WorldWideScience

Sample records for acute x-ray exposure

  1. Low exposure x-ray transmission measurements for contrast media detection with filtered x-rays

    International Nuclear Information System (INIS)

    A feasibility study of X-ray transmission measurements for contrast media with less exposure using filtered X-rays and their energy information is described. Based on measurements of the energy spectra of La-filtered X-rays, sensitivity to the contrast media and the relative quantity of dose exposure of filtered X-rays as the ratio to white X-rays are shown. The dose exposure for the measurement of iodine contrast media is reduced by more than 50% with a 400 μm thick La filter. By using a filter with atomic number close to that of iodine such as Cs and Ba, a greater reduction in dose exposure with a smaller increase in the current of the X-ray tube is expected. (author)

  2. A paediatric X-ray exposure chart

    International Nuclear Information System (INIS)

    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

  3. Reduction of Unwarranted Patient Exposure in X-ray examinations

    OpenAIRE

    F. Bouzarjomehri

    2003-01-01

    Background/Objective: Protecting patients from unwarranted radiation is a great safety concern to radiology practitioners, as medical X-rays are the largest source of public exposure to ionizing radiation. Materials and Methods: The entrance skin exposure (ESE) was measured by solid state dosimeter for five common types of radiography. Dosimetery for a human of average size was performed in the radiology centers. The results of first ESE measurements together with recommendations according to...

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

    International Nuclear Information System (INIS)

    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. (U.K.)

  5. Retrospective epidemiological study of the X-Ray exposure

    International Nuclear Information System (INIS)

    There are a large amount of epidemiological studies nowadays in the world which are devoted to the analysis of the medical effects and the radiation risk. But a few of them deal with the analysis of the medical diagnostic radiation influence on health. It is appropriate, for the large compared contingent of the patients and the possibility of comparing them in several decades after the exposure are necessary for the evaluation of the influence of small doses on health. Meanwhile the X-ray exposure of the population is one of the most important types of radiation influence among all the kinds and sources of radiation. It is characterized by high dose rate and the possibility of multiple influence on a weakened and diseased organism. In connection with that, the eleven of the indices of population health was analyzed for the first time in Russia. The population was influenced by different levels of X-ray exposure 10-50 years ago. The research was carried out in the two groups of the Tumen (Siberia) regions. These regions are more or less equal in the climatic; ecologic, social-economic and demographic conditions. Nevertheless, they are different even only in the value of accumulated doses of X-ray exposure of the population (mostly in 50-70s) more than three times. Disease and mortality cancer of population of the last ten years in the regions were analyzed. The regions were selected taking into account the absence of the influence of other possible negative environmental factors. The data are found as the result of the dosimetric and epidemiological studies, and the processing of the archive statistic information. These researches demonstrated that on the whole there is the considerable statistically proved rise of disease cancer in the regions with high level of long term accumulated doses of X-ray exposure of population. Inter-district differences in disease and mortality cancer run up to three times among people aged 60 and older. There are no statistically

  6. Retrospective epidemiological study of the X-Ray exposure

    Energy Technology Data Exchange (ETDEWEB)

    Ivanov, E. V.; Kalnitsky, S. A.; Shubic, V. M.

    2004-07-01

    There are a large amount of epidemiological studies nowadays in the world which are devoted to the analysis of the medical effects and the radiation risk. But a few of them deal with the analysis of the medical diagnostic radiation influence on health. It is appropriate, for the large compared contingent of the patients and the possibility of comparing them in several decades after the exposure are necessary for the evaluation of the influence of small doses on health. Meanwhile the X-ray exposure of the population is one of the most important types of radiation influence among all the kinds and sources of radiation. It is characterized by high dose rate and the possibility of multiple influence on a weakened and diseased organism. In connection with that, the eleven of the indices of population health was analyzed for the first time in Russia. The population was influenced by different levels of X-ray exposure 10-50 years ago. The research was carried out in the two groups of the Tumen (Siberia) regions. These regions are more or less equal in the climatic; ecologic, social-economic and demographic conditions. Nevertheless, they are different even only in the value of accumulated doses of X-ray exposure of the population (mostly in 50-70s) more than three times. Disease and mortality cancer of population of the last ten years in the regions were analyzed. The regions were selected taking into account the absence of the influence of other possible negative environmental factors. The data are found as the result of the dosimetric and epidemiological studies, and the processing of the archive statistic information. These researches demonstrated that on the whole there is the considerable statistically proved rise of disease cancer in the regions with high level of long term accumulated doses of X-ray exposure of population. Inter-district differences in disease and mortality cancer run up to three times among people aged 60 and older. There are no statistically

  7. 21 CFR 872.1820 - Dental x-ray exposure alignment device.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Dental x-ray exposure alignment device. 872.1820... (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Diagnostic Devices § 872.1820 Dental x-ray exposure alignment device. (a) Identification. A dental x-ray exposure alignment device is a device intended to position...

  8. Reduction of Unwarranted Patient Exposure in X-ray examinations

    Directory of Open Access Journals (Sweden)

    "F. Bouzarjomehri "

    2003-06-01

    Full Text Available Background/Objective: Protecting patients from unwarranted radiation is a great safety concern to radiology practitioners, as medical X-rays are the largest source of public exposure to ionizing radiation. Materials and Methods: The entrance skin exposure (ESE was measured by solid state dosimeter for five common types of radiography. Dosimetery for a human of average size was performed in the radiology centers. The results of first ESE measurements together with recommendations according to CRCPD and NRPB were returned to the radiology centers. Two months later, all ESE measurements were repeated. Results: The mean, maximum and 3rd quartile ESEs were significantly decreased compared with the first measurements. This quality control program managed to decrease the patient doses (ESEs of AP and lateral lumbar spine, AP cervical and lateral skull radiographs by about %10, 25%, 30% and 25% respectively. Conclusion: This survey indicates that in X-ray examinations of the lumbar, thoracic and cervical spine, skull and chest the patient dose can be significantly reduced without ruining the imaging quality.

  9. Radiation Exposure in X-Ray and CT Examinations

    Science.gov (United States)

    ... A-Z Radiation Dose in X-Ray and CT Exams What are x-rays and what do ... natural background radiation for: ABDOMINAL REGION: Computed Tomography (CT)-Abdomen and Pelvis 10 mSv 3 years Computed ...

  10. Imaging local electric fields produced upon synchrotron X-ray exposure.

    Science.gov (United States)

    Dettmar, Christopher M; Newman, Justin A; Toth, Scott J; Becker, Michael; Fischetti, Robert F; Simpson, Garth J

    2015-01-20

    Electron-hole separation following hard X-ray absorption during diffraction analysis of soft materials under cryogenic conditions produces substantial local electric fields visualizable by second harmonic generation (SHG) microscopy. Monte Carlo simulations of X-ray photoelectron trajectories suggest the formation of substantial local electric fields in the regions adjacent to those exposed to X-rays, indicating a possible electric-field-induced SHG (EFISH) mechanism for generating the observed signal. In studies of amorphous vitreous solvents, analysis of the SHG spatial profiles following X-ray microbeam exposure was consistent with an EFISH mechanism. Within protein crystals, exposure to 12-keV (1.033-Å) X-rays resulted in increased SHG in the region extending ∼ 3 μm beyond the borders of the X-ray beam. Moderate X-ray exposures typical of those used for crystal centering by raster scanning through an X-ray beam were sufficient to produce static electric fields easily detectable by SHG. The X-ray-induced SHG activity was observed with no measurable loss for longer than 2 wk while maintained under cryogenic conditions, but disappeared if annealed to room temperature for a few seconds. These results provide direct experimental observables capable of validating simulations of X-ray-induced damage within soft materials. In addition, X-ray-induced local fields may potentially impact diffraction resolution through localized piezoelectric distortions of the lattice.

  11. X-ray diagnosis in acute and chronic sport injuries

    International Nuclear Information System (INIS)

    Stress X-ray and arthrography are of importance in the diagnosis of joint injuries. Stress X-rays are of great value to testify instability of acromioclavicular joint, metacarpophalangeal joint of the thumb, but also the knee and the ankle joint. With arthrography it is possible to show up a rupture of the rotator cuff of the shoulder and also a lesion of the triangular disc of the wrist. Indication, technique and the interpretation of the stress X-rays and the arthrogramms are discussed. (orig.)

  12. X-ray diagnosis in acute and chronic sport injuries

    Energy Technology Data Exchange (ETDEWEB)

    Martinek, H.; Egkher, E.; Schratter, H.

    1982-09-01

    Stress X-ray and arthrography are of importance in the diagnosis of joint injuries. Stress X-rays are of great value to testify instability of acromioclavicular joint, metacarpophalangeal joint of the thumb, but also the knee and the ankle joint. With arthrography it is possible to show up a rupture of the rotator cuff of the shoulder and also a lesion of the triangular disc of the wrist. Indication, technique and the interpretation of the stress X-rays and the arthrogramms are discussed.

  13. Results of the control of the exposure times of dental X-ray

    International Nuclear Information System (INIS)

    The X-ray gyroscope presented enables the dental radiological personnel to check simply the exposure time of the X-ray unit as to its accuracy. Any load half-wave interval is displayed by a density point on an ORWO XR 5 3/4 x 7 1/2 radiographic film by utilizing the regularity of the emission ratio of one-pulse X-ray generators. A density point corresponds to 0.02 seconds. This method has been used to check and evaluate timers of 10 different X-ray units. The 'Stomax 100' timers showed the least deviations to the exposure time required. (author)

  14. 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)

    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)

  15. 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)

  16. Breast neoplasms in women treated with x-rays for acute postpartum mastitis

    International Nuclear Information System (INIS)

    Breast cancer has been studied by mail survey up to 34 years in 571 of 606 women treated with x-rays for acute postpartum mastitis. The incidence of neoplasms was compared with that of three nonirradiated control groups--nonirradiated sisters of the treated women, women with acute postpartum mastitis not treated with X-rays, and their nonirradiated sisters. For the irradiated group, with a mean dose of 247 rads to both breasts, the overall relative risk of breast cancer was 2.2 for years 10 to 34 post irradiation and 3.6 for 20 to 34. The dose response for malignant and benign breast neoplasms was compatible with a linear fit. For comparable total doses, fractionation of exposure did not reduce carcinogenic action. Women over age 30 years at radiation treatment had as great an excess risk of breast cancer as did younger women. The overall excess risk of developing breast cancer was about 8 to 10 cases per million women per rad per year, an increase of about 0.5% per rad

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

    International Nuclear Information System (INIS)

    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

  18. X-ray characteristics of heart failure in patients with acute myocardial infarction

    International Nuclear Information System (INIS)

    Results of chest biomedical radiography in 250 men aged 22-69 years who had acute myocardial infarction were evaluated. Data were compared with the results of ECG, echocardiography, Judkins coronarography, and left ventriculography. X-ray signs of pulmonary venous hypertension in acute myocardial infarction, even not followed by cardiomegalia suggest lower left ventricular myocardial contractility. In this connection, the significance of follow-up X-ray monitoring becomes higher. In 25% of the young patients (aged 22-40 years) with prior acute myocardial infarction, the dimensions of the heart may be in the normal ranges even in the presence of X-ray signs of venous congestion. If there are no signs of mitral regurgitation in patients with ischremic heart disease, the enlarged left atrium may be regarded as an indirect X-ray sign of reduced left ventricular contractility. Extent of necrosis in patients with myocardial infarction effects hemodynamic changes in lungs

  19. Effect of Multi-Shot X-Ray Exposures in IFE Armor Materials

    Energy Technology Data Exchange (ETDEWEB)

    Latkowski, J F; Abbott, R P; Schmitt, R C; Bell, B K

    2004-12-10

    As part of the High Average Power Laser (HAPL) program the performance of tungsten as an armor material is being studied. While the armor would be exposed to neutrons, x-rays and ions within an inertial fusion energy (IFE) power plant, the thermomechanical effects are believed to dominate. Using a pulsed x-ray source, long-term exposures of tungsten have been completed at fluences that are of interest for the IFE application. Modeling is used in conjunction with experiments on the XAPPER x-ray damage facility in an effort to recreate the effects that would be expected in an operating IFE power plant. X-ray exposures have been completed for a variety of x-ray fluences and number of shots. Analysis of the samples suggests that surface roughening has a threshold that is very close to the fluences that reproduce the peak temperatures expected in an IFE armor material.

  20. X-ray characteristics of acute pneumonia and its outcomes in infants

    International Nuclear Information System (INIS)

    The results of an X-ray stUdy of 921 infants of the first 3 years of life with acute pneumonia (focal-669, focal-conflUent-197, destrUctive-55) were analyzed. In 188 patients with the lethal oUtcome the X-ray and pathomorphological data were compared. Repeated examination of 336 children was done 1-2 yrs. later. The specificities of an X-ray and morphological picture of focal, focal-confluent and destructive pnevmonia and outcomes in infants are presented

  1. Radiation exposure during chest X-ray examinations in a premature intensive care unit: phantom studies

    International Nuclear Information System (INIS)

    Background. There are few reports on the radiation dose received by infants, their family and radiographers exposed to scatter radiation in a premature baby intensive care unit. Objective. To evaluate the degree of radiation exposure from diagnostic X-ray examinations with mobile X-ray machines in a premature intensive care unit. Materials and methods. The radiation exposure of an adjacent newborn, the radiographer and other persons in the room was simulated using phantoms during X-ray examination of the chest using vertical and horizontal beams. Results. Most of the measured doses were below the registration limit of the measuring apparatus and had to be extrapolated by multiple exposures. Without exception, the maximal doses were significantly lower than the permitted limit for persons not professionally exposed to X-rays. Conclusions. Recommendations to avoid unnecessary radiation exposure are given. (orig.)

  2. 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.

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

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Danubia B.; Santos, Marcus A.P.; Barros, Fabio R.; Santos, Luiz A.P., E-mail: danubia@hotmail.com, E-mail: lasantos@cnen.gov.br [Centro Regional de Ciencias Nucleares do Nordeste (CRCN-NE/CNEN-PE), Recife, PE (Brazil)

    2013-07-01

    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{sub rx}, the true X-ray exposure time; 2) T{sub 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)

  4. Medical x-ray exposure doses as contaminants of atomic bomb doses.

    Science.gov (United States)

    Yamamoto, O; Antoku, S; Russell, W J; Fujita, S; Sawada, S

    1988-03-01

    Since 1967 at the times of their biennial ABCC/RERF radiological examinations, all Adult Health Study (AHS) subjects have been interviewed to determine the exposures to medical x-rays they experienced in institutions other than RERF in order to estimate the numbers of examinations and corresponding doses which they received. These data have been stored on computer tapes together with the doses these subjects received during their radiological examinations in the ABCC/RERF Department of Radiology. Thus, their medical x-ray doses are available along with their atomic bomb doses (tentative 1965 doses revised, T65DR) for assessment of the role of ionizing radiation in the development of diseases. The medical x-ray doses incurred at RERF were assessed by means of phantom dosimetry. Those at other institutions were determined using phantom dosimetry data and results of surveys for trends in radiological examinations in Hiroshima and Nagasaki. By the end of 1982, the average medical x-ray doses to the active bone marrow were 12.04 mGy for A-bomb exposed groups and 8.92 mGy for control groups (not-in-cities); to the male gonads, 2.26 mGy and 1.89 mGy, respectively; and to the female gonads, 17.45 mGy and 12.58 mGy, respectively. Results for Hiroshima and Nagasaki were similar. The main impact of medical x-ray doses was in the lowest T65DR group. Medical x-ray active bone marrow doses ranged from 0.05-500% (mean, 35%) of A-bomb doses in the 10-99 mGy T65DR group. In the 100-999 mGy T65DR group, medical x-ray active bone marrow doses ranged from 0.005-50% (mean, 5%) of their T65DR. In the greater than 1,000-mGy T65DR group, medical x-ray exposures were proportionally less. Female active bone marrow and gonad doses were similar in magnitude to the male active bone marrow doses. Medical x-ray exposures produced smaller doses to the gonads of males than to those of the females. The use of medical x-rays is steadily increasing. Careful consideration of doses from medical sources

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

    International Nuclear Information System (INIS)

    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

  6. Handheld X-ray Fluorescence Spectrometers: Radiation Exposure Risks of Matrix-Specific Measurement Scenarios.

    Science.gov (United States)

    Rouillon, Marek; Kristensen, Louise J; Gore, Damian B

    2015-07-01

    This study investigates X-ray intensity and dispersion around handheld X-ray fluorescence (XRF) instruments during the measurement of a range of sample matrices to establish radiation exposure risk during operation. Four handheld XRF instruments representing three manufacturers were used on four smooth, flat-lying materials of contrasting matrix composition. Dose rates were measured at 10, 20, 30, and 40 cm intervals every 30° around the instrument at 0 and 45° from the horizontal, as well as vertically from the instrument screen. The analysis of polyethylene recorded dose rates 156 times higher (on average) than steel measurements and 34 times higher than both quartz sand and quartz sandstone. A worst-case exposure scenario was assumed where a user analyses a polyethylene material at arms reach for 1 h each working day for one year. This scenario resulted in an effective body dose of 73.5 μSv, equivalent to three to four chest X-rays (20 μSv) a year, 20 times lower than the average annual background radiation exposure in Australia and well below the annual exposure limit of 1 mSv for non-radiation workers. This study finds the advantages of using handheld XRF spectrometers far outweighs the risk of low radiation exposure linked to X-ray scattering from samples. PMID:26037330

  7. Radiation exposure of children and young adults during X-ray investigations - experience and conclusions

    International Nuclear Information System (INIS)

    After discussing the existing regulations for radiation protection of patients in the field of pediatric X-ray diagnostics in the GDR the use of the effective dose equivalent HE and the medium dose equivalent HM for the determination of radiation exposure to children is shortly discussed. Using computer tomography images to determine the position and size of organs of children, and the data from measured depth dose distributions, the exposure related to the entrance dose caused by frequent X-ray examinations was calculated. Measurements of entrance doses at 3 pediatric hospitals for all examination types and the determination of the frequency of X-ray radiographies at 10 hospitals and 10 smaller diagnostic departments were used to calculate the per caput and the collective dose equivalents in the different age groups. Altogether the per caput dose equivalent of the children amounts to approximately 30% of the corresponding value for adults. As a conclusion, the following measures for the further reduction of radiation exposure are proposed: (1) technical measures like fixation of patients, shielding of organs, quality assurance, (2) elaboration of legal regulations, e.g. of a decree on the performance of pediatric X-ray examinations, and (3) training and continued education. Only by these means an appropriate indication (justification) and an efficient reduction of radiation exposure (optimization) can be achieved. (author)

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

    International Nuclear Information System (INIS)

    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

  9. Chest X ray changes in severe acute respiratory syndrome cases after discontinuation of glucocorticosteroids treatment

    Institute of Scientific and Technical Information of China (English)

    姚婉贞; 陈亚红; 张立强; 王筱宏; 孙永昌; 孙威; 韩江莉; 张福春; 郑亚安; 孙伯章; 贺蓓; 赵鸣武

    2004-01-01

    @@ Severe acute respiratory syndrome (SARS) is a disease identified in Asia, North America and Europe. The drugs for treatment and prevention of and vaccine for the disease are in research.1,2 There is still no agreement on glucocorticosteroid treatment of SARS. In treatment of SARS patients with glucocorticosteroids, we found 5 cases whose chest X ray changes were different from what the literature reported.

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

    International Nuclear Information System (INIS)

    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.

  11. 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.

  12. Medical radiation exposures from diagnostic x-ray procedures in India

    International Nuclear Information System (INIS)

    Medical exposures primarily refer to exposures to individuals as part of their own diagnosis or treatment. Diagnostic radiology continues to be the largest contributor to the effective dose to the population from all man-made sources of radiation. It is estimated that in India there are, on an average 105 x-ray examinations per 1000 persons per year, and that the annual per caput effective dose from medical exposures is 0.02 mSv. On the basis of consideration of benefit versus risk, the International Commission on Radiological Protection (ICRP) does not specify dose limits for medical exposure. The International Atomic Energy Agency stipulates that guidance levels for doses for each radiological procedure must be established. From a review of the doses to patients in diagnostic radiology reported by the United Nations Scientific Committee on the Effects of Atomic Radiation, it is observed that medical x-ray exposure is quite low in India. This could be attributed to the low frequency of x-ray examinations in the country and partly to good quality equipment, safe work practices and the type and frequency of a particular type of examination. (author). 10 refs., 2 figs., 4 tabs

  13. The X-ray analysis of pulmonary manifestations in acute aspiration of trichlorethane

    International Nuclear Information System (INIS)

    Objective: To discuss the X-ray pulmonary changes in patients with acute aspiration of trichlorethane. Methods: Among 48 cases with acute aspiration of trichlorethane, 7 were male and 41 female, with ages ranged from 5.5 to 50 years old, mean age was 13.5 years old. 4 patients were diagnosed as mild acute intoxication, 22 as aspirating reaction, and 22 as uncomfortable reaction. And chest radiography was performed in all the cases. Results Pneumonia and bronchopneumonia was found in 4 cases with acute intoxication, inflammation around bronchial branches in 22 cases with aspirating reaction. The other cases were negative findings. Conclusions: Acute aspiration of trichlorethane may cause pneumonia, bronchopneumonia and inflammation around bronchial branches, which can be detected by chest radiography. (authors)

  14. Mutation induction in human cells after low dose X ray exposure

    International Nuclear Information System (INIS)

    Mutations induced after low dose ionising radiation exposure have been intensively analysed not only for radiation risk estimation but also for basic understanding of cellular responses. Human lymphoblastoid TK6-20C cells were irradiated with 100 mGy of X rays and mutation at the heterozygous thymidine kinase (TK) locus was selected by trifluorothymidine resistance. Although the mutation frequency at the TK locus increased from 5.6x10-6 to 7.4x10-6, this increase was not statistically significant. However, molecular analysis of TK mutants exhibiting loss of heterozygocity (LOH) demonstrated a clear effect of such low dose IR exposure. Exposure to 100 mGy X ray increased the fraction of hemizygous-LOH from 10% to 42%. In previous experiments, a similar tendency in the increase of hemizygous-LOH was also observed in TK6 cells after exposure to a 2 Gy dose of X rays. This type of LOH can be considered as a result of end-joining repair of DNA double strand breaks. (author)

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

    International Nuclear Information System (INIS)

    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

  16. Beamline and exposure station for deep x-ray lithography at the Advanced Photon Source

    Energy Technology Data Exchange (ETDEWEB)

    Lai, B.; Mancini, D.C.; Yun, W.; Gluskin, E.

    1996-12-31

    APS is a third-generation synchrotron radiation source. With an x-ray energy of 19.5 keV and highly collimated beam (<0.1 mrad), APS is well suited for producing high-aspect-ratio microstructures in thick resist films (> 1 mm) using deep x-ray lithography (DXRL). The 2-BM beamline was constructed and will be used for DXRL at APS. Selection of appropriate x-ray energy range is done through a variable-angle mirror and various filters in the beamline. At the exposure station, the beam size will be 100(H) x 5(V) mm{sup 2}. Uniform exposure will be achieved by a high-speed (100 mm/sec) vertical scanner, which allows precise angular ({approximately}0.1 mrad) and positional (< 1 {mu}m) control of the sample, allowing full use of the highly collimated beam for lateral accuracy and control of sidewall slopes during exposure of thick resists, as well as generation of conicals and other profiles. For 1-mm-thick PMMA, a 100 x 25 mm{sup 2} area can be fully exposed in about 1/2 hr, while even 10-mm-thick PMMA will require only 2-3 hours.

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

    International Nuclear Information System (INIS)

    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)

  18. Determinants of exposure to chemical pollutants in wet X-ray film processing in Iran.

    Science.gov (United States)

    Kakooei, Hossein; Ardakani, Mehdi B; Sadighi, Alireza

    2007-07-15

    The aim of the current study was to measure glutaraldehyde, acetic acid and sulfur dioxide and levels inside wet x-ray processing areas in a developing country and comparing data with those in developed countries. Forty-five radiographers from 10 educational hospitals affiliated to the Tehran University of Medical Sciences (TUMS) in Tehran, Iran participated in this descriptive-analytical study. Exposure to glutaraldehyde (a constituent of developer chemistry), acetic acid (a constituent of fixer chemistry) and sulfur dioxide (a byproduct of sulfites present in both developer and fixer solutions) was measured in all participants as well as area exposure. Average full-shift exposure to glutaraldehyde, acetic acid and sulfur dioxide were 0.0018, 2.65 and 1.64 mg m(-1), respectively. The results showed that the TUMS radiographers full-shift exposures are generally lower than the American Conference of Governmental Industrial Hygienists (ACGIH) recommended levels. The concentration of glutaraldehyde collected by area sampling (darkroom) was almost five times (0.0104 mg m(-3)) greater than taken by personal sampling. Exposure to the chemical pollutants in the currents study were generally higher than in developed countries. Identification of these key exposure determinants is useful in targeting exposure evaluation and controls to reduce developer and fixer chemicals exposures in the radiology departments. Employing of a digital imaging system that do not involve wet x-ray processing of photographic film would be a useful device for radiographers protection. PMID:19070154

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

    Energy Technology Data Exchange (ETDEWEB)

    Menezes, Claudio J.M.; Santos, Luiz A.P. dos, E-mail: cjmm@cnen.gov.b [Centro Regional de Ciencias Nucleares (CRCN-NE/CNEN-PE), Recife, PE (Brazil)

    2009-07-01

    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)

  20. Efficient E-Beam Lithography Exposure Strategies for Diffractive X-ray Optics

    Science.gov (United States)

    Guzenko, V. A.; Romijn, J.; Vila-Comamala, J.; Gorelick, S.; David, C.

    2011-09-01

    Exposure of structures with rotational symmetry by means of electron beam lithography is not trivial, because the e-beam writers are usually designed to deal with the data defined in Cartesian coordinates. Fabrication of circular nanostructures like Fresnel zone plates (FZPs) for x-ray microscopy applications requires exposures with resolution well below 1 nm. Therefore, special attention has to be paid to the efficient exposure data preparation, which will guarantee required precision and allow keeping the exposure time low. In this article, we describe in detail an optimized strategy that was applied for exposure of FZPs by the Vistec EBPG5000Plus e-beam lithography tool. Direct programming of exposure files allowed us to use fully the capabilities of this e-beam writer to expose efficiently and reproducibly FZPs with desired characteristics in both positive and negative tone resists.

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

    International Nuclear Information System (INIS)

    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

  2. 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)

    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)

  3. 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.

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

    International Nuclear Information System (INIS)

    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

  5. Evaluation of image quality and appropriate X-ray exposure of a flat panel detector

    International Nuclear Information System (INIS)

    We evaluated image quality and necessary patient exposure when using the CXDI-11 (Canon Inc.) flat panel detector (FPD). This detector, which consists of a rare earth fluorescent screen (Gd2O2S: Tb) and amorphous silicon sensor, was compared with the FCR-5000 (Fuji Film Medical Co., Ltd.) CR and the UR-3/HGM2 (Fuji Film Medical Co., Ltd.) film-screen (F/S) combination. Comparisons of both physical imaging characteristics and clinical image quality were carried out. The final MTF of the FPD was found to be similar to or better than those of the CR and F/S systems. For identical exposures, the overall Wiener spectrum of the FPD was found to be slightly poorer than that of the F/S combination. The NEQ of the FPD was found to be similar to or better than those of the CR and F/S systems. Comparison of chest images showed that the FPD produced images with quality comparable to or higher than those of the CR system. Similarly, evaluation of abdominal and bone images using a 5-scale method showed that the FPD produced images with quality comparable to or higher than those of the CR system. As with CR, the x-ray quantum mottle in FPD images becomes noticeable at low exposures. Clinical images were therefore taken with a 30% increase in exposure, giving a Wiener spectrum for the FPD images similar to that obtained with the F/S images. This is probably not a significant increase in exposure, given the improvement in image quality and increased ease of use provided by the CXDI system. Further, future improvements in hardware and image processing may allow images to be taken with the same exposure used for F/S images. Our evaluation of both image quality and x-ray exposure has therefore indicated the value of the FPD in the clinical environment. (author)

  6. Estimation of patient exposure dose in the X-ray diagnoses

    International Nuclear Information System (INIS)

    Fundamental concept to asses the patient dose and its calculating methods are explained for X-ray examinations like radiography, abdominal fluoroscopy and CT, from the technological aspect of radiological protection. Justification of medical exposure, optimization of its dose and assessment of absorbed dose in patients are essentially based on guides by ICRP, IAEA and ICRU, and their application to Japanese standard has been being conducted. The numerical dose determination (NDD) method has been widely used by calculating the patient entrance air kerma using parameters of the tube voltage, tube current-time product, distance from the focus to skin, total filtration and back scatter. Coefficients for NDD are obtained from the tube voltage and Al filtration of X-ray spectrum with an empirical formula. The add-in software (NDD-Modify) in MS-Excel later developed can conveniently give the rough patient dose and is utilized in such facilities as having no dosimeter. radiology information system (RIS) equipped in the X-ray machine displays the estimated patient dose by NDD base and the actual output dose before and after imaging, respectively. This NDD comes from standardized coefficients of parameters above for 5 x 5-30 x 30 cm irradiation sizes using their corresponding back scatter coefficients calculated by Monte Carlo techniques for modeled structures of the tube, multi-leaf diaphragm and water phantom, and has been also able to be applied in the personal computer (PC) with the software estimation of patient dose (EPD). The PC-based Monte Carlo program for calculating organ doses of patients undergoing medical X-ray examinations (PCXMC) of radiology and fluoroscopy is written with Delphi Object Pascal code; is composed from the photoelectric absorption, coherent and incoherent scatters; and widely used at present. imaging performance assessment of CT scanners (ImPACT) is the excel bookfile, usable to calculate the organ dose and effective dose. In future, patient

  7. An old/new idea for reducing exposure to x-rays

    International Nuclear Information System (INIS)

    In 1925 the patient's exposure to x-radiation was reduced 50 percent by the application of emulsion to both sides of the dental film. Another similar reduction is possible when the layers of emulsion are once again doubled. The authors have rediscovered this idea and tested it. A double film packet containing films which are hinged on one side for proper reorientation after developing was produced. The films were exposed to half the radiation given to normal packets. It was found that density, contrast, and definition were all comparable to normal exposures when allowances were made for an additional layer of blue-tinted film base. In addition to reduced exposure to x-rays, the folded-film technique gives a second view of the exposed area. An underexposed view is obtained by viewing either side of the folded film alone. This underexposed view offers some details not seen on fully exposed films

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

    International Nuclear Information System (INIS)

    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)

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

    International Nuclear Information System (INIS)

    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.)

  10. Direct X-ray radiogrammetry versus dual-energy X-ray absorptiometry: assessment of bone density in children treated for acute lymphoblastic leukaemia and growth hormone deficiency

    Energy Technology Data Exchange (ETDEWEB)

    Rijn, Rick R. van; Wittenberg, Rianne [Academic Medical Centre Amsterdam, Department of Radiology, Amsterdam Zuid-Oost (Netherlands); Boot, Annemieke; Sluis, Inge M. van der; MuinckKeizer-Schrama, Sabine M.P.F. de [Erasmus MC-Sophia Children' s Hospital, Department of Paediatric Endocrinology, Rotterdam (Netherlands); Heuvel-Eibrink, Marry M. van den [Erasmus MC-Sophia Children' s Hospital, Department of Paediatric Haematology/Oncology, Rotterdam (Netherlands); Lequin, Maarten H. [Erasmus MC-Sophia Children' s Hospital, Department of Paediatric Radiology, Rotterdam (Netherlands); Kuijk, Cornelis Van [University Medical Centre ' Radboud' , Department of Radiology, Nijmegen (Netherlands)

    2006-03-15

    In recent years interest in bone densitometry in children has increased. To evaluate the clinical application of digital X-ray radiogrammetry (DXR) and compare the results with those of dual-energy X-ray absorptiometry (DXA). A total of 41 children with acute lymphoblastic leukaemia (ALL) and 26 children with growth hormone deficiency (GHD) were included in this longitudinal study. Radiographs of the left hand were obtained and used for DXR. DXA of the total body and of the lumbar spine was performed. In both study populations significant correlations between DXR and DXA were found, and, with the exception of the correlation between DXR bone mineral density (DXR-BMD) and bone mineral apparent density in the GHD population, all correlations had a P-value of <0.001. During treatment a change in DXR-BMD was found in children with GHD. Our study showed that DXR in a paediatric population shows a strong correlation with DXA of the lumbar spine and total body and that it is able to detect a change in BMD during treatment. (orig.)

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

    International Nuclear Information System (INIS)

    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

  12. X-ray findings in roofers with long-term exposure to asbestos cement fine dusts

    International Nuclear Information System (INIS)

    In 404 roofers with long-term exposure of asbestos-cement fine dust we studied the possible fibrogenous effects on lung and pleura by chest radiographs. The standardfilm sets of the ILO U/C 1971 and ILO 80/BRD X-ray classification of pneumoconiosis were used. 410 non-asbestos-exposed craftsmen and workers of several industries served as control group. Roofers show in n = 58 cases (14,4%) significantly increased small irregular opacities of the size 's' and 't' with the profusion 1/0 (n = 53) and 1/1 (n = 5). Furthermore up to now, 3 cases of lung-cancer in our cohort have been occured. Our findings indicate the nessecity of further preventive measures on construction sites regarding the asbestos-cement problem. (orig.)

  13. X-ray findings in roofers with long-term exposure to asbestos cement fine dusts

    Energy Technology Data Exchange (ETDEWEB)

    Stauder, B.; Breuer, G.; Greven, U.; Woitowitz, R.H.; Roedelsperger, K.; Woitowitz, H.J.

    1982-11-01

    In 404 roofers with long-term exposure of asbestos-cement fine dust we studied the possible fibrogenous effects on lung and pleura by chest radiographs. The standardfilm sets of the ILO U/C 1971 and ILO 80/BRD X-ray classification of pneumoconiosis were used. 410 non-asbestos-exposed craftsmen and workers of several industries served as control group. Roofers show in n = 58 cases (14,4%) significantly increased small irregular opacities of the size 's' and 't' with the profusion 1/0 (n = 53) and 1/1 (n = 5). Furthermore up to now, 3 cases of lung-cancer in our cohort have occured. Our findings indicate the necessity of further preventive measures on construction sites regarding the asbestos-cement problem.

  14. Comparative study of spermatogonial survival after X-ray exposure, high LET (HZE) irradiation or spaceflight

    Science.gov (United States)

    Sapp, W. J.; Williams, C. S.; Williams, J. W.; Philpott, D. E.; Kato, K.; Miquel, J. M.; Serova, L.

    1992-01-01

    Spermatogonial cell loss has been observed in rats flown on Space Lab 3, Cosmos 1887, Cosmos 2044 and in mice following irradiation with X-ray or with HZE particle beams. Spermatogonial loss is determined by cell counting in maturation stage-6 seminferous tubules. With the exception of iron, laboratory irradiation experiments (with mice) revealed a similar pattern of spermatogonial loss proportional to the radiation dose at levels less than 0.1 Gy. Helium and argon irradiation resulted in a 5-percent loss of spermatogonia after only 0.01 Gy exposure. Significant spermatogonial loss (45 percent) occurred at this radiation level with iron particle beams. The loss of spermatogonia during each spaceflight was less than 10 percent when compared to control (nonflight) animals.

  15. Immediate screening of lead exposure in the workplace using portable X-ray fluorescence.

    Science.gov (United States)

    Gorce, Jean-Philippe; Roff, Martin

    2016-01-01

    The use of a portable X-ray fluorescence spectrometer (PXRF) equipped with a miniaturised X-ray tube producing a small 8 mm diameter X-ray beam required the validation of two new sampling protocols for the immediate screening of occupational lead exposure. First, lead in dust and fumes, collected by Institute of Occupational Medicine (IOM) inhalable samplers on 25 mm diameter membrane filters, is quantified using PXRF. To account for irregular dust deposition, the filters are rotated manually by quarter turns. Multiple PXRF readings are collected from the central region and from two locations in the outer region. The inner region is distinguishable from the outer region, but the two outer region locations are indistinguishable. High correlations (R(2) > 0.99) are found between the PXRF results and historical results obtained using a reference method based on a laboratory wavelength-dispersive sequential XRF instrument (WDXRF) for lead loadings between 1-161 μg. The PXRF results from the outer regions of the filters show a bias of -13% with respect to the WDXRF. Once this bias is allowed for, 95% of all PXRF results lie within -28% and +38% of the WDXRF results. Neither instrument accounts for potential dust accumulation on the walls of the IOM sampler. Therefore, methods based on their use can only be considered semi-quantitative. Second, a protocol combining direct PXRF measurements on workplace surfaces with surface wipes is designed for immediate on-site quantification of removable surface lead residues. The quantification of such residues by this method is compared with subsequent off-site wet chemistry analysis of the surface wipes. The two methods show a good correlation (R(2) ∼ 0.88). The ratio of the amount of removable residues determined by PXRF and wipe sampling is close to one with range 0.26-3.94. It is demonstrated that PXRF can be used as an effective tool for the immediate screening of occupational lead exposure. Although this article focused on

  16. Variations in film exposure, effective kVp, and HVL among thirty-five dental x-ray units

    International Nuclear Information System (INIS)

    Speed group ''E'' dental films were exposed in thirty-five dental x-ray units and processed under rigidly controlled conditions. The exposure, in milliroentgens required to produce an overall film density between 0.85 and 1.05 density units at the 9 mm. step of an aluminum step-wedge, ranged from 94 to 186 mR. The wide range in normalized exposure required to produce a standard density of 1.0 was associated with half-value layer and effective operating kilovoltage in only a general way. The half-value layer of thirty-five dental x-ray units ranged from 1.9 to 2.9 mm. Al, and their effective operating kilovoltages ranged from 62 to 77 kVp when units were set at 70 kVp. The exposure required to produce a specific radiographic density depended largely on the individual characteristics of the x-ray unit used

  17. Signal-to-noise and radiation exposure considerations in conventional and diffraction x-ray microscopy

    OpenAIRE

    Huang, Xiaojing; Miao, Huijie; Steinbrener, Jan; Nelson, Johanna; Shapiro, David; Stewart, Andrew; Turner, Joshua; Jacobsen, Chris

    2009-01-01

    Using a signal-to-noise ratio estimation based on correlations between multiple simulated images, we compare the dose efficiency of two soft x-ray imaging systems: incoherent brightfield imaging using zone plate optics in a transmission x-ray microscope (TXM), and x-ray diffraction microscopy (XDM) where an image is reconstructed from the far-field coherent diffraction pattern. In XDM one must computationally phase weak diffraction signals; in TXM one suffers signal losses due to the finite n...

  18. Raised D-dimer levels in acute sickle cell crisis and their correlation with chest X-ray abnormalities

    Directory of Open Access Journals (Sweden)

    Hassan, Imad S. A.

    2010-01-01

    Full Text Available Objective: Quantitation of D-dimer level during a sickling crisis and its correlation with other clinical abnormalities. Design: Prospective longitudinal study. Setting: Armed Forces Hospital, Southern Region, Kingdom of Saudi Arabia. Patients: Adult patients (12 years and older admitted acutely with a sickle cell crisis who consent to taking part in the study. Candidates may re-participate if they are readmitted with a further acute painful crisis. Results: 36 patients with homozygous sickle cell disease consented to take part in the study. D-dimer levels were raised in 31 (68.9% of 45 episodes of painful crisis of whom 13 had an abnormal chest X-ray. Of those with a normal chest X-ray only one patient had a raised D-dimer level: sensitivity of 92.3%, specificity 40.6%, positive predictive value 38.7% and negative predictive value of 92.9% for an abnormal chest X-ray. Conclusion: D-dimer levels are frequently raised during an acute painful crisis. A normal level has a high negative predictive value for an abnormal chest X-ray.

  19. Some points of the X-ray pattern of acute viral primary pneumonia caused by acute respiratory disease viruses

    International Nuclear Information System (INIS)

    An analysis is made of the results of the X-ray studies as well as of the virological and serological tests in 225 out-patients consulted in the first days of their complaints. A predominance of the viral (70.2%) over the viral-bacterial primary pneumonia is established. The acute viral primary pneumonia are caused mostly by single influenza viruses and more rarely - by single respiratory viruses; in the cases of combined influenza viruses influenza-influenza viruses prevail over the influenza-respiratory ones. The morphological changes in pneumonia due to isolated single influenza viruses involve mostly the interstitium and are projected on X-ray as patchy and stripped densities. The inflamatory changes in pneumonia caused by combined influenza viruses affect both ihe interstitium and the broncho-alveolar substrate of the lungs; they are manifested in two roentgenologic forms: creeping (migrating) and fusing (confluent). In viral-bacterial pneumonia the changes affect mostly the lobe. The right lung and the lower parts of the both lungs are affected in most cases. 5 figs., 21 refs

  20. 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

  1. Direct X-ray radiogrammetry versus dual-energy X-ray absorptiometry: assessment of bone density in children treated for acute lymphoblastic leukaemia and growth hormone deficiency

    NARCIS (Netherlands)

    R.R. van Rijn; A. Boot; R. Wittenberg; I.M. van der Sluis; M.M. van den Heuvel-Eibrink; M.H. Lequin; S.M.P.F. de Muinckkeizer-Schrama; C. van Kuijk

    2006-01-01

    Background: In recent years interest in bone densitometry in children has increased. Objective: To evaluate the clinical application of digital X-ray radiogrammetry (DXR) and compare the results with those of dual-energy X-ray absorptiometry (DXA). Materials and methods: A total of 41 children with

  2. 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...

  3. Breast cancer in women with x-ray exposure: models of dose, time, and host susceptibility

    International Nuclear Information System (INIS)

    Acute postpartum mastitis (APM) is an inflammatory/infectious condition of the breast, occurring commonly at childbirth or during lactation. A series of 600 women who received x-ray therapy for APM during the 1940s or 1950s have been followed up by mail questionnaire, with medical verification of pertinent conditions, to ascertain their incidence of breast cancer. The groups have been followed for up to 45 years, with an average of 29 years. The relative risk of breast cancer, adjusted for age and interval since irradiation (or an equivalent entry definition for controls) was 3.2 for the irradiated breasts. The dose-response curve appeared to be essentially linear, except for a diminution of risk at high doses (≥ 700 rad). The fact that there were no breasts with doses between zero and 50 rad, however, means it was not possible to evaluate the curvature with the maximum contrast between low and high doses. The dose fractionation analyses showed that the number of dose fractions or the number of days between fractions had no apparent effect upon breast cancer risk, but there was a suggestion that lower doses per fraction led to a higher risk, which runs counter to what one would expect based on radiobiological theory. However, a Cox regression analysis, controlling for total breast dose, did not yield a significant effect for any of the fractionation variables

  4. 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 ...... use of three-dimensional mapping systems to decrease X-ray radiation hazards. Digital fluoroscopy with decreased frame rate is not used by approximately one-third of responding centres....

  5. X-ray fluorescence imaging of the hippocampal formation after manganese exposure.

    Science.gov (United States)

    Robison, Gregory; Zakharova, Taisiya; Fu, Sherleen; Jiang, Wendy; Fulper, Rachael; Barrea, Raul; Zheng, Wei; Pushkar, Yulia

    2013-11-01

    Manganese (Mn) intoxication results in neurological conditions similar, but not identical, to idiopathic Parkinson's disease. While the mechanism(s) by which Mn exposure leads to neurotoxic effects remains unclear, studies by magnetic resonance imaging demonstrate a high Mn accumulation in the hippocampal formation (HPCf) of the brain. Metal quantification using this method is not possible. Using X-ray fluorescence imaging, we measured the distribution of Mn in the HPCf for a rodent model of chronic Mn exposure and quantitatively compared it with distributions of other biologically relevant metals. We found considerable increases in average Mn concentrations in all analyzed areas and we identified the dentate gyrus (DG) and the cornus ammonis 3 (CA3) layer as areas accumulating the highest Mn content (∼1.2 μg Mn per g tissue). The DG is significantly enriched with iron (Fe), while the CA3 layer has high zinc (Zn) content. Additionally, significant spatial correlations were found for Mn-Zn concentrations across the HPCf substructures and for Mn-Fe concentrations in the DG. Combined results support that at least two mechanisms may be responsible for Mn transport and/or storage in the brain, associated with either Fe or Zn. Subcellular resolution images of metal distribution in cells of the CA3 show diffuse Mn distributions consistent with Mn localization in both the cytoplasm and nucleus. Mn was not increased in localized intracellular Fe or copper accumulations. A consistent Mn-Zn correlation both at the tissue (40 μm × 40 μm) and cellular (0.3 μm × 0.3 μm) levels suggests that a Zn transport/storage mechanism in the HPCf is likely associated with Mn accumulation. PMID:23999853

  6. Dosimetric studies in children and adolescents using thermoluminescence dosemeters following radiation exposure from panoramic dental X-ray units

    International Nuclear Information System (INIS)

    For the determination of the somatic radiation exposure of children and adolescents by X-ray films with the status X panorama X-ray unit personal dosimetric measurements were carried out by means of thermoluminescence dosemeters (LiF and CaSO4) in 46 patients aged 7 to 16 years. The non-screen film 'ORWO TF 13' and the screen film 'ORWO TF 2' in connection with flexible intensifying screens were used. During the exposure the dosemeters were always fixed at the same measuring points being situated within or outside the mouth of the patient. The maximum radiation exposure was registered at those points where the transparent window of the hollow anode introduced into the mouth of the patient was directly opposite to the palatal and lingual, mucosa resp. With a maxillary or mandibular panorama film and the use of non-screen films doses of 60 to 80 mGy (6 - 8 rd) were determined. Using TF 2 screen films in connection with flexible intensifying screens the values for exposure time and radiation dose could be decreased by more than 50%. Basing on these results not only a strict indication but also the use of intensifying screens have to be required for the performance of radiodiagnostical examination with status X panorama X-ray units. (author)

  7. 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

  8. Selenium Preferentially Accumulates in the Eye Lens Following Embryonic Exposure: A Confocal X-ray Fluorescence Imaging Study

    Energy Technology Data Exchange (ETDEWEB)

    Choudhury, Sanjukta; Thomas, Jith; Sylvain, Nicole J.; Ponomarenko, Olena; Gordon, Robert A.; Heald, Steve M.; Janz, David M.; Krone, Patrick H.; Coulthard, Ian; George, Graham N.; Pickering, Ingrid J.

    2015-02-17

    Maternal transfer of elevated selenium (Se) to offspring is an important route of Se exposure for fish in the natural environment. However, there is a lack of information on the tissue specific spatial distribution and speciation of Se in the early developmental stages of fish, which provide important information about Se toxicokinetics. The effect of maternal transfer of Se was studied by feeding adult zebrafish a Se-elevated or a control diet followed by collection of larvae from both groups. Novel confocal synchrotron-based techniques were used to investigate Se within intact preserved larvae. Confocal X-ray fluorescence imaging was used to compare Se distributions within specific planes of an intact larva from each of the two groups. The elevated Se treatment showed substantially higher Se levels than the control; Se preferentially accumulated to highest levels in the eye lens, with lower levels in the retina, yolk and other tissues. Confocal X-ray absorption spectroscopy was used to determine that the speciation of Se within the eye lens of the intact larva was a selenomethionine-like species. Preferential accumulation of Se in the eye lens may suggest a direct cause-and-effect relationship between exposure to elevated Se and Se-induced ocular impairments reported previously. This study illustrates the effectiveness of confocal X-ray fluorescence methods for investigating trace element distribution and speciation in intact biological specimens

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

    International Nuclear Information System (INIS)

    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

  10. Dose assessment for medical exposure from diagnostic X-rays using a human voxel model

    International Nuclear Information System (INIS)

    Korean voxel model, KORMAN, segmented from whole-body MR data of an adult male, was used to calculate organ equivalent doses and effective doses due to diagnostic X-ray examinations. Calculated doses were normalized to entrance air kerma and compared with those derived using a stylized mathematical model, MIRD5. General purposed Monte Carlo code, MCNPX 2.3 was used for simulation of X-ray procedure. Korean voxel model picked up 0.048 Sv/Gy of effective dose per unit air kerma from a single chest PA examination, and 0.277 Sv/Gy from abdomen AP examination. These calculated results are higher than those MIRD5. The difference of effective doses between Korean voxel model and MIRD5 was within 32%, which were caused by significant discrepancies of organ equivalent doses between the two models. As MIRD5 is representing reference man, whereas KORMAN is segmented from specific individual MR data, it is recognized that variation among individuals could be significant for dose assessment in X-ray examination. Substantial differences in calculated doses between voxel and mathematical models suggested that existing mathematical models should be revised. (author)

  11. 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.

  12. Myeloid leukaemia frequency after protracted exposure to ionizing radiation: experimental confirmation of the flat dose-response found in ankylosing spondylitis after a single treatment course with x-rays

    Energy Technology Data Exchange (ETDEWEB)

    Mole, R.H.; Major, I.R. (Medical Research Council, Harwell (UK). Radiobiological Research Unit)

    1983-01-01

    The dose-response for leukaemia induction by exposure to ionizing radiation protracted over several weeks was largely independent of dose not only in X-rayed patients with ankylosing spondylitis but also in experimentally ..gamma..-rayed CBA/H mice. In the experiment the induced leukaemia frequency of acute myeloid leukaemia was independent of a several thousand-fold variation in physical dose rate. Any difference in leukaemia induction between brief and protracted exposures must therefore depend on specifically biological consequences of protracted exposures. Experimental analysis is required to provide the guides for inference about risks of low level exposure from observations on relatively heavily irradiated populations.

  13. X-ray equipment for dental diagnostics with a dose-rate controller influencing the exposure voltage

    International Nuclear Information System (INIS)

    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)

  14. Soft X-Ray Exposure Testing of FEP Teflon for the Hubble Space Telescope

    Science.gov (United States)

    deGroh, Kim K.

    1998-01-01

    The FEP Teflon (DuPont) multilayer insulation (MLI) thermal-control blanket material on the Hubble Space Telescope is degrading in the space environment. During the first Hubble servicing mission in 1993, after 3.6 years in low Earth orbit, aluminized and silvered FEP Teflon MLI thermal-control blanket materials were retrieved. These materials have been jointly analyzed by the NASA Lewis Research Center and the NASA Goddard Space Flight Center for degradation induced in the space environment (ref. 1). Solar-facing blanket materials were found to be embrittled with through-the-thickness cracking in the 5-mil FEP. During the second Hubble servicing mission in 1997, astronauts noticed that several blankets had large areas with tears. The torn FEP was curled up in some areas, exposing the underlying materials to the space environment. This tearing problem, and the associated curling up of torn areas, could lead to over-heating of the telescope and to particulate contamination. A Hubble Space Telescope MLI Failure Review Board was assembled by Goddard to investigate and identify the degradation mechanism of the FEP, to identify and characterize replacement materials, and to estimate the extent of damage at the time of the third servicing mission in 1999. A small piece of FEP retrieved during the second servicing mission is being evaluated by this failure review board along with materials from the first servicing mission. Since the first servicing mission, and as part of the failure review board, Lewis has been exposing FEP to soft x-rays to help determine the damage mechanisms of FEP in the space environment. Soft x-rays, which can penetrate into the bulk of FEP, are generated during solar flares and appear to be contributing to the degradation of the Hubble MLI.

  15. Studies on the radiation exposure and protection at the X-ray radiography in the medical care at home

    International Nuclear Information System (INIS)

    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.)

