Abstract：
:To evaluate the dose distributions of an electron microbeam and to help optimization of its design, the condensed-history (CH) Monte Carlo simulation algorithm implemented in the Geant4 toolkit was selected as an alternative to the conventionally used analog algorithm. Compared to the analog algorithm, the CH algorithm is cheaper and less limited by the lack of cross-sections. And, with a properly chosen production cut for secondaries, its accuracy for the problems of microdosimetry is satisfactory. In this work, calculations of the single-event (imparted energy epsilon) size distribution f (1)(epsilon) is described, for compartments in the Orlando electron micro beam. The results agree well with those obtained by use of the analog algorithm and reported in the literature. It is shown that substituting tissue with water in HeLa cells, and replacing Mylar with water of the same mass stopping power in the substrate, makes little difference. Additionally, the neighbor-to-target ratio of average event size R (NT) has been calculated as a function of the incident energy of the electrons. Comparison with analog results reported in the literature suggests that the average event size in neighbors, and hence the neighbor-to-target ratio, is sensitive to the selection of the energy threshold. Finally, the effect of finite beam radius on the event size distribution and the neighbor-to-target ratio has also been studied. All results presented suggest the condensed-history technique to provide an efficient and valuable alternative tool in the design of electron microbeams.
journal_name
Radiat Environ Biophysjournal_title
Radiation and environmental biophysicsauthors
Ma Y,Zhou H,Zhuo Ydoi
10.1007/s00411-006-0027-6keywords:
subject
Has Abstractpub_date
2006-03-01 00:00:00pages
299-305issue
4eissn
0301-634Xissn
1432-2099journal_volume
44pub_type
杂志文章abstract：:Procedures for age-adjustment of cancer fractions are proposed which do not require fixed age intervals. The full available information on survival times can then be used, which is especially important in small treatment groups. For incidental cancers a non-decreasing prevalence function and for fatal cancers the Kapl...
journal_title：Radiation and environmental biophysics
pub_type： 杂志文章
doi：10.1007/s00411-004-0250-y
更新日期：2004-09-01 00:00:00
abstract：:The model of radiocaesium transfer to sheep presented by Galer et al. provides reliable predictions only for sheep of a similar body weight to those used in the development of the model (approximately 30 kg). To extend the applicability of the model, it was necessary to re-parameterise it in terms of activity concentr...
journal_title：Radiation and environmental biophysics
pub_type： 杂志文章
doi：10.1007/BF01211238
更新日期：1996-02-01 00:00:00
abstract：:An inter-comparison of five models designed to predict the effect of ionizing radiation on populations of non-human wildlife, performed under the IAEA EMRAS II programme, is presented and discussed. A benchmark scenario 'Population response to chronic irradiation' was developed in which stable generic populations of m...
journal_title：Radiation and environmental biophysics
pub_type： 杂志文章
doi：10.1007/s00411-012-0430-0
更新日期：2012-11-01 00:00:00
abstract：:The radiation-induced process of strand breaks on pBR322 plasmid DNA in aqueous solution for different energy electrons was studied by Monte Carlo simulation. Assumptions of induction mechanisms of single- and double-strand breaks (SSBs and DSBs) used in the simulation are that SSB is induced by OH or H reaction with ...
journal_title：Radiation and environmental biophysics
pub_type： 杂志文章
doi：10.1007/s00411-002-0161-8
更新日期：2002-09-01 00:00:00
abstract：:In mice, persisting radiation-induced growth retardation of hematopoietic tissue suggested that at least part of the surviving stem cells are genetically injured. Additional mitotic stress some time after the radiation insult might remove injured stem cells, thus improving the overall recovery of the irradiated bone m...
journal_title：Radiation and environmental biophysics
pub_type： 杂志文章
doi：10.1007/BF01211410
更新日期：1987-01-01 00:00:00
abstract：:In this study, temporal variations of indoor radon concentrations in Bulgaria were investigated. The radon concentrations were measured by nuclear track detectors as part of the Bulgarian National Survey, performed in the dwellings of 28 regional districts. The detectors were exposed through a year in two consecutive ...
