays incident on the detector are counted. Analysis of this experiment indicates that over 85 percent of the beta events from the decay of Ge-75 are rejected, which is in good agreement with Monte Carlo calculations.

Novel Developments in Organonitrogen Fluorine Chemistry from Carbon- Nitrogen

DTIC Science & Technology

1991-11-21

alkan- imines (R.FC-NBr, P.R CF3. C2 F5, n-C3F7, CF2CI. CCI3). Photolyuis of the perfluorinated N-bromo compounds af- fords the novel perfluoroazines...physical properties. Alternative and improved I syntheses of three compounds are also reported. The perfluorinated N-haloimines, CF 2-NX (X = F, Cl...ihenakaif e anibokn i ls eatv ncephl ndncepii sbTitutionths reactions ead toetdsrutrso a variety of novelrgni compounds . Ofseilitrsoaftedaiiie

Effects of inaccuracies in arterial path length measurement on differences in MRI and tonometry measured pulse wave velocity.

PubMed

Weir-McCall, Jonathan R; Khan, Faisel; Cassidy, Deirdre B; Thakur, Arsh; Summersgill, Jennifer; Matthew, Shona Z; Adams, Fiona; Dove, Fiona; Gandy, Stephen J; Colhoun, Helen M; Belch, Jill Jf; Houston, J Graeme

2017-05-10

Carotid-femoral pulse wave velocity (cf-PWV) and aortic PWV measured using MRI (MRI-PWV) show good correlation, but with a significant and consistent bias across studies. The aim of the current study was to evaluate whether the differences between cf.-PWV and MRI-PWV can be accounted for by inaccuracies of currently used distance measurements. One hundred fourteen study participants were recruited into one of 4 groups: Type 2 diabetes melltus (T2DM) with cardiovascular disease (CVD) (n = 23), T2DM without CVD (n = 41), CVD without T2DM (n = 25) and a control group (n = 25). All participants underwent cf.-PWV, cardiac MRI and whole body MR angiography(WB-MRA). 90 study participants also underwent aortic PWV using MRI. cf.-PWV EXT was performed using a SphygmoCor device (Atcor Medical, West Ryde, Australia). The true intra-arterial pathlength was measured using the WB-MRA and then used to recalculate the cf.-PWV EXT to give a cf.-PWV MRA . Distance measurements were significantly lower on WB-MRA than on external tape measure (mean diff = -85.4 ± 54.0 mm,p < 0.001). MRI-PWV was significantly lower than cf.-PWV EXT (MRI-PWV = 8.1 ± 2.9 vs. cf.-PWV EXT  = 10.9 ± 2.7 ms -1 ,p < 0.001). When cf.-PWV was recalculated using the inter-arterial distance from WB-MRA, this difference was significantly reduced but not lost (MRI-PWV = 8.1 ± 2.9 ms -1 vs. cf.-PWV MRA 9.1 ± 2.1 ms -1 , mean diff = -0.96 ± 2.52 ms -1 ,p = 0.001). Recalculation of the PWV increased correlation with age and pulse pressure. Differences in cf.-PWV and MRI PWV can be predominantly but not entirely explained by inaccuracies introduced by the use of simple surface measurements to represent the convoluted arterial path between the carotid and femoral arteries.

Prospective evaluation of respiratory exacerbations in children with cystic fibrosis from newborn screening to 5 years of age.

PubMed

Byrnes, Catherine Ann; Vidmar, Suzanna; Cheney, Joyce L; Carlin, John B; Armstrong, David S; Cooper, Peter J; Grimwood, Keith; Moodie, Marj; Robertson, Colin F; Rosenfeld, Margaret; Tiddens, Harm A; Wainwright, Claire E

2013-07-01

Newborn screening allows novel treatments for cystic fibrosis (CF) to be trialled in early childhood before irreversible lung injury occurs. As respiratory exacerbations are a potential trial outcome variable, we determined their rate, duration and clinical features in preschool children with CF; and whether they were associated with growth, lung structure and function at age 5 years. Respiratory exacerbations were recorded prospectively in Australasian CF Bronchoalveolar Lavage trial subjects from enrolment after newborn screening to age 5 years, when all participants underwent clinical assessment, chest CT scans and spirometry. 168 children (88 boys) experienced 2080 exacerbations, at an average rate of 3.66 exacerbations per person-year; 80.1% were community managed and 19.9% required hospital admission. There was an average increase in exacerbation rate of 9% (95% CI 4% to 14%; p<0.001) per year of age. Exacerbation rate differed by site (p<0.001) and was 26% lower (95% CI 12% to 38%) in children receiving 12 months of prophylactic antibiotics. The rate of exacerbations in the first 2 years was associated with reduced forced expiratory volume in 1 s z scores. Ever having a hospital-managed exacerbation was associated with bronchiectasis (OR 2.67, 95% CI 1.13 to 6.31) in chest CT scans, and lower weight z scores at 5 years of age (coefficient -0.39, 95% CI -0.74 to -0.05). Respiratory exacerbations in young children are markers for progressive CF lung disease and are potential trial outcome measures for novel treatments in this age group.

Coal home heating and environmental tobacco smoke in relation to lower respiratory illness in Czech children, from birth to 3 years of age

DOE Office of Scientific and Technical Information (OSTI.GOV)

Baker, R.J.; Hert-Picciotto, I.; Dostal, M.

2006-07-15

The objective of this study was to evaluate how indoor pollution from tobacco and home heating may adversely affect respiratory health in young children. A total of 452 children born 1994-1996 in two districts in the Czech Republic participated. Lower respiratory illness (LRI) diagnoses occurred more frequently in children from homes heated by coal (vs. other energy sources or distant furnaces; rate ratio (RR) = 1.45; 95% confidence interval (CI), 1.07-1.97). Maternal prenatal smoking and other adult smokers also increased LRI rates (respectively: RR = 1.48; 95% CI, 1.10-2.01; and RR = 1.29; 95% CI, 1.01-1.65). Cooking fuels (primarily electricity,more » natural gas, or propane) were not associated with LRI incidence. For children never breast-fed, coal home heating and mother's smoking conferred substantially greater risks: RR = 2.77 (95% CI, 1.45-5.27) and RR = 2.52 (95% CI, 1.31-4.85), respectively. This maternal smoking and coal home heating increased risk for LRI in the first 3 years of life, particularly in children not breast-fed.« less

Prospective multicenter German study on pulmonary colonization with Scedosporium /Lomentospora species in cystic fibrosis: Epidemiology and new association factors.

PubMed

Schwarz, Carsten; Brandt, Claudia; Antweiler, Elisabeth; Krannich, Alexander; Staab, Doris; Schmitt-Grohé, Sabina; Fischer, Rainald; Hartl, Dominik; Thronicke, Anja; Tintelnot, Kathrin

2017-01-01

An increasing rate of respiratory colonization and infection in cystic fibrosis (CF) is caused by fungi of the Scedosporium apiospermum species complex or Lomentospora prolificans (Sac-Lp). These fungi rank second among the filamentous fungi colonizing the CF airways, after Aspergillus fumigatus. However, the epidemiology, clinical relevance and risk of pulmonary colonization with Sac-Lp are rarely understood in CF. The objective of the present prospective multicenter study was to study pathogen distribution and determine association factors of pulmonary Sac-Lp colonization in patients with CF. Clinical, microbiological and laboratory data of 161 patients aged 6-59 years with CF in Germany were analyzed for Sac-Lp distribution and association factors. The free statistical software R was utilized to investigate adjusted logistic regression models for association factors. Of the 161 patients included in the study, 74 (56%) were male. The median age of the study cohort was 23 years (interquartile range 13-32 years). 58 patients of the total cohort (36%) were < 18 years old. Adjusted multivariate regression analysis revealed that Sac-Lp colonization was associated with younger age (OR 0.8684, 95%CI: 0.7955-0.9480, p<0.005) and less colonization with H. influenzae (OR 0.0118, 95%CI: 0.0009-0.1585, p<0.001). In addition, Sac-Lp-colonized patients had more often allergic bronchopulmonary aspergillosis (ABPA) (OR 14.6663, 95%CI: 2.1873-98.3403, p<0.01) and have been colonized more often with the mucoid phenotype of Pseudomonas aeruginosa (OR 9.8941, 95%CI: 1.0518-93.0705, p<0.05). Newly found association of ABPA and Pseudomonas revealed new probable risk factors for Sac-Lp colonization. Allergy might play a role in inducing immunologic host reactions which lead to a less effective response to species of Sac-Lp.

Prospective multicenter German study on pulmonary colonization with Scedosporium /Lomentospora species in cystic fibrosis: Epidemiology and new association factors

PubMed Central

Schwarz, Carsten; Brandt, Claudia; Antweiler, Elisabeth; Krannich, Alexander; Staab, Doris; Schmitt-Grohé, Sabina; Fischer, Rainald; Hartl, Dominik

2017-01-01

Background An increasing rate of respiratory colonization and infection in cystic fibrosis (CF) is caused by fungi of the Scedosporium apiospermum species complex or Lomentospora prolificans (Sac-Lp). These fungi rank second among the filamentous fungi colonizing the CF airways, after Aspergillus fumigatus. However, the epidemiology, clinical relevance and risk of pulmonary colonization with Sac-Lp are rarely understood in CF. The objective of the present prospective multicenter study was to study pathogen distribution and determine association factors of pulmonary Sac-Lp colonization in patients with CF. Material and methods Clinical, microbiological and laboratory data of 161 patients aged 6–59 years with CF in Germany were analyzed for Sac-Lp distribution and association factors. The free statistical software R was utilized to investigate adjusted logistic regression models for association factors. Results Of the 161 patients included in the study, 74 (56%) were male. The median age of the study cohort was 23 years (interquartile range 13–32 years). 58 patients of the total cohort (36%) were < 18 years old. Adjusted multivariate regression analysis revealed that Sac-Lp colonization was associated with younger age (OR 0.8684, 95%CI: 0.7955–0.9480, p<0.005) and less colonization with H. influenzae (OR 0.0118, 95%CI: 0.0009–0.1585, p<0.001). In addition, Sac-Lp-colonized patients had more often allergic bronchopulmonary aspergillosis (ABPA) (OR 14.6663, 95%CI: 2.1873–98.3403, p<0.01) and have been colonized more often with the mucoid phenotype of Pseudomonas aeruginosa (OR 9.8941, 95%CI: 1.0518–93.0705, p<0.05). Conclusion Newly found association of ABPA and Pseudomonas revealed new probable risk factors for Sac-Lp colonization. Allergy might play a role in inducing immunologic host reactions which lead to a less effective response to species of Sac-Lp. PMID:28178337

The role of implantable cardioverter defibrillators in patients bridged to transplantation with a continuous-flow left ventricular assist device: A propensity score matched analysis.

PubMed

Clerkin, Kevin J; Topkara, Veli K; Mancini, Donna M; Yuzefpolskaya, Melana; Demmer, Ryan T; Dizon, Jose M; Takeda, Koji; Takayama, Hiroo; Naka, Yoshifumi; Colombo, Paolo C; Garan, A Reshad

2017-06-01

Implantable cardioverter defibrillators (ICDs) provide a significant mortality benefit for appropriately selected patients with advanced heart failure. ICDs are associated with a mortality benefit when used in patients with a pulsatile left ventricular assist device (LVAD). It is unclear whether patients with a continuous-flow LVAD (CF-LVAD) derive the same benefit. We sought to determine if the presence of an ICD provided a mortality benefit during CF-LVAD support as a bridge to transplantation. Patients were identified in the United Network for Organ Sharing (UNOS) registry who underwent LVAD implantation as bridge to transplantation between May 2004 and April 2014, with follow-up through June 2014. Primary outcome was freedom from death while on CF-LVAD support with adjustment for complications requiring UNOS listing status upgrade. Secondary end-points included freedom from delisting while on CF-LVAD support and incidence of transplantation. The study cohort comprised 2,990 patients, and propensity score matching identified 1,012 patients with similar propensity scores. There was no difference in survival during device support between patients with and without an ICD (hazard ratio [HR] = 1.20; 95% confidence interval [CI], 0.66-2.17; p = 0.55). Adjusting for device complications requiring a UNOS listing status upgrade had minimal influence (HR = 1.11; 95% CI, 0.60-2.05; p = 0.74). There was no increased risk of delisting owing to being too sick for patients with an ICD (HR = 1.08; 95% CI, 0.63-1.86; p = 0.78). Likewise, the probability of transplantation was similar (HR = 1.05; 95% CI, 0.87-1.27; p = 0.62). Among patients bridged to transplantation with a CF-LVAD, the presence of an ICD did not reduce mortality. Copyright © 2017 International Society for Heart and Lung Transplantation. Published by Elsevier Inc. All rights reserved.

Lund-Mackay and modified Lund-Mackay score for sinus surgery in children with cystic fibrosis.

PubMed

Do, Bao Anh; Lands, Larry C; Mascarella, Marco A; Fanous, Amanda; Saint-Martin, Christine; Manoukian, John J; Nguyen, Lily H P

2015-08-01

Patients with cystic fibrosis (CF) frequently present with severe sinonasal disease often requiring radiologic imaging and surgical intervention. Few studies have focused on the relationship between radiologic scoring systems and the need for sinus surgery in this population. The objective of this study is to evaluate the Lund-Mackay (LM) and modified Lund-Mackay (m-LM) scoring systems in predicting the need for sinus surgery or revision surgery in patients with CF. We performed a retrospective chart review of CF patients undergoing computed tomography (CT) sinus imaging at a tertiary care pediatric hospital from 1995 to 2008. Patient scans were scored using both the LM and m-LM systems and compared to the rate of sinus surgery or revision surgery. Receiver-operator characteristics curves (ROC) were used to analyze the radiological scoring systems. A total of 41 children with CF were included in the study. The mean LM score for patients undergoing surgery was 17.3 (±3.1) compared to 11.5 (±6.2) for those treated medically (p<0.01). For the m-LM, the mean score of patients undergoing surgery was 20.3 (±3.5) and 13.5 (±7.3) for those medically treated (p<0.01). Using a ROC curve with a threshold score of 13 for the LM, the sensitivity was 89.3% (95% CI of 72-98) and specificity of 69.2% (95% CI of 39-91). At an optimal score of 19, the m-LM system produced a sensitivity of 67.7% (95% CI of 48-84) and specificity of 84.6% (95% CI of 55-98). The modified Lund-Mackay score provides a high specificity while the Lund-Mackay score a high sensitivity for CF patients who required sinus surgery. The combination of both radiologic scoring systems can potentially predict the need for surgery in this population. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Cystic Fibrosis Pulmonary Exacerbations Attributable to Respiratory Syncytial Virus and Influenza: A Population-Based Study.

PubMed

Somayaji, Ranjani; Goss, Christopher H; Khan, Umer; Neradilek, Moni; Neuzil, Kathleen M; Ortiz, Justin R

2017-06-15

Characterization of the role of respiratory viral pathogens on cystic fibrosis (CF) pulmonary disease is needed. We aimed to determine the association of influenza and respiratory syncytial virus (RSV) activity with risk of pulmonary exacerbation (PEx) in persons with CF in the United States. We conducted a cohort study from January 2003 to March 2009 using the CF Foundation Patient Registry merged with Centers for Disease Control and Prevention respiratory virus surveillance data. The primary goal was to determine the association between regional influenza or RSV detections with risk of PEx requiring intravenous antibiotics or hospitalization. We analyzed outcomes by geographic region and week of event using multivariable regression models adjusted for demographic and clinical predictors of PEx stratified for children (<18 years) and adults (≥18 years) to calculate relative risks (RRs) of PEx. There were 21022 individuals (52% male) in the CF patient cohort in 2003 comprised of 12702 children and 8320 adults. The overall incidence rate of PEx was 521.9 per 10000 person-months. In children, a 10% increase in the proportion of surveillance tests positive for influenza or RSV was significantly associated with increased PEx risk (RR, 1.02; 95% confidence interval [CI], 1.01-1.03) and (RR, 1.05; 95% CI, 1.02-1.07), respectively. In adults, surveillance tests positive for influenza (RR, 1.02; 95% CI, 1.01-1.02), but not RSV (RR, 0.99; 95% CI, .98-1.01), had a significant association with PEx risk. Our large CF population-based cohort demonstrated a significant association between PEx risk and influenza activity in children and adults and with RSV activity in children. © The Author 2017. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail: journals.permissions@oup.com.

A new selective medium for Streptococcus mutans and the distribution of S. mutans and S. sobrinus and their serotypes in dental plaque.

PubMed

Hirasawa, M; Takada, K

2003-01-01

A new selective medium (MS-MUT) was developed for the isolation of Streptococcus mutans from clinical specimens. The average growth recovery of S. mutans on MS-MUT medium was 72.4% of that on MS medium. Growth of Streptococcus sobrinus was significantly inhibited on the medium with an average recovery of 0.034%. In 103 subjects, S. MUTANS was detected at 58.3, 75.0 and 95.7% in the dental plaque of caries-free (CF), caries-inactive (CI) and caries-active (CA) subjects, respectively. S. sobrinus was detected in 8.3, 13.6 and 38.3% of CF, CI and CA subjects, respectively. S. sobrinus alone was detected in only 4.3% of CA subjects. The subjects in whom neither S. mutans nor S. sobrinus were detected were 41.6% in CF and 25.0% in CI. The most predominant serotype was C with a 67% detection rate. S. sobrinus, serotypes D or G were usually found together with S. mutans. Copyright 2003 S. Karger AG, Basel

A Californium-252 Neutron Source for Student Use

ERIC Educational Resources Information Center

Bowen, H. J.

1975-01-01

Describes an undergraduate chemistry experiment which utilizes small samples of Californium 252 as a neutron source for the activation of 12 other elements. The students prepare decay curves of the radioactive isotopes and perform nondestructive activation analyses for gram amounts of some elements. (MLH)

Streptococcus pneumoniae oropharyngeal colonization in children and adolescents with cystic fibrosis.

PubMed

Esposito, Susanna; Colombo, Carla; Tosco, Antonella; Montemitro, Enza; Volpi, Sonia; Ruggiero, Luca; Lelii, Mara; Bisogno, Arianna; Pelucchi, Claudio; Principi, Nicola

2016-05-01

This study was designed to evaluate Streptococcus pneumoniae (S. pneumoniae) carriage rates in patients with cystic fibrosis (CF). An oropharyngeal swab was obtained from 212 CF children and adolescents enrolled during routine clinical visits. DNA from swabs was analyzed by real-time polymerase chain reaction. A total of 42 (19.8%) CF patients (mean age±standard deviation [SD], 12.0±3.3years) were colonized by S. pneumoniae. Carriage was more common in younger patients and tended to decline with age. Administration of systemic and/or inhaled antibiotics in the last 3months significantly correlated with a reduced carrier state [odds ratio (OR) 0.23, 95% confidence interval (CI) 0.07-0.69, and OR 0.26, 95% CI 0.08-0.77, respectively]. Vitamin D serum levels ≥30ng/mL were less common in carriers than that in non-carriers (OR 0.35; 95% CI 0.08-1.49). In both the vaccinated and unvaccinated subjects, serotypes 19F, 5, 4, and 9V were the most commonly carried serotypes. S. pneumoniae carrier state of school-age children and adolescents with CF is more prevalent than previously thought, and pneumococcal conjugate vaccination administered in the first year of life does not reduce the risk of re-colonization in later childhood and adolescence. Copyright © 2015. Published by Elsevier B.V.

Progressive ventilation inhomogeneity in infants with cystic fibrosis after pulmonary infection.

PubMed

Simpson, Shannon J; Ranganathan, Sarath; Park, Judy; Turkovic, Lidija; Robins-Browne, Roy M; Skoric, Billy; Ramsey, Kathryn A; Rosenow, Tim; Banton, Georgia L; Berry, Luke; Stick, Stephen M; Hall, Graham L

2015-12-01

Measures of ventilation distribution are promising for monitoring early lung disease in cystic fibrosis (CF). This study describes the cross-sectional and longitudinal impacts of pulmonary inflammation and infection on ventilation homogeneity in infants with CF.Infants diagnosed with CF underwent multiple breath washout (MBW) testing and bronchoalveolar lavage at three time points during the first 2 years of life.Measures were obtained for 108 infants on 156 occasions. Infants with a significant pulmonary infection at the time of MBW showed increases in lung clearance index (LCI) of 0.400 units (95% CI 0.150-0.648; p=0.002). The impact was long lasting, with previous pulmonary infection leading to increased ventilation inhomogeneity over time compared to those who remained free of infection (p<0.05). Infection with Haemophilus influenzae was particularly detrimental to the longitudinal lung function in young children with CF where LCI was increased by 1.069 units for each year of life (95% CI 0.484-1.612; p<0.001).Pulmonary infection during the first year of life is detrimental to later lung function. Therefore, strategies aimed at prevention, surveillance and eradication of pulmonary pathogens are paramount to preserve lung function in infants with CF. Copyright ©ERS 2015.

Measures of body habitus are associated with lung function in adults with cystic fibrosis: A population-based study☆

PubMed Central

Forrester, Doug L.; Knox, Alan J.; Smyth, Alan R.; Fogarty, Andrew W.

2013-01-01

Background Body habitus differences may explain some of the variation in lung function between individuals with cystic fibrosis (CF). We tested the hypothesis that measures of lean muscle mass and obesity are independently associated with lung function in CF. Methods Cross-sectional study design using UK CF registry data from 2096 clinically stable adults. Results Serum creatinine and BMI were positively and independently associated with FEV1 and FVC. One standard deviation increment in serum creatinine was associated with an FEV1 increase of 171 ml (95% confidence intervals CI: + 116 to + 227 ml) in males and 90 ml (95% CI: + 46 to + 133 ml) in females. Compared to the reference group of 20–24.9 kg/m2, those with a BMI < 20 kg/m2 had lower FEV1 with values of − 642 ml (95%CI: − 784 to − 500 ml) for males and − 468 ml (95%CI: − 564 to − 372 ml) for females. Conclusions Prospective studies and controlled trials are required to ascertain if these associations have therapeutic potential in modifying disease progression. PMID:22958983

Spontaneous Partitioning of Californium from Curium: Curious Cases from the Crystallization of Curium Coordination Complexes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cary, Samantha K.; Silver, Mark A.; Liu, Guokui

The reaction of 248CmCl3 with excess 2,6-pyridinedicarboxylic acid (DPA) under mild solvothermal conditions results in crystallization of the tris-chelate complex Cm(HDPA)3·H2O. Approximately half of the curium remains in solution at the end of this process, and evaporation of the mother liquor results in crystallization of the bis-chelate complex [Cm(HDPA)- (H2DPA)(H2O)2Cl]Cl·2H2O. 248Cm is the daughter of the α decay of 252Cf and is extracted in high purity from this parent. However, trace amounts of 249,250,251Cf are still present in all samples of 248Cm. During the crystallization of Cm(HDPA)3·H2O and [Cm(HDPA)(H2DPA)(H2O)2Cl]Cl·2H2O, californium(III) spontaneously separates itself from the curium complexes and is foundmore » doped within crystals of DPA in the form of Cf(HDPA)3. These results add to the growing body of evidence that the chemistry of californium is fundamentally different from that of earlier actinides.« less

HIV Infection Is Not Associated With Aortic Stiffness. Traditional Cardiovascular Risk Factors Are the Main Determinants-Cross-sectional Results of INI-ELSA-BRASIL.

PubMed

Moreira, Rodrigo C; Mill, José G; Grinsztejn, Beatriz; Veloso, Valdilea; Fonseca, Maria de Jesus; Griep, Rosane H; Bensenor, Isabela; Cardoso, Sandra W; Lotufo, Paulo; Chor, Dora; Pacheco, Antonio G

2018-05-01

Aortic stiffness measured by carotid-femoral pulse wave velocity (cf-PWV) is a marker of subclinical atherosclerosis. We propose to assess whether HIV infection is associated with arterial stiffness and their determinants in HIV-infected subjects. We compared data from an HIV cohort (644 patients, HIV+) in Rio de Janeiro with 2 groups: 105 HIV-negative (HIV-) individuals and 14,873 participants of the ELSA-Brasil study. We used multivariable linear regression to investigate factors associated with cf-PWV and whether HIV was independently associated with aortic stiffness and propensity score weighting to control for imbalances between groups. From 15,860 participants, cf-PWV was obtained in 15,622 (98.5%). Median age was 51 (interquartile range 45-58), 44.41 (35.73, 54.72), and 43.60 (36.01, 50.79) years (P < 0.001), and median cf-PWV (m/s; interquartile range) was 9.0 (8.10, 10.20), 8.70 (7.90, 10.20), and 8.48 (7.66, 9.40) for ELSA-Brasil, HIV- and HIV+, respectively (P < 0.001). In the final weighted multivariable models, HIV group was not associated with cf-PWV when compared either with ELSA-Brasil [β = -0.05; 95% confidence interval (CI) = -0.23; P = 0.12; P = 0.52] or with the HIV- groups (β = 0.10; 95% CI = -0.10; 0, 31; P = 0.32). Traditional risk factors were associated with higher cf-PWV levels in the HIV+ group, particularly waist-to-hip ratio (β = 0.20; 95% CI = 0.10; 0.30; P < 0.001, result per one SD change). HIV infection was not associated with higher aortic stiffness according to our study. In HIV-infected subjects, the stiffness of large arteries is mainly associated with traditional risk factors and not to the HIV infection per se.

Association between competitive food and beverage policies in elementary schools and childhood overweight/obesity trends: differences by neighborhood socioeconomic resources.

PubMed

Sanchez-Vaznaugh, Emma V; Sánchez, Brisa N; Crawford, Patricia B; Egerter, Susan

2015-05-01

To our knowledge, few published studies have examined the influence of competitive food and beverage (CF&B) policies on student weight outcomes; none have investigated disparities in the influence of CF&B policies on children's body weight by school neighborhood socioeconomic resources. To investigate whether the association between CF&B policies and population-level trends in childhood overweight/obesity differed by school neighborhood income and education levels. This cross-sectional study, from July 2013 to October 2014, compared overweight/obesity prevalence trends before (2001-2005) and after (2006-2010) implementation of CF&B policies in public elementary schools in California. The study included 2 700 880 fifth-grade students in 5362 public schools from 2001 to 2010. California CF&B policies (effective July 1, 2004, and July 1, 2007) and school neighborhood income and education levels. Overweight/obesity defined as a body mass index at or greater than the 85th percentile for age and sex. Overall rates of overweight/obesity ranged from 43.5% in 2001 to 45.8% in 2010. Compared with the period before the introduction of CF&B policies, overweight/obesity trends changed in a favorable direction after the policies took effect (2005-2010); these changes occurred for all children across all school neighborhood socioeconomic levels. In the postpolicy period, these trends differed by school neighborhood socioeconomic advantage. From 2005-2010, trends in overweight/obesity prevalence leveled off among students at schools in socioeconomically disadvantaged neighborhoods but declined in socioeconomically advantaged neighborhoods. Students in the lowest-income neighborhoods experienced zero or near zero change in the odds of overweight/obesity over time: the annual percentage change in overweight/obesity odds was 0.1% for females (95% CI, -0.7 to 0.9) and -0.3% for males (95% CI, -1.1 to 0.5). In contrast, in the highest-income neighborhoods, the annual percentage decline in the odds of overweight was 1.2% for females (95% CI, 0.4 to 1.9) and 1.0% for males (95% CI, 0.3 to 1.8). Findings were similar for school neighborhood education. Our study found population-level improvements in the prevalence of childhood overweight/obesity that coincided with the period following implementation of statewide CF&B policies (2005-2010). However, these improvements were greatest at schools in the most advantaged neighborhoods. This suggests that CF&B policies may help prevent child obesity; however, the degree of their effectiveness is likely to depend on socioeconomic and other contextual factors in school neighborhoods. To reduce disparities and prevent obesity, school policies and environmental interventions must address relevant contextual factors in school neighborhoods.

48 CFR 252.251-7000 - Ordering from Government supply sources.

Code of Federal Regulations, 2011 CFR

2011-10-01

... use without approval of the Contractor. (e) Government invoices shall be submitted to the Contractor's... 48 Federal Acquisition Regulations System 3 2011-10-01 2011-10-01 false Ordering from Government... CLAUSES Text of Provisions And Clauses 252.251-7000 Ordering from Government supply sources. As prescribed...

Collective Band Structures in the Neutron-Rich 107,109Ru Nuclei

NASA Astrophysics Data System (ADS)

Zhu, Sheng-jiang; Gan, Cui-yun; J, Hamilton H.; A, Ramayya V.; B, Babu R. S.; M, Sakhaee; W, Ma C.; Long, Gui-lu; Deng, Jing-kang; Zhu, Ling-yan; Li, Ming; Yang, Li-ming; J, Komicki; J, Cole D.; R, Aryaeinejad; Y, Dardenne K.; M, Drigert W.; J, Rasmussen O.; M, Stoyer A.; S, Chu Y.; K, Gregorich E.; M, Mohar F.; S, Prussin G.; I, Lee Y.; N, Johnson R.; F, McGowan K.

1998-11-01

The levels in neutron-rich odd-A 107,109Ru nuclei have been investigated by using γ-γ- and γ-γ-γ-coincidence studies of the prompt γ-rays from the spontaneous fission of 252Cf. The ground state bands and the negative parity bands are identified and expanded in both nuclei. Triaxial rotor plus particle model calculations indicate the ground state bands originate from ν(d5/2 + g7/2) quasiparticle configurations and the negative parity bands are from νh11/2 orbital.

Prospective evaluation of respiratory exacerbations in children with cystic fibrosis from newborn screening to 5 years of age

PubMed Central

Byrnes, Catherine Ann; Vidmar, Suzanna; Cheney, Joyce L; Carlin, John B; Armstrong, David S; Cooper, Peter J; Grimwood, Keith; Moodie, Marj; Robertson, Colin F; Rosenfeld, Margaret; Tiddens, Harm A; Wainwright, Claire E

2013-01-01

Background Newborn screening allows novel treatments for cystic fibrosis (CF) to be trialled in early childhood before irreversible lung injury occurs. As respiratory exacerbations are a potential trial outcome variable, we determined their rate, duration and clinical features in preschool children with CF; and whether they were associated with growth, lung structure and function at age 5 years. Methods Respiratory exacerbations were recorded prospectively in Australasian CF Bronchoalveolar Lavage trial subjects from enrolment after newborn screening to age 5 years, when all participants underwent clinical assessment, chest CT scans and spirometry. Results 168 children (88 boys) experienced 2080 exacerbations, at an average rate of 3.66 exacerbations per person-year; 80.1% were community managed and 19.9% required hospital admission. There was an average increase in exacerbation rate of 9% (95% CI 4% to 14%; p<0.001) per year of age. Exacerbation rate differed by site (p<0.001) and was 26% lower (95% CI 12% to 38%) in children receiving 12 months of prophylactic antibiotics. The rate of exacerbations in the first 2 years was associated with reduced forced expiratory volume in 1 s z scores. Ever having a hospital-managed exacerbation was associated with bronchiectasis (OR 2.67, 95% CI 1.13 to 6.31) in chest CT scans, and lower weight z scores at 5 years of age (coefficient −0.39, 95% CI −0.74 to −0.05). Conclusions Respiratory exacerbations in young children are markers for progressive CF lung disease and are potential trial outcome measures for novel treatments in this age group. PMID:23345574

Pseudomonas aeruginosa Genotype Prevalence in Dutch Cystic Fibrosis Patients and Age Dependency of Colonization by Various P. aeruginosa Sequence Types ▿

PubMed Central

van Mansfeld, Rosa; Willems, Rob; Brimicombe, Roland; Heijerman, Harry; van Berkhout, Ferdinand Teding; Wolfs, Tom; van der Ent, Cornelis; Bonten, Marc

2009-01-01

The patient-to-patient transmission of highly prevalent Pseudomonas aeruginosa clones which are associated with enhanced disease progression has led to strict segregation policies for cystic fibrosis (CF) patients in many countries. However, little is known about the population structure of P. aeruginosa among CF patients. The aim of the present cross-sectional study was to determine the prevalence and genetic relatedness of P. aeruginosa isolates from CF patients who visited two major CF centers in The Netherlands in 2007 and 2008. These patients represented 45% of the Dutch CF population. P. aeruginosa carriage in the respiratory tract was determined by standard microbiological culture techniques, and all phenotypically different isolates in the first specimens recovered in 2007 and 2008 were genotyped by multilocus sequence typing. A total of 313 (57%) of 551 patients whose samples were cultured carried P. aeruginosa. Two sequence types (STs), ST406 and ST497, were found in 15% and 5% of the patients, respectively, and 60% of the patients harbored a strain that was also found in at least two other patients. The risk ratios for carrying ST406 and ST497 were 17.8 (95% confidence interval [CI], 7.2 to 43.6) for those aged between 15 and 24 years and 6 (95% CI, 1.4 to 26.1) for those aged >25 years. ST406 and ST497 were not genetically linked to previously described epidemic clones, which were also not found in this CF population. The population structure of P. aeruginosa in Dutch CF patients is characterized by the presence of two prevalent STs that are associated with certain age groups and that are not genetically linked to previously described epidemic clones. PMID:19828746

Influence of SNPs in Genes that Modulate Lung Disease Severity in a Group of Mexican Patients with Cystic Fibrosis.

PubMed

Yokoyama, Emiy; Chávez-Saldaña, Margarita; Orozco, Lorena; Cuevas, Francisco; Lezana, José Luis; Vigueras-Villaseñor, Rosa María; Rojas-Castañeda, Julio Cesar; Landero, Daniel Adrian

2018-04-24

The variation in cystic fibrosis (CF) lung disease not always is explained by the CFTR genotype, so it has become apparent that modifier genes must play a considerable role in the phenotypic heterogeneity of CF, so we investigated the association of allelic variants in modifier genes that modulate the severity of lung function in a group of Mexican patients diagnosed with CF. We included 140 CF patients classified according to lung phenotype and analyzed 17 single nucleotide polymorphisms (SNPs) by TaqMan ® allelic discrimination. We demonstrated that patients with GG or GC genotype of the allelic variant rs11003125 (MBL2-550) of the MBL2 gene exhibit most of the lung manifestations at an earlier age; and the rs1042713 allelic variant of ADRB2 gene, showed statistical difference only with the age of first spirometry. When we used the dominant model, the MBL2 allele rs11003125 (MBL2-550; p = 0.022, Odds Ratio (OR) 2.87, 95% CI 1.14-7.27) was significantly associated with CF patients as risk factor, and the ADRB2 allele rs1042713 (p.Arg16Gly; p = 0.005, Odds Ratio (OR) 0.37, 95% CI 0.19-0.75) was significantly associated with CF patients as protect factor. Our findings suggest that the MBL2 and ADRB2 genes exerts an important genetic influence on the lung disease in our patients. Taking into account our results, we insist on not leaving aside this type of studies, since having techniques such as GWAS or WES will be able to advance in achieving a better quality of life for CF patients with severe lung disease. Copyright © 2018 IMSS. Published by Elsevier Inc. All rights reserved.

Apparatus and method for quantitative assay of generic transuranic wastes from nuclear reactors

DOEpatents

Caldwell, J.T.; Kunz, W.E.; Atencio, J.D.

1982-03-31

A combination of passive and active neutron measurements which yields quantitative information about the isotopic composition of transuranic wastes from nuclear power or weapons material manufacture reactors is described. From the measurement of prompt and delayed neutron emission and the incidence of two coincidentally emitted neutrons from induced fission of fissile material in the sample, one can quantify /sup 233/U, /sup 235/U and /sup 239/Pu isotopes in waste samples. Passive coincidence counting, including neutron multiplicity measurement and determination of the overall passive neutron flux additionally enables the separate quantitative evaluation of spontaneous fission isotopes such as /sup 240/Pu, /sup 244/Cm and /sup 252/Cf, and the spontaneous alpha particle emitter /sup 241/Am. These seven isotopes are the most important constituents of wastes from nuclear power reactors and once the mass of each isotope present is determined by the apparatus and method of the instant invention, the overall alpha particle activity can be determined to better than 1 nCi/g from known radioactivity data. Therefore, in addition to the quantitative analysis of the waste sample useful for later reclamation purposes, the alpha particle activity can be determined to decide whether permanent low-level burial is appropriate for the waste sample.

Apparatus and method for quantitative assay of generic transuranic wastes from nuclear reactors

DOEpatents

Caldwell, John T.; Kunz, Walter E.; Atencio, James D.

1984-01-01

A combination of passive and active neutron measurements which yields quantitative information about the isotopic composition of transuranic wastes from nuclear power or weapons material manufacture reactors is described. From the measurement of prompt and delayed neutron emission and the incidence of two coincidentally emitted neutrons from induced fission of fissile material in the sample, one can quantify .sup.233 U, .sup.235 U and .sup.239 Pu isotopes in waste samples. Passive coincidence counting, including neutron multiplicity measurement and determination of the overall passive neutron flux additionally enables the separate quantitative evaluation of spontaneous fission isotopes such as .sup.240 Pu, .sup.244 Cm and .sup.252 Cf, and the spontaneous alpha particle emitter .sup.241 Am. These seven isotopes are the most important constituents of wastes from nuclear power reactors and once the mass of each isotope present is determined by the apparatus and method of the instant invention, the overall alpha particle activity can be determined to better than 1 nCi/g from known radioactivity data. Therefore, in addition to the quantitative analysis of the waste sample useful for later reclamation purposes, the alpha particle activity can be determined to decide whether "permanent" low-level burial is appropriate for the waste sample.

Association between Type, Amount, and Pattern of Carbohydrate Consumption with Dental Caries in 12-Year-Olds in Puerto Rico.

PubMed

Palacios, Cristina; Rivas-Tumanyan, Sona; Morou-Bermúdez, Evangelia; Colon, Alina M; Torres, Roxana Y; Elías-Boneta, Augusto R

2016-01-01

To identify the types, food sources, and pattern of carbohydrates that significantly contribute to dental caries in Puerto Rican children. As part of an island-wide cross-sectional oral health study in 1,587 twelve-year-olds, diet intake was assessed in a representative subset (n = 801) with a 24-hour dietary recall. Carbohydrate intake was quantified using a computer-based diet analysis program. Caries was assessed using the National Institute of Dental and Craniofacial Research diagnostic criteria. Odds ratios were used to associate carbohydrate intake quartiles with caries, after controlling for important confounders. A total of 723 subjects had complete data. Most were females (54%) and attended public schools (77%). The caries prevalence was 33%. The highest quartile intake for the following sugars significantly increased the odds of caries compared to the lowest quartile: total carbohydrates (OR = 1.93, 95% CI = 1.08-3.46), total sugars (OR = 1.88, 95% CI = 1.01-351), sucrose (OR = 2.05, 95% CI = 1.13-3.70), fructose (OR = 1.95, 95% CI = 1.05-3.62), and inositol (OR = 2.52, 95% CI = 1.38-4.63). The main food sources of these sugars were juices, including natural juices with no added sugars, and sweetened beverages. The odds of caries also increased significantly in children whose 10% of total energy intake was from total sugars (OR = 3.76, 95% CI = 1.03-13.7). After adjusting for important caries risk factors, total carbohydrates, total sugars, ≥10% kilocaloric energy from total sugars, and sucrose, fructose, and inositol intake significantly increased caries risk. Our findings can help raise awareness about the potential caries risk from the main sources of these sugars, natural fruit juices and sweetened beverages, which are consumed in great quantities in many societies. © 2016 S. Karger AG, Basel.

Association between type, amount and pattern of carbohydrate consumption with dental caries in 12-year-olds in Puerto Rico

PubMed Central

Palacios, Cristina; Rivas-Tumanyan, Sona; Morou-Bermúdez, Evangelia; Colón, Alina M.; Torres, Roxana Y; Elías-Boneta, Augusto R.

2017-01-01

Objective To identify the types, food sources, and pattern of carbohydrates that significantly contribute to dental caries in Puerto Rican children. Methods As part of an island-wide oral health cross-sectional study in 1,587 12 years-olds, diet intake was assessed in a representative subset (n=801) with a 24-hr dietary recall. Carbohydrates’ intake was quantified using a computer-based diet analysis program. Caries was assessed using the NIDCR diagnostic criteria. Odds ratios were used to associate carbohydrate intake quartiles with caries, after controlling for important confounders. Results A total of 723 subjects had complete data. Most were females (54%) and attended public schools (77%). Caries prevalence was 33%. The highest quartile intake for the following sugars significantly increased the odds of caries compared to the lowest quartile: total carbohydrates (OR=1.93, 95% CI: 1.08–3.46), total sugars (OR=1.88, 95% CI: 1.01–351), sucrose (OR=2.05, 95% CI: 1.13–3.70), fructose (OR=1.95, 95% CI: 1.05–3.62) and inositol (OR=2.52, 95% CI: 1.38–4.63). The main food sources of these sugars were juices, including natural juices with no added sugars, and sweetened beverages. The odds of caries also increased significantly in children whose 10% of total energy intake was from total sugars (OR=3.76, 95% CI:1.03–13.7). Conclusion After adjusting for important caries risk factors, total carbohydrates, total sugars, ≥10% kcal from total sugars, sucrose, fructose and inositol intake significantly increased caries risk. Our findings can help raise awareness about the potential caries risk of the main sources of these sugars, natural fruit juices and sweetened beverages, which are highly consumed in many societies. PMID:27788518

New fit of thermal neutron constants (TNC) for 233,235U, 239,241Pu and 252Cf(sf): Microscopic vs. maxwellian data

NASA Astrophysics Data System (ADS)

Pronyaev, Vladimir G.; Capote, Roberto; Trkov, Andrej; Noguere, Gilles; Wallner, Anton

2017-09-01

An IAEA project to update the Neutron Standards is near completion. Traditionally, the Thermal Neutron Constants (TNC) evaluated data by Axton for thermal-neutron scattering, capture and fission on four fissile nuclei and the total nu-bar of 252Cf(sf) are used as input in the combined least-square fit with neutron cross section standards. The evaluation by Axton (1986) was based on a least-square fit of both thermal-spectrum averaged cross sections (Maxwellian data) and microscopic cross sections at 2200 m/s. There is a second Axton evaluation based exclusively on measured microscopic cross sections at 2200 m/s (excluding Maxwellian data). Both evaluations disagree within quoted uncertainties for fission and capture cross sections and total multiplicities of uranium isotopes. There are two factors, which may lead to such difference: Westcott g-factors with estimated 0.2% uncertainties used in the Axton's fit, and deviation of the thermal spectra from Maxwellian shape. To exclude or mitigate the impact of these factors, a new combined GMA fit of standards was undertaken with Axton's TNC evaluation based on 2200 m/s data used as a prior. New microscopic data at the thermal point, available since 1986, were added to the combined fit. Additionally, an independent evaluation of TNC was undertaken using CONRAD code. Both GMA and CONRAD results are consistent within quoted uncertainties. New evaluation shows a small increase of fission and capture thermal cross sections, and a corresponding decrease in evaluated thermal nubar for uranium isotopes and 239Pu.

Future research program on prompt γ-ray emission in nuclear fission

NASA Astrophysics Data System (ADS)

Oberstedt, S.; Billnert, R.; Hambsch, F.-J.; Lebois, M.; Oberstedt, A.; Wilson, J. N.

2015-12-01

In recent years the measurement of prompt fission γ-ray spectra (PFGS) has gained renewed interest, after about forty years since the first comprehensive studies of the reactions 235U(n th , f), 239Pu(n th ,f) and 252Cf(sf). The renaissance was initiated by requests for new values especially for γ-ray multiplicity and average total energy release per fission in neutron-induced fission of 235U and 239Pu. Both isotopes are considered the most important ones with respect to the modeling of innovative cores required for the Generation-IV reactors, the majority working with fast neutrons. During the last 5 years we have conducted a systematic study of spectral data for thermal-neutron-induced fission on 235U and 241Pu as well as for the spontaneous fission of 252Cf with unprecedented accuracy. From the new data we conclude that those reactions do not considerably contribute to the observed heat excess and suspect other reactions playing a significant role. Possible contributions may originate from fast-neutron-induced reactions on 238U, which is largely present in the fuel, or from γ-induced fission from neutron capture in the construction material. A first experiment campaign on prompt γ-ray emission from fast-neutron-induced fission on 235,238U was successfully performed in order to test our assumptions. In the following we attempt to summarize, what has been done in the field to date, and to motivate future measurement campaigns exploiting dedicated neutron and photon beams as well as upcoming highly efficient detector assemblies.

Measurement of nitrogen in the body using a commercial PGNAA system--phantom experiments.

PubMed

Chichester, D L; Empey, E

2004-01-01

An industrial prompt-gamma neutron activation analysis (PGNAA) system, originally designed for the real-time elemental analyses of bulk coal on a conveyor belt, has been studied to examine the feasibility of using such a system for body composition analysis. Experiments were conducted to measure nitrogen in a simple, tissue equivalent phantom comprised of 2.7 wt% of nitrogen. The neutron source for these experiments was 365 MBq (18.38 microg) of 252Cf located within an engineered low Z moderator and it yielded a dose rate in the measurement position of 3.91 mSv/h; data were collected using a 2780 cm(3) NaI(Tl) cylindrical detector with a digital signal processor and a 512 channel MCA. Source, moderator and detector geometries were unaltered from the system's standard configuration, where they have been optimized for considerations such as neutron thermalization, measurement sensitivity and uniformity, background radiation and external dose minimization. Based on net counts in the 10.8 MeV PGNAA nitrogen photopeak and its escape peaks the dose dependent nitrogen count rate was 11,600 counts/mSv with an uncertainty of 3.0% after 0.32 mSv (4.9 min), 2.0% after 0.74 mSv (11.4 min) and 1.0% after 3.02 mSv (46.4 min).

Development and Characterization of a High Sensitivity Segmented Fast Neutron Spectrometer (FaNS-2)

PubMed Central

Langford, T.J.; Beise, E.J.; Breuer, H.; Heimbach, C.R.; Ji, G.; Nico, J.S.

2016-01-01

We present the development of a segmented fast neutron spectrometer (FaNS-2) based upon plastic scintillator and 3He proportional counters. It was designed to measure both the flux and spectrum of fast neutrons in the energy range of few MeV to 1 GeV. FaNS-2 utilizes capture-gated spectroscopy to identify neutron events and reject backgrounds. Neutrons deposit energy in the plastic scintillator before capturing on a 3He nucleus in the proportional counters. Segmentation improves neutron energy reconstruction while the large volume of scintillator increases sensitivity to low neutron fluxes. A main goal of its design is to study comparatively low neutron fluxes, such as cosmogenic neutrons at the Earth's surface, in an underground environment, or from low-activity neutron sources. In this paper, we present details of its design and construction as well as its characterization with a calibrated 252Cf source and monoenergetic neutron fields of 2.5 MeV and 14 MeV. Detected monoenergetic neutron spectra are unfolded using a Singular Value Decomposition method, demonstrating a 5% energy resolution at 14 MeV. Finally, we discuss plans for measuring the surface and underground cosmogenic neutron spectra with FaNS-2. PMID:27226807

Characterization of a tin-loaded liquid scintillator for gamma spectroscopy and neutron detection

NASA Astrophysics Data System (ADS)

Wen, Xianfei; Harvey, Taylor; Weinmann-Smith, Robert; Walker, James; Noh, Young; Farley, Richard; Enqvist, Andreas

2018-07-01

A tin-loaded liquid scintillator has been developed for gamma spectroscopy and neutron detection. The scintillator was characterized in regard to energy resolution, pulse shape discrimination, neutron light output function, and timing resolution. The loading of tin into scintillators with low effective atomic number was demonstrated to provide photopeaks with acceptable energy resolution. The scintillator was shown to have reasonable neutron/gamma discrimination capability based on the charge comparison method. The effect on the discrimination quality of the total charge integration time and the initial delay time for tail charge integration was studied. To obtain the neutron light output function, the time-of-flight technique was utilized with a 252Cf source. The light output function was validated with the MCNPX-PoliMi code by comparing the measured and simulated pule height spectra. The timing resolution of the developed scintillator was also evaluated. The tin-loading was found to have negligible impact on the scintillation decay times. However, a relatively large degradation of timing resolution was observed due to the reduced light yield.

PVT-NG sensor final report.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mitchell, Dean James; Brusseau, Charles A.

