WorldWideScience

Sample records for ray exposure ages

  1. Pregnancy x-rays and childhood cancers: effects of exposure age and radiation dose

    International Nuclear Information System (INIS)

    Gilman, E.A.; Kneale, G.W.; Knox, E.G.; Stewart, A.M.

    1988-01-01

    Using data from the Oxford Survey of Childhood Cancers this paper examines the effect of foetal age and number of films used on the subsequent risk of childhood cancer associated with prenatal x-rays. X-rays early in pregnancy were taken for different reasons and required more films when compared with those taken in late pregnancy. Therefore, Mantel-Haenszel techniques were used to estimate the independent effects of (a) exposure age and (b) number of films. Age at exposure had a clearly significant effect; x-rays taken in the first trimester of pregnancy were 2.69 times as effective as x-rays taken in the third trimester. First trimester exposures were often the result of maternal illnesses, so these maternal illnesses were then included among the controlling factors. When this was done the first trimester x-rays were 2.73 times as effective as later exposures. First trimester x-rays were most strongly associated with the cancers which were diagnosed between 4 and 5 years of age. Although the number of films had no detectable effect upon relative risk calculated over all ages, multiple exposures were demonstrably associated with early age at diagnosis. (author)

  2. Stony meteoroid space erosion and drag: Effect on cosmic ray exposure ages

    Science.gov (United States)

    Rubincam, David Parry

    2017-09-01

    Collisions with dust particles in retrograde orbits cause space erosion on stony meteoroids in addition to the particle drag which causes drift toward resonances. The spacing between resonances determines the maximum drift time and sets upper limits on the neon-21 cosmic ray exposure (CRE) ages for meteoroids less than ∼1 m in radius, while space erosion controls the limit for radii greater than ∼1 m; the limits accord well with the measured CRE ages of stony meteorites.

  3. Noble gases, nitrogen and cosmic ray exposure age of the Sulagiri chondrite

    Directory of Open Access Journals (Sweden)

    Ramakant R. Mahajan

    2017-01-01

    Full Text Available The Sulagiri meteorite fell in India on 12 September 2008, LL6 chondrite class is the largest among all the Indian meteorites. Isotopic compositions of noble gases (He, Ne, Ar, Kr and Xe and nitrogen in the Sulagiri meteorite and cosmic ray exposure history are discussed. Low cosmogenic (22Ne/21Nec ratio is consistent with irradiation in a large body. Cosmogenic noble gases indicate that Sulagiri has a 4π cosmic-ray exposure (CRE age of 27.9 ± 3.4 Ma and is a member of the peak of CRE age distribution of LL chondrites. Radiogenic 4He and 40Ar concentrations in Sulagiri yields the radiogenic ages as 2.29 and 4.56 Ga, indicating the loss of He from the meteorite. Xenon and krypton are mixture of Q and spallogenic components.

  4. Noble gases, nitrogen and cosmic ray exposure age of the Sulagiri chondrite

    Institute of Scientific and Technical Information of China (English)

    Ramakant R. Mahajan

    2017-01-01

    The Sulagiri meteorite fell in India on 12 September 2008, LL6 chondrite class is the largest among all the Indian meteorites. Isotopic compositions of noble gases (He, Ne, Ar, Kr and Xe) and nitrogen in the Sulagiri meteorite and cosmic ray exposure history are discussed. Low cosmogenic (22Ne/21Ne)c ratio is consistent with irradiation in a large body. Cosmogenic noble gases indicate that Sulagiri has a 4πcosmic-ray exposure (CRE) age of 27.9 ± 3.4 Ma and is a member of the peak of CRE age distribution of LL chondrites. Radiogenic 4He and 40Ar concentrations in Sulagiri yields the radiogenic ages as 2.29 and 4.56 Ga, indicating the loss of He from the meteorite. Xenon and krypton are mixture of Q and spallo-genic components.

  5. Cosmic ray exposure ages of features and events at the Apollo landing sites

    International Nuclear Information System (INIS)

    Arvidson, R.; Crozaz, G.; Drozd, R.J.; Hohenberg, C.M.; Morgan, C.J.

    1975-01-01

    Cosmic ray exposure ages of lunar samples have been used to date surface features related to impact cratering and downslope movement of material. Only when multiple samples related to a feature have the same rare gas exposure age, or when a single sample has the same 81 Kr-Kr and track exposure age can a feature be considered reliably dated. Because any single lunar sample is likely to have had a complex history, assignment of ages to features based upon only one determination by any method should be avoided. Based on the above criteria, there are only five well-dated lunar features: Cone Crater (Apollo 14) 26 m.y., North Ray Crater (Apollo 16) 50 m.y., South Ray Crater (Apollo 16) 2 m.y., the emplacement of the Station 6 boulders (Apollo 17) 22 m.y., and the emplacement of the Station 7 boulder (Apollo 17) 28 m.y. Other features are tentatively dated or have limits set on their ages: Bench Crater (Apollo 12) =50 m.y. (Auth.)

  6. Cosmic-ray exposure ages of six chondritic Almahata Sitta fragments

    Science.gov (United States)

    Riebe, M. E. I.; Welten, K. C.; Meier, M. M. M.; Wieler, R.; Barth, M. I. F.; Ward, D.; Laubenstein, M.; Bischoff, A.; Caffee, M. W.; Nishiizumi, K.; Busemann, H.

    2017-11-01

    The Almahata Sitta strewn field is dominated by ureilites, but contains a large fraction of chondritic fragments of various types. We analyzed stable isotopes of He, Ne, Ar, Kr, and Xe, and the cosmogenic radionuclides 10Be, 26Al, and 36Cl in six chondritic Almahata Sitta fragments (EL6 breccia, EL6, EL3-5, CB, LL4/5, R-like). The cosmic-ray exposure (CRE) ages of five of the six samples have an average of 19.2 ± 3.3 Ma, close to the average of 19.5 ± 2.5 Ma for four ureilites. The cosmogenic radionuclide concentrations in the chondrites indicate a preatmospheric size consistent with Almahata Sitta. This corroborates that Almahata Sitta chondrite samples were part of the same asteroid as the ureilites. However, MS-179 has a lower CRE age of 11.0 ± 1.4 Ma. Further analysis of short-lived radionuclides in fragment MS-179 showed that it fell around the same time, and from an object of similar size as Almahata Sitta, making it almost certain that MS-179 is an Almahata Sitta fragment. Instead, its low CRE age could be due to gas loss, chemical heterogeneity that may have led to an erroneous 21Ne production-rate, or, perhaps most likely, MS-179 could represent the true 4π exposure age of Almahata Sitta (or an upper limit thereof), while all other samples analyzed so far experienced exposure on the parent body of similar lengths. Finally, MS-179 had an extraordinarily high activity of neutron-capture 36Cl, 600 dpm kg-1, the highest activity observed in any meteorite to date, related to a high abundance of the Cl-bearing mineral lawrencite.

  7. Gardening process of lunar surface layer inferred from the galactic cosmic-ray exposure ages of lunar samples

    International Nuclear Information System (INIS)

    Iriyama, Jun; Honda, Masatake.

    1979-01-01

    From the cosmic-ray exposure age data, (time scale 10 7 - 10 8 years), of the lunar surface materials, we discuss the gardening process of the lunar surface layer caused by the meteoroid impact cratering. At steady state, it is calculated that, in the region within 10 - 50 m of the surface, a mixing rate of 10 -4 to 10 -5 mm/yr is necessary to match the exposure ages. Observed exposure ages of the lunar samples could be explained by the gardening effect calculated using a crater formation rate which is slightly modified from the current crater population data. (author)

  8. Aging simulation of the tailings from Stava fluorite extraction by exposure to gamma rays

    Directory of Open Access Journals (Sweden)

    Gianluca Bella

    Full Text Available Abstract Tailings storage facilities are disposal systems for storing the waste products of the mining industry consisting of a slurry mixture made of soil, rock and water that remain after the mineral values have been removed from the patent ore. Tailings dams are supposed to last forever, so after their deposition, tailings can experience aging processes with physical and chemical changes depending on the interactions between local conditions and source mineralogy. The consequences of these aging processes are increased interlocking of particles and oxidation processes, sometimes making previously safely held contaminants available and mobile. Among the long-term aging processes, the natural ionizing radiation (from radioactive isotopes of the soils, cosmic rays, and also ultraviolet rays from the sun can be considered, as proposed in the current research. Furthermore, in many countries, tailings are beginning to be re-used as backfill, landscaping material or feedstock for cement and concrete. So if any, the long-term physical and chemical modifications could affect the hydraulic and mechanical behaviour of tailings with relevant economic consequences. For these reasons, wet and dry silty samples of tailings spilled out after the failure of the Stava tailings dam (Trentino Alto Adige, Italy were exposed to gamma rays, as an accelerated aging technique to simulate the natural ionizing radiation, and then characterized. The modifications on physical and chemical properties were observed and, despite certain chemical stability, some physical changes were observed, particularly in terms of size particle distribution, inner porosity of the particles and specific surface.

  9. Aging simulation of the tailings from Stava fluorite extraction by exposure to gamma rays

    Energy Technology Data Exchange (ETDEWEB)

    Bella, Gianluca; Barbero, Monica; Barpi, Fabrizio, E-mail: gianluca.bella@polito.it, E-mail: monica.barbero@polito.it, E-mail: fabrizio.barpi@polito.it [Politecnico di Torino - DISEG (Italy); Lameiras, Fernando Soares, E-mail: fsl@cdtn.br [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil); Espósito, Terezinha de Jesus, E-mail: esposito@etg.ufmg.br [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Departamento de Transporte e Engenharia Geotécnica

    2017-10-15

    Tailings storage facilities are disposal systems for storing the waste products of the mining industry consisting of a slurry mixture made of soil, rock and water that remain after the mineral values have been removed from the patent ore. Tailings dams are supposed to last forever, so after their deposition, tailings can experience aging processes with physical and chemical changes depending on the interactions between local conditions and source mineralogy. The consequences of these aging processes are increased interlocking of particles and oxidation processes, sometimes making previously safely held contaminants available and mobile. Among the long-term aging processes, the natural ionizing radiation (from radioactive isotopes of the soils, cosmic rays, and also ultraviolet rays from the sun) can be considered, as proposed in the current research. Furthermore, in many countries, tailings are beginning to be re-used as backfill, landscaping material or feedstock for cement and concrete. So if any, the long-term physical and chemical modifications could affect the hydraulic and mechanical behaviour of tailings with relevant economic consequences. For these reasons, wet and dry silty samples of tailings spilled out after the failure of the Stava tailings dam (Trentino Alto Adige, Italy) were exposed to gamma rays, as an accelerated aging technique to simulate the natural ionizing radiation, and then characterized. The modifications on physical and chemical properties were observed and, despite certain chemical stability, some physical changes were observed, particularly in terms of size particle distribution, inner porosity of the particles and specific surface. (author)

  10. Cosmic-ray exposure ages of the ordinary chondrites and their significance for parent body stratigraphy

    Science.gov (United States)

    Crabb, J.; Schultz, L.

    1981-01-01

    Improved exposure ages are derived for 201 H, 203 L, and 38 LL chondrites in an effort to understand the characteristics of the chondrite parent body. The Ne-21 exposure ages were calculated from literature values taking into account shielding differences, a trapped component and radiogenic He. The exposure age distributions show clear peaks at 4.5 and 20 million years for the H chondrites, while the Ls and LLs appear more as a continuous series of intermediate peaks which may be modeled by at least six peaks between 1 and 35 million years in the case of L chondrites. The observations that every petrological type occurs in each large peak and contain solar wind gases suggest that the parent bodies have been fragmented and reassembled into a megabreccia. The H meteorites are proposed to represent the surface layer of a body with a substantial, active regolith as indicated by the relatively high abundances of solar gases. The L chondrites, on the other hand, are attributed to a parent body that was fragmented by collision about 500 million years ago.

  11. Santa Lucia (2008) (L6) Chondrite, a Recent Fall: Composition, Noble Gases, Nitrogen and Cosmic Ray Exposure Age

    Science.gov (United States)

    Mahajan, Ramakant R.; Varela, Maria Eugenia; Joron, Jean Louis

    2016-04-01

    The Santa Lucia (2008)—one the most recent Argentine meteorite fall, fell in San Juan province, Argentina, on 23 January 2008. Several masses (total ~6 kg) were recovered. Most are totally covered by fusion crust. The exposed interior is of light-grey colour. Chemical data [olivine (Fa24.4) and low-Ca pyroxene (En77.8 Fs20.7 Wo1.6)] indicate that Santa Luica (2008) is a member of the low iron L chondrite group, corresponding to the equilibrated petrologic type 6. The meteorite name was approved by the Nomenclature Committee (NomCom) of the Meteoritical Society (Meteoritic Bulletin, no. 97). We report about the chemical composition of the major mineral phases, its bulk trace element abundance, its noble gas and nitrogen data. The cosmic ray exposure age based on cosmogenic 3He, 21Ne, and 38Ar around 20 Ma is comparable to one peak of L chondrites. The radiogenic K-Ar age of 2.96 Ga, while the young U, Th-He are of 1.2 Ga indicates that Santa Lucia (2008) lost radiogenic 4He more recently. Low cosmogenic (22Ne/21Ne)c and absence of solar wind noble gases are consistent with irradiation in a large body. Heavy noble gases (Ar/Kr/Xe) indicated trapped gases similar to ordinary chondrites. Krypton and neon indicates irradiation in large body, implying large pre-atmospheric meteoroid.

  12. Evidence for differences in the thermal histories of Antarctic and non-Antarctic H chondrites with cosmic-ray exposure ages less than 20 Ma

    Science.gov (United States)

    Sears, Derek W. G.; Benoit, Paul; Batchelor, J. David

    1991-01-01

    Antarctic H chondrites show a different range of induced thermoluminescence properties compared with those of H chondrites that have fallen elsewhere in the world. Recent noble gas data of Schultz et al. (1991) show that this difference is displayed most dramatically by meteorites with cosmic-ray exposure ages less than 20 Ma, and they confirm that the differences cannot be attributed to weathering or to the presence of a great many fragments of an unusual Antarctic meteorite. Annealing experiments on an H5 chondrite, and other measurements on a variety of ordinary chondrites, have shown that induced TL properties are sensitive to the thermal histories of the meteorities. It is concluded that the events(s) that released the less than 20 Ma samples, which are predominantly those with exposure ages of 8 + or - 2 Ma, produced two groups with different thermal histories, one that came to earth several 100,000 years ago and that are currently only found in Antarctica, and one that is currently falling on the earth.

  13. Assessment of genetic risk of exposure resulted from X-ray examination of women of the reproductive age

    International Nuclear Information System (INIS)

    Strel'nikova, N.K.

    1989-01-01

    On the basis of the available data an evaluation of genetic radiation risk during roentgenologic examination of women of the reproductive age is presented. It is demonstrated that the degree of genetic risk depends on woman's age at the moment of the roentgenologic examination and the amount of the gonadal dose. Identification of the high-risk exposed populations has been substantiated

  14. Cosmic-ray exposure records and origins of meteorites

    International Nuclear Information System (INIS)

    Reedy, R.C.

    1985-01-01

    The cosmic-ray records of meteorites can be used to infer much about their origins and recent histories. Some meteorites had simple cosmic-ray exposure histories, while others had complex exposure histories with their cosmogenic products made both before and after a collision in space. The methods used to interpret meteorites' cosmic-ray records, especially identifying simple or complex exposure histories, often are inadequate. Besides spallogenic radionuclides and stable nuclides, measurements of products that have location-sensitive production rates, such as the tracks of heavy cosmic-ray nuclei or neutron-capture nuclides, are very useful in accurately determining a meteorite's history. Samples from different, known locations of a meteorite help in studying the cosmic-ray record. Such extensive sets of meteorite measurements, plus theoretical modeling of complex histories, will improve our ability to predict the production of cosmogenic nuclides in meteorites, to distinguish simple and complex exposure histories, and to better determine exposure ages

  15. Cosmic-ray exposure records and origins of meteorites

    International Nuclear Information System (INIS)

    Reedy, R.C.

    1985-01-01

    The cosmic-ray records of meteorites are used to infer much about their origins and recent histories. The methods used to interpret meteorites cosmic-ray records, especially identifying simple or complex exposure histories, often are inadequate. Spallogenic radionuclides, stable nuclides, and measurements of products that have location-sensitive production rates, such as the tracks of heavy cosmic-ray nuclei or neutron-capture nuclides, are very useful in accurately determining a meteorite's history. Samples from different, known locations of a meteorite help in studying the cosmic-ray record. Such extensive sets of meteorite measuremetns, plus theoretical modeling of complex histories, improves the ability to predict the production of cosmogenic nuclides in meteorites, to distinguish simple and complex exposure histories, and to better determine exposure ages

  16. A paediatric X-ray exposure chart

    Energy Technology Data Exchange (ETDEWEB)

    Knight, Stephen P, E-mail: stephen.knight@health.qld.gov.au [Department of Medical Imaging, Royal Children' s Hospital, Brisbane, Queensland (Australia)

    2014-09-15

    The aim of this review was to develop a radiographic optimisation strategy to make use of digital radiography (DR) and needle phosphor computerised radiography (CR) detectors, in order to lower radiation dose and improve image quality for paediatrics. This review was based on evidence-based practice, of which a component was a review of the relevant literature. The resulting exposure chart was developed with two distinct groups of exposure optimisation strategies – body exposures (for head, trunk, humerus, femur) and distal extremity exposures (elbow to finger, knee to toe). Exposure variables manipulated included kilovoltage peak (kVp), target detector exposure and milli-ampere-seconds (mAs), automatic exposure control (AEC), additional beam filtration, and use of antiscatter grid. Mean dose area product (DAP) reductions of up to 83% for anterior–posterior (AP)/posterior–anterior (PA) abdomen projections were recorded postoptimisation due to manipulation of multiple-exposure variables. For body exposures, the target EI and detector exposure, and thus the required mAs were typically 20% less postoptimisation. Image quality for some distal extremity exposures was improved by lowering kVp and increasing mAs around constant entrance skin dose. It is recommended that purchasing digital X-ray equipment with high detective quantum efficiency detectors, and then optimising the exposure chart for use with these detectors is of high importance for sites performing paediatric imaging. Multiple-exposure variables may need to be manipulated to achieve optimal outcomes.

  17. Determination of the spallogenic radionuclides 26Al and 53Mn in Antartic meteorites with respect to cosmic ray exposure and terrestrial ages

    International Nuclear Information System (INIS)

    Herpers, U.; Sarafin, R.

    1987-01-01

    The spallogenic radionuclides 26 Al (T=7.18x10 5 a) and 53 Mn (T=3.8x10 6 a) were determined in 11 ordinary chondrites and 7 achondrites from Antarctica by nondestructive coincidence counting techniques and radiochemical neutron activation analysis. The results are discussed with respect to exposure ages, terrestrial residence times and possible genetic relationships of the meteorites investigated. The high terrestrial ages of some specimens (up to 800 000 years) are of importance for the study of the ice flow in Antarctica. (author)

  18. X-ray exposures to dental patients

    International Nuclear Information System (INIS)

    McKlveen, J.W.

    1980-01-01

    An elastic mask worn by patients and a skeleton encased in plastic were instrumented with LiF thermoluminescent dosimeters to determine radiation exposures delivered from full-face diagnostic dental X-rays. Measurements were made using various panoramic radiographical and periapical machines. Locations of interest included skin surface, eyes, upper and lower teeth and thyroid. Exposures in the 100 mR range were common and a maximum of over 6000 mR was measured in the teeth region during a full-face examination with a periapical unit. In general, exposures received from periapical equipment were several times those obtained from panoramic devices. (author)

  19. Effects of differential postnatal exposure of the rat cerebellum to x-rays on spatial discrimination learning as a function of age and position preference

    International Nuclear Information System (INIS)

    Peters, K.B.

    1979-01-01

    The aim of the present research was to analyze the effects of postnatal exposure of the cerebellum to x-irradiation on the use of proprioceptive feedback in spatial learning. A total of 337 naive male Long-Evans hooded rats were assigned at birth to one of four treatments: 12-15x, 4-5x, 4-15x and control. Subjects assigned to the 12-15x treatment were exposed to 200R at 12 and 13 days of age, and to 150R at 15 days of age. The subjects exposed to the 4-5x schedule received 200R on days 4 and 5. The 4-15x subjects are exposed to 200R on days 4 and 5, and to 150R on days 7, 9, 11, 13, 15. Subjects from each treatment started spatial discrimination testing in a T-shaped water maze at 30 to 31, 60 to 63, or 180 to 185 days of age. A preference effect was evident in the control, 12-15x and 4-5x subjects, but not in the 4-15x subjects during acquisition testing. Those control, 12-15x and 4-5x subjects trained against their preference made more errors and required more trials to attain acquisition criterion than did those subjects trained toward their preference. The absence of a position preference in the 4-15x subjects is attributed to the absence of the mossy fiber channel of input to the Purkinje cells in this preparation. Deficits in spatial learning were evident in both the 12-15x and 4-15x subjects, the former differing significantly from control subjects and the latter from the 4-5x subjects in the number of trials needed to complete reversal testing and/or the number of errors made during this phase of the testing. It is the upper portion of the molecular layer, absent in the 12-15x and 4-15x preparations, which receives afferent input from the spinal cord

  20. Induction and repair of DNA double-strand breaks in hippocampal neurons of mice of different age after exposure to 60Co γ-rays in vivo and in vitro

    Science.gov (United States)

    Kozhina, R. A.; Chausov, V. N.; Kuzmina, E. A.; Boreyko, A. V.

    2018-04-01

    One of the central problems of modern radiobiology is the study of DNA damage induction and repair mechanisms in central nervous system cells, in particular, in hippocampal cells. The study of the regularities of molecular damage formation and repair in the hippocampus cells is of special interest, because these cells, unlike most cells of the central nervous system (CNS), keep proliferative activity, i.e. ability to neurogenesis. Age-related changes in hippocampus play an important role, which could lead to radiosensitivity changes in neurons to the ionizing radiation exposure. Regularities in DNA double-strand breaks (DSB) induction and repair in different aged mice hippocampal cells in vivo and in vitro under the action of γ-rays 60Co were studied with DNA comet-assay. The obtained dose dependences of DNA DSB induction are linear both in vivo and in vitro. It is established that in young animals' cells, the degree of DNA damage is higher than in older animals. It is shown that repair kinetics is basically different for exposure in vivo and in vitro.

  1. Age dependent systemic exposure to inhaled salbutamol

    DEFF Research Database (Denmark)

    Bønnelykke, Klaus; Jespersen, Jakob Jessing; Bisgaard, Hans

    2007-01-01

    AIMS: To determine the effect of age on systemic exposure to inhaled salbutamol in children. METHODS: Fifty-eight asthmatic children, aged 3-16 years, inhaled 400 microg of salbutamol from a pressurized metered dose inhaler with spacer. The 20 min serum profile was analyzed. RESULTS: Prescribing...

  2. Preparation of exposures charts for X-ray tubes

    International Nuclear Information System (INIS)

    Zoofan, B.

    1988-01-01

    An exposure chart is a fundamental graph which provides guidance of the exposure conditions in relation to the thickness for a given specimen. It must be prepared specially for the X-ray unit and the type of the film to be used. Although exposure charts are available for each particular X-ray tube from its manufacturer, individual radiographic laboratory should be able to prepare its own exposure charts in a precise manner. Here a typical procedure to prepare such a chart is provided in a practical way with some necessary recommendations

  3. Trends in x-ray photography and patient exposure dose

    International Nuclear Information System (INIS)

    Orito, Takeo; Sanada, Shigeru; Maekawa, Ryuichi; Koshida, Kichiro; Hiraki, Tatsunosuke

    1980-01-01

    The exposure doses of patients in X-ray photography are influenced by such technological factors as X-ray tube voltage, filter, sensitizing screen, film and grid. Survey by questionnnaire was made previously in 1973 on the above factors. The trends five years after were surveyed similarly, in connection with the exposure doses of patients. Questionnaires were sent to 200 radiation technicians, and 121 (60.5%) answered the survey in March, 1979. The results in the cases of simple X-ray photography and obstetric, infant and breast X-ray photographings are described. X-ray tube voltage is generally on the increase. In the sensitizing screens, exposure doses are fairly decreased due to the use of improved intensifying screen (LT-II). In the grid, the ratio 8 : 1 is used more than 5 : 1. In the usage of additional filters and in the distance of photography, improvements are desired. (J.P.N.)

  4. Exposure of nitrous oxide to X-rays

    International Nuclear Information System (INIS)

    Yanagida, H.

    1980-01-01

    A study was performed to determine how much NO and NO 2 is produced when nitrous oxide is exposed to X-radiation. Polyethylene bottles filled with either nitrous oxide alone or with nitrous oxide and 30% oxygen were placed 30 cm from the X-ray tube at a standard X-ray beam setting for chest fluoroscopy for 0 to 5 minutes. In the bottles filled with nitrous oxide alone, the production of NO was not affected by the duration of X-ray exposure, but the longer duration of X-ray exposure produced a larger amount of NO 2 . In the bottles filled with nitrous oxide and 30% oxygen, the longer duration of X-ray exposure produced larger amounts of both NO and NO 2 . These findings confirmed a previous investigation in which nitrous oxide was not inert under X-ray exposure. As the presence of oxygen plays an important role in the oxidation of nitrous oxide under X-ray exposure, this study suggests another potentially hazardous interaction that may occur secondary to the administration of an anaesthetic in the presence of X-irradiation as in pulmonary angiography, cardiac catheterisation, and fluoroscopic bronchoscopy or biopsy. (author)

  5. AIRGAMMA, External Gamma-Ray Exposure from Radioactive Cloud

    International Nuclear Information System (INIS)

    Hidaka, Akihide; Iijima, Tshinori

    1989-01-01

    1 - Description of program or function: AIRGAMMA calculates quickly the external exposure to gamma rays from a radioactive cloud. 2 - Method of solution: The external exposure is calculated by interpolating the normalized doses providing on the basis of the Gaussian plume model. 3 - Restrictions on the complexity of the problem: Memory requirement is 30 Kbytes

  6. Accelerated Aging Test for Plastic Scintillator Gamma Ray Detectors

    Energy Technology Data Exchange (ETDEWEB)

    Kouzes, Richard T. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2017-05-12

    Polyvinyl toluene (PVT) and polystyrene (PS), collectively referred to as “plastic scintillator,” are synthetic polymer materials used to detect gamma radiation, and are commonly used in instrumentation. Recent studies have revealed that plastic scintillator undergoes an environmentally related material degradation that adversely affects performance under certain conditions and histories. A significant decrease in gamma ray sensitivity has been seen in some detectors in systems as they age. The degradation of sensitivity of plastic scintillator over time is due to a variety of factors, and the term “aging” is used to encompass all factors. Some plastic scintillator samples show no aging effects (no significant change in sensitivity over more than 10 years), while others show severe aging (significant change in sensitivity in less than 5 years). Aging effects arise from weather (variations in heat and humidity), chemical exposure, mechanical stress, light exposure, and loss of volatile components. The damage produced by these various causes can be cumulative, causing observable damage to increase over time. Damage may be reversible up to some point, but becomes permanent under some conditions. It has been demonstrated that exposure of plastic scintillator in an environmental chamber to 30 days of high temperature and humidity (90% relative humidity and 55°C) followed by a single cycle to cold temperature (-30°C) will produce severe fogging in all PVT samples. This thermal cycle will be referred to as the “Accelerated Aging Test.” This document describes the procedure for performing this Accelerated Aging Test.

  7. Nitrous oxide pollution during x-ray exposure

    International Nuclear Information System (INIS)

    Yanagida, Hisashi; Nakajima, Michiaki.

    1980-01-01

    X-radiation has been shown to produce NO and NO 2 in the presence of nitrous oxide. The purpose of the present study was to confirm how much NO and NO 2 was produced when constant amount of nitrous oxide was exposed by constant X-radiation. Twenty polyethylene bottles (capacity 10 litres) were filled with nitrous oxide alone. Another 20 bottles were filled with nitrous oxide and 30% oxygen. Each bottle was placed at a distance of 30 cm from X-ray tube and they were directly in the line of the X-ray beam at a setting of 90 KV at 0.5 mA, a standard setting for chest fluoroscopy. The range of duration of X-ray exposure was from 0 (control), to 2, 3, and 5 minutes in 5 bottles each, respectively. A colorimetric recording method (Saltzman) and a chemiluminescent monitor were used for measurement of NO and NO 2 . In the bottles filled with nitrous oxide alone, the production of NO was not affected by the duration of X-ray exposure, but the longer duration of X-ray exposure produced a larger amount of NO 2 . In the bottles filled with nitrous oxide and 30% oxygen, the longer duration of X-ray exposure produced larger amounts of both NO and NO 2 . These findings confirmed a previous investigation in which nitrous oxide was not inert under X-ray exposure. As the presence of oxygen plays an important role in the oxidation of nitrous oxide under X-ray, this study suggests another potentially hazardous interaction that may occur secondary to the administration of anesthetic in the presence of X-irradiation such as pulmonary angiography, cardiac catheterization, and fluoroscopic bronchoscopy or biopsy under general anesthesia. (author)

  8. Exposure to rays and radiation hazards in connection with diagnostic X-ray procedures in children

    International Nuclear Information System (INIS)

    Protzer, K.

    1988-01-01

    In this study, figures and data about radiation exposures for diagnostic purposes are surveyed that were collected in connection with X-ray procedures in children. The data were sorted according to body regions and techniques required for their examination so as to permit separate analyses of procedures in the urogenital tract (intravenous urogramme, micturition cystourethrography), thorax (angiocardiogramme, thoractic aortogramme, examinations using cardiac catheters), gastrointestinal system (fluoroscopy and contrast-enhanced irrigoscopy), pelvis (survey radiography), skull (computed tomography) as well as in miscellaneous group of further origins. The second part of the report discusses the uncertainties surrounding the assessment of radiation hazards and indicated radiation doses. A formula is represented for the calculation of life-time reductions that can be applied to any type of cancer and embraces a number of factors like life expectancy at age X, the patient's age at the time of radiotherapy, the five-year-survival rate for the condition under investigation and the diseased organ. At the end of the study, some methods are pointed out that may be helpful in limiting radiation exposure. (KST) [de

  9. Age estimation of burbot using pectoral fin rays, brachiostegal rays, and otoliths

    Science.gov (United States)

    Klein, Zachary B.; Terrazas, Marc M.; Quist, Michael C.

    2014-01-01

    Throughout much of its native distribution, burbot (Lota lota) is a species of conservation concern. Understanding dynamic rate functions is critical for the effective management of sensitive burbot populations, which necessitates accurate and precise age estimates. Managing sensitive burbot populations requires an accurate and precise non-lethal alternative. In an effort to identify a non-lethal ageing structure, we compared the precision of age estimates obtained from otoliths, pectoral fin rays, dorsal fin rays and branchiostegal rays from 208 burbot collected from the Green River drainage, Wyoming. Additionally, we compared the accuracy of age estimates from pectoral fin rays, dorsal fin rays and branchiostegal rays to those of otoliths. Dorsal fin rays were immediately deemed a poor ageing structure and removed from further analysis. Age-bias plots of consensus ages derived from branchiostegal rays and pectoral fin rays were appreciably different from those obtained from otoliths. Exact agreement between readers and reader confidence was highest for otoliths and lowest for branchiostegal rays. Age-bias plots indicated that age estimates obtained from branchiostegal rays and pectoral fin rays were substantially different from age estimates obtained from otoliths. Our results indicate that otoliths provide the most precise age estimates for burbot.

  10. X-ray exposure from colour TV sets

    International Nuclear Information System (INIS)

    Nambi, K.S.V.; Viswanathan, P.S.

    1988-01-01

    A survey has been made of the X-ray exposures from colour television sets of eight different brands manufactured in India and one of foreign make. The high sensitivity of natural CaF 2 TL phosphor to low energy photons has been taken advantage of, in measuring the extremely low levels of the X-ray emis sion from the TV sets. The measured exposures range from 8 to 27 μRh -1 and are well below the radiation safety limit internationally adopted. (author). 4 tabs

  11. Excessive exposures of diagnostic X-ray workers in India

    International Nuclear Information System (INIS)

    Ambiger, T.Y.; Shenoy, K.S.; Patel, P.H.

    1980-01-01

    The excessive exposures (i.e. exceeding 400 mrems per fortnight) of diagnostic X-ray workers revealed under the countrywide personnel monitoring programme in India have been analysed. The analysis covers the data collected over a period of ten years during 1965-1974. The radiation workers in medical X-ray diagnostic group receiving an excess dose are found to be less than 1%. Each case of the excess dose is throughly investigated and nongenuine cases are separated and causes for genuine excessive exposures are traced. The causes and the corrective measures are enumerated. (M.G.B.)

  12. Observation of X-ray occupational exposure on psychological function of medical workers

    International Nuclear Information System (INIS)

    Gong Zhaolong; Li Xiuqin

    1988-01-01

    The present research is an attempt to study the psychological effects of long-term exposure to low-level X-ray on man. The subjects included 50 exposed people and 50 control. The battery of psychological tests consists of 10 subtests mainly involving memory and coordination ability. The results indicate that there are no statistical differences in all subtests between exposure and control group, but exposure group appears to be a little lower on most subtests about memory. With age, decline of psychological function is observed in all subtests in both groups. The subjects are further divided into three subgroups according to the number of X-ray exposed years. No statistical differences are found in all subgroups between exposure and control. Factor analysis has been made and two factors are obtained. factor 1 is mainly about speed of coordination, factor 2 is mainly about memory and attention. No statistical differences in factor scores are observed in all subgroups between exposure and control. Yet decline is found in factor 1 and factor 2 in both exposure and control groups with age. The results show that there is no significant effect of current dose level of X-ray exposure on human psychological function

  13. Cosmic ray exposure in aircraft and space flight

    International Nuclear Information System (INIS)

    Kosako, Toshiso; Sugiura, Nobuyuki; Iimoto, Takeshi

    2000-01-01

    The exposure from cosmic ray radiation to the workers and public is a new aspect of exposure that was cased by the development of science and technology. ICRP Publication 60 says: 'to provide some practical guidance, the Commission recommends that there should be a requirement to include exposure to natural sources as part of occupational exposure only in the following cases: radon..., some natural radionuclides..., operation of jet air craft, space flight'. For this situation what kind of radiation protection concept is applicable? And what kind of radiation guideline and procedure are possible to propose? Here, we would like to review the past activities on this issue and to summarize the concepts in ICRP concerning to these exposure. Then the recommended radiation protection system will be proposed as one trial to this solution. In the paper the characters of cosmic ray were firstly reviewed. Cosmic rays are consisted by solar one and galactic one. Both of them have high energy and this will cause the difficulty of dosimetry because of lacking of physical and biological data. Next discussion point is a classification of exposure. For this, several classifications were done: jet airplane flight, supersonic airplane flight and space flight. Other classification is aircrew (occupational exposure), passengers (public exposure), frequent flyers (gray zone), space astronauts (special mission), and pregnant women. Considering the real level of radiation the practical radiation control is proposed including the cosmic radiation exposure prediction method by computer codes. The discussion of space astronauts is a little different for the highness of radiation doses. The dose levels will be obtained through the discussion of lifetime risk balancing their mission importance. (author)

  14. On the age distribution of galactic cosmic rays

    International Nuclear Information System (INIS)

    Owens, A.J.

    1975-01-01

    I consider the general solution for the distribution of ages for primary cosmic rays for a class of steady-state, bounded models of cosmic-ray diffusion in the galaxy. Both one dimensional and three-dimensional models are considered, with point sources and distributed sources. In all models, the age distribution is approximately exponential for ages longer than the average age, although for shorter ages the distribution depends on the details of the model. (orig.) [de

  15. Accidental over-exposure from dental X-ray equipment

    Energy Technology Data Exchange (ETDEWEB)

    Phillips, B G [National Radiological Protection Board, Harwell (UK)

    1976-07-01

    A description is given of an unusual dental X-ray procedure which resulted in accidental over-exposure both to the dentist and to several of his patients when a short-circuit was present in newly-installed equipment. The short-circuit by-passed the exposure control and energized the tube for certain orientations of the X-ray tube. The dentist left the patients, who wore protective aprons, to initiate the exposure themselves, using the control button. Although the warning lights were on, the dentist was not present in the room during the exposure, and the over-exposures were only detected when the developed X-ray films were found to be completely blackened. A reconstruction of the procedure enabled estimates to be made of the dose equivalents to the dentist's body and to the skin of the head, the eyes and the gonads of the patients. The dentist had overlooked several of basic principles recommended in the Code of Practice for the Protection of Persons against Ionizing Radiations from Medical and Dental Use (1972). It is pointed out that incidents involving failure of dental equipment (usually the timer mechanism) are not infrequent.

  16. Solar exposure of sunglasses: aging test display

    Science.gov (United States)

    Gomes, L. M.; Masili, M.; Momesso, G. A.; Silva, F. M.; Ventura, L.

    2018-02-01

    In previous studies conducted in our lab, we have been investigating the aging effects on sunglasses. Some preliminary results have been indicating changes on the UV protection on the lenses. Therefore, besides irradiating the samples with a proper sun simulator, we have also been concerned on exposing the sunglasses to natural sun for further investigation and comparisons. Thus, this project aims expose the lenses for 24 months using an automatic solar exposition station, which consists of a series of 5 panels, housing 60 lenses arranged in the vertical position to the ground, which will be irradiated by the sun from sunrise until sunset. A box structure moves along a rail, driven by a motor and then the lenses are exposed. Humidity, rain, temperature, dust and UV index sensors, as well as a video camera are part of the system. The exposure time and UV index will be recorded and automatic opening or closing the box system may also be controlled by a PC using a webserver. The system was tested in working conditions, i.e. exposed to the weather and being automatically controlled, for five months to certifying that the samples could be exposed without being damaged. The next step of the research is to start the exposition cycles and to measure the expected transmittance variations after each cycle.

  17. Calculation of gamma ray exposure rates from uranium ore bodies

    International Nuclear Information System (INIS)

    Thomson, J.E.; Wilson, O.J.

    1980-02-01

    The planning of operations associated with uranium mines often requires that estimates be made of the exposure rates from various ore bodies. A straight-forward method of calculating the exposure rate from an arbitrarily shaped body is presented. Parameters for the calculation are evaluated under the assumption of secular equilibrium of uranium with its daughters and that the uranium is uniformly distributed throughout an average soil mixture. The spectral distribution of the emitted gamma rays and the effect of air attenuation are discussed. Worked examples are given of typical situations encountered in uranium mines

  18. Constancy of radiation output during diagnostic X-ray exposures

    International Nuclear Information System (INIS)

    Ardran, G.M.; Crooks, H.E.; Birch, R.

    1978-01-01

    Variation in X-ray output and quality during a diagnostic exposure can be undesirable and may result in unnecessary dose to the patient. When significant build-up or decay periods are present errors will arise if factors obtained under steady-state conditions are employed to estimate the exposure. These parameters must be taken into account when calibrating X-ray generators. A variable speed spinning film device and a spectrometry system have been used to measure the variations under fluoroscopic and radiographic conditions for a number of generators. Variations in output due to filament heating, voltage supply and rectification, cable capacity and target pitting have been demonstrated. At low fluoroscopic currents, large surges and long decays have been observed; the significance of these effects is considered. (author)

  19. Radiation exposure in X-ray studies of the hips

    Energy Technology Data Exchange (ETDEWEB)

    Kainberger, F [Krankenhaus der Barmherzigen Brueder, Salzburg (Austria). Roentgeninstitut

    1979-12-01

    The genetic exposure of the small child is above all a consequence of the rapid increase in X-ray studies, a problem which has not yet been settled. Through phantom measurements it can be shown, that dose reduction is of considerable practical significance if appropriate lead shielding is employed. The radiation dose can be significantly reduced, provided that the shielding material is of an appropriate lead equivalent. The form of the pelvic shield which is used is also of crucial importance.

  20. Prenatal x-ray exposure and childhood cancer in twins

    International Nuclear Information System (INIS)

    Harvey, E.B.; Boice, J.D. Jr.; Honeyman, M.; Flannery, J.T.

    1985-01-01

    A case-control study was conducted to investigate the relation between prenatal exposure to x-rays and childhood cancer, including leukemia, in over 32,000 twins born in Connecticut from 1930 to 1969. Twins as opposed to single births were chosen for study to reduce the likelihood of medical selection bias, since twins were often exposed to x-rays to diagnose the twin pregnancy or to determine fetal positioning before delivery and not because of medical conditions that may conceivably pre-dispose to cancer. Each of 31 incident cases of cancer, identified by linking the Connecticut twin and tumor registries, was matched with four twin controls according to sex, year of birth, and race. Records of hospitals, radiologists, and private physicians were searched for histories of x-ray exposure and other potentially important risk factors. Documented prenatal x-ray exposures were found for 39 per cent of the cases (12 of 31) and for 26 per cent of the controls (28 of 109). No other pregnancy, delivery, or maternal conditions were associated with cancer risk except low birth weight: 38 per cent of the cases as compared with 25 per cent of the controls weighed under 2.27 kg at birth. When birth weight was adjusted for, twins in whom leukemia or other childhood cancer developed were twice as likely to have been exposed to x-rays in utero as twins who were free of disease (relative risk, 2.4; 95 per cent confidence interval, 1.0 to 5.9). The results, though based on small numbers, provide further evidence that low-dose prenatal irradiation may increase the risk of childhood cancer

  1. X-ray survey of the Pleiades: dependence of X-ray luminosity on stellar age

    International Nuclear Information System (INIS)

    Micela, G.; Sciortino, S.; Serio, S.; Vaiana, G.S.; Golub, L.; Harnden, F.R.; Rosner, R.

    1984-01-01

    The study of X-ray emission of stellar clusters, allows to decouple the influence of some individual stellar parameters, as initial conditions, composition and age, on the stellar X-ray function. The authors report preliminary results from an Einstein X-ray survey of the Pleiades. (Auth.)

  2. Acute behavioural dysfunctions following exposure to γ-rays

    International Nuclear Information System (INIS)

    Kumar, Mayank; Haridas, Seenu; Manda, Kailash

    2014-01-01

    Exposure to ionizing radiations (IR) has been reported to have many ill effects. These are manifested immediately after exposure and may persist or develop long after the incident. The severity and manifestation is dependent on the absorbed dose and type of the IR. These have been reported extensively in human subjects; especially among the victims of the accidental exposure and radiotherapy patients. Additionally, there have been a plethora of studies in animal models which support these findings, and are being used to test radio-mitigative or radio-protective strategies. The vulnerability of neuronal tissue to IR is well known, however the acute dose-dependent behavioural consequences have yet to be understood. Thus, our laboratory has been trying to decipher the dose-dependent behavioural dysfunctions which have occurred 24-72 hours post IR exposure and possible radio-protective strategies. We are utilizing mouse models of studying the behavioural processes, in a test battery conceptualized to study the affective and cognitive skills as well as motor skills of the animals. Additionally, we have observed cellular damage to different areas of the brain and subsequent correlations to behavioural dysfunctions. This has being carried out by using single cell gel electrophoresis (SCGE) and Diffusion Tensor Imaging (DTI). The findings show that after exposure to sub-lethal γ-rays, there are significant changes that occur in all the behavioural parameters. The most sensitive area has been found to be the Hippocampus as visualized by DTI and the SCGE. Consequently, short term and long term memory functions have been shown to be disrupted within 24-72 hours of exposure. Acute dysfunctions of affective functions have also been demonstrated to materialise within 24 hours post exposure. Unexpectedly, the behavioural dysfunctions were seen to be dose independent. Thus, this study provides a foundation to help decipher the acute behavioural manifestations of IR exposure

  3. Cost Benefit Optimization of the Israeli Medical Diagnostic X-Ray Exposure

    International Nuclear Information System (INIS)

    Ben-Shlomo, A.; Shlesinger, T.; Shani, G.; Kushilevsky, A.

    1999-01-01

    Diagnostic and therapeutic radiology is playing a major role in modern medicine. A preliminary survey was carried out during 1997 on 3 major Israeli hospitals in order to assess the extent of exposure of the population to medical x-rays (1). The survey has found that the annual collective dose of the Israeli population to x-ray medical imaging procedures (excluding radio-therapy) is about 7,500 Man-Sv. The results of the survey were analyzed in order to. 1. Carry out a cost-benefit optimization procedure related to the means that should be used to reduce the exposure of the Israeli patients under x-ray procedures. 2. Establish a set of practical recommendations to reduce the x-ray radiation exposure of patients and to increase the image quality. . Establish a number of basic rules to be utilized by health policy makers in Israel. Based on the ICRP-60 linear model risk assessments (2), the extent of the annual risk arising A.om the 7,500 Man-Sv medical x-ray collective dose in Israel has been found to be the potential addition of 567 cancer cases per year, 244 of which to be fatal, and a potential additional birth of 3-4 children with severe genetic damage per year. This assessment take into account the differential risk and the collective dose according to the age distribution in the Israeli exposed population, and excludes patients with chronic diseases

  4. X-Ray Exam: Bone Age Study (For Parents)

    Science.gov (United States)

    ... Fitness Diseases & Conditions Infections Drugs & Alcohol School & Jobs Sports Expert Answers (Q&A) Staying Safe Videos for ... large numbers of other kids of the same gender and age. The bone age is measured ... on the X-ray. A difference between a child's bone age and his or ...

  5. Computer program for diagnostic X-ray exposure conversion

    International Nuclear Information System (INIS)

    Lewis, S.L.

    1984-01-01

    Presented is a computer program designed to convert any given set of diagnostic X-ray exposure factors sequentially into another, yielding either an equivalent photographic density or one increased or decreased by a specifiable proportion. In addition to containing the wherewithal with which to manipulate a set of exposure factors, the facility to print hard (paper) copy is included enabling the results to be pasted into a notebook and used at any time. This program was originally written as an investigative exercise into examining the potential use of computers for practical radiographic purposes as conventionally encountered. At the same time, its possible use as an educational tool was borne in mind. To these ends, the current version of this program may be used as a means whereby exposure factors used in a diagnostic department may be altered to suit a particular requirement or may be used in the school as a mathematical model to describe the behaviour of exposure factors under manipulation without patient exposure. (author)

  6. Implementation of a primary standard for x-ray exposure

    International Nuclear Information System (INIS)

    Peixoto, Jose Guilherme Pereira

    1991-04-01

    In the scientific program of the National Laboratory for Ionizing Radiation Metrology of the Instituto de Radioprotecao e Dosimetria, which belongs to the Comissao Nacional de Energia Nuclear, a free-air ionization chamber should be established as an exposure primary standard for X-ray s of 10OKV to 250kV of potential range. Preliminary results showed that the available free-air ionization chamber was suitable to be used. The absolute measurement of the radiation quantity exposure, is performed with a free-air ionization chamber. Its geometrical volume, which allows the determination of the air mass, is defined by the effective aperture area and by the length of the region where an electrical field is applied. Most of the ions produced in such volume are collected as an ionization current. Since the collecting rod is small, and positioned far away from the X-ray beam, only a negligible fraction of ionization (0,01 %) is lost due to interactions with it. Parameters related to the measurement of the quantity exposure were evaluated, such as: air absorption, scattering inside the ionization chamber, saturation , beam homogeneity, influence Of beam size and influences of temperature, humidity and atmospheric pressure.Preliminary determination of correction factors has showed good results with 99.9% of repeatability and has demonstrated the reliability of the checked chamber as a standard instrument. (author)

  7. Radiation exposure with the NOMAD portable X-ray system.

    Science.gov (United States)

    Goren, A D; Bonvento, M; Biernacki, J; Colosi, D C

    2008-02-01

    A new hand-held battery-operated portable X-ray system was tested for possible leakage radiation through the existing heavy metal compounds surrounding the X-ray tube, backscatter radiation through the lead-filled acrylic shield attached at the end of the exit tube and patient exposure. Dose measurements were conducted using a DXTRR phantom and a water phantom. All measurements were recorded using calibrated thermoluminescent dosimetry (TLD), calibrated Unfors Model 583L dosemeter, and a calibrated Radcal MDH model 1015 dosemeter. The settings for all exposure were 60 kVp, 2.3 mA and 0.25 s using Kodak Insight (Class F) film. All backscatter measurements, in front of the shield, behind the shield, at the finger of the operator, the operator's chest, eyes and gonads were significantly below the maximum permissible radiation leakage as per the United States Food and Drug Administration regulations (100 mR h(-1)). Our measurements indicate that the exposure would be well within the occupational maximum permissible dose for an occupationally exposed person. Film dose was consistent with the manufacturer's recommendations. As a result of our measurements, the State of New York Bureau of Environmental Radiation Protection granted us a variance to use the NOMAD on a case-by-case basis. Our data have shown that the NOMAD presents risks that are no greater than with standard dental radiographic units to the patient or operator and the measured doses are well below recommended levels.

  8. ABCC-JNIH adult health study Hiroshima and Nagasaki 1961 exposure to medical x-ray. Preliminary survey

    Energy Technology Data Exchange (ETDEWEB)

    Ishimaru, Toranosuke; Russell, W J

    1962-05-16

    A survey was conducted for three months among subjects seen in the medical clinics of ABCC, Hiroshima and Nagasaki, to determine the extent of medical x-ray received in ABCC and other hospitals and clinics. Emphasis was chiefly methodological to prepare for later studies designed to evaluate the contribution of medical x-ray to total radiation dose received by survivors of the atomic bombings and controls. The frequency, the institution in which the subject received x-ray, as well as the types of exposure were the prime considerations in the survey. The data were analyzed for each city by sex, age, and exposure status. 2 references, 5 figures, 11 tables.

  9. Accidental exposure with X-ray diffraction equipment

    International Nuclear Information System (INIS)

    Montanez, O.; Blanco, D.

    1991-01-01

    The shutter on one of the windows of an X-ray diffraction apparatus was accidentally left open, exposing the worker to the radiation. The worker was wearing a dosimeter film, which was processed immediately to evaluate the potential risk. It was determined that the exposure rate was 350 Roentgen/minute on the skin surface, with corrections being made for the worker's thin clothing. It was concluded that in spite of the worker receiving a relative high dose, it did not reach the threshold value for producing deterministic effects such as cataracts, erythema, and skin damage

  10. Radiation exposure in X-ray examinations of the pelvis

    International Nuclear Information System (INIS)

    Kainberger, F.

    1977-01-01

    The article reports on radiation exposure during X-ray treatment of the pelvis of children. Special attention is paid to genetical radiation exposure. Generally a dose of 100 mR is assumed to be taken up if no adequate shielding is provided. In order to be able to judge the value of a shielding with suitable lead-equivalent values, measurements were carried out on a phantom. These measurements showed that the dosage can be reduced by at least a factor 100 by using a lead shielding. When doing this, the lead equivalent value must be 1 mm. The form of gonad protection also has great importance for the shielding efficiency. (orig.) [de

  11. Cytogenetic studies with laser or X-ray exposures

    International Nuclear Information System (INIS)

    Bozduganov, A.; Genkov, P.

    1975-01-01

    Account is given of studies involving a total of 21 peripheral blood cultures given the following treatments: exposure to 20 0.13-joule pulses from an optic quantum generator (ruby), 9; exposure to 1000 R X-rays, 9; and unexposed controls, 3. Exposures were carried out on three cultures from each experimental series at each of three time intervals, namely 24 h, 48 h, and 72 h after initiation of cultures. On any day, 40 well-spread metaphases were examined. High quality metaphases were photographed and karyotyped in conformity to the Chicago Conference criteria. In the laser experiment, chromosome aberrations were observed in 65% of methaphases analyzed vs. 5.3% in controls. Anomalies encountered included aneuploidy, with hypoploid metaphases predominating, polyploidy (triploidy, tetraploidy, and partial endoreduplication), and structural alterations. The following structural chromosome rearrangements are found: acentric fragments, mostly pairs, occasionally single, including minute chromosomes; dicentric and tricentric chromosomes; interstitial deletions; and chromosome translocations. Most varied and abundant chromosome aberrations were seen in 72-h irradiated cultures. The data presented offer a new opportunity for assessing genetic lesions after laser exposure and may help to determine threshold doses. (author)

  12. Hospital and clinic survey estimates of medical x-ray exposures in Hiroshima and Nagasaki, (1)

    International Nuclear Information System (INIS)

    Sawada, Shozo; Land, C.E.; Otake, Masanori; Russell, W.J.; Takeshita, Kenji.

    1980-11-01

    All large hospitals and 40% of the small hospitals and clinics in Hiroshima and Nagasaki cities were surveyed for the X-ray examinations they performed during a 2-week period in 1974. The frequency and type of X-ray examinations received by members of the RERF Adult Health Study (AHS) and the RERF Life Span Study (LSS) extended, excluding AHS (Non-AHS), were compared with the general population in each city. Radiologic exposures of patients at hospitals and clinics were most frequent among the general populations. The number of patients, examinations, and exposures per caput per year in each population were estimated. Since the age distribution differed among the three populations, comparisons were made only after correcting for age. On a per caput per year basis exposure frequency was relatively high in the AHS and low in the general populations, a reflection of the greater number of patients in the AHS than in the general populations. Non-AHS males in Nagasaki had a higher X-ray examination rate than did the AHS subjects. The others in the Non-AHS did not differ appreciably from the general populations. There was no difference among these groups according to body sites examined. (author)

  13. Digital Exhibitionism The Age of Exposure

    Directory of Open Access Journals (Sweden)

    Ana María Munar

    2010-09-01

    Full Text Available Web 2.0 has expanded the possibilities of digital creative production by individu-als and enabled the digitalisation of private life experiences. This study analyses how social media contributes to the making of personal biographies and discusses the shift towards a culture of digital exposure. This study uses netnography and a constructive approach to examine online communities and social networks. The findings illustrate that these new technological platforms are mediating in the con-struction of late modern biographies, which are expanding the complexity of to-day’s socio-technical systems. The paper discusses the power of these technolo-gies as agents of socio-cultural change and suggests that, besides providing indi-vidual realisation and mediated pleasure, these technologies encourage exhibitio-nistic and voyeuristic behaviour, elude reflexivity, and display authoritative ten-dencies and new possibilities for social control.

  14. Risk assessment of medical exposure in X-ray examinations of children

    Directory of Open Access Journals (Sweden)

    I. G. Shatsky

    2017-01-01

    Full Text Available The use of the effective dose (the concept of which was developed for radiation protection of workers and public and the nominal risk coefficients, averaged by sex and age, to assess the radiation risks of medical exposure has some significant limitations. Age and sex distribution of the staff and the entire population may be quite different from the sex and age distribution of patients undergoing medical exposure. Moreover, the structure of the age and sex of patients may be different for various medical examinations. There are simplified methods for evaluating individual risk for patients undergoing medical exposure. The methods are based on the effective dose evaluation and those take in to account age and gender. A more accurate assessment of lifetime risk of delayed stochastic effects for health of the patient is achieved by using the organ doses and the age and gender risk factors. The aim of this work was evaluation of the lifetime risk of long-term stochastic health effects for different gender and age groups of children undergoing various radiographic investigations by using organ doses and the age and gender risk factors, and subsequent classification in accordance with generally accepted international risk scale. Data from surveys of33 X-ray units in 29 specialized pediatric health care organizations in Russia were used in the work. Organ doses and patient’s effective doses were calculated on the basis of the defined for each x-ray machine typical modes for the 12 radiographic procedures (X-ray exam of the skull, chest, cervical spine, thoracic spine, lumbar spine–all in two projections – of the abdomen and pelvis – both in one projectionusing a computer program PCXMC., Radiation risks for selected studies were estimated using the obtained organ doses and the age and gender risk factors calculated for the Russian population. The radiation risks were classified according to the international scale of the risks. It was found

  15. Contribution of cosmic rays to radiation exposure of the population

    International Nuclear Information System (INIS)

    Sztanyik, L.B.; Nikl, I.

    1982-01-01

    To evaluate the exposure of the Hungarian population to cosmic rays, the absorbed dose rate in air of cosmic radiation was directly measured by high pressure ionization chamber at ground level on the surface of different bodies of water and at various altitudes on the board of an aircraft. From the dose rates measured this way, the outdoor dose equivalent rate from the ionizing components of cosmic radiation to people living at sea level would be 300-325 μSv per year. Taking into account the altitude distribution of the population, the average weighted dose equivalent is about 320 μSv per year. At Kekestetoe, the highest peak of the Matra Mountains, (the highest altitude in Hungary), the annual dose equivalent is about 50 per cent higher than on the Great Hungarian Plain. (author)

  16. Radiation exposure to chest X-rays in the neonatal nursery

    International Nuclear Information System (INIS)

    Takeuchi, Toshio; Itabashi, Kazuo; Kawaguchi, Shigeru; Suzuka, Takahisa; Okuyama, Kazuo

    1989-01-01

    To measure how much very low birth-weight infants are exposed to chest X-rays during nursery, skin doses were calculated using phantoms under the same condition as that used in chest X-rays. Skin doses obtained were multiplied by the number of X-rays performed in 86 very low birth-weight infants (mean birth weight+-SD, 1163.0+-232.8 g; mean gestational age+-SD, 29.3+-3.0 week). Exposure doses per film ranged from 4.9 to 14.4 mR, with a mean dose of 6.1+-2.0 mR. Exposure doses per neonate ranged from 6.3 to 794.3 mR, with a mean dose of 170.4+-151.5 mR. The number of films per neonate ranged from one to 107, with a mean of 28.0+-24.9. Eighty-seven percent of X-rays were performed when the body weight was 1,500 g or less. Fourteen patients received 300 mR or more that may be the potential dose of radiation effects. (Namekawa, K)

  17. Econometric model for age- and population-dependent radiation exposures

    International Nuclear Information System (INIS)

    Sandquist, G.M.; Slaughter, D.M.; Rogers, V.C.

    1991-01-01

    The economic impact associated with ionizing radiation exposures in a given human population depends on numerous factors including the individual's mean economic status as a function age, the age distribution of the population, the future life expectancy at each age, and the latency period for the occurrence of radiation-induced health effects. A simple mathematical model has been developed that provides an analytical methodology for estimating the societal econometrics associated with radiation effects are to be assessed and compared for economic evaluation

  18. Differences of X-ray exposure between X-ray diagnostics with a conventional X-ray screen-system and with an image-intensifier-television-unit

    International Nuclear Information System (INIS)

    Loehr, H.; Vogel, H.; Reinhart, J.; Jantzen, R.

    1977-01-01

    During X-ray diagnostics of patients in the II. Medizinische Poliklinik the X-ray exposure was determined. It corresponded to the data described in literature. Two groups were compared: 518 patients examined with a conventional X-ray screen-system and 642 patients examined with an image-intensifier-television-system. The results demonstrated that with exception of thoracical X-ray examination the replacing of the old system by the television system brought a remarkable increase of the X-ray exposure. The doses depended of the patients constitution to a high degree. (orig.) [de

  19. In Situ Radiometric and Exposure Age Dating of the Martian Surface

    Science.gov (United States)

    Farley, K. A.; Malespin, C.; Mahaffy, P.; Grotzinger, J. P.; Vasconcelos, P. M.; Milliken, R. E.; Malin, M.; Edgett, K. S.; Pavlov, A. A.; Hurowitz, J. A.; hide

    2014-01-01

    We determined radiogenic and cosmogenic noble gases in a mudstone on the floor of Gale Crater. A K-Ar age of 4.21 +/- 0.35 billion years represents a mixture of detrital and authigenic components and confirms the expected antiquity of rocks comprising the crater rim. Cosmic-ray-produced 3He, 21Ne, and 36Ar yield concordant surface exposure ages of 78 T 30 million years. Surface exposure occurred mainly in the present geomorphic setting rather than during primary erosion and transport. Our observations are consistent with mudstone deposition shortly after the Gale impact or possibly in a later event of rapid erosion and deposition. The mudstone remained buried until recent exposure by wind-driven scarp retreat. Sedimentary rocks exposed by this mechanism may thus offer the best potential for organic biomarker preservation against destruction by cosmic radiation.

  20. Childhood cancer after prenatal exposure to diagnostic X-ray examinations in Britain

    International Nuclear Information System (INIS)

    Mole, R.H.

    1990-01-01

    Detailed data were provided by the Oxford Survey of Childhood Cancer OSCC on deaths from childhood cancer in Britain after irradiation of the fetus during diagnostic radiology of the mother. In each age group at death, 0-5, 6-9 and 10-15 years, excess cancer deaths decreased suddenly for births in and after 1958. A major factor was concerted action initiated in 1956 to reduce radiation exposure of fetal gonads for fear of genetic hazards. Dose reduction was achieved during 1957 and early 1958 by reducing the rising rate of obstetric radiography and by virtually abandoning pelvimetry as that had been understood. In the 1970s the rate of X-raying increased again and so did cancer risk but not significantly. Direct evidence that diagnostic X-rays can cause childhood cancer is the similar excess rate per X-ray in twins and singleton births when X-raying rate is 5-6 times higher in twins. (author)

  1. Cognitive decline, mortality, and organophosphorus exposure in aging Mexican Americans.

    Science.gov (United States)

    Paul, Kimberly C; Ling, Chenxiao; Lee, Anne; To, Tu My; Cockburn, Myles; Haan, Mary; Ritz, Beate

    2018-01-01

    Cognitive impairment is a major health concern among older Mexican Americans, associated with significant morbidity and mortality, and may be influenced by environmental exposures. To investigate whether agricultural based ambient organophosphorus (OP) exposure influences 1) the rate of cognitive decline and mortality and 2) whether these associations are mediated through metabolic or inflammatory biomarkers. In a subset of older Mexican Americans from the Sacramento Area Latino Study on Aging (n = 430), who completed modified mini-mental state exams (3MSE) up to 7 times (1998-2007), we examined the relationship between estimated ambient OP exposures and cognitive decline (linear repeated measures model) and time to dementia or being cognitively impaired but not demented (CIND) and time to mortality (cox proportional hazards model). We then explored metabolic and inflammatory biomarkers as potential mediators of these relationships (additive hazards mediation). OP exposures at residential addresses were estimated with a geographic information system (GIS) based exposure assessment tool. Participants with high OP exposure in the five years prior to baseline experienced faster cognitive decline (β = 0.038, p = 0.02) and higher mortality over follow-up (HR = 1.91, 95% CI = 1.12, 3.26). The direct effect of OP exposure was estimated at 241 (95% CI = 27-455) additional deaths per 100,000 person-years, and the proportion mediated through the metabolic hormone adiponectin was estimated to be 4% 1.5-19.2). No other biomarkers were associated with OP exposure. Our study provides support for the involvement of OP pesticides in cognitive decline and mortality among older Mexican Americans, possibly through biologic pathways involving adiponectin. Copyright © 2017 Elsevier Inc. All rights reserved.

  2. Cosmic rays exposure during aircraft flight (3). Guideline and dose evaluation

    International Nuclear Information System (INIS)

    Yasuda, Hiroshi

    2007-01-01

    Radiation Council of MEXT drew up the Guideline of Cosmic Ray Exposure Control for Air Crew in 2006. The content of the Guideline and evaluation methods of dose are explained. The Guideline stated five items for Airline Company. It consists of 1) exposure dose control for air crew, 2) evaluation methods of cosmic rays exposure dose of air crew, 3) explanation and education of cosmic rays exposure for air crew, 4) reading, record and store of cosmic rays exposure dose of air crew, and 5) health control of air crew. The doses of four airlines were calculated by the Civil Aeromedical Research Institute (CARI) code and the European Program package for the Calculation of Aviation Route Doses (EPCARD) code. The difference of two codes was about 15 to 25%. Japanese Internet System for Calculation of Aviation Route Doses (JISCAED) has been developed by Japan. (S.Y.)

  3. Alteration of the Carbon and Nitrogen Isotopic Composition in the Martian Surface Rocks Due to Cosmic Ray Exposure

    Science.gov (United States)

    Pavlov, A. A.; Pavlov, A. K.; Ostryakov, V. M.; Vasilyev, G. I.; Mahaffy, P.; Steele, A.

    2014-01-01

    C-13/C-12 and N-15/N-14 isotopic ratios are pivotal for our understanding of the Martian carbon cycle, history of the Martian atmospheric escape, and origin of the organic compounds on Mars. Here we demonstrate that the carbon and nitrogen isotopic composition of the surface rocks on Mars can be significantly altered by the continuous exposure of Martian surface to cosmic rays. Cosmic rays can effectively produce C-13 and N-15 isotopes via spallation nuclear reactions on oxygen atoms in various Martian rocks. We calculate that in the top meter of the Martian rocks, the rates of production of both C-13 and N-15 due to galactic cosmic rays (GCRs) exposure can vary within 1.5-6 atoms/cm3/s depending on rocks' depth and chemical composition. We also find that the average solar cosmic rays can produce carbon and nitrogen isotopes at a rate comparable to GCRs in the top 5-10 cm of the Martian rocks. We demonstrate that if the total carbon content in a surface Martian rock is <10 ppm, then the "light," potentially "biological" C-13/C-12 ratio would be effectively erased by cosmic rays over 3.5 billion years of exposure. We found that for the rocks with relatively short exposure ages (e.g., 100 million years), cosmogenic changes in N-15/N-14 ratio are still very significant. We also show that a short exposure to cosmic rays of Allan Hills 84001 while on Mars can explain its high-temperature heavy nitrogen isotopic composition (N-15/N-14). Applications to Martian meteorites and the current Mars Science Laboratory mission are discussed.

  4. Design And Measurement Of Radiation Exposure Rates At An X-Ray Diagnostic Radiological Unit

    International Nuclear Information System (INIS)

    Tito-Sutjipto

    2003-01-01

    Every radiation employees suffers radiation exposure risk while doing his job. It is important therefore to investigate the occupational health and safety of radiation employees on its relationship with the design and measurement of radiation exposure rates at an X-ray diagnostic radiological unit in this work, a case study was held on the radiological unit at BP-4 Yogyakarta for patient diagnostics, This research armed to investigate the relationship between the design of radiological unit for X-ray diagnostics and the location of the X-ray machine, based on the distance variable and radiation exposure rate during patient diagnostics. This was performed using radiological unit design data for X-ray diagnostics and the measurement of radiation exposure rates throughout patient diagnostics. The design data can then be used for determining the requirement of primary and secondary shielding materials for radiological unit as well as a calculation basis of radiation exposure rates during patient diagnostics. From the result of the research, it can be concluded that from the occupational health and safety point of view, radiation exposure around the X-ray machines are fairly good, both for the shielding materials in each X-ray room and the radiation exposures received by the workers, because they are far beyond the maximum permittable average limit (16.67 m R/days). (author)

  5. PCB exposure and cochlear function at age 6 years.

    Science.gov (United States)

    Palkovičová Murínová, Ľubica; Moleti, Arturo; Sisto, Renata; Wimmerová, Soňa; Jusko, Todd A; Tihányi, Juraj; Jurečková, Dana; Kováč, Ján; Koštiaková, Vladimíra; Drobná, Beata; Trnovec, Tomáš

    2016-11-01

    Epidemiological studies have documented adverse associations between exposure to polychlorinated biphenyls (PCBs) and otological outcomes. Previously, we documented decreased distortion product otoacoustic emission (DPOAE) levels in children exposed to PCBs, up to the age of 45 months, amongst a cohort of children in eastern Slovakia. The objective of the present study is to evaluate cochlear dysfunction at 72 months of age in 214 children from this same cohort and to compare the otoacoustic test sensitivity to that of pure tone audiometry (PTA). The association between DPOAE, PTA, and PCBs was estimated by means of multivariate ANOVA (MANOVA) and linear regression models. ROC curves were computed to estimate the DPOAE-test power in children. The DPOAE level at 72 months was related to PCB-153 serum levels. The DPOAE Input/Output function test at mid-frequency (2kHz) has shown instead nonmonotonic dependence on PCB exposure, for the left ears of children, over the whole growth curve. No significant association was found between PTA hearing levels and PCB-153 concentration. High diagnostic power of the DPOAE-test was found in children, similar to that found by the same authors in adults. In conclusions the DPOAE-PCB correlation obtained at 72 months is similar to that at 45 months suggesting a permanent and stable ototoxic effect of the PCB exposure. The lack of statistical significance of the PCB-PTA correlation suggests that DPOAEs are sensitive biomarkers of cochlear damage. Copyright © 2016 Elsevier Inc. All rights reserved.

  6. The parameters of X-ray equipment that influence in patient exposure

    International Nuclear Information System (INIS)

    Peixoto, J.E.

    1988-01-01

    The main components of the X-rays equipment and the secondary device for radiodiagnosis examination are showed. The influence of all radiographs parameters in human exposure as tension and current are also analysed. (C.G.C.) [pt

  7. Influence of X-ray exposure on morphologic composition of blood of sheep

    International Nuclear Information System (INIS)

    Tukhtaev, T.M.; Badalov, S.

    1983-01-01

    Present article is devoted influence of X-ray exposure on morphologic composition of blood of sheep. Thus, pathogenetic mechanisms of formation of acute radiation sickness of laboratory animals are studied. The experiments are described.

  8. Calibration of diagnostic x-ray machines using radiation exposure and radiographic parameters

    International Nuclear Information System (INIS)

    Agba, E.H.; Uloko, P. I.; Tyovenda, A. A.

    2011-01-01

    Calibration of diagnostic x-ray machines using radiation exposure and radiographic parameters of the x-ray machines has been carried out. Three phase diagnostic x-ray machines situated at Federal Medical Centre, Makurdi, General Hospital, Otukpo and Christian Hospital, Mkar were used for the calibration work. The radiation meter was used to measure x-ray radiation exposure. The result of this work demonstrates mR/mAs=C(KV p ) that there exist a power law relation of the form between the radiation exposure and the radiographic parameters of diagnostic x-ray machines, which can be used to estimate patient exposure during routine x-ray diagnostic examinations for wide range of operating parameters. The values of the power exponent n, constant c and total filtrations of the diagnostic x-ray machines have been estimated. These values for the diagnostic x-ray machines at the Federal Medical Centre, Makurdi are: 2.14, 0.88 and 2.77 respectively, for the one at the General Hospital, Otukpo are: 2.07, 0.76 and 2.68 respectively and that of the Christian Hospital, Mkar are: 2.01,0.69 and 2.61 respectively.

  9. A hard x-ray prototype production exposure station at NSLS

    International Nuclear Information System (INIS)

    Johnson, E.D.; Milne, J.C.

    1997-07-01

    Exposures conducted at the NSLS R and D beamline (X-27B) for High Aspect Ratio Precision Manufacture have proven sufficiently successful that the authors are constructing a dedicated hard x-ray exposure beamline. The new beamline (X-14B) provides an exposure field ∼ 120 mm wide, three times larger than that of X-27B. The scanner is based on the hydraulic system from the X-27B program. It is optimized for planar exposures and takes advantage of the full 525 mm stroke available. Exposures of multiple substrates and masks will be possible, with the fixturing supporting mounting of substrate holders from other groups (ALS, APS, CAMD, and UW). The function of this beamline is to establish a hard x-ray exposure station where manufacturing scale protocols can be developed and ultimately exploited for production runs

  10. Risk evaluation of cosmic-ray exposure in long-term manned space mission

    International Nuclear Information System (INIS)

    Fujitaka, Kazunobu; Majima, Hideyuki; Ando, Koichi; Yasuda, Hiroshi; Suzuki, Masao

    1999-03-01

    Long-term manned space missions are planned to be implemented within the first two decades of the 21st century. The International Space Station (ISS) will be ready to run, and a plan to visit Mars is also under way. Humans will live in space for long periods of time and we are planning to do experiments in space to examine various aspects of space science. The main risk in long-term manned space missions is large exposure to space radiation. Human safety must be ensured in space where exposure to cosmic rays is almost 1 mSv a day. As such missions will inevitably result in significant exposure for astronauts, there is increasing need to protect them adequately based on both physical and biological knowledge. A good method to evaluate realistic risk associated with space missions will be in urgent demand. At the National Institute of Radiological Sciences (NIRS), Chiba, Japan, a research institutes of the Science Technology Agency of Japan, high energy cosmic radiation can be simulated only with heavy ion irradiation accelerated by the particle accelerator, Heavy Ion Medical Accelerator (HIMAC). Research to evaluate risk of space radiation, including physical measurement techniques, protective effects, biological effects and risk adjustment, aging, neuronal cell damage and cancer risk are undergoing. We organized a workshop of the latest topics and experimental results of physics and biology related to space radiation supported by Japan Science and Technology Corporation (JST). This workshop was held as a satellite meeting associated with the 32nd Committee on Space Research (COSPAR) Scientific Assembly (Nagoya, July 12-19th, 1998). This volume is an extended proceedings of the workshop. The proceedings contain six main subjects covering the latest information on Risk Evaluation of Cosmic-Ray Exposure in Long-Term Manned Space Mission'. 1. Risk Estimation of Heavy Ion Exposure in Space. 2. Low Dose-Rate Effects and Microbeam-Related Heavy Ions. 3. Chromosome and

  11. Statistical investigation on frequency, duration, number of X-ray investigations and radiation exposure to the patients of a district hospital on the outskirts of Munich

    Energy Technology Data Exchange (ETDEWEB)

    Nordmann, W

    1973-04-10

    Within the framework of a dissertation, X-ray examined patients were statistically surveyed during one month at the district hospital. The radiation exposure of the patients increased strongly particularly with men of the age of 21 to 30 and of 61 to 70. The causes are the multiply performed investigations after accidents as well as angiography at greater ages. The exposure is in the case of women particularly high between the ages of 66 and 70. In determining the gonadal exposure, the average values for the X-ray investigation at the time were referred to. The numbers give an approximate idea of to what extent single investigations with varying investigation or picture frequency can contribute to gonadal exposure.

