Positronium Formation in Muscle

Gustafson, D.R.

doi:10.1016/s0006-3495(70)86304-4

Cited by 10 publications

(7 citation statements)

References 2 publications

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“…Among the most important conclusions from the earlier research 11 – 22 , it is worth pointing out that sample preparation and measurement conditions are of key importance for the PALS response (e.g. time, drying, storage in formalin—significantly modifies the results).…”

Section: Resultsmentioning

confidence: 95%

“…Positron annihilation lifetime spectroscopy (PALS) in application to the living biological systems was discussed in a very limited number of papers, focusing mainly on readily available samples. Among others, the animal and human tissues and cells were investigated: rat muscles and brain 11 , mouse skin 12 , human tissues (skin and hair) 13 – 16 , human cell culture 17 . The analysis of the impact of humidity was carried out on simple organisms—yeast 18 .…”

Section: Introductionmentioning

confidence: 99%

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Studies on healthy and neoplastic tissues using positron annihilation lifetime spectroscopy and focused histopathological imaging

Zgardzińska

Chołubek

Jarosz

et al. 2020

Sci Rep

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Samples of healthy and neoplastic myometrial tissues were investigated using Positron Annihilation Lifetime Spectroscopy (PALS). Meaningful differences between normal and diseased tissues were observed for each patient. The differences were also clearly visible for various kinds of lesions in each patient. The set of lifetimes and intensities obtained from PALS was correlated with the histopathological examinations of the same fragments of tissues. Strong coincidence between PALS parameters and histopathological findings was observed only in the case of a very precise correlation of the investigated area in both techniques. Measurements and discussion presented here were carried out to develop a method for measuring the sub-nanometric structure of human tissues. This kind of investigation, using positron probe, creates an opportunity of a new application in Positron Emission Tomography (PET).

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Section: Resultsmentioning

confidence: 95%

Section: Introductionmentioning

confidence: 99%

Studies on healthy and neoplastic tissues using positron annihilation lifetime spectroscopy and focused histopathological imaging

Zgardzińska

Chołubek

Jarosz

et al. 2020

Sci Rep

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“…19,20,22,57,85,86 The destructive effect of positrons on membranes is negligible and the degree of perturbation caused by the positron probe minimal, with the typical concentration of positron probes required, 10 À16 M, being several orders of magnitude less than conventional chemical probes. 19,20,22,57,85,86 The destructive effect of positrons on membranes is negligible and the degree of perturbation caused by the positron probe minimal, with the typical concentration of positron probes required, 10 À16 M, being several orders of magnitude less than conventional chemical probes.…”

Section: Application Of Pals To Biologically Relevant Systemsmentioning

confidence: 99%

“…Positron probes have been applied to complex biological systems including tissue, muscle, human erythrocytes and proteins since the 1960's. 19,20,22,57,85,86 The destructive effect of positrons on membranes is negligible and the degree of perturbation caused by the positron probe minimal, with the typical concentration of positron probes required, 10 À16 M, being several orders of magnitude less than conventional chemical probes. An interesting recent study by Axpe et al 57 has utilised PALS to determine differences in the free volume void size of living cultures of healthy skin cells compared to colorectal cancer cells from the same patient.…”

Section: Application Of Pals To Biologically Relevant Systemsmentioning

confidence: 99%

Positron annihilation lifetime spectroscopy (PALS): a probe for molecular organisation in self-assembled biomimetic systems

Fong

Dong

Hill

et al. 2015

Phys. Chem. Chem. Phys.

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Positron annihilation lifetime spectroscopy (PALS) has been shown to be highly sensitive to conformational, structural and microenvironmental transformations arising from subtle geometric changes in molecular geometry in self-assembling biomimetic systems. The ortho-positronium (oPs) may be considered an active probe that can provide information on intrinsic packing and mobility within low molecular weight solids, viscous liquids, and soft matter systems. In this perspective we provide a critical overview of the literature in this field, including the evolution of analysis software and experimental protocols with commentary upon the practical utility of PALS. In particular, we discuss how PALS can provide unique insight into the macroscopic transport properties of several porous biomembrane-like nanostructures and suggest how this insight may provide information on the release of drugs from these matrices to aid in developing therapeutic interventions. We discuss the potentially exciting and fruitful application of this technique to membrane dynamics, diffusion and permeability. We propose that PALS can provide novel molecular level information that is complementary to conventional characterisation techniques.