2012-01-01

This document is a final report for the polyvinyl toluene (PVT) neutron-gamma (PVT-NG) project, which was sponsored by the Domestic Nuclear Detection Office (DNDO). The PVT-NG sensor uses PVT detectors for both gamma and neutron detection. The sensor exhibits excellent spectral resolution and gain stabilization, which are features that are beneficial for detection of both gamma-ray and neutron sources. In fact, the ability to perform isotope identification based on spectra that were measured by the PVT-NG sensor was demonstrated. As described in a previous report, the neutron sensitivity of the first version of the prototype was about 25% less thanmore » the DNDO requirement of 2.5 cps/ng for bare Cf-252. This document describes design modifications that were expected to improve the neutron sensitivity by about 50% relative to the PVT-NG prototype. However, the project was terminated before execution of the design modifications after portal vendors demonstrated other technologies that enable neutron detection without the use of He-3. Nevertheless, the PVT-NG sensor development demonstrated several performance goals that may be useful in future portal designs.« less

Non destructive multi elemental analysis using prompt gamma neutron activation analysis techniques: Preliminary results for concrete sample

NASA Astrophysics Data System (ADS)

Dahing, Lahasen@Normanshah; Yahya, Redzuan; Yahya, Roslan; Hassan, Hearie

2014-09-01

In this study, principle of prompt gamma neutron activation analysis has been used as a technique to determine the elements in the sample. The system consists of collimated isotopic neutron source, Cf-252 with HPGe detector and Multichannel Analysis (MCA). Concrete with size of 10×10×10 cm3 and 15×15×15 cm3 were analysed as sample. When neutrons enter and interact with elements in the concrete, the neutron capture reaction will occur and produce characteristic prompt gamma ray of the elements. The preliminary result of this study demonstrate the major element in the concrete was determined such as Si, Mg, Ca, Al, Fe and H as well as others element, such as Cl by analysis the gamma ray lines respectively. The results obtained were compared with NAA and XRF techniques as a part of reference and validation. The potential and the capability of neutron induced prompt gamma as tool for multi elemental analysis qualitatively to identify the elements present in the concrete sample discussed.

Detection of Landmines by Neutron Backscattering: Effects of Soil Moisture on the Detection System

DOE Office of Scientific and Technical Information (OSTI.GOV)

Baysoy, D. Y.; Subasi, M.

2010-01-21

Detection of buried land mines by using neutron backscattering technique (NBS) is a well established method. It depends on detecting a hydrogen anomaly in dry soil. Since a landmine and its plastic casing contain much more hydrogen atoms than the dry soil, this anomaly can be detected by observing a rise in the number of neutrons moderated to thermal or epithermal energy. But, the presence of moisture in the soil limits the effectiveness of the measurements. In this work, a landmine detection system using the NBS technique was designed. A series of Monte Carlo calculations was carried out to determinemore » the limits of the system due to the moisture content of the soil. In the simulations, an isotropic fast neutron source ({sup 252}Cf, 100 mug) and a neutron detection system which consists of five {sup 3}He detectors were used in a practicable geometry. In order to see the effects of soil moisture on the efficiency of the detection system, soils with different water contents were tested.« less

Investigation of the response of a neutron-Hand monitor dedicated to the powder diffractometer at CENM-Maamora

DOE Office of Scientific and Technical Information (OSTI.GOV)

Messous, M.Y.; Belhorma, B.; Labrim, H.

2015-07-01

Neutrons are used for the study of condensed matter. A neutron beam can indeed easily penetrate the solid material and undergo diffraction phenomena. Analysis of the diffused neutrons allows studying the atomic structure of crossed material. Their neutral electric charge makes them nondestructive probe of a great interest. In general, the size of the powder samples is very small and therefore the centering of the beam on these is very crucial. It is in this context we proceed to test a portable neutron monitor for centering and checking beam leak around the shielding to be installed around the diffractometer inmore » TRIGA Mark II of CENM. It's consisting of a scintillation neutron detector NE426 ({sup 6}LiF + ZnS (Ag)) with electronic module and data acquisition system. The effect of radiation from radioactive neutrons source {sup 252}Cf is shown. Sensitivity and differential linearity are also performed. This study indicates several advantages of this detector with very good detection sensitivity and excellent stability during the counting time. (authors)« less

Assessing and minimizing contamination in time of flight based validation data

NASA Astrophysics Data System (ADS)

Lennox, Kristin P.; Rosenfield, Paul; Blair, Brenton; Kaplan, Alan; Ruz, Jaime; Glenn, Andrew; Wurtz, Ronald

2017-10-01

Time of flight experiments are the gold standard method for generating labeled training and testing data for the neutron/gamma pulse shape discrimination problem. As the popularity of supervised classification methods increases in this field, there will also be increasing reliance on time of flight data for algorithm development and evaluation. However, time of flight experiments are subject to various sources of contamination that lead to neutron and gamma pulses being mislabeled. Such labeling errors have a detrimental effect on classification algorithm training and testing, and should therefore be minimized. This paper presents a method for identifying minimally contaminated data sets from time of flight experiments and estimating the residual contamination rate. This method leverages statistical models describing neutron and gamma travel time distributions and is easily implemented using existing statistical software. The method produces a set of optimal intervals that balance the trade-off between interval size and nuisance particle contamination, and its use is demonstrated on a time of flight data set for Cf-252. The particular properties of the optimal intervals for the demonstration data are explored in detail.

Association Between Competitive Food and Beverage Policies in Elementary Schools and Childhood Overweight/Obesity Trends

PubMed Central

Sanchez-Vaznaugh, Emma V.; Sánchez, Brisa N.; Crawford, Patricia B.; Egerter, Susan

2015-01-01

IMPORTANCE To our knowledge, few published studies have examined the influence of competitive food and beverage (CF&B) policies on student weight outcomes; none have investigated disparities in the influence of CF&B policies on children’s body weight by school neighborhood socioeconomic resources. OBJECTIVE To investigate whether the association between CF&B policies and population-level trends in childhood overweight/obesity differed by school neighborhood income and education levels. DESIGN, SETTING, AND PARTICIPANTS This cross-sectional study, from July 2013 to October 2014, compared overweight/obesity prevalence trends before (2001–2005) and after (2006–2010) implementation of CF&B policies in public elementary schools in California. The study included 2 700 880 fifth-grade students in 5362 public schools from 2001 to 2010. EXPOSURES California CF&B policies (effective July 1, 2004, and July 1, 2007) and school neighborhood income and education levels. MAIN OUTCOMES AND MEASURES Overweight/obesity defined as a body mass index at or greater than the 85th percentile for age and sex. RESULTS Overall rates of overweight/obesity ranged from 43.5% in 2001 to 45.8% in 2010. Compared with the period before the introduction of CF&B policies, overweight/obesity trends changed in a favorable direction after the policies took effect (2005–2010); these changes occurred for all children across all school neighborhood socioeconomic levels. In the postpolicy period, these trends differed by school neighborhood socioeconomic advantage. From 2005–2010, trends in overweight/obesity prevalence leveled off among students at schools in socioeconomically disadvantaged neighborhoods but declined in socioeconomically advantaged neighborhoods. Students in the lowest-income neighborhoods experienced zero or near zero change in the odds of overweight/obesity over time: the annual percentage change in overweight/obesity odds was 0.1% for females (95% CI, −0.7 to 0.9) and −0.3% for males (95% CI, −1.1 to 0.5). In contrast, in the highest-income neighborhoods, the annual percentage decline in the odds of overweight was 1.2% for females (95% CI, 0.4 to 1.9) and 1.0% for males (95% CI, 0.3 to 1.8). Findings were similar for school neighborhood education. CONCLUSIONS AND RELEVANCE Our study found population-level improvements in the prevalence of childhood overweight/obesity that coincided with the period following implementation of statewide CF&B policies (2005–2010). However, these improvements were greatest at schools in the most advantaged neighborhoods. This suggests that CF&B policies may help prevent child obesity; however, the degree of their effectiveness is likely to depend on socioeconomic and other contextual factors in school neighborhoods. To reduce disparities and prevent obesity, school policies and environmental interventions must address relevant contextual factors in school neighborhoods. PMID:25938657

Risk of asthma in heterozygous carriers for cystic fibrosis: A meta-analysis.

PubMed

Nielsen, Anne Orholm; Qayum, Sadaf; Bouchelouche, Pierre Nourdine; Laursen, Lars Christian; Dahl, Ronald; Dahl, Morten

2016-09-01

Patients with cystic fibrosis (CF) have a higher prevalence of asthma than the background population, however, it is unclear whether heterozygous CF carriers are susceptible to asthma. Given this, a meta-analysis is necessary to determine the veracity of the association of CF heterozygosity with asthma. We screened the medical literature from 1966 to 2015 and performed a meta-analysis to determine the risk of asthma in CF heterozygotes vs. non-carriers. Aggregating data from 15 studies, the odds ratio for asthma in CF heterozygotes compared with non-carriers was significantly elevated at 1.61 (95% CI: 1.18-2.21). When analyzing the studies considered of high quality in which asthma was diagnosed by a physician, the patients were >18years, or study size was ≥500, the trend remained the same, that heterozygous carriers of CF had elevated risk for asthma. The results show that heterozygous carriers for CF have a higher risk of asthma than non-carriers. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

Effects of Diagnosis by Newborn Screening for Cystic Fibrosis on Weight and Length in the First Year of Life.

PubMed

Leung, Daniel H; Heltshe, Sonya L; Borowitz, Drucy; Gelfond, Daniel; Kloster, Margaret; Heubi, James E; Stalvey, Michael; Ramsey, Bonnie W

2017-06-01

Since the implementation of universal newborn screening (NBS) for cystic fibrosis (CF), the timing and magnitude of growth deficiency or its association with correlates of disease among infants with CF who underwent NBS has not been well described. To examine incremental weight gain, linear growth, and clinical features in the first year of life among infants with CF who underwent NBS. The Baby Observational and Nutrition Study (BONUS), a multicenter, longitudinal, observational cohort study, was conducted during regular CF clinic visits in the first 12 months of life at 28 US Cystic Fibrosis Foundation-accredited Care Centers from January 7, 2012, through May 31, 2015. Participants included 231 infants younger than 3.5 months who underwent NBS and had confirmed CF, with a gestational age of at least 35 weeks, birth weight of at least 2.5 kg, and toleration of full oral feeds. Of these, 222 infants (96.1%) had follow-up beyond 6 months of age and 215 (93.1%) completed 12 months of follow-up. Cystic fibrosis. Attained weight and length for age and World Health Organization normative z scores at ages 1 to 6 and 8, 10, and 12 months (defined a priori). Of the 231 infants enrolled, 110 infants (47.6%) were female and 121 (52.4%) were male, with a mean (SD) age of 2.58 (0.69) months. BONUS infants had lower than mean birth weights (mean z score, -0.15; 95% CI, -0.27 to -0.04) and higher birth lengths (mean z score, 0.44; 95% CI, 0.26 to 0.62). They achieved normal weight by 12 months, a significant improvement over a prescreening cohort of newborns with CF from 20 years before the contemporary cohort (mean z score increase, 0.57; 95% CI, 0.37-0.77). However, length was lower than the mean at 12 months (mean z score, -0.56; 95% CI, -0.70 to -0.42). Only 30 infants (13.6%) were at less than the 10th percentile of weight for age, whereas 53 (23.9%) were at less than the 10th percentile of length for age at more than half their visits. Male sex, pancreatic insufficiency, meconium ileus, histamine blocker use, and respiratory Pseudomonas aeruginosa infection were associated with lower weight or length during the first year. Insulinlike growth factor 1 levels were significantly lower among low-length infants. Persistently low-weight infants consumed significantly more calories, and weight and length z scores were negatively correlated with caloric intake. Since initiation of universal NBS for CF, significant improvement has occurred in nutritional status, with normalization of weight in the first year of life. However, length stunting remains common.

Electrical and Environmental Studies of Conduction Polymers.

DTIC Science & Technology

1986-01-17

Carbonate), 0.25M Tetrabutylammonium hexafluorophosphate (Bu4 NPF 6 )/THF, and 0.25M Lithium Trifluoromethyl sulfonate (LiCF3 SO 3)frHF. Lithium ...processible polymeric component Other anions commonly used in synthesizing polypyrrole, namely, tetrafluoroborate, hexafluorophosphate rifluoromethyl...are perchlorate (CI0 4 "), tetrafluoroborate (BF 4 "), trifluoromethyl sulfonate (CF3 SO"), hexafluorophosphate (PF6 ") and p-toluene sulfonate (PTS

Experimental Constraints on Neutrino Spectra Following Fission

NASA Astrophysics Data System (ADS)

Napolitano, Jim; Daya Bay Collaboration

2016-09-01

We discuss new initiatives to constrain predictions of fission neutrino spectra from nuclear reactors. These predictions are germane to the understanding of reactor flux anomalies; are needed to reduce systematic uncertainty in neutrino oscillation spectra; and inform searches for the diffuse supernova neutrino background. The initiatives include a search for very high- Q beta decay components to the neutrino spectrum from the Daya Bay power plant; plans for a measurement of the β- spectrum from 252Cf fission products; and precision measurements of the 235U fission neutrino spectrum from PROSPECT and other very short baseline reactor experiments.

New excitations in Ba 142 and Ce 144 : Evolution of γ bands in the N = 86 isotones

DOE PAGES

Naidja, H.; Nowacki, F.; Bounthong, B.; ...

2017-06-02

New excited states in 142Ba and 144Ce are investigated by means of prompt γ-ray spectroscopy of the radiation following spontaneous fission of 252Cf. Measurements of angular correlations and the observed branchings allowed the assignment of spins and parities with confidence. The new measurements are reinforced by shell-model calculations where energy levels, electric transitions, and magnetic moments are consistent with experimental data. Lastly, the presence of collectivity in the N = 86 isotones is confirmed by clear signatures of soft triaxial γ bands in both nuclei.

Lung clearance index to monitor treatment response in pulmonary exacerbations in preschool children with cystic fibrosis.

PubMed

Rayment, Jonathan H; Stanojevic, Sanja; Davis, Stephanie D; Retsch-Bogart, George; Ratjen, Felix

2018-05-01

Antibiotic treatment for pulmonary symptoms in preschool children with cystic fibrosis (CF) varies among clinicians. The lung clearance index (LCI) is sensitive to early CF lung disease, but its utility to monitor pulmonary exacerbations in young children has not been assessed. We aim to (1) understand how LCI changes during lower respiratory tract symptoms relative to a recent clinically stable measurement, (2) determine whether LCI can identify antibiotic treatment response and (3) compare LCI changes to changes in spirometric indices. LCI and spirometry were measured at quarterly clinic visits over a 12-month period in preschool children with CF. Symptomatic visits were identified and classified as treated or untreated. Treatment response was estimated using propensity score matching methods. 104 symptomatic visits were identified in 78 participants. LCI increased from baseline in both treated (mean relative change +23.8% (95% CI 16.2 to 31.4)) and untreated symptomatic visits (mean relative change +11.2% (95% CI 2.4 to 19.9)). A significant antibiotic treatment effect was observed when LCI was used as the outcome measure (average treatment effect -15.5% (95% CI -25.4 to -5.6)) but not for z-score FEV 1 . LCI significantly deteriorated with pulmonary symptoms relative to baseline and improved with antibiotic treatment. These data suggest that LCI may have a role in the routine clinical care of preschool children with CF. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

ESR1 and PIK3CA mutational status in serum and plasma from metastatic breast cancer patients: A comparative study.

PubMed

Takeshita, Takashi; Yamamoto, Yutaka; Yamamoto-Ibusuki, Mutsuko; Tomiguchi, Mai; Sueta, Aiko; Iwase, Hirotaka

2018-04-07

Plasma and serum cell-free DNA (cfDNA) are useful sources of tumor DNA, but comparative investigations of the tumor mutational status between them are rare. we performed droplet digital PCR assay for representative hotspot mutations in metastatic breast cancer (MBC) (ESR1 and PIK3CA) in serum and plasma cfDNA concurrently extracted from the blood of 33 estrogen receptor-positive MBC patients. ESR1 mutations in plasma cfDNA were found in 7 of the 33 patients; ESR1 mutations in serum cfDNA were detected in only one out of 7 patients with ESR1 mutations in plasma cfDNA. PIK3CA exon 9 and exon 20 mutations in plasma cfDNA were found in 3 and 7 out of the 33 patients, respectively; PIK3CA exon 9 mutations in serum cfDNA were detected in 2 out of 3 patients with PIK3CA exon 9 mutations in plasma cfDNA; PIK3CA exon 20 mutations in serum cfDNA were detected in 2 out of 7 patients with PIK3CA exon 20 mutations in plasma cfDNA. Here we show the higher frequency of ESR1 and PIK3CA mutations in the plasma than in the serum in 33 MBC patients; therefore, serum samples should not be considered the preferred source of cfDNA.

In situ CF3 Detection in Low Pressure Inductive Discharges by Fourier Transform Infrared Spectroscopy

NASA Technical Reports Server (NTRS)

Kim, J. S.; Cappelli, M. A.; Sharma, S. P.; Arnold, J. O. (Technical Monitor)

1998-01-01

The detection of CF(x) (x=1-3) radicals in low pressure discharges using source gases such as CF4 and CHF3 is of importance to the understanding of their chemical structure and relevance in plasma based etching processes. These radicals are known to contribute to the formation of fluorocarbon polymer films, which affect the selectivity and anisotropy of etching. In this study, we present preliminary results of the quantitative measurement of trifluoromethyl radicals, CF3, in low pressure discharges. The discharge studied here is an inductively (transformer) coupled plasma (ICP) source in the GEC reference cell, operating on pure CF4 at pressures ranging from 10 - 100 mTorr, This plasma source generates higher electron number densities at lower operating pressures than obtainable with the parallel-plate capacitively coupled version of the GEC reference cell. Also, this expanded operating regime is more relevant to new generations of industrial plasma reactors being used by the microelectronics industry. Fourier transform infrared (FTIR) spectroscopy is employed to observe the absorption band of CF3 radicals in the electronic ground state X2Al in the region of 1233-1270/cm. The spectrometer is equipped with a high sensitivity HgCdTe (MCT) detector and has a fixed resolution of 0.125/cm. The CF3 concentrations are measured for a range of operating pressures and discharge power levels.

Homelessness among a cohort of women in street-based sex work: the need for safer environment interventions.

PubMed

Duff, Putu; Deering, Kathleen; Gibson, Kate; Tyndall, Mark; Shannon, Kate

2011-08-12

Drawing on data from a community-based prospective cohort study in Vancouver, Canada, we examined the prevalence and individual, interpersonal and work environment correlates of homelessness among 252 women in street-based sex work. Bivariate and multivariate logistic regression using generalized estimating equations (GEE) was used to examine the individual, interpersonal and work environment factors that were associated with homelessness among street-based sex workers. Among 252 women, 43.3% reported homelessness over an 18-month follow-up period. In the multivariable GEE logistic regression analysis, younger age (adjusted odds ratio [aOR] = 0.93; 95%confidence interval [95%CI] 0.93-0.98), sexual violence by non-commercial partners (aOR = 2.14; 95%CI 1.06-4.34), servicing a higher number of clients (10+ per week vs < 10) (aOR = 1.68; 95%CI 1.05-2.69), intensive, daily crack use (aOR = 1.65; 95%CI 1.11-2.45), and servicing clients in public spaces (aOR = 1.52; CI 1.00-2.31) were independently associated with sleeping on the street. These findings indicate a critical need for safer environment interventions that mitigate the social and physical risks faced by homeless FSWs and increase access to safe, secure housing for women.

Optimizing moderation of He-3 neutron detectors for shielded fission sources

DOE PAGES

Rees, Lawrence B.; Czirr, J. Bart

2012-07-10

Abstract: The response of 3-He neutron detectors is highly dependent on the amount of moderator incorporated into the detector system. If there is too little moderation, neutrons will not react with the 3-He. If there is too much moderation, neutrons will not reach the 3-He. In applications for portal or border monitors where 3He detectors are used to interdict illicit Importation of plutonium, the fission source is always shielded to some extent. Since the energy distribution of neutrons emitted from the source depends on the amount and type of shielding present, the optimum placement of moderating material around 3-He tubesmore » is a function of shielding. In this paper, we use Monte Carlo techniques to model the response of 3-He tubes placed in polyethylene boxes for moderation. To model the shielded fission neutron source, we use a 252-Cf source placed in the center of spheres of water of varying radius. Detector efficiency as a function of box geometry and shielding are explored. We find that increasing the amount of moderator behind and to the sides of the detector generally improves the detector response, but that benefits are limited if the thickness of the polyethylene moderator is greater than about 5-7 cm. The thickness of the moderator in front of the 3He tubes, however, is very important. For bare sources, about 5-6 cm of moderator is optimum, but as the shielding increases, the optimum thickness of this moderator decreases to 0-1 cm. A two-tube box with a moderator thickness of 5 cm in front of the first tube and a thickness of 1 cm in front of the second tube is proposed to improve the detector's sensitivity to lower-energy neutrons.« less

Energy spectra unfolding of fast neutron sources using the group method of data handling and decision tree algorithms

NASA Astrophysics Data System (ADS)

Hosseini, Seyed Abolfazl; Afrakoti, Iman Esmaili Paeen

2017-04-01

Accurate unfolding of the energy spectrum of a neutron source gives important information about unknown neutron sources. The obtained information is useful in many areas like nuclear safeguards, nuclear nonproliferation, and homeland security. In the present study, the energy spectrum of a poly-energetic fast neutron source is reconstructed using the developed computational codes based on the Group Method of Data Handling (GMDH) and Decision Tree (DT) algorithms. The neutron pulse height distribution (neutron response function) in the considered NE-213 liquid organic scintillator has been simulated using the developed MCNPX-ESUT computational code (MCNPX-Energy engineering of Sharif University of Technology). The developed computational codes based on the GMDH and DT algorithms use some data for training, testing and validation steps. In order to prepare the required data, 4000 randomly generated energy spectra distributed over 52 bins are used. The randomly generated energy spectra and the simulated neutron pulse height distributions by MCNPX-ESUT for each energy spectrum are used as the output and input data. Since there is no need to solve the inverse problem with an ill-conditioned response matrix, the unfolded energy spectrum has the highest accuracy. The 241Am-9Be and 252Cf neutron sources are used in the validation step of the calculation. The unfolded energy spectra for the used fast neutron sources have an excellent agreement with the reference ones. Also, the accuracy of the unfolded energy spectra obtained using the GMDH is slightly better than those obtained from the DT. The results obtained in the present study have good accuracy in comparison with the previously published paper based on the logsig and tansig transfer functions.

Organic liquid scintillation detectors for on-the-fly neutron/gamma alarming and radionuclide identification in a pedestrian radiation portal monitor

NASA Astrophysics Data System (ADS)

Paff, Marc Gerrit; Ruch, Marc L.; Poitrasson-Riviere, Alexis; Sagadevan, Athena; Clarke, Shaun D.; Pozzi, Sara

2015-07-01

We present new experimental results from a radiation portal monitor based on the use of organic liquid scintillators. The system was tested as part of a 3He-free radiation portal monitor testing campaign at the European Commission's Joint Research Centre in Ispra, Italy, in February 2014. The radiation portal monitor was subjected to a wide range of test conditions described in ANSI N42.35, including a variety of gamma-ray sources and a 20,000 n/s 252Cf source. A false alarm test tested whether radiation portal monitors ever alarmed in the presence of only natural background. The University of Michigan Detection for Nuclear Nonproliferation Group's system triggered zero false alarms in 2739 trials. It consistently alarmed on a variety of gamma-ray sources travelling at 1.2 m/s at a 70 cm source to detector distance. The neutron source was detected at speeds up to 3 m/s and in configurations with up to 8 cm of high density polyethylene shielding. The success of on-the-fly radionuclide identification varied with the gamma-ray source measured as well as with which of two radionuclide identification methods was used. Both methods used a least squares comparison between the measured pulse height distributions to library spectra to pick the best match. The methods varied in how the pulse height distributions were modified prior to the least squares comparison. Correct identification rates were as high as 100% for highly enriched uranium, but as low as 50% for 241Am. Both radionuclide identification algorithms produced mixed results, but the concept of using liquid scintillation detectors for gamma-ray and neutron alarming in radiation portal monitor was validated.

The Role of Implantable Cardioverter Defibrillators in Patients Bridged to Transplantation with a Continuous Flow Left Ventricular Assist Device: A Propensity Score Matched Analysis

PubMed Central

Clerkin, Kevin J.; Topkara, Veli K.; Mancini, Donna M.; Yuzefpolskaya, Melana; Demmer, Ryan T.; Dizon, Jose M.; Takeda, Koji; Takayama, Hiroo; Naka, Yoshifumi; Colombo, Paolo C.; Garan, A. Reshad

2016-01-01

Background Implantable cardioverter defibrillators (ICD) provide a significant mortality benefit for appropriately selected patients with advanced heart failure. ICDs are associated with a mortality benefit when used in patients with a pulsatile left ventricular assist device (LVAD). However it is unclear whether patients with a continuous flow LVAD (CF-LVAD) derive the same benefit. This study sought to determine if the presence of an ICD provided a mortality benefit during CFLVAD support as a bridge to transplantation. Methods Patients were identified in the United Network for Organ Sharing (UNOS) registry that underwent LVAD implantation as bridge to transplantation from May 2004 and April 2014, with follow-up through June 2014. The primary outcome was freedom from death while on CF-LVAD support with adjustment for complications requiring UNOS listing status upgrade. Secondary endpoints included freedom from delisting while on CF-LVAD support and incidence of transplantation. Results 2,990 patients composed the study cohort and propensity score matching identified 1,012 patients with similar propensity scores. There was no difference in survival during device support between patients with and without an ICD (Hazard Ratio [HR] 1.20, 95% Confidence Interval [CI] 0.66-2.17, p=0.55). Adjusting for device complications requiring a UNOS listing status upgrade had minimal influence (HR 1.11, 95% CI 0.60-2.05, p=0.74). There was no increased risk of delisting due to being too sick for those with an ICD (HR 1.08, 95% CI 0.63-1.86, p=0.78). Likewise, the probability of transplantation was similar (HR 1.05, 95% CI 0.87-1.27, p=0.62). Conclusions Among patients bridged to transplantation with a CF-LVAD, the presence of an ICD did not reduce mortality. PMID:28089072

INHALED HYPERTONIC SALINE IN INFANTS AND CHILDREN LESS THAN SIX YEARS OF AGE WITH CYSTIC FIBROSIS: THE ISIS RANDOMIZED TRIAL

PubMed Central

Rosenfeld, Margaret; Ratjen, Felix; Brumback, Lyndia; Daniel, Stephen; Rowbotham, Ron; McNamara, Sharon; Johnson, Robin; Kronmal, Richard; Davis, Stephanie D

2013-01-01

Context Inhaled hypertonic saline is recommended as therapy for cystic fibrosis (CF) patients 6 years of age and older, but its efficacy has never been evaluated in CF patients <6 years of age. Objective To determine if hypertonic saline reduces the rate of protocol-defined pulmonary exacerbations in CF patients <6 years of age. Design and Setting A multicenter, randomized, double-blind placebo-controlled trial was conducted from April 2009 to October 2011 at 30 CF care centers in the United States and Canada. Participants Participants had an established diagnosis of CF and were 4 to 60 months of age. A total of 344 patients were assessed for eligibility; 321 participants were randomized; 29 (9%) withdrew prematurely. Intervention The active group (n=158) received 7% hypertonic saline and the control group (n=163) received 0.9% isotonic saline nebulized twice daily for 48 weeks. Both groups received albuterol or levalbuterol prior to each study drug dose. Main Outcome Measures the rate of protocol-defined pulmonary exacerbations during the 48 week treatment period treated with oral, inhaled or intravenous antibiotics. Results The mean pulmonary exacerbation rate (events/person-year) was 2.3 (95% CI, 2.0, 2.5) in the hypertonic saline group and 2.3 (95% CI, 2.1, 2.6) in the isotonic saline group; the rate ratio was 0.98 (95% CI, 0.84, 1.14)). Among participants with pulmonary exacerbations, the mean number of total antibiotic treatment days for a pulmonary exacerbation was 60 (95% CI 49, 70) in the hypertonic saline group and 52 (95% CI 43, 61) in the isotonic saline group. There was no significant difference in secondary endpoints including height, weight, respiratory rate, oxygen saturation, cough or respiratory symptom scores. Infant pulmonary function testing performed as an exploratory outcome in a subgroup (N=73, with acceptable measurements at 2 visits in 45) did not demonstrate significant differences between groups except for the mean change in forced expiratory volume in 0.5 seconds which was 38 ml greater (95% CI 1, 76) in the hypertonic saline group. Adherence by returned study drug ampoules was at least 75% in each group. Adverse event profiles were also similar, with the most common adverse event of moderate or severe severity in each group being cough (39% of hypertonic saline group, 38% of isotonic saline group). Conclusions Among infants and children with cystic fibrosis less than 6 years old, the use of inhaled hypertonic saline compared with isotonic saline did not reduce the rate of pulmonary exacerbations over 48 weeks of treatment. Trial Registration www.clinicaltrials.gov NCT00709280 PMID:22610452

Pulmonary artery enlargement and cystic fibrosis pulmonary exacerbations: a cohort study

PubMed Central

Wells, J. Michael; Farris, Roopan F.; Gosdin, Taylor A.; Dransfield, Mark T.; Wood, Michelle E.; Bell, Scott C.; Rowe, Steven M.

2017-01-01

Background Acute pulmonary exacerbations are associated with progressive lung function decline and increased mortality in cystic fibrosis (CF). The role of pulmonary vascular disease in pulmonary exacerbations is unknown. We investigated the association between pulmonary artery enlargement (PA:A>1), a marker of pulmonary vascular disease, and exacerbations. Methods We analyzed clinical, computed tomography (CT), and prospective exacerbation data in a derivation cohort of 74 adult CF patients, measuring the PA:A at the level of the PA bifurcation. We then replicated our findings in a validation cohort of 190 adult CF patients. Patients were separated into groups based on the presence or absence of a PA:A>1 and were followed for 1-year in the derivation cohort and 2-years in the validation cohort. The primary endpoint was developing ≥1 acute pulmonary exacerbation during follow-up. Linear and logistic regression models were used to determine associations between clinical factors, the PA:A ratio, and pulmonary exacerbations. We used Cox regression to determine time to first exacerbation in the validation cohort. Findings We found that PA:A>1 was present in n=37/74 (50%) of the derivation and n=89/190 (47%) of the validation cohort. In the derivation cohort, n=50/74 (68%) had ≥1 exacerbation at 1 year and n=133/190 (70%) in the validation cohort had ≥1 exacerbation after 2 years. PA:A>1 was associated with younger age in both cohorts and with elevated sweat chloride (100.5±10.9 versus 90.4±19.9mmol/L, difference between groups 10.1mmol/L [95%CI 2.5–17.7], P=0.017) in the derivation group. PA:A>1 was associated with exacerbations in the derivation (OR 3.49, 95%CI 1.18–10.3, P=0.023) and validation (OR 2.41, 95%CI 1.06–5.52, P=0.037) cohorts when adjusted for confounders. Time to first exacerbation was shorter in PA:A>1 versus PA:A<1 [HR 1.66 (95%CI 1.18–2.34), P=0.004] in unadjusted analysis, but not when adjusted for sex, BMI, prior exacerbation, positive Pseudomonas status, and FEV1/FVC [HR 1.14 (95%CI 0.80–1.62), P=0.82]). Interpretation PA enlargement is prevalent in adult CF patients and is associated with acute pulmonary exacerbation risk in two well-characterized cohorts. PA:A may be a predictive marker in CF. PMID:27298019

Comparison of pulse wave velocity and pulse pressure amplification in association with target organ damage in community-dwelling elderly: The Northern Shanghai Study.

PubMed

Bai, Bin; Teliewubai, Jiadela; Lu, Yuyan; Yu, Shikai; Xiong, Jing; Chi, Chen; Zhou, Yiwu; Ji, Hongwei; Fan, Ximin; Blacher, Jacques; Li, Jue; Zhang, Yi; Xu, Yawei

2018-05-01

This study aimed to investigate the discrepancy between pulse wave velocity (PWV) and pulse pressure amplification (PPA) in association with hypertensive target organ damage (TOD) in the elderly. From June 2014 to August 2015, 1599 participants aged >65 years old from communities located in northern Shanghai were recruited. Carotid-femoral pulse wave velocity (cfPWV), peripheral blood pressure (BP), central BP and other TOD indicators, including the ratio of the early ventricular filling velocity (E) to the peak velocity of the tissue Doppler velocity of septal mitral annulus (E/Ea), left ventricular mass index (LVMI), carotid intima-medium thickness (CIMT), estimated glomerular filtration rate (eGFR), and urinary albumin-creatinine ratio (ACR), were determined for each participant. PPA was defined as the peripheral-to-central pulse pressure ratio. In multivariable linear regression analysis, cfPWV was significantly associated with CIMT (β = 12.83 ± 4.28 μm per SD; P = 0.003) and eGFR (β = -1.85 ± 0.69 ml/min/1.73 m 2 per SD; P = 0.007), whereas PPA was significantly associated with E/Ea (β = -0.25 ± 0.10 per SD; P = 0.01) and LVMI (β = -3.00 ± 0.78 g/m 2 per SD; P < 0.001). Similarly, in multivariable logistic regression analysis, cfPWV was significantly associated with arterial plaque (odds ratio [OR], 1.21 [95% confidence interval [CI], 1.05-1.39]; P = 0.007), peripheral artery disease (OR, 1.22 [95% CI, 1.06-1.42]; P = 0.007), chronic kidney diseases (OR, 1.24 [95% CI, 1.01-1.54]; P = 0.04) and microalbuminuria (OR, 1.21 [95% CI, 1.07-1.37]; P = 0.002), while PPA was tightly associated with left ventricular hypertrophy (OR, 0.85 [95% CI, 0.72-0.99]; P = 0.04) and diastolic dysfunction (OR, 0.78 [95% CI, 0.64-0.96]; P = 0.02). In conclusion, cfPWV is a vessel-related and renal-related biomarker, while PPA is a cardiac-related biomarker in community-based elderly.

The psychometric properties of the Leicester Cough Questionnaire and Respiratory Symptoms in CF tool in cystic fibrosis: A preliminary study.

PubMed

Ward, Nathan; Stiller, Kathy; Rowe, Hilary; Holland, Anne E

2017-05-01

There are few tools to quantify the impact of cough in cystic fibrosis (CF). The psychometric properties of the Leicester Cough Questionnaire (LCQ) and Respiratory Symptoms in CF (ReS-CF) tool were investigated in adults with CF. Validity and reliability were assessed in clinically stable participants who completed the questionnaires twice, along with the Cystic Fibrosis Questionnaire - Revised (CFQ-R). Responsiveness was assessed by change in questionnaires following treatment for an acute respiratory exacerbation. Correlations between the LCQ and CFQ-R respiratory domain were moderate (n=59, r s =0.78, p<0.001). Correlations between ReS-CF and CFQ-R respiratory domain were fair (r s =-0.50, p<0.001). The LCQ total score was repeatable (ICC 0.92, 95%CI 0.87-0.96, n=50). In those reporting improvement in symptoms following treatment (n=36), LCQ total score had a mean change of 4.6 (SD 3.7) and effect size of 1.2. The LCQ and ReS-CF appear to be valid, reliable and responsive in CF. www.anzctr.org.au: ACTRN12615000262505. Copyright © 2016 European Cystic Fibrosis Society. Published by Elsevier B.V. All rights reserved.

Perforated semiconductor neutron detectors for battery operated portable modules

NASA Astrophysics Data System (ADS)

McGregor, Douglas S.; Bellinger, Steven L.; Bruno, David; McNeil, Walter J.; Patterson, Eric; Shultis, J. Kenneth; Solomon, C. J.; Unruh, Troy

2007-09-01

Perforated semiconductor diode detectors have been under development for several years at Kansas State University for a variety of neutron detection applications. The fundamental device configuration is a pin diode detector fabricated from high-purity float zone refined Si wafers. Perforations are etched into the diode surface with inductively-coupled plasma (ICP) reactive ion etching (RIE) and backfilled with 6LiF neutron reactive material. The perforation shapes and depths can be optimized to yield a flat response to neutrons over a wide variation of angles. The prototype devices delivered over 3.8% thermal neutron detection efficiency while operating on only 15 volts. The highest efficiency devices thus far have delivered over 12% thermal neutron detection efficiency. The miniature devices are 5.6 mm in diameter and require minimal power to operate, ranging from 3.3 volts to 15 volts, depending upon the amplifying electronics. The battery operated devices have been incorporated into compact modules with a digital readout. Further, the new modules have incorporated wireless readout technology and can be monitored remotely. The neutron detection modules can be used for neutron dosimetry and neutron monitoring. When coupled with high-density polyethylene, the detectors can be used to measure fission neutrons from spontaneous fission sources. Monto Carlo analysis indicates that the devices can be used in cargo containers as a passive search tool for spontaneous fission sources, such as 240Pu. Measurements with a 252Cf source are being conducted for verification.

In situ capture gamma-ray analysis of coal in an oversize borehole

USGS Publications Warehouse

Mikesell, J.L.; Dotson, D.W.; Senftle, F.E.; Zych, R.S.; Koger, J.; Goldman, L.

1983-01-01

In situ capture gamma-ray analysis in a coal seam using a high resolution gamma-ray spectrometer in a close-fitting borehole has been reported previously. In order to check the accuracy of the method under adverse conditions, similar measurements were made by means of a small-diameter sonde in an oversize borehole in the Pittsburgh seam, Greene County, Pennsylvania. The hole was 5 times the diameter of the sonde, a ratio that substantially increased the contribution of water (hydrogen) to the total spectral count and reduced the size of the sample measured by the detector. The total natural count, the 40K,count, and the intensities of capture gamma rays from Si, Ca, H, and Al were determined as a function of depth above, through, and below the coal seam. From these logs, the depth and width of the coal seam and its partings were determined. Spectra were accumulated in the seam for 1 h periods by using neutron sources of different strengths. From the spectra obtained by means of several 252Cf neutron sources of different sizes, the ultimate elemental analysis and ash content were determined. The results were not as good as those obtained previously in a close-fitting borehole. However, the results did improve with successively larger source-to-detector distances, i.e.,as the count contribution due to hydrogen in the water decreased. It was concluded that in situ borehole analyses should be made in relatively close-fitting boreholes. ?? 1983.

Studies on new neutron-sensitive dosimeters using an optically stimulated luminescence technique

NASA Astrophysics Data System (ADS)

Kulkarni, M. S.; Luszik-Bhadra, M.; Behrens, R.; Muthe, K. P.; Rawat, N. S.; Gupta, S. K.; Sharma, D. N.

2011-07-01

The neutron response of detectors prepared using α-Al 2O 3:C phosphor developed using a melt processing technique and mixed with neutron converters was studied in monoenergetic neutron fields. The detector pellets were arranged in two different pairs: α-Al 2O 3:C + 6LiF/α-Al 2O 3:C + 7LiF and α-Al 2O 3:C + high-density polyethylene/α-Al 2O 3:C + Teflon, for neutron dosimetry using albedo and recoil proton techniques. The optically stimulated luminescence response of the Al 2O 3:C + 6,7LiF dosimeter to radiation from a 252Cf source was 0.21, in terms of personal dose equivalent Hp(10) and relative to radiation from a 137Cs source. This was comparable to results obtained with similar detectors prepared using commercially available α-Al 2O 3:C phosphor. The Hp(10) response of the α-Al 2O 3:C + 6,7LiF dosimeters was found to decrease by more than two orders of magnitude with increasing neutron energy, as expected for albedo dosimeters. The response of the α-Al 2O 3:C + high-density polyethylene/α-Al 2O 3:C + Teflon dosimeters was small, of the order of 1% to 2% in terms of Hp(10) and relative to radiation from a 137Cs source, for neutron energies greater than 1 MeV.

Study of a nTHGEM-based thermal neutron detector

NASA Astrophysics Data System (ADS)

Li, Ke; Zhou, Jian-Rong; Wang, Xiao-Dong; Xiong, Tao; Zhang, Ying; Xie, Yu-Guang; Zhou, Liang; Xu, Hong; Yang, Gui-An; Wang, Yan-Feng; Wang, Yan; Wu, Jin-Jie; Sun, Zhi-Jia; Hu, Bi-Tao

2016-07-01

With new generation neutron sources, traditional neutron detectors cannot satisfy the demands of the applications, especially under high flux. Furthermore, facing the global crisis in 3He gas supply, research on new types of neutron detector as an alternative to 3He is a research hotspot in the field of particle detection. GEM (Gaseous Electron Multiplier) neutron detectors have high counting rate, good spatial and time resolution, and could be one future direction of the development of neutron detectors. In this paper, the physical process of neutron detection is simulated with Geant4 code, studying the relations between thermal conversion efficiency, boron thickness and number of boron layers. Due to the special characteristics of neutron detection, we have developed a novel type of special ceramic nTHGEM (neutron THick GEM) for neutron detection. The performance of the nTHGEM working in different Ar/CO2 mixtures is presented, including measurements of the gain and the count rate plateau using a copper target X-ray source. A detector with a single nTHGEM has been tested for 2-D imaging using a 252Cf neutron source. The key parameters of the performance of the nTHGEM detector have been obtained, providing necessary experimental data as a reference for further research on this detector. Supported by National Natural Science Foundation of China (11127508, 11175199, 11205253, 11405191), Key Laboratory of Neutron Physics, CAEP (2013DB06, 2013BB04) and CAS (YZ201512)

Occupational exposure to lead and lung cancer: results from two case-control studies in Montreal, Canada.

PubMed

Wynant, Willy; Siemiatycki, Jack; Parent, Marie-Élise; Rousseau, Marie-Claude

2013-03-01

We investigated the association between workplace lead exposure and lung cancer risk, separately for organic lead and for inorganic lead, from either engine emissions or from other sources. Two population-based case-control studies were carried out in Montreal (1979-1986 and 1996-2002) to investigate occupational factors in relation to lung cancer among 1593 men with histologically confirmed incident lung cancer, and 1426 controls from the general population. Interviews elicited information on sociodemographic characteristics, lifetime smoking and occupational history. Chemists translated each job into potential chemical exposures. Cumulative indices of exposure were derived and classified into non-substantial and substantial exposure. ORs adjusted for several potential confounders including smoking, and 95% CIs were estimated by logistic regression. Lifetime prevalences of exposure in Study I were 3% for organic lead, 40% for inorganic lead from engine emissions and 17% for inorganic lead from other sources; corresponding prevalences in Study II were 4%, 19% and 16%, respectively. No associations were observed when comparing ever to never exposed subjects in pooled analyses (organic lead, OR=1.39, 95% CI 0.77 to 2.52; inorganic lead from engine emissions: OR=0.89, 95% CI 0.72 to 1.09; inorganic lead from other sources: OR=0.99, 95% CI 0.76 to 1.29). Nor were these exposures associated with lung cancer in subjects with substantial cumulative exposure. In this large study, using a blinded expert-based assessment of lifetime occupational exposure and adjustment for several potential confounders, we observed no increased risk of lung cancer with exposure to lead compounds.

Cell-free DNA as a molecular tool for monitoring disease progression and response to therapy in breast cancer patients.

PubMed

Liang, Diana H; Ensor, Joe E; Liu, Zhe-Bin; Patel, Asmita; Patel, Tejal A; Chang, Jenny C; Rodriguez, Angel A

2016-01-01

Due to the spatial and temporal genomic heterogeneity of breast cancer, genomic sequencing obtained from a single biopsy may not capture the complete genomic profile of tumors. Thus, we propose that cell-free DNA (cfDNA) in plasma may be an alternate source of genomic information to provide comprehensive data throughout a patient's clinical course. We performed a retrospective chart review of 100 patients with stage 4 or high-risk stage 3 breast cancer. The degree of agreement between genomic alterations found in tumor DNA (tDNA) and cfDNA was determined by Cohen's Kappa. Clinical disease progression was compared to mutant allele frequency using a two-sided Fisher's exact test. The presence of mutations and mutant allele frequency was correlated with progression-free survival (PFS) using a Cox proportional hazards model and a log-rank test. The most commonly found genomic alterations were mutations in TP53 and PIK3CA, and amplification of EGFR and ERBB2. PIK3CA mutation and ERBB2 amplification demonstrated robust agreement between tDNA and cfDNA (Cohen's kappa = 0.64 and 0.77, respectively). TP53 mutation and EGFR amplification demonstrated poor agreement between tDNA and cfDNA (Cohen's kappa = 0.18 and 0.33, respectively). The directional changes of TP53 and PIK3CA mutant allele frequency were closely associated with response to therapy (p = 0.002). The presence of TP53 mutation (p = 0.0004) and PIK3CA mutant allele frequency [p = 0.01, HR 1.074 (95 % CI 1.018-1.134)] was excellent predictors of PFS. Identification of selected cancer-specific genomic alterations from cfDNA may be a noninvasive way to monitor disease progression, predict PFS, and offer targeted therapy.

Dosimetric comparison between intensity-modulated with coplanar field and 3D conformal radiotherapy with noncoplanar field for postocular invasion tumor.

PubMed

Wenyong, Tu; Lu, Liu; Jun, Zeng; Weidong, Yin; Yun, Li

2010-01-01

This study presents a dosimetric optimization effort aiming to compare noncoplanar field (NCF) on 3 dimensions conformal radiotherapy (3D-CRT) and coplanar field (CF) on intensity-modulated radiotherapy (IMRT) planning for postocular invasion tumor. We performed a planning study on the computed tomography data of 8 consecutive patients with localized postocular invasion tumor. Four fields NCF 3D-CRT in the transverse plane with gantry angles of 0-10 degrees , 30-45 degrees , 240-270 degrees , and 310-335 degrees degrees were isocentered at the center of gravity of the target volume. The geometry of the beams was determined by beam's eye view. The same constraints were prepared with between CF IMRT optimization and NCF 3D-CRT treatment. The maximum point doses (D max) for the different optic pathway structures (OPS) with NCF 3D-CRT treatment should differ in no more than 3% from those with the NCF IMRT plan. Dose-volume histograms (DVHs) were obtained for all targets and organ at risk (OAR) with both treatment techniques. Plans with NCF 3D-CRT and CF IMRT constraints on target dose in homogeneity were computed, as well as the conformity index (CI) and homogeneity index (HI) in the target volume. The PTV coverage was optimal with both NCF 3D-CRT and CF IMRT plans in the 8 tumor sites. No difference was noted between the two techniques for the average D(max) and D(min) dose. NCF 3D-CRT and CF IMRT will yield similar results on CI. However, HI was a significant difference between NCF 3D-CRT and CF IMRT plan (p < 0.001). Physical endpoints for target showed the mean target dose to be low in the CF IMRT plan, caused by a large target dose in homogeneity (p < 0.001). The impact of NCF 3D-CRT versus CF IMRT set-up is very slight. NCF3D-CRT is one of the treatment options for postocular invasion tumor. However, constraints for OARs are needed. 2010 American Association of Medical Dosimetrists. Published by Elsevier Inc. All rights reserved.

Design and verification of the shielding around the new Neutron Standards Laboratory (LPN) at CIEMAT.

PubMed

Méndez-Villafañe, R; Guerrero, J E; Embid, M; Fernández, R; Grandio, R; Pérez-Cejuela, P; Márquez, J L; Alvarez, F; Ortego, P

2014-10-01

The construction of the new Neutron Standards Laboratory at CIEMAT (Laboratorio de Patrones Neutrónicos) has been finalised and is ready to provide service. The facility is an ∼8 m×8 m×8 m irradiation vault, following the International Organization for Standardization 8529 recommendations. It relies on several neutron sources: a 5-GBq (5.8× 10(8) s(-1)) (252)Cf source and two (241)Am-Be neutron sources (185 and 11.1 GBq). The irradiation point is located 4 m over the ground level and in the geometrical centre of the room. Each neutron source can be moved remotely from its storage position inside a water pool to the irradiation point. Prior to this, an important task to design the neutron shielding and to choose the most appropriate materials has been developed by the Radiological Security Unit and the Ionizing Radiations Metrology Laboratory. MCNPX was chosen to simulate the irradiation facility. With this information the walls were built with a thickness of 125 cm. Special attention was put on the weak points (main door, air conditioning system, etc.) so that the ambient dose outside the facility was below the regulatory limits. Finally, the Radiation Protection Unit carried out a set of measurements in specific points around the installation with an LB6411 neutron monitor and a Reuter-Stokes high-pressure ion chamber to verify experimentally the results of the simulation. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Development of prototype induced-fission-based Pu accountancy instrument for safeguards applications.

