Abstract:
:Two different sets of Monte Carlo computations were carried out for the study of dose penetration of monoenergetic, low-energy (10 to 100 keV) photon beams incident on slabs of tissue. One program took into account coherent scattering and considered electron binding when finding the angle of scattering during incoherent scattering; the other simpler program, customarily used at higher energies, largely ignored these effects. For calculations at the source photon energy of 100 keV, it was found that there was negligible difference in dose distribution in the slab between the more and less complex type of calculations. The same thing was found to be true for the 30 and 10-keV source photon energies only for shallow penetration distances; and at deeper penetrations the simple approach tended to overestimate the dose appreciably. It is concluded that for penetration of low-energy photon beams into tissue, accurate calculational results cannot be assured with the neglect of coherent scattering effects and electron binding considerations in determining the scattering angles except for shallow depths of penetration.
journal_name
Radiat Resjournal_title
Radiation researchauthors
Beernink KP,Nelson RF,Chilton ABsubject
Has Abstractpub_date
1983-11-01 00:00:00pages
429-34issue
2eissn
0033-7587issn
1938-5404journal_volume
96pub_type
杂志文章abstract::Single-strand breaks (SSBs) and double-strand breaks (DSBs) induced in DNA under phosphorus K-shell resonant absorption have been studied using supercoiled plasmids. The kinetics of the production of SSBs and DSBs exhibits a linear and a quadratic dependence, respectively, on photon fluence. Cross sections and quantum...
journal_title:Radiation research
pub_type: 杂志文章
doi:
更新日期:1996-05-01 00:00:00
abstract::Single crystals of disodium beta-glycerophosphate pentahemihydrate (betaGP), Na2x(HO)CH2CH(PO(4)2-)CH2(OH)x5 1/2H2O, were X-irradiated at 77 and 280 K. EPR, ENDOR and FSE techniques were used to study the formation of free radicals in these irradiated crystals to characterize possible reaction mechanisms leading to de...
journal_title:Radiation research
pub_type: 杂志文章
doi:
更新日期:1998-08-01 00:00:00
abstract::We have tested an 836.55 MHz field with North American Digital Cellular (NADC) modulation in a 2-year animal bioassay that included fetal exposure. In offspring of pregnant Fischer 344 rats, we tested both spontaneous tumorigenicity and the incidence of induced central nervous system (CNS) tumors after a single dose o...
journal_title:Radiation research
pub_type: 杂志文章
doi:
更新日期:1999-09-01 00:00:00
abstract::We have studied the effects of dose rate and dose fractionation on murine pulmonary alveolar macrophage colony-forming cells (AL-CFC). The dose-response curve of AL-CFC to ionizing irradiation has a Dq of about 100 rad, reflecting the cells' ability to repair sublethal damage. For comparison, we investigated the effec...
journal_title:Radiation research
pub_type: 杂志文章
doi:
更新日期:1985-08-01 00:00:00
abstract::To elucidate the nature and kinetics of DNA strand breaks caused by low-energy Auger electron emitters, we compared the yields of DNA breaks in supercoiled pUC19 DNA in the presence of the (.)OH scavenger dimethyl sulfoxide (DMSO) after the decay of (125)I (1) in proximity to DNA after minor-groove binding ((125)I-iod...
journal_title:Radiation research
pub_type: 杂志文章
doi:
更新日期:1999-11-01 00:00:00
abstract::Characteristic of damage introduced in DNA by ionizing radiation is the induction of a wide range of lesions. Single-strand breaks (SSBs) and base damages outnumber double-strand breaks (DSBs). If unrepaired, these lesions can lead to DSBs and increased mutagenesis. XRCC1 and DNA polymerase beta (polbeta) are thought ...
journal_title:Radiation research
pub_type: 杂志文章
doi:10.1667/RR0750.1
更新日期:2007-09-01 00:00:00
abstract::This laboratory previously demonstrated that hyperbaric oxygen and hyperbaric carbogen improved oxygenation in the R3230Ac tumor, but normobaric 100% O2 and carbogen did not. The current study assessed tumor growth after exposure to radiation plus either hyperbaric oxygen, carbogen or carbogen/nicotinamide and the rel...
journal_title:Radiation research
pub_type: 杂志文章
doi:
更新日期:1997-06-01 00:00:00
abstract::In this study, we sought to determine how diffusion-weighted imaging (DWI) and proton magnetic resonance spectroscopy (1H-MRS) features are associated with histopathological results, and explored the cellular mechanisms of DWI and 1H-MRS in early radiosensitivity of transplanted liver tumors. VX2 tumors were implanted...
journal_title:Radiation research
pub_type: 杂志文章
doi:10.1667/RR15140.1
更新日期:2019-01-01 00:00:00
abstract::1. A survival curve for the colony-forming ability of mouse bone marrow cells irradiated in vivo with Co60 gamma-rays has been obtained. The curve may be characterized by D0 of 95 rads and an extrapolation number of 1.5. 2. Comparison with the survival curve obtained for irradiated in vitro indicated a statistically s...
