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.
Unstable isotopes of cobalt that decay or disintegrate emitting radiation. Co atoms with atomic weights of 54-64, except 59, are radioactive cobalt isotopes.
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).
Treatment of food with RADIATION.
The relationship between the dose of administered radiation and the response of the organism or tissue to the radiation.
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.
Determination of the energy distribution of gamma rays emitted by nuclei. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)
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.
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).
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.
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).
Californium. A man-made radioactive actinide with atomic symbol Cf, atomic number 98, and atomic weight 251. Its valence can be +2 or +3. Californium has medical use as a radiation source for radiotherapy.
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.
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.
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.
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).
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.
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.
Radiation from sources other than the source of interest. It is due to cosmic rays and natural radioactivity in the environment.
The measurement of radiation by photography, as in x-ray film and film badge, by Geiger-Mueller tube, and by SCINTILLATION COUNTING.
Tumors, cancer or other neoplasms produced by exposure to ionizing or non-ionizing radiation.
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.
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.
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.
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)
A species of anaerobic, gram-positive, rod-shaped bacteria in the family Clostridiaceae that produces proteins with characteristic neurotoxicity. It is the etiologic agent of BOTULISM in humans, wild fowl, HORSES; and CATTLE. Seven subtypes (sometimes called antigenic types, or strains) exist, each producing a different botulinum toxin (BOTULINUM TOXINS). The organism and its spores are widely distributed in nature.
The production of an image obtained by cameras that detect the radioactive emissions of an injected radionuclide as it has distributed differentially throughout tissues in the body. The image obtained from a moving detector is called a scan, while the image obtained from a stationary camera device is called a scintiphotograph.
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.
Irradiation of the whole body with ionizing or non-ionizing radiation. It is applicable to humans or animals but not to microorganisms.
A subclass of cartilaginous fish comprising the SHARKS; rays; skates (SKATES (FISH);), and sawfish. Elasmobranchs are typically predaceous, relying more on smell (the olfactory capsules are relatively large) than sight (the eyes are relatively small) for obtaining their food.
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.
The common name for all members of the Rajidae family. Skates and rays are members of the same order (Rajiformes). Skates have weak electric organs.
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.
Abnormal number or structure of chromosomes. Chromosome aberrations may result in CHROMOSOME DISORDERS.
Harmful effects of non-experimental exposure to ionizing or non-ionizing radiation in VERTEBRATES.
Inbred C3H mice are a strain of laboratory mice that have been selectively bred to maintain a high degree of genetic uniformity and share specific genetic characteristics, including susceptibility to certain diseases, which makes them valuable for biomedical research purposes.
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.
Elements of limited time intervals, contributing to particular results or situations.
Membranous appendage of fish and other aquatic organisms used for locomotion or balance.
White blood cells formed in the body's lymphoid tissue. The nucleus is round or ovoid with coarse, irregularly clumped chromatin while the cytoplasm is typically pale blue with azurophilic (if any) granules. Most lymphocytes can be classified as either T or B (with subpopulations of each), or NATURAL KILLER CELLS.
A vacuum tube equipped with an electron emitting CATHODE and a fluorescent screen which emits visible light when excited by the cathode ray. Cathode ray tubes are used as imaging devises for TELEVISIONS; COMPUTER TERMINALS; TEXT TELECOMMUNICATION DEVICES; oscilloscopes; and other DATA DISPLAY devices.
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.
The major interferon produced by mitogenically or antigenically stimulated LYMPHOCYTES. It is structurally different from TYPE I INTERFERON and its major activity is immunoregulation. It has been implicated in the expression of CLASS II HISTOCOMPATIBILITY ANTIGENS in cells that do not normally produce them, leading to AUTOIMMUNE DISEASES.

Characterization of nuclear structures containing superhelical DNA. (1/2775)

Structures resembling nuclei but depleted of protein may be released by gently lysing cells in solutions containing non-ionic detergents and high concentrations of salt. These nucleoids sediment in gradients containing intercalating agents in a manner characteristic of DNA that is intact, supercoiled and circular. The concentration of salt present during isolation of human nucleoids affects their protein content. When made in I-95 M NaCl they lack histones and most of the proteins characteristic of chromatin; in 1-0 M NaCl they contain variable amounts of histones. The effects of various treatments on nucleoid integrity were investigated.  (+info)

Nuclear foci of mammalian recombination proteins are located at single-stranded DNA regions formed after DNA damage. (2/2775)

A sensitive and rapid in situ method was developed to visualize sites of single-stranded (ss) DNA in cultured cells and in experimental test animals. Anti-bromodeoxyuridine antibody recognizes the halogenated base analog incorporated into chromosomal DNA only when substituted DNA is in the single strand form. After treatment of cells with DNA-damaging agents or gamma irradiation, ssDNA molecules form nuclear foci in a dose-dependent manner within 60 min. The mammalian recombination protein Rad51 and the replication protein A then accumulate at sites of ssDNA and form foci, suggesting that these are sites of recombinational DNA repair.  (+info)

Exposure to indoor background radiation and urinary concentrations of 8-hydroxydeoxyguanosine, a marker of oxidative DNA damage. (3/2775)

We investigated whether exposure to indoor [gamma]-radiation and radon might be associated with enough free radical formation to increase urinary concentrations of 8-hydroxydeoxyguanosine (8-OHdG), a sensitive marker of DNA damage, due to a hydroxyl radical attack at the C8 of guanine. Indoor radon and [gamma]-radiation levels were measured in 32 dwellings for 6 months by solid-state nuclear track detectors and thermoluminescent dosimeters, respectively. Urine samples for 8-OHdG determinations were obtained from 63 healthy adult subjects living in the measured dwellings. An overall tendency toward increasing levels of 8-OHdG with increasing levels of radon and [gamma]-radiation was seen in the females, presumably due to their estimated longer occupancy in the dwellings measured. Different models were considered for females, with the steepest slopes obtained for [gamma]-radiation with a coefficient of 0.500 (log nmol/l of 8-OHdG for each unit increase of [gamma]-radiation on a log scale) (p<0.01), and increasing to 0.632 (p = 0.035), but with larger variance, when radon was included in the model. In conclusion, there seems to be an effect of indoor radioactivity on the urinary excretion of 8-OHdG for females, who are estimated to have a higher occupancy in the dwellings measured than for males, for whom occupational and other agents may also influence 8-OHdG excretion. ree radicals; [gamma]-radiation; radon.  (+info)

Bcl-2 inhibits ischemia-reperfusion-induced apoptosis in the intestinal epithelium of transgenic mice. (4/2775)

Little is known about the effects of ischemia-reperfusion on the inductive, commitment, or execution phases of apoptosis. We have created a genetically defined model to study the response of small intestinal epithelial cells to ischemia-reperfusion injury as a function of their proliferative status and differentiation. Occlusion of the superior mesenteric artery for 20 min in adult FVB/N or C57BL/6 mice results in the appearance of TUNEL-positive apoptotic cells in the jejunal epithelium within 4 h, with a maximum response occurring at 24 h. Stimulation of apoptosis is greater in postmitotic, differentiated epithelial cells located in the upper portions of villi compared with undifferentiated, proliferating cells in the crypts of Lieberkuhn (7-fold vs. 2-fold relative to sham-operated controls). Comparisons of p53(+/+) and p53(-/-) mice established that the apoptosis is p53 independent. To further characterize this response, we generated FVB/N transgenic mice that express human Bcl-2 in epithelial cells distributed from the base of crypts to the tips of their associated villi. The fivefold elevation in steady-state Bcl-2 concentration is not accompanied by detectable changes in the levels or cellular distributions of the related anti-apoptotic regulator Bcl-xL or of the proapoptotic regulators Bax and Bak and does not produce detectable effects on basal proliferation, differentiation, or death programs. The apoptotic response to ischemia-reperfusion is reduced twofold in the crypts and villi of transgenic mice compared with their normal littermates. These results suggest that both undifferentiated and differentiated cells undergo a commitment phase that is sensitive to Bcl-2. Forced expression of Bcl-2 also suppressed the p53-dependent death that occurs in proliferating crypt epithelial cells following gamma-irradiation. Thus suppressibility by Bcl-2 operationally defines a common feature of the apoptosis induced in the crypt epithelium by these two stimuli.  (+info)

Cyclin D1 overexpression enhances radiation-induced apoptosis and radiosensitivity in a breast tumor cell line. (5/2775)

Overexpression of cyclin D1, a G1 cell cycle regulator, is often found in many different tumor types, such as breast carcinoma and squamous cell carcinoma of the head and neck. The overexpression of this protein is, in several cases, associated with a poor prognosis. In this study, the effect of cyclin D1 on radiosensitivity was investigated in a breast tumor cell line, MCF7, containing a cyclin D1 gene construct under the control of a tetracycline-sensitive regulator. MCF7 cells cultured without tetracycline resulted in a 6-fold increase in the cyclin D1 protein. Cyclin D1-overexpressing MCF7 cells were more sensitive to ionizing radiation than the nonoverexpressing counterparts. The cyclin D1-overexpressing cells also exhibited a higher induction of apoptosis. Treatment with a dose of 5 Gy resulted in a rapid increase of p53 and p21 in the cyclin D1-overexpressing cells. Nonoverexpressing cells showed a more transient expression of these proteins after ionizing radiation. A pronounced G2-M block was observed in both cell lines. The cyclin D1-overexpressing cells were, however, released earlier from the block than the control cells. These data suggest that overexpression of cyclin D1 alters sensitivity toward ionizing radiation by modulating gamma-radiation-induced G2-M transition.  (+info)

Functional interaction between retinoblastoma protein and stress-activated protein kinase in multiple myeloma cells. (6/2775)

Previous studies have demonstrated that gamma-irradiation (IR)-induced apoptosis in multiple myeloma (MM) is associated with activation of stress-activated protein kinase (SAPK). In the present study, we examined the molecules downstream of SAPK/C-Jun N-terminal kinase (JNK), focusing on the role of retinoblastoma protein (Rb) during IR-induced MM cell apoptosis. The results demonstrate that IR activates SAPK/JNK, which associates with Rb both in vivo and in vitro. Far Western blot analysis confirms that SAPK/JNK binds directly to Rb. IR-activated SAPK/JNK phosphorylates Rb, and deletion of the phosphorylation site in the COOH terminus domain of Rb abrogates phosphorylation of Rb by SAPK/JNK. Taken together, our results suggest that Rb is a target protein of SAPK/JNK and that the association of SAPK/JNK and Rb mediates IR-induced apoptosis in MM cells.  (+info)

Regulation of p53 expression by thymidylate synthase. (7/2775)

Previous studies showed that thymidylate synthase (TS), as an RNA binding protein, regulates its own synthesis by impairing the translation of TS mRNA. In this report, we present evidence that p53 expression is affected in a similar manner by TS. For these studies, we used a TS-depleted human colon cancer HCT-C cell that had been transfected with either the human TS cDNA or the Escherichia coli TS gene. The level of p53 protein in transfected cells overexpressing human TS was significantly reduced when compared with its corresponding parent HCT-C cells. This suppression of p53 expression was the direct result of decreased translational efficiency of p53 mRNA. Similar results were obtained upon transfection of HCT-C cells with pcDNA 3.1 (+) containing the E. coli TS gene. These findings provide evidence that TS, from diverse species, specifically regulates p53 expression at the translational level. In addition, TS-overexpressing cells with suppressed levels of p53 are significantly impaired in their ability to arrest in G1 phase in response to exposure to a DNA-damaging agent such as gamma-irradiation. These studies provide support for the in vivo biological relevance of the interaction between TS and p53 mRNA and identify a molecular pathway for controlling p53 expression.  (+info)

Phosphorylation of p53 protein in response to ionizing radiation occurs at multiple sites in both normal and DNA-PK deficient cells. (8/2775)

The tumour suppressor gene product, p53, is involved in mediating cellular responses to DNA damage including growth arrest and/or apoptosis. The mechanism by which p53 protein senses the presence of damaged DNA is not understood. The possibility that p53 may be post-translationally modified by enzymes that are activated in response to DNA damage including DNA-dependent protein kinase (DNA-PK), poly(ADP-ribose) polymerase and stress activated protein kinase has received considerable attention. Recent studies have indicated that DNA-PK is not required for the transactivation or apoptosis-promoting activities of p53 protein. However, the possibility that other functions of p53 may be dependent on phosphorylation by DNA-PK has not been explored. Here we describe a series of experiments that compares the expression, function and phosphorylation status of p53 protein in normal and DNA-PK-deficient scid cells. While several novel p53 phosphoforms are generated in response to DNA damage in normal cells, the same phosphoforms are observed in scid cells.  (+info)

Gamma rays are a type of ionizing radiation that is released from the nucleus of an atom during radioactive decay. They are high-energy photons, with wavelengths shorter than 0.01 nanometers and frequencies greater than 3 x 10^19 Hz. Gamma rays are electromagnetic radiation, similar to X-rays, but with higher energy levels and the ability to penetrate matter more deeply. They can cause damage to living tissue and are used in medical imaging and cancer treatment.

Cobalt radioisotopes are radioactive forms of the element cobalt, which are used in various medical applications. The most commonly used cobalt radioisotope is Cobalt-60 (Co-60), which has a half-life of 5.27 years.