PubMed

Seo, Hee; Lee, Seung Kyu; An, Su Jung; Park, Se-Hwan; Ku, Jeong-Hoe; Menlove, Howard O; Rael, Carlos D; LaFleur, Adrienne M; Browne, Michael C

2016-09-01

Prototype safeguards instrument for nuclear material accountancy (NMA) of uranium/transuranic (U/TRU) products that could be produced in a future advanced PWR fuel processing facility has been developed and characterized. This is a new, hybrid neutron measurement system based on fast neutron energy multiplication (FNEM) and passive neutron albedo reactivity (PNAR) methods. The FNEM method is sensitive to the induced fission rate by fast neutrons, while the PNAR method is sensitive to the induced fission rate by thermal neutrons in the sample to be measured. The induced fission rate is proportional to the total amount of fissile material, especially plutonium (Pu), in the U/TRU product; hence, the Pu amount can be calibrated as a function of the induced fission rate, which can be measured using either the FNEM or PNAR method. In the present study, the prototype system was built using six (3)He tubes, and its performance was evaluated for various detector parameters including high-voltage (HV) plateau, efficiency profiles, dead time, and stability. The system's capability to measure the difference in the average neutron energy for the FNEM signature also was evaluated, using AmLi, PuBe, (252)Cf, as well as four Pu-oxide sources each with a different impurity (Al, F, Mg, and B) and producing (α,n) neutrons with different average energies. Future work will measure the hybrid signature (i.e., FNEM×PNAR) for a Pu source with an external interrogating neutron source after enlarging the cavity size of the prototype system to accommodate a large-size Pu source (~600g Pu). Copyright © 2016 Elsevier Ltd. All rights reserved.

Cell Free DNA and Procalcitonin as Early Markers of Complications in ICU Patients with Multiple Trauma and Major Surgery.

PubMed

Ahmed, Asmaa I; Soliman, Randa A; Samir, Shereif

2016-12-01

Cell free DNA (cfDNA) was recently suggested as a new marker of sepsis and poor outcome in ICU patients. Procalcitonin has also been the focus of attention as an early marker for systemic inflammation and sepsis. cfDNA, procalcitonin (PCT), C-reactive protein (CRP), and lactate levels were measured in 30 ICU patients with multiple trauma or after major surgery on the first day of admission and on 5th and 7th days for PCT, CRP, and lactate. cfDNA was measured by real-time PCR, PCT by ELISA, CRP immunoturbidimetrically, and lactate spectrophotometrically. SOFA score and Injury Severity Score (ISS) for trauma patients were calculated. Significantly higher levels of cfDNA were observed in non-survivor patients in comparison to survivors and in patients with sepsis in comparison to those without sepsis (p = 0.002 and p = 0.02, respectively). The ROC curve was calculated for cfDNA as a predictor of outcome, the area under the curve (AUC) was 0.847 (95% CI: 0.669 - 0.952), at a cutoff value of 15500 ng/µL, sensitivity = 83.3%, specificity = 77.8% (p < 0.0001). As a prognostic marker of sepsis, the AUC for cfDNA was 0.788 (95% CI: 0.601 - 0.915), sensitivity = 56.25%, specificity = 100% (p = 0.0007). Day 5 PCT levels significantly correlated with SOFA scores on day 5, ISS on admission (p < 0.001 and p = 0.028, respectively), and a significant elevation of its levels was observed in non-survivor patients compared to survivors (p = 0.001). As a predictor of sepsis, PCT showed a sensitivity of 81.3%, specificity of 100% on day 5, (AUC: 0.987, 95% CI: 0.955 - 1.00); at a cutoff value of 202.90 pg/mL (p = 0.001). As a predictor of outcome, PCT on day 5 showed a sensitivity of 94.0% and a specificity of 78.0% at a cutoff value of 194.40 pg/mL (p = 0.001). Day 1 CRP correlated with ISS on admission, and on day 5 it correlated with SOFA score 5, while lactate correlated with length of stay on days 1, 5, and 7, and its levels were significantly higher in non-survivors on days 5 and 7. cfDNA is a good predictor of patient outcome in ICU and to a lesser extent as a marker of sepsis. PCT is another promising marker that can complement cfDNA to reach better patient management. Other markers can help in less severe cases.

Headspace Analysis of Ammonium Nitrate

DTIC Science & Technology

2017-01-25

to an Agilent 7890 gas chromatograph (GC) (Agilent Technologies, Santa Clara, CA). Methane CI was used to optimize instrument parameters, which...order of 0.1 mTorr, as were CF2Cl2, CF3Cl, methane , and isobutane. Figure 2. Analyte sorbent tube mounted and interfaced with a modified GC...observed at no more than 22% abundance of m/z 17. When larger gases such as methane were mixed in significant proportion with 500 ppm carbon

Sensitivity and specificity of different methods for cystic fibrosis-related diabetes screening: is the oral glucose tolerance test still the standard?

PubMed

Mainguy, Catherine; Bellon, Gabriel; Delaup, Véronique; Ginoux, Tiphanie; Kassai-Koupai, Behrouz; Mazur, Stéphane; Rabilloud, Muriel; Remontet, Laurent; Reix, Philippe

2017-01-01

Cystic fibrosis-related diabetes (CFRD) is a late cystic fibrosis (CF)-associated comorbidity whose prevalence is increasing sharply lifelong. Guidelines for glucose metabolism (GM) monitoring rely on the oral glucose tolerance test (OGTT). However, this test is neither sensitive nor specific. The aim of this study was to compare sensitivity and specificity of different methods for GM monitoring in children and adolescents with CF. Continuous glucose monitoring system (CGMS), used as the reference method, was compared with the OGTT, intravenous glucose tolerance test (IGTT), homeostasis model assessment index of insulin resistance (HOMA-IR), homeostasis model assessment index of β-cell function (HOMA-%B) and glycated haemoglobin A1C. Patients were classified into three groups according to CGMS: normal glucose tolerance (NGT), impaired glucose tolerance (IGT) and diabetes mellitus (DM). Twenty-nine patients (median age: 13.1 years) were recruited. According to CGMS, 11 had DM, 12 IGT and six NGT, whereas OGTT identified three patients with DM and five with IGT. While 13 of 27 had insulin deficiency according to IGTT, there was 19 of 28 according to HOMA-%B. According to HOMA-IR, 12 of 28 had insulin resistance. HOMA-%B was the most sensitive method for CFRD screening [sensitivity 91% (95% CI), specificity 47% (95% CI) and negative predictive value 89% (95% CI)]. OGTT showed the weak capacity to diagnose DM in CF and should no longer be considered as the reference method for CFRD screening in patients with CF. In our study, HOMA-%B showed promising metrics for CFRD screening. Finally, CGMS revealed that pathological glucose excursions were frequent even early in life.

Prognostic Implications of Multiplex Detection of KRAS Mutations in Cell-Free DNA from Patients with Pancreatic Ductal Adenocarcinoma.

PubMed

Kim, Min Kyeong; Woo, Sang Myung; Park, Boram; Yoon, Kyong-Ah; Kim, Yun-Hee; Joo, Jungnam; Lee, Woo Jin; Han, Sung-Sik; Park, Sang-Jae; Kong, Sun-Young

2018-04-01

Cell-free DNA (cfDNA) is known to provide potential biomarkers for predicting clinical outcome, but its value in pancreatic ductal adenocarcinoma (PDAC) has not been fully evaluated. The aim of this study was to evaluate the clinical applicability of quantitative analysis of multiplex KRAS mutations in cell-free DNA from patients with PDAC. A total of 106 patients with PDAC were enrolled in this prospective study. The concentration and fraction of KRAS mutations were determined through multiplex detection of KRAS mutations in plasma samples by use of a droplet digital PCR kit (Bio-Rad). KRAS mutations were detected in 96.1% of tissue samples. Eighty patients (80.5%) harbored KRAS mutations in cfDNA, with a median KRAS mutation concentration of 0.165 copies/μL and a median fractional abundance of 0.415%. Multivariable analyses demonstrated that the KRAS mutation concentration [hazard ratio (HR), 2.08; 95% CI, 1.20-3.63] and KRAS fraction (HR, 1.73; 95% CI, 1.02-2.95) were significant factors for progression-free survival. KRAS mutation concentration (HR, 1.97; 95% CI, 1.05-3.67) also had prognostic implications for overall survival. Subgroup analyses showed that KRAS mutation concentration and fractional abundance significantly affected progression-free survival in resectable PDAC ( P = 0.016). Moreover, when combined with the cancer biomarker CA19-9, the KRAS mutation concentration in cfDNA showed additive benefits for the prediction of overall survival. This study demonstrates that multiplex detection of KRAS mutations in plasma cfDNA is clinically relevant, providing a potential candidate biomarker for prognosis of PDAC. © 2018 American Association for Clinical Chemistry.

Comparison of catheter ablation for paroxysmal atrial fibrillation between cryoballoon and radiofrequency: a meta-analysis.

PubMed

Chen, Chao-Feng; Gao, Xiao-Fei; Duan, Xu; Chen, Bin; Liu, Xiao-Hua; Xu, Yi-Zhou

2017-04-01

The present systematic review and meta-analysis aimed to assess and compare the safety and efficacy of radiofrequency (RF) and cryoballoon (CB) ablation for paroxysmal atrial fibrillation (PAF). RF and CB ablation are two frequently used methods for pulmonary vein isolation in PAF, but which is a better choice for PAF remains uncertain. A systematic review was conducted in Medline, PubMed, Embase, and Cochrane Library. All trials comparing RF and CB ablation were screened and included if the inclusion criteria were met. A total of 38 eligible studies, 9 prospective randomized or randomized controlled trials (RCTs), and 29 non- RCTs were identified, adding up to 15,496 patients. Pool analyses indicated that CB ablation was more beneficial in terms of procedural time [standard mean difference = -0.58; 95% confidence interval (CI), -0.85 to -0.30], complications without phrenic nerve injury (PNI) [odds ratio (OR) = 0.79; 95% CI, 0.67-0.93; I 2  = 16%], and recrudescence (OR = 0.83; 95% CI, 0.70-0.97; I 2  = 63%) for PAF; however, the total complications of CB was higher than RF. The subgroup analysis found that, compared with non-contact force radiofrequency (non-CF-RF), both first-generation cryoballoon (CB1) and second-generation cryoballoon (CB2) ablation could reduce complications with PNI, procedural time, and recrudescence. However, the safety and efficacy of CB2 was similar to those of CF-RF. Available overall and subgroup data suggested that both CB1 and CB2 were more beneficial than RF ablation, and the main advantages were reflected in comparing them with non-CF-RF. However, CF-RF and CB2 showed similar clinical benefits.

Evaluation of the Aspergillus Western Blot IgG Kit for Diagnosis of Chronic Aspergillosis

PubMed Central

Oliva, A.; Flori, P.; Hennequin, C.; Dubus, J.-C.; Reynaud-Gaubert, M.; Charpin, D.; Vergnon, J. M.; Gay, P.; Colly, A.; Piarroux, R.; Pelloux, H.

2014-01-01

Immunoprecipitin detection (IPD) is the current reference confirmatory technique for anti-Aspergillus antibody detection; however, the lack of standardization is a critical drawback of this assay. In this study, we evaluated the performance of the Aspergillus Western blot (Asp-WB) IgG kit (LDBio Diagnostics, Lyon, France), a recently commercialized immunoblot assay for the diagnosis of various clinical presentations of chronic aspergillosis. Three hundred eight serum samples from 158 patients with aspergillosis sensu lato (s.l.) were analyzed. More specifically, 267 serum samples were derived from patients with Aspergillus disease, including 89 cases of chronic pulmonary aspergillosis, 10 of aspergilloma, and 32 of allergic bronchopulmonary aspergillosis, while 41 samples were from patients with Aspergillus colonization, including 15 cystic fibrosis (CF) and 12 non-CF patients. For blood donor controls, the Asp-WB specificity was 94%, while the kit displayed a sensitivity for the aspergillosis s.l. diagnosis of 88.6%, with a diagnostic odds ratio (DOR) of 119 (95% confidence interval [CI], 57 to 251). The DOR values were 185.22 (95% CI,78.79 to 435.45) and 43.74 (95% CI, 15.65 to 122.20) for the diagnosis of Aspergillus disease and Aspergillus colonization, respectively. Among the patients, the sensitivities of the Asp-WB in the diagnosis of Aspergillus colonization were 100% and 41.7% in CF and non-CF patients, respectively. The Asp-WB yielded fewer false-negative results than did IPD. In conclusion, the Asp-WB kit performed well for the diagnosis of various clinical presentations of aspergillosis in nonimmunocompromised patients, with an enhanced standardization and a higher sensitivity than with IPD, which is the current reference method. PMID:25392351

Evaluation of the Aspergillus Western blot IgG kit for diagnosis of chronic aspergillosis.

PubMed

Oliva, A; Flori, P; Hennequin, C; Dubus, J-C; Reynaud-Gaubert, M; Charpin, D; Vergnon, J M; Gay, P; Colly, A; Piarroux, R; Pelloux, H; Ranque, S

2015-01-01

Immunoprecipitin detection (IPD) is the current reference confirmatory technique for anti-Aspergillus antibody detection; however, the lack of standardization is a critical drawback of this assay. In this study, we evaluated the performance of the Aspergillus Western blot (Asp-WB) IgG kit (LDBio Diagnostics, Lyon, France), a recently commercialized immunoblot assay for the diagnosis of various clinical presentations of chronic aspergillosis. Three hundred eight serum samples from 158 patients with aspergillosis sensu lato (s.l.) were analyzed. More specifically, 267 serum samples were derived from patients with Aspergillus disease, including 89 cases of chronic pulmonary aspergillosis, 10 of aspergilloma, and 32 of allergic bronchopulmonary aspergillosis, while 41 samples were from patients with Aspergillus colonization, including 15 cystic fibrosis (CF) and 12 non-CF patients. For blood donor controls, the Asp-WB specificity was 94%, while the kit displayed a sensitivity for the aspergillosis s.l. diagnosis of 88.6%, with a diagnostic odds ratio (DOR) of 119 (95% confidence interval [CI], 57 to 251). The DOR values were 185.22 (95% CI,78.79 to 435.45) and 43.74 (95% CI, 15.65 to 122.20) for the diagnosis of Aspergillus disease and Aspergillus colonization, respectively. Among the patients, the sensitivities of the Asp-WB in the diagnosis of Aspergillus colonization were 100% and 41.7% in CF and non-CF patients, respectively. The Asp-WB yielded fewer false-negative results than did IPD. In conclusion, the Asp-WB kit performed well for the diagnosis of various clinical presentations of aspergillosis in nonimmunocompromised patients, with an enhanced standardization and a higher sensitivity than with IPD, which is the current reference method. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

Aspergillus infection in lung transplant patients: incidence and prognosis.

PubMed

Iversen, M; Burton, C M; Vand, S; Skovfoged, L; Carlsen, J; Milman, N; Andersen, C B; Rasmussen, M; Tvede, M

2007-12-01

Lung transplant recipients experience a particularly high incidence of Aspergillus infection in comparison with other solid-organ transplantations. This study was conducted to determine the incidence of Aspergillus colonisation and invasive aspergillosis, and the impact on long-term survival associated with Aspergillus infection. A retrospective study of 362 consecutive lung transplant patients from a single national centre who were transplanted 1992-2003 were studied. Twenty-seven patients were excluded due to incomplete or missing files. A total of 105/335 (31%) patients had evidence of Aspergillus infection (colonisation or invasion), including 83 (25%) patients with colonisation and 22 (6%) patients with radiographic or histological evidence of invasive disease. Most of the infections occurred within the first 3 months after transplantation. Cystic fibrosis (CF) patients had higher incidences of colonisation and invasive disease [15 (42%) and 4 (11%) of 36 patients] than non-CF patients [68 (23%) and 18 (6%) of 299 patients] (P = 0.01). Invasive aspergillosis was associated with 58% mortality after 2 years, whereas colonisation was not associated with early increased mortality but was associated with increased mortality after 5 years compared to non-infected patients (P < 0.05). An analysis of demographic factors showed that donor age [OR 1.40 per decade (95% CI 1.10-1.80)], ischaemia time [OR 1.17 per hour increase (95% CI 1.01-1.39)], and use of daclizumab versus polyclonal induction [OR 2.05 (95% CI 1.14-3.75)] were independent risk factors for Aspergillus infection. Invasive aspergillosis was associated with early and high mortality in lung transplant patients. Colonisation with Aspergillus was also associated with a significant increase in mortality after 5 years. CF patients have a higher incidence of Aspergillus infection than non-CF patients.

Association of pulse wave velocity and pulse pressure with decline in kidney function.

PubMed

Kim, Chang Seong; Kim, Ha Yeon; Kang, Yong Un; Choi, Joon Seok; Bae, Eun Hui; Ma, Seong Kwon; Kim, Soo Wan

2014-05-01

The association between arterial stiffness and decline in kidney function in patients with mild to moderate chronic kidney disease (CKD) is not well established. This study investigated whether pulse wave velocity (PWV) and pulse pressure (PP) are independently associated with glomerular filtration rate (GFR) and rapid decline in kidney function in early CKD. Carotid femoral PWV (cfPWV), brachial-ankle PWV (baPWV), and PP were measured in a cohort of 913 patients (mean age, 63±10 years; baseline estimated GFR, 84±18 mL/min/1.73 m(2) ). Estimated GFR was measured at baseline and at follow-up. The renal outcome examined was rapid decline in kidney function (estimated GFR loss, >3 mL/min/1.73 m(2) per year). The median follow-up duration was 3.2 years. Multivariable adjusted linear regression model indicated that arterial PWV (both cfPWV and baPWV) and PP increased as estimated GFR declined, but neither was associated with kidney function after adjustment for various covariates. Multivariable logistic regression analysis found that cfPWV and baPWV were not associated with rapid decline in kidney function (odds ratio [OR], 1.39, 95% confidence interval [CI], 0.41-4.65; OR, 2.51, 95% CI, 0.66-9.46, respectively), but PP was (OR, 1.22, 95% CI, 1.01-1.48; P=.045). Arterial stiffness assessed using cfPWV and baPWV was not correlated with lower estimated GFR and rapid decline in kidney function after adjustment for various confounders. Thus, PP is an independent risk factor for rapid decline in kidney function in populations with relatively preserved kidney function (estimated GFR ≥30 mL/min/1.73 m(2) ). ©2014 Wiley Periodicals, Inc.

Effects of Diagnosis by Newborn Screening for Cystic Fibrosis on Weight and Length in the First Year of Life

PubMed Central

Leung, Daniel H.; Heltshe, Sonya L.; Borowitz, Drucy; Gelfond, Daniel; Kloster, Margaret; Heubi, James E.; Stalvey, Michael; Ramsey, Bonnie W.

2017-01-01

IMPORTANCE Since the implementation of universal newborn screening (NBS) for cystic fibrosis (CF), the timing and magnitude of growth deficiency or its association with correlates of disease among infants with CF who underwent NBS has not been well described. OBJECTIVE To examine incremental weight gain, linear growth, and clinical features in the first year of life among infants with CF who underwent NBS. DESIGN, SETTING, AND PARTICIPANTS The Baby Observational and Nutrition Study (BONUS), a multicenter, longitudinal, observational cohort study, was conducted during regular CF clinic visits in the first 12 months of life at 28 US Cystic Fibrosis Foundation–accredited Care Centers from January 7, 2012, through May 31, 2015. Participants included 231 infants younger than 3.5 months who underwent NBS and had confirmed CF, with a gestational age of at least 35 weeks, birth weight of at least 2.5 kg, and toleration of full oral feeds. Of these, 222 infants (96.1%) had follow-up beyond 6 months of age and 215 (93.1%) completed 12 months of follow-up. EXPOSURE Cystic fibrosis. MAIN OUTCOME AND MEASURES Attained weight and length for age and World Health Organization normative z scores at ages 1 to 6 and 8, 10, and 12 months (defined a priori). RESULTS Of the 231 infants enrolled, 110 infants (47.6%) were female and 121 (52.4%) were male, with a mean (SD) age of 2.58 (0.69) months. BONUS infants had lower than mean birth weights (mean z score, −0.15; 95% CI, −0.27 to −0.04) and higher birth lengths (mean z score, 0.44; 95% CI, 0.26 to 0.62). They achieved normal weight by 12 months, a significant improvement over a prescreening cohort of newborns with CF from 20 years before the contemporary cohort (mean z score increase, 0.57; 95% CI, 0.37–0.77). However, length was lower than the mean at 12 months (mean z score, −0.56; 95% CI, −0.70 to −0.42). Only 30 infants (13.6%) were at less than the 10th percentile of weight for age, whereas 53 (23.9%) were at less than the 10th percentile of length for age at more than half their visits. Male sex, pancreatic insufficiency, meconium ileus, histamine blocker use, and respiratory Pseudomonas aeruginosa infection were associated with lower weight or length during the first year. Insulinlike growth factor 1 levels were significantly lower among low-length infants. Persistently low-weight infants consumed significantly more calories, and weight and length z scores were negatively correlated with caloric intake. CONCLUSIONS AND RELEVANCE Since initiation of universal NBS for CF, significant improvement has occurred in nutritional status, with normalization of weight in the first year of life. However, length stunting remains common. PMID:28437538

Transcriptional Activation of Mucin by Pseudomonas aeruginosa Lipopolysaccharide in the Pathogenesis of Cystic Fibrosis Lung Disease

NASA Astrophysics Data System (ADS)

Li, Jian-Dong; Dohrman, Austin F.; Gallup, Marianne; Miyata, Susumu; Gum, James R.; Kim, Young S.; Nadel, Jay A.; Prince, Alice; Basbaum, Carol B.

1997-02-01

An unresolved question in cystic fibrosis (CF) research is how mutations of the CF transmembrane conductance regulator, a CI ion channel, cause airway mucus obstruction leading to fatal lung disease. Recent evidence has linked the CF transmembrane conductance regulator mutation to the onset and persistence of Pseudomonas aeruginosa infection in the airways, and here we provide evidence directly linking P. aeruginosa infection to mucus overproduction. We show that P. aeruginosa lipopolysaccharide profoundly upregulates transcription of the mucin gene MUC 2 in epithelial cells via inducible enhancer elements and that this effect is blocked by the tyrosine kinase inhibitors genistein and tyrphostin AG 126. These findings improve our understanding of CF pathogenesis and suggest that the attenuation of mucin production by lipopolysaccharide antagonists and tyrosine kinase inhibitors could reduce morbidity and mortality in this disease.

First Demonstration of a Scintillating Xenon Bubble Chamber for Detecting Dark Matter and Coherent Elastic Neutrino-Nucleus Scattering

NASA Astrophysics Data System (ADS)

Baxter, D.; Chen, C. J.; Crisler, M.; Cwiok, T.; Dahl, C. E.; Grimsted, A.; Gupta, J.; Jin, M.; Puig, R.; Temples, D.; Zhang, J.

2017-06-01

A 30-g xenon bubble chamber, operated at Northwestern University in June and November 2016, has for the first time observed simultaneous bubble nucleation and scintillation by nuclear recoils in a superheated liquid. This chamber is instrumented with a CCD camera for near-IR bubble imaging, a solar-blind photomultiplier tube to detect 175-nm xenon scintillation light, and a piezoelectric acoustic transducer to detect the ultrasonic emission from a growing bubble. The time of nucleation determined from the acoustic signal is used to correlate specific scintillation pulses with bubble-nucleating events. We report on data from this chamber for thermodynamic "Seitz" thresholds from 4.2 to 15.0 keV. The observed single- and multiple-bubble rates when exposed to a Cf 252 neutron source indicate that, for an 8.3-keV thermodynamic threshold, the minimum nuclear recoil energy required to nucleate a bubble is 19 ±6 keV (1 σ uncertainty). This is consistent with the observed scintillation spectrum for bubble-nucleating events. We see no evidence for bubble nucleation by gamma rays at any of the thresholds studied, setting a 90% C.L. upper limit of 6.3 ×10-7 bubbles per gamma interaction at a 4.2-keV thermodynamic threshold. This indicates stronger gamma discrimination than in CF3 I bubble chambers, supporting the hypothesis that scintillation production suppresses bubble nucleation by electron recoils, while nuclear recoils nucleate bubbles as usual. These measurements establish the noble-liquid bubble chamber as a promising new technology for the detection of weakly interacting massive particle dark matter and coherent elastic neutrino-nucleus scattering.

First demonstration of a scintillating xenon bubble chamber for detecting dark matter and coherent elastic neutrino-nucleus scattering

DOE PAGES

Baxter, D.; Chen, C. J.; Crisler, M.; ...

2017-06-08

A 30-g xenon bubble chamber, operated at Northwestern University in June and November 2016, has for the first time observed simultaneous bubble nucleation and scintillation by nuclear recoils in a superheated liquid. This chamber is instrumented with a CCD camera for near-IR bubble imaging, a solar-blind photomultiplier tube to detect 175-nm xenon scintillation light, and a piezoelectric acoustic transducer to detect the ultrasonic emission from a growing bubble. The time of nucleation determined from the acoustic signal is used to correlate specific scintillation pulses with bubble-nucleating events. We report on data from this chamber for thermodynamic "Seitz" thresholds from 4.2 to 15.0 keV. The observed single- and multiple-bubble rates when exposed to amore » $$^{252}$$Cf neutron source indicate that, for an 8.3-keV thermodynamic threshold, the minimum nuclear recoil energy required to nucleate a bubble is $$19\\pm6$$ keV (1$$\\sigma$$ uncertainty). This is consistent with the observed scintillation spectrum for bubble-nucleating events. We see no evidence for bubble nucleation by gamma rays at any of the thresholds studied, setting a 90% C.L. upper limit of $$6.3\\times10^{-7}$$ bubbles per gamma interaction at a 4.2-keV thermodynamic threshold. This indicates stronger gamma discrimination than in CF$$_3$$I bubble chambers, supporting the hypothesis that scintillation production suppresses bubble nucleation by electron recoils while nuclear recoils nucleate bubbles as usual. Finally, these measurements establish the noble-liquid bubble chamber as a promising new technology for the detection of weakly interacting massive particle dark matter and coherent elastic neutrino-nucleus scattering.« less

Arterial stiffness is associated with depression in middle-aged men — the Maastricht Study

PubMed Central

Onete, Veronica; Henry, Ronald M.; Sep, Simone J.S.; Koster, Annemarie; van der Kallen, Carla J.; Dagnelie, Pieter C.; Schaper, Nicolaas; Köhler, Sebastian; Reesink, Koen; Stehouwer, Coen D.A.

2018-01-01

Background Arterial stiffening may underlie the association between depression and cardiovascular disease (CVD), but reported data are inconsistent. We investigated the associations between aortic stiffness and major depressive disorder (MDD) and depressive symptoms, and whether these differed by sex and age. Methods We measured carotid to femoral pulse wave velocity (cfPWV) using applanation tonometry, and we assessed depression using the Mini-International Neuropsychiatric Interview (MINI) and the Patient Health Questionnaire-9 (PHQ-9) in a cohort of participants from The Maastricht Study. Logistic and negative binominal models were adjusted for age, type 2 diabetes mellitus (T2DM), mean arterial pressure (MAP) and CVD risk factors. Results We included 2757 participants in our analyses (48.8% men, mean age 59.8 ± 8.1 yr, 27% T2DM). We found that cfPWV was associated with MDD in men (fully adjusted odds ratio [OR] 2.36, 95% confidence interval [CI] 1.45–3.84), but not in women (OR 1.57, 95% CI 0.93–2.66), aged 60 years or younger. The ORs were not significant in individuals older than 60 years (men: OR 1.03, 95% CI 0.63–1.68; women: OR 0.64, 95% CI 0.32–1.31). Similarly, cfPWV was associated with a higher PHQ-9 score in men (rate ratio 1.28, 95% CI 1.09–1.52), but not in women (rate ratio 1.11, 95% CI 0.99–1.23), aged 60 years or younger. Associations were not significant in individuals older than 60 years (men: rate ratio 0.96, 95% CI 0.84–1.08; women: rate ratio 1.00, 95% CI 0.90–1.12). Limitations We cannot rule out reversed causation in this cross-sectional study. Conclusion Greater aortic stiffness is associated with MDD and depressive symptoms among middle-aged men and to a lesser extent in women, whereas this association was not observed in old age. PMID:29481318

Organic Scintillator for Real-Time Neutron Dosimetry

DOE PAGES

Beyer, Kyle A.; Di Fulvio, Angela; Stolarczyk, Liliana; ...

2017-11-15

We have developed a radiation detector based on an organic scintillator for spectrometry and dosimetry of out-of-field secondary neutrons from clinical proton beams. The detector consists of an EJ-299-34 crystalline organic scintillator, coupled by fiber optic cable to a silicon photomultiplier (SiPM). Proof of concept measurements were taken with 137Cs and 252Cf, and corresponding simulations were performed in MCNPX-PoliMi. Despite its small size, the detector is able to discriminate between neutron and gamma-rays via pulse shape discrimination. We simulated the response function of the detector to monoenergetic neutrons in the 100 keV–0 MeV range using MCNPX-PoliMi. The measured unfolded 252Cfmore » neutron spectrum is in good agreement with the theoretical Watt fission spectrum. We determined the ambient dose equivalent by folding the spectrum with the fluence-to-ambient dose conversion coefficient, with a 1.4% deviation from theory. Some preliminary proton beam experiments were preformed at the Bronowice Cyclotron Center patient treatment facility using a clinically relevant proton pencil beam for brain tumor and craino-spinal treatment directed at a child phantom.« less

Organic Scintillator for Real-Time Neutron Dosimetry

DOE Office of Scientific and Technical Information (OSTI.GOV)

Beyer, Kyle A.; Di Fulvio, Angela; Stolarczyk, Liliana

We have developed a radiation detector based on an organic scintillator for spectrometry and dosimetry of out-of-field secondary neutrons from clinical proton beams. The detector consists of an EJ-299-34 crystalline organic scintillator, coupled by fiber optic cable to a silicon photomultiplier (SiPM). Proof of concept measurements were taken with 137Cs and 252Cf, and corresponding simulations were performed in MCNPX-PoliMi. Despite its small size, the detector is able to discriminate between neutron and gamma-rays via pulse shape discrimination. We simulated the response function of the detector to monoenergetic neutrons in the 100 keV–0 MeV range using MCNPX-PoliMi. The measured unfolded 252Cfmore » neutron spectrum is in good agreement with the theoretical Watt fission spectrum. We determined the ambient dose equivalent by folding the spectrum with the fluence-to-ambient dose conversion coefficient, with a 1.4% deviation from theory. Some preliminary proton beam experiments were preformed at the Bronowice Cyclotron Center patient treatment facility using a clinically relevant proton pencil beam for brain tumor and craino-spinal treatment directed at a child phantom.« less

Cystic Fibrosis Revisited - a Review Study.

PubMed

Klimova, Blanka; Kuca, Kamil; Novotny, Michal; Maresova, Petra

2017-01-01

Cystic fibrosis (CF) is an incurable, chronic disease, which causes severe damages to respiratory and digestive tracts. It is the most common genetically inherited disease among caucasians. This disease is caused by defects in CF genes, the so-called mutations in cystic fibrosis transmembrane conductance regulator (CFTR) gene population. At present over 100,000 people suffer from this disease worldwide. The purpose of this review study is to describe the pathophysiology of CF and provide the latest information on its diagnosis and treatment therapies with respect to the improvement of patient's quality of life and emphasis on targeted specialized care. The methodological approaches include a method of literature review of available sources exploring the issue of cystic fibrosis both from a global and specific perspective point of view. A search was performed in the databases PubMed, MEDLINE, Web of Science, Scopus, Springer and ScienceDirect. Furthermore, other sources cited in the analyzed studies were also examined. On the basis of evaluation of these literature sources, the research issue was explored. The main benefits (e.g., specialized centres for the treatment of CF exist or a new breakthrough in the gene therapy of CF has been made) and limitations (e.g., comorbidity of CF, lifelong and costly treatment, or adverse impact on patient's and caregiver's quality of life) in the treatment of narcolepsy are highlighted. CF requires an integrated treatment approach in specialized CF centers, involving various factors contributing to a better patient's state of health in the form of relevant and well-balanced non-pharmacological and pharmacological therapies. In addition, further large scale clinical trials are needed in order to develop compounds that are aimed at the most common classes of CFTR. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

CF.sub.4 laser

DOEpatents

Wittig, Curt; Tiee, Joe J.

1979-01-01

A CF.sub.4 laser for producing near 16 .mu.m radiation utilizing a line tunable CO.sub.2 laser as an optical pumping source. The device uses a cryogenically cooled optically pumped cell containing molecular CF.sub.4 gas. An optical resonant cavity formed around the optically pumped cell induces oscillations of near 16 .mu.m radiation from the .nu..sub.2 +.nu..sub.4 .fwdarw..nu..sub.2 transition in the molecular CF.sub.4 gas.

Inhaled mannitol improves lung function in cystic fibrosis.

PubMed

Jaques, Anna; Daviskas, Evangelia; Turton, James A; McKay, Karen; Cooper, Peter; Stirling, Robert G; Robertson, Colin F; Bye, Peter T P; LeSouëf, Peter N; Shadbolt, Bruce; Anderson, Sandra D; Charlton, Brett

2008-06-01

The airways in patients with cystic fibrosis (CF) are characterized by the accumulation of tenacious, dehydrated mucus that is a precursor for chronic infection, inflammation, and tissue destruction. The clearance of mucus is an integral component of daily therapy. Inhaled mannitol is an osmotic agent that increases the water content of the airway surface liquid, and improves the clearance of mucus with the potential to improve lung function and respiratory health. To this end, this study examined the efficacy and safety of therapy with inhaled mannitol over a 2-week period. This was a randomized, double-blind, placebo-controlled, crossover study. Thirty-nine subjects with mild-to-moderate CF lung disease inhaled 420 mg of mannitol or placebo twice daily for 2 weeks. Following a 2-week washout period, subjects were entered in the reciprocal treatment arm. Lung function, respiratory symptoms, quality of life, and safety were assessed. Mannitol treatment increased FEV(1) from baseline by a mean of 7.0% (95% confidence interval [CI], 3.3 to 10.7) compared to placebo 0.3% (95% CI, - 3.4 to 4.0; p < 0.001). The absolute improvement with mannitol therapy was 121 mL (95% CI, 56.3 to 185.7), which was significantly more than that with placebo (0 mL; 95% CI, - 64.7 to 64.7). The forced expiratory flow in the middle half of the FVC increased by 15.5% (95% CI, - 6.5 to 24.6) compared to that with placebo (increase, 0.7%; 95% CI, - 8.3 to 9.7; p < 0.02). The safety profile of mannitol was adequate, and no serious adverse events related to treatment were observed. Inhaled mannitol treatment over a period of 2 weeks significantly improved lung function in patients with CF. Mannitol therapy was safe and well tolerated. (ClinicalTrials.gov) Identifier: NCT00455130.

The density of tobacco retailers and its association with attitudes toward smoking, exposure to point-of-sale tobacco advertising, cigarette purchasing, and smoking among New York youth.

PubMed

Loomis, Brett R; Kim, Annice E; Busey, Andrew H; Farrelly, Matthew C; Willett, Jeffrey G; Juster, Harlan R

2012-11-01

Estimate the association between the density of licensed tobacco retailers (LTRs) and smoking-related attitudes and behaviors among middle and high school students in New York. The 2000-2008 New York Youth Tobacco Surveys were pooled (N=70,427) and linked with county-level density of LTRs and retailer compliance with laws restricting youth access to cigarettes. Logistic regressions tested for associations with attitudes toward smoking exposure to point-of-sale tobacco advertising, cigarette purchasing, and smoking prevalence. LTR density is associated with self-reported exposure to point-of-sale advertising in New York City (NYC) among all youth (OR=1.15; 95% CI: 1.02, 1.30) and nonsmokers (OR=1.14; 95% CI: 1.01, 1.30); youth believing that smoking makes them look cool, overall (OR=1.75; 95% CI: 1.22, 2.52) and among nonsmokers (OR=1.68; 95% CI: 1.11, 2.55); and a counter-intuitive negative relationship with frequent smoking in NYC (OR=0.50; 95% CI: 0.29, 0.84). Retailer compliance was negatively associated with youth reporting that a retail store is their usual source for cigarettes (OR=0.93; 95% CI: 0.88, 0.98). Restricting tobacco licenses and enforcing youth access laws are reasonable policy approaches for influencing youth smoking outcomes. Copyright © 2012 Elsevier Inc. All rights reserved.

Weld Development for Aluminum Fission Chamber

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cross, Carl Edward; Martinez, Jesse Norris

2017-05-16

The Sigma welding team was approached to help fabricate a small fission chamber (roughly ½ inch dia. x ½ inch tall cylinder). These chambers are used as radiation sensors that contain small traces of radionuclides (Cf 252, U 235, and U 238) that serve to ionize gas atoms in addition to external radiation. When a voltage is applied within the chamber, the resulting ion flow can be calibrated and monitored. Aluminum has the advantage of not forming radioactive compounds when exposed to high external radiation (except from minor Na alloy content). Since aluminum has not been used before in thismore » application, this presented an unexplored challenge.« less

Characterization of a 6Li-loaded liquid organic scintillator for fast neutron spectrometry and thermal neutron detection.

PubMed

Bass, C D; Beise, E J; Breuer, H; Heimbach, C R; Langford, T J; Nico, J S

2013-07-01

The characterization of a liquid scintillator incorporating an aqueous solution of enriched lithium chloride to produce a scintillator with 0.40% (6)Li is presented, including the performance of the scintillator in terms of its optical properties and neutron response. The scintillator was incorporated into a fast neutron spectrometer, and the light output spectra from 2.5 MeV, 14.1 MeV, and (252)Cf neutrons were measured using capture-gated coincidence techniques. The spectrometer was operated without coincidence to perform thermal neutron measurements. Possible improvements in spectrometer performance are discussed. Published by Elsevier Ltd.

Characterization of a 6Li enriched Cs2LiYCl6:Ce scintillator and its application as a γ-ray detector

NASA Astrophysics Data System (ADS)

Qin, Jianguo; Lai, Caifeng; Lu, Xinxin; Zheng, Pu; Zhu, Tonghua; Liu, Rong; Ye, Bangjiao; Zhang, Xinwei

2018-04-01

In this work, we characterize the γ-ray response and efficiency for a cylindrical inorganic Cs2LiYCl6:Ce detector 1‧‧ in diameter and 1‧‧ in height. The energy resolution and linearity are obtained from 21 γ-rays with energies ranging from 0.026 to 2.447 MeV. In addition, the neutron γ-ray discrimination is validated by measuring a 252Cf radioisotope. Gamma-ray response functions and matrix below 7 MeV are simulated using a Monte Carlo approach and validated through the unfolded γ-ray spectra.

Effect of alginate and inulin on intestinal microbial ecology of weanling pigs reared under different husbandry conditions.

PubMed

Janczyk, Pawel; Pieper, Robert; Smidt, Hauke; Souffrant, Wolfgang B

2010-04-01

The effects of inulin and alginate on intestinal microbial ecophysiology were investigated in piglets fed a diet (C) with 0.1% alginate (C+A) or 1.5% inulin (C+I) from weaning at day 28. The experiment was performed at an experimental farm (EF) and a commercial farm (CF). Digesta was collected from the ileum, caecum and colon of four piglets from each group on days 29, 30, 33 and 39. The metabolite concentrations changed with age. Colonic and caecal metabolites were affected by prebiotic treatment. Changes in microbiota composition were assessed by cultivation and denaturing gradient gel electrophoresis (DGGE) of 16S rRNA gene fragments. Enterococci increased in C+A at EF and decreased in C+I at both farms. Lactobacilli decreased in all segments in the experimental groups on days 30 and 33. Yeasts in C+I were five times lower at CF than at EF on day 39. The richness and diversity of DGGE profiles increased in the experimental groups. The evenness of colon digesta-derived DGGE profiles was higher in the experimental groups than in C and this situation was reversed in the distal small intestine. Multivariate redundancy analysis confirmed the recorded effects. In summary, both prebiotics affected the intestinal microbiota, and the changes were more pronounced at the CF.

Early diagnosis from newborn screening maximises survival in severe cystic fibrosis.

PubMed

Tridello, Gloria; Castellani, Carlo; Meneghelli, Ilaria; Tamanini, Anna; Assael, Baroukh M

2018-04-01

Newborn screening (NBS) for cystic fibrosis (CF) has been gradually established in several countries, but scant data are available on its long-term effects on survival. Our objective was to evaluate the long-term effects of CF NBS on survival. 586 patients, diagnosed and followed between 1971 and 2014 at the Verona CF Centre were analysed. Eligibility was confirmed in 342 cases diagnosed by NBS, 101 with meconium ileus and 143 through symptoms (44 out of 143 were NBS false negatives). The primary end-point was the 30-year overall survival in patients diagnosed by NBS. Patients were grouped according to the number of hospitalisations for respiratory or nutritional symptoms in the first 3 years of life: 0 (mild), 1-2 (moderate) and ≥3 (severe). Survival in NBS and symptoms groups was compared. The 30-year survival probability of the NBS group was 80.1% (95% CI 71.4-86.4%); in the symptoms group it was 71.0% (95% CI 62.2-78.2%). The 20-year survival was significantly higher in the NBS versus symptoms group in the severe (85% versus 64%, p=0.007) and moderate (94% versus 86%, p=0.016) groups. An adjusted Cox-model estimation confirmed differences in both the groups. Poor outcome associated with early severe presentation of CF is tempered by NBS.

No survival benefit to gaining private health insurance coverage for post-lung transplant care in adults with cystic fibrosis.

PubMed

Tumin, Dmitry; Foraker, Randi E; Tobias, Joseph D; Hayes, Don

2016-03-01

The use of public insurance is associated with diminished survival in patients with cystic fibrosis (CF) following lung transplantation. No data exist on benefits of gaining private health insurance for post-transplant care among such patients previously using public insurance. The United Network for Organ Sharing database was used to identify first-time lung transplant recipients participating in Medicare or Medicaid, diagnosed with CF, and transplanted between 2005 and 2015. Survival outcomes were compared between recipients gaining private insurance after transplantation and those maintaining public coverage throughout follow-up. Since implementation of the lung allocation score, 575 adults with CF received lung transplantation funded by Medicare or Medicaid and contributed data on insurance status post-transplant. There were 128 (22%) patients who gained private insurance. Multivariable analysis of time-varying insurance status found no survival benefit of gaining private insurance (HR = 0.822; 95% CI = 0.525, 1.286; p = 0.390). Further analysis demonstrated that resuming public insurance coverage was detrimental, relative to gaining and keeping private insurance (HR = 2.315; 95% CI = 1.020, 5.258; p = 0.045). Survival disadvantages of lung transplant recipients with CF who have public health insurance were not ameliorated by a switch to private coverage for post-transplant care. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Long-term outcomes of late course accelerated hyper-fractionated radiotherapy for localized esophageal carcinoma in Mainland China: a meta-analysis.

PubMed

Zhang, Y W; Chen, L; Bai, Y; Zheng, X

2011-09-01

Published data on the long-term survival results of patients with localized esophageal carcinoma receiving late course accelerated hyper-fractionated radiotherapy (LCAF RT) versus conventional fractionated radiotherapy (CF RT) are inconclusive. In order to derive a more precise estimation of the both treatment-regimes, a meta-analysis based on systematic review of published articles was performed. A meta-analysis was performed using trials identified through Pubmed and Chinese national knowledge infrastructure. Results in 5-year survival and 5-year local control were collected from randomized trials comparing LCAF RT with CF RT. Review Manager (The Cochrane Collaboration, Oxford, England) and Stata software (Stata Corporation, College Station, TX, USA) were used for data management. A total of 11 trials were involved in this analysis with 572 cases and 567 controls. Our results showed that LCAF RT, compared with CF RT, significantly improved the 5-year survival (odds ratio [OR]= 2.93, 95% confidence interval [CI]: 2.15-4.00, P < 0.00001) and 5-year local control (OR = 3.96, 95% CI: 2.91-5.38, P < 0.00001). LCAF RT was more therapeutically beneficial than CF RT in the localized esophageal carcinoma. © 2011 Copyright the Authors. Journal compilation © 2011, Wiley Periodicals, Inc. and the International Society for Diseases of the Esophagus.

Untangling the transmission dynamics of primary and secondary vectors of Trypanosoma cruzi in Colombia: parasite infection, feeding sources and discrete typing units.

PubMed

Hernández, Carolina; Salazar, Camilo; Brochero, Helena; Teherán, Aníbal; Buitrago, Luz Stella; Vera, Mauricio; Soto, Hugo; Florez-Rivadeneira, Zulibeth; Ardila, Sussane; Parra-Henao, Gabriel; Ramírez, Juan David

2016-12-01

Trypanosoma cruzi is the causative agent of Chagas disease. Due to its genetic diversity has been classified into six Discrete Typing Units (DTUs) in association with transmission cycles. In Colombia, natural T. cruzi infection has been detected in 15 triatomine species. There is scarce information regarding the infection rates, DTUs and feeding preferences of secondary vectors. Therefore, the aim of this study was to determine T. cruzi infection rates, parasite DTU, ecotopes, insect stages, geographical location and bug feeding preferences across six different triatomine species. A total of 245 insects were collected in seven departments of Colombia. We conducted molecular detection and genotyping of T. cruzi with subsequent identification of food sources. The frequency of infection, DTUs, TcI genotypes and feeding sources were plotted across the six species studied. A logistic regression model risk was estimated with insects positive for T. cruzi according to demographic and eco-epidemiological characteristics. We collected 85 specimens of Panstrongylus geniculatus, 77 Rhodnius prolixus, 37 R. pallescens, 34 Triatoma maculata, 8 R. pictipes and 4 T. dimidiata. The overall T. cruzi infection rate was 61.2% and presented statistical associations with the departments Meta (OR: 2.65; 95% CI: 1.69-4.17) and Guajira (OR: 2.13; 95% CI: 1.16-3.94); peridomestic ecotope (OR: 2.52: 95% CI: 1.62-3.93); the vector species P. geniculatus (OR: 2.40; 95% CI: 1.51-3.82) and T. maculata (OR: 2.09; 95% CI: 1.02-4.29); females (OR: 2.05; 95% CI: 1.39-3.04) and feeding on opossum (OR: 3.15; 95% CI: 1.85-11.69) and human blood (OR: 1.55; 95% CI: 1.07-2.24). Regarding the DTUs, we observed TcI (67.3%), TcII (6.7%), TcIII (8.7%), TcIV (4.0%) and TcV (6.0%). Across the samples typed as TcI, we detected TcIDom (19%) and sylvatic TcI (75%). The frequencies of feeding sources were 59.4% (human blood); 11.2% (hen); 9.6% (bat); 5.6% (opossum); 5.1% (mouse); 4.1% (dog); 3.0% (rodent); 1.0% (armadillo); and 1.0% (cow). New scenarios of T. cruzi transmission caused by secondary and sylvatic vectors are considered. The findings of sylvatic DTUs from bugs collected in domestic and peridomestic ecotopes confirms the emerging transmission scenarios in Colombia.

Branching ratios of α-decay to ground and excited states of Fm, Cf, Cm and Pu

NASA Astrophysics Data System (ADS)

Hassanabadi, H.; Hosseini, S. S.

2018-06-01

We use the well-known Wentzel-Kramers-Brillouin (WKB) barrier penetration probability to calculate α-decay branching ratios for ground and excited states of heavy even-even nuclei of Fermium (248-254Fm), Californium (244-252Cf), Curium (238-248Cm) and Plutonium (234-244Pu) with 94 ≤Zp ≤100. We obtained the branching ratios for the excited states of daughter nucleus by the α-decay energy (Qα), the angular momentum of α-particle (ℓα), and the excitation probability of the daughter nucleus with the excitation energy of state ℓ in the daughter nucleus (i.e. Eℓ*). α-Decay half-lives have been evaluated by using the proximity potential model for the heavy even-even nuclei. We have reported the half-lives and compared the results with the experimental data. The theoretical branching ratios of α-transitions in our calculation are found to agree with the available experimental data well for 0+→ 0+, 0+→ 2+, 0+→ 4+, 0+→ 6+ and 0+ → 8+α-transitions.

Solution-Grown Rubrene Crystals as Radiation Detecting Devices

DOE PAGES

Carman, Leslie; Martinez, H. Paul; Voss, Lars; ...

