WorldWideScience

Sample records for radiation propagation chemical-biological

  1. Radiation, chemical and biological protection. Mass destruction weapons

    International Nuclear Information System (INIS)

    Janasek, D.; Svetlik, J.

    2005-01-01

    In this text-book mass destruction weapons and radiation, chemical and biological protection are reviewed. The text-book contains the following chapter: (1) Mass destruction weapons; (2) Matter and material; (3) Radioactive materials; (4) Toxic materials; (5) Biological resources; (6) Nuclear energetic equipment; Appendices; References.

  2. Comparative biological hazards of chemical pollutants and radiation

    International Nuclear Information System (INIS)

    Mukherjee, R.N.

    1978-01-01

    Chemical pollutants from conventional energy and industrial sources released to the environment presumably pose a hazard to man's health and environmental resources. Insufficient knowledge of their detailed mechanisms of interaction with the biological systems seems to provide the greatest drawback in current attempts for realistic assessment of the health risks of chemical pollutants in the short and long terms. Nevertheless, their detrimental health consequences are becoming more and more apparent as a result of recent epidemiological surveys of workers in conventional energy installations and of the chronically exposed general public. So far nuclear power has succeeded in achieving a remarkable health safety record. In view of its projected expansion, research on biological effects of low-level radiation and radionuclides should continue to re-evaluate the health safety consequences. However, a projection from past experiences together with continued efforts to improvements of health safety aspects seem to justify an expectation that the proposed expansions in the nuclear power programme should not have an unfavourable impact on the environment. The potential hazards and challenges from the associated radiation in man's environment have proved manageable. More attention now needs to be paid urgently to safeguard human health and environment against the chemical pollutants

  3. Comparative biological hazards of chemical pollutants and radiation

    Energy Technology Data Exchange (ETDEWEB)

    Mukherjee, R N [International Atomic Energy Agency, Vienna (Austria). Div. of Life Sciences

    1978-06-01

    Chemical pollutants from conventional energy and industrial sources released to the environment presumably pose a hazard to man's health and environmental resources. Insufficient knowledge of their detailed mechanisms of interaction with the biological systems seems to provide the greatest drawback in current attempts for realistic assessment of the health risks of chemical pollutants in the short and long terms. Nevertheless, their detrimental health consequences are becoming more and more apparent as a result of recent epidemiological surveys of workers in conventional energy installations and of the chronically exposed general public. So far nuclear power has succeeded in achieving a remarkable health safety record. In view of its projected expansion, research on biological effects of low-level radiation and radionuclides should continue to re-evaluate the health safety consequences. However, a projection from past experiences together with continued efforts to improvements of health safety aspects seem to justify an expectation that the proposed expansions in the nuclear power programme should not have an unfavourable impact on the environment. The potential hazards and challenges from the associated radiation in man's environment have proved manageable. More attention now needs to be paid urgently to safeguard human health and environment against the chemical pollutants.

  4. Chemical and biological effects of radiation sterilization of medical products

    International Nuclear Information System (INIS)

    Gupta, B.L.

    1975-01-01

    Radiation is extensively used for the sterilization of plastic materials, pharmaceuticals and biological tissue grafts. The pharmaceuticals may be solid, liquid, or suspension in a liquid or a solution. Cobalt-60 gamma radiation, generally used for sterilization, primarily interacts with these materials through the Compton process. The resulting damage may be direct or indirect. In aqueous systems the primary species produced compete for interaction among themselves and the dissolved solutes. The nature, the G-values and the reactions of the primary species very much depend on the pH of the solution. The important chemical changes in plastic materials are gas liberation, change in concentration of double bonds, cross-linking, degradation and oxidation. These chemical changes lead to some physical changes like crystallinity, specific conductivity and permeability. The reactions in biological systems are very complex and are influenced by the presence or absence of water and oxygen. Water produces indirect damage and the radiation effect is generally more in the presence of oxygen. Most microorganisms are relatively radioresistant. Various tissues of an animal differ in their response to radiation. Catgut is not stable to irradiation. Lyophilized human serum is stable to irradiation whereas, when irradiated in aqueous solutions, several changes are observed. Generally, pharmaceuticals are considerably more stable in the dry solid state to ionizing radiations than in aqueous solutions or in any other form of molecular aggregation. (author)

  5. Biological Effects of Ionizing Radiation

    Science.gov (United States)

    Ingram, M.; Mason, W. B.; Whipple, G. H.; Howland, J. W.

    1952-04-07

    This report presents a review of present knowledge and concepts of the biological effects of ionizing radiations. Among the topics discussed are the physical and chemical effects of ionizing radiation on biological systems, morphological and physiological changes observed in biological systems subjected to ionizing radiations, physiological changes in the intact animal, latent changes following exposure of biological systems to ionizing radiations, factors influencing the biological response to ionizing radiation, relative effects of various ionizing radiations, and biological dosimetry.

  6. Radiation biology. Chapter 20

    Energy Technology Data Exchange (ETDEWEB)

    Wondergem, J. [International Atomic Energy Agency, Vienna (Austria)

    2014-09-15

    Radiation biology (radiobiology) is the study of the action of ionizing radiations on living matter. This chapter gives an overview of the biological effects of ionizing radiation and discusses the physical, chemical and biological variables that affect dose response at the cellular, tissue and whole body levels at doses and dose rates relevant to diagnostic radiology.

  7. Physical, chemical, and biological properties of radiocerium relevant to radiation protection guidelines

    International Nuclear Information System (INIS)

    Anon.

    1978-01-01

    Present knowledge of the relevant physical, chemical, and biological properties of radiocerium as a basis for establishing radiation protection guidelines is summarized. The first section of the report reviews the chemical and physical properties of radiocerium relative to the biological behavior of internally-deposited cerium and other lanthanides. The second section of the report gives the sources of radiocerium in the environment and the pathways to man. The third section of the report describes the metabolic fate of cerium in several mammalian species as a basis for predicting its metabolic fate in man. The fourth section of the report considers the biomedical effects of radiocerium in light of extensive animal experimentation. The last two sections of the report describe the history of radiation protection guidelines for radiocerium and summarize data required for evaluating the adequacy of current radiation protection guidelines. Each section begins with a summary of the most important findings that follow

  8. Biological Effects of Radiation

    International Nuclear Information System (INIS)

    Jatau, B.D.; Garba, N.N.; Yusuf, A.M.; Yamusa, Y. A.; Musa, Y.

    2013-01-01

    In earlier studies, researchers aimed a single particle at the nucleus of the cell where DNA is located. Eighty percent of the cells shot through the nucleus survived. This contradicts the belief that if radiation slams through the nucleus, the cell will die. But the bad news is that the surviving cells contained mutations. Cells have a great capacity to repair DNA, but they cannot do it perfectly. The damage left behind in these studies from a single particle of alpha radiation doubled the damage that is already there. This proved, beyond a shadow of doubt, those there biological effects occur as a result of exposure to radiation, Radiation is harmful to living tissue because of its ionizing power in matter. This ionization can damage living cells directly, by breaking the chemical bonds of important biological molecules (particularly DNA), or indirectly, by creating chemical radicals from water molecules in the cells, which can then attack the biological molecules chemically. At some extent these molecules are repaired by natural biological processes, however, the effectiveness of this repair depends on the extent of the damage. The interaction of ionizing with the human body, arising either from external sources outside the body or from internal contamination of the body by radioactive materials, leads to the biological effects which may later show up as a clinical symptoms. Basically, this formed the baseline of this research to serve as a yardstick for creating awareness about radiation and its resulting effects.

  9. Roles of radiation chemistry in development and research of radiation biology

    International Nuclear Information System (INIS)

    Min Rui

    2009-01-01

    Radiation chemistry acts as a bridge connecting radiation physics with radiation biology in spatial and temporal insight. The theory, model, and methodology coming from radiation chemistry play an important role in the research and development of radiation biology. The chemical changes induced by ionizing radiation are involved not only in early event of biological effects caused by ionizing radiation but in function radiation biology, such as DNA damage and repair, sensitive modification, metabolism and function of active oxygen and so on. Following the research development of radiation biology, systems radiation biology, accurate quality and quantity of radiation biology effects need more methods and perfect tools from radiation chemistry. (authors)

  10. Radiation Dose Measurement Using Chemical Dosimeters

    International Nuclear Information System (INIS)

    Lee, Min Sun; Kim, Eun Hee; Kim, Yu Ri; Han, Bum Soo

    2010-01-01

    The radiation dose can be estimated in various ways. Dose estimates can be obtained by either experiment or theoretical analysis. In experiments, radiation impact is assessed by measuring any change caused by energy deposition to the exposed matter, in terms of energy state (physical change), chemical production (chemical change) or biological abnormality (biological change). The chemical dosimetry is based on the implication that the energy deposited to the matter can be inferred from the consequential change in chemical production. The chemical dosimetry usually works on the sample that is an aqueous solution, a biological matter, or an organic substance. In this study, we estimated absorbed doses by quantitating chemical changes in matter caused by radiation exposure. Two different chemical dosimeters, Fricke and ECB (Ethanol-Chlorobenzene) dosimeter, were compared in several features including efficacy as dose indicator and effective dose range

  11. Biological efficiency of interaction between various radiation and chemicals

    International Nuclear Information System (INIS)

    Kim, Jin Kyu; Yu, Dong Han; Lee, Byoung Hun; Petin, Vladislav G.; Geras'kin, Stanislav A.; Cebulska-Wasilewska, Antonina; Panek, Agnieszka; Wiechec, Anna

    2004-06-01

    This research project has been carried out jointly with INP (Poland) to develop technologies to assess the biological efficiency of interaction between radiation and chemicals. Through the cooperative project, KAERI and INP have established wide variety of bioassay techniques applicable to radiation bioscience, human monitoring, molecular epidemiology and environmental science. The joint experiment, in special, made it possible to utilize the merits of both institutes and to upgrade and verify KAERI's current technology level. All results of the cooperative research will be jointly published in high standard scientific journals listed in the Science Citation Index (SCI), which can make the role of fundamental basis for improving relationship between Korea and Poland. Research skills such as Trad-MCN assay, SCGE assay, immunohistochemical assay and molecular assay developed through joint research will be further elaborated and will be continuously used for the collaboration between two institutes

  12. Chemical effects of radiation

    International Nuclear Information System (INIS)

    Philips, G.O.

    1986-01-01

    Ionizing radiations initiate chemical changes in materials because of the high energy of their quanta. In water, highly reactive free radicals are produced which can initiate secondary changes of solutes, and in chemical of biological molecules in contact with the water. Free radicals can also be directly produced in irradiated medical products. Their fate can be identified and the molecular basis of radiation inactivation clarified. Methods have now been developed to protect and minimise such radiation damage. (author)

  13. Introduction to radiation biology

    International Nuclear Information System (INIS)

    Uma Devi, P.; Satish Rao, B.S.; Nagarathnam, A.

    2000-01-01

    This book is arranged in a logical sequence, starting from radiation physics and radiation chemistry, followed by molecular, subcellular and cellular effects and going on to the level of organism. Topics covered include applied radiobiology like modifiers of radiosensitivity, predictive assay, health physics, human genetics and radiopharmaceuticals. The topics covered are : 1. Radiation Physics, 2. Detection and Measurement of Radiation, 3. Radiation Chemistry, 4. DNA Damage and Repair, 5. Chromosomal Aberrations and Gene Mutations, 6. Cellular Radiobiology 7. Acute Radiation Effects, 8. Delayed Effects of Radiation, 9. Biological Basis of Radiotherapy, 10. Chemical Modifiers of Radiosensitivity, 11. Hyperthermia, 12. High LET Radiations in Cancer, Therapy, 13. Predictive Assays, 14. Radiation Effects on Embryos, 15. Human Radiation Genetics, 16. Radiolabelled Compounds in Biology and Medicine and 17. Radiological Health

  14. Redox processes in radiation biology and cancer

    International Nuclear Information System (INIS)

    Greenstock, C.L.

    1981-01-01

    Free-radical intermediates, particularly the activated oxygen species OH, O - 2 , and 1 O 2 , are implicated in many types of radiation damage to biological systems. In addition, these same species may be formed, either directly or indirectly through biochemical redox reactions, in both essential and aberrant metabolic processes. Cell survival and adaptation to an environment containing ionizing radiation and other physical and chemical carcinogens ultimately depend upon the cell's ability to maintain optimal function in response to free-radical damage at the chemical level. Many of these feedback control mechanisms are redox controlled. Radiation chemical techniques using selective radical scavengers, such as product analysis and pulse radiolysis, enable us to generate, observe, and characterize individually the nature and reactivity of potentially damaging free radicals. From an analysis of the chemical kinetics of free-radical involvement in biological damage, redox mechanisms are proposed to describe the early processes of radiation damage, redox mechanisms are proposed to describe the early processes of radiation damage, its protection and sensitization, and the role of free radicals in radiation and chemical carcinogenesis

  15. Chemical protection against ionizing radiation

    International Nuclear Information System (INIS)

    Livesey, J.C.; Reed, D.J.

    1987-01-01

    Over 40 years have passed since the research of the Manhattan Project suggested the possibility of chemical protection against ionizing radiation. During that time, much has been learned about the nature of radiation-induced injury and the factors governing the expression of that injury. Thousands of compounds have been tested for radioprotective efficacy, and numerous theories have been proposed to account for these actions. The literature on chemical radioprotection is large. In this article, the authors consider several of the mechanisms by which chemicals may protect against radiation injury. They have chosen to accent this view of radioprotector research as opposed to that research geared toward developing specific molecules as protective agents because they feel that such an approach is more beneficial in stimulating research of general applicability. This paper describes the matrix of biological factors upon which an exogenous radioprotector is superimposed, and examines evidence for and against various mechanisms by which these agents may protect biological systems against ionizing radiation. It concludes with a brief outlook for research in chemical radioprotection

  16. Radiation, chemicals, and occupational health research

    International Nuclear Information System (INIS)

    Turner, J.E.

    1984-01-01

    Radiation protection and its interplay with physical research programs are described. Differences and similarities between problems in health protection for chemicals and for radiation are discussed. The importance of dosimetry in radiation work and its relevance to chemicals are cited. A collaborative program between physical and biological scientists on the toxicity of metals is briefly described. It serves as an example of new research directed toward the development of fundamental concepts and principles as a basis for understanding and controlling occupational and population exposures to chemicals. 12 references, 4 figures

  17. Comparison of radiation and chemical risks

    International Nuclear Information System (INIS)

    Bengtsson, G.

    1988-01-01

    Injury to living cells is caused by mechanisms which in many cases are similar for radiation and chemicals. It is thus not surprising that radiation and many chemicals can cause similar biological effects, e.g. cancer, fetal injury and hereditary disease. Both radiation and chemicals are always found in our environment. One agent may strengthen or weaken the effect of another, be it radiation in combination with chemicals or one chemical with another. The implications of such synergistic or antagonistic effects are discussed. Intricate mechanisms help the body to defend itself against threats to health from radiation and chemicals, even against cancer risks. In a strategy for health, it might be worth to exploit actively these defense mechanisms, in parallel with decreasing the exposures. On particular interest are the large exposures from commonly known sources such as smoking, sun tanning and high fat contents of food. (author)

  18. Propagation of synchrotron radiation through nanocapillary structures

    International Nuclear Information System (INIS)

    Bjeoumikhov, A.; Bjeoumikhova, S.; Riesemeier, H.; Radtke, M.; Wedell, R.

    2007-01-01

    The propagation of synchrotron radiation through nanocapillary structures with channel sizes of 200 nm and periods in the micrometer size has been studied experimentally. It was shown that the propagation through individual capillary channels has a mode formation character. Furthermore it was shown that during the propagation through capillary channels the coherence of synchrotron radiation is partially conserved. Interference of beams propagating through different capillary channels is observed which leads to a periodically modulated distribution of the radiation intensity in a plane far from the exit of the structure. These investigations are of high relevance for the understanding of X-ray transmission through nanocapillaries and the appearance of wave properties at this size scale

  19. Low environmental radiation background impairs biological defence of the yeast Saccharomyces cerevisiae to chemical radiomimetic agents

    International Nuclear Information System (INIS)

    Satta, L.; Augusti-Tocco, G.; Ceccarelli, R.; Paggi, P.; Scarsella, G.; Esposito, A.; Fiore, M.; Poggesi, I.; Ricordy, R.; Cundari, E.

    1995-01-01

    Background radiation is likely to constitute one of the factors involved in biological evolution since radiations are able to affect biological processes. Therefore, it is possible to hypothesize that organisms are adapted to environmental background radiation and that this adaptation could increase their ability to respond to the harmful effects of ionizing radiations. In fact, adaptive responses to alkylating agents and to low doses of ionizing radiation have been found in many organisms. In order to test for effects of adaptation, cell susceptibility to treatments with high doses of radiomimetic chemical agents has been studied by growing them in a reduced environmental radiation background. The experiment has been performed by culturing yeast cells (Saccharomyces cerevisiae D7) in parallel in a standard background environment and in the underground Gran Sasso National Laboratory, with reduced environmental background radiation. After a conditioning period, yeast cells were exposed to recombinogenic doses of methyl methanesulfonate. The yeast cells grown in the Gran Sasso Laboratory showed a higher frequency of radiomimetic induced recombination as compared to those grown in the standard environment. This suggests that environmental radiation may act as a conditioning agent

  20. Biological effects of radiation and estimation of risk to radiation workers

    International Nuclear Information System (INIS)

    Murthy, M.S.S.

    1987-01-01

    The biological effects of radiation have three stages: physical, chemical and biological. A precise mathematical description of biological effects and of one-to-one correspondence between the initial energy absorption and final effect has not been possible, because several factors are involved in biological effects and their manifestation period varies from less than one second to several years. The mechanism of biological radiation effects is outlined. The two groups of these effects are (1) immediate and (2) delayed. The main aim of radiation protection programme is to eliminate the risk of non-stochastic effects to an acceptable level. The mean annual dose for 30,000 radiation workers in India is 2.7 m Sv. Estimated risk of fatal cancer from this dose is about 50 cases of cancer per year per million workers which is well below the ICRP standard for safe occupation stipulated at fatality rate less than or equal to 100 per year per milion workers. When compared with risk in other occupations, the risk to radiation workers is much less. (M.G.B.)

  1. Biological Effects of Interaction between Radiation and Chemicals

    Energy Technology Data Exchange (ETDEWEB)

    Hyun, Kyung Man; Han, Min; Kim, Jin Kyu [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Nili, Mohammad [Dawnesh Radiation Research Institute, Barcelona (Spain)

    2009-05-15

    The organisms are exposed to natural radiations from cosmic or terrestrial origins. Radiation is known to cause cell death, mainly due to its ability to produce reactive oxygen species in cells. The combined action between radiation and various chemicals is a distinguishing feature of modern life. Mercury chloride is a widespread environmental pollutant that is known to have toxic effects. Synergistic effects of radiation and HgCl{sub 2} on human cells was previously reported. NAC is a well-known sulfhydryl-containing antioxidant whose role in radioprotection has been explored in several studies. There has been an increasing interest of studying the role of NAC as a radioprotective substance. The present study was designed not only to assess the synergistic effects between radiation and HgCl{sub 2}, but also to investigate protective effects of NAC on cells.

  2. Development trend of radiation biology research-systems radiation biology

    International Nuclear Information System (INIS)

    Min Rui

    2010-01-01

    Radiation biology research has past 80 years. We have known much more about fundamentals, processes and results of biology effects induced by radiation and various factors that influence biology effects wide and deep, however many old and new scientific problems occurring in the field of radiation biology research remain to be illustrated. To explore and figure these scientific problems need systemic concept, methods and multi dimension view on the base of considerations of complexity of biology system, diversity of biology response, temporal and spatial process of biological effects during occurrence, and complex feed back network of biological regulations. (authors)

  3. Radiation biology and radiation therapy

    International Nuclear Information System (INIS)

    Wideroee, R.

    1975-01-01

    Radiation biology and radiation therapy can be compared with investigations in different layers of earth. Radiation biology works upwards from the elementary foundations, therapy works downwards with roots to secure and improve the clinical 'surface work'. The Ellis formula (Strandquist), which is a collection of clinical experience, is suited to form connections with radiobiology in the middle layers, and cooperation can give impulses for research. The structure and conditions of tumours and the complicated problems met with are discussed, based on the Carmel symposium of 1969. The oxygen problem in anoxic tumours is not yet solved. Experimental investigations of the effect itself give partly contradictory results. From a clinical viewpoint reoxygenation is of the utmost significance for obtaining control over the primary tumour, and advanced irradiation programmes will here give better results than the traditional ones. New chemicals, e.g. R 0 -07-0582, appear to reduce the OER value to 1.5, thereby making neutron therapy superfluous. Finally a problem from fundamental research is dealt with, wherein two hypotheses explaining the β-effect are described. The repair hypothesis gives a simple explanation but leaves many questions unanswered. The other hypothesis explains the β-effect as two neighbouring single breaks of the DNA molecule. It still presents difficulties, and is scarcely the correct explanation. (JIW)

  4. Applied radiation biology and protection

    International Nuclear Information System (INIS)

    Granier, R.; Gambini, D.J.

    1990-01-01

    Written by two eminent expects in the field with many years of teaching experience between them, this book presents a concise coverage of the physical and biological basics of radiation biology and protection. The book begins with a description of the methods of particle detection and dosimetric evaluation. The effects of ionizing radiation on man are treated from the initial physico-chemical phase of interaction to their conceivable pathological consequences. Regulations, limits and safeguards on nuclear power plants, radioisotope installations and medical centers which make use of ionizing radiation are given and the risks of exposure to natural, industrial and scientific radiation sources evaluated. The final chapter takes a look at some of the more important nuclear accidents, including Windscale, Three Mile Island, and Chernobyl, and describes basic procedures to be carried out in the eventuality of a nuclear emergency. Twelve chapters have been processed separately for inclusion in the appropriate data bases

  5. Influence of vitamins on cytostatic drugs: radiation-chemical and radiation-biological investigations in vitro

    International Nuclear Information System (INIS)

    Heinrich, E.

    2002-03-01

    Many environmental burdens (air pollution, formation of ozone etc.), humans nowadays are exposed to, in connection with unhealthy way of living promote the formation of free radicals e.g. OH and peroxylradicals in the organism. Those show an enormous cell-damaging effect, and can weaken the immune system or cause cancer diseases. The number of humans suffering from different forms of cancer is rising world-wide. Therefore it is necessary to find new and better therapy forms for this illness. The organism has its own protective system, which is able to capture free radicals and make them innocuous to a large extent. Apart from various enzyme systems the antioxidizing vitamins C (ascorbic acid), E (α-tocopherol) and β-carotin play an important role in this process. Now it was of interest whether vitamin B1 (thiamine) also possesses the ability to work as a radiation protector or to influence the effect of different cytostatic drugs. In the context of this thesis the radiation-chemical and radiation-biological behaviour of vitamin B1 was examined under different conditions (in presence and absence of oxygen as well as in media saturated with N 2 O). HPLC analysis were performed to establish radiolysis products. Furthermore the synergistic effect of vitamin B1 on cytostatic drugs (sanazole, mitomycin C) was studied alone or in combination with other vitamins (C, E and β-carotin) by using two different E. coli bacteria strains as a model for living systems. (author)

  6. Chemical protection and sensitization to ionizing radiation:molecular investigations

    International Nuclear Information System (INIS)

    Badiello, R.

    1980-01-01

    Chemical radioprotection and radiosensitization are induced by the presence of certain chemical compounds, which reduce or enhance the effect of ionizing radiation on living organisms. Such substances are either naturally present or may be artificially introduced in the living cells. Chemical radioprotectors are interesting for possible application in the health protection of both professionally exposed workers and patients treated by radiation for diagnostic and thereapeutic purposes. Interest in chemical radiosensitization has increased recently because of its potential application in the radiotherapy of tumours. Both radioprotection and radiosensitization occur by means of complicated mechanisms, which at first correspond to very fast reactions. The mechanism of the interaction between such substances and radiation-induced biological radicals has been investigated by means of pulse radiolysis and rapid mixing techniques. Examples of the application of these techniques are given to illustrate how information has been obtained on the molecular basis of radiation chemical modi-fication at the cellular level. In particular some interactions between model systems of biological interest (DNA, DNA components, enzymes, amino acids, etc.) and sulphur-containing radioprotectors (glutathione, cysteine, etc.) and/or electroaffinic radiosensitizers, are described. (H.K.)

  7. Current research in Radiation Biology and Biochemistry Division

    International Nuclear Information System (INIS)

    Tarachand, U.; Singh, B.B.

    1995-01-01

    The Radiation Biology and Biochemistry Division, Bhabha Atomic Research Centre, Bombay has been engaged in research in the frontier areas of (i) radiation biology related to tumour therapy and injury caused by free radicals; (ii) molecular basis of diseases of physiological origin; (iii) molecular aspects of chemical carcinogenesis and (iv) structure of genome and genome related functions. The gist of research and development activities carried out in the Division during the last two years are documented

  8. Current research in Radiation Biology and Biochemistry Division

    Energy Technology Data Exchange (ETDEWEB)

    Tarachand, U; Singh, B B [eds.; Bhabha Atomic Research Centre, Bombay (India). Radiation Biology and Biochemistry Div.

    1996-12-31

    The Radiation Biology and Biochemistry Division, Bhabha Atomic Research Centre, Bombay has been engaged in research in the frontier areas of (i) radiation biology related to tumour therapy and injury caused by free radicals; (ii) molecular basis of diseases of physiological origin; (iii) molecular aspects of chemical carcinogenesis and (iv) structure of genome and genome related functions. The gist of research and development activities carried out in the Division during the last two years are documented.

  9. Chemical protection against ionizing radiation. Final report

    International Nuclear Information System (INIS)

    Livesey, J.C.; Reed, D.J.; Adamson, L.F.

    1984-08-01

    The scientific literature on radiation-protective drugs is reviewed. Emphasis is placed on the mechanisms involved in determining the sensitivity of biological material to ionizing radiation and mechanisms of chemical radioprotection. In Section I, the types of radiation are described and the effects of ionizing radiation on biological systems are reviewed. The effects of ionizing radiation are briefly contrasted with the effects of non-ionizing radiation. Section II reviews the contributions of various natural factors which influence the inherent radiosensitivity of biological systems. Inlcuded in the list of these factors are water, oxygen, thiols, vitamins and antioxidants. Brief attention is given to the model describing competition between oxygen and natural radioprotective substances (principally, thiols) in determining the net cellular radiosensitivity. Several theories of the mechanism(s) of action of radioprotective drugs are described in Section III. These mechanisms include the production of hypoxia, detoxication of radiochemical reactive species, stabilization of the radiobiological target and the enhancement of damage repair processes. Section IV describes the current strategies for the treatment of radiation injury. Likely areas in which fruitful research might be performed are described in Section V. 495 references

  10. Chemical protection against ionizing radiation. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Livesey, J.C.; Reed, D.J.; Adamson, L.F.

    1984-08-01

    The scientific literature on radiation-protective drugs is reviewed. Emphasis is placed on the mechanisms involved in determining the sensitivity of biological material to ionizing radiation and mechanisms of chemical radioprotection. In Section I, the types of radiation are described and the effects of ionizing radiation on biological systems are reviewed. The effects of ionizing radiation are briefly contrasted with the effects of non-ionizing radiation. Section II reviews the contributions of various natural factors which influence the inherent radiosensitivity of biological systems. Inlcuded in the list of these factors are water, oxygen, thiols, vitamins and antioxidants. Brief attention is given to the model describing competition between oxygen and natural radioprotective substances (principally, thiols) in determining the net cellular radiosensitivity. Several theories of the mechanism(s) of action of radioprotective drugs are described in Section III. These mechanisms include the production of hypoxia, detoxication of radiochemical reactive species, stabilization of the radiobiological target and the enhancement of damage repair processes. Section IV describes the current strategies for the treatment of radiation injury. Likely areas in which fruitful research might be performed are described in Section V. 495 references.

  11. Inward propagating chemical waves in Taylor vortices.

    Science.gov (United States)

    Thompson, Barnaby W; Novak, Jan; Wilson, Mark C T; Britton, Melanie M; Taylor, Annette F

    2010-04-01

    Advection-reaction-diffusion (ARD) waves in the Belousov-Zhabotinsky reaction in steady Taylor-Couette vortices have been visualized using magnetic-resonance imaging and simulated using an adapted Oregonator model. We show how propagating wave behavior depends on the ratio of advective, chemical and diffusive time scales. In simulations, inward propagating spiral flamelets are observed at high Damköhler number (Da). At low Da, the reaction distributes itself over several vortices and then propagates inwards as contracting ring pulses--also observed experimentally.

  12. Synchrotron radiation facilities for chemical applications

    International Nuclear Information System (INIS)

    Hatano, Yoshihiko

    1995-01-01

    Synchrotron radiation (SR) research is of great importance in understanding radiation chemistry, physics, and biology. It is also clearly recognized in the international chemical community that chemical applications of SR are greatly advanced and divided into 1) Molecular Spectroscopy and Dynamics Studies-Gases, Surfaces, and Condensed Matter- , 2) Radiation Chemistry and Photochemistry, 3) X-ray Structural and XAFS Studies-Crystals, Surfaces, and Liquids- , 4) Analytical Chemistry, and 5) Synthesis or R and D of New Materials. In this paper, a survey is given of recent advances in the application of SR to the chemistry of excitation and ionization of molecules, i.e., SR chemistry, in the wavelength region between near-ultraviolet and hard X-rays. The topics will be chosen from those obtained at some leading SR facilities. (J.P.N.)

  13. Non-Directional Radiation Spread Modeling and Non-Invasive Estimating the Radiation Scattering and Absorption Parameters in Biological Tissue

    Directory of Open Access Journals (Sweden)

    S. Yu. Makarov

    2015-01-01

    Full Text Available The article dwells on a development of new non-invasive measurement methods of optical parameters of biological tissues, which are responsible for the scattering and absorption of monochromatic radiation. It is known from the theory of radiation transfer [1] that for strongly scattering media, to which many biological tissues pertain, such parameters are parameters of diffusion approximation, as well as a scattering coefficient and an anisotropy parameter.Based on statistical modeling the paper examines a spread of non-directional radiation from a Lambert light beam with the natural polarization that illuminates a surface of the biological tissue. Statistical modeling is based on the Monte Carlo method [2]. Thus, to have the correct energy coefficient values of Fresnel reflection and transmission in simulation of such radiation by Monte Carlo method the author uses his finding that is a function of the statistical representation for the incidence of model photons [3]. The paper describes in detail a principle of fixing the power transmitted by the non-directional radiation into biological tissue [3], and the equations of a power balance in this case.Further, the paper describes the diffusion approximation of a radiation transfer theory, often used in simulation of radiation propagation in strongly scattering media and shows its application in case of fixing the power transmitted into the tissue. Thus, to represent an uneven power distribution is used an approximating expression in conditions of fixing a total input power. The paper reveals behavior peculiarities of solution on the surface of the biological tissue inside and outside of the incident beam. It is shown that the solution in the region outside of the incident beam (especially far away from it, essentially, depends neither on the particular power distribution across the surface, being a part of the tissue, nor on the refractive index of the biological tissue. It is determined only by

  14. Radiation chemistry in development and research of radiation biology

    International Nuclear Information System (INIS)

    Min Rui

    2010-01-01

    During the establishment and development of radiation biology, radiation chemistry acts like bridge which units the spatial and temporal insight coming from radiation physics with radiation biology. The theory, model, and methodology of radiation chemistry play an important role in promoting research and development of radiation biology. Following research development of radiation biology effects towards systems radiation biology the illustration and exploration both diversity of biological responses and complex process of biological effect occurring remain to need the theory, model, and methodology come from radiation chemistry. (authors)

  15. Radiobiology: Biologic effects of ionizing radiations

    International Nuclear Information System (INIS)

    Held, K.D.

    1987-01-01

    The biologic effects after exposure to ionizing radiation, such as cell death or tissue injury, result from a chain of complex physical, chemical, metabolic, and histologic events. The time scale of these radiation actions spans many orders of magnitude. The physical absorption of ionizing radiation occurs in about 10 -18 s, while late carcinogenic and genetic effects are expressed years or even generations later. Collectively, these effects form the science of radiobiology. Many of the concepts discussed in this chapter have been developed through the study of effects generated in tissues by external radiation sources, but they apply generally and often specifically to internally distributed radiopharmaceuticals which form the central topic of this book

  16. Physical and chemical changes in water pollutants caused by ionizing radiations

    International Nuclear Information System (INIS)

    Vacek, K.

    1978-01-01

    Ionization and excitation as primary effects of ionizing radiation form secondary activated intermediary products (H and OH radicals and hydrated electrons esub(aq) - ) in water systems, which act on all in substances present in water. Physical and chemical changes speeding the sludge sedimentation in waste-water show complex dependences. It is, however, possible to prove them even at low radiation doses (0.07 to 0.35 kJ/kg). Chemical effects can be observed at higher radiation doses (1 to 10 kJ/kg) and are based on oxidative destruction of pollutants. Some of these reactions may be based on chain mechanisms (phenol oxidizing in water), but there are limited chances for application of these chain mechanisms in waste-water systems. Slight damage of biologically important macromolecules leads to changes, or even stops biological processes. Therefore, biological effects of ionizing radiation have the most remarkable impact. The utilization of these reactions in water management may be possible in suppressing biological ochration (ochre sedimentation) in wells and for ensuring hygienic conditions of sludge in waste-water processing for agrotechnical purposes. (author)

  17. AINSE conference on radiation biology and chemistry. Conference handbook

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1994-12-31

    The conference handbook contains 60 oral and poster presentations dealing with recent advances in radiation chemistry applied to biological studies, radiopharmaceuticals, radiosensitizers as well as to solid state chemical physics.

  18. AINSE conference on radiation biology and chemistry. Conference handbook

    International Nuclear Information System (INIS)

    1994-01-01

    The conference handbook contains 60 oral and poster presentations dealing with recent advances in radiation chemistry applied to biological studies, radiopharmaceuticals, radiosensitizers as well as to solid state chemical physics

  19. Radiation physics, biophysics and radiation biology. Progress report, October 1, 1980-September 30, 1981

    International Nuclear Information System (INIS)

    1981-07-01

    Separate abstracts were prepared for the 29 papers in this progress report which deal with radiobiological physics, the biological effects of ionizing radiations, and the modification of these effects by chemical and pharmacological agents

  20. Activation of chemical biological defense mechanisms and remission of vital oxidative injury by low dose radiation

    International Nuclear Information System (INIS)

    Yamaoka, K.; Nomura, T.; Kojima, S.

    2000-01-01

    Excessive active oxygen produced in vivo by various causes is toxic. Accumulation of oxidation injuries due to excessive active causes cell and tissue injuries, inducing various pathologic conditions such as aging and carcinogenesis. On the other hand, there are chemical defense mechanisms in the body that eliminate active oxygen or repair damaged molecules, defending against resultant injury. It is interesting reports that appropriate oxidation stress activate the chemical biological defense mechanisms. In this study, to elucidate these phenomena and its mechanism by low dose radiation, we studied on the below subjects. Activation of chemical biological defense mechanisms by low dose radiation: (1) The effects radiation on lipid peroxide (LPO) levels in the organs, membrane fluidity and the superoxide dismutase (SOD) activity were examined in rats and rabbits. Rats were irradiated with low dose X-ray over their entire bodies, and rabbits inhaled vaporized radon spring water, which primarily emitted α-ray. The following results were obtained. Unlike high dose X-ray, low dose X-ray and radon inhalation both reduced LPO levels and made the state of the SH-group on membrane-bound proteins closer to that of juvenile animals, although the sensitivity to radioactivity varied depending on the age of the animals and among different organs and tissues. The SOD activity was elevated, suggesting that low dose X-ray and radon both activate the host defensive function. Those changes were particularly marked in the organs related to immune functions of the animals which received low dose X-ray, while they were particularly marked in the brain after radon inhalation. It was also found that those changes continued for longer periods after low dose X-irradiation. (2) Since SOD is an enzyme that mediates the dismutation of O 2 - to H 2 O 2 , the question as to whether the resultant H 2 O 2 is further detoxicated into H 2 O and O 2 or not must still be evaluated. Hence, we studied

  1. Biological effects of radiation

    International Nuclear Information System (INIS)

    2013-01-01

    This fourth chapter presents: cell structure and metabolism; radiation interaction with biological tissues; steps of the production of biological effect of radiation; radiosensitivity of tissues; classification of biological effects; reversibility, transmissivity and influence factors; pre-natal biological effects; biological effects in therapy and syndrome of acute irradiation

  2. The mechanism for the primary biological effects of ionizing radiation

    International Nuclear Information System (INIS)

    Byakov, Vsevolod M; Stepanov, Sergei V

    2006-01-01

    The primary biological response of living organisms to the passage of fast charged particles is traditionally believed to be dominated by the chemical reactions of the radical products from the radiolysis of cellular water (OH, H, e aq - , O 2 - , H 2 O 2 ) and by the bioradicals that they produce (and which can also result from the direct electronic activation of biomolecules). This understanding has provided insight into how ionizing radiations affect biological systems and, most importantly, what radioprotection and radiosensibilizing effects are produced by chemical compounds introduced into an organism. However, a number of key radiobiological facts remain unexplained by the current theory, stimulating a search for other biologically active factors that may be triggered by radiation. This review examines a fact that is usually ignored in discussing the biological impact of ionizing radiation: the local increase in acidity in the water solution along the track of a charged particle. The acidity in the track is very different from its value for cellular water in a living organism. Biological processes are well-known to be highly sensitive to changes in the environmental acidity. It seems that the biological impact of ionizing radiations is dominated not by the water radiolysis products (mostly radicals) listed above but particles of a different nature, hydroxonium ions H 3 O + , where the term hydroxonium refer to protonated water molecules. This modification of the mechanism of primary radiobiological effects is in good agreement with experimental data. In particular, the extremal dependence of the relative biological efficiency (RBE) of radiations on their ionizing energy losses is accounted for in quantitative terms, as is the increase in the RBE in the relativistic energy range. (reviews of topical problems)

  3. Physics must join with biology in better assessing risk from low-dose irradiation

    International Nuclear Information System (INIS)

    Feinendegen, L. E.; Neumann, R. D.

    2005-01-01

    This review summarises the complex response of mammalian cells and tissues to low doses of ionising radiation. This thesis encompasses induction of DNA damage, and adaptive protection against both renewed damage and against propagation of damage from the basic level of biological organisation to the clinical expression of detriment. The induction of DNA damage at low radiation doses apparently is proportional to absorbed dose at the physical/chemical level. However, any propagation of such damage to higher levels of biological organisation inherently follows a sigmoid function. Moreover, low-dose-induced inhibition of damage propagation is not linear, but instead follows a dose-effect function typical for adaptive protection, after an initial rapid rise it disappears at doses higher than ∼0.1-0.2 Gy to cells. The particular biological response duality at low radiation doses precludes the validity of the linear-no-threshold hypothesis in the attempt to relate absorbed dose to cancer. In fact, theory and observation support not only a lower cancer incidence than expected from the linear-no-threshold hypothesis, but also a reduction of spontaneously occurring cancer, a hormetic response, in the healthy individual. (authors)

  4. Radiation and propagation of electromagnetic waves

    CERN Document Server

    Tyras, George; Declaris, Nicholas

    1969-01-01

    Radiation and Propagation of Electromagnetic Waves serves as a text in electrical engineering or electrophysics. The book discusses the electromagnetic theory; plane electromagnetic waves in homogenous isotropic and anisotropic media; and plane electromagnetic waves in inhomogenous stratified media. The text also describes the spectral representation of elementary electromagnetic sources; the field of a dipole in a stratified medium; and radiation in anisotropic plasma. The properties and the procedures of Green's function method of solution, axial currents, as well as cylindrical boundaries a

  5. Generation and propagation of synchro - Cherenkov radiation

    International Nuclear Information System (INIS)

    Heintzmann, H.; Novello, M.; Schruefer, E.

    1981-01-01

    Particles moving along the magnetic field lines emit under favorable conditions Cherenkov radiation in a cold, rarefied plasma. A peculiar phenomenon occurs for curved magnetic fields: in for example a toroidal magnetic field the radiation spirals inward and approaches a resonance. Both the generation and the study of the propagation of these Cherenkov modes appear to be within reach of present technology. (Author) [pt

  6. Terrorist threat, chemical, biological, radiological, nuclear medical approach

    International Nuclear Information System (INIS)

    Revel, Th. de; Gourmelon, P.; Vidal, D.; Renaudeau, C.

    2005-01-01

    The different aspects linked to the use of nuclear, radiological, biological and or chemical weapons are gathered in this work. They concern history, fundamental aspect, diagnosis, therapy and prevention. The part devoted to the nuclear aspect concern the accidents in relation with ionizing radiations, the radiation syndrome, the contribution and limits of dosimetry, the treatment of medullary aplasia, the evaluation and treatment of an internal contamination, new perspectives on the use of cytokine for the treatment of accidental irradiated persons, alternative to the blood transfusion. (N.C.)

  7. Chain radiation-chemical oxidation of aromatic amines in polyvinylchloride films

    International Nuclear Information System (INIS)

    Kolninov, O.V.; Lisovskaya, I.A.; Milinchuk, V.K.

    1983-01-01

    Radiation-chemical oxidation of tetramethyldiaminediphenylmethane in polyvinylchloride (PVC) and polystyrene (PS) films was investigated in the presence of CBr 4 at 300 K. Radiation yields (G) of 70 and 1 were obtained for an oxidized amine form (Am + ) in PVC and PS, resp. High yields of Am + in PVC matrix indicate the chain character of an oxidation reaction. Triplet states, which form exciplexes with CBr 4 were established to participate in oxidation reactions. The kinetic scheme suggested for the chain radiation oxidation of Am takes into account energy transfer, formation and degradation of the excited states of molecules resulting in the initiation and propagation of the chain on the account of active particles. (author)

  8. Clinical oncology based upon radiation biology

    International Nuclear Information System (INIS)

    Hirata, Hideki

    2016-01-01

    This paper discussed the biological effects of radiation as physical energy, especially those of X-ray as electromagnetic radiation, by associating the position of clinical oncology with classical radiation cell biology as well as recent molecular biology. First, it described the physical and biological effects of radiation, cell death due to radiation and recovery, radiation effects at tissue level, and location information and dosage information in the radiotherapy of cancer. It also described the territories unresolved through radiation biology, such as low-dose high-sensitivity, bystander effects, etc. (A.O.)

  9. Computational Systems Chemical Biology

    OpenAIRE

    Oprea, Tudor I.; May, Elebeoba E.; Leitão, Andrei; Tropsha, Alexander

    2011-01-01

    There is a critical need for improving the level of chemistry awareness in systems biology. The data and information related to modulation of genes and proteins by small molecules continue to accumulate at the same time as simulation tools in systems biology and whole body physiologically-based pharmacokinetics (PBPK) continue to evolve. We called this emerging area at the interface between chemical biology and systems biology systems chemical biology, SCB (Oprea et al., 2007).

  10. Biological effects of particle radiation

    International Nuclear Information System (INIS)

    Sakamoto, Kiyohiko

    1988-01-01

    Conventional radiations such as photons, gamma rays or electrons show several physical or biological disadvantages to bring tumors to cure, therefore, more and more attentions is being paid to new modalitie such as fast neutrons, protons, negative pions and heavy ions, which are expected to overcome some of the defects of the conventional radiations. Except for fast neutrons, these particle radiations show excellet physical dose localization in tissue, moreover, in terms of biological effects, they demonstrate several features compared to conventional radiations, namely low oxygen enhancement ratio, high value of relative biological effectiveness, smaller cellular recovery, larger therapeutic gain factor and less cell cycle dependency in radiation sensitivity. In present paper the biological effects of particle radiations are shown comparing to the effects of conventional radiations. (author)

  11. Routine medicare and radiation exposure (3) biology about radiation exposure for its understanding

    International Nuclear Information System (INIS)

    Saito, Tsutomu; Hirata, Hideki

    2013-01-01

    Radiation-induced biological responses are easily explained as follows. The process of cancer formation is on the hypothesis of multi-step carcinogenesis of the initiation, promotion and progression. Radiation is an exogenous physical initiator. Physical process of ionization in biomaterials by radiation occurs within the time of 10 -12 sec order, which resulting in chemical process (10 -6 sec) leading to tissue response or to cancerous change (several tens hours to several decades). Direct and indirect effects on DNA are yielded with the high LET (linear energy transfer) radiation and low, through OH-radical formation, respectively. Double strand break of DNA induced by radiation is repaired by the error-free homologous recombination or error-prone non-homologous end-joining. At the early phase of the damage, DNA damage response begins to work for repairing, and when the response is inoperable, cellular response is induced to lead radiation apoptosis as an exclusion mechanism of abnormal cells. The biological effects differ even at the same dose of different radiations when their LET is different, and relative biological effectiveness (RBE) is used. For correction of the stochastic radiation effect, the radiation weighting factor (W R ) is used for conversion to the single photon beam dose that ICRP defines as the equivalent dose (H T , Sv). ICRP (Pub. 103) also recommends the use of RBE (Gy) for the definitive effect. Radiation effects are known to be modified by such phenomena as the bystander effect, cluster damage of DNA, radiation adaptation, hormesis, dose rate effect and non-tumor inducing dose. ICRP employs linear non-threshold (LNT) hypothesis for low dose and low dose rate carcinogenesis. (T.T.)

  12. Biology of ionizing radiation effects

    International Nuclear Information System (INIS)

    Ferradini, C.; Pucheault, J.

    1983-01-01

    The present trends in biology of ionizing radiation are reviewed. The following topics are investigated: interaction of ionizing radiations with matter; the radiolysis of water and aqueous solutions; properties of the free radicals intervening in the couples O 2 /H 2 O and H 2 O/H 2 ; radiation chemistry of biological compounds; biological effects of ionizing radiations; biochemical mechanisms involving free radicals as intermediates; applications (biotechnological applications, origins of life) [fr

  13. Efficiency of interaction between various radiation and chemicals

    International Nuclear Information System (INIS)

    Kim, Jin Kyu; Song, H. S.; Kim, J. S.; Chun, K. J.; Lee, Y. K.; Lee, B. H.; Shin, H. S.; Lee, K. H.; Petin, Vladislav G.

    2002-01-01

    KAERI and INP (Poland) have been carried out parallel study and joint experiments on the major topics according to MOU about their cooperative project. Major experimental techniques were TSH assay, comet assay, and synergism assay. The research consisted of the following workscopes. 1) Application of TSH bioindicator for studying the biological efficiency of radiation, 2) Relative biological efficiency of californium-252 neutrons in the induction of gene and lethal mutations in TSH cells normal and enriched with boron compound, 3) Effect of pesticide on radiation-induced mutations in TSH cells, 4) Interaction of radiation with pesticide on DNA damage in human peripheral blood lymphocytes, 5) Radiomodifying effect of boron and gadolinium compounds in human peripheral blood lymphocytes, 6) Mathematical description of synergistic interactions, 7) General regularities of synergistic interactions, and 8) Determinant of synergistic interaction between radiation, heat and chemicals in cell killing. Both institutes have established wide variety of research techniques applicable to various radiation research through the cooperation. The results of research can make the role of fundamental basis for the better relationship between Korea and Poland

  14. A Hypothesis on Biological Protection from Space Radiation Through the Use of New Therapeutic Gases

    Science.gov (United States)

    Schoenfeld, Michael P.; Ansari, Rafat R.; Nakao, Atsunori; Wink, David

    2011-01-01

    Radiation exposure to astronauts could be a significant obstacle for long duration manned space exploration because of current uncertainties regarding the extent of biological effects. Furthermore, concepts for protective shielding also pose a technically challenging issue due to the nature of cosmic radiation and current mass and power constraints with modern exploration technology. The concern regarding exposure to cosmic radiation is the biological damage it induces. As damage is associated with increased oxidative stress, it is important and would be enabling to mitigate and/or prevent oxidative stress prior to the development of clinical symptoms and disease. This paper hypothesizes a "systems biology" approach in which a combination of chemical and biological mitigation techniques are used conjunctively. It proposes using new, therapeutic, medical gases as both chemical radioprotectors for radical scavenging and biological signaling molecules for management of the body s response to exposure. From reviewing radiochemistry of water, biological effects of CO, H2, NO, and H2S gas, and mechanisms of radiation biology, it is concluded that this approach may have great therapeutic potential for radiation exposure. Furthermore, it also appears to have similar potential for curtailing the pathogenesis of other diseases in which oxidative stress has been implicated including cardiovascular disease, cancer, chronic inflammatory disease, hypertension, ischemia/reperfusion injury, acute respiratory distress syndrome, Parkinson s and Alzheimer s disease, cataracts, and aging.

  15. Review of domestic radiation biology research

    International Nuclear Information System (INIS)

    Zheng Chun; Song Lingli; Ai Zihui

    2011-01-01

    Radiation biology research in China during the past ten years are reviewed. It should be noticed that radiation-biology should focus on microdosimetry, microbeam application, and radiation biological mechanism. (authors)

  16. Radiation and propagation of short acoustical pulses from underground explosions

    International Nuclear Information System (INIS)

    Banister, J.R.

    1982-06-01

    Radiation and propagation of short acoustical pulses from underground nuclear explosions were analyzed. The cone of more intense radiation is defined by the ratio of sound speeds in the ground and air. The pressure history of the radiated pulse is a function of the vertical ground-motion history, the range, the burial depth, and the velocity of longitudinal seismic waves. The analysis of short-pulse propagation employed an N-wave model with and without enegy conservation. Short pulses with initial wave lengths less than 100 m are severely attenuated by the energy loss in shocks and viscous losses in the wave interior. The methods developed in this study should be useful for system analysis

  17. Generalized Beer-Lambert model for near-infrared light propagation in thick biological tissues

    Science.gov (United States)

    Bhatt, Manish; Ayyalasomayajula, Kalyan R.; Yalavarthy, Phaneendra K.

    2016-07-01

    The attenuation of near-infrared (NIR) light intensity as it propagates in a turbid medium like biological tissue is described by modified the Beer-Lambert law (MBLL). The MBLL is generally used to quantify the changes in tissue chromophore concentrations for NIR spectroscopic data analysis. Even though MBLL is effective in terms of providing qualitative comparison, it suffers from its applicability across tissue types and tissue dimensions. In this work, we introduce Lambert-W function-based modeling for light propagation in biological tissues, which is a generalized version of the Beer-Lambert model. The proposed modeling provides parametrization of tissue properties, which includes two attenuation coefficients μ0 and η. We validated our model against the Monte Carlo simulation, which is the gold standard for modeling NIR light propagation in biological tissue. We included numerous human and animal tissues to validate the proposed empirical model, including an inhomogeneous adult human head model. The proposed model, which has a closed form (analytical), is first of its kind in providing accurate modeling of NIR light propagation in biological tissues.

  18. Advances in radiation biology

    International Nuclear Information System (INIS)

    Lett, J.T.; Ehmann, U.K.; Cox, A.B.

    1987-01-01

    The classical period of radiation biology is coming to a close. Such change always occurs at a time when the ideas and concepts that promoted the burgeoning of an infant science are no longer adequate. This volume covers a number of areas in which new ideas and research are playing a vital role, including cellular radiation sensitivity, radioactive waste disposal, and space radiation biology

  19. Biological radiation effects

    International Nuclear Information System (INIS)

    Koggl, D.; Dedenkov, A.N.

    1986-01-01

    All nowadays problems of radio biology are considered: types of ionizing radiations, their interaction with material; damage of molecular structures and their reparation; reaction of cells and their recovery from radiation damage; reaction of the whole organism and its separate systems. Particular attention is given to the problems of radiation carcinogenesis and radiation hazard for man

  20. Human Genetic Marker for Resistance to Radiation and Chemicals

    International Nuclear Information System (INIS)

    Lieberman, Howard B.

    2001-01-01

    TO characterize the human HRDAD9 gene and evaluate its potential as a biomarker to predict susceptibility to the deleterious health effects potentially caused by exposure to radiations or chemicals present at DOE hazardous waste cleanup sites. HRAD9 is a human gene that is highly conserved throughout evolution. Related genes have been isolated from yeasts and mice, underscoring its biological significance. Most of our previous work involved characterization of the yeast gene cognate, wherein it was determined that the corresponding protein plays a significant role in promoting resistance of cells to radiations and chemicals, and in particular, controlling cell growth in response to DNA damage

  1. Pilot-industrial plant for radiation-chemical finishing of textiles

    International Nuclear Information System (INIS)

    Burov, V.K.; Vanyushkin, B.M.; Voskoboev, A.E.

    1976-01-01

    A pilot technological radiational-chemical line for liquid-phase radiational-chemical finish of fabrics is described, which is being mounted at the Glukhov cotton group of enterprises now. It is designed primarily for the anti-microbe finish of cotton fabrics by grafting copper polyacrylate. The technological scheme is built on the principle of direct (combined) irradiation of the fabric impregnated by a monomer solution. Graft of the monomer to the fabric is performed by the radiational method. As source of radiation, an electron accelerator with the beam power of 0.4-0.7 Mev and with a biological protection has been employed. Depending on the thickness of the material irradiated and irradiation conditions, the fabric drive mechanism permits to change a number of irradiated fabric layers from 1 to 9 and by this to utilize in the most complete manner the energy of the accelerated electron beam. The nominal width of the irradiated material is 1000 m, the transportation velocity can vary in the range from 10 through 100 m/min. The radiational-chemical method of fabric finish is economical, highly productive and easily controllable

  2. Assessment of the biological effects of 'strange' radiation

    International Nuclear Information System (INIS)

    Pryakhin, E.A.; Tryapitsina, G.A.; Urutskoyev, L.I.; Akleyev, A.V.

    2006-01-01

    The results from studies of the effects produced by electrical explosions of foils made from super pure materials in water point to the emergence of new chemical elements. An additional finding was the discharge of 'strange' radiation accompanying the transformation of chemical elements. However, currently, the mechanism involved in the interaction between 'strange' radiation and a substance or a biological entity remains obscure. Therefore, the aim of the present research is to investigate the biological effects of the 'strange' radiation. Pilot studies were performed at the RECOM RRC 'Kurchatov Institute' in April-May of 2004. The animals used in the experiment were female mice of C57Bl/6 line aged 80 days with body weight 16-18 g. The animals were exposed to radiation discharged during explosions of Ti foils in water and aqueous solutions. The cages with animals were placed at 1 m from the epicenter of the explosion. Explosions were carried out on the 19. (3 explosions), 20. (4 explosions) and 22. (3 explosions) of April, 2004 (explosions No1373 - No1382, respectively). The animals were assigned to 4 experimental groups comprised of 17-20 mice per group. The animals received experimental exposure within 1, 2 and 3 days of the experiment. In total, the experimental groups were exposed to 3, 7 and 10 explosions, respectively. In order to identify the biological reactions, the following parameters were estimated: number of nucleated cells in the bone marrow, number of CFU in the spleen after additional gamma-irradiation (6 Gy), cell composition of the bone marrow, the rate of erythrocytes with the different level of maturation in the bone marrow, the rate of erythrocytes with the micronuclei in the bone marrow, the reaction of bone marrow cells to additional gamma-irradiation (2 Gy), number of leucocytes in the peripheral blood, and cell composition of the peripheral blood. The following conclusions were drawn from these studies: 1. 'strange' radiation resulting

  3. Biological research for the radiation protection

    International Nuclear Information System (INIS)

    Kim, In Gyu; Kim, Chan Kug; Shim, Hae Won; Jung, Il Lae; Byun, Hee Sun; Moon, Myung Sook; Cho, Hye Jeong; Kim, Jin Sik

    2003-04-01

    The work scope of 'Biological Research for the Radiation Protection' had contained the research about polyamine effect on cell death triggered ionizing radiation, H 2 O 2 and toxic agents. In this paper, to elucidate the role of polyamines as mediator in lysosomal damage and stress(H 2 O 2 )- induced apoptosis, we utilized α-DiFluoroMethylOrnithine (DFMO), which inhibited ornithine decarboxylase and depleted intracellular putrescine, and investigated the effects of polyamine on the apoptosis caused by H 2 O 2 , ionizing radiation and paraquat. We also showed that MGBG, inhibitor of polyamine biosynthesis, treatment affected intracellular redox steady states, intracellular ROS levels and protein oxidation. Thereafter we also investigated whether MGBG may enhance the cytotoxic efficacy of tumor cells caused by ionizing radiation or H 2 O 2 because such compounds are able to potentiate the cell-killing effects. In addition, ceruloplasmin and thioredoxin, possible antioxidant proteins, were shown to have protective effect on radiation- or H 2 O 2 (or chemicals)-induced macromolecular damage or cell death

  4. Integrative Chemical-Biological Read-Across Approach for Chemical Hazard Classification

    Science.gov (United States)

    Low, Yen; Sedykh, Alexander; Fourches, Denis; Golbraikh, Alexander; Whelan, Maurice; Rusyn, Ivan; Tropsha, Alexander

    2013-01-01

    Traditional read-across approaches typically rely on the chemical similarity principle to predict chemical toxicity; however, the accuracy of such predictions is often inadequate due to the underlying complex mechanisms of toxicity. Here we report on the development of a hazard classification and visualization method that draws upon both chemical structural similarity and comparisons of biological responses to chemicals measured in multiple short-term assays (”biological” similarity). The Chemical-Biological Read-Across (CBRA) approach infers each compound's toxicity from those of both chemical and biological analogs whose similarities are determined by the Tanimoto coefficient. Classification accuracy of CBRA was compared to that of classical RA and other methods using chemical descriptors alone, or in combination with biological data. Different types of adverse effects (hepatotoxicity, hepatocarcinogenicity, mutagenicity, and acute lethality) were classified using several biological data types (gene expression profiling and cytotoxicity screening). CBRA-based hazard classification exhibited consistently high external classification accuracy and applicability to diverse chemicals. Transparency of the CBRA approach is aided by the use of radial plots that show the relative contribution of analogous chemical and biological neighbors. Identification of both chemical and biological features that give rise to the high accuracy of CBRA-based toxicity prediction facilitates mechanistic interpretation of the models. PMID:23848138

  5. Mechanically driven interface propagation in biological tissues

    International Nuclear Information System (INIS)

    Ranft, Jonas; Joanny, Jean-François; Aliee, Maryam; Jülicher, Frank; Prost, Jacques

    2014-01-01

    Many biological tissues consist of more than one cell type. We study the dynamics of an interface between two different cell populations as it occurs during the growth of a tumor in a healthy host tissue. Recent work suggests that the rates of cell division and cell death are under mechanical control, characterized by a homeostatic pressure. The difference in the homeostatic pressures of two cell types drives the propagation of the interface, corresponding to the invasion of one cell type into the other. We derive a front propagation equation that takes into account the coupling between cell number balance and tissue mechanics. We show that in addition to pulled fronts, pushed-front solutions occur as a result of convection driven by mechanics. (paper)

  6. Radiation physics, biophysics, and radiation biology

    International Nuclear Information System (INIS)

    Hall, E.J.; Zaider, M.

