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PubMed2000

High resolution feshbach spectroscopy of cesium

We measure high-resolution Feshbach resonance spectra for ultracold cesium atoms colliding in different hyperfine and magnetic sublevels. More than 25 resonances are observed for magnetic fields up to 230 G and their positions are measured with an accuracy down to 0.03 G. From these spectra several ground-state molecular interaction parameters can be extracted with sufficient accuracy to permit for the first time an unambiguous and accurate determination of cesium's ultracold collision properties [P. J. Leo, C. J. Williams, and P. S. Julienne, following Letter, Phys. Rev. Lett. 85, 2721 (2000)].

Journal Article↗
PubMed2001

Implementation of the beam reversal technique on compact cesium clocks: towards an improvement in accuracy.

We report the evaluation of the residual phase difference deltaphi in a short (18 cm) Ramsey cavity by implementing the beam reversal technique to an optically pumped cesium beam clock. Deltaphi is measured to be 21 +/- 1.5 microrad, allowing a more accurate evaluation of the frequency performances of this small cesium clock. Finally, the clock accuracy is equal to 1.1 x 10(-13).

Journal Article↗
PubMed1966

Biophysical studies of respiratory syncytial virus. I. Density of respiratory syncytial virus and associated complement-fixing antigens in cesium chloride density gradient.

Coates, Helen V. (National Institute of Allergy and Infectious Diseases, Bethesda, Md.), Ben R. Forsyth, and R. M. Chanock. Biophysical studies of respiratory syncytial virus. I. Density of respiratory syncytial virus and associated complement-fixing antigens in a cesium chloride density gradient. J. Bacteriol. 91:1263-1269. 1966.-Concentrated fluids from respiratory syncytial (RS) virus-infected tissue cultures (HEp-2 and BEK) were subjected to equilibrium sedimentation in cesium chloride. When two antigenically distinct strains of RS virus (Long and 18537) were tested, approximately 90% of the infectious virus was recovered in a sharp, symmetrical peak with a density of 1.22 to 1.24. In a similar study, unconcentrated virus had a density of 1.25 to 1.27. Two immunologically distinguishable complement-fixing antigens (antigens A and B) were detected at densities of 1.28 to 1.32 and 1.23 to 1.37. In addition, the existence of a third antigen (density of 1.22 to 1.30) was suggested. The possible origin of these antigens is discussed relative to the known properties of RS virus and the other myxoviruses.

Antigens↗
PubMed1960

Occurrence of scandium-46 and cesium-134 in radioactive fallout.

Two hitherto unreported induced radionuclides, scandium-46 and cesium-134, have been detected in fallout material. Identification was made by chemical separation and gamma scintillation spectrometry. While the origin of these materials is not known, possible routes of formation from stable elements are suggested.

Cesium↗
PubMed1961

Strontium-90 and cesium-137 in North American milk.

The strontium-90 and cesium-137 concentrations in powdered milk in North America vary roughly with the specific activity of rain. The Sr(90)/Cs(137). ratios in over 800 powdered milk samples taken from 60 stations in North America from 1957-60 have a standard deviation of only 44 percent.

Animals↗
PubMed1997

Nature of mutation in the human hprt gene following in vivo exposure to ionizing radiation of cesium-137.

The current study comprises the analysis of mutations in 10 individuals accidentally exposed to cesium-137 during the 1987 radiological accident in Goiânia, Brazil. Their exposures were among the highest experienced, ranging from 1 to 7 Gy. Peripheral T-lymphocyte samples were obtained 3.3 years after the original exposure and mutation was studied at the hprt locus using the 6-thioguanine-resistance selection assay. The mutational spectrum for the exposed population is comprised of 90 independent mutants. Based on T-cell receptor analysis, only 5% (5/95) were clonally related. Mutants were initially studied using RT-PCR and directly sequenced using an automated laser fluorescent DNA sequencer. Mutants that repeatedly failed to produce cDNAs were studied using a multiplex PCR assay with genomic DNA. Missense mutations were the most frequent event recovered, comprising 40% (23/57) of the spectral sample. An excess of events involving A:T base pairs was observed, exhibiting a significant difference (chi 2 = 12.7, P = 0.0004) when compared to the spontaneous spectrum. This finding may reflect the effect of ionizing radiation-induced damage, suggesting a potential similarity to radiation effects in prokaryotes. At the genomic level, 36.7% (33/90) of the mutants exhibited gross structural alterations, as detected by multiplex PCR. Deletion events were over-represented in our spectral sample, displaying a twofold increase when compared to the frequency observed in the spontaneous mutation database.

Adolescent↗
PubMed2001

7Li-NMR and FTIR studies of lithium, potassium, rubidium, and cesium complexes with ionophore lasalocid in solution.