journal_title：Radiation and environmental biophysics
pub_type： 杂志文章
doi：10.1007/s00411-019-00789-y
更新日期：2019-08-01 00:00:00
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journal_title：Radiation and environmental biophysics
pub_type： 杂志文章
doi：10.1007/BF01324267
更新日期：1980-01-01 00:00:00
abstract：:This study was undertaken to investigate the mechanism of chemical radiosensitization by halogenated bases incorporated into DNA. Radiation-induced base and sugar-phosphate backbone damage to 5-bromouridine-5'-monophosphate (5-BrUMP) was monitored using a flow system connected in series with a recording spectrophotome...
journal_title：Radiation and environmental biophysics
pub_type： 杂志文章
doi：10.1007/BF01211508
更新日期：1992-01-01 00:00:00
abstract：:Microwave irradiation has been shown to decrease the input resistance of snail neurons. In this study, we examined the role of extracellular calcium in triggering the microwave-induced enhancement of membrane conductance. Two sets of experiments were conducted. In the first set, nerve cells were superfused using Ringe...
journal_title：Radiation and environmental biophysics
pub_type： 杂志文章
doi：10.1007/BF01229821
更新日期：1985-01-01 00:00:00
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journal_title：Radiation and environmental biophysics
pub_type： 杂志文章
doi：10.1007/BF01326755
更新日期：1975-01-01 00:00:00
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journal_title：Radiation and environmental biophysics
pub_type： 杂志文章
doi：10.1007/s00411-008-0194-8
更新日期：2009-02-01 00:00:00
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journal_title：Radiation and environmental biophysics
pub_type： 杂志文章
doi：10.1007/s00411-020-00854-x
更新日期：2020-08-01 00:00:00
abstract：:At five stages of gestation, mice were exposed dorsally to ultrasonic irradiation at 1 W/cm2 (spatial and temporal average), 2 MHz, and 34 and 37 degrees C (temperature at beginning of exposure). The results indicated that ultrasonic exposure up to at least 100 s is not hazardous to a pregnant mouse or its offspring i...
journal_title：Radiation and environmental biophysics
pub_type： 杂志文章
doi：10.1007/BF01323651
更新日期：1980-01-01 00:00:00
abstract：:The relationship between occupational exposure to extremely low-frequency electromagnetic fields and adult leukaemia has been studied extensively during the last decade. The first studies were based on crude exposure assessments, estimated through job titles, with no or only limited control confounding factors. The re...
journal_title：Radiation and environmental biophysics
pub_type： 杂志文章,评审
doi：10.1007/s004110050036
更新日期：1996-11-01 00:00:00
abstract：:Blue (F450) and green (F530) leaf fluorescence were studied together with the red chlorophyll fluorescence (emission maxima F690 and F735) during light-induced chlorophyll fluorescence induction kinetics (Kautsky effect) in predarkened leaves of wheat (Triticum aestivum L.) and soybean (Glycine max L.). The intensity ...
journal_title：Radiation and environmental biophysics
pub_type： 杂志文章
doi：10.1007/BF01225923
更新日期：1993-01-01 00:00:00
abstract：:Osteosarcoma is the most frequent secondary malignancy following radiotherapy of patients with bilateral retinoblastoma. This suggests that the Rb1 tumour suppressor gene might confer genetic susceptibility towards radiation-induced osteosarcoma. To define the contribution of the Rb1 pathway in the multistep process o...
journal_title：Radiation and environmental biophysics
pub_type： 杂志文章
doi：10.1007/s00411-010-0339-4
更新日期：2011-03-01 00:00:00
abstract：:The aim of this study was to verify whether extremely low frequency (ELF) magnetic fields (MF) could affect transposition activity like some environmental stress factors such as heat shock or UV irradiation. Using an Escherichia coli Lac Z(-) strain transformed with a plasmid containing a Tn 10 derivative element expr...
journal_title：Radiation and environmental biophysics
pub_type： 杂志文章
doi：10.1007/s00411-003-0192-9
更新日期：2003-07-01 00:00:00
abstract：:Native horseradish peroxidase, as well as its reduced and carboxymethylated form, and the apoenzyme, showed resistance to photodynamic action. Sensitivity to this action was detected only in reduced and carboxymethylated apoenzyme, when the photooxidation of its histidine residues was observed. When analyzing the bulk...