    1993-05-01

    Research at the Center for Radiological Research is a multidisciplenary blend of physics, chemistry and biology aimed at understanding the mechanisms involved in the health problems resulting from human exposure to ionizing radiations. The focus is increased on biochemistry and the application of the techniques of molecular biology to the problems of radiation biology. Research highlights of the program from the past year are described. A mathematical model describing the production of single-strand and double-strand breaks in DNA as a function radiation quality has been completed. For the first time Monte Carlo techniques have been used to obtain directly the spatial distribution of DNA moieties altered by radiation. This information was obtained by including the transport codes a realistic description of the electronic structure of DNA. We have investigated structure activity relationships for the potential oncogenicity of a new generation of bioreductive drugs that function as hypoxic cytotoxins. Experimental and theoretical investigation of the inverse dose rate effect, whereby medium LET radiations actually produce an c effect when the dose is protracted, is now at a point where the basic mechanisms are reasonably understood and the complex interplay between dose, dose rate and radiation quality which is necessary for the effect to be present can now be predicted at least in vitro. In terms of early radiobiological damage, a quantitative link has been established between basic energy deposition and locally multiply damaged sites, the radiochemical precursor of DNA double strand breaks; specifically, the spatial and energy deposition requirements necessary to form LMDs have been evaluated. For the first time, a mechanically understood ''biological fingerprint'' of high-LET radiation has been established. Specifically measurement of the ratio of inter-to intra-chromosomal aberrations produces a unique signature from alpha-particles or neutrons

  7. Radiation physics, biophysics, and radiation biology

    Energy Technology Data Exchange (ETDEWEB)

    Hall, E.J.; Zaider, M.

    1993-05-01

    Research at the Center for Radiological Research is a multidisciplenary blend of physics, chemistry and biology aimed at understanding the mechanisms involved in the health problems resulting from human exposure to ionizing radiations. The focus is increased on biochemistry and the application of the techniques of molecular biology to the problems of radiation biology. Research highlights of the program from the past year are described. A mathematical model describing the production of single-strand and double-strand breaks in DNA as a function radiation quality has been completed. For the first time Monte Carlo techniques have been used to obtain directly the spatial distribution of DNA moieties altered by radiation. This information was obtained by including the transport codes a realistic description of the electronic structure of DNA. We have investigated structure activity relationships for the potential oncogenicity of a new generation of bioreductive drugs that function as hypoxic cytotoxins. Experimental and theoretical investigation of the inverse dose rate effect, whereby medium LET radiations actually produce an c effect when the dose is protracted, is now at a point where the basic mechanisms are reasonably understood and the complex interplay between dose, dose rate and radiation quality which is necessary for the effect to be present can now be predicted at least in vitro. In terms of early radiobiological damage, a quantitative link has been established between basic energy deposition and locally multiply damaged sites, the radiochemical precursor of DNA double strand breaks; specifically, the spatial and energy deposition requirements necessary to form LMDs have been evaluated. For the first time, a mechanically understood biological fingerprint'' of high-LET radiation has been established. Specifically measurement of the ratio of inter-to intra-chromosomal aberrations produces a unique signature from alpha-particles or neutrons.

  8. Physico-chemical studies of radiation effects in cells: Final report

    International Nuclear Information System (INIS)

    Powers, E.L.

    1987-03-01

    The career of Dr. E.L. Powers, a pioneer in the development of radiobiology, is reviewed. His initial research involved the effects of radiation and certain chemicals on Paramecium, associated ultrastructural studies on protozoan cells, responses of Rickettsia and bacteriophage to irradiation, and the development of techniques for studying bacterial spores. These efforts established the basic radiation biology of the spore and its importance in understanding the effects of free radicals, oxygen, and water. His recent research extended work on the dry spore to the very wet spore and to other selected chemical systems in aqueous suspension. 126 refs., 2 figs

  9. The biological effects of low doses of radiation: medical, biological and ecological aspects

    International Nuclear Information System (INIS)

    Gun-Aajav, T.; Ajnai, L.; Manlaijav, G.

    2007-01-01

    Full text: The results of recent studies show that low doses of radiation make many different structural and functional changes in a cell and these changes are preserved for a long time. This phenomenon is called as effects of low doses of radiation in biophysics, radiation biology and radiation medicine. The structural and functional changes depend on doses and this dependence has non-linear and bimodal behaviour. More detail, the radiation effect goes up and reaches its maximum (Low doses maximum) in low doses region, then it goes down and takes its stationary means (there is a negative effect in a few cases). With increases in doses and with further increases it goes up. It is established that low dose's maximum depends on physiological state of a biological object, radiation quality and dose rate. During the experiments another special date was established. This specialty is that many different physical and chemical factors are mutually connected and have synergetic behaviour. At present, researches are concentrating their attention on the following three directions: 1. Direct and indirect interaction of radiation's low doses: 2. Interpretation of its molecular mechanism, regulation of the positive effects and elaboration of ways o removing negative effects: 3. Application of the objective research results into practice. In conclusion the authors mention the current concepts on interpretation of low doses effect mechanism, forward their own views and emphasize the importance of considering low doses effects in researches of environmental radiation pollution, radiation medicine and radiation protection. (author)

  10. Research progress on space radiation biology

    International Nuclear Information System (INIS)

    Li Wenjian; Dang Bingrong; Wang Zhuanzi; Wei Wei; Jing Xigang; Wang Biqian; Zhang Bintuan

    2010-01-01

    Space radiation, particularly induced by the high-energy charged particles, may cause serious injury on living organisms. So it is one critical restriction factor in Manned Spaceflight. Studies have shown that the biological effects of charged particles were associated with their quality, the dose and the different biological end points. In addition, the microgravity conditions may affect the biological effects of space radiation. In this paper we give a review on the biological damage effects of space radiation and the combined biological effects of the space radiation coupled with the microgravity from the results of space flight and ground simulation experiments. (authors)

  11. Radiation biology for the non-biologist

    International Nuclear Information System (INIS)

    Myers, D.K.

    1978-06-01

    This colloquium introduces some of the general concepts used in cell biology and in the study of the effects of ionizing radiation on living organisms. The present research activities in radiation biology in the Biology Branch at the Chalk River Nuclear Laboratories cover a broad range of interests in the entire chain of events by which the initial radiation-induced changes in the living cell are translated into significant biological effects, including the eventual production of cancers and hereditary defects. The main theme of these research activities is an understanding of the mechanisms by which radiation damage to DNA (the carrier of hereditary information in all living organisms) can be actively repaired by the living cell. Advances in our understanding of these processes have broad implications for other areas of biology but also bear directly on the assessment of the biological hazards of ionizing radiation. The colloquium concludes with a brief discussion of the hazards of low-level radiation. (author)

  12. Biological monitoring of radiation exposure

    Science.gov (United States)

    Horneck, G.

    1998-11-01

    Complementary to physical dosimetry, biological dosimetry systems have been developed and applied which weight the different components of environmental radiation according to their biological efficacy. They generally give a record of the accumulated exposure of individuals with high sensitivity and specificity for the toxic agent under consideration. Basically three different types of biological detecting/monitoring systems are available: (i) intrinsic biological dosimeters that record the individual radiation exposure (humans, plants, animals) in measurable units. For monitoring ionizing radiation exposure, in situ biomarkers for genetic (e.g. chromosomal aberrations in human lymphocytes, germ line minisatellite mutation rates) or metabolic changes in serum, plasma and blood (e.g. serum lipids, lipoproteins, lipid peroxides, melatonin, antibody titer) have been used. (ii) Extrinsic biological dosimeters/indicators that record the accumulated dose in biological model systems. Their application includes long-term monitoring of changes in environmental UV radiation and its biological implications as well as dosimetry of personal UV exposure. (iii) Biological detectors/biosensors for genotoxic substances and agents such as bacterial assays (e.g. Ames test, SOS-type test) that are highly sensitive to genotoxins with high specificity. They may be applicable for different aspects in environmental monitoring including the International Space Station.

  13. Approaches to chemical synthetic biology.

    Science.gov (United States)

    Chiarabelli, Cristiano; Stano, Pasquale; Anella, Fabrizio; Carrara, Paolo; Luisi, Pier Luigi

    2012-07-16

    Synthetic biology is first represented in terms of two complementary aspects, the bio-engineering one, based on the genetic manipulation of extant microbial forms in order to obtain forms of life which do not exist in nature; and the chemical synthetic biology, an approach mostly based on chemical manipulation for the laboratory synthesis of biological structures that do not exist in nature. The paper is mostly devoted to shortly review chemical synthetic biology projects currently carried out in our laboratory. In particular, we describe: the minimal cell project, then the "Never Born Proteins" and lastly the Never Born RNAs. We describe and critically analyze the main results, emphasizing the possible relevance of chemical synthetic biology for the progress in basic science and biotechnology. Copyright © 2012 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.

  14. Biological radiation effects

    International Nuclear Information System (INIS)

    Gomes, R.A.

    1976-01-01

    The stages of processes leading to radiation damage are studied, as well as, the direct and indirect mechanics of its production. The radiation effects on nucleic acid and protein macro moleculas are treated. The physical and chemical factors that modify radiosensibility are analysed, in particular the oxygen effects, the sensibilization by analogues of nitrogen bases, post-effects, chemical protection and inherent cell factors. Consideration is given to restoration processes by excision of injured fragments, the bloching of the excision restoration processes, the restoration of lesions caused by ionizing radiations and to the restoration by genetic recombination. Referring to somatic effects of radiation, the early ones and the acute syndrome of radiation are discussed. The difference of radiosensibility observed in mammalian cells and main observable alterations in tissues and organs are commented. Referring to delayed radiation effects, carcinogeneses, alterations of life span, effects on growth and development, as well as localized effects, are also discussed [pt

  15. Confronting actual influence of radiation on human bodies and biological defense mechanism

    International Nuclear Information System (INIS)

    Matsubara, Junko

    2012-01-01

    After the accident at Fukushima Daiichi Nuclear Power Plant of Tokyo Electric Power Company, social, economical, psychological pressures on local residents and fears of radiation among the general public have not been resolved. Based on the assumption that the negligence of specialists to clearly explain the influence of radiation on human bodies to the general public is the factor for above mentioned pressures and fears, the influence of radiation from a realistic view was discussed. The topics covered are: (1) understanding the meaning of radiation regulation, (2) radiation and threshold values, (3) actual influence of low-dose radiation, (4) chemical and biological defense in defense mechanism against radiation, (5) problems raised by Fukushima Daiichi nuclear accident. Furthermore, the article explains the principles and the applications of biological defense function activation, and suggested that self-help efforts to fight against stress are from now on. (S.K.)

  16. Average intensity and spreading of partially coherent model beams propagating in a turbulent biological tissue

    International Nuclear Information System (INIS)

    Wu, Yuqian; Zhang, Yixin; Wang, Qiu; Hu, Zhengda

    2016-01-01

    For Gaussian beams with three different partially coherent models, including Gaussian-Schell model (GSM), Laguerre-Gaussian Schell-model (LGSM) and Bessel-Gaussian Schell-model (BGSM) beams propagating through a biological turbulent tissue, the expression of the spatial coherence radius of a spherical wave propagating in a turbulent biological tissue, and the average intensity and beam spreading for GSM, LGSM and BGSM beams are derived based on the fractal model of power spectrum of refractive-index variations in biological tissue. Effects of partially coherent model and parameters of biological turbulence on such beams are studied in numerical simulations. Our results reveal that the spreading of GSM beams is smaller than LGSM and BGSM beams on the same conditions, and the beam with larger source coherence width has smaller beam spreading than that with smaller coherence width. The results are useful for any applications involved light beam propagation through tissues, especially the cases where the average intensity and spreading properties of the light should be taken into account to evaluate the system performance and investigations in the structures of biological tissue. - Highlights: • Spatial coherence radius of a spherical wave propagating in a turbulent biological tissue is developed. • Expressions of average intensity and beam spreading for GSM, LGSM and BGSM beams in a turbulent biological tissue are derived. • The contrast for the three partially coherent model beams is shown in numerical simulations. • The results are useful for any applications involved light beam propagation through tissues.

  17. Radiation-chemical degradation of chloroform in water solutions

    International Nuclear Information System (INIS)

    Ahmadov, S.A; Gurbanov, M.A; Iskenderova, Z.I; Abdullaev, E.T; Ibadov, N.A.

    2006-01-01

    Full text: Chloroform is the major chlorine-containing compound forming at chlorination of drinking water. As our basic water resources of Kur and Araz rivers are mostly polluted along the territory of the neighbor republics their chlorination for the purpose of biological purification can result in forming of chloroform. Unfortunately, there are only poor data about containing of chloroform in drinking water in the Republic, however the particular problem is to develop new methods of drinking water purification from chloroform, taking into account the high toxicity of this compounds. Appropriate works indicate that radiation-chemical processing can mostly reduce the concentration of chloroform in drinking water. The purification degree can achieve 95-98%. This work studies the tendency of chloroform decomposition at its radiolysis processes in percentage. Taking into account the dissolvability of chloroform in water solutions it can be said that examined water solutions are homogeneous. Following advancements are studied: b Determination of radiation-chemical yield of chloroform decomposition at its various initial concentrations;Impact of adsorbed dose on pH of solutions;Formation of by-products.It is set that radiation-chemical output of chloroform decomposition is equal to 3.10-3-125 mol 100ev.

  18. Ionizing radiation biological effects and the proper protective measures against it's harmful effects

    International Nuclear Information System (INIS)

    Hhalel, A.M.

    1990-01-01

    This book intrduces a good knowledge in specifications of ionizing radiation biological effects and the proper protective measures againest harmful effectes. The book is devided in to five main sections, the first one introduces the hostorical bachground of the contributions of a number of scietists in the basic knolwledge of radiation and its biological effects. The second section deals with the physical and chemical principles of radiation the third one talks about radiation detection. While the fourth section talks (via seven chapter) about the effectes of ionizing radiation on living organisms molecules cells, tissues organs systems and the living organism the fifth section talks about the uses of radiation sources, the probability of radiation accidents, protective measures, international recommendations related to doses and safe use of ionizing radiation. (Abed Al-wali Al-ajlouni). 53 refs., 107 figs., 13 tabs

  19. Synthetic Biology for Specialty Chemicals.

    Science.gov (United States)

    Markham, Kelly A; Alper, Hal S

    2015-01-01

    In this review, we address recent advances in the field of synthetic biology and describe how those tools have been applied to produce a wide variety of chemicals in microorganisms. Here we classify the expansion of the synthetic biology toolbox into three different categories based on their primary function in strain engineering-for design, for construction, and for optimization. Next, focusing on recent years, we look at how chemicals have been produced using these new synthetic biology tools. Advances in producing fuels are briefly described, followed by a more thorough treatment of commodity chemicals, specialty chemicals, pharmaceuticals, and nutraceuticals. Throughout this review, an emphasis is placed on how synthetic biology tools are applied to strain engineering. Finally, we discuss organism and host strain diversity and provide a future outlook in the field.

  20. Mutagenic effect of ionizing radiation and chemical and environmental agents in Tradescantia

    International Nuclear Information System (INIS)

    Cebulska-Wasilewska, A.

    1988-01-01

    The studies covered the following problems: an influence of some environmental agents on the mutagenic effectiveness of ionizing radiation, interaction between ionizing radiation and chemical mutagens in the induction of somatic mutations and also an application of Tradescantia model system for biological monitoring. The studies showed that the pretreatment of Tradescantia plants with sodium fluoride or the modification of the soil composition with dolomite admixture, visibly influences plants radiosensitivity. The analysis of the changes in the dose-response curves suggested that the employed agents were influencing in different ways the repair processes of the DNA. The studies on the interaction between agents proved that the synergistic effect occurs in case of combined action of ionizing radiation with such chemical mutagens as ethyl methansulfonate or 1,2 dibromomethane. It was also discovered that in the range of low doses the effect was proportional to radiation dose and total exposition to chemical mutagen. The field application of Tradescantia method defined the mutagenicity of air pollution in the Cracow area. The highest frequencies of mutations were detected after the Chernobyl accident and after the damage of the filters in the Pharmaceutical Plant. The applied method was evaluated in respect of its usefulness for biological monitoring of environmental pollution. 163 refs. (author)

  1. Areas of research in radiation chemistry fundamental to radiation biology

    International Nuclear Information System (INIS)

    Powers, E.L.

    1980-01-01

    Among all the environmental hazards to which man is exposed, ionizing radiation is the most thoroughly investigated and the most responsibly monitored and controlled. Nevertheless, because of the importance of radiation in modern society from both the hazard as well as the utilitarian standpoints, much more information concerning the biological effects induced and their modification and reversal is required. Together with radiation physics, an understanding of radiation chemistry is necessary for full appreciation of biological effects of high and low energy radiations, and for the development of prophylactic, therapeutic and potentiating methods and techniques in biological organisms. The necessity of understanding the chemistry of any system, biological or not, that is to be manipulated and controlled, is so obvious as to make trivial a statement to that effect. If any natural phenomenon is to be put to our use, surely the elements of it must be studied and appreciated fully. In the preliminary statements of the various panels of this general group, the need for additional information on the basic radiation chemistry concerned in radiation-induced biological effects pervades throughout

  2. Radiation efficiency during slow crack propagation: an experimental study.

    Science.gov (United States)

    Jestin, Camille; Lengliné, Olivier; Schmittbuhl, Jean

    2017-04-01

    Creeping faults are known to host a significant aseismic deformation. However, the observations of micro-earthquake activity related to creeping faults (e.g. San Andreas Faults, North Anatolian Fault) suggest the presence of strong lateral variabilities of the energy partitioning between radiated and fracture energies. The seismic over aseismic slip ratio is rather difficult to image over time and at depth because of observational limitations (spatial resolution, sufficiently broad band instruments, etc.). In this study, we aim to capture in great details the energy partitioning during the slow propagation of mode I fracture along a heterogeneous interface, where the toughness is strongly varying in space.We lead experiments at laboratory scale on a rock analog model (PMMA) enabling a precise monitoring of fracture pinning and depinning on local asperities in the brittle-creep regime. Indeed, optical imaging through the transparent material allows the high resolution description of the fracture front position and velocity during its propagation. At the same time, acoustic emissions are also measured by accelerometers positioned around the rupture. Combining acoustic records, measurements of the crack front position and the loading curve, we compute the total radiated energy and the fracture energy. We deduce from them the radiation efficiency, ηR, characterizing the proportion of the available energy that is radiated in form of seismic wave. We show an increase of ηR with the crack rupture speed computed for each of our experiments in the sub-critical crack propagation domain. Our experimental estimates of ηR are larger than the theoretical model proposed by Freund, stating that the radiation efficiency of crack propagation in homogeneous media is proportional to the crack velocity. Our results are demonstrated to be in agreement with existing studies which showed that the distribution of crack front velocity in a heterogeneous medium can be well described by a

  3. TH-A-BRD-01: Radiation Biology for Radiation Therapy Physicists

    International Nuclear Information System (INIS)

    Orton, C; Borras, C; Carlson, D

    2014-01-01

    Mechanisms by which radiation kills cells and ways cell damage can be repaired will be reviewed. The radiobiological parameters of dose, fractionation, delivery time, dose rate, and LET will be discussed. The linear-quadratic model for cell survival for high and low dose rate treatments and the effect of repopulation will be presented and discussed. The rationale for various radiotherapy techniques such as conventional fractionation, hyperfractionation, hypofractionation, and low and high dose rate brachytherapy, including permanent implants, will be presented. The radiobiological principles underlying radiation protection guidelines and the different radiation dosimetry terms used in radiation biology and in radiation protection will be reviewed. Human data on radiation induced cancer, including increases in the risk of second cancers following radiation therapy, as well as data on radiation induced tissue reactions, such as cardiovascular effects, for follow up times up to 20–40 years, published by ICRP, NCRP and BEIR Committees, will be examined. The latest risk estimates per unit dose will be presented. Their adoption in recent radiation protection standards and guidelines and their impact on patient and workers safety in radiotherapy will be discussed. Biologically-guided radiotherapy (BGRT) provides a systematic method to derive prescription doses that integrate patient-specific information about tumor and normal tissue biology. Treatment individualization based on patient-specific biology requires the identification of biological objective functions to facilitate the design and comparison of competing treatment modalities. Biological objectives provide a more direct approach to plan optimization instead of relying solely on dose-based surrogates and can incorporate factors that alter radiation response, such as DNA repair, tumor hypoxia, and relative biological effectiveness. We review concepts motivating biological objectives and provide examples of how

  4. TH-A-BRD-01: Radiation Biology for Radiation Therapy Physicists

    Energy Technology Data Exchange (ETDEWEB)

    Orton, C [Wayne State University, Grosse Pointe, MI (United States); Borras, C [Radiological Physics and Health Services, Washington, DC (United States); Carlson, D [Yale University School of Medicine, New Haven, CT (United States)

    2014-06-15

    Mechanisms by which radiation kills cells and ways cell damage can be repaired will be reviewed. The radiobiological parameters of dose, fractionation, delivery time, dose rate, and LET will be discussed. The linear-quadratic model for cell survival for high and low dose rate treatments and the effect of repopulation will be presented and discussed. The rationale for various radiotherapy techniques such as conventional fractionation, hyperfractionation, hypofractionation, and low and high dose rate brachytherapy, including permanent implants, will be presented. The radiobiological principles underlying radiation protection guidelines and the different radiation dosimetry terms used in radiation biology and in radiation protection will be reviewed. Human data on radiation induced cancer, including increases in the risk of second cancers following radiation therapy, as well as data on radiation induced tissue reactions, such as cardiovascular effects, for follow up times up to 20–40 years, published by ICRP, NCRP and BEIR Committees, will be examined. The latest risk estimates per unit dose will be presented. Their adoption in recent radiation protection standards and guidelines and their impact on patient and workers safety in radiotherapy will be discussed. Biologically-guided radiotherapy (BGRT) provides a systematic method to derive prescription doses that integrate patient-specific information about tumor and normal tissue biology. Treatment individualization based on patient-specific biology requires the identification of biological objective functions to facilitate the design and comparison of competing treatment modalities. Biological objectives provide a more direct approach to plan optimization instead of relying solely on dose-based surrogates and can incorporate factors that alter radiation response, such as DNA repair, tumor hypoxia, and relative biological effectiveness. We review concepts motivating biological objectives and provide examples of how

  5. Propagation speed of gamma radiation in brass

    International Nuclear Information System (INIS)

    Cavalcante, Jose T.P.D.; Silva, Paulo R.J.; Saitovich, Henrique

    2009-01-01

    The propagation speed (PS) of visible light -represented by a short frequency range in the large frame of electromagnetic radiations (ER) frequencies- in air was measured during the last century, using a great deal of different methods, with high precision results being achieved. Presently, a well accepted value, with very small uncertainty, is c= 299,792.458 Km/s) (c reporting to the Latin word celeritas: 'speed swiftness'). When propagating in denser material media (MM), such value is always lower when compared to the air value, with the propagating MM density playing an important role. Until present, such studies focusing propagation speeds, refractive indexes, dispersions were specially related to visible light, or to ER in wavelengths ranges dose to it, and with a transparent MM. A first incursion in this subject dealing with γ-rays was performed using an electronic coincidence counting system, when the value of it's PS was measured in air, C γ(air) 298,300.15 Km/s; a method that went on with later electronic improvements. always in air. To perform such measurements the availability of a γ-radiation source in which two γ-rays are emitted simultaneously in opposite directions -as already used as well as applied in the present case- turns out to be essential to the feasibility of the experiment, as far as no reflection techniques could be used. Such a suitable source was the positron emitter 22 Na placed in a thin wall metal container in which the positrons are stopped and annihilated when reacting with the medium electrons, in such way originating -as it is very well established from momentum/energy conservation laws - two gamma-rays, energy 511 KeV each, both emitted simultaneously in opposite directions. In all the previous experiments were used photomultiplier detectors coupled to NaI(Tl) crystal scintillators, which have a good energy resolution but a deficient time resolution for such purposes. Presently, as an innovative improvement, were used BaF 2

  6. Effects of radiation and chemical substances on cells and organism

    International Nuclear Information System (INIS)

    Fremuth, F.

    1981-01-01

    The book treats the radiation chemistry part of biophysics and applied biophysics in the sphere of ionizing radiation. Discussed are the concepts of radiation units and radioactivity units and the relative biological efficiency. The effects of ionizing and UV radiations are analyzed at the level of macromolecular changes. Chapters dealing with genetic radiation effects discuss the effects at the cellular level with respect to cell proliferation. All these problems are used to illustrate the effect on the organism as a whole. The chapters on applied biophysics deal with the indications of radiation and chemical damage, sensitivity of cells and the organism, and the study and influencing of growth at the cellular level. The concluding chapter is devoted to the environmental impact of radiation. (J.P.)

  7. Radiation biology: a century of hopes and disappointments

    International Nuclear Information System (INIS)

    Singh, B.B.

    1998-01-01

    In the history of science, radiation biology will rank perhaps as the most popular subject to have attracted researchers from many disciplines of basic as well as applied sciences. Apart from the excitement arising in clinics relating to radiation treatment of cancers the tragedies in Hiroshima and Nagasaki brought numerous scientists together to investigate the harmful biological effects of ionizing radiation. It is then radiation biology picked up a great momentum. It started developing in two different directions what may be called basic radiation biology and radiation biology applied to radiotherapy of cancer. While great strides were being made in basic radiation biology trying to understand the biological effects of radiation and mechanisms thereof, clinical aspect remained confined mainly to the medical fraternity where empiricalism became the rule

  8. Chemical, biological, radiological, and nuclear decontamination: Recent trends and future perspective

    Directory of Open Access Journals (Sweden)

    Vinod Kumar

    2010-01-01

    Full Text Available Chemical, biological, radiological, and nuclear (CBRN decontamination is the removal of CBRN material from equipment or humans. The objective of the decontamination is to reduce radiation burden, salvage equipment, and materials, remove loose CBRN contaminants, and fix the remaining in place in preparation for protective storage or permanent disposal work activities. Decontamination may be carried out using chemical, electrochemical, and mechanical means. Like materials, humans may also be contaminated with CBRN contamination. Changes in cellular function can occur at lower radiation doses and exposure to chemicals. At high dose, cell death may take place. Therefore, decontamination of humans at the time of emergency while generating bare minimum waste is an enormous task requiring dedication of large number of personnel and large amount of time. General principles of CBRN decontamination are discussed in this review with emphasis on radiodecontamination.

  9. ChemProt: a disease chemical biology database

    DEFF Research Database (Denmark)

    Taboureau, Olivier; Nielsen, Sonny Kim; Audouze, Karine Marie Laure

    2011-01-01

    Systems pharmacology is an emergent area that studies drug action across multiple scales of complexity, from molecular and cellular to tissue and organism levels. There is a critical need to develop network-based approaches to integrate the growing body of chemical biology knowledge with network...... biology. Here, we report ChemProt, a disease chemical biology database, which is based on a compilation of multiple chemical-protein annotation resources, as well as disease-associated protein-protein interactions (PPIs). We assembled more than 700 000 unique chemicals with biological annotation for 30...... evaluation of environmental chemicals, natural products and approved drugs, as well as the selection of new compounds based on their activity profile against most known biological targets, including those related to adverse drug events. Results from the disease chemical biology database associate citalopram...

  10. Innovations in Undergraduate Chemical Biology Education.

    Science.gov (United States)

    Van Dyke, Aaron R; Gatazka, Daniel H; Hanania, Mariah M

    2018-01-19

    Chemical biology derives intellectual vitality from its scientific interface: applying chemical strategies and perspectives to biological questions. There is a growing need for chemical biologists to synergistically integrate their research programs with their educational activities to become holistic teacher-scholars. This review examines how course-based undergraduate research experiences (CUREs) are an innovative method to achieve this integration. Because CUREs are course-based, the review first offers strategies for creating a student-centered learning environment, which can improve students' outcomes. Exemplars of CUREs in chemical biology are then presented and organized to illustrate the five defining characteristics of CUREs: significance, scientific practices, discovery, collaboration, and iteration. Finally, strategies to overcome common barriers in CUREs are considered as well as future innovations in chemical biology education.

  11. Nuclear, biological and chemical warfare. Part I: Medical aspects of nuclear warfare.

    Science.gov (United States)

    Kasthuri, A S; Pradhan, A B; Dham, S K; Bhalla, I P; Paul, J S

    1990-04-01

    Casualties in earlier wars were due much more to diseases than to weapons. Mention has been made in history of the use of biological agents in warfare, to deny the enemy food and water and to cause disease. In the first world war chemical agents were used to cause mass casualties. Nuclear weapons were introduced in the second world war. Several countries are now involved in developing nuclear, biological and chemical weapon systems, for the mass annihilation of human beings, animals and plants, and to destroy the economy of their enemies. Recently, natural calamities and accidents in nuclear, chemical and biological laboratories and industries have caused mass instantaneous deaths in civilian population. The effects of future wars will not be restricted to uniformed persons. It is time that physicians become aware of the destructive potential of these weapons. Awareness, immediate protective measures and first aid will save a large number of persons. This series of articles will outline the medical aspects of nuclear, biological and chemical weapon systems in three parts. Part I will deal with the biological effects of a nuclear explosion. The short and long term effects due to blast, heat and associated radiation are highlighted. In Part II, the role of biological agents which cause commoner or new disease patterns is mentioned. Some of the accidents from biological warfare laboratories are a testimony to its potential deleterious effects. Part III deals with medical aspects of chemical warfare agents, which in view of their mass effects can overwhelm the existing medical resources, both civilian and military.(ABSTRACT TRUNCATED AT 250 WORDS)

  12. Wave propagation in a quasi-chemical equilibrium plasma

    Science.gov (United States)

    Fang, T.-M.; Baum, H. R.

    1975-01-01

    Wave propagation in a quasi-chemical equilibrium plasma is studied. The plasma is infinite and without external fields. The chemical reactions are assumed to result from the ionization and recombination processes. When the gas is near equilibrium, the dominant role describing the evolution of a reacting plasma is played by the global conservation equations. These equations are first derived and then used to study the small amplitude wave motion for a near-equilibrium situation. Nontrivial damping effects have been obtained by including the conduction current terms.

  13. Biology relevant to space radiation

    International Nuclear Information System (INIS)

    Fry, R.J.M.

    1996-01-01

    The biological effects of the radiations to which mankind on earth are exposed are becoming known with an increasing degree of detail. This knowledge is the basis of the estimates of risk that, in turn, fosters a comprehensive and evolving radiation protection system. The substantial body of information has been, and is being, applied to questions about the biological effects of radiation is space and the associated risk estimates. The purpose of this paper is not to recount all the biological effect of radiation but to concentrate on those that may occur as a result from exposure to the radiations encountered in space. In general, the biological effects of radiation in space are the same as those on earth. However, the evidence that the effects on certain tissues by the heaviest-charged particles can be interpreted on the basis of our knowledge about other high-LET radiation is equivocal. This specific question will be discussed in greater detail later. It is important to point out the that there are only limited data about the effects on humans of two components of the radiations in space, namely protons and heavy ions. Thus predictions of effects on space crews are based on experimental systems exposed on earth at rates and fluences that are higher than those in space and one the effects of gamma or x rays with estimates of the equivalent doses using quality factors

  14. Mechanism of Interaction between Ionizing Radiation and Chemicals

    International Nuclear Information System (INIS)

    Kim, Jin Kyu; Lee, B. H.; Shin, H. S.

    2008-03-01

    This research project has been carried out jointly with INP (Poland) to develop technologies for 'Mechanism of Interaction between ionizing radiation and chemicals . Several biological end-points were assessed in experimental organisms such as higher plants, rats, cell lines and yeast cells to establish proper bioassay techniques. The Tradescantia somatic cell mutation assay was carried out, and immunohistochemistry and hormone assays were done in Fisher 344 rats and cell lines to analyse the combined effect of ionizing radiation with mercury chloride. Using the common regularities of combined actions of two factors, a theoretical model was established, and applied to the thermo radiation action and synergism between two chemicals, as well. The model approach made it possible to predict the condition under which the maximum synergism could be attained. The research results were published in high standard journals and presented in the scientific conferences to verify KAERI's current technology level. The experience of collaboration can be used as a fundamental tool for multinational collaboration, and make the role of improving relationship between Korea and Poland

  15. Mechanism of Interaction between Ionizing Radiation and Chemicals

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jin Kyu; Lee, B H; Shin, H S [and others

    2008-03-15

    This research project has been carried out jointly with INP (Poland) to develop technologies for 'Mechanism of Interaction between ionizing radiation and chemicals{sup .} Several biological end-points were assessed in experimental organisms such as higher plants, rats, cell lines and yeast cells to establish proper bioassay techniques. The Tradescantia somatic cell mutation assay was carried out, and immunohistochemistry and hormone assays were done in Fisher 344 rats and cell lines to analyse the combined effect of ionizing radiation with mercury chloride. Using the common regularities of combined actions of two factors, a theoretical model was established, and applied to the thermo radiation action and synergism between two chemicals, as well. The model approach made it possible to predict the condition under which the maximum synergism could be attained. The research results were published in high standard journals and presented in the scientific conferences to verify KAERI's current technology level. The experience of collaboration can be used as a fundamental tool for multinational collaboration, and make the role of improving relationship between Korea and Poland.

  16. Mechanism of Interaction between Ionizing Radiation and Chemicals

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jin Kyu; Lee, B. H.; Shin, H. S. (and others)

    2008-03-15

    This research project has been carried out jointly with INP (Poland) to develop technologies for 'Mechanism of Interaction between ionizing radiation and chemicals{sup .} Several biological end-points were assessed in experimental organisms such as higher plants, rats, cell lines and yeast cells to establish proper bioassay techniques. The Tradescantia somatic cell mutation assay was carried out, and immunohistochemistry and hormone assays were done in Fisher 344 rats and cell lines to analyse the combined effect of ionizing radiation with mercury chloride. Using the common regularities of combined actions of two factors, a theoretical model was established, and applied to the thermo radiation action and synergism between two chemicals, as well. The model approach made it possible to predict the condition under which the maximum synergism could be attained. The research results were published in high standard journals and presented in the scientific conferences to verify KAERI's current technology level. The experience of collaboration can be used as a fundamental tool for multinational collaboration, and make the role of improving relationship between Korea and Poland.

  17. Biological Complexities in Radiation Carcinogenesis and Cancer Radiotherapy: Impact of New Biological Paradigms

    Directory of Open Access Journals (Sweden)

    Hossein Mozdarani

    2012-01-01

    Full Text Available Although radiation carcinogenesis has been shown both experimentally and epidemiologically, the use of ionizing radiation is also one of the major modalities in cancer treatment. Various known cellular and molecular events are involved in carcinogenesis. Apart from the known phenomena, there could be implications for carcinogenesis and cancer prevention due to other biological processes such as the bystander effect, the abscopal effect, intrinsic radiosensitivity and radioadaptation. Bystander effects have consequences for mutation initiated cancer paradigms of radiation carcinogenesis, which provide the mechanistic justification for low-dose risk estimates. The abscopal effect is potentially important for tumor control and is mediated through cytokines and/or the immune system (mainly cell-mediated immunity. It results from loss of growth and stimulatory and/or immunosuppressive factors from the tumor. Intrinsic radiosensitivity is a feature of some cancer prone chromosomal breakage syndromes such as ataxia telangectiasia. Radiosensitivity is manifested as higher chromosomal aberrations and DNA repair impairment is now known as a good biomarker for breast cancer screening and prediction of prognosis. However, it is not yet known whether this effect is good or bad for those receiving radiation or radiomimetic agents for treatment. Radiation hormesis is another major concern for carcinogenesis. This process which protects cells from higher doses of radiation or radio mimic chemicals, may lead to the escape of cells from mitotic death or apoptosis and put cells with a lower amount of damage into the process of cancer induction. Therefore, any of these biological phenomena could have impact on another process giving rise to genome instability of cells which are not in the field of radiation but still receiving a lower amount of radiation. For prevention of radiation induced carcinogenesis or risk assessment as well as for successful radiation

  18. Use of synchrotron radiation in radiation biology research

    International Nuclear Information System (INIS)

    Yamada, Takeshi

    1981-01-01

    Synchrotron radiation (SR) holds great expectation as a new research tool in the new areas of material science, because it has the continuous spectral distribution from visible light to X-ray, and its intensity is 10 2 to 10 3 times as strong as that of conventional radiation sources. In the National Laboratory for High Energy Physics, a synchrotron radiation experimental facility has been constructed, which will start operation in fiscal 1982. With this SR, the photons having the wavelength in undeveloped region from vacuum ultraviolet to soft X-ray are obtained as intense mono-wavelength light. The SR thus should contribute to the elucidation of the fundamentals in the biological action of radiation. The following matters are described: synchrotron radiation, experimental facility using SR, electron storage ring, features of SR, photon factory plan and synchrotron radiation experimental facility, utilization of SR in radiation biology field. (J.P.N.)

  19. Introducing Biological Microdosimetry for Ionising Radiation

    International Nuclear Information System (INIS)

    Scott, B.R.; Schoellnberger, H.

    2000-01-01

    Microdosimetry is important for radiation protection, for understanding mechanisms of radiation action, and for radiation risk assessment. This article introduces a generic, Monte Carlo based approach to biological microdosimetry for ionising radiation. Our Monte Carlo analyses are carried out with a widely used Crystal Ball software. The approach to biological microdosimetry presented relates to quantal biological effects data (e.g. cell survival, mutagenesis, neoplastic transformation) for which there is an initial linear segment to the dose-response curve. The macroscopic dose data considered were selected such that is could be presumed that the vast majority of cells at risk have radiation dose delivered to their critical target. For cell killing, neoplastic transformation, and mutagenesis, the critical biological target for radiation is presumed to be DNA. Our approach to biological microdosimetry does not require detailed information about the mass, volume, and shape of the critical biological target. Further, one does not have to know what formal distribution function applies to the microdose distribution. However, formal distributions are required for the biological data used to derive the non-parametric microdose distributions. Here, we use the binomial distribution to characterise the variability in the number of cells affected by a fixed macroscopic dose. Assuming this variability to arise from variability in the microscopic dose to the critical biological target, a non-parametric microdose distribution is generated by the standard Monte Carlo method. The non-parametric distribution is then fitted using a set of formal distributions (beta, exponential, extreme value, gamma, logistic, log-normal, normal, Pareto, triangular, uniform, and Weibull). The best fit is then evaluated based on statistical criteria (chi-square test). To demonstrate the application of biological microdosimetry, the standard Monte Carlo method is used with radiobiological data for

  20. Introducing Biological Microdosimetry for Ionising Radiation

    Energy Technology Data Exchange (ETDEWEB)

    Scott, B.R.; Schoellnberger, H

    2000-07-01

    Microdosimetry is important for radiation protection, for understanding mechanisms of radiation action, and for radiation risk assessment. This article introduces a generic, Monte Carlo based approach to biological microdosimetry for ionising radiation. Our Monte Carlo analyses are carried out with a widely used Crystal Ball software. The approach to biological microdosimetry presented relates to quantal biological effects data (e.g. cell survival, mutagenesis, neoplastic transformation) for which there is an initial linear segment to the dose-response curve. The macroscopic dose data considered were selected such that is could be presumed that the vast majority of cells at risk have radiation dose delivered to their critical target. For cell killing, neoplastic transformation, and mutagenesis, the critical biological target for radiation is presumed to be DNA. Our approach to biological microdosimetry does not require detailed information about the mass, volume, and shape of the critical biological target. Further, one does not have to know what formal distribution function applies to the microdose distribution. However, formal distributions are required for the biological data used to derive the non-parametric microdose distributions. Here, we use the binomial distribution to characterise the variability in the number of cells affected by a fixed macroscopic dose. Assuming this variability to arise from variability in the microscopic dose to the critical biological target, a non-parametric microdose distribution is generated by the standard Monte Carlo method. The non-parametric distribution is then fitted using a set of formal distributions (beta, exponential, extreme value, gamma, logistic, log-normal, normal, Pareto, triangular, uniform, and Weibull). The best fit is then evaluated based on statistical criteria (chi-square test). To demonstrate the application of biological microdosimetry, the standard Monte Carlo method is used with radiobiological data for

  1. Biological research for radiation protection

    Energy Technology Data Exchange (ETDEWEB)

    Kim, In Gyu; Kim, Kug Chan; Shim, Hae Won; Oh, Tae Jeong; Park, Seon Young; Lee, Kang Suk

    2000-04-01

    The work scope of Biological research for the radiation protection had contained the search of biological microanalytic methods for assessing the health effect by {gamma}-radiation and toxic agents, the standardization of human T-lymphocyte cell culture and polymerase chain reaction, T-cell clonal assay, and the quantification of mutation frequency in the hypoxanthine (guanine) phosphoribosyl transferase (HPRT) gene locus by single exposure or combined exposure. Especially, the polymerase chain reaction methods using reverse transcriptase has been developed to analyze the mutant gene induced by {gamma}-radiation and chemical (pentachlorophenol) agent exposure, and to investigate the point mutations in the HPRT gene locus of T-lymphocytes. The HPRT T-cell clonal assay revealed that it could not differentiate {gamma}-irradiation from pentachlorophenol, because the frequency of somatic mutations induced by both damaging agents increased in a dose-dependent manner. The analysis of DNA sequence alterations of HPRT mutant clones clearly showed that both damaging agents induced different mutational spectra in the HPRT locus of T-cells. The large deletions, which account for 75 percent of the analyzed mutants, are characteristic mutations induced by {gamma}-irradiation. By contrast, point mutations such as base substitutions and insertion, come up to 97 percent in the case of pentachlorophenol-treated cells. The point mutation frequencies at 190 base pair and 444 base pair positions are 3-6 folds as high as in those at other mutation positions. It may be that these mutation sites are hot spots induced by pentachlorophenol. These results suggest that the HPRT mutation spectrum can be used as a potential bio marker for assessing a specific environmental risk. (author)

  2. Biological research for radiation protection

    International Nuclear Information System (INIS)

    Kim, In Gyu; Kim, Kug Chan; Shim, Hae Won; Oh, Tae Jeong; Park, Seon Young; Lee, Kang Suk

    2000-04-01

    The work scope of Biological research for the radiation protection had contained the search of biological microanalytic methods for assessing the health effect by γ-radiation and toxic agents, the standardization of human T-lymphocyte cell culture and polymerase chain reaction, T-cell clonal assay, and the quantification of mutation frequency in the hypoxanthine (guanine) phosphoribosyl transferase (HPRT) gene locus by single exposure or combined exposure. Especially, the polymerase chain reaction methods using reverse transcriptase has been developed to analyze the mutant gene induced by γ-radiation and chemical (pentachlorophenol) agent exposure, and to investigate the point mutations in the HPRT gene locus of T-lymphocytes. The HPRT T-cell clonal assay revealed that it could not differentiate γ-irradiation from pentachlorophenol, because the frequency of somatic mutations induced by both damaging agents increased in a dose-dependent manner. The analysis of DNA sequence alterations of HPRT mutant clones clearly showed that both damaging agents induced different mutational spectra in the HPRT locus of T-cells. The large deletions, which account for 75 percent of the analyzed mutants, are characteristic mutations induced by γ-irradiation. By contrast, point mutations such as base substitutions and insertion, come up to 97 percent in the case of pentachlorophenol-treated cells. The point mutation frequencies at 190 base pair and 444 base pair positions are 3-6 folds as high as in those at other mutation positions. It may be that these mutation sites are hot spots induced by pentachlorophenol. These results suggest that the HPRT mutation spectrum can be used as a potential bio marker for assessing a specific environmental risk. (author)

  3. Radiation research contracts: Biological effects of small radiation doses

    Energy Technology Data Exchange (ETDEWEB)

    Hug, O [International Atomic Energy Agency, Division of Health, Safety and Waste Disposal, Vienna (Austria)

    1959-04-15

    To establish the maximum permissible radiation doses for occupational and other kinds of radiation exposure, it is necessary to know those biological effects which can be produced by very small radiation doses. This particular field of radiation biology has not yet been sufficiently explored. This holds true for possible delayed damage after occupational radiation exposure over a period of many years as well as for acute reactions of the organism to single low level exposures. We know that irradiation of less than 25 Roentgen units (r) is unlikely to produce symptoms of radiation sickness. We have, however, found indications that even smaller doses may produce certain instantaneous reactions which must not be neglected

  4. Subwavelength propagation and localization of light using surface ...

    Indian Academy of Sciences (India)

    2014-01-09

    Jan 9, 2014 ... methods to excite, propagate and detect SPPs and LSPs. 2. ... plasmonic imaging [12], back-focal plane imaging, plasmon leakage radiation ..... Chemically prepared silver nanowires were first diluted using milli-Q water.

  5. Biological effects of low-dose ionizing radiation exposure

    International Nuclear Information System (INIS)

    Reinoehl-Kompa, Sabine; Baldauf, Daniela; Heller, Horst

    2009-01-01

    The report on the meeting of the Strahlenschutzkommission 2007 concerning biological effects of low-dose ionizing radiation exposure includes the following contributions: Adaptive response. The importance of DNA damage mechanisms for the biological efficiency of low-energy photons. Radiation effects in mammography: the relative biological radiation effects of low-energy photons. Radiation-induced cataracts. Carcinomas following prenatal radiation exposure. Intercellular apoptosis induction and low-dose irradiation: possible consequences for the oncogenesis control. Mechanistic models for the carcinogenesis with radiation-induced cell inactivation: application to all solid tumors in the Japanese atomic bomb survivors. Microarrays at low radiation doses. Mouse models for the analysis of biological effects of low-dose ionizing radiation. The bystander effect: observations, mechanisms and implications. Lung carcinoma risk of Majak workers - modeling of carcinogenesis and the bystander effect. Microbeam studies in radiation biology - an overview. Carcinogenesis models with radiation-induced genomic instability. Application to two epidemiological cohorts.

  6. Long-term biological effects induced by ionizing radiation--implications for dose mediated risk.

    Science.gov (United States)

    Miron, S D; Astărăstoae, V

    2014-01-01

    Ionizing radiations are considered to be risk agents that are responsible for the effects on interaction with living matter. The occurring biological effects are due to various factors such as: dose, type of radiation, exposure time, type of biological tissue, health condition and the age of the person exposed. The mechanisms involved in the direct modifications of nuclear DNA and mitochondrial DNA are reviewed. Classical target theory of energy deposition in the nucleus that causes DNA damages, in particular DNA double-strand breaks and that explanation of the biological consequences of ionizing radiation exposure is a paradigm in radiobiology. Recent experimental evidences have demonstrated the existence of a molecular mechanism that explains the non-targeted effects of ionizing radiation exposure. Among these novel data, genomic instability and a variety of bystander effects are discussed here. Those bystander effects of ionizing radiation are fulfilled by cellular communication systems that give rise to non-targeted effects in the neighboring non irradiated cells. This paper provides also a commentary on the synergistic effects induced by the co-exposures to ionizing radiation and various physical agents such as electromagnetic fields and the co-exposures to ionizing radiation and chemical environmental contaminants such as metals. The biological effects of multiple stressors on genomic instability and bystander effects are also discussed. Moreover, a brief presentation of the methods used to characterize cyto- and genotoxic damages is offered.

  7. A Hypothesis on Biological Protection from Space Radiation Through the Use of New Therapeutic Gases as Medical Counter Measures

    Science.gov (United States)

    Schoenfeld, Michael P.; Ansari, Rafat R.; Nakao, Atsunori; Wink, David

    2012-01-01

    Radiation exposure to astronauts could be a significant obstacle for long duration manned space exploration because of current uncertainties regarding the extent of biological effects. Furthermore, concepts for protective shielding also pose a technically challenging issue due to the nature of cosmic radiation and current mass and power constraints with modern exploration technology. The concern regarding exposure to cosmic radiation is the biological damage it induces. As damage is associated with increased oxidative stress, it is important and would be enabling to mitigate and/or prevent oxidative stress prior to the development of clinical symptoms and disease. This paper hypothesizes a "systems biology" approach in which a combination of chemical and biological mitigation techniques are used conjunctively. It proposes using new, therapeutic, medical gases as both chemical radioprotectors for radical scavenging and biological signaling molecules for management of the body s response to exposure. From reviewing radiochemistry of water, biological effects of CO, H2, NO, and H2S gas, and mechanisms of radiation biology, it is concluded that this approach may have great therapeutic potential for radiation exposure. Furthermore, it also appears to have similar potential for curtailing the pathogenesis of other diseases in which oxidative stress has been implicated including cardiovascular disease, cancer, chronic inflammatory disease, hypertension, ischemia/reperfusion injury, acute respiratory distress syndrome, Parkinson s and Alzheimer s disease, cataracts, and aging.

  8. Effect of ionizing radiation on chemical and biological properties of Salmonella minnesota R595 lipopolysaccharide

    Energy Technology Data Exchange (ETDEWEB)

    El Sabbagh, M; Galanos, C; Luederitz, O [Max-Planck-Institut fuer Immunbiologie, Freiburg (Germany, F.R.); Bertok, L [Orszagos Frederic Joliot-Curie Sugarbiologiai es Sugaregeszseguegyi Kutato Intezet, Budapest (Hungary); Fuest, Gy [Orszagos Haema--tologiai es Vertranszfuzios Intezet, Budapest (Hungary)

    1982-01-01

    The effects of /sup 60/Co irradiation performed with various doses on the biological and chemical properties of the endotoxin of the Salmonella minnesota R595 were compared with those of unirradiated ones. The biological activity was measured using the lethal toxicity test, the local Schwartzman reaction and by activating the complementary system. Increasing the irradiation dose from 50 to 200 kGy the preparation became less active in the biological tests but the protective activity against the lethal action of the endotoxin remained uneffected. The irradiation resulted in a dose-dependent decrease of the amounts of 2-keto-3-deoxy-octonate, glucosamine, fatty acids, but did not affect all the degradation products identified. Therefore, no correlation between the chemical composition and the absence of endotoxin activity was found.

  9. Radiation physics, biophysics, and radiation biology

    International Nuclear Information System (INIS)

    Hall, E.J.

    1992-05-01

    The following research programs from the Center for Radiological Research of Columbia University are described: Design and development of a new wall-less ultra miniature proportional counter for nanodosimetry; some recent measurements of ionization distributions for heavy ions at nanometer site sizes with a wall-less proportional counter; a calculation of exciton energies in periodic systems with helical symmetry: application to a hydrogen fluoride chain; electron energy-loss function in polynucleotide and the question of plasmon excitation; a non-parametric, microdosimetric-based approach to the evaluation of the biological effects of low doses of ionizing radiation; high-LET radiation risk assessment at medium doses; high-LET radiobiological effects: increased lesion severity or increased lesion proximity; photoneutrons generated by high energy medical linacs; the biological effectiveness of neutrons; implications for radiation protection; molecular characterization of oncogenes induced by neutrons; and the inverse dose-rate effect for oncogenic transformation by charged particles is LET dependent

  10. Reducing Future International Chemical and Biological Dangers.

    Energy Technology Data Exchange (ETDEWEB)

    Haddal, Chad [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Bull, Diana L. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Hernandez, Patricia Marie [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Foley, John T. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2017-12-01

    The International Biological and Chemical Threat Reduction Program at Sandia National Laboratories is developing a 15 - year technology road map in support the United States Government efforts to reduce international chemical and biological dangers . In 2017, the program leadership chartered an analysis team to explore dangers in the future international chemical and biological landscape through engagements with national security experts within and beyond Sandia to gain a multidisciplinary perspective on the future . This report offers a hi gh level landscape of future chemical and biological dangers based upon analysis of those engagements and provides support for further technology road map development.

  11. Radiation physics, biophysics, and radiation biology

    International Nuclear Information System (INIS)

    Hall, E.J.; Zaider, M.

    1991-05-01

    Research at the Radiological Research Laboratory is a blend of physics, chemistry, and biology, involving research at the basic level with the admixture of a small proportion of pragmatic or applied research in support of radiation protection and/or radiotherapy. Current research topics include: oncogenic transformation assays, mutation studies involving interactions between radiation and environmental contaminants, isolation, characterization and sequencing of a human repair gene, characterization of a dominant transforming gene found in C3H 10T1/2 cells, characterize ab initio the interaction of DNA and radiation, refine estimates of the radiation quality factor Q, a new mechanistic model of oncogenesis showing the role of long-term low dose medium LET radiation, and time dependent modeling of radiation induced chromosome damage and subsequent repair or misrepair

  12. Biological radiation effects

    International Nuclear Information System (INIS)

    Kiefer, J.

    1989-01-01

    The book covers all aspects of biological radiation effects. The physical basis is dealt with in some detail, and the effects at the subcellular and the cellular level are discussed, taking into account modern developments and techniques. The effects on the human organism are reviewed, both from the point of view of applications in medicine as well as with regard to radiation hazards (teratogenic, gonadal and carcinogenic effects)

  13. E. Biological effects of radiation on man

    International Nuclear Information System (INIS)

    1976-01-01

    This report firstly summarises information on the biological hazards of radiation and their relation to radiation dose, and hence estimates the biological risks associated with nuclear power production. Secondly, it describes the basis and present status of radiation protection standards in the nuclear power industry

  14. Radiation chemical synthesis

    International Nuclear Information System (INIS)

    Zagoretz, P.A.; Poluetkov, V.A.; Shostenko, A.G.

    1986-01-01

    The authors consider processes in radiation chemical synthesis which are being developed in various scientific-research organizations. The important advantages of radiation chlorination, viz. the lower temperature compared with the thermal method and the absence of dehydrochlorination products are discussed. The authors examine the liquid-phase chlorination of trifluorochloroethyltrichloromethyl ether to obtain the pentachloro-contining ether, trifluorodichloroethyltrichloromethyl ether. The authors discuss radiation synthesis processes that have be used formulated kinetic equations on which models have been based. It is concluded that the possibilities of preparative (micro- and low-tonnage) radiation synthesis are promising

  15. On the mechanism of the biological effect of ionizing radiation

    International Nuclear Information System (INIS)

    Margulis, M.A.; Margulis, I.M.

    2005-01-01

    The mechanisms of the biological effects of ionizing radiation (IR) and ultrasound (US) were considered. The current views on the nature of toxicity of IR, which is usually assigned to the formation of radicals in living tissues and to the straight-line collision of an ionizing particle with the DNA molecule, were analyzed. It was established that the amount of radicals formed in biological tissues in conditions of ultrasonically induced cavitation can be as large as that for IR; however, the biological effect of US is much softer as compared to IR. It was shown that the contribution of the indirect mechanism to the total biological effect of IR can be estimated by comparing US and IR in their chemical action; the contribution of the indirect mechanism to the biological effect of IR was found to be negligibly small. An alternative mechanism was proposed to explain the biological effect of IR. In accordance with the proposed model, IR with a high linear energy transfer (LET) value breaks through cell walls and biological membranes and causes damage to them, such that the cell can lose its regenerative capacity. Moreover, high-energy heavy ionizing particles perforate cytoplasm to form channels. Ionizing radiation with a low LET value (γ- and X-rays) causes multiple damages to biological membranes. Ionizing particles can also cause damages to membranes of mitochondria thus affecting the mechanism of cellular respiration, which will cause neoplastic diseases. The straight-line collision of an ionizing particle with a DNA molecule was found to be 5-7 orders of magnitude less probable as compared to the collision with a wall or membrane. It was shown that multiple perforations of cell walls and damages to membranes are characteristic only of ionizing particles, which have sufficiently long tracks, and do not occur upon exposure to ultrasonic waves, microwaves, UV radiation, and magnetic fields [ru

  16. Emerging frontiers in radiation biology

    International Nuclear Information System (INIS)

    Singh, B.B.

    1996-01-01

    Radiation biology owes its origin to the spectacular success in the treatment of human diseases by x-rays and radium, just after their respective discoveries in 1895-96. From the very inception it has attracted researchers from all disciplines of science. The target and hit theory developed by physicists, dominated the scene till the advent of radiation chemistry concepts which offered an entirely different perspective to the mechanisms involved in biological effects of radiations and their modification by endogenous and exogenous agents like radioprotectors and radiosensitisers including hyperthermia. The applied aspect of radiation biology mainly relates to radiation therapy of cancer which, in spite of its long existence, is still to achieve scientific perfection. Nevertheless, it did not wait -and fortunately so-, for its radiobiological rationality but continued its development to be the main modality for cancer treatment today. Several approaches are now being attempted to improve its efficacy by selectively damaging the cancerous cells while sparing the normal tissues and also by devising suitable predictive assays for radioresponse of different tumours to enable individualisation of treatment schedules. (author). 99 refs., 1 fig., 2 tabs

  17. A hypothesis on biological protection from space radiation through the use of new therapeutic gases as medical counter measures

    Directory of Open Access Journals (Sweden)

    Schoenfeld Michael P

    2012-04-01

    Full Text Available Abstract Radiation exposure to astronauts could be a significant obstacle for long duration manned space exploration because of current uncertainties regarding the extent of biological effects. Furthermore, concepts for protective shielding also pose a technically challenging issue due to the nature of cosmic radiation and current mass and power constraints with modern exploration technology. The concern regarding exposure to cosmic radiation is biological damage that is associated with increased oxidative stress. It is therefore important and would be enabling to mitigate and/or prevent oxidative stress prior to the development of clinical symptoms and disease. This paper hypothesizes a "systems biology" approach in which a combination of chemical and biological mitigation techniques are used conjunctively. It proposes using new, therapeutic, medical gases as chemical radioprotectors for radical scavenging and as biological signaling molecules for management of the body's response to exposure. From reviewing radiochemistry of water, biological effects of CO, H2, NO, and H2S gas, and mechanisms of radiation biology, it can be concluded that this approach may have therapeutic potential for radiation exposure. Furthermore, it also appears to have similar potential for curtailing the pathogenesis of other diseases in which oxidative stress has been implicated including cardiovascular disease, cancer, chronic inflammatory disease, hypertension, ischemia/reperfusion (IR injury, acute respiratory distress syndrome, Parkinson's and Alzheimer's disease, cataracts, and aging. We envision applying these therapies through inhalation of gas mixtures or ingestion of water with dissolved gases.

  18. The effect of radiation-sterilization conditions and preservation procedures on physico-chemical and biological properties of bone allografts

    International Nuclear Information System (INIS)

    Goclawska, A.D.; Kaminski, A.; Wasilewska, M.