Lasalocid metal salts were combined with 1 : 1 lithium and 2:2 potassium, rubidium, and cesium to form complexes. The nature of the lasolocid salt complexes was studied in a solid and chloroform by FTIR spectroscopy in the middle and far IR regions. The process of the complexation of lithium was also studied by (7)Li-NMR. In chloroform a 1 : 1 complex of lasalocid and Li(+) ions was formed. Continuous absorption was observed in the far FTIR spectrum of this complex. It indicated large Li(+) polarizability, which was due to fast fluctuations of the Li(+) ions in the multiminima potentials, in the monomeric structure. In the lasalocid salt with the other monovalent cations (K(+), Rb(+), Cs(+)) 2:2 complexes were formed in which the cations showed cation polarizability, which strongly depended on the mass and the radius of the cations.

Cesium↗
PubMed1978

Structural determination of 'cord factor' from a Corynebacterium diphtheriae strain by a combination of mass spectral ionization methods: field desorption cesium cationization and electron impact mass spectrometry studies.

The composition and structure of a preparation of 'cord factor' (di-beta-hydroxy acyl trehaloses) from Corynebacterium diphtheriae have been determined by a combination mass spectral ionization methods. The methods were tested by means of synthetic 6,6'-dicorynomycolate of alpha-D-trehalose prior to their use on natural products. The determination of the molecular weight of the components and the estimation of their relative abundance in the natural mixture were made by field desorption mass spectrometry and cationization by means of cesium iodide. At least 22 molecular species differing from the chain length and the unsaturation degree were detected (carbon numbers C76 to C66). The position of acylation and the nature of the acyl chains were obtained from the electron impact mass spectra of the trimethylsilyl derivatives. The trehalose molecular was found to be esterified by a complex mixture of corynomycolic acids (3-hydroxy 2-alkyl fatty acids) which were present as saturated, mono-unsaturated and di-unsaturated homologues (carbon numbers C32 to C24). The 6 and 6' sites of acylation were the only detectable ones.

Cations↗
PubMed1988

Cesium ion liquid secondary ion mass spectrometry of membrane-bound glycoproteins: structural and topological considerations of acetylcholine receptor from Torpedo californica.

We report mass mapping of a large (270 kD) multisubunit membrane bound glycoprotein, nicotinic acetylcholine receptor from Torpedo californica, using enzymic digests of the affinity purified whole receptor and cesium ion liquid secondary ion mass spectrometry. Peptides, glycopeptides and derivatized N-linked oligosaccharides were isolated by HPLC and identified by LSIMS. We have shown that mass spectrometric sensitivity is improved a hundred-fold through use of computer-controlled mass window stepping of an electro-optical multichannel array detection system on a LSIMS double focusing mass spectrometer. This new method permitted determination of the complete fragmentation pattern of Man8N2-ABEE using only 5 picomoles of sample.

Amino Acid Sequence↗
PubMed2005

How trimethyl(trifluoromethyl)silane reacts with itself in the presence of naked fluoride--a one-pot synthesis of bis([15]crown-5)cesium 1,1,1,3,5,5,5-heptafluoro-2,4-bis(trifluoromethyl)pentenide.

Reactions of trimethyl(trifluoromethyl)silane in the presence of "naked" fluoride proceed up to a temperature of +5 degrees C mainly with formation of [Me3Si(CF3)2]-. A further rise of temperature up to about 20 degrees C gives evidence for the formation of a salt with the 1,1,1,2,3,6,6,6-octafluoro-2,4,4,5,5-pentakis(trifluoromethyl)hexan-3-ide anion. This intermediate decomposes at room temperature into the 1,1,1,3,5,5,5-heptafluoro-2,4-bis(trifluoromethyl)pentenide anion. The bis([15]crown-5)cesium salt, [Cs([15]crown-5)2][(CF3)2CCFC(CF3)2] has been characterized unambiguously as the stable final product of this reaction sequence. Thermal decomposition of this salt opens a convenient nontoxic route to obtain 1,1,3,3-tetrakis(trifluoromethyl)allene, (F3C)2C=C=C(CF3)2.

Cesium↗
PubMed1991

Cytogenetic damage induced in vivo to mice by single exposure to cesium chloride.

Female laboratory bred albino mice (2n = 40) were orally administered cesium chloride (CsCl) in aqueous solution as a single dose and the damage induced at the chromosomal level was observed in bone marrow cells after 6, 12, 18, and 24 hours of exposure. The concentrations of the chemical given were calculated as fractions of the LD50, namely 1/5, 1/10, and 1/20. The cytogenetic endpoints screened for were chromosomal aberrations (CA) and divisional frequency or mitotic index (MI). The frequency of chromosomal aberrations induced was directly proportional to the concentration of the chemical administered. The highest dose was the most toxic and was considered to be the maximum tolerance level. Effects on divisional frequency were variable, the highest concentration being significantly mitostatic, the middle one ineffective, and the lowest slightly mitogenic. In general, the observations indicate that CsCl is clastogenic when administered orally to mice in vivo and the effects are dose-dependent.

