silicon isotopes
Dotaz
Zobrazit nápovědu
PURPOSE: The aim of this paper is to investigate the limits of LET monitoring of therapeutic carbon ion beams with miniaturized microdosimetric detectors. METHODS: Four different miniaturized microdosimeters have been used at the 62 MeV/u 12C beam of INFN Southern National Laboratory (LNS) of Catania for this purpose, i.e. a mini-TEPC and a GEM-microdosimeter, both filled with propane gas, and a silicon and a diamond microdosimeter. The y-D (dose-mean lineal energy) values, measured at different depths in a PMMA phantom, have been compared withLET¯D (dose-mean LET) values in water, calculated at the same water-equivalent depth with a Monte Carlo simulation setup based on the GEANT4 toolkit. RESULTS: In these first measurements, no detector was found to be significantly better than the others as a LET monitor. The y-D relative standard deviation has been assessed to be 13% for all the detectors. On average, the ratio between y-D and LET¯D values is 0.9 ± 0.3, spanning from 0.73 ± 0.08 (in the proximal edge and Bragg peak region) to 1.1 ± 0.3 at the distal edge. CONCLUSIONS: All the four microdosimeters are able to monitor the dose-mean LET with the 11% precision up to the distal edge. In the distal edge region, the ratio of y-D to LET¯D changes. Such variability is possibly due to a dependence of the detector response on depth, since the particle mean-path length inside the detectors can vary, especially in the distal edge region.
- MeSH
- celková dávka radioterapie MeSH
- design vybavení MeSH
- fantomy radiodiagnostické MeSH
- izotopy uhlíku terapeutické užití MeSH
- kalibrace MeSH
- metoda Monte Carlo MeSH
- miniaturizace MeSH
- počítačová simulace MeSH
- polymethylmethakrylát MeSH
- radiometrie přístrojové vybavení MeSH
- radioterapie těžkými ionty přístrojové vybavení MeSH
- voda MeSH
- Publikační typ
- časopisecké články MeSH
- srovnávací studie MeSH
The annual effective doses of aircrew members often exceed the limit of 1 mSv for the public due to the increased level of cosmic radiation at the flight altitudes, and thus, it is recommended to monitor them. Aircrew dosimetry is usually performed using special computer programs mostly based on results of Monte Carlo simulations. Contemporary, detectors are used mostly for validation of these computer codes, verification of effective dose calculations and for research purposes. One of such detectors is active silicon semiconductor deposited energy spectrometer Liulin. Output quantities of measurement with the Liulin detector are the absorbed dose in silicon D and the ambient dose equivalent H*(10); to determine it, two calibrations are necessary. The purpose of this work was to develop a calibration methodology that can be used to convert signal from the detector to D independently on calibration performed at Heavy Ion Medical Accelerator facility in Chiba, Japan.
- MeSH
- absorpce radiace MeSH
- design vybavení MeSH
- kalibrace MeSH
- kosmické záření * MeSH
- křemík MeSH
- letadla přístrojové vybavení MeSH
- lidé MeSH
- metoda Monte Carlo MeSH
- monitorování radiace přístrojové vybavení MeSH
- nadmořská výška MeSH
- neutrony MeSH
- polovodiče MeSH
- pracovní expozice analýza normy MeSH
- radiační expozice MeSH
- radionuklidy MeSH
- sluneční aktivita MeSH
- těžké ionty MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
... Reactions of enolates with carbonyl compounds: the aldol and Claisen reactions 614 -- 27 Sulfur, silicon ... ... Determining organic structures 43 -- Introduction 43 -- Mass spectrometry 46 -- Mass spectrometry detects isotopes ... ... 654 -- Further reading 654 -- Sulfur, silicon, and phosphorus in organic chemistry 656 -- Useful main ... ... contradictions 656 -- Sulfur-stabilized anions 660 -- Sulfonium salts 664 -- Sulfonium ylids 665 -- Silicon ...