    1999-01-01

    Radiation-sterilization of connective tissue allografts (bone including) with a dose of 35 kGy is routinely used in the Central Tissue Bank in Warsaw since 1963. This method of sterilization offers many advantages: good penetration ability, relatively low temperature rise, and possibility of sterilization of grafts in closed beforehand vials, which protects against secondary contamination. It should be kept in mind, however that high doses of ionizing radiation (in the range of 20-35 kGy) used for sterilization evoke many chemical and physical changes which may influence biological properties of grafts. These changes have been studied using various methodological approaches. Using electron paramagnetic resonance (EPR) spectrometry it has been found that in radiation-sterilized bone two types of paramagnetic entities are generated: i/ coliagen radicals which are unstable and disappear completely in the presence of air oxygen, ii/ very stable at room temperature paramagnetic defects (centers) localized in the crystalline lattice of bone mineral. These stable paramagnetic defects have been treated as a new kind of markers and used for: a/ quantitative evaluation of remodeling process of radiation-sterilized bone allografts preserved by lyophilization or deep freezing; b/ estimation of the dose of ionizing radiation absorbed by living organism in the case of accidental exposure (skeleton serving as a dosimeter) and for control of radiation-sterilization process. The effect of radiation-sterilization and preservation procedures on bone allografts was studied using a model of heterotopically induced osteogenesis and measuring the solubility of bone collagen in vitro. It has been observed that lyophilized bone allografts irradiated at room temp. with doses of 35 and 50 kGy, respectively, were very quickly resorbed in vivo and did not induce osteogenesis, while lyophilized as well as deep-frozen matrices irradiated at -7OoC were slowly resorbed and induced de novo bone fon

  19. Statistical Modeling of Radiative Transfer and Transient Characteristics for Multilayer Biological Tissue

    Directory of Open Access Journals (Sweden)

    S. Yu. Makarov

    2014-01-01

    Full Text Available The Monte-Carlo method [1] already long ago proved itself as a powerful and universal tool for mathematical modelling in various areas of science and engineering. Researchers often choose this method when it is difficult to find a solution by other ways (or impossible at all, e.g. because of sophisticated analytical dependences, area of modelling or boundary conditions. Certainly, this necessarily statistical and flexible method requires significant computation time, but a continuously increasing computation capability makes it more and more attractive for a choice in specific situation.One of the promising areas to use the method of statistical modelling is description of light propagation in the turbid (scattering media. A high motivation for development of this approach is widely used lasers in biomedicine [3]. Besides, owing to its flexibility, the Monte-Carlo method is also of importance in theoretical researches, in particular, to estimate a degree of adequacy of the offered approximation methods for solving a radiative transfer equation [4].It is known that key parameters of turbid media are an absorption coefficient (characterizes absorption probability of a photon per unit of path length and a scattering coefficient (characterizes scattering probability of a photon per unit of path length. The ratio of each of the coefficients to their sum (extinction defines a probability of "death" or "survival" of a photon, respectively, in interaction with lenses. Generally, in the scattering medium there is a non-coherent radiation component, which in turbid media such as biological tissues, already at the insignificant depth becomes prevailing over the coherent one (residual of the incident laser beam [5].The author used the Monte-Carlo method to simulate optical radiation propagation in the multilayer biological tissues with their optical characteristics corresponding to the skin and subcutaneous tissues. Such a biological tissue is the absorbing

  20. History of chemical and biological warfare agents

    International Nuclear Information System (INIS)

    Szinicz, L.

    2005-01-01

    Chemical and biological warfare agents constitute a low-probability, but high-impact risk both to the military and to the civilian population. The use of hazardous materials of chemical or biological origin as weapons and for homicide has been documented since ancient times. The first use of chemicals in terms of weapons of mass destruction goes back to World War I, when on April 22, 1915 large amounts of chlorine were released by German military forces at Ypres, Belgium. Until around the 1970s of the 20th century, the awareness of the threat by chemical and biological agents had been mainly confined to the military sector. In the following time, the development of increasing range delivery systems by chemical and biological agents possessors sensitised public attention to the threat emanating from these agents. Their proliferation to the terrorists field during the 1990s with the expanding scale and globalisation of terrorist attacks suggested that these agents are becoming an increasing threat to the whole world community. The following article gives a condensed overview on the history of use and development of the more prominent chemical and biological warfare agents

  1. History of chemical and biological warfare agents.

    Science.gov (United States)

    Szinicz, L

    2005-10-30

    Chemical and biological warfare agents constitute a low-probability, but high-impact risk both to the military and to the civilian population. The use of hazardous materials of chemical or biological origin as weapons and for homicide has been documented since ancient times. The first use of chemicals in terms of weapons of mass destruction goes back to World War I, when on April 22, 1915 large amounts of chlorine were released by German military forces at Ypres, Belgium. Until around the 1970s of the 20th century, the awareness of the threat by chemical and biological agents had been mainly confined to the military sector. In the following time, the development of increasing range delivery systems by chemical and biological agents possessors sensitised public attention to the threat emanating from these agents. Their proliferation to the terrorists field during the 1990s with the expanding scale and globalisation of terrorist attacks suggested that these agents are becoming an increasing threat to the whole world community. The following article gives a condensed overview on the history of use and development of the more prominent chemical and biological warfare agents.

  2. International Journal of Biological and Chemical Sciences ...

    African Journals Online (AJOL)

    International Journal of Biological and Chemical Sciences: Advanced Search. Journal Home > International Journal of Biological and Chemical Sciences: Advanced Search. Log in or Register to get access to full text downloads.

  3. Biological effects of proton radiation: an update

    International Nuclear Information System (INIS)

    Girdhani, S.; Hlatky, L.; Sachs, R.

    2015-01-01

    Proton radiation provides significant dosimetric advantages when compared with gamma radiation due to its superior energy deposition characteristics. Although the physical aspects of proton radiobiology are well understood, biological and clinical endpoints are understudied. The current practice to assume the relative biological effectiveness of low linear energy transfer (LET) protons to be a generic value of about 1.1 relative to photons likely obscures important unrecognised differentials in biological response between these radiation qualities. A deeper understanding of the biological properties induced by proton radiation would have both radiobiological and clinical impact. This article briefly points to some of the literature pertinent to the effects of protons on tissue-level processes that modify disease progression, such as angiogenesis, cell invasion and cancer metastasis. Recent findings hint that proton radiation may, in addition to offering improved radio-therapeutic targeting, be a means to provide a new dimension for increasing therapeutic benefits for patients by manipulating these tissue-level processes. (authors)

  4. Radiation damage relative to transmission electron microscopy of biological specimens at low temperature: a review

    International Nuclear Information System (INIS)

    Glaeser, R.M.; Taylor, K.A.

    1978-01-01

    When biological specimens are irradiated by the electron beam in the electron microscope, the specimen structure is damaged as a result of molecular excitation, ionization, and subsequent chemical reactions. The radiation damage that occurs in the normal process of electron microscopy is known to present severe limitations for imaging high resolution detail in biological specimens. The question of radiation damage at low temperatures has therefore been investigated with the view in mind of reducing somewhat the rate at which damage occurs. The radiation damage protection found for small molecule (anhydrous) organic compounds is generally rather limited or even non-existent. However, large molecule, hydrated materials show as much as a 10-fold reduction at low temperature in the rate at which radiation damage occurs, relative to the damage rate at room temperature. In the case of hydrated specimens, therefore, low temperature electron microscopy offers an important advantage as part of the overall effort required in obtaining high resolution images of complex biological structures. (author)

  5. Biological effects of ionizing radiation

    International Nuclear Information System (INIS)

    Marko, A.M.

    1981-05-01

    In this review radiation produced by the nuclear industry is placed into context with other sources of radiation in our world. Human health effects of radiation, derivation of standards and risk estimates are reviewed in this document. The implications of exposing the worker and the general population to radiation generated by nuclear power are assessed. Effects of radiation are also reviewed. Finally, gaps in our knowledge concerning radiation are identified and current research on biological effects, on environmental aspects, and on dosimetry of radiation within AECL and Canada is documented in this report. (author)

  6. Applied radiation biology and protection

    International Nuclear Information System (INIS)

    Granier, R.; Gambini, D.-J.

    1990-01-01

    This book grew out of a series of courses in radiobiology and radiation protection which were given to students in schools for radiology technicians, radiation safety officers and to medical students. Topics covered include the sources of ionizing radiation and their interactions with matter; the detection and measurement of ionizing radiation; dosimetry; the biological effects of ionizing radiation; the effects of ionizing radiation on the human body; natural radioexposure; medical radio-exposure; industrial radioexposure of electronuclear origin; radioexposure due to experimental nuclear explosions; radiation protection; and accidents with external and/or internal radio-exposure. (UK)

  7. Chemically-functionalized microcantilevers for detection of chemical, biological and explosive material

    Science.gov (United States)

    Pinnaduwage, Lal A [Knoxville, TN; Thundat, Thomas G [Knoxville, TN; Brown, Gilbert M [Knoxville, TN; Hawk, John Eric [Olive Branch, MS; Boiadjiev, Vassil I [Knoxville, TN

    2007-04-24

    A chemically functionalized cantilever system has a cantilever coated on one side thereof with a reagent or biological species which binds to an analyte. The system is of particular value when the analyte is a toxic chemical biological warfare agent or an explosive.

  8. Propagation and generation of Josephson radiation in superconductor/insulator superlattices

    International Nuclear Information System (INIS)

    Auvil, P.R.; Ketterson, J.B.

    1987-01-01

    The wave propagation and generation characteristics of a metal-insulator superlattice are calculated in a low-field Landau--Ginzburg model, including Josephson coupling through the insulating layers. It is shown that a significant increase in the phase velocity of the electromagnetic waves propagating in the superlattice occurs when the thickness of the superconducting layers becomes much less than the London penetration depth, suggesting that increased output of Josephson radiation may be achieved from such structures. Wave generation via the ac Josephson effect (in the presence of applied dc electric and magnetic fields) is studied for both parallel and series driven multilayer structures

  9. Integrative Radiation Biology

    Energy Technology Data Exchange (ETDEWEB)

    Barcellos-Hoff, Mary Helen [New York University School of Medicine, NY (United States)

    2015-02-27

    We plan to study tissue-level mechanisms important to human breast radiation carcinogenesis. We propose that the cell biology of irradiated tissues reveals a coordinated multicellular damage response program in which individual cell contributions are primarily directed towards suppression of carcinogenesis and reestablishment of homeostasis. We identified transforming growth factor β1 (TGFβ) as a pivotal signal. Notably, we have discovered that TGFβ suppresses genomic instability by controlling the intrinsic DNA damage response and centrosome integrity. However, TGFβ also mediates disruption of microenvironment interactions, which drive epithelial to mesenchymal transition in irradiated human mammary epithelial cells. This apparent paradox of positive and negative controls by TGFβ is the topic of the present proposal. First, we postulate that these phenotypes manifest differentially following fractionated or chronic exposures; second, that the interactions of multiple cell types in tissues modify the responses evident in this single cell type culture models. The goals are to: 1) study the effect of low dose rate and fractionated radiation exposure in combination with TGFβ on the irradiated phenotype and genomic instability of non-malignant human epithelial cells; and 2) determine whether stromal-epithelial interactions suppress the irradiated phenotype in cell culture and the humanized mammary mouse model. These data will be used to 3) develop a systems biology model that integrates radiation effects across multiple levels of tissue organization and time. Modeling multicellular radiation responses coordinated via extracellular signaling could have a significant impact on the extrapolation of human health risks from high dose to low dose/rate radiation exposure.

  10. Perspective: Reaches of chemical physics in biology

    Science.gov (United States)

    Gruebele, Martin; Thirumalai, D.

    2013-01-01

    Chemical physics as a discipline contributes many experimental tools, algorithms, and fundamental theoretical models that can be applied to biological problems. This is especially true now as the molecular level and the systems level descriptions begin to connect, and multi-scale approaches are being developed to solve cutting edge problems in biology. In some cases, the concepts and tools got their start in non-biological fields, and migrated over, such as the idea of glassy landscapes, fluorescence spectroscopy, or master equation approaches. In other cases, the tools were specifically developed with biological physics applications in mind, such as modeling of single molecule trajectories or super-resolution laser techniques. In this introduction to the special topic section on chemical physics of biological systems, we consider a wide range of contributions, all the way from the molecular level, to molecular assemblies, chemical physics of the cell, and finally systems-level approaches, based on the contributions to this special issue. Chemical physicists can look forward to an exciting future where computational tools, analytical models, and new instrumentation will push the boundaries of biological inquiry. PMID:24089712

  11. Perspective: Reaches of chemical physics in biology.

    Science.gov (United States)

    Gruebele, Martin; Thirumalai, D

    2013-09-28

    Chemical physics as a discipline contributes many experimental tools, algorithms, and fundamental theoretical models that can be applied to biological problems. This is especially true now as the molecular level and the systems level descriptions begin to connect, and multi-scale approaches are being developed to solve cutting edge problems in biology. In some cases, the concepts and tools got their start in non-biological fields, and migrated over, such as the idea of glassy landscapes, fluorescence spectroscopy, or master equation approaches. In other cases, the tools were specifically developed with biological physics applications in mind, such as modeling of single molecule trajectories or super-resolution laser techniques. In this introduction to the special topic section on chemical physics of biological systems, we consider a wide range of contributions, all the way from the molecular level, to molecular assemblies, chemical physics of the cell, and finally systems-level approaches, based on the contributions to this special issue. Chemical physicists can look forward to an exciting future where computational tools, analytical models, and new instrumentation will push the boundaries of biological inquiry.

  12. Integrative radiation systems biology

    International Nuclear Information System (INIS)

    Unger, Kristian

    2014-01-01

    Maximisation of the ratio of normal tissue preservation and tumour cell reduction is the main concept of radiotherapy alone or combined with chemo-, immuno- or biologically targeted therapy. The foremost parameter influencing this ratio is radiation sensitivity and its modulation towards a more efficient killing of tumour cells and a better preservation of normal tissue at the same time is the overall aim of modern therapy schemas. Nevertheless, this requires a deep understanding of the molecular mechanisms of radiation sensitivity in order to identify its key players as potential therapeutic targets. Moreover, the success of conventional approaches that tried to statistically associate altered radiation sensitivity with any molecular phenotype such as gene expression proofed to be somewhat limited since the number of clinically used targets is rather sparse. However, currently a paradigm shift is taking place from pure frequentistic association analysis to the rather holistic systems biology approach that seeks to mathematically model the system to be investigated and to allow the prediction of an altered phenotype as the function of one single or a signature of biomarkers. Integrative systems biology also considers the data from different molecular levels such as the genome, transcriptome or proteome in order to partially or fully comprehend the causal chain of molecular mechanisms. An example for the application of this concept currently carried out at the Clinical Cooperation Group “Personalized Radiotherapy in Head and Neck Cancer” of the Helmholtz-Zentrum München and the LMU Munich is described. This review article strives for providing a compact overview on the state of the art of systems biology, its actual challenges, potential applications, chances and limitations in radiation oncology research working towards improved personalised therapy concepts using this relatively new methodology

  13. Physico-chemical studies of radiation effects in cells. Progress report, November 15, 1980-February 14, 1984

    International Nuclear Information System (INIS)

    Powers, E.L.

    1983-01-01

    The primary interest is investigating and understanding the chemical mechanisms involved in radiation-induced cellular damage. Most recently the perturbating devices have been metals which increase, in various ways and modes, the radiation sensitivity of several cell types. While the chief cell type has been the bacterial spore, chosen because of its biological inertness and its hardiness, allowing it to survive the unphysiological conditions of the physical chemist and, thus, inquiry into the free radical mechanisms involved very soon after energy absorption, recently vegetative cells have been introduced. A number of metals have been used and practically all of them sensitize - but to varying degrees. Straight biological techniques such as the measurement of cell survival under various conditions in the different cells have been used, as well as parallel experiments in pulse radiolysis to attack the specific leads in a chemical fashion suggested by the biology

  14. A Paradigm Shift in Low Dose Radiation Biology

    Directory of Open Access Journals (Sweden)

    Z. Alatas

    2015-08-01

    Full Text Available When ionizing radiation traverses biological material, some energy depositions occur and ionize directly deoxyribonucleic acid (DNA molecules, the critical target. A classical paradigm in radiobiology is that the deposition of energy in the cell nucleus and the resulting damage to DNA are responsible for the detrimental biological effects of radiation. It is presumed that no radiation effect would be expected in cells that receive no direct radiation exposure through nucleus. The risks of exposure to low dose ionizing radiation are estimated by extrapolating from data obtained after exposure to high dose radiation. However, the validity of using this dose-response model is controversial because evidence accumulated over the past decade has indicated that living organisms, including humans, respond differently to low dose radiation than they do to high dose radiation. Moreover, recent experimental evidences from many laboratories reveal the fact that radiation effects also occur in cells that were not exposed to radiation and in the progeny of irradiated cells at delayed times after radiation exposure where cells do not encounter direct DNA damage. Recently, the classical paradigm in radiobiology has been shifted from the nucleus, specifically the DNA, as the principal target for the biological effects of radiation to cells. The universality of target theory has been challenged by phenomena of radiation-induced genomic instability, bystander effect and adaptive response. The new radiation biology paradigm would cover both targeted and non-targeted effects of ionizing radiation. The mechanisms underlying these responses involve biochemical/molecular signals that respond to targeted and non-targeted events. These results brought in understanding that the biological response to low dose radiation at tissue or organism level is a complex process of integrated response of cellular targets as well as extra-cellular factors. Biological understanding of

  15. Biological effects of ionizing radiation

    International Nuclear Information System (INIS)

    Heribanova, A.

    1995-01-01

    The basic principles and pathways of effects of ionizing radiation on living organisms and cells are outlined. The following topics are covered: effects of radiation on living matter (direct effects, radical or indirect effects, dual radiation action, and molecular biological theories); effects of radiation on cells and tissues (cell depletion, changes in the cytogenetic information, reparation mechanisms), dose-response relationship (deterministic effects, stochastic effects), and the effects of radiation on man (acute radiation sickness, acute local changes, fetus injuries, non-tumorous late injuries, malignant tumors, genetic changes). (P.A.). 3 tabs., 2 figs., 5 refs

  16. Radiation biology using synchrotron radiation. In relation to radiation chemistry as an initial process

    International Nuclear Information System (INIS)

    Kobayashi, Katsumi

    1995-01-01

    Radiation biology using synchrotron radiation have been investigated, focusing on the mechanism of the formation of molecular damage. This paper introduces recent outcome of these studies. First, the process from imparted energy to the formation of molecular damage is outlined. The previous studies can be largely categorized as dealing with (1) biological effects of inner-shell ionization on elements composing the living body and (2) X-ray energy dependence of biological effects. Bromine and phosphorus are used as elements for the study of inner-cell ionization. In the study on lethal effects of monochromatic soft X-rays on the BrdUMP-incorporated yeast cells, Auger enhancement was found to occur. The first report on the effects of K-shell absorption of cellular phosphorus atoms has revealed that biological effects on cellular lethality and genetic changes was enhanced by 40%. Plasmid DNA and oligonucleotide have been used to study biological effects of vacuum ultraviolet rays to monochromatic soft X-ray, which makes it possible to study strand breaks. Because experimental production of energy required for the formation of double strand breaks has become possible, synchrotron radiation plays a very important role in radiation biological studies. Finally, future issues are presented. (N.K.)

  17. Propagation of stochastic electromagnetic vortex beams through the turbulent biological tissues

    Energy Technology Data Exchange (ETDEWEB)

    Luo, Meilan; Chen, Qi; Hua, Limin; Zhao, Daomu, E-mail: zhaodaomu@yahoo.com

    2014-01-10

    The general analytical expression of the stochastic electromagnetic vortex beams through turbulent biological tissues is derived based on the fractal model. The statistical properties, including the spectral density, the spectral degree of coherence and the spectral degree of polarization are investigated in detail. It can be found that the normalized spectral density of the stochastic electromagnetic vortex beams with higher topological charge is less influenced by turbulence than that with lower topological charge. In addition, the change of the degree of polarization versus propagation distance of the anisotropic vortex beams in biological tissues differs from that of the isotropic vortex beams. The findings might be useful in the investigation of the structures of biological tissues and operation of communication and sensing systems involving biological tissues turbulence channels.

  18. The biological effects of radiation

    International Nuclear Information System (INIS)

    Sykes, D.A.

    1979-01-01

    The hazards of radiations to man are briefly covered in this paper. The natural background sources of radiations are stated and their resulting doses are compared to those received voluntarily by man. The basis of how radiations cause biological damage is given and the resulting somatic effects are shown for varying magnitude of dose. Risk estimates are given for cancer induction and genetic effects are briefly discussed. Finally four case studies of radiation damage to humans are examined exemplifying the symptoms of large doses of radiations [af

  19. Opportunities for Merging Chemical and Biological Synthesis

    Science.gov (United States)

    Wallace, Stephen; Balskus, Emily P.

    2014-01-01

    Organic chemists and metabolic engineers use largely orthogonal technologies to access small molecules like pharmaceuticals and commodity chemicals. As the use of biological catalysts and engineered organisms for chemical production grows, it is becoming increasingly evident that future efforts for chemical manufacture will benefit from the integration and unified expansion of these two fields. This review will discuss approaches that combine chemical and biological synthesis for small molecule production. We highlight recent advances in combining enzymatic and non-enzymatic catalysis in vitro, discuss the application of design principles from organic chemistry for engineering non-biological reactivity into enzymes, and describe the development of biocompatible chemistry that can be interfaced with microbial metabolism. PMID:24747284

  20. Influence of gravitation on the propagation of electromagnetic radiation

    Science.gov (United States)

    Mashhoon, B.

    1975-01-01

    The existence of a general helicity-rotation coupling is demonstrated for electromagnetic waves propagating in the field of a slowly rotating body and in the Goedel universe. This coupling leads to differential focusing of circularly polarized radiation by a gravitational field which is detectable for a rapidly rotating collapsed body. The electromagnetic perturbations and their frequency spectrum are given for the Goedel universe. The spectrum of frequencies is bounded from below by the characteristic rotation frequency of the Goedel universe. If the universe were rotating, the differential focusing effect would be extremely small due to the present upper limit on the anisotropy of the microwave background radiation.

  1. Is ionizing radiation regulated more stringently than chemical carcinogens

    International Nuclear Information System (INIS)

    Travis, C.C.; Pack, S.R.; Hattemer-Frey, H.A.

    1989-01-01

    It is widely believed that United States government agencies regulate exposure to ionizing radiation more stringently than exposure to chemical carcinogens. It is difficult to verify this perception, however, because chemical carcinogens and ionizing radiation are regulated using vastly different strategies. Chemical carcinogens are generally regulated individually. Regulators consider the risk of exposure to one chemical rather than the cumulative radiation exposure from all sources. Moreover, standards for chemical carcinogens are generally set in terms of quantities released or resultant environmental concentrations, while standards for ionizing radiation are set in terms of dose to the human body. Since chemicals and ionizing radiation cannot be compared on the basis of equal dose to the exposed individual, standards regulating chemicals and ionizing radiation cannot be compared directly. It is feasible, however, to compare the two sets of standards on the basis of equal risk to the exposed individual, assuming that standards for chemicals and ionizing radiation are equivalent if estimated risk levels are equitable. This paper compares risk levels associated with current standards for ionizing radiation and chemical carcinogens. The authors do not attempt to determine whether either type of risk is regulated too stringently or not stringently enough but endeavor only to ascertain if ionizing radiation is actually regulated more strictly than chemical carcinogens

  2. Multiscale approach to the physics of radiation damage with ions

    International Nuclear Information System (INIS)

    Surdutovich, E.; Solov'yov, A.

    2014-01-01

    The multiscale approach to the assessment of bio-damage resulting upon irradiation of biological media with ions is reviewed, explained and compared to other approaches. The processes of ion propagation in the medium concurrent with ionization and excitation of molecules, transport of secondary products, dynamics of the medium, and biological damage take place on a number of different temporal, spatial and energy scales. The multiscale approach, a physical phenomenon-based analysis of the scenario that leads to radiation damage, has been designed to consider all relevant effects on a variety of scales and develop an approach to the quantitative assessment of biological damage as a result of irradiation with ions. Presently, physical and chemical effects are included in the scenario while the biological effects such as DNA repair are only mentioned. This paper explains the scenario of radiation damage with ions, overviews its major parts, and applies the multiscale approach to different experimental conditions. On the basis of this experience, the recipe for application of the multiscale approach is formulated. The recipe leads to the calculation of relative biological effectiveness. (authors)

  3. Radiation, chemicals and combined effects

    International Nuclear Information System (INIS)

    Sinclair, W.K.

    1991-01-01

    A brief background has been provided on current carcinogenic risks from ionizing radiation and their magnitude in background circumstances. The magnitude of the risks from possibly carcinogenic chemicals at background levels in air, water and food are surprisingly similar. The exception is, perhaps, for the single source of radon which, while variable, on the average stands out above all other sources. Some basic principles concerning the interaction of combined radiation and chemicals and some practical examples where the two interact synergistically to enhance radiation effects has also been provided. Areas for human research in the future are discussed. (Author)

  4. Phyto chemical and biological studies of certain plants with potential radioprotective activity

    International Nuclear Information System (INIS)

    Sherif, N.H.M.I

    2008-01-01

    One of the promising directions of radiation protection development is the search for natural radioprotective agents.The present work includes: I- Screening of certain edible and medicinal plants growing in Egypt for their radioprotective activities. II- Detailed phyto chemical and biolo-activity studies of the dried leaves of brassaia actinophylla endl. comprising: A-Phyto chemical screening and proximate analysis. B-Investigation of lipoidal matter. C- Isolation, characterization and structure elucidation of phenolic constituents. D- Isolation, characterization and structure elucidation of saponin constituents. E- Evaluation of radioprotective and antitumor activities. I- Evaluation of potential radioprotective activities of certain herbs: In vivo biological screening designed to investigate the radioprotective role of 70% ethanol extract of 11 different herbals was carried out by measuring the lipid peroxide content, as well as the activities of two antioxidant enzymes; viz glutathione, and superoxide dismutase in blood and liver tissues 1 and 7 days after radiation exposure. II : Phyto chemical and biolo-activity studies of the dried leaves of brassaia actinophylla Endl A : preliminary phyto chemical screening, determination and TLC examination of successive extractives. B : Investigation of lipoidal matter. GLC of unsaponifiable matter (USM)

  5. Microbiology and atmospheric processes: chemical interactions of primary biological aerosols

    Directory of Open Access Journals (Sweden)

    L. Deguillaume

    2008-07-01

    Full Text Available This paper discusses the influence of primary biological aerosols (PBA on atmospheric chemistry and vice versa through microbiological and chemical properties and processes. Several studies have shown that PBA represent a significant fraction of air particulate matter and hence affect the microstructure and water uptake of aerosol particles. Moreover, airborne micro-organisms, namely fungal spores and bacteria, can transform chemical constituents of the atmosphere by metabolic activity. Recent studies have emphasized the viability of bacteria and metabolic degradation of organic substances in cloud water. On the other hand, the viability and metabolic activity of airborne micro-organisms depend strongly on physical and chemical atmospheric parameters such as temperature, pressure, radiation, pH value and nutrient concentrations. In spite of recent advances, however, our knowledge of the microbiological and chemical interactions of PBA in the atmosphere is rather limited. Further targeted investigations combining laboratory experiments, field measurements, and modelling studies will be required to characterize the chemical feedbacks, microbiological activities at the air/snow/water interface supplied to the atmosphere.

  6. American Society for Radiation Oncology (ASTRO) Survey of Radiation Biology Educators in U.S. and Canadian Radiation Oncology Residency Programs

    International Nuclear Information System (INIS)

    Rosenstein, Barry S.; Held, Kathryn D.; Rockwell, Sara; Williams, Jacqueline P.; Zeman, Elaine M.

    2009-01-01

    Purpose: To obtain, in a survey-based study, detailed information on the faculty currently responsible for teaching radiation biology courses to radiation oncology residents in the United States and Canada. Methods and Materials: In March-December 2007 a survey questionnaire was sent to faculty having primary responsibility for teaching radiation biology to residents in 93 radiation oncology residency programs in the United States and Canada. Results: The responses to this survey document the aging of the faculty who have primary responsibility for teaching radiation biology to radiation oncology residents. The survey found a dramatic decline with time in the percentage of educators whose graduate training was in radiation biology. A significant number of the educators responsible for teaching radiation biology were not fully acquainted with the radiation sciences, either through training or practical application. In addition, many were unfamiliar with some of the organizations setting policies and requirements for resident education. Freely available tools, such as the American Society for Radiation Oncology (ASTRO) Radiation and Cancer Biology Practice Examination and Study Guides, were widely used by residents and educators. Consolidation of resident courses or use of a national radiation biology review course was viewed as unlikely by most programs. Conclusions: A high priority should be given to the development of comprehensive teaching tools to assist those individuals who have responsibility for teaching radiation biology courses but who do not have an extensive background in critical areas of radiobiology related to radiation oncology. These findings also suggest a need for new graduate programs in radiobiology.

  7. Radiation 2006. In association with the Polymer Division, Royal Australian Chemical Institute. Incorporating the 21st AINSE Radiation Chemistry Conference and the 18th Radiation Biology Conference, conference handbook

    International Nuclear Information System (INIS)

    2006-04-01

    This conference facilitates a meeting of scientists and researchers to present and discuss their newest areas of research and investigation. It incorporates presentations on medical radiation therapies, biological effects of radiation, future areas of concern and nanotechnology

  8. Coupling chemical and biological catalysis: a flexible paradigm for producing biobased chemicals.

    Science.gov (United States)

    Schwartz, Thomas J; Shanks, Brent H; Dumesic, James A

    2016-04-01

    Advances in metabolic engineering have allowed for the development of new biological catalysts capable of selectively de-functionalizing biomass to yield platform molecules that can be upgraded to biobased chemicals using high efficiency continuous processing allowed by heterogeneous chemical catalysis. Coupling these disciplines overcomes the difficulties of selectively activating COH bonds by heterogeneous chemical catalysis and producing petroleum analogues by biological catalysis. We show that carboxylic acids, pyrones, and alcohols are highly flexible platforms that can be used to produce biobased chemicals by this approach. More generally, we suggest that molecules with three distinct functionalities may represent a practical upper limit on the extent of functionality present in the platform molecules that serve as the bridge between biological and chemical catalysis. Copyright © 2016 Elsevier Ltd. All rights reserved.

  9. The yield, processing, and biological consequences of clustered DNA damage induced by ionizing radiation

    International Nuclear Information System (INIS)

    Shikazono, Naoya; Noguchi, Miho; Fujii, Kentaro; Urushibara, Ayumi; Yokoya, Akinari

    2009-01-01

    After living cells are exposed to ionizing radiation, a variety of chemical modifications of DNA are induced either directly by ionization of DNA or indirectly through interactions with water-derived radicals. The DNA lesions include single strand breaks (SSB), base lesions, sugar damage, and apurinic/apyrimidinic sites (AP sites). Clustered DNA damage, which is defined as two or more of such lesions within one to two helical turns of DNA induced by a single radiation track, is considered to be a unique feature of ionizing radiation. A double strand break (DSB) is a type of clustered DNA damage, in which single strand breaks are formed on opposite strands in close proximity. Formation and repair of DSBs have been studied in great detail over the years as they have been linked to important biological endpoints, such as cell death, loss of genetic material, chromosome aberration. Although non-DSB clustered DNA damage has received less attention, there is growing evidence of its biological significance. This review focuses on the current understanding of (1) the yield of non-DSB clustered damage induced by ionizing radiation (2) the processing, and (3) biological consequences of non-DSB clustered DNA damage. (author)

  10. Dietary antioxidant synergy in chemical and biological systems.

    Science.gov (United States)

    Wang, Sunan; Zhu, Fan

    2017-07-24

    Antioxidant (AOX) synergies have been much reported in chemical ("test-tube" based assays focusing on pure chemicals), biological (tissue culture, animal and clinical models), and food systems during the past decade. Tentative synergies differ from each other due to the composition of AOX and the quantification methods. Regeneration mechanism responsible for synergy in chemical systems has been discussed. Solvent effects could contribute to the artifacts of synergy observed in the chemical models. Synergy in chemical models may hardly be relevant to biological systems that have been much less studied. Apparent discrepancies exist in understanding the molecular mechanisms in both chemical and biological systems. This review discusses diverse variables associated with AOX synergy and molecular scenarios for explanation. Future research to better utilize the synergy is suggested.

  11. Activities in biological radiation research at the AGF

    International Nuclear Information System (INIS)

    1984-01-01

    The AGF is working on a wide spectrum of biological radiation research, with the different scientific disciplines contributing different methodologies to long-term research projects. The following fields are studied: 1. Molecular and cellular modes of action of radiation. 2. Detection and characterisation of biological radiation damage, especially in humans. 3. Medical applications of radiation effects. 4. Concepts and methods of radiation protection. The studies will lead to suggestions for radiation protection and improved radiotherapy. They may also contribute to the development of environmental protection strategies. (orig./MG) [de

  12. Fractional Calculus-Based Modeling of Electromagnetic Field Propagation in Arbitrary Biological Tissue

    Directory of Open Access Journals (Sweden)

    Pietro Bia

    2016-01-01

    Full Text Available The interaction of electromagnetic fields and biological tissues has become a topic of increasing interest for new research activities in bioelectrics, a new interdisciplinary field combining knowledge of electromagnetic theory, modeling, and simulations, physics, material science, cell biology, and medicine. In particular, the feasibility of pulsed electromagnetic fields in RF and mm-wave frequency range has been investigated with the objective to discover new noninvasive techniques in healthcare. The aim of this contribution is to illustrate a novel Finite-Difference Time-Domain (FDTD scheme for simulating electromagnetic pulse propagation in arbitrary dispersive biological media. The proposed method is based on the fractional calculus theory and a general series expansion of the permittivity function. The spatial dispersion effects are taken into account, too. The resulting formulation is explicit, it has a second-order accuracy, and the need for additional storage variables is minimal. The comparison between simulation results and those evaluated by using an analytical method based on the Fourier transformation demonstrates the accuracy and effectiveness of the developed FDTD model. Five numerical examples showing the plane wave propagation in a variety of dispersive media are examined.

  13. Use of medaka as a tool in studies of radiation effects and chemical carcinogenesis

    International Nuclear Information System (INIS)

    Hyodo-Taguchi, Y.; Aoki, K.; Matsudaira, H.

    1982-01-01

    The medaka, Oryzias latipes, a small freshwater oviparous fish, is common in Japan and found in some parts of Asia. Adult fish are 3.0-3.5 cm long and weigh 0.5-0.7 g. The small fish have been used extensively in this laboratory for analysis of radiation effects and for study of chemical carcinogenesis. These fish are relatively easy to rear and their reproductive biology is well known. Recently, inbred strains of the fish have been established by full sister-brother mating. In this report, we will review experimental results using medaka in studies of : 1) radiation effects on spermatogenesis, and 2) induction of hepatic tumors by MAM acetate, we will also review use of medaka in related studies of radiation effects and chemical carcinogenesis. (author)

  14. Cutaneous reactions in nuclear, biological and chemical warfare

    Directory of Open Access Journals (Sweden)

    Arora Sandeep

    2005-03-01

    Full Text Available Nuclear, biological and chemical warfare have in recent times been responsible for an increasing number of otherwise rare dermatoses. Many nations are now maintaining overt and clandestine stockpiles of such arsenal. With increasing terrorist threats, these agents of mass destruction pose a risk to the civilian population. Nuclear and chemical attacks manifest immediately while biological attacks manifest later. Chemical and biological attacks pose a significant risk to the attending medical personnel. The large scale of anticipated casualties in the event of such an occurrence would need the expertise of all physicians, including dermatologists, both military and civilian. Dermatologists are uniquely qualified in this respect. This article aims at presenting a review of the cutaneous manifestations in nuclear, chemical and biological warfare and their management.

  15. Postgraduate studies in radiation biology in Europe

    International Nuclear Information System (INIS)

    Trott, K.R.; Lohmann, P.H.M.; Zeeland, A.A. van; Natarajan, A.T.; Schibilla, H.; Chadwick, K.; Kellerer, A.M.; Steinhaeusler, F.

    1998-01-01

    The present system of radiobiological research in universities and research centres is no longer able to train radiobiologists who have a comprehensive understanding of the entire field of radiation biology including both 'classical' and molecular radiation biology. However, such experts are needed in view of the role radiation protection plays in our societies. No single institution in Europe could now run a 1-year, full-time course which covers all aspects of the radiobiological basis of radiation protection. Therefore, a cooperative action of several universities from different EU member states has been developed and is described herein. (orig.)

  16. Biological effects of ionizing radiation - changing worker attitudes

    International Nuclear Information System (INIS)

    Johnson, N.; Schenley, C.

    1989-01-01

    Training Resources and Data Exchange (TRADE) Radiation Protection Training Special Interest Group has taken an innovative approach to providing DOE contractors with radiation worker training material information. Newly-hired radiation workers may be afraid to work near radiation and long-term radiation workers may become indifferent to the biological hazard of radiation. Commercially available training material is often presented at an inappropriate technical level or in an uninteresting style. These training problems have been addressed in the DOE system through development of a training videotape and supporting material package entitled Understanding Ionizing Radiation and its Biological Effects. The training package, developed and distributed by TRADE specifically to meet the needs of DOE contractor facilities, contains the videotape and accompanying paper supporting materials designed to assist the instructor. Learning objectives, presentation suggestion for the instructor, trainee worksheets, guided discussion questions, and trainee self-evaluation sheets are included in the training package. DOE contractors have agreed that incorporating this training module into radiation worker training programs enhances the quality of the training and increase worker understanding of the biological effects of ionizing radiation

  17. International Journal of Biological and Chemical Sciences: Contact

    African Journals Online (AJOL)

    International Journal of Biological and Chemical Sciences: Contact. Journal Home > About the Journal > International Journal of Biological and Chemical Sciences: Contact. Log in or Register to get access to full text downloads.

  18. BYSTANDER EFFECTS, GENOMIC INSTABILITY, ADAPTIVE RESPONSE AND CANCER RISK ASSESSMENT FOR RADIATION AND CHEMICAL EXPOSURES

    Science.gov (United States)

    There is an increased interest in utilizing mechanistic data in support of the cancer risk assessment process for ionizing radiation and environmental chemical exposures. In this regard the use of biologically based dose-response models is particularly advocated. The aim is to pr...

  19. Challenges and opportunities in synthetic biology for chemical engineers.

    Science.gov (United States)

    Luo, Yunzi; Lee, Jung-Kul; Zhao, Huimin

    2013-11-15

    Synthetic biology provides numerous great opportunities for chemical engineers in the development of new processes for large-scale production of biofuels, value-added chemicals, and protein therapeutics. However, challenges across all scales abound. In particular, the modularization and standardization of the components in a biological system, so-called biological parts, remain the biggest obstacle in synthetic biology. In this perspective, we will discuss the main challenges and opportunities in the rapidly growing synthetic biology field and the important roles that chemical engineers can play in its advancement.

  20. International Journal of Biological and Chemical Sciences: About ...

    African Journals Online (AJOL)

    International Journal of Biological and Chemical Sciences: About this journal. Journal Home > International Journal of Biological and Chemical Sciences: About this journal. Log in or Register to get access to full text downloads.

  1. Comparative study on biological effects of gamma-radiation and volatile organic compound with the plant bioassay

    International Nuclear Information System (INIS)

    Shin, H. S.; Lee, J. H.; Kim, J. G.

    2003-01-01

    This research examined the presence of hazardous materials in chemical workplace field by means of an integrated biological monitoring. The pollen mother cells (PMC) of Tradescantia are very sensitive to chemical toxicants or ionizing radiation, and thus can be used as a biological end- point as sessing their effect. A parallel series of experiment using five increasing doses of gamma- ray at 10, 20, 30, 40 and 50 cGy was conducted. The MCN frequencies showed a good dose-response relationship in the range of radiation applied and yielded a correlation coefficient of 0.95. On the other hand, the MCN frequency resulted in a good response to exposure time in the workplace field. In case of in situ monitoring with the Tradescantia micronucleus assay, the frequencies were 6.2± 0.5, 8.2±1.0, and 15.7± 0.8 MCN/ 100 tetrads for 2, 6, and 9 hours exposure, respectively. Inhalation of the workplace air by workers may result in chronic damage to their health as proven by micronucleus formations in Tradescantia pollen mother cells. The combination of chemical/ biological monitoring is very effective to evaluate hazardous materials in workplace field and can be alternatively used for screening hazardous materials

  2. Archives: International Journal of Biological and Chemical Sciences

    African Journals Online (AJOL)

    Items 1 - 50 of 61 ... Archives: International Journal of Biological and Chemical Sciences. Journal Home > Archives: International Journal of Biological and Chemical Sciences. Log in or Register to get access to full text downloads.

  3. Challenges and opportunities in synthetic biology for chemical engineers

    Science.gov (United States)

    Luo, Yunzi; Lee, Jung-Kul; Zhao, Huimin

    2012-01-01

    Synthetic biology provides numerous great opportunities for chemical engineers in the development of new processes for large-scale production of biofuels, value-added chemicals, and protein therapeutics. However, challenges across all scales abound. In particular, the modularization and standardization of the components in a biological system, so-called biological parts, remain the biggest obstacle in synthetic biology. In this perspective, we will discuss the main challenges and opportunities in the rapidly growing synthetic biology field and the important roles that chemical engineers can play in its advancement. PMID:24222925

  4. Synthetic biology expands chemical control of microorganisms.

    Science.gov (United States)

    Ford, Tyler J; Silver, Pamela A

    2015-10-01

    The tools of synthetic biology allow researchers to change the ways engineered organisms respond to chemical stimuli. Decades of basic biology research and new efforts in computational protein and RNA design have led to the development of small molecule sensors that can be used to alter organism function. These new functions leap beyond the natural propensities of the engineered organisms. They can range from simple fluorescence or growth reporting to pathogen killing, and can involve metabolic coordination among multiple cells or organisms. Herein, we discuss how synthetic biology alters microorganisms' responses to chemical stimuli resulting in the development of microbes as toxicity sensors, disease treatments, and chemical factories. Copyright © 2015 Elsevier Ltd. All rights reserved.

  5. Research in radiation biology, in the environment, and in radiation protection at CRNL

    International Nuclear Information System (INIS)

    Marko, A.M.; Myers, D.K.; Ophel, I.L.; Cowper, G.; Newcombe, H.B.

    1978-01-01

    Research in radiation biology at CRNL is concerned with: evaluation of the effects of low doses of radiation upon humans and other living organisms; the development of new methods for detecting the effects of radiation exposure in large populations; the continued development of improved methods by which radiation levels can be measured accurately and reliably; and evaluation of the effects of nuclear power use upon the environment. The present report summarizes our background knowledge of radiation hazards and describes current research activities in Biology and Health Physics Division at CRNL. (author)

  6. View of environmental radiation effects from the study of radiation biology in C. elegans

    International Nuclear Information System (INIS)

    Sakashita, Tetsuya

    2011-01-01

    Caenorhabditis (C.) elegans is a non-parasitic soil nematode and is well-known as a unique model organism, because of its complete cell-lineage, nervous network and genome sequences. Also, C. elegans can be easily manipulated in the laboratory. These advantages make C. elegans as a good in vivo model system in the field of radiation biology. Radiation effects in C. elegans have been studied for three decades. Here, I briefly review the current knowledge of the biological effects of ionizing irradiation in C. elegans with a scope of environmental radiation effects. Firstly, basic information of C. elegans as a model organism is described. Secondly, historical view is reported on the study of radiation biology in C. elegans. Thirdly, our research on learning behavior is presented. Finally, an opinion of the use of C. elegans for environmental radiation protection is referred. I believe that C. elegans may be a good promising in vivo model system in the field of environmental radiation biology. (author)

  7. Applications of Synchrotron Radiation Micro Beams in Cell Micro Biology and Medicine

    CERN Document Server

    Ide-Ektessabi, Ari

    2007-01-01

    This book demonstrates the applications of synchrotron radiation in certain aspects of cell microbiology, specifically non-destructive elemental analyses, chemical-state analyses and imaging (distribution) of the elements within a cell. The basics for understanding and applications of synchrotron radiation are also described to make the contents easier to be understood for a wide group of researchers in medical and biological sciences who might not be familiar with the physics of synchrotron radiation. The two main techniques that are discussed in this book are the x-ray fluorescence spectroscopy (XRF) and the x-ray fine structure analysis (XAFS). Application of these techniques in investigations of several important scientific fields, such as neurodegeneration and other diseases related to cell malfunctioning, are demonstrated in this book.

  8. Ionising radiation - physical and biological effects

    International Nuclear Information System (INIS)

    Holter, Oe.; Ingebretsen, F.; Parr, H.

    1979-01-01

    The physics of ionising radiation is briefly presented. The effects of ionising radiation on biological cells, cell repair and radiosensitivity are briefly treated, where after the effects on man and mammals are discussed and related to radiation doses. Dose limits are briefly discussed. The genetic effects are discussed separately. Radioecology is also briefly treated and a table of radionuclides deriving from reactors, and their radiation is given. (JIW)

  9. Low level radiation: biological effects

    International Nuclear Information System (INIS)

    Loken, M.K.

    1983-01-01

    It is imperative that physicians and scientists using radiations in health care delivery continue to assess the benefits derived, vs. potential risk, to patients and radiation workers being exposed to radiation in its various forms as part of our health delivery system. Insofar as possible we should assure our patients and ourselves that the benefits outweigh the potential hazards involved. Inferences as to the possible biological effects of low level radiation are generally based on extrapolations from those effects observed and measured following acute exposures to considerably higher doses of radiation. Thus, in order to shed light on the question of the possible biological effects of low level radiation, a wide variety of studies have been carried out using cells in culture and various species of plant and animal life. This manuscript makes reference to some of those studies with indications as to how and why the studies were done and the conclusions that might be drawn there from. In addition reference is made to the handling of this information by scientists, by environmentalists, and by the news media. Unfortunately, in many instances the public has been misled by what has been said and/or written. It is hoped that this presentation will provide an understandable and reasonable perspective on the various appropriate uses of radiation in our lives and how such uses do provide significant improvement in our health and in our quality of life

  10. Acoustic wave propagation in fluids with coupled chemical reactions

    International Nuclear Information System (INIS)

    Margulies, T.S.; Schwarz, W.H.

    1984-08-01

    This investigation presents a hydroacoustic theory which accounts for sound absorption and dispersion in a multicomponent mixture of reacting fluids (assuming a set of first-order acoustic equations without diffusion) such that several coupled reactions can occur simultaneously. General results are obtained in the form of a biquadratic characteristic equation (called the Kirchhoff-Langevin equation) for the complex propagation variable chi = - (α + iω/c) in which α is the attenuation coefficient, c is the phase speed of the progressive wave and ω is the angular frequency. Computer simulations of sound absorption spectra have been made for three different chemical systems, each comprised of two-step chemical reactions using physico-chemical data available in the literature. The chemical systems studied include: (1) water-dioxane, (2) aqueous solutions of glycine and (3) cobalt polyphosphate mixtures. Explicit comparisons are made between the exact biquadratic characteristic solution and the approximate equation (sometimes referred to as a Debye equation) previously applied to interpret the experimental data for the chemical reaction contribution to the absorption versus frequency. The relative chemical reaction and classical viscothermal contributions to the sound absorption are also presented. Several discrepancies that can arise when estimating thermodynamic data (chemical reaction heats or volume changes) for multistep chemical reaction systems when making dilute solution or constant density assumptions are discussed

  11. European Society for Radiation Biology 21. annual meeting

    International Nuclear Information System (INIS)

    1988-01-01

    The volume contains about 100 abstracts of lectures presented to the conference covering a large variety of topics like: Radiobiology as a base for radiotherapy, radiation carcinogenesis and cellular effects, late and secondary effects of radiotherapy, radioprotection and radiosensitization, heavy ions in radiobiology and space research, microdosimetry and biological dosimetry, radiation effects on the mature and the developing central nervous system, DNA damage and repair and cellular mutations, the imact of radiation on the environment, free radicals in radiation biology

  12. [Chemical, physical and biological risks in law enforcement].

    Science.gov (United States)

    Magrini, Andrea; Grana, Mario; Vicentini, Laura

    2014-01-01

    Chemical, physical and biological risks among public safety and security forces. Law enforcement personnel, involved in routine tasks and in emergency situations, are exposed to numerous and several occupational hazards (chemical, physical and biological) whith likely health and security consequences. These risks are particularly high when the organization and preparation are inadequate, there is a lacking or insufficient coordination, information, education and communication and safety and personal protective equipment are inadequate or insufficient. Despite the objective difficulties, caused by the actual special needs related to the service performed or the organizational peculiarities, the risk identification and assessment is essential for worker health and safety of personnel, as provided for by Legislative Decree no. 81/2008. Chemical risks include airborne pollutants due to vehicular traffic (carbon monoxide, ultrafine particles, benzene, polycyclic aromatic hydrocarbons, aldehydes, nitrogen and sulfur oxides, lead), toxic gases generated by combustion process following fires (aromatic hydrocarbons, PAHs, dioxins and furans, biphenyls, formaldehyde, metals and cyanides), substances emitted in case of chemical accidents (solvents, pesticides, toxic gases, caustics), drugs (methylamphetamine), riot control agents and self-defence spray, lead at firing ranges, and several materials and reagents used in forensic laboratory. The physical hazards are often caused by activities that induce biomechanical overload aid the onset of musculoskeletal disorders, the use of visual display terminals and work environments that may expose to heat stress and discomfort, high and low pressure, noise, vibrations, ionizing and non-ionizing radiation. The main biological risks are blood-borne diseases (viral hepatitis, AIDS), airborne diseases (eg, tuberculosis, meningitis, SARS, anthrax), MRSA, and vector-borne diseases. Many of these risk factors are unavoidable or are not

  13. Galaxy formation with radiative and chemical feedback

    NARCIS (Netherlands)

    Graziani, L.; Salvadori, S.; Schneider, R.; Kawata, D.; de Bennassuti, M.; Maselli, A.

    Here we introduce GAMESH, a novel pipeline that implements self-consistent radiative and chemical feedback in a computational model of galaxy formation. By combining the cosmological chemical-evolution model GAMETE with the radiative transfer code CRASH, GAMESH can post-process realistic outputs of

  14. Biological basis of chemo-radiation

    International Nuclear Information System (INIS)

    Mornex, F.; Van Houtte, P.; Cosset, J.M.

    1997-01-01

    Radiation therapy has been for years treatment of choice of locally advanced non small cell lung cancer. Improvement due to the combination of radiation and chemotherapy has been shown recently through several randomized trials and a recent meta-analysis. These results may be explained by biological mechanisms, yet un-completely explored, which are detailed in this review and applied to lung cancer. The optimal combination scheme is not yet defined, even trough the concurrent approach is promising, at the expense of an increased toxicity which is the limiting factor of treatment escalation doses. Biological findings and future results of randomized trials will hopefully open new avenues in the therapeutic strategy of this poor prognosis disease. (authors)

  15. Radiation-chemical degradation of chloroform in water solutions

    International Nuclear Information System (INIS)

    Ahmadov, S.A.; Gurbanov, M.A.; Iskenderova, Z.I.; Abdullayev, E.T.; Ibadov, N.A.

    2006-01-01

    Full text: Chloroform is the major chlorine-containing compound forming at chlorination of drinking water. As our basic water resources of Kur and Araz rivers are mostly polluted along the territory of the neighbour republics their chlorination for the purpose of biological purification can result in forming of chloroform. Unfortunately, there are only poor data about containing of chloroform in drinking water in the Republic, however the particular problem is to develop new methods of drinking water purification from chloroform, taking into account the high toxicity of this compounds. Appropriate works indicate that radiation-chemical processing can mostly reduce the concentration of chloroform in drinking water. The purification degree can achieve 95-98 percent. This work studies the tendency of chloroform decomposition at its radiolysis processes in water solutions. The concentration of chloroform changed in the range of 0,03-1 weight percentage. Taking into account the dissolvability of chloroform in water solutions it can be said that examined water solutions are homogeneous. Following advancements are studied: 1) Determination of radiation-chemical yield of chloroform decomposition at its various initial concentrations; 2) Impact of adsorbed dose on pH of solutions; 3) Formation of by-products. It is set that radiation-chemical output of chloroform decomposition is equal to 3 * 10 - 3 - 125 mol/100 ev. The high yield of chloroform decomposition can be connected with the chain process of oxidation with presence of dissolved oxygen. However, taking into account the fact that at its water radiolysis the yield of active particles of OH, e - aq, H-atoms does not exceed 6-7 particles/100 ev, the observed high yield can be explained only with the chain process with presence of dissolved oxygen

  16. Study of biological effect of radiation

    International Nuclear Information System (INIS)

    Li Guisheng

    1992-01-01

    The some progress on the study of biological effect for protract exposure to low dose rate radiation is reported, and it is indicated that the potential risk of this exposure for the human health and the importance of the routine monitoring of radiation dose for various nuclear installations. The potential exposure to the low dose rate radiation would attract people's extra attention

  17. In vitro propagation of Cypripedium guttatum using immature seed based on cumulative solar radiation after pollination

    International Nuclear Information System (INIS)

    Sasaki, Y.

    2000-01-01

    Cypripedium guttatum is one of the most endangered orchids in Japan. In vitro propagation is an important approach for conservation of the plant species. Generally, Cypripedium in vitro propagation is unstable, especially using immature seeds. Therefore, an in vitro propagation system that protocorm produces stable germination is required. In this study, one of the weather factors was tested to obtain stable immmature seeds for seedling production. From statistical analysis of the weather data, it was suggested that solar radiation affected the ripening of Cypripedium seed. From simulations of cumulative solar radiation, a seed 46 days after pollination is suitable for in vitro propagation in Akita. Using a seed 47 days after pollination of Cypripedium guttatum, seedlings were grown in hormone free 1/3 MS agar medium. In the case of adding 0.2 mg/L BAP, multiple shoots were observed. For root elongation of the seedling, hormone free medium was preferable to adding 0.2 mg/L NAA

  18. Synchrotron Radiation in Biology and Medicine

    International Nuclear Information System (INIS)

    Pelka, J.B.

    2008-01-01

    This work is focused on a present status of synchrotron radiation X-ray applications in medicine and biology to imaging, diagnostics, and radio- therapy. Properties of X-ray beams generated by synchrotron sources are compared with radiation produced by classical laboratory X-ray tubes. A list of operating and planned synchrotron facilities applicable to biomedical purposes is given, together with their basic characteristics. A concise overview of typical X-ray synchrotron techniques in biology and medicine is carried out with discussion of their specific properties and examples of typical results. (author)

  19. Propagating self-sustained annealing of radiation-induced interstitial complexes

    International Nuclear Information System (INIS)

    Bokov, P M; Selyshchev, P A

    2016-01-01

    A propagating self-sustained annealing of radiation induced defects as a result of thermal-concentration instability is studied. The defects that are considered in the model are complexes. Each of them consists of one atom of impunity and of one interstitial atom. Crystal with defects has extra energy which is transformed into heat during defect annealing. Simulation of the auto-wave of annealing has been performed. The front and the speed of the auto-wave have been obtained. It is shown that annealing occurs in a narrow region of time and space. There are two kinds of such annealing behaviour. In the first case the speed of the auto-wave oscillates near its constant mean value and the front of temperature oscillates in a complex way. In the second case the speed of propagation is constant and fronts of temperature and concentration look like sigmoid functions. (paper)

  20. Chemical effects of ionizing radiation and sonic energy in the context of chemical evolution

    International Nuclear Information System (INIS)

    Negron Mendoza, A.; Albarran, G.

    1992-01-01

    Ionizing radiation and sonic energy are considered as sources for chemical evolution processes. These sources have still a modest place in the interdisciplinary approach for the prebiological synthesis of organic compounds. Studies in Radiation Chemistry and Sonochemistry can provide a deeper insight into the chemical processes that may have importance for prebiotic chemistry. The present work concerns the analysis of some chemical reactions induced by ionizing radiation or cavitation in aqueous media that may be relevant to chemical evolution studies. (author)

  1. Biological radiation effects and radioprotection standards

    International Nuclear Information System (INIS)

    Clerc, H.

    1991-03-01

    In this report, after recalling the mode of action of ionizing radiations, the notions of dose, dose equivalents and the values of natural irradiation, the author describes the biological radiation effects. Then he presents the ICRP recommendations and their applications to the french radioprotection system

  2. Partial coherence and imperfect optics at a synchrotron radiation source modeled by wavefront propagation

    Science.gov (United States)

    Laundy, David; Alcock, Simon G.; Alianelli, Lucia; Sutter, John P.; Sawhney, Kawal J. S.; Chubar, Oleg

    2014-09-01

    A full wave propagation of X-rays from source to sample at a storage ring beamline requires simulation of the electron beam source and optical elements in the beamline. The finite emittance source causes the appearance of partial coherence in the wave field. Consequently, the wavefront cannot be treated exactly with fully coherent wave propagation or fully incoherent ray tracing. We have used the wavefront code Synchrotron Radiation Workshop (SRW) to perform partially coherent wavefront propagation using a parallel computing cluster at the Diamond Light Source. Measured mirror profiles have been used to correct the wavefront for surface errors.

  3. The use of nuclear reactor in radiation biology

    International Nuclear Information System (INIS)

    Ujeno, Yowri

    1991-01-01

    The Kyoto University Reactor (KUR) is widely used not only in biology, but also in applied biology, today. These studies were surveyed in the present paper and the future possibility to use KUR in radiation biology was discussed. The researches on the effects of thermal neutrons on various normal tissues, the biological effects of neutrons except thermal neutrons, especially intermediate neutrons between thermal and high speed neutrons or cold neutrons, the adaptive response of cells to thermal neutron radiation, the application of nuclear reactor-produced radionuclides including 195m Pt to biology, and the mutation in botanical science and so on, should be continued using nuclear reactor. The necessity of nuclear reactor in biology and applied biology is emphasized. (author)

  4. Industrial chemical exposure: guidelines for biological monitoring

    National Research Council Canada - National Science Library

    Lauwerys, Robert R; Hoet, Perrine

    2001-01-01

    .... With Third Edition of Industrial Chemical Exposure you will understand the objectives of biological monitoring, the types of biological monitoring methods, their advantages and limitations, as well...

  5. Biological indicators of radiation quality

    International Nuclear Information System (INIS)

    Bender, M.A.; Wong, R.M.A.

