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Xenon Isotopes (1):
Recent article
Xenon Isotopes
Abstract
We have incorporated approximately 125 xenon sensor molecules in the interior of an MS2 viral capsid, conferring multivalency and other properties of the viral capsid to the sensor molecule. The resulting signal amplification facilitates the detection of sensor at 0.7 pM, the lowest to date for any...
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PMID: 20392049
PDF is available here.
PDF is available here.
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Chemical Communications (46)16 2010
Abstract
High-pressure (129)Xe NMR has been used to monitor in real time the self-assembly of reverse water-in-supercritical carbon dioxide micelles in the absence of shear, without the need for sensitivity enhancement techniques such as hyperpolarization.
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PMID: 20369204
PDF is available here.
PDF is available here.
Abstract
Injections of (129)Xe-saturated saline were well tolerated and produced a strong gas-phase (129)Xe signal in the airspaces that resulted from (129)Xe transport through the pulmonary circulation and diffusion across the blood-gas barrier. After a single injection, the emerging (129)Xe gas could be de...
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PMID: 19703880
PDF is available here.
PDF is available here.
Abstract
The (13)C NMR signal of acetic acid 1-(13)C-AcH is enhanced by polarization transfer from hyperpolarized (129)Xe using a thermal mixing procedure. 1-(13)C-AcH acid and hyperpolarized (129)Xe are mixed as gases to disperse (129)Xe in the acetic acid. The mixture is frozen with liquid N(2) at 0.5 T. T...
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PMID: 19655895
PDF is available here.
PDF is available here.
Abstract
A water-soluble triacetic acid cryptophane-A derivative (TAAC) was synthesized and determined by isothermal titration calorimetry and fluorescence quenching assay to have a xenon association constant of 33,000 M(-1) at 293 K, which is the largest value measured for any host molecule to date. Fluores...
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PMID: 19239271
PDF is available here.
PDF is available here.
Abstract
The production of high-purity (123)I that utilizes an isotopically enriched (124)Xe target and bombardment with 30 MeV protons, through the reactions (124)Xe (p, 2n) (123)Cs-->(123)Xe-->(123)I and (124)Xe (p, pn) (123)Xe-->(123)I, is described. The aim of this work was to improve the production para...
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PMID: 18515122
PDF is available here.
PDF is available here.
Abstract
We demonstrate a real-time in vivo delivery of HP (129)Xe mixture to rats, a capability we now routinely use for setting frequency, transmitter gain, shimming, testing pulse sequences, scout imaging, and spectroscopy. Compared to images acquired using conventional fully concentrated (129)Xe, real-ti...
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PMID: 18581406
PDF is available here.
PDF is available here.
Physical Review Letters (100)25 2008
Abstract
We study the signal transfer onto a reservoir of unbound HP xenon by gating the residence time of the nuclei in the cage through the temperature-dependant exchange rate. Temperature changes larger than approximately 0.6 K are detectable as an altered reservoir signal. The temperature response is adj...
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PMID: 18643704
PDF is available here.
PDF is available here.
Abstract
Academic Radiology (15)6 2008
Abstract
We present new technology offering (129)Xe production rates with order-of-magnitude improvement over existing systems, to liter per hour at 50% polarization. Human lung imaging studies with xenon, initially limited by the modest quantity and quality of hyperpolarized gas available, can now be perfor...
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PMID: 18486005
PDF is available here.
PDF is available here.
Academic Radiology (15)6 2008
Abstract
We investigated the ability of (129)Xe to measure the alveolar surface area per unit volume of gas, S(A)/V(gas)....
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PMID: 18486008
PDF is available here.
PDF is available here.
Pediatric Radiology (38 Suppl 2) 2008
Abstract
Abstract
The SNR of gas- and dissolved-phase images were 28.9 +/- 5.2 and 12.0 +/- 2.0, respectively, using the 70% xenon gas mixture, while they were 22.9 +/- 4.8 and 6.8 +/- 0.6, using the 3% mixture. The ADC of xenon using the 3% xenon gas mixture was approximately 1.5 times higher than that using the 70%...