  12. Aging and bone. X-ray bone densitometry

    Energy Technology Data Exchange (ETDEWEB)

    Morita, Rikushi (Shiga Univ. of Medical Sciences, Otsu (Japan))

    1994-01-01

    Bone mass at all ages of the individuals is the integration of genetic factors, nutrition, physical exercise, hormonal environments, and other factors influencing the bone. It is also a measurable risk factor for osteoporosis which may subsequently cause bone fractures. Thus measuring bone mass is required to predict the probability of developing bone fractures subsequent to osteoporosis, and to diagnose osteoporosis, and to manage the osteoporosis patient. This paper discusses bone mineral measurements according to their characteristics and clinical application. Methodology for measuring bone mass has rapidly progressed during the past 15 years, which covers photodensitometry, photon absorptiometry (single energy X-ray absorptiometry and dual energy X-ray absorptiometry), quantitative CT, and ultrasound. These techniques have allowed noninvasive measurement of bone mineral density in any site of the skeleton with high accuracy and precision, although a single use of the technique cannot satisfy the complete clinical requirements. Thus the most appropriate method for measuring bone mineral density is important to monitor bone mass change and according to the specific site. (N.K.).

  13. Aging and bone. X-ray bone densitometry

    International Nuclear Information System (INIS)

    Morita, Rikushi

    1994-01-01

    Bone mass at all ages of the individuals is the integration of genetic factors, nutrition, physical exercise, hormonal environments, and other factors influencing the bone. It is also a measurable risk factor for osteoporosis which may subsequently cause bone fractures. Thus measuring bone mass is required to predict the probability of developing bone fractures subsequent to osteoporosis, and to diagnose osteoporosis, and to manage the osteoporosis patient. This paper discusses bone mineral measurements according to their characteristics and clinical application. Methodology for measuring bone mass has rapidly progressed during the past 15 years, which covers photodensitometry, photon absorptiometry (single energy X-ray absorptiometry and dual energy X-ray absorptiometry), quantitative CT, and ultrasound. These techniques have allowed noninvasive measurement of bone mineral density in any site of the skeleton with high accuracy and precision, although a single use of the technique cannot satisfy the complete clinical requirements. Thus the most appropriate method for measuring bone mineral density is important to monitor bone mass change and according to the specific site. (N.K.)

  14. Determination of existing exposure level of population during X ray investigations

    International Nuclear Information System (INIS)

    Tselinov, N.V.; Kudritskij, Yu.K.

    1978-01-01

    The distribution of X ray procedures among 500 inhabitants of the city of Vorkuta in 1975 is studied. Data on the distribution of the subjects by age group and type of X ray procedure are presented. The results obtained broaden the existing concepts on hygienic importance of radiation received by the population of the country during X ray studies. It is proposed that these results be used in developing methods for standardizing X ray procedures

  15. Bone age assessment by dual-energy X-ray absorptiometry in children: an alternative for X-ray?

    Science.gov (United States)

    Heppe, D H M; Taal, H R; Ernst, G D S; Van Den Akker, E L T; Lequin, M M H; Hokken-Koelega, A C S; Geelhoed, J J M; Jaddoe, V W V

    2012-02-01

    The aim of the study was to validate dual-energy X-ray absorptiometry (DXA) as a method to assess bone age in children. Paired dual-energy X-ray absorptiometry (DXA) scans and X-rays of the left hand were performed in 95 children who attended the paediatric endocrinology outpatient clinic of University Hospital Rotterdam, the Netherlands. We compared bone age assessments by DXA scan with those performed by X-ray. Bone age assessment was performed by two blinded observers according to the reference method of Greulich and Pyle. Intra-observer and interobserver reproducibility were investigated using the intraclass correlation coefficient (ICC), and agreement was tested using Bland and Altman plots. The intra-observer ICCs for both observers were 0.997 and 0.991 for X-ray and 0.993 and 0.987 for DXA assessments. The interobserver ICC was 0.993 and 0.991 for X-ray and DXA assessments, respectively. The mean difference between bone age assessed by X-ray and DXA was 0.11 years. The limits of agreement ranged from -0.82 to 1.05 years, which means that 95% of all differences between the methods were covered by this range. Results of bone age assessment by DXA scan are similar to those obtained by X-ray. The DXA method seems to be an alternative for assessing bone age in a paediatric hospital-based population.

  16. X-ray detector for automatic exposure control using ionization chamber filled with xenon gas

    CERN Document Server

    Nakagawa, A; Yoshida, T

    2003-01-01

    This report refers to our newly developed X-ray detector for reliable automatic X-ray exposure control, which is to be widely used for X-ray diagnoses in various clinical fields. This new detector utilizes an ionization chamber filled with xenon gas, in contrast to conventional X-ray detectors which use ionization chambers filled with air. Use of xenon gas ensures higher sensitivity and thinner design of the detector. The xenon gas is completely sealed in the chamber, so that the influence of the changes in ambient environments is minimized. (author)

  17. Cytogenetic analysis in peripheral blood lymphocytes after arteriography (exposure to X-rays and contrast medium)

    International Nuclear Information System (INIS)

    Hadjidekova, V.; Popova, L.; Hristova, R.; Hadjidekov, V.

    2006-01-01

    Full text: The purpose of our study is to investigate the cytogenetic effects in peripheral blood lymphocytes of 29 patients who had undergone diagnostic angiography. Peripheral blood samples were taken from 22 patients submitted to renal arteriography and 7 patients submitted to cerebral arteriography (17 male and 12 female, aged between 13 and 68 years). Cytogenetic analysis was performed in peripheral lymphocytes before the procedure, immediately after and 24 hours later. The entrance skin dose obtained during the whole diagnostic X-ray exposure was measured by thermoluminescent dosimeters and varied between 0.03 - 0.30 Gy. Both low and high osmolarity contrast media were used. Chromosomal aberrations and micronuclei frequency was used as biomarkers of genotoxicity. The estimated frequency of chromosomal aberrations and micronuclei in peripheral blood lymphocytes of patients after arteriography examination is significantly higher than the level before the diagnostic exposure. The mean frequency of cells with chromosomal aberrations nearly double after examination and remained constant at 24h analysis. Radiological diagnostic procedures involving iodinated contrast media as arteriography may cause a significant increase of the cytogenetic injury in peripheral blood lymphocytes

  18. Cytogenetic analysis of peripheral blood lymphocytes after arteriography (exposure to x-rays and contrast medium)

    International Nuclear Information System (INIS)

    Popova, L.; Hadjidekova, V.; Karadjov, G.; Agova, S.; Traskov, D.; Hadjidekov, V.

    2005-01-01

    Backgrounds. The purpose of our study is to investigate the cytogenetic analysis findings in peripheral blood lymphocytes of 29 patients who had undergone diagnostic radiography. Methods. Peripheral blood samples were taken from 22 patients submitted to renal arteriography and 7 patients submitted to cerebral arteriography (17 male and 12 female, aged between 13-68 years). Cytogenetic analyses of peripheral lymphocytes were performed before the procedure, immediately after and 24 hours later. The entrance skin dose obtained during the whole diagnostic X-ray exposure was measured by thermoluminescent dosimeters and varied between 0.03-0.30 Gy. Both low and high osmolarity contrast media were used. Chromosomal aberrations and micronuclei frequency were used as biomarkers of genotoxicity. Results. The estimated frequency of chromosomal aberrations and micronuclei in the peripheral blood lymphocytes of patients after arteriography examination was significantly higher than the level before the diagnostic exposure. The mean frequency of cells with chromosomal aberrations was nearly double after examination and proved to be constant in the analysis after 24 hours. Conclusions. Radiological diagnostic procedures involving iodinated contrast media as arteriography may cause a significant increase in cytogenetic damage in peripheral blood lymphocytes. (author)

  19. Exposure measurement in the neighboring hospital beds during an x-ray procedure in hospitalization unit

    Energy Technology Data Exchange (ETDEWEB)

    Goto, Rafael E.; Capeleti, Felipe F.; Cabete, Henrique V., E-mail: rafael.goto@fcmsantacasasp.edu.br, E-mail: felipe.capeleti@fcmsantacasasp.edu.br, E-mail: henrique@gmpbrasil.com.br [Faculdade de Ciencias Medicas da Santa Casa Sao Paulo, SP (Brazil); GMP Consultoria em Radioprotecao e Fisica Medica e Assessoria LTDA, Sao Paulo, SP (Brazil)

    2017-11-01

    There are lots of discussion about the exposure in hospitalization units in Brazil, especially around labor legislation and economic advantages of unhealthiness. With the attention focused on hospitalized patients, there were measured the exposure in neighboring beds of the patient submitted to an X-ray procedure with a mobile X-ray system that could be used to illustrate the discussion with consistent values. The most common X-ray procedure made in hospitalization units are chests images with techniques between 70 to 120 kV and 5 to 20 mAs. The measurement was made during routine exposure and simulations using a scattering phantom with Radcal AccuPro electrometer and 1800cc ionization chamber in a private hospital and a philanthropic hospital, both in Sao Paulo, Brazil. The ionization chambers are placed at 2 meters distance of the patient exposed of both sides during the routine procedure. During the simulation, a nylon phantom of 20 centimeters thick and 30 x 30 cm² size was placed on the bed, a typical exposure technique was used and the exposure was measured surrounding the phantom at 0.6, 1.0 and 2.0 meters distance for scattered radiation characterization. Initial results showed that the neighboring exposure at about 2 meters distance from the exposed patient bed have low values, even when exposure is integrated during the length of hospital stay. Therefore, the exposure in hospitalization units are very low compared to the exams doses. (author). (author)

  20. Prolonged neuroinflammation after lipopolysaccharide exposure in aged rats.

    Directory of Open Access Journals (Sweden)

    Hui Qun Fu

    Full Text Available Inflammation is a hallmark of several disease states ranging from neurodegeneration to sepsis but is also implicated in physiological processes like ageing. Non-resolving inflammation and prolonged neuroinflammation are unclear processes implicated in several conditions, including ageing. In this study we studied the long-term effects of endotoxemia, as systemic lipopolysaccharide (LPS injection, focusing on the role of astrocyte activation and cytokine release in the brain of aged rats. A single dose of LPS (2 mg/kg or 0.9% saline was injected intraperitoneally in aged rats. Levels of pro-inflammatory cytokines (TNFα and IL-1β and NF-κB p65 activation were measured systemically and in hippocampal tissue. Astrocytes and cytokines release in the CNS were detected via double immunofluorescence staining at different time-points up to day 30. Serum levels of TNFα and IL-1β were significantly increased acutely after 30 minutes (p<0.001 and up to 6 hours (p<0.001 following LPS-injection. Centrally, LPS-treated rats showed up-regulated mRNA expression and protein levels of pro-inflammatory cytokines in the hippocampus. These changes associated with astrogliosis in the hippocampus dentate gyrus (DG, IL-1β immunoreactivity and elevated NF-κB p65 expression up to day 30 post LPS exposure. Overall, these data demonstrate that LPS induces prolonged neuroinflammation and astrocyte activation in the hippocampus of aged rats. Hippocampal NF-κB p65 and excessive astrocytes-derived IL-1β release may play a pivotal role in regulating long-lasting neuroinflammation.

  1. Energy and rate dependence of diagnostic x-ray exposure meters

    International Nuclear Information System (INIS)

    Wagner, L.K.; Cerra, F.; Conway, B.; Fewell, T.R.; Ohlhaber, T.R.

    1988-01-01

    Variations in x-ray exposure measurements among a variety of contemporary diagnostic exposure meters are investigated. Variations may result from systematic errors due to calibration, beam-quality dependence and exposure-rate dependence. It is concluded that the majority of general purpose diagnostic meters will agree to within 10% of each other if exposure rates are below 1.3 mC kg-1S-1 of air (5 R s-1) and beam qualities are typical for general purpose radiology, excluding mammography. For exposure rates comparable to those in barium enema radiography the variations can range up to 25% or more. Variations up to 40% were observed among general purpose exposure meters at mammographic beam qualities. In the mammographic range, mammographic (thin window) exposure meters varied by no more than 2%

  2. [Evaluation of dental X-ray apparatus in terms of patient exposure to ionizing radiation].

    Science.gov (United States)

    Olszewski, Jerzy; Wrzesień, Małgorzata

    2017-06-27

    The use of X-ray in dental procedures causes exposure of the patient to ionizing radiation. This exposure depends primarily on the parameters used in tooth examination. The aim of the study was to determine the patients exposure and to assess the technical condition of X-ray tubes. Seventeen hundred dental offices were covered by the questionnaire survey and 740 questionnaires were sent back. Direct measurements were performed in 100 units by using the thermoluminescent detectors and X-ray films. The results showed that the most commonly used exposure time is 0.22±0.16 s. The average entrance dose for the parameters used most commonly by dentists is 1.7±1.4 mGy. The average efficiency of X-ray tube estimated on the basis of exposures is 46.5±23.7 μGy/mAs. The study results indicate that the vast majority of X-ray tubes meet the requirements specified in the binding regulations. Med Pr 2017;67(4):491-496. This work is available in Open Access model and licensed under a CC BY-NC 3.0 PL license.

  3. Determination of personnel exposures in the lower energy ranges of X-ray by photographic dosimeter

    International Nuclear Information System (INIS)

    Ha, C.W.; Kim, J.R.; Suk, K.W.

    1986-01-01

    This paper described an improved technical method required for proper evaluation of personnel exposures by means of the photographic dosimeter developed by KAERI in lower gamma or X-ray energy regions, with which response of the dosimeter varies significantly. With calibration of the dosimeter in the energy range from 30 to 300 keV, the beam spectrum was carefully selected and specified it adequately. The absorber combinations and absorber thickness used to obtain the specified X-ray spectra from a constant potential X-ray machine were determined theoretically and also experimentally. A correlation between the density and exposure for the four separate energies, such as 49 keV eff , 154 keV eff 250 keV eff and 662 keV, is experimentally determined. As a result, it can be directly evaluated the exposure from the measured response of dosimeter. (Author)

  4. Patient dose evaluations from medical X-ray exposure in Italy: an analysis of next data

    International Nuclear Information System (INIS)

    Marchetti, A.; Paganini, F.M.; Susanna, A.

    1980-01-01

    NEXT (Nationwide Evaluation of X-ray Trends) is a program for the evaluation of patient exposure in X-ray diagnostic tests. The program is aimed at reducing patient exposure by pin-pointing poor radiological techniques and improving them. CNEN (Comitato Nazionale per l'Energia Nucleare) and ISS (Istituto Superiore di Sanita) have been developing such a program in Italy since 1976. Up to now two regional administrations applied the method and regional operators collected the needed data in all the medical institutions in their areas. The results show a wide spread of values for all the parameters studied in the 12 X-ray projections selected. Gonad dose and skin entrance exposure were found to be spread over a range up to about two orders of magnitude. (H.K.)

  5. Phototimer for automatic control of x-ray exposure, PT-20A

    Energy Technology Data Exchange (ETDEWEB)

    Ohno, H; Itoh, K; Ogura, I; Yasuhara, H; Sugimoto, H [Toshiba Corp., Kawasaki, Kanagawa (Japan)

    1979-02-01

    The phototimer as an exposure control device is now required to have higher accuracy and wider range of control to comply with the recent trends of x-ray diagnosis, such as toward short-time exposure due to increased output power of x-ray apparatus and toward one-man operation. In order to meet the requirement, the x-ray characteristics of the components of the phototimer have been examined, and computer simulation of x-ray spectra and dynamic characteristics of every component have been investigated, in pursuit of the essential characters of phototimers. On the basis of these analytical investigations, the phototimer PT-20A is so designed as to compensate for density deviation under various kVp and object thickness: uniform density has been obtained under practical radiographic conditions.

  6. Early age exposure to moisture damage and systemic inflammation at the age of 6 years.

    Science.gov (United States)

    Karvonen, A M; Tischer, C; Kirjavainen, P V; Roponen, M; Hyvärinen, A; Illi, S; Mustonen, K; Pfefferle, P I; Renz, H; Remes, S; Schaub, B; von Mutius, E; Pekkanen, J

    2018-05-01

    Cross-sectional studies have shown that exposure to indoor moisture damage and mold may be associated with subclinical inflammation. Our aim was to determine whether early age exposure to moisture damage or mold is prospectively associated with subclinical systemic inflammation or with immune responsiveness in later childhood. Home inspections were performed in children's homes in the first year of life. At age 6 years, subclinical systemic inflammation was measured by serum C-reactive protein (CRP) and blood leukocytes and immune responsiveness by ex vivo production of interleukin 1-beta (IL-1β), IL-6, and tumor necrosis factor alpha (TNF-α) in whole blood cultures without stimulation or after 24 hours stimulation with phorbol 12-myristate 13-acetate and ionomycin (PI), lipopolysaccharide (LPS), or peptidoglycan (PPG) in 251-270 children. Moisture damage in child's main living areas in infancy was not significantly associated with elevated levels of CRP or leukocytes at 6 years. In contrast, there was some suggestion for an effect on immune responsiveness, as moisture damage with visible mold was positively associated with LPS-stimulated production of TNF-α and minor moisture damage was inversely associated with PI-stimulated IL-1β. While early life exposure to mold damage may have some influence on later immune responsiveness, it does not seem to increase subclinical systemic inflammation in later life. © 2018 National Institute for Health and Welfare, Finland Indoor Air published by John Wiley & Sons Ltd.

  7. High precision instrumentation for measuring the true exposure time in diagnostic X-ray examinations

    International Nuclear Information System (INIS)

    Silva, Danubia B.; Santos, Marcus A.P.; Barros, Fabio R.; Santos, Luiz A.P.

    2013-01-01

    One of the most important physical quantities to be evaluated in diagnostic radiology is the radiation exposure time experimented by the patient during the X-ray examination. IAEA and WHO organizations have suggested that any country must create a quality surveillance program to verify if each type of ionizing radiation equipment used in the hospitals and medical clinics are in conformity with the accepted uncertainties following the international standards. The purpose of this work is to present a new high precision methodology for measuring true exposure time in diagnostic X-ray examinations: pulsed, continuous or digital one. An electronic system named CronoX, which will be soon registered at the Brazilian Patent Office (INPI), is the equipment that provides such a high precision measurement. The principle of measurement is based on the electrical signal captured by a sensor that enters in a regeneration amplifier to transform it in a digital signal, which is treated by a microprocessor (uP). The signal treatment results in a two measured times: 1) T rx , the true X-ray exposure time; 2) T nx , the time in which the X-ray machine is repeatedly cut off during the pulsed irradiation and there is no delivery dose to the patient. Conventional Polymat X-ray equipment and dental X-ray machines were used to generate X-ray photons and take the measurements with the electronic systems. The results show that such a high precision instrumentation displays the true exposure time in diagnostic X-ray examinations and indicates a new method to be purposed for the quality surveillance programs in radiology. (author)

  8. The primary exposure standard of ENEA for medium energy X-ray: characteristics and measurements procedures

    International Nuclear Information System (INIS)

    Laitano, R.F.; Toni, M.P.

    1983-01-01

    A description is given of a medium energy X-ray free-air chamber used, as primary exposure standard, at the Laboratorio di Metrologia delle Radiazioni Ionizzanti of the Enea in Italy. The main features of an X-ray facility for the production of radiation between 40 KeV and 400 KeV are also described. The measurements procedures are then analyzed with respect to the realization of the exposure unit in the relevant energy range. Finally the results of some international comparisons are reported

  9. Influence of chronic x-ray exposure on adrenal glucocorticoid function and adrenocorticocyte membrane potential

    International Nuclear Information System (INIS)

    Gorban', Je.M.; Topol'nikova, N.V.

    1998-01-01

    The peculiarities of adrenal glucocorticoid function and membrane potential (MP) of zona fasciculata adrenocorticocyte (ACC) in rats after chronic x-ray exposure was studied. The changes of adrenal glucocorticoid function caused by chronic x-ray exposure within a relatively small period of irradiation (1.5 months) are obscure and manifest themselves only at physiological load. With the prolongation of the period (8 and 15 months), more considerable inhibition of the adrenal glucocorticoid function and disturbances in the membrane mechanisms of ACC MP level regulation are revealed

  10. Radiation exposure in X-ray angiography and comparisons between digital and conventional methods of imaging

    International Nuclear Information System (INIS)

    Schaberg, J.

    1987-01-01

    The more recent developments and techniques in the field of angiography are examined for associated radiation exposure risks for patients and investigators and then compared to the conventional methods of angiography. It could be shown that digital subtraction angiography is generally associated with a lesser risk of somatic exposure of the patient, provided that the equipment used offers an adjustable useful-beam range and focus. The fact that above-table X-ray tubes are now generally replaced with X-ray systems installed under the examination table permits the relatively high doses, to which investigators are exposed during angiography, to be reduced by a factor of 3. (DG) [de

  11. An industrial radiography exposure device based on measurement of transmitted gamma-ray intensity

    International Nuclear Information System (INIS)

    Polee, C; Chankow, N; Srisatit, S; Thong-Aram, D

    2015-01-01

    In film radiography, underexposure and overexposure may happen particularly when lacking information of specimen material and hollowness. This paper describes a method and a device for determining exposure in industrial gamma-ray radiography based on quick measurement of transmitted gamma-ray intensity with a small detector. Application software was developed for Android mobile phone to remotely control the device and to display counting data via Bluetooth communication. Prior to film exposure, the device is placed behind a specimen to measure transmitted intensity which is inversely proportional to the exposure. Unlike in using the conventional exposure curve, correction factors for source decay, source-to- film distance, specimen thickness and kind of material are not needed. The developed technique and device make radiographic process economic, convenient and more reliable. (paper)

  12. Differences in responses to X-ray exposure between osteoclast and osteoblast cells

    International Nuclear Information System (INIS)

    Zhang, Jian; Wang, Ziyang; Wu, Anqing; Nie, Jing; Pei, Hailong; Hu, Wentao; Wang, Bing; Shang, Peng; Li, Bingyan; Zhou, Guangming

    2017-01-01

    Radiation-induced bone loss is a potential health concern for cancer patients undergoing radiotherapy. Enhanced bone resorption by osteoclasts and decreased bone formation by osteoblasts were thought to be the main reasons. In this study, we showed that both pre-differentiating and differentiating osteoclasts were relatively sensitive to X-rays compared with osteoblasts. X-rays decreased cell viability to a greater degree in RAW264.7 cells and in differentiating cells than than in osteoblastic MC3T3-E1 cells. X-rays at up to 8 Gy had little effects on osteoblast mineralization. In contrast, X-rays at 1 Gy induced enhanced osteoclastogenesis by enhanced cell fusion, but had no effects on bone resorption. A higher dose of X-rays at 8 Gy, however, had an inhibitory effect on bone resorption. In addition, actin ring formation was disrupted by 8 Gy of X-rays and reorganized into clusters. An increased activity of Caspase 3 was found after X-ray exposure. Actin disorganization and increased apoptosis may be the potential effects of X-rays at high doses, by inhibiting osteoclast differentiation. Taken together, our data indicate high radiosensitivity of osteoclasts. X-ray irradiation at relatively low doses can activate osteoclastogenesis, but not osteogenic differentiation. The radiosensitive osteoclasts are the potentially responsive cells for X-ray-induced bone loss.

  13. Comparison of cytogenetic effects after occupational exposure to X-rays with those after foetal pelvimetric exposure

    International Nuclear Information System (INIS)

    Kirsch-Volders, M.; Poma, K.; Verschaeve, L.; Hens, L.; Susanne, C.; Elegem, P. van

    1978-01-01

    In utero acute low-level exposure to X-rays (300 to 350 mrads) induces a significant increase of band-loss in G-trypsin banded chromosomes of umbilical lymphocytes. Results, however, have to be confirmed by dose-effect relation studies and analysis with spectro-photometric scanning of deleted chromosomes. The same in utero exposure induces a significant dissociaton of chromosome pair 13 as revealed by centromere-centromere, angle and association tendency analysis of chromosome distribution in comparison with a control group. Occupational chronic low-level exposure to ionizing radiation does not modify significantly the amount of SCE in lymphocytes of peripheral blood. However, an analysis of centromere-centromere distances, angle values and associaton tendencies of the different chromosome combinations clearly shows an association of chromosome pair 12-16 after exposure to ionizing radiation. It is difficult to assess the exact biological importance of the observed chromosome modifications. However, referring to the already described dissociation of human acrocentric chromosomes after in vivo exposure to low levels of phenyl Hg acetate or inorganic Pb, the chromosome distribution seems not to be significantly disturbed by chronic or acute low-level exposure to ionizing radiation. (author)

  14. Cl36 and the age of the cosmic rays

    International Nuclear Information System (INIS)

    Casse, M.; Goret, P.; Regnier, S.

    1975-01-01

    The radioactive isotope 36 Cl (tau=γx3.10 5 y) is used as a time reference for the propagation of cosmic rays. New measurements of the production cross section of 36 Cl in Ti and Fe at 24GeV will be presented. A critical analysis of the cross sections leads to an estimate of the ratio 36 Cl/Cl=0.030+0.007 in the arriving cosmic rays. The comparison between the expected abundance of Cl in the arriving cosmic rays and the observations tend to support the decay of 36 Cl. The inferred cosmic ray confinement time is about 10 6 y [fr

  15. Radiation exposure and image quality in x-Ray diagnostic radiology physical principles and clinical applications

    CERN Document Server

    Aichinger, Horst; Joite-Barfuß, Sigrid; Säbel, Manfred

    2012-01-01

    The largest contribution to radiation exposure to the population as a whole arises from diagnostic X-rays. Protecting the patient from radiation is a major aim of modern health policy, and an understanding of the relationship between radiation dose and image quality is of pivotal importance in optimising medical diagnostic radiology. In this volume the data provided for exploring these concerns are partly based on X-ray spectra, measured on diagnostic X-ray tube assemblies, and are supplemented by the results of measurements on phantoms and simulation calculations.

  16. Exposure doses of the patient and the medical staff during urological X-ray examens

    International Nuclear Information System (INIS)

    Vogel, H.; Loehr, H.; Haug, P.; Schuett, B.

    1977-01-01

    During 32 intravenous urografies and 48 angiografies of the kidney and the suprarenal glands the X-ray doses at the patient's skin and gonades were determined. During the angiografies the doses were mesured at the hands. the gonades and the front (eyes) of the medical staff. The results are discussed. Because the X-ray doses are relatively high, the number of the pictures and the exposure time is to be reduced to the minimum. Clinical experience and special knowledge is the best X-ray protection. (orig.) [de

  17. Color change of gemstones by exposure to gamma rays

    Energy Technology Data Exchange (ETDEWEB)

    Lima, Giovanna L.C. de; Lameiras, Fernando S., E-mail: giovannalarissa17@hotmail.com, E-mail: fsl@cdtn.br [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil)

    2015-07-01

    A gem is appreciated by collectors and, when polished, widely used for jewelry manufacturing. For example, when quartz naturally or artificially acquires a color it becomes a gemstone (smoky quartz, morion, citrine, amethyst, or prasyolite). The presence of chromophore elements in a quartz sample was analysed by Fourier transform infrared spectrometry (FTIR). With a semi-quantitative analysis of the absorption FTIR spectra, it was possible to predict if colorless quartz has the potential to develop color when exposed to ionizing radiation and heat. Specific absorption bands show the presence of chromophore elements in quartz such as aluminum, iron, hydrogen, sodium, or lithium. Considering the ratio of the heights of the absorption bands of these elements, it was possible to predict the color quartz can develop. Samples of irradiated dark and light violet fluorites were analyzed by FTIR and energy-dispersive X-rays spectroscopy. The light violet samples has higher content of calcium relative to fluorine, as well higher content of hydroxyl, probably replacing fluorine in crystal lattice. Hydroxyls cannot be precursors of F color centers, which are the cause of violet color in fluorite, explaining the light violet color of hydroxyl-rich samples. (author)

  18. Color change of gemstones by exposure to gamma rays

    International Nuclear Information System (INIS)

    Lima, Giovanna L.C. de; Lameiras, Fernando S.

    2015-01-01

    A gem is appreciated by collectors and, when polished, widely used for jewelry manufacturing. For example, when quartz naturally or artificially acquires a color it becomes a gemstone (smoky quartz, morion, citrine, amethyst, or prasyolite). The presence of chromophore elements in a quartz sample was analysed by Fourier transform infrared spectrometry (FTIR). With a semi-quantitative analysis of the absorption FTIR spectra, it was possible to predict if colorless quartz has the potential to develop color when exposed to ionizing radiation and heat. Specific absorption bands show the presence of chromophore elements in quartz such as aluminum, iron, hydrogen, sodium, or lithium. Considering the ratio of the heights of the absorption bands of these elements, it was possible to predict the color quartz can develop. Samples of irradiated dark and light violet fluorites were analyzed by FTIR and energy-dispersive X-rays spectroscopy. The light violet samples has higher content of calcium relative to fluorine, as well higher content of hydroxyl, probably replacing fluorine in crystal lattice. Hydroxyls cannot be precursors of F color centers, which are the cause of violet color in fluorite, explaining the light violet color of hydroxyl-rich samples. (author)

  19. Solar Flare Track Exposure Ages in Regolith Particles: A Calibration for Transmission Electron Microscope Measurements

    Science.gov (United States)

    Berger, Eve L.; Keller, Lindsay P.

    2015-01-01

    Mineral grains in lunar and asteroidal regolith samples provide a unique record of their interaction with the space environment. Space weathering effects result from multiple processes including: exposure to the solar wind, which results in ion damage and implantation effects that are preserved in the rims of grains (typically the outermost 100 nm); cosmic ray and solar flare activity, which result in track formation; and impact processes that result in the accumulation of vapor-deposited elements, impact melts and adhering grains on particle surfaces. Determining the rate at which these effects accumulate in the grains during their space exposure is critical to studies of the surface evolution of airless bodies. Solar flare energetic particles (mainly Fe-group nuclei) have a penetration depth of a few millimeters and leave a trail of ionization damage in insulating materials that is readily observable by transmission electron microscope (TEM) imaging. The density of solar flare particle tracks is used to infer the length of time an object was at or near the regolith surface (i.e., its exposure age). Track measurements by TEM methods are routine, yet track production rate calibrations have only been determined using chemical etching techniques [e.g., 1, and references therein]. We used focused ion beam-scanning electron microscope (FIB-SEM) sample preparation techniques combined with TEM imaging to determine the track density/exposure age relations for lunar rock 64455. The 64455 sample was used earlier by [2] to determine a track production rate by chemical etching of tracks in anorthite. Here, we show that combined FIB/TEM techniques provide a more accurate determination of a track production rate and also allow us to extend the calibration to solar flare tracks in olivine.

  20. Effect of parents occupational exposures on risk of stillbirth, preterm delivery, and small-for-gestational-age in infants

    International Nuclear Information System (INIS)

    Savitz, D.A.; Whelan, E.A.; Kleckner, R.C.

    1989-01-01

    Epidemiologic research on the effects of parental occupational exposures on fetal development has been limited. The National Natality and Fetal Mortality surveys obtained applicable data of probability samples of live births and fetal deaths which occurred in the US in 1980 among married women. Analyses were conducted for case groups of stillbirths (2,096 mothers, 3,170 fathers), preterm deliveries (<37 weeks completed gestation) (363 mothers, 552 fathers), and small-for gestational-age infants (218 mothers, 371 fathers) compared with controls. Occupational exposures were defined by industry of employment and by imputed exposures based on a job-exposure linkage system. For stillbirth, maternal work in the rubber, plastics, and synthetics industry and lead exposure and paternal employment in the textile industry had the largest odds ratios. Preterm birth was most strongly associated with maternal lead exposure, corroborating previous findings. Twofold increased risk of preterm delivery was found with paternal employment in the glass, clay, and stone; textile; and mining industries. Paternal exposures to x-rays and polyvinyl alcohol were associated with 1.5-fold increase in risk. The occupation of the mother was not associated with delivery of a small-for-gestational-age infant, in contrast to paternal employment in the art and textile industries. Several toxic agents were associated with risk elevation of 1.3 or greater for fathers, most notably benzene

  1. Hygiene implications associated with x-ray exposures to dental patients

    International Nuclear Information System (INIS)

    McKlveen, J.W.

    1980-01-01

    An elastic mask worn by patients, then a skeleton encased in plastic, was instrumented with LiF thermoluminescent dosimeters to quantify radiation exposures delivered from full-face diagnostic dental x-rays. Locations of interest included skin surface, eyes, upper and lower teeth and thyroid. Exposures in the 100 mR range were common and a maximum of over 6000 mR was measured in the teeth region during a full-face examination with a periapical unit. In general, exposures received from periapical equipment were several times those obtained from panoramic devices

  2. Rock Formation and Cosmic Radiation Exposure Ages in Gale Crater Mudstones from the Mars Science Laboratory

    Science.gov (United States)

    Mahaffy, Paul; Farley, Ken; Malespin, Charles; Gellert, Ralph; Grotzinger, John

    2014-05-01

    The quadrupole mass spectrometer (QMS) in the Sample Analysis at Mars (SAM) suite of the Mars Science Laboratory (MSL) has been utilized to secure abundances of 3He, 21Ne, 36Ar, and 40Ar thermally evolved from the mudstone in the stratified Yellowknife Bay formation in Gale Crater. As reported by Farley et al. [1] these measurements of cosmogenic and radiogenic noble gases together with Cl and K abundances measured by MSL's alpha particle X-ray spectrometer enable a K-Ar rock formation age of 4.21+0.35 Ga to be established as well as a surface exposure age to cosmic radiation of 78+30 Ma. Understanding surface exposures to cosmic radiation is relevant to the MSL search for organic compounds since even the limited set of studies carried out, to date, indicate that even 10's to 100's of millions of years of near surface (1-3 meter) exposure may transform a significant fraction of the organic compounds exposed to this radiation [2,3,4]. Transformation of potential biosignatures and even loss of molecular structural information in compounds that could point to exogenous or endogenous sources suggests a new paradigm in the search for near surface organics that incorporates a search for the most recently exposed outcrops through erosional processes. The K-Ar rock formation age determination shows promise for more precise in situ measurements that may help calibrate the martian cratering record that currently relies on extrapolation from the lunar record with its ground truth chronology with returned samples. We will discuss the protocol for the in situ noble gas measurements secured with SAM and ongoing studies to optimize these measurements using the SAM testbed. References: [1] Farley, K.A.M Science Magazine, 342, (2013). [2] G. Kminek et al., Earth Planet Sc Lett 245, 1 (2006). [3] Dartnell, L.R., Biogeosciences 4, 545 (2007). [4] Pavlov, A. A., et al. Geophys Res Lett 39, 13202 (2012).

  3. Occupational exposure of medical staff due to diagnostic X-ray examinations in veterinary medicine

    International Nuclear Information System (INIS)

    Mergel, E.; Feige, S.; Haeusler, U.

    2007-01-01

    The implementation of the Council directive 96/29 EURATOM and the corresponding national Radiation Protection Ordinance and the X-ray Protection Ordinance coming subsequently into effect led to a changed situation regarding the occupational radiation protection in the medical sector. To reduce the occupational exposure of veterinarians and assisting staff in veterinary radiography is particularly challenging as, in opposite to human radiological examination, the presence of staff is indispensable to restrain the patient. Beyond that the relevant literature reports about too high and/or about unnecessary radiation exposures. To gain a comprehensive knowledge upon the possible exposure of involved staff, the variety of typical examination methods in veterinary clinics and at practitioners had been investigated during the daily routine. Dose measurements were performed for different employees during the examinations taking into account several places of exposure (lens, thyroid, chest, hand, gonad, and feet). Veterinary X-ray diagnostic examinations for pets as well as in equine radiography had been accounted for this study. In total, 101 examination methods, 4.484 accompanied examinations and 53.892 single dose readings resulted in a reliable statistical base to set up a 'Job-Exposure-Matrix' allowing the dose assessment for a variable number and kind of examinations. The 'Job-Exposure-Matrix' is believed to be a useful tool for optimization of occupational radiation exposure of veterinarians by appraising the height of a possible dose, forcing a review of the status quo and triggering the improvement of personal protection by establishing adequate measures. (orig.)

  4. Annama H chondrite-Mineralogy, physical properties, cosmic ray exposure, and parent body history

    Czech Academy of Sciences Publication Activity Database

    Kohout, Tomáš; Haloda, J.; Halodová, P.; Meiner, M. M. M.; Maden, C.; Busemann, H.; Laubenstein, M.; Caffee, M. W.; Welten, K.C.; Hopp, J.; Trieloff, M.; Mahajan, R. R.; Naik, S.; Trigo-Rodríguez, J.M.; Moyano-Cambero, C. E.; Oshtrakh, M. I.; Maksimova, A. A.; Chukin, A. V.; Semionkin, V. A.; Karabanalov, M. S.; Felner, I.; Petrova, E. V.; Brusnitsyna, E. V.; Grokhovsky, V. I.; Yakovlev, G. A.; Gritsevich, M.; Lyytinen, E.; Moilanen, J.; Kruglikov, N. A.; Ishchenko, A. V.

    2017-01-01

    Roč. 52, č. 8 (2017), s. 1525-1541 ISSN 1086-9379 Institutional support: RVO:67985831 Keywords : Annama * chondrite * cosmic-ray exposure * radionuclide Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics OBOR OECD: Astronomy (including astrophysics,space science) Impact factor: 2.391, year: 2016

  5. Uncertainties of exposure-related quantities in mammographic x-ray unit quality control

    International Nuclear Information System (INIS)

    Gregory, Kent J.; Pattison, John E.; Bibbo, Giovanni

    2006-01-01

    Breast screening programs operate in many countries with mammographic x-ray units subject to stringent quality control tests. These tests include the evaluation of quantities based on exposure measurements, such as half value layer, automatic exposure control reproducibility, average glandular dose, and radiation output rate. There are numerous error sources that contribute to the uncertainty of these exposure-related quantities, some of which are unique to the low energy x-ray spectrum produced by mammographic x-ray units. For each of these exposure-related quantities, the applicable error sources and their magnitudes vary, depending on the test equipment used to make the measurement, and whether or not relevant corrections have been applied. This study has identified and quantified a range of error sources that may be used to estimate the combined uncertainty of these exposure-related quantities, given the test equipment used and corrections applied. The uncertainty analysis uses methods described by the International Standards Organization's Guide to the Expression of Uncertainty in Measurement. Examples of how these error sources combine to give the uncertainty of the exposure-related quantities are presented. Using the best test equipment evaluated in this study, uncertainties of the four exposure-related quantities at the 95% confidence interval were found to be ±1.6% (half value layer), ±0.0008 (automatic exposure control reproducibility), ±2.3% (average glandular dose), and ±2.1% (radiation output rate). In some cases, using less precise test equipment or failing to apply corrections, resulted in uncertainties more than double in magnitude

  6. Dental X-ray diagnostic facility with means to choose the time of exposure

    Energy Technology Data Exchange (ETDEWEB)

    Krause, H; Grassme, U

    1978-02-16

    Equipment for dental X-ray diagnostics with automatic exposure control. In the patient's mouth there is arranged a film carrier containing in a pocket a dental X-ray film. A detector-transmitter assembly touches the pocket. It reacts to the density of the film and wireless transmits a signal to an antenna. This antenna is connected to a receiver shutting off the high voltage of the X-ray tube by means of a circuit if a desired dose value is reached. The detector-transmitter unit is an integrated component. It has got a luminescent layer with a light-sensitive detector or a detector directly sensitive to X-rays.

  7. Analysis of Patients' X-ray Exposure in 146 Percutaneous Radiologic Gastrostomies.

    Science.gov (United States)

    Petersen, Tim-Ole; Reinhardt, Martin; Fuchs, Jochen; Gosch, Dieter; Surov, Alexey; Stumpp, Patrick; Kahn, Thomas; Moche, Michael

    2017-09-01

    Purpose  Analysis of patient´s X-ray exposure during percutaneous radiologic gastrostomies (PRG) in a larger population. Materials and Methods  Data of primary successful PRG-procedures, performed between 2004 and 2015 in 146 patients, were analyzed regarding the exposition to X-ray. Dose-area-product (DAP), dose-length-product (DLP) respectively, and fluoroscopy time (FT) were correlated with the used x-ray systems (Flatpanel Detector (FD) vs. Image Itensifier (BV)) and the necessity for periprocedural placement of a nasogastric tube. Additionally, the effective X-ray dose for PRG placement using fluoroscopy (DL), computed tomography (CT), and cone beam CT (CBCT) was estimated using a conversion factor. Results  The median DFP of PRG-placements under fluoroscopy was 163 cGy*cm 2 (flat panel detector systems: 155 cGy*cm 2 ; X-ray image intensifier: 175 cGy*cm 2 ). The median DLZ was 2.2 min. Intraprocedural placement of a naso- or orogastric probe (n = 68) resulted in a significant prolongation of the median DLZ to 2.5 min versus 2 min in patients with an already existing probe. In addition, dose values were analyzed in smaller samples of patients in which the PRG was placed under CBCT (n = 7, median DFP = 2635 cGy*cm 2 ), or using CT (n = 4, median DLP = 657 mGy*cm). Estimates of the median DFP and DLP showed effective doses of 0.3 mSv for DL-assisted placements (flat panel detector 0.3 mSv, X-ray image converter 0.4 mSv), 7.9 mSv using a CBCT - flat detector, and 9.9 mSv using CT. This corresponds to a factor 26 of DL versus CBCT, or a factor 33 of DL versus CT. Conclusion  In order to minimize X-ray exposure during PRG-procedures for patients and staff, fluoroscopically-guided interventions should employ flat detector systems with short transmittance sequences in low dose mode and with slow image frequency. Series recordings can be dispensed with. The intraprocedural placement of a naso- or orogastric probe

  8. X-ray diagnostics of female genitals in child age

    International Nuclear Information System (INIS)

    Willich, E.; Benz-Bohm, G.; Koeln Univ.

    1982-01-01

    The experiences of special X-ray diagnostics of female genitals are described, that were made in 41 children within a period of 12 years. The superiority of the X-ray-technique arises from the impossibility of the manual examination in newborn and infants and the avoidance of diagnostic techniques like laparoscopy or laparotomy. All the examination techniques are described. In intersexualmarked patients the discrimination into six types after Shopfner is preferred. Malformations and tumours are dealt with briefly. The relations between skeleton and female genitals are pointed out at the example of the gonadal dysgenesis. (orig.) [de

  9. Combined exposure of ELF magnetic fields and X-rays increased mutant yields compared with X-rays alone in pTN89 plasmids

    International Nuclear Information System (INIS)

    Koyama, Shin; Nakahara, Takehisa; Sakurai, Tomonori; Komatsubara, Yoshiki; Miyakoshi, Junji; Isozumi, Yasuhito

    2005-01-01

    We have examined mutations in the supF gene carried by pTN89 plasmids in Escherichia coli (E. coli) to examine the effects of extremely low frequency magnetic fields (ELFMFs) and/or X-rays to the plasmids. The plasmids were subjected to sham exposure or exposed to an ELFMF (5 mT), with or without X-ray irradiation (10 Gy). For the combined treatments, exposure to the ELFMF was immediately before or after X-ray irradiation. The mutant fractions were 0.94 x 10 -5 for X-rays alone, 1.58 x 10 -5 for an ELFMF followed by X-rays, and 3.64 x 10 -5 for X-rays followed by an ELFMF. Increased mutant fraction was not detected following exposure to a magnetic field alone, or after sham exposure. The mutant fraction for X-rays followed by an ELFMF was significantly higher than those of other treatments. Sequence analysis of the supF mutant plasmids revealed that base substitutions were dominant on exposure to X-rays alone and X-rays plus an ELFMF. Several types of deletions were detected in only the combined treatments, but not with X-rays alone. We could not find any mutant colonies in sham irradiated and an ELFMF alone treatment, but exposure to ELFMFs immediately before or after X-ray irradiation may enhance the mutations. Our results indicate that an ELFMF increases mutation and alters the spectrum of mutations. (author)

  10. Deformation and stress in PMMA during hard X-ray exposure for deep lithography

    International Nuclear Information System (INIS)

    Moldovan, N.

    1999-01-01

    The availability of high-energy, high-flux, collimated synchrotrons radiation has extended the application of deep X-ray lithography (DXRL) to thickness values of the PMMA resist of several millimeters. Some of the most severe limitations come from plastic deformation, stress, and cracks induced in PMMA during exposure and development. We have observed and characterized these phenomena quantitatively. Profilometry measurements revealed that the PMMA is subjected either to local shrinkage or to expansion, while compression and expansion evolve over time. Due to material loss and crosslinking, the material undergoes a shrinkage, while the radiation-induced decomposition generates gases expanding the polymer matrix. The overall dynamics of the material microrelief and stress during and after the exposure depend on the balance between compaction and outgassing. These depend in turn on the exposure conditions (spectrum; dose, dose rate, seaming, temperature), post-exposure storage conditions, PMMA material properties and thickness, and also on the size and geometry of the exposed patterns

  11. Calculation on cosmic-ray muon exposure rate in non-walled concrete buildings

    International Nuclear Information System (INIS)

    Fujitaka, Kazunobu; Abe, Siro

    1984-01-01

    Computer simulations on the exposure indoors from cosmic ray muons were practiced in the framework of non-scattering and non-cascade assumptions. The model buildings were two-dimensional, rectangular, and were made of a normal concrete. A stratified structure was assumed in each building, where no mezzanine was considered. Walls were not taken into account yet. The distributions of the exposure rates in 26-story buildings were illustrated in contour maps for various sets of parameters. All of them gave basically archlike patterns. Analyses of the results showed that the exposure rate is affected most largely by the floor board thickness. The ceiling height would be an insignificant factor for short buildings. The min/max ratio of the muon exposure rate in a moderate size building was estimated to be more than 0.7. (author)

  12. Micronucleus induction by repeated exposure of diagnostic X-ray on oral buccal mucosa

    International Nuclear Information System (INIS)

    Lohith Tejashvi, K.; Suchetha Kumari, N.; Shetty, Shishir Ram

    2012-01-01

    Radiography is the important diagnostic tools essential for diagnosis and planning of orthodontic treatment. X-ray is ionizing radiation which showed various effects include breaking the bond of biological molecules, inducing loss of ability of cell death, increases nuclear alterations. Micronuclei - x000D - (MN) are small chromatin bodies that appear in the cytoplasm by the - x000D - condensation of acrocentric chromosomal fragments or by whole chromosomes. This - x000D - is a sensitive indicator of genetic damage. - x000D - x000D - . To evaluate micronucleus induction by repeated exposure of diagnostic X-ray on human buccal cell. Methods: 25 patients who visiting to ABSMIDS, Department of Oral medicine and Radiology for dental checkup exposed to diagnostic X-ray more than 4 times have been selected for this study. The buccal cell for analysis was collected from the cheek mucosa by means of gentle scraping of epithelial using ice-cream sticks and placed in Buffer saline. This sample was smeared on glass slide and then fixed in methanol:glacial acetic acid (3:1). Air dried and stained with Giemsa for 15-25 minutes. Then 250 cells in each slides were analyzed under microscope and frequency of micronucleus was scored (n=4). Repeated X-ray exposed cells showed micronucleus (1.25%) and nuclear alteration (2.3%) compare to the control. Repeated X-ray exposure leads to induces detectable number of micronucleus and nuclear alterations. (author)

  13. Gamma-ray spectra from the age of the dinosaurs

    International Nuclear Information System (INIS)

    Johnson, M.W.

    1994-01-01

    Gamma-ray spectroscopy has been tested as a technique for assisting in the excavation of paleontological sites in the Morrison Formation of western New Mexico. Excavation of these sites is difficult, owing to remoteness and to environmental concerns that militate against wholesale removal of overburden. Various researchers have used remote-sensing techniques to attempt to locate sub-surface bone near known, exposed fossils, thereby to confine excavation to areas where success in finding bone is most likely. Bones accumulate uranium from surrounding rock during fossilization; accordingly, in-situ gamma-ray spectroscopy might serve to locate bone, by detecting the 609- and 1764-keV gamma rays from uranium daughters. Because of the high uranium content of fossils in the Morrison Formation, calculations suggest the feasibility of locating bone despite the presence of several cm of rock and soil overburden. Investigations at several sites with fossils of large sauropods have revealed increased count rates for the key gamma rays near exposed bone, possibly implying the presence of additional fossils beneath the surface of the ground. However, attempts to use spectroscopy inside shafts drilled into possible fossil-bearing rock have been less successful. Results are presented and prospects for additional work discussed

  14. A novel method of microneedle array fabrication using inclined deep x-ray exposure

    International Nuclear Information System (INIS)

    Moon, Sang Jun; Jin, Chun Yan; Lee, Seung S

    2006-01-01

    We report a novel fabrication method for the microneedle array with a 3-dimensional feature and its replication method; 'Hot-pressing' process with bio-compatible material, PLLA (Poly L-LActide). Using inclined deep X-ray exposure technique, we fabricate a band type microneedle array with a single body on the same material basement. Since the single body feature does not make adhesion problem with the microneedle shank and basement during peel-off step of a mold, the PMMA (Poly-Methyl-MethAcrylate) microneedle array mold insert can be used for mold process which is used with the soft material mold, PDMS (Poly-Di- Methyl-Siloxane). The side inclined deep X-ray exposure also makes complex 3-dimensional features by the regions which are not exposed during twice successive exposure steps. In addition, the successive exposure does not need an additional mask alignment after the first side exposure. The fabricated band type microneedle array mold inserts are assembled for large area patch type out-of-plane microneedle array. The bio-compatible microneedle array can be fabricated to the laboratory scale mass production by the single body PMMA mold insert and 'Hot-pressing' process

  15. A novel method of microneedle array fabrication using inclined deep x-ray exposure

    Energy Technology Data Exchange (ETDEWEB)

    Moon, Sang Jun; Jin, Chun Yan; Lee, Seung S [Department of Mechanical Engineering, Korea Advanced Institute of Science and Technology (KAIST), 373-1, Guseong-dong, Yuseong-dong, Daejeon (Korea, Republic of)

    2006-04-01

    We report a novel fabrication method for the microneedle array with a 3-dimensional feature and its replication method; 'Hot-pressing' process with bio-compatible material, PLLA (Poly L-LActide). Using inclined deep X-ray exposure technique, we fabricate a band type microneedle array with a single body on the same material basement. Since the single body feature does not make adhesion problem with the microneedle shank and basement during peel-off step of a mold, the PMMA (Poly-Methyl-MethAcrylate) microneedle array mold insert can be used for mold process which is used with the soft material mold, PDMS (Poly-Di- Methyl-Siloxane). The side inclined deep X-ray exposure also makes complex 3-dimensional features by the regions which are not exposed during twice successive exposure steps. In addition, the successive exposure does not need an additional mask alignment after the first side exposure. The fabricated band type microneedle array mold inserts are assembled for large area patch type out-of-plane microneedle array. The bio-compatible microneedle array can be fabricated to the laboratory scale mass production by the single body PMMA mold insert and 'Hot-pressing' process.

  16. X-ray exposure in utero and school performance: a population-based study of X-ray pelvimetry

    International Nuclear Information System (INIS)

    Nordenskjöld, A.C.; Palme, M.; Kaijser, M.

    2015-01-01

    Aim: To investigate the association between exposure to ionising radiation from pelvimetric examinations in utero and school performance. Material and methods: This was a population-based cohort study comprising 46,066 children born in the county of Östergötland, Sweden, from 1980 through 1990. Through record linkage between Swedish registers, children exposed in utero to X-ray pelvimetry examination were compared to other children born in the same county during the study period, as well as to their unexposed siblings. Outcome variable was primary school grades, expressed in centiles and calculated through linear regression. Results: In the univariate analysis, children exposed to X-ray pelvimetry in utero had higher school grades compared to unexposed children (point estimate 3 centiles, 95% confidence interval [CI]: 1.5 to 4.6). When sex, mother's education and income, birth order, and birth position were included in the analysis; however, the difference was reduced and the association was no longer statistically significant (PE 1.4, 95% CI: –0.1 to 2.8). Comparing exposed children with their siblings showed no statistical difference in univariate analysis or in multivariate analysis. Conclusion: No suggestion was found of a negative effect on school performance from in utero exposure of diagnostic X-ray pelvimetry. -- Highlights: •Pelvimetric examinations expose fetus to low levels of radiation. •No detectable effect on childrens final primary school grades from pelvimetric examinations. •Pelvimetric examinations is a safe procedure for the fetus regarding shool performance

  17. Exposure reduction in general dental practice using digital x-ray imaging system for intraoral radiography with additional x-ray beam filter

    International Nuclear Information System (INIS)

    Shibuya, Hitoshi; Mori, Toshimichi; Hayakawa, Yoshihiko; Kuroyanagi, Kinya; Ota, Yoshiko

    1997-01-01

    To measure exposure reduction in general dental practice using digital x-ray imaging systems for intraoral radiography with additional x-ray beam filter. Two digital x-ray imaging systems, Pana Digital (Pana-Heraus Dental) and CDR (Schick Technologies), were applied for intraoral radiography in general dental practice. Due to the high sensitivity to x-rays, additional x-ray beam filters for output reduction were used for examination. An Orex W II (Osada Electric Industry) x-ray generator was operated at 60 kVp, 7 mA. X-ray output (air-kerma; Gy) necessary for obtaining clinically acceptable images was measured at 0 to 20 cm in 5 cm steps from the cone tip using an ionizing chamber type 660 (Nuclear Associates) and compared with those for Ektaspeed Plus film (Eastman Kodak). The Pana Digital system was used with the optional filter supplied by Pana-Heraus Dental which reduced the output to 38%. The exposure necessary to obtain clinically acceptable images was only 40% of that for the film. The CDR system was used with the Dental X-ray Beam Filter Kit (Eastman Kodak) which reduced the x-ray output to 30%. The exposure necessary to obtain clinically acceptable images was only 20% of that for the film. The two digital x-ray imaging systems, Pana Digital and CDR, provided large dose savings (60-80%) compared with Ektaspeed Plus film when applied for intraoral radiography in general dental practice. (author)

  18. Prenatal exposure to selective serotonin reuptake inhibitors and childhood overweight at 7 years of age

    DEFF Research Database (Denmark)

    Grzeskowiak, Luke E; Gilbert, Andrew L; Sørensen, Thorkild

    2013-01-01

    To investigate a possible association between prenatal selective serotonin reuptake inhibitor (SSRI) exposure and childhood overweight at 7 years of age.......To investigate a possible association between prenatal selective serotonin reuptake inhibitor (SSRI) exposure and childhood overweight at 7 years of age....

  19. An Industrial Radipgraphy Exposure Device Based on Measurement of Transmitted Gamma-Ray Intensity

    International Nuclear Information System (INIS)

    Polee, C.; Chankow, N.; Srisatit, S.; Thong-Aram, D.

    2014-01-01

    In film radiography, underexposure and overexposure may happen particularly when lacking knowledge of specimen material and hollowness. This paper describes a method and a device for determining exposure in industrial gamma-ray radiography based on quick measurement of transmitted gamma-ray intensity with a D3372 Hamamatsu small GM tube. Application software is developed for Android mobile phone to remotely control the device and to display the counting data via Bluetooth. Prior to placing film, the device is placed behind the specimen to be radiographed to determine the exposure time from the transmitted intensity which is independent on source activity, source-to-film distance, specimen thickness and kind of material. The developed technique and device make radiographic process economic, convenient and more reliable.

  20. Exposure assessment of neonates in israel to x-ray radiation during hospitalization at neonatal intensive care unit

    International Nuclear Information System (INIS)

    Datz, H.

    2005-03-01

    Nowadays nearly 10% of all births in western countries are premature. In the last decade, there has been an increase of 45% in the number of neonates that were born in Israel. At the same time, the survival of neonates, especially those with very low birth weight, VLBW, (less than 1,500 gr), has increased dramatically. Diagnostic radiology plays an important role in the assessment and treatment of neonates requiring intensive care. During their prolonged and complex hospitalization, these infants are exposed to multiple radiographic examinations involving X-ray radiation. The extent of the examinations that the infant undergoes depends on its birth weight, gestational age and its medical problems, where most of the treatment effort is focused especially on VLBW neonates. Most of the diagnostic X-ray examinations taken during the hospitalization of neonates in the neonatal intensive care unit (NICU) consist of imaging of the respiratory and gastrointestinal systems, namely, the chest and abdomen. The imaging process is done using mobile X-ray units located at the NICUs. Due to their long hospitalization periods and complex medical condition, all neonates, and neonates with VLBW in particular, are exposed to a much higher level of diagnostic radiation, compared to normal newborns. The goal of this research was to assess the extent of the exposure of neonates in Israel to X-ray radiation during their hospitalization at the neonatal intensive care unit. Five NICUs, located at different geographical zones in Israel and treating 20% of all newborns in Israel every year, participated in this research. The research was conducted in three phases: Phase I: Collection of information on radiographic techniques and exposure parameters (e.g. kV, mAs, focus to skin distance (FSD), examination borders). 499 X-ray examinations (from 157 neonates) were evaluated for necessary and unnecessary exposure of the neonate's organs to X-ray radiation during these examinations. Phase II

  1. Occupational exposure of medical staff due to diagnostic X-ray examinations in veterinary medicine

    Energy Technology Data Exchange (ETDEWEB)

    Mergel, E.; Feige, S. [Gesellschaft fuer Anlagen- und Reaktorsicherheit mbH (GRS) (Germany); Haeusler, U. [Bundesamt fuer Strahlenschutz (BfS), Salzgitter (Germany)

    2007-07-01

    The implementation of the Council directive 96/29 EURATOM and the corresponding national Radiation Protection Ordinance and the X-ray Protection Ordinance coming subsequently into effect led to a changed situation regarding the occupational radiation protection in the medical sector. To reduce the occupational exposure of veterinarians and assisting staff in veterinary radiography is particularly challenging as, in opposite to human radiological examination, the presence of staff is indispensable to restrain the patient. Beyond that the relevant literature reports about too high and/or about unnecessary radiation exposures. To gain a comprehensive knowledge upon the possible exposure of involved staff, the variety of typical examination methods in veterinary clinics and at practitioners had been investigated during the daily routine. Dose measurements were performed for different employees during the examinations taking into account several places of exposure (lens, thyroid, chest, hand, gonad, and feet). Veterinary X-ray diagnostic examinations for pets as well as in equine radiography had been accounted for this study. In total, 101 examination methods, 4.484 accompanied examinations and 53.892 single dose readings resulted in a reliable statistical base to set up a 'Job-Exposure-Matrix' allowing the dose assessment for a variable number and kind of examinations. The 'Job-Exposure-Matrix' is believed to be a useful tool for optimization of occupational radiation exposure of veterinarians by appraising the height of a possible dose, forcing a review of the status quo and triggering the improvement of personal protection by establishing adequate measures. (orig.)

  2. Cytological evidence of chromosomal rearrangement in the second meiotic division after exposure to X-rays

    Energy Technology Data Exchange (ETDEWEB)

    Szemere, G. (Orvostudomanyi Egyetem, Szeged (Hungary). Orvosbiologiai Intezet)

    1982-01-01

    Metaphase II cells with unequal dyad-arms and obvious X/autosomal rearrangements were found after an exposure to X-rays (2 Gy) of male mice at different stages of meiosis (pachytene, diplotene and diakinesis) with a frequency of 0.2, 1.26 and 0.6%, respectively, giving a direct cytological evidence of structural chromosomal rearrangements in metaphase II cells, partly with autosomal and partly with X/autosomal partners.

  3. Cytological evidence of chromosomal rearrangement in the second meiotic division after exposure to X-rays

    International Nuclear Information System (INIS)

    Szemere, G.

    1982-01-01

    Metaphase II cells with unequal dyad-arms and obvious X/autosomal rearrangements were found after an exposure to X-rays (2 Gy) of male mice at different stages of meiosis (pachytene, diplotene and diakinesis) with a frequency of 0.2, 1.26 and 0.6%, respectively, giving a direct cytological evidence of structural chromosomal rearrangements in metaphase II cells, partly with autosomal and partly with X/autosomal partners. (author)

  4. Investigation of Deuterium Loaded Materials Subject to X-Ray Exposure

    Science.gov (United States)

    Benyo, Theresa L.; Steinetz, Bruce M.; Hendricks, Robert C.; Martin, Richard E.; Forsley, Lawrence P.; Daniels, Christopher C.; Chait, Arnon; Pines, Vladimir; Pines, Marianna; Penney, Nicholas; hide

    2017-01-01

    Results are presented from an exploratory study involving x-ray irradiation of select deuterated materials. Titanium deuteride plus deuterated polyethylene, deuterated polyethylene alone, and for control, hydrogen-based polyethylene samples and nondeuterated titanium samples were exposed to x-ray irradiation. These samples were exposed to various energy levels from 65 to 280 kV with prescribed electron flux from 500 to 9000 µA impinging on a tungsten braking target, with total exposure times ranging from 55 to 280 min. Gamma activity was measured using a high-purity germanium (HPGe) detector, and for all samples no gamma activity above background was detected. Alpha and beta activities were measured using a gas proportional counter, and for select samples beta activity was measured with a liquid scintillator spectrometer. The majority of the deuterated materials subjected to the microfocus x-ray irradiation exhibited postexposure beta activity above background and several showed short-lived alpha activity. The HPE and nondeuterated titanium control samples exposed to the x-ray irradiation showed no postexposure alpha or beta activities above background. Several of the samples (SL10A, SL16, SL17A) showed beta activity above background with a greater than 4s confidence level, months after exposure. Portions of SL10A, SL16, and SL17A samples were also scanned using a beta scintillator and found to have beta activity in the tritium energy band, continuing without noticeable decay for over 12 months. Beta scintillation investigation of as-received materials (before x-ray exposure) showed no beta activity in the tritium energy band, indicating the beta emitters were not in the starting materials.

  5. Digital image acquisition in the X-ray diagnostics. Its influence on the patients' exposure

    International Nuclear Information System (INIS)

    Hoberg, Bernd; Voigt, Stefan

    2012-01-01

    Radiation exposure in the classical X-ray diagnostics was continuously reduced during the past years. The annual report 2009 of the Bundesamt fuer Strahlenschutz (BfS) shows that 46% of the radiological examinations in Germany concern the skeleton, the lungs and the digestive and urogenital tract. The respective radiation dose is only 20% of the total dose of the public from X-ray diagnostic measures. Considering computerized tomography, angiography and interventional radiology, that amount to about 10% of the radiological examinations, their dose percentage reaches about 80%. Therefore, the emphasis of modern radiation protection has to be targeted to digital techniques in the future X-ray diagnostics. The authors describe digital detectors, direct and indirect digitalized image receivers, flat-panel detectors and dynamic detectors.

  6. Update of diagnostic medical and dental x-ray exposures in Romania

    Energy Technology Data Exchange (ETDEWEB)

    Sorop, Ioana; Mossang, Daniela; Dadulescu, Elena [Radiation Hygiene Laboratory of Public Health Authority Dolj, 2, Constantin Lecca Street, Craiova (Romania); Iacob, Mihai Radu [University ' Alexandru Ioan Cuza' , 11, Carol I Street, 700506, Iasi (Romania); Iacob, Olga [Institute of Public Health, 14, Victor Babes Street, 700465 Iasi (Romania)], E-mail: danamossang@sanpubdj.ro

    2008-12-15

    This national study, the third in the last 15 years, updates the magnitude of medical radiation exposure from conventional x-ray examinations, in order to optimise the radiological protection to the population in a cost-effective manner. Effective doses from diagnostic radiology were estimated for adult and paediatric patients undergoing the 20 most important types of x-ray examination. Data were collected from 179 x-ray departments, selected by their annual workload, throughout the country. Estimates were made using two dosimetric quantities: entrance surface dose, derived from the absorbed dose in air measured by simulation of radiographic examinations, and dose-area product, measured during fluoroscopic examinations performed on adult and paediatric patients. Conversion coefficients to effective dose of the UK National Radiological Protection Board (NRPB) have been used in all calculations. The effective dose per patient from all medical x-ray examinations was 0.74 mSv and the resulting annual collective effective dose was 6930 man Sv, with annual effective dose per caput of 0.33 mSv. The current size of population exposure from diagnostic radiology is lower than the previous one by 40%, but could be about 30% higher by taking into account the estimated contribution from computed tomography (CT) procedures.

  7. Dietary calcium intake and sunlight exposure among children aged ...

    African Journals Online (AJOL)

    Nutritional rickets can be caused by either or both calcium and vitamin D deficiencies, and can frequently occur in Africa. In Ethiopia, limited evidence exists regarding the calcium intake of children and their sunlight exposure practices. The purpose of this study was to assess information regarding dietary calcium intake and ...

  8. EXPOSURE OF CHILDREN 4 TO 6 MONTHS OF AGE TO ...

    African Journals Online (AJOL)

    MARY OBADE

    1PhD Student, Maseno University, P.O Box 3803-40100, Kisumu, Kenya ... Contamination of foods by aflatoxins is a global health problem in both ... vulnerable to effects of aflatoxin exposure compared to adults. ... Aflatoxin poisoning resulting ...

  9. Optimization of exposure factors for X-ray radiography non-destructive testing of pearl oyster

    Science.gov (United States)

    Susilo; Yulianti, I.; Addawiyah, A.; Setiawan, R.

    2018-03-01

    One of the processes in pearl oyster cultivation is detecting the pearl nucleus to gain information whether the pearl nucleus is still attached in the shell or vomited. The common tool used to detect pearl nucleus is an X-ray machine. However, an X-ray machine has a drawback that is the energy used is higher than that used by digital radiography. The high energy make the resulted image is difficult to be analysed. One of the advantages of digital radiography is the energy used can be adjusted so that the resulted image can be analysed easily. To obtain a high quality of pearl image using digital radiography, the exposure factors should be optimized. In this work, optimization was done by varying the voltage, current, and exposure time. Then, the radiography images were analysed using Contrast to Noise Ratio (CNR). From the analysis, it can be determined that the optimum exposure factors are 60 kV of voltage, 16 mA of current, and 0.125 s of exposure time which result in CNR of 5.71.

  10. A practical exposure-equivalent metric for instrumentation noise in x-ray imaging systems

    International Nuclear Information System (INIS)

    Yadava, G K; Kuhls-Gilcrist, A T; Rudin, S; Patel, V K; Hoffmann, K R; Bednarek, D R

    2008-01-01

    The performance of high-sensitivity x-ray imagers may be limited by additive instrumentation noise rather than by quantum noise when operated at the low exposure rates used in fluoroscopic procedures. The equipment-invasive instrumentation noise measures (in terms of electrons) are generally difficult to make and are potentially not as helpful in clinical practice as would be a direct radiological representation of such noise that may be determined in the field. In this work, we define a clinically relevant representation for instrumentation noise in terms of noise-equivalent detector entrance exposure, termed the instrumentation noise-equivalent exposure (INEE), which can be determined through experimental measurements of noise-variance or signal-to-noise ratio (SNR). The INEE was measured for various detectors, thus demonstrating its usefulness in terms of providing information about the effective operating range of the various detectors. A simulation study is presented to demonstrate the robustness of this metric against post-processing, and its dependence on inherent detector blur. These studies suggest that the INEE may be a practical gauge to determine and compare the range of quantum-limited performance for clinical x-ray detectors of different design, with the implication that detector performance at exposures below the INEE will be instrumentation-noise limited rather than quantum-noise limited

  11. Age at exposure and attained age variations of cancer risk in the Japanese A-bomb and radiotherapy cohorts

    Energy Technology Data Exchange (ETDEWEB)

    Schneider, Uwe, E-mail: uwe.schneider@uzh.ch [Institute of Physics, Science Faculty, University of Zürich, Zürich 8057, Switzerland and Radiotherapy Hirslanden, Uwe Schneider Institute of Radiotherapy, Witellikerstr. 40, Zürich 8032 (Switzerland); Walsh, Linda [Institute of Physics, Science Faculty, University of Zürich, Zürich 8057, Switzerland and BfS - Federal Office for Radiation Protection, Radiation Protection and Health, Neuherberg 85764 (Germany)

    2015-08-15

    Purpose: Phenomenological risk models for radiation-induced cancer are frequently applied to estimate the risk of radiation-induced cancers at radiotherapy doses. Such models often include the effect modification, of the main risk to radiation dose response, by age at exposure and attained age. The aim of this paper is to compare the patterns in risk effect modification by age, between models obtained from the Japanese atomic-bomb (A-bomb) survivor data and models for cancer risks previously reported for radiotherapy patients. Patterns in risk effect modification by age from the epidemiological studies of radiotherapy patients were also used to refine and extend the risk effect modification by age obtained from the A-bomb survivor data, so that more universal models can be presented here. Methods: Simple log-linear and power functions of age for the risk effect modification applied in models of the A-bomb survivor data are compared to risks from epidemiological studies of second cancers after radiotherapy. These functions of age were also refined and fitted to radiotherapy risks. The resulting age models provide a refined and extended functional dependence of risk with age at exposure and attained age especially beyond 40 and 65 yr, respectively, and provide a better representation than the currently available simple age functions. Results: It was found that the A-bomb models predict risk similarly to the outcomes of testicular cancer survivors. The survivors of Hodgkin’s disease show steeper variations of risk with both age at exposure and attained age. The extended models predict solid cancer risk increase as a function of age at exposure beyond 40 yr and the risk decrease as a function of attained age beyond 65 yr better than the simple models. Conclusions: The standard functions for risk effect modification by age, based on the A-bomb survivor data, predict second cancer risk in radiotherapy patients for ages at exposure prior to 40 yr and attained ages

  12. Age at exposure and attained age variations of cancer risk in the Japanese A-bomb and radiotherapy cohorts.

    Science.gov (United States)

    Schneider, Uwe; Walsh, Linda

    2015-08-01

    Phenomenological risk models for radiation-induced cancer are frequently applied to estimate the risk of radiation-induced cancers at radiotherapy doses. Such models often include the effect modification, of the main risk to radiation dose response, by age at exposure and attained age. The aim of this paper is to compare the patterns in risk effect modification by age, between models obtained from the Japanese atomic-bomb (A-bomb) survivor data and models for cancer risks previously reported for radiotherapy patients. Patterns in risk effect modification by age from the epidemiological studies of radiotherapy patients were also used to refine and extend the risk effect modification by age obtained from the A-bomb survivor data, so that more universal models can be presented here. Simple log-linear and power functions of age for the risk effect modification applied in models of the A-bomb survivor data are compared to risks from epidemiological studies of second cancers after radiotherapy. These functions of age were also refined and fitted to radiotherapy risks. The resulting age models provide a refined and extended functional dependence of risk with age at exposure and attained age especially beyond 40 and 65 yr, respectively, and provide a better representation than the currently available simple age functions. It was found that the A-bomb models predict risk similarly to the outcomes of testicular cancer survivors. The survivors of Hodgkin's disease show steeper variations of risk with both age at exposure and attained age. The extended models predict solid cancer risk increase as a function of age at exposure beyond 40 yr and the risk decrease as a function of attained age beyond 65 yr better than the simple models. The standard functions for risk effect modification by age, based on the A-bomb survivor data, predict second cancer risk in radiotherapy patients for ages at exposure prior to 40 yr and attained ages before 55 yr reasonably well. However, for

  13. Video x-ray progressive scanning: new technique for decreasing x-ray exposure without decreasing image quality during cardiac catheterization

    International Nuclear Information System (INIS)

    Holmes, D.R. Jr.; Bove, A.A.; Wondrow, M.A.; Gray, J.E.

    1986-01-01

    A newly developed video x-ray progressive scanning system improves image quality, decreases radiation exposure, and can be added to any pulsed fluoroscopic x-ray system using a video display without major system modifications. With use of progressive video scanning, the radiation entrance exposure rate measured with a vascular phantom was decreased by 32 to 53% in comparison with a conventional fluoroscopic x-ray system. In addition to this substantial decrease in radiation exposure, the quality of the image was improved because of less motion blur and artifact. Progressive video scanning has the potential for widespread application to all pulsed fluoroscopic x-ray systems. Use of this technique should make cardiac catheterization procedures and all other fluoroscopic procedures safer for the patient and the involved medical and paramedical staff

  14. Optimized control of X-ray exposure and image noise using a particular multislice CT scanner

    International Nuclear Information System (INIS)

    Yamamoto, Shuji; Suzuki, Masahiro; Kakinuma, Ryutaro; Moriyama, Noriyuki; Koyama, Yoshihiro; Nagasawa, Hirofumi

    2008-01-01

    Patient dose reduction in computed tomography (CT) always results in a trade off between radiation exposure and image quality. There are few reports that estimate the relationship between image quality and X-ray exposure in CT examinations as one optimal index. The purpose of this study was to determine the optimal parameter settings enabling a low radiation exposure without compromising image quality using a particular 4-row multislice CT (MSCT) scanner (Aquilion VZ 4-slice CT scanner, Toshiba Medical Systems Corporation, Otawara, Tochigi, Japan). Normalized dose divided by image noise for helical pitches (nDNR: normalized dose to noise ratio) were calculated in consideration of beam collimation and tube current-time product. Optimal tube current-time product was calculated using the nDNR for the helical pitches based on user-defined standards of quality of the CT image. As a result, the nDNR proved to be well-supported to decrease the patient exposure in various exposure conditions of MSCT scans; however, the dose and image noise did not show a linear relation to the helical pitch. In conclusion, nDNR can be applied to patient dose reduction while keeping an acceptable image quality using a particular 4-row MSCT scanner. (author)

  15. Variations with time and age in the relative risks of solid cancer incidence after radiation exposure

    International Nuclear Information System (INIS)

    Little, M.P.; Muirhead, C.R.; de Vathaire, F.; Charles, M.W.