  16. Pulmonary complications of induction therapy for acute myeloid leukemia in adults. Findings of chest X-rays and computed tomography

    International Nuclear Information System (INIS)

    To exclude pulmonary complications, 359 chest radiographs and 50 computed tomographs of the lung were performed in 95 patients suffering from acute myeloid leukemia. The radiological findings were registered, described and correlated with clinical findings in the present study on 2395 days of observation. Results: In summary, 52 patients showed alterations of the lung. Pulmonary hyperhydration was seen in 21 cases, bacterial pneumonia was found in 18 cases, invasive pulmonary aspergillosis was documented in 14 cases, and 5 cases of severe haemorrhage were seen. An unexplained pulmonary edema in 13 patients with interstitial and alveolar infiltrates is considered to be a complication of treatment with cytosine-arabinoside. Conclusion: The results demonstrate that chest X-ray and computed tomography have a high impact in detection and treatment of pulmonary complications following intensive chemotherapy. We may expect the development of diffuse opacity following administration of cytosine-arabinoside in medium-sized doses. (orig.)

  17. Acute response of pig skin to irradiation with 12C-ions or 200 kV X-rays

    International Nuclear Information System (INIS)

    The acute response of pig skin to treatment with high energy carbon ions (plateau region) at the Gesellschaft fuer Schwerionenforschung (GSI, Darmstadt, Germany) was compared to changes after 200 kV X-irradiation. Carbon doses isoeffective to the X-ray doses were computed with a recently established model for calculation of the biological effect of heavy ions (1, 2). Clinical changes and physiological symptoms (blood flow, erythema, transepidermal water loss, skin hydration) were scored. The parameters analyzed were maximum and mean values of each symptom during days 24 to 70 post irradiation, and the quantal endpoints for the establishment of dose-effect curves were the median values of these. With exception of the maximum change in the red blood cell concentration (p12C-ions (plateau region) and may at least for epidermis be applied to treatment planning. (orig.)

  18. Chest X-ray findings in the acute phase of Kawasaki disease

    International Nuclear Information System (INIS)

    We reviewed the chest X-ray (CXR) findings and clinical courses of 129 patients with Kawasaki disease and found abnormal CXR findings in 14.7% of the patients. Reticulogranular pattern was the most frequent abnormality (89.5%), while peribronchial cuffing (21.1%), pleural effusion (15.8%), atelectasis (10.5%) and air trapping (5.3%) were also seen. In each of these patients, CXR abnormalities appeared within 10 days after the onset of illness. In the group with abnormal CXR findings, a statistically significant increase was noted in duration of fever, incidence of adventitious sounds, serum CPR levels and incidence of coronary arterial lesions and pericardial effusion, as compared with the group having normal CXR findings. The pathological basis of these CXR changes is not clear, since no biopsy or autopsy specimen was obtained from these patients. Since none of these patients showed definite heart failure, it is difficult to consider that abnormal CXR findings were due to heart failure. On the other hand, physical signs and previous pathological reports suggested that the causes of abnormal CXR findings were lower respiratory tract inflammation and/or pulmonary arteritis. (orig.)

  19. Characteristics of changes in the number of yH2AX and Rad51 protein foci in human skin fibroblasts after prolonged exposure to low-dose rate X-ray radiation

    Directory of Open Access Journals (Sweden)

    Ozerov I.V.

    2014-12-01

    Full Text Available Aim: to compare the repair process of DNA double-strand breaks in mammalian cells after acute versus prolonged exposure to X-ray irradiation with different dose rates. Material and methods. Studies were performed on primary human fibroblasts isolated from skin biopsies of healthy volunteers (women, 29 and 30 years. Cells were irradiated using an X-ray machine RUB RUST-M1 (JSC "Ruselectronics", Moscow, Russia at 37°C temperature with a dose rate of 400 mGy/min (200 kV, 2*2.4 mA, a filter of 1.5mm AI or 4 mGy/min (50 kV, 2*0.4 mA, a filter of 1.5 mm AI. Immuno-cytochemical protein staining was utilized for yH2AX and Rad51 foci analysis. Results. Phosphorylated histone H2AX (yH2AX and the key protein of homologous recombination Rad51 foci formation and disappearance kinetics were investigated simultaneously in primary human dermal fibroblasts after acute and prolonged exposure to X-ray radiation at a same dose. It was shown that the relative yield of yH2AX foci per dose reduces with decrease in dose rate, while the relative yield of Rad51 foci conversely increases. Conclusion. Our findings suggest the fundamental differences in the ratio of non-homologous end joining and homologous recombination DNA repair in acute versus prolonged irradiated cells.

  20. Analysis of settled dust with X-ray Fluorescence for exposure assessment of metals in the province of Brescia, Italy.

    Science.gov (United States)

    Zacco, Annalisa; Resola, Sergio; Lucchini, Roberto; Albini, Elisa; Zimmerman, Neil; Guazzetti, Stefano; Bontempi, Elza

    2009-09-01

    Ferroalloy industries have been active for more than a century in the province of Brescia, Northern Italy. Air emission and water discharge have contaminated the environment in the surroundings of four plants with several metals including manganese. The presence of manganese in this region is especially interesting, because of the observed relationship between manganese exposure and Parkinsonism in a previous epidemiological survey. The aim of this study was represented by an initial screening of metal exposure in this area, using a geographic information system. X-ray fluorescence (XRF) was applied to identify heavy metals in deposited dust samples, collected in representative residential households throughout the province. The results were interpreted through a systematic mapping of all municipal districts of the Brescia province. A more frequent distribution of manganese and other metals was observed in the municipalities where the plants were located and differences in the geochemical and anthropogenic origin of metals were discussed, according to the point sources. PMID:19724825

  1. An all-optical Compton source for single-exposure x-ray imaging

    Science.gov (United States)

    Döpp, A.; Guillaume, E.; Thaury, C.; Gautier, J.; Andriyash, I.; Lifschitz, A.; Malka, V.; Rousse, A.; Phuoc, K. Ta

    2016-03-01

    All-optical Compton sources are innovative, compact devices to produce high energy femtosecond x-rays. Here we present results on a single-pulse scheme that uses a plasma mirror to reflect the drive beam of a laser plasma accelerator and to make it collide with the highly-relativistic electrons in its wake. The accelerator is operated in the self-injection regime, producing quasi-monoenergetic electron beams of around 150 MeV peak energy. Scattering with the intense femtosecond laser pulse leads to the emission of a collimated high energy photon beam. Using continuum-attenuation filters we measure significant signal content beyond 100 keV and with simulations we estimate a peak photon energy of around 500 keV. The source divergence is about 13 mrad and the pointing stability is 7 mrad. We demonstrate that the photon yield from the source is sufficiently high to illuminate a centimeter-size sample placed 90 centimeters behind the source, thus obtaining radiographs in a single shot.

  2. 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.

  3. Mutation induction in haploid yeast after split-dose radiation exposure. II. Combination of UV-irradiation and X-rays.

    Science.gov (United States)

    Keller, B; Zölzer, F; Kiefer, J

    2004-01-01

    Split-dose protocols can be used to investigate the kinetics of recovery from radiation damage and to elucidate the mechanisms of cell inactivation and mutation induction. In this study, a haploid strain of the yeast, Saccharomyces cerevisiae, wild-type with regard to radiation sensitivity, was irradiated with 254-nm ultraviolet (UV) light and then exposed to X-rays after incubation for 0-6 hr. The cells were incubated either on nutrient medium or salt agar between the treatments. Loss of reproductive ability and mutation to canavanine resistance were measured. When the X-ray exposure immediately followed UV-irradiation, the X-ray survival curves had the same slope irrespective of the pretreatment, while the X-ray mutation induction curves were changed from linear to linear quadratic with increasing UV fluence. Incubations up to about 3 hr on nutrient medium between the treatments led to synergism with respect to cell inactivation and antagonism with respect to mutation, but after 4-6 hr the two treatments acted independently. Incubation on salt agar did not cause any change in the survival curves, but there was a strong suppression of X-ray-induced mutation with increasing UV fluence. On the basis of these results, we suggest that mutation after combined UV and X-ray exposure is affected not only by the induction and suppression of DNA repair processes, but also by radiation-induced modifications of cell-cycle progression and changes in the expression of the mutant phenotype.

  4. Evaluation of a novel portable x-ray fluorescence screening tool for detection of arsenic exposure.

    Science.gov (United States)

    McIver, David J; VanLeeuwen, John A; Knafla, Anthony L; Campbell, Jillian A; Alexander, Kevin M; Gherase, Mihai R; Guernsey, Judith R; Fleming, David E B

    2015-12-01

    A new portable x-ray fluorescence (XRF) screening tool was evaluated for its effectiveness in arsenic (As) quantification in human finger and toe nails ([Formula: see text]). Nail samples were measured for total As concentration by XRF and inductively coupled plasma-mass spectrometry (ICP-MS). Using concordance correlation coefficient (CCC), kappa, diagnostic sensitivity (Sn) and specificity (Sp), and linear regression analyses, the concentration of As measured by XRF was compared to ICP-MS. The CCC peaked for scaled values of fingernail samples, at 0.424 (95% CI: 0.065-0.784). The largest kappa value, 0.400 (95% CI:  -0.282-1.000), was found at a 1.3 μg g(-1) cut-off concentration, for fingernails only, and the largest kappa at a clinically relevant cut-off concentration of 1.0 μg g(-1) was 0.237 (95% CI:  -0.068-0.543), again in fingernails. Analyses generally showed excellent XRF Sn (up to 100%, 95% CI: 48-100%), but low Sp (up to 30% for the same analysis, 95% CI: 14-50%). Portable XRF shows some potential for use as a screening tool with fingernail samples. The difference between XRF and ICP-MS measurements decreased as sample mass increased to 30 mg. While this novel method of As detection in nails has shown relatively high agreement in some scenarios, this portable XRF is not currently considered suitable as a substitute for ICP-MS.

  5. Evaluation of a novel portable x-ray fluorescence screening tool for detection of arsenic exposure.

    Science.gov (United States)

    McIver, David J; VanLeeuwen, John A; Knafla, Anthony L; Campbell, Jillian A; Alexander, Kevin M; Gherase, Mihai R; Guernsey, Judith R; Fleming, David E B

    2015-12-01

    A new portable x-ray fluorescence (XRF) screening tool was evaluated for its effectiveness in arsenic (As) quantification in human finger and toe nails ([Formula: see text]). Nail samples were measured for total As concentration by XRF and inductively coupled plasma-mass spectrometry (ICP-MS). Using concordance correlation coefficient (CCC), kappa, diagnostic sensitivity (Sn) and specificity (Sp), and linear regression analyses, the concentration of As measured by XRF was compared to ICP-MS. The CCC peaked for scaled values of fingernail samples, at 0.424 (95% CI: 0.065-0.784). The largest kappa value, 0.400 (95% CI:  -0.282-1.000), was found at a 1.3 μg g(-1) cut-off concentration, for fingernails only, and the largest kappa at a clinically relevant cut-off concentration of 1.0 μg g(-1) was 0.237 (95% CI:  -0.068-0.543), again in fingernails. Analyses generally showed excellent XRF Sn (up to 100%, 95% CI: 48-100%), but low Sp (up to 30% for the same analysis, 95% CI: 14-50%). Portable XRF shows some potential for use as a screening tool with fingernail samples. The difference between XRF and ICP-MS measurements decreased as sample mass increased to 30 mg. While this novel method of As detection in nails has shown relatively high agreement in some scenarios, this portable XRF is not currently considered suitable as a substitute for ICP-MS. PMID:26536141

  6. Acute shoulder injury with a normal x-ray: a simple algorithm of patient assessment to guide the need for further imaging

    LENUS (Irish Health Repository)

    O’Rourke, S

    2012-09-20

    Purpose: Patients presenting to their General Practitioner or to the Emergency Department following an acute shoulder injury but a normal x-ray may have a significant underlying injury to the Rotator Cuff. Imaging (whether by ultrasound or MRI) is often indicated but available clinical evidence has yet to establish what group of patients benefit most from early imaging.\\r\

  7. Analysis of Flow Cytometry DNA Damage Response Protein Activation Kinetics Following X-rays and High Energy Iron Nuclei Exposure

    Energy Technology Data Exchange (ETDEWEB)

    Universities Space Research Association; Chappell, Lori J.; Whalen, Mary K.; Gurai, Sheena; Ponomarev, Artem; Cucinotta, Francis A.; Pluth, Janice M.

    2010-12-15

    We developed a mathematical method to analyze flow cytometry data to describe the kinetics of {gamma}H2AX and pATF2 phosphorylations ensuing various qualities of low dose radiation in normal human fibroblast cells. Previously reported flow cytometry kinetic results for these DSB repair phospho-proteins revealed that distributions of intensity were highly skewed, severely limiting the detection of differences in the very low dose range. Distributional analysis reveals significant differences between control and low dose samples when distributions are compared using the Kolmogorov-Smirnov test. Radiation quality differences are found in the distribution shapes and when a nonlinear model is used to relate dose and time to the decay of the mean ratio of phosphoprotein intensities of irradiated samples to controls. We analyzed cell cycle phase and radiation quality dependent characteristic repair times and residual phospho-protein levels with these methods. Characteristic repair times for {gamma}H2AX were higher following Fe nuclei as compared to X-rays in G1 cells (4.5 {+-} 0.46 h vs 3.26 {+-} 0.76 h, respectively), and in S/G2 cells (5.51 {+-} 2.94 h vs 2.87 {+-} 0.45 h, respectively). The RBE in G1 cells for Fe nuclei relative to X-rays for {gamma}H2AX was 2.05 {+-} 0.61 and 5.02 {+-} 3.47, at 2 h and 24-h postirradiation, respectively. For pATF2, a saturation effect is observed with reduced expression at high doses, especially for Fe nuclei, with much slower characteristic repair times (>7 h) compared to X-rays. RBEs for pATF2 were 0.66 {+-} 0.13 and 1.66 {+-} 0.46 at 2 h and 24 h, respectively. Significant differences in {gamma}H2AX and pATF2 levels comparing irradiated samples to control were noted even at the lowest dose analyzed (0.05 Gy) using these methods of analysis. These results reveal that mathematical models can be applied to flow cytometry data to uncover important and subtle differences following exposure to various qualities of low dose radiation.

  8. 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.

  9. Selective brain responses to acute and chronic low-dose X-ray irradiation in males and females

    International Nuclear Information System (INIS)

    Radiation exposure is known to have profound effects on the brain, leading to precursor cell dysfunction and debilitating cognitive declines [Nat. Med. 8 (2002) 955]. Although a plethora of data exist on the effects of high radiation doses, the effects of low-dose irradiation, such as ones received during repetitive diagnostic and therapeutic exposures, are still under-investigated [Am. J. Otolaryngol. 23 (2002) 215; Proc. Natl. Acad. Sci. USA 97 (2000) 889; Curr. Opin. Neurol. 16 (2003) 129]. Furthermore, most studies of the biological effects of ionizing radiation have been performed using a single acute dose, while clinically and environmentally relevant exposures occur predominantly under chronic/repetitive conditions. Here, we have used a mouse model to compare the effects of chronic/repetitive and acute low-dose radiation (LDR) exposure (0.5 Gy) to ionizing radiation on the brain in vivo. We examined the LDR effects on p42/44 MAPK (ERK1/ERK2), CaMKII, and AKT signaling-the interconnected pathways that have been previously shown to be crucial for neuronal survival upon irradiation. We report perturbations in ERK1/2, AKT, and CREB upon acute and chronic/repetitive low-dose exposure in the hippocampus and frontal cortex of mice. These studies were paralleled by the analysis of radiation effects on neurogenesis and cellular proliferation. Repetitive exposure had a much more pronounced effect on cellular signaling and neurogenesis than acute exposure. These results suggest that studies of single acute exposures might be limited in terms of their predictive value. We also present the first evidence of sex differences in radiation-induced signaling in the hippocampus and frontal cortex. We show the role of estrogens in brain radiation responses and discuss the implications of the observed changes

  10. Manifestations Analysis About the Acute Pyogenic Osteomyelitis By X-ray%急性化脓性骨髓炎X线表现分析

    Institute of Scientific and Technical Information of China (English)

    刘文辉

    2015-01-01

    ObjectiveTo study the X-ray imaging manifestations of the patients with acute pyogenic osteomyelitis.MethodsSelected 20 cases X-ray datum of the patients with acute pyogenic osteomyelitis to analyse from January 2012 to June 2014.Results The X-ray showed that there were 6 cases got intervertebral space stenosis, 2 cases got vertebral endplate failure and 12 cases got the destruction of vertebral bodies.Conclusion The skeletal positive X-ray signs of acute pyogenic osteomyelitis is displayed in the 10 days before onset, but the changes of the soft tissue will appear after 2 to 3 days when it onset. The X-ray examination with the advantages of convenient, simple, cheap, good effect and so on, and it still as the preferred method for diagnosis of acute suppurative osteomyelitis.%目的:探讨急性化脓性骨髓炎患者X线影像表现。方法选取2012年1月~2014年6月收治的急性化脓性骨髓炎患者20例X线检查资料进行分析。结果X线表现为椎间隙狭窄6例,椎体终板破坏2例,椎体破坏12例。结论急性化脓性骨髓炎的骨骼阳性X线征象需在发病10天后才能显示,但软组织的改变在发病后2~3天即可出现。X线检查以其方便、简单、便宜、效果良好等优点,仍作为诊断急性化脓性骨髓炎的首选方法。

  11. Early X-ray and CT appearances of severe acute respiratory syndrome:an analysis of 28 cases

    Institute of Scientific and Technical Information of China (English)

    赵大伟; 马大庆; 王微; 吴昊; 袁春旺; 贾翠宇; 贺文; 刘春红; 陈疆红

    2003-01-01

    Objective To study the early X-ray and CT findings of patients with severe acute respiratory syndrome ( SARS).Methods Chest radiography and CT were performed in 28 patients with SARS within one to three days after onset of the disease. CT examinations included conventional spiral CT and high-resolution CT (HRCT). The radiographic and CT findings of these patients were analyzed retrospectively.Results Abnormal CT findings were noted in all the patients, but abnormal chest radiographic findings in 17 cases (60.7%, 17/28). CT showed single small focal patchy opacities in 23 patients (82. 1%, 23/28), including oval ground-glass opacities in 20 patients, Iobular distribution groundglass opacities in 2 and small patchy consolidation in one. Multi-focal ground-glass opacities were found in 2 patients and extensive opacities in three. In the 28 patients, a total of 31 lesions were found in the upper (7, 22.6% ), middle (3, 9.7% ), and lower lobes (21,67.7%). The diameter of the lesions ranged from 20 to 35 mm.Conclusion The dominant feature of early SARS patients is focal patchy opacity in the lung, and oval small ground-glass opacities are the common morphological findings on CT.

  12. Hospital and clinic survey estimates of medical X-ray exposure in Hiroshima and Nagasaki, 2

    International Nuclear Information System (INIS)

    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)

  13. Changes of gene expression in developing mouse brain after exposures to x-rays, in comparison with exposures to accelerated heavy ion particles

    Energy Technology Data Exchange (ETDEWEB)

    Yaoi, Takeshi; Fushiki, Shinji [Kyoto Prefectural Univ. of Medicine, Dept. of Pathology and Applied Neurobiology, Kyoto (Japan); Nojima, Kumie [National Institute of Radiological Sciences, International Space Radiation Lab., Anagawa, Chiba (Japan)

    2003-07-01

    Prenatal exposure to ionizing radiation of low doses in rodents impedes neuronal migration during the period of cortical histogenesis, and results in disorganized cortical architecture in mature brain. On the contrary, exposure to heavy ion beams during fetal period mainly affects cell survival, viz., induction of apoptosis. However, the molecular mechanisms underlying to produce such difference in the effects between exposure to heavy particles and exposure to X-rays remain unknown. We have attempted to elucidate whether the changes of gene expression after exposure to heavy ions differ from those after X-irradiation in fetal brains. We thus applied two molecular biological techniques, i.e., the Restriction Landmark cDNA Scanning (RLCS) method and the suppression subtractive PCR method. Approximately 13,000 cDNA species were scanned and it turned out that more than twenty genes among the genes scanned were differentially expressed between X-irradiated embryos and non-irradiated ones. One of the genes showing up-regulation is Rab6A that is known to be associated with vesicle transport from trans-Golgi network. In addition, expression of some genes encoding RAB6A-interacting proteins was up-regulated. When expression of these genes was compared between animals after heavy-ion irradiation and those after X-irradiation, the changing pattern was different. Taking our previous observation that prenatal exposure to carbon particles induces apoptotic cell death in developing cerebral cortex into consideration, the difference in gene expression herein reported may contribute to better understand the difference in effects between exposures to heavy-ion particles and to X-rays. In conclusion, we identified Rab6A and its interacting proteins as candidates for the migration-associated genes, whose expression in fetal brain is up-regulated by carbon beam irradiation. (author)

  14. Fabrication of thin film x-ray sensor using particle-in-binder method for automatic exposure control in digital radiography

    International Nuclear Information System (INIS)

    An automatic exposure control (AEC) detector is a control device that ensures consistent x-ray image quality and limits patient exposure in digital radiography. Among several kinds of AEC detectors, solid-state sensors offer several advantages such as geometric efficiency due to small thickness, high sensitivity, fast reaction time, and excellent stability. Commercially, the use of single-crystal silicon sensors for AEC detector has grown over time, but is still severely limited by large-area production techniques and mechanically fragile properties. Therefore, our study focused on developing a method of fabricating solid-state sensors that do not suffer from these limitations. The particle-in-binder method was used to fabricate silicon dioxide-based photoconductor films. Because silicon dioxide has a low atomic number and a low work function, it is a suitable material for generating sufficient electron-hole pairs by incident x-rays as well as not negatively affect the image detector of the digital radiography. To verify the feasibility of the silicon dioxide film as an AEC detector, electrical properties such as x-ray transmission and x-ray linearity were measured and compared with those of a commercialized silicon film. Over 90% x-ray transmission was achieved using a 500 μ m silicon dioxide film, which is suitable for an AEC detector. Also, an error below 3% was obtained from both x-ray current and voltage linearity tests. The results of bending tests demonstrated the properties of the silicon dioxide film to be more mechanically strong and stable compared with the commercialized silicon film. These properties were a result of the use of binder materials, which resulted in the flexibility of the film

  15. Estimates of Average Glandular Dose with Auto-modes of X-ray Exposures in Digital Breast Tomosynthesis

    Directory of Open Access Journals (Sweden)

    Izdihar Kamal

    2015-05-01

    Full Text Available Objectives: The aim of this research was to examine the average glandular dose (AGD of radiation among different breast compositions of glandular and adipose tissue with auto-modes of exposure factor selection in digital breast tomosynthesis. Methods: This experimental study was carried out in the National Cancer Society, Kuala Lumpur, Malaysia, between February 2012 and February 2013 using a tomosynthesis digital mammography X-ray machine. The entrance surface air kerma and the half-value layer were determined using a 100H thermoluminescent dosimeter on 50% glandular and 50% adipose tissue (50/50 and 20% glandular and 80% adipose tissue (20/80 commercially available breast phantoms (Computerized Imaging Reference Systems, Inc., Norfolk, Virginia, USA with auto-time, auto-filter and auto-kilovolt modes. Results: The lowest AGD for the 20/80 phantom with auto-time was 2.28 milliGray (mGy for two dimension (2D and 2.48 mGy for three dimensional (3D images. The lowest AGD for the 50/50 phantom with auto-time was 0.97 mGy for 2D and 1.0 mGy for 3D. Conclusion: The AGD values for both phantoms were lower against a high kilovolt peak and the use of auto-filter mode was more practical for quick acquisition while limiting the probability of operator error.

  16. Cancer incidence rate after diagnostic X-ray exposure in 1976-2003 among patients of a university children's hospital

    International Nuclear Information System (INIS)

    Purpose: Although the carcinogenic effect of ionizing radiation is well known, knowledge gaps persist on the health effects of low-dose radiation, especially in children. The cancer incidence rate in a cohort of 92,957 children diagnosed using X-rays in the years 1976-2003 in the radiology department of a large university clinic was studied. Materials and Methods: Individual radiation doses per examination were reconstructed using an algorithm taking into account the dose area product and other exposure parameters together with conversion factors computed specifically for the equipment and protocols used in the radiology department. Incident cancer cases in the period 1980-2006 were identified via record linkage to the German Childhood Cancer Registry using pseudonymized data. Results: A total of 87 cancers occurred in the cohort between 1980 and 2006: 33 leukemia, 13 lymphoma, 10 brain tumors, and 31 other tumors. The standardized incidence ratio (SIR) for all cancers was 0.99 (95 % CI: 0.79 1.22). A dose-response relationship was not observed for all cancers, leukemia and lymphoma or solid tumors. The cancer risks for boys and girls did not differ. Conclusion: No increase in the cancer incidence risk in relation to very low doses of diagnostic ionizing radiation was observed in this study. However, the results are compatible with a broad range of risk estimates. (orig.)

  17. Exposure values in routine and additional X-ray methods of exploration of the facial-maxillary area

    International Nuclear Information System (INIS)

    Thirty types of measurements on skeletalized paraffin modelled skulls were attempted in an X-ray study in classical projections on ''TUR 1000'' and ''Hofmann-SR-700D'' apparatuses, using standard dosimeter VA-I-18. Standard data of anode tension current power and exposure time were selected. When roentgen tube regime was changed, radiation loading diminished with increasing the radiation hardness. Normal roentgenograms were taken at a focus-object distance of 0.50 m and 1 m, the directly magnified ones - at 0.52 m and 0.75 m with precision focus (0.3x0.3 mm) and the tomograms - at a minimal distance of 1.25 m and a maximal one of 1.40 m. Measurements were performed without filter and with additional filtration: 1.5 mm and 3 mm aluminium. The integral superficial doses obtained with the additional radiological exploration, especially from the directly magnified films, were almost the same as with the routine roentgenograms. Because of the use of deep anti-diffuser diaphragms with light view-finder, additional radiation filtration and selection of optimal technical data, the dose were smaller than those published in the literature and the tentative ones, indicated in the reports of the Research Committee of the UNO in 1962 and 1972. (author)

  18. X-Rays

    Science.gov (United States)

    X-rays are a type of radiation called electromagnetic waves. X-ray imaging creates pictures of the inside of ... different amounts of radiation. Calcium in bones absorbs x-rays the most, so bones look white. Fat ...

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

    Directory of Open Access Journals (Sweden)

    Zarko Barjaktarovic

    Full Text Available BACKGROUND: 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. METHODOLOGY/PRINCIPAL FINDINGS: 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. CONCLUSION/SIGNIFICANCE: 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

  20. Dose-response relationship of γ-H2AX foci induction in human lymphocytes after X-rays exposure

    International Nuclear Information System (INIS)

    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 (R2 = 0.99), Y(5h) = 2.44D + 0.15 (R2 = 0.99), Y(8h) = 1.57D + 0.22 (R2 = 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.

  1. 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.

  2. Assessment of targeted and non-targeted responses in cells deficient in ATM function following exposure to low and high dose X-rays.

    Science.gov (United States)

    Kiuru, Anne; Kämäräinen, Meerit; Heinävaara, Sirpa; Pylkäs, Katri; Chapman, Kim; Koivistoinen, Armi; Parviainen, Teuvo; Winqvist, Robert; Kadhim, Munira; Launonen, Virpi; Lindholm, Carita

    2014-01-01

    Radiation sensitivity at low and high dose exposure to X-rays was investigated by means of chromosomal aberration (CA) analysis in heterozygous ATM mutation carrier and A-T patient (biallelic ATM mutation) lymphoblastoid cell lines (LCLs). Targeted and non-targeted responses to acutely delivered irradiation were examined by applying a co-culture system that enables study of both directly irradiated cells and medium-mediated bystander effects in the same experimental setting. No indication of radiation hypersensitivity was observed at doses of 0.01 Gy or 0.1 Gy for the ATM mutation carrier LCL. The A-T patient cells also did not show low-dose response. There was significant increase in unstable CA yields for both ATM mutation carrier and A-T LCLs at 1 and 2 Gy, the A-T cells displaying more distinct dose dependency. Both chromosome and chromatid type aberrations were induced at an increased rate in the irradiated A-T cells, whereas for ATM carrier cells, only unstable chromosomal aberrations were increased above the level observed in the wild type cell line. No bystander effect could be demonstrated in any of the cell lines or doses applied. Characteristics typical for the A-T cell line were detected, i.e., high baseline frequency of CA that increased with dose. In addition, dose-dependent loss of cell viability was observed. In conclusion, CA analysis did not demonstrate low-dose (≤100 mGy) radiosensitivity in ATM mutation carrier cells or A-T patient cells. However, both cell lines showed increased radiosensitivity at high dose exposure.

  3. Assessment of targeted and non-targeted responses in cells deficient in ATM function following exposure to low and high dose X-rays.

    Directory of Open Access Journals (Sweden)

    Anne Kiuru

    Full Text Available Radiation sensitivity at low and high dose exposure to X-rays was investigated by means of chromosomal aberration (CA analysis in heterozygous ATM mutation carrier and A-T patient (biallelic ATM mutation lymphoblastoid cell lines (LCLs. Targeted and non-targeted responses to acutely delivered irradiation were examined by applying a co-culture system that enables study of both directly irradiated cells and medium-mediated bystander effects in the same experimental setting. No indication of radiation hypersensitivity was observed at doses of 0.01 Gy or 0.1 Gy for the ATM mutation carrier LCL. The A-T patient cells also did not show low-dose response. There was significant increase in unstable CA yields for both ATM mutation carrier and A-T LCLs at 1 and 2 Gy, the A-T cells displaying more distinct dose dependency. Both chromosome and chromatid type aberrations were induced at an increased rate in the irradiated A-T cells, whereas for ATM carrier cells, only unstable chromosomal aberrations were increased above the level observed in the wild type cell line. No bystander effect could be demonstrated in any of the cell lines or doses applied. Characteristics typical for the A-T cell line were detected, i.e., high baseline frequency of CA that increased with dose. In addition, dose-dependent loss of cell viability was observed. In conclusion, CA analysis did not demonstrate low-dose (≤100 mGy radiosensitivity in ATM mutation carrier cells or A-T patient cells. However, both cell lines showed increased radiosensitivity at high dose exposure.

  4. Assessment of occupational exposure to manganese and other metals in welding fumes by portable X-ray fluorescence spectrometer.

    Science.gov (United States)

    Laohaudomchok, Wisanti; Cavallari, Jennifer M; Fang, Shona C; Lin, Xihong; Herrick, Robert F; Christiani, David C; Weisskopf, Marc G

    2010-08-01

    Elemental analysis of welding fume samples can be done using several laboratory-based techniques. However, portable measurement techniques could offer several advantages. In this study, we sought to determine whether the portable X-ray fluorescence spectrometer (XRF) is suitable for analysis of five metals (manganese, iron, zinc, copper, and chromium) on 37-mm polytetrafluoroethylene filters. Using this filter fitted on a cyclone in line with a personal pump, gravimetric samples were collected from a group of boilermakers exposed to welding fumes. We assessed the assumption of uniform deposition of these metals on the filters, and the relationships between measurement results of each metal obtained from traditional laboratory-based XRF and the portable XRF. For all five metals of interest, repeated measurements with the portable XRF at the same filter area showed good consistency (reliability ratios are equal or close to 1.0 for almost all metals). The portable XRF readings taken from three different areas of each filter were not significantly different (p-values = 0.77 to 0.98). This suggested that the metal rich PM(2.5) deposits uniformly on the samples collected using this gravimetric method. For comparison of the two XRFs, the results from the portable XRF were well correlated and highly predictive of those from the laboratory XRF. The Spearman correlation coefficients were from 0.325 for chromium, to 0.995 for manganese and 0.998 for iron. The mean differences as a percent of the mean laboratory XRF readings were also small (XRF for many of the samples. These five metals were moderately to strongly correlated with the total fine particle fraction on filters (Spearman rho = 0.41 for zinc to 0.97 for iron). Such strong correlations and comparable results suggested that the portable XRF could be used as an effective and reliable tool for exposure assessment in many studies. PMID:20526948

  5. Radioresistant cell strain of human fibrosarcoma cells obtained after long-term exposure to X-rays

    International Nuclear Information System (INIS)

    A radioresistant cell strain from human fibrosarcoma HT1080 has been obtained after prolonged exposure to x-rays for 7 months (2 Gy per day, 5 days per week). This new strain, HT1080R, differs from HT1080 in a significantly increased ability of clonogenical survival, with coefficient α decreasing from 0.161 to 0.123 Gy-1 and coefficient β decreasing from 0.0950 to 0.0565 Gy-2. Furthermore, the radioresistance of HT1080R proved to be stable in long-term passaged cultures as well as in frozen samples. Differences between the two cell lines are also observed in the G-banded karyotype; the new cell line shows monosomy of chromosome 17 and loss of 5p+ and 11q+ present in the parental cells. These data suggest that the radioresistance may have been caused by radiation-induced cell mutation and that the resistant cells may have been selected by repeated irradiations. In order to characterize this new strain, the ability of the cells to rejoin DNA double-strand breaks, the cell cycle distribution and the amount of apoptosis after irradiation have been estimated; however, no differences are observed between these two cell strains. Although the mechanism of the elevated radioresistance remains unknown, this pair of cell strains can provide a new model system for further investigations with regard to the mechanisms of cellular radioresistance. The results also show that any type of irradiation similar to the schedules used in radiotherapy can lead to the formation and selection of more radioresistant cell clones in vitro, a phenomenon with possible implications for radiotherapy. (orig.)

  6. Comparison of Clinical and Laboratory Responses in Sheep and Dogs following Whole-Body Exposures to 250-Kvp X-Rays and Fission-Spectrum Neutrons

    International Nuclear Information System (INIS)

    Fifteen sheep and eight dogs were exposed to 400 rad (air dose) of pulsed fission-spectrum neutrons, and an equal number of sheep and 14 dogs to 400 r (midline air dose) 250 kVp X-rays. Seven additional sheep and four dogs served as un-irradiated controls. Control data were obtained for two weeks preceding the exposures and at frequent and regular intervals after the injury. In sheep, the most consistent clinical change was complete loss of wool by the 51st day post-exposure. The underlying skin was pink in colour closely resembling that of a mild blush sometimes noted in humans. Dogs did not demonstrate loss of hair. Formed blood elements, neutrophils, lymphocytes, and thrombocytes fell rapidly after the radiation in both species. At about post-exposure day 24 recovery in white cell numbers was noted only in the neutron groups. Thrombocyte levels decreased to safe level in both species but somewhat earlier in the dog. Recovery appeared during the third post-exposure week in both species ex posed to neutrons, but not in those given X-rays. Red blood-cell haematocrits showed significant drops in both groups of dogs by the ninth day, but neither group of sheep exhibited significant decrease in haematocrit values. Plasma Fe59 clearance rates were determined in the experimental subjects as a parameter of measurement of haematopoietic function. Prognostic implications of alteration in this parameter of haemapoiesis are discussed. The most significant gross-pathologic changes were confined to the lungs wherein extensive perivascular haemorrhage around the arteries was noted. On microscopic study the area of haemorrhage was observed to be within the advential-connective tissue and periarterial vessels. Thirty-day mortality for dogs was 50% following neutron exposures and 93% after the X-ray insult. In sheep neutrons produced 22% mortality and X-rays 80%. (author)

  7. Chest x-ray

    Science.gov (United States)

    Chest radiography; Serial chest x-ray; X-ray - chest ... You stand in front of the x-ray machine. You will be told to hold your breath when the x-ray is taken. Two images are usually taken. You will ...

  8. Influence of occupational exposure to pesticides on the level of DNA damage induced in human lymphocytes (Polish group) by UV-C and X-rays

    International Nuclear Information System (INIS)

    The aim of this study was to find out whether occupational exposure to pesticides might affect the individual susceptibility of various donors to the induction of DNA damage by genotoxic agents (UV-C, X-rays) and the efficiency of cellular repair. Previously cryo preserved lymphocytes were defrosted, and DNA damage in the lymphocytes prior to any in vitro studies was investigated with the application of the Comet assay. In order to evaluate the susceptibilities of human lymphocytes to genotoxic agents and the variability of repair capacities, the DNA migrations were estimated immediately after exposure to UV-C light or X-rays and after two hours. On average, the DNA damage detected in untreated lymphocytes was significantly higher in the group exposed to pesticides than in reference group. UV-C treated lymphocytes from group exposed to pesticides shows a greater statistically significant level of DNA migration compared to the reference group, detected after 2 hours incubation in the absence of PHA. Significantly lower responses to X-rays and higher levels of residual DNA damage were detected in the lymphocytes of donors from the group exposed to pesticides compared with the reference group. In conclusion, our results suggest that occupational exposure to pesticides influences the level of induced DNA damage, and the cellular capabilities of repair. (author)

  9. Low energy (soft) x rays

    International Nuclear Information System (INIS)

    Dosimetry of low-energy (soft) X rays produced by the SOFTEX Model CMBW-2 was performed using Nuclear Associates Type 30 - 330 PTW, Exradin Type A2, and Shonka-Wyckoff ionization chambers with a Keithley Model 602 electrometer. Thermoluminescent (BeO chip) dosimeters were used with a Harshaw Detector 2000-A and Picoammeter-B readout system. Beam quality measurements were made using aluminum absorbers; exposure rates were assessed by the current of the X-ray tube and by exposure times. Dose distributions were established, and the average factors for non-uniformity were calculated. The means of obtaining accurate absorbed and exposed doses using these methods are discussed. Survival of V79 cells was assessed by irradiating them with soft X rays, 200 kVp X rays, and 60Co gamma rays. The relative biological effectiveness (RBE) values for soft X rays with 0, 0.2, 0.7 mm added thicknesses of aluminum were 1.6, which were compared to 60Co. The RBE of 200 kVp X rays relative to 60Co was 1.3. Results of this study are available for reference in future RERF studies of cell survival. (author)

  10. Comparative whole-body and part measurements for professional exposure to X-rays in dentists and their personnel

    International Nuclear Information System (INIS)

    In 85 per cent of all dentists and 94 per cent of their ponnel radiation doses received are smaller than 1/100 of the legally admissible dose. If the prescriptions for radiation protection are observed, neither professional group will be unduly exposed to X-rays. (orig.)

  11. Thoracic spine x-ray

    Science.gov (United States)

    Vertebral radiography; X-ray - spine; Thoracic x-ray; Spine x-ray; Thoracic spine films; Back films ... care provider's office. You will lie on the x-ray table in different positions. If the x-ray ...

  12. Effect of 5-azacytidine and acute X-ray irradiation on mice during sexual differentiation in utero

    International Nuclear Information System (INIS)

    Treatment for mice on the 12th day of gestation with 2 mg azazytidine/kg before or after 2 Gy X-ray-treatment led to a high-grade hypoplasia of the fetal telencephalon. In order to clarify reasons for the organ-specific effect of the combined treatment the author presently investigates - in addition to the CNS - the development of the testicles and observes the results of prenatal damages on fertility. Results obtained so far are discussed. (orig./MG)

  13. Assessment of Occupational Exposure to Manganese and Other Metals in Welding Fumes by Portable X-ray Fluorescence Spectrometer

    OpenAIRE

    Laohaudomchok, Wisanti; Cavallari, Jennifer M.; Fang, Shona C; Lin, Xihong; Herrick, Robert F.; Christiani, David C; Weisskopf, Marc G.

    2010-01-01

    Elemental analysis of welding fume samples can be done using several laboratory-based techniques. However, portable measurement techniques could offer several advantages. In this study, we sought to determine whether the portable X-ray fluorescence spectrometer (XRF) is suitable for analysis of five metals (manganese, iron, zinc, copper, and chromium) on 37-mm polytetrafluoroethylene filters. Using this filter fitted on a cyclone in line with a personal pump, gravimetric samples were collecte...

  14. Emission of parasitic X-rays from military radar transmitters and exposure of personnel: towards a retrospective assessment

    Energy Technology Data Exchange (ETDEWEB)

    Schirmer, A. [Arbeitsgruppe Aufklarung der Arbeitsplatzverhaltnisse Radar, Wehrbereichsverwaltung Nord, Bundeswehr, Munster (Germany)

    2006-07-01

    An overview of the investigation of parasitic-X-ray (Bremsstrahlung) from high-voltage electron vacuum tubes in military radar transmitters is given. From technical inspection, data evaluation and measurements maximum dose rates for work places of the personnel are calculated. With dedicated workplace surveys the maximum dose H{sup *}(10) per month for the personnel is estimated for the entire time of use of the different radar sets. (author)

  15. Structural and histochemical considerations of parotid gland from adult rats (Holtzmann) submitted to x-rays exposure

    International Nuclear Information System (INIS)

    A histomorphological and histochemical study of the parotid gland of adult rats was carried out after subjecting the animals to a single X-ray irradiation dose of 900 R directed to the cervical region. The samples for the histological analysis were obtained at 2, 7, 15, 21, 30 and 45 days after radiation through desiccation and removal of the glands. The results showed clearly that the parotid gland is quite sensitive to X-ray irradiation with the serous acinar cells presenting heavier injuries than the mucous ones. A maximum in the deleterial action of the irradiation was detected at 15 days during the observation period. A comparative analysis of the glandular ducts showed that both of the types intercalated and striated were damaged, with the last presenting severe alterations in morphology and volume. By interpretation of the histochemical results it was concluded that a reduction in protein metabolism of the parotid gland occurred as a consequence of the X-ray irradiation. (author)

  16. X-ray (image)

    Science.gov (United States)

    X-rays are a form of ionizing radiation that can penetrate the body to form an image on ... will be shades of gray depending on density. X-rays can provide information about obstructions, tumors, and other ...

  17. Dental x-rays

    Science.gov (United States)

    X-ray - teeth; Radiograph - dental; Bitewings; Periapical film; Panoramic film ... dentist's office. There are many types of dental x-rays. Some are: Bitewing Periapical Palatal (also called occlusal) ...

  18. X-ray apparatus

    International Nuclear Information System (INIS)

    A diagnostic x-ray device, readily convertible between conventional radiographic and tomographic operating modes, is described. An improved drive system interconnects and drives the x-ray source and the imaging device through coordinated movements for tomography

  19. Dental x-rays

    Science.gov (United States)

    X-ray - teeth; Radiograph - dental; Bitewings; Periapical film; Panoramic film; Digital image ... dentist's office. There are many types of dental x-rays. Some of them are: Bitewing. Shows the crown ...

  20. Immunohistochemical study on cellular origins of rat lung tumors induced by inhalation exposures to plutonium dioxide aerosols as compared to those by X-ray irradiation

    International Nuclear Information System (INIS)

    Immunohistochemical examinations were performed on rat pulmonary tumors induced by inhalation exposures to 239PuO2 aerosols, or by X-ray-irradiation to identify and compare cellular origins or, in turn, target cells at risk for radiation carcinogenesis. Both plutonium-induced and X-ray-induced pulmonary tumors appeared to occur from the lower respiratory tract epithelium through bronchioles into alveoli, and were histopathologically diagnosed as adenoma, adenocarcinoma, adenosquamous carcinoma, and squamous cell carcinoma. Immunohistochemical staining of neoplastic lesions using rabbit polyclonal antibodies to rat surfactant apoprotein A specific for alveolar type II pneumocytes, and Clara cell antigen specific for nonciliated bronchiolar Clara cells, showed that most of the adenomatous and adenocarcinomatous lesions from plutonium-exposed or X-irradiated rats were positive for either or both antigens, while, in contrast, adenosquamous and squamous lesions were mostly negative for both antigens. Even though there were some differences in the proportions and distributions of immunoreactive cells between plutonium- and X-ray-induced tumors and among neoplastic lesions, the results indicate that radiation-induced pulmonary adenomas and adenocarcinomas mostly originate from either alveolar type II pneumocytes or bronchiolar Clara cells, while adenosquamous and squamous carcinomas may be derived from the other epithelial cell components, or might have lost specific antigenicity during their transforming differentiation. (author)

  1. Single-exposure low-dose x-ray imaging with grid-less and grid (GLG) imaging plates. A Kalman-filter approach

    Energy Technology Data Exchange (ETDEWEB)

    Zoroofi, R.A.; Ogata, Yuji; Sato, Yoshinobu; Tamura, Shinichi; Inamoto, Kazuo [Osaka Univ. (Japan). Faculty of Medicine; Taketani, Hisashi; Shimojo, Shinji

    1998-11-01

    The present study was designed to monitor novel ideas in the acquisition and manipulation of data in an X-ray imaging system. A grid was sandwiched between two cascaded imaging plates (IPs). Using a fan-beam X-ray tube and a single exposure scheme, the two IPs, respectively, recorded grid-less and grid (GLG) type information of the object. Referring to the mathematical model of the GLG technique, it was explained that the collected data associated with the grid-less IP was of high (S/N) together with large scattered components whereas that of IP with grid was of low (S/N) and suppressed scattered components. Based on this assumption and using a Gaussian convolution kernel representing the effect of scattering, a technique was proposed to estimate scatter parameters of the GLG plates. Then, a Kalman-filter was developed to restore noisy-blurred images of the GLG techniques using the IPs data and estimated parameters. The results are shown for both the computer simulated and real X-ray phantom data. (author)

  2. Immunohistochemical study on cellular origins of rat lung tumors induced by inhalation exposures to plutonium dioxide aerosols as compared to those by X-ray irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Oghiso, Yoichi; Yamada, Yutaka [National Inst. of Radiological Sciences, Chiba (Japan)

    2002-09-01

    Immunohistochemical examinations were performed on rat pulmonary tumors induced by inhalation exposures to {sup 239}PuO{sub 2} aerosols, or by X-ray-irradiation to identify and compare cellular origins or, in turn, target cells at risk for radiation carcinogenesis. Both plutonium-induced and X-ray-induced pulmonary tumors appeared to occur from the lower respiratory tract epithelium through bronchioles into alveoli, and were histopathologically diagnosed as adenoma, adenocarcinoma, adenosquamous carcinoma, and squamous cell carcinoma. Immunohistochemical staining of neoplastic lesions using rabbit polyclonal antibodies to rat surfactant apoprotein A specific for alveolar type II pneumocytes, and Clara cell antigen specific for nonciliated bronchiolar Clara cells, showed that most of the adenomatous and adenocarcinomatous lesions from plutonium-exposed or X-irradiated rats were positive for either or both antigens, while, in contrast, adenosquamous and squamous lesions were mostly negative for both antigens. Even though there were some differences in the proportions and distributions of immunoreactive cells between plutonium- and X-ray-induced tumors and among neoplastic lesions, the results indicate that radiation-induced pulmonary adenomas and adenocarcinomas mostly originate from either alveolar type II pneumocytes or bronchiolar Clara cells, while adenosquamous and squamous carcinomas may be derived from the other epithelial cell components, or might have lost specific antigenicity during their transforming differentiation. (author)

  3. X-Rays

    Science.gov (United States)

    X-rays are a type of radiation called electromagnetic waves. X-ray imaging creates pictures of the inside of your ... different amounts of radiation. Calcium in bones absorbs x-rays the most, so bones look white. Fat and ...

  4. Chest X-Ray

    Medline Plus

    Full Text Available ... by: Image/Video Gallery Your radiologist explains chest x-ray. Transcript Welcome to Radiology Info dot org! Hello, ... you about chest radiography also known as chest x-rays. Chest x-rays are the most commonly performed ...

  5. X-Ray Imaging

    Science.gov (United States)

    ... Brain Surgery Imaging Clinical Trials Basics Patient Information X-Ray Imaging Print This Page X-ray imaging is perhaps the most familiar type of imaging. Images produced by X-rays are due to the different absorption rates of ...

  6. X-ray spot film device

    International Nuclear Information System (INIS)

    Improvements are described in an X-ray spot film device which is used in conjunction with an X-ray table to make a selected number of radiographic exposures on a single film and to perform fluoroscopic examinations. To date, the spot film devices consist of two X-ray field defining masks, one of which is moved manually. The present device is more convenient to use and speeds up the procedure. (U.K.)

  7. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... over time. top of page What are the benefits vs. risks? Benefits Bone x-rays are the fastest and easiest ... cancer from excessive exposure to radiation. However, the benefit of an accurate diagnosis far outweighs the risk. ...

  8. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... for more information about pregnancy and x-rays. A Word About Minimizing Radiation Exposure Special care is ... encourage linking to this site. × Recommend RadiologyInfo to a friend Send to (friend's e-mail address): From ( ...

  9. Angular correlation functions of X-ray point-like sources in the full exposure XMM-LSS field

    CERN Document Server

    Elyiv, A; Plionis, M; Surdej, J; Pierre, M; Basilakos, S; Chiappetti, L; Gandhi, P; Gosset, E; Melnyk, O; Pacaud, F

    2011-01-01

    Our aim is to study the large-scale structure of different types of AGN using the medium-deep XMM-LSS survey. We measure the two-point angular correlation function of ~ 5700 and 2500 X-ray point-like sources over the ~ 11 sq. deg. XMM-LSS field in the soft (0.5-2 keV) and hard (2-10 keV) bands. For the conversion from the angular to the spatial correlation function we used the Limber integral equation and the luminosity-dependent density evolution model of the AGN X-ray luminosity function. We have found significant angular correlations with the power-law parameters gamma = 1.81 +/- 0.02, theta_0 = 1.3" +/- 0.2" for the soft, and gamma = 2.00 +/- 0.04, theta_0 = 7.3" +/- 1.0" for the hard bands. The amplitude of the correlation function w(theta) is higher in the hard than in the soft band for f_x < 10^-14 erg s^-1 cm^-2 and lower above this flux limit. We confirm that the clustering strength theta_0 grows with the flux limit of the sample, a trend which is also present in the amplitude of the spatial corre...

  10. Dental X-ray apparatus

    International Nuclear Information System (INIS)

    Intra-oral X-ray apparatus which reduces the number of exposures necessary to obtain panoramic dental radiographs is described in detail. It comprises an electron gun, a tubular target carrier projecting from the gun along the beam axis and carrying at its distal end a target surrounded by a shield of X-ray opaque material. This shield extends forward and laterally of the target and has surfaces which define a wedge or cone-shaped radiation pattern delimited vertically by the root tips of the patient's teeth. A film holder is located externally of the patient's mouth. A disposable member can fit on the target carrier to depress the patient's tongue out of the radiation pattern and to further shield the roof of the mouth. The electron beam can be magnetically deflected to change the X-ray beam direction. (author)

  11. X-ray devices contributing to sophistication of X-ray diagnostic systems

    International Nuclear Information System (INIS)

    X-ray tubes to generate X-rays, as well as X-ray image intensifiers (I.I.s) and X-ray flat panel detectors (FPDs) to convert X-ray images into electronic signals, are key devices in X-ray diagnostic systems, which are playing a major role in the advancement of diagnosis and treatment. Toshiba Electron Tubes and Devices Co., Ltd. has been offering optimal products incorporating the most advanced technologies to customers through continuous technological innovations. These include a high-sensitivity technology for X-ray I.I.s and X-ray FPDs to suppress patient exposure doses, a focal spot design technology for X-ray tubes and high-resolution technologies for X-ray I.I.s and X-ray FPDs that enhance image quality and make it possible to detect smaller lesion areas, and a noise reduction technology for X-ray tubes to realize a comfortable medical environment with reduced stress on both patients and medical staff. (author)

  12. X-Ray Polarimetry

    CERN Document Server

    Kaaret, Philip

    2014-01-01

    We review the basic principles of X-ray polarimetry and current detector technologies based on the photoelectric effect, Bragg reflection, and Compton scattering. Recent technological advances in high-spatial-resolution gas-filled X-ray detectors have enabled efficient polarimeters exploiting the photoelectric effect that hold great scientific promise for X-ray polarimetry in the 2-10 keV band. Advances in the fabrication of multilayer optics have made feasible the construction of broad-band soft X-ray polarimeters based on Bragg reflection. Developments in scintillator and solid-state hard X-ray detectors facilitate construction of both modular, large area Compton scattering polarimeters and compact devices suitable for use with focusing X-ray telescopes.

