Radiation Dosage: The amount of radiation energy that is deposited in a unit mass of material, such as tissues of plants or animal. In RADIOTHERAPY, radiation dosage is expressed in gray units (Gy). In RADIOLOGIC HEALTH, the dosage is expressed by the product of absorbed dose (Gy) and quality factor (a function of linear energy transfer), and is called radiation dose equivalent in sievert units (Sv).Radiation, Ionizing: ELECTROMAGNETIC RADIATION or particle radiation (high energy ELEMENTARY PARTICLES) capable of directly or indirectly producing IONS in its passage through matter. The wavelengths of ionizing electromagnetic radiation are equal to or smaller than those of short (far) ultraviolet radiation and include gamma and X-rays.Radiation Injuries: Harmful effects of non-experimental exposure to ionizing or non-ionizing radiation in VERTEBRATES.Dose-Response Relationship, Radiation: The relationship between the dose of administered radiation and the response of the organism or tissue to the radiation.Radiation Tolerance: The ability of some cells or tissues to survive lethal doses of IONIZING RADIATION. Tolerance depends on the species, cell type, and physical and chemical variables, including RADIATION-PROTECTIVE AGENTS and RADIATION-SENSITIZING AGENTS.Radiation: Emission or propagation of acoustic waves (SOUND), ELECTROMAGNETIC ENERGY waves (such as LIGHT; RADIO WAVES; GAMMA RAYS; or X-RAYS), or a stream of subatomic particles (such as ELECTRONS; NEUTRONS; PROTONS; or ALPHA PARTICLES).Radiation ProtectionRadiation Monitoring: The observation, either continuously or at intervals, of the levels of radiation in a given area, generally for the purpose of assuring that they have not exceeded prescribed amounts or, in case of radiation already present in the area, assuring that the levels have returned to those meeting acceptable safety standards.Radiation Oncology: A subspecialty of medical oncology and radiology concerned with the radiotherapy of cancer.Cosmic Radiation: High-energy radiation or particles from extraterrestrial space that strike the earth, its atmosphere, or spacecraft and may create secondary radiation as a result of collisions with the atmosphere or spacecraft.Radiation Injuries, Experimental: Experimentally produced harmful effects of ionizing or non-ionizing RADIATION in CHORDATA animals.Radiation Pneumonitis: Inflammation of the lung due to harmful effects of ionizing or non-ionizing radiation.Neoplasms, Radiation-Induced: Tumors, cancer or other neoplasms produced by exposure to ionizing or non-ionizing radiation.Gamma Rays: Penetrating, high-energy electromagnetic radiation emitted from atomic nuclei during NUCLEAR DECAY. The range of wavelengths of emitted radiation is between 0.1 - 100 pm which overlaps the shorter, more energetic hard X-RAYS wavelengths. The distinction between gamma rays and X-rays is based on their radiation source.Background Radiation: Radiation from sources other than the source of interest. It is due to cosmic rays and natural radioactivity in the environment.Radiotherapy: The use of IONIZING RADIATION to treat malignant NEOPLASMS and some benign conditions.Radiometry: The measurement of radiation by photography, as in x-ray film and film badge, by Geiger-Mueller tube, and by SCINTILLATION COUNTING.Radiotherapy Dosage: The total amount of radiation absorbed by tissues as a result of radiotherapy.Ultraviolet Rays: That portion of the electromagnetic spectrum immediately below the visible range and extending into the x-ray frequencies. The longer wavelengths (near-UV or biotic or vital rays) are necessary for the endogenous synthesis of vitamin D and are also called antirachitic rays; the shorter, ionizing wavelengths (far-UV or abiotic or extravital rays) are viricidal, bactericidal, mutagenic, and carcinogenic and are used as disinfectants.Radiation Effects: The effects of ionizing and nonionizing radiation upon living organisms, organs and tissues, and their constituents, and upon physiologic processes. It includes the effect of irradiation on food, drugs, and chemicals.Radiation-Sensitizing Agents: Drugs used to potentiate the effectiveness of radiation therapy in destroying unwanted cells.Combined Modality Therapy: The treatment of a disease or condition by several different means simultaneously or sequentially. Chemoimmunotherapy, RADIOIMMUNOTHERAPY, chemoradiotherapy, cryochemotherapy, and SALVAGE THERAPY are seen most frequently, but their combinations with each other and surgery are also used.Radiation-Protective Agents: Drugs used to protect against ionizing radiation. They are usually of interest for use in radiation therapy but have been considered for other, e.g. military, purposes.Acute Radiation Syndrome: A condition caused by a brief whole body exposure to more than one sievert dose equivalent of radiation. Acute radiation syndrome is initially characterized by ANOREXIA; NAUSEA; VOMITING; but can progress to hematological, gastrointestinal, neurological, pulmonary, and other major organ dysfunction.Radioactive Hazard Release: Uncontrolled release of radioactive material from its containment. This either threatens to, or does, cause exposure to a radioactive hazard. Such an incident may occur accidentally or deliberately.Cobalt Radioisotopes: Unstable isotopes of cobalt that decay or disintegrate emitting radiation. Co atoms with atomic weights of 54-64, except 59, are radioactive cobalt isotopes.Radiobiology: Study of the scientific principles, mechanisms, and effects of the interaction of ionizing radiation with living matter. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)Radiotherapy, Conformal: Radiotherapy where there is improved dose homogeneity within the tumor and reduced dosage to uninvolved structures. The precise shaping of dose distribution is achieved via the use of computer-controlled multileaf collimators.X-Rays: Penetrating electromagnetic radiation emitted when the inner orbital electrons of an atom are excited and release radiant energy. X-ray wavelengths range from 1 pm to 10 nm. Hard X-rays are the higher energy, shorter wavelength X-rays. Soft x-rays or Grenz rays are less energetic and longer in wavelength. The short wavelength end of the X-ray spectrum overlaps the GAMMA RAYS wavelength range. The distinction between gamma rays and X-rays is based on their radiation source.Radiation Hybrid Mapping: A method for ordering genetic loci along CHROMOSOMES. The method involves fusing irradiated donor cells with host cells from another species. Following cell fusion, fragments of DNA from the irradiated cells become integrated into the chromosomes of the host cells. Molecular probing of DNA obtained from the fused cells is used to determine if two or more genetic loci are located within the same fragment of donor cell DNA.Dose Fractionation: Administration of the total dose of radiation (RADIATION DOSAGE) in parts, at timed intervals.Radiotherapy, Intensity-Modulated: CONFORMAL RADIOTHERAPY that combines several intensity-modulated beams to provide improved dose homogeneity and highly conformal dose distributions.Brachytherapy: A collective term for interstitial, intracavity, and surface radiotherapy. It uses small sealed or partly-sealed sources that may be placed on or near the body surface or within a natural body cavity or implanted directly into the tissues.DNA Damage: Injuries to DNA that introduce deviations from its normal, intact structure and which may, if left unrepaired, result in a MUTATION or a block of DNA REPLICATION. These deviations may be caused by physical or chemical agents and occur by natural or unnatural, introduced circumstances. They include the introduction of illegitimate bases during replication or by deamination or other modification of bases; the loss of a base from the DNA backbone leaving an abasic site; single-strand breaks; double strand breaks; and intrastrand (PYRIMIDINE DIMERS) or interstrand crosslinking. Damage can often be repaired (DNA REPAIR). If the damage is extensive, it can induce APOPTOSIS.Linear Energy Transfer: Rate of energy dissipation along the path of charged particles. In radiobiology and health physics, exposure is measured in kiloelectron volts per micrometer of tissue (keV/micrometer T).Radiodermatitis: A cutaneous inflammatory reaction occurring as a result of exposure to ionizing radiation.Radiotherapy Planning, Computer-Assisted: Computer-assisted mathematical calculations of beam angles, intensities of radiation, and duration of irradiation in radiotherapy.Radiotherapy, Adjuvant: Radiotherapy given to augment some other form of treatment such as surgery or chemotherapy. Adjuvant radiotherapy is commonly used in the therapy of cancer and can be administered before or after the primary treatment.Radiation Genetics: A subdiscipline of genetics that studies RADIATION EFFECTS on the components and processes of biological inheritance.Leukemia, Radiation-Induced: Leukemia produced by exposure to IONIZING RADIATION or NON-IONIZING RADIATION.Nuclear Warfare: Warfare involving the use of NUCLEAR WEAPONS.Body Burden: The total amount of a chemical, metal or radioactive substance present at any time after absorption in the body of man or animal.Synchrotrons: Devices for accelerating protons or electrons in closed orbits where the accelerating voltage and magnetic field strength varies (the accelerating voltage is held constant for electrons) in order to keep the orbit radius constant.Radiation, Nonionizing: ELECTROMAGNETIC RADIATION or sonic radiation (SOUND WAVES) which does not produce IONS in matter through which it passes. The wavelengths of non-ionizing electromagentic radiation are generally longer than those of far ultraviolet radiation and range through the longest RADIO WAVES.Relative Biological Effectiveness: The ratio of radiation dosages required to produce identical change based on a formula comparing other types of radiation with that of gamma or roentgen rays.Electromagnetic Radiation: Waves of oscillating electric and MAGNETIC FIELDS which move at right angles to each other and outward from the source.Particle Accelerators: Devices which accelerate electrically charged atomic or subatomic particles, such as electrons, protons or ions, to high velocities so they have high kinetic energy.Cesium Radioisotopes: Unstable isotopes of cesium that decay or disintegrate emitting radiation. Cs atoms with atomic weights of 123, 125-132, and 134-145 are radioactive cesium isotopes.Fluoroscopy: Production of an image when x-rays strike a fluorescent screen.Abnormalities, Radiation-Induced: Congenital changes in the morphology of organs produced by exposure to ionizing or non-ionizing radiation.Whole-Body Irradiation: Irradiation of the whole body with ionizing or