Co-60 emits gamma rays and beta particles, making it useful for radiation therapy to treat cancer, as well as for sterilizing medical equipment and food irradiation. In radiation therapy, Co-60 is used in teletherapy machines to deliver a focused beam of radiation to tumors, helping to destroy cancer cells while minimizing damage to surrounding healthy tissue.

It's important to note that handling and disposal of cobalt radioisotopes require strict safety measures due to their radioactive nature, as they can pose risks to human health and the environment if not managed properly.

Linear Energy Transfer (LET) is a concept in radiation physics that describes the amount of energy that is transferred from an ionizing particle to a medium per unit length along its path. It is usually expressed in units of keV/μm (kiloelectron volts per micrometer). High-LET radiations, such as alpha particles and heavy ions, transfer more energy to the medium per unit length than low-LET radiations, such as X-rays and gamma rays. This results in a higher probability of producing dense ionizations and causing biological damage along the particle's path. Therefore, LET is an important factor in determining the relative biological effectiveness (RBE) of different types of radiation.

Food irradiation is a process that uses ionizing radiation to kill bacteria, parasites, and insects in food. It also slows down the ripening and sprouting of foods and eliminates or reduces the need for chemical fumigants and preservatives. The food does not become radioactive as a result of irradiation.

The three types of radiation sources used for food irradiation are gamma rays, electron beams, and X-rays. Gamma rays are produced naturally by the decay of radioisotopes such as cobalt-60 or cesium-137. Electron beams and X-rays are produced artificially.

Food irradiation is regulated in many countries, including the United States, where it is approved for use on a variety of foods, including spices, herbs, seasonings, fruits, vegetables, grains, poultry, red meats, and eggs. The process is considered safe for human consumption and has been endorsed by numerous scientific organizations, including the World Health Organization (WHO), the Food and Agriculture Organization of the United Nations (FAO), and the U.S. Food and Drug Administration (FDA).

A dose-response relationship in radiation refers to the correlation between the amount of radiation exposure (dose) and the biological response or adverse health effects observed in exposed individuals. As the level of radiation dose increases, the severity and frequency of the adverse health effects also tend to increase. This relationship is crucial in understanding the risks associated with various levels of radiation exposure and helps inform radiation protection standards and guidelines.

The effects of ionizing radiation can be categorized into two types: deterministic and stochastic. Deterministic effects have a threshold dose below which no effect is observed, and above this threshold, the severity of the effect increases with higher doses. Examples include radiation-induced cataracts or radiation dermatitis. Stochastic effects, on the other hand, do not have a clear threshold and are based on probability; as the dose increases, so does the likelihood of the adverse health effect occurring, such as an increased risk of cancer.

Understanding the dose-response relationship in radiation exposure is essential for setting limits on occupational and public exposure to ionizing radiation, optimizing radiation protection practices, and developing effective medical countermeasures in case of radiation emergencies.

Cobalt isotopes are variants of the chemical element Cobalt (Co) that have different numbers of neutrons in their atomic nuclei. This results in the different isotopes having slightly different masses and varying levels of stability.

The most naturally occurring stable cobalt isotope is Co-59, which contains 27 neutrons in its nucleus. However, there are also several radioactive isotopes of cobalt, including Co-60, which is a commonly used medical and industrial radioisotope.

Co-60 has 30 neutrons in its nucleus and undergoes beta decay, emitting gamma rays and becoming Nickel-60. It has a half-life of approximately 5.27 years, making it useful for a variety of applications, including cancer treatment, industrial radiography, and sterilization of medical equipment.

Other radioactive isotopes of cobalt include Co-57, which has a half-life of 271.8 days and is used in medical imaging, and Co-56, which has a half-life of just 77.2 seconds and is used in research.

Gamma spectrometry is a type of spectrometry used to identify and measure the energy and intensity of gamma rays emitted by radioactive materials. It utilizes a device called a gamma spectrometer, which typically consists of a scintillation detector or semiconductor detector, coupled with electronic circuitry that records and analyzes the energy of each detected gamma ray.

Gamma rays are a form of ionizing radiation, characterized by their high energy and short wavelength. When they interact with matter, such as the detector in a gamma spectrometer, they can cause the ejection of electrons from atoms or molecules, leading to the creation of charged particles that can be detected and measured.

In gamma spectrometry, the energy of each detected gamma ray is used to identify the radioactive isotope that emitted it, based on the characteristic energy levels associated with different isotopes. The intensity of the gamma rays can also be measured, providing information about the quantity or activity of the radioactive material present.

Gamma spectrometry has a wide range of applications in fields such as nuclear medicine, radiation protection, environmental monitoring, and nuclear non-proliferation.

Relative Biological Effectiveness (RBE) is a term used in radiation biology and medicine to describe the relative effectiveness of different types or energies of ionizing radiation in causing biological damage, compared to a reference radiation such as high-energy photons (X-rays or gamma rays). RBE takes into account the differences in biological impact between various types of radiation, which can be due to differences in linear energy transfer (LET), quality factor, and other factors. It is used to estimate the biological effects of mixed radiation fields, such as those encountered in radiotherapy treatments that combine different types or energies of radiation. The RBE value for a specific type of radiation is determined through experimental studies that compare its biological impact to that of the reference radiation.

Radiation dosage, in the context of medical physics, refers to the amount of radiation energy that is absorbed by a material or tissue, usually measured in units of Gray (Gy), where 1 Gy equals an absorption of 1 Joule of radiation energy per kilogram of matter. In the clinical setting, radiation dosage is used to plan and assess the amount of radiation delivered to a patient during treatments such as radiotherapy. It's important to note that the biological impact of radiation also depends on other factors, including the type and energy level of the radiation, as well as the sensitivity of the irradiated tissues or organs.

Cesium radioisotopes are different forms of the element cesium that have unstable nuclei and emit radiation. Some commonly used medical cesium radioisotopes include Cs-134 and Cs-137, which are produced from nuclear reactions in nuclear reactors or during nuclear weapons testing.

In medicine, cesium radioisotopes have been used in cancer treatment for the brachytherapy of certain types of tumors. Brachytherapy involves placing a small amount of radioactive material directly into or near the tumor to deliver a high dose of radiation to the cancer cells while minimizing exposure to healthy tissues.

Cesium-137, for example, has been used in the treatment of cervical, endometrial, and prostate cancers. However, due to concerns about potential long-term risks associated with the use of cesium radioisotopes, their use in cancer therapy is becoming less common.

It's important to note that handling and using radioactive materials requires specialized training and equipment to ensure safety and prevent radiation exposure.

Heavy ions, in the context of medicine, typically refer to charged particles that are used in the field of radiation therapy for cancer treatment. These particles are much heavier than electrons and carry a positive charge, unlike the negatively charged electrons or neutral photons used in conventional radiotherapy.

The term "heavy ions" is often associated with carbon ions or other ions like oxygen or neon. The high mass and charge of these particles result in unique physical properties that allow for more targeted and precise cancer treatment compared to traditional radiation therapy methods.

When heavy ions pass through tissue, they deposit most of their energy at the end of their range, creating a narrow, highly-damaging track known as the Bragg peak. This property enables clinicians to concentrate the dose of radiation within the tumor while minimizing exposure to surrounding healthy tissues. The result is a potentially more effective and less toxic treatment option for certain types of cancer, particularly those that are radioresistant or located near critical organs.

It's important to note that heavy ion therapy requires specialized equipment, such as particle accelerators and gantry systems, which limits its availability to a smaller number of medical facilities worldwide.

Californium is a synthetic actinide radioactive metallic element with the symbol Cf and atomic number 98. It was first synthesized in 1950 by Stanley G. Thompson, Kenneth Street, Jr., Albert Ghiorso, and Glenn T. Seaborg at the University of California, Berkeley. Californium is produced artificially in nuclear reactors and does not occur naturally.

Californium has several isotopes, with the most stable being californium-251, which has a half-life of 898 years. It is used in various applications, including as a power source for artificial heart pacemakers, as a neutron source for industrial radiography, and in cancer treatment.

It's important to note that due to its radioactive nature, californium must be handled with great care and precaution, and its use is regulated by governmental agencies such as the Nuclear Regulatory Commission in the United States.

I'm sorry for any confusion, but neutrons are not a medical term. They are a fundamental particle in physics and chemistry. Neutrons are neutral particles found in the nucleus of an atom, alongside protons. Together, they make up the atomic nucleus, while electrons orbit around it.

Neutrons are not typically discussed in the context of medical definitions unless it's in relation to nuclear medicine, radiation therapy or other specialized medical fields that involve ionizing radiation and nuclear reactions. If you have any questions related to medical terminology, I would be happy to help!

Thermoluminescent dosimetry (TLD) is a passive dosimetry technique used to measure ionizing radiation exposure. It utilizes the property of certain materials, known as thermoluminescent materials or TLDs, to emit light when they are heated after being exposed to radiation.

The process involves exposing a TLD material, such as lithium fluoride (LiF) or calcium sulfate (CaSO4), to ionizing radiation. The radiation causes electrons in the material to become trapped in metastable energy levels. When the TLD material is subsequently heated, these trapped electrons are released and return to their ground state, emitting light in the process. The intensity of this thermoluminescent glow is proportional to the amount of radiation exposure the material has received.

TLDs offer several advantages over other dosimetry techniques. They can be used to measure both acute and chronic radiation exposures, are relatively insensitive to environmental factors such as temperature and humidity, and can be read out multiple times for comparison or calibration purposes. Additionally, TLD materials can be made into small, lightweight badges that can be worn by individuals to monitor their personal radiation exposure.

Overall, thermoluminescent dosimetry is a valuable tool in radiation protection, providing an accurate and reliable means of measuring ionizing radiation exposure for medical, industrial, and research applications.

Radiation effects refer to the damages that occur in living tissues when exposed to ionizing radiation. These effects can be categorized into two types: deterministic and stochastic. Deterministic effects have a threshold dose below which the effect does not occur, and above which the severity of the effect increases with the dose. Examples include radiation-induced erythema, epilation, and organ damage. Stochastic effects, on the other hand, do not have a threshold dose, and the probability of the effect occurring increases with the dose. Examples include genetic mutations and cancer induction. The severity of the effect is not related to the dose in this case.

Medical Definition:

Radiation is the emission of energy as electromagnetic waves or as moving subatomic particles, especially high-energy particles that cause ionization, which can occur naturally (e.g., sunlight) or be produced artificially (e.g., x-rays, radioisotopes). In medicine, radiation is used diagnostically and therapeutically in various forms, such as X-rays, gamma rays, and radiopharmaceuticals, to diagnose and treat diseases like cancer. However, excessive exposure to radiation can pose health risks, including radiation sickness and increased risk of cancer.

Radiation tolerance, in the context of medicine and particularly radiation oncology, refers to the ability of tissues or organs to withstand and recover from exposure to ionizing radiation without experiencing significant damage or loss of function. It is often used to describe the maximum dose of radiation that can be safely delivered to a specific area of the body during radiotherapy treatments.

Radiation tolerance varies depending on the type and location of the tissue or organ. For example, some tissues such as the brain, spinal cord, and lungs have lower radiation tolerance than others like the skin or bone. Factors that can affect radiation tolerance include the total dose of radiation, the fractionation schedule (the number and size of radiation doses), the volume of tissue treated, and the individual patient's overall health and genetic factors.

Assessing radiation tolerance is critical in designing safe and effective radiotherapy plans for cancer patients, as excessive radiation exposure can lead to serious side effects such as radiation-induced injury, fibrosis, or even secondary malignancies.

Alpha particles are a type of radiation that consist of two protons and two neutrons. They are essentially the nuclei of helium atoms and are produced during the decay of radioactive isotopes, such as uranium or radon. When an alpha particle is emitted from a radioactive atom, it carries away energy and causes the atom to transform into a different element with a lower atomic number and mass number.

Alpha particles have a positive charge and are relatively massive compared to other types of radiation, such as beta particles (which are high-energy electrons) or gamma rays (which are high-energy photons). Because of their charge and mass, alpha particles can cause significant ionization and damage to biological tissue. However, they have a limited range in air and cannot penetrate the outer layers of human skin, making them generally less hazardous than other forms of radiation if exposure is external.

Internal exposure to alpha-emitting radionuclides, however, can be much more dangerous because alpha particles can cause significant damage to cells and DNA when they are emitted inside the body. This is why inhaling or ingesting radioactive materials that emit alpha particles can pose a serious health risk.

Background radiation refers to the ionizing radiation that is present in the natural environment and originates from various sources, both natural and human-made. The term "background" indicates that this radiation exists as a constant presence that is always present, even if at low levels.

The primary sources of natural background radiation include:

1. Cosmic radiation: High-energy particles from space, such as protons and alpha particles, continuously bombard the Earth's atmosphere. When these particles collide with atoms in the atmosphere, they produce secondary particles called muons and neutrinos, which can penetrate through buildings and living tissues, contributing to background radiation exposure.
2. Terrestrial radiation: Radioactive elements present in the Earth's crust, such as uranium, thorium, and potassium-40, emit alpha and gamma radiation. These radioactive elements are found in rocks, soil, and building materials, leading to varying levels of background radiation depending on location.
3. Radon: A naturally occurring radioactive gas produced by the decay of radium, which is present in trace amounts in rocks and soil. Radon can accumulate in buildings, particularly in basements and crawl spaces, leading to increased exposure for occupants.

Human-made sources of background radiation include medical diagnostic procedures (e.g., X-rays and CT scans), consumer products (e.g., smoke detectors containing americium-241), and residual nuclear fallout from past nuclear weapons testing or accidents, such as the Chernobyl disaster.