  13. X-Ray Polarimetry

    OpenAIRE

    Kaaret, Philip

    2014-01-01

    We review the basic principles of X-ray polarimetry and current detector technologies based on the photoelectric effect, Bragg reflection, and Compton scattering. Recent technological advances in high-spatial-resolution gas-filled X-ray detectors have enabled efficient polarimeters exploiting the photoelectric effect that hold great scientific promise for X-ray polarimetry in the 2-10 keV band. Advances in the fabrication of multilayer optics have made feasible the construction of broad-band ...

  14. Acute pulmonary alveolar proteinosis due to exposure to cotton dust

    Directory of Open Access Journals (Sweden)

    Thind Gurcharan

    2009-01-01

    Full Text Available Secondary pulmonary alveolar proteinosis (PAP is rare but may occur in association with malignancy, certain infections, and exposure to inorganic or organic dust and some toxic fumes. This case report describes the second recorded case of PAP due to exposure to cotton dust. A 24-year-old man developed PAP after working as a spinner for eight years without respiratory protection. He was admitted as an emergency patient with very severe dyspnea for four months and cough for several years. Chest X-ray showed bilateral diffuse alveolar consolidation. He died 16 days later, and a diagnosis of acute pulmonary alveolar proteinosis was made at autopsy. The histopathology demonstrated alveoli and respiratory bronchioles filled with characteristic periodic acid Schiff-positive material, which also revealed birefringent bodies of cotton dust under polarized light. Secondary PAP can be fatal and present with acute respiratory failure. The occupational history and characteristic pathology can alert clinicians to the diagnosis.

  15. Elemental changes in hemolymph and urine of Rhodnius prolixus induced by in-vivo exposure to mercury: A study using synchrotron radiation total reflection X-ray fluorescence

    Science.gov (United States)

    Mantuano, Andrea; Pickler, Arissa; Barroso, Regina C.; de Almeida, André P.; Braz, Delson; Cardoso, Simone C.; Gonzalez, Marcelo S.; Figueiredo, Marcela B.; Garcia, Eloi S.; Azambuja, Patricia

    2012-05-01

    In recent years, the effects of pollution on the health of humans and other vertebrates were extensively studied. However, the effects on some invertebrates are comparatively unknown. Recent studies have demonstrated that toxic metals interfere with the reproduction, development and immune defenses of some terrestrial and marine invertebrates. Some environmental conditions including pollution produce chronic and acute effects on different animal's organs and systems. In this work, we investigated changes in the concentrations of Cl, K, Ca, Fe and Zn in Rhodnius prolixus as insect model. The elements were quantified using urine and hemolymph samples collected on different days after feeding the insects with blood containing HgCl2. The synchrotron radiation total reflection X-ray fluorescence measurements were carried at the X-ray fluorescence beamline facility in Brazilian Synchrotron Light Laboratory. The observation reveals that the calcium level was higher in the hemolymph than in urine. On the other hand, the urine collected from insects treated with HgCl2 showed higher level of Cl than hemolymph samples. Ca, Fe and Zn concentrations decrease drastically in urine samples collected after 2 days of HgCl2 treatment. The regulation of triatomines excretion was discussed pointing out the importance of trace elements.

  16. Marked increase in the rate of ocular lens and forelimb regeneration in the newt. Cynops pyrrhogaster, following partial body exposure to low dose X-rays

    Energy Technology Data Exchange (ETDEWEB)

    Okamoto, T.; Kanao, T.; Miyachi, Y.

    2004-07-01

    In recent years, concern over the stimulating effects of low-dose X-rays has been growing. Therefore the effects of low-dose X-irradiation on lens and forelimb regeneration in the newt were examined. Newts were subjected to s harm or whole-body X-ray exposure at a dose of 0.05, 0.2 or 0.4Gy, delivered at a rate of 0.43Gy/min. The eyeballs were fixed in formalin solution, embedded in paraffin and assessed histologically. On day 14 after lens removal, unexposed animals showed the formation of a hollow epithelial vesicle of depigmented cells continuous with the laminae of the iris corresponding to the expected regeneration stage (Reyer's regeneration stage II). In contrast, lenses from newts exposed to a 0.2Gy dose X-ray showed some formation of the primary lens fiber nucleus corresponding to the fiber differentiation stage (Reyer's regeneration stage III-early). Thus, low-dose X-irradiation induced well regeneration compared to the unexposed groups. However, when newts were injected with N-nitro-L-arginine, nitric oxide inhibitor, no radiation-induced effect could be observed. Furthermore, an acceleration from Reyer's stage II to III-early was also found on day 14 following irradiation of only the upper belly, including the spleen. Interestingly, well regeneration could be observed on forelimb stage. On 6 weeks after amputation, unexposed animal was showed the assembly of the condrogenesis of the radius and ulna. In contrast, forelimb from newts exposed to a 0.2Gy spleen portion was showed the onset of digit formation. The effects of low-dose X-irradiation on regeneration may be mediated by changes in immune activity. (Author)

  17. X-ray flat panel detectors and X-ray tubes contributing to development of X-ray diagnostic systems

    International Nuclear Information System (INIS)

    X-ray flat panel detectors (FPDs) and X-ray tubes are key devices allowing X-ray diagnostic systems to support more sophisticated medical care. FPDs provide valuable information for the diagnosis of various diseases through the conversion of X-ray images of the human body into electronic signals, while X-ray tubes are used in a wide range of applications such as computed tomography (CT), angiography, fluoroscopy, mammography, and dental systems. Toshiba Electron Tubes and Devices Co., Ltd. has developed and commercialized FPDs providing high-quality diagnostic X-ray images with low dose exposure through the development of cutting-edge technologies including a fine crystal formation technology for cesium iodide (CsI) scintillators, thin-film transistor (TFT) arrays with photodiodes, and so on. In the field of X-ray tubes that can generate a high output of X-rays, we have developed a liquid metal hydrodynamic bearing (LM bearing) technology for various diagnostic systems including medical CT systems with a long lifetime and high rotation speed, and cardiovascular imaging systems with quiet operation. Furthermore, LM bearing technology reduces the burden on the environment by replacing insulating oil with water coolant for the cooling system and making the X-ray tubes more compact. (author)

  18. Radiation exposure due to cosmic rays and solar X-ray photons at various atmospheric heights in aviation range over India

    Science.gov (United States)

    Palit, Sourav; Chakrabarti, Sandip Kumar; Bhattacharya, Arnab

    2016-07-01

    In this presentation we present our work on the continuous monitoring of radiation exposure in terms of effective dose rates, due to galactic cosmic rays (GCR) and solar X-rays at various altitudes within aviation range over India. As India belongs to equatorial region, there is negligible contribution from solar energetic particles (SEP). The calculation of cosmic ray counts as well as the solar X-ray photons are performed on the basis of the observation of various Dignity series balloon experiments on cosmic ray and solar high energy radiation studies, conducted by ICSP and Monte Carlo simulations performed with GEANT4 detector simulation software. The information on solar activity level from Geostationary Operational Environmental Satellite system (GOES) are employed in the calculations. A program, which is done entirely in MATLAB is employed to update regularly in a website, where we show images of dose rate (μSv) distribution over India at four different heights within the aviation range (updating at an interval of 30 minutes) and the approximate dose rates thats should be experienced by a pilot in an entire flight time between pairs of stations distributed all over India.

  19. Analgesia induced by repeated exposure to low dose X-rays in mice, and involvement of the accessory olfactory system in modulation of the radiation effects

    International Nuclear Information System (INIS)

    The effects of low-dose X-rays on mouse nociceptive behavior were examined using a formalin injected test which rated the amount of time the animals spent licking the injected hind-paw. Male ICR White Swiss mice showed a marked suppression of licking behavior after repeated low-dose X-irradiation (5 cGy/day, 6 consecutive days). The most profound effect was observed on the day 30 after irradiation. The decline of licking behavior, however, was not observed at all following olfactory bulbectomy or vomeronasal tract cut. The analgesic effects could be observed in writhing animals administered acetic-acid intraperitoneally. Moreover, analgesia was totally blocked by the administration of N-nitro-L-arginine, a nitric oxide synthase inhibitor, to accessory olfactory bulbs prior to the exposure. The present results indicate that the olfactory system plays an important role in modulation of radiation-induced analgesia, and a possible involvement of nitric oxide in the formation of recognition memory subjected to repeated X-rays. Relatively higher doses (5 cGy x 9 days, 5 cGy x 12 days), however, did not induce such effects, namely, the decline of nociceptive response was limited to the animals irradiated with the smaller dose. (author)

  20. X-ray - skeleton

    Science.gov (United States)

    A skeletal x-ray is an imaging test used to look at the bones. It is used to detect fractures , tumors, or ... in the health care provider's office by an x-ray technologist. You will lie on a table or ...

  1. Extremity x-ray

    Science.gov (United States)

    An extremity x-ray is an image of the hands, wrist, feet, ankle, leg, thigh, forearm humerus or upper arm, hip, shoulder ... term "extremity" often refers to a human limb. X-rays are a form of radiation that passes through ...

  2. X-ray interferometers

    International Nuclear Information System (INIS)

    An improved type of amplitude-division x-ray interferometer is described. The wavelength at which the interferometer can operate is variable, allowing the instrument to be used to measure x-ray wavelength, and the angle of inclination is variable for sample investigation. (U.K.)

  3. X-ray crystallography

    Science.gov (United States)

    2001-01-01

    X-rays diffracted from a well-ordered protein crystal create sharp patterns of scattered light on film. A computer can use these patterns to generate a model of a protein molecule. To analyze the selected crystal, an X-ray crystallographer shines X-rays through the crystal. Unlike a single dental X-ray, which produces a shadow image of a tooth, these X-rays have to be taken many times from different angles to produce a pattern from the scattered light, a map of the intensity of the X-rays after they diffract through the crystal. The X-rays bounce off the electron clouds that form the outer structure of each atom. A flawed crystal will yield a blurry pattern; a well-ordered protein crystal yields a series of sharp diffraction patterns. From these patterns, researchers build an electron density map. With powerful computers and a lot of calculations, scientists can use the electron density patterns to determine the structure of the protein and make a computer-generated model of the structure. The models let researchers improve their understanding of how the protein functions. They also allow scientists to look for receptor sites and active areas that control a protein's function and role in the progress of diseases. From there, pharmaceutical researchers can design molecules that fit the active site, much like a key and lock, so that the protein is locked without affecting the rest of the body. This is called structure-based drug design.

  4. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... Resources Professions Site Index A-Z X-ray (Radiography) - Bone Bone x-ray uses a very small ... X-ray (Radiography)? What is Bone X-ray (Radiography)? An x-ray (radiograph) is a noninvasive medical ...

  5. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... Professions Site Index A-Z X-ray (Radiography) - Bone Bone x-ray uses a very small dose ... limitations of Bone X-ray (Radiography)? What is Bone X-ray (Radiography)? An x-ray (radiograph) is ...

  6. Lumbosacral spine x-ray

    Science.gov (United States)

    X-ray - lumbosacral spine; X-ray - lower spine ... The test is done in a hospital x-ray department or your health care provider's office by an x-ray technician. You will be asked to lie on the x-ray table ...

  7. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... News Physician Resources Professions Site Index A-Z X-ray (Radiography) - Bone Bone x-ray uses a very ... of Bone X-ray (Radiography)? What is Bone X-ray (Radiography)? An x-ray (radiograph) is a noninvasive ...

  8. Abdomen X-Ray (Radiography)

    Science.gov (United States)

    ... News Physician Resources Professions Site Index A-Z X-ray (Radiography) - Abdomen Abdominal x-ray uses a very ... of an abdominal x-ray? What is abdominal x-ray? An x-ray (radiograph) is a noninvasive medical ...

  9. X-ray lasers

    CERN Document Server

    Elton, Raymond C

    2012-01-01

    The first in its field, this book is both an introduction to x-ray lasers and a how-to guide for specialists. It provides new entrants and others interested in the field with a comprehensive overview and describes useful examples of analysis and experiments as background and guidance for researchers undertaking new laser designs. In one succinct volume, X-Ray Lasers collects the knowledge and experience gained in two decades of x-ray laser development and conveys the exciting challenges and possibilities still to come._Add on for longer version of blurb_M>The reader is first introduced

  10. Clinical and Laboratory Findings in Patients With Acute Respiratory Symptoms That Suggest the Necessity of Chest X-ray for Community-Acquired Pneumonia

    International Nuclear Information System (INIS)

    Pneumonia is a common illness in all parts of the world and is considered as a major cause of death among all age groups. Nevertheless, only about 5% of patients referring to their primary care physicians with acute respiratory symptoms will develop pneumonia. This study was performed to derive practical criteria for performing chest radiographs for the evaluation of community-acquired pneumonia (CAP). A total of 420 patients with acute respiratory symptoms and positive findings on chest radiograph were evaluated from December 2008 to December 2009. The subjects were referred to outpatient clinics or emergency departments of Birjand's medical university hospitals, Iran, and were enrolled as positive cases. A checklist was completed for each patient including their demographic information, clinical signs and symptoms (cough, sputum production, dyspnea, chest pain, fever, tachycardia, and tachypnea), abnormal findings in pulmonary auscultation and laboratory findings (erythrocyte sedimentation rate, C-reactive protein levels, and white blood cell count). An equal number of age-matched individuals with acute respiratory symptoms, but insignificant findings on chest radiography, were included as the control group. Finally, the diagnostic values of different findings were compared. The data showed that vital signs and physical examination findings are useful screening parameters for predicting chest radiograph findings in outpatient settings. Therefore, by implementing a prediction rule, we would be able to determine which patients would benefit from a chest X-Ray (sensitivity, 94% and specificity, 57%). This study's findings suggest that requesting chest radiographs might not be necessary in patients with acute respiratory symptoms unless the vital signs and/or physical examination findings are abnormal. Considering the 94% sensitivity of this rule for predicting CAP, a chest radiograph is required for patients with unreliable follow-ups or moderate to high

  11. Prenatal pesticide exposure and PON1 genotype associated with adolescent body fat distribution evaluated by dual X-ray absorptiometry (DXA).

    Science.gov (United States)

    Tinggaard, J; Wohlfahrt-Veje, C; Husby, S; Christiansen, L; Skakkebaek, N E; Jensen, T K; Grandjean, P; Main, K M; Andersen, H R

    2016-07-01

    Many modern pesticides have endocrine disrupting abilities and early-life exposure may affect growth and disease risk later in life. Previously, we reported associations between prenatal pesticide exposure and higher childhood body fat content measured by anthropometry. The associations were affected by child PON1 Q192R genotype. We aimed to study whether prenatal pesticide exposure was still associated with body fat content and distribution in the children at puberty and the potential impact of both maternal and child PON1 Q192R genotype. In this prospective cohort study of 247 children born by occupationally exposed or unexposed women (greenhouse workers and controls) two follow-up examinations (age 10-15 and 11-16 years) including simple anthropometry, skinfold measurements, pubertal staging and blood sampling were performed. Total and regional fat% was determined by dual X-ray absorptiometry (DXA) at age 10-15. Prenatal pesticide exposure was associated with increased total, android, and gynoid fat percentage (DXA) at age 10-15 years after adjustment for sex, socioeconomic status, and puberty (all β = 0.5 standard deviation score (SDS) p android-gynoid ratio: β = 0.1, both p android fat deposition, independent of puberty. Girls appeared more susceptible than boys. Furthermore, the association depended on maternal and child PON1 Q192R genotype.

  12. X-Ray Diffraction.

    Science.gov (United States)

    Smith, D. K.; Smith, K. L.

    1980-01-01

    Reviews applications in research and analytical characterization of compounds and materials in the field of X-ray diffraction, emphasizing new developments in applications and instrumentation in both single crystal and powder diffraction. Cites 414 references. (CS)

  13. Medical X-Rays

    Science.gov (United States)

    ... The Conference of Radiation Control Program Directors (CRCPD) publishes Suggested State Regulations for the Control of Radiation , ... eSubmitter Guidance for Industry and Food and Drug Administration Staff - Assembler's Guide to Diagnostic X-Ray Equipment ...

  14. Chest X-Ray

    Medline Plus

    Full Text Available ... However, it’s important to consider the likelihood of benefit to your health. While a chest x-ray use a tiny dose of ionizing radiation, the benefit of an accurate diagnosis far outweighs any risk. ...

  15. Chest X-Ray

    Medline Plus

    Full Text Available ... chest x-ray is used to evaluate the lungs, heart and chest wall and may be used ... diagnose and monitor treatment for a variety of lung conditions such as pneumonia, emphysema and cancer. A ...

  16. The Medical Exposure to Ionizing Radiation and Protection of the Patient in Medical Imaging Procedures for Diagnostic and Therapeutic Purposes (Excluding Radiotherapy) using X-Rays in Israel - Risk - Cost and Benefit

    International Nuclear Information System (INIS)

    Diagnostic and therapeutic radiology is playing a major role in modern medicine. The utilization of devices emitting ionizing radiation for medical diagnostic and therapeutic purposes is classified into three categories: a. Radiotherapy procedures for the treatment of malignant and benign tumors. b. Nuclear medicine procedures using radiopharmaceuticals that are introduced into the patient's body for diagnostic and therapeutic purposes. c. Diagnostic and therapeutic x-ray imaging procedures. This group includes conventional radiography, conventional fluoroscopy, cardiac catheterization, angiography, CT, mammography, dental, and fluoroscopy operation procedures. A survey was carried out on a sample of three major Israeli hospitals in order to: 1. Determine the status of radiation protection of patients in Israel with regard to the use of x-rays in medical imaging and interventional radiology. 2. Assess the extent of exposure of the population to medical x-rays, and assess the collective risk in Israel in this relation (based on Icr-60). 3. Carry out a cost-benefit optimization procedure related to the means that should be used to reduce the exposure of Israeli patients under x-ray procedures. 4. Establish a of practical recommendations to reduce the x-ray radiation exposure of patients and to increase the image quality. 5. Establish a number of basic rules to be utilized by health policy makers in Israel

  17. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... drawer under the table holds the x-ray film or image recording plate . Sometimes the x-ray ... extended over the patient while an x-ray film holder or image recording plate is placed beneath ...

  18. On the ultimate x-ray detector for angiography

    NARCIS (Netherlands)

    Slump, C.H.; Kauffman, J.A.; Flynn, M.J.

    2005-01-01

    The purpose of our research is to describe the ultimate X-ray detector for angiography. Angiography is a well established X-ray imaging technique for the examination of blood vessels. Contrast agent is injected followed by X-ray exposures and possible obstructions in the blood vessels can be visuali

  19. Exposure and analysis of microparticles embedded in silica aerogel keystones using NF3-mediated electron beam-induced etching and energy-dispersive X-ray spectroscopy

    Science.gov (United States)

    Martin, Aiden A.; Lin, Ting; Toth, Milos; Westphal, Andrew J.; Vicenzi, Edward P.; Beeman, Jeffrey; Silver, Eric H.

    2016-07-01

    In 2006, NASA's Stardust spacecraft delivered to Earth dust particles collected from the coma of comet 81P/Wild 2, with the goal of furthering the understanding of solar system formation. Stardust cometary samples were collected in a low-density, nanoporous silica aerogel making their study technically challenging. This article demonstrates the identification, exposure, and elemental composition analysis of particles analogous to those collected by NASA's Stardust mission using in-situ SEM techniques. Backscattered electron imaging is shown by experimental observation and Monte Carlo simulation to be suitable for locating particles of a range of sizes relevant to Stardust (down to submicron diameters) embedded within silica aerogel. Selective removal of the silica aerogel encapsulating an embedded particle is performed by cryogenic NF3-mediated electron beam-induced etching. The porous, low-density nature of the aerogel results in an enhanced etch rate compared with solid material, making it an effective, nonmechanical method for the exposure of particles. After exposure, elemental composition of the particle was analyzed by energy-dispersive X-ray spectroscopy using a high spectral resolution microcalorimeter. Signals from fluorine contamination are shown to correspond to nonremoved silica aerogel and only in residual concentrations.

  20. Combined Exposure to Simulated Microgravity and Acute or Chronic Radiation Reduces Neuronal Network Integrity and Survival

    OpenAIRE

    Giuseppe Pani; Mieke Verslegers; Roel Quintens; Nada Samari; Louis de Saint-Georges; Patrick Van Oostveldt; Sarah Baatout; Mohammed Abderrafi Benotmane

    2016-01-01

    During orbital or interplanetary space flights, astronauts are exposed to cosmic radiations and microgravity. However, most earth-based studies on the potential health risks of space conditions have investigated the effects of these two conditions separately. This study aimed at assessing the combined effect of radiation exposure and microgravity on neuronal morphology and survival in vitro. In particular, we investigated the effects of simulated microgravity after acute (X-rays) or during ch...

  1. Dental x-ray diagnostic installation

    International Nuclear Information System (INIS)

    An exemplary embodiment comprises an exposure unit including an X-ray tube and a cassette holder rotatable about vertical axes and between which the head of the patient is disposed. A radiation detector is disposed at the cassette holder for supplying an electrical signal corresponding to the dose rate when it is struck by X-rays and being interconnected with an X-ray tube voltage controller and a dose rate regulator in such manner that the X-ray tube voltage is influenced by the output of the radiation detector to control the dose rate to a value producing an optimum film blackening. A function generator determining the speed of the exposure unit is provided in which a speed curve is stored given which the radiation dose influencing the film is approximately constant

  2. X-ray Pulsars

    CERN Document Server

    Walter, Roland

    2016-01-01

    X-ray pulsars shine thanks to the conversion of the gravitational energy of accreted material to X-ray radiation. The accretion rate is modulated by geometrical and hydrodynamical effects in the stellar wind of the pulsar companions and/or by instabilities in accretion discs. Wind driven flows are highly unstable close to neutron stars and responsible for X-ray variability by factors $10^3$ on time scale of hours. Disk driven flows feature slower state transitions and quasi periodic oscillations related to orbital motion and precession or resonance. On shorter time scales, and closer to the surface of the neutron star, X-ray variability is dominated by the interactions of the accreting flow with the spinning magnetosphere. When the pulsar magnetic field is large, the flow is confined in a relatively narrow accretion column, whose geometrical properties drive the observed X-ray emission. In low magnetized systems, an increasing accretion rate allows the ignition of powerful explosive thermonuclear burning at t...

  3. Fabrication of large area X-ray diffraction grating for X-ray phase imaging

    International Nuclear Information System (INIS)

    X-ray lithography, which uses highly directional synchrotron radiation, is one of the technologies that can be used for fabricating micrometer-sized structures. In X-ray lithography, the accuracy of the fabricated structure depends largely on the accuracy of the X-ray mask. Since X-ray radiation is highly directional, a micro-fabrication technology that produces un-tapered and high aspect ratio highly absorbent structures on a low absorbent membrane is required. Conventionally, a resin material is used as the support membrane for large area X-ray masks. However, resin membranes have the disadvantage that they can sag after several cycles of X-ray exposure due to the heat generated by the X-rays. Therefore, we proposed and used thin carbon wafers for the membrane material because carbon has an extremely small thermal expansion coefficient. We fabricated new carbon membrane X-ray masks, and these results of X-ray lithography demonstrate the superior performance.

  4. X-ray astronomy

    International Nuclear Information System (INIS)

    This book contains the lectures, and the most important seminars held at the NATO meeting on X-Ray astronomy in Erice, July 1979. The meeting was an opportune forum to discuss the results of the first 8-months of operation of the X-ray satellite, HEAO-2 (Einstein Observatory) which was launched at the end of 1978. Besides surveying these results, the meeting covered extragalactic astronomy, including the relevant observations obtained in other portions of the electromagnetic spectrum (ultra-violet, optical, infrared and radio). The discussion on galactic X-ray sources essentially covered classical binaries, globular clusters and bursters and its significance to extragalactic sources and to high energy astrophysics was borne in mind. (orig.)

  5. Cell survival studies using ultrasoft x rays

    International Nuclear Information System (INIS)

    Cell survival was studied for V79 hamster, 10T1/2 mouse, and human skin fibroblast cell lines, using carbon K (0.28 keV), copper K (8.0 keV), and 250 kVp x rays. Because of the rapid attenuation of the carbon x rays, cellular dimensions at the time of exposure were measured using optical and electron microscopy, and frequency distributions of mean dose absorbed by the cell nucleus were obtained. The results indicate that the differences in cell killing between ultra-soft and hard x rays may depend on the nuclear thickness of the cells. Studies of the effects of hypoxia on V79 and 10T1/2 cells using carbon K, aluminum K (1.5 keV), and copper K x rays show decreasing OER values with decreasing x-ray energy and no difference between the two cell lines. Age response studies with V79 cells show similar cell-cycle variation of survival for carbon K and aluminum K x rays as for hard x rays

  6. CRL X-RAY TUBE

    OpenAIRE

    Kolchevsky, N. N.; Petrov, P. V.

    2015-01-01

    A novel types of X-ray tubes with refractive lenses are proposed. CRL-R X-ray tube consists of Compound Refractive Lens- CRL and Reflection X-ray tube. CRL acts as X-ray window. CRL-T X-ray consists of CRL and Transmission X-ray tube. CRL acts as target for electron beam. CRL refractive lens acts as filter, collimator, waveguide and focusing lens. Properties and construction of the CRL X-ray tube are discussed.

  7. Diagnostic x-ray examinations in Poland in 2004 in view of the population exposure: The assessment of structure and trends

    International Nuclear Information System (INIS)

    The paper presents the results of the Polish national survey of medical x-ray examinations performed in 2004. A questionnaire was used to collect the data on the number and types of x-ray examinations. The data covered most of x-ray laboratories in Poland, being under the dosimetric surveillance performed by the Radiation Protection Department at the Nofer Institute of Occupational Medicine in Lodz. The number of x-ray procedures in Poland in the year 2004 accounted for 32.4 million examinations, i.e. 830 procedures per 1000 inhabitants; the latter figure includes 65 specialist procedures and 61 dental examinations per 1000 of inhabitants, each. They were performed in over 3000 x-ray laboratories, including operational theatres and dental units. The majority of patients were at the age of 40-60 years and women made over 50% of all those examined. Owing to the modification of the heath care organisation, the profile of examinations performed in x-ray laboratories has changed. Nevertheless, conventional x-ray examinations are still in a majority, among which radiograph's of chest, spine and limbs are most frequently performed. It should be emphasised that the number of the hip joint radiograph's in infants and small children have decreased and practically photo fluorographic examinations have been eliminated from the diagnostic practice. The number of specialist procedures has evidently increased, and thus the frequency of these procedures in Poland and other European countries is comparable. (author)

  8. Chest X-Ray

    Medline Plus

    Full Text Available ... this Site RadiologyInfo.org is produced by: Image/Video Gallery Your radiologist explains chest x-ray. Transcript ... time! Spotlight Recently posted: Pediatric MRI Intravascular Ultrasound Video: Chest CT Video:Thyroid Ultrasound Video: Head CT ...

  9. Chest X-Ray

    Medline Plus

    Full Text Available ... Pediatric Ultrasound Video: Angioplasty & vascular stenting Video: Arthrography Radiology and You About this Site RadiologyInfo.org is ... radiologist explains chest x-ray. Transcript Welcome to Radiology Info dot org! Hello, I’m Dr. Geoffrey ...

  10. Chest X-Ray

    Medline Plus

    Full Text Available ... this Site RadiologyInfo.org is produced by: Image/Video Gallery Your radiologist explains chest x-ray. Transcript ... Recently posted: Focused Ultrasound for Uterine Fibroids Dementia Video: General Ultrasound Video: Pediatric Nuclear Medicine Radiology and ...

  11. Medical x-ray

    International Nuclear Information System (INIS)

    This book describes the fundamental subject about medical radiography. It is a multidisciplinary field that requires cross professional input from scientists, engineers and medical doctors. However, it is presented in simple language to suit different levels of readers from x-ray operators and radiographers to physists, general practitioners and radiology specialists.The book is written in accordance to the requirements of the standard syllabus approved by the Ministry of Health Malaysia for the training of medical x-ray operator and general practitioners. In general, the content is not only designed to provide relevant and essential subject for related professionals in medical radiological services such as x-ray operator, radiographer and radiologists, but also to address those in associated radiological services including nurses, medical technologists and physicists.The book is organized and arranged sequentially into 3 parts for easy reference: Radiation safety; X-ray equipment and associated facilities; Radiography practices. With proper grasping of all these parts, the radiological services could be provided with confident and the highest professional standard. Thus, medical imaging with highest quality that can provide useful diagnostic information at minimum doses and at cost effective could be assured

  12. Room-temperature X-ray diffraction studies of cisplatin and carboplatin binding to His15 of HEWL after prolonged chemical exposure

    International Nuclear Information System (INIS)

    Binding of cisplatin to His15 in hen egg-white lysozyme in aqueous media is observed after prolonged chemical exposure for 15 months, in contrast to the lack of binding that was observed after 4 d in a previous study. Binding of carboplatin is seen in greater detail in the case of room-temperature data collection compared with cryo data collection. The anticancer complexes cisplatin and carboplatin are known to bind to both the Nδ and the N∊ atoms of His15 of hen egg-white lysozyme (HEWL) in the presence of dimethyl sulfoxide (DMSO). However, neither binds in aqueous media after 4 d of crystallization and crystal growth, suggesting that DMSO facilitates cisplatin/carboplatin binding to the N atoms of His15 by an unknown mechanism. Crystals of HEWL cocrystallized with cisplatin in both aqueous and DMSO media, of HEWL cocrystallized with carboplatin in DMSO medium and of HEWL cocrystallized with cisplatin and N-acetylglucosamine (NAG) in DMSO medium were stored for between seven and 15 months. X-ray diffraction studies of these crystals were carried out on a Bruker APEX II home-source diffractometer at room temperature. Room-temperature X-ray diffraction data collection removed the need for cryoprotectants to be used, ruling out any effect that the cryoprotectants might have had on binding to the protein. Both cisplatin and carboplatin still bind to both the Nδ and N∊ atoms of His15 in DMSO media as expected, but more detail for the cyclobutanedicarboxylate (CBDC) moiety of carboplatin was observed at the N∊ binding site. However, two molecules of cisplatin were now observed to be bound to His15 in aqueous conditions. The platinum peak positions were identified using anomalous difference electron-density maps as a cross-check with Fo − Fc OMIT electron-density maps. The occupancies of each binding site were calculated using SHELXTL. These results show that over time cisplatin binds to both N atoms of His15 of HEWL in aqueous media, whereas this binding is

  13. Methylation changes in muscle and liver tissues of male and female mice exposed to acute and chronic low-dose X-ray-irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Kovalchuk, Olga; Burke, Paula; Besplug, Jill; Slovack, Mark; Filkowski, Jody; Pogribny, Igor

    2004-04-14

    The biological and genetic effects of chronic low-dose radiation (LDR) exposure and its relationship to carcinogenesis have received a lot of attention in the recent years. For example, radiation-induced genome instability, which is thought to be a precursor of tumorogenesis, was shown to have a transgenerational nature. This indicates a possible involvement of epigenetic mechanisms in LDR-induced genome instability. Genomic DNA methylation is one of the most important epigenetic mechanisms. Existing data on radiation effects on DNA methylation patterns is limited, and no one has specifically studied the effects of the LDR. We report the first study of the effects of whole-body LDR exposure on global genome methylation in muscle and liver tissues of male and female mice. In parallel, we evaluated changes in promoter methylation and expression of the tumor suppressor gene p16{sup INKa} and DNA repair gene O{sup 6}-methylguanine-DNA methyltransferase (MGMT). We observed different patterns of radiation-induced global genome DNA methylation in the liver and muscle of exposed males and females. We also found sex and tissue-specific differences in p16{sup INKa} promoter methylation upon LDR exposure. In male liver tissue, p16{sup INKa} promoter methylation was more pronounced than in female tissue. In contrast, no significant radiation-induced changes in p16{sup INKa} promoter methylation were noted in the muscle tissue of exposed males and females. Radiation also did not significantly affect methylation status of MGMT promoter. We also observed substantial sex differences in acute and chronic radiation-induced expression of p16{sup INKa} and MGMT genes. Another important outcome of our study was the fact that chronic low-dose radiation exposure proved to be a more potent inducer of epigenetic effects than the acute exposure. This supports previous findings that chronic exposure leads to greater genome destabilization than acute exposure.

  14. Pyroelectric x-ray detectors and x-ray pyrometers

    International Nuclear Information System (INIS)

    This paper discusses pyroelectric detectors which are very promising x-ray detectors for intense pulsed x-ray/γ-ray measurements and can be used as x-ray pyrometers. They are fast, passive, and inherently flat in spectral response for low energy x-rays. The authors report tests of LiTaO3, Sr.5Ba.5Nb2O6 and LiNbO3 detectors at Nova laser with 1 ns low energy x-rays and at Zapp Z-pinch machine with 100 ns x-rays. The temporal and spectral responses are discussed

  15. Pyroelectric x-ray detectors and x-ray pyrometers

    International Nuclear Information System (INIS)

    Pyroelectric detectors are very promising x-ray detectors for intense pulsed x-ray/γ-ray measurements and can be used as x-ray pyrometers. They are fast, passive, and inherently flat in spectral response for low-energy x rays. We report our tests of LiTaO3 detectors at Nova laser with 1-ns low-energy x rays and at Zapp Z-pinch machine with 100-ns x rays. The temporal and spectral responses are discussed

  16. 移动X线机遥控曝光改造2例%Two Cases of Mobile X-Ray Exposured Unit by Remote Control

    Institute of Scientific and Technical Information of China (English)

    石维结; 童其荣; 向云

    2011-01-01

    The article introduce two modifications, one for a mobile X-ray machine; the other is a C-armX-ray machine, which exposed by remote contml.%本文介绍了1例床边X线机和1例手术室X线机C型臂通过改装,利用遥控器控制曝光的过程.

  17. Duodenal crypt health following exposure to Cr(VI): Micronucleus scoring, γ-H2AX immunostaining, and synchrotron X-ray fluorescence microscopy.

    Science.gov (United States)

    Thompson, Chad M; Wolf, Jeffrey C; Elbekai, Reem H; Paranjpe, Madhav G; Seiter, Jennifer M; Chappell, Mark A; Tappero, Ryan V; Suh, Mina; Proctor, Deborah M; Bichteler, Anne; Haws, Laurie C; Harris, Mark A

    2015-08-01

    Lifetime exposure to high concentrations of hexavalent chromium [Cr(VI)] in drinking water results in intestinal damage and an increase in duodenal tumors in B6C3F1 mice. To assess whether these tumors could be the result of a direct mutagenic or genotoxic mode of action, we conducted a GLP-compliant 7-day drinking water study to assess crypt health along the entire length of the duodenum. Mice were exposed to water (vehicle control), 1.4, 21, or 180 ppm Cr(VI) via drinking water for 7 consecutive days. Crypt enterocytes in Swiss roll sections were scored as normal, mitotic, apoptotic, karyorrhectic, or as having micronuclei. A single oral gavage of 50mg/kg cyclophosphamide served as a positive control for micronucleus induction. Exposure to 21 and 180 ppm Cr(VI) significantly increased the number of crypt enterocytes. Micronuclei and γ-H2AX immunostaining were not elevated in the crypts of Cr(VI)-treated mice. In contrast, treatment with cyclophosphamide significantly increased numbers of crypt micronuclei and qualitatively increased γ-H2AX immunostaining. Synchrotron-based X-ray fluorescence (XRF) microscopy revealed the presence of strong Cr fluorescence in duodenal villi, but negligible Cr fluorescence in the crypt compartment. Together, these data indicate that Cr(VI) does not adversely effect the crypt compartment where intestinal stem cells reside, and provide additional evidence that the mode of action for Cr(VI)-induced intestinal cancer in B6C3F1 mice involves chronic villous wounding resulting in compensatory crypt enterocyte hyperplasia. PMID:26232259

  18. X-Rays from Saturn and its Rings

    Science.gov (United States)

    Bhardwaj, Anil; Elsner, Ron F.; Waite, J. Hunter; Gladstone, G. Randall; Cravens, Tom E.; Ford, Peter G.

    2005-01-01

    In January 2004 Saturn was observed by Chandra ACIS-S in two exposures, 00:06 to 11:00 UT on 20 January and 14:32 UT on 26 January to 01:13 UT on 27 January. Each continuous observation lasted for about one full Saturn rotation. These observations detected an X-ray flare from the Saturn's disk and indicate that the entire Saturnian X-ray emission is highly variable -- a factor of $\\sim$4 variability in brightness in a week time. The Saturn X-ray flare has a time and magnitude matching feature with the solar X-ray flare, which suggests that the disk X-ray emission of Saturn is governed by processes happening on the Sun. These observations also unambiguously detected X-rays from Saturn's rings. The X-ray emissions from rings are present mainly in the 0.45-0.6 keV band centered on the atomic OK$\\alpha$ fluorescence line at 525 eV: indicating the production of X-rays due to oxygen atoms in the water icy rings. The characteristics of X-rays from Saturn's polar region appear to be statistically consistent with those from its disk X-rays, suggesting that X-ray emission from the polar cap region might be an extension of the Saturn disk X-ray emission.

  19. New intraoral x-ray fluorographic imaging for dentistry

    International Nuclear Information System (INIS)

    A new dental x-ray fluorographic unit has been developed. This unit is composed of small intraoral x-ray tube, a compact x-ray image intensifier, and a high-resolution TV system. The purposes for developing this equipment were to (1) directly observe the tooth during endodontic procedures and (2) reduce x-ray exposure to the patient and the dentist. The radiation exposure can be reduced to about 1/600 the exposure used with conventional dental film. In clinical trials, a satisfactory fluorographic dental image for endodontic treatment was obtained with this new device

  20. Variations in elemental compositions of rat hippocampal formation between acute and latent phases of pilocarpine-induced epilepsy: an X-ray fluorescence microscopy study.

    Science.gov (United States)

    Chwiej, J; Dulinska, J; Janeczko, K; Appel, K; Setkowicz, Z

    2012-06-01

    There is growing experimental evidence that tracing the elements involved in brain hyperexcitability, excitotoxicity, and/or subsequent neurodegeneration could be a valuable source of data on the molecular mechanisms triggering or promoting further development of epilepsy. The most frequently used experimental model of the temporal lobe epilepsy observed in clinical practice is the one based on pilocarpine-induced seizures. In the frame of this study, the elemental anomalies occurring for the rat hippocampal tissue in acute and silent periods after injection of pilocarpine in rats were compared. X-ray fluorescence microscopy was applied for the topographic and quantitative elemental analysis. The differences in the levels of elements such as P, S, K, Ca, Fe, Cu, and Zn between the rats 3 days (SE72) and 6 h (SE6) after pilocarpine injection as well as naive controls were examined. Comparison of SE72 and control groups showed, for specific areas of the hippocampal formation, lower levels of P, K, Cu, and Zn, and an increase in Ca accumulation. These results as well as further analysis of the differences between the SE72 and SE6 groups confirmed that seizure-induced excitotoxicity as well as mossy fiber sprouting are the mechanisms involved in the neurodegenerative processes which may finally lead to spontaneous seizures in the chronic period of the pilocarpine model. Moreover, in the light of the results obtained, Cu seems to play a very important role in the pathogenesis of epilepsy in this animal model. For all areas analyzed, the levels of this element recorded in the latent period were not only lower than those for controls but were even lower than the levels found in the acute period. The decreased hippocampal accumulation of Cu in the phase of behavior and EEG stabilization, a possible inhibitory effect of this element on excitatory amino acid receptors, and enhanced seizure susceptibility in Menkes disease (an inherited Cu transport disorder leading to Cu

  1. Modeling and characterization of X-ray yield in a polychromatic, lab-scale, X-ray computed tomography system

    International Nuclear Information System (INIS)

    A modular X-ray computed micro-tomography (µXCT) system is characterized in terms of X-ray yield resulting both from the generated X-ray spectrum and from X-ray detection with an energy-sensitive detector. The X-ray computed tomography system is composed of a commercially available cone-beam microfocus X-ray source and a modular optically-coupled-CCD-scintillator X-ray detector. The X-ray yield is measured and reported in units independent from exposure time, X-ray tube beam target current, and cone-beam-to-detector geometry. The polychromatic X-ray source is modeled as a broad Bremsstrahlung X-ray spectrum in order to understand the effect of the controllable parameters, that is, X-ray tube accelerating voltage and X-ray beam filtering. An approach is adopted which expresses the absolute number of emitted X-rays. The response of the energy-sensitive detector to the modeled spectrum is modeled as a function of scintillator composition and thickness. The detection efficiency model for the polychromatic X-ray detector considers the response of the light collection system and the electronic imaging array in order to predict absolute count yield under the studied conditions. The modeling approach is applied to the specific hardware implemented in the current µXCT system. The model's predictions for absolute detection rate are in reasonable agreement with measured values under a range of conditions applied to the system for X-ray microtomography imaging, particularly for the LuAG:Ce scintillator material

  2. Modeling and characterization of X-ray yield in a polychromatic, lab-scale, X-ray computed tomography system

    Energy Technology Data Exchange (ETDEWEB)

    Mertens, J.C.E.; Chawla, Nikhilesh, E-mail: nchawla@asu.edu

    2015-05-21

    A modular X-ray computed micro-tomography (µXCT) system is characterized in terms of X-ray yield resulting both from the generated X-ray spectrum and from X-ray detection with an energy-sensitive detector. The X-ray computed tomography system is composed of a commercially available cone-beam microfocus X-ray source and a modular optically-coupled-CCD-scintillator X-ray detector. The X-ray yield is measured and reported in units independent from exposure time, X-ray tube beam target current, and cone-beam-to-detector geometry. The polychromatic X-ray source is modeled as a broad Bremsstrahlung X-ray spectrum in order to understand the effect of the controllable parameters, that is, X-ray tube accelerating voltage and X-ray beam filtering. An approach is adopted which expresses the absolute number of emitted X-rays. The response of the energy-sensitive detector to the modeled spectrum is modeled as a function of scintillator composition and thickness. The detection efficiency model for the polychromatic X-ray detector considers the response of the light collection system and the electronic imaging array in order to predict absolute count yield under the studied conditions. The modeling approach is applied to the specific hardware implemented in the current µXCT system. The model's predictions for absolute detection rate are in reasonable agreement with measured values under a range of conditions applied to the system for X-ray microtomography imaging, particularly for the LuAG:Ce scintillator material.

  3. X-ray diffraction

    International Nuclear Information System (INIS)

    We have been interested in structural elucidation by x-ray diffraction of compounds of biological interest. Understanding exactly how atoms are arranged in three-dimensional arrays as molecules can help explain the relationship between structure and functions. The species investigated may vary in size and shape; our recent studies included such diverse substances as antischistosomal drugs, a complex of cadmium with nucleic acid base, nitrate salts of adenine, and proteins

  4. Demonstration of x-ray holography with an x-ray laser

    International Nuclear Information System (INIS)

    X-ray holography offers the potential for obtaining high resolution three-dimensional images of in vitro biological microstructures. Significant progress toward this goal has been achieved with holography systems using synchrotron x-ray sources and recently spatial resolutions as small as 40 nm have been demonstrated. These experiments required x-ray exposures of an hour or longer, which makes high spatial resolution difficult to achieve in live biological specimens because of blurring of the image. This blurring is caused by specimen motion and prohibits the imaging of dynamical processes within the specimen. A possible solution to this problem is to exploit the extremely high brightness and long coherence lengths produced by x-ray lasers and create the hologram with exposure times of less than 1 nsec. This report presents the results from an experiment in which an x-ray laser was used to produce x-ray holograms. The holography geometry used was a Gabor in-line type modified by the inclusion of a high reflectivity multi-layer x-ray mirror used as a narrow bandpass filter

  5. Computed tomography of the chest with model-based iterative reconstruction using a radiation exposure similar to chest X-ray examination: preliminary observations

    Energy Technology Data Exchange (ETDEWEB)

    Neroladaki, Angeliki; Botsikas, Diomidis; Boudabbous, Sana; Becker, Christoph D.; Montet, Xavier [Geneva University Hospital, Department of Radiology, Geneva 4 (Switzerland)

    2013-02-15

    The purpose of this study was to assess the diagnostic image quality of ultra-low-dose chest computed tomography (ULD-CT) obtained with a radiation dose comparable to chest radiography and reconstructed with filtered back projection (FBP), adaptive statistical iterative reconstruction (ASIR) and model-based iterative reconstruction (MBIR) in comparison with standard dose diagnostic CT (SDD-CT) or low-dose diagnostic CT (LDD-CT) reconstructed with FBP alone. Unenhanced chest CT images of 42 patients acquired with ULD-CT were compared with images obtained with SDD-CT or LDD-CT in the same examination. Noise measurements and image quality, based on conspicuity of chest lesions on all CT data sets were assessed on a five-point scale. The radiation dose of ULD-CT was 0.16 {+-} 0.006 mSv compared with 11.2 {+-} 2.7 mSv for SDD-CT (P < 0.0001) and 2.7 {+-} 0.9 mSv for LDD-CT. Image quality of ULD-CT increased significantly when using MBIR compared with FBP or ASIR (P < 0.001). ULD-CT reconstructed with MBIR enabled to detect as many non-calcified pulmonary nodules as seen on SDD-CT or LDD-CT. However, image quality of ULD-CT was clearly inferior for characterisation of ground glass opacities or emphysema. Model-based iterative reconstruction allows detection of pulmonary nodules with ULD-CT with radiation exposure in the range of a posterior to anterior (PA) and lateral chest X-ray. (orig.)

  6. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... wrist, arm, elbow, shoulder, spine, pelvis, hip, thigh, knee, leg (shin), ankle or foot. top of page ... the patient standing upright, as in cases of knee x-rays. A portable x-ray machine is ...

  7. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... images for evaluation. National and international radiology protection organizations continually review and update the technique standards used by radiology professionals. Modern x-ray systems have very controlled x-ray beams and dose ...

  8. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... fracture. guide orthopedic surgery, such as spine repair/fusion, joint replacement and fracture reductions. look for injury, ... and Media Arthritis X-ray, Interventional Radiology and Nuclear Medicine Radiation Safety Images related to X-ray ( ...

  9. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... current x-ray images for diagnosis and disease management. top of page How is the procedure performed? ... top of page What are the benefits vs. risks? Benefits Bone x-rays are the fastest and ...

  10. Dental X-ray apparatus

    International Nuclear Information System (INIS)

    Intra-oral dental X-ray apparatus for panoramic radiography is described in detail. It comprises a tubular target carrier supporting at its distal end a target with an inclined forward face. Image definition is improved by positioning in the path of the X-rays a window of X-ray transmitting ceramic material, e.g. 90% oxide of Be, or Al, 7% Si02. The target carrier forms a probe which can be positioned in the patient's mouth. X-rays are directed forwardly and laterally of the target to an X-ray film positioned externally. The probe is provided with a detachable sleeve having V-form arms of X-ray opaque material which serve to depress the tongue out of the radiation path and also shield the roof of the mouth and other regions of the head from the X-ray pattern. A cylindrical lead shield defines the X-ray beam angle. (author)

  11. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... current x-ray images for diagnosis and disease management. top of page How is the procedure performed? ... position possible that still ensures x-ray image quality. top of page Who interprets the results and ...

  12. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... As a result, bones appear white on the x-ray, soft tissue shows up in shades of gray and air appears black. Until recently, x-ray images were maintained on large film sheets (much ...

  13. Panoramic Dental X-Ray

    Science.gov (United States)

    ... Physician Resources Professions Site Index A-Z Panoramic Dental X-ray Panoramic dental x-ray uses a ... a large photographic negative). Today, most images are digital files that are stored electronically. These stored images ...

  14. Effects of X-Ray Dose On Rhizosphere Studies Using X-Ray Computed Tomography.

    Directory of Open Access Journals (Sweden)

    Susan Zappala

    Full Text Available X-ray Computed Tomography (CT is a non-destructive imaging technique originally designed for diagnostic medicine, which was adopted for rhizosphere and soil science applications in the early 1980s. X-ray CT enables researchers to simultaneously visualise and quantify the heterogeneous soil matrix of mineral grains, organic matter, air-filled pores and water-filled pores. Additionally, X-ray CT allows visualisation of plant roots in situ without the need for traditional invasive methods such as root washing. However, one routinely unreported aspect of X-ray CT is the potential effect of X-ray dose on the soil-borne microorganisms and plants in rhizosphere investigations. Here we aimed to i highlight the need for more consistent reporting of X-ray CT parameters for dose to sample, ii to provide an overview of previously reported impacts of X-rays on soil microorganisms and plant roots and iii present new data investigating the response of plant roots and microbial communities to X-ray exposure. Fewer than 5% of the 126 publications included in the literature review contained sufficient information to calculate dose and only 2.4% of the publications explicitly state an estimate of dose received by each sample. We conducted a study involving rice roots growing in soil, observing no significant difference between the numbers of root tips, root volume and total root length in scanned versus unscanned samples. In parallel, a soil microbe experiment scanning samples over a total of 24 weeks observed no significant difference between the scanned and unscanned microbial biomass values. We conclude from the literature review and our own experiments that X-ray CT does not impact plant growth or soil microbial populations when employing a low level of dose (<30 Gy. However, the call for higher throughput X-ray CT means that doses that biological samples receive are likely to increase and thus should be closely monitored.

  15. 极低频磁场联合或不联合X射线对CHO细胞动粒阳性和阴性微核生成的影响%Effects of ELF magnetic fields exposure with or without X-rays on induction of kinetochore positive and negative micronuclei in CHO cells

    Institute of Scientific and Technical Information of China (English)

    DING Guirong; GUO Guozhen

    2005-01-01

    Extremely low frequency magnetic field (ELFMF) produced by power lines and household electric appliances has been associated with increased incidence of cancers, as was suggested by several epidemiological studies[1]. To test the genotoxic effects of ELFMF, the induction of micronuclei by exposure to ELFMF and/or X-rays was investigated by cytokinesis-block method in cultured Chinese Hamster Ovary (CHO) cells. Approximately 4×105 cells were plated in 10cm dishes, following exposure to an ELF magnetic field (60Hz, 5 mT) for 24h. The cells were irradiated to 1 Gy by X-rays. After the irradiation, cytochalasin B was added to the medium at a final concentration of 3 μg / mL. The cells were then exposed to an ELF magnetic field or placed in a normal incubator for 18 h, which is 1.5 times the length of their cell cycle. The micronuclei derived from acentric fragments or from whole chromosomes were evaluated with the help of immunofluorescent staining using antikinetochore antibodies from the serum of scleroderma (CREST syndrome) patients[2,3].Statistically, no significant difference in the frequency of binucleated cells carrying micronuclei was observed between CHO cells cultured in the normal incubator and those placed in the exposure system for 24h. Following X-ray irradiation, the number of binucleated cells carrying micronuclei increased significantly (p< 0.01). Exposure to an ELF magnetic field for 24 h before the X-ray irradiation or for 18 h after X-ray-irradiation did not affect the number of X-ray-induced micronuclei. Among the micronuclei induced by X-ray-irradiation, only a small number were kinetochore-positive (approximately 4 %). The number of kinetochore-positive micronuclei was significantly increased in the cells treated with X-ray irradiation followed by ELFMF exposure or M+X+M treated cells (exposure to ELF magnetic field before and after X-ray irradiation), but not in the cells treated with ELFMF exposure before X-ray irradiation compared with

  16. X-ray Crystallography Facility

    Science.gov (United States)

    2000-01-01

    Edward Snell, a National Research Council research fellow at NASA's Marshall Space Flight Center (MSFC), prepares a protein crystal for analysis by x-ray crystallography as part of NASA's structural biology program. The small, individual crystals are bombarded with x-rays to produce diffraction patterns, a map of the intensity of the x-rays as they reflect through the crystal.