2017-01-11

There has been increased interest in organic semiconductors over the last decade because of their unique properties. Of these, 5, 6, 11, 12-tetraphenylnaphthacene (rubrene) has generated the most interest because of its high charge carrier mobility. In this paper, large single crystals with a volume of ~1 cm 3 were grown from solution by a temperature reduction technique. The faceted crystals had flat surfaces and cm-scale, visually defect-free areas suitable for physical characterization. X-ray diffraction analysis indicates that solvent does not incorporate into the crystals and photoluminescence spectra are consistent with pristine, high-crystallinity rubrene. Furthermore, the response curve to pulsedmore » optical illumination indicates that the solution grown crystals are of similar quality to those grown by physical vapor transport, albeit larger. The good quality of these crystals in combination with the improvement of electrical contacts by application of conductive polymer on the graphite electrodes have led to the clear observation of alpha particles with these rubrene detectors. Finally, preliminary results with a 252Cf source generate a small signal with the rubrene detector and may demonstrate that rubrene can also be used for detecting high-energy neutrons.« less

NSDann2BS, a neutron spectrum unfolding code based on neural networks technology and two bonner spheres

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ortiz-Rodriguez, J. M.; Reyes Alfaro, A.; Reyes Haro, A.

In this work a neutron spectrum unfolding code, based on artificial intelligence technology is presented. The code called ''Neutron Spectrometry and Dosimetry with Artificial Neural Networks and two Bonner spheres'', (NSDann2BS), was designed in a graphical user interface under the LabVIEW programming environment. The main features of this code are to use an embedded artificial neural network architecture optimized with the ''Robust design of artificial neural networks methodology'' and to use two Bonner spheres as the only piece of information. In order to build the code here presented, once the net topology was optimized and properly trained, knowledge stored atmore » synaptic weights was extracted and using a graphical framework build on the LabVIEW programming environment, the NSDann2BS code was designed. This code is friendly, intuitive and easy to use for the end user. The code is freely available upon request to authors. To demonstrate the use of the neural net embedded in the NSDann2BS code, the rate counts of {sup 252}Cf, {sup 241}AmBe and {sup 239}PuBe neutron sources measured with a Bonner spheres system.« less

Update of the α - n Yields for Reactor Fuel Materials for the Interest of Nuclear Safeguards

NASA Astrophysics Data System (ADS)

Simakov, S. P.; van den Berg, Q. Y.

2017-01-01

The neutron yields caused by spontaneous α-decay of actinides and subsequent (α,xn) reactions were re-evaluated for the reactor fuel materials UO2, UF6, PuO2 and PuF4. For this purpose, the most recent reference data for decay parameters, α-particle stopping powers and (α,xn) cross sections were collected, analysed and used in calculations. The input data and elaborated code were validated against available thick target neutron yields in pure and compound materials measured at accelerators or with radioactive sources. This paper provides the specific neutron yields and their uncertainties resultant from α-decay of actinides 241Am, 249Bk, 252Cf, 242,244Cm, 237Np, 238-242Pu, 232Th and 232-236,238U in oxide and fluoride compounds. The obtained results are an update of previous reference tables issued by the Los Alamos National Laboratory in 1991 which were used for the safeguarding of radioactive materials by passive non-destructive techniques. The comparison of the updated values with previous ones shows an agreement within one estimated uncertainty (≈ 10%) for oxides, and deviations of up to 50% for fluorides.

Recent applications of nuclear track emulsion technique

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zarubin, P. I., E-mail: zarubin@lhe.jinr.ru

A survey of recent results obtained using the nuclear track emulsion (NTE) technique in low energy applications is given. NTE irradiation with 60 MeV {sup 8}He nuclei provides identification of their decays at stopping, evaluation of the possibility of α range spectrometry, and observation of drift of thermalized {sup 8}He atoms. Correlations of α particles studied in {sup 12}C → 3α splitting induced by 14.1 MeV neutrons indicate the presence of a superposition of 0{sup +} and 2{sup +} states of the {sup 8}Be nucleus in the ground state of {sup 12}C. Angular correlations of fragments are studied in boron-enrichedmore » NTE, and the prospects of NTE application in radioactivity and nuclear fission research are discussed. It is proposed to use an automated microscope to search for collinear tripartition of heavy nuclei implanted in NTE. Surface irradiation of NTE by a {sup 252}Cf source is started. Planar events containing fragment pairs and long range α particles, as well as fragment triples, are studied. NTE samples are calibrated using Kr and Xe ions with an energy of 1.2 and 3 A MeV.« less

Registration of alpha particles in Makrofol-E nuclear track detectors

NASA Astrophysics Data System (ADS)

Rammah, Y. S.; Abdalla, Ayman M.; Ashraf, O.; Ashry, A. H.

2016-06-01

Fast detection of alpha particles in the range from 1 to 5 MeV in Makrofol-E polycarbonate nuclear track detectors (PCTDs) using a new chemical etchant was investigated. 252Cf and 241Am-thin open sources were used for irradiating Makrofol-E detectors with fission fragments and alpha particles in air at normal pressure and temperature (NPT). A chain of experimental work has been carried out using new etchants to register alpha particle in short time in Makrofol-E polycarbonate detectors. The etching efficiency were exhibited a clear dependence on the amount of methanol in the etching solution and etching time. The optimized chemical condition obtained at this stage of development for 200 μm Makrofol-E detectors are (8 ml of 10 N NaOH + 2 ml CH3OH) etching solutions at 60 °C for 3 h. In this study; it is possible to observe energy detection windows for Makrofol-E detectors according to applied etching duration. Makrofol-E introduced the characteristic Bragg peak, which indicates the advantages of this detector as alpha spectrometer. Consequently, the suggested new etchant can be developed for heavy ions detection and monitoring radon levels and its daughters.

NSDann2BS, a neutron spectrum unfolding code based on neural networks technology and two bonner spheres

NASA Astrophysics Data System (ADS)

Ortiz-Rodríguez, J. M.; Reyes Alfaro, A.; Reyes Haro, A.; Solís Sánches, L. O.; Miranda, R. Castañeda; Cervantes Viramontes, J. M.; Vega-Carrillo, H. R.

2013-07-01

In this work a neutron spectrum unfolding code, based on artificial intelligence technology is presented. The code called "Neutron Spectrometry and Dosimetry with Artificial Neural Networks and two Bonner spheres", (NSDann2BS), was designed in a graphical user interface under the LabVIEW programming environment. The main features of this code are to use an embedded artificial neural network architecture optimized with the "Robust design of artificial neural networks methodology" and to use two Bonner spheres as the only piece of information. In order to build the code here presented, once the net topology was optimized and properly trained, knowledge stored at synaptic weights was extracted and using a graphical framework build on the LabVIEW programming environment, the NSDann2BS code was designed. This code is friendly, intuitive and easy to use for the end user. The code is freely available upon request to authors. To demonstrate the use of the neural net embedded in the NSDann2BS code, the rate counts of 252Cf, 241AmBe and 239PuBe neutron sources measured with a Bonner spheres system.

High ambient temperature and risk of intestinal obstruction in cystic fibrosis.

PubMed

Ooi, Chee Y; Jeyaruban, Christina; Lau, Jasmine; Katz, Tamarah; Matson, Angela; Bell, Scott C; Adams, Susan E; Krishnan, Usha

2016-04-01

Distal intestinal obstruction syndrome (DIOS) and constipation in cystic fibrosis (CF) are conditions associated with impaction and/or obstruction by abnormally viscid mucofaecal material within the intestinal lumen. Dehydration has been proposed as a risk factor for DIOS and constipation in CF. The study primarily aimed to determine whether warmer ambient temperature and lower rainfall are risk factors for DIOS and constipation in CF. Hospitalisations for DIOS (incomplete or complete) and/or constipation were retrospectively identified (2000-2012). Genotype, phenotype, temperatures and rainfall data (for the week preceding and season of hospitalisation) were collected. Twenty-seven DIOS (59.3% incomplete; 40.7% complete) and 44 constipation admissions were identified. All admitted patients were pancreatic insufficient. Meconium ileus was significantly more likely in DIOS than constipation (64.7% vs. 33.3%; P = 0.038) and in complete than incomplete DIOS (100% vs. 57.1%; P = 0.04). The maximum temperature of the week before DIOS admission (mean (standard deviation) = 28.0 (5.8) °C) was significantly higher than the maximum temperature of the season of admission (25.2 (3.4) °C; P = 0.002). Similarly, the maximum temperature of the week before hospitalisation for constipation (mean (standard deviation) = 27.9 (6.3) °C) was significantly warmer compared with the season of admission (24.0 (4.1) °C; P < 0.0001). There were no significant differences between levels of rainfall during the week before hospitalisation and the season of admission for both DIOS and constipation. Relatively high ambient temperature may play a role in the pathogenesis of DIOS and constipation in CF. © 2016 The Authors Journal of Paediatrics and Child Health © 2016 Paediatrics and Child Health Division (Royal Australasian College of Physicians).

Continuous alternating inhaled antibiotic therapy in CF: A single center retrospective analysis.

PubMed

Van de Kerkhove, C; Goeminne, P C; Kicinski, M; Nawrot, T S; Lorent, N; Van Bleyenbergh, P; De Boeck, K; Dupont, L J

2016-11-01

The efficacy of inhaled antibiotics to treat chronic Pseudomonas aeruginosa pulmonary infection in patients with cystic fibrosis (CF) has been well established. Few data are available on the value of continuous alternating inhaled antibiotic therapy (CAIT), a strategy increasingly used in the management of CF. To investigate the effect of CAIT on clinical outcome in adult CF patients treated at the University Hospital Leuven. Patients with a documented CF diagnosis who received inhaled antibiotics between March 2010 and January 2015 were retrospectively evaluated. In patients receiving CAIT patient characteristics, recorded spirometry data and number of IV antibiotic days were collected retrospectively at fixed time intervals, from 6months before to one year after the start of the 2nd inhaled antibiotic. For patients on inhaled antibiotic monotherapy (IAMT), the same data were obtained at similar intervals during the study period. A total of 49 of 89 patients using chronic inhaled antibiotic therapy received CAIT. Patients receiving CAIT had a lower baseline FEV 1 and were more likely to be homozygous for F508del compared to patients receiving IAMT. FEV 1 deteriorated on average by a factor of 0.904 per year (95% CI: 0.851-0.960) prior to the start of CAIT. The initiation of CAIT was associated with an average improvement in FEV 1 by a factor of 1.148 per year (95% CI: 1.068-1.236, p=0.0002). The analysis of specific types of antibiotics revealed evidence of positive effects of adding COLI to TOBI and COLI to AZLI. We found no effect of the initiation of CAIT on the number of IV antibiotic days (p=0.80). CF patients with more advanced lung disease are more likely to receive CAIT. In this patient group, CAIT was associated with a significant improvement in FEV 1 . Further data are warranted to identify the value of CAIT. Copyright © 2016 European Cystic Fibrosis Society. Published by Elsevier B.V. All rights reserved.

Finding Motivation: Online Information Seeking Following Newborn Screening for Cystic Fibrosis.

PubMed

Strekalova, Yulia A

2016-07-01

Cystic fibrosis (CF) is a genetic disease that has no manifestations for carriers but is terminal for those diagnosed with it. CF is identified through newborn screening (NBS) tests, and most families have no knowledge about CF before their contact with a NBS program. Acknowledging the Internet as a popular health information source, this study examined information exchange about CF in online community forums. This article, guided by self-determination theory, aimed at providing understanding of psychological needs and motivation for health information seeking and active communication about CF. Through online communication with other families who share similar experience, caregivers of newborns diagnosed with CF sought and received support for their competence, autonomy, and relatedness needs during the initial CF testing and diagnosis reconciliation process. Online communities play an important role in the information seeking related to CF diagnosis and could become active partners in strategic knowledge dissemination efforts. © The Author(s) 2015.

Synthesis of Diketopiperizine Peptide Derivatives by Cross-Metathesis

DTIC Science & Technology

2006-05-01

3079, 2914, 1656, 1487, 1441, 1415, 1336, 1294, 1193, 1142, 1074, 1011 cm’ ; HRMS (EI pos) for CjoH14N20 2 [M]+: calcd 194.1055, found 194.1047. Anal...3088, 2971, 1705, 1509, 1455, 1368, 1169, 1053; HRMS (CI pos) for C 17 H 2 4NO4 [M+H]+: calcd 306.1705, found 306.1703. Anal. calcd 12 for C 17H 23NO4...28.47, 18.81; IR (neat) 3368, 2980, 2937, 1716, 1650, 1518, 1455, 1367, 1251, 1167, 1069; HRMS (ESI-FTICR) for [M+Na]+, calcd 252.1206, found 252.1227

Dating groundwater with trifluoromethyl sulfurpentafluoride (SF 5CF3), sulfur hexafluoride (SF6), CF 3Cl (CFC-13), and CF2Cl2 (CFC-12)

USGS Publications Warehouse

Busenberg, E.; Plummer, Niel

2008-01-01

[1] A new groundwater dating procedure using the transient atmospheric signal of the environmental tracers SF5CF3, CFC-13, SF6, and CFC-12 was developed. The analytical procedure determines concentrations of the four tracers in air and water samples. SF 5CF3 and CFC-13 can be used to date groundwaters in some environments where the CFCs and SF6 have previously failed because these new tracers have increasing atmospheric input functions, no known terrigenic source, and are believed to be stable under reducing conditions. SF5CF3 has a dating range from 1970 to modern; the mixing ratio (mole fraction) in North American air has increased from the detection limit of 0.005 parts per trillion (ppt) to the 2006 mole fraction of about 0.16 ppt. No evidence was found for degradation of SF5CF3 in laboratory anaerobic systems. The solubility of SF5CF3 was measured in water from 1 to 35??C. Groundwater samples that contained large amounts of terrigenic SF6 did not contain terrigenic SF 5CF3. CFC-13 is a trace atmospheric gas with a dating range in groundwater of about 1965 to modem. CFC-13 has been used primarily in very low-temperature refrigeration; thus groundwater environments are less likely to be contaminated with nonatmospheric sources as compared to other widely used CFCs. Because of the low solubility of SF5CF3 and CFC-13 in water, an excess air correction must be applied to the apparent ages. The new dating procedure was tested in water samples from wells and springs from Maryland, Virginia, and West Virginia.

Product toxicity and cometabolic competitive inhibition modeling of chloroform and trichloroethylene transformation by methanotrophic resting cells.

PubMed Central

Alvarez-Cohen, L; McCarty, P L

1991-01-01

The rate and capacity for chloroform (CF) and trichloroethylene (TCE) transformation by a mixed methanotrophic culture of resting cells (no exogenous energy source) and formate-fed cells were measured. As reported previously for TCE, formate addition resulted in an increased CF transformation rate (0.35 day-1 for resting cells and 1.5 day-1 for formate-fed cells) and transformation capacity (0.0065 mg of CF per mg of cells for resting cells and 0.015 mg of CF per mg of cells for formate-fed cells), suggesting that depletion of energy stores affects transformation behavior. The observed finite transformation capacity, even with an exogenous energy source, suggests that toxicity was also a factor. CF transformation capacity was significantly lower than that for TCE, suggesting a greater toxicity from CF transformation. The toxicity of CF, TCE, and their transformation products to whole cells was evaluated by comparing the formate oxidation activity of acetylene-treated cells to that of non-acetylene-treated cells with and without prior exposure to CF or TCE. Acetylene arrests the activity of methane monooxygenase in CF and TCE oxidation without halting cell activity toward formate. Significantly diminished formate oxidation by cells exposed to either CR or TCE without acetylene compared with that with acetylene suggests that the solvents themselves were not toxic under the experimental conditions but their transformation products were. The concurrent transformation of CF and TCE by resting cells was measured, and results were compared with predictions from a competitive-inhibition cometabolic transformation model. The reasonable fit between model predictions and experimental observations was supportive of model assumptions. PMID:1905516

Chronic Stenotrophomonas maltophilia infection and mortality or lung transplantation in cystic fibrosis patients.

PubMed

Waters, Valerie; Atenafu, Eshetu G; Lu, Annie; Yau, Yvonne; Tullis, Elizabeth; Ratjen, Felix

2013-09-01

Chronic Stenotrophomonas maltophilia infection is an independent risk factor for severe pulmonary exacerbations in cystic fibrosis (CF) patients. The goal of this study was to determine the effect of chronic S. maltophilia infection on mortality and the need for lung transplantation in a longitudinal study of children and adults with CF. This was a cohort study of CF patients from the Hospital for Sick Children and St Michael's Hospital (Toronto, Canada) from 1997 to 2008. A Cox Regression model was used to estimate the hazard ratio (HR) to time of death or lung transplantation adjusting for age, gender, genotype, pancreatic status, CF related diabetes (CFRD), forced expiratory volume in 1 s (FEV1), body mass index, number of pulmonary exacerbations, Pseudomonas aeruginosa, Burkholderia cepacia complex, Aspergillus and chronic S. maltophilia infection. A total of 687 patients were followed over the 12 year study period; 95 patients underwent a lung transplantation (of which 26 died) and an additional 49 patients died (total 144 events). In a Cox Regression model adjusting for baseline FEV1, baseline infection with B. cepacia complex (HR 1.72, 95% CI 1.09-2.71) and baseline chronic S. maltophilia infection (HR 2.80, 95% CI 1.65-4.76) were significantly associated with death or lung transplant. However, in a time-varying model, infection with B. cepacia complex and chronic S. maltophilia infection were no longer significant. Baseline chronic S. maltophilia infection is associated with an almost three-fold increased risk of death or lung transplant in CF patients. It is still unclear, however, whether chronic S. maltophilia infection is simply a marker of severity of disease and ultimate mortality or whether it is causally related to disease progression. Copyright © 2012 European Cystic Fibrosis Society. Published by Elsevier B.V. All rights reserved.

Improved air trapping evaluation in chest computed tomography in children with cystic fibrosis using real-time spirometric monitoring and biofeedback.

PubMed

Kongstad, Thomas; Buchvald, Frederik F; Green, Kent; Lindblad, Anders; Robinson, Terry E; Nielsen, Kim G

2013-12-01

The quality of chest Computed Tomography (CT) images in children is dependent upon a sufficient breath hold during CT scanning. This study evaluates the influence of spirometric breath hold monitoring with biofeedback software on inspiratory and expiratory chest CT lung density measures, and on trapped air (TA) scoring in children with cystic fibrosis (CF). This is important because TA is an important component of early and progressive CF lung disease. A cross sectional comparison study was completed for chest CT imaging in two cohorts of CF children with comparable disease severity, using spirometric breath hold monitoring and biofeedback software (Copenhagen (COP)) or unmonitored breath hold manoeuvres (Gothenburg (GOT)). Inspiratory-expiratory lung density differences were calculated, and TA was scored to assess the difference between the two cohorts. Eighty-four chest CTs were evaluated. Mean (95%CI) change in inspiratory-expiratory lung density differences was 436 Hounsfield Units (HU) (408 to 464) in the COP cohort with spirometric breath hold monitoring versus 229 HU (188 to 269) in the GOT cohort with unmonitored breath hold manoeuvres (p<0.0001). The Mean TA (95%CI) score was 6.93 (6.05 to 7.82) in COP patients and 3.81 (2.89 to 4.73) in GOT (p<0.0001) patients. In children with comparable CF lung disease, spirometric breath hold monitoring during examination yielded a large difference in lung volume between inhalation and exhalation, and allowed for a significantly greater measured change in lung density and TA score, compared to unmonitored breath hold maneuvers. This has implications to the clinical use of chest CT, especially in children with early CF lung disease. Copyright © 2013 European Cystic Fibrosis Society. Published by Elsevier B.V. All rights reserved.

Quantifying the Contributions of Environmental Parameters to Ceres Surface Net Radiation Error in China

NASA Astrophysics Data System (ADS)

Pan, X.; Yang, Y.; Liu, Y.; Fan, X.; Shan, L.; Zhang, X.

2018-04-01

Error source analyses are critical for the satellite-retrieved surface net radiation (Rn) products. In this study, we evaluate the Rn error sources in the Clouds and the Earth's Radiant Energy System (CERES) project at 43 sites from July in 2007 to December in 2007 in China. The results show that cloud fraction (CF), land surface temperature (LST), atmospheric temperature (AT) and algorithm error dominate the Rn error, with error contributions of -20, 15, 10 and 10 W/m2 (net shortwave (NSW)/longwave (NLW) radiation), respectively. For NSW, the dominant error source is algorithm error (more than 10 W/m2), particularly in spring and summer with abundant cloud. For NLW, due to the high sensitivity of algorithm and large LST/CF error, LST and CF are the largest error sources, especially in northern China. The AT influences the NLW error large in southern China because of the large AT error in there. The total precipitable water has weak influence on Rn error even with the high sensitivity of algorithm. In order to improve Rn quality, CF and LST (AT) error in northern (southern) China should be decreased.

Safety of bronchoalveolar lavage in young children with cystic fibrosis.

PubMed

Wainwright, Claire E; Grimwood, Keith; Carlin, John B; Vidmar, Suzanna; Cooper, Peter J; Francis, Paul W; Byrnes, Catherine A; Whitehead, Bruce F; Martin, A James; Robertson, Ian F; Cooper, David M; Dakin, Carolyn J; Masters, Ian B; Massie, R John; Robinson, Philip J; Ranganathan, Sarath; Armstrong, David S; Patterson, Lyndall K; Robertson, Colin F

2008-10-01

Our aim was to determine the safety of BAL in young children <6 years with CF. As part of a multi-center study of BAL-directed therapy, children with CF < 6 years had one or more BALs between September 1999 and December 2005. Adverse events were recorded intraoperatively and for 24 hr thereafter. Clinical characteristics before BAL, findings at bronchoscopy and BAL results were assessed as risk factors for adverse events. 333 BALs were conducted in 107 (56 males) children, median age 23.5 (range 1.6-67.5) months, including 170 (51%) for pulmonary exacerbation. 29 BALs (8.7%) were followed by fever >or=38.5 degrees C and 10 (3%) had clinically significant episodes (five intraoperative hemoglobin desaturations to <90% requiring intervention, one tachyarrhythmia, two needing post-operative supplemental oxygen, one hospitalization for stridor). Two contaminated bronchoscopes were detected. 180 minor adverse events were recorded in 174 (52%) BAL procedures (137 altered cough, 41 fever <38.5 degrees C). Low percentage BAL return (P = 0.002) and focal bronchitis (P = 0.02) were associated with clinically significant deterioration. Multivariable analysis identified Streptococcus pneumoniae (OR 22.3; 95% confidence interval (CI); 6.9,72), Pseudomonas aeruginosa (OR 2.4; 95% CI 1.0, 5.8), respiratory signs (OR 5.0; 95% CI 1.7, 14.6) and focal bronchitis (OR 5.9; 95% CI 1.2, 29.8) as independent risk factors for post-bronchoscopy fever >or=38.5 degrees C. Adverse events are common with BAL in young CF children, but are usually transient and well tolerated. Parents should be counseled that signs of a pre-existing lower respiratory infection are associated with increased risk of post-BAL fever. (c) 2008 Wiley-Liss, Inc.

Chest computed tomography scores are predictive of survival in patients with cystic fibrosis awaiting lung transplantation.

PubMed

Loeve, Martine; Hop, Wim C J; de Bruijne, Marleen; van Hal, Peter T W; Robinson, Phil; Aitken, Moira L; Dodd, Jonathan D; Tiddens, Harm A W M

2012-05-15

Up to one-third of patients with cystic fibrosis (CF) awaiting lung transplantation (LTX) die while waiting. Inclusion of computed tomography (CT) scores may improve survival prediction models such as the lung allocation score (LAS). This study investigated the association between CT and survival in patients with CF screened for LTX. Clinical data and chest CTs of 411 patients with CF screened for LTX between 1990 and 2005 were collected from 17 centers. CTs were scored with the Severe Advanced Lung Disease (SALD) four-category scoring system, including the components infection/inflammation (INF), air trapping/hypoperfusion (AT), normal/hyperperfusion (NOR), and bulla/cysts (BUL). The volume of each component was computed using semiautomated software. Survival analysis included Kaplan-Meier curves and Cox regression models. Three hundred and sixty-six (186 males) of 411 patients entered the waiting list (median age, 23 yr; range, 5-58 yr). Subsequently, 67 of 366 (18%) died while waiting, 263 of 366 (72%) underwent LTX, and 36 of 366 (10%) were awaiting LTX at the census date. INF and LAS were significantly associated with waiting list mortality in univariate analyses. The multivariate Cox model including INF and LAS grouped in tertiles, and comparing tertiles 2 and 3 with tertile 1, showed waiting list mortality hazard ratios of 1.62 (95% confidence interval [95% CI], 0.78-3.36; P = 0.19) and 2.65 (95% CI, 1.35-5.20; P = 0.005) for INF, and 1.42 (95% CI, 0.63-3.24; P = 0.40), and 2.32 (95% CI, 1.17-4.60; P = 0.016) for LAS, respectively. These results indicated that INF and LAS had significant, independent predictive value for survival. CT score INF correlates with survival, and adds to the predictive value of LAS.

Combination of cisplatin/S-1 in the treatment of patients with advanced gastric or gastroesophageal adenocarcinoma: Results of noninferiority and safety analyses compared with cisplatin/5-fluorouracil in the First-Line Advanced Gastric Cancer Study.

PubMed

Ajani, J A; Buyse, M; Lichinitser, M; Gorbunova, V; Bodoky, G; Douillard, J Y; Cascinu, S; Heinemann, V; Zaucha, R; Carrato, A; Ferry, D; Moiseyenko, V

2013-11-01

The aim of developing oral fluorouracil (5-FU) is to provide a more convenient administration route with similar efficacy and the best achievable tolerance. S-1, a novel oral fluoropyrimidine, was specifically designed to overcome the limitations of intravenous fluoropyrimidine therapies. A multicentre, randomised phase 3 trial was undertaken to compare S-1/cisplatin (CS) with infusional 5-FU/cisplatin (CF) in 1053 patients with untreated, advanced gastric/gastroesophageal adenocarcinoma. This report discusses a post-hoc noninferiority overall survival (OS) and safety analyses. Results (1029 treated; CS = 521/CF = 508) revealed OS in CS (8.6 months) was statistically noninferior to CF (7.9 months) [hazard ratio (HR) = 0.92 (two-sided 95% confidence interval (CI), 0.80-1.05)] for any margin equal to or greater than 1.05. Statistically significant safety advantages for the CS arm were observed [G3/4 neutropenia (CS, 18.6%; CF, 40.0%), febrile neutropenia (CS, 1.7%; CF, 6.9%), G3/4 stomatitis (CS, 1.3%; CF, 13.6%), diarrhoea (all grades: CS, 29.2%; CF, 38.4%) and renal adverse events (all grades: CS, 18.8%; CF, 33.5%)]. Hand-foot syndrome, infrequently reported, was mainly grade 1/2 in both arms. Treatment-related deaths were significantly lower in the CS arm than the CF arm (2.5% and 4.9%, respectively; P<0.047). CS is noninferior to CF with a better safety profile and provides a new treatment option for patients with advanced gastric carcinoma. Copyright © 2013 Elsevier Ltd. All rights reserved.

[Fat-soluble vitamins supplementation in patients with cystic fibrosis: is enough Aquadek's®?].

PubMed

González Jiménez, David; Bousoño García, Carlos; Díaz Martin, Juan Jose; Jiménez Treviño, Santiago

2015-04-01

Evaluate the safety and efficacy of a novel polyvitaminic (Aquadek's®) in patients with Cystic Fibrosis (CF). Prospective, longitudinal and non-randomized study. CF patients with pancreatic insufficiency and clinically stable were given Aquadek's® (two chewable tablets) daily for 12 months. Serum levels of retinol, beta-carotene, 25 OH vitamin D and α-tocopherol were evaluated twelve months before, at baseline and 12 months after. paired t tests. 28 patients aged 6 to 39 years (median 18.5 years) were included. Aquadek's® supplementation led to an increase in vitamin A dose and a decrease in the number of tablets administered. At baseline, 89% had at least one vitamin deficiency (61% pro-Vitamin A and 54% vitamin D). After one year, serum beta-carotene levels were increases 160 (95% CI 98-222) mcg/l (p <0.001) and decreased the percentage of patients with pro-vitamin A deficiency 46% (95% CI 22-64) (p <0.001). The proportion of patients with vitamin D insuficiency increased 18%(95% CI 2-32) (p =0.025). In any case serum levels exceeded the upper limits used to assess the risk of toxicity.Conclusions: Two daily Aquadek's® chewable tablets are safe and effective for maintaining vitamin A and E status of CF patients older than 6 years, although it is insufficient to normalize serum 25OHvitaminD according to the current recommendations for this disease. Copyright AULA MEDICA EDICIONES 2014. Published by AULA MEDICA. All rights reserved.

A compact gas-filled avalanche counter for DANCE

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wu, C. Y.; Chyzh, A.; Kwan, E.

2012-08-04

A compact gas-filled avalanche counter for the detection of fission fragments was developed for a highly segmented 4π γ-ray calorimeter, namely the Detector for Advanced Neutron Capture Experiments located at the Lujan Center of the Los Alamos Neutron Science Center. It has been used successfully for experiments with 235U, 238Pu, 239Pu, and 241Pu isotopes to provide a unique signature to differentiate the fission from the competing neutron-capture reaction channel. We also used it to study the spontaneous fission in 252Cf. The design and performance of this avalanche counter for targets with extreme α-decay rate up to ~2.4×108/s are described.

Impact of education and provision of complementary feeding on growth and morbidity in children less than 2 years of age in developing countries: a systematic review

PubMed Central

2013-01-01

Background About one third of deaths in children less than 5 years of age are due to underlying undernutrition. According to an estimate, 19.4% of children <5 years of age in developing countries were underweight (weight-for-age Z score <-2) and about 29.9% were stunted in the year 2011 (height-for-age Z score <-2). It is well recognized that the period of 6-24 months of age is one of the most critical time for the growth of the infant. Methods We included randomized, non-randomized trials and programs on the effect of complementary feeding (CF) (fortified or unfortified, but not micronutrients alone) and education on CF on children less than 2 years of age in low and middle income countries (LMIC). Studies that delivered intervention for at least 6 months were included; however, studies in which intervention was given for supplementary and therapeutic purposes were excluded. Recommendations are made for input to the Lives Saved Tool (LiST) model by following standardized guidelines developed by Child Health Epidemiology Reference Group (CHERG). Results We included 16 studies in this review. Amongst these, 9 studies provided education on complementary feeding, 6 provided complementary feeding (with our without education) and 1 provided both as separate arms. Overall, education on CF alone significantly improved HAZ (SMD: 0.23; 95% CI: 0.09, 0.36), WAZ (SMD 0.16, 95% CI: 0.05, 0.27), and significantly reduced the rates of stunting (RR 0.71; 95% CI: 0.56, 0.91). While no significant impact were observed for height and weight gain. Based on the subgroup analysis; ten studies from food secure populations indicated education on CF had a significant impact on height gain, HAZ scores, and weight gain, however, stunting reduced non-significantly. In food insecure population, CF education alone significantly improved HAZ scores, WAZ scores and significantly reduced the rates of stunting, while CF provision with or without education improved HAZ and WAZ scores significantly. Conclusion Complementary feeding interventions have a potential to improve the nutritional status of children in developing countries. However, large scale high quality randomized controlled trials are required to assess the actual impact of this intervention on growth and morbidity in children 6-24 months of age. Education should be combined with provision of complementary foods that are affordable, particularly for children in food insecure countries. PMID:24564534

Long-term clinical outcomes of 'Prairie Epidemic Strain' Pseudomonas aeruginosa infection in adults with cystic fibrosis.

PubMed

Somayaji, Ranjani; Lam, John C; Surette, Michael G; Waddell, Barbara; Rabin, Harvey R; Sibley, Christopher D; Purighalla, Swathi; Parkins, Michael D

2017-04-01

Epidemic Pseudomonas aeruginosa (PA) plays an important role in cystic fibrosis (CF) lung disease. A novel strain, the 'Prairie Epidemic Strain' (PES), has been identified in up to 30% of patients in Prairie-based Canadian CF centres. To determine the incidence, prevalence and long-term clinical impact of PES infection. A cohort of adults with CF was followed from 1980 to 2014 where bacteria isolated from clinical encounters were prospectively collected. Strain typing was performed using pulse-field gel electrophoresis and multilocus sequence typing. Patients were divided into one of four cohorts: no PA, transient PA, chronic PA with unique strains and chronic PES. Proportional Cox hazard and linear mixed models were used to assess for CF-associated respiratory death or transplantation, and rates of %FEV 1 and body mass index (BMI) decline. 274 patients (51.7% male) were analysed: 44--no PA, 29--transient PA, 137--unique PA, 64--PES. A total of 92 patients (33.6%) died or underwent lung transplantation (2423.0 patient-years). PES infection was associated with greater risk of respiratory death or lung transplant compared with the no PA group (aHR, 3.94 (95% CI 1.18 to 13.1); p=0.03) and unique PA group (aHR, 1.75 (95% CI 1.05 to 2.92) p=0.03). Rate of lung function decline (%FEV 1 predicted) was greatest in the PES group (1.73%/year (95% CI 1.63% to 1.82%); p<0.001). BMI improved over time but at an attenuated rate in the PES group (p=0.001). Infection with PES was associated with increased patient morbidity through three decades and manifested in an increased risk of respiratory death and/or lung transplantation. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

Enhancement of ionization efficiency of mass spectrometric analysis from non-electrospray ionization friendly solvents with conventional and novel ionization techniques.

PubMed

Jiang, Ping; Lucy, Charles A

2015-10-15

Electrospray ionization mass spectrometry (ESI-MS) has significantly impacted the analysis of complex biological and petroleum samples. However ESI-MS has limited ionization efficiency for samples in low dielectric and low polarity solvents. Addition of a make-up solvent through a T union or electrospray solvent through continuous flow extractive desorption electrospray ionization (CF-EDESI) enable ionization of analytes in non-ESI friendly solvents. A conventional make-up solvent addition setup was used and a CF-EDESI source was built for ionization of nitrogen-containing standards in hexane or hexane/isopropanol. Factors affecting the performance of both sources have been investigated and optimized. Both the make-up solvent addition and CF-EDESI improve the ionization efficiency for heteroatom compounds in non-ESI friendly solvents. Make-up solvent addition provides higher ionization efficiency than CF-EDESI. Neither the make-up solvent addition nor the CF-EDESI eliminates ionization suppression of nitrogen-containing compounds caused by compounds of the same chemical class. Copyright © 2015 Elsevier B.V. All rights reserved.

Canadian infants' nutrient intakes from complementary foods during the first year of life

PubMed Central

2010-01-01

Background Complementary feeding is currently recommended after six months of age, when the nutrients in breast milk alone are no longer adequate to support growth. Few studies have examined macro- and micro-nutrient intakes from complementary foods (CF) only. Our purpose was to assess the sources and nutritional contribution of CF over the first year of life. Methods In July 2003, a cross-sectional survey was conducted on a nationally representative sample of mothers with infants aged three to 12 months. The survey was administered evenly across all regions of the country and included a four-day dietary record to assess infants' CF intakes in household (tablespoon) measures (breast milk and formula intakes excluded). Records from 2,663 infants were analyzed for nutrient and CF food intake according to 12 categories. Mean daily intakes for infants at each month of age from CF were pooled and compared to the Dietary Reference Intakes for the respective age range. Results At three months of age, 83% of infants were already consuming infant cereals. Fruits and vegetables were among the most common foods consumed by infants at all ages, while meats were least common at all ages except 12 months. Macro- and micro-nutrient intakes from CF generally increased with age. All mean nutrient intakes, except vitamin D and iron, met CF recommendations at seven to 12 months. Conclusions Complementary foods were introduced earlier than recommended. Although mean nutrient intakes from CF at six to 12 months appear to be adequate among Canadian infants, further attention to iron and vitamin D intakes and sources may be warranted. PMID:20565759

Heart Rate Dependency of Large Artery Stiffness.

PubMed

Tan, Isabella; Spronck, Bart; Kiat, Hosen; Barin, Edward; Reesink, Koen D; Delhaas, Tammo; Avolio, Alberto P; Butlin, Mark

2016-07-01

Carotid-femoral pulse wave velocity (cfPWV) quantifies large artery stiffness, it is used in hemodynamic research and is considered a useful cardiovascular clinical marker. cfPWV is blood pressure (BP) dependent. Intrinsic heart rate (HR) dependency of cfPWV is unknown because increasing HR is commonly accompanied by increasing BP. This study aims to quantify cfPWV dependency on acute, sympathovagal-independent changes in HR, independent of BP. Individuals (n=52, age 40-93 years, 11 female) with in situ cardiac pacemakers or cardioverter defibrillators were paced at 60, 70, 80, 90, and 100 bpm. BP and cfPWV were measured at each HR. Both cfPWV (mean [95% CI], 0.31 [0.26-0.37] m/s per 10 bpm; P<0.001) and central aortic diastolic pressure (3.78 [3.40-4.17] mm Hg/10 bpm; P<0.001) increased with HR. The HR effect on cfPWV was isolated by correcting the BP effects by 3 different methods: (1) statistically, by a linear mixed model; (2) mathematically, using an exponential relationship between BP and cross-sectional lumen area; and (3) using measured BP dependency of cfPWV derived from changes in BP induced by orthostatic changes (seated and supine) in a subset of subjects (n=17). The BP-independent effects of HR on cfPWV were quantified as 0.20 [0.11-0.28] m/s per 10 bpm (P<0.001, method 1), 0.16 [0.11-0.22] m/s per 10 bpm (P<0.001, method 2), and 0.16 [0.11-0.21] m/s per 10 bpm (P<0.001, method 3). With a mean HR dependency in the range of 0.16 to 0.20 m/s per 10 bpm, cfPWV may be considered to have minimal physiologically relevant changes for small changes in HR, but larger differences in HR must be considered as contributing to significant differences in cfPWV. © 2016 American Heart Association, Inc.

Popcorn-Shaped FexO (Wüstite) Nanoparticles from a Single-Source Precursor: Colloidal Synthesis and Magnetic Properties

PubMed Central

2018-01-01

Colloidal nanoparticles (NPs) with myriads of compositions and morphologies have been synthesized and characterized in recent years. For wüstite FexO, however, obtaining phase-pure NPs with homogeneous morphologies have remained challenging. Herein, we report the colloidal synthesis of phase-pure FexO (x ≈ 0.94) popcorn-shaped NPs by decomposition of a single-source precursor, [Fe3(μ3-O)(CF3COO)(μ-CF3COO)6(H2O)2]·CF3COOH. The popcorn shape and multigrain structure had been reconstructed using high-angle annular dark-field scanning transmission electron micrograph (HAADF-STEM) tomography. This morphology offers a large surface area and internal channels and prevents further agglomeration and thermal tumbling of the subparticles. [Fe3(μ3-O)(CF3COO)(μ-CF3COO)6(H2O)2]·CF3COOH behaves as an antiferromagnetic triangle whose magnetic frustration is mitigated by the low symmetry of the complex. The popcorn-shaped FexO NPs show the typical wüstite antiferromagnetic transition at approximately 200 K, but behave very differently to their bulk counterpart below 200 K. The magnetization curves show a clear, unsymmetrical hysteresis, which arises from a combined effect of the superparamagnetic behavior and exchange bias. PMID:29606798

Popcorn-Shaped Fe x O (Wüstite) Nanoparticles from a Single-Source Precursor: Colloidal Synthesis and Magnetic Properties.

PubMed

Guntlin, Christoph P; Ochsenbein, Stefan T; Wörle, Michael; Erni, Rolf; Kravchyk, Kostiantyn V; Kovalenko, Maksym V

2018-02-27

Colloidal nanoparticles (NPs) with myriads of compositions and morphologies have been synthesized and characterized in recent years. For wüstite Fe x O, however, obtaining phase-pure NPs with homogeneous morphologies have remained challenging. Herein, we report the colloidal synthesis of phase-pure Fe x O ( x ≈ 0.94) popcorn-shaped NPs by decomposition of a single-source precursor, [Fe 3 (μ 3 -O)(CF 3 COO)(μ-CF 3 COO) 6 (H 2 O) 2 ]·CF 3 COOH. The popcorn shape and multigrain structure had been reconstructed using high-angle annular dark-field scanning transmission electron micrograph (HAADF-STEM) tomography. This morphology offers a large surface area and internal channels and prevents further agglomeration and thermal tumbling of the subparticles. [Fe 3 (μ 3 -O)(CF 3 COO)(μ-CF 3 COO) 6 (H 2 O) 2 ]·CF 3 COOH behaves as an antiferromagnetic triangle whose magnetic frustration is mitigated by the low symmetry of the complex. The popcorn-shaped Fe x O NPs show the typical wüstite antiferromagnetic transition at approximately 200 K, but behave very differently to their bulk counterpart below 200 K. The magnetization curves show a clear, unsymmetrical hysteresis, which arises from a combined effect of the superparamagnetic behavior and exchange bias.

Disparities in Mortality of Hispanic Cystic Fibrosis Patients in the United States: A National and Regional Cohort Study.

PubMed

Rho, Jason; Ahn, Chul; Gao, Ang; Sawicki, Gregory S; Keller, Ashley; Jain, Raksha

2018-05-09

Cystic Fibrosis (CF) patients of Hispanic origin are the largest growing minority, representing 8.5% of CF patients in the United States. No national survival analysis of this group has ever been undertaken. We aimed to determine whether Hispanic ethnicity within the CF population is associated with worse outcomes and whether any geographic differences exist. Using U.S. CF Foundation Patient Registry data from 2010-2014, we performed a retrospective cohort analysis comparing survival rates between Hispanics and non-Hispanics using Kaplan-Meier and Cox regression analysis. A subject's residence was categorized into geographic regions based on U.S. Census Bureau data: Northeast, Midwest, West and South. 29,637 patients were included in the study; 2,493 identified themselves as Hispanic. Hispanics had a lower survival probability overall, with a mean age of death of 22.4 ± 9.9 years compared to non-Hispanics of 28.1 ± 10.0 years (p < 0.0001). Multivariate cox proportional hazards modeling revealed that Hispanic CF patients had a 1.27 times higher rate of death compared to non-Hispanics (95% CI: 1.05 - 1.53) after adjusting for covariates including age, sex, genetic mutations, bacterial cultures, lung function, body mass index, use of CF respiratory therapies, low socioeconomic status, pancreatic enzyme use, and CF-related diabetes. When analyzed by region, Hispanics in the Midwest, Northeast, and West had shorter median survivals compared to Non-Hispanics, which was not demonstrated in the South. CF patients of Hispanic origin have a higher mortality rate than non-Hispanic CF patients. This pattern was seen in the Midwest, Northeast, and West but not in the South.

Attachment and spreadout study of 3T3 cells onto PP track etched films

NASA Astrophysics Data System (ADS)

Smolko, Eduardo; Mazzei, Ruben; Tadey, Daniel; Lombardo, Daniel

2001-12-01

Polymer surface modifications are obtained by the application of radiation treatments and other physico-chemical methods: fission fragment (ff) irradiation and etching. The biocompatibility of the surface is then observed by cell seeding and cell adhesion experiments. Approaches to improvement of the cell adhesion are obtained by different methods: for example, in PS, cell adhesion is improved after ion implantation; in PMMA, after bombarding the polymer, the surface is reconditioned with surfactants and proteins and in PVDF, cell adhesion is assayed on nuclear tracks membranes. In this work, we obtained important cell adhesion improvements in PP films by irradiation with swift heavy ions and subsequent etching of the nuclear tracks. We use BOPP (isotactic -25 μm thickness). Irrradiations were performed with a Cf-252 californium ff source. The source has a heavy ff and a light one, with 160-200 MeV energy divided among them corresponding to ff energies between 1 and 2 MeV/amu. A chemical etching procedure consisting of a solution of sulphuric acid and chromium three oxide at 85 °C was used. The 3T3 NIH fibroblast cell line was used for the cell adhesion experiment. Here we report for the first time, the results of a series of experiments by varying the ff fluence and the etching time showing that attachment and spreadout of cells are very much improved in this cell line according to the number of pores and the pore size.

NetCDF-CF: Supporting Earth System Science with Data Access, Analysis, and Visualization

NASA Astrophysics Data System (ADS)

Davis, E.; Zender, C. S.; Arctur, D. K.; O'Brien, K.; Jelenak, A.; Santek, D.; Dixon, M. J.; Whiteaker, T. L.; Yang, K.

2017-12-01

NetCDF-CF is a community-developed convention for storing and describing earth system science data in the netCDF binary data format. It is an OGC recognized standard with numerous existing FOSS (Free and Open Source Software) and commercial software tools can explore, analyze, and visualize data that is stored and described as netCDF-CF data. To better support a larger segment of the earth system science community, a number of efforts are underway to extend the netCDF-CF convention with the goal of increasing the types of data that can be represented as netCDF-CF data. This presentation will provide an overview and update of work to extend the existing netCDF-CF convention. It will detail the types of earth system science data currently supported by netCDF-CF and the types of data targeted for support by current netCDF-CF convention development efforts. It will also describe some of the tools that support the use of netCDF-CF compliant datasets, the types of data they support, and efforts to extend them to handle the new data types that netCDF-CF will support.

The relationship between irritable bowel syndrome, functional dyspepsia, chronic fatigue and overactive bladder syndrome: a controlled study 6 years after acute gastrointestinal infection.

PubMed

Persson, Robert; Wensaas, Knut-Arne; Hanevik, Kurt; Eide, Geir Egil; Langeland, Nina; Rortveit, Guri

2015-06-10

To investigate in a cohort with previous gastrointestinal infection and a control group the prevalence of overactive bladder syndrome (OAB), and how it was associated with three other functional disorders; irritable bowel syndrome (IBS), functional dyspepsia (FD) and chronic fatigue (CF). Controlled historic cohort study including 724 individuals with laboratory confirmed giardiasis six years earlier, and 847 controls matched by gender and age. Prevalence and odds ratios (OR) with 95 % confidence intervals (CI) were calculated. The prevalence of OAB was 18.7 % (134/716) in the exposed group and 13.6 % (113/833) in the control group (p = 0.007). The association between OAB and IBS was strong in the control group (OR: 2.42; 95 % CI: 1.45 to 4.04), but insignificant in the Giardia exposed (OR: 1.29; 95 % CI: 0.88 to 1.88). The association between OAB and FD was weak in both groups. CF was strongly associated with OAB (OR: 2.73; 95 % CI: 1.85 to 4.02 in the exposed and OR: 2.79; 95 % CI: 1.69 to 4.62 in the controls), and this association remained when comorbid conditions were excluded. Sporadic IBS was associated with increased risk of OAB, whereas post-infectious IBS was not. An apparent association between OAB and previous Giardia infection can be ascribed to comorbid functional disorders.

Correlated Production and Analog Transport of Fission Neutrons and Photons using Fission Models FREYA, FIFRELIN and the Monte Carlo Code TRIPOLI-4® .

NASA Astrophysics Data System (ADS)

Verbeke, Jérôme M.; Petit, Odile; Chebboubi, Abdelhazize; Litaize, Olivier

2018-01-01

Fission modeling in general-purpose Monte Carlo transport codes often relies on average nuclear data provided by international evaluation libraries. As such, only average fission multiplicities are available and correlations between fission neutrons and photons are missing. Whereas uncorrelated fission physics is usually sufficient for standard reactor core and radiation shielding calculations, correlated fission secondaries are required for specialized nuclear instrumentation and detector modeling. For coincidence counting detector optimization for instance, precise simulation of fission neutrons and photons that remain correlated in time from birth to detection is essential. New developments were recently integrated into the Monte Carlo transport code TRIPOLI-4 to model fission physics more precisely, the purpose being to access event-by-event fission events from two different fission models: FREYA and FIFRELIN. TRIPOLI-4 simulations can now be performed, either by connecting via an API to the LLNL fission library including FREYA, or by reading external fission event data files produced by FIFRELIN beforehand. These new capabilities enable us to easily compare results from Monte Carlo transport calculations using the two fission models in a nuclear instrumentation application. In the first part of this paper, broad underlying principles of the two fission models are recalled. We then present experimental measurements of neutron angular correlations for 252Cf(sf) and 240Pu(sf). The correlations were measured for several neutron kinetic energy thresholds. In the latter part of the paper, simulation results are compared to experimental data. Spontaneous fissions in 252Cf and 240Pu are modeled by FREYA or FIFRELIN. Emitted neutrons and photons are subsequently transported to an array of scintillators by TRIPOLI-4 in analog mode to preserve their correlations. Angular correlations between fission neutrons obtained independently from these TRIPOLI-4 simulations, using either FREYA or FIFRELIN, are compared to experimental results. For 240Pu(sf), the measured correlations were used to tune the model parameters.

True ternary fission, the collinear cluster tripartition (CCT) of {sup 252}Cf

DOE Office of Scientific and Technical Information (OSTI.GOV)

Oertzen, W. von; Pyatkov, Y. V.; Kamanin, D.