It is important to note that background radiation levels vary significantly depending on location, altitude, geology, and other factors. While it is not possible to avoid background radiation entirely, understanding its sources and taking appropriate precautions when exposed to higher levels (e.g., limiting time in high radon areas) can help minimize potential health risks associated with ionizing radiation exposure.

Radiometry is the measurement of electromagnetic radiation, including visible light. It quantifies the amount and characteristics of radiant energy in terms of power or intensity, wavelength, direction, and polarization. In medical physics, radiometry is often used to measure therapeutic and diagnostic radiation beams used in various imaging techniques and cancer treatments such as X-rays, gamma rays, and ultraviolet or infrared light. Radiometric measurements are essential for ensuring the safe and effective use of these medical technologies.

Radiation-induced neoplasms are a type of cancer or tumor that develops as a result of exposure to ionizing radiation. Ionizing radiation is radiation with enough energy to remove tightly bound electrons from atoms or molecules, leading to the formation of ions. This type of radiation can damage DNA and other cellular structures, which can lead to mutations and uncontrolled cell growth, resulting in the development of a neoplasm.

Radiation-induced neoplasms can occur after exposure to high levels of ionizing radiation, such as that received during radiation therapy for cancer treatment or from nuclear accidents. The risk of developing a radiation-induced neoplasm depends on several factors, including the dose and duration of radiation exposure, the type of radiation, and the individual's genetic susceptibility to radiation-induced damage.

Radiation-induced neoplasms can take many years to develop after initial exposure to ionizing radiation, and they often occur at the site of previous radiation therapy. Common types of radiation-induced neoplasms include sarcomas, carcinomas, and thyroid cancer. It is important to note that while ionizing radiation can increase the risk of developing cancer, the overall risk is still relatively low, especially when compared to other well-established cancer risk factors such as smoking and exposure to certain chemicals.

Radiation-protective agents, also known as radioprotectors, are substances that help in providing protection against the harmful effects of ionizing radiation. They can be used to prevent or reduce damage to biological tissues, including DNA, caused by exposure to radiation. These agents work through various mechanisms such as scavenging free radicals, modulating cellular responses to radiation-induced damage, and enhancing DNA repair processes.

Radiation-protective agents can be categorized into two main groups:

1. Radiosensitizers: These are substances that make cancer cells more sensitive to the effects of radiation therapy, increasing their susceptibility to damage and potentially improving treatment outcomes. However, radiosensitizers do not provide protection to normal tissues against radiation exposure.

2. Radioprotectors: These agents protect both normal and cancerous cells from radiation-induced damage. They can be further divided into two categories: direct and indirect radioprotectors. Direct radioprotectors interact directly with radiation, absorbing or scattering it away from sensitive tissues. Indirect radioprotectors work by neutralizing free radicals and reactive oxygen species generated during radiation exposure, which would otherwise cause damage to cellular structures and DNA.

Examples of radiation-protective agents include antioxidants like vitamins C and E, chemical compounds such as amifostine and cysteamine, and various natural substances found in plants and foods. It is important to note that while some radiation-protective agents have shown promise in preclinical studies, their efficacy and safety in humans require further investigation before they can be widely used in clinical settings.

'Deinococcus' is a genus of bacteria that are characterized by their extreme resistance to various environmental stresses, such as radiation, desiccation, and oxidative damage. The most well-known species in this genus is Deinococcus radiodurans, which is often referred to as "conan the bacterium" because of its exceptional ability to survive high doses of ionizing radiation that would be lethal to most other organisms.

Deinococcus bacteria have a unique cell wall structure and contain multiple copies of their chromosome, which may contribute to their resistance to DNA damage. They are typically found in environments with high levels of radiation or oxidative stress, such as radioactive waste sites, dry deserts, and the gut of animals. While some species of Deinococcus have been shown to have potential applications in bioremediation and other industrial processes, others are considered opportunistic pathogens that can cause infections in humans with weakened immune systems.

According to the medical definition, ultraviolet (UV) rays are invisible radiations that fall in the range of the electromagnetic spectrum between 100-400 nanometers. UV rays are further divided into three categories: UVA (320-400 nm), UVB (280-320 nm), and UVC (100-280 nm).

UV rays have various sources, including the sun and artificial sources like tanning beds. Prolonged exposure to UV rays can cause damage to the skin, leading to premature aging, eye damage, and an increased risk of skin cancer. UVA rays penetrate deeper into the skin and are associated with skin aging, while UVB rays primarily affect the outer layer of the skin and are linked to sunburns and skin cancer. UVC rays are the most harmful but fortunately, they are absorbed by the Earth's atmosphere and do not reach the surface.

Healthcare professionals recommend limiting exposure to UV rays, wearing protective clothing, using broad-spectrum sunscreen with an SPF of at least 30, and avoiding tanning beds to reduce the risk of UV-related health problems.

Radioisotopes, also known as radioactive isotopes or radionuclides, are variants of chemical elements that have unstable nuclei and emit radiation in the form of alpha particles, beta particles, gamma rays, or conversion electrons. These isotopes are formed when an element's nucleus undergoes natural or artificial radioactive decay.

Radioisotopes can be produced through various processes, including nuclear fission, nuclear fusion, and particle bombardment in a cyclotron or other types of particle accelerators. They have a wide range of applications in medicine, industry, agriculture, research, and energy production. In the medical field, radioisotopes are used for diagnostic imaging, radiation therapy, and in the labeling of molecules for research purposes.

It is important to note that handling and using radioisotopes requires proper training, safety measures, and regulatory compliance due to their ionizing radiation properties, which can pose potential health risks if not handled correctly.

'Clostridium botulinum' is a gram-positive, rod-shaped, anaerobic bacteria that produces one or more neurotoxins known as botulinum toxins. These toxins are among the most potent naturally occurring biological poisons and can cause a severe form of food poisoning called botulism in humans and animals. Botulism is characterized by symmetrical descending flaccid paralysis, which can lead to respiratory and cardiovascular failure, and ultimately death if not treated promptly.

The bacteria are widely distributed in nature, particularly in soil, sediments, and the intestinal tracts of some animals. They can form spores that are highly resistant to heat, chemicals, and other environmental stresses, allowing them to survive for long periods in adverse conditions. The spores can germinate and produce vegetative cells and toxins when they encounter favorable conditions, such as anaerobic environments with appropriate nutrients.

Human botulism can occur through three main routes of exposure: foodborne, wound, and infant botulism. Foodborne botulism results from consuming contaminated food containing preformed toxins, while wound botulism occurs when the bacteria infect a wound and produce toxins in situ. Infant botulism is caused by the ingestion of spores that colonize the intestines and produce toxins, mainly affecting infants under one year of age.

Prevention measures include proper food handling, storage, and preparation practices, such as cooking and canning foods at appropriate temperatures and for sufficient durations. Wound care and prompt medical attention are crucial in preventing wound botulism. Vaccines and antitoxins are available for prophylaxis and treatment of botulism in high-risk individuals or in cases of confirmed exposure.

Radionuclide imaging, also known as nuclear medicine, is a medical imaging technique that uses small amounts of radioactive material, called radionuclides or radiopharmaceuticals, to diagnose and treat various diseases and conditions. The radionuclides are introduced into the body through injection, inhalation, or ingestion and accumulate in specific organs or tissues. A special camera then detects the gamma rays emitted by these radionuclides and converts them into images that provide information about the structure and function of the organ or tissue being studied.

Radionuclide imaging can be used to evaluate a wide range of medical conditions, including heart disease, cancer, neurological disorders, gastrointestinal disorders, and bone diseases. The technique is non-invasive and generally safe, with minimal exposure to radiation. However, it should only be performed by qualified healthcare professionals in accordance with established guidelines and regulations.

Ionizing radiation is a type of radiation that carries enough energy to ionize atoms or molecules, which means it can knock electrons out of their orbits and create ions. These charged particles can cause damage to living tissue and DNA, making ionizing radiation dangerous to human health. Examples of ionizing radiation include X-rays, gamma rays, and some forms of subatomic particles such as alpha and beta particles. The amount and duration of exposure to ionizing radiation are important factors in determining the potential health effects, which can range from mild skin irritation to an increased risk of cancer and other diseases.

Whole-Body Irradiation (WBI) is a medical procedure that involves the exposure of the entire body to a controlled dose of ionizing radiation, typically used in the context of radiation therapy for cancer treatment. The purpose of WBI is to destroy cancer cells or suppress the immune system prior to a bone marrow transplant. It can be delivered using various sources of radiation, such as X-rays, gamma rays, or electrons, and is carefully planned and monitored to minimize harm to healthy tissues while maximizing the therapeutic effect on cancer cells. Potential side effects include nausea, vomiting, fatigue, and an increased risk of infection due to decreased white blood cell counts.

'Elasmobranchii' is a superorder in the class Chondrichthyes, which includes all sharks, skates, rays, and sawfishes. This group is characterized by several distinct features, including:

1. Cartilaginous skeletons: Unlike bony fishes, elasmobranchs have skeletons made of cartilage rather than bone.
2. Five to seven gill slits: Most elasmobranchs have five pairs of gill slits on each side of their body, although some species may have six or seven pairs. These gill slits are open to the outside environment and lack protective covers found in bony fishes.
3. Heterocercal tail: Elasmobranchs possess a unique tail structure called a heterocercal tail, where the upper lobe is longer than the lower lobe. This tail design provides powerful propulsion and maneuverability in the water.
4. Dermal denticles: The skin of elasmobranchs is covered with small, tooth-like structures called dermal denticles, which provide a protective covering and reduce friction while swimming.
5. No swim bladders: Unlike bony fishes, elasmobranchs do not have a gas-filled swim bladder to help maintain buoyancy. Instead, they rely on their large liver, which contains low-density oil, to provide some degree of buoyancy.
6. Electrosensory organs: Many elasmobranchs possess specialized sensory organs called the ampullae of Lorenzini, which allow them to detect electric fields generated by living organisms and other environmental sources. This ability aids in hunting, navigation, and communication.
7. Carnivorous diet: Elasmobranchs are primarily carnivorous, feeding on various marine animals such as fish, squid, and crustaceans. Some species may also consume smaller elasmobranchs.
8. Live birth or egg laying: Most elasmobranchs reproduce by giving live birth (viviparity), where the embryos develop inside the mother's body and receive nourishment through a placenta-like structure. However, some species lay eggs (oviparity) in protective cases called mermaid's purses.
9. Slow growth and late maturity: Elasmobranchs generally grow slowly and reach sexual maturity at a relatively advanced age compared to many bony fishes. This slow life history makes them particularly vulnerable to overfishing and other human-induced threats.

DNA repair is the process by which cells identify and correct damage to the DNA molecules that encode their genome. DNA can be damaged by a variety of internal and external factors, such as radiation, chemicals, and metabolic byproducts. If left unrepaired, this damage can lead to mutations, which may in turn lead to cancer and other diseases.

There are several different mechanisms for repairing DNA damage, including:

1. Base excision repair (BER): This process repairs damage to a single base in the DNA molecule. An enzyme called a glycosylase removes the damaged base, leaving a gap that is then filled in by other enzymes.
2. Nucleotide excision repair (NER): This process repairs more severe damage, such as bulky adducts or crosslinks between the two strands of the DNA molecule. An enzyme cuts out a section of the damaged DNA, and the gap is then filled in by other enzymes.
3. Mismatch repair (MMR): This process repairs errors that occur during DNA replication, such as mismatched bases or small insertions or deletions. Specialized enzymes recognize the error and remove a section of the newly synthesized strand, which is then replaced by new nucleotides.
4. Double-strand break repair (DSBR): This process repairs breaks in both strands of the DNA molecule. There are two main pathways for DSBR: non-homologous end joining (NHEJ) and homologous recombination (HR). NHEJ directly rejoins the broken ends, while HR uses a template from a sister chromatid to repair the break.

Overall, DNA repair is a crucial process that helps maintain genome stability and prevent the development of diseases caused by genetic mutations.

DNA damage refers to any alteration in the structure or composition of deoxyribonucleic acid (DNA), which is the genetic material present in cells. DNA damage can result from various internal and external factors, including environmental exposures such as ultraviolet radiation, tobacco smoke, and certain chemicals, as well as normal cellular processes such as replication and oxidative metabolism.

Examples of DNA damage include base modifications, base deletions or insertions, single-strand breaks, double-strand breaks, and crosslinks between the two strands of the DNA helix. These types of damage can lead to mutations, genomic instability, and chromosomal aberrations, which can contribute to the development of diseases such as cancer, neurodegenerative disorders, and aging-related conditions.

The body has several mechanisms for repairing DNA damage, including base excision repair, nucleotide excision repair, mismatch repair, and double-strand break repair. However, if the damage is too extensive or the repair mechanisms are impaired, the cell may undergo apoptosis (programmed cell death) to prevent the propagation of potentially harmful mutations.

Chromosome aberrations refer to structural and numerical changes in the chromosomes that can occur spontaneously or as a result of exposure to mutagenic agents. These changes can affect the genetic material encoded in the chromosomes, leading to various consequences such as developmental abnormalities, cancer, or infertility.

Structural aberrations include deletions, duplications, inversions, translocations, and rings, which result from breaks and rearrangements of chromosome segments. Numerical aberrations involve changes in the number of chromosomes, such as aneuploidy (extra or missing chromosomes) or polyploidy (multiples of a complete set of chromosomes).

