Abstract：
:Single crystals of the co-crystalline complex of 1-methyluracil and 9-ethyladenine were X-irradiated and studied using EPR, ENDOR and FSE spectroscopic techniques at 10 K. All together seven radicals were identified, and experimental evidence for at least one more species, as well as for a very low population of radical pairs, is available. Oxidation and reduction products appear to be stabilized at both base constituents of the pair. Of the 1-methyluracil moiety, the product formed by net hydrogen abstraction from the methyl group was observed, together with the 1-methyluracil anion and the 1-methyluracil-5-yl radical. From the 9-ethyladenine moiety, the N3-protonated 9-ethyladenine anion is stabilized. In addition, the 9-ethyladenine cation as well as traces of the amino-deprotonated cation were observed, together with the C8-H hydrogen adduct. The presence of oxidation and reduction products in each of the two bases may indicate that negligible energy transfer takes place between them. This behavior is different from that observed in the similar pair of 1-methylthymine-9-methyladenine. There also seems to be minor proton exchange between the two stacks of molecules: Interbase protonation-deprotonation channeled through the hydrogen-bonding scheme seems to be almost completely suppressed.
journal_name
Radiat Resjournal_title
Radiation researchauthors
Sagstuen E,Hole EO,Nelson WH,Close DMsubject
Has Abstractpub_date
1998-02-01 00:00:00pages
120-7issue
2eissn
0033-7587issn
1938-5404journal_volume
149pub_type
杂志文章abstract：:The molecular structure of mutants induced in human lymphoblast cells by 500 cGy X rays in the presence of the radioprotector cysteamine (25 mM) has been compared with that induced by an equally mutagenic treatment of 150 cGy X rays alone. Sets of mutants at the hypoxanthine-guanine phosphoribosyl transferase locus we...
journal_title：Radiation research
pub_type： 杂志文章
doi：
更新日期：1989-05-01 00:00:00
abstract：:New data are given on the use of oxalic acid, in light and heavy water solutions, for in-pile chemical dosimetry. The method of calculating the absorbed doses in low-Z materials is described. Results of chemical measurements in the core of the heavy-water-moderated reactor at Vinca (Yugoslavia) are compared with the r...
journal_title：Radiation research
pub_type： 杂志文章
doi：
更新日期：1968-12-01 00:00:00
abstract：:Our data (Reddy et al., Radiat. Res. 141, 252-258, 1995) on the kinetics of the repair of potentially lethal damage in log-phase Chinese hamster V79 cells are used to test some predictions which arise from the different assumptions of the repair-misrepair (RMR) (C. A. Tobias, Radiat. Res. 104, S77-S95, 1985), lethal-p...
journal_title：Radiation research
pub_type： 杂志文章
doi：
更新日期：1997-09-01 00:00:00
abstract：:Keratinocyte growth factor (FGF7, also known as KGF) ameliorates the radiation response of mouse oral mucosa and other epithelial tissues. However, the precise mechanisms remain unclear. The aim of the present study was to investigate the effect of FGF7 on the survival and colony size of normal human epidermal keratin...
journal_title：Radiation research
pub_type： 杂志文章
doi：10.1667/0033-7587(2001)156[0761:eokgfo]2.0.co;2
更新日期：2001-12-01 00:00:00
abstract：:Plutonium is considered to be a carcinogen because it emits alpha particles that may result in the irradiation of stem cell population. In the present study we show that plutonium can also catalyze reactions that induce hydroxyl radicals in the absence of significant alpha-particle irradiation. Using the low specific ...
journal_title：Radiation research
pub_type： 杂志文章
doi：
更新日期：1994-01-01 00:00:00
abstract：:The effect of extremely low-frequency electromagnetic field (ELF EMF) exposures to human health has been widely debated. Epidemiological studies have found a possible correlation between increased cancer incidence and environmental ELF EMF exposures. Results from in vitro studies performed to examine the possible unde...
journal_title：Radiation research
pub_type： 杂志文章
doi：10.1667/0033-7587(2000)153[0663:eodctl]2.0.co;2
更新日期：2000-05-01 00:00:00
abstract：:A new model for the survival of bacteria exposed to ionizing radiation is constructed in the framework of a target theory based on microdosimetric concepts, where single- and double-strand breaks of DNA and their repair in vivo can be described consistently in terms of the microdosimetric quantity j (number of effecti...
journal_title：Radiation research
pub_type： 杂志文章
doi：
更新日期：1985-04-01 00:00:00
abstract：:Determinations of the LET distribution, phi(L), of charged particles within a spacecraft in low-Earth orbit have been made. One method used a cylindrical tissue-equivalent proportional counter (TEPC), with the assumption that for each measured event, lineal energy, y, is equal to LET and thus phi(L) = phi(y). The othe...