2012-10-20

In systematic work over the last decade (see Pyatkov et al. [12] and refs therein), the ternary fission decay of heavy nuclei, in {sup 235}U(n,fff) and {sup 252}Cf(sf) has been studied in a collinear geometry. The name used for this process is (CCT), with three fragments of similar size in a collinear decay, it is the true ternary fission. This decay has been observed in spontaneous fission as well as in a neutron induced reaction. The measurements are based on different experimental set-ups, with binary coincidences containing TOF and energy determinations. With two detector telescopes placed at 180 Degree-Sign ,more » the measurements of masses and energies of each of the registered two fragments, give complete kinematic solutions. Thus the missing mass events in binary coincidences can be determined, these events are obtained by blocking one of the lighter fragments on a structure in front of the detectors. The relatively high yield of CCT (more than 10{sup -3} per binary fission) is explained. It is due to the favourable Q-values (more positive than for binary) and the large phase space of the ternary CCT-decay, dominated by three (magic) clusters: e.g. isotopes of Sn, Ca and Ni, {sup 132}Sn+{sup 50}Ca+{sup 70}Ni. It is shown that the collinear (prolate) geometry has the favoured potential energy relative to the oblate shapes. The ternary fission is considered to be a sequential process. With this assumption the kinetic energies of the fragments have been calculated by Vijay et al.. The third fragments have very low kinetic energies (below 20 MeV) and have thus escaped their detection in previous work on 'ternary fission', where in addition an oblate shape and a triangle for the momentum vectors have been assumed.« less

The Tumor Necrosis Factor α (-308 A/G) Polymorphism Is Associated with Cystic Fibrosis in Mexican Patients

PubMed Central

Sanchez-Dominguez, Celia N.; Reyes-Lopez, Miguel A.; Bustamante, Adriana; Cerda-Flores, Ricardo M.; Villalobos-Torres, Maria del C.; Gallardo-Blanco, Hugo L.; Rojas-Martinez, Augusto; Martinez-Rodriguez, Herminia G.; Barrera-Saldaña, Hugo A.; Ortiz-Lopez, Rocio

2014-01-01

Environmental and genetic factors may modify or contribute to the phenotypic differences observed in multigenic and monogenic diseases, such as cystic fibrosis (CF). An analysis of modifier genes can be helpful for estimating patient prognosis and directing preventive care. The aim of this study is to determine the association between seven genetic variants of four modifier genes and CF by comparing their corresponding allelic and genotypic frequencies in CF patients (n = 81) and control subjects (n = 104). Genetic variants of MBL2 exon 1 (A, B, C and D), the IL-8 promoter (−251 A/T), the TNFα promoter (TNF1/TNF2), and SERPINA1 (PI*Z and PI*S) were tested in CF patients and control subjects from northeastern Mexico by PCR-RFLP. Results The TNF2 allele (P = 0.012, OR 3.43, 95% CI 1.25–9.38) was significantly associated with CF under the dominant and additive models but was not associated with CF under the recessive model. This association remained statistically significant after adjusting for multiple tests using the Bonferroni correction (P = 0.0482). The other tested variants and genotypes did not show any association with the disease. Conclusion An analysis of seven genetic variants of four modifier genes showed that one variant, the TNF2 allele, appears to be significantly associated with CF in Mexican patients. PMID:24603877

Salivary flow rate and biochemical composition analysis in stimulated whole saliva of children with cystic fibrosis.

PubMed

da Silva Modesto, Karine Barros; de Godói Simões, Jéssica Bueno; de Souza, Amanda Ferreira; Damaceno, Neiva; Duarte, Danilo Antonio; Leite, Mariana Ferreira; de Almeida, Eliete Rodrigues

2015-11-01

It is recognized that cystic fibrosis (CF) patients present a risk for oral diseases, since it affects exocrine glands, and the treatment consists of a carbohydrate-rich diet. Recognizing the protective function of saliva on maintaining oral health, the aim of the study was to evaluate salivary parameters in stimulated whole saliva from children with CF. A case-control study was conducted comparing stimulated whole saliva of healthy (n=28; control group) and CF children (n=21; experimental group). Salivary flow rate, initial pH, buffer capacity (total and in each range of pH), total protein and sialic acid (total, free, and conjugated) concentration, α-amylase and salivary peroxidase activities were evaluated. Data were compared by two-tailed Student t test (95% CI; p ≤ 0.05). CF patients presented a significant reduction in salivary parameters compared with the control group (p ≤ 0.05): salivary flow rate (36%), buffer capacity (pH range from 6.9 to 6.0), sialic acid concentration (total 75%, free 61%, and conjugated 83%); α-amylase and salivary peroxidase activities (55%). Additionally, a significant increase in total protein concentration (180%) of stimulated whole saliva from CF patients was verified compared with the control group (p ≤ 0.05). Children with CF presented significant changes in salivary composition, including salivary flow rate, buffering capacity and protective proteins of the oral cavity, compared with children without CF. Copyright © 2015 Elsevier Ltd. All rights reserved.

Reducing Anxiety in the Pediatric Emergency Department: A Comparative Trial

PubMed Central

Heilbrunn, Benjamin R.; Wittern, Rachael E.; Lee, Justin B.; Pham, Phung K.; Hamilton, Anita H.; Nager, Alan L.

2014-01-01

Background Anxiety among patients in a Pediatric Emergency Department (PED) can be significant but often goes unaddressed. Objective To determine whether exposure to Child Life (CL) or Hospital Clowning (HC) can reduce anxiety in children presenting to a PED. Methods Patients were randomized to CL, HC or control and assessed upon: entry to examination room (T1), prior to physician arrival (T2) and during physician examination (T3), using the modified Yale Preoperative Anxiety Scale (m-YPAS). CL and HC interventions occurred for 5–10 minutes prior to physician entry. Effects were analyzed using mixed ANOVA. Results m-YPAS scores ranged from 23 to 59, with a higher score indicating increased anxiety. Mixed ANOVA on the study sample (n=113) showed a significant interaction between groups (CL, HC, control) and time, p = .02. Further analyses indicated effect of group only at T2 (MCL = 23.8, 95% CI 23.2–24.5; MHC = 25.2, 95% CI 24.2–26.2; Mcontrol = 26.1, 95% CI 24.2–27.9), p = .02. Sub-analysis of patients with T1 m-YPAS score ≥ 28 (n=56) showed a significant interaction between group and time, p = .01. Further analysis showed effect of group only at T2 (MCL = 24.4, 95% CI 23.3–25.6; MHC = 27.0, 95% CI 25.2–28.7; Mcontrol = 29.2, 95% CI 25.6–32.7), p = .003. Conclusion CL services can reduce SA for patients presenting to a PED with heightened anxiety at baseline. This reduction occurred immediately following CL intervention, but was not observed in patients exposed to HC or during physician examination. PMID:25271180

Tectonic activity as a significant source of crustal tetrafluoromethane emissions to the atmosphere: observations in groundwaters along the San Andreas Fault

USGS Publications Warehouse

Deeds, Daniel A.; Kulongoski, Justin T.; Muhle, Jens; Weiss, Ray F.

2015-01-01

Tetrafluoromethane (CF4) concentrations were measured in 14 groundwater samples from the Cuyama Valley, Mil Potrero and Cuddy Valley aquifers along the Big Bend section of the San Andreas Fault System (SAFS) in California to assess whether tectonic activity in this region is a significant source of crustal CF4 to the atmosphere. Dissolved CF4 concentrations in all groundwater samples but one were elevated with respect to estimated recharge concentrations including entrainment of excess air during recharge (CreCre; ∼30 fmol kg−1 H2O), indicating subsurface addition of CF4 to these groundwaters. Groundwaters in the Cuyama Valley contain small CF4 excesses (0.1–9 times CreCre), which may be attributed to an in situ release from weathering and a minor addition of deep crustal CF4 introduced to the shallow groundwater through nearby faults. CF4 excesses in groundwaters within 200 m of the SAFS are larger (10–980 times CreCre) and indicate the presence of a deep crustal flux of CF4 that is likely associated with the physical alteration of silicate minerals in the shear zone of the SAFS. Extrapolating CF4 flux rates observed in this study to the full extent of the SAFS (1300 km × 20–100 km) suggests that the SAFS potentially emits (0.3–1)×10−1 kg(0.3–1)×10−1 kg CF4 yr−1 to the Earth's surface. For comparison, the chemical weathering of ∼7.5×104 km2∼7.5×104 km2 of granitic rock in California is estimated to release (0.019–3.2)×10−1 kg(0.019–3.2)×10−1 kg CF4 yr−1. Tectonic activity is likely an important, and potentially the dominant, driver of natural emissions of CF4 to the atmosphere. Variations in preindustrial atmospheric CF4 as observed in paleo-archives such as ice cores may therefore represent changes in both continental weathering and tectonic activity, including changes driven by variations in continental ice cover during glacial–interglacial transitions.

Diabetes in Cystic Fibrosis: Multicenter Screening Results Based on Current Guidelines

PubMed Central

Scheuing, Nicole; Holl, Reinhard W.; Dockter, Gerd; Fink, Katharina; Junge, Sibylle; Naehrlich, Lutz; Smaczny, Christina; Staab, Doris; Thalhammer, Gabriela; van Koningsbruggen-Rietschel, Silke; Ballmann, Manfred

2013-01-01

Background Published estimates on age-dependent frequency of diabetes in cystic fibrosis (CF) vary widely, and are based mostly on older data. However, CF treatment and prevention of comorbidities changed over recent years. In many studies, definition of cystic fibrosis-related diabetes (CFRD) is not in line with current guideline recommendations. Therefore, we evaluated age-dependent occurrence of glucose abnormalities and associated risk factors in CF patients who participated in a multicenter screening program using oral glucose tolerance tests (OGTT). Methods Between 2001 and 2010, 43 specialized CF centers from Germany and Austria serially performed 5,179 standardized OGTTs in 1,658 clinically stable, non-pregnant CF patients with no prior steroid medication or lung transplantation. Age-dependent occurrence of impaired fasting glucose (IFG), impaired glucose tolerance (IGT), IFG+IGT, one (DGT) or two consecutive (CFRD) diabetic OGTTs was analyzed, using Kaplan Meier curves. Cox proportional-hazards models were created to elucidate the influence of sex or underweight. Results At baseline/last OGTT, median age was 15.9 years/18.2 years and 30.6%/31.8% of patients were underweight. 25% of patients showed IFG at age 14.3 years; IGT at age 16.3 years; IFG+IGT combined at age 17.7 years. DGT was observed in 25% of patients at age 22.6 years; CFRD at age 34.5 years. Females had a 3.54 [95% CI 1.23–10.18] times higher risk for CFRD; risk for DGT was 2.21 [1.22–3.98] times higher. Underweight was a risk factor for IGT (HR [95% CI]: 1.38 [1.11–1.71]) and IFG+IGT (1.43 [1.11–1.83]), and in males also for DGT (1.49 [1.09–2.04]). Conclusions/Significance If confirmation of diabetes by a second test is required, as recommended in current guidelines, age at CFRD diagnosis was higher compared to most previous studies. However, known risk factors for glucose abnormalities in CF were confirmed. Confirmation of diabetic OGT by a repeat test is important for a consistent diagnosis of CFRD. PMID:24324701

Predictors of blood pressure at 7-13 years: The "new millennium baby" study.

PubMed

Brambilla, P; Bedogni, G; Pietrobelli, A; Cianfarani, S; Agostoni, C

2016-08-01

The purpose of this study is to evaluate the association between blood pressure (BP) at 7-13 years of age and body mass index (BMI), early feeding, lifestyle indicators, and parental characteristics. Retrospective plus cross-sectional cohort study was started in 1294 children born in 2000-2004, right from their birth in primary care settings. Early feeding was estimated by measuring breast-feeding (BF) duration, complementary feeding (CF) introduction time, and lifestyle indicators such as daily screen time and weekly extracurricular sports activity time. Parental education, smoking, and obesity-related diseases were also considered. Multivariable linear regression and mediation analysis were used. CF introduction at 5-6 months of age was a negative predictor of systolic and diastolic BP (mean systolic BP-standard deviation score (SDS) -0.38 [95% CI: -0.47, -0.29] (p < 0.001); mean diastolic BP-SDS -0.32 [95% CI: -0.40, -0.24]) (p < 0.001); BMI was a positive predictor of systolic and diastolic BP (p < 0.001); and parental hypertension was a positive predictor of diastolic BP (p < 0.05). Predictors of mean BMI-SDS at 7-13 years of age were birth weight, screen time, and parental obesity and smoking (p < 0.001). BF had no effect on BP or BMI. Mediation analysis showed virtually no indication of the effect of CF on BP mediated by BMI. CF introduction between 5 and 6 months of age could be associated with low BP at 7-13 years. The effect of CF on BP seems to be independent of BMI. Low screen time is associated with low BMI. CF time may play a role in the occurrence of surrogates of noncommunicable disorders in future. Copyright © 2015 The Italian Society of Diabetology, the Italian Society for the Study of Atherosclerosis, the Italian Society of Human Nutrition, and the Department of Clinical Medicine and Surgery, Federico II University. Published by Elsevier B.V. All rights reserved.

Infants Perceived as “Fussy” Are More Likely to Receive Complementary Foods Before 4 Months

PubMed Central

Bentley, Margaret; Borja, Judith; Davis Goldman, Barbara; Thompson, Amanda; Slining, Meghan; Adair, Linda

2011-01-01

OBJECTIVE: Our purpose was to assess early infant-feeding patterns in a cohort of low-income black mothers and to examine associations between maternal perception of infant temperament and complementary feeding (CF) before 4 months. METHODS: We used cross-sectional data from the 3-month visit (n = 217) of the Infant Care, Feeding and Risk of Obesity Study to assess relationships between early feeding of solids or juice and 6 dimensions of perceived infant temperament. Descriptive statistics were used to assess infant-feeding patterns, and logistic regression models were fit for each diet-temperament relationship found significant in the bivariate analyses. RESULTS: Seventy-seven percent of the infants were fed solid foods at 3 months, 25% were fed juice, and 6% were exclusively breastfed. In multivariable analyses, 2 dimensions of perceived infant temperament were associated with early feeding of solid foods (distress-to-limitations odds ratio [OR]: 1.97 [95% confidence interval (CI): 1.12–3.44]; activity-level OR: 1.75 [95% CI: 1.07–2.85]), whereas 1 dimension, low-intensity pleasure, was associated with early feeding of juice (OR: 0.51 [95% CI: 0.34–0.78]). Maternal characteristics significantly associated with early CF included breastfeeding, obesity, and depressive symptoms. CONCLUSIONS: Low-income black mothers may represent a priority population for interventions aimed at improving adherence to optimal infant feeding recommendations. That maternal perceptions of several domains of perceived infant temperament are related to early CF suggests that this is an important factor to include in future observational research and in the design of interventions. PMID:21220398

Infants perceived as "fussy" are more likely to receive complementary foods before 4 months.

PubMed

Wasser, Heather; Bentley, Margaret; Borja, Judith; Davis Goldman, Barbara; Thompson, Amanda; Slining, Meghan; Adair, Linda

2011-02-01

Our purpose was to assess early infant-feeding patterns in a cohort of low-income black mothers and to examine associations between maternal perception of infant temperament and complementary feeding (CF) before 4 months. We used cross-sectional data from the 3-month visit (n = 217) of the Infant Care, Feeding and Risk of Obesity Study to assess relationships between early feeding of solids or juice and 6 dimensions of perceived infant temperament. Descriptive statistics were used to assess infant-feeding patterns, and logistic regression models were fit for each diet-temperament relationship found significant in the bivariate analyses. Seventy-seven percent of the infants were fed solid foods at 3 months, 25% were fed juice, and 6% were exclusively breastfed. In multivariable analyses, 2 dimensions of perceived infant temperament were associated with early feeding of solid foods (distress-to-limitations odds ratio [OR]: 1.97 [95% confidence interval (CI): 1.12-3.44]; activity-level OR: 1.75 [95% CI: 1.07-2.85]), whereas 1 dimension, low-intensity pleasure, was associated with early feeding of juice (OR: 0.51 [95% CI: 0.34-0.78]). Maternal characteristics significantly associated with early CF included breastfeeding, obesity, and depressive symptoms. Low-income black mothers may represent a priority population for interventions aimed at improving adherence to optimal infant feeding recommendations. That maternal perceptions of several domains of perceived infant temperament are related to early CF suggests that this is an important factor to include in future observational research and in the design of interventions.

Inhaled corticosteroids and Aspergillus fumigatus isolation in cystic fibrosis.

PubMed

Noni, Maria; Katelari, Anna; Dimopoulos, George; Kourlaba, Georgia; Spoulou, Vana; Alexandrou-Athanassoulis, Helen; Doudounakis, Stavros-Eleftherios; Tzoumaka-Bakoula, Chryssa

2014-10-01

Aspergillus fumigatus isolation in cultures from respiratory specimens of patients with cystic fibrosis (CF) is quite common; however, the role of A. fumigatus as a pathogen and whether its presence is associated with progression of pulmonary disease remain unclear. We investigated the association between inhaled corticosteroids and the recovery of A. fumigatus by performing a retrospective cohort study of CF patients born between 1988 and 1996. The patients' medical records from their first visit to the CF Center until December 2010 were reviewed. Outcomes were the occurrence of A. fumigatus first isolation, chronic colonization, or the last visit at the CF Center. A number of possible confounders were included in the multivariate logistic regression analysis in order to identify an independent association between inhaled corticosteroids and colonization status. A total of 121 patients were included in the study. Thirty-nine patients (32.2%) had at least one positive culture and 14 (11.6%) developed chronic colonization. Multivariate logistic regression analysis was used to determine the independent effect of inhaled corticosteroids on the odds of first isolation (odds ratio [OR], 1.165; 95% confidence interval [CI], 1.015-1.337; P = 0.029) and chronic colonization (OR, 1.180; 95% CI, 1.029-1.353; P = 0.018). In conclusion, A. fumigatus first isolation and chronic colonization are associated with the duration of inhaled corticosteroid treatment. © The Author 2014. Published by Oxford University Press on behalf of The International Society for Human and Animal Mycology. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Caregiver coping, mental health and child problem behaviours in cystic fibrosis: a cross-sectional study.

PubMed

Sheehan, Jane; Hiscock, Harriet; Massie, John; Jaffe, Adam; Hay, Margaret

2014-04-01

In children with cystic fibrosis (CF) sleep, eating/mealtime, physiotherapy adherence and internalising problems are common. Caregivers also often report elevated depression, anxiety and stress symptoms. To identify, through principal components analysis (PCA), coping strategies used by Australian caregivers of children with CF and to assess the relationship between the derived coping components, caregiver mental health symptoms and child treatment related and non-treatment related problem behaviours. One hundred and two caregivers of children aged 3 to 8 years from three CF clinic sites in Australia, completed self-report questionnaires about their coping and mental health and reported on their child's sleep, eating/mealtime, treatment adherence and internalising and externalising behaviours. Two caregiver coping components were derived from the PCA: labelled 'proactive' and 'avoidant' coping. 'Avoidant' coping correlated moderately with caregiver depression (0.52), anxiety (0.57) and stress (0.55). For each unit increase in caregiver use of avoidant coping strategies, the odds of frequent child eating/mealtime behaviour problems increased by 1.3 (adjusted 95 % CI 1.0 to 1.6, p = .03) as did the odds of children experiencing borderline/clinical internalising behaviour problems (adjusted 95 % CI 1.1 to 1.7, p = .01). Proactive coping strategies were not associated with reduced odds of any child problem behaviours. Avoidant coping strategies correlated with caregiver mental health and child problem behaviours. Intervening with caregiver coping may be a way to improve both caregiver mental health and child problem behaviours in pre-school and early school age children with CF.

The effect of interaural fluctuation rate on correlation change discrimination.

PubMed

Goupell, Matthew J; Litovsky, Ruth Y

2014-02-01

While bilateral cochlear implants (CIs) provide some binaural benefits, these benefits are limited compared to those observed in normal-hearing (NH) listeners. The large frequency-to-electrode allocation bandwidths (BWs) in CIs compared to auditory filter BWs in NH listeners increases the interaural fluctuation rate available for binaural unmasking, which may limit binaural benefits. The purpose of this work was to investigate the effect of interaural fluctuation rate on correlation change discrimination and binaural masking-level differences in NH listeners presented a CI simulation using a pulsed-sine vocoder. In experiment 1, correlation-change just-noticeable differences (JNDs) and tone-in-noise thresholds were measured for narrowband noises with different BWs and center frequencies (CFs). The results suggest that the BW, CF, and/or interaural fluctuation rate are important factors for correlation change discrimination. In experiment 2, the interaural fluctuation rate was systematically varied and dissociated from changes in BW and CF by using a pulsed-sine vocoder. Results indicated that the interaural fluctuation rate did not affect correlation change JNDs for correlated reference noises; however, slow interaural fluctuations increased correlation change JNDs for uncorrelated reference noises. In experiment 3, the BW, CF, and vocoder pulse rate were varied while interaural fluctuation rate was held constant. JNDs increased for increasing BW and decreased for increasing CF. In summary, relatively fast interaural fluctuation rates are not detrimental for detecting changes in interaural correlation. Thus, limiting factors to binaural benefits in CI listeners could be a result of other temporal and/or spectral deficiencies from electrical stimulation.

Theoretical studies on the synthesis of SHE 290-302Og (Z=118) using 48Ca, 45Sc, 50Ti, 51V, 54Cr, 55Mn, 58Fe, 59Co and 64Ni induced reactions

NASA Astrophysics Data System (ADS)

Santhosh, K. P.; Safoora, V.

2018-05-01

Using the phenomenological model for production cross section (PMPC), the production cross sections for the synthesis of isotopes of superheavy element Og ( Z = 118) using the fusion reactions 48Ca+249-254Cf → 297-302Og, 45Sc+247,249Bk → 292,294Og, 50Ti + 242-248,250Cm → 292-298,300Og, 51V+241,243Am → 292,294Og, 54Cr + 238-242,244Pu → 292-296,298Og, 55Mn + 235-237Np → 290-292Og, 58Fe + 232-236, 238U → 290-294,296Og, 59Co + 231Pa → 290Og, and 64Ni + 228-230,232Cm → 292-294,296Og in xn (x=3,4,5) evaporation channel have been systematically studied at energies near and above the Coulomb barrier. We have predicted most suitable projectile-target combinations for the synthesis of isotopes 290-302Og among these reactions. Our calculated evaporation residue (ER) cross section values for the reaction 48Ca + 249Cf → 297Og is in excellent agreement with available experimental values. For the synthesis of Og, among all the reactions mentioned above, the 3n channel cross section (2458 fb) is larger for 48Ca + 251Cf → 299Og; 4n channel cross section (212 fb) is larger for 48Ca + 252Cf → 300Og and 5n channel cross section (34 fb) is larger for 48Ca + 253Cf → 301Og. The second largest 3n channel cross section (1143 fb) is obtained for the reaction, 50Ti + 245Cm → 295Og. Our studies will be useful for the future experiments to synthesize the isotopes of element Og which are not synthesized so far. We have also studied the effect of the use of mass values and shell correction of the Warsaw group which leads to a smaller ER cross section compared to the Moller group.

New evidence that a large proportion of human blood plasma cell-free DNA is localized in exosomes

PubMed Central

Jiang, Chao; Krzyzanowski, Gary D.; Ryan, Wayne L.

2017-01-01

Cell-free DNA (cfDNA) in blood is used as a source of genetic material for noninvasive prenatal and cancer diagnostic assays in clinical practice. Recently we have started a project for new biomarker discovery with a view to developing new noninvasive diagnostic assays. While reviewing literature, it was found that exosomes may be a rich source of biomarkers, because exosomes play an important role in human health and disease. While characterizing exosomes found in human blood plasma, we observed the presence of cfDNA in plasma exosomes. Plasma was obtained from blood drawn into K3EDTA tubes. Exosomes were isolated from cell-free plasma using a commercially available kit. Sizing and enumeration of exosomes were done using electron microscopy and NanoSight particle counter. NanoSight and confocal microscopy was used to demonstrate the association between dsDNA and exosomes. DNA extracted from plasma and exosomes was measured by a fluorometric method and a droplet digital PCR (ddPCR) method. Size of extracellular vesicles isolated from plasma was heterogeneous and showed a mean value of 92.6 nm and a mode 39.7 nm. A large proportion of extracellular vesicles isolated from plasma were identified as exosomes using a fluorescence probe specific for exosomes and three protein markers, Hsp70, CD9 and CD63, that are commonly used to identify exosome fraction. Fluorescence dye that stain dsDNA showed the association between exosomes and dsDNA. Plasma cfDNA concentration analysis showed more than 93% of amplifiable cfDNA in plasma is located in plasma exosomes. Storage of a blood sample showed significant increases in exosome count and exosome DNA concentration. This study provide evidence that a large proportion of plasma cfDNA is localized in exosomes. Exosome release from cells is a metabolic energy dependent process, thus suggesting active release of cfDNA from cells as a source of cfDNA in plasma. PMID:28850588

New evidence that a large proportion of human blood plasma cell-free DNA is localized in exosomes.

PubMed

Fernando, M Rohan; Jiang, Chao; Krzyzanowski, Gary D; Ryan, Wayne L

2017-01-01

Cell-free DNA (cfDNA) in blood is used as a source of genetic material for noninvasive prenatal and cancer diagnostic assays in clinical practice. Recently we have started a project for new biomarker discovery with a view to developing new noninvasive diagnostic assays. While reviewing literature, it was found that exosomes may be a rich source of biomarkers, because exosomes play an important role in human health and disease. While characterizing exosomes found in human blood plasma, we observed the presence of cfDNA in plasma exosomes. Plasma was obtained from blood drawn into K3EDTA tubes. Exosomes were isolated from cell-free plasma using a commercially available kit. Sizing and enumeration of exosomes were done using electron microscopy and NanoSight particle counter. NanoSight and confocal microscopy was used to demonstrate the association between dsDNA and exosomes. DNA extracted from plasma and exosomes was measured by a fluorometric method and a droplet digital PCR (ddPCR) method. Size of extracellular vesicles isolated from plasma was heterogeneous and showed a mean value of 92.6 nm and a mode 39.7 nm. A large proportion of extracellular vesicles isolated from plasma were identified as exosomes using a fluorescence probe specific for exosomes and three protein markers, Hsp70, CD9 and CD63, that are commonly used to identify exosome fraction. Fluorescence dye that stain dsDNA showed the association between exosomes and dsDNA. Plasma cfDNA concentration analysis showed more than 93% of amplifiable cfDNA in plasma is located in plasma exosomes. Storage of a blood sample showed significant increases in exosome count and exosome DNA concentration. This study provide evidence that a large proportion of plasma cfDNA is localized in exosomes. Exosome release from cells is a metabolic energy dependent process, thus suggesting active release of cfDNA from cells as a source of cfDNA in plasma.

Repeatability and Diagnostic Value of Nasal Potential Difference in a Genetically Admixed Population.

PubMed

Sad, Izabela Rocha; Higa, Laurinda Yoko Shinzato; Leal, Teresinha; Martins, Raisa da Silva; de Almeida, Ana Claudia; Ramos, Eloane Goncalves; de Cabello, Giselda Maria Kalil; Peixoto, Maria Virginia Marques

2016-01-01

The genetic diversity of the Brazilian population results from three ethnic groups admixture: Europeans, Africans and Amerindians, thus increasing the difficulty of performing cystic fibrosis (CF) diagnosis. The nasal potential difference (NPD) evaluates the cystic fibrosis transmembrane conductance regulator (CFTR) and epithelial sodium channel (ENaC) activity. Despite being a useful CF diagnostic test and a biomarker of CFTR-modulator drugs, it is also highly operator dependent. Therefore, it may be difficult to get accurate results and to interpret them. Wilschanski and Sermet scores were proposed to address these issues. This study aimed to evaluate repeatability and diagnostic value of NPD parameters and Wilschanski and Sermet scores in a CF center in Rio de Janeiro. NPD was performed in 78 subjects. Maximal PD, amiloride response, total chloride response, and Wilschanski and Sermet scores were explored as means (confidence interval, CI). One-way ANOVA was used to compare mean differences and Scheffe test was used to pair-wise comparisons. Repeatability was evaluated by scatter and Bland-Altman plots. The Ethics Committee of the CF Center has approved the study protocol. Parents and adult participants signed an informed consent form. Forty-eight healthy-volunteers, 19 non-CF and 11 CF patients were enrolled in this study. Significant differences were found when comparing CF patients' NPD parameters to the other two groups (P = 0.000). Moreover, no significant differences were found when parameters from non-CF patients were compared with those from healthy volunteers (P > 0.05). The means of NPD parameters and diagnostic scores of each group were in concordance with disease/non-disease conditions. The repeatability data - Wilschanski and Sermet and NPD - allow NPD to be performed in this Brazilian CF Center. The present study gathered consistent data for Bland-Altman plots. The results of Wilschanski and Sermet diagnostic scores suggest that they were concordant with CF/non-CF conditions. More NPD tests should be performed in the Rio de Janeiro CF dynamic cohort to contribute to international NPD validation studies and to provide NPD as a biomarker in Brazil.

Repeatability and Diagnostic Value of Nasal Potential Difference in a Genetically Admixed Population

PubMed Central

Sad, Izabela Rocha; Higa, Laurinda Yoko Shinzato; Leal, Teresinha; Martins, Raisa da Silva; de Almeida, Ana Claudia; Ramos, Eloane Goncalves; de Cabello, Giselda Maria Kalil; Peixoto, Maria Virginia Marques

2016-01-01

Background The genetic diversity of the Brazilian population results from three ethnic groups admixture: Europeans, Africans and Amerindians, thus increasing the difficulty of performing cystic fibrosis (CF) diagnosis. The nasal potential difference (NPD) evaluates the cystic fibrosis transmembrane conductance regulator (CFTR) and epithelial sodium channel (ENaC) activity. Despite being a useful CF diagnostic test and a biomarker of CFTR-modulator drugs, it is also highly operator dependent. Therefore, it may be difficult to get accurate results and to interpret them. Wilschanski and Sermet scores were proposed to address these issues. This study aimed to evaluate repeatability and diagnostic value of NPD parameters and Wilschanski and Sermet scores in a CF center in Rio de Janeiro. Methods NPD was performed in 78 subjects. Maximal PD, amiloride response, total chloride response, and Wilschanski and Sermet scores were explored as means (confidence interval, CI). One-way ANOVA was used to compare mean differences and Scheffe test was used to pair-wise comparisons. Repeatability was evaluated by scatter and Bland-Altman plots. The Ethics Committee of the CF Center has approved the study protocol. Parents and adult participants signed an informed consent form. Results Forty-eight healthy-volunteers, 19 non-CF and 11 CF patients were enrolled in this study. Significant differences were found when comparing CF patients’ NPD parameters to the other two groups (P = 0.000). Moreover, no significant differences were found when parameters from non-CF patients were compared with those from healthy volunteers (P > 0.05). The means of NPD parameters and diagnostic scores of each group were in concordance with disease/non-disease conditions. The repeatability data - Wilschanski and Sermet and NPD - allow NPD to be performed in this Brazilian CF Center. Conclusions The present study gathered consistent data for Bland-Altman plots. The results of Wilschanski and Sermet diagnostic scores suggest that they were concordant with CF/non-CF conditions. More NPD tests should be performed in the Rio de Janeiro CF dynamic cohort to contribute to international NPD validation studies and to provide NPD as a biomarker in Brazil. PMID:26668678

The synthesis of tritium-labelled human corticotropin of high specific radioactivity.

PubMed Central

Brundish, D E; Wade, R

1977-01-01

Human [[3,5-3H2]Tyr23]corticotropin-(1-39)-nonatriacontapeptide of specific radioactivity 25.2 Ci/mmol, identical with unlabelled human corticotropin by several criteria, was prepared via the fully protected di-iodotyrosine compound. The latter was synthesized by classical procedures. PMID:196594

Right ventricular response to pulsatile load is associated with early right heart failure and mortality after left ventricular assist device.

PubMed

Grandin, E Wilson; Zamani, Payman; Mazurek, Jeremy A; Troutman, Gregory S; Birati, Edo Y; Vorovich, Esther; Chirinos, Julio A; Tedford, Ryan J; Margulies, Kenneth B; Atluri, Pavan; Rame, J Eduardo

2017-01-01

Right ventricular (RV) adaptation to afterload is crucial for patients undergoing continuous-flow left ventricular assist device (cf-LVAD) implantation. We hypothesized that stratifying patients by RV pulsatile load, using pulmonary arterial compliance (PAC), and RV response to load, using the ratio of central venous to pulmonary capillary wedge pressure (CVP:PCWP), would identify patients at high risk for early right heart failure (RHF) and 6-month mortality after cf-LVAD. During the period from January 2008 to June 2014, we identified 151 patients at our center with complete hemodynamics prior to cf-LVAD. Pulsatile load was estimated using PAC indexed to body surface area (BSA), according to the formula: indexed PAC (PACi) = [SV / (PA systolic - PA diastolic )] / BSA, where SV is stroke volume and PA is pulmonary artery. Patients were divided into 4 hemodynamic groups by PACi and CVP:PCWP. RHF was defined as the need for unplanned RVAD, inotropic support ≥14 days or death due to RHF within 14 days. Risk factors for RHF and 6-month mortality were examined using logistic regression and Cox proportional hazards modeling. Sixty-one patients (40.4%) developed RHF and 34 patients (22.5%) died within 6 months. Patients with RHF had lower PACi (0.92 vs 1.17 ml/mm Hg/m 2 , p = 0.008) and higher CVP:PCWP (0.48 vs 0.37, p = 0.001). Higher PACi was associated with reduced risk of RHF (adjusted odds ratio [adj-OR] 0.61, 95% confidence interval [CI] 0.39 to 0.94, p = 0.025) and low PACi with increased risk of 6-month mortality (adjusted hazard ratio [adj-HR] 3.18, 95% CI 1.40 to 7.25, p = 0.006). Compared to patients with low load (high PACi) and adequate right heart response to load (low CVP:PCWP), patients with low PACi and high CVP:PCWP had an increased risk of RHF (OR 4.74, 95% CI 1.23 to 18.24, p = 0.02) and 6-month mortality (HR 8.68, 95% CI 2.79 to 26.99, p < 0.001). A hemodynamic profile combining RV pulsatile load and response to load identifies patients at high risk for RHF and 6-month mortality after cf-LVAD. Copyright © 2016 International Society for Heart and Lung Transplantation. Published by Elsevier Inc. All rights reserved.

Microchannel plate special nuclear materials sensor

NASA Astrophysics Data System (ADS)

Feller, W. B.; White, P. L.; White, P. B.; Siegmund, O. H. W.; Martin, A. P.; Vallerga, J. V.

2011-10-01

Nova Scientific Inc., is developing for the Domestic Nuclear Detection Office (DNDO SBIR #HSHQDC-08-C-00190), a solid-state, high-efficiency neutron detection alternative to 3He gas tubes, using neutron-sensitive microchannel plates (MCPs) containing 10B and/or Gd. This work directly supports DNDO development of technologies designed to detect and interdict nuclear weapons or illicit nuclear materials. Neutron-sensitized MCPs have been shown theoretically and more recently experimentally, to be capable of thermal neutron detection efficiencies equivalent to 3He gas tubes. Although typical solid-state neutron detectors typically have an intrinsic gamma sensitivity orders of magnitude higher than that of 3He gas detectors, we dramatically reduce gamma sensitivity by combining a novel electronic coincidence rejection scheme, employing a separate but enveloping gamma scintillator. This has already resulted in a measured gamma rejection ratio equal to a small 3He tube, without in principle sacrificing neutron detection efficiency. Ongoing improvements to the MCP performance as well as the coincidence counting geometry will be described. Repeated testing and validation with a 252Cf source has been underway throughout the Phase II SBIR program, with ongoing comparisons to a small commercial 3He gas tube. Finally, further component improvements and efforts toward integration maturity are underway, with the goal of establishing functional prototypes for SNM field testing.

A study of commercially-available polyethylene terephthalate (PET) and polycarbonate as nuclear track detector materials

NASA Astrophysics Data System (ADS)

Espinosa, G.; Golzarri, J. I.; Vazquez-Lopez, C.; Trejo, R.; Lopez, K.; Rickards, J.

2014-07-01

In the study of the sensitivity of materials to be used as nuclear track detectors, it was found that commercial polyethylene terephthalate (PET) from Ciel® water bottles, commercial roof cover polycarbonate, and recycled packaging strips (recycled PET), can be used as nuclear track detectors. These three commercial materials present nuclear tracks when bombarded by 2.27 MeV nitrogen ions produced in a Pelletron particle accelerator, and by fission fragments from a 252Cf source (79.4 and 103.8 MeV), after a chemical etching with a 6.25M KOH solution, or with a 6.25M KOH solution with 20% methanol, both solutions at 60±1°C. As an example, the nitrogen ions deposit approximately 1 keV/nm in the form of ionization and excitation at the surface of PET, as calculated using the SRIM code. The fission fragments deposit up to 9 keV/nm at the surface, in both cases generating sufficient free radicals to initiate the track formation process. However, 5 MeV alpha particles, typical of radon (222Rn) emissions, deposit only 0.12 keV/nm, do not present tracks after the chemical etching process. This valuable information could be very useful for further studies of new materials in nuclear track methodology.

Investigation of Workplace-like Calibration Fields via a Deuterium-Tritium (D-T) Neutron Generator.

PubMed

Mozhayev, Andrey V; Piper, Roman K; Rathbone, Bruce A; McDonald, Joseph C

2017-04-01

Radiation survey meters and personal dosimeters are typically calibrated in reference neutron fields based on conventional radionuclide sources, such as americium-beryllium (Am-Be) or californium-252 (Cf), either unmodified or heavy-water moderated. However, these calibration neutron fields differ significantly from the workplace fields in which most of these survey meters and dosimeters are being used. Although some detectors are designed to yield an approximately dose-equivalent response over a particular neutron energy range, the response of other detectors is highly dependent upon neutron energy. This, in turn, can result in significant over- or underestimation of the intensity of neutron radiation and/or personal dose equivalent determined in the work environment. The use of simulated workplace neutron calibration fields that more closely match those present at the workplace could improve the accuracy of worker, and workplace, neutron dose assessment. This work provides an overview of the neutron fields found around nuclear power reactors and interim spent fuel storage installations based on available data. The feasibility of producing workplace-like calibration fields in an existing calibration facility has been investigated via Monte Carlo simulations. Several moderating assembly configurations, paired with a neutron generator using the deuterium tritium (D-T) fusion reaction, were explored.

Nuclear-Recoil Energy Scale in CDMS II Silicon Dark-Matter Detectors

DOE Office of Scientific and Technical Information (OSTI.GOV)

Agnese, R.; et al.

The Cryogenic Dark Matter Search (CDMS II) experiment aims to detect dark matter particles that elastically scatter from nuclei in semiconductor detectors. The resulting nuclear-recoil energy depositions are detected by ionization and phonon sensors. Neutrons produce a similar spectrum of low-energy nuclear recoils in such detectors, while most other backgrounds produce electron recoils. The absolute energy scale for nuclear recoils is necessary to interpret results correctly. The energy scale can be determined in CDMS II silicon detectors using neutrons incident from a broad-spectrummore » $$^{252}$$Cf source, taking advantage of a prominent resonance in the neutron elastic scattering cross section of silicon at a recoil (neutron) energy near 20 (182) keV. Results indicate that the phonon collection efficiency for nuclear recoils is $$4.8^{+0.7}_{-0.9}$$% lower than for electron recoils of the same energy. Comparisons of the ionization signals for nuclear recoils to those measured previously by other groups at higher electric fields indicate that the ionization collection efficiency for CDMS II silicon detectors operated at $$\\sim$$4 V/cm is consistent with 100% for nuclear recoils below 20 keV and gradually decreases for larger energies to $$\\sim$$75% at 100 keV. The impact of these measurements on previously published CDMS II silicon results is small.« less

Experimental characterization of the AFIT neutron facility. Master's thesis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lessard, O.J.

1993-09-01

AFIT's Neutron Facility was characterized for room-return neutrons using a (252)Cf source and a Bonner sphere spectrometer with three experimental models, the shadow shield, the Eisenhauer, Schwartz, and Johnson (ESJ), and the polynomial models. The free-field fluences at one meter from the ESJ and polynomial models were compared to the equivalent value from the accepted experimental shadow shield model to determine the suitability of the models in the AFIT facility. The polynomial model behaved erratically, as expected, while the ESJ model compared to within 4.8% of the shadow shield model results for the four Bonner sphere calibration. The ratio ofmore » total fluence to free-field fluence at one meter for the ESJ model was then compared to the equivalent ratio obtained by a Monte Cario Neutron-Photon transport code (MCNP), an accepted computational model. The ESJ model compared to within 6.2% of the MCNP results. AFIT's fluence ratios were compared to equivalent ratios reported by three other neutron facilities which verified that AFIT's results fit previously published trends based on room volumes. The ESJ model appeared adequate for health physics applications and was chosen was chosen for calibration of the AFIT facility. Neutron Detector, Bonner Sphere, Neutron Dosimetry, Room Characterization.« less

Low cost mobile explosive/drug detection devices

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gozani, T.; Bendahan, J.

1999-06-10

Inspection technologies based on Thermal Neutron Analysis (TNA) and/or Fast Neutron Analysis (FNA) are the basis for relatively compact and low-cost, material-sensitive devices for a wide variety of inspection needs. The TNA allows the use of either isotropic neutron sources such as a {sup 252}Cf, or electronic neutron generators such as the d-T sealed neutron generator tubes. The latter could be used in a steady state mode or in slow (>{mu}s) pulsing mode, to separate the thermal neutron capture signatures following the pulse from the combination of the FNA plus TNA signatures during the pulse. Over the years, Ancore Corporationmore » has built and is continuing to develop a variety of inspection devices based on its TNA and FNA technologies: SPEDS--an explosive detection device for small parcels, portable electronics, briefcases and other similar carry-on items; MDS - a system for the detection or confirmation of buried mines; VEDS - a system for the detection of varied amounts of explosives and/or drugs concealed in passenger vehicles, pallets, lightly loaded trucks or containers, etc.; ACD - a device to clear alarms from a primary, non-specific explosive detection system for passenger luggage. The principle and performance of these devices will be shown and discussed.« less

Neutron-fragment and Neutron-neutron Correlations in Low-energy Fission

NASA Astrophysics Data System (ADS)

Lestone, J. P.

2016-01-01

A computational method has been developed to simulate neutron emission from thermal-neutron induced fission of 235U and from spontaneous fission of 252Cf. Measured pre-emission mass-yield curves, average total kinetic energies and their variances, both as functions of mass split, are used to obtain a representation of the distribution of fragment velocities. Measured average neutron multiplicities as a function of mass split and their dependence on total kinetic energy are used. Simulations can be made to reproduce measured factorial moments of neutron-multiplicity distributions with only minor empirical adjustments to some experimental inputs. The neutron-emission spectra in the rest-frame of the fragments are highly constrained by ENDF/B-VII.1 prompt-fission neutron-spectra evaluations. The n-f correlation measurements of Vorobyev et al. (2010) are consistent with predictions where all neutrons are assumed to be evaporated isotropically from the rest frame of fully accelerated fragments. Measured n-f and n-n correlations of others are a little weaker than the predictions presented here. These weaker correlations could be used to infer a weak scission-neutron source. However, the effect of neutron scattering on the experimental results must be studied in detail before moving away from a null hypothesis that all neutrons are evaporated from the fragments.

Gamma Ray Spectroscopy and SASSYER

NASA Astrophysics Data System (ADS)

Pauerstein, Benjamin; Bonniwell, Cain; Allmond, J. M.; Beausang, C. W.

2009-10-01

An experiment was performed to study the Gd and Tb nuclei resulting from a 27 MeV proton beam on a 156Gd target. This was conducted at Lawrence Berkeley National Laboratory using the STARS/LIBERACE array. The main focus of the experiment was on charged particle channels (p,d) into 155Gd and (p,t) into 154Gd. However, the trigger was either gamma-gamma or particle-gamma so new data was also obtained on 155Tb nuclei following fusion evaporation reactions. Preliminary analysis was conducted at Wright Nuclear Structure Lab where RADWARE programs were used to analyze the data and search for unknown gamma rays. A second, separate, experiment was conducted using the SASSYER (a gas-filled separator at Yale). In this experiment, fission fragments from a 252Cf source were focused to a DSSD and a Ge detector was used to search for either gamma-decay from long lived isomers in the fission fragments or to find gammas from recoil-beta-decay tagging on the fission fragments. The data collection seems to have gone smoothly, and the data is currently being sorted for analysis. This work was supported by the US Department of Energy under grant numbers DE-FG02-52NA26206 and DE-FG02-05ER41379.

Benchmarking the MCNP code for Monte Carlo modelling of an in vivo neutron activation analysis system.

PubMed

Natto, S A; Lewis, D G; Ryde, S J

1998-01-01

The Monte Carlo computer code MCNP (version 4A) has been used to develop a personal computer-based model of the Swansea in vivo neutron activation analysis (IVNAA) system. The model included specification of the neutron source (252Cf), collimators, reflectors and shielding. The MCNP model was 'benchmarked' against fast neutron and thermal neutron fluence data obtained experimentally from the IVNAA system. The Swansea system allows two irradiation geometries using 'short' and 'long' collimators, which provide alternative dose rates for IVNAA. The data presented here relate to the short collimator, although results of similar accuracy were obtained using the long collimator. The fast neutron fluence was measured in air at a series of depths inside the collimator. The measurements agreed with the MCNP simulation within the statistical uncertainty (5-10%) of the calculations. The thermal neutron fluence was measured and calculated inside the cuboidal water phantom. The depth of maximum thermal fluence was 3.2 cm (measured) and 3.0 cm (calculated). The width of the 50% thermal fluence level across the phantom at its mid-depth was found to be the same by both MCNP and experiment. This benchmarking exercise has given us a high degree of confidence in MCNP as a tool for the design of IVNAA systems.

Insulating epoxy/barite and polyester/barite composites for radiation attenuation.

PubMed

El-Sarraf, M A; El-Sayed Abdo, A

2013-09-01

A trial has been made to create insulating Epoxy/Barite (EP/Brt) (ρ=2.85 g cm(-3)) and Crosslinked Unsaturated Polyester/Barite (CUP/Brt) (ρ=3.25 g cm(-3)) composites with radiation attenuation and shielding capabilities. Experimental work regarding mechanical and physical properties was performed to study the composites integrity for practical applications. The properties were found to be reasonable. Radiation attenuation properties have been carried out using emitted collimated beam from a fission (252)Cf (100 µg) neutron source, and the neutron-gamma spectrometer with stilbene scintillator. The pulse shape discriminating (P.S.D) technique based on the zero cross-over method was used to discriminate between neutron and gamma-ray pulses. Thermal neutron fluxes, measured using the BF3 detector and thermal neutron detection system, were used to plot the attenuation relations. The fast neutron macroscopic effective removal cross-section ΣR, gamma ray total attenuation coefficient µ and thermal neutron macroscopic cross-section Σ have been evaluated. Theoretical calculations have been achieved using MCNP-4C2 code to calculate ΣR, µ and Σ. Also, MERCSF-N program was used to calculate macroscopic effective removal cross-section ΣR. Measured and calculated results have been compared and were found to be in reasonable agreement. Copyright © 2013 Elsevier Ltd. All rights reserved.

Influence of magnetite, ilmenite and boron carbide on radiation attenuation of polyester composites

NASA Astrophysics Data System (ADS)

El-Sarraf, M. A.; El-Sayed Abdo, A.

2013-07-01

This work is concerned with studying polyester/ magnetite CUP/Mag (ρ=2.75 g cm-3) and polyester/ ilmenite CUP/Ilm (ρ=2.7 g cm-3) composites for shielding of medical facilities, laboratory hot cells and for various purposes. Mechanical and physical properties such as compressive, flexural and impact strengths, as well as, a.c. electrical conductivity, specific heat, water absorption and porosity have been performed to evaluate the composite capabilities for radiation shielding. A collimated beam from fission 252Cf (100 µg) neutron source and neutron-gamma spectrometer with stilbene scintillator based on the zero cross over method and pulse shape discrimination (P.S.D.) technique have been used to measure neutron and gamma ray spectra. Fluxes of thermal neutrons have been measured using the BF3 detector and thermal neutron detection system. The attenuation parameters, namely macroscopic effective removal cross-section ΣR, total attenuation coefficient µ and macroscopic cross-section Σ of fast neutrons, gamma rays and thermal neutrons respectively have been evaluated. Theoretical calculations using MCNP-4C2 code was used to calculate ΣR,μ and Σ. Also, MERCSF-N program was used to calculate macroscopic effective removal cross-section ΣR. Measured and calculated results were compared and reasonable agreement was found.