Chromosome aberrations can be detected and analyzed using various cytogenetic techniques, including karyotyping, fluorescence in situ hybridization (FISH), and comparative genomic hybridization (CGH). These methods allow for the identification and characterization of chromosomal changes at the molecular level, providing valuable information for genetic counseling, diagnosis, and research.

Radiation injuries refer to the damages that occur to living tissues as a result of exposure to ionizing radiation. These injuries can be acute, occurring soon after exposure to high levels of radiation, or chronic, developing over a longer period after exposure to lower levels of radiation. The severity and type of injury depend on the dose and duration of exposure, as well as the specific tissues affected.

Acute radiation syndrome (ARS), also known as radiation sickness, is the most severe form of acute radiation injury. It can cause symptoms such as nausea, vomiting, diarrhea, fatigue, fever, and skin burns. In more severe cases, it can lead to neurological damage, hemorrhage, infection, and death.

Chronic radiation injuries, on the other hand, may not appear until months or even years after exposure. They can cause a range of symptoms, including fatigue, weakness, skin changes, cataracts, reduced fertility, and an increased risk of cancer.

Radiation injuries can be treated with supportive care, such as fluids and electrolytes replacement, antibiotics, wound care, and blood transfusions. In some cases, surgery may be necessary to remove damaged tissue or control bleeding. Prevention is the best approach to radiation injuries, which includes limiting exposure through proper protective measures and monitoring radiation levels in the environment.

'C3H' is the name of an inbred strain of laboratory mice that was developed at the Jackson Laboratory in Bar Harbor, Maine. The mice are characterized by their uniform genetic background and have been widely used in biomedical research for many decades.

The C3H strain is particularly notable for its susceptibility to certain types of cancer, including mammary tumors and lymphomas. It also has a high incidence of age-related macular degeneration and other eye diseases. The strain is often used in studies of immunology, genetics, and carcinogenesis.

Like all inbred strains, the C3H mice are the result of many generations of brother-sister matings, which leads to a high degree of genetic uniformity within the strain. This makes them useful for studying the effects of specific genes or environmental factors on disease susceptibility and other traits. However, it also means that they may not always be representative of the genetic diversity found in outbred populations, including humans.

A mutation is a permanent change in the DNA sequence of an organism's genome. Mutations can occur spontaneously or be caused by environmental factors such as exposure to radiation, chemicals, or viruses. They may have various effects on the organism, ranging from benign to harmful, depending on where they occur and whether they alter the function of essential proteins. In some cases, mutations can increase an individual's susceptibility to certain diseases or disorders, while in others, they may confer a survival advantage. Mutations are the driving force behind evolution, as they introduce new genetic variability into populations, which can then be acted upon by natural selection.

In the field of medicine, "time factors" refer to the duration of symptoms or time elapsed since the onset of a medical condition, which can have significant implications for diagnosis and treatment. Understanding time factors is crucial in determining the progression of a disease, evaluating the effectiveness of treatments, and making critical decisions regarding patient care.

For example, in stroke management, "time is brain," meaning that rapid intervention within a specific time frame (usually within 4.5 hours) is essential to administering tissue plasminogen activator (tPA), a clot-busting drug that can minimize brain damage and improve patient outcomes. Similarly, in trauma care, the "golden hour" concept emphasizes the importance of providing definitive care within the first 60 minutes after injury to increase survival rates and reduce morbidity.

Time factors also play a role in monitoring the progression of chronic conditions like diabetes or heart disease, where regular follow-ups and assessments help determine appropriate treatment adjustments and prevent complications. In infectious diseases, time factors are crucial for initiating antibiotic therapy and identifying potential outbreaks to control their spread.

Overall, "time factors" encompass the significance of recognizing and acting promptly in various medical scenarios to optimize patient outcomes and provide effective care.

I could not find a medical definition for "animal fins" as a single concept. However, in the field of comparative anatomy and evolutionary biology, fins are specialized limbs that some aquatic animals use for movement, stability, or sensory purposes. Fins can be found in various forms among different animal groups, including fish, amphibians, reptiles, and even mammals like whales and dolphins.

Fins consist of either bony or cartilaginous structures that support webs of skin or connective tissue. They may contain muscles, blood vessels, nerves, and sensory organs, which help animals navigate their underwater environment efficiently. The specific structure and function of fins can vary greatly depending on the animal's taxonomic group and lifestyle adaptations.

In a medical context, studying animal fins could provide insights into the evolution of limbs in vertebrates or contribute to the development of biomimetic technologies inspired by nature. However, there is no standalone medical definition for 'animal fins.'

Lymphocytes are a type of white blood cell that is an essential part of the immune system. They are responsible for recognizing and responding to potentially harmful substances such as viruses, bacteria, and other foreign invaders. There are two main types of lymphocytes: B-lymphocytes (B-cells) and T-lymphocytes (T-cells).

B-lymphocytes produce antibodies, which are proteins that help to neutralize or destroy foreign substances. When a B-cell encounters a foreign substance, it becomes activated and begins to divide and differentiate into plasma cells, which produce and secrete large amounts of antibodies. These antibodies bind to the foreign substance, marking it for destruction by other immune cells.

T-lymphocytes, on the other hand, are involved in cell-mediated immunity. They directly attack and destroy infected cells or cancerous cells. T-cells can also help to regulate the immune response by producing chemical signals that activate or inhibit other immune cells.

Lymphocytes are produced in the bone marrow and mature in either the bone marrow (B-cells) or the thymus gland (T-cells). They circulate throughout the body in the blood and lymphatic system, where they can be found in high concentrations in lymph nodes, the spleen, and other lymphoid organs.

Abnormalities in the number or function of lymphocytes can lead to a variety of immune-related disorders, including immunodeficiency diseases, autoimmune disorders, and cancer.

A Cathode Ray Tube (CRT) is a vacuum tube that contains one or more electron guns and a fluorescent screen used to view images. In a CRT, the electron gun emits a beam of electrons that are accelerated towards the fluorescent screen. The electrons strike the phosphor-coated screen, causing it to emit light and create images.

CRTs were commonly used in older television sets and computer monitors before being replaced by flat-panel displays such as LCDs and plasmas. CRTs are still used in some medical equipment, such as cathode ray oscilloscopes and X-ray imaging systems.

Cell survival refers to the ability of a cell to continue living and functioning normally, despite being exposed to potentially harmful conditions or treatments. This can include exposure to toxins, radiation, chemotherapeutic drugs, or other stressors that can damage cells or interfere with their normal processes.

In scientific research, measures of cell survival are often used to evaluate the effectiveness of various therapies or treatments. For example, researchers may expose cells to a particular drug or treatment and then measure the percentage of cells that survive to assess its potential therapeutic value. Similarly, in toxicology studies, measures of cell survival can help to determine the safety of various chemicals or substances.

It's important to note that cell survival is not the same as cell proliferation, which refers to the ability of cells to divide and multiply. While some treatments may promote cell survival, they may also inhibit cell proliferation, making them useful for treating diseases such as cancer. Conversely, other treatments may be designed to specifically target and kill cancer cells, even if it means sacrificing some healthy cells in the process.

Interferon-gamma (IFN-γ) is a soluble cytokine that is primarily produced by the activation of natural killer (NK) cells and T lymphocytes, especially CD4+ Th1 cells and CD8+ cytotoxic T cells. It plays a crucial role in the regulation of the immune response against viral and intracellular bacterial infections, as well as tumor cells. IFN-γ has several functions, including activating macrophages to enhance their microbicidal activity, increasing the presentation of major histocompatibility complex (MHC) class I and II molecules on antigen-presenting cells, stimulating the proliferation and differentiation of T cells and NK cells, and inducing the production of other cytokines and chemokines. Additionally, IFN-γ has direct antiproliferative effects on certain types of tumor cells and can enhance the cytotoxic activity of immune cells against infected or malignant cells.