journal_title：Radiation and environmental biophysics
pub_type： 杂志文章
doi：10.1007/BF01212653
更新日期：1985-01-01 00:00:00
abstract：:Most of plutonium released by nuclear explosions is Pu-241 which decays to Am-241. We have studied the deposition of Pu-241 and Am-241 in lichens collected since 1958 in the central part of Sweden (62.3 degrees N, 12. 4 degrees E). Comparative studies with Pu-isotopes, Pu-239 + 240 and Pu-238 were also performed. In 1...
journal_title：Radiation and environmental biophysics
pub_type： 杂志文章
doi：10.1007/BF02176794
更新日期：1978-10-12 00:00:00
abstract：:Dose conversion coefficients (DCCs) for assessment of internal and external radiation exposures to terrestrial and aquatic biota are compiled for 75 radionuclides, for 14 terrestrial and 22 aquatic reference organisms. DCC values for internal exposure are calculated based on a homogeneous distribution of the radionucl...
journal_title：Radiation and environmental biophysics
pub_type： 杂志文章
doi：10.1007/s00411-008-0159-y
更新日期：2008-04-01 00:00:00
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journal_title：Radiation and environmental biophysics
pub_type： 杂志文章
doi：10.1007/BF01407598
更新日期：1984-01-01 00:00:00
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journal_title：Radiation and environmental biophysics
pub_type： 杂志文章
doi：10.1007/BF01331176
更新日期：1976-12-23 00:00:00
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journal_title：Radiation and environmental biophysics
pub_type： 杂志文章
doi：10.1007/BF01323421
更新日期：1975-12-04 00:00:00
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journal_title：Radiation and environmental biophysics
pub_type： 杂志文章
doi：10.1007/s00411-010-0267-3
更新日期：2010-05-01 00:00:00
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journal_title：Radiation and environmental biophysics
pub_type： 杂志文章
doi：10.1007/s00411-016-0670-5
更新日期：2017-03-01 00:00:00
abstract：:Waterborne radioactive releases into the Techa River from the Mayak Production Association in Russia during 1949-1956 resulted in significant doses to about 30,000 persons who lived in downstream settlements. The residents were exposed to internal and external radiation. Two methods for reconstruction of the external ...
journal_title：Radiation and environmental biophysics
pub_type： 杂志文章
doi：10.1007/s00411-015-0611-8
更新日期：2015-11-01 00:00:00
abstract：:Frequently knowledge of elemental content of human organs and tissues is required for a variety of applications. These can include brachytherapy and radiotherapy planning, radiation dosimetry and radiation protection. Revised reference values of chemical element mass fractions in normal and cancerous prostate tissues ...
journal_title：Radiation and environmental biophysics
pub_type： 杂志文章
doi：10.1007/s00411-020-00884-5
更新日期：2021-01-02 00:00:00
abstract：:The lethal effects of high-voltage capacitor-discharges in suspensions of E. coli K12 with varying electrolytes have been examined. A reduction of more than 99.9% of living cells, dependent on the applied voltage could be proved. The bactericidal action is assumed to be due to direct effects of high electric fields. E...
journal_title：Radiation and environmental biophysics
pub_type： 杂志文章
doi：10.1007/BF01324271
更新日期：1980-01-01 00:00:00
abstract：:The effect of negative pions (peak and plateau), photons (140 kV and 29 MeV), and 20 MeV electrons on the proliferative capacity of Ehrlich ascites carcinoma cells was investigated. Proliferative survival curves plotted for the modalities employed are presented. Under the experimental conditions used, the peak pions w...
journal_title：Radiation and environmental biophysics
pub_type： 杂志文章
doi：10.1007/BF01358287
更新日期：1979-08-10 00:00:00
abstract：:The hypoxic cytotoxic effect of chlorpromazine towards E. coli B/r was observed to be dependent on temperature of incubation and irradiation. Increasing the temperature of incubation from ambient to 37 degrees C followed by irradiation revealed that the organisms showed radiosensitivity of a magnitude which was two to...
journal_title：Radiation and environmental biophysics
pub_type： 杂志文章
doi：10.1007/BF01229816
更新日期：1985-01-01 00:00:00
