Porous glasses as a host of luminescent materials, their applications and site selective determination

Reisfeld, R.; Jasińska, B.; Левченко, В. И.; Gorgol, M.; Saraidarov, Tsiala; Popov, Inna; Антропова, Т. В.; Rysiakiewicz-Pasek, E.

doi:10.1016/j.jlumin.2015.02.022

Cited by 14 publications

(7 citation statements)

References 31 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…At room temperature, the  5 reached 122.7(5) ns. This slight increase in comparison to the base material was discussed more broadly in [11]. A shape of temperature dependence of the longest-lived component lifetime was similar for both samples: the undoped material and the one incorporated with dye molecules.…”

Section: Resultsmentioning

confidence: 56%

See 1 more Smart Citation

PALS investigations of matrix Vycor glass doped with molecules of luminescent dye and silver nanoparticles. Discrepancies from the ETE model

2015

Self Cite

View full text Add to dashboard Cite

Abstract.A thermal stability of three materials: undoped reference Vycor glass, glass fi lled with ROT-305 red dye, and silver nanoparticles was investigated by positron annihilation lifetime spectroscopy (PALS) in a broad temperature range (from 93 to 473 K). The attempt of pore size calculations from the ortho-positronium lifetime data was performed using the extended Tao-Eldrup (ETE) model. Below room temperature, a signifi cant decrease in lifetime values of the longest-lived component was found for all the samples. This effect could not be explained by thermal shrinkage of the material and is probably caused by interaction of o-Ps with a Vycor glass matrix. The greatest discrepancy from the ETE model predictions was observed for the reference glass. Doping the base material with dye molecules and silver nanoparticles resulted in similar small decrease in this discrepancy. After reheating the samples to the room temperature, the PALS components returned to the initial values. In the temperature range of 293-473 K, quite good agreement between PALS results and the ETE model predictions was observed for the reference glass and the glass incorporated with dye molecules. The observed small discrepancy in this range could possibly be partly explained by thermal expansion of the material. For the glass doped with silver nanoparticles, a signifi cant change in PALS parameters was observed in the temperature range from 403 to 473 K.

show abstract

Section: Resultsmentioning

confidence: 56%

“…[10]. In the reference material, the average pore sizes presented a wide distribution from 15 to 25 nm [11], as determined by liquid nitrogen (LN) sorption and small-angle X-ray scattering (SAXS). Basic parameters for the reference glass obtained by SAXS are presented in Table 1.…”

Section: Materials and Experimentalmentioning

confidence: 99%

PALS investigations of matrix Vycor glass doped with molecules of luminescent dye and silver nanoparticles. Discrepancies from the ETE model

2015

Self Cite

View full text Add to dashboard Cite

show abstract

“…The positron annihilation lifetime spectroscopy (PALS) is a well-established method in the material science [10][11][12]. However, in order to make use of the positronium properties in the in vivo medical diagnostics, development of the system combining PET and PALS is required [1,7].…”

Section: Introductionmentioning

confidence: 99%

Performance assessment of the 2 γpositronium imaging with the total-body PET scanners

et al. 2020

View full text Add to dashboard Cite

Purpose In living organisms, the positron-electron annihilation (occurring during the PET imaging) proceeds in about 30% via creation of a metastable ortho-positronium atom. In the tissue, due to the pick-off and conversion processes, over 98% of ortho-positronia annihilate into two 511 keV photons. In this article, we assess the feasibility for reconstruction of the mean ortho-positronium lifetime image based on annihilations into two photons. The main objectives of this work include the (i) estimation of the sensitivity of the total-body PET scanners for the ortho-positronium mean lifetime imaging using 2γ annihilations and (ii) estimation of the spatial and time resolution of the ortho-positronium image as a function of the coincidence resolving time (CRT) of the scanner. Methods Simulations are conducted assuming that radiopharmaceutical is labeled with 44Sc isotope emitting one positron and one prompt gamma. The image is reconstructed on the basis of triple coincidence events. The ortho-positronium lifetime spectrum is determined for each voxel of the image. Calculations were performed for cases of total-body detectors build of (i) LYSO scintillators as used in the EXPLORER PET and (ii) plastic scintillators as anticipated for the cost-effective total-body J-PET scanner. To assess the spatial and time resolution, the four cases were considered assuming that CRT is equal to 500 ps, 140 ps, 50 ps, and 10 ps. Results The estimated total-body PET sensitivity for the registration and selection of image forming triple coincidences (2γ+γprompt) is larger by a factor of 13.5 (for LYSO PET) and by factor of 5.2 (for plastic PET) with respect to the sensitivity for the standard 2γ imaging by LYSO PET scanners with AFOV = 20 cm. The spatial resolution of the ortho-positronium image is comparable with the resolution achievable when using TOF-FBP algorithms already for CRT = 50 ps. For the 20-min scan, the resolution better than 20 ps is expected for the mean ortho-positronium lifetime image determination. Conclusions Ortho-positronium mean lifetime imaging based on the annihilations into two photons and prompt gamma is shown to be feasible with the advent of the high sensitivity total-body PET systems and time resolution of the order of tens of picoseconds.