Measurements of Masses with the Canadian Penning Trap

NASA Astrophysics Data System (ADS)

Kuta, Trenton; Nystrom, Andrew; Aprahamian, Ani; Brodeur, Maxime; Burdette, Daniel; Buchinger, Fritz; Orford, Rodney; Clark, Jason; Hirsh, Tsviki; Ling-Ying, Lin; Savard, Guy; Burkey, Mary; Klimes, Jeffery; Dwaipayan, Ray; Sharma, Kumar; Morgan, Graeme

2016-09-01

The primary focus of the Canadian Penning Trap (CPT) located at Argonne National Laboratory is to determine the masses of various isotopes relevant to the rprocess, an astrophysical process thought to be responsible for the creation of half the elements heavier than iron. Currently, the CPT is operating in conjunction with the CAlifornium Rare Isotope Breeder Upgrade (CARIBU) at Argonne National Laboratory's ATLAS facility in an attempt to measure neutron-rich nuclei produced by a 1.0 Curie source of 252Cf. The mass measurements of these nuclei are accomplished by measuring the cyclotron frequency of the isotopes captured in the trap. This frequency is measured with a position-sensitive microchannel plate (MCP), which records the relative position of the isotope in the trap for different phase accumulation times. This summer, the CPT group was able to successfully measure to a precision of 10 keV/c2 the masses of 142I and 156 , 158 , 159Nd, which are key nuclei needed to more accurately model the rprocess. This also marks the first time that any of these nuclei had ever been measured. This work was supported by the National Science Foundation under Contract PHY-1205412, the University of Notre Dame, and the U.S. Department of Energy, Office of Nuclear Physics, under Contract No. DE-AC02-06CH11357.

FIELD CALIBRATION OF A TLD ALBEDO DOSEMETER IN THE HIGH-ENERGY NEUTRON FIELD OF CERF.

PubMed

Haninger, T; Kleinau, P; Haninger, S

2017-04-28

The new albedo dosemeter-type AWST-TL-GD 04 has been calibrated in the CERF neutron field (Cern-EU high-energy Reference Field). This type of albedo dosemeter is based on thermoluminescent detectors (TLDs) and used by the individual monitoring service of the Helmholtz Zentrum München (AWST) since 2015 for monitoring persons, who are exposed occupationally against photon and neutron radiation. The motivation for this experiment was to gain a field specific neutron correction factor Nn for workplaces at high-energy particle accelerators. Nn is a dimensionless factor relative to a basic detector calibration with 137Cs and is used to calculate the personal neutron dose in terms of Hp(10) from the neutron albedo signal. The results show that the sensitivity of the albedo dosemeter for this specific neutron field is not significantly lower as for fast neutrons of a radionuclide source like 252Cf. The neutron correction factor varies between 0.73 and 1.16 with a midrange value of 0.94. The albedo dosemeter is therefore appropriate to monitor persons, which are exposed at high-energy particle accelerators. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Evidence for a causal relationship between early exocrine pancreatic disease and cystic fibrosis-related diabetes: a Mendelian randomization study.

PubMed

Soave, David; Miller, Melissa R; Keenan, Katherine; Li, Weili; Gong, Jiafen; Ip, Wan; Accurso, Frank; Sun, Lei; Rommens, Johanna M; Sontag, Marci; Durie, Peter R; Strug, Lisa J

2014-06-01

Circulating immunoreactive trypsinogen (IRT), a biomarker of exocrine pancreatic disease in cystic fibrosis (CF), is elevated in most CF newborns. In those with severe CF transmembrane conductance regulator (CFTR) genotypes, IRT declines rapidly in the first years of life, reflecting progressive pancreatic damage. Consistent with this progression, a less elevated newborn IRT measure would reflect more severe pancreatic disease, including compromised islet compartments, and potentially increased risk of CF-related diabetes (CFRD). We show in two independent CF populations that a lower newborn IRT estimate is associated with higher CFRD risk among individuals with severe CFTR genotypes, and we provide evidence to support a causal relationship. Increased loge(IRT) at birth was associated with decreased CFRD risk in Canadian and Colorado samples (hazard ratio 0.30 [95% CI 0.15-0.61] and 0.39 [0.18-0.81], respectively). Using Mendelian randomization with the SLC26A9 rs7512462 genotype as an instrumental variable since it is known to be associated with IRT birth levels in the CF population, we provide evidence to support a causal contribution of exocrine pancreatic status on CFRD risk. Our findings suggest CFRD risk could be predicted in early life and that maintained ductal fluid flow in the exocrine pancreas could delay the onset of CFRD. © 2014 by the American Diabetes Association.

Epidemic Pseudomonas aeruginosa infection in patients with cystic fibrosis is not a risk factor for poor clinical Outcomes following lung transplantation.

PubMed

Pritchard, Julia; Thakrar, Mitesh V; Somayaji, Ranjani; Surette, Michael G; Rabin, Harvey R; Helmersen, Doug; Lien, Dale; Purighalla, Swathi; Waddell, Barbara; Parkins, Michael D

2016-05-01

Epidemic strains of Pseudomonas aeruginosa (ePA) causing infection in cystic fibrosis (CF) have been commonly identified from clinics around the world. ePA disproportionally impacts CF patient pre-transplant outcomes manifesting in increased exacerbation frequency, worsened treatment burden and increased rate of lung function decline, and disproportionally leads to death and/or transplantation. As other CF factors such as pre-transplant infection with multi-resistant organisms, and isolation of P. aeruginosa in the post transplant graft, may impact post-transplant outcomes, we sought to determine if infection with ePA similarly adversely impact post-transplant outcomes. Between 1991-2014, 53 CF patients from our center received lung transplants. Bacterial strain typing was performed retrospectively on isolates collected prior to transplantation. Comprehensive chart reviews were performed to obtain baseline patient characteristics and post-transplant outcomes. Of the 53 transplanted patients, 57% of patients were infected with ePA prior to transplant; the other 43% of patients had unique strains of P. aeruginosa. Mean age at transplant was 29.0years for ePA and 33.3years for unique (p=0.04). There were no differences in overall survival (HR=0.75, 95% CI 0.31-1.79), bronchiolitis obliterans syndrome (BOS) free survival (HR 1.43, 95% CI 0.54-4.84) or all other assessed outcomes including exacerbation frequency, chronic renal failure, acute cellular rejections, Aspergillus infection, airway stenosis, and post-transplant lymphoproliferative disorder. Unlike pre-transplant outcomes, CF patients infected with ePA do not experience worse post-transplant outcomes than those infected with unique strains. Therefore, lung transplantation should be considered for all patients with P. aeruginosa infection and end stage lung disease, irrespective of infection with ePA. Copyright © 2015 European Cystic Fibrosis Society. Published by Elsevier B.V. All rights reserved.

Enhancement of discharge performance of Li/CF x cell by thermal treatment of CF x cathode material

NASA Astrophysics Data System (ADS)

Zhang, Sheng S.; Foster, Donald; Read, Jeffrey

In this work we demonstrate that the thermal treatment of CF x cathode material just below the decomposition temperature can enhance discharge performance of Li/CF x cells. The performance enhancement becomes more effective when heating a mixture of CF x and citric acid (CA) since CA serves as an extra carbon source. Discharge experiments show that the thermal treatment not only reduces initial voltage delay, but also raises discharge voltage. Whereas the measurement of powder impedance indicates the thermal treatment does not increase electronic conductivity of CF x material. Based on these facts, we propose that the thermal treatment results in a limited decomposition of CF x, which yields a subfluorinated carbon (CF x- δ), instead of a highly conductive carbon. In the case of CF x/AC mixture, the AC provides extra carbon that reacts with F 2 and fluorocarbon radicals generated by the thermal decomposition of CF x to form subfluorinated carbon. The process of thermal treatment is studied by thermogravimetric analysis and X-ray diffraction, and the effect of treatment conditions such as heating temperature, heating time and CF x/CA ratio on the discharge performance of CF x cathode is discussed. As an example, a Li/CF x cell using CF x treated with CA at 500 °C under nitrogen for 2 h achieved theretical specific capacity when being discharged at C/5. Impedance analysis indicates that the enhanced performance is attributed to a significant reduction in the cell reaction resistance.

A z-pinch photo-pumped pulsed atomic iodine laser

NASA Astrophysics Data System (ADS)

Stone, D. H.; Saunders, D. P.; Clark, M. C.

1984-03-01

A pulsed atomic iodine laser (CF3I) was designed and constructed using a coaxial xenon flash lamp as a pump source. The flash lamp was operated at low pressure to obtain pulse compression via xenon self-pinch. Electrical and optical diagnostics were performed for various xenon and CF3I pressures. Calorimeter data and burn patterns were obtained for the laser. Time-resolved spectroscopic data were taken throughout the CF3I pump band.

Vitamin A intake and serum retinol levels in children and adolescents with cystic fibrosis.

PubMed

Woestenenk, Janna W; Broos, Nancy; Stellato, Rebecca K; Arets, Hubertus G M; van der Ent, Cornelis K; Houwen, Roderick H J

2016-06-01

Pancreatic insufficient cystic fibrosis (CF) patients receive vitamin A supplementation according to CF-specific recommendations to prevent deficiencies. Whether current recommendations are optimal for preventing both deficiency and toxicity is a subject of debate. We assessed the longitudinal relation between serum retinol levels and appropriate variables. We studied vitamin A intake, and the long-term effects of vitamin A intake, coefficient of fat absorption (CFA) and immunoglobulin G (IgG) on serum retinol levels in 221 paediatrics CF patients during a seven-year follow up period. Total vitamin A intake, derived from 862 dietary assessments, exceeded the tolerable upper intake level in 30% of the assessments, mainly up to age six. Although CF patients failed to meet the CF-specific recommendations, serum retinol deficiency was found in only 17/862 (2%) of the measurements. Longitudinally, we observed no association to serum retinol levels for total vitamin A intake, CFA, gender or age but serum retinol levels were associated with serum IgG levels. Each g/L increase in serum IgG level would result in a 2.49% (95% CI -3.60 to -1.36%) reduction in serum retinol levels. In this large sample of children and adolescents with CF, serum retinol deficiency was rare despite lower than the CF-specific recommendations. However, the TUL was commonly exceeded. A reduction in CF-specific vitamin A supplementation recommendations should therefore be considered. Moreover, serum retinol levels were not associated with vitamin A intake, CFA, gender or age, although a decreased serum retinol was associated with an increased serum IgG. Copyright © 2015 Elsevier Ltd and European Society for Clinical Nutrition and Metabolism. All rights reserved.

Psychrophilic dry anaerobic digestion of dairy cow feces: Long-term operation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Massé, Daniel I., E-mail: Daniel.masse@agr.gc.ca; Cata Saady, Noori M.

2015-02-15

Highlights: • Psychrophilic dry anaerobic digestion (PDAD) of cow feces (CF) is feasible. • PDAD of CF is as efficient as mesophilic and thermophilic AD at TCL 21 days. • CF (13–16% TS at OLR 5.0 g TCOD{sub fed} kg{sup −1} inoculum d{sup −1}) yielded 222 ± 27 {sub N}L CH{sub 4} kg{sup −1} VS fed. - Abstract: This paper reports experimental results which demonstrate psychrophilic dry anaerobic digestion of cow feces during long-term operation in sequence batch reactor. Cow feces (13–16% total solids) has been anaerobically digested in 12 successive cycles (252 days) at 21 days treatment cycle lengthmore » (TCL) and temperature of 20 °C using psychrotrophic anaerobic mixed culture. An average specific methane yield (SMY) of 184.9 ± 24.0, 189.9 ± 27.3, and 222 ± 27.7 {sub N}L CH{sub 4} kg{sup −1} of VS fed has been achieved at an organic loading rate of 3.0, 4.0, and 5.0 g TCOD kg{sup −1} inoculum d{sup −1} and TCL of 21 days, respectively. The corresponding substrate to inoculum ratio (SIR) was 0.39 ± 0.06, 0.48 ± .02, 0.53 ± 0.05, respectively. Average methane production rate of 10 ± 1.4 {sub N}L CH{sub 4} kg{sup −1} VS fed d{sup −1} has been obtained. The low concentration of volatile fatty acids indicated that hydrolysis was the reaction limiting step.« less

48 CFR 206.302-3-70 - Solicitation provision.

Code of Federal Regulations, 2010 CFR

2010-10-01

... Open Competition 206.302-3-70 Solicitation provision. Use the provision at 252.206-7000, Domestic Source Restriction, in all solicitations that are restricted to domestic sources under the authority of...

Cell-free DNA detected by "liquid biopsy" as a potential prognostic biomarker in early breast cancer.

PubMed

Maltoni, Roberta; Casadio, Valentina; Ravaioli, Sara; Foca, Flavia; Tumedei, Maria Maddalena; Salvi, Samanta; Martignano, Filippo; Calistri, Daniele; Rocca, Andrea; Schirone, Alessio; Amadori, Dino; Bravaccini, Sara

2017-03-07

As conventional biomarkers for defining breast cancer (BC) subtypes are not always capable of predicting prognosis, search for new biomarkers which can be easily detected by liquid biopsy is ongoing. It has long been known that cell-free DNA (CF-DNA) could be a promising diagnostic and prognostic marker in different tumor types, although its prognostic value in BC is yet to be confirmed. This retrospective study evaluated the prognostic role of CF-DNA quantity and integrity of HER2, MYC, BCAS1 and PI3KCA, which are frequently altered in BC. We collected 79 serum samples before surgery from women at first diagnosis of BC at Forlì Hospital (Italy) from 2002 to 2010. Twenty-one relapsed and 58 non-relapsed patients were matched by subtype and age. Blood samples were also collected from 10 healthy donors. All samples were analyzed by Real Time PCR for CF-DNA quantity and integrity of all oncogenes. Except for MYC, BC patients showed significantly higher median values of CF-DNA quantity (ng) than healthy controls, who had higher integrity and lower apoptotic index. A difference nearing statistical significance was observed for HER2 short CF-DNA (p = 0.078, AUC value: 0.6305). HER2 short CF-DNA showed an odds ratio of 1.39 for disease recurrence with p = 0.056 (95% CI 0.991-1.973). Our study suggests that CF-DNA detected as liquid biopsy could have great potential in clinical practice once demonstration of its clinical validity and utility has been provided by prospective studies with robust assays.

ASSOCIATION OF INTERLEUKIN-10 -1082 A/G (RS1800896) POLYMORPHISM WITH SUSCEPTIBILITY TO GASTRIC CANCER: META-ANALYSIS OF 6,101 CASES AND 8,557 CONTROLS.

PubMed

Namazi, Abolfazl; Forat-Yazdi, Mohammad; Jafari, Mohammadali; Farahnak, Soudabeh; Nasiri, Rezvan; Foroughi, Elnaz; Abolbaghaei, Seyed Mojtaba; Neamatzadeh, Hossein

2018-01-01

The promoter -1082 A/G (rs1800896) polymorphism of Interleukin-10 (IL-10) gene have been widely reported and considered to have a significant role on gastric cancer risk, but the results are inconsistent. To clarify the association, we conducted a meta-analysis to investigate the associations IL-10 -1082 A/G polymorphism with gastric cancer. Eligible articles were identified by searching databases including PubMed, Web of Science, and Google Scholar up to August 03, 2017. Odds ratios (OR) with corresponding 95% confidence intervals (CIs) were used to assess the association. A total of 30 case-control studies with 6,101 cases and 8,557 controls were included in this meta-analysis. Overall, a significant association between IL-10 -1082 A/G polymorphism and gastric cancer risk was observed under the allele model (G vs A: OR=1.305, 95% CI=1.076-1.584; P=0.007), heterozygote model and (GA vs AA: OR=1.252, 95% CI=1.252-1.054; P=0.011) and dominant model (GG+GA vs AA: OR=1.264, 95% CI=1.053-1.516; P=0.012). In the subgroup analysis by ethnicity, increased gastric cancer risk were found in Asians under the allele model (G vs A: OR=1.520, 95% CI=1.172-1.973; P=0.002), homozygote model (GG+GA vs AA: OR=1.571, 95% CI=1.023-2.414; P= 0.039), heterozygote model (GA vs AA: OR=1.465, 95% CI=1.192-1.801; P≤0.001) and dominant model (GG+GA vs AA: OR=1.448, 95% CI=1.152-1.821; P=0.002), but not among Caucasian and Latinos populations. These results suggested that the IL-10 -1082 A/G (rs1800896) polymorphism might contribute to the gastric cancer susceptibility, especially among Asians.

Synthesis and photophysical studies of blue phosphorescent Ir(III) complexes with dimethylphenylphospine.

PubMed

Ham, Ho-Wan; Jung, Kyung-Yoon; Kim, Young-Sik

2012-02-01

New blue emitting mixed ligand iridium(III) complexes comprising one cyclometalating, two phosphines trans to each other such as Ir{(CF3)2Meppy}(PPhMe3)2(H)(L) [L = CI, NCMe, CN] [(CF3)2Meppy = 2-(3', 5'-bis-trifluoromethylphenyl)-4-methylpyridine] were synthesized and studied to tune the phosphorescence wavelength to the deep blue region and to enhance the luminescence efficiencies. To achieve deep blue emission, the trifluoromethyl group substituted on the phenyl ring and the methyl group substituted on the pyridyl ring increased HOMO-LUMO gap and achieved the hypsochromic shift. To gain insight into the factors responsible for the emission color change and the different luminescence efficiency, we investigate the electron-withdrawing capabilities of ancillary ligands using the DFT and TD-DFT calculations on the ground and excited states of the complexes. From these results, we discuss how the ancillary ligand influences the emission peak as well as the metal to ligand charge transfer (MLCT) transition efficiency. The maximum emission spectra of Ir{(CF3)2Meppy}(PPhMe3)2(H)(Cl), [Ir{(CF3),Meppy)(PPhMe3),(H)(NCMe)]+ and Ir{(CF3)2Meppy}(PPhMe3)2(H)(CN) were in the ranges of 441, 435, 434 nm, respectively.

Plasma cell-free DNA and qSOFA score predict 7-day mortality in 481 emergency department bacteraemia patients.

PubMed

Rannikko, Juha; Seiskari, Tapio; Huttunen, Reetta; Tarkiainen, Iina; Jylhävä, Juulia; Hurme, Mikko; Syrjänen, Jaana; Aittoniemi, Janne

2018-04-24

A few studies have shown that both quick Sequential Organ Failure Assessment (qSOFA) score and cell-free DNA (cfDNA) have potential use as a prognostic marker in patients with infection. We studied these two markers alone and in combination to identify those emergency department (ED) patients with the highest risk of death. Plasma cfDNA level was studied on days 0 to 4 after admittance to the ED from 481 culture-positive bloodstream infection cases. The qSOFA score was evaluated retrospectively according to Sepsis-3 definitions. The primary outcome was death by day 7. CfDNA on day 0 was significantly higher in non-survivors than in survivors (2.02 μg/ml vs. 1.35 μg/ml, p<0.001). CfDNA level was high (>1.69 μg/ml) in 134 (28%) out of 481 cases and the qSOFA score was ≥2 in 128 (28%) out of 458 cases. High cfDNA and qSOFA score ≥2 had 70% and 77% sensitivity and 76% and 76% specificity in predicting death by day 7, respectively. High cfDNA alone had odds ratio (OR) of 7.7 (95% CI 3.9-15.3) and qSOFA score ≥2 OR of 11.6 (5.5-24.3), but their combination had OR of 20.3 (10.0-41.4) in predicting death by day 7 when compared with those with low cfDNA and qSOFA score <2. Among the five cases with the highest cfDNA levels, there were three patients with severe disseminated intravascular coagulation. CfDNA and qSOFA score can be used independently to identify those bacteraemia patients at high risk of death, and combining these two markers gives additional advantage. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

Local control rates of metastatic renal cell carcinoma (RCC) to the bone using stereotactic body radiation therapy: Is RCC truly radioresistant?

PubMed

Amini, Arya; Altoos, Basel; Bourlon, Maria T; Bedrick, Edward; Bhatia, Shilpa; Kessler, Elizabeth R; Flaig, Thomas W; Fisher, Christine M; Kavanagh, Brian D; Lam, Elaine T; Karam, Sana D

2015-01-01

We report the radiographic and clinical response rate of stereotactic body radiation therapy (SBRT) compared with conventional fractionated external beam radiation therapy (CF-EBRT) for renal cell carcinoma (RCC) bone lesions treated at our institution. Forty-six consecutive patients were included in the study, with 95 total lesions treated (50 SBRT, 45 CF-EBRT). We included patients who had histologic confirmation of primary RCC and radiographic evidence of metastatic bone lesions. The most common SBRT regimen used was 27 Gy in 3 fractions. Median follow-up was 10 months (range, 1-64 months). Median time to symptom control between SBRT and CF-EBRT were 2 (range, 0-6 weeks) and 4 weeks (range, 0-7 weeks), respectively. Symptom control rates with SBRT and CF-EBRT were significantly different (P = .020) with control rates at 10, 12, and 24 months of 74.9% versus 44.1%, 74.9% versus 39.9%, and 74.9% versus 35.7%, respectively. The median time to radiographic failure and unadjusted pain progression was 7 months in both groups. When controlling for gross tumor volume, dose per fraction, smoking, and the use of systemic therapy, biologically effective dose ≥80 Gy was significant for clinical response (hazard ratio [HR], 0.204; 95% confidence interval [CI], 0.043-0.963; P = .046) and radiographic (HR, 0.075; 95% CI, 0.013-0.430; P = .004). When controlling for gross tumor volume and total dose, biologically effective dose ≥80 Gy was again predictive of clinical local control (HR, 0.140; 95% CI, 0.025-0.787; P = .026). Toxicity rates were low and equivalent in both groups, with no grade 4 or 5 toxicity reported. SBRT is both safe and effective for treating RCC bone metastases, with rapid improvement in symptoms after treatment and more durable clinical and radiographic response rate. Future prospective trials are needed to further define efficacy and toxicity of treatment, especially in the setting of targeted agents. Copyright © 2015 American Society for Radiation Oncology. Published by Elsevier Inc. All rights reserved.

Angiotensin Receptor Blockades Effect on Peripheral Muscular and Central Aortic Arterial Stiffness: A Meta-Analysis of Randomized Controlled Trials and Systematic Review.

PubMed

Yen, Chih-Hsuan; Lai, Yau-Huei; Hung, Chung-Lieh; Lee, Ping-Ying; Kuo, Jen-Yuan; Yeh, Hung-I; Hou, Charles Jia-Yin; Chien, Kuo-Liong

2014-03-01

Previous clinical trials have demonstrated the impact of blocking upstream renin-angiotensin-axis with angiotensin converting enzyme inhibitors (ACEIs) on arterial stiffness as evaluated by pulse-wave velocity (PWV). We ran a meta-analysis to evaluate the anti-stiffness effect of powerful downstream angiotensin receptor blockades (ARBs) on peripheral and central arterial stiffness (brachial to ankle, ba-PWV; carotid to femoral, cf-PWV, respectively), using a systematic review to assess the clinical arterial stiffness issues. For our study, we searched the PubMed and Cochrane Library databases from inception to June 2013, targeting randomized controlled trials. ARBs along with other antihypertensive agents, ACEIs, calcium channel blockers (CCBs), beta-blockers and diuretics were evaluated to ascertain their comparable effect on ba-PWV and cf-PWV, respectively. A meta-analysis was conducted utilizing the fixed or random effect of the weighted mean change difference between the ARB and comparator groups, depending on the I(2) statistic heterogeneity measurement. In 2 trials treating patients with ARBs (n = 30), the ARBs insignificantly reduced levels of ba-PWV (pooled mean change difference -188, 95% CI -687, 311, p = 0.24 with significant heterogeneity) as compared to other hypertensive agents (ACEIs and CCBs, n = 77). Interestingly, ARBs (n = 20) had a superior capacity to reduce levels of ba-PWV than CCBs (n = 20) in single study results (mean change difference -400, 95% CI -477, -322, p < 0.05). In 7 trials which included a total of 653 patients, treatment with ARBs (n = 308) also insignificantly reduced cf-PWV (pool mean change difference -0.197, 95% CI -0.54, 0.14, p = 0.218) as compared to other anti-hypertensive agents. Our data suggested that ARBs had a similar effect as other anti-hypertensive agents in reducing ba-PWV and cf-PWV. Upon systematic review, the renin-angiotensin-axis system mechanism seems more significant than the direct vessel dilatation system in anti-arterial stiffness mechanism. Angiotension receptor blockage; Arterial stiffness; Meta-analysis; Systematic review.

Clinical outcome following lung transplantation in patients with cystic fibrosis colonised with Burkholderia cepacia complex: results from two French centres.

PubMed

Boussaud, V; Guillemain, R; Grenet, D; Coley, N; Souilamas, R; Bonnette, P; Stern, M

2008-08-01

Infection with Burkholderia cepacia complex (BCC) is a life threatening complication of cystic fibrosis (CF), often seen as a contraindication for lung transplantation. A long term retrospective study was conducted of all patients with CF undergoing lung transplants from January 1990 to October 2006 in two French centres allowing transplantation in patients colonised with BCC. 22 of the 247 lung transplant patients with CF were infected with BCC (B. cenocepacia genomovar III (n = 8), B. multivorans genomovar II (n = 11), B. vietnamiensis genomovar V (n = 2) and B. stabilis genomovar IV (n = 1)). BCC colonisation was not associated with any significant excess mortality (HR 1.5, 95% CI 0.7 to 3.2; p = 0.58). However, early mortality rates tended to be higher in the BCC group than in the non-BCC group (3 month survival: 85% vs 95%, respectively; log rank p = 0.05). Univariate analysis showed that the risk of death was significantly higher for the eight patients infected with B. cenocepacia than for the other 14 colonised patients (HR 3.2, 95% CI 1.1 to 5.9; p = 0.04). None of the other risk factors tested-primary graft failure, late extubation, septicaemia-had a significant effect. The 5 year cumulative incidence rate of bronchiolitis obliterans syndrome was not significantly higher in the BCC group than in the non-BCC group (38% vs 24%, respectively; p = 0.35). Our results suggest that BCC infection with a non-genomovar III organism may not be associated with excess mortality after lung transplantation in patients with CF and should not be seen as sufficient reason to exclude lung transplantation. However, colonisation with B. cenocepacia remains potentially detrimental.

Lack of efficacy of Lactobacillus GG in reducing pulmonary exacerbations and hospital admissions in children with cystic fibrosis: A randomised placebo controlled trial.

PubMed

Bruzzese, Eugenia; Raia, Valeria; Ruberto, Eliana; Scotto, Riccardo; Giannattasio, Antonietta; Bruzzese, Dario; Cavicchi, Maria Cristina; Francalanci, Michela; Colombo, Carla; Faelli, Nadia; Daccò, Valeria; Magazzù, Giuseppe; Costa, Stefano; Lucidi, Vincenzina; Majo, Fabio; Guarino, Alfredo

2017-11-08

Intestinal dysbiosis has been described in Cystic Fibrosis (CF) and probiotics have been proposed to restore microbial composition. Aim of the study was to investigate the effects of Lactobacillus rhamnosus GG (LGG) on clinical outcomes in children with cystic fibrosis (CF). A multicentre, randomised double-blind, clinical trial was conducted in children with CF. After 6months of baseline assessment, enrolled children (2 to 16years of age) received Lactobacillus GG (6×10 9 CFU/day) or placebo for 12months. Primary outcomes were proportion of subjects with at least one pulmonary exacerbation and hospitalisation over 12months. Secondary endpoints were total number of exacerbations and hospitalisations, pulmonary function, and nutritional status. Ninety-five patients were enrolled (51/95 female; median age of 103±50months). In a multivariate GEE logistic analysis, the odds of experiencing at least one exacerbation was not significantly different between the two groups, also after adjusting for the presence of different microbial organisms and for the number of pulmonary exacerbations within 6months before randomisation (OR 0.83; 95% CI 0.38 to 1.82, p=0.643). Similarly, LGG supplementation did not significantly affect the odds of hospitalisations (OR 1.67; 95% CI 0.75 to 3.72, p=0.211). No significant difference was found for body mass index and FEV1. LGG supplementation had no effect on respiratory and nutritional outcomes in this large study population of children with CF under stringent randomised clinical trial conditions. Whether earlier interventions, larger doses, or different strains of probiotics may be effective is unknown. Copyright © 2017 European Cystic Fibrosis Society. Published by Elsevier B.V. All rights reserved.

Children and young adults with CF in the USA have better lung function compared with the UK.

PubMed

Goss, Christopher H; MacNeill, Stephanie J; Quinton, Hebe B; Marshall, Bruce C; Elbert, Alexander; Knapp, Emily A; Petren, Kristofer; Gunn, Elaine; Osmond, Joanne; Bilton, Diana

2015-03-01

People with cystic fibrosis (CF) are managed differently in the USA and UK providing an opportunity to learn from differences in practice patterns. To compare cross-sectional demographics, practice patterns and clinical outcomes between US and UK CF patients. This was a cross-sectional study using 2010 data from patients in the US Cystic Fibrosis Foundation and the UK Cystic Fibrosis patient registries. The a priori outcome measures of interest were lung function and nutritional status. Descriptive statistics and two sample comparisons were performed. Stratification and multivariable linear regression were used to adjust for confounding. The study cohort included 13 777 children and 11 058 adults from the USA and 3968 children and 3965 adults from the UK. In children, mean body mass index centiles were similar. Lung function (FEV1 and FVC% predicted) was significantly higher in US patients ages 6-25 years of age. In a regression model adjusted for only age, FEV1% predicted was on average 3.31% of predicted (95% CI 2.65 to 3.96) higher in the USA compared with the UK. When adjusted for age, age at diagnosis, gender, pancreatic insufficiency and genotype, FEV1% predicted was on average 3.03% of predicted (95% CI 2.37 to 3.69) higher in the USA compared with the UK These differences persisted despite adjustment for possible confounders. Hypertonic saline and dornase alfa were much more commonly prescribed in US children. Children and young adults with CF have better lung function in the USA compared with the UK despite similar nutritional status. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

NEOCENT: a randomised feasibility and translational study comparing neoadjuvant endocrine therapy with chemotherapy in ER-rich postmenopausal primary breast cancer.

PubMed

Palmieri, C; Cleator, S; Kilburn, L S; Kim, S B; Ahn, S-H; Beresford, M; Gong, G; Mansi, J; Mallon, E; Reed, S; Mousa, K; Fallowfield, L; Cheang, M; Morden, J; Page, K; Guttery, D S; Rghebi, B; Primrose, L; Shaw, J A; Thompson, A M; Bliss, J M; Coombes, R C

2014-12-01

Neoadjuvant endocrine therapy is an alternative to chemotherapy for women with oestrogen receptor (ER)-positive early breast cancer (BC). We aimed to assess feasibility of recruiting patients to a study comparing chemotherapy versus endocrine therapy in postmenopausal women with ER-rich primary BC, and response as well as translational endpoints were assessed. Patients requiring neoadjuvant therapy were randomised to chemotherapy: 6 × 3-weekly cycles FE₁₀₀C or endocrine therapy: letrozole 2.5 mg, daily for 18-23 weeks. Primary endpoints were recruitment feasibility and tissue collection. Secondary endpoints included clinical, radiological and pathological response rates, quality of life and translational endpoints. 63/80 patients approached were eligible, of those 44 (70, 95% CI 57-81) were randomised. 12 (54.5, 95% CI 32.2-75.6) chemotherapy patients showed radiological objective response compared with 13 (59.1, 95% CI 36.4-79.3) letrozole patients. Compared with baseline, mean Ki-67 levels fell in both groups at days 2-4 and at surgery [fold change: 0.24 (95% CI 0.12-0.51) and 0.24; (95% CI 0.15-0.37), respectively]. Plasma total cfDNA levels rose from baseline to week 8 [fold change: chemotherapy 2.10 (95% CI 1.47-3.00), letrozole 1.47(95% CI 0.98-2.20)], and were maintained at surgery in the chemotherapy group [chemotherapy 2.63; 95% CI 1.56-4.41), letrozole 0.95 (95% CI 0.71-1.26)]. An increase in plasma let-7a miRNA was seen at surgery for patients with objective radiological response to chemotherapy. Recruitment and tissue collection endpoints were met; however, a larger trial was deemed unfeasible due to slow accrual. Both regimens were equally efficacious. Dynamic changes were seen in Ki-67 and circulating biomarkers in both groups with increases in cfDNA and let-7a miRNA persisting until surgery for chemotherapy patients.

Synthesis of Metal-Oxide/Carbon-Fiber Heterostructures and Their Properties for Organic Dye Removal and High-Temperature CO2 Adsorption

NASA Astrophysics Data System (ADS)

Shao, Liangzhi; Nie, Shibin; Shao, Xiankun; Zhang, LinLin; Li, Benxia

2018-03-01

One-dimensional metal-oxide/carbon-fiber (MO/CF) heterostructures were prepared by a facile two-step method using the natural cotton as a carbon source the low-cost commercial metal salts as precursors. The metal oxide nanostructures were first grown on the cotton fibers by a solution chemical deposition, and the metal-oxide/cotton heterostructures were then calcined and carbonized in nitrogen atmosphere. Three typical MO/CF heterostructures of TiO2/CF, ZnO/CF, and Fe2O3/CF were prepared and characterized. The loading amount of the metal oxide nanostructures on carbon fibers can be tuned by controlling the concentration of metal salt in the chemical deposition process. Finally, the performance of the as-obtained MO/CF heterostructures for organic dye removal from water was tested by the photocatalytic degradation under a simulated sunlight, and their properties of high-temperature CO2 adsorption were predicted by the temperature programmed desorption. The present study would provide a desirable strategy for the synthesis of MO/CF heterostructures for various applications.

Correlating ion energies and CF{sub 2} surface production during fluorocarbon plasma processing of silicon

DOE Office of Scientific and Technical Information (OSTI.GOV)

Martin, Ina T.; Zhou Jie; Fisher, Ellen R.

2006-07-01

Ion energy distribution (IED) measurements are reported for ions in the plasma molecular beam source of the imaging of radicals interacting with surfaces (IRIS) apparatus. The IEDs and relative intensities of nascent ions in C{sub 3}F{sub 8} and C{sub 4}F{sub 8} plasma molecular beams were measured using a Hiden PSM003 mass spectrometer mounted on the IRIS main chamber. The IEDs are complex and multimodal, with mean ion energies ranging from 29 to 92 eV. Integrated IEDs provided relative ion intensities as a function of applied rf power and source pressure. Generally, higher applied rf powers and lower source pressures resultedmore » in increased ion intensities and mean ion energies. Most significantly, a comparison to CF{sub 2} surface interaction measurements previously made in our laboratories reveals that mean ion energies are directly and linearly correlated to CF{sub 2} surface production in these systems.« less

Longitudinal study of Stenotrophomonas maltophilia antibody levels and outcomes in cystic fibrosis patients.

PubMed

Wettlaufer, Jillian; Klingel, Michelle; Yau, Yvonne; Stanojevic, Sanja; Tullis, Elizabeth; Ratjen, Felix; Waters, Valerie

2017-01-01

Previous studies have shown an association between higher Stenotrophomonas maltophilia antibody levels and decreased lung function in patients with cystic fibrosis (CF). The purpose of this study was to assess the serologic response to S. maltophilia over time and to determine whether changes in antibody levels could predict clinical outcomes. Changes in S. maltophilia antibody levels in adult and pediatric patients with CF from 2008 to 2014 were assessed between groups of infection patterns. Regression models accounting for repeated measures were used to assess whether antibody levels could predict subsequent S. maltophilia microbiological status, and whether they are associated with lung function and subsequent pulmonary exacerbation. A total of 409 S. maltophilia antibody samples from 135 CF patients showed that antibody levels did not change significantly between study visits, regardless of infection group. Higher antibody levels were independently associated with future culture positivity (OR 1.62; 95% CI 1.09, 2.41; p=0.02). While higher antibody levels were not independently associated with decreases in FEV 1 % predicted, they were associated with an increased hazard ratio for subsequent pulmonary exacerbation (HR 1.3; 95% CI 1.1, 1.6; p<0.001). S. maltophilia antibody levels may be helpful to identify individuals at risk of exacerbation who may benefit from earlier antimicrobial treatment. Copyright © 2016 European Cystic Fibrosis Society. Published by Elsevier B.V. All rights reserved.

Social capital and health in a national cohort of 82,482 Open University adults in Thailand.

PubMed

Yiengprugsawan, Vasoontara; Khamman, Suwanee; Seubsman, Sam-Ang; Lim, Lynette L-Y; Sleigh, Adrian C

2011-05-01

We report associations between social capital and health among 82,482 adults in a national cohort of Open University students residing throughout Thailand.After adjusting for covariates, poor self-assessed health was positively associated with low social trust (OR = 1.88; 95% CI 1.76-2.01) and low social support (OR = 1.79; 95% CI 1.63-1.95). In addition, poor psychological health was also associated with low social trust (OR = 2.52; 95% CI 2.41-2.64) and low social support (OR = 1.80; 95% CI 1.69-1.92). Females, elderly, unpartnered, low income, and urban residents were associated with poor health. Findings suggest ways to improve social capital and heath in Thailand and other middle-income countries.

Correlates of aortic stiffness progression in patients with type 2 diabetes: importance of glycemic control: the Rio de Janeiro type 2 diabetes cohort study.

PubMed

Ferreira, Marcel T; Leite, Nathalie C; Cardoso, Claudia R L; Salles, Gil F

2015-05-01

The correlates of serial changes in aortic stiffness in patients with diabetes have never been investigated. We aimed to examine the importance of glycemic control on progression/regression of carotid-femoral pulse wave velocity (cf-PWV) in type 2 diabetes. In a prospective study, two cf-PWV measurements were performed with the Complior equipment in 417 patients with type 2 diabetes over a mean follow-up of 4.2 years. Clinical laboratory data were obtained at baseline and throughout follow-up. Multivariable linear/logistic regressions assessed the independent correlates of changes in cf-PWV. Median cf-PWV increase was 0.11 m/s per year (1.1% per year). Overall, 212 patients (51%) increased/persisted with high cf-PWV, while 205 (49%) reduced/persisted with low cf-PWV. Multivariate linear regression demonstrated direct associations between cf-PWV changes and mean HbA1c during follow-up (partial correlation 0.14, P = 0.005). On logistic regression, a mean HbA1c ≥7.5% (58 mmol/mol) was associated with twofold higher odds of having increased/persistently high cf-PWV during follow-up. Furthermore, the rate of HbA1c reduction relative to baseline levels was inversely associated with cf-PWV changes (partial correlation -0.11, P = 0.011) and associated with reduced risk of having increased/persistently high aortic stiffness (odds ratio 0.82 [95% CI 0.69-0.96]; P = 0.017). Other independent correlates of progression in aortic stiffness were increases in systolic blood pressure and heart rate between the two cf-PWV measurements, older age, female sex, and presence of dyslipidemia and retinopathy. Better glycemic control, together with reductions in blood pressure and heart rate, was the most important correlate to attenuate/prevent progression of aortic stiffness in patients with type 2 diabetes. © 2015 by the American Diabetes Association. Readers may use this article as long as the work is properly cited, the use is educational and not for profit, and the work is not altered.

The 11/2{sup -}[505] neutron extruder orbital in {sup 159}Sm

DOE Office of Scientific and Technical Information (OSTI.GOV)

Urban, W.; Faculty of Physics, University of Warsaw, ul. Hoza 69, PL-00-681 Warsaw; Pinston, J. A.

Excited states in {sup 159}Sm, populated following the spontaneous fission of {sup 252}Cf have been studied by means of {gamma} spectroscopy, using the Gammasphere array. In {sup 159}Sm we have identified an isomeric level with a half-life of T{sub 1/2}=116(8) ns at an excitation energy of 1276.8 keV and observed a rotational band on top of this isomer. On the basis of the observed properties of the isomer and the band on top of it we propose that the 1276.8-keV level in {sup 159}Sm corresponds to the 11/2{sup -}[505] neutron extruder configuration. The new excitation scheme of {sup 159}Sm ismore » compared to quasiparticle rotor model calculations.« less

Is chest CT useful in newborn screened infants with cystic fibrosis at 1 year of age?

PubMed Central

Thia, Lena P; Calder, Alistair; Stocks, Janet; Bush, Andrew; Owens, Catherine M; Wallis, Colin; Young, Carolyn; Sullivan, Yvonne; Wade, Angie; McEwan, Angus; Brody, Alan S

2014-01-01

Rationale Sensitive outcome measures applicable in different centres to quantify and track early pulmonary abnormalities in infants with cystic fibrosis (CF) are needed both for clinical care and interventional trials. Chest CT has been advocated as such a measure yet there is no validated scoring system in infants. Objectives The objectives of this study were to standardise CT data collection across multiple sites; ascertain the incidence of bronchial dilatation and air trapping in newborn screened (NBS) infants with CF at 1 year; and assess the reproducibility of Brody-II, the most widely used scoring system in children with CF, during infancy. Methods A multicentre observational study of early pulmonary lung disease in NBS infants with CF at age 1 year using volume-controlled chest CT performed under general anaesthetic. Main results 65 infants with NBS-diagnosed CF had chest CT in three centres. Small insignificant variations in lung recruitment manoeuvres but significant centre differences in radiation exposures were found. Despite experienced scorers and prior training, with the exception of air trapping, inter- and intraobserver agreement on Brody-II score was poor to fair (eg, interobserver total score mean (95% CI) κ coefficient: 0.34 (0.20 to 0.49)). Only 7 (11%) infants had a total CT score ≥12 (ie, ≥5% maximum possible) by either scorer. Conclusions In NBS infants with CF, CT changes were very mild at 1 year, and assessment of air trapping was the only reproducible outcome. CT is thus of questionable value in infants of this age, unless an improved scoring system for use in mild CF disease can be developed. PMID:24132911

Phase 1 environmental report for the Advanced Neutron Source at Oak Ridge National Laboratory

DOE Office of Scientific and Technical Information (OSTI.GOV)

Blasing, T.J.; Brown, R.A.; Cada, G.F.

1992-02-01

The US Department of Energy (DOE) has proposed the construction and operation of the Advanced Neutron Source (ANS), a 330-MW(f) reactor, at Oak Ridge National Laboratory (ORNL) to support neutron scattering and nuclear physics experiments. ANS would provide a steady-state source of neutrons that are thermalized to produce sources of hot, cold, and very coal neutrons. The use of these neutrons in ANS experiment facilities would be an essential component of national research efforts in basic materials science. Additionally, ANS capabilities would include production of transplutonium isotopes, irradiation of potential fusion and fission reactor materials, activation analysis, and production ofmore » medical and industrial isotopes such as {sup 252}Cf. Although ANS would not require licensing by the US Nuclear Regulatory Commission (NRC), DOE regards the design, construction, and operation of ANS as activities that would produce a licensable facility; that is, DOE is following the regulatory guidelines that NRC would apply if NRC were licensing the facility. Those guidelines include instructions for the preparation of an environmental report (ER), a compilation of available data and preliminary analyses regarding the environmental impacts of nuclear facility construction and operation. The ER, described and outlined in NRC Regulatory Guide 4.2, serves as a background document to facilitate the preparation of environmental impact statements (EISs). Using Regulatory Guide 4.2 as a model, this ANS ER provides analyses and information specific to the ANS site and area that can be adopted (and modified, if necessary) for the ANS EIS. The ER is being prepared in two phases. Phase 1 ER includes many of the data and analyses needed to prepare the EIS but does not include data or analyses of alternate sites or alternate technologies. Phase 2 ER will include the additional data and analyses stipulated by Regulatory Guide 4.2.« less

Coupled multi-group neutron photon transport for the simulation of high-resolution gamma-ray spectroscopy applications

NASA Astrophysics Data System (ADS)

Burns, Kimberly Ann

The accurate and efficient simulation of coupled neutron-photon problems is necessary for several important radiation detection applications. Examples include the detection of nuclear threats concealed in cargo containers and prompt gamma neutron activation analysis for nondestructive determination of elemental composition of unknown samples. In these applications, high-resolution gamma-ray spectrometers are used to preserve as much information as possible about the emitted photon flux, which consists of both continuum and characteristic gamma rays with discrete energies. Monte Carlo transport is the most commonly used modeling tool for this type of problem, but computational times for many problems can be prohibitive. This work explores the use of coupled Monte Carlo-deterministic methods for the simulation of neutron-induced photons for high-resolution gamma-ray spectroscopy applications. RAdiation Detection Scenario Analysis Toolbox (RADSAT), a code which couples deterministic and Monte Carlo transport to perform radiation detection scenario analysis in three dimensions [1], was used as the building block for the methods derived in this work. RADSAT was capable of performing coupled deterministic-Monte Carlo simulations for gamma-only and neutron-only problems. The purpose of this work was to develop the methodology necessary to perform coupled neutron-photon calculations and add this capability to RADSAT. Performing coupled neutron-photon calculations requires four main steps: the deterministic neutron transport calculation, the neutron-induced photon spectrum calculation, the deterministic photon transport calculation, and the Monte Carlo detector response calculation. The necessary requirements for each of these steps were determined. A major challenge in utilizing multigroup deterministic transport methods for neutron-photon problems was maintaining the discrete neutron-induced photon signatures throughout the simulation. Existing coupled neutron-photon cross-section libraries and the methods used to produce neutron-induced photons were unsuitable for high-resolution gamma-ray spectroscopy applications. Central to this work was the development of a method for generating multigroup neutron-photon cross-sections in a way that separates the discrete and continuum photon emissions so the neutron-induced photon signatures were preserved. The RADSAT-NG cross-section library was developed as a specialized multigroup neutron-photon cross-section set for the simulation of high-resolution gamma-ray spectroscopy applications. The methodology and cross sections were tested using code-to-code comparison with MCNP5 [2] and NJOY [3]. A simple benchmark geometry was used for all cases compared with MCNP. The geometry consists of a cubical sample with a 252Cf neutron source on one side and a HPGe gamma-ray spectrometer on the opposing side. Different materials were examined in the cubical sample: polyethylene (C2H4), P, N, O, and Fe. The cross sections for each of the materials were compared to cross sections collapsed using NJOY. Comparisons of the volume-averaged neutron flux within the sample, volume-averaged photon flux within the detector, and high-purity gamma-ray spectrometer response (only for polyethylene) were completed using RADSAT and MCNP. The code-to-code comparisons show promising results for the coupled Monte Carlo-deterministic method. The RADSAT-NG cross-section production method showed good agreement with NJOY for all materials considered although some additional work is needed in the resonance region and in the first and last energy bin. Some cross section discrepancies existed in the lowest and highest energy bin, but the overall shape and magnitude of the two methods agreed. For the volume-averaged photon flux within the detector, typically the five most intense lines agree to within approximately 5% of the MCNP calculated flux for all of materials considered. The agreement in the code-to-code comparisons cases demonstrates a proof-of-concept of the method for use in RADSAT for coupled neutron-photon problems in high-resolution gamma-ray spectroscopy applications. One of the primary motivators for using the coupled method over pure Monte Carlo method is the potential for significantly lower computational times. For the code-to-code comparison cases, the run times for RADSAT were approximately 25--500 times shorter than for MCNP, as shown in Table 1. This was assuming a 40 mCi 252Cf neutron source and 600 seconds of "real-world" measurement time. The only variance reduction technique implemented in the MCNP calculation was forward biasing of the source toward the sample target. Improved MCNP runtimes could be achieved with the addition of more advanced variance reduction techniques.