  17. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... x-rays. top of page What does the equipment look like? The equipment typically used for bone x-rays consists of ... and joint abnormalities, such as arthritis. X-ray equipment is relatively inexpensive and widely available in emergency ...

  18. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... The x-ray tube is connected to a flexible arm that is extended over the patient while an x-ray film holder or image recording plate is placed beneath the patient. top of page How does the procedure work? X-rays are a form of radiation like ...

  19. Tunable X-ray source

    Science.gov (United States)

    Boyce, James R.

    2011-02-08

    A method for the production of X-ray bunches tunable in both time and energy level by generating multiple photon, X-ray, beams through the use of Thomson scattering. The method of the present invention simultaneously produces two X-ray pulses that are tunable in energy and/or time.

  20. X-ray selected BALQSOs

    CERN Document Server

    Page, M J; Ceballos, M; Corral, A; Ebrero, J; Esquej, P; Krumpe, M; Mateos, S; Rosen, S; Schwope, A; Streblyanska, A; Symeonidis, M; Tedds, J A; Watson, M G

    2016-01-01

    We study a sample of six X-ray selected broad absorption line (BAL) quasi-stellar objects (QSOs) from the XMM-Newton Wide Angle Survey. All six objects are classified as BALQSOs using the classic balnicity index, and together they form the largest sample of X-ray selected BALQSOs. We find evidence for absorption in the X-ray spectra of all six objects. An ionized absorption model applied to an X-ray spectral shape that would be typical for non-BAL QSOs (a power law with energy index alpha=0.98) provides acceptable fits to the X-ray spectra of all six objects. The optical to X-ray spectral indices, alpha_OX, of the X-ray selected BALQSOs, have a mean value of 1.69 +- 0.05, which is similar to that found for X-ray selected and optically selected non-BAL QSOs of similar ultraviolet luminosity. In contrast, optically-selected BALQSOs typically have much larger alpha_OX and so are characterised as being X-ray weak. The results imply that X-ray selection yields intrinsically X-ray bright BALQSOs, but their X-ray sp...

  1. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... lies. A drawer under the table holds the x-ray film or image recording plate . Sometimes the x-ray ... that is extended over the patient while an x-ray film holder or image recording plate is placed beneath ...

  2. X-Ray Exam: Ankle

    Science.gov (United States)

    ... Tropical Delight: Melon Smoothie Pregnant? Your Baby's Growth X-Ray Exam: Ankle KidsHealth > For Parents > X-Ray Exam: Ankle Print A A A Text Size ... español Radiografía: tobillo What It Is An ankle X-ray is a safe and painless test that uses ...

  3. X-Ray Exam: Finger

    Science.gov (United States)

    ... Tropical Delight: Melon Smoothie Pregnant? Your Baby's Growth X-Ray Exam: Finger KidsHealth > For Parents > X-Ray Exam: Finger Print A A A Text Size ... español Radiografía: dedo What It Is A finger X-ray is a safe and painless test that uses ...

  4. X-Ray Exam: Wrist

    Science.gov (United States)

    ... Tropical Delight: Melon Smoothie Pregnant? Your Baby's Growth X-Ray Exam: Wrist KidsHealth > For Parents > X-Ray Exam: Wrist Print A A A Text Size ... español Radiografía: muñeca What It Is A wrist X-ray is a safe and painless test that uses ...

  5. X-Ray Exam: Hip

    Science.gov (United States)

    ... Tropical Delight: Melon Smoothie Pregnant? Your Baby's Growth X-Ray Exam: Hip KidsHealth > For Parents > X-Ray Exam: Hip Print A A A Text Size ... español Radiografía: cadera What It Is A hip X-ray is a safe and painless test that uses ...

  6. X-Ray Exam: Forearm

    Science.gov (United States)

    ... Tropical Delight: Melon Smoothie Pregnant? Your Baby's Growth X-Ray Exam: Forearm KidsHealth > For Parents > X-Ray Exam: Forearm Print A A A Text Size ... español Radiografía: brazo What It Is A forearm X-ray is a safe and painless test that uses ...

  7. X-Ray Exam: Pelvis

    Science.gov (United States)

    ... Tropical Delight: Melon Smoothie Pregnant? Your Baby's Growth X-Ray Exam: Pelvis KidsHealth > For Parents > X-Ray Exam: Pelvis Print A A A Text Size ... español Radiografía: pelvis What It Is A pelvis X-ray is a safe and painless test that uses ...

  8. X-Ray Exam: Foot

    Science.gov (United States)

    ... Tropical Delight: Melon Smoothie Pregnant? Your Baby's Growth X-Ray Exam: Foot KidsHealth > For Parents > X-Ray Exam: Foot Print A A A Text Size ... español Radiografía: pie What It Is A foot X-ray is a safe and painless test that uses ...

  9. Nordic working group on x-ray diagnostics - Practical implementation of the directive on medical exposures in the Nordic EU countries

    Energy Technology Data Exchange (ETDEWEB)

    Waltenburg, H.N.; Groen, P. [National Institute of Radiation Hygiene, Herlev (Denmark); Leitz, W. [Swedish Radiation Protection Authority, Stockholm (Sweden); Servomaa, A. [Finnish Centre for Radiation and Nuclear Safety, Helsinki (Finland); Einarsson, G. [Icelandic Radiation Protection Institute, Reykjavik (Iceland); Olerud, H. [Norwegian Radiation Protection Authority, Oslo (Norway)

    2003-06-01

    . We will not cover all aspects of MED, instead we have chosen specific points that we think are the most interesting. The scope is limited to diagnostic applications of x-rays, excluding dental, therapy and nuclear medicine applications. (orig.)

  10. Use in plant breeding of acute, chronic or fractionated doses of X-rays or fast neutrons as illustrated with leaves of Saintpaulia

    NARCIS (Netherlands)

    Broertjes, C.

    1971-01-01

    The parameters used were survival of irradiated leaves of S. ionantha , production of adventitious plantlets at the base of the petiole and mutation frequency.The differences between unfiltered X-rays from a 250/25 deep therapy apparatus and fast neutrons from a degraded fissions spectrum was slight

  11. A trial for the quantitative determination of the acute radiation-induced pancreatic islet cell death irradiated with 200 KVp x-ray and 30 MeV fast neutron beams

    International Nuclear Information System (INIS)

    Quantitative counting of acute islet cell death of the golden hamster pancreas was adopted for the determination of radiation injury as one of the model in the slowly growing tissues (or slowly renewing tissues), such as liver, salivary gland, pancreas, kidney etc. First mode and dose response relationship of x-ray induced rapid cell death (interphase death) in golden hamster pancreatic islet cell death was investigated after 10-350 Gy irradiation with the dose rate of 4.5 Gy/min. With a latent period of 2-3 hours, pycnotic cells began to appear after irradiation. Then they reached maximum at 4-5 hours, and at 6 hours later on, their nuclei lysed completely. From the disappearance rate of the nuclei, the mean life span of pycnotic cells was estimated to be approximately 2 hours or less. Thereafter these remnants of dead cells were scavenged from the islets within 16 hours after irradiation. The mode of cell death was almost identical irregardless of different irradiation doses. Therefore through the counting of both pycnotic nuclei and normal looking nuclei at 4-5 hours after irradiation, it was possible to determine the radiosensitivity of the islet cells. Cell death by x-ray was dose-dependent and stochastic throughout all dose range even in a surviving fraction of 10-4 order. Thus obtained radio-sensitivity of the islet cells was 62.5 Gy of Do and 3.2 of n number. Unfortunately, however, in neutron irradiated pancreas, quantitation of cell death was not possible unlike in x-rays. This is because the maximum neutron dose rate available was 0.5-0.6 Gy. Therefore initial aim for the study on comparative biological effect of x-ray and neutron through the acute pancreatic cell death was failed by the dose rate problem. (author)

  12. X-ray today

    Energy Technology Data Exchange (ETDEWEB)

    Neitzel, U. [Philips Medical Systems, Hamburg (Germany)

    2001-09-01

    The interest attracted by the new imaging modalities tends to overshadow the continuing importance of projection radiography and fluoroscopy. Nevertheless, projection techniques still represent by far the greatest proportion of diagnostic imaging examinations, and play an essential role in the growing number of advanced interventional procedures. This article describes some of the latest developments in X-ray imaging technology, using two products from the Philips range as examples: the Integris Allura cardiovascular system with 3D image reconstruction, and the BV Pulsera: a high-end, multi-functional mobile C-arm system with cardiac capabilities. (orig.)

  13. MRI与X线诊断急性化脓性骨髓炎的效果比较%Comparison of the Results of MRI and X-ray in Diagnosis of Acute Pyo-genic Osteomyelitis

    Institute of Scientific and Technical Information of China (English)

    杨帆

    2015-01-01

    目的 比较MRI与X线诊断急性化脓性骨髓炎的临床价值. 方法 随机选取该院自2013年4月-2015年4月收治的50例急性化脓性骨髓炎患者作为研究对象,均作MRI及X线平片检查,比较两种诊断方式的影像学特征,分析MRI与X线在急性化脓性骨髓炎患者临床诊断中的应用价值. 结果 早期采取X线检查仅可显示患者软组织肿胀表现,未见骨质异常改变. 而采用MRI检查,在发病早期即可显示骨髓异常信号及软组织肿胀特点,且IR序列显示结果更为清晰. 结论在急性化脓性骨髓炎患者的早期诊断中,采用MRI诊断方案,组织分辨率高,有无创性优势,可清晰显示小四肢脓肿及骨质破坏表现,可为治疗方案的确立提供影像学指导,值得推广.%Objective To compare the clinical value of MRI and X-ray in diagnosis of acute pyogenic osteomyelitis. Methods 50 patients with acute pyogenic osteomyelitis admitted into the hospital from April 2013 to April 2015 were selected as the research object. All of the chosen patients received both MRI and X-ray plain film examination. The imaging characteristics of two kinds of diagnostic methods were compared and the application value of MRI and X-ray in the clinical diagnosis of patients with acute pyogenic osteomyelitis was analyzed. Results Early X-ray examination only showed manifestation of soft tissue swelling and there were no abnormal changes of sclerotin, while MRI could show signals of bone marrow disorder and characteristics of soft tissue swelling in early period and the displaying results of IR sequence were clearer. Conclusion In the early diagnosis of patients with acute pyogenic osteomyelitis, to adopt MRI diagnostic scheme is of high resolution of tissues and non-invasive. It can clearly dis-play abscess of small limbs and manifestation of bone destruction and provide imaging guidance for establishment of treatment scheme, which is worthy of promotion.

  14. Hemo rheological Changes Associated with Occupational Exposure to Low Doses Radiation from X-Ray Inspection Machines Influenced by Smoking Habits

    International Nuclear Information System (INIS)

    The effects of low dose x-ray radiation on some rheological parameters of blood were investigated in 30 male x-ray workers and 20 healthy volunteers not occupationally exposed to any type of radiation and match in age. Each group was classified according to smoking habits. The analysis of the flow curve of all subjects was performed by applying power-law model and Bingham plastic model. The results indicated elevates in whole blood viscosity and yield stress in smoker subjects as compared with non-smoker subjects and also showed that the elevation of blood viscosity of smoker radiation workers are related to work duration in the radiation field.We have observed that cigarette smoking increases the hazardous effects of radiation through the increase of blood viscosity, which excess the risk of cardiovascular disease. So it is recommended to consider blood viscosity measurements to be included in routine medical investigation for occupational workers and rheological

  15. Topological X-Rays Revisited

    Science.gov (United States)

    Lynch, Mark

    2012-01-01

    We continue our study of topological X-rays begun in Lynch ["Topological X-rays and MRI's," iJMEST 33(3) (2002), pp. 389-392]. We modify our definition of a topological magnetic resonance imaging and give an affirmative answer to the question posed there: Can we identify a closed set in a box by defining X-rays to probe the interior and without…

  16. X-ray instrumentation for SR beamlines

    CERN Document Server

    Kovalchuk, M V; Zheludeva, S I; Aleshko-Ozhevsky, O P; Arutynyan, E H; Kheiker, D M; Kreines, A Y; Lider, V V; Pashaev, E M; Shilina, N Y; Shishkov, V A

    2000-01-01

    The main possibilities and parameters of experimental X-ray stations are presented: 'Protein crystallography', 'X-ray structure analysis', 'High-precision X-ray optics', 'X-ray crystallography and material science', 'X-ray topography', 'Photoelectron X-ray standing wave' that are being installed at Kurchatov SR source by A.V. Shubnikov Institute of Crystallography.

  17. X-ray lithography sources

    International Nuclear Information System (INIS)

    Synchrotron from dipole magnets in electron storage rings has emerged as a useful source of x-rays for lithography. To meet the need for these sources numerous groups around the world have embarked on projects to design and construct storage rings for x-ray lithography. Both conventional electromagnets as well as superconducting (SC) dipoles have been incorporated into the various designs. An overview of the worldwide effort to produce commercial x-ray sources will be presented. To better illustrate the elements involved in these sources a closer examination of the Superconducting X-ray Lithography Source Project (SXLS) at BNL will be presented. 11 refs., 1 fig., 5 tabs

  18. Soft X-ray optics

    CERN Document Server

    Spiller, Eberhard A

    1993-01-01

    This text describes optics mainly in the 10 to 500 angstrom wavelength region. These wavelengths are 50 to 100 times shorter than those for visible light and 50 to 100 times longer than the wavelengths of medical x rays or x-ray diffraction from natural crystals. There have been substantial advances during the last 20 years, which one can see as an extension of optical technology to shorter wavelengths or as an extension of x-ray diffraction to longer wavelengths. Artificial diffracting structures like zone plates and multilayer mirrors are replacing the natural crystals of x-ray diffraction.

  19. X-ray Absorption Spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Yano, Junko; Yachandra, Vittal K.

    2009-07-09

    This review gives a brief description of the theory and application of X-ray absorption spectroscopy, both X-ray absorption near edge structure (XANES) and extended X-ray absorption fine structure (EXAFS), especially, pertaining to photosynthesis. The advantages and limitations of the methods are discussed. Recent advances in extended EXAFS and polarized EXAFS using oriented membranes and single crystals are explained. Developments in theory in understanding the XANES spectra are described. The application of X-ray absorption spectroscopy to the study of the Mn4Ca cluster in Photosystem II is presented.

  20. X-ray Fluorescence Sectioning

    CERN Document Server

    Cong, Wenxiang

    2012-01-01

    In this paper, we propose an x-ray fluorescence imaging system for elemental analysis. The key idea is what we call "x-ray fluorescence sectioning". Specifically, a slit collimator in front of an x-ray tube is used to shape x-rays into a fan-beam to illuminate a planar section of an object. Then, relevant elements such as gold nanoparticles on the fan-beam plane are excited to generate x-ray fluorescence signals. One or more 2D spectral detectors are placed to face the fan-beam plane and directly measure x-ray fluorescence data. Detector elements are so collimated that each element only sees a unique area element on the fan-beam plane and records the x-ray fluorescence signal accordingly. The measured 2D x-ray fluorescence data can be refined in reference to the attenuation characteristics of the object and the divergence of the beam for accurate elemental mapping. This x-ray fluorescence sectioning system promises fast fluorescence tomographic imaging without a complex inverse procedure. The design can be ad...

  1. Radioisotope x-ray analysis

    International Nuclear Information System (INIS)

    Radioisotope x-ray fluorescence and x-ray preferential absorption (XRA) techniques are used extensively for the analysis of materials, covering such diverse applications as analysis of alloys, coal, environmental samples, paper, waste materials, and metalliferous mineral ores and products. Many of these analyses are undertaken in the harsh environment of industrial plants and in the field. Some are continuous on-line analyses of material being processed in industry, where instantaneous analysis information is required for the control of rapidly changing processes. Radioisotope x-ray analysis systems are often tailored to a specific but limited range of applications. They are simpler and often considerably less expensive than analysis systems based on x-ray tubes. These systems are preferred to x-ray tube techniques when simplicity, ruggedness, reliability, and cost of equipment are important; when minimum size, weight, and power consumption are necessary; when a very constant and predictable x-ray output is required; when the use of high-energy x-rays is advantageous; and when short x-ray path lengths are required to minimize the absorption of low-energy x-rays in air. This chapter reviews radioisotope XRF, preferential absorption, and scattering techniques. Some of the basic analysis equations are given. The characteristics of radioisotope sources and x-ray detectors are described, and then the x-ray analytical techniques are presented. The choice of radioisotope technique for a specific application is discussed. This is followed by a summary of applications of these techniques, with a more detailed account given of some of the applications, particularly those of considerable industrial importance. 79 refs., 28 figs., 7 tabs

  2. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... clothing that might interfere with the x-ray images. Women should always inform their physician and x-ray ... small burst of radiation that passes through the body, recording an image on photographic film or a special detector. Different ...

  3. X-ray diagnostic equipment

    International Nuclear Information System (INIS)

    An X-ray tube is connected to several different image processing devices in X-ray diagnostic equipment. Only a single organ selector is allocated to it, for which the picture parameters for each image processing device are selected. The choice of the correct combination of picture parameters is made by means of a selector switch. (DG)

  4. X-ray tube arrangement

    International Nuclear Information System (INIS)

    An x-ray tube is described incorporating an elongated target/ anode over which the electron beam is deflected and from which x-rays are emitted. Improved methods of monitoring and controlling the amplitude of the beam deflection are presented. (U.K.)

  5. Luminescence properties after X-ray irradiation for dosimetry

    Science.gov (United States)

    Hong, Duk-Geun; Kim, Myung-Jin

    2016-05-01

    To investigate the luminescence characteristics after exposure to X-ray radiation, we developed an independent, small X-ray irradiation system comprising a Varian VF-50J mini X-ray generator, a Pb collimator, a delay shutter, and an Al absorber. With this system, the apparent dose rate increased linearly to 0.8 Gy/s against the emission current for a 50 kV anode potential when the shutter was delayed for an initial 4 s and the Al absorber was 300 µm thick. In addition, an approximately 20 mm diameter sample area was irradiated homogeneously with X rays. Based on three-dimensional (3D) thermoluminescence (TL) spectra, the small X-ray irradiator was considered comparable to the conventional 90Sr/90Y beta source even though the TL intensity from beta irradiation was higher than that from X-ray irradiation. The single aliquot regenerative (SAR) growth curve for the small X-ray irradiator was identical to that for the beta source. Therefore, we concluded that the characteristics of the small X-ray irradiator and the conventional 90Sr/90Y beta source were similar and that X ray irradiation had the potential for being suitable for use in luminescence dosimetry.

  6. Severe Acute Respiratory Syndrome-Coronavirus Papain-Like Novel Protease Inhibitors: Design, Synthesis, Protein-Ligand X-ray Structure and Biological Evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Ghosh, Arun K.; Takayama, Jun; Rao, Kalapala Venkateswar; Ratia, Kiira; Chaudhuri, Rima; Mulhearn, Debbie C.; Lee, Hyun; Nichols, Daniel B.; Baliji, Surendranath; Baker, Susan C.; Johnson, Michael E.; Mesecar, Andrew D. (Purdue); (UC); (UIC)

    2012-02-21

    The design, synthesis, X-ray crystal structure, molecular modeling, and biological evaluation of a series of new generation SARS-CoV PLpro inhibitors are described. A new lead compound 3 (6577871) was identified via high-throughput screening of a diverse chemical library. Subsequently, we carried out lead optimization and structure-activity studies to provide a series of improved inhibitors that show potent PLpro inhibition and antiviral activity against SARS-CoV infected Vero E6 cells. Interestingly, the (S)-Me inhibitor 15h (enzyme IC{sub 50} = 0.56 {mu}M; antiviral EC{sub 50} = 9.1 {mu}M) and the corresponding (R)-Me 15g (IC{sub 50} = 0.32 {mu}M; antiviral EC{sub 50} = 9.1 {mu}M) are the most potent compounds in this series, with nearly equivalent enzymatic inhibition and antiviral activity. A protein-ligand X-ray structure of 15g-bound SARS-CoV PLpro and a corresponding model of 15h docked to PLpro provide intriguing molecular insight into the ligand-binding site interactions.

  7. Problems in differential X-ray diagnosis of restrictive pneumothorax in young children

    International Nuclear Information System (INIS)

    To define X-ray signs of restrictive pneumothorax, the authors analyzed X-ray films of 225 newborns and babies of the first 3 months of life who were examined for respiratory disorders and acute respiratory diseases. Restrictive pneumothorax was detected in 19 . The processing X-ray films on the UAP-2 device enhanced the accuracy of restrictive pneumothorax diagnosis in infants and made it possible to do away an additional X-ray study, which reduced radiation loads

  8. Semiconductor X-ray detectors

    CERN Document Server

    Lowe, Barrie Glyn

    2014-01-01

    Identifying and measuring the elemental x-rays released when materials are examined with particles (electrons, protons, alpha particles, etc.) or photons (x-rays and gamma rays) is still considered to be the primary analytical technique for routine and non-destructive materials analysis. The Lithium Drifted Silicon (Si(Li)) X-Ray Detector, with its good resolution and peak to background, pioneered this type of analysis on electron microscopes, x-ray fluorescence instruments, and radioactive source- and accelerator-based excitation systems. Although rapid progress in Silicon Drift Detectors (SDDs), Charge Coupled Devices (CCDs), and Compound Semiconductor Detectors, including renewed interest in alternative materials such as CdZnTe and diamond, has made the Si(Li) X-Ray Detector nearly obsolete, the device serves as a useful benchmark and still is used in special instances where its large, sensitive depth is essential. Semiconductor X-Ray Detectors focuses on the history and development of Si(Li) X-Ray Detect...

  9. X-ray diffraction apparatus

    International Nuclear Information System (INIS)

    The invention provides an x-ray diffraction apparatus permitting the rotation of the divergence sit in conjunction with the rotation of the x-ray irradiated specimen, whereby the dimensions of the x-ray irradiated portion of the specimen remain substantially constant during the rotation of the specimen. In a preferred embodiment, the divergence slit is connected to a structural element linked with a second structural element connected to the specimen such that the divergence slit rotates at a lower angular speed than the specimen

  10. Two digital X-ray imaging systems for applications in X-ray diffraction

    International Nuclear Information System (INIS)

    Two digital X-ray imaging systems developed at the Rutherford Appleton Laboratory are described:- the Mark I and the Mark II. Both use a bidimensionally sensitive Multiwire proportional counter as the basic X-ray image transducer coupled to a digital microcomputer system. The Mark I system provides the advantages of high speed, high sensitivity digital imaging directly into the computer with the potential for software control of the sample orientation and environment. The Mark II system adds the novel features of signal averaging and multi-frame exposures. (author)

  11. High Resolution X-ray-Induced Acoustic Tomography

    Science.gov (United States)

    Xiang, Liangzhong; Tang, Shanshan; Ahmad, Moiz; Xing, Lei

    2016-05-01

    Absorption based CT imaging has been an invaluable tool in medical diagnosis, biology, and materials science. However, CT requires a large set of projection data and high radiation dose to achieve superior image quality. In this letter, we report a new imaging modality, X-ray Induced Acoustic Tomography (XACT), which takes advantages of high sensitivity to X-ray absorption and high ultrasonic resolution in a single modality. A single projection X-ray exposure is sufficient to generate acoustic signals in 3D space because the X-ray generated acoustic waves are of a spherical nature and propagate in all directions from their point of generation. We demonstrate the successful reconstruction of gold fiducial markers with a spatial resolution of about 350 μm. XACT reveals a new imaging mechanism and provides uncharted opportunities for structural determination with X-ray.

  12. Skeletal deformations of newborn mice after X-ray exposure in fetal stage, with particular regard to hyperplastic growth phenomena in the neurocranium

    International Nuclear Information System (INIS)

    The following comprises a literary review of the effects of prenatal X-ray irradiation, known mainly from the mouse. Our own investigations were carried out with NMRI mice which on gestation days 11-13, 11-16 or 14-16 were exposed to whole-body irradiation comprising individual daily doses of between 80 and 160 R. All the examinations were carried out on the 18th day of gestation. Findings of special nature were ascertained on the talus and calcaneus. These bones indicate that the X-ray irradiation has an accelerating effect on development. It was possible to ascertain a corresponding effect with regard to the deformations of the os supraoccipital. After irradiation with 3 x 120 R and 3 x 160 R on the 11th-13th gestation days, both inhibitory deformities and also the occurence of an additional, novel bone anlage were observed. These findings were subjected to detailed histological examinations. In doing so, it was found that following a single irradiation with 200 R on the 12th day of gestation, 86,6% of the fetuses showed hyperostoses on the roof of the skull. In 13,2% of all cases there was in addition a clear, abnormal chondrification of the neurocranium, at the same time combined with an excessive formation of the bone, which protruded deep into the cerebral hemispheres. The patogeneses of this excessive growth phenomenon is explained on the basis of the complex relationship between the fetal brain formation and the formation of the skull cap. (orig./AJ)

  13. Duodenal X-ray diagnostics

    International Nuclear Information System (INIS)

    The publication provides an overview of duodenal X-ray diagnostics with the aid of barium meals in 1362 patients. The introducing paragraphs deal with the topographic anatomy of the region and the methodics of X-ray investigation. The chapter entitled ''processes at the duodenum itself'' describes mainly ulcers, diverticula, congenital anomalies, tumors and inflammations. The neighbourhood processes comprise in the first place diseases having their origin at the pancreas and bile ducts. As a conclusion, endoscopic rectograde cholangio-pancreaticography and percutaneous transhepatic cholangiography are pointed out as advanced X-ray investigation methods. In the annex of X-ray images some of the described phenomena are shown in exemplary manner. (orig./MG)

  14. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... like a photographic negative). Today, most images are digital files that are stored electronically. These stored images ... and places the x-ray film holder or digital recording plate under the table in the area ...

  15. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... pregnant. Many imaging tests are not performed during pregnancy so as not to expose the fetus to ... See the Safety page for more information about pregnancy and x-rays. top of page What does ...

  16. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... the baby. See the Safety page for more information about pregnancy and x-rays. top of page ... procedure varies. See the Safety page for more information about radiation dose. Women should always inform their ...

  17. X-ray microtomographic scanners

    Energy Technology Data Exchange (ETDEWEB)

    Syryamkin, V. I., E-mail: klestov-simon@mail.ru; Klestov, S. A., E-mail: klestov-simon@mail.ru [National Research Tomsk State University, Tomsk, 634050 (Russian Federation)

    2015-11-17

    The article studies the operating procedures of an X-ray microtomographic scanner and the module of reconstruction and analysis 3D-image of a test sample in particular. An algorithm for 3D-image reconstruction based on image shadow projections and mathematical methods of the processing are described. Chapter 1 describes the basic principles of X-ray tomography and general procedures of the device developed. Chapters 2 and 3 are devoted to the problem of resources saving by the system during the X-ray tomography procedure, which is achieved by preprocessing of the initial shadow projections. Preprocessing includes background noise removing from the images, which reduces the amount of shadow projections in general and increases the efficiency of the group shadow projections compression. In conclusion, the main applications of X-ray tomography are presented.

  18. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... top of page What are the benefits vs. risks? Benefits Bone x-rays are the fastest and ... in the typical diagnostic range for this exam. Risks There is always a slight chance of cancer ...

  19. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... can be taken to the patient in a hospital bed or the emergency room. The x-ray ... and international radiology protection organizations continually review and update the technique standards used by radiology professionals. Modern ...

  20. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... the patient in a hospital bed or the emergency room. The x-ray tube is connected to ... equipment is relatively inexpensive and widely available in emergency rooms, physician offices, ambulatory care centers, nursing homes ...

  1. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... or in bones. top of page How should I prepare? Most bone x-rays require no special ... to 10 minutes. top of page What will I experience during and after the procedure? A bone ...

  2. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... the body absorb the x-rays in varying degrees. Dense bone absorbs much of the radiation while ... is further reviewed by committees from the American College of Radiology (ACR) and the Radiological Society of ...

  3. Dental X-ray apparatus

    International Nuclear Information System (INIS)

    Intra-oral dental X-ray apparatus for panoramic dental radiography is described in detail. It comprises an electron gun having an elongated tubular target carrier extending into the patient's mouth. The carrier supports an inclined target for direction of an X-ray pattern towards a film positioned externally of the patient's mouth. Image definition is improved by a focusing anode which focuses the electron beam into a sharp spot (0.05 to 0.10 mm diameter) on the target. The potential on the focusing anode is adjustable to vary the size of the spot. An X-ray transmitting ceramic (oxides of Be, Al and Si) window is positioned adjacent to the front face of the target. The electron beam can be magnetically deflected to change the X-ray beam direction. (author)

  4. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... during x-ray examinations to use the lowest radiation dose possible while producing the best images for evaluation. National and international radiology protection organizations continually review and update the technique standards ...

  5. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... technologist, an individual specially trained to perform radiology examinations, positions the patient on the x-ray table ... bone is forming), for comparison purposes. When the examination is complete, you may be asked to wait ...

  6. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... replacement and fracture reductions. look for injury, infection, arthritis , abnormal bone growths and bony changes seen in ... injuries, including fractures, and joint abnormalities, such as arthritis. X-ray equipment is relatively inexpensive and widely ...

  7. X-Ray Assembler Data

    Data.gov (United States)

    U.S. Department of Health & Human Services — Federal regulations require that an assembler who installs one or more certified components of a diagnostic x-ray system submit a report of assembly. This database...

  8. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... a large photographic negative). Today, most images are digital files that are stored electronically. These stored images ... and places the x-ray film holder or digital recording plate under the table in the area ...

  9. Pathogenic mechanism in lung fibrosis. [Synergistic effects of BHT, O/sub 2/, and x rays in mice

    Energy Technology Data Exchange (ETDEWEB)

    Witschi, H.; Haschek, W. M.; Meyer, K. R.; Ullrich, R. L.; Dalbey, W. E.

    1979-01-01

    The purpose of the study was to examine whether an interaction between two agents causing alveolar epithelial damage would produce lung fibrosis. In mouse lung, intraperitoneal injection of the antioxidant butylated hydroxytoluene causes diffuse alveolar type I cell necrosis, followed by proliferation of type II alveolar cells. In animals exposed to 70% O/sub 2/ or 100-200 rad x rays during the phase of type II cell proliferation following BHT, diffuse interstitial lung fibrosis developed within 2 weeks. Quantitative analysis of the lungs for hydroxyproline showed that the interaction between BHT and O/sub 2/ or x rays was synergistic. If exposure to O/sub 2/ or x rays was delayed until epithelial recovery was complete, no fibrosis was seen. Abnormally high levels of lung collagen persisted up to 6 months after one single treatment with BHT and 100 rad x rays. A commonly seen form of chronic lung damage may thus be caused by an acute interaction between a bloodborne agent which damages the alveolar cell and a toxic inhalant or x rays, provided a critically ordered sequence of exposure is observed.

  10. Accelerator x-ray sources

    CERN Document Server

    Talman, Richard

    2007-01-01

    This first book to cover in-depth the generation of x-rays in particle accelerators focuses on electron beams produced by means of the novel Energy Recovery Linac (ERL) technology. The resulting highly brilliant x-rays are at the centre of this monograph, which continues where other books on the market stop. Written primarily for general, high energy and radiation physicists, the systematic treatment adopted by the work makes it equally suitable as an advanced textbook for young researchers.

  11. X-ray fluorescence holography

    CERN Document Server

    Hayashi, K; Takahashi, Y

    2003-01-01

    X-ray fluorescence holography (XFH) is a new structural analysis method of determining a 3D atomic arrangement around fluorescing atoms. We developed an XFH apparatus using advanced X-ray techniques and succeeded in obtaining high-quality hologram data. Furthermore, we introduced applications to the structural analysis of a thin film and the environment around dopants and, discussed the quantitative analysis of local lattice distortion. (author)

  12. Electromechanical x-ray generator

    Energy Technology Data Exchange (ETDEWEB)

    Watson, Scott A; Platts, David; Sorensen, Eric B

    2016-05-03

    An electro-mechanical x-ray generator configured to obtain high-energy operation with favorable energy-weight scaling. The electro-mechanical x-ray generator may include a pair of capacitor plates. The capacitor plates may be charged to a predefined voltage and may be separated to generate higher voltages on the order of hundreds of kV in the AK gap. The high voltage may be generated in a vacuum tube.

  13. X-ray diagnostic apparatus

    International Nuclear Information System (INIS)

    A falling load type X-ray diagnostic apparatus comprises a low voltage power source, AC-DC converting means connected to the low voltage power source so as to apply a rectified low DC voltage, chopping means connected to the AC-DC converting means and chopping said DC voltage into a low AC voltage, high voltage applying means for transforming said low AC voltage into a high AC voltage, said high AC voltage being applied as a tube voltage to an X-ray tube from which X-rays are irradiated toward an object to be examined, means for controlling a filament heating power of the X-ray tube, programming means for supplying a control signal to said filament heating control means so as to reduce the emission current of said X-ray tube during the irradiation, and chopper control means for controlling the chopping ratio of said chopping means by evaluating said rectified DC voltage with a preset tube voltage generated in said programming means, said programming means compensating said tube voltage by receiving said control signal in such a manner that said tube voltage is maintained substantially constant during the irradiation by varying said preset tube voltage so as to control the chopping ratio based upon the reduction of the filament heating power for the X-ray tube

  14. Center for X-Ray Optics, 1992

    International Nuclear Information System (INIS)

    This report discusses the following topics: Center for X-Ray Optics; Soft X-Ray Imaging wit Zone Plate Lenses; Biological X-Ray microscopy; Extreme Ultraviolet Lithography for Nanoelectronic Pattern Transfer; Multilayer Reflective Optics; EUV/Soft X-ray Reflectometer; Photoemission Microscopy with Reflective Optics; Spectroscopy with Soft X-Rays; Hard X-Ray Microprobe; Coronary Angiography; and Atomic Scattering Factors

  15. Image formation in diagnostic X-ray equipment

    International Nuclear Information System (INIS)

    This thesis deals with a physical description of the image formation in static radiographic shadow image X-ray equipment and an analysis of the optimization of such systems. For the latter criteria have been developed that take into account all relevant physical phenomena that relate to properties of the image and the radiation exposure of the patient. The discussion of image formation results in a number of relations between the X-ray system parameters on the one hand and properties of the X-ray image on the other. The three principal aspects considered are energy transfer, modulation transfer and noise. (Auth./C.F.)

  16. Dosages of ionizing radiation during limb diagnostic X-ray examinations

    OpenAIRE

    Marcin Bekas; Krzysztof A. Pachocki; Elżbieta Waśniewska; Dagmara Bogucka; Andrzej Magiera

    2016-01-01

    Background: X-ray examination is associated with the patient’s exposure to ionizing radiation. The dose values depend on the type of the medical procedure used, the X-ray unit technical condition and exposure conditions selected by X-ray technicians. The aim of this study has been to assess the entrance surface dose (ESD) values received by patients during the limb X-ray examination. The results should help doctors in making the decision about sending patients for X-ray examination. At the sa...

  17. The peculiar optical-UV X-ray spectra of the X-ray weak quasar PG 0043+039

    CERN Document Server

    Kollatschny, W; Zetzl, M; Santos-Lleó, M; Rodríguez-Pascual, P M; Ballo, L; Talavera, A

    2016-01-01

    The object PG 0043+039 has been identified as a broad absorption line (BAL) quasar based on its UV spectra. However, this optical luminous quasar has not been detected before in deep X-ray observations, making it the most extreme X-ray weak quasar known today. This study aims to detect PG 0043+039 in a deep X-ray exposure. The question is what causes the extreme X-ray weakness of PG 0043+039? Does PG 0043+039 show other spectral or continuum peculiarities? We took simultaneous deep X-ray spectra with XMM-Newton, far-ultraviolet (FUV) spectra with the Hubble Space Telescope (HST) and optical spectra of PG 0043+039 with the Hobby-Eberly Telescope (HET) and Southern African Large Telescope (SALT) in July, 2013. We have detected PG 0043+039 in our X-ray exposure taken in 2013. We presented our first results in a separate paper (Kollatschny et al. 2015). PG 0043+039 shows an extreme {\\alpha}_ox gradient ({\\alpha}_ox =-2.37). Furthermore, we were able to verify an X-ray flux of this source in a reanalysis of the X-...

  18. X-ray Echo Spectroscopy

    Science.gov (United States)

    Shvyd'ko, Yuri

    2016-02-01

    X-ray echo spectroscopy, a counterpart of neutron spin echo, is being introduced here to overcome limitations in spectral resolution and weak signals of the traditional inelastic x-ray scattering (IXS) probes. An image of a pointlike x-ray source is defocused by a dispersing system comprised of asymmetrically cut specially arranged Bragg diffracting crystals. The defocused image is refocused into a point (echo) in a time-reversal dispersing system. If the defocused beam is inelastically scattered from a sample, the echo signal acquires a spatial distribution, which is a map of the inelastic scattering spectrum. The spectral resolution of the echo spectroscopy does not rely on the monochromaticity of the x rays, ensuring strong signals along with a very high spectral resolution. Particular schemes of x-ray echo spectrometers for 0.1-0.02 meV ultrahigh-resolution IXS applications (resolving power >108 ) with broadband ≃5 - 13 meV dispersing systems are introduced featuring more than 103 signal enhancement. The technique is general, applicable in different photon frequency domains.

  19. X-ray echo spectroscopy

    CERN Document Server

    Shvyd'ko, Yuri

    2015-01-01

    X-ray echo spectroscopy, a counterpart of neutron spin-echo, is being introduced here to overcome limitations in spectral resolution and weak signals of the traditional inelastic x-ray scattering (IXS) probes. An image of a point-like x-ray source is defocused by a dispersing system comprised of asymmetrically cut specially arranged Bragg diffracting crystals. The defocused image is refocused into a point (echo) in a time-reversal dispersing system. If the defocused beam is inelastically scattered from a sample, the echo signal acquires a spatial distribution, which is a map of the inelastic scattering spectrum. The spectral resolution of the echo spectroscopy does not rely on the monochromaticity of the x-rays, ensuring strong signals along with a very high spectral resolution. Particular schemes of x-ray echo spectrometers for 0.1--0.02-meV ultra-high-resolution IXS applications (resolving power $> 10^8$) with broadband $\\simeq$~5--13~meV dispersing systems are introduced featuring more than $10^3$ signal e...

  20. X-ray Echo Spectroscopy.

    Science.gov (United States)

    Shvyd'ko, Yuri

    2016-02-26

    X-ray echo spectroscopy, a counterpart of neutron spin echo, is being introduced here to overcome limitations in spectral resolution and weak signals of the traditional inelastic x-ray scattering (IXS) probes. An image of a pointlike x-ray source is defocused by a dispersing system comprised of asymmetrically cut specially arranged Bragg diffracting crystals. The defocused image is refocused into a point (echo) in a time-reversal dispersing system. If the defocused beam is inelastically scattered from a sample, the echo signal acquires a spatial distribution, which is a map of the inelastic scattering spectrum. The spectral resolution of the echo spectroscopy does not rely on the monochromaticity of the x rays, ensuring strong signals along with a very high spectral resolution. Particular schemes of x-ray echo spectrometers for 0.1-0.02 meV ultrahigh-resolution IXS applications (resolving power >10^{8}) with broadband ≃5-13  meV dispersing systems are introduced featuring more than 10^{3} signal enhancement. The technique is general, applicable in different photon frequency domains.

  1. In Vivo Nanodetoxication for Acute Uranium Exposure

    Directory of Open Access Journals (Sweden)

    Luis Guzmán

    2015-06-01

    Full Text Available Accidental exposure to uranium is a matter of concern, as U(VI is nephrotoxic in both human and animal models, and its toxicity is associated to chemical toxicity instead of radioactivity. We synthesized different PAMAM G4 and G5 derivatives in order to prove their interaction with uranium and their effect on the viability of red blood cells in vitro. Furthermore, we prove the effectiveness of the selected dendrimers in an animal model of acute uranium intoxication. The dendrimer PAMAM G4-Lys-Fmoc-Cbz demonstrated the ability to chelate the uranyl ion in vivo, improving the biochemical and histopathologic features caused by acute intoxication with uranium.

  2. Medical x-ray-sensitive array based on CCD

    Science.gov (United States)

    Gnedenko, Valeri G.; Krasnjuk, Andrey A.; Larionov, Sergei V.; Phainberg, Evgeni M.; Shilin, Victor A.; Skrylev, Alexander S.; Stenin, Vladimir J.

    1996-04-01

    The achievements of CCD technology allow to design X-ray sensitive solid-state images for various medicine applications. The first medical systems have been created for using in dental practice and diagnosis. This radiovisiographic method allows to reduce X-ray exposure by 80%, except any films and provide paralleled diagnosis capacities which revolutionize every day practice. In the future a mosaic scanner with CCD chips will be used for detecting breast cancer.

  3. Radiation doses for X-ray diagnosis teeth in dental medicine

    International Nuclear Information System (INIS)

    X-rays are the first ionizing radiation, which are applied in medicine for diagnostic radiology and X-ray therapy. While in the beginning they are mainly used for X-ray photos of the chest /lungs and in severe fractures of the limbs, then in recent years they are widely applied in diagnostics of teeth in dental medicine. Considering that caries is a widespread disease, both in children and adults, and it requires repeated x-ray photographs of the damaged teeth for the individual, the total radiation doses, which reflect on people from the X-rays are at high values. In order to reduce external exposure to other organs /mainly thyroid gland/ by X-ray pictures of teeth, it should be used with special lead aprons with large coefficient of reduction. Keywords: doses of radiation, X-ray machines, dental, x-ray pictures of teeth, protection sources

  4. Quality assurance in X-ray mammography

    International Nuclear Information System (INIS)

    Full text: Introduction: Breast Cancer (BC) is the most common cancer in the country, with a smooth upward trend. X-ray mammography is the gold standard in the diagnosis of breast cancer. The study was carried out with X-ray radiation with certain degree of risk of radiation carcinogenesis in a patient. There are international recommendations setting high requirements for the quality of mammography. What you will learn: In 2006 the fourth edition of the European recommendations for ensuring quality in screening and diagnosis of breast cancer was published. It stipulates the requirements to both technical and physical aspects of mammography screening and the quality of work of the radiologist, technologist, pathologist and surgeon. Some multidisciplinary aspects of quality assurance in the diagnostic process are discussed. Discussion: Some often neglected aspects in quality are discussed. A standard plexiglas phantom for each mammography system for daily tests holding of image quality and dose evaluation is necessary. In the dark room appropriate equipment for assessment of the developing process has be available, as often it is the main reason for the poor quality of the mammographic images. In digital mammography the conditions for mammograms reading - light and brightness of the room and equipment and monitor quality are neglected. Conclusion: One of the basic principles of radiation protection in diagnostic radiology required to obtain images with the necessary diagnostic information with minimal exposure to the patient. This is possible only in compliance with all aspects of quality assurance in X-ray mammography

  5. A simulator for X-ray images

    International Nuclear Information System (INIS)

    A simulator for X-ray images is presented based on a virtual X-ray source and a virtual human body obtained from tomographic slices. In the simulator it is possible to modify the tube potential, the anodic current, the exposure time, the filtration and some geometric parameters such as source-skin distance, orientation and field size. The virtual body consists of a three-dimensional voxel matrix in which CT numbers for each point of the body are stored. The interactions of X rays passing through the body are evaluated using the pencil beam technique. The image is obtained by computing the dose absorbed by the detector and converting it into optical density using a proper response function. The image spatial resolution is limited by the voxel size. The influence of each parameter on the image quality can be observed interactively. The dose absorbed in each point of the body is an important parameter obtained as output of the simulator. (authors)

  6. Observation of acute radiation damage on mice exposed to X-rays%X射线致小鼠急性损伤的观察

    Institute of Scientific and Technical Information of China (English)

    何火聪; 吴君心; 苏颖; 潘剑茹; 郑光进; 刘树滔

    2012-01-01

    本研究用6GyX射线对小鼠进行全身一次性照射,分别在照射后l、3和7d经颈椎脱臼处死,测定小鼠外周血红、白细胞数量,胸腺指数和脾脏指数,骨髓嗜多染红细胞微核形成率以及肝脏抗氧化水平.结果表明:照射24 h后,小鼠外周血白细胞数量急剧降低,胸腺指数和脾脏指数下降,骨髓嗜多染红细胞微核形成率增加,肝脏脂质过氧化水平上升.放射7d后,胸腺指数稍有回升,骨髓红细胞微核形成率和肝脏脂质过氧化水平略为降低,其它指标随时间变化损伤程度持续增加.%Mice were whole-body exposed to X-rays with absorbed dose of 6 Gy and sacrificed on the 1st, 3rd and 7th day by cervical dislocation after irradiation, respectively. The number of red blood cells and white blood cells in peripheral blood, the index of thymus and spleen, the micronucleus rate of bone marrow polychromatic erythro-blasts (PCE) and the level of antioxidant of liver were determined. It was observed that white blood cells decreased, the index of thymus and spleen also decreased meanwhile both of the micronucleus rate of bone marrow PCE and level of lipid peroxidation of liver increased at 24 h after irradiation. However, the index of thymus was up slightly on the 7th day after irradiation, while the PCE and the level of lipid peroxidation of liver got down slightly. The other index of injured mice increased continually with time.

  7. X-ray imaging: Perovskites target X-ray detection

    Science.gov (United States)

    Heiss, Wolfgang; Brabec, Christoph

    2016-05-01

    Single crystals of perovskites are currently of interest to help fathom fundamental physical parameters limiting the performance of perovskite-based polycrystalline solar cells. Now, such perovskites offer a technology platform for optoelectronic devices, such as cheap and sensitive X-ray detectors.

  8. 急性血行播散型肺结核X线平片分析%Acute Hematogenous disseminated pulmonary tuberculosis x ray analysis

    Institute of Scientific and Technical Information of China (English)

    王志翔; 周广德

    2015-01-01

    Objective The acute blood line spreads pulmonary tuberculosis clinically in more common, in X even piece diagnosis fills the air with lungs some venereal diseases to confuse in disguised form frequently.This article reported 28 examples, discussed the acute blood line to spread the pulmonary tuberculosis main performance, as well as with silicosis, miliary pneumonia X even piece of distinction diagnosis main points.%急性血行播散型肺结核在临床较为常见,X线平片诊断中经常与肺部一些弥漫性病变相混淆.本文报告28例,讨论了急性血行播散型肺结核的主要表现,以及与矽肺、粟粒性肺炎等肺部弥漫性病变的X平片的鉴别诊断要点.

  9. Simple, compact, high brightness source for x-ray lithography and x-ray radiography

    International Nuclear Information System (INIS)

    A simple, compact, high brightness x-ray source has recently been built. This source utilizes a commercially available, cylindrical geometry electron beam evaporator, which has been modified to enhance the thermal cooling to the anode. Cooling is accomplished by using standard, low-conductivity laboratory water, with an inlet pressure of less than 50 psi, and a flow rate of approx.0.3 gal/min. The anode is an inverted cone geometry for efficient cooling. The x-ray source has a measured sub-millimeter spot size (FWHM). The anode has been operated at 1 KW e-beam power (10 KV, 100 ma). Higher operating levels will be investigated. A variety of different x-ray lines can be obtained by the simple interchange of anodes of different materials. Typical anodes are made from easily machined metals, or materials which are vacuum deposited onto a copper anode. Typically, a few microns of material is sufficient to stop 10 KV electrons without significantly decreasing the thermal conductivity through the anode. The small size and high brightness of this source make it useful for step and repeat exposures over several square centimeter areas, especially in a research laboratory environment. For an aluminum anode, the estimated Al-K x-ray flux at 10 cms from the source is 70 μW/cm2

  10. X-ray hot plasma diagnostics

    International Nuclear Information System (INIS)

    X-ray plasma emission study is powerful diagnostic tool of hot plasmas. In this review article the main techniques of X-ray plasma emission measurement are shortly presented: X-ray spectrometry using absorbent filters, crystal and grating spectrometers, imaging techniques using pinhole cameras, X-ray microscopes and Fresnel zone plate cameras, X-ray plasma emission calorimetry. Advances in these techniques with examples for different hot plasma devices are also presentes. (author)

  11. X-ray fluorescence spectrometry

    International Nuclear Information System (INIS)

    The seventh edition of Philips' Review of Literature on x-ray fluorescence spectrometry starts with a list of conference proceedings on the subject, organised by the Philips organisation at regular intervals in various European countries. It is followed by a list of bulletins. The bibliography is subdivided according to spectra, equipment, applications and absorption analysis

  12. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... Images related to X-ray (Radiography) - Bone About this Site RadiologyInfo.org is produced by: Please note ... you can search the ACR-accredited facilities database . This website does not provide cost information. The costs ...

  13. X-ray backscatter imaging

    Science.gov (United States)

    Dinca, Dan-Cristian; Schubert, Jeffrey R.; Callerame, J.

    2008-04-01

    In contrast to transmission X-ray imaging systems where inspected objects must pass between source and detector, Compton backscatter imaging allows both the illuminating source as well as the X-ray detector to be on the same side of the target object, enabling the inspection to occur rapidly and in a wide variety of space-constrained situations. A Compton backscatter image is similar to a photograph of the contents of a closed container, taken through the container walls, and highlights low atomic number materials such as explosives, drugs, and alcohol, which appear as especially bright objects by virtue of their scattering characteristics. Techniques for producing X-ray images based on Compton scattering will be discussed, along with examples of how these systems are used for both novel security applications and for the detection of contraband materials at ports and borders. Differences between transmission and backscatter images will also be highlighted. In addition, tradeoffs between Compton backscatter image quality and scan speed, effective penetration, and X-ray source specifications will be discussed.

  14. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available Toggle navigation Test/Treatment Patient Type Screening/Wellness Disease/Condition Safety En Español More Info Images/Videos News Physician Resources Professions Site Index A-Z X-ray (Radiography) - Bone ...

  15. X-Ray Diffractive Optics

    Science.gov (United States)

    Dennis, Brian; Li, Mary; Skinner, Gerald

    2013-01-01

    X-ray optics were fabricated with the capability of imaging solar x-ray sources with better than 0.1 arcsecond angular resolution, over an order of magnitude finer than is currently possible. Such images would provide a new window into the little-understood energy release and particle acceleration regions in solar flares. They constitute one of the most promising ways to probe these regions in the solar atmosphere with the sensitivity and angular resolution needed to better understand the physical processes involved. A circular slit structure with widths as fine as 0.85 micron etched in a silicon wafer 8 microns thick forms a phase zone plate version of a Fresnel lens capable of focusing approx. =.6 keV x-rays. The focal length of the 3-cm diameter lenses is 100 microns, and the angular resolution capability is better than 0.1 arcsecond. Such phase zone plates were fabricated in Goddard fs Detector Development Lab. (DDL) and tested at the Goddard 600-microns x-ray test facility. The test data verified that the desired angular resolution and throughput efficiency were achieved.

