Solid Xenon Project

NASA Astrophysics Data System (ADS)

Balakishiyeva, Durdana N.; Mahapatra, Rupak; Saab, Tarek; Yoo, Jonghee

2010-08-01

Crystals like Germanium and Silicon need to be grown in specialized facilities which is time and money costly. It takes many runs to test the detector once it's manufactured and mishaps are very probable. It is of a great challenge to grow big germanium crystals and that's why stacking them up in a tower is the only way at the moment to increase testing mass. Liquid Noble gas experiments experiencing contamination problems, their predicted energy resolution at 10 keV and lower energy range is not as good as predicted. Every experiment is targeting one specific purpose, looking for one thing. Why not to design an experiment that is diverse and build a detector that can search for Dark Matter, Solar Axions, Neutrinoless Double Beta decay, etc. Solid Xenon detector is such detector. We designed a simple Xenon crystal growing chamber that was put together at Fermi National Accelerator Laboratory. The first phase of this experiment was to demonstrate that a good, crack free Xenon crystal can be grown (regardless of many failed attempts by various groups) and our first goal, 1 kg crystal, was successful.

Hyperpolarized xenon NMR and MRI signal amplification by gas extraction

PubMed Central

Zhou, Xin; Graziani, Dominic; Pines, Alexander

2009-01-01

A method is reported for enhancing the sensitivity of NMR of dissolved xenon by detecting the signal after extraction to the gas phase. We demonstrate hyperpolarized xenon signal amplification by gas extraction (Hyper-SAGE) in both NMR spectra and magnetic resonance images with time-of-flight information. Hyper-SAGE takes advantage of a change in physical phase to increase the density of polarized gas in the detection coil. At equilibrium, the concentration of gas-phase xenon is ≈10 times higher than that of the dissolved-phase gas. After extraction the xenon density can be further increased by several orders of magnitude by compression and/or liquefaction. Additionally, being a remote detection technique, the Hyper-SAGE effect is further enhanced in situations where the sample of interest would occupy only a small proportion of the traditional NMR receiver. Coupled with targeted xenon biosensors, Hyper-SAGE offers another path to highly sensitive molecular imaging of specific cell markers by detection of exhaled xenon gas. PMID:19805177

Is xenon eldest?

NASA Technical Reports Server (NTRS)

Zahnle, K.

1994-01-01

It is well known that the solubility of noble gases in magmas decreases with increasing atomic weight. Xenon, the weightiest of the stable noble gases, is the least soluble atmospheric gas in magma. It is not unreasonable to suppose that the noble gases should have degassed from (or equilibrated with) a bubbling mantle in order of increasing solubility, such that xenon was the most rapidly degassed and helium the least. The apparent relative ages of the famous radiogenic noble gas isotopes agrees, at least qualitatively, with this premise. When atmospheric loss processes are assigned their proper place, several long-standing xenonological puzzles become added evidence for xenon's relative antiquity. Xenon being the afore-mentioned sense the oldest atmospheric gas, will have been most greatly subject to escape, be it impact-driven or EUV-driven. Nonradiogenic xenon's pronounced isotopic fractionation has already been attributed to escape; why it should be more fractionated than krypton would be assigned to xenon's greater atmospheric age. The small atmospheric inventory of xenon relative to the other nonradiogenic noblegases, known as the 'missing xenon' problem, could easily be explained by differential escape. The relatively tiny atmospheric inventories of the radiogenic daughter products of 129 Iodine and 244 Plutonium, both much smaller than would be expected from the inferred abundances of the parents in meteorites, offer a third and fourth data to support the hypothesis that Earth has lost most of its xenon.

Xenon Sputter Yield Measurements for Ion Thruster Materials

NASA Technical Reports Server (NTRS)

Williams, John D.; Gardner, Michael M.; Johnson, Mark L.; Wilbur, Paul J.

2003-01-01

In this paper, we describe a technique that was used to measure total and differential sputter yields of materials important to high specific impulse ion thrusters. The heart of the technique is a quartz crystal monitor that is swept at constant radial distance from a small target region where a high current density xenon ion beam is aimed. Differential sputtering yields were generally measured over a full 180 deg arc in a plane that included the beam centerline and the normal vector to the target surface. Sputter yield results are presented for a xenon ion energy range from 0.5 to 10 keV and an angle of incidence range from 0 deg to 70 deg from the target surface normal direction for targets consisting of molybdenum, titanium, solid (Poco) graphite, and flexible graphite (grafoil). Total sputter yields are calculated using a simple integration procedure and comparisons are made to sputter yields obtained from the literature. In general, the agreement between the available data is good. As expected for heavy xenon ions, the differential and total sputter yields are found to be strong functions of angle of incidence. Significant under- and over-cosine behavior is observed at low- and high-ion energies, respectively. In addition, strong differences in differential yield behavior are observed between low-Z targets (C and Ti) and high-Z targets (Mo). Curve fits to the differential sputter yield data are provided. They should prove useful to analysts interested in predicting the erosion profiles of ion thruster components and determining where the erosion products re-deposit.

Xenon inhibits excitatory but not inhibitory transmission in rat spinal cord dorsal horn neurons

PubMed Central

2010-01-01

Background The molecular targets for the promising gaseous anaesthetic xenon are still under investigation. Most studies identify N-methyl-D-aspartate (NMDA) receptors as the primary molecular target for xenon, but the role of α-amino-3-hydroxy-5-methyl-4-isoxazole-4-propionic acid (AMPA) receptors is less clear. In this study we evaluated the effect of xenon on excitatory and inhibitory synaptic transmission in the superficial dorsal horn of the spinal cord using in vitro patch-clamp recordings from rat spinal cord slices. We further evaluated the effects of xenon on innocuous and noxious stimuli using in vivo patch-clamp method. Results In vitro, xenon decreased the amplitude and area under the curve of currents induced by exogenous NMDA and AMPA and inhibited dorsal root stimulation-evoked excitatory postsynaptic currents. Xenon decreased the amplitude, but not the frequency, of miniature excitatory postsynaptic currents. There was no discernible effect on miniature or evoked inhibitory postsynaptic currents or on the current induced by inhibitory neurotransmitters. In vivo, xenon inhibited responses to tactile and painful stimuli even in the presence of NMDA receptor antagonist. Conclusions Xenon inhibits glutamatergic excitatory transmission in the superficial dorsal horn via a postsynaptic mechanism. There is no substantial effect on inhibitory synaptic transmission at the concentration we used. The blunting of excitation in the dorsal horn lamina II neurons could underlie the analgesic effect of xenon. PMID:20444263

Xenon Feed System Progress

DTIC Science & Technology

2006-01-01

From - To) 13-06-2006 Technical Paper 4. TITLE AND SUBTITLE 5a. CONTRACT NUMBER F04611-00-C-0055 Xenon Feed System Progress (Preprint) 5b. GRANT...propulsion xenon feed system for a flight technology demonstration program. Major accomplishments include: 1) Utilization of the Moog...successfully fed xenon to a 200 watt Hall Effect Thruster in a Technology Demonstration Program. The feed system has demonstrated throttling of xenon

Xenon Anesthesia: A Systematic Review and Meta-Analysis of Randomized Controlled Trials.

PubMed

Law, Lawrence Siu-Chun; Lo, Elaine Ah-Gi; Gan, Tong Joo

2016-03-01

Xenon anesthesia has been studied for decades. However, no meta-analysis of randomized controlled trials (RCTs) on xenon anesthesia has been conducted. The aim of this study was to systematically review all available evidence from RCTs comparing xenon and other inhaled and IV anesthetics on anesthetic outcomes. Our meta-analysis attempted to quantify the effects of xenon anesthesia on clinical outcomes in relation to other anesthetics. We found 43 RCTs from PubMed, MEDLINE, CENTRAL, EMBASE, and CINAHL (until January 2015). A total of 31 studies comparing xenon (841 patients) with other inhaled agents (836 patients) and 12 studies comparing xenon (373 patients) with propofol (360 patients) were found. We evaluated clinical outcomes, such as intraoperative hemodynamics, emergence, and postoperative nausea and vomiting (PONV). Patients undergoing xenon anesthesia had a lower heart rate and higher mean arterial pressure (MAP) intraoperatively than those receiving volatile anesthesia (mean difference = -6 min⁻¹ [99% confidence interval {99% CI} -10.0 to -2.3]; mean difference = 9 mm Hg [99% CI 3.1-14.4]) and propofol anesthesia (mean difference = -10 min⁻¹ [99% CI -12.4 to -6.6]; mean difference = 7 mm Hg [99% CI 0.85-13.2]). Compared with baseline, intraoperative MAP remained relatively stable (change < 5.5%, 99% CI within ±20% of the baseline) under xenon anesthesia, but MAP decreased by ≥15% under volatile (mean difference = -17 mm Hg [99% CI -29.5 to - 4.9], percentage change = -17.5%) and propofol (mean difference = -14 mm Hg [99% CI -26.1 to -2.5], percentage change = -15.0%) anesthesia. Patients had faster emergence from xenon than from volatile anesthesia: eyes opening (versus all volatile agents: mean 4 vs 7 minutes, percentage change = -49.8% [99% CI -55.1% to -44.0%]), tracheal extubation (versus all volatile agents: mean 4 vs 8 minutes percentage change = -44.6% [99% CI -57.3% to -28.1%]), orientation (versus sevoflurane: mean 5 vs 10 minutes

microRNA-124-3p inhibits the progression of congenital hypothyroidism via targeting programmed cell death protein 6.

PubMed

Li, Wenjie; Song, Dongpo; Sun, Yingmei; Lv, Yanan; Lv, Jinfeng

2018-06-01

The incidence of congenital hypothyroidism (CH) in newborn infants ranges from 1 in 3,000 to 1 in 4,000. Previous studies have indicated the neuroprotective role of microRNA (miR)-124-3p, however the expression and role of miR-124-3p in CH remain unclear. Therefore, the present study was performed to investigate the role and precise molecular mechanism of miR-124-3p in CH. Propylthiouracil (50 mg/day) was injected into the stomach of pregnant rats from gestational day 15 until parturition in order to establish a thyroid hypofunction model. Newborn rats were divided into the following four groups: The control group; the thyroid hypofunction group; the miR-124-3p mimic group; and the miR-124-3p negative control group. Reverse transcription-quantitative polymerase chain reaction indicated that miR-124-3p was significantly decreased in the hippocampus of the thyroid hypofunction group compared with the control group. Bioinformatics software was used to predict mRNA targets recognized by miR-124-3p and the programmed cell death protein 6 (PDCD6) 3' untranslated region (UTR) was demonstrated to exhibit the seed sequence of miR-124-3p. The interaction between miRNA-124-3p and PDCD6 was then verified using a dual-luciferase reporter assay system. PDCD6 expression was significantly increased in the hippocampus of rats with CH compared with the control group. Flow cytometry was performed to investigate the effects of miR-124-3p on neuronal cell apoptosis and the results indicated that the apoptosis rate in the thyroid hypofunction group was significantly increased compared with the control group; this increase was reversed by transfection with miR-124-3p mimics. Western blot analysis was used to detect the levels of cleaved poly [ADP-ribose] polymerase (PARP), full-length PARP, caspase-3, B cell lymphoma-2 (Bcl-2) and Bcl-2-associated X protein (Bax) proteins. The results indicated that the expression of cleaved PARP, caspase-3 and Bax protein were significantly increased

Structural Basis for Xenon Inhibition in a Cationic Pentameric Ligand-Gated Ion Channel

PubMed Central

Sauguet, Ludovic; Fourati, Zeineb; Prangé, Thierry; Delarue, Marc; Colloc'h, Nathalie

2016-01-01

GLIC receptor is a bacterial pentameric ligand-gated ion channel whose action is inhibited by xenon. Xenon has been used in clinical practice as a potent gaseous anaesthetic for decades, but the molecular mechanism of interactions with its integral membrane receptor targets remains poorly understood. Here we characterize by X-ray crystallography the xenon-binding sites within both the open and “locally-closed” (inactive) conformations of GLIC. Major binding sites of xenon, which differ between the two conformations, were identified in three distinct regions that all belong to the trans-membrane domain of GLIC: 1) in an intra-subunit cavity, 2) at the interface between adjacent subunits, and 3) in the pore. The pore site is unique to the locally-closed form where the binding of xenon effectively seals the channel. A putative mechanism of the inhibition of GLIC by xenon is proposed, which might be extended to other pentameric cationic ligand-gated ion channels. PMID:26910105

Structural Basis for Xenon Inhibition in a Cationic Pentameric Ligand-Gated Ion Channel.

PubMed

Sauguet, Ludovic; Fourati, Zeineb; Prangé, Thierry; Delarue, Marc; Colloc'h, Nathalie

2016-01-01

GLIC receptor is a bacterial pentameric ligand-gated ion channel whose action is inhibited by xenon. Xenon has been used in clinical practice as a potent gaseous anaesthetic for decades, but the molecular mechanism of interactions with its integral membrane receptor targets remains poorly understood. Here we characterize by X-ray crystallography the xenon-binding sites within both the open and "locally-closed" (inactive) conformations of GLIC. Major binding sites of xenon, which differ between the two conformations, were identified in three distinct regions that all belong to the trans-membrane domain of GLIC: 1) in an intra-subunit cavity, 2) at the interface between adjacent subunits, and 3) in the pore. The pore site is unique to the locally-closed form where the binding of xenon effectively seals the channel. A putative mechanism of the inhibition of GLIC by xenon is proposed, which might be extended to other pentameric cationic ligand-gated ion channels.

Cell tracking with caged xenon: using cryptophanes as MRI reporters upon cellular internalization.

PubMed

Klippel, Stefan; Döpfert, Jörg; Jayapaul, Jabadurai; Kunth, Martin; Rossella, Federica; Schnurr, Matthias; Witte, Christopher; Freund, Christian; Schröder, Leif

2014-01-07

Caged xenon has great potential in overcoming sensitivity limitations for solution-state NMR detection of dilute molecules. However, no application of such a system as a magnetic resonance imaging (MRI) contrast agent has yet been performed with live cells. We demonstrate MRI localization of cells labeled with caged xenon in a packed-bed bioreactor working under perfusion with hyperpolarized-xenon-saturated medium. Xenon hosts enable NMR/MRI experiments with switchable contrast and selectivity for cell-associated versus unbound cages. We present MR images with 10(3) -fold sensitivity enhancement for cell-internalized, dual-mode (fluorescence/MRI) xenon hosts at low micromolar concentrations. Our results illustrate the capability of functionalized xenon to act as a highly sensitive cell tracer for MRI detection even without signal averaging. The method will bridge the challenging gap for translation to in vivo studies for the optimization of targeted biosensors and their multiplexing applications. Copyright © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Modeling Xenon Purification Systems in a Laser Inertial Fusion Engine

NASA Astrophysics Data System (ADS)

Hopkins, Ann; Gentile, Charles

2011-10-01

A Laser Inertial Fusion Engine (LIFE) is a proposed method to employ fusion energy to produce electricity for consumers. However, before it can be built and used as such, each aspect of a LIFE power plant must first be meticulously planned. We are in the process of developing and perfecting models for an exhaust processing and fuel recovery system. Such a system is especially essential because it must be able to recapture and purify expensive materials involved in the reaction so they may be reused. One such material is xenon, which is to be used as an intervention gas in the target chamber. Using Aspen HYSYS, we have modeled several subsystems for exhaust processing, including a subsystem for xenon recovery and purification. After removing hydrogen isotopes using lithium bubblers, we propose to use cryogenic distillation to purify the xenon from remaining contaminants. Aspen HYSYS allows us to analyze predicted flow rates, temperatures, pressures, and compositions within almost all areas of the xenon purification system. Through use of Aspen models, we hope to establish that we can use xenon in LIFE efficiently and in a practical manner.

Xenon preconditioning: the role of prosurvival signaling, mitochondrial permeability transition and bioenergetics in rats.

PubMed

Mio, Yasushi; Shim, Yon Hee; Richards, Ebony; Bosnjak, Zeljko J; Pagel, Paul S; Bienengraeber, Martin

2009-03-01

Similar to volatile anesthetics, the anesthetic noble gas xenon protects the heart from ischemia/reperfusion injury, but the mechanisms responsible for this phenomenon are not fully understood. We tested the hypothesis that xenon-induced cardioprotection is mediated by prosurvival signaling kinases that target mitochondria. Male Wistar rats instrumented for hemodynamic measurements were subjected to a 30 min left anterior descending coronary artery occlusion and 2 h reperfusion. Rats were randomly assigned to receive 70% nitrogen/30% oxygen (control) or three 5-min cycles of 70% xenon/30% oxygen interspersed with the oxygen/nitrogen mixture administered for 5 min followed by a 15 min memory period. Myocardial infarct size was measured using triphenyltetrazolium staining. Additional hearts from control and xenon-pretreated rats were excised for Western blotting of Akt and glycogen synthase kinase 3 beta (GSK-3beta) phosphorylation and isolation of mitochondria. Mitochondrial oxygen consumption before and after hypoxia/reoxygenation and mitochondrial permeability transition pore opening were determined. Xenon significantly (P < 0.05) reduced myocardial infarct size compared with control (32 +/- 4 and 59% +/- 4% of the left ventricular area at risk; mean +/- sd) and enhanced phosphorylation of Akt and GSK-3beta. Xenon pretreatment preserved state 3 respiration of isolated mitochondria compared with the results obtained in the absence of the gas. The Ca(2+) concentration required to induce mitochondrial membrane depolarization was larger in the presence compared with the absence of xenon pretreatment (78 +/- 17 and 56 +/- 17 microM, respectively). The phosphoinositol-3-kinase-kinase inhibitor wortmannin blocked the effect of xenon on infarct size and respiration. These results indicate that xenon preconditioning reduces myocardial infarct size, phosphorylates Akt, and GSK-3beta, preserves mitochondrial function, and inhibits Ca(2+)-induced mitochondrial permeability

Xenon Preconditioning Protects against Renal Ischemic-Reperfusion Injury via HIF-1α Activation

PubMed Central

Ma, Daqing; Lim, Ta; Xu, Jing; Tang, Haidy; Wan, Yanjie; Zhao, Hailin; Hossain, Mahmuda; Maxwell, Patrick H.; Maze, Mervyn

2009-01-01

The mortality rate from acute kidney injury after major cardiovascular operations can be as high as 60%, and no therapies have been proved to prevent acute kidney injury in this setting. Here, we show that preconditioning with the anesthetic gas xenon activates hypoxia-inducible factor 1α (HIF-1α) and its downstream effectors erythropoietin and vascular endothelial growth factor in a time-dependent manner in the kidneys of adult mice. Xenon increased the efficiency of HIF-1α translation via modulation of the mammalian target of rapamycin pathway. In a model of renal ischemia-reperfusion injury, xenon provided morphologic and functional renoprotection; hydrodynamic injection of HIF-1α small interfering RNA demonstrated that this protection is HIF-1α dependent. These results suggest that xenon preconditioning is a natural inducer of HIF-1α and that administration of xenon before renal ischemia can prevent acute renal failure. If these data are confirmed in the clinical setting, then preconditioning with xenon may be beneficial before procedures that temporarily interrupt renal perfusion. PMID:19144758

TCF4-Targeting miR-124 is Differentially Expressed amongst Dendritic Cell Subsets

PubMed Central

Han, Sun Murray; Na, Hye Young; Ham, Onju; Choi, Wanho; Sohn, Moah; Ryu, Seul Hye; In, Hyunju; Hwang, Ki-Chul

2016-01-01

Dendritic cells (DCs) are professional antigen-presenting cells that sample their environment and present antigens to naïve T lymphocytes for the subsequent antigen-specific immune responses. DCs exist in a range of distinct subpopulations including plasmacytoid DCs (pDCs) and classical DCs (cDCs), with the latter consisting of the cDC1 and cDC2 lineages. Although the roles of DC-specific transcription factors across the DC subsets have become understood, the posttranscriptional mechanisms that regulate DC development are yet to be elucidated. MicroRNAs (miRNAs) are pivotal posttranscriptional regulators of gene expression in a myriad of biological processes, but their contribution to the immune system is just beginning to surface. In this study, our in-house probe collection was screened to identify miRNAs possibly involved in DC development and function by targeting the transcripts of relevant mouse transcription factors. Examination of DC subsets from the culture of mouse bone marrow with Flt3 ligand identified high expression of miR-124 which was able to target the transcript of TCF4, a transcription factor critical for the development and homeostasis of pDCs. Further expression profiling of mouse DC subsets isolated from in vitro culture as well as via ex vivo purification demonstrated that miR-124 was outstandingly expressed in CD24+ cDC1 cells compared to in pDCs and CD172α+ cDC2 cells. These results imply that miR-124 is likely involved in the processes of DC subset development by posttranscriptional regulation of a transcription factor(s). PMID:26937233

Optical pumping and xenon NMR

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

Raftery, M. Daniel

1991-11-01

Nuclear Magnetic Resonance (NMR) spectroscopy of xenon has become an important tool for investigating a wide variety of materials, especially those with high surface area. The sensitivity of its chemical shift to environment, and its chemical inertness and adsorption properties make xenon a particularly useful NMR probe. This work discusses the application of optical pumping to enhance the sensitivity of xenon NMR experiments, thereby allowing them to be used in the study of systems with lower surface area. A novel method of optically-pumping 129Xe in low magnetic field below an NMR spectrometer and subsequent transfer of the gas to highmore » magnetic field is described. NMR studies of the highly polarized gas adsorbed onto powdered samples with low to moderate surface areas are now possible. For instance, NMR studies of optically-pumped xenon adsorbed onto polyacrylic acid show that xenon has a large interaction with the surface. By modeling the low temperature data in terms of a sticking probability and the gas phase xenon-xenon interaction, the diffusion coefficient for xenon at the surface of the polymer is determined. The sensitivity enhancement afforded by optical pumping also allows the NMR observation of xenon thin films frozen onto the inner surfaces of different sample cells. The geometry of the thin films results in interesting line shapes that are due to the bulk magnetic susceptibility of xenon. Experiments are also described that combine optical pumping with optical detection for high sensitivity in low magnetic field to observe the quadrupoler evolution of 131 Xe spins at the surface of the pumping cells. In cells with macroscopic asymmetry, a residual quadrupolar interaction causes a splitting in the 131Xe NMR frequencies in bare Pyrex glass cells and cells with added hydrogen.« less

Optical pumping and xenon NMR

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

Raftery, M.D.

1991-11-01

Nuclear Magnetic Resonance (NMR) spectroscopy of xenon has become an important tool for investigating a wide variety of materials, especially those with high surface area. The sensitivity of its chemical shift to environment, and its chemical inertness and adsorption properties make xenon a particularly useful NMR probe. This work discusses the application of optical pumping to enhance the sensitivity of xenon NMR experiments, thereby allowing them to be used in the study of systems with lower surface area. A novel method of optically-pumping [sup 129]Xe in low magnetic field below an NMR spectrometer and subsequent transfer of the gas tomore » high magnetic field is described. NMR studies of the highly polarized gas adsorbed onto powdered samples with low to moderate surface areas are now possible. For instance, NMR studies of optically-pumped xenon adsorbed onto polyacrylic acid show that xenon has a large interaction with the surface. By modeling the low temperature data in terms of a sticking probability and the gas phase xenon-xenon interaction, the diffusion coefficient for xenon at the surface of the polymer is determined. The sensitivity enhancement afforded by optical pumping also allows the NMR observation of xenon thin films frozen onto the inner surfaces of different sample cells. The geometry of the thin films results in interesting line shapes that are due to the bulk magnetic susceptibility of xenon. Experiments are also described that combine optical pumping with optical detection for high sensitivity in low magnetic field to observe the quadrupoler evolution of 131 Xe spins at the surface of the pumping cells. In cells with macroscopic asymmetry, a residual quadrupolar interaction causes a splitting in the [sup 131]Xe NMR frequencies in bare Pyrex glass cells and cells with added hydrogen.« less

Feasibility and cardiac safety of inhaled xenon in combination with therapeutic hypothermia following out-of-hospital cardiac arrest.

PubMed

Arola, Olli J; Laitio, Ruut M; Roine, Risto O; Grönlund, Juha; Saraste, Antti; Pietilä, Mikko; Airaksinen, Juhani; Perttilä, Juha; Scheinin, Harry; Olkkola, Klaus T; Maze, Mervyn; Laitio, Timo T

2013-09-01

Preclinical studies reveal the neuroprotective properties of xenon, especially when combined with hypothermia. The purpose of this study was to investigate the feasibility and cardiac safety of inhaled xenon treatment combined with therapeutic hypothermia in out-of-hospital cardiac arrest patients. An open controlled and randomized single-centre clinical drug trial (clinicaltrials.gov NCT00879892). A multipurpose ICU in university hospital. Thirty-six adult out-of-hospital cardiac arrest patients (18-80 years old) with ventricular fibrillation or pulseless ventricular tachycardia as initial cardiac rhythm. Patients were randomly assigned to receive either mild therapeutic hypothermia treatment with target temperature of 33°C (mild therapeutic hypothermia group, n=18) alone or in combination with xenon by inhalation, to achieve a target concentration of at least 40% (Xenon+mild therapeutic hypothermia group, n=18) for 24 hours. Thirty-three patients were evaluable (mild therapeutic hypothermia group, n=17; Xenon+mild therapeutic hypothermia group, n=16). Patients were treated and monitored according to the Utstein protocol. The release of troponin-T was determined at arrival to hospital and at 24, 48, and 72 hours after out-of-hospital cardiac arrest. The median end-tidal xenon concentration was 47% and duration of the xenon inhalation was 25.5 hours. The frequency of serious adverse events, including inhospital mortality, status epilepticus, and acute kidney injury, was similar in both groups and there were no unexpected serious adverse reactions to xenon during hospital stay. In addition, xenon did not induce significant conduction, repolarization, or rhythm abnormalities. Median dose of norepinephrine during hypothermia was lower in xenon-treated patients (mild therapeutic hypothermia group=5.30 mg vs Xenon+mild therapeutic hypothermia group=2.95 mg, p=0.06). Heart rate was significantly lower in Xenon+mild therapeutic hypothermia patients during hypothermia

A dual-phase xenon TPC for scintillation and ionisation yield measurements in liquid xenon

NASA Astrophysics Data System (ADS)

Baudis, Laura; Biondi, Yanina; Capelli, Chiara; Galloway, Michelle; Kazama, Shingo; Kish, Alexander; Pakarha, Payam; Piastra, Francesco; Wulf, Julien

2018-05-01

A small-scale, two-phase (liquid/gas) xenon time projection chamber ( Xurich II) was designed, constructed and is under operation at the University of Zürich. Its main purpose is to investigate the microphysics of particle interactions in liquid xenon at energies below 50 keV, which are relevant for rare event searches using xenon as target material. Here we describe in detail the detector, its associated infrastructure, and the signal identification algorithm developed for processing and analysing the data. We present the first characterisation of the new instrument with calibration data from an internal ^83{m} Kr source. The zero-field light yield is 15.0 and 14.0 photoelectrons/keV at 9.4 and 32.1 keV, respectively, and the corresponding values at an electron drift field of 1 kV/cm are 10.8 and 7.9 photoelectrons/keV. The charge yields at these energies are 28 and 31 electrons/keV, with the proportional scintillation yield of 24 photoelectrons per one electron extracted into the gas phase, and an electron lifetime of 200 μ s. The relative energy resolution, σ /E, is 11.9 and 5.8% at 9.4 and 32.1 keV, respectively using a linear combination of the scintillation and ionisation signals. We conclude with measurements of the electron drift velocity at various electric fields, and compare these to literature values.

Critical Viscosity of Xenon

NASA Technical Reports Server (NTRS)

2001-01-01

The Critical Viscosity of Xenon Experiment (CVX-2) on the STS-107 Research 1 mission in 2002 will measure the viscous behavior of liquid xenon, a heavy inert gas used in flash lamps and ion rocket engines, at its critical point. Resembling a tiny bit of window screen, the oscillator at the heart of CVX-2 will vibrate between two pairs of paddle-like electrodes. The slight bend in the shape of the mesh has no effect on the data. What counts are the mesh's displacement in the xenon fluid and the rate at which the displacement dampens. The unit shown here is encased in a small test cell and capped with a sapphire windown to contain the xenon at high pressure.

Scalability study of solid xenon

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

Yoo, J.; Cease, H.; Jaskierny, W. F.

2015-04-01

We report a demonstration of the scalability of optically transparent xenon in the solid phase for use as a particle detector above a kilogram scale. We employed a cryostat cooled by liquid nitrogen combined with a xenon purification and chiller system. A modified {\\it Bridgeman's technique} reproduces a large scale optically transparent solid xenon.

Xenon Fractionation and Archean Hydrogen Escape

NASA Technical Reports Server (NTRS)

Zahnle, K. J.

2015-01-01

Xenon is the heaviest gas found in significant quantities in natural planetary atmospheres. It would seem the least likely to escape. Yet there is more evidence for xenon escape from Earth than for any element other than helium and perhaps neon. The most straightforward evidence is that most of the radiogenic Xe from the decay of (129)I (half-life 15.7 Myr) and (244)Pu (half-life 81 Myr) that is Earth's birthright is missing. The missing xenon is often attributed to the impact erosion of early atmospheres of Earth and its ancestors. It is obvious that if most of the radiogenic xenon were driven off by impacts, most of the rest of the atmophiles fared the same fate. The other line of evidence is in the nonradiogenic isotopes of xenon and its silent partner, krypton. Atmospheric xenon is strongly mass fractionated (at about 4% per amu) compared to any known solar system source (Figure 1). This is in stark contrast to krypton, which may not be fractionated at all: atmospheric Kr is slightly heavier than solar Kr (at about 0.5% per amu), but it is the same as in carbonaceous chondrites. Nonradiogenic xenon is also under abundant relative to krypton (the so-called "missing xenon" problem). Together these observations imply that xenon has been subject to fractionating escape and krypton not.

Solid xenon radiation detectors

NASA Astrophysics Data System (ADS)

Dolinski, Michelle J.

2014-03-01

Cryogenic liquid xenon detectors have become a popular technology in the search for rare events, such as dark matter interactions and neutrinoless double beta decay. The power of the liquid xenon detector technology is in the combination of the ionization and scintillation signals, resulting in particle discrimination and improved energy resolution over the ionization-only signal. The improved energy resolution results from a unique anti-correlation phenomenon that has not been described from first principles. Solid xenon bolometers, under development at Drexel University, are expected to have excellent counting statistics in the phonon channel, with energy resolution of 0.1% or better. This additional energy channel may offer the final piece of the puzzle in understanding liquid xenon detector energy response. Supported by a grant from the Charles E. Kaufman Foundation.

Separation and purification of xenon

DOEpatents

Schlea, deceased, Carl Solomon

1978-03-14

Xenon is separated from a mixture of xenon and krypton by extractive distillation using carbon tetrafluoride as the partitioning agent. Krypton is flushed out of the distillation column with CF.sub.4 in the gaseous overhead stream while purified xenon is recovered from the liquid bottoms. The distillation is conducted at about atmospheric pressure or at subatmospheric pressure.

Toward molecular mechanism of xenon anesthesia: a link to studies of xenon complexes with small aromatic molecules.

PubMed

Andrijchenko, Natalya N; Ermilov, Alexander Yu; Khriachtchev, Leonid; Räsänen, Markku; Nemukhin, Alexander V

2015-03-19

The present study illustrates the steps toward understanding molecular mechanism of xenon anesthesia by focusing on a link to the structures and spectra of intermolecular complexes of xenon with small aromatic molecules. A primary cause of xenon anesthesia is attributed to inhibition of N-methyl-D-aspartate (NMDA) receptors by an unknown mechanism. Following the results of quantum mechanics/molecular mechanics (QM/MM) and molecular dynamics (MD) calculations we report plausible xenon action sites in the ligand binding domain of the NMDA receptor, which are due to interaction of xenon atoms with aromatic amino-acid residues. We rely in these calculations on computational protocols adjusted in combined experimental and theoretical studies of intermolecular complexes of xenon with phenol. Successful reproduction of vibrational shifts in molecular species upon complexation with xenon measured in low-temperature matrices allowed us to select a proper functional form in density functional theory (DFT) approach for use in QM subsystems, as well as to calibrate force field parameters for MD simulations. The results of molecular modeling show that xenon atoms can compete with agonists for a place in the corresponding protein cavity, thus indicating their active role in anesthetic action.

Minimum alveolar concentration (MAC) for sevoflurane and xenon at normothermia and hypothermia in newborn pigs.

PubMed

Liu, X; Dingley, J; Elstad, M; Scull-Brown, E; Steen, P A; Thoresen, M

2013-05-01

Neuroprotection from therapeutic hypothermia increases when combined with the anaesthetic gas xenon in animal studies. A clinical feasibility study of the combined treatment has been successfully undertaken in asphyxiated human term newborns. It is unknown whether xenon alone would be sufficient for sedation during hypothermia eliminating or reducing the need for other sedative or analgesic infusions in ventilated sick infants. Minimum alveolar concentration (MAC) of xenon is unknown in any neonatal species. Eight newborn pigs were anaesthetised with sevoflurane alone and then sevoflurane plus xenon at two temperatures. Pigs were randomised to start at either 38.5°C or 33.5°C. MAC for sevoflurane was determined using the claw clamp technique at the preset body temperature. For xenon MAC determination, a background of 0.5 MAC sevoflurane was used, and 60% xenon added to the gas mixture. The relationship between sevoflurane and xenon MAC is assumed to be additive. Xenon concentrations were changed in 5% steps until a positive clamp reaction was noted. Pigs' temperature was changed to the second target, and two MAC determinations for sevoflurane and 0.5 MAC sevoflurane plus xenon were repeated. MAC for sevoflurane was 4.1% [95% confidence interval (CI): 3.65-4.50] at 38.5°C and 3.05% (CI: 2.63-3.48) at 33.5°C, a significant reduction. MAC for xenon was 120% at 38.5°C and 116% at 33.5°C, not different. In newborn swine sevoflurane, MAC was temperature dependent, while xenon MAC was independent of temperature. There was large individual variability in xenon MAC, from 60% to 120%. © 2013 The Acta Anaesthesiologica Scandinavica Foundation.

Isotopic Enrichment of Boron in the Sputtering of Boron Nitride with Xenon Ions

NASA Technical Reports Server (NTRS)

Ray, P. K.; Shutthanandan, V.

1998-01-01

An experimental study is described to measure the isotopic enrichment of boron. Xenon ions from 100 eV to 1.5 keV were used to sputter a boron nitride target. An ion gun was used to generate the ion beam. The ion current density at the target surface was approximately 30 microA/sq cm. Xenon ions impinged on the target surface at 50 deg angle to the surface normal. Since boron nitride is an insulator, a flood electron gun was used in our experiments to neutralize the positive charge buildup on the target surface. The sputtered secondary ions of boron were detected by a quadrupole mass spectrometer. The spectrometer entrance aperture was located perpendicular to the ion beam direction and 10 mm away from the target surface. The secondary ion flux was observed to be enriched in the heavy isotopes at lower ion energies. The proportion of heavy isotopes in the sputtered secondary ion flux was found to decrease with increasing primary ion energy from 100 to 350 eV. Beyond 350 eV, light isotopes were sputtered preferentially. The light isotope enrichment factor was observed to reach an asymptotic value of 1.27 at 1.5 keV. This trend is similar to that of the isotopic enrichment observed earlier when copper was sputtered with xenon ions in the same energy range.

Critical Viscosity of Xenon

NASA Technical Reports Server (NTRS)

2001-01-01

The Critical Viscosity of Xenon Experiment (CVX-2) on the STS-107 Research 1 mission in 2002 will measure the viscous behavior of xenon, a heavy inert gas used in flash lamps and ion rocket engines, at its critical point. Because xenon near the critical point will collapse under its own weight, experiments on Earth (green line) are limited as they get closer (toward the left) to the critical point. CVX in the microgravity of space (red line) moved into unmeasured territory that scientists had not been able to reach.

Development of Solid Xenon Bolometers

NASA Astrophysics Data System (ADS)

Dolinski, Michelle; Hansen, Erin

2016-09-01

Cryogenic liquid xenon detectors have become a popular technology in the search for rare events, such as dark matter interactions and neutrinoless double beta decay. The power of liquid xenon detector technology is in the combination of ionization and scintillation signals, resulting in particle discrimination and improved energy resolution over the ionization-only signal. The improved energy resolution results from a microscopic anti-correlation phenomenon that has not been described from first principles. Solid xenon bolometers operated at 10 mK are expected to have excellent counting statistics in the phonon channel, with energy resolution of 0.1% or better. This additional energy channel may offer the final piece of the puzzle in understanding liquid xenon detector energy response. We present work toward the development and characterization of solid xenon bolometers at Drexel University. Funding for this project was provided by the Charles E. Kaufman Foundation of The Pittsburgh Foundation.

Search for WIMP inelastic scattering off xenon nuclei with XENON100

NASA Astrophysics Data System (ADS)

Aprile, E.; Aalbers, J.; Agostini, F.; Alfonsi, M.; Amaro, F. D.; Anthony, M.; Arneodo, F.; Barrow, P.; Baudis, L.; Bauermeister, B.; Benabderrahmane, M. L.; Berger, T.; Breur, P. A.; Brown, A.; Brown, E.; Bruenner, S.; Bruno, G.; Budnik, R.; Bütikofer, L.; Calvén, J.; Cardoso, J. M. R.; Cervantes, M.; Cichon, D.; Coderre, D.; Colijn, A. P.; Conrad, J.; Cussonneau, J. P.; Decowski, M. P.; de Perio, P.; di Gangi, P.; di Giovanni, A.; Diglio, S.; Eurin, G.; Fei, J.; Ferella, A. D.; Fieguth, A.; Fulgione, W.; Gallo Rosso, A.; Galloway, M.; Gao, F.; Garbini, M.; Geis, C.; Goetzke, L. W.; Greene, Z.; Grignon, C.; Hasterok, C.; Hogenbirk, E.; Itay, R.; Kaminsky, B.; Kazama, S.; Kessler, G.; Kish, A.; Landsman, H.; Lang, R. F.; Lellouch, D.; Levinson, L.; Lin, Q.; Lindemann, S.; Lindner, M.; Lombardi, F.; Lopes, J. A. M.; Manfredini, A.; Maris, I.; Marrodán Undagoitia, T.; Masbou, J.; Massoli, F. V.; Masson, D.; Mayani, D.; Messina, M.; Micheneau, K.; Molinario, A.; Mora, K.; Murra, M.; Naganoma, J.; Ni, K.; Oberlack, U.; Pakarha, P.; Pelssers, B.; Persiani, R.; Piastra, F.; Pienaar, J.; Pizzella, V.; Piro, M.-C.; Plante, G.; Priel, N.; Rauch, L.; Reichard, S.; Reuter, C.; Rizzo, A.; Rosendahl, S.; Rupp, N.; Dos Santos, J. M. F.; Sartorelli, G.; Scheibelhut, M.; Schindler, S.; Schreiner, J.; Schumann, M.; Scotto Lavina, L.; Selvi, M.; Shagin, P.; Silva, M.; Simgen, H.; Sivers, M. V.; Stein, A.; Thers, D.; Tiseni, A.; Trinchero, G.; Tunnell, C.; Vargas, M.; Wang, H.; Wang, Z.; Wei, Y.; Weinheimer, C.; Wulf, J.; Ye, J.; Zhang, Y.; Xenon Collaboration

2017-07-01

We present the first constraints on the spin-dependent, inelastic scattering cross section of weakly interacting massive particles (WIMPs) on nucleons from XENON100 data with an exposure of 7.64 ×103 kg .days . XENON100 is a dual-phase xenon time projection chamber with 62 kg of active mass, operated at the Laboratori Nazionali del Gran Sasso (LNGS) in Italy and designed to search for nuclear recoils from WIMP-nucleus interactions. Here we explore inelastic scattering, where a transition to a low-lying excited nuclear state of Xe 129 is induced. The experimental signature is a nuclear recoil observed together with the prompt deexcitation photon. We see no evidence for such inelastic WIMP-Xe 129 interactions. A profile likelihood analysis allows us to set a 90% C.L. upper limit on the inelastic, spin-dependent WIMP-nucleon cross section of 3.3 ×10-38 cm2 at 100 GeV /c2 . This is the most constraining result to date, and sets the pathway for an analysis of this interaction channel in upcoming, larger dual-phase xenon detectors.

miR-21 Contributes to Xenon-conferred Amelioration of Renal Ischemia–Reperfusion Injury in Mice

PubMed Central

Jia, Ping; Teng, Jie; Zou, Jianzhou; Fang, Yi; Zhang, Xiaoyan; Bosnjak, Zeljko J.; Liang, Mingyu; Ding, Xiaoqiang

2015-01-01

Background MicroRNAs participate in the regulation of numerous physiological and disease processes. The in vivo role of microRNAs in anesthetics-conferred organoprotection is unknown. Methods Mice were exposed for 2 h to either 70% xenon, or 70% nitrogen, 24 h before the induction of renal ischemia-reperfusion injury. The role of microRNA, miR-21, in renal protection conferred by the delayed xenon preconditioning was examined using in vivo knockdown of miR-21 and analysis of miR-21 target pathways. Results Xenon preconditioning provided morphologic and functional protection against renal ischemia-reperfusion injury (n = 6), characterized by attenuation of renal tubular damage, apoptosis, and oxidative stress. Xenon preconditioning significantly increased the expression of miR-21 in the mouse kidney. A locked nucleic acid-modified anti–miR-21, given before xenon preconditioning, knocked down miR-21 effectively, and exacerbated subsequent renal ischemia-reperfusion injury. Mice treated with anti–miR-21 and ischemia-reperfusion injury showed significantly higher serum creatinine than antiscrambled oligonucleotides-treated mice, 24 h after ischemia-reperfusion (1.37 ± 0.28 vs. 0.81 ± 0.14 mg/dl; n = 5; P < 0.05). Knockdown of miR-21 induced significant up-regulation of programmed cell death protein 4 and phosphatase and tensin homolog deleted on chromosome 10, two proapoptotic target effectors of miR-21, and resulted in significant down-regulation of phosphorylated protein kinase B and increased tubular cell apoptosis. In addition, xenon preconditioning up-regulated hypoxia-inducible factor-1α and its downstream effector vascular endothelial growth factor in a time-dependent manner. Knockdown of miR-21 resulted in a significant decrease of hypoxia-inducible factor-1α. Conclusions These results indicate that miR-21 contributes to the renoprotective effect of xenon preconditioning. PMID:23681145

miR-21 contributes to xenon-conferred amelioration of renal ischemia-reperfusion injury in mice.

PubMed

Jia, Ping; Teng, Jie; Zou, Jianzhou; Fang, Yi; Zhang, Xiaoyan; Bosnjak, Zeljko J; Liang, Mingyu; Ding, Xiaoqiang

2013-09-01

MicroRNAs participate in the regulation of numerous physiological and disease processes. The in vivo role of microRNAs in anesthetics-conferred organoprotection is unknown. Mice were exposed for 2 h to either 70% xenon, or 70% nitrogen, 24 h before the induction of renal ischemia-reperfusion injury. The role of microRNA, miR-21, in renal protection conferred by the delayed xenon preconditioning was examined using in vivo knockdown of miR-21 and analysis of miR-21 target pathways. Xenon preconditioning provided morphologic and functional protection against renal ischemia-reperfusion injury (n = 6), characterized by attenuation of renal tubular damage, apoptosis, and oxidative stress. Xenon preconditioning significantly increased the expression of miR-21 in the mouse kidney. A locked nucleic acid-modified anti-miR-21, given before xenon preconditioning, knocked down miR-21 effectively, and exacerbated subsequent renal ischemia-reperfusion injury. Mice treated with anti-miR-21 and ischemia-reperfusion injury showed significantly higher serum creatinine than antiscrambled oligonucleotides-treated mice, 24 h after ischemia-reperfusion (1.37 ± 0.28 vs. 0.81 ± 0.14 mg/dl; n = 5; P < 0.05). Knockdown of miR-21 induced significant up-regulation of programmed cell death protein 4 and phosphatase and tensin homolog deleted on chromosome 10, two proapoptotic target effectors of miR-21, and resulted in significant down-regulation of phosphorylated protein kinase B and increased tubular cell apoptosis. In addition, xenon preconditioning up-regulated hypoxia-inducible factor-1α and its downstream effector vascular endothelial growth factor in a time-dependent manner. Knockdown of miR-21 resulted in a significant decrease of hypoxia-inducible factor-1α. These results indicate that miR-21 contributes to the renoprotective effect of xenon preconditioning.

[How xenon works: neuro and cardioprotection mechanisms].

PubMed

Morais, Ricardo; Andrade, Luísa; Lourenço, André; Tavares, Jorge

2014-01-01

The Xenon, a noble gas, has anesthetics properties, associated with remarkable hemodynamic stability as well as cardioprotective, neuroprotective proprieties. Its physicochemical characteristics give him a quick induction and emergence of anesthesia, being free of deleterious effects in all organs and showing no teratogenicity. Such properties have led to a growing interest in improving the knowledge about this noble gas, in order to assess the mechanisms of neuro and cardioprotection induced and to assess the clinical indications for its use. Qualitative review of clinical trials on anesthesia with xenon. Studies were identified from MEDLINE and by hand-searching, using the following keywords: xenon, xenon anestesia, xenon neuroprotection, xenon cradioprotection. After several studies, including two randomized multicenter controlled trials, the use of xenon as an anesthetic in patients ASA I-II was approved in March 2007. However his use in clinical practice has been strongly limited by it's high price. It seems unlikely that the advantages it offers in relation to other anesthetics justify it's use in patients ASA I-II. Although, xenon may be a valuable asset in the reduction of co-morbilities and mortality in anesthesia of patients ASA III-IV, unfortunately, there are no large randomized control studies to prove it. Unfortunately, there are still no randomized or multicentric studies showing a favourable cost-benefit profile of xenon in ASA III-IV patients vs. other anaesthetics. The usefulness of xenon in Anesthesiology requires more studies to be defined.

Low-Energy Sputtering Studies of Boron Nitride with Xenon Ions

NASA Technical Reports Server (NTRS)

Ray, P. K.; Shutthanandan, V.

1999-01-01

Sputtering of boron nitride with xenon ions was investigated using secondary ion (SIMS) and secondary neutral (SNMS) mass spectrometry. The ions generated from the ion gun were incident on the target at an angle of 50' with respect to the surface'normal. The energy of ions ranged from 100 eV to 3 keV. A flood electron gun was used to neutralize the positive charge build-up on the target surface. The intensities of sputtered neutral and charged particles, including single atoms, molecules, and clusters, were measured as a function of ion energy. Positive SIMS spectra were dominated by the two boron isotopes whereas BN- and B- were the two major constituents of the negative SIMS spectra. Nitrogen could be detected only in the SNMS spectra. The intensity-energy curves of the sputtered particles were similar in shape. The knees in P-SIMS and SNMS intensity-energy curves appear at around I keV which is significantly higher that 100 to 200 eV energy range at which knees appear in the sputtering of medium and heavy elements by ions of argon and xenon. This difference in the position of the sputter yield knee between boron nitride and heavier targets is due to the reduced ion energy differences. The isotopic composition of secondary ions of boron were measured by bombarding boron nitride with xenon ions at energies ranging from 100 eV to 1.5 keV using a quadrupole mass spectrometer. An ion gun was used to generate the ion beam. A flood electron gun was used to neutralize the positive charge buildup on the target surface. The secondary ion flux was found to be enriched in heavy isotopes at lower incident ion energies. The heavy isotope enrichment was observed to decrease with increasing primary ion energy. Beyond 350 eV, light isotopes were sputtered preferentially with the enrichment increasing to an asymptotic value of 1.27 at 1.5 keV. The trend is similar to that of the isotopic enrichment observed earlier when copper was sputtered with xenon ions in the same energy

High-Rydberg Xenon Submillimeter-Wave Detector

NASA Technical Reports Server (NTRS)

Chutjian, Ara

1987-01-01

Proposed detector for infrared and submillimeter-wavelength radiation uses excited xenon atoms as Rydberg sensors instead of customary beams of sodium, potassium, or cesium. Chemically inert xenon easily stored in pressurized containers, whereas beams of dangerously reactive alkali metals must be generated in cumbersome, unreliable ovens. Xenon-based detector potential for infrared astronomy and for Earth-orbiter detection of terrestrial radiation sources. Xenon atoms excited to high energy states in two stages. Doubly excited atoms sensitive to photons in submillimeter wavelength range, further excited by these photons, then ionized and counted.

Critical Viscosity of Xenon

NASA Technical Reports Server (NTRS)

2001-01-01

The Critical Viscosity of Xenon Experiment (CVX-2) on the STS-107 Research 1 mission in 2002 will measure the viscous behavior of xenon, a heavy inert gas used in flash lamps and ion rocket engines, at its critical point. The sample cell at the heart of CVX-2 will sit inside a thermostat providing three layers of insulation. The cell itself comprises a copper body that conducts heat efficiently and smoothes out thermal variations that that would destroy the xenon's uniformity. Inside the cell, the oscillating screen viscometer element is supported between two pairs of electrodes that deflect the screen and then measure screen motion.

On the behavior of solutions of xenon in liquid n-alkanes: solubility of xenon in n-pentane and n-hexane.

PubMed

Bonifácio, Rui P M F; Martins, Luís F G; McCabe, Clare; Filipe, Eduardo J M

2010-12-09

The solubility of xenon in liquid n-pentane and n-hexane has been studied experimentally, theoretically, and by computer simulation. Measurements of the solubility are reported for xenon + n-pentane as a function of temperature from 254 to 305 K. The uncertainty in the experimental data is less than 0.15%. The thermodynamic functions of solvation such as the standard Gibbs energy, enthalpy, and entropy of solvation have been calculated from Henry's law coefficients for xenon + n-pentane solutions and also for xenon + n-hexane, which were reported in previous work. The results provide a further example of the similarity between the xenon + n-alkane interaction and the n-alkane + n-alkane interactions. Using the SAFT-VR approach we were able to quantitatively predict the experimental solubility for xenon in n-pentane and semiquantitatively that of xenon in n-hexane using simple Lorentz-Berthelot combining rules to describe the unlikely interaction. Henry's constants at infinite dilution for xenon + n-pentane and xenon + n-hexane were also calculated by Monte Carlo simulation using a united atom force field to describe the n-alkane and the Widom test particle insertion method.

In Vivo Measurement in Pigs of Wash-In Kinetics of Xenon at its Site of Action.

PubMed

Froeba, Gebhard; Adolph, Oliver

2016-01-01

Xenon (Xe) in many respects is an ideal anaesthetic agent. Its blood/gas partition coefficient is lower than that of any other anaesthetic, enabling rapid induction of and emergence from anaesthesia. While the whole body kinetics during wash-in of inhalational anaesthesia is well known, data describing the pharmacokinetics of xenon in the cerebral compartment at the site of action are still largely missing. In order to illuminate xenon's cerebral pharmacokinetics, we anaesthetised five pigs and measured arterial, mixed- and sagittal sinus-venous blood, as well as end-expiratory gas concentrations of xenon by gas chromatography-mass spectrometry (GCMS) up to 30 minutes after starting the anaesthetic gas mixture. Despite xenon's fast onset of effect the half-time for equilibration between xenon concentration in arterial blood and at the site of action is measured to be 1.49 ± 0.04 minutes versus 3.91 ± 0.1 minutes. Successful loading of xenon in the brain during inhalational anesthesia was accomplished after approximately 15 minutes although the end-expiratory xenon concentration reached a plateau after 7 minutes. Thus cerebral xenon uptake rate is only moderate, xenon fast onset of action being largely due to its extremely fast alveolar uptake. To ensure safety and precise control during anaesthesia we need a profound knowledge about to what extent the measured end-tidal concentrations reflect the drug concentrations in the target tissue. The results of this study expand our knowledge about the temporal characteristics of xenon´s pharmacokinetics at its site of action and provide the basis for appropriate clinical protocols and experimental designs of future studies.

Xenon for tunnelling analysis of the efflux pump component OprN.

PubMed

Ntsogo Enguéné, Yvette Véronique; Phan, Gilles; Garnier, Cyril; Ducruix, Arnaud; Prangé, Thierry; Broutin, Isabelle

2017-01-01

Tripartite efflux pumps are among the main actors responsible for antibiotics resistance in Gram-negative bacteria. In the last two decades, structural studies gave crucial information about the assembly interfaces and the mechanistic motions. Thus rigidifying the assembly seems to be an interesting way to hamper the drug efflux. In this context, xenon is a suitable probe for checking whether small ligands could act as conformational lockers by targeting hydrophobic cavities. Here we focus on OprN, the outer membrane channel of the MexEF efflux pump from Pseudomonas aeruginosa. After exposing OprN crystals to xenon gas pressure, 14 binding sites were observed using X-ray crystallography. These binding sites were unambiguously characterized in hydrophobic cavities of OprN. The major site is observed in the sensitive iris-like region gating the channel at the periplasmic side, built by the three key-residues Leu 405, Asp 109, and Arg 412. This arrangement defines along the tunnel axis a strong hydrophobic/polar gradient able to enhance the passive efflux mechanism of OprN. The other xenon atoms reveal strategic hydrophobic regions of the channel scaffold to target, with the aim to freeze the dynamic movements responsible of the open/close conformational equilibrium in OprN.

Xenon for tunnelling analysis of the efflux pump component OprN

PubMed Central

Garnier, Cyril; Ducruix, Arnaud; Broutin, Isabelle

2017-01-01

Tripartite efflux pumps are among the main actors responsible for antibiotics resistance in Gram-negative bacteria. In the last two decades, structural studies gave crucial information about the assembly interfaces and the mechanistic motions. Thus rigidifying the assembly seems to be an interesting way to hamper the drug efflux. In this context, xenon is a suitable probe for checking whether small ligands could act as conformational lockers by targeting hydrophobic cavities. Here we focus on OprN, the outer membrane channel of the MexEF efflux pump from Pseudomonas aeruginosa. After exposing OprN crystals to xenon gas pressure, 14 binding sites were observed using X-ray crystallography. These binding sites were unambiguously characterized in hydrophobic cavities of OprN. The major site is observed in the sensitive iris-like region gating the channel at the periplasmic side, built by the three key-residues Leu 405, Asp 109, and Arg 412. This arrangement defines along the tunnel axis a strong hydrophobic/polar gradient able to enhance the passive efflux mechanism of OprN. The other xenon atoms reveal strategic hydrophobic regions of the channel scaffold to target, with the aim to freeze the dynamic movements responsible of the open/close conformational equilibrium in OprN. PMID:28886086

Anticonvulsant effect of xenon on neonatal asphyxial seizures.

PubMed

Azzopardi, Denis; Robertson, Nicola J; Kapetanakis, Andrew; Griffiths, James; Rennie, Janet M; Mathieson, Sean R; Edwards, A David

2013-09-01

Xenon, a monoatomic gas with very high tissue solubility, is a non-competitive inhibitor of N-methyl-D-aspartate (NMDA) glutamate receptor, has antiapoptotic effects and is neuroprotective following hypoxic ischaemic injury in animals. Xenon may be expected to have anticonvulsant effects through glutamate receptor blockade, but this has not previously been demonstrated clinically. We examined seizure activity on the real time and amplitude integrated EEG records of 14 full-term infants with perinatal asphyxial encephalopathy treated within 12 h of birth with 30% inhaled xenon for 24 h combined with 72 h of moderate systemic hypothermia. Seizures were identified on 5 of 14 infants. Seizures stopped during xenon therapy but recurred within a few minutes of withdrawing xenon and stopped again after xenon was restarted. Our data show that subanaesthetic levels of xenon may have an anticonvulsant effect. Inhaled xenon may be a valuable new therapy in this hard-to-treat population.

PET imaging of β-glucuronidase activity by an activity-based 124I-trapping probe for the personalized glucuronide prodrug targeted therapy.

PubMed

Su, Yu-Cheng; Cheng, Ta-Chun; Leu, Yu-Ling; Roffler, Steve R; Wang, Jaw-Yuan; Chuang, Chih-Hung; Kao, Chien-Han; Chen, Kai-Chuan; Wang, Hsin-Ell; Cheng, Tian-Lu

2014-12-01

Beta-glucuronidase (βG) is a potential biomarker for cancer diagnosis and prodrug therapy. The ability to image βG activity in patients would assist in personalized glucuronide prodrug cancer therapy. However, whole-body imaging of βG activity for medical usage is not yet available. Here, we developed a radioactive βG activity-based trapping probe for positron emission tomography (PET). We generated a (124)I-tyramine-conjugated difluoromethylphenol beta-glucuronide probe (TrapG) to form (124)I-TrapG that could be selectively activated by βG for subsequent attachment of (124)I-tyramine to nucleophilic moieties near βG-expressing sites. We estimated the specificity of a fluorescent FITC-TrapG, the cytotoxicity of tyramine-TrapG, and the serum half-life of (124)I-TrapG. βG targeting of (124)I-TrapG in vivo was examined by micro-PET. The biodistribution of (131)I-TrapG was investigated in different organs. Finally, we imaged the endogenous βG activity and assessed its correlation with therapeutic efficacy of 9-aminocamptothecin glucuronide (9ACG) prodrug in native tumors. FITC-TrapG showed specific trapping at βG-expressing CT26 (CT26/mβG) cells but not in CT26 cells. The native TrapG probe possessed low cytotoxicity. (124)I-TrapG preferentially accumulated in CT26/mβG but not CT26 cells. Meanwhile, micro-PET and whole-body autoradiography results demonstrated that (124)I-TrapG signals in CT26/mβG tumors were 141.4-fold greater than in CT26 tumors. Importantly, Colo205 xenografts in nude mice that express elevated endogenous βG can be monitored by using infrared glucuronide trapping probes (NIR-TrapG) and suppressed by 9ACG prodrug treatment. (124)I-TrapG exhibited low cytotoxicity allowing long-term monitoring of βG activity in vivo to aid in the optimization of prodrug targeted therapy. ©2014 American Association for Cancer Research.

Simultaneous detection of xenon and krypton in equine plasma by gas chromatography-tandem mass spectrometry for doping control.

PubMed

Kwok, Wai Him; Choi, Timmy L S; So, Pui-Kin; Yao, Zhong-Ping; Wan, Terence S M

2017-02-01

Xenon can activate the hypoxia-inducible factors (HIFs). As such, it has been allegedly used in human sports for increasing erythropoiesis. Krypton, another noble gas with reported narcosis effect, can also be expected to be a potential and less expensive erythropoiesis stimulating agent. This has raised concern about the misuse of noble gases as doping agents in equine sports. The aim of the present study is to establish a method for the simultaneous detection of xenon and krypton in equine plasma for the purpose of doping control. Xenon- or krypton-fortified equine plasma samples were prepared according to reported protocols. The target noble gases were simultaneously detected by gas chromatography-triple quadrupole mass spectrometry using headspace injection. Three xenon isotopes at m/z 129, 131, and 132, and four krypton isotopes at m/z 82, 83, 84, and 86 were targeted in selected reaction monitoring mode (with the precursor ions and product ions at identical mass settings), allowing unambiguous identification of the target analytes. Limits of detection for xenon and krypton were about 19 pmol/mL and 98 pmol/mL, respectively. Precision for both analytes was less than 15%. The method has good specificity as background analyte signals were not observed in negative equine plasma samples (n = 73). Loss of analytes under different storage temperatures has also been evaluated. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

Postconditioning effects of argon or xenon on early graft function in a porcine model of kidney autotransplantation.

PubMed

De Deken, J; Rex, S; Lerut, E; Martinet, W; Monbaliu, D; Pirenne, J; Jochmans, I

2018-07-01

Ischaemia-reperfusion injury is inevitable during renal transplantation and can lead to delayed graft function and primary non-function. Preconditioning, reconditioning and postconditioning with argon and xenon protects against renal ischaemia-reperfusion injury in rodent models. The hypothesis that postconditioning with argon or xenon inhalation would improve graft function in a porcine renal autotransplant model was tested. Pigs (n = 6 per group) underwent left nephrectomy after 60 min of warm ischaemia (renal artery and vein clamping). The procured kidney was autotransplanted in a separate procedure after 18 h of cold storage, immediately after a right nephrectomy. Upon reperfusion, pigs were randomized to inhalation of control gas (70 per cent nitrogen and 30 per cent oxygen), argon (70 per cent and 30 per cent oxygen) or xenon (70 per cent and 30 per cent oxygen) for 2 h. The primary outcome parameter was peak plasma creatinine; secondary outcome parameters included further markers of graft function (creatinine course, urine output), graft injury (aspartate aminotransferase, heart-type fatty acid-binding protein, histology), apoptosis and autophagy (western blot, terminal deoxynucleotidyl transferase dUTP nick-end labelling (TUNEL) staining), inflammatory mediators and markers of cell survival/growth (mRNA and tissue protein quantification), and animal survival. Results are presented as median (i.q.r.). ANOVA and Kruskal-Wallis tests were used where indicated. Peak plasma creatinine levels were similar between the groups: control 20·8 (16·4-23·1) mg/dl, argon 21·4 (17·1-24·9) mg/dl and xenon 19·4 (17·5-21·0) mg/dl (P = 0·607). Xenon was associated with an increase in autophagy and proapoptotic markers. Creatinine course, urine output, injury markers, histology, survival and inflammatory mediators were not affected by the intervention. Postconditioning with argon or xenon did not improve kidney graft function in this

[Xenon: From rare gaz to doping product].

PubMed

Tassel, Camille; Le Daré, Brendan; Morel, Isabelle; Gicquel, Thomas

2016-04-01

Doping is defined as the use of processes or substances to artificially increase physical or mental performance. Xenon is a noble gas used as an anesthetic and recently as a doping agent. Xenon is neuroprotective as an antagonist of NMDA glutamate receptors. Xenon stimulates the synthesis of erythropoietin (EPO) by increase of hypoxia inducible factor (HIF). Xenon would be a new doping product, maintaining doping methods ahead of detection. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

Cryogenic readout for multiple VUV4 Multi-Pixel Photon Counters in liquid xenon

NASA Astrophysics Data System (ADS)

Di Giovanni, A.

2018-03-01

This work concerned the preliminary tests and characterization of a cryogenic preamplifier board for an array made of 16 S13370-3050CN (VUV4 family) Multi-Pixel Photon Counters manufactured by Hamamatsu and operated at liquid xenon temperature. The proposed prototype is based on the use of the Analog Devices AD8011 current feedback operational amplifier. The detector allows for single photon detection, making this device a promising choice for the future generation of neutrino and dark matter detectors based on liquid xenon targets.

Configuration interaction in charge exchange spectra of tin and xenon

NASA Astrophysics Data System (ADS)

D'Arcy, R.; Morris, O.; Ohashi, H.; Suda, S.; Tanuma, H.; Fujioka, S.; Nishimura, H.; Nishihara, K.; Suzuki, C.; Kato, T.; Koike, F.; O'Sullivan, G.

2011-06-01

Charge-state-specific extreme ultraviolet spectra from both tin ions and xenon ions have been recorded at Tokyo Metropolitan University. The electron cyclotron resonance source spectra were produced from charge exchange collisions between the ions and rare gas target atoms. To identify unknown spectral lines of tin and xenon, atomic structure calculations were performed for Sn14+-Sn17+ and Xe16+-Xe20+ using the Hartree-Fock configuration interaction code of Cowan (1981 The Theory of Atomic Structure and Spectra (Berkeley, CA: University of California Press)). The energies of the capture states involved in the single-electron process that occurs in these slow collisions were estimated using the classical over-barrier model.