Second edition xxv, 1234 stran : ilustrace ; 28 cm
- Konspekt
- Organická chemie
- NLK Obory
- chemie, klinická chemie
- NLK Publikační typ
- učebnice vysokých škol
Sensitive assay method was developed for a parallel, rapid and precise determination of the most prominent oxidative stress biomarkers: 8-iso-prostaglandin F(2alpha), malondialdehyde and 4-hydroxynonenal. The method consisted of a pre-treatment part a solid-phase extraction, for rapid and effective isolation of biomarkers from body fluids (exhaled breath condensate, plasma and urine) and the detection method LC-ESI-MS/MS, where the selected reaction monitoring mode was used for its extremely high degree of selectivity and the stable-isotope-dilution assay for its high precision of quantification. The developed method was characterized by the following parameters: the imprecision was below 14.3%, the mean inaccuracy was determined to be lower than 13.1%. The method was tested on samples obtained from patients diagnosed with asbestosis, pleural hyalinosis or silicosis, i.e. occupational lung diseases caused by fibrogenic dusts, inducing oxidative stress in the respiratory system, and then compared to samples from healthy subjects. The difference in concentration levels of biomarkers between the two groups was perceptible in all the body fluids (the difference observed in an exhaled breath condensate was statistically most significant).
- MeSH
- aldehydy analýza krev moč MeSH
- azbest toxicita MeSH
- biologické markery analýza krev moč MeSH
- dinoprost analogy a deriváty analýza krev moč MeSH
- extrakce na pevné fázi metody MeSH
- lidé středního věku MeSH
- lidé MeSH
- malondialdehyd analýza krev moč MeSH
- oxid křemičitý toxicita MeSH
- oxidační stres MeSH
- plicní nemoci etiologie krev metabolismus moč MeSH
- senioři MeSH
- studie případů a kontrol MeSH
- tandemová hmotnostní spektrometrie metody MeSH
- tělesné tekutiny chemie metabolismus MeSH
- vysokoúčinná kapalinová chromatografie metody MeSH
- Check Tag
- lidé středního věku MeSH
- lidé MeSH
- senioři MeSH
- Publikační typ
- hodnotící studie MeSH
- práce podpořená grantem MeSH
- MeSH
- finanční podpora výzkumu jako téma MeSH
- monitorování životního prostředí MeSH
- oxid křemičitý analýza chemie MeSH
- radioaktivní látky znečišťující půdu analýza MeSH
- radioizotopy cesia analýza chemie MeSH
- radiometrie metody MeSH
- silikáty hliníku analýza chemie MeSH
- Publikační typ
- srovnávací studie MeSH
... Sawczak (Poland) 110 -- Lineselective C02-lasers with variable line-spacing and variable reflectivity silicon ... ... Wang (China) 141 -- The influence of isotopic composition on emissioin spectrum of XeCI laser -- N. ...
1st ed. 209 s. ; 30 cm
... Interpretation Procedure 13 -- 1.9 General References 15 -- 2 / Elemental Composition 19 -- 2.1 Stable Isotopes ... ... ; Classification According to Natural Abundance 19 -- 2.2 “A + 2” Elements: Oxygen, Silicon, Sulfur, ... ... 11 / Solutions to Unknowns 293 -- Bibliography 321 Appendix 339 -- Table A.1 Nuclidic Masses and Isotopic ... ... Abundances 339 Table A.2 Natural Abundances of Combinations of Chlorine, Bromine, Silicon, and Sulfur ...
4th ed. xviii, 371 s. : il., tab. ; 24 cm
- MeSH
- biochemie MeSH
- klinické laboratorní techniky MeSH
- Publikační typ
- monografie MeSH
- Konspekt
- Biochemie. Molekulární biologie. Biofyzika
- NLK Obory
- biochemie
- chemie, klinická chemie
... 141 -- Aliphatic arsenic compounds 143 -- Aliphatic antimony and bismuth compounds 145 -- Aliphatic silicon ... ... Organic Compounds containing Isotopic Elements 911 -- 1. ... ... Compounds with carbon isotopes 916 -- 3. Compounds with heavy oxygen 917 -- 4. ... ... Compounds with nitrogen isotopes 918 -- Tables -- Principal compounds occurring in coal-tar 922 -- Compounds ...
4th english revis. and enlarged ed. 983 s. : il.