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PMID: 18383257
PDF is available here.
PDF is available here.
NMR in Biomedicine (21)3 2008
Abstract
We developed a multi-pulse protocol during the washout of (129)Xe from the brain. Afterwards, we applied an SNR threshold theory to both the multi-pulse protocol and an existing two-pulse protocol. The two protocols yielded mean +/- SD HP (129)Xe T(1) values in the rat brain of 15.3 +/- 1.2 and 16.2...
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PMID: 17557274
PDF is available here.
PDF is available here.
Abstract
Despite the importance of the tobacco smoke particulate matter in the lungs to the etiology of pulmonary disease in cigarette smokers, little is currently known about the spatial distribution of particle deposition or the persistence of the resulting deposits in humans, and no satisfactory technique...
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PMID: 17826938
PDF is available here.
PDF is available here.
Abstract
We used a continuous-flow hyperpolarizing (CF-HP) system to acquire gas- and dissolved-phase 129Xe images from mouse lung, employing standard gradient echo sequence equipped with chemical shift selective excitation and 90 degrees flip angle. The character of non-recoverable HP magnetization enabled...
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PMID: 18603837
PDF is available here.
PDF is available here.
Abstract
We established a simple method for measuring and quantifying uptake dynamics of hyperpolarized (HP) (129)Xe in mouse brain, which includes application of a saturation recovery pulse sequence under controlled flow of HP (129)Xe. The technique allows pursuit of the time-dependent change in (129)Xe nuc...
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PMID: 19110512
PDF is available here.
PDF is available here.
Abstract
We have demonstrated the unique property of xenon to measure alveolar surface area noninvasively. In this article, we describe our human protocols and their safety, and our results for the measurement of the partial pressure of pulmonary oxygen (pO(2)) by observation of (129)Xe signal decay. We note...
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PMID: 17890035
PDF is available here.
PDF is available here.
Abstract
Abstract
We show that the proton signal enhancements due to (129)Xe-(1)H cross-relaxation (SPINOE) and overall shifts of the proton resonances due to the average dipolar shift created by the intense xenon magnetization are correlated. Protons behave as very useful sensors of the xenon magnetization. Indeed t...
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PMID: 17466548
PDF is available here.
PDF is available here.
Abstract
The noninvasive assessment of lung function using imaging is increasingly of interest for the study of lung diseases, including chronic obstructive pulmonary disease (COPD) and asthma. Hyperpolarized gas MRI (HP MRI) has demonstrated the ability to detect changes in ventilation, perfusion, and lung...
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PMID: 17410561
PDF is available here.
PDF is available here.
Abstract
Xenon porometry is a novel method used for characterizing porous materials by the (129)Xe nuclear magnetic resonance of xenon gas. With the method, the diffusion of gas is slowed down by immersing the material in a medium, which can be in liquid or solid state during measurements. Because of slow di...
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PMID: 17466763
PDF is available here.
PDF is available here.
Abstract
A series of experiments were performed to investigate why two peaks (D and E) of the five dissolved phase peaks in hyperpolarized (129)Xe rat head spectra appeared inconsistently in previous work. Specifically, spectra were acquired under conditions of various shim states, anaestheti...
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PMID: 17390344
PDF is available here.
PDF is available here.
Abstract
We have also attempted to measure the (129)Xe-(129)Xe dipole-dipole coupling constant between xenon atoms in the cavities of the xenon-Dianin's compound clathrate and have found that the dynamics of the xenon atoms (as investigated with molecular dynamics simulations) as well as (129)Xe multiple spi...
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PMID: 17311152
PDF is available here.
PDF is available here.