non-ionizing radiation. It is applicable to humans or animals but not to microorganisms.Sunlight: Irradiation directly from the sun.Thermoluminescent Dosimetry: The use of a device composed of thermoluminescent material for measuring exposure to IONIZING RADIATION. The thermoluminescent material emits light when heated. The amount of light emitted is proportional to the amount of ionizing radiation to which the material has been exposed.Beta Particles: High energy POSITRONS or ELECTRONS ejected from a disintegrating atomic nucleus.DNA Repair: The reconstruction of a continuous two-stranded DNA molecule without mismatch from a molecule which contained damaged regions. The major repair mechanisms are excision repair, in which defective regions in one strand are excised and resynthesized using the complementary base pairing information in the intact strand; photoreactivation repair, in which the lethal and mutagenic effects of ultraviolet light are eliminated; and post-replication repair, in which the primary lesions are not repaired, but the gaps in one daughter duplex are filled in by incorporation of portions of the other (undamaged) daughter duplex. Excision repair and post-replication repair are sometimes referred to as "dark repair" because they do not require light.Technology, Radiologic: The application of scientific knowledge or technology to the field of radiology. The applications center mostly around x-ray or radioisotopes for diagnostic and therapeutic purposes but the technological applications of any radiation or radiologic procedure is within the scope of radiologic technology.Nuclear Weapons: A weapon that derives its destructive force from nuclear fission and/or fusion.Radiography: Examination of any part of the body for diagnostic purposes by means of X-RAYS or GAMMA RAYS, recording the image on a sensitized surface (such as photographic film).Time Factors: Elements of limited time intervals, contributing to particular results or situations.Radiosurgery: A radiological stereotactic technique developed for cutting or destroying tissue by high doses of radiation in place of surgical incisions. It was originally developed for neurosurgery on structures in the brain and its use gradually spread to radiation surgery on extracranial structures as well. The usual rigid needles or probes of stereotactic surgery are replaced with beams of ionizing radiation directed toward a target so as to achieve local tissue destruction.Brain Neoplasms: Neoplasms of the intracranial components of the central nervous system, including the cerebral hemispheres, basal ganglia, hypothalamus, thalamus, brain stem, and cerebellum. Brain neoplasms are subdivided into primary (originating from brain tissue) and secondary (i.e., metastatic) forms. Primary neoplasms are subdivided into benign and malignant forms. In general, brain tumors may also be classified by age of onset, histologic type, or presenting location in the brain.Radioactive Fallout: The material that descends to the earth or water well beyond the site of a surface or subsurface nuclear explosion. (McGraw-Hill Dictionary of Chemical and Technical Terms, 4th ed)Solar Activity: Any type of variation in the appearance of energy output of the sun. (NASA Thesaurus, 1994)Tomography, X-Ray Computed: Tomography using x-ray transmission and a computer algorithm to reconstruct the image.Treatment Outcome: Evaluation undertaken to assess the results or consequences of management and procedures used in combating disease in order to determine the efficacy, effectiveness, safety, and practicability of these interventions in individual cases or series.Radiotherapy, High-Energy: Radiotherapy using high-energy (megavolt or higher) ionizing radiation. Types of radiation include gamma rays, produced by a radioisotope within a teletherapy unit; x-rays, electrons, protons, alpha particles (helium ions) and heavy charged ions, produced by particle acceleration; and neutrons and pi-mesons (pions), produced as secondary particles following bombardment of a target with a primary particle.Chernobyl Nuclear Accident: April 25th -26th, 1986 nuclear power accident that occurred at Chernobyl in the former USSR (Ukraine) located 80 miles north of Kiev.Cell Survival: The span of viability of a cell characterized by the capacity to perform certain functions such as metabolism, growth, reproduction, some form of responsiveness, and adaptability.Head and Neck Neoplasms: Soft tissue tumors or cancer arising from the mucosal surfaces of the LIP; oral cavity; PHARYNX; LARYNX; and cervical esophagus. Other sites included are the NOSE and PARANASAL SINUSES; SALIVARY GLANDS; THYROID GLAND and PARATHYROID GLANDS; and MELANOMA and non-melanoma skin cancers of the head and neck. (from Holland et al., Cancer Medicine, 4th ed, p1651)Neoplasms: New abnormal growth of tissue. Malignant neoplasms show a greater degree of anaplasia and have the properties of invasion and metastasis, compared to benign neoplasms.Cranial Irradiation: The exposure of the head to roentgen rays or other forms of radioactivity for therapeutic or preventive purposes.Heavy Ions: Positively-charged atomic nuclei that have been stripped of their electrons. These particles have one or more units of electric charge and a mass exceeding that of the Helium-4 nucleus (alpha particle).Infrared Rays: That portion of the electromagnetic spectrum usually sensed as heat. Infrared wavelengths are longer than those of visible light, extending into the microwave frequencies. They are used therapeutically as heat, and also to warm food in restaurants.Film Dosimetry: Use of a device (film badge) for measuring exposure of individuals to radiation. It is usually made of metal, plastic, or paper and loaded with one or more pieces of x-ray film.Radiography, Interventional: Diagnostic and therapeutic procedures that are invasive or surgical in nature, and require the expertise of a specially trained radiologist. In general, they are more invasive than diagnostic imaging but less invasive than major surgery. They often involve catheterization, fluoroscopy, or computed tomography. Some examples include percutaneous transhepatic cholangiography, percutaneous transthoracic biopsy, balloon angioplasty, and arterial embolization.Radiotherapy, Computer-Assisted: Computer systems or programs used in accurate computations for providing radiation dosage treatment to patients.Radioisotopes: Isotopes that exhibit radioactivity and undergo radioactive decay. (From Grant & Hackh's Chemical Dictionary, 5th ed & McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)Health Physics: The science concerned with problems of radiation protection relevant to reducing or preventing radiation exposure, and the effects of ionizing radiation on humans and their environment.Chemoradiotherapy: Treatment that combines chemotherapy with radiotherapy.Scattering, Radiation: The diversion of RADIATION (thermal, electromagnetic, or nuclear) from its original path as a result of interactions or collisions with atoms, molecules, or larger particles in the atmosphere or other media. (McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)Nuclear Reactors: Devices containing fissionable material in sufficient quantity and so arranged as to be capable of maintaining a controlled, self-sustaining NUCLEAR FISSION chain reaction. They are also known as atomic piles, atomic reactors, fission reactors, and nuclear piles, although such names are deprecated. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)Cobalt Isotopes: Stable cobalt atoms that have the same atomic number as the element cobalt, but differ in atomic weight. Co-59 is a stable cobalt isotope.Neoplasm Recurrence, Local: The local recurrence of a neoplasm following treatment. It arises from microscopic cells of the original neoplasm that have escaped therapeutic intervention and later become clinically visible at the original site.Phantoms, Imaging: Devices or objects in various imaging techniques used to visualize or enhance visualization by simulating conditions encountered in the procedure. Phantoms are used very often in procedures employing or measuring x-irradiation or radioactive material to evaluate performance. Phantoms often have properties similar to human tissue. Water demonstrates absorbing properties similar to normal tissue, hence water-filled phantoms are used to map radiation levels. Phantoms are used also as teaching aids to simulate real conditions with x-ray or ultrasonic machines. (From Iturralde, Dictionary and Handbook of Nuclear Medicine and Clinical Imaging, 1990)UkraineCarcinoma, Squamous Cell: A carcinoma derived from stratified SQUAMOUS EPITHELIAL CELLS. It may also occur in sites where glandular or columnar epithelium is normally present. (From Stedman, 25th ed)Retrospective Studies: Studies used to test etiologic hypotheses in which inferences about an exposure to putative causal factors are derived from data relating to characteristics of persons under study or to events or experiences in their past. The essential feature is that some of the persons under study have the disease or outcome of interest and their characteristics are compared with those of unaffected persons.Radioactive Pollutants: Radioactive substances which act as pollutants. They include chemicals whose radiation is released via radioactive waste, nuclear accidents, fallout from nuclear explosions, and the like.Cell Line, Tumor: A cell line derived from cultured tumor cells.Whole-Body Counting: Measurement of radioactivity in the entire human body.Radiotherapy, Image-Guided: The use of pre-treatment imaging modalities to position the patient, delineate the target, and align the beam of radiation to achieve optimal accuracy and reduce radiation damage to surrounding non-target tissues.Breast Neoplasms: Tumors or cancer of the human BREAST.Apoptosis: One of the mechanisms by which CELL DEATH occurs (compare with NECROSIS and AUTOPHAGOCYTOSIS). Apoptosis is the mechanism responsible for the physiological deletion of cells and appears to be intrinsically programmed. It is characterized by distinctive morphologic changes in the nucleus and cytoplasm, chromatin cleavage at regularly spaced sites, and the endonucleolytic cleavage of genomic DNA; (DNA FRAGMENTATION); at internucleosomal sites. This mode of cell death serves as a balance to mitosis in regulating the size of animal tissues and in mediating pathologic processes associated with tumor growth.Organs at Risk: Organs which might be damaged during exposure to a toxin or to some form of therapy. It most frequently refers to healthy organs located in the radiation field during radiation therapy.Neoplasm Staging: Methods which attempt to express in replicable terms the extent