A gamma decay was then understood to usually emit a gamma photon. Natural sources of gamma rays on Earth include gamma decay ... Extraterrestrial, high energy gamma rays include the gamma ray background produced when cosmic rays (either high speed ... Thunderstorms can produce a brief pulse of gamma radiation called a terrestrial gamma-ray flash. These gamma rays are thought ... followed by beta rays, followed by gamma rays as the most penetrating. Rutherford also noted that gamma rays were not deflected ...
... or Gamma Ray Observatory can refer to: Any observatory used for gamma ray astronomy. The Compton Gamma ... This disambiguation page lists articles associated with the title Gamma ray observatory. If an internal link led you here, you ... Ray Observatory, an observatory that operated from 1991 to 2000. ...
... s have the most relativistic jets known in the universe, being ultrarelativistic. The matter in gamma-ray burst ... "Gamma Rays". NASA. Archived from the original on 2012-05-02. Atkinson, Nancy (2013-04-16). "New Kind of Gamma Ray Burst is ... Paczyński, B. (1999). "Gamma-Ray Burst-Supernova relation". In M. Livio; N. Panagia; K. Sahu (eds.). Supernovae and Gamma-Ray ... In gamma-ray astronomy, gamma-ray bursts (GRBs) are immensely energetic explosions that have been observed in distant galaxies ...
... "gamma-ray" when used as an adjective, but uses "gamma ray" without a hyphen for the noun. "EGRET Detection of Gamma Rays from ... but also observed gamma-ray bursts. By identifying the first non-gamma ray counterparts to gamma-ray bursts, it opened the way ... the Gamma-Ray Burst Monitor, for studying gamma-ray bursts. In November 2010, using the Fermi Gamma-ray Space Telescope, two ... Cosmic-ray observatory Galactic Center GeV excess Gamma-ray Burst Coordinates Network History of gamma-ray burst research ...
A gamma-ray laser, or graser, is a hypothetical device that would produce coherent gamma rays, just as an ordinary laser ... In his 2003 Nobel lecture, Vitaly Ginzburg cited the gamma-ray laser as one of the 30 most important problems in physics. The ... Baldwin, G. C.; Solem, J. C.; Gol'danskii, V. I. (1981). "Approaches to the development of gamma-ray lasers". Reviews of Modern ... Baldwin, G. C.; Solem, J. C. (1980). "Two-stage pumping of three-level Mössbauer gamma-ray lasers". Journal of Applied Physics ...
Wikimedia Commons has media related to Gamma Ray (musical group). Official website Gamma Ray discography at MusicBrainz Gamma ... "GAMMA RAY Hires FRANK BECK As Its New Lead Singer". Blabbermouth.net. 31 October 2015. Retrieved 20 December 2018. "GAMMA RAY ... "Gamma Ray - To the Metal! (album review 2)". Sputnikmusic. 28 January 2010. Retrieved 20 December 2018. "GAMMA RAY: 'Skeletons ... "GAMMA RAY ANNOUNCE 25TH ANNIVERSARY REISSUE OF "ALIVE '95"". Gammaray.org. "A conversation with Kai Hansen (Helloween/ Gamma ...
Look up gamma ray or gamma-ray in Wiktionary, the free dictionary. Gamma rays are a form of electromagnetic radiation. Gamma ... "Gamma Ray" (song), by Beck "Gamma Ray", a song by the German progressive rock band Birth Control "Gamma Ray", a song by Circa ... Ray may also refer to: Gamma Ray (band), a German power metal band Gamma Ray (EP), extended play recording by Queens of the ... This disambiguation page lists articles associated with the title Gamma ray. If an internal link led you here, you may wish to ...
The Gamma-Ray Imaging Spectrometer, the Hard X-ray/Low-Energy Gamma-ray experiment (A-4) on HEAO 1, the Burst and Transient ... The study and analysis of gamma-ray spectra for scientific and technical use is called gamma spectroscopy, and gamma-ray ... How are gamma rays and neutrons produced by cosmic rays? Incoming cosmic rays-some of the highest-energy particles-collide with ... gamma-ray instrument on HEAO 3, and the Ge gamma-ray spectrometer (SPI) on the ESA INTEGRAL mission are examples of cosmic ...
... while a spectral gamma ray log (see below) can. For standard gamma-ray logs, the measured value of gamma-ray radiation is ... Gamma ray energy 2.61 MeV Uranium-Radium series: Gamma ray energy 1.76 MeV Another example of the use of spectral gamma ray ... Thus gamma ray logs cannot be said to make good lithological logs by themselves, but in practice, gamma ray logs are compared ... The characteristic gamma ray line that is associated with each radioactive component: Potassium : Gamma ray energy 1.46 MeV ...
A) "Gamma Ray" (2:58) "Gamma Ray" (2:59) (cover by Jay Reatard) (B) "Gamma Ray" (2:58) "Bonfire Blondes" (2:25) Beck Hansen - ... "Gamma Ray (Jay Reatard Version) - Single by Beck - Download Gamma Ray (Jay Reatard Version) - Single on iTunes". Phobos.apple. ... "Gamma Ray" is a song by American rock musician Beck. It was released as the second single from his eighth studio album, Modern ... "Beck: Gamma Ray b,w Bonfire Blondes: 7". Insound.com. Archived from the original on 2009-01-30. Retrieved 2010-09-21. "Beck ...
Gamma Ray is the debut EP by Gamma Ray, a musical project by former Kyuss guitarist Josh Homme, released in 1996 by Man's Ruin ... recording engineer Gamma Ray (EP liner notes). Gamma Ray. San Francisco: Man's Ruin Records. 1996. MR 036.{{cite AV media notes ... He changed the name of the project to Queens of the Stone Age, and both of the Gamma Ray tracks were re-released the following ... After the breakup of Kyuss in 1995, Homme recorded the Gamma Ray material in Seattle with producer Chris Goss, bassist Van ...
"Gamma Ray - To The Metal!". ultratop.be. Retrieved 2012-02-17. Steffen Hung (2010-02-14). "The Official Swiss Charts and Music ... "Gamma Ray Suchergebnisse in den deutschen Charts". Charts.de (in German). Media Control Charts. Retrieved 2011-08-30.[dead link ... "Gamma Ray - To The Metal!". greekcharts.com. Archived from the original on 2012-08-30. Retrieved 2012-02-17. "Chartpositions " ... This is a discography of Gamma Ray, a German heavy metal band, formed in 1988 in Hamburg, Germany. They have released eleven ...
Gamma-ray detected by Gamma-ray detector in an oil or gas wells, is not only a function of radioactivity of the formations, but ... Gamma-ray measurement has the following applications: Well to well correlation: gamma-ray log fluctuates with changes in ... The spectrum of the gamma-rays emitted by these two isotopes consists of gamma-ray of many different energies and form a ... Gamma ray logging Gamma ray Formation evaluation Ellis, Darwin V. (1987). Well Logging for Earth Scientists. Amsterdam: ...
A terrestrial gamma-ray flash (TGF), also known as dark lightning, is a burst of gamma rays produced in Earth's atmosphere. ... In 2009, the Fermi Gamma-ray Space Telescope in Earth orbit observed intense burst of gamma rays corresponding to positron ... Wikimedia Commons has media related to Terrestrial gamma-ray flashes. Gamma-ray bursts Red sprite Blue jet Lightning Palmer, ... Cohen, M. B.; Inan, U. S.; Fishman, G. (2006). "Terrestrial gamma ray flashes observed aboard the Compton Gamma Ray Observatory ...
"Gamma-Ray Astronomy in the Compton Era: The Instruments". Gamma-Ray Astronomy in the Compton Era. NASA/ GSFC. Archived from the ... The Energetic Gamma Ray Experiment Telescope (EGRET) measured high energy (20 MeV to 30 GeV) gamma-ray source positions to a ... Wikimedia Commons has media related to Compton Gamma Ray Observatory. NASA Compton Gamma Ray Observatory site NASA CGRO images ... NASA's Swift Gamma-Ray Burst Mission (launched 2004), ASI AGILE (satellite) (launched 2007) and NASA's Fermi Gamma-ray Space ...
"Lescharts.com - Gamma Ray - Majestic". Hung Medien. Retrieved 12 September 2020. "Offiziellecharts.de - Gamma Ray - Majestic" ( ... Henjo Richter GAMMA RAY: Japanese Version Of 'Majestic' To Include Bonus Track Retrieved November 1, 2017 "Gamma Ray - Majestic ... Gamma Ray - Majestic". Hung Medien. Retrieved 12 September 2020. "Swedishcharts.com - Gamma Ray - Majestic". Hung Medien. ... Majestic is the eighth full-length studio album from the German power metal band Gamma Ray, released in 2005. The band also ...
A gamma-ray precursor is a short X-ray outburst event that comes before the main outburst of the gamma-ray burst progenitor. ... Articles with short description, Short description matches Wikidata, Gamma-ray bursts, Gamma-ray astronomy). ... Notably, the first gamma-ray precursor to be detected showed a thermal spectrum, with a peak in the X-ray wavelengths. There is ... The first gamma-ray precursor event was from GRB 900126, a long GRB. Immediately, because of the non-thermal nature of the ...
The Gamma-Ray Imaging Spectrometer (GRIS) was a gamma-ray spectrometer instrument on a balloon-borne airborne observatory. It ... "The Gamma-Ray Imaging Spectrometer (GRIS): A new balloon-borne experiment for gamma-ray line astronomy". 19th Intern. Cosmic ... "arguably one of the most successful gamma-ray balloon programs in history". GRIS followed earlier gamma ray spectroscopy work ... after the removal of a high-resolution gamma-ray spectrometer from the payload of what would become the Compton Gamma Ray ...
The path of the gamma-rays can be reconstructed using a tracking algorithm. Multi Geometry Simulation is one of the most ... Reconstructing the path of the γ-ray interaction is one of the main problems of the γ-ray tracking. There are several proposed ... AGATA, for advanced gamma tracking array, is a highly segmented High Purity Germanium (HPGe) detector array. It is a European ... To determine the position of the interaction of the γ-ray one needs to consider the shapes of the induced real and mirror ...
... are the types of celestial objects that can emit gamma-ray bursts (GRBs). GRBs show an ... Gamma-ray burst emission mechanisms Quark-nova Ruderman, M. (1975). "Theories of gamma-ray bursts". Texas Symposium on ... 2005). "Bright X-ray Flares in Gamma-Ray Burst Afterglows". Science. 309 (5742): 1833-1835. arXiv:astro-ph/0506130. Bibcode: ... To date, three gamma-ray bursts have been associated with SGR flares in galaxies beyond the Milky Way: GRB 790305b in the Large ...
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Since lower energy gamma rays cannot be accurately detected on Earth's surface, EGRET was built to detect gamma rays while in ... "Energetic gamma ray experiment telescope high-energy gamma ray observations of the Moon and quiet Sun." JOURNAL OF GEOPHYSICAL ... "Energetic gamma ray experiment telescope high-energy gamma ray observations of the Moon and quiet Sun." Journal of Geophysical ... The Energetic Gamma Ray Experiment Telescope (EGRET) was one of four instruments outfitted on NASA's Compton Gamma Ray ...
2 - March 2000 (accessed 2009/11/11) Connors, A. (1998). "The X-Ray Characteristics of a Classical Gamma-Ray Burst and Its ... "The Incredible Gamma Ray Burst of 2008" (PDF). Archived from the original (PDF) on 2012-02-22. Retrieved 2009-11-17. (922 KB), ... The ING Newsletter, "Gamma-Ray Burst Afterglows: Surprises from the Sky", P. Vreeswijk, N. Tanvir, T. Galama, No. ... 2014). "GRB 140515A at z=6.33: Constraints on the End of Reionization from a Gamma-ray Burst in a Low Hydrogen Column Density ...
... are theories that explain how the energy from a gamma-ray burst progenitor (regardless of ... Gamma-ray burst emission is believed to be released in jets, not spherical shells. Initially the two scenarios are equivalent: ... As of 2007 there is no theory that has successfully described the spectrum of all gamma-ray bursts (though some theories work ... Sari, R.; Piran, T.; Halpern, J. P. (1999). "Jets in Gamma-Ray Bursts". Astrophysical Journal. 519 (1): L17-L20. arXiv:astro-ph ...
The ratio of primary cosmic ray hadrons to gamma rays also gives a clue as to the origin of cosmic rays. Although gamma rays ... Sources that produce cosmic rays will almost certainly produce gamma rays as well, as the cosmic ray particles interact with ... Very-high-energy gamma rays are of importance because they may reveal the source of cosmic rays. They travel in a straight line ... Very-high-energy gamma ray (VHEGR) denotes gamma radiation with photon energies of 100 GeV (gigaelectronvolt) to 100 TeV ( ...
"Austriancharts.at - Gamma Ray - Power Plant" (in German). Hung Medien. Retrieved 12 September 2020. "Gamma Ray: Power Plant" ( ... "Gamma Ray - Power Plant review". Metal Storm. Retrieved 27 March 2021. Stagno, Mike (27 October 2006). "Gamma Ray - Power Plant ... Power Plant is the sixth full-length album from the German power metal band, Gamma Ray. The album was initially released in ... "Gamma Ray - Power Plant review". AllMusic. All Media Network. Retrieved 19 May 2021. Popoff, Martin (1 August 2007). The ...
The Gamma-ray Burst Monitor (GBM) (formerly GLAST Burst Monitor) detects sudden flares of gamma-rays produced by gamma ray ... Galactic gamma- and X-ray bubbles In November 2010, it was announced that two gamma-ray and X-ray emitting bubbles were ... Gamma-ray bursts Study gamma-ray bursts with an energy range several times more intense than ever before so that scientists may ... The Fermi Gamma-ray Space Telescope (FGST, also FGRST), formerly called the Gamma-ray Large Area Space Telescope (GLAST), is a ...
The ratio of primary cosmic ray hadrons to gamma rays also gives a clue as to the origin of cosmic rays. Although gamma rays ... Ultra-high-energy gamma rays are gamma rays with photon energies higher than 100 TeV (0.1 PeV). They have a frequency higher ... The authors of the report have named the sources of these PeV gamma rays PeVatrons. Ultra-high-energy gamma rays are of ... Sources that produce cosmic rays will almost certainly produce gamma rays as well, as the cosmic ray particles interact with ...
He would go on to appear on every Gamma Ray record to date. Also making his first appearance with the band was Uli Kusch, who ... Heaven Can Wait was an EP released by German power metal band Gamma Ray in 1990, following the release of their debut album ... Gamma Ray (band) albums, 1990 EPs, Albums produced by Kai Hansen). ...
The Gamma Ray Spectrometer (GRS) is a gamma-ray spectrometer on the 2001 Mars Odyssey spacecraft, a space probe orbiting the ... The Gamma Ray Spectrometer weighs 30.5 kilograms (67 lb) and uses 32 watts of power. Along with its cooler, it measures 468 by ... "The Mars Odyssey Gamma-Ray Spectrometer Instrument Suite". Space Science Reviews. 110 (1-2): 37. Bibcode:2004SSRv..110...37B. ... "Gamma Ray Spectrometer : Latest Results". Lunar and Planetary Laboratory, University of Arizona. January 2008. Archived from ...
A gamma decay was then understood to usually emit a gamma photon. Natural sources of gamma rays on Earth include gamma decay ... Extraterrestrial, high energy gamma rays include the gamma ray background produced when cosmic rays (either high speed ... Thunderstorms can produce a brief pulse of gamma radiation called a terrestrial gamma-ray flash. These gamma rays are thought ... followed by beta rays, followed by gamma rays as the most penetrating. Rutherford also noted that gamma rays were not deflected ...
For gamma-ray bursts of cosmic origin, see Gamma-ray burst.. Artists conception of gamma-ray flash and related phenomena.. The ... 500 terrestrial gamma-ray flashes daily detected by the Fermi Gamma-ray Space Telescope through 2010.. A terrestrial gamma-ray ... Energy plot of a typical TGF event, with artists conception of a gamma-ray flash superimposed.[2]. Terrestrial gamma-ray ... In 2009, the Fermi Gamma-ray Space Telescope in Earth orbit observed intense burst of gamma rays corresponding to positron ...