    1997-01-01

    The Japanese atomic bomb survivor cancer incidence dataset and data on five groups exposed to radiation for medical reasons in childhood are analysed and evidence found for a reduction in the radiation-induced relative risk of cancers other than leukaemia with increasing time since exposure and age at exposure. The rate of the reductions in relative risk with time since exposure are not significantly different for those exposed in childhood and for those exposed in adulthood, if adjustment is made for the effects on the relative risk of age at exposure. For those irradiated in childhood, there is a statistically significant annual reduction of 5.8% (95% Cl 2.8, 8.9) in excess relative risk, and there are no strong indications of inter-cohort heterogeniety in the speed of reduction of relative risk. After adjustment for the effects of age at exposure, there is a significant annual reduction of 3.6% (95% Cl 1.6, 5.6) in excess relative risk in all age-at-exposure groups. There are significant reductions of 5.2% (95% Cl 3.7, 6.8) in excess relative risk per year of age at exposure. There are statistically significant (P = 0.04) interactions between the exponential adjustments to the excess relative risk for age at exposure and time since exposure in the Japanese data, but no indications (P = 0.38) of such interactions when powers of time since exposure and attained age are used to adjust the excess relative risk, so that the fit of the model with power adjustments is to be preferred to that of the model with exponential adjustments. (author)

  16. Device for measuring the exposure time in dental X-ray - Cronox

    International Nuclear Information System (INIS)

    Menezes, Claudio J.M.; Santos, Luiz A.P. dos

    2009-01-01

    The Centro Regional de Ciencias Nucleares do Nordeste (CRCN-NE) developed a test device for monitoring the X-ray beam in dental equipment to its application in quality control programs. This device, called Odontologic Dosimetric Card (CDO of Cartao Dosimetrico Odontologico in Portuguese) uses thermoluminescent dosimeters (TLD) for the measurement of some parameters of the X-ray beam as the entrance surface dose, the peak tension and half value layer (HVL). Radiographic films record the size of the radiation field. However, the TLD does not allow the assessment of exposure time, a parameter that complements the requirements of the Diretrizes de Protecao Radiologica em Radiodiagnostico Medico e Odontologico of Department of Health in Brazil for such equipment. Thus was developed a system based on sensitivity to ionizing radiation of phototransistors for measurement of exposure time when a patient is put in a clinical dental radiography. The system, called CRONOX was sized to be inserted within the CDO. The results showed that the measuring error had developed for less than 3% when compared to reference values obtained with the Tektronix digital oscilloscope, TDS2022 model. The readings obtained with the CRONOX were also compared with the nominal values selected in the X-ray equipment and with the values measured with the instrument of trade PTW Diavolt Universal. The results showed that the measuring device developed showed a maximum deviation of 5.92% on the nominal value selected, while for the instrument of PTW was 17.86%. (author)

  17. Effects of embryonic and fetal exposure to x-ray, microwaves, and ultrasound

    International Nuclear Information System (INIS)

    Brent, R.L.

    1986-01-01

    Many professionals are unfamiliar with radiation biology or the quantitative nature of the risks. Frequently, microwave, ultrasound, and ionizing radiation risks are confused. Although it is impossible to prove no risk for any environmental hazard, it appears that exposure to microwave radiation below the maximal permissible levels present no measurable risk to the embryo. Ultrasound exposure from diagnostic ultrasonographic imaging equipment also is quite innocuous. It is true that continued surveillance and research into potential risks of these low-level exposures should continue, but at present ultrasound not only improves obstetric care but also reduces the necessity of diagnostic x-ray procedures. In the field of ionizing radiation, we have as good a comprehension of the biologic effects and the quantitative maximum risks as of any other environmental hazard. Although the animal and human data support the conclusion that no increases in the incidence of gross congenital malformations, intrauterine growth retardation, or abortion will occur with exposures less than 5 rad, that does not mean that there are definitely no risks to the embryo exposed to lower doses of radiation. Whether there exists a linear or exponential dose-response relationship or a threshold exposure for genetic, carcinogenic, cell-depleting, and life-shortening effects has not been determined. In establishing maximum permissible levels for the embryo at low exposures, refer to Tables 4, 5, 6, 8, and 9. It is obvious that the risks of 1-rad or 5-rad acute exposure are far below the spontaneous risks of the developing embryo because 15 per cent of human embryos abort, 2.7 to 3.0 per cent of human embryos have major malformations, 4 per cent have intrauterine growth retardation, and 8 to 10 per cent have early- or late-onset genetic disease. 98 references

  18. Maternal age at Holocaust exposure and maternal PTSD independently influence urinary cortisol levels in adult offspring

    Directory of Open Access Journals (Sweden)

    Heather N Bader

    2014-07-01

    Full Text Available Background: Parental traumatization has been associated with increased risk for the expression of psychopathology in offspring, and maternal PTSD appears to increase the risk for the development of offspring PTSD. In this study, Holocaust-related maternal age of exposure and PTSD were evaluated for their association with offspring ambient cortisol and PTSD-associated symptom expression. Method: 95 Holocaust offspring and Jewish comparison subjects received diagnostic and psychological evaluations, and 24 hour urinary cortisol was assayed by RIA. Offspring completed the Parental PTSD Questionnaire to assess maternal PTSD status. Maternal Holocaust exposure was identified as having occurred in childhood, adolescence or adulthood and examined in relation to offspring psychobiology. Results: Urinary cortisol levels did not differ for Holocaust offspring and comparison subjects but differed significantly in offspring based on maternal age of exposure and maternal PTSD status. Increased maternal age of exposure and maternal PTSD were each associated with lower urinary cortisol in offspring, but did not exhibit a significant interaction. In addition, offspring PTSD-associated symptom severity increased with maternal age at exposure and PTSD diagnosis. A regression analysis of correlates of offspring cortisol indicated that both maternal age of exposure and maternal PTSD were significant predictors of lower offspring urinary cortisol, whereas childhood adversity and offspring PTSD symptoms were not. Conclusions: Offspring low cortisol and PTSD-associated symptom expression are related to maternal age of exposure, with the greatest effects associated with increased age at exposure. These effects are relatively independent of the negative consequences of being raised by a trauma survivor. These observations highlight the importance of maternal age of exposure in determining a psychobiology in offspring that is consistent with increased risk for stress

  19. Maternal Age at Holocaust Exposure and Maternal PTSD Independently Influence Urinary Cortisol Levels in Adult Offspring

    Science.gov (United States)

    Bader, Heather N.; Bierer, Linda M.; Lehrner, Amy; Makotkine, Iouri; Daskalakis, Nikolaos P.; Yehuda, Rachel

    2014-01-01

    Background: Parental traumatization has been associated with increased risk for the expression of psychopathology in offspring, and maternal posttraumatic stress disorder (PTSD) appears to increase the risk for the development of offspring PTSD. In this study, Holocaust-related maternal age of exposure and PTSD were evaluated for their association with offspring ambient cortisol and PTSD-associated symptom expression. Method: Ninety-five Holocaust offspring and Jewish comparison subjects received diagnostic and psychological evaluations, and 24 h urinary cortisol was assayed by RIA. Offspring completed the parental PTSD questionnaire to assess maternal PTSD status. Maternal Holocaust exposure was identified as having occurred in childhood, adolescence, or adulthood and examined in relation to offspring psychobiology. Results: Urinary cortisol levels did not differ for Holocaust offspring and comparison subjects but differed significantly in offspring based on maternal age of exposure and maternal PTSD status. Increased maternal age of exposure and maternal PTSD were each associated with lower urinary cortisol in offspring, but did not exhibit a significant interaction. In addition, offspring PTSD-associated symptom severity increased with maternal age at exposure and PTSD diagnosis. A regression analysis of correlates of offspring cortisol indicated that both maternal age of exposure and maternal PTSD were significant predictors of lower offspring urinary cortisol, whereas childhood adversity and offspring PTSD symptoms were not. Conclusion: Offspring low cortisol and PTSD-associated symptom expression are related to maternal age of exposure, with the greatest effects associated with increased age at exposure. These effects are relatively independent of the negative consequences of being raised by a trauma survivor. These observations highlight the importance of maternal age of exposure in determining a psychobiology in offspring that is consistent with increased

  20. Exposure to Low-Dose X-Ray Radiation Alters Bone Progenitor Cells and Bone Microarchitecture.

    Science.gov (United States)

    Lima, Florence; Swift, Joshua M; Greene, Elisabeth S; Allen, Matthew R; Cunningham, David A; Braby, Leslie A; Bloomfield, Susan A

    2017-10-01

    Exposure to high-dose ionizing radiation during medical treatment exerts well-documented deleterious effects on bone health, reducing bone density and contributing to bone growth retardation in young patients and spontaneous fracture in postmenopausal women. However, the majority of human radiation exposures occur in a much lower dose range than that used in the radiation oncology clinic. Furthermore, very few studies have examined the effects of low-dose ionizing radiation on bone integrity and results have been inconsistent. In this study, mice were irradiated with a total-body dose of 0.17, 0.5 or 1 Gy to quantify the early (day 3 postirradiation) and delayed (day 21 postirradiation) effects of radiation on bone microarchitecture and bone marrow stromal cells (BMSCs). Female BALBc mice (4 months old) were divided into four groups: irradiated (0.17, 0.5 and 1 Gy) and sham-irradiated controls (0 Gy). Micro-computed tomography analysis of distal femur trabecular bone from animals at day 21 after exposure to 1 Gy of X-ray radiation revealed a 21% smaller bone volume (BV/TV), 22% decrease in trabecular numbers (Tb.N) and 9% greater trabecular separation (Tb.Sp) compared to sham-irradiated controls (P X-rays, whereas osteoclastogenesis was enhanced. A better understanding of the effects of radiation on osteoprogenitor cell populations could lead to more effective therapeutic interventions that protect bone integrity for individuals exposed to low-dose ionizing radiation.

  1. Effect of medical x-ray exposure on subsequent reproductive outcomes in scoliosis patients

    International Nuclear Information System (INIS)

    Visscher, W.A.

    1987-01-01

    A retrospective cohort study was done which was designed to assess the effects of medical x-ray exposure on cancer incidence among scoliosis patients. Although the primary purpose of the study was to assess cancer incidence, a secondary goal was to investigate whether diagnostic x-ray exposure is related to adverse reproductive events in the female subjects. A series of case-control analyses were done which were designed to assess these effects. Radiation exposure was measured both by total films received and by an estimate of the number of films received and by an estimate of the number of films which involved ovarian irradiation. Radiation appeared to increase a woman's risk of any adverse event in the overall analysis and her risk of a premature or low birth weight infant in the separate analyses. Radiation did not appear to be related to spontaneous abortion, complications of pregnancy or delivery or birth defects, although the results of the pregnancy complications analysis was suggestive

  2. A survey of medical exposure during X-ray diagnosis in Aomori

    International Nuclear Information System (INIS)

    Kon, Masanori; Fukushi, Shouji; Oota, Fumio; Kawamura, Kouji; Shinohe, Tetsuo; Suwa, Kouki; Fujii, Kiyosuke; Yamagami, Hirofumi

    2000-01-01

    The purpose of this project was to survey medical exposure doses in Aomori Prefecture and compare them with guidance levels for X-ray diagnosis. A questionnaire survey on X-ray diagnosis was conducted at the main medical institutions in the prefecture. The questionnaire asked about technical conditions, and replies were obtained from 72.2% of the 79 institutions. The medical exposure doses (entrance surface doses) were calculated from the results of the questionnaires by the modified numerical dose determination (NDD) method. The distribution of the entrance surface doses at each site was calculated as the 1st quartile, median, 3rd quartile, average, standard deviation, maximum value and minimum value, by the quartile method. The distribution of exposed doses at each site showed a similar pattern with that of the national distribution. Some institutions used higher doses than the Japanese proposed guidance levels and International Atomic Energy Agency (IAEA) guidance levels. Re-assessment of radiographic conditions and photosensitive materials is needed to reduce exposure doses. (K.H.)

  3. Joint analysis of French and Czech uranium miners: lung cancer risk at low radon exposure rates and modifying effects of time since exposure and age at exposure

    International Nuclear Information System (INIS)

    Ladislav Tomasek; Agnes Rogel; Margot Tirmarche; Dominique Laurier

    2006-01-01

    The present analysis was conducted in the frame of European project 'Quantification of lung cancer risk after low radon exposure and low exposure rate: synthesis from epidemiologic and experimental data'. The overall goal of the project related to uranium miners was the evaluation of lung cancer dose-response relationship and of dose rate effects among European uranium miners exposed to low doses and low dose rates of radon decay products. In addition, modifying factors like attained age, age at exposure and time since exposure were investigated. The joint analysis of French and Czech uranium miners was conducted mainly in order to increase the statistical power and to allow a more detailed description of the variation of dose-response relationship in time. (N.C.)

  4. Joint analysis of French and Czech uranium miners: lung cancer risk at low radon exposure rates and modifying effects of time since exposure and age at exposure

    Energy Technology Data Exchange (ETDEWEB)

    Ladislav Tomasek [National Radiation Protection Institute, Prague (Czech Republic); Agnes Rogel; Margot Tirmarche; Dominique Laurier [Institut de Radioprotection et de Surete Nucleaire, Fontenay-aux-Roses (France)

    2006-07-01

    The present analysis was conducted in the frame of European project 'Quantification of lung cancer risk after low radon exposure and low exposure rate: synthesis from epidemiologic and experimental data'. The overall goal of the project related to uranium miners was the evaluation of lung cancer dose-response relationship and of dose rate effects among European uranium miners exposed to low doses and low dose rates of radon decay products. In addition, modifying factors like attained age, age at exposure and time since exposure were investigated. The joint analysis of French and Czech uranium miners was conducted mainly in order to increase the statistical power and to allow a more detailed description of the variation of dose-response relationship in time. (N.C.)

  5. Studies of X-ray tube aging by non-invasive methods

    International Nuclear Information System (INIS)

    Bottaro, Marcio.

    2007-01-01

    The objective of the present work was the evaluation of an x ray tube aging with an anode made of tungsten, used in radio diagnostic. Workloads were applied, in accordance with Brazilian workload distribution, and periodic measurements of quantities related to the radiation quality of the beam were performed. For the purpose of this work, a single phase, full bridge clinical system was employed. For the long term x ray tube characteristics evaluation related to the applied workload, it was necessary to measure parameters that could quantitatively represent the tube aging, with special attention to the anode roughening. For the indirect measurement of tube aging, four parameters were chosen, some of them normally applied in x ray diagnostic quality control: first and second half value layers (HVL), focal spot dimensions, non invasive measurement of Practical Peak Voltage (PPV) and x ray spectroscopy. These parameters were measured before any workload and after each workload intervals. To assure confidence of the results reproducibility conditions were stated to each evaluated parameter. The uncertainties involved in all measurement processes were calculated to evaluate the real contributions of x ray tube aging effects on non invasive parameters. Within all evaluated parameters, the most sensitive to long term workload were the mean energy obtained from spectroscopy and half value layers. A model related to these parameters was applied and estimates of x ray tube aging rate for different acceleration voltages and anodic currents were calculated. (author)

  6. Einstein X-ray survey of the Pleiades - The dependence of X-ray emission on stellar age

    Science.gov (United States)

    Micela, G.; Sciortino, S.; Serio, S.; Vaiana, G. S.; Bookbinder, J.; Golub, L.; Harnden, F. R., Jr.; Rosner, R.

    1985-01-01

    The data obtained with two pointed observations of 1 deg by 1 deg fields of the Pleiades region have been analyzed, and the results are presented. The maximum-likelihood X-ray luminosity functions for the Pleiades G and K stars in the cluster are derived, and it is shown that, for the G stars, the Pleiades X-ray luminosity function is significantly brighter than the corresponding function for Hyades G dwarf stars. This finding indicates a dependence of X-ray luminosity on stellar age, which is confirmed by comparison of the same data with median X-ray luminosities of pre-main sequence and local disk population dwarf G stars. It is suggested that the significantly larger number of bright X-ray sources associated with G stars than with K stars, the lack of detection of M stars, and the relatively rapid rotation of the Pleiades K stars can be explained in terms of the onset of internal differential rotation near the convective envelope-radidative core interface after the spin-up phase during evolution to the main sequence.

  7. Radiation exposure to the patient during X-ray fluoroscopy and radiography

    International Nuclear Information System (INIS)

    Dimov, A.; Vassileva, J.

    2006-01-01

    Full text: The aim of this study is to assess the patient doses received during conventional and digital X-ray radiography, conventional fluoroscopy of the lungs, and one of the highest dose X-ray procedures - contrast examination of the large intestine (Barium enema examination). The measured quantity is Kerma area product (KAP), registered with a clinical dosimeter DRK-1 (Doza, Russia). A total number of 89 patients are included in the study. The Organ doses and Effective doses were assessed using Monte Carlo calculation code (PCXMC 1.4 (Finland). The measurements took place at the following X-ray units: a CGR (Koch and Sterzel) with two working posts - for radiography and fluoroscopy, a Philips Telediagnost (for barium enema) and an Oldelft N800HF Digidelca (for digital radiography of the chest). The typical KAP per procedure at digital radiography, conventional X-ray radiography and fluoroscopy and Barium enema examination are: 17; 95; 928 and 3630 cGy.cm 2 respectively; the average effective doses are: 0.022; 0.053; 0.728 and 8.0 mSv respectively. Doses to the lungs at digital radiography, conventional radiography and fluoroscopy are: 0.066; 0.136 and 2.412 mSv respectively and the dose to the upper and lower large intestine are: 11.7 and 8.6 mSv respectively. Conclusion: The approach used is applicable for assessment of radiation exposure to the patient during X-ray radiography and fluoroscopy. It needs registration of KAP meter readings when this device is installed on the stationary X-ray units

  8. Exposure to indoor air pollution in a reconstructed house from Danish Iron Age

    DEFF Research Database (Denmark)

    Skov, Henrik; Christensen, Carsten Stentoft; Fenger, Jes

    2000-01-01

    The adverse effects of air pollution on health have been recognised for millennia, but only in recent centuries they have been directly documented. In this paper evidence of the levels of exposure in the Danish Iron Age has been obtained from real measurements. The personal exposure to NO2...

  9. AGE-RELATED TOXICITY PATHWAY ANALYSIS IN BROWN NORWAY RAT BRAIN FOLLOWING ACUTE TOLUENE EXPOSURE

    Science.gov (United States)

    The influence of aging on susceptibility to environmental exposures is poorly understood. To investigate-the contribution of different life stages on response to toxicants, we examined the effects of an acute exposure to the volatile organic compound, toluene (0.0 or 1.0 g/kg), i...

  10. Radiation exposure of holding personnel involved in veterinary X-ray diagnosis

    International Nuclear Information System (INIS)

    Rothe, W.

    1977-01-01

    An account is given of radiation protection in the context of X-ray examination of small and big animals on the premises of seven reviewed veterinary centres. Also reported are the dosimetric results obtained from holding personnel involved in X-ray diagnosis of 319 big and 4,047 small animals. Infringement of valid regulations was quite often observed, in that animals are held in position in an inadequate way and by unauthorised persons. The measured results, however, have shown that the radiation exposure of vocationally exposed persons can be kept far below the maximum permissible equivalent doses, provided that all applicable rules of radiation protection are observed by those on duty. (author)

  11. Maternal air pollution exposure and preterm birth in Wuxi, China: Effect modification by maternal age.

    Science.gov (United States)

    Han, Yingying; Jiang, Panhua; Dong, Tianyu; Ding, Xinliang; Chen, Ting; Villanger, Gro Dehli; Aase, Heidi; Huang, Lu; Xia, Yankai

    2018-08-15

    Numerous studies have investigated prenatal air pollution and shown that air pollutants have adverse effect on birth outcomes. However, which trimester was the most sensitive and whether the effect was related to maternal age is still ambiguous. This study aims to explore the association between maternal air pollution exposure during pregnancy and preterm birth, and if this relationship is modified by maternal age. In this retrospective cohort study, we examine the causal relationship of prenatal exposure to air pollutants including particulate matters, which are less than 10 µm (PM 10 ), and ozone (O 3 ), which is one of the gaseous pollutants, on preterm birth by gestational age. A total of 6693 pregnant women were recruited from Wuxi Maternal and Child Health Care Hospital. The participants were dichotomized into child-bearing age group ( = 35 years old) in order to analyze the effect modification by maternal age. Logistic and linear regression models were performed to assess the risk for preterm birth (gestational age air pollution exposure. With adjustment for covariates, the highest level of PM 10 exposure significantly increased the risk of preterm birth by 1.42-fold (95% CI: 1.10, 1.85) compared those with the lowest level in the second trimester. Trimester-specific PM 10 exposure was positively associated with gestational age, whereas O 3 exposure was associated with gestational age in the early pregnancy. When stratified by maternal age, PM 10 exposure was significantly associated with an increased risk of preterm birth only in the advanced age group during pregnancy (OR:2.15, 95% CI: 1.13, 4.07). The results suggested that PM 10 exposure associated with preterm birth was modified by advanced maternal age (OR interaction = 2.00, 95% CI: 1.02, 3.91, P interaction = 0.032). Prenatal air pollution exposure would increase risk of preterm birth and reduced gestational age. Thus, more attention should be paid to the effects of ambient air pollution

  12. TOXICOGENOMIC ANALYSIS OF TOLUENE EXPOSURE AT 3 AGES IN BROWN NORWAY RATS.

    Science.gov (United States)

    A major concern in assessing toxicity to environmental exposures is differentialsusceptibility in subsets of the population. Aging adults, who comprise the fastestgrowing segment of the population, may possess a greater sensitivity due to changes inmetabol...

  13. Radiation exposure of the Yazd Population from medical conventional X-ray examinations

    International Nuclear Information System (INIS)

    Bouzarjomehri, F.; Zare, M. H.; Dashti, M. H.

    2007-01-01

    Radiation dose knowledge through X-ray examinations and their distribution in Iran provides useful guidance on patient dose reduction. The results of the entrance skin dose (ESD s ) of five common radiographs in all radiology centers in Yazd province were reported in our previous study (2003). In the present study we have evaluated the collective effective dose of conventional X-ray examinations, as well as the annual per caput of Yazd population.Materials and Methods: The annual frequencies of 18 different types of conventional radiology examinations during April 2005 to March 2006 were recorded from all 35 radiology centers in Yazd province. The exposure conditions consisted of kVp, mAs, and Focus surface distance (FSD) of the examinations for the mode of exposure in each X-ray unit. 620 ESD were measured by diode dosimeter in 35 hospitals and clinics. The real exposure kVp for each radiology unit was measured by a Molt-0-Meter. The conversion coefficient (effective dose - ESD ratio) for each radiology examination was determined by using SR262 tables. Finally, the patients' effective dose was calculated by multiplying the conversion factor to the ESD. Results: The patients' annual collective effective dose due to the conventional radiology examinations was 31.159 man-Sv (0.03 mSv per inhabitant). The frequency of examinations was 311813 i.e. 0.36 examinations per head of the population for one year. Conclusion: According to our findings, the effective per caput dose seems to be optimally relative to HCL-II countries, which may be due to low mean effective dose that could obscure high examination frequency. The number of radiology conventional examinations and frequency of radiologist per1000 population of Yazd was more and lower than HCL-II countries respectively. Thus the justification of radiography requests in this province must be revised

  14. Research of age changes of bone tissue of dual-energy X-ray absorptiometry

    International Nuclear Information System (INIS)

    Rizhik, V.M.; Kmetyuk, V.M.; Fed'kyiv, S.V.

    2003-01-01

    With the help of a method dual-energy x-ray absorptiometry (DEXA) mineral density bone tissue was defined in view of age, sex and individual features. Is established, that the parameters (DEXA) have precise interrelation with age changes in bone tissue, which aris with osteoporosis and have the certain clinical value

  15. ANATOMICAL DISPOSITION OF CARPAL BONES OF GOLDEN RETRIEVER DOG BY X-RAY EXPOSURE

    Directory of Open Access Journals (Sweden)

    R. Mandal

    2012-07-01

    Full Text Available The present study was conducted to know the general disposition of bones in carpal region of experimental dogs by X-ray study with an objective that the findings will facilitate to have an in-depth knowledge about the proper positioning of the carpal bones for surgical management of fractures and different types of bone deformities in dogs. In the present study, the anatomical disposition and arrangement pattern of carpal bones playing a pivotal role in providing the structural conformity in the limbs of Golden Retriever dog has been thoroughly confirmed by Xray exposure.

  16. DNA Topoisomerase-I Inhibition due to Exposure to X-Rays

    International Nuclear Information System (INIS)

    Daudee, R.; Gonen, R.; German, U.; Orion, I.; Priel, E.

    2014-01-01

    In events such as radiological terrorism, accidents involving radioactive materials and occupational exposures, there is a great need to identify exposures to relatively low radiation levels. In many situations, the evaluation of radiation doses is not possible using physical dosimeters as they are not worn, and it is desirable to achieve this based on sensitive biomarkers (1, 2, 3). DNA Topoisomerase-I (Topo-I) is an essential nuclear enzyme that is responsible for the topological state of the DNA. The enzyme is involved in a variety of DNA transactions, including replication, transcription, recombination and DNA repair (4,5). The aim of the present work was to investigate the influence of X-ray radiation on the catalytic activity of this enzyme, and to evaluate its applicability as a biological dosimeter

  17. Decline in measles mortality: nutrition, age at infection, or exposure?

    Science.gov (United States)

    Aaby, Peter; Bukh, Jette; Lisse, Ida Maria; da Silva, Maria Clotilde

    1988-01-01

    The mortality from measles was studied in an urban area of Guinea-Bissau one year before and five years after the introduction of a vaccination programme. The years after the introduction of immunisation saw a decline in mortality among unvaccinated children with measles. This decline occurred despite a lower age at infection and an increasing prevalence of malnourished children. State of nutrition (weight for age) did not affect the outcome of measles infection. The incidence of isolated cases, however, increased in the period after the introduction of measles vaccination. As mortality was lower among these cases, diminished clustering explained some of the reduction in mortality. Comparison between the urban district and a rural area inhabited by the same ethnic group showed a lower age at infection, less clustering of cases, and lower case fatality ratios in the urban area. Endemic transmission of measles in urban districts leads to less clustering of cases, which may help explain the usually lower case fatality ratios in these areas. As measles vaccination increases herd immunity and diminishes clustering of cases, it may reduce mortality even among unvaccinated children who contract the disease. PMID:3133023

  18. Real-Time Aircraft Cosmic Ray Radiation Exposure Predictions from the NAIRAS Model

    Science.gov (United States)

    Mertens, C. J.; Tobiska, W.; Kress, B. T.; Xu, X.

    2012-12-01

    The Nowcast of Atmospheric Ionizing Radiation for Aviation Safety (NAIRAS) is a prototype operational model for predicting commercial aircraft radiation exposure from galactic and solar cosmic rays. NAIRAS predictions are currently streaming live from the project's public website, and the exposure rate nowcast is also available on the SpaceWx smartphone app for iPhone, IPad, and Android. Cosmic rays are the primary source of human exposure to high linear energy transfer radiation at aircraft altitudes, which increases the risk of cancer and other adverse health effects. Thus, the NAIRAS model addresses an important national need with broad societal, public health and economic benefits. There is also interest in extending NAIRAS to the LEO environment to address radiation hazard issues for the emerging commercial spaceflight industry. The processes responsible for the variability in the solar wind, interplanetary magnetic field, solar energetic particle spectrum, and the dynamical response of the magnetosphere to these space environment inputs, strongly influence the composition and energy distribution of the atmospheric ionizing radiation field. Real-time observations are required at a variety of locations within the geospace environment. The NAIRAS model is driven by real-time input data from ground-, atmospheric-, and space-based platforms. During the development of the NAIRAS model, new science questions and observational data gaps were identified that must be addressed in order to obtain a more reliable and robust operational model of atmospheric radiation exposure. The focus of this talk is to present the current capabilities of the NAIRAS model, discuss future developments in aviation radiation modeling and instrumentation, and propose strategies and methodologies of bridging known gaps in current modeling and observational capabilities.

  19. Modifications of γ-ray sensitivity of bacterial membranes by pre-exposure to light

    International Nuclear Information System (INIS)

    Misiti-Dorello, P.; Cancelliere, G.; De Martino, G.; Quintilini, M.

    1976-01-01

    The exposure of E. coli B/r cells to ultraviolet or to visible light prior to irradiation with γ-rays modifies the sensitivity of the cell membrane to radiation damage responsible for the intracellular K + content. Exposure of bacterial cells to sublethal doses of UV radiation increases their sensitivity to γ-induced membrane damage, while exposure to visible light has the opposite effect. In combined exposures, the visible light, either given before or after the UV always produces a strong photoprotective effect. In either case, the photosensitizing effect of UV is completely suppressed. The photoprotection decays with time if cell suspensions are left in the dark before γ-irradiation. At O 0 C, the half-life of the photoprotective effect is 25 min at pH 7 and 100 min at pH 7.5. The decay is due to the presence of oxygen. The light band responsible for the induction of photoprotection has been estimated to lie in the wavelenght region between 540 and 580 nm. (orig./MG) [de

  20. Isotopic Evidence for Multi-stage Cosmic-ray Exposure Histories of Lunar Meteorites: Long Residence on the Moon and Short Transition to the Earth

    International Nuclear Information System (INIS)

    Hidaka, Hiroshi; Sakuma, Keisuke; Nishiizumi, Kunihiko; Yoneda, Shigekazu

    2017-01-01

    It is known that most lunar meteorites have complicated cosmic-ray exposure experiences on the Moon and in space. In this study, cosmic-ray irradiation histories of six lunar meteorites, Dhofar 489, Northwest Africa 032 (NWA 032), NWA 479, NWA 482, NWA 2995, and NWA 5000, were characterized from neutron-captured isotopic shifts of Sm and Gd, and from the abundances of long-lived cosmogenic radionuclides like 10 Be, 26 Al, 36 Cl, and 41 Ca. Sm and Gd isotopic data of all of six meteorites show significant isotopic shifts of 149 Sm– 150 Sm and 157 Gd– 158 Gd caused by accumulation of neutron capture reactions due to cosmic-ray irradiation, corresponding to the neutron fluences of (1.3–9.6) × 10 16 n cm −2 . In particular, very large Sm and Gd isotopic shifts of NWA 482 are over those of a lunar regolith 70002, having the largest isotopic shifts among the Apollo regolith samples, corresponding to cosmic-ray exposure duration over 800 million years in the lunar surface (2 π irradiation). Meanwhile, the concentrations of cosmogenic radionuclides for individual six meteorites show the short irradiation time less than one million years as their bodies in space (4 π irradiation). Our data also support the results of previous studies, revealing that most of lunar meteorites have long exposure ages at shallow depths on the Moon and short transit times from the Moon to the Earth.

  1. Inequities in workplace secondhand smoke exposure among nonsmoking women of reproductive age.

    Science.gov (United States)

    Johnson, Candice Y; Luckhaupt, Sara E; Lawson, Christina C

    2015-07-01

    We characterized workplace secondhand smoke exposure among nonsmoking women of reproductive age as a proxy for workplace secondhand smoke exposure during pregnancy. We included nonsmoking women aged 18 to 44 years employed during the past 12 months who participated in the 2010 National Health Interview Survey. We estimated the prevalence of workplace secondhand smoke exposure and its associations with sociodemographic and workplace characteristics. Nine percent of women reported workplace secondhand smoke exposure. Prevalence decreased with increasing age, education, and earnings. Workplace secondhand smoke exposure was associated with chemical exposure (prevalence odds ratio [POR] = 3.3; 95% confidence interval [CI] = 2.3, 4.7); being threatened, bullied, or harassed (POR = 3.2; 95% CI = 2.1, 5.1); vapors, gas, dust, or fume exposure (POR = 3.1; 95% CI = 2.3, 4.4); and worrying about unemployment (POR = 3.0; 95% CI = 1.8, 5.2), among other things. Comprehensive smoke-free laws covering all workers could eliminate inequities in workplace secondhand smoke exposure, including during pregnancy.

  2. Effects of occupational exposure of X-Ray on hematological parameters of diagnostic technicians

    Science.gov (United States)

    Taqi, Ali H.; Faraj, Kharman A.; Zaynal, Sarah A.; Hameed, Ahmed M.; Mahmood, Abd-Alkader A.

    2018-06-01

    The aim of this study was to identify the effects of long term exposure of X-ray on diagnostic technicians which they work at Kirkuk hospitals through examining some hematological parameters which are white blood cells (WBC), Neutrophils, Lymphocyte, Monocyte, Eosinophil, Basophil, Reactive Lymphocyte, red blood cells (RBC), hemoglobin (Hb), hematocrit (HCT), Mean Cell Volume (MCV), Mean Corpuscular Hemoglobin (MCH), Mean Cell Hemoglobin Concentration (MCHC), Red Cell Distribution Width (RDW), Platelet (PLT). The study included 54 male diagnostic technicians and 54 male healthy controls match with the first group to show any alteration of the hematological parameters. The diagnostic technicians divided into two groups depending on their work experience and hours working per day. The statistical analysis was performed using (Graph-pad) program. Our results showed that the Complete blood cells count (CBC) parameters (Neutrophil, Monocytes, Basophile, MCV, RDW and PLT) significantly (Pgroups of the diagnostic technicians compared with their controls. We concluded that chronic exposure of X-ray can significantly alter some hematological parameters and the number of hours working per day has observable effects on the some hematological parameters. We recommended training and courses about hazard of ionizing radiation should be organized for enhance the healthcare quality of the technicians and to improve their knowledge about benefit of radiation protection tools to protect themselves from any overexposure during the daily life.

  3. Effects of pre-natal X-ray exposure on learning behaviour of mice

    International Nuclear Information System (INIS)

    Frank, P.; Faber, U.; Budny, T.

    1983-01-01

    The authors investigated whether prenatal X-raying affects the learning behaviour of mice. For this purpose they irradiated mice of strain C57BL/6Ffm with 130 r at different points of the fetal phase. Unirradiated mice served as controls. The animals underwent two learning test series of 14 days each teaching them optical signs. The results of the test series show a distinctly inferior learning ability in the animals exposed to pre-natal irradiation as compared to unirradiated controls. The extent of the reduction of the learning ability depends on the stage of the pregnancy at the time of X-ray exposure. The greatest difference as compared to non-irradiated mice occurred in the animals irradiated at the earliest stage (13th/14th day of pregnancy). The results of the other test groups (15th/16th and 17th/18th day of pregnancy) exhibited less distinct, but still significant differences to the controls. Exposure at the latest period (17th/18th day) coincided with the smallest difference. (orig./MG) [de

  4. Cellular oncogene expression following exposure of mice to γ-rays

    International Nuclear Information System (INIS)

    Anderson, A.; Woloschak, G.E.

    1991-01-01

    We examined the effects of total body exposure of BCF1 mice to γ-rays (300 cGy) in modulating expression of cellular oncogenes in both gut and liver tissues. We selected specific cellular oncogenes (c-fos, c-myc, c-src, and c-H-ras), based on their normal expression in liver and gut tissues from untreated mice. As early as 5 min. following whole body exposure of BCF1 mice to γ-rays we detected induction of mRNA specific for c-src and c-H-ras in both liver and gut tissues. c-fos RNA was slightly decreased in accumulation in gut but was unaffected in liver tissue from irradiated mice relative to untreated controls. c-myc mRNA accumulation was unaffected in all tissues examined. These experiments document that modulation of cellular oncogene expression can occur as an early event in tissues following irradiation and suggest that this modulation may play a role in radiation-induced carcinogenesis

  5. Noble gases, nitrogen, cosmic ray exposure history and mineralogy of Beni M'hira (L6) chondrite

    Science.gov (United States)

    Mahajan, Ramakant R.; Nejia, Laridhi Ouazaa; Ray, Dwijesh; Naik, Sekhar

    2018-03-01

    The concentrations and isotopic composition of noble gases helium (He), neon (Ne), argon (Ar), krypton (Kr), xenon(Xe) and nitrogen were measured in the Beni M'hira L6 chondrite. The cosmic ray exposure age of Beni M'hira is estimated of 15.6 ± 3.7 (Ma). The radiogenic age, of around 485 ± 64 Ma, derived from 4He, and of around 504 ± 51 Ma from 40Ar, suggests an age resetting indicating the event impact. The heavy noble gases (Ar, Kr and Xe) concentrations imply that the gas is a mixture of trapped component Q and solar wind. The measured nitrogen abundance of 0.74 ppm and the isotopic signature of δ15N = 14.6‰ are within the range of ordinary chondrites. The homogeneous chemical composition of olivine (Fa:26 ± 0.25) and low-Ca pyroxene (Fs:22.4 ± 0.29) suggest that the Beni M'hira meteorite is an equilibrated chondrite. This is further corroborated by strong chondrule-matrix textural integration (lack of chondrules, except a few relict clast). Shock metamorphism generally corresponds to S5 (>45 GPa), however, locally disequilibrium melting (shock-melt veins) suggests, that the peak shock metamorphism was at ∼75 GPa, 950 °C.

  6. Shorter exposures to harder X-rays trigger early apoptotic events in Xenopus laevis embryos.

    Directory of Open Access Journals (Sweden)

    JiaJia Dong

    Full Text Available BACKGROUND: A long-standing conventional view of radiation-induced apoptosis is that increased exposure results in augmented apoptosis in a biological system, with a threshold below which radiation doses do not cause any significant increase in cell death. The consequences of this belief impact the extent to which malignant diseases and non-malignant conditions are therapeutically treated and how radiation is used in combination with other therapies. Our research challenges the current dogma of dose-dependent induction of apoptosis and establishes a new parallel paradigm to the photoelectric effect in biological systems. METHODOLOGY/PRINCIPAL FINDINGS: We explored how the energy of individual X-ray photons and exposure time, both factors that determine the total dose, influence the occurrence of cell death in early Xenopus embryo. Three different experimental scenarios were analyzed and morphological and biochemical hallmarks of apoptosis were evaluated. Initially, we examined cell death events in embryos exposed to increasing incident energies when the exposure time was preset. Then, we evaluated the embryo's response when the exposure time was augmented while the energy value remained constant. Lastly, we studied the incidence of apoptosis in embryos exposed to an equal total dose of radiation that resulted from increasing the incoming energy while lowering the exposure time. CONCLUSIONS/SIGNIFICANCE: Overall, our data establish that the energy of the incident photon is a major contributor to the outcome of the biological system. In particular, for embryos exposed under identical conditions and delivered the same absorbed dose of radiation, the response is significantly increased when shorter bursts of more energetic photons are used. These results suggest that biological organisms display properties similar to the photoelectric effect in physical systems and provide new insights into how radiation-mediated apoptosis should be understood and

  7. Implication of occupational exposure to X-Rays diagnosed during pregnancy

    International Nuclear Information System (INIS)

    Frometa Suarez, Ileana

    1998-01-01

    At the present time the risks have been described thoroughly and goods on the inherent fetus to the exhibition give sources ionizing radiations in women that are in period gestation. Presently investigation work is carried out for survey of women exposed to occupational ionizing radiations in reproductive age. The incidence is described and behavior gives these goods and its relationship with other risk factors. In this study the exposure to ionizing radiations is not revealed as main causal factor risk

  8. A synchrotron-based X-ray exposure station for radiation biology experiments

    International Nuclear Information System (INIS)

    Thompson, A.C.; Blakely, E.A.; Bjornstad, K.A.; Chang, P.Y.; Rosen, C.J.; Schwarz, R.I.

    2007-01-01

    Synchrotron X-ray sources enable radiation biology experiments that are difficult with conventional sources. A synchrotron source can easily deliver a monochromatic, tunable energy, highly collimated X-ray beam of well-calibrated intensity. An exposure station at beamline 10.3.1 of the Advanced Light Source (ALS) has been developed which delivers a variable energy (5-20 keV) X-ray fan beam with very sharp edges (10-90% in less than 3 μm). A series of experiments have been done with a four-well slide where a stripe (100 μm widex18 mm long) of cells in each well has been irradiated and the dose varied from well to well. With this facility we have begun a series of experiments to study cells adjacent to irradiated cells and how they respond to the damage of their neighbors. Initial results have demonstrated the advantages of using synchrotron radiation for these experiments

  9. A synchrotron-based X-ray exposure station for radiation biology experiments

    Energy Technology Data Exchange (ETDEWEB)

    Thompson, A.C. [Division of Life Sciences, Lawrence Berkeley National Laboratory, Bld. 50A-6120, Berkeley, CA 94720 (United States)], E-mail: acthompson@lbl.gov; Blakely, E.A.; Bjornstad, K.A. [Division of Life Sciences, Lawrence Berkeley National Laboratory, Bld. 50A-6120, Berkeley, CA 94720 (United States); Chang, P.Y. [Division of Life Sciences, Lawrence Berkeley National Laboratory, Bld. 50A-6120, Berkeley, CA 94720 (United States); SRI International, Menlo Park, CA (United States); Rosen, C.J.; Schwarz, R.I. [Division of Life Sciences, Lawrence Berkeley National Laboratory, Bld. 50A-6120, Berkeley, CA 94720 (United States)

    2007-11-11

    Synchrotron X-ray sources enable radiation biology experiments that are difficult with conventional sources. A synchrotron source can easily deliver a monochromatic, tunable energy, highly collimated X-ray beam of well-calibrated intensity. An exposure station at beamline 10.3.1 of the Advanced Light Source (ALS) has been developed which delivers a variable energy (5-20 keV) X-ray fan beam with very sharp edges (10-90% in less than 3 {mu}m). A series of experiments have been done with a four-well slide where a stripe (100 {mu}m widex18 mm long) of cells in each well has been irradiated and the dose varied from well to well. With this facility we have begun a series of experiments to study cells adjacent to irradiated cells and how they respond to the damage of their neighbors. Initial results have demonstrated the advantages of using synchrotron radiation for these experiments.

  10. Neurological outcome in school-age children after in utero exposure to coumarins

    NARCIS (Netherlands)

    Wesseling, J; Van Driel, D; Smrkovsky, M; Van der Veer, E; Geven-Boere, LM; Sauer, PJJ; Touwen, BCL

    The effect of prenatal exposure to coumarins (acenocoumarol, phenprocoumon) on neurological outcome was assessed in a cohort of 306 children aged 7-15 years. Findings were compared with those in a non-exposed cohort of 267 children, matched for sex, age, and demographic region. We used a

  11. Estimated exposures to perfluorinated compounds in infancy predict attenuated vaccine antibody concentrations at age 5-years

    DEFF Research Database (Denmark)

    Grandjean, Philippe; Heilmann, Carsten; Weihe, Pal

    2017-01-01

    Perfluorinated alkylate substances (PFASs) are highly persistent and may cause immunotoxic effects. PFAS-associated attenuated antibody responses to childhood vaccines may be affected by PFAS exposures during infancy, where breastfeeding adds to PFAS exposures. Of 490 members of a Faroese birth...... cohort, 275 and 349 participated in clinical examinations and provided blood samples at ages 18 months and 5 years. PFAS concentrations were measured at birth and at the clinical examinations. Using information on duration of breastfeeding, serum-PFAS concentration profiles during infancy were estimated......, with decreases by up to about 20% for each two-fold higher exposure, while associations for serum concentrations at ages 18 months and 5 years were weaker. Modeling of serum-PFAS concentration showed levels for age 18 months that were similar to those measured. Concentrations estimated for ages 3 and 6 months...

  12. Study on exposures in incidents situations involving X-ray generators of industrial use

    International Nuclear Information System (INIS)

    Rios, Paulo B.; Rios, Denise A. da S.

    2014-01-01

    Case studies of accidents involving radiation sources provides valuable information for the improvement of equipment and procedures to be adopted to prevent their recurrence. Therefore, they are recommended as part of the licensing process of radiative facilities. However, when the equipment has no radiological protection requirements or have no record of accidents, an effective method to appropriate this knowledge necessary to improvements of process and project is the investigation of reported incidents and the proposition limit situations where exposures unlikely and even low intensity can occur. This work reviews incidents in X-ray equipment and thickness meters. Emergency situations are also studied in this type of equipment and in an accelerator of electrons self-shielded for curing of paints and varnishes. The exposure estimates are calculated from data collected in workplaces on the distance and time for each proposed case. Although there is no severe consequences to occupational health, the results can be used to improve the quality of training for operators and maintenance technicians, for proposing of new alarm systems and emergency teams procedures and may serve as a warning in inadvertent and avoidable situations of unnecessary exposures

  13. Implementation of a primary standard for a x-ray exposure

    International Nuclear Information System (INIS)

    peixoto, J.G.P.

    1991-04-01

    In the scientific program of the National Laboratory for Ionizing Radiation Metrology of the Instituto de Radioprotecao e Dosimetria, which belongs to the Comissao Nacional de Energia Nuclear, a free-air ionization chamber should be established as an exposure primary standard for X-rays of 100 K V to 250 K V of potential range. Preliminary results showed that the available free-air ionization chamber was suitable to be used. The absolute measurement of the radiation quantity exposure, is performed with a free-air ionization chamber. Its geometrical volume, which allows the determination of the air mass, is defined by the effective aperture area and by the length of the region where an electrical field is applied. Most of the ions produced in such volume are collected as an ionization current. Parameters related to the measurement of the quantity exposure were evaluated, such as: air absorption, scattering inside the ionization chamber, saturation, beam homogeneity, influence of beam size and influences of temperature, humidity and atmospheric pressure. Preliminary determination of correction factors has showed good results with 99.9% of repeatability and has demonstrated the reliability of the checked chamber as a standard instrument. (author)

  14. Assessing the impacts of lifetime sun exposure on skin damage and skin aging using a non-invasive method

    International Nuclear Information System (INIS)

    Kimlin, Michael G.; Guo, Yuming

    2012-01-01

    Background: Ultraviolet radiation exposure during an individuals' lifetime is a known risk factor for the development of skin cancer. However, less evidence is available on assessing the relationship between lifetime sun exposure and skin damage and skin aging. Objectives: This study aims to assess the relationship between lifetime sun exposure and skin damage and skin aging using a non-invasive measure of exposure. Methods: We recruited 180 participants (73 males, 107 females) aged 18–83 years. Digital imaging of skin hyperpigmentation (skin damage) and skin wrinkling (skin aging) on the facial region was measured. Lifetime sun exposure (presented as hours) was calculated from the participants' age multiplied by the estimated annual time outdoors for each year of life. We analyzed the effects of lifetime sun exposure on skin damage and skin aging. We adjust for the influence of age, sex, occupation, history of skin cancer, eye color, hair color, and skin color. Results: There were non-linear relationships between lifetime sun exposure and skin damage and skin aging. Younger participant's skin is much more sensitive to sun exposure than those who were over 50 years of age. As such, there were negative interactions between lifetime sun exposure and age. Age had linear effects on skin damage and skin aging. Conclusion: The data presented showed that self reported lifetime sun exposure was positively associated with skin damage and skin aging, in particular, the younger people. Future health promotion for sun exposure needs to pay attention to this group for skin cancer prevention messaging. - Highlights: ► This is the first study finding the non-linear relationship between lifetime sun exposure and skin damage and skin aging. ► This study finds there is negative interaction between lifetime sun exposure and age for skin damage and aging. ► This study suggests that future health promotion for sun exposure needs to pay attention to youth group for skin cancer

  15. Theoretical determination of spectrum-exposure rate conversion operator of HPGe detector and its application to the measurement of environmental gamma-ray exposure rate

    International Nuclear Information System (INIS)

    Park, Ch.M.; Choi, B.I.; Kwak, S.S.; Ji, P.K.; Kim, T.W.; Park, Y.W.; Yoon, B.K.

    1993-01-01

    A conversion operator between spectrum and exposure rate, using a portable HPGe detector for environmental radiation monitoring, was determined theoretically under the assumption of uniform distribution of radiation source on the ground surface. The measurement results were compared with those of a pressurized ionization chamber. The results obtained with the HPGe detector were slightly lower. The method can be easily applied to any gamma ray detector to obtain a spectrum - exposure-rate conversion factor for computing the exposure rate of environmental gamma radiation. (N.T.) 15 refs.; 6 figs.; 3 tabs

  16. Age at Exposure to Surgery and Anesthesia in Children and Association With Mental Disorder Diagnosis.

    Science.gov (United States)

    Ing, Caleb; Sun, Ming; Olfson, Mark; DiMaggio, Charles J; Sun, Lena S; Wall, Melanie M; Li, Guohua

    2017-12-01

    Animals exposed to anesthetics during specific age periods of brain development experience neurotoxicity, with neurodevelopmental changes subsequently observed during adulthood. The corresponding vulnerable age in children, however, is unknown. An observational cohort study was performed using a longitudinal dataset constructed by linking individual-level Medicaid claims from Texas and New York from 1999 to 2010. This dataset was evaluated to determine whether the timing of exposure to anesthesia ≤5 years of age for a single common procedure (pyloromyotomy, inguinal hernia, circumcision outside the perinatal period, or tonsillectomy and/or adenoidectomy) is associated with increased subsequent risk of diagnoses for any mental disorder, or specifically developmental delay (DD) such as reading and language disorders, and attention deficit hyperactivity disorder (ADHD). Exposure to anesthesia and surgery was evaluated in 11 separate age at exposure categories: ≤28 days old, >28 days and ≤6 months, >6 months and ≤1 year, and 6-month age intervals between >1 year old and ≤5 years old. For each exposed child, 5 children matched on propensity score calculated using sociodemographic and clinical covariates were selected for comparison. Cox proportional hazards models were used to measure the hazard ratio of a mental disorder diagnosis associated with exposure to surgery and anesthesia. A total of 38,493 children with a single exposure and 192,465 propensity score-matched children unexposed before 5 years of age were included in the analysis. Increased risk of mental disorder diagnosis was observed at all ages at exposure with an overall hazard ratio of 1.26 (95% confidence interval [CI], 1.22-1.30), which did not vary significantly with the timing of exposure. Analysis of DD and ADHD showed similar results, with elevated hazard ratios distributed evenly across all ages, and overall hazard ratios of 1.26 (95% CI, 1.20-1.32) for DD and 1.31 (95% CI, 1.25-1.37) for

  17. Exposure to power frequency magnetic fields suppresses X-ray-induced apoptosis transiently in Ku80-deficient xrs5 cells

    International Nuclear Information System (INIS)

    Tian, Furong; Nakahara, Takehisa; Yoshida, Masami; Honda, Naoko; Hirose, Hideki; Miyakoshi, Junji

    2002-01-01

    In an attempt to determine whether exposure to extremely low frequency (ELF) electromagnetic fields can affect cells, Ku80-deficient cells (xrs5) and Ku80-proficient cells (CHO-K1) were exposed to ELF electromagnetic fields. Cell survival, and the levels of the apoptosis-related genes p21, p53, phospho-p53 (Ser 15 ), caspase-3 and the anti-apoptosis gene bcl-2 were determined in xrs5 and CHO-K1 cells following exposure to ELF electromagnetic fields and X-rays. It was found that exposure of xrs5 and CHO-K1 cells to 60 Hz ELF electromagnetic fields had no effect on cell survival, cell cycle distribution and protein expression. Exposure of xrs5 cells to 60 Hz ELF electromagnetic fields for 5 h after irradiation significantly inhibited G 1 cell cycle arrest induced by X-rays (1 Gy) and resulted in elevated bcl-2 expression. A significant decrease in the induction of p53, phospho-p53, caspase-3 and p21 proteins was observed in xrs5 cells when irradiation by X-rays (8 Gy) was followed by exposure to 5 mT ELF magnetic fields. Exposure of xrs5 cells to the ELF electromagnetic fields for 10 h following irradiation significantly decreased X-ray-induced apoptosis from about 1.7% to 0.7%. However, this effect was not found in CHO-K1 cells within 24 h of irradiation by X-rays alone and by X-rays combined with ELF electromagnetic fields. Exposure of xrs5 cells to 60 Hz ELF electromagnetic fields following irradiation can affect cell cycle distribution and transiently suppress apoptosis by decreasing the levels of caspase-3, p21, p53 and phospho-p53 and by increasing bcl-2 expression

  18. Estimated exposures to perfluorinated compounds in infancy predict attenuated vaccine antibody concentrations at age 5-years.

    Science.gov (United States)

    Grandjean, Philippe; Heilmann, Carsten; Weihe, Pal; Nielsen, Flemming; Mogensen, Ulla B; Timmermann, Amalie; Budtz-Jørgensen, Esben

    2017-12-01

    Perfluorinated alkylate substances (PFASs) are highly persistent and may cause immunotoxic effects. PFAS-associated attenuated antibody responses to childhood vaccines may be affected by PFAS exposures during infancy, where breastfeeding adds to PFAS exposures. Of 490 members of a Faroese birth cohort, 275 and 349 participated in clinical examinations and provided blood samples at ages 18 months and 5 years. PFAS concentrations were measured at birth and at the clinical examinations. Using information on duration of breastfeeding, serum-PFAS concentration profiles during infancy were estimated. As outcomes, serum concentrations of antibodies against tetanus and diphtheria vaccines were determined at age 5. Data from a previous cohort born eight years earlier were available for pooled analyses. Pre-natal exposure showed inverse associations with the antibody concentrations five years later, with decreases by up to about 20% for each two-fold higher exposure, while associations for serum concentrations at ages 18 months and 5 years were weaker. Modeling of serum-PFAS concentration showed levels for age 18 months that were similar to those measured. Concentrations estimated for ages 3 and 6 months showed the strongest inverse associations with antibody concentrations at age 5 years, particularly for tetanus. Joint analyses showed statistically significant decreases in tetanus antibody concentrations by 19-29% at age 5 for each doubling of the PFAS exposure in early infancy. These findings support the notion that the developing adaptive immune system is particularly vulnerable to immunotoxicity during infancy. This vulnerability appears to be the greatest during the first 6 months after birth, where PFAS exposures are affected by breast-feeding.

  19. Exposure to metals during pregnancy and neuropsychological development at the age of 4 years

    OpenAIRE

    Forns, Joan; Fort, Marta; Casas, Maribel; Cáceres, Alejandro; Guxens, M.; Gascón, Mireia I.; García-Esteban, R.; Júlvez, Jordi; Grimalt, Joan O.; Sunyer, Jordi

    2015-01-01

    Background: There is insufficient epidemiological evidence for deciding whether prenatal exposure to the current low-levels of metals in developed countries may affect neuropsychological function in early childhood. Objectives: Our goal was to evaluate potential neurotoxic effects of prenatal exposure to seven metals (cobalt, copper, arsenic, cadmium, antimony, thallium and lead), during the 1st and 3rd trimester of pregnancy, on child neuropsychological development at 4 years of age. Materia...

  20. DNA repair: As influenced by age, nutrition, and exposure to toxic substances

    International Nuclear Information System (INIS)

    Hart, R.; Chou, Ming; Feuers, R.; Leakey, J.; Duffy, P.; Lyn-Cook, B.; Lipman, J.; Makamura, Kenji; Turturro, A.; Allaben, W.

    1992-01-01

    In evaluating the risk associated with low levels of exposure to toxicants, it is clear that DNA repair, one of the main defenses against agent damage, is not a constant. It can be modified by age, time of day, and physiological state. Nutrition, especially caloric restriction (CR), can modify almost every step in the process of protecting genomic integrity. And history of exposure can modify DNA repair. Thus, the conditions of exposure are almost as important to toxicity as the exposure itself, even at the level of DNA repair. Extrapolation from high to low dose, to be consistent with what is known, should be less a mathematical exercise than an exercise in toxicological judgement, which puts the exposure in proper perspective. This appears to be true at almost every level in the process including a response with a toxic stimulus, even those thought to be very basic, such as DNA repair

  1. Exposure to hazardous substances in Cathode Ray Tube (CRT) recycling sites in France

    Energy Technology Data Exchange (ETDEWEB)

    Lecler, Marie-Thérèse, E-mail: marie-therese.lecler@inrs.fr; Zimmermann, François; Silvente, Eric; Clerc, Frédéric; Chollot, Alain; Grosjean, Jérôme

    2015-05-15

    Highlights: • Chemical risks were assessed in the nine cathode ray tube screens recycling facilities. • The main hazardous agents are dust containing lead, cadmium, barium and yttrium. • Exposure and pollutant levels are described for different operations and processes. • All the operations and processes are concerned by significant levels of pollutants. • We suggest recommendations to reduce chemical risk. - Abstract: The Waste Electrical and Electronic Equipment (WEEE) or e-waste recycling sector has grown considerably in the last fifteen years due to the ever shorter life cycles of consumables and an increasingly restrictive policy context. Cathode Ray Tubes (CRTs) from used television and computer screens represent one of the main sources of e-waste. CRTs contain toxic materials such as lead, cadmium, barium, and fluorescent powders which can be released if recycling of CRTs is not appropriate. Exposure to these harmful substances was assessed in nine workshops where CRT screens are treated. Particulate exposure levels were measured using a gravimetric method and metals were analysed by plasma emission spectrometry. The maximum levels of worker exposure were 8.8 mg/m{sup 3}, 1504.3 μg/m{sup 3}, 434.9 μg/m{sup 3}, 576.3 μg/m{sup 3} and 2894.3 μg/m{sup 3} respectively for inhalable dust, barium, cadmium, lead and yttrium. The maximum levels of airborne pollutants in static samples were 39.0 mg/m{sup 3}, 848.2 μg/m{sup 3}, 698.4 μg/m{sup 3}, 549.3 μg/m{sup 3} and 3437.9 μg/m{sup 3} for inhalable dust, barium, cadmium, lead and yttrium. The most harmful operations were identified, and preventive measures for reducing the chemical risk associated with screen recycling were proposed. Workplace measurements were used to define recommendations for reducing the chemical risks in CRT screens recycling facilities and for promoting the design and development of “clean and safe” processes in emerging recycling channels.

  2. New X-Ray Technique to Characterize Nanoscale Precipitates in Aged Aluminum Alloys

    Science.gov (United States)

    Sitdikov, V. D.; Murashkin, M. Yu.; Valiev, R. Z.

    2017-10-01

    This paper puts forward a new technique for measurement of x-ray patterns, which enables to solve the problem of identification and determination of precipitates (nanoscale phases) in metallic alloys of the matrix type. The minimum detection limit of precipitates in the matrix of the base material provided by this technique constitutes as little as 1%. The identification of precipitates in x-ray patterns and their analysis are implemented through a transmission mode with a larger radiation area, longer holding time and higher diffractometer resolution as compared to the conventional reflection mode. The presented technique has been successfully employed to identify and quantitatively describe precipitates formed in the Al alloy of the Al-Mg-Si system as a result of artificial aging. For the first time, the x-ray phase analysis has been used to identify and measure precipitates formed during the alloy artificial aging.

  3. The Relationship of Korean Students' Age and Years of English-as-a-Foreign-Language Exposure with English-Reading Ability: A Cross-Age Study

    Science.gov (United States)

    Fitzgerald, Jill; Stenner, A. Jackson; Sanford-Moore, Eleanor E.; Koons, Heather; Bowen, Kimberly; Kim, Kee Hyung

    2015-01-01

    The purpose of the present cross-age study with South Korean students was to investigate the relationship of age and years of English-as-a-foreign-language (EFL) exposure with English-reading ability. The main research question was, "Do individuals' age and number of years of English exposure interact in relation to English-reading…

  4. Comparison of late effects of single x-ray exposure, chronic tritiated water ingestion, and chronic cesium-137 gamma exposure in mice

    International Nuclear Information System (INIS)

    Carsten, A.L.; Cronkite, E.P.

    1979-01-01

    There is concern over the possible late effects resulting from chronic exposure to tritiated water, a primary by-product of power reactors. We are comparing the genetic and somatic effects of tritiated water ingestion to acute x-ray or chronic cesium-137 gamma-ray exposures. Eight week old mice were maintaned on tritiated water in concentrations of 0.3, 1.0, and 3.0 μCi/ml. Identical animals received cesium-137 gamma exposures equivalent to that from the tritiated water. At 4 week intervals, animals were sacrificed and the hematopoietic stem cell content and cellularity of the bone marrow determined. For comparison of acute and chronic effects, one group of mice received a single whole-body x-ray exposure of 525 rads. The x-irradiated animals showed an immediate sharp decrease in marrow cellularity followed by gradual return to normal levels, with a lifelong reduction in number of marrow stem cells. Animals exposed to the two higher concentrations of tritiated water showed only slight reductions in marrow cellularity, with a lifelong reduction in hematopoietic stem cells in the bone marrow. Comparison of the external gamma exposures to chronic tritiated water ingestion indicates similar patterns. Maintenance of normal cellularity with a reduced number of stem cells in x-rayed animals was shown by tritiated thymidine cytocide to be due to the reduction in number of stem cells in the resting G/sub O/ stage. At this time it is not possible to determine whether there is a significant difference in relative biological effectiveness of tritiated water compared to cesium-137 gamma rays; however, indications are that they are similar

  5. Prenatal Exposure to Maternal Obesity Alters Anxiety and Stress Coping Behaviors in Aged Mice.

    Science.gov (United States)

    Balsevich, Georgia; Baumann, Valentin; Uribe, Andres; Chen, Alon; Schmidt, Mathias V

    2016-01-01

    There is growing evidence that maternal obesity and prenatal exposure to a high-fat diet program fetal development to regulate the physiology and behavior of the offspring in adulthood. Yet the extent to which the maternal dietary environment contributes to adult disease vulnerability remains unclear. In the current study we tested whether prenatal exposure to maternal obesity increases the offspring's vulnerability to stress-related psychiatric disorders. We used a mouse model of maternal diet-induced obesity to investigate whether maternal obesity affects the response to adult chronic stress exposure in young adult (3-month-old) and aged adult (12-month-old) offspring. Long-lasting, delayed impairments to anxiety-like behaviors and stress coping strategies resulted on account of prenatal exposure to maternal obesity. Although maternal obesity did not change the offspring's behavioral response to chronic stress per se, we demonstrate that the behavioral outcomes induced by prenatal exposure to maternal obesity parallel the deleterious effects of adult chronic stress exposure in aged male mice. We found that the glucocorticoid receptor (GR, Nr3c1) is upregulated in various hypothalamic nuclei on account of maternal obesity. In addition, gene expression of a known regulator of the GR, FKBP51, is increased specifically within the paraventricular nucleus. These findings indicate that maternal obesity parallels the deleterious effects of adult chronic stress exposure, and furthermore identifies GR/FKBP51 signaling as a novel candidate pathway regulated by maternal obesity. © 2015 S. Karger AG, Basel.

  6. Lifelong occupational exposures and hearing loss among elderly Latino Americans aged 65–75 years

    Science.gov (United States)

    Hong, OiSaeng; Chin, Dal Lae; Kerr, Madeleine J.

    2015-01-01

    Objective The purpose of this study is to determine the relationship between occupational exposures and hearing among elderly Latino Americans. Design A descriptive, correlational design used for this secondary analysis with the data from the Sacramento Area Latino Study of Aging (SALSA). Study sample A total of 547 older adults were included. Results A majority of participants (58%) reported occupational exposures to loud noise and/or ototoxic chemicals. About 65% and over 90% showed hearing loss at low and high frequencies, respectively. Participants with occupational exposure to loud noise and/or ototoxic chemicals were, significantly, two times more likely to have hearing loss at high frequencies compared to those without exposure (OR = 2.29; 95% CI: 1.17 – 4.51, p = .016), after controlling for other risk factors of hearing loss such as age, gender, household income, current smoking, and diabetes. However, lifelong occupational exposure was not significantly associated with hearing loss at low frequencies (OR = 1.43; 95% CI: 0.94 – 2.18, p = .094). Conclusion Lifelong occupational exposure to loud noise and/or ototoxic chemicals was significantly associated with hearing loss among elderly Latino Americans. Healthy work life through protection from harmful auditory effects of occupational exposures to noise and chemicals will have a positive impact on better hearing in later life. PMID:25549170

  7. Lifelong occupational exposures and hearing loss among elderly Latino Americans aged 65-75 years.

    Science.gov (United States)

    Hong, OiSaeng; Chin, Dal Lae; Kerr, Madeleine J

    2015-02-01

    The purpose of this study is to determine the relationship between occupational exposures and hearing among elderly Latino Americans. A descriptive, correlational design used for this secondary analysis with the data from the Sacramento Area Latino Study of Aging (SALSA). A total of 547 older adults were included. A majority of participants (58%) reported occupational exposures to loud noise and/or ototoxic chemicals. About 65% and over 90% showed hearing loss at low and high frequencies, respectively. Participants with occupational exposure to loud noise and/or ototoxic chemicals were, significantly, two times more likely to have hearing loss at high frequencies compared to those without exposure (OR = 2.29; 95% CI: 1.17 = 4.51, p = .016), after controlling for other risk factors of hearing loss such as age, gender, household income, current smoking, and diabetes. However, lifelong occupational exposure was not significantly associated with hearing loss at low frequencies (OR = 1.43; 95% CI: 0.94 = 2.18, p = .094). Lifelong occupational exposure to loud noise and/or ototoxic chemicals was significantly associated with hearing loss among elderly Latino Americans. Healthy work life through protection from harmful auditory effects of occupational exposures to noise and chemicals will have a positive impact on better hearing in later life.

  8. Improved model for solar cosmic ray exposure in manned Earth orbital flights

    International Nuclear Information System (INIS)

    Wilson, J.W.; Nealy, J.E.; Atwell, W.; Cucinotta, F.A.; Shinn, J.L.; Townsend, L.W.

    1990-06-01

    A calculational model is derived for use in estimating Solar cosmic ray exposure to critical body organs in low-Earth orbit at the center of a large spherical shield of fixed thickness. The effects of the Earth's geomagnetic field and the astronauts' self-shielding are evaluated explicitly. The geomagnetic field model is an approximate tilted eccentric dipole with geomagnetic storms represented as a uniform-impressed field. The storm field is related to the planetary geomagnetic index K(sub p). The code is applied to the Shuttle geometry using the Shuttle mass distribution surrounding two locations on the flight deck. The Shuttle is treated as pure aluminum and the astronaut as soft tissue. Short-term, average fluence over a single orbit is calculated as a function of the location of the lines of nodes or long-term averages over all lines of nodes for a fixed inclination

  9. Medical management of severe local radiation injury after acute X-ray exposure

    International Nuclear Information System (INIS)

    Bushmanov, A.; Nadezhina, N.; Kretov, A.

    2008-01-01

    Medical management during acute period in a case of severe local radiation injury after acute X-ray exposure includes 3 stages. During the fist stage patient got conservative treatment according to the common pathogenetic mechanisms of LRI (dis aggregating therapy, stimulation of regeneration, dis intoxication therapy, antibiotic therapy, pain relief therapy, Local anti-burn therapy-specific non-adhesive bandage with antiseptic and anti-burn medicaments); estimation of severity, deepness and area of injury by clinical picture and dates of instrumental methods of examining; defining necessity and volume of surgical treatment; preparing arrangements for surgical treatment. This stage ends with forming of demarcation line of a very hard severity of a Local Radiation Injure. The second stage includes necrectomy of the area of a very hard severity with microsurgical plastic by re vascularized flap and auto dermoplastic. The third stage - adaptation of re vascularized flap and total epithelization of injured area. (author)

  10. Gamma-ray energy absorption and exposure buildup factor studies in some human tissues with endometriosis

    Energy Technology Data Exchange (ETDEWEB)

    Kurudirek, Murat, E-mail: mkurudirek@gmail.co [Faculty of Science, Department of Physics, Ataturk University, 25240 Erzurum (Turkey); Dogan, Bekir [Faculty of Science, Department of Physics, Ataturk University, 25240 Erzurum (Turkey); Ingec, Metin [Faculty of Medicine, Department of Obstetrics and Gynecology, Ataturk University, 25240 Erzurum (Turkey); Ekinci, Neslihan; Ozdemir, Yueksel [Faculty of Science, Department of Physics, Ataturk University, 25240 Erzurum (Turkey)

    2011-02-15

    Human tissues with endometriosis have been analyzed in terms of energy absorption (EABF) and exposure (EBF) buildup factors using the five-parameter geometric progression (G-P) fitting formula in the energy region 0.015-15 MeV up to a penetration depth of 40 mfp (mean free path). Chemical compositions of the tissue samples were determined using a wavelength dispersive X-ray fluorescence spectrometer (WDXRFS). Possible conclusions were drawn due to significant variations in EABF and EBF for the selected tissues when photon energy, penetration depth and chemical composition changed. Buildup factors so obtained may be of use when the method of choice for treatment of endometriosis is radiotherapy.

  11. Analysis of chromosomal abnormalities: a study of partial exposure to X-rays

    International Nuclear Information System (INIS)

    Andrade, Aida M.G. de; Mendes, Mariana E.; Mendonça, Julyanne C.G.; Melo, Laís; Hwang, Suy; Santos, Neide; Lima, Fabiana F. de; Centro Regional de Ciências Nucleares; Universidade Federal de Pernambuco

    2017-01-01

    Biological dosimetry is used in case of supposed accidental overexposure. The most commonly used biomarkers for assessing the absorbed dose are unstable chromosomal abnormalities. In a case of a partial body exposure, the frequencies of those abnormalities varies according to the area of the exposed body and may be substantially different from a total exposure of the body with an identical dose. The present study aimed to evaluate the frequency of chromosomal changes simulating, with blood samples, partial (25%, 50%) and full body irradiation (100%) in X-ray beam. The irradiation was performed at Metrology Service (CRCN-NE / CNEN) with a bundle of 250kVp X-rays, resulting in the absorbed dose of 1.0 Gy. Prior to obtain the metaphases, irradiated blood was mixed with non-irradiated blood, and then the mitotic metaphases for the chromosomal analyzes were obtained by culturing lymphocytes and the slides were stained with 5% Giemsa. It was observed that there was an increase in dicentric frequency when the dose percentage increases in both subjects (0.024 and 0.049 in subject 1 and 0.016 and 0.038 in subject 2) after irradiation. The cellular distribution was 'contaminated' only at dose 25% of the first individual who had a prolongation of the distribution. The Qdr and Dolphin methods were used to estimate partial absorbed dose, but the Qdr method was not efficient and whereas the Dolphin method was efficient when the individual had a prolonged cell distribution. It is necessary to increase the number of observations to be sure of the observed behaviors. (author)

  12. Analysis of chromosomal abnormalities: a study of partial exposure to X-rays

    Energy Technology Data Exchange (ETDEWEB)

    Andrade, Aida M.G. de; Mendes, Mariana E.; Mendonça, Julyanne C.G.; Melo, Laís; Hwang, Suy; Santos, Neide; Lima, Fabiana F. de, E-mail: aidamgandrade@gmail.com [Universidade Federal de Pernambuco (UFPE), Recife (Brazil); Centro Regional de Ciências Nucleares (CRCN-NE/CNEN-PE), Recife, PE (Brazil); Universidade Federal de Pernambuco (UFPE),Recife (Brazil). Centro de Biociências. Departamento de Genética

    2017-11-01

    Biological dosimetry is used in case of supposed accidental overexposure. The most commonly used biomarkers for assessing the absorbed dose are unstable chromosomal abnormalities. In a case of a partial body exposure, the frequencies of those abnormalities varies according to the area of the exposed body and may be substantially different from a total exposure of the body with an identical dose. The present study aimed to evaluate the frequency of chromosomal changes simulating, with blood samples, partial (25%, 50%) and full body irradiation (100%) in X-ray beam. The irradiation was performed at Metrology Service (CRCN-NE / CNEN) with a bundle of 250kVp X-rays, resulting in the absorbed dose of 1.0 Gy. Prior to obtain the metaphases, irradiated blood was mixed with non-irradiated blood, and then the mitotic metaphases for the chromosomal analyzes were obtained by culturing lymphocytes and the slides were stained with 5% Giemsa. It was observed that there was an increase in dicentric frequency when the dose percentage increases in both subjects (0.024 and 0.049 in subject 1 and 0.016 and 0.038 in subject 2) after irradiation. The cellular distribution was 'contaminated' only at dose 25% of the first individual who had a prolongation of the distribution. The Qdr and Dolphin methods were used to estimate partial absorbed dose, but the Qdr method was not efficient and whereas the Dolphin method was efficient when the individual had a prolonged cell distribution. It is necessary to increase the number of observations to be sure of the observed behaviors. (author)

  13. Care and supportive measures in school-aged children with prenatal substance exposure.

    Science.gov (United States)

    Sandtorv, Lisbeth B; Haugland, Siren; Elgen, Irene

    2017-12-01

    Prenatal exposure to substances, including alcohol, opiates, and a number of illicit drugs, may have a negative impact on fetal development. Studies have shown that substance exposure can influence a child's neurodevelopment and the need for care and supportive measures. In this study, we aimed to investigate the care status and the level of supportive measures in school-aged children prenatally exposed to alcohol and other substances. This study included children aged between 6 and 14 years who were referred to Haukeland University Hospital in Norway with developmental impairment and a history of prenatal substance exposure. Participants were classified according to their main prenatal exposure to either alcohol or other substances. Information on care status and supportive measures was obtained from medical records and participants' caregivers. We also compared the use of supportive measures for children placed into foster care before and after 1 year of age. A total of 111 (87% of 128 referrals) eligible children participated in the study. Of these 111 children, 96 (86%) were in foster care, of whom 29 (30%) were placed into foster care during their first year of life and 83 out of 90 (92%) had supportive measures, including reinforced foster care and school or social support. A high proportion of the sample lived in foster care and received supportive measures. Findings may reflect an increased need of care and support in school-aged children with prenatal substance exposure, highlighting the importance of awareness among caregivers and public agencies.

  14. Radiation exposure of the UK population from medical and dental x-ray examinations

    International Nuclear Information System (INIS)

    Hart, D.; Wall, B.F.