Xenon (e,2e) triple differential cross sections

NASA Astrophysics Data System (ADS)

Mydlowski, Robert D.; Walters, H. R. J.; Whelan, Colm T.

2015-05-01

Recently there have been published some interesting experiments on the outer shell of xenon performed in doubly symmetric energy sharing arrangements. These experiments present a substantial challenge to theory, not only have we an extremely complex target but the kinematics are such that the key few body effects of exchange, distortion and post collisional electron-electron interaction (pci) and target polarization are likely to be at their strongest and the TDCS will be sensitive to them and their interference. Theoretical results will be presented and compared with experiment

Xenon lighting adjusted to plant requirements

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

Koefferlein, M.; Doehring, T.; Payer, H.D.

1994-12-31

The high luminous flux and spectral properties of xenon lamps would provide an ideal luminary for plant lighting if not excess IR radiation poses several problems for an application: the required filter systems reduce the irradiance at spectral regions of particular importance for plant development. Most of the economical drawbacks of xenon lamps are related to the difficult handling of that excess IR energy. Furthermore, the temporal variation of the xenon output depending on the oscillations of the applied AC voltage has to be considered for the plant development. However, xenon lamps outperform other lighting systems with respect to spectralmore » stability, immediate response, and maximum luminance. Therefore, despite considerable competition by other lighting techniques, xenon lamps provide a very useful tool for special purposes. In plant lighting however, they seem to play a less important role as other lamp and lighting developments can meet these particular requirements at lower costs.« less

Xenon Feed System Progress (Postprint)

DTIC Science & Technology

2006-06-13

development, assembly and test of an electric propulsion xenon feed system for a flight technology demonstration program. Major accomplishments...pressure transducer feedback, the PFCV has successfully fed xenon to a 200 watt Hall Effect Thruster in a Technology Demonstration Program. The feed

miR-124 suppresses glioblastoma growth and potentiates chemosensitivity by inhibiting AURKA

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

Qiao, Wanchen; Guo, Beisong; Zhou, Haichun

Glioblastoma (GBM) accounts for about half of all malignant brain cancers. Although the treatment strategies for glioblastoma develop rapidly, a considerable number of patients could not benefit from temozolomide (TMZ)-based chemotherapy. Here, we revealed a miR-124-AURKA axis that regulated glioblastoma growth and chemosensitivity. Mechanistically, AURKA was up-regulated in glioblastoma tissues and associated with poor overall survival. While overexpression of AURKA enhanced tumor growth, genetic or pharmacological inhibition of AURKA led to growth-inhibitory and chemopotentiating effects in glioblastoma. AURKA was further identified as a target of miR-124. Furthermore, our data showed that miR-124 down-regulated AURKA expression and subsequently suppressed cell growth.more » Re-expression of AURKA significantly rescued miR124-mediated proliferation repression and chemosensitivity. In conclusion, our results demonstrated that miR-124 inhibited glioblastoma growth and potentiated chemosensitivity by targeting AURKA, which may represent promising targets and rational therapeutic options for glioblastoma. - Highlights: • AURKA was overexpressed and associated with poor OS in GBM. • Targeting AURKA inhibits GBM growth in vitro and in vivo. • AURKA was further identified as a target of miR-124. • Re-expression of AURKA rescued miR-124-mediated growth suppression.« less

Lowering the radioactivity of the photomultiplier tubes for the XENON1T dark matter experiment

DOE PAGES

Aprile, E.; Agostini, F.; Alfonsi, M.; ...

2015-11-23

The low-background, VUV-sensitive 3-inch diameter photomultiplier tube R11410 has been developed by Hamamatsu for dark matter direct detection experiments using liquid xenon as the target material. We present the results from the joint effort between the XENON collaboration and the Hamamatsu company to produce a highly radio-pure photosensor (version R11410-21) for the XENON1T dark matter experiment. After introducing the photosensor and its components, we show the methods and results of the radioactive contamination measurements of the individual materials employed in the photomultiplier production. We then discuss the adopted strategies to reduce the radioactivity of the various PMT versions. Finally, wemore » detail the results from screening 286 tubes with ultra-low background germanium detectors, as well as their implications for the expected electronic and nuclear recoil background of the XENON1T experiment.« less

Supernova neutrino physics with xenon dark matter detectors: A timely perspective

NASA Astrophysics Data System (ADS)

Lang, Rafael F.; McCabe, Christopher; Reichard, Shayne; Selvi, Marco; Tamborra, Irene

2016-11-01

Dark matter detectors that utilize liquid xenon have now achieved tonne-scale targets, giving them sensitivity to all flavors of supernova neutrinos via coherent elastic neutrino-nucleus scattering. Considering for the first time a realistic detector model, we simulate the expected supernova neutrino signal for different progenitor masses and nuclear equations of state in existing and upcoming dual-phase liquid xenon experiments. We show that the proportional scintillation signal (S2) of a dual-phase detector allows for a clear observation of the neutrino signal and guarantees a particularly low energy threshold, while the backgrounds are rendered negligible during the supernova burst. XENON1T (XENONnT and LZ; DARWIN) experiments will be sensitive to a supernova burst up to 25 (35; 65) kpc from Earth at a significance of more than 5 σ , observing approximately 35 (123; 704) events from a 27 M⊙ supernova progenitor at 10 kpc. Moreover, it will be possible to measure the average neutrino energy of all flavors, to constrain the total explosion energy, and to reconstruct the supernova neutrino light curve. Our results suggest that a large xenon detector such as DARWIN will be competitive with dedicated neutrino telescopes, while providing complementary information that is not otherwise accessible.

The feasibility of using a portable xenon delivery device to permit earlier xenon ventilation with therapeutic cooling of neonates during ambulance retrieval.

PubMed

Dingley, John; Liu, Xun; Gill, Hannah; Smit, Elisa; Sabir, Hemmen; Tooley, James; Chakkarapani, Ela; Windsor, David; Thoresen, Marianne

2015-06-01

Therapeutic hypothermia is the standard of care after perinatal asphyxia. Preclinical studies show 50% xenon improves outcome, if started early. During a 32-patient study randomized between hypothermia only and hypothermia with xenon, 5 neonates were given xenon during retrieval using a closed-circuit incubator-mounted system. Without xenon availability during retrieval, 50% of eligible infants exceeded the 5-hour treatment window. With the transportable system, 100% were recruited. Xenon delivery lasted 55 to 120 minutes, using 174 mL/h (117.5-193.2) (median [interquartile range]), after circuit priming (1300 mL). Xenon delivery during ambulance retrieval was feasible, reduced starting delays, and used very little gas.

Adsorption of xenon on vicinal copper and platinum surfaces

NASA Astrophysics Data System (ADS)

Baker, Layton

The adsorption of xenon was studied on Cu(111), Cu(221), Cu(643) and on Pt(111), Pt(221), and Pt(531) using low energy electron diffraction (LEED), temperature programmed desorption (TPD) of xenon, and ultraviolet photoemission of adsorbed xenon (PAX). These experiments were performed to study the atomic and electronic structure of stepped and step-kinked, chiral metal surfaces. Xenon TPD and PAX were performed on each surface in an attempt to titrate terrace, step edge, and kink adsorption sites by adsorption energetics (TPD) and local work function differences (PAX). Due to the complex behavior of xenon on the vicinal copper and platinum metal surfaces, adsorption sites on these surfaces could not be adequately titrated by xenon TPD. On Cu(221) and Cu(643), xenon desorption from step adsorption sites was not apparent leading to the conclusion that the energy difference between terrace and step adsorption is minuscule. On Pt(221) and Pt(531), xenon TPD indicated that xenon prefers to bond at step edges and that the xenon-xenon interaction at step edges in repulsive but no further indication of step-kink adsorption was observed. The Pt(221) and Pt(531) TPD spectra indicated that the xenon overlayer undergoes strong compression near monolayer coverage on these surfaces due to repulsion between step-edge adsorbed xenon and other encroaching xenon atoms. The PAX experiments on the copper and platinum surfaces demonstrated that the step adsorption sites have lower local work functions than terrace adsorption sites and that higher step density leads to a larger separation in the local work function of terrace and step adsorption sites. The PAX spectra also indicated that, for all surfaces studied at 50--70 K, step adsorption is favored at low coverage but the step sites are not saturated until monolayer coverage is reached; this observation is due to the large entropy difference between terrace and step adsorption states and to repulsive interactions between xenon atoms

Critical Viscosity of Xenon investigators

NASA Technical Reports Server (NTRS)

2001-01-01

Dr. Dr. Robert F. Berg (right), principal investigator and Dr. Micheal R. Moldover (left), co-investigator, for the Critical Viscosity of Xenon (CVX/CVX-2) experiment. They are with the National Institutes of Standards and Technology, Gaithersburg, MD. The Critical Viscosity of Xenon Experiment (CVX-2) on the STS-107 Research 1 mission in 2002 will measure the viscous behavior of xenon, a heavy inert gas used in flash lamps and ion rocket engines, at its critical point. Although it does not easily combine with other chemicals, its viscosity at the critical point can be used as a model for a range of chemicals.

Functionalized xenon as a biosensor

PubMed Central

Spence, Megan M.; Rubin, Seth M.; Dimitrov, Ivan E.; Ruiz, E. Janette; Wemmer, David E.; Pines, Alexander; Yao, Shao Qin; Tian, Feng; Schultz, Peter G.

2001-01-01

The detection of biological molecules and their interactions is a significant component of modern biomedical research. In current biosensor technologies, simultaneous detection is limited to a small number of analytes by the spectral overlap of their signals. We have developed an NMR-based xenon biosensor that capitalizes on the enhanced signal-to-noise, spectral simplicity, and chemical-shift sensitivity of laser-polarized xenon to detect specific biomolecules at the level of tens of nanomoles. We present results using xenon “functionalized” by a biotin-modified supramolecular cage to detect biotin–avidin binding. This biosensor methodology can be extended to a multiplexing assay for multiple analytes. PMID:11535830

Recovering Residual Xenon Propellant for an Ion Propulsion System

NASA Technical Reports Server (NTRS)

Ganapathi, Gani; Skakkottai, P.; wu, Jiunn Jeng

2006-01-01

Future nuclear-powered Ion-Propulsion- System-propelled spacecraft such as Jupiter Icy Moon Orbiter (JIMO) will carry more than 10,000 kg of xenon propellant. Typically, a small percentage of this propellant cannot be used towards the end of the mission because of the pressure drop requirements for maintaining flow. For large missions such as JIMO, this could easily translate to over 250 kg of unusable xenon. A proposed system, the Xenon Recovery System (XRS), for recovering almost all of the xenon remaining in the tank, would include a cryopump in the form of a condenser/evaporator that would be alternatively cooled by a radiator, then heated electrically. When the pressure of the xenon in the tank falls below 0.7 MPa (100 psia), the previously isolated XRS will be brought online and the gas from the tank would enter the cryopump that is initially cooled to a temperature below saturation temperature of xenon. This causes xenon liquefaction and further cryopumping from the tank till the cryopump is full of liquid xenon. At this point, the cryopump is heated electrically by small heaters (70 to 80 W) to evaporate the liquid that is collected as high-pressure gas (<7 MPa; 1,000 psia) in an intermediate accumulator. Check valves between the tank and the XRS prevent the reverse flow of xenon during the heating cycle. The accumulator serves as the high-pressure source of xenon gas to the Xenon Feed System (XFS) downstream of the XRS. This cycle is repeated till almost all the xenon is recovered. Currently, this system is being baselined for JIMO.

Measuring and Modeling Xenon Uptake in Plastic Beta-Cells

NASA Astrophysics Data System (ADS)

Suarez, R.; Hayes, J. C.; Harper, W. W.; Humble, P.; Ripplinger, M. D.; Stephenson, D. E.; Williams, R. M.

2013-12-01

The precision of the stable xenon volume measurement in atmospheric monitoring radio-xenon systems is a critical parameter used to determine the activity concentration of a radio-xenon sample. Typically these types of systems use a plastic scintillating beta-cell as part of a beta-gamma detection scheme to measure the radioactivity present in the gas sample. Challenges arise when performing the stable xenon calculation during or after radioactive counting of the sample due to xenon uptake into the plastic beta-cells. Plastic beta cells can adsorb as much as 5% of the sample during counting. If quantification is performed after counting, the uptake of xenon into the plastic results in an underestimation of the xenon volume measurement. This behavior also causes what is typically known as 'memory effect' in the cell. Experiments were conducted using a small volume low pressure range thermal conductivity sensor to quantify the amount of xenon uptake into the cell over a given period of time. Understanding the xenon uptake in the cell provides a better estimate of the stable volume which improves the overall measurement capability of the system. The results from these experiments along with modeling will be presented.

The Long Non-Coding RNA XIST Interacted with MiR-124 to Modulate Bladder Cancer Growth, Invasion and Migration by Targeting Androgen Receptor (AR).

PubMed

Xiong, Yaoyao; Wang, Long; Li, Yuan; Chen, Minfeng; He, Wei; Qi, Lin

2017-01-01

Long non-coding RNA (lncRNA) X-inactive specific transcript (XIST) is involved in the progression of several tumors. The interaction between lncRNA and miRNA or miRNA's target genes is reported to play crucial roles in malignancy. In addition, Androgen receptor (AR) is considered to be involved in bladder cancer progression. In this study, we investigated the role of XIST in human bladder cancer and its interaction with miR-124 and AR. XIST and AR expression was detected in bladder tumor samples and cell lines. Effects of XIST and AR on bladder cancer cells growth, invasion and migration were analyzed. Bioinformatic analysis and luciferase assays were used to identify the interaction among XIST, AR and miR-124. The correlations of miR-124 with XIST and AR in bladder cancer samples were statistically analyzed. XIST and AR were upregulated in bladder cancer tissues and positively correlated. Higher XIST and AR expression were related to poorer TNM stage of bladder cancer. XIST knockdown reduced bladder cancer cells' proliferation, invasion and migration. While this inhibitory effect could be partially restored by AR overexpression. XIST inhibited miR-124 expression by directly targeting. Moreover, miR-124 could bind to the 3'UTR of AR to regulate its expression. MiR-124 inhibition partially restored the XIST knockdown-induced reduction of AR, c-myc, p27, MMP13 and MMP9 expression. In bladder cancer tissues, miR-124 level was inversely correlated with the expression of XIST and AR, respectively. These findings indicated that XIST might be an oncogenic lncRNA that promoted the bladder cancer growth, invasion and migration via miR-124 dependent AR regulation. © 2017 The Author(s). Published by S. Karger AG, Basel.

Anticipatory control of xenon in a pressurized water reactor

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

Impink, A.J. Jr.

1987-02-10

A method is described for automatically dampening xenon-135 spatial transients in the core of a pressurized water reactor having control rods which regulate reactor power level, comprising the steps of: measuring the neutron flu in the reactor core at a plurality of axially spaced locations on a real-time, on-line basis; repetitively generating from the neutron flux measurements, on a point-by-point basis, signals representative of the current axial distribution of xenon-135, and signals representative of the current rate of change of the axial distribution of xenon-135; generating from the xenon-135 distribution signals and the rate of change of xenon distribution signals,more » control signals for reducing the xenon transients; and positioning the control rods as a function of the control signals to dampen the xenon-135 spatial transients.« less

A target for production of radioxenons

NASA Technical Reports Server (NTRS)

Blue, J. W.; Leonard, R.; Jha, S.; Sodd, V. J.; Vincent, J. S.

1976-01-01

A liquid cesium target has been developed which allows the production and separate identification of the neutron deficient isotopes of xenon. The present report describes irradiations utilizing 34 to 41 MeV protons to produce millicurie quantities of Xe-127 and Xe-129m. At higher energies, however, the target could be used without modification to produce xenon isotopes as light as 119.

Circular RNA HIPK2 regulates astrocyte activation via cooperation of autophagy and ER stress by targeting MIR124-2HG.

PubMed

Huang, Rongrong; Zhang, Yuan; Han, Bing; Bai, Ying; Zhou, Rongbin; Gan, Guangming; Chao, Jie; Hu, Gang; Yao, Honghong

2017-10-03

Circular RNAs are a subclass of noncoding RNAs in mammalian cells; however, whether these RNAs are involved in the regulation of astrocyte activation is largely unknown. Here, we have shown that the circular RNA HIPK2 (circHIPK2) functions as an endogenous microRNA-124 (MIR124-2HG) sponge to sequester MIR124-2HG and inhibit its activity, resulting in increased sigma non-opioid intracellular receptor 1 (SIGMAR1/OPRS1) expression. Knockdown of circHIPK2 expression significantly inhibited astrocyte activation via the regulation of autophagy and endoplasmic reticulum (ER) stress through the targeting of MIR124-2HG and SIGMAR1. These findings were confirmed in vivo in mouse models, as microinjection of a circHIPK2 siRNA lentivirus into mouse hippocampi inhibited astrocyte activation induced by methamphetamine or lipopolysaccharide (LPS). These findings provide novel insights regarding the specific contribution of circHIPK2 to astrocyte activation in the context of drug abuse as well as for the treatment of a broad range of neuroinflammatory disorders.

Hyperpolarized xenon magnetic resonance of the lung and the brain

NASA Astrophysics Data System (ADS)

Venkatesh, Arvind Krishnamachari

2001-04-01

Hyperpolarized noble gas Magnetic Resonance Imaging (MRI) is a new diagnostic modality that has been used successfully for lung imaging. Xenon is soluble in blood and inhaled xenon is transported to the brain via circulating blood. Xenon also accumulates in the lipid rich white matter of the brain. Hyperpolarized xenon can hence be used as a tissue- sensitive probe of brain function. The goals of this study were to identify the NMR resonances of xenon in the rat brain and evaluate the role of hyperpolarized xenon for brain MRI. We have developed systems to produce sufficient volumes of hyperpolarized xenon for in vivo brain experiments. The specialized instrumentation developed include an apparatus for optical pump-cell manufacture and high purity gas manifolds for filling cells. A hyperpolarized gas delivery system was designed to ventilate small animals with hyperpolarized xenon for transport to the brain. The T1 of xenon dissolved in blood indicates that the lifetime of xenon in the blood is sufficient for significant magnetization to be transferred to distal tissues. A variety of carrier agents for intravenous delivery of hyperpolarized xenon were tested for transport to distal tissues. Using our new gas delivery system, high SNR 129Xe images of rat lungs were obtained. Spectroscopy with hyperpolarized xenon indicated that xenon was transported from the lungs to the blood and tissues with intact magnetization. After preliminary studies that indicated the feasibility for in vivo rat brain studies, experiments were performed with adult rats and young rats with different stages of white matter development. Both in vivo and in vitro experiments showed the prominence of one peak from xenon in the rat brain, which was assigned to brain lipids. Cerebral brain perfusion was calculated from the wash-out of the hyperpolarized xenon signal in the brain. An increase in brain perfusion during maturation was observed. These experiments showed that hyperpolarized xenon MRI

Xenon Treatment Protects against Remote Lung Injury after Kidney Transplantation in Rats.

PubMed

Zhao, Hailin; Huang, Han; Ologunde, Rele; Lloyd, Dafydd G; Watts, Helena; Vizcaychipi, Marcela P; Lian, Qingquan; George, Andrew J T; Ma, Daqing

2015-06-01

Ischemia-reperfusion injury (IRI) of renal grafts may cause remote organ injury including lungs. The authors aimed to evaluate the protective effect of xenon exposure against remote lung injury due to renal graft IRI in a rat renal transplantation model. For in vitro studies, human lung epithelial cell A549 was challenged with H2O2, tumor necrosis factor-α, or conditioned medium from human kidney proximal tubular cells (HK-2) after hypothermia-hypoxia insults. For in vivo studies, the Lewis renal graft was stored in 4°C Soltran preserving solution for 24 h and transplanted into the Lewis recipient, and the lungs were harvested 24 h after grafting. Cultured lung cells or the recipient after engraftment was exposed to 70% Xe or N2. Phospho (p)-mammalian target of rapamycin (mTOR), hypoxia-inducible factor-1α (HIF-1α), Bcl-2, high-mobility group protein-1 (HMGB-1), TLR-4, and nuclear factor κB (NF-κB) expression, lung inflammation, and cell injuries were assessed. Recipients receiving ischemic renal grafts developed pulmonary injury. Xenon treatment enhanced HIF-1α, which attenuated HMGB-1 translocation and NF-κB activation in A549 cells with oxidative and inflammatory stress. Xenon treatment enhanced p-mTOR, HIF-1α, and Bcl-2 expression and, in turn, promoted cell proliferation in the lung. Upon grafting, HMGB-1 translocation from lung epithelial nuclei was reduced; the TLR-4/NF-κB pathway was suppressed by xenon treatment; and subsequent tissue injury score (nitrogen vs. xenon: 26 ± 1.8 vs. 10.7 ± 2.6; n = 6) was significantly reduced. Xenon treatment confers protection against distant lung injury triggered by renal graft IRI, which is likely through the activation of mTOR-HIF-1α pathway and suppression of the HMGB-1 translocation from nuclei to cytoplasm.

Method for the simultaneous preparation of Radon-211, Xenon-125, Xenon-123, Astatine-211, Iodine-125 and Iodine-123

DOEpatents

Mirzadeh, Saed; Lambrecht, Richard M.

1987-01-01

A method for simultaneously preparing Radon-211, Astatine-211, Xenon-125, Xenon-123, Iodine-125 and Iodine-123 in a process that includes irradiating a fertile metal material then using a one-step chemical procedure to collect a first mixture of about equal amounts of Radon-211 and Xenon-125, and a separate second mixture of about equal amounts of Iodine-123 and Astatine-211.

The atmosphere of Mars: detection of krypton and xenon.

PubMed

Owen, T; Biemann, K; Rushneck, D R; Biller, J E; Howarth, D W; Lafleur, A L

1976-12-11

Krypton and xenon have been discovered in the martian atmosphere with the mass spectrometer on the second Viking lander. Krypton is more abundant than xenon. The relative abundances of the krypton isotopes appear normal, but the ratio of xenon-129 to xenon-132 is enhanced on Mars relative to the terrestrial value for this ratio. Some possible implications of these findings are discussed.

Radon depletion in xenon boil-off gas

NASA Astrophysics Data System (ADS)

Bruenner, S.; Cichon, D.; Lindemann, S.; Undagoitia, T. Marrodán; Simgen, H.

2017-03-01

An important background in detectors using liquid xenon for rare event searches arises from the decays of radon and its daughters. We report for the first time a reduction of ^{222}Rn in the gas phase above a liquid xenon reservoir. We show a reduction factor of ≳ 4 for the ^{222}Rn concentration in boil-off xenon gas compared to the radon enriched liquid phase. A semiconductor-based α -detector and miniaturized proportional counters are used to detect the radon. As the radon depletion in the boil-off gas is understood as a single-stage distillation process, this result establishes the suitability of cryogenic distillation to separate radon from xenon down to the 10^{-15} mol/mol level.

Critical Viscosity of Xenon

NASA Technical Reports Server (NTRS)

2001-01-01

The Critical Viscosity of Xenon Experiment (CVX-2) on the STS-107 Research 1 mission in 2002 will measure the viscous behavior of xenon, a heavy inert gas used in flash lamps and ion rocket engines, at its critical point. Shear thirning will cause a normally viscous fluid -- such as pie filling or whipped cream -- to deform and flow more readily under high shear conditions. In shear thinning, a pocket of fluid will deform and move one edge forward, as depicted here.

The physics of background discrimination in liquid xenon, and first results from Xenon10 in the hunt for WIMP dark matter

NASA Astrophysics Data System (ADS)

Dahl, Carl Eric

2009-06-01

The WIMP limit set by the Xenon10 experiment in 2007 signals a new era in direct detection of dark matter, with several large-scale liquid target detectors now under construction. A major challenge in these detectors will be to understand backgrounds at the level necessary to claim a positive WIMP signal. In liquid xenon, these backgrounds are dominated by electron recoils, which may be distinguished from the WIMP signal (nuclear recoils) by their higher charge-to-light ratio. During the construction and operation of Xenon10, the prototype detector Xed probed the physics of this discrimination. Particle interactions in liquid xenon both ionize and excite xenon atoms, giving charge and scintillation signals, respectively. Some fraction of ions recombine, reducing the charge signal and creating additional scintillation. The charge-to-light ratio, determined by the initial exciton-ion ratio and the ion recombination fraction, provides the basis for discrimination between electron and nuclear recoils. Intrinsic fluctuations in the recombination fraction limit discrimination. Changes in recombination induce an exact anti-correlation between charge and light, and when calibrated this anti-correlation distinguishes recombination fluctuations from uncorrelated fluctuations in the measured signals. We determine the mean recombination and recombination fluctuations as a function of energy and applied field for electron and nuclear recoils, finding that recombination fluctuations are already the limiting factor for discrimination above ~12 keVr (nuclear recoil energy). Below 12 keVr statistical fluctuations in the number of scintillation photons counted dominate, and we project a x6 improvement in background rejection with a x2 increase in light collection efficiency. We also build a simple recombination model that successfully reproduces the mean recombination in electron and nuclear recoils, including the surprising reversal of the expected trend for recombination with

Transdermal diffusion of xenon in vitro using diffusion cells

NASA Astrophysics Data System (ADS)

Verkhovsky, A.; Petrov, E.

2015-11-01

The aim of this research was to study the diffusion rate of xenon through guinea pig skin and how viscosity of cosmetic component capryl/capric triglyceride (CCT) facilitates to deliver xenon to surface of skin patches. They were placed in Franz cell for 24 hours and diffusion rate and permeability of xenon were calculated. Thus diffusion rate was 0.031 mg/hour*cm2 and permeability was 0.003 cm/hour. Using Brookfield viscometer it was shown that viscosity of CCT decreased upon increasing xenon concentration. Obtained results can be utilized in developing of new xenon containing drugs for topical administration.

Dark matter sensitivity of multi-ton liquid xenon detectors

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

Schumann, Marc; Bütikofer, Lukas; Baudis, Laura

2015-10-01

We study the sensitivity of multi ton-scale time projection chambers using a liquid xenon target, e.g., the proposed DARWIN instrument, to spin-independent and spin-dependent WIMP-nucleon scattering interactions. Taking into account realistic backgrounds from the detector itself as well as from neutrinos, we examine the impact of exposure, energy threshold, background rejection efficiency and energy resolution on the dark matter sensitivity. With an exposure of 200 t × y and assuming detector parameters which have been already demonstrated experimentally, spin-independent cross sections as low as 2.5 × 10{sup −49} cm{sup 2} can be probed for WIMP masses around 40 GeV/c{sup 2}. Additional improvementsmore » in terms of background rejection and exposure will further increase the sensitivity, while the ultimate WIMP science reach will be limited by neutrinos scattering coherently off the xenon nuclei.« less

Xenon migration behaviour in titanium nitride

NASA Astrophysics Data System (ADS)

Gavarini, S.; Toulhoat, N.; Peaucelle, C.; Martin, P.; Mende, J.; Pipon, Y.; Jaffrezic, H.

2007-05-01

Titanium nitride is one of the inert matrixes proposed to surround the fuel in gas cooled fast reactor (GFR) systems. These reactors operate at high temperature and necessitate refractory materials presenting a high chemical stability and good mechanical properties. A total retention of the most volatile fission products, such as Xe, I or Cs, by the inert matrix is needed during the in pile process. The thermal migration of xenon in TiN was studied by implanting 800 keV Xe++ ions in sintered samples at an ion fluence of 5 × 1015 cm-2. Annealing was performed at temperatures ranging from 1673 to 1923 K for 1 and 3 h. Xenon concentration profiles were studied by Rutherford backscattering spectrometry (RBS) using 2.5 MeV α-particles. The migration behaviour of xenon corresponds to a gas migration model. It is dominated by a surface directed transport with a slight diffusion component. The mean activation energy corresponding to the diffusion component was found to be 2.2 ± 0.3 eV and corresponds to the Brownian motion of xenon bubbles. The directed Xe migration can be interpreted in term of bubble transport using Evans model. This last process is mostly responsible for xenon release from TiN.

Electron drift in a large scale solid xenon

DOE PAGES

Yoo, J.; Jaskierny, W. F.

2015-08-21

A study of charge drift in a large scale optically transparent solid xenon is reported. A pulsed high power xenon light source is used to liberate electrons from a photocathode. The drift speeds of the electrons are measured using a 8.7 cm long electrode in both the liquid and solid phase of xenon. In the liquid phase (163 K), the drift speed is 0.193 ± 0.003 cm/μs while the drift speed in the solid phase (157 K) is 0.397 ± 0.006 cm/μs at 900 V/cm over 8.0 cm of uniform electric fields. Furthermore, it is demonstrated that a factor twomore » faster electron drift speed in solid phase xenon compared to that in liquid in a large scale solid xenon.« less

The search for dark matter in xenon: Innovative calibration strategies and novel search channels

NASA Astrophysics Data System (ADS)

Reichard, Shayne Edward

The direct detection dark matter experiment XENON1T became operational in early 2016, heralding the era of tonne-scale dark matter detectors. Direct detection experiments typically search for elastic scatters of dark matter particles off target nuclei. XENON1T's larger xenon target provides the advantage of stronger dark matter signals and lower background rates compared to its predecessors, XENON10 and XENON100; but, at the same time, calibration of the detector's response to backgrounds with traditional external sources becomes exceedingly more difficult. A 220Rn source is deployed on the XENON100 dark matter detector in order to address the challenges in calibration of tonne-scale liquid noble element detectors. I show that the subsequent 212Pb beta emission can be used for low-energy electronic recoil calibration in searches for dark matter. The isotope spreads throughout the entire active region of the detector, and its activity naturally decays below background level within a week after the source is closed. I find no increase in the activity of the troublesome 222Rn background after calibration. Alpha emitters are also distributed throughout the detector and facilitate calibration of its response to 222Rn. Using the delayed coincidence of 220Rn/216Po, I map for the first time the convective motion of particles in the XENON100 detector. Additionally, I make a competitive measurement of the half-life of 212Po, t1/2=293.9+/-(1.0)stat+/-(0.6)ns. In contrast to the elastic scattering of dark matter particles off nuclei, I explore inelastic scattering where the nucleus is excited to a low-lying state of 10-100 keV, with a subsequent prompt de-excitation. I use the inelastic structure factors for the odd-mass xenon isotopes based on state-of-the-art large-scale shell-model calculations with chiral effective field theory WIMP-nucleon currents, finding that the inelastic channel is comparable to or can dominate the elastic channel for momentum transfers around 150 Me

Xenon lighting adjusted to plant requirements

NASA Technical Reports Server (NTRS)

Koefferlein, M.; Doehring, T.; Payer, Hans D.; Seidlitz, H. K.

1994-01-01

Xenon lamps are available as low and high power lamps with relatively high efficiency and a relatively long lifetime up to several thousand hours. Different construction types of short-arc and long-arc lamps permit a good adaptation to various applications in projection and illumination techniques without substantial changes of the spectral quality. Hence, the xenon lamp was the best choice for professional technical purposes where high power at simultaneously good spectral quality of the light was required. However, technical development does not stand still. Between the luminous efficacy of xenon lamps of 25-50 lm/W and the theoretical limit for 'white light' of 250 lm/W is still much room for improvement. The present development mainly favors other lamp types, like metal halide lamps and fluorescent lamps for commercial lighting purposes. The enclosed sections deal with some of the properties of xenon lamps relevant to plant illumination; particularly the spectral aspects, the temporal characteristics of the emission, and finally the economy of xenon lamps will be addressed. Due to radiation exceeding the natural global radiation in both the ultraviolet (UV) and the infrared (IR) regions, filter techniques have to be included into the discussion referring to the requirements of plant illumination. Most of the presented results were obtained by investigations in the GSF phytotron or in the closed Phytocell chambers of the University of Erlangen. As our experiences are restricted to area plant illumination rather than spot lights our discussion will concentrate on low pressure long-arc xenon lamps which are commonly used for such plant illuminations. As the spectral properties of short-arc lamps do not differ much from those of long-arc lamps most of our conclusions will be valid for high pressure xenon lamps too. These lamps often serve as light sources for small sun simulators and for monochromators which are used for action spectroscopy of plant responses.

Differential Sputtering Behavior of Pyrolytic Graphite and Carbon-Carbon Composite Under Xenon Bombardment

NASA Technical Reports Server (NTRS)

Williams, John D.; Johnson, Mark L.; Williams, Desiree D.

2003-01-01

A differential sputter yield measurement technique is described, which consists of a quartz crystal monitor that is swept at constant radial distance from a small target region where a high current density xenon ion beam is aimed. This apparatus has been used to characterize the sputtering behavior of various forms of carbon including polycrystalline graphite, pyrolytic graphite, and PVD-infiltrated and pyrolized carbon-carbon composites. Sputter yield data are presented for pyrolytic graphite and carbon-carbon composite over a range of xenon ion energies from 200 eV to 1 keV and angles of incidence from 0 deg (normal incidence) to 60 deg .

Measuring xenon in human plasma and blood by gas chromatography/mass spectrometry.

PubMed

Thevis, Mario; Piper, Thomas; Geyer, Hans; Thomas, Andreas; Schaefer, Maximilian S; Kienbaum, Peter; Schänzer, Wilhelm

2014-07-15

Due to the favorable pharmacokinetic properties and minimal side effects of xenon, its use in modern anesthesia has been well accepted, and recent studies further demonstrated the intra- and postoperative neuro-, cardio-, and reno-protective action of the noble gas. Since the production of the hypoxia-inducible factor 1α (HIF-1α) and its downstream effector erythropoietin as well as noradrenalin reuptake inhibition have been found to play key roles in this context, the question arose as to whether the use of xenon is a matter for doping controls and preventive doping research. The aim of the present study was hence to evaluate whether the (ab)use of xenon can be detected from doping control samples with the instrumentation commonly available in sports drug testing laboratories. Plasma was saturated with xenon according to reported protocols, and the target analyte was measured by means of gas chromatography/time-of-flight and triple quadrupole mass spectrometry with headspace injection. Recording the accurate mass of three major xenon isotopes at m/z 128.9048, 130.9045 and 131.9042 allowed for the unequivocal identification of the analyte and the detection assay was characterized concerning limit of detection (LOD), intraday precision, and specificity as well as analyte recovery under different storage conditions. Xenon was detected in fortified plasma samples with detection limits of approximately 0.5 nmol/mL to 50 nmol/mL, depending on the type of mass spectrometer used. The method characteristics of intraday precision (coefficient of variation <20%) and specificity demonstrated the fitness-for-purpose of the analytical approach to unambiguously detect xenon at non-physiological concentrations in human plasma and blood. Eventually, authentic plasma and blood samples collected pre-, intra-, and post-operative (4, 8, and 24 h) were positively analyzed after storage for up to 30 h, and provided proof-of-concept for the developed assay. If relevant to

The Xenon1T Dark Matter Search Experiment

NASA Astrophysics Data System (ADS)

Aprile, Elena

The worldwide race towards direct dark matter detection in the form of Weakly Interacting Massive Particles (WIMPs) has been dramatically accelerated by the remarkable progress and evolution of liquid xenon time projection chambers (LXeTPCs). With a realistic discovery potential, Xenon100 has already reached a sensitivity of 7 × 10-45 cm2, and continues to accrue data at the Laboratori Nazionali del Gran Sasso (LNGS) in Italy towards its ultimate sensitivity reach at the σ SI ˜ 2 × 10-45 cm2 level for the spin-independent WIMP-nucleon cross-section. To fully explore the favoured parameter space for WIMP dark matter in search of a first robust and statistically significant discovery, or to confirm any hint of a signal from Xenon100, the next phase of the Xenon program will be a detector at the ton scale - Xenon1T. The Xenon1T detector, based on 2.2 ton of LXe viewed by low radioactivity photomultiplier tubes and housed in a water Cherenkov muon veto at LNGS, is presented. With an experimental aim of probing WIMP interaction cross-sections above of order σ SI ˜ 2 × 10-47 cm2 within 2 years of operation, Xenon1T will provide the sensitivity to probe a particularly favourable region of electroweak physics on a timescale compatible with complementary ground and satellite based indirect searches and with accelerator dark matter searches at the LHC. Indeed, for a σ SI ˜ 10-45 cm2 and 100 GeV/c2 WIMP mass, Xenon1T could detect of order 100 events in this exposure, providing statistics for placing significant constraints on the WIMP mass.

Genetically encoded reporters for hyperpolarized xenon magnetic resonance imaging

NASA Astrophysics Data System (ADS)

Shapiro, Mikhail G.; Ramirez, R. Matthew; Sperling, Lindsay J.; Sun, George; Sun, Jinny; Pines, Alexander; Schaffer, David V.; Bajaj, Vikram S.

2014-07-01

Magnetic resonance imaging (MRI) enables high-resolution non-invasive observation of the anatomy and function of intact organisms. However, previous MRI reporters of key biological processes tied to gene expression have been limited by the inherently low molecular sensitivity of conventional 1H MRI. This limitation could be overcome through the use of hyperpolarized nuclei, such as in the noble gas xenon, but previous reporters acting on such nuclei have been synthetic. Here, we introduce the first genetically encoded reporters for hyperpolarized 129Xe MRI. These expressible reporters are based on gas vesicles (GVs), gas-binding protein nanostructures expressed by certain buoyant microorganisms. We show that GVs are capable of chemical exchange saturation transfer interactions with xenon, which enables chemically amplified GV detection at picomolar concentrations (a 100- to 10,000-fold improvement over comparable constructs for 1H MRI). We demonstrate the use of GVs as heterologously expressed indicators of gene expression and chemically targeted exogenous labels in MRI experiments performed on living cells.

MicroRNA-124 controls human vascular smooth muscle cell phenotypic switch via Sp1.

PubMed

Tang, Yangfeng; Yu, Shangyi; Liu, Yang; Zhang, Jiajun; Han, Lin; Xu, Zhiyun

2017-09-01

Phenotypic switch of vascular smooth muscle cells (VSMCs) plays an important role in the pathogenesis of atherosclerosis and aortic dissection. However, the mechanisms of phenotypic modulation are still unclear. MicroRNAs have emerged as important regulators of VSMC function. We recently found that microRNA-124 (miR-124) was downregulated in proliferative vascular diseases that were characterized by a VSMC phenotypic switch. Therefore, we speculated that the aberrant expression of miR-124 might play a critical role in human aortic VSMC phenotypic switch. Using quantitative RT-PCR, we found that miR-124 was dramatically downregulated in the aortic media of clinical specimens of the dissected aorta and correlated with molecular markers of the contractile VSMC phenotype. Overexpression of miR-124 by mimicking transfection significantly attenuated platelet-derived growth factor-BB-induced human aortic VSMC proliferation and phenotypic switch. Furthermore, we identified specificity protein 1 (Sp1) as the downstream target of miR-124. A luciferase reporter assay was used to confirm direct miR-124 targeting of the 3'-untranslated region of the Sp1 gene and repression of Sp1 expression in human aortic VSMCs. Furthermore, constitutively active Sp1 in miR-124-overexpressing VSMCs reversed the antiproliferative effects of miR-124. These results demonstrated a novel mechanism of miR-124 modulation of VSMC phenotypic switch by targeting Sp1 expression. NEW & NOTEWORTHY Previous studies have demonstrated that miR-124 is involved in the proliferation of a variety of cell types. However, miRNAs are expressed in a tissue-specific manner. We first identified miR-124 as a critical regulator in human aortic vascular smooth muscle cell differentiation, proliferation, and phenotype switch by targeting the 3'-untranslated region of specificity protein 1. Copyright © 2017 the American Physiological Society.

The XENON100 Dark Matter Experiment: Design, Construction, Calibration and 2010 Search Results with Improved Measurement of the Scintillation Response of Liquid Xenon to Low-Energy Nuclear Recoils

NASA Astrophysics Data System (ADS)

Plante, Guillaume

An impressive array of astrophysical observations suggest that 83% of the matter in the universe is in a form of non-luminous, cold, collisionless, non-baryonic dark matter. Several extensions of the Standard Model of particle physics aimed at solving the hierarchy problem predict stable weakly interacting massive particles (WIMPs) that could naturally have the right cosmological relic abundance today to compose most of the dark matter if their interactions with normal matter are on the order of a weak scale cross section. These candidates also have the added benefit that their properties and interaction rates can be computed in a well defined particle physics model. A considerable experimental effort is currently under way to uncover the nature of dark matter. One method of detecting WIMP dark matter is to look for its interactions in terrestrial detectors where it is expected to scatter off nuclei. In 2007, the XENON10 experiment took the lead over the most sensitive direct detection dark matter search in operation, the CDMS II experiment, by probing spin-independent WIMP-nucleon interaction cross sections down to sigmachi N ˜ 5 x 10-44 cm 2 at 30 GeV/c2. Liquefied noble gas detectors are now among the technologies at the forefront of direct detection experiments. Liquid xenon (LXe), in particular, is a well suited target for WIMP direct detection. It is easily scalable to larger target masses, allows discrimination between nuclear recoils and electronic recoils, and has an excellent stopping power to shield against external backgrounds. A particle losing energy in LXe creates both ionization electrons and scintillation light. In a dual-phase LXe time projection chamber (TPC) the ionization electrons are drifted and extracted into the gas phase where they are accelerated to amplify the charge signal into a proportional scintillation signal. These two signals allow the three-dimensional localization of events with millimeter precision and the ability to

The Xenon record of Earth's early differentiaiton

NASA Astrophysics Data System (ADS)

Peto, M. K.; Mukhopadhyay, S.; Kelley, K. A.

2011-12-01

Xenon isotopes in mantle derived rocks provide information on the early differentiation of the silicate mantle of our planet. {131,132 134,136}Xe isotopes are produced by the spontaneous fission of two different elements: the now extinct radionuclide 244Pu, and the long-lived 238U. These two parent nuclides, however, yield rather different proportion of fissiogenic Xenon isotopes. Hence, the proportion of Pu- to U-derived fission xenon is indicative of the degree and rate of outgassing of a mantle reservoir. Recent data obtained from Iceland in our lab confirm that the Xenon isotopic composition of the plume source(s) is characterized by lower 136Xe/130Xe ratios than the MORB source and the Iceland plume is more enriched in the Pu-derived Xenon component. These features are interpreted as reflecting different degrees of outgassing and appear not to be the result of preferential recycling of Xenon to the deep mantle. To further investigate how representative the Icelandic measurements might be of other mantle plumes, we measured noble gases (He, Ne, Ar, Xe) in gas-rich basalt glasses from the Rochambeau Ridge (RR) in the Northern Lau Basin. Recent work suggests the presence of a "Samoan-like" OIB source in the northern Lau Basin and our measurements were performed on samples with plume-like 3He/4He ratios (15-28 RA) [1]. The Xenon isotopic measurements indicate that the maximum measured 136Xe/130Xe ratios in the Rochambeau samples are similar to Iceland. In particular, for one of the gas rich samples we were able to obtain 77 different isotopic measurements through step-crushing. Preliminary investigation of this sample suggests higher Pu- to U-derived fission Xenon than in MORBs. To quantitatively evaluate the degree and rate of outgassing of the plume and MORB reservoirs, particularly during the first few hundred million years of Earth's history, we have modified a geochemical reservoir model that was previously developed to investigate mantle overturn and mixing

Xenon. Now More than Ever.

NASA Astrophysics Data System (ADS)

Zahnle, K. J.

2017-12-01

Xenon is one of the major goals of proposed missions to Venus. This talk explains why xenon is important to understanding the evolution of Venus's atmosphere. Implications for the historic climate of Venus add a new wrinkle in the story. Xenon's 9 stable isotopes can tell us much about the contrasting histories of Earth, Mars, and Venus. Earth's atmospheric Xe is highly mass fractionated compared to any known solar system source. Moreover, Earth's Xe/Kr ratio is low. It would seem that our heaviest gas has been escaping. What is even more remarkable, Xe escape took place for billions of years until the advent of an O2 atmosphere (Srinivasan EPSL 31:129 (1976); Pujol et al. EPSL 308:298 (2011); Avice et al. Nature Comm 8 (2017)). (ii) Earth's original xenon - what Pepin named U-Xe and claimed was the true solar Xe - had not been seen anywhere else until this year, when the secret parent of U-Xe was found hiding in Comet 67P/Churyumov-Gerasimenko by Rosetta (Marty et al. Science 356:1069 (2017)). Apparently 20% of Earth's xenon came from this kind of comet. This has obvious consequences for volatiles in general. Mars's Xe is also strongly mass fractionated, but its original Xe is indistinguishable from solar Xe, which means that Xe escape is a planetary process that operated in parallel on the two planets. (iii) 7% of Earth's 129Xe are radiogenic daughters of extinct 129I, half-life 15.7 Myrs. This is only 1% of the radiogenic 129Xe that Earth would have had had Earth retained its full cosmic birthright. The missing 129Xe can be interpreted as dating the Moon-forming impact to 100 Myrs after the solar system formed. Venus will be different. Xenon loss probably requires escape as an ion, and therefore it likely depends on hydrogen escape and an organized planetary magnetic field. Xenon escape during Earth's Archean implies that hydrogen was abundant and that the planetary magnetic field was strong. Venus will have seen a different history of escape, so that the mass

Critical Viscosity of Xenon

NASA Technical Reports Server (NTRS)

2001-01-01

The Critical Viscosity of Xenon Experiment (CVX-2) on the STS-107 Research 1 mission in 2001 will measure the viscous behavior of xenon, a heavy inert gas used in flash lamps and ion rocket engines, at its critical point. The thermostat for CVX sits inside the white cylinder on a support structure that is placed inside a pressure canister. A similar canister holds the electronics and control systems. The CVX-2 arrangement is identical. The principal investigator is Dr. Robert F. Berg (not shown) of the National Institutes of Standards and Technology, Gaithersburg, MD. This is a detail view of MSFC 0100143.

Results from the XENON10 and the Race to Detect Dark Matter with Noble Liquids

ScienceCinema

Shutt, Tom [Case Western Reserve, Cleveland, Ohio, United States

2017-12-09

Detectors based on liquid noble gases have the potential to revolutionize the direct search for WIMP dark matter. The XENON10 experiment, of which I am a member, has recently announced the results from it's first data run and is now the leading WIMP search experiment. This and other experiments using xenon, argon and neon have the potential to rapidly move from the current kg-scale target mass to the ton scale and well beyond. This should allow a (nearly) definitive test or discovery of dark matter if it is in the form of weakly interacting massive particles.

Xenon Blocks Neuronal Injury Associated with Decompression

PubMed Central

Blatteau, Jean-Eric; David, Hélène N.; Vallée, Nicolas; Meckler, Cedric; Demaistre, Sebastien; Lambrechts, Kate; Risso, Jean-Jacques; Abraini, Jacques H.

2015-01-01

Despite state-of-the-art hyperbaric oxygen (HBO) treatment, about 30% of patients suffering neurologic decompression sickness (DCS) exhibit incomplete recovery. Since the mechanisms of neurologic DCS involve ischemic processes which result in excitotoxicity, it is likely that HBO in combination with an anti-excitotoxic treatment would improve the outcome in patients being treated for DCS. Therefore, in the present study, we investigated the effect of the noble gas xenon in an ex vivo model of neurologic DCS. Xenon has been shown to provide neuroprotection in multiple models of acute ischemic insults. Fast decompression compared to slow decompression induced an increase in lactate dehydrogenase (LDH), a well-known marker of sub-lethal cell injury. Post-decompression administration of xenon blocked the increase in LDH release induced by fast decompression. These data suggest that xenon could be an efficient additional treatment to HBO for the treatment of neurologic DCS. PMID:26469983

Xenon Blocks Neuronal Injury Associated with Decompression.

PubMed

Blatteau, Jean-Eric; David, Hélène N; Vallée, Nicolas; Meckler, Cedric; Demaistre, Sebastien; Lambrechts, Kate; Risso, Jean-Jacques; Abraini, Jacques H

2015-10-15

Despite state-of-the-art hyperbaric oxygen (HBO) treatment, about 30% of patients suffering neurologic decompression sickness (DCS) exhibit incomplete recovery. Since the mechanisms of neurologic DCS involve ischemic processes which result in excitotoxicity, it is likely that HBO in combination with an anti-excitotoxic treatment would improve the outcome in patients being treated for DCS. Therefore, in the present study, we investigated the effect of the noble gas xenon in an ex vivo model of neurologic DCS. Xenon has been shown to provide neuroprotection in multiple models of acute ischemic insults. Fast decompression compared to slow decompression induced an increase in lactate dehydrogenase (LDH), a well-known marker of sub-lethal cell injury. Post-decompression administration of xenon blocked the increase in LDH release induced by fast decompression. These data suggest that xenon could be an efficient additional treatment to HBO for the treatment of neurologic DCS.

Xenon Acquisition Strategies for High-Power Electric Propulsion NASA Missions

NASA Technical Reports Server (NTRS)

Herman, Daniel A.; Unfried, Kenneth G.

2015-01-01

The benefits of high-power solar electric propulsion (SEP) for both NASA's human and science exploration missions combined with the technology investment from the Space Technology Mission Directorate have enabled the development of a 50kW-class SEP mission. NASA mission concepts developed, including the Asteroid Redirect Robotic Mission, and those proposed by contracted efforts for the 30kW-class demonstration have a range of xenon propellant loads from 100's of kg up to 10,000 kg. A xenon propellant load of 10 metric tons represents greater than 10% of the global annual production rate of xenon. A single procurement of this size with short-term delivery can disrupt the xenon market, driving up pricing, making the propellant costs for the mission prohibitive. This paper examines the status of the xenon industry worldwide, including historical xenon supply and pricing. The paper discusses approaches for acquiring on the order of 10 MT of xenon propellant considering realistic programmatic constraints to support potential near-term NASA missions. Finally, the paper will discuss acquisitions strategies for mission campaigns utilizing multiple high-power solar electric propulsion vehicles requiring 100's of metric tons of xenon over an extended period of time where a longer term acquisition approach could be implemented.

Relaxation channels of multi-photon excited xenon clusters

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

Serdobintsev, P. Yu.; Melnikov, A. S.; Department of Physics, St. Petersburg State University, Saint Petersburg 198904

2015-09-21

The relaxation processes of the xenon clusters subjected to multi-photon excitation by laser radiation with quantum energies significantly lower than the thresholds of excitation of atoms and ionization of clusters were studied. Results obtained by means of the photoelectron spectroscopy method showed that desorption processes of excited atoms play a significant role in the decay of two-photon excited xenon clusters. A number of excited states of xenon atoms formed during this process were discovered and identified.

Magnetic resonance imaging of convection in laser-polarized xenon

NASA Technical Reports Server (NTRS)

Mair, R. W.; Tseng, C. H.; Wong, G. P.; Cory, D. G.; Walsworth, R. L.

2000-01-01

We demonstrate nuclear magnetic resonance (NMR) imaging of the flow and diffusion of laser-polarized xenon (129Xe) gas undergoing convection above evaporating laser-polarized liquid xenon. The large xenon NMR signal provided by the laser-polarization technique allows more rapid imaging than one can achieve with thermally polarized gas-liquid systems, permitting shorter time-scale events such as rapid gas flow and gas-liquid dynamics to be observed. Two-dimensional velocity-encoded imaging shows convective gas flow above the evaporating liquid xenon, and also permits the measurement of enhanced gas diffusion near regions of large velocity variation.

DFT-MD simulations of shocked Xenon

NASA Astrophysics Data System (ADS)

Magyar, Rudolph J.; Mattsson, Thomas R.

2009-03-01

Xenon is not only a technologically important element used in laser technologies, jet propulsion and dental anesthesia, but it is also arguably the simplest material in which to study the metal-insulator transition at high pressure. Because of its closed shell electronic configuration, Xenon is often assumed to be chemically inert, interacting almost entirely through the van der Waals interaction, and at liquid density, is typically modeled well using Leonard-Jones potentials. However, such modeling has a limited range of validity as Xenon is known to form compounds at normal conditions and likely exhibits considerably more chemistry at higher densities when hybridization of occupied orbitals becomes significant. In this talk, we present DFT-MD simulations of shocked liquid Xenon with the goal of developing an improved equation of state. The relative importance of the van der Waals interaction compared to other Coulomb interactions is considered, and estimates of the relative accuracy of various density functionals are quantified. Sandia is a multiprogram laboratory operated by Sandia Corporation, a Lockheed Martin Company, for the United States Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000.

Evidence of charge exchange pumping in calcium-xenon system

NASA Technical Reports Server (NTRS)

Chubb, D. L.

1973-01-01

Charge exchange between xenon ions and calcium atoms may produce an inversion between the 5s or 4d and 4p energy levels of the calcium ions. A low power flowing xenon plasma seeded with calcium was utilized to determine if charge exchange or electron collisions populate the 5s and 4d levels Ca(+). Line intensity ratios proportional to the density ratios n5s/n4p and n4d/n4p were measured. From the dependence of these intensity ratios on power input to the xenon plasma it was concluded that charge exchange pumping of the 5s and 4d levels predominates over electron collisional pumping of these levels. Also, by comparing intensity ratios obtained using argon and krypton in place of xenon with those obtained in xenon the same conclusion was made.

Xenon Purification Research and Development for the LZ Dark Matter Experiment

NASA Astrophysics Data System (ADS)

Pech, Katherin

2013-04-01

The LZ Experiment is a next generation dark matter detector based on the current LUX detector design, with a 7-ton active volume. Although many research and development breakthroughs were achieved for the 350 kg LUX detector, the large volume scaling required for LZ presents a new set of design challenges that need to be overcome. Because the search for WIMP-like dark matter requires ultra low background experiments, the xenon target material in the LZ detector must meet purity specifications beyond what is commercially available. This challenge is two-fold. The xenon must contain extremely low amounts of electronegative impurities such as oxygen, which attenuate the charge signal. Additionally, it must also have very little of the inert isotope Kr-85, a beta-emitter that can obscure the dark matter signal in the detector volume. The purity requirements for the LUX experiment have been achieved, but the factor of 20 scaling in volume for LZ and increased demands for sensitivity mean that new research and development work must be done to increase our xenon purification capabilities. This talk will focus on the efforts being done at Case Western Reserve University to meet these strict purity requirements for the LZ Experiment.

Neuroprotection against traumatic brain injury by xenon, but not argon, is mediated by inhibition at the N-methyl-D-aspartate receptor glycine site.

PubMed

Harris, Katie; Armstrong, Scott P; Campos-Pires, Rita; Kiru, Louise; Franks, Nicholas P; Dickinson, Robert

2013-11-01

Xenon, the inert anesthetic gas, is neuroprotective in models of brain injury. The authors investigate the neuroprotective mechanisms of the inert gases such as xenon, argon, krypton, neon, and helium in an in vitro model of traumatic brain injury. The authors use an in vitro model using mouse organotypic hippocampal brain slices, subjected to a focal mechanical trauma, with injury quantified by propidium iodide fluorescence. Patch clamp electrophysiology is used to investigate the effect of the inert gases on N-methyl-D-aspartate receptors and TREK-1 channels, two molecular targets likely to play a role in neuroprotection. Xenon (50%) and, to a lesser extent, argon (50%) are neuroprotective against traumatic injury when applied after injury (xenon 43±1% protection at 72 h after injury [N=104]; argon 30±6% protection [N=44]; mean±SEM). Helium, neon, and krypton are devoid of neuroprotective effect. Xenon (50%) prevents development of secondary injury up to 48 h after trauma. Argon (50%) attenuates secondary injury, but is less effective than xenon (xenon 50±5% reduction in secondary injury at 72 h after injury [N=104]; argon 34±8% reduction [N=44]; mean±SEM). Glycine reverses the neuroprotective effect of xenon, but not argon, consistent with competitive inhibition at the N-methyl-D-aspartate receptor glycine site mediating xenon neuroprotection against traumatic brain injury. Xenon inhibits N-methyl-D-aspartate receptors and activates TREK-1 channels, whereas argon, krypton, neon, and helium have no effect on these ion channels. Xenon neuroprotection against traumatic brain injury can be reversed by increasing the glycine concentration, consistent with inhibition at the N-methyl-D-aspartate receptor glycine site playing a significant role in xenon neuroprotection. Argon and xenon do not act via the same mechanism.

Xenon ventilation during therapeutic hypothermia in neonatal encephalopathy: a feasibility study.

PubMed

Dingley, John; Tooley, James; Liu, Xun; Scull-Brown, Emma; Elstad, Maja; Chakkarapani, Ela; Sabir, Hemmen; Thoresen, Marianne

2014-05-01

Therapeutic hypothermia has become standard of care in newborns with moderate and severe neonatal encephalopathy; however, additional interventions are needed. In experimental models, breathing xenon gas during cooling offers long-term additive neuroprotection. This is the first xenon feasibility study in cooled infants. Xenon is expensive, requiring a closed-circuit delivery system. Cooled newborns with neonatal encephalopathy were eligible for this single-arm, dose-escalation study if clinically stable, under 18 hours of age and requiring less than 35% oxygen. Xenon duration increased stepwise from 3 to 18 hours in 14 subjects; 1 received 25% xenon and 13 received 50%. Respiratory, cardiovascular, neurologic (ie, amplitude-integrated EEG, seizures), and inflammatory (C-reactive protein) effects were examined. The effects of starting or stopping xenon rapidly or slowly were studied. Three matched control subjects per xenon treated subject were selected from our cooling database. Follow-up was at 18 months using mental developmental and physical developmental indexes of the Bayley Scales of Infant Development II. No adverse respiratory or cardiovascular effects, including post-extubation stridor, were seen. Xenon increased sedation and suppressed seizures and background electroencephalographic activity. Seizures sometimes occurred during rapid weaning of xenon but not during slow weaning. C-reactive protein levels were similar between groups. Hourly xenon consumption was 0.52 L. Three died, and 7 of 11 survivors had mental and physical developmental index scores ≥70 at follow-up. Breathing 50% xenon for up to 18 hours with 72 hours of cooling was feasible, with no adverse effects seen with 18 months' follow-up. Copyright © 2014 by the American Academy of Pediatrics.

Purging means and method for Xenon arc lamps

NASA Technical Reports Server (NTRS)

Miller, C. G. (Inventor)

1973-01-01

High pressure Xenon short-arc lamp with two reservoirs which are selectively connectable to the lamp's envelope is described. One reservoir contains an absorbent which will absorb both Xenon and contaminant gases such as CO2 and O2. The absorbent temperature is controlled to evacuate the envelope of both the Xenon and the contaminant gases. The temperature of the absorbent is then raised to desorb only clean Xenon while retaining the contaminant gases, thereby clearing the envelope of the contaminant gases. The second reservoir contains a gas whose specific purpose is, to remove the objectional metal film which deposits gradually on the interior surface of the lamp envelope during normal arc operation. The origin of the film is metal transferred from the cathode of the arc lamp by sputtering or other gas transfer processes.

Plutonium-fission xenon found in Earth's mantle

PubMed

Kunz; Staudacher; Allegre

1998-05-08

Data from mid-ocean ridge basalt glasses indicate that the short-lived radionuclide plutonium-244 that was present during an early stage of the development of the solar system is responsible for roughly 30 percent of the fissiogenic xenon excesses in the interior of Earth today. The rest of the fissiogenic xenon can be ascribed to the spontaneous fission of still live uranium-238. This result, in combination with the refined determination of xenon-129 excesses from extinct iodine-129, implies that the accretion of Earth was finished roughly 50 million to 70 million years after solar system formation and that the atmosphere was formed by mantle degassing.

MiX: a position sensitive dual-phase liquid xenon detector

NASA Astrophysics Data System (ADS)

Stephenson, S.; Haefner, J.; Lin, Q.; Ni, K.; Pushkin, K.; Raymond, R.; Schubnell, M.; Shutty, N.; Tarlé, G.; Weaverdyck, C.; Lorenzon, W.

2015-10-01

The need for precise characterization of dual-phase xenon detectors has grown as the technology has matured into a state of high efficacy for rare event searches. The Michigan Xenon detector was constructed to study the microphysics of particle interactions in liquid xenon across a large energy range in an effort to probe aspects of radiation detection in liquid xenon. We report the design and performance of a small 3D position sensitive dual-phase liquid xenon time projection chamber with high light yield (Ly122=15.2 pe/keV at zero field), long electron lifetime (τ > 200 μs), and excellent energy resolution (σ/E = 1% for 1,333 keV gamma rays in a drift field of 200 V/cm). Liquid xenon time projection chambers with such high energy resolution may find applications not only in dark matter direct detection searches, but also in neutrinoless double beta decay experiments and other applications.

Assessing the depth of hypnosis of xenon anaesthesia with the EEG.

PubMed

Stuttmann, Ralph; Schultz, Arthur; Kneif, Thomas; Krauss, Terence; Schultz, Barbara

2010-04-01

Xenon was approved as an inhaled anaesthetic in Germany in 2005 and in other countries of the European Union in 2007. Owing to its low blood/gas partition coefficient, xenons effects on the central nervous system show a fast onset and offset and, even after long xenon anaesthetics, the wake-up times are very short. The aim of this study was to examine which electroencephalogram (EEG) stages are reached during xenon application and whether these stages can be identified by an automatic EEG classification. Therefore, EEG recordings were performed during xenon anaesthetics (EEG monitor: Narcotrend®). A total of 300 EEG epochs were assessed visually with regard to the EEG stages. These epochs were also classified automatically by the EEG monitor Narcotrend® using multivariate algorithms. There was a high correlation between visual and automatic classification (Spearman's rank correlation coefficient r=0.957, prediction probability Pk=0.949). Furthermore, it was observed that very deep stages of hypnosis were reached which are characterised by EEG activity in the low frequency range (delta waves). The burst suppression pattern was not seen. In deep hypnosis, in contrast to the xenon EEG, the propofol EEG was characterised by a marked superimposed higher frequency activity. To ensure an optimised dosage for the single patient, anaesthetic machines for xenon should be combined with EEG monitoring. To date, only a few anaesthetic machines for xenon are available. Because of the high price of xenon, new and further developments of machines focus on optimizing xenon consumption.

An ultra-low background PMT for liquid xenon detectors

DOE PAGES

Akerib, D. S.; Bai, X.; Bernard, E.; ...

2012-11-15

Results are presented from radioactivity screening of two models of photomultiplier tubes designed for use in current and future liquid xenon experiments. The Hamamatsu 5.6 cm diameter R8778 PMT, used in the LUX dark matter experiment, has yielded a positive detection of four common radioactive isotopes: 238U, 232Th, 40K, and 60Co. Screening of LUX materials has rendered backgrounds from other detector materials subdominant to the R8778 contribution. A prototype Hamamatsu 7.6 cm diameter R11410 MOD PMT has also been screened, with benchmark isotope counts measured at <0.4 238U / <0.3 232Th / < 8.3 40K / 2.0+-0.2 60Co mBq/PMT. This represents a large reduction, equal to a change of xmore » $$\\frac{1}{24}$$ 238U / x $$\\frac{1}{9}$$ 232Th / x $$\\frac{1}{8}$$ 40K per PMT, between R8778 and R11410 MOD, concurrent with a doubling of the photocathode surface area (4.5 cm to 6.4 cm diameter). 60Co measurements are comparable between the PMTs, but can be significantly reduced in future R11410 MOD units through further material selection. Assuming PMT activity equal to the measured 90% upper limits, Monte Carlo estimates indicate that replacement of R8778 PMTs with R11410 MOD PMTs will change LUX PMT electron recoil background contributions by a factor of x $$\\frac{1}{25}$$ after further material selection for 60Co reduction, and nuclear recoil backgrounds by a factor of \\times $$\\frac{1}{36}$$. The strong reduction in backgrounds below the measured R8778 levels makes the R11410 MOD a very competitive technology for use in large-scale liquid xenon detectors.« less

Hugoniot measurements of double-shocked precompressed dense xenon plasmas

NASA Astrophysics Data System (ADS)

Zheng, J.; Chen, Q. F.; Gu, Y. J.; Chen, Z. Y.