of the neoplasm in the patient.Alpha Particles: Positively charged particles composed of two protons and two NEUTRONS, i.e. equivalent to HELIUM nuclei, which are emitted during disintegration of heavy ISOTOPES. Alpha rays have very strong ionizing power, but weak penetrability.Nuclear Medicine: A specialty field of radiology concerned with diagnostic, therapeutic, and investigative use of radioactive compounds in a pharmaceutical form.Skin: The outer covering of the body that protects it from the environment. It is composed of the DERMIS and the EPIDERMIS.Occupational Exposure: The exposure to potentially harmful chemical, physical, or biological agents that occurs as a result of one's occupation.Radiation Chimera: An organism whose body contains cell populations of different genotypes as a result of the TRANSPLANTATION of donor cells after sufficient ionizing radiation to destroy the mature recipient's cells which would otherwise reject the donor cells.Phylogeny: The relationships of groups of organisms as reflected by their genetic makeup.Antineoplastic Agents: Substances that inhibit or prevent the proliferation of NEOPLASMS.Bystander Effect: The result of a positive or negative response (to drugs, for example) in one cell being passed onto other cells via the GAP JUNCTIONS or the intracellular milieu.Power Plants: Units that convert some other form of energy into electrical energy.Follow-Up Studies: Studies in which individuals or populations are followed to assess the outcome of exposures, procedures, or effects of a characteristic, e.g., occurrence of disease.Proctitis: INFLAMMATION of the MUCOUS MEMBRANE of the RECTUM, the distal end of the large intestine (INTESTINE, LARGE).Antineoplastic Combined Chemotherapy Protocols: The use of two or more chemicals simultaneously or sequentially in the drug therapy of neoplasms. The drugs need not be in the same dosage form.Yttrium Radioisotopes: Unstable isotopes of yttrium that decay or disintegrate emitting radiation. Y atoms with atomic weights 82-88 and 90-96 are radioactive yttrium isotopes.Radioimmunotherapy: Radiotherapy where cytotoxic radionuclides are linked to antibodies in order to deliver toxins directly to tumor targets. Therapy with targeted radiation rather than antibody-targeted toxins (IMMUNOTOXINS) has the advantage that adjacent tumor cells, which lack the appropriate antigenic determinants, can be destroyed by radiation cross-fire. Radioimmunotherapy is sometimes called targeted radiotherapy, but this latter term can also refer to radionuclides linked to non-immune molecules (see RADIOTHERAPY).Solar Energy: Energy transmitted from the sun in the form of electromagnetic radiation.Food Irradiation: Treatment of food with RADIATION.Amifostine: A phosphorothioate proposed as a radiation-protective agent. It causes splenic vasodilation and may block autonomic ganglia.Survival Analysis: A class of statistical procedures for estimating the survival function (function of time, starting with a population 100% well at a given time and providing the percentage of the population still well at later times). The survival analysis is then used for making inferences about the effects of treatments, prognostic factors, exposures, and other covariates on the function.Iridium Radioisotopes: Unstable isotopes of iridium that decay or disintegrate emitting radiation. Ir atoms with atomic weights 182-190, 192, and 194-198 are radioactive iridium isotopes.Survival Rate: The proportion of survivors in a group, e.g., of patients, studied and followed over a period, or the proportion of persons in a specified group alive at the beginning of a time interval who survive to the end of the interval. It is often studied using life table methods.Glioblastoma: A malignant form of astrocytoma histologically characterized by pleomorphism of cells, nuclear atypia, microhemorrhage, and necrosis. They may arise in any region of the central nervous system, with a predilection for the cerebral hemispheres, basal ganglia, and commissural pathways. Clinical presentation most frequently occurs in the fifth or sixth decade of life with focal neurologic signs or seizures.Adenocarcinoma: A malignant epithelial tumor with a glandular organization.Ataxia Telangiectasia Mutated Proteins: A group of PROTEIN-SERINE-THREONINE KINASES which activate critical signaling cascades in double strand breaks, APOPTOSIS, and GENOTOXIC STRESS such as ionizing ultraviolet A light, thereby acting as a DNA damage sensor. These proteins play a role in a wide range of signaling mechanisms in cell cycle control.Genetic Speciation: The splitting of an ancestral species into daughter species that coexist in time (King, Dictionary of Genetics, 6th ed). Causal factors may include geographic isolation, HABITAT geometry, migration, REPRODUCTIVE ISOLATION, random GENETIC DRIFT and MUTATION.Glioma: Benign and malignant central nervous system neoplasms derived from glial cells (i.e., astrocytes, oligodendrocytes, and ependymocytes). Astrocytes may give rise to astrocytomas (ASTROCYTOMA) or glioblastoma multiforme (see GLIOBLASTOMA). Oligodendrocytes give rise to oligodendrogliomas (OLIGODENDROGLIOMA) and ependymocytes may undergo transformation to become EPENDYMOMA; CHOROID PLEXUS NEOPLASMS; or colloid cysts of the third ventricle. (From Escourolle et al., Manual of Basic Neuropathology, 2nd ed, p21)Tumor Suppressor Protein p53: Nuclear phosphoprotein encoded by the p53 gene (GENES, P53) whose normal function is to control CELL PROLIFERATION and APOPTOSIS. A mutant or absent p53 protein has been found in LEUKEMIA; OSTEOSARCOMA; LUNG CANCER; and COLORECTAL CANCER.Cisplatin: An inorganic and water-soluble platinum complex. After undergoing hydrolysis, it reacts with DNA to produce both intra and interstrand crosslinks. These crosslinks appear to impair replication and transcription of DNA. The cytotoxicity of cisplatin correlates with cellular arrest in the G2 phase of the cell cycle.Microwaves: That portion of the electromagnetic spectrum from the UHF (ultrahigh frequency) radio waves and extending into the INFRARED RAYS frequencies.Radiopharmaceuticals: Compounds that are used in medicine as sources of radiation for radiotherapy and for diagnostic purposes. They have numerous uses in research and industry. (Martindale, The Extra Pharmacopoeia, 30th ed, p1161)Radiation Leukemia Virus: A strain of Murine leukemia virus (LEUKEMIA VIRUS, MURINE) isolated from radiation-induced lymphomas in C57BL mice. It is leukemogenic, thymotrophic, can be transmitted vertically, and replicates only in vivo.Iodine Radioisotopes: Unstable isotopes of iodine that decay or disintegrate emitting radiation. I atoms with atomic weights 117-139, except I 127, are radioactive iodine isotopes.Space Flight: Travel beyond the earth's atmosphere.Neutrons: Electrically neutral elementary particles found in all atomic nuclei except light hydrogen; the mass is equal to that of the proton and electron combined and they are unstable when isolated from the nucleus, undergoing beta decay. Slow, thermal, epithermal, and fast neutrons refer to the energy levels with which the neutrons are ejected from heavier nuclei during their decay.Disease-Free Survival: Period after successful treatment in which there is no appearance of the symptoms or effects of the disease.Chemotherapy, Adjuvant: Drug therapy given to augment or stimulate some other form of treatment such as surgery or radiation therapy. Adjuvant chemotherapy is commonly used in the therapy of cancer and can be administered before or after the primary treatment.Sunscreening Agents: Chemical or physical agents that protect the skin from sunburn and erythema by absorbing or blocking ultraviolet radiation.Deinococcus: A genus of gram-positive aerobic cocci found in the soil, that is highly resistant to radiation, especially ionizing radiation (RADIATION, IONIZING). Deinococcus radiodurans is the type species.Cell Cycle: The complex series of phenomena, occurring between the end of one CELL DIVISION and the end of the next, by which cellular material is duplicated and then divided between two daughter cells. The cell cycle includes INTERPHASE, which includes G0 PHASE; G1 PHASE; S PHASE; and G2 PHASE, and CELL DIVISION PHASE.Pelvic Neoplasms: Tumors or cancer of the pelvic region.Lymphatic Irradiation: External or interstitial irradiation to treat lymphomas (e.g., Hodgkin's and non-Hodgkin's lymphomas) and lymph node metastases and also some autoimmune diseases, such as rheumatoid arthritis.Mice, Nude: Mutant mice homozygous for the recessive gene "nude" which fail to develop a thymus. They are useful in tumor studies and studies on immune responses.Nuclear Power Plants: Facilities that convert NUCLEAR ENERGY into electrical energy.Skin Neoplasms: Tumors or cancer of the SKIN.Mastectomy, Segmental: Removal of only enough breast tissue to ensure that the margins of the resected surgical specimen are free of tumor.Neoplasms, Second Primary: Abnormal growths of tissue that follow a previous neoplasm but are not metastases of the latter. The second neoplasm may have the same or different histological type and can occur in the same or different organs as the previous neoplasm but in all cases arises from an independent oncogenic event. The development of the second neoplasm may or may not be related to the treatment for the previous neoplasm since genetic risk or predisposing factors may actually be the cause.DNA Breaks, Double-Stranded: Interruptions in the sugar-phosphate backbone of DNA, across both strands adjacently.Tumor Cells, Cultured: Cells grown in vitro from neoplastic tissue. If they can be established as a TUMOR CELL LINE, they can be propagated in cell culture indefinitely.Photons: Discrete concentrations of energy, apparently massless elementary particles, that move at the speed of light. They are the unit or quantum of electromagnetic radiation. Photons are emitted when electrons move from one energy state to another. (From Hawley's Condensed Chemical Dictionary, 11th ed)Erythema: Redness of the skin produced by congestion of the capillaries. This condition may result from a variety of causes.Astronauts: Members of spacecraft crew including those who travel in space, and those in training for space flight. (From Webster, 10th ed; Jane's Aerospace Dictionary, 3d ed)Prognosis: A prediction of the probable outcome of a disease based on a individual's condition and the usual course of the disease as seen in similar situations.Positron-Emission Tomography: An imaging technique using compounds labelled with short-lived positron-emitting radionuclides (such as carbon-11, nitrogen-13, oxygen-15 and fluorine-18) to measure cell metabolism. It has been useful in study of soft tissues such as