  16. X-ray film processing

    International Nuclear Information System (INIS)

    X-ray films have to be highly sensitive, for radiation protection reasons. The films used in radiology are coated on both sides with a photosensitive emulsion. This applies to all dental films. Their properties and the development of the different exposed films are explained. (DG)

  17. X-rays and magnetism.

    Science.gov (United States)

    Fischer, Peter; Ohldag, Hendrik

    2015-09-01

    Magnetism is among the most active and attractive areas in modern solid state physics because of intriguing phenomena interesting to fundamental research and a manifold of technological applications. State-of-the-art synthesis of advanced magnetic materials, e.g. in hybrid structures paves the way to new functionalities. To characterize modern magnetic materials and the associated magnetic phenomena, polarized x-rays have emerged as unique probes due to their specific interaction with magnetic materials. A large variety of spectroscopic and microscopic techniques have been developed to quantify in an element, valence and site-sensitive way properties of ferro-, ferri-, and antiferromagnetic systems, such as spin and orbital moments, and to image nanoscale spin textures and their dynamics with sub-ns time and almost 10 nm spatial resolution. The enormous intensity of x-rays and their degree of coherence at next generation x-ray facilities will open the fsec time window to magnetic studies addressing fundamental time scales in magnetism with nanometer spatial resolution. This review will give an introduction into contemporary topics of nanoscale magnetic materials and provide an overview of analytical spectroscopy and microscopy tools based on x-ray dichroism effects. Selected examples of current research will demonstrate the potential and future directions of these techniques.

  18. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... over time. top of page What are the benefits vs. risks? Benefits Bone x-rays are the fastest and easiest ... evaluation. National and international radiology protection organizations continually review and update the technique standards used by radiology ...

  19. High-Resolution X-ray Emission and X-ray Absorption Spectroscopy

    OpenAIRE

    de Groot, F. M. F.

    2001-01-01

    In this review, high-resolution X-ray emission and X-ray absorption spectroscopy will be discussed. The focus is on the 3d transition-metal systems. To understand high-resolution X-ray emission and reso-nant X-ray emission, it is first necessary to spend some time discussing the X-ray absorption process. Section II discusses 1s X-ray absorption, i.e., the K edges, and section III deals with 2p X-ray absorption, the L edges. X-ray emission is discussed in, respectively, the L edges. X-ray emis...

  20. High-Resolution X-ray Emission and X-ray Absorption Spectroscopy

    NARCIS (Netherlands)

    Groot, F.M.F. de

    2001-01-01

    In this review, high-resolution X-ray emission and X-ray absorption spectroscopy will be discussed. The focus is on the 3d transition-metal systems. To understand high-resolution X-ray emission and reso-nant X-ray emission, it is first necessary to spend some time discussing the X-ray absorption pro

  1. Dosimetry of x-ray beams: The measure of the problem

    International Nuclear Information System (INIS)

    This document contains the text of an oral presentation on dosimetry of analytical x-ray equipment presented at the Denver X-Ray Conference. Included are discussions of sources of background radiation, exposure limits from occupational sources, and the relationship of these sources to the high dose source of x-rays found in analytical machines. The mathematical basis of x-ray dosimetry is reviewed in preparation for more detailed notes on personnel dosimetry and the selection of the most appropriate dosimeter for a specific application. The presentation concludes with a discussion common to previous x-ray equipment accidents. 2 refs

  2. Prenatal pesticide exposure and PON1 genotype associated with adolescent body fat distribution evaluated by dual X-ray absorptiometry (DXA)

    DEFF Research Database (Denmark)

    Tinggaard, J; Wohlfahrt-Veje, C; Husby, S;

    2016-01-01

    ) at age 10-15. Prenatal pesticide exposure was associated with increased total, android, and gynoid fat% (DXA) at age 10-15 years after adjustment for sex, socioeconomic status, and puberty (all β = 0.5 standard deviation score (SDS) p ... (total fat: β = 0.7 SDS, android-gynoid ratio: β = 0.1, both p ... circumference were found. Prenatal pesticide exposure was associated with higher adolescent body fat content, including android fat deposition, independent of puberty. Girls appeared more susceptible than boys. Furthermore, the association depended on maternal and child PON1 Q192R genotype....

  3. Combined Exposure to Simulated Microgravity and Acute or Chronic Radiation Reduces Neuronal Network Integrity and Survival.

    Directory of Open Access Journals (Sweden)

    Giuseppe Pani

    Full Text Available During orbital or interplanetary space flights, astronauts are exposed to cosmic radiations and microgravity. However, most earth-based studies on the potential health risks of space conditions have investigated the effects of these two conditions separately. This study aimed at assessing the combined effect of radiation exposure and microgravity on neuronal morphology and survival in vitro. In particular, we investigated the effects of simulated microgravity after acute (X-rays or during chronic (Californium-252 exposure to ionizing radiation using mouse mature neuron cultures. Acute exposure to low (0.1 Gy doses of X-rays caused a delay in neurite outgrowth and a reduction in soma size, while only the high dose impaired neuronal survival. Of interest, the strongest effect on neuronal morphology and survival was evident in cells exposed to microgravity and in particular in cells exposed to both microgravity and radiation. Removal of neurons from simulated microgravity for a period of 24 h was not sufficient to recover neurite length, whereas the soma size showed a clear re-adaptation to normal ground conditions. Genome-wide gene expression analysis confirmed a modulation of genes involved in neurite extension, cell survival and synaptic communication, suggesting that these changes might be responsible for the observed morphological effects. In general, the observed synergistic changes in neuronal network integrity and cell survival induced by simulated space conditions might help to better evaluate the astronaut's health risks and underline the importance of investigating the central nervous system and long-term cognition during and after a space flight.

  4. Combined Exposure to Simulated Microgravity and Acute or Chronic Radiation Reduces Neuronal Network Integrity and Survival.

    Science.gov (United States)

    Pani, Giuseppe; Verslegers, Mieke; Quintens, Roel; Samari, Nada; de Saint-Georges, Louis; van Oostveldt, Patrick; Baatout, Sarah; Benotmane, Mohammed Abderrafi

    2016-01-01

    During orbital or interplanetary space flights, astronauts are exposed to cosmic radiations and microgravity. However, most earth-based studies on the potential health risks of space conditions have investigated the effects of these two conditions separately. This study aimed at assessing the combined effect of radiation exposure and microgravity on neuronal morphology and survival in vitro. In particular, we investigated the effects of simulated microgravity after acute (X-rays) or during chronic (Californium-252) exposure to ionizing radiation using mouse mature neuron cultures. Acute exposure to low (0.1 Gy) doses of X-rays caused a delay in neurite outgrowth and a reduction in soma size, while only the high dose impaired neuronal survival. Of interest, the strongest effect on neuronal morphology and survival was evident in cells exposed to microgravity and in particular in cells exposed to both microgravity and radiation. Removal of neurons from simulated microgravity for a period of 24 h was not sufficient to recover neurite length, whereas the soma size showed a clear re-adaptation to normal ground conditions. Genome-wide gene expression analysis confirmed a modulation of genes involved in neurite extension, cell survival and synaptic communication, suggesting that these changes might be responsible for the observed morphological effects. In general, the observed synergistic changes in neuronal network integrity and cell survival induced by simulated space conditions might help to better evaluate the astronaut's health risks and underline the importance of investigating the central nervous system and long-term cognition during and after a space flight. PMID:27203085

  5. Center for X-Ray Optics, 1986

    International Nuclear Information System (INIS)

    The Center for X-Ray Optics has made substantial progress during the past year on the development of very high resolution x-ray technologies, the generation of coherent radiation at x-ray wavelengths, and, based on these new developments, had embarked on several scientific investigations that would not otherwise have been possible. The investigations covered in this report are topics on x-ray sources, x-ray imaging and applications, soft x-ray spectroscopy, synchrotron radiation, advanced light source and magnet structures for undulators and wigglers

  6. Soft x-ray tomoholography

    International Nuclear Information System (INIS)

    We demonstrate an x-ray imaging method that combines Fourier transform holography with tomography (‘tomoholography’) for three-dimensional (3D) microscopic imaging. A 3D image of a diatom shell with a spatial resolution of 140 nm is presented. The experiment is realized by using a small gold sphere as the reference wave source for holographic imaging. This setup allows us to rotate the sample and to collect a number of 2D projections for tomography. (paper)

  7. Soft x-ray tomoholography

    OpenAIRE

    Guehrs, E.; Stadler, A.M.; Flewett, S.; Frömmel, S.; Geilhufe, J.; Pfau, B; Rander, T.; Schaffert, S.; Büldt, G; Eisebitt, S.

    2012-01-01

    We demonstrate an x-ray imaging method that combines Fourier transform holography with tomography ('tomoholography') for three-dimensional (3D) microscopic imaging. A 3D image of a diatom shell with a spatial resolution of 140 nm is presented. The experiment is realized by using a small gold sphere as the reference wave source for holographic imaging. This setup allows us to rotate the sample and to collect a number of 2D projections for tomography.

  8. X-ray tube arrangements

    International Nuclear Information System (INIS)

    A technique for ensuring the rapid correction of both amplitude and offset errors in the deflectional movement of an electron beam along an X-ray emissive target is described. The movement is monitored at at least two positions during a sweep and differences, between the two movements and a desired movement, at these positions are combined in different proportions to produce a corrective servo signal. Such arrangements find application, for example, in computerised tomographic scanners. (author)

  9. Findings in children after radiation exposure in utero from X-ray examination of mothers. Results from children studied after one to seven years

    International Nuclear Information System (INIS)

    In the Nuclear Safety and Radiation Protection Board of the German Democratic Republic, a Central Advisory Centre headed by the author has been established to cover the problems of interruption or maintenance of pregnancy after radiation exposures in early pregnancy. So far more than 120 cases have been assessed. For the assessment, a detailed case history covering the occupation, family history and personal details of both parents was compiled, special attention being paid to hereditary diseases, deformations in the family and noxae that could also induce foetal damages (diseases, drugs, tobacco, etc.). The time of conception and foetal radiation exposure were determined as exactly as possible. Finally the foetal dose was measured at the phantom or calculated. In eight cases pregnancy was interrupted (foetal dose above 10 rem). Pathomorphological examination of foetal material showed developmental disturbances. Embryological examinations are in progress. All children are subjected to paediatric and laboratory examinations at fixed intervals up to their tenth year. In this way evidence on damage within a dose range below 10 rem will be obtained. The present results are obtained from children examined between one and seven years after radiation exposure in utero. In four cases, there were deviations from the norm in terms of deformations that could be surgically corrected. Noteworthy was a reduction in birth weight compared with the norm in 37% of cases, retarded bone development (carporadiogram) in 37% of cases and pronounced proneness to infection in 74% of cases. In addition, biochemical-genetic and cytogenetic examinations were made of 19 children who did not exhibit any deviations from the norm and represent the basic material for the future F1 generation

  10. X-Ray Crystallography Reagent

    Science.gov (United States)

    Morrison, Dennis R. (Inventor); Mosier, Benjamin (Inventor)

    2003-01-01

    Microcapsules prepared by encapsulating an aqueous solution of a protein, drug or other bioactive substance inside a semi-permeable membrane by are disclosed. The microcapsules are formed by interfacial coacervation under conditions where the shear forces are limited to 0-100 dynes per square centimeter at the interface. By placing the microcapsules in a high osmotic dewatering solution. the protein solution is gradually made saturated and then supersaturated. and the controlled nucleation and crystallization of the protein is achieved. The crystal-filled microcapsules prepared by this method can be conveniently harvested and stored while keeping the encapsulated crystals in essentially pristine condition due to the rugged. protective membrane. Because the membrane components themselves are x-ray transparent, large crystal-containing microcapsules can be individually selected, mounted in x-ray capillary tubes and subjected to high energy x-ray diffraction studies to determine the 3-D smucture of the protein molecules. Certain embodiments of the microcapsules of the invention have composite polymeric outer membranes which are somewhat elastic, water insoluble, permeable only to water, salts, and low molecular weight molecules and are structurally stable in fluid shear forces typically encountered in the human vascular system.

  11. X-ray-powered macronovae

    CERN Document Server

    Kisaka, Shota; Nakar, Ehud

    2015-01-01

    A macronova (or kilonova) was observed as an infrared excess several days after short gamma-ray burst, GRB 130603B. Although the $r$-process radioactivity is widely discussed as an energy source, it requires huge mass of ejecta from a neutron star (NS) binary merger. We propose that the X-ray excess simultaneously observed with the infrared excess can naturally heat the ejecta, leading to the thermal re-emission as observed in infrared. This X-ray-powered model explains both the X-ray and infrared excesses with a single energy source by the central engine like a black hole, and allows for broader parameter region, in particular smaller ejecta mass $\\sim10^{-3}-10^{-2}M_{\\odot}$ with iron mixed as suggested by general relativistic simulations for typical NS-NS mergers, than the previous models. We also discuss the other macronova candidates in GRB 060614 and GRB 080503, and implications for the search of electromagnetic counterparts to gravitational waves.

  12. X-Ray-powered Macronovae

    Science.gov (United States)

    Kisaka, Shota; Ioka, Kunihito; Nakar, Ehud

    2016-02-01

    A macronova (or kilonova) was observed as an infrared excess several days after the short gamma-ray burst GRB 130603B. Although the r-process radioactivity is widely discussed as an energy source, it requires a huge mass of ejecta from a neutron star (NS) binary merger. We propose a new model in which the X-ray excess gives rise to the simultaneously observed infrared excess via thermal re-emission, and explore what constraints this would place on the mass and velocity of the ejecta. This X-ray-powered model explains both the X-ray and infrared excesses with a single energy source such as the central engine like a black hole, and allows for a broader parameter region than the previous models, in particular a smaller ejecta mass ˜ {10}-3{--}{10}-2{M}⊙ and higher iron abundance mixed as suggested by general relativistic simulations for typical NS-NS mergers. We also discuss the other macronova candidates in GRB 060614 and GRB 080503, and the implications for the search of electromagnetic counterparts to gravitational waves.

  13. [The functional state of the mitochondrial respiratory chain of the small intestine enterocytes of the rats under the low dose rate X-ray total external exposure].

    Science.gov (United States)

    2013-01-01

    The influence of the low-rate ionizing radiation (0.055 Gy/min) at the doses of 0.1; 0.5 and 1.0 Gy on the functional state of the mitochondria respiratory chain of the rat small intestine enterocytes was investigated. The dysfunction of the electron transport chain enzymes andchanges in the content of cytochromes b, c, a in themitochondrial inner membrane were revealed 1, 12 and 24 hours after exposure to radiation. The re- vealed disorders indicate early membrane sensitivity to the radiation effect. The inhibition of the H+ -ATPase activity in the studied dose range indicates the decrease of the mitochondrial energy capacity. PMID:25508872

  14. Aspergillosis - chest x-ray (image)

    Science.gov (United States)

    ... usually occurs in immunocompromised individuals. Here, a chest x-ray shows that the fungus has invaded the lung ... are usually seen as black areas on an x-ray. The cloudiness on the left side of this ...

  15. Stabilized x-ray generator power supply

    International Nuclear Information System (INIS)

    X-ray diffraction and X-ray fluorescence analysis are very much adopted in laboratories to determine the type and structure of the constituent compounds in solid materials, chemical composition of materials, stress developed on metals etc. These experiments need X-ray beam of fixed intensity and wave length. This can only be achieved by X-ray generator having highly stabilized tube voltage and tube current. This paper describes how X-ray tube high voltage and electron beam current are stabilized. This paper also highlights generation of X-rays, diffractometry and X-ray fluorescence analysis and their wide applications. Principle of operation for stabilizing the X-ray tube voltage and current, different protection circuits adopted, special features of the mains H.V. transformer and H.T. tank are described in this report. (author)

  16. Cellular and molecular level responses after radiofrequency radiation exposure, alone or in combination with x-rays or chemicals. Final report, 1 April 1991-30 September 1994

    Energy Technology Data Exchange (ETDEWEB)

    Meltz, M.L.; Natarajan, M.; Prasad, A.V.

    1995-02-21

    This project was initiated to explore the potential bioeffects of microwave radiation, alone or in combination with ionizing radiation and chemicals. Over the time period of the project, an automated thermal control system, to be used for maintaining the temperature in tissue culture medium during microwave exposures, was designed, constructed, and software was created. While this was underway during the project period, numerous positive control biological experiments were performed on two different cell types, the Epstein Barr Virus transformed 244B human lymphoblastoid cell, and the freshly isolated peripheral human lymphocyte. The 244B cells were used to address the question of whether a physical agent, ionizing radiation, at low doses where cells would predominantly remain viable, would induce the DNA binding protein NF-kB, and/or four immediate early genes (IEG) (protooncogenes).

  17. Effect of x-rays on chromosome 21 nondisjunction

    International Nuclear Information System (INIS)

    In a series of 156 females and 149 males with a Down syndrome (DS) child, a case-control study was performed to evaluate the effect of abdominal-pelvic exposure to diagnostic x-rays prior to conception on nondisjunction (ND). Cytogenetic analysis using QFQ banding allowed unequivocal identification of ND parents as cases. Partners of ND parents were treated as control group. Odds ratio for the association of x-rays exposure and ND occurrence (stratified for sex and age) was 1.85 (borderline to significance: with a 95% confidence interval 1-3.44). Such an association appeared highly significant in older fathers and borderline to significant in younger mothers, when age groups were analyzed separately. By comparing mean parental ages at birth of the propositus, the prevalence of exposure to x-rays appeared moderately associated with aging in control parents of both sexes. Furthermore, the mean age of unexposed ND parents of paternally derived SD cases was the same as the referent population's, suggesting that age is not a risk factor for ND in the male, except for being associated with increasing exposure risk. Conversely, risk attributable to x-rays exposure in the female appears to be progressively diluted with increasing age, by strongly age-dependent high risk, presumably due to biologic factors that are not affected by environmental exposure

  18. Radiation safety and quality in diagnostic x-ray imaging 2001

    International Nuclear Information System (INIS)

    The obligations of the medical exposure directive (97/43/Euratom) for hospitals dominate the current activities in radiation protection in medical radiology. The directive gives special emphasis to radiation exposure of children, to examinations with high radiation doses and to radiation exposure in health screening programmes. The most important examinations with high doses are radiological interventions, where even acute skin effects are possible, and the computed tomography where the number of CT examinations makes only about 5% from the total number of x-ray examinations but the collective effective dose about 40% from the combined collective effective dose of all x-ray examinations. In the research projects financed by the European Commission, radiation exposures to paediatric patients have been measured in radiography, fluoroscopy and CT, and various dose assessment methods have been compared to develop a method for national follow-up of patients' radiation dose. The newest research project is focused on dosimetry and quality assurance in interventional radiology and digital imaging. Other actual topics are the development of radiation protection regulations and quality systems, education and training programmes, and clinical audits. This report deals with new radiation protection guides and recommendations and the education and training of radiological staff in radiation protection. One important topic is the development of national follow-up method of radiation exposure to patients and comparison of various dose assessment methods. Quality assurance in health care and in paediatric radiology, and the acceptance test and quality assurance measurements of radiological equipment are also described. (orig.)

  19. NuSTAR Hard X-ray Survey of the Galactic Center Region II: X-ray Point Sources

    CERN Document Server

    Hong, JaeSub; Hailey, Charles J; Nynka, Melania; Zhang, Shuo; Gotthelf, Eric; Fornasini, Francesca M; Krivonos, Roman; Bauer, Franz; Perez, Kerstin; Tomsick, John A; Bodaghee, Arash; Chiu, Jeng-Lun; Clavel, Maïca; Stern, Daniel; Grindlay, Jonathan E; Alexander, David M; Aramaki, Tsuguo; Baganoff, Frederick K; Barret, David; Barrière, Nicolas; Boggs, Steven E; Canipe, Alicia M; Christensen, Finn E; Craig, William W; Desai, Meera A; Forster, Karl; Giommi, Paolo; Grefenstette, Brian W; Harrison, Fiona A; Hong, Dooran; Hornstrup, Allan; Kitaguchi, Takao; Koglin, Jason E; Madsen, Kristen K; Mao, Peter H; Miyasaka, Hiromasa; Perri, Matteo; Pivovaroff, Michael J; Puccetti, Simonetta; Rana, Vikram; Westergaard, Niels J; Zhang, William W; Zoglauer, Andreas

    2016-01-01

    We present the first survey results of hard X-ray point sources in the Galactic Center (GC) region by NuSTAR. We have discovered 70 hard (3-79 keV) X-ray point sources in a 0.6 deg^2 region around Sgr A* with a total exposure of 1.7 Ms, and 7 sources in the Sgr B2 field with 300 ks. We identify clear Chandra counterparts for 58 NuSTAR sources and assign candidate counterparts for the remaining 19. The NuSTAR survey reaches X-ray luminosities of ~4 x and ~8 x 10^32 erg s^-1 at the GC (8 kpc) in the 3-10 and 10-40 keV bands, respectively. The source list includes three persistent luminous X-ray binaries and the likely run-away pulsar called the Cannonball. New source-detection significance maps reveal a cluster of hard (>10 keV) X-ray sources near the Sgr A diffuse complex with no clear soft X-ray counterparts. The severe extinction observed in the Chandra spectra indicates that all the NuSTAR sources are in the central bulge or are of extragalactic origin. Spectral analysis of relatively bright NuSTAR sources ...

  20. Phase-sensitive X-ray imager

    Science.gov (United States)

    Baker, Kevin Louis

    2013-01-08

    X-ray phase sensitive wave-front sensor techniques are detailed that are capable of measuring the entire two-dimensional x-ray electric field, both the amplitude and phase, with a single measurement. These Hartmann sensing and 2-D Shear interferometry wave-front sensors do not require a temporally coherent source and are therefore compatible with x-ray tubes and also with laser-produced or x-pinch x-ray sources.

  1. Optical element for X-ray microscopy

    OpenAIRE

    Chadzitaskos, G.

    2008-01-01

    We present a proposal for a X-ray optical element suitable for X-ray microscopy and other X-ray-based display systems. Its principle is based on the Fresnel lenses condition and the Bragg condition for X-ray scattering on a slice of monocrystal. These conditions are fulfilled simultaneously due to a properly machined shape of the monocrystal with a stress at its ends.

  2. Radiation-hygienic aspects of dental x-ray diagnosis

    International Nuclear Information System (INIS)

    The patients dose in taking dental x-rays is formed by exposure to both direct irradiation and scattered rays. The latter conditions accumulation of relatively large doses in some critical organs, such as thyroid gland, active bone marrow, including distant ones as gonads. Panoramic techniques issued in total dental status assessment reduce considerable radiation exposure of the patients, as compared to standard x-ray equipment (2 to 20 times). The panoramic technique accounts for minimum absorbed dose by adjacent organs and reduces external skin dose by 90 per cent. Practical implementation of digital x-ray machines in dentistry decreases the patient dose by 70-80 per cent, improves the image quality and enables image storage filing. Basic organisational, administrative and technical measures promoting patient dose reduction are suggested. (author)

  3. Cryotomography x-ray microscopy state

    Science.gov (United States)

    Le Gros, Mark; Larabell, Carolyn A.

    2010-10-26

    An x-ray microscope stage enables alignment of a sample about a rotation axis to enable three dimensional tomographic imaging of the sample using an x-ray microscope. A heat exchanger assembly provides cooled gas to a sample during x-ray microscopic imaging.

  4. Center for X-ray Optics, 1988

    International Nuclear Information System (INIS)

    This report briefly reviews the following topics: soft-x-ray imaging; reflective optics for hard x-rays; coherent XUV sources; spectroscopy with x-rays; detectors for coronary artery imaging; synchrotron-radiation optics; and support for the advanced light source

  5. Electron beam parallel X-ray generator

    Science.gov (United States)

    Payne, P.

    1967-01-01

    Broad X ray source produces a highly collimated beam of low energy X rays - a beam with 2 to 5 arc minutes of divergence at energies between 1 and 6 keV in less than 5 feet. The X ray beam is generated by electron bombardment of a target from a large area electron gun.

  6. X-Ray Exam: Neck (For Parents)

    Science.gov (United States)

    ... Tropical Delight: Melon Smoothie Pregnant? Your Baby's Growth X-Ray Exam: Neck KidsHealth > For Parents > X-Ray Exam: Neck Print A A A Text Size ... español Radiografía: cuello What It Is A neck X-ray is a safe and painless test that uses ...

  7. X-ray tracing using Geant4

    International Nuclear Information System (INIS)

    We describe an extension to the Geant4 software package that allows it to be used as a general purpose X-ray tracing package. We demonstrate the use of our extension by building a model of the X-ray optics of the X-ray observatory XMM-Newton, calculating its effective area, and comparing the results with the published calibration curves.

  8. X-RAY EMISSION FROM MAGNETIC MASSIVE STARS

    Energy Technology Data Exchange (ETDEWEB)

    Nazé, Yaël [GAPHE, Département AGO, Université de Liège, Allée du 6 Août 17, Bat. B5C, B-4000 Liège (Belgium); Petit, Véronique [Department of Physics and Space Sciences, Florida Institute of Technology, Melbourne, FL 32901 (United States); Rinbrand, Melanie; Owocki, Stan [Department of Physics and Astronomy, University of Delaware, Bartol Research Institute, Newark, DE 19716 (United States); Cohen, David [Department of Physics and Astronomy, Swarthmore College, Swarthmore, PA 19081 (United States); Ud-Doula, Asif [Penn State Worthington Scranton, Dunmore, PA 18512 (United States); Wade, Gregg A., E-mail: naze@astro.ulg.ac.be [Department of Physics, Royal Military College of Canada, PO Box 17000, Station Forces, Kingston, ON K7K 4B4 (Canada)

    2014-11-01

    Magnetically confined winds of early-type stars are expected to be sources of bright and hard X-rays. To clarify the systematics of the observed X-ray properties, we have analyzed a large series of Chandra and XMM-Newton observations, corresponding to all available exposures of known massive magnetic stars (over 100 exposures covering ∼60% of stars compiled in the catalog of Petit et al.). We show that the X-ray luminosity is strongly correlated with the stellar wind mass-loss rate, with a power-law form that is slightly steeper than linear for the majority of the less luminous, lower- M-dot B stars and flattens for the more luminous, higher- M-dot O stars. As the winds are radiatively driven, these scalings can be equivalently written as relations with the bolometric luminosity. The observed X-ray luminosities, and their trend with mass-loss rates, are well reproduced by new MHD models, although a few overluminous stars (mostly rapidly rotating objects) exist. No relation is found between other X-ray properties (plasma temperature, absorption) and stellar or magnetic parameters, contrary to expectations (e.g., higher temperature for stronger mass-loss rate). This suggests that the main driver for the plasma properties is different from the main determinant of the X-ray luminosity. Finally, variations of the X-ray hardnesses and luminosities, in phase with the stellar rotation period, are detected for some objects and they suggest that some temperature stratification exists in massive stars' magnetospheres.

  9. Review of quality of x-rays for templating for total hip arthroplasty.

    Science.gov (United States)

    Khan, Faiz; Ahmad, Tayyab; Condon, Finbarr; Lenehan, Brian

    2015-03-01

    Digital templating of x-rays for total hip arthroplasty is used routinely for pre-operative planning. This is to assure that appropriately sized implants are selected to replicate patient's hip biomechanics. Multiple studies have shown that templating does not always correspond to the final implants used. The aim of this study was to assess the suitability of the x-rays taken pre-operatively for templating for total hip arthroplasty. We undertook a review of a series of pre-operative templating pelvis x-rays in 100 consecutive patients undergoing total hip arthroplasty. These x-rays were compared against set criteria to determine their suitability for use for templating. We determined that six x-rays met the criteria whereas ninety four x-rays did not meet the criteria for suitable x-rays. Twenty patients had repeat x-rays. The reasons for unsuitability were inadequate opposite femur (66%), absence or incomplete template (54%), inadequate femur length (47%), external rotation (39%), absence of opposite hip (4%). The twenty repeated x-rays were also reviewed for the same parameters and two (10%) satisfied the established criteria. It is imperative that x-rays for templating for total hip arthroplasty are done to a strict standard to obtain an x-ray that is appropriate for templating and there is minimal exposure of the patient to irradiation.

  10. X-ray emission from magnetic massive stars

    CERN Document Server

    Naze, Yael; Rinbrand, Melanie; Cohen, David; Owocki, Stan; ud-Doula, Asif; Wade, Gregg A

    2014-01-01

    Magnetically confined winds of early-type stars are expected to be sources of bright and hard X-rays. To clarify the systematics of the observed X-ray properties, we have analyzed a large series of Chandra and XMM observations, corresponding to all available exposures of known massive magnetic stars (over 100 exposures covering ~60% of stars compiled in the catalog of Petit et al. 2013). We show that the X-ray luminosity is strongly correlated with the stellar wind mass-loss-rate, with a power-law form that is slightly steeper than linear for the majority of the less luminous, lower-Mdot B stars and flattens for the more luminous, higher-Mdot O stars. As the winds are radiatively driven, these scalings can be equivalently written as relations with the bolometric luminosity. The observed X-ray luminosities, and their trend with mass-loss rates, are well reproduced by new MHD models, although a few overluminous stars (mostly rapidly rotating objects) exist. No relation is found between other X-ray properties (p...

  11. Prenatal x-ray and childhood cancer in twins

    International Nuclear Information System (INIS)

    In order to evaluate the causal nature of the relationship between prenatal x-ray exposure and childhood cancer, a case control study was conducted in a population of over 32,000 twins born in the state of Connecticut from 1930-1969 and followed to age 15. Thirty-two incident cancer cases were identified by linking the Connecticut Twin and Tumor registries. Each case was matched with four controls on year of birth, sex, race, and survival. Prenatal x-ray information as well as reproductive, delivery and birth data were obtained from the hospital of birth, the physician providing prenatal care, private radiology groups and interviews with hospital staff. The case control study which obtained exposure information on selected subjects found an increased risk of childhood cancer from prenatal x-ray exposure. The risk associated with radiation exposure was elevated in the following subcategories: mother with history of pregnancy loss, a gravity greater than 1, under 30 years of age, and twins weighing five pounds or more at birth. The results, though based on small numbers, strengthen the association between prenatal x-ray exposure and childhood cancer

  12. Quality assurance in X-ray diagnostics

    International Nuclear Information System (INIS)

    For the purpose of establishing a reference system for quality assessments, the book presents and explains the quality criteria of importance to the X-ray diagnosis of the various body areas, and specifies the particular requirements to be met by the diagnostic technique in order to achieve optimum imaging. As the method of computerized tomography meanwhile is an accepted tool of X-ray diagnostics, the book also refers to this method in particular, stating the quality criteria and the technical requirements. It is dealt with as the tool allowing full utilization of all diagnostic means, with prevention of unnecessary exposure and cost being a high-priority objective. The book also discusses all particulars of the quality control of equipment, explaining various checking systems that in general are in line with the 3-stage concept published by the WHO, covering acceptance tests, in-service inspection, and consistency tests. Practical experience reports by five institutions are put together to present a useful survey of the technical characteristics to be tested, of the tolerance margins, testing methods, and evaluation of results, so that the parameters significance in practice is well explained. With 169 figs., 48 tabs

  13. 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)

    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

  14. Protonium X-ray spectroscopy

    CERN Document Server

    Gotta, D

    1999-01-01

    The Lyman and Balmer transitions from antiprotonic hydrogen and deuterium were studied extensively at the low-energy-antiproton ring LEAR at CERN in order to determine the strong interaction effects. A first series of experiments $9 was performed with semiconductor and gaseous X-ray detectors. In the last years of LEAR operation using a Bragg crystal spectrometer, strong interaction parameters in the 2p states of antiprotonic hydrogen and deuterium were measured $9 directly. The results of the measurements support the meson-exchange models describing the medium and long range part of the nucleon-antinucleon interaction. (39 refs).

  15. X-ray tomographic apparatus

    International Nuclear Information System (INIS)

    An x-ray tomographic system consists of a radiation source such as gamma or x radiation which produces a fan-shaped beam. The fan is wide enough to encompass the patient circle. The system further includes means for rotating the radiation source about the patient for less than a full rotation, and detectors for detecting the radiation at positions that surround the patient by 1800 plus the angle of the fan beam plus the angle between adjacent fan detectors. Attenuation data from the detectors is sorted into detector fans of attenuation data, then processed. The convolved data is back-projected into an image memory and displayed on a video monitor

  16. X-ray Pulsations in the Supersoft X-ray Binary CAL 83

    OpenAIRE

    Schmidtke, P. C.; Cowley, A. P.

    2005-01-01

    X-ray data reveal that the supersoft X-ray binary CAL 83 exhibits 38.4 minute pulsations at some epochs. These X-ray variations are similar to those found in some novae and are likely to be caused by nonradial pulsations the white dwarf. This is the first detection of pulsations in a classical supersoft X-ray binary.

  17. Ionospheric effects of solar x-rays

    Science.gov (United States)

    Danskin, Donald

    2016-07-01

    The ionospheric absorption of radio waves caused by solar x-ray bursts is measured directly by Riometers from the Canada Riometer Array. The absorption is found to be proportional to the square root of the flux intensity of the X-ray burst with time delays of 18-20 seconds between the peak X-ray emission and absorption in the ionosphere. A detailed analysis showed that some X-ray flares during 2011-2014 are more effective at producing absorption than others. Solar longitude of X-ray burst for several X-class flares shows no consistent pattern of enhancement in the absorption.

  18. Comets: mechanisms of x-ray activity

    Science.gov (United States)

    Ibadov, Subhon

    2016-07-01

    Basic mechanisms of X-ray activity of comets are considered, including D-D mechanism corresponding to generation of X-rays due to production of hot short-living plasma clumps at high-velocity collisions between cometary and interplanetary dust particles as well as M-M one corresponding to production of X-rays due to recombination of multicharge ions of solar wind plasma via charge exchange process at their collisions with molecules/atoms of the cometary atmospheres. Peculiarities of the variation of the comet X-ray spectrum and X-ray luminosity with variation of its heliocentric distance are revealed.

  19. Swift Observations of X-ray supernovae

    OpenAIRE

    Li, K. L.; Pun, Chun. S. J.

    2011-01-01

    We present a result of X-ray supernovae (SNe) survey using the Swift satellite public archive. An automatic searching program was designed to search X-ray SNe among all of the Swift archival observations between November 2004 and February 2011. Using the C++ program, 24 X-ray detectable supernovae have been found in the archive and 3 of them were newly-discovered in X-rays which are SN 1986L, SN 2003lx, and SN 2007od. In addition, SN 2003lx is a Type Ia supernova which may be the second X-ray...

  20. Symbiotic stars in X-rays

    OpenAIRE

    Luna, G. J. M.; Sokoloski, J. L.; Mukai, K; Nelson, T.

    2012-01-01

    Until recently, symbiotic binary systems in which a white dwarf accretes from a red giant were thought to be mainly a soft X-ray population. Here we describe the detection with the X-ray Telescope (XRT) on the Swift satellite of nine white dwarf symbiotics that were not previously known to be X-ray sources and one that had previously been detected as a supersoft X-ray source. The nine new X-ray detections were the result of a survey of 41 symbiotic stars, and they increase the number of symbi...

  1. In-Line Phase-Contrast Imaging Using Partially Coherent Hard X-Ray

    Institute of Scientific and Technical Information of China (English)

    喻虹; 朱频频; 韩申生; 罗震林; 高琛

    2003-01-01

    An experimental study of in-line hard x-ray phase-contrast imaging had been performed, using the polychromatic output of an x-ray tube. The results are in good agreement with partially coherent theory of hard x-ray phasecontrast imaging. The new technique provides the advantage to obtain the radiographs of large samples in an acceptable exposure time, which is very important to clinical applications.

  2. Full-field transmission x-ray imaging with confocal polycapillary x-ray optics

    OpenAIRE

    Sun, Tianxi; MacDonald, C. A.

    2013-01-01

    A transmission x-ray imaging setup based on a confocal combination of a polycapillary focusing x-ray optic followed by a polycapillary collimating x-ray optic was designed and demonstrated to have good resolution, better than the unmagnified pixel size and unlimited by the x-ray tube spot size. This imaging setup has potential application in x-ray imaging for small samples, for example, for histology specimens.

  3. X-Ray Protection Standards for Home Television Receivers.

    Science.gov (United States)

    National Council on Radiation Protection and Measurements, Washington, DC.

    Levels of X-Ray emission and exposure from home television receivers are being questioned and found greater than previous public health and safety cautions and measurement limits have suggested. The latest changes in television components, designs, function, and manufacturing, have caused equipment standards and the effects of radiation to be…

  4. Submicron hard X-ray fluorescence imaging of synthetic elements

    Energy Technology Data Exchange (ETDEWEB)

    Jensen, Mark P., E-mail: mjensen@anl.gov [Chemical Sciences and Engineering Division, Argonne National Laboratory, Argonne, IL 60439 (United States); Aryal, Baikuntha P. [Chemical Sciences and Engineering Division, Argonne National Laboratory, Argonne, IL 60439 (United States); Department of Chemistry, University of Chicago, Chicago, IL 60637 (United States); Gorman-Lewis, Drew [Chemical Sciences and Engineering Division, Argonne National Laboratory, Argonne, IL 60439 (United States); Paunesku, Tatjana [Department of Radiation Oncology, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611 (United States); Department of Radiology, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611 (United States); Lai, Barry; Vogt, Stefan [X-ray Science Division, Advanced Photon Source, Argonne National Laboratory, Argonne, IL 60439 (United States); Woloschak, Gayle E. [Department of Radiation Oncology, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611 (United States); Department of Radiology, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611 (United States)

    2012-04-13

    Highlights: Black-Right-Pointing-Pointer Actinide elements are mapped with L-edge X-rays and better than 400 nm resolution. Black-Right-Pointing-Pointer A typical detection limit was 2.9 Multiplication-Sign 10{sup -20} moles Pu {mu}m{sup -2}. Black-Right-Pointing-Pointer XANES measurements provide chemical information in 0.1 {mu}m{sup 2} spots. Black-Right-Pointing-Pointer Selection of materials for encapsulation is important for avoiding interferences. - Abstract: Synchrotron-based X-ray fluorescence microscopy (XFM) using hard X-rays focused into sub-micron spots is a powerful technique for elemental quantification and mapping, as well as microspectroscopic measurements such as {mu}-XANES (X-ray absorption near edge structure). We have used XFM to image and simultaneously quantify the transuranic element plutonium at the L{sub 3} or L{sub 2}-edge as well as Th and lighter biologically essential elements in individual rat pheochromocytoma (PC12) cells after exposure to the long-lived plutonium isotope {sup 242}Pu. Elemental maps demonstrate that plutonium localizes principally in the cytoplasm of the cells and avoids the cell nucleus, which is marked by the highest concentrations of phosphorus and zinc, under the conditions of our experiments. The minimum detection limit under typical acquisition conditions with an incident X-ray energy of 18 keV for an average 202 {mu}m{sup 2} cell is 1.4 fg Pu or 2.9 Multiplication-Sign 10{sup -20} moles Pu {mu}m{sup -2}, which is similar to the detection limit of K-edge XFM of transition metals at 10 keV. Copper electron microscopy grids were used to avoid interference from gold X-ray emissions, but traces of strontium present in naturally occurring calcium can still interfere with plutonium detection using its L{sub {alpha}} X-ray emission.

  5. Pulmonary complications of induction therapy for acute myeloid leukemia in adults. Findings of chest X-rays and computed tomography; Pulmonale Komplikationen der Induktionstherapie bei akuter myeloischer Leukaemie des Erwachsenen. Befunde in Thoraxuebersichtsaufnahme und Computertomographie

    Energy Technology Data Exchange (ETDEWEB)

    Kirchner, J.; Huettmann, C.; Jacobi, V. [Univ. Frankfurt am Main (Germany). Inst. fuer Roentgendiagnostik; Boehme, A. [Frankfurt Univ. (Germany). Medizinische Klinik 3

    1998-03-01

    To exclude pulmonary complications, 359 chest radiographs and 50 computed tomographs of the lung were performed in 95 patients suffering from acute myeloid leukemia. The radiological findings were registered, described and correlated with clinical findings in the present study on 2395 days of observation. Results: In summary, 52 patients showed alterations of the lung. Pulmonary hyperhydration was seen in 21 cases, bacterial pneumonia was found in 18 cases, invasive pulmonary aspergillosis was documented in 14 cases, and 5 cases of severe haemorrhage were seen. An unexplained pulmonary edema in 13 patients with interstitial and alveolar infiltrates is considered to be a complication of treatment with cytosine-arabinoside. Conclusion: The results demonstrate that chest X-ray and computed tomography have a high impact in detection and treatment of pulmonary complications following intensive chemotherapy. We may expect the development of diffuse opacity following administration of cytosine-arabinoside in medium-sized doses. (orig.) [Deutsch] Zum Ausschluss pulmonaler Komplikationen durchgefuehrte Thoraxuebersichtsaufnahmen (n=359) und computertomographische Untersuchungen der Lunge (n=50) von 95 Patienten mit akuter myeloischer Leukaemie werden in der vorliegenden Arbeit systematisch erfasst, beschrieben und mit den klinischen Symptomen an insgesamt 2395 Beobachtungstagen korreliert. Ergebnisse: Hierbei wiesen 52 Patienten Lungenveraenderungen auf. Eine pulmonale Ueberwaesserung wurde in 21 Faellen beobachtet, bakterielle Pneumonien in 18 Faellen, eine invasive pulmonale Aspergillose in 14 Faellen. Es wurden 5 Lungenblutungen beobachtet. Ein bei 13 Patienten aufgetretenes unklares Lungenoedem mit diffuser interstitieller Zeichnungsvermehrung und auch alveolaerer Komponente wird von uns als Komplikation der Anwendung von Cytosin-Arabinosid angenommen. Schlussfolgerung: Thoraxuebersichtsaufnahme und Computertomographie besitzen einen hohen Stellenwert bei der Erkennung

  6. The research of biological effects induced by C-arm X ray acute scan%C形臂X光机急性扫描诱导的生物效应研究

    Institute of Scientific and Technical Information of China (English)

    杨博; 高宇巍; 杨澄; 李宏伟

    2014-01-01

    Objective To investigate the biological effects induced by C-arm X ray acute scan in mice.Methods 60 healthy male BALB/c mice were randomly divided into control group,single,four,eight and twelve times of C-arm X ray scan; there were 12 mice in each group.The mice were administered with different frequency of whole-body C-arm X ray scan; After 24 h of scan,malondialdehyde (MDA) and superoxide dismutase(SOD) were detected;Enzyme Linked Immuno Sorbent Assay (ELISA) was used to detect the level of IL-4 and IFN-γin serum.The apoptosis level of peripheral lymphocytes and bone marrow cells was analyzed by flow cytometry.Results Compared with control,more than eight times of scan increased MDA level by 2.39 and 3.49,but more than four times of scan decreased SOD level in thyroid by 19.23%,25.80% and 27.95%.More than four times of scan decreased the level of IFN-γ and IL-4 in the serum by 14.71% and 22.60%,22.99% and 44.05%,31.70% and 44.43%,but no influence on the ratio of IFN-γ/IL-4 was observed.More than eight and twelve times of scan increased apoptosis level in peripheral lymphocytes and bone marrow cells by 1.68,2.40 and 2.02.Conclusion Whith Multiple scan C-arm X ray changed oxidative level and immunological response.In addition,apoptosis was initiated to maintain genome stability.%目的 探讨研究C形臂X光机急性扫描对小鼠机体功能的影响.方法 健康雄性BALB/c小鼠60只随机分为对照组、单次、四次、八次和十二次扫描组,每组12只.对照组小鼠不扫描,其余组用C形臂X光机对小鼠进行全身扫描.在照射后24小时,采用生物化学方法检测小鼠甲状腺组织中超氧化物歧化酶(SOD)和丙二醛(MDA)的水平;采用酶联免疫吸附试验(ELISA)检测血清中IL-4和IFN-γ的变化;流式细胞仪检测各照射组小鼠外周血淋巴细胞和骨髓细胞的凋亡水平.结果 与对照组比较,小鼠甲状腺组织中的MDA水平在八次以上扫描后分别升高了2.39、3

  7. X-ray Multimodal Tomography Using Speckle-Vector Tracking

    Science.gov (United States)

    Berujon, Sebastien; Ziegler, Eric

    2016-04-01

    We demonstrate computerized tomography (CT) reconstructions from absorption, phase, and dark-field signals obtained from scans acquired when the x-ray probe light is modulated with speckle. Two different interlaced schemes are proposed to reduce the number of sample exposures. First, the already demonstrated x-ray speckle-vector tracking (XSVT) concept for projection imaging allows the three signal CT reconstructions from multiple images per projection. Second, a modified XSVT approach is shown to provide absorption and phase reconstructions, this time from a single image per angular projection. Reconstructions from data obtained at a synchrotron facility emphasize the potential of the approaches for the imaging of complex samples.

  8. Dental X-ray equipment inspection program in Manitoba

    International Nuclear Information System (INIS)

    The dental X-ray equipment inspection program that has been in effect in Manitoba for all units since 1973 is described and the development of the survey procedure followed throughout 1978. The workloads associated with the dental units for both urban and rural facilities are presented and discussed. Data indicating the type and frequency of faults found as well as the dental X-ray exposure for the maxillary molar procedure in kVp ranges from 45 to 95 are also presented along with the corresponding dental film optical densities as obtained with one of the survey procedures. (author)

  9. Routine dental x-ray : a health hazards

    International Nuclear Information System (INIS)

    In orthopantography (OPG) technique, a single panoramic x-ray replaces a dozen or so conventional x-ray exposures required for a full-mouth examination. OPG, thus, reduces radiation dose to the patients. However, the very simplicity of the OPG technique may lead to its misuse. The dentists are tempted to take too many OPG films and thus exposing the patients unnecessarily to X radiation. Dentists are advised against making dental x-radiography a routine part of examinations. Greater care should be exercised particularly in the case of children while using OPG. (M.G.B.)

  10. Determination of tube voltage in X-ray equipment

    International Nuclear Information System (INIS)

    Next to filtration, tube voltage or tube potential difference is one of the most significant parameters for the quality of X-rays, especially with a view to its absolute value, its variation during exposure and its long-term constancy. Voltage control is major component pf quality assurance in diagnostic radiography. Various non-invasive methods are available for voltage measurements. The article reports the experience gained with the kV-indicating cassette, the X-ray analyses (NERO system) and the multi-channel analyser. (orig./HP)

  11. X-Ray Emission from M32: X-Ray Binaries or a micro-AGN?

    OpenAIRE

    Eskridge, Paul B.; White III, Raymond E.; Davis, David S.

    1996-01-01

    We have analysed archival {\\it ROSAT} PSPC data for M32 in order to study the x-ray emission from this nearest elliptical galaxy. We fit spectra from three long exposures with Raymond-Smith, thermal bremsstrahlung, and power-law models. All models give excellent fits. The thermal fits have kT$\\approx$4 keV, the Raymond-Smith iron abundance is $0.4^{+0.7}_{-0.3}$ Solar, the power-law fit has $\\alpha$=1.6$\\pm$0.1, and all fits have $N_H$ consistent with the Galactic column. The source is center...

  12. Occupational exposure in X ray diagnosis

    International Nuclear Information System (INIS)

    Evaluation of the results of routine personnel monitoring and extra routine field measurements revealed that occupational whole-body doses, as determined by means of the routine personnel dosemeter, are normally very low, while partial body doses, especially doses to the hands and fingers may reach dose limits. This indicates the need for suitable monitoring of partial body doses. (author)

  13. Elemental x-ray imaging using Zernike phase contrast

    Science.gov (United States)

    Shao, Qi-Gang; Chen, Jian; Wali, Faiz; Bao, Yuan; Wang, Zhi-Li; Zhu, Pei-Ping; Tian, Yang-Chao; Gao, Kun

    2016-10-01

    We develop an element-specific x-ray microscopy method by using Zernike phase contrast imaging near absorption edges, where a real part of refractive index changes abruptly. In this method two phase contrast images are subtracted to obtain the target element: one is at the absorption edge of the target element and the other is near the absorption edge. The x-ray exposure required by this method is expected to be significantly lower than that of conventional absorption-based x-ray elemental imaging methods. Numerical calculations confirm the advantages of this highly efficient imaging method. Project supported by the National Basic Research Program of China (Grant No. 2012CB825801) and the National Natural Science Foundation of China (Grant Nos. 11505188, and 11305173).

  14. X-ray diffraction microtomography using synchrotron radiation

    CERN Document Server

    Barroso, R C; Jesus, E F O; Oliveira, L F

    2001-01-01

    The X-ray diffraction computed tomography technique is based on the interference phenomena of the coherent scatter. For low-momentum transfer, it is most probable that the scattering interaction will be coherent. A selective discrimination of a given element in a scanned specimen can be realized by fixing the Bragg angle which produces an interference peak and then, to carry out the computed tomography in the standard mode. The image reconstructed exalts the presence of this element with respect to other ones in a sample. This work reports the feasibility of a non-destructive synchrotron radiation X-ray diffraction imaging technique. This research was performed at the X-ray Diffraction beam line of the National Synchrotron Light Laboratory (LNLS) in Brazil. The coherent scattering properties of different tissue and bone substitute materials were evaluated. Furthermore, diffraction patterns of some polycrystalline solids were studied due to industrial and environmental human exposure to these metals. The obtai...

  15. The Advanced X-ray Astrophysics Facility high resolution camera

    Science.gov (United States)

    Murray, Stephen S.; Chappell, Jon H.

    1986-01-01

    The HRC (High Resolution Camera) is a photon counting instrument to be flown on the Advanced X-Ray Astrophysics Facility (AXAF). It is a large field of view, high angular resolution, detector for the X-ray telescope. The HRC consists of a CsI coated microchannel plate (MCP) acting as a soft X-ray photocathode, followed by a second MCP for high electronic gain. The MCPs are readout by a crossed grid of resistively coupled wires to provide high spatial resolution along with timing and pulse height data. The instrument will be used in two modes, as a direct imaging detector with a limiting sensitivity of 10 to the -15th ergs/sq cm sec in a 10 to the 5th second exposure, and as a readout for an objective transmission grating providing spectral resolution of several hundreds to thousands.

  16. Enhancement of X-ray dose absorption for medical applications

    Science.gov (United States)

    Lim, Sara; Montenegro, Maximiliano; Nahar, Sultana; Pradhan, Anil; Barth, Rolf; Nakkula, Robin; Bell, Erica; Yu, Yan

    2012-06-01

    Interaction of high-Z (HZ) elements with X-rays occurs efficiently at specific resonant energies. Cross sections for photoionization rapidly decrease after the K-edge; higher energy X-rays are mostly Compton-scattered. These features restrict the energy range for the use of HZ moities for radiosensitization in cancer therapy. Conventional X-ray sources such as linear accelerators (LINAC) used in radiotherapy emit a broad spectrum up to MeV energies. We explore the dichotomy between X-ray radiotherapy in two ranges: (i) E 100 keV where sensitization is inefficient. We perform Monte Carlo numerical simulations of tumor tissue embedded with platinum compounds and gold nanoparticles and compute radiation dose enhancement factors (DEF) upon irradiation with 100 kV, 170 kV and 6 MV sources. Our results demonstrate that the DEF peak below 100 keV and fall sharply above 200 keV to very small values. Therefore most of the X-ray output from LINACs up to the MeV range is utilized very inefficiently. We also describe experimental studies for implementation of option (i) using Pt and Au reagents and selected cancer cell lines. Resultant radiation exposure to patients could be greatly reduced, yet still result in increased tumoricidal ability.