2012-12-01

The current partially ionized plasmas models for xenon show substantial differences since the description of pressure and thermal ionization region becomes a formidable task, prompting the need for an improved understanding of dense xenon plasmas behavior at above 100 GPa. We performed double-shock compression experiments on dense xenon to determine accurately the Hugoniot up to 172 GPa using a time-resolved optical radiation method. The planar strong shock wave was produced using a flyer plate impactor accelerated up to ˜6 km/s with a two-stage light-gas gun. The time-resolved optical radiation histories were acquired by using a multiwavelength channel optical transience radiance pyrometer. Shock velocity was measured and mass velocity was determined by the impedance-matching methods. The experimental equation of state of dense xenon plasmas are compared with the self-consistent fluid variational calculations of dense xenon in the region of partial ionization over a wide range of pressures and temperatures.

Antiapoptotic activity of argon and xenon

PubMed Central

Spaggiari, Sabrina; Kepp, Oliver; Rello-Varona, Santiago; Chaba, Kariman; Adjemian, Sandy; Pype, Jan; Galluzzi, Lorenzo; Lemaire, Marc; Kroemer, Guido

2013-01-01

Although chemically non-reactive, inert noble gases may influence multiple physiological and pathological processes via hitherto uncharacterized physical effects. Here we report a cell-based detection system for assessing the effects of pre-defined gas mixtures on the induction of apoptotic cell death. In this setting, the conventional atmosphere for cell culture was substituted with gas combinations, including the same amount of oxygen (20%) and carbon dioxide (5%) but 75% helium, neon, argon, krypton, or xenon instead of nitrogen. The replacement of nitrogen with noble gases per se had no effects on the viability of cultured human osteosarcoma cells in vitro. Conversely, argon and xenon (but not helium, neon, and krypton) significantly limited cell loss induced by the broad-spectrum tyrosine kinase inhibitor staurosporine, the DNA-damaging agent mitoxantrone and several mitochondrial toxins. Such cytoprotective effects were coupled to the maintenance of mitochondrial integrity, as demonstrated by means of a mitochondrial transmembrane potential-sensitive dye and by assessing the release of cytochrome c into the cytosol. In line with this notion, argon and xenon inhibited the apoptotic activation of caspase-3, as determined by immunofluorescence microscopy coupled to automated image analysis. The antiapoptotic activity of argon and xenon may explain their clinically relevant cytoprotective effects. PMID:23907115

Nuclear spin-spin coupling in a van der Waals-bonded system: xenon dimer.

PubMed

Vaara, Juha; Hanni, Matti; Jokisaari, Jukka

2013-03-14

Nuclear spin-spin coupling over van der Waals bond has recently been observed via the frequency shift of solute protons in a solution containing optically hyperpolarized (129)Xe nuclei. We carry out a first-principles computational study of the prototypic van der Waals-bonded xenon dimer, where the spin-spin coupling between two magnetically non-equivalent isotopes, J((129)Xe - (131)Xe), is observable. We use relativistic theory at the four-component Dirac-Hartree-Fock and Dirac-density-functional theory levels using novel completeness-optimized Gaussian basis sets and choosing the functional based on a comparison with correlated ab initio methods at the nonrelativistic level. J-coupling curves are provided at different levels of theory as functions of the internuclear distance in the xenon dimer, demonstrating cross-coupling effects between relativity and electron correlation for this property. Calculations on small Xe clusters are used to estimate the importance of many-atom effects on J((129)Xe - (131)Xe). Possibilities of observing J((129)Xe - (131)Xe) in liquid xenon are critically examined, based on molecular dynamics simulation. A simplistic spherical model is set up for the xenon dimer confined in a cavity, such as in microporous materials. It is shown that the on the average shorter internuclear distance enforced by the confinement increases the magnitude of the coupling as compared to the bulk liquid case, rendering J((129)Xe - (131)Xe) in a cavity a feasible target for experimental investigation.

Mechanistic Insights into Xenon Inhibition of NMDA Receptors from MD Simulations

PubMed Central

Liu, Lu Tian; Xu, Yan; Tang, Pei

2010-01-01

Inhibition of N-methyl-D-aspartate (NMDA) receptors has been viewed as a primary cause of xenon anesthesia, yet the mechanism is unclear. Here, we investigated interactions between xenon and the ligand-binding domain (LBD) of a NMDA receptor and examined xenon-induced structural and dynamical changes that are relevant to functional changes of the NMDA receptor. Several comparative molecular dynamics simulations were performed on two X-ray structures representing the open- and closed-cleft LBD of the NMDA receptor. We identified plausible xenon action sites in the LBD, including those nearby agonist sites, in the hinge region, and at the interface between two subunits. The xenon binding energy varies from −5.3 to −0.7 kcal/mol. Xenon's effect on the NMDA receptor is conformation-dependent and is produced through both competitive and non-competitive mechanisms. Xenon can promote cleft opening in the absence of agonists and consequently stabilizes the closed channel. Xenon can also bind at the interface of two subunits, alter the inter-subunit interaction, and lead to a reduction of the distance between GT-links. This reduction corresponds to a rearrangement of the channel toward a direction of pore size decreasing, implying a closed or desensitized channel. In addition to these non-competitive actions, xenon was found to weaken the glutamate binding, which could lead to low agonist efficacy and appear as competitive inhibition. PMID:20560662

Circular RNA WDR77 target FGF-2 to regulate vascular smooth muscle cells proliferation and migration by sponging miR-124.

PubMed

Chen, Junjiang; Cui, Lianqun; Yuan, Jingliang; Zhang, Yuqing; Sang, Hongjun

2017-12-09

Increasing evidences have revealed the important role of circular RNAs (circRNAs) in cardiovascular system disease. Whereas, the expression profiles and in-depth regulation of circRNAs on vascular smooth muscle cells (VSMCs) is still undetermined. In present study, our research team performed circRNAs microarray analysis to present the circRNAs expression profiles in high glucose induced VSMCs in vitro. Results showed that total of 983 circRNAs were discovered to be differentially expressed, and of these, 458 were upregulated and 525 were downregulated. Moreover, 31 circRNAs were up-regulated and 22 circRNAs were down-regulated with 2 fold change (P < 0.05). One of an up-regulated circRNA, circWDR77, was identified. In vitro cell assay, circWDR77 silencing significantly inhibited the proliferation and migration. Bioinformatics methods discovered that miR-124 and fibroblast growth factor 2 (FGF-2) were downstream targets of circWDR77. The RNA sequence complementary binding was validated by RNA immunoprecipitation (RIP) and/or luciferase reporter assay. Further function validation experiments revealed that circWDR77 regulated VSMCs proliferation and migration via targeting miR-124/FGF2. Taken together, present study firstly reveals the circRNAs expression profiles in high glucose induced VSMCs and identifies the role of circWDR77-miR-124-FGF2 regulatory pathway in VSMCs proliferation and migration, which might provide a new theoretical basis for diabetes mellitus correlated vasculopathy. Copyright © 2017 Elsevier Inc. All rights reserved.

Synthesis of the missing oxide of xenon, XeO2, and its implications for Earth's missing xenon.

PubMed

Brock, David S; Schrobilgen, Gary J

2011-04-27

The missing Xe(IV) oxide, XeO(2), has been synthesized at 0 °C by hydrolysis of XeF(4) in water and 2.00 M H(2)SO(4(aq)). Raman spectroscopy and (16/18)O isotopic enrichment studies indicate that XeO(2) possesses an extended structure in which Xe(IV) is oxygen bridged to four neighboring oxygen atoms to give a local square-planar XeO(4) geometry based on an AX(4)E(2) valence shell electron pair repulsion (VSEPR) arrangement. The vibrational spectra of Xe(16)O(2) and Xe(18)O(2) amend prior vibrational assignments of xenon doped SiO(2) and are in accordance with prior speculation that xenon depletion from the Earth's atmosphere may occur by xenon insertion at high temperatures and high pressures into SiO(2) in the Earth's crust.

Xenon Acquisition Strategies for High-Power Electric Propulsion NASA Missions

NASA Technical Reports Server (NTRS)

Herman, Daniel A.; Unfried, Kenneth G.

2015-01-01

Solar electric propulsion (SEP) has been used for station-keeping of geostationary communications satellites since the 1980s. Solar electric propulsion has also benefitted from success on NASA Science Missions such as Deep Space One and Dawn. The xenon propellant loads for these applications have been in the 100s of kilograms range. Recent studies performed for NASA's Human Exploration and Operations Mission Directorate (HEOMD) have demonstrated that SEP is critically enabling for both near-term and future exploration architectures. The high payoff for both human and science exploration missions and technology investment from NASA's Space Technology Mission Directorate (STMD) are providing the necessary convergence and impetus for a 30-kilowatt-class SEP mission. Multiple 30-50- kilowatt Solar Electric Propulsion Technology Demonstration Mission (SEP TDM) concepts have been developed based on the maturing electric propulsion and solar array technologies by STMD with recent efforts focusing on an Asteroid Redirect Robotic Mission (ARRM). Xenon is the optimal propellant for the existing state-of-the-art electric propulsion systems considering efficiency, storability, and contamination potential. NASA mission concepts developed and those proposed by contracted efforts for the 30-kilowatt-class demonstration have a range of xenon propellant loads from 100s of kilograms up to 10,000 kilograms. This paper examines the status of the xenon industry worldwide, including historical xenon supply and pricing. The paper will provide updated information on the xenon market relative to previous papers that discussed xenon production relative to NASA mission needs. The paper will discuss the various approaches for acquiring on the order of 10 metric tons of xenon propellant to support potential near-term NASA missions. Finally, the paper will discuss acquisitions strategies for larger NASA missions requiring 100s of metric tons of xenon will be discussed.

Removing krypton from xenon by cryogenic distillation to the ppq level

NASA Astrophysics Data System (ADS)

Aprile, E.; Aalbers, J.; Agostini, F.; Alfonsi, M.; Amaro, F. D.; Anthony, M.; Arneodo, F.; Barrow, P.; Baudis, L.; Bauermeister, B.; Benabderrahmane, M. L.; Berger, T.; Breur, P. A.; Brown, A.; Brown, E.; Bruenner, S.; Bruno, G.; Budnik, R.; Bütikofer, L.; Calvén, J.; Cardoso, J. M. R.; Cervantes, M.; Cichon, D.; Coderre, D.; Colijn, A. P.; Conrad, J.; Cussonneau, J. P.; Decowski, M. P.; de Perio, P.; Di Gangi, P.; Di Giovanni, A.; Diglio, S.; Duchovni, E.; Eurin, G.; Fei, J.; Ferella, A. D.; Fieguth, A.; Franco, D.; Fulgione, W.; Gallo Rosso, A.; Galloway, M.; Gao, F.; Garbini, M.; Geis, C.; Goetzke, L. W.; Grandi, L.; Greene, Z.; Grignon, C.; Hasterok, C.; Hogenbirk, E.; Huhmann, C.; Itay, R.; Kaminsky, B.; Kessler, G.; Kish, A.; Landsman, H.; Lang, R. F.; Lellouch, D.; Levinson, L.; Calloch, M. Le; Lin, Q.; Lindemann, S.; Lindner, M.; Lopes, J. A. M.; Manfredini, A.; Maris, I.; Undagoitia, T. Marrodán; Masbou, J.; Massoli, F. V.; Masson, D.; Mayani, D.; Meng, Y.; Messina, M.; Micheneau, K.; Miguez, B.; Molinario, A.; Murra, M.; Naganoma, J.; Ni, K.; Oberlack, U.; Orrigo, S. E. A.; Pakarha, P.; Pelssers, B.; Persiani, R.; Piastra, F.; Pienaar, J.; Piro, M.-C.; Pizzella, V.; Plante, G.; Priel, N.; Rauch, L.; Reichard, S.; Reuter, C.; Rizzo, A.; Rosendahl, S.; Rupp, N.; Saldanha, R.; Santos, J. M. F. dos; Sartorelli, G.; Scheibelhut, M.; Schindler, S.; Schreiner, J.; Schumann, M.; Lavina, L. Scotto; Selvi, M.; Shagin, P.; Shockley, E.; Silva, M.; Simgen, H.; Sivers, M. v.; Stein, A.; Thers, D.; Tiseni, A.; Trinchero, G.; Tunnell, C.; Upole, N.; Wang, H.; Wei, Y.; Weinheimer, C.; Wulf, J.; Ye, J.; Zhang, Y.; Cristescu, I.

2017-05-01

The XENON1T experiment aims for the direct detection of dark matter in a detector filled with 3.3 tons of liquid xenon. In order to achieve the desired sensitivity, the background induced by radioactive decays inside the detector has to be sufficiently low. One major contributor is the β -emitter ^{85}Kr which is present in the xenon. For XENON1T a concentration of natural krypton in xenon ^{nat}Kr/Xe < 200 ppq (parts per quadrillion, 1 ppq =10^{-15} mol/mol) is required. In this work, the design, construction and test of a novel cryogenic distillation column using the common McCabe-Thiele approach is described. The system demonstrated a krypton reduction factor of 6.4\\cdot 10^5 with thermodynamic stability at process speeds above 3 kg/h. The resulting concentration of ^{nat}Kr/Xe<26 ppq is the lowest ever achieved, almost one order of magnitude below the requirements for XENON1T and even sufficient for future dark matter experiments using liquid xenon, such as XENONnT and DARWIN.

Analgesic Effect of Xenon in Rat Model of Inflammatory Pain.

PubMed

Kukushkin, M L; Igon'kina, S I; Potapov, S V; Potapov, A V

2017-02-01

The analgesic effects of inert gas xenon were examined on rats. The formalin model of inflammatory pain, tail-flick test, and hot-plate test revealed the antinociceptive effects of subanesthetizing doses of inhalation anesthetic xenon. Inhalation of 50/50 xenon/oxygen mixture moderated the nociceptive responses during acute and tonic phases of inflammatory pain.

Critical Viscosity of Xenon team

NASA Technical Reports Server (NTRS)

2001-01-01

The Critical Viscosity of Xenon Experiment (CVX-2) on the STS-107 Research 1 mission in 2002 will measure the viscous behavior of xenon, a heavy inert gas used in flash lamps and ion rocket engines, at its critical point. The thermostat for CVX sits inside the white cylinder on a support structure (at left) that is placed inside a pressure canister. A similar canister (right) holds the electronics and control systems. The CVX-2 arrangement is identical. The principal investigator is Dr. Robert F. Berg (left) of the National Institutes of Standards and Technology, Gaithersburg, MD.

Critical Viscosity of Xenon team

NASA Technical Reports Server (NTRS)

2001-01-01

The Critical Viscosity of Xenon Experiment (CVX-2) on the STS-107 Research 1 mission in 2002 will measure the viscous behavior of xenon, a heavy inert gas used in flash lamps and ion rocket engines, at its critical point. The thermostat for CVX sits inside the white cylinder on a support structure (at left) that is placed inside a pressure canister. A similar canister (right) holds the electronics and control systems. The CVX-2 arrangement is identical. The principal investigator is Dr. Robert F. Berg (not shown) of the National Institutes of Standards and Technology, Gaithersburg, MD.

Hyperpolarized xenon-129 production and applications

NASA Astrophysics Data System (ADS)

Ruset, Iulian C.

Hyperpolarized 3He and 129Xe were initially developed and used in the nuclear physics community. Lately they are primarily used in Medical Resonance Imaging (MRI). Although first MRI polarized gas images were acquired using 129Xe, the research community has focused mostly on 3He, due to the well-known polarizing methods and higher polarization numbers achieved. The main purpose of this thesis is to present a novel design of a large-scale SEOP polarizer for producing large quantities of highly polarized 129Xe. High Rb-Xe spin-exchange rates through long-lived van de Waals molecules at low total pressure, implemented in a novel counterflow polarizer design, resulted in xenon polarization as high as 50% for 1.2 liters/hour, with a maximum of 64% for 0.3 l/h. We characterized and improved the polarization process by finding the optimum operating parameters of the polarizer. Two new methods to efficiently use high-power diode lasers are described: a new optical arrangement for a better beam shaping of fiber coupled lasers and the first external-cavity spectrum narrowing of a stack of laser diode arrays. A new accumulation technique for the hyperpolarized xenon was developed and full recovery of polarization after a freeze-thaw cycle was demonstrated for the first time. Two approaches for xenon delivery, frozen and gas states, were developed. Hyperpolarized xenon transportation to Brigham and Women's Hospital was successfully accomplished for collaborative research. First MRI images using hyperpolarized xenon acquired at BWH are presented. Final chapter is focused on describing a low field human MRI scanner using hyperpolarized 3He. We built a human scale imager with open access for orientational studies of the lung functionality. Horizontal and vertical human lung images were acquired as a first stage of this project.

Observation of a barium xenon exciplex within a large argon cluster.

PubMed

Briant, M; Gaveau, M-A; Mestdagh, J-M

2010-07-21

Spectroscopic measurements provide fluorescence and excitation spectra of a single barium atom codeposited with xenon atoms on argon clusters of average size approximately 2000. The spectra are studied as a function of the number of xenon atoms per cluster. The excitation spectrum with approximately 10 xenon atoms per cluster is qualitatively similar to that observed when no xenon atom is present on the cluster. It consists of two bands located on each side of the 6s6p (1)P-6s(2) (1)S resonance line of the free barium. In contrast, the fluorescence spectrum differs qualitatively since a barium-xenon exciplex is observed, which has no counterpart in xenon free clusters. In particular an emission is observed, which is redshifted by 729 cm(-1) with respect to the Ba(6s6p (1)P-6s(2) (1)S) resonance line.

Numerical study on xenon positive column discharges of mercury-free lamp

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

Ouyang, Jiting; He, Feng; Miao, Jinsong

2007-02-15

In this paper, the numerical study has been performed on the xenon positive column discharges of mercury-free fluorescent lamp. The plasma discharge characteristics are analyzed by numerical simulation based on two-dimensional fluid model. The effects of cell geometry, such as the dielectric layer, the electrode width, the electrode gap, and the cell height, and the filling gas including the pressure and the xenon percentage are investigated in terms of discharge current and discharge efficiency. The results show that a long transient positive column will form in the xenon lamp when applying ac sinusoidal power and the lamp can operate inmore » a large range of voltage and frequency. The front dielectric layer of the cell plays an important role in the xenon lamp while the back layer has little effect. The ratio of electrode gap to cell height should be large to achieve a long positive column xenon lamp and higher efficiency. Increase of pressure or xenon concentration results in an increase of discharge efficiency and voltage. The discussions will be helpful for the design of commercial xenon lamp cells.« less

The noble gas xenon provides protection and trophic stimulation to midbrain dopamine neurons.

PubMed

Lavaur, Jérémie; Le Nogue, Déborah; Lemaire, Marc; Pype, Jan; Farjot, Géraldine; Hirsch, Etienne C; Michel, Patrick P

2017-07-01

Despite its low chemical reactivity, the noble gas xenon possesses a remarkable spectrum of biological effects. In particular, xenon is a strong neuroprotectant in preclinical models of hypoxic-ischemic brain injury. In this study, we wished to determine whether xenon retained its neuroprotective potential in experimental settings that model the progressive loss of midbrain dopamine (DA) neurons in Parkinson's disease. Using rat midbrain cultures, we established that xenon was partially protective for DA neurons through either direct or indirect effects on these neurons. So, when DA neurons were exposed to l-trans-pyrrolidine-2,4-dicarboxylic acid so as to increase ambient glutamate levels and generate slow and sustained excitotoxicity, the effect of xenon on DA neurons was direct. The vitamin E analog Trolox also partially rescued DA neurons in this setting and enhanced neuroprotection by xenon. However, in the situation where DA cell death was spontaneous, the protection of DA neurons by xenon appeared indirect as it occurred through the repression of a mechanism mediated by proliferating glial cells, presumably astrocytes and their precursor cells. Xenon also exerted trophic effects for DA neurons in this paradigm. The effects of xenon were mimicked and improved by the N-methyl-d-aspartate glutamate receptor antagonist memantine and xenon itself appeared to work by antagonizing N-methyl-d-aspartate receptors. Note that another noble gas argon could not reproduce xenon effects. Overall, present data indicate that xenon can provide protection and trophic support to DA neurons that are vulnerable in Parkinson's disease. This suggests that xenon might have some therapeutic value for this disorder. © 2017 The Authors. Journal of Neurochemistry published by John Wiley & Sons Ltd on behalf of International Society for Neurochemistry.

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

Evaluation of pulmonary function using single-breath-hold dual-energy computed tomography with xenon

PubMed Central

Kyoyama, Hiroyuki; Hirata, Yusuke; Kikuchi, Satoshi; Sakai, Kosuke; Saito, Yuriko; Mikami, Shintaro; Moriyama, Gaku; Yanagita, Hisami; Watanabe, Wataru; Otani, Katharina; Honda, Norinari; Uematsu, Kazutsugu

2017-01-01

Abstract Xenon-enhanced dual-energy computed tomography (xenon-enhanced CT) can provide lung ventilation maps that may be useful for assessing structural and functional abnormalities of the lung. Xenon-enhanced CT has been performed using a multiple-breath-hold technique during xenon washout. We recently developed xenon-enhanced CT using a single-breath-hold technique to assess ventilation. We sought to evaluate whether xenon-enhanced CT using a single-breath-hold technique correlates with pulmonary function testing (PFT) results. Twenty-six patients, including 11 chronic obstructive pulmonary disease (COPD) patients, underwent xenon-enhanced CT and PFT. Three of the COPD patients underwent xenon-enhanced CT before and after bronchodilator treatment. Images from xenon-CT were obtained by dual-source CT during a breath-hold after a single vital-capacity inspiration of a xenon–oxygen gas mixture. Image postprocessing by 3-material decomposition generated conventional CT and xenon-enhanced images. Low-attenuation areas on xenon images matched low-attenuation areas on conventional CT in 21 cases but matched normal-attenuation areas in 5 cases. Volumes of Hounsfield unit (HU) histograms of xenon images correlated moderately and highly with vital capacity (VC) and total lung capacity (TLC), respectively (r = 0.68 and 0.85). Means and modes of histograms weakly correlated with VC (r = 0.39 and 0.38), moderately with forced expiratory volume in 1 second (FEV1) (r = 0.59 and 0.56), weakly with the ratio of FEV1 to FVC (r = 0.46 and 0.42), and moderately with the ratio of FEV1 to its predicted value (r = 0.64 and 0.60). Mode and volume of histograms increased in 2 COPD patients after the improvement of FEV1 with bronchodilators. Inhalation of xenon gas caused no adverse effects. Xenon-enhanced CT using a single-breath-hold technique depicted functional abnormalities not detectable on thin-slice CT. Mode, mean, and volume of HU histograms of xenon images

[Intracranial and cerebral perfusion pressure in neurosurgical patients during anaesthesia with xenon].

PubMed

Rylova, A V; Gavrilov, A G; Lubnin, A Iu; Potapov, A A

2014-01-01

Despite difficulties in providing xenon anaesthesia, xenon still seems to be attractive for neurosurgical procedures. But data upon its effect on intracranial (ICP) and cerebral perfusion pressure (CPP) remains controversial. We monitored ICP and CPP in patients with or without intracranial hypertension during xenon inhalation in different concentrations. Our results suggest that caution should be used while inhaling xenon in high anaesthetic concentration in patients wiith known intracranial hypertension. We also address new possibilities of xenon use, e.g., for sedation in neurosurgery. The study was supported by Russian Fund for Fundamental Research, grant number 13-04-01640.

Signal yields, energy resolution, and recombination fluctuations in liquid xenon

NASA Astrophysics Data System (ADS)

Akerib, D. S.; Alsum, S.; Araújo, H. M.; Bai, X.; Bailey, A. J.; Balajthy, J.; Beltrame, P.; Bernard, E. P.; Bernstein, A.; Biesiadzinski, T. P.; Boulton, E. M.; Bramante, R.; Brás, P.; Byram, D.; Cahn, S. B.; Carmona-Benitez, M. C.; Chan, C.; Chiller, A. A.; Chiller, C.; Currie, A.; Cutter, J. E.; Davison, T. J. R.; Dobi, A.; Dobson, J. E. Y.; Druszkiewicz, E.; Edwards, B. N.; Faham, C. H.; Fiorucci, S.; Gaitskell, R. J.; Gehman, V. M.; Ghag, C.; Gibson, K. R.; Gilchriese, M. G. D.; Hall, C. R.; Hanhardt, M.; Haselschwardt, S. J.; Hertel, S. A.; Hogan, D. P.; Horn, M.; Huang, D. Q.; Ignarra, C. M.; Ihm, M.; Jacobsen, R. G.; Ji, W.; Kamdin, K.; Kazkaz, K.; Khaitan, D.; Knoche, R.; Larsen, N. A.; Lee, C.; Lenardo, B. G.; Lesko, K. T.; Lindote, A.; Lopes, M. I.; Manalaysay, A.; Mannino, R. L.; Marzioni, M. F.; McKinsey, D. N.; Mei, D.-M.; Mock, J.; Moongweluwan, M.; Morad, J. A.; Murphy, A. St. J.; Nehrkorn, C.; Nelson, H. N.; Neves, F.; O'Sullivan, K.; Oliver-Mallory, K. C.; Palladino, K. J.; Pease, E. K.; Phelps, P.; Reichhart, L.; Rhyne, C.; Shaw, S.; Shutt, T. A.; Silva, C.; Solmaz, M.; Solovov, V. N.; Sorensen, P.; Stephenson, S.; Sumner, T. J.; Szydagis, M.; Taylor, D. J.; Taylor, W. C.; Tennyson, B. P.; Terman, P. A.; Tiedt, D. R.; To, W. H.; Tripathi, M.; Tvrznikova, L.; Uvarov, S.; Verbus, J. R.; Webb, R. C.; White, J. T.; Whitis, T. J.; Witherell, M. S.; Wolfs, F. L. H.; Xu, J.; Yazdani, K.; Young, S. K.; Zhang, C.; LUX Collaboration

2017-01-01

This work presents an analysis of monoenergetic electronic recoil peaks in the dark-matter-search and calibration data from the first underground science run of the Large Underground Xenon (LUX) detector. Liquid xenon charge and light yields for electronic recoil energies between 5.2 and 661.7 keV are measured, as well as the energy resolution for the LUX detector at those same energies. Additionally, there is an interpretation of existing measurements and descriptions of electron-ion recombination fluctuations in liquid xenon as limiting cases of a more general liquid xenon recombination fluctuation model. Measurements of the standard deviation of these fluctuations at monoenergetic electronic recoil peaks exhibit a linear dependence on the number of ions for energy deposits up to 661.7 keV, consistent with previous LUX measurements between 2 and 16 keV with 3H. We highlight similarities in liquid xenon recombination for electronic and nuclear recoils with a comparison of recombination fluctuations measured with low-energy calibration data.

Abatement of Xenon and Iodine Emissions from Medical Isotope Production Facilities

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

Doll, Charles G.; Sorensen, Christina M.; Bowyer, Ted W.

2014-04-01

The capability of the International Monitoring System (IMS) to detect xenon from underground nuclear explosions is dependent on the radioactive xenon background. Adding to the background, medical isotope production (MIP) by fission releases several important xenon isotopes including xenon-133 and iodine-133 that decays to xenon-133. The amount of xenon released from these facilities may be equivalent to or exceed that released from an underground nuclear explosion. Thus the release of gaseous fission products within days of irradiation makes it difficult to distinguish MIP emissions from a nuclear explosion. In addition, recent shortages in molybdenum-99 have created interest and investment opportunitiesmore » to design and build new MIP facilities in the United States and throughout the world. Due to the potential increase in the number of MIP facilities, a discussion of abatement technologies provides insight into how the problem of emission control from MIP facilities can be tackled. A review of practices is provided to delineate methods useful for abatement of medical isotopes.« less

Method of detecting leakage of reactor core components of liquid metal cooled fast reactors

DOEpatents

Holt, Fred E.; Cash, Robert J.; Schenter, Robert E.

1977-01-01

A method of detecting the failure of a sealed non-fueled core component of a liquid-metal cooled fast reactor having an inert cover gas. A gas mixture is incorporated in the component which includes Xenon-124; under neutron irradiation, Xenon-124 is converted to radioactive Xenon-125. The cover gas is scanned by a radiation detector. The occurrence of 188 Kev gamma radiation and/or other identifying gamma radiation-energy level indicates the presence of Xenon-125 and therefore leakage of a component. Similarly, Xe-126, which transmutes to Xe-127 and Kr-84, which produces Kr-85.sup.m can be used for detection of leakage. Different components are charged with mixtures including different ratios of isotopes other than Xenon-124. On detection of the identifying radiation, the cover gas is subjected to mass spectroscopic analysis to locate the leaking component.

Xenon International Automated Control

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

2016-08-05

The Xenon International Automated Control software monitors, displays status, and allows for manual operator control as well as fully automatic control of multiple commercial and PNNL designed hardware components to generate and transmit atmospheric radioxenon concentration measurements every six hours.

Terrestrial and Martian weathering signatures of xenon components in shergottite mineral separates

NASA Astrophysics Data System (ADS)

Cartwright, J. A.; Ocker, K. D.; Crowther, S. A.; Burgess, R.; Gilmour, J. D.

2010-08-01

Xenon-isotopic ratios, step-heating release patterns, and gas concentrations of mineral separates from Martian shergottites Roberts Massif (RBT) 04262, Dar al Gani (DaG) 489, Shergotty, and Elephant Moraine (EET) 79001 lithology B are reported. Concentrations of Martian atmospheric xenon are similar in mineral separates from all meteorites, but more weathered samples contain more terrestrial atmospheric xenon. The distributions of xenon from the Martian and terrestrial atmospheres among minerals in any one sample are similar, suggesting similarities in the processes by which they were acquired. However, in opaque and maskelynite fractions, Martian atmospheric xenon is released at higher temperatures than terrestrial atmospheric xenon. It is suggested that both Martian and terrestrial atmospheric xenon were initially introduced by weathering (low temperature alteration processes). However, the Martian component was redistributed by shock, accounting for its current residence in more retentive sites. The presence or absence of detectable 129Xe from the Martian atmosphere in mafic minerals may correspond to the extent of crustal contamination of the rock's parent melt. Variable contents of excess 129Xe contrast with previously reported consistent concentrations of excess 40Ar, suggesting distinct sources contributed these gases to the parent magma.

Signal yields, energy resolution, and recombination fluctuations in liquid xenon

DOE PAGES

Akerib, D. ?S.; Alsum, S.; Ara?jo, H. ?M.; ...

2017-01-19

This study presents an analysis of monoenergetic electronic recoil peaks in the dark-matter-search and calibration data from the first underground science run of the Large Underground Xenon (LUX) detector. Liquid xenon charge and light yields for electronic recoil energies between 5.2 and 661.7 keV are measured, as well as the energy resolution for the LUX detector at those same energies. Additionally, there is an interpretation of existing measurements and descriptions of electron-ion recombination fluctuations in liquid xenon as limiting cases of a more general liquid xenon recombination fluctuation model. Measurements of the standard deviation of these fluctuations at monoenergetic electronicmore » recoil peaks exhibit a linear dependence on the number of ions for energy deposits up to 661.7 keV, consistent with previous LUX measurements between 2 and 16 keV with 3H. We highlight similarities in liquid xenon recombination for electronic and nuclear recoils with a comparison of recombination fluctuations measured with low-energy calibration data.« less

Nicotine protects against DSS colitis through regulating microRNA-124 and STAT3.

PubMed

Qin, Zhen; Wan, Jing-Jing; Sun, Yang; Wu, Tingyu; Wang, Peng-Yuan; Du, Peng; Su, Ding-Feng; Yang, Yili; Liu, Xia

2017-02-01

Although it is generally believed that nicotine accounts for the beneficial effect of smoking on ulcerative colitis, the underlying mechanisms remain not well understood. Our previous finding that nicotine inhibits inflammatory responses through inducing miR-124 prompted us to ask whether the miRNA is involved in the protective action of nicotine against UC. Our present study found that miR-124 expression is upregulated in colon tissues from UC patients and DSS colitis mice. Nicotine treatment further augmented miR-124 expression in lymphocytes isolated from human ulcerative colonic mucosa and ulcerative colon tissues from DSS mice, both in infiltrated lymphocytes and epithelial cells. Moreover, knockdown of miR-124 significantly diminished the beneficial effect of nicotine on murine colitis and IL-6-treated Caco-2 colon epithelial cells. Further analysis indicated that nicotine inhibited STAT3 activation in vivo and in IL-6 treated Caco-2 cells and Jurkat human T lymphocytes, in which miR-124 knockdown led to increased activation of STAT3. Blocking STAT3 activity alone is beneficial for DSS colitis and also abolished nicotine's protective effect in this model. These data indicate that nicotine exerts its protective action in UC through inducing miR-124 and inhibiting STAT3, and suggest that the miR-124/STAT3 system is a potential target for the therapeutic intervention of UC. Nicotine upregulates miR-124 expression in ulcerative colon tissues and cells. MiR-124 is required for the protective role of nicotine in DSS colitis mice and epithelial cells. The protective effect of nicotine in murine DSS colitis depends on blocking STAT3 activation. MiR-124 mediates the inhibitory role of nicotine on STAT3/p-STAT3. Targeting miR-124 and STAT3 represents a novel approach for treating ulcerative colitis.

Xenon in the treatment of panic disorder: an open label study.

PubMed

Dobrovolsky, Alexander; Ichim, Thomas E; Ma, Daqing; Kesari, Santosh; Bogin, Vladimir

2017-06-13

Current treatments of panic disorder (PD) are limited by adverse effects, poor efficacy, and need for chronic administration. The established safety profile of subanesthetic concentrations of xenon gas, which is known to act as a glutamate subtype NMDA receptor antagonist, coupled with preclinical studies demonstrating its effects in other anxiety related conditions, prompted us to evaluate its feasibility and efficacy in treatment of patients with PD. An open-label clinical trial of xenon-oxygen mixture was conducted in 81 patients with PD; group 1 consisting of patients only with PD (N = 42); and group 2 patients with PD and other comorbidities (N = 39). Based on the analysis of the results of a number of psychometric scales used in this study (SAS, HADS, CGI), several conclusions can be made: (1) xenon is a potentially effective modality in acute treatment of PD; (2) an anti-panic effect of xenon administration persists for at least 6 months after the completion of the active phase of treatment; (3) xenon inhalation is well tolerated, with the drop-out rates being much lower than that of conventional pharmacotherapy (5.8% vs. 15%); (4) the severity of depressive disorders that frequently accompany PD can be significantly reduced with the use of xenon; (5) xenon may be considered as an alternative to benzodiazepines in conjunction with cognitive-behavioral therapy as a safe modality in treatment of anxiety disorder. These data support the need for randomized double-blind clinical trials to further study xenon-based interventions. Trial registration This clinical trial was retrospectively registered on April 14th, 2017 as ISRCTN15184285 in the ISRCTN database.

Density Functional Theory (DFT) Simulations of Shocked Liquid Xenon

NASA Astrophysics Data System (ADS)

Mattsson, Thomas R.; Magyar, Rudolph J.

2009-06-01

Xenon is not only a technologically important element used in laser technologies and jet propulsion, but it is also one of the most accessible materials in which to study the metal-insulator transition with increasing pressure. Because of its closed shell electronic configuration, Xenon is often assumed to be chemically inert, interacting almost entirely through the van der Waals interaction, and at liquid density, is typically modeled well using Leonard-Jones potentials. However, such modeling has a limited range of validity as Xenon is known to form compounds at normal conditions and likely exhibits considerably more chemistry at higher densities when hybridization of occupied orbitals becomes significant. In this talk, we present DFT-MD simulations of shocked liquid Xenon with the goal of developing an improved equation of state. Sandia is a multiprogram laboratory operated by Sandia Corporation, a Lockheed Martin Company, for the United States Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000.

NWA 8114: Analysis of Xenon in this Unique Martian Meteorite

NASA Astrophysics Data System (ADS)

Crowther, S. A.; Jastrzebski, N. D.; Nottingham, M.; Theis, K. J.; Gilmour, J. D.

2014-09-01

The Xe composition of NWA 8114 is dominated by martian atmospheric xenon, with contributions from terrestrial atmospheric contamination at low temperature and fissiogenic xenon at high temperature. The overall systematics are similar to Nakhla.

Dihydroartemisinin and Curcumin Synergistically Induce Apoptosis in SKOV3 Cells Via Upregulation of MiR-124 Targeting Midkine.

PubMed

Zhao, Jiaojiao; Pan, Yuchen; Li, Xiujun; Zhang, Xuefang; Xue, Yaxian; Wang, Tingting; Zhao, Shuli; Hou, Yayi

2017-01-01

Women with advanced ovarian carcinoma are less likely to receive platinum-based chemotherapy and surgery due to a greater risk of cytotoxicity and poorer outcomes. We attempted to improve a promising therapy against ovarian cancer by using a combination of dihydroartemisinin (DHA) and curcumin (Cur). Human ovarian cancer SKOV3 cells were treated with DHA, Cur alone, or a combination of both. The viability of SKOV3 cells was measured by Cell Counting Kit-8 (CCK-8) and a colony formation assay. The cell cycle and apoptosis of SKOV3 cells were monitored by flow cytometry. The mRNA and protein expression levels of target genes were respectively examined by qRT-PCR and western blot. The biological effects of miR-124 on midkine (MK) were verified by a luciferase activity analysis. Combined treatment of DHA and Cur synergistically decreased cell viability, arrested cell cycle, and promoted apoptosis in SKOV3 cells. Moreover, it significantly attenuated the expression of oncogene MK and synergistically upregulated the expression of miR-124. Furthermore, miR-124 was verified to bind directly to the 3'-untranslated region of MK mRNA, resulting in mRNA degradation and reduced MK protein levels. The combination of DHA with Cur significantly inhibited tumor growth in xenograft nude mice without obvious toxicity. Co-treatment with DHA and Cur exhibited a synergistic anti-tumor effect on SKOV3 cells both in vitro and in vivo. © 2017 The Author(s). Published by S. Karger AG, Basel.

A Decade of Xenon Chemistry

ERIC Educational Resources Information Center

Moody, G. J.

1974-01-01

Presents reactions for the formation of xenon compounds and compounds of the other inert gases. Provides bonding and structure theories for noble gas compounds and speculates on possible applications. (GS)

First Dark Matter Search Results from the XENON1T Experiment

NASA Astrophysics Data System (ADS)

Aprile, E.; Aalbers, J.; Agostini, F.; Alfonsi, M.; Amaro, F. D.; Anthony, M.; Arneodo, F.; Barrow, P.; Baudis, L.; Bauermeister, B.; Benabderrahmane, M. L.; Berger, T.; Breur, P. A.; Brown, A.; Brown, A.; Brown, E.; Bruenner, S.; Bruno, G.; Budnik, R.; Bütikofer, L.; Calvén, J.; Cardoso, J. M. R.; Cervantes, M.; Cichon, D.; Coderre, D.; Colijn, A. P.; Conrad, J.; Cussonneau, J. P.; Decowski, M. P.; de Perio, P.; di Gangi, P.; di Giovanni, A.; Diglio, S.; Eurin, G.; Fei, J.; Ferella, A. D.; Fieguth, A.; Fulgione, W.; Gallo Rosso, A.; Galloway, M.; Gao, F.; Garbini, M.; Gardner, R.; Geis, C.; Goetzke, L. W.; Grandi, L.; Greene, Z.; Grignon, C.; Hasterok, C.; Hogenbirk, E.; Howlett, J.; Itay, R.; Kaminsky, B.; Kazama, S.; Kessler, G.; Kish, A.; Landsman, H.; Lang, R. F.; Lellouch, D.; Levinson, L.; Lin, Q.; Lindemann, S.; Lindner, M.; Lombardi, F.; Lopes, J. A. M.; Manfredini, A.; Mariş, I.; Marrodán Undagoitia, T.; Masbou, J.; Massoli, F. V.; Masson, D.; Mayani, D.; Messina, M.; Micheneau, K.; Molinario, A.; Morâ, K.; Murra, M.; Naganoma, J.; Ni, K.; Oberlack, U.; Pakarha, P.; Pelssers, B.; Persiani, R.; Piastra, F.; Pienaar, J.; Pizzella, V.; Piro, M.-C.; Plante, G.; Priel, N.; Rauch, L.; Reichard, S.; Reuter, C.; Riedel, B.; Rizzo, A.; Rosendahl, S.; Rupp, N.; Saldanha, R.; Dos Santos, J. M. F.; Sartorelli, G.; Scheibelhut, M.; Schindler, S.; Schreiner, J.; Schumann, M.; Scotto Lavina, L.; Selvi, M.; Shagin, P.; Shockley, E.; Silva, M.; Simgen, H.; Sivers, M. V.; Stein, A.; Thapa, S.; Thers, D.; Tiseni, A.; Trinchero, G.; Tunnell, C.; Vargas, M.; Upole, N.; Wang, H.; Wang, Z.; Wei, Y.; Weinheimer, C.; Wulf, J.; Ye, J.; Zhang, Y.; Zhu, T.; Xenon Collaboration

2017-11-01

We report the first dark matter search results from XENON1T, a ˜2000 -kg -target-mass dual-phase (liquid-gas) xenon time projection chamber in operation at the Laboratori Nazionali del Gran Sasso in Italy and the first ton-scale detector of this kind. The blinded search used 34.2 live days of data acquired between November 2016 and January 2017. Inside the (1042 ±12 )-kg fiducial mass and in the [5 ,40 ] keVnr energy range of interest for weakly interacting massive particle (WIMP) dark matter searches, the electronic recoil background was (1.93 ±0.25 )×10-4 events /(kg ×day ×keVee) , the lowest ever achieved in such a dark matter detector. A profile likelihood analysis shows that the data are consistent with the background-only hypothesis. We derive the most stringent exclusion limits on the spin-independent WIMP-nucleon interaction cross section for WIMP masses above 10 GeV /c2 , with a minimum of 7.7 ×10-47 cm2 for 35 -GeV /c2 WIMPs at 90% C.L.

GraXe, graphene and xenon for neutrinoless double beta decay searches

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

Gómez-Cadenas, J.J.; Martín-Albo, J.; Monrabal, F.

2012-02-01

We propose a new detector concept, GraXe (to be pronounced as grace), to search for neutrinoless double beta decay in {sup 136}XE. GraXe combines a popular detection medium in rare-event searches, liquid xenon, with a new, background-free material, graphene. In our baseline design of GraXe, a sphere made of graphene-coated titanium mesh and filled with liquid xenon (LXe) enriched in the {sup 136}XE isotope is immersed in a large volume of natural LXe instrumented with photodetectors. Liquid xenon is an excellent scintillator, reasonably transparent to its own light. Graphene is transparent over a large frequency range, and impermeable to themore » xenon. Event position could be deduced from the light pattern detected in the photosensors. External backgrounds would be shielded by the buffer of natural LXe, leaving the ultra-radiopure internal volume virtually free of background. Industrial graphene can be manufactured at a competitive cost to produce the sphere. Enriching xenon in the isotope {sup 136}XE is easy and relatively cheap, and there is already near one ton of enriched xenon available in the world (currently being used by the EXO, KamLAND-Zen and NEXT experiments). All the cryogenic know-how is readily available from the numerous experiments using liquid xenon. An experiment using the GraXe concept appears realistic and affordable in a short time scale, and its physics potential is enormous.« less

Xenon as an Adjuvant to Propofol Anesthesia in Patients Undergoing Off-Pump Coronary Artery Bypass Graft Surgery: A Pragmatic Randomized Controlled Clinical Trial.

PubMed

Al Tmimi, Layth; Devroe, Sarah; Dewinter, Geertrui; Van de Velde, Marc; Poortmans, Gert; Meyns, Bart; Meuris, Bart; Coburn, Mark; Rex, Steffen

2017-10-01

Xenon was shown to cause less hemodynamic instability and reduce vasopressor needs during off-pump coronary artery bypass (OPCAB) surgery when compared with conventionally used anesthetics. As xenon exerts its organ protective properties even in subanesthetic concentrations, we hypothesized that in patients undergoing OPCAB surgery, 30% xenon added to general anesthesia with propofol results in superior hemodynamic stability when compared to anesthesia with propofol alone. Fifty patients undergoing elective OPCAB surgery were randomized to receive general anesthesia with 30% xenon adjuvant to a target-controlled infusion of propofol or with propofol alone. The primary end point was the total intraoperative dose of norepinephrine required to maintain an intraoperative mean arterial pressure >70 mm Hg. Secondary outcomes included the perioperative cardiorespiratory profile and the incidence of adverse and serious adverse events. Adding xenon to propofol anesthesia resulted in a significant reduction of norepinephrine required to attain the predefined hemodynamic goals (cumulative intraoperative dose: median [interquartile range]: 370 [116-570] vs 840 [335-1710] µg, P = .001). In the xenon-propofol group, significantly less propofol was required to obtain a similar depth of anesthesia as judged by clinical signs and the bispectral index (propofol effect site concentration [mean ± SD]: 1.8 ± 0.5 vs 2.8 ± 0.3 mg, P≤ .0001). Moreover, the xenon-propofol group required significantly less norepinephrine during the first 24 hours on the intensive care unit (median [interquartile range]: 1.5 [0.1-7] vs 5 [2-8] mg, P = .048). Other outcomes and safety parameters were similar in both groups. Thirty percent xenon added to propofol anesthesia improves hemodynamic stability by decreasing norepinephrine requirements in patients undergoing OPCAB surgery.

Collision-induced light scattering in a thin xenon layer between graphite slabs - MD study.

PubMed

Dawid, A; Górny, K; Wojcieszyk, D; Dendzik, Z; Gburski, Z

2014-08-14

The collision-induced light scattering many-body correlation functions and their spectra in thin xenon layer located between two parallel graphite slabs have been investigated by molecular dynamics computer simulations. The results have been obtained at three different distances (densities) between graphite slabs. Our simulations show the increased intensity of the interaction-induced light scattering spectra at low frequencies for xenon atoms in confined space, in comparison to the bulk xenon sample. Moreover, we show substantial dependence of the interaction-induced light scattering correlation functions of xenon on the distances between graphite slabs. The dynamics of xenon atoms in a confined space was also investigated by calculating the mean square displacement functions and related diffusion coefficients. The structural property of confined xenon layer was studied by calculating the density profile, perpendicular to the graphite slabs. Building of a fluid phase of xenon in the innermost part of the slot was observed. The nonlinear dependence of xenon diffusion coefficient on the separation distance between graphite slabs has been found. Copyright © 2014. Published by Elsevier B.V.

The noble gas xenon induces pharmacological preconditioning in the rat heart in vivo via induction of PKC-ɛ and p38 MAPK

PubMed Central

Weber, Nina C; Toma, Octavian; Wolter, Jessica I; Obal, Detlef; Müllenheim, Jost; Preckel, Benedikt; Schlack, Wolfgang

2004-01-01

Xenon is an anesthetic with minimal hemodynamic side effects, making it an ideal agent for cardiocompromised patients. We investigated if xenon induces pharmacological preconditioning (PC) of the rat heart and elucidated the underlying molecular mechanisms. For infarct size measurements, anesthetized rats were subjected to 25 min of coronary artery occlusion followed by 120 min of reperfusion. Rats received either the anesthetic gas xenon, the volatile anesthetic isoflurane or as positive control ischemic preconditioning (IPC) during three 5-min periods before 25-min ischemia. Control animals remained untreated for 45 min. To investigate the involvement of protein kinase C (PKC) and p38 mitogen-activated protein kinase (MAPK), rats were pretreated with the PKC inhibitor calphostin C (0.1 mg kg−1) or the p38 MAPK inhibitor SB203580 (1 mg kg−1). Additional hearts were excised for Western blot and immunohistochemistry. Infarct size was reduced from 50.9±16.7% in controls to 28.1±10.3% in xenon, 28.6±9.9% in isoflurane and to 28.5±5.4% in IPC hearts. Both, calphostin C and SB203580, abolished the observed cardioprotection after xenon and isoflurane administration but not after IPC. Immunofluorescence staining and Western blot assay revealed an increased phosphorylation and translocation of PKC-ɛ in xenon treated hearts. This effect could be blocked by calphostin C but not by SB203580. Moreover, the phosphorylation of p38 MAPK was induced by xenon and this effect was blocked by calphostin C. In summary, we demonstrate that xenon induces cardioprotection by PC and that activation of PKC-ɛ and its downstream target p38 MAPK are central molecular mechanisms involved. Thus, the results of the present study may contribute to elucidate the beneficial cardioprotective effects of this anesthetic gas. PMID:15644876

Reflectance of polytetrafluoroethylene for xenon scintillation light

NASA Astrophysics Data System (ADS)

Silva, C.; Pinto da Cunha, J.; Pereira, A.; Chepel, V.; Lopes, M. I.; Solovov, V.; Neves, F.

2010-03-01

Gaseous and liquid xenon particle detectors are being used in a number of applications including dark matter search and neutrino-less double beta decay experiments. Polytetrafluoroethylene (PTFE) is often used in these detectors both as electrical insulator and as a light reflector to improve the efficiency of detection of scintillation photons. However, xenon emits in the vacuum ultraviolet (VUV) wavelength region (λ ≃175 nm) where the reflecting properties of PTFE are not sufficiently known. In this work, we report on measurements of PTFE reflectance, including its angular distribution, for the xenon scintillation light. Various samples of PTFE, manufactured by different processes (extruded, expanded, skived, and pressed) have been studied. The data were interpreted with a physical model comprising both specular and diffuse reflections. The reflectance obtained for these samples ranges from about 47% to 66% for VUV light. Other fluoropolymers, namely, ethylene tetrafluoroethylene (ETFE), fluorinated ethylene propylene (FEP), and perfluoro-alkoxyalkane (PFA) were also measured.

Gravity assisted recovery of liquid xenon at large mass flow rates

NASA Astrophysics Data System (ADS)

Virone, L.; Acounis, S.; Beaupère, N.; Beney, J.-L.; Bert, J.; Bouvier, S.; Briend, P.; Butterworth, J.; Carlier, T.; Chérel, M.; Crespi, P.; Cussonneau, J.-P.; Diglio, S.; Manzano, L. Gallego; Giovagnoli, D.; Gossiaux, P.-B.; Kraeber-Bodéré, F.; Ray, P. Le; Lefèvre, F.; Marty, P.; Masbou, J.; Morteau, E.; Picard, G.; Roy, D.; Staempflin, M.; Stutzmann, J.-S.; Visvikis, D.; Xing, Y.; Zhu, Y.; Thers, D.

2018-06-01

We report on a liquid xenon gravity assisted recovery method for nuclear medical imaging applications. The experimental setup consists of an elevated detector enclosed in a cryostat connected to a storage tank called ReStoX. Both elements are part of XEMIS2 (XEnon Medical Imaging System): an innovative medical imaging facility for pre-clinical research that uses pure liquid xenon as detection medium. Tests based on liquid xenon transfer from the detector to ReStoX have been successfully performed showing that an unprecedented mass flow rate close to 1 ton per hour can be reached. This promising achievement as well as future areas of improvement will be discussed in this paper.

Liquid xenon purification, de-radonation (and de-kryptonation)

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

Pocar, Andrea, E-mail: pocar@umass.edu; Physics Division, Lawrence Livermore National Laboratory, Livermore, California 94550

Liquid xenon detectors are at the forefront of rare event physics, including searches for neutrino-less double beta decay and WIMP dark matter. The xenon for these experiments needs to be purified from chemical impurities such as electronegative atoms and molecules, which absorb ionization electrons, and VUV (178 nm) scintillation light-absorbing chemical species. In addition, superb purification from radioactive impurities is required. Particularly challenging are radioactive noble isotopes ({sup 85}Kr,{sup 39,42}Ar,{sup 220,222}Rn). Radon is a particularly universal problem, due to the extended decay sequence of its daughters and its ubiquitous presence in detector materials. Purification and de-radonation of liquid xenon aremore » addressed with particular focus on the experience gained with the EXO-200 neutrino-less double beta decay detector.« less

Circular RNA HIPK3 promotes gallbladder cancer cell growth by sponging microRNA-124.

PubMed

Kai, Ding; Yannian, Liao; Yitian, Chen; Dinghao, Gong; Xin, Zhao; Wu, Ji

2018-06-18

Recent studies have implied that circHIPK3, an abundant circular RNA (circRNA), participates in tumorigenesis and cancer progression. Its expression and potential functions in human gallbladder cancer were examined in this study. We show that circHIPK3 is upregulated in human gallbladder cancer cells. But its level is low in gallbladder epithelial cells. circHIPK3 silencing by targeted siRNA potently inhibited survival and proliferation of established and primary human gallbladder cancer cells, while inducing cell apoptosis. Conversely, ectopic over-expression of circHIPK3 can further promote cancer cell proliferation. In gallbladder cancer cells, circHIPK3 sponged the tumor-suppressive microRNA-124 (miR-124) to sequester and inhibit its activity, thereby leading to increased expression of miR-124 targets, including ROCK1 (rho-associated protein kinase 1) and CDK6 (rho-associated protein kinase). Ectopic over-expression of miR-124 b y a lentiviral vector mimicked and abolished actions by circHIPK3 siRNA in gallbladder cancer cells. At last, we show that circHIPK3 is upregulated in human gallbladder cancer tissues, which is correlated with miR-124 downregulation and ROCK1-CDK6 upregulation. Together, we conclude that circHIPK3 promotes gallbladder cancer cell growth possibly by sponging miR-124. The over-expressed circHIPK3 could be a novel therapeutic target and diagnosis marker of human gallbladder cancer. Copyright © 2018. Published by Elsevier Inc.

Mobility and fluorescence of barium ions in xenon gas for the exo experiment

NASA Astrophysics Data System (ADS)

Benitez Medina, Julio Cesar

The Enriched Xenon Observatory (EXO) is an experiment which aims to observe the neutrinoless double beta decay of 136Xe. The measurement of this decay would give information about the absolute neutrino mass and whether or not the neutrino is its own antiparticle. Since this is a very rare decay, the ability to reject background events by detecting the barium ion daughter from the double beta decay would be a major advantage. EXO is currently operating a detector with 200 kg of enriched liquid xenon, and there are plans to build a ton scale xenon detector. Measurements of the purity of liquid xenon in our liquid xenon test cell are reported. These results are relevant to the research on detection of single barium ions by our research group at Colorado State University. Details of the operation of the purity monitor are described. The effects of using a purifier, recirculation and laser ablation on the purity of liquid xenon are discussed. Mobility measurements of barium in xenon gas are reported for the first time. The variation of mobility with xenon gas pressure suggests that a significant fraction of molecular ions are formed when barium ions interact with xenon gas at high pressures. The measured mobility of Ba+ in Xe gas at different pressures is compared with the predicted theoretical value, and deviations are explained by a model that describes the fraction of molecular ions in Xe gas as a function of pressure. The results are useful for the analysis of experiments of fluorescence of Ba+ in xenon gas. It is also important to know the mobility of the ions in order to calculate the time they interact with an excitation laser in fluorescence experiments and in proposed 136 Ba+ daughter detection schemes. This thesis presents results of detection of laser induced fluorescence of Ba+ ions in Xe gas. Measurements of the pressure broadening of the excitation spectra of Ba+ in xenon gas are presented. Nonradiative decays due to gas collisions and optical pumping

The enzyme 3-hydroxykynurenine transaminase as potential target for 1,2,4-oxadiazoles with larvicide activity against the dengue vector Aedes aegypti.

PubMed

Oliveira, Vanessa S; Pimenteira, Cecília; da Silva-Alves, Diana C B; Leal, Laylla L L; Neves-Filho, Ricardo A W; Navarro, Daniela M A F; Santos, Geanne K N; Dutra, Kamilla A; dos Anjos, Janaína V; Soares, Thereza A

2013-11-15

The mosquito Aedes aegypti is the vector agent responsible for the transmission of yellow fever and dengue fever viruses to over 80 million people in tropical and subtropical regions of the world. Exhaustive efforts have lead to a vaccine candidate with only 30% effectiveness against the dengue virus and failure to protect patients against the serotype 2. Hence, vector control remains the most viable route to dengue fever control programs. We have synthesized a class of 1,2,4-oxadiazole derivatives whose most biologically active compounds exhibit potent activity against Aedes aegypti larvae (ca. of 15 ppm) and low toxicity in mammals. Exposure to these larvicides results in larvae pigmentation in a manner correlated with the LC50 measurements. Structural comparisons of the 1,2,4-oxadiazole nucleus against known inhibitors of insect enzymes allowed the identification of 3-hydroxykynurenine transaminase as a potential target for these synthetic larvicides. Molecular docking calculations indicate that 1,2,4-oxadiazole compounds can bind to 3-hydroxykynurenine transaminase with similar conformation and binding energies as its crystallographic inhibitor 4-(2-aminophenyl)-4-oxobutanoic acid. Copyright © 2013 Elsevier Ltd. All rights reserved.

Activation of PPARγ inhibits pro-inflammatory cytokines production by upregulation of miR-124 in vitro and in vivo

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

Wang, Dan; Shi, Liuyan; Xin, Wei

Peroxisome proliferator-activated receptor gamma (PPARγ) and miR-124 have been reported to play important roles in regulation of inflammation. However, the underlying anti-inflammatory mechanisms remain not well understood. In the present study, we demonstrated that the expression level of PPARγ is positively correlated with that of miR-124 in patients with sepsis. Activation of PPARγ upregulates miR-124 and in turn inhibits miR-124 target gene. PPARγ bound directly to PPRE in the miR-124 promoter region, and enhanced the promoter transcriptional activity. PPARγ-induced miR-124 is involved in the suppression of pro-inflammatory cytokine in vitro and in vivo. These results suggest that PPARγ-induced miR-124 inhibits the productionmore » of pro-inflammatory cytokines is a novel PPARγ anti-inflammatory mechanism and also indicate that miR-124 may be a potential therapeutic target for the treatment of inflammatory diseases. - Highlights: • The expression level of PPARγ is positively correlated with that of miR-124 in patients with sepsis. • PPARγ upregulates miR-124 and in turn inhibits miR-124 target gene. • PPARγ promotes miR-124 transcription through binding to miR-124 promoter region. • Inhibition of miR-124 attenuates the PPARγ-mediated suppression of proinflammatory cytokines in vitro. • PPARγ-induced miR-124 is involved in the suppression of pro-inflammatory cytokine in vivo.« less

PET-based compartmental modeling of (124)I-A33 antibody: quantitative characterization of patient-specific tumor targeting in colorectal cancer.

PubMed

Zanzonico, Pat; Carrasquillo, Jorge A; Pandit-Taskar, Neeta; O'Donoghue, Joseph A; Humm, John L; Smith-Jones, Peter; Ruan, Shutian; Divgi, Chaitanya; Scott, Andrew M; Kemeny, Nancy E; Fong, Yuman; Wong, Douglas; Scheinberg, David; Ritter, Gerd; Jungbluth, Achem; Old, Lloyd J; Larson, Steven M

2015-10-01

The molecular specificity of monoclonal antibodies (mAbs) directed against tumor antigens has proven effective for targeted therapy of human cancers, as shown by a growing list of successful antibody-based drug products. We describe a novel, nonlinear compartmental model using PET-derived data to determine the "best-fit" parameters and model-derived quantities for optimizing biodistribution of intravenously injected (124)I-labeled antitumor antibodies. As an example of this paradigm, quantitative image and kinetic analyses of anti-A33 humanized mAb (also known as "A33") were performed in 11 colorectal cancer patients. Serial whole-body PET scans of (124)I-labeled A33 and blood samples were acquired and the resulting tissue time-activity data for each patient were fit to a nonlinear compartmental model using the SAAM II computer code. Excellent agreement was observed between fitted and measured parameters of tumor uptake, "off-target" uptake in bowel mucosa, blood clearance, tumor antigen levels, and percent antigen occupancy. This approach should be generally applicable to antibody-antigen systems in human tumors for which the masses of antigen-expressing tumor and of normal tissues can be estimated and for which antibody kinetics can be measured with PET. Ultimately, based on each patient's resulting "best-fit" nonlinear model, a patient-specific optimum mAb dose (in micromoles, for example) may be derived.

The production of [124I]iodine and [86Y]yttrium.

PubMed

Schmitz, Jochen

2011-05-01

The use of paired tracers such as (124)I/(131)I and (86)Y/(90)Y allows pretherapy PET imaging with positron emitting radioisotopes of the same element as used for therapy. Whereas nowadays most therapy nuclides are produced by reactors or generators, the production of the corresponding PET isotopes requires the irradiation of adequate targets using particle accelerators such as cyclotrons. This paper describes the production routes for (124)I and (86)Y.

Density Functional Theory (dft) Simulations of Shocked Liquid Xenon

NASA Astrophysics Data System (ADS)

Mattsson, Thomas R.; Magyar, Rudolph J.

2009-12-01

Xenon is not only a technologically important element used in laser technologies and jet propulsion, but it is also one of the most accessible materials in which to study the metal-insulator transition with increasing pressure. Because of its closed shell electronic configuration, xenon is often assumed to be chemically inert, interacting almost entirely through the van der Waals interaction, and at liquid density, is typically modeled well using Leonard-Jones potentials. However, such modeling has a limited range of validity as xenon is known to form compounds under normal conditions and likely exhibits considerably more chemistry at higher densities when hybridization of occupied orbitals becomes significant. We present DFT-MD simulations of shocked liquid xenon with the goal of developing an improved equation of state. The calculated Hugoniot to 2 MPa compares well with available experimental shock data. Sandia is a mul-tiprogram laboratory operated by Sandia Corporation, a Lockheed Martin Company, for the United States Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000.

Experimental studies of a zeeman-tuned xenon laser differential absorption apparatus.

PubMed

Linford, G J

1973-06-01

A Zeeman-tuned cw xenon laser differential absorption device is described. The xenon laser was tuned by axial magnetic fields up to 5500 G generated by an unusually large water-cooled dc solenoid. Xenon laser lines at 3.37 micro, 3.51 micro, and 3.99 micro were tuned over ranges of 6 A, 6 A, and 11 A, respectively. To date, this apparatus has been used principally to study the details of formaldehyde absorption lines lying near the 3 .508-micro xenon laser transition. These experiments revealed that the observed absorption spectrum of formaldehyde exhibits a sufficiently unique spectral structure that the present technique may readily be used to measure relative concentrations of formaldehyde in samples of polluted air.

Gas chromatography/mass spectrometry measurement of xenon in gas-loaded liposomes for neuroprotective applications.