CANCER; CARDIOVASCULAR SYSTEM; and brain. SINGLE-PHOTON EMISSION-COMPUTED TOMOGRAPHY is closely related to positron emission tomography, but uses isotopes with longer half-lives and resolution is lower.Biological Evolution: The process of cumulative change over successive generations through which organisms acquire their distinguishing morphological and physiological characteristics.Radiology, Interventional: Subspecialty of radiology that combines organ system radiography, catheter techniques and sectional imaging.Tumor Burden: The total amount (cell number, weight, size or volume) of tumor cells or tissue in the body.Hodgkin Disease: A malignant disease characterized by progressive enlargement of the lymph nodes, spleen, and general lymphoid tissue. In the classical variant, giant usually multinucleate Hodgkin's and REED-STERNBERG CELLS are present; in the nodular lymphocyte predominant variant, lymphocytic and histiocytic cells are seen.Rhenium: Rhenium. A metal, atomic number 75, atomic weight 186.2, symbol Re. (Dorland, 28th ed)Risk Assessment: The qualitative or quantitative estimation of the likelihood of adverse effects that may result from exposure to specified health hazards or from the absence of beneficial influences. (Last, Dictionary of Epidemiology, 1988)Mice, Inbred C3HElasticity Imaging Techniques: Non-invasive imaging methods based on the mechanical response of an object to a vibrational or impulsive force. It is used for determining the viscoelastic properties of tissue, and thereby differentiating soft from hard inclusions in tissue such as microcalcifications, and some cancer lesions. Most techniques use ultrasound to create the images - eliciting the response with an ultrasonic radiation force and/or recording displacements of the tissue by Doppler ultrasonography.Fossils: Remains, impressions, or traces of animals or plants of past geological times which have been preserved in the earth's crust.Reproducibility of Results: The statistical reproducibility of measurements (often in a clinical context), including the testing of instrumentation or techniques to obtain reproducible results. The concept includes reproducibility of physiological measurements, which may be used to develop rules to assess probability or prognosis, or response to a stimulus; reproducibility of occurrence of a condition; and reproducibility of experimental results.Environmental Exposure: The exposure to potentially harmful chemical, physical, or biological agents in the environment or to environmental factors that may include ionizing radiation, pathogenic organisms, or toxic chemicals.Radiographic Image Enhancement: Improvement in the quality of an x-ray image by use of an intensifying screen, tube, or filter and by optimum exposure techniques. Digital processing methods are often employed.Thoracic NeoplasmsActuarial Analysis: The application of probability and statistical methods to calculate the risk of occurrence of any event, such as onset of illness, recurrent disease, hospitalization, disability, or death. It may include calculation of the anticipated money costs of such events and of the premiums necessary to provide for payment of such costs.Equipment Design: Methods of creating machines and devices.Ataxia Telangiectasia: An autosomal recessive inherited disorder characterized by choreoathetosis beginning in childhood, progressive CEREBELLAR ATAXIA; TELANGIECTASIS of CONJUNCTIVA and SKIN; DYSARTHRIA; B- and T-cell immunodeficiency, and RADIOSENSITIVITY to IONIZING RADIATION. Affected individuals are prone to recurrent sinobronchopulmonary infections, lymphoreticular neoplasms, and other malignancies. Serum ALPHA-FETOPROTEINS are usually elevated. (Menkes, Textbook of Child Neurology, 5th ed, p688) The gene for this disorder (ATM) encodes a cell cycle checkpoint protein kinase and has been mapped to chromosome 11 (11q22-q23).Nuclear Energy: Energy released by nuclear fission or nuclear fusion.DNA-Activated Protein Kinase: A serine-threonine protein kinase that, when activated by DNA, phosphorylates several DNA-binding protein substrates including the TUMOR SUPPRESSOR PROTEIN P53 and a variety of TRANSCRIPTION FACTORS.Rectal Neoplasms: Tumors or cancer of the RECTUM.Models, Biological: Theoretical representations that simulate the behavior or activity of biological processes or diseases. For disease models in living animals, DISEASE MODELS, ANIMAL is available. Biological models include the use of mathematical equations, computers, and other electronic equipment.DNA-Binding Proteins: Proteins which bind to DNA. The family includes proteins which bind to both double- and single-stranded DNA and also includes specific DNA binding proteins in serum which can be used as markers for malignant diseases.Four-Dimensional Computed Tomography: Three-dimensional computed tomographic imaging with the added dimension of time, to follow motion during imaging.Radiographic Image Interpretation, Computer-Assisted: Computer systems or networks designed to provide radiographic interpretive information.Fibroblasts: Connective tissue cells which secrete an extracellular matrix rich in collagen and other macromolecules.DNA: A deoxyribonucleotide polymer that is the primary genetic material of all cells. Eukaryotic and prokaryotic organisms normally contain DNA in a double-stranded state, yet several important biological processes transiently involve single-stranded regions. DNA, which consists of a polysugar-phosphate backbone possessing projections of purines (adenine and guanine) and pyrimidines (thymine and cytosine), forms a double helix that is held together by hydrogen bonds between these purines and pyrimidines (adenine to thymine and guanine to cytosine).Cone-Beam Computed Tomography: Computed tomography modalities which use a cone or pyramid-shaped beam of radiation.Nasopharyngeal Neoplasms: Tumors or cancer of the NASOPHARYNX.Dacarbazine: An antineoplastic agent. It has significant activity against melanomas. (from Martindale, The Extra Pharmacopoeia, 31st ed, p564)Mutation: Any detectable and heritable change in the genetic material that causes a change in the GENOTYPE and which is transmitted to daughter cells and to succeeding generations.Osteoradionecrosis: Necrosis of bone following radiation injury.Cell Line: Established cell cultures that have the potential to propagate indefinitely.Misonidazole: A nitroimidazole that sensitizes normally radio-resistant hypoxic cells to radiation. It may also be directly cytotoxic to hypoxic cells and has been proposed as an antineoplastic.Fluorouracil: A pyrimidine analog that is an antineoplastic antimetabolite. It interferes with DNA synthesis by blocking the THYMIDYLATE SYNTHETASE conversion of deoxyuridylic acid to thymidylic acid.Xenograft Model Antitumor Assays: In vivo methods of screening investigative anticancer drugs, biologic response modifiers or radiotherapies. Human tumor tissue or cells are transplanted into mice or rats followed by tumor treatment regimens. A variety of outcomes are monitored to assess antitumor effectiveness.Feasibility Studies: Studies to determine the advantages or disadvantages, practicability, or capability of accomplishing a projected plan, study, or project.Molecular Sequence Data: Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories.Risk Factors: An aspect of personal behavior or lifestyle, environmental exposure, or inborn or inherited characteristic, which, on the basis of epidemiologic evidence, is known to be associated with a health-related condition considered important to prevent.Samarium: Samarium. An element of the rare earth family of metals. It has the atomic symbol Sm, atomic number 62, and atomic weight 150.36. The oxide is used in the control rods of some nuclear reactors.Strontium Radioisotopes: Unstable isotopes of strontium that decay or disintegrate spontaneously emitting radiation. Sr 80-83, 85, and 89-95 are radioactive strontium isotopes.Protein-Serine-Threonine Kinases: A group of enzymes that catalyzes the phosphorylation of serine or threonine residues in proteins, with ATP or other nucleotides as phosphate donors.Radon: A naturally radioactive element with atomic symbol Rn, atomic number 86, and atomic weight 222. It is a member of the noble gas family found in soil, and is released during the decay of radium.Skin Pigmentation: Coloration of the skin.Carcinoma, Non-Small-Cell Lung: A heterogeneous aggregate of at least three distinct histological types of lung cancer, including SQUAMOUS CELL CARCINOMA; ADENOCARCINOMA; and LARGE CELL CARCINOMA. They are dealt with collectively because of their shared treatment strategy.Magnetic Resonance Imaging: Non-invasive method of demonstrating internal anatomy based on the principle that atomic nuclei in a strong magnetic field absorb pulses of radiofrequency energy and emit them as radiowaves which can be reconstructed into computerized images. The concept includes proton spin tomographic techniques.Hyperthermia, Induced: Abnormally high temperature intentionally induced in living things regionally or whole body. It is most often induced by radiation (heat waves, infra-red), ultrasound, or drugs.Air Pollution, RadioactiveCell Cycle Proteins: Proteins that control the CELL DIVISION CYCLE. This family of proteins includes a wide variety of classes, including CYCLIN-DEPENDENT KINASES, mitogen-activated kinases, CYCLINS, and PHOSPHOPROTEIN PHOSPHATASES as well as their putative substrates such as chromatin-associated proteins, CYTOSKELETAL PROTEINS, and TRANSCRIPTION FACTORS.Mice, Inbred C57BLPlutonium: Plutonium. A naturally radioactive element of the actinide metals series. It has the atomic symbol Pu, atomic number 94, and atomic weight 242. Plutonium is used as a nuclear fuel, to produce radioisotopes for research, in radionuclide batteries for pacemakers, and as the agent of fission in nuclear weapons.Fast Neutrons: Neutrons, the energy of which exceeds some arbitrary level, usually around one million electron volts.Radioisotope Teletherapy: A type of high-energy radiotherapy using a beam of gamma-radiation produced by a radioisotope source encapsulated within a teletherapy unit.Tissue Distribution: Accumulation of a drug or chemical substance in various organs (including those not relevant to its pharmacologic or therapeutic action). This distribution depends on the blood flow or perfusion rate of the organ, the ability of the drug to penetrate organ membranes, tissue specificity, protein binding. The distribution is usually expressed as tissue to plasma ratios.Soil Pollutants, Radioactive: Pollutants, present in soil, which exhibit radioactivity.Sarcoma: A connective tissue neoplasm formed by proliferation of mesodermal cells; it is usually highly malignant.