    2002-03-01

    Knowledge of recent trends in the radiation doses from x-ray examinations and their distribution for the UK population provides useful guidance on where best to concentrate efforts on patient dose reduction in order to optimise the protection of the population in a cost-effective manner. In this report, the results of a recent survey of the frequency of medical and dental x-ray examinations in the UK and contemporary data on the radiation doses typically received by patients, are used to assess trends in the extent and the pattern of the population exposure. Individual patient doses, expressed in terms of the effective dose, range from a few microsieverts for simple radiographic examinations of the teeth, limbs or chest to tens of millisieverts for prolonged fluoroscopic procedures or some computed tomography (CT) examinations. A total of about 41.5 million medical and dental x-ray examinations are now conducted each year in the UK (0.70 examination per head of population) resulting in an annual per caput effective dose of 330 μSv. This is not significantly different from the previous rough estimate of 350 μSv for 1991. However, over the last ten years CT has more than doubled its contribution and is now responsible for 40% of the total dose to the population from medical x-rays. In contrast, the contribution from conventional radiographic and fluoroscopic examinations has nearly halved to about 44%. Interventional and angiographic procedures together contribute the remaining 16%. The annual per caput dose of 330 μSv is low in comparison with other countries having similarly developed systems of health care. This is due to both a lower frequency of x-ray examinations per head of population and generally lower doses in the UK than in other developed countries. However, the much increased contributions of CT, angiography and interventional procedures to the UK population dose indicate an urgent need to develop radiation protection and optimisation activities for

  15. Cosmic ray exposure dating with in situ produced cosmogenic 3He: results from young Hawaiian lava flows

    Science.gov (United States)

    Kurz, M.D.; Colodner, D.; Trull, T.W.; Moore, R.B.; O'Brien, K.

    1990-01-01

    In an effort to determine the in situ production rate of spallation-produced cosmogenic 3He, and evaluate its use as a surface exposure chronometer, we have measured cosmogenic helium contents in a suite of Hawaiian radiocarbon-dated lava flows. The lava flows, ranging in age from 600 to 13,000 years, were collected from Hualalai and Mauna Loa volcanoes on the island of Hawaii. Because cosmic ray surface-exposure dating requires the complete absence of erosion or soil cover, these lava flows were selected specifically for this purpose. The 3He production rate, measured within olivine phenocrysts, was found to vary significantly, ranging from 47 to 150 atoms g-1 yr-1 (normalized to sea level). Although there is considerable scatter in the data, the samples younger than 10,000 years are well-preserved and exposed, and the production rate variations are therefore not related to erosion or soil cover. Data averaged over the past 2000 years indicate a sea-level 3He production rate of 125 ?? 30 atoms g-1 yr-1, which agrees well with previous estimates. The longer record suggests a minimum in sea level normalized 3He production rate between 2000 and 7000 years (55 ?? 15 atoms g-1 yr-1), as compared to samples younger than 2000 years (125 ?? 30 atoms g-1 yr-1), and those between 7000 and 10,000 years (127 ?? 19 atoms g-1 yr-1). The minimum in production rate is similar in age to that which would be produced by variations in geomagnetic field strength, as indicated by archeomagnetic data. However, the production rate variations (a factor of 2.3 ?? 0.8) are poorly determined due to the large uncertainties in the youngest samples and questions of surface preservation for the older samples. Calculations using the atmospheric production model of O'Brien (1979) [35], and the method of Lal and Peters (1967) [11], predict smaller production rate variations for similar variation in dipole moment (a factor of 1.15-1.65). Because the production rate variations, archeomagnetic data

  16. Determination of gamma-ray exposure rate from short-lived fission products under criticality accident conditions

    International Nuclear Information System (INIS)

    Yanagisawa, Hiroshi; Ohno, Akio; Aizawa, Eijyu

    2002-01-01

    For the assessment of γ-ray doses from short-lived fission products (FPs) under criticality accident conditions, γ-ray exposure rates varying with time were experimentally determined in the Transient Experiment Critical Facility (TRACY). The data were obtained by reactivity insertion in the range of 1.50 to 2.93$. It was clarified from the experiments that the contribution of γ-ray from short-lived FPs to total exposure during the experiments was evaluated to be 15 to 17%. Hence, the contribution cannot be neglected for the assessment of γ-ray doses under criticality accident conditions. Computational analyses also indicated that γ-ray exposure rates from short-lived FPs calculated with the Monte Carlo code, MCNP4B, and photon sources based on the latest FP decay data, the JENDL FP Decay Data File 2000, well agreed with the experimental results. The exposure rates were, however, extremely underestimated when the photon sources were obtained by the ORIGEN2 code. The underestimation is due to lack of energy-dependent photon emission data for major short-lived FP nuclides in the photon database attached to the ORIGEN2 code. It was also confirmed that the underestimation arose in 1,000 or less of time lapse after an initial power burst. (author)

  17. Modulation of expression of genes encoding nuclear proteins following exposure to JANUS neutrons or γ-rays

    International Nuclear Information System (INIS)

    Woloschak, G.E.; Chang-Liu, Chin-Mei

    1994-01-01

    Previous work has shown that exposure of cells to ionizing radiations causes modulation of a variety of genes, including those encoding c-fos, interleukin-1, tumor necrosis factor, cytoskeletal elements, and many more. The experiments reported herein were designed to examine the effects of either JANUS neutron or γ-ray exposure on expression of genes encoding nucleus-associated proteins (H4-histone, c-jun, c-myc, Rb, and p53). Cycling Syrian hamster embryo cells were irradiated with varying doses and dose rates of either JANUS fission-spectrum neutrons or γ-rays; after incubation of the cell cultures for 1 h following radiation exposure, mRNA was harvested and analyzed by Northern blot. Results revealed induction of transcripts for c-jun, H4-histone, and Rb following γ-ray but not following neutron exposure. Interestingly, expression of c-myc was repressed following γ-ray but not following neutron exposure. Radiations at different doses and dose rates were compared for each of the genes studied

  18. Biological dose estimation for accidental supra-high dose gamma-ray exposure

    International Nuclear Information System (INIS)

    Chen, Y.; Yan, X.K.; Du, J.; Wang, Z.D.; Zhang, X.Q.; Zeng, F.G.; Zhou, P.K.

    2011-01-01

    To correctly estimate the biological dose of victims accidentally exposed to a very high dose of 60 Co gamma-ray, a new dose-effect curve of chromosomal dicentrics/multicentrics and rings in the supra-high dose range was established. Peripheral blood from two healthy men was irradiated in vitro with doses of 60 Co gamma-rays ranging from 6 to 22 Gy at a dose rate of 2.0 Gy/min. Lymphocytes were concentrated, cultured and harvested at 52 h, 68 h and 72 h. The numbers of dic + r were counted. The dose-effect curves were established and validated using comparisons with doses from the Tokai-mura accident and were then applied to two victims of supra-high dose exposure accident. The results indicated that there were no significant differences in chromosome aberration frequency among the different culture times from 52 h to 72 h. The 6-22 Gy dose-effect curve was fitted to a linear quadratic model Y = -2.269 + 0.776D - 7.868 x l0 -3 D 2 . Using this mathematic model, the dose estimates were similar to data from Tokai-mura which were estimated by PCC ring. Whole body average doses of 9.7 Gy and 18.1 Gy for two victims in the Jining accident were satisfactorily given. We established and successfully applied a new dose-effect curve of chromosomal dicentrics plus ring (dic + r) after 6-22 Gy γ-irradiation from a supra-high dose 60 Co gamma-ray accident.

  19. Intrauterine and early postnatal exposure to outdoor air pollution and lung function at preschool age.

    Science.gov (United States)

    Morales, Eva; Garcia-Esteban, Raquel; de la Cruz, Oscar Asensio; Basterrechea, Mikel; Lertxundi, Aitana; de Dicastillo, Maria D Martinez López; Zabaleta, Carlos; Sunyer, Jordi

    2015-01-01

    Effects of prenatal and postnatal exposure to air pollution on lung function at preschool age remain unexplored. We examined the association of exposure to air pollution during specific trimesters of pregnancy and postnatal life with lung function in preschoolers. Lung function was assessed with spirometry in preschoolers aged 4.5 years (n=620) participating in the INfancia y Medio Ambiente (INMA) cohort. Temporally adjusted land use regression (LUR) models were applied to estimate individual residential exposures to benzene and nitrogen dioxide (NO₂) during specific trimesters of pregnancy and early postnatal life (the first year of life). Recent and current (1 year and 1 week before lung function testing, respectively) exposures to NO₂ and nitrogen oxides (NOx) were also assessed. Exposure to higher levels of benzene and NO₂ during pregnancy was associated with reduced lung function. FEV1 estimates for an IQR increase in exposures during the second trimester of pregnancy were -18.4 mL, 95% CI -34.8 to -2.1 for benzene and -28.0 mL, 95% CI -52.9 to -3.2 for NO₂. Relative risk (RR) of low lung function (<80% of predicted FEV1) for an IQR increase in benzene and NO₂ during the second trimester of pregnancy were 1.22, 95% CI 1.02 to 1.46 and 1.30, 95% CI 0.97 to 1.76, respectively. Associations for early postnatal, recent and current exposures were not statistically significant. Stronger associations appeared among allergic children and those of lower social class. Prenatal exposure to residential traffic-related air pollution may result in long-term lung function deficits at preschool age. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

  20. Low-dose CT of the paranasal sinuses. Minimizing X-ray exposure with spectral shaping

    Energy Technology Data Exchange (ETDEWEB)

    Wuest, Wolfgang [Friedrich-Alexander-University Erlangen-Nuremberg, Radiological Institute, Erlangen (Germany); Radiological Institute, Erlangen (Germany); May, Matthias; Saake, Marc; Brand, Michael; Uder, Michael; Lell, Michael [Friedrich-Alexander-University Erlangen-Nuremberg, Radiological Institute, Erlangen (Germany)

    2016-11-15

    Shaping the energy spectrum of the X-ray beam has been shown to be beneficial in low-dose CT. This study's aim was to investigate dose and image quality of tin filtration at 100 kV for pre-operative planning in low-dose paranasal CT imaging in a large patient cohort. In a prospective trial, 129 patients were included. 64 patients were randomly assigned to the study protocol (100 kV with additional tin filtration, 150mAs, 192 x 0.6-mm slice collimation) and 65 patients to the standard low-dose protocol (100 kV, 50mAs, 128 x 0.6-mm slice collimation). To assess the image quality, subjective parameters were evaluated using a five-point scale. This scale was applied on overall image quality and contour delineation of critical anatomical structures. All scans were of diagnostic image quality. Bony structures were of good diagnostic image quality in both groups, soft tissues were of sufficient diagnostic image quality in the study group because of a high level of noise. Radiation exposure was very low in both groups, but significantly lower in the study group (CTDI{sub vol} 1.2 mGy vs. 4.4 mGy, p < 0.001). Spectral optimization (tin filtration at 100 kV) allows for visualization of the paranasal sinus with sufficient image quality at a very low radiation exposure. (orig.)

  1. Radiation exposure of medical staff from interventional x-ray procedures: a multicentre study

    International Nuclear Information System (INIS)

    Haeusler, Uwe; Brix, Gunnar; Czarwinski, Renate

    2009-01-01

    The purpose of this study was to analyse the radiation exposure of medical staff from interventional x-ray procedures. Partial-body dose measurements were performed with thermoluminescent dosimeters (TLD) in 39 physicians and nine assistants conducting 73 interventional procedures of nine different types in 14 hospitals in Germany. Fluoroscopy time and the dose-area product (DAP) were recorded too. The median (maximum) equivalent body dose per procedure was 16 (2,500) μSv for an unshielded person; the partial-body dose per procedure was 2.8 (240) μSv to the eye lens, 4.1 (730) μSv to the thyroid, 44 (1,800) μSv to one of the feet and 75 (13,000) μSv to one of the hands. A weak correlation between fluoroscopy time or DAP and the mean TLD dose was observed. Generally, the doses were within an acceptable range from a radiation hygiene point of view. However, relatively high exposures were measured to the hand in some cases and could cause a partial-body dose above the annual dose limit of 500 mSv. Thus, the use of finger dosimeters is strongly recommended. (orig.)

  2. New results regarding gonadal exposure in urologic X-ray diagnostics

    International Nuclear Information System (INIS)

    Barke, R.

    1977-01-01

    In a dosimetric study the radiation exposure of the gonads of 130 patients is determined with condenser ionization chambers in applying intravenous urography according to the valid examination standard of the Society of Medical radiology of the GDR. Shielding the gonads with 2 mm lead equivalent the gonad dose of men is less than 30 mrem, but more than 850 mrem without shielding. The gonad dose of women computationally determined from measurements of the surface dose, is about 1,200 mrem. As the radiation exposure due to each individual radiograph was recorded, the influencing factors (film size, distance of the lower field margin from the gonads) can be determined. For the statistically significant correlation between body weight and gonad dose regression equations are given which, with standard X-ray examinations, make it possible to calculate the gonad dose for the individual case with a high degree of certainty. The analysis of intravenous urographic examinations shows that there is a greater share of female patients because this type of examination is often used as an additional diagnostic procedure in case of gynaecologic diseases. Problems of exact dosimetry at the ovary can hardly be solved

  3. Comparison of gamma-ray exposure rate measurements at Bikini Atoll

    International Nuclear Information System (INIS)

    Gudiksen, P.H.; Crites, T.R.

    1975-01-01

    A radiological survey of Bikini and Eneu Islands of the Bikini Atoll was conducted during June 1975 to assess the potential radiation doses that may be received by the returning Bikinians. Bikini Atoll was one of the U.S. nuclear weapons testing sites in the Pacific. An integral part of the survey included measurements of the gamma-ray exposure rates at 1 m above the ground with portable NaI instruments at nearly 2700 locations on the two islands. For comparison purposes, similar measurements were made with a pressurized ion chamber at approximately 200 locations, and with LiF and CaF 2 :Dy thermoluminescent dosimeters (TLDs) at 80 locations. The results indicate that the NaI scintillators overresponded because of their nonlinear energy characteristics. The responses of the LiF dosimeters and the pressurized ion chamber agreed to within 13 percent. Attenuation studies with LiF TLDs indicated that roughly 25 percent of the total free air exposure rate at 1 m was due to beta radiation

  4. Exposure to aged crumb rubber reduces survival time during a stress test in earthworms (Eisenia fetida).

    Science.gov (United States)

    Pochron, Sharon; Nikakis, Jacqueline; Illuzzi, Kyra; Baatz, Andrea; Demirciyan, Loriana; Dhillon, Amritjot; Gaylor, Thomas; Manganaro, Alexa; Maritato, Nicholas; Moawad, Michael; Singh, Rajwinder; Tucker, Clara; Vaughan, Daniel

    2018-04-01

    Solid waste management struggles with the sustainable disposal of used tires. One solution involves shredding used tires into crumb rubber and using the material as infill for artificial turf. However, crumb rubber contains hydrocarbons, organic compounds, and heavy metals, and it travels into the environment. Earthworms living in soil contaminated with virgin crumb rubber gained 14% less body weight than did earthworms living in uncontaminated soil, but the impact of aged crumb rubber on the earthworms is unknown. Since many athletic fields contain aged crumb rubber, we compared the body weight, survivorship, and longevity in heat and light stress for earthworms living in clean topsoil to those living in topsoil contaminated with aged crumb rubber. We also characterized levels of metals, nutrients, and micronutrients of both soil treatments and compared those to published values for soil contaminated with virgin crumb rubber. Consistent with earlier research, we found that contaminated soil did not inhibit microbial respiration rates. Aged crumb rubber, like new crumb rubber, had high levels of zinc. However, while exposure to aged crumb rubber did not reduce earthworm body weight as did exposure to new crumb rubber, exposure to aged crumb rubber reduced earthworm survival time during a stress test by a statistically significant 38 min (16.2%) relative to the survival time for worms that had lived in clean soil. Aged crumb rubber and new crumb rubber appear to pose similar toxic risks to earthworms. This study suggests an environmental cost associated with the current tire-recycling solution.

  5. [Effective Techniques to Reduce Radiation Exposure to Medical Staff during Assist of X-ray Computed Tomography Examination].

    Science.gov (United States)

    Miyajima, Ryuichi; Fujibuchi, Toshioh; Miyachi, Yusuke; Tateishi, Satoshi; Uno, Yoshinori; Amakawa, Kazutoshi; Ohura, Hiroki; Orita, Shinichi

    2018-01-01

    Medical staffs like radiological technologists, doctors, and nurses are at an increased risk of exposure to radiation while assisting the patient in a position or monitor contrast medium injection during computed tomography (CT). However, methods to protect medical staff from radiation exposure and protocols for using radiological protection equipment have not been standardized and differ among hospitals. In this study, the distribution of scattered X-rays in a CT room was measured by placing electronic personal dosimeters in locations where medical staff stands beside the CT scanner gantry while assisting the patient and the exposure dose was measured. Moreover, we evaluated non-uniform exposure and revealed effective techniques to reduce the exposure dose to medical staff during CT. The dose of the scattered X-rays was the lowest at the gantry and at the examination table during both head and abdominal CT. The dose was the highest at the trunk of the upper body of the operator corresponding to a height of 130 cm during head CT and at the head corresponding to a height of 150 cm during abdominal CT. The maximum dose to the crystalline lens was approximately 600 μSv during head CT. We found that the use of volumetric CT scanning and X-ray protective goggles, and face direction toward the gantry reduced the exposure dose, particularly to the crystalline lens, for which lower equivalent dose during CT scan has been recently recommended in the International Commission on Radiological Protection Publication 118.

  6. Inquiry on the radiation exposure of the Swiss population by X-ray diagnosis

    International Nuclear Information System (INIS)

    Poretti, G.G.; Bern Univ.; Jonesco-Farca, F.; Lanz, W.

    1976-01-01

    The genetic load on a population is usually expressed in terms of the so-called 'Genetically Significant Dose' (GSD), i.e. the dose which, averaged over the total population, produces the same results as the varying amounts of radiation received in reality by the individuals making up the population. It may be calculated taking into account the following parameters: 1) total number of male and female persons in the population per age group, including the foetuses, 2) average expectation of children per person, 3) number of persons having received a certain type of X-ray examination, and 4) experimental gonadal dose for this examination (for men, women and foetuses - not to be confused with the GSD). The GSD of the Swiss population for the year 1971 was calculated per age group on the basis of physicians' data on some 60,000 patients. The gonadal dose was determined experimentally in various hospitals by means of TLD dosimeters, sensitive high-pressure ionization chambers and normal chambers. The computer programme to calculate the GSD (PL/1 language) is very time-consuming, but its structure allows a new selective investigation to be made later on by merely changing the input. The results show that in Switzerland as in other countries there is a 3-4% increase per year in X-ray examinations for diagnostic purposes. The GSD for 1971 is 42-43 mrad per person in Switzerland as compared to 22 mrad for 1957. The GSD percentage is about 57% for men, about 35% for women and about 8% for foetuses. The number of X-ray examinations is almost equal for general practitioners (53.8%) and hospitals (46.2%). (orig.) [de

  7. Effect of continuous gamma-ray exposure on performance of learned tasks and effect of subsequent fractionated exposures on blood-forming tissue

    Science.gov (United States)

    Spalding, J. F.; Holland, L. M.; Prine, J. R.; Farrer, D. N.; Braun, R. G.

    1972-01-01

    Sixteen monkeys trained to perform continuous and discrete-avoidance and fixed-ratio tasks with visual and auditory cues were performance-tested before, during, and after 10-day gamma-ray exposures totaling 0, 500, 750, and 1000 rads. Approximately 14 months after the performance-test exposures, surviving animals were exposed to 100-rad gamma-ray fractions at 56-day intervals to observe injury and recovery patterns of blood-forming tissues. The fixed-ratio, food-reward task performance showed a transient decline in all dose groups within 24 hours of the start of gamma-ray exposure, followed by recovery to normal food-consumption levels within 48 to 72 hours. Avoidance tasks were performed successfully by all groups during the 10-day exposure, but reaction times of the two higher dose-rate groups in which animals received 3 and 4 rads per hour or total doses of 750 and 1000 rads, respectively, were somewhat slower.

  8. Age-Specific Associations Between Violence Exposure and Past 30-Day Marijuana and Alcohol Use.

    Science.gov (United States)

    Goldstick, Jason E; Heinze, Justin E; Stoddard, Sarah A; Cunningham, Rebecca M; Zimmerman, Marc A

    2018-04-23

    Using data from a cohort study of students at risk for high school dropout, we examined associations between violence exposure and past 30-day alcohol and marijuana use. We used varying-coefficient regression with person-level fixed effects to estimate how those associations changed within-person across ages approximately 14-23. Generally, violence perpetration was most strongly associated with substance use, within-person. Substance use became increasingly associated with both observed violence and violence perpetration during early/middle adolescence; this increase continued longer into development (age 18+) for alcohol use. Across most of the age range studied here, violence victimization was minimally associated with within-person changes in substance use. Results indicate age-specific associations between violence exposure and alcohol and other drug use, which may be useful for informing prevention strategies. © 2018 Society for Research on Adolescence.

  9. Alcohol Advertising Exposure Among Middle School–Age Youth: An Assessment Across All Media and Venues

    Science.gov (United States)

    Collins, Rebecca L.; Martino, Steven C.; Kovalchik, Stephanie A.; Becker, Kirsten M.; Shadel, William G.; D’Amico, Elizabeth J.

    2016-01-01

    Objective: The purpose of this study was to quantify middle school youth’s exposure to alcohol advertisements across media and venues, determine venues of greatest exposure, and identify characteristics of youth who are most exposed. Method: Over a 10-month period in 2013, 589 Los Angeles–area youth ages 11–14 from diverse racial/ethnic backgrounds completed a short paper-and-pencil survey assessing background characteristics and then participated in a 14-day ecological momentary assessment, logging all exposures to alcohol advertisements on handheld computers as they occurred. Results: African American and Hispanic youth were exposed to an average of 4.1 and 3.4 advertisements per day, respectively, nearly two times as many as non-Hispanic White youth, who were exposed to 2.0 advertisements per day. Girls were exposed to 30% more advertisements than boys. Most exposures were to outdoor advertisements, with television advertisements a close second. Conclusions: Exposure to alcohol advertising is frequent among middle school–age youth and may put them at risk for earlier or more frequent underage drinking. Greater restrictions on alcohol advertising outdoors and on television should be considered by regulators and by the alcohol industry and should focus particularly on reducing exposure among minority youth. PMID:27172570

  10. Alcohol Advertising Exposure Among Middle School-Age Youth: An Assessment Across All Media and Venues.

    Science.gov (United States)

    Collins, Rebecca L; Martino, Steven C; Kovalchik, Stephanie A; Becker, Kirsten M; Shadel, William G; D'Amico, Elizabeth J

    2016-05-01

    The purpose of this study was to quantify middle school youth's exposure to alcohol advertisements across media and venues, determine venues of greatest exposure, and identify characteristics of youth who are most exposed. Over a 10-month period in 2013, 589 Los Angeles-area youth ages 11-14 from diverse racial/ethnic backgrounds completed a short paper-and-pencil survey assessing background characteristics and then participated in a 14-day ecological momentary assessment, logging all exposures to alcohol advertisements on handheld computers as they occurred. African American and Hispanic youth were exposed to an average of 4.1 and 3.4 advertisements per day, respectively, nearly two times as many as non-Hispanic White youth, who were exposed to 2.0 advertisements per day. Girls were exposed to 30% more advertisements than boys. Most exposures were to outdoor advertisements, with television advertisements a close second. Exposure to alcohol advertising is frequent among middle school-age youth and may put them at risk for earlier or more frequent underage drinking. Greater restrictions on alcohol advertising outdoors and on television should be considered by regulators and by the alcohol industry and should focus particularly on reducing exposure among minority youth.

  11. THE AGES OF HIGH-MASS X-RAY BINARIES IN NGC 2403 AND NGC 300

    Energy Technology Data Exchange (ETDEWEB)

    Williams, Benjamin F.; Binder, Breanna A.; Dalcanton, Julianne J. [Department of Astronomy, Box 351580, University of Washington, Seattle, WA 98195 (United States); Eracleous, Michael [Department of Astronomy and Astrophysics and Center for Gravitational Wave Physics, Pennsylvania State University, 525 Davey Lab, University Park, PA 16803 (United States); Dolphin, Andrew, E-mail: ben@astro.washington.edu, E-mail: bbinder@astro.washington.edu, E-mail: jd@astro.washington.edu, E-mail: mce@astro.psu.edu, E-mail: adolphin@raytheon.com [Raytheon Company, Tucson, AZ 85734 (United States)

    2013-07-20

    We have examined resolved stellar photometry from HST imaging surrounding 18 high-mass X-ray binary (HMXB) candidates in NGC 300 and NGC 2403 as determined from combined Chandra/HST analysis. We have fit the color-magnitude distribution of the surrounding stars with stellar evolution models. All but one region in NGC 300 and two in NGC 2403 contain a population with an age between 20 and 70 Myr. One of the candidates is the ultraluminous X-ray source in NGC 2403, which we associate with a 60 {+-} 5 Myr old population. These age distributions provide additional evidence that 16 of these 18 candidates are HMXBs. Furthermore, our results suggest that the most common HMXB age in these galaxies is 40-55 Myr. This preferred age is similar to observations of HMXBs in the Small Magellanic Cloud, providing new evidence of this formation timescale, but in higher metallicity populations. We suggest that this preferred HMXB age is the result of the fortuitous combination of two physical effects. First, this is the age of a population when the greatest rate of core-collapse events should be occurring, maximizing neutron star production. Second, this is the age when B stars are most likely to be actively losing mass. We also discuss our results in the context of HMXB feedback in galaxies, confirming HMXBs as a potentially important source of energy for the interstellar medium in low-mass galaxies.

  12. Neurobehavioral deficits at age 7years associated with prenatal exposure to toxicants from maternal seafood diet

    DEFF Research Database (Denmark)

    Grandjean, Philippe; Weihe, Pal; Nielsen, Flemming

    2012-01-01

    To determine the possible neurotoxic impact of prenatal exposure to polychlorinated biphenyls (PCBs), we analyzed banked cord blood from a Faroese birth cohort for PCBs. The subjects were born in 1986-1987, and 917 cohort members had completed a series of neuropsychological tests at age 7years. M...

  13. HISTORY OF SUNLIGHT EXPOSURE IS A RISK FACTOR FOR AGE-RELATED MACULAR DEGENERATION

    NARCIS (Netherlands)

    Schick, T.; Ersoy, L.; Lechanteur, Y.T.; Saksens, N.T.; Hoyng, C.B.; Hollander, A.I. den; Kirchhof, B.; Fauser, S.

    2016-01-01

    PURPOSE: To evaluate effects of current and past sunlight exposure and iris color on early and late age-related macular degeneration (AMD). METHODS: Of 3,701 individuals from the EUGENDA database, 752 (20.3%) showed early AMD, 1,179 (31.9%) late AMD, and 1,770 (47.8%) were controls. Information

  14. A Case Series of Marijuana Exposures in Pediatric Patients Less than 5 Years of Age

    Science.gov (United States)

    Wang, George Sam; Narang, Sandeep K.; Wells, Kathryn; Chuang, Ryan

    2011-01-01

    Objective: In Colorado, there has been a large increase in medical marijuana dispensaries and licenses for the use of medical marijuana over the past year. This is a retrospective case series of marijuana exposures that have presented to the emergency department (ED) in children less than 5 years of age. Methods: We performed a retrospective chart…

  15. Exposure to perfluoroalkyl substances during pregnancy and child behaviour at 5 to 9years of age

    DEFF Research Database (Denmark)

    Høyer, Birgit Bjerre; Bonde, Jens Peter; Ramlau-Hansen, Cecilia Høst

    2017-01-01

    We examined associations between prenatal exposure to perfluorohexane sulfonic acid (PFHxS), perfluoroheptanoic acid (PFHpA), perfluorononanoic acid (PFNA), and perfluorodecanic acid (PFDA) - and child behaviour (SDQ-total) and hyperactivity (sub-scale) at 5-9years of age in birth cohorts from Gr...

  16. TOXICITY PATHWAY ANALYSIS IN AGING BROWN NORWAY RAT BRAIN FOLLOWING ACUTE TOLUENE EXPOSURE

    Science.gov (United States)

    The influence of aging on susceptibility to environmental stressors is poorly understood. To investigate the contribution of different life stages on response to toxicants, we examined the effects of acute exposure by oral gavage of the volatile organic solvent toluene (0.00, 0.3...

  17. Fabrication of open-top microchannel plate using deep X-ray exposure mask made with silicon on insulator substrate

    CERN Document Server

    Fujimura, T; Etoh, S I; Hattori, R; Kuroki, Y; Chang, S S

    2003-01-01

    We propose a high-aspect-ratio open-top microchannel plate structure. This type of microchannel plate has many advantages in electrophoresis. The plate was fabricated by deep X-ray lithography using synchrotron radiation (SR) light and the chemical wet etching process. A deep X-ray exposure mask was fabricated with a silicon on insulator (SOI) substrate. The patterned Si microstructure was micromachined into a thin Si membrane and a thick Au X-ray absorber was embedded in it by electroplating. A plastic material, polymethylmethacrylate (PMMA) was used for the plate substrate. For reduction of the exposure time and high-aspect-ratio fast wet development, the fabrication condition was optimized with respect to not the exposure dose but to the PMMA mean molecular weight (M.W.) changing after deep X-ray exposure as measured by gel permeation chromatography (GPC). Decrement of the PMMA M.W. and increment of the wet developer temperature accelerated the etching rate. Under optimized fabrication conditions, a microc...

  18. Disorders of oxidation homeostasis in the blood and organs of rats under the influence of external x-ray exposure

    International Nuclear Information System (INIS)

    Uzlenkova, N.Je.

    2009-01-01

    The study was performed in the blood and organs (lungs and skin) of male rats weighing 160-180 g. Single external x-ray exposure to minimal and medial lethal doses causes stable disorders in oxidation homeostasis resulting in peroxidation state and development of chronic oxidative stress in the organism of the exposed rats.

  19. Radiation-induced signaling results in mitochondrial impairment in mouse heart at 4 weeks after exposure to X-rays.

    Science.gov (United States)

    Barjaktarovic, Zarko; Schmaltz, Dominik; Shyla, Alena; Azimzadeh, Omid; Schulz, Sabine; Haagen, Julia; Dörr, Wolfgang; Sarioglu, Hakan; Schäfer, Alexander; Atkinson, Michael J; Zischka, Hans; Tapio, Soile

    2011-01-01

    Radiation therapy treatment of breast cancer, Hodgkin's disease or childhood cancers expose the heart to high local radiation doses, causing an increased risk of cardiovascular disease in the survivors decades after the treatment. The mechanisms that underlie the radiation damage remain poorly understood so far. Previous data show that impairment of mitochondrial oxidative metabolism is directly linked to the development of cardiovascular disease. In this study, the radiation-induced in vivo effects on cardiac mitochondrial proteome and function were investigated. C57BL/6N mice were exposed to local irradiation of the heart with doses of 0.2 Gy or 2 Gy (X-ray, 200 kV) at the age of eight weeks, the control mice were sham-irradiated. After four weeks the cardiac mitochondria were isolated and tested for proteomic and functional alterations. Two complementary proteomics approaches using both peptide and protein quantification strategies showed radiation-induced deregulation of 25 proteins in total. Three main biological categories were affected: the oxidative phophorylation, the pyruvate metabolism, and the cytoskeletal structure. The mitochondria exposed to high-dose irradiation showed functional impairment reflected as partial deactivation of Complex I (32%) and Complex III (11%), decreased succinate-driven respiratory capacity (13%), increased level of reactive oxygen species and enhanced oxidation of mitochondrial proteins. The changes in the pyruvate metabolism and structural proteins were seen with both low and high radiation doses. This is the first study showing the biological alterations in the murine heart mitochondria several weeks after the exposure to low- and high-dose of ionizing radiation. Our results show that doses, equivalent to a single dose in radiotherapy, cause long-lasting changes in mitochondrial oxidative metabolism and mitochondria-associated cytoskeleton. This prompts us to propose that these first pathological changes lead to an increased

  20. Cognitive deficits at age 22 years associated with prenatal exposure to methylmercury

    DEFF Research Database (Denmark)

    Debes, Frodi; Weihe, Pál; Grandjean, Philippe

    2016-01-01

    methylmercury exposure was assessed in terms of the mercury concentration in cord blood and maternal hair. Clinical examinations of 847 cohort members at age 22 years were carried out in 2008-2009 using a panel of neuropsychological tests that reflected major functional domains. Subjects with neurological...... and psychiatric diagnoses were excluded from the data analysis, thus leaving 814 subjects. Multiple regression analysis included covariates previously identified for adjustment. Deficits in Boston Naming Test (BNT) and other tests of verbal performance were significantly associated with the cord-blood mercury...... to about 2.2 IQ points at a 10-fold increased prenatal methylmercury exposure. Thus, although the cognitive deficits observed were smaller than at examinations at younger ages, maternal diets with contaminated seafood were associated with adverse effects in this birth cohort at age 22 years. The deficits...

  1. Sensorineural Hearing Loss Associated with Occupational Noise Exposure: Effects of Age-Corrections

    Directory of Open Access Journals (Sweden)

    2009-02-01

    Full Text Available Noise-induced permanent threshold shifts (NIPTS were computed from retrospective audiometric analyses by subtracting aging effects on hearing sensitivity in sixty-eight patients with bilateral sensorineural hearing loss who reported significant occupational noise exposure histories. There were significant effects of age on NIPTS but no significant gender- or ear- differences in terms of NIPTS. The NIPTS at 2,000 Hz was found to be significantly greater than NIPTS at frequencies 500 Hz, 1,000 Hz, 4,000 Hz, and 8,000 Hz. Defined noise notches were seen in the audiograms of 38/136 (27% ears with SNHL. Results support models that suggest interactive effects of aging and noise on sensorineural hearing loss in ears with occupational noise exposure.

  2. Sensorineural hearing loss associated with occupational noise exposure: effects of age-corrections.

    Science.gov (United States)

    Krishnamurti, Sridhar

    2009-03-01

    Noise-induced permanent threshold shifts (NIPTS) were computed from retrospective audiometric analyses by subtracting aging effects on hearing sensitivity in sixty-eight patients with bilateral sensorineural hearing loss who reported significant occupational noise exposure histories. There were significant effects of age on NIPTS but no significant gender- or ear- differences in terms of NIPTS. The NIPTS at 2,000 Hz was found to be significantly greater than NIPTS at frequencies 500 Hz, 1,000 Hz, 4,000 Hz, and 8,000 Hz. Defined noise notches were seen in the audiograms of 38/136 (27%) ears with SNHL. Results support models that suggest interactive effects of aging and noise on sensorineural hearing loss in ears with occupational noise exposure.

  3. Evidence from cosmic ray exposure (CRE) dating for the existence of a pre-Minoan caldera on Santorini, Greece

    Science.gov (United States)

    Athanassas, C. D.; Bourlès, D. L.; Braucher, R.; Druitt, T. H.; Nomikou, P.; Léanni, L.

    2016-05-01

    Cosmic ray exposure (CRE) dating was performed on the caldera cliffs of Santorini with the aim of detecting cliff segments predating the Minoan eruption (17th century BCE). The methodology involved the determination of in situ-produced cosmogenic 36Cl concentration in basaltic-to-rhyodacitic whole rocks cropping out in the cliffs. After the samples were processed following the chemical protocol of 36Cl preparation for silicate rocks, 36Cl concentrations were measured by accelerator mass spectrometry (AMS). Important challenges during the implementation procedure were related to large amounts of radiogenic 36Cl, complex modeling of inherited 36Cl, and dominance of the thermal and epithermal (low-energy) neutron capture production pathway. Nevertheless, quantitative assessments on the basis of the contribution of the low-energy neutron capture pathway percent to the total production rate validated the calculated CRE dates. Current CRE ages demonstrate that an ancient caldera existed on pre-Minoan Santorini, occupying at least the northern half of the modern-day caldera.

  4. Exposure to indoor air pollution in a reconstructed house from the Danish Iron Age

    Science.gov (United States)

    Skov, Henrik; Stenholt Christensen, Carsten; Fenger, Jes; Essenbæk, Merete; Larsen, Dyveke; Sørensen, Lasse

    The adverse effects of air pollution on health have been recognised for millennia, but only in recent centuries they have been directly documented. In this paper evidence of the levels of exposure in the Danish Iron Age has been obtained from real measurements. The personal exposure to NO 2 was measured over one week from 6 to 13 February 1999 for a person living in a reconstructed house from the Danish Iron Age (500 BC-700 AD). At the same time NO 2 was measured close to the fireplace and next to the beds as well as outdoor at a distance of about 20 m from the house. Finally, 1 h average concentrations of benzene were measured for a 24 h period during the exposure measurement. A weekly average exposure of NO 2 was measured to be 61.6 μg N m -3. In the house as high as 110.8 μg N m -3 weekly average was measured for NO 2 and a 24 h average value of 45.8 μg m -3 was determined for benzene. The exposure is compared with the present levels.

  5. Isotopic Evidence for Multi-stage Cosmic-ray Exposure Histories of Lunar Meteorites: Long Residence on the Moon and Short Transition to the Earth

    Energy Technology Data Exchange (ETDEWEB)

    Hidaka, Hiroshi; Sakuma, Keisuke [Department of Earth and Planetary Sciences, Nagoya University Nagoya 464-8601 (Japan); Nishiizumi, Kunihiko [Space Sciences Laboratory, University of California, Berkeley, CA 94720-7450 (United States); Yoneda, Shigekazu, E-mail: hidaka@eps.nagoya-u.ac.jp [Department of Science and Engineering, National Museum of Nature and Science Tsukuba 305-0005 (Japan)

    2017-06-01

    It is known that most lunar meteorites have complicated cosmic-ray exposure experiences on the Moon and in space. In this study, cosmic-ray irradiation histories of six lunar meteorites, Dhofar 489, Northwest Africa 032 (NWA 032), NWA 479, NWA 482, NWA 2995, and NWA 5000, were characterized from neutron-captured isotopic shifts of Sm and Gd, and from the abundances of long-lived cosmogenic radionuclides like {sup 10}Be, {sup 26}Al, {sup 36}Cl, and {sup 41}Ca. Sm and Gd isotopic data of all of six meteorites show significant isotopic shifts of {sup 149}Sm–{sup 150}Sm and {sup 157}Gd–{sup 158}Gd caused by accumulation of neutron capture reactions due to cosmic-ray irradiation, corresponding to the neutron fluences of (1.3–9.6) × 10{sup 16} n cm{sup −2}. In particular, very large Sm and Gd isotopic shifts of NWA 482 are over those of a lunar regolith 70002, having the largest isotopic shifts among the Apollo regolith samples, corresponding to cosmic-ray exposure duration over 800 million years in the lunar surface (2 π irradiation). Meanwhile, the concentrations of cosmogenic radionuclides for individual six meteorites show the short irradiation time less than one million years as their bodies in space (4 π irradiation). Our data also support the results of previous studies, revealing that most of lunar meteorites have long exposure ages at shallow depths on the Moon and short transit times from the Moon to the Earth.

  6. Bedtime and evening light exposure influence circadian timing in preschool-age children: A field study

    Directory of Open Access Journals (Sweden)

    Lameese D. Akacem

    2016-11-01

    Full Text Available Light exposure and sleep timing are two factors that influence inter-individual variability in the timing of the human circadian clock. The aim of this study was to quantify the degree to which evening light exposure predicts variance in circadian timing over and above bedtime alone in preschool children. Participants were 21 children ages 4.5–5.0 years (4.7±0.2 years; 9 females. Children followed their typical sleep schedules for 4 days during which time they wore a wrist actigraph to assess sleep timing and a pendant light meter to measure minute-by-minute illuminance levels in lux. On the 5th day, children participated in an in-home dim-light melatonin onset (DLMO assessment. Light exposure in the 2 h before bedtime was averaged and aggregated across the 4 nights preceding the DLMO assessment. Mean DLMO and bedtime were 19:22±01:04 and 20:07±00:46, respectively. Average evening light exposure was 710.1±1418.2 lux. Children with later bedtimes (lights-off time had more delayed melatonin onset times (r=0.61, p=0.002. Evening light exposure was not independently associated with DLMO (r=0.32, p=0.08; however, a partial correlation between evening light exposure and DLMO when controlling for bedtime yielded a positive correlation (r=0.46, p=0.02. Bedtime explained 37.3% of the variance in the timing of DLMO, and evening light exposure accounted for an additional 13.3% of the variance. These findings represent an important step in understanding factors that influence circadian phase in preschool-age children and have implications for understanding a modifiable pathway that may underlie late sleep timing and the development of evening settling problems in early childhood.

  7. Age-related X-ray feature of the spine in patients with achondroplasia

    International Nuclear Information System (INIS)

    Shevtsov, V.I.; D'yachkova, G.V.; Novikova, O.S.

    1999-01-01

    Age-related X-ray features of the spine in patients with achondroplasia are studied. It gives the time course of changes in the shape of vertebrae, the specific features of apophyseal ossification, provides a quantitative account of the shorter caudal lumbar vertebral arch root distance symptom. The time course of changes in the size of the lumbosacral angle was examined. The findings suggest that there are not only considerable static changes in the spine of patients with achondroplasia, but also significant age-related features of vertebral tissue growth and differentiation [ru

  8. Biomarkers of oxidative stress and inflammation after wood smoke exposure in a reconstructed Viking Age house

    DEFF Research Database (Denmark)

    Jensen, Annie; Karottki, Dorina Gabriela; Christensen, Jannie Marie

    2014-01-01

    Exposure to particles from combustion of wood is associated with respiratory symptoms, whereas there is limited knowledge about systemic effects. We investigated effects on systemic inflammation, oxidative stress and DNA damage in humans who lived in a reconstructed Viking Age house, with indoor...... expression levels of CD11b, CD49d, and CD62L on monocytes after the stay in the house. In conclusion, even a high inhalation exposure to wood smoke was associated with limited systemic effects on markers of oxidative stress, DNA damage, inflammation, and monocyte activation....

  9. Early-Life Phthalate Exposure and Adiposity at 8 Years of Age.

    Science.gov (United States)

    Shoaff, Jessica; Papandonatos, George D; Calafat, Antonia M; Ye, Xiaoyun; Chen, Aimin; Lanphear, Bruce P; Yolton, Kimberly; Braun, Joseph M

    2017-09-11

    Early-life phthalate exposure may influence child adiposity, but prior studies have not determined if there are periods of enhanced vulnerability to phthalates. To examine the relationship between child adiposity at 8 y of age and repeated urinary biomarkers of phthalate exposure from gestation through childhood to determine if there are distinct periods of vulnerability. In 219 mother-child pairs from Cincinnati, Ohio, we quantified nine urinary phthalate metabolites up to two times prenatally and six times from 1-8 y of age. We measured child body mass index (BMI), waist circumference, and percent body fat at 8 y of age. To identify periods of vulnerability, we used two statistical methods to estimate phthalate-adiposity associations at each visit, test differences in phthalate-adiposity associations across visits, and model trajectories of phthalate concentrations for children at different levels of adiposity. Prenatal phthalate concentrations were not associated with excess child adiposity. Monobenzyl phthalate (MBzP) concentrations during pregnancy and childhood were inversely associated with adiposity. The associations of di(2-ethylhexyl) phthalate (∑DEHP) metabolites and monoethyl phthalate (MEP) with child adiposity depended on the timing of exposure. A 10-fold increase in ∑DEHP at 1 and 5 y was associated with a 2.7% decrease [95% confidence interval (CI): -4.8, -0.5] and 2.9% increase (95% CI: 0.3, 5.5) in body fat, respectively. MEP concentrations at 5 and 8 y of age were associated with higher child adiposity, but earlier childhood concentrations were not. In this cohort, we did not find evidence of an obesogenic effect of prenatal phthalate exposure. Positive associations between postnatal MEP and ∑DEHP concentrations depended on the timing of exposure. https://doi.org/10.1289/EHP1022.

  10. Application of X-rays to dental age estimation in medico-legal practice

    Directory of Open Access Journals (Sweden)

    Dorota Lorkiewicz-Muszyńska

    2015-05-01

    Full Text Available Aim of the study: The paper addresses the use of dental age assessment methods based on radiographs in medico-legal practice. Different cases of practical application of the methods are presented including identification of human remains, dental age assessment in a living person and one archaeological case. Material and methods : The study material consisted of cases involving dental age assessment performed in the Department of Forensic Medicine, Poznan University of Medical Sciences in Poznan. Depending on the preliminary assessment of age, the Liversidge or the Kvaal et al. methods were applied. Dental age was estimated on the basis of available pantomograms. In the case of the living person, it was a radiograph supplied for expert evaluation. In the other cases, dental computed tomography was performed. Results : Dental age was successfully estimated in all of the cases. Various methods based on the analysis of X-ray images were applied. Dental age was shown to be correlated with skeletal age. Conclusions : The methods based on radiographs were demonstrated to be useful, and the results they yield are fully correlated with results of anthropological analyses.

  11. Application of skeletal age based on x-ray in selecting sports talents

    Science.gov (United States)

    Mao, Zongzhen; Xu, Guodong; Song, Tao

    2012-01-01

    Skeletal age has been studied and proved that for most elite athletes, it was coincident with the chronological ages when they were young. In order to explore the application of skeletal age in selecting sports talent, 32 athletes (female, chronological age 5-12 y) were chosen from the Gymnastics Training Base in this study. Their left hand-wrists were photographed with X-rays, and then the skeletal ages were estimated by Chinese version of the Tanner-Whitehouse Skeletal Maturity Assessment System. At the same time, their body shapes, functions, and sports ability were also measured. Results showed that 71.88% of the skeletal age was proportional to their chronological age (+/- 1 y); while 18.75% of the skeletal maturity was retarded by 1- 2 year, 9.37% of those was advanced more than 1 year. On the other hand, the body shape, functions and sports ability of the athletes were positively related with their skeletal maturity. This study proved that the determination of skeletal maturity is a reliable evaluation for selecting sports talent. A further study on the influence of gymnastics on the skeletal age is of great significance.

  12. Dental X-ray exposure and Alzheimer's disease: a hypothetical etiological association.

    Science.gov (United States)

    Rodgers, Caroline C

    2011-07-01

    Despite the fact that Alzheimer's disease was identified more than 100 years ago, its cause remains elusive. Although the chance of developing Alzheimer's disease increases with age, it is not a natural consequence of aging. This article proposes that dental X-rays can damage microglia telomeres - the structures at the end of chromosomes that determine how many times cells divide before they die - causing them to age prematurely. Degenerated microglia lose their neuroprotective properties, resulting in the formation of neurofibrillary tau tangles and consequently, the neuronal death that causes Alzheimer's dementia. The hypothesis that Alzheimer's is caused specifically by microglia telomere damage would explain the delay of one decade or longer between the presence of Alzheimer's brain pathology and symptoms; telomere damage would not cause any change in microglial function, it would just reset the countdown clock so that senescence and apoptosis occurred earlier than they would have without the environmental insult. Once microglia telomere damage causes premature aging and death, the adjacent neurons are deprived of the physical support, maintenance and nourishment they require to survive. This sequence of events would explain why therapies and vaccines that eliminate amyloid plaques have been unsuccessful in stopping dementia. Regardless of whether clearing plaques is beneficial or harmful - which remains a subject of debate - it does not address the failing microglia population. If microglia telomere damage is causing Alzheimer's disease, self-donated bone marrow or dental pulp stem cell transplants could give rise to new microglia populations that would maintain neuronal health while the original resident microglia population died. Copyright © 2011 Elsevier Ltd. All rights reserved.

  13. Radiofrequency exposure in young and old: different sensitivities in light of age-relevant natural differences.

    Science.gov (United States)

    Redmayne, Mary; Johansson, Olle

    2015-01-01

    Our environment is now permeated by anthropogenic radiofrequency electromagnetic radiation, and individuals of all ages are exposed for most of each 24 h period from transmitting devices. Despite claims that children are more likely to be vulnerable than healthy adults to unwanted effects of this exposure, there has been no recent examination of this, nor of comparative risk to the elderly or ill. We sought to clarify whether research supports the claim of increased risk in specific age-groups. First, we identified the literature which has explored age-specific pathophysiological impacts of RF-EMR. Natural life-span changes relevant to these different impacts provides context for our review of the selected literature, followed by discussion of health and well-being implications. We conclude that age-dependent RF-EMR study results, when considered in the context of developmental stage, indicate increased specific vulnerabilities in the young (fetus to adolescent), the elderly, and those with cancer. There appears to be at least one mechanism other than the known thermal mechanism causing different responses to RF-EMR depending upon the exposure parameters, the cell/physiological process involved, and according to age and health status. As well as personal health and quality-of-life impacts, an ageing population means there are economic implications for public health and policy.

  14. Chronic intermittent exposure to ayahuasca during aging does not affect memory in mice

    Directory of Open Access Journals (Sweden)

    N.F. Correa-Netto

    Full Text Available The Quechua term ayahuasca refers to a beverage obtained from decoctions of the liana Banisteriopsis caapi with leaves of Psychotria viridis. The ritualistic use of ayahuasca is becoming a global phenomenon, with some individuals using this beverage throughout life, including in old age. Cognitive impairment is a common manifestation during aging. There are conflicting reports on the ability of some ayahuasca compounds to exert neuroprotective or neurotoxic effects that could improve or impair learning and memory. Animal models provide a relevant and accessible means of investigating the behavioral effects of ayahuasca without the environmental conditions associated with the ritualistic use of the beverage. In this study, we investigated the influence of chronic ayahuasca exposure throughout aging on the spatial reference and habituation memories of mice. Twenty-eight male c57bl/6 mice (6 months old received ayahuasca or water (1.5 mL/kg, orally twice a week for 12 months and were tested in the Morris water maze (MWM, open field and elevated plus maze (EPM tasks before and after treatment. During aging, there was significant impairment in the evocation (but not acquisition of spatial reference memory and in habituation to the open field. There was also a decrease in locomotor activity in the open field and EPM tests, whereas the anxiety parameters were unaltered. Ayahuasca treatment did not alter any of these parameters associated with aging. These findings indicate that chronic exposure to ayahuasca during aging did not affect memory in mice.

  15. Chronic intermittent exposure to ayahuasca during aging does not affect memory in mice.

    Science.gov (United States)

    Correa-Netto, N F; Coelho, L S; Galfano, G S; Nishide, F; Tamura, F; Shimizu, M K; Santos, J G; Linardi, A

    2017-06-05

    The Quechua term ayahuasca refers to a beverage obtained from decoctions of the liana Banisteriopsis caapi with leaves of Psychotria viridis. The ritualistic use of ayahuasca is becoming a global phenomenon, with some individuals using this beverage throughout life, including in old age. Cognitive impairment is a common manifestation during aging. There are conflicting reports on the ability of some ayahuasca compounds to exert neuroprotective or neurotoxic effects that could improve or impair learning and memory. Animal models provide a relevant and accessible means of investigating the behavioral effects of ayahuasca without the environmental conditions associated with the ritualistic use of the beverage. In this study, we investigated the influence of chronic ayahuasca exposure throughout aging on the spatial reference and habituation memories of mice. Twenty-eight male c57bl/6 mice (6 months old) received ayahuasca or water (1.5 mL/kg, orally) twice a week for 12 months and were tested in the Morris water maze (MWM), open field and elevated plus maze (EPM) tasks before and after treatment. During aging, there was significant impairment in the evocation (but not acquisition) of spatial reference memory and in habituation to the open field. There was also a decrease in locomotor activity in the open field and EPM tests, whereas the anxiety parameters were unaltered. Ayahuasca treatment did not alter any of these parameters associated with aging. These findings indicate that chronic exposure to ayahuasca during aging did not affect memory in mice.

  16. Estimating dose rates to organs as a function of age following internal exposure to radionuclides

    International Nuclear Information System (INIS)

    Leggett, R.W.; Eckerman, K.F.; Dunning, D.E. Jr.; Cristy, M.; Crawford-Brown, D.J.; Williams, L.R.

    1984-03-01

    The AGEDOS methodology allows estimates of dose rates, as a function of age, to radiosensitive organs and tissues in the human body at arbitrary times during or after internal exposure to radioactive material. Presently there are few, if any, radionuclides for which sufficient metabolic information is available to allow full use of all features of the methodology. The intention has been to construct the methodology so that optimal information can be gained from a mixture of the limited amount of age-dependent, nuclide-specific data and the generally plentiful age-dependent physiological data now available. Moreover, an effort has been made to design the methodology so that constantly accumulating metabolic information can be incorporated with minimal alterations in the AGEDOS computer code. Some preliminary analyses performed by the authors, using the AGEDOS code in conjunction with age-dependent risk factors developed from the A-bomb survivor data and other studies, has indicated that the doses and subsequent risks of eventually experiencing radiogenic cancers may vary substantially with age for some exposure scenarios and may be relatively invariant with age for other scenarios. We believe that the AGEDOS methodology provides a convenient and efficient means for performing the internal dosimetry

  17. Assessing the impacts of lifetime sun exposure on skin damage and skin aging using a non-invasive method

    Energy Technology Data Exchange (ETDEWEB)

    Kimlin, Michael G., E-mail: m.kimlin@qut.edu.au; Guo, Yuming, E-mail: guoyuming@yahoo.cn

    2012-05-15

    Background: Ultraviolet radiation exposure during an individuals' lifetime is a known risk factor for the development of skin cancer. However, less evidence is available on assessing the relationship between lifetime sun exposure and skin damage and skin aging. Objectives: This study aims to assess the relationship between lifetime sun exposure and skin damage and skin aging using a non-invasive measure of exposure. Methods: We recruited 180 participants (73 males, 107 females) aged 18-83 years. Digital imaging of skin hyperpigmentation (skin damage) and skin wrinkling (skin aging) on the facial region was measured. Lifetime sun exposure (presented as hours) was calculated from the participants' age multiplied by the estimated annual time outdoors for each year of life. We analyzed the effects of lifetime sun exposure on skin damage and skin aging. We adjust for the influence of age, sex, occupation, history of skin cancer, eye color, hair color, and skin color. Results: There were non-linear relationships between lifetime sun exposure and skin damage and skin aging. Younger participant's skin is much more sensitive to sun exposure than those who were over 50 years of age. As such, there were negative interactions between lifetime sun exposure and age. Age had linear effects on skin damage and skin aging. Conclusion: The data presented showed that self reported lifetime sun exposure was positively associated with skin damage and skin aging, in particular, the younger people. Future health promotion for sun exposure needs to pay attention to this group for skin cancer prevention messaging. - Highlights: Black-Right-Pointing-Pointer This is the first study finding the non-linear relationship between lifetime sun exposure and skin damage and skin aging. Black-Right-Pointing-Pointer This study finds there is negative interaction between lifetime sun exposure and age for skin damage and aging. Black-Right-Pointing-Pointer This study suggests that future

  18. Mechanical properties of types 304 and 316 stainless steel after long-term aging and exposure

    International Nuclear Information System (INIS)

    Horak, J.A.; Sikka, V.K.; Raske, D.T.

    1983-01-01

    Because designs for Liquid Metal Fast Breeder Reactor (LMFBR) power plants include plant lifetimes to 40 years, an understanding of the mechanical behavior of the structural alloys used is required for times of approx. 2 to 2.5 x 10 5 h. Most of the alloys used for LMFBR out-of-core structures and components are in a metastable state at the beginning of plant lifetime and evolve to a more stable state and, therefore, microstructure during plant operation. We reviewed mechanical properties and microstructures after prolonged elevated-temperature exposure of types 304 and 316 stainless steel, two alloys used extensively in fast breeder systems. Aging alters properties; in particular, it decreases toughness and tensile ductility, but the properties are still adequate for service. Because stable microstructures have been reached in long-term exposures achieved so far, properties can be expected to remain adequate for service life exposures

  19. Prenatal and childhood perfluoroalkyl substances exposures and children's reading skills at ages 5 and 8years.

    Science.gov (United States)

    Zhang, Hongmei; Yolton, Kimberly; Webster, Glenys M; Ye, Xiaoyun; Calafat, Antonia M; Dietrich, Kim N; Xu, Yingying; Xie, Changchun; Braun, Joseph M; Lanphear, Bruce P; Chen, Aimin

    2018-02-01

    Exposure to perfluoroalkyl substances (PFASs) may impact children's neurodevelopment. To examine the association of prenatal and early childhood serum PFAS concentrations with children's reading skills at ages 5 and 8years. We used data from 167 mother-child pairs recruited during pregnancy (2003-2006) in Cincinnati, OH, quantified prenatal serum PFAS concentrations at 16±3weeks of gestation and childhood sera at ages 3 and 8years. We assessed children's reading skills using Woodcock-Johnson Tests of Achievement III at age 5years and Wide Range Achievement Test-4 at age 8years. We used general linear regression to quantify the covariate-adjusted associations between natural log-transformed PFAS concentrations and reading skills, and used multiple informant model to identify the potential windows of susceptibility. Median serum PFASs concentrations were PFOS>PFOA>PFHxS>PFNA in prenatal, 3-year, and 8-year children. The covariate-adjusted general linear regression identified positive associations between serum PFOA, PFOS and PFNA concentrations and children's reading scores at ages 5 and 8years, but no association between any PFHxS concentration and reading skills. The multiple informant model showed: a) Prenatal PFOA was positively associated with higher children's scores in Reading Composite (β: 4.0, 95% CI: 0.6, 7.4 per a natural log unit increase in exposure) and Sentence Comprehension (β: 4.2, 95% CI: 0.5, 8.0) at age 8years; b) 3-year PFOA was positively associated with higher children's scores in Brief Reading (β: 7.3, 95% CI: 0.9, 13.8), Letter Word Identification (β: 6.6, 95% CI: 1.1, 12.0), and Passage Comprehension (β: 5.9, 95% CI: 1.5, 10.2) at age 5years; c) 8-year PFOA was positively associated with higher children's Word Reading scores (β: 5.8, 95% CI: 0.8, 10.7) at age 8years. Prenatal PFOS and PFNA were positively associated with children's reading abilities at age 5years, but not at age 8years; 3-year PFOS and PFNA were positively associated

  20. Exposure of patients and creation of system of quality assurance in conventional x-ray radiology in Lithuania

    International Nuclear Information System (INIS)

    Morkunas, G.; Ziliukas, J.

    1999-01-01

    One of the most important sources of exposure is medical application of ionizing radiation. X-ray examination comprise a significant part of medical exposure. Doses received by patients and quality of diagnostic images are to be optimized. Measurements of these doses were started by the Radiation Protection Centre in 1997. These measurements are performed in randomly selected x-ray departments all around Lithuania during examinations of chest and lumbar spine. Dose and parameters related to exposure and patient are registered. Quality control measurements by PMX-III are being performed on each x-ray machine used for examination. The results show that in many cases the guidance levels are of entrance surface dose for standard patient determined by the Basic Radiation Protection Standard of Lithuania are exceeded. Quality control of x-ray machines performed in 1997-1999 shows that more than 30% of these machines did not comply with the requirements though in many cases shortcomings are minor and easily removed. (au)

  1. Calculation of Buildup Factor for Gamma-ray Exposure in Two Layered Shields Made of Water and Lead

    International Nuclear Information System (INIS)

    Al-Saadi, A.H.

    2012-01-01

    The buildup factor for gamma ray exposure is most useful in calculations for biological protective shields.The buildup factors for gamma ray exposure were calculated in tow layered shields consist of water-lead and lead-water up to optical Thickness 20 mean free path (mfp) at gamma ray energies 1, 2 and 6MeV by using kalos's formula.The program has been designed to work at any atomic number of the attenuating medium, photon energy, slab thickness and and the arrangement of materials.The results obtained in this search leading to the buildup factor for gamma ray exposure at energies (1and2MeV) in lead-water were higher than the reverse case,while at energy 6 MeV the effect was opposite.The calculated data were parameterized by an empirical formula as a function of optical thickness of tow materials.The results obtained were in reasonable agreement with a previous work

  2. Exposure to violence and psychosocial adjustment among urban school-aged children.

    Science.gov (United States)

    Purugganan, Oscar H; Stein, Ruth E K; Silver, Ellen Johnson; Benenson, Blanch S

    2003-12-01

    This study determines the relationship between psychosocial adjustment in school-aged children and one aspect of exposure to violence, the proximity of exposure, in terms of (1) "physical" proximity and (2) "emotional" proximity to the victims of violence. A convenience sample of 175 children aged 9 to 12 years from a primary care clinic of a large urban hospital were interviewed about their exposure to violence using the Children's Report of Exposure to Violence. Psychosocial adjustment was measured through maternal reports using the Child Behavior Checklist (CBCL) and the Personal Adjustment and Role Skills Scale (PARS III). Children were categorized into three groups according to their closest proximity to exposure to violence ("victim" > "witness" > exposure through other people's "report") and two groups according to emotional proximity (victim was a "familiar person" or "stranger"). All children (23/175) who scored above the CBCL clinical cutoff (T score > 63) were witnesses or victims of violence. The CBCL total T scores (higher score = more maladjustment) showed that the "victims" group (mean 52.4) scored significantly higher than the "witness" group (mean 50.0) and "report" group (mean 47.4). The PARS III total scores (lower scores = more maladjustment) showed that the "victims" group (mean 87.5) scored significantly lower than the "witness" group (mean 93.1) and "report" group (mean 98.2). The relationship of the child to the victim was not associated with significantly different CBCL and PARS III scores. Children exposed to more proximal forms of violence as victims or witnesses exhibited more psychosocial maladjustment.

  3. Exposure to Famine at a Young Age and Unhealthy Lifestyle Behavior Later in Life.

    Science.gov (United States)

    Fransen, Heidi P; Peeters, Petra H M; Beulens, Joline W J; Boer, Jolanda M A; de Wit, G Ardine; Onland-Moret, N Charlotte; van der Schouw, Yvonne T; Bueno-de-Mesquita, H Bas; Hoekstra, Jeljer; Elias, Sjoerd G; May, Anne M

    2016-01-01

    A healthy diet is important for normal growth and development. Exposure to undernutrition during important developmental periods such as childhood and adolescence can have effects later in life. Inhabitants of the west of the Netherlands were exposed to severe undernutrition during the famine in the last winter of the second World War (1944-1945). We investigated if exposure of women to the Dutch famine during childhood and adolescence was associated with an unhealthy lifestyle later in life. We studied 7,525 women from the Prospect-EPIC cohort, recruited in 1993-97 and aged 0-18 years during the Dutch famine. An individual famine score was calculated based on self-reported information about experience of hunger and weight loss. We investigated the association between famine exposure in early life and four lifestyle factors in adulthood: smoking, alcohol consumption, physical activity level and a Mediterranean-style diet. Of the 7,525 included women, 46% were unexposed, 38% moderately exposed and 16% severely exposed to the Dutch famine. Moderately and severely exposed women were more often former or current smokers compared to women that did not suffer from the famine: adjusted prevalence ratio 1.10 (95% CI: 1.05; 1.14) and 1.18 (1.12; 1.25), respectively. They also smoked more pack years than unexposed women. Severely exposed women were more often physically inactive than unexposed women, adjusted prevalence ratio 1.32 (1.06; 1.64). Results did not differ between exposure age categories (0-9 and 10-17 years). We found no associations of famine exposure with alcohol consumption and no dose-dependent relations with diet. Exposure to famine early in female life may be associated with higher prevalence of smoking and physical inactivity later in life, but not with unhealthy diet and alcohol consumption.

  4. Prenatal exposure to outdoor air pollution and child behavioral problems at school age in Japan.

    Science.gov (United States)

    Yorifuji, Takashi; Kashima, Saori; Diez, Midory Higa; Kado, Yoko; Sanada, Satoshi; Doi, Hiroyuki

    2017-02-01

    Recent studies suggest positive associations between prenatal exposure to ambient air pollution and neurodevelopment of children, but evidence on the adverse effects of exposure to air pollution on child neurobehavioral development remains limited. We thus examined associations between prenatal exposure to outdoor air pollution and child behavioral problems at school age, using data from a nationwide population-based longitudinal survey in Japan, where participants were recruited in 2001 and are continuously followed. Suspended particulate matter (SPM), nitrogen dioxide, and sulfur dioxide concentrations during the 9months before birth were obtained at municipality level and assigned to those participants born in the corresponding municipality. We analyzed data from singleton births with linked pollution data available (e.g., n=33,911 for SPM). We used responses to survey questions about behavioral problems at age 8years. We conducted multilevel logistic regression analysis, adjusting for individual and municipality-level variables. Air pollution exposure during gestation was positively associated with risk for behavioral problems related to attention and delinquent or aggressive behavior. In the fully adjusted models, odds ratios following a one-interquartile-range increase in SPM were 1.06 (95% confidence interval: 1.01, 1.11) for interrupting others, 1.09 (1.03, 1.15) for failure to pay attention when crossing a street, 1.06 (1.01, 1.11) for lying, and 1.07 (1.02, 1.13) for causing public disturbance. Prenatal exposure to outdoor air pollution was associated with behavioral problems related to attention and delinquent or aggressive behavior at age 8years in a nationally representative sample in Japan. Copyright © 2016 Elsevier Ltd. All rights reserved.

  5. Psychological stress exposure to aged mice causes abnormal feeding patterns with changes in the bout number.

    Science.gov (United States)

    Yamada, Chihiro; Mogami, Sachiko; Hattori, Tomohisa

    2017-11-09

    Stress responses are affected by aging. However, studies on stress-related changes in feeding patterns with aging subject are minimal. We investigated feeding patterns induced by two psychological stress models, revealing characteristics of stress-induced feeding patterns as "meal" and "bout" (defined as the minimum feeding behavior parameters) in aged mice. Feeding behaviors of C57BL/6J mice were monitored for 24 h by an automatic monitoring device. Novelty stress reduced the meal amount over the 24 h in both young and aged mice, but as a result of a time course study it was persistent in aged mice. In addition, the decreased bout number was more pronounced in aged mice than in young mice. The 24-h meal and bout parameters did not change in either the young or aged mice following water avoidance stress (WAS). However, the meal amount and bout number increased in aged mice for 0-6 h after WAS exposure but remained unchanged in young mice. Our findings suggest that changes in bout number may lead to abnormal stress-related feeding patterns and may be one tool for evaluating eating abnormality in aged mice.

  6. Low-level lead exposure and autistic behaviors in school-age children.

    Science.gov (United States)

    Kim, Kyoung-Nam; Kwon, Ho-Jang; Hong, Yun-Chul

    2016-03-01

    The association between lead exposure and autism spectrum disorder is inconclusive. We hypothesized an association between higher blood lead concentrations and more autistic behaviors, including impaired social interactions and communication, stereotypical behaviors, and restricted interests, among school-age children. Data from 2473 Korean children aged 7-8years who had no prior history of developmental disorders were analyzed. Two follow-up surveys were conducted biennially until the children reached 11-12years of age. Blood lead concentrations were measured at every survey, and autistic behaviors were evaluated at 11-12years of age using the Autism Spectrum Screening Questionnaire (ASSQ) and Social Responsiveness Scale (SRS). The associations of blood lead concentration with ASSQ and SRS scores were analyzed using negative binomial, logistic, and linear regression models. Blood lead concentrations at 7-8years of age (geometric mean: 1.64μg/dL), but not at 9-10 and 11-12years of age, were associated with more autistic behaviors at 11-12years of age, according to the ASSQ (β=0.151; 95% confidence interval [CI]: 0.061, 0.242) and SRS (β=2.489; 95% CI: 1.378, 3.600). SRS subscale analysis also revealed associations between blood lead concentrations and social awareness, cognition, communication, motivation, and mannerisms. Even low blood lead concentrations at 7-8years of age are associated with more autistic behaviors at 11-12years of age, underscoring the need for continued efforts to reduce lead exposure. Copyright © 2016. Published by Elsevier B.V.

  7. Long-term effects of prenatal exposure to low levels of gamma rays on open-field activity in male mice

    International Nuclear Information System (INIS)

    Minamisawa, Takeru; Hirokaga, Kouichi

    1995-01-01

    The open-field activity of first-generation (F 1 ) hybrid male C57BL/6 x C3H mice irradiated with γ rays on day 14 of gestation was studied at the following ages: 6-7 months (young), 12-13 months (adult) and 19-20 months (old). Doses were 0.5 Gy or 1.0 Gy. Open-field activity was recorded with a camera. The camera output signal was recorded every second through an A/D converter to a personal computer. The field was divided into 25 8-cm 2 units. All recordings were continuous for 60 min. The walking speed of the 1.0-Gy group recorded at 19-20 months was higher than that for the comparably aged control group. The time which the irradiated group, recorded at 19-20 months, spent in the corner fields was high in comparison with the control group at the same age. Conversely, the time spent by the irradiated group in the middle fields when recorded at 19-20 months was shorter than in the comparably aged control group. No effect of radiation was shown for any of the behaviors observed and recorded at 6-7 and 12-13 months. The results demonstrate that such exposure to γ rays on day 14 of gestation results in behavioral changes which occur at 19-20 but not at 6-7 or 12-13 months. 10 refs. 2 figs., 1 tab

  8. Long-term effects of prenatal exposure to low levels of gamma rays on open-field activity in male mice.

    Science.gov (United States)

    Minamisawa, T; Hirokaga, K

    1995-11-01

    The open-field activity of first-generation (F1) hybrid male C57BL/6 x C3H mice irradiated with gamma rays on day 14 of gestation was studied at the following ages: 6-7 months (young), 12-13 months (adult) and 19-20 months (old). Doses were 0.5 Gy or 1.0 Gy. Open-field activity was recorded with a camera. The camera output signal was recorded every second through an A/D converter to a personal computer. The field was divided into 25 8-cm2 units. All recordings were continuous for 60 min. The walking speed of the 1.0-Gy group recorded at 19-20 months was higher than that for the comparably aged control group. The time which the irradiated group, recorded at 19-20 months, spent in the corner fields was high in comparison with the control group at the same age. Conversely, the time spent by the irradiated group in the middle fields when recorded at 19-20 months was shorter than in the comparably aged control group. No effect of radiation was shown for any of the behaviors observed and recorded at 6-7 and 12-13 months. The results demonstrate that such exposure to gamma rays on day 14 of gestation results in behavioral changes which occur at 19-20 months but not at 6-7 or 12-13 months.

  9. Long-term trihexyphenidyl exposure alters neuroimmune response and inflammation in aging rat: relevance to age and Alzheimer's disease.

    Science.gov (United States)

    Huang, Yuqi; Zhao, Zhe; Wei, Xiaoli; Zheng, Yong; Yu, Jianqiang; Zheng, Jianquan; Wang, Liyun

    2016-07-01

    Clinical studies have shown an association between long-term anticholinergic (AC) drug exposure and Alzheimer's disease (AD) pathogenesis, which has been primarily investigated in Parkinson's disease (PD). However, long-term AC exposure as a risk factor for developing neurodegenerative disorders and the exact mechanisms and potential for disease progression remain unclear. Here, we have addressed the issue using trihexyphenidyl (THP), a commonly used AC drug in PD patients, to determine if THP can accelerate AD-like neurodegenerative progression and study potential mechanisms involved. Male Sprague-Dawley rats (SD) were intraperitoneally injected with THP (0.3 and 1.0 mg/kg) or normal saline (NS) for 7 months. Alterations in cognitive and behavioral performance were assessed using the Morris water maze (MWM) and open field tests. After behavior tests, whole genome oligo microarrays, quantitative real-time reverse transcription-polymerase chain reaction (qRT-PCR), immunohistochemistry, and immunofluorescence-confocal were used to investigate the global mechanisms underlying THP-induced neuropathology with aging. Compared with NS controls, the MWM test results showed that THP-treated rats exhibited significantly extended mean latencies during the initial 3 months of testing; however, this behavioral deficit was restored between the fourth and sixth month of MWM testing. The same tendencies were confirmed by MWM probe and open field tests. Gene microarray analysis identified 68 (47 %) upregulated and 176 (53 %) downregulated genes in the "THP-aging" vs. "NS-aging" group. The most significant populations of genes downregulated by THP were the immune response-, antigen processing and presentation-, and major histocompatibility complex (MHC)-related genes, as validated by qRT-PCR. The decreased expression of MHC class I in THP-treated aging brains was confirmed by confocal analysis. Notably, long-term THP treatment primed hippocampal and cortical microglia to

  10. Holocene glacial history of the west Greenland Ice Sheet inferred from cosmogenic exposure ages and threshold lakes

    DEFF Research Database (Denmark)

    Larsen, Nicolaj Krog; Kjaer, K. H.; Colding, Sune Oluf

    2011-01-01

    In this study, we use a combination of 10Be exposure ages and threshold lakes to constrain the ice sheet history in Godthåbs- and Buksefjorden, west Greenland (63-64°N) during the Holocene. The 10Be cosmogenic exposure ages have been used to quantify both the ice retreat and thinning of the west...

  11. Combat exposure, social relationships, and subjective well-being among middle-aged and older Veterans.

    Science.gov (United States)

    Yang, Mai See; Burr, Jeffrey A

    2016-01-01

    This study described the association of subjective well-being with combat exposure and social relationships among middle-aged and older Veteran men in the USA. The stress-buffering hypothesis, which predicts social relationships may moderate the association between combat exposure and subjective well-being, was also examined. Data from the 2008 Health and Retirement Study (N = 2961) were used to estimate logistic regression models, focusing on three measures of subjective well-being: depression, life satisfaction, and self-reported health. In the fully adjusted models, there were no statistically significant relationships between combat exposure and the three indicators of subjective well-being. However, compared to Veterans who had lower scores on the social relationship index, Veterans who had higher scores were less likely to be depressed and less likely to report poor or fair health. Veterans who had higher scores on the social relationships index reported higher levels of life satisfaction than those Veterans who had lower scores. There was no evidence for a social relationships buffering effect. The results of this study demonstrated that combat exposure did not have a long-term relationship with subjective well-being. Longitudinal research designs with more comprehensive indicators of combat exposure may help researchers better understand some of the underlying complexity of this relationship. Complementary research with samples of women Veterans, as well as samples of Hispanic, and non-Black, non-White Veterans, is also needed.