show abstract

“…In Figure 1, an example of the hemoglobin molecule and the main mechanisms for the positronium annihilations inside the cells is presented. The positron annihilation lifetime spectroscopy (PALS) is a well established method in the material science [8][9][10] . However, in order to make use of the positronium properties in the in-vivo medical diagnostics development of the system combining PET and PALS is required 1,3 .…”

Section: Introductionmentioning

confidence: 99%

Performance assessment of the 2$γ$ positronium imaging with the total-body PET scanners

Moskal,

Kisielewska,

Bura

et al. 2019

Preprint

View full text Add to dashboard Cite

In living organisms the positron-electron annihilation (occurring during the PET imaging) proceeds in about 30% via creation of a metastable ortho-positronium atom. In the tissue, due to the pick-off and conversion processes, over 98% of ortho-positronia annihilate into two 511 keV photons. In this article we assess the feasibility for reconstruction of the mean ortho-positronium lifetime image based on annihilations into two photons. The main objectives of this work include: (i) estimation of the sensitivity of the total-body PET scanners for the ortho-positronium mean lifetime imaging using 2γ annihilations, and (ii) estimation of the spatial and time resolution of the ortho-positronium image as a function of the coincidence resolving time (CRT) of the scanner.Methods: Simulations are conducted assuming that radiopharmaceutical is labelled with 44 Sc isotope emitting one positron and one prompt gamma. The image is reconstructed on the basis of triple coincidence events. The ortho-positronium lifetime spectrum is determined for each voxel of the image. Calculations were performed for cases of total-body detectors build of (i) LYSO scintillators as used in the EXPLORER PET, and (ii) plastic scintillators as anticipated for the cost-effective total-body J-PET scanner. To assess the spatial and time resolution the three cases were considered assuming that CRT is equal to 140 ps, 50 ps and 10 ps. Results:The estimated total-body PET sensitivity for the registration and selection of image forming triple coincidences (2γ + γ prompt ) is larger by a factor of 12.2 (for LYSO PET) and by factor of 4.7 (for plastic PET) with respect to the sensitivity for the standard 2γ imaging by LYSO PET scanners with AFOV = 20 cm. The spatial resolution of the ortho-positronium image is comparable with the resolution achievable when using TOF-FBP algorithms already for CRT = 50 ps. For the 20 min scan the resolution better than 20 ps is expected for the mean ortho-positronium lifetime image determination.Conclusions: Ortho-positronium mean lifetime imaging based on the annihilations into two photons and prompt gamma is shown to be feasible with the advent of the high sensitivity total-body PET systems and time resolution of the order of tens of picoseconds.

show abstract

Porous glasses as a host of luminescent materials, their applications and site selective determination

Cited by 14 publications

References 31 publications

PALS investigations of matrix Vycor glass doped with molecules of luminescent dye and silver nanoparticles. Discrepancies from the ETE model

PALS investigations of matrix Vycor glass doped with molecules of luminescent dye and silver nanoparticles. Discrepancies from the ETE model

Performance assessment of the 2 γpositronium imaging with the total-body PET scanners

Performance assessment of the 2$γ$ positronium imaging with the total-body PET scanners

Contact Info

Product

Resources

About