Analysis of Variance↗
PubMed2005

Uncertainty of inductively coupled plasma mass spectrometry based measurements: an application to the analysis of urinary barium, cesium, antimony and tungsten.

The wide use of barium (Ba), cesium (Cs), antimony (Sb) and tungsten (W) in many industrial and agricultural fields causes the increased release of these metals into the environment, laying the basis for health risk. To assess the exposure for the general population, the development of adequate and reliable analytical techniques becomes compulsory. This study refers to the quantification of urinary Ba, Cs, Sb and W levels by both quadrupole (Q) and sector field (SF) inductively coupled plasma mass spectrometry (ICP-MS). The two procedures were compared for their performances and their measurement uncertainties. The limits of detection were (Q and SF) 23.0 and 5.21 ng L(-1) for Ba; 21.1 and 7.52 ng L(-1) for Cs; 1.09 and 0.43 ng L(-1) for Sb; and 0.36 and 0.49 ng L(-1) for W. The trueness was better than 93.3% and the precision less than 12% for both techniques. Relative expanded uncertainties of the analytical procedures, at the median levels found in the general population, were below 5% for all the elements with both ICP-MS techniques. The uncertainties related to the calibration and repeatability were the parameters most influencing the final analytical performance. The urinary median values observed in healthy subjects from central Italy were 1146, 4301, 60.8 and 48.5 ng L(-1) for Ba, Cs, Sb and W, respectively.

Adult↗
PubMed1999

Nuclear magnetic resonance and oxygen affinity study of cesium binding in human erythrocytes.

We investigated the interaction of the cesium ion (Cs(+)) with the anionic intracellular components of human red blood cells (RBCs); the components studied included 2,3-bisphosphoglycerate (BPG), ADP, ATP, inorganic phosphate (P(i)), carbonmonoxy hemoglobin (COHb), and RBC membranes. We used spin-lattice (T(1)) and spin-spin (T(2)) (133)Cs NMR relaxation measurements to probe Cs(+) binding, and we found that Cs(+) bound more strongly to binding sites in BPG and in RBC membranes than in any other intracellular component in RBCs at physiologic concentrations. By using James-Noggle plots, we obtained Cs(+) binding constants per binding site in BPG (66 +/- 8 M(-1)), ADP (19 +/- 1 M(-1)), ATP (25 +/- 3 M(-1)), and RBC membranes (55 +/- 2 M(-1)) from the observed T(1) values. We also studied the effect of Cs(+) on the oxygen (O(2)) affinity of purified Hb and of Hb in intact RBCs in the absence and in the presence of BPG. In the absence of BPG, the O(2) affinity of Hb decreased upon addition of Cs(+). However, in the presence of BPG, the O(2) affinity of Hb increased upon addition of Cs(+). The O(2) affinity of Cs(+)-loaded human RBCs was larger than that of Cs(+)-free cells at the same BPG level. (31)P NMR studies on the pH dependence of the interaction between BPG and Hb indicated that the presence of Cs(+) resulted in a smaller fraction of BPG available to bind to the cleft of deoxyHb. Our NMR and O(2) affinity data indicate that a strong binding site for Cs(+) in human RBCs is BPG. A partial mechanism for Cs(+) toxicity might arise from competition between Cs(+) and deoxyHb for BPG, thereby increasing oxygenation of Hb in RBCs, and thus decreasing the ability of RBCs to give up oxygen in tissues. The presence of Cs(+) at 12.5 mM in intact human RBCs containing BPG at normal concentrations did not, however, alter significantly the O(2) affinity of Hb, thus ruling out the possibility of Cs(+)-BPG interactions accounting for Cs(+) toxicity in this cell type.

2,3-Diphosphoglycerate↗
PubMed1998

Sustained left ansae subclaviae stimulation for a 5-hour period inhibits cesium-induced ventricular arrhythmogenesis in rabbits.