  12. In-utero exposure to DDT and cognitive development among infants and school-aged children

    Science.gov (United States)

    Jusko, Todd A.; Klebanoff, Mark A.; Brock, John W.; Longnecker, Matthew P.

    2012-01-01

    Background Dichlorodiphenyltrichloroethane (DDT) continues to be used for control of infectious diseases in several countries. In-utero exposure to DDT and dichlorodiphenyldichloroethylene (DDE) has been associated with developmental and cognitive impairment among children. We examined this association in an historical cohort in which the level of exposure was greater than in previous studies. Methods The association of in-utero DDT and DDE exposure with infant and child neurodevelopment was examined in approximately 1100 subjects in the Collaborative Perinatal Project, a prospective birth cohort enrolling pregnant women from 12 study centers in the U.S. from 1959 to 1965. Maternal DDT and DDE concentrations were measured in archived serum specimens. Infant mental and motor development was assessed at age 8 months using the Bayley Scales of Infant Development, and child cognitive development was assessed at age 7 years using the Wechsler Intelligence Scale for Children. Results Although levels of both DDT and DDE were relatively high in this population (median DDT concentration, 8.9 µg/L; DDE, 24.5 µg/L), neither was related to Mental or Psychomotor Development scores on the Bayley Scales or to Full-Scale IQ at 7 years of age. Categorical analyses showed no evidence of dose-response for either maternal DDT or DDE, and estimates of the association between continuous measures of exposure and neurodevelopment were indistinguishable from 0. Conclusions Adverse associations were not observed between maternal serum DDT and DDE concentrations and offspring neurodevelopment at 8 months or 7 years of age in this cohort. PMID:22766752

  13. Learning Disabilities and Intellectual Functioning in School-Aged Children With Prenatal Cocaine Exposure

    OpenAIRE

    Morrow, Connie E.; Culbertson, Jan L.; Accornero, Veronica H.; Xue, Lihua; Anthony, James C.; Bandstra, Emmalee S.

    2006-01-01

    Risk for developing a learning disability (LD) or impaired intellectual functioning by age 7 was assessed in full-term children with prenatal cocaine exposure drawn from a cohort of 476 children born full term and enrolled prospectively at birth. Intellectual functioning was assessed using the Wechsler Intelligence Scale for Children–Third Edition (Wechsler,1991) shortform, and academic functioning was assessed using the Wechsler Individual Achievement Test (WIAT; Wechsler,1993) Screener by e...

  14. Practical protective tools for occupational exposure: 1) double focus spectacles for the aged with highly refracted glass lens 2) remodeled barrier for radiation protection.

    Science.gov (United States)

    Kurokawa, S; Yabe, S; Takamura, A; Ishizaki, H; Aizawa, S

    2000-11-30

    Two practical protective tools for occupational exposure for neurointerventional radiologists are presented. The first purpose of this study was to investigate the effectiveness of double focus spectacles for the aged with a highly refracted glass lens (special spectacles for the aged) for radiation protection of the crystalline lens of the eye in comparison with other spectacles on the market, based on the measurement of film density which was obtained by exposure of X-ray through those spectacles. As a result of the film densitometry mentioned above, the effectiveness of special spectacles for the aged in radiation protection was nearly equal to the effectiveness of a goggle type shield which is made with a 0.07 mm lead-equivalent plastic lens. The second purpose of this study was to investigate the effectiveness of the protective barrier, which we remodeled for cerebral angiography or neuroendovascular therapy, for radiation exposure, based on the measurement in a simulated study with a head phantom, and on the measurement of radiation exposure in operaters during procedures of clinical cases. In the experimental study radiation exposure in supposed position of the crystalline lens was reduced to about one third and radiation exposure in supposed position of the gonadal glands was reduced to about one seventh, compared to radiation exposure without employing the barrier. The radiation exposure was monitored at the left breast of three radiologists, in 215 cases of cerebral angiography. Employing the barrier in cerebral angiography, average equivalent dose at the left breast measured 1.49mu Sv during 10 min of fluoroscopy. In three kinds of neuroendovascular therapy in 40 cases, radiation exposure in an operator was monitored in the same fashion and the dose was recorded less than the result reported in previous papers in which any protective barrier have not been employed in the procedure (1,2). As a result, the two above mentioned protective tools are

  15. Age differences in how consumers behave following exposure to DTC advertising.

    Science.gov (United States)

    DeLorme, Denise E; Huh, Jisu; Reid, Leonard N

    2006-01-01

    This study was conducted to provide additional evidence on how consumers behave following direct-to-consumer (DTC) advertising exposure and to determine if there are differences in ad-prompted acts (drug inquiry and drug requests) between different age groups (i.e., older, mature, and younger adults). The results suggest that younger, mature, and older consumers are all moved to act by DTC drug ads, but that each age group behaves in different ways. Somewhat surprisingly, age was not predictive of ad-prompted behavior. DTC advertising was no more effective at moving older consumers to behave than their younger counterparts. These results suggest that age does not matter that much when it comes to the "moving power" of prescription drug advertising, even though research indicates that older consumers are more vulnerable to the persuasive effects of communication.

  16. Age-related hearing decline in individuals with and without occupational noise exposure

    Directory of Open Access Journals (Sweden)

    Christina Hederstierna

    2016-01-01

    Full Text Available This study was conducted to compare the pattern of age-related hearing decline in individuals with and without self-reported previous occupational noise exposure. This was a prospective, population-based, longitudinal study of individuals aged 70-75 years, from an epidemiological investigation, comprising three age cohorts. In total there were 1013 subjects (432 men and 581 women. Participants were tested with pure tone audiometry, and they answered a questionnaire to provide information regarding number of years of occupational noise exposure. There were no significant differences in hearing decline, at any frequency, for those aged 70-75 years between the noise-exposed (N= 62 men, 22 women and the nonexposed groups (N = 96 men, 158 women. This study supports the additive model of noise-induced hearing loss (NIHL and age-related hearing loss (ARHL. The concept of different patterns of hearing decline between persons exposed and not exposed to noise could not be verified.

  17. Long-Term Flexural Behaviors of GFRP Reinforced Concrete Beams Exposed to Accelerated Aging Exposure Conditions

    Directory of Open Access Journals (Sweden)

    Yeonho Park

    2014-06-01

    Full Text Available This study investigates the impact of accelerated aging conditions on the long-term flexural behavior and ductility of reinforced concrete (RC members with glass fiber-reinforced polymer (GFRP bars (RC-GFRP specimen and steel bars (RC-steel specimen. A total of thirty six specimens were designed with different amounts of reinforcement with three types of reinforcing bars (i.e., helically wrapped GFRP, sand-coated surface GFRP and steel. Eighteen specimens were subjected to sustained loads and accelerated aging conditions (i.e., 47 °C and 80% relative humidity in a chamber. The flexural behavior of specimens under 300-day exposure was compared to that of the companion specimens without experiencing accelerated aging conditions. Results indicate that the accelerated aging conditions reduced flexural capacity in not only RC-steel, but also RC-GFRP specimens, with different rates of reduction. Different types of GFRP reinforcement exhibited different rates of degradation of the flexural capacity when embedded in concrete under the same exposure conditions. Several existing models were compared with experimental results for predicting the deflection and deformability index for specimens. Bischoff and Gross’s model exhibited an excellent prediction of the time-dependent deflections. Except for the deformability index proposed by Jaeger, there was no general trend related to the aging duration. This study recommends the need for further investigation on the prediction of the deformability index.

  18. Tumours associated with medical X-ray therapy exposure in childhood

    International Nuclear Information System (INIS)

    Colman, M.; Kirsch, M.; Creditor, M.

    1978-01-01

    A total of 5166 persons who were exposed to limited field (80-100 cm 2 ) X-ray irradiation to the head, neck and upper chest region during childhood and adolescence have provided an outstanding opportunity for the study of tumour incidence following medical X-ray therapy. More than 3254 subjects have been traced, 3108 have completed questionnaires eliciting information on tumour incidence, and 1539 of these were subjected to a thorough clinical screening procedure that included a thyroid scintigram. The prevalence of thyroid tumours in the 1539 clinically screened subjects and the prevalence of all other tumours in the 3254 subjects traced can therefore be assumed to reflect the risks in the group of irradiated subjects as a whole. Median age at irradiation was 3.5 years, and median radiation dose 790 rads (7.9 Gy). Thyroid tumour was diagnosed in 413 subjects. Of those undergoing surgery (273) 30.3% were found to have thyroid cancer. A total of 366 surgical pathology specimens of the thyroid, including 93 from subjects who were diagnosed at other hospitals, were examined revealing 73 papillary carcinomas, 12 follicular carcinomas and 26 microscopic papillary carcinomas. One hundred and eighty-seven other (non-thyroid) neoplasmas identified included 27 benign and 10 malignant salivary gland tumours, 16 benign and seven malignant tumours of neural origin (brain, spinal cord, cranial and peripheral nerves), 37 skin tumours, 9 lymphomas, 8 gonadal tumours, 45 breast tumours and 28 tumours of miscellaneous sites. The incidence of thyroid tumours, salivary gland tumours and primary brain tumours was considerably in excess of the expected incidence (p values<0.0001), and a radiation dose-effect correlation was observed for thyroid and brain tumours. Gonadal tumours and lymphomas did not occur in excess of the expected incidence

  19. Radiological protection in X-ray diagnosis: How to minimize the patient exposure in X-ray diagnosis

    International Nuclear Information System (INIS)

    Araujo, A.M.C. de.

    1986-01-01

    The principles involved in the radiation protection and the radiographic process are discussed. An adequate systematic work is presented, to achieve the main goal of the Radiation Protection that is, to irradiate the patient and the staff with lowest possible exposure. (M.A.C.) [pt

  20. X-ray exposure dose for the gonadal gland by the examination of computerized tomography and its protection

    International Nuclear Information System (INIS)

    Moriuchi, Iwao; Kaiya, Hisanori; Hirata, Toshifumi; Asada, Shuichi

    1978-01-01

    Computerized tomography (CT) is very useful for neuroradiological examination, and so it may possibly be used for screening tests. But x-ray exposure dose by a examination of CT is considerable, especially for the male gonadal gland. This study showed that the dose from a complete CT examination of 10 - 15 scans for a male gonadal gland was about 1,800 times more than a single plain neuroradiography. But by only a 0.07 mm lead equivalent protecter, the exposure dose resulting from CT for a gonadal gland could be reduced to 0.0 mrad. (auth.)

  1. Exposure to 16O-particle radiation causes aging-like decrements in rats through increased oxidative stress, inflammation and loss of autophagy.

    Science.gov (United States)

    Poulose, Shibu M; Bielinski, Donna F; Carrihill-Knoll, Kirsty; Rabin, Bernard M; Shukitt-Hale, Barbara

    2011-12-01

    Exposing young rats to particles of high energy and charge (HZE particles), a ground-based model for exposure to cosmic rays, enhances indices of oxidative stress and inflammation, disrupts the functioning of neuronal communication, and alters cognitive behaviors. Even though exposure to HZE particles occurs at low fluence rates, the cumulative effects of long-term exposure result in molecular changes similar to those seen in aged animals. In the present study, we assessed markers of autophagy, a dynamic process for intracellular degradation and recycling of toxic proteins and organelles, as well as stress and inflammatory responses, in the brains of Sprague-Dawley rats irradiated at 2 months of age with 5 and 50 cGy and 1 Gy of ionizing oxygen particles ((16)O) (1000 MeV/n). Compared to nonirradiated controls, exposure to (16)O particles significantly inhibited autophagy function in the hippocampus as measured by accumulation of ubiquitin inclusion bodies such as P62/SQSTM1, autophagosome marker microtubule-associated protein 1 beta light chain 3 (MAP1B-LC3), beclin1 and proteins such as mammalian target of rapamycin (mTOR). The molecular changes measured at short (36 h) and long (75 days) intervals after (16)O-particle exposure indicate that the loss of autophagy function occurred shortly after exposure but was recovered via inhibition of mTOR. However, HZE-particle radiation caused significant sustained loss of protein kinase C alpha (PKC-α), a key G protein modulator involved in neuronal survival and functions of neuronal trophic factors. Exposure to (16)O particles also caused substantial increases in the levels of nuclear factor kappa B (NF-κB) and glial fibrillary acidic protein (GFAP), indicating glial cell activation 75 days after exposure. This is the first report to show the molecular effects of (16)O-particle radiation on oxidative stress, inflammation and loss of autophagy in the brain of young rats.

  2. Measurement of exposure buildup factors: The influence of scattered photons on gamma-ray attenuation coefficients

    Science.gov (United States)

    Mann, Kulwinder Singh

    2018-01-01

    Scattered photon's influence on measured values of attenuation coefficients (μm, cm2g-1) for six low-Z (effective atomic number) building materials, at three photon energies has been estimated. Narrow-beam transmission geometry has been used for the measurements. Samples of commonly used engineering materials (Cements, Clay, Lime-Stone, Plaster of Paris) have been selected for the present study. Standard radioactive sources Cs137 and Co60 have been used for obtaining γ-ray energies 661.66, 1173.24 and 1332.50 keV. The optical thickness (OT) of 0.5 mfp (mean free path) has been found the optimum optical thickness (OOT) for μm-measurement in the selected energy range (661.66-1332.50 keV). The aim of this investigation is to provide neglected information regarding subsistence of scattered photons in narrow beam geometry measurements for low-Z materials. The measurements have been performed for a wide range of sample-thickness (2-26 cm) such that their OT varies between 0.2-3.5 mfp in selected energy range. A computer program (GRIC2-toolkit) has been used for various theoretical computations required in this investigation. It has been concluded that in selected energy-range, good accuracy in μm-measurement of low-Z materials can be achieved by keeping their sample's OT below 0.5 mfp. The exposure buildup factors have been measured with the help of mathematical-model developed in this investigation.

  3. Risk of mammary oncogenesis from exposure to neutrons or gamma rays: experimental methodology and early findings

    International Nuclear Information System (INIS)

    Clifton, K.H.; Sridharan, B.N.; Gould, M.N.

    1976-01-01

    A project has been initiated to define the risk of oncogenesis per rad of high or low linear energy transfer (LET) radiation per surviving mammary cell and its modification by hormones. This work was undertaken because: (a) mammary carcinoma is the principle neoplastic disease of American women; (b) rats have been demonstrated to be remarkably susceptible to mammary oncogenesis following neutron irradiation; (c) rats are similar to women in the importance of hormones to carcinoma induction and progression in their mammary glands; and (d) exposure to neutrons is likely to increase with increasing use of nuclear reactors and development of neutron radiotherapy sources. To measure mammary cell survival and, ultimately, postirradiation repair capacity, the authors are developing an in-vivo end-point dilution assay based on the formation of glandular structures after the transplantation of known numbers of monodispersed rat mammary epithelial cell suspensions. Such grafts initially give rise to alveolus-like spheres and, with time, to complete glands. Growth and secretion can be stimulated in them by hormonal manipulation. In the short-term assays and the longer-term carcinogenesis studies, elevated endogenous mammotropic hormone, prolactin (MtH) levels have been induced by grafting of anterior pituitary tissue or of MtT (MtH-secreting pituitary tumours). Steroid hormone levels have been manipulated by surgical ablation or injection. Irradiations have been performed with a modified neutron fission spectrum generated by a Triga reactor, or with 137 Cs γ rays. Results with two inbred rat strains indicate: (a) that the type (carcinoma or fibroadenoma), incidence and latency of mammary tumours is markedly influenced by the circulating levels of MtH: and (b) that adrenal deficiency markedly enhances the induction of mammary carcinomas in irradiated rats with high endogenous MtH levels. Further studies are in progress. (author)

  4. MODERN PECULIARITIES OF THE MEDICAL EXPOSURE LEVELS FORMING OF THE TATARSTAN REPUBLIC POPULATION DURING X-RAY PROCEDURES IMPLEMENTATION

    Directory of Open Access Journals (Sweden)

    S. A. Ryzhkin

    2015-01-01

    Full Text Available The purpose. The purpose of the investigation is an assessment of the peculiarities of forming and registration of the collective doses of patients and the population of the Tatarsatan Republic (RT from medical exposure and the development of measures for optimization of this radiation factor.Materials and methods. The analysis is based on the forms of the Federal statistical observation № 3-DOZ «Data on the exposure doses to patients obtained during medical radiological examination» (form № 3-DOZ and radiation-hygienic passports of RT for the period from 2006 to 2013.The results. Annually in RT there is an increase of the number of performed X-ray procedures, which reached the value of 6279696 (1.64 procedures per resident per year in 2013. During the reporting period (from 2006 to 2013 the structure of the performed X-ray procedures has also changed. It is observed that the percentage of fluorography procedures in the overall structure decreased from 41.3% to 31.3% at the same time the level of absolute value of annually performed fluorography procedures is stable. There is an increase in the absolute number of radiographic procedures performed during the period from 2578754 to 4072810 X-rays per year, that is 1.58 times higher. Absolute and relative values related to X-ray fluoroscopy examinations decreased from 1.1% to 0.7%. In contrast, the absolute number of annually performed X-ray computed tomography examinations (CT has increased over the period by 3.3 times and percentage of CT in overall structure of X-ray procedure is 2.7%. The number of special investigations has increased in 2.1 times, but the relative value remained at average level of 0.4% on general background of the increasing of X-ray activity in the region. This fact influenced the change in the radiation-hygienic indexes of medical radiation exposure of the population of RT. According to №3-DOZ forms and radiation-hygienic passports of the

  5. Evaluation of patient exposure with Flat Panel Detector (FPD) in X-ray TV system

    International Nuclear Information System (INIS)

    Yamada, M.; Komiya, N.; Kawaguchi, A.; Suzuki, M.; Suzuki, Shoichi; Asada, Yasuki

    2008-01-01

    The use of flat-panel detector (FPD) systems in TV equipment for gastrointestinal tract examination is increasing. The use of FPD systems is believed to reduce the exposure dose. When our institution changed its TV equipment from an image intensifier (GE; MS90Tj) system to an FPD (Shimadzu; SONIALVISION safire DAR-3500) system, we measured the doses produced and carried out a comparative examination of the extent to which exposure could be reduced. Two TV systems were used. We used an analyzer to measure output waveform, tube voltage, and half-value layer (HVL), and an ionization chamber dosimeter to carry out dose-in-air measurements. Body thickness, number of image acquisitions, and fluoroscopy time are required for the calculation of entrance skin dose (ESD). We therefore measured body thicknesses in 1000 upper gastrointestinal tract (UGI) and barium enemas and obtained average body thicknesses for males and females by age group. Values used for number of image acquisitions and fluoroscopy times were the averages in our institution over a two-year period. When an I.I. system was used, the average ESD during UGI examination were 126.8 mGy fluoroscopy dose and 11.62 mGy imaging dose, for an average total dose of 138.42 mGy per examination. ESD during barium enema averaged 201.73 mGy fluoroscopy dose and 45.2 mGy imaging dose, for an average total dose of 246.92 mGy per examination. When an FPD system was used, the average ESD during UGI examination were 58.71 mGy fluoroscopy dose and 5.72 mGy imaging dose, for an average total dose of 64.43 mGy per examination. ESD during barium enema averaged 112.21 mGy fluoroscopy dose and 24.55 mGy imaging dose, for an average total dose of 136.76 mGy per examination. The use of an FPD system reduced both fluoroscopy dose and imaging dose by 50%. The number of TV systems equipped with FPD in Japan has increased from around 1300 in 2006 to around 1700 in 2007. The use of FPD systems can be expected to increase in future. This

  6. Learning disabilities and intellectual functioning in school-aged children with prenatal cocaine exposure.

    Science.gov (United States)

    Morrow, Connie E; Culbertson, Jan L; Accornero, Veronica H; Xue, Lihua; Anthony, James C; Bandstra, Emmalee S

    2006-01-01

    Risk for developing a learning disability (LD) or impaired intellectual functioning by age 7 was assessed in full-term children with prenatal cocaine exposure drawn from a cohort of 476 children born full term and enrolled prospectively at birth. Intellectual functioning was assessed using the Wechsler Intelligence Scale for Children-Third Edition (Wechsler, 1991) short form, and academic functioning was assessed using the Wechsler Individual Achievement Test (WIAT; Wechsler, 1993) Screener by examiners blind to exposure status. LDs were categorized based on ability-achievement discrepancy scores, using the regression-based predicted achievement method described in the WIAT manual. The sample in this report included 409 children (212 cocaine-exposed, 197 non-cocaine-exposed) from the birth cohort with available data. Cumulative incidence proportions and relative risk values were estimated using STATA software (Statacorp, 2003). No differences were found in the estimate of relative risk for impaired intellectual functioning (IQ below 70) between children with and without prenatal cocaine exposure (estimated relative risk = .95; 95% confidence interval [CI] = 0.65, 1.39; p = .79). The cocaine-exposed children had 2.8 times greater risk of developing a LD by age 7 than non-cocaine-exposed children (95% CI = 1.05, 7.67; p = .038; IQ >/= 70 cutoff). Results remained stable with adjustment for multiple child and caregiver covariates, suggesting that children with prenatal cocaine exposure are at increased risk for developing a learning disability by age 7 when compared to their non-cocaine-exposed peers.

  7. Acetaminophen hepatotoxicity in mice: Effect of age, frailty and exposure type

    Science.gov (United States)

    Kane, Alice E.; Mitchell, Sarah J.; Mach, John; Huizer-Pajkos, Aniko; McKenzie, Catriona; Jones, Brett; Cogger, Victoria; Le Couteur, David G.; de Cabo, Rafael; Hilmer, Sarah N.

    2018-01-01

    Acetaminophen is a commonly used analgesic that can cause severe hepatotoxicity in overdose. Despite old age and frailty being associated with extensive and long-term utilization of acetaminophen and a high prevalence of adverse drug reactions, there is limited information on the risks of toxicity from acetaminophen in old age and frailty. This study aimed to assess changes in the risk and mechanisms of hepatotoxicity from acute, chronic and sub-acute acetaminophen exposure with old age and frailty in mice. Young and old male C57BL/6 mice were exposed to either acute (300 mg/kg via oral gavage), chronic (100 mg/kg/day in diet for six weeks) or sub-acute (250 mg/kg, t.i.d., for three days) acetaminophen, or saline control. Pre-dosing mice were scored for the mouse clinical frailty index, and after dosing serum and liver tissue were collected for assessment of toxicity and mechanisms. There were no differences with old age or frailty in the degree of hepatotoxicity induced by acute, chronic or subacute acetaminophen exposure as assessed by serum liver enzymes and histology. Age-related changes in the acetaminophen toxicity pathways included increased liver GSH concentrations, increased NQO1 activity and an increased pro- and anti-inflammatory response to acetaminophen in old age. Frailty-related changes included a negative correlation between frailty index and serum protein, albumin and ALP concentrations for some mouse groups. In conclusion, although there were changes in some pathways that would be expected to influence susceptibility to acetaminophen toxicity, there was no overall increase in acetaminophen hepatotoxicity with old age or frailty in mice. PMID:26615879

  8. Comparative response of dogs and monkeys to sublethal acute and continuous low dose-rate gamma-ray exposure

    International Nuclear Information System (INIS)

    Spalding, J.F.; Holland, L.M.; Johnson, O.S.; LaBauve, P.M.; London, J.E.; Prine, J.R.; Vigil, E.A.

    1977-02-01

    Monkeys (Macaca mulatta) and dogs (beagle) were given thirteen 100-rad gamma-ray doses at 28-day intervals. The comparative response (injury and recovery) of the hematopoietic system of the two species was observed at 7-day intervals during the exposure regime. At 84 days after the thirteenth gamma-ray dose, the 1300-rad conditioned and control dogs and monkeys were challenged continuously with 35 R/day until death to determine the amount of radiation-induced injury remaining in conditioned animals as a reduction in mean survival time. Dogs (50 percent) and monkeys (8 percent) died from injury incurred during the conditioning exposures. Thus, the comparative response of dogs and monkeys to dose protraction by acute dose fractionation was similar to what might be expected from a single acute dose. Mean survival times for nonconditioned dogs and monkeys during continuous exposure at 35 R/day were the same (approximately 1400 h). Thus, hematopoietic response of the two species by this method of dose protraction was not significantly different. Mean survival times of conditioned dogs and monkeys during the continuous 35 R/day gamma-ray challenge exposure were greater than for their control counterparts. Thus, the long-term radiation-induced injury was not measurable by this method. Conditioning doses of more than four times the acute LD 50 - 30 in dogs and approximately two times that of monkeys served only to increase both mean survival time and variance in a gamma-ray stress environment with a dose rate of 35 R/day

  9. X-ray exposures given with various combinations of film and screen

    International Nuclear Information System (INIS)

    Schlenker, R.A.; Kirsh, I.E.

    A comparison of entrance exposure doses of patients for various film and screen combinations and xeroradiographs showed that moderate speed screen and film gave exposures 4 to 7 times greater than fast film and screen and that xeroradiographs produced exposures 20 to 40 times greater than fast film and screen. Xeroradiographs produced table top incident exposures which exceeded Illinois Department of Health limits, while conventional film-screen combinations did not. (U.S.)

  10. Nitrosatable Drug Exposure during Pregnancy and Preterm and Small-for-Gestational-Age Births.

    Science.gov (United States)

    Vuong, Ann M; Shinde, Mayura U; Brender, Jean D; Shipp, Eva M; Huber, John C; Zheng, Qi; McDonald, Thomas J; Sharkey, Joseph R; Hoyt, Adrienne T; Werler, Martha M; Kelley, Katherine E; Langlois, Peter H; Canfield, Mark A

    2015-01-01

    Nitrosatable drugs react with nitrite in the stomach to form N-nitroso compounds, observed in animal models to result in adverse pregnancy outcomes, such as birth defects and reduced fetal weight. Previous studies examining prenatal exposure to medications classified as nitrosatable have reported an increased risk of preterm births (PTBs) and small-for-gestational-age (SGA) infants. Using data from mothers (controls) of babies without major birth defects from the National Birth Defects Prevention Study, prenatal nitrosatable drug usage by trimester and month of gestation was examined in relation to PTBs and SGA infants. Positive associations were observed with nitrosatable drug use and PTBs, with the strongest relationship with second trimester exposure (adjusted hazard ratio [aHR] 1.37, [95% confidence interval (CI) 1.10, 1.70]). Of the nitrosatable functional groups, secondary amines were the most notable, with a higher association among women with second (aHR 1.37, [95% CI 1.05, 1.79]) and third (aHR 1.34, [95% CI 1.02, 1.76]) trimester exposure compared with women with no prenatal nitrosatable drug use. Among SGA infants, a borderline association was noted with amide exposure during the third trimester (adjusted odds ratio 1.43 [95% confidence interval [CI] 1.00, 2.05]). Prenatal exposure to nitrosatable drugs during the second and third trimester of pregnancy, particularly secondary amines, might increase the risk of PTBs. However, prenatal exposure to nitrosatable drugs was not associated with SGA infants, with the exception of amide drugs. © 2014 John Wiley & Sons Ltd.

  11. Effects of prenatal cocaine exposure on special education in school-aged children.

    Science.gov (United States)

    Levine, Todd P; Liu, Jing; Das, Abhik; Lester, Barry; Lagasse, Linda; Shankaran, Seetha; Bada, Henrietta S; Bauer, Charles R; Higgins, Rosemary

    2008-07-01

    The objective of this study was to evaluate the effects of prenatal cocaine exposure on special education at age 7 with adjustment for covariates. As part of the prospective, longitudinal, multisite study of children with prenatal cocaine exposure (Maternal Lifestyle Study), school records were reviewed for 943 children at 7 years to determine involvement in special education outcomes: (1) individualized education plan; (2) special education conditions; (3) support services; (4) special education classes; and (5) speech and language services. Logistic regression was used to examine the effect of prenatal cocaine exposure on these outcomes with environmental, maternal, and infant medical variables as covariates, as well as with and without low child IQ. Complete data for each analysis model were available for 737 to 916 children. When controlling for covariates including low child IQ, prenatal cocaine exposure had a significant effect on individualized education plan. When low child IQ was not included in the model, prenatal cocaine exposure had a significant effect on support services. Male gender, low birth weight, white race, and low child IQ also predicted individualized education plan. Low birth weight and low child IQ were significant in all models. White race was also significant in speech and language services. Other covariate effects were model specific. When included in the models, low child IQ accounted for more of the variance and changed the significance of other covariates. Prenatal cocaine exposure increased the likelihood of receiving an individualized education plan and support services, with adjustment for covariates. Low birth weight and low child IQ increased the likelihood of all outcomes. The finding that white children were more likely to get an individualized education plan and speech and language services could indicate a greater advantage in getting educational resources for this population.

  12. A real-time regional adaptive exposure method for saving dose-area product in x-ray fluoroscopy

    International Nuclear Information System (INIS)

    Burion, Steve; Funk, Tobias; Speidel, Michael A.

    2013-01-01

    Purpose: Reduction of radiation dose in x-ray imaging has been recognized as a high priority in the medical community. Here the authors show that a regional adaptive exposure method can reduce dose-area product (DAP) in x-ray fluoroscopy. The authors' method is particularly geared toward providing dose savings for the pediatric population. Methods: The scanning beam digital x-ray system uses a large-area x-ray source with 8000 focal spots in combination with a small photon-counting detector. An imaging frame is obtained by acquiring and reconstructing up to 8000 detector images, each viewing only a small portion of the patient. Regional adaptive exposure was implemented by varying the exposure of the detector images depending on the local opacity of the object. A family of phantoms ranging in size from infant to obese adult was imaged in anteroposterior view with and without adaptive exposure. The DAP delivered to each phantom was measured in each case, and noise performance was compared by generating noise arrays to represent regional noise in the images. These noise arrays were generated by dividing the image into regions of about 6 mm 2 , calculating the relative noise in each region, and placing the relative noise value of each region in a one-dimensional array (noise array) sorted from highest to lowest. Dose-area product savings were calculated as the difference between the ratio of DAP with adaptive exposure to DAP without adaptive exposure. The authors modified this value by a correction factor that matches the noise arrays where relative noise is the highest to report a final dose-area product savings. Results: The average dose-area product saving across the phantom family was (42 ± 8)% with the highest dose-area product saving in the child-sized phantom (50%) and the lowest in the phantom mimicking an obese adult (23%). Conclusions: Phantom measurements indicate that a regional adaptive exposure method can produce large DAP savings without compromising

  13. Effects of fetal exposure to gamma rays on aggressive behavior in adult male mice

    International Nuclear Information System (INIS)

    Minamisawa, Takeru; Hirokaga, Kouichi; Sasaki, Shunsaku; Noda, Yutaka.

    1992-01-01

    Aggressive behavior (AB) in first generation (F 1 ) hybrid male C57BL/6 x C3H mice irradiated on the 14th day of gestation was studied at 100-135 days of age. Gravid female mice were irradiated with 1.0 or 2.0 Gy of gamma rays to the whole body. The AB of pairs of mice were recorded with a capacitance-induction motility monitor and on videotape. Recordings were continued for 90 min, starting at 2:00 PM. Vigorous wrestling, boxing and biting were regarded as AB. Data recorded at 15-min intervals were stored on micro-computer discs. The body weight for the irradiated group was significantly lower than that for the control group. The number of instances of AB was significantly higher in the irradiated group. The AB of the 2.0 Gy group was significantly more intensive than that of the control group. No difference in the duration of AB was found for the 2 irradiated and the control groups. Results demonstrate that male mice irradiated prenatally show increased aggressiveness. (author)

  14. Development of a concept for radiation patients exposure assessment during dental X-ray examinations and statistical data acquisition for the determination of a diagnostic reference value

    International Nuclear Information System (INIS)

    Kueppers, C.; Sering, M.; Poppe, B.; Poplawski, A.; Looe, H.K.; Beyer, D.; Pfaffenberger, A.; Chofor, N.; Eenboom, F.

    2012-01-01

    The research project on the development a concept for radiation patients exposure assessment during dental X-ray examinations and statistical data acquisition for the determination of a diagnostic reference value includes the following issues: Fundamental facts: dental X-ray examination techniques, dose relevant factors and characteristics during X-ray examinations, radiation exposed organs during dental X-ray examinations, dose assessment based on phantoms. Materials and methodologies of the project: TLD measurements using the phantom, calculation of the effective dose during dental X-ray examinations, properties and settings of the reference facilities for the determination of radiation exposure, selection of dental offices, dosimetric measurements, data acquisition and statistical evaluation. Results of dosimetric examinations: results of dosimetric measurements at reference facilities, results of dosimetric measurements in dental offices. Discussion of the concept for the determination of the radiation exposure during dental X-ray examinations.

  15. Determination of energy absorbed during X-ray exposure of the forearm by means of thermoluminescent dosimetry

    International Nuclear Information System (INIS)

    Hofmann, E.

    1982-01-01

    LiF dose meters were used to determine radiation doses in conventional X-ray diagnostic pictures of the forearm. The paper describes a method for determining integral doses by using these dose meters. It describes in detail how a phantom forearm apt for the purpose is to be made. In the Federal Republic of Germany, malignant growth incidence due to X-ray pictures of the forearm is enhanced by about .01 cases each year. The malignant growth incidence rate caused by X-ray diagnostic measures is low. It is therefore generally justified to neglect limbs in exemplary studies of radiation exposure. All calculations and considerations took into account that all possible radiation protection measures have been duly applied. (orig./DG) [de

  16. Solar proton exposure of an ICRU sphere within a complex structure part II: Ray-trace geometry.

    Science.gov (United States)

    Slaba, Tony C; Wilson, John W; Badavi, Francis F; Reddell, Brandon D; Bahadori, Amir A

    2016-06-01

    A computationally efficient 3DHZETRN code with enhanced neutron and light ion (Z ≤ 2) propagation was recently developed for complex, inhomogeneous shield geometry described by combinatorial objects. Comparisons were made between 3DHZETRN results and Monte Carlo (MC) simulations at locations within the combinatorial geometry, and it was shown that 3DHZETRN agrees with the MC codes to the extent they agree with each other. In the present report, the 3DHZETRN code is extended to enable analysis in ray-trace geometry. This latest extension enables the code to be used within current engineering design practices utilizing fully detailed vehicle and habitat geometries. Through convergence testing, it is shown that fidelity in an actual shield geometry can be maintained in the discrete ray-trace description by systematically increasing the number of discrete rays used. It is also shown that this fidelity is carried into transport procedures and resulting exposure quantities without sacrificing computational efficiency. Published by Elsevier Ltd.

  17. Relationship between X-ray exposure and malignant transformation in C3H 10T1/2 cells

    International Nuclear Information System (INIS)

    Kennedy, A.R.; Fox, M.; Murphy, G.; Little, J.B.

    1980-01-01

    The appearance of transformed foci after x-irradiation of the C3H 10T1/2 line of murine cells requires extensive proliferation followed by prolonged incubation under conditions of confluence. When the progeny of irradiated cells are resuspended and plated to determine the number of potential transformed foci, the absolute yield is constant over a wide range of dilutions and is similar to that observed in cultures that have not been resuspended. In addition, for cells exposed to a given x-ray dose, the number of transformed foci per dish is independent of the number of irradiated cells. These observations suggest that few, if any, of the transformed clones occur as a direct consequence of the x-ray exposure and challenge the hypothesis that transformed foci are the clonal products of occasional cells that have experienced an x-ray-induced mutational change. Rather, it appears that at least two steps are involved. We suggest that exposure to x-rays results in a change, for example, the induction or expression of some cell function, in many or all of the cells and that this change is transmitted to the progeny of the surviving cells; a consequence of this change is an enhanced probability of the occurrence of a second step, transformation, when these cells are maintained under conditions of confluence

  18. Age as a factor in assessing risks to patients from the use of x-rays

    International Nuclear Information System (INIS)

    Le Heron, J.

    1996-01-01

    Effective dose is currently widely used as a means of quantifying patient dose (and hence patient risk) in diagnostic radiology. Its appeal stems primarily from being able to normalise partial body irradiations into equivalent whole body irradiations, and additionally from being linked to a sound definition of radiation detriment. However there are several aspects of effective dose that should lead to its use being accompnied by a degree of caution. One such factor is age. Calculation of age specific tissue weighting factors for the tissues used in the formulation of effective dose show that the relative contributions of the tissues vary considerably as a function of age. When this is combined with age specific risk factors for cancers and hereditary effects, the implications of a given 'effective dose' for an x-ray procedure depend markedly on the age of the patient. Because of the elderly component of the patient population, the ensuing risks arising from diagnostic radiology are at a level considerably less than that assessed using the population-averaged approach. (author)

  19. Exposure to phthalates in house dust and associated allergies in children aged 6-12years.

    Science.gov (United States)

    Ait Bamai, Yu; Araki, Atsuko; Kawai, Toshio; Tsuboi, Tazuru; Saito, Ikue; Yoshioka, Eiji; Cong, Shi; Kishi, Reiko

    2016-11-01

    Phthalates are widely used as plasticizers in household products. Several studies have reported an association between phthalate exposure and an increased risk of allergies. The present study estimated phthalate exposure in children aged 6-12years and assessed potential correlations with allergies. House dust samples were collected from floors and multi-surface objects >35cm above the floor. Urine samples were collected from the first morning void of the day. Daily phthalate intake (DI dust and DI) was estimated using both house dust and urinary metabolite concentrations. Exposure to di-2-ethylhexyl phthalate (DEHP) in floor dust was associated with parental-reported rhino-conjunctivitis. After stratification by gender, this trend was found to only occur in boys. Furthermore, urinary mono-isobutyl phthalate was inversely associated with parental-reported wheeze in boys. DI dust of benzyl butyl phthalate (BBzP) and DEHP were significantly correlated with DI_BBzP and DI_DEHP, respectively. These correlations were stronger with floor than with multi-surface dust. Our results suggest that, among Japanese children, house dust from low surfaces, such as living room floors, might play a meaningful role in the indoor environmental exposure pathway for BBzP and DEHP. Copyright © 2016 Elsevier Ltd. All rights reserved.

  20. Exposure to violence among urban school-aged children: is it only on television?

    Science.gov (United States)

    Purugganan, O H; Stein, R E; Silver, E J; Benenson, B S

    2000-10-01

    To measure exposure to different types of violence among school-aged children in a primary care setting. Child interviews using an instrument measuring 4 types of exposure (direct victimization, witnessing, hearing reports, media). Violent acts measured include being beaten up, chased/threatened, robbed/mugged, stabbed/shot, killed. Pediatric primary care clinic of large urban hospital. Convenience sample of 175 children 9-12 years old and their mothers. A total of 53% of the children were boys, 55% were Hispanic, and 40% received public assistance. All children had been exposed to media violence. A total of 97% (170/175) had been exposed to more direct forms of violence; 77% had witnessed violence involving strangers; 49% had witnessed violence involving familiar persons; 49% had been direct victims; and 31% had witnessed someone being shot, stabbed, or killed. Exposure to violence was significantly associated with being male. Most school-aged children who visited a pediatric primary care clinic of a large urban hospital had directly experienced violence as witnesses and/or victims.

  1. Deoxynivalenol Exposure in Norway, Risk Assessments for Different Human Age Groups

    Science.gov (United States)

    Sundheim, Leif; Lillegaard, Inger Therese; Fæste, Christiane Kruse; Brantsæter, Anne-Lise; Brodal, Guro; Eriksen, Gunnar Sundstøl

    2017-01-01

    Deoxynivalenol (DON) is the most common mycotoxin in Norwegian cereals, and DON is detected in most samples of crude cereal grain and cereal food commodities such as flour, bran, and oat flakes. The Norwegian Scientific Committee for Food Safety assessed the risk for adverse effects of deoxynivalenol (DON) in different age groups of the domestic population. This review presents the main results from the risk assessment, supplemented with some recently published data. Impairment of the immune system together with reduced feed intake and weight gain are the critical effects of DON in experimental animals on which the current tolerable daily intake was established. Based on food consumption and occurrence data, the mean exposure to DON in years with low and high levels of DON in the flour, respectively, were in the range of or up to two times the Tolerable Daily Intake (TDI) in 1-year-old infants and 2-year-old children. In years with high mean DON concentration, the high (95th-percentile) exposure exceeded the TDI by up to 3.5 times in 1-, 2- , 4-, and 9-year-old children. The assessment concluded that exceeding the TDI in infants and children is of concern. The estimated dietary DON intakes in adolescent and adult populations are in the range of the TDI or below, and are not a health concern. Acute human exposure to DON is not of concern in any age group. PMID:28165414

  2. Deoxynivalenol Exposure in Norway, Risk Assessments for Different Human Age Groups

    Directory of Open Access Journals (Sweden)

    Leif Sundheim

    2017-02-01

    Full Text Available Deoxynivalenol (DON is the most common mycotoxin in Norwegian cereals, and DON is detected in most samples of crude cereal grain and cereal food commodities such as flour, bran, and oat flakes. The Norwegian Scientific Committee for Food Safety assessed the risk for adverse effects of deoxynivalenol (DON in different age groups of the domestic population. This review presents the main results from the risk assessment, supplemented with some recently published data. Impairment of the immune system together with reduced feed intake and weight gain are the critical effects of DON in experimental animals on which the current tolerable daily intake was established. Based on food consumption and occurrence data, the mean exposure to DON in years with low and high levels of DON in the flour, respectively, were in the range of or up to two times the Tolerable Daily Intake (TDI in 1-year-old infants and 2-year-old children. In years with high mean DON concentration, the high (95th-percentile exposure exceeded the TDI by up to 3.5 times in 1-, 2- , 4-, and 9-year-old children. The assessment concluded that exceeding the TDI in infants and children is of concern. The estimated dietary DON intakes in adolescent and adult populations are in the range of the TDI or below, and are not a health concern. Acute human exposure to DON is not of concern in any age group.

  3. Calculation of age-dependent effective doses for external exposure using the MCNP code

    International Nuclear Information System (INIS)

    Hung, Tran Van

    2013-01-01

    Age-dependent effective dose for external exposure to photons uniformly distributed in air were calculated. Firstly, organ doses were calculated with a series of age-specific MIRD-5 type phantoms using the Monte Carlo code MCNP. The calculations were performed for mono-energetic photon sources with source energies from 10 keV to 5 MeV and for phantoms of newborn, 1, 5, 10, and 15 years-old and adult. Then, the effective doses to the different age-phantoms from the mono-energetic photon sources were estimated based on the obtained organ doses. From the calculated results, it is shown that the effective doses depend on the body size; the effective doses in younger phantoms are higher than those in the older phantoms, especially below 100 keV. (orig.)

  4. Calculation of age-dependent effective doses for external exposure using the MCNP code

    Energy Technology Data Exchange (ETDEWEB)

    Hung, Tran Van [Research and Development Center for Radiation Technology, ThuDuc, HoChiMinh City (VT)

    2013-07-15

    Age-dependent effective dose for external exposure to photons uniformly distributed in air were calculated. Firstly, organ doses were calculated with a series of age-specific MIRD-5 type phantoms using the Monte Carlo code MCNP. The calculations were performed for mono-energetic photon sources with source energies from 10 keV to 5 MeV and for phantoms of newborn, 1, 5, 10, and 15 years-old and adult. Then, the effective doses to the different age-phantoms from the mono-energetic photon sources were estimated based on the obtained organ doses. From the calculated results, it is shown that the effective doses depend on the body size; the effective doses in younger phantoms are higher than those in the older phantoms, especially below 100 keV. (orig.)

  5. Reconstruction of the Exposure Histories of 20 Allan Hills Ordinary Chondrites on the Basis of Cosmogenic 10Be, 26Al, Noble Gases, and Cosmic Ray Tracks

    Science.gov (United States)

    Neupert, U.; Knauer, M.; Michel, R.; Loeken, Th.; Schultz, L.; Dittrich-Hannen, B.; Suter, M.; Kubik, P. W.; Metzler, K.; Romstedt, J.

    1995-09-01

    Twenty ordinary chondrites from the 1988/89 meteorite search (ALH 88004, 88008, 88010, 88011, 88013, 88016 to 88021, 88026 to 88031, 88033, 88039, 88042) [1,2] were investigated for 10Be and 26Al, and for He, Ne and Ar by accelerator and rare gas mass spectrometry, respectively. Cosmic ray tracks were measured in samples of ALH 88019. Using theoretical production rates calculated by a physical model [3] the experimental data are interpreted with respect to the reconstruction of the preatmospheric exposure conditions and exposure histories of the meteoroids. Ordinary chondrites are particularly well suited to exemplify the capabilities of an interpretation of many cosmogenic nuclides measured in one sample. Model calculations of GCR production rates were performed for 10Be, 26Al, 3He, 21Ne, 22Ne and 38Ar as reported elsewhere [4,5]. For all meteorites, except for ALH 88019, the cosmogenic nuclide data can be explained by simple one stage exposure histories between 3 Ma and 44 Ma in meteoroids with radii between 5 cm and 85 cm. Exposure ages were derived from cosmogenic 3He, 21Ne and 38Ar on the basis of the theoretical production rates as function of3He/21Ne and 22Ne/21Ne as well as on the empirical ones proposed by Eugster [6]. The average ratios of exposure ages determined from theoretical production rates to those calculated according to Eugster [6] were 1.08+/-0.11, 1.11+/-0.25 and 1.12+/-0.17 in case of 3He, 21Ne and 38Ar, respectively. Repeated measurements of 10Be and 26Al in ALH 88019 resulted in 10.4+/-1.3 dpm/kg and 5.6+/-0.5 dpm/kg, respectively. But, the cosmogenic rare gas concentrations point to a (single stage) exposure age of 39 Ma in a meteoroid. This is in accordance with a measured cosmic ray track density in olivine of 2.8 * 10^6 cm^-2. The samples are from depths betwen 3 cm and 8 cm. Based on the track data we obtain a minimum meteoroid radius of 8 cm. The low 10Be and 26Al cannot be explained by a one stage exposure history and a long

  6. The rate of X-ray-induced DNA double-strand break repair in the embryonic mouse brain is unaffected by exposure to 50 Hz magnetic fields.

    Science.gov (United States)

    Woodbine, Lisa; Haines, Jackie; Coster, Margaret; Barazzuol, Lara; Ainsbury, Elizabeth; Sienkiewicz, Zenon; Jeggo, Penny

    2015-06-01

    Following in utero exposure to low dose radiation (10-200 mGy), we recently observed a linear induction of DNA double-strand breaks (DSB) and activation of apoptosis in the embryonic neuronal stem/progenitor cell compartment. No significant induction of DSB or apoptosis was observed following exposure to magnetic fields (MF). In the present study, we exploited this in vivo system to examine whether exposure to MF before and after exposure to 100 mGy X-rays impacts upon DSB repair rates. 53BP1 foci were quantified following combined exposure to radiation and MF in the embryonic neuronal stem/progenitor cell compartment. Embryos were exposed in utero to 50 Hz MF at 300 μT for 3 h before and up to 9 h after exposure to 100 mGy X-rays. Controls included embryos exposed to MF or X-rays alone plus sham exposures. Exposure to MF before and after 100 mGy X-rays did not impact upon the rate of DSB repair in the embryonic neuronal stem cell compartment compared to repair rates following radiation exposure alone. We conclude that in this sensitive system MF do not exert any significant level of DNA damage and do not impede the repair of X-ray induced damage.

  7. On the radiation exposure dose and health management history during 50 years of x-ray working

    International Nuclear Information System (INIS)

    Yoshida, Tomihiro

    1981-01-01

    My X-ray working history has become 50 years at the end of April, 1980. At this chance, the following data were summarized; the case numbers of X-ray photographs (517,132 cases), total amounts of radiation exposure dose (66.85 roentgen) and the results of blood test, which were experienced during past 50 years. The amounts of exposure dose during 35 years till 1965 were measured using my own method, which measured the film blackening as 30 milli-roentgen per week by certain standard method. After 1966 till 1980, the exposure dose were recorded using that of the film-badge service of Nippon Hoan Yohin Kyokai. The total amounts of exposure dose during 50 years were about 1/4 of D = 5 (N - 18). The results of blood test during last 27 years were found to be normal values. Then, it is happy to say that my body has been protected completely, from radiation hazard as a result of taking radiation protection and checking blood test always at my daily radiation works. The data of my own experiences during 50 years are summarized and reported in this paper. (author)

  8. High-resolution short-exposure small-animal laboratory x-ray phase-contrast tomography

    Science.gov (United States)

    Larsson, Daniel H.; Vågberg, William; Yaroshenko, Andre; Yildirim, Ali Önder; Hertz, Hans M.

    2016-12-01

    X-ray computed tomography of small animals and their organs is an essential tool in basic and preclinical biomedical research. In both phase-contrast and absorption tomography high spatial resolution and short exposure times are of key importance. However, the observable spatial resolutions and achievable exposure times are presently limited by system parameters rather than more fundamental constraints like, e.g., dose. Here we demonstrate laboratory tomography with few-ten μm spatial resolution and few-minute exposure time at an acceptable dose for small-animal imaging, both with absorption contrast and phase contrast. The method relies on a magnifying imaging scheme in combination with a high-power small-spot liquid-metal-jet electron-impact source. The tomographic imaging is demonstrated on intact mouse, phantoms and excised lungs, both healthy and with pulmonary emphysema.

  9. Exposure to mercury among Spanish preschool children: Trend from birth to age four

    Energy Technology Data Exchange (ETDEWEB)

    Llop, Sabrina, E-mail: llop_sab@gva.es [Foundation for the Promotion of Health and Biomedical Research in the Valencian Region, FISABIO-Public Health, Av. Catalunya 21, 46020 Valencia (Spain); Spanish Consortium for Research on Epidemiology and Public Health (CIBERESP), Madrid (Spain); Murcia, Mario [Spanish Consortium for Research on Epidemiology and Public Health (CIBERESP), Madrid (Spain); Foundation for the Promotion of Health and Biomedical Research in the Valencian Region, FISABIO-Public Health, Av. Catalunya 21, 46020 Valencia (Spain); Aguinagalde, Xabier [Laboratorio de Salud Pública de Alava, Santiago 11, 01002 Vitoria Gasteiz (Spain); Vioque, Jesus [Spanish Consortium for Research on Epidemiology and Public Health (CIBERESP), Madrid (Spain); Universidad Miguel Hernandez, Avenida de Alicante KM 87, 03550 Sant Joan d´Alacant (Spain); Rebagliato, Marisa [Spanish Consortium for Research on Epidemiology and Public Health (CIBERESP), Madrid (Spain); Medicine Department, Jaume I University, Av. Vicent Sos Baynat, s/n, 12071 Castelló de la Plana (Spain); Cases, Amparo [Foundation for the Promotion of Health and Biomedical Research in the Valencian Region, FISABIO-Public Health, Av. Catalunya 21, 46020 Valencia (Spain); Iñiguez, Carmen; Lopez-Espinosa, Maria-Jose [Foundation for the Promotion of Health and Biomedical Research in the Valencian Region, FISABIO-Public Health, Av. Catalunya 21, 46020 Valencia (Spain); Spanish Consortium for Research on Epidemiology and Public Health (CIBERESP), Madrid (Spain); Amurrio, Ascensión [Laboratorio de Salud Pública de Alava, Santiago 11, 01002 Vitoria Gasteiz (Spain); María Navarrete-Muñoz, Eva [Spanish Consortium for Research on Epidemiology and Public Health (CIBERESP), Madrid (Spain); Universidad Miguel Hernandez, Avenida de Alicante KM 87, 03550 Sant Joan d´Alacant (Spain); and others

    2014-07-15

    The purpose of this study is to describe the total hair mercury concentrations and their determinants in preschool Spanish children, as well as to explore the trend in mercury exposure from birth to the age four. This evolution has been scarcely studied in other birth cohort studies. The study population was 580 four year old children participating in the INMA (i.e. Childhood and Environment) birth cohort study in Valencia (2008–2009). Total mercury concentration at age four was measured in hair samples by atomic absorption spectrometry. Fish consumption and other covariates were obtained by questionnaire. Multivariate linear regression models were conducted in order to explore the association between mercury exposure and fish consumption, socio-demographic characteristics and prenatal exposure to mercury. The geometric mean was 1.10 µg/g (95%CI: 1.02, 1.19). Nineteen percent of children had mercury concentrations above the equivalent to the Provisional Tolerable Weekly Intake proposed by WHO. Mercury concentration was associated with increasing maternal age, fish consumption and cord blood mercury levels, as well as decreasing parity. Children whose mothers worked had higher mercury levels than those with non working mothers. Swordfish, lean fish and canned fish were the fish categories most associated with hair mercury concentrations. We observed a decreasing trend in mercury concentrations between birth and age four. In conclusion, the children participating in this study had high hair mercury concentrations compared to reported studies on children from other European countries and similar to other countries with high fish consumption. The INMA study design allows the evaluation of the exposure to mercury longitudinally and enables this information to be used for biomonitoring purposes and dietary recommendations. - Highlights: • The geometric mean of hair Hg concentrations was 1.10 µg/g. • 19% of children had Hg concentrations above the RfD proposed by

  10. Cannabis exposure as an interactive cardiovascular risk factor and accelerant of organismal ageing: a longitudinal study.

    Science.gov (United States)

    Reece, Albert Stuart; Norman, Amanda; Hulse, Gary Kenneth

    2016-11-07

    Many reports exist of the cardiovascular toxicity of smoked cannabis but none of arterial stiffness measures or vascular age (VA). In view of its diverse toxicology, the possibility that cannabis-exposed patients may be ageing more quickly requires investigation. Cross-sectional and longitudinal, observational. Prospective. Single primary care addiction clinic in Brisbane, Australia. 11 cannabis-only smokers, 504 tobacco-only smokers, 114 tobacco and cannabis smokers and 534 non-smokers. known cardiovascular disease or therapy or acute exposure to alcohol, amphetamine, heroin or methadone. Radial arterial pulse wave tonometry (AtCor, SphygmoCor, Sydney) performed opportunistically and sequentially on patients between 2006 and 2011. Algorithmically calculated VA. other central haemodynamic variables. Differences between group chronological ages (CA, 30.47±0.48 to 40.36±2.44, mean±SEM) were controlled with linear regression. Between-group sex differences were controlled by single-sex analysis. Mean cannabis exposure among patients was 37.67±7.16 g-years. In regression models controlling for CA, Body Mass Index (BMI), time and inhalant group, the effect of cannabis use on VA was significant in males (p=0.0156) and females (p=0.0084). The effect size in males was 11.84%. A dose-response relationship was demonstrated with lifetime exposure (pcannabis was robust to adjustment and was unrelated to its acute effects. Significant power interactions between cannabis exposure and the square and cube of CA were demonstrated (from pCannabis is an interactive cardiovascular risk factor (additional to tobacco and opioids), shows a prominent dose-response effect and is robust to adjustment. Cannabis use is associated with an acceleration of the cardiovascular age, which is a powerful surrogate for the organismal-biological age. This likely underlies and bi-directionally interacts with its diverse toxicological profile and is of considerable public health and regulatory

  11. Exposure to mercury among Spanish preschool children: Trend from birth to age four

    International Nuclear Information System (INIS)

    Llop, Sabrina; Murcia, Mario; Aguinagalde, Xabier; Vioque, Jesus; Rebagliato, Marisa; Cases, Amparo; Iñiguez, Carmen; Lopez-Espinosa, Maria-Jose; Amurrio, Ascensión; María Navarrete-Muñoz, Eva

    2014-01-01

    The purpose of this study is to describe the total hair mercury concentrations and their determinants in preschool Spanish children, as well as to explore the trend in mercury exposure from birth to the age four. This evolution has been scarcely studied in other birth cohort studies. The study population was 580 four year old children participating in the INMA (i.e. Childhood and Environment) birth cohort study in Valencia (2008–2009). Total mercury concentration at age four was measured in hair samples by atomic absorption spectrometry. Fish consumption and other covariates were obtained by questionnaire. Multivariate linear regression models were conducted in order to explore the association between mercury exposure and fish consumption, socio-demographic characteristics and prenatal exposure to mercury. The geometric mean was 1.10 µg/g (95%CI: 1.02, 1.19). Nineteen percent of children had mercury concentrations above the equivalent to the Provisional Tolerable Weekly Intake proposed by WHO. Mercury concentration was associated with increasing maternal age, fish consumption and cord blood mercury levels, as well as decreasing parity. Children whose mothers worked had higher mercury levels than those with non working mothers. Swordfish, lean fish and canned fish were the fish categories most associated with hair mercury concentrations. We observed a decreasing trend in mercury concentrations between birth and age four. In conclusion, the children participating in this study had high hair mercury concentrations compared to reported studies on children from other European countries and similar to other countries with high fish consumption. The INMA study design allows the evaluation of the exposure to mercury longitudinally and enables this information to be used for biomonitoring purposes and dietary recommendations. - Highlights: • The geometric mean of hair Hg concentrations was 1.10 µg/g. • 19% of children had Hg concentrations above the RfD proposed by

  12. Age and sex-specific relationships between phthalate exposures and obesity in Chinese children at puberty.

    Directory of Open Access Journals (Sweden)

    Yunhui Zhang

    Full Text Available To examine the age and sex-specific associations of urine levels of six mono-phthalates with body size and fat distribution in Chinese children at puberty.Four hundred and ninety-three school-aged children (247 boys, 246 girls were recruited. Obesity related anthropometric indices were measured and body fat proportion (BF% was calculated. Spot urine samples were collected and phthalate monoesters were detected by an API 2000 electrospray triple quadrupole mass spectrometer (ESI-MS/MS. Associations between phthalate exposure and overweight/obesity measures and their trends were examined by multiple linear regression and Logistic regression analyses, respectively.Di-2-ethylhexyl phthalate (DEHP metabolites and monobutyl phthalate (MBP were found to be the most detectable chemicals. In 8-10 years (yrs group, concentrations of MEHP and MBP were significantly higher in girls than those in boys. However, concentrations of all phthalate monoesters, except for MEP and MEHP, in 11-13 yrs boys were significantly higher than those in girls. After adjusting for confounders including puberty onset, urinary concentrations of MBP and sum of low molecular-weight phthalate metabolites (∑LMP were positively associated with boys' obesity in a concentration-effect manner, while concentrations of MEHP, MEHHP and sum of DEHP metabolites (∑MEHP were negatively associated with girls' obesity. Associations between phthalate exposure levels and BMI z-score changes were age- and sex-specific in school-age children.There are age and sex-specific concentration-effect associations between phthalate exposure and fat distribution in Chinese children. Urinary phthalate levels in 11-13 yrs boys were about 30 percent higher than those in girls, and ∑MEHP levels in younger boys (10 yrs. Associations were positive for MBP and ∑LMP with both BMI z-score and fat distribution in boys >10 years of age, and negative for ∑MEHP with fat distribution in girls <10 years of age.

  13. Cellular changes in the hamster testicular interstitium with ageing and after exposure to short photoperiod.

    Science.gov (United States)

    Beltrán-Frutos, E; Seco-Rovira, V; Ferrer, C; Madrid, J F; Sáez, F J; Canteras, M; Pastor, L M

    2016-04-01

    The aim of this study was to evaluate the cellular changes that occur in the hamster testicular interstitium in two very different physiological situations involving testicular involution: ageing and exposure to a short photoperiod. The animals were divided into an 'age group' with three subgroups - young, adult and old animals - and a 'regressed group' with animals subjected to a short photoperiod. The testicular interstitium was characterised by light and electron microscopy. Interstitial cells were studied histochemically with regard to their proliferation, terminal deoxynucleotidyl transferase (TdT)-mediated dUTP in situ nick end labelling (TUNEL+) and testosterone synthetic activity. We identified two types of Leydig cell: Type A cells showed a normal morphology, while Type B cells appeared necrotic. With ageing, pericyte proliferation decreased but there was no variation in the index of TUNEL-positive Leydig cells. In the regressed group, pericyte proliferation was greater and TUNEL-positive cells were not observed in the interstitium. The testicular interstitium suffered few ultrastructural changes during ageing and necrotic Leydig cells were observed. In contrast, an ultrastructural involution of Leydig cells with no necrosis was observed in the regressed group. In conclusion, the testicular interstitium of Mesocricetus auratus showed different cellular changes in the two groups (age and regressed), probably due to the irreversible nature of ageing and the reversible character of changes induced by short photoperiod.

  14. Sensitivity of continuous performance test (CPT) at age 14years to developmental methylmercury exposure

    DEFF Research Database (Denmark)

    Julvez, Jordi; Debes, Frodi; Weihe, Pal

    2010-01-01

    Hit Reaction Time latencies (HRT) in the Continuous Performance Test (CPT) measure the speed of visual information processing. The latencies may involve different neuropsychological functions depending on the time from test initiation, i.e., first orientation, learning and habituation, then cogni......Hit Reaction Time latencies (HRT) in the Continuous Performance Test (CPT) measure the speed of visual information processing. The latencies may involve different neuropsychological functions depending on the time from test initiation, i.e., first orientation, learning and habituation......, then cognitive processing and focused attention, and finally sustained attention as the dominant demand. Prenatal methylmercury exposure is associated with increased reaction time (RT) latencies. We therefore examined the association of methylmercury exposure with the average HRT at age 14years at three...

  15. Premature reproductive aging in female rats after developmental exposure to mixtures of endocrine disrupters

    DEFF Research Database (Denmark)

    Jacobsen, Pernille Rosenskjold; Petersen, Marta Axelstad; Christiansen, Sofie

    2013-01-01

    of 13 estrogenic and anti-androgenic chemicals, including phthalates, pesticides, UV-filters, bisphenol A, butylparaben and paracetamol, and the mixture ratio was chosen to reflect high-end human intakes. Groups received combined exposures of 0,100, 150, 200 or 450 times high-end human intake levels......Long-lasting and delayed reproductive effects of developmental exposure to mixtures of environmental chemicals were investigated in female rats. Wistar rats were dosed during gestation and lactation to mixtures of endocrine disrupters, and effects in offspring were studied. The mixtures consisted....... Additionally, groups received mixtures including only the anti-androgens or estrogens at 200 or 450 times human intake. Female offspring exposed to the high dose mixture of all 13 chemicals showed earlier reproductive aging measured as early onset of irregular estrous cycle as compared to controls...

  16. Investigation of organ dose difference of age phantoms for medical X-ray examinations

    International Nuclear Information System (INIS)

    Park, Sang Hyun; Kim, Woo Ran; Lee, Jai Ki; Lee, Choon Sik

    2003-01-01

    Methodology for calculating the organ equivalent doses and the effective doses of pediatric and adult patients undergoing medical X-ray examinations were established. The MIRD-type mathematical phantoms of 4 age groups were constructed with addition of the esophagus to the same phantoms. Two typical examination procedures, chest PA and abdomen AP, were simulated for the pediatric patients as well as the adult as illustrative examples. The results confirmed that patients pick up approximate 0.03 mSv of effective dose from a single chest PA examination, and 0.4 to 1.7 mSv from an abdomen AP examination depending on the ages. For dose calculations where irradiation is made with a limited field, the details of the position, size and shape of the organs and the organ depth from the entrance surface considerably affect the resulting doses. Therefore, it is important to optimize radiation protection by control of X-ray properties and beam examination field. The calculation result, provided in this study, can be used to implement optimization for medical radiation protection

  17. Gender and age differences in mixed metal exposure and urinary excretion

    International Nuclear Information System (INIS)

    Berglund, Marika; Lindberg, Anna-Lena; Rahman, Mahfuzar; Yunus, Mohammad; Grandér, Margaretha; Lönnerdal, Bo; Vahter, Marie

    2011-01-01

    Background: Little is known about the variation in exposure to toxic metals by age and gender and other potential modifying factors. We evaluated age and gender differences by measurements of metal/element concentrations in urine in a rural population in Matlab, Bangladesh, in three age groups: 8–12 (N=238), 14–15 (N=107) and 30–88 (N=710) years of age, living in an area with no point sources of metal exposure but where elevated water arsenic concentrations are prevalent. Results: We found marked differences in urine concentrations of metals and trace elements by gender, age, tobacco use, socioeconomic and nutritional status. Besides a clearly elevated urinary arsenic concentration in all age groups (medians 63–85 μg As/L), and despite the low degree of contamination from industries and traffic, the urine concentrations of toxic metals such as cadmium and lead were clearly elevated, especially in children (median 0.31 μg Cd/L and 2.9 μg Pb/L, respectively). In general, women had higher urinary concentrations of toxic metals, especially Cd (median 0.81 μg/L) compared to men (0.66 μg/L) and U (median 10 ng/L in women, compared to 6.4 ng/L in men), while men had higher urinary concentrations of the basic and essential elements Ca (69 mg/L in men, 30–50 years, compared to 52 mg/L in women), Mg (58 mg/L in men compared to 50 mg/L in women), Zn (182 μg/L in men compared to 117 μg/L in women) and Se (9.9 μg/L in men compared to 8.7 μg/L in women). Manganese was consistently higher in females than in males in all age groups, suggesting a biological difference between females and males in Mn metabolism. Increasing socioeconomic status decreased the toxic metal exposure significantly in children and especially in men. Poor iron status was detected in 17% of children, adolescents and women, but only in 6% of men. Also zinc deficiency was more prevalent in females than in males. Conclusions: Women and children seemed to be more at risk for toxic metal

  18. Gender and age differences in mixed metal exposure and urinary excretion

    Energy Technology Data Exchange (ETDEWEB)

    Berglund, Marika, E-mail: Marika.Berglund@ki.se [Institute of Environmental Medicine, Karolinska Institutet, Stockholm (Sweden); Lindberg, Anna-Lena [Institute of Environmental Medicine, Karolinska Institutet, Stockholm (Sweden); Rahman, Mahfuzar; Yunus, Mohammad [International Centre for Diarrhoeal Disease Research (Bangladesh); Grander, Margaretha [Institute of Environmental Medicine, Karolinska Institutet, Stockholm (Sweden); Loennerdal, Bo [Department of Nutrition, University of California, Davis, CA 95616 (United States); Vahter, Marie [Institute of Environmental Medicine, Karolinska Institutet, Stockholm (Sweden)

    2011-11-15

    Background: Little is known about the variation in exposure to toxic metals by age and gender and other potential modifying factors. We evaluated age and gender differences by measurements of metal/element concentrations in urine in a rural population in Matlab, Bangladesh, in three age groups: 8-12 (N=238), 14-15 (N=107) and 30-88 (N=710) years of age, living in an area with no point sources of metal exposure but where elevated water arsenic concentrations are prevalent. Results: We found marked differences in urine concentrations of metals and trace elements by gender, age, tobacco use, socioeconomic and nutritional status. Besides a clearly elevated urinary arsenic concentration in all age groups (medians 63-85 {mu}g As/L), and despite the low degree of contamination from industries and traffic, the urine concentrations of toxic metals such as cadmium and lead were clearly elevated, especially in children (median 0.31 {mu}g Cd/L and 2.9 {mu}g Pb/L, respectively). In general, women had higher urinary concentrations of toxic metals, especially Cd (median 0.81 {mu}g/L) compared to men (0.66 {mu}g/L) and U (median 10 ng/L in women, compared to 6.4 ng/L in men), while men had higher urinary concentrations of the basic and essential elements Ca (69 mg/L in men, 30-50 years, compared to 52 mg/L in women), Mg (58 mg/L in men compared to 50 mg/L in women), Zn (182 {mu}g/L in men compared to 117 {mu}g/L in women) and Se (9.9 {mu}g/L in men compared to 8.7 {mu}g/L in women). Manganese was consistently higher in females than in males in all age groups, suggesting a biological difference between females and males in Mn metabolism. Increasing socioeconomic status decreased the toxic metal exposure significantly in children and especially in men. Poor iron status was detected in 17% of children, adolescents and women, but only in 6% of men. Also zinc deficiency was more prevalent in females than in males. Conclusions: Women and children seemed to be more at risk for toxic

  19. No association between prenatal exposure to psychotropics and intelligence at age five.

    Science.gov (United States)

    Eriksen, Hanne-Lise Falgreen; Kesmodel, Ulrik Schiøler; Pedersen, Lars Henning; Mortensen, Erik Lykke

    2015-05-01

    To examine associations between prenatal exposure to selective serotonin reuptake inhibitors (SSRIs)/anxiolytics and intelligence assessed with a standard clinical intelligence test at age 5 years. Longitudinal follow-up study. Denmark, 2003-2008. A total of 1780 women and their children sampled from the Danish National Birth Cohort. Self-reported information on use of SSRI and anxiolytics was obtained from the Danish National Birth Cohort at the time of consent and from two prenatal interviews. Intelligence was assessed at age 5 years, and parental education, maternal intelligence quotient (IQ), maternal smoking and alcohol consumption in pregnancy, the child's age at testing, sex, and tester were included in the full model. The IQ of 13 medication-exposed children was compared with the IQ of 19 children whose mothers had untreated depression and 1748 control children. Wechsler Preschool and Primary Scale of Intelligence - Revised. In unadjusted analyses, children of mothers who used antidepressants or anxiolytics during pregnancy had higher verbal IQ; this association, however, was insignificant after adjustment for potentially confounding maternal and child factors. No consistent associations between IQ and fetal exposure to antidepressants and anxiolytics were observed, but the study had low statistical power, and there is an obvious need to conduct long-term follow-up studies with comprehensive cognitive assessment and sufficiently large samples of adolescent or adult offspring. © 2015 Nordic Federation of Societies of Obstetrics and Gynecology.

  20. [Socioeconomic status, eating patterns, and heavy metals exposure in women of childbearing age in Cali, Colombia].

    Science.gov (United States)

    Figueroa, Roger; Caicedo, Diana; Echeverry, Ghisliane; Peña, Miguel; Méndez, Fabián

    2017-09-01

    Global increase in food and water pollution is associated with health risk, which depends on the concentration, the dose, and the exposure time. This has raised concerns about the possible long-term effects of chronic exposure to low concentrations of heavy metals, such as lead, cadmium and mercury. To explore the relationship among socioeconomic status, eating patterns, and exposure to heavy metals among a population of women in Cali, Colombia. A total of 233 non-pregnant women of childbearing age living in the Aguablanca district of Cali, Colombia, were enrolled in the study. We gathered sociodemographic data, as well as information on housing conditions, exposure to heavy metals, frequency of food intake, and anthropometric measurements. Samples of lettuce, cabbage and fish (tilapia and butterfish) were collected to determine lead, cadmium, and mercury concentrations. Descriptive and multiple correspondence analyses were performed to establish eating patterns. Fish was served in each of the three main meals of the day, with a bigger serving at lunch time. Cadmium was found in three samples of butterfish at levels below the acceptable. Of those who ate fish more than once a week, 11.1% bought the product at a cadmium-positive store. The multiple correspondence analysis showed a positive relationship between being black and consuming butterfish and tilapia more than once per week. The findings showed that the studied population had access to heavy metal-contaminated food, which combined with the women's cultural eating patterns, socioeconomic status, and metabolic characteristics led to a greater vulnerability to the effects of heavy metals exposure.

  1. Perinatal dioxin exposure and the neurodevelopment of Vietnamese toddlers at 1 year of age.

    Science.gov (United States)

    Pham, Tai The; Nishijo, Muneko; Nguyen, Anh Thi Nguyet; Tran, Nghi Ngoc; Hoang, Luong Van; Tran, Anh Hai; Nguyen, Trung Viet; Nishijo, Hisao

    2015-12-01

    Dioxin concentrations remain elevated in both the environment and in humans residing near former US Air Force bases in South Vietnam. This may potentially have adverse health effects, particularly on infant neurodevelopment. We followed 214 infants whose mothers resided in a dioxin-contaminated area in Da Nang, Vietnam, from birth until 1 year of age. Perinatal exposure to dioxins was estimated from toxic equivalent (TEQ) levels of polychlorinated dibenzodioxins and polychlorinated dibenzofurans (PCDDs/Fs-TEQ), and 2,3,7,8-tetrachlorodibenzo-p-dioxin (2,3,7,8-TetraCDD) concentrations in breast milk. In infants, daily dioxin intake (DDI) was used as an index of postnatal exposure through breastfeeding. Neurodevelopment of toddlers was assessed using the Bayley Scales of Infant and Toddler Development, Third Edition (Bayley-III). No significant differences in neurodevelopmental scores were exhibited for cognitive, language or motor functions between four exposure groups of PCDDs/Fs-TEQ or 2,3,7,8-TetraCDD. However, social-emotional scores were decreased in the high PCDDs/Fs-TEQ group and the high 2,3,7,8-TetraCDD group compared with those with mild exposure, after adjusting for confounding factors. Cognitive scores in the mild, moderate, and high DDI groups were significantly higher than those in low DDI group, but there were no differences in cognitive scores among the three higher DDI groups. These results suggest that perinatal exposure to dioxins may affect social-emotional development of 1-year-old toddlers, without diminishing global neurodevelopmental function. Crown Copyright © 2015. Published by Elsevier B.V. All rights reserved.