Abstract
In this proof of principle work, a technique is introduced to study hydrated surfaces using hyperpolarized (hp) 83Kr NMR spectroscopy. The longitudinal (T1) relaxation of hp-83Kr is shown to be extremely sensitive to the presence of adsorbed water on hydrophilic borosilicate and hydrophobic siliconi...
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PMID: 17243679
PDF is available here.
PDF is available here.
Surgical Neurology (67)1 2007
Abstract
Toxicologic Pathology (35)1 2007
Abstract
We summarize some of the technical and biologic problems and solutions associated with imaging the small animal lung and describe several important pulmonary disease applications. A major advantage of MR is direct imaging of the gas spaces of the lung using breathable gases such as helium and xenon....
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PMID: 17325972
PDF is available here.
PDF is available here.
Abstract
We exploit the solubility and chemical shift of (129)Xe, the magnetic resonance signal of which has been enhanced by 10(5) with hyperpolarization, to differentially image its transfer from the airspaces into the tissue barrier spaces and RBCs in the gas exchange regions of the lung. Based on a simpl...
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PMID: 17101964
PDF is available here.
PDF is available here.
Abstract
Two-dimensional (129)Xe exchange spectroscopy (EXSY) NMR measurements are presented for xenon atoms dissolved in a thermotropic nematic Liquid Crystal (LC), Merck Phase 4, confined to a mesoporous Controlled-Pore Glass (CPG) material with an average pore diameter of 81 A. Experiments were carried ou...
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PMID: 17066180
PDF is available here.
PDF is available here.
Abstract
Abstract
Abstract
We demonstrated spatial resolution of a specific target protein in vitro at micromolar concentration, with a readout scheme that reduces the required acquisition time by >3300-fold relative to direct detection. This technique uses the signal of free hyperpolarized xenon to dramatically amplify the s...
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PMID: 17053143
PDF is available here.
PDF is available here.
Abstract
We report the first enzyme-responsive (129)Xe NMR biosensor. This compound was synthesized in 13 steps by attaching the consensus peptide substrate for matrix metalloproteinase-7 (MMP-7), an enzyme that is upregulated in many cancers, to the xenon-binding organic cage, cryptophane-A. The final coupl...
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PMID: 17017809
PDF is available here.
PDF is available here.
Abstract
Magnetic resonance spectroscopy (MRS) was used to investigate the dynamics of hyperpolarized (HP) 129Xe respiration in the chests of mice under spontaneous respiration. The washout curve was analyzed using Kety's exchange model of inert gases, and the 3 factors that affect the slope of the washout c...
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PMID: 17139137
PDF is available here.
PDF is available here.
Abstract
We used the dual capability of hyperpolarized 129Xe for spectroscopy and imaging to develop new measures of xenon diffusing capacity in the rat lung that (analogously to the diffusing capacity of carbon monoxide or DLCO) are calculated as a product of total lung volume and gas transfer rate constant...
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PMID: 16767751
PDF is available here.
PDF is available here.
Abstract
Hyperpolarized (129)Xe (xenon) gas dissolved in a perfluorooctyl bromide (PFOB) emulsion stabilized with egg yolk phospholipid (EYP) is a possible contrast agent for quantitative blood flow measurements using magnetic resonance imaging. The NMR line shape of xenon dissolved in PFOB emulsion depends...
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PMID: 16942191
PDF is available here.
PDF is available here.
Abstract
Plant copper/quinone amine oxidases are homodimeric enzymes containing Cu(II) and a quinone derivative of a tyrosyl residue (2,4,5-trihydroxyphenylalanine, TPQ) as cofactors. These enzymes catalyze the oxidative deamination of primary amines by a classical ping-pong mechanism, i.e. two distinct half...
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PMID: 16519984
PDF is available here.
PDF is available here.
Abstract
This article briefly reviews the current literature and implementation of a typically non-firstline methodology to diagnose acute stroke: inhalational-mediated Xenon CT perfusion (Xe-CT). The intent of this article is to provide a short overview of this techniques; the reader is directed to the refe...