PubMed

Klegerman, Melvin E; Moody, Melanie R; Hurling, Jermaine R; Peng, Tao; Huang, Shao-Ling; McPherson, David D

2017-01-15

We have produced a liposomal formulation of xenon (Xe-ELIP) as a neuroprotectant for inhibition of brain damage in stroke patients. This mandates development of a reliable assay to measure the amount of dissolved xenon released from Xe-ELIP in water and blood samples. Gas chromatography/mass spectrometry (GC/MS) was used to quantify xenon gas released into the headspace of vials containing Xe-ELIP samples in water or blood. In order to determine blood concentration of xenon in vivo after Xe-ELIP administration, 6 mg of Xe-ELIP lipid was infused intravenously into rats. Blood samples were drawn directly from a catheterized right carotid artery. After introduction of the samples, each vial was allowed to equilibrate to 37°C in a water bath, followed by 20 minutes of sonication prior to headspace sampling. Xenon concentrations were calculated from a gas dose-response curve and normalized using the published xenon water-gas solubility coefficient. The mean corrected percent of xenon from Xe-ELIP released into water was 3.87 ± 0.56% (SD, n = 8), corresponding to 19.3 ± 2.8 μL/mg lipid, which is consistent with previous independent Xe-ELIP measurements. The corresponding xenon content of Xe-ELIP in rat blood was 23.38 ± 7.36 μL/mg lipid (n = 8). Mean rat blood xenon concentration after intravenous administration of Xe-ELIP was 14 ± 10 μM, which is approximately 15% of the estimated neuroprotective level. Using this approach, we have established a reproducible method for measuring dissolved xenon in fluids. These measurements have established that neuroprotective effects can be elicited by less than 20% of the calculated neuroprotective xenon blood concentration. More work will have to be done to establish the protective xenon pharmacokinetic range. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

[Effects of xenon anesthesia on cerebral blood flow in neurosurgical patients without intracranial hypertension].

PubMed

Rylova, A V; Beliaev, A Iu; Lubnin, A Iu

2013-01-01

Among anesthetic agents used in neurosurgery xenon appears to be the most advantageous. It preserves arterial blood pressure, assures rapid recovery and neuroprotection. But the data is lacking on xenon effect upon cerebral blood flow under anesthetic conditions. We measured flow velocity in middle cerebral artery in neurosurgical patients without intracranial hypertension during closed circuit xenon anesthesia comparing propofol and xenon effect in the same patients. In our study xenon didn't seem to induce clinically relevant changes in cerebral blood flow and preserved cerebral vascular reactivity thus proving its safety in patients without intracranial hypertension.

Modeling the Removal of Xenon from Lithium Hydrate with Aspen HYSYS

NASA Astrophysics Data System (ADS)

Efthimion, Phillip; Gentile, Charles

2011-10-01

The Laser Inertial Fusion Engine (LIFE) project mission is to provide a long-term, carbon-free source of sustainable energy, in the form of electricity. A conceptual xenon removal system has been modeled with the aid of Aspen HYSYS, a chemical process simulator. Aspen HYSYS provides excellent capability to model chemical flow processes, which generates outputs which includes specific variables such as temperature, pressure, and molar flow. The system is designed to strip out hydrogen isotopes deuterium and tritium. The base design bubbles plasma exhaust laden with x filled with liquid helium. The system separates the xenon from the hydrogen, deuterium, and tritium with a lithium hydrate and a lithium bubbler. After the removal of the hydrogen and its isotopes, the xenon is then purified by way of the process of cryogenic distillation. The pure hydrogen, deuterium, and tritium are then sent to the isotope separation system (ISS). The removal of xenon is an integral part of the laser inertial fusion engine and Aspen HYSYS is an excellent tool to calculate how to create pure xenon.

Xenon ventilation computed tomography and the management of asthma in the elderly.

PubMed

Park, Heung-Woo; Jung, Jae-Woo; Kim, Kyung-Mook; Kim, Tae-Wan; Lee, So-Hee; Lee, Chang Hyun; Goo, Jin Mo; Min, Kyung-Up; Cho, Sang-Heon

2014-04-01

Xenon ventilation computed tomography (CT) has shown potential in assessing the regional ventilation status in subjects with asthma. The purpose of this study was to evaluate the usefulness of xenon ventilation CT in the management of asthma in the elderly. Treatment-naïve asthmatics aged 65 years or older were recruited. Before initiation of medication, spirometry with bronchodilator (BD) reversibility, questionnaires to assess the severity of symptoms including a visual analogue scale (VAS), tests to evaluate cognitive function and mood, and xenon ventilation CT were performed. Xenon gas trapping (XT) on xenon ventilation CT represents an area where inhaled xenon gas was not expired and was trapped. Symptoms and lung functions were measured again after the 12-week treatment. A total of 30 elderly asthmatics were enrolled. The severity of dyspnoea measured by the VAS showed a significant correlation with the total number of areas of XT on the xenon ventilation CT taken in the pre-BD wash-out phase (r = -0.723, P < 0.001). The total number of areas of XT significantly decreased after BD inhalation, and differences in the total number of areas of XT (between the pre- and post-BD wash-out phases) at baseline showed significant correlations with the per cent increases in forced expiratory volume in 1 s after subsequent anti-asthma treatment (r = -0.775, P < 0.001). Xenon ventilation CT may be an objective and promising tool in the measurement of dyspnoea and prediction of the treatment response in elderly asthmatics. © 2014 The Authors. Respirology © 2014 Asian Pacific Society of Respirology.

[Characteristics of perioperative period in Xenon-based combined general anaesthesia in neurosurgery].

PubMed

Viatkin, A A; Petrosian, L G; Mizikov, V M; Vasil'ev, S A

2013-01-01

Neuroprotection could be the aim to use Xenon for general anesthesia. However the experience of Xenon anesthesia in neurosurgery is quite limited. The appraisal of Xenon based anesthesia was accomplished in 12 patients during various brain surgery. Xe in concentration 65% was used to maintenance of anesthesia, other medication was avoided. As a resuIt there were 8 cases of arterial hypertension and 2 cases of superficial hypnotic state. Excitation (n = 3), hyperdynamic reaction (n = 8), PONV (n = 8) were detected in early postoperative period. An analysis of this study suggests a conclusion that studied method of Xenon-based anesthesia is inexpedient for neurosurgery.

Xenon Defects in Uranium Dioxide From First Principles and Interatomic Potentials

NASA Astrophysics Data System (ADS)

Thompson, Alexander

In this thesis, we examine the defect energetics and migration energies of xenon atoms in uranium dioxide (UO2) from first principles and interatomic potentials. We also parameterize new, accurate interatomic potentials for xenon and uranium dioxide. To achieve accurate energetics and provide a foundation for subsequent calculations, we address difficulties in finding consistent energetics within Hubbard U corrected density functional theory (DFT+U). We propose a method of slowly ramping the U parameter in order to guide the calculation into low energy orbital occupations. We find that this method is successful for a variety of materials. We then examine the defect energetics of several noble gas atoms in UO2 for several different defect sites. We show that the energy to incorporate large noble gas atoms into interstitial sites is so large that it is energetically favorable for a Schottky defect cluster to be created to relieve the strain. We find that, thermodynamically, xenon will rarely ever be in the interstitial site of UO2. To study larger defects associated with the migration of xenon in UO 2, we turn to interatomic potentials. We benchmark several previously published potentials against DFT+U defect energetics and migration barriers. Using a combination of molecular dynamics and nudged elastic band calculations, we find a new, low energy migration pathway for xenon in UO2. We create a new potential for xenon that yields accurate defect energetics. We fit this new potential with a method we call Iterative Potential Refinement that parameterizes potentials to first principles data via a genetic algorithm. The potential finds accurate energetics for defects with relatively low amounts of strain (xenon in defect clusters). It is important to find accurate energetics for these sorts of low-strain defects because they essentially represent small xenon bubbles. Finally, we parameterize a new UO2 potential that simultaneously yields accurate vibrational properties

Xenon-Enhanced Dual-Energy CT Imaging in Combined Pulmonary Fibrosis and Emphysema

PubMed Central

Kobayashi, Masahiro; Nakamura, Yasuhiko; Gocho, Kyoko; Ishida, Fumiaki; Isobe, Kazutoshi; Shiraga, Nobuyuki; Homma, Sakae

2017-01-01

Background Little has been reported on the feasibility of xenon-enhanced dual-energy computed tomography (Xe-DECT) in the visual and quantitative analysis of combined pulmonary fibrosis and emphysema (CPFE). Objectives We compared CPFE with idiopathic pulmonary fibrosis (IPF) and chronic obstructive pulmonary disease (COPD), as well as correlation with parameters of pulmonary function tests (PFTs). Methods Studied in 3 groups were 25 patients with CPFE, 25 with IPF without emphysema (IPF alone), 30 with COPD. Xe-DECT of the patients’ entire thorax was taken from apex to base after a patient’s single deep inspiration of 35% stable nonradioactive xenon. The differences in several parameters of PFTs and percentage of areas enhanced by xenon between 3 groups were compared and analyzed retrospectively. Results The percentage of areas enhanced by xenon in both lungs were calculated as CPFE/IPF alone/COPD = 72.2 ± 15.1% / 82.2 ± 14.7% /45.2 ± 23.2%, respectively. In the entire patients, the percentage of areas enhanced by xenon showed significantly a positive correlation with FEV1/FVC (R = 0.558, P < 0.0001) and %FEV1, (R = 0.528, P < 0.0001) and a negative correlation with %RV (R = -0.594, P < 0.0001) and RV/TLC (R = -0.579, P < 0.0001). The percentage of areas enhanced by xenon in patients with CPFE showed significantly a negative correlation with RV/TLC (R = -0.529, P = 0.007). Xenon enhancement of CPFE indicated 3 different patterns such as upper predominant, diffuse, and multifocal defect. The percentage of areas enhanced by xenon in upper predominant defect pattern was significantly higher than that in diffuse defect and multifocal defect pattern among these 3 different patterns in CPFE. Conclusion The percentage of areas enhanced by xenon demonstrated strong correlations with obstructive ventilation impairment. Therefore, we conclude that Xe-DECT may be useful for distinguishing emphysema lesion from fibrotic lesion in CPFE. PMID:28107411

Xenon-Enhanced Dual-Energy CT Imaging in Combined Pulmonary Fibrosis and Emphysema.

PubMed

Sugino, Keishi; Kobayashi, Masahiro; Nakamura, Yasuhiko; Gocho, Kyoko; Ishida, Fumiaki; Isobe, Kazutoshi; Shiraga, Nobuyuki; Homma, Sakae

2017-01-01

Little has been reported on the feasibility of xenon-enhanced dual-energy computed tomography (Xe-DECT) in the visual and quantitative analysis of combined pulmonary fibrosis and emphysema (CPFE). We compared CPFE with idiopathic pulmonary fibrosis (IPF) and chronic obstructive pulmonary disease (COPD), as well as correlation with parameters of pulmonary function tests (PFTs). Studied in 3 groups were 25 patients with CPFE, 25 with IPF without emphysema (IPF alone), 30 with COPD. Xe-DECT of the patients' entire thorax was taken from apex to base after a patient's single deep inspiration of 35% stable nonradioactive xenon. The differences in several parameters of PFTs and percentage of areas enhanced by xenon between 3 groups were compared and analyzed retrospectively. The percentage of areas enhanced by xenon in both lungs were calculated as CPFE/IPF alone/COPD = 72.2 ± 15.1% / 82.2 ± 14.7% /45.2 ± 23.2%, respectively. In the entire patients, the percentage of areas enhanced by xenon showed significantly a positive correlation with FEV1/FVC (R = 0.558, P < 0.0001) and %FEV1, (R = 0.528, P < 0.0001) and a negative correlation with %RV (R = -0.594, P < 0.0001) and RV/TLC (R = -0.579, P < 0.0001). The percentage of areas enhanced by xenon in patients with CPFE showed significantly a negative correlation with RV/TLC (R = -0.529, P = 0.007). Xenon enhancement of CPFE indicated 3 different patterns such as upper predominant, diffuse, and multifocal defect. The percentage of areas enhanced by xenon in upper predominant defect pattern was significantly higher than that in diffuse defect and multifocal defect pattern among these 3 different patterns in CPFE. The percentage of areas enhanced by xenon demonstrated strong correlations with obstructive ventilation impairment. Therefore, we conclude that Xe-DECT may be useful for distinguishing emphysema lesion from fibrotic lesion in CPFE.

GAS CHROMATOGRAPHY-MASS SPECTROMETRY MEASUREMENT OF XENON IN GAS-LOADED LIPOSOMES FOR NEUROPROTECTIVE APPLICATIONS1

PubMed Central

Klegerman, Melvin E.; Moody, Melanie R.; Hurling, Jermaine R.; Peng, Tao; Huang, Shao-Ling; McPherson, David D.

2016-01-01

Rationale We have produced a liposomal formulation of xenon (Xe-ELIP) as a neuroprotectant for inhibition of brain damage in stroke patients. This mandates development of a reliable assay to measure the amount of dissolved xenon released from Xe-ELIP in water and blood samples. Methods Gas chromatography-Mass Spectrometry (GC-MS) was used to quantify xenon gas released into the headspace of vials containing Xe-ELIP samples in water or blood. In order to determine blood concentration of xenon in vivo after Xe-ELIP administration, 6 mg Xe-ELIP lipid was infused intravenously into rats. Blood samples were drawn directly from a catheterized right carotid artery. After introduction of the samples, each vial was allowed to equilibrate to 37° C in a water bath, followed by 20 minutes of sonication prior to headspace sampling. Xenon concentrations were calculated from a gas dose-response curve and normalized using the published xenon water-gas solubility coefficient. Results The mean corrected percent of xenon from Xe-ELIP released into water was 3.87 ± 0.56% (SD, n = 8), corresponding to 19.3 ± 2.8 μl/mg lipid, which is consistent with previous independent Xe-ELIP measurements. The corresponding xenon content of Xe-ELIP in rat blood was 23.38 ± 7.36 μl/mg lipid (n = 8). Mean rat blood xenon concentration after IV administration of Xe-ELIP was 14 ± 10 μM, which is approximately 15% of the estimated neuroprotective level. Conclusions Using this approach, we have established a reproducible method for measuring dissolved xenon in fluids. These measurements have established that neuroprotective effects can be elicited by less than 20% of the calculated neuroprotective xenon blood concentration. More work will have to be done to establish the protective xenon pharmacokinetic range. PMID:27689777

Xenon and hypothermia combine to provide neuroprotection from neonatal asphyxia.

PubMed

Ma, Daqing; Hossain, Mahmuda; Chow, Andre; Arshad, Mubarik; Battson, Renee M; Sanders, Robert D; Mehmet, Huseyin; Edwards, A David; Franks, Nicholas P; Maze, Mervyn

2005-08-01

Perinatal asphyxia can result in neuronal injury with long-term neurological and behavioral consequences. Although hypothermia may provide some modest benefit, the intervention itself can produce adverse consequences. We have investigated whether xenon, an antagonist of the N-methyl-D-aspartate subtype of the glutamate receptor, can enhance the neuroprotection provided by mild hypothermia. Cultured neurons injured by oxygen-glucose deprivation were protected by combinations of interventions of xenon and hypothermia that, when administered alone, were not efficacious. A combination of xenon and hypothermia administered 4 hours after hypoxic-ischemic injury in neonatal rats provided synergistic neuroprotection assessed by morphological criteria, by hemispheric weight, and by functional neurological studies up to 30 days after the injury. The protective mechanism of the combination, in both in vitro and in vivo models, involved an antiapoptotic action. If applied to humans, these data suggest that low (subanesthetic) concentrations of xenon in combination with mild hypothermia may provide a safe and effective therapy for perinatal asphyxia.

The Large Underground Xenon (LUX) experiment

DOE PAGES

Akerib, D. S.; Bai, X.; Bedikian, S.; ...

2012-11-29

The Large Underground Xenon (LUX) collaboration has designed and constructed a dual-phase xenon detector, in order to conduct a search for Weakly Interacting Massive Particles (WIMPs), a leading dark matter candidate. The goal of the LUX detector is to clearly detect (or exclude) WIMPS with a spin independent cross section per nucleon of 2×10 -46 cm 2, equivalent to ~1 event/100 kg/month in the inner 100-kg fiducial volume (FV) of the 370-kg detector. The overall background goals are set to have <1 background events characterized as possible WIMPs in the FV in 300 days of running. This work describes themore » design and construction of the LUX detector.« less

Optimization of Dual-Energy Xenon-CT for Quantitative Assessment of Regional Pulmonary Ventilation

PubMed Central

Fuld, Matthew K.; Halaweish, Ahmed; Newell, John D.; Krauss, Bernhard; Hoffman, Eric A.

2013-01-01

Objective Dual-energy X-ray computed tomography (DECT) offers visualization of the airways and quantitation of regional pulmonary ventilation using a single breath of inhaled xenon gas. In this study we seek to optimize scanning protocols for DECT xenon gas ventilation imaging of the airways and lung parenchyma and to characterize the quantitative nature of the developed protocols through a series of test-object and animal studies. Materials and Methods The Institutional Animal Care and Use Committee approved all animal studies reported here. A range of xenon-oxygen gas mixtures (0, 20, 25, 33, 50, 66, 100%; balance oxygen) were scanned in syringes and balloon test-objects to optimize the delivered gas mixture for assessment of regional ventilation while allowing for the development of improved three-material decomposition calibration parameters. Additionally, to alleviate gravitational effects on xenon gas distribution, we replaced a portion of the oxygen in the xenon/oxygen gas mixture with helium and compared gas distributions in a rapid-prototyped human central-airway test-object. Additional syringe tests were performed to determine if the introduction of helium had any effect on xenon quantitation. Xenon gas mixtures were delivered to anesthetized swine in order to assess airway and lung parenchymal opacification while evaluating various DECT scan acquisition settings. Results Attenuation curves for xenon were obtained from the syringe test objects and were used to develop improved three-material decomposition parameters (HU enhancement per percent xenon: Within the chest phantom: 2.25 at 80kVp, 1.7 at 100 kVp, and 0.76 at 140 kVp with tin filtration; In open air: 2.5 at 80kVp, 1.95 at 100 kVp, and 0.81 at 140 kVp with tin filtration). The addition of helium improved the distribution of xenon gas to the gravitationally non-dependent portion of the airway tree test-object, while not affecting quantitation of xenon in the three-material decomposition DECT. 40%Xe

The Long Noncoding RNA TP73-AS1 Interacted with miR-124 to Modulate Glioma Growth by Targeting Inhibitor of Apoptosis-Stimulating Protein of p53.

PubMed

Xiao, Shuai; Wang, Rensheng; Wu, Xiangwei; Liu, Wen; Ma, Shanshan

2018-02-01

P73 antisense RNA 1T (non-protein coding), known as TP73-AS1 or PDAM, is a long noncoding RNA (lncRNA), which may regulate apoptosis by regulation of p53-dependent antiapoptotic genes. An abnormal change of TP73-AS1 expression was noticed in cancers. The effects of TP73-AS1 in brain glioma growth and the underlying mechanism remain unclear so far. In this study, the effect of TP73-AS1 in human brain glioma cell lines and clinical tumor samples was detected so as to reveal its role and function. In this study, TP73-AS1 was specifically upregulated in brain glioma cell lines and promoted glioma cell growth through targeting miR-124. TP73-AS1 knocking down suppressed human brain glioma cell proliferation, invasion, and metastasis in vitro. The inhibitory effect of TP73-AS1 knocking down on glioma cell proliferation and invasion could partly be restored by miR-124 inhibition. In addition, miR-124-dependent inhibitor of apoptosis-stimulating protein of p53 (iASPP) regulation was required in TP73-AS1-induced brain glioma cell growth. Data from this study revealed that TP73-AS1 inhibited the brain glioma growth and metastasis as a competing endogenous RNA (ceRNA) through miR-124-dependent iASPP regulation. In conclusion, we regarded TP73-AS1 as an oncogenic lncRNA promoting brain glioma proliferation and metastasis and a potential target for human brain glioma treatment.

New insight into the assessment of asthma using xenon ventilation computed tomography.

PubMed

Jung, Jae-Woo; Kwon, Jae-Woo; Kim, Tae-Wan; Lee, So-Hee; Kim, Kyung-Mook; Kang, Hye-Ryun; Park, Heung-Woo; Lee, Chang-Hyun; Goo, Jin-Mo; Min, Kyung-Up; Cho, Sang-Heon

2013-08-01

Image analyses include computed tomography (CT), magnetic resonance imaging, and xenon ventilation CT, which is new modality to evaluate pulmonary functional imaging. To examine the usefulness of dual-energy xenon ventilation CT in asthmatic patients. A total of 43 patients 18 years or older who were nonsmokers were included in the study. Xenon CT images in wash-in and wash-out phases were obtained at baseline and after inhalation of methacholine and salbutamol. The degrees of ventilation defects and xenon trappings were evaluated through visual analysis. Ventilation defects and xenon trapping were significantly increased and decreased after methacholine challenge and salbutamol inhalation, respectively (P < .005). The ventilation abnormalities were not significantly related to the percentage of forced expiratory volume in 1 second (FEV1) or the ratio of FEV1 to forced vital capacity. Xenon trappings after salbutamol inhalation were negatively related to the scores of the asthma control test, wheezing, or night symptoms, with statistical significance (P < .05), whereas, FEV1 showed no significant correlation with symptom scores. Baseline FEV1 was significantly lower and dyspnea and wheezing were more severe in the non-full reversal group than in the full reversal group after salbutamol inhalation in xenon CT (P < .05). The degree of ventilation defects were positively correlated with FEV1 improvement after 3 months of treatment (P = .02). The results of this study suggest that xenon ventilation CT can be used as a new method to assess ventilation abnormalities in asthma, and these ventilation abnormalities can be used as novel parameters that reflect the status of asthma control and symptom severity. Copyright © 2013 American College of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.

A cCPE-based xenon biosensor for magnetic resonance imaging of claudin-expressing cells.

PubMed

Piontek, Anna; Witte, Christopher; May Rose, Honor; Eichner, Miriam; Protze, Jonas; Krause, Gerd; Piontek, Jörg; Schröder, Leif

2017-06-01

The majority of malignant tumors originate from epithelial cells, and many of them are characterized by an overexpression of claudins (Cldns) and their mislocalization out of tight junctions. We utilized the C-terminal claudin-binding domain of Clostridium perfringens enterotoxin (cCPE), with its high affinity to specific members of the claudin family, as the targeting unit for a claudin-sensitive cancer biosensor. To overcome the poor sensitivity of conventional relaxivity-based magnetic resonance imaging (MRI) contrast agents, we utilized the superior sensitivity of xenon Hyper-CEST biosensors. We labeled cCPE for both xenon MRI and fluorescence detection. As one readout module, we employed a cryptophane (CrA) monoacid and, as the second, a fluorescein molecule. Both were conjugated separately to a biotin molecule via a polyethyleneglycol chemical spacer and later via avidin linked to GST-cCPE. Nontransfected HEK293 cells and HEK293 cells stably expressing Cldn4-FLAG were incubated with the cCPE-based biosensor. Fluorescence-based flow cytometry and xenon MRI demonstrated binding of the biosensor specifically to Cldn4-expressing cells. This study provides proof of concept for the use of cCPE as a carrier for diagnostic contrast agents, a novel approach for potential detection of Cldn3/-4-overexpressing tumors for noninvasive early cancer detection. © 2017 New York Academy of Sciences.

First Dark Matter Search Results from the XENON1T Experiment.

PubMed

Aprile, E; Aalbers, J; Agostini, F; Alfonsi, M; Amaro, F D; Anthony, M; Arneodo, F; Barrow, P; Baudis, L; Bauermeister, B; Benabderrahmane, M L; Berger, T; Breur, P A; Brown, A; Brown, A; Brown, E; Bruenner, S; Bruno, G; Budnik, R; Bütikofer, L; Calvén, J; Cardoso, J M R; Cervantes, M; Cichon, D; Coderre, D; Colijn, A P; Conrad, J; Cussonneau, J P; Decowski, M P; de Perio, P; Di Gangi, P; Di Giovanni, A; Diglio, S; Eurin, G; Fei, J; Ferella, A D; Fieguth, A; Fulgione, W; Gallo Rosso, A; Galloway, M; Gao, F; Garbini, M; Gardner, R; Geis, C; Goetzke, L W; Grandi, L; Greene, Z; Grignon, C; Hasterok, C; Hogenbirk, E; Howlett, J; Itay, R; Kaminsky, B; Kazama, S; Kessler, G; Kish, A; Landsman, H; Lang, R F; Lellouch, D; Levinson, L; Lin, Q; Lindemann, S; Lindner, M; Lombardi, F; Lopes, J A M; Manfredini, A; Mariş, I; Marrodán Undagoitia, T; Masbou, J; Massoli, F V; Masson, D; Mayani, D; Messina, M; Micheneau, K; Molinario, A; Morå, K; Murra, M; Naganoma, J; Ni, K; Oberlack, U; Pakarha, P; Pelssers, B; Persiani, R; Piastra, F; Pienaar, J; Pizzella, V; Piro, M-C; Plante, G; Priel, N; Rauch, L; Reichard, S; Reuter, C; Riedel, B; Rizzo, A; Rosendahl, S; Rupp, N; Saldanha, R; Dos Santos, J M F; Sartorelli, G; Scheibelhut, M; Schindler, S; Schreiner, J; Schumann, M; Scotto Lavina, L; Selvi, M; Shagin, P; Shockley, E; Silva, M; Simgen, H; Sivers, M V; Stein, A; Thapa, S; Thers, D; Tiseni, A; Trinchero, G; Tunnell, C; Vargas, M; Upole, N; Wang, H; Wang, Z; Wei, Y; Weinheimer, C; Wulf, J; Ye, J; Zhang, Y; Zhu, T

2017-11-03

We report the first dark matter search results from XENON1T, a ∼2000-kg-target-mass dual-phase (liquid-gas) xenon time projection chamber in operation at the Laboratori Nazionali del Gran Sasso in Italy and the first ton-scale detector of this kind. The blinded search used 34.2 live days of data acquired between November 2016 and January 2017. Inside the (1042±12)-kg fiducial mass and in the [5,40]  keV_{nr} energy range of interest for weakly interacting massive particle (WIMP) dark matter searches, the electronic recoil background was (1.93±0.25)×10^{-4}  events/(kg×day×keV_{ee}), the lowest ever achieved in such a dark matter detector. A profile likelihood analysis shows that the data are consistent with the background-only hypothesis. We derive the most stringent exclusion limits on the spin-independent WIMP-nucleon interaction cross section for WIMP masses above 10  GeV/c^{2}, with a minimum of 7.7×10^{-47}  cm^{2} for 35-GeV/c^{2} WIMPs at 90% C.L.

Matched pairs dosimetry: 124I/131I metaiodobenzylguanidine and 124I/131I and 86Y/90Y antibodies.

PubMed

Lopci, Egesta; Chiti, Arturo; Castellani, Maria Rita; Pepe, Giovanna; Antunovic, Lidija; Fanti, Stefano; Bombardieri, Emilio

2011-05-01

The technological advances in imaging and production of radiopharmaceuticals are driving an innovative way of evaluating the targets for antineoplastic therapies. Besides the use of imaging to better delineate the volume of external beam radiation therapy in oncology, modern imaging techniques are able to identify targets for highly specific medical therapies, using chemotherapeutic drugs and antiangiogenesis molecules. Moreover, radionuclide imaging is able to select targets for radionuclide therapy and to give the way to in vivo dose calculation to target tissues and to critical organs. This contribution reports the main studies published on matched pairs dosimetry with (124)I/(131)I- and (86)Y/(90)Y-labelled radiopharmaceuticals, with an emphasis on metaiodobenzylguanidine (MIBG) and monoclonal antibodies.

Preclinical neuroprotective actions of xenon and possible implications for human therapeutics: a narrative review.

PubMed

Maze, Mervyn

2016-02-01

The purpose of this report is to facilitate an understanding of the possible application of xenon for neuroprotection in critical care settings. This narrative review appraises the literature assessing the efficacy and safety of xenon in preclinical models of acute ongoing neurologic injury. Databases of the published literature (MEDLINE® and EMBASE™) were appraised for peer-reviewed manuscripts addressing the use of xenon in both preclinical models and disease states of acute ongoing neurologic injury. For randomized clinical trials not yet reported, the investigators' declarations in the National Institutes of Health clinical trials website were considered. While not a primary focus of this review, to date, xenon cannot be distinguished as superior for surgical anesthesia over existing alternatives in adults. Nevertheless, studies in a variety of preclinical disease models from multiple laboratories have consistently shown xenon's neuroprotective properties. These properties are enhanced in settings where xenon is combined with hypothermia. Small randomized clinical trials are underway to explore xenon's efficacy and safety in clinical settings of acute neurologic injury where hypothermia is the current standard of care. According to the evidence to date, the neuroprotective efficacy of xenon in preclinical models and its safety in clinical anesthesia set the stage for the launch of randomized clinical trials to determine whether these encouraging neuroprotective findings can be translated into clinical utility.

In vivo detection of cucurbit[6]uril, a hyperpolarized xenon contrast agent for a xenon magnetic resonance imaging biosensor

PubMed Central

Hane, Francis T.; Li, Tao; Smylie, Peter; Pellizzari, Raiili M.; Plata, Jennifer A.; DeBoef, Brenton; Albert, Mitchell S.

2017-01-01

The Hyperpolarized gas Chemical Exchange Saturation Transfer (HyperCEST) Magnetic Resonance (MR) technique has the potential to increase the sensitivity of a hyperpolarized xenon-129 MRI contrast agent. Signal enhancement is accomplished by selectively depolarizing the xenon within a cage molecule which, upon exchange, reduces the signal in the dissolved phase pool. Herein we demonstrate the in vivo detection of the cucurbit[6]uril (CB6) contrast agent within the vasculature of a living rat. Our work may be used as a stepping stone towards using the HyperCEST technique as a molecular imaging modality. PMID:28106110

Comparison of xenon-based anaesthesia compared with total intravenous anaesthesia in high risk surgical patients.

PubMed

Bein, B; Turowski, P; Renner, J; Hanss, R; Steinfath, M; Scholz, J; Tonner, P H

2005-10-01

Xenon, a noble gas with anaesthetic and analgesic properties, has gained renewed interest due to its favourable physical properties which allow a rapid emergence from anaesthesia. However, high costs limit its use to a subset of patients who may benefit from xenon, thereby offsetting its costs. To date, there are only limited data available on the performance of xenon in high risk patients. We studied 39 patients with ASA physical status III undergoing aortic surgery. The patients were randomly assigned to either a xenon (Xe, n = 20) or a TIVA (T, n = 19) group. Global cardiac performance and myocardial contractility were assessed using transoesophageal echocardiography, and myocardial cell damage with troponin T and CK-MB. Echocardiographic measurements were made prior to xenon administration, following xenon administration, and after clamping of the abdominal aorta, after declamping and at corresponding time points in the TIVA group. Laboratory values were determined repeatedly for up to 72 h. Data were analysed using two-way anova factoring for time and anaesthetic agent or with ancova comparing linear regression lines. No significant differences were found in global myocardial performance, myocardial contractility or laboratory values at any time during the study period. Mean (SEM) duration of stay on the ICU (xenon: 38 +/- 46 vs. TIVA 25 +/- 15 h) or in hospital (xenon: 14 +/- 12 vs. TIVA 10 +/- 6 days) did not differ significantly between the groups. Although xenon has previously been shown to exert superior haemodynamic stability, we were unable to demonstrate an advantage of xenon-based anaesthesia compared to TIVA in high risk surgical patients.

Supernova Neutrino Physics with Xenon Dark Matter Detectors

NASA Astrophysics Data System (ADS)

Reichard, Shayne; Lang, Rafael F.; McCabe, Christopher; Selvi, Marco; Tamborra, Irene

2017-09-01

The dark matter experiment XENON1T is operational and sensitive to all flavors of neutrinos emitted from a supernova. We show that the proportional scintillation signal (S2) allows for a clear observation of the neutrino signal and guarantees a particularly low energy threshold, while the backgrounds are rendered negligible during the SN burst. XENON1T (XENONnT and LZ; DARWIN) will be sensitive to a SN burst up to 25 (40; 70) kpc from Earth at a significance of more than 5σ, observing approximately 35 (123; 704) events from a 27 M ⊙ SN progenitor at 10 kpc. Moreover, it will be possible to measure the average neutrino energy of all flavors, to constrain the total explosion energy, and to reconstruct the SN neutrino light curve. Our results suggest that a large xenon detector such as DARWIN will be competitive with dedicated neutrino telescopes, while providing complementary information that is not otherwise accessible.

Material radioassay and selection for the XENON1T dark matter experiment

NASA Astrophysics Data System (ADS)

Aprile, E.; Aalbers, J.; Agostini, F.; Alfonsi, M.; Amaro, F. D.; Anthony, M.; Arneodo, F.; Barrow, P.; Baudis, L.; Bauermeister, B.; Benabderrahmane, M. L.; Berger, T.; Breur, P. A.; Brown, A.; Brown, E.; Bruenner, S.; Bruno, G.; Budnik, R.; Bütikofer, L.; Calvén, J.; Cardoso, J. M. R.; Cervantes, M.; Cichon, D.; Coderre, D.; Colijn, A. P.; Conrad, J.; Cussonneau, J. P.; Decowski, M. P.; de Perio, P.; Di Gangi, P.; Di Giovanni, A.; Diglio, S.; Eurin, G.; Fei, J.; Ferella, A. D.; Fieguth, A.; Franco, D.; Fulgione, W.; Gallo Rosso, A.; Galloway, M.; Gao, F.; Garbini, M.; Geis, C.; Goetzke, L. W.; Grandi, L.; Greene, Z.; Grignon, C.; Hasterok, C.; Hogenbirk, E.; Itay, R.; Kaminsky, B.; Kessler, G.; Kish, A.; Landsman, H.; Lang, R. F.; Lellouch, D.; Levinson, L.; Le Calloch, M.; Lin, Q.; Lindemann, S.; Lindner, M.; Lopes, J. A. M.; Manfredini, A.; Maris, I.; Marrodán Undagoitia, T.; Masbou, J.; Massoli, F. V.; Masson, D.; Mayani, D.; Messina, M.; Micheneau, K.; Miguez, B.; Molinario, A.; Murra, M.; Naganoma, J.; Ni, K.; Oberlack, U.; Pakarha, P.; Pelssers, B.; Persiani, R.; Piastra, F.; Pienaar, J.; Piro, M.-C.; Pizzella, V.; Plante, G.; Priel, N.; Rauch, L.; Reichard, S.; Reuter, C.; Rizzo, A.; Rosendahl, S.; Rupp, N.; Saldanha, R.; dos Santos, J. M. F.; Sartorelli, G.; Scheibelhut, M.; Schindler, S.; Schreiner, J.; Schumann, M.; Scotto Lavina, L.; Selvi, M.; Shagin, P.; Shockley, E.; Silva, M.; Simgen, H.; Sivers, M. v.; Stein, A.; Thers, D.; Tiseni, A.; Trinchero, G.; Tunnell, C.; Upole, N.; Wang, H.; Wei, Y.; Weinheimer, C.; Wulf, J.; Ye, J.; Zhang, Y.; Laubenstein, M.; Nisi, S.

2017-12-01

The XENON1T dark matter experiment aims to detect weakly interacting massive particles (WIMPs) through low-energy interactions with xenon atoms. To detect such a rare event necessitates the use of radiopure materials to minimize the number of background events within the expected WIMP signal region. In this paper we report the results of an extensive material radioassay campaign for the XENON1T experiment. Using gamma-ray spectroscopy and mass spectrometry techniques, systematic measurements of trace radioactive impurities in over one hundred samples within a wide range of materials were performed. The measured activities allowed for stringent selection and placement of materials during the detector construction phase and provided the input for XENON1T detection sensitivity estimates through Monte Carlo simulations.

An improved interatomic potential for xenon in UO2: a combined density functional theory/genetic algorithm approach.

PubMed

Thompson, Alexander E; Meredig, Bryce; Wolverton, C

2014-03-12

We have created an improved xenon interatomic potential for use with existing UO2 potentials. This potential was fit to density functional theory calculations with the Hubbard U correction (DFT + U) using a genetic algorithm approach called iterative potential refinement (IPR). We examine the defect energetics of the IPR-fitted xenon interatomic potential as well as other, previously published xenon potentials. We compare these potentials to DFT + U derived energetics for a series of xenon defects in a variety of incorporation sites (large, intermediate, and small vacant sites). We find the existing xenon potentials overestimate the energy needed to add a xenon atom to a wide set of defect sites representing a range of incorporation sites, including failing to correctly rank the energetics of the small incorporation site defects (xenon in an interstitial and xenon in a uranium site neighboring uranium in an interstitial). These failures are due to problematic descriptions of Xe-O and/or Xe-U interactions of the previous xenon potentials. These failures are corrected by our newly created xenon potential: our IPR-generated potential gives good agreement with DFT + U calculations to which it was not fitted, such as xenon in an interstitial (small incorporation site) and xenon in a double Schottky defect cluster (large incorporation site). Finally, we note that IPR is very flexible and can be applied to a wide variety of potential forms and materials systems, including metals and EAM potentials.

Calculation of characteristics of compressed gaseous xenon gamma-ray detectors

NASA Astrophysics Data System (ADS)

Komarov, V. B.; Dmitrenko, V. V.; Ulin, S. E.; Uteshev, Z. M.

1992-12-01

Energy resolution and pulse distribution of a compressed gaseous xenon cylindrical detector were calculated. The analytical calculation took into account gamma-ray energy, fluctuation of electron-ion pairs, electron distribution, recombination, and H excess. The calculation was performed for a xenon density less than 0.6 g/cm and H excess less than 2 percent.

Early outgassing of Mars supported by differential water solubility of iodine and xenon

NASA Technical Reports Server (NTRS)

Musselwhite, Donald S.; Drake, Michael J.; Swindle, Timothy D.

1991-01-01

The Martian atmosphere has a high X-129/Xe-132 ratio compared to the Martian mantle. As Xe-129 is the daughter product of the extinct nuclide I-129, a means of fractionating iodine from xenon early in Martian history appears necessary to account for the X-129/Xe-132 ratios of its known reservoirs. A model is presented here to account for the Marian xenon data which relies on the very different solubilities of xenon and iodine in water to fractionate them after outgassing. Atmospheric xenon is lost by impact erosion during heavy bombardment, followed by release of Xe-129 produced from I-129 decay in the crust.

Discrimination Between Patients With Alzheimer Disease and Healthy Subjects Using Layer Analysis of Cerebral Blood Flow and Xenon Solubility Coefficient in Xenon-Enhanced Computed Tomography.

PubMed

Sase, Shigeru; Yamamoto, Homaro; Kawashima, Ena; Tan, Xin; Sawa, Yutaka

The aim of this study was to develop a method for discriminating between patients with Alzheimer disease (AD) and healthy subjects using layer analysis of cerebral blood flow (CBF) and xenon solubility coefficient (λ) in xenon-enhanced computed tomography (CT). Xenon-enhanced CT was performed on 27 patients with AD (81.7 [3.3] years old) and 15 healthy volunteers (78.6 [4.0] years old) using a wide volume CT. For each subject, we created the first- (surface) to sixth-layer images of CBF and λ for the 6 viewing directions (layer thickness, 5 mm). For the discriminant views, receiver operating characteristic curves for the ratio of CBF to λ were created to identify patients with AD. For the third- and fourth-layer left lateral views, which were designated as the discriminant views, areas under the receiver operating characteristic curve were 96.8% and 97.4%, respectively. With the use of the discriminant views obtained by xenon-enhanced CT, we could effectively discriminate between patients with AD and healthy subjects using both CBF and λ.

Noble Gas Xenon Is a Novel Adenosine Triphosphate-sensitive Potassium Channel Opener

PubMed Central

Bantel, Carsten; Maze, Mervyn; Trapp, Stefan

2010-01-01

Background Adenosine triphosphate-sensitive potassium (KATP) channels in brain are involved in neuroprotective mechanisms. Pharmacologic activation of these channels is seen as beneficial, but clinical exploitation by using classic K+ channel openers is hampered by their inability to cross the blood–brain barrier. This is different with the inhalational anesthetic xenon, which recently has been suggested to activate KATP channels; it partitions freely into the brain. Methods To evaluate the type and mechanism of interaction of xenon with neuronal-type KATP channels, these channels, consisting of Kir6.2 pore-forming subunits and sulfonylurea receptor-1 regulatory subunits, were expressed in HEK293 cells and whole cell, and excised patch-clamp recordings were performed. Results Xenon, in contrast to classic KATP channel openers, acted directly on the Kir6.2 subunit of the channel. It had no effect on the closely related, adenosine triphosphate (ATP)-regulated Kir1.1 channel and failed to activate an ATP-insensitive mutant version of Kir6.2. Furthermore, concentration–inhibition curves for ATP obtained from inside-out patches in the absence or presence of 80% xenon revealed that xenon reduced the sensitivity of the KATP channel to ATP. This was reflected in an approximately fourfold shift of the concentration causing half-maximal inhibition (IC50) from 26 ± 4 to 96 ± 6 μm. Conclusions Xenon represents a novel KATP channel opener that increases KATP currents independently of the sulfonylurea receptor-1 subunit by reducing ATP inhibition of the channel. Through this action and by its ability to readily partition across the blood–brain barrier, xenon has considerable potential in clinical settings of neuronal injury, including stroke. PMID:20179498

MicroRNA-124 expression counteracts pro-survival stress responses in glioblastoma.

PubMed

Mucaj, V; Lee, S S; Skuli, N; Giannoukos, D N; Qiu, B; Eisinger-Mathason, T S K; Nakazawa, M S; Shay, J E S; Gopal, P P; Venneti, S; Lal, P; Minn, A J; Simon, M C; Mathew, L K

2015-04-23

Glioblastomas are aggressive adult brain tumors, characterized by inadequately organized vasculature and consequent nutrient and oxygen (O2)-depleted areas. Adaptation to low nutrients and hypoxia supports glioblastoma cell survival, progression and therapeutic resistance. However, specific mechanisms promoting cellular survival under nutrient and O2 deprivation remain incompletely understood. Here, we show that miR-124 expression is negatively correlated with a hypoxic gene signature in glioblastoma patient samples, suggesting that low miR-124 levels contribute to pro-survival adaptive pathways in this disease. As miR-124 expression is repressed in various cancer types (including glioblastoma), we quantified miR-124 abundance in normoxic and hypoxic regions in glioblastoma patient tissue, and investigated whether ectopic miR-124 expression compromises cell survival during tumor ischemia. Our results indicate that miR-124 levels are further diminished in hypoxic/ischemic regions within individual glioblastoma patient samples, compared with regions replete in O2 and nutrients. Importantly, we also show that increased miR-124 expression affects the ability of tumor cells to survive under O2 and/or nutrient deprivation. Moreover, miR-124 re-expression increases cell death in vivo and enhances the survival of mice bearing intracranial xenograft tumors. miR-124 exerts this phenotype in part by directly regulating TEAD1, MAPK14/p38α and SERP1, factors involved in cell proliferation and survival under stress. Simultaneous suppression of these miR-124 targets results in similar levels of cell death as caused by miR-124 restoration. Importantly, we further demonstrate that SERP1 reintroduction reverses the hypoxic cell death elicited by miR-124, indicating the importance of SERP1 in promoting tumor cell survival. In support of our experimental data, we observed a significant correlation between high SERP1 levels and poor patient outcome in glioblastoma patients

MicroRNA-124 expression counteracts pro-survival stress responses in glioblastoma

PubMed Central

Mucaj, Vera; Lee, Samuel S.; Skuli, Nicolas; Giannoukos, Dionysios N.; Qiu, Bo; Eisinger-Mathason, T.S. Karin; Nakazawa, Michael S.; Shay, Jessica E.S.; Gopal, Pallavi P.; Venneti, Sriram; Lal, Priti; Minn, Andy J.; Simon, M. Celeste; Mathew, Lijoy K.

2014-01-01

Glioblastomas are aggressive adult brain tumors, characterized by inadequately organized vasculature and consequent nutrient and oxygen (O2)-depleted areas. Adaptation to low nutrients and hypoxia supports glioblastoma cell survival, progression, and therapeutic resistance. However, specific mechanisms promoting cellular survival under nutrient and O2 deprivation remain incompletely understood. Here, we show that miR-124 expression is negatively correlated with a hypoxic gene signature in glioblastoma patient samples, suggesting that low miR-124 levels contribute to pro-survival adaptive pathways in this disease. Since miR-124 expression is repressed in various cancers (including glioblastoma), we quantified miR-124 abundance in normoxic and hypoxic regions in glioblastoma patient tissue, and investigated whether ectopic miR-124 expression compromises cell survival, during tumor ischemia. Our results indicate that miR-124 levels are further diminished in hypoxic/ischemic regions within individual glioblastoma patient samples, compared to regions replete in O2 and nutrients. Importantly, we also show that increased miR-124 expression affects the ability of tumor cells to survive under O2 and/or nutrient deprivation. Moreover, miR-124 re-expression increases cell death in vivo, and enhances the survival of mice bearing intracranial xenograft tumors. miR-124 exerts this phenotype in part by directly regulating TEAD1, MAPK14/p38α and SERP1, factors involved in cell proliferation and survival under stress. Simultaneous suppression of these miR-124 targets results in similar levels of cell death as caused by miR-124 restoration. Importantly, we further demonstrate that SERP1 re-introduction reverses the hypoxic cell death elicited by miR-124, indicating the importance of SERP1 in promoting tumor cell survival. In support of our experimental data, we observed a significant correlation between high SERP1 levels and poor patient outcome in glioblastoma patients

Sub-anesthetic Xenon Increases Erythropoietin Levels in Humans: A Randomized Controlled Trial.

PubMed

Stoppe, Christian; Ney, Julia; Brenke, Martin; Goetzenich, Andreas; Emontzpohl, Christoph; Schälte, Gereon; Grottke, Oliver; Moeller, Manfred; Rossaint, Rolf; Coburn, Mark

2016-11-01

The licensed anesthetic xenon, which exerts organ protective properties, was recently added by the World Anti-Doping Agency to the list of prohibited substances. Xenon is supposed to trigger the production of hypoxia-inducible factor 1α (HIF-1α) and subsequently erythropoietin, but data are limited to in vivo experimental work. Therefore we evaluated the effect of xenon on erythropoietin levels in healthy persons. Twenty-four healthy volunteers were randomly assigned either to a group spontaneously breathing xenon 30 % (Xe/O 2 30 %/60 %) or a group breathing control gas (N 2 /O 2 40 %/60 %) for 45 min. Primary outcome parameters were erythropoietin levels at several time-points after exposure. Secondary outcome parameters were serum levels of testosterone, cytokines, and growth factors as well as concentrations of xenon in blood and exhalation samples measured at several time-points after exposure. In addition, hemodynamic safety parameters were monitored during exposure. The administration of xenon significantly increased erythropoietin levels 8 h after exposure (1.34 [±0.368]; p = 0.008), peaking at 24 h compared to the baseline values (1.45 [±0.498]; p = 0.01) and remained traceable in blood and exhalation probes until 24 h after exposure. In contrast, no significant change was observed in the control group. Measurement of stromal cell-derived factor 1 (SDF-1) revealed a significant increase of SDF-1 levels (p = 0.005), whereas no differences were observed with respect to growth factors, cytokines, or androgens. In an in vitro chemotaxis assay, endothelial progenitor cells (EPCs) showed a trend towards increased migration in serum samples received from participants after xenon exposure (p = 0.080). The present study presents first evidence about a xenon-induced effect on increased erythropoietin levels in healthy volunteers. The study was registered at the European Medicines Agency (EudraCT-number: 2014-000973-38) and at Clinical

Can xenon in water inhibit ice growth? Molecular dynamics of phase transitions in water-Xe system.

PubMed

Artyukhov, Vasilii I; Pulver, Alexander Yu; Peregudov, Alex; Artyuhov, Igor

2014-07-21

Motivated by recent experiments showing the promise of noble gases as cryoprotectants, we perform molecular dynamics modeling of phase transitions in water with xenon under cooling. We follow the structure and dynamics of xenon water solution as a function of temperature. Homogeneous nucleation of clathrate hydrate phase is observed and characterized. As the temperature is further reduced we observe hints of dissociation of clathrate due to stronger hydrophobic hydration, pointing towards a possible instability of clathrate at cryogenic temperatures and conversion to an amorphous phase comprised of "xenon + hydration shell" Xe·(H2O)21.5 clusters. Simulations of ice-xenon solution interface in equilibrium and during ice growth reveal the effects of xenon on the ice-liquid interface, where adsorbed xenon causes roughening of ice surface but does not preferentially form clathrate. These results provide evidence against the ice-blocker mechanism of xenon cryoprotection.

Xenon treatment attenuates early renal allograft injury associated with prolonged hypothermic storage in rats.

PubMed

Zhao, Hailin; Yoshida, Akira; Xiao, Wei; Ologunde, Rele; O'Dea, Kieran P; Takata, Masao; Tralau-Stewart, Catherine; George, Andrew J T; Ma, Daqing

2013-10-01

Prolonged hypothermic storage elicits severe ischemia-reperfusion injury (IRI) to renal grafts, contributing to delayed graft function (DGF) and episodes of acute immune rejection and shortened graft survival. Organoprotective strategies are therefore needed for improving long-term transplant outcome. The aim of this study is to investigate the renoprotective effect of xenon on early allograft injury associated with prolonged hypothermic storage. Xenon exposure enhanced the expression of heat-shock protein 70 (HSP-70) and heme oxygenase 1 (HO-1) and promoted cell survival after hypothermia-hypoxia insult in human proximal tubular (HK-2) cells, which was abolished by HSP-70 or HO-1 siRNA. In the brown Norway to Lewis rat renal transplantation, xenon administered to donor or recipient decreased the renal tubular cell death, inflammation, and MHC II expression, while delayed graft function (DGF) was therefore reduced. Pathological changes associated with acute rejection, including T-cell, macrophage, and fibroblast infiltration, were also decreased with xenon treatment. Donors or recipients treated with xenon in combination with cyclosporin A had prolonged renal allograft survival. Xenon protects allografts against delayed graft function, attenuates acute immune rejection, and enhances graft survival after prolonged hypothermic storage. Furthermore, xenon works additively with cyclosporin A to preserve post-transplant renal function.

[Effects of xenon preconditioning against ischemia/reperfusion injury and oxidative stress in immature heart].

PubMed

Li, Qian; Lian, Chun-Wei; Fang, Li-Qun; Liu, Bin; Yang, Bo

2014-09-01

To investigate whether xenon preconditioning (PC) could protect immature myocardium against ischemia-reperfusion (I/R) injury in a dose-dependent manner and clarify the role of xenon PC on oxidative stress. Forty-eight isolated perfused immature rabbit hearts were randomly divided into four groups (n = 12): The sham group had the hearts perfused continuously for 300 min. In I/R group, the hearts were subjected to 60 min perfusion followed by 60 min ischemia and 180 min reperfusion. In 1 minimum alveolar concentration (MAC) and 0.5 MAC xenon PC groups, the hearts were preconditioned with 1 MAC or 0.5 MAC xenon respectively, following 60 min ischemia and 180 min reperfusion. The cardiac function, myocardial infarct size, mitochondrial structure, superoxide dismutase (SOD) activity and malondialdehyde (MDA) level in each group were determined after reperfusion. Compared with I/R group, both 1 MAC and 0. 5 MAC xenon preconditioning significantly improved cardiac function (P < 0.01), reduced myocardial infarct size (P < 0.01) and mitochondrial damage, increased SOD activity and decreased MDA level (P < 0.01). There were no differences between 1 MAC group and 0.5 MAC xenon group (P > 0.05). Xenon preconditioning at 0. 5 and 1 MAC produce similar cardioprotective effects against I/R injury in isolated perfused immature heart.

Requirements for Xenon International

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

Hayes, James C.; Ely, James H.; Haas, Derek A.

2015-12-30

This document defines the requirements for the new Xenon International radioxenon system. The output of this project will be a Pacific Northwest National Laboratory (PNNL) developed prototype and a manufacturer-developed production prototype. The two prototypes are intended to be as close to matching as possible; this will be facilitated by overlapping development cycles and open communication between PNNL and the manufacturer.

Optimization of dual-energy xenon-computed tomography for quantitative assessment of regional pulmonary ventilation.

PubMed

Fuld, Matthew K; Halaweish, Ahmed F; Newell, John D; Krauss, Bernhard; Hoffman, Eric A

2013-09-01

Dual-energy x-ray computed tomography (DECT) offers visualization of the airways and quantitation of regional pulmonary ventilation using a single breath of inhaled xenon gas. In this study, we sought to optimize scanning protocols for DECT xenon gas ventilation imaging of the airways and lung parenchyma and to characterize the quantitative nature of the developed protocols through a series of test-object and animal studies. The Institutional Animal Care and Use Committee approved all animal studies reported here. A range of xenon/oxygen gas mixtures (0%, 20%, 25%, 33%, 50%, 66%, 100%; balance oxygen) were scanned in syringes and balloon test-objects to optimize the delivered gas mixture for assessment of regional ventilation while allowing for the development of improved 3-material decomposition calibration parameters. In addition, to alleviate gravitational effects on xenon gas distribution, we replaced a portion of the oxygen in the xenon/oxygen gas mixture with helium and compared gas distributions in a rapid-prototyped human central-airway test-object. Additional syringe tests were performed to determine if the introduction of helium had any effect on xenon quantitation. Xenon gas mixtures were delivered to anesthetized swine to assess airway and lung parenchymal opacification while evaluating various DECT scan acquisition settings. Attenuation curves for xenon were obtained from the syringe test-objects and were used to develop improved 3-material decomposition parameters (Hounsfield unit enhancement per percentage xenon: within the chest phantom, 2.25 at 80 kVp, 1.7 at 100 kVp, and 0.76 at 140 kVp with tin filtration; in open air, 2.5 at 80 kVp, 1.95 at 100 kVp, and 0.81 at 140 kVp with tin filtration). The addition of helium improved the distribution of xenon gas to the gravitationally nondependent portion of the airway tree test-object, while not affecting the quantitation of xenon in the 3-material decomposition DECT. The mixture 40% Xe/40% He/20% O2

Monitoring xenon purity in the LUX detector with a mass spectrometry system

NASA Astrophysics Data System (ADS)

Balajthy, Jon; LUX Experiment Collaboration

2015-04-01

The LUX dark matter search experiment is a 350 kg two-phase liquid/gas xenon time projection chamber located at the 4850 ft level of the Sanford Underground Research Facility in Lead, SD. To monitor for radioactive impurities such as krypton and impurities which limit charge yield such as oxygen, LUX uses a xenon sampling system consisting of a mass spectrometer and a liquid nitrogen cold trap. The cold trap separates the gaseous impurities from a small sample of xenon and allows them to pass to the mass spectrometer for analysis. We report here on results from the LUX xenon sampling program. We also report on methods to enhance the sensitivity of the cold trap technique in preparation for the next-generation LUX-ZEPLIN experiment which will have even more stringent purity requirements.

A technique for administering xenon gas anesthesia during surgical procedures in mice.

PubMed

Ruder, Arne Mathias; Schmidt, Michaela; Ludiro, Alessia; Riva, Marco A; Gass, Peter

2014-11-01

Carrying out invasive procedures in animals requires the administration of anesthesia. Xenon gas offers advantages as an anesthetic agent compared with other agents, such as its protection of the brain and heart from hypoxia-induced damage. The high cost of xenon gas has limited its use as an anesthetic in animal experiments, however. The authors designed and constructed simple boxes for the induction and maintenance of xenon gas and isoflurane anesthesia in small rodents in order to minimize the amount of xenon gas that is wasted. While using their anesthesia delivery system to anesthetize pregnant mice undergoing caesarean sections, they measured the respiratory rates of the anesthetized mice, the survival of the pups and the percentages of oxygen and carbon dioxide within the system to confirm the system's safety.

Molecular basis for the high-affinity binding and stabilization of firefly luciferase by PTC124

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

Auld, Douglas S.; Lovell, Scott; Thorne, Natasha

2010-04-07

Firefly luciferase (FLuc), an ATP-dependent bioluminescent reporter enzyme, is broadly used in chemical biology and drug discovery assays. PTC124 Ataluren; (3-[5-(2-fluorophenyl)-1,2,4-oxadiazol-3-yl]benzoic acid) discovered in an FLuc-based assay targeting nonsense codon suppression, is an unusually potent FLuc-inhibitor. Paradoxically, PTC124 and related analogs increase cellular FLuc activity levels by posttranslational stabilization. In this study, we show that FLuc inhibition and stabilization is the result of an inhibitory product formed during the FLuc-catalyzed reaction between its natural substrate, ATP, and PTC124. A 2.0 {angstrom} cocrystal structure revealed the inhibitor to be the acyl-AMP mixed-anhydride adduct PTC124-AMP, which was subsequently synthesized and shown tomore » be a high-affinity multisubstrate adduct inhibitor (MAI; KD = 120 pM) of FLuc. Biochemical assays, liquid chromatography/mass spectrometry, and near-attack conformer modeling demonstrate that formation of this novel MAI is absolutely dependent upon the precise positioning and reactivity of a key meta-carboxylate of PTC124 within the FLuc active site. We also demonstrate that the inhibitory activity of PTC124-AMP is relieved by free coenzyme A, a component present at high concentrations in luciferase detection reagents used for cell-based assays. This explains why PTC124 can appear to increase, instead of inhibit, FLuc activity in cell-based reporter gene assays. To our knowledge, this is an unusual example in which the 'off-target' effect of a small molecule is mediated by an MAI mechanism.« less

Irreversible xenon insertion into a small-pore zeolite at moderate pressures and temperatures

DOE PAGES

Seoung, Donghoon; Cynn, Hyunchae; Park, Changyong; ...

2014-09-01

Pressure drastically alters the chemical and physical properties of materials and allows structural phase transitions and chemical reactions to occur that defy much of our understanding gained under ambient conditions. Particularly exciting is the high-pressure chemistry of xenon, which is known to react with hydrogen and ice at high pressures and form stable compounds. Here, we show that Ag 16Al 16Si 24O 8·16H 2O (Ag-natrolite) irreversibly inserts xenon into its micropores at 1.7 GPa and 250 °C, while Ag + is reduced to metallic Ag and possibly oxidized to Ag 2+. In contrast to krypton, xenon is retained within themore » pores of this zeolite after pressure release and requires heat to desorb. This irreversible insertion and trapping of xenon in Ag-natrolite under moderate conditions sheds new light on chemical reactions that could account for the xenon deficiency relative to argon observed in terrestrial and Martian atmospheres.« less

Bispectral index, entropy, and quantitative electroencephalogram during single-agent xenon anesthesia.

PubMed

Laitio, Ruut M; Kaskinoro, Kimmo; Särkelä, Mika O K; Kaisti, Kaike K; Salmi, Elina; Maksimow, Anu; Långsjö, Jaakko W; Aantaa, Riku; Kangas, Katja; Jääskeläinen, Satu; Scheinin, Harry

2008-01-01

The aim was to evaluate the performance of anesthesia depth monitors, Bispectral Index (BIS) and Entropy, during single-agent xenon anesthesia in 17 healthy subjects. After mask induction with xenon and intubation, anesthesia was continued with xenon only. BIS, State Entropy and Response Entropy, and electroencephalogram were monitored throughout induction, steady-state anesthesia, and emergence. The performance of BIS, State Entropy, and Response Entropy were evaluated with prediction probability, sensitivity, and specificity analyses. The power spectrum of the raw electroencephalogram signal was calculated. The mean (SD) xenon concentration during anesthesia was 66.4% (2.4%). BIS, State Entropy, and Response Entropy demonstrated low prediction probability values at loss of response (0.455, 0.656, and 0.619) but 1 min after that the values were high (0.804, 0.941, and 0.929). Thereafter, equally good performance was demonstrated for all indices. At emergence, the prediction probability values to distinguish between steady-state anesthesia and return of response for BIS, State Entropy, and Response Entropy were 0.988, 0.892, and 0.992. No statistical differences between the performances of the monitors were observed. Quantitative electroencephalogram analyses showed generalized increase in total power (P < 0.001), delta (P < 0.001) and theta activity (P < 0.001), and increased alpha activity (P = 0.003) in the frontal brain regions. Electroencephalogram-derived depth of sedation indices BIS and Entropy showed a delay to detect loss of response during induction of xenon anesthesia. Both monitors performed well in distinguishing between conscious and unconscious states during steady-state anesthesia. Xenon-induced changes in electroencephalogram closely resemble those induced by propofol.

Neither xenon nor fentanyl induces neuroapoptosis in the newborn pig brain.

PubMed

Sabir, Hemmen; Bishop, Sarah; Cohen, Nicki; Maes, Elke; Liu, Xun; Dingley, John; Thoresen, Marianne

2013-08-01

Some inhalation anesthetics increase apoptotic cell death in the developing brain. Xenon, an inhalation anesthetic, increases neuroprotection when combined with therapeutic hypothermia after hypoxic-ischemic brain injury in newborn animals. The authors, therefore, examined whether there was any neuroapoptotic effect of breathing 50% xenon with continuous fentanyl sedation for 24 h at normothermia or hypothermia on newborn pigs. Twenty-six healthy pigs (<24-h old) were randomized into four groups: (1) 24  h of 50% inhaled xenon with fentanyl at hypothermia (Trec = 33.5 °C), (2) 24 h of 50% inhaled xenon with fentanyl at normothermia (Trec = 38.5 °C), (3) 24 h of fentanyl at normothermia, or (4) nonventilated juvenile controls at normothermia. Five additional nonrandomized pigs inhaled 2% isoflurane at normothermia for 24 h to verify any proapoptotic effect of inhalation anesthetics in our model. Pathological cells were morphologically assessed in cortex, putamen, hippocampus, thalamus, and white matter. To quantify the findings, immunostained cells (caspase-3 and terminal deoxynucleotidyl transferase-mediated deoxyuridine-triphosphate nick-end labeling) were counted in the same brain regions. For groups (1) to (4), the total number of apoptotic cells was less than 5 per brain region, representing normal developmental neuroapoptosis. After immunostaining and cell counting, regression analysis showed that neither 50% xenon with fentanyl nor fentanyl alone increased neuroapoptosis. Isoflurane caused on average a 5- to 10-fold increase of immunostained cells. At normothermia or hypothermia, neither 24 h of inhaled 50% xenon with fentanyl sedation nor fentanyl alone induces neuroapoptosis in the neonatal pig brain. Breathing 2% isoflurane increases neuroapoptosis in neonatal pigs.

Xenon depresses aEEG background voltage activity whilst maintaining cardiovascular stability in sedated healthy newborn pigs.

PubMed

Sabir, Hemmen; Wood, Thomas; Gill, Hannah; Liu, Xun; Dingley, John; Thoresen, Marianne

2016-04-15

Changes in electroencephalography (EEG) voltage range are used to monitor the depth of anaesthesia, as well as predict outcome after hypoxia-ischaemia in neonates. Xenon is being investigated as a potential neuroprotectant after hypoxic-ischaemic brain injury, but the effect of Xenon on EEG parameters in children or neonates is not known. This study aimed to examine the effect of 50% inhaled Xenon on background amplitude-integrated EEG (aEEG) activity in sedated healthy newborn pigs. Five healthy newborn pigs, receiving intravenous fentanyl sedation, were ventilated for 24 h with 50%Xenon, 30%O2 and 20%N2 at normothermia. The upper and lower voltage-range of the aEEG was continuously monitored together with cardiovascular parameters throughout a 1 h baseline period with fentanyl sedation only, followed by 24 h of Xenon administration. The median (IQR) upper and lower aEEG voltage during 1 h baseline was 48.0 μV (46.0-50.0) and 25.0 μV (23.0-26.0), respectively. The median (IQR) aEEG upper and lower voltage ranges were significantly depressed to 21.5 μV (20.0-26.5) and 12.0 μV (12.0-16.5) from 10 min after the onset of 50% Xenon administration (p=0.002). After the initial Xenon induced depression in background aEEG voltage, no further aEEG changes were seen over the following 24h of ventilation with 50% xenon under fentanyl sedation. Mean arterial blood pressure and heart rate remained stable. Mean arterial blood pressure and heart rate were not significantly influenced by 24h Xenon ventilation. 50% Xenon rapidly depresses background aEEG voltage to a steady ~50% lower level in sedated healthy newborn pigs. Therefore, care must be taken when interpreting the background voltage in neonates also receiving Xenon. Copyright © 2016 Elsevier B.V. All rights reserved.