All the latest gamma ray detector news, videos, and more from the worlds leading engineering magazine. ... gamma ray detector News & Articles. Showing 1 posts that have the tag "gamma-ray-detector" ...
Scientists may have solved one of astronomys major puzzles: the origin of powerful gamma-ray bursts. ... "All gamma-ray bursts may have associated supernovae that are too faint to observe," says Matheson, who believes that because ... "There should no longer be doubt in anybodys mind that gamma-ray bursts and supernovae are connected," says Thomas Matheson, of ... Located in the constellation of Leo, the 30-second burst, designated GRB 030329, outshone the entire Universe in gamma rays. ...
He covers in detail his discovery of the positive electron, his pair production work with gamma rays, his expedition to Pikes ... She recounts her work in extraterrestrial physics at the Max Planck Institute and she describes the origins of gamma ray ... After noting the absence of any cosmic ray work during the war years, he mentions the postwar development of cosmic ray work ... Astronomy and Education where she worked with data from the BATSE project and continued research on gamma ray bursts. She ...
The launch of a new NASA telescope that can detect gamma rays could give astronomers their first peek at dark matter ... In December, NASA will launch the Gamma-ray Large Area Space Telescope (GLAST), which could in theory detect gamma rays coming ... Take away all the known sources of gamma rays in the universe, and you might be left with the above picture - something a new ... From this they created an all-sky gamma-ray map (above), showing only what can be expected from that dark matter (www.arxiv.org ...
Home Computers Discover Gamma-Ray Pulsars. Gamma-ray pulsars in the Milky Ways plane, found by volunteers using Einstein@Home ... Artists conception of a gamma-ray pulsar. Gamma rays are shown in purple, and radio radiation in green. Credit: NASA/Fermi/ ... it would radiate at a specific wavelength of gamma rays. So if they exist, a gamma ray telescope should be able to observe them ... Tag: gamma ray astronomy. Posted on February 10, 2014. December 23, 2015. by Brian Koberlein ...
Podcast: Gamma Ray Bursts. Gamma ray bursts are the most powerful explosions in the Universe, releasing more energy in a few ...
... not all gamma-ray bursts have such comments. Comments_Position. Comments on the gamma-ray burst coordinates: not all gamma-ray ... BATSEGRB - CGRO/BATSE Gamma-Ray Burst Catalog. HEASARC. Archive. Overview. This database table comprises the gamma-ray bursts ... Comments on the gamma-ray burst duration: not all gamma-ray bursts have such comments. Contact Person. Questions regarding the ... The Fourth BATSE Gamma-Ray Burst Catalog, C. A. Meegan et al., in Gamma-Ray Bursts: the Fourth Huntsville Symposium (IAP No. ...
When this happens, one byproduct is gamma rays. The energy of the gamma rays keeps the suns core hot. Some of those gamma rays ... Alpha rays bounce right off, beta rays went a little farther, and gamma rays went the farthest. Today we know alpha rays are ... Some gamma rays come from thunderstorms.. In the 1990s, observatories in space detected bursts of gamma rays coming from Earth ... The name "gamma rays" came from Ernest Rutherford.. French chemist Paul Villard first identified gamma rays in 1900 from the ...
Researchers using NASAs Fermi Gamma-ray Space Telescope have discovered the first gamma-ray pulsar in a galaxy other than our ... NASAs Fermi satellite detects first gamma-ray pulsar in another galaxy 13 November 2015 Astronomy Now ... Known as PSR J0540-6919, the object sets a new record for the most luminous gamma-ray pulsar known. The pulsar lies in the ...
Supermassive black holes, even if they are not so active, can be major factories of high-energy cosmic particles in the universe, according to a new model.
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Mackey, E. , Becker, P. , Lindstrom, R. and Anderson, D. (2005), Sources of Uncertainties in Prompt Gamma-Ray Activation ... www.nist.gov/publications/sources-uncertainties-prompt-gamma-ray-activation-analysis ...
A rare, extremely energetic cosmic ray has mysterious origins By Emily Conover. November 23, 2023. ... A rare, extremely energetic cosmic ray has mysterious origins By Emily Conover. November 23, 2023. ...
ESA Science & Technology - INTEGRAL - ESAs gamma-ray observatory. * Missions * Show All Missions ... INTEGRAL - ESAs gamma-ray observatory. WMV file: https://cdn.sci.esa.int/documents/34439/36072/1567245685636-224_intgfin_ ...
Gamma Ray Bursts What is a Gamma Ray Burst?. A gamma-ray burst (GRB) is a brief flash of gamma rays coming from an ... Gamma rays are a kind of light (like visible light, microwaves, or X-rays) that is very energetic, and whatever produces gamma ... rays must therefore contain (and unleash) a large amount of energy in a very short amount of time. Thus the study of gamma ray ...
Gamma-ray astronomy is a branch of astronomy that deals with the detection and study of gamma rays in the cosmos. Gamma rays ... but also observed gamma-ray bursts. By identifying the first non-gamma ray counterparts to gamma-ray bursts, it opened the way ... the main space-based gamma-ray observatories are the INTErnational Gamma-Ray Astrophysics Laboratory, (INTEGRAL), and the Gamma ... Most of the gamma rays coming from space are absorbed by the Earths atmosphere. For this reason, the development of gamma-ray ...
Gamma Ray All Sky Map Picture Credit: NASA, Compton Gamma Ray Observatory Explanation: What if you could "see" gamma rays? This ... A diffuse gamma-ray glow from the plane of our Milky Way Galaxy is clearly seen across the middle. The nature and even distance ... These gamma-ray photons are more than 40 million times more energetic than visible light photons and are blocked from the ... In the early 1990s NASAs Compton Gamma Ray Observatory, in orbit around the Earth, scanned the entire sky to produce this ...
Astronomers have for the first time probed the magnetic fields in the mysterious inner regions of stars, finding they are strongly magnetised. Using a technique called asteroseismology, the scientists were able to calculate the magnetic field strengths in the fusion-powered hearts of dozens of red giants, stars that are evolved versions of our Sun. ...
... www.astronomy.com/science/gamma-rays-illuminate-one-of-the-milky-ways-weirdest-objects/ Gamma rays illuminate one of the Milky ... HAWC can study about 15 percent of the sky at once, scanning for the "air showers" that result when gamma rays and cosmic rays ... "Thus, we [will] combine all of its signals, from low energy radio to X-ray, with new high-energy gamma ray observations, to ... Gamma rays illuminate one of the Milky Ways weirdest objects. In a first, astronomers have discovered how the tiny cousins of ...
... and the gamma-ray burst (GRB) GRB 170817A was observed independently by the Fermi Gamma-ray Burst Monitor, and the ... and the gamma-ray burst (GRB) GRB 170817A was observed independently by the Fermi Gamma-ray Burst Monitor, and the ... We also use the time delay to constrain the size and bulk Lorentz factor of the region emitting the gamma rays. GRB 170817A is ... Gravitational Waves and Gamma-Rays from a Binary Neutron Star Merger: GW170817 and GRB 170817A. * ...
Azimuthal Gamma Ray and Inclination Service offers a cost-effective geosteering solution for unconventional reservoirs. ...
Gamma-ray burst after gravitational waves. Date: 16 October 2017. Satellite: INTEGRAL. Copyright: ESA/INTEGRAL/SPI/ISDC. Show ... ESA Science & Technology - Gamma-ray burst after gravitational waves. * Missions * Show All Missions ... The intensity of gamma rays measured by ESA's INTEGRAL satellite on 17 August 2017. ... The observations indicated that the gravitational waves and the gamma-ray burst originate from the same cosmic event: the ...
... instrument designed to detect and resolve gamma rays from sources outside Earths atmosphere. Gamma rays are the shortest waves ... Since gamma rays have so much energy, they pass ... Earths atmosphere blocks most gamma rays, so most gamma-ray ... Since gamma rays have so much energy, they pass right through the mirror of a standard optical telescope. Instead, gamma rays ... gamma-ray telescope, instrument designed to detect and resolve gamma rays from sources outside Earths atmosphere. ...
... posts including gamma ray from an archive of over two hundred thousand heavy metal and hard rock articles spanning over a ... GAMMA RAY Confirmed For UKs BLOODSTOCK Festival. German power metallers GAMMA RAY are the latest act to have been confirmed ... GAMMA RAYs HENJO RICHTER Turns Down HELLOWEEN Offer. GAMMA RAY guitarist Henjo Richter will not be accepting HELLOWEENs offer ... GAMMA RAY, RAGE) in early May to begin recording their as-yet-untitled fourth full-length album for a late 2002 release through ...
The data was accumulated by NASAs Fermi Gamma-ray Space Telescope for five years. Brighter colours indicate brighter gamma-ray ...
Gamma-ray burst buried in dust (artists impression). An artists conception of the environment around GRB 020819B based on ...
Are gamma-ray bursts powered by a stars collapsing magnetic fields?. Groundbreaking research from Bath suggests the brightest ... These extremely bright gamma-ray bursts (GRBs) are the most powerful explosions in the universe, and when a jet points towards ... They were alerted to the stars collapse after its gamma-ray flash (named GRB 190114C) was detected by NASAs space-borne Neil ... The researchers noted a startlingly low level of polarisation in the gamma-ray burst in the moments straight after the stars ...
  • The red dots show some of the ~500 terrestrial gamma-ray flashes daily detected by the Fermi Gamma-ray Space Telescope through 2010. (wikipedia.org)
  • A few years later, scientists using NASA's Fermi Gamma-ray Space Telescope , which was designed to monitor gamma rays, estimated that about 500 TGFs occur daily worldwide, but most go undetected. (wikipedia.org)
  • In December, NASA will launch the Gamma-ray Large Area Space Telescope (GLAST), which could in theory detect gamma rays coming from the annihilation of neutralinos. (newscientist.com)
  • That's what happened to several volunteers with Einstein@Home, which seeks pulsars in data from the Fermi Gamma-Ray Space Telescope, among other projects . (universetoday.com)
  • Instead an observatory like the Fermi Gamma-ray Space Telescope detects the signal from gamma rays when they hit a detector and convert into pairs of electrons and positrons. (symmetrymagazine.org)
  • Researchers using NASA's Fermi Gamma-ray Space Telescope have discovered the first gamma-ray pulsar in a galaxy other than our own. (astronomynow.com)
  • The Fermi Gamma-ray Space Telescope , launched in 2008, discovered pulsars that emitted only gamma rays. (britannica.com)
  • Every three hours, NASA's Fermi Gamma-ray Space Telescope scans the entire sky and deepens its portrait of the high-energy universe. (nasa.gov)
  • The data was accumulated by NASA's Fermi Gamma-ray Space Telescope for five years. (eso.org)
  • WASHINGTON -- Astronomers using NASA's Swift satellite and Fermi Gamma-ray Space Telescope are seeing frequent blasts from a stellar remnant 30,000 light-years away. (spaceflightnow.com)
  • Terrestrial gamma-ray flashes were first discovered in 1994 by BATSE , or Burst and Transient Source Experiment, on the Compton Gamma Ray Observatory , a NASA spacecraft. (wikipedia.org)
  • This database table comprises the gamma-ray bursts detected by the BATSE instrument on the Compton Gamma-Ray Observatory (CGRO). (nasa.gov)
  • Artist's image of the Compton Gamma Ray Observatory. (newworldencyclopedia.org)
  • The Compton Gamma-Ray Observatory (CGRO) was designed to take advantage of the major advances in detector technology during the 1980s, and it was launched in 1991. (newworldencyclopedia.org)
  • In the early 1990s NASA's Compton Gamma Ray Observatory, in orbit around the Earth, scanned the entire sky to produce this picture. (nasa.gov)
  • The Compton Gamma Ray Observatory , launched in 1991, mapped thousands of celestial gamma-ray sources. (britannica.com)
  • NASA's Compton Gamma Ray Observatory (CGRO) first discovered TGFs in the 1990s. (sciencedaily.com)
  • It is presumed that TGF photons are emitted by electrons traveling at speeds very close to the speed of light that collide with the nuclei of atoms in the air and release their energy in the form of gamma rays ( bremsstrahlung [7] ). (wikipedia.org)
  • Long before scientists could detect gamma rays from cosmic sources, they had suspected that the universe may be producing photons in this energy range. (newworldencyclopedia.org)
  • In 1961, the Explorer 11 satellite carried the first space-based gamma-ray telescope, which detected less than 100 cosmic gamma-ray photons. (newworldencyclopedia.org)
  • [1] As these photons seemed to come from all directions, they suggested the presence of a uniform "gamma-ray background" in the universe. (newworldencyclopedia.org)
  • These gamma-ray photons are more than 40 million times more energetic than visible light photons and are blocked from the Earth's surface by the atmosphere. (nasa.gov)
  • This process, called inverse-Compton scattering, boosts the normally low-energy CMB photons to the extremely high energies of gamma rays. (astronomy.com)
  • Gamma rays consist of high energy photons with energies above about 100 keV . (wikidoc.org)
  • X-ray photons are generated by energetic electron processes, gamma rays by transitions within atomic nuclei. (wikidoc.org)
  • The photoelectric effect is the dominant energy transfer mechanism for x-ray and gamma ray photons with energies below 50 keV (thousand electron volts ), but it is much less important at higher energies. (wikidoc.org)
  • Gamma-rays from cosmological gamma-ray sources, primarily blazars but also gamma-ray bursts, interact with the extragalactic background light (EBL) photons, and are absorbed. (cern.ch)
  • One of them zapped out gamma rays with energies of up to a teraelectronvolt - equivalent to about 500 billion times the energy of photons our eyes detect! (syfy.com)
  • HESS doesn't see gamma rays directly, but is sensitive to the glow in our own atmosphere when these super-high-energy photons slam into the air, moving faster than light in that medium (which is slower than light speed in a vacuum, so no physical laws are broken here). (syfy.com)
  • It found gamma rays from GRC 180720B that were 440 billion electron Volts (typical visible light photons that we see range from 2-3 eV, so there are extremely energetic photons), the highest ever seen. (syfy.com)
  • Most radionuclides release high-energy photons as gamma rays but PET uses radionuclides that release particles called positrons. (msdmanuals.com)
  • For gamma-ray bursts of cosmic origin, see Gamma-ray burst . (wikipedia.org)
  • A terrestrial gamma-ray flash ( TGF ), also known as dark lightning , is a burst of gamma rays produced in Earth's atmosphere. (wikipedia.org)
  • Located in the constellation of Leo, the 30-second burst, designated GRB 030329, outshone the entire Universe in gamma rays. (bbc.co.uk)