The acute stimulation of the left ansae subclaviae (LAS) augments cesium chloride (Cs)- induced early afterdepolarizations (EADs) and ventricular arrhythmias. However, the effect of sustained cardiac sympathetic nerve stimulation on Cs-induced arrhythmogenesis remains to be elucidated. Three protocols were used. In protocol A, seven rabbits received continuous LAS stimulation for 5 h (study group), and were then given bolus injections of Cs at 5-min intervals (initial dose 1.5 mmol/kg, followed by repetitive doses 1 mmol/kg). Another eight rabbits received the same dose of Cs after a 5-h observation period without LAS stimulation (control group). The effects of 2 h of LAS stimulation were also assessed in five rabbits of each group. In protocol B, a bolus injection of Cs (1 mmol/kg) was administered during atrial pacing (cycle length: 250 ms) after a 5-h period with (study group, n = 5) or without (control group, n = 5) LAS stimulation, and the amplitude of Cs-induced EADs was measured. In protocol C, a bolus injection of isoproterenol (0.05 mg/kg) was given after a 5-h period with (study group, n = 5) or without (control group, n = 5) LAS stimulation to assess the sensitivity to beta-adrenergic stimulation. In protocol A, the cumulative doses of Cs required for the induction of ventricular tachycardia (VT) and fibrillation (VF) were significantly greater in the study group than in the control group (4.4 +/- 0.1 v 2.8 +/- 0.3 mmol/kg for VT, P<0.05; 5.8 +/- 0.3 v 4.1 +/- 0.4 mmol/kg for VF, P<0.05). However, 2 h of LAS stimulation did not influence the cumulative doses of Cs required for the induction of VT and VF. In protocol B, the amplitude of Cs-induced EADs was significantly lower in the study group than in the control group. In protocol C, the increase in rate-pressure product by isoproterenol was significantly less in study than in control groups (3492 +/- 612 v 6504 +/- 829, P<0.05). These results suggest that sustained LAS stimulation exerts a protective effect against Cs-induced arrhythmogenesis in the rabbit heart, which may be partially explained by desensitization to the beta-adrenergic stimulation.

Action Potentials↗
PubMed1984

Central depressant action of cesium in mice.

Cesium chloride (CsCl) at several dose levels (1.25-20.0 mEq/kg IP) was administered acutely to albino mice whose behavior was compared with that in corresponding saline controls. Motor activity decreased and Straub tail occurred in a dose-related manner. Signs of autonomic disturbance, diarrhea, and salivation were seen with toxic doses. Subchronic administration of CsCl (5.0 mEq/kg/day IP for 7 days) exerted a phenothiazine-like effect in mice, reducing amphetamine-induced aggregation toxicity and enhancing pentobarbital-induced hypnosis. The antinociceptive action of morphine was unaltered by identical multiple administrations of CsCl. These results indicate a specific neurosuppressant action of CsCl on mouse CNS and suggest exploration of this alkali earth metal for antipsychotic-like activity.

Amphetamine↗
PubMed1988

Comparison of the in vitro translation capacity of Taenia crassiceps metacestode mRNA prepared by the phenol and cesium chloride method.

Total RNA of T. crassiceps metacestodes harvested from male and female NMRI mice was prepared by both the phenol extraction technique and cesium chloride (CsCl) gradient centrifugation. mRNA was selected by oligo (dT)-cellulose affinity chromatography and used as the template for the in vitro translation of parasite polypeptides in a cell-free rabbit reticulocyte lysate. The template activity of the mRNA obtained after CsCl preparation was clearly higher, as shown by the amount of 35S-methionine incorporated into the translation products and by fluorographed SDS-PAGE of the synthesized labelled polypeptides. SDS-PAGE fluorographs of antigens encoded by the mRNA prepared by CsCl centrifugation and selected by immunoprecipitation using purified IgG antibodies of T. crassiceps-infected mice (day 80 postinfection) exhibited seven labelled polypeptides of about 65, 46, 45, 42, 34, 29 kDa and a predominant 20-kDa antigen. The latter polypeptide was the only one recognized by the antibodies amongst the in vitro translation products directed by mRNA prepared by the phenol method.

Animals↗
PubMed1975

Cesium induced rectifications in frog myelinated fibres.

Voltage clamp experiments done on nodes of Ranvier show that external application of Cesium blocks the inward but not the outward potassium currents. Internal application of Cs ions reduces the outward K-current and the inward K-current is not affected. These results support the hypotheses that K ions cross th- K-channel after dehydration at superficial sites where competition may occur with Cs-ions.

Animals↗
PubMed1978

Preparative density gradient centrifugation of RNA and DNA in cesium sulfate-urea mixture.

A new procedure is described for a large scale separation and purification of unfixed DNA and RNA from a mixture of partially extracted nucleic acids and lysates of subcellular fractions by centrifugation to equilibrium in cesium sulfate-urea mixture. Optimum conditions are described for the separation and quantative recovery of both RNA and DNA in a pure form. The procedure allows determination of peak buoyant densities of 4-5s RNA, 7-11s mRNA and total cytoplasmic RNA. The procedure also allows fractionation of small molecular weight classes of cytoplasmic RNAs from the 18s and 28s rRNAs.

Animals↗