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PMID: 16808220
PDF is available here.
PDF is available here.
Physical Review Letters (96)5 2006
Abstract
We present a design for a spin-exchange optical pumping system to produce large quantities of highly polarized 129Xe. Low xenon concentrations in the flowing gas mixture allow the laser to maintain high Rb polarization. The large spin-exchange rate between Rb and 129Xe through the long-lived van der...
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PMID: 16486926
PDF is available here.
PDF is available here.
Abstract
The porosity in porous silicon was characterized using hyperpolarized (HP) xenon as a probe. HP xenon under conditions of continuous flow allows for the rapid acquisition of xenon NMR spectra that can be used to characterize a variety of materials. Two-dimensional exchange spectroscopy (EXSY) (129)X...
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PMID: 16257190
PDF is available here.
PDF is available here.
ChemBioChem (7)1 2006
Abstract
We use the prototypical biotinylated xenon biosensor to determine the relationship between the molecular composition of the xenon biosensor and the characteristics of protein-bound resonances. The effects of diastereomer overlap, dipole-dipole coupling, chemical-shift anisotropy, xenon exchange, and...
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PMID: 16342304
PDF is available here.
PDF is available here.
Applied Radiation and Isotopes (64)10-11 2006
Abstract
High-resolution dual X and gamma spectrometry has been optimized to improve the sensitivity in analyzing radioxenon from environmental samples, especially for the metastable isotopes (131Xem and 133Xem). The full-energy peak (FEP) efficiency curve in the 20-700 keV range has been established with a...
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PMID: 16603369
PDF is available here.
PDF is available here.
Abstract
We present a novel approach to perform high-sensitivity NMR imaging and spectroscopic analysis on microfluidic devices. The application of NMR, the most information-rich spectroscopic technique, to microfluidic devices remains a challenge because the inherently low sensitivity of NMR is aggravated b...
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PMID: 16351162
PDF is available here.
PDF is available here.
Abstract
We present the basic physical principles underlying noble gases'laser polarisation. Distinguishing characteristics of 129Xe NMR properties as well as theoretical basis for CBF measurement using laser polarised 129Xe are emphasized. Recent results are briefly presented and potential applications as w...
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PMID: 16424832
PDF is available here.
PDF is available here.
Abstract
We have used nuclear magnetic resonance (NMR) to obtain spatially and temporally resolved profiles of gas flow in microfluidic devices. Remote detection of the NMR signal both overcomes the sensitivity limitation of NMR and enables time-of-flight measurement in addition to spatially resolved imaging...
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PMID: 16214884
PDF is available here.
PDF is available here.
Abstract
Hyperpolarized (129)Xe can be used as a sensor to indirectly detect NMR spectra of heteronuclei that are neither covalently bound nor necessarily in direct contact with the Xe atoms, but coupled through long-range intermolecular dipole-dipole interactions. To reintroduce long-range dipolar couplings...
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PMID: 16005649
PDF is available here.
PDF is available here.
Abstract
An extensive study has been made on a series of multifunctional mesoporous silica materials, prepared by introducing two different organoalkoxysilanes, namely 3-[2-(2-aminoethylamino)ethylamino]propyltrimethoxysilane (AEPTMS) and 3-cyanopropyltriethoxysilane (CPTES) during the base-catalyzed condens...
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PMID: 16186913
PDF is available here.
PDF is available here.
Abstract
We present a method for accomplishing solution 129Xe biosensing based on flow (bubbling) of LE 129Xe gas through a solution in situ in the NMR probe, with pauses for data acquisition. This overcomes fundamental limitations of conventional solution-state LE 129Xe NMR, e.g., the difficulty in transfer...
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PMID: 15987104
PDF is available here.
PDF is available here.