  2. Pesticide-related poison center exposures in children and adolescents aged ≤19 years in Texas, 2000-2013.

    Science.gov (United States)

    Trueblood, Amber B; Forrester, Mathias B; Han, Daikwon; Shipp, Eva M; Cizmas, Leslie H

    2016-11-01

    Although national poison center data show that pesticides were the 8th most commonly reported substance category (3.27%) for children aged ≤5 years in 2014, there is limited information on childhood and adolescent pesticide exposures. This study assessed pesticide-related poison center exposures in children and adolescents aged ≤19 years from 2000-2013 in Texas to characterize the potential burden of pesticides. Pesticide-related poison center exposures among children and adolescents aged ≤19 years reported to Texas poison centers were identified. The distribution of exposures was estimated by gender, age category, medical outcome, management site, exposure route, and pesticide category. From 2000 to 2013, there were 61,147 pesticide-related poison center exposures in children and adolescents aged ≤19 years. The prevalence was highest among males at 864.24 per 100,000 population. The prevalence of unintentional exposures was highest among children aged ≤5 years at 2310.69 per 100,000 population, whereas the prevalence of intentional exposures was highest among adolescents aged 13-19 years at 13.82 per 100,000 population. A majority of medical outcomes reported were classified as having no effect (30.24%) and not followed, but minimal clinical effects possible (42.74%). Of all the exposures, 81.24% were managed on site. However, 57% of intentional exposures were referred to or treated at a health-care facility. The most common routes of exposure were ingestion (80.83%) and dermal (17.21%). The most common pesticide categories included rodenticides (30.02%), pyrethrins/pyrethroids (20.69%), and other and unspecified insecticides (18.14%). The study found differences in the frequency of exposures by intent for sex and age categories, and identified the most common medical outcomes, management site, exposure route, and pesticide category. Through characterizing pesticide-related poison center exposures, future interventions can be designed to address groups

  3. Secondhand Smoke Exposure Reduced the Compensatory Effects of IGF-I Growth Signaling in the Aging Rat Hearts.

    Science.gov (United States)

    Wu, Jia-Ping; Hsieh, Dennis Jine-Yuan; Kuo, Wei-Wen; Han, Chien-Kuo; Pai, Peiying; Yeh, Yu-Lan; Lin, Chien-Chung; Padma, V Vijaya; Day, Cecilia Hsuan; Huang, Chih-Yang

    2015-01-01

    Secondhand smoke (SHS) exposure is associated with increased risk of cardiovascular disease. Aging is a physiological process that involves progressive impairment of normal heart functions due to increased vulnerability to damage. This study examines secondhand smoke exposure in aging rats to determine the age-related death-survival balance. Rats were placed into a SHS exposure chamber and exposed to smog. Old age male Sprague-Dawley rats were exposed to 10 cigarettes for 30 min, day and night, continuing for one week. After 4 weeks the rats underwent morphological and functional studies. Left ventricular sections were stained with hematoxylin-eosin for histopathological examination. TUNEL detected apoptosis cells and protein expression related death and survival pathway were analyzed using western blot. Death receptor-dependent apoptosis upregulation pathways and the mitochondria apoptosis proteins were apparent in young SHS exposure and old age rats. These biological markers were enhanced in aging SHS-exposed rats. The survival pathway was found to exhibit compensation only in young SHS-exposed rats, but not in the aging rats. Further decrease in the activity of this pathway was observed in aging SHS-exposed rats. TUNEL apoptotic positive cells were increased in young SHS-exposed rats, and in aging rats with or without SHS-exposure. Aging reduces IGF-I compensated signaling with accelerated cardiac apoptotic effects from second-hand smoke.

  4. Perinatal dioxin exposure and psychosocial and behavioral development in school-aged children.

    Science.gov (United States)

    Kono, Yumi; Oka, Akira; Tada, Hiroshi; Itabashi, Kazuo; Matsui, Eiko; Nakamura, Yosikazu

    2015-09-01

    The aim of this study was to elucidate the association between psychosocial and behavioral problems in children at school age and dioxin level in breast milk or estimated dioxin exposure (EDE) through breastfeeding in the general Japanese population. Dioxin level of breast milk at 1month of age and breastfeeding ratio through the first year of life were used to calculate the EDE of infants born in 1998-2005 in Japan. The Japanese Social Difficulties Questionnaire (SDQ) for the assessment of children's behavior was sent by mail to mothers whose breast milk underwent the dioxin survey, at the time when their infants were aged 6-13 years. The study subjects were 175 pairs of mothers and their first infants (79 boys, 96 girls). The mean total dioxin levels of breast milk were 18.3 and 19.8 (pgTEQ/g fat) and EDEs were 16.4 and 19.6 (ngTEQ/kg/year) in boys and girls, respectively. In linear multiple regression analyses after adjusting for age at SDQ, maternal age, birth weight and maternal smoking habit, dioxin level in breast milk was not significantly related to the total difficulties score (TDS) of SDQ in boys, B=2.29 (95% CI -7.60-12.18), or in girls, B=-1.04 (95% CI -9.24-7.15). EDE correlated to the TDS in neither boys, B=-0.99 (95% CI -4.14-2.15), nor girls, B=1.08 (95% CI -2.69-4.85). No evidence was found of a correlation between perinatal dioxin exposure and behavioral and psychosocial problems of children measured by SDQ. These results support the benefits of recommending breastfeeding. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  5. Environmental Tobacco Smoke Exposure and Children’s Intelligence at 8–11 Years of Age

    Science.gov (United States)

    Park, Subin; Cho, Soo-Churl; Hong, Yun-Chul; Shin, Min-Sup; Yoo, Hee Jeong; Han, Doug Hyun; Cheong, Jae Hoon

    2014-01-01

    Background: Evidence supporting a link between postnatal environmental tobacco smoke (ETS) exposure and cognitive problems among children is mounting, but inconsistent. Objectives: We examined the relationship between ETS exposure, measured using urine cotinine, and IQ scores in Korean school-aged children. Methods: The participants were 996 children 8–11 years of age recruited from five administrative regions in South Korea. We performed a cross-sectional analysis of urinary cotinine concentrations and IQ scores obtained using the abbreviated form of a Korean version of the Wechsler Intelligence Scales for Children. Associations were adjusted for potential confounders, and estimates were derived with and without adjustment for mother’s Full-Scale IQ (FSIQ) score. Results: After adjusting for sociodemographic and developmental covariates, urinary cotinine concentrations were inversely associated with FSIQ, Verbal IQ (VIQ), Performance IQ (PIQ), vocabulary, math, and block design scores. Following further adjustment for maternal IQ, only the VIQ scores remained significantly associated with urinary cotinine concentration (B = –0.31; 95% CI: –0.60, –0.03 for a 1-unit increase in natural log-transformed urine cotinine concentration; p = 0.03). Conclusion: Urine cotinine concentrations were inversely associated with children’s VIQ scores before and after adjusting for maternal IQ. Further prospective studies with serial measurements of cotinine are needed to confirm our findings. Citation: Park S, Cho SC, Hong YC, Kim JW, Shin MS, Yoo HJ, Han DH, Cheong JH, Kim BN. 2014. Environmental tobacco smoke exposure and children’s intelligence at 8–11 years of age. Environ Health Perspect 122:1123–1128; http://dx.doi.org/10.1289/ehp.1307088 PMID:24911003

  6. Fetal magnetic resonance imaging: exposure times and functional outcomes at preschool age

    Energy Technology Data Exchange (ETDEWEB)

    Bouyssi-Kobar, Marine [George Washington University, Institute for Biomedical Sciences, Washington, DC (United States); Children' s National Health System, Advanced Pediatric Brain Imaging Research Laboratory, Departments of Diagnostic Imaging and Radiology, Washington, DC (United States); Du Plessis, Adre J. [Children' s National Health System, Fetal and Transitional Medicine, Washington, DC (United States); Robertson, Richard L. [Children' s Hospital Boston and Harvard Medical School, Department of Radiology, Boston, MA (United States); Limperopoulos, Catherine [Children' s National Health System, Advanced Pediatric Brain Imaging Research Laboratory, Departments of Diagnostic Imaging and Radiology, Washington, DC (United States); Children' s National Health System, Fetal and Transitional Medicine, Washington, DC (United States)

    2015-11-15

    Fetal magnetic resonance imaging (MRI) has been routinely used as a noninvasive diagnostic tool for more than a decade; however, there is a paucity of follow-up studies examining the effects of prenatal exposure to 1.5-T MRI on developmental outcome. The objective of this study was to assess the safety of 1.5-T fetal MRI by evaluating functional outcomes of preschool children who were exposed in utero. In the context of a prospective observational study, healthy pregnant women underwent a 1.5-T MRI study using single-shot fast spin echo (SSFSE) sequences during the second or third trimester of pregnancy. The study was approved by the institutional review board at our institution, and written informed consent was obtained from all study participants. MRI scanning times were recorded, and prenatal/postnatal clinical data were collected prospectively. Functional outcomes were assessed using the Vineland Adaptive Behavior Scale (VABS), a widely used, norm-referenced and psychometrically sound functional assessment. We studied 72 healthy pregnant women, who underwent fetal MRI at a mean gestational age of 30.5 ± 3.1 weeks. The cohort of fetuses was composed of 43% females, and 18 fetuses were scanned during the second trimester. All fetuses were born at term with appropriate birth weights (3.54 ± 0.5 kg) for gestational age. Mean age at follow-up testing was 24.5 ± 6.7 months. All children had age-appropriate scores in the communication, daily living, socialization and motor skills subdomains of the VABS (z-scores, P > 0.05). Furthermore, all children passed their newborn otoacoustic emission test and had normal hearing at preschool age. MRI study duration and exposure time to radio frequency waves and SSFSE sequences were not associated with adverse functional outcomes or hearing impairment. Prenatal exposure to 1.5-T MRI during the second or third trimester of pregnancy in a cohort of healthy fetuses is not associated with disturbances in functional outcomes or

  7. Fetal magnetic resonance imaging: exposure times and functional outcomes at preschool age

    International Nuclear Information System (INIS)

    Bouyssi-Kobar, Marine; Du Plessis, Adre J.; Robertson, Richard L.; Limperopoulos, Catherine

    2015-01-01

    Fetal magnetic resonance imaging (MRI) has been routinely used as a noninvasive diagnostic tool for more than a decade; however, there is a paucity of follow-up studies examining the effects of prenatal exposure to 1.5-T MRI on developmental outcome. The objective of this study was to assess the safety of 1.5-T fetal MRI by evaluating functional outcomes of preschool children who were exposed in utero. In the context of a prospective observational study, healthy pregnant women underwent a 1.5-T MRI study using single-shot fast spin echo (SSFSE) sequences during the second or third trimester of pregnancy. The study was approved by the institutional review board at our institution, and written informed consent was obtained from all study participants. MRI scanning times were recorded, and prenatal/postnatal clinical data were collected prospectively. Functional outcomes were assessed using the Vineland Adaptive Behavior Scale (VABS), a widely used, norm-referenced and psychometrically sound functional assessment. We studied 72 healthy pregnant women, who underwent fetal MRI at a mean gestational age of 30.5 ± 3.1 weeks. The cohort of fetuses was composed of 43% females, and 18 fetuses were scanned during the second trimester. All fetuses were born at term with appropriate birth weights (3.54 ± 0.5 kg) for gestational age. Mean age at follow-up testing was 24.5 ± 6.7 months. All children had age-appropriate scores in the communication, daily living, socialization and motor skills subdomains of the VABS (z-scores, P > 0.05). Furthermore, all children passed their newborn otoacoustic emission test and had normal hearing at preschool age. MRI study duration and exposure time to radio frequency waves and SSFSE sequences were not associated with adverse functional outcomes or hearing impairment. Prenatal exposure to 1.5-T MRI during the second or third trimester of pregnancy in a cohort of healthy fetuses is not associated with disturbances in functional outcomes or

  8. Radiation exposure and image quality in X-ray diagnostic radiology. Physical principles and clinical applications. 2. ed.

    International Nuclear Information System (INIS)

    Saebel, Manfred; Aichinger, Horst; Dierker, Joachim; Joite-Barfuss, Sigrid

    2012-01-01

    Diagnostic X-rays are the largest contributor to radiation exposure to the general population, and protecting the patient from radiation damage is a major aim of modern health policy. Once the decision has been taken to use ionising radiation for imaging in a particular patient, it is necessary to optimize the image acquisition process taking into account the diagnostic quality of the images and the radiation dose to the patient. Both image quality and radiation dose are affected by a number of parameters, knowledge of which permits scientifically based decision making. The authors of this second edition of Radiation Exposure and Image Quality in X-ray Diagnostic Radiology have spent many years studying the optimization of radiological imaging. In this book they present in detail the basic physical principles of diagnostic radiology and their application to clinical problems. Particular attention is devoted to evaluation of the dose to the patient, the influence of scattered radiation on image quality, the use of antiscatter grids, and optimization of image quality and dose. The final section is a supplement containing tables of data and graphical depictions of X-ray spectra, interaction coefficients, characteristics of X-ray beams, and other aspects relevant to patient dose calculations. In addition, a complementary CD-ROM contains a user-friendly Excel file database covering these aspects that can be used in the reader's own programs. Since the first edition, the text, figures, tables, and references have all been thoroughly updated, and more detailed attention is now paid to image quality and radiation exposure when using digital imaging and computed tomography. This book will be an invaluable aid to medical physicists when performing calculations relating to patient dose and image quality, and will also prove useful for diagnostic radiologists and engineers. (orig.)

  9. Deposition of inhaled particles in the respiratory tract as a function of age at exposure

    International Nuclear Information System (INIS)

    Thomas, R.G.; Healy, J.W.

    1985-01-01

    A respiratory tract deposition model was developed that would accommodate age 1 month to adulthood as an initial step in calculating radiation dose following inhalation during environmental exposures. The approach to changing respiratory tract and physiological parameters to be applicable to children was to derive an analytical function describing the ratio of the child value to the value for a reference adult with the desired characteristics. A computer program was written to carry out the tracing of airflow through the respiratory tract and deposition in each of the sections for monodispersed particles of known density and diameter. 7 references

  10. Malformation of the cerebral cortex of rats caused by embryonal exposure to x-ray

    Energy Technology Data Exchange (ETDEWEB)

    Inoue, M [Nagoya Univ. (Japan). Research Inst. of Environmental Medicine

    1978-03-01

    200 R x-ray was irradiated to rat embryos, 17 days of age, and changes of the brain were observed histologically from one hour after the irradiation until they grew up. At start, there was not a great damage in the formation of bundles of major and minor hemisphere commissure passing through the terminal plate, although many cells died or fell off in the new brain mantle. After that, callosal fibers did not reach the midline because of the tissue destruction around the midline, and growth of the stem of the corpus callosum was pressed down. Defect of the stem of the corpus callosum was recognized in adult rats. Surviving mother cells gathered irregularly on the wall of the ventricle at the time of the repair of destructed tissues, and they remained as they stood around the midline of the brain mantle without rearrangement. In adult rats, there was abnormal formation of the cerebral cortex within medullary substances. Marked hypoplasia was recognized in the II-IV layer of the new cortex, bundle branches of dendritic processes of pyramidal cells in the V layer were small in number, and the directions of dendritic processes were abnormal. Pyramidal cell layer of the hippocampus fell into disorder and the directions of dendritic processes were irregular. It was demonstrated by the measurement of cubic volume of each part of the brain using reconstruction method that not only marked hypoplasia of the new cortex and the hippocampus but also hypoplasia of the old cortex, the basal ganglion, and the thalamus in which it was thought to be little disorder in the past were clear.

  11. Malformation of the cerebral cortex of rats caused by embryonal exposure to x-ray

    International Nuclear Information System (INIS)

    Inoue, Minoru

    1978-01-01

    200 R x-ray was irradiated to rat embryos, 17 days of age, and changes of the brain were observed histologically from one hour after the irradiation until they grew up. At start, there was not a great damage in the formation of bundles of major and minor hemisphere commissure passing through the terminal plate, although many cells died or fell off in the new brain mantle. After that, callosal fibers did not reach the midline because of the tissue destruction around the midline, and growth of the stem of the corpus callosum was pressed down. Defect of the stem of the corpus callosum was recognized in adult rats. Surviving mother cells gathered irregularly on the wall of the ventricle at the time of the repair of destructed tissues, and they remained as they stood around the midline of the brain mantle without rearrangement. In adult rats, there was abnormal formation of the cerebral cortex within medullary substances. Marked hypoplasia was recognized in the II-IV layer of the new cortex, bundle branches of dendritic processes of pyramidal cells in the V layer were small in number, and the directions of dendritic processes were abnormal. Pyramidal cell layer of the hippocampus fell into disorder and the directions of dendritic processes were irregular. It was demonstrated by the measurement of cubic volume of each part of the brain using reconstruction method that not only marked hypoplasia of the new cortex and the hippocampus but also hypoplasia of the old cortex, the basal ganglion, and the thalamus in which it was thought to be little disorder in the past were clear. (Iwagami, H.)

  12. Aberrant cell divisions in root meristeme of maize following exposure to X-rays low doses compared to similar effects of 50 Hz electromagnetic exposure

    Directory of Open Access Journals (Sweden)

    Luchian T.

    2012-04-01

    Full Text Available The response of maize to radiation exposure was investigated by two cytogenetic methods considering the importance of the geno-toxic effect for environmental and agricultural purposes. Uniform genophond seeds, freshly germinated, were exposed to relatively low radiation doses using a radiotherapy X-ray applicator from a hospital irradiation device and to a 50 Hz electromagnetic field with about 10 mT magnetic induction (generated within laboratory assembled electromagnetic coils. Radicular meristeme tissue aliquots were prevailed for cytogenetic investigation based on microscopic observations and cell counting. Microscope slides were prepared following a specific procedure (squash technique and Feulgen method based on modified Carr reactive coloration. Mitotic index as well as chromosomal aberration percentage were calculated for more than 30,000 cells taken into account. From a qualitative viewpoint, chromosomal aberrations such as interchromatidian bridges, lagging and expelled chromosomes and multipolar divisions were evidenced - no distinct situation for either ionizing radiation or electromagnetic field being identified. The main quantitative difference consisted in the increased mitotic index for electromagnetic exposure increased times compared with the diminished mitotic index in the case of low X-ray doses.

  13. Skull x-ray

    Science.gov (United States)

    X-ray - head; X-ray - skull; Skull radiography; Head x-ray ... There is low radiation exposure. X-rays are monitored and regulated to provide the minimum amount of radiation exposure needed to produce the image. Most ...

  14. X-ray diagnostic study on the optimization of digital radiography in dentistry. Optimal exposure conditions for X-ray CCD sensor

    International Nuclear Information System (INIS)

    Hakata, Toshifumi

    2002-01-01

    The purpose of this research is to reduce the patient dose by optimization of irradiation conditions of an X-ray CCD sensor in intra-oral digital radiography. The X-ray diagnosis was divided into two, high quality-of-image diagnosis and low quality-of-image diagnosis, and it optimized by using the exposure of necessary minimum for each. The image quality of CCD was evaluated using the signal-to-noise ratio (SNR) in order to estimate the influence of irradiation conditions. The dose based on CCD maker setting value was set up so that the highest quality of image might be obtained mostly. In low quality-of-image diagnosis, even if it reduced the dose to 13.2% of standard irradiation, SNR was 40% and interpretation was possible. In high quality-of-image diagnosis, even if it reduces the dose to 49% of standard irradiation, SNR remained 80% and there were few differences of the image with a standard. A study of the digital X-ray examination taken at the dental clinic showed high quality-of-image diagnosis was 69% and low quality-of-image one was 31%. When this optimization was performed, it was presumed that reduction of about 62% of the dose is possible. (author)

  15. Evaluation of medical exposure and exposure by the public in a typical scenario of examinations using mobile X-ray equipment through the Monte Carlo simulation

    International Nuclear Information System (INIS)

    Santos, Felipe A.; Galeano, Diego C.; Santos, William S.; Carvalho Júnior, Albérico B.

    2016-01-01

    In this work irradiation scenarios that simulated chest and abdomen examinations involving mobile X-ray equipment in hospitals were modeled with the purpose of calculating conversion coefficient for effective dose (CC E ), normalized to entrance surface dose (ESD), applied to patients and public individuals. These coefficients can easily be used in this practice. Patients and public individuals were represented by a pair of anthropomorphic phantoms inserted in the MCNPX 2.7.0 radiation transport code. One of the phantoms (patient) was irradiated with the direct beam simulating examinations of the chest and abdomen, each with two fields of irradiation, ideal (IF) and extrapolated (EF). Using the software SPECGEN X-ray spectra from 60 to 100 kVp at 10 kVp intervals were generated and used in this work. The other phantom (public individual) was positioned 50–200 cm from the patient. In relation to the CC E calculated in the patient, the average increase obtained between the irradiation fields was 62.4% for the chest examinations, and for the same conditions the CC E was calculated for abdomen examinations and found to be 8.0%. Increasing the distance between public individual and patient, reductions of up to 81.7% in the CC E in abdomen examinations and 83.4% in chest examinations were observed. Through the assessment of CC E of these scenarios, it is possible to measure the damages relating to this practice for both patients and public individuals. - Highlights: • A computational scenario involving mobile X-ray equipment in hospitals were modeled. • Evaluation of medical exposure and exposure by the public was made by CC E (E/ESD). • A pair of the anthropomorphic simulators was inserted into the input file MCNPX. • Analyze the influence in CC E for the different types of fields used in examinations. • Monitoring the reduction of CC E 's with increasing distance between the beds.

  16. Exposure of juvenile Danio rerio to aged TiO₂ nanomaterial from sunscreen.

    Science.gov (United States)

    Fouqueray, Manuela; Noury, Patrice; Dherret, Lysiane; Chaurand, Perrine; Abbaci, Khedidja; Labille, Jerome; Rose, Jerome; Garric, Jeanne

    2013-05-01

    The toxicity of dietary exposure to artificially aged TiO₂ nanomaterial (T-Lite) used in sunscreen cream was studied on Danio rerio. Embryolarval assays were conducted to assess the effects of TiO₂ residues of nanomaterial (RNM) on fish early life stages. Juvenile fishes were exposed by the trophic route in two experiments. During the first experiment, juvenile fishes were exposed to TiO₂ RNM for 14 days by adding RNM to commercial fish food. The second one consisted in producing a trophic food chain. Pseudokirchneriella subcapitata algae, previously contaminated with TiO₂ RNM in growth medium, was used to feed Daphnia magna neonates over a 48-h period. Daphnia were used next to feed juvenile fishes for 7 days. Accumulation of Ti, life traits (survival and growth) and biochemical parameters such as energy reserves, digestive (trypsin, esterase, cellulose and amylase) and antioxidant (superoxide dismutase and catalase) enzyme activity were measured at the end of exposures. As expected in the receiving aquatic system, TiO2 RNM at low concentrations caused a low impact on juvenile zebrafish. A slight impact on the early life stage of zebrafish with premature hatching was observed, and this effect appeared mainly indirect, due to possible embryo hypoxia. When juvenile fish are exposed to contaminated food, digestive enzyme activity indicated a negative effect of TiO₂ RNM. Digestive physiology was altered after 14 days of exposure and seemed to be an indirect target of TiO₂ RNM when provided by food.

  17. Trends in x-ray photography and patient exposure dose. Questionnaire survey results compared with those in 1973. [questionnaire survey in 1979

    Energy Technology Data Exchange (ETDEWEB)

    Orito, T; Sanada, S; Maekawa, R; Koshida, K; Hiraki, T [Kanazawa Univ. (Japan). School of Paramedicine

    1980-04-01

    The exposure doses of patients in X-ray photography are influenced by such technological factors as X-ray tube voltage, filter, sensitizing screen, film and grid. Survey by questionnnaire was made previously in 1973 on the above factors. The trends five years after were surveyed similarly, in connection with the exposure doses of patients. Questionnaires were sent to 200 radiation technicians, and 121 (60.5%) answered the survey in March, 1979. The results in the cases of simple X-ray photography and obstetric, infant and breast X-ray photographings are described. X-ray tube voltage is generally on the increase. In the sensitizing screens, exposure doses are fairly decreased due to the use of improved intensifying screen (LT-II). In the grid, the ratio 8 : 1 is used more than 5 : 1. In the usage of additional filters and in the distance of photography, improvements are desired.

  18. The Evaluation of Conventional X-ray Exposure Parameters Including Tube Voltage and Exposure Time in Private and Governmental Hospitals of Lorestan Province, Iran

    Directory of Open Access Journals (Sweden)

    Mehrdad Gholami

    2015-07-01

    Full Text Available Introduction In radiography, dose and image quality are dependent on radiographic parameters. The problem is caused from incorrect use of radiography equipment and from the radiation exposure to patients much more than required. Therefore, the aim of this study was to implement a quality-control program to detect changes in exposure parameters, which may affect diagnosis or patient radiation dose. Materials and Methods This cross-sectional study was performed on seven stationary X-ray units in sixhospitals of Lorestan province. The measurements were performed, using a factory-calibrated Barracuda dosimeter (model: SE-43137. Results According to the results, the highest output was obtained in A Hospital (M1 device, ranging from 107×10-3 to 147×10-3 mGy/mAs. The evaluation of tube voltage accuracy showed a deviation from the standard value, which ranged between 0.81% (M1 device and 17.94% (M2 device at A Hospital. The deviation ranges at other hospitals were as follows: 0.30-27.52% in B Hospital (the highest in this study, 8.11-20.34% in C Hospital, 1.68-2.58% in D Hospital, 0.90-2.42% in E Hospital and 0.10-1.63% in F Hospital. The evaluation of exposure time accuracy showed that E, C, D and A (M2 device hospitals complied with the requirements (allowing a deviation of ±5%, whereas A (M1 device, F and B hospitals exceeded the permitted limit. Conclusion The results of this study showed that old X-ray equipments with poor or no maintenance are probably the main sources of reducing radiographic image quality and increasing patient radiation dose.

  19. Gender- and Age-Specific Relationships Between Phthalate Exposures and Obesity in Shanghai Adults.

    Science.gov (United States)

    Dong, Ruihua; Zhou, Tong; Chen, Jingsi; Zhang, Meiru; Zhang, Han; Wu, Min; Li, Shuguang; Zhang, Liwen; Chen, Bo

    2017-10-01

    Phthalate exposure has been reported to be associated with obesity (measured by body mass index [BMI]) and central obesity (measured by waist circumference [WC]). Yet, reported associations and the potential gender and age differences are inconsistent. We conducted a cross-sectional study involving 2330 participants in the fall of 2012. Urinary metabolites of ten phthalates were measured. Height, body weight, and waist circumference (WC) were measured using standardized methods. We performed logistic regression analyses to estimate the association between each urine phthalate metabolite (categorized into quartiles) and obesity and central obesity and conducted an additional, stratified analysis to explore the gender and age differences. In the overall study population, higher urinary levels of MMP, MEHHP, and MECPP were associated with increased ratios of central obesity. When stratifying by gender and central obesity, higher urinary levels of MMP, MEHHP, and MEOHP were associated with increased odds of central obesity in females, whereas MB z P was significantly associated inversely with central obesity in females. In males, it showed no significant P value for trend (P trend). When stratifying by age in females, higher urinary levels of MEHP, MEOHP, MEHHP, and MECPP were associated with increased odds of central obesity in women aged ≤45 years. In females aged >45 years, it showed no significant P trend. In conclusion, we found that association between phthalates and central obesity was stronger than between phthalates and obesity; association between phthalates and central obesity was stronger in females than in males and was stronger in younger females (aged ≤45 years) than in older females (aged >45 years).

  20. Technical study on reduction of patient exposure in x-ray examination

    International Nuclear Information System (INIS)

    Ohtsuka, Akiyoshi

    1983-01-01

    This paper deals with the necessity, problems and technical factors on the reduction of the patient exposure, as well as the source of disagreement between doctors and radiologic technologists with respect to their psychological evaluation of the radiological image quality. (1) The patient exposure has a close relationship to the radiological image quality and is affected by many physical and psychological factors. (2) From the patient's point of view, reduction of the patient exposure without the decrease of the image quality has the same meaning as improving the image quality without the increase of the patient exposure. (3) It is known that, in the observation of the radiological image, the radiologic technologists basically attach more importance to the physical evaluation while doctors attach more importance to the psychological evaluation. (4) If doctors and radiologic technologists have more knowledge concerning the radiological imaging technology, optimization of radiographic technique, reduction of the patient exposure and improvement of the diagnostic accuracy can be expected. (author)

  1. Different gene expression of Normal lymphobloastoid cells which exposure to different dose of 60Co γ-ray

    International Nuclear Information System (INIS)

    Xiao Yao; Yang Jian; Gao Xian; Qin Yanghua; Sun Ding; Hai Ling

    2008-01-01

    Objective: To study on the gene expression of normal lymphoblastoid cells(AHH-1) which exposure to difference dose of 60 Co γ-ray, analyses the essential different biological effect.. Methods Human AHH-1 normal line was irradiated by 60 Co γ-rays. Used human cDNA microarray to develop the transcriptional levels of the genes by hybridizing the mRNA of cells 8 h after exposured in different dose and the control cells. Cluster analysis, discrimination and bolting were used to filter the effective genes of differential expression. Results The results of data analysis showed 23 genes of differential expression closely related to biological effect of 2.0 Gy radiation, 5 genes express changed only by 0.5 Gy radiation, 5 genes express apparently both in 2.0 Gy and 0.5 Gy radiation. Conclusion: The different dose γ-rays radiation-induced significant changes in gene expression, such as PAPLN, TP53INP1, PTENP1, FOS and TPR seem to be some important components of cellular radioresponse. (authors)

  2. On micro- and macrocirculatory effects of the whole body exposure to γ-rays in the rabbit

    International Nuclear Information System (INIS)

    Asano, Makishige; Ohkubo, Chiyoji; Chiba, Masashi

    1988-01-01

    Immediate and prolonged microcirculatory effects of varying single doses of the whole body exposure of γ-rays irradiation were studied by using the intravital-microscopy concurrently with macrocirculatory hematological determination in the healthy male rabbit. The intravital-microscopy applied to the subcutaneous microcirculatory system in a transparent round-table chamber, that has been installed in advance into the ear lobe, revealed that markedly increased intravascular adhesiveness of white blood cells (WBCs) and extensive stasis similar to the intravascular coagulation of red blood cells (RBCs) developed as immediate changes soon after the γ-rays irradiation regardless of difference of exposure doses such as 50, 250, 500 and 1000 R. Although these changes disappeared within 3 - 4 weeks in animals exposed to 50 R, they persisted throughout the whole experimental period of 4 weeks at higher doses of γ-rays and the extent of the persisting changes appeared to be dose-dependent. Similarly the macrocirculatory changes such as decreases in measurements of RBCs, WBCs, hematocrit values, hemoglobin concentrations, and platelet counts and increase in erythrocyte sedimentation rates were also noticed in a dose-dependent manner. (author)

  3. Effect of Mitochondrial Oxidative Stress and Age on the Signaling Pathway of Ultrafine Particulate Matter Exposure in Murine Aorta

    Science.gov (United States)

    Epidemiological studies have linked ultrafine particulate matter (PM) exposure and adverse cardiovascular events. PM-induced oxidative stress is believed to be a key mechanism contributing to the adverse short-term vascular effects of air pollution exposure. Advanced age is one ...

  4. Association of Prenatal Ibuprofen Exposure with Birth Weight and Gestational Age: A Population-Based Sibling Study.

    Science.gov (United States)

    Nezvalová-Henriksen, Kateřina; Wood, Mollie; Spigset, Olav; Nordeng, Hedvig

    2016-01-01

    Three studies so far have investigated the effect of prenatal non-steroidal anti-inflammatory drug (NSAID) exposure on birth weight and gestational age. The aim in this study was to evaluate the association of prenatal ibuprofen with birth weight and gestational age at birth, using a sibling design in an attempt to adjust for the possibility of familial confounding. Using data from the Norwegian Mother and Child Cohort Study (MoBa) and the Medical Birth Registry of Norway (MBRN), we identified 28 597 siblings, of whom 1080 were prenatally exposed to ibuprofen and 26 824 were not exposed to any NSAID. Random and fixed effects models with propensity score adjustment were used to evaluate the effects of ibuprofen exposure on birth weight and gestational age. Ibuprofen exposure during the first trimester was associated with a decrease in birth weight of 79 grams (95% confidence interval -133 to -25 grams). In contrast, second and/or third trimester exposure, and duration of exposure had no impact on the effect estimates. We found no association between ibuprofen exposure and gestational age at birth. Our results suggest that prenatal exposure to ibuprofen during the first trimester is associated with a slight decrease in birth weight. The association does not seem to be attributable to shared genetics and family environment, and could be explained by either exposure to ibuprofen, or to non-shared confounding between pregnancies.

  5. Measurements and analyses of cosmic-ray exposure rates perturbed by various environmental objects

    International Nuclear Information System (INIS)

    Fukaya, Mitsuharu; Minato, Susumu

    1988-01-01

    One-dimensional intensity distributions of cosmic-rays transmitted through various large structural objects were measured to examine the feasibility of 'cosmic-ray radiography'. 1) For the rectungular building, (a) the bulk density estimation by comparison of the observed distribution with the calculated one, and (b) edge detection by differential method, were found to be possible. 2) For the stairs in the subway station, the relation between the intensities and the stairs depths was able to be interpreted by a simple model. These findings indicate that it is possible to correlate transmitted cosmic-ray intensity distributions to the structure and/or the physical quantities of large structural objects. (author)

  6. Prenatal Exposure to Organohalogens, Including Brominated Flame Retardants, Influences Motor, Cognitive, and Behavioral Performance at School Age

    NARCIS (Netherlands)

    Roze, Elise; Meijer, Lisethe; Bakker, Attie; Van Braeckel, Koenraad N. J. A.; Sauer, Pieter J. J.; Bos, Arend F.

    2009-01-01

    BACKGROUND: Organohalogen compounds (OHCs) are known to have neurotoxic effects on the developing brain. OBJECTIVE: We investigated the influence of prenatal exposure to OHCs, including brominated flame retardants, on motor, cognitive, and behavioral outcome in healthy children of school age.

  7. Toxicity and Metabolites of 2,4,6- Trinitrotoluene (TNT) in Plants and Worms from Exposure to Aged Soil

    National Research Council Canada - National Science Library

    Best, Elly

    2004-01-01

    .... Short-term exposure tests were conducted to explore the acute toxicity for the test organisms of TNT-spiked artificial soils and of the aged TNT-contaminated soil to be included in the subsequent...

  8. Cosmic ray exposure dating of geo-morphic surface features using in situ-produced 10Be: tectonic and climatic implications

    International Nuclear Information System (INIS)

    Siame, L.; Bellier, O.; Sebrier, M.; Braucher, R.; Bourles, D.L.

    2001-01-01

    The evolution of continental landforms is mainly modulated by the impact of climatic and tectonic processes. Because of their distinctive morphology and the periodicity of their deposition, climatically induced landforms such as alluvial fans or terraces are well suited to infer rates of tectonic and continental climatic processes. Within tectonically active regions, an important step consists in dating displaced geomorphic features to calculate slip rates on active faults. Dating is probably the most critical tool because it is generally much more simpler to measure deformation resulting from tectonic activity than it is to accurately date when that deformation occurred. Recent advances in analytical chemistry and nuclear physics (accelerator mass spectrometry) now allow quantitative abundance measurements of the extremely rare isotopes produced by the interaction of cosmic rays with surface rocks and soils, the so-called in situ-produced cosmogenic nuclides ( 3 He, 10 Be, 21 Ne, 26 Al, 36 Cl), and allow to directly date the duration that a landform has been exposed to cosmic rays at the Earth's surface (Lal, 1991; Nishiizumi et al., 1993; Cerling and Craig, 1994; Clark et al., 1995]. In fact, the abundance of these cosmo-nuclides is proportional to landscape stability and, under favorable circumstances, their abundance within surface rocks can be used as a proxy for erosion rate or exposure age. These cosmo-nuclides thus provide geomorphologists with the opportunity to constrain rates of landscape evolution. This paper presents a new approach that combines cosmic ray exposure (CRE) dating using in situ-produced 10 Be and geomorphic as well as structural analyse. This approach has been applied on two active strike-slip and reverse faults located in the Andean fore-land of western Argentina. These two case studies illustrate how CRE dating using in situ-produced 10 Be is particularly well suited for geomorphic studies that aim to estimate the respective control of

  9. Study of optimal X-ray exposure conditions in consideration of bone mineral density. Relation between bone mineral density and image contrast

    International Nuclear Information System (INIS)

    Kondo, Yuji

    2003-01-01

    Bone mineral density (BMD) increases through infancy and adolescence, reaching a maximum at 20-30 years of age. Thereafter, BMD gradually decreases with age in both sexes. The image contrast of radiographs of bones varies with the change in BMD owing to the changes in the X-ray absorption of bone. The image contrast of bone generally is higher in the young adult than in the older adult. To examine the relation between BMD and image visibility, we carried out the following experiments. We measured the image contrast of radiographs of a lumbar vertebra phantom in which BMD was equivalent to the average BMD for each developmental period. We examined image visibility at various levels of imaging contrast using the Howlett chart. The results indicated that differences in BMD affect the image contrast of radiographs, and, consequently, image visibility. It was also found that image visibility in the young adult was higher than that in the older adult. The findings showed that, in digital radiography of young adults with high BMD, X-ray exposure can be decreased according the ratio of improvement in image visibility. (author)

  10. The morphofunctional state of Purkin'e cells in the cerebellum of new-born rats following laser and gamma-ray exposure

    International Nuclear Information System (INIS)

    Zubkova, S.M.; Popov, V.I.

    1993-01-01

    Following of local laser (632.8 nm, 6.3. J/cm 2 ) and whole-body Gy gamma-ray exposures of new-born rats the contrast changes of morphometrical indices, RNA amount, and chromatophilia of Purkin'e cells in the cerebellum were seen. The preliminary laser exposure of new-born rat cerebellum artially increased activity of karyogene structures of the cerebellum cells which were inhibited by 6.37 Gy gamma-rays

  11. X-Ray diffraction application in studying the nitrogen fixing and aging in stainless steel AISI 304

    International Nuclear Information System (INIS)

    Ramos, L.F.V.

    1973-01-01

    Solid solutions of N in AISI-304 stainless steels were aged to different degrees. The aging was monitored through X-Ray difraction measurement of the lattice parameter 'a'. The increases in 'a', due to the increase of N in solid solution were determined experimentally

  12. Measurement of brain atrophy of aging using x-ray computed tomography

    International Nuclear Information System (INIS)

    Takeda, Shumpei; Matsuzawa, Taiju

    1984-01-01

    We measured brain volume of 1,045 subjects with no brain damage using x-ray computed tomography and investigated brain atrophy of aging. Severity of brain atrophy was estimated by brain atrophy index (BAI): BAI (%)=100 (%)x(cerebrospinal fluid space volume/cranial cavity volume). Atrophy of the brain began with statistical significance in the forties in both sexes. In males 40-49 years of age the mean BAI was 1.0% greater (p<0.001) and the S.D. of BAI was 1.1% greater (p<0.001) than those in their thirties. In females of 40-49 years the mean BAI was 0.5% greater (p<0.001) than that in their thirties, but there was no statistical significance between the two S.D.'s of both decades. The BAI increased exponentially with the increasing age from thirties in both sexes. Correlation coefficients were 0.702 (p< 0.001, n=471) in males and 0.721 (p<0.001, n=480) in females. From the regression coefficients it was calculated that the BAI was doubled in 19.4 years in males and 17.4 years in females after thirties. (author)

  13. Assessing dietary exposure to cadmium in a metal recycling community in Vietnam: Age and gender aspects

    International Nuclear Information System (INIS)

    Minh, Ngo Duc; Hough, Rupert Lloyd; Thuy, Le Thi; Nyberg, Ylva; Mai, Le Bach; Vinh, Nguyen Cong; Khai, Nguyen Manh; Öborn, Ingrid

    2012-01-01

    This study estimates the dietary exposure to cadmium (Cd), and associated potential health risks, for individuals living and working in a metal recycling community (n = 132) in Vietnam in comparison to an agricultural (reference) community (n = 130). Individual-level exposure to Cd was estimated through analysis of staple foodstuffs combined with information from a food frequency questionnaire. Individual-level exposure estimates were compared with published ‘safe’ doses to derive a Hazard Quotient (HQ) for each member of the study population. Looking at the populations as a whole, there were no significant differences in the diets of the two villages. However, significantly more rice was consumed by working age adults (18–60 years) in the recycling village compared to the reference village (p 3), while 20% of adult participants from the reference village had an HQ > 1. We found an elevated health risk from dietary exposure to Cd in the metal recycling village compared to the reference community. WHO standard of 0.4 mg Cd/kg rice may not be protective where people consume large amounts of rice/have relatively low body weight. - Highlights: ► First individual-level risk assessment of cadmium in recycling villages of Vietnam. ► Dietary analysis undertaken for a recycling community and an agricultural community. ► No significant differences were found between the diets of the two populations. ► 87% of people in the recycling community had elevated health risk. ► WHO standard (0.4 mg Cd/kg rice) may not be protective for rice-based cultures.

  14. Age-dependent tissue-specific exposure of cell phone users

    International Nuclear Information System (INIS)

    Christ, Andreas; Gosselin, Marie-Christine; Kuehn, Sven; Kuster, Niels; Christopoulou, Maria

    2010-01-01

    The peak spatial specific absorption rate (SAR) assessed with the standardized specific anthropometric mannequin head phantom has been shown to yield a conservative exposure estimate for both adults and children using mobile phones. There are, however, questions remaining concerning the impact of age-dependent dielectric tissue properties and age-dependent proportions of the skull, face and ear on the global and local absorption, in particular in the brain tissues. In this study, we compare the absorption in various parts of the cortex for different magnetic resonance imaging-based head phantoms of adults and children exposed to different models of mobile phones. The results show that the locally induced fields in children can be significantly higher (>3 dB) in subregions of the brain (cortex, hippocampus and hypothalamus) and the eye due to the closer proximity of the phone to these tissues. The increase is even larger for bone marrow (>10 dB) as a result of its significantly high conductivity. Tissues such as the pineal gland show no increase since their distances to the phone are not a function of age. This study, however, confirms previous findings saying that there are no age-dependent changes of the peak spatial SAR when averaged over the entire head.

  15. Age-dependent tissue-specific exposure of cell phone users

    Energy Technology Data Exchange (ETDEWEB)

    Christ, Andreas; Gosselin, Marie-Christine; Kuehn, Sven; Kuster, Niels [Foundation for Research on Information Technologies in Society (IT' IS), Zeughausstr. 43, 8004 Zuerich (Switzerland); Christopoulou, Maria [National Technical University of Athens, School of Electrical and Computer Engineering, 9 Iroon Polytechniou Str., 15780 Athens (Greece)], E-mail: christ@itis.ethz.ch

    2010-04-07

    The peak spatial specific absorption rate (SAR) assessed with the standardized specific anthropometric mannequin head phantom has been shown to yield a conservative exposure estimate for both adults and children using mobile phones. There are, however, questions remaining concerning the impact of age-dependent dielectric tissue properties and age-dependent proportions of the skull, face and ear on the global and local absorption, in particular in the brain tissues. In this study, we compare the absorption in various parts of the cortex for different magnetic resonance imaging-based head phantoms of adults and children exposed to different models of mobile phones. The results show that the locally induced fields in children can be significantly higher (>3 dB) in subregions of the brain (cortex, hippocampus and hypothalamus) and the eye due to the closer proximity of the phone to these tissues. The increase is even larger for bone marrow (>10 dB) as a result of its significantly high conductivity. Tissues such as the pineal gland show no increase since their distances to the phone are not a function of age. This study, however, confirms previous findings saying that there are no age-dependent changes of the peak spatial SAR when averaged over the entire head.

  16. Species- and age-related variation in metal exposure and accumulation of two passerine bird species

    Energy Technology Data Exchange (ETDEWEB)

    Berglund, A.M.M., E-mail: asa.berglund@emg.umu.se [Section of Ecology, 20014 University of Turku (Finland); Koivula, M.J.; Eeva, T. [Section of Ecology, 20014 University of Turku (Finland)

    2011-10-15

    We measured the concentration of several elements (arsenic [As], calcium [Ca], cadmium [Cd], copper [Cu], nickel [Ni], lead [Pb], selenium [Se] and zinc [Zn]) in adult and nestling pied flycatchers (Ficedula hypoleuca) and great tits (Parus major) at different distances to a Cu-Ni smelter in 2009. Feces of nestlings generally failed to correspond with internal element concentrations but reflected the pollution exposure, indicating an increased stress by removal of excess metals. The uptake of Cu and Ni were regulated, but As, Cd, Pb and Se accumulated in liver tissue. Pied flycatchers had generally higher element concentrations than great tits. The higher accumulation of As and Pb in pied flycatcher livers was explained by a more efficient absorption, whereas the higher Cd concentration was primarily due to different intake of food items. Age-related differences occurred between the two species, though both Cd and Se accumulated with age. - Highlights: > We measured metal concentrations in feces and livers of two passerine species. > We examined species- and age-related differences in polluted environments. > Feces was evaluated as a useful non-destructive measure of increased stress. > Generally pied flycatchers accumulated higher concentrations than great tits. > Cadmium and selenium accumulated with age in both species. - Accumulation of metals in liver of two insectivorous passerines reflects inter-specific differences in diet, absorption rate and physiological requirements.

  17. Species- and age-related variation in metal exposure and accumulation of two passerine bird species

    International Nuclear Information System (INIS)

    Berglund, A.M.M.; Koivula, M.J.; Eeva, T.

    2011-01-01

    We measured the concentration of several elements (arsenic [As], calcium [Ca], cadmium [Cd], copper [Cu], nickel [Ni], lead [Pb], selenium [Se] and zinc [Zn]) in adult and nestling pied flycatchers (Ficedula hypoleuca) and great tits (Parus major) at different distances to a Cu-Ni smelter in 2009. Feces of nestlings generally failed to correspond with internal element concentrations but reflected the pollution exposure, indicating an increased stress by removal of excess metals. The uptake of Cu and Ni were regulated, but As, Cd, Pb and Se accumulated in liver tissue. Pied flycatchers had generally higher element concentrations than great tits. The higher accumulation of As and Pb in pied flycatcher livers was explained by a more efficient absorption, whereas the higher Cd concentration was primarily due to different intake of food items. Age-related differences occurred between the two species, though both Cd and Se accumulated with age. - Highlights: → We measured metal concentrations in feces and livers of two passerine species. → We examined species- and age-related differences in polluted environments. → Feces was evaluated as a useful non-destructive measure of increased stress. → Generally pied flycatchers accumulated higher concentrations than great tits. → Cadmium and selenium accumulated with age in both species. - Accumulation of metals in liver of two insectivorous passerines reflects inter-specific differences in diet, absorption rate and physiological requirements.

  18. Aging

    International Nuclear Information System (INIS)

    Sasaki, Hideo; Kodama, Kazunori; Yamada, Michiko

    1991-01-01

    The hypothesis that exposure to ionizing radiation accelerates the aging process has been actively investigated at ABCC-RERF since 1958, when longitudinal cohort studies of the Adult Health Study (AHS) and the Life Span Study (LSS) were initiated. In their 1975 overall review of aging studies related to the atomic bomb (A-bomb) survivors, Finch and Beebe concluded that while most studies had shown no correlation between aging and radiation exposure, they had not involved the large numbers of subjects required to provide strong evidence for or against the hypothesis. Extending LSS mortality data up to 1978 did not alter the earlier conclusion that any observed life-shortening was associated primarily with cancer induction rather than with any nonspecific cause. The results of aging studies conducted during the intervening 15 years using data from the same populations are reviewed in the present paper. Using clinical, epidemiological, and laboratory techniques, a broad spectrum of aging parameters have been studied, such as postmortem morphological changes, tests of functional capacity, physical tests and measurements, laboratory tests, tissue changes, and morbidity. With respect to the aging process, the overall results have not been consistent and are generally thought to show no relation to radiation exposure. Although some preliminary results suggest a possible radiation-induced increase in atherosclerotic diseases and acceleration of aging in the T-cell-related immune system, further study is necessary to confirm these findings. In the future, applying the latest gerontological study techniques to data collected from subjects exposed 45 years ago to A-bomb radiation at relatively young ages will present a new body of data relevant to the study of late radiation effects. (author) 103 refs

  19. The morphological study of age-dependent effects in rat thyroids after γ-ray irradiation

    International Nuclear Information System (INIS)

    Zhang Xuefeng; Guo Lisheng; Tu Kaicheng; Xian Guoliang; Shi Feiman

    1993-01-01

    The purpose of this paper is to identify the differences in age-related harmful effects of the thyroid gland to ionizing radiation. The infant (0.5 month) and adult rats (2.5,6 and 15 months, respectively) were exposed to single γ-ray neck irradiation (0 Gy, as control, 0.5 Gy, 2 Gy, 4 Gy, 8 Gy, 16 Gy). The structure of irradiated thyroid gland under light and transmission electron microscope were observed at 6 weeks after partial irradiation. Some morphometric parameters were measured under light microscope. The results showed that the infant rat thyroids changed significantly after 0.5 Gy, but the adult thyroids expressed similar response after more than 2 Gy. Analyses of these data and information on pathology suggested that the infant thyroids were more radiosensitive than the adult ones

  20. Elevated manganese exposure and school-aged children's behavior: a gender-stratified analysis.

    Science.gov (United States)

    Menezes-Filho, José A; de Carvalho-Vivas, Chrissie F; Viana, Gustavo F S; Ferreira, Junia R D; Nunes, Lorena S; Mergler, Donna; Abreu, Neander

    2014-12-01

    High levels of waterborne manganese have been associated with problematic behavior in school-aged children, however to date this has not been reported for children exposed to airborne manganese. The objective of the present study was to examine behavioral traits among children with exposure to airborne manganese from a ferro-manganese alloy plant, located in the metropolitan region of Salvador, Brazil. The study included 34 boys and 36 girls, aged 7-12 years, living in two communities within a 3-km radius from the plant. For each child, hair manganese levels (MnH) and blood lead (PbB) levels were analyzed by graphite furnace atomic absorption spectrometry. The Children's Behavior Check List (CBCL) (Portuguese version validated in Brazil) was administered to parents or caregivers, providing scale scores of internalizing (withdrawn, somatic complaints, and anxious/depressed scales), externalizing (disruptive and aggressive) behaviors and a separate scale for attention problems. Median and range for MnH and PbB were 11.48 μg/g (range: 0.52-55.74); 1.1 μg/dL (range: 0.5-6.1), respectively. Spearman correlation analyses showed that several behavioral indices were significantly correlated with MnH levels for girls, but not for boys: total externalizing behavior (rho=0.484 vs rho=0.041) and attention problem scores (rho=0.542 vs rho=0.003) coefficients were significantly at pMnH stratified by sex, adjusting for age and maternal IQ. Total externalizing behaviors and attention problem scores were significantly associated with girls' MnH levels but not with boys'. Adjusting for maternal IQ, the β-coefficients for LogMnH associations with total externalizing and attention problems are 8.85 (95%CI 2.44-15.24) and 4.03 (95%CI 1.50-6.56) for girls. For boys, after adjusting for age, the β-coefficients are 0.08 (95%CI 11.51-11.66) and -0.05 (95%CI 4.34-4.25), respectively. The findings of this study suggest a positive association between elevated Mn exposure and externalizing

  1. Effect of low lead exposure on gestational age, birth weight and premature rupture of the membrane

    International Nuclear Information System (INIS)

    Mirghani, Z.

    2010-01-01

    Objective: To find out the effect of prenatal exposure to low lead from cosmetics on gestational age, premature rupture of the membrane and birth weight. Methods: The study was carried out in the mountainous Aseer region, Southwest of Saudi Arabia where the air is thought to be clean and free of lead pollution due to the absence of petroleum smelting and other heavy industries. The region is famous as a holiday resort for tourists from Arabia and the gulf countries. All 176 pregnant women included in the study were of singleton pregnancies of gestational age 27 weeks or more who attended the antenatal outpatient clinic of the main maternity hospital. On the day of delivery 4 milliliters of venous blood from each singleton parturient was placed in a heparinized non-silica containing tube and stored at -20 deg. C prior to analysis. Results: Ninety-four (70.1%) women out of 134 had maternal blood lead concentration 200 mu g/L. The mean difference in gestational age was 10.5 days, showing a non significant difference (P=0.152). Ninety-three women (72.7%) out of a total of 128 who had blood lead concentration 200 mu g/L gave birth to infants weighing an average of 2.99 kg. The mean difference was 0.12 kg which is non-significant (P=0.261). Regarding premature rupture of the membrane a total of 127 women with maternal blood lead levels above 200 mu g/L showed no significant differences (P=0.64). The Chi-square test of the relationship between the birth weight (kg) and the levels of blood lead below 150 mu g/L was not significant while the relationship between the birth weight (kg) and the levels of blood lead above 200 mu g/L resulted in very slight differences in the values of infants' birth weight. Conclusion: The detected low lead exposures from cosmetics does not produce statistically significant effects on the three pregnancy outcomes; gestational age, premature rupture of the membrane or birth weight. However, the importance of low lead exposure from the 100% lead

  2. Effect of low lead exposure on gestational age, birth weight and premature rupture of the membrane.

    Science.gov (United States)

    Mirghani, Zein

    2010-12-01

    To find out the effect of prenatal exposure to low lead from cosmetics on gestational age, premature rupture of the membrane and birth weight. The study was carried out in the mountainous Aseer region, Southwest of Saudi Arabia where the air is thought to be clean and free of lead pollution due to the absence of petroleum smelting and other heavy industries. The region is famous as a holiday resort for tourists from Arabia and the gulf countries. All 176 pregnant women included in the study were of singleton pregnancies of gestational age 27 weeks or more who attended the antenatal outpatient clinic of the main maternity hospital. On the day of delivery 4 milliliters of venous blood from each singleton parturient was placed in a heparinized non-silica containing tube and stored at -20 degrees C prior to analysis. Ninety-four (70.1%) women out of 134 had maternal blood lead concentration 200 microg/L. The mean difference in gestational age was 10.5 days, showing a non significant difference (P=0.152). Ninety-three women (72.7%) out of a total of 128 who had blood lead concentration 200 microg/L gave birth to infants weighing an average of 2.99 kg. The mean difference was 0.12 kg which is non-significant (P=0.261). Regarding premature.rupture of the membrane a total of 127 women with maternal blood lead levels above 200 microg/L showed no significant differences (P=0.64). The Chi-square test of the relationship between the birth weight (kg) and the levels of blood lead below 150 microg/L was not significant while the relationship between the birth weight (kg) and the levels of blood lead above 200 microg/L resulted in very slight differences in the values of infants' birth weight. The detected low lead exposures from cosmetics does not produce statistically significant effects on the three pregnancy outcomes; gestational age, premature rupture of the membrane or birth weight. However, the importance of low lead exposure from the 100% lead sulfide eye cosmetic "kohl

  3. Bisphenol A exposure and asthma development in school-age children: a longitudinal study.

    Directory of Open Access Journals (Sweden)

    Kyoung-Nam Kim

    Full Text Available Although the effect of bisphenol A on various health outcomes has been extensively examined, few studies have investigated its effect on asthma.We hypothesized that exposure to bisphenol A in school-age children was associated with wheezing and asthma.Participants included 127 children aged 7-8 years without a previous asthma diagnosis in an elementary school in Seoul, Korea. Three surveys were conducted, each 2 years apart. Bisphenol A concentration was measured at the baseline survey, and PC20, which is defined as the methacholine concentration that induces a decrease in FEV1 of 20% from baseline, was measured at every survey. Associations between bisphenol A concentration at 7-8 years of age and wheezing, asthma, and PC20 at ages up to 11-12 years were examined using generalized estimating equations, a marginal Cox regression model, and a linear mixed model.The log-transformed creatinine-adjusted urinary bisphenol A concentration at 7-8 years was positively associated with wheezing (odds ratio, 2.48; 95% confidence interval, 1.15-5.31; P = .02 and asthma (hazard ratio, 2.13; 95% confidence interval, 1.51-3.00; P<.001 at ages up to 11-12 years. Bisphenol A was also negatively associated with PC20 (ß = -2.33; P = .02. When stratified by sex, the association between bisphenol A and asthma remained significant only in girls (hazard ratio, 2.45; 95% confidence interval, 2.18-2.76; P<.001.Increased urinary bisphenol A concentrations at 7-8 years old were positively associated with wheezing and asthma and negatively associated with PC20 at ages up to 11-12 years.

  4. Europium- and lithium-doped yttrium oxide nanocrystals that provide a linear emissive response with X-ray radiation exposure

    Science.gov (United States)

    Stanton, Ian N.; Belley, Matthew D.; Nguyen, Giao; Rodrigues, Anna; Li, Yifan; Kirsch, David G.; Yoshizumi, Terry T.; Therien, Michael J.

    2014-04-01

    Eu- and Li-doped yttrium oxide nanocrystals [Y2-xO3 Eux, Liy], in which Eu and Li dopant ion concentrations were systematically varied, were developed and characterized (TEM, XRD, Raman spectroscopic, UV-excited lifetime, and ICP-AES data) in order to define the most emissive compositions under specific X-ray excitation conditions. These optimized [Y2-xO3 Eux, Liy] compositions display scintillation responses that: (i) correlate linearly with incident radiation exposure at X-ray energies spanning from 40-220 kVp, and (ii) manifest no evidence of scintillation intensity saturation at the highest evaluated radiation exposures [up to 4 Roentgen per second]. For the most emissive nanoscale scintillator composition, [Y1.9O3; Eu0.1, Li0.16], excitation energies of 40, 120, and 220 kVp were chosen to probe the dependence of the integrated emission intensity upon X-ray exposure-rate in energy regimes having different mass-attenuation coefficients and where either the photoelectric or the Compton effect governs the scintillation mechanism. These experiments demonstrate for the first time for that for comparable radiation exposures, when the scintillation mechanism is governed by the photoelectric effect and a comparably larger mass-attenuation coefficient (120 kVp excitation), greater integrated emission intensities are recorded relative to excitation energies where the Compton effect regulates scintillation (220 kVp) in nanoscale [Y2-xO3 Eux] crystals. Nanoscale [Y1.9O3; Eu0.1, Li0.16] (70 +/- 20 nm) was further exploited as a detector material in a prototype fiber-optic radiation sensor. The scintillation intensity from the [Y1.9O3; Eu0.1, Li0.16]-modified, 400 μm sized optical fiber tip, recorded using a CCD-photodetector and integrated over the 605-617 nm wavelength domain, was correlated with radiation exposure using a Precision XRAD 225Cx small-animal image guided radiation therapy (IGRT) system. For both 80 and 225 kVp energies, this radiotransparent device recorded

  5. Ultrastructural changes in spermatogonia of Wistar strain rats following acute whole-body X-ray exposure

    Energy Technology Data Exchange (ETDEWEB)

    Hrehorovsky, M; Horak, J [Univerzita P.J. Safarika, Kosice (Czechoslovakia). Katedra Vseobecnej Biologie

    1980-01-01

    Changes in spermatogonia ultrastructure in rats of Wistar strain after single whole-body X-ray irradiation with 6.4 mC.kg/sup -1/, 25.8 mC.kg/sup -1/ and 51.6 mC.kg/sup -1/ respectively, were studied. Intracellular spaces were found between spermatogonia enlarged, nuclear membranes were bent, the pheripheral teritories of chromation were electronoptically denser, the morphology of nucleoli was changed, cytoplasm was vacuolised, mitochondria were damaged, the vacuolar dilatation of agranular endoplasmic reticulum was evident and electronoptically empty vacuoles near the Golgi complex occured 48 hours after single whole-body X-ray irradiation. Qualitative changes in the ultrastructure of individual types of spermatogonia after individual exposures were similar.

  6. Restoring efficiency of hemopoietic cell transplantation in a mouse lethally irradiated by a total exposure to X rays

    International Nuclear Information System (INIS)

    Doria, Gino

    1959-10-01

    This research thesis reports the study of possibility of treatments (or restoration) of a mouse which has been submitted to a lethal dose of X rays. More particularly, the author compared the restoring efficiency of bone marrow and fetal liver injected in a mouse which had been lethally irradiated by a total exposure to X rays. He also studied the functional status of the hemopoietic graft, and the emergence of the secondary disease in mice which had been as well lethally irradiated and then restored by injection of bone marrow and fetal liver. The author then addressed the influence of the induction of immune tolerance of the host with respect to the donor on the survival of a mouse lethally irradiated and restored by homologue bone marrow [fr

  7. Protocol for X-ray dosimetry and exposure arrangements employed in studies of late somatic effects in mammals

    International Nuclear Information System (INIS)

    Zoetelief, J.; Kogel, A.J. van der; Broerse, J.J.; Scarpa, G.; Dixon-Brown, A.

    1985-01-01

    A number of European laboratories studying the late effects of ionizing radiation in animals have established an effective cooperation within the European Late Effects Project Group (EULEP) since 1970. To facilitate the exchange of biological results several techniques, including quality control of the experimental animals, pathology and dosimetry, have to be standardized. The most important aspects of the procedures for X-irradiation and dosimetry of small animals are summarized. These include recommendations on irradiation conditions, dosimetry methods, characteristics of phantoms and factors affecting X-ray dosimetry. X-irradiation procedures employed by the participating institutes are described and the results of five X-ray dosimetry intercomparisons are reported. The introduction of a common dosimetry protocol has resulted in improvements in exposure arrangements and absolute dosimetry. (author)

  8. Development of a head simulator for exposure dose estimation on patients exposed by odontological X-rays

    International Nuclear Information System (INIS)

    Moura Neto, Francisco N.; Batista, Eutropio V.; Santos, Adriano M.

    2009-01-01

    In the obtaining a odontological radiography, the individual is exposed to te radiation and part of that radiation will be absorbed by his organism. The estimative of absorbed dose can be accomplished through calculations where are considered: the distance from the source to the individual, the energy of the emitted X-ray at the moment of the exposure and the bode region exposed; and as that option does not possess great precision, alternative forms are seek for the quantification such doses. This work proposes the construction of a head simulator to be used in the estimative of absorbed dose in patients, during the accomplishment of the odontological radiographic examinations. As a perspective of work, it is intended to use the phantom to help in the absorbed doses for obtainment of parameters in X-ray odontological devices, contributing of image obtainment with more quality and less radiation dose in the patient

  9. SU-E-I-52: Effect of Various X-Ray Beam Qualities On the Exposure Index

    International Nuclear Information System (INIS)

    Yasumatsu, S; Iwase, K; Shimizu, Y; Tanaka, N; Morishita, J

    2015-01-01

    Purpose: The exposure index (EI) proposed by the International Electrotechnical Commission (IEC) 62494-1 is expected to be utilized as a standard dose index by every manufacturer. The IEC recommended the usage of RQA5 for the EI. However, X-ray beam qualities, particularly in clinical practices, vary depending on the examination objects and exposure conditions, including usage of anti-scatter grids. We investigated the effects of the X-ray beam qualities other than RQA5 on the EI. Methods: The Xray beam qualities of RQA3, 5, 7, and 9 in IEC 61267 Ed. 1.0 were adopted in a computed radiography system. A uniform exposure without objects was performed to measure the exposure indicators (S values) and air kerma (K). The relational equations between the S values and K were derived for the determination of the EI values. The EI values for RQA3, 7, and 9 were compared to those for RQA5 at the fixed S values of 100, 200, 400, and 600. Finally, the half-value layers (HVLs) using four grids (ratio 6:1, 8:1, 10:1, and 12:1) for the RQA5 X-ray were compared to those with RQA3–9. Results: The EI values for RQA3, 7, and 9 were up to 35.3%, 11.8%, and 38.7% higher, respectively, than that for RQA5 at the S value of 600. The HVLs without grids and with various grids for RQA5 were 6.85 mm Al. and in the range of 6.94–7.29 mm Al. (ΔHVL: up to 0.44 mm Al.), respectively. This variation in the HVLs with grids was smaller than that observed for RQA3–9 (ΔHVL: 2.0–7.5 mm Al.). Conclusion: Although the usage of grids may not greatly affect the EI, the X-ray beam quality for the determination of the EI cannot be ignored in the clinical evaluation of the dose index

  10. X-ray equipment for dental diagnostics with a dose-rate controller influencing the exposure voltage

    International Nuclear Information System (INIS)

    Franke, K.

    1980-01-01

    If a synoptic picture is taken of teeth or jaw the X-ray tube and the film carrier with the film and a radiation detector are moving around the patient's head. The detector signal is connected to the input of the actual value of the dose-rate controller containing a scanning and stop circuit with a storing time roughly corresponding to the exposure of three teeth. After the shot the actual value of the dose rate is adjusted to the desired value, thus a constant quality of the following pictures being achieved. (RW) [de

  11. Effective energies and exposure determinations of two different energy X-ray beams incident on a personnel monitor

    International Nuclear Information System (INIS)

    Okuno, E.; Cruz, M.T. da

    1984-01-01

    The effective energy of one X or gamma ray beam can be determined by means of two thermoluminescent (TL) dosemeters mounted between suitable filters. However, it has been observed that personnel monitors exposed to two different energy ionizing radiations provide different effective energies depeding on the type of TL phosphor used. This fact could be a powerful tool for identifying exposures to radiation with quite different effective energies which are very common in practice. Two types of TL dosemeters were used : pellets of cold pressed natural fluoride and NaCl developed in our own laboratory, and LiF, TLD-100 from Harshaw Chemical Co.. Experimental results obtained with these combined dosemeters after irradiation with different sets of exposures and energy values of ionizing radiations are also presented. (Author) [pt

  12. Effect of in utero exposure to diagnostic doses of X-rays on the growth and behaviour of mouse

    International Nuclear Information System (INIS)

    Prakash Hande, M.; Uma Devi, P.

    1992-01-01

    Intrauterine development, particularly the period of organogenesis is an especially radiosensitive phase in mammals. Teratogenic effect of low dose irradiation has been demonstrated in laboratory animals. Several studies have indicated the vulnerability of the developing human brain to radiation injury and demonstrated changes in postnatal behaviour following intrauterine animal irradiation. However, data are lacking on the comparative response of the different stages of prenatal development to low doses at levels that could result from diagnostic radiation exposure. This study attempts to empirically evaluate the differential response of critical stages in prenatal development of mouse to single low dose exposures to diagnostic X-rays. Data on growth and behaviour are briefly presented. (author). 22 refs., 2 figs., 1 tab

  13. Measurement of the exposure rate due to low energy x-rays emitted from video display terminals

    International Nuclear Information System (INIS)

    Campos, L.L.

    1988-01-01

    Thermoluminescent dosimeters of CaSO 4 :Dy have been used to measure the low energy x-rays emitted from Video Display Terminals (VDTs). For each terminal, three points were measured with five dosimeters at each point. The points were at distances of 5 and 50 cm in front of the screen and at 65 cm with an angle of approximately 50 0 . The last two positions approximate to positions of the lenses of the eye and the gonads respectively. A survey of 50 VDTs at a distance of 5 cm from the screen resulted in exposure rates nearly fifteen times below the exposure rate of 0.5 mR h -1 (0.129 μC kg -1 h -1 ) which is the limit recommended by the International Atomic Energy Agency (IAEA), Safety Series No. 9 (1967) Basic Safety Standards for Radiation Protection. (author)

  14. Exposure to ionizing radiation during dental X-rays is not associated with risk of developing meningioma: a meta-analysis based on seven case-control studies.

    Science.gov (United States)

    Xu, Ping; Luo, Hong; Huang, Guang-Lei; Yin, Xin-Hai; Luo, Si-Yang; Song, Ju-Kun

    2015-01-01

    Many observational studies have found that exposure to dental X-rays is associated with the risk of development of meningioma. However, these findings are inconsistent. We conducted a meta-analysis to assess the relationship between exposure to dental X-rays and the risk of development of meningioma. The PubMed and EMBASE databases were searched to identify eligible studies. Summary odds ratio (OR) estimates and 95% confidence intervals (95% CIs) were used to compute the risk of meningioma development according to heterogeneity. Subgroup and sensitivity analyses were performed to further explore the potential heterogeneity. Finally, publication bias was assessed. Seven case-control studies involving 6,174 patients and 19,459 controls were included in the meta-analysis. Neither exposure to dental X-rays nor performance of full-mouth panorex X-rays was associated with an increased risk of development of meningioma (overall: OR, 0.97; 95% CI, 0.70-1.32; dental X-rays: OR, 1.05; 95% CI, 0.89-1.25; panorex X-rays: OR, 1.01; 95% CI, 0.76-1.34). However, exposure to bitewing X-rays was associated with a slightly increased risk of development of meningioma (OR, 1.73; 95% CI, 1.28-2.34). Similar results were obtained in the subgroup and sensitivity analyses. Little evidence of publication bias was observed. Based on the currently limited data, there is no association between exposure to dental X-rays and the risk of development of meningioma. However, these results should be cautiously interpreted because of the heterogeneity among studies. Additional large, high-quality clinical trials are needed to evaluate the association between exposure to dental X-rays and the risk of development of meningioma.

  15. Exposure to ionizing radiation during dental X-rays is not associated with risk of developing meningioma: a meta-analysis based on seven case-control studies.

    Directory of Open Access Journals (Sweden)

    Ping Xu

    Full Text Available Many observational studies have found that exposure to dental X-rays is associated with the risk of development of meningioma. However, these findings are inconsistent. We conducted a meta-analysis to assess the relationship between exposure to dental X-rays and the risk of development of meningioma.The PubMed and EMBASE databases were searched to identify eligible studies. Summary odds ratio (OR estimates and 95% confidence intervals (95% CIs were used to compute the risk of meningioma development according to heterogeneity. Subgroup and sensitivity analyses were performed to further explore the potential heterogeneity. Finally, publication bias was assessed.Seven case-control studies involving 6,174 patients and 19,459 controls were included in the meta-analysis. Neither exposure to dental X-rays nor performance of full-mouth panorex X-rays was associated with an increased risk of development of meningioma (overall: OR, 0.97; 95% CI, 0.70-1.32; dental X-rays: OR, 1.05; 95% CI, 0.89-1.25; panorex X-rays: OR, 1.01; 95% CI, 0.76-1.34. However, exposure to bitewing X-rays was associated with a slightly increased risk of development of meningioma (OR, 1.73; 95% CI, 1.28-2.34. Similar results were obtained in the subgroup and sensitivity analyses. Little evidence of publication bias was observed.Based on the currently limited data, there is no association between exposure to dental X-rays and the risk of development of meningioma. However, these results should be cautiously interpreted because of the heterogeneity among studies. Additional large, high-quality clinical trials are needed to evaluate the association between exposure to dental X-rays and the risk of development of meningioma.

  16. γ-ray induced chromosome aberration in rabbit peripheral blood lymphocytes irradiated in partial and whole body and decline of aberration rate with time post-exposure

    International Nuclear Information System (INIS)

    Zhang Lianzhen; Deng Zhicheng; Wang Haiyan

    1997-01-01

    Te author presents the results of study on 60 Co γ-ray induced chromosome aberration in rabbits peripheral blood lymphocytes irradiated in partial and whole body and the aberration rate decrease with the time of post-exposure. The experiments included 5 groups, it was whole-body exposure group, partial-body exposure (abdomen and pelvic cavity) group, blood irradiation group in vitro and control group respectively. Radiation dose was 3.0 Gy delivered at rate of 0.5 Gy/min. The results show that it was no significant differences between whole body and in blood irradiation group. The chromosome aberration yield in whole body exposure group was higher than that in partial-body group and in the abdomen exposure group was higher than in that in the pelvic cavity irradiation; The chromosome aberration rate decreased with the time of post-exposure in partial and whole body by γ-ray irradiation

  17. Ultrasensitive Determination of 81Kr-Kr Cosmic Ray Exposure Ages of Eucrites and Bunburra Rockhole

    Czech Academy of Sciences Publication Activity Database

    Strashnov, I.; Bland, P.A.; Spurný, Pavel; Towner, M.C.; Gilmour, D.J.

    2011-01-01

    Roč. 46, Supplement (2011), A226-A226 ISSN 1086-9379. [Annual Meeting of the Meteoritical Society /74./. 08.08.2011-12.08.2011, London] Institutional research plan: CEZ:AV0Z10030501 Keywords : Bunburra Rockhole Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics

  18. Light Noble Gases and a Cosmic Ray Exposure Age for the Bunburra Rockhole Meteorite

    Czech Academy of Sciences Publication Activity Database

    Meier, M.M.M.; Bland, P.A.; Welten, K.C.; Spurný, Pavel; Baur, H.; Wieler, R.

    2009-01-01

    Roč. 44, Supplement (2009), A138-A138 ISSN 1086-9379. [Annual Meeting of the Meteoritical Society /72./. Nancy, 13.06.2009-18.06.2009] Institutional research plan: CEZ:AV0Z10030501 Keywords : Bunburra Rockhole * light noble gas * concentration Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics Impact factor: 3.253, year: 2009

  19. Cosmic-ray exposure age and preatmospheric size of the Bunburra Rockhole achondrite

    Czech Academy of Sciences Publication Activity Database

    Welten, K.C.; Meier, M.M.M.; Caffee, M. W.; Laubenstein, M.; Nishizumi, K.; Wieler, R.; Bland, P.A.; Towner, M.C.; Spurný, Pavel

    2012-01-01

    Roč. 47, č. 2 (2012), s. 186-196 ISSN 1086-9379 Institutional research plan: CEZ:AV0Z10030501 Keywords : Bunburra Rockhole * achondrites * parent bodies. Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics Impact factor: 2.800, year: 2012

  20. Influence of turmeric on biochemical disorders induced by exposure to gamma- rays or chloropyrifos pesticide on rats

    International Nuclear Information System (INIS)

    Kamal El-Dein, E.M.; Ebrahim, R.M.