Evaluation of pulmonary function using single-breath-hold dual-energy computed tomography with xenon: Results of a preliminary study.

PubMed

Kyoyama, Hiroyuki; Hirata, Yusuke; Kikuchi, Satoshi; Sakai, Kosuke; Saito, Yuriko; Mikami, Shintaro; Moriyama, Gaku; Yanagita, Hisami; Watanabe, Wataru; Otani, Katharina; Honda, Norinari; Uematsu, Kazutsugu

2017-01-01

Xenon-enhanced dual-energy computed tomography (xenon-enhanced CT) can provide lung ventilation maps that may be useful for assessing structural and functional abnormalities of the lung. Xenon-enhanced CT has been performed using a multiple-breath-hold technique during xenon washout. We recently developed xenon-enhanced CT using a single-breath-hold technique to assess ventilation. We sought to evaluate whether xenon-enhanced CT using a single-breath-hold technique correlates with pulmonary function testing (PFT) results.Twenty-six patients, including 11 chronic obstructive pulmonary disease (COPD) patients, underwent xenon-enhanced CT and PFT. Three of the COPD patients underwent xenon-enhanced CT before and after bronchodilator treatment. Images from xenon-CT were obtained by dual-source CT during a breath-hold after a single vital-capacity inspiration of a xenon-oxygen gas mixture. Image postprocessing by 3-material decomposition generated conventional CT and xenon-enhanced images.Low-attenuation areas on xenon images matched low-attenuation areas on conventional CT in 21 cases but matched normal-attenuation areas in 5 cases. Volumes of Hounsfield unit (HU) histograms of xenon images correlated moderately and highly with vital capacity (VC) and total lung capacity (TLC), respectively (r = 0.68 and 0.85). Means and modes of histograms weakly correlated with VC (r = 0.39 and 0.38), moderately with forced expiratory volume in 1 second (FEV1) (r = 0.59 and 0.56), weakly with the ratio of FEV1 to FVC (r = 0.46 and 0.42), and moderately with the ratio of FEV1 to its predicted value (r = 0.64 and 0.60). Mode and volume of histograms increased in 2 COPD patients after the improvement of FEV1 with bronchodilators. Inhalation of xenon gas caused no adverse effects.Xenon-enhanced CT using a single-breath-hold technique depicted functional abnormalities not detectable on thin-slice CT. Mode, mean, and volume of HU histograms of xenon images reflected

Development of a high-resolution liquid xenon detector for gamma-ray astrophysics

NASA Astrophysics Data System (ADS)

Mukherjee, Reshmi

It has been shown here that liquid xenon is one of the most promising detector media for future gamma-ray detectors, owing to an excellent combination of physical properties. The feasibility of the construction of a high resolution liquid xenon detector as a gamma-ray detector for astrophysics has been demonstrated. Up to 3.5 liters of liquid xenon has been successfully purified and using both small and large volume prototypes, the charge and the energy resolution response of such detectors to gamma-rays, internal conversion electrons and alpha particles have been measured. The best energy resolution measured was 4.5 percent FWHM at 1 MeV. Cosmic ray tracks have been imaged using a 2-dimensional liquid xenon multiwire imaging chamber. The spatial resolution along the direction of the drifting electrons was 180 microns rms. Experiments have been performed to study the scintillation light in liquid xenon, as the prompt scintillation signal in the liquid is an electron-ion pair in liquid krypton was measured for the first time with a pulsed ionization chamber to be 18.4 plus or minus 0.3 eV.

Scalability, Scintillation Readout and Charge Drift in a Kilogram Scale Solid Xenon Particle Detector

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

Yoo, J.; Cease, H.; Jaskierny, W. F.

2014-10-23

We report a demonstration of the scalability of optically transparent xenon in the solid phase for use as a particle detector above a kilogram scale. We employ a liquid nitrogen cooled cryostat combined with a xenon purification and chiller system to measure the scintillation light output and electron drift speed from both the solid and liquid phases of xenon. Scintillation light output from sealed radioactive sources is measured by a set of high quantum efficiency photomultiplier tubes suitable for cryogenic applications. We observed a reduced amount of photons in solid phase compared to that in liquid phase. We used amore » conventional time projection chamber system to measure the electron drift time in a kilogram of solid xenon and observed faster electron drift speed in the solid phase xenon compared to that in the liquid phase.« less

MiR-124 down-regulation is critical for cancer associated fibroblasts-enhanced tumor growth of oral carcinoma

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

Li, Xia, E-mail: dentistlx@163.com; Fan, Qinqiao; Li, Jinyun

Cancer associated fibroblasts (CAFs) are known to be involved in initiation, progression and metastasis of various cancers. However, the molecular mechanism of how CAFs affects the biological function of oral cancer (OC) has not been fully-addressed. In this study, we demonstrated that miR-124 was downregulated in oral CAFs and oral cancer cells (OCCs) when compared with matched normal fibroblasts (NFs). Hypermethylation in the promoter region of miR-124 genes was accounted for its downregulation. Interestingly, CAFs but not NFs exerted promotion effect on OCCs cell proliferation, migration and tumor growth in CAFs/NFs-OCCs co-culture. Furthermore, we identified Chemokine (C-C motif) ligand 2more » (CCL2) and Interleukin 8 (IL-8) as two direct targets of miR-124. Over-expression of miR-124 in CAFs-OCCs co-culture abrogated CAFs-promoted OCCs cell growth and migration, and this inhibitory effect can be rescued by addition of CCL2 and IL-8. Finally, we showed that restoration of miR-124 expression by lentiviral infection or formulated miR-124 injection inhibited oral tumor growth in vivo suggesting miR-124 rescue could be a potential rationale for therapeutic applications in oral cancer in the future. - Highlights: • miR-124 was downregulated in oral cancer cells and cancer associated fibroblasts. • Hypermethylation in the promoter region was accounted for miR-124 downregulation. • CCL2 and IL-8 are two direct targets of miR-124. • miR-124 rescue could be a potential rationale for oral cancer therapy.« less

Xenon improves neurological outcome and reduces secondary injury following trauma in an in vivo model of traumatic brain injury

PubMed Central

Luh, Clara; Gruss, Marco; Radyushkin, Konstantin; Hirnet, Tobias; Werner, Christian; Engelhard, Kristin; Franks, Nicholas P; Thal, Serge C; Dickinson, Robert

2015-01-01

Objectives To determine the neuroprotective efficacy of the inert gas xenon following traumatic brain injury, and to determine whether application of xenon has a clinically relevant therapeutic time window. Design Controlled animal study. Setting University research laboratory. Subjects Male C57BL/6N mice (n=196) Interventions 75% xenon, 50% xenon or 30% xenon, with 25% oxygen (balance nitrogen) treatment following mechanical brain lesion by controlled cortical impact. Measurements & Main Results Outcome following trauma was measured using: 1) functional neurological outcome score, 2) histological measurement of contusion volume, 3) analysis of locomotor function and gait. Our study shows that xenon-treatment improves outcome following traumatic brain injury. Neurological outcome scores were significantly (p<0.05) better in xenon-treated groups in the early phase (24 hours) and up to 4 days after injury. Contusion volume was significantly (p<0.05) reduced in the xenon-treated groups. Xenon treatment significantly (p<0.05) reduced contusion volume when xenon was given 15 minutes after injury or when treatment was delayed 1 hour or 3 hours after injury. Neurological outcome was significantly (p<0.05) improved when xenon treatment was given 15 minutes or 1 hour after injury. Improvements in locomotor function (p<0.05) were observed in the xenon-treated group, 1 month after trauma. Conclusions These results show for the first time that xenon improves neurological outcome and reduces contusion volume following traumatic brain injury in mice. In this model, xenon application has a therapeutic time window of up to at least 3 hours. These findings support the idea that xenon may be of benefit as a neuroprotective treatment in brain trauma patients. PMID:25188549

Xenon improves neurologic outcome and reduces secondary injury following trauma in an in vivo model of traumatic brain injury.

PubMed

Campos-Pires, Rita; Armstrong, Scott P; Sebastiani, Anne; Luh, Clara; Gruss, Marco; Radyushkin, Konstantin; Hirnet, Tobias; Werner, Christian; Engelhard, Kristin; Franks, Nicholas P; Thal, Serge C; Dickinson, Robert

2015-01-01

To determine the neuroprotective efficacy of the inert gas xenon following traumatic brain injury and to determine whether application of xenon has a clinically relevant therapeutic time window. Controlled animal study. University research laboratory. Male C57BL/6N mice (n = 196). Seventy-five percent xenon, 50% xenon, or 30% xenon, with 25% oxygen (balance nitrogen) treatment following mechanical brain lesion by controlled cortical impact. Outcome following trauma was measured using 1) functional neurologic outcome score, 2) histological measurement of contusion volume, and 3) analysis of locomotor function and gait. Our study shows that xenon treatment improves outcome following traumatic brain injury. Neurologic outcome scores were significantly (p < 0.05) better in xenon-treated groups in the early phase (24 hr) and up to 4 days after injury. Contusion volume was significantly (p < 0.05) reduced in the xenon-treated groups. Xenon treatment significantly (p < 0.05) reduced contusion volume when xenon was given 15 minutes after injury or when treatment was delayed 1 or 3 hours after injury. Neurologic outcome was significantly (p < 0.05) improved when xenon treatment was given 15 minutes or 1 hour after injury. Improvements in locomotor function (p < 0.05) were observed in the xenon-treated group, 1 month after trauma. These results show for the first time that xenon improves neurologic outcome and reduces contusion volume following traumatic brain injury in mice. In this model, xenon application has a therapeutic time window of up to at least 3 hours. These findings support the idea that xenon may be of benefit as a neuroprotective treatment in patients with brain trauma.

Online ^{222}Rn removal by cryogenic distillation in the XENON100 experiment

NASA Astrophysics Data System (ADS)

Aprile, E.; Aalbers, J.; Agostini, F.; Alfonsi, M.; Amaro, F. D.; Anthony, M.; Arneodo, F.; Barrow, P.; Baudis, L.; Bauermeister, B.; Benabderrahmane, M. L.; Berger, T.; Breur, P. A.; Brown, A.; Brown, E.; Bruenner, S.; Bruno, G.; Budnik, R.; Bütikofer, L.; Calvén, J.; Cardoso, J. M. R.; Cervantes, M.; Cichon, D.; Coderre, D.; Colijn, A. P.; Conrad, J.; Cussonneau, J. P.; Decowski, M. P.; de Perio, P.; Gangi, P. Di; Giovanni, A. Di; Diglio, S.; Duchovni, E.; Eurin, G.; Fei, J.; Ferella, A. D.; Fieguth, A.; Franco, D.; Fulgione, W.; Gallo Rosso, A.; Galloway, M.; Gao, F.; Garbini, M.; Geis, C.; Goetzke, L. W.; Grandi, L.; Greene, Z.; Grignon, C.; Hasterok, C.; Hogenbirk, E.; Itay, R.; Kaminsky, B.; Kessler, G.; Kish, A.; Landsman, H.; Lang, R. F.; Lellouch, D.; Levinson, L.; Calloch, M. Le; Lin, Q.; Lindemann, S.; Lindner, M.; Lopes, J. A. M.; Manfredini, A.; Maris, I.; Undagoitia, T. Marrodán; Masbou, J.; Massoli, F. V.; Masson, D.; Mayani, D.; Meng, Y.; Messina, M.; Micheneau, K.; Miguez, B.; Molinario, A.; Murra, M.; Naganoma, J.; Ni, K.; Oberlack, U.; Orrigo, S. E. A.; Pakarha, P.; Pelssers, B.; Persiani, R.; Piastra, F.; Pienaar, J.; Piro, M.-C.; Pizzella, V.; Plante, G.; Priel, N.; Rauch, L.; Reichard, S.; Reuter, C.; Rizzo, A.; Rosendahl, S.; Rupp, N.; Saldanha, R.; dos Santos, J. M. F.; Sartorelli, G.; Scheibelhut, M.; Schindler, S.; Schreiner, J.; Schumann, M.; Lavina, L. Scotto; Selvi, M.; Shagin, P.; Shockley, E.; Silva, M.; Simgen, H.; Sivers, M. v.; Stein, A.; Thers, D.; Tiseni, A.; Trinchero, G.; Tunnell, C.; Upole, N.; Wang, H.; Wei, Y.; Weinheimer, C.; Wulf, J.; Ye, J.; Zhang, Y.; Cristescu, I.

2017-06-01

We describe the purification of xenon from traces of the radioactive noble gas radon using a cryogenic distillation column. The distillation column was integrated into the gas purification loop of the XENON100 detector for online radon removal. This enabled us to significantly reduce the constant ^{222}Rn background originating from radon emanation. After inserting an auxiliary ^{222}Rn emanation source in the gas loop, we determined a radon reduction factor of R > 27 (95% C.L.) for the distillation column by monitoring the ^{222}Rn activity concentration inside the XENON100 detector.

MicroRNA-124 regulates the expression of MEKK3 in the inflammatory pathogenesis of Parkinson's disease.

PubMed

Yao, Longping; Ye, Yongyi; Mao, Hengxu; Lu, Fengfei; He, Xiaozheng; Lu, Guohui; Zhang, Shizhong

2018-01-12

Parkinson's disease (PD) is the most prevalent neurodegenerative disorder that is characterised by selective loss of midbrain dopaminergic (DA) neurons. Chronic inflammation of the central nervous system is mediated by microglial cells and plays a critical role in the pathological progression of PD. Brain-specific microRNA-124 (miR-124) expression is significantly downregulated in lipopolysaccharide (LPS)-treated BV2 cells and in the 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) model of PD. However, whether abnormal miR-124 expression could regulate the activation of microglia remains poorly understood. BV2 cells were activated by exposure to LPS, and the expression levels of miR-124, mitogen-activated protein kinase kinase kinase 3 (MEKK3), and the nuclear factor of kappaB (NF-κB) p-p65 were analysed. Over-expression and knockdown studies of miR-124 were performed to observe the effects on MEKK3/NF-κB signalling pathways, and the induction of pro-inflammatory and neurotoxic factors was assessed. In addition, a luciferase reporter assay was conducted to confirm whether MEKK3 is a direct target of miR-124. Meanwhile, production of miR-124, MEKK3, and p-p65; midbrain DA neuronal death; or activation of microglia were analysed when treated with or without miR-124 in the MPTP-induced model of PD. We found that the knockdown of MEKK3 could inhibit the activation of microglia by regulating NF-κB expression. Over-expression of miR-124 could effectively attenuate the LPS-induced expression of pro-inflammatory cytokines and promote the secretion of neuroprotective factors. We also first identified a unique role of miR-124 in mediating the microglial inflammatory response by targeting MEKK3/NF-κB signalling pathways. In the microglial culture supernatant (MCS) transfer model, over-expression of the miR-124 or knockdown of MEKK3 in BV2 cells prevented SH-SY5Y from apoptosis and death. Moreover, MEKK3 and p-p65 were abundantly expressed in the midbrain. Furthermore

Inference and analysis of xenon outflow curves under multi-pulse injection in two-dimensional chromatography.

PubMed

Shu-Jiang, Liu; Zhan-Ying, Chen; Yin-Zhong, Chang; Shi-Lian, Wang; Qi, Li; Yuan-Qing, Fan

2013-10-11

Multidimensional gas chromatography is widely applied to atmospheric xenon monitoring for the Comprehensive Nuclear-Test-Ban Treaty (CTBT). To improve the capability for xenon sampling from the atmosphere, sampling techniques have been investigated in detail. The sampling techniques are designed by xenon outflow curves which are influenced by many factors, and the injecting condition is one of the key factors that could influence the xenon outflow curves. In this paper, the xenon outflow curves of single-pulse injection in two-dimensional gas chromatography has been tested and fitted as a function of exponential modified Gaussian distribution. An inference formula of the xenon outflow curve for six-pulse injection is derived, and the inference formula is also tested to compare with its fitting formula of the xenon outflow curve. As a result, the curves of both the one-pulse and six-pulse injections obey the exponential modified Gaussian distribution when the temperature of the activated carbon column's temperature is 26°C and the flow rate of the carrier gas is 35.6mLmin(-1). The retention time of the xenon peak for one-pulse injection is 215min, and the peak width is 138min. For the six-pulse injection, however, the retention time is delayed to 255min, and the peak width broadens to 222min. According to the inferred formula of the xenon outflow curve for the six-pulse injection, the inferred retention time is 243min, the relative deviation of the retention time is 4.7%, and the inferred peak width is 225min, with a relative deviation of 1.3%. Copyright © 2013 Elsevier B.V. All rights reserved.

Early treatment with xenon protects against the cold ischemia associated with chronic allograft nephropathy in rats.

PubMed

Zhao, Hailin; Luo, Xianghong; Zhou, Zhaowei; Liu, Juying; Tralau-Stewart, Catherine; George, Andrew J T; Ma, Daqing

2014-01-01

Chronic allograft nephropathy (CAN) is a common finding in kidney grafts with functional impairment. Prolonged hypothermic storage-induced ischemia-reperfusion injury is associated with the early onset of CAN. As the noble gas xenon is clinically used as an anesthetic and has renoprotective properties in a rodent model of ischemia-reperfusion injury, we studied whether early treatment with xenon could attenuate CAN associated with prolonged hypothermic storage. Exposure to xenon enhanced the expression of insulin growth factor-1 (IGF-1) and its receptor in human proximal tubular (HK-2) cells, which, in turn, increased cell proliferation. Xenon treatment before or after hypothermia-hypoxia decreased cell apoptosis and cell inflammation after reoxygenation. The xenon-induced HK-2 cell proliferation was abolished by blocking the IGF-1 receptor, mTOR, and HIF-1α individually. In the Fischer-to-Lewis rat allogeneic renal transplantation model, xenon exposure of donors before graft retrieval or recipients after engraftment enhanced tubular cell proliferation and decreased tubular cell death and cell inflammation associated with ischemia-reperfusion injury. Compared with control allografts, xenon treatment significantly suppressed T-cell infiltration and fibrosis, prevented the development of CAN, and improved renal function. Thus, xenon treatment promoted recovery from ischemia-reperfusion injury and reduced susceptibility to the subsequent development of CAN in allografts.

Excess thermodynamics of mixtures involving xenon and light linear alkanes by computer simulation.

PubMed

Carvalho, A J Palace; Ramalho, J P Prates; Martins, Luís F G

2007-06-14

Excess molar enthalpies and excess molar volumes as a function of composition for liquid mixtures of xenon + ethane (at 161.40 K), xenon + propane (at 161.40 K) and xenon + n-butane (at 182.34 K) have been obtained by Monte Carlo computer simulations and compared with available experimental data. Simulation conditions were chosen to closely match those of the corresponding experimental results. The TraPPE-UA force field was selected among other force fields to model all the alkanes studied, whereas the one-center Lennard-Jones potential from Bohn et al. was used for xenon. The calculated H(m)(E) and V(m)(E) for all systems are negative, increasing in magnitude as the alkane chain length increases. The results for these systems were compared with experimental data and with other theoretical calculations using the SAFT approach. An excellent agreement between simulation and experimental results was found for xenon + ethane system, whereas for the remaining two systems, some deviations that become progressively more significant as the alkane chain length increases were observed.

Protection of xenon against postoperative oxygen impairment in adults undergoing Stanford Type-A acute aortic dissection surgery

PubMed Central

Jin, Mu; Cheng, Yi; Yang, Yanwei; Pan, Xudong; Lu, Jiakai; Cheng, Weiping

2017-01-01

Abstract Objectives: The available evidence shows that hypoxemia after Stanford Type-A acute aortic dissection (AAD) surgery is a frequent cause of several adverse consequences. The pathogenesis of postoperative hypoxemia after AAD surgery is complex, and ischemia/reperfusion and inflammation are likely to be underlying risk factors. Xenon, recognized as an ideal anesthetic and anti-inflammatory treatment, might be a possible treatment for these adverse effects. Methods/Design: The trial is a prospective, double-blind, 4-group, parallel, randomized controlled, a signal-center clinical trial. We will recruit 160 adult patients undergoing Stanford type-A AAD surgery. Patients will be allocated a study number and will be randomized on a 1:1:1:1 basis to receive 1 of the 3 treatment options (pulmonary inflated with 50% xenon, 75% xenon, or 100% xenon) or no treatment (control group, pulmonary inflated with 50% nitrogen). The aims of this study are to clarify the lung protection capability of xenon and its possible mechanisms in patients undergoing the Stanford type-A AAD surgery. Discussion: This trial uses an innovative design to account for the xenon effects of postoperative oxygen impairment, and it also delineates the mechanism for any benefit from xenon. The investigational xenon group is considered a treatment intervention, as it includes 3 groups of pulmonary static inflation with 50%, 75%, and 100% xenon. It is suggested that future trials might define an appropriate concentration of xenon for the best practice intervention. PMID:28834897

Physics reach of the XENON1T dark matter experiment

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

Aprile, E.; Anthony, M.; Aalbers, J.

2016-04-01

The XENON1T experiment is currently in the commissioning phase at the Laboratori Nazionali del Gran Sasso, Italy. In this article we study the experiment's expected sensitivity to the spin-independent WIMP-nucleon interaction cross section, based on Monte Carlo predictions of the electronic and nuclear recoil backgrounds. The total electronic recoil background in 1 tonne fiducial volume and (1, 12) keV electronic recoil equivalent energy region, before applying any selection to discriminate between electronic and nuclear recoils, is (1.80 ± 0.15) · 10{sup −4} (kg·day·keV){sup −1}, mainly due to the decay of {sup 222}Rn daughters inside the xenon target. The nuclear recoil background in the correspondingmore » nuclear recoil equivalent energy region (4, 50) keV, is composed of (0.6 ± 0.1) (t·y){sup −1} from radiogenic neutrons, (1.8 ± 0.3) · 10{sup −2} (t·y){sup −1} from coherent scattering of neutrinos, and less than 0.01 (t·y){sup −1} from muon-induced neutrons. The sensitivity of XENON1T is calculated with the Profile Likelihood Ratio method, after converting the deposited energy of electronic and nuclear recoils into the scintillation and ionization signals seen in the detector. We take into account the systematic uncertainties on the photon and electron emission model, and on the estimation of the backgrounds, treated as nuisance parameters. The main contribution comes from the relative scintillation efficiency L{sub eff}, which affects both the signal from WIMPs and the nuclear recoil backgrounds. After a 2 y measurement in 1 t fiducial volume, the sensitivity reaches a minimum cross section of 1.6 · 10{sup −47} cm{sup 2} at m{sub χ} = 50 GeV/c{sup 2}.« less

Measurement of radon and xenon binding to a cryptophane molecular host

PubMed Central

Jacobson, David R.; Khan, Najat S.; Collé, Ronald; Fitzgerald, Ryan; Laureano-Pérez, Lizbeth; Bai, Yubin; Dmochowski, Ivan J.

2011-01-01

Xenon and radon have many similar properties, a difference being that all 35 isotopes of radon (195Rn–229Rn) are radioactive. Radon is a pervasive indoor air pollutant believed to cause significant incidence of lung cancer in many geographic regions, yet radon affinity for a discrete molecular species has never been determined. By comparison, the chemistry of xenon has been widely studied and applied in science and technology. Here, both noble gases were found to bind with exceptional affinity to tris-(triazole ethylamine) cryptophane, a previously unsynthesized water-soluble organic host molecule. The cryptophane–xenon association constant, Ka = 42,000 ± 2,000 M-1 at 293 K, was determined by isothermal titration calorimetry. This value represents the highest measured xenon affinity for a host molecule. The partitioning of radon between air and aqueous cryptophane solutions of varying concentration was determined radiometrically to give the cryptophane–radon association constant Ka = 49,000 ± 12,000 M-1 at 293 K. PMID:21690357

Xenon neurotoxicity in rat hippocampal slice cultures is similar to isoflurane and sevoflurane.

PubMed

Brosnan, Heather; Bickler, Philip E

2013-08-01

Anesthetic neurotoxicity in the developing brain of rodents and primates has raised concern. Xenon may be a nonneurotoxic alternative to halogenated anesthetics, but its toxicity has only been studied at low concentrations, where neuroprotective effects predominate in animal models. An equipotent comparison of xenon and halogenated anesthetics with respect to neurotoxicity in developing neurons has not been made. Organotypic hippocampal cultures from 7-day-old rats were exposed to 0.75, 1, and 2 minimum alveolar concentrations (MAC) partial pressures (60% xenon at 1.2, 2.67, and 3.67 atm; isoflurane at 1.4, 1.9, and 3.8%; and sevoflurane at 3.4 and 6.8%) for 6 h, at atmospheric pressure or in a pressure chamber. Cell death was assessed 24 h later with fluorojade and fluorescent dye exclusion techniques. Xenon caused death of hippocampal neurons in CA1, CA3, and dentate regions after 1 and 2 MAC exposures, but not at 0.75 MAC. At 1 MAC, xenon increased cell death 40% above baseline (P < 0.01; ANOVA with Dunnett test). Both isoflurane and sevoflurane increased neuron death at 1 but not 2 MAC. At 1 MAC, the increase in cell death compared with controls was 63% with isoflurane and 90% with sevoflurane (both P < 0.001). Pretreatment of cultures with isoflurane (0.75 MAC) reduced neuron death after 1 MAC xenon, isoflurane, and sevoflurane. Xenon causes neuronal cell death in an in vitro model of the developing rodent brain at 1 MAC, as does isoflurane and sevoflurane at similarly potent concentrations. Preconditioning with a subtoxic dose of isoflurane eliminates this toxicity.

Venus, Earth, Xenon

NASA Astrophysics Data System (ADS)

Zahnle, K. J.

2013-12-01

Xenon has been regarded as an important goal of many proposed missions to Venus. This talk is intended to explain why. Despite its being the heaviest gas found in natural planetary atmospheres, there is more evidence that Xe escaped from Earth than for any element apart from helium: (i) Atmospheric Xe is very strongly mass fractionated (at about 4% per amu) from any known solar system source. This suggests fractionating escape that preferentially left the heavy Xe isotopes behind. (ii) Xe is underabundant compared to Kr, a lighter noble gas that is not strongly mass fractionated in air. (iii) Radiogenic Xe is strongly depleted by factors of several to ~100 compared to the quantities expected from radioactive decay of primordial solar system materials. In these respects Xe on Mars is similar to Xe on Earth, but with one key difference: Xe on Mars is readily explained by a simple process like hydrodynamic escape that acts on an initially solar or meteoritic Xe. This is not so for Earth. Earth's Xe cannot be derived by an uncontrived mass fractionating process acting on any known type of Solar System Xe. Earth is a stranger, made from different stuff than any known meteorite or Mars or even the Sun. Who else is in Earth's family? Comets? We know nothing. Father Zeus? Data from Jupiter are good enough to show that jovian Xe is not strongly mass-fractionated but not good enough to determine whether Jupiter resembles the Earth or the Sun. Sister Venus? Noble gas data from Venus are incomplete, with Kr uncertain and Xe unmeasured. Krypton was measured by several instruments on several spacecraft. The reported Kr abundances are discrepant and were once highly controversial. These discrepancies appear to have been not so much resolved as forgotten. Xenon was not detected on Venus. Upper limits were reported for the two most abundant xenon isotopes 129Xe and 132Xe. From the limited data it is not possible to tell whether Venus's affinities lie with the solar wind, or with

New constraints and prospects for sub-GeV dark matter scattering off electrons in xenon

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

Essig, Rouven; Volansky, Tomer; Yu, Tien-Tien

2017-08-30

We study in detail sub-GeV dark matter scattering off electrons in xenon, including the expected electron recoil spectra and annual modulation spectra. We derive improved constraints using low-energy XENON10 and XENON100 ionization-only data. For XENON10, in addition to including electron-recoil data corresponding to about 1–3 electrons, we include for the first time events corresponding to about 4–7 electrons. Assuming the scattering is momentum independent (F DM = 1 ), this strengthens a previous cross-section bound by almost an order of magnitude for dark matter masses above 50 MeV. The available XENON100 data corresponds to events with about 4–50 electrons, andmore » leads to a constraint that is comparable to the XENON10 bound above 50 MeV for F DM = 1 . We demonstrate that a search for an annual modulation signal in upcoming xenon experiments (XENON1T, XENONnT, LZ) could substantially improve the above bounds even in the presence of large backgrounds. We also emphasize that in simple benchmark models of sub-GeV dark matter, the dark matter-electron scattering rate can be as high as one event every ten (two) seconds in the XENON1T (XENONnT or LZ) experiments, without being in conflict with any other known experimental bounds. While there are several sources of backgrounds that can produce single- or few-electron events, a large event rate can be consistent with a dark matter signal and should not be simply written off as purely a detector curiosity. This fact motivates a detailed analysis of the ionization-data (“S2”) data, taking into account the expected annual modulation spectrum of the signal rate, as well as the DM-induced electron-recoil spectra, which are another powerful discriminant between signal and background.« less

New constraints and prospects for sub-GeV dark matter scattering off electrons in xenon

NASA Astrophysics Data System (ADS)

Essig, Rouven; Volansky, Tomer; Yu, Tien-Tien

2017-08-01

We study in detail sub-GeV dark matter scattering off electrons in xenon, including the expected electron recoil spectra and annual modulation spectra. We derive improved constraints using low-energy XENON10 and XENON100 ionization-only data. For XENON10, in addition to including electron-recoil data corresponding to about 1-3 electrons, we include for the first time events corresponding to about 4-7 electrons. Assuming the scattering is momentum independent (FDM=1 ), this strengthens a previous cross-section bound by almost an order of magnitude for dark matter masses above 50 MeV. The available XENON100 data corresponds to events with about 4-50 electrons, and leads to a constraint that is comparable to the XENON10 bound above 50 MeV for FDM=1 . We demonstrate that a search for an annual modulation signal in upcoming xenon experiments (XENON1T, XENONnT, LZ) could substantially improve the above bounds even in the presence of large backgrounds. We also emphasize that in simple benchmark models of sub-GeV dark matter, the dark matter-electron scattering rate can be as high as one event every ten (two) seconds in the XENON1T (XENONnT or LZ) experiments, without being in conflict with any other known experimental bounds. While there are several sources of backgrounds that can produce single- or few-electron events, a large event rate can be consistent with a dark matter signal and should not be simply written off as purely a detector curiosity. This fact motivates a detailed analysis of the ionization-data ("S2") data, taking into account the expected annual modulation spectrum of the signal rate, as well as the DM-induced electron-recoil spectra, which are another powerful discriminant between signal and background.

Microscopic simulation of xenon-based optical TPCs in the presence of molecular additives

NASA Astrophysics Data System (ADS)

Azevedo, C. D. R.; González-Díaz, D.; Biagi, S. F.; Oliveira, C. A. B.; Henriques, C. A. O.; Escada, J.; Monrabal, F.; Gómez-Cadenas, J. J.; Álvarez, V.; Benlloch-Rodríguez, J. M.; Borges, F. I. G. M.; Botas, A.; Cárcel, S.; Carrión, J. V.; Cebrián, S.; Conde, C. A. N.; Díaz, J.; Diesburg, M.; Esteve, R.; Felkai, R.; Fernandes, L. M. P.; Ferrario, P.; Ferreira, A. L.; Freitas, E. D. C.; Goldschmidt, A.; Gutiérrez, R. M.; Hauptman, J.; Hernandez, A. I.; Morata, J. A. Hernando; Herrero, V.; Jones, B. J. P.; Labarga, L.; Laing, A.; Lebrun, P.; Liubarsky, I.; Lopez-March, N.; Losada, M.; Martín-Albo, J.; Martínez-Lema, G.; Martínez, A.; McDonald, A. D.; Monteiro, C. M. B.; Mora, F. J.; Moutinho, L. M.; Vidal, J. Muñoz; Musti, M.; Nebot-Guinot, M.; Novella, P.; Nygren, D.; Palmeiro, B.; Para, A.; Pérez, J.; Querol, M.; Renner, J.; Ripoll, L.; Rodríguez, J.; Rogers, L.; Santos, F. P.; dos Santos, J. M. F.; Serra, L.; Shuman, D.; Simón, A.; Sofka, C.; Sorel, M.; Stiegler, T.; Toledo, J. F.; Torrent, J.; Tsamalaidze, Z.; Veloso, J. F. C. A.; Webb, R.; White, J. T.; Yahlali, N.

2018-01-01

We introduce a simulation framework for the transport of high and low energy electrons in xenon-based optical time projection chambers (OTPCs). The simulation relies on elementary cross sections (electron-atom and electron-molecule) and incorporates, in order to compute the gas scintillation, the reaction/quenching rates (atom-atom and atom-molecule) of the first 41 excited states of xenon and the relevant associated excimers, together with their radiative cascade. The results compare positively with observations made in pure xenon and its mixtures with CO2 and CF4 in a range of pressures from 0.1 to 10 bar. This work sheds some light on the elementary processes responsible for the primary and secondary xenon-scintillation mechanisms in the presence of additives, that are of interest to the OTPC technology.

CO adsorption on ion bombarded Ni(111): characterization by photoemission from adsorbed xenon

NASA Astrophysics Data System (ADS)

Fu, Sabrina S.; Malafsky, Geoffrey P.; Hsu, David S. Y.

1993-11-01

The adsorption of CO on Ni(111), ion bombarded with various fluences of 1.0 keV Ar + ions, has been investigated using photoemission from adsorbed xenon (PAX). After ion bombardment of the Ni(111) surface, various amounts of CO were adsorbed, followed by adsorption of xenon at 85 K. Two pressures of xenon were used in examining the 3d {5}/{2} peak of xenon: 5 × 10 -6 and 7 × 10 -10 Torr. PAX data taken at both pressures show that CO selectively adsorbs onto the defect (step) sites created by ion bombardment. In addition, it was found that the amount of CO which could occupy a defect site previously occupied by one Xe atom varied from 10 to 2.5, depending on the ion fluence.

New constraints and discovery potential of sub-GeV dark matter with xenon detectors

NASA Astrophysics Data System (ADS)

McCabe, Christopher

2017-08-01

Existing xenon dark matter (DM) direct detection experiments can probe the DM-nucleon interaction of DM with a sub-GeV mass through a search for photon emission from the recoiling xenon atom. We show that LUX's constraints on sub-GeV DM, which utilize the scintillation (S1) and ionization (S2) signals, are approximately 3 orders of magnitude more stringent than previous xenon constraints in this mass range, derived from the XENON10 and XENON100 S2-only searches. The new LUX constraints provide the most stringent direct detection constraints for DM particles with a mass below 0.5 GeV. In addition, the photon emission signal in LUX and its successor LZ maintain the discrimination between background and signal events so that an unambiguous discovery of sub-GeV DM is possible. We show that LZ has the potential to reconstruct the DM mass with ≃20 % accuracy for particles lighter than 0.5 GeV.

Status of the Large Underground Xenon (LUX) Detector

NASA Astrophysics Data System (ADS)

Larsen, Nicole

2012-03-01

The LUX (Large Underground Xenon) experiment is a 350-kg xenon-based direct dark matter detection experiment consisting of a two-phase (liquid/gas) xenon time projection chamber with a 100-kg fiducial mass. This technology has many advantages, including scalability, self-shielding, the absence of any long-lived isotopes, high gamma ray stopping power, and the ability to precisely measure the charge-to-light ratio of interactions within the detector, which provides an accurate method for discriminating between electron recoils (gamma rays, beta decays) and nuclear recoils (neutrons, WIMPS) within the detector. LUX's projected sensitivity for 300 days of acquisition is a cross-section of 7 x10-46 cm^2 for a WIMP mass of 100 GeV, representing an increase of nearly an order of magnitude over previous WIMP cross-section limits. From November 2011 through February 2012, LUX was deployed in a surface laboratory at the Homestake Mine in South Dakota for its second surface run. This talk will provide an overview of the LUX design and a report on the status of the experiment after the surface run and before underground deployment.

Progress on Acoustic Measurements of the Bulk Viscosity of Near-Critical Xenon (BVX)

NASA Technical Reports Server (NTRS)

Gillis, Keith A.; Shinder, Iosif I.; Moldover, Michael R.; Zimmerli, Gregory A.

2004-01-01

We plan to determine the bulk viscosity of xenon 10 times closer [in reduced temperature tau = (T-Tc)/Tc] to its liquid-vapor critical point than ever before. (Tc is the critical temperature.) To do so, we must measure the dispersion and attenuation of sound at frequencies 1/100 of those used previously. In general, sound attenuation has contributions from the bulk viscosity acting throughout the volume of the xenon as well as contributions from the thermal conductivity and the shear viscosity acting within thin thermoacoustic boundary layers at the interface between the xenon and the solid walls of the resonator. Thus, we can determine the bulk viscosity only when the boundary layer attenuation is small and well understood. We present a comparison of calculations and measurements of sound attenuation in the acoustic boundary layer of xenon near its liquid-vapor critical point.

XENON-133 IN CALIFORNIA, NEVADA, AND UTAH FROM THE CHERNOBYL ACCIDENT (JOURNAL VERSION)

EPA Science Inventory

The accident at the Chernobyl nuclear reactor in the USSR introduced numerous radioactive nuclides into the atmosphere, including the noble gas xenon-133. EPA's Environmental Monitoring Systems Laboratory, Las Vegas, NV, detected xenon-133 from the Chernobyl accident in air sampl...

40 CFR 426.124 - [Reserved

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 30 2011-07-01 2011-07-01 false [Reserved] 426.124 Section 426.124 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS GLASS MANUFACTURING POINT SOURCE CATEGORY Incandescent Lamp Envelope Manufacturing Subcategory § 426.124 [Reserved] ...

40 CFR 426.124 - [Reserved

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 29 2010-07-01 2010-07-01 false [Reserved] 426.124 Section 426.124 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS GLASS MANUFACTURING POINT SOURCE CATEGORY Incandescent Lamp Envelope Manufacturing Subcategory § 426.124 [Reserved] ...

Surface damage on polycrystalline β-SiC by xenon ion irradiation at high fluence

NASA Astrophysics Data System (ADS)

Baillet, J.; Gavarini, S.; Millard-Pinard, N.; Garnier, V.; Peaucelle, C.; Jaurand, X.; Duranti, A.; Bernard, C.; Rapegno, R.; Cardinal, S.; Escobar Sawa, L.; De Echave, T.; Lanfant, B.; Leconte, Y.

2018-05-01

Polycrystalline β-silicon carbide (β-SiC) pellets were prepared by Spark Plasma Sintering (SPS). These were implanted at room temperature with 800 keV xenon at ion fluences of 5.1015 and 1.1017 cm-2. Microstructural modifications were studied by electronic microscopy (TEM and SEM) and xenon profiles were determined by Rutherford Backscattering Spectroscopy (RBS). A complete amorphization of the implanted area associated with a significant oxidation is observed for the highest fluence. Large xenon bubbles formed in the oxide phase are responsible of surface swelling. No significant gas release has been measured up to 1017 at.cm-2. A model is proposed to explain the different steps of the oxidation process and xenon bubbles formation as a function of ion fluence.

Impact of neutrino background prediction for next generation dark matter xenon detector

NASA Astrophysics Data System (ADS)

Cadeddu, M.; Picciau, E.

2018-01-01

Next generation direct dark matter detectors will have the sensitivity to detect neutrinos from several sources, among which atmospheric and diffuse supernova neutrinos, through the Standard Model reaction of Coherent Elastic Neutrino Scattering on nucleus. This reaction represents an irreducible background that can be expressed as a limit in the Weakly Interacting Massive Particles parameters plane. This limit is known as the “neutrino floor” and it has been obtained by other authors considering standard hypotheses for the neutrino-nucleus form factor and for the coherence of the scattering process. Since the coherent scattering has never been observed experimentally, it is licit to relax some hypotheses in the differential cross section and to evaluate the effect of such modifications on the neutrino floor prediction. In this contribution, we show a more accurate neutrino-nucleus form factor and we discuss the coherence hypothesis of the process in two extreme cases, namely the total coherence and the total decoherence regime. We derive the neutrino background event rate under these new assumptions, considering xenon as a target. The differences between the number of neutrino events and the implication for the next generation dark matter detectors, such as XENON1T/XENONnT, LZ and DARWIN, are discussed.

Method for the simultaneous preparation of radon-211, xenon-125, xenon-123, astatine-211, iodine-125 and iodine-123

DOEpatents

Mirzadeh, S.; Lambrecht, R.M.

1985-07-01

The invention relates to a practical method for commercially producing radiopharmaceutical activities and, more particularly, relates to a method for the preparation of about equal amount of Radon-211 (/sup 211/Rn) and Xenon-125 (/sup 125/Xe) including a one-step chemical procedure following an irradiation procedure in which a selected target of Thorium (/sup 232/Th) or Uranium (/sup 238/U) is irradiated. The disclosed method is also effective for the preparation in a one-step chemical procedure of substantially equal amounts of high purity /sup 123/I and /sup 211/At. In one preferred arrangement of the invention almost equal quantities of /sup 211/Rn and /sup 125/Xe are prepared using a onestep chemical procedure in which a suitably irradiated fertile target material, such as thorium-232 or uranium-238, is treated to extract those radionuclides from it. In the same one-step chemical procedure about equal quantities of /sup 211/At and /sup 123/I are prepared and stored for subsequent use. In a modified arrangement of the method of the invention, it is practiced to separate and store about equal amounts of only /sup 211/Rn and /sup 125/Xe, while preventing the extraction or storage of the radionuclides /sup 211/At and /sup 123/I.

Parallel Analysis of 124 Universal SNPs for Human Identification by Targeted Semiconductor Sequencing

PubMed Central

Zhang, Suhua; Bian, Yingnan; Zhang, Zheren; Zheng, Hancheng; Wang, Zheng; Zha, Lagabaiyila; Cai, Jifeng; Gao, Yuzhen; Ji, Chaoneng; Hou, Yiping; Li, Chengtao

2015-01-01

SNPs, abundant in human genome with lower mutation rate, are attractive to genetic application like forensic, anthropological and evolutionary studies. Universal SNPs showing little allelic frequency variation among populations while remaining highly informative for human identification were obtained from previous studies. However, genotyping tools target only dozens of markers simultaneously, limiting their applications. Here, 124 SNPs were simultaneous tested using Ampliseq technology with Ion Torrent PGM platform. Concordance study was performed with 2 reference samples of 9947A and 9948 between NGS and Sanger sequencing. Full concordance were obtained except genotype of rs576261 with 9947A. Parameter of FMAR (%) was introduced for NGS data analysis for the first time, evaluating allelic performance, sensitivity testing and mixture testing. FMAR values for accurate heterozygotes should be range from 50% to 60%, for homozygotes or Y-SNP should be above 90%. SNPs of rs7520386, rs4530059, rs214955, rs1523537, rs2342747, rs576261 and rs12997453 were recognized as poorly performing loci, either with allelic imbalance or with lower coverage. Sensitivity testing demonstrated that with DNA range from 10 ng-0.5 ng, all correct genotypes were obtained. For mixture testing, a clear linear correlation (R2 = 0.9429) between the excepted FMAR and observed FMAR values of mixtures was observed. PMID:26691610

40 CFR 82.124 - Prohibitions.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 17 2010-07-01 2010-07-01 false Prohibitions. 82.124 Section 82.124 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) PROTECTION OF STRATOSPHERIC OZONE The Labeling of Products Using Ozone-Depleting Substances § 82.124 Prohibitions. (a) Warning...

40 CFR 82.124 - Prohibitions.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 17 2011-07-01 2011-07-01 false Prohibitions. 82.124 Section 82.124 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) PROTECTION OF STRATOSPHERIC OZONE The Labeling of Products Using Ozone-Depleting Substances § 82.124 Prohibitions. (a) Warning...

18 CFR 401.124 - Construction.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 18 Conservation of Power and Water Resources 2 2010-04-01 2010-04-01 false Construction. 401.124 Section 401.124 Conservation of Power and Water Resources DELAWARE RIVER BASIN COMMISSION ADMINISTRATIVE MANUAL RULES OF PRACTICE AND PROCEDURE General Provisions § 401.124 Construction. This part is...

18 CFR 401.124 - Construction.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 18 Conservation of Power and Water Resources 2 2012-04-01 2012-04-01 false Construction. 401.124 Section 401.124 Conservation of Power and Water Resources DELAWARE RIVER BASIN COMMISSION ADMINISTRATIVE MANUAL RULES OF PRACTICE AND PROCEDURE General Provisions § 401.124 Construction. This part is...

18 CFR 401.124 - Construction.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 18 Conservation of Power and Water Resources 2 2013-04-01 2012-04-01 true Construction. 401.124 Section 401.124 Conservation of Power and Water Resources DELAWARE RIVER BASIN COMMISSION ADMINISTRATIVE MANUAL RULES OF PRACTICE AND PROCEDURE General Provisions § 401.124 Construction. This part is...

18 CFR 401.124 - Construction.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 18 Conservation of Power and Water Resources 2 2014-04-01 2014-04-01 false Construction. 401.124 Section 401.124 Conservation of Power and Water Resources DELAWARE RIVER BASIN COMMISSION ADMINISTRATIVE MANUAL RULES OF PRACTICE AND PROCEDURE General Provisions § 401.124 Construction. This part is...

49 CFR 195.124 - Closures.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 49 Transportation 3 2013-10-01 2013-10-01 false Closures. 195.124 Section 195.124 Transportation Other Regulations Relating to Transportation (Continued) PIPELINE AND HAZARDOUS MATERIALS SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) PIPELINE SAFETY TRANSPORTATION OF HAZARDOUS LIQUIDS BY PIPELINE Design Requirements § 195.124...

49 CFR 195.124 - Closures.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 49 Transportation 3 2012-10-01 2012-10-01 false Closures. 195.124 Section 195.124 Transportation Other Regulations Relating to Transportation (Continued) PIPELINE AND HAZARDOUS MATERIALS SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) PIPELINE SAFETY TRANSPORTATION OF HAZARDOUS LIQUIDS BY PIPELINE Design Requirements § 195.124...

49 CFR 195.124 - Closures.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 49 Transportation 3 2010-10-01 2010-10-01 false Closures. 195.124 Section 195.124 Transportation Other Regulations Relating to Transportation (Continued) PIPELINE AND HAZARDOUS MATERIALS SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) PIPELINE SAFETY TRANSPORTATION OF HAZARDOUS LIQUIDS BY PIPELINE Design Requirements § 195.124...

49 CFR 195.124 - Closures.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 49 Transportation 3 2011-10-01 2011-10-01 false Closures. 195.124 Section 195.124 Transportation Other Regulations Relating to Transportation (Continued) PIPELINE AND HAZARDOUS MATERIALS SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) PIPELINE SAFETY TRANSPORTATION OF HAZARDOUS LIQUIDS BY PIPELINE Design Requirements § 195.124...

49 CFR 195.124 - Closures.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 49 Transportation 3 2014-10-01 2014-10-01 false Closures. 195.124 Section 195.124 Transportation Other Regulations Relating to Transportation (Continued) PIPELINE AND HAZARDOUS MATERIALS SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) PIPELINE SAFETY TRANSPORTATION OF HAZARDOUS LIQUIDS BY PIPELINE Design Requirements § 195.124...

18 CFR 401.124 - Construction.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 18 Conservation of Power and Water Resources 2 2011-04-01 2011-04-01 false Construction. 401.124 Section 401.124 Conservation of Power and Water Resources DELAWARE RIVER BASIN COMMISSION ADMINISTRATIVE MANUAL RULES OF PRACTICE AND PROCEDURE General Provisions § 401.124 Construction. This part is...

Experimental investigations of argon and xenon ion sources

NASA Technical Reports Server (NTRS)

Kaufman, H. R.

1975-01-01

The multipole thruster was used to investigate the use of argon and xenon propellants as possible alternatives to the electric thruster propellants of mercury and cesium. The multipole approach was used because of its general high performance level. The design employed, using flat and cylindrical rolled sections of sheet metal, was selected for ease of fabrication, design, assembly, and modification. All testing was conducted in a vacuum facility and the pumping was accomplished by a 0.8 m diffusion pump together with liquid nitrogen cooled liner. Minimum discharge losses were in the 200-250 ev. ion range for both argon and xenon. Flatness parameters were typically in the 0.70-0.75 range.

45 CFR 690.124 - Conditions.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 45 Public Welfare 3 2014-10-01 2014-10-01 false Conditions. 690.124 Section 690.124 Public Welfare Regulations Relating to Public Welfare (Continued) NATIONAL SCIENCE FOUNDATION PROTECTION OF HUMAN SUBJECTS § 690.124 Conditions. With respect to any research project or any class of research projects the...

45 CFR 690.124 - Conditions.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 45 Public Welfare 3 2013-10-01 2013-10-01 false Conditions. 690.124 Section 690.124 Public Welfare Regulations Relating to Public Welfare (Continued) NATIONAL SCIENCE FOUNDATION PROTECTION OF HUMAN SUBJECTS § 690.124 Conditions. With respect to any research project or any class of research projects the...

45 CFR 690.124 - Conditions.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 45 Public Welfare 3 2012-10-01 2012-10-01 false Conditions. 690.124 Section 690.124 Public Welfare Regulations Relating to Public Welfare (Continued) NATIONAL SCIENCE FOUNDATION PROTECTION OF HUMAN SUBJECTS § 690.124 Conditions. With respect to any research project or any class of research projects the...

34 CFR 97.124 - Conditions.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 34 Education 1 2010-07-01 2010-07-01 false Conditions. 97.124 Section 97.124 Education Office of the Secretary, Department of Education PROTECTION OF HUMAN SUBJECTS Federal Policy for the Protection of Human Subjects (Basic ED Policy for Protection of Human Research Subjects) § 97.124 Conditions...

45 CFR 690.124 - Conditions.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 45 Public Welfare 3 2011-10-01 2011-10-01 false Conditions. 690.124 Section 690.124 Public Welfare Regulations Relating to Public Welfare (Continued) NATIONAL SCIENCE FOUNDATION PROTECTION OF HUMAN SUBJECTS § 690.124 Conditions. With respect to any research project or any class of research projects the...

45 CFR 690.124 - Conditions.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 45 Public Welfare 3 2010-10-01 2010-10-01 false Conditions. 690.124 Section 690.124 Public Welfare Regulations Relating to Public Welfare (Continued) NATIONAL SCIENCE FOUNDATION PROTECTION OF HUMAN SUBJECTS § 690.124 Conditions. With respect to any research project or any class of research projects the...

9 CFR 124.1 - Scope.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Scope. 124.1 Section 124.1 Animals and Animal Products ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE VIRUSES, SERUMS, TOXINS, AND ANALOGOUS PRODUCTS; ORGANISMS AND VECTORS PATENT TERM RESTORATION General Provisions § 124.1...

7 CFR 959.124 - Reports.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 7 Agriculture 8 2013-01-01 2013-01-01 false Reports. 959.124 Section 959.124 Agriculture... Regulations Safeguards § 959.124 Reports. Each handler of onions shipping under Certificates of Privilege shall supply the committee with reports as requested by the committee, or its duly authorized agents...

7 CFR 948.124 - Reports.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 7 Agriculture 8 2014-01-01 2014-01-01 false Reports. 948.124 Section 948.124 Agriculture... Rules and Regulations Safeguards § 948.124 Reports. Each handler of potatoes shipping under Certificates of Privilege shall supply the committee with reports as requested by the committee or its duly...

7 CFR 959.124 - Reports.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 7 Agriculture 8 2014-01-01 2014-01-01 false Reports. 959.124 Section 959.124 Agriculture... Regulations Safeguards § 959.124 Reports. Each handler of onions shipping under Certificates of Privilege shall supply the committee with reports as requested by the committee, or its duly authorized agents...

7 CFR 948.124 - Reports.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 7 Agriculture 8 2013-01-01 2013-01-01 false Reports. 948.124 Section 948.124 Agriculture... Rules and Regulations Safeguards § 948.124 Reports. Each handler of potatoes shipping under Certificates of Privilege shall supply the committee with reports as requested by the committee or its duly...

Measurement of aircraft xenon strobe light characteristics

DOT National Transportation Integrated Search

1976-08-01

This report provides data on the characteristics of aircraft xenon strobe lights related to their potential for use as the cooperative element in Optical IR (Infrared) Airborne Proximity Warning Indicator (APWI) systems. It includes a description of ...

A biochemical approach to identifying microRNA targets

PubMed Central

Karginov, Fedor V.; Conaco, Cecilia; Xuan, Zhenyu; Schmidt, Bryan H.; Parker, Joel S.; Mandel, Gail; Hannon, Gregory J.

2007-01-01

Identifying the downstream targets of microRNAs (miRNAs) is essential to understanding cellular regulatory networks. We devised a direct biochemical method for miRNA target discovery that combined RNA-induced silencing complex (RISC) purification with microarray analysis of bound mRNAs. Because targets of miR-124a have been analyzed, we chose it as our model. We honed our approach both by examining the determinants of stable binding between RISC and synthetic target RNAs in vitro and by determining the dependency of both repression and RISC coimmunoprecipitation on miR-124a seed sites in two of its well characterized targets in vivo. Examining the complete spectrum of miR-124 targets in 293 cells yielded both a set that were down-regulated at the mRNA level, as previously observed, and a set whose mRNA levels were unaffected by miR-124a. Reporter assays validated both classes, extending the spectrum of mRNA targets that can be experimentally linked to the miRNA pathway. PMID:18042700

Chondritic xenon in the Earth's mantle.

PubMed

Caracausi, Antonio; Avice, Guillaume; Burnard, Peter G; Füri, Evelyn; Marty, Bernard

2016-05-05

Noble gas isotopes are powerful tracers of the origins of planetary volatiles, and the accretion and evolution of the Earth. The compositions of magmatic gases provide insights into the evolution of the Earth's mantle and atmosphere. Despite recent analytical progress in the study of planetary materials and mantle-derived gases, the possible dual origin of the planetary gases in the mantle and the atmosphere remains unconstrained. Evidence relating to the relationship between the volatiles within our planet and the potential cosmochemical end-members is scarce. Here we show, using high-precision analysis of magmatic gas from the Eifel volcanic area (in Germany), that the light xenon isotopes identify a chondritic primordial component that differs from the precursor of atmospheric xenon. This is consistent with an asteroidal origin for the volatiles in the Earth's mantle, and indicates that the volatiles in the atmosphere and mantle originated from distinct cosmochemical sources. Furthermore, our data are consistent with the origin of Eifel magmatism being a deep mantle plume. The corresponding mantle source has been isolated from the convective mantle since about 4.45 billion years ago, in agreement with models that predict the early isolation of mantle domains. Xenon isotope systematics support a clear distinction between mid-ocean-ridge and continental or oceanic plume sources, with chemical heterogeneities dating back to the Earth's accretion. The deep reservoir now sampled by the Eifel gas had a lower volatile/refractory (iodine/plutonium) composition than the shallower mantle sampled by mid-ocean-ridge volcanism, highlighting the increasing contribution of volatile-rich material during the first tens of millions of years of terrestrial accretion.

MicroRNA-124-3p expression and its prospective functional pathways in hepatocellular carcinoma: A quantitative polymerase chain reaction, gene expression omnibus and bioinformatics study.

PubMed

He, Rong-Quan; Yang, Xia; Liang, Liang; Chen, Gang; Ma, Jie

2018-04-01

The present study aimed to explore the potential clinical significance of microRNA (miR)-124-3p expression in the hepatocarcinogenesis and development of hepatocellular carcinoma (HCC), as well as the potential target genes of functional HCC pathways. Reverse transcription-quantitative polymerase chain reaction was performed to evaluate the expression of miR-124-3p in 101 HCC and adjacent non-cancerous tissue samples. Additionally, the association between miR-124-3p expression and clinical parameters was also analyzed. Differentially expressed genes identified following miR-124-3p transfection, the prospective target genes predicted in silico and the key genes of HCC obtained from Natural Language Processing (NLP) were integrated to obtain potential target genes of miR-124-3p in HCC. Relevant signaling pathways were assessed with protein-protein interaction (PPI) networks, Gene Ontology (GO) enrichment analysis, Kyoto Encyclopedia of Genes and Genomes (KEGG) and Protein Annotation Through Evolutionary Relationships (PANTHER) pathway enrichment analysis. miR-124-3p expression was significantly reduced in HCC tissues compared with expression in adjacent non-cancerous liver tissues. In HCC, miR-124-3p was demonstrated to be associated with clinical stage. The mean survival time of the low miR-124-3p expression group was reduced compared with that of the high expression group. A total of 132 genes overlapped from differentially expressed genes, miR-124-3p predicted target genes and NLP identified genes. PPI network construction revealed a total of 109 nodes and 386 edges, and 20 key genes were identified. The major enriched terms of three GO categories included regulation of cell proliferation, positive regulation of cellular biosynthetic processes, cell leading edge, cytosol and cell projection, protein kinase activity, transcription activator activity and enzyme binding. KEGG analysis revealed pancreatic cancer, prostate cancer and non-small cell lung cancer as the

7 CFR 1221.124 - Reports.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 7 Agriculture 10 2012-01-01 2012-01-01 false Reports. 1221.124 Section 1221.124 Agriculture... INFORMATION ORDER Sorghum Promotion, Research, and Information Order Reports, Books, and Records § 1221.124 Reports. (a) Each first handler, on a State-by-State basis, will be required to provide to the Board...

7 CFR 945.124 - Reports.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 7 Agriculture 8 2014-01-01 2014-01-01 false Reports. 945.124 Section 945.124 Agriculture... § 945.124 Reports. Each handler of potatoes shipping under Certificates of Privilege shall supply the committee with reports as requested by the committee or its duly authorized agents showing the name and...

7 CFR 945.124 - Reports.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 7 Agriculture 8 2013-01-01 2013-01-01 false Reports. 945.124 Section 945.124 Agriculture... § 945.124 Reports. Each handler of potatoes shipping under Certificates of Privilege shall supply the committee with reports as requested by the committee or its duly authorized agents showing the name and...

7 CFR 1221.124 - Reports.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 7 Agriculture 10 2010-01-01 2010-01-01 false Reports. 1221.124 Section 1221.124 Agriculture... INFORMATION ORDER Sorghum Promotion, Research, and Information Order Reports, Books, and Records § 1221.124 Reports. (a) Each first handler, on a State-by-State basis, will be required to provide to the Board...

High pressure xenon ionization detector

DOEpatents

Markey, J.K.

1989-11-14

A method is provided for detecting ionization comprising allowing particles that cause ionization to contact high pressure xenon maintained at or near its critical point and measuring the amount of ionization. An apparatus is provided for detecting ionization, the apparatus comprising a vessel containing a ionizable medium, the vessel having an inlet to allow high pressure ionizable medium to enter the vessel, a means to permit particles that cause ionization of the medium to enter the vessel, an anode, a cathode, a grid and a plurality of annular field shaping rings, the field shaping rings being electrically isolated from one another, the anode, cathode, grid and field shaping rings being electrically isolated from one another in order to form an electric field between the cathode and the anode, the electric field originating at the anode and terminating at the cathode, the grid being disposed between the cathode and the anode, the field shaping rings being disposed between the cathode and the grid, the improvement comprising the medium being xenon and the vessel being maintained at a pressure of 50 to 70 atmospheres and a temperature of 0 to 30 C. 2 figs.

High pressure xenon ionization detector

DOEpatents

Markey, John K.

1989-01-01

A method is provided for detecting ionization comprising allowing particles that cause ionization to contact high pressure xenon maintained at or near its critical point and measuring the amount of ionization. An apparatus is provided for detecting ionization, the apparatus comprising a vessel containing a ionizable medium, the vessel having an inlet to allow high pressure ionizable medium to enter the vessel, a means to permit particles that cause ionization of the medium to enter the vessel, an anode, a cathode, a grid and a plurality of annular field shaping rings, the field shaping rings being electrically isolated from one another, the anode, cathode, grid and field shaping rings being electrically isolated from one another in order to form an electric field between the cathode and the anode, the electric field originating at the anode and terminating at the cathode, the grid being disposed between the cathode and the anode, the field shaping rings being disposed between the cathode and the grid, the improvement comprising the medium being xenon and the vessel being maintained at a pressure of 50 to 70 atmospheres and a temperature of 0.degree. to 30.degree. C.

Xenon adsorption on geological media and implications for radionuclide signatures

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

Paul, M. J.; Biegalski, S. R.; Haas, D. A.

Here, the detection of radioactive noble gases is a primary technology for verifying compliance with the pending Comprehensive Nuclear-Test-Ban Treaty. A fundamental challenge in applying this technology for detecting underground nuclear explosions is estimating the timing and magnitude of the radionuclide signatures. While the primary mechanism for transport is advective transport, either through barometric pumping or thermally driven advection, diffusive transport in the surrounding matrix also plays a secondary role. From the study of primordial noble gas signatures, it is known that xenon has a strong physical adsorption affinity in shale formations. Given the unselective nature of physical adsorption, isothermmore » measurements reported here show that non-trivial amounts of xenon adsorb on a variety of media, in addition to shale. A dual-porosity model is then discussed demonstrating that sorption amplifies the diffusive uptake of an adsorbing matrix from a fracture. This effect may reduce the radioxenon signature down to approximately one-tenth, similar to primordial xenon isotopic signatures.« less

Xenon adsorption on geological media and implications for radionuclide signatures

DOE PAGES

Paul, M. J.; Biegalski, S. R.; Haas, D. A.; ...

2018-02-13

Here, the detection of radioactive noble gases is a primary technology for verifying compliance with the pending Comprehensive Nuclear-Test-Ban Treaty. A fundamental challenge in applying this technology for detecting underground nuclear explosions is estimating the timing and magnitude of the radionuclide signatures. While the primary mechanism for transport is advective transport, either through barometric pumping or thermally driven advection, diffusive transport in the surrounding matrix also plays a secondary role. From the study of primordial noble gas signatures, it is known that xenon has a strong physical adsorption affinity in shale formations. Given the unselective nature of physical adsorption, isothermmore » measurements reported here show that non-trivial amounts of xenon adsorb on a variety of media, in addition to shale. A dual-porosity model is then discussed demonstrating that sorption amplifies the diffusive uptake of an adsorbing matrix from a fracture. This effect may reduce the radioxenon signature down to approximately one-tenth, similar to primordial xenon isotopic signatures.« less

Intrabullous ventilation in pulmonary emphysema: assessment with dynamic xenon-133 gas SPECT.