Abstract
The classical model of coronary physiology implies the presence of maximal microcirculatory vasodilation during myocardial ischemia. However, Doppler monitoring of coronary blood flow (CBF) documented severe microcirculatory vasoconstriction during pacing-induced ischemia in patients with coronary a...
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PMID: 15840905
PDF is available here.
PDF is available here.
Abstract
In order to establish a continuous hyperpolarized xenon-129 (HP-129Xe) gas delivery system for MR imaging, the effect of the metallic materials in the gas pipeline on the signal intensity was investigated. In the gas pipeline, an appropriate surface is needed to minimize wall relaxation by the HP-12...
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PMID: 15919608
PDF is available here.
PDF is available here.
Protein Science (14)4 2005
Abstract
Protein Science (14)4 2005
Abstract
We show that the (129)Xe shift can sense more subtle changes: magnesium binding, BeF(3)(-) activation, and peptide binding by the Escherichia coli chemotaxis Y protein. (1)H-(15)N correlation spectroscopy and X-ray crystallography were used to identify two xenon-binding cavities in CheY that are pri...
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PMID: 15741343
PDF is available here.
PDF is available here.
Abstract
We compared spectra obtained from the heads of normal rats with spectra taken from the heads of rats that had undergone ligation of the external carotid (ECA) and pterygopalatine (PPA) arteries, the major feeding vessels of nonbrain tissue in the rat head. The amplitude of the peak at around 189 ppm...
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PMID: 15723409
PDF is available here.
PDF is available here.
Abstract
We present measurements of permeability, effective porosity and tortuosity on a variety of rock samples using NMR/MRI of thermal and laser-polarized gas. Permeability and effective porosity are measured simultaneously using MRI to monitor the inflow of laser-polarized xenon into the rock core. Tortu...
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PMID: 15833638
PDF is available here.
PDF is available here.
Abstract
We report initial NMR studies of gas dynamics in a particle bed fluidized by laser-polarized xenon (129Xe) gas. We have made preliminary measurements of two important characteristics: gas exchange between the bubble and emulsion phases and the gas velocity distribution in the bed. We used T2* contra...
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PMID: 15833613
PDF is available here.
PDF is available here.
Abstract
129Xe NMR spectra of xenon dissolved in acetonitrile confined into three mesoporous silica gels with nominal pore diameters of 40, 60, and 100 A have been measured over the temperature range 170-245 K. The spectra consist of a number of lines, which contain detailed information on the system. The mo...
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PMID: 16866438
PDF is available here.
PDF is available here.
Abstract
We present a two-pulse protocol for estimating the decay time without the need for flip-angle estimation and demonstrate it in the rat brain. METHOD: After rat inhalation of hyperpolarized Xe, two MR spectra of the rat head were obtained at various delay times (4-16 s) and the logarithmic ratio of t...
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PMID: 16127250
PDF is available here.
PDF is available here.
Abstract
We present a detailed NMR characterization of the binding of a biotin-derivatized caged-xenon sensor to avidin. Binding of "functionalized" xenon to avidin leads to a change in the chemical shift of the encapsulated xenon in addition to a broadening of the resonance, both of which serve as NMR marke...
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PMID: 15548026
PDF is available here.
PDF is available here.
Abstract
We concentrate on the properties and applications of hyperpolarized xenon. This review discusses the physics of producing hyperpolarization, the NMR-relevant properties of 129Xe, specific MRI methods for hyperpolarized gases, applications of xenon to biology and medicine, polarization transfer to ot...
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PMID: 15566166
PDF is available here.
PDF is available here.
Abstract
We have found evidence, in the form of fissiogenic xenon isotopes, for in situ decay of 244Pu in individual 4.1- to 4.2-billion-year-old zircons from the Jack Hills region of Western Australia. Because of its short half-life, 82 million years, 244Pu was extinct within 600 million years of Earth's fo...
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PMID: 15459384
PDF is available here.
PDF is available here.