The seroprevalence of West Nile Virus in Israel: A nationwide cross sectional study

PubMed Central

Shohat, Tamy; Kaufman, Zalman; Mannasse, Batya; Shinar, Eilat; Amichay, Doron; Barak, Mira; Ben-Dor, Anat; Bar Haim, Adina; Cohen, Daniel; Mendelson, Ella; Lustig, Yaniv

2017-01-01

West Nile Virus (WNV) is endemic in Israel, affecting yearly 40–160 individuals. Israel is located on a central migratory path between Africa and Eurasia and most West Nile Fever (WNF) cases reported in recent years were among residents of the coastal plain. The aim of the study was to evaluate the seroprevalence of WNV among the Israeli population and to assess correlates for WNV infection. A cross-sectional nationwide serologic survey was conducted using 3,145 serum samples collected by the national Israeli serum bank during 2011–2014, representing all age and population groups in Israel. Prevalence rates of WNV IgG antibodies were determined. Logistic regressions models were applied to assess the associations between demographic characteristics and WNV seropositivity. 350 samples were positive to WNV (11.1%; 95%CI: 10.0–12.3%). In the multivariable analysis, there was a significant association between seropositivity and the Arab population group vs. Jews and others (OR = 1.86, 95%CI: 1.37–2.52), the time lived in Israel [50–59 years vs. 0–9 years; OR = 10.80 (95%CI: 1.03–113.46) and ≥60 years vs. 0–9 years; OR = 14.00 (1.32–148.31)] residence area] Coastal Plain, Inland Plain (Shfela) and Great Rift Valley vs. Upper Galilee; OR = 2.24 (95%CI: 1.37–3.65), OR = 2.18 (95%CI: 1.18–4.03), OR = 1.90 (95%CI: 1.10–3.30), respectively [and rural vs. urban settlement (OR = 1.65, 95%CI: 1.26–2.16). People, who reside in the Coastal Plain, Inland Plain and Great Rift Valley, should be aware of the risk of contracting WNV and reduce exposure to mosquito bites, using insect repellents, and wearing protective clothing. The Ministry of Environmental Protection should be active in reducing the mosquito population by eliminating sources of standing water, a breeding ground for mosquitoes. PMID:28622360

Relationship between blastocoel cell-free DNA and day-5 blastocyst morphology.

PubMed

Rule, Kiersten; Chosed, Renee J; Arthur Chang, T; David Wininger, J; Roudebush, William E

2018-06-04

Cell-free DNA (cfDNA) which is present in the blastocoel cavity of embryos is believed to result from physiological apoptosis during development. This study assessed cfDNA content and caspase-3 protease activity in day-5 IVF blastocysts to determine if there was a correlation with embryo morphology. Day-5 IVF blastocysts were scored according to the Gardner and Schoolcraft system (modified to generate a numerical value) and cfDNA was collected following laser-induced blastocoel collapsing prior to cryopreservation in 25 μL of media. cfDNA was quantified via fluorospectrometry and apoptotic activity was assessed via a caspase-3 protease assay using a fluorescent peptide substrate. Data were compared by linear regression. A total of 32 embryos were evaluated. There was a significant (p < 0.01) and positive correlation (cfDNA = 104.753 + (11.281 × score); R 2  = 0.200) between embryo score and cfDNA content. A significant (p < 0.05) and positive correlation (cfDNA = 115.9 + (0.05 × caspase-3); R 2 = 0.128) was observed between caspase-3 activity and cfDNA levels. There was no significant relationship between caspase-3 activity and embryo morphology score. This study provides further evidence that cfDNA is present in blastocoel fluid, can be quantified, and positively correlates with embryonic morphology. There is also evidence that at least a portion of the cfDNA present is from intracellular contents of embryonic cells that underwent apoptosis. Additional studies are warranted to determine other physiological sources of the cfDNA in blastocyst fluid and to determine the relationship with cfDNA content, embryo morphology, and chromosomal ploidy status plus implantation potential.

Birth preparedness and complication readiness among rural women of reproductive age in Abeshige district, Guraghe zone, SNNPR, Ethiopia

PubMed Central

Zepre, Kebebush; Kaba, Mirgissa

2017-01-01

Background Birth preparedness and complication readiness (BPCR) is a strategy that helps women to consider all available maternal health care services during pregnancy and prepare for potential complications. Federal Ministry of Health in Ethiopia has taken steps to roll out the strategy at community level. Yet, women in rural communities still do not make use of available services to avoid complications in connection to pregnancy and delivery. Objective This study aims to assess the current BPCR practice and determine associated factors among rural women of reproductive age in Abeshige district, Guraghe zone, SNNPR, Ethiopia. Methods A community-based cross-sectional study was carried out from February to March 2015. A total of 454 women were randomly selected and interviewed using pretested structured questionnaires, while opinion leaders, health extension workers, and selected women in the community were engaged in in-depth interviews and focus group discussions, using checklists prepared to guide the interviews. Data from different sources were analyzed, triangulated, and interpreted to respond to the objectives. Results Thirty-seven percent of the respondents were found to have prepared for birth and its complications. BPCR was higher among women who lived within a 1-hour walk from a health center (adjusted odds ratio [AOR] =3.51, 95% confidence interval [CI]: 1.78, 36.79) and who were aware of the danger signs of pregnancy (AOR =1.72, 95% CI: 1.78, 2.94) and postpartum complications (AOR =2.32, 95% CI: 1.32, 4.21). A major source of information was found to be health extension workers and one-to-five women networks (AOR =2.81, 95% CI: 1.34, 6.21) and (AOR =2.52, 95% CI: 1.17, 5.54), respectively. Qualitative finding revealed that lack of transportation and concern over cost of services are key barriers to BPCR. Conclusion BPCR in Abeshige was found to be relatively low, calling for more interventions beyond mere awareness. Availing transportation services and ensuring services free of charge would help in improving BPCR in the study area. PMID:28053557

Birth preparedness and complication readiness among rural women of reproductive age in Abeshige district, Guraghe zone, SNNPR, Ethiopia.

PubMed

Zepre, Kebebush; Kaba, Mirgissa

2017-01-01

Birth preparedness and complication readiness (BPCR) is a strategy that helps women to consider all available maternal health care services during pregnancy and prepare for potential complications. Federal Ministry of Health in Ethiopia has taken steps to roll out the strategy at community level. Yet, women in rural communities still do not make use of available services to avoid complications in connection to pregnancy and delivery. This study aims to assess the current BPCR practice and determine associated factors among rural women of reproductive age in Abeshige district, Guraghe zone, SNNPR, Ethiopia. A community-based cross-sectional study was carried out from February to March 2015. A total of 454 women were randomly selected and interviewed using pretested structured questionnaires, while opinion leaders, health extension workers, and selected women in the community were engaged in in-depth interviews and focus group discussions, using checklists prepared to guide the interviews. Data from different sources were analyzed, triangulated, and interpreted to respond to the objectives. Thirty-seven percent of the respondents were found to have prepared for birth and its complications. BPCR was higher among women who lived within a 1-hour walk from a health center (adjusted odds ratio [AOR] =3.51, 95% confidence interval [CI]: 1.78, 36.79) and who were aware of the danger signs of pregnancy (AOR =1.72, 95% CI: 1.78, 2.94) and postpartum complications (AOR =2.32, 95% CI: 1.32, 4.21). A major source of information was found to be health extension workers and one-to-five women networks (AOR =2.81, 95% CI: 1.34, 6.21) and (AOR =2.52, 95% CI: 1.17, 5.54), respectively. Qualitative finding revealed that lack of transportation and concern over cost of services are key barriers to BPCR. BPCR in Abeshige was found to be relatively low, calling for more interventions beyond mere awareness. Availing transportation services and ensuring services free of charge would help in improving BPCR in the study area.

Hurdles to herd immunity: Distrust of government and vaccine refusal in the US, 2002-2003.

PubMed

Lee, Charlotte; Whetten, Kathryn; Omer, Saad; Pan, William; Salmon, Daniel

2016-07-25

High rates of nonmedical exemptions (NMEs) from required childhood vaccinations have contributed to outbreaks of vaccine-preventable diseases, such as measles and pertussis. Understanding the parental decision to obtain an NME could help health professionals and public health programs improve vaccination rates in areas with high vaccine refusal. Using a 2002-2003 multi-state survey of parents of school age children (​n=2445), this study found that parental distrust of the government and of healthcare providers is a significant factor related to a number of vaccine-related beliefs and behaviors. The odds that parents who distrust the government have seen a complementary/alternative medicine (CAM) provider were 2.11 times greater than those of parents who trust the government (70.1% vs 52.6%; OR, 2.11; 95% CI, 1.59-2.84; P<0.01). Parents who distrust the government had increased odds of trusting vaccine information from CAM providers compared to trusting parents (57.9% vs 46.3%; OR, 1.53; 95% CI, 1.16-2.01; P<0.01). Parents who distrust the government also had increased odds of distrusting vaccine information acquired at their healthcare providers' offices (12.6% vs 4.7%; OR, 2.64; 95% CI, 1.64-4.24; P<0.01). Distrustful parents had increased odds of thinking government sources of information about vaccines were unreliable, categorizing the CDC, the Food and Drug Administration (FDA), or local and state health departments as poor or very poor sources (distrust government vs trust government: 25.2% vs 11.7%; OR, 2.39; 95% CI, 1.70-3.36; P<0.01; distrust healthcare providers vs trust healthcare providers: 24.4% vs 11.4%; OR, 2.44; 95% CI, 1.75-3.38; P<0.01). These findings indicate that distrustful parent populations may need to be reached through modalities outside of traditional government and healthcare provider communications. Research into new and more effective techniques for delivering pro-vaccine messages is warranted. Copyright © 2016 Elsevier Ltd. All rights reserved.

Association of Cell-Free DNA Tumor Fraction and Somatic Copy Number Alterations With Survival in Metastatic Triple-Negative Breast Cancer

PubMed Central

Stover, Daniel G.; Parsons, Heather A.; Ha, Gavin; Freeman, Samuel S.; Barry, William T.; Guo, Hao; Choudhury, Atish D.; Gydush, Gregory; Reed, Sarah C.; Rhoades, Justin; Rotem, Denisse; Hughes, Melissa E.; Dillon, Deborah A.; Partridge, Ann H.; Wagle, Nikhil; Krop, Ian E.; Getz, Gad; Golub, Todd R.; Love, J. Christopher; Winer, Eric P.; Tolaney, Sara M.; Lin, Nancy U.

2018-01-01

Purpose Cell-free DNA (cfDNA) offers the potential for minimally invasive genome-wide profiling of tumor alterations without tumor biopsy and may be associated with patient prognosis. Triple-negative breast cancer (TNBC) is characterized by few mutations but extensive somatic copy number alterations (SCNAs), yet little is known regarding SCNAs in metastatic TNBC. We sought to evaluate SCNAs in metastatic TNBC exclusively via cfDNA and determine if cfDNA tumor fraction is associated with overall survival in metastatic TNBC. Patients and Methods In this retrospective cohort study, we identified 164 patients with biopsy-proven metastatic TNBC at a single tertiary care institution who received prior chemotherapy in the (neo)adjuvant or metastatic setting. We performed low-coverage genome-wide sequencing of cfDNA from plasma. Results Without prior knowledge of tumor mutations, we determined tumor fraction of cfDNA for 96.3% of patients and SCNAs for 63.9% of patients. Copy number profiles and percent genome altered were remarkably similar between metastatic and primary TNBCs. Certain SCNAs were more frequent in metastatic TNBCs relative to paired primary tumors and primary TNBCs in publicly available data sets The Cancer Genome Atlas and METABRIC, including chromosomal gains in drivers NOTCH2, AKT2, and AKT3. Prespecified cfDNA tumor fraction threshold of ≥ 10% was associated with significantly worse metastatic survival (median, 6.4 v 15.9 months) and remained significant independent of clinicopathologic factors (hazard ratio, 2.14; 95% CI, 1.4 to 3.8; P < .001). Conclusion We present the largest genomic characterization of metastatic TNBC to our knowledge, exclusively from cfDNA. Evaluation of cfDNA tumor fraction was feasible for nearly all patients, and tumor fraction ≥ 10% is associated with significantly worse survival in this large metastatic TNBC cohort. Specific SCNAs are enriched and prognostic in metastatic TNBC, with implications for metastasis, resistance, and novel therapeutic approaches. PMID:29298117

Association of Cell-Free DNA Tumor Fraction and Somatic Copy Number Alterations With Survival in Metastatic Triple-Negative Breast Cancer.

PubMed

Stover, Daniel G; Parsons, Heather A; Ha, Gavin; Freeman, Samuel S; Barry, William T; Guo, Hao; Choudhury, Atish D; Gydush, Gregory; Reed, Sarah C; Rhoades, Justin; Rotem, Denisse; Hughes, Melissa E; Dillon, Deborah A; Partridge, Ann H; Wagle, Nikhil; Krop, Ian E; Getz, Gad; Golub, Todd R; Love, J Christopher; Winer, Eric P; Tolaney, Sara M; Lin, Nancy U; Adalsteinsson, Viktor A

2018-02-20

Purpose Cell-free DNA (cfDNA) offers the potential for minimally invasive genome-wide profiling of tumor alterations without tumor biopsy and may be associated with patient prognosis. Triple-negative breast cancer (TNBC) is characterized by few mutations but extensive somatic copy number alterations (SCNAs), yet little is known regarding SCNAs in metastatic TNBC. We sought to evaluate SCNAs in metastatic TNBC exclusively via cfDNA and determine if cfDNA tumor fraction is associated with overall survival in metastatic TNBC. Patients and Methods In this retrospective cohort study, we identified 164 patients with biopsy-proven metastatic TNBC at a single tertiary care institution who received prior chemotherapy in the (neo)adjuvant or metastatic setting. We performed low-coverage genome-wide sequencing of cfDNA from plasma. Results Without prior knowledge of tumor mutations, we determined tumor fraction of cfDNA for 96.3% of patients and SCNAs for 63.9% of patients. Copy number profiles and percent genome altered were remarkably similar between metastatic and primary TNBCs. Certain SCNAs were more frequent in metastatic TNBCs relative to paired primary tumors and primary TNBCs in publicly available data sets The Cancer Genome Atlas and METABRIC, including chromosomal gains in drivers NOTCH2, AKT2, and AKT3. Prespecified cfDNA tumor fraction threshold of ≥ 10% was associated with significantly worse metastatic survival (median, 6.4 v 15.9 months) and remained significant independent of clinicopathologic factors (hazard ratio, 2.14; 95% CI, 1.4 to 3.8; P < .001). Conclusion We present the largest genomic characterization of metastatic TNBC to our knowledge, exclusively from cfDNA. Evaluation of cfDNA tumor fraction was feasible for nearly all patients, and tumor fraction ≥ 10% is associated with significantly worse survival in this large metastatic TNBC cohort. Specific SCNAs are enriched and prognostic in metastatic TNBC, with implications for metastasis, resistance, and novel therapeutic approaches.

Intramolecular fluorine migration via four-member cyclic transition states

PubMed

Nguyen; Mayer; Morton

2000-11-17

Gaseous CF(3)(+) interchanges F(+) for O with simple carbonyl compounds. CF(3)(+) reacts with propionaldehyde in the gas phase to produce (CH(3))(2)CF(+) via two competing pathways. Starting with 1-(13)C-propionaldehyde, the major pathway (80%) produces (CH(3))(2)CF(+) with the carbon label in one of the methyl groups. The minor pathway (20%) produces (CH(3))(2)CF(+) with the carbon label in the central position. The relative proportions of these two pathways are measured by (19)F NMR analysis of the neutral CH(3)CF=CH(2) produced by deprotonation of (CH(3))(2)CF(+) at <10(-)(3) Torr in an electron bombardment flow (EBFlow) reactor. Formation of alkene in which carbon is directly bonded to fluorine means that (in the minor product, at least) an F(+) for O transposition occurs via adduct formation followed by 1,3-atom transfer and then isomerization of CH(3)CH(2)CHF(+) to the more stable (CH(3))(2)CF(+). Use of CF(4) as a chemical ionization (CI) reagent gas leads to CF(3)(+) adduct ions for a variety of ketones, in addition to isoelectronic transposition of F(+) for O. Metastable ion decompositions of the adduct ions yield the metathesis products. Decompositions of fluorocycloalkyl cations formed in this manner give evidence for the same kinds of rearrangements as take place in CH(3)CH(2)CHF(+). Density functional calculations confirm that F(+) for O metathesis takes place via addition of CF(3)(+) to the carbonyl oxygen followed by transposition via a four-member cyclic transition state. A computational survey of the effects of different substituents in a series of aldehydes and acyclic ketones reveals no systematic variation of the energy of the transition state as a function of thermochemistry, but the Hammond postulate does appear to be obeyed in terms of progress along the reaction coordinate. Bond lengths corresponding to the central barrier correlate with overall thermochemistry of the F(+) for O interchange, but in a sense opposite to what might have been expected: the transition state becomes more product-like as the metathesis becomes increasingly exothermic. This reversal of the naive interpretation of the Hammond postulate is accounted for by the relative positions of the potential energy wells that precede and follow the central barrier.

Triglyceride synthesis in epididymal adipose tissue: contribution of glucose and non-glucose carbon sources.

PubMed

Bederman, Ilya R; Foy, Steven; Chandramouli, Visvanathan; Alexander, James C; Previs, Stephen F

2009-03-06

The obesity epidemic has generated interest in determining the contribution of various pathways to triglyceride synthesis, including an elucidation of the origin of triglyceride fatty acids and triglyceride glycerol. We hypothesized that a dietary intervention would demonstrate the importance of using glucose versus non-glucose carbon sources to synthesize triglycerides in white adipose tissue. C57BL/6J mice were fed either a low fat, high carbohydrate (HC) diet or a high fat, carbohydrate-free (CF) diet and maintained on 2H2O (to determine total triglyceride dynamics) or infused with [6,6-(2)H]glucose (to quantify the contribution of glucose to triglyceride glycerol). The 2H2O labeling data demonstrate that although de novo lipogenesis contributed approximately 80% versus approximately 5% to the pool of triglyceride palmitate in HC- versus CF-fed mice, the epididymal adipose tissue synthesized approximately 1.5-fold more triglyceride in CF- versus HC-fed mice, i.e. 37+/-5 versus 25+/-3 micromolxday(-1). The [6,6-(2)H]glucose labeling data demonstrate that approximately 69 and approximately 28% of triglyceride glycerol is synthesized from glucose in HC- versus CF-fed mice, respectively. Although these data are consistent with the notion that non-glucose carbon sources (e.g. glyceroneogenesis) can make substantial contributions to the synthesis of triglyceride glycerol (i.e. the absolute synthesis of triglyceride glycerol from non-glucose substrates increased from approximately 8 to approximately 26 micromolxday(-1) in HC- versus CF-fed mice), these observations suggest (i) the importance of nutritional status in affecting flux rates and (ii) the operation of a glycerol-glucose cycle.

Pulmonary function deficits in newborn screened infants with cystic fibrosis managed with standard UK care are mild and transient.

PubMed

Davies, Gwyneth; Stocks, Janet; Thia, Lena P; Hoo, Ah-Fong; Bush, Andrew; Aurora, Paul; Brennan, Lucy; Lee, Simon; Lum, Sooky; Cottam, Philippa; Miles, Joanne; Chudleigh, Jane; Kirkby, Jane; Balfour-Lynn, Ian M; Carr, Siobhán B; Wallis, Colin; Wyatt, Hilary; Wade, Angie

2017-11-01

With the advent of novel designer molecules for cystic fibrosis (CF) treatment, there is huge need for early-life clinical trial outcomes, such as infant lung function (ILF). We investigated the degree and tracking of ILF abnormality during the first 2 years of life in CF newborn screened infants.Forced expiratory volume in 0.5 s (FEV 0.5 ), lung clearance index (LCI) and plethysmographic functional residual capacity were measured at ∼3 months, 1 year and 2 years in 62 infants with CF and 34 controls.By 2 years there was no significant difference in FEV 0.5 z-score between CF and controls, whereas mean LCI z-score was 0.81 (95% CI 0.45-1.17) higher in CF. However, there was no significant association between LCI z-score at 2 years with either 3-month or 1-year results. Despite minimal average group changes in any ILF outcome during the second year of life, marked within-subject changes occurred. No child had abnormal LCI or FEV 0.5 on all test occasions, precluding the ability to identify "high-risk" infants in early life.In conclusion, changes in lung function are mild and transient during the first 2 years of life in newborn screened infants with CF when managed according to a standardised UK treatment protocol. Their potential role in tracking disease to later childhood will be ascertained by ongoing follow-up. Copyright ©ERS 2017.

Prompt Neutron Time Decay in Single HEU and DU Metal Annular Storage Castings

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pena, Kirsten E; McConchie, Seth M; Mihalczo, John T

2010-01-01

Previous measurements of highly enriched uranium (HEU) storage castings performed by Oak Ridge National Laboratory (ORNL) at the Y-12 National Security Complex showed a prompt neutron time decay that is not exponential. These measurements showed that multiple time constants originating from multiplication, time-of-flight, scattering in the assembly and room return could be associated with this prompt neutron decay. In this work, the contribution not associated with neutron multiplication was investigated via measurements with a depleted uranium (DU) casting. The measurements at ORNL used an annular (5.0-in OD, 3.5-in ID, 6.0-in H) DU casting with a time-tagged 252Cf source, centered verticallymore » on the axis, and four closely coupled 1 1 6-in.-long plastic scintillators with -in.- thick lead shielding adjacent to the outer surface of the casting. This setup was identical to the configuration used in the previously performed measurements with HEU castings at Y-12. The time correlation between fission events and detections in the plastic scintillators was measured, as well as the time distribution of coincidences between multiple detectors within a 512-ns time window. The measurement results were then compared to MCNP-PoliMi calculations and the previous HEU measurements. Time constants from decay fits to the HEU and DU data were compared to characterize the contributions resulting from multiplication, time-of-flight, and scattering.« less

CHICO2, a two-dimensional pixelated parallel-plate avalanche counter

DOE PAGES

Wu, C. Y.; Cline, D.; Hayes, A.; ...

2016-01-27

CHICO 2 (Compact Heavy Ion COunter), is a large solid-angle, charged-particle detector array developed to provide both θ and Φ angle resolutions matching those of GRETINA (Gamma-Ray Energy Tracking In-beam Nuclear Array). CHICO 2 was successfully tested at the Argonne National Laboratory where it was fielded as an auxiliary detector with GRETINA for γ-ray spectroscopic studies of nuclei using a 252Cf spontaneous fission source, stable beams, and radioactive beams from CARIBU. In field tests of the 72,76Ge beams on a 0.5 mg/cm 2208Pb target at the sub-barrier energy, CHICO 2 provided charged-particle angle resolutions (FWHM) of 1.55° in θ andmore » 2.47° in Φ. This achieves the design goal for both coordinates assuming a beam-spot size (>3 mm) and the target thickness (>0.5 mg/cm 2). The combined angular resolution of GRETINA/CHICO 2 resulted in a Doppler-shift corrected energy resolution of 0.60% for 1 MeV coincident de-excitation γ-rays. This is nearly a factor of two improvements in resolution and sensitivity compared to Gammasphere/CHICO. Kinematically-coincident detection of scattered ions by CHICO 2 still maintains the mass resolution (ΔM/M) of ~5% that enhanced isolation of scattered weak beams of interest from scattered contaminant beams.« less

Study of sampling rate influence on neutron-gamma discrimination with stilbene coupled to a silicon photomultiplier.

PubMed

Zhang, Jinglong; Moore, Michael E; Wang, Zhonghai; Rong, Zhou; Yang, Chaowen; Hayward, Jason P

2017-10-01

Choosing a digitizer with an appropriate sampling rate is often a trade-off between performance and economy. The influence of sampling rates on the neutron-gamma Pulse Shape Discrimination (PSD) with a solid stilbene scintillator coupled to a Silicon Photomultiplier was investigated in this work. Sampling rates from 125MSPS to 2GSPS from a 10-bit digitizer were used to collect detector pulses produced by the interactions of a Cf-252 source. Due to the decreased signal-to-noise ratio (SNR), the PSD performance degraded with reduced sampling rates. The reason of PSD performance degradation was discussed. Then, an efficient combination of filtering and digital signal processing (DSP) was then applied to suppress the timing noise and electronic background noise. The results demonstrate an improved PSD performance especially at low sampling rates, down to 125MSPS. Using filtering and DSP, the ascribed Figure of Merit (FOM) at 125keV ee (± 10keV ee ) increased from 0.95 to 1.02 at 125MSPS. At 300keV ee and above, all the FOMs are better than 2.00. Our study suggests that 250MSPS is a good enough sampling rate for neutron-gamma discrimination in this system in order to be sensitive to neutrons at and above ~ 125keV ee . Copyright © 2017 Elsevier Ltd. All rights reserved.

Facile one-pot fabrication of nano-Fe3O4/carboxyl-functionalized baker's yeast composites and their application in methylene blue dye adsorption

NASA Astrophysics Data System (ADS)

Du, Zongjun; Zhang, Yue; Li, Zhengjie; Chen, Hui; Wang, Ying; Wang, Guangtu; Zou, Ping; Chen, Huaping; Zhang, Yunsong

2017-01-01

Nano-Fe3O4/carboxyl-functionalized baker's yeast composites (NF/CF-BYs) were prepared for the first time based on the ultrasonic cavitation assisted oxygen implosion method using single Fe2+ as iron source. The series of characterization analysis results showed that the obtained NF/CF-BYs had not only the superparamagnetic properties of nano-Fe3O4, but their surface also had plenty of functional groups (especially carboxyl groups) introduced by strong oxidization. The adsorption properties of NF/CF-BYs for methylene blue (MB) were also evaluated. The results displayed that the uptakes of NF/CF-BYs for MB were higher than that of pristine baker's yeast (P-BYs), and the adsorption process was followed by the pseudo-second-order kinetic model and Langmuir isotherm. The maximum adsorption capacity of NF/CF-BYs for MB was estimated to be 141.75 mg g-1 at pH 6. The regeneration efficiency of the obtained NF/CF-BYs was attained to be more than 90%.

Acute and Short-term Toxic Effects of Conventionally Fractionated vs Hypofractionated Whole-Breast Irradiation: A Randomized Clinical Trial.

PubMed

Shaitelman, Simona F; Schlembach, Pamela J; Arzu, Isidora; Ballo, Matthew; Bloom, Elizabeth S; Buchholz, Daniel; Chronowski, Gregory M; Dvorak, Tomas; Grade, Emily; Hoffman, Karen E; Kelly, Patrick; Ludwig, Michelle; Perkins, George H; Reed, Valerie; Shah, Shalin; Stauder, Michael C; Strom, Eric A; Tereffe, Welela; Woodward, Wendy A; Ensor, Joe; Baumann, Donald; Thompson, Alastair M; Amaya, Diana; Davis, Tanisha; Guerra, William; Hamblin, Lois; Hortobagyi, Gabriel; Hunt, Kelly K; Buchholz, Thomas A; Smith, Benjamin D

2015-10-01

The most appropriate dose fractionation for whole-breast irradiation (WBI) remains uncertain. To assess acute and 6-month toxic effects and quality of life (QOL) with conventionally fractionated WBI (CF-WBI) vs hypofractionated WBI (HF-WBI). Unblinded randomized trial of CF-WBI (n = 149; 50.00 Gy/25 fractions + boost [10.00-14.00 Gy/5-7 fractions]) vs HF-WBI (n = 138; 42.56 Gy/16 fractions + boost [10.00-12.50 Gy/4-5 fractions]) following breast-conserving surgery administered in community-based and academic cancer centers to 287 women 40 years or older with stage 0 to II breast cancer for whom WBI without addition of a third field was recommended; 76% of study participants (n = 217) were overweight or obese. Patients were enrolled from February 2011 through February 2014 and observed for a minimum of 6 months. Administration of CF-WBI or HF-WBI. Physician-reported acute and 6-month toxic effects using National Cancer Institute Common Toxicity Criteria, and patient-reported QOL using the Functional Assessment of Cancer Therapy for Patients with Breast Cancer (FACT-B). All analyses were intention to treat, with outcomes compared using the χ2 test, Cochran-Armitage test, and ordinal logistic regression. Of 287 participants, 149 were randomized to CF-WBI and 138 to HF-WBI. Treatment arms were well matched for baseline characteristics, including FACT-B total score (HF-WBI, 120.1 vs CF-WBI, 118.8; P = .46) and individual QOL items such as somewhat or more lack of energy (HF-WBI, 38% vs CF-WBI, 39%; P = .86) and somewhat or more trouble meeting family needs (HF-WBI, 10% vs CF-WBI, 14%; P = .54). Maximum physician-reported acute dermatitis (36% vs 69%; P < .001), pruritus (54% vs 81%; P < .001), breast pain (55% vs 74%; P = .001), hyperpigmentation (9% vs 20%; P = .002), and fatigue (9% vs 17%; P = .02) during irradiation were lower in patients randomized to HF-WBI. The rate of overall grade 2 or higher acute toxic effects was less with HF-WBI than with CF-WBI (47% vs 78%; P < .001). Six months after irradiation, physicians reported less fatigue in patients randomized to HF-WBI (0% vs 6%; P = .01), and patients randomized to HF-WBI reported less lack of energy (23% vs 39%; P < .001) and less trouble meeting family needs (3% vs 9%; P = .01). Multivariable regression confirmed the superiority of HF-WBI in terms of patient-reported lack of energy (odds ratio [OR], 0.39; 95% CI, 0.24-0.63) and trouble meeting family needs (OR, 0.34; 95% CI, 0.16-0.75). Treatment with HF-WBI appears to yield lower rates of acute toxic effects than CF-WBI as well as less fatigue and less trouble meeting family needs 6 months after completing radiation therapy. These findings should be communicated to patients as part of shared decision making. clinicaltrials.gov Identifier: NCT01266642.

Representing Simple Geometry Types in NetCDF-CF

NASA Astrophysics Data System (ADS)

Blodgett, D. L.; Koziol, B. W.; Whiteaker, T. L.; Simons, R.

2016-12-01

The Climate and Forecast (CF) metadata convention is well-suited for representing gridded and point-based observational datasets. However, CF currently has no accepted mechanism for representing simple geometry types such as lines and polygons. Lack of support for simple geometries within CF has unintentionally excluded a broad set of geoscientific data types from NetCDF-CF data encodings. For example, hydrologic datasets often contain polygon watershed catchments and polyline stream reaches in addition to point sampling stations and water management infrastructure. The latter has an associated CF specification. In the interest of supporting all simple geometry types within CF, a working group was formed following an EarthCube workshop on Advancing NetCDF-CF [1] to draft a CF specification for simple geometries: points, lines, polygons, and their associated multi-geometry representations [2]. The draft also includes parametric geometry types such as circles and ellipses. This presentation will provide an overview of the scope and content of the proposed specification focusing on mechanisms for representing coordinate arrays using variable length or continuous ragged arrays, capturing multi-geometries, and accounting for type-specific geometry artifacts such as polygon holes/interiors, node ordering, etc. The concepts contained in the specification proposal will be described with a use case representing streamflow in rivers and evapotranspiration from HUC12 watersheds. We will also introduce Python and R reference implementations developed alongside the technical specification. These in-development, open source Python and R libraries convert between commonly used GIS software objects (i.e. GEOS-based primitives) and their associated simple geometry CF representation. [1] http://www.unidata.ucar.edu/events/2016CFWorkshop/[2] https://github.com/bekozi/netCDF-CF-simple-geometry

Scalable Low-Power Deep Machine Learning with Analog Computation

DTIC Science & Technology

2013-07-19

transimpedance amplifier (TIA) that measures the output current 7 V Cf Vbias MP1 MN1 Vdd = 3 V 2.5 V 2.6 V + − Vox = 4.4 V 0.1 V + − 7 V Cf Vbias MP1 MN1 Vddt... amplifier . The amplifier has Cf as its feedback capacitor and the FG voltage Vfg as its input. The two MUXs at the sources of MP1 and MP2 control the...as a simple operational transconductor amplifier (OTA), converts voltage Vout to output current Iout. Vref determines the nominal voltage of Vout

Seroepidemiology and associated risk factors of Toxoplasma gondii in sheep and goats in Southwestern Ethiopia.

PubMed

Tegegne, Dechassa; Kelifa, Amin; Abdurahaman, Mukarim; Yohannes, Moti

2016-12-09

T.gondii is a global zoonotic disease and is considered as the most neglected tropical disease in sub-Saharan countries. The exact seroepidemiological distribution and risk factors for the infection of food animals and humans in Ethiopia was less studied although, such studies are important. The objective of the current study was to determine the seroprevalence and potential risk factors of T. gondii infection in sheep and goats in Southwestern Ethiopia. Cross sectional study was conducted from November 2014 to March 2015 in South west Ethiopia in four selected districts of Jimma zone (n = 368). Slide agglutination test (Toxo-latex) was used to detect anti-T.gondii antibodies. Logistic regression was used to determine potential risk factors. An overall seroprevalence of 57.60% (212/368; 95% CI: 52.55-62.6) was detected. 58.18% (148/252; 95% CI: 52.75-64.88) and 55.18% (64/116; 95% CI: 46.13-64.23) sero prevalence was found in sheep and goats respectively. Multivariable logistic regression analysis showed that the risk of T. gondii infection was significantly higher in adult sheep and goats [(sheep: Odds Ratio (OR) = 2.5, confidence interval (CI): 1.19-5.23; p = 0.015), (goats: OR = 3.9, confidence interval (CI):1.64-9.41: p = 0.002)] than in young sheep and goats, in female [(sheep: OR = 1.93, CI: 1.11-3.36, p = 0.018, (goats: OR = 2.9, CI: 121-6.93, p = 0.002)] than in males sheep and goats, in Highland [(sheep: OR = 4.57, CI: 1.75-12.66, P = 0.000, (goats: OR = 4.4, CI: 1.75-13.66, p = 0.004)] than sheep and goats from lowland. This study indicates that seroprevalence of latent toxoplasmosis in small ruminants is high, therefore, it is decidedly indispensable to minimize risk factors exposing to the infection like consumption of raw meat as source of infection for humans.

Pulmonary disease in cystic fibrosis: assessment with chest CT at chest radiography dose levels.

PubMed

Ernst, Caroline W; Basten, Ines A; Ilsen, Bart; Buls, Nico; Van Gompel, Gert; De Wachter, Elke; Nieboer, Koenraad H; Verhelle, Filip; Malfroot, Anne; Coomans, Danny; De Maeseneer, Michel; de Mey, Johan

2014-11-01

To investigate a computed tomographic (CT) protocol with iterative reconstruction at conventional radiography dose levels for the assessment of structural lung abnormalities in patients with cystic fibrosis ( CF cystic fibrosis ). In this institutional review board-approved study, 38 patients with CF cystic fibrosis (age range, 6-58 years; 21 patients <18 years and 17 patients >18 years) underwent investigative CT (at minimal exposure settings combined with iterative reconstruction) as a replacement of yearly follow-up posteroanterior chest radiography. Verbal informed consent was obtained from all patients or their parents. CT images were randomized and rated independently by two radiologists with use of the Bhalla scoring system. In addition, mosaic perfusion was evaluated. As reference, the previous available conventional chest CT scan was used. Differences in Bhalla scores were assessed with the χ(2) test and intraclass correlation coefficients ( ICC intraclass correlation coefficient s). Radiation doses for CT and radiography were assessed for adults (>18 years) and children (<18 years) separately by using technical dose descriptors and estimated effective dose. Differences in dose were assessed with the Mann-Whitney U test. The median effective dose for the investigative protocol was 0.04 mSv (95% confidence interval [ CI confidence interval ]: 0.034 mSv, 0.10 mSv) for children and 0.05 mSv (95% CI confidence interval : 0.04 mSv, 0.08 mSv) for adults. These doses were much lower than those with conventional CT (median: 0.52 mSv [95% CI confidence interval : 0.31 mSv, 3.90 mSv] for children and 1.12 mSv [95% CI confidence interval : 0.57 mSv, 3.15 mSv] for adults) and of the same order of magnitude as those for conventional radiography (median: 0.012 mSv [95% CI confidence interval : 0.006 mSv, 0.022 mSv] for children and 0.012 mSv [95% CI confidence interval : 0.005 mSv, 0.031 mSv] for adults). All images were rated at least as diagnostically acceptable. Very good agreement was found in overall Bhalla score ( ICC intraclass correlation coefficient , 0.96) with regard to the severity of bronchiectasis ( ICC intraclass correlation coefficient , 0.87) and sacculations and abscesses ( ICC intraclass correlation coefficient , 0.84). Interobserver agreement was excellent ( ICC intraclass correlation coefficient , 0.86-1). For patients with CF cystic fibrosis , a dedicated chest CT protocol can replace the two yearly follow-up chest radiographic examinations without major dose penalty and with similar diagnostic quality compared with conventional CT.

Australian epidemic strain pseudomonas (AES-1) declines further in a cohort segregated cystic fibrosis clinic.

PubMed

Griffiths, Amanda L; Wurzel, Danielle F; Robinson, Phil J; Carzino, Rosemary; Massie, John

2012-01-01

To evaluate changes in prevalence of an epidemic strain of Pseudomonas aeruginosa (AES-1, Australian epidemic strain, type 1) in a paediatric cystic fibrosis (CF) centre practising cohort segregation, to describe the patients' clinical characteristics at acquisition and observe mortality rates. Cohort segregation was introduced in our paediatric CF clinic January 2000. The prevalence of AES-1 was analysed in 1999, 2002 and 2007. Age at acquisition, lung function, presence of bronchiectasis, hospitalisations, prior P. aeruginosa infection and mortality rates were collected. AES-1 infection was determined by pulse-field-gel-electrophoresis (PFGE) on airway specimen cultures taken three monthly. The prevalence of AES-1 declined from 21% in 1999 to 14% in 2002 (risk difference 7% (95% CI 1,13) p=0.0256) and to 6% in 2007 (risk difference 8% (95% CI 3,13) p=0.0018). New acquisitions after the introduction of cohort segregation were uncommon (10 by 2002 and another 7 by 2007) with a declining incidence of 3.3 cases/year (1999 to 2002) compared to 1.4 cases/year (2002 to 2007). Twenty-two of 32 (69%) deaths between 1999 and 2007 occurred in patients infected with AES-1. Cohort segregation has been associated with reductions in the prevalence of AES-1 in our CF clinic. Mortality was higher in patients infected with AES-1 than other organisms. Copyright © 2011 European Cystic Fibrosis Society. Published by Elsevier B.V. All rights reserved.

Seasonal variation in outdoor, indoor, and personal air pollution exposures of women using wood stoves in the Tibetan Plateau: Baseline assessment for an energy intervention study.

PubMed

Ni, Kun; Carter, Ellison; Schauer, James J; Ezzati, Majid; Zhang, Yuanxun; Niu, Hongjiang; Lai, Alexandra M; Shan, Ming; Wang, Yuqin; Yang, Xudong; Baumgartner, Jill

2016-09-01

Cooking and heating with coal and biomass is the main source of household air pollution in China and a leading contributor to disease burden. As part of a baseline assessment for a household energy intervention program, we enrolled 205 adult women cooking with biomass fuels in Sichuan, China and measured their 48-h personal exposure to fine particulate matter (PM2.5) and carbon monoxide (CO) in winter and summer. We also measured the indoor 48-h PM2.5 concentrations in their homes and conducted outdoor PM2.5 measurements during 101 (74) days in summer (winter). Indoor concentrations of CO and nitrogen oxides (NO, NO2) were measured over 48-h in a subset of ~80 homes. Women's geometric mean 48-h exposure to PM2.5 was 80μg/m(3) (95% CI: 74, 87) in summer and twice as high in winter (169μg/m(3) (95% CI: 150, 190), with similar seasonal trends for indoor PM2.5 concentrations (winter: 252μg/m(3); 95% CI: 215, 295; summer: 101μg/m(3); 95% CI: 91, 112). We found a moderately strong relationship between indoor PM2.5 and CO (r=0.60, 95% CI: 0.46, 0.72), and a weak correlation between personal PM2.5 and CO (r=0.41, 95% CI: -0.02, 0.71). NO2/NO ratios were higher in summer (range: 0.01 to 0.68) than in winter (range: 0 to 0.11), suggesting outdoor formation of NO2 via reaction of NO with ozone is a more important source of NO2 than biomass combustion indoors. The predictors of women's personal exposure to PM2.5 differed by season. In winter, our results show that primary heating with a low-polluting fuel (i.e., electric stove or wood-charcoal) and more frequent kitchen ventilation could reduce personal PM2.5 exposures. In summer, primary use of a gaseous fuel or electricity for cooking and reducing exposure to outdoor PM2.5 would likely have the greatest impacts on personal PM2.5 exposure. Copyright © 2016 Elsevier Ltd. All rights reserved.

Dietary intake of energy-dense, nutrient-poor and nutrient-dense food sources in children with cystic fibrosis.

PubMed

Sutherland, Rosie; Katz, Tamarah; Liu, Victoria; Quintano, Justine; Brunner, Rebecca; Tong, Chai Wei; Collins, Clare E; Ooi, Chee Y

2018-04-30

Prescription of a high-energy, high-fat diet is a mainstay of nutrition management in cystic fibrosis (CF). However, families may be relying on energy-dense, nutrient-poor (EDNP) foods rather than nutrient-dense (ND) foods to meet dietary targets. We aimed to evaluate the relative contribution of EDNP and ND foods to the usual diets of children with CF and identify sociodemographic factors associated with higher EDNP intakes. This is a cross-sectional comparison of children with CF aged 2-18 years and age- and gender-matched controls. Dietary intake was assessed using the Australian Child and Adolescent Eating Survey (ACAES) food frequency questionnaire. Children with CF (n = 80: 37 males; mean age 9.3 years) consumed significantly more EDNP foods than controls (mean age 9.8 years) in terms of both total energy (median [IQR]: 1301 kcal/day (843-1860) vs. 686 kcal/day (480-1032); p < 0.0001), and as a proportion of energy intake (median [IQR]: 44% (34-51) vs. 31% (24-43); p < 0.0001). Although children with CF met their estimated energy requirements (median [IQR]: 158% (124-187) vs. 112% (90-137); p < 0.0001) and their diets were high in fat (median [IQR]: 38% (35-41) vs. 34% (32-36); p < 0.0001), this was largely attributable to EDNP foods. High EDNP intakes (≥10 serves/day) were associated with socioeconomic disadvantage (p = 0.01) and rural residential location (p = 0.03). The energy- and fat-dense CF diet is primarily achieved by overconsumption of EDNP foods, rather than ND sources. This dietary pattern may not be optimal for the future health of children with CF, who are now expected to survive well into adulthood. Copyright © 2018 European Cystic Fibrosis Society. All rights reserved.

Toward achieving flexible and high sensitivity hexagonal boron nitride neutron detectors

NASA Astrophysics Data System (ADS)

Maity, A.; Grenadier, S. J.; Li, J.; Lin, J. Y.; Jiang, H. X.

2017-07-01

Hexagonal boron nitride (h-BN) detectors have demonstrated the highest thermal neutron detection efficiency to date among solid-state neutron detectors at about 51%. We report here the realization of h-BN neutron detectors possessing one order of magnitude enhancement in the detection area but maintaining an equal level of detection efficiency of previous achievement. These 3 mm × 3 mm detectors were fabricated from 50 μm thick freestanding and flexible 10B enriched h-BN (h-10BN) films, grown by metal organic chemical vapor deposition followed by mechanical separation from sapphire substrates. Mobility-lifetime results suggested that holes are the majority carriers in unintentionally doped h-BN. The detectors were tested under thermal neutron irradiation from californium-252 (252Cf) moderated by a high density polyethylene moderator. A thermal neutron detection efficiency of ˜53% was achieved at a bias voltage of 200 V. Conforming to traditional solid-state detectors, the realization of h-BN epilayers with enhanced electrical transport properties is the key to enable scaling up the device sizes. More specifically, the present results revealed that achieving an electrical resistivity of greater than 1014 Ωṡcm and a leakage current density of below 3 × 10-10 A/cm2 is needed to fabricate large area h-BN detectors and provided guidance for achieving high sensitivity solid state neutron detectors based on h-BN.

Occurrence of Pseudomonas aeruginosa in waters: implications for patients with cystic fibrosis (CF).

PubMed

Caskey, S; Stirling, J; Moore, J E; Rendall, J C

2018-06-01

Chronic Pseudomonas aeruginosa infection is associated with increased morbidity and mortality in patients with cystic fibrosis (CF). Current understanding of risk factors for acquisition is limited and so the aim of this study was to examine a large sample of environmental waters from diverse sources. Environmental water samples (n = 7904) from jacuzzis, hydrants, swimming pools, hot tubs, plunge pools, bottled natural mineral water, taps, springs, ice machines, water coolers, bores and showers were examined for the presence of P. aeruginosa. Pseudomonas aeruginosa was detected in 524/7904 (6·6%) waters examined. Hot tubs (51/243; 20·9%), tap water (3/40; 8%) and jacuzzis (432/5811; 7·4%) were the most likely environments where P. aeruginosa was isolated. Pseudomonas aeruginosa was isolated from bottled water (2/67; 3%). Our study highlights the ubiquitous nature of P. aeruginosa in the environment. Given CF patients are frequently counselled to make lifestyle changes to minimize P. aeruginosa exposure, these results have important implications. In particular, the occurrence of P. aeruginosa in tap water highlights the need to disinfect the CF patients' nebulizer after each use. This study examined a large number of water sources (n = 7904) over a 9-year period for the presence of Pseudomonas aeruginosa. The study highlighted that jacuzzis (n = 5811; 7% positive) and hot tubs had the highest occurrence of this organism (n = 243, 21% positive). Patients with cystic fibrosis (CF) are interested in knowing what water environments are likely to be contaminated with this organism, as this bacterium is an important cause of increased morbidity and mortality in such patients. With such information, CF patients and parents may make informed decisions about lifestyle choice and water environment avoidance. © 2018 The Society for Applied Microbiology.

The angular dependence of pulse shape discrimination and detection sensitivity in cylindrical and cubic EJ-309 organic liquid scintillators

NASA Astrophysics Data System (ADS)

Jones, A. R.; Joyce, M. J.

2017-01-01

Liquid scintillators are used widely for neutron detection and for the assay of nuclear materials. However, due to the constituents of the detector and the nitrogen void within the detector cell, usually incorporated to accommodate any expansion that might occur to avoid leakage, fluctuations in detector response have been observed associated with the orientation of the detector when in use. In this work the angular dependence of the pulse-shape discrimination performance in an EJ309 liquid scintillator has been investigated with 252Cf in terms of the separation of γ -ray and neutron events, described quantitatively by the figure-of-merit. A subtle dependence in terms of pulse-shape discrimination is observed. In contrast, a more significant dependence of detection sensitivity with the angle of orientation is evident.

Complementary Feeding and Diarrhea and Respiratory Infection Among HIV-exposed Tanzanian Infants

PubMed Central

Kamenju, P; Liu, E; Hertzmark, E; Spiegelman, D; Kisenge, R.R.; Kupka, R; Aboud, S; Manji, K.P.; Duggan, C; Fawzi, W.W.

2016-01-01

Objective To examine the association between complementary feeding (CF) and risks of diarrhea and acute respiratory infection (ARI) among HIV-exposed infants aged 6–24 months. Design We prospectively employed an Infant and Child Feeding Index (ICFI) to measure CF practices (breastfeeding status, food consistency, dietary diversity, food group frequency and meal frequency). We determined the association of ICFI and each of its components with the risk of diarrhea and ARI. Generalized estimating equations (GEE) were used to estimate the relative risks for morbidity episodes. Setting Dar es Salaam, Tanzania. Subjects 2092 HIV-exposed infants followed from 6 months of age to 24 months of age. Results The ICFI score ranged from 0 to 9; the median score was 6 (Inter-Quartile Range; IQR=4, 7). Low ICFI scores were likely associated with increased risk of dysentery (low vs. high tertile Risk Ratio, RR: 1.40; 95% CI: 0.93, 2.10; P for trend=0.02) and respiratory infection (low vs. high tertile RR: 1.16; 95% CI: 0.96, 1.41; P for trend=0.01). Low dietary diversity scores were likely associated with higher risk of dysentery (low vs. high tertile RR: 1.47; 95% CI: 0.92, 2.35; P for trend=0.03) and respiratory infection (low vs. high tertile RR: 1.41; 95% CI: 1.13, 1.76; P for trend=0.01). Low food consistency scores were associated with higher risk of respiratory infection (RR: 1.77; 95% CI: 1.40, 2.26; P<0.01). Conclusions In this setting, low ICFI, dietary diversity and food consistency scores were likely associated with increased risk of diarrhea and acute respiratory infection among HIV-exposed infants. PMID:27861238

Industrial ion source technology

NASA Technical Reports Server (NTRS)

Kaufman, H. R.; Robinson, R. S.

1979-01-01

In reactive ion etching of Si, varying amounts of O2 were added to the CF4 background. The experimental results indicated an etch rate less than that for Ar up to an O2 partial pressure of about .00006 Torr. Above this O2 pressure, the etch rate with CF4 exceeded that with Ar alone. For comparison the random arrival rate of O2 was approximately equal to the ion arrival rate at a partial pressure of about .00002 Torr. There were also ion source and ion pressure gauge maintenance problems as a result of the use of CF4. Large scale (4 sq cm) texturing of Si was accomplished using both Cu and stainless steel seed. The most effective seeding method for this texturing was to surround the sample with large inclined planes. Designing, fabricating, and testing a 200 sq cm rectangular beam ion source was emphasized. The design current density was 6 mA/sq cm with 500 eV argon ions, although power supply limitations permitted operation to only 2 mA/sq cm. The use of multiple rectangular beam ion sources for continuous processing of wider areas than would be possible with a single source was also studied. In all cases investigated, the most uniform coverage was obtained with 0 to 2 cm beam overlay. The maximum departure from uniform processing at optimum beam overlap was found to be +15%.