    1982-01-01

    The induction of many biological effects by high linear energy transfer (LET) radiation is strikingly different in one or two respects from the induction by acute low-LET radiation. If the acute low-LET dose-effect curve is of the usual quadratic form, it becomes linear as LET increases. In any case the linear slope increases as LET increases; that is, the relative biological effectiveness (RBE) increases. Both changes might be exploited as biological indicators of whether or not the recent recalculations of dose and of neutron contribution to dose at Hiroshima and Nagasaki seem consistent with the epidemiological observations. The biological end points that have been extensively studied in survivors include acute effects, growth and development after in utero or childhood exposure, genetic and cytogenetic effects in offspring, somatic chromosomal aberrations in survivors, and, of course, cancers, including leukemia. No significant indication among offspring of genetic or cytogenetic effects attributable to parental exposure has been found. Among the remaining end points, only the data on somatic chromosomal aberrations and on cancers appear robust enough to allow one to draw definite inferences by comparing experiences at the two cities

  6. Mössbauer spectroscopy: epoch-making biological and chemical applications

    Czech Academy of Sciences Publication Activity Database

    Lančok, Adriana; Volfová, Lenka

    2017-01-01

    Roč. 89, č. 4 (2017), s. 461-470 ISSN 0033-4545. [International Conference Solid State Chemistry 2016 /12./. Prague, 18.09.2016-23.09.2016] R&D Projects: GA MŠk(CZ) LO1409; GA MŠk(CZ) LM2015088 Grant - others:FUNBIO(XE) CZ.2.16/3.1.00/21568 Institutional support: RVO:61388980 ; RVO:68378271 Keywords : biological tissue * boron chemistry * Fe2+ and Fe3+ * Mössbauer spectrometry * vivianite Subject RIV: CA - Inorganic Chemistry ; BM - Solid Matter Physics ; Magnetism (FZU-D) OBOR OECD: Inorganic and nuclear chemistry ; Atomic, molecular and chemical physics (physics of atoms and molecules including collision, interaction with radiation, magnetic resonances, Mössbauer effect) (FZU-D) Impact factor: 2.626, year: 2016

  7. Survey of chemical speciation of trace elements using synchrotron radiation

    International Nuclear Information System (INIS)

    Gordon, B.M.

    1985-01-01

    Information concerning the chemical state of trace elements in biological systems generally has not been available. Such information for toxic elements and metals in metalloproteins could prove extremely valuable in the elucidation of their metabolism and other biological processes. The shielding of core electrons by binding electrons affect the energy required for creating inner-shell holes. Furthermore, the molecular binding and the symmetry of the local environment of an atom affect the absorption spectrum in the neighborhood of the absorption edge. X-ray absorption near-edge structure (XANES) using synchrotron radiation excitation can be used to provide chemical speciation information for trace elements at concentrations as low as 10 ppM. The structure and position of the absorption curve in the region of an edge can yield vital data about the local structure and oxidation state of the trace element in question. Data are most easily interpreted by comparing the observed edge structure and position with those of model compounds of the element covering the entire range of possible oxidation states. Examples of such analyses are reviewed. 14 refs., 1 fig

  8. Theory of light transfer in food and biological materials

    Science.gov (United States)

    In this chapter, we first define the basic radiometric quantities that are needed for describing light propagation in food and biological materials. Radiative transfer theory is then derived, according to the principle of the conservation of energy. Because the radiative transfer theory equation is ...

  9. Gamma radiation effects on some nutritional and physico-chemical characteristics of stored beans (Phaseolus vulgaris L.)

    International Nuclear Information System (INIS)

    Mancini Filho, J.

    1990-01-01

    The radiation effects on physico-chemical and nutritional characteristics of three Brazilian varieties of beans (Phaseolus vulgaris, L.) - Catu, Rajado and Carioca -were studied. The analytical parameters were obtained by the determination of soaking and cooking times, biological value in rats, protein electrophoretic profile, reductors sugars, oligosaccharides, fiber and fatty acids content. Also, amyloglucosidase, phytohemagglutinins, α-amylase and tryptic inhibitors activities were analysed. It was observed the gamma radiation until determined doses promotes changes on those parameters subsequently reducing substantially the cooking time without modification of the biological value of the proteins. This alteration was particularly noticed in the hard-to-cook beans. (author)

  10. Organic chemistry and biology: chemical biology through the eyes of collaboration.

    Science.gov (United States)

    Hruby, Victor J

    2009-12-18

    From a scientific perspective, efforts to understand biology including what constitutes health and disease has become a chemical problem. However, chemists and biologists "see" the problems of understanding biology from different perspectives, and this has retarded progress in solving the problems especially as they relate to health and disease. This suggests that close collaboration between chemists and biologists is not only necessary but essential for progress in both the biology and chemistry that will provide solutions to the global questions of biology. This perspective has directed my scientific efforts for the past 45 years, and in this overview I provide my perspective of how the applications of synthetic chemistry, structural design, and numerous other chemical principles have intersected in my collaborations with biologists to provide new tools, new science, and new insights that were only made possible and fruitful by these collaborations.

  11. Refractometry and interferometry in chemical analysis; Refractometrie et interferometrie en analyse chimique

    Energy Technology Data Exchange (ETDEWEB)

    Veret, C [Faculte des Sciences de Paris, 75 (France)

    2000-03-01

    In vacuum, an electromagnetic radiation is propagated at a constant velocity. But, when it has to pass through a physical medium, it is submitted to different interactions (for instance: absorption, diffusion, refraction, polarization, dispersion, fluorescence) which lead to a modification of its propagation. In the frequency ranges of the radiation for which the absorption is not very important, the modifications of the propagation velocity of a radiation can bring data on the nature and/or the physical conditions (pressure, temperature) of a medium, whatever its state be: gas, liquid or solid. Thus, the absolute refractive index of a medium in relation to vacuum is defined as the ratio c/v of the propagation velocity c of a monochromatic electromagnetic radiation in vacuum at its velocity v in this medium. The photonic refractometry (field of ultraviolet, visible and infrared radiations) is the set of the measure techniques of the refractive indexes having a role in chemical analysis. The refractometry measures can only be applied to media which are optically transparent. After having described these techniques, the author presents their uses in chemical analysis. (O.M.)

  12. European activities in space radiation biology and exobiology

    International Nuclear Information System (INIS)

    Horneck, G.

    1996-01-01

    In view of the space station era, the European Space Agency has initiated a review and planning document for space life sciences. Radiation biology includes dosimetry of the radiation field and its modification by mass shielding, studies on the biological responses to radiation in space, on the potential impact of space flight environment on radiation effects, and assessing the radiation risks and establishing radiation protection guidelines. To reach a better understanding of the processes leading to the origin, evolution and distribution of life, exobiological activities include the exploration of the solar system, the collection and analysis of extraterrestrial samples and the utilization of space as a tool for testing the impact of space environment on organics and resistant life forms. (author)

  13. Bugs and gas: Agreements banning chemical and biological weapons

    Science.gov (United States)

    Mikulak, Robert P.

    2017-11-01

    The use of chemical or biological weapons, whether by a State or terrorists, continues to be a serious security concern. Both types of weapons are prohibited by multilateral treaties that have very broad membership, but both the Biological Weapons Convention and the Chemical Weapons Convention are facing major challenges. In particular, the continued use of chemical weapons in the Syrian civil war by government forces risks eroding the norm against the use of such weapons. This paper briefly explore the recent history of efforts to constrain chemical and biological weapons and outlines challenges for the future.

  14. Radiation biology as a basis for multidisciplinary cancer therapy

    International Nuclear Information System (INIS)

    Hosoya, N.

    2017-01-01

    The research field of radiation biology has progressed greatly thanks to the advances in molecular biology. DNA in the cell nucleus is the principal target of radiation. The biological effect of radiation can be determined by how the DNA damage is processed in the cell. In order to prevent deleterious biological effects due to DNA damage, the cells possess a system termed 'DNA damage response'. The DNA damage response finally induces cell cycle arrest, activation of DNA repair pathways, or cell death. If accurately repaired, DNA damage will result in survival of cells with no biological effects. If inaccurately repaired, DNA damage may result in survival of cells exhibiting genetic alterations, which can lead to the development of various diseases including cancer. If unrepaired, fatal DNA damage such as the DNA double-strand break will result in cell depth. Since radiation therapy and chemotherapy are designed to specifically kill cancer cells by inducing DNA double-strand breaks, it is important to take advantage of cancer-specific abnormalities in DNA damage response. In this review, I describe the impact of targeting DNA damage response in cancer therapy and show how progress in radiation biology has contributed to the development of novel therapeutic strategies. (author)

  15. Journal of Medical Chemical, Biological and Radiological Defense

    International Nuclear Information System (INIS)

    Price, B.

    2007-01-01

    The Journal of Medical Chemical, Biological, and Radiological Defense is a free, on-line journal dedicated to providing an international, peer-reviewed journal of original scientific research and clinical and doctrinal knowledge in the area of medical treatment and countermeasures for chemical, biological and radiological defense; and to developing and maintaining an archive of current research and development information on training, doctrine, and professional discussions of problems related to chemical, biological and radiological casualties. The Journal, www.JMedCBR.org, now in its fifth year, is sponsored by the US Defense Threat Reduction Agency. Areas of interest include, but are not limited to: Neuroprotectants; Bioscavengers for Nerve Agents; Medical Diagnostic Systems and Technologies; Medical Effects of Low Level Exposures; Toxicology and Biological Effects of TICs and TIMs; Broad Spectrum Medical Countermeasures; Treatments and Therapeutics for Bacterial, Viral and Toxin Agents; Radiological Medical Countermeasures; Clinical Treatment of Chemical, Biological or Radiological Casualties; Toxins Structures and Treatments. The Journal is supported by an editorial advisory board of distinguished scientists and researchers in the fields of CBR defense and medical treatment and countermeasures in eleven countries.(author)

  16. Radiation Absorption and Use Efficiency of Common Mallow (Malva sylvestris L. Affected by Different Sources of Organic, Biological and Chemical Fertilizers and Intercropping with Fenugreek (Trigonella foenum-graecum

    Directory of Open Access Journals (Sweden)

    S. A. R Razavi

    2017-06-01

    Full Text Available Introduction Over one billion people, mostly in developing countries, use medicinal plants for the whole life or some part of it or at least prefer them to the synthetic drugs. According to a study of World Bank, trade in medicinal plants will have a share of over 5$ trillion in global trade in 2050. Growing population during last century and the demand for harvesting medicinal plants from natural areas, particularly those which commonly used, endangered these species with the risk of extinction. Common Mallow (Malva sylvestris L. is a medicinal plant commonly used as a natural remedy and other industries e.g. cosmetic industry. On the other hand, negative impacts of synthetic agricultural inputs on human health, the need for producing healthy commodities, replacing chemical agricultural inputs with some environmental friendly ones, and paying attention to new concepts like sustainability, lead agroecologists to introduce ecologically alternatives to farmers, in order to be replaced with chemical fertilizers. Using Plant growth Promoting Rhizobacteria (PGPR and fungi symbiotic with many vascular plants, is one of these alternatives. Mechanistic crop growth analysis including radiation absorption and use efficiency was compiled in agricultural researches from 1950, farther than classical analysis. Thus, the goal of this experiment is to evaluate radiation absorption and use efficiency of Common Mallow under the effect of different sources of biological, chemical and organic fertilizers and intercropping with Fenugreek (Trigonellafoenum-graecum. Materials and Methods The experiment was conducted as a split plot design based on RCBD with three replications at the research farm of Ferdowsi University of Mashhad during the growing season of 2013. The main plot factor had two levels: 1-application of cattle manure and 2-no application of cattle manure, and the sub plot factor had seven levels as: 1- Nitroxin®, 2-Sulphur solubilizing bacteria (SSB 3

  17. Biological effects of high-energy radiation

    International Nuclear Information System (INIS)

    Curtis, S.B.

    1976-01-01

    The biological effects of high-energy radiation are reviewed, with emphasis on the effects of the hadronic component. Proton and helium ion effects are similar to those of the more conventional and sparsely ionizing x- and γ-radiation. Heavy-ions are known to be more biologically effective, but the long term hazard from accumulated damage has yet to be assessed. Some evidence of widely varying but dramatically increased effectiveness of very high-energy (approximately 70 GeV) hadron beams is reviewed. Finally, the importance of the neutron component in many situations around high-energy accelerators is pointed out

  18. Advances in Physical and Biological Radiation Detectors. Proceedings of a Symposium on New Developments in Physical and Biological Radiation Detectors

    International Nuclear Information System (INIS)

    1971-01-01

    Radiation dosimetry is a fundamental part of all radiation protection work. The measurements are made with a variety of instruments, and health physicists, after professional interpretation of the data, can assess the levels of exposure which might be encountered in a given area or the individual doses received by workers, visitors and others at places where the possibility of radiation exposure exists. The types of radiation concerned here are photon radiations, ranging from soft X-rays to gamma rays, and particulate radiations such as β-rays, α-particles, protons, neutrons and fission fragments. The type of technique used depends not only on the type of radiation but also on such factors as whether the radiation is from a source internal or external to the body. Radiation dosimetry is not only used at nuclear facilities; it has diverse applications, for example in determining doses when radiation sources are employed for medical diagnostics and therapy, in safeguarding workers in any industry where isotopes are used, and in assessing the effect of both naturally occurring and man-made radiations on the general public and the environment. The advances of modern technology have increased the variety of sources; an example can be given from colour television, where the high potential necessary in certain colour cathode-ray tubes generates a non-negligible amount of X-rays. The Symposium on New Developments in Physical and Biological Radiation Detectors was one of a continuing series of meetings in which the International Atomic Energy Agency furthers the exchange of information on all aspects of personnel and area dosimetry. The Symposium was devoted in particular to a study of the dose meters themselves - their radiation-sensitive elements (both physical and biological),their instrumentation, and calibration and standardization. Several speakers suggested that the situation in the standardization and calibration of measuring equipment and sources was

  19. physical, chemical, technological and biological properties of some mutant oil seeds induced by gamma radiation

    International Nuclear Information System (INIS)

    Ali, H.G.M.

    2003-01-01

    The present study has been undertaken to evaluated sesame, sunflower and safflower seeds induced by gamma rays, as plant breeding unit, plant research department, radioisotope application division, nuclear research center, atomic energy authority Inshas. the obtained results indicate the following : chemical composition of mutant seeds: the radiation mutation caused a significant increase in both oil and ash content total carbohydrates showed a significant decreased in sesame seeds. radiation mutation induced significant increase in oil and protein content of sunflower and safflower seeds. while the total carbohydrate showed a significant decrease. physiochemical properties of oils extracted mutant seeds: the radiation mutation had no real effect on the refractive index and A.V of oils extracted from control and mutant sesame, sunflower and safflower seeds. while it caused a slight increase in red color and P.V. of sesame oil, the thiobarbituric acid (TBA) value of mutant sesame oil was not alter upon radiation mutation, but it induced a slight decrease in TBA of mutant sunflower and safflower oils. the unsaponifiable matter percentage of oils extracted from mutant sesame, sunflower and safflower seeds were slightly increased by radiation mutation .radiation mutation of seeds had no real effect on the total SFA and USFA of sesame oil. however, radiation mutation induced a remarkable changes in fatty acid profiles of sunflower and safflower oil as total SFA decreased, while USFA increased. Uric acid was only detected in oil extracted from mutant sunflower seeds

  20. Terrorist threat, chemical, biological, radiological, nuclear medical approach; Menace terroriste, approche medicale nucleaire, radiologique, biologique, chimique

    Energy Technology Data Exchange (ETDEWEB)

    Revel, Th. de [Hopital d' Instruction des Armees Percy, 92 - Clamart (France); Gourmelon, P. [Institut de Radioprotection et de Surete Nucleaire (IRSN), 92 - Clamart (France); Vidal, D. [Centre de Recherche du Service de Sante des Armees, 38 - La Tronche (France); Renaudeau, C. [Ecole du Val de Grace, 92 - Clamart (France)

    2005-07-01

    The different aspects linked to the use of nuclear, radiological, biological and or chemical weapons are gathered in this work. They concern history, fundamental aspect, diagnosis, therapy and prevention. The part devoted to the nuclear aspect concern the accidents in relation with ionizing radiations, the radiation syndrome, the contribution and limits of dosimetry, the treatment of medullary aplasia, the evaluation and treatment of an internal contamination, new perspectives on the use of cytokine for the treatment of accidental irradiated persons, alternative to the blood transfusion. (N.C.)

  1. Chemical Potential Dependence of the Dressed-Quark Propagator from an Effective Quark-Quark Interaction

    Institute of Scientific and Technical Information of China (English)

    ZONG Hong-Shi; PING Jia-Lun; SUN Wei-Min; CHANG Chao-Hsi; WANG Fan

    2002-01-01

    We exhibit a method for obtaining the low chemical potential dependence of the dressed quark propagatorfrom an effective quark-quark interaction model. Within this approach we explore the chemical potential dependenceof the dressed-quark propagator, which provides a means of determining the behavior of the chiral and deconfinementorder parameters. A comparison with the results of previous researches is given.

  2. The progress of molecular biology in radiation research

    International Nuclear Information System (INIS)

    Wei Kang

    1989-01-01

    The recent progress in application of molecular biology techniques in the study of radiation biology is reviewed. The three sections are as follows: (1) the study of DNA damage on molecular level, (2) the molecular mechanism of radiation cell genetics, including chromosome abberation and cell mutation, (3) the study on DNA repair gene with DNA mediated gene transfer techniques

  3. Natural radiation sources fabricated from potassic chemical fertilizers and application to radiation education

    International Nuclear Information System (INIS)

    Kawano, Takao

    2010-01-01

    Potassic chemical fertilizers contain potassium, a small part of which is potassium-40. Since potassium-40 is a naturally occurring radioisotope, potassic chemical fertilizers are often used for demonstrations of the existence of natural radioisotopes and radiation. To fabricate radiation sources as educational tools, the compression and formation method developed by our previous study was applied to 13 brands of commercially available chemical fertilizers containing different amounts of potassium. The suitability (size, weight, and solidness) of thus fabricated sources was examined and 12 of them were selected as easy-to-use radiation sources at radiation educational courses. The radiation strength (radiation count rate measured by a GM survey meter) and potassium content of the 12 sources were examined. It was found that the count rate was wholly proportional to the percentage of potassium, and a new educational application was proposed and discussed for understanding that the substance emitting radiation must be the potassium present in the raw fertilizers. (author)

  4. Biomaterials for mediation of chemical and biological warfare agents.

    Science.gov (United States)

    Russell, Alan J; Berberich, Jason A; Drevon, Geraldine F; Koepsel, Richard R

    2003-01-01

    Recent events have emphasized the threat from chemical and biological warfare agents. Within the efforts to counter this threat, the biocatalytic destruction and sensing of chemical and biological weapons has become an important area of focus. The specificity and high catalytic rates of biological catalysts make them appropriate for decommissioning nerve agent stockpiles, counteracting nerve agent attacks, and remediation of organophosphate spills. A number of materials have been prepared containing enzymes for the destruction of and protection against organophosphate nerve agents and biological warfare agents. This review discusses the major chemical and biological warfare agents, decontamination methods, and biomaterials that have potential for the preparation of decontamination wipes, gas filters, column packings, protective wear, and self-decontaminating paints and coatings.

  5. Prototype Biology-Based Radiation Risk Module Project

    Science.gov (United States)

    Terrier, Douglas; Clayton, Ronald G.; Patel, Zarana; Hu, Shaowen; Huff, Janice

    2015-01-01

    Biological effects of space radiation and risk mitigation are strategic knowledge gaps for the Evolvable Mars Campaign. The current epidemiology-based NASA Space Cancer Risk (NSCR) model contains large uncertainties (HAT #6.5a) due to lack of information on the radiobiology of galactic cosmic rays (GCR) and lack of human data. The use of experimental models that most accurately replicate the response of human tissues is critical for precision in risk projections. Our proposed study will compare DNA damage, histological, and cell kinetic parameters after irradiation in normal 2D human cells versus 3D tissue models, and it will use a multi-scale computational model (CHASTE) to investigate various biological processes that may contribute to carcinogenesis, including radiation-induced cellular signaling pathways. This cross-disciplinary work, with biological validation of an evolvable mathematical computational model, will help reduce uncertainties within NSCR and aid risk mitigation for radiation-induced carcinogenesis.

  6. Cellular response to ionizing radiations: a study of the roles of physics and biology

    International Nuclear Information System (INIS)

    DeWyngaert, J.K.

    1982-01-01

    A study of the complementary roles of physics and biology in determining the response of cellular systems to ionizing radiations has been conducted. Upon exposure to radiation, a cell responds in a binary (yes/no) manner in terms of its proliferative ability (survival). The relationship between the survival probability and absorbed dose may then be examined in terms of relevant physical and biological parameters. The approach to these studies was to vary the physics and biology independently and observe separately their influences upon the measured effect. Unique to these studies was the use of heterogeneous tumor systems. These are solid tumors found to consist of genetically related but identifiably distinct populations of cells. The two heterogeneous systems studied, a murine system consisting of four subpopulations and a human tumor system with two subpopulations, were exposed to graded doses of 14 MeV neutrons or x-rays and their effectiveness in inducing cell lethality compared. A further examination of the radiation effect involved a study at the chemical level, measuring the ability of oxygen to potentiate the damage produced by photon irradiation. To summarize, the physics, biology and the environment have all been varied, and the systematics of the responses studied. The data were analyzed within the formalisms of the dual theory of radiation action, the repair-misrepair model, and the repair saturation model of cell killing. The change in survival curve shape and the increased effectiveness in cell killing for higher Linear Energy Transfer (LET) radiations (neutrons vs. x-rays) are discussed in relation to explanations in terms of either physical or biochemical processes

  7. Organic Chemistry and Biology: Chemical Biology Through the Eyes of Collaboration

    Science.gov (United States)

    Hruby, Victor J.

    2011-01-01

    From a scientific perspective, efforts to understand biology including what constitutes health and disease has become a chemical problem. However, chemists and biologists “see” the problems of understanding biology from different perspectives, and this has retarded progress in solving the problems especially as they relate to health and disease. This suggests that close collaboration between chemists and biologists is not only necessary but essential for progress in both the biology and chemistry that will provide solutions to the global questions of biology. This perspective has directed my scientific efforts for the past 45 years, and in this overview I provide my perspective of how the applications of synthetic chemistry, structural design, and numerous other chemical principles have intersected in my collaborations with biologists to provide new tools, new science, and new insights that were only made possible and fruitful by these collaborations. PMID:20000552

  8. Nonlinear magnetoacoustic wave propagation with chemical reactions

    Science.gov (United States)

    Margulies, Timothy Scott

    2002-11-01

    The magnetoacoustic problem with an application to sound wave propagation through electrically conducting fluids such as the ocean in the Earth's magnetic field, liquid metals, or plasmas has been addressed taking into account several simultaneous chemical reactions. Using continuum balance equations for the total mass, linear momentum, energy; as well as Maxwell's electrodynamic equations, a nonlinear beam equation has been developed to generalize the Khokhlov-Zabolotskaya-Kuznetsov (KZK) equation for a fluid with linear viscosity but nonlinear and diffraction effects. Thermodynamic parameters are used and not tailored to only an adiabatic fluid case. The chemical kinetic equations build on a relaxing media approach presented, for example, by K. Naugolnukh and L. Ostrovsky [Nonlinear Wave Processes in Acoustics (Cambridge Univ. Press, Cambridge, 1998)] for a linearized single reaction and thermodynamic pressure equation of state. Approximations for large and small relaxation times and for magnetohydrodynamic parameters [Korsunskii, Sov. Phys. Acoust. 36 (1990)] are examined. Additionally, Cattaneo's equation for heat conduction and its generalization for a memory process rather than a Fourier's law are taken into account. It was introduced for the heat flux depends on the temperature gradient at an earlier time to generate heat pulses of finite speed.

  9. Ionizing radiation induced biological response and its public health implication

    International Nuclear Information System (INIS)

    Koeteles, Gy.

    1994-01-01

    Several sources of ionizing radiation exist in natural and artificial environment of humanity. An overview of their biological effects and the biological response of man is present. Emphasize is given to the differences caused by high and low doses. The interrelation of radiology, radiation hygiene and public health is pointed out. Especially, the physical and biological effects of radiation on cells and their responses are discussed in more detail. (R.P.)

  10. Request for Travel Funds for Systems Radiation Biology Workshop

    Energy Technology Data Exchange (ETDEWEB)

    Barcellos-Hoff, Mary Helen [NYU School of Medicine

    2014-03-22

    The 3rd International Systems Radiation Biology Workshop brought together the major European, US and Japanese research programs on radiation risk as well as selected experts representing systems biological approaches to discuss how the new methodologies could be best exploited for low dose research. A significant part of the workshop was devoted to discussions organised as breakout group sessions. To facilitate discussions number of participants was limited to 60 persons. To achieve the goals of this symposium in this international conference, support from DOE is vital. Hence, this proposal requested support in the amount of $15,000 to cover the travel expenses of international experts and radiation biology scientists from the United States. This supporting mechanism was clearly identified to the selected US participants as a conference support award from the DOE (See attached PDF). The workshop was an outstanding opportunity to strengthen interactions between leading experts in the emerging areas of radiation sciences, and will also provide opportunities for younger scientists to meet with experts and discuss their results. This workshop was designed to endorse active engagement in international collaboration. A major objective of this conference was to effectively communicate research results, in order to ensure that current thinking reflects sound science of radiation biology. Further, this international event addressed the use and success of scientific initiatives in radiation biology for policymakers, standard-setters, and the general public.

  11. Radiation-chemical destruction of cellulose and other polysaccharides

    International Nuclear Information System (INIS)

    Ershov, B.G.

    1998-01-01

    The studies concerning the radiation-chemical destruction of cellulose, its ethers and some polysaccharides (xylan, starch, decstrans, chitin, chitosan and geparin) are discussed. Ionising irradiation causes the destruction of these compounds with the decay of pyranose ring, accompanied by the formation of compounds containing carbonyl or carboxyl groups, as well as hydrogen, carbon dioxide, and carbon oxide. The efficiency of radiation degradation increases with increasing the temperature and depends on the structure of polysaccharides and the nature of substituents. The mechanism of radiation-chemical transformations of cellulose and others polysaccharides is proposed. Prospects of the application of radiation-chemical methods of treatment of cellulose and other polysaccharides in industry and agriculture considered [ru

  12. Radiation physics, biophysics, and radiation biology. Progress report, December 1, 1993--November 30, 1994

    Energy Technology Data Exchange (ETDEWEB)

    Hall, E.J.; Zaider, M.

    1994-05-01

    Research at the Center for Radiological Research is a blend of physics, chemistry and biology and epitomizes the multidisciplinary approach towards understanding the mechanisms involved in the health problems resulting from human exposure to ionizing radiations. To an increasing extent, the focus of attention is on biochemistry and the application of the techniques of molecular biology to the problems of radiation biology. Research highlights from the past year are briefly described.

  13. Radiation physics, biophysics, and radiation biology. Progress report, December 1, 1993--November 30, 1994

    International Nuclear Information System (INIS)

    Hall, E.J.; Zaider, M.

    1994-05-01

    Research at the Center for Radiological Research is a blend of physics, chemistry and biology and epitomizes the multidisciplinary approach towards understanding the mechanisms involved in the health problems resulting from human exposure to ionizing radiations. To an increasing extent, the focus of attention is on biochemistry and the application of the techniques of molecular biology to the problems of radiation biology. Research highlights from the past year are briefly described

  14. Damage pattern as a function of radiation quality and other factors.

    Science.gov (United States)

    Burkart, W; Jung, T; Frasch, G

    1999-01-01

    An understanding of damage pattern in critical cellular structures such as DNA is an important prerequisite for a mechanistic assessment of primary radiation damage, its possible repair, and the propagation of residual changes in somatic and germ cells as potential contributors to disease or ageing. Important quantitative insights have been made recently on the distribution in time and space of critical lesions from direct and indirect action of ionizing radiation on mammalian cells. When compared to damage from chemicals or from spontaneous degradation, e.g. depurination or base deamination in DNA, the potential of even low-LET radiation to create local hot spots of damage from single particle tracks is of utmost importance. This has important repercussions on inferences from critical biological effects at high dose and dose rate exposure situations to health risks at chronic, low-level exposures as experienced in environmental and controlled occupational settings. About 10,000 DNA lesions per human cell nucleus and day from spontaneous degradation and chemical attack cause no apparent effect, but a dose of 4 Gy translating into a similar number of direct and indirect DNA breaks induces acute lethality. Therefore, single lesions cannot explain the high efficiency of ionizing radiation in the induction of mutation, transformation and loss of proliferative capacity. Clustered damage leading to poorly repairable double-strand breaks or even more complex local DNA degradation, correlates better with fixed damage and critical biological endpoints. A comparison with other physical, chemical and biological agents indicates that ionizing radiation is indeed set apart from these by its unique micro- and nano-dosimetric traits. Only a few other agents such as bleomycin have a similar potential to cause complex damage from single events. However, in view of the multi-stage mechanism of carcinogenesis, it is still an open question whether dose-effect linearity for complex

  15. Current Status and Recommendations for the Future of Research, Teaching, and Testing in the Biological Sciences of Radiation Oncology: Report of the American Society for Radiation Oncology Cancer Biology/Radiation Biology Task Force, Executive Summary

    Energy Technology Data Exchange (ETDEWEB)

    Wallner, Paul E., E-mail: pwallner@theabr.org [21st Century Oncology, LLC, and the American Board of Radiology, Bethesda, Maryland (United States); Anscher, Mitchell S. [Department of Radiation Oncology, Virginia Commonwealth University, Richmond, Virginia (United States); Barker, Christopher A. [Department of Radiation Oncology, Memorial Sloan-Kettering Cancer Center, New York, New York (United States); Bassetti, Michael [Department of Human Oncology, University of Wisconsin Carbone Cancer Center, Madison, Wisconsin (United States); Bristow, Robert G. [Departments of Radiation Oncology and Medical Biophysics, Princess Margaret Cancer Center/University of Toronto, Toronto, Ontario (Canada); Cha, Yong I. [Department of Radiation Oncology, Norton Cancer Center, Louisville, Kentucky (United States); Dicker, Adam P. [Department of Radiation Oncology, Thomas Jefferson University, Philadelphia, Pennsylvania (United States); Formenti, Silvia C. [Department of Radiation Oncology, New York University, New York, New York (United States); Graves, Edward E. [Departments of Radiation Oncology and Radiology, Stanford University, Stanford, California (United States); Hahn, Stephen M. [Department of Radiation Oncology, University of Pennsylvania (United States); Hei, Tom K. [Center for Radiation Research, Columbia University, New York, New York (United States); Kimmelman, Alec C. [Department of Radiation Oncology, Dana-Farber Cancer Institute, Boston, Massachusetts (United States); Kirsch, David G. [Department of Radiation Oncology, Duke University, Durham, North Carolina (United States); Kozak, Kevin R. [Department of Human Oncology, University of Wisconsin (United States); Lawrence, Theodore S. [Department of Radiation Oncology, University of Michigan (United States); Marples, Brian [Department of Radiation Oncology, Oakland University, Oakland, California (United States); and others

    2014-01-01

    In early 2011, a dialogue was initiated within the Board of Directors (BOD) of the American Society for Radiation Oncology (ASTRO) regarding the future of the basic sciences of the specialty, primarily focused on the current state and potential future direction of basic research within radiation oncology. After consideration of the complexity of the issues involved and the precise nature of the undertaking, in August 2011, the BOD empanelled a Cancer Biology/Radiation Biology Task Force (TF). The TF was charged with developing an accurate snapshot of the current state of basic (preclinical) research in radiation oncology from the perspective of relevance to the modern clinical practice of radiation oncology as well as the education of our trainees and attending physicians in the biological sciences. The TF was further charged with making suggestions as to critical areas of biological basic research investigation that might be most likely to maintain and build further the scientific foundation and vitality of radiation oncology as an independent and vibrant medical specialty. It was not within the scope of service of the TF to consider the quality of ongoing research efforts within the broader radiation oncology space, to presume to consider their future potential, or to discourage in any way the investigators committed to areas of interest other than those targeted. The TF charge specifically precluded consideration of research issues related to technology, physics, or clinical investigations. This document represents an Executive Summary of the Task Force report.

  16. Biologic effects of electromagnetic radiation and microwave

    International Nuclear Information System (INIS)

    Deng Hua

    2002-01-01

    Electromagnetic radiation and microwave exist mankind's environment widely. People realize they disserve authors' health when authors make use of them. Electromagnetic radiation is one of the major physic factors which injure people's health. A review of the biologic mechanism about electromagnetic radiation and microwave, their harmful effects to human body, problems in authors' research and the prospect

  17. Radiations at the physics-biology interface. Utilization of radiations for research

    International Nuclear Information System (INIS)

    Douzou, P.

    1997-01-01

    Structural biology, which study the relation between the structure of biomolecules and their function, is at the interface between physics and biology. With the help of large radiation instruments such as X ray diffraction and neutron scattering, important advancements have been accomplished in the understanding of specific biological functions and led to the development of protein engineering (such as directed mutagenesis)

  18. Information on biological health effects of ionizing radiation and radionuclides: the rule of a web site

    International Nuclear Information System (INIS)

    Comte, A.; Gaillard-Lecanu, E.; Flury-Herard, A.; Ourly, F.; Hemidy, P.; Lallemand, J.

    2006-01-01

    The purpose of this project is to provide a source of information on biological and health effects of radionuclides and ionizing radiation in an easy to use format. Reported work is made up of two distinct parts: data sheets for selected radionuclides and a web file. Data sheets: Specific radiation data sheets provide an overview of the properties, the environmental behaviour, the different pathways of human exposure and the biological and health consequences of selected radionuclides. Radionuclides that have been selected are those commonly dealt with in nuclear industry (and in other areas such as medicine) and released to the environment or naturally occurring (plutonium, tritium, carbon 14). Data sheets corresponding to the different radionuclides are based on the main sources of scientific information in dosimetry, epidemiology, radiobiology and radiation protection. These data sheets are intended for radiation protection specialists and physicians. They include: main physical and chemical characteristics, main radiation protection data: dose coefficients (public, workers), dose limits sources, total released estimate (nuclear industry, atmospheric tests, main pathway of human exposure and biological behaviour, biological and health effects, medical supervision, treatment a list of the main references, appendix providing accurate information. Web file: http://www-dsv.cea.fr/doc/carmin_ext/fond.php This web file provides a source of information on biological and health effects of ionizing radiation and biological basic knowledge of radiation protection. Available for consultation via Internet, compiled information provides, in a same file, subjects as varied as biological mechanisms, ionizing radiations action, biological and health effects, risk assessment This file is mainly intended to assist in informing and training of non-specialist readership (students, teaching on radiation protection basic knowledge. This electronic document is divided in three

  19. Early mechanisms in radiation-induced biological damage

    International Nuclear Information System (INIS)

    Powers, E.L.

    1983-01-01

    An introduction to the mechanisms of radiation action in biological systems is presented. Several questions about the nature of the radiation damage process are discussed, including recognition of the oxygen effects, dose-response relationships, and the importance of the hydroxyl radical

  20. Biological effects of low doses of ionizing radiation

    International Nuclear Information System (INIS)

    Gonzalez, A.J.

    1994-01-01

    Few weeks ago, when the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) submitted to the U.N. General Assembly the UNSCEAR 1994 report, the international community had at its disposal a broad view of the biological effects of low doses of ionizing radiation. The 1994 report (272 pages) specifically addressed the epidemiological studies of radiation carcinogenesis and the adaptive responses to radiation in cells and organisms. The report was aimed to supplement the UNSCEAR 1993 report to the U.N. General Assembly- an extensive document of 928 pages-which addressed the global levels of radiation exposing the world population, as well as some issues on the effects of ionizing radiation, including: mechanisms of radiation oncogenesis due to radiation exposure, influence of the level of dose and dose rate on stochastic effects of radiation, hereditary effects of radiation effects on the developing human brain, and the late deterministic effects in children. Those two UNSCEAR reports taken together provide an impressive overview of current knowledge on the biological effects of ionizing radiation. This article summarizes the essential issues of both reports, although it cannot cover all available information. (Author)

  1. Radiation preservation of maize

    International Nuclear Information System (INIS)

    Wasito.

    1980-01-01

    Radiation preservation of maize was carried out. Radiation doses and sources, shielding materials, packaging materials, chemical radiation effects, biological radiation effects, were discussed. Experimental methods, samples and accessories were also presented. (SMN)

  2. Application of TSH bioindicator for studying the biological efficiency of radiation

    International Nuclear Information System (INIS)

    Cebulska-Wasilewska, A.; Rekas, K.; Kim, J.K.

    1999-01-01

    The effectiveness of neutrons from a californium-252 source in the induction of various abnormalities in the Tradescantia clone 4430 stamen hair cells (TSH assay) was studied. Special attention was paid to check whether any enhancement in effects caused by the process of boron neutron capture is visible in the cells enriched with boron ions. Two chemicals (borax and BSH) were applied to introduce boron-10 ions into cells. Inflorescences, normal or prepared with chemicals containing boron, were irradiated in the air with neutrons from the 252 Cf source at KOREI, Taejon, Korea. To estimate the relative biological effectiveness (RBE) of the boron under the study, Tradescantia inflorescences without chemical pretreatment were irradiated with various doses of X-rays. The ranges of radiation doses for neutrons were 0-0.1Gy and for X-rays 0-0.5 Gy. After time needed to complete the postirradiation repair tradescantia cuttings were transported to Cracow were screening of gene and lethal mutations in somatic cells of stamen hairs have been done and dose response relationships were plotted. In two independent experimental studies an alternation of dose-response curves was observed, probably due to slight changes in the postexposure plant treatment. However, it has not results in the change of the maximal RBE values, which for the induction of gene mutations were estimated as 5.6 in the pilot studies and 5.8 one year later. Inflorescences pretreated with borax and BSH responded to neutrons differently. The values of RBE have changed from 5.6 to 7.9 in the case of plants pretreated with 240 ppm of B-10 from borax, and 5.8 to 7.2 in the case of 400 ppm of B-10 from BSH. The results showed an increase, although statistically insignificant, in biological efficiency of radiation from the 252 Cf source in the samples pretreated with boron containing chemicals. (author)

  3. Chemical track effects in condensed systems and implications for biological damage

    International Nuclear Information System (INIS)

    Magee, J.L.; Chatterjee, A.

    1979-01-01

    The spatial distributions of reactive intermediates, chemical reactions, and products are involved in the chemical interests in particle tracks. Biological systems are considred to be concentrated aqueous solutions, and the reactions of biological molecules can occur at any time including prethermal period. Heavy particles lose approximately equal amounts of energy by two mechanisms which lead to the different patterns of energy deposit; that is, the resonant process with individual losses in the range of 0 - 100 eV, and the knock-on process which creates recoil electrons in spectra from 100 eV to the maximum. The survival of cultured cells after irradiation depends on certain parameters of the radiation. Such theories seem to imply that the deposit of energy in the proper location of a cell can guarantee its death, that is, there is all-or-none effect, dependent solely on the absorption of energy. The initial dissociation of water is assumed to require 17 eV. A weakness regarding heavy particle tracks is the lack of knowledge on the phenomena that occur at extremely high energy deposit, approximately 1000 eV per A. Significantly high temperature must be generated, accompanied by shock waves and bubble formation. In a radical diffusion model for cell survival, it is assumed that a particular type of the lesion of DNA may be formed by a purely chemical process which can provide a certain lethality. The chemical processes following the energy deposit by high energy particles are known at least in approximate way, including most of the phenomena in space and time. (Yamashita, S.)

  4. Chemical and biological weapons in the 'new wars'.

    Science.gov (United States)

    Ilchmann, Kai; Revill, James

    2014-09-01

    The strategic use of disease and poison in warfare has been subject to a longstanding and cross-cultural taboo that condemns the hostile exploitation of poisons and disease as the act of a pariah. In short, biological and chemical weapons are simply not fair game. The normative opprobrium is, however, not fixed, but context dependent and, as a social phenomenon, remains subject to erosion by social (or more specifically, antisocial) actors. The cross cultural understanding that fighting with poisons and disease is reprehensible, that they are taboo, is codified through a web of interconnected measures, principal amongst these are the 1925 Geneva Protocol; the Biological Weapons Convention; and the Chemical Weapons Convention. Whilst these treaties have weathered the storm of international events reasonably well, their continued health is premised on their being 'tended to' in the face of contextual changes, particularly facing changes in science and technology, as well as the changed nature and character of conflict. This article looks at the potential for normative erosion of the norm against chemical and biological weapons in the face of these contextual changes and the creeping legitimization of chemical and biological weapons.

  5. Biological indicators for the assessment of a radiation exposure

    International Nuclear Information System (INIS)

    Feinendegen, L.E.

    1980-01-01

    Measurement of the incidence of chromosomal aberrations in the peripheral lymphocytes, though a useful method of biological dosimetry, is techious, difficult to carry out, and time-consuming. It is most appropriate for an assessment of the probability of late damage of low doses up to 20 rad. The many attempts at using biochemical indicators for the absorbed dose have not had satisfactory results so far. Morphological changes especially of the peripheral blood cells and bone narrow cells are a sure sign of a radiolesion. However, there is the problem of quantitative measurement of these processes which has made it impossible so far to elaborate a useful biological dosimetry on this basis. Apart from the analysis of peripheral lymphocytes and leucocythes, there are three new approaches of potential value: 1. Analysis of up to 19 clinical and chemical parameters of the blood serum, - it gives a rough estimate of the probability of lethality of high prognostic value. 2. Observation of the peripheral reticulocyte count - a quick and rather uncomplicated method that does not require specific laboratories. 3. Measurement of the rate of incorporation of labelled iododeoxyuridine in bone narrow cells of radiation-exposed persons or in cell cultures in a medium containing serum of radiation-exposed persons; this method appears promising for the narrow dose range and also raises same questions concerning basic research into intercellular signal substances. (orig./MG) [de

  6. Neutron dosimetry in biology

    International Nuclear Information System (INIS)

    Sigurbjoernsson, B.; Smith, H.H.; Gustafsson, A.

    1965-01-01

    To study adequately the biological effects of different energy neutrons it is necessary to have high-intensity sources which are not contaminated by other radiations, the most serious of which are gamma rays. An effective dosimetry must provide an accurate measure of the absorbed dose, in biological materials, of each type of radiation at any reactor facility involved in radiobiological research. A standardized biological dosimetry, in addition to physical and chemical methods, may be desirable. The ideal data needed to achieve a fully documented dosimetry has been compiled by H. Glubrecht: (1) Energy spectrum and intensity of neutrons; (2) Angular distribution of neutrons on the whole surface of the irradiated object; (3) Additional undesired radiation accompanying the neutrons; (4) Physical state and chemical composition of the irradiated object. It is not sufficient to note only an integral dose value (e.g. in 'rad') as the biological effect depends on the above data

  7. Atoms, radiation, and radiation protection

    International Nuclear Information System (INIS)

    Turner, J.E.

    1986-01-01

    This book describes basic atomic and nuclear structure, the physical processes that result in the emission of ionizing radiations, and external and internal radiation protection criteria, standards, and practices from the standpoint of their underlying physical and biological basis. The sources and properties of ionizing radiation-charged particles, photons, and neutrons-and their interactions with matter are discussed in detail. The underlying physical principles of radiation detection and systems for radiation dosimetry are presented. Topics considered include atomic physics and radiation; atomic structure and radiation; the nucleus and nuclear radiation; interaction of heavy charged particles with matter; interaction of beta particles with matter; phenomena associated with charged-particle tracks; interaction of photons with matter; neutrons, fission and criticality; methods of radiation detection; radiation dosimetry; chemical and biological effects of radiation; radiation protection criteria and standards; external radiation protection; and internal dosimetry and radiation protection

  8. 78 FR 55326 - Determinations Regarding Use of Chemical Weapons in Syria Under the Chemical and Biological...

    Science.gov (United States)

    2013-09-10

    ... DEPARTMENT OF STATE [Public Notice 8460] Determinations Regarding Use of Chemical Weapons in Syria Under the Chemical and Biological Weapons Control and Warfare Elimination Act of 1991 AGENCY: Bureau of... Government has determined on August 2, pursuant to Section 306(a) of the Chemical and Biological Weapons...

  9. The enhanced variance propagation code for the Idaho Chemical Processing Plant

    International Nuclear Information System (INIS)

    Kern, E.A.; Zack, N.R.; Britschgi, J.J.

    1992-01-01

    The Variance Propagation (VP) Code was developed by the Los Alamos National Laboratory's Safeguard's Systems Group to provide off-line variance propagation and systems analysis for nuclear material processing facilities. The code can also be used as a tool in the design and evaluation of material accounting systems. In this regard , the VP code was enhanced to incorporate a model of the material accountability measurements used in the Idaho Chemical Processing Plant operated by the Westinghouse Idaho Nuclear Company. Inputs to the code were structured to account for the dissolves/headend process, the waste streams, process performed to determine the sensitivity of measurement and sampling errors to the overall material balance error. We determined that the material balance error is very sensitive to changes in the sampling errors. 3 refs

  10. Joining Forces: The Chemical Biology-Medicinal Chemistry Continuum.

    Science.gov (United States)

    Plowright, Alleyn T; Ottmann, Christian; Arkin, Michelle; Auberson, Yves P; Timmerman, Henk; Waldmann, Herbert

    2017-09-21

    The scientific advances being made across all disciplines are creating ever-increasing opportunities to enhance our knowledge of biological systems and how they relate to human disease. One of the central driving forces in discovering new medicines is medicinal chemistry, where the design and synthesis of novel compounds has led to multiple drugs. Chemical biology, sitting at the interface of many disciplines, has now emerged as a major contributor to the understanding of biological systems and is becoming an integral part of drug discovery. Bringing chemistry and biology much closer and blurring the boundaries between disciplines is creating new opportunities to probe and understand biology; both disciplines play key roles and need to join forces and work together effectively to synergize their impact. The power of chemical biology will then reach its full potential and drive innovation, leading to the discovery of transformative medicines to treat patients. Advances in cancer biology and drug discovery highlight this potential. Copyright © 2017 Elsevier Ltd. All rights reserved.

  11. Atmospheric propagation of high power laser radiation at different weather conditions

    OpenAIRE

    Pargmann, Carsten; Hall, Thomas; Duschek, Frank; Handke, Jürgen

    2016-01-01

    Applications based on the propagation of high power laser radiation through the atmosphere are limited in range and effect, due to weather dependent beam wandering, beam deterioration, and scattering processes. Security and defense related application examples are countermeasures against hostile projectiles and the powering of satellites and aircrafts. For an examination of the correlations between weather condition and laser beam characteristics DLR operates at Lampoldshausen a 130 m long fr...

  12. Chemical aspects of radiation damage processes: radiolysis

    International Nuclear Information System (INIS)

    Asmus, K.D.

    1975-01-01

    The formation of primary species and radiation chemical yields are discussed. In a section on chemical scavenging of primary species the author considers scavenging kinetics and competition reactions and gives a brief outline of some experimental methods. The radiation chemistry of aqueous solutions is discussed as an example for polar solvents. Cyclohexane is used as an example for non-polar solvents. The importance of excited states and energy transfer is considered. Reactions in the solid state are discussed and results on linear energy transfer and average ion pair formation for various kinds of radiation are surveyed. (B.R.H.)

  13. Radiation physics, biophysics, and radiation biology: Progress report, December 1, 1987-November 30, 1988

    International Nuclear Information System (INIS)

    Hall, E.J.; Zaider, M.; Delegianis, M.J.

    1988-07-01

    Research at the Radiological Research Laboratory is a blend of physics, chemistry, and biology, involving research at the basic level with the admixture of a small proportion of pragmatic or applied research in support of radiation protection and/or radiation therapy. At the current level of funding, approximately one quarter of the research of the Laboratory could be regarded as in support of radiotherapy, with the remainder addressing more basic issues. The new initiatives have been in two directions. First, there has been an increased emphasis on research in radiation chemistry, inasmuch as this subject which involves the study of free radicals and fast radiation chemistry processes starts to bridge the gap between physics and biology, between the initial deposition of radiant energy and its final expression in terms of biological consequences. Second, the emphasis in the biological research has moved towards studies at the molecular level, with the appointment of new members of staff with expertise in this area. Individual chapters were processed separately for the data base

  14. Notes on free radicals in the field of human and environmental protection against ionizing radiations

    International Nuclear Information System (INIS)

    Bittel, R.

    It is well known that ionizing radiations, in vitro and in vivo produce, free radicals which may be considered as mediators between physical agents and biological targets. Some aspects of this vast problem are accentuated. Ionizing radiations act either directly on the organic molecules of tissues or indirectly by creating, in the surroundings and in tissular water, inorganic free radicals which act on biochemical molecules to gives new radicals. Analysis of the free radical initiation phenomenon in vivo shows that many initiating agents exist, ionizing radiations representing only one group. The role of oxydants, especially oxydising polluants, and the part played by various enzyme systems (super-oxide dismutase, oxydases etc...) are emphasized. After propagation the chain reactions end in combinations between radicals are stopped by certain organic molecules (radical scavengers). Examples are given (free radical formation from compounds of great biological importance: puric and pyrimidic bases, nucleic acids in particular). These aspects are discussed from the viewpoint of their effects on human and environmental protection against both ionizing radiations and certain chemical pollution [fr

  15. Biological Research for Radiation Protection

    International Nuclear Information System (INIS)

    Kim, In Gyu; Kim, Kug Chan; Jung, Il Lae; Choi, Yong Ho; Kim, Jin Sik; Moon, Myung Sook; Byun, Hee Sun; Phyo, Ki Heon; Kim, Sung Keun

    2005-04-01

    The work scope of 'Biological Research for the Radiation Protection' had contained the research about ornithine decarboxylase and its controlling proteins, thioredoxin, peroxiredoxin, S-adenosymethionine decarboxylase, and glutamate decarboxylase 67KD effect on the cell death triggered ionizing radiation and H 2 O 2 (toxic agents). In this study, to elucidate the role of these proteins in the ionizing radiation (or H 2 O 2 )-induced apoptotic cell death, we utilized sensesed (or antisensed) cells, which overexpress (or down-regulate) RNAs associated with these proteins biosynthesis, and investigated the effects of these genes on the cytotoxicity caused by ionizing radiation and H 2 O 2 (or paraquat). We also investigated whether genisteine(or thiamine) may enhance the cytotoxic efficacy of tumor cells caused by ionizing radiation (may enhance the preventing effect radiation or paraquat-induced damage) because such compounds are able to potentiate the cell-killing or cell protecting effects. Based on the above result, we suggest that the express regulation of theses genes have potentially importance for sensitizing the efficiency of radiation therapy of cancer or for protecting the radiation-induced damage of normal cells

  16. DEGRO 2012. 18. annual congress of the German Radiation Oncology Society. Radiation oncology - medical physics - radiation biology. Abstracts

    International Nuclear Information System (INIS)

    Anon.

    2012-01-01

    The volume includes the abstracts of the contributions and posters of the 18th annual congress of the German Radiation Oncology Society DEGRO 2012. The lectures covered the following topics: Radiation physics, therapy planning; gastrointestinal tumors; radiation biology; stererotactic radiotherapy/breast carcinomas; quality management - life quality; head-neck-tumors/lymphomas; NSCL (non-small cell lung carcinomas); pelvic tumors; brain tumors/pediatric tumors. The poster sessions included the following topics: quality management, recurrent tumor therapy; brachytherapy; breast carcinomas and gynecological tumors; pelvis tumors; brain tumors; stereotactic radiotherapy; head-neck carcinomas; NSCL, proton therapy, supporting therapy; clinical radio-oncology, radiation biology, IGRT/IMRT.

  17. Applications of synchrotron radiation in biology and medicine

    International Nuclear Information System (INIS)

    Khole, V.

    1988-01-01

    This paper discusses the important role of synchrotron radiation in dealing with problems in various branches of biology and medicine, viz. molecular biology, molecular biophysics, biochemistry, cell biology, X-ray microscopy, molecular surgery, medical diagnostics (angiography, X-ray radiography, forensic medicine, element analysis), environmental biology, pollution control and photobiology. (author). 15 refs., 9 figs

  18. Biological evidence of low ionizing radiation doses

    International Nuclear Information System (INIS)

    Mirsch, Johanna

    2017-01-01

    Throughout life, every person is constantly exposed to different types of ionising radiation, without even noticing the exposure. The mean radiation exposure for people living in Germany amounts to approximately 4 mSv per year and encompasses the exposure from natural and man-made sources. The risks associated with exposure to low doses of radiation are still the subject of intense and highly controversial discussions, emphasizing the social relevance of studies investigating the effects of low radiation doses. In this thesis, DNA double-strand breaks (DSBs) were analyzed within three projects covering different aspects. DSBs are among the most hazardous DNA lesions induced by ionizing radiation, because this type of damage can easily lead to the loss of genetic information. Consequently, the DSB presents a high risk for the genetic integrity of the cell. In the first project, extensive results uncovered the track structure of charged particles in a biological model tissue. This provided the first biological data that could be used for comparison with data that were measured or predicted using theoretical physical dosimetry methods and mathematical simulations. Charged particles contribute significantly to the natural radiation exposure and are used increasingly in cancer radiotherapy because they are more efficient in tumor cell killing than X- or γ-rays. The difference in the biological effects of high energy charged particles compared with X- or γ-rays is largely determined by the spatial distribution of their energy deposition and the track structure inducing a three-dimensional damage pattern in living cells. This damage pattern consists of cells directly hit by the particle receiving a high dose and neighboring cells not directly hit by primary particles but exposed to far-reaching secondary electrons (δ-electrons). These cells receive a much lower dose deposition in the order of a few mGy. The radial dose distribution of single particle tracks was

  19. Some chemical influence on genetic effects of ionizing radiation and biodosimetry problems

    International Nuclear Information System (INIS)

    Mosse, I.B.

    2007-01-01

    as by weak chemical mutagens or by many other factors and can change biodosimetry results. Some drugs, stress, virus diseases and so on can change biological effects of radiation too. So, many factors which are not under control can change significantly biological effects of radiation and by this way can be responsible for serious mistakes of individual biodosimetry. It is necessary to take into account that these factors are averaged over a population. That's why biological methods can be used for population radiation dose estimation but not for personal one.

  20. PSL Chemical Biology Symposia First 2016 Edition: When Chemistry and Biology Share the Language of Discovery.

    Science.gov (United States)

    Gautier, Arnaud; Rodriguez, Raphaël

    2017-05-18

    Chemical biology, the science of understanding biological processes at the molecular level, has grown exponentially with the development of chemical strategies to manipulate and quantify biology with unprecedented precision. Recent advances presented at the Université Paris Sciences et Lettres symposium are discussed. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. Biological and Chemical Information Technologies

    DEFF Research Database (Denmark)

    Amos, Martyn; Dittrich, Peter; McCaskill, John

    2011-01-01

    Biological and chemical information technologies (bio/chem IT) have the potential to reshape the scientific and technological landscape. In this paper we briefly review the main challenges and opportunities in the field, before presenting several case studies based on ongoing FP7 research projects....

  2. Reliable discrimination of high explosive and chemical/biological artillery using acoustic UGS

    Science.gov (United States)

    Hohil, Myron E.; Desai, Sachi

    2005-10-01

    The Army is currently developing acoustic overwatch sensor systems that will provide extended range surveillance, detection, and identification for force protection and tactical security on the battlefield. A network of such sensors remotely deployed in conjunction with a central processing node (or gateway) will provide early warning and assessment of enemy threats, near real-time situational awareness to commanders, and may reduce potential hazards to the soldier. In contrast, the current detection of chemical/biological (CB) agents expelled into a battlefield environment is limited to the response of chemical sensors that must be located within close proximity to the CB agent. Since chemical sensors detect hazardous agents through contact, the sensor range to an airburst is the key-limiting factor in identifying a potential CB weapon attack. The associated sensor reporting latencies must be minimized to give sufficient preparation time to field commanders, who must assess if an attack is about to occur, has occurred, or if occurred, the type of agent that soldiers might be exposed to. The long-range propagation of acoustic blast waves from heavy artillery blasts, which are typical in a battlefield environment, introduces a feature for using acoustics and other disparate sensor technologies for the early detection and identification of CB threats. Employing disparate sensor technologies implies that warning of a potential CB attack can be provided to the solider more rapidly and from a safer distance when compared to that which conventional methods allow. This capability facilitates the necessity of classifying the types of rounds that have burst in a specified region in order to give both warning and provide identification of CB agents found in the area. In this paper, feature extraction methods based on the discrete wavelet transform (DWT) and multiresolution analysis facilitate the development of a robust classification algorithm that affords reliable

  3. Problems and solutions in the estimation of genetic risks from radiation and chemicals

    International Nuclear Information System (INIS)

    Russell, W.L.

    1980-01-01

    Extensive investigations with mice on the effects of various physical and biological factors, such as dose rate, sex and cell stage, on radiation-induced mutation have provided an evaluation of the genetics hazards of radiation in man. The mutational results obtained in both sexes with progressive lowering of the radiation dose rate have permitted estimation of the mutation frequency expected under the low-level radiation conditions of most human exposure. Supplementing the studies on mutation frequency are investigations on the phenotypic effects of mutations in mice, particularly anatomical disorders of the skeleton, which allow an estimation of the degree of human handicap associated with the occurrence of parallel defects in man. Estimation of the genetic risk from chemical mutagens is much more difficult, and the research is much less advanced. Results on transmitted mutations in mice indicate a poor correlation with mutation induction in non-mammalian organisms

  4. Biological effects of ionizing radiation

    International Nuclear Information System (INIS)

    Gisone, Pablo; Perez, Maria R.

    2001-01-01

    It has been emphasised the importance of DNA as the main target for ionizing radiation, that can induce damage by its direct action on this molecule or by an indirect effect mediated by free-radicals generated by water radiolysis. Biological effects of ionizing radiation are influenced not only by the dose but also by the dose-rate and the radiation quality. Radiation induced damage, mainly DNA single and double strand breaks, is detected by molecular sensors which in turn trigger signalling cascades leading to cell cycle arrest to allow DNA repair or programmed cell death (apoptosis). Those effects related with cell death, named deterministic, exhibits a dose-threshold below which they are not observed. Acute radiation syndrome and radiological burns are examples of this kind of effects. Other radiation induced effects, called stochastic, are the consequence of cell transformation and do not exhibit a dose-threshold. This is the case of cancer induction and hereditary effects. The aim of this presentation is briefly describe the main aspects of deterministic and stochastic effects from the point of view of radiobiology and radio pathology. (author)

  5. In Silico Nanodosimetry: New Insights into Nontargeted Biological Responses to Radiation

    Directory of Open Access Journals (Sweden)

    Zdenka Kuncic

    2012-01-01

    nontargeted responses cannot be understood in the framework of DNA-centric radiobiological models; what is needed are new physically motivated models that address the damage-sensing signalling pathways triggered by the production of reactive free radicals. To this end, we have conducted a series of in silico experiments aimed at elucidating the underlying physical processes responsible for nontargeted biological responses to radiation. Our simulation studies implement new results on very low-energy electromagnetic interactions in liquid water (applicable down to nanoscales and we also consider a realistic simulation of extranuclear microbeam irradiation of a cell. Our results support the idea that organelles with important functional roles, such as mitochondria and lysosomes, as well as membranes, are viable targets for ionizations and excitations, and their chemical composition and density are critical to determining the free radical yield and ensuing biological responses.