  • At the moment, researchers cannot yet determine the timing of the gamma burst relative to the supernova (whether one preceded the other or whether both began at the same time), but the same event - a star explosion - was certainly the trigger for both, they say. (bbc.co.uk)
  • All gamma-ray bursts may have associated supernovae that are too faint to observe," says Matheson, who believes that because the burst was both close and bright, the supernova was detectable. (bbc.co.uk)
  • The BATSE Current Gamma-Ray Burst Catalog, the BATSE GRB Team, http://gammaray.msfc.nasa.gov/batse/grb/catalog/current/ The Fourth BATSE Gamma-Ray Burst Catalog, C. A. Meegan et al. (nasa.gov)
  • 1997). The Third BATSE BATSE Gamma-Ray Burst Catalog, C. A. Meegan et al. (nasa.gov)
  • The BFITS data files - containing burst and background spectral data as a function of time - and the detector response matrices (DRM) - modeling the instrument response to account for scattering and other effects - are extremely useful for gamma-ray burst analysis. (nasa.gov)
  • This database table contains values for T90 and T50, quantities related to burst duration, for 1234 gamma-ray bursts that triggered the BATSE LAD detectors between April 1991 and 29 August 1996. (nasa.gov)
  • What is a Gamma Ray Burst? (aavso.org)
  • A gamma-ray burst (GRB) is a brief flash of gamma rays coming from an astrophysical source at great distances from us, often from hundreds of millions of light years away. (aavso.org)
  • On 2017 August 17, the gravitational-wave event GW170817 was observed by the Advanced LIGO and Virgo detectors, and the gamma-ray burst (GRB) GRB 170817A was observed independently by the Fermi Gamma-ray Burst Monitor, and the Anticoincidence Shield for the Spectrometer for the International Gamma-Ray Astrophysics Laboratory. (mendeley.com)
  • Finally, we predict a joint detection rate for the Fermi Gamma-ray Burst Monitor and the Advanced LIGO and Virgo detectors of 0.1--1.4 per year during the 2018-2019 observing run and 0.3--1.7 per year at design sensitivity. (mendeley.com)
  • Less than two seconds after the Laser Interferometer Gravitational-wave Observatory (LIGO) experiment was triggered by the passage of gravitational waves, marked as T 0 , the Anti-Coincidence Shield on INTEGRAL's SPI spectrometer, recorded a burst of gamma rays for 0.1 sec. (esa.int)
  • The observations indicated that the gravitational waves and the gamma-ray burst originate from the same cosmic event: the collision of two neutron stars. (esa.int)
  • The researchers noted a startlingly low level of polarisation in the gamma-ray burst in the moments straight after the star's collapse, indicating the star's magnetic field had been destroyed during the explosion. (newswise.com)
  • The brightest gamma-ray burst ever detected yet, codenamed GRB 221009A, has a strange structure that astronomers have never seen before. (theregister.com)
  • The burst was later determined to be the most energetic flare observed by gamma-ray observatories, and is over a magnitude brighter than previous record breakers. (theregister.com)
  • It is 70 times brighter than any other gamma-ray burst discovered in over 50 years of observation," Brendan O'Connor, an astronomer at the University of Maryland, told The Register . (theregister.com)
  • The ability of Fermi's gamma-ray burst monitor to resolve the fine structure within these events will help us better understand how magnetars unleash their energy," said Chryssa Kouveliotou, an astrophysicist at NASA's Marshall Space Flight Center in Huntsville, Ala. The object has triggered the instrument more than 95 times since Jan. 22. (spaceflightnow.com)
  • The detection of a gamma ray burst by the MAGIC telescopes allows to study whether the speed of light in vacuum is a constant of nature. (ifae.es)
  • Artwork depicting a gamma-ray burst with a beam of material racing away. (syfy.com)
  • That is the gamma-ray burst: An intensely high-energy pair of beams - calling them death rays is not really an exaggeration, as it's nearly impossible to exaggerate anything about GRBs - that scream outward into space. (syfy.com)
  • Natural sources of gamma rays originating on Earth are mostly a result of radioactive decay and secondary radiation from atmospheric interactions with cosmic ray particles. (wikipedia.org)
  • Gamma rays were first thought to be particles with mass, like alpha and beta rays. (wikipedia.org)
  • Natural sources of gamma rays on Earth include gamma decay from naturally occurring radioisotopes such as potassium-40, and also as a secondary radiation from various atmospheric interactions with cosmic ray particles. (wikipedia.org)
  • The Higgs boson, for example, can decay into many different types of particles, including gamma rays. (symmetrymagazine.org)
  • These phenomena included supernova explosions, interactions of cosmic rays (very energetic charged particles in space) with interstellar gas, and interactions of energetic electrons with magnetic fields . (newworldencyclopedia.org)
  • The NORDBALL array with neutron and charged particle detectors was employed for the detection of gamma rays and light evaporated particles. (lu.se)
  • 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)
  • The types that are normally important to your health are alpha particles, beta particles, x rays, and gamma rays. (cdc.gov)
  • 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)
  • For example, beta particles, gamma rays, and x-rays have a RWF of 1.0, making their effects on tissue largely equivalent. (medscape.com)
  • Alpha particles, however, have a RWF of 20, which indicates a biologic effect that is potentially 20 times greater than that of beta particles, gamma rays, or x-rays. (medscape.com)
  • However, there are other rare natural sources, such as terrestrial gamma-ray flashes, which produce gamma rays from electron action upon the nucleus. (wikipedia.org)
  • Scientists have also detected energetic positrons and electrons produced by terrestrial gamma-ray flashes. (wikipedia.org)
  • A new nano satellite mission, called 'Firefly,' sponsored by the National Science Foundation (NSF) and led by NASA's Goddard Space Flight Center in Greenbelt, Md. will explore the relationship between lightning and these sudden bursts, called Terrestrial Gamma Ray Flashes (TGFs). (sciencedaily.com)
  • Identifying the source of terrestrial gamma ray flashes would be a great step toward fully understanding the physics behind lightning and its effect on the Earth's atmosphere. (sciencedaily.com)
  • Gamma rays are the most energetic type of light, packing a punch strong enough to pierce through metal or concrete barriers. (symmetrymagazine.org)
  • More energetic than X-rays, they are born in the chaos of exploding stars, the annihilation of electrons and the decay of radioactive atoms. (symmetrymagazine.org)
  • Gamma rays are a kind of light (like visible light, microwaves, or X-rays) that is very energetic, and whatever produces gamma rays must therefore contain (and unleash) a large amount of energy in a very short amount of time. (aavso.org)
  • Gamma rays are the most energetic form of electromagnetic radiation and are produced by phenomena such as explosions and high-speed collisions. (newworldencyclopedia.org)
  • In the 1990s, observatories in space detected bursts of gamma rays coming from Earth that eventually were traced to thunderclouds. (symmetrymagazine.org)
  • Detectors aboard the Vela satellite series, designed to detect flashes of gamma rays from nuclear bomb blasts, began to record bursts of gamma rays not from the vicinity of the Earth but from deep space. (newworldencyclopedia.org)
  • Swift's X-Ray Telescope captured an apparent expanding halo around the flaring neutron star SGR J1550-5418. (spaceflightnow.com)
  • Rutherford and his co-worker Edward Andrade measured the wavelengths of gamma rays from radium, and found they were similar to X-rays, but with shorter wavelengths and thus, higher frequency. (wikipedia.org)
  • They confirmed the earlier findings of the gamma-ray background, produced the first detailed map of the sky at gamma-ray wavelengths, and detected a number of point sources. (newworldencyclopedia.org)
  • During its High Energy Astronomy Observatory program in 1977, NASA announced plans to build a "great observatory" for gamma-ray astronomy. (newworldencyclopedia.org)
  • But "SS 433 is right in our neighborhood," said Jordan Goodman of the University of Maryland, who also serves as U.S. lead investigator and spokesperson for the High-Altitude Water Cherenkov Gamma-Ray Observatory (HAWC) collaboration, in a press release . (astronomy.com)
  • They were alerted to the star's collapse after its gamma-ray flash (named GRB 190114C) was detected by NASA's space-borne Neil Gehrels Swift Observatory. (newswise.com)
  • Take away all the known sources of gamma rays in the universe, and you might be left with the above picture - something a new NASA probe could soon see. (newscientist.com)
  • He covers in detail his discovery of the positive electron, his pair production work with gamma rays, his expedition to Pike's Peak with Neddermeyer and their discovery of the mesotron. (aip.org)
  • Gamma rays (denoted as γ ) are a form of electromagnetic radiation or light emission of frequencies produced by sub-atomic particle interactions, such as electron-positron annihilation or radioactive decay . (wikidoc.org)
  • This describes the case in which a gamma photon interacts with and transfers its energy to an atomic electron, ejecting that electron from the atom. (wikidoc.org)
  • The kinetic energy of the resulting photoelectron is equal to the energy of the incident gamma photon minus the binding energy of the electron. (wikidoc.org)
  • This is an interaction in which an incident gamma photon loses enough energy to an atomic electron to cause its ejection, with the remainder of the original photon's energy being emitted as a new, lower energy gamma photon with an emission direction different from that of the incident gamma photon. (wikidoc.org)
  • A gamma ray, also known as gamma radiation (symbol γ or γ {\displaystyle \gamma } ), is a penetrating form of electromagnetic radiation arising from the radioactive decay of atomic nuclei. (wikipedia.org)
  • Gamma rays and X-rays are both electromagnetic radiation, and since they overlap in the electromagnetic spectrum, the terminology varies between scientific disciplines. (wikipedia.org)
  • In 1914, gamma rays were observed to be reflected from crystal surfaces, proving that they were electromagnetic radiation. (wikipedia.org)
  • Gamma rays are generally characterized as electromagnetic radiation having the highest frequency and energy, and also the shortest wavelength (below about 10 picometer ), within the electromagnetic spectrum . (wikidoc.org)
  • X rays and gamma rays are types of electromagnetic radiation. (cdc.gov)
  • Kouveliotou discusses her cultural introduction to the United States and her work at the Goddard Space Flight Center where she studied gamma ray bursts for her graduate thesis. (aip.org)
  • In astrophysics, gamma rays are conventionally defined as having photon energies above 100 keV and are the subject of gamma ray astronomy, while radiation below 100 keV is classified as X-rays and is the subject of X-ray astronomy. (wikipedia.org)
  • She recounts her work in extraterrestrial physics at the Max Planck Institute and she describes the origins of gamma ray astronomy. (aip.org)
  • Kouveliotou explains her academic work in Greece after her graduate studies and her research at the Institute for Space Physics, Astronomy and Education where she worked with data from the BATSE project and continued research on gamma ray bursts. (aip.org)
  • Gamma-ray astronomy is a branch of astronomy that deals with the detection and study of gamma rays in the cosmos. (newworldencyclopedia.org)
  • Thus, gamma-ray astronomy provides the opportunity for scientists to study objects and phenomena in the universe that are associated with extremely high energies. (newworldencyclopedia.org)
  • For this reason, the development of gamma-ray astronomy was delayed until it became possible to place detectors above most (if not all) of the atmosphere, using balloons or spacecraft. (newworldencyclopedia.org)
  • In the late 1960s and early 1970s, gamma-ray astronomy received an unexpected boost from a constellation of defense satellites. (newworldencyclopedia.org)
  • The field of gamma-ray astronomy took great leaps forward with the SAS-2 (1972) and the COS-B (1975-1982) satellites. (newworldencyclopedia.org)
  • This consists of many beams of gamma rays focused on the cells that need to be destroyed. (symmetrymagazine.org)
  • Assuming a featureless emission geometry of 1 steradian corresponding to an alignment of the radio and gamma-ray beams, our model predicts that EGRET should have seen 17 radio loud and 5 radio quiet, gamma-ray pulsars. (iac.es)
  • Space telescopes are useful for the study of cosmic gamma rays, most of which are absorbed by the Earth's atmosphere. (newworldencyclopedia.org)
  • Most of the gamma rays coming from space are absorbed by the Earth's atmosphere. (newworldencyclopedia.org)
  • Earth's atmosphere blocks most gamma rays, so most gamma-ray telescopes are carried on satellites and balloons . (britannica.com)
  • However, some ground-based telescopes can observe the Cherenkov radiation produced when a gamma ray strikes Earth's upper atmosphere. (britannica.com)
  • In 2004, a giant flare from another soft-gamma-ray repeater was so intense it measurably affected Earth's upper atmosphere from 50,000 light-years away. (spaceflightnow.com)
  • Scientists may have solved one of astronomy's major puzzles: the origin of powerful gamma-ray bursts. (bbc.co.uk)
  • In addition, they have detected immensely powerful gamma-ray bursts (GRBs) that appear to come from sources in deep space. (newworldencyclopedia.org)
  • Paul Villard, a French chemist and physicist, discovered gamma radiation in 1900 while studying radiation emitted by radium. (wikipedia.org)
  • in 1900 he had already named two less penetrating types of decay radiation (discovered by Henri Becquerel) alpha rays and beta rays in ascending order of penetrating power. (wikipedia.org)
  • Gamma rays are ionizing radiation and are thus hazardous to life. (wikipedia.org)
  • Unlike alpha and beta rays, they easily pass through the body and thus pose a formidable radiation protection challenge, requiring shielding made from dense materials such as lead or concrete. (wikipedia.org)
  • On Earth, the magnetosphere protects life from most types of lethal cosmic radiation other than gamma rays. (wikipedia.org)
  • Villard knew that his described radiation was more powerful than previously described types of rays from radium, which included beta rays, first noted as "radioactivity" by Henri Becquerel in 1896, and alpha rays, discovered as a less penetrating form of radiation by Rutherford, in 1899. (wikipedia.org)
  • Later, in 1903, Villard's radiation was recognized as being of a type fundamentally different from previously named rays by Ernest Rutherford, who named Villard's rays "gamma rays" by analogy with the beta and alpha rays that Rutherford had differentiated in 1899. (wikipedia.org)
  • the objects emit their radiation in a narrow direction with radio, but a wider stripe with gamma rays. (universetoday.com)
  • To monitor nuclear tests in the 1960s, the United States launched gamma radiation detectors on satellites. (symmetrymagazine.org)