PubMed

Suga, Kazuyoshi; Iwanaga, Hideyuki; Tokuda, Osamu; Okada, Munemasa; Matsunaga, Naofumi

2012-04-01

Intrabullous ventilation in patients with pulmonary emphysema (PE) was cross-sectionally evaluated using dynamic xenon-133 gas single photon emission computed tomography (SPECT). Fifty-two patients with PE with a total of 109 bullae of more than 4 cm in maximum diameter underwent xenon-133 gas SPECT. The real xenon-133 gas half-clearance time (T1/2) at each bulla was compared with that at the surrounding lung in the same lobe. The emphysema subtype of the surrounding lung was classified into centrilobular, panlobular, and paraseptal on computed tomography (CT). All bullae except for one in all patients showed xenon-133 gas wash-in. Of the 108 bullae with wash-in, 95 (87.9%) bullae in 46 (88%) patients showed marked xenon-133 gas retention with a T1/2 beyond 110 s (mean: 184 s ± 91). The surrounding lungs of these bullae also showed marked retention with a T1/2 of greater than 100 s (mean: 174 s ± 82), and the majority (N=92, 96.8%) were centrilobular or panlobular on CT. The remaining 13 (12.0%) bullae in six (11%) patients showed minimal retention with a T1/2 of less than 80 s (mean: 62 s ± 11), regardless of no significant difference in size compared with the bullae with marked retention. All the surrounding lungs of these bullae except for one also showed minimal retention with a T1/2 of less than 70 s (mean: 60 s ± 18), which was significantly less compared with that of the bullae with marked retention (P<0.0001), and the majority (N=11, 84.6%) were paraseptal with or without an interstitially fibrotic change and predominantly located at the lower lung lobe on CT. The T1/2 of the 108 bullae with xenon-133 gas wash-in was significantly correlated with that of the surrounding lungs (r=0.884, P<0.0001). Intrabullous ventilation in patients with PE appears to depend on the ventilation status of the surrounding lung, and bullae with the surrounding lungs of paraseptal-type emphysema tend to show minimal air trapping. Xenon-133 gas SPECT is useful for assessment

Intrinsic backgrounds from Rn and Kr in the XENON100 experiment

NASA Astrophysics Data System (ADS)

Aprile, E.; Aalbers, J.; Agostini, F.; Alfonsi, M.; Amaro, F. D.; Anthony, M.; Arneodo, F.; Barrow, P.; Baudis, L.; Bauermeister, B.; Benabderrahmane, M. L.; Berger, T.; Breur, P. A.; Brown, A.; Brown, E.; Bruenner, S.; Bruno, G.; Budnik, R.; Bütikofer, L.; Calvén, J.; Cardoso, J. M. R.; Cervantes, M.; Cichon, D.; Coderre, D.; Colijn, A. P.; Conrad, J.; Cussonneau, J. P.; Decowski, M. P.; de Perio, P.; Di Gangi, P.; Di Giovanni, A.; Diglio, S.; Eurin, G.; Fei, J.; Ferella, A. D.; Fieguth, A.; Fulgione, W.; Gallo Rosso, A.; Galloway, M.; Gao, F.; Garbini, M.; Geis, C.; Goetzke, L. W.; Greene, Z.; Grignon, C.; Hasterok, C.; Hogenbirk, E.; Itay, R.; Kaminsky, B.; Kazama, S.; Kessler, G.; Kish, A.; Landsman, H.; Lang, R. F.; Lellouch, D.; Levinson, L.; Lin, Q.; Lindemann, S.; Lindner, M.; Lombardi, F.; Lopes, J. A. M.; Manfredini, A.; Maris, I.; Marrodán Undagoitia, T.; Masbou, J.; Massoli, F. V.; Masson, D.; Mayani, D.; Messina, M.; Micheneau, K.; Molinario, A.; Morå, K.; Murra, M.; Naganoma, J.; Ni, K.; Oberlack, U.; Pakarha, P.; Pelssers, B.; Persiani, R.; Piastra, F.; Pienaar, J.; Piro, M.-C.; Pizzella, V.; Plante, G.; Priel, N.; Ramírez García, D.; Rauch, L.; Reichard, S.; Reuter, C.; Rizzo, A.; Rupp, N.; dos Santos, J. M. F.; Sartorelli, G.; Scheibelhut, M.; Schindler, S.; Schreiner, J.; Schumann, M.; Lavina, L. Scotto; Selvi, M.; Shagin, P.; Silva, M.; Simgen, H.; Sivers, M. Von; Stein, A.; Thers, D.; Tiseni, A.; Trinchero, G.; Tunnell, C.; Vargas, M.; Wang, H.; Wang, Z.; Weber, M.; Wei, Y.; Weinheimer, C.; Wittweg, C.; Wulf, J.; Ye, J.; Zhang, Y.

2018-02-01

In this paper, we describe the XENON100 data analyses used to assess the target-intrinsic background sources radon (?), thoron (?) and krypton (?). We detail the event selections of high-energy alpha particles and decay-specific delayed coincidences. We derive distributions of the individual radionuclides inside the detector and quantify their abundances during the main three science runs of the experiment over a period of ˜ 4 years, from January 2010 to January 2014. We compare our results to external measurements of radon emanation and krypton concentrations where we find good agreement. We report an observed reduction in concentrations of radon daughters that we attribute to the plating-out of charged ions on the negatively biased cathode.

Assessment of regional emphysema, air-trapping and Xenon-ventilation using dual-energy computed tomography in chronic obstructive pulmonary disease patients.

PubMed

Lee, Sang Min; Seo, Joon Beom; Hwang, Hye Jeon; Kim, Namkug; Oh, Sang Young; Lee, Jae Seung; Lee, Sei Won; Oh, Yeon-Mok; Kim, Tae Hoon

2017-07-01

To compare the parenchymal attenuation change between inspiration/expiration CTs with dynamic ventilation change between xenon wash-in (WI) inspiration and wash-out (WO) expiration CTs. 52 prospectively enrolled COPD patients underwent xenon ventilation dual-energy CT during WI and WO periods and pulmonary function tests (PFTs). The parenchymal attenuation parameters (emphysema index (EI), gas-trapping index (GTI) and air-trapping index (ATI)) and xenon ventilation parameters (xenon in WI (Xe-WI), xenon in WO (Xe-WO) and xenon dynamic (Xe-Dyna)) of whole lung and three divided areas (emphysema, hyperinflation and normal) were calculated on virtual non-contrast images and ventilation images. Pearson correlation, linear regression analysis and one-way ANOVA were performed. EI, GTI and ATI showed a significant correlation with Xe-WI, Xe-WO and Xe-Dyna (EI R = -.744, -.562, -.737; GTI R = -.621, -.442, -.629; ATI R = -.600, -.421, -.610, respectively, p < 0.01). All CT parameters showed significant correlation with PFTs except forced vital capacity (FVC). There was a significant difference in GTI, ATI and Xe-Dyna in each lung area (p < 0.01). The parenchymal attenuation change between inspiration/expiration CTs and xenon dynamic change between xenon WI- and WO-CTs correlate significantly. There are alterations in the dynamics of xenon ventilation between areas of emphysema. • The xenon ventilation change correlates with the parenchymal attenuation change. • The xenon ventilation change shows the difference between three lung areas. • The combination of attenuation and xenon can predict more accurate PFTs.

24 CFR 884.124 - Audit.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 24 Housing and Urban Development 4 2010-04-01 2010-04-01 false Audit. 884.124 Section 884.124... HOUSING PROJECTS Applicability, Scope and Basic Policies § 884.124 Audit. (a) Where a State or local..., receiving financial assistance under this part, the audit requirements in 24 CFR part 44 shall apply. (b...

24 CFR 882.124 - Audit.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 24 Housing and Urban Development 4 2010-04-01 2010-04-01 false Audit. 882.124 Section 882.124...) SECTION 8 MODERATE REHABILITATION PROGRAMS Applicability, Scope and Basic Policies § 882.124 Audit. PHAs receiving financial assistance under this part are subject to audit requirements in 24 CFR part 44. [50 FR...

42 CFR 124.2 - Definitions.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 42 Public Health 1 2011-10-01 2011-10-01 false Definitions. 124.2 Section 124.2 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES HEALTH RESOURCES DEVELOPMENT MEDICAL FACILITY CONSTRUCTION AND MODERNIZATION Project Grants for Public Medical Facility Construction and Modernization § 124.2 Definitions. As used in this...

42 CFR 124.2 - Definitions.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 42 Public Health 1 2014-10-01 2014-10-01 false Definitions. 124.2 Section 124.2 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES HEALTH RESOURCES DEVELOPMENT MEDICAL FACILITY CONSTRUCTION AND MODERNIZATION Project Grants for Public Medical Facility Construction and Modernization § 124.2 Definitions. As used in this...

42 CFR 124.2 - Definitions.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 42 Public Health 1 2012-10-01 2012-10-01 false Definitions. 124.2 Section 124.2 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES HEALTH RESOURCES DEVELOPMENT MEDICAL FACILITY CONSTRUCTION AND MODERNIZATION Project Grants for Public Medical Facility Construction and Modernization § 124.2 Definitions. As used in this...

42 CFR 124.2 - Definitions.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 42 Public Health 1 2010-10-01 2010-10-01 false Definitions. 124.2 Section 124.2 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES HEALTH RESOURCES DEVELOPMENT MEDICAL FACILITY CONSTRUCTION AND MODERNIZATION Project Grants for Public Medical Facility Construction and Modernization § 124.2 Definitions. As used in this...

42 CFR 124.2 - Definitions.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 42 Public Health 1 2013-10-01 2013-10-01 false Definitions. 124.2 Section 124.2 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES HEALTH RESOURCES DEVELOPMENT MEDICAL FACILITY CONSTRUCTION AND MODERNIZATION Project Grants for Public Medical Facility Construction and Modernization § 124.2 Definitions. As used in this...

14 CFR 1264.124 - Fees.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 5 2010-01-01 2010-01-01 false Fees. 1264.124 Section 1264.124 Aeronautics and Space NATIONAL AERONAUTICS AND SPACE ADMINISTRATION IMPLEMENTATION OF THE PROGRAM FRAUD CIVIL PENALTIES ACT OF 1986 § 1264.124 Fees. The party requesting a supoena shall pay the cost of the fees and...

Xenon migration in UO2 under irradiation studied by SIMS profilometry

NASA Astrophysics Data System (ADS)

Marchand, B.; Moncoffre, N.; Pipon, Y.; Bérerd, N.; Garnier, C.; Raimbault, L.; Sainsot, P.; Epicier, T.; Delafoy, C.; Fraczkiewicz, M.; Gaillard, C.; Toulhoat, N.; Perrat-Mabilon, A.; Peaucelle, C.

2013-09-01

During Pressurized Water Reactor operation, around 25% of the created Fission Products (FP) are Xenon and Krypton. They have a low solubility in the nuclear fuel and can either (i) agglomerate into bubbles which induce mechanical stress in the fuel pellets or (ii) be released from the pellets, increasing the pressure within the cladding and decreasing the thermal conductivity of the gap between pellets and cladding. After fifty years of studies on the nuclear fuel, all mechanisms of Fission Gas Release (FGR) are still not fully understood. This paper aims at studying the FGR mechanisms by decoupling thermal and irradiation effects and by assessing the Xenon behavior for the first time by profilometry. Samples are first implanted with 136Xe at 800 keV corresponding to a projected range of 140 nm. They are then either annealed in the temperature range 1400-1600 °C, or irradiated with heavy energy ions (182 MeV Iodine) at Room Temperature (RT), 600 °C or 1000 °C. Depth profiles of implanted Xenon in UO2 are determined by Secondary Ion Mass Spectrometry (SIMS). It is shown that Xenon is mobile during irradiation at 1000 °C. In contrast, thermal treatments do not induce any Xenon migration process: these results are correlated to the formation of Xenon bubbles observed by Transmission Electron Microscopy. At depths lower than about 40 nm (zone 1), no bubbles are observed, At depths in between 40 nm and 110 nm (zone 2), a large number of small bubbles (around 2 nm in diameter) can be observed. By comparing with the SRIM profile, it appears that this area corresponds to the maximum of the defect profile, The third zone displays two bubble populations. The first population has the same size than the bubbles present in zone 2. The bubble size of the second population is significantly larger (up to around 10 nm). A STEM micrograph is presented in Fig. 4. It highlights the Xenon bubbles more clearly. It appears that the largest bubbles are located mainly near dislocations

Detection of lipoid tumors by xenon-133

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

Kim, E.E.; DeLand, F.H.; Maruyama, Y.

1978-01-01

Three patients with biopsy-proven liposarcoma were studied with inhalation of xenon-133, a gas highly soluble in fat. Increased concentration of radioactivity in the region of the tumor suggested the potential usefulness of radioxenon for the detection of lipomatous tumors.

Xenon fluorides show potential as fluorinating agents

NASA Technical Reports Server (NTRS)

Chernick, C. L.; Shieh, T. C.; Yang, N. C.

1967-01-01

Xenon fluorides permit the controlled addition of fluorine across an olefinic double bond. They provide a series of fluorinating agents that permit ready separation from the product at a high purity. The reactions may be carried out in the vapor phase.

The Modification and Performance of a Large Animal Anesthesia Machine (Tafonius®) in Order to Deliver Xenon to a Horse.

PubMed

Santangelo, Bruna; Robin, Astrid; Simpson, Keith; Potier, Julie; Guichardant, Michel; Portier, Karine

2017-01-01

Xenon, due to its interesting anesthetic properties, could improve the quality of anesthesia protocols in horses despite its high price. This study aimed to modify and test an anesthesia machine capable of delivering xenon to a horse. An equine anesthesia machine (Tafonius, Vetronic Services Ltd., UK) was modified by including a T-connector in the valve block to introduce xenon, so that the xenon was pushed into the machine cylinder by the expired gases. A xenon analyzer was connected to the expiratory limb of the patient circuit. The operation of the machine was modeled and experimentally tested for denitrogenation, wash-in, and maintenance phases. The system was considered to consist of two compartments, one being the horse's lungs, the other being the machine cylinder and circuit. A 15-year-old, 514-kg, healthy gelding horse was anesthetized for 70 min using acepromazine, romifidine, morphine, diazepam, and ketamine. Anesthesia was maintained with xenon and oxygen, co-administered with lidocaine. Ventilation was controlled. Cardiorespiratory variables, expired fraction of xenon (FeXe), blood gases were measured and xenon was detected in plasma. Recovery was unassisted and recorded. FeXe remained around 65%, using a xenon total volume of 250 L. Five additional boli of ketamine were required to maintain anesthesia. PaO 2 was 45 ± 1 mmHg. The recovery was calm. Xenon was detected in blood during the entire administration time. This pilot study describes how to deliver xenon to a horse. Although many technical problems were encountered, their correction could guide future endeavors to study the use of xenon in horses.

Xenon is an inhibitor of tissue-plasminogen activator: adverse and beneficial effects in a rat model of thromboembolic stroke

PubMed Central

David, Hélène N; Haelewyn, Benoît; Risso, Jean-Jacques; Colloc'h, Nathalie; Abraini, Jacques H

2010-01-01

Preclinical evidence in rodents has proven that xenon may be a very promising neuroprotective agent for treating acute ischemic stroke. This has led to the general thinking that clinical trials with xenon could be initiated in acute stroke patients in a next future. However, an unappreciated physicochemical property of xenon has been that this gas also binds to the active site of a series of serine proteases. Because the active site of serine proteases is structurally conserved, we have hypothesized and investigated whether xenon may alter the catalytic efficiency of tissue-type plasminogen activator (tPA), a serine protease that is the only approved therapy for acute ischemic stroke today. Here, using molecular modeling and in vitro and in vivo studies, we show (1) xenon is a tPA inhibitor; (2) intraischemic xenon dose dependently inhibits tPA-induced thrombolysis and subsequent reduction of ischemic brain damage; (3) postischemic xenon virtually suppresses ischemic brain damage and tPA-induced brain hemorrhages and disruption of the blood–brain barrier. Taken together, these data indicate (1) xenon should not be administered before or together with tPA therapy; (2) xenon could be a golden standard for treating acute ischemic stroke if given after tPA-induced reperfusion, with both unique neuroprotective and antiproteolytic (anti-hemorrhaging) properties. PMID:20087367

Xenon does not increase heart rate-corrected cardiac QT interval in volunteers and in patients free of cardiovascular disease.

PubMed

Neukirchen, Martin; Schaefer, Maximilian S; Kern, Carolin; Brett, Sarah; Werdehausen, Robert; Rellecke, Philipp; Reyle-Hahn, Matthias; Kienbaum, Peter

2015-09-01

Impaired cardiac repolarization, indicated by prolonged QT interval, may cause critical ventricular arrhythmias. Many anesthetics increase the QT interval by blockade of rapidly acting potassium rectifier channels. Although xenon does not affect these channels in isolated cardiomyocytes, the authors hypothesized that xenon increases the QT interval by direct and/or indirect sympathomimetic effects. Thus, the authors tested the hypothesis that xenon alters the heart rate-corrected cardiac QT (QTc) interval in anesthetic concentrations. The effect of xenon on the QTc interval was evaluated in eight healthy volunteers and in 35 patients undergoing abdominal or trauma surgery. The QTc interval was recorded on subjects in awake state, after their denitrogenation, and during xenon monoanesthesia (FetXe > 0.65). In patients, the QTc interval was recorded while awake, after anesthesia induction with propofol and remifentanil, and during steady state of xenon/remifentanil anesthesia (FetXe > 0.65). The QTc interval was determined from three consecutive cardiac intervals on electrocardiogram printouts in a blinded manner and corrected with Bazett formula. In healthy volunteers, xenon did not alter the QTc interval (mean difference: +0.11 ms [95% CI, -22.4 to 22.7]). In patients, after anesthesia induction with propofol/remifentanil, no alteration of QTc interval was noted. After propofol was replaced with xenon, the QTc interval remained unaffected (417 ± 32 ms vs. awake: 414 ± 25 ms) with a mean difference of 4.4 ms (95% CI, -4.6 to 13.5). Xenon monoanesthesia in healthy volunteers and xenon/remifentanil anesthesia in patients without clinically relevant cardiovascular disease do not increase QTc interval.

Nuclear Spin Attenuates the Anesthetic Potency of Xenon Isotopes in Mice: Implications for the Mechanisms of Anesthesia and Consciousness.

PubMed

Li, Na; Lu, Dongshi; Yang, Lei; Tao, Huan; Xu, Younian; Wang, Chenchen; Fu, Lisha; Liu, Hui; Chummum, Yatisha; Zhang, Shihai

2018-04-11

Xenon is an elemental anesthetic with nine stable isotopes. Nuclear spin is a quantum property which may differ among isotopes. Xenon 131 (Xe) has nuclear spin of 3/2, xenon 129 (Xe) a nuclear spin of 1/2, and the other seven isotopes have no nuclear spin. This study was aimed to explore the effect of nuclear spin on xenon anesthetic potency. Eighty C57BL/6 male mice (7 weeks old) were randomly divided into four groups, xenon 132 (Xe), xenon 134 (Xe), Xe, and Xe groups. Due to xenon's low potency, loss of righting reflex ED50 for mice to xenon was determined with 0.50% isoflurane. Loss of righting reflex ED50 of isoflurane was also measured, and the loss of righting reflex ED50 values of the four xenon isotopes were then calculated. The exact polarizabilities of the isotopes were calculated. Combined with 0.50% isoflurane, the loss of righting reflex ED50 values were 15 ± 4%, 16 ± 5%, 22 ± 5%, and 23 ± 7% for Xe, Xe, Xe, and Xe, respectively. For xenon alone, the loss of righting reflex ED50 values of Xe, Xe, Xe, and Xe were 70 ± 4%, 72 ± 5%, 99 ± 5%, and 105 ± 7%, respectively. Four isotopes had a same exact polarizability of 3.60 Å. Xenon isotopes with nuclear spin are less potent than those without, and polarizability cannot account for the difference. The lower anesthetic potency of Xe may be the result of it participating in conscious processing and therefore partially antagonizing its own anesthetic potency. Nuclear spin is a quantum property, and our results are consistent with theories that implicate quantum mechanisms in consciousness.

Xenon isotopic composition of the Mid Ocean Ridge Basalt (MORB) source

NASA Astrophysics Data System (ADS)

Peto, M. K.; Mukhopadhyay, S.

2012-12-01

Although convection models do not preclude preservation of smaller mantle regions with more pristine composition throughout Earth's history, it has been widely assumed that the moon forming giant impact likely homogenizes the whole mantle following a magma ocean that extended all the way to the bottom of the mantle. Recent findings of tungsten and xenon heterogeneities in the mantle [1,2,3,4], however, imply that i) the moon forming giant impact may not have homogenized the whole mantle and ii) plate tectonics was inefficient in erasing early formed compositional differences, particularly for the xenon isotopes. Therefore, the xenon isotope composition in the present day mantle still preserves a memory of early Earth processes. However, determination of the xenon isotopic composition of the mantle source is still scarce, since the mantle composition is overprinted by post-eruptive atmospheric contamination in basalts erupted at ocean islands and mid ocean ridges. The xenon composition of the depleted upper mantle has been defined by the gas rich sample, 2πD43 (also known as "popping rock"), from the North Atlantic (13° 469`N). However, the composition of a single sample is not likely to define the composition of the upper mantle, especially since popping rock has an "enriched" trace element composition. We will present Ne, Ar and Xe isotope data on MORB glass samples with "normal" helium isotope composition (8±1 Ra) from the Southeast Indian Ridge, the South Atlantic Ridge, the Sojourn Ridge, the Juan de Fuca, the East Pacific Rise, and the Gakkel Ridge. Following the approach of [1], we correct for syn- and post-eruptive atmosphere contamination, and determine the variation of Ar and Xe isotope composition of the "normal" MORB source. We investigate the effect of atmospheric recycling in the variation of MORB mantle 40Ar/36Ar and 129Xe/130Xe ratios, and attempt to constrain the average upper mantle argon and xenon isotopic compositions. [1] Mukhopadhyay, Nature

Diffusion NMR methods applied to xenon gas for materials study

NASA Technical Reports Server (NTRS)

Mair, R. W.; Rosen, M. S.; Wang, R.; Cory, D. G.; Walsworth, R. L.

2002-01-01

We report initial NMR studies of (i) xenon gas diffusion in model heterogeneous porous media and (ii) continuous flow laser-polarized xenon gas. Both areas utilize the pulsed gradient spin-echo (PGSE) techniques in the gas phase, with the aim of obtaining more sophisticated information than just translational self-diffusion coefficients--a brief overview of this area is provided in the Introduction. The heterogeneous or multiple-length scale model porous media consisted of random packs of mixed glass beads of two different sizes. We focus on observing the approach of the time-dependent gas diffusion coefficient, D(t) (an indicator of mean squared displacement), to the long-time asymptote, with the aim of understanding the long-length scale structural information that may be derived from a heterogeneous porous system. We find that D(t) of imbibed xenon gas at short diffusion times is similar for the mixed bead pack and a pack of the smaller sized beads alone, hence reflecting the pore surface area to volume ratio of the smaller bead sample. The approach of D(t) to the long-time limit follows that of a pack of the larger sized beads alone, although the limiting D(t) for the mixed bead pack is lower, reflecting the lower porosity of the sample compared to that of a pack of mono-sized glass beads. The Pade approximation is used to interpolate D(t) data between the short- and long-time limits. Initial studies of continuous flow laser-polarized xenon gas demonstrate velocity-sensitive imaging of much higher flows than can generally be obtained with liquids (20-200 mm s-1). Gas velocity imaging is, however, found to be limited to a resolution of about 1 mm s-1 owing to the high diffusivity of gases compared with liquids. We also present the first gas-phase NMR scattering, or diffusive-diffraction, data, namely flow-enhanced structural features in the echo attenuation data from laser-polarized xenon flowing through a 2 mm glass bead pack. c2002 John Wiley & Sons, Ltd.

Micro124-mediated AHR expression regulates the inflammatory response of chronic rhinosinusitis (CRS) with nasal polyps.

PubMed

Liu, C C; Xia, M; Zhang, Y J; Jin, P; Zhao, L; Zhang, J; Li, T; Zhou, X M; Tu, Y Y; Kong, F; Sun, C; Shi, L; Zhao, M Q

2018-06-02

MicroRNAs represent a component of the innate immune responses that can restrain inflammatory signaling, miR124 is an important member of inflammation-associated miRNAs, and abnormal miR124 expression is observed in many inflammatory diseases and immune disorders. However, the role and signaling pathways of miR124 in chronic rhinosinusitis with nasal polyps (CRSwNPs) have not been studied in detail. The aryl hydrocarbon receptor (AHR) is a ligand-inducible transcription factor that is highly conserved in evolution and plays important roles in the inflammatory response process. In our study, we describe the role of miR124 in the inflammatory response of CRS with nasal polyps. We found that the expression of miR124 was decreased in nasal polyps, and negatively correlated with the expression of AHR. MiR124 can inhibit AHR expression by directly target 3' untranslated region (3'-UTR) of AHR. To further investigate the relationship between miR124, AHR and CRS inflammatory response, we transfect HNEpC cells with miR124 mimic, miR124 inhibitors or siRNA of AHR, then all the results showed that miR124 could regulates cellular inflammatory response through negatively regulating AHR expression. This study demonstrated that the regulation of AHR expression by miR124 is critical to the development of inflammatory response in CRSwNPs. Copyright © 2018. Published by Elsevier Inc.

STS-124 and Expedition 17 crew portrait

NASA Image and Video Library

2008-06-09

S124-E-007905 (9 June 2008) --- The STS-124 and Expedition 17 crewmembers pose for a group portrait following a joint news conference from the newly installed Kibo Japanese Pressurized Module of the International Space Station while Space Shuttle Discovery is docked with the station. From the left (front row) are NASA astronauts Karen Nyberg, Garrett Reisman, both STS-124 mission specialists; Mark Kelly, STS-124 commander; Russian Federal Space Agency cosmonaut Sergei Volkov, Expedition 17 commander; and NASA astronaut Mike Fossum, STS-124 mission specialist. From the left (back row) are NASA astronaut Ron Garan, STS-124 mission specialist; Russian Federal Space Agency cosmonaut Oleg Kononenko, Expedition 17 flight engineer; NASA astronauts Ken Ham, STS-124 pilot; Greg Chamitoff, Expedition 17 flight engineer; and Japan Aerospace Exploration Agency astronaut Akihiko Hoshide, STS-124 mission specialist. Reisman, who joined the station's crew in March, is being replaced by Chamitoff, who arrived at the station with the STS-124 crew.

Search for bosonic super-WIMP interactions with the XENON100 experiment

NASA Astrophysics Data System (ADS)

Aprile, E.; Aalbers, J.; Agostini, F.; Alfonsi, M.; Althueser, L.; Amaro, F. D.; Anthony, M.; Arneodo, F.; Barrow, P.; Baudis, L.; Bauermeister, B.; Benabderrahmane, M. L.; Berger, T.; Breur, P. A.; Brown, A.; Brown, A.; Brown, E.; Bruenner, S.; Bruno, G.; Budnik, R.; Bütikofer, L.; Calvén, J.; Capelli, C.; Cardoso, J. M. R.; Cichon, D.; Coderre, D.; Colijn, A. P.; Conrad, J.; Cussonneau, J. P.; Decowski, M. P.; de Perio, P.; di Gangi, P.; di Giovanni, A.; Diglio, S.; Eurin, G.; Fei, J.; Ferella, A. D.; Fieguth, A.; Fulgione, W.; Gallo Rosso, A.; Galloway, M.; Gao, F.; Garbini, M.; Geis, C.; Goetzke, L. W.; Greene, Z.; Grignon, C.; Hasterok, C.; Hogenbirk, E.; Howlett, J.; Itay, R.; Kaminsky, B.; Kazama, S.; Kessler, G.; Kish, A.; Landsman, H.; Lang, R. F.; Lellouch, D.; Levinson, L.; Lin, Q.; Lindemann, S.; Lindner, M.; Lombardi, F.; Lopes, J. A. M.; Manfredini, A.; Maris, I.; Marrodán Undagoitia, T.; Masbou, J.; Massoli, F. V.; Masson, D.; Mayani, D.; Messina, M.; Micheneau, K.; Molinario, A.; Morâ, K.; Murra, M.; Naganoma, J.; Ni, K.; Oberlack, U.; Pakarha, P.; Pelssers, B.; Persiani, R.; Piastra, F.; Pienaar, J.; Pizzella, V.; Piro, M.-C.; Plante, G.; Priel, N.; Ramírez García, D.; Rauch, L.; Reichard, S.; Reuter, C.; Rizzo, A.; Rupp, N.; Dos Santos, J. M. F.; Sartorelli, G.; Scheibelhut, M.; Schindler, S.; Schreiner, J.; Schumann, M.; Scotto Lavina, L.; Selvi, M.; Shagin, P.; Silva, M.; Simgen, H.; Sivers, M. V.; Stein, A.; Thers, D.; Tiseni, A.; Trinchero, G.; Tunnell, C.; Vargas, M.; Wang, H.; Wang, Z.; Wei, Y.; Weinheimer, C.; Wittweg, C.; Wulf, J.; Ye, J.; Zhang, Y.; Zhu, T.; Xenon Collaboration

2017-12-01

We present results of searches for vector and pseudoscalar bosonic super-weakly interacting massive particles (WIMPs), which are dark matter candidates with masses at the keV-scale, with the XENON100 experiment. XENON100 is a dual-phase xenon time projection chamber operated at the Laboratori Nazionali del Gran Sasso. A profile likelihood analysis of data with an exposure of 224.6 live days ×34 kg showed no evidence for a signal above the expected background. We thus obtain new and stringent upper limits in the (8 - 125 ) keV /c2 mass range, excluding couplings to electrons with coupling constants of ga e>3 ×10-13 for pseudo-scalar and α'/α >2 ×10-28 for vector super-WIMPs, respectively. These limits are derived under the assumption that super-WIMPs constitute all of the dark matter in our galaxy.

Extreme Confinement of Xenon by Cryptophane-111 in the Solid State

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

Joseph, Akil I.; Lapidus, Saul H.; Kane, Christopher M.

2014-12-11

Solids that sorb, capture and/or store the heavier noble gases are of interest because of their potential for transformative rare gas separation/production, storage, or recovery technologies. Herein, we report the isolation, crystal structures, and thermal stabilities of a series of xenon and krypton clathrates of (±)-cryptophane-111 (111). One trigonal crystal form, Xe@111•y(solvent), is exceptionally stable, retaining xenon at temperatures of up to about 300 °C. The high kinetic stability is attributable not only to the high xenon affinity and cage-like nature of the host, but also to the crystal packing of the clathrate, wherein each window of the molecular containermore » is blocked by the bridges of adjacent containers, effectively imprisoning the noble gas in the solid state. The results highlight the potential of discrete molecule materials exhibiting intrinsic microcavities or zero-dimensional pores.« less

MicroRNA-124 Controls the Proliferative, Migratory, and Inflammatory Phenotype of Pulmonary Vascular Fibroblasts

PubMed Central

Wang, Daren; Zhang, Zhang; Li, Min; Frid, Maria G.; Flockton, Amanda R.; McKeon, B. Alexandre; Yeager, Michael E.; Fini, Mehdi A.; Morrell, Nicholas W.; Pullamsetti, Soni S.; Velegala, Sivareddy; Seeger, Werner; McKinsey, Timothy A.; Sucharov, Carmen C.; Stenmark, Kurt R.

2014-01-01

Rationale Pulmonary hypertensive remodeling is characterized by excessive proliferation, migration, and proinflammatory activation of adventitial fibroblasts. In culture, fibroblasts maintain a similar activated phenotype. The mechanisms responsible for generation/maintenance of this phenotype remain unknown. Objective We hypothesized that aberrant expression of microRNA-124 (miR-124) regulates this activated fibroblast phenotype and sought to determine the signaling pathways through which miR-124 exerts effects. Methods and Results We detected significant decreases in miR-124 expression in fibroblasts isolated from calves and humans with severe pulmonary hypertension. Overexpression of miR-124 by mimic transfection significantly attenuated proliferation, migration, and monocyte chemotactic protein-1 expression of hypertensive fibroblasts, whereas anti–miR-124 treatment of control fibroblasts resulted in their increased proliferation, migration, and monocyte chemotactic protein-1 expression. Furthermore, the alternative splicing factor, polypyrimidine tract–binding protein 1, was shown to be a direct target of miR-124 and to be upregulated both in vivo and in vitro in bovine and human pulmonary hypertensive fibroblasts. The effects of miR-124 on fibroblast proliferation were mediated via direct binding to the 3′ untranslated region of polypyrimidine tract–binding protein 1 and subsequent regulation of Notch1/phosphatase and tensin homolog/FOXO3/p21Cip1 and p27Kip1 signaling. We showed that miR-124 directly regulates monocyte chemotactic protein-1 expression in pulmonary hypertension/idiopathic pulmonary arterial hypertension fibroblasts. Furthermore, we demonstrated that miR-124 expression is suppressed by histone deacetylases and that treatment of hypertensive fibroblasts with histone deacetylase inhibitors increased miR-124 expression and decreased proliferation and monocyte chemotactic protein-1 production. Conclusions Stable decreases in miR-124

Stirring Up an Elastic Fluid: Critical Viscosity of Xenon-2 (CVX-2)

NASA Astrophysics Data System (ADS)

Berg, Robert F.; Moldover, Michael R.; Zimmerli, Gregory A.

2002-12-01

Whipped cream stays in place even when turned upside down. Yet it readily flows through the nozzle of a spray can to reach the dessert plate. This demonstrates the phenomenon of shear thinning that is important to many industrial and physical processes. Paints, film emulsions, and other complex solutions that are highly viscous under normal conditions but become thin and flow easily under shear forces. A simple fluid, such as water, does not exhibit shear thinning under normal conditions. Very close to the liquid-vapor critical point, where the distinction between liquid and vapor disappears, the fluid becomes more complex and is predicted to display shear thinning. At the critical point, xenon atoms interact over long distances in a classical model of cooperative phenomena. Physicists rely on this system to learn how long-range order arises. The Critical Viscosity of Xenon Experiment (CVX-2) will measure the viscous behavior of xenon, a heavy inert gas used in flash lamps and ion rocket engines, at its critical point. Although it does not easily combine with other chemicals, its viscosity at the critical point can be used as a model for a range of fluids. Viscosity originates from the interactions of individual molecules. It is so complicated that, except for the simplest gas, it cannot be calculated accurately from theory. Tests with critical fluids can provide key data, but are limited on Earth because critical fluids are highly compressed by gravity. CVX-2 employs a tiny metal screen vibrating between two electrodes in a bath of critical xenon. The vibrations and how they dampen are used to measure viscosity. CVX flew on STS-85 (1997), where it revealed that, close to the critical point, the xenon is partly elastic: it can 'stretch' as well as flow. For STS-107, the hardware has been enhanced to determine if critical xenon is a shear-thinning fluid.

Stirring Up an Elastic Fluid: Critical Viscosity of Xenon-2 (CVX-2)

NASA Technical Reports Server (NTRS)

Berg, Robert F.; Moldover, Michael R.; Zimmerli, Gregory A.; Motil, Susan M. (Technical Monitor)

2002-01-01

Whipped cream stays in place even when turned upside down. Yet it readily flows through the nozzle of a spray can to reach the dessert plate. This demonstrates the phenomenon of shear thinning that is important to many industrial and physical processes. Paints, film emulsions, and other complex solutions that are highly viscous under normal conditions but become thin and flow easily under shear forces. A simple fluid, such as water, does not exhibit shear thinning under normal conditions. Very close to the liquid-vapor critical point, where the distinction between liquid and vapor disappears, the fluid becomes more complex and is predicted to display shear thinning. At the critical point, xenon atoms interact over long distances in a classical model of cooperative phenomena. Physicists rely on this system to learn how long-range order arises. The Critical Viscosity of Xenon Experiment (CVX-2) will measure the viscous behavior of xenon, a heavy inert gas used in flash lamps and ion rocket engines, at its critical point. Although it does not easily combine with other chemicals, its viscosity at the critical point can be used as a model for a range of fluids. Viscosity originates from the interactions of individual molecules. It is so complicated that, except for the simplest gas, it cannot be calculated accurately from theory. Tests with critical fluids can provide key data, but are limited on Earth because critical fluids are highly compressed by gravity. CVX-2 employs a tiny metal screen vibrating between two electrodes in a bath of critical xenon. The vibrations and how they dampen are used to measure viscosity. CVX flew on STS-85 (1997), where it revealed that, close to the critical point, the xenon is partly elastic: it can 'stretch' as well as flow. For STS-107, the hardware has been enhanced to determine if critical xenon is a shear-thinning fluid.

Timing of xenon-induced delayed postconditioning to protect against spinal cord ischaemia-reperfusion injury in rats.

PubMed

Yang, Y W; Cheng, W P; Lu, J K; Dong, X H; Wang, C B; Zhang, J; Zhao, L Y; Gao, Z F

2014-07-01

This study was designed to assess the neuroprotective effect of xenon-induced delayed postconditioning on spinal cord ischaemia-reperfusion injury (IRI) and to determine the time of administration for best neuroprotection in a rat model of spinal cord IRI. Fifty male rats were randomly divided equally into a sham group, control group, and three xenon postconditioning groups (n=10 per group). The control group underwent spinal cord IRI and immediately inhaled 50% nitrogen/50% oxygen for 3 h at the initiation of reperfusion. The three xenon postconditioning groups underwent the same surgical procedure and immediately inhaled 50% xenon/50% oxygen for 3 h at the initiation of reperfusion or 1 and 2 h after reperfusion. The sham operation group underwent the same surgical procedure without aortic occlusion, and inhaled 50% nitrogen/50% oxygen. Neurological function was assessed using the Basso, Beattie, and Bresnahan score at 4, 24, and 48 h of reperfusion. Histological examination was performed using Nissl staining and immunohistochemistry, and apoptosis was detected by terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick end-labelling staining. Compared with the control group, the three xenon postconditioning groups showed improvements in neurological outcomes, and had more morphologically normal neurones at 48 h of reperfusion. Apoptotic cell death was reduced and the ratio of Bcl-2/Bax immunoreactivity increased in xenon-treated rats compared with controls. Xenon postconditioning up to 2 h after reperfusion provided protection against spinal cord IRI in rats, but the greatest neuroprotection occurred with administration of xenon for 1 h at reperfusion. © The Author [2013]. Published by Oxford University Press on behalf of the British Journal of Anaesthesia. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Renal function following xenon anesthesia for partial nephrectomy-An explorative analysis of a randomized controlled study.

PubMed

Stevanovic, Ana; Schaefer, Patrick; Coburn, Mark; Rossaint, Rolf; Stoppe, Christian; Boor, Peter; Pfister, David; Heidenreich, Axel; Christ, Hildegard; Hellmich, Martin; Fahlenkamp, Astrid V

2017-01-01

Perioperative preservation of renal function has a significant impact on morbidity and mortality in kidney surgery. Nephroprotective effects of the anesthetic xenon on ischemia-reperfusion injury were found in several experimental studies. We aimed to explore whether xenon anesthesia can reduce renal damage in humans undergoing partial nephrectomy and to gather pilot data of possible nephroprotection in these patients. A prospective randomized, single-blinded, controlled study. Single-center, University Hospital of Aachen, Germany between July 2013-October 2015. Forty-six patients with regular renal function undergoing partial nephrectomy. Patients were randomly assigned to receive xenon- (n = 23) or isoflurane (n = 23) anesthesia. Primary outcome was the maximum postoperative glomerular filtration rate (GFR) decline within seven days after surgery. Secondary outcomes included intraoperative and tumor-related data, assessment of further kidney injury markers, adverse events and optional determination of renal function after 3-6 months. Unexpected radical nephrectomy was performed in 5 patients, thus they were excluded from the per-protocol analysis, but included in the intention-to-treat analysis. The maximum postoperative GFR decline was attenuated by 45% in the xenon-group (10.9 ml min-1 1.73 cm-2 versus 19.7 ml min-1 1.73 cm-2 in the isoflurane group), but without significance (P = 0.084). Occurrence of adverse events was reduced (P = 0.003) in the xenon group. Renal function was similar among the groups after 3-6 months. Xenon anesthesia was feasible and safe in patients undergoing partial nephrectomy with regard to postoperative renal function. We found no significant effect on early renal function but less adverse events in the xenon group. Larger randomized controlled studies in more heterogeneous collectives are required, to confirm or refute the possible clinical benefit on renal function by xenon. ClinicalTrials.gov NCT01839084 and EudraCT 2012-005698-30.

Xenon adsorption on geological media and implications for radionuclide signatures.

PubMed

Paul, M J; Biegalski, S R; Haas, D A; Jiang, H; Daigle, H; Lowrey, J D

2018-07-01

The detection of radioactive noble gases is a primary technology for verifying compliance with the pending Comprehensive Nuclear-Test-Ban Treaty. A fundamental challenge in applying this technology for detecting underground nuclear explosions is estimating the timing and magnitude of the radionuclide signatures. While the primary mechanism for transport is advective transport, either through barometric pumping or thermally driven advection, diffusive transport in the surrounding matrix also plays a secondary role. From the study of primordial noble gas signatures, it is known that xenon has a strong physical adsorption affinity in shale formations. Given the unselective nature of physical adsorption, isotherm measurements reported here show that non-trivial amounts of xenon adsorb on a variety of media, in addition to shale. A dual-porosity model is then discussed demonstrating that sorption amplifies the diffusive uptake of an adsorbing matrix from a fracture. This effect may reduce the radioxenon signature down to approximately one-tenth, similar to primordial xenon isotopic signatures. Copyright © 2018 Elsevier Ltd. All rights reserved.

Isotopic signature of atmospheric xenon released from light water reactors.

PubMed

Kalinowski, Martin B; Pistner, Christoph

2006-01-01

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

XENON100 exclusion limit without considering Leff as a nuisance parameter

NASA Astrophysics Data System (ADS)

Davis, Jonathan H.; Bœhm, Céline; Oppermann, Niels; Ensslin, Torsten; Lacroix, Thomas

2012-07-01

In 2011, the XENON100 experiment has set unprecedented constraints on dark matter-nucleon interactions, excluding dark matter candidates with masses down to 6 GeV if the corresponding cross section is larger than 10-39cm2. The dependence of the exclusion limit in terms of the scintillation efficiency (Leff) has been debated at length. To overcome possible criticisms XENON100 performed an analysis in which Leff was considered as a nuisance parameter and its uncertainties were profiled out by using a Gaussian likelihood in which the mean value corresponds to the best fit Leff value (smoothly extrapolated to 0 below 3 keVnr). Although such a method seems fairly robust, it does not account for more extreme types of extrapolation nor does it enable us to anticipate how much the exclusion limit would vary if new data were to support a flat behavior for Leff below 3 keVnr, for example. Yet, such a question is crucial for light dark matter models which are close to the published XENON100 limit. To answer this issue, we use a maximum likelihood ratio analysis, as done by the XENON100 Collaboration, but do not consider Leff as a nuisance parameter. Instead, Leff is obtained directly from the fits to the data. This enables us to define frequentist confidence intervals by marginalizing over Leff.

Measurement of xenon plasma properties in an ion thruster using laser Thomson scattering technique

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

Yamamoto, N.; Tomita, K.; Sugita, K.

2012-07-15

This paper reports on the development of a method for measuring xenon plasma properties using the laser Thomson scattering technique, for application to ion engine system design. The thresholds of photo-ionization of xenon plasma were investigated and the number density of metastable atoms, which are photo-ionized by a probe laser, was measured using laser absorption spectroscopy, for several conditions. The measured threshold energy of the probe laser using a plano-convex lens with a focal length of 200 mm was 150 mJ for a xenon mass flow rate of 20 {mu}g/s and incident microwave power of 6 W; the probe lasermore » energy was therefore set as 80 mJ. Electron number density was found to be (6.2 {+-} 0.4) Multiplication-Sign 10{sup 17} m{sup -3} and electron temperature was found to be 2.2 {+-} 0.4 eV at a xenon mass flow rate of 20 {mu}g/s and incident microwave power of 6 W. The threshold of the probe laser intensity against photo-ionization in a miniature xenon ion thruster is almost constant for various mass flow rates, since the ratio of population of the metastable atoms to the electron number density is little changed.« less

Shear Thinning in Xenon

NASA Technical Reports Server (NTRS)

Bergm Robert F.; Moldover, Michael R.; Yao, Minwu; Zimmerli, Gregory A.

2009-01-01

We measured shear thinning, a viscosity decrease ordinarily associated with complex liquids such as molten plastics or ketchup, near the critical point of xenon. The data span a wide range of dimensionless shear rate: the product of the shear rate and the relaxation time of critical fluctuations was greater than 0.001 and was less than 700. As predicted by theory, shear thinning occurred when this product was greater than 1. The measurements were conducted aboard the Space Shuttle Columbia to avoid the density stratification caused by Earth's gravity.

Neutrino physics with multi-ton scale liquid xenon detectors

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

Baudis, L.; Ferella, A.; Kish, A.

2014-01-01

We study the sensitivity of large-scale xenon detectors to low-energy solar neutrinos, to coherent neutrino-nucleus scattering and to neutrinoless double beta decay. As a concrete example, we consider the xenon part of the proposed DARWIN (Dark Matter WIMP Search with Noble Liquids) experiment. We perform detailed Monte Carlo simulations of the expected backgrounds, considering realistic energy resolutions and thresholds in the detector. In a low-energy window of 2–30 keV, where the sensitivity to solar pp and {sup 7}Be-neutrinos is highest, an integrated pp-neutrino rate of 5900 events can be reached in a fiducial mass of 14 tons of natural xenon,more » after 5 years of data. The pp-neutrino flux could thus be measured with a statistical uncertainty around 1%, reaching the precision of solar model predictions. These low-energy solar neutrinos will be the limiting background to the dark matter search channel for WIMP-nucleon cross sections below ∼ 2 × 10{sup −48} cm{sup 2} and WIMP masses around 50 GeV⋅c{sup −2}, for an assumed 99.5% rejection of electronic recoils due to elastic neutrino-electron scatters. Nuclear recoils from coherent scattering of solar neutrinos will limit the sensitivity to WIMP masses below ∼ 6 GeV⋅c{sup −2} to cross sections above ∼ 4 × 10{sup −45}cm{sup 2}. DARWIN could reach a competitive half-life sensitivity of 5.6 × 10{sup 26} y to the neutrinoless double beta decay of {sup 136}Xe after 5 years of data, using 6 tons of natural xenon in the central detector region.« less

Near-infrared scintillation of xenon by 63Ni beta decay

NASA Astrophysics Data System (ADS)

Yoshimizu, Norimasa; Lal, Amit; Pollock, Clifford R.

2006-07-01

The near-infrared scintillation of xenon gas by the β decay of 37MBq of Ni63 was studied, in the interest of its use in integrated devices for applications such as optical beacons and wavelength calibration. The emission was imaged and analyzed using Spencer's theory of electron penetration using xenon scattering cross sections derived from Thomas-Fermi theory. The total emission was approximately 2×105photons/s at 20kPa and 1×105photons/s at 100kPa. Spectral data show three dominant peaks at 823, 828, and 882nm as well as the formation of metastable states.

First-principles calculation of the reflectance of shock-compressed xenon

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

Norman, G. E.; Saitov, I. M., E-mail: saitovilnur@gmail.com; Stegailov, V. V.

2015-05-15

Within electron density functional theory (DFT), the reflectance of radiation from shock-compressed xenon plasma is calculated. The dependence of the reflectance on the frequency of the incident radiation and on the plasma density is considered. The Fresnel formula is used. The expression for the longitudinal dielectric tensor in the long-wavelength limit is used to calculate the imaginary part of the dielectric function (DF). The real part of the DF is determined by the Kramers-Kronig transformation. The results are compared with experimental data. An approach is proposed to estimate the plasma frequency in shock-compressed xenon.

42 CFR 124.510 - Record maintenance requirements.

Code of Federal Regulations, 2011 CFR

2011-10-01

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42 CFR 124.510 - Record maintenance requirements.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 42 Public Health 1 2010-10-01 2010-10-01 false Record maintenance requirements. 124.510 Section 124.510 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES HEALTH RESOURCES... Persons Unable To Pay § 124.510 Record maintenance requirements. (a) Facilities not certified under § 124...

42 CFR 124.8 - Grantee accountability.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 42 Public Health 1 2010-10-01 2010-10-01 false Grantee accountability. 124.8 Section 124.8 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES HEALTH RESOURCES DEVELOPMENT... and Modernization § 124.8 Grantee accountability. (a) Records requirements. (1) Applicants who have...

7 CFR 1260.124 - Consumer information.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 7 Agriculture 10 2011-01-01 2011-01-01 false Consumer information. 1260.124 Section 1260.124... Promotion and Research Order Definitions § 1260.124 Consumer information. Consumer information means nutritional data and other information that will assist consumers and other persons in making evaluations and...

Novel 1H-1,2,3-, 2H-1,2,3-, 1H-1,2,4- and 4H-1,2,4-triazole derivatives: a patent review (2008 - 2011).

PubMed

Ferreira, Vitor F; da Rocha, David R; da Silva, Fernando C; Ferreira, Patrícia G; Boechat, Núbia A; Magalhães, Jorge L

2013-03-01

The triazoles represent a class of five-membered heterocyclic compounds of great importance for the preparation of new drugs with diverse biological activities because they may present several structural variations with the same numbers of carbon and nitrogen atoms. Due to the success of various triazoles that entered the pharmaceutical market and are still being used in medicines, many companies and research groups have shown interest in developing new methods of synthesis and biological evaluation of potential uses for these compounds. In this review, the authors explored aspects of patents for the 1H-1,2,3-, 2H-1,2,3-, 1H-1,2,4- and 4H-1,2,4-triazole families, including prototypes being considered in clinical studies between 2008 and 2011. The triazoles have been studied for over a century as an important class of heterocyclic compounds and still attract considerable attention due to their broad range of biological activities. More recently, there has been considerable interest in the development of novel triazoles with anti-inflammatory, antiplatelet, antimicrobial, antimycobacterial, antitumoral and antiviral properties and activity against several neglected diseases. This review emphasizes recent perspective and advances in the therapeutically active 1H-1,2,3-, 2H-1,2,3-, 1H-1,2,4- and 4H-1,2,4-triazole derivative patents between 2008 and 2011, covering the development of new chemical entities and new pharmaceuticals. Many studies have focused on these compounds as target structures and evaluated them in several biological targets. The preparation of 1H-1,2,3-, 2H-1,2,3-, 1H-1,2,4- and 4H-1,2,4-triazole derivatives brings to light several issues. There is a need to find new, more efficient preparations for these triazoles that take into consideration current issues in green chemistry, energy saving and sustainability. New diseases are discovered and new viruses and bacteria continue to challenge mankind, so it is imperative to find new prototypes for these

Collateral Ventilation to Congenital Hyperlucent Lung Lesions Assessed on Xenon-Enhanced Dynamic Dual-Energy CT: an Initial Experience

PubMed Central

Yang, Dong Hyun; Kim, Namkug; Park, Seung Il; Kim, Dong Kwan; Kim, Ellen Ai-Rhan

2011-01-01

Objective We wanted to evaluate the resistance to collateral ventilation in congenital hyperlucent lung lesions and to correlate that with the anatomic findings on xenon-enhanced dynamic dual-energy CT. Materials and Methods Xenon-enhanced dynamic dual-energy CT was successfully and safely performed in eight children (median age: 5.5 years, 4 boys and 4 girls) with congenital hyperlucent lung lesions. Functional assessment of the lung lesions on the xenon map was done, including performing a time-xenon value curve analysis and assessing the amplitude of xenon enhancement (A) value, the rate of xenon enhancement (K) value and the time of arrival value. Based on the A value, the lung lesions were categorized into high or low (A value > 10 Hounsfield unit [HU]) resistance to collateral ventilation. In addition, the morphologic CT findings of the lung lesions, including cyst, mucocele and an accessory or incomplete fissure, were assessed on the weighted-average CT images. The xenon-enhanced CT radiation dose was estimated. Results Five of the eight lung lesions were categorized into the high resistance group and three lesions were categorized into the low resistance group. The A and K values in the normal lung were higher than those in the low resistance group. The time of arrival values were delayed in the low resistance group. Cysts were identified in five lesions, mucocele in four, accessory fissure in three and incomplete fissure in two. Either cyst or an accessory fissure was seen in four of the five lesions showing high resistance to collateral ventilation. The xenon-enhanced CT radiation dose was 2.3 ± 0.6 mSv. Conclusion Xenon-enhanced dynamic dual-energy CT can help visualize and quantitate various degrees of collateral ventilation to congenital hyperlucent lung lesions in addition to assessing the anatomic details of the lung. PMID:21228937

Collateral ventilation to congenital hyperlucent lung lesions assessed on xenon-enhanced dynamic dual-energy CT: an initial experience.

PubMed

Goo, Hyun Woo; Yang, Dong Hyun; Kim, Namkug; Park, Seung Il; Kim, Dong Kwan; Kim, Ellen Ai-Rhan

2011-01-01

We wanted to evaluate the resistance to collateral ventilation in congenital hyperlucent lung lesions and to correlate that with the anatomic findings on xenon-enhanced dynamic dual-energy CT. Xenon-enhanced dynamic dual-energy CT was successfully and safely performed in eight children (median age: 5.5 years, 4 boys and 4 girls) with congenital hyperlucent lung lesions. Functional assessment of the lung lesions on the xenon map was done, including performing a time-xenon value curve analysis and assessing the amplitude of xenon enhancement (A) value, the rate of xenon enhancement (K) value and the time of arrival value. Based on the A value, the lung lesions were categorized into high or low (A value > 10 Hounsfield unit [HU]) resistance to collateral ventilation. In addition, the morphologic CT findings of the lung lesions, including cyst, mucocele and an accessory or incomplete fissure, were assessed on the weighted-average CT images. The xenon-enhanced CT radiation dose was estimated. Five of the eight lung lesions were categorized into the high resistance group and three lesions were categorized into the low resistance group. The A and K values in the normal lung were higher than those in the low resistance group. The time of arrival values were delayed in the low resistance group. Cysts were identified in five lesions, mucocele in four, accessory fissure in three and incomplete fissure in two. Either cyst or an accessory fissure was seen in four of the five lesions showing high resistance to collateral ventilation. The xenon-enhanced CT radiation dose was 2.3 ± 0.6 mSv. Xenon-enhanced dynamic dual-energy CT can help visualize and quantitate various degrees of collateral ventilation to congenital hyperlucent lung lesions in addition to assessing the anatomic details of the lung.

Chondritic xenon in the Earth’s mantle

NASA Astrophysics Data System (ADS)

Caracausi, Antonio; Avice, Guillaume; Burnard, Peter G.; Füri, Evelyn; Marty, Bernard

2016-05-01

Noble gas isotopes are powerful tracers of the origins of planetary volatiles, and the accretion and evolution of the Earth. The compositions of magmatic gases provide insights into the evolution of the Earth’s mantle and atmosphere. Despite recent analytical progress in the study of planetary materials and mantle-derived gases, the possible dual origin of the planetary gases in the mantle and the atmosphere remains unconstrained. Evidence relating to the relationship between the volatiles within our planet and the potential cosmochemical end-members is scarce. Here we show, using high-precision analysis of magmatic gas from the Eifel volcanic area (in Germany), that the light xenon isotopes identify a chondritic primordial component that differs from the precursor of atmospheric xenon. This is consistent with an asteroidal origin for the volatiles in the Earth’s mantle, and indicates that the volatiles in the atmosphere and mantle originated from distinct cosmochemical sources. Furthermore, our data are consistent with the origin of Eifel magmatism being a deep mantle plume. The corresponding mantle source has been isolated from the convective mantle since about 4.45 billion years ago, in agreement with models that predict the early isolation of mantle domains. Xenon isotope systematics support a clear distinction between mid-ocean-ridge and continental or oceanic plume sources, with chemical heterogeneities dating back to the Earth’s accretion. The deep reservoir now sampled by the Eifel gas had a lower volatile/refractory (iodine/plutonium) composition than the shallower mantle sampled by mid-ocean-ridge volcanism, highlighting the increasing contribution of volatile-rich material during the first tens of millions of years of terrestrial accretion.

Long non-coding RNA GAS5 aggravates hypoxia injury in PC-12 cells via down-regulating miR-124.

PubMed

Hu, Xiaoli; Liu, Juan; Zhao, Gang; Zheng, Jiaping; Qin, Xia

2018-05-08

One important feature of cerebral ischemia is hypoxia injury in nerve cells. Growth arrest-specific transcript 5 (GAS5) is widely reported as a tumor suppressor gene; however, the investigations about its role in cerebrovascular disease are relatively rare. This study was aimed to explore the impact of GAS5 on hypoxia response in nervous cells. PC-12 cells were incubated under anoxic condition to induce hypoxia injury. Regulatory effects of GAS5 on miR-124 and miR-124 on ICAM-1 expression were assessed by qRT-PCR and/or Western blot. Targeting effect of miR-124 on ICAM-1 3'-untranslated regions (UTR) was evaluated through dual luciferase activity assay. The potential regulatory mechanism on hypoxia injury in PC-12 cells was assessed by detecting key elements of NF-κB and Notch signaling pathways using Western blot. GAS5 ectopic expression accentuated hypoxia injury in PC-12 cells. miR-124 expression was negatively regulated by GAS5 expression. Cells with overexpressions of GAS5 and miR-124 alleviated hypoxia injury as in compassion with cells only with GAS5 overexpression. ICAM-1 expression was negatively regulated by miR-124 expression. ICAM-1 was a functional target of miR-124. ICAM-1 overexpression aggravated hypoxia injury, but inversely, ICAM-1 silence diminished hypoxia damage. Besides, ICAM-1 expression was negatively related with activation of NF-κB and Notch pathways. GAS5-miR-124-ICAM-1 axis could regulate hypoxia injury in PC-12 cells. GAS5 might aggravate hypoxia injury via down-regulating miR-124, then up-regulating ICAM-1, and further enhancing activations of NF-κB and Notch pathways. © 2018 Wiley Periodicals, Inc.

Delayed post-ischaemic administration of xenon reduces brain damage in a rat model of global ischaemia.

PubMed

Metaxa, V; Lagoudaki, R; Meditskou, S; Thomareis, O; Oikonomou, L; Sakadamis, A

2014-01-01

Xenon and nitrous oxide have been shown to be neuroprotective in vivo and in vitro, but mainly in models of focal cerebral ischaemia. This study aimed to investigate whether the two gases are able to attenuate cerebral injury after global cerebral ischaemia. Adult male Wistar rats underwent bilateral common carotid artery occlusion and were ventilated for 1 hour with 21% O₂/78% N₂. They were then randomized to three groups which continued to receive atmospheric air, 50% N2O/50% O₂ and 50% Xe/50% O₂ for an additional period of 45 minutes. The number of ischaemic neurons, the cortical volume loss and the immunochemical and molecular expression of c-fos and MMP-9 were evaluated. Xenon reduced the number of ischaemic neurons in the cortex and CA1 hippocampal region (p < 0.001) and decreased the cortical volume loss (p < 0.01). Immunochemical induction of c-fos in the cortex was significantly suppressed (p < 0.01) after administration of xenon. The molecular analysis revealed significant effects of N2O and xenon administration on c-fos and MMP-9 expression. The data indicate that N2O and xenon administration is neuroprotective 1 hour after bilateral common carotid artery occlusion. These findings provide valuable evidence on the beneficial role of N2O and xenon in global cerebral injury.

Xenon Treatment Protects Against Cold Ischemia Associated Delayed Graft Function and Prolongs Graft Survival in Rats

PubMed Central

Zhao, H; Watts, H R; Chong, M; Huang, H; Tralau-Stewart, C; Maxwell, P H; Maze, M; George, A J T; Ma, D

2013-01-01

Prolonged hypothermic storage causes ischemia-reperfusion injury (IRI) in the renal graft, which is considered to contribute to the occurrence of the delayed graft function (DGF) and chronic graft failure. Strategies are required to protect the graft and to prolong renal graft survival. We demonstrated that xenon exposure to human proximal tubular cells (HK-2) led to activation of range of protective proteins. Xenon treatment prior to or after hypothermia–hypoxia challenge stabilized the HK-2 cellular structure, diminished cytoplasmic translocation of high-mobility group box (HMGB) 1 and suppressed NF-κB activation. In the syngeneic Lewis-to-Lewis rat model of kidney transplantation, xenon exposure to donors before graft retrieval or to recipients after engraftment decreased caspase-3 expression, localized HMGB-1 within nuclei and prevented TLR-4/NF-κB activation in tubular cells; serum pro-inflammatory cytokines IL-1β, IL-6 and TNF-α were reduced and renal function was preserved. Xenon treatment of graft donors or of recipients prolonged renal graft survival following IRI in both Lewis-to-Lewis isografts and Fischer-to-Lewis allografts. Xenon induced cell survival or graft functional recovery was abolished by HIF-1α siRNA. Our data suggest that xenon treatment attenuates DGF and enhances graft survival. This approach could be translated into clinical practice leading to a considerable improvement in long-term graft survival. PMID:23710625

7 CFR 4280.124 - Interest rates.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 7 Agriculture 15 2010-01-01 2010-01-01 false Interest rates. 4280.124 Section 4280.124 Agriculture... Improvements Program Section B. Guaranteed Loans § 4280.124 Interest rates. (a) The interest rate for the... in similar circumstances in the ordinary course of business. The interest rate charged is subject to...

34 CFR 303.124 - Data collection.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 34 Education 2 2012-07-01 2012-07-01 false Data collection. 303.124 Section 303.124 Education... Statewide System § 303.124 Data collection. (a) Each statewide system must include a system for compiling and reporting timely and accurate data that meets the requirements in paragraph (b) of this section...

34 CFR 303.124 - Data collection.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 34 Education 2 2013-07-01 2013-07-01 false Data collection. 303.124 Section 303.124 Education... Statewide System § 303.124 Data collection. (a) Each statewide system must include a system for compiling and reporting timely and accurate data that meets the requirements in paragraph (b) of this section...

34 CFR 303.124 - Data collection.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 34 Education 2 2014-07-01 2013-07-01 true Data collection. 303.124 Section 303.124 Education... Statewide System § 303.124 Data collection. (a) Each statewide system must include a system for compiling and reporting timely and accurate data that meets the requirements in paragraph (b) of this section...

Activation of the NF-κB pathway by the STAT3 inhibitor JSI-124 in human glioblastoma cells

PubMed Central

McFarland, Braden C.; Gray, G. Kenneth; Nozell, Susan E.; Hong, Suk W.; Benveniste, Etty N.