  6. Radiation protection standards: a summary of the biological effects of ionising radiation and principles of radiation protection

    International Nuclear Information System (INIS)

    1994-01-01

    This leaflet in the NRPB At-a-Glance-Series briefly summarises the biological effects of radiation, harm and sensitivity to radiation, radiation protection principles, acceptability of risk and the control of doses to workers, the public and in medical procedures in the UK. (UK)

  7. Cooperative biological effects between ionizing radiation and other physical and chemical agents.

    Science.gov (United States)

    Manti, Lorenzo; D'Arco, Annalisa

    2010-01-01

    Exposure to ionizing radiation (IR), at environmentally and therapeutically relevant doses or as a result of diagnostics or accidents, causes cyto- and genotoxic damage. However, exposure to IR alone is a rare event as it occurs in spatial and temporal combination with several physico-chemical agents. Some of these are of known noxiousness, as is the case with chemical compounds at high dose, hence additive/synergistic effects can be expected or have been demonstrated. Conversely, the cellular toxicity of other agents, such as non-ionizing electromagnetic fields (EMFs), is only presumed and their short- and long-term cooperation on IR-induced damage remains undetermined. In this review, we shall examine evidence in support of the interplay between spatially and/or temporally related environmentally relevant stressors. In vitro or animal-based studies as well as epidemiological surveys have generally examined the combined action of no more than a couple of known or potentially DNA-damaging agents. Moreover, most existing research mainly focused on short-term effects of combined exposures. Hence, it is important that quantitative research addresses the issue of the possible cooperation between chronic exposure to environmental trace contaminants and exposure to EMFs, examining not only the modulation of damage acutely induced by IR but also long-term genome stability. 2010 Elsevier B.V. All rights reserved.

  8. Current research in Canada on biological effects of ionizing radiation

    International Nuclear Information System (INIS)

    Marko, A.M.

    1980-05-01

    A survey of current research in Canada on the biological effects of ionizing radiation has been compiled. The list of projects has been classified according to structure (organizational state of the test system) as well as according to the type of effects. Using several assumptions, ballpark estimates of expenditures on these activities have been made. Agencies funding these research activities have been tabulated and the break-down of research in government laboratories and in academic institutions has been designated. Wherever possible, comparisons have been made outlining differences or similarities that exist between the United States and Canada concerning biological radiation research. It has been concluded that relevant research in this area in Canada is inadequate. Wherever possible, strengths and weaknesses in radiation biology programs have been indicated. The most promising course for Canada to follow is to support adequately fundamental studies of the biological effects of radiation. (auth)

  9. Biological consequences of radiation: risk factors

    International Nuclear Information System (INIS)

    1985-01-01

    This publication is a syllabus of a course on Radiation Protection. The publication offers an overview of the biological radiation effects at cellular level. For that purpose, different forms of cancers and their incidence are first discussed; structure and functioning of normal cells are considered and an introduction in genetics is given. Finally, an overview is presented of the character of tissue damage after high-dose irradiation. (G.J.P.)

  10. Scientific projection paper for radiation chemistry

    International Nuclear Information System (INIS)

    Simic, M.G.

    1980-01-01

    Together with radiation physics, an understanding of radiation chemistry is necessary for full appreciation of biological effects of high and low energy radiations, and for the development of prophylactic, therapeutic and potentiating methods and techniques in biological organisms. Areas covered in some detail in this report include: the early chemical events involved in the deposition of radiation energy; the kinetics of free radical and excited state reactions; the application of radiation chemistry to radiation biology; and the availability of instrumentation

  11. The nuclear terrorist, radiological, biological, chemical threat. Medical approach

    International Nuclear Information System (INIS)

    Gourmelon, P.; Vidal, D.; Renaudeau, C.

    2005-01-01

    This book illustrates the cooperation of the civil and the military experts in the domain of the NBRC (nuclear, biological, radiological and chemical threat). The different aspects bond to the use of nuclear, biological and chemical weapons, are discussed. Al topics of each domains (NRBC) are presented: historical and fundamental aspects, diagnostic, therapeutic and prevention. (A.L.B.)

  12. Chemical, Biological, Radiological, Nuclear, and High-Yield Explosives Consequences Management

    Science.gov (United States)

    2006-10-02

    protective measures associated with such offensive operations. Since riot control agents and herbicides are not considered to be chemical warfare agents...control. Procedures to avoid, reduce, remove, or render harmless (temporarily or permanently) nuclear, radiological, biological, and chemical...destroying, neutralizing, making harmless , or removing chemical or biological agents, or by removing radioactive material clinging to or around it. (JP 1

  13. Carbon nanostructure-based field-effect transistors for label-free chemical/biological sensors.

    Science.gov (United States)

    Hu, PingAn; Zhang, Jia; Li, Le; Wang, Zhenlong; O'Neill, William; Estrela, Pedro

    2010-01-01

    Over the past decade, electrical detection of chemical and biological species using novel nanostructure-based devices has attracted significant attention for chemical, genomics, biomedical diagnostics, and drug discovery applications. The use of nanostructured devices in chemical/biological sensors in place of conventional sensing technologies has advantages of high sensitivity, low decreased energy consumption and potentially highly miniaturized integration. Owing to their particular structure, excellent electrical properties and high chemical stability, carbon nanotube and graphene based electrical devices have been widely developed for high performance label-free chemical/biological sensors. Here, we review the latest developments of carbon nanostructure-based transistor sensors in ultrasensitive detection of chemical/biological entities, such as poisonous gases, nucleic acids, proteins and cells.

  14. Enhanced formulations for neutralization of chemical, biological and industrial toxants

    Science.gov (United States)

    Tucker, Mark D [Albuqueque, NM

    2008-06-24

    An enhanced formulation and method of making that neutralizes the adverse health effects of both chemical and biological compounds, especially chemical warfare (CW) and biological warfare (BW) agents, and toxic industrial chemicals. The enhanced formulation according to the present invention is non-toxic and non-corrosive and can be delivered by a variety of means and in different phases. The formulation provides solubilizing compounds that serve to effectively render the chemical and biological compounds, particularly CW and BW compounds, susceptible to attack, and at least one reactive compound that serves to attack (and detoxify or kill) the compound. The formulation includes at least one solubilizing agent, a reactive compound, a bleaching activator and water.

  15. Deciphering the language between biological and synthetic materials

    Directory of Open Access Journals (Sweden)

    Paolo A. Netti

    2014-06-01

    Full Text Available Chemical signals propagating through aqueous environment are at the basis of the language utilized by living systems to exchange information. In the last years, molecular biology has partly disclosed the grammar and the syntax of this complex language revealing the fascinating world of molecular communication that is the foundation of biological development.

  16. Radiation-chemical hardening of phenol-formaldehyde oligomers

    International Nuclear Information System (INIS)

    Shlapatskaya, V.V.; Omel'chenko, S.I.

    1978-01-01

    Radiation-chemical hardening of phenol formaldehyde oligomers of the resol type has been studied in the presence of furfural and diallylphthalate diluents. The samples have been hardened on an electron accelerator at an electron energy of 1.0-1.1 MeV and a dose rate of 2-3 Mrad/s. The kinetics of hardening has been studied on the yield of gel fraction within the range of absorbed doses from 7 to 400 Mrad. Radiation-chemical hardening of the studied compositions is activated with sensitizers, namely, amines, metal chlorides, and heterocyclic derivatives of metals. Furfural and diallylphthalate compositions are suitable for forming glass-fibre plastic items by the wet method and coatings under the action of ionizing radiations

  17. Biological physics and synchrotron radiation

    International Nuclear Information System (INIS)

    Filhol, J.M.; Chavanne, J.; Weckert, E.

    2001-01-01

    This conference deals with the applications of synchrotron radiation to current problems in biology and medicine. Seven sessions take stock on the subject: sources and detectors; inelastic scattering and dynamics; muscle diffraction; reaction mechanisms; macromolecular assemblies; medical applications; imaging and spectroscopy. The document presents the papers abstracts. (A.L.B.)

  18. Biological physics and synchrotron radiation

    Energy Technology Data Exchange (ETDEWEB)

    Filhol, J M; Chavanne, J [European Synchrotron Radiation Facility, 38 - Grenoble (France); Weckert, E [Hasylab at Desy, Hamburg (Germany); and others

    2001-07-01

    This conference deals with the applications of synchrotron radiation to current problems in biology and medicine. Seven sessions take stock on the subject: sources and detectors; inelastic scattering and dynamics; muscle diffraction; reaction mechanisms; macromolecular assemblies; medical applications; imaging and spectroscopy. The document presents the papers abstracts. (A.L.B.)

  19. Role of cytogenetic techniques in biological dosimetry of absorbed radiation

    International Nuclear Information System (INIS)

    Rao, B.S.

    2016-01-01

    In most of the radiation accidents, physical dosimetric information is rarely available. Further, most of the accidental exposures are non-uniform involving either partial body or localized exposure to significant doses. In such situations, physical dosimetry does not provide reliable dose estimate. It has now been realized that biological dosimetric techniques can play an important role in the assessment of absorbed dose. In recent years, a number of biological indicators of radiation have been identified. These include the kinetics of onset and persistence of prodromal syndromes (radiation sickness), cytogenetic changes in peripheral blood lymphocytes, hematological changes, biochemical indicators, ESR spectroscopy of biological samples, induction of gene mutations in red blood cells, cytogenetic and physiological changes in skin and neurophysiological changes. In general, dosimetric information is derived by a combination of several different methods, as they have potential to serve as prognostic indicators. The role of cytogenetic techniques in peripheral blood lymphocytes (PBL) as biological indicators of absorbed radiation is reviewed here

  20. Radiation damage and repair in cells and cell components. Part 2. Physical radiations and biological significance. Final report

    International Nuclear Information System (INIS)

    Fluke, D.J.

    1984-08-01

    The report comprises a teaching text, encompassing all physical radiations likely to be of biological interest, and the relevant biological effects and their significance. Topics include human radiobiology, delayed effects, radiation absorption in organisms, aqueous radiation chemistry, cell radiobiology, mutagenesis, and photobiology

  1. 2006 Chemical Biological Individual Protection (CBIP) Conference and Exhibition

    Science.gov (United States)

    2006-03-09

    Requirements Office (JRO), MAJ W. Scott Smedley , Joint Requirements Office for Chemical, Biological, Radiological, and Nuclear Defense JPEO...Decker Director of Engineering 410-436-5600 www.ecbc.army.mil Gabe Patricio, JPEO 703 681-0808 Robert Wattenbarger, JPMOIP 703 432-3198 Canadian CBRN...UNCLASSIFIED Joint Requirements Office for Chemical, Biological, and Nuclear Defense MAJ W. Scott Smedley 8 March 2006 Individual Protection Conference

  2. Ionizing radiation for sterilization of medical products and biological tissues

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, S K; Raghevendrarao, M K [Bhabha Atomic Research Centre, Bombay (India). Library and Technical Information Section

    1975-10-01

    The article reviews the deliberations of the International Symposium on Ionizing Radiation for Sterilization of Medical Products and Biological Tissues which was held during 9-13 December 1974 under the auspices of the IAEA at the Bhabha Atomic Research Centre, Bombay. 42 papers were presented in the following broad subject areas: (1) Microbiological Control aspects of radiation sterilization, (2) Dosimetry aspects of radiation sterilization practices, (3) Effects of sterilizing radiation dose on the constituents of medical products, (4) Application of radiation sterilization of medical products of biological origin, (5) Technological aspects of radiation sterilization facilities, (6) Radiation sterilization of pharmaceutical substances, (7) Reports on current status of radiation sterilization of medical products in IAEA member states and (8) Working group discussion on the revision of the IAEA recommended code of practice for radiation sterilization of medical products.

  3. Two modes of wave propagation manifested in vertical electric dipole radiation over a sphere

    International Nuclear Information System (INIS)

    Houdzoumis, Vassilios A.

    2000-01-01

    The radiation of a vertical electric dipole over an electrically homogeneous sphere is considered anew, starting with a novel mathematical formulation. Both the dipole and the point of observation are assumed to lie on the spherical interface. The analysis is valid for a sphere whose radius is much larger than the wavelength in the outside region. Contributions to the value of the fields come, on the one hand, from the waves that propagate along the interface and, on the other hand, from the waves that propagate through the sphere by successive reflections. (c) 2000 American Geophysical Union

  4. Radiation-chemical aspects of solid state hot atom chemistry

    International Nuclear Information System (INIS)

    Matsuura, T.; Collins, K.E.; Collins, C.H.

    1984-01-01

    The study of nuclear hot atom chemical (NHAC) processes occurring in solids is seriously limited by the lack of adequate methods for directly studying the chemical species containing hot atoms. In the present review the effects of ionizing radiation on parent and non-parent yields from solid state targets is surveyed and qualitative interpretations are given. After a few general remarks of the relationship of radiation chemistry to solid state NHAC, a detailed description of the radiation effects is given (radiation annealing, neutron activation, changes in separable yield). (Auth.)

  5. Biological effects of low-dose ionizing radiation exposure; Biologische Wirkungen niedriger Dosen ionisierender Strahlung

    Energy Technology Data Exchange (ETDEWEB)

    Reinoehl-Kompa, Sabine; Baldauf, Daniela; Heller, Horst (comps.)

    2009-07-01

    The report on the meeting of the Strahlenschutzkommission 2007 concerning biological effects of low-dose ionizing radiation exposure includes the following contributions: Adaptive response. The importance of DNA damage mechanisms for the biological efficiency of low-energy photons. Radiation effects in mammography: the relative biological radiation effects of low-energy photons. Radiation-induced cataracts. Carcinomas following prenatal radiation exposure. Intercellular apoptosis induction and low-dose irradiation: possible consequences for the oncogenesis control. Mechanistic models for the carcinogenesis with radiation-induced cell inactivation: application to all solid tumors in the Japanese atomic bomb survivors. Microarrays at low radiation doses. Mouse models for the analysis of biological effects of low-dose ionizing radiation. The bystander effect: observations, mechanisms and implications. Lung carcinoma risk of Majak workers - modeling of carcinogenesis and the bystander effect. Microbeam studies in radiation biology - an overview. Carcinogenesis models with radiation-induced genomic instability. Application to two epidemiological cohorts.

  6. Radiation physics, biophysics, and radiation biology. Progress report, December 1, 1992--November 30, 1993

    Energy Technology Data Exchange (ETDEWEB)

    Hall, E.J.; Zaider, M.

    1993-05-01

    Research at the Center for Radiological Research is a multidisciplenary blend of physics, chemistry and biology aimed at understanding the mechanisms involved in the health problems resulting from human exposure to ionizing radiations. The focus is increased on biochemistry and the application of the techniques of molecular biology to the problems of radiation biology. Research highlights of the program from the past year are described. A mathematical model describing the production of single-strand and double-strand breaks in DNA as a function radiation quality has been completed. For the first time Monte Carlo techniques have been used to obtain directly the spatial distribution of DNA moieties altered by radiation. This information was obtained by including the transport codes a realistic description of the electronic structure of DNA. We have investigated structure activity relationships for the potential oncogenicity of a new generation of bioreductive drugs that function as hypoxic cytotoxins. Experimental and theoretical investigation of the inverse dose rate effect, whereby medium LET radiations actually produce an c effect when the dose is protracted, is now at a point where the basic mechanisms are reasonably understood and the complex interplay between dose, dose rate and radiation quality which is necessary for the effect to be present can now be predicted at least in vitro. In terms of early radiobiological damage, a quantitative link has been established between basic energy deposition and locally multiply damaged sites, the radiochemical precursor of DNA double strand breaks; specifically, the spatial and energy deposition requirements necessary to form LMDs have been evaluated. For the first time, a mechanically understood ``biological fingerprint`` of high-LET radiation has been established. Specifically measurement of the ratio of inter-to intra-chromosomal aberrations produces a unique signature from alpha-particles or neutrons.

  7. Biology relevant to space radiation

    International Nuclear Information System (INIS)

    Fry, R.J.M.

    1997-01-01

    There are only very limited data on the health effects to humans from the two major components of the radiations in space, namely protons and heavy ions. As a result, predictions of the accompanying effects must be based either on (1) data generated through studies of experimental systems exposed on earth at rates and fluences higher than those in space, or (2) extrapolations from studies of gamma and x rays. Better information is needed about the doses, dose rates, and the energy and LET spectra of the radiations at the organ level that are anticipated to be encountered during extended space missions. In particular, there is a need for better estimates of the relationship between radiation quality and biological effects. In the case of deterministic effects, it is the threshold that is important. The possibility of the occurrence of a large solar particle event (SPE) requires that such effects be considered during extended space missions. Analyses suggest, however, that it is feasible to provide sufficient shielding so as to reduce such effects to acceptable levels, particularly if the dose rates can be limited. If these analyses prove correct, the primary biological risks will be the stochastic effects (latent cancer induction). The contribution of one large SPE to the risk of stochastic effects while undesirable will not be large in comparison to the potential total dose on a mission of long duration

  8. Biological effects of high LET radiations

    Energy Technology Data Exchange (ETDEWEB)

    Watanabe, Masami [Nagasaki Univ. (Japan). Faculty of Pharmaceutical Sciences

    1997-03-01

    Biological effect of radiation is different by a kind of it greatly. Heavy ions were generally more effective in cell inactivation, chromosome aberration induction, mutation induction and neoplastic cell transformation induction than {gamma}-rays in SHE cells. (author)

  9. Ultrafast electron microscopy in materials science, biology, and chemistry

    International Nuclear Information System (INIS)

    King, Wayne E.; Campbell, Geoffrey H.; Frank, Alan; Reed, Bryan; Schmerge, John F.; Siwick, Bradley J.; Stuart, Brent C.; Weber, Peter M.

    2005-01-01

    The use of pump-probe experiments to study complex transient events has been an area of significant interest in materials science, biology, and chemistry. While the emphasis has been on laser pump with laser probe and laser pump with x-ray probe experiments, there is a significant and growing interest in using electrons as probes. Early experiments used electrons for gas-phase diffraction of photostimulated chemical reactions. More recently, scientists are beginning to explore phenomena in the solid state such as phase transformations, twinning, solid-state chemical reactions, radiation damage, and shock propagation. This review focuses on the emerging area of ultrafast electron microscopy (UEM), which comprises ultrafast electron diffraction (UED) and dynamic transmission electron microscopy (DTEM). The topics that are treated include the following: (1) The physics of electrons as an ultrafast probe. This encompasses the propagation dynamics of the electrons (space-charge effect, Child's law, Boersch effect) and extends to relativistic effects. (2) The anatomy of UED and DTEM instruments. This includes discussions of the photoactivated electron gun (also known as photogun or photoelectron gun) at conventional energies (60-200 keV) and extends to MeV beams generated by rf guns. Another critical aspect of the systems is the electron detector. Charge-coupled device cameras and microchannel-plate-based cameras are compared and contrasted. The effect of various physical phenomena on detective quantum efficiency is discussed. (3) Practical aspects of operation. This includes determination of time zero, measurement of pulse-length, and strategies for pulse compression. (4) Current and potential applications in materials science, biology, and chemistry. UEM has the potential to make a significant impact in future science and technology. Understanding of reaction pathways of complex transient phenomena in materials science, biology, and chemistry will provide fundamental

  10. [Biological effects of non-ionizing electromagnetic radiation].

    Science.gov (United States)

    Fedorowski, A; Steciwko, A

    1998-01-01

    Since the mid 1970's, when Adey discovered that extremely-low-frequency electromagnetic field (ELF EMF) may affect the calcium ions efflux from various cells, bioeffects of non-ionizing radiation (NIR) have become the subject of growing interest and numerous research projects. At present, the fact that NIR exerts both stimulatory and inhibitory effects on different physiological cellular parameters is rather unquestionable. At the same time, some epidemiological studies suggest that exposure to EMF is potentially harmful even if its intensity is very low. It has been proved that thermal factors are not responsible for these effects, therefore nowadays, they are called 'non-thermal effects'. Our paper deals with three different aspects of biological effects of non-ionizing radiation, bioelectromagnetism, electromagnetobiology and electromagnetic bioinformation. Firstly, we describe how EMF and photons can be produced within a living cell, how biological cycles are controlled, and what are the features of endogenous electromagnetic radiation. Secondly, we discuss various facets of external EMF interactions with living matter, focusing on extremely-low-frequencies, radio- and microwaves. Possible mechanisms of these interactions are also mentioned. Finally, we present a short overview of current theories which explain how electromagnetic couplings may control an open and dissipative structure, namely the living organism. The theory of electromagnetic bioinformation seems to explain how different physiological processes are triggered and controlled, as well as how long-range interactions may possibly occur within the complex biological system. The review points out that the presented research data must be assessed very carefully since its evaluation is crucial to set the proper limits of EMF exposure, both occupational and environmental. The study of biological effects of non-ioinizing radiation may also contribute to the development of new diagnostic and therapeutic

  11. Application study of nuclear technologies for integration chemical, biological and radiological technology

    Energy Technology Data Exchange (ETDEWEB)

    Shin, Jae Kon; Han, M. H.; Kim, Y. H.; Yang, J. E.; Jung, K. S.; Cha, H. K.; Moon, J.; La, K. H

    2001-02-01

    The projects are suggested the method to maximize the technology and research results which are being carried out by KAERI on the nuclear field. The study presents 1)the technology to rapidly and accurately determine and the nature of contamination, 2) the technology to predict the spread of contaminant and the magnitude of damage, and 3) the expert-aided decision making technology to identify the optimum counter-measures. And the solutions are also suggested the application to military technology in Chemical, Biological and Radiation field. In addition, I hope this kind of cooperation model come to be the good case of military civilian research harmony to improve the national competition capability.

  12. ChemProt: A disease chemical biology database

    DEFF Research Database (Denmark)

    Taboureau, Olivier; Oprea, Tudor I.

    2013-01-01

    The integration of chemistry, biology, and informatics to study drug actions across multiple biological targets, pathways, and biological systems is an emerging paradigm in drug discovery. Rather than reducing a complex system to simplistic models, fields such as chemogenomics and translational...... informatics are seeking to build a holistic model for a better understanding of the drug pharmacology and clinical effects. Here we will present a webserver called ChemProt that can assist, in silico, the drug actions in the context of cellular and disease networks and contribute in the field of disease...... chemical biology, drug repurposing, and off-target effects prediction....

  13. Biological, chemical and medical physics

    International Nuclear Information System (INIS)

    1990-01-01

    This is an overview of the actual situation in Brazil, concerning three important areas of physics: biological, chemical and medical. It gives a brief historical of research in these areas. It talks as well, about perspectives and financing. It contains many tables with the main research groups in activity in Brazilian institutions. (A.C.A.S.)

  14. Chemical biology of Glycosylphosphatidylinositol (GPI) anchors

    Indian Academy of Sciences (India)

    Admin

    CSIR-IIIM. Chemical biology of. Glycosylphosphatidylinositol (GPI) anchors. Ram Vishwakarma. CSIR-Indian Institute of Integrative Medicine, Jammu. N ti l I tit t f I l. N. D lhi. National Institute of Immunology, New Delhi. Piramal Life Sciences Ltd, Mumbai ...

  15. Advances in the biological effects of terahertz wave radiation.

    Science.gov (United States)

    Zhao, Li; Hao, Yan-Hui; Peng, Rui-Yun

    2014-01-01

    The terahertz (THz) band lies between microwave and infrared rays in wavelength and consists of non-ionizing radiation. Both domestic and foreign research institutions, including the army, have attached considerable importance to the research and development of THz technology because this radiation exhibits both photon-like and electron-like properties, which grant it considerable application value and potential. With the rapid development of THz technology and related applications, studies of the biological effects of THz radiation have become a major focus in the field of life sciences. Research in this field has only just begun, both at home and abroad. In this paper, research progress with respect to THz radiation, including its biological effects, mechanisms and methods of protection, will be reviewed.

  16. Statistical trend of radiation chemical studies

    International Nuclear Information System (INIS)

    Yoshida, Hiroshi

    1980-01-01

    In the field of radiation chemistry, over 1,000 reports are published year after year. Attempt has been made to review the trends in this field for more than five years, by looking through the lists of papers statistically. As for the period from 1974 to 1978, Annual Cumulation with Keyword and Author Indexes in the Biweekly List of Papers on Radiation Chemistry was referred to. For 1979, because of the unavailability of the Cumulation, Chemical Abstracts Search by Japan Information Center of Science and Technology was referred to. The contents are as follows: how far radiation chemistry is studied, what the trends of radiation chemistry is in recent years, who contributes to the advance of radiation chemistry, and where, the trend radiation chemistry takes in 1979. (J.P.N.)

  17. Chemical and biological weapons: new questions, new answers.

    Science.gov (United States)

    Hood, E

    1999-01-01

    The words "chemical and biological weapons" (CBW) send a shiver down most spines these days. With the end of the Cold War, the possibility of a massive nuclear confrontation appears remote, so today many popular doomsday scenarios center on the aggressive use of chemical or biological warfare by rogue nations or terrorist groups. As exaggerated as some of the accounts are, with CBW cast as the latest unseen, unstoppable enemy, the threat posed by these weapons is all too real, and growing. Images p931-a PMID:10585899

  18. Biological effects of nuclear radiation

    International Nuclear Information System (INIS)

    Hotz, G.

    1975-01-01

    After a brief survey about the main radiobiological effects caused by ionizing radiation, human symptoms after irradiation and incorporation are shown. The special radiotoxic effect of radionuclides which are chemically associated with metabolism-specific elements such as calcium and potassium is shown and methods of treatment are indicated. (ORU) [de

  19. Role of free radicals in radiation chemical aging

    Energy Technology Data Exchange (ETDEWEB)

    Greenstock, C L

    1986-01-01

    Ionizing radiation initiates chemical changes in DNA, phospholipid membranes and other critical cell targets, that, if allowed to accumulate unrepaired, may lead to aging and other chronic effects. The chemical effects are free radical mediated, the principal damaging species being radical OH and to a lesser extent O2-anion radical and the molecular product H/sub 2/O/sub 2/. Many compounds can act in combination with ionizing radiation, to amplify the potential oxidative stress. Chemicals, ultra-violet light, lipid peroxides and their breakdown products may increase the extent of acute and chronic radiobiological effects.

  20. Application of surface plasmons to biological and chemical sensors

    International Nuclear Information System (INIS)

    Kajikawa, Kotaro

    2015-01-01

    Surface plasmons (SPs) are a collective normal mode of electrons localized at a metallic surface. It has been used for biological sensors since 1990s. This is because it has the following specific characters: (a) The resonance condition is sensitive to the surrounding dielectric constants (refractive indexes) and (b) Highly enhanced optical-electric-fields are produced adjacent to SPs. A brief introduction is given on the principle of the biological and chemical sensors based on SPs for the readers working in the fields other than SPs, followed by a review on the recent developments of the biological and chemical sensors. (author)

  1. A proposed chemical mechanism for biological phosphate removal ...

    African Journals Online (AJOL)

    This paper presents an alternative for the ";all biological"; phosphate removal model. It is postulated that a chemical substance in wastewater reacts with orthophosphate under anaerobic conditions to make the so-called luxury uptake of phosphorus possible in biological nutrient removal (BNR) activated sludge plants.

  2. Breast cancer biology for the radiation oncologist

    Energy Technology Data Exchange (ETDEWEB)

    Strauss, Jonathan [Northwestern Univ., Chicago, IL (United States). Dept. of Radiation Oncology; Small, William [Loyola Univ. Chicago, Maywood, IL (United States). Stritch School of Medicine, Cardianl Bernardin Cancer Center; Woloschak, Gayle E. (ed.) [Northwestern Univ. Feinberg, Chicago, IL (United States). School of Medicine

    2015-10-01

    This is the first textbook of its kind devoted to describing the biological complexities of breast cancer in a way that is relevant to the radiation oncologist. Radiation Oncology has long treated breast cancer as a single biological entity, with all treatment decisions being based on clinical and pathologic risk factors. We are now beginning to understand that biological subtypes of breast cancer may have different risks of recurrence as well as different intrinsic sensitivity to radiotherapy. Multi-gene arrays that have for years been used to predict the risk of distant recurrence and the value of systemic chemotherapy may also have utility in predicting the risk of local recurrence. Additionally, the targeted agents used to treat breast cancer may interact with radiotherapy in ways that can be beneficial or undesirable. All of these emerging issues are extensively discussed in this book, and practical evidence-based treatment recommendations are presented whenever possible.

  3. Breast cancer biology for the radiation oncologist

    International Nuclear Information System (INIS)

    Strauss, Jonathan; Small, William; Woloschak, Gayle E.

    2015-01-01

    This is the first textbook of its kind devoted to describing the biological complexities of breast cancer in a way that is relevant to the radiation oncologist. Radiation Oncology has long treated breast cancer as a single biological entity, with all treatment decisions being based on clinical and pathologic risk factors. We are now beginning to understand that biological subtypes of breast cancer may have different risks of recurrence as well as different intrinsic sensitivity to radiotherapy. Multi-gene arrays that have for years been used to predict the risk of distant recurrence and the value of systemic chemotherapy may also have utility in predicting the risk of local recurrence. Additionally, the targeted agents used to treat breast cancer may interact with radiotherapy in ways that can be beneficial or undesirable. All of these emerging issues are extensively discussed in this book, and practical evidence-based treatment recommendations are presented whenever possible.

  4. Biological Art of Producing Useful Chemicals

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 21; Issue 3. Metabolic Engineering: Biological Art of Producing Useful Chemicals. Ram Kulkarni. General Article Volume 21 Issue 3 March 2016 pp 233-237. Fulltext. Click here to view fulltext PDF. Permanent link:

  5. Detection and treatment of chemical weapons and/or biological pathogens

    Science.gov (United States)

    Mariella Jr., Raymond P.

    2004-09-07

    A system for detection and treatment of chemical weapons and/or biological pathogens uses a detector system, an electrostatic precipitator or scrubber, a circulation system, and a control. The precipitator or scrubber is activated in response to a signal from the detector upon the detection of chemical weapons and/or biological pathogens.

  6. Oxygen effect in radiation biology: caffeine and serendipity

    International Nuclear Information System (INIS)

    Kesavan, P.C.

    2005-01-01

    The 'hit theory' developed in 1920s to explain the actions of ionizing radiation on cells and organisms was purely physical, and its limitation was its inadequacy to address the contemporary findings such as the oxygen enhancement of radiobiological damage, and the increased radio- sensitivity of dividing compared to non-dividing cells. The textbooks written prior to 1970s did not either refer at all to oxygen as a radiosensitizer, or had mentioned it only in a passing manner; yet 'oxygen effect' was emerging as the central dogma in radiation biology. The oxygen effect in radiation biology is highly interdisciplinary encompassing atomic physics (i.e. interaction of photon with matter), radiation chemistry (formation of reactive oxygen species), molecular signalling, gene expression and genetic alterations in cells (mutation, cancer) or the cell death (apoptosis, necrosis, mitotic catastrophe, etc.). Cell death in higher organisms is now recognized as the precursor of possible error-free cell replacement repair. (author)

  7. Modeling of the propagation of low-frequency electromagnetic radiation in the Earth’s magnetosphere

    International Nuclear Information System (INIS)

    Lebedev, N. V.; Rudenko, V. V.

    2015-01-01

    A numerical algorithm for solving the set of differential equations describing the propagation of low-frequency electromagnetic radiation in the magnetospheric plasma, including in the presence of geomagnetic waveguides in the form of large-scale plasma density inhomogeneities stretched along the Earth’s magnetic field, has been developed. Calculations of three-dimensional ray trajectories in the magnetosphere and geomagnetic waveguide with allowance for radiation polarization have revealed characteristic tendencies in the behavior of electromagnetic parameters along the ray trajectory. The results of calculations can be used for magnetospheric plasma diagnostics

  8. Treatment of Radiation Induced Biological Changes by Bone Marrow Transplantation

    International Nuclear Information System (INIS)

    El-Missiry, M.A.; Shehata, G.; Roushdy, H.M; Fayed, Th.A.

    1999-01-01

    Preventing the propagation of radiation induced oxidative damage has been a subject of considerable investigations. The ultimate goal of the present study is to use bone marrow cells to ameliorate or to treat the radiation sickness. Transplantation of bone marrow cell has shown promising results in the present experimental radiation treatment. In this report, suspension of bone marrow cells was injected into rats 12 h. after exposure to 4.5 Gy whole body gamma irradiation. Significant results were recorded on the successful control of the radiation induced disorders in a number of biochemical parameters including certain enzymatic and nonenzymatic antioxidants (superoxide dismutase and glutathione) and certain parameters related to kidney function including creatinine, urea as well as Atpase Activity in blood serum, urine and kidney tissue

  9. Low-level radiation: biological interactions, risks, and benefits. A bibliography

    International Nuclear Information System (INIS)

    1978-09-01

    The bibliography contains 3294 references that were selected from the Department of Energy's data base (EDB). The subjects covered are lower-level radiation effects on man, environmental radiation, and other biological interactions of radiation that appear to be applicable to the low-level radiation problem

  10. Chemical and biological nonproliferation program. FY99 annual report

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-03-01

    This document is the first of what will become an annual report documenting the progress made by the Chemical and Biological Nonproliferation Program (CBNP). It is intended to be a summary of the program's activities that will be of interest to both policy and technical audiences. This report and the annual CBNP Summer Review Meeting are important vehicles for communication with the broader chemical and biological defense and nonproliferation communities. The Chemical and Biological Nonproliferation Program Strategic Plan is also available and provides additional detail on the program's context and goals. The body of the report consists of an overview of the program's philosophy, goals and recent progress in the major program areas. In addition, an appendix is provided with more detailed project summaries that will be of interest to the technical community.

  11. Studies of radiation and chemical toxicity. Progress report

    International Nuclear Information System (INIS)

    1986-01-01

    Annual report for the Studies of Radiation and Chemical Toxicity Program at the University of Rochester is presented. Progress is reported on four projects: Neurobehavorial Toxicity of Organometallic Fuel Additives, Mechanisms of Permanent and Delayed Pathologic Effects of Ionizing Radiation, Solid State Radiation Chemistry of the DNA Backbone, and Pulmonary Biochemistry

  12. Selectivity on-target of bromodomain chemical probes by structure-guided medicinal chemistry and chemical biology.

    Science.gov (United States)

    Galdeano, Carles; Ciulli, Alessio

    2016-09-01

    Targeting epigenetic proteins is a rapidly growing area for medicinal chemistry and drug discovery. Recent years have seen an explosion of interest in developing small molecules binding to bromodomains, the readers of acetyl-lysine modifications. A plethora of co-crystal structures has motivated focused fragment-based design and optimization programs within both industry and academia. These efforts have yielded several compounds entering the clinic, and many more are increasingly being used as chemical probes to interrogate bromodomain biology. High selectivity of chemical probes is necessary to ensure biological activity is due to an on-target effect. Here, we review the state-of-the-art of bromodomain-targeting compounds, focusing on the structural basis for their on-target selectivity or lack thereof. We also highlight chemical biology approaches to enhance on-target selectivity.

  13. Chemical and kinetic equilibrations via radiative parton transport

    International Nuclear Information System (INIS)

    Zhang Bin; Wortman, Warner A

    2011-01-01

    A hot and dense partonic system can be produced in the early stage of a relativistic heavy ion collision. How it equilibrates is important for the extraction of Quark-Gluon Plasma properties. We study the chemical and kinetic equilibrations of the Quark-Gluon Plasma using a radiative transport model. Thermal and Color-Glass-Condensate motivated initial conditions are used. We observe that screened parton interactions always lead to partial pressure isotropization. Different initial pressure anisotropies result in the same asymptotic evolution. Comparison of evolutions with and without radiative processes shows that chemical equilibration interacts with kinetic equilibration and radiative processes can contribute significantly to pressure isotropization.

  14. Low-level radiation: biological interactions, risks, and benefits. A bibliography

    Energy Technology Data Exchange (ETDEWEB)

    None

    1978-09-01

    The bibliography contains 3294 references that were selected from the Department of Energy's data base (EDB). The subjects covered are lower-level radiation effects on man, environmental radiation, and other biological interactions of radiation that appear to be applicable to the low-level radiation problem.

  15. IAEA activities related to radiation biology and health effects of radiation

    International Nuclear Information System (INIS)

    Wondergem, Jan; Rosenblatt, Eduardo

    2012-01-01

    The IAEA is involved in capacity building with regard to the radiobiological sciences in its member states through its technical cooperation programme. Research projects/programmes are normally carried out within the framework of coordinated research projects (CRPs). Under this programme, two CRPs have been approved which are relevant to nuclear/radiation accidents: (1) stem cell therapeutics to modify radiation-induced damage to normal tissue, and (2) strengthening biological dosimetry in IAEA member states. (note)

  16. Integrated aerobic biological-chemical treatment of winery wastewater diluted with urban wastewater. LED-based photocatalysis in the presence of monoperoxysulfate.

    Science.gov (United States)

    Solís, Rafael R; Rivas, Francisco Javier; Ferreira, Leonor C; Pirra, Antonio; Peres, José A

    2018-01-28

    The oxidation of Winery Wastewater (WW) by conventional aerobic biological treatment usually leads to inefficient results due to the presence of organic substances, which are recalcitrant or toxic in conventional procedures. This study explores the combination of biological and chemical processes in order to complete the oxidation of biodegradable and non-biodegradable compounds in two sequential steps. Thus, a biological oxidation of a diluted WW is carried out by using the activated sludge process. Activated sludge was gradually acclimated to the Diluted Winery Wastewater (DWW). Some aspects concerning the biological process were evaluated (kinetics of the oxidation and sedimentation of the sludge produced). The biological treatment of the DWW led to a 40-50% of Chemical Oxygen Demand (COD) removal in 8 h, being necessary the application of an additional process. Different chemical processes combining UVA-LEDs radiation, monoperoxysulfate (MPS) and photocatalysts were applied in order to complete the COD depletion and efficient removal of polyphenols content, poorly oxidized in the previous biological step. From the options tested, the combination of UVA, MPS and a novel LaCoO 3 -TiO 2 composite, with double route of MPS decomposition through heterogeneous catalysis and photocatalysis, led to the best results (95% of polyphenol degradation, and additional 60% of COD removal). Initial MPS concentration and pH effect in this process were assessed.

  17. The contact-temperature ignition (CTI) criteria for propagating chemical reactions including the effect of moisture and application to Hanford waste

    International Nuclear Information System (INIS)

    Cash, R.J.

    1995-01-01

    To assure the continued absence of uncontrolled condensed-phase chemical reactions in connection with the Hanford waste materials, efforts have been underway including both theoretical and experimental investigations to clarify the requirements for such reactions. This document defines the differences and requirements for homogeneous runaway and propagating chemical reactions incuding a discussion of general contact-temperature ignition (CTI) condition for propagating reactions that include the effect of moisture. The CTI condition implies that the contact temperature or interface temperature between reacted and unreacted materials must exceed the ignition temperature and is compared to experimental data including both synthetic ferrocyanide and surrogate organic materials. In all cases, the occurrences of ignition accompanied by self-propagating reactions are consistent with the theoretical anticipations of the CTI condition

  18. 2-D FEM Simulation of Propagation and Radiation of Leaky Lamb Wave in a Plate-Type Ultrasonic Waveguide Sensor

    Energy Technology Data Exchange (ETDEWEB)

    Park, Sang-Jin; Kim, Hoe-Woong; Joo, Young-Sang; Kim, Sung-Kyun; Kim, Jong-Bum [KAERI, Daejeon (Korea, Republic of)

    2016-05-15

    This paper introduces the 2-D FEM simulation of the propagation and radiation of the leaky Lamb wave in and from a plate-type ultrasonic waveguide sensor conducted for the radiation beam profile analysis. The FEM simulations are performed with three different excitation frequencies and the radiation beam profiles obtained from FEM simulations are compared with those obtained from corresponding experiments. This paper deals with the 2-D FEM simulation of the propagation and radiation of the leaky Lamb wave in and from a plate-type ultrasonic waveguide sensor conducted to analyze the radiation beam profiles. The radiation beam profile results obtained from the FEM simulation show good agreement with the ones obtained from the experiment. This result will be utilized to improve the performance of the developed waveguide sensor. The quality of the visualized image is mainly affected by beam profile characteristics of the leaky wave radiated from the waveguide sensor. However, the relationships between the radiation beam profile and many parameters of the waveguide sensor are not fully revealed yet. Therefore, further parametric studies are necessary to improve the performance of the sensor and the finite element method (FEM) is one of the most effective tools for the parametric study.

  19. Adaptation hypothesis of biological efficiency of ionizing radiation

    International Nuclear Information System (INIS)

    Kudritskij, Yu.K.; Georgievskij, A.B.; Karpov, V.I.

    1992-01-01

    Adaptation hypothesis of biological efficiency of ionizing radiation is based on acknowledgement of invariance of fundamental laws and principles of biology related to unity of biota and media, evolution and adaptation for radiobiology. The basic arguments for adaptation hypothesis validity, its correspondence to the requirements imposed on scientific hypothes are presented

  20. Radiation protection in the pharmaceutical-chemical industry

    International Nuclear Information System (INIS)

    Griesser, R.

    1992-01-01

    Some aspects of the use of ionizing radiation in research in the pharmaceutical and chemical industries will be discussed, the emphasis being placed on the handling of open radioactive materials in research laboratories. The compliance with official regulations and the preparation of company internal radiation protection regulations are described. 1 tab., 9 refs

  1. Biological Sensors for Solar Ultraviolet Radiation

    Directory of Open Access Journals (Sweden)

    André P. Schuch

    2011-04-01

    Full Text Available Solar ultraviolet (UV radiation is widely known as a genotoxic environmental agent that affects Earth ecosystems and the human population. As a primary consequence of the stratospheric ozone layer depletion observed over the last decades, the increasing UV incidence levels have heightened the concern regarding deleterious consequences affecting both the biosphere and humans, thereby leading to an increase in scientific efforts to understand the role of sunlight in the induction of DNA damage, mutagenesis, and cell death. In fact, the various UV-wavelengths evoke characteristic biological impacts that greatly depend on light absorption of biomolecules, especially DNA, in living organisms, thereby justifying the increasing importance of developing biological sensors for monitoring the harmful impact of solar UV radiation under various environmental conditions. In this review, several types of biosensors proposed for laboratory and field application, that measure the biological effects of the UV component of sunlight, are described. Basically, the applicability of sensors based on DNA, bacteria or even mammalian cells are presented and compared. Data are also presented showing that on using DNA-based sensors, the various types of damage produced differ when this molecule is exposed in either an aqueous buffer or a dry solution. Apart from the data thus generated, the development of novel biosensors could help in evaluating the biological effects of sunlight on the environment. They also emerge as alternative tools for using live animals in the search for protective sunscreen products.

  2. Future of Chemical Engineering: Integrating Biology into the Undergraduate ChE Curriculum

    Science.gov (United States)

    Mosto, Patricia; Savelski, Mariano; Farrell, Stephanie H.; Hecht, Gregory B.

    2007-01-01

    Integrating biology in the chemical engineering curriculum seems to be the future for chemical engineering programs nation and worldwide. Rowan University's efforts to address this need include a unique chemical engineering curriculum with an intensive biology component integrated throughout from freshman to senior years. Freshman and Sophomore…

  3. Biological effects of the ionizing radiation. Press breakfast

    International Nuclear Information System (INIS)

    Flury-Herard, A.; Boiteux, S.; Dutrillaux, B.; Toledano, M.

    2000-06-01

    This document brings together the subjects discussed during the Press breakfast of 29 june 2000 on the biological effects of the ionizing radiations, with scientists of the CEA and the CNRS. It presents the research programs and provides inquiries on the NDA operating to introduce the NDA damages by ionizing radiations, the possible repairs and the repair efficiency facing the carcinogenesis. Those researches allow the scientists to define laws on radiation protection. (A.L.B.)

  4. Chemical and biological treatment technologies for leather tannery chemicals and wastewaters: a review.

    Science.gov (United States)

    Lofrano, Giusy; Meriç, Sureyya; Zengin, Gülsüm Emel; Orhon, Derin

    2013-09-01

    Although the leather tanning industry is known to be one of the leading economic sectors in many countries, there has been an increasing environmental concern regarding the release of various recalcitrant pollutants in tannery wastewater. It has been shown that biological processes are presently known as the most environmental friendly but inefficient for removal of recalcitrant organics and micro-pollutants in tannery wastewater. Hence emerging technologies such as advanced oxidation processes and membrane processes have been attempted as integrative to biological treatment for this sense. This paper, as the-state-of-the-art, attempts to revise the over world trends of treatment technologies and advances for pollution prevention from tannery chemicals and wastewater. It can be elucidated that according to less extent advances in wastewater minimization as well as in leather production technology and chemicals substitution, biological and chemical treatment processes have been progressively studied. However, there has not been a full scale application yet of those emerging technologies using advanced oxidation although some of them proved good achievements to remove xenobiotics present in tannery wastewater. It can be noted that advanced oxidation technologies integrated with biological processes will remain in the agenda of the decision makers and water sector to apply the best prevention solution for the future tanneries. Copyright © 2013 Elsevier B.V. All rights reserved.

  5. Current status of biological indicators to detect and quantify previous exposures to radiation. Biological Indicators Working Group

    International Nuclear Information System (INIS)

    Lushbaugh, C.; Eisele, G.; Burr, W. Jr.; Hubner, K.; Wachholz, B.

    1991-01-01

    Hematologic changes following whole-body exposure to gamma or x-ray radiation have been used to estimate dose. The usefulness of this biological indicator is limited because of the recovery of these cells with time, thus making it unsuitable for estimation of dose years after exposure. The same is true for spermatogenic indicators; recovery and restoration of sperm numbers and fertility makes this biological indicator impractical for assessing radiation dose decades after radiation exposure. As noted in the text of the report, immunological concepts are in a state of rapid development, and it is possible that improved methods for applying immunologic procedures as biological indicators of radiation may be developed in the future. However, at the time, immunological indicators are not useful, even in an early time period, for quantitating radiation dose after total-body irradiation. A semiquantitative effect is observable in the early phase after total-body irradiation over a period of days to weeks, but there is little data available to indicate whether any of the immunological parameters can be indicative of a dose when the test is applied several years after radiation exposure. More detailed information regarding immunological indicators for estimating irradiation dose has been summarized elsewhere (Wasserman 1986). There is good agreement that ionizing radiation causes biochemical changes in the body; however, attempts to apply these changes to provide a reliable biological dosimetry system have not been particularly successful. The status of this research has been summarized by Gerber (1986). One of the difficulties has been the problem of establishing clear dose-effect relationships in humans. The lack of specificity in the response for radiation is another problem

  6. Modification of biomolecules and combined actions by radiation

    International Nuclear Information System (INIS)

    Kim, Jin Kyu; Lee, J. W.; Kim, J. H.; Choi, J. I.; Song, B. S.; Kim, J. K.; Park, J. H.; Lee, Y. J.; Ryu, S. H.; Sung, N. Y.; Cha, M. K.; Nam, J. Y.; Park, J. Y.; Cho, E. R.; Ryu, T. H.

    2011-12-01

    Advanced Radiation Technology Institute is a government-supported institute for radiation research and application. It has focused on development of fundamentals for radiation applications based on the existing radiation technology, and on enhancement of biological effectiveness of radiation through theoretical approach to the combined actions of radiation with another factor. Application of radiation technology together with the existing technologies to enhance the physical, chemical, biological characteristics through modification of biomolecules resulted in creation of de novo materials of scientific and industrial values. A theoretical model for combined action of radiation with another physico-chemical factor has been established. Conclusively the results of this study can provide scientific bases for maximizing the efficacy of ionizing radiation in relation to industrial applications

  7. Diazo Compounds: Versatile Tools for Chemical Biology

    OpenAIRE

    Mix, Kalie A.; Aronoff, Matthew R.; Raines, Ronald T.

    2016-01-01

    Diazo groups have broad and tunable reactivity. That and other attributes endow diazo compounds with the potential to be valuable reagents for chemical biologists. The presence of diazo groups in natural products underscores their metabolic stability and anticipates their utility in a biological context. The chemoselectivity of diazo groups, even in the presence of azido groups, presents many opportunities. Already, diazo compounds have served as chemical probes and elicited novel modificatio...

  8. Construction of a Linux based chemical and biological information system.

    Science.gov (United States)

    Molnár, László; Vágó, István; Fehér, András

    2003-01-01

    A chemical and biological information system with a Web-based easy-to-use interface and corresponding databases has been developed. The constructed system incorporates all chemical, numerical and textual data related to the chemical compounds, including numerical biological screen results. Users can search the database by traditional textual/numerical and/or substructure or similarity queries through the web interface. To build our chemical database management system, we utilized existing IT components such as ORACLE or Tripos SYBYL for database management and Zope application server for the web interface. We chose Linux as the main platform, however, almost every component can be used under various operating systems.

  9. Propagation and radiation characteristics of the circular electric, circular magnetic and hybrid waveguide modes

    International Nuclear Information System (INIS)

    Crenn, J.P.

    1996-06-01

    The field distributions and propagation constants of the circular electric, circular magnetic and hybrid modes of oversized waveguides are expressed, taking the effects of walls into account. The near and far field patterns are derived in the case of real wall functions. It is shown that, for very oversized waveguides, the terms containing wall functions can be ignored in the calculations, and it results that the expressions of fields and propagation constants become independent of the types of waveguides. An application to corrugated waveguides for Electron Cyclotron Resonance Heating experiments shows the variations of the radiation characteristics versus geometric parameters of the corrugations and determines the ranges of interest for these parameters. (author)

  10. The need for and the importance of biological indicators of radiation effects with special reference to injuries in radiation accidents

    International Nuclear Information System (INIS)

    Koeteles, G.J.; Bianco, A.

    1982-01-01

    The need for further research on the existing and new biological indicators of radiation injury has been expressed. The studies on the radiation-induced alterations of membrane structure and function stimulated investigations aiming to develop an indicator based on membrane-phenomena. The co-ordinated research programme on ''Cell Membrane Probes as Biological Indicators of Radiation Injury in Radiation Accidents'' was initiated in mid 1977 and terminated in 1980. Within this programme many basic observations were made in connection with altered features of various animal and human cell membranes. Molecular, biophysical, biochemical and cell biological approaches were performed. The rapid reaction within minutes or hours of membranes against relatively low doses of various types of irradiations were described and the effects proved to be transitory, i.e. membrane regeneration occurred within hours. These dose- and timedependent alterations suggest the possibility of developing a biological indicator which would give signals at the earliest period after radiation injury when no other biological informations are available. The importance of a system of biological indicators is emphasized. (author)

  11. Biophysical interpretation on the biological actions of radiations

    Energy Technology Data Exchange (ETDEWEB)

    Nishiwaki, Yasushi

    1960-12-08

    It is known that nuclear radiations such as alpha, beta, gamma, x-rays and neutron, proton and other heavy ion beams have many different actions on living cells; as killing, delaying growth, abnormal cell divisions and various genetical mutations and chromosomal aberrations. This document describes the mechanisms and kinetics of biological effects of ionizing radiation.

  12. Biophysical interpretation on the biological actions of radiations

    International Nuclear Information System (INIS)

    Nishiwaki, Yasushi

    1960-01-01

    It is known that nuclear radiations such as alpha, beta, gamma, x-rays and neutron, proton and other heavy ion beams have many different actions on living cells; as killing, delaying growth, abnormal cell divisions and various genetical mutations and chromosomal aberrations. This document describes the mechanisms and kinetics of biological effects of ionizing radiation

  13. On flame kernel formation and propagation in premixed gases

    Energy Technology Data Exchange (ETDEWEB)

    Eisazadeh-Far, Kian; Metghalchi, Hameed [Northeastern University, Mechanical and Industrial Engineering Department, Boston, MA 02115 (United States); Parsinejad, Farzan [Chevron Oronite Company LLC, Richmond, CA 94801 (United States); Keck, James C. [Massachusetts Institute of Technology, Cambridge, MA 02139 (United States)

    2010-12-15

    Flame kernel formation and propagation in premixed gases have been studied experimentally and theoretically. The experiments have been carried out at constant pressure and temperature in a constant volume vessel located in a high speed shadowgraph system. The formation and propagation of the hot plasma kernel has been simulated for inert gas mixtures using a thermodynamic model. The effects of various parameters including the discharge energy, radiation losses, initial temperature and initial volume of the plasma have been studied in detail. The experiments have been extended to flame kernel formation and propagation of methane/air mixtures. The effect of energy terms including spark energy, chemical energy and energy losses on flame kernel formation and propagation have been investigated. The inputs for this model are the initial conditions of the mixture and experimental data for flame radii. It is concluded that these are the most important parameters effecting plasma kernel growth. The results of laminar burning speeds have been compared with previously published results and are in good agreement. (author)

  14. Mitigate the tent-induced perturbation in ignition capsules by supersonic radiation propagation

    Science.gov (United States)

    Dai, Zhensheng; Gu, Jianfa; Zheng, Wudi

    2017-10-01

    In the inertial confinement fusion (ICF) scheme, to trap the alpha particle products of the D-T reaction, the capsules needs to be imploded and compressed with high symmetry In the laser indirect drive scheme, the capsules are held at the center of high-Z hohlraums by thin membranes (tents). However, the tents are recognized as one of the most important contributors to hot spot asymmetries, areal density perturbations and reduced performance. To improve the capsule implosion performance, various alternatives such as the micro-scale rods, a larger fill-tube and a low-density foam layer around the capsule have been presented. Our simulations show that the radiation propagates supersonically in the low-density foam layer and starts to ablate the capsule before the perturbations induced by the tents reach the ablating fronts. The tent induced perturbations are remarkably weakened when they are propagating in the blow-off plasma.

  15. Chemical and biological warfare. Should defenses be researched and deployed?

    Science.gov (United States)

    Orient, J M

    1989-08-04

    The threat of chemical and biological weapons of mass destruction has intensified because of improved delivery systems and advances in chemistry, genetics, and other sciences. Possible US responses to this threat include deterrence, defenses, and/or disarmament, including a reaffirmation of the Biological and Toxin Weapons Convention of 1972, which is now in jeopardy. This article discusses the history of chemical and biological warfare, existing and potential weapons, the proliferation of weapons and delivery systems, ways to prevent the use of these weapons, and ways to protect populations from their effects.

  16. Bragg Curve, Biological Bragg Curve and Biological Issues in Space Radiation Protection with Shielding

    Science.gov (United States)

    Honglu, Wu; Cucinotta, F.A.; Durante, M.; Lin, Z.; Rusek, A.

    2006-01-01

    The space environment consists of a varying field of radiation particles including high-energy ions, with spacecraft shielding material providing the major protection to astronauts from harmful exposure. Unlike low-LET gamma or X-rays, the presence of shielding does not always reduce the radiation risks for energetic charged particle exposure. Since the dose delivered by the charged particle increases sharply as the particle approaches the end of its range, a position known as the Bragg peak, the Bragg curve does not necessarily represent the biological damage along the particle traversal since biological effects are influenced by the track structure of both primary and secondary particles. Therefore, the biological Bragg curve is dependent on the energy and the type of the primary particle, and may vary for different biological endpoints. To achieve a Bragg curve distribution, we exposed cells to energetic heavy ions with the beam geometry parallel to a monolayer of fibroblasts. Qualitative analyses of gamma-H2AX fluorescence, a known marker of DSBs, indicated increased clustering of DNA damage before the Bragg peak, enhanced homogenous distribution at the peak, and provided visual evidence of high linear energy transfer (LET) particle traversal of cells beyond the Bragg peak. A quantitative biological response curve generated for micronuclei (MN) induction across the Bragg curve did not reveal an increased yield of MN at the location of the Bragg peak. However, the ratio of mono-to bi-nucleated cells, which indicates inhibition in cell progression, increased at the Bragg peak location. These results, along with other biological concerns, show that space radiation protection with shielding can be a complicated issue.

  17. Proceedings of the symposium on molecular biology and radiation protection

    International Nuclear Information System (INIS)

    Marko, A.M.

    1996-02-01

    The symposium on molecular biology and radiation protection was organized in sessions with the following titles: Radiation protection and the human genome; Molecular changes in DNA induced by radiation; Incidence of genetic changes - pre-existing, spontaneous and radiation-induced; Research directions and ethical implications. The ten papers in the symposium have been abstracted individually

  18. Proceedings of the symposium on molecular biology and radiation protection

    Energy Technology Data Exchange (ETDEWEB)

    Marko, A M [Atomic Energy Control Board, Ottawa, ON (Canada). Advisory Committee on Radiological Protection; Myers, D K; Atchison, R J [Atomic Energy Control Board, Ottawa, ON (Canada). Advisory Committee on Radiological Protection. Secretariat; Gentner, N E [Atomic Energy of Canada Ltd., Chalk River, ON (Canada)

    1996-02-01

    The symposium on molecular biology and radiation protection was organized in sessions with the following titles: Radiation protection and the human genome; Molecular changes in DNA induced by radiation; Incidence of genetic changes - pre-existing, spontaneous and radiation-induced; Research directions and ethical implications. The ten papers in the symposium have been abstracted individually.

  19. International Journal of Biological and Chemical Sciences ...

    African Journals Online (AJOL)

    The International Journal of Biological and Chemical Sciences (IJBCS) is a journal ... c) Short Communication (maximum: 10 pages, 20 references). d) Case ... Abstract: All articles should be provided with an abstract not exceeding 200 words.

  20. Aum Shinrikyo's Chemical and Biological Weapons: More Than Sarin.

    Science.gov (United States)

    Tu, A T

    2014-07-01

    The radical religious group Aum Shinrikyo was founded in Japan in the 1980s and grew rapidly in the 1990s. Aum members perpetrated a mass murder in Matsumoto City in 1994, where they used sarin as a chemical weapon to poison approximately 500 civilians. On March 20, 1995, Aum deployed sarin in an even larger terrorist attack on the Tokyo Subway System, which poisoned some 6,000 people. After the Tokyo Subway attack, the Japanese Police arrested the sect's senior members. From 2005 through 2011, 13 of these senior members were sentenced to death. In this article, aspects of Aum's chemical and biological terrorism are reviewed. Sarin production efforts by the sect are described, including how the degradation product of sarin in soil, methylphosphonic acid, enabled the detection of sarin production sites. Also, Aum's chemical-warfare agents other than sarin are described, as are its biological weapons. The author was permitted by the Japanese government to interview Dr. Tomomasa Nakagawa, one of the senior members of Aum Shinrikyo. From Dr. Nakagawa the author obtained valuable inside information about Aum's chemical and biological weapons programs. Copyright © 2014 Central Police University.

  1. Personal recollections of radiation biology research at Hanford

    International Nuclear Information System (INIS)

    Thompson, R.C.

    1995-01-01

    This paper traces the evolution of the Hanford biology programme over a period of nearly five decades. The programme began in the 1940s with a focus on understanding the potential health effects of radionuclides such as 131 I associated with fallout from the atomic bomb. These studies were extended in the 1950s to experiments on the toxicity and metabolism of plutonium and fission products such as 90 Sr and 137 Cs. In the 1960s, a major long term project was initiated on the inhalation toxicology and carcinogenic effects of plutonium oxide and plutonium nitrate in dogs and rodents. The project remained a major effort within the overall Hanford biology programme throughout the 1970s and 1980s, during which time a broad range of new projects on energy-related pollutants, radon health effects, and basic radiation biology were initiated. Despite the many evolutionary changes that have occurred in the Hanford biology programme, the fundamental mission of understanding the effects of radiation on human health has endured for nearly five decades. (author)

  2. Ecological and nonhuman biological effects of solar UV-B radiation

    International Nuclear Information System (INIS)

    Worrest, R.C.