    2013-01-01

    Toxicity of Chloropyrifos and gamma-radiation exposure on rats were examined in the presence or absence of Turmeric (200 mg/ kg/ b.wt.). Effects chloropyrifos when administrated orally to rats at a dose 9 mg/ kg b .wt (1/ 4 LD 50) for 7 and 28 days showed increased level of malondialdehyde (MDA) concomitant with depletion in the levels of glutathion (GSH), superoxide dismutase (SOD) and catalase (CAT).gamma- radiation exposure effect on rats was examined in the presence or absence of turmeric . Exposure of rats to gamma-radiation (8 Gy) at a fractionated dose levels (2 Gy/ week for 4 weeks) exhibited an elevated level of MDA and decreased level of GSH, SOD and CAT. Administration of Turmeric to animals which were previously treated with Chloropyrifos or gamma-rays showed an amelioration response to the antioxidant regime. Treatment of rats with Chloropyrifos for 7 and 28 days or gamma- radiation induced an elevated serum transaminases level(ALT and AST),Alkaline phosphatase (ALP) and Acid phosphatase activity (ACP), creatinine concentration, blood urea and uric acid.Also treatment of rats with Chloropyrifos for 7 and 28 days or gamma-radiation induced a decline in the testosterone level associated with alteration in the levels of follicular stimulating hormone (FSH),Iuetinizing hormone (LH) and prolactin (PRL).Results observed due to Chloropyrifos pesticide or radiation-exposure have been ameliorated by turmeric administration. It could be concluded that turmeric might protect from oxidative stress

  1. Late biological effects of ionizing radiation as influenced by dose, dose rate, age at exposure, and genetic sensitivity to neoplastic transformation

    International Nuclear Information System (INIS)

    Spalding, J.F.; Prine, J.R.; Tietjen, G.L.

    1978-01-01

    A most comprehensive investigation is in progress at the Los Alamos Scientific Laboratory to study the late biological effects of whole-body exposure to gamma irradiation as they may be influenced by total dose, dose rate, age at exposure, and genetic background. Strain C57B1/6J mice of four age groups (newborn, 2, 6, and 15 months) were given five doses (20, 60, 180, 540, and 1620 rad) of gamma rays, with each dose being delivered at six dose rates (0.7, 2.1, 6.3, 18.9, 56.7 rad/day and 25 rad/min). Forty to sixty mice were used in each of the approximately 110 dose/dose-rate and age combinations. The study was done in two replications with an equal number of mice per replication. Strain RF/J mice were used in a companion study to investigate the influence of genetic background on the type and magnitude of effect. Results of the first and second replications of the 15-month-old age group and data on the influence of genetic background on biological response have been completed, and the results show no significant life shortening within the dose and dose-rate range used

  2. Late biological effects of ionizing radiation as influenced by dose, dose rate, age at exposure and genetic sensitivity to neoplastic transformation

    International Nuclear Information System (INIS)

    Spalding, J.F.; Prine, J.R.; Tietjen, G.L.

    1978-01-01

    A most comprehensive investigation is in progress at the Los Alamos Scientific Laboratory to study the late biological effects of whole-body exposure to gamma irradiation as they may be influenced by total dose, dose rate, age at exposure and genetic background. Strain C57B1/6J mice of four age groups (newborn, 2, 6 and l5 months) were given five doses (20, 60, 180, 540, and 1620 rads) of gamma rays, with each dose being delivered at six dose rates (0.7, 2.1, 6.3, 18.9, 56.7 rads/day and 25 rads/min). Forty to sixty mice were used in each of the approximately 119 dose/dose-rate and age combinations. The study was done in two replications with an equal number of mice per replicaton. Strain RF/J mice were used in a companion study to investigate the influence of genetic background on the type and magnitude of effect. Results of the first and second replications of the l5-month-old age group and data on the influence of genetic background on biological response have been completed, and the results show no significant life shortening within the dose and dose-rate range used. It was also concluded that radiaton-induced neoplastic transformaton was significantly greater in mice with a known genetic sensitivity to neoplastic disease than in mammals which do not normally have a significant incidence of tumours. (author)

  3. Relationship of stature to gamma and neutron exposure among atomic bomb survivors aged less than 10 at the time of the bomb, Hiroshima and Nagasaki

    International Nuclear Information System (INIS)

    Ishimaru, Toranosuke; Amano, Takako; Kawamoto, Sadahisa.

    1982-10-01

    A reanalysis has been undertaken of the relationship of attained adult height of Hiroshima and Nagasaki atomic bomb survivors aged less than 10 at the time of the bomb (ATB) to radiation dose based upon new dosimetry data. The present analysis aims to examine the relationship of stature to radiation dose in terms of gamma rays and neutrons, separately. The 628 individuals were selected from Hiroshima and Nagasaki survivors, aged less than 10 ATB, whose doses were available, and whose statures were recorded at the Adult Health Study (AHS) biennial health examination during 1970-72. To ascertain the relationship of attained adult stature to gamma and neutron doses three doseresponse models were applied to the data. The analysis revealed that the attained height is a separate function of exposure to gamma rays and neutrons. The model assuming a squared term dependence on gamma rays and a linear dependence on neutrons provides a better explanation of the data. The regression coefficient associated with the squared gamma dose is -0.00000927 and the coefficient associated with neutron dose is -0.0172. The relative biological effectiveness of neutrons in relation to gamma radiation with respect to the effect for diminished development of stature is estimated as 43.1 / √Dn in kerma (Dn=neutron dose). The 95% confidence limits are 19.3 / √Dn--96.5 / √Dn. (author)

  4. Methodological study of aging effects on fuel cells using X-ray synchrotron radiography and tomography

    International Nuclear Information System (INIS)

    Arlt, Tobias

    2012-01-01

    In the present work, new and advanced methods for the investigation of methanol and hydrogen powered fuel cells were analyzed. Synchrotron radiography and tomography were applied to investigate materials and transport processes in operating fuel cells ''in-situ'' and non-destructively. The corrosion of ruthenium is a key issue during aging of direct methanol fuel cells (DMFC). Therefore the influence of different aging processes on the distribution of ruthenium is of great interesting. An imaging method based on X-ray absorption spectroscopy (XAS) was applied to investigate the changes in the distribution of fuel cell catalysts three-dimensionally. Using monoenergetic synchrotron radiation it was shown that the distribution of ruthenium (Ru) in the anode catalyst changes after application of an accelerated aging procedure. A strong influence on the flowfield and the gas diffusion layer structures on the Ru distribution were found in the gas diffusion electrode at the anode side. Additionally some ruthenium moves through the membrane from the anode to the cathode. The redistribution caused by the accelerated aging procedure strongly differs from that obtained after aging under realistic stack operation (here over 1700 h) of a fuel cell in a pallet transporter. For the tomographic investigations samples were taken out from a stack operation in aged membrane electrode assembly (MEA) and were analyzed ex-situ. It was shown that the Ru redistribution can be attributed to mass transport processes (CO 2 and H 2 O) in the gas diffusion layer (GDL). Other high energy resolved measurements showed that the strength of the oxidation of ruthenium and platinum depends on the spatial distribution of the ruthenium. Last mentioned - also for the platinum catalyst - could be given quantitatively by means of this newly developed method. In the second part of this work high temperature polymer electrolyte fuel cells (HT-PEFC) were investigated. No liquid water can

  5. Radiation-hygienic assessment of theroid exposure in children resulted from X-ray examination of chest organs

    International Nuclear Information System (INIS)

    Kostenetskij, M.I.

    1983-01-01

    Radiation doses for thyroid in children in the case of X-ray examination of chest organs with the aim of optimization of investigation regimes are studied. Dosimetric measurements are performed in aqueous plexiglass phantoms imitating children of different age. It is shown that the maximum radiation dose for thyroid is registered in breast-fed children and constitutes, about 50% of the annual radiation background; in the older age it constiturotes 8-10% of the natural annual radiation backgund. The increase of intensity at the X-ray tube with the simultaneous decrease of explosure in the case of constant filtration of radiation gives the increase of radiation dose of thyroid in breast-fed children are inconsiderable; in older children, approximately in 1.7 times

  6. Aging and photo-aging DNA repair phenotype of skin cells-Evidence toward an effect of chronic sun-exposure

    Energy Technology Data Exchange (ETDEWEB)

    Prunier, Chloe; Masson-Genteuil, Gwenaeelle [Laboratoire Lesions des Acides Nucleiques, CEA, DSM, INAC, SCIB, UMR-E CEA/UJF-Grenoble 1, 17 Rue des Martyrs, F-38054 Grenoble Cedex 9 (France); Ugolin, Nicolas [Laboratoire de Cancerologie Experimentale, CEA, DSV, IRCM, SREIT, BP6, Fontenay-aux-Roses Cedex F-92265 (France); Sarrazy, Fanny [Laboratoire Lesions des Acides Nucleiques, CEA, DSM, INAC, SCIB, UMR-E CEA/UJF-Grenoble 1, 17 Rue des Martyrs, F-38054 Grenoble Cedex 9 (France); Sauvaigo, Sylvie, E-mail: sylvie.sauvaigo@cea.fr [Laboratoire Lesions des Acides Nucleiques, CEA, DSM, INAC, SCIB, UMR-E CEA/UJF-Grenoble 1, 17 Rue des Martyrs, F-38054 Grenoble Cedex 9 (France)

    2012-08-01

    Several studies have demonstrated the deleterious effect of aging on the capacity of cells to repair their DNA. However, current existing assays aimed at measuring DNA repair address only a specific repair step dedicated to the correction of a specific DNA lesion type. Consequently they provide no information regarding the repair pathways that handle other types of lesions. In addition to aging, consequences of photo-exposure on these repair processes remain elusive. In this study we evaluated the consequence of aging and of chronic and/or acute photo-exposure on DNA repair in human skin fibroblasts using a multiplexed approach, which provided detailed information on several repair pathways at the same time. The resulting data were analyzed with adapted statistics/bioinformatics tools. We showed that, irrespective of the repair pathway considered, excision/synthesis was less efficient in non-exposed cells from elderly compared to cells from young adults and that photo-exposure disrupted this very clear pattern. Moreover, it was evidenced that chronic sun-exposure induced changes in DNA repair properties. Finally, the identification of a specific signature at the level of the NER pathway in cells repeatedly exposed to sun revealed a cumulative effect of UVB exposure and chronic sun irradiation. The uses of bioinformatics tools in this study was essential to fully take advantage of the large sum of data obtained with our multiplexed DNA repair assay and unravel the effects of environmental exposure on DNA repair pathways.

  7. Biomarkers of oxidative stress and inflammation after wood smoke exposure in a reconstructed Viking Age house.

    Science.gov (United States)

    Jensen, Annie; Karottki, Dorina Gabriela; Christensen, Jannie Marie; Bønløkke, Jakob Hjort; Sigsgaard, Torben; Glasius, Marianne; Loft, Steffen; Møller, Peter

    2014-10-01

    Exposure to particles from combustion of wood is associated with respiratory symptoms, whereas there is limited knowledge about systemic effects. We investigated effects on systemic inflammation, oxidative stress and DNA damage in humans who lived in a reconstructed Viking Age house, with indoor combustion of wood for heating and cooking. The subjects were exposed to high indoor concentrations of PM2.5 (700-3,600 µg/m(3)), CO (10.7-15.3 ppm) and NO2 (140-154 µg/m(3)) during a 1-week stay. Nevertheless, there were unaltered levels of genotoxicity, determined as DNA strand breaks and formamidopyrimidine DNA glycosylase and oxoguanine DNA glycosylase 1 sensitive sites in peripheral blood mononuclear cells. There were also unaltered expression levels of OGG1, HMOX1, CCL2, IL8, and TNF levels in leukocytes. In serum, there were unaltered levels of C-reactive protein, IL6, IL8, TNF, lactate dehydrogenase, cholesterol, triglycerides, and high-density lipoproteins. The wood smoke exposure was associated with decreased serum levels of sICAM-1, and a tendency to decreased sVCAM-1 levels. There was a minor increase in the levels of circulating monocytes expressing CD31, whereas there were unaltered expression levels of CD11b, CD49d, and CD62L on monocytes after the stay in the house. In conclusion, even a high inhalation exposure to wood smoke was associated with limited systemic effects on markers of oxidative stress, DNA damage, inflammation, and monocyte activation. © 2014 Wiley Periodicals, Inc.

  8. Pesticide exposure of two age groups of women and its relationship with their diet

    International Nuclear Information System (INIS)

    Rivas, Ana; Cerrillo, Isabel; Granada, Alicia; Mariscal-Arcas, Miguel; Olea-Serrano, Fatima

    2007-01-01

    The widespread presence of organochlorine (OC) pesticides in human samples may be explained by the environmental exposure of the population. Foods are considered a constant source of exposure, despite compliance with maximum permitted residue levels. This study aimed to examine the relationship between nutritional habits of women in Southeast Spain and their serum concentrations of OCs. A semi-quantitative questionnaire was used to estimate the frequency of consumption of foods by two age groups of women, pre-menopausal (Pre-M) and post-menopausal (Post-M), and their serum pesticide levels were measured by gas chromatography (GC) with electron capture detector and confirmed by GC and mass spectrometry. The Pre-M group showed significantly higher serum concentrations of all OCs studied with the exception of DDE. The groups significantly differed in consumption of all food groups with the exception of fruit. In the Pre-M group, the mean serum p,p-DDT concentration was significantly associated with milk/yoghurt (p < 0.045) and red meat (p < 0.023), serum o,p-DDT with red meat (p < 0.049), serum aldrin with eggs (p < 0.038) and poultry (p < 0.024), and serum DDE with eggs (p < 0.025). In the Post-M group, serum lindane was associated with fresh and cured cheese (p < 0.001), red meat (p < 0.001) and white and oily fish (p < 0.001), and both serum DDE and dieldrin were associated with fresh cheese, cured cheese, red meat, and white and oily fish (p < 0.001). These results confirm foods as a source of human exposure to persistent organic molecules. Consideration should be given to the reduction of permitted residue levels to minimize this threat to human and animal health

  9. Pesticide exposure of two age groups of women and its relationship with their diet

    Energy Technology Data Exchange (ETDEWEB)

    Rivas, Ana [Department of Nutrition and Food Science, University of Granada (Spain); Cerrillo, Isabel [Department of Nutrition and Food Science, University of Granada (Spain); Granada, Alicia [Department of Nutrition and Food Science, University of Granada (Spain); Mariscal-Arcas, Miguel [Department of Nutrition and Food Science, University of Granada (Spain); Olea-Serrano, Fatima [Department of Nutrition and Food Science, University of Granada (Spain)]. E-mail: folea@ugr.es

    2007-08-15

    The widespread presence of organochlorine (OC) pesticides in human samples may be explained by the environmental exposure of the population. Foods are considered a constant source of exposure, despite compliance with maximum permitted residue levels. This study aimed to examine the relationship between nutritional habits of women in Southeast Spain and their serum concentrations of OCs. A semi-quantitative questionnaire was used to estimate the frequency of consumption of foods by two age groups of women, pre-menopausal (Pre-M) and post-menopausal (Post-M), and their serum pesticide levels were measured by gas chromatography (GC) with electron capture detector and confirmed by GC and mass spectrometry. The Pre-M group showed significantly higher serum concentrations of all OCs studied with the exception of DDE. The groups significantly differed in consumption of all food groups with the exception of fruit. In the Pre-M group, the mean serum p,p-DDT concentration was significantly associated with milk/yoghurt (p < 0.045) and red meat (p < 0.023), serum o,p-DDT with red meat (p < 0.049), serum aldrin with eggs (p < 0.038) and poultry (p < 0.024), and serum DDE with eggs (p < 0.025). In the Post-M group, serum lindane was associated with fresh and cured cheese (p < 0.001), red meat (p < 0.001) and white and oily fish (p < 0.001), and both serum DDE and dieldrin were associated with fresh cheese, cured cheese, red meat, and white and oily fish (p < 0.001). These results confirm foods as a source of human exposure to persistent organic molecules. Consideration should be given to the reduction of permitted residue levels to minimize this threat to human and animal health.

  10. Intrauterine nicotine exposure, birth weight, gestational age and the risk of infantile colic

    DEFF Research Database (Denmark)

    Milidou, Ioanna; Søndergaard, Charlotte; Jensen, Morten Søndergaard

    Background and aim: Infantile colic is characterised by crying bouts in a healthy infant during the first months. Smoking in pregnancy and low birth weight (BW) have been previously identified as risk factors for infantile colic. Nicotine acts as a neurotransmitter and is known to affect the intr......Background and aim: Infantile colic is characterised by crying bouts in a healthy infant during the first months. Smoking in pregnancy and low birth weight (BW) have been previously identified as risk factors for infantile colic. Nicotine acts as a neurotransmitter and is known to affect...... the intrauterine central nervous system development, while low BW and premature birth have both been related to adverse neurodevelopmental outcomes. We investigated the association between intrauterine nicotine exposure, BW, gestational age (GA) and infantile colic in a large cohort study. Materials and methods......: We used data from the Danish National Birth Cohort. The study on nicotine exposure included 63,128 infants and the study on BW and GA included 62, 785 infants with complete data. Infantile colic was defined according to the modified Wessel’s criteria based on maternal interview 6 months postpartum...

  11. Occupational exposure and risks associated with the X-ray and gamma ray scanners used for destination inspection at the port of Tema, Ghana

    International Nuclear Information System (INIS)

    Gbormittah, S.V.

    2010-01-01

    The x-ray linear accelerator scanner with average energy of 5 MeV operated by the Gateway Services Limited (GSL) and the Cobalt-60 gamma ray scanner with average energy of 1.25 MeV operated by the Ghana Customs Inspection Company Limited (GCIC) have been in use for destination inspection at the Port of Tema for the past ten (10) and six (6) years respectively. For radiation protection purposes, there is the need to assess the risk of exposure to ensure that Staff are not unduly overexposed to minimize the likelihood of adverse radiation effects. The prime objective of this research was to compare the risks from exposure, working conditions and safety culture of the two facilities in order to determine the facility that gives higher levels of exposure to the workers. Data was collected by means of questionnaires and measurements at the two facilities for a period of eight (8) weeks. Personal monitoring data for the occupationally exposed workers of the two facilities for a period sixty-one (61) months were obtained from the Personal Monitoring Laboratory of the Radiation Protection Board; these data were used for mean annual dose, mean annual collective dose and risks assessments for Staff of the two facilities. Ambient dose measurements were carried out with a calibrated Thermo Electron Micro Sievert Doserate survey meter and LiF TLD-100 dosimeters at selected points in the two facilities were 1.16 mSv/a and 1.41 mSv/a respectively. The mean annual effective doses estimated for the collective doses were 8.1man-Sv and 21.15 man-Sv for Staff of GSL and GCIC respectively. Assessment of risks using the ICRP 103 and 60 risk assessment models indicated that Staff of GSL and GCIC had a 0.14% and 0.17% risk of developing fatal cancer respectively. Staff of GSL had a 0.02% risk of passing on adverse hereditary traits to offsprings born after exposure while Staff of GCIC had a hereditary risk of 0.03% of passing on adverse hereditary traits to offsprings born after exposure

  12. The X-Ray Luminosity Functions of Field Low-Mass X-Ray Binaries in Early-Type Galaxies: Evidence for a Stellar Age Dependence

    Science.gov (United States)

    Lehmer, B. D.; Berkeley, M.; Zezas, A.; Alexander, D. M.; Basu-Zych, A.; Bauer, F. E.; Brandt, W. N.; Fragos, T.; Hornschemeier, A. E.; Kalogera, V.; hide

    2014-01-01

    We present direct constraints on how the formation of low-mass X-ray binary (LMXB) populations in galactic fields depends on stellar age. In this pilot study, we utilize Chandra and Hubble Space Telescope (HST) data to detect and characterize the X-ray point source populations of three nearby early-type galaxies: NGC 3115, 3379, and 3384. The luminosity-weighted stellar ages of our sample span approximately equal to 3-10 Gyr. X-ray binary population synthesis models predict that the field LMXBs associated with younger stellar populations should be more numerous and luminous per unit stellar mass than older populations due to the evolution of LMXB donor star masses. Crucially, the combination of deep Chandra and HST observations allows us to test directly this prediction by identifying and removing counterparts to X-ray point sources that are unrelated to the field LMXB populations, including LMXBs that are formed dynamically in globular clusters, Galactic stars, and background AGN/galaxies. We find that the "young" early-type galaxy NGC 3384 (approximately equals 2-5 Gyr) has an excess of luminous field LMXBs (L(sub x) approximately greater than (5-10) × 10(exp 37) erg s(exp -1)) per unit K-band luminosity (L(sub K); a proxy for stellar mass) than the "old" early-type galaxies NGC 3115 and 3379 (approximately equals 8-10 Gyr), which results in a factor of 2-3 excess of L(sub X)/L(sub K) for NGC 3384. This result is consistent with the X-ray binary population synthesis model predictions; however, our small galaxy sample size does not allow us to draw definitive conclusions on the evolution field LMXBs in general. We discuss how future surveys of larger galaxy samples that combine deep Chandra and HST data could provide a powerful new benchmark for calibrating X-ray binary population synthesis models.

  13. Quantifying risk over the life course - latency, age-related susceptibility, and other time-varying exposure metrics.

    Science.gov (United States)

    Wang, Molin; Liao, Xiaomei; Laden, Francine; Spiegelman, Donna

    2016-06-15

    Identification of the latency period and age-related susceptibility, if any, is an important aspect of assessing risks of environmental, nutritional, and occupational exposures. We consider estimation and inference for latency and age-related susceptibility in relative risk and excess risk models. We focus on likelihood-based methods for point and interval estimation of the latency period and age-related windows of susceptibility coupled with several commonly considered exposure metrics. The method is illustrated in a study of the timing of the effects of constituents of air pollution on mortality in the Nurses' Health Study. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

  14. Quantifying Risk Over the Life Course – Latency, Age-Related Susceptibility, and Other Time-Varying Exposure Metrics

    Science.gov (United States)

    Wang, Molin; Liao, Xiaomei; Laden, Francine; Spiegelman, Donna

    2016-01-01

    Identification of the latency period and age-related susceptibility, if any, is an important aspect of assessing risks of environmental, nutritional and occupational exposures. We consider estimation and inference for latency and age-related susceptibility in relative risk and excess risk models. We focus on likelihood-based methods for point and interval estimation of the latency period and age-related windows of susceptibility coupled with several commonly considered exposure metrics. The method is illustrated in a study of the timing of the effects of constituents of air pollution on mortality in the Nurses’ Health Study. PMID:26750582

  15. Reducing exposure of X-ray radiodiagnosis personnel with use of apron

    International Nuclear Information System (INIS)

    Snobr, J.

    1988-01-01

    Experimental results are presented showing dose reduction in X-ray irradiation thanks to protective aprons from lead-containing rubber. The values were used to calculate a reduction in the effective dose equivalent while using the protective apron for isotropic irradiation and for frontal irradiation. A method for optimizing the lead equivalent of the protective apron is suggested. (author). 7 tabs., 6 refs

  16. X-ray exposure hazards for physicians performing ablation procedures and device implantation

    DEFF Research Database (Denmark)

    Marinskis, Germanas; Bongiorni, Maria Grazia; Dagres, Nikolaos

    2013-01-01

    The purpose of the survey was to evaluate physician's and authorities policies and clinical practices when using occupational X-ray during ablation procedures and device implantation. This survey shows infrequent use of lead gloves, radiation absorbing pads, and lead glass cabins, but increasing ...

  17. Relative biological effectiveness (RBE) of fission neutrons and gamma rays at occupational exposure levels: Volume 1, Studies on the genetic effects in mice of 60 equal once-weekly exposures to fission neutrons and gamma rays

    International Nuclear Information System (INIS)

    Grahn, D.; Carnes, B.A.

    1987-10-01

    The relative biological effectiveness (RBE) values for low doses of fission neutrons compared to 60 Co gamma rays were determined with four separate assessments of genetic damage induced in young hybrid male mice. Both radiations were delivered at low dose levels over about one-half the adult lifetime as 60 once-weekly exposures. Genetic damage assessed included both transient and residual injury. The latter is more critical, as residual genetic injury can be transmitted to subsequent generations long after the radiation exposures have ceased. Assays were performed periodically during the 60-week exposure period and at 10 or more weeks after the irradiations had terminated. RBE values, with few exceptions, ranged between 5 and 15 for transient injury and between 25 and 50 for different types of residual genetic injury. The most important form of residual genetic damage in this study was the balanced reciprocal chromosome translocation. These translocations continue to be transmitted throughout reproductive life and can lead to reduced fertility and increased prenatal mortality. The best estimate of the RBE value for translocations was 45 +- 10. Implications and recommendations with regard to the neutron quality factor will be presented conjointly with the findings from the data obtained in this same project on life shortening and on the risks of incidence or death from neoplastic disease. 64 refs., 23 tabs

  18. DEVELOPMENT OF DIAGNOSTIC REFERENCE LEVELS (DRL OF PATIENTS X-RAY EXPOSURE IN DIAGNOSTIC RADIOLOGY

    Directory of Open Access Journals (Sweden)

    A. V. Vodovatov

    2013-01-01

    Full Text Available We introduce a system of Diagnostic Reference Levels (DRLs for patients medical exposure for national health care practice implementation. DRLs are an effective way of the patient radiation protection through the optimization of the medical exposure. The paper discusses and compares different methods of determining the DRLs based on measured and/or calculated quantities of patient’s dose: dose area product (DAP, entrance surface dose (ESD and an effective dose. Distributions of different dose quantities in different Saint-Petersburg clinics are shown on the example of chest PA examinations. The results are compared with the data from other sources. Regional DRLs for Saint-Petersburg are proposed.

  19. Studies on the radiation exposure and protection at the X-ray radiography in the medical care at home

    International Nuclear Information System (INIS)

    Suzuki, Shoichi; Fujii, Shigehisa; Asada, Yasuo; Orito, Takeo; Kamei, Tetsuya; Koga, Sukehiko

    1998-01-01

    Since there are scarce studies on the exposure and protection at the radiography in the medical care at home, authors performed such studies as comparison of doses from self-rectifying and inverter tubes, exposure and protection to patients and nursing persons and actual measurement (October, 1997) at home in Tohno city, Iwate prefecture, of scattering radiation dose at radiography. Apparatuses used were: Portable X-ray equipments; self-rectifying types (Toshiba TR-20 and Medisonacoma PX 30N) and an inverter type (Medisonacoma PX-15HF), Kyoto Kagaku WAC water phantom, X-ray analyzer Model 200 of Kasei Optonics, and Dosimeters (Victoreen Radocon ionization dosimeter and Aloka ICS-301 ionization chamber survey meters). Radiation qualities, surface doses and scattering doses of the equipments under various conditions were compared by the half value layer and effective energy measured with the analyzer. Actual measurement of scattering dose was done at home for 4 patients at chest radiography. Annual dose in monthly ordinary radiography at home, when the distance was >200 cm far from the flux center, was found about 1/100 of 1 mSv (the annual public dose limit), thus securing the safety of nurses. (K.H.)

  20. Studies on the radiation exposure and protection at the X-ray radiography in the medical care at home

    Energy Technology Data Exchange (ETDEWEB)

    Suzuki, Shoichi; Fujii, Shigehisa; Asada, Yasuo; Orito, Takeo [Fujita Health Univ., Toyoake, Aichi (Japan). School of Health Science; Kamei, Tetsuya; Koga, Sukehiko

    1998-12-01

    Since there are scarce studies on the exposure and protection at the radiography in the medical care at home, authors performed such studies as comparison of doses from self-rectifying and inverter tubes, exposure and protection to patients and nursing persons and actual measurement (October, 1997) at home in Tohno city, Iwate prefecture, of scattering radiation dose at radiography. Apparatuses used were: Portable X-ray equipments; self-rectifying types (Toshiba TR-20 and Medisonacoma PX 30N) and an inverter type (Medisonacoma PX-15HF), Kyoto Kagaku WAC water phantom, X-ray analyzer Model 200 of Kasei Optonics, and Dosimeters (Victoreen Radocon ionization dosimeter and Aloka ICS-301 ionization chamber survey meters). Radiation qualities, surface doses and scattering doses of the equipments under various conditions were compared by the half value layer and effective energy measured with the analyzer. Actual measurement of scattering dose was done at home for 4 patients at chest radiography. Annual dose in monthly ordinary radiography at home, when the distance was >200 cm far from the flux center, was found about 1/100 of 1 mSv (the annual public dose limit), thus securing the safety of nurses. (K.H.)

  1. Age of first exposure to American football and long-term neuropsychiatric and cognitive outcomes

    Science.gov (United States)

    Alosco, M L; Kasimis, A B; Stamm, J M; Chua, A S; Baugh, C M; Daneshvar, D H; Robbins, C A; Mariani, M; Hayden, J; Conneely, S; Au, R; Torres, A; McClean, M D; McKee, A C; Cantu, R C; Mez, J; Nowinski, C J; Martin, B M; Chaisson, C E; Tripodis, Y; Stern, R A

    2017-01-01

    Previous research suggests that age of first exposure (AFE) to football before age 12 may have long-term clinical implications; however, this relationship has only been examined in small samples of former professional football players. We examined the association between AFE to football and behavior, mood and cognition in a large cohort of former amateur and professional football players. The sample included 214 former football players without other contact sport history. Participants completed the Brief Test of Adult Cognition by Telephone (BTACT), and self-reported measures of executive function and behavioral regulation (Behavior Rating Inventory of Executive Function-Adult Version Metacognition Index (MI), Behavioral Regulation Index (BRI)), depression (Center for Epidemiologic Studies Depression Scale (CES-D)) and apathy (Apathy Evaluation Scale (AES)). Outcomes were continuous and dichotomized as clinically impaired. AFE was dichotomized into football before age 12 corresponded with >2 × increased odds for clinically impaired scores on all measures but BTACT: (odds ratio (OR), 95% confidence interval (CI): BRI, 2.16,1.19–3.91; MI, 2.10,1.17–3.76; CES-D, 3.08,1.65–5.76; AES, 2.39,1.32–4.32). Younger AFE predicted increased odds for clinical impairment on the AES (OR, 95% CI: 0.86, 0.76–0.97) and CES-D (OR, 95% CI: 0.85, 0.74–0.97). There was no interaction between AFE and highest level of play. Younger AFE to football, before age 12 in particular, was associated with increased odds for impairment in self-reported neuropsychiatric and executive function in 214 former American football players. Longitudinal studies will inform youth football policy and safety decisions. PMID:28926003

  2. Age of first exposure to American football and long-term neuropsychiatric and cognitive outcomes.

    Science.gov (United States)

    Alosco, M L; Kasimis, A B; Stamm, J M; Chua, A S; Baugh, C M; Daneshvar, D H; Robbins, C A; Mariani, M; Hayden, J; Conneely, S; Au, R; Torres, A; McClean, M D; McKee, A C; Cantu, R C; Mez, J; Nowinski, C J; Martin, B M; Chaisson, C E; Tripodis, Y; Stern, R A

    2017-09-19

    Previous research suggests that age of first exposure (AFE) to football before age 12 may have long-term clinical implications; however, this relationship has only been examined in small samples of former professional football players. We examined the association between AFE to football and behavior, mood and cognition in a large cohort of former amateur and professional football players. The sample included 214 former football players without other contact sport history. Participants completed the Brief Test of Adult Cognition by Telephone (BTACT), and self-reported measures of executive function and behavioral regulation (Behavior Rating Inventory of Executive Function-Adult Version Metacognition Index (MI), Behavioral Regulation Index (BRI)), depression (Center for Epidemiologic Studies Depression Scale (CES-D)) and apathy (Apathy Evaluation Scale (AES)). Outcomes were continuous and dichotomized as clinically impaired. AFE was dichotomized into football before age 12 corresponded with >2 × increased odds for clinically impaired scores on all measures but BTACT: (odds ratio (OR), 95% confidence interval (CI): BRI, 2.16,1.19-3.91; MI, 2.10,1.17-3.76; CES-D, 3.08,1.65-5.76; AES, 2.39,1.32-4.32). Younger AFE predicted increased odds for clinical impairment on the AES (OR, 95% CI: 0.86, 0.76-0.97) and CES-D (OR, 95% CI: 0.85, 0.74-0.97). There was no interaction between AFE and highest level of play. Younger AFE to football, before age 12 in particular, was associated with increased odds for impairment in self-reported neuropsychiatric and executive function in 214 former American football players. Longitudinal studies will inform youth football policy and safety decisions.

  3. Persistent Associations between Maternal Prenatal Exposure to Phthalates on Child IQ at Age 7 Years.

    Directory of Open Access Journals (Sweden)

    Pam Factor-Litvak

    Full Text Available Prior research reports inverse associations between maternal prenatal urinary phthalate metabolite concentrations and mental and motor development in preschoolers. No study evaluated whether these associations persist into school age.In a follow up of 328 inner-city mothers and their children, we measured prenatal urinary metabolites of di-n-butyl phthalate (DnBP, butylbenzyl phthalate (BBzP, di-isobutyl phthalate (DiBP, di-2-ethylhexyl phthalate and diethyl phthalate in late pregnancy. The Wechsler Intelligence Scale for Children, 4th edition was administered at child age 7 years and evaluates four areas of cognitive function associated with overall intelligence quotient (IQ.Child full-scale IQ was inversely associated with prenatal urinary metabolite concentrations of DnBP and DiBP: b = -2.69 (95% confidence interval [CI] = -4.33, -1.05 and b = -2.69 (95% CI = -4.22, -1.16 per log unit increase. Among children of mothers with the highest versus lowest quartile DnBP and DiBP metabolite concentrations, IQ was 6.7 (95% CI = 1.9, 11.4 and 7.6 (95% CI = 3.2, 12.1 points lower, respectively. Associations were unchanged after control for cognition at age 3 years. Significant inverse associations were also seen between maternal prenatal metabolite concentrations of DnBP and DiBP and child processing speed, perceptual reasoning and working memory; DiBP and child verbal comprehension; and BBzP and child perceptual reasoning.Maternal prenatal urinary metabolite concentrations measured in late pregnancy of DnBP and DiBP are associated with deficits in children's intellectual development at age 7 years. Because phthalate exposures are ubiquitous and concentrations seen here within the range previously observed among general populations, results are of public health significance.

  4. The restless universe understanding X-ray astronomy in the age of Chandra and Newton

    CERN Document Server

    Schlegel, Eric M

    2002-01-01

    This title tells the story of the development and launch of a major space-based telescope, and explains the discoveries of the nature of the universe in the X-ray spectre. The author looks at the brief history of X-ray astronomy to explore what can and has been learnt by using X-ray.

  5. Assessing dietary exposure to cadmium in a metal recycling community in Vietnam: Age and gender aspects

    Energy Technology Data Exchange (ETDEWEB)

    Minh, Ngo Duc [Vietnamese Academy of Agriculture Sciences, Soils and Fertilizers Research Institute (SFRI), Tu Liem, Hanoi (Viet Nam); Hough, Rupert Lloyd, E-mail: rupert.hough@hutton.ac.uk [The James Hutton Institute, Craigiebuckler, Aberdeen, AB15 8QH (United Kingdom); Thuy, Le Thi [Vietnamese Academy of Agriculture Science, Institute of Agricultural Environment (IAE), Tu Liem, Hanoi (Viet Nam); Nyberg, Ylva [Department of Crop Production Ecology, PO Box 7043, Swedish University of Agricultural Sciences (SLU), SE-750 07 Uppsala (Sweden); Mai, Le Bach [National Institute of Nutrition, 48b Tang Bat Ho, Hoan Kiem, Hanoi (Viet Nam); Vinh, Nguyen Cong [Vietnamese Academy of Agriculture Sciences, Soils and Fertilizers Research Institute (SFRI), Tu Liem, Hanoi (Viet Nam); Khai, Nguyen Manh [Faculty of Environmental Sciences, Ha Noi University of Science (HUS-VNU), 334 Nguyen Trai, Thanh Xuan, Ha Noi (Viet Nam); Oeborn, Ingrid [Department of Crop Production Ecology, PO Box 7043, Swedish University of Agricultural Sciences (SLU), SE-750 07 Uppsala (Sweden)

    2012-02-01

    This study estimates the dietary exposure to cadmium (Cd), and associated potential health risks, for individuals living and working in a metal recycling community (n = 132) in Vietnam in comparison to an agricultural (reference) community (n = 130). Individual-level exposure to Cd was estimated through analysis of staple foodstuffs combined with information from a food frequency questionnaire. Individual-level exposure estimates were compared with published 'safe' doses to derive a Hazard Quotient (HQ) for each member of the study population. Looking at the populations as a whole, there were no significant differences in the diets of the two villages. However, significantly more rice was consumed by working age adults (18-60 years) in the recycling village compared to the reference village (p < 0.001). Rice was the main staple food with individuals consuming 461 {+-} 162 g/d, followed by water spinach (103 {+-} 51 kg/d). Concentrations of Cd in the studied foodstuffs were elevated in the metal recycling village. Values of HQ exceeded unity for 87% of adult participants of the metal recycling community (39% had a HQ > 3), while 20% of adult participants from the reference village had an HQ > 1. We found an elevated health risk from dietary exposure to Cd in the metal recycling village compared to the reference community. WHO standard of 0.4 mg Cd/kg rice may not be protective where people consume large amounts of rice/have relatively low body weight. - Highlights: Black-Right-Pointing-Pointer First individual-level risk assessment of cadmium in recycling villages of Vietnam. Black-Right-Pointing-Pointer Dietary analysis undertaken for a recycling community and an agricultural community. Black-Right-Pointing-Pointer No significant differences were found between the diets of the two populations. Black-Right-Pointing-Pointer 87% of people in the recycling community had elevated health risk. Black-Right-Pointing-Pointer WHO standard (0.4 mg Cd/kg rice) may

  6. Secondhand tobacco smoke exposure differentially alters nucleus tractus solitarius neurons at two different ages in developing non-human primates

    International Nuclear Information System (INIS)

    Sekizawa, Shin-ichi; Joad, Jesse P.; Pinkerton, Kent E.; Bonham, Ann C.

    2010-01-01

    Exposing children to secondhand tobacco smoke (SHS) is associated with increased risk for asthma, bronchiolitis and SIDS. The role for changes in the developing CNS contributing to these problems has not been fully explored. We used rhesus macaques to test the hypothesis that SHS exposure during development triggers neuroplastic changes in the nucleus tractus solitarius (NTS), where lung sensory information related to changes in airway and lung function is first integrated. Pregnant monkeys were exposed to filtered air (FA) or SHS for 6 h/day, 5 days/week starting at 50-day gestational age. Mother/infant pairs continued the exposures postnatally to age 3 or 13 months, which may be equivalent to approximately 1 or 4 years of human age, respectively. Whole-cell recordings were made of second-order NTS neurons in transverse brainstem slices. To target the consequences of SHS exposure based on neuronal subgroups, we classified NTS neurons into two phenotypes, rapid-onset spiking (RS) and delayed-onset spiking (DS), and then evaluated intrinsic and synaptic excitabilities in FA-exposed animals. RS neurons showed greater cell excitability especially at age of 3 months while DS neurons received greater amplitudes of excitatory postsynaptic currents (EPSCs). Developmental neuroplasticity such as increases in intrinsic and synaptic excitabilities were detected especially in DS neurons. In 3 month olds, SHS exposure effects were limited to excitatory changes in RS neurons, specifically increases in evoked EPSC amplitudes and increased spiking responses accompanied by shortened action potential width. By 13 months, the continued SHS exposure inhibited DS neuronal activity; decreases in evoked EPSC amplitudes and blunted spiking responses accompanied by prolonged action potential width. The influence of SHS exposure on age-related and phenotype specific changes may be associated with age-specific respiratory problems, for which SHS exposure can increase the risk, such as SIDS

  7. LEXICAL KNOWLEDGE IN INSTRUCTED LANGUAGE LEARNING: THE EFFECTS OF AGE AND EXPOSURE

    Directory of Open Access Journals (Sweden)

    Inmaculada Miralpeix

    2007-12-01

    Full Text Available The aim of this study is to analyse the possible effects of Age of Onset (AO, Cognitive Maturity (Age at Testing-AT- and Amount of Exposure (AE on the productive vocabularies of learners of English as a Foreign Language (FL. Three groups of bilingual Catalan/Spanish students were tested towards the end of Secondary Education. The groups differed in AO (8 vs. 11 years, AT (16 vs.17 and AE (726 vs. 800 hours. They performed four different tasks: three oral (an interview, a storytelling and a roleplay and one written (a composition. The tasks were analysed with measures extrinsic to the learners’ production. Firstly, their Lexical Frequency Profiles were computed with VocabProfile (Nation, 1995. Secondly, P_Lex (Meara, 2001 was used to assess the lexical richness of the texts. Furthermore, Anglo-Saxon and Greco-Latin Cognate indices were obtained for each of the tasks. Results show that an early AO does not necessarily suppose an advantage for Early Starters (ES, as Late Starters’ (LS productive vocabularies are very similar to those of their younger peers.

  8. A laboratory exposure system to study the effects of aging on super-micron aerosol particles

    Energy Technology Data Exchange (ETDEWEB)

    Santarpia, Joshua; Sanchez, Andres L.; Lucero, Gabriel Anthony; Servantes, Brandon Lee; Hubbard, Joshua Allen

    2014-02-01

    A laboratory system was constructed that allows the super-micron particles to be aged for long periods of time under conditions that can simulate a range of natural environments and conditions, including relative humidity, oxidizing chemicals, organics and simulated solar radiation. Two proof-of-concept experiments using a non-biological simulant for biological particles and a biological simulant demonstrate the utility of these types of aging experiments. Green Visolite®, which is often used as a tracer material for model validation experiments, does not degrade with exposure to simulated solar radiation, the actual biological material does. This would indicate that Visolite® should be a good tracer compound for mapping the extent of a biological release using fluorescence as an indicator, but that it should not be used to simulate the decay of a biological particle when exposed to sunlight. The decay in the fluorescence measured for B. thurengiensis is similar to what has been previously observed in outdoor environments.

  9. Study of the argyrophil structures of thymus connective tissue after exposure to X-rays

    International Nuclear Information System (INIS)

    Beletskij, V.K.; Beletskaya, L.V.; Akademiya Meditsinskikh Nauk SSSR, Moscow. Inst. Ehpidemiologii i Mikrobiologii)

    1980-01-01

    Studied are argyrophil structures of thymus connective tissue - histiocytes (appendiculate macrophages) and reticuline fibers after the bulk of lymphoid cells has migrated from the organ due to irradiation of animals with X-rays. 10 intact and 16 experimental guinea pigs subjected to the whole-body irradiation with X-rays in the dose of 1000-3000 rad have been used for investigations. It is shown that argyrophil stroma elements of thymus connective tissue, histiocytes and reticular cells, are rather resistant to X-rays and preserve their argyrophily property in the irradiation with high doses, as well as the epithelial cells of the organ. Paraplastic structures in irradiated animals are expressed more completely being demasked as a result of lymphocyte migration and death. The expressed hypertrophy and proliferation of reticular cells and appendiculate macrophages are probably the response to the alternative process in the organ tissues caused by irradiation. A close structural connection of reticular and epithelial tissues on the territory of both layers of thymus sections is noted

  10. Conventional X-ray examination of hiatus hernia in aged people (31 cases report)

    International Nuclear Information System (INIS)

    Xu Xiaoyuan; Xie Zirong; Liao Chengyang; Xiong Bo

    2008-01-01

    Objective: To evaluate methods and features of X-ray examination in aged people with hiatus hernia. Methods: Imaging features of chest film, fluoroscopy and barium meal examination of 31 cases with hiatus hernia diagnosed by barium meal examination were retrospectively analyzed. Results Sac shadows behind the heart were showed in all 23 cases, including chest film (14/23 cases) and fluoroscopy (9/23 cases), 20 cases of which were irreducible hiatus hernia diagnosed by barium meal immediately. 3 cases were misdiagnosed by the chest film, with occupying lesions of the left lower lung (2/3 cases) or aneurysm of descending aorta (1/3 cases). Gastric mucosa was showed in thorax above the left hemidiaphragm in another 8 cases with hiatus hernia evaluated by barium meal, including 5 cases irreducible hiatus hernia and 3 cases sliding hiatus hernia. Conclusion: Chest film, fluoroscopy and barium meal play different roles in the diagnosis of hiatus hernia. Though chest film and fluoroscopy could detect easily, barium meal is of the most importance in evaluation of hiatus hernia due to its characteristics. (authors)

  11. A CANDIDATE OPTICAL COUNTERPART TO THE MIDDLE AGED γ -RAY PULSAR PSR J1741–2054

    Energy Technology Data Exchange (ETDEWEB)

    Mignani, R. P.; Marelli, M.; Luca, A. De; Salvetti, D.; Belfiore, A. [INAF—Istituto di Astrofisica Spaziale e Fisica Cosmica Milano, via E. Bassini 15, I-20133, Milano (Italy); Testa, V. [INAF—Osservatorio Astronomico di Roma, via Frascati 33, I-00040, Monteporzio (Italy); Pierbattista, M. [Department of Astrophysics and Theory of Gravity, Maria Curie-Sklodowska University, ul. Radziszewskiego 10, 20-031 Lublin (Poland); Razzano, M. [Istituto Nazionale di Fisica Nucleare, Sezione di Pisa, I-56127 Pisa (Italy); Shearer, A.; Moran, P. [Centre for Astronomy, National University of Ireland, Newcastle Road, Galway (Ireland)

    2016-07-10

    We carried out deep optical observations of the middle aged γ -ray pulsar PSR J1741−2054 with the Very Large Telescope (VLT). We identified two objects, of magnitudes m {sub v} = 23.10 ± 0.05 and m {sub v} = 25.32 ± 0.08, at positions consistent with the very accurate Chandra coordinates of the pulsar, the faintest of which is more likely to be its counterpart. From the VLT images we also detected the known bow-shock nebula around PSR J1741−2054. The nebula is displaced by ∼0.″9 (at the 3 σ confidence level) with respect to its position measured in archival data, showing that the shock propagates in the interstellar medium consistently with the pulsar proper motion. Finally, we could not find evidence of large-scale extended optical emission associated with the pulsar wind nebula detected by Chandra , down to a surface brightness limit of ∼28.1 mag arcsec{sup −2}. Future observations are needed to confirm the optical identification of PSR J1741−2054 and characterize the spectrum of its counterpart.

  12. Reported Exposure and Emotional Reactivity to Daily Stressors: The Roles of Adult-Age and Global Perceived Stress

    OpenAIRE

    Stawski, Robert S.; Sliwinski, Martin J.; Almeida, David M.; Smyth, Joshua M.

    2008-01-01

    A central goal of daily stress research is to identify resilience and vulnerability factors associated with exposure and reactivity to daily stressors. The current study examined how age differences and global perceptions of stress relate to exposure and emotional reactivity to daily stressors. Sixty-seven younger (Mage = 20) and 116 older (Mage = 80) adults completed a daily stress diary and measures of positive and negative affect on 6 days over a 14 day period. Participants also completed ...

  13. Development of an algorithm for X-ray exposures using the Panasonic UD-802A thermoluminescent dosemeter

    International Nuclear Information System (INIS)

    McKittrick, Leo; Currivan, Lorraine; Pollard, David; Nicholls, Colyn; Romero, A.M.; Palethorpe, Jeffrey

    2008-01-01

    Full text: As part of its continuous quality improvement the Dosimetry Service of the Radiological Protection Institute of Ireland (RPII) in conjunction with Panasonic Industrial Europe (UK) has investigated further the use of the standard Panasonic algorithm for X-ray exposures using the Panasonic UD-802A TL dosemeter. Originally developed to satisfy the obsolete standard ANSI 13.11-1983, the standard Panasonic dose algorithm has undergone several revisions such as HPS N13.11-2001. This paper presents a dose algorithm that can be used to correct the dose response at low energies such as X-ray radiation using a four element TL dosemeter due to the behaviour of two different independent phosphors. A series of irradiations with a range of energies using N-20 up to Co-60 were carried out with our particular interest being in responses to X-ray irradiations. Irradiations were performed at: RRPPS, University Hospital Birmingham NHS Foundation Trust, U.K.; HPA, U.K. and CIEMAT, Madrid, Spain. Different irradiation conditions were employed which included: X-ray from narrow and wide spectra as described by ISO 4037-1 (1996), and ISO water slab phantom and PMMA slab phantom respectively. Using the UD-802A TLD and UD-854AT hanger combination, the response data from the series of irradiations was utilised to validate and if necessary, modify the photon/beta branches of the algorithm to: 1. Best estimate Hp(10) and Hp(0.07); 2. Provide information on irradiation energies; 3. Verification by performance tests. This work further advances the algorithm developed at CIEMAT whereby a best-fit, polynomial trend is used with the dose response variations between the independent phosphors. (author)

  14. ERX: a software for editing files containing X-ray spectra to be used in exposure computational models

    International Nuclear Information System (INIS)

    Cabral, Manuela O.M.; Vieira, Jose W.; Silva, Alysson G.; Leal Neto, Viriato; Oliveira, Alex C.H.; Lima, Fernando R.A.

    2011-01-01

    Exposure Computational Models (ECMs) are utilities that simulate situations in which occurs irradiation in a given environment. An ECM is composed primarily by an anthropomorphic model (phantom), and a Monte Carlo code (MC). This paper presents a tutorial of the software Espectro de Raios-X (ERX). This software performs reading and numerical and graphical analysis of text files containing diagnostic X-ray spectra for use in algorithms of radioactive sources in the ECMs of a Grupo de Dosimetria Numerica. The ERX allows the user to select one among several X-ray spectrums in the energy range Diagnostic radiology X-Ray most commonly used in radiology clinics. In the current version of the ERX there are two types of input files: the contained in mspectra.dat file and the resulting of MC simulations in Geant4. The software allows the construction of charts of the Probability Density Function (PDF) and Cumulative Distribution Function (CDF) of a selected spectrum as well as the table with the values of these functions and the spectrum. In addition, the ERX allows the user to make comparative analysis between the PDF graphics of the two catalogs of spectra available, besides being can perform dosimetric evaluations with the selected spectrum. A software of this kind is an important computational tool for researchers in numerical dosimetry because of the diversity of Diagnostic radiology X-Ray machines, which implies in a mass of input data highly diverse. And because of this, the ERX provides independence to the group related to the data origin that is contained in the catalogs created, not being necessary to resort to others. (author)

  15. Slow Aging Dynamics and Avalanches in a Gold-Cadmium Alloy Investigated by X-Ray Photon Correlation Spectroscopy

    International Nuclear Information System (INIS)

    Mueller, L.; Waldorf, M.; Klemradt, U.; Gutt, C.; Gruebel, G.; Madsen, A.; Finlayson, T. R.

    2011-01-01

    Results of a x-ray photon correlation spectroscopy experiment on the very weakly first order martensitic transformation of a Au 50.5 Cd 49.5 single crystal are presented. Slow non-equilibrium-dynamics are observed in a narrow temperature interval in the direct vicinity of the otherwise athermal phase transformation. These dynamics are associated with the martensite-aging effect. The dynamical aging is accompanied by an avalanchelike behavior which is identified with an incubation-time phenomenon.

  16. Slow aging dynamics and avalanches in a gold-cadmium alloy investigated by x-ray photon correlation spectroscopy.

    Science.gov (United States)

    Müller, L; Waldorf, M; Gutt, C; Grübel, G; Madsen, A; Finlayson, T R; Klemradt, U

    2011-09-02

    Results of a x-ray photon correlation spectroscopy experiment on the very weakly first order martensitic transformation of a Au50.5Cd49.5 single crystal are presented. Slow non-equilibrium-dynamics are observed in a narrow temperature interval in the direct vicinity of the otherwise athermal phase transformation. These dynamics are associated with the martensite-aging effect. The dynamical aging is accompanied by an avalanchelike behavior which is identified with an incubation-time phenomenon.

  17. Sex and Age Differences in Exposure to Secondhand Smoke at Home among Korean Adolescents: A Nationally Representative Survey.

    Science.gov (United States)

    Hwang, Jun Hyun; Park, Soon-Woo

    2016-02-19

    The authors assessed sex and age differences in secondhand smoke (SHS) exposure among vulnerable adolescent populations. Data from the 2013 Korea Youth Risk Behavior Web-based Survey of 64,499 non-smokers aged 13-18 years were analyzed using multiple logistic regression. Girls were exposed 1.26 times (95% confidence interval, 1.21-1.32) more to home SHS than boys, and the younger adolescents were more likely to be exposed to home SHS than were the older, regardless of sex (p exposure at home. Girls living with current smokers were more likely to be exposed to SHS at home than boys regardless age. Girls and younger adolescents, populations vulnerable to smoke exposure, were more likely to be exposed to SHS at home, even though they should be more protected. It is necessary to improve home SHS awareness, especially among these vulnerable populations.

  18. The x-ray source application test cassette for radiation exposures at the OMEGA laser

    Energy Technology Data Exchange (ETDEWEB)

    Fournier, K. B.; Rekow, V.; Emig, J. [Lawrence Livermore National Laboratory, Livermore, California 94551 (United States); Fisher, J. H.; Newlander, C. D. [Fifth Gait Technologies, Inc., Huntsville, Alabama 35803 (United States); Horton, R. [Gray Research, Inc., Huntsville, Alabama 35806 (United States); Davis, J. [Defense Threat Reduction Agency, Fort Belvoir, Virginia 22060 (United States)

    2012-10-15

    We have designed a sample cassette that can be used to position up to six samples in the OMEGA laser chamber. The cassette accommodates round samples up to 38.1 mm (1.5{sup Double-Prime }) in diameter and square samples up to 27 mm on a side, any of which can be up to 12.7 mm thick. Smaller specimens are centered with spacers. The test cassette allows each sample to have a unique filter scheme, with multiple filter regions in front of each sample. This paper will present mechanical design considerations and operational aspects of the x-ray source application cassette.

  19. Level of radiation exposure to staff in X-ray diagnosis

    International Nuclear Information System (INIS)

    Zol'nikova, N.I.; Moisejtsev, P.I.; Trunov, B.V.

    1976-01-01

    In modern radiological service departments the dose rates at working placesof medical aff directly engaged in diagnostic work were found to range from 7 to 100 mR/h during fuoroscopand up to 1,200 mR/h during roentgenoscopy and ray inematography, respectively. Durig fluocopic work in the operating theatre the monthly doses to staff ranged from 100 to 380 mRfor sugeos and anaesthesists, from 110 to 225 mR for surgical nurses, and from5to 30 roranhesia nurses. AUTHOR)

  20. Comparison of x-ray diagnosis associated radiation exposures in Puerto Rico: 1973 vs. 1968

    International Nuclear Information System (INIS)

    Gileadi, M.; Gileadi, A.E.; Musalem, A.

    1975-01-01

    In general, it can be concluded that comparison of 1973 results obtained to date with parallel values for 1968 show a significant improvement in radiation protection practices in Puerto Rico. This improvement, which concerns the whole of society, is not only a result of technical upgrading of the diagnostic equipment, but also and perhaps more significantly, a result of the utmost efforts of professionals: doctors, radiologists and those in radiation protection, to use diagnostic x-rays judiciously, and to reduce the unavoidable doses to a minimum compatible with the diagnostic objective. (U.S.)

  1. Variations in sensitivity of synchronized Chinese hamster cells to oxic and anoxic X-ray exposures

    International Nuclear Information System (INIS)

    Siracka, E.; Littbrand, B.; Clifton, K.H.; Revesz, L.

    1975-01-01

    V-79 Chinese hamster cells in monolayer cultures on glass surfaces were synchronized by treatment with hydroxyurea and then exposed at different times to X-rays in air or in oxygen-free argon. Survival determinations indicated that the oxygen enhancement ratio (OER) as expressed by the ratio of the respective D 0 values varied over a narrow range in the different phases of the cell cycle. These changes resulted from cyclic alterations in both aerobic and anaerobic D 0 values, possibly in n values. (author)

  2. Moraine preservation and boulder erosion in the tropical Andes: interpreting old surface exposure ages in glaciated valleys

    Science.gov (United States)

    Smith, Jacqueline A.; Finkel, Robert C.; Farber, Daniel L.; Rodbell, Donald T.; Seltzer, Geoffrey O.

    2005-10-01

    Cosmogenic dating provides a long-awaited means of directly dating glacial deposits that pre-date the last glacial cycle. Although the potential benefits of longer chronologies are obvious, the greater uncertainty associated with older cosmogenic ages may be less readily apparent. We illustrate the challenges of developing and interpreting a long chronology using our data from the Peruvian Andes. We used surface exposure dating with cosmogenic radionuclides (CRNs; 10Be and 26Al) to date 140 boulders on moraines in valleys bordering the Junin Plain (11° S, 76° W) in central Peru. Our chronology spans multiple glacial cycles and includes exposure ages greater than 1 million years, which indicate that long-term rates of boulder erosion have been very low. Interpreting the chronology of moraines for glaciations that predate the last glacial cycle is complicated by the need to consider boulder erosion and exhumation, surface uplift, and inheritance of CRNs from previous exposure intervals. As an example, we recalculate exposure ages using our boulder erosion rates (0.3-0.5 metres per million years) and estimated surface uplift rates to emphasise both the challenges involved in interpreting old surface exposure ages and the value of chronological data, even with large uncertainties, when reconstructing the palaeoclimate of a region.

  3. Age and sex dependence in tumorigenesis in mice by continuous low-dose-rate gamma-ray whole-body irradiation

    International Nuclear Information System (INIS)

    Otsu, Hiroshi; Kobayashi, Shigeru; Furuse, Takeshi; Noda, Yuko; Shiragai, Akihiro; Sato, Fumiaki.

    1992-01-01

    We investigated the dependency of sex and age in mice in the induction of neoplasms by gamma-rays from cesium-137 at a low dose rate of 0.375Gy/22h/day. Thymic lymphomas occurred significantly at the same incidence in both sexes, and more frequently when younger mice were exposed to radiation. Strain C57BL/6J mice were divided into 8 groups, which were whole-body irradiated with a total dose of 39Gy for 105 days each. The exposure was begun at 28 days of age (male:AM1, female:AF1), and then stepwise increasing the starting age by 105 days, i.e., from 133 days (AM2 and AF2), from 238 days (AM3 and AF3), and from 343 days (AM4 and AF4), respectively. Unirradiated mice served as control (UM and UF). The incidence of thymic lymphomas was about 60 % in AM1, AM2, AF1 and AF2, 40 % in AM3 and AF3 and 20 % in AF4 and AF4, demonstrating no sex dependency, but a distinct age dependency, for lymphomogenesis. It was proven that mice showed a tendency to become less susceptible to radiation induced thymic lymphoma with increasing age. Concomitantly, life-shortening also was caused, and the greater the degree of life-shortening was, the younger the mice were the start of exposure. Life-shortening was attributed to thymic lymphoma, and hemorrhage and infectious diseases due to the depletion of bone marrow cells. (author)

  4. Behavioural outcome of school-age children after prenatal exposure to coumarins

    NARCIS (Netherlands)

    Wesseling, J; Van Driel, D; Heymans, HSA; Van der Veer, E; Sauer, PJJ; Touwen, BCL; Smrkovsky, M

    In utero exposure to coumarin derivatives may affect the development of the central nervous system of the child, irrespective of the period of exposure in pregnancy. Little is known about effects on development in the long term. The aim of the present study was to determine whether prenatal exposure

  5. Behavioural outcome of school-age children after prenatal exposure to coumarins

    NARCIS (Netherlands)

    Wesseling, J.; van Driel, D.; Heymans, H. S.; Van der Veer, E.; Sauer, P. J.; Touwen, B. C.; Smrkovsky, M.

    2000-01-01

    In utero exposure to coumarin derivatives may affect the development of the central nervous system of the child, irrespective of the period of exposure in pregnancy. Little is known about effects on development in the long term. The aim of the present study was to determine whether prenatal exposure

  6. Radiation exposure to foetus and breasts from dental X-ray examinations: effect of lead shields.

    Science.gov (United States)

    Kelaranta, Anna; Ekholm, Marja; Toroi, Paula; Kortesniemi, Mika

    2016-01-01

    Dental radiography may involve situations where the patient is known to be pregnant or the pregnancy is noticed after the X-ray procedure. In such cases, the radiation dose to the foetus, though low, needs to be estimated. Uniform and widely used guidance on dental X-ray procedures during pregnancy are presently lacking, the usefulness of lead shields is unclear and practices vary. Upper estimates of radiation doses to the foetus and breasts of the pregnant patient were estimated with an anthropomorphic female phantom in intraoral, panoramic, cephalometric and CBCT dental modalities with and without lead shields. The upper estimates of foetal doses varied from 0.009 to 6.9 μGy, and doses at the breast level varied from 0.602 to 75.4 μGy. With lead shields, the foetal doses varied from 0.005 to 2.1 μGy, and breast doses varied from 0.002 to 10.4 μGy. The foetal dose levels without lead shielding were dental radiographic examination.

  7. Abdominal x-ray

    Science.gov (United States)

    Abdominal film; X-ray - abdomen; Flat plate; KUB x-ray ... There is low radiation exposure. X-rays are monitored and regulated to provide the minimum amount of radiation exposure needed to produce the image. Most ...

  8. End of the Golden Age for X-ray Astronomy: Technical and Fiscal Challenges

    Science.gov (United States)

    Elvis, Martin

    2012-09-01

    Golden Ages don't last much more than 50 years (viz. Athens 4th century BCE, Renaissance Italy, Dutch Golden Age) - that's why they're golden. X-ray astronomy is now 50 years old. Should we expect it to continue to flourish? Or is this the end of our Golden Age? Technologically there is tremendous promise. New optics and detectors are set to deliver great improvements along all axes: collecting area, angular and spectral resolution, field of view, polarimetry. To be optimal along a given axis, missions should not try to combine all these improvements in a single mission. Hence specialized missions of modest size (similar to NASA's Explorer class) should be pursued world-wide. Multiple missions also support a wide, varied, and creative community, not only of observers but also of instrument builders, operations staff and data/archive developers. All are necessary for a healthy field. We should encourage our agencies to adopt vigorous modest-mission programs, and to encourage open access to promote intellectual creativity. But some axes are almost certainly out of reach for Explorer-class missions. Most likely equaling or bettering Chandra angular resolution with larger area will require an Observatory-class, flagship, mission. While the technology is promising, the world-wide prospects for such a mission are grim. This is not merely the result of current economic woes, although they have brought the crisis to a head. Each generation of mission has to be an order of magnitude better than its predecessor in order to win funding. But to achieve this costs go up by a factor of a few each time. The progression: rockets - UHURU - Einstein - Chandra illustrates this clearly. The same exponentiation is evident in UV/visible astronomy and, perhaps, in Mars exploration. We have now hit the "funding wall" where each flagship mission costs so much that they pop into politicians notice. JWST is now a budget line item in the US, a precarious position previously held by the

  9. Association Between a Single General Anesthesia Exposure Before Age 36 Months and Neurocognitive Outcomes in Later Childhood.

    Science.gov (United States)

    Sun, Lena S; Li, Guohua; Miller, Tonya L K; Salorio, Cynthia; Byrne, Mary W; Bellinger, David C; Ing, Caleb; Park, Raymond; Radcliffe, Jerilynn; Hays, Stephen R; DiMaggio, Charles J; Cooper, Timothy J; Rauh, Virginia; Maxwell, Lynne G; Youn, Ahrim; McGowan, Francis X

    2016-06-07

    Exposure of young animals to commonly used anesthetics causes neurotoxicity including impaired neurocognitive function and abnormal behavior. The potential neurocognitive and behavioral effects of anesthesia exposure in young children are thus important to understand. To examine if a single anesthesia exposure in otherwise healthy young children was associated with impaired neurocognitive development and abnormal behavior in later childhood. Sibling-matched cohort study conducted between May 2009 and April 2015 at 4 university-based US pediatric tertiary care hospitals. The study cohort included sibling pairs within 36 months in age and currently 8 to 15 years old. The exposed siblings were healthy at surgery/anesthesia. Neurocognitive and behavior outcomes were prospectively assessed with retrospectively documented anesthesia exposure data. A single exposure to general anesthesia during inguinal hernia surgery in the exposed sibling and no anesthesia exposure in the unexposed sibling, before age 36 months. The primary outcome was global cognitive function (IQ). Secondary outcomes included domain-specific neurocognitive functions and behavior. A detailed neuropsychological battery assessed IQ and domain-specific neurocognitive functions. Parents completed validated, standardized reports of behavior. Among the 105 sibling pairs, the exposed siblings (mean age, 17.3 months at surgery/anesthesia; 9.5% female) and the unexposed siblings (44% female) had IQ testing at mean ages of 10.6 and 10.9 years, respectively. All exposed children received inhaled anesthetic agents, and anesthesia duration ranged from 20 to 240 minutes, with a median duration of 80 minutes. Mean IQ scores between exposed siblings (scores: full scale = 111; performance = 108; verbal = 111) and unexposed siblings (scores: full scale = 111; performance = 107; verbal = 111) were not statistically significantly different. Differences in mean IQ scores between sibling pairs were

  10. In utero bisphenol A exposure disrupts germ cell nest breakdown and reduces fertility with age in the mouse

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Wei, E-mail: weiwang2@illinois.edu; Hafner, Katlyn S., E-mail: katlynhafner@gmail.com; Flaws, Jodi A., E-mail: jflaws@illinois.edu

    2014-04-15

    Bisphenol A (BPA) is a known reproductive toxicant in rodents. However, the effects of in utero BPA exposure on early ovarian development and the consequences of such exposure on female reproduction in later reproductive life are unclear. Thus, we determined the effects of in utero BPA exposure during a critical developmental window on germ cell nest breakdown, a process required for establishment of the finite primordial follicle pool, and on female reproduction. Pregnant FVB mice (F0) were orally dosed daily with tocopherol-striped corn oil (vehicle), diethylstilbestrol (DES; 0.05 μg/kg, positive control), or BPA (0.5, 20, and 50 μg/kg) from gestational day 11 until birth. Ovarian morphology and gene expression profiles then were examined in F1 female offspring on postnatal day (PND) 4 and estrous cyclicity was examined daily after weaning for 30 days. F1 females were also subjected to breeding studies with untreated males at three to nine months. The results indicate that BPA inhibits germ cell nest breakdown via altering expression of selected apoptotic factors. BPA also significantly advances the age of first estrus, shortens the time that the females remain in estrus, and increases the time that the females remain in metestrus and diestrus compared to controls. Further, F1 females exposed to low doses of BPA exhibit various fertility problems and have a significantly higher percentage of dead pups compared to controls. These results indicate that in utero exposure to low doses of BPA during a critical ovarian developmental window interferes with early ovarian development and reduces fertility with age. - Highlights: • In utero BPA exposure inhibits germ cell nest breakdown in female mouse offspring. • In utero BPA exposure alters expression of apoptosis regulators in the ovaries of mouse offspring. • In utero BPA exposure advances first estrus age and alters cyclicity in mouse offspring. • In utero BPA exposure causes various fertility problems in

  11. In utero bisphenol A exposure disrupts germ cell nest breakdown and reduces fertility with age in the mouse

    International Nuclear Information System (INIS)

    Wang, Wei; Hafner, Katlyn S.; Flaws, Jodi A.

    2014-01-01

    Bisphenol A (BPA) is a known reproductive toxicant in rodents. However, the effects of in utero BPA exposure on early ovarian development and the consequences of such exposure on female reproduction in later reproductive life are unclear. Thus, we determined the effects of in utero BPA exposure during a critical developmental window on germ cell nest breakdown, a process required for establishment of the finite primordial follicle pool, and on female reproduction. Pregnant FVB mice (F0) were orally dosed daily with tocopherol-striped corn oil (vehicle), diethylstilbestrol (DES; 0.05 μg/kg, positive control), or BPA (0.5, 20, and 50 μg/kg) from gestational day 11 until birth. Ovarian morphology and gene expression profiles then were examined in F1 female offspring on postnatal day (PND) 4 and estrous cyclicity was examined daily after weaning for 30 days. F1 females were also subjected to breeding studies with untreated males at three to nine months. The results indicate that BPA inhibits germ cell nest breakdown via altering expression of selected apoptotic factors. BPA also significantly advances the age of first estrus, shortens the time that the females remain in estrus, and increases the time that the females remain in metestrus and diestrus compared to controls. Further, F1 females exposed to low doses of BPA exhibit various fertility problems and have a significantly higher percentage of dead pups compared to controls. These results indicate that in utero exposure to low doses of BPA during a critical ovarian developmental window interferes with early ovarian development and reduces fertility with age. - Highlights: • In utero BPA exposure inhibits germ cell nest breakdown in female mouse offspring. • In utero BPA exposure alters expression of apoptosis regulators in the ovaries of mouse offspring. • In utero BPA exposure advances first estrus age and alters cyclicity in mouse offspring. • In utero BPA exposure causes various fertility problems in

  12. Media Exposure in Low-Income Preschool-Aged Children Is Associated with Multiple Measures of Self-Regulatory Behavior.

    Science.gov (United States)

    Munzer, Tiffany G; Miller, Alison L; Peterson, Karen E; Brophy-Herb, Holly E; Horodynski, Mildred A; Contreras, Dawn; Sturza, Julie; Lumeng, Julie C; Radesky, Jenny

    2018-05-01

    Excessive screen media exposure in childhood is associated with parent-reported self-regulation difficulties. No studies have used laboratory-based or teacher-reported measures of child self-regulatory behaviors. This study examines cross-sectional associations between preschooler screen media exposure and multiple measures of self-regulatory behaviors. Preintervention data were used from 541 preschoolers in the Growing Healthy study, an obesity prevention trial (2011-2015). Screen media exposure was measured by daily screen media exposure (hr/d), television (TV) in the bedroom, frequency of background TV, and TV with meals (1 = rarely/never, 4 = frequently). Child self-regulatory behaviors were measured by the following: child ability to delay gratification, a standardized waiting paradigm; teacher-reported Social Competence and Behavior Evaluation; and parent-reported difficult temperament on the Child Behavior Questionnaire (CBQ). Multivariate regression analyses modeled screen media exposure predicting each self-regulatory measure, adjusting for child age, sex, parent age, education, marital status, income-to-needs ratio, number of adults in household, parent depressive symptoms, and sensitivity. Children were aged 4.1 years (SD = 0.5), parents were aged 29.6 years (SD = 6.8), 48% had high school education or less, and 67% were married. Daily screen media exposure and background TV were associated with weaker observed self-regulation (β: -10.30 seconds for each hr/d media, -12.63 seconds for 1-point increase, respectively). Background TV and TV with meals were associated with greater parent-reported difficult temperament (β: 0.04 and 0.05 CBQ, respectively, for 1-point increase). Greater screen media exposure had small but significant associations with weaker observed and parent-reported, but not teacher-reported, self-regulatory behaviors. Longitudinal studies are needed to determine the directionality of associations.

  13. Intercomparison of the medium energy primary standards for X-ray exposure of NPL and ENEA, Italy

    International Nuclear Information System (INIS)

    Moretti, C.J.; Heaton, J.A.; Laitano, R.F.; Toni, M.P.

    1991-04-01

    An intercomparison between the primary standards of exposure for medium energy X-rays held by the National Physical Laboratory (NPL) and ENEA in Italy is described. The intercomparison, using four different transfer chambers, took place at NPL in December 1989 and at ENEA during March 1990. Measurements were made at four therapy-level qualities, with half value layers of 0.15, 0.5, 1.0 and 2.5 mm Cu (nominal generating voltages of 100, 135, 180 and 250 kV respectively). At the 2.5 mm Cu HVL quality the primary standards were found to agree to within about 0.8%; for the other three qualities the chambers differed by no more than 0.3%. (author)

  14. Measurements of radio frequent cavity volt ages by X-ray spectrum measurements

    Directory of Open Access Journals (Sweden)

    Toprek Dragan

    2005-01-01

    Full Text Available This paper deals with X-ray spectrum measurement as a method for the measurement of radio frequent cavity voltage and the theory of X-ray spectrum calculation. Experimental results at 72 MHz for three different values of the radio frequent power of ACCEL K250 super conducting cyclotron are being presented.