Radiation target analysis indicates that phenylalanine hydroxylase in rat liver extracts is a functional monomer. (1/181)

The minimal enzymatically functional form of purified rat hepatic phenylalanine hydroxylase (PAH) is a dimer of identical subunits. Radiation target analysis of PAH revealed that the minimal enzymatically active form in crude extracts corresponds to the monomer. The 'negative regulation' properties of the tetrahydrobiopterin cofactor in both crude and pure samples implicates a large multimeric structure, minimally a tetramer of PAH subunits. Preincubation of the samples with phenylalanine prior to irradiation abolished this inhibition component without affecting the minimal functional unit target sizes of the enzyme in both preparations. The characteristics of rat hepatic PAH determined by studies of the purified enzyme in vitro may not completely represent the properties of PAH in vivo.  (+info)

Case study of the effects of atmospheric aerosols and regional haze on agriculture: an opportunity to enhance crop yields in China through emission controls? (2/181)

The effect of atmospheric aerosols and regional haze from air pollution on the yields of rice and winter wheat grown in China is assessed. The assessment is based on estimates of aerosol optical depths over China, the effect of these optical depths on the solar irradiance reaching the earth's surface, and the response of rice and winter wheat grown in Nanjing to the change in solar irradiance. Two sets of aerosol optical depths are presented: one based on a coupled, regional climate/air quality model simulation and the other inferred from solar radiation measurements made over a 12-year period at meteorological stations in China. The model-estimated optical depths are significantly smaller than those derived from observations, perhaps because of errors in one or both sets of optical depths or because the data from the meteorological stations has been affected by local pollution. Radiative transfer calculations using the smaller, model-estimated aerosol optical depths indicate that the so-called "direct effect" of regional haze results in an approximately 5-30% reduction in the solar irradiance reaching some of China's most productive agricultural regions. Crop-response model simulations suggest an approximately 1:1 relationship between a percentage increase (decrease) in total surface solar irradiance and a percentage increase (decrease) in the yields of rice and wheat. Collectively, these calculations suggest that regional haze in China is currently depressing optimal yields of approximately 70% of the crops grown in China by at least 5-30%. Reducing the severity of regional haze in China through air pollution control could potentially result in a significant increase in crop yields and help the nation meet its growing food demands in the coming decades.  (+info)

Rejoining of radiation-induced single-strand breaks in deoxyribonucleic acid of Escherichia coli: effect of phenethyl alcohol. (3/181)

Single-strand breaks in deoxyribonucleic acid of Escherichia coli B/r cells exposed to 20 krads of gamma radiation could be rejoined by incubation of irradiated cells in growth medium. In the presence of 0.25% phenethyl alcohol, this repair was completely inhibited although deoxyribonucleic acid and protein syntheses were suppressed only partially.  (+info)

Promotion of secondary anti-DNP antibody production in mice by type III pneumococcal polysaccharide (SIII) and dinitrophenylated rabbit antibody to SIII. (4/181)

Type III pneumococcal polysaccharide (SIII) is able markedly to increase the adoptive IgG ANTI-DNP antibody response of B cells primed to DNP-flagellin and stimulated with DNP conjugated to the heterologous carrier, rabbit globulin, provided the latter has anti-SIII activity. The stimulatory effect is apparently accessory cell-dependent as well as being unequivocally T cell-dependent. Although no positive evidence is available, the possibility exists that non-specific T-cell activation is involved in the stimulating effect of anti-SIII plus SIII.  (+info)

Male infertility risk factors in a French military population. (5/181)