  17. Method and apparatus for micromachining using hard X-rays

    Science.gov (United States)

    Siddons, David Peter; Johnson, Erik D.; Guckel, Henry; Klein, Jonathan L.

    1997-10-21

    An X-ray source such as a synchrotron which provides a significant spectral content of hard X-rays is used to expose relatively thick photoresist such that the portions of the photoresist at an exit surface receive at least a threshold dose sufficient to render the photoresist susceptible to a developer, while the entrance surface of the photoresist receives an exposure which does not exceed a power limit at which destructive disruption of the photoresist would occur. The X-ray beam is spectrally shaped to substantially eliminate lower energy photons while allowing a substantial flux of higher energy photons to pass through to the photoresist target. Filters and the substrate of the X-ray mask may be used to spectrally shape the X-ray beam. Machining of photoresists such as polymethylmethacrylate to micron tolerances may be obtained to depths of several centimeters, and multiple targets may be exposed simultaneously. The photoresist target may be rotated and/or translated in the beam to form solids of rotation and other complex three-dimensional structures.

  18. X-Ray Attenuation Cell

    Energy Technology Data Exchange (ETDEWEB)

    Ryutov, D.; Toor, A.

    2000-03-03

    To minimize the pulse-to-pulse variation, the LCLS FEL must operate at saturation, i.e. 10 orders of magnitude brighter spectral brilliance than 3rd-generation light sources. At this intensity, ultra-high vacuums and windowless transport are required. Many of the experiments, however, will need to be conducted at a much lower intensity thereby requiring a reliable means to reduce the x-ray intensity by many orders of magnitude without increasing the pulse-to-pulse variation. In this report we consider a possible solution for controlled attenuation of the LCLS x-ray radiation. We suggest using for this purpose a windowless gas-filled cell with the differential pumping. Although this scheme is easily realizable in principle, it has to be demonstrated that the attenuator can be made short enough to be practical and that the gas loads delivered to the vacuum line of sight (LOS) are acceptable. We are not going to present a final, optimized design. Instead, we will provide a preliminary analysis showing that the whole concept is robust and is worth further study. The spatial structure of the LCLS x-ray pulse at the location of the attenuator is shown in Fig. 1. The central high-intensity component, due to the FEL, has a FWHM of {approx}100 {micro}m. A second component, due to the undulator's broad band spontaneous radiation is seen as a much lower intensity ''halo'' with a FWHM of 1 mm. We discuss two versions of the attenuation cell. The first is directed towards a controlled attenuation of the FEL up to the 4 orders of magnitude in the intensity, with the spontaneous radiation halo being eliminated by collimators. In the second version, the spontaneous radiation is not sacrificed but the FEL component (as well as the first harmonic of the spontaneous radiation) gets attenuated by a more modest factor up to 100. We will make all the estimates assuming that the gas used in the attenuator is Xenon and that the energy of the FEL is 8.25 keV. At

  19. Acute radiation enteritis caused by dose-dependent radiation exposure in dogs: experimental research.

    Science.gov (United States)

    Xu, Wenda; Chen, Jiang; Xu, Liu; Li, Hongyu; Guo, Xiaozhong

    2014-12-01

    Accidental or intended radiation exposure in mass casualty settings presents a serious and on-going threat. The development of mitigating and treating agents requires appropriate animal models. Unfortunately, the majority of research on radiation enteritis in animals has lacked specific assessments and targeted therapy. Our study showed beagle dogs, treated by intensity-modulated radiation therapy (IMRT) for abdominal irradiation, were administered single X-ray doses of 8-30 Gy. The degree of intestinal tract injury for all of the animals after radiation exposure was evaluated with regard to clinical syndrome, endoscopic findings, histological features, and intestinal function. The range of single doses (8 Gy, 10-14 Gy, and 16-30 Gy) represented the degree of injury (mild, moderate, and severe, respectively). Acute radiation enteritis included clinical syndrome with fever, vomiting, diarrhea, hemafecia, and weight loss; typical endoscopic findings included edema, bleeding, mucosal abrasions, and ulcers; and intestinal biopsy results revealed mucosal necrosis, erosion, and loss, inflammatory cell infiltration, hemorrhage, and congestion. Changes in serum diamine oxides (DAOs) and d-xylose represented intestinal barrier function and absorption function, respectively, and correlated with the extent of damage (P enteritis, thus obtaining a relatively objective evaluation of intestinal tract injury based on clinical performance and laboratory examination. The method of assessment of the degree of intestinal tract injury after abdominal irradiation could be beneficial in the development of novel and effective therapeutic strategies for acute radiation enteritis.

  20. Modification of the TASMIP x-ray spectral model for the simulation of microfocus x-ray sources

    Energy Technology Data Exchange (ETDEWEB)

    Sisniega, A.; Vaquero, J. J., E-mail: juanjose.vaquero@uc3m.es [Departamento de Bioingeniería e Ingeniería Aeroespacial, Universidad Carlos III de Madrid, Madrid ES28911 (Spain); Instituto de Investigación Sanitaria Gregorio Marañón, Madrid ES28007 (Spain); Desco, M. [Departamento de Bioingeniería e Ingeniería Aeroespacial, Universidad Carlos III de Madrid, Madrid ES28911 (Spain); Instituto de Investigación Sanitaria Gregorio Marañón, Madrid ES28007 (Spain); Centro de Investigación Biomédica en Red de Salud Mental (CIBERSAM), Madrid ES28029 (Spain)

    2014-01-15

    Purpose: The availability of accurate and simple models for the estimation of x-ray spectra is of great importance for system simulation, optimization, or inclusion of photon energy information into data processing. There is a variety of publicly available tools for estimation of x-ray spectra in radiology and mammography. However, most of these models cannot be used directly for modeling microfocus x-ray sources due to differences in inherent filtration, energy range and/or anode material. For this reason the authors propose in this work a new model for the simulation of microfocus spectra based on existing models for mammography and radiology, modified to compensate for the effects of inherent filtration and energy range. Methods: The authors used the radiology and mammography versions of an existing empirical model [tungsten anode spectral model interpolating polynomials (TASMIP)] as the basis of the microfocus model. First, the authors estimated the inherent filtration included in the radiology model by comparing the shape of the spectra with spectra from the mammography model. Afterwards, the authors built a unified spectra dataset by combining both models and, finally, they estimated the parameters of the new version of TASMIP for microfocus sources by calibrating against experimental exposure data from a microfocus x-ray source. The model was validated by comparing estimated and experimental exposure and attenuation data for different attenuating materials and x-ray beam peak energy values, using two different x-ray tubes. Results: Inherent filtration for the radiology spectra from TASMIP was found to be equivalent to 1.68 mm Al, as compared to spectra obtained from the mammography model. To match the experimentally measured exposure data the combined dataset required to apply a negative filtration of about 0.21 mm Al and an anode roughness of 0.003 mm W. The validation of the model against real acquired data showed errors in exposure and attenuation in

  1. X-ray intensifying screens

    International Nuclear Information System (INIS)

    An x-ray intensifying screen comprises a support which has a luminescent composition comprising an isotropic phosphor and a polymer having an index of refraction within 0.02 of that of the phosphor over at least 80 percent of its emission spectrum. The support has an index of refraction up to or equal to 0.05 units higher than that of the phosphor and has a reflection optical density of at least 1.7 to light emitted by the phosphor. A preferred luminescent composition comprises Kl:Tl, Rbl:Tl at BaSrFCl:Eu mixed with two monomers such as 1-naphthylmethylmethacrylate, S(1-naphthylmethyl) thioacrylate, 1-bromo-2-naphthylacrylate, and benzyl methacrylate, coated on black anodised Al and polymerised in situ. The ratio of monomers is adjusted to give the desired refractive index. Other phosphors, polymers and supports are specified together with the preparation of the monomers and polymers. (author)

  2. Cancer among medical diagnostic x-ray workers in China

    Energy Technology Data Exchange (ETDEWEB)

    Wang, J.X.; Boice, J.D. Jr.; Li, B.X.; Zhang, J.Y.; Fraumeni, J.F. Jr.

    1988-05-04

    Cancer incidence among 27,011 diagnostic x-ray workers was compared to that of 25,782 other medical specialists employed between 1950 and 1980 in China. X-ray workers had a 50% higher risk of developing cancer than the other specialists (relative risk (RR) = 1.5; 95% CI = 1.3-1.7). Leukemia was strongly linked to radiation work (RR = 3.5, n = 30). Cancers of the breast (RR = 1.4, n = 11), thyroid (RR = 2.1, n = 7), and skin (RR = 1.5, n = 6) were increased among x-ray workers employed for 10 or more years. High risks of cancers of the esophagus (RR = 3.5, n = 15) and liver (RR = 2.4, n = 48) were not consistent with a radiation effect since risk did not vary by duration of employment. This finding suggested that some differences might exist between groups of hospital workers in social class, alcohol intake, dietary habits, and other risk factors. No excess lung cancer (RR = 0.9, n = 22) or multiple myeloma (n = 0) was observed. Significant excesses of leukemia and cancers of the breast and thyroid occurred among x-ray workers first employed prior to 1960 when radiation exposures in China were high. In fact, it was not uncommon for employees to be given time off from x-ray work because their wbc count was severely depressed. These data indicated that repeated exposure to x-rays over many years can increase the risk of leukemia and several other tumors but apparently not that of lung cancer.

  3. The trickle before the torrent-diffraction data from X-ray lasers.

    Science.gov (United States)

    Maia, Filipe R N C; Hajdu, Janos

    2016-08-01

    Today Scientific Data launched a collection of publications describing data from X-ray free-electron lasers under the theme 'Structural Biology Applications of X-ray Lasers'. The papers cover data on nanocrystals, single virus particles, isolated cell organelles, and living cells. All data are deposited with the Coherent X-ray Imaging Data Bank (CXIDB) and available to the scientific community to develop ideas, tools and procedures to meet challenges with the expected torrents of data from new X-ray lasers, capable of producing billion exposures per day.

  4. Hard X-ray irradiation of cosmic silicate analogs: structural evolution and astrophysical implications

    Science.gov (United States)

    Gavilan, L.; Jäger, C.; Simionovici, A.; Lemaire, J. L.; Sabri, T.; Foy, E.; Yagoubi, S.; Henning, T.; Salomon, D.; Martinez-Criado, G.

    2016-03-01

    Context. Protoplanetary disks, interstellar clouds, and active galactic nuclei contain X-ray-dominated regions. X-rays interact with the dust and gas present in such environments. While a few laboratory X-ray irradiation experiments have been performed on ices, X-ray irradiation experiments on bare cosmic dust analogs have been scarce up to now. Aims: Our goal is to study the effects of hard X-rays on cosmic dust analogs via in situ X-ray diffraction. By using a hard X-ray synchrotron nanobeam, we seek to simulate cumulative X-ray exposure on dust grains during their lifetime in these astrophysical environments and provide an upper limit on the effect of hard X-rays on dust grain structure. Methods: We prepared enstatite (MgSiO3) nanograins, which are analogs to cosmic silicates, via the melting-quenching technique. These amorphous grains were then annealed to obtain polycrystalline grains. These were characterized via scanning electron microscopy (SEM) and high-resolution transmission electron microscopy (HRTEM) before irradiation. Powder samples were prepared in X-ray transparent substrates and were irradiated with hard X-rays nanobeams (29.4 keV) provided by beamline ID16B of the European Synchrotron Radiation Facility (Grenoble). X-ray diffraction images were recorded in transmission mode, and the ensuing diffractograms were analyzed as a function of the total X-ray exposure time. Results: We detected the amorphization of polycrystalline silicates embedded in an organic matrix after an accumulated X-ray exposure of 6.4 × 1027 eV cm-2. Pure crystalline silicate grains (without resin) do not exhibit amorphization. None of the amorphous silicate samples (pure and embedded in resin) underwent crystallization. We analyze the evolution of the polycrystalline sample embedded in an organic matrix as a function of X-ray exposure. Conclusions: Loss of diffraction peak intensity, peak broadening, and the disappearance of discrete spots and arcs reveal the amorphization

  5. The trickle before the torrent—diffraction data from X-ray lasers

    Science.gov (United States)

    Maia, Filipe R.N.C.; Hajdu, Janos

    2016-01-01

    Today Scientific Data launched a collection of publications describing data from X-ray free-electron lasers under the theme ‘Structural Biology Applications of X-ray Lasers’. The papers cover data on nanocrystals, single virus particles, isolated cell organelles, and living cells. All data are deposited with the Coherent X-ray Imaging Data Bank (CXIDB) and available to the scientific community to develop ideas, tools and procedures to meet challenges with the expected torrents of data from new X-ray lasers, capable of producing billion exposures per day. PMID:27479637

  6. The trickle before the torrent-diffraction data from X-ray lasers.

    Science.gov (United States)

    Maia, Filipe R N C; Hajdu, Janos

    2016-01-01

    Today Scientific Data launched a collection of publications describing data from X-ray free-electron lasers under the theme 'Structural Biology Applications of X-ray Lasers'. The papers cover data on nanocrystals, single virus particles, isolated cell organelles, and living cells. All data are deposited with the Coherent X-ray Imaging Data Bank (CXIDB) and available to the scientific community to develop ideas, tools and procedures to meet challenges with the expected torrents of data from new X-ray lasers, capable of producing billion exposures per day. PMID:27479637

  7. Soft x-ray interferometry

    International Nuclear Information System (INIS)

    The purpose of the soft x-ray interferometry workshop held at Lawrence Berkeley Laboratory was to discuss with the scientific community the proposed technical design of the soft x-ray Fourier-transform spectrometer being developed at the ALS. Different design strategies for the instrument's components were discussed, as well as detection methods, signal processing issues, and how to meet the manufacturing tolerances that are necessary for the instrument to achieve the desired levels of performance. Workshop participants were encouraged to report on their experiences in the field of Fourier transform spectroscopy. The ALS is developing a Fourier transform spectrometer that is intended to operate up to 100 eV. The motivation is solely improved resolution and not the throughput (Jaquinot) or multiplex (Fellgett) advantage, neither of which apply for the sources and detectors used in this spectral range. The proposed implementation of this is via a Mach-Zehnder geometry that has been (1) distorted from a square to a rhombus to get grazing incidence of a suitable angle for 100 eV and (2) provided with a mirror-motion system to make the path difference between the interfering beams tunable. The experiment consists of measuring the emergent light intensity (I(x)) as a function of the path difference (x). The resolving power of the system is limited by the amount of path difference obtainable that is 1 cm (one million half-waves at 200 angstrom wavelength) in the design thus allowing a resolving power of one million. The free spectral range of the system is limited by the closeness with which the function I(x) is sampled. It is proposed to illuminate a helium absorption cell with roughly 1%-band-width light from a monochromator thus allowing one hundred aliases without spectral overlap even for sampling of I(x) at one hundredth of the Nyquist frequency

  8. Soft x-ray polarimeter laboratory tests

    Science.gov (United States)

    Murphy, Kendrah D.; Marshall, Herman L.; Schulz, Norbert S.; Jenks, Kevin; Sommer, Sophie J. B.; Marshall, Eric A.

    2010-07-01

    Multilayer-coated optics can strongly polarize X-rays and are central to a new design of a broad-band, soft X-ray polarimeter. We have begun laboratory work to verify the performance of components that could be used in future soft X-ray polarimetric instrumentation. We have reconfigured a 17 meter beamline facility, originally developed for testing transmission gratings for Chandra, to include a polarized X-ray source, an X-ray-dispersing transmission grating, and a multilayer-coated optic that illuminates a CCD detector. The X-rays produced from a Manson Model 5, multi-anode source are polarized by a multilayer-coated flat mirror. The current configuration allows for a 180 degree rotation of the source in order to rotate the direction of polarization. We will present progress in source characterization and system modulation measurements as well as null and robustness tests.

  9. X-rays for medical use

    Science.gov (United States)

    Hessenbruch, A.

    1995-11-01

    1995 is the centenary of the discovery of X-rays by the German physicist Wilhelm C Rontgen. In the past hundred years, the new rays have developed from being unknown to finding application in many walks of life, not least in medicine. This is so much so that in common speech the word `x-ray` refers not to a form of radiation but to an X-ray photograph taken for the purposes of diagnosis (as in: `I had an X-ray done to see if my leg was broken`). X-rays are now used routinely, and they are used both for diagnosis and for therapy. This paper will give an outline of the use of X-rays in medicine throughout our present century.

  10. Handbook of X-Ray Data

    CERN Document Server

    Zschornack, Günter

    2007-01-01

    This sourcebook is intended as an X-ray data reference for scientists and engineers working in the field of energy or wavelength dispersive X-ray spectrometry and related fields of basic and applied research, technology, or process and quality controlling. In a concise and informative manner, the most important data connected with the emission of characteristic X-ray lines are tabulated for all elements up to Z = 95 (Americium). This includes X-ray energies, emission rates and widths as well as level characteristics such as binding energies, fluorescence yields, level widths and absorption edges. The tabulated data are characterized and, in most cases, evaluated. Furthermore, all important processes and phenomena connected with the production, emission and detection of characteristic X-rays are discussed. This reference book addresses all researchers and practitioners working with X-ray radiation and fills a gap in the available literature.

  11. Laboratory soft x-ray microscopy and tomography

    International Nuclear Information System (INIS)

    Soft x-ray microscopy in the water-window (λ = 2.28 nm - 4.36 nm) is based on zone-plate optics and allows high-resolution imaging of, e.g., cells and soils in their natural or near-natural environment. Three-dimensional imaging is provided via tomographic techniques, soft x-ray cryo tomography. However, soft x-ray microscopes with such capabilities have been based on large-scale synchrotron x-ray facilities, thereby limiting their accessibility for a wider scientific community. This Thesis describes the development of the Stockholm laboratory soft x-ray microscope to three-dimensional cryo tomography and to new optics-based contrast mechanisms. The microscope relies on a methanol or nitrogen liquid-jet laser-plasma source, normal-incidence multilayer or zone-plate condenser optics, in-house fabricated zone-plate objectives, and allows operation at two wavelengths in the water-window, λ = 2.48 nm and λ = 2.48 nm. With the implementation of a new state-of-the-art normal-incidence multilayer condenser for operation at λ = 2.48 nm and a tiltable cryogenic sample stage the microscope now allows imaging of dry, wet or cryo-fixed samples. This arrangement was used for the first demonstration of laboratory soft x-ray cryo microscopy and tomography. The performance of the microscope has been demonstrated in a number of experiments described in this Thesis, including, tomographic imaging with a resolution of 140 nm, cryo microscopy and tomography of various cells and parasites, and for studies of aqueous soils and clays. The Thesis also describes the development and implementation of single-element differential-interference and Zernike phase-contrast zone-plate objectives. The enhanced contrast provided by these optics reduce exposure times or lowers the dose in samples and are of major importance for harder x-ray microscopy. The implementation of a high-resolution 50 nm compound zone-plate objective for sub-25-nm resolution imaging is also described. All experiments

  12. X-ray microlaminography with polycapillary optics

    Energy Technology Data Exchange (ETDEWEB)

    Dabrowski, K. M.; Dul, D. T.; Wrobel, A.; Korecki, P. [Institute of Physics, Jagiellonian University, Reymonta 4, 30-059 Krakow (Poland)

    2013-06-03

    We demonstrate layer-by-layer x-ray microimaging using polycapillary optics. The depth resolution is achieved without sample or source rotation and in a way similar to classical tomography or laminography. The method takes advantage from large angular apertures of polycapillary optics and from their specific microstructure, which is treated as a coded aperture. The imaging geometry is compatible with polychromatic x-ray sources and with scanning and confocal x-ray fluorescence setups.

  13. X-ray data booklet. Revision

    Energy Technology Data Exchange (ETDEWEB)

    Vaughan, D. (ed.)

    1986-04-01

    A compilation of data is presented. Included are properties of the elements, electron binding energies, characteristic x-ray energies, fluorescence yields for K and L shells, Auger energies, energy levels for hydrogen-, helium-, and neonlike ions, scattering factors and mass absorption coefficients, and transmission bands of selected filters. Also included are selected reprints on scattering processes, x-ray sources, optics, x-ray detectors, and synchrotron radiation facilities. (WRF)

  14. Applications of soft x-ray lasers

    Energy Technology Data Exchange (ETDEWEB)

    Skinner, C.H.

    1993-08-01

    The high brightness and short pulse duration of soft x-ray lasers provide unique advantages for novel applications. Imaging of biological specimens using x-ray lasers has been demonstrated by several groups. Other applications to fields such as chemistry, material science, plasma diagnostics, and lithography are beginning to emerge. We review the current status of soft x-ray lasers from the perspective of applications, and present an overview of the applications currently being developed.

  15. X-ray data booklet. Revision

    International Nuclear Information System (INIS)

    A compilation of data is presented. Included are properties of the elements, electron binding energies, characteristic x-ray energies, fluorescence yields for K and L shells, Auger energies, energy levels for hydrogen-, helium-, and neonlike ions, scattering factors and mass absorption coefficients, and transmission bands of selected filters. Also included are selected reprints on scattering processes, x-ray sources, optics, x-ray detectors, and synchrotron radiation facilities

  16. Topological X-Rays and MRIs

    Science.gov (United States)

    Lynch, Mark

    2002-01-01

    Let K be a compact subset of the interior of the unit disk D in the plane and suppose one can't see through the boundary of D and identify K. However, assume that one can take "topological X-rays" of D which measure the "density" of K along the lines of the X-rays. By taking these X-rays from all directions, a "topological MRI" is generated for…

  17. X-ray picture of the respiratory distress syndrome (shock lung)

    International Nuclear Information System (INIS)

    X-Ray picture of the respiratory distress syndrome (shock lung) in 78 patients exposed to high temperature as a result of gas condensate explosion is analyzed. X-ray and morphologic fundings in these patients are compared to those in 13 similar patients in whom acute respiratory failure developed because of other causes. Morphologic basis of the4 majority of x-ray signs of acute respiratory distress has been investigated. A relationship between respiratory distress syndrome development and changes in the heart size has been revealed, which may serve the prediction criterion

  18. Reduction of levels of radiation exposure over patients and medical staff by using additional filters of copper and aluminum on the outputs of X-ray tubes in hemodynamic equipment

    International Nuclear Information System (INIS)

    Radioprotection in hemodynamic services is extremely important. Decrease of total exposition time, better positioning of medical staff in the room, use of individual and collective protection equipment and shorter distance between the patient and the image intensifier tube are, among others, some ways to reduce the levels of radiation. It is noted that these possible forms of reducing the radiation exposition varies depending on the medical staff. Hence, the purpose of the present paper is to reduce such levels of radiation exposition in a way apart from medical staffs. It is proposed, therefore, the use of additional filters on the output of the X-ray tube in three hemodynamic equipment from different generations: detector with a flat panel of amorphous selenium, image intensifier tube with charge coupled device, and image intensifier tube with video camera. In order to quantify the quality of the images generated, a simulator made of aluminum plates and other devices was set up, so it was possible to measure and compare the acquired images. Methods of images analysis (threshold, histogram, 3D surface) were used to measure the signal/noise ratio, the spatial resolution, the contrast and the definition of the signal area, thus doubts regarding the analysis of the images among observers (inter-observers) and even for a single observer (intra-observer) can be avoided. Ionization chambers were also used in order to quantify the doses of radiation that penetrated the skin of the patients with and without the use of the filters. In all cases was found an arrangement of filters that combines quality of the images with a significant reduction of the levels of exposure to ionizing radiation, concerning both the patient and the medical staff. (author)

  19. Observation of femtosecond X-ray interactions with matter using an X-ray-X-ray pump-probe scheme.

    Science.gov (United States)

    Inoue, Ichiro; Inubushi, Yuichi; Sato, Takahiro; Tono, Kensuke; Katayama, Tetsuo; Kameshima, Takashi; Ogawa, Kanade; Togashi, Tadashi; Owada, Shigeki; Amemiya, Yoshiyuki; Tanaka, Takashi; Hara, Toru; Yabashi, Makina

    2016-02-01

    Resolution in the X-ray structure determination of noncrystalline samples has been limited to several tens of nanometers, because deep X-ray irradiation required for enhanced resolution causes radiation damage to samples. However, theoretical studies predict that the femtosecond (fs) durations of X-ray free-electron laser (XFEL) pulses make it possible to record scattering signals before the initiation of X-ray damage processes; thus, an ultraintense X-ray beam can be used beyond the conventional limit of radiation dose. Here, we verify this scenario by directly observing femtosecond X-ray damage processes in diamond irradiated with extraordinarily intense (∼10(19) W/cm(2)) XFEL pulses. An X-ray pump-probe diffraction scheme was developed in this study; tightly focused double-5-fs XFEL pulses with time separations ranging from sub-fs to 80 fs were used to excite (i.e., pump) the diamond and characterize (i.e., probe) the temporal changes of the crystalline structures through Bragg reflection. It was found that the pump and probe diffraction intensities remain almost constant for shorter time separations of the double pulse, whereas the probe diffraction intensities decreased after 20 fs following pump pulse irradiation due to the X-ray-induced atomic displacement. This result indicates that sub-10-fs XFEL pulses enable conductions of damageless structural determinations and supports the validity of the theoretical predictions of ultraintense X-ray-matter interactions. The X-ray pump-probe scheme demonstrated here would be effective for understanding ultraintense X-ray-matter interactions, which will greatly stimulate advanced XFEL applications, such as atomic structure determination of a single molecule and generation of exotic matters with high energy densities.

  20. Advanced X-ray diffractive optics

    OpenAIRE

    Vila-Comamala, J.; Jefimovs, K.; Pilvi, T.; Ritala, M; Sarkar, S S; Solak, H H; Guzenko, V.A.; Stampanoni, M.; Marone, F.; J. Raabe; G. Tzvetkov; Fink, R H; Grolimund, D.; Borca, C.N.; Kaulich, B

    2009-01-01

    X-ray microscopy greatly bene�ts from the advances in x-ray optics. At the Paul Scherrer Institut, developments in x-ray di�ractive optics include the manufacture and optimization of Fresnel zone plates (FZPs) and di�ractive optical elements for both soft and hard x-ray regimes. In particular, we demonstrate here a novel method for the production of ultra-high resolution FZPs. This technique is based on the deposition of a zone plate material (iridium) onto the sidewalls of a p...

  1. Symbiotic Stars in X-rays

    Science.gov (United States)

    Luna, G. J. M.; Sokoloski, J. L.; Mukai, K.; Nelson, T.

    2014-01-01

    Until recently, symbiotic binary systems in which a white dwarf accretes from a red giant were thought to be mainly a soft X-ray population. Here we describe the detection with the X-ray Telescope (XRT) on the Swift satellite of 9 white dwarf symbiotics that were not previously known to be X-ray sources and one that was previously detected as a supersoft X-ray source. The 9 new X-ray detections were the result of a survey of 41 symbiotic stars, and they increase the number of symbiotic stars known to be X-ray sources by approximately 30%. Swift/XRT detected all of the new X-ray sources at energies greater than 2 keV. Their X-ray spectra are consistent with thermal emission and fall naturally into three distinct groups. The first group contains those sources with a single, highly absorbed hard component, which we identify as probably coming from an accretion-disk boundary layer. The second group is composed of those sources with a single, soft X-ray spectral component, which likely arises in a region where low-velocity shocks produce X-ray emission, i.e. a colliding-wind region. The third group consists of those sources with both hard and soft X-ray spectral components. We also find that unlike in the optical, where rapid, stochastic brightness variations from the accretion disk typically are not seen, detectable UV flickering is a common property of symbiotic stars. Supporting our physical interpretation of the two X-ray spectral components, simultaneous Swift UV photometry shows that symbiotic stars with harder X-ray emission tend to have stronger UV flickering, which is usually associated with accretion through a disk. To place these new observations in the context of previous work on X-ray emission from symbiotic stars, we modified and extended the alpha/beta/gamma classification scheme for symbiotic-star X-ray spectra that was introduced by Muerset et al. based upon observations with the ROSAT satellite, to include a new sigma classification for sources with

  2. The Lunar X-ray Observatory (LXO)

    Science.gov (United States)

    Porter, F. Scott

    2008-01-01

    X-ray emission from charge exchange recombination between the highly ionized solar wind and neutral material i n Earth's magnetosheath has complicated x-ray observations of celestial objects with x-ray observatories including ROSAT, Chandra, XMM-Newton, and Suzaku. However, the charge-exchange emission can also be used as an important diagnostic of the solar-wind interacting with the magnetosheath. Soft x-ray observations from low-earth orbit or even the highly eccentric orbits of Chandra and XMM-Newton are likely superpositions of the celestial object of interest, the true extra-solar soft x-ray background, geospheric charge exchange, and heliospheric charge exchange. We show that with a small x-ray telescope placed either on the moon, in a similar vein as the Apollo ALSOP instruments, or at a stable orbit near L1, we can begin t o disentangle the complicated emission structure in the soft x-ray band. Here we present initial results of a feasibility study recently funded by NASA t o place a small x-ray telescope on the lunar surface. The telescope operates during lunar night to observe charge exchange interactions between the solar wind and magnetospheric neutrals, between the solar wind and the lunar atmosphere, and an unobstructed view of the soft x-ray background without the geospheric component.

  3. Ultrashort X-ray pulse science

    International Nuclear Information System (INIS)

    A variety of phenomena involves atomic motion on the femtosecond time-scale. These phenomena have been studied using ultrashort optical pulses, which indirectly probe atomic positions through changes in optical properties. Because x-rays can more directly probe atomic positions, ultrashort x-ray pulses are better suited for the study of ultrafast structural dynamics. One approach towards generating ultrashort x-ray pulses is by 90o Thomson scattering between terawatt laser pulses and relativistic electrons. Using this technique, the author generated ∼ 300 fs, 30 keV (0.4 (angstrom)) x-ray pulses. These x-ray pulses are absolutely synchronized with ultrashort laser pulses, allowing femtosecond optical pump/x-ray probe experiments to be performed. Using the right-angle Thomson scattering x-ray source, the author performed time-resolved x-ray diffraction studies of laser-perturbated InSb. These experiments revealed a delayed onset of lattice expansion. This delay is due to the energy relaxation from a dense electron-hole plasma to the lattice. The dense electron-hole plasma first undergoes Auger recombination, which reduces the carrier concentration while maintaining energy content. Longitudinal-optic (LO) phonon emission then couples energy to the lattice. LO phonon decay into acoustic phonons, and acoustic phonon propagation then causes the growth of a thermally expanded layer. Source characterization is instrumental in utilizing ultrashort x-ray pulses in time-resolved x-ray spectroscopies. By measurement of the electron beam diameter at the generation point, the pulse duration of the Thomson scattered x-rays is determined. Analysis of the Thomson scattered x-ray beam properties also provides a novel means of electron bunch characterization. Although the pulse duration is inferred for the Thomson scattering x-ray source, direct measurement is required for other x-ray pulse sources. A method based on the laser-assisted photoelectric effect (LAPE) has been

  4. X-ray pulsar rush in 1998

    Energy Technology Data Exchange (ETDEWEB)

    Imanishi, K.; Tsujimoto, K.; Nishiuchi, Mamiko; Yokogawa, J.; Koyama, K. [Kyoto Univ., Faculty of Science, Kyoto (Japan)

    1999-08-01

    We present recent remarkable topics about discoveries of X-ray pulsars. 1. Pulsations from two Soft Gamma-ray Repeaters: These pulsars have enormously strong magnetic field (B {approx} 10{sup 15} G), thus these are called as 'magnetar', new type of X-ray pulsars. 2. New Crab-like pulsars: These discoveries lead to suggesting universality of Crab-like pulsars. 3. An X-ray bursting millisecond pulsar: This is strong evidence for the recycle theory of generating radio millisecond pulsars. 4. X-ray pulsar rush in the SMC: This indicates the younger star formation history in the SMC. (author)

  5. Ultrashort X-ray pulse science

    Energy Technology Data Exchange (ETDEWEB)

    Chin, Alan Hap [Univ. of California, Berkeley, CA (US). Dept. of Physics; Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    1998-05-01

    A variety of phenomena involves atomic motion on the femtosecond time-scale. These phenomena have been studied using ultrashort optical pulses, which indirectly probe atomic positions through changes in optical properties. Because x-rays can more directly probe atomic positions, ultrashort x-ray pulses are better suited for the study of ultrafast structural dynamics. One approach towards generating ultrashort x-ray pulses is by 90{sup o} Thomson scattering between terawatt laser pulses and relativistic electrons. Using this technique, the author generated {approx} 300 fs, 30 keV (0.4 {angstrom}) x-ray pulses. These x-ray pulses are absolutely synchronized with ultrashort laser pulses, allowing femtosecond optical pump/x-ray probe experiments to be performed. Using the right-angle Thomson scattering x-ray source, the author performed time-resolved x-ray diffraction studies of laser-perturbated InSb. These experiments revealed a delayed onset of lattice expansion. This delay is due to the energy relaxation from a dense electron-hole plasma to the lattice. The dense electron-hole plasma first undergoes Auger recombination, which reduces the carrier concentration while maintaining energy content. Longitudinal-optic (LO) phonon emission then couples energy to the lattice. LO phonon decay into acoustic phonons, and acoustic phonon propagation then causes the growth of a thermally expanded layer. Source characterization is instrumental in utilizing ultrashort x-ray pulses in time-resolved x-ray spectroscopies. By measurement of the electron beam diameter at the generation point, the pulse duration of the Thomson scattered x-rays is determined. Analysis of the Thomson scattered x-ray beam properties also provides a novel means of electron bunch characterization. Although the pulse duration is inferred for the Thomson scattering x-ray source, direct measurement is required for other x-ray pulse sources. A method based on the laser-assisted photoelectric effect (LAPE) has

  6. Imaging with x-ray lasers

    Energy Technology Data Exchange (ETDEWEB)

    Da Silva, L.B.; Cauble, B.; Frieders, G.; Koch, J.A.; MacGowan, B.J.; Matthews, D.L.; Mrowka, S.; Ress, D.; Trebes, J.E.; Weiland, T.L.

    1993-11-01

    Collisionally pumped soft x-ray lasers now operate over a wavelength range extending from 35--300 {Angstrom}. These sources have high peak brightness and are now being utilized for x-ray imaging and plasma interferometry. In this paper we will describe our efforts to probe long scalelength plasmas using Moire deflectrometry and soft x-ray imaging. The progress in the development of short pulse x-ray lasers using a double pulse irradiation technique which incorporates a travelling wave pump will also be presented.

  7. X-ray Emission from Elliptical Galaxies

    OpenAIRE

    Sarazin, Craig L.

    1996-01-01

    Elliptical galaxies are generally luminous sources of X-ray radiation, and contain large amounts of hot, interstellar gas. In the brighter X-ray galaxies, the inferred masses of hot gas are consistent with those expected given the present rates of stellar mass loss. The required rates of heating of the gas are also roughly consistent with those expected from the motions of gas losing stars. X-ray observations, particularly X-ray spectra, require a low rate of Type Ia supernova heating and che...

  8. X-ray Observations of Planetary Nebulae

    OpenAIRE

    Guerrero, M. A.; Chu, Y.-H.; Gruendl, R A

    2003-01-01

    Planetary nebulae (PNe) are an exciting addition to the zoo of X-ray sources. Recent Chandra and XMM-Newton observations have detected diffuse X-ray emission from shocked fast winds in PN interiors as well as bow-shocks of fast collimated outflows impinging on the nebular envelope. Point X-ray sources associated with PN central stars are also detected, with the soft X-ray (>0.5 keV) emission from instability shocks in the fast stellar wind itself or from a low-mass companion's coronal activit...

  9. X-ray pulsars: a review

    CERN Document Server

    Caballero, I

    2012-01-01

    Accreting X-ray pulsars are among the most luminous objects in the X-ray sky. In highly magnetized neutron stars (B~10^12 G), the flow of matter is dominated by the strong magnetic field. The general properties of accreting X-ray binaries are presented, focusing on the spectral characteristics of the systems. The use of cyclotron lines as a tool to directly measure a neutron star's magnetic field and to test the theory of accretion are discussed. We conclude with the current and future prospects for accreting X-ray binary studies.

  10. Hard X-ray Modulation Telescope

    Institute of Scientific and Technical Information of China (English)

    LU Fangjun

    2011-01-01

    The Hard X-ray Modulation Telescope (HXMT) will be China's first astronomical satellite. On board HXMT there are three kinds of slat-collimated telescopes, the High Energy X-ray Telescope (HE, 20-250 keV, 5000 cm^2), the Medium Energy X-ray Telescope (ME, 5-30 keV, 952 cm^2), and the Low Energy X-ray Telescope (LE, 1-15 keV, 384 cm^2).

  11. X-rays from the youngest stars

    Science.gov (United States)

    Feigelson, Eric D.

    1994-01-01

    The X-ray properties of classical and weak-lined T Tauri stars are briefly reviewed, emphasizing recent results from the ROSAT satellite and prospects for ASCA. The interpretation of the high level of T Tauri X-rays as enhanced solar-type magnetic activity is discussed and criticized. The census of X-ray emitters is significantly increasing estimates of galactic star formation efficiency, and X-ray emission may be important for self-regulation of star formation. ASCA images will detect star formation regions out to several kiloparsecs and will study the magnetically heated plasma around T Tauri stars. However, images will often suffer from crowding effects.

  12. Automated Quality Assurance of Medical Digital X-Ray Equipment

    International Nuclear Information System (INIS)

    Quality assurance of the x-ray equipment includes a set of various tests among which are installation and periodic exams performed by qualified engineers as well as daily routine tests carried out by the medical staff of the Radiology Department. As a rule, the decision concerning the applicability of the x-ray equipment for using in clinical studies is made on the basis of the routine tests results. The presented method is based on the detector's output signals, Signal-to-Noise Ratio and Modulation Transfer Function evaluation in automated way using the simple test-object's digital image registered with given geometry and x-ray exposure parameters settings. Rectangular 20 mm thick aluminum plate with fixed 1 mm thick well-finished steel edge (for general x-ray radiography/fluoroscopy systems) or 2 mm thick aluminum plate with fixed 1 mm thick aluminum well-finished edge (for digital x-ray mammography systems) can be used as a test equipment. Relevant to the decision concerning the x-ray device operation status are the parameters: deviations from the reference levels of the tube voltage and mAs as well as internal detector's noise variance and detector's gain deviations. Everyday testing procedure includes the following steps. On the first step the roentgenographer places the test-object at the center of the detector's surface, makes an exposure with specified parameters setting and geometry and after this, test results are displayed on the work station monitor or console screen in automatic way. In order to provide an automated regime of the presenting algorithm, the software must be integrated with the program module intended for the x-ray device control. The use of the presented method in clinical practice provides the reliable daily monitoring of the x-ray equipment operation status prior to its utilizing for patient diagnostic process. As a rule, it will take not more than 3-5 minutes for the roentgenographer to complete the routine

  13. X-ray imaging using a tunable coherent X-ray source based on parametric X-ray radiation

    International Nuclear Information System (INIS)

    A novel X-ray source based on parametric X-ray radiation (PXR) has been employed for X-ray imaging at the Laboratory for Electron Beam Research and Application (LEBRA), Nihon University. Notable features of PXR are tunable energy, monochromaticity with spatial chirp, narrow local bandwidth and spatial coherence. Since the X-ray beam from the PXR system has a large irradiation area with uniform flux density, the PXR-based source is suited for X-ray imaging, especially for application to phase-contrast imaging. Despite the cone-like X-ray beam, diffraction-enhanced imaging (DEI) can be employed as a phase contrast imaging technique. DEI experiments were performed using 14- to 34-keV X-rays and the phase-gradient images were obtained. The results demonstrated the capability of PXR as an X-ray source for phase-contrast imaging with a large irradiation field attributed to the cone-beam effect. Given the significant properties of the LEBRA-PXR source, the result suggests the possible construction of a compact linac-driven PXR-Imaging instrument and its application to medical diagnoses

  14. A Coordinated X-ray and Optical Campaign on the Nearest Massive Eclipsing Binary, Delta Ori Aa: I. Overview of the X-ray Spectrum

    CERN Document Server

    Corcoran, M F; Pablo, H; Shenar, T; Pollock, A M T; Waldron, W L; Moffat, A F J; Richardson, N D; Russell, C M P; Hamaguchi, K; Huenemoerder, D P; Oskinova, L; Hamann, W -R; Naze, Y; Ignace, R; Evans, N R; Lomax, J R; Hoffman, J L; Gayley, K; Owocki, S P; Leutenegger, M; Gull, T R; Hole, K T; Lauer, J; Iping, R C

    2015-01-01

    We present an overview of four phase-constrained Chandra HETGS X-ray observations of Delta Ori A. Delta Ori A is actually a triple system which includes the nearest massive eclipsing spectroscopic binary, Delta Ori Aa, the only such object which can be observed with little phase-smearing with the Chandra gratings. Since the fainter star, Delta Ori Aa2, has a much lower X-ray luminosity than the brighter primary, Delta Ori A provides a unique system with which to test the spatial distribution of the X-ray emitting gas around Delta Ori Aa1 via occultation by the photosphere of and wind cavity around the X-ray dark secondary. Here we discuss the X-ray spectrum and X-ray line profiles for the combined observation, having an exposure time of nearly 500 ksec and covering nearly the entire binary orbit. Companion papers discuss the X-ray variability seen in the Chandra spectra, present new space-based photometry and ground-based radial velocities simultaneous with the X-ray data to better constrain the system parame...

  15. Diagnostic x-ray procedures and risk of leukemia, lymphoma, and multiple myeloma

    International Nuclear Information System (INIS)

    Exposure to diagnostic x-rays and the risk of leukemia, non-Hodgkin's lymphoma (NHL), and multiple myeloma were studied within two prepaid health plans. Adult patients with leukemia (n = 565), NHL (n = 318), and multiple myeloma (n = 208) were matched to controls (n = 1390), and over 25,000 x-ray procedures were abstracted from medical records. Dose response was evaluated by assigning each x-ray procedure a score based on estimated bone marrow dose. X-ray exposure was not associated with chronic lymphocytic leukemia, one of the few malignant conditions never linked to radiation (relative risk [RR], 0.66). For all other forms of leukemia combined (n = 358), there was a slight elevation in risk (RR, 1.17) but no evidence of a dose-response relationship when x-ray procedures near the time of diagnosis were excluded. Similarly, patients with NHL were exposed to diagnostic x-ray procedures more often than controls (RR, 1.32), but the RR fell to 0.99 when the exposure to diagnostic x-ray procedures within 2 years of diagnosis was ignored. For multiple myeloma, overall risk was not significantly high (RR, 1.14), but there was consistent evidence of increasing risk with increasing numbers of diagnostic x-ray procedures. These data suggest that persons with leukemia and NHL undergo x-ray procedures frequently just prior to diagnosis for conditions related to the development or natural history of their disease. There was little evidence that diagnostic x-ray procedures were causally associated with leukemia or NHL. The risk for multiple myeloma, however, was increased among those patients who were frequently exposed to x-rays

  16. X-ray scan detection for cargo integrity

    Science.gov (United States)

    Valencia, Juan; Miller, Steve

    2011-04-01

    The increase of terrorism and its global impact has made the determination of the contents of cargo containers a necessity. Existing technology allows non-intrusive inspections to determine the contents of a container rapidly and accurately. However, some cargo shipments are exempt from such inspections. Hence, there is a need for a technology that enables rapid and accurate means of detecting whether such containers were non-intrusively inspected. Non-intrusive inspections are most commonly performed utilizing high powered X-ray equipment. The challenge is creating a device that can detect short duration X-ray scans while maintaining a portable, battery powered, low cost, and easy to use platform. The Pacific Northwest National Laboratory (PNNL) has developed a methodology and prototype device focused on this challenge. The prototype, developed by PNNL, is a battery powered electronic device that continuously measures its X-ray and Gamma exposure, calculates the dose equivalent rate, and makes a determination of whether the device has been exposed to the amount of radiation experienced during an X-ray inspection. Once an inspection is detected, the device will record a timestamp of the event and relay the information to authorized personnel via a visual alert, USB connection, and/or wireless communication. The results of this research demonstrate that PNNL's prototype device can be effective at determining whether a container was scanned by X-ray equipment typically used for cargo container inspections. This paper focuses on laboratory measurements and test results acquired with the PNNL prototype device using several X-ray radiation levels.

  17. On the universal X-ray luminosity function of binary X-ray sources in galaxies

    OpenAIRE

    Postnov, K. A.

    2002-01-01

    The empirically determined universal power-law shape of X-ray luminosity function of high mass X-ray binaries in galaxies is explained by fundamental mass-luminosity and mass-radius relations for massive stars.

  18. SN X-ray Progenitor?

    Science.gov (United States)

    2008-01-01

    Identifying stars that explode, right before they explode, is a tricky proposition since the end of starlife comes swiftly: in thermonuclear deflagrations, in nuclear exhaustion, or maybe in a rapid swirling merger of two dead stellar cores. On the right in the image above is an image of the galaxy NGC 1404 taken by the UV/optical Telescope (UVOT) on the Swift observatory. The circle surrounds SN 2007on, a supernova of Type Ia produced by the explosion of a white dwarf star in a binary system. These types of supernovae are important since they are believed to be 'standard candles', events which have the same intrinsic brightness which can serve as an important yardstick to measure cosmic distances. On the left is an image of the same galaxy taken by the Chandra X-ray observatory four years before the supernova. Conspicuous in the SN source circle is a bright source in the Chandra image, believed to be emission from a compact object+normal star companion: a similar system to the supposed precursor of SN 2007on. If true this would be the first time a Type Ia supernova precursor has ever been seen. But astronomers are still debating whether the Chandra source really is the precursor or not; it seems there's a slight but significant difference in the location of the Chandra source and the supernova. Stay tuned for more developments.

  19. X-ray radiography facility

    International Nuclear Information System (INIS)

    The paper described a radiographic apparatus containing a radiation source, a diaphragm with collimating windows and a cassette holder with a cassette for the X-ray film. In order to increase the efficiency and quality of monitoring, the diaphragm and the cassette are made in the form of cylindrical shells, the centre of curvature of which coincides with the position of the radiation source focus. Each collimating window of the diaphragm is made in the form of two coaxially connected truncated cones, joined at the large bases in such a way that the angle at the vertex of the cone nearer the source is not less than the central angle with the vertex at the focus of the radiation source supported by the larger base, and 15-300 less than the angle at the vertex of the cone further from the source. By this means monitoring efficiency is increased by a factor of 1.5-2 and the quality of the radiographs improved. The apparatus is used for flaw detection in cylindrical objects. (author)

  20. X-ray computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Kalender, Willi A [Institute of Medical Physics, University Erlangen-Nuernberg, Henkestr. 91, D-91052 Erlangen (Germany)

    2006-07-07

    X-ray computed tomography (CT), introduced into clinical practice in 1972, was the first of the modern slice-imaging modalities. To reconstruct images mathematically from measured data and to display and to archive them in digital form was a novelty then and is commonplace today. CT has shown a steady upward trend with respect to technology, performance and clinical use independent of predictions and expert assessments which forecast in the 1980s that it would be completely replaced by magnetic resonance imaging. CT not only survived but exhibited a true renaissance due to the introduction of spiral scanning which meant the transition from slice-by-slice imaging to true volume imaging. Complemented by the introduction of array detector technology in the 1990s, CT today allows imaging of whole organs or the whole body in 5 to 20 s with sub-millimetre isotropic resolution. This review of CT will proceed in chronological order focussing on technology, image quality and clinical applications. In its final part it will also briefly allude to novel uses of CT such as dual-source CT, C-arm flat-panel-detector CT and micro-CT. At present CT possibly exhibits a higher innovation rate than ever before. In consequence the topical and most recent developments will receive the greatest attention. (review)

  1. Diffraction leveraged modulation of X-ray pulses using MEMS-based X-ray optics

    Energy Technology Data Exchange (ETDEWEB)

    Lopez, Daniel; Shenoy, Gopal; Wang, Jin; Walko, Donald A.; Jung, Il-Woong; Mukhopadhyay, Deepkishore

    2016-08-09

    A method and apparatus are provided for implementing Bragg-diffraction leveraged modulation of X-ray pulses using MicroElectroMechanical systems (MEMS) based diffractive optics. An oscillating crystalline MEMS device generates a controllable time-window for diffraction of the incident X-ray radiation. The Bragg-diffraction leveraged modulation of X-ray pulses includes isolating a particular pulse, spatially separating individual pulses, and spreading a single pulse from an X-ray pulse-train.

  2. Accelerator-driven X-ray Sources

    Energy Technology Data Exchange (ETDEWEB)

    Nguyen, Dinh Cong [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2015-11-09

    After an introduction which mentions x-ray tubes and storage rings and gives a brief review of special relativity, the subject is treated under the following topics and subtopics: synchrotron radiation (bending magnet radiation, wiggler radiation, undulator radiation, brightness and brilliance definition, synchrotron radiation facilities), x-ray free-electron lasers (linac-driven X-ray FEL, FEL interactions, self-amplified spontaneous emission (SASE), SASE self-seeding, fourth-generation light source facilities), and other X-ray sources (energy recovery linacs, Inverse Compton scattering, laser wakefield accelerator driven X-ray sources. In summary, accelerator-based light sources cover the entire electromagnetic spectrum. Synchrotron radiation (bending magnet, wiggler and undulator radiation) has unique properties that can be tailored to the users’ needs: bending magnet and wiggler radiation is broadband, undulator radiation has narrow spectral lines. X-ray FELs are the brightest coherent X-ray sources with high photon flux, femtosecond pulses, full transverse coherence, partial temporal coherence (SASE), and narrow spectral lines with seeding techniques. New developments in electron accelerators and radiation production can potentially lead to more compact sources of coherent X-rays.

  3. X-ray topography and multiple diffraction

    International Nuclear Information System (INIS)

    A short summary on X-ray topography, which is based on the dynamical theory of X-ray diffraction, is made. The applications and properties related to the use of the multiple diffraction technique are analized and discussed. (L.C.)

  4. Soft x rays for radiobiological studies

    International Nuclear Information System (INIS)

    Lethal effects and chromosome aberrations induced in cells exposed to low energy (soft) X rays demonstrated that these relatively low energy X rays are just as effective as those of higher energy for radiobiological studies, and even more effective for irradiating cultured mammalian cells than laboratory animals. (author)

  5. Coccidioidomycosis - chest x-ray (image)

    Science.gov (United States)

    This chest x-ray shows the affects of a fungal infection, coccidioidomycosis. In the middle of the left lung (seen on the ... defined borders. Other diseases that may explain these x-ray findings include lung abscesses, chronic pulmonary tuberculosis, chronic ...