    1984-01-01

    Recent studies regarding the impact of UV-B radiation upon ecological and nonhuman biological systems is the subject of the report. For years scientists and laymen alike have causally noted the impact of solar ultraviolet radiation upon the nonhuman component of the biosphere. Stratospheric ozone functions effectively as an ultraviolet screen by filtering out solar radiation in the 220-320 nm waveband as it penetrates through the atmosphere, thus allowing only small amounts of the longer wavelengths of radiation in the waveband to leak through to the surface of the earth. Although this radiation (UV-B radiation, 290-320 nm) comprises only a small fraction (lesser tha 1%) of the total solar spectrum, it can have a major impact on biological systems due to its actinic nature. Many organic molecules, most notably DNA, absorb UV-B radiation which can initiate photochemical reactions. It is life's ability, or lack thereof, to cope with enhanced levels of solar UV-B radiation that has generated concern over the potential depletion of stratospheric ozone

  3. A new radiation biology: epigenetics, exosomes and metabolism

    International Nuclear Information System (INIS)

    Atkinson, M.J.

    2016-01-01

    Exposure to ionizing radiation leads to chronic disease, including cancer, cardiovascular disease, neurocognitive deficits and possibly metabolic diseases. The prevailing paradigm of radiation biology considers DNA damage to be the initiating event. Misrepair of initial DNA damage leads to gene mutations that promote clonal expansion and eventually malignancy. However, the paradigm is inconsistent with some recent radiobiological observations

  4. The molecular theory of radiation biology

    International Nuclear Information System (INIS)

    Chadwick, K.H.; Leenhouts, H.P.

    1981-01-01

    In this book we have tried to gather, in a logical sequence, the thoughts and reasoning which have led us from the raw and primitive beginning to the broader, more generally applicable, model. In doing this, it has been necessary to cover a wide range of topics in both cellular biology and radiation physics, and we apologize now to the reader who finds that we have gone into too much detail in one area and made too rough an approximation in the other. We have written what we feel is essential for the physicist to follow the influence exerted on the model by the biology, and for the biologist to follow the mathematical definition of the biological effect. (orig./VJ)

  5. Study on the radiation-induced biological responses based on the analysis of metabolites

    International Nuclear Information System (INIS)

    Jo, Sungkee; Jung, Uhee; Park, Haeran; Roh, Changhyun; Shin, Heejune; Ryu, Dongkyoung

    2013-01-01

    1. Objectives □ Establishment of basis of biological radiation response study by metabolite analysis 2. Project results □ Establishment of analytical basis of radiation-responsive metabolites in biological samples - Large scale collection of tissue samples from irradiated animal for radiation metabolomics research - Establishment of mass spectromety (GC MS, LC MS-MS) analysis methods of biological samples - 3 Standard Operation Protocols (SOP) for ultra high resolution mass spectrometry (FT-ICR MS, Q-TOF MS) analysis of metabolites from biological samples - Establishment of database for radiation metabolites □ Basic research on radiation-responsive metabolites and the interpretation of their functions - Validation of spermidine as a candidate biomarker of acute radiation response in mouse blood - Verification of 5 radiation-responsive steroid hormones and alteration of their metabolic enzyme activities in mouse blood - Verification of 13 radiation-responsive amino acids (related to oxidative stress, neurotransmission, energy metabolism) in regional mouse brain -Verification of 10 radiation-responsive amino acids (related to oxidative stress, neurotransmission, energy metabolism) in regional mouse brain - Verification of 74 radiation-responsive metabolites in whole rat brain by ultra high resolution FT-ICR MS and Q-TOF MS analysis 3. Expected benefits and plan of application □ Establishment of research basis of radiation metabolomics in Korea □ Provision of core technology in radiation bioscience and safety field by application of radiation metabolomics results to the technology development in radiation biodosimetry, and radiation response evaluation and modulation

  6. Study on the radiation-induced biological responses based on the analysis of metabolites

    Energy Technology Data Exchange (ETDEWEB)

    Jo, Sungkee; Jung, Uhee; Park, Haeran; Roh, Changhyun; Shin, Heejune; Ryu, Dongkyoung

    2013-01-15

    1. Objectives □ Establishment of basis of biological radiation response study by metabolite analysis 2. Project results □ Establishment of analytical basis of radiation-responsive metabolites in biological samples - Large scale collection of tissue samples from irradiated animal for radiation metabolomics research - Establishment of mass spectromety (GC MS, LC MS-MS) analysis methods of biological samples - 3 Standard Operation Protocols (SOP) for ultra high resolution mass spectrometry (FT-ICR MS, Q-TOF MS) analysis of metabolites from biological samples - Establishment of database for radiation metabolites □ Basic research on radiation-responsive metabolites and the interpretation of their functions - Validation of spermidine as a candidate biomarker of acute radiation response in mouse blood - Verification of 5 radiation-responsive steroid hormones and alteration of their metabolic enzyme activities in mouse blood - Verification of 13 radiation-responsive amino acids (related to oxidative stress, neurotransmission, energy metabolism) in regional mouse brain -Verification of 10 radiation-responsive amino acids (related to oxidative stress, neurotransmission, energy metabolism) in regional mouse brain - Verification of 74 radiation-responsive metabolites in whole rat brain by ultra high resolution FT-ICR MS and Q-TOF MS analysis 3. Expected benefits and plan of application □ Establishment of research basis of radiation metabolomics in Korea □ Provision of core technology in radiation bioscience and safety field by application of radiation metabolomics results to the technology development in radiation biodosimetry, and radiation response evaluation and modulation.

  7. Epidemiological and radio-biological studies in high background radiation areas of Kerala coast: implications in radiation protection science and human health

    International Nuclear Information System (INIS)

    Das, Birajalaxmi

    2018-01-01

    Till date, Linear No Threshold hypothesis (LNT) is well accepted in radiation protection science in spite of its limitations. However, dose response studies using multiple biological end points from high-background radiation areas have challenged the linearity. Radio-biological and epidemiological studies from high level natural radiation areas of Kerala coast showed non-linearity as well as efficient repair of DNA damage in HLNRA indicating that dose limits for public exposure needs to be revisited which may have implications in radiation protection science, human health and low dose radiation biology. However, further studies using high throughput approach is required to identify chronic radiation signatures in human population exposed to elevated level of natural background radiation

  8. Diazo Compounds: Versatile Tools for Chemical Biology.

    Science.gov (United States)

    Mix, Kalie A; Aronoff, Matthew R; Raines, Ronald T

    2016-12-16

    Diazo groups have broad and tunable reactivity. That and other attributes endow diazo compounds with the potential to be valuable reagents for chemical biologists. The presence of diazo groups in natural products underscores their metabolic stability and anticipates their utility in a biological context. The chemoselectivity of diazo groups, even in the presence of azido groups, presents many opportunities. Already, diazo compounds have served as chemical probes and elicited novel modifications of proteins and nucleic acids. Here, we review advances that have facilitated the chemical synthesis of diazo compounds, and we highlight applications of diazo compounds in the detection and modification of biomolecules.

  9. Chemical and biological nonproliferation program. FY99 annual report; ANNUAL

    International Nuclear Information System (INIS)

    NONE

    2000-01-01

    This document is the first of what will become an annual report documenting the progress made by the Chemical and Biological Nonproliferation Program (CBNP). It is intended to be a summary of the program's activities that will be of interest to both policy and technical audiences. This report and the annual CBNP Summer Review Meeting are important vehicles for communication with the broader chemical and biological defense and nonproliferation communities. The Chemical and Biological Nonproliferation Program Strategic Plan is also available and provides additional detail on the program's context and goals. The body of the report consists of an overview of the program's philosophy, goals and recent progress in the major program areas. In addition, an appendix is provided with more detailed project summaries that will be of interest to the technical community

  10. Biological effects of radiation human health and safety

    International Nuclear Information System (INIS)

    1977-05-01

    The biological hazards of nuclear energy usage are a growing source of public concern. The medical profession may well be expected to contribute to public debate on the issue. This document, therefore, attempts a balanced review of the known and suspected human biological consequences of exposure to different types of ionizing radiation, emphasizing in particular the nuclear industry

  11. Radiation chemical transformations of some polyarylates by γ-radiation in vacuum

    International Nuclear Information System (INIS)

    Lyashevich, V.V.; Korshak, V.V.; Rodeh, V.V.; Timofeeva, G.I.

    1976-01-01

    A study was made of ageing by radiation of F-2 and D-9 polyarylates using γ-radiation in vacuum. Their high resistance to radiation was indicated. It was found that γ-radiation on polymers caused competing reactions to take place resulting in macromolecular breakdown and structure formation, which in the end produced threedimensional network formation. The initial formation of gel fractions was preceded by the formation of branched macromolecules. The radiation resistance of polyarylates depends on the type of lateral substituent at the central carbon atom of the initial bis-phenol and increases in the presence of a fluorene ring in the lateral chain. The radiation resistance of a lactone ring is lower than that of an ether bond of the main chain. It was shown that 0-hydroxy-ketone structures were formed in the polyarylates examined as a result of regrouping due to radiation. A basic system is proposed for chemical conversion of polyarylates by radiation

  12. Radiation oncology - Linking technology and biology in the treatment of cancer

    International Nuclear Information System (INIS)

    Coleman, C. Norman

    2002-01-01

    Technical advances in radiation oncology including CT-simulation, 3D-conformal and intensity-modulated radiation therapy (IMRT) delivery techniques, and brachytherapy have allowed greater treatment precision and dose escalation. The ability to intensify treatment requires the identification of the critical targets within the treatment field, recognizing the unique biology of tumor, stroma and normal tissue. Precision is technology based while accuracy is biologically based. Therefore, the intensity of IMRT will undoubtedly mean an increase in both irradiation dose and the use of biological agents, the latter considered in the broadest sense. Radiation oncology has the potential and the opportunity to provide major contributions to the linkage between molecular and functional imaging, molecular profiling and novel therapeutics for the emerging molecular targets for cancer treatment. This process of 'credentialing' of molecular targets will require multi disciplinary imaging teams, clinicians and basic scientists. Future advances will depend on the appropriate integration of biology into the training of residents, continuing post graduate education, participation in innovative clinical research and commitment to the support of basic research as an essential component of the practice of radiation oncology

  13. Chemical and Biological Evaluation of Whey

    International Nuclear Information System (INIS)

    Mohamed, N.E.; Anwar, M.M.

    2013-01-01

    This Study has been carried out to extract whey protein concentrate (WPC) from sweet whey and to study the chemical composition, amino acids composition, amino acid scores and to investigate the possible role of WPC in ameliorating some biochemical disorders induced in γ-irradiated rats. Animals were divided into 4 groups. Group 1, fed on normal diet during experimental period. Group 2, fed on diet containing 15% WPC instead of soybean protein. Group 3, rats exposed to whole body γ-radiation with single dose of 5 Gy and fed on the normal diet. Group 4, rats exposed to 5 Gy then fed on diet containing 15% WPC. The rats were decapitated 14 and 28 days post irradiation. Chemical analysis of WPC revealed that it contains high amounts of protein (44%), total amino acids (71%) and all essential amino acids (EAA), phenylalanine (37%), isoleucine cystine and threonine were the major EAA and high amounts of sulphur amino acids. Methionine gave rich chemical score (102.67%) also, isoleucine (119.95%) and phenylalanine+ tyrosine gave maximum chemical score (198.8%), respectively. Exposure to γ-irradiation caused significant elevation of serum cholesterol, triglycerides, low density lipoprotein (LDL), lipid per oxidation end product (TBARS) and iron (Fe) with significant decrease in high density lipoprotein (HDL), glutathione (GSH) and catalase (CAT) in serum. Also, irradiated rats had significant decrease in copper (Cu), magnesium (Mg) and zinc (Zn) in serum. The histological examination of cardiac tissue showed severe structural damage. Irradiated rats fed on WPC revealed significant improvement of some biochemical parameters. It could be concluded that WPC must be added to diet for reducing radiation injury via metabolic pathway

  14. Propagation of SLF/ELF electromagnetic waves

    CERN Document Server

    Pan, Weiyan

    2014-01-01

    This book deals with the SLF/ELF wave propagation, an important branch of electromagnetic theory. The SLF/ELF wave propagation theory is well applied in earthquake electromagnetic radiation, submarine communication, thunderstorm detection, and geophysical prospecting and diagnostics. The propagation of SLF/ELF electromagnetic waves is introduced in various media like the earth-ionospheric waveguide, ionospheric plasma, sea water, earth, and the boundary between two different media or the stratified media. Applications in the earthquake electromagnetic radiation and the submarine communications are also addressed. This book is intended for scientists and engineers in the fields of radio propagation and EM theory and applications. Prof. Pan is a professor at China Research Institute of Radiowave Propagation in Qingdao (China). Dr. Li is a professor at Zhejiang University in Hangzhou (China).

  15. Towards biologically conformal radiation therapy (BCRT): Selective IMRT dose escalation under the guidance of spatial biology distribution

    International Nuclear Information System (INIS)

    Yang Yong; Xing Lei

    2005-01-01

    It is well known that the spatial biology distribution (e.g., clonogen density, radiosensitivity, tumor proliferation rate, functional importance) in most tumors and sensitive structures is heterogeneous. Recent progress in biological imaging is making the mapping of this distribution increasingly possible. The purpose of this work is to establish a theoretical framework to quantitatively incorporate the spatial biology data into intensity modulated radiation therapy (IMRT) inverse planning. In order to implement this, we first derive a general formula for determining the desired dose to each tumor voxel for a known biology distribution of the tumor based on a linear-quadratic model. The desired target dose distribution is then used as the prescription for inverse planning. An objective function with the voxel-dependent prescription is constructed with incorporation of the nonuniform dose prescription. The functional unit density distribution in a sensitive structure is also considered phenomenologically when constructing the objective function. Two cases with different hypothetical biology distributions are used to illustrate the new inverse planning formalism. For comparison, treatments with a few uniform dose prescriptions and a simultaneous integrated boost are also planned. The biological indices, tumor control probability (TCP) and normal tissue complication probability (NTCP), are calculated for both types of plans and the superiority of the proposed technique over the conventional dose escalation scheme is demonstrated. Our calculations revealed that it is technically feasible to produce deliberately nonuniform dose distributions with consideration of biological information. Compared with the conventional dose escalation schemes, the new technique is capable of generating biologically conformal IMRT plans that significantly improve the TCP while reducing or keeping the NTCPs at their current levels. Biologically conformal radiation therapy (BCRT

  16. The biological effectiveness of heavy ion radiations in the environment

    International Nuclear Information System (INIS)

    Craven, P.A.

    1996-03-01

    Although heavy ions are rarely encountered in the majority of terrestrial environments, the exposure of humans to this fascinating class of ionizing radiation is becoming more frequent. Long-duration spaceflight, new radiotherapeutic procedures and enhanced levels of radon, and other naturally-occurring alpha particle emitters, have all increased concern and stimulated interest recently within the radiological protection and radiobiological communities. Significant data concerning the long-term effects of low levels of heavy ions on mammalian systems are correspondingly scarce, leading to increased emphasis on modelling all aspects of the radiation-organism interaction. Contemporary radiation protection procedures reflect the need for a more fundamental understanding of the mechanisms responsible for the biological actions of such radiations. Major deficiencies exist in the current recommendations for assessment of relative effectiveness, the enhanced severity of the biological consequences instigated by heavy ions, over conventional sparsely ionizing radiations. In an attempt to remedy some of the inadequate concepts and assumptions presently employed and, simultaneously, to gain insight into the fundamental mechanisms behind the notion of radiation quality, a series of algorithms have been developed and executed as computer code, to evaluate the biological effectiveness of heavy ion radiation ''tracks'' according to a number of criteria. These include consideration of the spatial characteristics of physical energy deposition in idealised cellular structures (finite particle range, radial extension of tracks via δ-ray emission) and the likelihood of induction and mis-repair of severe molecular lesions (double-strand breaks, multiply-damaged sites). (author)

  17. Waste water treatment by ionizing radiations. Removal of biological and chemical risks by water and sludge treatment with electron beams. Orientation 10 July 2002

    International Nuclear Information System (INIS)

    2002-01-01

    This report aims at analysing the reliability of the application of electron ionizing radiation in the treatment of waste waters and effluents, and at identifying possible fields of application and associated technological and economic implications. After some recalls on physics, electrochemistry, radiolysis, and water pollution, the report proposes an overview of the technique of irradiation of waters, with its scientific background (water radiolysis, chemical and biological effects), its process (recovery cycle and possible interventions, processed pollutants), the case of irradiation by electrons (power, rate, flexibility), an overview of benefits and drawbacks, and a brief history of this practice and an overview of current researches. After a recall of regulatory and political requirements, the report discusses possible fields of application: waste water treatment plants, domestic, agricultural and urban sewage wasters, hospital and medical wastes, liquid food industry products, industrial waters. The choice of accelerator parameters and components is then discussed

  18. A survey of chemicals inducing lipid peroxidation in biological systems.

    Science.gov (United States)

    Kappus, H

    1987-01-01

    A great number of drugs and chemicals are reviewed which have been shown to stimulate lipid peroxidation in any biological system. The underlying mechanisms, as far as known, are also dealt with. Lipid peroxidation induced by iron ions, organic hydroperoxides, halogenated hydrocarbons, redox cycling drugs, glutathione depleting chemicals, ethanol, heavy metals, ozone, nitrogen dioxide and a number of miscellaneous compounds, e.g. hydrazines, pesticides, antibiotics, are mentioned. It is shown that lipid peroxidation is stimulated by many of these compounds. However, quantitative estimates cannot be given yet and it is still impossible to judge the biological relevance of chemical-induced lipid peroxidation.

  19. Radiation biology and radiation protection

    International Nuclear Information System (INIS)

    Hendry, J.H.

    2012-01-01

    For protection purposes, the biological effects of radiation are separated into stochastic effects (cancer, hereditary effects) presumed to be unicellular in origin, and tissue reactions due to injury in populations of cells. The latter are deterministic effects, renamed ‘tissue reactions’ in the 2007 Recommendations of the International Commission on Radiological Protection because of the increasing evidence of the ability to modify responses after irradiation. Tissue reactions become manifest either early or late after doses above a threshold dose, which is the basis for recommended dose limits for avoiding such effects. Latency time before manifestation is related to cell turnover rates, and tissue proliferative and structural organisation. Threshold doses have been defined for practical purposes at 1% incidence of an effect. In general, threshold doses are lower for longer follow-up times because of the slow progression of injury before manifestation. Radiosensitive individuals in the population may contribute to low threshold doses, and in the future, threshold doses may be increased by the use of various biological response modifiers post irradiation for reducing injury. Threshold doses would be expected to be higher for fractionated or protracted doses, unless doses below the threshold dose only cause single-hit-type events that are not modified by repair/recovery phenomena, or if different mechanisms of injury are involved at low and high doses.

  20. Radiation-chemical disinfection of dissolved impurities and environmental protection

    International Nuclear Information System (INIS)

    Petrukhin, N.V.; Putilov, A.V.

    1986-01-01

    Radiation-chemical neutralization of dissolved toxic impurities formed in the production processes of different materials, while modern plants being in use, is considered. For the first time the processes of deep industrial waste detoxication and due to this peculiarities of practically thorough neutralization of dissolved toxic impurities are considered. Attention is paid to devices and economic factors of neutralization of dissolved toxic impurities. The role of radiation-chemical detoxication for environment protection is considered

  1. Technical sheets of ionizing radiations. 2. Non-ionizing radiations

    International Nuclear Information System (INIS)

    Anon.

    1975-01-01

    The biological effects of different non-ionizing radiations are studied: ultra-violet radiation, visible radiation, infrared radiation, micrometric waves, ultrasonics. In spite of their apparent diversity these radiations are similar in their physico-chemical effects, but in view of their widely varying production methods and types of application each type is considered separately. It is pointed out that no organization resembling the CIPR exists in the field of non-ionizing radiations, the result being a great disparity amongst the different legislations in force [fr

  2. Experimental and theoretical studies of near-ground acoustic radiation propagation in the atmosphere

    Science.gov (United States)

    Belov, Vladimir V.; Burkatovskaya, Yuliya B.; Krasnenko, Nikolai P.; Rakov, Aleksandr S.; Rakov, Denis S.; Shamanaeva, Liudmila G.

    2017-11-01

    Results of experimental and theoretical studies of the process of near-ground propagation of monochromatic acoustic radiation on atmospheric paths from a source to a receiver taking into account the contribution of multiple scattering on fluctuations of atmospheric temperature and wind velocity, refraction of sound on the wind velocity and temperature gradients, and its reflection by the underlying surface for different models of the atmosphere depending the sound frequency, coefficient of reflection from the underlying surface, propagation distance, and source and receiver altitudes are presented. Calculations were performed by the Monte Carlo method using the local estimation algorithm by the computer program developed by the authors. Results of experimental investigations under controllable conditions are compared with theoretical estimates and results of analytical calculations for the Delany-Bazley impedance model. Satisfactory agreement of the data obtained confirms the correctness of the suggested computer program.

  3. Time evolution of photon-pulse propagation in scattering and absorbing media: The dynamic radiative transfer system

    Science.gov (United States)

    Georgakopoulos, A.; Politopoulos, K.; Georgiou, E.

    2018-03-01

    A new dynamic-system approach to the problem of radiative transfer inside scattering and absorbing media is presented, directly based on first-hand physical principles. This method, the Dynamic Radiative Transfer System (DRTS), employs a dynamical system formality using a global sparse matrix, which characterizes the physical, optical and geometrical properties of the material-volume of interest. The new system state is generated by the above time-independent matrix, using simple matrix-vector multiplication for each subsequent time step. DRTS is capable of calculating accurately the time evolution of photon propagation in media of complex structure and shape. The flexibility of DRTS allows the integration of time-dependent sources, boundary conditions, different media and several optical phenomena like reflection and refraction in a unified and consistent way. Various examples of DRTS simulation results are presented for ultra-fast light pulse 3-D propagation, demonstrating greatly reduced computational cost and resource requirements compared to other methods.

  4. The terrorist threat nuclear, radiological, biological, chemical - a medical approach

    International Nuclear Information System (INIS)

    Revel, M.C. de; Gourmelon, M.C.S.; Vidal, P.C.; Renaudeau, P.C.S.

    2005-01-01

    Since September 11, 2001, the fear of a large scale nuclear, biological and/or chemical terrorism is taken again into consideration at the highest level of national policies of risk prevention. The advent of international terrorism implies a cooperation between the military defense and the civil defense. The nuclear, radiological, biological and chemical (NRBC) experts of the health service of army and of civil defense will have to work together in case of major terror attack. This book presents this cooperation between civil and military experts in the NRBC domain: risk analysis, national defense plans, crisis management, syndromes and treatments. The different aspects linked with the use of nuclear, biological and chemical weapons are analyzed by the best experts from French medical and research institutes. All topics of each NRBC domain are approached: historical, basic, diagnostic, therapeutic and preventive. (J.S.)

  5. Microwave radiation - Biological effects and exposure standards

    Energy Technology Data Exchange (ETDEWEB)

    Lindsay, I.R.

    1980-06-01

    The thermal and nonthermal effects of exposure to microwave radiation are discussed and current standards for microwave exposure are examined in light of the proposed use of microwave power transmission from solar power satellites. Effects considered include cataractogenesis at levels above 100 mW/sq cm, and possible reversible disturbances such as headaches, sleeplessness, irritability, fatigue, memory loss, cardiovascular changes and circadian rhythm disturbances at levels less than 10 mW/sq cm. It is pointed out that while the United States and western Europe have adopted exposure standards of 10 mW/sq cm, those adopted in other countries are up to three orders of magnitude more restrictive, as they are based on different principles applied in determining safe limits. Various aspects of the biological effects of microwave transmissions from space are considered in the areas of the protection of personnel working in the vicinity of the rectenna, interactions of the transmitted radiation with cardiac pacemakers, and effects on birds. It is concluded that thresholds for biological effects from short-term microwave radiation are well above the maximal power density of 1 mW/sq cm projected at or beyond the area of exclusion of a rectenna.

  6. Methane Fermentation of Slurry with Chemical and Biological Additive

    Directory of Open Access Journals (Sweden)

    Anna Smurzyńska

    2017-12-01

    Full Text Available The problem of proper slurry management is primarily present in intensive livestock production. Industrialized livestock farms generate enormous quantities of manure droppings in a livestock-litter-free system. The traditional management of slurry is made by using it as a fertilizer. Alternative techniques used for neutralizing the detrimental effect of slurry are based on the use of chemical and biological additives, as well as by introducing aerobic environment through aerobic or anaerobic digestion, leading to methane fermentation. In the experiment, cattle manure was used, which came from the Przybroda farm belonging to the University of Life Sciences in Poznan. The aim of the study was to determine the biogas yield of slurry using the chemical and biological additive available on the Polish market. Mesophilic and thermophilic fermentation was used for the indication of the effectiveness of the employed fermentation process. The slurry was supplemented by a biological and chemical additive, i.e. effective microorganisms and – PRP, respectively. The experiment allowed to achieve a higher biogas yield during the use of effective microorganisms.

  7. Chemical and radiation environmental risk management at the crossroads: Case studies

    International Nuclear Information System (INIS)

    Tran, N.; Burke, T.; Locke, P.

    1999-01-01

    Although many of the major environmental risk management decisions we face today require the simultaneous evaluation and control of both radiological and chemical risks, the separation of radiation and chemical risk management persists along legal, regulatory, programmatic, training and professional practice levels. In June 1998, a panel of 40 chemical and radiation risk experts met at an interactive workshop entitled 'Addressing the Similarities and Differences in Chemical and Radiation Environmental Risk Management,' in Annapolis, Maryland to discuss several perspectives on harmonizing chemical and radiation risk management approaches. At the conclusion of the meeting, workshop participants recommended that case studies of clean-up sites at which radioactive materials and hazardous chemical risks were addressed, be developed to help educate participants in the harmonization dialogue about their counterpart's issues, stimulate discussion and sharpen issues in a way that they can be resolved. Several key risk management issues that were highlighted from the discussion at the Annapolis meeting are being evaluated in the case studies. They include: decision criteria, costs and public/stakeholder input. This paper presents these key issues and the approach taken in the case studies. (author)

  8. Radiation biology in Canada 1962-63

    International Nuclear Information System (INIS)

    Thacker, D.G.

    1963-02-01

    A survey of the research projects in radiation biology being carried out in Canada during the fiscal year 1962-63. The report includes the names of the investigators, their location, a brief description of the projects and information on the financial support being provided. A classification of the projects into areas of specific interest is also included. (author)

  9. Biological effects of radiation and health risks from exposure to low levels of ionizing radiation

    International Nuclear Information System (INIS)

    Kotian, Rahul P.; Kotian, Sahana Rahul; Sukumar, Suresh

    2013-01-01

    The very fact that ionizing radiation produces biological effects is known from many years. The first case of injury reported by Sir Roentgen was reported just after a few months after discovery of X-rays in 1895. As early as 1902, the first case of X-ray induced cancer was reported in the literature. Early human evidence of harmful effects as a result of exposure to radiation in large amounts existed in the 1920s and 1930s, based upon the experience of early radiologists, miners exposed to airborne radioactivity underground, persons working in the radium industry, and other special occupational groups. The long-term biological significance of smaller, repeated doses of radiation, however, was not widely appreciated until relatively recently, and most of our knowledge of the biological effects of radiation has been accumulated since World War II. The mechanisms that lead to adverse health effects after exposure to ionizing radiation are still not fully understood. Ionizing radiation has sufficient energy to change the structure of molecules, including DNA, within the cells of the body. Some of these molecular changes are so complex that it may be difficult for the body's repair mechanisms to mend them correctly. However, the evidence is that only a small fraction of such changes would be expected to result in cancer or other health effects. The most thoroughly studied individuals for the evaluation of health effects of ionizing radiation are the survivors of the Hiroshima and Nagasaki atomic bombings, a large population that includes all ages and both sexes.The Radiation Effects Research Foundation (RERF) in Japan has conducted followup studies on these survivors for more than 50 years. An important finding from these studies is that the occurrence of solid cancers increases in proportion to radiation dose. More than 60% of exposed survivors received a dose of radiation of less than 100 mSv (the definition of low dose used by the BEIR VII report). (author)

  10. Biological responses to low dose rate gamma radiation

    International Nuclear Information System (INIS)

    Magae, Junji; Ogata, Hiromitsu

    2003-01-01

    Linear non-threshold (LNT) theory is a basic theory for radioprotection. While LNT dose not consider irradiation time or dose-rate, biological responses to radiation are complex processes dependent on irradiation time as well as total dose. Moreover, experimental and epidemiological studies that can evaluate LNT at low dose/low dose-rate are not sufficiently accumulated. Here we analyzed quantitative relationship among dose, dose-rate and irradiation time using chromosomal breakage and proliferation inhibition of human cells as indicators of biological responses. We also acquired quantitative data at low doses that can evaluate adaptability of LNT with statistically sufficient accuracy. Our results demonstrate that biological responses at low dose-rate are remarkably affected by exposure time, and they are dependent on dose-rate rather than total dose in long-term irradiation. We also found that change of biological responses at low dose was not linearly correlated to dose. These results suggest that it is necessary for us to create a new model which sufficiently includes dose-rate effect and correctly fits of actual experimental and epidemiological results to evaluate risk of radiation at low dose/low dose-rate. (author)

  11. A radiobiological approach to cancer treatment. Possible chemical and physical agents modifying radiosensitivity in comparison with high LET radiations

    International Nuclear Information System (INIS)

    Sugahara, T.

    1982-01-01

    Biological characteristics of high LET radiations are summarized to be low oxygen enhancement ratio, high RBE, low repair and low cell cycle dependency of radiosensitivity. Various chemical modifiers of radiosensitivity and radiological effect of hyperthermia are classified into these four properties. It is evident that we have now various means to mimic high LET radiations as far as biological response is concerned though some of them are still in experimental stage. Among them, the means to cope with hypoxia and repair which are assumed to be the most important causes of radioresistance of human tumors are discussed in some detail. It is expected that through the present seminar we would have consensus to concentrate our effort of development for new modifying means available and useful in developing countries. (author)

  12. Chemical and biological effects of β-decay and inner shell ionization in biomolecules

    International Nuclear Information System (INIS)

    Stoecklin, G.

    1979-01-01

    Tritium and iodine-125, and the Auger effect either caused by the EC-decay of 125 I or by the inner shell vacancy created selectively by mono-energetic X-ray are reviewed in this paper. The specifically labelled precursors to bound 3 H large biomolecules were prepared by conventional syntheses, and then incorporated into the DNA of proliferating cells. The effects like DNA strand breaks or mutational changes are likely to be affected by the localization of the carbonium ions in biological molecules. In contrast to lethality, it was demonstrated that 3 H transmutation effect contributed to DNA strand breaks and played a key role in producing genetic effects. The decay of 3 H in uracil-5- 3 H in the DNA of E. coli was about 7 times as mutagenic as that in uracil-6- 3 H, and 500-fold greater in bacteriophage S13. Drastic chemical consequences are associated with the Auger effect occurring as a possible relaxation process whenever inner shell ionization is initiated. When the vacancy is filled by an electron from an outer shell, the bond energy difference between inner shell electron and outer shell electron is released either in the form of an X-ray fluorescence photon or it can be transmitted to another outer electron which is then ejected. The radioactive decay in specifically labelled biomolecules or the inner shell ionization in heavy constituent atoms caused by resonant X-ray are relevant to a) selective microsurgery in biological macromolecules for the correlation of biological and chemical functions, b) radiotoxicity estimation, and c) radiation therapy. (Yamashita, S.)

  13. Biological indicators for radiation absorbed dose: a review

    International Nuclear Information System (INIS)

    Paul, S.F.D.; Venkatachalam, P.; Jeevanram, R.K.

    1996-01-01

    Biological dosimetry has an important role to play in assessing the cumulative radiation exposure of persons working with radiation and also in estimating the true dose received during accidents involving external and internal exposure. Various biodosimetric methods have been tried to estimate radiation dose for the above purposes. Biodosimetric methods include cytogenetic, immunological and mutational assays. Each technique has certain advantages and disadvantages. We present here a review of each technique, the actual method used for detection of dose, the sensitivity of detection and its use in long term studies. (author)

  14. Radiation-resistant composite for biological shield of personnel

    Science.gov (United States)

    Barabash, D. E.; Barabash, A. D.; Potapov, Yu B.; Panfilov, D. V.; Perekalskiy, O. E.

    2017-10-01

    This article presents the results of theoretical and practical justification for the use of polymer concrete based on nonisocyanate polyurethanes in biological shield structures. We have identified the impact of ratio: polymer - radiation-resistant filling compound on the durability and protection properties of polymer concrete. The article expounds regression dependence of the change of basic properties of the aforementioned polymer concrete on the absorbed radiation dose rate. Synergy effect in attenuation of radioactivity release in case of conjoint use of hydrogenous polymer base and radiation-resistant powder is also addressed herein.

  15. Recommendations for sampling for prevention of hazards in civil defense. On analytics of chemical, biological and radioactive contaminations. Brief instruction for the CBRN (chemical, biological, radioactive, nuclear) sampling

    International Nuclear Information System (INIS)

    Bachmann, Udo; Biederbick, Walter; Derakshani, Nahid

    2010-01-01

    The recommendation for sampling for prevention of hazards in civil defense is describing the analytics of chemical, biological and radioactive contaminations and includes detail information on the sampling, protocol preparation and documentation procedures. The volume includes a separate brief instruction for the CBRN (chemical, biological, radioactive, nuclear) sampling.

  16. Wave equations for pulse propagation

    International Nuclear Information System (INIS)

    Shore, B.W.

    1987-01-01

    Theoretical discussions of the propagation of pulses of laser radiation through atomic or molecular vapor rely on a number of traditional approximations for idealizing the radiation and the molecules, and for quantifying their mutual interaction by various equations of propagation (for the radiation) and excitation (for the molecules). In treating short-pulse phenomena it is essential to consider coherent excitation phenomena of the sort that is manifest in Rabi oscillations of atomic or molecular populations. Such processes are not adequately treated by rate equations for excitation nor by rate equations for radiation. As part of a more comprehensive treatment of the coupled equations that describe propagation of short pulses, this memo presents background discussion of the equations that describe the field. This memo discusses the origin, in Maxwell's equations, of the wave equation used in the description of pulse propagation. It notes the separation into lamellar and solenoidal (or longitudinal and transverse) and positive and negative frequency parts. It mentions the possibility of separating the polarization field into linear and nonlinear parts, in order to define a susceptibility or index of refraction and, from these, a phase and group velocity. The memo discusses various ways of characterizing the polarization characteristics of plane waves, that is, of parameterizing a transverse unit vector, such as the Jones vector, the Stokes vector, and the Poincare sphere. It discusses the connection between macroscopically defined quantities, such as the intensity or, more generally, the Stokes parameters, and microscopic field amplitudes. The material presented here is a portion of a more extensive treatment of propagation to be presented separately. The equations presented here have been described in various books and articles. They are collected here as a summary and review of theory needed when treating pulse propagation

  17. Computing Radiative Transfer in a 3D Medium

    Science.gov (United States)

    Von Allmen, Paul; Lee, Seungwon

    2012-01-01

    A package of software computes the time-dependent propagation of a narrow laser beam in an arbitrary three- dimensional (3D) medium with absorption and scattering, using the transient-discrete-ordinates method and a direct integration method. Unlike prior software that utilizes a Monte Carlo method, this software enables simulation at very small signal-to-noise ratios. The ability to simulate propagation of a narrow laser beam in a 3D medium is an improvement over other discrete-ordinate software. Unlike other direct-integration software, this software is not limited to simulation of propagation of thermal radiation with broad angular spread in three dimensions or of a laser pulse with narrow angular spread in two dimensions. Uses for this software include (1) computing scattering of a pulsed laser beam on a material having given elastic scattering and absorption profiles, and (2) evaluating concepts for laser-based instruments for sensing oceanic turbulence and related measurements of oceanic mixed-layer depths. With suitable augmentation, this software could be used to compute radiative transfer in ultrasound imaging in biological tissues, radiative transfer in the upper Earth crust for oil exploration, and propagation of laser pulses in telecommunication applications.

  18. Wave propagation in elastic solids

    CERN Document Server

    Achenbach, Jan

    1984-01-01

    The propagation of mechanical disturbances in solids is of interest in many branches of the physical scienses and engineering. This book aims to present an account of the theory of wave propagation in elastic solids. The material is arranged to present an exposition of the basic concepts of mechanical wave propagation within a one-dimensional setting and a discussion of formal aspects of elastodynamic theory in three dimensions, followed by chapters expounding on typical wave propagation phenomena, such as radiation, reflection, refraction, propagation in waveguides, and diffraction. The treat

  19. Guidelines to improve airport preparedness against chemical and biological terrorism.

    Energy Technology Data Exchange (ETDEWEB)

    Edwards, Donna M.; Price, Phillip N. (Lawrence Berkeley National Laboratory, Berkeley, CA); Gordon, Susanna P.; Gadgil, Ashok (Lawrence Berkeley National Laboratory, Berkeley, CA)

    2005-05-01

    Guidelines to Improve Airport Preparedness Against Chemical and Biological Terrorism is a 100-page document that makes concrete recommendations on improving security and assessing vulnerable areas and helps its readers understand the nature of chemical and biological attacks. The report has been turned over to Airports Council International (ACI) and the American Association of Airport Executives (AAAE), two organizations that together represent the interests of thousands of airport personnel and facilities in the U.S. and around the world.

  20. Propagation of sound waves in ducts

    DEFF Research Database (Denmark)

    Jacobsen, Finn

    2000-01-01

    Plane wave propagation in ducts with rigid walls, radiation from ducts, classical four-pole theory for composite duct systems, and three-dimentional waves in wave guides of various cross-sectional shape are described.......Plane wave propagation in ducts with rigid walls, radiation from ducts, classical four-pole theory for composite duct systems, and three-dimentional waves in wave guides of various cross-sectional shape are described....

  1. The journal of medical chemical, biological and radiological defense, an update

    International Nuclear Information System (INIS)

    Price, B. B. S.; Peitersen, L.E.

    2009-01-01

    The Journal of Medical Chemical, Biological, and Radiological Defense (www.JMedCBR.org) is a peer-reviewed scientific online journal focusing on the biology, chemistry, physiology, toxicology and treatment of exposure to threat agents. JMedCBR provides a central international forum for the publication of current research and development information on medical chemical, biological and radiological defense, as well as training, doctrine, and problems related to chemical, biological and radiological casualties. JMedCBR is sponsored by the US Defense Threat Reduction Agency (DTRA) Chem-Bio Technologies Directorate as part of its scientific outreach program in chemical and biological defense solutions for the Department of Defense. In addition to scientific and medical research, JMedCBR hosts an archive of related papers from authors in the field. Although organized into annual issues, articles are published on the web continuously. The complete JMedCBR is published electronically and is made available to the scientific community free of charge. JMedCBR is committed to providing its readers with quality scientific information and critical analyses. All submissions are peer-reviewed by an editorial board of recognized and respected international scientists who represent expertise in different aspects of medical chemical, biological and radiological defense. Contributions to JMedCBR must be original works of the author(s) and must not have been previously published or simultaneously submitted to other publications. The author(s) transfer the copyright of articles published in JMedCBR to the journal. A copyright transfer form must accompany each manuscript submission. For more information on submitting to JMedCBR, see the Authors' Guide, available at http://www.jmedcbr.org/authorGuide.html.(author)

  2. [Decontamination of chemical and biological warfare agents].

    Science.gov (United States)

    Seto, Yasuo

    2009-01-01

    Chemical and biological warfare agents (CBWA's) are diverse in nature; volatile acute low-molecular-weight toxic compounds, chemical warfare agents (CWA's, gaseous choking and blood agents, volatile nerve gases and blister agents, nonvolatile vomit agents and lacrymators), biological toxins (nonvolatile low-molecular-weight toxins, proteinous toxins) and microbes (bacteria, viruses, rickettsiae). In the consequence management against chemical and biological terrorism, speedy decontamination of victims, facilities and equipment is required for the minimization of the damage. In the present situation, washing victims and contaminated materials with large volumes of water is the basic way, and additionally hypochlorite salt solution is used for decomposition of CWA's. However, it still remains unsolved how to dispose large volumes of waste water, and the decontamination reagents have serious limitation of high toxicity, despoiling nature against the environments, long finishing time and non-durability in effective decontamination. Namely, the existing decontamination system is not effective, nonspecifically affecting the surrounding non-target materials. Therefore, it is the urgent matter to build up the usable decontamination system surpassing the present technologies. The symposiast presents the on-going joint project of research and development of the novel decontamination system against CBWA's, in the purpose of realizing nontoxic, fast, specific, effective and economical terrorism on-site decontamination. The projects consists of (1) establishment of the decontamination evaluation methods and verification of the existing technologies and adaptation of bacterial organophosphorus hydrolase, (2) development of adsorptive elimination technologies using molecular recognition tools, and (4) development of deactivation technologies using photocatalysis.

  3. Radon and radiation biology of the lung

    International Nuclear Information System (INIS)

    Crameri, R.; Burkart, W.

    1989-01-01

    The main papers presented at the meeting dealt with the behaviour of radon and the indoor environment, radiation biology of the lung, lung dosis and the possible cancer risk caused by radon in homes, contamination of the room air. A series of special papers treated the radon problem in detail: sources and transport mechanisms of radon, geological aspects of the radon radiation burden in Switzerland, radon in homes, search for radon sources, and the Swiss radon-programme RAPROS. 67 figs., 13 tabs., 75 refs

  4. Modelling the propagation of terahertz radiation through a tissue simulating phantom

    International Nuclear Information System (INIS)

    Walker, Gillian C; Berry, Elizabeth; Smye, Stephen W; Zinov'ev, Nick N; Fitzgerald, Anthony J; Miles, Robert E; Chamberlain, Martyn; Smith, Michael A

    2004-01-01

    Terahertz (THz) frequency radiation, 0.1 THz to 20 THz, is being investigated for biomedical imaging applications following the introduction of pulsed THz sources that produce picosecond pulses and function at room temperature. Owing to the broadband nature of the radiation, spectral and temporal information is available from radiation that has interacted with a sample; this information is exploited in the development of biomedical imaging tools and sensors. In this work, models to aid interpretation of broadband THz spectra were developed and evaluated. THz radiation lies on the boundary between regions best considered using a deterministic electromagnetic approach and those better analysed using a stochastic approach incorporating quantum mechanical effects, so two computational models to simulate the propagation of THz radiation in an absorbing medium were compared. The first was a thin film analysis and the second a stochastic Monte Carlo model. The Cole-Cole model was used to predict the variation with frequency of the physical properties of the sample and scattering was neglected. The two models were compared with measurements from a highly absorbing water-based phantom. The Monte Carlo model gave a prediction closer to experiment over 0.1 to 3 THz. Knowledge of the frequency-dependent physical properties, including the scattering characteristics, of the absorbing media is necessary. The thin film model is computationally simple to implement but is restricted by the geometry of the sample it can describe. The Monte Carlo framework, despite being initially more complex, provides greater flexibility to investigate more complicated sample geometries

  5. Probes & Drugs portal: an interactive, open data resource for chemical biology

    Czech Academy of Sciences Publication Activity Database

    Škuta, Ctibor; Popr, M.; Muller, Tomáš; Jindřich, Jindřich; Kahle, Michal; Sedlák, David; Svozil, Daniel; Bartůněk, Petr

    2017-01-01

    Roč. 14, č. 8 (2017), s. 758-759 ISSN 1548-7091 R&D Projects: GA MŠk LO1220 Institutional support: RVO:68378050 Keywords : bioactive compound, ,, * chemical probe * chemical biology * portal Subject RIV: EB - Genetics ; Molecular Biology OBOR OECD: Computer sciences, information science, bioinformathics (hardware development to be 2.2, social aspect to be 5.8) Impact factor: 25.062, year: 2016

  6. WE-DE-202-00: Connecting Radiation Physics with Computational Biology

    International Nuclear Information System (INIS)

    2016-01-01

    Radiation therapy for the treatment of cancer has been established as a highly precise and effective way to eradicate a localized region of diseased tissue. To achieve further significant gains in the therapeutic ratio, we need to move towards biologically optimized treatment planning. To achieve this goal, we need to understand how the radiation-type dependent patterns of induced energy depositions within the cell (physics) connect via molecular, cellular and tissue reactions to treatment outcome such as tumor control and undesirable effects on normal tissue. Several computational biology approaches have been developed connecting physics to biology. Monte Carlo simulations are the most accurate method to calculate physical dose distributions at the nanometer scale, however simulations at the DNA scale are slow and repair processes are generally not simulated. Alternative models that rely on the random formation of individual DNA lesions within one or two turns of the DNA have been shown to reproduce the clusters of DNA lesions, including single strand breaks (SSBs), double strand breaks (DSBs) without the need for detailed track structure simulations. Efficient computational simulations of initial DNA damage induction facilitate computational modeling of DNA repair and other molecular and cellular processes. Mechanistic, multiscale models provide a useful conceptual framework to test biological hypotheses and help connect fundamental information about track structure and dosimetry at the sub-cellular level to dose-response effects on larger scales. In this symposium we will learn about the current state of the art of computational approaches estimating radiation damage at the cellular and sub-cellular scale. How can understanding the physics interactions at the DNA level be used to predict biological outcome? We will discuss if and how such calculations are relevant to advance our understanding of radiation damage and its repair, or, if the underlying biological

  7. WE-DE-202-00: Connecting Radiation Physics with Computational Biology

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2016-06-15

    Radiation therapy for the treatment of cancer has been established as a highly precise and effective way to eradicate a localized region of diseased tissue. To achieve further significant gains in the therapeutic ratio, we need to move towards biologically optimized treatment planning. To achieve this goal, we need to understand how the radiation-type dependent patterns of induced energy depositions within the cell (physics) connect via molecular, cellular and tissue reactions to treatment outcome such as tumor control and undesirable effects on normal tissue. Several computational biology approaches have been developed connecting physics to biology. Monte Carlo simulations are the most accurate method to calculate physical dose distributions at the nanometer scale, however simulations at the DNA scale are slow and repair processes are generally not simulated. Alternative models that rely on the random formation of individual DNA lesions within one or two turns of the DNA have been shown to reproduce the clusters of DNA lesions, including single strand breaks (SSBs), double strand breaks (DSBs) without the need for detailed track structure simulations. Efficient computational simulations of initial DNA damage induction facilitate computational modeling of DNA repair and other molecular and cellular processes. Mechanistic, multiscale models provide a useful conceptual framework to test biological hypotheses and help connect fundamental information about track structure and dosimetry at the sub-cellular level to dose-response effects on larger scales. In this symposium we will learn about the current state of the art of computational approaches estimating radiation damage at the cellular and sub-cellular scale. How can understanding the physics interactions at the DNA level be used to predict biological outcome? We will discuss if and how such calculations are relevant to advance our understanding of radiation damage and its repair, or, if the underlying biological

  8. Industrial applications of radiations

    International Nuclear Information System (INIS)

    Gallien, C.L.

    1988-01-01

    Radiation processing refers to the use of ionizing radiation to initiate chemical or biological changes in various materials as a substitute for conventional thermal or chemical processes. The method was inroduced in the industrial field 30 years ago and is now being widely used for numerous applications, among which industrial radiography, polymer modification, sterilization or decontamination, and food preservation. Both electron beam accelerators and gamma sources can be used, depending mainly of the amount of radiation and the penetration required. Radiation processing presents an increasing economical importance; in 1986 the market volume of ionized products ranged 3 billion $ [fr

  9. Enhancements in biologically effective ultraviolet radiation following volcanic eruptions

    Science.gov (United States)

    Vogelmann, A. M.; Ackerman, T. P.; Turco, R. P.

    1992-01-01

    A radiative transfer model is used to estimate the changes in biologically effective radiation (UV-BE) at the earth's surface produced by the El Chichon (1982) and Mount Pinatubo (1991) eruptions. It is found that in both cases surface intensity can increase because the effect of ozone depletion outweighs the increased scattering.

  10. Biological radiation effects

    International Nuclear Information System (INIS)

    Sejourne, Michele.

    1977-01-01

    This work examines ionizing radiations: what they are, where they come from, their actions and consequences, finally the norms and preventive measures necessary to avoid serious contamination, whether the individual or the population in general is involved. Man has always been exposed to natural irradiation, but owing to the growing use of ionizing radiations both in medicine and in industry, not to mention nuclear tests and their use as an argument of dissuasion, the irradiation of human beings is increasing daily. Radioactive contamination does remain latent, apart from acute cases, but this is where the danger lies since the consequences may not appear until long after the irradiation. Of all biological effects due to the action of radioelements the genetic risk is one of the most important, affecting the entire population and especially the generations to come. The risk of cancer and leukemia induction plays a substantial part also since a large number of people may be concerned, depending on the mode of contamination involved. All these long-term dangers do not of course exclude the various general or local effects to which the individual alone may be exposed and which sometimes constitute a threat to life. As a result the use of ionizing radiations must be limited and should only be involved if no other process can serve instead. The regulations governing radioelements must be stringent and their application strictly supervised for the better protection of man. This protection must be not only individual but also collective since pollution exists in air, water and land passes to plants and animals and finally reaches the last link in the food chain, man [fr

  11. The RBE of tritium-beta exposure for the induction of the adaptive response and apoptosis; cellular defense mechanisms against the biological effects of ionizing radiation

    International Nuclear Information System (INIS)

    Boreham, D.R.; Bahen, M.E.; Dolling, J-A.

    1997-01-01

    Adaption to radiation is one of a few biological responses that has been demonstrated to occur in mammalian cells exposed to doses of ionizing radiation in the occupational exposure range. The adaptive response has been well characterized in the yeast Saccharomyces cerevisiae, although the doses required to induce the response are higher than in mammalian cells. When yeast cells are primed with sublethal doses of gamma-radiation, they subsequently undergo an adaptive response and develop resistance to radiation, heat the chemical mutagens in a time and dose dependent manner. We have used this model system to assess the relative ability of tritium-beta radiation to induce the adaptive response the examined tritium-induced radiation resistance, thermal tolerance and suppression of mutation. The results show that sublethal priming doses of tritium caused yeast cells to develop resistance to radiation, heat, and a chemical mutagen MNNG. The magnitude and kinetics of the response, per unit dose, were the same for tritium and gamma-radiation. Therefore, the relative biological effectiveness (RBE) of tritium induction of the adaptive response was about 1.0. Apoptosis is a genetically programmed cell death or cell suicide. Cells damaged by radiation can be selectively removed from the population by apoptosis and therefore eliminated as a potential cancer risk to the organism. Since we have previously shown that apoptosis is a sensitive indicator of radiation damage in human lymphocytes exposed to low doses, we have used this endpoint to investigate the potency of tritium-beta radiation. Initially, tritium was compared to X-rays for relative effectiveness at inducing apoptosis. The results showed the lymphocytes irradiated in vitro with X-rays or tritium had similar levels of apoptosis per unit dose. Therefore the relative biology effectiveness of tritium for induction of apoptosis in human lymphocytes was also about 1. In the work presented here, we have demonstrated that

  12. Insect-gene-activity detection system for chemical and biological warfare agents and toxic industrial chemicals

    Science.gov (United States)

    Mackie, Ryan S.; Schilling, Amanda S.; Lopez, Arturo M.; Rayms-Keller, Alfredo

    2002-02-01

    Detection of multiple chemical and biological weapons (CBW) agents and/or complex mixtures of toxic industrial chemicals (TIC) is imperative for both the commercial and military sectors. In a military scenario, a multi-CBW attack would create confusion, thereby delaying decontamination and therapeutic efforts. In the commercial sector, polluted sites invariably contain a mixture of TIC. Novel detection systems capable of detecting CBW and TIC are sorely needed. While it may be impossible to build a detector capable of discriminating all the possible combinations of CBW, a detection system capable of statistically predicting the most likely composition of a given mixture is within the reach of current emerging technologies. Aquatic insect-gene activity may prove to be a sensitive, discriminating, and elegant paradigm for the detection of CBW and TIC. We propose to systematically establish the expression patterns of selected protein markers in insects exposed to specific mixtures of chemical and biological warfare agents to generate a library of biosignatures of exposure. The predicting capabilities of an operational library of biosignatures of exposures will allow the detection of emerging novel or genetically engineered agents, as well as complex mixtures of chemical and biological weapons agents. CBW and TIC are discussed in the context of war, terrorism, and pollution.

  13. Combined genetic effects of chemicals and radiation

    International Nuclear Information System (INIS)

    Kada, T.; Inoue, T.; Yokoiyama, A.; Russell, L.B.

    1979-01-01

    The interactions of chemicals and radiation are complex, and there may exist other unexpected patterns. The photodynamic induction of mutation by fluorescein dyes, and the radiosensitization with iodine compounds are classified as the interactions of chemicals and radiation outside cells. On the other hand, the antimutagenic effects of cobaltous chloride is concerned with the events taking place in the cells that had already been exposed to mutagenic agents. It is likely that the action of mutagenic agents is not direct, and that cellular functions, such as mutators or repair systems, are involved in the mutagenesis initiated by the agents. Such cellular functions can be affected by a second agent. In sexually reproducing organisms, two agents can also act on separate cells (male and female germ cells) which subsequently fuse. In mice, the experiments combining the radiation applied to one sex with the chemicals given to the other sex are only in early stages. Males were irradiated with X-ray (spermatozoa and spermatids sampled) and females (mature oocytes) were treated with caffeine. When the endpoint was dominant lethal, the level of X-ray effect induced in the male genome was independent of the caffeine treatment of the female. However, when the endpoint was sex-chromosome-loss, and a different strain of female was used, the caffeine potentiation was statistically significant at 5% level. (Yamashita, S.)

  14. Ultraviolet radiation and its biological effects

    International Nuclear Information System (INIS)

    Rames, J.; Bencko, V.

    1993-01-01

    In connexion with contamination of the atmosphere with freons, the interest is increasing in geophysical and health aspects of 'ozone holes' - the seasonal incidence of increased intensity of UV radiation. Its biological effects depend on the intensity of the radiation, the exposure time and the wavelength. There is a wide range of various sorts of damage, local as well as general. In addition to skin pigmentation and symptoms produced by an elevated histamine blood level, also changes are found which may have more serious and permanent consequences: changes in the number and structure of Langerhans islets, changes of the peripheral capillary walls, dimerization of pyrimidine and thymine in DNA. These changes demonstrably contribute to the development of skin malignancies. After exposure of the eye, changes in pigmentation are found, and depending on the dose, possibly also development of conjunctivitis or retinal damage. Recently the interaction of UV radiation with arsenic was investigated. On the other side, therapeutic effects of UV radiation combined with chemotherapy are used in dermatology, eg., for inhibition of contact sensitization. (author) 42 refs

  15. Track models and radiation chemical yields

    International Nuclear Information System (INIS)

    Chatterjee, A.; Magee, J.L.

    1987-01-01

    The authors are concerned only with systems in which single track effects dominate and radiation chemical yields are sums of yields for individual tracks. The authors know that the energy deposits of heavy particle tracks are composed of spurs along the particle trajectory (about one-half of the energy) and a more diffuse pattern composed of the tracks of knock-on electrons, called the penumbra (about one-half of the energy). The simplest way to introduce the concept of a unified track model for heavy particles is to consider the special case of the track of a heavy particle with an LET below 0.2-0.3eV/A, which in practice limits us to protons, deuterons, or particles with energy above 100 MeV per nucleon. At these LET values, to a good approximation, spurs formed by the main particle track can be considered to remain isolated throughout the radiation chemical reactions

  16. Radiation physics, biophysics, and radiation biology

    International Nuclear Information System (INIS)

    Hall, E.J.; Zaider, M.; Delegianis, M.J.

    1989-07-01

    An important event of the year was the designation of our Laboratory as a Center for Radiological Research by the Dean of the Faculty of Medicine and Vice-President for Health Sciences. Center status acknowledges the size and importance of the research efforts in this area, and allows a greater measure of independence in administrative matters. While the name has changed from a Laboratory to a Center within the Medical School, the mission and charge remain the same. The efforts of the Center are a multidisciplinary mix of physics, chemistry, and biology, mostly at a basic level, with the admixture of a small proportion of pragmatic or applied research in support of radiation protection or radiation therapy. About a quarter of our funding, mostly individual research awards, could be regarded as in direct support of radiotherapy, with the remainder (an NCI program project grant and DOE grants) being in support of research addressing more basic issues. An important effort currently underway concerns ab-initio calculations of the dielectric response function of condensed water. This investigation has received the coveted designation, ''Grand Challenge Project,'' awarded by DOE to research work which represents ''distinct advance on a major scientific or engineering problem that is broadly recognized as important within the mission of the Department.''

  17. Radiological equivalent of chemical pollutants

    International Nuclear Information System (INIS)

    Medina, V.O.

    1982-01-01

    The development of the peaceful uses of nuclear energy has caused continued effort toward public safety through radiation health protection measures and nuclear management practices. However, concern has not been focused on the development specifically in the operation of chemical pestrochemical industries as well as other industrial processes brought about by technological advancements. This article presents the comparison of the risk of radiation and chemicals. The methods used for comparing the risks of late effects of radiation and chemicals are considered at three levels. (a) as a frame of reference to give an impression of resolving power of biological tests; (b) as methods to quantify risks; (c) as instruments for an epidemiological survey of human populations. There are marked dissimilarities between chemicals and radiation and efforts to interpret chemical activity may not be achieved. Applicability of the concept of rad equivalence has many restrictions and as pointed out this approach is not an established one. (RTD)

  18. News: Synthetic biology leading to specialty chemicals ...

    Science.gov (United States)

    Synthetic biology can combine the disciplines of biology, engineering, and chemistry productively to form molecules of great scientific and commercial value. Recent advances in the new field are explored for their connection to new tools that have been used to elucidate production pathways to a wide variety of chemicals generated by microorganisms. The selection and enhancement of microbiological strains through the practice of strain engineering enables targets of design, construction, and optimization. This news column aspires to cover recent literature relating to the development and understanding of clean technology.