We investigated infertility risk factors by conducting a population-based case-control study in the military population of the French town of Brest. Sixty couples who had sought medical advice for infertility of more than 12 months duration (cases) were compared with 165 couples who had had a child (controls). All the men in these couples had been employed by the military. The infertility risk factors studied were male and female medical factors, occupational and environmental exposures. We obtained age-adjusted odds ratios of 7.4 [95% confidence interval (CI): 1.4--39.5] for testis surgery, and 13.0 for varicocele (95% CI: 1.4--120.3) in men. In logistic regression, the age-adjusted odds ratio for men who had worked in a nuclear submarine was found to be 2.0 (95% CI: 1.0--3.7), and that for heat exposure was 4.5 (95% CI: 1.9--10.6). One limitation of this study is the lack of exposure measurements, especially for potential exposure to nuclear radiation (type of reactor used in nuclear-powered submarines, inability to obtain personal dosimeters worn by military personnel working in nuclear submarines). In conclusion, this study suggests that in this military population, having worked as a submariner in a nuclear-powered submarine, and having worked in very hot conditions, should be considered as risk factors for infertility.  (+info)

Calcium protects differentiating neuroblastoma cells during 50 Hz electromagnetic radiation. (6/181)

Despite growing concern about electromagnetic radiation, the interaction between 50- to 60-Hz fields and biological structures remains obscure. Epidemiological studies have failed to prove a significantly correlation between exposure to radiation fields and particular pathologies. We demonstrate that a 50- to 60-Hz magnetic field interacts with cell differentiation through two opposing mechanisms: it antagonizes the shift in cell membrane surface charges that occur during the early phases of differentiation and it modulates hyperpolarizing K channels by increasing intracellular Ca. The simultaneous onset of both mechanisms prevents alterations in cell differentiation. We propose that cells are normally protected against electromagnetic insult. Pathologies may arise, however, if intracellular Ca regulation or K channel activation malfunctions.  (+info)


ersonal view:  (+info)

The farnesyl transferase inhibitor RPR-130401 does not alter radiation susceptibility in human tumor cells with a K-Ras mutation in spite of large changes in ploidy and lamin B distribution. (8/181)

BACKGROUND: Growth inhibition by RPR-130401, a non-peptidomimetic farnesyltransferase inhibitor, was investigated without or with combined exposure to ionizing radiation in three human tumor cell lines (HCT-116, MiAPaCa-2 and A-549) bearing a point mutation in the K-Ras gene. RESULTS: RPR-130401 inhibited cell growth with an IC50 of 50 nM (HCT-116), 120 nM (MiAPaCa-2) and 710 nM (A-549), with a poor incidence of apoptosis. The drug brought about G1 and S phase depletion together with arrest of cells in G2 phase and induced a significant accumulation of hyperploid cells showing active S phase DNA synthesis, with HCT-116 and A-549 cells being the most and least responsive, respectively. The drug also produced dramatic changes of the nuclear lamin B pattern, without lamin B cleavage and perturbation of the actin cytoskeleton. On the other hand, RPR-130401 elicited strictly additive interaction in combined treatment with ionizing radiation with regard to cell kill, altered cell cycle progression and induced hyperploidy. CONCLUSIONS: The data suggest that disruption of orderly progression through mitosis and cytokinesis, is a major outcome of drug action and that this effect proceeds from inhibition of lamin B farnesylation. It is anticipated from the strict additivity of RPR-130401 and radiation that neither induced radiation resistance nor acute or late complications of radiotherapy, should occur in combined treatment with RPR-130401.  (+info)