journal_title:Radiation research
pub_type: 杂志文章
doi:
更新日期:1962-06-01 00:00:00
abstract::Although skin is usually exposed during human exposures to ionizing radiation, there have been no thorough examinations of the transcriptional response of skin fibroblasts and keratinocytes to radiation. The transcriptional response of quiescent primary fibroblasts and keratinocytes exposed to from 10 cGy to 5 Gy and ...
journal_title:Radiation research
pub_type: 杂志文章
doi:10.1667/RR1677.1
更新日期:2009-07-01 00:00:00
abstract::In light-ion radiation therapy, both the dose and the local energy spectrum, which is often characterized with the linear energy transfer (LET), must be considered. In treatment optimization, it is advantageous to use a radiobiological model that analytically accounts for both dose and LET for the ion type of interest...
journal_title:Radiation research
pub_type: 杂志文章
doi:10.1667/RR2045.1
更新日期:2010-10-01 00:00:00
abstract::Ionizing radiations induce mutations which can be detected both in coding sequences (Hprt locus) by measuring the frequency of 6-thioguanine-resistant cells and in minisatellite sequences by DNA fingerprint analysis. We analyzed the effects of irradiation with low-energy protons (31 keV/pm) and, for comparison, with u...
journal_title:Radiation research
pub_type: 杂志文章
doi:
更新日期:1997-09-01 00:00:00
abstract::Tumor radiotherapy with large-field irradiation results in an increase of p53-dependent apoptosis of the radiosensitive hematopoietic stem cells. Proapoptotic PUMA is a transcriptional target of p53. Thus suppression of PUMA expression by gene therapy with the transcription repressor SNAI2 as transgene might be a pote...
journal_title:Radiation research
pub_type: 杂志文章
doi:10.1667/RR1952.1
更新日期:2010-05-01 00:00:00
abstract::The German Thorotrast study comprises 2,326 patients and 1,890 controls. Forty-eight Thorotrast patients and 239 controls are still alive and are invited for a follow-up examination every 2 years. In the deceased patients, the following neoplastic diseases with excess rates were registered (Thorotrast/controls): liver...
journal_title:Radiation research
pub_type: 杂志文章
doi:
更新日期:1999-12-01 00:00:00
abstract::We used Restriction Landmark Genome Scanning (RLGS) to assess, on a genome-wide basis, the mutation induction rate in mouse germ cells after radiation exposure. Analyses of 1,115 autosomal NotI DNA fragments per mouse for reduced spot intensity, indicative of loss of one copy, in 506 progeny derived from X-irradiated ...
journal_title:Radiation research
pub_type: 杂志文章
doi:10.1667/rr3146
更新日期:2004-04-01 00:00:00
abstract::The stable free radical 4-oxo-2,2,6,6-tetramethylpiperidinooxy (2,2,6,6-tetramethylpiperidone-N-oxyl, TEMPONE) in nitrous oxide-saturated aqueous formate solution has been shown to be a quantitative dosimeter for in situ radiolysis electron spin resonance (ESR) studies. The bleach of the TEMPONE ESR signal is proporti...
journal_title:Radiation research
pub_type: 杂志文章
doi:
更新日期:1997-03-01 00:00:00
abstract::We previously reported that a priming dose of 0.3 Gy on gestation day 11 significantly increased the rate of living fetuses and reduced the incidence of congenital malformations caused by exposure to 5 Gy X rays on gestation day 12 in ICR mice. In the present study, postnatal development of the live offspring was inve...
journal_title:Radiation research
pub_type: 杂志文章
doi:
更新日期:1999-08-01 00:00:00
abstract::The alveolar type II cell is one of the critical cells for radiation damage in the lungs after inhalation of radioactive aerosols. With the aid of a Quantimet-970 image analyzer and a VAX-11/780 computer, we calculated the radiation dose to rat alveolar type II cells from alpha particles emitted by 239PuO2. A series o...
journal_title:Radiation research
pub_type: 杂志文章
doi:
更新日期:1989-11-01 00:00:00
abstract::Chinese hamster ovary (CHO) cells were exposed to various concentrations of diethylmaleate (DEM) during a 42 degrees C incubation to determine if glutathione (GSH) compartmentalization was a factor in modification of thermal sensitivity. Cytoplasmic and mitochondrial GSH were isolated from CHO cells immediately after ...
journal_title:Radiation research
pub_type: 杂志文章
doi:
更新日期:1988-09-01 00:00:00
abstract::We present measurements of low-energy (<18 eV) electron-stimulated desorption of anions from acetamide (CH(3)CONH(2)) and dimethyl disulfide [DMDS: (CH(3)S)(2)] films. Electron irradiation of physisorbed CH(3)CONH(2) produces H(-), CH(3)(-) and O(-) anions, whereas the H(-), CH(2)(-), CH(3)(-), S(-), SH(-) and SCH(3)(...