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“…The fivecoordinate halogenobis(diethyldithiocarbamato) iron (III) complexes, which are paramagnetic and hardly reducible, were also tested for the effect on the o-Ps quenching. Unlike the six-coordinate iron(III) dithiocarbamates, they only slightly affected the o-Ps lifetime, indicating that the spin-conversion process of o-Ps quenching is much less important than the oxidation process.Positronium, which is the bound state of a positron with an electron, has attracted increasing attention from many researchers and the positron annihilation as a nuclear probe has been widely applied to the study of the chemical [ 1 -6 ], miceller [ 7 -9 ], and biological systems [10][11][12]. The variation of the intensity of the long-lived component of positronium against the inhibitor concentration in systems of organic solutions has recently been successfully explained in terms of the spur model [13][14][15].…”

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confidence: 99%

Ortho-positronium Quenching in Benzene Solutions of Iron(III) Dithiocarbamates

et al. 1980

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Lifetimes of the long-lived component of positronium, orthopositronium (o-Ps) were measured in benzene solutions of sixcoordinate iron(III) dithiocarbamates. The lifetime decreased with increasing solute concentration. The lifetime was strongly affected by the substituent group attached to the nitrogen atom in the ligand, and was related to the redox potential of the compound; highly reducible tris(pyrrolidinyl-N-carbodithioato) iron(III), Fe(Pyrrdtc) 3 , gave the greatest rate constant, 14.9X 10' M" 1 s" 1 , whereas the least reducible of the compounds examined, tris(N, N-dicyclohexyldithiocarbamato) iron (III), Fe(c-Hx 2 dtc) 3 , gave the smallest, 4.5 X 10' M" 1 s~l. The fivecoordinate halogenobis(diethyldithiocarbamato) iron (III) complexes, which are paramagnetic and hardly reducible, were also tested for the effect on the o-Ps quenching. Unlike the six-coordinate iron(III) dithiocarbamates, they only slightly affected the o-Ps lifetime, indicating that the spin-conversion process of o-Ps quenching is much less important than the oxidation process.Positronium, which is the bound state of a positron with an electron, has attracted increasing attention from many researchers and the positron annihilation as a nuclear probe has been widely applied to the study of the chemical [ 1 -6 ], miceller [ 7 -9 ], and biological systems [10][11][12]. The variation of the intensity of the long-lived component of positronium against the inhibitor concentration in systems of organic solutions has recently been successfully explained in terms of the spur model [13][14][15]. On the other hand, the changes of the lifetime by inorganic salts have been investigated mainly in aqueous solutions and several attempts have been made to estimate the redox potential of e + /Ps couple [2,6]. In aqueous solutions, the rate constants for the reaction of o-Ps with inorganic salts have been reported to vary over a wide range; i. e., (18.0-29.0) X 10' M' 1 s" 1 for KMnO, [4,16], and nearly zero for NaCl, ZnCl 2 , KCl, etc. [17].Although the reactions of o-Ps have been comparatively well examined for simple inorganic salts, few systematic studies have been conducted on the reactions with coordination compounds. Previously, we have examined the reactions of o-Ps with various kinds of (3-diketonates in benzene, and found that the acceleration of o-Ps decay is mainly attributable to the oxidation of o-Ps by the compounds [18][19][20][21]. As an extension of our previous work, we investigated the reactions of o-Ps with a series of substituted dithiocarbamatoiron(III) complexes in benzene. As the values of the ligand field splitting parameter, Δ, of the dithiocarbamatoiron(III) complexes are close to the spin-pairing energy, the complexes show spin crossover properties, depending on the kind of the substituents in the legating dithiocarbamate. The equilibrium between the high-spin and low-spin states ( 6 A, ^ J T 2 ) may be affected by the inductive, mesomeric, and steric effects of the substituents attached to the nitrogen atom [22][23][24]. At a ...

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Positronium Formation in Muscle

Cited by 10 publications

References 2 publications

Studies on healthy and neoplastic tissues using positron annihilation lifetime spectroscopy and focused histopathological imaging

Studies on healthy and neoplastic tissues using positron annihilation lifetime spectroscopy and focused histopathological imaging

Positron annihilation lifetime spectroscopy (PALS): a probe for molecular organisation in self-assembled biomimetic systems

Ortho-positronium Quenching in Benzene Solutions of Iron(III) Dithiocarbamates

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