journal_title：Radiation research
pub_type： 杂志文章
doi：10.1667/0033-7587(2001)156[0310:coldmi]2.0.co;2
更新日期：2001-09-01 00:00:00
abstract：:An analysis was conducted of 27,982 deaths among 106,020 persons employed at four Federal nuclear plants in Oak Ridge, Tennessee, between 1943 and 1985. The main objectives were to extend the evaluation of the health effects of employment in the nuclear industry in Oak Ridge to include most workers who were omitted fr...
journal_title：Radiation research
pub_type： 杂志文章
doi：
更新日期：1997-07-01 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：:The placental transfer and distribution of 241Am in the feto-placental system were studied in pregnant rats. Rats were injected intravenously with 241Am citrate at 15 or 18 days of gestation. Groups injected at 15 days of gestation were sacrificed 2, 24, 48, or 120 hr after injection, and the group injected at 18 days...
journal_title：Radiation research
pub_type： 杂志文章
doi：
更新日期：1983-04-01 00:00:00
abstract：:Total-body irradiation (TBI) induces an increase in levels of granulocytes and cortisol in blood. To explore the underlying mechanisms, we studied 26 patients who had TBI prior to bone marrow transplantation. Our findings suggest that only a high dose of TBI (10 Gy) was capable of activating the hypothalamo-pituitary ...
journal_title：Radiation research
pub_type： 杂志文章
doi：
更新日期：1994-09-01 00:00:00
abstract：:A computer model that simulates the killing of exponentially growing cells by low-dose-rate radiation is described. The model incorporates cell killing by single-hit damage and double-hit (sublethal) damage, as well as repair of sublethal damage, delay of cell cycle progression, blockage and increased sensitivity of c...
journal_title：Radiation research
pub_type： 杂志文章
doi：
更新日期：1990-11-01 00:00:00
abstract：:Some cells have been reported to show greater resistance to drugs or radiation when growing with close intercellular contacts in spheroids or in solid tumors than when growing with few intercellular contacts in sparse cultures. In some cases this increased resistance reflects an increased capacity of cells in close co...
journal_title：Radiation research
pub_type： 杂志文章
doi：
更新日期：1986-09-01 00:00:00
abstract：:Proton exposure induces mutations and cancer, which are presumably linked. Because protons are abundant in the space environment and significant uncertainties exist for the effects of space travel on human health, the purpose of this study was to identify the types of mutations induced by exposure of mammalian cells t...
journal_title：Radiation research
pub_type： 杂志文章
doi：10.1667/RR3174.1
更新日期：2013-05-01 00:00:00
abstract：:Trp53 heterozygous mice are radiation-sensitive and cancer-prone. Groups of 7-8-week-old female Trp53 heterozygous mice were exposed to 4 Gy of 60Co gamma radiation at high (0.5 Gy/min) or low (0.5 mGy/min) dose rate. Other groups received 10 or 100 mGy at low dose rate 24 h prior to the 4-Gy dose. Tumor frequency and...
journal_title：Radiation research
pub_type： 杂志文章
doi：10.1667/rr3190
更新日期：2004-07-01 00:00:00
abstract：:Serum copper concentration was evaluated as an index of lung injury (monitored by lung prostacyclin production) with respect to the effects of time, dose, dose fractionation, and penicillamine dose modification in rats irradiated to the right hemithorax. Both lung PGI2 production and serum Cu concentration increased w...
journal_title：Radiation research
pub_type： 杂志文章
doi：
更新日期：1988-06-01 00:00:00
abstract：:Radiation nephropathy is one of the common late effects in cancer survivors who received radiotherapy as well as in victims of radiation accidents. The clinical manifestations of radiation nephropathy occur months after exposure. To date, there are no known early biomarkers to predict the future development of radiati...
journal_title：Radiation research
pub_type： 杂志文章
doi：10.1667/RR14828.1
更新日期：2017-12-01 00:00:00
abstract：:Thymic explant cultures were used to study the radiosensitivity of nonlymphoid thymic components in dogs. Thymic fragments from fetal (50 days gestation), newborn, and juvenile (70 days old) dogs were irradiated in vitro at 0, 0.5, 1, 2, or 4 Gy prior to culture. Colonies were classified as epithelial, spindle, or mix...
journal_title：Radiation research
pub_type： 杂志文章
doi：
更新日期：1988-07-01 00:00:00
abstract：:The possibility of a large-scale acute radiation exposure necessitates the development of new methods that could provide rapid individual dose estimates with high sample throughput. The focus of the study was an intercomparison of laboratories' dose-assessment performances using gene expression assays. Lithium-heparin...