journal_title:Radiation research
pub_type: 杂志文章
doi:10.1667/0033-7587(2002)158[0023:aopsib]2.0.co;2
更新日期:2002-07-01 00:00:00
abstract::The natural survival, relative to properly chosen controls, of 26 beagle dogs injected once intravenously with an average of 0.58 +/- 0.04 kBq 239Pu/kg, 23 dogs injected with 2.31 +/- 0.43 kBq 226Ra/kg, 13 dogs injected with 1.84 +/- 0.26 kBq 228Ra/kg, 12 dogs injected with 0.56 +/- 0.030 kBq 228Th/kg, and 12 dogs inj...
journal_title:Radiation research
pub_type: 杂志文章
doi:
更新日期:1991-06-01 00:00:00
abstract::The linear no-threshold extrapolation from a dose-response relationship for ionizing radiation derived at higher doses to doses for which regulatory standards are proposed is being challenged by some scientists and defended by others. It appears that the risks associated with exposures to doses of interest are below t...
journal_title:Radiation research
pub_type:
doi:
更新日期:1998-12-01 00:00:00
abstract::Exposure to ionizing radiation alone or combined with traumatic tissue injury is a crucial life-threatening factor in nuclear and radiological incidents. Radiation injuries occur at the molecular, cellular, tissue and systemic levels; their mechanisms, however, remain largely unclear. Exposure to radiation combined wi...
journal_title:Radiation research
pub_type: 杂志文章
doi:10.1667/RR14647.1
更新日期:2017-11-01 00:00:00
abstract::Numerous studies have shown that histone deacetylase inhibitors (HDACis) improve cellular acetylation while also enhancing the radiation sensitivity. In this work, however, we confirmed that low-dose trichostatin A (TSA) as a typical HDACi could reduce rather than increase the radiosensitivity of cancer cells, while t...
journal_title:Radiation research
pub_type: 杂志文章
doi:10.1667/RADE-20-00145.1
更新日期:2021-01-29 00:00:00
abstract::Dose-response curves for micronucleus (MN) formation were measured in Chinese hamster V79 and xrs6 (Ku80(-)) cells and in human mammary epithelial MCF10A cells in the dose range of 0.05-1 Gy. The Chinese hamster cells were exposed to 1 GeV/nucleon iron ions, 600 MeV/nucleon iron ions, and 300 MeV/nucleon iron ions (LE...
journal_title:Radiation research
pub_type: 杂志文章
doi:10.1667/RR0967.1
更新日期:2007-12-01 00:00:00
abstract::Human blood cultures were exposed to a 1.9 GHz continuous-wave (CW) radiofrequency (RF) field for 2 h using a series of six circularly polarized, cylindrical waveguides. Mean specific absorption rates (SARs) of 0.0, 0.1, 0.26, 0.92, 2.4 and 10 W/kg were achieved, and the temperature within the cultures during a 2-h ex...
journal_title:Radiation research
pub_type: 杂志文章
doi:10.1667/0033-7587(2002)158[0523:ddamii]2.0.co;2
更新日期:2002-10-01 00:00:00
abstract::While the risk of lung cancer associated separately with smoking and radiation exposure has been widely reported, it is not clear how smoking and radiation together contribute to the risk of specific lung cancer histological types. With individual smoking histories and radiation dose estimates, we characterized the jo...
journal_title:Radiation research
pub_type: 杂志文章
doi:10.1667/rr2819.1
更新日期:2012-09-01 00:00:00
abstract::The neon beam at 250 MeV/nucleon from the Bevalac at the Lawrence Berkeley Laboratory is bombarded in nuclear emulsion. The experimental interaction cross section of the neon beam in emulsion is 1078 +/- 35 mb, in agreement with the calculations from the modified Bradt and Peters formula. The secondary fragments were ...
journal_title:Radiation research
pub_type: 杂志文章
doi:
更新日期:1985-09-01 00:00:00
abstract::Three somatic mutation assays were evaluated in men exposed to low-dose, whole-body, ionizing radiation. Blood samples were obtained between 1992 and 1999 from 625 Russian Chernobyl cleanup workers and 182 Russian controls. The assays were chromosome translocations in lymphocytes detected by FISH, hypoxanthine phospho...
journal_title:Radiation research
pub_type: 杂志文章
doi:10.1667/0033-7587(2002)158[0424:tsgbac]2.0.co;2
更新日期:2002-10-01 00:00:00
abstract::Radiation of the esophagus of C3H/HeNsd mice with 35 or 37 Gy of 6 MV X rays induces significantly increased RNA transcription for interleukin 1 (Il1), tumor necrosis factor alpha (Tnf), interferon gamma inducing factor (Ifngr), and interferon gamma (Ifng). These elevations are associated with DNA damage that is detec...
journal_title:Radiation research
pub_type: 杂志文章
doi:10.1667/0033-7587(2001)155[0002:morice]2.0.co;2
更新日期:2001-01-01 00:00:00