2013-01-01

Glioblastoma tumors are characterized by their invasiveness and resistance to therapies. The transcription factor STAT3 was recently identified as a master transcriptional regulator in the mesenchymal subtype of GBM, which has generated an increased interest in targeting STAT3. We have evaluated more closely the mechanism of action of one particular STAT3 inhibitor, JSI-124 (cucurbitacin I). In this study, we confirmed that JSI-124 inhibits both constitutive and stimulus-induced JAK2 and STAT3 phosphorylation, and decreases cell proliferation while inducing apoptosis in cultured GBM cells. However, we discovered that prior to the inhibition of STAT3, JSI-124 activates the NF-κB pathway, via NF-κB p65 phosphorylation and nuclear translocation. In addition, JSI-124 treatment induces the expression of IL-6, IL-8 and SOCS3 mRNA, which leads to a corresponding increase in IL-6, IL-8 and SOCS3 protein expression. Moreover, the NF-κB driven SOCS3 expression acts as a negative regulator of STAT3, abrogating any subsequent STAT3 activation and provides a mechanism of STAT3 inhibition following JSI-124 treatment. Chromatin immunoprecipitation analysis confirms that NF-κB p65 in addition to other activating co-factors are found at the promoters of IL-6, IL-8 and SOCS3, following JSI-124 treatment. Using pharmacological inhibition of NF-κB and inducible knockdown of NF-κB p65, we found that JSI-124-induced expression of IL-6, IL-8 and SOCS3 was significantly inhibited, demonstrating an NF-κB dependent mechanism. Our data indicate that although JSI-124 may demonstrate potential anti-tumor effects through inhibition of STAT3, other off-target pro-inflammatory pathways are activated, emphasizing that more careful and thorough pre-clinical investigations must be implemented to prevent potential harmful effects. PMID:23386688

ARGON, XENON, HYDROGEN, AND THE OXYGEN CONSUMPTION AND GLYCOLYSIS OF MOUSE TISSUE SLICES

PubMed Central

South, Frank E.; Cook, Sherburne F.

1954-01-01

The effects of xenon, argon, and hydrogen on the aerobic and anaerobic metabolism of mouse liver, brain, and sarcoma slices have been investigated. Xenon was found to alter the rates of metabolism of these tissues in a manner almost identical with helium. The gas increased the rate of oxygen consumption in all three tissues and significantly depressed that of anaerobic glycolysis in brain and liver. The depression of glycolysis in sarcoma was less pronounced and not highly significant. Although both the magnitude and statistical significance of the effects observed with argon were much smaller, there was a seeming adherence to the general pattern established by xenon and helium. Hydrogen while remaining essentially ineffective insofar as oxygen uptake was concerned, depressed glycolysis in both liver and brain slices but did not significantly affect sarcoma slices. The following points are stressed in the Discussion: (1) the magnitude and direction of effects exerted by helium, argon, xenon, hydrogen, and nitrogen do not conform with the relative values of molecular weight, density, and solubility of these gases; (2) the effect of these gases on tissue metabolism does not necessarily parallel that exerted upon the whole organism. PMID:13118104

Gpr124 is essential for blood-brain barrier integrity in central nervous system disease.

PubMed

Chang, Junlei; Mancuso, Michael R; Maier, Carolina; Liang, Xibin; Yuki, Kanako; Yang, Lu; Kwong, Jeffrey W; Wang, Jing; Rao, Varsha; Vallon, Mario; Kosinski, Cynthia; Zhang, J J Haijing; Mah, Amanda T; Xu, Lijun; Li, Le; Gholamin, Sharareh; Reyes, Teresa F; Li, Rui; Kuhnert, Frank; Han, Xiaoyuan; Yuan, Jenny; Chiou, Shin-Heng; Brettman, Ari D; Daly, Lauren; Corney, David C; Cheshier, Samuel H; Shortliffe, Linda D; Wu, Xiwei; Snyder, Michael; Chan, Pak; Giffard, Rona G; Chang, Howard Y; Andreasson, Katrin; Kuo, Calvin J

2017-04-01

Although blood-brain barrier (BBB) compromise is central to the etiology of diverse central nervous system (CNS) disorders, endothelial receptor proteins that control BBB function are poorly defined. The endothelial G-protein-coupled receptor (GPCR) Gpr124 has been reported to be required for normal forebrain angiogenesis and BBB function in mouse embryos, but the role of this receptor in adult animals is unknown. Here Gpr124 conditional knockout (CKO) in the endothelia of adult mice did not affect homeostatic BBB integrity, but resulted in BBB disruption and microvascular hemorrhage in mouse models of both ischemic stroke and glioblastoma, accompanied by reduced cerebrovascular canonical Wnt-β-catenin signaling. Constitutive activation of Wnt-β-catenin signaling fully corrected the BBB disruption and hemorrhage defects of Gpr124-CKO mice, with rescue of the endothelial gene tight junction, pericyte coverage and extracellular-matrix deficits. We thus identify Gpr124 as an endothelial GPCR specifically required for endothelial Wnt signaling and BBB integrity under pathological conditions in adult mice. This finding implicates Gpr124 as a potential therapeutic target for human CNS disorders characterized by BBB disruption.

Ethane and Xenon mixing: density functional theory (DFT) simulations and experiments on Sandia's Z machine

NASA Astrophysics Data System (ADS)

Magyar, Rudolph; Root, Seth; Mattsson, Thomas; Cochrane, Kyle

2012-02-01

The combination of ethane and xenon is one of the simplest binary mixtures in which bond breaking is expected to play a role under shock conditions. At cryogenic conditions, xenon is often understood to mix with alkanes such as Ethane as if it were also an alkane, but this model is expected to break down at higher temperatures and pressures. To investigate the breakdown, we have performed density functional theory (DFT) calculations on several xenon/ethane mixtures. Additionally, we have performed shock compression experiments on Xenon-Ethane using the Sandia Z - accelerator. The DFT and experimental results are compared to hydrodynamic simulations using different mixing models in the equation of state. Sandia National Laboratories is a multi-program laboratory operated by Sandia Corporation, a wholly owned subsidiary of the Lockheed Martin company, for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000.

10 CFR 600.124 - Program income.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 10 Energy 4 2010-01-01 2010-01-01 false Program income. 600.124 Section 600.124 Energy DEPARTMENT... Nonprofit Organizations Post-Award Requirements § 600.124 Program income. (a) The standards set forth in this section shall be used to account for program income related to projects financed in whole or in...

14 CFR 1260.124 - Program income.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 5 2010-01-01 2010-01-01 false Program income. 1260.124 Section 1260.124..., Hospitals, and Other Non-Profit Organizations Post-Award Requirements § 1260.124 Program income. (a) The standards set forth in this section shall be used to account for program income related to projects financed...

42 CFR 436.124 - Newborn children.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 42 Public Health 4 2010-10-01 2010-10-01 false Newborn children. 436.124 Section 436.124 Public... the Categorically Needy § 436.124 Newborn children. (a) The agency must provide Medicaid eligibility to a child born to a woman who has applied for, has been determined eligible and is receiving...

42 CFR 436.124 - Newborn children.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 42 Public Health 4 2013-10-01 2013-10-01 false Newborn children. 436.124 Section 436.124 Public... the Categorically Needy § 436.124 Newborn children. (a) The agency must provide Medicaid eligibility to a child born to a woman who has applied for, has been determined eligible and is receiving...

42 CFR 436.124 - Newborn children.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 42 Public Health 4 2011-10-01 2011-10-01 false Newborn children. 436.124 Section 436.124 Public... the Categorically Needy § 436.124 Newborn children. (a) The agency must provide Medicaid eligibility to a child born to a woman who has applied for, has been determined eligible and is receiving...

42 CFR 436.124 - Newborn children.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 42 Public Health 4 2012-10-01 2012-10-01 false Newborn children. 436.124 Section 436.124 Public... the Categorically Needy § 436.124 Newborn children. (a) The agency must provide Medicaid eligibility to a child born to a woman who has applied for, has been determined eligible and is receiving...

42 CFR 436.124 - Newborn children.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 42 Public Health 4 2014-10-01 2014-10-01 false Newborn children. 436.124 Section 436.124 Public... the Categorically Needy § 436.124 Newborn children. (a) The agency must provide Medicaid eligibility to a child born to a woman who has applied for, has been determined eligible and is receiving...

Predictors for postoperative nausea and vomiting after xenon-based anaesthesia.

PubMed

Schaefer, M S; Apfel, C C; Sachs, H-J; Stuttmann, R; Bein, B; Tonner, P H; Hein, M; Neukirchen, M; Reyle-Hahn, M; Kienbaum, P

2015-07-01

In contrast to volatile anaesthetics, xenon acts by antagonism at N-methyl-d-aspartate receptors and antagonizes 5-hydroxytryptamine type 3 receptors that mediate nausea and vomiting. Therefore, it is unknown whether the same risk factors for postoperative nausea and vomiting (PONV) after volatile anaesthetics apply to xenon-based anaesthesia. With ethics committee approval and written informed consent, 502 consecutive patients undergoing xenon-based anaesthesia were included in a multicentre prospective observational study. Antiemetic prophylaxis was administered at the discretion of the attending anaesthetists. Postoperative nausea and vomiting and need for antiemetic rescue medication were assessed for 24 h after anaesthesia. Multivariate logistic regression analysis was performed to quantify risk factors for PONV and need for rescue medication. Four hundred and eighty-eight subjects were available for the final analysis. The incidence of PONV in subjects without prophylaxis was lower than expected according to the Apfel Score (28% observed; 42% expected, P<0.001). Independent predictors for PONV were (adjusted odds ratio; 95% confidence interval) female sex (1.76; 1.08-2.89), younger patient age (0.82 per 10 yr; 0.69-0.97), and longer duration of anaesthesia (1.36 per hour; 1.17-1.59). The incidence of PONV was significantly lower than predicted by the Apfel Score. Female sex, younger age, and longer duration of anaesthesia are risk factors for PONV after xenon-based anaesthesia. German Federal Institute for Drugs and Medical Devices number AL-PMS-01/07GER. © The Author 2015. Published by Oxford University Press on behalf of the British Journal of Anaesthesia. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

13 CFR 124.402 - How does a Participant develop a business plan?

Code of Federal Regulations, 2010 CFR

2010-01-01

... Participant must develop a comprehensive business plan setting forth its business targets, objectives, and... future plans to enter into one or more new markets; (2) The applicant's designation of its primary industry classification, as defined in § 124.3; (3) An analysis of market potential, competitive...

Xenon Protects against Blast-Induced Traumatic Brain Injury in an In Vitro Model.

PubMed

Campos-Pires, Rita; Koziakova, Mariia; Yonis, Amina; Pau, Ashni; Macdonald, Warren; Harris, Katie; Edge, Christopher J; Franks, Nicholas P; Mahoney, Peter F; Dickinson, Robert

2018-04-15

The aim of this study was to evaluate the neuroprotective efficacy of the inert gas xenon as a treatment for patients with blast-induced traumatic brain injury in an in vitro laboratory model. We developed a novel blast traumatic brain injury model using C57BL/6N mouse organotypic hippocampal brain-slice cultures exposed to a single shockwave, with the resulting injury quantified using propidium iodide fluorescence. A shock tube blast generator was used to simulate open field explosive blast shockwaves, modeled by the Friedlander waveform. Exposure to blast shockwave resulted in significant (p < 0.01) injury that increased with peak-overpressure and impulse of the shockwave, and which exhibited a secondary injury development up to 72 h after trauma. Blast-induced propidium iodide fluorescence overlapped with cleaved caspase-3 immunofluorescence, indicating that shock-wave-induced cell death involves apoptosis. Xenon (50% atm) applied 1 h after blast exposure reduced injury 24 h (p < 0.01), 48 h (p < 0.05), and 72 h (p < 0.001) later, compared with untreated control injury. Xenon-treated injured slices were not significantly different from uninjured sham slices at 24 h and 72 h. We demonstrate for the first time that xenon treatment after blast traumatic brain injury reduces initial injury and prevents subsequent injury development in vitro. Our findings support the idea that xenon may be a potential first-line treatment for those with blast-induced traumatic brain injury.

Xenon Protects against Blast-Induced Traumatic Brain Injury in an In Vitro Model

PubMed Central

Campos-Pires, Rita; Koziakova, Mariia; Yonis, Amina; Pau, Ashni; Macdonald, Warren; Harris, Katie; Edge, Christopher J.; Franks, Nicholas P.; Mahoney, Peter F.

2018-01-01

Abstract The aim of this study was to evaluate the neuroprotective efficacy of the inert gas xenon as a treatment for patients with blast-induced traumatic brain injury in an in vitro laboratory model. We developed a novel blast traumatic brain injury model using C57BL/6N mouse organotypic hippocampal brain-slice cultures exposed to a single shockwave, with the resulting injury quantified using propidium iodide fluorescence. A shock tube blast generator was used to simulate open field explosive blast shockwaves, modeled by the Friedlander waveform. Exposure to blast shockwave resulted in significant (p < 0.01) injury that increased with peak-overpressure and impulse of the shockwave, and which exhibited a secondary injury development up to 72 h after trauma. Blast-induced propidium iodide fluorescence overlapped with cleaved caspase-3 immunofluorescence, indicating that shock-wave–induced cell death involves apoptosis. Xenon (50% atm) applied 1 h after blast exposure reduced injury 24 h (p < 0.01), 48 h (p < 0.05), and 72 h (p < 0.001) later, compared with untreated control injury. Xenon-treated injured slices were not significantly different from uninjured sham slices at 24 h and 72 h. We demonstrate for the first time that xenon treatment after blast traumatic brain injury reduces initial injury and prevents subsequent injury development in vitro. Our findings support the idea that xenon may be a potential first-line treatment for those with blast-induced traumatic brain injury. PMID:29285980

Identification of MicroRNA-124-3p as a Putative Epigenetic Signature of Major Depressive Disorder

PubMed Central

Roy, Bhaskar; Dunbar, Michael; Shelton, Richard C; Dwivedi, Yogesh

2017-01-01

Major depressive disorder (MDD) is predicted to be the second leading cause of global disease burden by 2030. A large number of MDD patients do not respond to the currently available medication because of its poorly understood etiology. Recently, studies of microRNAs (miRNAs), which act as a molecular switch of gene expression, have shown promise in identifying a molecular network that could provide significant clues to various psychiatric illnesses. Using an in vitro system, a rodent depression model, and a human postmortem brain, we investigated the role of a brain-enriched, neuron-specific miRNA, miR-124-3p, whose expression is highly dysregulated in stressed rodents, and identified a set of target genes involved in stress response and neural plasticity. We also found that miR-124-3p is epigenetically regulated and its interaction with the RNA-induced silencing complex (RISC) is compromised in MDD. Using blood serum, we found similar dysregulation of miR-124-3p in antidepressant-free MDD subjects. Altogether, our study demonstrates potential contribution of miR-124-3p in the pathophysiology of MDD and suggests that this miRNA may serve as a novel target for drug development and a biomarker for MDD pathogenesis. PMID:27577603

7 CFR 4280.124 - Interest rates.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 7 Agriculture 15 2011-01-01 2011-01-01 false Interest rates. 4280.124 Section 4280.124 Agriculture... Improvements Program Section B. Guaranteed Loans § 4280.124 Interest rates. (a) The interest rate for the... as long as it is a legal rate. The variable rate must be based on published indices, such as money...

42 CFR 124.503 - Compliance level.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 42 Public Health 1 2011-10-01 2011-10-01 false Compliance level. 124.503 Section 124.503 Public... Unable To Pay § 124.503 Compliance level. (a) Annual compliance level. Subject to the provisions of this subpart, a facility is in compliance with its assurance to provide a reasonable volume of services to...

Pairwise additivity in the nuclear magnetic resonance interactions of atomic xenon.

PubMed

Hanni, Matti; Lantto, Perttu; Vaara, Juha

2009-04-14

Nuclear magnetic resonance (NMR) of atomic (129/131)Xe is used as a versatile probe of the structure and dynamics of various host materials, due to the sensitivity of the Xe NMR parameters to intermolecular interactions. The principles governing this sensitivity can be investigated using the prototypic system of interacting Xe atoms. In the pairwise additive approximation (PAA), the binary NMR chemical shift, nuclear quadrupole coupling (NQC), and spin-rotation (SR) curves for the xenon dimer are utilized for fast and efficient evaluation of the corresponding NMR tensors in small xenon clusters Xe(n) (n = 2-12). If accurate, the preparametrized PAA enables the analysis of the NMR properties of xenon clusters, condensed xenon phases, and xenon gas without having to resort to electronic structure calculations of instantaneous configurations for n > 2. The binary parameters for Xe(2) at different internuclear distances were obtained at the nonrelativistic Hartree-Fock level of theory. Quantum-chemical (QC) calculations at the corresponding level were used to obtain the NMR parameters of the Xe(n) (n = 2-12) clusters at the equilibrium geometries. Comparison of PAA and QC data indicates that the direct use of the binary property curves of Xe(2) can be expected to be well-suited for the analysis of Xe NMR in the gaseous phase dominated by binary collisions. For use in condensed phases where many-body effects should be considered, effective binary property functions were fitted using the principal components of QC tensors from Xe(n) clusters. Particularly, the chemical shift in Xe(n) is strikingly well-described by the effective PAA. The coordination number Z of the Xe site is found to be the most important factor determining the chemical shift, with the largest shifts being found for high-symmetry sites with the largest Z. This is rationalized in terms of the density of virtual electronic states available for response to magnetic perturbations.

Clinical efficacy of xenon versus propofol: A systematic review and meta-analysis.

PubMed

Xia, Yimeng; Fang, Hongwei; Xu, Jindong; Jia, Chenfei; Tao, Guorong; Yu, Buwei

2018-05-01

Interest in the anesthetic use of xenon, a noble gas, has waxed and waned for decades, and the clinical effects of xenon are still debated. We performed a meta-analysis to compare the clinical efficacy of xenon with that of propofol. Electronic searches were performed through December 2017 using various databases, including PubMed, Embase, and the Cochrane Library. We identified thirteen trials that included a total of 817 patients. Patients treated with xenon had a lower bispectral index (BIS) (weighted mean difference (WMD): -6.26, 95% confidence interval (CI): -11.33 to -1.18, P = .02), a higher mean arterial blood pressure (MAP) (WMD: 7.00, 95% CI: 2.32-11.68, P = .003) and a lower heart rate (HR) (WMD: -9.45, 95% CI: -12.28 to -6.63, P < 0.00001) than propofol-treated patients. However, there were no significant differences between the 2 treatment groups in the effects of nondepolarizing muscular relaxants, the duration spent in the postanesthesia care unit (PACU) (WMD: -0.94, 95% CI: -8.79-6.91, P = .81), or the incidence of perioperative complications [assessed using the outcomes of postoperative nausea and vomiting (PONV) (relative risk (RR): 2.01, 95% CI: 0.79-5.11, P = .14), hypotension (RR: 0.62, 95% CI: 0.27 to 1.40, P = .25), hypertension (RR: 1.27, 95% CI: 0.73-2.21, P = .39) and bradycardia (RR: 1.00, 95% CI: 0.36-2.74, P = 1.00)]. In this meta-analysis of randomized controlled trials, we found that xenon treatment resulted in a higher MAP, a lower HR, and a smaller BIS index than treatment with propofol.

Upregulation of miR-124 by physcion 8-O-β-glucopyranoside inhibits proliferation and invasion of malignant melanoma cells via repressing RLIP76.

PubMed

Zhang, Di; Han, Yantao; Xu, Luo

2016-12-01

Melanoma is the most malignant type of skin cancer. In recent years, mounting studies have evidenced the involvement of miRNAs in melanoma. One of these miRNAs, miR-124 has been found aberrantly downregulated in a variety of human malignancies. In this study, our results showed that the expression of miR-124 was significantly lower in malignant melanoma tissues and cell lines and miR-124 functioned as a tumor suppressor in melanoma. Moreover, our findings showed that miR-124 exerted anti-tumor effect by directly targeting RLIP76, a stress-inducible non-ABC transporter that plays a crucial role in the development of melanoma. Furthermore, our study also showed that physcion 8-O-β-glucopyranoside, a natural compound from medicinal plant, could inhibit the proliferation and invasion of melanoma cells by targeting miR-124/RLIP76 signaling. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

Inner-Shell Electron Recoil Discrimination in Xenon

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

Trask, Makayla; Lippincott, Hugh; Baxter, Dan

2017-01-01

\\bulletmore » $$$$ Dark matter searches using time projection chambers (TPCs) rely on the ability to distinguish between nuclear and electron interactions $$$$ Xenon TPCs are specifically searching for a low energy nuclear recoil ( < 30 keV ) signal $$$$ To do this, these interactions must be discernable from the electron recoil background« less

Sputtering of cobalt and chromium by argon and xenon ions near the threshold energy region

NASA Technical Reports Server (NTRS)

Handoo, A. K.; Ray, P. K.

1993-01-01

Sputtering yields of cobalt and chromium by argon and xenon ions with energies below 50 eV are reported. The targets were electroplated on copper substrates. Measurable sputtering yields were obtained from cobalt with ion energies as low as 10 eV. The ion beams were produced by an ion gun. A radioactive tracer technique was used for the quantitative measurement of the sputtering yield. Co-57 and Cr-51 were used as tracers. The yield-energy curves are observed to be concave, which brings into question the practice of finding threshold energies by linear extrapolation.

The search for majoron emission in xenon-136 and two-neutrino double-beta decay of xenon-134 with the enriched xenon observatory

NASA Astrophysics Data System (ADS)

Walton, Josiah

Despite neutrino oscillation experiments firmly establishing neutrinos have non-zero mass, the absolute mass scale is unknown. Moreover, it's unknown whether the neutrino is distinguishable from its antiparticle. The most promising approach for measuring the neutrino mass scale and answering the issue of neutrino-antineutrino distinguishability is by searching for neutrinoless double-beta decay, a very rare theorized process not allowed under the current theoretical framework of particle physics. Positive observation of neutrinoless double-beta decay would usher in a revolution in particle physics, since it would determine the neutrino mass scale, establish that neutrinos and antineutrinos are indistinguishable, and that the particle physics conservation law of total lepton number is violated in nature. The latter two consequences are particularly salient, as they lead to potential explanations of neutrino mass generation and the observed large asymmetry of matter over antimatter in the universe. The Enriched Xenon Observatory (EXO-200) is an international collaboration searching for the neutrinoless double-beta decay of the isotope 136 Xe. EXO-200 operates a unique world-class low-radioactivity detector containing 110 kg of liquified xenon isotopically enriched to 80.6% in 136Xe. Recently, EXO-200 published the most precise two-neutrino double-beta decay half-life ever measured and one of the strongest limits on the half-life of the neutrinoless double-beta decay mode of 136Xe. This work presents an improved experimental search for the majoron-mediated neutrinoless double-beta decay modes of 136Xe and a novel search for the yet unobserved two neutrino double-beta decay of 134Xe.

Shear Thinning Near the Critical Point of Xenon

NASA Technical Reports Server (NTRS)

Zimmerli, Gregory A.; Berg, Robert F.; Moldover, Michael R.; Yao, Minwu

2008-01-01

We measured shear thinning, a viscosity decrease ordinarily associated with complex liquids, near the critical point of xenon. The data span a wide range of reduced shear rate: 10(exp -3) < gamma-dot tau < 700, where gamma-dot tau is the shear rate scaled by the relaxation time tau of critical fluctuations. The measurements had a temperature resolution of 0.01 mK and were conducted in microgravity aboard the Space Shuttle Columbia to avoid the density stratification caused by Earth's gravity. The viscometer measured the drag on a delicate nickel screen as it oscillated in the xenon at amplitudes 3 mu,m < chi (sub 0) >430 mu, and frequencies 1 Hz < omega/2 pi < 5 Hz. To separate shear thinning from other nonlinearities, we computed the ratio of the viscous force on the screen at gamma-dot tau to the force at gamma-dot tau approximates 0: C(sub gamma) is identical with F(chi(sub 0), omega tau, gamma-dot tau )/F)(chi(sub 0, omega tau, 0). At low frequencies, (omega tau)(exp 2) < gamma-dot tau, C(sub gamma) depends only on gamma-dot tau, as predicted by dynamic critical scaling. At high frequencies, (omega tau)(exp 2) > gamma-dot tau, C(sub gamma) depends also on both x(sub 0) and omega. The data were compared with numerical calculations based on the Carreau-Yasuda relation for complex fluids: eta(gamma-dot)/eta(0)=[1+A(sub gamma)|gamma-dot tau|](exp - chi(sub eta)/3+chi(sub eta)), where chi(sub eta) =0.069 is the critical exponent for viscosity and mode-coupling theory predicts A(sub gamma) =0.121. For xenon we find A(sub gamma) =0.137 +/- 0.029, in agreement with the mode coupling value. Remarkably, the xenon data close to the critical temperature T(sub c) were independent of the cooling rate (both above and below T(sub c) and these data were symmetric about T(sub c) to within a temperature scale factor. The scale factors for the magnitude of the oscillator s response differed from those for the oscillator's phase; this suggests that the surface tension of the two

Nausea and Vomiting following Balanced Xenon Anesthesia Compared to Sevoflurane: A Post-Hoc Explorative Analysis of a Randomized Controlled Trial.

PubMed

Fahlenkamp, Astrid V; Stoppe, Christian; Cremer, Jan; Biener, Ingeborg A; Peters, Dirk; Leuchter, Ricarda; Eisert, Albrecht; Apfel, Christian C; Rossaint, Rolf; Coburn, Mark

2016-01-01

Like other inhalational anesthetics xenon seems to be associated with post-operative nausea and vomiting (PONV). We assessed nausea incidence following balanced xenon anesthesia compared to sevoflurane, and dexamethasone for its prophylaxis in a randomized controlled trial with post-hoc explorative analysis. 220 subjects with elevated PONV risk (Apfel score ≥2) undergoing elective abdominal surgery were randomized to receive xenon or sevoflurane anesthesia and dexamethasone or placebo after written informed consent. 93 subjects in the xenon group and 94 subjects in the sevoflurane group completed the trial. General anesthesia was maintained with 60% xenon or 2.0% sevoflurane. Dexamethasone 4mg or placebo was administered in the first hour. Subjects were analyzed for nausea and vomiting in predefined intervals during a 24h post-anesthesia follow-up. Logistic regression, controlled for dexamethasone and anesthesia/dexamethasone interaction, showed a significant risk to develop nausea following xenon anesthesia (OR 2.30, 95% CI 1.02-5.19, p = 0.044). Early-onset nausea incidence was 46% after xenon and 35% after sevoflurane anesthesia (p = 0.138). After xenon, nausea occurred significantly earlier (p = 0.014), was more frequent and rated worse in the beginning. Dexamethasone did not markedly reduce nausea occurrence in both groups. Late-onset nausea showed no considerable difference between the groups. In our study setting, xenon anesthesia was associated with an elevated risk to develop nausea in sensitive subjects. Dexamethasone 4mg was not effective preventing nausea in our study. Group size or dosage might have been too small, and change of statistical analysis parameters in the post-hoc evaluation might have further contributed to a limitation of our results. Further trials will be needed to address prophylaxis of xenon-induced nausea. EU Clinical Trials EudraCT-2008-004132-20 ClinicalTrials.gov NCT00793663.

Nausea and Vomiting following Balanced Xenon Anesthesia Compared to Sevoflurane: A Post-Hoc Explorative Analysis of a Randomized Controlled Trial

PubMed Central

Fahlenkamp, Astrid V.; Stoppe, Christian; Cremer, Jan; Biener, Ingeborg A.; Peters, Dirk; Leuchter, Ricarda; Eisert, Albrecht; Apfel, Christian C.; Rossaint, Rolf; Coburn, Mark

2016-01-01

Objective Like other inhalational anesthetics xenon seems to be associated with post-operative nausea and vomiting (PONV). We assessed nausea incidence following balanced xenon anesthesia compared to sevoflurane, and dexamethasone for its prophylaxis in a randomized controlled trial with post-hoc explorative analysis. Methods 220 subjects with elevated PONV risk (Apfel score ≥2) undergoing elective abdominal surgery were randomized to receive xenon or sevoflurane anesthesia and dexamethasone or placebo after written informed consent. 93 subjects in the xenon group and 94 subjects in the sevoflurane group completed the trial. General anesthesia was maintained with 60% xenon or 2.0% sevoflurane. Dexamethasone 4mg or placebo was administered in the first hour. Subjects were analyzed for nausea and vomiting in predefined intervals during a 24h post-anesthesia follow-up. Results Logistic regression, controlled for dexamethasone and anesthesia/dexamethasone interaction, showed a significant risk to develop nausea following xenon anesthesia (OR 2.30, 95% CI 1.02–5.19, p = 0.044). Early-onset nausea incidence was 46% after xenon and 35% after sevoflurane anesthesia (p = 0.138). After xenon, nausea occurred significantly earlier (p = 0.014), was more frequent and rated worse in the beginning. Dexamethasone did not markedly reduce nausea occurrence in both groups. Late-onset nausea showed no considerable difference between the groups. Conclusion In our study setting, xenon anesthesia was associated with an elevated risk to develop nausea in sensitive subjects. Dexamethasone 4mg was not effective preventing nausea in our study. Group size or dosage might have been too small, and change of statistical analysis parameters in the post-hoc evaluation might have further contributed to a limitation of our results. Further trials will be needed to address prophylaxis of xenon-induced nausea. Trial Registration EU Clinical Trials EudraCT-2008-004132-20 ClinicalTrials.gov NCT

Xenon treatment protects against cold ischemia associated delayed graft function and prolongs graft survival in rats.

PubMed

Zhao, H; Watts, H R; Chong, M; Huang, H; Tralau-Stewart, C; Maxwell, P H; Maze, M; George, A J T; Ma, D

2013-08-01

Prolonged hypothermic storage causes ischemia-reperfusion injury (IRI) in the renal graft, which is considered to contribute to the occurrence of the delayed graft function (DGF) and chronic graft failure. Strategies are required to protect the graft and to prolong renal graft survival. We demonstrated that xenon exposure to human proximal tubular cells (HK-2) led to activation of range of protective proteins. Xenon treatment prior to or after hypothermia-hypoxia challenge stabilized the HK-2 cellular structure, diminished cytoplasmic translocation of high-mobility group box (HMGB) 1 and suppressed NF-κB activation. In the syngeneic Lewis-to-Lewis rat model of kidney transplantation, xenon exposure to donors before graft retrieval or to recipients after engraftment decreased caspase-3 expression, localized HMGB-1 within nuclei and prevented TLR-4/NF-κB activation in tubular cells; serum pro-inflammatory cytokines IL-1β, IL-6 and TNF-α were reduced and renal function was preserved. Xenon treatment of graft donors or of recipients prolonged renal graft survival following IRI in both Lewis-to-Lewis isografts and Fischer-to-Lewis allografts. Xenon induced cell survival or graft functional recovery was abolished by HIF-1α siRNA. Our data suggest that xenon treatment attenuates DGF and enhances graft survival. This approach could be translated into clinical practice leading to a considerable improvement in long-term graft survival. © Copyright 2013 The American Society of Transplantation and the American Society of Transplant Surgeons.

40 CFR 426.124 - [Reserved

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 31 2012-07-01 2012-07-01 false [Reserved] 426.124 Section 426.124 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS (CONTINUED) GLASS MANUFACTURING POINT SOURCE CATEGORY Incandescent Lamp Envelope Manufacturing Subcategory...

40 CFR 426.124 - [Reserved

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 30 2014-07-01 2014-07-01 false [Reserved] 426.124 Section 426.124 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS (CONTINUED) GLASS MANUFACTURING POINT SOURCE CATEGORY Incandescent Lamp Envelope Manufacturing Subcategory...

40 CFR 426.124 - [Reserved

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 31 2013-07-01 2013-07-01 false [Reserved] 426.124 Section 426.124 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS (CONTINUED) GLASS MANUFACTURING POINT SOURCE CATEGORY Incandescent Lamp Envelope Manufacturing Subcategory...

Formation of medical radioisotopes 111In, 117 m Sn, 124Sb, and 177Lu in photonuclear reactions

NASA Astrophysics Data System (ADS)

Danagulyan, A. S.; Hovhannisyan, G. H.; Bakhshiyan, T. M.; Avagyan, R. H.; Avetisyan, A. E.; Kerobyan, I. A.; Dallakyan, R. K.

2015-06-01

The possibility of the photonuclear production of radioisotopes 111In, 117 m Sn, 124Sb, and 177Lu is discussed. Reaction yields were measured by the gamma-activation method. The enriched tin isotopes 112, 118Sn and Te and HfO2 of natural isotopic composition were used as targets. The targets were irradiated at the linear electron accelerator of Alikhanian National Science Laboratory (Yerevan) at the energy of 40 MeV. The experimental results obtained in this way reveal that the yield and purity of radioisotopes 111In and 117 mSn are acceptable for their production via photonuclear reactions. Reactions proceeding on targets from Te and HfO2 of natural isotopic composition and leading to the formation of 124Sb and 177Lu have small yields and are hardly appropriate for the photoproduction of these radioisotopes even in the case of enriched targets.

Development and evaluation of a silver mordenite composite sorbent for the partitioning of xenon from krypton in gas compositions

DOE PAGES

Garn, Troy G.; Greenhalgh, Mitchell; Law, Jack D.

2015-12-22

A new engineered form composite sorbent for the selective separation of xenon from krypton in simulant composition off-gas streams resulting from the reprocessing of used nuclear fuel has been developed and evaluated. A sodium mordenite powder was incorporated into a macroporous polymer binder, formed into spherical beads and successfully converted to a 9 wt.% silver form composite sorbent. The final engineered form sorbent retained the characteristic surface area indicative of sodium mordenite powder. The sorbent was evaluated for xenon adsorption potential with capacities measured as high as 30 millimoles of xenon per kilogram of sorbent achieved at ambient temperature andmore » 460 millimoles of xenon per kilogram sorbent at 220 K. Xenon/krypton selectivity was calculated to be 22.4 with a 1020 µL/L xenon, 150 µL/L krypton in a balance of air feed gas at 220 K. Furthermore, adsorption/desorption thermal cycling effects were evaluated with results indicating sorbent performance was not significantly impacted while undergoing numerous adsorption/desorption thermal cycles.« less

Evaluation of hemodynamic effects of xenon in dogs undergoing hemorrhagic shock

PubMed Central

Franceschi, Ruben C.; Malbouisson, Luiz; Yoshinaga, Eduardo; Auler, José Otavio Costa; de Figueiredo (in memoriam), Luiz Francisco Poli; Carmona, Maria José C.

2013-01-01

OBJECTIVES: The anesthetic gas xenon is reported to preserve hemodynamic stability during general anesthesia. However, the effects of the gas during shock are unclear. The objective of this study was to evaluate the effect of Xe on hemodynamic stability and tissue perfusion in a canine model of hemorrhagic shock. METHOD: Twenty-six dogs, mechanically ventilated with a fraction of inspired oxygen of 21% and anesthetized with etomidate and vecuronium, were randomized into Xenon (Xe; n = 13) or Control (C; n = 13) groups. Following hemodynamic monitoring, a pressure-driven shock was induced to reach an arterial pressure of 40 mmHg. Hemodynamic data and blood samples were collected prior to bleeding, immediately after bleeding and 5, 20 and 40 minutes following shock. The Xe group was treated with 79% Xe diluted in ambient air, inhaled for 20 minutes after shock. RESULT: The mean bleeding volume was 44 mL.kg−1 in the C group and 40 mL.kg−1 in the Xe group. Hemorrhage promoted a decrease in both the cardiac index (p<0.001) and mean arterial pressure (p<0.001). These changes were associated with an increase in lactate levels and worsening of oxygen transport variables in both groups (p<0.05). Inhalation of xenon did not cause further worsening of hemodynamics or tissue perfusion markers. CONCLUSIONS: Xenon did not alter hemodynamic stability or tissue perfusion in an experimentally controlled hemorrhagic shock model. However, further studies are necessary to validate this drug in other contexts. PMID:23525321

Frequency-Dependent Viscosity of Xenon Near the Critical Point

NASA Technical Reports Server (NTRS)

Berg, Robert F.; Moldover, Michael R.; Zimmerli, Gregory A.

1999-01-01

We used a novel, overdamped oscillator aboard the Space Shuttle to measure the viscosity eta of xenon near its critical density rho(sub c), and temperature T(sub c). In microgravity, useful data were obtained within 0.1 mK of T(sub c), corresponding to a reduced temperature t = (T -T(sub c))/T(sub c) = 3 x 10(exp -7). The data extend two decades closer to T(sub c) than the best ground measurements, and they directly reveal the expected power-law behavior eta proportional to t(sup -(nu)z(sub eta)). Here nu is the correlation length exponent, and our result for the small viscosity exponent is z(sub eta) = 0.0690 +/- 0.0006. (All uncertainties are one standard uncertainty.) Our value for z(sub eta) depends only weakly on the form of the viscosity crossover function, and it agrees with the value 0.067 +/- 0.002 obtained from a recent two-loop perturbation expansion. The measurements spanned the frequency range 2 Hz less than or equal to f less than or equal to 12 Hz and revealed viscoelasticity when t less than or equal to 10(exp -1), further from T(sub c) than predicted. The viscoelasticity scales as Af(tau), where tau is the fluctuation-decay time. The fitted value of the viscoelastic time-scale parameter A is 2.0 +/- 0.3 times the result of a one-loop perturbation calculation. Near T(sub c), the xenon's calculated time constant for thermal diffusion exceeded days. Nevertheless, the viscosity results were independent of the xenon's temperature history, indicating that the density was kept near rho(sub c), by judicious choices of the temperature vs. time program. Deliberately bad choices led to large density inhomogeneities. At t greater than 10(exp -5), the xenon approached equilibrium much faster than expected, suggesting that convection driven by microgravity and by electric fields slowly stirred the sample.

Measurement of the absolute reflectance of polytetrafluoroethylene (PTFE) immersed in liquid xenon

NASA Astrophysics Data System (ADS)

Neves, F.; Lindote, A.; Morozov, A.; Solovov, V.; Silva, C.; Bras, P.; Rodrigues, J. P.; Lopes, M. I.

2017-01-01

The performance of a detector using liquid xenon (LXe) as a scintillator is strongly dependent on the collection efficiency for xenon scintillation light, which in turn is critically dependent on the reflectance of the surfaces that surround the active volume. To improve the light collection in such detectors the active volume is usually surrounded by polytetrafluoroethylene (PTFE) reflector panels, used due to its very high reflectance—even at the short wavelength of scintillation light of LXe (peaked at 178 nm). In this work, which contributed to the overall R&D effort towards the LUX-ZEPLIN (LZ) experiment, we present experimental results for the absolute reflectance measurements of three different PTFE samples (including the material used in the LUX detector) immersed in LXe for its scintillation light. The obtained results show that very high bi-hemispherical reflectance values (>= 97%) can be achieved, enabling very low energy thresholds in liquid xenon scintillator-based detectors.

Convective Heating of the LIFE Engine Target During Injection

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

Holdener, D S; Tillack, M S; Wang, X R

2011-10-24

Target survival in the hostile, high temperature xenon environment of the proposed Laser Inertial Fusion Energy (LIFE) engine is critical. This work focuses on the flow properties and convective heat load imposed upon the surface of the indirect drive target while traveling through the xenon gas. While this rarefied flow is traditionally characterized as being within the continuum regime, it is approaching transition where conventional CFD codes reach their bounds of operation. Thus ANSYS, specifically the Navier-Stokes module CFX, will be used in parallel with direct simulation Monte Carlo code DS2V and analytically and empirically derived expressions for heat transfermore » to the hohlraum for validation. Comparison of the viscous and thermal boundary layers of ANSYS and DS2V were shown to be nearly identical, with the surface heat flux varying less than 8% on average. From the results herein, external baffles have been shown to reduce this heat transfer to the sensitive laser entrance hole (LEH) windows and optimize target survival independent of other reactor parameters.« less

7 CFR 948.124 - Reports.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 7 Agriculture 8 2010-01-01 2010-01-01 false Reports. 948.124 Section 948.124 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements... point; destination; consignee; the inspection certificate number when inspection is required; and any...

7 CFR 959.124 - Reports.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 7 Agriculture 8 2010-01-01 2010-01-01 false Reports. 959.124 Section 959.124 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements...; destination; consignee; the inspection certificate number when inspection is required; and any other...

Research on the measurement of the ultraviolet irradiance in the xenon lamp aging test chamber

NASA Astrophysics Data System (ADS)

Ji, Muyao; Li, Tiecheng; Lin, Fangsheng; Yin, Dejin; Cheng, Weihai; Huang, Biyong; Lai, Lei; Xia, Ming

2018-01-01

This paper briefly introduces the methods of calibrating the irradiance in the Xenon lamp aging test chamber. And the irradiance under ultraviolet region is mainly researched. Three different detectors whose response wave range are respectively UVA (320 400nm), UVB (275 330nm) and UVA+B (280 400nm) are used in the experiment. Through comparing the measuring results with different detectors under the same xenon lamp source, we discuss the difference between UVA, UVB and UVA+B on the basis of the spectrum of the xenon lamp and the response curve of the detectors. We also point out the possible error source, when use these detectors to calibrate the chamber.

Influence of atmospheric transport patterns on xenon detections at the CTBTO radionuclide network

NASA Astrophysics Data System (ADS)

Krysta, Monika; Kusmierczyk-Michulec, Jolanta

2016-04-01

In order to fulfil its task of monitoring for signals emanating from nuclear explosions, Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO) operates global International Monitoring System (IMS) comprising seismic, infrasound, hydroacoustic and radionuclide measurement networks. At present, 24 among 80 radionuclide stations foreseen by the Comprehensive Nuclear-Test-Ban Treaty (CTBT) are equipped with certified noble gas measurement systems. Over a past couple of years these systems collected a rich set of measurements of radioactive isotopes of xenon. Atmospheric transport modelling simulations are crucial to an assessment of the origin of xenon detected at the IMS stations. Numerous studies undertaken in the past enabled linking these detections to non Treaty-relevant activities and identifying main contributors. Presence and quantity of xenon isotopes at the stations is hence a result of an interplay of emission patterns and atmospheric circulation. In this presentation we analyse the presence or absence of radioactive xenon at selected stations from an angle of such an interplay. We attempt to classify the stations according to similarity of detection patterns, examine seasonality in those patterns and link them to large scale or local meteorological phenomena. The studies are undertaken using crude hypotheses on emission patterns from known sources and atmospheric transport modelling simulations prepared with the FLEXPART model.

The MicroRNA miR-124 promotes neuronal differentiation by triggering brain-specific alternative pre-mRNA splicing.

PubMed

Makeyev, Eugene V; Zhang, Jiangwen; Carrasco, Monica A; Maniatis, Tom

2007-08-03

Both microRNAs and alternative pre-mRNA splicing have been implicated in the development of the nervous system (NS), but functional interactions between these two pathways are poorly understood. We demonstrate that the neuron-specific microRNA miR-124 directly targets PTBP1 (PTB/hnRNP I) mRNA, which encodes a global repressor of alternative pre-mRNA splicing in nonneuronal cells. Among the targets of PTBP1 is a critical cassette exon in the pre-mRNA of PTBP2 (nPTB/brPTB/PTBLP), an NS-enriched PTBP1 homolog. When this exon is skipped, PTBP2 mRNA is subject to nonsense-mediated decay (NMD). During neuronal differentiation, miR-124 reduces PTBP1 levels, leading to the accumulation of correctly spliced PTBP2 mRNA and a dramatic increase in PTBP2 protein. These events culminate in the transition from non-NS to NS-specific alternative splicing patterns. We also present evidence that miR-124 plays a key role in the differentiation of progenitor cells to mature neurons. Thus, miR-124 promotes NS development, at least in part by regulating an intricate network of NS-specific alternative splicing.

A relativistic coupled-cluster interaction potential and rovibrational constants for the xenon dimer

NASA Astrophysics Data System (ADS)

Jerabek, Paul; Smits, Odile; Pahl, Elke; Schwerdtfeger, Peter

2018-01-01

An accurate potential energy curve has been derived for the xenon dimer using state-of-the-art relativistic coupled-cluster theory up to quadruple excitations accounting for both basis set superposition and incompleteness errors. The data obtained is fitted to a computationally efficient extended Lennard-Jones potential form and to a modified Tang-Toennies potential function treating the short- and long-range part separately. The vibrational spectrum of Xe2 obtained from a numerical solution of the rovibrational Schrödinger equation and subsequently derived spectroscopic constants are in excellent agreement with experimental values. We further present solid-state calculations for xenon using a static many-body expansion up to fourth-order in the xenon interaction potential including dynamic effects within the Einstein approximation. Again we find very good agreement with the experimental (face-centred cubic) lattice constant and cohesive energy.

Fluorination of amorphous thin-film materials with xenon fluoride

DOEpatents

Weil, R.B.

1987-05-01

A method is disclosed for producing fluorine-containing amorphous semiconductor material, preferably comprising amorphous silicon. The method includes depositing amorphous thin-film material onto a substrate while introducing xenon fluoride during the film deposition process.

Fluorination of amorphous thin-film materials with xenon fluoride

DOEpatents

Weil, Raoul B.

1988-01-01

A method is disclosed for producing fluorine-containing amorphous semiconductor material, preferably comprising amorphous silicon. The method includes depositing amorphous thin-film material onto a substrate while introducing xenon fluoride during the film deposition process.

7 CFR 945.124 - Reports.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 7 Agriculture 8 2010-01-01 2010-01-01 false Reports. 945.124 Section 945.124 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements... address of the shipper; the car or truck identification; the loading point; destination; consignee; the...

19 CFR 12.4 - Exportation.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 19 Customs Duties 1 2011-04-01 2011-04-01 false Exportation. 12.4 Section 12.4 Customs Duties U.S. CUSTOMS AND BORDER PROTECTION, DEPARTMENT OF HOMELAND SECURITY; DEPARTMENT OF THE TREASURY SPECIAL CLASSES OF MERCHANDISE Food, Drugs, and Cosmetics, Economic Poisons, Hazardous Substances, and Dangerous...

19 CFR 12.4 - Exportation.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 19 Customs Duties 1 2010-04-01 2010-04-01 false Exportation. 12.4 Section 12.4 Customs Duties U.S. CUSTOMS AND BORDER PROTECTION, DEPARTMENT OF HOMELAND SECURITY; DEPARTMENT OF THE TREASURY SPECIAL CLASSES OF MERCHANDISE Food, Drugs, and Cosmetics, Economic Poisons, Hazardous Substances, and Dangerous...

19 CFR 12.4 - Exportation.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 19 Customs Duties 1 2014-04-01 2014-04-01 false Exportation. 12.4 Section 12.4 Customs Duties U.S. CUSTOMS AND BORDER PROTECTION, DEPARTMENT OF HOMELAND SECURITY; DEPARTMENT OF THE TREASURY SPECIAL CLASSES OF MERCHANDISE Food, Drugs, and Cosmetics, Economic Poisons, Hazardous Substances, and Dangerous...

19 CFR 12.4 - Exportation.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 19 Customs Duties 1 2012-04-01 2012-04-01 false Exportation. 12.4 Section 12.4 Customs Duties U.S. CUSTOMS AND BORDER PROTECTION, DEPARTMENT OF HOMELAND SECURITY; DEPARTMENT OF THE TREASURY SPECIAL CLASSES OF MERCHANDISE Food, Drugs, and Cosmetics, Economic Poisons, Hazardous Substances, and Dangerous...

19 CFR 12.4 - Exportation.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 19 Customs Duties 1 2013-04-01 2013-04-01 false Exportation. 12.4 Section 12.4 Customs Duties U.S. CUSTOMS AND BORDER PROTECTION, DEPARTMENT OF HOMELAND SECURITY; DEPARTMENT OF THE TREASURY SPECIAL CLASSES OF MERCHANDISE Food, Drugs, and Cosmetics, Economic Poisons, Hazardous Substances, and Dangerous...

Xenon plasma sustained by pulse-periodic laser radiation

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

Rudoy, I. G.; Solovyov, N. G.; Soroka, A. M.

2015-10-15

The possibility of sustaining a quasi-stationary pulse-periodic optical discharge (POD) in xenon at a pressure of p = 10–20 bar in a focused 1.07-μm Yb{sup 3+} laser beam with a pulse repetition rate of f{sub rep} ⩾ 2 kHz, pulse duration of τ ⩾ 200 μs, and power of P = 200–300 W has been demonstrated. In the plasma development phase, the POD pulse brightness is generally several times higher than the stationary brightness of a continuous optical discharge at the same laser power, which indicates a higher plasma temperature in the POD regime. Upon termination of the laser pulse,more » plasma recombines and is then reinitiated in the next pulse. The initial absorption of laser radiation in successive POD pulses is provided by 5p{sup 5}6s excited states of xenon atoms. This kind of discharge can be applied in plasma-based high-brightness broadband light sources.« less

Modeling Xenon Tank Pressurization using One-Dimensional Thermodynamic and Heat Transfer Equations

NASA Technical Reports Server (NTRS)

Gilligan, Ryan P.; Tomsik, Thomas M.

2017-01-01

As a first step in understanding what ground support equipment (GSE) is required to provide external cooling during the loading of 5,000 kg of xenon into 4 aluminum lined composite overwrapped pressure vessels (COPVs), a modeling analysis was performed using Microsoft Excel. The goals of the analysis were to predict xenon temperature and pressure throughout loading at the launch facility, estimate the time required to load one tank, and to get an early estimate of what provisions for cooling xenon might be needed while the tanks are being filled. The model uses the governing thermodynamic and heat transfer equations to achieve these goals. Results indicate that a single tank can be loaded in about 15 hours with reasonable external coolant requirements. The model developed in this study was successfully validated against flight and test data. The first data set is from the Dawn mission which also utilizes solar electric propulsion with xenon propellant, and the second is test data from the rapid loading of a hydrogen cylindrical COPV. The main benefit of this type of model is that the governing physical equations using bulk fluid solid temperatures can provide a quick and accurate estimate of the state of the propellant throughout loading which is much cheaper in terms of computational time and licensing costs than a Computation Fluid Dynamics (CFD) analysis while capturing the majority of the thermodynamics and heat transfer.

7 CFR 987.124 - Nomination and polling.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 7 Agriculture 8 2010-01-01 2010-01-01 false Nomination and polling. 987.124 Section 987.124 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing... IN RIVERSIDE COUNTY, CALIFORNIA Administrative Rules Nominations § 987.124 Nomination and polling. (a...

Adding 5 h delayed xenon to delayed hypothermia treatment improves long-term function in neonatal rats surviving to adulthood.

PubMed

Liu, Xun; Dingley, John; Scull-Brown, Emma; Thoresen, Marianne

2015-06-01

We previously reported that combining immediate hypothermia with immediate or 2 h delayed inhalation of an inert gas, xenon, gave additive neuroprotection in rats after a hypoxic-ischemic insult, compared to hypothermia alone. Defining the therapeutic time window for this new combined intervention is crucial in clinical practice when immediate treatment is not always feasible. The aim of this study is to investigate whether combined hypothermia and xenon still provide neuroprotection in rats after a 5 h delay for both hypothermia and xenon. Seven-day-old Wistar rat pups underwent a unilateral hypoxic-ischemic insult. Pups received 5 h of treatment starting 5 h after the insult randomized between normothermia, hypothermia, or hypothermia with 50% xenon. Surviving pups were tested for fine motor function through weeks 8-10 before being euthanized at week 11. Their hemispheric and hippocampal areas were assessed. Both delayed hypothermia-xenon and hypothermia-only treated groups had significantly less brain tissue loss than those which underwent normothermia. The functional performance after 1 wk and adulthood was significantly better after hypothermia-xenon treatment as compared to the hypothermia-only or normothermia groups. Adding 50% xenon to 5 h delayed hypothermia significantly improved functional outcome as compared to delayed hypothermia alone despite similar reductions in brain area.

32 CFR 219.124 - Conditions.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 32 National Defense 2 2014-07-01 2014-07-01 false Conditions. 219.124 Section 219.124 National Defense Department of Defense (Continued) OFFICE OF THE SECRETARY OF DEFENSE (CONTINUED) MISCELLANEOUS... research projects the department or agency head may impose additional conditions prior to or at the time of...

Reflectance measurements of PTFE, Kapton, and PEEK for xenon scintillation light for the LZ detector.

NASA Astrophysics Data System (ADS)

Arthurs, M.; Batista, E.; Haefner, J.; Lorenzon, W.; Morton, D.; Neff, A.; Okunawo, M.; Pushkin, K.; Sander, A.; Stephenson, S.; Wang, Y.; LZ Collaboration

2017-01-01

LZ (LUX-Zeplin) is an international collaboration that will look for dark matter candidates, WIMPs (Weakly Interacting Massive Particles), through direct detection by dual-phase time projection chamber (TPC) using liquid xenon. The LZ detector will be located nearly a mile underground at SURF, South Dakota, shielded from cosmic background radiation. Seven tons active mass of liquid xenon will be used for detecting the weak interaction of WIMPs with ordinary matter. Over three years of operation it is expected to reach the ultimate sensitivity of 2x10-48 cm2 for a WIMP mass of 50 GeV. As for many other rare event searches, high light collection efficiency is essential for LZ detector. Moreover, in order to achieve greater active volume for detection as well as reduce potential backgrounds, thinner detector walls without significant loss in reflectance are desired. Reflectance measurements of polytetrafluoroethylene (PTFE), Kapton, and PEEK for xenon scintillation light (178 nm), conducted at the University of Michigan using the Michigan Xenon Detector (MiX) will be presented. The University of Michigan, LZ Collaboration, The US Department of Energy.

43 CFR 12.4 - Information collection requirements.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 43 Public Lands: Interior 1 2010-10-01 2010-10-01 false Information collection requirements. 12.4 Section 12.4 Public Lands: Interior Office of the Secretary of the Interior ADMINISTRATIVE AND AUDIT... Principles for Assistance Programs § 12.4 Information collection requirements. Information collections in...

Magnetization transfer from laser-polarized xenon to protons located in the hydrophobic cavity of the wheat nonspecific lipid transfer protein

PubMed Central

Landon, Céline; Berthault, Patrick; Vovelle, Françoise; Desvaux, Hervé

2001-01-01

Nonspecific lipid transfer protein from wheat is studied by liquid-state NMR in the presence of xenon. The gas–protein interaction is indicated by the dependence of the protein proton chemical shifts on the xenon pressure and formally confirmed by the first observation of magnetization transfer from laser-polarized xenon to the protein protons. Twenty-six heteronuclear nOes have allowed the characterization of four interaction sites inside the wheat ns-LTP cavity. Their locations are in agreement with the variations of the chemical shifts under xenon pressure and with solvation simulations. The richness of the information obtained by the noble gas with a nuclear polarization multiplied by ∼12,000 makes this approach based on dipolar cross-relaxation with laser-polarized xenon promising for probing protein hydrophobic pockets at ambient pressure. PMID:11274467

Constraints on Nucleosynthesis from Xenon Isotopes in Presolar Material

NASA Astrophysics Data System (ADS)

Gilmour, J. D.; Turner, G.

2007-03-01

By applying theoretical constraints to three-dimensional fits of xenon isotope data from presolar grains, we show that they strongly suggest a nucleosynthesis process that produces ``r-process'' isotopes without producing s-process isotopes (128Xe, 130Xe) and without producing the conventional r-process isotope 136Xe. It is one of three distinct nucleosynthetic sources that are necessary and sufficient to explain the gross variation in xenon isotopic data across all presolar material. The other source contributing r-process isotopes is responsible for the heavy isotope signature identified in nanodiamonds, which is also present in presolar SiC, and is associated with light isotope enrichment. The relative enrichments of heavy and light isotopes in this component in nanodiamonds and SiC grains are different, implying that the parent nucleosynthetic processes are not inextricably linked. Because minor variations in the isotopic compositions of xenon trapped in nanodiamonds show that two distinct sites contributed nanodiamonds to the early solar system within the average grain lifetime, it is suggested that Type IIa supernovae (SNe IIa) are not the source of the nanodiamonds. The s-process signature derived is consistent with that derived from mixing lines between grain subpopulations for isotopes on the s-process path. This implies that a pure end-member is present in the grains (although not approached in analyses). Our approach is more general and provides a less restrictive set of numerical constraints to be satisfied by proposed theoretical treatments of nucleosynthesis.

Improved xenon lamp for solar simulators: A concept

NASA Technical Reports Server (NTRS)

Schmidt, L. F.

1974-01-01

Short-arc xenon lamp proposes to produce more uniform solar output. With this lamp, both axes of sensors can be tested with same setup. Lamp includes cathode with conical tip and annular anode. Annulus is supported by angled projection to avoid interference with passage of light generated by arc.

42 CFR 124.701 - Applicability.

Code of Federal Regulations, 2010 CFR

2010-10-01

... Construction Act of 1968, 82 Stat. 631 (Pub. L. 90-457); (3) The Appalachian Regional Development Act of 1965... 42 Public Health 1 2010-10-01 2010-10-01 false Applicability. 124.701 Section 124.701 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES HEALTH RESOURCES DEVELOPMENT...

Search for magnetic inelastic dark matter with XENON100

NASA Astrophysics Data System (ADS)

Aprile, E.; Aalbers, J.; Agostini, F.; Alfonsi, M.; Amaro, F. D.; Anthony, M.; Arneodo, F.; Barrow, P.; Baudis, L.; Bauermeister, B.; Benabderrahmane, M. L.; Berger, T.; Breur, P. A.; Brown, A.; Brown, E.; Bruenner, S.; Bruno, G.; Budnik, R.; Bütikofer, L.; Calvén, J.; Cardoso, J. M. R.; Cervantes, M.; Cichon, D.; Coderre, D.; Colijn, A. P.; Conrad, J.; Cussonneau, J. P.; Decowski, M. P.; de Perio, P.; Di Gangi, P.; Di Giovanni, A.; Diglio, S.; Eurin, G.; Fei, J.; Ferella, A. D.; Fieguth, A.; Franco, D.; Fulgione, W.; Gallo Rosso, A.; Galloway, M.; Gao, F.; Garbini, M.; Geis, C.; Goetzke, L. W.; Greene, Z.; Grignon, C.; Hasterok, C.; Hogenbirk, E.; Itay, R.; Kaminsky, B.; Kessler, G.; Kish, A.; Landsman, H.; Lang, R. F.; Lellouch, D.; Levinson, L.; Lin, Q.; Lindemann, S.; Lindner, M.; Lombardi, F.; Lopes, J. A. M.; Manfredini, A.; Maris, I.; Marrodán Undagoitia, T.; Masbou, J.; Massoli, F. V.; Masson, D.; Mayani, D.; Messina, M.; Micheneau, K.; Molinario, A.; Murra, M.; Naganoma, J.; Ni, K.; Oberlack, U.; Pakarha, P.; Pelssers, B.; Persiani, R.; Piastra, F.; Pienaar, J.; Pizzella, V.; Piro, M.-C.; Plante, G.; Priel, N.; Rauch, L.; Reichard, S.; Reuter, C.; Rizzo, A.; Rosendahl, S.; Rupp, N.; dos Santos, J. M. F.; Sartorelli, G.; Scheibelhut, M.; Schindler, S.; Schreiner, J.; Schumann, M.; Scotto Lavina, L.; Selvi, M.; Shagin, P.; Silva, M.; Simgen, H.; Sivers, M. v.; Stein, A.; Thers, D.; Tiseni, A.; Trinchero, G.; Tunnell, C.; Vargas, M.; Wang, H.; Wei, Y.; Weinheimer, C.; Wulf, J.; Ye, J.; Zhang, Y.

2017-10-01

We present the first search for dark matter-induced delayed coincidence signals in a dual-phase xenon time projection chamber, using the 224.6 live days of the XENON100 science run II. This very distinct signature is predicted in the framework of magnetic inelastic dark matter which has been proposed to reconcile the modulation signal reported by the DAMA/LIBRA collaboration with the null results from other direct detection experiments. No candidate event has been found in the region of interest and upper limits on the WIMP's magnetic dipole moment are derived. The scenarios proposed to explain the DAMA/LIBRA modulation signal by magnetic inelastic dark matter interactions of WIMPs with masses of 58.0 GeV/c2 and 122.7 GeV/c2 are excluded at 3.3 σ and 9.3 σ, respectively.

7 CFR 1.24 - Preservation of records.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 7 Agriculture 1 2010-01-01 2010-01-01 false Preservation of records. 1.24 Section 1.24 Agriculture Office of the Secretary of Agriculture ADMINISTRATIVE REGULATIONS Official Records § 1.24 Preservation of records. Agencies shall preserve all correspondence relating to the requests it receives under this...

7 CFR 1.24 - Preservation of records.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 7 Agriculture 1 2013-01-01 2013-01-01 false Preservation of records. 1.24 Section 1.24 Agriculture Office of the Secretary of Agriculture ADMINISTRATIVE REGULATIONS Official Records § 1.24 Preservation of records. Agencies shall preserve all correspondence relating to the requests it receives under this...

Pretreatment with xenon protected immature rabbit heart from ischaemia/reperfusion injury by opening of the mitoKATP channel.

PubMed

Li, Qian; Lian, Chunwei; Zhou, Ronghua; Li, Tao; Xiang, Xujin; Liu, Bin

2013-04-01

The noble gas anaesthetic, xenon has previously been shown to protect the adult myocardium from ischaemia/reperfusion (I/R) injury, however its effect on immature myocardium is unclear. The aim of this study was to investigate the effect of xenon on the isolated immature heart. Isolated, immature (2-3weeks old) New Zealand rabbit hearts were perfused with Krebs-Henseleit buffer via Langendorff-mode. After 20min of baseline equilibration, hearts were pretreated with 75% xenon, 75% xenon+100μM diazoxide, or 75% xenon+100μM 5-hydroxydecanoate, and then subjected to 1h of global ischaemia and 3h of reperfusion. Pretreatment with 75% xenon significantly improved cardiac function (P<0.01 vs. the I/R group, respectively), limited myocardial infarct size (20.83±2.16%, P<0.01 vs. 35.82±2.14% of the I/R group), reduced cardiac enzyme release (CK-MB, 1.00±0.19IU/L, P<0.01 vs. 0.44±0.14IU/L of the I/R group; LDH, 6.15±1.06IU/L P<0.01 vs. 3.49±0.37IU/L of the I/R group) and decreased apoptosis (6.17±0.56%, P<0.01 vs. 11.31±0.93% of the I/R group). In addition, the mitochondrial structure changes caused by I/R injury were largely prevented by 75% xenon pretreatment (1.37±0.16, P<0.01 vs. 2.32±0.13 of the I/R group). The mitochondrial adenosine triphosphate-sensitive potassium (mitoKATP) channel opener diazoxide did not influence the effect of xenon, but the specific mitoKATP channel blocker 5-hydroxydecanoate completely abolished this effect. Our study demonstrated that pretreatment with 75% xenon protected immature heart from I/R injury, and this protection was probably mediated by preservation of myocardial mitochondria and opening of mitoKATP channel. Copyright © 2012 Australian and New Zealand Society of Cardiac and Thoracic Surgeons (ANZSCTS) and the Cardiac Society of Australia and New Zealand (CSANZ). Published by Elsevier B.V. All rights reserved.

Crystallographic studies with xenon and nitrous oxide provide evidence for protein-dependent processes in the mechanisms of general anesthesia.

PubMed

Abraini, Jacques H; Marassio, Guillaume; David, Helene N; Vallone, Beatrice; Prangé, Thierry; Colloc'h, Nathalie

2014-11-01

The mechanisms by which general anesthetics, including xenon and nitrous oxide, act are only beginning to be discovered. However, structural approaches revealed weak but specific protein-gas interactions. To improve knowledge, we performed x-ray crystallography studies under xenon and nitrous oxide pressure in a series of 10 binding sites within four proteins. Whatever the pressure, we show (1) hydrophobicity of the gas binding sites has a screening effect on xenon and nitrous oxide binding, with a threshold value of 83% beyond which and below which xenon and nitrous oxide, respectively, binds to their sites preferentially compared to each other; (2) xenon and nitrous oxide occupancies are significantly correlated respectively to the product and the ratio of hydrophobicity by volume, indicating that hydrophobicity and volume are binding parameters that complement and oppose each other's effects; and (3) the ratio of occupancy of xenon to nitrous oxide is significantly correlated to hydrophobicity of their binding sites. These data demonstrate that xenon and nitrous oxide obey different binding mechanisms, a finding that argues against all unitary hypotheses of narcosis and anesthesia, and indicate that the Meyer-Overton rule of a high correlation between anesthetic potency and solubility in lipids of general anesthetics is often overinterpreted. This study provides evidence that the mechanisms of gas binding to proteins and therefore of general anesthesia should be considered as the result of a fully reversible interaction between a drug ligand and a receptor as this occurs in classical pharmacology.