  6. X-Ray Detection Visits the Classroom

    Science.gov (United States)

    Peralta, Luis; Farinha, Ana; Pinto, Ana

    2008-01-01

    Film has been used to detect x-rays since the early days of their discovery by Rontgen. Although nowadays superseded by other techniques, film still provides a cheap means of x-ray detection, making it attractive in high-school or undergraduate university courses. If some sort of quantitative result is required, the film's optical absorbance or…

  7. Adenocarcinoma - chest x-ray (image)

    Science.gov (United States)

    This chest x-ray shows adenocarcinoma of the lung. There is a rounded light spot in the right upper lung (left side ... density. Diseases that may cause this type of x-ray result would be tuberculous or fungal granuloma, and ...

  8. Tracing the X-Ray Trail

    Science.gov (United States)

    What you need to know about… Tracing the X-ray Trail If you’ve just completed an x-ray, computed tomography (CT), magnetic resonance (MR) Start here! or other diagnostic imaging procedure, you probably want to know when you will ... los rayos X Si acaba de hacerse una radiografía, tomografía ¡Empezar ...

  9. Proton induced X-ray emission analysis

    International Nuclear Information System (INIS)

    The developments in proton induced X-ray emission analysis are reviewed. Techniques for analyzing thick and thin samples of different origin are described. Discussions on the application of proton induced X-ray emission analysis in different fields, comparison of the sensitivity of this method with other analytical techniques, its limitations and possible improvements are presented

  10. Evaluation of the Beam Quality of Intraoral X-ray Equipment using Intraoral Standard Films

    International Nuclear Information System (INIS)

    This study was to evaluate the beam quality of intraoral X-ray equipment used at Yonsei University Dental Hospital (YUDH) using the half value layer (HVL) and the characteristic curve of intraoral standard X-ray film. The study was done using the intraoral X-ray equipment used at each clinical department at YUDH. Aluminum filter was used to determine the HVL. Intraoral standard film was used to get the characteristic curve of each intraoral X-ray equipment. Most of the HVLs of intraoral X-ray equipment were higher than the least recommended thickness, but the REX 601 model used at the operative dentistry department and the X-707 model used at the pediatric dentistry department had HVLs lower than the recommended thickness. The slopes of the characteristic curves of films taken using the PANPAS 601 model and REX 601 model at operative dentistry department, the X-70S model of prosthodontic dentistry department, and the REX 601 model at the student clinic were relatively low. HVL and the characteristic curve of X-ray film can be used to evaluate the beam quality of intraoral X-ray equipment. In order to get the best X-ray films with the least radiation exposure to patients and best diagnostic information in clinical dentistry, X-ray equipment should be managed in the planned and organized fashion.

  11. Hard X-ray irradiation of cosmic silicate analogs: structural evolution and astrophysical implications

    CERN Document Server

    Gavilan, L; Simionovici, A; Lemaire, J L; Sabri, T; Foy, E; Yagoubi, S; Henning, T; Salomon, D; Martinez-Criado, G

    2016-01-01

    Protoplanetary disks, interstellar clouds, and active galactic nuclei, contain X-ray dominated regions. X-rays interact with the dust and gas present in such environments. While a few laboratory X-ray irradiation experiments have been performed on ices, X-ray irradiation experiments on bare cosmic dust analogs have been scarce up to now. Our goal is to study the effects of hard X-rays on cosmic dust analogs via in-situ X-ray diffraction. By using a hard X-ray synchrotron nanobeam, we seek to simulate cumulative X-ray exposure on dust grains during their lifetime in these astrophysical environments, and provide an upper limit on the effect of hard X-rays on dust grain structure. We prepared enstatite nanograins, analogs to cosmic silicates, via the melting-quenching technique. These amorphous grains were then annealed to obtain polycrystalline grains. These were characterized via scanning electron microscopy and high-resolution transmission electron microscopy before irradiation. Powder samples were prepared i...

  12. Discovery of low-redshift X-ray selected quasars - New clues to the QSO phenomenon

    Science.gov (United States)

    Grindlay, J. E.; Forman, W. R.; Steiner, J. E.; Canizares, C. R.; Mcclintock, J. E.

    1980-01-01

    The identification of six X-ray sources discovered by the Einstein Observatory with X-ray quasars is reported, and the properties of these X-ray selected quasars are discussed. The four high-latitude fields of 1 sq deg each in which the Einstein imaging proportional counter detected serendipitous X-ray sources at intermediate exposures of 10,000 sec were observed by 4-m and 1.5-m telescopes, and optical sources with uv excesses and emission line spectra typical of many low-redshift quasars and Seyfert 1 galaxies were found within the 1-arcsec error boxes of the X-ray sources. All six quasars identified were found to be radio quiet, with low redshift and relatively faint optical magnitudes, and to be similar in space density, colors and magnitude versus redshift relation to an optically selected sample at the same mean magnitude. X-ray luminosity was found to be well correlated with both continuum and broad-line emission luminosities for the known radio-quiet quasars and Seyfert 1 galaxies, and it was observed that the five objects with the lowest redshifts have very similar X-ray/optical luminosity ratios despite tenfold variations in X-ray luminosity. It is concluded that photoionization by a continuum extending to X-ray energies is the dominant excitation mechanism in radio-quiet quasars.

  13. X-ray scattering measurements from thin-foil x-ray mirrors

    DEFF Research Database (Denmark)

    Christensen, Finn Erland; BYRNAK, BP; Hornstrup, Allan;

    1992-01-01

    Thin foil X-ray mirrors are to be used as the reflecting elements in the telescopes of the X-ray satellites Spectrum-X-Gamma (SRG) and ASTRO-D. High resolution X-ray scattering measurements from the Au coated and dip-lacquered Al foils are presented. These were obtained from SRG mirrors positione...

  14. Characterization of Metalloproteins and Biomaterials by X-ray Absorption Spectroscopy and X-ray Diffraction

    DEFF Research Database (Denmark)

    Frankær, Christian Grundahl

    This thesis presents thework on combining complementary X-rays techniques for studying the structures of proteins and other biomaterials, and consists of three different projects: (i) Characterization of protein powders with X-ray powder diffraction (XRPD). (ii) The combination of X-ray crystallo...

  15. Soft X-Ray Spectra of AGN Discovered Via Their Hard X-Ray

    Science.gov (United States)

    Schwartz, Daniel

    1998-01-01

    This final report is a study of the Active Galactic Nuclei (AGN). Investigation of the soft x-ray spectra of AGN were performed by using their hard x-ray emission. ROSAT observations of AGN was also performed, which allowed for the study of these x-ray spectra and the structures of 7 clusters of galaxies.

  16. Chromosome aberrations and environmental exposures in acute leukemia

    OpenAIRE

    Lindquist, Ragnhild Rosengren

    2009-01-01

    The aims of this thesis are to evaluate the role of environmental exposures, especially professional exposure to organic solvents and petroleum products in the etiology of acute leukemia and to investigate if there is a correlation between the exposure to a specific leukemogen factor and a clonal chromosome aberration of the leukemic cells. Papers I and II present results of a case-control study of environmental exposures, in all occupations during life-time, medical treatm...

  17. Motorized Beam Alignment of a Commercial X-ray Diffractometer

    Science.gov (United States)

    Van Zandt, Noah R.; Myers, James F.; Rogers, Richard B

    2013-01-01

    X-ray diffraction (XRD) is a powerful analysis method that allows researchers to noninvasively probe the crystalline structure of a material. This includes the ability to determine the crystalline phases present, quantify surface residual stresses, and measure the distribution of crystallographic orientations. The Structures and Materials Division at the NASA Glenn Research Center (GRC) heavily uses the on-site XRD lab to characterize advanced metal alloys, ceramics, and polymers. One of the x-ray diffractometers in the XRD lab (Bruker D8 Discover) uses three different x-ray tubes (Cu, Cr, and Mn) for optimal performance over numerous material types and various experimental techniques. This requires that the tubes be switched out and aligned between experiments. This alignment maximizes the x-ray tube s output through an iterative process involving four set screws. However, the output of the x-ray tube cannot be monitored during the adjustment process due to standard radiation safety engineering controls that prevent exposure to the x-ray beam when the diffractometer doors are open. Therefore, the adjustment process is a very tedious series of blind adjustments, each followed by measurement of the output beam using a PIN diode after the enclosure doors are shut. This process can take up to 4 hr to perform. This technical memorandum documents an in-house project to motorize this alignment process. Unlike a human, motors are not harmed by x-ray radiation of the energy range used in this instrument. Therefore, using motors to adjust the set screws will allow the researcher to monitor the x-ray tube s output while making interactive adjustments from outside the diffractometer. The motorized alignment system consists of four motors, a motor controller, and a hand-held user interface module. Our goal was to reduce the alignment time to less than 30 min. The time available was the 10-week span of the Lewis' Educational and Research Collaborative Internship Project (LERCIP

  18. An X-ray view of quasars

    CERN Document Server

    Singh, K P

    2013-01-01

    I present an overview of observational studies of quasars of all types, with particular emphasis on X-ray observational studies. The presentation is based on the most popularly accepted unified picture of quasars - collectively referred to as AGN (active galactic nuclei) in this review. Characteristics of X-ray spectra and X-ray variability obtained from various X-ray satellites over the last 5 decades have been presented and discussed. The contribution of AGN in understanding the cosmic X-ray background is discussed very briefly. Attempt has been made to provide up-to-date information; however, this is a vast subject and this presentation is not intended to be comprehensive.

  19. X-ray Fourier ptychographic microscopy

    CERN Document Server

    Simons, H; Guigay, J P; Detlefs, C

    2016-01-01

    Following the recent developement of Fourier ptychographic microscopy (FPM) in the visible range by Zheng et al. (2013), we propose an adaptation for hard x-rays. FPM employs ptychographic reconstruction to merge a series of low-resolution, wide field of view images into a high-resolution image. In the x-ray range this opens the possibility to overcome the limited numerical aperture of existing x-ray lenses. Furthermore, digital wave front correction (DWC) may be used to charaterize and correct lens imperfections. Given the diffraction limit achievable with x-ray lenses (below 100 nm), x-ray Fourier ptychographic microscopy (XFPM) should be able to reach resolutions in the 10 nm range.

  20. High Energy Vision: Processing X-rays

    CERN Document Server

    DePasquale, Joseph; Edmonds, Peter

    2015-01-01

    Astronomy is by nature a visual science. The high quality imagery produced by the world's observatories can be a key to effectively engaging with the public and helping to inspire the next generation of scientists. Creating compelling astronomical imagery can, however, be particularly challenging in the non-optical wavelength regimes. In the case of X-ray astronomy, where the amount of light available to create an image is severely limited, it is necessary to employ sophisticated image processing algorithms to translate light beyond human vision into imagery that is aesthetically pleasing while still being scientifically accurate. This paper provides a brief overview of the history of X-ray astronomy leading to the deployment of NASA's Chandra X-ray Observatory, followed by an examination of the specific challenges posed by processing X-ray imagery. The authors then explore image processing techniques used to mitigate such processing challenges in order to create effective public imagery for X-ray astronomy. ...

  1. X-Rays from Green Pea Analogs

    Science.gov (United States)

    Brorby, Matthew

    2014-09-01

    X-rays may have contributed to the heating and reionization of the IGM in the early universe. High mass X-ray binaries (HMXB) within small, low-metallicity galaxies are expected to be the main source of X-rays at this time. Since studying these high-redshift galaxies is currently impossible, we turn to local analogs that have the same properties the galaxies in the early are expected to have. A number of recent studies have shown an enhanced number of HMXBs in nearby low metallicity galaxies. We propose to observe a sample of metal-deficient luminous compact galaxies (LCG) in order to determine if the X-ray luminosity is enhanced relative to SFR, thereby providing further evidence to the importance of X-rays in the early universe.

  2. The X-ray imager on AXO

    DEFF Research Database (Denmark)

    Budtz-Jørgensen, Carl; Kuvvetli, Irfan; Westergaard, Niels Jørgen Stenfeldt;

    2001-01-01

    DSRI has initiated a development program of CZT X-ray and gamma-ray detectors employing strip readout techniques. A dramatic improvement of the energy response was found operating the detectors as the so-called drift detectors. For the electronic readout, modern ASIC chips were investigated....... Modular design and the low-power electronics will make large area detectors using the drift strip method feasible. The performance of a prototype CZT system will be presented and discussed. One such detector system has been proposed for future space missions: the X-Ray Imager (XRI) on the Atmospheric X-ray...... Observatory (AXO), which is a mission proposed to the Danish Small Satellite Program and is dedicated to observations of X-ray generating processes in the Earth's atmosphere. Of special interest will be simultaneous optical and X-ray observations of sprites that are flashes appearing directly above an active...

  3. Observational Aspects of Hard X-ray Polarimetry

    Science.gov (United States)

    Chattopadhyay, Tanmoy

    2016-04-01

    of such hard X-ray telescopes, which may provide sensitive polarization measurements due to flux concentration in hard X-rays with a very low background. On the other hand, such a configuration ensures implementation of an optimized geometry close to an ideal one for the Compton polarimeters. In this context, we initiated the development of a focal plane Compton polarimeter, consisting of a plastic scatterer surrounded by a cylindrical array of CsI(Tl) scintillators. Geant-4 simulations of the planned configuration estimates 1% MDP for a 100 mCrab source in 1 million seconds of exposure. Sensitivity of the instrument is found to be critically dependent on the lower energy detection limit of the plastic scatterer; lower the threshold, better is the sensitivity. In the actual experiment, the plastic is readout by a photomultiplier tube procured from Saint-Gobain. We carried out extensive experiments to characterize the plastic especially for lower energy depositions. The CsI(Tl) scintillators are readout by Si photomultipliers (SiPM). SiPMs are small in size and robust and therefore provide the compactness necessary for the designing of focal plane detectors. Each of the CsI(Tl)-SiPM systems was characterized precisely to estimate their energy threshold and detection probability along the length of the scintillators away from SiPM. Finally, we integrated the Compton polarimeter and tested its response to polarized and unpolarized radiation and compared the experimental results with Geant-4 simulation. Despite the growing realization of the scientific values of X-ray polarimetry and the efforts in developing sensitive X-ray polarimeters, there has not been a single dedicated X-ray polarimetry mission planned in near future. In this scenario, it is equally important to attempt polarization measurements from the existing or planned instruments which are not meant for X-ray polarization measurements but could be sensitive to it. There have been several attempts in past in

  4. Application of imaging plate to micro-beam X-ray diffraction

    International Nuclear Information System (INIS)

    A new type of integrating area detector system with high sensitivity and high spatial resolution was recently developed for diagnostic radiography. In this detector system, a two dimensional X-ray image is temporarily stored as a distribution of F-centers in a photostimulable phosphor screen called the imaging plate (IP). The image in the IP is then read out by measuring the intensity of fluorescence which is stimulated by a focused He-Ne laser beam scanning the surface of the phosphor screen. The residual X-ray image in the IP can be erased simply by exposing it to a large dose of visible light and the IP can be used repeatedly. The detector has 100% detective quantum efficiency for 0-20 keV X-ray, a spatial resolution better than 0.15mm(fwhm), a dynamic range of 105 and no counting rate limitation. The exposure time can be shorten to 1/20-1/60 in comparison with the use of the X-ray film. In this study, we examined the possibility of the IP for the X-ray studies on the mechanical behaviour of materials by using the back-reflection X-ray technique. An exposure time of more than 30 minutes would be required for a conventional high sensitivity X-ray film in the case of αFe(211) diffraction by Cr-Kα X-rays. When the imaging plates were used in place of the film under the same X-ray condition, we could obtain visually similar patterns by exposing the time of less than 90 seconds. These diffraction patterns can be precisely analyzed with the help of the image processing analyzer. We conclude that this detector system is usable in almost the same way as an X-ray film. Especially, this will be more powerful means in the field of micro-beam X-ray diffraction. (author)

  5. Two digital X-ray imaging systems for applications in X-ray diffraction

    International Nuclear Information System (INIS)

    Two digital X-ray imaging systems developed at the Rutherford Appleton Laboratory are described: the Mark I and the Mark II. Both use a bidimensionally sensitive multiwire proportional counter (MWPC) as the basic X-ray image transducer coupled, in the case of the Mark I to a Digital LSI 11-23 microcomputer system via CAMAC, and in the case of the Mark II to a Digital LSI 11-73 microcomputer system via custom-built data acquisition hardware mounted directly on the Q-bus of the microcomputer. The Mark I system provides the advantages of high speed, high sensitivity digital imaging directly into the computer with the potential for software control of the sample orientation and environment. The Mark II system adds the novel features of signal averaging and multiframe exposures. The dedicated digital memories have a resolution of 512x512 pixels of 16 bits, matching well to the spatial resolution of the xenon-filled MWPC (0.5 mm fwhm over an aperture of 200 mm x 200 mm). A 512x512x4 bit video graphics system displays the images in grey scales or colour. (orig.)

  6. The Swift X-ray monitoring campaign of the center of the Milky Way

    CERN Document Server

    Degenaar, N; Miller, J M; Reynolds, M T; Kennea, J; Gehrels, N

    2015-01-01

    In 2006 February, shortly after its launch, Swift began monitoring the center of the Milky Way with the onboard X-Ray Telescope using short 1-ks exposures performed every 1-4 days. Between 2006 and 2014, over 1200 observations have been obtained, amounting to ~1.2 Ms of exposure time. This has yielded a wealth of information about the long-term X-ray behavior of the supermassive black hole Sgr A*, and numerous transient X-ray binaries that are located within the 25'x25' region covered by the campaign. In this review we highlight the discoveries made during these first nine years, which includes 1) the detection of seven bright X-ray flares from Sgr A*, 2) the discovery of the magnetar SGR J1745-29, 3) the first systematic analysis of the outburst light curves and energetics of the peculiar class of very-faint X-ray binaries, 4) the discovery of three new transient X-ray sources, 5) exposing low-level accretion in otherwise bright X-ray binaries, and 6) the identification of a candidate X-ray binary/millisecon...

  7. X-ray Spectral Variation of Eta Carinae through the 2003 X-ray Minimum

    OpenAIRE

    Hamaguchi, Kenji; Corcoran, Michael F.; Gull, Theodore; Ishibashi, Kazunori; Pittard, Julian M.; Hillier, D. John; Damineli, Augusto; Davidson, Kris; Nielsen, Krister E.; Kober, Gladys Vieira

    2007-01-01

    We report the results of an X-ray observing campaign on the massive, evolved star Eta Carinae, concentrating on the 2003 X-ray minimum as seen by the XMM-Newton observatory. These are the first spatially-resolved X-ray monitoring observations of the stellar X-ray spectrum during the minimum. The hard X-ray emission, believed to be associated with the collision of Eta Carinae's wind with the wind from a massive companion star, varied strongly in flux on timescales of days, but not significantl...

  8. Large area soft x-ray collimator to facilitate x-ray optics testing

    Science.gov (United States)

    Espy, Samuel L.

    1994-01-01

    The first objective of this program is to design a nested conical foil x-ray optic which will collimate x-rays diverging from a point source. The collimator could then be employed in a small, inexpensive x-ray test stand which would be used to test various x-ray optics and detector systems. The second objective is to demonstrate the fabrication of the x-ray reflectors for this optic using lacquer-smoothing and zero-stress electroforming techniques.

  9. First X-ray fluorescence CT experimental results at the SSRF X-ray imaging beamline

    Institute of Scientific and Technical Information of China (English)

    DENG Biao; YANG Qun; XIE Hong-Lan; DU Guo-Hao; XIAO Wi-Qiao

    2011-01-01

    X-ray fluorescence CT is a non-destructive technique for detecting elemental composition and distribution inside a specimen. In this paper, the first experimental results of X-ray fluorescence CT obtained at the SSRF X-ray imaging beamline (BL13W1) are described. The test samples were investigated and the 2D elemental image was reconstructed using a filtered back-projection algorithm. In the sample the element Cd was observed. Up to now, the X-ray fluorescence CT could be carried out at the SSRF X-ray imaging beamline.

  10. Laser plasma x-ray source for ultrafast time-resolved x-ray absorption spectroscopy

    OpenAIRE

    Miaja-Avila, L.; G. C. O'Neil; Uhlig, J.; C. L. Cromer; Dowell, M. L.; Jimenez, R.; Hoover, A. S.; Silverman, K. L.; Ullom, J. N.

    2015-01-01

    We describe a laser-driven x-ray plasma source designed for ultrafast x-ray absorption spectroscopy. The source is comprised of a 1 kHz, 20 W, femtosecond pulsed infrared laser and a water target. We present the x-ray spectra as a function of laser energy and pulse duration. Additionally, we investigate the plasma temperature and photon flux as we vary the laser energy. We obtain a 75 μm FWHM x-ray spot size, containing ∼106 photons/s, by focusing the produced x-rays with a polycapillary opti...

  11. Distribution of X-ray examinations within the Danish population

    International Nuclear Information System (INIS)

    Full text: Medical X-ray exposures are the largest source of man-made exposure to ionising radiation in developed countries. Therefore, there is an interest to determine the population dose from medical X-rays, for the population as a whole as well as for selected groups, for instance for different age groups. In order to determine these quantities, knowledge of the frequency of X-ray examinations for different age groups is needed. In Denmark, 95% of all hospitals are public, and more than 95% of all procedures in hospitals are carried out in the public hospitals. Dental X-ray procedures are frequent but contribute very little to the population dose. Excluding dental procedures, only a limited number of X-ray procedures (estimated to be around 5% of the total number) are carried out in private clinics outside the hospitals. To assess the frequencies of X-ray procedures, it is therefore a good approximation to assess only the frequencies of procedures carried out in public hospitals. All of these procedures are registered in a national database. The data stored includes a unique identifier for each patient, sex and year of birth of the patient and the name of the procedure. In addition, data on the age and sex distribution of the population is available from national registers. Due to the presence of the unique identifiers, it is possible to assess not only the total number of examinations carried out, but also the number of examinations for each patient. In 2004, 18% of the population underwent one or more X-ray examinations, with the number of examinations varying from 1 to 101. There are marked differences between the different age groups; with frequencies ranging from 7% for the group of 0 - 4 year olds to 45% for 90+ years. Among the persons examined, more than 50% undergo more than examination, while 9% undergo more than five examinations. The types of examinations also vary considerably for different age groups. E.g., CT examinations constitute 2% of all

  12. Use of a Field Portable X-Ray Fluorescence Analyzer for Environmental Exposure Assessment of a Neighborhood in Cairo, Egypt Adjacent to the Site of a Former Secondary Lead Smelter.

    Science.gov (United States)

    Menrath, William; Zakaria, Yehia; El-Safty, Amal; Clark, C Scott; Roda, Sandy M; Elsayed, Essam; Lind, Caroline; Pesce, John; Peng, Hongying

    2015-01-01

    The objectives of this study are to demonstrate for the first time the use of a field portable X-Ray Fluorescence Analyzer (XRF) in a multi-media environmental survey and to use the survey results to determine if residual lead from a once-active secondary lead smelter in Cairo, Egypt, still posed a health risk to the residents when comparing results with US EPA standards. Results were analyzed to determine if relationships among the variables indicated that there were residual impacts of the former smelter. Samples collected inside and near a total of 194 dwellings were analyzed. The mean floor dust lead loading was 7.48 μg lead/ft(2). Almost 10% of the dwellings had at least one floor dust wipe sample that exceeded the United States Environmental Protection Agency's (USEPA) interior settled dust lead level of 40 μg lead/ft(2). The median paint lead level was 0.04 mg lead/cm(2). 17% of the dwellings had at least one interior paint sample that exceeded the USEPA standard of 1.0 mg lead/cm(2). Mean soil lead concentration in the study area was 458 ppm and 91 ppm outside the study area. Four of nine composite soil samples exceeded the US EPA limit for bare soil in play areas. Lead concentrations in samples collected in locations outside the study area did not exceed the limit. The highest concentration was in the plot closest to the smelter and may represent residual impact from the former smelter. Statistically significant relationships were not detected between interior floor dust lead loading and either interior paint lead loading or exterior dust lead concentration. Thus, no significant exposure from the former smelter was indicated by these analyses. This may have resulted from the time elapsed since the closing of the smelter and/or the relatively low paint lead levels. Further study is needed in other areas of Egypt near former and active lead smelters. Elevated levels of mercury and arsenic detected in soil samples do not appear to be related to the smelter

  13. High-resolution X-ray spectroscopy of Theta Car

    CERN Document Server

    Naze, Yael

    2008-01-01

    Context : The peculiar hot star Theta Car in the open cluster IC2602 is a blue straggler as well as a single-line binary of short period (2.2d). Aims : Its high-energy properties are not well known, though X-rays can provide useful constraints on the energetic processes at work in binaries as well as in peculiar, single objects. Methods : We present the analysis of a 50ks exposure taken with the XMM-Newton observatory. It provides medium as well as high-resolution spectroscopy. Results : Our high-resolution spectroscopy analysis reveals a very soft spectrum with multiple temperature components (1--6MK) and an X-ray flux slightly below the `canonical' value (log[L_X(0.1-10.)/L_{BOL}] ~ -7). The X-ray lines appear surprisingly narrow and unshifted, reminiscent of those of beta Cru and tau Sco. Their relative intensities confirm the anomalous abundances detected in the optical domain (C strongly depleted, N strongly enriched, O slightly depleted). In addition, the X-ray data favor a slight depletion in neon and ...

  14. KD901G X-ray system to reject contaminants

    International Nuclear Information System (INIS)

    Among the complaints to the foods that consumers bought, the proportion of the mixing of alien substances is more than 20%. The number of the cases classified by the kinds of alien substances, and that of minerals and animal substances are shown. The causes of the mixing of alien substances are classified into those due to the mixing in raw materials, production places, processing machines and workers. In case of using primary products as raw materials, the alien substances closely related to those raw materials are difficult to detect, such as bones and hairs in animal meat, fish bones, egg shells and fruit seeds. There are problems and limitation in the inspection of alien substance mixing by visual or touching inspection, metal detectors and the visual inspection of X-ray radiographs. The judgement of the presence of alien substances by automatically processing X-ray radiograph information has been tried one or two-dimensionally. The X-ray alien substance detector KD901G adopted the one-dimensional line sensor type, and its features are shown. The effective introduction of the X-ray alien substance detector, its comparison with metal detectors, and the safety of workers against radiation exposure and the safety of inspected foods are discussed. (K.I.)

  15. The Swift-BAT Hard X-Ray Transient Monitor

    Science.gov (United States)

    Krimm, H. A.; Holland, S. T.; Corbet, R. H. D.; Pearlman, A. B.; Romano, P.; Kennea, J. A.; Bloom, J. S.; Barthelmy, S. D.; Baumgartner, W. H.; Cummings, J. R.; Gehrels, N.; Lien, A. Y.; Markwardt, C. B.; Palmer, D. M.; Sakamoto, T.; Stamatikos, M.; Ukwatta, T. N.

    2013-01-01

    The Swift/Burst Alert Telescope (BAT) hard X-ray transient monitor provides near real-time coverage of the X-ray sky in the energy range 15-50 keV. The BAT observes 88% of the sky each day with a detection sensitivity of 5.3 mCrab for a full-day observation and a time resolution as fine as 64 s. The three main purposes of the monitor are (1) the discovery of new transient X-ray sources, (2) the detection of outbursts or other changes in the flux of known X-ray sources, and (3) the generation of light curves of more than 900 sources spanning over eight years. The primary interface for the BAT transient monitor is a public Web site. Between 2005 February 12 and 2013 April 30, 245 sources have been detected in the monitor, 146 of them persistent and 99 detected only in outburst. Among these sources, 17 were previously unknown and were discovered in the transient monitor. In this paper, we discuss the methodology and the data processing and filtering for the BAT transient monitor and review its sensitivity and exposure.We provide a summary of the source detections and classify them according to the variability of their light curves. Finally, we review all new BAT monitor discoveries. For the new sources that are previously unpublished, we present basic data analysis and interpretations.

  16. The Swift/BAT Hard X-ray Transient Monitor

    Science.gov (United States)

    Krimm, H. A.; Holland, S. T.; Corbet, R.H.D.; Pearlman, A. B.; Romano, P.; Kennea, J. A.; Bloom, J. S.; Barthelmy, S. D.; Baumgartner, W. H.; Cummings, J. R.; Gehrels, N.; Lien, A. Y.; Markwardt, C. B.; Palmer, D. M.; Sakamoto, T.; Stamatikos, M.; Ukwatta, N.

    2013-01-01

    The Swift/Burst Alert Telescope (BAT) hard X-ray transient monitor provides near real-time coverage of the X-ray sky in the energy range 15-50 keV. The BAT observes 88% of the sky each day with a detection sensitivity of 5.3 mCrab for a full-day observation and a time resolution as ne as 64 seconds. The three main purposes of the monitor are (1) the discovery of new transient X-ray sources, (2) the detection of outbursts or other changes in the ux of known X-ray sources, and (3) the generation of light curves of more than 900 sources spanning over eight years. The primary interface for the BAT transient monitor is a public web page. Since 2005 February, 242 sources have been detected in the monitor, 149 of them persistent and 93 detected only in outburst. Among these sources, 16 were previously unknown and discovered in the transient monitor. In this paper, we discuss the methodology and the data processing and ltering for the BAT transient monitor and review its sensitivity and exposure. We provide a summary of the source detections and classify them according to the variability of their light curves. Finally, we review all new BAT monitor discoveries and present basic data analysis and interpretations for those sources with previously unpublished results.

  17. The EINSTEIN Observatory Detection of Faint X-Ray Flashes

    CERN Document Server

    Gotthelf, E V; Helfand, D J

    1996-01-01

    We report on the result of an extensive search for X-ray counterparts to Gamma Ray Bursts (GRB) using data acquired with the Imaging Proportional Counter (IPC) on-board the Einstein Observatory. We examine background sky fields from all pointed observations for short timescale (~10 sec) transient X-ray phenomena not associated a-priori with detectable point sources. A total of 1.5 X 10^7 seconds of exposure time was searched on arc-minute spatial scales down to a limiting sensitivity of 10^-11 erg/cm^2/sec in the 0.2-3.5 keV IPC band. Forty-two highly significant X-ray flashes (Poisson probability < 10^-7 of being produced by statistical fluctuations) are discovered, of which eighteen have spectra consistent with an extragalactic origin and lightcurves similar to the Ginga-detected X-ray counterparts to GRB. Great care is taken to identify and exclude instrumental and observational artifacts; we develop a set of tests to cull events which may be associated with spacecraft or near-Earth space backgrounds. T...

  18. [X-ray diagnostic of partial intestinal obstruction in small intestine diseases: a glance on the problem of radiologist-gastroenterologist].

    Science.gov (United States)

    Levchenko, S V; Kotovshchikova, A A; Orlova, N V

    2013-01-01

    The article is devoted to special features of X-ray examining of patients suffering from acute abdomen pain and X-ray paradigma of some intestine diseases as a cause of partial bowel obstruction. Own clinical data are presented. Long-term experience of our X-ray department is summarized. The possibilities of X-ray examining of abdomen with and without contrast in patients with partial bowel obstruction are described. PMID:24772872

  19. [X-ray diagnostic of partial intestinal obstruction in small intestine diseases: a glance on the problem of radiologist-gastroenterologist].

    Science.gov (United States)

    Levchenko, S V; Kotovshchikova, A A; Orlova, N V

    2013-01-01

    The article is devoted to special features of X-ray examining of patients suffering from acute abdomen pain and X-ray paradigma of some intestine diseases as a cause of partial bowel obstruction. Own clinical data are presented. Long-term experience of our X-ray department is summarized. The possibilities of X-ray examining of abdomen with and without contrast in patients with partial bowel obstruction are described.

  20. Characterization of the adaptive response to ionizing radiation induced by low doses of X-rays to Vibrio cholerae cells

    International Nuclear Information System (INIS)

    Pretreatment with sublethal doses of X-rays induced an adaptive response in Vibrio cholerae cells as indicated by their greater resistance to the subsequent challenging doses of X-irradiation. The adaptive response was maximum following a pre-exposure dose of 1.7 Gy X-rays and an optimum incubation period of 40 min at 37C. Pre-exposure to a sublethal dose of 1.7 Gy X-rays made the Vibrio cholerae cells 3.38-fold more resistant to the subsequent challenge by X-rays. Pretreatment with a sublethal dose of hydrogen peroxide offered a similar degree of protection to the bacterial cells against subsequent treatment with challenging doses of X-ray radiation. However, exposure of Vibrio cholerae cells to mild heat (42C for 10 min) before X-ray irradiation decreased their survival following X-irradiation

  1. Energy dependence measurement of small-type optically stimulated luminescence (OSL) dosimeter by means of characteristic X-rays induced with general diagnostic X-ray equipment.

    Science.gov (United States)

    Takegami, Kazuki; Hayashi, Hiroaki; Okino, Hiroki; Kimoto, Natsumi; Maehata, Itsumi; Kanazawa, Yuki; Okazaki, Tohru; Hashizume, Takuya; Kobayashi, Ikuo

    2016-01-01

    For X-ray inspections by way of general X-ray equipment, it is important to measure an entrance-skin dose. Recently, a small optically stimulated luminescence (OSL) dosimeter was made commercially available by Landauer, Inc. The dosimeter does not interfere with the medical images; therefore, it is expected to be a convenient detector for measuring personal exposure doses. In an actual clinical situation, it is assumed that X-rays of different energies will be detected by a dosimeter. For evaluation of the exposure dose measured by a dosimeter, it is necessary to know the energy dependence of the dosimeter. Our aim in this study was to measure the energy dependence of the OSL dosimeter experimentally in the diagnostic X-ray region. Metal samples weighing several grams were irradiated and, in this way, characteristic X-rays having energies ranging from 8 to 85 keV were generated. Using these mono-energetic X-rays, the dosimeter was irradiated. Simultaneously, the fluence of the X-rays was determined with a CdTe detector. The energy-dependent efficiency of the dosimeter was derived from the measured value of the dosimeter and the fluence. Moreover, the energy-dependent efficiency was calculated by Monte-Carlo simulation. The efficiency obtained in the experiment was in good agreement with that of the simulation. In conclusion, our proposed method, in which characteristic X-rays are used, is valuable for measurement of the energy dependence of a small OSL dosimeter in the diagnostic X-ray region. PMID:26589210

  2. Energy dependence measurement of small-type optically stimulated luminescence (OSL) dosimeter by means of characteristic X-rays induced with general diagnostic X-ray equipment.

    Science.gov (United States)

    Takegami, Kazuki; Hayashi, Hiroaki; Okino, Hiroki; Kimoto, Natsumi; Maehata, Itsumi; Kanazawa, Yuki; Okazaki, Tohru; Hashizume, Takuya; Kobayashi, Ikuo

    2016-01-01

    For X-ray inspections by way of general X-ray equipment, it is important to measure an entrance-skin dose. Recently, a small optically stimulated luminescence (OSL) dosimeter was made commercially available by Landauer, Inc. The dosimeter does not interfere with the medical images; therefore, it is expected to be a convenient detector for measuring personal exposure doses. In an actual clinical situation, it is assumed that X-rays of different energies will be detected by a dosimeter. For evaluation of the exposure dose measured by a dosimeter, it is necessary to know the energy dependence of the dosimeter. Our aim in this study was to measure the energy dependence of the OSL dosimeter experimentally in the diagnostic X-ray region. Metal samples weighing several grams were irradiated and, in this way, characteristic X-rays having energies ranging from 8 to 85 keV were generated. Using these mono-energetic X-rays, the dosimeter was irradiated. Simultaneously, the fluence of the X-rays was determined with a CdTe detector. The energy-dependent efficiency of the dosimeter was derived from the measured value of the dosimeter and the fluence. Moreover, the energy-dependent efficiency was calculated by Monte-Carlo simulation. The efficiency obtained in the experiment was in good agreement with that of the simulation. In conclusion, our proposed method, in which characteristic X-rays are used, is valuable for measurement of the energy dependence of a small OSL dosimeter in the diagnostic X-ray region.

  3. Dual-energy X-ray CT and the extension to polychromatic X-ray CT

    International Nuclear Information System (INIS)

    We have developed dual energy X-ray CT using monochromatic X-ray beams. From the dual-energy X-ray CT, we can obtain distributions of an electron density and an effective atomic number in a human body. Especially, the electron density is very important for the heavy ion radiotherapy. Now, we adopted new array-detector to know the energy of incident photons as well as detect the position and the number of photons. We carry out the experiment of the dual-energy X-ray CT at the beamline of KEK and SPring-8 as a fundamental study for the polychromatic X-ray CT. We will show the preliminary result of this experiments and the feasibility of a quantitative polychromatic X-ray CT as an advanced method of monochromatic X-ray CT in this study. (author)

  4. Toward Adaptive X-Ray Telescopes

    Science.gov (United States)

    O'Dell, Stephen L.; Atkins, Carolyn; Button, Tim W.; Cotroneo, Vincenzo; Davis, William N.; Doel, Peer; Feldman, Charlotte H.; Freeman, Mark D.; Gubarev, Mikhail V.; Kolodziejczak, Jeffrey J.; Michette, Alan G.; Ramsey, Brian D.; Reid, Paul B.; Rodriguez Sanmartin, Daniel; Saha, Timo T.; Schwartz, Daniel A.; Trolier-McKinstry, Susan; Wilke, Rudeger H. T.; Willingale, Richard; Zhang, William W.

    2011-01-01

    Future x-ray observatories will require high-resolution (less than 1 inch) optics with very-large-aperture (greater than 25 square meter) areas. Even with the next generation of heavy-lift launch vehicles, launch-mass constraints and aperture-area requirements will limit the surface areal density of the grazing-incidence mirrors to about 1 kilogram per square meter or less. Achieving sub-arcsecond x-ray imaging with such lightweight mirrors will require excellent mirror surfaces, precise and stable alignment, and exceptional stiffness or deformation compensation. Attaining and maintaining alignment and figure control will likely involve adaptive (in-space adjustable) x-ray optics. In contrast with infrared and visible astronomy, adaptive optics for x-ray astronomy is in its infancy. In the middle of the past decade, two efforts began to advance technologies for adaptive x-ray telescopes: The Generation-X (Gen-X) concept studies in the United States, and the Smart X-ray Optics (SXO) Basic Technology project in the United Kingdom. This paper discusses relevant technological issues and summarizes progress toward adaptive x-ray telescopes.

  5. Toward active x-ray telescopes

    Science.gov (United States)

    O'Dell, Stephen L.; Atkins, Carolyn; Button, Timothy W.; Cotroneo, Vincenzo; Davis, William N.; Doel, Peter; Feldman, Charlotte H.; Freeman, Mark D.; Gubarev, Mikhail V.; Kolodziejczak, Jeffery J.; Michette, Alan G.; Ramsey, Brian D.; Reid, Paul B.; Rodriguez Sanmartin, Daniel; Saha, Timo T.; Schwartz, Daniel A.; Trolier-McKinstry, Susan; Wilke, Rudeger H. T.; Willingale, Richard; Zhang, William W.

    2011-09-01

    Future x-ray observatories will require high-resolution ( 25 m2) areas. Even with the next generation of heavy-lift launch vehicles, launch-mass constraints and aperture-area requirements will limit the areal density of the grazing-incidence mirrors to about 1 kg/m2 or less. Achieving sub-arcsecond x-ray imaging with such lightweight mirrors will require excellent mirror surfaces, precise and stable alignment, and exceptional stiffness or deformation compensation. Attaining and maintaining alignment and figure control will likely involve active (in-space adjustable) x-ray optics. In contrast with infrared and visible astronomy, active optics for x-ray astronomy is in its infancy. In the middle of the past decade, two efforts began to advance technologies for adaptive x-ray telescopes: The Smart X-ray Optics (SXO) Basic Technology project in the United Kingdom (UK) and the Generation-X (Gen-X) concept studies in the United States (US). This paper discusses relevant technological issues and summarizes progress toward active x-ray telescopes.

  6. MRI前瞻性研究在急性腕关节损伤患者X片阴性中的应用研究%MRI in X-ray-negative patients with acute carpal joint injury

    Institute of Scientific and Technical Information of China (English)

    张庆生

    2016-01-01

    Objective To study the magnetic resonance imaging (MR[) in patients with acute wrist injury whose X-ray was negative.Methods 155 patients treated at the department of orthopedics of our hospital from January,2012 to October,2014 were selected.Among which,85 were male and 70 female.Their average age was 28.There were two kinds of injury mechanism:low energy damage (wrist joint injury by placing wrists on floor from standing or lower height) and high energy damage (wrist joint injury caused by standing position or certain high intensity exercise).All the patients were examined by X-ray and MRI.Results 80% female and 38% male injured placing wrist joint on floor,with a statistical difference (P < 0.05).There was no statistical difference between high and low energy damage (P > 0.05).25 patients had negative MRI.The other 130 patients (83.37%) had 303 abnormal manifestations,including 54 cases of fracture,56 bone contusion,15 TFCC injury,and 5 scapholunate ligaments injury.According to the treatment strategy,most patients had received conservative treatment and achieved good results.7 patients with TFCC or SL injury needed further treatment;among which 2 patients underwent surgical treatment in order to reconstruct the TFCC ligament.Conclusions MRI should be considered as a part of early investigation,especially when the pain in the wrist joint was diagnosed in the first weeks.%目的 前瞻性研究X片阴性的急性腕关节损伤患者磁共振成像(MRI).方法 所有患者均来自于本院骨科,受试者入选时间2012年1月至2014年10月.共155例患者纳入研究,其中男85例,女70例,平均年龄28岁.受伤机制分为两类:低能量损伤(从站立或者更低的高度处摔倒手腕部撑地而损伤腕关节)和高能量损伤(人体站立位高度或者是某些高强度运动中造成的腕关节损伤).对所有患者进行标准的X片拍摄和MRI检查.结果 80%女性和38%男性在腕关节撑地后出现外

  7. The upper limits of the SNR in radiography and CT with polyenergetic x-rays.

    Science.gov (United States)

    Shikhaliev, Polad M

    2010-09-21

    The aim of the study is to determine the upper limits of the signal-to-noise ratio (SNR) in radiography and computed tomography (CT) with polyenergetic x-ray sources. In x-ray imaging, monoenergetic x-rays provide a higher SNR compared to polyenergetic x-rays. However, the SNR in polyenergetic x-ray imaging can be increased when a photon-counting detector is used and x-rays are optimally weighted according to their energies. For a particular contrast/background combination and at a fixed x-ray entrance skin exposure, the SNR in energy-weighting x-ray imaging depends on tube voltage and can be maximized by selecting the optimal tube voltage. The SNR in energy-weighted x-ray images acquired at this optimal tube voltage is the highest SNR that can be achieved with polyenergetic x-ray sources. The optimal tube voltages and the highest SNR were calculated and compared to the SNR of monoenergetic x-ray imaging. Monoenergetic, energy-weighting polyenergetic and energy-integrating polyenergetic x-ray imagings were simulated at a fixed entrance skin exposure of 20 mR. The tube voltages varied in the range of 30-140 kVp with 10 kV steps. Contrast elements of CaCO(3), iodine, adipose and tumor with thicknesses of 280 mg cm(-2), 15 mg cm(-2), 1 g cm(-2) and 1 g cm(-2), respectively, inserted in a soft tissue background with 10 cm and 20 cm thicknesses, were used. The energy weighting also improves the contrast-to-noise ratio (CNR) in CT when monoenergetic CT projections are optimally weighted prior to CT reconstruction (projection-based weighting). Alternatively, monoenergetic CT images are reconstructed, optimally weighted and composed to yield a final CT image (image-based weighting). Both projection-based and image-based weighting methods improve the CNR in CT. An analytical approach was used to determine which of these two weighting methods provides the upper limit of the CNR in CT. The energy-weighting method was generalized and expanded as a weighting method applicable

  8. Radiation safety and quality in diagnostic x-ray imaging 2001; Saeteilyturvallisuus ja laatu roentgendiagnostiikassa 2001

    Energy Technology Data Exchange (ETDEWEB)

    Servomaa, A.; Parviainen, T. (eds.)

    2001-05-01

    The obligations of the medical exposure directive (97/43/Euratom) for hospitals dominate the current activities in radiation protection in medical radiology. The directive gives special emphasis to radiation exposure of children, to examinations with high radiation doses and to radiation exposure in health screening programmes. The most important examinations with high doses are radiological interventions, where even acute skin effects are possible, and the computed tomography where the number of CT examinations makes only about 5% from the total number of x-ray examinations but the collective effective dose about 40% from the combined collective effective dose of all x-ray examinations. In the research projects financed by the European Commission, radiation exposures to paediatric patients have been measured in radiography, fluoroscopy and CT, and various dose assessment methods have been compared to develop a method for national follow-up of patients' radiation dose. The newest research project is focused on dosimetry and quality assurance in interventional radiology and digital imaging. Other actual topics are the development of radiation protection regulations and quality systems, education and training programmes, and clinical audits. This report deals with new radiation protection guides and recommendations and the education and training of radiological staff in radiation protection. One important topic is the development of national follow-up method of radiation exposure to patients and comparison of various dose assessment methods. Quality assurance in health care and in paediatric radiology, and the acceptance test and quality assurance measurements of radiological equipment are also described. (orig.)

  9. Two-dimensional x-ray diffraction

    CERN Document Server

    He, Bob B

    2009-01-01

    Written by one of the pioneers of 2D X-Ray Diffraction, this useful guide covers the fundamentals, experimental methods and applications of two-dimensional x-ray diffraction, including geometry convention, x-ray source and optics, two-dimensional detectors, diffraction data interpretation, and configurations for various applications, such as phase identification, texture, stress, microstructure analysis, crystallinity, thin film analysis and combinatorial screening. Experimental examples in materials research, pharmaceuticals, and forensics are also given. This presents a key resource to resea

  10. Imaging Cellular Architecture with X-rays

    OpenAIRE

    Larabell, Carolyn A.; Nugent, Keith A.

    2010-01-01

    X-ray imaging of biological samples is progressing rapidly. In this paper we review the progress to date in high resolution imaging of cellular architecture. In particular we survey the progress in soft X-ray tomography and argue that the field is coming of age and that important biological insights are starting to emerge. We then review the new ideas based on coherent diffraction. These methods are at a much earlier stage of development but, as they eliminate the need for X-ray optics, have ...

  11. The Future of X-Ray Optics

    Science.gov (United States)

    Weisskopf, Martin C.

    2013-01-01

    The most important next step is the development of X-ray optics comparable to (or better than) Chandra in angular resolution that far exceed Chandra s effective area. Use the long delay to establish an adequately funded, competitive technology program along the lines I have recommended. Don't be diverted from this objective, except for Explorer-class missions. Progress in X-ray optics, with emphasis on the angular resolution, is central to the paradigm-shifting discoveries and the contributions of X-ray astronomy to multiwavelength astrophysics over the past 51 years.

  12. Ten years of X-ray interferometry

    International Nuclear Information System (INIS)

    X-ray interferometers were the first optical instruments which utilized many Bragg reflecting components in monolithic blocks of perfect crystal. They have made important contributions to our knowledge of fundamental constants, of Bragg reflection x-ray optics, of strains and defects in crystals and of the optical constants of materials in the x-ray region of the electromagnetic spectrum. Based on an oversimplified optical analogue, their mode of operation is described in detail. Current applications of crystal interferometers and future work is briefly reviewed. (author)

  13. X-ray phase-contrast methods

    Energy Technology Data Exchange (ETDEWEB)

    Lider, V. V., E-mail: lider@ns.crys.ras.ru; Kovalchuk, M. V. [Russian Academy of Sciences, Shubnikov Institute of Crystallography (Russian Federation)

    2013-11-15

    This review is devoted to a comparative description of the methods for forming X-ray phase-contrast images of weakly absorbing (phase) objects. These include the crystal interferometer method, the Talbot interferometer method, diffraction-enhanced X-ray imaging, and the in-line method. The potential of their practical application in various fields of science and technology is discussed. The publications on the development and optimization of X-ray phase-contrast methods and the experimental study of phase objects are analyzed.

  14. Microfabrication of hard x-ray lenses

    DEFF Research Database (Denmark)

    Stöhr, Frederik

    in the vertical and horizontal directions was addressed. A functioning prototype of a 2D silicon objective for use in a bright-field hard-XRM was demonstrated. The results are promising; showing acceptably low aberration and performance close to theoretical expectations. A resolution of 300 nm with 17 keV x...... rate larger than 10 pieces per hour indicates the economic value of injection molded x-ray lenses, which may have applications in more readily available small laboratory x-ray instruments or medical devices. In each case, observed non-uniformities of the shaped x-ray beams were investigated and found...

  15. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... assist in the detection and diagnosis of bone cancer . locate foreign objects in soft tissues around or ... Risks There is always a slight chance of cancer from excessive exposure to radiation. However, the benefit ...

  16. Lead foil in dental X-ray film: Backscattering rejection or image intensifier?

    Energy Technology Data Exchange (ETDEWEB)

    Hönnicke, M.G., E-mail: marcelo.honnicke@unila.edu.br [Universidade Federal da Integração Latino-Americana, Foz do Iguaçu (Brazil); Delben, G.J. [Faculdade de Tecnologia Tupy, Curitiba (Brazil); Godoi, W.C. [Universidade Tecnológica Federal do Paraná, Curitiba (Brazil); Swinka-Filho, V. [Instituto de Tecnologia para o Desenvolvimento – LACTEC, Curitiba (Brazil)

    2014-11-01

    Dental X-ray films are still largely used due to sterilization issues, simplicity and, mainly, economic reasons. These films almost always are double coated (double emulsion) and have a lead foil in contact with the film for X-ray backscattering rejection. Herein we explore the use of the lead foil as an image intensifier. In these studies, spatial resolution was investigated when images were acquired on the dental X-ray films with and without the lead foil. Also, the lead foil was subjected to atomic analysis (fluorescent measurements) and structure analysis (X-ray diffraction). We determined that the use of the lead foil reduces the exposure time, however, does not affect the spatial resolution on the acquired images. This suggests that the fluorescent radiation spread is smaller than the grain sizes of the dental X-ray films.

  17. Radiation-induced thumbs carcinoma due to practicing dental X-ray

    Directory of Open Access Journals (Sweden)

    Esam S Halboub

    2015-01-01

    Full Text Available Dealing with diagnostic X-ray radiation may result in serious health problems, unless protection guidelines are followed. This became prevalent immediately a decade following the invention of X-ray radiation, where it had not been known that the accumulative exposure to X-ray radiation may carry huge health hazards. The reoccurrence of various fatal cancer cases compelled the concerned health authorities to develop safety standards to be followed by all X-ray clinics and technicians worldwide. This report documents the clinical case of a dental radiographer, who developed thumbs carcinoma after 15 years of practicing the profession, most likely due to his neglect of the X-ray radiation protection guidelines.

  18. Flux monitoring hard X-ray optics in a single electrode configuration

    CERN Document Server

    Stoupin, Stanislav; Katsoudas, John

    2014-01-01

    To explore possibilities for X-ray flux monitoring on optical elements electrical responses of silicon and diamond single crystals and that of an X-ray mirror were studied under exposure to hard X-rays in a single electrode configuration in ambient air. To introduce flux monitoring as a non-invasive capability a platinum electrode was deposited on a small unexposed portion of the entrance surface of the crystals while for the X-ray mirror the entire mirror surface served as an electrode. It was found that the electrical responses are affected by photoemission and photoionization of the surrounding air. The influence of these factors was quantified using estimations of total electron yield and the ionization current. It is shown that both phenomena can be used for the non-invasive monitoring of hard X-ray flux on the optical elements. Relevant limits of applicability such as detection sensitivity and charge collection efficiency are identified and discussed.