  • Astronomers have found that the universe contains a uniform background of gamma radiation, which has been attributed to the interaction of cosmic rays with interstellar gas. (newworldencyclopedia.org)
  • In passing through matter, gamma radiation ionizes via three main processes: the photoelectric effect , Compton scattering , and pair production . (wikidoc.org)
  • Gamma rays are often produced alongside other forms of radiation such as alpha or beta . (wikidoc.org)
  • Together, they came up with an affordable, yet very sensitive, gamma-ray scintillation probe for their customized Civil Defense V-700 radiation survey meter. (hackaday.com)
  • Radiation Protection Guidance for Diagnostic and Interventional X-Ray Procedures: Federal Guidance Report No. 14 is now available for public comment. (cdc.gov)
  • The use of ionizing radiation in medicine began with the discovery of x-rays by Roentgen in 1895. (medscape.com)
  • Ionizing radiation can exist in 2 forms: as an electromagnetic wave, such as an x-ray or gamma ray, or as a particle, in the form of an alpha or beta particle, neutron, or proton. (medscape.com)
  • The latest breakthrough began on 29 March when the High-Energy Transient Explorer satellite (Hete) detected one of the brightest and closest gamma-ray bursts ever seen. (bbc.co.uk)
  • Typically, the Vela pulsar, which lies only 1,000 light-years away, is the sky's brightest persistent source of gamma rays. (nasa.gov)
  • The halo formed as X-rays from the brightest flares scattered off of intervening dust clouds. (spaceflightnow.com)
  • X-rays from the brightest bursts scatter off of dust clouds between us and the star," Halpern said. (spaceflightnow.com)
  • Significant gamma-ray emission from our galaxy was first detected in 1967 by the gamma-ray detector aboard the OSO-3 satellite. (newworldencyclopedia.org)
  • Instead, gamma rays are detected by the optical flashes they produce when interacting with the material in a specially designed instrument such as a scintillation detector . (britannica.com)
  • The system consists of two parts: a compact DD neutron generator with a flux of up to 3 * 109 neutrons/ sec for irradiation, and a 100% HPGe detector system for Mn gamma ray detection. (cdc.gov)
  • The Mn characteristic y-rays were collected by the high efficiency HPGe detector system. (cdc.gov)
  • Computed Tomography (CT) In computed tomography (CT), which used to be called computed axial tomography (CAT), an x-ray source and x-ray detector rotate around a person. (msdmanuals.com)
  • In modern scanners, the x-ray detector usually. (msdmanuals.com)
  • Designed to look outward at cosmic sources of gamma rays, CGRO also caught rare but tantalizing glimpses of gamma rays coming from Earth. (sciencedaily.com)
  • It is applicable to nuclides emitting gamma-rays with energies greater than 20 keV. (astm.org)
  • When HESS sees them it can figure out where the original gamma rays came from, and what their energies were. (syfy.com)
  • So if they exist, a gamma ray telescope should be able to observe them. (universetoday.com)
  • gamma-ray telescope , instrument designed to detect and resolve gamma rays from sources outside Earth 's atmosphere . (britannica.com)
  • Since gamma rays have so much energy, they pass right through the mirror of a standard optical telescope . (britannica.com)
  • The first gamma-ray telescope was carried on board the American satellite Explorer 11 in 1961. (britannica.com)
  • These all-sky images, which record the numbers of high-energy gamma-rays captured by Fermi's Large Area Telescope on Dec. 3 and Nov. 18, clearly show the change. (nasa.gov)
  • These relatively steady sources are in addition to the numerous transient events Fermi detects, such as gamma-ray bursts in the distant universe and flares from the sun.Earlier this year, the Fermi team released its second catalog of sources detected by the satellite's Large Area Telescope (LAT), producing an inventory of 1,873 objects shining with the highest-energy form of light. (nasa.gov)
  • Using data from Swift's X-ray telescope, Jules Halpern at Columbia University captured the first "light echoes" ever seen from a soft-gamma-ray repeater. (spaceflightnow.com)
  • The energy spectrum of gamma rays can be used to identify the decaying radionuclides using gamma spectroscopy. (wikipedia.org)
  • Astronomers eventually realized these explosions were coming from deep space-not the Soviet Union-and named them gamma-ray bursts, or GRBs. (symmetrymagazine.org)
  • Today we know GRBs come in two types: the explosions of extremely massive stars, which pump out gamma rays as they die, and collisions between highly dense relics of stars called neutron stars and something else, probably another neutron star or a black hole. (symmetrymagazine.org)
  • That's good for our health, but not so great for those who want to study GRBs and other sources of gamma rays. (symmetrymagazine.org)
  • These extremely bright gamma-ray bursts (GRBs) are the most powerful explosions in the universe, and when a jet points towards Earth, the afterglow can be detected from ground and space-borne telescopes. (newswise.com)
  • This states that repeated violent collisions between material blasted out during the explosion and material surrounding the dying star produce the gamma-ray flash and the subsequent fading afterglow - the dying embers of the expanding fireball. (newswise.com)
  • The combination of extreme gamma-ray brightness and never-ending afterglow is fatal for most models because it creates an energy crisis," Eleonora Troja, lead author of the paper and an associate professor at the University of Rome, explained to us. (theregister.com)
  • When an unstable uranium nucleus splits in the process of nuclear fission, it releases a lot of gamma rays in the process. (symmetrymagazine.org)
  • I describe how combining results of gamma-ray absorption measurements with the Fermi-LAT with galaxy survey results can constrain these quantities. (cern.ch)
  • Within seconds NASA's orbiting Fermi and Swift gamma-ray satellites detected it, and sent out an automated alert to other telescopes to look for it. (syfy.com)
  • A gamma decay was then understood to usually emit a gamma photon. (wikipedia.org)
  • These gamma bells may not produce the kind of tintinnabulation that we're accustomed to, but the gamma rays they emit could be music to alien ears. (ieee.org)
  • French chemist Paul Villard first identified gamma rays in 1900 from the element radium, which had been isolated by Marie and Pierre Curie just two years before. (symmetrymagazine.org)
  • A diffuse gamma-ray glow from the plane of our Milky Way Galaxy is clearly seen across the middle. (nasa.gov)
  • Now, an international collaboration of researchers has announced in the journal Nature that they've detected the first gamma-ray signal from the ends of the two jets spewing out of a Milky Way microquasar. (astronomy.com)
  • SS 433 is one of only about a dozen identified microquasars in the Milky way, and one of only a few of those from which gamma rays -an extremely high-energy form of light - have been seen. (astronomy.com)
  • Researchers from the MAGIC collaboration, have detected very high-energy gamma rays from a recurrent nova in the Milky Way. (ifae.es)
  • Due to this accidental bombardment of gamma rays Bruce became a giant green (at first grey) creature known as The Incredible Hulk whenever he is angered. (cdc.gov)
  • 1.1 This test method covers the measurement of gamma-ray emitting radionuclides in water by means of gamma-ray spectrometry. (astm.org)
  • In addition to the quantitative measurement of gamma radioactivity, gamma spectrometry can be used for the identification of specific gamma emitters in a mixture of radionuclides. (astm.org)
  • Artist's conception of gamma-ray flash and related phenomena. (wikipedia.org)
  • Energy plot of a typical TGF event, with artist's conception of a gamma-ray flash superimposed. (wikipedia.org)
  • If neutralinos exist, they should interact with each other to produce gamma rays. (newscientist.com)
  • Notable artificial sources of gamma rays include fission, such as that which occurs in nuclear reactors, and high energy physics experiments, such as neutral pion decay and nuclear fusion. (wikipedia.org)
  • In some fields of physics, they are distinguished by their origin: Gamma rays are created by nuclear decay while X-rays originate outside the nucleus. (wikipedia.org)
  • In the 1960s the Vela defense satellites designed to detect gamma rays from clandestine nuclear testing serendipitously discovered enigmatic gamma-ray bursts coming from deep space . (britannica.com)
  • BLIND GUARDIAN, GAMMA RAY, RAGE) in early May to begin recording their as-yet-untitled fourth full-length album for a late 2002 release through Nuclear Blast Records. (blabbermouth.net)
  • Our proposed method uses a CD plastic capsule filled with 50/50 HT gas and diagnosed using gas Cherenkov detection (GCD) to temporally resolve both the HT "clean" and DT "mix" gamma ray burn histories. (osti.gov)
  • AAVSO Alert Notice 611 reports on a major gamma-ray flare in the blazar 3C 279 (Virgo). (aavso.org)
  • To study gamma rays, astronomers build telescopes in space. (symmetrymagazine.org)
  • To see gamma rays before they reach the atmosphere, astronomers have to build telescopes in space. (symmetrymagazine.org)
  • In the 1970s Earth-orbiting observatories found a number of gamma-ray point sources, including an exceptionally strong one dubbed Geminga that was later identified as a nearby pulsar . (britannica.com)
  • It consists of the shortest wavelength electromagnetic waves, typically shorter than those of X-rays. (wikipedia.org)
  • Because this "star" would be at the Planck density, it would radiate at a specific wavelength of gamma rays. (universetoday.com)
  • Hard X-rays overlap the range of "long"-wavelength (lower energy) gamma rays. (wikidoc.org)
  • Gamma rays from radioactive decay are in the energy range from a few kiloelectronvolts (keV) to approximately 8 megaelectronvolts (MeV), corresponding to the typical energy levels in nuclei with reasonably long lifetimes. (wikipedia.org)
  • The first gamma ray source to be discovered was the radioactive decay process called gamma decay. (wikipedia.org)
  • Today we know alpha rays are the same thing as helium nuclei (two protons and two neutrons), beta rays are either electrons or positrons (their antimatter versions), and gamma rays are a kind of light. (symmetrymagazine.org)
  • That static electricity also acts like a giant particle accelerator, creating pairs of electrons and positrons, which then annihilate into gamma rays. (symmetrymagazine.org)
  • These two sites are the ends of the microquasar's jets, where the researchers believe that emission from electrons interacting with light from the cosmic microwave background (CMB), which permeates the universe, is responsible for the gamma rays. (astronomy.com)
  • A new generation of gamma-ray detectors, and subthreshold searches in existing detectors, will be essential to detect similar short bursts at greater distances. (mendeley.com)
  • Gamma ray bursts are the most powerful explosions in the Universe, releasing more energy in a few seconds than our Sun will put out in its lifetime. (universetoday.com)
  • Thus the study of gamma ray bursts is a study of some of the most violent events in the universe. (aavso.org)
  • Gamma-ray bursts trace the deaths of massive stars and can allow us to trace the star formation history of the universe and also specifically the star formation in the galaxies in which they form. (theregister.com)
  • The first true astrophysical gamma-ray sources detected were solar flares, which revealed the strong 2.223 MeV line predicted by Morrison. (newworldencyclopedia.org)
  • This allows one to use gamma-ray absorption to constrain the EBL, which depends strongly on a number of quantities that are interesting from an astrophysical and cosmological point of view. (cern.ch)
  • Material does not simply catapult from an exploding star, it accelerates to ultra-high speeds along the narrow beam of the gamma-ray jet, leaving astrophysics puzzled over the power source driving these extraordinary explosions. (newswise.com)
  • The exponential absorption holds only for a narrow beam of gamma rays. (wikidoc.org)
  • If a wide beam of gamma rays passes through a thick slab of concrete, the scattering from the sides reduces the absorption. (wikidoc.org)
  • During the past two years, astronomers have identified pulsing radio and X-ray signals from it. (spaceflightnow.com)
  • Because of the recent outbursts, astronomers will classify the object as a soft-gamma-ray repeater -- only the sixth known. (spaceflightnow.com)
  • Gamma-ray pulsars in the Milky Way's plane, found by volunteers using Einstein@Home. (universetoday.com)
  • Although the discovery is exciting to the eight volunteers because they are the first to find these gamma-ray pulsars as part of a volunteer computing project, the pulsars also have some interesting scientific features. (universetoday.com)
  • We simulate the characteristics of the Galactic population of radio and gamma-ray pulsars using Monte Carlo techniques. (iac.es)
  • Using the features of recent polar cap acceleration models invoking space-charge-limited flow, a pulsar death region further attenuates the population of radio-loud pulsars, and gamma-ray luminosities are assigned. (iac.es)
  • GLAST, on the other hand, is expected to observe 132 radio loud and 212 radio quiet, gamma-ray pulsars of which 21 are expected to be identified as pulsed sources. (iac.es)
  • There should no longer be doubt in anybody's mind that gamma-ray bursts and supernovae are connected," says Thomas Matheson, of the Harvard-Smithsonian Centre for Astrophysics, US, a member of the team that made the discovery. (bbc.co.uk)
  • Very-high-energy gamma rays in the 100-1000 teraelectronvolt (TeV) range have been observed from sources such as the Cygnus X-3 microquasar. (wikipedia.org)
  • After noting the absence of any cosmic ray work during the war years, he mentions the postwar development of cosmic ray work into high energy physics. (aip.org)
  • This is a newfound way to produce high-energy gamma rays in microquasars. (astronomy.com)
  • The high-energy fireworks arise from a rare type of neutron star known as a soft-gamma-ray repeater. (spaceflightnow.com)
  • Due to their high energy content, gamma rays can cause serious damage when absorbed by living cells. (wikidoc.org)
  • These first gamma-ray line observations were from the spacecrafts OSO-3, OSO-7, and the Solar Maximum Mission, the last of which was launched in 1980. (newworldencyclopedia.org)
  • The satellite carried four major instruments which have greatly improved the spatial and temporal resolution of gamma-ray observations. (newworldencyclopedia.org)
  • More than half of these sources are active galaxies whose supermassive black hole centers are causing the gamma-ray emissions. (nasa.gov)
  • Brighter colours indicate brighter gamma-ray sources. (eso.org)
  • David] says that since the probe is very portable and has a high level of sensitivity, it is an ideal candidate for radioactive mineral surveying and scouting miscellaneous gamma-ray sources. (hackaday.com)
  • Are gamma-ray bursts powered by a star's collapsing magnetic fields? (newswise.com)