Timing of distant flap pedicle division using xenon 133 clearance

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

Snelling, C.F.; Poomee, A.; Sutherland, J.B.

1980-09-01

Clearance of intradermally injected xenon 133 was used to measure blood flow in distant flaps in humans with the donor pedicle temporarily clamped just prior to division. All 18 flaps with a blood flow of 0.5 ml per 100 gm of tissue per minute or more survived completely after separation. Of 7 with lesser flow, 3 underwent marginal necrosis adjacent to the line of division and 4 survived entirely. Xenon 133 washout does permit quantitative evaluation of blood flow, and since it is a clean isotope, it appears superior to sodium 24 and technetium 99m, which have been used inmore » a similar manner. The test is proposed as an adjunct to clinical judgment in timing pedicle division.« less

31 CFR 33.124 - State reporting requirements.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 31 Money and Finance: Treasury 1 2012-07-01 2012-07-01 false State reporting requirements. 33.124 Section 33.124 Money and Finance: Treasury Office of the Secretary of the Treasury WAIVERS FOR STATE INNOVATION § 33.124 State reporting requirements. (a) Quarterly reports. A State must submit quarterly...

31 CFR 33.124 - State reporting requirements.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 31 Money and Finance: Treasury 1 2013-07-01 2013-07-01 false State reporting requirements. 33.124 Section 33.124 Money and Finance: Treasury Office of the Secretary of the Treasury WAIVERS FOR STATE INNOVATION § 33.124 State reporting requirements. (a) Quarterly reports. A State must submit quarterly...

31 CFR 33.124 - State reporting requirements.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 31 Money and Finance: Treasury 1 2014-07-01 2014-07-01 false State reporting requirements. 33.124 Section 33.124 Money and Finance: Treasury Office of the Secretary of the Treasury WAIVERS FOR STATE INNOVATION § 33.124 State reporting requirements. (a) Quarterly reports. A State must submit quarterly...

Post-Test Inspection of Nasa's Evolutionary Xenon Thruster Long Duration Test Hardware: Ion Optics

NASA Technical Reports Server (NTRS)

Soulas, George C.; Shastry, Rohit

2016-01-01

A Long Duration Test (LDT) was initiated in June 2005 as a part of NASAs Evolutionary Xenon Thruster (NEXT) service life validation approach. Testing was voluntarily terminated in February 2014, with the thruster accumulating 51,184 hours of operation, processing 918 kg of xenon propellant, and delivering 35.5 MN-s of total impulse. This presentation will present the post-test inspection results to date for the thrusters ion optics.

Solvothermal synthesis and structural characterization of a three-dimensional metal organic polymer [NaZn(1,2,4-BTC)] (1,2,4-BTC=1,2,4-benzenetricarboxylate)

NASA Astrophysics Data System (ADS)

Wang, Lei; Shi, Zhan; Li, Guanghua; Fan, Yong; Fu, Wensheng; Feng, Shouhua

2004-01-01

A new three-dimensional metal-organic polymer, [NaZn(1,2,4-BTC)] (where 1,2,4-BTC=1,2,4-benzenetricarboxylate), has been prepared under solvothermal conditions and characterized by single crystal X-ray diffraction. The compound crystallizes in the monoclinic space group P2 1/ c, with cell parameters: a=9.7706(4) Å, b=12.3549(5) Å, c=6.8897(3) Å, β=91.640(2)°, V=831.35(6) Å 3 and Z=4. In the three-dimensional structure of the compound, each Zn atom is five-coordinated in distorted trigonal bipyramidal geometry, while the sixfold coordination of Na corresponds to a slightly distorted triangular prism. The organic ligand, 1,2,4-BTC, shows a novel and unprecedented coordination mode: 11 bonds to 10 metals with each carboxylate function exhibiting different linkages. It remains stable when desolvated and when heated up to 410 °C.

Comparison of the effects of xenon and sevoflurane anaesthesia on leucocyte function in surgical patients: a randomized trial.

PubMed

Fahlenkamp, A V; Coburn, M; Rossaint, R; Stoppe, C; Haase, H

2014-02-01

While most anaesthetics are known to suppress immune reactions, data from experimental studies indicate the enhancement of reactivity to inflammatory stimulators under xenon treatment. We investigated the effect of xenon anaesthesia on leucocyte function in surgical patients. We performed a subgroup analysis of subjects undergoing xenon or sevoflurane anaesthesia in a randomized clinical trial. After oral premedication with midazolam, two separate blood samples were obtained from subjects undergoing elective abdominal surgery, directly before and 1 h after induction of anaesthesia. General anaesthesia was maintained with either 60% xenon or 2.0% sevoflurane in 30% O2. Leucocyte count, phagocytotic function, and pro-inflammatory cytokine release after ex vivo lipopolysaccharide (LPS) stimulation were determined. Except for lymphocyte numbers, leucocyte subpopulations did not differ between the groups. Phagocytosis and oxidative burst of granulocytes were reduced in both groups after 1 h of anaesthesia, whereas monocytes were not affected. Pro-inflammatory cytokine release in response to LPS was not affected. In vivo, xenon and sevoflurane anaesthesia did not have a pro-inflammatory effect, at least in combination with the types of surgery performed in this study. Notably, the impact of xenon anaesthesia did not differ significantly from sevoflurane anaesthesia with regard to leucocyte function. However, an underestimation of treatment effects due to limited sample sizes cannot be fully excluded.

10 CFR 501.124 - Decision and order.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 10 Energy 4 2010-01-01 2010-01-01 false Decision and order. 501.124 Section 501.124 Energy DEPARTMENT OF ENERGY (CONTINUED) ALTERNATE FUELS ADMINISTRATIVE PROCEDURES AND SANCTIONS Requests for Stay § 501.124 Decision and order. (a) OFE will issue an order granting or denying the petition for a stay...

13 CFR 124.303 - What is termination?

Code of Federal Regulations, 2010 CFR

2010-01-01

... 13 Business Credit and Assistance 1 2010-01-01 2010-01-01 false What is termination? 124.303 Section 124.303 Business Credit and Assistance SMALL BUSINESS ADMINISTRATION 8(a) BUSINESS DEVELOPMENT... § 124.303 What is termination? (a) SBA may terminate the participation of a concern in the 8(a) BD...

Partial-wave analysis for positronium-xenon collisions in the ultralow-energy region

NASA Astrophysics Data System (ADS)

Shibuya, Kengo; Saito, Haruo

2018-05-01

We propose a method to convert measured positronium annihilation rates in gaseous xenon into total and differential cross sections of positronium-xenon collisions in an ultralow-energy region of less than 80 meV where their experimental determinations as functions of the positronium kinetic energy are extremely difficult. This method makes it possible to determine not only the s -wave collisional parameters but also the p -wave and d -wave parameters. We have found a small positive value of the scattering length, A0=2.06 ±0.10 a0 , which indicates that the positronium-xenon interaction in this energy region is repulsive and suggests that it is dominated by the scattering amplitude of the positron rather than that of the electron. An extrapolation of the analytical result into the experimentally inaccessible energy regions from 80 meV to 1.0 eV indicates that there should not be a Ramsauer-Townsend minimum but rather a peak in the total cross section at an energy of approximately 0.4 eV.

Worsening respiratory function in mechanically ventilated intensive care patients: feasibility and value of xenon-enhanced dual energy CT.

PubMed

Hoegl, Sandra; Meinel, Felix G; Thieme, Sven F; Johnson, Thorsten R C; Eickelberg, Oliver; Zwissler, Bernhard; Nikolaou, Konstantin

2013-03-01

To evaluate the feasibility and incremental diagnostic value of xenon-enhanced dual-energy CT in mechanically ventilated intensive care patients with worsening respiratory function. The study was performed in 13 mechanically ventilated patients with severe pulmonary conditions (acute respiratory distress syndrome (ARDS), n=5; status post lung transplantation, n=5; other, n=3) and declining respiratory function. CT scans were performed using a dual-source CT scanner at an expiratory xenon concentration of 30%. Both ventilation images (Xe-DECT) and standard CT images were reconstructed from a single CT scan. Findings were recorded for Xe-DECT and standard CT images separately. Ventilation defects on xenon images were matched to morphological findings on standard CT images and incremental diagnostic information of xenon ventilation images was recorded if present. Mean xenon consumption was 2.95 l per patient. No adverse events occurred under xenon inhalation. In the visual CT analysis, the Xe-DECT ventilation defects matched with pathologic changes in lung parenchyma seen in the standard CT images in all patients. Xe-DECT provided additional diagnostic findings in 4/13 patients. These included preserved ventilation despite early pneumonia (n=1), more confident discrimination between a large bulla and pneumothorax (n=1), detection of an airway-to-pneumothorax fistula (n=1) and exclusion of a suspected airway-to-mediastinum fistula (n=1). In all 4 patients, the additional findings had a substantial impact on patients' management. Xenon-enhanced DECT is safely feasible and can add relevant diagnostic information in mechanically ventilated intensive care patients with worsening respiratory function. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

Detection of Alpha Particles and Low Energy Gamma Rays by Thermo-Bonded Micromegas in Xenon Gas

NASA Astrophysics Data System (ADS)

Wei, Yuehuan; Guan, Liang; Zhang, Zhiyong; Lin, Qing; Wang, Xiaolian; Ni, Kaixuan; Zhao, Tianchi

2013-08-01

Micromegas is a type of micro-pattern gaseous detector currently under R&D for applications in rare event search experiments. Here we report the performance of a Micromegas structure constructed with a micromesh thermo-bonded to a readout plane, motivated by its potential application in two-phase xenon detectors for dark matter and neutrinoless double beta decay experiments. The study is carried out in pure xenon at room temperature. Measurements with alpha particles from the Americium-241 source showed that gas gains larger than 200 can be obtained at xenon pressure up to 3 atm. Gamma rays down to 8 keV were observed with such a device.

Xenon decreases cell migration and secretion of a pro-angiogenesis factor in breast adenocarcinoma cells: comparison with sevoflurane.

PubMed

Ash, S A; Valchev, G I; Looney, M; Ni Mhathuna, A; Crowley, P D; Gallagher, H C; Buggy, D J

2014-07-01

While volatile agents have been implicated in metastasis-enhancing effects on cancer cells, the effects of xenon are unknown. We investigated xenon- and sevoflurane-mediated effects on migration and expression of angiogenesis biomarkers in human breast adenocarcinoma cells. MDA-MB-231 and MCF-7 cells were exposed to xenon 70% with O2 25%, CO2 5%; control gas containing O2 25%, CO2 5%, N2 70%; or sevoflurane 2.5 vol% administered in O2 60%, N2 37%, or control gas. Cell viability was determined by the MTT assay. Migration at 24 h was determined using the Oris™ Cell Migration Assay. Secretion of angiogenesis factors was measured using a membrane-based immunoassay array. Xenon reduced MDA-MB-231 migration to 59 (13%) after 1-h exposure (P=0.02), 64 (10%) after 3 h (P=0.01), and 71 (9%) after 5 h (P=0.04) compared with control gas, without affecting viability. Similarly, MCF-7 migration was significantly reduced at all timepoints [to 58 (12%) at 1 h, 65 (12%) at 3 h, and 65% (12%) at 5 h]. Sevoflurane did not affect migration when delivered in control gas. Glycine, an N-methyl-d-aspartate receptor co-agonist, antagonized the effects of xenon on migration. Expression of the pro-angiogenesis factor regulated on activation, normal T cell expressed and secreted (RANTES) was reduced in conditioned medium from xenon-exposed MDA-MB-231 cells compared with cells exposed to either control gas or sevoflurane [mean dot density 2.0 (0.2) compared with 3.0 (0.1) and 3.1 (0.3), respectively (P=0.02)]. Xenon, but not sevoflurane, inhibited migration in both oestrogen receptor positive and negative breast adenocarcinoma cells. Furthermore, xenon decreased release of the pro-angiogenic factor RANTES from MDA-MB-231 cells. © The Author [2014]. Published by Oxford University Press on behalf of the British Journal of Anaesthesia. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Inhaled Xenon Attenuates Myocardial Damage in Comatose Survivors of Out-of-Hospital Cardiac Arrest: The Xe-Hypotheca Trial.

PubMed

Arola, Olli; Saraste, Antti; Laitio, Ruut; Airaksinen, Juhani; Hynninen, Marja; Bäcklund, Minna; Ylikoski, Emmi; Wennervirta, Johanna; Pietilä, Mikko; Roine, Risto O; Harjola, Veli-Pekka; Niiranen, Jussi; Korpi, Kirsi; Varpula, Marjut; Scheinin, Harry; Maze, Mervyn; Vahlberg, Tero; Laitio, Timo

2017-11-28

The authors previously reported that inhaled xenon combined with hypothermia attenuates brain white matter injury in comatose survivors of out-of-hospital cardiac arrest (OHCA). A pre-defined secondary objective was to assess the effect of inhaled xenon on myocardial ischemic damage in the same study population. A total of 110 comatose patients who had experienced OHCA from a cardiac cause were randomized to receive either inhaled xenon (40% end-tidal concentration) combined with hypothermia (33°C) for 24 h (n = 55; xenon group) or hypothermia treatment alone (n = 55; control group). Troponin-T levels were measured at hospital admission, and at 24 h, 48 h, and 72 h post-cardiac arrest. All available cases were analyzed for troponin-T release. Troponin-T measurements were available from 54 xenon patients and 54 control patients. The baseline characteristics did not differ significantly between the groups. After adjustments for age, sex, study site, primary coronary percutaneous intervention (PCI), and norepinephrine dose, the mean ± SD post-arrival incremental change of the ln-transformed troponin-T at 72 h was 0.79 ± 1.54 in the xenon group and 1.56 ± 1.38 in the control group (adjusted mean difference -0.66; 95% confidence interval: -1.16 to -0.16; p = 0.01). The effect of xenon on the change in the troponin-T values did not differ in patients with or without PCI or in those with a diagnosis of ST-segment elevation myocardial infarction (group by PCI or ST-segment elevation myocardial infarction interaction effect; p = 0.86 and p = 0.71, respectively). Among comatose survivors of OHCA, in comparison with hypothermia alone, inhaled xenon combined with hypothermia suggested a less severe myocardial injury as demonstrated by the significantly reduced release of troponin-T. Copyright © 2017 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

The MicroRNA miR-124 Promotes Neuronal Differentiation by Triggering Brain-Specific Alternative Pre-mRNA Splicing

PubMed Central

Makeyev, Eugene V.; Zhang, Jiangwen; Carrasco, Monica A.; Maniatis, Tom

2011-01-01

SUMMARY Both microRNAs and alternative pre-mRNA splicing have been implicated in the development of the nervous system (NS), but functional interactions between these two pathways are poorly understood. We demonstrate that the neuron-specific microRNA miR-124 directly targets PTBP1 (PTB/hnRNP I) mRNA, which encodes a global repressor of alternative pre-mRNA splicing in nonneuronal cells. Among the targets of PTBP1 is a critical cassette exon in the pre-mRNA of PTBP2 (nPTB/brPTB/PTBLP), an NS-enriched PTBP1 homolog. When this exon is skipped, PTBP2 mRNA is subject to nonsense-mediated decay (NMD). During neuronal differentiation, miR-124 reduces PTBP1 levels, leading to the accumulation of correctly spliced PTBP2 mRNA and a dramatic increase in PTBP2 protein. These events culminate in the transition from non-NS to NS-specific alternative splicing patterns. We also present evidence that miR-124 plays a key role in the differentiation of progenitor cells to mature neurons. Thus, miR-124 promotes NS development, at least in part by regulating an intricate network of NS-specific alternative splicing. PMID:17679093

Increased miR-124-3p in microglial exosomes following traumatic brain injury inhibits neuronal inflammation and contributes to neurite outgrowth via their transfer into neurons.

PubMed

Huang, Shan; Ge, Xintong; Yu, Jinwen; Han, Zhaoli; Yin, Zhenyu; Li, Ying; Chen, Fanglian; Wang, Haichen; Zhang, Jianning; Lei, Ping

2018-01-01

Neuronal inflammation is the characteristic pathologic change of acute neurologic impairment and chronic traumatic encephalopathy after traumatic brain injury (TBI). Inhibiting the excessive inflammatory response is essential for improving the neurologic outcome. To clarify the regulatory mechanism of microglial exosomes on neuronal inflammation in TBI, we focused on studying the impact of microglial exosomal miRNAs on injured neurons in this research. We used a repetitive (r)TBI mouse model and harvested the injured brain extracts from the acute to the chronic phase of TBI to treat cultured BV2 microglia in vitro The microglial exosomes were collected for miRNA microarray analysis, which showed that the expression level of miR-124-3p increased most apparently in the miRNAs. We found that miR-124-3p promoted the anti-inflamed M2 polarization in microglia, and microglial exosomal miR-124-3p inhibited neuronal inflammation in scratch-injured neurons. Further, the mammalian target of rapamycin (mTOR) signaling was implicated as being involved in the regulation of miR-124-3p by Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway analyses. Using the mTOR activator MHY1485 we confirmed that the inhibitory effect of exosomal miR-124-3p on neuronal inflammation was exerted by suppressing the activity of mTOR signaling. PDE4B was predicted to be the target gene of miR-124-3p by pathway analysis. We proved that it was directly targeted by miR-124-3p with a luciferase reporter assay. Using a PDE4B overexpressed lentivirus transfection system, we suggested that miR-124-3p suppressed the activity of mTOR signaling mainly through inhibiting the expression of PDE4B. In addition, exosomal miR-124-3p promoted neurite outgrowth after scratch injury, characterized by an increase on the number of neurite branches and total neurite length, and a decreased expression on RhoA and neurodegenerative proteins [Aβ-peptide and p-Tau]. It also improved the neurologic outcome and

Search for magnetic inelastic dark matter with XENON100

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

Aprile, E.; Anthony, M.; Aalbers, J.

2017-10-01

We present the first search for dark matter-induced delayed coincidence signals in a dual-phase xenon time projection chamber, using the 224.6 live days of the XENON100 science run II. This very distinct signature is predicted in the framework of magnetic inelastic dark matter which has been proposed to reconcile the modulation signal reported by the DAMA/LIBRA collaboration with the null results from other direct detection experiments. No candidate event has been found in the region of interest and upper limits on the WIMP's magnetic dipole moment are derived. The scenarios proposed to explain the DAMA/LIBRA modulation signal by magnetic inelasticmore » dark matter interactions of WIMPs with masses of 58.0 GeV/c{sup 2} and 122.7 GeV/c{sup 2} are excluded at 3.3 σ and 9.3 σ, respectively.« less

Incipient triple point for adsorbed xenon monolayers: Pt(111) versus graphite substrates

NASA Astrophysics Data System (ADS)

Novaco, Anthony D.; Bruch, L. W.; Bavaresco, Jessica

2015-04-01

Simulation evidence of an incipient triple point is reported for xenon submonolayers adsorbed on the (111) surface of platinum. This is in stark contrast to the "normal" triple point found in simulations and experiments for xenon on the basal plane surface of graphite. The motions of the atoms in the surface plane are treated with standard 2D "NVE" molecular dynamics simulations using modern interactions. The simulation evidence strongly suggests an incipient triple point in the 120 -150 K range for adsorption on the Pt (111) surface while the adsorption on graphite shows a normal triple point at about 100 K.

Long term spectral irradiance measurements of a 1000-watt xenon arc lamp

NASA Technical Reports Server (NTRS)

Schneider, W. E.

1974-01-01

Spectral irradiance measurements over the range of 200 to 1060 nm were made on a 1000-watt xenon arc lamp over a period of 1500 hours. Four sets of measurements were made after periods of 70, 525, 1000, and 1500 hours of operation. The lamp (Hanovia Compact Xenon Arc Lamp) was mounted in the NASA Solar Irradiation System. When used in the System, the lamp is used as the radiating source for six test stations. Measurements were made of both the longterm stability (or variation of spectral irradiance as a function of time) and the actual spectral irradiance incident on the test specimen.

Measurement of Xenon Viscosity as a Function of Low Temperature and Pressure

NASA Technical Reports Server (NTRS)

Grisnik, Stanley P.

1998-01-01

The measurement of xenon gas viscosity at low temperatures (175-298 K) and low pressures (350 torr-760 torr) has been performed in support of Hall Thruster testing at NASA Lewis Research Center. The measurements were taken using the capillary flow technique. Viscosity measurements were repeatable to within 3%. The results in this paper are in agreement with data from Hanley and Childs and suggest that the data from Clarke and Smith is approximately 2% low. There are no noticeable pressure effects on xenon absolute viscosity for the pressure range from 350 torr to 760 torr.

Xenon ion propulsion for orbit transfer

NASA Technical Reports Server (NTRS)

Rawlin, V. K.; Patterson, M. J.; Gruber, R. P.

1990-01-01

For more than 30 years, NASA has conducted an ion propulsion program which has resulted in several experimental space flight demonstrations and the development of many supporting technologies. Technologies appropriate for geosynchronous stationkeeping, earth-orbit transfer missions, and interplanetary missions are defined and evaluated. The status of critical ion propulsion system elements is reviewed. Electron bombardment ion thrusters for primary propulsion have evolved to operate on xenon in the 5 to 10 kW power range. Thruster efficiencies of 0.7 and specific impulse values of 4000 s were documented. The baseline thruster currently under development by NASA LeRC includes ring-cusp magnetic field plasma containment and dished two-grid ion optics. Based on past experience and demonstrated simplifications, power processors for these thrusters should have approximately 500 parts, a mass of 40 kg, and an efficiency near 0.94. Thrust vector control, via individual thruster gimbals, is a mature technology. High pressure, gaseous xenon propellant storage and control schemes, using flight qualified hardware, result in propellant tankage fractions between 0.1 and 0.2. In-space and ground integration testing has demonstrated that ion propulsion systems can be successfully integrated with their host spacecraft. Ion propulsion system technologies are mature and can significantly enhance and/or enable a variety of missions in the nation's space propulsion program.

Chronic obstructive pulmonary disease: quantitative and visual ventilation pattern analysis at xenon ventilation CT performed by using a dual-energy technique.

PubMed

Park, Eun-Ah; Goo, Jin Mo; Park, Sang Joon; Lee, Hyun Ju; Lee, Chang Hyun; Park, Chang Min; Yoo, Chul-Gyu; Kim, Jong Hyo

2010-09-01

To evaluate the potential of xenon ventilation computed tomography (CT) in the quantitative and visual analysis of chronic obstructive pulmonary disease (COPD). This study was approved by the institutional review board. After informed consent was obtained, 32 patients with COPD underwent CT performed before the administration of xenon, two-phase xenon ventilation CT with wash-in (WI) and wash-out (WO) periods, and pulmonary function testing (PFT). For quantitative analysis, results of PFT were compared with attenuation parameters from prexenon images and xenon parameters from xenon-enhanced images in the following three areas at each phase: whole lung, lung with normal attenuation, and low-attenuating lung (LAL). For visual analysis, ventilation patterns were categorized according to the pattern of xenon attenuation in the area of structural abnormalities compared with that in the normal-looking background on a per-lobe basis: pattern A consisted of isoattenuation or high attenuation in the WI period and isoattenuation in the WO period; pattern B, isoattenuation or high attenuation in the WI period and high attenuation in the WO period; pattern C, low attenuation in both the WI and WO periods; and pattern D, low attenuation in the WI period and isoattenuation or high attenuation in the WO period. Among various attenuation and xenon parameters, xenon parameters of the LAL in the WO period showed the best inverse correlation with results of PFT (P < .0001). At visual analysis, while emphysema (which affected 99 lobes) commonly showed pattern A or B, airway diseases such as obstructive bronchiolitis (n = 5) and bronchiectasis (n = 2) and areas with a mucus plug (n = 1) or centrilobular nodules (n = 5) showed pattern D or C. WI and WO xenon ventilation CT is feasible for the simultaneous regional evaluation of structural and ventilation abnormalities both quantitatively and qualitatively in patients with COPD. (c) RSNA, 2010.

40 CFR 61.124 - Recordkeeping requirements.

Code of Federal Regulations, 2014 CFR

2014-07-01

... Section 61.124 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) NATIONAL EMISSION STANDARDS FOR HAZARDOUS AIR POLLUTANTS National Emission Standards for Radionuclide Emissions From Elemental Phosphorus Plants § 61.124 Recordkeeping requirements. The owner or...

Heat capacity of xenon adsorbed on nanobundle grooves

NASA Astrophysics Data System (ADS)

Chishko, K. A.; Sokolova, E. S.

2016-02-01

A model of a one-dimensional nonideal gas in an external transverse force field is used to interpret the experimentally observed thermodynamic properties of xenon deposited in grooves on the surface of carbon nanobundles. A nonideal gas model with pairwise interactions is not entirely adequate for describing dense adsorbates (at low temperatures), but makes it easy to account for the exchange of particles between the 1D adsorbate and the 3D atmosphere, which is an important factor at intermediate (on the order of 35 K for xenon) and, especially, high (˜100 K) temperatures. In this paper, we examine a 1D real gas taking only the one-dimensional Lennard-Jones interaction into account, but under exact equilibrium with respect to the number of particles between the 1D adsorbate and the 3D atmosphere of the measurement cell. The low-temperature branch of the specific heat is fitted independently by an elastic chain model so as to obtain the best agreement between theory and experiment over the widest possible region, beginning at zero temperature. The gas approximation sets in after temperatures for which the phonon specific heat of the chain essentially transforms to a one-dimensional equipartition law. Here the basic parameters of both models can be chosen so that the heat capacity C(T) of the chain transforms essentially continuously into the corresponding curve for the gas approximation. Thus, it can be expected that an adequate interpretation of the real temperature dependences of the specific heat of low-dimensionality atomic adsorbates can be obtained through a reasonable combination of the phonon and gas approximations. The main parameters of the gas approximation (such as the desorption energy) obtained by fitting the theory to experiments on the specific heat of xenon correlate well with published data.

Target identification, lead optimization and antitumor evaluation of some new 1,2,4-triazines as c-Met kinase inhibitors.

PubMed

El-Wakil, Marwa H; Ashour, Hayam M; Saudi, Manal N; Hassan, Ahmed M; Labouta, Ibrahim M

2017-08-01

In silico target fishing approach using PharmMapper server identified c-Met kinase as the selective target for our previously synthesized compound NCI 748494/1. This approach was validated by in vitro kinase assay which showed that NCI 748494/1 possessed promising inhibitory activity against c-Met kinase (IC 50 =31.70μM). Assessment of ADMET profiling, drug-likeness, drug score as well as docking simulation for the binding pose of that compound in the active site of c-Met kinase domain revealed that NCI 748494/1 could be considered as a promising drug lead. Based on target identification and validation, it was observed that there is structure similarity between NCI 748494/1 and the reported type II c-Met kinase inhibitor BMS-777607. Optimization of our lead NCI 748494/1 furnished newly synthesized 1,2,4-triazine derivatives based on well-established structure-activity relationships, whereas three compounds namely; 4d, 7a and 8c displayed excellent in vitro cytotoxicity against three c-Met addicted cancer cell lines; A549 (lung adenocarcinoma), HT-29 (colon cancer) and MKN-45 (gastric carcinoma); with IC 50 values in the range 0.01-1.86µM. In vitro c-Met kinase assay showed 8c to possess the highest c-Met kinase inhibition profile (IC 50 =4.31µM). Docking of the active compounds in c-Met kinase active site revealed strong binding interactions comparable to the lead NCI 748494/1 and BMS-777607, suggesting that c-Met inhibition is very likely to be the mechanism of the antitumor effect of these derivatives. Copyright © 2017 Elsevier Inc. All rights reserved.

Feasibility and safety of xenon compared with sevoflurane anaesthesia in coronary surgical patients: a randomized controlled pilot study.

PubMed

Stoppe, C; Fahlenkamp, A V; Rex, S; Veeck, N C; Gozdowsky, S C; Schälte, G; Autschbach, R; Rossaint, R; Coburn, M

2013-09-01

To date, only limited data exist about the use of xenon as an anaesthetic agent in patients undergoing cardiac surgery. The favourable cardio- and neuroprotective properties of xenon might attenuate postoperative complications, improve outcome, and reduce the incidence of delirium. Thus, the aims of this study were to investigate the feasibility and safety of balanced xenon anaesthesia in patients undergoing cardiac surgery and to gather pilot data for a future randomized multicentre study. Thirty patients undergoing elective coronary artery bypass grafting were enrolled in this randomized, single-blind controlled trial. They were randomized to receive balanced general anaesthesia with either xenon (45-50 vol%) or sevoflurane (1-1.4 vol%). The primary outcome was the occurrence of adverse events (AEs). Secondary outcome parameters were feasibility criteria (bispectral index, perioperative haemodynamic, and respiratory profile) and safety parameters (dosage of study treatments, renal function, intraoperative blood loss, need for inotropic support, regional cerebral tissue oxygenation). Furthermore, at predefined time points, systemic and pulmonary haemodynamics were assessed by the use of a pulmonary artery catheter. There were no patient characteristic differences between the groups. Patients undergoing xenon anaesthesia did not differ with respect to the incidence of AE (6 vs 8, P=0.464) compared with the sevoflurane group. No differences were detected regarding secondary feasibility and safety criteria. The haemodynamic and respiratory profile was comparable between the treatment groups. Balanced xenon anaesthesia is feasible and safe compared with sevoflurane anaesthesia in patients undergoing coronary artery bypass surgery. Acronym CARDIAX: A pre- and post-coronary artery bypass graft implantation disposed application of xenon. Clinical trial registration ClinicalTrials.gov: NCT01285271; EudraCT-number: 2010-023942-63. Approved by the ethics committee 'Ethik

Modeling ARRM Xenon Tank Pressurization Using 1D Thermodynamic and Heat Transfer Equations

NASA Technical Reports Server (NTRS)

Gilligan, Patrick; Tomsik, Thomas

2016-01-01

As a first step in understanding what ground support equipment (GSE) is required to provide external cooling during the loading of 5,000 kg of xenon into 4 aluminum lined composite overwrapped pressure vessels (COPVs), a modeling analysis was performed using Microsoft Excel. The goals of the analysis were to predict xenon temperature and pressure throughout loading at the launch facility, estimate the time required to load one tank, and to get an early estimate of what provisions for cooling xenon might be needed while the tanks are being filled. The model uses the governing thermodynamic and heat transfer equations to achieve these goals. Results indicate that a single tank can be loaded in about 15 hours with reasonable external coolant requirements. The model developed in this study was successfully validated against flight and test data. The first data set is from the Dawn mission which also utilizes solar electric propulsion with xenon propellant, and the second is test data from the rapid loading of a hydrogen cylindrical COPV. The main benefit of this type of model is that the governing physical equations using bulk fluid solid temperatures can provide a quick and accurate estimate of the state of the propellant throughout loading which is much cheaper in terms of computational time and licensing costs than a Computation Fluid Dynamics (CFD) analysis while capturing the majority of the thermodynamics and heat transfer.

Impact of pulsed xenon ultraviolet light on hospital-acquired infection rates in a community hospital.

PubMed

Vianna, Pedro G; Dale, Charles R; Simmons, Sarah; Stibich, Mark; Licitra, Carmelo M

2016-03-01

The role of contaminated environments in the spread of hospital-associated infections has been well documented. This study reports the impact of a pulsed xenon ultraviolet no-touch disinfection system on infection rates in a community care facility. This study was conducted in a community hospital in Southern Florida. Beginning November 2012, a pulsed xenon ultraviolet disinfection system was implemented as an adjunct to traditional cleaning methods on discharge of select rooms. The technology uses a xenon flashlamp to generate germicidal light that damages the DNA of organisms in the hospital environment. The device was implemented in the intensive care unit (ICU), with a goal of using the pulsed xenon ultraviolet system for disinfecting all discharges and transfers after standard cleaning and prior to occupation of the room by the next patient. For all non-ICU discharges and transfers, the pulsed xenon ultraviolet system was only used for Clostridium difficile rooms. Infection data were collected for methicillin-resistant Staphylococcus aureus, C difficile, and vancomycin-resistant Enterococci (VRE). The intervention period was compared with baseline using a 2-sample Wilcoxon rank-sum test. In non-ICU areas, a significant reduction was found for C difficile. There was a nonsignificant decrease in VRE and a significant increase in methicillin-resistant S aureus. In the ICU, all infections were reduced, but only VRE was significant. This may be because of the increased role that environment plays in the transmission of this pathogen. Overall, there were 36 fewer infections in the whole facility and 16 fewer infections in the ICU during the intervention period than would have been expected based on baseline data. Implementation of pulsed xenon ultraviolet disinfection is associated with significant decreases in facility-wide and ICU infection rates. These outcomes suggest that enhanced environmental disinfection plays a role in the risk mitigation of hospital

(124)I-iodopyridopyrimidinone for PET of Abl kinase-expressing tumors in vivo.

PubMed

Doubrovin, Mikhail; Kochetkova, Tatiana; Santos, Elmer; Veach, Darren R; Smith-Jones, Peter; Pillarsetty, Nagavarakishore; Balatoni, Julius; Bornmann, William; Gelovani, Juri; Larson, Steven M

2010-01-01

Because of the recent development of an iodopyridopyrimidinone Abl protein kinase inhibitor (PKI), (124)I-SKI-212230 ((124)I-SKI230), we investigated the feasibility of a PET-based molecular imaging method for the direct visualization of Abl kinase expression and PKI treatment. In vitro pharmacokinetic properties, including specific and nonspecific binding of (124)I-SKI230 to its Abl kinase target and interaction with other PKIs, were assessed in cell-free medium and chronic myelogenous leukemia (CML) cells overexpressing BCR-Abl (K562), in comparison with BT-474 cells that are low in Abl expression. In a xenograft tumor model, we assessed the in vivo pharmacokinetics of (124)I-SKI230 using PET and postmortem tissue sampling. We also tested a paradigm of (124)I-SKI230 PET after treatment of the animal with a dose of Abl-specific PKI for the monitoring of the tumor response. In vitro studies confirmed that SKI230 binds to Abl kinase with nanomolar affinity, that selective uptake occurs in cell lines known to express Abl kinase, that RNAi knock-down supports specificity of cellular uptake due to Abl kinase, and that imatinib, an archetype Abl PKI, completely displaces SKI230. With SKI230, we obtained successful in vivo PET of Abl-expressing human tumors in a nude rat. We were also able to demonstrate evidence of substrate inhibition of in vivo radiotracer uptake in the xenograft tumor after treatment of the animal as a model of PKI treatment monitoring. These results support the hypothesis that molecular imaging using PET will be useful for the study of in vivo pharmacodynamics of Abl PKI molecular therapy in humans.

Boltzmann expansion in a radiofrequency conical helicon thruster operating in xenon and argon

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

Charles, C.; Boswell, R.; Takahashi, K.

2013-06-03

A low pressure ({approx}0.5 mTorr in xenon and {approx}1 mTorr in argon) Boltzmann expansion is experimentally observed on axis within a magnetized (60 to 180 G) radiofrequency (13.56 MHz) conical helicon thruster for input powers up to 900 W using plasma parameters measured with a Langmuir probe. The axial forces, respectively, resulting from the electron and magnetic field pressures are directly measured using a thrust balance for constant maximum plasma pressure and show a higher fuel efficiency for argon compared to xenon.

Effects of pulmonary static inflation with 50% xenon on oxygen impairment during cardiopulmonary bypass for stanford type A acute aortic dissection

PubMed Central

Jin, Mu; Yang, Yanwei; Pan, Xudong; Lu, Jiakai; Zhang, Zhiquan; Cheng, Weiping

2017-01-01

Abstract Background: The goal of this study was to investigate the effects of pulmonary static inflation with 50% xenon on postoperative oxygen impairment during cardiopulmonary bypass (CPB) for Stanford type A acute aortic dissection (AAD). Methods: This prospective single-center nonrandomized controlled clinical trial included 100 adult patients undergoing surgery for Stanford type A AAD at an academic hospital in China. Fifty subjects underwent pulmonary static inflation with 50% oxygen from January 2013 to January 2014, and 50 underwent inflation with 50% xenon from January 2014 to December 2014. During CPB, the lungs were inflated with either 50% xenon (xenon group) or 50% oxygen (control group) to maintain an airway pressure of 5 cm H2O. The primary outcome was oxygenation index (OI) value after intubation, and 10 minutes and 6 hours after the operation. The second outcome was cytokine and reactive oxygen species levels after intubation and 10 minutes, 6 hours, and 24 hours after the operation. Results: Patients treated with xenon had lower OI levels compared to the control group before surgery (P = 0.002); however, there was no difference in postoperative values between the 2 groups. Following surgery, mean maximal OI values decreased by 18.8% and 33.8%, respectively, in the xenon and control groups. After surgery, the levels of interleukin-6 (IL-6), tumor necrosis factor alpha, and thromboxane B2 decreased by 23.5%, 9.1%, and 30.2%, respectively, in the xenon group, but increased by 10.8%, 26.2%, and 26.4%, respectively, in the control group. Moreover, IL-10 levels increased by 28% in the xenon group and decreased by 7.5% in the control group. There were significant time and treatment-time interaction effects on methane dicarboxylic aldehyde (P = 0.000 and P = 0.050, respectively) and myeloperoxidase (P = 0.000 and P = 0.001 in xenon and control groups, respectively). There was no difference in hospital mortality and 1-year

Pulsed xenon flashlamp device for the treatment of psoriasis

NASA Astrophysics Data System (ADS)

Baumgardner, Jonathan M.; Hennings, David R.; Johnston, Thomas F., Jr.; Taylor, Eric

2003-06-01

We present our research into a pulsed xenon lamp source for the treatment of psoriasis and other skin disorders. Various filtering techniques, lamp configurations, power supply configurations and delivery systems are discussed. Comparisons are made to existing treatment modalities. Cryogen cooling of the treatment site is discussed.

Performance characteristics of ring-cusp thrusters with xenon propellant

NASA Technical Reports Server (NTRS)

Patterson, M. J.

1986-01-01

The performance characteristics and operating envelope of several 30-cm ring-cusp ion thrusters with xenon propellant were investigated. Results indicate a strong performance dependence on the discharge chamber boundary magnetic fields and resultant distribution of electron currents. Significant improvements in discharge performance over J-series divergent-field thrusters were achieved for large throttling ranges, which translate into reduced cathode emission currents and reduced power dissipation which should be of significant benefit for operation at thruster power levels in excess of 10 kW. Mass spectrometry of the ion beam was documented for both the ring-cusp and J-series thrusters with xenon propellant for determination of overall thruster efficiency, and lifetime. Based on the lower centerline values of doubly charged ions in the ion beam and the lower operating discharge voltage, the screen grid erosion rate of the ring-cusp thruster is expected to be lower than the divergent-field J-series thruster by a factor of 2.

Performance characteristics of ring-cusp thrusters with xenon propellant

NASA Technical Reports Server (NTRS)

Patterson, M. J.

1986-01-01

The performance characteristics and operating envelope of several 30-cm ring-cusp ion thrusters with xenon propellant were investigated. Results indicate a strong performance dependence on the discharge chamber boundary magnetic fields and resultant distribution of electron currents. Significant improvements in discharge performance over J-series divergent-field thrusters were achieved for large throttling ranges, which translate into reduced cathode emission currents and reduced power dissipation which should be of significant benefit for operation at thruster power levels in excess of 10 kW. Mass spectrometer of the ion beam was documented for both the ring-cusp and J-series thrusters with xenon propellant for determination of overall thruster efficiency, and lifetime. Based on the lower centerline values of doubly charged ions in the ion beam and the lower operating discharge voltage, the screen grid erosion rate of the ring-cusp thruster is expected to be lower than the divergent-field J-series thruster by a factor of 2.

In situ measurement of atmospheric krypton and xenon on Mars with Mars Science Laboratory

DOE PAGES

Conrad, P. G.; Malespin, C. A.; Franz, H. B.; ...

2016-11-01

Mars Science Laboratory's Sample Analysis at Mars (SAM) investigation has measured all of the stable isotopes of the heavy noble gases krypton and xenon in the martian atmosphere, in situ, from the Curiosity Rover at Gale Crater, Mars. Previous knowledge of martian atmospheric krypton and xenon isotope ratios has been based upon a combination of the Viking mission's krypton and xenon detections and measurements of noble gas isotope ratios in martian meteorites. But, the meteorite measurements reveal an impure mixture of atmospheric, mantle, and spallation contributions. The xenon and krypton isotopic measurements reported here include the complete set of stablemore » isotopes, unmeasured by Viking. Our new results generally agree with Mars meteorite measurements but also provide a unique opportunity to identify various non-atmospheric heavy noble gas components in the meteorites. Kr isotopic measurements define a solar-like atmospheric composition, but deviating from the solar wind pattern at 80Kr and 82Kr in a manner consistent with contributions originating from neutron capture in Br. The Xe measurements suggest an intriguing possibility that isotopes lighter than 132Xe have been enriched to varying degrees by spallation and neutron capture products degassed to the atmosphere from the regolith, and a model is constructed to explore this possibility. Such a spallation component, but, is not apparent in atmospheric Xe trapped in the glassy phases of martian meteorites.« less

In situ measurement of atmospheric krypton and xenon on Mars with Mars Science Laboratory

NASA Astrophysics Data System (ADS)

Conrad, P. G.; Malespin, C. A.; Franz, H. B.; Pepin, R. O.; Trainer, M. G.; Schwenzer, S. P.; Atreya, S. K.; Freissinet, C.; Jones, J. H.; Manning, H.; Owen, T.; Pavlov, A. A.; Wiens, R. C.; Wong, M. H.; Mahaffy, P. R.

2016-11-01

Mars Science Laboratory's Sample Analysis at Mars (SAM) investigation has measured all of the stable isotopes of the heavy noble gases krypton and xenon in the martian atmosphere, in situ, from the Curiosity Rover at Gale Crater, Mars. Previous knowledge of martian atmospheric krypton and xenon isotope ratios has been based upon a combination of the Viking mission's krypton and xenon detections and measurements of noble gas isotope ratios in martian meteorites. However, the meteorite measurements reveal an impure mixture of atmospheric, mantle, and spallation contributions. The xenon and krypton isotopic measurements reported here include the complete set of stable isotopes, unmeasured by Viking. The new results generally agree with Mars meteorite measurements but also provide a unique opportunity to identify various non-atmospheric heavy noble gas components in the meteorites. Kr isotopic measurements define a solar-like atmospheric composition, but deviating from the solar wind pattern at 80Kr and 82Kr in a manner consistent with contributions originating from neutron capture in Br. The Xe measurements suggest an intriguing possibility that isotopes lighter than 132Xe have been enriched to varying degrees by spallation and neutron capture products degassed to the atmosphere from the regolith, and a model is constructed to explore this possibility. Such a spallation component, however, is not apparent in atmospheric Xe trapped in the glassy phases of martian meteorites.

Pulse-shape discrimination and energy resolution of a liquid-argon scintillator with xenon doping

NASA Astrophysics Data System (ADS)

Wahl, C. G.; Bernard, E. P.; Lippincott, W. H.; Nikkel, J. A.; Shin, Y.; McKinsey, D. N.

2014-06-01

Liquid-argon scintillation detectors are used in fundamental physics experiments and are being considered for security applications. Previous studies have suggested that the addition of small amounts of xenon dopant improves performance in light or signal yield, energy resolution, and particle discrimination. In this study, we investigate the detector response for xenon dopant concentrations from 9 ± 5 ppm to 1100 ± 500 ppm xenon (by weight) in 6 steps. The 3.14-liter detector uses tetraphenyl butadiene (TPB) wavelength shifter with dual photomultiplier tubes and is operated in single-phase mode. Gamma-ray-interaction signal yield of 4.0 ± 0.1 photoelectrons/keV improved to 5.0 ± 0.1 photoelectrons/keV with dopant. Energy resolution at 662 keV improved from (4.4 ± 0.2)% (σ) to (3.5 ± 0.2)% (σ) with dopant. Pulse-shape discrimination performance degraded greatly at the first addition of dopant, slightly improved with additional additions, then rapidly improved near the end of our dopant range, with performance becoming slightly better than pure argon at the highest tested dopant concentration. Some evidence of reduced neutron scintillation efficiency with increasing dopant concentration was observed. Finally, the waveform shape outside the TPB region is discussed, suggesting that the contribution to the waveform from xenon-produced light is primarily in the last portion of the slow component.

In Situ Measurement of Atmospheric Krypton and Xenon on Mars with Mars Science Laboratory

NASA Technical Reports Server (NTRS)

Conrad, P. G.; Malespin, C. A.; Franz, H. B.; Pepin, R. O.; Trainer, M. G.; Schwenzer, S. P.; Atreya, S. K.; Freissinet, C.; Jones, J. H.; Manning, H.;

In situ measurement of atmospheric krypton and xenon on Mars with Mars Science Laboratory

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

Conrad, P. G.; Malespin, C. A.; Franz, H. B.

Mars Science Laboratory's Sample Analysis at Mars (SAM) investigation has measured all of the stable isotopes of the heavy noble gases krypton and xenon in the martian atmosphere, in situ, from the Curiosity Rover at Gale Crater, Mars. Previous knowledge of martian atmospheric krypton and xenon isotope ratios has been based upon a combination of the Viking mission's krypton and xenon detections and measurements of noble gas isotope ratios in martian meteorites. But, the meteorite measurements reveal an impure mixture of atmospheric, mantle, and spallation contributions. The xenon and krypton isotopic measurements reported here include the complete set of stablemore » isotopes, unmeasured by Viking. Our new results generally agree with Mars meteorite measurements but also provide a unique opportunity to identify various non-atmospheric heavy noble gas components in the meteorites. Kr isotopic measurements define a solar-like atmospheric composition, but deviating from the solar wind pattern at 80Kr and 82Kr in a manner consistent with contributions originating from neutron capture in Br. The Xe measurements suggest an intriguing possibility that isotopes lighter than 132Xe have been enriched to varying degrees by spallation and neutron capture products degassed to the atmosphere from the regolith, and a model is constructed to explore this possibility. Such a spallation component, but, is not apparent in atmospheric Xe trapped in the glassy phases of martian meteorites.« less

40 CFR 124.33 - Information repository.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 21 2010-07-01 2010-07-01 false Information repository. 124.33 Section... FOR DECISIONMAKING Specific Procedures Applicable to RCRA Permits § 124.33 Information repository. (a... basis, for an information repository. When assessing the need for an information repository, the...

42 CFR 124.509 - Reporting requirements.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 42 Public Health 1 2010-10-01 2010-10-01 false Reporting requirements. 124.509 Section 124.509 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES HEALTH RESOURCES DEVELOPMENT MEDICAL FACILITY CONSTRUCTION AND MODERNIZATION Reasonable Volume of Uncompensated Services to Persons...

Prospects for dark matter detection with inelastic transitions of xenon

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

McCabe, Christopher

2016-05-16

Dark matter can scatter and excite a nucleus to a low-lying excitation in a direct detection experiment. This signature is distinct from the canonical elastic scattering signal because the inelastic signal also contains the energy deposited from the subsequent prompt de-excitation of the nucleus. A measurement of the elastic and inelastic signal will allow a single experiment to distinguish between a spin-independent and spin-dependent interaction. For the first time, we characterise the inelastic signal for two-phase xenon detectors in which dark matter inelastically scatters off the {sup 129}Xe or {sup 131}Xe isotope. We do this by implementing a realistic simulationmore » of a typical tonne-scale two-phase xenon detector and by carefully estimating the relevant background signals. With our detector simulation, we explore whether the inelastic signal from the axial-vector interaction is detectable with upcoming tonne-scale detectors. We find that two-phase detectors allow for some discrimination between signal and background so that it is possible to detect dark matter that inelastically scatters off either the {sup 129}Xe or {sup 131}Xe isotope for dark matter particles that are heavier than approximately 100 GeV. If, after two years of data, the XENON1T search for elastic scattering nuclei finds no evidence for dark matter, the possibility of ever detecting an inelastic signal from the axial-vector interaction will be almost entirely excluded.« less

Studies of K-Ar dating and xenon from extinct radioactivities in breccia 14318; implications for early lunar history

NASA Technical Reports Server (NTRS)

Reynolds, J. H.; Alexander, E. C., Jr.; Davis, P. K.; Srinivasan, B.

1974-01-01

The lunar breccia 14318 is one of three Apollo-14 breccias containing substantial amounts of parentless xenon from the spontaneous fission of extinct Pu-244. The argon and xenon contained in this breccia were studied by stepwise heating of pristine and neutron-irradiated samples. The isotopic composition of xenon from fission, determined by an improved method, is shown to be from Pu-244. Concentrations of this fissiogenic xenon are in substantial excess (15-fold) of what could be produced by spontaneous fission of U-238. The breccia is found to contain abundant trapped argon with an Ar-40/Ar-36 ratio of roughly 14. Otherwise, the argon is radiogenic and gives a convincing K-Ar age of 3.69 plus or minus 0.09 b.y. by the stepwise Ar-40/Ar-39 method, nearly in agreement with ages for other Apollo-14 breccias.

Post-Test Inspection of NASA's Evolutionary Xenon Thruster Long-Duration Test Hardware: Discharge Chamber

NASA Technical Reports Server (NTRS)

Shastry, Rohit; Soulas, George C.

2016-01-01

NASAs Evolutionary Xenon Thruster (NEXT) Long-Duration Test (LDT) is part of the comprehensive service life assessment of the NEXT thruster. The test was voluntarily terminated in April 2014 after accumulating 51,184 hours of high voltage operation, processing 918 kg of xenon, and delivering 35.5 MN-s of total impulse. This presentation covers the post-test inspection of the thruster hardware, in particular of the discharge chamber and other miscellaneous components such as propellant isolators and electrical cabling.

Performance analysis of photoresistor and phototransistor for automotive’s halogen and xenon bulbs light output

NASA Astrophysics Data System (ADS)

Rammohan, A.; Kumar, C. Ramesh

2017-11-01

Illumination of any light is measured using a different kind of calibrated equipment’s available in the market such as a goniometer, spectral radiometer, photometer, Lux meter and camera based systems which directly display the illumination of automotive headlights light distribution in the unit of lux, foot-candles, lumens/sq. ft. and Lambert etc., In this research, we dealt with evaluating the photo resistor or Light Dependent Resistor (LDR) and phototransistor whether it is useful for sensing light patterns of Automotive Halogen and Xenon bulbs. The experiments are conducted during night hours under complete dark space. We have used the headlamp setup available in TATA SUMO VICTA vehicle in the Indian market and conducted the experiments separately for Halogen and Xenon bulbs under low and high beam operations at various degrees and test points within ten meters of distance. Also, we have compared the light intensity of halogen and xenon bulbs to prove the highest light intensity between halogen and Xenon bulbs. After doing a rigorous test with these two sensors it is understood both are good to sensing beam pattern of automotive bulbs and even it is good if we use an array of sensors or a mixed combination of sensors for measuring illumination purposes under perfect calibrations.

Molecular oxygen migration through the xenon docking sites of human hemoglobin in the R-state.

PubMed

Lepeshkevich, Sergei V; Gilevich, Syargey N; Parkhats, Marina V; Dzhagarov, Boris M

2016-09-01

A nanosecond laser flash-photolysis technique was used to study bimolecular and geminate molecular oxygen (O2) rebinding to tetrameric human hemoglobin and its isolated α and β chains in buffer solutions equilibrated with 1atm of air and up to 25atm of xenon. Xenon binding to the isolated α chains and to the α subunits within tetrameric hemoglobin was found to cause a decrease in the efficiency of O2 escape by a factor of ~1.30 and 3.3, respectively. A kinetic model for O2 dissociation, rebinding, and migration through two alternative pathways in the hemoglobin subunits was introduced and discussed. It was shown that, in the isolated α chains and α subunits within tetrameric hemoglobin, nearly one- and two-third escaping molecules of O2 leave the protein via xenon docking sites, respectively. The present experimental data support the idea that O2 molecule escapes from the β subunits mainly through the His(E7) gate, and show unambiguously that, in the α subunits, in addition to the direct E7 channel, there is at least one alternative escape route leading to the exterior via the xenon docking sites. Copyright © 2016 Elsevier B.V. All rights reserved.

Comparison of recovery parameters for xenon versus other inhalation anesthetics: systematic review and meta-analysis.

PubMed

Hou, Bingzong; Li, Fujing; Ou, Shanshan; Yang, Lukun; Zhou, Shaopeng

2016-03-01

To summarize and evaluate the available data describing the recovery parameters of xenon anesthesia. Systematic review and meta-analysis. Anesthesia for elective surgeries. Systematic review of randomized controlled trials (RCTs) from databases including Medline (1964-2013), the Cochrane Central Register of Controlled Trials (CENTRAL, 1990-2012), and Google Scholar (1966-2013). Inhalation of xenon or other anesthetics was administered in elective surgery. Recovery parameters (time to recovery, alertness/sedation scale scores at "eye opening," bispectral index at "reaction on demand," time to extubation, and time to orientation). Eleven RCTs (N = 661 patients) met the inclusion criteria. Recovery from xenon anesthesia was significantly faster in terms of the time to eye opening (mean difference [MD], -4.18 minutes; 95% confidence interval [CI], -5.03 to -3.32 minutes; P < .00001), the time to reaction on demand (MD, -5.35 minutes; 95% CI, -6.59 to -4.11 minutes; P < .00001), the time to extubation (MD, -4.49 minutes; 95% CI, -5.40 to -3.58 minutes; P < .00001), and the time to orientation (MD, -4.99 minutes; 95% CI, -6.45 to -3.52 minutes; P < .00001). This meta-analysis confirmed that recovery from xenon anesthesia is faster than other inhalation anesthesia. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

9 CFR 354.124 - Quarantine of diseased rabbits.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 9 Animals and Animal Products 2 2012-01-01 2012-01-01 false Quarantine of diseased rabbits. 354.124 Section 354.124 Animals and Animal Products FOOD SAFETY AND INSPECTION SERVICE, DEPARTMENT OF... Procedures; Ante-Mortem Inspections § 354.124 Quarantine of diseased rabbits. If live rabbits, which are...

9 CFR 354.124 - Quarantine of diseased rabbits.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 9 Animals and Animal Products 2 2013-01-01 2013-01-01 false Quarantine of diseased rabbits. 354.124 Section 354.124 Animals and Animal Products FOOD SAFETY AND INSPECTION SERVICE, DEPARTMENT OF... Procedures; Ante-Mortem Inspections § 354.124 Quarantine of diseased rabbits. If live rabbits, which are...

9 CFR 354.124 - Quarantine of diseased rabbits.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 9 Animals and Animal Products 2 2014-01-01 2014-01-01 false Quarantine of diseased rabbits. 354.124 Section 354.124 Animals and Animal Products FOOD SAFETY AND INSPECTION SERVICE, DEPARTMENT OF... Procedures; Ante-Mortem Inspections § 354.124 Quarantine of diseased rabbits. If live rabbits, which are...

28 CFR 0.124 - United States Parole Commission.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 28 Judicial Administration 1 2013-07-01 2013-07-01 false United States Parole Commission. 0.124 Section 0.124 Judicial Administration DEPARTMENT OF JUSTICE ORGANIZATION OF THE DEPARTMENT OF JUSTICE United States Parole Commission § 0.124 United States Parole Commission. The U.S. Parole Commission is...

28 CFR 0.124 - United States Parole Commission.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 28 Judicial Administration 1 2011-07-01 2011-07-01 false United States Parole Commission. 0.124 Section 0.124 Judicial Administration DEPARTMENT OF JUSTICE ORGANIZATION OF THE DEPARTMENT OF JUSTICE United States Parole Commission § 0.124 United States Parole Commission. The U.S. Parole Commission is...

28 CFR 0.124 - United States Parole Commission.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 28 Judicial Administration 1 2012-07-01 2012-07-01 false United States Parole Commission. 0.124 Section 0.124 Judicial Administration DEPARTMENT OF JUSTICE ORGANIZATION OF THE DEPARTMENT OF JUSTICE United States Parole Commission § 0.124 United States Parole Commission. The U.S. Parole Commission is...

28 CFR 0.124 - United States Parole Commission.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 28 Judicial Administration 1 2014-07-01 2014-07-01 false United States Parole Commission. 0.124 Section 0.124 Judicial Administration DEPARTMENT OF JUSTICE ORGANIZATION OF THE DEPARTMENT OF JUSTICE United States Parole Commission § 0.124 United States Parole Commission. The U.S. Parole Commission is...

28 CFR 0.124 - United States Parole Commission.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 28 Judicial Administration 1 2010-07-01 2010-07-01 false United States Parole Commission. 0.124 Section 0.124 Judicial Administration DEPARTMENT OF JUSTICE ORGANIZATION OF THE DEPARTMENT OF JUSTICE United States Parole Commission § 0.124 United States Parole Commission. The U.S. Parole Commission is...

32 CFR 701.124 - PA self assessments/inspections.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 32 National Defense 5 2014-07-01 2014-07-01 false PA self assessments/inspections. 701.124 Section 701.124 National Defense Department of Defense (Continued) DEPARTMENT OF THE NAVY UNITED STATES NAVY... OF THE NAVY DOCUMENTS AFFECTING THE PUBLIC DON Privacy Program § 701.124 PA self assessments...

32 CFR 701.124 - PA self assessments/inspections.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 32 National Defense 5 2012-07-01 2012-07-01 false PA self assessments/inspections. 701.124 Section 701.124 National Defense Department of Defense (Continued) DEPARTMENT OF THE NAVY UNITED STATES NAVY... OF THE NAVY DOCUMENTS AFFECTING THE PUBLIC DON Privacy Program § 701.124 PA self assessments...

32 CFR 701.124 - PA self assessments/inspections.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 32 National Defense 5 2011-07-01 2011-07-01 false PA self assessments/inspections. 701.124 Section 701.124 National Defense Department of Defense (Continued) DEPARTMENT OF THE NAVY UNITED STATES NAVY... OF THE NAVY DOCUMENTS AFFECTING THE PUBLIC DON Privacy Program § 701.124 PA self assessments...

32 CFR 701.124 - PA self assessments/inspections.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 32 National Defense 5 2013-07-01 2013-07-01 false PA self assessments/inspections. 701.124 Section 701.124 National Defense Department of Defense (Continued) DEPARTMENT OF THE NAVY UNITED STATES NAVY... OF THE NAVY DOCUMENTS AFFECTING THE PUBLIC DON Privacy Program § 701.124 PA self assessments...

32 CFR 701.124 - PA self assessments/inspections.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 32 National Defense 5 2010-07-01 2010-07-01 false PA self assessments/inspections. 701.124 Section 701.124 National Defense Department of Defense (Continued) DEPARTMENT OF THE NAVY UNITED STATES NAVY... OF THE NAVY DOCUMENTS AFFECTING THE PUBLIC DON Privacy Program § 701.124 PA self assessments...

Measurement of light and charge yield of low-energy electronic recoils in liquid xenon

NASA Astrophysics Data System (ADS)

Goetzke, L. W.; Aprile, E.; Anthony, M.; Plante, G.; Weber, M.

2017-11-01

The dependence of the light and charge yield of liquid xenon on the applied electric field and recoil energy is important for dark matter detectors using liquid xenon time projections chambers. Few measurements have been made of this field dependence at recoil energies less than 10 keV. In this paper, we present results of such measurements using a specialized detector. Recoil energies are determined via the Compton coincidence technique at four drift fields relevant for liquid xenon dark matter detectors: 0.19, 0.48, 1.02, and 2.32 kV /cm . Mean recoil energies down to 1 keV were measured with unprecedented precision. We find that the charge and light yield are anticorrelated above ˜3 keV and that the field dependence becomes negligible below ˜6 keV . However, below 3 keV, we find a charge yield significantly higher than expectation and a reconstructed energy deviating from linearity.

17 CFR 256.124 - Other investments.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 17 Commodity and Securities Exchanges 3 2010-04-01 2010-04-01 false Other investments. 256.124... COMPANY ACT OF 1935 2. Investments § 256.124 Other investments. This account shall include the cost or current value of investments, whichever is less, in securities, club memberships, associations, life...

17 CFR 256.124 - Other investments.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 17 Commodity and Securities Exchanges 3 2011-04-01 2011-04-01 false Other investments. 256.124... COMPANY ACT OF 1935 2. Investments § 256.124 Other investments. This account shall include the cost or current value of investments, whichever is less, in securities, club memberships, associations, life...

14 CFR 1260.124 - Program income.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 14 Aeronautics and Space 5 2011-01-01 2010-01-01 true Program income. 1260.124 Section 1260.124 Aeronautics and Space NATIONAL AERONAUTICS AND SPACE ADMINISTRATION GRANTS AND COOPERATIVE AGREEMENTS Uniform... and Trademark Amendments (35 U.S.C. 18) apply to inventions made under an experimental, developmental...

Xenon/remifentanil anesthesia protects against adverse effects of losartan on hemodynamic challenges induced by anesthesia and acute blood loss.

PubMed

Francis, Roland C E; Philippi-Höhne, Claudia; Klein, Adrian; Pickerodt, Philipp A; Reyle-Hahn, Matthias S; Boemke, Willehad

2010-12-01

The authors aimed to test the hypothesis that xenon anesthesia limits adverse hypotensive effects of losartan during acute hemorrhage. In six conscious unsedated Beagle dogs, the systemic and pulmonary circulation were monitored invasively, and two subsequent 60-min hypotensive challenges were performed by (a) induction (propofol) and maintenance of anesthesia with isoflurane/remifentanil or xenon/remifentanil and by (b) subsequent hemorrhage (20 mL kg⁻¹ within 5 min) from a central vein. The same amount of blood was retransfused 1 h after hemorrhage. Experiments were performed with or without acute angiotensin II receptor subtype 1 blockade by i.v. losartan (100 μg·kg⁻¹·min⁻¹) starting 45 min before induction of anesthesia. Four experiments were performed in each individual dog. Xenon/remifentanil anesthesia provided higher baseline mean arterial blood pressure (85 ± 6 mmHg) than isoflurane/remifentanil anesthesia (67 ± 3 mmHg). In losartan-treated animals, isoflurane/remifentanil caused significant hypotension (42 ± 4 mmHg for isoflurane/remifentanil vs. 71 ± 6 mmHg for xenon/remifentanil). Independent of losartan, hemorrhage did not induce any further reduction of mean arterial blood pressure or cardiac output in either group. Spontaneous hemodynamic recovery was observed in all groups before retransfusion was started. Losartan did not alter the adrenaline, noradrenaline, and vasopressin response to acute hemorrhage. Losartan potentiates hypotension induced by isoflurane/remifentanil anesthesia but does not affect the hemodynamic stability during xenon/remifentanil anesthesia. Losartan does not deteriorate the hemodynamic adaptation to hemorrhage of 20 mL kg⁻¹ during xenon/remifentanil and isoflurane/remifentanil anesthesia. Therefore, xenon/remifentanil anesthesia protects against circulatory side effects of losartan pretreatment and thus may afford safer therapeutic use of losartan during acute hemorrhage.