  19. Radiation chemical studies on the treatment of waste water

    International Nuclear Information System (INIS)

    Sakumoto, Akihisa; Miyata, Teijiro; Arai, Michimasa; Arai, Hidehiko

    1982-10-01

    The radiation induced reaction in aqueous solution was studied to develope the radiation treatment as a new technique for waste water and to elevate the effectiveness of radiation. The effectiveness of radiation was enhanced by combination of radiation induced reaction with conventional methods such as biological treatment and coagulation treatment. The synergistic effect of radiation and ozone was studied by using phenol and ethylene glycol. The chain reaction was observed in the radiation induced oxidation. The combination of radiation and ozone is considered to be one of the most useful method. In this report, the mechanism of each reaction and the applicability of the reaction to the treatment of waste water are discussed. (author)

  20. Development of radiation biological dosimetry

    International Nuclear Information System (INIS)

    Cho, Chul Koo; Kim, Tae Hwan; Lee, Yun Sil; Son, Young Sook; Kim, Soo Kwan; Jang, Won Suk; Le, Sun Joo; Jee, Young Heun; Jung, Woo Jung

    1999-04-01

    Up until now, only a few methods have been developed for radiation biological dosimetry such as conventional chromosome aberration and micronucleus in peripheral blood cell. However, because these methods not only can be estimated by the expert, but also have a little limitation due to need high technique and many times in the case of radiation accident, it is very difficult to evaluate the absorbed dose of victims. Therefore, we should develop effective, easy, simple and rapid biodosimetry and its guideline (triage) to be able to be treated the victims as fast as possible. We established the premature chromosome condensation assay and apoptotic fragment assay which was the significant relationship between dose and cell damages to evaluate the irradiation dose as correct and rapid as possible using lymphocytes and crypt cells, and compared with conventional chromosome aberration assay and micronuclei assay

  1. Development of radiation biological dosimetry

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Chul Koo; Kim, Tae Hwan; Lee, Yun Sil; Son, Young Sook; Kim, Soo Kwan; Jang, Won Suk; Le, Sun Joo; Jee, Young Heun; Jung, Woo Jung

    1999-04-01

    Up until now, only a few methods have been developed for radiation biological dosimetry such as conventional chromosome aberration and micronucleus in peripheral blood cell. However, because these methods not only can be estimated by the expert, but also have a little limitation due to need high technique and many times in the case of radiation accident, it is very difficult to evaluate the absorbed dose of victims. Therefore, we should develop effective, easy, simple and rapid biodosimetry and its guideline (triage) to be able to be treated the victims as fast as possible. We established the premature chromosome condensation assay and apoptotic fragment assay which was the significant relationship between dose and cell damages to evaluate the irradiation dose as correct and rapid as possible using lymphocytes and crypt cells, and compared with conventional chromosome aberration assay and micronuclei assay.

  2. Ductile crack initiation and propagation assessed via in situ synchrotron radiation-computed laminography

    International Nuclear Information System (INIS)

    Morgeneyer, T.F.; Helfen, L.; Sinclair, I.; Proudhon, H.; Xu, F.; Baumbach, T.

    2011-01-01

    Ductile crack initiation and propagation within a naturally aged aluminium alloy sheet has been observed in situ via synchrotron radiation-computed laminography, a technique specifically adapted to three-dimensional imaging of thin objects that are laterally extended. Voids and intermetallic particles, and their subsequent evolution during ductile crack extension at different associated levels of stress triaxiality, were clearly observed within fracture coupons of a reasonable engineering length-scale, overcoming the conventional sample size limitation of computed tomography at high resolutions.

  3. International Journal of Biological and Chemical Sciences: Editorial ...

    African Journals Online (AJOL)

    The International Journal of Biological and Chemical Sciences (IJBCS) is a journal ... IJBCS publishes original research papers, critical up-to-date and concise ... Department of Biomedical Sciences, College of Osteopathic Medicine, Ohio ...

  4. Environmental radiation: basic principles, biological facts, potential risks

    International Nuclear Information System (INIS)

    Rodemann, H.P.

    2000-01-01

    This book describes the complex processes that underlie the effects of different types of radiation at the cellular, organ and organismic level. Technical terms central to the subject matter are printed in italicize and explained in a glossary along with all physical quantities and dimensional units referred to. Through a systematic presentation of various aspects of the effects of environmental radiation on humans the author has endeavoured to make it clear that any discussion on potential health hazards must be conducted specific to the type of radiation in question. Furthermore, to study these issues meaningfully one must have a knowledge of the scientific basis of interactions between the various types of radiation and biological systems and be able to assess the relative impact of environmental radiation compared with other environmental health hazards

  5. Biological monitors for low levels of ionising radiation

    International Nuclear Information System (INIS)

    Mohankumar, M.N.; Jeevanram, R.K.

    1995-01-01

    The biological effects of high doses of ionising radiation are well understood and the methods of measurement of these doses well established. However the effects due to extremely low doses remain by and large uncertain. This is because of the fact that at such low doses no gross symptoms are seen. In fact, at these levels the occurrence of double strand breaks leading to the formation of chromosomal aberrations like dicentrics is rare and chances of mutation due to base damage are negligible. Hence neither chromosomal aberration studies nor mutational assays are useful for detecting doses of the order of a few milligray. Results of exhaustive work done by various laboratories indicate that below 20 mGy the chromosomal aberration technique based on scoring of dicentrics cannot distinguish between a linear or a threshold model. However indirect methods like unscheduled DNA synthesis (UDS) and sister chromatid exchanges (SCEs) appear to be promising for the detection of radiation exposures due to low levels of radiation. This report reviews the available literature on the biological effects of low levels of ionising radiation and highlights the merits and demerits of the various methods employed in the measurement of UDS and SCE. The phenomenon of radio-adaptive response (RAR) and its relation to DNA repair is also discussed. (author)

  6. Radiation-chemical alkylation of olefines with adamantane

    International Nuclear Information System (INIS)

    Podkhalyuzin, A.T.; Vikulin, V.V.; Morozov, V.A.; Nazarova, M.P.; Vereshchinskii, I.V.

    1977-01-01

    Radiation-chemical alkylation of C 2 to C 4 olefines with adamantane was studied in gas phase at temperatures 270 to 430 0 C. The main reaction product is monoalkyladamantane. The reaction proceeds by a free radical chain mechanism. The effective activation energy is of the order of 8 to 10 kcal/mole. Thermal alkylation was carried out for comparison and the contribution of the thermal component to the radiation-thermal process was estimated. Liquid phase alkylation of hexafluoropropylene with adamantane was studied in the presence of solvents. Under various conditions mono- and di-substituted adamantanes are produced containing fluorine in end groups. These compounds were converted to corresponding fluoroalkenyladamantanes by dehydrofluorination. The kinetic parameters were calculated and physical-chemical data concerning some of the resulting products were determined. (author)

  7. Biological Bases for Radiation Adaptive Responses in the Lung

    Energy Technology Data Exchange (ETDEWEB)

    Scott, Bobby R. [Lovelace Biomedical and Environmental Research Inst., Albuquerque, NM (United States); Lin, Yong [Lovelace Biomedical and Environmental Research Inst., Albuquerque, NM (United States); Wilder, Julie [Lovelace Biomedical and Environmental Research Inst., Albuquerque, NM (United States); Belinsky, Steven [Lovelace Biomedical and Environmental Research Inst., Albuquerque, NM (United States)

    2015-03-01

    Our main research objective was to determine the biological bases for low-dose, radiation-induced adaptive responses in the lung, and use the knowledge gained to produce an improved risk model for radiation-induced lung cancer that accounts for activated natural protection, genetic influences, and the role of epigenetic regulation (epiregulation). Currently, low-dose radiation risk assessment is based on the linear-no-threshold hypothesis, which now is known to be unsupported by a large volume of data.

  8. Application of synthetic biology for production of chemicals in yeast Saccharomyces cerevisiae

    DEFF Research Database (Denmark)

    Borodina, Irina; Li, Mingji

    2015-01-01

    Synthetic biology and metabolic engineering enable generation of novel cell factories that efficiently convert renewable feedstocks into biofuels, bulk, and fine chemicals, thus creating the basis for biosustainable economy independent on fossil resources. While over a hundred proof...... biology has the potential to bring down this cost by improving our ability to predictably engineer biological systems. This review highlights synthetic biology applications for design, assembly, and optimization of non-native biochemical pathways in baker's yeast Saccharomyces cerevisiae. We describe......-of-concept chemicals have been made in yeast, only a very small fraction of those has reached commercial-scale production so far. The limiting factor is the high research cost associated with the development of a robust cell factory that can produce the desired chemical at high titer, rate, and yield. Synthetic...

  9. Relative biological efficiency of 592 MeV protons. Analysis of the biological effect of secondary radiation

    International Nuclear Information System (INIS)

    Legeay, G.; Baarli, J.

    1968-01-01

    The relative biological efficiency (RBE) of high energy protons is of importance because of their effects in the field of radioprotection around large accelerators and during space-flights. The nature of the interactions between 592 MeV protons and biological tissues makes it necessary to take into consideration the contribution of secondary radiation to the biological effect. Since it is not possible to obtain from a synchrotron a beam having a sufficiently large cross-section to irradiate large animals, one has to resort to certain devices concerning the mode of exposure when small laboratory animals are used. By irradiating rats individually and in groups, and by using the lethal test as a function of time, the authors show that the value of the RBE is different for animals of the same species having the same biological parameters. Thus there appears an increase in the biological effect due to secondary radiation produced in nuclear cascades which develop in a large volume, for example that of a human being. (author) [fr

  10. Linking neuroethology to the chemical biology of natural products

    DEFF Research Database (Denmark)

    Olivera, Baldomero M.; Raghuraman, Shrinivasan; Schmidt, Eric W.

    2017-01-01

    From a biological perspective, a natural product can be defined as a compound evolved by an organism for chemical interactions with another organism including prey, predator, competitor, pathogen, symbiont or host. Natural products hold tremendous potential as drug leads and have been extensively...... a better understanding of the evolution, biology and biochemistry of natural products will facilitate both neuroscience and the potential for drug leads. The larger goal is to establish a new sub-discipline in the broader field of neuroethology that we refer to as “Chemical Neuroethology”, linking...... the substantial work carried out by chemists on natural products with accelerating advances in neuroethology....

  11. Biological and chemical removal of Cr(VI) from waste water: cost and benefit analysis.

    Science.gov (United States)

    Demir, Aynur; Arisoy, Münevver

    2007-08-17

    The objective of the present study is cost and benefit analysis of biological and chemical removal of hexavalent chromium [Cr(VI)] ions. Cost and benefit analysis were done with refer to two separate studies on removal of Cr(VI), one of heavy metals with a crucial role concerning increase in environmental pollution and disturbance of ecological balance, through biological adsorption and chemical ion-exchange. Methods of biological and chemical removal were compared with regard to their cost and percentage in chrome removal. According to the result of the comparison, cost per unit in chemical removal was calculated 0.24 euros and the ratio of chrome removal was 99.68%, whereas those of biological removal were 0.14 and 59.3% euros. Therefore, it was seen that cost per unit in chemical removal and chrome removal ratio were higher than those of biological removal method. In the current study where chrome removal is seen as immeasurable benefit in terms of human health and the environment, percentages of chrome removal were taken as measurable benefit and cost per unit of the chemicals as measurable cost.

  12. Effects of Ionizing Radiation on Biological Molecules—Mechanisms of Damage and Emerging Methods of Detection

    Science.gov (United States)

    Reisz, Julie A.; Bansal, Nidhi; Qian, Jiang; Zhao, Weiling

    2014-01-01

    Abstract Significance: The detrimental effects of ionizing radiation (IR) involve a highly orchestrated series of events that are amplified by endogenous signaling and culminating in oxidative damage to DNA, lipids, proteins, and many metabolites. Despite the global impact of IR, the molecular mechanisms underlying tissue damage reveal that many biomolecules are chemoselectively modified by IR. Recent Advances: The development of high-throughput “omics” technologies for mapping DNA and protein modifications have revolutionized the study of IR effects on biological systems. Studies in cells, tissues, and biological fluids are used to identify molecular features or biomarkers of IR exposure and response and the molecular mechanisms that regulate their expression or synthesis. Critical Issues: In this review, chemical mechanisms are described for IR-induced modifications of biomolecules along with methods for their detection. Included with the detection methods are crucial experimental considerations and caveats for their use. Additional factors critical to the cellular response to radiation, including alterations in protein expression, metabolomics, and epigenetic factors, are also discussed. Future Directions: Throughout the review, the synergy of combined “omics” technologies such as genomics and epigenomics, proteomics, and metabolomics is highlighted. These are anticipated to lead to new hypotheses to understand IR effects on biological systems and improve IR-based therapies. Antioxid. Redox Signal. 21: 260–292. PMID:24382094

  13. Radiation physics, biophysics and radiation biology. Progress report, December 1, 1984-November 30, 1985

    International Nuclear Information System (INIS)

    Rossi, H.H.

    1985-07-01

    This is the annual progress report for the Radiological Research Laboratory, Department of Radiology, Columbia University. The report consists of 17 individual reports plus an overall summary. Reports survey research results in neutron dosimetry, microdosimetry of electron beams and x-radiation, development of theoretical models for biological radiation effects and induction of oncogenic transformations. Individual abstracts were also prepared for each paper

  14. Assessment of radiation safety awareness and attitude toward biological effect of radiation for employees in nuclear workplace

    International Nuclear Information System (INIS)

    Youngchuay, U.; Jetawattana, S.; Toeypho, V.; Eso, J.

    2016-01-01

    This study demonstrated a potential relevance of data pertaining to the interaction of awareness in radiation biology and their attitude towards radiation hazards. The obtained information is useful in ascertaining the effectiveness of the ongoing radiation safety program and will be further used to determine the relationships between the radiation effective dose and cytogenetic approach in these groups of workers. (author)

  15. The late biological effects of ionizing radiation

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1978-06-15

    Full text: The principal objective of the symposium was to review the current status of understanding of the late biological effects of ionizing radiation from external and internal sources. A second objective was to critically evaluate information obtained from epidemiological studies of human population groups as well as from animal experimentation in order to provide a solid scientific basis upon which problems of current concern, such as radiation protection standards and risk-benefit analysis, could be deliberated. Eighty-one papers were presented in 10 sessions which covered epidemiological studies of late effects in human populations exposed to internal and/or external ionizing radiation; quantitative and qualitative data from animal experimentation of late effects; methodological problems and modern approaches; factors influencing susceptibility or expression of late radiation injury; comparative evaluation of late effects induced by radiation and other environmental pollutants, and problems of risk assessment. In addition, there were two evening sessions for free discussion of problems of interpreting animal data, and of the epidemiological studies of occupationally exposed populations. Reports on atomic bomb survivors showed that these epidemiological studies are providing dependable data, such as dose-related excess infant mortality. The reports also revealed the need for consensus in the method employed in the interpretation of data. That was also the case with studies on occupationally exposed populations at Hanford plant, where disparate results were presented on radiation-induced neoplasia among radiation workers. These data are, however, considered not so significant in relative terms when compared to risks involved in other industries. It was recommended that national registry systems for the dosimetry and medical records of radiation workers be established and co-ordinated internationally in order to facilitate reliable epidemiological

  16. Space radiation-induced bystander effect: kinetics of biologic responses, mechanisms, and significance of secondary radiations

    International Nuclear Information System (INIS)

    Gonon, Geraldine

    2011-01-01

    Widespread evidence indicates that exposure of cell cultures to a particles results in significant biological changes in both the irradiated and non-irradiated bystander cells in the population. The induction of non-targeted biological responses in cell cultures exposed to low fluences of high charge (Z) and high energy (E) particles is relevant to estimates of the health risks of space radiation and to radiotherapy. Here, we investigated the mechanisms underlying the induction of stressful effects in confluent normal human fibroblast cultures exposed to low fluences of 1000 MeV/u iron ions (linear energy transfer (LET) 151 keV/μm), 600 MeV/u silicon ions (LET 50 keV/μm) or 290 MeV/u carbon ions (LET 13 keV/μm). We compared the results with those obtained in cell cultures exposed, in parallel, to low fluences of 0.92 MeV/u a particles (LET 109 keV/μm). Induction of DNA damage, changes in gene expression, protein carbonylation and lipid peroxidation during 24 h after exposure of confluent cultures to mean doses as low as 0.2 cGy of iron or silicon ions strongly supported the propagation of stressful effects from irradiated to bystander cells. At a mean dose of 0.2 cGy, only 1 and 3 % of the cells would be targeted through the nucleus by an iron or silicon ion, respectively. Within 24 h post-irradiation, immunoblot analyses revealed significant increases in the levels of phospho-TP53 (serine 15), p21Waf1 (also known as CDKN1A), HDM2, phospho-ERK1/2, protein carbonylation and lipid peroxidation. The magnitude of the responses suggested participation of non-targeted cells in the response. Furthermore, when the irradiated cell populations were subcultured in fresh medium shortly after irradiation, greater than expected increases in the levels of these markers were also observed during 24 h. Together, the results imply a rapidly propagated and persistent bystander effect. In situ analyses in confluent cultures showed 53BP1 foci formation, a marker of DNA damage, in

  17. The use of biologically based cancer risk models in radiation epidemiology

    International Nuclear Information System (INIS)

    Krewski, D.; Zielinski, J.M.; Hazelton, W.D.; Garner, M.J.; Moolgavkar, S.H.

    2003-01-01

    Biologically based risk projection models for radiation carcinogenesis seek to describe the fundamental biological processes involved in neoplastic transformation of somatic cells into malignant cancer cells. A validated biologically based model, whose parameters have a direct biological interpretation, can also be used to extrapolate cancer risks to different exposure conditions with some confidence. In this article, biologically based models for radiation carcinogenesis, including the two-stage clonal expansion (TSCE) model and its extensions, are reviewed. The biological and mathematical bases for such models are described, and the implications of key model parameters for cancer risk assessment examined. Specific applications of versions of the TSCE model to important epidemiologic datasets are discussed, including the Colorado uranium miners' cohort; a cohort of Chinese tin miners; the lifespan cohort of atomic bomb survivors in Hiroshima and Nagasaki; and a cohort of over 200,000 workers included in the National Dose Registry (NDR) of Canada. (author)

  18. Notions of radiation chemistry in biological systems

    International Nuclear Information System (INIS)

    Mastro, N.L. del.

    1989-10-01

    The present paper examines some aspects of the direct and indirect biological radiation effects: pair formation, free radicals, superoxide ion, hydrogen peroxide, hydroxyl radical, oxygen singlet together with the endogen radioprotector mechanisms of organisms and the ways in which an improved radioresistance of biochemical systems can be achieved. (author) [pt

  19. Natural radiation, nuclear wastes and chemical pollutants

    International Nuclear Information System (INIS)

    Christensen, T.; Ehdwall, H.; Stranden, E.

    1990-01-01

    Doses from natural radiation to the population in the Nordic Countries are summarized and man made modifications of the natural radiation environment are discussed. An account is given of the radiological consequences of energy conservation by reduced ventilation. Risks from possible future releases of radioactivity from final repositories of spent nuclear fuel are compared to the risks from present natural radioactivity in the environment. The possibilities for comparison between chemical and radiological risks are discussed. (author) 13 refs

  20. The high pH chemical and radiation compatibility of various liner materials

    International Nuclear Information System (INIS)

    Whyatt, G.A.; Farnsworth, R.K.

    1990-01-01

    This paper reports on a flexible membrane liner that has been proposed to line a concrete vault in which liquid low-level radioactive waste will be solidified. High-density polyethylene (HDPE) and polypropylene liners were tested at the Pacific Northwest Laboratory in an EPA method 9090 format to determine their chemical compatibility with the waste. Radiation effects were also investigated. The liners were immersed in a highly caustic (pH>14), primarily inorganic solution at 90 degrees C. The liners were subjected to radiation doses up to 38.9 Mrad, which was the expected dose the liner would receive over a 30-year life inside the vault. Recent changes have placed the liner outside the vault. The acceptance criteria for judging the compatibility of the liner with radiation would be different that those used for judging chemical compatibility. The radiation damage over the life of the liner can be simulated in a short-term test. Both HDPE and polypropylene liners were judged to be acceptable from a chemical and radiation standpoint when placed outside of the vault, while several other liners were not compatible. Radiation did not have a significant effect on chemical degradation rates

  1. The high pH chemical and radiation compatibility of various liner materials

    International Nuclear Information System (INIS)

    Whyatt, G.; Farnsworth, R.

    1990-01-01

    A flexible membrane liner has been proposed to line a concrete vault in which liquid low-level radioactive waste will be solidified. High-density polyethylene (HDPE) and polypropylene liners were tested at the Pacific Northwest Laboratory in an EPA method 9090 format to determine their chemical compatibility with the waste. Radiation effects were also investigated. The liners were immersed in a highly caustic (pH>14), primarily inorganic solution at 90 degrees C. The liners were subjected to radiation doses up to 38.9 Mrad, which was the expected dose the liner would receive over a 30-year life inside the vault. Recent changes have placed the liner outside the vault. The acceptance criteria for judging the compatibility of the liner with radiation should be different than those used for judging chemical compatibility. The radiation damage over the life of the liner can be simulated in a short-term test. Both HDPE and polypropylene liners were judged to be acceptable from a chemical and radiation standpoint when placed outside of the vault, while several other liners were not compatible. Radiation did not have a significant effect on chemical degradation rates

  2. Fabrication of radiation sources for educational purposes from chemical fertilizers using compressing and forming method

    International Nuclear Information System (INIS)

    Kawano, Takao

    2008-01-01

    Chemical fertilizers contain potassium, which is composed of a small amount of naturally occurring potassium-40. The potassium-40 radionuclide emits beta and gamma radiation. Three brands of chemical fertilizer were used to fabricate disk-shaped radiation sources and the fabricated radiation sources were examined for applicability to an educational radiation course. In the examination, tests to determine dependence of count rate on distance, shielding thickness, and shielding materials were conducted using the radiation sources. Results showed that radiation sources fabricated from the three brands of chemical fertilizer were equivalent for explaining radiation characteristics, particularly those related to the dependence of radiation strength on distance and shielding thickness. The relation between shielding effect and mass density can be explained qualitatively. Thus, chemical fertilizer radiation sources can be a useful teaching aid for educational courses to better promote understanding of radiation characteristics and the principles of radiation protection. (author)

  3. PERMANENCE OF BIOLOGICAL AND CHEMICAL WARFARE AGENTS IN MUNICIPAL SOLID WASTE LANDFILL LEACHATES

    Science.gov (United States)

    The objective of this work is to permit EPA/ORD's National Homeland Security Research Center (NHSRC) and Edgewood Chemical Biological Center to collaborate together to test the permanence of biological and chemical warfare agents in municipal solid waste landfills. Research into ...

  4. Radioprotection, biological effects of the radiations and security in the handling of radioactive material

    CERN Document Server

    Teran, M

    2000-01-01

    The development of the philosophy of the radioprotection is dependent on the understanding of the effects of the radiation in the man. Behind the fact that the radiation is able to produce biological damages there are certain factors with regard to the biological effects of the radiations that determine the boarding of the radioprotection topics.

  5. Mass spectrometry in identification of ecotoxicants including chemical and biological warfare agents

    International Nuclear Information System (INIS)

    Lebedev, Albert T.

    2005-01-01

    Mass spectrometry is a unique tool to detect and identify trace levels of organic and bioorganic compounds as well as microorganisms in the environment. The range of potential chemical warfare (CW) and biological warfare (BW) agents is very broad. An important advantage of mass spectrometry over other techniques involves potential for full spectrum detection of chemical and biological agents including mid-spectrum materials (i.e. bioactive peptides, toxins, etc.) for which biological approaches are inadequate. Being very fast (seconds and minutes), extremely sensitive (zeptomoles 10 -21 ), and informative (detailed qualitative and quantitative composition of mixtures containing hundreds of chemicals), mass spectrometry is a principal analytical tool at the sites of destruction of CW. Due to its unique features, mass spectrometry is applied not only for the detection of CW agents, but for the analysis of products of metabolism and degradation of these agents in organisms or environment as well. The present paper deals with some examples of successful application of mass spectrometry for the analyses of ecotoxicants, chemical warfare agents, explosives, and microorganisms including biology warfare agents

  6. The role of ionizing radiation in biological control of agricultural pests

    International Nuclear Information System (INIS)

    Mansour, M.

    2011-01-01

    Although the commercial biological control industry is growing, it still represents only a small portion of the international market of pest control sales (about 3%). This low ratio is due to several factors including high cost of production of biological control agents and technical and regulatory difficulties that complicate the shipping procedures and create trade barriers. This article summarizes the role of ionizing radiation in supporting the use of biological control agents in insect pest control and concentrates on its role in the production, transport, distribution, and release of parasites and predators and the advantages that ionizing radiation can offer, in comparison with traditional techniques. (author)

  7. Biological impact of high-dose and dose-rate radiation exposure

    International Nuclear Information System (INIS)

    Maliev, V.; Popov, D.; Jones, J.; Gonda, S.; Prasad, K.; Viliam, C.; Haase, G.; Kirchin, V.; Rachael, C.

    2006-01-01

    Experimental anti-radiation vaccine is a power tool of immune - prophylaxis of the acute radiation disease. Existing principles of treatment of the acute radiation dis ease are based on a correction of developing patho-physiological and biochemical processes within the first days after irradiation. Protection from radiation is built on the general principles of immunology and has two main forms - active and passive immunization. Active immunization by the essential radiation toxins of specific radiation determinant (S.D.R.) group allows significantly reduce the lethality and increase duration of life among animals that are irradiated by lethal and sub-lethal doses of gamma radiation.The radiation toxins of S.D.R. group have antigenic properties that are specific for different forms of acute radiation disease. Development of the specific and active immune reaction after intramuscular injection of radiation toxins allows optimize a manifestation of a clinical picture and stabilize laboratory parameters of the acute radiation syndromes. Passive immunization by the anti-radiation serum or preparations of immune-globulins gives a manifestation of the radioprotection effects immediately after this kind of preparation are injected into organisms of mammals. Providing passive immunization by preparations of anti-radiations immune-globulins is possible in different periods of time after radiation. Providing active immunization by preparations of S.D.R. group is possible only to achieve a prophylaxis goal and form the protection effects that start to work in 18 - 35 days after an injection of biological active S.D.R. substance has been administrated. However active and passive immunizations by essential anti-radiation toxins and preparations of gamma-globulins extracted from a hyper-immune serum of a horse have significantly different medical prescriptions for application and depend on many factors like a type of radiation, a power of radiation, absorption doses, a time of

  8. Biological impact of high-dose and dose-rate radiation exposure

    Energy Technology Data Exchange (ETDEWEB)

    Maliev, V.; Popov, D. [Russian Academy of Science, Vladicaucas (Russian Federation); Jones, J.; Gonda, S. [NASA -Johnson Space Center, Houston (United States); Prasad, K.; Viliam, C.; Haase, G. [Antioxida nt Research Institute, Premier Micronutrient Corporation, Novato (United States); Kirchin, V. [Moscow State Veterinary and Biotechnology Acade my, Moscow (Russian Federation); Rachael, C. [University Space Research Association, Colorado (United States)

    2006-07-01

    Experimental anti-radiation vaccine is a power tool of immune - prophylaxis of the acute radiation disease. Existing principles of treatment of the acute radiation dis ease are based on a correction of developing patho-physiological and biochemical processes within the first days after irradiation. Protection from radiation is built on the general principles of immunology and has two main forms - active and passive immunization. Active immunization by the essential radiation toxins of specific radiation determinant (S.D.R.) group allows significantly reduce the lethality and increase duration of life among animals that are irradiated by lethal and sub-lethal doses of gamma radiation.The radiation toxins of S.D.R. group have antigenic properties that are specific for different forms of acute radiation disease. Development of the specific and active immune reaction after intramuscular injection of radiation toxins allows optimize a manifestation of a clinical picture and stabilize laboratory parameters of the acute radiation syndromes. Passive immunization by the anti-radiation serum or preparations of immune-globulins gives a manifestation of the radioprotection effects immediately after this kind of preparation are injected into organisms of mammals. Providing passive immunization by preparations of anti-radiations immune-globulins is possible in different periods of time after radiation. Providing active immunization by preparations of S.D.R. group is possible only to achieve a prophylaxis goal and form the protection effects that start to work in 18 - 35 days after an injection of biological active S.D.R. substance has been administrated. However active and passive immunizations by essential anti-radiation toxins and preparations of gamma-globulins extracted from a hyper-immune serum of a horse have significantly different medical prescriptions for application and depend on many factors like a type of radiation, a power of radiation, absorption doses, a time of

  9. Comparative efficiency of chemical and radiation mutagens on two Cicer arietinum Rhizobial strains

    Energy Technology Data Exchange (ETDEWEB)

    Khare, A K; Shinde, D A; Nayak, M L [Jawaharlal Nehru Krishi Vishwa Vidyalaya, Indore (India)

    1982-03-01

    A comparison of efficacy due to chemical and radiation mutagens on morphology, nutritional totipotence and symbiotic character of two Cicer arietinum rhizobia has been made. The mutants produced as a result of radiations (gamma and UV rays) differed from parents in that, the mutant colony size was bigger and gelatinase activity was higher. The mutants were not deficient nutritionally, had wider host range and the size and number of nodules produced were higher. Radiation mutagenic effects were more pronounced than chemical mutagens. The mutants derived from chemicals were not as efficient as radiation mutants although they were better than parents in total nodulation.

  10. Study on the Chinese traditional drugs' sterilization and disinfestation by radiation and their biological effects

    International Nuclear Information System (INIS)

    Ma Shouxiang; Yang Ruikun; Liu Desheng

    1987-01-01

    The study of the sterilization and disinfestation by 60 Co γ-radiation and their biological effects on tuber of elevated gastrodia, Chinese angelica and Dangshen have been carried out. The experimental results show that optimal dose was 2 x 10 5 - 4 x 10 5 rad to kill insect in the three Chinese traditional drugs. The results also show that the content of the chemical composition of irradiated group is similar to control group under 6 x 10 5 rad. The thin-layer chromatography colour-maculae are almost the same. They have the same Rf exponent

  11. Biological monitors for low levels of ionising radiation

    Energy Technology Data Exchange (ETDEWEB)

    Mohankumar, M N; Jeevanram, R K [Safety Research and Health Physics Group, Indira Gandhi Centre for Atomic Research, Kalpakkam (India)

    1996-12-31

    The biological effects of high doses of ionising radiation are well understood and the methods of measurement of these doses well established. However the effects due to extremely low doses remain by and large uncertain. This is because of the fact that at such low doses no gross symptoms are seen. In fact, at these levels the occurrence of double strand breaks leading to the formation of chromosomal aberrations like dicentrics is rare and chances of mutation due to base damage are negligible. Hence neither chromosomal aberration studies nor mutational assays are useful for detecting doses of the order of a few milligray. Results of exhaustive work done by various laboratories indicate that below 20 mGy the chromosomal aberration technique based on scoring of dicentrics cannot distinguish between a linear or a threshold model. However indirect methods like unscheduled DNA synthesis (UDS) and sister chromatid exchanges (SCEs) appear to be promising for the detection of radiation exposures due to low levels of radiation. This report reviews the available literature on the biological effects of low levels of ionising radiation and highlights the merits and demerits of the various methods employed in the measurement of UDS and SCE. The phenomenon of radio-adaptive response (RAR) and its relation to DNA repair is also discussed. (author). 98 refs., 11 figs., 4 tabs.

  12. A framework for modeling information propagation of biological systems at critical states.

    Science.gov (United States)

    Hu, Feng; Yang, Fang

    2016-03-01

    We explore the dynamics of information propagation at the critical state of a biologically inspired system by an individual-based computer model. "Quorum response", a type of social interaction which has been recognized taxonomically in animal groups, is applied as the sole interaction rule among individuals. In the model, we assume a truncated Gaussian distribution to depict the distribution of the individuals' vigilance level. Each individual can assume either a naïve state or an alarmed one and only switches from the former state to the latter one. If an individual has turned into an alarmed state, it stays in the state during the process of information propagation. Initially, each individual is set to be at the naïve state and information is tapped into the system by perturbing an individual at the boundaries (alerting it to the alarmed state). The system evolves as individuals turn into the alarmed state, according to the quorum response rules, consecutively. We find that by fine-tuning the parameters of the mean and the standard deviation of the Gaussian distribution, the system is poised at a critical state. We present the phase diagrams to exhibit that the parameter space is divided into a super-critical and a sub-critical zone, in which the dynamics of information propagation varies largely. We then investigate the effects of the individuals' mobility on the critical state, and allow a proportion of randomly chosen individuals to exchange their positions at each time step. We find that mobility breaks down criticality of the system. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  13. Hospital Preparedness to Respond to Biological and Chemical Terrorist Attack

    International Nuclear Information System (INIS)

    Florin, P.

    2007-01-01

    There is a growing concern about the terrorist use of chemical or biological agents against civilian population. A large proportion of hospitals are probably poorly prepared to handle victims of chemical or biological terrorism. At national level, starting with 2008 hospitals will be under the administration and control of local authorities. That is good opportunities for local authorities and public health office to tailor the activity of the hospitals to the real needs in the area of responsibility, and to allocate the suitable budget for them. Commonly hospitals are not fully prepared to respond to massive casualty disaster of any kind, either i their capacity to care for large numbers of victims or in their ability to provide care in coordination with a regional or national incident command structure. Preparedness activities to respond properly to chemical or biological attack including the adequate logistic, the principle of training and drill for the hospital emergency units and medical personal, communication and integration of the hospital team in local and regional civil response team are developed by the author.(author)

  14. Radiation processing of biological tissues for nuclear disaster management

    International Nuclear Information System (INIS)

    Singh, Rita

    2012-01-01

    A number of surgical procedures require tissue substitutes to repair or replace damaged or diseased tissues. Biological tissues from human donor like bone, skin, amniotic membrane and other soft tissues can be used for repair or reconstruction of the injured part of the body. Tissues from human donor can be processed and banked for orthopaedic, spinal, trauma and other surgical procedures. Allograft tissues provide an excellent alternative to autografts. The use of allograft tissue avoids the donor site morbidity and reduces the operating time, expense and trauma associated with the acquisition of autografts. Further, allografts have the added advantage of being available in large quantities. This has led to a global increase in allogeneic transplantation and development of tissue banking. However, the risk of infectious disease transmission via tissue allografts is a major concern. Therefore, tissue allografts should be sterilized to make them safe for clinical use. Radiation processing has well appreciated technological advantages and is the most suitable method for sterilization of biological tissues. Radiation processed biological tissues can be provided by the tissue banks for the management of injuries due to a nuclear disaster. A nuclear detonation will result in a large number of casualties due to the heat, blast and radiation effects of the weapon. Skin dressings or skin substitutes like allograft skin, xenograft skin and amniotic membrane can be used for the treatment of thermal burns and radiation induced skin injuries. Bone grafts can be employed for repairing fracture defects, filling in destroyed regions of bone, management of open fractures and joint injuries. Radiation processed tissues have the potential to repair or reconstruct damaged tissues and can be of great assistance in the treatment of injuries due to the nuclear weapon. (author)

  15. Biological and Chemical Weapons: Criminal Sanctions and Federal Regulations

    National Research Council Canada - National Science Library

    Garcia, Michael J

    2004-01-01

    .... In accordance with these obligations, the United States has enacted various federal requirements and criminal sanctions applying to biological and chemical weapons, Re cent anti4errorisrn legislation...

  16. Application of synthetic biology for production of chemicals in yeast Saccharomyces cerevisiae.

    Science.gov (United States)

    Li, Mingji; Borodina, Irina

    2015-02-01

    Synthetic biology and metabolic engineering enable generation of novel cell factories that efficiently convert renewable feedstocks into biofuels, bulk, and fine chemicals, thus creating the basis for biosustainable economy independent on fossil resources. While over a hundred proof-of-concept chemicals have been made in yeast, only a very small fraction of those has reached commercial-scale production so far. The limiting factor is the high research cost associated with the development of a robust cell factory that can produce the desired chemical at high titer, rate, and yield. Synthetic biology has the potential to bring down this cost by improving our ability to predictably engineer biological systems. This review highlights synthetic biology applications for design, assembly, and optimization of non-native biochemical pathways in baker's yeast Saccharomyces cerevisiae We describe computational tools for the prediction of biochemical pathways, molecular biology methods for assembly of DNA parts into pathways, and for introducing the pathways into the host, and finally approaches for optimizing performance of the introduced pathways. © FEMS 2015. All rights reserved. For permissions, please e-mail: journals.permission@oup.com.

  17. Dovetailing biology and chemistry: integrating the Gene Ontology with the ChEBI chemical ontology

    Science.gov (United States)

    2013-01-01

    Background The Gene Ontology (GO) facilitates the description of the action of gene products in a biological context. Many GO terms refer to chemical entities that participate in biological processes. To facilitate accurate and consistent systems-wide biological representation, it is necessary to integrate the chemical view of these entities with the biological view of GO functions and processes. We describe a collaborative effort between the GO and the Chemical Entities of Biological Interest (ChEBI) ontology developers to ensure that the representation of chemicals in the GO is both internally consistent and in alignment with the chemical expertise captured in ChEBI. Results We have examined and integrated the ChEBI structural hierarchy into the GO resource through computationally-assisted manual curation of both GO and ChEBI. Our work has resulted in the creation of computable definitions of GO terms that contain fully defined semantic relationships to corresponding chemical terms in ChEBI. Conclusions The set of logical definitions using both the GO and ChEBI has already been used to automate aspects of GO development and has the potential to allow the integration of data across the domains of biology and chemistry. These logical definitions are available as an extended version of the ontology from http://purl.obolibrary.org/obo/go/extensions/go-plus.owl. PMID:23895341

  18. Chemical and Biological Defense: DOD Needs Consistent Policies and Clear Processes to Address the Survivability of Weapon Systems Against Chemical and Biological Threats

    National Research Council Canada - National Science Library

    2006-01-01

    DOD, joint, and military service weapon system acquisition policies inconsistently address and do not establish a clear process for considering and testing system chemical and biological survivability...

  19. Molecular radiation biology: Future aspects

    International Nuclear Information System (INIS)

    Hagen, U.

    1990-01-01

    Future aspects of molecular radiation biology may be envisaged by looking for unsolved problems and ways to analyse them. Considering the endpoints of cellular radiation effects as cell inactivation, chromosome aberrations, mutation and transformation, the type of DNA damage in the irradiated cell and the mechanisms of DNA repair as excision repair, recombination repair and mutagenic repair are essential topics. At present, great efforts are made to identify, to clone and to sequence genes involved in the control of repair of DNA damage and to study their regulation. There are close relationships between DNA repair genes isolated from various organisms, which promises fast progress for the molecular analysis of repair processes in mammalian cells. More knowledge is necessary regarding the function of the gene products, i.e. enzymes and proteins involved in DNA repair. Effort should be made to analyse the enzymatic reactions, leading to an altered nucleotide sequence, encountered as a point mutation. Mislead mismatch repair and modulation of DNA polymerase might be possible mechanisms. (orig.)

  20. Radiation 2006. In association with the Polymer Division, Royal Australian Chemical Institute. Incorporating the 21st AINSE Radiation Chemistry Conference and the 18th Radiation Biology Conference, conference handbook

    International Nuclear Information System (INIS)

    Wroe, Andrew; Rosenfeld, A. B.; Cornelius, I. M.; Pisacane, V. L.; Ziegler, J. F.; M E Nelson, M. E.; Cucinotta, F.; Zaider, M.; Dicello, J. F.

    2006-01-01

    Full text: Humans exploring outer space are exposed to space radiation composed of high-energy protons and heavy ions. In deep space, the radiation environment consists mainly of galactic cosmic radiation (GCR). In the energy range from 100MeV per nucleon to 10GeV per nucleon, the GCR consists of 87 percent protons, 12 percent helium ions, and 1 percent heavier ions (Simpson 1983). Protons are also the major component of solar particle events (SPEs), with a smaller contribution by helium and heavier ions emitted from the Sun. Organizations planning and conducting space travel such as NASA and ESA have a fundamental interest in evaluating adverse health effects induced by GCR and SPEs in human space explorers and their offspring. In future space missions both personnel and electronic devices are going to be required to perform for longer periods within a radiation environment. For these applications it is imperative that heterogeneous shielding structures, biological structures and the secondaries produced by such structures be investigated thoroughly. The spectra of secondaries can be investigated and monitored utilising solid-state microdosimeters as have been developed at the CMRP. The effectiveness of such shielding in inhibiting the production of harmful secondaries can also be investigated and in turn optimised utilising Monte Carlo radiation transport simulation studies that utilise microdosimetry as the measurement parameter. The microdosimetric spectra produced by a solar proton radiation field traversing heterogeneous structures, such as spacecraft shielding and the astronaut will be investigated as part of this simulation study. The effectiveness of the microdosimeter in such an environment will also be assessed and presented

  1. Biological and Chemical Weapons: Criminal Sanctions and Federal Regulations

    National Research Council Canada - National Science Library

    Garcia, Michael J

    2004-01-01

    The Biological Weapons Convention and the Chemical Weapons Convention, both of which have been signed and ratified by the United States, obligate signatory parties to enact legislation or otherwise...

  2. The Control of Chemical and Biological Weapons.

    Science.gov (United States)

    Alexander, Archibald S.; And Others

    This book is composed of four papers prepared to illuminate the problem areas which might arise if the policies of the 1925 Geneva Protocol and other measures to limit chemical and biological weapons are ratified by the United States Senate. The papers included are: Legal Aspects of the Geneva Protocol of 1925; The Use of Herbicides in War: A…

  3. Analysis of mechanism of complex chemical reaction taking radiation chemical purification of gases from impurities as an example

    International Nuclear Information System (INIS)

    Gerasimov, G.Ya.; Makarov, V.N.

    1997-01-01

    Algorithm of selecting optimal mechanism of complex chemical reaction, enabling to reduce the number of its stages, is suggested. Main steps of constructing the kinetic model of the medium are considered, taking the radiation chemical purification (using fast electron radiation) of gases (N 2 , CO 2 , O 2 and others) from impurities as an example. 17 refs., 3 figs., 2 tabs

  4. Physio-chemical evaluation and biological activity of Ajuga ...

    African Journals Online (AJOL)

    Physio-chemical evaluation and biological activity of Ajuga bracteosa wall and Viola odoroto Linn. Anwar Ali Shad, M. Zeeshan, Hina Fazal, Hamid Ullah Shah, Shabir Ahmed, Hasem Abeer, E. F. Abd_Allah, Riaz Ullah, Hamid Afridi, Akash tariq, Muhammad Adnan Asma ...

  5. Researchers study decontamination of chemical, biological warfare agents

    OpenAIRE

    Trulove, Susan

    2007-01-01

    The U.S. Army Research Office has awarded Virginia Tech a $680,000 grant over two years to build an instrument that can be used to study the chemistry of gases that will decompose both chemical and biological warfare agents on surfaces.

  6. HExpoChem: a systems biology resource to explore human exposure to chemicals

    DEFF Research Database (Denmark)

    Taboureau, Olivier; Jacobsen, Ulrik Plesner; Kalhauge, Christian Gram

    2013-01-01

    of computational biology approaches are needed to assess the health risks of chemical exposure. Here we present HExpoChem, a tool based on environmental chemicals and their bioactivities on human proteins with the objective of aiding the qualitative exploration of human exposure to chemicals. The chemical...

  7. Properties of spectra of the reflected and transmitted radiation during propagation of relativistically strong laser pulses in underdense plasmas

    International Nuclear Information System (INIS)

    Bulanov, S.V.; Esirkepov, T.Z.; Naumova, N.M.

    1996-01-01

    Particle-in-cell simulation has been performed to study the spatial-temporal evolution of the pulse propagating in an underdense plasma. The spectra both of the reflected and transmitted radiation are investigated. The spectrum structure of the reflected radiation is due to the backward stimulated Raman scattering meanwhile the transmitted radiation structure is mainly due to the nonlinear self-phase-modulation. The influence of the pulse shape on the transmitted radiation spectrum is revealed. The dependence of the main features of the spectrum and the self-consistent pulse distortion is found. The pulse distortion is accompanied by the relativistic electrons generation. copyright 1996 American Institute of Physics

  8. Biology Branch

    Energy Technology Data Exchange (ETDEWEB)

    Baldwin, W F

    1974-12-31

    Progress is reported on the following studies in biochemistry and molecular biology: study of long pyrimidine polynucleotides in DNA; isolation of thymine dimers from Schizosaccharomyces pombe; thermal stability of high molecular weight RNA; nucleases of Micrococcus radiodurans; effect of ionizing radiation on M. radiodurans cell walls and cell membranes; chemical modification of nucleotides; exonucleases of M. radiodurans; and enzymatic basis of repair of radioinduced damage in M. radiodurans. Genetics, development, and population studies include repair pathways and mutation induction in yeast; induction of pure mutant clones in yeast; radiosensitivity of bacteriophage T4; polyacrylamide gel electrophoresis of bacteriophage T4; radiation genetics of Dahibominus; and radiation studies on bitting flies. (HLW)

  9. Technological advancements for the detection of and protection against biological and chemical warfare agents.

    Science.gov (United States)

    Eubanks, Lisa M; Dickerson, Tobin J; Janda, Kim D

    2007-03-01

    There is a growing need for technological advancements to combat agents of chemical and biological warfare, particularly in the context of the deliberate use of a chemical and/or biological warfare agent by a terrorist organization. In this tutorial review, we describe methods that have been developed both for the specific detection of biological and chemical warfare agents in a field setting, as well as potential therapeutic approaches for treating exposure to these toxic species. In particular, nerve agents are described as a typical chemical warfare agent, and the two potent biothreat agents, anthrax and botulinum neurotoxin, are used as illustrative examples of potent weapons for which countermeasures are urgently needed.

  10. Harmonization of risk management approaches: radiation and chemical exposures

    Energy Technology Data Exchange (ETDEWEB)

    Srinivasan, P. [Bhabha Atomic Research Centre, Radiation Safety Systems Div., Mumbai (India)

    2006-07-01

    Assessment of occupational and public risk from the environmental pollutants like chemicals, radiation, etc demands that the effects be considered not only from each individual pollutant, but from the combination of all the pollutants. An integrated risk assessment system needs to be in place to have an overall risk perspective for the benefit of policy makers and decision takers to try to achieve risk reduction in totality. The basis for risk-based radiation dose limits is derived from epidemiological studies, which provide a rich source of data largely unavailable to chemical risk assessors. In addition, use of the principle of optimization as expressed in the ALARA concept has resulted in a safety culture, which is much more than just complying with stipulated limits. The conservative hypothesis of no-threshold dose-effect relation (ICRP) is universally assumed. The end-points and the severity of different classes of pollutants and even different pollutants in a same class vary over a wide range. Hence, it is difficult to arrive at a quantitative value for the net detriment that weighs the various types of end-points and various classes of pollutants. Once the risk due to other pollutants is quantified by some acceptable methodology, it can be expressed in terms of the Risk Equivalent Radiation Dose (R.E.R.D.) for easy comparison with options involving radiation exposure. This paper is an effort to use to quantify and present the risk due to exposure to chemicals and radiation in a common scale for the purpose of easy comparison to facilitate decision taking. (authors)

  11. Harmonization of risk management approaches: radiation and chemical exposures

    International Nuclear Information System (INIS)

    Srinivasan, P.

    2006-01-01

    Assessment of occupational and public risk from the environmental pollutants like chemicals, radiation, etc demands that the effects be considered not only from each individual pollutant, but from the combination of all the pollutants. An integrated risk assessment system needs to be in place to have an overall risk perspective for the benefit of policy makers and decision takers to try to achieve risk reduction in totality. The basis for risk-based radiation dose limits is derived from epidemiological studies, which provide a rich source of data largely unavailable to chemical risk assessors. In addition, use of the principle of optimization as expressed in the ALARA concept has resulted in a safety culture, which is much more than just complying with stipulated limits. The conservative hypothesis of no-threshold dose-effect relation (ICRP) is universally assumed. The end-points and the severity of different classes of pollutants and even different pollutants in a same class vary over a wide range. Hence, it is difficult to arrive at a quantitative value for the net detriment that weighs the various types of end-points and various classes of pollutants. Once the risk due to other pollutants is quantified by some acceptable methodology, it can be expressed in terms of the Risk Equivalent Radiation Dose (R.E.R.D.) for easy comparison with options involving radiation exposure. This paper is an effort to use to quantify and present the risk due to exposure to chemicals and radiation in a common scale for the purpose of easy comparison to facilitate decision taking. (authors)

  12. Chemical films and monolayers on the water surface and their interactions with ultraviolet radiation: a pilot investigation

    International Nuclear Information System (INIS)

    Schouten, Peter; Lemckert, Charles; Underhill, Ian; Turner, Geoff; Turnbull, David; Parisi, Alfio; Downs, Nathan

    2011-01-01

    Over the past 50 years numerous types of chemical films and monolayers have been deployed on top of a wide variety of water reserves in an endeavour to reduce evaporation. To date very little knowledge has been assimilated on how these chemical films and monolayers, once applied to a water surface, influence the underwater UV light field and, in turn, the delicate ecosystems that exist in aquatic environments. This manuscript presents underwater UV exposure profiles weighted to the DNA damage action spectrum measured under an octadecanol/hexadecanol/lime chemical film mixture, a silicone-based chemical film and an octadecanol monolayer applied to the water surface. UV transmission and absorption properties were also evaluated for each of these chemical films and monolayers. From this it was found that when chemical films/monolayers are applied to surface water they can reduce the penetration of biologically effective UV into the water column by up to 85% at a depth as small as 1 cm. This could have a positive influence on the aquatic ecosystem, as harmful UV radiation may be prevented from reaching and consequently damaging a variety of life forms or it could have a negative effect by potentially stopping aquatic organisms from adapting to solar ultraviolet radiation over extended application intervals. Additionally, there is currently no readily applicable system or technique available to readily detect or visualize chemical films and monolayers on the water surface. To overcome this problem a new method of monolayer and chemical film visualization, using a UV camera system, is detailed and tested and its applicability for usage in both laboratory-based trials and real-world operations is evaluated

  13. Chemical films and monolayers on the water surface and their interactions with ultraviolet radiation: a pilot investigation

    Science.gov (United States)

    Schouten, Peter; Lemckert, Charles; Turnbull, David; Parisi, Alfio; Downs, Nathan; Underhill, Ian; Turner, Geoff

    2011-06-01

    Over the past 50 years numerous types of chemical films and monolayers have been deployed on top of a wide variety of water reserves in an endeavour to reduce evaporation. To date very little knowledge has been assimilated on how these chemical films and monolayers, once applied to a water surface, influence the underwater UV light field and, in turn, the delicate ecosystems that exist in aquatic environments. This manuscript presents underwater UV exposure profiles weighted to the DNA damage action spectrum measured under an octadecanol/hexadecanol/lime chemical film mixture, a silicone-based chemical film and an octadecanol monolayer applied to the water surface. UV transmission and absorption properties were also evaluated for each of these chemical films and monolayers. From this it was found that when chemical films/monolayers are applied to surface water they can reduce the penetration of biologically effective UV into the water column by up to 85% at a depth as small as 1 cm. This could have a positive influence on the aquatic ecosystem, as harmful UV radiation may be prevented from reaching and consequently damaging a variety of life forms or it could have a negative effect by potentially stopping aquatic organisms from adapting to solar ultraviolet radiation over extended application intervals. Additionally, there is currently no readily applicable system or technique available to readily detect or visualize chemical films and monolayers on the water surface. To overcome this problem a new method of monolayer and chemical film visualization, using a UV camera system, is detailed and tested and its applicability for usage in both laboratory-based trials and real-world operations is evaluated.

  14. Radiation 2006. In association with the Polymer Division, Royal Australian Chemical Institute. Incorporating the 21st AINSE Radiation Chemistry Conference and the 18th Radiation Biology Conference, conference handbook

    International Nuclear Information System (INIS)

    Cornelius, I; Wroe, A.; Kwan, I.; Painuly, N.; Perera, L.; Lerch, M.; Takacs, G.; Rosenfeld, A.; Siegbahn, E.; Reinhard, M.; Marchetto, F.; Cirio, R.; Prokopovich, D.

    2006-01-01

    Full text: The Centre for Medical Radiation Physics (CMRP) and it's collaborative partners are actively involved with the development of semiconductor detectors and dosimeters for radiation protection, radiation oncology, and nuclear medicine applications. The GEANT4 Monte Carlo toolkit is used extensively in our current research projects. This poster will give an overview of our experience with the toolkit, including: the use of GEANT4 to calculate the dose distribution of HDR brachytherapy sources for comparison with TLD, ionisation chamber, and MOSFET measurements; the simulation of silicon microdosimetry measurements of an isotopic neutron source; the simulation of MOSFET dosimetry of synchrotron microbeams to understand lateral dose enhancement effects (see figure); estimating the effectiveness of various space shielding configurations using microdosimetry based calculations of biological dose; simulating small animal PET scanners using GATE; and the macroscopic verification of light ion fragmentation models via comparison with experimental data for energies and targets relevant to carbon ion therapy. Figures: Simulation of the response of an 'edge-on' MOSFET to a synchrotron microbeam. Dose profile obtained using GEANT4 and PENELOPE the lateral dose enhancement from the silicon substrate of the MOSFET is illustrated by the skewness of the dose profile

  15. Oxidative decontamination of chemical and biological warfare agents using L-Gel.

    Science.gov (United States)

    Raber, Ellen; McGuire, Raymond

    2002-08-05

    A decontamination method has been developed using a single reagent that is effective both against chemical warfare (CW) and biological warfare (BW) agents. The new reagent, "L-Gel", consists of an aqueous solution of a mild commercial oxidizer, Oxone, together with a commercial fumed silica gelling agent, Cab-O-Sil EH-5. L-Gel is non-toxic, environmentally friendly, relatively non-corrosive, maximizes contact time because of its thixotropic nature, clings to walls and ceilings, and does not harm carpets or painted surfaces. The new reagent also addresses the most demanding requirements for decontamination in the civilian sector, including availability, low maintenance, ease of application and deployment by a variety of dispersal mechanisms, minimal training and acceptable expense. Experiments to test the effectiveness of L-Gel were conducted at Lawrence Livermore National Laboratory and independently at four other locations. L-Gel was tested against all classes of chemical warfare agents and against various biological warfare agent surrogates, including spore-forming bacteria and non-virulent strains of real biological agents. Testing showed that L-Gel is as effective against chemical agents and biological materials, including spores, as the best military decontaminants.

  16. An assessment of the biological and physico-chemical ...

    African Journals Online (AJOL)

    Physico-chemical parameters and biological (phytoplanktons and macrophytes) composition of Bindare and Hanwa streams in Zaria, Nigeria were studied for a period of three months (September to November 2008). The streams have catchments of varying land use patterns ranging from agricultural (farming and animal ...

  17. Seeking the chemical roots of darwinism: bridging between chemistry and biology.

    Science.gov (United States)

    Pross, Addy

    2009-08-24

    Chemistry and biology are intimately connected sciences yet the chemistry-biology interface remains problematic and central issues regarding the very essence of living systems remain unresolved. In this essay we build on a kinetic theory of replicating systems that encompasses the idea that there are two distinct kinds of stability in nature-thermodynamic stability, associated with "regular" chemical systems, and dynamic kinetic stability, associated with replicating systems. That fundamental distinction is utilized to bridge between chemistry and biology by demonstrating that within the parallel world of replicating systems there is a second law analogue to the second law of thermodynamics, and that Darwinian theory may, through scientific reductionism, be related to that second law analogue. Possible implications of these ideas to the origin of life problem and the relationship between chemical emergence and biological evolution are discussed.

  18. Unidirectional THz radiation propagation in BiFeO3

    Science.gov (United States)

    Room, Toomas

    The mutual coupling between magnetism and electricity present in many multiferroic materials permit the magnetic control of the electric polarization and the electric control of the magnetization. These static magnetoelectric (ME) effects are of enormous interest: The ability to write a magnetic state current-free by an electric voltage would provide a huge technological advantage. However, ME coupling changes the low energy electrodynamics of these materials in unprecedented way - optical ME effects give rise to unidirectional light propagation as recently observed in low-temperature multiferroics. The transparent direction can be switched with dc magnetic or electric field, thus opening up new possibilities to manipulate the propagation of electromagnetic waves in multiferroic materials. We studied the unidirectional transmission of THz radiation in BiFeO3 crystals, the unique multiferroic compound offering a real potential for room temperature applications. The electrodynamics of BiFeO3 at 1THz and below is dominated by the spin wave modes of cycloidal spin order. We found that the optical magnetoelectric effect generated by spin waves in BiFeO3 is robust enough to cause considerable nonreciprocal directional dichroism in the GHz-THz range even at room temperature. The supporting theory attributes the observed unidirectional transmission to the spin-current-driven dynamic ME effect. Our work demonstrates that the nonreciprocal directional dichroism spectra of low energy excitations and their theoretical analysis provide microscopic model of ME couplings in multiferroic materials. Recent THz spectroscopy studies of multiferroic materials are an important step toward the realization of optical diodes, devices which transmit light in one but not in the opposite direction.

  19. 76 FR 68809 - Bureau of International Security and Nonproliferation; Termination of Chemical and Biological...

    Science.gov (United States)

    2011-11-07

    ..., Office of Missile, Biological, and Chemical Nonproliferation, Bureau of International Security and... DEPARTMENT OF STATE [Public Notice: 7678] Bureau of International Security and Nonproliferation; Termination of Chemical and Biological Weapons (CBW) Proliferation Sanctions Against a Foreign Person AGENCY...

  20. Radiation sterilization of hydrocortisone acetate

    International Nuclear Information System (INIS)

    Charef, A.; Boussaha, A.

    1989-09-01

    The feasibility of using high energy ionizing radiation for the sterilization of hydrocortisone acetate was investigated. Hydrocortisone acetate in the form of powder was exposed to different dose levels of gamma radiation using a Cobalt-60 source. The irradiated samples were examined by various physico-chemical techniques in order to detect possible radiolysis products. It was of interest to know if one could insure sterility and retain biological properties of the drug by suitable choice of radiation dose. The results showed that a 10 KGy radiation dose causes no change in the physico-chemical properties of the drug and is sufficient to obtain contaminant-free product

  1. Department of Radiation and Environmental Biology - Overview

    International Nuclear Information System (INIS)

    Cebulska-Wasilewska, A.

    2001-01-01

    Full text: In the year 2000 we completed our study of the genotoxic influence of occupational exposure to pesticides on human cells, and their susceptibility to radiation in particular. Examining blood samples from four countries: Greece, Hungary, Poland and Spain we found that exposure to pesticides usually resulted in an increased susceptibility to the UV-C radiation, although statistical significance could only be concluded for inhabitants of Poland. In Spain, exposure to pesticides was proved to impair the lymphocyte DNA repair capability, while for the Polish group this repair capability appeared enhanced in people exposed to pesticides (see the research reports below). The possible influence of lifestyle or particular diet on the observed national differences would probably be worth analyzing. We also investigate the biological effectiveness of therapeutic beams (neutrons and X-rays). Experimental part of such study, concerning neutrons of different mean energies, is over and the results are now being processed. Our work covers hot issues of environmental and radiation biology making us research partners to many domestic and foreign scientific institutions. Our proficiency in the field is also reflected by membership in various expert boards (e.g. evaluating research applications for the Fifth EU Framework Programme for RTD and Demonstration Activities in the field 'Environment and Health', lecturing in the 2000 NATO IOS Life Science Books). We have entered the 5 th EU Programme Scheme within the EXPAH project starting January 1, 2001. (author)

  2. Combined genetic effects of chemicals and radiation

    International Nuclear Information System (INIS)

    Kada, T.; Inoue, T.; Yokoiyama, A.; Russel, L.B.