  15. The effect of age at exposure on the inactivating mechanisms and relative contributions of key tumor suppressor genes in radiation-induced mouse T-cell lymphomas

    Energy Technology Data Exchange (ETDEWEB)

    Sunaoshi, Masaaki [Radiobiology for Children' s Health Program, Research Center for Radiation Protection, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba 263-8555 (Japan); Department of Biological Sciences, College of Science, Ibaraki University, Bunkyo 2-1-1, Mito, Ibaraki 310-8512 (Japan); Amasaki, Yoshiko; Hirano-Sakairi, Shinobu; Blyth, Benjamin J. [Radiobiology for Children' s Health Program, Research Center for Radiation Protection, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba 263-8555 (Japan); Morioka, Takamitsu [Radiobiology for Children' s Health Program, Research Center for Radiation Protection, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba 263-8555 (Japan); Radiation Effect Accumulation and Prevention Project, Fukushima Project Headquarters, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba 263-8555 (Japan); Kaminishi, Mutsumi [Radiobiology for Children' s Health Program, Research Center for Radiation Protection, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba 263-8555 (Japan); Shang, Yi [Radiation Effect Accumulation and Prevention Project, Fukushima Project Headquarters, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba 263-8555 (Japan); Nishimura, Mayumi; Shimada, Yoshiya [Radiobiology for Children' s Health Program, Research Center for Radiation Protection, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba 263-8555 (Japan); Radiation Effect Accumulation and Prevention Project, Fukushima Project Headquarters, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba 263-8555 (Japan); Tachibana, Akira [Department of Biological Sciences, College of Science, Ibaraki University, Bunkyo 2-1-1, Mito, Ibaraki 310-8512 (Japan); and others

    2015-09-15

    Highlights: • T-cell lymphoma incidence, latency and weight did not change with age at exposure. • Lymphomas had frequent loss of heterozygosity on chromosomes 4, 11 and 19. • These lesions targeted the Cdkn2a, Ikaros and Pten tumor suppressor genes. • Age at exposure may influence which tumor suppressor genes are lost in each tumor. • The mechanisms of tumor suppressor gene loss were different at each locus. - Abstract: Children are considered more sensitive to radiation-induced cancer than adults, yet any differences in genomic alterations associated with age-at-exposure and their underlying mechanisms remain unclear. We assessed genome-wide DNA copy number and mutation of key tumor suppressor genes in T-cell lymphomas arising after weekly irradiation of female B6C3F1 mice with 1.2 Gy X-rays for 4 consecutive weeks starting during infancy (1 week old), adolescence (4 weeks old) or as young adults (8 weeks old). Although T-cell lymphoma incidence was similar, loss of heterozygosity at Cdkn2a on chromosome 4 and at Ikaros on chromosome 11 was more frequent in the two older groups, while loss at the Pten locus on chromosome 19 was more frequent in the infant-irradiated group. Cdkn2a and Ikaros mutation/loss was a common feature of the young adult-irradiation group, with Ikaros frequently (50%) incurring multiple independent hits (including deletions and mutations) or suffering a single hit predicted to result in a dominant negative protein (such as those lacking exon 4, an isoform we have designated Ik12, which lacks two DNA binding zinc-finger domains). Conversely, Pten mutations were more frequent after early irradiation (60%) than after young adult-irradiation (30%). Homozygous Pten mutations occurred without DNA copy number change after irradiation starting in infancy, suggesting duplication of the mutated allele by chromosome mis-segregation or mitotic recombination. Our findings demonstrate that while deletions on chromosomes 4 and 11 affecting Cdkn2

  16. Effect of continuous exposure to very low dose rates of gamma rays on life span and neoplasia in mice

    International Nuclear Information System (INIS)

    Tanaka, I.B. III; Tanaka, Satoshi; Ichinohe, Kazuaki; Matsumoto, Tsuneya; Otsu, Hiroshi; Oghiso, Yoichi; Sato, Fumiaki; Matsushita, Satoru

    2008-01-01

    Late effects of continuous exposure to ionizing radiation are potential hazards to workers in radiation facilities as well as to the general public. In the recent years, low-dose-rate and low-dose effects have become a serious concern. Using a total of 4,000 mice, we studied the late biological effects of chronic exposure to low-dose-rate radiation on life span and neoplasia. Two thousand male and 2000 female 8-week-old specific pathogen free (SPF) B6C3F1 mice were randomly divided into 4 groups, one non-irradiated (control) and three irradiated. The irradiated groups were exposed to 137 Cs gamma rays at dose-rates of 21, 1.1 and 0.05 mGy day -1 for approximately 400 days with total doses equivalent to 8000, 400 and 20 mGy, respectively. All mice were kept under SPF conditions until natural death and pathological examination was performed to determine the cause of death. Statistical analyses showed that the life spans of mice of both sexes irradiated with 21 mGy day -1 (P -1 (P 86.7% of all deaths. Compared to the non-irradiated controls, incidences of lethal neoplasms were significantly increased for myeloid leukaemia and hemangiosarcoma in males, soft tissue neoplasms and malignant granulosa cell tumors in females exposed to 21 mGy day -1 . The number of multiple primary neoplasms per mouse was significantly increased in mice irradiated at 21 mGy day -1 . Our results suggest that life shortening in mice continuously exposed to low dose-rate gamma rays is due to early death from a variety of neoplasms and not from increased incidence of specific lethal neoplasms. (author)

  17. Sex-dependent Differences in Intestinal Tumorigenesis Induced in Apc1638N/+ Mice by Exposure to {gamma} Rays

    Energy Technology Data Exchange (ETDEWEB)

    Trani, Daniela [Department of Biochemistry and Molecular and Cellular Biology, Georgetown University, Washington, District of Columbia (United States); Lombardi Comprehensive Cancer Center, Georgetown University Medical Center, Washington, District of Columbia (United States); Maastricht Radiation Oncology (MaastRO) Lab, GROW-School for Oncology and Developmental Biology, University of Maastricht (Netherlands); Moon, Bo-Hyun [Department of Biochemistry and Molecular and Cellular Biology, Georgetown University, Washington, District of Columbia (United States); Lombardi Comprehensive Cancer Center, Georgetown University Medical Center, Washington, District of Columbia (United States); Kallakury, Bhaskar; Hartmann, Dan P. [Lombardi Comprehensive Cancer Center, Georgetown University Medical Center, Washington, District of Columbia (United States); Datta, Kamal [Department of Biochemistry and Molecular and Cellular Biology, Georgetown University, Washington, District of Columbia (United States); Lombardi Comprehensive Cancer Center, Georgetown University Medical Center, Washington, District of Columbia (United States); Fornace, Albert J., E-mail: af294@georgetown.edu [Department of Biochemistry and Molecular and Cellular Biology, Georgetown University, Washington, District of Columbia (United States); Lombardi Comprehensive Cancer Center, Georgetown University Medical Center, Washington, District of Columbia (United States); Center of Excellence in Genomic Medicine Research (CEGMR), King Abdulaziz University, Jeddah (Saudi Arabia)

    2013-01-01

    Purpose: The purpose of the present study was to assess the effect of 1 and 5 Gy radiation doses and to investigate the interplay of gender and radiation with regard to intestinal tumorigenesis in an adenomatous polyposis coli (APC) mutant mouse model. Methods and Materials: Apc1638N/+ female and male mice were exposed whole body to either 1 Gy or 5 Gy of {gamma} rays and euthanized when most of the treated mice became moribund. Small and large intestines were processed to determine tumor burden, distribution, and grade. Expression of proliferation marker Ki-67 and estrogen receptor (ER)-{alpha} were also assessed by immunohistochemistry. Results: We observed that, with both 1 Gy and 5 Gy of {gamma} rays, females displayed reduced susceptibility to radiation-induced intestinal tumorigenesis compared with males. As for radiation effect on small intestinal tumor progression, although no substantial differences were found in the relative frequency and degree of dysplasia of adenomas in irradiated animals compared with controls, invasive carcinomas were found in 1-Gy- and 5-Gy-irradiated animals. Radiation exposure was also shown to induce an increase in protein levels of proliferation marker Ki-67 and sex-hormone receptor ER-{alpha} in both non tumor mucosa and intestinal tumors from irradiated male mice. Conclusions: We observed important sex-dependent differences in susceptibility to radiation-induced intestinal tumorigenesis in Apc1638N/+ mutants. Furthermore, our data provide evidence that exposure to radiation doses as low as 1 Gy can induce a significant increase in intestinal tumor multiplicity as well as enhance tumor progression in vivo.

  18. Prime-time television exposure to high priority school-aged social-developmental issues.

    Science.gov (United States)

    Suzuki, Sherrie; Itano, Davin; Yamamoto, Loren G

    2008-03-01

    The purpose of this study is to quantify the material children and adolescents are exposed to while watching prime-time television so that school educators, health professionals, and parents can focus on issues of maximum exposure that must be addressed. Prime-time programming was recorded from 7 p.m. to 10 p.m. Hawaiian Standard Time daily for 2 weeks in July 2005. Recordings were then viewed to identify social behaviors of interest. Each hour on average, sex was referenced 1.8 times, drugs 0.6 times, tobacco 0.3 times, alcohol 2.4 times, and violence/crime 6.0 times per network. Messages advocating exercise, anti-drug advocacy, and anti-smoking advocacy were each shown 0.2 times per hour; while anti-alcohol advocacy was shown 0.1 times per hour. School educators, health professionals, and parents must recognize that prime-time television frequently exposes viewers to issues that are of critical importance to the health and social development of school-aged children and adolescents.

  19. Effect of Perinatal Lead Exposure on the Social Behaviour of Laboratory Mice Offspring at Adolescent Age

    International Nuclear Information System (INIS)

    AbuTaweel Qasim M; Ajarem Jamaan S

    2008-01-01

    Lead ( Pb ) was given to Swiss-Webster female mice at the concentrations of 0.1 and 0.2% ( w/v ) , containing 550 and 1100 ppm of lead respectively, in their drinking water. Treatment started from day 1 of pregnancy until day 15 postnatally . Thereafter, the dams were switched to plain tap water. After the weaning period ( 21 days ), all male offspring were isolated (one animal per cage) for 14 days, and the isolated male offspring were subjected to 'Standard Opponenttest' at the age of 36 days . the results of this test showed a significant and dose-dependent increase in the non-social behaviour , whereas such results showed a significant decline in the social behaviour including naso-genital and naso-nasal contact, number of fights, rear, wall rear and displacement activities of the Pb exposed young adult male offspring. The present perinatal Pb effects in the male offspring are possibly via in utero exposure and/or via mother's milk. (author)

  20. Hand X-ray in pediatric endocrinology: Skeletal age assessment and beyond

    Directory of Open Access Journals (Sweden)

    Vincenzo De Sanctis

    2014-01-01

    Full Text Available Skeletal age assessment (SAA is a clinical procedure which is used in determining the SA of children and adolescents. Bone development is influenced by a number of factors, including nutrition, hormonal secretions, and genetics. There are several factors to be borne in mind when using methods of assessing skeletal maturity. These include: Variability among methods, degree of variability in the estimation of skeletal maturation, sources of low accuracy, and dispersion of the values of skeletal maturation. Currently, the main clinical methods for SAA are the Greulich and Pyle (GP and Tanner and Whitehouse (TW methods. The GP method has the advantage of being quick and easy to use. A well-trained radiologist takes few minutes to determine the bone age (BA from a single hand radiograph. The method of TW, however, seems to be more reliable than the GP method. In recent years, the increasing speed in computer sciences and reduction of their cost has given the opportunity to create and use computerized BA estimation system. Despite the fact that the number of automated systems for BAA have increased, most are still within the experimental phase. The use of automated BA determination system, cleared for clinical use in Europe (BoneXpert, has been validated for various ethnicities and children with endocrine disorders. Ultrasound imaging has some limitations that include operator dependence, lower intra-rater and inter-rater reliability of assessment and difficulties with standardization of documentation and imaging transfer. Magnetic resonance imaging (MRI is noninvasive alternative tool for SA assessment in children. However, few studies have been reported on this topic, and further research is needed to evaluate the reliability and validity of MRI BAAs. In conclusion, at present radiographic methods for the assessment of BA remain the gold standards. Whatever method one adopts, it is essential to minimize the causes of imprecision by taking care to

  1. Normal rejoining of DNA strand breaks in ataxia telangiectasia fibroblast lines after low x-ray exposure

    International Nuclear Information System (INIS)

    Hariharan, P.V.; Eleczko, S.; Smith, B.P.; Paterson, M.C.

    1981-01-01

    The alkaline elution method was used to measure the enzymatic repair of x-ray-induced DNA strand breaks in skin fibroblasts derived from human subjects afflicted with ataxia telangiectasia (AT). Monolayer cultures of normal control and AT cell lines were exposed acutely to moderately lethal (250-rad) and highly lethal (1250-rad) doses of 250-kV x rays under aerobic conditions. Upon receiving 250 rad, the control fibroblasts from a clinically normal donor rejoined all detectable single-strand breaks (plus alkali-labile bonds) within 30 to 60 min of incubation. When challenged with 1250 rad the kinetics of strand rejoining by the normal control cells were biphasic. For both exposures, no significant difference in either the rate or the extent of strand rejoining was detected between the normal cell line (GM38) and three mutant cell lines (AT2BE, AT3BI, AT4BI) belonging to the three known genetic complementation groups in AT. It would thus appear that the enhanced radiosensitivity of cultured AT cells does not stem from faulty rejoining of radiogenic DNA strand breaks

  2. A comprehensive study of the energy absorption and exposure buildup factors of different bricks for gamma-rays shielding

    Directory of Open Access Journals (Sweden)

    M.I. Sayyed

    Full Text Available The present investigation has been performed on different bricks for the purpose of gamma-ray shielding. The values of the mass attenuation coefficient (µ/ρ, energy absorption buildup factor (EABF and exposure buildup factor (EBF were determined and utilized to assess the shielding effectiveness of the bricks under investigation. The mass attenuation coefficients of the selected bricks were calculated theoretically using WinXcom program and compared with MCNPX code. Good agreement between WinXcom and MCNPX results was observed. Furthermore, the EABF and EBF have been discussed as functions of the incident photon energy and penetration depth. It has been found that the EABF and EBF values are very large in the intermediate energy region. The steel slag showed good shielding properties, consequently, this brick is eco-friendly and feasible compared with other types of bricks used for construction. The results in this work should be useful in the construction of effectual shielding against hazardous gamma-rays. Keywords: Brick, Mass attenuation coefficient, Buildup factor, G-P fitting, Radiation shielding

  3. Advertising exposure and use of e-cigarettes among female current and former tobacco users of childbearing age.

    Science.gov (United States)

    Ashford, Kristin; Rayens, Emily; Wiggins, Amanda T; Rayens, Mary Kay; Fallin, Amanda; Sayre, Molly Malany

    2017-09-01

    The study examined the relationship between exposure to e-cigarette advertising and e-cigarette use by pregnancy status, including use of flavored e-cigarette products, among women of childbearing age. A cross-sectional, correlational design was used. Female current or former tobacco users in Central and Eastern Kentucky, 18-45 years old (N = 194, 52% pregnant). Demographics, pregnancy status, cigarette and e-cigarette use, and exposure to e-cigarette advertising. Younger age, white non-Hispanic race, and greater exposure to e-cigarette advertising were associated with a higher likelihood of ever using e-cigarettes (p advertisements or information about e-cigarettes on social media, compared to those who used unflavored e-cigarettes only (p = .016). There is a link between advertising exposure and ever use of e-cigarettes. Pregnancy status is not significantly associated with ever use. Use of flavored e-cigarettes is associated with younger age. E-cigarette users with greater exposure to advertising on social media were more likely to use flavored products. © 2017 Wiley Periodicals, Inc.

  4. Contribution of renal X-ray examinations to the radiation exposure to the population

    International Nuclear Information System (INIS)

    Radtke, I.; Koenig, W.; Menzel, B.

    1978-01-01

    Measured values of the radiation exposure of patients by urography published in the literature are summarized and critically reviewed. The gonad dose to men, women and children has been determined in 6 series of measurements performed according to the recommendations of the Gesellschaft fuer Medizinische Radiologie. Altogether, the determination of the gonad dose based on 927 individual measurements, 230 of them intravaginally, on 226 patients. The surface dose has been determined from 335 measurements. With exact collimation and shielding values of 250 mR for men and 650 mR for women have been obtained as the most probable ones. For 350,000 urographs equally distributed to both sexes and performed under correct working conditions an average per capita dose of 9.2 mR would result. (author)

  5. Contribution of renal X-ray examinations to the radiation exposure to the population

    Energy Technology Data Exchange (ETDEWEB)

    Radtke, I [Staedtisches Klinikum Berlin-Buch (German Democratic Republic). Roentgendiagnostisches Zentrum; Angerstein, W [Forschungsinstitut fuer Tuberkulose und Lungenkrankheiten, Berlin (German Democratic Republic); Koenig, W; Menzel, B [Staatliches Amt fuer Atomsicherheit und Strahlenschutz, Berlin (German Democratic Republic)

    1978-04-02

    Measured values of the radiation exposure of patients by urography published in the literature are summarized and critically reviewed. The gonad dose to men, women and children has been determined in 6 series of measurements performed according to the recommendations of the Gesellschaft fuer Medizinische Radiologie. Altogether, the determination of the gonad dose based on 927 individual measurements, 230 of them intravaginally, on 226 patients. The surface dose has been determined from 335 measurements. With exact collimation and shielding values of 250 mR for men and 650 mR for women have been obtained as the most probable ones. For 350,000 urographs equally distributed to both sexes and performed under correct working conditions an average per capita dose of 9.2 mR would result.

  6. Hospital and clinic survey estimates of medical X-ray exposure in Hiroshima and Nagasaki, 2

    International Nuclear Information System (INIS)

    Antoku, Shigetoshi; Hoshi, Masaharu; Sawada, Shozo; Russell, W.J.

    1987-07-01

    The technical factors used during radiological examinations performed in Hiroshima and Nagasaki medical institutions were analyzed. The most frequently performed examination was chest radiography, followed by upper GI series. More than half the radiographic exposures were from upper GI series due to the many spot films made during fluoroscopy. Comparison of the present survey results with those of a previous one showed that relatively high kVp, low mAs and mA, and smaller field sizes are now more widely used. Though there have been decreased in fluoroscopy times and tube currents over the past 10 years, the numbers of spot films used have increased. Based on these technical factors, tables of organ doses from fluoroscopic examinations were compiled. (author)

  7. Exposure science in an age of rapidly changing climate: challenges and opportunities

    Science.gov (United States)

    LaKind, Judy S; Overpeck, Jonathan; Breysse, Patrick N; Backer, Lorrie; Richardson, Susan D; Sobus, Jon; Sapkota, Amir; Upperman, Crystal R; Jiang, Chengsheng; Beard, C Ben; Brunkard, J M; Bell, Jesse E; Harris, Ryan; Chretien, Jean-Paul; Peltier, Richard E; Chew, Ginger L; Blount, Benjamin C

    2016-01-01

    Climate change is anticipated to alter the production, use, release, and fate of environmental chemicals, likely leading to increased uncertainty in exposure and human health risk predictions. Exposure science provides a key connection between changes in climate and associated health outcomes. The theme of the 2015 Annual Meeting of the International Society of Exposure Science—Exposures in an Evolving Environment—brought this issue to the fore. By directing attention to questions that may affect society in profound ways, exposure scientists have an opportunity to conduct “consequential science”—doing science that matters, using our tools for the greater good and to answer key policy questions, and identifying causes leading to implementation of solutions. Understanding the implications of changing exposures on public health may be one of the most consequential areas of study in which exposure scientists could currently be engaged. In this paper, we use a series of case studies to identify exposure data gaps and research paths that will enable us to capture the information necessary for understanding climate change-related human exposures and consequent health impacts. We hope that paper will focus attention on under-developed areas of exposure science that will likely have broad implications for public health. PMID:27485992

  8. Adolescent context of exposure to prescription opioids and substance use disorder symptoms at age 35: A national longitudinal study

    Science.gov (United States)

    McCabe, Sean Esteban; Veliz, Philip; Schulenberg, John E.

    2016-01-01

    The objective of this study was to examine the association of context of prescription opioid exposure (i.e., medical and/or nonmedical) in adolescence with the subsequent risk of nonmedical use of prescription opioids (NMUPO) and substance use disorder (SUD) symptoms at age 35. Multiple cohorts of nationally representative probability samples of U.S. high school seniors (n = 4072) were surveyed via self-administered questionnaires and followed longitudinally from adolescence (modal age 18, graduating classes 1976–1996) to age 35 (1993–2013). Main outcome measures were past-year NMUPO and SUD symptoms. The medical and nonmedical use of prescription opioids during adolescence was significantly associated with NMUPO at age 35. Relative to no prescription opioid exposure, medical use of prescription opioids without any history of NMUPO during adolescence was not associated with SUD symptoms at age 35. In contrast, compared with no prescription opioid exposure during adolescence, the adjusted odds ratios (AORs) associated with SUD symptoms at age 35 were greater among those with a history of both medical use of prescription opioids and NMUPO during adolescence, AOR = 1.49 (95% confidence interval [CI], 1.13–1.97); and among those who reported NMUPO only, AOR = 2.61 (95% CI, 1.88–3.61). The findings indicate medical use of prescription opioids without any history of NMUPO in adolescence is not associated with SUD symptoms at age 35 while any NMUPO in adolescence predicts SUD symptoms at age 35. Screening instruments and preventative intervention programs to reduce NMUPO and SUDs must account for the context associated with prescription opioid exposure during adolescence. PMID:27227693

  9. New exposure ages for the Last Glacial Cycle in the Sanabria Lake region (northwestern Spain)

    Science.gov (United States)

    Rodríguez-Rodríguez, Laura; Jiménez-Sánchez, Montserrat; Domínguez-Cuesta, María Jose; Rinterknecht, Vincent; Pallàs, Raimon; Braucher, Régis; Bourlès, Didier; Valero-Garcés, Blas

    2013-04-01

    The Sanabria Lake region is located in the Trevinca Massif, a mid-latitude mountain area up to 2128 m asl in the northwest corner of the Iberian Peninsula (42oN 6oW). An ice cap glaciation took place during the Last Glacial Cycle in this massif, with an equilibrium line altitude of 1687 m for the Tera glacial outlet at its local maximum (Cowton et al., 2009). A well preserved glacial sequence occurs on an area of 45 km2 around the present Sanabria Lake (1000 m asl) and is composed by lateral and end moraines in close relationship with glaciolacustrine deposits. This sequence shows the ice snout oscillations of the former Tera glacier during the Last Glacial Cycle and offers a good opportunity to compare radiocarbon and OSL- based chronological models with new cosmogenic isotope dates. The new dataset of 10Be exposure ages presented here for the Sanabria Lake moraines is based on measurements conducted on 23 boulders and is compared with previous radiocarbon and OSL data conducted on ice related deposits (Pérez-Alberti et al., 2011; Rodríguez-Rodríguez et al., 2011). Our results are coherent with the available deglaciation radiocarbon chronology, and support a last deglaciation origin for the whole set of end moraines that are downstream the Sanabria Lake (19.2 - 15.7 10Be ka). Discrepancies between results of the different dating methods concern the timing of the local glacial maximum, with the cosmogenic exposure method always yielding the youngest minimum ages. As proposed to explain similar observations made elsewhere (Palacios et al., 2012), reconciling the ages from different dating methods would imply the occurrence of two glacial advances close enough in extent to generate an overlapping polygenic moraine. Cowton, T., Hughes, P.D., Gibbard, P.L., 2009. Palaeoglaciation of Parque Natural Lago de Sanabria, northwest Spain. Geomorphology 108, 282-291. Rodríguez-Rodríguez, L., Jiménez-Sánchez, M., Domínguez-Cuesta, M.J., Rico, M.T., Valero-Garcés, B

  10. Establishment and verification of dose-response curve of chromosomal aberrations after exposure to very high dose γ-ray

    International Nuclear Information System (INIS)

    Chen Ying; Luo Yisheng; Cao Zhenshan; Liu Xiulin

    2006-01-01

    To estimate accurately biological dose of the victims exposed to high dose, the dose-response curves of chromosome aberration induced by 6-22 Gy 60 Co γ-ray were established. Human peripheral blood in vitro was irradiated, then lymphocytes were concentrated, cultured 52h, 68h and 72h and harvested. The frequencies of dicentrics (multi-centrics) and rings were counted and compared between different culture times. The dose-response curves and equations were established, as well as verified with high dose exposure accidents. The experiment showed that the culture time should be prolonged properly after high dose exposure, and no significant differences were observed between 52-72h culture. The dose-response curve of 6-22 Gy fitted to linear-square model Y=-2.269 + 0.776D - 7.868 x 10 -3 D 2 and is reliable through verification of the accident dose estimations. In this study, the dose-response curve and equation of chromosome dic + r after 6-22 Gy high dose irradiation were established firstly, and exact dose estimation can be achieved according to it. (authors)

  11. Age-at-exposure effects on risk estimates for non-cancer mortality in the Japanese atomic bomb survivors

    International Nuclear Information System (INIS)

    Zhang Wei; Muirhead, Colin R; Hunter, Nezahat

    2005-01-01

    Statistically significant increases in non-cancer disease mortality with radiation dose have been observed among survivors of the atomic bombings of Hiroshima and Nagasaki. The increasing trends arise particularly for diseases of the circulatory, digestive, and respiratory systems. Rates for survivors exposed to a dose of 1 Sv are elevated by about 10%, a smaller relative increase than that for cancer. The aetiology of this increased risk is not yet understood. Neither animal nor human studies have found clear evidence for excess non-cancer mortality at the lower range of doses received by A-bomb survivors. In this paper, we examine the age and time patterns of excess risks in the A-bomb survivors. The results suggest that the excess relative risk of non-cancer disease mortality might be highest for exposure at ages 30-49 years, and that those exposed at ages 0-29 years might have a very low excess relative risk compared with those exposed at older ages. The differences in excess relative risk for different age-at-exposure groups imply that the dose response relationships for non-cancer disease mortality need to be modelled with adjustment for age-at-exposure

  12. Evolution of phenolic compounds and astringency during aging of red wine: effect of oxygen exposure before and after bottling.

    Science.gov (United States)

    Gambuti, Angelita; Rinaldi, Alessandra; Ugliano, Maurizio; Moio, Luigi

    2013-02-27

    The aim of this study was to evaluate the effect of oxygen exposure of red wine, before (micro-oxygenation) and after (nano-oxygenation) bottling, on the phenolic composition and astringency of wine. The astringency was evaluated by sensory analysis and by a method based on the SDS-PAGE of salivary proteins after reaction of saliva with wine (SPI, saliva precipitation index). Micro-oxygenation caused a stabilization of color, but this effect disappeared after long aging. For the wine with the lower pH a decrease of wine astringency and SPI was observed 42 months after micro-oxygenation. Oxygen ingress through the closure postbottling was positively correlated with the decrease of SPI. Therefore, the astringency and reactivity of wines toward salivary proteins of a bottled red wine can be modulated by controlled oxygen exposure during aging. For both experiments the effect of oxygen exposure depended on wine composition.

  13. Media Exposure, Body Dissatisfaction, and Disordered Eating in Middle-Aged Women: A Test of the Sociocultural Model of Disordered Eating

    Science.gov (United States)

    Slevec, Julie; Tiggemann, Marika

    2011-01-01

    The primary aim of our study was to examine the influence of media exposure on body dissatisfaction and disordered eating in middle-aged women. A sample of 101 women, aged between 35 and 55 years, completed questionnaire measures of media exposure, thin-ideal internalization, social comparison, appearance investment, aging anxiety, body…

  14. Staff and patient exposure to X-ray radiation during cardiac procedures

    International Nuclear Information System (INIS)

    Jankowski, J.; Papierz, D.; Domienik, J.; Kacprzyk, J.; Tybor-Czerwinska, M.; Werduch, A.

    2008-01-01

    The aim of this study was to define and compare staff and patient doses during the most common types of cardiac procedures. The influence of operators' technique and quality of X-ray unit in use on doses received by the staff and patients was investigated. The study was conduced in two independent hemodynamic rooms (I and II). The doses to hand for medical staff (operators and nurses) were monitored. For hand dose assessment, ring thermoluminescent dosimeters were used. Regarding patient dosimetry, dose-area product was collected for selected procedures. The monthly hand doses ranged from 0.4 mSv to 41.2 mSv in room I and from 0.1 to 8.95 mSv in room II. On the basis of the above measurements, the annual doses were estimated. The maximum annual hand doses for the operator and for the nurse in room I were 232.8 mSv/year and 11.5 mSv/year and in room II - 29.8 mSv/year and 14.1 mSv/year, respectively. Additionally, to compare the doses received by the particular medical operators, the doses were normalized to the total workload. Hand dose per procedure ranged from 109 to 614 μSv/procedure and were significantly larger in room I. The typical DAP values (median) recorded for the CA and CA+PTCA procedures were 55 Gy/cm 2 and 171 Gy/cm 2 in room I and 35 Gy/cm 2 and 87 Gy/cm 2 in the room II, respectively. As a result of this survey, the impact of medical operator's experience as well as technique and quality of available X-ray units on doses received by staff and patients has been proven. On the basis of the above results, the special need for monitoring hand doses for medical staff, apart from the effective dose, has been recognized. (author)

  15. Prenatal famine exposure and adult mortality from cancer, cardiovascular disease, and other causes through age 63 years

    NARCIS (Netherlands)

    Ekamper, P.; van Poppel, F.W.A.; Stein, A.D.; Bijwaard, G.E.; Lumey, L.H.

    2015-01-01

    Nutritional conditions in early life may affect adult health, but prior studies of mortality have been limited to small samples. We evaluated the relationship between pre-/perinatal famine exposure during the Dutch Hunger Winter of 1944–1945 and mortality through age 63 years among 41,096 men born

  16. Language and Preliteracy Skills in Bilinguals and Monolinguals at Preschool Age: Effects of Exposure to Richly Inflected Speech from Birth

    Science.gov (United States)

    Silven, Maarit; Rubinov, Evgenia

    2010-01-01

    Language proficiency before school entry has proven to be a powerful predictor of literacy development. This longitudinal study examined how simultaneous exposure to two richly inflected languages from birth contributes to the development of language-related literacy precursors at preschool age compared to peers exposed to one language. The…

  17. Reported exposure and emotional reactivity to daily stressors: the roles of adult age and global perceived stress.

    Science.gov (United States)

    Stawski, Robert S; Sliwinski, Martin J; Almeida, David M; Smyth, Joshua M

    2008-03-01

    A central goal of daily stress research is to identify resilience and vulnerability factors associated with exposure and reactivity to daily stressors. The present study examined how age differences and global perceptions of stress relate to exposure and emotional reactivity to daily stressors. Sixty-seven younger (M age = 20) and 116 older (M age = 80) adults completed a daily stress diary and measures of positive and negative affect on 6 days over a 14-day period. Participants also completed a measure of global perceived stress. Results revealed that reported exposure to daily stressors is reduced in old age but that emotional reactivity to daily stressors did not differ between younger and older adults. Global perceived stress was associated with greater reported exposure to daily stressors in older adults and greater stress-related increases in negative affect in younger adults. Furthermore, across days on which daily stressors were reported, intraindividual variability in the number and severity of stressors reported was associated with increased negative affect, but only among younger adults. (c) 2008 APA, all rights reserved.

  18. Age of Bilingual Exposure Is Related to the Contribution of Phonological and Semantic Knowledge to Successful Reading Development

    Science.gov (United States)

    Jasinska, Kaja K.; Petitto, Laura-Ann

    2018-01-01

    Bilingual children's reading as a function of age of first bilingual language exposure (AoE) was examined. Bilingual (varied AoE) and monolingual children (N = 421) were compared in their English language and reading abilities (6-10 years) using phonological awareness, semantic knowledge, and reading tasks. Structural equation modeling was applied…

  19. Occupational pesticide exposure in early pregnancy associated with sex-specific neurobehavioral deficits in the children at school age

    DEFF Research Database (Denmark)

    Andersen, Helle Raun; Debes, Frodi; Wohlfahrt-Veje, Christine

    2015-01-01

    categorized as occupationally exposed to pesticides were moved to unexposed work functions or went on paid leave, while women without any exposure were considered unexposed controls. Of the resulting birth cohort of 203 children, 133 (65%) were examined at age 6 to 11years together with 44 newly recruited...

  20. Summary Report of a Peer Involvement Workshop on the Development of An Exposure Factors Handbook for the Aging

    Science.gov (United States)

    EPA has released the final workshop report, Summary Report of a Peer Involvement Workshop on the Development of an Exposure Factors Handbook for the Aging. This report provides an overview of a meeting held February 14-15, 2007 which was organized to discuss factors affec...

  1. Implications of 36Cl exposure ages from Skye, northwest Scotland for the timing of ice stream deglaciation and deglacial ice dynamics

    Science.gov (United States)

    Small, David; Rinterknecht, Vincent; Austin, William E. N.; Bates, Richard; Benn, Douglas I.; Scourse, James D.; Bourlès, Didier L.; Hibbert, Fiona D.

    2016-10-01

    Geochronological constraints on the deglaciation of former marine based ice streams provide information on the rates and modes by which marine based ice sheets have responded to external forcing factors such as climate change. This paper presents new 36Cl cosmic ray exposure dating from boulders located on two moraines (Glen Brittle and Loch Scavaig) in southern Skye, northwest Scotland. Ages from the Glen Brittle moraines constrain deglaciation of a major marine terminating ice stream, the Barra-Donegal Ice Stream that drained the former British-Irish Ice Sheet, depending on choice of production method and scaling model this occurred 19.9 ± 1.5-17.6 ± 1.3 ka ago. We compare this timing of deglaciation to existing geochronological data and changes in a variety of potential forcing factors constrained through proxy records and numerical models to determine what deglaciation age is most consistent with existing evidence. Another small section of moraine, the Scavaig moraine, is traced offshore through multibeam swath-bathymetry and interpreted as delimiting a later stillstand/readvance stage following ice stream deglaciation. Additional cosmic ray exposure dating from the onshore portion of this moraine indicate that it was deposited 16.3 ± 1.3-15.2 ± 0.9 ka ago. When calculated using the most up-to-date scaling scheme this time of deposition is, within uncertainty, the same as the timing of a widely identified readvance, the Wester Ross Readvance, observed elsewhere in northwest Scotland. This extends the area over which this readvance has potentially occurred, reinforcing the view that it was climatically forced.

  2. Estimated exposures to perfluorinated compounds in infancy predict attenuated vaccine antibody concentrations at age 5-years

    DEFF Research Database (Denmark)

    Grandjean, Philippe; Heilmann, Carsten; Weihe, Pal

    2017-01-01

    Perfluorinated alkylate substances (PFASs) are highly persistent and may cause immunotoxic effects. PFAS-associated attenuated antibody responses to childhood vaccines may be affected by PFAS exposures during infancy, where breastfeeding adds to PFAS exposures. Of 490 members of a Faroese birth...... the notion that the developing adaptive immune system is particularly vulnerable to immunotoxicity during infancy. This vulnerability appears to be the greatest during the first 6 months after birth, where PFAS exposures are affected by breast-feeding....

  3. Dicentric yields induced in rabbit blood lymphocytes after exposure in vitro to X-rays

    International Nuclear Information System (INIS)

    Inoue, Yoshinori

    1995-06-01

    For the purpose of biological dosimetry, it is essential to establish the relationship between dicentric yields and absorbed doses. The present experiment was carried out to obtain data for rabbit lymphocytes as a reference for this relationship. As data at low dose level are scanty, rabbit lymphocytes were exposed to various doses, especially below 0.5 Gy, of 150 kVp X-rays and analysed at their first mitotic division for dicentric yields. The yields at high dose level were compared with data reported by other authors. The linear-quadratic equation, which is generally accepted, for the dose-response relationship was obtained by the iteratively reweighted least squares method. However, as the present experiment result showed that the dose-response relationship at low dose-levels was likely to be linear, a dose-response line was calculated by the linear regression analysis. As the result of the chi-square tests, it was found that the dicentric yield was better fitted to the linear model at low doses below 0.5 Gy than the linear quadratic model. (author)

  4. Degradation of Albumin on Plasma-Treated Polystyrene by Soft X-ray Exposure

    Directory of Open Access Journals (Sweden)

    Nina Recek

    2016-06-01

    Full Text Available Thin films of human serum albumin (HSA were immobilized on polystyrene (PS substrates previously functionalized either with polar or nonpolar functional groups. The functionalization was performed by treatment with cold gaseous plasma created in pure oxygen and tetrafluoromethane (CF4 plasmas, respectively. Samples were examined with soft X-rays in the photon energy range of 520 to 710 eV in the ANTARES beam line at SOLEIL Synchrotron. NEXAFS spectra of O K-edge and F K-edge were collected at different spots of the sample, and measurements at each spot were repeated many times. A strong degradation of the HSA protein was observed. The weakly irradiated samples exhibited strong absorption at 531.5 eV associated with the O 1s→π*amide transitions, and a broad non distinctive peak at 540 eV was attributed to the O 1s→σ*C–O transitions. Both peaks decreased with increasing irradiation time until they were completely replaced by a broad non-distinctive peak at around 532 eV, indicating the destruction of the original protein conformation. The shortage of the amide groups indicated breakage of the peptide bonds.

  5. Study of the contribution of X-ray and gamma photons to the measured exposure dose

    International Nuclear Information System (INIS)

    Andriampanarivo, H.L.H.

    2000-01-01

    The aim of this work was to study the contribution of X-rays and gamma radiation to the measured dose in the city of Antananarivo. The annual indoor absorbed dose was studied as well. Measurements were carried out in twelve sites, namely public schools and churches. The mean dose rate lies between (0.34±0.03)μSv/h and (0.38±0.04)μSv/h for most of the sites. Two of them showed values between (0.40±0.04)μSv/h and (0.30±0.03)μSv/h. Mean indoor dose rate is of (0.36±0.04)μSv/h and the annual absorbed dose is (3.16±0.32)mSv/person. Indoor measurements showed mean integral values ranging from (277.22±0,22)cps to (733.66±0,37)cps. The lowest mean count rate is (277.22±0,22)cps, measured in the AMARO site, whereas the highest are (733,66±0,37)cps, (697,81±0,36)cps and (689,32±0,36)cps measured in ALO0 , AKELY, and MASINA respectively. [fr

  6. Cosmic ray production curves below reworking zones

    International Nuclear Information System (INIS)

    Blanford, G.E.

    1980-01-01

    A method is presented for calculating cosmic ray production profiles below reworking zones. The method uses an input reworking depth determined from data such as signatures in the depth profile of ferromagnetic resonance intensity and input cosmic ray production profiles for an undisturbed surface. Reworking histories are simulated using Monte Carlo techniques, and depth profiles are used to determine cosmic ray exposure age limits with a specified probability. It is shown that the track density profiles predict cosmic ray exposure ages in lunar cores that are consistent with values determined by other methods. Results applied to neutron fluence and spallation rare gases eliminate the use of reworking depth as an adjustable parameter and give cosmic ray exposure ages that are compatible with each other

  7. Study of the separate exposure method for bootstrap sensitometry on X-ray cine film

    International Nuclear Information System (INIS)

    Matsuda, Eiji; Sanada, Taizo; Hitomi, Go; Kakuba, Koki; Kangai, Yoshiharu; Ishii, Koushi

    1997-01-01

    We developed a new method for bootstrap sensitometry that obtained the characteristic curve from a wide range, with a smaller number of aluminum steps than the conventional bootstrap method. In this method, the density-density curve was obtained from standard and multiplied exposures to the aluminum step wedge and used for bootstrap manipulation. The curve was acquired from two regions separated and added together, e.g., lower and higher photographic density regions. In this study, we evaluated the usefulness of a new cinefluorography method in comparison with N.D. filter sensitometry. The shape of the characteristic curve and the gradient curve obtained with the new method were highly similar to that obtained with N.D. filter sensitometry. Also, the average gradient obtained with the new bootstrap sensitometry method was not significantly different from that obtained by the N.D. filter method. The study revealed that the reliability of the characteristic curve was improved by increasing the measured value used to calculate the density-density curve. This new method was useful for obtaining a characteristic curve with a sufficient density range, and the results suggested that this new method could be applied to specific systems to which the conventional bootstrap method is not applicable. (author)

  8. Association between prenatal polychlorinated biphenyl exposure and obesity development at ages 5 and 7 y

    DEFF Research Database (Denmark)

    Tang-Péronard, Jeanett L; Heitmann, Berit L; Andersen, Helle R

    2014-01-01

    Chemicals with endocrine-disrupting abilities may act as obesogens and interfere with the body's natural weight-control mechanisms, especially if exposure occurs during prenatal life.......Chemicals with endocrine-disrupting abilities may act as obesogens and interfere with the body's natural weight-control mechanisms, especially if exposure occurs during prenatal life....

  9. Phenotypic and Functional Changes Induced in Hematopoietic Stem/Progenitor Cells After Gamma-Ray Radiation Exposure

    Energy Technology Data Exchange (ETDEWEB)

    Simonnet, A.J.; Nehme, J.; Leboulch, Ph.; Tronik-Le Roux, D. [Institute of Emerging Diseases and Innovative Therapies, Functional Bioengineering Laboratory, Commissariat a l' Energie Atomique (CEA), Evry (France); Simonnet, A.J.; Nehme, J.; Leboulch, Ph.; Tronik-Le Roux, D. [Institut National de la Sante et de la Recherche Medicale (INSERM) U733 (Unite Mixte de Recherche) - UMR INSERM CEA Paris XI (France); Vaigot, P. [Institute of Cellular and Molecular Radiation Biology, Department of Genetic Instability, Recombination and Repair, Commissariat a l' Energie Atomique, Fontenay-aux-Roses (France); Vaigot, P. [UMR 217, UMR-CEA-Centre National de la Recherche Scientifique (France); Barroca, V. [Laboratory of Gametogenesis, Apoptosis, Genotoxicity, Institute of Cellular and Molecular Radiation Biology, Commissariat a l' Energie Atomique, Fontenay-aux-Roses (France); Barroca, V. [Institut National de la Sante et de la Recherche Medicale U566 - UMR INSERM-CEA-PARIS VII (France); Leboulch, Ph. [Genetics Division, Brigham and Women' s Hospital and Harvard Medical School, Boston, Massachusetts (US)

    2009-07-01

    Ionizing radiation (IR) exposure causes rapid and acute bone marrow (BM) suppression that is reversible for nonlethal doses. Evidence is accumulating that IR can also provoke long-lasting residual hematopoietic injury. To better understand these effects, we analyzed phenotypic and functional changes in the stem/progenitor compartment of irradiated mice over a 10-week period. We found that hematopoietic stem cells (HSCs) identified by their repopulating ability continued to segregate within the Hoechst dye excluding 'side population (SP)' early after IR exposure. However, transient phenotypic changes were observed within this cell population: Sca-1 (S) and c-Kit (K) expression levels were increased and severely reduced, respectively, with a concurrent increase in the proportion of SPSK cells positive for established indicators of the presence of HSCs: CD150 and CD105. Ten weeks after IR exposure, expression of Sca-1 and c-Kit at the SP cell surface returned to control levels, and BM cellularity of irradiated mice was restored. However, the c-Kit{sup +}Sca-1{sup +}Lin{sup -/low} (KSL) stem/progenitor compartment displayed major phenotypic modifications, including an increase and a severe decrease in the frequencies of CD150{sup +}Flk2{sup -} and CD150{sup -}Flk2{sup +} cells, respectively. CD150{sup +} KSL cells also showed impaired reconstituting ability, an increased tendency to apoptosis, and accrued DNA damage. Finally, 15 weeks after exposure, irradiated mice, but not age matched controls, allowed engraftment and significant hematopoietic contribution from transplanted con-genic HSCs without additional host conditioning. These results provide novel insight in our understanding of immediate and delayed IR-induced hematopoietic injury and highlight similarities between HSCs of young irradiated and old mice. (authors)

  10. Phenotypic and Functional Changes Induced in Hematopoietic Stem/Progenitor Cells After Gamma-Ray Radiation Exposure

    International Nuclear Information System (INIS)

    Simonnet, A.J.; Nehme, J.; Leboulch, Ph.; Tronik-Le Roux, D.; Simonnet, A.J.; Nehme, J.; Leboulch, Ph.; Tronik-Le Roux, D.; Vaigot, P.; Vaigot, P.; Barroca, V.; Barroca, V.; Leboulch, Ph.

    2009-01-01

    Ionizing radiation (IR) exposure causes rapid and acute bone marrow (BM) suppression that is reversible for nonlethal doses. Evidence is accumulating that IR can also provoke long-lasting residual hematopoietic injury. To better understand these effects, we analyzed phenotypic and functional changes in the stem/progenitor compartment of irradiated mice over a 10-week period. We found that hematopoietic stem cells (HSCs) identified by their repopulating ability continued to segregate within the Hoechst dye excluding 'side population (SP)' early after IR exposure. However, transient phenotypic changes were observed within this cell population: Sca-1 (S) and c-Kit (K) expression levels were increased and severely reduced, respectively, with a concurrent increase in the proportion of SPSK cells positive for established indicators of the presence of HSCs: CD150 and CD105. Ten weeks after IR exposure, expression of Sca-1 and c-Kit at the SP cell surface returned to control levels, and BM cellularity of irradiated mice was restored. However, the c-Kit + Sca-1 + Lin -/low (KSL) stem/progenitor compartment displayed major phenotypic modifications, including an increase and a severe decrease in the frequencies of CD150 + Flk2 - and CD150 - Flk2 + cells, respectively. CD150 + KSL cells also showed impaired reconstituting ability, an increased tendency to apoptosis, and accrued DNA damage. Finally, 15 weeks after exposure, irradiated mice, but not age matched controls, allowed engraftment and significant hematopoietic contribution from transplanted con-genic HSCs without additional host conditioning. These results provide novel insight in our understanding of immediate and delayed IR-induced hematopoietic injury and highlight similarities between HSCs of young irradiated and old mice. (authors)

  11. Neck x-ray

    Science.gov (United States)

    X-ray - neck; Cervical spine x-ray; Lateral neck x-ray ... There is low radiation exposure. X-rays are monitored so that the lowest amount of radiation is used to produce the image. Pregnant women and ...

  12. Low dose prenatal alcohol exposure does not impair spatial learning and memory in two tests in adult and aged rats.

    Directory of Open Access Journals (Sweden)

    Carlie L Cullen

    Full Text Available Consumption of alcohol during pregnancy can have detrimental impacts on the developing hippocampus, which can lead to deficits in learning and memory function. Although high levels of alcohol exposure can lead to severe deficits, there is a lack of research examining the effects of low levels of exposure. This study used a rat model to determine if prenatal exposure to chronic low dose ethanol would result in deficits in learning and memory performance and if this was associated with morphological changes within the hippocampus. Sprague Dawley rats were fed a liquid diet containing 6% (vol/vol ethanol (EtOH or an isocaloric control diet throughout gestation. Male and Female offspring underwent behavioural testing at 8 (Adult or 15 months (Aged of age. Brains from these animals were collected for stereological analysis of pyramidal neuron number and dendritic morphology within the CA1 and CA3 regions of the dorsal hippocampus. Prenatal ethanol exposed animals did not differ in spatial learning or memory performance in the Morris water maze or Y maze tasks compared to Control offspring. There was no effect of prenatal ethanol exposure on pyramidal cell number or density within the dorsal hippocampus. Overall, this study indicates that chronic low dose prenatal ethanol exposure in this model does not have long term detrimental effects on pyramidal cells within the dorsal hippocampus or impair spatial learning and memory performance.

  13. Attitudes of Veterinary Teaching Staff and Exposure of Veterinary Students to Early-Age Desexing, with Review of Current Early-Age Desexing Literature.

    Science.gov (United States)

    Jupe, Alannah; Rand, Jacquie; Morton, John; Fleming, Sophie

    2017-12-25

    Approximately 50% of cats admitted to Australian shelters are kittens, and 26% of dogs are puppies, and, particularly for cats, euthanasia rates are often high. Cats can be pregnant by 4 months of age, yet the traditional desexing age is 5-6 months, and studies in Australasia and Nth America reveal that only a minority of veterinarians routinely perform early age desexing (EAD) of cats or dogs, suggesting they are not graduating with these skills. This study aimed to describe the attitudes of veterinary teaching staff in Australian and New Zealand universities towards EAD, and to determine if these changed from 2008 to 2015. It also aimed to identify students' practical exposure to EAD. Most (64%) of the 25 participants in 2015 did not advocate EAD in their teaching and, in their personal opinion, only 32% advocated it for cats. Concerns related to EAD cited by staff included anesthetic risk, orthopedic problems, hypoglycemia, and, in female dogs, urinary incontinence. Those who advocated EAD cited benefits of population control, ease of surgery and behavioral benefits. Only three of the eight universities provided a majority of students with an opportunity to gain exposure to EAD procedures before graduation, and in two of these, most students had an opportunity to perform EAD. In conclusion, most veterinary students in Australia and New Zealand are not graduating with the knowledge or skills to perform EAD, and have little opportunity while at university to gain practical exposure. Welfare agencies could partner with universities to enable students to experience EAD.

  14. Maintaining radiation exposures as low as reasonably achievable (ALARA) for dental personnel operating portable hand-held x-ray equipment.

    Science.gov (United States)

    McGiff, Thomas J; Danforth, Robert A; Herschaft, Edward E

    2012-08-01

    Clinical experience indicates that newly available portable hand-held x-ray units provide advantages compared to traditional fixed properly installed and operated x-ray units in dental radiography. However, concern that hand-held x-ray units produce higher operator doses than fixed x-ray units has caused regulatory agencies to mandate requirements for use of hand-held units that go beyond those recommended by the manufacturer and can discourage the use of this technology. To assess the need for additional requirements, a hand-held x-ray unit and a pair of manikins were used to measure the dose to a simulated operator under two conditions: exposures made according to the manufacturer's recommendations and exposures made according to manufacturer's recommendation except for the removal of the x-ray unit's protective backscatter shield. Dose to the simulated operator was determined using an array of personal dosimeters and a pair of pressurized ion chambers. The results indicate that the dose to an operator of this equipment will be less than 0.6 mSv y⁻¹ if the device is used according to the manufacturer's recommendations. This suggests that doses to properly trained operators of well-designed, hand-held dental x-ray units will be below 1.0 mSv y⁻¹ (2% of the annual occupational dose limit) even if additional no additional operational requirements are established by regulatory agencies. This level of annual dose is similar to those reported as typical dental personnel using fixed x-ray units and appears to satisfy the ALARA principal for this class of occupational exposures.

  15. Assessment of trace element concentration distribution in human placenta by wavelength dispersive X-ray fluorescence: Effect of neonate weight and maternal age

    International Nuclear Information System (INIS)

    Ozdemir, Yueksel; Boerekci, Buenyamin; Levet, Aytac; Kurudirek, Murat

    2009-01-01

    Trace element status in human placenta is dependent on maternal-neonatal characteristics. This work was undertaken to investigate the correlation between essential trace element concentrations in the placenta and maternal-neonatal characteristics. Placenta samples were collected from total 61 healthy mothers at gestation between 37 and 41 weeks. These samples were investigated with the restriction that the mother's age was 20-40 years old and the neonate's weight was 1-4 kg. Percent concentrations of trace elements were determined using wavelength dispersive X-ray fluorescence (WDXRF). The placenta samples were prepared and analyzed without exposure to any chemical treatment. Concentrations of Fe, Cu and Zn in placenta tissues were found statistically to vary corresponding to the age of the mother and weight of the neonate. In the subjects, the concentration of Fe and Cu were increased in heavier neonates (p<0.05) and the concentration of Zn was increased with increasing mother age (p<0.05). Consequently, the Fe, Cu and Zn elements appear to have interactive connections in human placenta.

  16. Prenatal Fluoride Exposure and Cognitive Outcomes in Children at 4 and 6-12 Years of Age in Mexico.

    Science.gov (United States)

    Bashash, Morteza; Thomas, Deena; Hu, Howard; Martinez-Mier, E Angeles; Sanchez, Brisa N; Basu, Niladri; Peterson, Karen E; Ettinger, Adrienne S; Wright, Robert; Zhang, Zhenzhen; Liu, Yun; Schnaas, Lourdes; Mercado-García, Adriana; Téllez-Rojo, Martha María; Hernández-Avila, Mauricio

    2017-09-19

    Some evidence suggests that fluoride may be neurotoxic to children. Few of the epidemiologic studies have been longitudinal, had individual measures of fluoride exposure, addressed the impact of prenatal exposures or involved more than 100 participants. Our aim was to estimate the association of prenatal exposure to fluoride with offspring neurocognitive development. We studied participants from the Early Life Exposures in Mexico to Environmental Toxicants (ELEMENT) project. An ion-selective electrode technique was used to measure fluoride in archived urine samples taken from mothers during pregnancy and from their children when 6-12 y old, adjusted for urinary creatinine and specific gravity, respectively. Child intelligence was measured by the General Cognitive Index (GCI) of the McCarthy Scales of Children's Abilities at age 4 and full scale intelligence quotient (IQ) from the Wechsler Abbreviated Scale of Intelligence (WASI) at age 6-12. We had complete data on 299 mother-child pairs, of whom 287 and 211 had data for the GCI and IQ analyses, respectively. Mean (SD) values for urinary fluoride in all of the mothers (n=299) and children with available urine samples (n=211) were 0.90 (0.35) mg/L and 0.82 (0.38) mg/L, respectively. In multivariate models we found that an increase in maternal urine fluoride of 0.5mg/L (approximately the IQR) predicted 3.15 (95% CI: -5.42, -0.87) and 2.50 (95% CI -4.12, -0.59) lower offspring GCI and IQ scores, respectively. In this study, higher prenatal fluoride exposure, in the general range of exposures reported for other general population samples of pregnant women and nonpregnant adults, was associated with lower scores on tests of cognitive function in the offspring at age 4 and 6-12 y. https://doi.org/10.1289/EHP655.

  17. Heart rate variability and the relationship between trauma exposure age, and psychopathology in a post-conflict setting.

    Science.gov (United States)

    Liddell, Belinda J; Kemp, Andrew H; Steel, Zachary; Nickerson, Angela; Bryant, Richard A; Tam, Natalino; Tay, Alvin Kuowei; Silove, Derrick

    2016-05-10

    Cumulative exposure to potentially traumatic events (PTEs) increases risk for mental distress in conflict-affected settings, but the psychophysiological mechanisms that mediate this dose-response relationship are unknown. We investigated diminished heart rate variability (HRV) - an index of vagus nerve function and a robust predictor of emotion regulation capacity - as a vulnerability marker that potentially mediates the association between PTE exposure, age and symptoms of posttraumatic stress disorder (PTSD), psychological distress and aggressive behavior, in a community sample from Timor-Leste - a post-conflict country with a history of mass violence. Resting state heart rate data was recorded from 45 cases of PTSD, depression and intermittent explosive disorder (IED); and 29 non-case controls. Resting HRV was significantly reduced in the combined case group compared with non-cases (p = .021; Cohen's d = 0.5). A significant mediation effect was also observed, whereby a sequence of increased age, reduced HRV and elevated PTSD symptoms mediated the association between PTE exposure and distress (B = .06, SE = .05, 95% CI = [.00-.217]) and aggression (B = .02, SE = .02, 95% CI = [.0003-.069])). The findings demonstrate an association between diminished resting HRV and psychopathology. Moreover, age-related HRV reductions emerged as a potential psychophysiological mechanism that underlies enhanced vulnerability to distress and aggression following cumulative PTE exposure.

  18. The peculiarity of aerobic energy supply of rat tissues of different age upon prolonged ionizing and thermal exposure

    International Nuclear Information System (INIS)

    Tsyhun, G.F.

    1998-01-01

    Energy-producing functions of brain, myocardium, and hepatic mitochondria in mature and immature rats in remote period after prolonged ionizing X-ray at total dose 12,9 m C/kg and thermal exposure (4 hours, 37 degrees centigrade, 25 times) were studied. Dehydrogenase activities (pyruvate-, isocitrate-, 2-oxy glutarate-, succinate- and malate dehydrogenases) were reduced in mitochondria of different tissues of adult rats and it was especially considerable after combined influence. A higher resistance of young rats, as compared to adult ones, to combined radiation-thermal treatments was established

  19. Impact of low dose prenatal ethanol exposure on glucose homeostasis in Sprague-Dawley rats aged up to eight months.

    Directory of Open Access Journals (Sweden)

    Megan E Probyn

    Full Text Available Excessive exposure to alcohol prenatally has a myriad of detrimental effects on the health and well-being of the offspring. It is unknown whether chronic low-moderate exposure of alcohol prenatally has similar and lasting effects on the adult offspring's health. Using our recently developed Sprague-Dawley rat model of 6% chronic prenatal ethanol exposure, this study aimed to determine if this modest level of exposure adversely affects glucose homeostasis in male and female offspring aged up to eight months. Plasma glucose concentrations were measured in late fetal and postnatal life. The pancreas of 30 day old offspring was analysed for β-cell mass. Glucose handling and insulin action was measured at four months using an intraperitoneal glucose tolerance test and insulin challenge, respectively. Body composition and metabolic gene expression were measured at eight months. Despite normoglycaemia in ethanol consuming dams, ethanol-exposed fetuses were hypoglycaemic at embryonic day 20. Ethanol-exposed offspring were normoglycaemic and normoinsulinaemic under basal fasting conditions and had normal pancreatic β-cell mass at postnatal day 30. However, during a glucose tolerance test, male ethanol-exposed offspring were hyperinsulinaemic with increased first phase insulin secretion. Female ethanol-exposed offspring displayed enhanced glucose clearance during an insulin challenge. Body composition and hepatic, muscle and adipose tissue metabolic gene expression levels at eight months were not altered by prenatal ethanol exposure. Low-moderate chronic prenatal ethanol exposure has subtle, sex specific effects on glucose homeostasis in the young adult rat. As aging is associated with glucose dysregulation, further studies will clarify the long lasting effects of prenatal ethanol exposure.

  20. Relationship medical exposure in X-ray diagnosis and loading factor and film/screen system for reduction exposure dose in Aomori. An analysis based on the results of questionnaire

    International Nuclear Information System (INIS)

    Kon, Masanori; Fukushi, Shouji; Oota, Fumio; Kawamura, Kouji; Shinohe, Tetsuo; Suwa, Kouki; Fujii, Kiyosuke; Yamagami, Hirofumi

    2000-01-01

    A fact-finding questionnaire survey on medical exposure in Aomori Prefecture was conducted in September 1998. Of the 23 exposed sites in the body investigated, exposure at 17 sites in adults was investigated in terms of the type of high-voltage generator, imaging conditions (X-ray tube voltage, electric current, exposure time, etc.), photosensitive materials and relative photosensitivity, and entrance surface doses. At 6 of the 17 exposed sites, the relationships between these technical conditions and entrance surface doses were analyzed to consider further reduction of medical exposure. The most frequently used high-voltage generators were inverter generators (about 52%). In many institutions, additional filters were utilized for high-voltage imaging of the chest. Highly sensitive green-emission materials were the most frequently used photosensitive materials (73%). These findings indicate that many institutions are attempting to reduce exposure. Entrance surface doses varied greatly among institutions: and a 100-fold difference was observed in exposure to the chest, Martius, and the pelvis. Further efforts to lower entrance surface doses are therefore necessary to reduce medical exposure. Negative correlations were observed between electric voltage, electric current, and exposure time. Examination of the relationships between entrance surface doses, electric current, and exposure time yielded positive correlations. However, the entrance surface doses may not have been properly calculated in some institutions, and examination of the relationship between the relative sensitivity of the sensitive material and entrance surface doses showed great variability in entrance surface doses between institutions. Based on the above results, it is concluded that further reduction of medical exposure is possible, not only by improving the accuracy of X-ray units/devices, but by choosing a more appropriate of conditions to perform radiography. (K.H.)

  1. Age-dependence of the x-ray-induced deficiency in DNA synthesis in HeLa S3 cells during generation 1

    International Nuclear Information System (INIS)

    Griffiths, T.D.; Tolmach, L.J.

    1975-01-01

    The radiation-induced deficiency in DNA synthesis in Generation 1 was studied as a function of the age of HeLa S3 cells at the time of exposure to 220 kV x rays in the previous generation (Generation 0). The amount of DNA synthesized is dependent on the stage in the generation cycle at which cells are irradiated. The smallest deficiency (20 to 35 percent after a dose of 500 rad) is observed in cells irradiated in early G1 or early G2, while the greatest deficiency (55 to 70 percent after 500 rad) is found in cells irradiated at mitosis or at the G1/S transition. The high sensitivity of cells at G1/S is also manifested by a steeper dose-response curve. Cells irradiated in late G2, past the point where their progression is temporarily blocked by x rays, synthesize a normal amount of DNA in Generation 1, while cells that are held up in the G2 block exhibit deficient synthesis in the next generation. The extent of the deficiency in early G1 cells can be enhanced by treatment with 1 mM hydroxyurea for several hours immediately following irradiation. The possibility that deficient DNA synthesis is related to cell killing, and the relation between the G2 block and deficient synthesis, are discussed

  2. Prenatal methylmercury exposure and language delay at three years of age in the Norwegian Mother and Child Cohort Study.

    Science.gov (United States)

    Vejrup, Kristine; Schjølberg, Synnve; Knutsen, Helle Katrine; Kvalem, Helen Engelstad; Brantsæter, Anne Lise; Meltzer, Helle Margrete; Alexander, Jan; Magnus, Per; Haugen, Margaretha

    2016-01-01

    Prenatal methylmercury (MeHg) exposure and its possible neurodevelopmental effects in susceptible children are of concern. Studies of MeHg exposure and negative health outcomes have shown conflicting results and it has been suggested that co-exposure to other contaminants and/or nutrients in fish may confound the effect of MeHg. Our objective was to examine the association between prenatal exposure to MeHg and language and communication development at three years, adjusting for intake of fish, n-3 long chain polyunsaturated fatty acids (n-3 LCPUFAs) and co-exposure to dioxins and dioxin like polychlorinated biphenyls (dl-PCBs). We used data from the Norwegian Mother and Child Cohort Study (MoBa) collected between 2002 and 2008. The study sample consisted of 46,750 mother-child pairs. MeHg exposure was calculated from reported fish intake during pregnancy by a FFQ in mid-pregnancy. Children's language and communication skills were measured by maternal report on the Dale and Bishop grammar rating and the Ages and Stages communication scale (ASQ). We estimated odds ratios (OR) and 95% confidence intervals (CI) using logistic regressions. Median MeHg exposure was 1.3μg/day, corresponding to 0.14μg/kgbw/week. An exposure level above the 90th percentile (>2.6μg/day, >0.29μg/kgbw/week) was defined as the high MeHg exposure. Results indicated an association between high MeHg exposure and unintelligible speech with an adjusted OR 2.22 (1.31, 3.72). High MeHg exposure was also associated with weaker communication skills adjusted OR 1.33 (1.03, 1.70). Additional adjustment for fish intake strengthened the associations, while adjusting for PCBs and n-3 LCPUFA from diet or from supplements had minor impact. In conclusion, significant associations were found between prenatal MeHg exposure above the 90th percentile and delayed language and communication skills in a generally low exposed population. Copyright © 2016 Elsevier Ltd. All rights reserved.

  3. Prenatal exposure to environmental contaminants and body composition at age 7–9 years

    International Nuclear Information System (INIS)

    Delvaux, Immle; Van Cauwenberghe, Jolijn; Den Hond, Elly; Schoeters, Greet; Govarts, Eva; Nelen, Vera; Baeyens, Willy; Van Larebeke, Nicolas; Sioen, Isabelle

    2014-01-01

    The study aim was to investigate the association between prenatal exposure to endocrine disrupting chemicals (EDCs) and the body composition of 7 to 9 year old Flemish children. The subjects were 114 Flemish children (50% boys) that took part in the first Flemish Environment and Health Study (2002–2006). Cadmium, PCBs, dioxins, p,p′-DDE and HCB were analysed in cord blood/plasma. When the child reached 7–9 years, height, weight, waist circumference and skinfolds were measured. Significant associations between prenatal exposure to EDCs and indicators of body composition were only found in girls. After adjustment for confounders and covariates, a significant negative association was found in girls between prenatal cadmium exposure and weight, BMI and waist circumference (indicator of abdominal fat) and the sum of four skinfolds (indicator of subcutaneous fat). In contrast, a significant positive association (after adjustment for confounders/covariates) was found between prenatal p,p′-DDE exposure and waist circumference as well as waist/height ratio in girls (indicators of abdominal fat). No significant associations were found for prenatal PCBs, dioxins and HCB exposure after adjustment for confounders/covariates. This study suggests a positive association between prenatal p,p′-DDE exposure and indicators of abdominal fat and a negative association between prenatal cadmium exposure and indicators of both abdominal as well as subcutaneous fat in girls between 7 and 9 years old. - Highlights: • Associations between prenatal contaminant exposure and anthropometrics in children. • Significant association only found in girls. • No significant associations found for prenatal PCBs, dioxins and HCB exposure. • Girls: negative association between cadmium and abdominal and subcutaneous fat. • Girls: positive association between p,p′-DDE and indicators of abdominal fat

  4. Prenatal exposure to environmental contaminants and body composition at age 7–9 years

    Energy Technology Data Exchange (ETDEWEB)

    Delvaux, Immle; Van Cauwenberghe, Jolijn [Department of Public Health, Ghent University, UZ 2 Blok A, De Pintelaan 185, 9000 Ghent (Belgium); Den Hond, Elly; Schoeters, Greet; Govarts, Eva [Flemish Institute for Technological Research (VITO), Environmental Risk and Health, Boeretang 200, 2400 Mol (Belgium); Nelen, Vera [Department of Health, Provincial Institute for Hygiene, Kronenburgstraat 45, 2000 Antwerp (Belgium); Baeyens, Willy [Department of Analytical and Environmental Chemistry, Free University of Brussels, Pleinlaan 2, 1050 Elsene (Belgium); Van Larebeke, Nicolas [Department of Radiotherapy and Nuclear Medicine, Ghent University, De Pintelaan 185, 9000 Ghent (Belgium); Sioen, Isabelle, E-mail: isabelle.sioen@ugent.be [Department of Public Health, Ghent University, UZ 2 Blok A, De Pintelaan 185, 9000 Ghent (Belgium); FWO Research Foundation, Egmontstraat 5, 1000 Brussels (Belgium)

    2014-07-15

    The study aim was to investigate the association between prenatal exposure to endocrine disrupting chemicals (EDCs) and the body composition of 7 to 9 year old Flemish children. The subjects were 114 Flemish children (50% boys) that took part in the first Flemish Environment and Health Study (2002–2006). Cadmium, PCBs, dioxins, p,p′-DDE and HCB were analysed in cord blood/plasma. When the child reached 7–9 years, height, weight, waist circumference and skinfolds were measured. Significant associations between prenatal exposure to EDCs and indicators of body composition were only found in girls. After adjustment for confounders and covariates, a significant negative association was found in girls between prenatal cadmium exposure and weight, BMI and waist circumference (indicator of abdominal fat) and the sum of four skinfolds (indicator of subcutaneous fat). In contrast, a significant positive association (after adjustment for confounders/covariates) was found between prenatal p,p′-DDE exposure and waist circumference as well as waist/height ratio in girls (indicators of abdominal fat). No significant associations were found for prenatal PCBs, dioxins and HCB exposure after adjustment for confounders/covariates. This study suggests a positive association between prenatal p,p′-DDE exposure and indicators of abdominal fat and a negative association between prenatal cadmium exposure and indicators of both abdominal as well as subcutaneous fat in girls between 7 and 9 years old. - Highlights: • Associations between prenatal contaminant exposure and anthropometrics in children. • Significant association only found in girls. • No significant associations found for prenatal PCBs, dioxins and HCB exposure. • Girls: negative association between cadmium and abdominal and subcutaneous fat. • Girls: positive association between p,p′-DDE and indicators of abdominal fat.

  5. [Induction of micronuclei in peripheral blood and bone marrow reticulocytes of male mice after subchronic exposure to x-rays and bisphenol A].

    Science.gov (United States)

    Radzikowska, Joanna; Gajowik, Aneta; Dobrzyńska, Małgorzata

    2012-01-01

    Ionizing radiation and xenoestrogens are widely present in the human environment. Bisphenol A (BPA) is used to manufacture polycarbonate plastics, epoxy and polyester resins. BPA is present in a great variety of products including: baby bottles, compact disks, thermal paper, safety helmets, bullet resistant laminate, plastic windows, car parts, adhesives, protective coatings, powder paints, polycarbonate bottles and containers, the sheathing of electrical and electronic parts, dental fillings. Food and beverage cans are protected from rusting and corrosion by the application of epoxy resins as inner coatings. Human activities involving the use of radiation and radioactive materials in industry, agriculture and research cause radiation exposure in addition to natural exposure coming from cosmic rays and naturally occurring radioactive substances. The aim of the study was to estimate the effects of bisphenol A, X-rays and combined exposure to X-rays and bisphenol A on the induction of micronuclei in the peripheral blood and in bone marrow reticulocytes of laboratory mice. Pzh-Sfis male mice were exposed for 8 weeks. Animals were treated with bisphenol A diluted in drinking water (5 mg/kg bw, 10 mg/kg bw, 20 mg/kg bw), irradiated 0.05 Gy of X-rays or exposed to a combination of both (0.05 Gy + 5 mg/kg bw BPA). The samples of peripheral blood were taken at 1, 4 and 8 week following the start of exposure, whereas the bone marrow after the end of experiment, only. The induction of micronuclei in reticulocytes were evaluated by using fluorescence microscope. Bisphenol A as well as ionizing radiation stimulated induction of micronuclei in peripheral blood and bone marrow reticulocytes. After the irradiation the level of micronuclei increased, whereas after exposure to BPA decreased related to time expired from beginning of experiment. Combined exposure of ionizing radiation and bisphenol A induced significantly higher frequency of micronuclei compared to the effect

  6. The Restless Universe - Understanding X-Ray Astronomy in the Age of Chandra and Newton

    Science.gov (United States)

    Schlegel, Eric M.

    2002-10-01

    Carl Sagan once noted that there is only one generation that gets to see things for the first time. We are in the midst of such a time right now, standing on the threshold of discovery in the young and remarkable field of X-ray astronomy. In The Restless Universe , astronomer Eric Schlegel offers readers an informative survey of this cutting-edge science. Two major space observatories launched in the last few years--NASA's Chandra and the European Newton --are now orbiting the Earth, sending back a gold mine of data on the X-ray universe. Schlegel, who has worked on the Chandra project for seven years, describes the building and launching of this space-based X-ray observatory. But the book goes far beyond the story of Chandra . What Schlegel provides here is the background a nonscientist would need to grasp the present and follow the future of X-ray astronomy. He looks at the relatively brief history of the field, the hardware used to detect X-rays, the satellites--past, present, and future--that have been or will be flown to collect the data, the way astronomers interpret this data, and, perhaps most important, the insights we have already learned as well as speculations about what we may soon discover. And throughout the book, Schlegel conveys the excitement of looking at the universe from the perspective brought by these new observatories and the sharper view they deliver. Drawing on observations obtained from Chandra, Newton , and previous X-ray observatories, The Restless Universe gives a first look at an exciting field which significantly enriches our understanding of the universe.

  7. Hepatic changes caused by exposure to telecobalt rays as detected by scintigraphy and computed tomography

    International Nuclear Information System (INIS)

    Lueth, I.

    1987-01-01

    Hepatic scintiscans obtained in a cohort of 111 patients subjected to partial irradiation of the liver using telecobalt showed low density spots for 53 of those individuals. Comparative assessments in a control group proved the liver's accumulation behaviour to be totally unrelated to factors like age, sex and dose administered. The liver is only to a very limited extent capable of recovering from radiation damage that is severe enough to be detected by scintigraphy or computed tomography. In the group examined here, spontaneous recovery was seen in no more than 7.5% of cases. Long-term plotting of the hepatic radioactivity levels seen in scintigrammes showed these to be reduced for periods of up to nine years. Such pathological changes were already observed at radiation levels as low as 12 Gy, even though a definite dose-dependency of defective accumulation, as shown by scintigraphy or computed tomography, could not be established. Particular mention should here be made of the fact that the losses of activity seen in hepatic scintiscans were not necessarily confirmed by pathological findings revealed at the same time on the basis of computed tomography. Liver function tests in the serum permitted no links to be established between the occurrence of low density spots in the scintiscans or tomograms and typical enzyme patterns that may be interpreted as being suggestive of radiation injury. (orig.) [de

  8. Analysis of radiological examination request forms in conjunction with justification of X-ray exposures

    International Nuclear Information System (INIS)

    Triantopoulou, Ch.; Tsalafoutas, I.; Maniatis, P.; Papavdis, D.; Raios, G.; Siafas, I.; Velonakis, S.; Koulentianos, E.

    2005-01-01

    Objectives: To evaluate the adequacy of patient data and clinical information transmitted to the radiological departments by the referring clinicians in view of the justification demands concerning the radiological examinations, as those are described in the Radiation Protection Regulations of the European Union Nations. Materials and methods: Request forms for 1708 patients referred to radiology department and 410 referred to the CT department were evaluated concerning the proper completion of the form fields. Furthermore, for CT examinations a more detailed evaluation was carried out, to assess the rationalistic use of CT within the diagnostic algorithm. Results: Not properly completed request forms to both departments were observed, however, the omissions were more prominent for the referrals to the radiology department, where the age and the probable clinical diagnosis was not given in 81.5 and 46% of the forms, respectively. Furthermore, the emergency indication was less cautiously used compared to the CT requests. For the CT department 33.3% of requests were justified and the final diagnosis was included in the referring doctor's probable clinical diagnosis. U/S was the examination of choice in 51% of the cases where an examination should have been performed before CT and in 70.6% of the cases where an alternative examination was proposed. Conclusions: The inadequate transmission of clinical information and the large number of not fully justified CT requests observed in this study are typical examples of the various problems that radiologists have to face in order to apply the justification directives

  9. Dose-response relationship of γ-H2AX foci induction in human lymphocytes after X-rays exposure

    International Nuclear Information System (INIS)

    Mandina, Tania; Roch-Lefevre, Sandrine H.; Voisin, Pascale; Gonzalez, Jorge E.; Lamadrid, Ana I.; Romero, Ivonne; Garcia, Omar; Voisin, Philippe; Roy, Laurence

    2011-01-01

    Biological dosimeters are recommended for dose estimation in case of human overexposure to ionising radiation. Rapid measurement of γ-H2AX foci as a marker of DNA double-strand breaks (DSB) induction has been recently tested with this purpose. Here we reported a dose-response relationship after X-ray irradiation at different times post-exposure. Blood samples were obtained from several healthy donors and exposed to doses between 0 and 2 Gy. After irradiation, blood samples were incubated at 37 deg. C during 0.5 h, 5 h, and 8 h. Scoring of cells and γ-H2AX foci was performed by software. The dose-response curves for different incubation times were as follows: Y (0.5h) = 11.66D + 0.15 (R 2 = 0.99), Y (5h) = 2.44D + 0.15 (R 2 = 0.99), Y (8h) = 1.57D + 0.22 (R 2 = 0.99). At 0.5 h post-exposure, the dose-response relationship for X-irradiated lymphocytes was similar to the one obtained after gamma-irradiation using the same protocol. On the other hand, the results were not similar after 8 h due to different kinetics after gamma- and X-irradiation. Our results confirm the possibilities of using γ-H2AX foci method for dose estimation in a period from 0.5 h up to 8 h post X-irradiation and support the hypothesis of differences in γ-H2AX foci kinetics after gamma- and X-irradiation in vitro.

  10. Dose-response relationship of {gamma}-H2AX foci induction in human lymphocytes after X-rays exposure