Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.4.25.1 (proteasome)
 28,817 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Lithium fluoride thermoluminescence (TL) detectors, with different Li composition (Li-6 and Li-7) and various activators (LiF:Mg,Ti, LiF:Mg,Cu,P), are widely used for dosimetry in space. The primary radiation field in space is composed of fast electrons, protons and heavy charged particles (HCP). By its interaction with the structures of the spacecraft, this field may be modified inside the crew cabin. Therefore, calibration of TL detectors against a dose of gamma-rays is not sufficient for relating the TL readout to absorbed dose or to quantities relevant in radiation protection, without suitable correction. We introduce and calculate the detection efficiency, eta, relative to gamma-ray dose, of lithium fluoride detectors after proton and heavy charged particle (HCP) irradiation. We calculate eta for MCP-N (LiF:Mg,Cu,P) and for MTS-N (LiF:Mg,Ti) using microdosimetric models. The microdosimetric distributions used in these models (for HCP of charges between Z=1 to Z=8 and in the energy range between 0.3 MeV/amu and 20 MeV/amu) are calculated using an analytical model, based on the results of Monte Carlo simulated charged particle tracks using the MOCA-14 code. The ratio etaMCP-N/etaMTS-N for protons of stopping power (in water) below 10 keV/microm lies in the range between 0.65 and 1.0 and for HCP with Z>1--between 0.3 and 0.6. The stopping power of the particle is found not to be a unique parameter to scale the response of TL detectors. The combination of response of LiF:Mg,Cu,P and LiF:Mg,Cu,P detectors can be more suitable for a dose correction in space radiation fields.
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PMID:Modeling the response of thermoluminescence detectors exposed to low- and high-LET radiation fields. 1279 31

Lithium fluoride thermoluminescent (TL) detectors, with Li-7 isotope and various activators (MTS-7 LiF:Mg,Ti, MTT-7 LiF:Mg,Ti with enhanced Ti concentration and MCP-7 LiF:Mg,Cu,P) were used for dosimetry of heavy charged particles, within the ICHIBAN experiment. The microdosimetric model has been applied to calculate detection efficiency, eta, relative to gamma-ray dose, of these detectors after proton and heavy charged particle (HCP) irradiation for ion charges ranging from Z = 1 to Z = 6 and in the energy range from 0.3 to 20 MeV amu(-1). The calculated ratio eta(MCP-7)/eta(MTS-7) lies in the range between 0.2 and 1.0 for protons and between 0.2 and 0.4 for HCP with Z > 1. The calculated value of eta(MTT-7)/eta(MTS-7) for protons was found range between 1.0 and 1.45 and, for Z > 1, between 1.3 and 2. These relationships can be applied to derive information about the 'effective LET' in an unknown HCP field and to correct the TLD readings for dose evaluation.
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PMID:Dosimetry of heavy charged particles with thermoluminescence detectors--models and applications. 1535 66