    1979-01-01

    Interactions of chemicals and radiation are complex and there may exist other unexpected patterns that are not mentioned. We show some examples. Photodynamic mutation induction by fluorescein dyes and Radiosensitization with iodine compounds are classified as Interactions of chemicals and radiation outside of the cell. On the other hand, the Antimutagenic effects of cobaltous chloride is concerned with events taking place in cells that had already been exposed to a mutagenic agent. It is likely that the action of a mutagenic agent is not direct and that cellular functions, such as mutators or repair systems, are involved in the mutagenesis initiated by the agent. Such cellular functions can be affected by a second agent. In sexually reproducing organisms, the two agents can also act on separate cells (male and female germcells) which subsequently fuse. Interaction effects of all types will be useful in future research in shedding light on the main pathways of mutagenesis

  3. Final Programme and Abstracts. COST Action CM0603 Free Radicals in Chemical Biology (CHEMBIORADICAL) Joint Working Group

    International Nuclear Information System (INIS)

    2008-01-01

    The main objective of the Action is to promote a chemical biology approach for the investigation of free radical pathways. Chemical reactivity and molecular libraries are the start of a multidisciplinary research context 'from small molecules to large systems', culminating in the biological complexity. The Action aims at improving communication and exchange among neighbouring scientific fields, such as chemistry with several domains of life sciences, specifically addressing the real barrier consisting of specialist language and tools. Four working groups address the formation, reactivity and fate of free radicals involving bio-molecules, such as unsaturated lipids, aromatic-, cyclic- and sulphur-containing amino acid residues, sugar and base moieties of nucleic acids. Tasks concern the role of free radicals in normal cell metabolism and in damages, defining structural and functional modifications, in the framework of physiologically and pathologically related processes relevant to human quality of life and health. In the programme are involved 19 universities and research institutions from nearly all European countries. The research programme of the group has been carried and is still continued based on close bilateral collaboration with many foreign laboratories from Europe, USA (Notre Dame Radiation Laboratory) and Chile

  4. CHEMICAL VAPOUR DEPOSITION FROM A RADIATION-SENSITIVE PRECURSOR

    DEFF Research Database (Denmark)

    2017-01-01

    The present invention relates in one aspect to a method of depositing a thin film on a substrate by chemical vapour deposition (CVD) from a radiation-sensitive precursor substance. The method comprises the steps of: (i) placing the substrate in a reaction chamber of a CVD system; (ii) heating...... heating pulse followed by an idle period; (iii) during at least one of the idle periods, providing a pressure pulse of precursor substance inside the reaction chamber by feeding at least one precursor substance to the reaction chamber so as to establish a reaction partial pressure for thin film deposition...... is formed. According to a further aspect, the invention relates to a chemical vapour deposition (CVD) system for depositing a thin film onto a substrate using precursor substances containing at least one radiation sensitive species....

  5. Radiation 2006. In association with the Polymer Division, Royal Australian Chemical Institute. Incorporating the 21st AINSE Radiation Chemistry Conference and the 18th Radiation Biology Conference, conference handbook

    International Nuclear Information System (INIS)

    Barner, L.; Davis, T. P.; Stenzel, M. H.; Barner-Kowollik, C.

    2006-01-01

    Full text: The reversible addition fragmentation chain transfer (RAFT) process is a controlled/'living' free radical polymerisation process that was invented in Australia by the Commonwealth Scientific and Industrial Research Organisation (CSRIO) group led by Ezio Rizzardo. RAFT polymerisation has proven to be a powerful tool for the synthesis of polymers with predetermined molecular weight and low polydispersity. The RAFT process is capable of effecting living free radical polymerisation control over a great variety of monomers (eg (meth)acrylates, styrenes, acrylamides, vinyl acetate). The RAFT technique uses thiocarbonylthio compounds to mediate the polymerisation via a reversible chain transfer process. This leads to the establishment of an equilibrium under which all the propagating chains have approximately the same chain length at the same instant of time. The RAFT agent typically possesses a thiocarbonylthio group (S=C-S) with substituents R (radical leaving group) and Z (activating/stabilising group), which govern the reaction kinetics and the degree of structural control. In 2001, we reported the synthesis of RAFT agents (phenyl dithio acetates) that can be applied at low/ambient temperatures in the polymerization of alkyl acrylates and styrene. Low/ambient temperature RAFT agents allow the application of γ-radiation as source of initiation. The combination of γ-radiation and ambient temperature RAFT agents allows performing living polymerization at ambient temperature up to high conversions. This technique also opens the possibility to graft narrow polydisperse polymers from existing polymer surfaces. We have applied RAFT polymerization in conjunction with γ-radiation to graft various monomers (e.g. styrene, m-isopropenyl-α,α ' -dimethylbenzyl isocyanate (TMI), N,N ' -dimethyl acrylamide) from solid polypropylene phases that can be used for applications in combinatorial chemistry (eg peptide synthesis and scavenger reactions)

  6. Biological effects of ionizing radiations. Radiological accident from Goiania, GO, Brazil

    International Nuclear Information System (INIS)

    Okuno, Emico

    2013-01-01

    This article presents the fundaments of radiation physics, the natural and artificial sources, biological effects, radiation protection. We also examine the sequence of events that resulted in Goiania accident with a source of caesium-137 from abandoned radiotherapy equipment and its terrible consequences. (author)

  7. Human · mouse genome analysis and radiation biology. Proceedings

    International Nuclear Information System (INIS)

    Hori, Tada-aki

    1994-03-01

    This issue is the collection of the papers presented at the 25th NIRS symposium on Human, Mouse Genome Analysis and Radiation Biology. The 14 of the presented papers are indexed individually. (J.P.N.)

  8. Generation of infrared supercontinuum radiation: spatial mode dispersion and higher-order mode propagation in ZBLAN step-index fibers

    DEFF Research Database (Denmark)

    Ramsay, Jacob Søndergaard; Dupont, Sune Vestergaard Lund; Johansen, Mikkel Willum

    2013-01-01

    Using femtosecond upconversion we investigate the time and wavelength structure of infrared supercontinuum generation. It is shown that radiation is scattered into higher order spatial modes (HOMs) when generating a supercontinuum using fibers that are not single-moded, such as a step-index ZBLAN...... fiber. As a consequence of intermodal scattering and the difference in group velocity for the modes, the supercontinuum splits up spatially and temporally. Experimental results indicate that a significant part of the radiation propagates in HOMs. Conventional simulations of super-continuum generation do...

  9. Vanguards of paradigm shift in radiation biology. Radiation-induced adaptive and bystander responses

    International Nuclear Information System (INIS)

    Matsumoto, Hideki; Hamada, Nobuyuki; Kobayashi, Yasuhiko; Takahashi, Akihisa; Ohnishi, Takeo

    2007-01-01

    The risks of exposure to low dose ionizing radiation (below 100 mSv) are estimated by extrapolating from data obtained after exposure to high dose radiation, using a linear no-threshold model (LNT model). However, the validity of using this dose-response model is controversial because evidence accumulated over the past decade has indicated that living organisms, including humans, respond differently to low dose/low dose-rate radiation than they do to high dose/high dose-rate radiation. In other words, there are accumulated findings which cannot be explained by the classical ''target theory'' of radiation biology. The radioadaptive response, radiation-induced bystander effects, low-dose radio-hypersensitivity, and genomic instability are specifically observed in response to low dose/low dose-rate radiation, and the mechanisms underlying these responses often involve biochemical/molecular signals that respond to targeted and non-targeted events. Recently, correlations between the radioadaptive and bystander responses have been increasingly reported. The present review focuses on the latter two phenomena by summarizing observations supporting their existence, and discussing the linkage between them from the aspect of production of reactive oxygen and nitrogen species. (author)

  10. Compatible biological and chemical control systems for Rhizoctonia solani in potato

    NARCIS (Netherlands)

    Boogert, van den P.H.J.F.; Luttikholt, A.J.G.

    2004-01-01

    A series of chemical and biological control agents were tested for compatibility with the Rhizoctonia-specific biocontrol fungus Verticillium biguttatum aimed at designing novel control strategies for black scurf (Rhizoctonia solani) and other tuber diseases in potato. The efficacy of chemicals,

  11. Advances in radiation biology: Relative radiation sensitivities of human organ systems. Volume 12

    International Nuclear Information System (INIS)

    Lett, J.T.; Altman, K.I.; Ehmann, U.K.; Cox, A.B.

    1987-01-01

    This volume is a thematically focused issue of Advances in Radiation Biology. The topic surveyed is relative radiosensitivity of human organ systems. Topics considered include relative radiosensitivities of the thymus, spleen, and lymphohemopoietic systems; relative radiosensitivities of the small and large intestine; relative rediosensitivities of the oral cavity, larynx, pharynx, and esophagus; relative radiation sensitivity of the integumentary system; dose response of the epidermal; microvascular, and dermal populations; relative radiosensitivity of the human lung; relative radiosensitivity of fetal tissues; and tolerance of the central and peripheral nervous system to therapeutic irradiation

  12. Advances in radiation biology: Relative radiation sensitivities of human organ systems. Volume 12

    Energy Technology Data Exchange (ETDEWEB)

    Lett, J.T.; Altman, K.I.; Ehmann, U.K.; Cox, A.B.

    1987-01-01

    This volume is a thematically focused issue of Advances in Radiation Biology. The topic surveyed is relative radiosensitivity of human organ systems. Topics considered include relative radiosensitivities of the thymus, spleen, and lymphohemopoietic systems; relative radiosensitivities of the small and large intestine; relative rediosensitivities of the oral cavity, larynx, pharynx, and esophagus; relative radiation sensitivity of the integumentary system; dose response of the epidermal; microvascular, and dermal populations; relative radiosensitivity of the human lung; relative radiosensitivity of fetal tissues; and tolerance of the central and peripheral nervous system to therapeutic irradiation.

  13. Radiation-dosimetry and chemical-toxicity considerations for 99Tc

    International Nuclear Information System (INIS)

    Coffey, J.L.; Hayes, R.L.; Rafter, J.J.; Watson, E.E.; Carlton, J.E.

    1982-01-01

    Technetium-99 (T/sub 1/2/ = 2.13 x 10 5 y) is produced in the fission of 235 U and 239 Pu. Technitium-99 has been found to contaminate some areas of the uranium re-enrichment process. ICRP-30 Part 2 gives the Annual Limit on Intake (ALI) for 99 Tc as 2 x 10 8 Bq (5.4 mCi) for class D inhaled material (IC80). The ICRP states clearly that ALIs are based on radiation risk only and that chemical toxicity is not considered (IC79). No data were found on the chemical toxicity of 99 Tc, possibly because there are no stable isotopes of technetium with which to study the toxicity, although, because of its long T/sub 1/2/, 99 Tc can, for all practical purposes, be considered stable. The ALI values for 99 Tc are based on data obtained using high specific activity /sup 99m/Tc (T/sub 1/2/ = 6 h) and /sup 95m/Tc (T/sub 1/2/ = 61 days). Since the specific activities of 99 Tc and Na 99 TcO 4 are quite low (17 mCi/g and 9 mCi/g, respectively) and 99 Tc is available in abundant supply, we have attempted to assess the relative radiation and chemical hazards that are associated with this radionuclide. The approach in this study was (1) to study the effect of chemical dose on the whole body retention of 99 Tc sodium pertechnetate in rats and to relate these effects to the radiation dose and the ALI and (2) to compare the chemical toxicity of 99 Tc sodium pertechnetate with the ALI at different chemical dose levels

  14. Improving integrative searching of systems chemical biology data using semantic annotation.

    Science.gov (United States)

    Chen, Bin; Ding, Ying; Wild, David J

    2012-03-08

    Systems chemical biology and chemogenomics are considered critical, integrative disciplines in modern biomedical research, but require data mining of large, integrated, heterogeneous datasets from chemistry and biology. We previously developed an RDF-based resource called Chem2Bio2RDF that enabled querying of such data using the SPARQL query language. Whilst this work has proved useful in its own right as one of the first major resources in these disciplines, its utility could be greatly improved by the application of an ontology for annotation of the nodes and edges in the RDF graph, enabling a much richer range of semantic queries to be issued. We developed a generalized chemogenomics and systems chemical biology OWL ontology called Chem2Bio2OWL that describes the semantics of chemical compounds, drugs, protein targets, pathways, genes, diseases and side-effects, and the relationships between them. The ontology also includes data provenance. We used it to annotate our Chem2Bio2RDF dataset, making it a rich semantic resource. Through a series of scientific case studies we demonstrate how this (i) simplifies the process of building SPARQL queries, (ii) enables useful new kinds of queries on the data and (iii) makes possible intelligent reasoning and semantic graph mining in chemogenomics and systems chemical biology. Chem2Bio2OWL is available at http://chem2bio2rdf.org/owl. The document is available at http://chem2bio2owl.wikispaces.com.

  15. New trends and developments in radiation chemistry

    International Nuclear Information System (INIS)

    1989-10-01

    Radiation chemistry is a branch of chemistry that studies chemical transformations in materials exposed to high-energy radiations. It uses radiation as the initiator of chemical reactions. Practical applications of radiation chemistry today extend to many fields, including health care, food and agriculture, manufacturing, industrial pollution abatement, biotechnology and telecommunications. The important advantage of radiation chemistry lies in its ability to be used to produce, and study, almost any reactive atomic and molecular species playing a part in chemical reactions, synthesis, industrial processes, or in biological systems. The techniques are applicable to gaseous, liquid, solid, and heterogeneous systems. By combining different techniques of radiation chemistry with analytical chemistry, the reaction mechanism and kinetics of chemical reactions are studied. In November 1988 in Bologna, Italy, the IAEA convened an advisory group meeting to assess new trends and developments in radiation chemistry. The present publication includes most of the contributions presented at the meeting. Refs, figs and tabs

  16. Biological effects of radiation in combination with other physical, chemical or biological agents. Annex L

    International Nuclear Information System (INIS)

    1982-01-01

    This Annex considers the combined action of radiation with potentially important environmental conditions. Since there is a scarcity of systematic data on which an analysis of combined effects can be based, this Annex will be more hypothetical and will attempt to suggest definitions, to identify suitable methods of analysis, to select from a large amount of diffuse information the conditions and the data of importance for further consideration and to provide suggestions for future research. For humans in environmental circumstances the UNSCEAR Committee has been unable to document any clear case of synergistic interaction between radiation and other agents, which could lead to substantial modifications of the risk estimates for significant sections of the population.

  17. Gamma-irradiated onions as a biological indicator of radiation dose

    International Nuclear Information System (INIS)

    Vaijapurkar, S.G.; Agarwal, Deepshikha; Chaudhuri, S.K.; Ram Senwar, Kana; Bhatnagar, P.K.

    2001-01-01

    Post-irradiation identification and dose estimation are required to assess the radiation-induced effects on living things in any nuclear emergency. In this study, radiation-induced morphological/cytological changes i.e., number of root formation and its length, shooting length, reduction in mitotic index, micronuclei formation and chromosomal aberrations in the root tip cells of gamma-irradiated onions at lower doses (50-2000 cGy) are reported. The capabilities of this biological species to store the radiation-induced information are also studied

  18. Proceedings of the 4. International Symposium on Radiation Physics - Abstracts

    International Nuclear Information System (INIS)

    1988-01-01

    The studies on: fundamental processes in radiation physics; radiation sources and detectors; physical, chemical and biological radiation effects; plasma technology; radioisotope application in medicine and agriculture; environment; use of radiation in material science and; reactor technology, are presented. (M.C.K.) [pt

  19. RESEARCH OF LINEAR AND NONLINEAR PROCESSES AT FEMTOSECOND LASER RADIATION PROPAGATION IN THE MEDIUM SIMULATING THE HUMAN EYE VITREOUS

    Directory of Open Access Journals (Sweden)

    P. Y. Rogov

    2015-09-01

    Full Text Available The paper deals with mathematical model of linear and nonlinear processes occurring at the propagation of femtosecond laser pulses in the vitreous of the human eye. Methods of computing modeling are applied for the nonlinear spectral equation solution describing the dynamics of a two-dimensional TE-polarized radiation in a homogeneous isotropic medium with cubic fast-response nonlinearity without the usage of slowly varying envelope approximation. Environments close to the optical media parameters of the eye were used for the simulation. The model of femtosecond radiation propagation takes into account the process dynamics for dispersion broadening of pulses in time and the occurence of the self-focusing near the retina when passing through the vitreous body of the eye. Dependence between the pulse duration on the retina has been revealed and the duration of the input pulse and the values of power density at which there is self-focusing have been found. It is shown that the main mechanism of radiation damage with the use of titanium-sapphire laser is photoionization. The results coincide with those obtained by the other scientists, and are usable for creation Russian laser safety standards for femtosecond laser systems.

  20. Radiation-induced free radicals in DNA studied by electron paramagnetic resonance

    International Nuclear Information System (INIS)

    Graeslund, A.

    1974-01-01

    Radiation biology aims at an understanding of the effects of radiation on biological material. The studied systems may vary in complexity and size from a whole organism to the molecular constituents of a cell. The observed effects are accordingly varied, from visible somatic effects on the organism to physico-chemical molecular changes. Radiation biophysics may be considered as a specialized branch of radiation biology, dealing with physical aspects of radiation damage, particularly at a molecular or sub-cellular level. The work to be presented here is in the field of radiation biophysics, and concerns physical studies of radiation effects on deoxyribonucleic acid, DNA, the hereditary substance of all living organisms. (author)

  1. Multiplied effect of heat and radiation in chemical stress relaxation

    International Nuclear Information System (INIS)

    Ito, Masayuki

    1981-01-01

    About the deterioration of rubber due to radiation, useful knowledge can be obtained by the measurement of chemical stress relaxation. As an example, the rubber coating of cables in a reactor containment vessel is estimated to be irradiated by weak radiation at the temperature between 60 and 90 deg C for about 40 years. In such case, it is desirable to establish the method of accelerated test of the deterioration. The author showed previously that the law of time-dose rate conversion holds in the case of radiation. In this study, the chemical stress relaxation to rubber was measured by the simultaneous application of heat and radiation, and it was found that there was the multiplied effect of heat and radiation in the stress relaxation speed. Therefore the factor of multiplication of heat and radiation was proposed to describe quantitatively the degree of the multiplied effect. The chloroprene rubber used was offered by Hitachi Cable Co., Ltd. The experimental method and the results are reported. The multiplication of heat and radiation is not caused by the direct cut of molecular chains by radiation, instead, it is based on the temperature dependence of various reaction rates at which the activated species reached the cut of molecular chains through complex reaction mechanism and the temperature dependence of the diffusion rate of oxygen in rubber. (Kako, I.)

  2. Environmental parameters of the Tennessee River in Alabama. 2: Physical, chemical, and biological parameters. [biological and chemical effects of thermal pollution from nuclear power plants on water quality

    Science.gov (United States)

    Rosing, L. M.

    1976-01-01

    Physical, chemical and biological water quality data from five sites in the Tennessee River, two in Guntersville Reservoir and three in Wheeler Reservoir were correlated with climatological data for three annual cycles. Two of the annual cycles are for the years prior to the Browns Ferry Nuclear Power Plant operations and one is for the first 14 months of Plant operations. A comparison of the results of the annual cycles indicates that two distinct physical conditions in the reservoirs occur, one during the warm months when the reservoirs are at capacity and one during the colder winter months when the reservoirs have been drawn-down for water storage during the rainy months and for weed control. The wide variations of physical and chemical parameters to which the biological organisms are subjected on an annual basis control the biological organisms and their population levels. A comparison of the parameters of the site below the Power plant indicates that the heated effluent from the plant operating with two of the three reactors has not had any effect on the organisms at this site. Recommendations given include the development of prediction mathematical models (statistical analysis) for the physical and chemical parameters under specific climatological conditions which affect biological organisms. Tabulated data of chemical analysis of water and organism populations studied is given.

  3. Impact of Theoretical Chemistry on Chemical and Biological Sciences

    Indian Academy of Sciences (India)

    IAS Admin

    theory as applied to biological systems. ... methods to follow the course of chemical reactions devised by. K Fukui and R .... optimize the structure of organic molecules using classical-em- pirical potential ..... science or engineering dis- ciplines.

  4. Ionizing radiation - one of the most important link of the energetic chain in biological cell

    Energy Technology Data Exchange (ETDEWEB)

    Goraczko, W. [Technical Univ. Poznan, Radio- and Photochemistry Dept., Poznan (Poland)

    1999-09-01

    High (large) and low (small) doses of ionizing radiation consistently induce opposite physiologic effects in biological systems. The effects of low doses cannot be inferred by interpolation between the result from groups exposed to high doses and controls irradiated only by Natural Background Radiation. Stimulation ('bio-positive') effects by low-level doses of ionizing radiation are called radiation hormesis. It is still controversial idea, however it was found that some biological objects (yeast, seeds, animals) after gamma irradiation by low-level doses (10-50 times more NBR) can increase their development. The result of present researches demonstrate that the excitation of living system by gamma quanta (high energy) initiates prolonged secondary emission that influences biota and activates many important processes in biological systems. According to the excitation theory of bio-molecules the author suggests that gamma irradiation in low-level doses excites such molecules as DNA and proteins, and this being followed by a long-termed secondary coherent radiation. The spectral analysis of this secondary emission confirmed the contribution of the UV component to the total emission. The data obtaining by using SPC method (single photon counting) make possible a partial understanding of the radiation hormesis phenomenon and suggest closer relationship to UV emission from biological systems during mitotic processes. The experiments with humic acid (high doses) and glycine (low doses) confirm the author hypothesis that gamma-irradiated organic compounds are capable to emit secondary radiation. This secondary radiation probably plays very significant role in the intercellular communication inside the living systems. In conclusion the author proposed de-excitation processes in bio-molecules as a common denominator of UV and ionizing radiation interacting with living cells. Finally he refers to the Cerenkov radiation which is created inside the biological cells

  5. Ionizing radiation - one of the most important link of the energetic chain in biological cell

    International Nuclear Information System (INIS)

    Goraczko, W.

    1999-01-01

    High (large) and low (small) doses of ionizing radiation consistently induce opposite physiologic effects in biological systems. The effects of low doses cannot be inferred by interpolation between the result from groups exposed to high doses and controls irradiated only by Natural Background Radiation. Stimulation ('bio-positive') effects by low-level doses of ionizing radiation are called radiation hormesis. It is still controversial idea, however it was found that some biological objects (yeast, seeds, animals) after gamma irradiation by low-level doses (10-50 times more NBR) can increase their development. The result of present researches demonstrate that the excitation of living system by gamma quanta (high energy) initiates prolonged secondary emission that influences biota and activates many important processes in biological systems. According to the excitation theory of bio-molecules the author suggests that gamma irradiation in low-level doses excites such molecules as DNA and proteins, and this being followed by a long-termed secondary coherent radiation. The spectral analysis of this secondary emission confirmed the contribution of the UV component to the total emission. The data obtaining by using SPC method (single photon counting) make possible a partial understanding of the radiation hormesis phenomenon and suggest closer relationship to UV emission from biological systems during mitotic processes. The experiments with humic acid (high doses) and glycine (low doses) confirm the author hypothesis that gamma-irradiated organic compounds are capable to emit secondary radiation. This secondary radiation probably plays very significant role in the intercellular communication inside the living systems. In conclusion the author proposed de-excitation processes in bio-molecules as a common denominator of UV and ionizing radiation interacting with living cells. Finally he refers to the Cerenkov radiation which is created inside the biological cells. Because

  6. Radiochemical problems of radiation chemical synthesis in n, γ-field of nuclear reactor

    International Nuclear Information System (INIS)

    Mironov, V.P.; Frejdus, N.V.; Bugaenko, L.T.; Kalyazin, E.P.; Petryaev, E.P.

    1981-01-01

    A wide applicability of products of radiation chemical synthesis (RCS), using n, γ-irradiation, is limited by possible contamination of the latter with long-lived radioactive isotopes of chemical elements included in the composition of the reagent and compounds syntesized (chemically non-separable radionuclides - CNR). A technique of the determination of the limit accumulation CNR on the basis of radiation chemical parameters of the synthesis (radiation-chemical yield, the dose rate absorbed, singleness of purpose of RCS etc.) and radiochemical parameters of formation and accumulation of CNR (radiochemical yields of CNR in the products of radiolysis, neutron fluence, the reagent purity etc.) is suggested. The radiochemical evaluation of CNR accumulation (tritium and carbon-14), formed at the expense of activation with neutrons of chemical elements of water and organic substances, consisting of hydrogen, carbon and oxygen has shown that at relatively low yields of final products (> or approximately 3 molecules/100 eV) no accumulation of radionuclides in concentrations reaching the average admissible concentration takes place [ru

  7. Microbiology and atmospheric processes: biological, physical and chemical characterization of aerosol particles

    Directory of Open Access Journals (Sweden)

    D. G. Georgakopoulos

    2009-04-01

    Full Text Available The interest in bioaerosols has traditionally been linked to health hazards for humans, animals and plants. However, several components of bioaerosols exhibit physical properties of great significance for cloud processes, such as ice nucleation and cloud condensation. To gain a better understanding of their influence on climate, it is therefore important to determine the composition, concentration, seasonal fluctuation, regional diversity and evolution of bioaerosols. In this paper, we will review briefly the existing techniques for detection, quantification, physical and chemical analysis of biological particles, attempting to bridge physical, chemical and biological methods for analysis of biological particles and integrate them with aerosol sampling techniques. We will also explore some emerging spectroscopy techniques for bulk and single-particle analysis that have potential for in-situ physical and chemical analysis. Lastly, we will outline open questions and further desired capabilities (e.g., in-situ, sensitive, both broad and selective, on-line, time-resolved, rapid, versatile, cost-effective techniques required prior to comprehensive understanding of chemical and physical characterization of bioaerosols.

  8. Non-ionizing radiations : physical characteristics, biological effects and health hazard assessment

    International Nuclear Information System (INIS)

    Repacholi, M.H.

    1988-01-01

    The Workshop was a project of the International Non-Ionizing Radiation Committee of IRPA and comprised a series of educational lectures and demonstrations intended to give a comprehensive overview of non-ionizing electromagnetic radiation: physical characteristics, sources of concern, levels of exposure, mechanisms of interaction and reported effects of these fields and radiations with biological tissues, human studies, health risk assessment, national and international standards and guidelines, and protective measures

  9. Weapons of mass destruction: Overview of the CBRNEs (Chemical, Biological, Radiological, Nuclear, and Explosives).

    Science.gov (United States)

    Prockop, Leon D

    2006-11-01

    The events of September 11, 2001, made citizens of the world acutely aware of disasters consequent to present-day terrorism. This is a war being waged for reasons obscure to many of its potential victims. The term "NBCs" was coined in reference to terrorist weapons of mass destruction, i.e., nuclear, biological and chemical. The currently accepted acronym is "CBRNE" which includes Chemical, Biological, Radiological, Nuclear, and Explosive weapons. Non-nuclear explosives are the most common terrorist weapon now in use. Nuclear and radiological weapons are beyond the scope of this publication, which focuses on the "CBEs", i.e. chemical, biological and explosive weapons. Although neurologists will not be the first responders to CBEs, they must know about the neurological effects in order to provide diagnosis and treatment to survivors. Neurological complications of chemical, biological and explosive weapons which have or may be used by terrorists are reviewed by international experts in this publication. Management and treatment profiles are outlined.

  10. On propagation of radiation in crystals

    International Nuclear Information System (INIS)

    Buzek, V.; Grigorijev, V.I.

    1984-11-01

    The description of the propagation of the photons in the crystal is given in the framework of a quantum field-theoretical model that can be solved exactly. Besides this, the quantum version of the Ewald-Oseen extinction theorem is proved. (author)

  11. A Review: Some biological effects of high LET radiations

    Science.gov (United States)

    Wiley, A., Jr.

    1972-01-01

    There are qualitative and quantitative differences in the biological damage observed after exposure to high LET radiation as compared to that caused by low LET radiations. This review is concerned with these differences, which are ultimately reflected at the biochemical, cellular and even whole animal levels. In general, high LET radiations seem to produce biochemical damage which is more severe and possibly less repairable. Experimental data for those effects are presented in terms of biochemical RBE's with consideration of both early and late manifestations. An LET independent process by which significant biochemical damage may result from protons, neutrons and negative pion mesons is discussed.

  12. Protection against genetic hazards from environmental chemical mutagens: experience with ionizing radiation

    International Nuclear Information System (INIS)

    Sankaranarayanan, K.

    1977-01-01

    In radiation protection, the recurrent theme is, and always has been, dose limitation whether it is for occupational workers, individual members of the public or the population as a whole. The key words are 'dose' and 'limitation'. The quantitative system of dose limitation has been achieved because of a number of conceptual developments in our understanding of the mechanism of radiation action, development of radiation dosimetry, the accumulation of a vast body of quantitative information on dose-effect relationships and the effects of various biological and physical variables that affect these relationships of data on patterns and levels of exposures likely to be encountered to make estimates of the effects expected to result from such exposures, and balancing of risks to society against the benefits derived, the latter a matter of informed judgement. The philosophy has always been to avoid all unnecessary exposures and to limit the necessary exposures (justified by the benefits expected) to as low a level as reasonably achievable, social and economic factors being taken into acccount. The introduction of the concept that the system of dose limitation to the population should be based on genetic risks has stressed the need for careful planning to ensure that our genetic heritage is not endangered. Transfer of this knowledge to the field of chemical protection is discussed. (Auth.)

  13. Improving integrative searching of systems chemical biology data using semantic annotation

    Directory of Open Access Journals (Sweden)

    Chen Bin

    2012-03-01

    Full Text Available Abstract Background Systems chemical biology and chemogenomics are considered critical, integrative disciplines in modern biomedical research, but require data mining of large, integrated, heterogeneous datasets from chemistry and biology. We previously developed an RDF-based resource called Chem2Bio2RDF that enabled querying of such data using the SPARQL query language. Whilst this work has proved useful in its own right as one of the first major resources in these disciplines, its utility could be greatly improved by the application of an ontology for annotation of the nodes and edges in the RDF graph, enabling a much richer range of semantic queries to be issued. Results We developed a generalized chemogenomics and systems chemical biology OWL ontology called Chem2Bio2OWL that describes the semantics of chemical compounds, drugs, protein targets, pathways, genes, diseases and side-effects, and the relationships between them. The ontology also includes data provenance. We used it to annotate our Chem2Bio2RDF dataset, making it a rich semantic resource. Through a series of scientific case studies we demonstrate how this (i simplifies the process of building SPARQL queries, (ii enables useful new kinds of queries on the data and (iii makes possible intelligent reasoning and semantic graph mining in chemogenomics and systems chemical biology. Availability Chem2Bio2OWL is available at http://chem2bio2rdf.org/owl. The document is available at http://chem2bio2owl.wikispaces.com.

  14. Progress in hprt mutation assay and its application in radiation biology

    International Nuclear Information System (INIS)

    He Jing; Li Qiang

    2008-01-01

    hprt gene is an X-linked locus that has been well studied and widely used as a bio-marker in mutation detection, hprt mutation assay is a gene mutation test system in mammalian cells in vitro which has been used as a biological dosimeter. In this paper, the biological characteristics of hprt gene, hprt mutation detection methodology and the application of hprt mutation assay in radiation biology are comprehensively reviewed. (authors)

  15. Natural radiation, radioactive waste and chemical risk determinants

    International Nuclear Information System (INIS)

    Christensen, T.; Mustonen, R.; Edhwall, H.; Hansen, H.; Soerensen, A.; Stranden, E.

    1990-01-01

    Doses from natural radiation to the population in the Nordic countries are summarized, and man-made modifications of the natural radiation environment are discussed. An account is given for the radiological concequences of energy concervation by reduced ventilation. Risks from possible future releases of radioactivity from final depositories of spent nuclear fuel are compared to the risks from present natural radioactivity in the environment. The possibilities for comparison between chemical and radiological risks are discussed. 104 refs., 36 figs., 47 tabs

  16. A review of the biological and clinical aspects of radiation caries.

    Science.gov (United States)

    Aguiar, Gabrielle P; Jham, Bruno C; Magalhães, Cláudia S; Sensi, Luis Guilherme; Freire, Addah R

    2009-07-01

    The aim of this article is to review the clinical and biological features underlying the development and progression of radiation caries. Although radiotherapy (RT) plays an important role in the management of patients with head and neck cancer (HNC), it is also associated with several undesired side effects such as radiation caries which is a common, yet serious, complication. To review the condition, the Pubmed database was searched using the keywords "radiotherapy," "radiation," "caries," "hyposalivation," "prevention" and "management". Only studies published in the English language were selected. Cross-referencing identified additionally relevant studies. RT leads to alterations in the dentition, saliva, oral microflora, and diet of patients. Consequently, irradiated patients are at increased risk for the development of a rapid, rampant carious process known as radiation caries. Motivation of patients, adequate plaque control, stimulation of salivary flow, fluoride use, and nutritional orientation are essential to reduce the incidence of radiation caries and ultimately improve the quality of life for HNC patients. Radiation caries is an aggressive side effect of RT. Dentists play an important role in the prevention of the condition via comprehensive oral healthcare before, during, and after the active cancer therapy. Dentists should understand the clinical and biological aspects underlying radiation caries to prevent the development of lesions and provide optimal treatment when needed.

  17. Exploration of the central dogma at the interface of chemistry and biology: 2010 Yale Chemical Biology Symposium.

    Science.gov (United States)

    Zhou, Alice Qinhua

    2010-09-01

    Ever since the term "central dogma" was coined in 1958, researchers have sought to control information flow from nucleic acids to proteins. Talks delivered by Drs. Anna Pyle and Hiroaki Suga at this year's Chemical Biology Symposium at Yale in May 2010 applauded recent advances in this area, at the interface between chemistry and biology.

  18. Studies on the Promotion of Biological Application by Radiation

    International Nuclear Information System (INIS)

    No, Y. C.; Kuk, I. H.; Song, H. S.

    2006-03-01

    Radiation Technology (RT) has been widely used in most of all fields of industries, medical, bioresources, food and agriculture, public hygiene, and environment. Therefore, its application has been also researched in various parts. For industrialization of the developed technology, not only the application technology will be developed, but the accurate dosimetry and improvement of the services of irradiation practice should be performed as soon as possible. Evaluation of effects and reaction mechanism of biological materials by irradiation was performed in this year in the long term research planning. The researches and experiments were well performed and the good results were obtained. The results may be donated in the progress of radiation biology and the new establishment on the application of RT. Also, one of the results was the evaluation of the structural changes of biomolecules and its application in the fields of food and biotechnology industries. Advanced Radiation Technology Institute (ARTI) will be well settled down and promotion of research activity of newly established institute by the fundamental support of KAERI. And, ARTI can get the goal where the vision of the hub of RT in Asia/Pacific region by 2020

  19. Prophylactic measures of radiation injuries by natural herbs and neutraceuticals

    Energy Technology Data Exchange (ETDEWEB)

    Goyal, P.K., E-mail: pkgoyal2002@gmail.com [Radiation and Cancer Biology Laboratory, Department of Zoology, University of Rajasthan, Jaipur (India)

    2014-07-01

    The application of radiation biology has gained greater relevance and significance in health and environmental issues. In the present time, nuclear terrorism and weapon related effects are raising much alarm and concern to public health. Obviously, radiation biology research has great potential in diagnosis, therapy and establishing standards for assessment risk from radiation exposure. The development of effective medical countermeasures against nuclear biological and chemical weapons is of immense importance to the defense of all nations and especially to those threatened by international terrorism. Chemical radiation protection is an important strategy to protect living being against deleterious effects of radiation. Earlier the synthetic chemical substances, which could minimize the pathological changes in the living system after exposure to ionizing radiation, were looked into. Medicinal plants are the local heritage with global importance. World is enclosed with a rich wealth of medicinal plants. Herbs have always been the principle form of medicine in India and presently they become popular. Over the last few years, interest in evaluating oriental medicinal herbs and edible phyto products for the use in anti-radiation strategies is encouraging and emerging as an acceptable approach for preventing the radiation induced lesions in many countries. Several Indian medicinal plants (Emblica officinalis, Rosemarinus officinalis, Trigonella foenum-graecum, Alstonia scholaris, Tinospora cordifolia, Phyllanthus niruri, Syzygium cumini, Aegle marmelos, Panax ginseng, Linum usitatissimum, Delonix regia etc) and antioxidant vitamins (C and E) have been tested in this laboratory by taking various biological end points for the possible use of natural products and phytochemicals to serve as radio protectors for medical countermeasures against radiation injuries, and the results obtained from such studies are highly encouraging and fruitful. It opens new avenues for the

  20. Prophylactic measures of radiation injuries by natural herbs and neutraceuticals

    International Nuclear Information System (INIS)

    Goyal, P.K.

    2014-01-01

    The application of radiation biology has gained greater relevance and significance in health and environmental issues. In the present time, nuclear terrorism and weapon related effects are raising much alarm and concern to public health. Obviously, radiation biology research has great potential in diagnosis, therapy and establishing standards for assessment risk from radiation exposure. The development of effective medical countermeasures against nuclear biological and chemical weapons is of immense importance to the defense of all nations and especially to those threatened by international terrorism. Chemical radiation protection is an important strategy to protect living being against deleterious effects of radiation. Earlier the synthetic chemical substances, which could minimize the pathological changes in the living system after exposure to ionizing radiation, were looked into. Medicinal plants are the local heritage with global importance. World is enclosed with a rich wealth of medicinal plants. Herbs have always been the principle form of medicine in India and presently they become popular. Over the last few years, interest in evaluating oriental medicinal herbs and edible phyto products for the use in anti-radiation strategies is encouraging and emerging as an acceptable approach for preventing the radiation induced lesions in many countries. Several Indian medicinal plants (Emblica officinalis, Rosemarinus officinalis, Trigonella foenum-graecum, Alstonia scholaris, Tinospora cordifolia, Phyllanthus niruri, Syzygium cumini, Aegle marmelos, Panax ginseng, Linum usitatissimum, Delonix regia etc) and antioxidant vitamins (C and E) have been tested in this laboratory by taking various biological end points for the possible use of natural products and phytochemicals to serve as radio protectors for medical countermeasures against radiation injuries, and the results obtained from such studies are highly encouraging and fruitful. It opens new avenues for the

  1. Propagation of microwaves in pulsar magnetospheres

    Energy Technology Data Exchange (ETDEWEB)

    Bodo, G; Ferrari, A [Turin Univ. (Italy). Ist. di Fisica Generale; Consiglio Nazionale delle Ricerche, Turin (Italy). Lab. di Cosmo-Geofisica); Massaglia, S [Turin Univ. (Italy). Ist. di Fisica Generale; Cambridge Univ. (UK). Inst. of Astronomy)

    1981-12-01

    We discuss the dispersion relation of linearly-polarized waves, propagating along a strong background magnetic field embedded in an electron-positron plasma. The results are then applied to the study of the propagation conditions of coherent curvature radio radiation inside neutron stars magnetospheres, as produced by electric discharges following current pulsar models.

  2. Biological effects and medical applications of infrared radiation.

    Science.gov (United States)

    Tsai, Shang-Ru; Hamblin, Michael R

    2017-05-01

    Infrared (IR) radiation is electromagnetic radiation with wavelengths between 760nm and 100,000nm. Low-level light therapy (LLLT) or photobiomodulation (PBM) therapy generally employs light at red and near-infrared wavelengths (600-100nm) to modulate biological activity. Many factors, conditions, and parameters influence the therapeutic effects of IR, including fluence, irradiance, treatment timing and repetition, pulsing, and wavelength. Increasing evidence suggests that IR can carry out photostimulation and photobiomodulation effects particularly benefiting neural stimulation, wound healing, and cancer treatment. Nerve cells respond particularly well to IR, which has been proposed for a range of neurostimulation and neuromodulation applications, and recent progress in neural stimulation and regeneration are discussed in this review. The applications of IR therapy have moved on rapidly in recent years. For example, IR therapy has been developed that does not actually require an external power source, such as IR-emitting materials, and garments that can be powered by body heat alone. Another area of interest is the possible involvement of solar IR radiation in photoaging or photorejuvenation as opposites sides of the coin, and whether sunscreens should protect against solar IR? A better understanding of new developments and biological implications of IR could help us to improve therapeutic effectiveness or develop new methods of PBM using IR wavelengths. Copyright © 2016. Published by Elsevier B.V.

  3. Documentation on UV-C radiation and its biological, chemical and physical effect on microorganisms

    International Nuclear Information System (INIS)

    Ohlenbostel, B.; Weigand, F.

    Trying to esplain the laws of radiation Max Planck in 1901 found the important relation E = h ν. E is the energy of the radiation quanta or photons, a conception formed by Einstein expressing the corpuscular character of radiation. h is the socalled Planck's constant, a universal constant with h = 6.625 x 10 -34 Js, and ν is the frequency Beside this conception there excitis a wave-theoretical conception of radiation which can be described by the formula c = ν lambda. In this equation is the velocity of light and lambda is the wavelength. Because of this dual character one talks of a wave-particle dualism of the electromagnetic radiation. The total range if this radiation whose appearance is only distinguished by wavelength extends from the most energetic γ rays through X rays, ultraviolet, visible and infrared radiation to the electric waves. (orig.) [de

  4. First picosecond in radiation chemistry

    International Nuclear Information System (INIS)

    Bednar, J.

    1983-01-01

    The early processes of absorption by matter of ionizing radiation are discussed on the level of collision processes of electrons of the degradation spectrum of radiation with molecules of the medium. A short survey of the processes of initial excitations, superexcitations and ionizations is given occurring during absorption and relaxation processes. Collisions of fast charged particles with atoms and molecules are discussed within the first Bethe-Born approximation. A short theoretical description is given of the basic radiation chemical quantities, such as primary radiation chemical yield g and total absorbed energy Q/sub tot/ due to energy absorption from the totality of fast and slow electrons of the degradation spectrum. A short survey of current chemical and physical models of the track of a fast electron in condensed media is given together with some comments on the effect of the chemical composition of the medium on its initial radiation chemical decomposition. The model of the molecule in a high Rydberg state is sketched briefly together with some implications for radiation chemistry of formation and decay of this kind of highly excited matter. In conclusion, a survey of the initial yields of products in gases and track entities in liquids is presented and a few remarks are made concerning the intrinsic problems of radiation sciences, i.e. radiation physics, chemistry, dosimetry and biology

  5. Quantification of ultraviolet photon emission from interaction of charged particles in materials of interest in radiation biology research

    Energy Technology Data Exchange (ETDEWEB)

    Ahmad, Syed Bilal, E-mail: ahmadsb@mcmaster.ca [Department of Medical Physics and Applied Radiation Sciences, University of McMaster, Hamilton, ON (Canada); Department of Physics and Applied Mathematics, Pakistan Institute of Engineering and Applied Sciences, Islamabad (Pakistan); McNeill, Fiona E., E-mail: fmcneill@mcmaster.ca [Department of Medical Physics and Applied Radiation Sciences, University of McMaster, Hamilton, ON (Canada); Prestwich, William V., E-mail: prestwic@mcmaster.ca [Department of Medical Physics and Applied Radiation Sciences, University of McMaster, Hamilton, ON (Canada); Byun, Soo Hyun, E-mail: soohyun@mcmaster.ca [Department of Medical Physics and Applied Radiation Sciences, University of McMaster, Hamilton, ON (Canada); Seymour, Colin, E-mail: seymouc@mcmaster.ca [Department of Medical Physics and Applied Radiation Sciences, University of McMaster, Hamilton, ON (Canada); Mothersill, Carmel E., E-mail: mothers@mcmaster.ca [Department of Medical Physics and Applied Radiation Sciences, University of McMaster, Hamilton, ON (Canada)

    2014-01-15

    In radiation biology experiments often cells are irradiated using charged particles with the intention that only a specified number of cells are hit by the primary ion track. However, in doing so several other materials such as the cell container and the growth media etc. are also irradiated, and UV radiation emitted from these materials can potentially interact with the cells. We have hypothesized that some “bystander effects” that are thought to be chemically mediated, may be, in fact, a physical effect, where UV is interacting with non-targeted cells. Based upon our hypothesis we quantified the emission of UV from Polypropylene, Mylar, Teflon, and Cellophane which are all commonly used materials in radiation biology experiments. Additionally we measured the NIST standard materials of Oyster tissue and Citrus leaves as these powdered materials are derived from living cells. Protons accelerated up to an energy of 2.2 MeV, in a 3 MV Van de Graff accelerator, were used for irradiation. Beam current was kept to 10 nA, which corresponds to a proton fluence rate of 2.7 × 10{sup 10} protons mm{sup −2} s{sup −1}. All the materials were found to emit light at UV frequencies and intensities that were significant enough to conduct a further investigation for their biological consequences. Mylar and polypropylene are commonly used in radiation induced bystander effect studies and are considered to be non-fluorescent. However our study showed that this is not the case. Significant luminescence observed from the irradiated NIST standard reference materials for Oyster tissue and Citrus leaves verified that the luminescence emission is not restricted only to the polymeric materials that are used to contain cells. It can also occur from ion interactions within the cells as well.

  6. Biological and chemical weapons of mass destruction: updated clinical therapeutic countermeasures since 2003.

    Science.gov (United States)

    Pettineo, Christopher; Aitchison, Robert; Leikin, Scott M; Vogel, Stephen N; Leikin, Jerrold B

    2009-01-01

    The objective of this article is to provide updated treatment options for bioterrorism agents. This updated synopsis includes recent clinical cases and treatment recommendations that have arisen in the last 5 years. The decontamination, treatment, and disposition of these biologic and chemical agents are presented alphabetically by agent type: biologic, chemical, and radiologic/nuclear. The information provided outlines only new treatment options since 2003.

  7. Radiation physics, biophysics, and radiation biology. Final report, October 1, 1971--September 30, 1977

    International Nuclear Information System (INIS)

    Rossi, H.H.; Hall, E.J.

    1978-02-01

    Research under Contract EY-76-C-02-3243 has been carried out in the area of Radiation Physics, Biophysics and Radiation Biology. During the period of this contract the major accomplishments include, in Physics, the refinement of tissue equivalent dosimetry, the formulation of the concepts of microdosimetry, the development of apparatus used in microdosimetry, and the development of ionization chambers with internal gas multiplication. Principal contributions in Radiobiology have included the determination of RBE and OER as a function of neutron energy, the study of combined effects of radiation and a variety of other agents, and the investigation of the transformation of cells in tissue culture. Theoretical research centered around the development of the theoretical framework of microdosimetry and the establishment of the Theory of Dual Radiation Action. In a cooperative effort with Brookhaven National Laboratory, a major accelerator facility dedicated exclusively to Radiobiology and Radiation Physics, has been developed. Members of the laboratory have performed extensive service to national and international organizations

  8. DEGRO 2009. Radiation oncology - medical physics - radiation biology. Abstracts; DEGRO 2009. Radioonkologie - Medizinische Physik - Strahlenbiologie. Abstracts

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2009-06-15

    The special volume of the journal covers the abstracts of the DEGRO 2009 meeting on radiation oncology, medical physics, and radiation biology, covering the following topics: seldom diseases, gastrointestinal tumors, radiation reactions and radiation protection, medical care and science, central nervous system, medical physics, the non-parvicellular lung carcinomas, ear-nose-and throat, target-oriented radiotherapy plus ''X'', radio-oncology - young academics, lymphomas, mammary glands, modern radiotherapy, life quality and palliative radiotherapy, radiotherapy of the prostate carcinoma, imaging for planning and therapy, the digital documentation in clinics and practical experiences, NMR imaging and tomography, hadrons - actual status in Germany, urinal tract oncology, radiotoxicity.

  9. Radiation biology for pediatric radiologists

    International Nuclear Information System (INIS)

    Hall, Eric J.

    2009-01-01

    The biological effects of radiation result primarily from damage to DNA. There are three effects of concern to the radiologist that determine the need for radiation protection and the dose principle of ALARA (As Low As Reasonably Achievable). (1) Heritable effects. These were thought to be most important in the 1950s, but concern has declined in recent years. The current ICRP risk estimate is very small at 0.2%/Sv. (2) Effects on the developing embryo and fetus include weight retardation, congenital anomalies, microcephaly and mental retardation. During the sensitive period of 8 to 15 weeks of gestation, the risk estimate for mental retardation is very high at 40%/Sv, but because it is a deterministic effect, there is likely to be a threshold of about 200 mSv. (3) Carcinogenesis is considered to be the most important consequence of low doses of radiation, with a risk of fatal cancer of about 5%/Sv, and is therefore of most concern in radiology. Our knowledge of radiation carcinogenesis comes principally from the 60-year study of the A-bomb survivors. The use of radiation for diagnostic purposes has increased dramatically in recent years. The annual collective population dose has increased by 750% since 1980 to 930,000 person Sv. One of the principal reasons is the burgeoning use of CT scans. In 2006, more than 60 million CT scans were performed in the U.S., with about 6 million of them in children. As a rule of thumb, an abdominal CT scan in a 1-year-old child results in a life-time mortality risk of about one in a thousand. While the risk to the individual is small and acceptable when the scan is clinically justified, even a small risk when multiplied by an increasingly large number is likely to produce a significant public health concern. It is for this reason that every effort should be made to reduce the doses associated with procedures such as CT scans, particularly in children, in the spirit of ALARA. (orig.)

  10. Developing the Biomolecular Screening Facility at the EPFL into the Chemical Biology Screening Platform for Switzerland.

    Science.gov (United States)

    Turcatti, Gerardo

    2014-05-01

    The Biomolecular Screening Facility (BSF) is a multidisciplinary laboratory created in 2006 at the Ecole Polytechnique Federale de Lausanne (EPFL) to perform medium and high throughput screening in life sciences-related projects. The BSF was conceived and developed to meet the needs of a wide range of researchers, without privileging a particular biological discipline or therapeutic area. The facility has the necessary infrastructure, multidisciplinary expertise and flexibility to perform large screening programs using small interfering RNAs (siRNAs) and chemical collections in the areas of chemical biology, systems biology and drug discovery. In the framework of the National Centres of Competence in Research (NCCR) Chemical Biology, the BSF is hosting 'ACCESS', the Academic Chemical Screening Platform of Switzerland that provides the scientific community with chemical diversity, screening facilities and know-how in chemical genetics. In addition, the BSF started its own applied research axes that are driven by innovation in thematic areas related to preclinical drug discovery and discovery of bioactive probes.

  11. Chemical and biological characterization of a crude venom extract ...

    African Journals Online (AJOL)

    Background: Sea-anemones, in common with other members of the phylum cnidaria (coelenterate) possess numerous tentacles containing specialized stinging cells of cnidocysts. Our main objective is to elucidate the chemical character and biological properties of this Nigerian species of sea anemone Bunodosoma ...

  12. Semiclassical theory of electronically nonadiabatic chemical dynamics: Incorporation of the Zhu-Nakamura theory into the frozen Gaussian propagation method

    International Nuclear Information System (INIS)

    Kondorskiy, A.; Nakamura, H.

    2004-01-01

    The title theory is developed by combining the Herman-Kluk semiclassical theory for adiabatic propagation on single potential-energy surface and the semiclassical Zhu-Nakamura theory for nonadiabatic transition. The formulation with use of natural mathematical principles leads to a quite simple expression for the propagator based on classical trajectories and simple formulas are derived for overall adiabatic and nonadiabatic processes. The theory is applied to electronically nonadiabatic photodissociation processes: a one-dimensional problem of H 2 + in a cw (continuous wave) laser field and a two-dimensional model problem of H 2 O in a cw laser field. The theory is found to work well for the propagation duration of several molecular vibrational periods and wide energy range. Although the formulation is made for the case of laser induced nonadiabatic processes, it is straightforwardly applicable to ordinary electronically nonadiabatic chemical dynamics

  13. 5. Conference cycle. The radiations and the Biological Sciences

    International Nuclear Information System (INIS)

    Balcazar G, M.; Chavez B, A.

    1991-06-01

    Nuclear technologies and their development have influenced many aspects of modern life. Besides used for electricity production nuclear technologies are applied in many other fields, especially in biological sciences. In genetics and molecular biology they enable research resulting in increased food production and better food preservation. Usage in material sciences lead to new varieties of plastics or improved characteristics. Nuclear applications are used in pe troleum industries and in forecasting geothermic power. Radiobiology and radiotherapy enable diagnosis and therapy of several diseases, e.g. cancer. Nuclear technologies also contribute to preserve the environment. They offer methods to analyse as well as decrease the environmental impacts. The 5. conference cyle entitled 'The Radiations and the Biological Sciences' aims to inform students of biological sciences about new nuclear technologies applied in their field of interest

  14. Further approaches to biological indicators of radiation injury

    International Nuclear Information System (INIS)

    Koeteles, G.J.; Kormos, C.; Kerekes, J.; Sztanyik, L.B.

    1988-01-01

    Despite of the decades-long investigations, the search for proper biological indicator of radiation injuries did not result in techniques fulfilling all the requirements. So far, the most reliable assay is the dicentric chromosome aberration analysis. New developments have been made recently on a cytogenetic technique, the micronucleus assay, and for local injuries on the application of thermography

  15. Radiation-chemical yields of molecular hydrogen formation in cyclohexane based alcohols

    International Nuclear Information System (INIS)

    Val'ter, A.I.; Kovalev, G.V.

    1988-01-01

    Molecular hydrogen radiation-chemical yields in γ-irradiated cyclohexanol, 1.2-cis- and 1.2-trans-cyclohexandiols and inositol are determined within the general problem frameworks of radiolysis mechanism for cyclohexanering-base alcohols. Irradiation was conducted at 77 and 293 K, dose rate - 4 Gy/s. Hydrogen concentration in all irradiated alcohols depends linearly on the dose. Radiation-chemical yields of H 2 and of stabilized radicals, as well, in the irradiated crystalline alcohols are analyzed depending on the irradiation temperature, alcohol molecular structure

  16. Essential Oils from Thyme (Thymus vulgaris): Chemical Composition and Biological Effects in Mouse Model.

    Science.gov (United States)

    Vetvicka, Vaclav; Vetvickova, Jana

    2016-12-01

    Thymus species are popular spices and contain volatile oils as main chemical constituents. Recently, plant-derived essential oils are gaining significant attention due to their significant biological activities. Seven different thymus-derived essential oils were compared in our study. First, we focused on their chemical composition, which was followed up by testing their effects on phagocytosis, cytokine production, chemotaxis, edema inhibition, and liver protection. We found limited biological activities among tested oils, with no correlation between composition and biological effects. Similarly, no oils were effective in every reaction. Based on our data, the tested biological use of these essential oils is questionable.

  17. Flow cytometric life cycle analysis in cellular radiation biology

    International Nuclear Information System (INIS)

    Wood, J.C.S.

    1982-01-01

    Three approaches to flow cytometric histogram analysis were developed: (1) differential histogram analysis, (2) DNA histogram analysis, and (3) multiparameter data analysis. These techniques were applied to an important unresolved problem in radiation biology. The initial responses to irradiation of a mammalian cell which occur during the first two cell cycles following the irradiation are of considerable interest to the radiation biologist. During the first two post-irradiation cell cycles, cells which ultimately will survive repair radiation-induced damage, while some cells begin to express some of the radiation-induced nuclear and chomatin damage. Caffeine- and thymidine-treated, and untreated gamma-irradiated cell populations were studied with respect to the radiation-induced G2 delay, deficient DNA synthesis, and the appearance of cells with abnormal DNA contents. It is hypothesized that the measured deficiency in DNA synthesis observed in the first post-irradiation cell cycle may be a result of daughter cells from abnormal first post-irradiation mitoses

  18. Physics fundamentals and biological effects of synchrotron radiation therapy

    International Nuclear Information System (INIS)

    Prezado, Y.

    2010-01-01

    The main goal of radiation therapy is to deposit a curative dose in the tumor without exceeding the tolerances in the nearby healthy tissues. For some radioresistant tumors, like gliomas, requiring high doses for complete sterilization, the major obstacle for curative treatment with ionizing radiation remains the limited tolerance of the surrounding healthy tissue. This limitation is particularly severe for brain tumors and, especially important in children, due to the high risk of complications in the development of the central nervous system. In addition, the treatment of tumors close to an organ at risk, like the spinal cord, is also restricted. One possible solution is the development of new radiation therapy techniques exploiting radically different irradiation modes and modifying, in this way, the biological equivalent doses. This is the case of synchrotron radiation therapy (SRT). In this work the three new radiation therapy techniques under development at the European Synchrotron Radiation Facility (ESRF), in Grenoble (France) will be described, namely: synchrotron stereotactic radiation therapy (SSRT), microbeam radiation therapy (MRT) and minibeam radiation therapy. The promising results in the treatment of the high grade brain tumors obtained in preclinical studies have paved the way to the clinical trials. The first patients are expected in the fall of 2010. (Author).

  19. Biology panel: coming to a clinic near you. Translational research in radiation biology

    International Nuclear Information System (INIS)

    Travis, Elizabeth L.; Thames, Howard D.

    1996-01-01

    The explosion of knowledge in molecular biology coupled with the rapid and continuing development of molecular techniques allow a new level of research in radiation biology aimed at understanding the processes that govern radiation damage and response in both tumors and normal tissues. The challenge to radiation biologists and radiation oncologists is to use this knowledge to improve the therapeutic ratio in the management of human tumors by rapidly translating these new findings into clinical practice. This panel will focus on both sides of the therapeutic ratio coin, the manipulation of tumor control by manipulating the processes that control cell cycle regulation and apoptosis, and the reduction of normal tissue morbidity by applying the emerging information on the genetic basis of radiosensitivity. Apoptosis is a form of cell death believed to represent a minor component of the clinical effects of radiation. However, if apoptosis is regulated by anti-apoptotic mechanisms, then it may be possible to produce a pro-apoptotic phenotype in the tumor cell population by modulating the balance between pro- and anti-apoptotic mechanisms by pharmacological intervention. Thus signaling-based apoptosis therapy, designed to overcome the relative resistance to radiation-induced apoptosis, may improve the therapeutic ratio in the management of human tumors. The explosion of information concerning cell cycle regulation in both normal and tumor cells has provided the opportunity for insights into the mechanism of action of chemotherapeutic agents that can act as radiosensitizers. The second talk will explore the hypothesis that the dysregulation of cell cycle checkpoints in some cancers can be exploited to improve the therapeutic index of radiation sensitizers, specifically the fluoropyrimidines which appear to act at the G1/S transition. Finally, efforts to increase tumor control will be translated into clinical practice only if such treatments do not increase the complication

  20. Part 6: Modelling of simultaneous chemical-biological P removal ...

    African Journals Online (AJOL)

    drinie

    approaches taken in modelling the chemical P removal processes. In the literature .... to 2 mgP/l) for an iron dose of ~1 to 10 mg/l as Fe - refer to dashed line in Fig. 1). ...... systems exhibiting biological enhanced phosphate removal. Part 3:.