U.S. EPA, Pesticide Product Label, GRO-WELL PRE-VENT PRE-EMERGENT CRABGRASS CONTROL WITH FERTILIZER, 04/19/1971

EPA Pesticide Factsheets

2011-04-14

... 1'1 -. ' \\ i. ., I r J - • :- • f : , .. # I """;. I .. ". 4l ,-, "'J' • • r.~ i 1.·'1 '. nrr· c,;f r· 'I' C"I",',' I" .111 ~L ..... V.¥,i. _ .. ,.. t'-_ _"'-"~ r·, , f'. f . r !: ( ...

48 CFR 227.7203-17 - Overseas contracts with foreign sources.

Code of Federal Regulations, 2013 CFR

2013-10-01

... COPYRIGHTS Rights in Computer Software and Computer Software Documentation 227.7203-17 Overseas contracts with foreign sources. (a) The clause at 252.227-7032, Rights in Technical Data and Computer Software... Noncommercial Computer Software and Noncommercial Computer Software Documentation, when the Government requires...

48 CFR 227.7203-17 - Overseas contracts with foreign sources.

Code of Federal Regulations, 2010 CFR

2010-10-01

... COPYRIGHTS Rights in Computer Software and Computer Software Documentation 227.7203-17 Overseas contracts with foreign sources. (a) The clause at 252.227-7032, Rights in Technical Data and Computer Software... Noncommercial Computer Software and Noncommercial Computer Software Documentation, when the Government requires...

48 CFR 227.7203-17 - Overseas contracts with foreign sources.

Code of Federal Regulations, 2014 CFR

2014-10-01

... COPYRIGHTS Rights in Computer Software and Computer Software Documentation 227.7203-17 Overseas contracts with foreign sources. (a) The clause at 252.227-7032, Rights in Technical Data and Computer Software... Noncommercial Computer Software and Noncommercial Computer Software Documentation, when the Government requires...

48 CFR 227.7203-17 - Overseas contracts with foreign sources.

Code of Federal Regulations, 2011 CFR

2011-10-01

... COPYRIGHTS Rights in Computer Software and Computer Software Documentation 227.7203-17 Overseas contracts with foreign sources. (a) The clause at 252.227-7032, Rights in Technical Data and Computer Software... Noncommercial Computer Software and Noncommercial Computer Software Documentation, when the Government requires...

48 CFR 227.7203-17 - Overseas contracts with foreign sources.

Code of Federal Regulations, 2012 CFR

2012-10-01

... COPYRIGHTS Rights in Computer Software and Computer Software Documentation 227.7203-17 Overseas contracts with foreign sources. (a) The clause at 252.227-7032, Rights in Technical Data and Computer Software... Noncommercial Computer Software and Noncommercial Computer Software Documentation, when the Government requires...

Assessment of heavy metal accumulation in two species of Tillandsia in relation to atmospheric emission sources in Argentina.

PubMed

Wannaz, Eduardo D; Carreras, Hebe A; Pérez, Carlos A; Pignata, María L

2006-05-15

The ability of Tillandsia capillaris Ruiz and Pav. f. capillaris and Tillandsia permutata A. Cast. to accumulate heavy metals was evaluated in relation to potential atmospheric emission sources in Argentina. The sampling areas (n=38) were chosen in the province of Córdoba, located in the center of Argentina, and categorized according to land use, anthropogenic activities and/or distance to potential heavy metal emission sources. In each sampling site, pools of 40-50 individuals of each species were made from plants collected along the four cardinal directions. The concentrations of V, Mn, Fe, Co, Ni, Cu, Zn, Pb and Br of these samples were measured by Total Reflection X-Ray Fluorescence (TXRF) analysis with Synchrotron Radiation. Each species was submitted to a cluster analysis in order to discriminate different groups of heavy metals as tracers of natural or anthropogenic sources. A Contamination Factor (CF) was calculated using the concentrations of the elements in each sample compared to their concentrations in the control samples. Finally, the rank coefficients of correlation between the CFs and the categorical variables characteristic of each site (land use and anthropogenic load) were analyzed. A positive correlation was found for T. capillaris between the CFs of V, Mn, Co, Ni, Cu and Zn and the urban-industrial category, whereas the CF values for Zn and Pb were positively correlated with the road category. In T. permutata there was a positive correlation between the CF of Zn and the urban-industrial category and the CF of Pb with the road category. We therefore conclude that T. capillaris is a more efficient metal accumulator in passive biomonitoring studies.

Neutron Detection with Centrifugally-Tensioned Metastable Fluid Detectors (CMTFD)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Xu, Y.; Smagacz, P.; Lapinskas, J.

2006-07-01

Tensioned metastable liquid states at room temperature were utilized to display sensitivity to impinging nuclear radiation, that manifests itself via audio-visual signals that one can see and hear. A centrifugally-tensioned metastable fluid detector (CTMFD), a diamond shaped spinning device rotating about its axis, was used to induce tension states, i.e. negative (sub-vacuum) pressures in liquids. In this device, radiation induced cavitation is audible due to liquid fracture and is visible from formed bubbles, so called hearing and seeing radiation. This type of detectors is selectively insensitive to Gamma rays and associated indication devices could be extremely simple, reliable and inexpensive.more » Furthermore, any liquids with large neutron interaction cross sections could be good candidates. Two liquids, isopentane and methanol, were tested with three neutron sources of Cf-252, PuBe and Pulsed Neutron Generator (PNG) under various configurations of neutron spectra and fluxes. The neutron count rates were measured using a liquid scintillation detector. The CTMFD was operated at preset values of rotating frequency and a response time was recorded when a cavitation occurred. Other parameters, including ambient temperature, ramp rate, delay time between two consecutive cavitations, were kept constant. The distance between the menisci of the liquid in the CTMFD was measured before and after each experiment. In general, the response of liquid molecules in a CTMFD varies with the neutron spectrum and flux. The response time follows an exponential trend with negative pressures for a given neutron count rate and spectra conditions. Isopentane was found to exhibit lower tension thresholds than methanol. On the other hand, methanol offered a larger tension metastability state variation for the various types of neutron sources, indicating the potential for offering significantly better energy resolution abilities for spectroscopic applications. (authors)« less

Measurement of theta13 in the double Chooz experiment

NASA Astrophysics Data System (ADS)

Yang, Guang

Neutrino oscillation has been established for over a decade. The mixing angle theta13 is one of the parameters that is most difficult to measure due to its small value. Currently, reactor antineutrino experiments provide the best knowledge of theta13, using the electron antineutrino disappearance phenomenon. The most compelling advantage is the high intensity of the reactor antineutrino rate. The Double Chooz experiment, located on the border of France and Belgium, is such an experiment, which aims to have one of the most precise theta 13 measurements in the world. Double Chooz has a single-detector phase and a double-detector phase. For the single-detector phase, the limit of the theta 13 sensitivity comes mostly from the reactor flux. However, the uncertainty on the reactor flux is highly suppressed in the double-detector phase. Oscillation analyses for the two phases have different strategies but need similar inputs, including background estimation, detection systematics evaluation, energy reconstruction and so on. The Double Chooz detectors are filled with gadolinium (Gd) doped liquid scintillator and use the inverse beta decay (IBD) signal so that for each phase, there are two independent theta13 measurements based on different neutron capturer (Gd or hydrogen). Multiple oscillation analyses are performed to provide the best 13 results. In addition to the 13 measurement, Double Chooz is also an excellent \\playground" to do diverse physics research. For example, a 252Cf calibration source study has been done to understand the spontaneous decay of this radioactive source. Further, Double Chooz also has the ability to do a sterile neutrino search in a certain mass region. Moreover, some new physics ideas can be tested in Double Chooz. In this thesis, the detailed methods to provide precise theta13 measurement will be described and the other physics topics will be introduced.

Design of a transportable high efficiency fast neutron spectrometer

DOE PAGES

Roecker, C.; Bernstein, A.; Bowden, N. S.; ...

2016-04-12

A transportable fast neutron detection system has been designed and constructed for measuring neutron energy spectra and flux ranging from tens to hundreds of MeV. The transportability of the spectrometer reduces the detector-related systematic bias between different neutron spectra and flux measurements, which allows for the comparison of measurements above or below ground. The spectrometer will measure neutron fluxes that are of prohibitively low intensity compared to the site-specific background rates targeted by other transportable fast neutron detection systems. To measure low intensity high-energy neutron fluxes, a conventional capture-gating technique is used for measuring neutron energies above 20 MeV andmore » a novel multiplicity technique is used for measuring neutron energies above 100 MeV. The spectrometer is composed of two Gd containing plastic scintillator detectors arranged around a lead spallation target. To calibrate and characterize the position dependent response of the spectrometer, a Monte Carlo model was developed and used in conjunction with experimental data from gamma ray sources. Multiplicity event identification algorithms were developed and used with a Cf-252 neutron multiplicity source to validate the Monte Carlo model Gd concentration and secondary neutron capture efficiency. The validated Monte Carlo model was used to predict an effective area for the multiplicity and capture gating analyses. For incident neutron energies between 100 MeV and 1000 MeV with an isotropic angular distribution, the multiplicity analysis predicted an effective area of 500 cm 2 rising to 5000 cm 2. For neutron energies above 20 MeV, the capture-gating analysis predicted an effective area between 1800 cm 2 and 2500 cm 2. As a result, the multiplicity mode was found to be sensitive to the incident neutron angular distribution.« less

Digital fast neutron radiography of steel reinforcing bar in concrete

NASA Astrophysics Data System (ADS)

Mitton, K.; Jones, A.; Joyce, M. J.

2014-12-01

Neutron imaging has previously been used in order to test for cracks, degradation and water content in concrete. However, these techniques often fall short of alternative non-destructive testing methods, such as γ-ray and X-ray imaging, particularly in terms of resolution. Further, thermal neutron techniques can be compromised by the significant expense associated with thermal neutron sources of sufficient intensity to yield satisfactory results that can often precipitate the need for a reactor. Such embodiments are clearly not portable in the context of the needs of field applications. This paper summarises the results of a study to investigate the potential for transmission radiography based on fast neutrons. The objective of this study was to determine whether the presence of heterogeneities in concrete, such as reinforcement structures, could be identified on the basis of variation in transmitted fast-neutron flux. Monte-Carlo simulations have been performed and the results from these are compared to those arising from practical tests using a 252Cf source. The experimental data have been acquired using a digital pulse-shape discrimination system that enables fast neutron transmission to be studied across an array of liquid scintillators placed in close proximity to samples under test, and read out in real time. Whilst this study does not yield sufficient spatial resolution, a comparison of overall flux ratios does provide a basis for the discrimination between samples with contrasting rebar content. This approach offers the potential for non-destructive testing that gives less dose, better transportability and better accessibility than competing approaches. It is also suitable for thick samples where γ-ray and X-ray methods can be limited.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Roecker, C.; Bernstein, A.; Bowden, N. S.

A transportable fast neutron detection system has been designed and constructed for measuring neutron energy spectra and flux ranging from tens to hundreds of MeV. The transportability of the spectrometer reduces the detector-related systematic bias between different neutron spectra and flux measurements, which allows for the comparison of measurements above or below ground. The spectrometer will measure neutron fluxes that are of prohibitively low intensity compared to the site-specific background rates targeted by other transportable fast neutron detection systems. To measure low intensity high-energy neutron fluxes, a conventional capture-gating technique is used for measuring neutron energies above 20 MeV andmore » a novel multiplicity technique is used for measuring neutron energies above 100 MeV. The spectrometer is composed of two Gd containing plastic scintillator detectors arranged around a lead spallation target. To calibrate and characterize the position dependent response of the spectrometer, a Monte Carlo model was developed and used in conjunction with experimental data from gamma ray sources. Multiplicity event identification algorithms were developed and used with a Cf-252 neutron multiplicity source to validate the Monte Carlo model Gd concentration and secondary neutron capture efficiency. The validated Monte Carlo model was used to predict an effective area for the multiplicity and capture gating analyses. For incident neutron energies between 100 MeV and 1000 MeV with an isotropic angular distribution, the multiplicity analysis predicted an effective area of 500 cm 2 rising to 5000 cm 2. For neutron energies above 20 MeV, the capture-gating analysis predicted an effective area between 1800 cm 2 and 2500 cm 2. As a result, the multiplicity mode was found to be sensitive to the incident neutron angular distribution.« less

Evaluation of quantitative PCR for early diagnosis of Pseudomonas aeruginosa infection in cystic fibrosis: a prospective cohort study.

PubMed

Héry-Arnaud, G; Nowak, E; Caillon, J; David, V; Dirou, A; Revert, K; Munck, M-R; Frachon, I; Haloun, A; Horeau-Langlard, D; Le Bihan, J; Danner-Boucher, I; Ramel, S; Pelletier, M-P; Rosec, S; Gouriou, S; Poulhazan, E; Payan, C; Férec, C; Rault, G; Le Gal, G; Le Berre, R

2017-03-01

Early detection of Pseudomonas aeruginosa lung positivity is a key element in cystic fibrosis (CF) management. PCR has increased the accuracy of detection of many microorganisms. Clinical relevance of P. aeruginosa quantitative PCR (qPCR) in this context is unclear. Our aim was to determine P. aeruginosa qPCR sensitivity and specificity, and to assess the possible time saved by qPCR in comparison with standard practice (culture). A multicentre cohort study was conducted over a 3-year period in 96 patients with CF without chronic P. aeruginosa colonization. Sputum samples were collected at each visit. Conventional culture and two-step qPCR (oprL qPCR and gyrB/ecfX qPCR) were performed for 707 samples. The positivity criteria were based on the qPCR results, defined in a previous study as follow: oprL qPCR positivity alone if bacterial density was <730 CFU/mL or oprL qPCR combined with gyrB/ecfX qPCR if bacterial density was ≥730 CFU/mL. During follow up, 36 of the 96 patients with CF were diagnosed on culture as colonized with P. aeruginosa. This two-step qPCR displayed a sensitivity of 94.3% (95% CI 79.7%-98.6%), and a specificity of 86.3% (95% CI 83.4%-88.7%). It enabled P. aeruginosa acquisition to be diagnosed earlier in 20 patients, providing a median detection time gain of 8 months (interquartile range 3.7-17.6) for them. Implementing oprL and gyrB/ecfX qPCR in the management of patients with CF allowed earlier detection of first P. aeruginosa lung positivity than culture alone. Copyright © 2016 European Society of Clinical Microbiology and Infectious Diseases. Published by Elsevier Ltd. All rights reserved.

Tropospheric photooxidation of CF3CH2CHO and CF3(CH2)2CHO initiated by Cl atoms and OH radicals

NASA Astrophysics Data System (ADS)

Antiñolo, M.; Jiménez, E.; Notario, A.; Martínez, E.; Albaladejo, J.

2009-11-01

The absolute rate coefficients for the tropospheric reactions of chlorine (Cl) atoms and hydroxyl (OH) radicals with CF3CH2CHO and CF3(CH2)2CHO were measured as a function of temperature (263-371 K) and pressure (50-215 Torr of He) by pulsed UV laser photolysis techniques. Vacuum UV resonance fluorescence was employed to detect and monitor the time evolution of Cl atoms. Laser induced fluorescence was used in this work as a detection of OH radicals as a function of reaction time. No pressure dependence of the bimolecular rate coefficients, kCl and kOH, was found at all temperatures. At room temperature kCl and kOH were (in 10-11 cm3 molecule-1 s-1): kCl(CF3CH2CHO) = (1.55±0.53); kCl(CF3(CH2)2CHO) = (3.39±1.38); kOH(CF3CH2CHO) = (0.259±0.050); kOH(CF3(CH2)2CHO) = (1.28±0.24). A slightly negative temperature dependence of kCl was observed for CF3CH2CHO and CF3(CH2)2CHO, and kOH(CF3CH2CHO). In contrast, kOH(CF3(CH2)2CHO) did not exhibit a temperature dependence in the studied ranged. Arrhenius expressions for these reactions were: kCl(CF3CH2CHO) =(4.4±1.0) × 10-11 exp{-(316±68)/T} cm3 molecule-1 s-1, kCl(CF3(CH2)2CHO) = (2.9±0.7) × 10-10 exp{-625±80)/T} cm3 molecule-1 s-1, kOH(CF3CH2CHO) = (7.8±2.2) × 10-12 exp{-(314±90)/T} cm3 molecule-1 s-1. The atmospheric impact of the homogeneous removal by OH radicals and Cl atoms of these fluorinated aldehydes is discussed in terms of the global atmospheric lifetimes, taking into account different degradation pathways. The calculated lifetimes show that atmospheric oxidation of CF3(CH2)xCHO are globally dominated by OH radicals, however reactions initiated by Cl atoms can act as a source of free radicals at dawn in the troposphere.

Tropospheric photooxidation of CF3CH2CHO and CF3(CH2)2CHO initiated by Cl atoms and OH radicals

NASA Astrophysics Data System (ADS)

Antiñolo, M.; Jiménez, E.; Notario, A.; Martínez, E.; Albaladejo, J.

2010-02-01

The absolute rate coefficients for the tropospheric reactions of chlorine (Cl) atoms and hydroxyl (OH) radicals with CF3CH2CHO and CF3(CH2)2CHO were measured as a function of temperature (263-371 K) and pressure (50-215 Torr of He) by pulsed UV laser photolysis techniques. Vacuum UV resonance fluorescence was employed to detect and monitor the time evolution of Cl atoms. Laser induced fluorescence was used in this work for the detection of OH radicals as a function of reaction time. No pressure dependence of the bimolecular rate coefficients, kCl and kOH, was found at all temperatures. At room temperature kCl and kOH were (in 10-11 cm3 molecule-1 s-1): kCl(CF3CH2CHO) = (1.55±0.53); kCl(CF3(CH2)2CHO) = (3.39±1.38); kCl(CF3CH2CHO) = (0.259±0.050); kCl(CF3(CH2)2CHO) = (1.28±0.24). A slightly positive temperature dependence of kCl was observed for CF3CH2CHO and CF3(CH2)2CHO, and kOH(CF3CH2CHO). In contrast, kOH(CF3(CH2)2CHO) did not exhibit a temperature dependence over the range investigated. Arrhenius expressions for these reactions were: kCl(CF3CH2CHO) = (4.4±1.0)×10-11 exp{-(316±68)/T} cm3 molecule-1 s-1 kCl(CF3(CH2)2CHO) = (2.9±0.7)×10-10 exp{-(625±80)/T} cm3 molecule-1 s-1 kOH(CF3CH2CHO) = (7.8±2.2)×10-12 exp{-(314±90)/T} cm3 molecule-1 s-1 The atmospheric impact of the homogeneous removal by OH radicals and Cl atoms of these fluorinated aldehydes is discussed in terms of the global atmospheric lifetimes, taking into account different degradation pathways. The calculated lifetimes show that atmospheric oxidation of CF3(CH2)x CHO are globally dominated by OH radicals, however reactions initiated by Cl atoms can act as a source of free radicals at dawn in the troposphere.

Anemia after continuous-flow left ventricular assist device implantation: characteristics and implications.

PubMed

Amione-Guerra, Javier; Cruz-Solbes, Ana S; Bhimaraj, Arvind; Trachtenberg, Barry H; Pingali, Sai R; Estep, Jerry D; Park, Myung H; Guha, Ashrith

2017-09-15

Anemia is common in patients with heart failure and is associated with adverse outcomes. Management of anemia in CF-LVAD patients is not well studied. Our purpose is to characterize and identify the etiology of anemia in CF-LVAD patients. Secondary objectives are to describe the effect of CF-LVAD on pre-existing anemia and assess its impact after CF-LVAD support. Cross-sectional study from January to July 2015 of ambulatory patients supported with a CF-LVAD for at least 6-months that presented with hemoglobin <12 g/dL and no recent gastrointestinal bleeding. Patients were classified as iron-deficient and non-iron-deficient and compared. Additionally, a retrospective analysis of 116 consecutive patients who underwent CF-LVAD from 2008 to 2013 with reported hemoglobin at 6 months as outpatients were divided into anemic or non-anemic and compared. In our cross-sectional cohort, iron deficiency was the most common cause of anemia. Notably, 49% of the iron-deficient patients were already on iron supplementation. In our retrospective cohort, 59% of the patients were anemic after 6 months of support. Anemic patients were older, had lower albumin, higher brain natriuretic peptide (BNP), worse renal function and New York Heart Association (NYHA) class. Anemia had a HR of 3.16 (95%CI 1.38-7.26) to predict a composite of 1-year death and HF readmissions, as well as HF-readmissions alone. The most common cause of anemia in our study was iron-deficiency; almost half of the patients were iron deficient despite treatment, suggesting that oral iron may not be sufficient to reverse anemia. Anemia regardless of etiology was associated with adverse outcomes.

Water quality and health in northern Canada: stored drinking water and acute gastrointestinal illness in Labrador Inuit.

PubMed

Wright, Carlee J; Sargeant, Jan M; Edge, Victoria L; Ford, James D; Farahbakhsh, Khosrow; Shiwak, Inez; Flowers, Charlie; Harper, Sherilee L

2017-07-12

One of the highest self-reported incidence rates of acute gastrointestinal illness (AGI) in the global peer-reviewed literature occurs in Inuit communities in the Canadian Arctic. This high incidence of illness could be due, in part, to the consumption of contaminated water, as many northern communities face challenges related to the quality of municipal drinking water. Furthermore, many Inuit store drinking water in containers in the home, which could increase the risk of contamination between source and point-of-use (i.e., water recontamination during storage). To examine this risk, this research characterized drinking water collection and storage practices, identified potential risk factors for water contamination between source and point-of-use, and examined possible associations between drinking water contamination and self-reported AGI in the Inuit community of Rigolet, Canada. The study included a cross-sectional census survey that captured data on types of drinking water used, household practices related to drinking water (e.g., how it was collected and stored), physical characteristics of water storage containers, and self-reported AGI. Additionally, water samples were collected from all identified drinking water containers in homes and analyzed for presence of Escherichia coli and total coliforms. Despite municipally treated tap water being available in all homes, 77.6% of households had alternative sources of drinking water stored in containers, and of these containers, 25.2% tested positive for total coliforms. The use of transfer devices and water dippers (i.e., smaller bowls or measuring cups) for the collection and retrieval of water from containers were both significantly associated with increased odds of total coliform presence in stored water (OR transfer device  = 3.4, 95% CI 1.2-11.7; OR dipper  = 13.4, 95% CI 3.8-47.1). Twenty-eight-day period prevalence of self-reported AGI during the month before the survey was 17.2% (95% CI 13.0-22.5), which yielded an annual incidence rate of 2.4 cases per person per year (95% CI 1.8-3.1); no water-related risk factors were significantly associated with AGI. Considering the high prevalence of, and risk factors associated with, indicator bacteria in drinking water stored in containers, potential exposure to waterborne pathogens may be minimized through interventions at the household level.

Gladstone-Dale constant for CF4. [experimental design

NASA Technical Reports Server (NTRS)

Burner, A. W., Jr.; Goad, W. K.

1980-01-01

The Gladstone-Dale constant, which relates the refractive index to density, was measured for CF4 by counting fringes of a two-beam interferometer, one beam of which passes through a cell containing the test gas. The experimental approach and sources of systematic and imprecision errors are discussed. The constant for CF4 was measured at several wavelengths in the visible region of the spectrum. A value of 0.122 cu cm/g with an uncertainty of plus or minus 0.001 cu cm/g was determined for use in the visible region. A procedure for noting the departure of the gas density from the ideal-gas law is discussed.

Glucose-6-phosphate dehydrogenase deficient variants are associated with reduced susceptibility to malaria in the Brazilian Amazon.

PubMed

Santana, Marli S; Monteiro, Wuelton M; Siqueira, André M; Costa, Mônica F; Sampaio, Vanderson; Lacerda, Marcus V; Alecrim, Maria G

2013-05-01

Glucose-6-phosphate dehydrogenase deficiency (G6PDd) has been shown to protect against malaria infection and severe manifestations in African and Asia, but there is a scarcity of studies in the Americas. This study aimed to study the prevalence of G6PDd and its association with malaria occurrence in the Brazilian Amazon. A cross-sectional study was conducted in the male population to estimate the prevalence of G6PDd and malaria infection. G6PD deficient samples were genotyped to identify the deficient variant. Number of previous malaria episodes and need for blood transfusion during malaria episodes were recorded by applying a standardized questionary. From a sample of 1478 male individuals, 66 were detected as G6PD deficient, resulting in a prevalence of of 4.5% (95% CI = 3.44-5.56%). Fifty six G6PD deficient individuals (3.8%; 95% CI = 2.82-4.77) presented the G6PD A-variant mutation, while 10 individuals (0.7%; 95% CI = 0.42-0.97) severely deficient were genotyped as carriers of the G6PD Mediterranean variant. After adjusting for age, G6PD deficient individuals were less likely to report the occurrence of malaria episodes, and the protective effect was related to the enzyme activity, with carriers of the GG6PD A-variant presenting a 88% reduction (AOR: 0.119; 95% CI = 0.057-0.252; p < 0.001) and carriers of the Meditarrenean variant presenting 99% lower risk (AOR: 0.010; 95% CI = 0.002-0.252; p < 0.001) when compared to non-deficient individuals. On the other hand, G6PD deficient subjects reported higher need of transfusion during malaria episodes (p < 0.001). G6PD enzyme activity was directly related to susceptibility to malaria in the Brazilian Amazon, where P. vivax predominates. Severe G6PDd was associated with considerable higher risk of malaria-related transfusions.

Skepticism Regarding Vaccine and Gluten-Free Food Safety Among Patients with Celiac Disease and Non-celiac Gluten Sensitivity.

PubMed

Rabinowitz, Loren G; Zylberberg, Haley M; Levinovitz, Alan; Stockwell, Melissa S; Green, Peter H R; Lebwohl, Benjamin

2018-05-01

There has been a marked increase in the adoption of the gluten-free (GF) diet. To query individuals with celiac disease (CD) and non-celiac gluten sensitivity (NCGS) on their beliefs toward the health effects of gluten, and safety of vaccines and GF food products. We distributed a Web-based survey to individuals with CD and NCGS on a CD center e-mail list. We used univariate and multivariate analysis to compare responses of respondents with CD and NCGS. The overall response rate was 27% (NCGS n = 217, CD n = 1291). Subjects with NCGS were more likely than those with CD to disagree with the statement that "vaccines are safe for people with celiac disease" (NCGS 41.3% vs. CD 26.4% (p < 0.0001), and were more likely to decline vaccination when offered (30.9 vs. 24.2%, p = 0.007). After adjusting for age and gender, NCGS subjects were more likely than CD subjects to avoid genetically modified (GMO) foods (aOR 2.30; 95% CI 1.71-3.10), eat only organic products (aOR 2.87; 95% CI 2.04-4.03), believe that the FDA is an unreliable source of information (aOR 1.82, 95% CI 1.26-2.64), and believe a GF diet improves energy and concentration (aOR 2.52; 95% CI 1.86-3.43). Subjects with NCGS were more likely than those with CD to have doubts about vaccine safety and believe in the value of non-GMO and organic foods. Our findings suggest that the lack of reliable information on gluten and its content in food and medications may reinforce beliefs that result in a detriment to public health.

Pulmonary function disparities exist and persist in Hispanic patients with cystic fibrosis: A longitudinal analysis.

PubMed

McGarry, Meghan E; Neuhaus, John M; Nielson, Dennis W; Burchard, Esteban; Ly, Ngoc P

2017-12-01

Hispanic patients with cystic fibrosis (CF) have decreased life expectancy compared to non-Hispanic white patients. Pulmonary function is a main predictor of life expectancy in CF. Ethnic differences in pulmonary function in CF have been understudied. The objective was to compare longitudinal pulmonary function between Hispanic and non-Hispanic white patients with CF. This cohort study of 15 018 6-25 years old patients in the CF Foundation Patient Registry from 2008 to 2013 compared FEV 1 percent predicted and longitudinal change in FEV 1 percent predicted in Hispanic to non-Hispanic white patients. We used linear mixed effects models with patient-specific slopes and intercepts, adjusting for 14 demographic and clinical variables. We did sub-analyses by CFTR class, F508del copies, and PERT use. Hispanic patients had lower FEV 1 percent predicted (79.9%) compared with non-Hispanic white patients (85.6%); (-5.8%, 95%CI -6.7% to -4.8%, P < 0.001), however, there was no difference in FEV 1 decline over time. Patients on PERT had a larger difference between Hispanic and non-Hispanic white patients in FEV 1 percent predicted than patients not on PERT (-6.0% vs -4.1%, P = 0.02). The ethnic difference in FEV 1 percent predicted was not statistically significant between CFTR classes (Class I-III: -6.1%, Class IV-V: -5.9%, Unclassified: -5.7%, P > 0.05) or between F508del copies (None: -7.6%, Heterozygotes: -5.6%, Homozygotes: -5.3%, P > 0.05). Disparities in pulmonary function exist in Hispanic patients with CF early in life and then persist without improving or worsening over time. It is valuable to investigate the factors contributing to pulmonary function in Hispanic patients with CF. © 2017 Wiley Periodicals, Inc.

48 CFR 252.227-7013 - Rights in technical data-Noncommercial items.

Code of Federal Regulations, 2011 CFR

2011-10-01

... causing a computer to perform a specific operation or series of operations. (3) Computer software means computer programs, source code, source code listings, object code listings, design details, algorithms... or will be developed exclusively with Government funds; (ii) Studies, analyses, test data, or similar...

48 CFR 252.227-7013 - Rights in technical data-Noncommercial items.

Code of Federal Regulations, 2012 CFR

2012-10-01

... causing a computer to perform a specific operation or series of operations. (3) Computer software means computer programs, source code, source code listings, object code listings, design details, algorithms... or will be developed exclusively with Government funds; (ii) Studies, analyses, test data, or similar...

48 CFR 252.227-7013 - Rights in technical data-Noncommercial items.

Code of Federal Regulations, 2014 CFR

2014-10-01

... causing a computer to perform a specific operation or series of operations. (3) Computer software means computer programs, source code, source code listings, object code listings, design details, algorithms... or will be developed exclusively with Government funds; (ii) Studies, analyses, test data, or similar...

48 CFR 252.227-7013 - Rights in technical data-Noncommercial items.

Code of Federal Regulations, 2010 CFR

2010-10-01

... causing a computer to perform a specific operation or series of operations. (3) Computer software means computer programs, source code, source code listings, object code listings, design details, algorithms... developed exclusively with Government funds; (ii) Studies, analyses, test data, or similar data produced for...

Candida albicans chronic colonisation in cystic fibrosis may be associated with inhaled antibiotics.

PubMed

Noni, Maria; Katelari, Anna; Kaditis, Athanasios; Theochari, Ioanna; Lympari, Ioulia; Alexandrou-Athanassoulis, Helen; Doudounakis, Stavros-Eleftherios; Dimopoulos, George

2015-07-01

Candida albicans is increasingly recognised as a coloniser of the respiratory tract in cystic fibrosis (CF) patients. Yet, the potential role, if any, of the micro-organism in the progress of the disease remains unclear. In this study, we investigated the association between inhaled antibiotics and C. albicans chronic colonisation in patients with CF. A cohort of 121 CF patients born from 1988 to 1996 was, respectively, studied. The medical records of each patient were reviewed from the first time they attended the CF Centre until the occurrence of C. albicans chronic colonisation or their last visit for the year 2010. Chronic colonisation was defined as the presence of C. albicans in more than 50% of cultures in a given year. A number of possible confounders were included in the multivariate logistic regression analysis to identify an independent association between inhaled antibiotics and C. albicans chronic colonisation. Fifty-four (44.6%) of the 121 patients enrolled in the study developed chronic colonisation by the micro-organism. Multivariate logistic regression analysis determined the independent effect of inhaled antibiotic treatment on the odds of chronic colonisation (OR 1.112, 95% CI [1.007-1.229], P = 0.036). Candida albicans chronic colonisation may be associated with the duration of inhaled antibiotic treatment. © 2015 Blackwell Verlag GmbH.

Atmospheric observations and inverse modelling for quantifying emissions of point-source synthetic greenhouse gases in East Asia

NASA Astrophysics Data System (ADS)

Arnold, Tim; Manning, Alistair; Li, Shanlan; Kim, Jooil; Park, Sunyoung; Muhle, Jens; Weiss, Ray

2017-04-01

The fluorinated species carbon tetrafluoride (CF4; PFC-14), nitrogen trifluoride (NF3) and trifluoromethane (CHF3; HFC-23) are potent greenhouse gases with 100-year global warming potentials of 6,630, 16,100 and 12,400, respectively. Unlike the majority of CFC-replacements that are emitted from fugitive and mobile emission sources, these gases are mostly emitted from large single point sources - semiconductor manufacturing facilities (all three), aluminium smelting plants (CF4) and chlorodifluoromethane (HCFC-22) factories (HFC-23). In this work we show that atmospheric measurements can serve as a basis to calculate emissions of these gases and to highlight emission 'hotspots'. We use measurements from one Advanced Global Atmospheric Gases Experiment (AGAGE) long term monitoring sites at Gosan on Jeju Island in the Republic of Korea. This site measures CF4, NF3 and HFC-23 alongside a suite of greenhouse and stratospheric ozone depleting gases every two hours using automated in situ gas-chromatography mass-spectrometry instrumentation. We couple each measurement to an analysis of air history using the regional atmospheric transport model NAME (Numerical Atmospheric dispersion Modelling Environment) driven by 3D meteorology from the Met Office's Unified Model, and use a Bayesian inverse method (InTEM - Inversion Technique for Emission Modelling) to calculate yearly emission changes over seven years between 2008 and 2015. We show that our 'top-down' emission estimates for NF3 and CF4 are significantly larger than 'bottom-up' estimates in the EDGAR emissions inventory (edgar.jrc.ec.europa.eu). For example we calculate South Korean emissions of CF4 in 2010 to be 0.29±0.04 Gg/yr, which is significantly larger than the Edgar prior emissions of 0.07 Gg/yr. Further, inversions for several separate years indicate that emission hotspots can be found without prior spatial information. At present these gases make a small contribution to global radiative forcing, however, given that the impact of these long-lived gases could rise significantly and that point sources of such gases can be mitigated, atmospheric monitoring could be an important tool for aiding emissions reduction policy.

A Targeted Q-PCR-Based Method for Point Mutation Testing by Analyzing Circulating DNA for Cancer Management Care.

PubMed

Thierry, Alain R

2016-01-01

Circulating cell-free DNA (cfDNA) is a valuable source of tumor material available with a simple blood sampling enabling a noninvasive quantitative and qualitative analysis of the tumor genome. cfDNA is released by tumor cells and exhibits the genetic and epigenetic alterations of the tumor of origin. Circulating cell-free DNA (cfDNA) analysis constitutes a hopeful approach to provide a noninvasive tumor molecular test for cancer patients. Based upon basic research on the origin and structure of cfDNA, new information on circulating cell-free DNA (cfDNA) structure, and specific determination of cfDNA fragmentation and size, we revisited Q-PCR-based method and recently developed a the allele-specific-Q-PCR-based method with blocker (termed as Intplex) which is the first multiplexed test for cfDNA. This technique, named Intplex(®) and based on a refined Q-PCR method, derived from critical observations made on the specific structure and size of cfDNA. It enables the simultaneous determination of five parameters: the cfDNA total concentration, the presence of a previously known point mutation, the mutant (tumor) cfDNA concentration (ctDNA), the proportion of mutant cfDNA, and the cfDNA fragmentation index. Intplex(®) has enabled the first clinical validation of ctDNA analysis in oncology by detecting KRAS and BRAF point mutations in mCRC patients and has demonstrated that a blood test could replace tumor section analysis for the detection of KRAS and BRAF mutations. The Intplex(®) test can be adapted to all mutations, genes, or cancers and enables rapid, highly sensitive, cost-effective, and repetitive analysis. As regards to the determination of mutations on cfDNA Intplex(®) is limited to the mutational status of known hotspot mutation; it is a "targeted approach." However, it offers the opportunity in detecting quantitatively and dynamically mutation and could constitute a noninvasive attractive tool potentially allowing diagnosis, prognosis, theranostics, therapeutic monitoring, and follow-up of cancer patients expanding the scope of personalized cancer medicine.

Environmental lead and childhood blood lead levels in US children: NHANES, 1999-2006.

PubMed

Benson, Stacey M; Talbott, Evelyn O; Brink, LuAnn L; Wu, Candace; Sharma, Ravi K; Marsh, Gary M

2017-03-04

Although blood lead levels in the United States have fallen dramatically since 1980, there remain subgroups of children with high blood lead levels. We assessed the relationship between environmental lead sources and blood lead levels in children ages 1 to 5 years from the National Health and Nutrition Examination Survey (NHANES), 1999-2006. Modeled ambient air lead levels and industrial lead releases at the census-tract level were assigned to each child's residence with adjustment for confounding factors. Of 3,223 children, 272 (8.4%) had blood lead levels ≥ 5 ug/dL. Industrial releases (2,252 vs 1,696 lbs/mi 2 ) and ambient air lead levels (2.28 vs 1.75 ng/m 3 ) were greater in exposed versus unexposed children. For every 10,000 lb/mi 2 increase in inverse distance squared weighted exposure, there was a 1.13% increase (95% CI: 0.45%, 1.81%) in blood lead (p = .001).

U.S. EPA, Pesticide Product Label, RL 2 DUST CONTAINS CO-RAL, 03/02/1987

EPA Pesticide Factsheets

2011-04-21

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40 CFR 60.252 - Standards for thermal dryers.

Code of Federal Regulations, 2010 CFR

2010-07-01

...) heat input. (iii) Thermal dryers that receive all of their thermal input from a source other than coal... (CONTINUED) STANDARDS OF PERFORMANCE FOR NEW STATIONARY SOURCES Standards of Performance for Coal Preparation.../MMBtu) heat input; or (ii) The owner or operator must not cause to be discharged into the atmosphere...

48 CFR 252.227-7013 - Rights in technical data-Noncommercial items.

Code of Federal Regulations, 2013 CFR

2013-10-01

... causing a computer to perform a specific operation or series of operations. (3) Computer software means computer programs, source code, source code listings, object code listings, design details, algorithms... funds; (ii) Studies, analyses, test data, or similar data produced for this contract, when the study...

Patterns of IgE responses to multiple allergen components and clinical symptoms at age 11 years

PubMed Central

Simpson, Angela; Lazic, Nevena; Belgrave, Danielle C.M.; Johnson, Phil; Bishop, Christopher; Mills, Clare; Custovic, Adnan

2015-01-01

Background The relationship between sensitization to allergens and disease is complex. Objective We sought to identify patterns of response to a broad range of allergen components and investigate associations with asthma, eczema, and hay fever. Methods Serum specific IgE levels to 112 allergen components were measured by using a multiplex array (Immuno Solid-phase Allergen Chip) in a population-based birth cohort. Latent variable modeling was used to identify underlying patterns of component-specific IgE responses; these patterns were then related to asthma, eczema, and hay fever. Results Two hundred twenty-one of 461 children had IgE to 1 or more components. Seventy-one of the 112 components were recognized by 3 or more children. By using latent variable modeling, 61 allergen components clustered into 3 component groups (CG1, CG2, and CG3); protein families within each CG were exclusive to that group. CG1 comprised 27 components from 8 plant protein families. CG2 comprised 7 components of mite allergens from 3 protein families. CG3 included 27 components of plant, animal, and fungal origin from 12 protein families. Each CG included components from different biological sources with structural homology and also nonhomologous proteins arising from the same biological source. Sensitization to CG3 was most strongly associated with asthma (odds ratio [OR], 8.20; 95% CI, 3.49-19.24; P < .001) and lower FEV1 (P < .001). Sensitization to CG1 was associated with hay fever (OR, 12.79; 95% CI, 6.84-23.90; P < .001). Sensitization to CG2 was associated with both asthma (OR, 3.60; 95% CI, 2.05-6.29) and hay fever (OR, 2.52; 95% CI, 1.38-4.61). Conclusions Latent variable modeling with a large number of allergen components identified 3 patterns of IgE responses, each including different protein families. In 11-year-old children the pattern of response to components of multiple allergens appeared to be associated with current asthma and hay fever but not eczema. PMID:25935108

A facile approach towards increasing the nitrogen-content in nitrogen-doped carbon nanotubes via halogenated catalysts

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ombaka, L.M.; Ndungu, P.G.; Department of Applied Chemistry, Doornfontein Campus, University of Johannesburg, P.O. Box 17011, Johannesburg 2028

Nitrogen-doped carbon nanotubes (N-CNTs) have been synthesized at 850 °C via a CVD deposition technique by use of three ferrocenyl derivative catalysts, i.e. para-CN, -CF{sub 3} and -Cl substituted-phenyl rings. The synthesized catalysts have been characterized by NMR, IR, HR-MS and XRD. The XRD analysis of the para-CF{sub 3} catalyst indicates that steric factors influence the X-ray structure of 1,1′-ferrocenylphenyldiacrylonitriles. Acetonitrile or pyridine was used as carbon and nitrogen sources to yield mixtures of N-CNTs and carbon spheres (CS). The N-CNTs obtained from the para-CF{sub 3} catalysts, in pyridine, have the highest nitrogen-doping level, show a helical morphology and aremore » less thermally stable compared with those synthesized by use of the para-CN and -Cl as catalyst. This suggests that fluorine heteroatoms enhance nitrogen-doping in N-CNTs and formation of helical-N-CNTs (H-N-CNTs). The para-CF{sub 3} and para-Cl catalysts in acetonitrile yielded iron-filled N-CNTs, indicating that halogens promote encapsulation of iron into the cavity of N-CNT. The use of acetonitrile, as carbon and nitrogen source, with the para-CN and -Cl as catalysts also yielded a mixture of N-CNTs and carbon nanofibres (CNFs), with less abundance of CNFs in the products obtained using para-Cl catalysts. However, para-CF{sub 3} catalyst in acetonitrile gave N-CNTs as the only shaped carbon nanomaterials. - Graphical abstract: Graphical abstract showing the synthesis of N-CNTs using halogenated-ferrocenyl derivatives as catalyst with pyridine or acetonitrile as nitrogen and carbon sources via the chemical vapour deposition technique. - Highlights: • N-CNTs were synthesized from halogenated ferrocenyl catalysts. • Halogenated catalysts promote nitrogen-doping and pyridinic nitrogen in N-CNTs. • Halogenated catalysts facilitate iron filling of N-CNTs.« less

Clinical chronic rhinosinusitis outcomes in pediatric patients with cystic fibrosis

PubMed Central

2017-01-01

Objectives Chronic rhinosinusitis and nasal polyposis are common conditions in cystic fibrosis (CF). Approximately 2–3% of pediatric CF patients per year have sinus disease requiring surgery. It has been well established that there is a significant negative impact on quality of life associated with chronic rhinosinusitis (CRS) in the non‐CF patient population. However, the impact of CRS on the pediatric CF population remains uncertain. The purpose of this article is to review the current state of outcome measures for CRS in pediatric CF patients. Data Sources PubMed and EMBASE literature review Methods PubMed and EMBASE electronic databases were searched using Boolean searches that incorporated mesh headings and plain language for quality of life, symptom evaluation, pediatric patients, and sinusitis/rhinosinusitis. Studies were included if the study primarily evaluated a pediatric Cystic Fibrosis‐Chronic Rhinosinusitis (CF‐CRS) population and the primary outcome measure was quality of life evaluation. Results The search yielded 34 unique articles. A total of 7 articles met inclusion criteria Conclusions Despite the high frequency of chronic rhinosinusitis in the pediatric CF patient population, its impact on quality of life is not well understood. Currently there is a lack of a validated disease specific quality of life instruments available to assess the impact of CRS on the pediatric CF patient population. Level of Evidence 5. PMID:29094071

A cAMP-Regulated Chloride Channel in Lymphocytes that is Affected in Cystic Fibrosis

NASA Astrophysics Data System (ADS)

Chen, Jennifer H.; Schulman, Howard; Gardner, Phyllis

1989-02-01

A defect in regulation of a chloride channel appears to be the molecular basis for cystic fibrosis (CF), a common lethal genetic disease. It is shown here that a chloride channel with kinetic and regulatory properties similar to those described for secretory epithelial cells is present in both T and B lymphocyte cell lines. The regulation of the channels by adenosine 3',5'-monophosphate (cAMP)--dependent protein kinase in transformed B cells from CF patients is defective. Thus, lymphocytes may be an accessible source of CF tissue for study of this defect, for cloning of the chloride channel complex, and for diagnosis of the disease.

Parity-Doublet Structure in the $$147\\atop{57}$$La 90 nucleus

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wisniewski, J.; Urban, W.; Rzaca-Urban, T.

Excited states in 147La, populated in spontaneous fission of 252Cf have been reinvestigated by means of γ spectroscopy, using high-fold γ coincidences measured with Gammasphere array of Ge detectors. The 229.5-keV level, which has been assigned spin-parity 9/2 - in a recent evaluation, is shown to have spin-parity 11/2 -. Consequently, the ground state has spin-parity 5/2 +. Excited levels in 147La have been arranged into a parity-doublet structure, showing that at medium excitation energy the 147La nucleus may have octupole deformation. In conclusion, the B( E1) rates in 147La, which are factor four lower than in 145La, suggest thatmore » the electric dipole moment in 147La is depresses by an extra mechanism, probably connected with the population of particular neutron orbitals.« less

Cs2LiLa(Br,Cl)6 Crystals for Nuclear Security Applications

NASA Astrophysics Data System (ADS)

Hawrami, R.; Pandian, L. Soundara; Ariesanti, E.; Glodo, J.; Finkelstein, J.; Tower, J.; Shah, K.

2016-04-01

Properties of dual-mode scintillation detectors based on CLLBC crystals are reported. Energy resolution and light yield are measured at 2.9% (FWHM) at 662 keV and 45000 photons/MeV, respectively, for a 1-in-diameter and 1-in-long crystal. With less than 2% variation in light yield as a function of energy, CLLBC has better proportionality than LaBr3 and NaI:Tl. Neutron peak resulting from reactions with neutrons emitted by 252Cf (moderated) is measured at a gamma energy equivalent of 3.1 MeVee (electron energy equivalent), making pulse height discrimination between gamma-rays and neutrons easy. The material is also of effective pulse shape discrimination. The figure-of-merit for discrimination of gamma rays and thermal neutrons in CLLBC can be as high as 3.2, which is comparable to that of CLYC.

Neutron-induced fission: properties of prompt neutron and γ rays as a function of incident energy

NASA Astrophysics Data System (ADS)

Stetcu, I.; Talou, P.; Kawano, T.

2016-06-01

We have applied the Hauser-Feshbach statistical theory, in a Monte-Carlo implementation, to the de-excitation of fission fragments, obtaining a reasonable description of the characteristics of neutrons and gamma rays emitted before beta decays toward stability. Originally implemented for the spontaneous fission of 252Cf and the neutroninduced fission of 235U and 239Pu at thermal neutron energy, in this contribution we discuss the extension of the formalism to incident neutron energies up to 20 MeV. For the emission of pre-fission neutrons, at incident energies beyond second-chance fission, we take into account both the pre-equilibrium and statistical pre-fission components. Phenomenological parameterizations of mass, charge and TKE yields are used to obtain the initial conditions for the fission fragments that subsequently decay via neutron and emissions. We illustrate this approach for 239Pu(n,f).

Parity-Doublet Structure in the $$147\\atop{57}$$La 90 nucleus

DOE PAGES

Wisniewski, J.; Urban, W.; Rzaca-Urban, T.; ...

2017-12-01

Excited states in 147La, populated in spontaneous fission of 252Cf have been reinvestigated by means of γ spectroscopy, using high-fold γ coincidences measured with Gammasphere array of Ge detectors. The 229.5-keV level, which has been assigned spin-parity 9/2 - in a recent evaluation, is shown to have spin-parity 11/2 -. Consequently, the ground state has spin-parity 5/2 +. Excited levels in 147La have been arranged into a parity-doublet structure, showing that at medium excitation energy the 147La nucleus may have octupole deformation. In conclusion, the B( E1) rates in 147La, which are factor four lower than in 145La, suggest thatmore » the electric dipole moment in 147La is depresses by an extra mechanism, probably connected with the population of particular neutron orbitals.« less