journal_title：Radiation research
pub_type： 杂志文章
doi：10.1667/RR3236.1
更新日期：2013-08-01 00:00:00
abstract：:The effect of hypoxia on the induction of and recovery from damage by radiation alone and in combination with heat has been investigated using plateau-phase Chinese hamster ovary (CHO) cells. Postirradiation hypoxia reduced the potentially lethal damage recovery (PLDR) in cells irradiated under an euoxic state and com...
journal_title：Radiation research
pub_type： 杂志文章
doi：
更新日期：1985-02-01 00:00:00
abstract：:The radiation dose received by crew members in interplanetary space is influenced by the stage of the solar cycle. Using the recently developed models of the galactic cosmic radiation (GCR) environment and the energy-dependent radiation transport code, we have calculated the dose at 0 and 5 cm water depth; using a com...
journal_title：Radiation research
pub_type： 杂志文章
doi：
更新日期：1994-05-01 00:00:00
abstract：:Therapeutic irradiation of the brain can cause a progressive cognitive dysfunction that may involve defects in neurogenesis. In an effort to understand the mechanisms underlying radiation-induced stem cell dysfunction, neural precursor cells isolated from the adult rat hippocampus were analyzed for acute (0-24 h) and ...
journal_title：Radiation research
pub_type： 杂志文章
doi：10.1667/rr3112
更新日期：2004-01-01 00:00:00
abstract：:Hypoxic BP-8 murine sarcoma cells were exposed to misonidazole and/or radiation and the kinetics and extent of cell death were evaluated with the [125I]iododeoxyuridine-prelabeling assay. Cell death after treatment with lethal doses of misonidazole was rapid and essentially complete within 2 or 3 days after drug expos...
journal_title：Radiation research
pub_type： 杂志文章
doi：
更新日期：1987-07-01 00:00:00
abstract：:Our goal was to determine whether esophageal progenitor cells could be isolated from adult mouse esophagus or bone marrow and shown to home to and proliferate in the irradiated esophagus of recipient mice. Esophageal progenitor cells were isolated from adult male C3H/HeNsd or C57BL/6J green fluorescent protein (GFP(+)...
journal_title：Radiation research
pub_type： 杂志文章
doi：10.1667/rr3224
更新日期：2004-09-01 00:00:00
abstract：:The growth of certain UV-radiation-induced tumors is suppressed by T lymphocytes, but it has been proposed that non-T lymphocytes stimulate the growth of several of these tumors. In this study, the indirect effects of X irradiation on the growth of one such tumor in T-cell-deficient nude mice was tested. Even when the...
journal_title：Radiation research
pub_type： 杂志文章
doi：
更新日期：1996-12-01 00:00:00
abstract：:In higher eukaryotes, DNA double-strand breaks (DSBs) induced by ionizing radiation activate checkpoints that delay progression through the cell cycle. Compared to delays in other phases of the cell cycle, delays induced in G(2) are longer and frequently correlate with resistance to killing by radiation. Therefore, mo...
journal_title：Radiation research
pub_type： 杂志文章
doi：10.1667/RR2165.1
更新日期：2010-10-01 00:00:00
abstract：:Chomentowski, M., Kellerer, A. M. and Pierce, D. A. Radiation Dose Dependences in the Atomic Bomb Survivor Cancer Mortality Data: A Model-Free Visualization. The standard approach to obtaining nominal risk coefficients for radiation-related cancer involves fitting linear or linear-quadratic dose-response functions. Th...
journal_title：Radiation research
pub_type： 杂志文章
doi：10.1667/0033-7587(2000)153[0289:rddita]2.0.co;2
更新日期：2000-03-01 00:00:00
abstract：:An in vitro assay was used to assess cell killing and induction of neoplastic transformation in C3H 10T1/2 cells exposed to X rays and a range of monoenergetic neutrons administered at various dose rates. Curves for cell survival and induction of neoplastic transformation showed nonlinearity for cells exposed to acute...
journal_title：Radiation research
pub_type： 杂志文章
doi：
更新日期：1991-10-01 00:00:00
abstract：:Based on murine survival studies, endogenous hemopoietic spleen colony formation (E-CFU), and recovery of bone marrow and splenic granulocyte-macrophage colony-forming cells (GM-CFC), it was demonstrated that the postirradiation administration of glucan, an immunomodulator and hemopoietic stimulant, enhances the radio...
journal_title：Radiation research
pub_type： 杂志文章
doi：
更新日期：1989-01-01 00:00:00