  19. Lead foil in dental X-ray film: Backscattering rejection or image intensifier?

    International Nuclear Information System (INIS)

    Dental X-ray films are still largely used due to sterilization issues, simplicity and, mainly, economic reasons. These films almost always are double coated (double emulsion) and have a lead foil in contact with the film for X-ray backscattering rejection. Herein we explore the use of the lead foil as an image intensifier. In these studies, spatial resolution was investigated when images were acquired on the dental X-ray films with and without the lead foil. Also, the lead foil was subjected to atomic analysis (fluorescent measurements) and structure analysis (X-ray diffraction). We determined that the use of the lead foil reduces the exposure time, however, does not affect the spatial resolution on the acquired images. This suggests that the fluorescent radiation spread is smaller than the grain sizes of the dental X-ray films

  20. Abreu system - A dosimetric system to evaluate basic parameters of photofluorographic X-ray machine

    International Nuclear Information System (INIS)

    In Brazil, photofluorographic X-ray machines are used for cuberculosis mass screening throughout the country. The exact number of these X-ray equipment is unknown but it is estimated to be around 1000 operating units. Twelve million miniature chest radiographs are taken per year. In order to make local inspections speedier and also aiming at its postal use, a system has been developed wich evaluates the entrace exposure of the patient, the X-ray beam half-value layer ( leading to the evaluation of the tube's total filtration ) and the beam's field size. It consists of a piece of cardboard where filters, TLDs and X-ray films are inserted. So far the system has been tested in 53 X-ray machines in Rio de Janeiro. The results show that it can be used in a national survey program. (Author)

  1. Asbestos-related x-ray changes in foundry workers.

    Science.gov (United States)

    Rosenman, K D; Reilly, M J

    1998-08-01

    Michigan has a statewide mandatory occupational disease reporting system. As part of that system, reports are received from hospital, physicians, death certificates, the worker's compensation bureau, and company medical departments. Based on this reporting, the State of Michigan has a special emphasis program for the surveillance of silicosis, a known disease outcome among foundry workers. From 1985-1996, 115 cases reported to the State Surveillance System as silicosis, pneumoconiosis not specified, or pulmonary fibrosis were reclassified as having asbestos related x-ray changes after a B-reader interpretation of each case's chest x-ray. During this same period there were an additional 697 reports confirmed as silicosis and 6,724 cases reported to the surveillance system as asbestosis. Among the 115 reports reclassified as having asbestos-related x-ray changes without evidence of silicosis-related x-ray changes, 54 had worked in foundries. Only 7 (14.8%) of these individuals had their primary work in maintenance in the foundry; 40 (85.1%) had their primary foundry work in a production job; and for 10 individuals the occupation was not known. Asbestos has been used in foundries on pipe laggings, boiler coverings, as insulation in fan housings, in gloves, aprons and curtains, as insulation in cupolas, and in ladles and insulation in sand molds. Clinicians caring for foundry workers need to be aware that asbestos-related x-ray changes are not uncommon in this population and asbestos exposure should be considered as one of the carcinogens contributing to the known increased risk of lung cancer among foundry workers. PMID:9651631

  2. Chest x-ray quality in the diagnosis of pneumonia in children: From prescription to optimization

    International Nuclear Information System (INIS)

    Acute lower respiratory tract infection (ALRI), primarily pneumonia, is the leading cause of childhood death in developing countries. The increasing incidence of antimicrobial resistance and the high cost of vaccines lead to considering the first strategy to reduce pneumonia deaths the early detection of the disease. Case management begins with the clinical examination and may continue with the prescription of a chest x-ray. Consequently, the radiograph should meet quality standards, and radiologists and paediatricians must know how to interpret the images. Special attention should be paid on patient dose due to children radiosensitivity, high frequency and chest x rays rejection rate. This paper is a retrospective study of chest radiographs performed in 5731 children with clinical diagnosis of ALRI assisted in three Uruguayan hospitals during the three year investigation supported by the Division of Vaccines and Immunization of the Pan American Health Organization (PAHO) that had the aim of estimating the burden of pneumonia (from 2001 to 2004). It is analyzed the prescription of radiographs during the diagnosis and in later controls (2220 children assisted in two of the three hospitals). Patient doses are estimated from technical parameters and equipment specifications. The investigation also analyzes patient doses that could have been avoided if paediatricians had managed the disease according to the established protocols. Results show that 82.4 % of chest x-rays diagnosed pneumonia and that some children underwent up to ten radiographs. Significant differences were found in patient dose in the three hospitals, concluding that education on image quality on chest radiographs of radiologists, paediatricians and radiological technologists is the first and best tool for the earlier diagnosis of pneumonia in children and for the application of Radiation Protection (RP) principles in medical exposures. (author)

  3. Chest X-ray quality in the diagnosis of pneumonia in children: from prescription to optimization

    International Nuclear Information System (INIS)

    Acute lower respiratory tract infection (ALRI), primarily pneumonia, is the leading cause of childhood death in developing countries. The increasing incidence of antimicrobial resistance and the high cost of vaccines lead to considering the first strategy to reduce pneumonia deaths the early detection of the disease. Case management begins with the clinical examination and may continue with the prescription of a chest x-ray. Consequently, the radiograph should meet quality standards, and radiologists and paediatricians must know how to interpret the images. Special attention should be paid on patient dose due to children radiosensitivity, high frequency and chest x rays rejection rate. This paper is a retrospective study of chest radiographs performed in 5731 children with clinical diagnosis of ALRI assisted in three Uruguayan hospitals during the three year investigation supported by the Division of Vaccines and Immunization of the Pan American Health Organization (PAHO) that had the aim of estimating the burden of pneumonia (from 2001 to 2004). It is analyzed the prescription of radiographs during the diagnosis and in later controls (2220 children assisted in two of the three hospitals). Patient doses are estimated from technical parameters and equipment specifications. The investigation also analyzes patient doses that could have been avoided if paediatricians had managed the disease according to the established protocols. Results show that 82.4 % of chest X-rays diagnosed pneumonia and that some children underwent up to ten radiographs. Significant differences were found in patient dose in the three hospitals, concluding that education on image quality on chest radiographs of radiologists, paediatricians and radiological technologists is the first and best tool for the earlier diagnosis of pneumonia in children and for the application of Radiation Protection (RP) principles in medical exposures. (author)

  4. Laser plasma x-ray source for ultrafast time-resolved x-ray absorption spectroscopy.

    Science.gov (United States)

    Miaja-Avila, L; O'Neil, G C; Uhlig, J; Cromer, C L; Dowell, M L; Jimenez, R; Hoover, A S; Silverman, K L; Ullom, J N

    2015-03-01

    We describe a laser-driven x-ray plasma source designed for ultrafast x-ray absorption spectroscopy. The source is comprised of a 1 kHz, 20 W, femtosecond pulsed infrared laser and a water target. We present the x-ray spectra as a function of laser energy and pulse duration. Additionally, we investigate the plasma temperature and photon flux as we vary the laser energy. We obtain a 75 μm FWHM x-ray spot size, containing ∼10(6) photons/s, by focusing the produced x-rays with a polycapillary optic. Since the acquisition of x-ray absorption spectra requires the averaging of measurements from >10(7) laser pulses, we also present data on the source stability, including single pulse measurements of the x-ray yield and the x-ray spectral shape. In single pulse measurements, the x-ray flux has a measured standard deviation of 8%, where the laser pointing is the main cause of variability. Further, we show that the variability in x-ray spectral shape from single pulses is low, thus justifying the combining of x-rays obtained from different laser pulses into a single spectrum. Finally, we show a static x-ray absorption spectrum of a ferrioxalate solution as detected by a microcalorimeter array. Altogether, our results demonstrate that this water-jet based plasma source is a suitable candidate for laboratory-based time-resolved x-ray absorption spectroscopy experiments.

  5. Laser plasma x-ray source for ultrafast time-resolved x-ray absorption spectroscopy

    Directory of Open Access Journals (Sweden)

    L. Miaja-Avila

    2015-03-01

    Full Text Available We describe a laser-driven x-ray plasma source designed for ultrafast x-ray absorption spectroscopy. The source is comprised of a 1 kHz, 20 W, femtosecond pulsed infrared laser and a water target. We present the x-ray spectra as a function of laser energy and pulse duration. Additionally, we investigate the plasma temperature and photon flux as we vary the laser energy. We obtain a 75 μm FWHM x-ray spot size, containing ∼106 photons/s, by focusing the produced x-rays with a polycapillary optic. Since the acquisition of x-ray absorption spectra requires the averaging of measurements from >107 laser pulses, we also present data on the source stability, including single pulse measurements of the x-ray yield and the x-ray spectral shape. In single pulse measurements, the x-ray flux has a measured standard deviation of 8%, where the laser pointing is the main cause of variability. Further, we show that the variability in x-ray spectral shape from single pulses is low, thus justifying the combining of x-rays obtained from different laser pulses into a single spectrum. Finally, we show a static x-ray absorption spectrum of a ferrioxalate solution as detected by a microcalorimeter array. Altogether, our results demonstrate that this water-jet based plasma source is a suitable candidate for laboratory-based time-resolved x-ray absorption spectroscopy experiments.

  6. X-ray diffraction contrast tomography (DCT) system, and an X-ray diffraction contrast tomography (DCT) method

    DEFF Research Database (Denmark)

    2012-01-01

    Source: US2012008736A An X-ray diffraction contrast tomography system (DCT) comprising a laboratory X-ray source (2), a staging device (5) rotating a polycrystalline material sample in the direct path of the X-ray beam, a first X-ray detector (6) detecting the direct X-ray beam being transmitted...

  7. Future X-ray timing missions

    CERN Document Server

    Barret, D; Staubert, R; Stella, L

    2000-01-01

    Thanks to the Rossi X-ray Timing Explorer (RXTE), it is now widely recognized that fast X-ray timing can be used to probe strong gravity fields around collapsed objects and constrain the equation of state of dense matter in neutron stars. We first discuss some of the outstanding issues which could be solved with an X-ray timing mission building on the great successes of RXTE and providing an order of magnitude better sensitivity. Then we briefly describe the 'Experiment for X-ray timing and Relativistic Astrophysics' (EXTRA) recently proposed to the European Space Agency as a follow-up to RXTE and the related US mission 'Relativistic Astrophysics Explorer' (RAE).

  8. Future X-Ray Timing Missions

    Science.gov (United States)

    Barret, Didier; van der Klis, Michiel; Skinner, Gerry K.; Staubert, Rüdiger; Stella, Luigi

    Thanks to the Rossi X-ray Timing Explorer (RXTE), it is now widely recognized that fast X-ray timing can be used to probe strong gravity fields around collapsed objects and constrain the equation of state of dense matter in neutron stars. We first discuss some of the outstanding issues which could be solved with an X-ray timing mission building on the great successes of RXTE and providing an order of magnitude better sensitivity. Then we briefly describe the `Experiment for X-ray timing and Relativistic Astrophysics' (EXTRA) recently proposed to the European Space Agency as a follow-up to RXTE and the related US mission `Relativistic Astrophysics Explorer' (RAE).

  9. Experimental x-ray ghost imaging

    CERN Document Server

    Pelliccia, Daniele; Scheel, Mario; Cantelli, Valentina; Paganin, David M

    2016-01-01

    We report an experimental proof of principle for ghost imaging in the hard x-ray energy range. We used a synchrotron x-ray beam that was split using a thin crystal in Laue diffraction geometry. With an ultra-fast imaging camera, we were able to image x-rays generated by isolated electron bunches. At this time scale, the shot noise of the synchrotron emission process is measurable as speckles, leading to speckle correlation between the two beams. The integrated transmitted intensity from a sample located in the first beam was correlated with the spatially resolved intensity measured on the second, empty, beam to retrieve the shadow of the sample. The demonstration of ghost imaging with hard x-rays may open the way to protocols to reduce radiation damage in medical imaging and in non-destructive structural characterization using Free Electron Lasers.

  10. Experimental X-Ray Ghost Imaging

    Science.gov (United States)

    Pelliccia, Daniele; Rack, Alexander; Scheel, Mario; Cantelli, Valentina; Paganin, David M.

    2016-09-01

    We report an experimental proof of principle for ghost imaging in the hard-x-ray energy range. We use a synchrotron x-ray beam that is split using a thin crystal in Laue diffraction geometry. With an ultrafast imaging camera, we are able to image x rays generated by isolated electron bunches. At this time scale, the shot noise of the synchrotron emission process is measurable as speckles, leading to speckle correlation between the two beams. The integrated transmitted intensity from a sample located in the first beam is correlated with the spatially resolved intensity measured in the second, empty, beam to retrieve the shadow of the sample. The demonstration of ghost imaging with hard x rays may open the way to protocols to reduce radiation damage in medical imaging and in nondestructive structural characterization using free electron lasers.

  11. Center for X-ray Optics (CXRO)

    Data.gov (United States)

    Federal Laboratory Consortium — The Center for X-Ray Optics at Lawrence Berkeley National Laboratory works to further science and technology using short wavelength optical systems and techniques....

  12. Why Do I Need X-Rays?

    Science.gov (United States)

    ... information you need from the Academy of General Dentistry Wednesday, August 24, 2016 About | Contact InfoBites Quick ... Related Articles: X-Rays The Academy of General Dentistry (AGD) Sets the Record Straight on Dental X- ...

  13. X-Ray Technologist Listing In California

    Data.gov (United States)

    U.S. Department of Health & Human Services — This table represents a current listing of X-Ray Technologists who are licensed by Radiologic Health Branch (RHB) of the California Department of Public Health. RHB...

  14. X-ray source for mammography

    Science.gov (United States)

    Logan, Clinton M.

    1994-01-01

    An x-ray source utilizing anode material which shifts the output spectrum to higher energy and thereby obtains higher penetrating ability for screening mammography application, than the currently utilized anode material. The currently used anode material (molybdenum) produces an energy x-ray spectrum of 17.5/19.6 keV, which using the anode material of this invention (e.g. silver, rhodium, and tungsten) the x-ray spectrum would be in the 20-35 keV region. Thus, the anode material of this invention provides for imaging of breasts with higher than average x-ray opacity without increase of the radiation dose, and thus reduces the risk of induced breast cancer due to the radiation dose administered for mammograms.

  15. Tuberculosis, advanced - chest x-rays (image)

    Science.gov (United States)

    Tuberculosis is an infectious disease that causes inflammation, the formation of tubercules and other growths within tissue, ... death. These chest x-rays show advanced pulmonary tuberculosis. There are multiple light areas (opacities) of varying ...

  16. Chest X-Ray (Chest Radiography)

    Science.gov (United States)

    ... Lung tissue absorbs little radiation and will appear dark on the image. Until recently, x-ray images ... understanding of the possible charges you will incur. Web page review process: This Web page is reviewed ...

  17. X-ray microtomography in biology

    CERN Document Server

    Mizutani, Ryuta

    2016-01-01

    Progress in high-resolution x-ray microtomography has provided us with a practical approach to determining three-dimensional (3D) structures of opaque samples at micrometer to submicrometer resolution. In this review, we give an introduction to hard x-ray microtomography and its application to the visualization of 3D structures of biological soft tissues. Practical aspects of sample preparation, handling, data collection, 3D reconstruction, and structure analysis are described. Furthermore, different sample contrasting methods are approached in detail. Examples of microtomographic studies are overviewed to present an outline of biological applications of x-ray microtomography. We also provide perspectives of biological microtomography as the convergence of sciences in x-ray optics, biology, and structural analysis.

  18. X-ray imaging: Status and trends

    International Nuclear Information System (INIS)

    There is a veritable renaissance occurring in x-ray imaging. X-ray imaging by radiography has been a highly developed technology in medicine and industry for many years. However, high resolution imaging has not generally been practical because sources have been relatively dim and diffuse, optical elements have been nonexistent for most applications, and detectors have been slow and of low resolution. Materials analysis needs have therefore gone unmet. Rapid progress is now taking place because we are able to exploit developments in microelectronics and related material fabrication techniques, and because of the availability of intense x-ray sources. This report describes the methods and uses of x-ray imaging along with a discussion of technology advances in these areas

  19. 5.8 X-ray Calorimeters

    Science.gov (United States)

    Porter, F. Scott

    2008-01-01

    X-ray calorimeter instruments for astrophysics have seen rapid development since they were invented in 1984. The prime instrument on all currently planned X-ray spectroscopic observatories is based on calorimeter technology. This relatively simple detection concept that senses the energy of an incident photon by measuring the temperature rise of an absorber material at very low temperatures, can form the basis of a very high performance, non-dispersive spectrometer. State-of-the-art calorimeter instruments have resolving powers of over 3000, large simultaneous band-passes, and near unit efficiency. This coupled with the intrinsic imaging capability of a pixilated x-ray calorimeter array, allows true spectral-spatial instruments to be constructed. In this chapter I briefly review the detection scheme, the state-of-the-art in X-ray calorimeter instruments and the future outlook for this technology.

  20. Silicon Wafer X-ray Mirror Project

    Data.gov (United States)

    National Aeronautics and Space Administration — In this one year research project, we propose to do the following four tasks; (1) Design the silicon wafer X-ray mirror demo unit and develop a ray-tracing code to...

  1. Silicon Wafer X-ray Mirror Project

    Data.gov (United States)

    National Aeronautics and Space Administration — In this one year research project, we propose to do the following four tasks;(1) Design the silicon wafer X-ray mirror demo unit and develop a ray-tracing code to...

  2. Demonstration of X-ray talbot interferometry

    CERN Document Server

    Momose, A; Kawamoto, S; Hamaishi, Y; Takai, K; Suzuki, Y

    2003-01-01

    First Talbot interferometry in the hard X-ray region was demonstrated using a pair of transmission gratings made by forming gold stripes on glass plates. By aligning the gratings on the optical axis of X-rays with a separation that caused the Talbot effect by the first grating, moire fringes were produced inclining one grating slightly against the other around the optical axis. A phase object placed in front of the first grating was detected by moire-fringe bending. Using the technique of phase-shifting interferometry, the differential phase corresponding to the phase object could also be measured. This result suggests that X-ray Talbot interferometry is a novel and simple method for phase-sensitive X-ray radiography. (author)

  3. Resonant X-Ray Scattering and Absorption

    Science.gov (United States)

    Collins, S. P.; Bombardi, A.

    This chapter outlines some of the basic ideas behind nonresonant and resonant X-ray scattering, using classical or semiclassical pictures wherever possible; specifically, we highlight symmetry arguments governing the observation of X-ray optical effects, such as X-ray magnetic circular dichroism and resonant "forbidden" diffraction. Without dwelling on the microscopic physics that underlies resonant scattering, we outline some key steps required for calculating its rotation and polarization dependence, based on Cartesian and spherical tensor frameworks. Several examples of resonant scattering, involving electronic anisotropy and magnetism, are given as illustrations. Our goal is not to develop or defend theoretical concepts in X-ray scattering, but to bring together existing ideas in a pragmatic and utilitarian manner.

  4. Nonrelativistic quantum X-ray physics

    CERN Document Server

    Hau-Riege, Stefan P

    2015-01-01

    Providing a solid theoretical background in photon-matter interaction, Nonrelativistic Quantum X-Ray Physics enables readers to understand experiments performed at XFEL-facilities and x-ray synchrotrons. As a result, after reading this book, scientists and students will be able to outline and perform calculations of some important x-ray-matter interaction processes. Key features of the contents are that the scope reaches beyond the dipole approximation when necessary and that it includes short-pulse interactions. To aid the reader in this transition, some relevant examples are discussed in detail, while non-relativistic quantum electrodynamics help readers to obtain an in-depth understanding of the formalisms and processes. The text presupposes a basic (undergraduate-level) understanding of mechanics, electrodynamics, and quantum mechanics. However, more specialized concepts in these fields are introduced and the reader is directed to appropriate references. While primarily benefiting users of x-ray light-sou...

  5. Astrophysics: Unexpected X-ray flares

    Science.gov (United States)

    Campana, Sergio

    2016-10-01

    Two sources of highly energetic flares have been discovered in archival X-ray data of 70 nearby galaxies. These flares have an undetermined origin and might represent previously unknown astrophysical phenomena. See Letter p.356

  6. X-ray crystallographic studies of metalloproteins.

    Science.gov (United States)

    Volbeda, Anne

    2014-01-01

    Many proteins require metals for their physiological function. In combination with spectroscopic characterizations, X-ray crystallography is a very powerful method to correlate the function of protein-bound metal sites with their structure. Due to their special X-ray scattering properties, specific metals may be located in metalloprotein structures and eventually used for phasing the diffracted X-rays by the method of Multi-wavelength Anomalous Dispersion (MAD). How this is done is the principle subject of this chapter. Attention is also given to the crystallographic characterization of different oxidation states of redox active metals and to the complication of structural changes that may be induced by X-ray irradiation of protein crystals.

  7. Demonstration of X-ray talbot interferometry

    International Nuclear Information System (INIS)

    First Talbot interferometry in the hard X-ray region was demonstrated using a pair of transmission gratings made by forming gold stripes on glass plates. By aligning the gratings on the optical axis of X-rays with a separation that caused the Talbot effect by the first grating, moire fringes were produced inclining one grating slightly against the other around the optical axis. A phase object placed in front of the first grating was detected by moire-fringe bending. Using the technique of phase-shifting interferometry, the differential phase corresponding to the phase object could also be measured. This result suggests that X-ray Talbot interferometry is a novel and simple method for phase-sensitive X-ray radiography. (author)

  8. X-ray Emission from Solar Flares

    Indian Academy of Sciences (India)

    Rajmal Jain; Malini Aggarwal; Raghunandan Sharma

    2008-03-01

    Solar X-ray Spectrometer (SOXS), the first space-borne solar astronomy experiment of India was designed to improve our current understanding of X-ray emission from the Sun in general and solar flares in particular. SOXS mission is composed of two solid state detectors, viz., Si and CZT semiconductors capable of observing the full disk Sun in X-ray energy range of 4–56 keV. The X-ray spectra of solar flares obtained by the Si detector in the 4–25 keV range show evidence of Fe and Fe/Ni line emission and multi-thermal plasma. The evolution of the break energy point that separates the thermal and non-thermal processes reveals increase with increasing flare plasma temperature. Small scale flare activities observed by both the detectors are found to be suitable to heat the active region corona; however their location appears to be in the transition region.

  9. Inelastic magnetic X-ray scattering

    Science.gov (United States)

    Platzman, P. M.; Tzoar, N.

    1985-04-01

    The theory of magnetic X-ray scattering is used to discuss the possibilities for employing inelastic scattering to probe the magnetic properties of condensed matter systems. In particular, it is shown how the interference between the nonmagnetic (Compton) and magnetic scattering arising from the use of circularly polarized X-rays is absolutely essential in such experiments. The very beautiful preliminary experiments by Sakai and Ono (1976) on Fe which use circularly polarized Moessbauer gamma-rays will be discussed. They already show the sensitivity of the technique to the 'magnetic form factor'. In addition, the physics of a unique quarter wave plate employed in obtaining circularly polarized X-rays is considered, and the implications of this advance for doing such experiments on existing synchrotron X-ray sources are discussed.

  10. Capillary Optics generate stronger X-rays

    Science.gov (United States)

    1996-01-01

    NASA scientist, in the Space Sciences lab at Marshall, works with capillary optics that generate more intense X-rays than conventional sources. This capability is useful in studying the structure of important proteins.

  11. Insights from soft X-rays

    DEFF Research Database (Denmark)

    Raaf, Jennifer; Issinger, Olaf-Georg; Niefind, Karsten

    2008-01-01

    The diffraction pattern of a protein crystal is normally a product of the interference of electromagnetic waves scattered by electrons of the crystalline sample. The diffraction pattern undergoes systematic changes in case additionally X-ray absorption occurs, meaning if the wavelength of the pri......The diffraction pattern of a protein crystal is normally a product of the interference of electromagnetic waves scattered by electrons of the crystalline sample. The diffraction pattern undergoes systematic changes in case additionally X-ray absorption occurs, meaning if the wavelength...... of the primary X-ray beam is relatively close to the absorption edge of selected elements of the sample. The resulting effects are summarized as "anomalous dispersion" and can be always observed with "soft" X-rays (wavelength around 2 A) since they match the absorption edges of sulfur and chlorine...

  12. Dentistry 4. X-ray diagnostics

    International Nuclear Information System (INIS)

    DIN pocketbook 267/4 gives an overview of the normative requirements of the new X-Ray and Radiation Protection Ordinance, which has been in effect since 1 November 2011. This DIN pocketbook is intended for anyone charged with professional responsibility for the use of ionizing radiation in dentistry, operators and users of x-ray devices, radiation protection officers, accredited experts, manufacturers as well as for anyone with an interest in radiation protection or optimal radiological diagnostics. It contains standards relating to the following areas: acceptance and constancy testing; devices for evaluating findings (monitors, film viewing devices), films, printers; archiving, designating, labelling. Adherence to the standards makes it possible to avoid distractive artefacts in x-ray images and optimise the quality of x-ray diagnostics in dentistry.

  13. Linking Jet Emission, X-Ray States, and Hard X-Ray Tails in the Neutron Star X-Ray Binary GX 17+2

    NARCIS (Netherlands)

    S. Migliari; J.C.A. Miller-Jones; R.P. Fender; J. Homan; T. di Salvo; R.E. Rothschild; M.P. Rupen; J.A. Tomsick; R. Wijnands; M. van der Klis

    2007-01-01

    We present the results of simultaneous radio (VLA) and X-ray (RXTE) observations of the Z-type neutron star X-ray binary GX 17+2. The aim is to assess the coupling between X-ray and radio properties throughout its three rapidly variable X-ray states and during the time-resolved transitions. These ob

  14. Advanced detectors for X-ray microscopy

    International Nuclear Information System (INIS)

    Over the last decade the advances in x-ray microscopy have mainly been due to the development of x-ray source technology and to the micro-fabrication of x-ray optics. These advances have spurred the development of x-ray microscopes that are approaching the best resolution possible in the presence of radiation damage in the specimen. In addition, the development of specimen preparation techniques that reduce tile effects of radiation damage on the specimen are underway. In contrast, tile development or x-ray detectors for x-ray microscopy has been a low priority. The objective of the work was to develop a new detector for x-ray microscopy. This involved the modification of a Thorn EMI electron tube in order to sensitise the multiplier for soil x-rays In the energy range of interest (0.2-6 keV). The electron multiplier was then tested on a repetitive laser plasma source, which has been shown to be eminently suitable for a laboratory scale x-ray microscope, and the Scanning Transmission X-ray Microscope (STXM) at the National Synchrotron Light Source (NSLS), which is the most successful STXM presently in operation. The processed data from tile electron multiplier was used to characterise its response and assess its potential as all alternative to existing detectors. In addition, ID21, the microscopy beamline at the European Synchrotron Radiation Source (ESRF) was studied to assess the need for a beam position monitor close to the exit slit of the monochromator. This involved the ray tracing of the beamline. It was proposed that in the case of a crystal monochromator a beam position monitor based oil the total signal from a photo-emitting blade containing a number of different diameter pinholes was sufficient. However, for a grating monochromator tile beamline design relied upon feedback from a beam position monitor capable of detecting the height of the beam at tile entrance to the microscope. A number of conceptual designs for a monitor that could fulfil this

  15. Principles of X-ray Navigation

    Energy Technology Data Exchange (ETDEWEB)

    Hanson, John Eric; /SLAC

    2006-03-17

    X-ray navigation is a new concept in satellite navigation in which orientation, position and time are measured by observing stellar emissions in x-ray wavelengths. X-ray navigation offers the opportunity for a single instrument to be used to measure these parameters autonomously. Furthermore, this concept is not limited to missions in close proximity to the earth. X-ray navigation can be used on a variety of missions from satellites in low earth orbit to spacecraft on interplanetary missions. In 1997 the Unconventional Stellar Aspect Experiment (USA) will be launched as part of the Advanced Research and Global Observation Satellite (ARGOS). USA will provide the first platform for real-time experimentation in the field of x-ray navigation and also serves as an excellent case study for the design and manufacturing of space qualified systems in small, autonomous groups. Current techniques for determining the orientation of a satellite rely on observations of the earth, sun and stars in infrared, visible or ultraviolet wavelengths. It is possible to use x-ray imaging devices to provide arcsecond level measurement of attitude based on star patterns in the x-ray sky. This technique is explored with a simple simulation. Collimated x-ray detectors can be used on spinning satellites to provide a cheap and reliable measure of orientation. This is demonstrated using observations of the Crab Pulsar taken by the high Energy Astronomy Observatory (HEAO-1) in 1977. A single instrument concept is shown to be effective, but dependent on an a priori estimate of the guide star intensity and thus susceptible to errors in that estimate. A star scanner based on a differential measurement from two x-ray detectors eliminates the need for an a priori estimate of the guide star intensity. A first order model and a second order model of the two star scanner concepts are considered. Many of the stars that emit in the x-ray regime are also x-ray pulsars with frequency stability approaching a

  16. X-ray scattering from dense plasmas

    Energy Technology Data Exchange (ETDEWEB)

    McSherry, D.J

    2000-09-01

    Dense plasmas were studied by probing them with kilovolt x-rays and measuring those scattered at various angles. The Laser-Produced x-ray source emitted Ti He alpha 4.75 keV x-rays. Two different plasma types were explored. The first was created by laser driven shocks on either side of a sample foil consisting of 2 micron Al layer, sandwiched between two 1 micron CH layers. We have observed a peak in the x-ray scattering cross section, indicating diffraction from the plasma. However, the experimentally inferred plasma density, broadly speaking, did not always agree with the hydrodynamic simulation MEDX (A modified version of MEDUSA). The second plasma type that we studied was created by soft x-ray heating on either side of a sample foil, this time consisting of 1 micron layer of Al, sandwiched between two 0.2 micron CH layers. Two foil targets, each consisting of a 0.1 micron thick Au foil mounted on 1 micron of CH, where placed 4 mm from the sample foil. The soft x-rays where produced by laser irradiating these two foil targets. We found that, 0.5 ns after the peak of the laser heating pulses, the measured cross sections more closely matched those simulated using the Thomas Fermi model than the Inferno model. Later in time, at 2 ns, the plasma is approaching a weakly coupled state. This is the first time x-ray scattering cross sections have been measured from dense plasmas generated by radiatively heating both sides of the sample. Moreover, these are absolute values typically within a factor of two of expectation for early x-ray probe times. (author)

  17. X-ray laser program at MBI

    Science.gov (United States)

    Nickles, P. V.; Janulewicz, K. A.; Lucianetti, A.; Priebe, G.; Zigler, A.; Rocca, J. J.; Sandner, W.

    2002-11-01

    A survey of the Max Born Institute (MBI) activities in the field of X-ray lasers (XRLs) is presented. The main interest is focused on the transient soft X-ray lasers. Additionally, much work is put to look for new, efficient, compact (table-top) pumping schemes with a prospect to be applied in practice. The current state of the research and the plans for the future are described as well.

  18. Capacitor discharges, magnetohydrodynamics, X-rays, ultrasonics

    CERN Document Server

    Früngel, Frank B A

    1965-01-01

    High Speed Pulse Technology, Volume 1: Capacitor Discharges - Magnetohydrodynamics - X-Rays - Ultrasonics deals with the theoretical and engineering problems that arise in the capacitor discharge technique.This book discusses the characteristics of dielectric material, symmetrical switch tubes with mercury filling, and compensation conductor forms. The transformed discharge for highest current peaks, ignition transformer for internal combustion engines, and X-ray irradiation of subjects in mechanical motion are also elaborated. This text likewise covers the transformed capacitor discharge in w

  19. Supernova remnants: the X-ray perspective

    OpenAIRE

    Vink, Jacco

    2011-01-01

    Supernova remnants are beautiful astronomical objects that are also of high scientific interest, because they provide insights into supernova explosion mechanisms, and because they are the likely sources of Galactic cosmic rays. X-ray observations are an important means to study these objects.And in particular the advances made in X-ray imaging spectroscopy over the last two decades has greatly increased our knowledge about supernova remnants. It has made it possible to map the products of fr...

  20. Scattered X-ray beam nondestructive testing

    Science.gov (United States)

    Harding, G.; Kosanetzky, J.

    1989-08-01

    X-ray scatter interactions generally dominate the linear attenuation coefficient at the photon energies typical of medical and industrial radiography. Specific advantages of X-ray scatter imaging, including a flexible choice of measurement geometry, direct 3D-imaging capability (tomography) and improved information for material characterization, are illustrated with results from Compton and coherent scatter devices. Applications of a Compton backscatter scanner (ComScan) in the aerospace industry and coherent scatter imaging in security screening are briefly considered.

  1. Globular cluster x-ray sources.

    Science.gov (United States)

    Pooley, David

    2010-04-20

    Globular clusters and x-ray astronomy have a long and fruitful history. Uhuru and OSO-7 revealed highly luminous (> 10(36) ergs(-1)) x-ray sources in globular clusters, and Einstein and ROSAT revealed a larger population of low-luminosity (luminosity sources were low-mass x-ray binaries in outburst and that they were orders of magnitude more abundant per unit mass in globular clusters than in the rest of the galaxy. However, the low-luminosity sources proved difficult to classify. Many ideas were put forth--low-mass x-ray binaries in quiescence (qLMXBs), cataclysmic variables (CVs), active main-sequence binaries (ABs), and millisecond pulsars (MSPs)--but secure identifications were scarce. In ROSAT observations of 55 clusters, about 25 low-luminosity sources were found. Chandra has now observed over 80 Galactic globular clusters, and these observations have revealed over 1,500 x-ray sources. The superb angular resolution has allowed for many counterpart identifications, providing clues to the nature of this population. It is a heterogeneous mix of qLMXBs, CVs, ABs, and MSPs, and it has been shown that the qLMXBs and CVs are both, in part, overabundant like the luminous LMXBs. The number of x-ray sources in a cluster correlates very well with its encounter frequency. This points to dynamical formation scenarios for the x-ray sources and shows them to be excellent tracers of the complicated internal dynamics. The relation between the encounter frequency and the number of x-ray sources has been used to suggest that we have misunderstood the dynamical states of globular clusters.

  2. Globular cluster x-ray sources

    Science.gov (United States)

    Pooley, David

    2010-01-01

    Globular clusters and x-ray astronomy have a long and fruitful history. Uhuru and OSO-7 revealed highly luminous (> 1036 ergs-1) x-ray sources in globular clusters, and Einstein and ROSAT revealed a larger population of low-luminosity (luminosity sources were low-mass x-ray binaries in outburst and that they were orders of magnitude more abundant per unit mass in globular clusters than in the rest of the galaxy. However, the low-luminosity sources proved difficult to classify. Many ideas were put forth—low-mass x-ray binaries in quiescence (qLMXBs), cataclysmic variables (CVs), active main-sequence binaries (ABs), and millisecond pulsars (MSPs)—but secure identifications were scarce. In ROSAT observations of 55 clusters, about 25 low-luminosity sources were found. Chandra has now observed over 80 Galactic globular clusters, and these observations have revealed over 1,500 x-ray sources. The superb angular resolution has allowed for many counterpart identifications, providing clues to the nature of this population. It is a heterogeneous mix of qLMXBs, CVs, ABs, and MSPs, and it has been shown that the qLMXBs and CVs are both, in part, overabundant like the luminous LMXBs. The number of x-ray sources in a cluster correlates very well with its encounter frequency. This points to dynamical formation scenarios for the x-ray sources and shows them to be excellent tracers of the complicated internal dynamics. The relation between the encounter frequency and the number of x-ray sources has been used to suggest that we have misunderstood the dynamical states of globular clusters. PMID:20404204

  3. Parametric X-rays at FAST

    Energy Technology Data Exchange (ETDEWEB)

    Sen, Tanaji [Fermilab

    2016-06-01

    We discuss the generation of parametric X-rays (PXR) in the photoinjector at the new FAST facility at Fermilab. Detailed calculations of the intensity spectrum, energy and angular widths and spectral brilliance with a diamond crystal are presented. We also report on expected results with PXR generated while the beam is channeling. The low emittance electron beam makes this facility a promising source for creating brilliant X-rays.

  4. Detection limits in x-ray fluorescence analysis

    International Nuclear Information System (INIS)

    X-ray fluorescence spectrometry is a well established analytical technique for elemental analysis of solids, powders, or liquids. This extended abstract briefly discusses the detection limits or sensitivity of x-ray spectrometers in x-ray fluorescence analysis

  5. Optics Developments for X-Ray Astronomy

    Science.gov (United States)

    Ramsey, Brian

    2014-01-01

    X-ray optics has revolutionized x-ray astronomy. The degree of background suppression that these afford, have led to a tremendous increase in sensitivity. The current Chandra observatory has the same collecting area (approx. 10(exp 3)sq cm) as the non-imaging UHURU observatory, the first x-ray observatory which launched in 1970, but has 5 orders of magnitude more sensitivity due to its focusing optics. In addition, its 0.5 arcsec angular resolution has revealed a wealth of structure in many cosmic x-ray sources. The Chandra observatory achieved its resolution by using relatively thick pieces of Zerodur glass, which were meticulously figured and polished to form the four-shell nested array. The resulting optical assembly weighed around 1600 kg, and cost approximately $0.5B. The challenge for future x-ray astronomy missions is to greatly increase the collecting area (by one or more orders of magnitude) while maintaining high angular resolution, and all within realistic mass and budget constraints. A review of the current status of US optics for x-ray astronomy will be provided along with the challenges for future developments.

  6. Coherence in X-ray physics.

    Science.gov (United States)

    Lengeler, B

    2001-06-01

    Highly brilliant synchrotron radiation sources have opened up the possibility of using coherent X-rays in spectroscopy and imaging. Coherent X-rays are characterized by a large lateral coherence length. Speckle spectroscopy is extended to hard X-rays, improving the resolution to the nm range. It has become possible to image opaque objects in phase contrast with a sensitivity far superior to imaging in absorption contrast. All the currently available X-ray sources are chaotic sources. Their characterization in terms of coherence functions of the first and second order is introduced. The concept of coherence volume, defined in quantum optics terms, is generalized for scattering experiments. When the illuminated sample volume is smaller than the coherence volume, the individuality of the defect arrangement in a sample shows up as speckle in the scattered intensity. Otherwise, a configurational average washes out the speckle and only diffuse scattering and possibly Bragg reflections will survive. The loss of interference due to the finite detection time, to the finite detector pixel size and to uncontrolled degrees of freedom in the sample is discussed at length. A comparison between X-ray scattering, neutron scattering and mesoscopic electron transport is given. A few examples illustrate the possibilities of coherent X-rays for imaging and intensity correlation spectroscopy.

  7. Elliptical X-Ray Spot Measurement

    CERN Document Server

    Richardson, R A; Weir, J T; Richardson, Roger A.; Sampayan, Stephen; Weir, John T.

    2000-01-01

    The so-called roll bar measurement uses a heavy metal material, optically thick to x-rays, to form a shadow of the x-ray origination spot. This spot is where an energetic electron beam interacts with a high Z target. The material (the "roll bar") is slightly curved to avoid alignment problems. The roll bar is constructed and positioned so that the x-rays are shadowed in the horizontal and vertical directions, so information is obtained in two dimensions. If a beam profile is assumed (or measured by other means), the equivalent x-ray spot size can be calculated from the x-ray shadow cast by the roll bar. Thus the ellipticity of the beam can be calculated, assuming the ellipse of the x-ray spot is aligned with the roll bar. The data is recorded using a scintillator and gated camera. Data will be presented from measurements using the ETA II induction LINAC. The accuracy of the measurement is checked using small elliptical targets.

  8. Echoes in X-ray Binaries

    CERN Document Server

    O'Brien, K; Hynes, R; Chen, W; Haswell, C; Still, M

    2002-01-01

    We present a method of analysing the correlated X-ray and optical/UV variability in X-ray binaries, using the observed time delays between the X-ray driving lightcurves and their reprocessed optical echoes. This allows us to determine the distribution of reprocessing sites within the binary. We model the time-delay transfer functions by simulating the distribution of reprocessing regions, using geometrical and binary parameters. We construct best-fit time-delay transfer functions, showing the regions in the binary responsible for the reprocessing of X-rays. We have applied this model to observations of the Soft X-ray Transient, GRO j1655-40. We find the optical variability lags the X-ray variability with a mean time delay of 19.3$pm{2.2}$ seconds. This means that the outer regions of the accretion disc are the dominant reprocessing site in this system. On fitting the data to a simple geometric model, we derive a best-fit disk half-opening angle of 13.5$^{+2.1}_{-2.8}$ degrees, which is similar to that observe...

  9. A million X-ray detections

    Science.gov (United States)

    Webb, N.; XMM-Newton Survey Science Centre (SSC)

    2016-06-01

    Part of the XMM-Newton Survey Science Centre responsibilities include producing an X-ray catalogue of all X-ray sources detected with XMM-Newton. The latest version, 3XMM, takes advantage of improvements made to the source characterisation, reducing the number of spurious detections, but providing better astrometric precision, greater net sensitivity, as well as spectra and timeseries for a quarter of all catalogue detections. The data release 5 (3XMM-DR5, April 2015) is derived from the first 13 years of observations with XMM-Newton. 3XMM-DR5 includes 565962 X-ray detections and 396910 unique sources, detected as many as 48 times. 3XMM-DR5 is therefore the largest X-ray source catalogue. 3XMM-DR6 will be made available during 2016 and will augment the catalogue with 70000 X-ray detections. Over the next decade the catalogue will reach 1 million X-ray detections, including galaxy clusters, galaxies, tidal disruption events, gamma-ray bursts, stars, stellar mass compact objects, supernovae, planets, comets and many other systems. Thanks to the wide range of data products for each catalogue detection, the catalogue is an excellent resource for finding populations of sources as well as new and extreme objects. Here we present results achieved from searching the catalogue and discuss improvements that will be provided in future versions.

  10. X-ray Emission of Hollow Atoms

    Institute of Scientific and Technical Information of China (English)

    ZhaoYongtao; XiaoGuoqing; ZhangXiaoan; YangZhihu; ChenXimeng; ZhangYanping

    2003-01-01

    We have systematically investigated the X-rays emission of hollow atoms (HA) which formed in the interaction of highly charged ions with a variety of solid surfaces at the atomic physics experimental setup of IMP. The X-ray spectra were measured by Si(Li) detectors with effective energy ranging from 1 keV to 60 keV. The results show that, the X-ray emission from the formed HA is closely correlated with the charge state of the projectile ions, and weakly correlated with the velocity of the projectile ions. For example, it was found that when Ar18+ ions interact with Be-target, the yield of K X-ray with character energy of 3.0 keV is 7.2×10-3 per ion, which is two times and 5 order of magnitude higher than those in the interactions of Ar17+ and Ar16+ ions respectively. When Ar15+ ions interact with the same targets, the Argon K X-ray would be too feeble to be detected. The X-ray yield with single ion in this experiment can be represented by the following equation,

  11. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... Test/Treatment Patient Type Screening/Wellness Disease/Condition Safety En Español More Info Images/Videos News Physician ... minimize radiation exposure to the baby. See the Safety page for more information about pregnancy and x- ...

  12. Controlled Use of X-Ray in Dental Practice

    Directory of Open Access Journals (Sweden)

    Lesbia Rosa Tirado-Amado

    2015-01-01

    Full Text Available Abstract: Objective: To contribute in an informative and critical way to the promotion of controlled use of X-ray during dental consulting and dental care. Introduction: The practice of dentistry as a health care service requires the use of complementary tools for proper diagnosis, treatment and follow-up in patients with different clinical conditions. For that reason, the use of x-ray by dentists is common and very useful, but it involves radiation exposure to the patient and the dental professional or dental student. Although, often people do not pay attention to this exposition in regard to biological effects, because they are considered too low to generate significant biological effects. Conclusion: It is necessary to consider the risk of accumulative doses for constant exposure in dentist and dental students. Moreover, in patients, because a synergism with other radiations can occur, they can be exposed because of the attention in other areas of health. For these reasons, it is necessary to promote awareness and knowledge on basic aspects of the controlled use of X-ray in the dental care, being also aware of the need to strengthen the knowledge of the basics aspects that lead to decreased risk of biological effects from its proper use in the dental care.

  13. Self-propelled x-ray flaw detector

    International Nuclear Information System (INIS)

    A self-propelled X-ray flaw detector for radiographic inspection of welded joints in pipelines comprises a carriage mounting a motor, a detector having two Geiger counters, a pulsed X-ray generator, and an exposure and carriage electronic control system. A memory unit in the control system has four storage elements containing information about the motion of the carriage. As the carriage moves in direction A, first one and then the other of the Geiger counters receives radiation from an isotope source positioned near a joint, and by means of logic circuitry in the control system, the information in the storage elements is modified to stop the carriage and to operate a timer to expose the weld. During exposure the X-rays may interfere with the information in the storage elements, but by means of a square-wave generator and the logic circuitry, the stored information is correctly reset in order to eliminate false operation of the memory unit. (author)

  14. Effects of x-ray does on rhizosphere studies using x-ray computed tomography

    OpenAIRE

    Susan Zappala; Jonathan R Helliwell; Tracy, Saoirse R.; Stefan Mairhofer; Sturrock, Craig J.; Tony Pridmore; Malcolm Bennett; Sacha J. Mooney

    2013-01-01

    X-ray Computed Tomography (CT) is a non-destructive imaging technique originally designed for diagnostic medicine, which was adopted for rhizosphere and soil science applications in the early 1980s. X-ray CT enables researchers to simultaneously visualise and quantify the heterogeneous soil matrix of mineral grains, organic matter, air-filled pores and water-filled pores. Additionally, X-ray CT allows visualisation of plant roots in situ without the need for traditional invasive methods such ...

  15. Simulation of transmitted X-rays in a polycapillary X-ray lens

    Energy Technology Data Exchange (ETDEWEB)

    Peng, Shiqi [The Key Laboratory of Beam Technology and Material Modification of the Ministry of Education, Beijing Normal University, Beijing 100875 (China); College of Nuclear Science and Technology, Beijing Normal University, Beijing 100875 (China); Beijing Radiation Center, Beijing 100875 (China); Liu, Zhiguo, E-mail: liuzhiguo512@126.com [The Key Laboratory of Beam Technology and Material Modification of the Ministry of Education, Beijing Normal University, Beijing 100875 (China); College of Nuclear Science and Technology, Beijing Normal University, Beijing 100875 (China); Beijing Radiation Center, Beijing 100875 (China); Sun, Tianxi; Wang, Kai; Yi, Longtao; Yang, Kui; Chen, Man; Wang, Jinbang [The Key Laboratory of Beam Technology and Material Modification of the Ministry of Education, Beijing Normal University, Beijing 100875 (China); College of Nuclear Science and Technology, Beijing Normal University, Beijing 100875 (China); Beijing Radiation Center, Beijing 100875 (China)

    2015-09-21

    The geometrical description of capillary systems adjusted for the controlled guiding of X-rays and the basic theory of the transmission of X-rays are presented. A method of numerical calculation, based on Ray-Tracing theory, is developed to simulate the transmission efficiency of an X-ray parallel lens and the shape and size of the light spot gain from it. The simulation results for two half-lenses are in good agreement with the experimental results.

  16. Simulation of transmitted X-rays in a polycapillary X-ray lens

    International Nuclear Information System (INIS)

    The geometrical description of capillary systems adjusted for the controlled guiding of X-rays and the basic theory of the transmission of X-rays are presented. A method of numerical calculation, based on Ray-Tracing theory, is developed to simulate the transmission efficiency of an X-ray parallel lens and the shape and size of the light spot gain from it. The simulation results for two half-lenses are in good agreement with the experimental results

  17. A comparison of Kodak DEF Industrex CX and Industrex AX films at soft x-ray wavelengths

    International Nuclear Information System (INIS)

    Kodak direct exposure film (DEF), and the Kodak Industrex films CX and AX have been compared, using a DC X-ray source to generate 1.5 keV soft X-rays. Characteristic curves are presented for the three films, also detective quantum efficiencies as a function of incident X-ray flux. The effect of developer temperature on the characteristic curve has also been investigated. (author)

  18. Comparison of x-ray output of inverter-type x-ray equipment

    International Nuclear Information System (INIS)

    The x-ray output of 54 inverter-type x-ray apparatuses used at 18 institutions was investigated. The reproducibility and linearity of x-ray output and variations among the x-ray equipment were evaluated using the same fluorescence meter. In addition, the x-ray apparatuses were re-measured using the same non-invasive instrument to check for variations in tube voltage, tube current, and irradiation time. The non-invasive instrument was calibrated by simultaneously obtaining measurements with an invasive instrument, employing the tube voltage and current used for the invasive instrument, and the difference was calculated. Reproducibility of x-ray output was satisfactory for all x-ray apparatuses. The coefficient of variation was 0.04 or less for irradiation times of 5 ms or longer. In 84.3% of all x-ray equipment, variation in the linearity of x-ray output was 15% or less for an irradiation time of 5 ms. However, for all the apparatuses, the figure was 50% when irradiation time was the shortest (1 to 3 ms). Variation in x-ray output increased as irradiation time decreased. Variation in x-ray output ranged between 1.8 and 2.5 compared with the maximum and minimum values, excluding those obtained at the shortest irradiation time. The relative standard deviation ranged from ±15.5% to ±21.0%. The largest variation in x-ray output was confirmed in regions irradiated for the shortest time, with smaller variations observed for longer irradiation times. The major factor responsible for variation in x-ray output in regions irradiated for 10 ms or longer, which is a relatively long irradiation time, was variation in tube current. Variation in tube current was slightly greater than 30% at maximum, with an average value of 7% compared with the preset tube current. Variations in x-ray output in regions irradiated for the shortest time were due to photographic effects related to the rise and fall times of the tube voltage waveform. Accordingly, in order to obtain constant x-ray

  19. Laser-based X-ray and electron source for X-ray fluorescence studies

    Science.gov (United States)

    Valle Brozas, F.; Crego, A.; Roso, L.; Peralta Conde, A.

    2016-08-01

    In this work, we present a modification to conventional X-rays fluorescence using electrons as excitation source and compare it with the traditional X-ray excitation for the study of pigments. For this purpose, we have constructed a laser-based source capable to produce X-rays as well as electrons. Because of the large penetration depth of X-rays, the collected fluorescence signal is a combination of several material layers of the artwork under study. However, electrons are stopped in the first layers, allowing a more superficial analysis. We show that the combination of both excitation sources can provide extremely valuable information about the structure of the artwork.

  20. Instrumentation system for multi measure of parameters of diagnosis X-ray equipment

    International Nuclear Information System (INIS)

    Innovative methodologies of a Multi-measuring instrumentation system the following parameters: CSR kVp, kerma air kerma rate, exposure time, field size and the number of X-ray pulses are presented. Thus, the instrument applies both to measure some parameters of conventional X-ray equipment as dental equipment. The methods used are based on modern electronic measurement techniques Sensor unconventional X-rays, such as bipolar junction transistor (BJT) with a certain bias electrical signals. In fact, the proper polarization allows to measure each parameter or magnitude from interference of photons in the device converting the TBJ of the output signal in a modulated signal by Interaction of radiation. The output signal is then processed by a microprocessor to convert the greatness or endpoint of the X-ray equipment. The results show that the multi-measuring system has proposed a relative uncertainty 1% and 5% for kVp and CSR parameters, respectively, for conventional x-ray equipment, and less than 1% for the exposure time in equipment dental X-rays. The proposed system brings innovation to the art and has metrological character providing be applied to quality control of diagnostic X-ray equipment