  • His professional research area is biological and health effects of electromagnetic fields and ionizing radiation, DNA damage and repair, chromosomal aberrations, apoptosis, molecular markers for radio sensitivity. (healthandenvironment.org)
  • The findings, which chronicle an unprecedented number of rodents subjected to a lifetime of electromagnetic radiation starting in utero, present some of the strongest evidence to date that such exposure is associated with the formation of rare cancers in at least two cell types in the brains and hearts of rats. (wordpress.com)
  • Süleyman Kaplan, MD , professor at Ondokuz Mayis University, Samsun, Turkey, Department of Histology and Embryology, is a pioneer is the analysis of embryology and the author of a major paper published in the journal Brain Research showing that prenatal exposures to cellphone radiation in rats results in offspring with smaller brains with more brain damage and greater structural damage to their skulls. (healthandenvironment.org)
  • The tumors in the male rats "are considered likely the result of whole-body exposure" to this radiation, the study authors wrote. (wordpress.com)
  • Federal scientists released partial findings Friday from a $25-million animal study that tested the possibility of links between cancer and chronic exposure to the type of radiation emitted from cell phones and wireless devices. (wordpress.com)
  • The International Agency for Research on Cancer in 2011 classified RF radiation as a possible human carcinogen. (wordpress.com)
  • Based on these findings, Portier said that this is not just an associated finding-but that the relationship between radiation exposure and cancer is clear. (wordpress.com)
  • Earlier studies had never found that this type of radiation was associated with the formation of these cancers in animals at all. (wordpress.com)
  • He suspected that it was radiation from the cell phone that caused the hair loss. (hairlossly.com)
  • Acute Radiation Syndrome (ARS) , or radiation sickness, is a serious illness that can happen when a person is exposed to very high levels of radiation, usually over a short period of time. (cdc.gov)
  • Barabanova AV (2002) Acute radiation syndrome with cutaneous syndrome. (springer.com)
  • Fliedner TM, Friescke I, Beyrer K (2001) Medical management of radiation accidents: manual on the acute radiation syndrome. (springer.com)
  • This is known as acute radiation syndrome, commonly known as "radiation sickness. (epa.gov)
  • Acute radiation syndrome is rare, and comes from extreme events like a nuclear explosion or accidental handling or rupture of a highly radioactive source. (epa.gov)
  • Radiation sickness (or acute radiation syndrome) usually sets in after a whole-body dose of three sieverts-3,000 times the recommended public dose limit per year, Langhorst says. (scientificamerican.com)
  • The main concerns are that a significant number of non-destructive testing contractors fail to adopt routine working practices capable of keeping radiation exposures of employees as low as reasonably practicable: this is the main requirement of the Ionising Radiations Regulations 2017 (IRR17). (hse.gov.uk)
  • He has been Secretary of the Advisory Group on Ionising Radiation from 2005, a member of the International Commission on Radiological Protection (ICRP) Committee (2013 - 2017) and a Main Commission member (2017 - present). (le.ac.uk)
  • Even though this type of radiation does travel throughout the body, the radioactive substance mostly collects in the area of the tumor, so there's still little effect on the rest of the body. (cancer.org)
  • Doctors measure these effects in terms of "rems" or " sieverts ," which are related to the type of radiation and the amount of energy that gets absorbed by a given mass of tissue. (slate.com)
  • Ionizing radiation is a type of radiation which is sufficiently energetic to push an electron out of the outer shell of an atom. (utwente.nl)
  • Understanding the type of radiation received, the way a person is exposed (external vs. internal), and for how long a person is exposed are all important in estimating health effects. (epa.gov)
  • This type of radiation has sufficient energy to ionize atoms (usually creating a positive charge by knocking out electrons), thereby giving them the chemical potential to react deleteriously with the atoms and molecules of living tissues. (scientificamerican.com)
  • This is the most common type of radiation used to treat multiple myeloma . (webmd.com)
  • During this type of radiation, the high-energy beams come from a machine outside of your body that aims the beams at a precise point on your body. (drugs.com)
  • The walls of a building can block much of the harmful radiation. (cdc.gov)
  • According to Gofman and O'Connor (in their book X-Rays: Health Effects of Common Exams), "It is natural for everyone, ourselves included, to wish that radiation would be less harmful per rad at low dose-ranges than at high dose-ranges. (google.com)
  • The books by Gofman13 and Gofman and O'Connor14 are replete with reports which prove that low doses of radiation are in many cases more harmful than higher doses. (google.com)
  • In a denselypopulated city, thousands of people could be exposed to harmful levels of radiation from an explosion from a dirty bomb. (faqs.org)
  • The University of Bath is committed to providing and maintaining a safe and healthy work place and to protect its employees, students, contractors and visitors from potential harmful levels of ionising radiation. (bath.ac.uk)
  • Also there are specific plants that absorb harmful radiations to create a viable and healthy environment. (slideshare.net)
  • Less familiar are gamma rays , which come from nuclear reactions and radioactive decay and are part of the harmful high-energy radiation of radioactive materials and nuclear weapons . (britannica.com)
  • Non-ionizing radiation is a collective term for several types of radiation which are not harmful in low dosages and without long-term exposure. (utwente.nl)
  • But thankfully, the overwhelming majority of Japanese people appears to have been spared from any harmful levels of radiation. (forbes.com)
  • 5,000-10,000 millirem or 50-100 millisieverts) usually result in no harmful health effects, because radiation below these levels is a minor contributor to our overall cancer risk. (epa.gov)
  • Radiation protection is to prevent the occurrence of harmful deterministic effects and to reduce the probability of occurrence of stochastic effects (e.g. cancer and hereditary effects). (ilo.org)
  • The objective of this publication is to establish requirements for the protection of people and the environment from harmful effects of ionizing radiation and for the safety of radiation sources. (ilo.org)
  • Despite the doom and gloom associated with the term in popular parlance, however, what radiation safety experts are referring to when we say "contamination" is rarely harmful. (popularmechanics.com)
  • Lesser amounts of atmospheric oxygen meant that the planet lacked its protective ozone layer, which blocks out much harmful radiation from the sun. (space.com)
  • The radiation beams are shaped by tiny metal leaves that are arranged to fit the tumor dimensions (multi-leaf collimator), minimizing the side effects to healthy tissue. (mdanderson.org)
  • IMRT focuses multiple radiation beams of different intensities directly on the tumor for the highest possible dose. (mdanderson.org)
  • To spare normal tissues (such as skin or organs which radiation must pass through to treat the tumor), shaped radiation beams are aimed from several angles of exposure to intersect at the tumor, providing a much larger absorbed dose there than in the surrounding, healthy tissue. (wikipedia.org)
  • She is expert in Radiation Chemistry and her studies concern the mechanisms induced in various inorganic, organic and biological systems by high-energy radiations, such as electron beams (from the LINAC accelerator) or gamma-rays (from 60 Co). Her research activity is also focused on the analysis and modeling of complex kinetics by using conventional or numerically integrated computer tools. (springer.com)
  • Radiation beams are aimed at your whole body to help slow down your immune system . (webmd.com)
  • External beam radiation uses high-powered beams of energy to kill cancer cells. (drugs.com)
  • Beams of radiation are precisely aimed at the cancer using a machine that moves around your body. (drugs.com)
  • The precise dose and focus of radiation beams used in your treatment is carefully planned to maximize the radiation to your cancer cells and minimize the harm to surrounding healthy tissue. (drugs.com)
  • With highly precise image-guided treatment delivery, we can target the radiation on the tumor and avoid healthy tissue more successfully than before. (uchicagomedicine.org)
  • This technique ensures the maximum radiation dose is given to cancerous tissues, while minimizing exposure to the surrounding healthy tissue. (uchicagomedicine.org)
  • Ionizing radiation works by damaging the DNA of cancerous tissue leading to cellular death . (wikipedia.org)
  • Normal cells are more likely to recover from its effects, though, and the health care team will take extensive measures to carefully monitor a child's radiation doses to protect healthy tissue. (kidshealth.org)
  • The new brain-scan-based work, to be published Feb. 23 in the Journal of the American Medical Association , shows radiation emitted from a cellphone's antenna during a call makes nearby brain tissue use 7 percent more energy. (wired.com)
  • Measured in watts per kilogram of tissue, it reveals how much radiation parts of the body are exposed to during use of a mobile device. (wired.com)
  • The health care team will carefully check a teen's radiation doses to protect healthy tissue. (kidshealth.org)
  • When living tissue is exposed to this over too long a period of time, the heat development due to the absorption of the radiation can cause damage to the tissue. (utwente.nl)
  • Ionizing radiation can affect the atoms in living things, so it poses a health risk by damaging tissue and DNA in genes. (epa.gov)
  • Grays are a way of measuring radiation that looks purely at the energy deposited in tissue, known as the absorbed dose. (sciencemag.org)
  • Radiation applicators comprise an elongate device having an antenna (240, 340) at their tip for coupling radiation into biological tissue and a dielectric body (250, 350) surrounding the antenna so as to encompass substantially the whole of the near-field region of the antenna and/or to enhance transmission. (google.ca)
  • He also has interests in the effects of UV light, electromagnetic fields, chemical agents and mechanisms of normal tissue effects following radiation exposure. (le.ac.uk)
  • NRC officials said it was worrisome that those VA safety organizations failed to identify problems such as underdosing of patients, accidentally implanting radioactive seeds in patient's bladders, and delivering excessive radiation doses to patients' rectums and other healthy tissue. (philly.com)
  • Radiation destroys the surrounding healthy tissue causing the prostate to be embedded in scar tissue. (livescience.com)
  • This makes the surgery more complex than operating on tissue that has not been affected by radiation. (livescience.com)
  • Radiation is a good option in certain cases, and there are clear benefits to radiating the tissue to prevent disease recurrence, even after surgery. (uc.edu)
  • Centers for Disease Control and Prevention (2005) Cutaneous radiation injury: fact sheet for physicians. (springer.com)
  • Visit the U.S. Centers for Disease Control and Prevention (CDC) for more information about possible health effects of radiation exposure and contamination. (epa.gov)
  • Oak Ridge Institute for Science and Education, ORISE-EHSD-REAC/TS (2000) Radiation accidents registries. (springer.com)
  • By comparison, most of us receive about 300 mrem annually from natural radiation, and a single whole-body CT scan will give us about 2000 mrem. (popularmechanics.com)
  • Examples of ionizing radiation include x rays, gamma rays, beta particle radiation, and alpha particle radiation (also known as alpha rays). (faqs.org)
  • Unlike other forms of radiation, like gamma rays or X-rays , alpha emissions can be blocked by something as insubstantial as a piece of paper or the layer of dead cells on the surface of the skin. (slate.com)
  • X rays, gamma rays ( γ ), beta particle radiation ([.beta]), and alpha particle ([.alpha]) radiation (also known as alpha rays) are ionizing form of radiation. (encyclopedia.com)
  • Radiation retinopathy: electron microscopy of retina and optic nerve. (springer.com)
  • For example, hydrogen requires a photon with an energy of 13.6 eV (one electron volt = 1.602 10-19 joule) to be ionized, meaning radiation with a frequency of about 3.28 1015Hz, which corresponds with the frequency of ultraviolet light. (utwente.nl)
  • This includes a free information sheet 'Industrial radiography - managing radiation risks' Ionising Radiation Protection sheet IRP1 and an inspection and advice programme. (hse.gov.uk)
  • The nuclear disaster at Fukushima Daiichi in Japan was perhaps the worst of all time, but despite that ominous reputation, radiation risks to the surrounding population are surprisingly slight. (forbes.com)
  • In terms of public health, the radiation exposure from Fukushima Daiichi poses negligible risks to those in the studied areas. (forbes.com)
  • For patients undergoing medical radiation there is no strict exposure limit-it is the responsibility of medical professionals to weigh the risks and benefits of radiation used in diagnostics and treatment, according to Langhorst. (scientificamerican.com)
  • Dr. Michael Lauer of the National Heart, Lung, and Blood Institute, one of the National Institutes of Health, said imaging equipment makers are working on new products to reduce radiation risks. (ibtimes.com)
  • Radiation oncologists use special planning software to make sure the patient is properly positioned for the most accurate treatment. (mdanderson.org)
  • Smilow's radiation oncologists - who are also on the faculty at Yale School of Medicine - work closely to collaborate with a comprehensive team of medical oncologists, surgeons, nurses, radiation therapists, medical physicists and dosimetrists. (ynhh.org)
  • In a radiation emergency, such as a nuclear power plant accident, a nuclear detonation or the explosion of a dirty bomb you may be asked to get inside a building and take shelter for a period of time instead of leaving. (cdc.gov)
  • As fears swelled over radiation from Japan's battered Fukushima Daiichi nuclear power plant in the days after the 11 March quake, computer-savvy individuals around the globe had an immediate reaction: show people the data. (sciencemag.org)
  • The developing crisis at the Fukushima Daiichi nuclear power plant in the wake of the March 11 earthquake and tsunami has raised concerns over the health effects of radiation exposure: What is a 'dangerous' level of radiation? (scientificamerican.com)
  • IAEA (1996) IAEA safety series: international basic safety standards for protection against ionizing radiation and for the safety of radiation sources. (springer.com)
  • Source monitoring is a specific term used in ionising radiation monitoring, and according to the IAEA, is the measurement of activity in radioactive material being released to the environment or of external dose rates due to sources within a facility or activity. (wikipedia.org)
  • The methodological and technical details of the design and operation of source and environmental radiation monitoring programmes and systems for different radionuclides, environmental media and types of facility are given in IAEA Safety Standards Series No. RS-G-1.8 and in IAEA Safety Reports Series No. 64. (wikipedia.org)
  • IAEA Safety Glossary: Terminology Used in Nuclear Safety and Radiation Protection (PDF). (wikipedia.org)
  • At various times the subject has fallen under the headings "radiation psychology" and "radiopsychology" or, most often, under various forms of the heading "effects of radiation upon behavior. (encyclopedia.com)
  • From the beginning, biomedical scientists found that behavioral effects of radiation provided substantive data to aid in the understanding of the structure and function of organ systems. (encyclopedia.com)
  • The problems of studying the effects of radiation are numerous and complex (see Bibliography). (encyclopedia.com)
  • Mettler FA, Moseley RD (1985) Carcinogenesis of specific sites and direct effects of radiation. (springer.com)
  • David Sumner, a consultant physicist and specialist on the health effects of radiation, argues that the risk to the individual is not the important point. (newscientist.com)
  • As worries grow over radiation leaks at Fukushima, is it possible to gauge the immediate and lasting health effects of radiation exposure? (scientificamerican.com)
  • Depending on the dose, the effects of radiation can be mild or life-threatening. (medicalnewstoday.com)
  • People are exposed to small amounts of radiation every day from sources such as sunlight. (medlineplus.gov)
  • including many people, such as Emil Grubbe who were exposed to significant amounts of radiation and lived long and fruitful lives. (huffingtonpost.com)
  • Alpha and beta particle radiation is lower energy and can often be blocked by just a sheet of paper. (scientificamerican.com)
  • GB Parliament (1999) Ionising radiation regulations, 1999, SI 1999. (springer.com)
  • GB Parliament (2001) The radiation (emergency preparedness and public information) regulations. (springer.com)
  • All use of radioactive materials and radiation-producing machines is governed by the provisions of Title 17 (California Code of Regulations Title 17) , 10 CFR 20 (Code of Federal Regulations, Title 10, Chapter 1 part 20) and any additional provisions given in the Radiation Safety Manual. (csusm.edu)
  • Wednesday, top radiation safety officials from the Department of Veteran's Affairs will testify before a panel of the U.S. Nuclear Regulatory Commission in advance of the agency's decision on how to address three apparent violations of federal radiation safety regulations. (philly.com)
  • Our goal is to keep radiation exposure to University personnel, members of the public, and the environment As Low As Reasonably Achievable (ALARA) and in compliance with state and federal regulations. (etsu.edu)
  • If you are outside during a radiation emergency and cannot get inside immediately, covering your mouth and nose with a mask, cloth, or towel can help reduce the amount of radioactive material you breathe. (cdc.gov)
  • If I was outside when a radiation emergency happened, what should I do to remove radioactive material from myself? (cdc.gov)
  • This increased risk of radiation damage is of concern, as terrorist organizations such as al Qaeda have made efforts to develop and deploy 'dirty bombs'-conventional explosives that release a payload of radioactive material. (faqs.org)
  • Ionizing radiation is any one of several types of particles and rays given off by radioactive material, high-voltage equipment, nuclear reactions, and stars. (cdc.gov)
  • It can also come from an implant (a small container of radioactive material) placed (either temporarily or permanently) directly into or near the tumor (internal or interstitial radiation). (medicinenet.com)
  • Radioactive material (sealed or unsealed sources) and radiation producing devices (such as X-ray units) are important tools in research and educational activities. (csusm.edu)
  • This is a basic course and does not take the place of annual radiation safety training for those working in laboratories that handle radioactive material. (k-state.edu)
  • If radioactive material is ingested or inhaled into the body, however, it is actually the lower energy alpha and beta radiation that becomes the more dangerous. (scientificamerican.com)
  • The two biggest contributors to radiation exposure were an advanced kind of X-ray called a computed tomography or CT scan and nuclear medicine scans -- in which a small amount of radioactive material is injected into the bloodstream and read by special cameras. (ibtimes.com)
  • Learn about the nature of the radiations emitted by radioactive material and X-ray generating equipment. (warwick.ac.uk)
  • While students would find it useful to know something about the radioactive material they work with, no prior knowledge of radiation safety is needed. (warwick.ac.uk)
  • Radiation physicists from universities, other federal laboratories, and companies in the Washington, DC area are participating in early work at the MIRF to construct and characterize a beam-line for use in accelerator physics studies. (nist.gov)
  • The therapist will aim a beam of radiation right where your bone's been damaged or where a tumor is. (webmd.com)
  • Image guidance is available on all of our radiation machines and includes X-rays, standard strength CT imaging built into radiation machines, and fully functional CT imaging scanners built into a treatment suite alongside the radiation machine. (mdanderson.org)
  • What are the different types of UV radiation rays? (cdc.gov)
  • In everyday life, radiation in the form of X-rays is used to create images of areas of the body that doctors can't see, such as the inside of a tooth or the interior of the chest cavity. (kidshealth.org)
  • These radiation particles and rays carry enough energy to knock out electrons from atoms and molecules (such as water, protein, and DNA) that they hit or pass near. (cdc.gov)
  • When ionizing radiation from outer space hits the upper atmosphere, it produces a shower of cosmic rays that constantly expose everything on earth. (cdc.gov)
  • Some ionizing radiation is made on demand, such as when doctors take x rays. (cdc.gov)
  • Radiation in the implant can send high-energy rays outside the patient's body. (kidshealth.org)
  • This level of radiation would be like getting the radiation from 18,000 chest x-rays distributed over your entire body in this short period. (epa.gov)
  • Ionizing radiation includes cosmic rays, X rays and the radiation from radioactive materials. (ilo.org)
  • UV radiation has shorter wavelengths (higher frequencies) compared to visible light but have longer wavelengths (lower frequencies) compared to X-rays. (ccohs.ca)
  • For select patients for whom further surgery at the tumor site is not possible, delivering targeted radiation reduces the risk of local recurrence while minimizing dose to non-cancerous organs. (uchicagomedicine.org)
  • Interestingly, increased radiation dose delivery using daily dose adaptation was correlated with less grade 3 toxicity (0% in the high dose group vs 15.8% in patients treated to lower radiation doses without dose adaptation). (clinicaltrials.gov)
  • Risk of radiation retinopathy in patients with orbital and ocular lymphoma. (springer.com)
  • According to current international guidelines, it is assumed that even the smallest radiation dose poses a risk to patients. (news-medical.net)
  • Because the level of radiation is highest during the hospital stay, patients may not be able to have visitors or may have visitors only for a short time. (medicinenet.com)
  • We don't want to scare people and have them refuse necessary procedures, but physicians and patients need to be aware that radiation is not benign," study researcher Reza Fazel, MD, of Atlanta's Emory University School of Medicine, tells WebMD. (webmd.com)
  • In NSW during the first four years in practice, after which standard pay peaks, radiation therapists (who treat patients with high-energy radiation) earn $35,954-$50,458, nuclear medicine scientists (who test body functions) earn $35,560-$47,000 and the hourly rate for radiographers (who perform diagnostic procedures) rises from $20 to $26 an hour. (smh.com.au)
  • Because one of the basic premises of homeopathic medicine is that small doses of a treatment can help to heal those symptoms that large doses are known to cause, Ludlam suggested to Grubbe that radiation may be a treatment for conditions such as tumors because it also causes them. (huffingtonpost.com)
  • Learn about brain tumors and treatment options including radiation, chemotherapy and surgery. (merlot.org)
  • Reactors at the Fukushima Daiichi plant, 240 km (150 miles) north of Tokyo, have leaked radiation after they were struck on March 11 by a massive earthquake and tsunami that led to the world's worst nuclear crisis in a quarter of a century. (reuters.com)
  • Provides a frame of reference for relative hazards of radiation. (cdc.gov)
  • Understand the hazards of radiation and what is done on campus to make sure we work with radiation as safely as possible. (k-state.edu)
  • In other words, exposure to a low level of radiation can be damaging over time. (faqs.org)
  • The spray of radiation in a mid-level dirty bomb could produce a relatively low level of radiation over a fairly localized area. (faqs.org)
  • A very high level of radiation exposure delivered over a short period of time can cause symptoms such as nausea and vomiting within hours and can sometimes result in death over the following days or weeks. (epa.gov)
  • The level of radiation decreases dramatically as distance from the site increases. (scientificamerican.com)
  • In many countries handset manufacturers must disclose the maximum level of radiation emitted and similar legislation is starting to appear in the United States, Friedlander said. (ibtimes.com)
  • Photons having the same energy h ν are all alike, and their number density corresponds to the intensity of the radiation. (britannica.com)
  • In quantum mechanics , radiation pressure can be interpreted as the transfer of momentum from photons as they strike a surface. (daviddarling.info)
  • The fundamental photon and charged particle interaction data and the radiation transport methods, pioneered and developed at NIST to calculate the penetration. (nist.gov)