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.
Actinium. A trivalent radioactive element and the prototypical member of the actinide family. It has the atomic symbol Ac, atomic number 89, and atomic weight 227.0278. Its principal isotope is 227 and decays primarily by beta-emission.
Polonium. A radioactive element that is a member of the chalcogen family. It has the atomic symbol Po, atomic number 84, and the atomic weight of the isotope with the longest half-life (209Po) is 208.98. It decays by alpha-emission.
A naturally radioactive element with atomic symbol Rn, atomic number 86, and atomic weight 222. It is a member of the noble gas family found in soil, and is released during the decay of radium.
Radium. A radioactive element of the alkaline earth series of metals. It has the atomic symbol Ra, atomic number 88, and atomic weight 226. Radium is the product of the disintegration of uranium and is present in pitchblende and all ores containing uranium. It is used clinically as a source of beta and gamma-rays in radiotherapy, particularly BRACHYTHERAPY.
Substances that comprise all matter. Each element is made up of atoms that are identical in number of electrons and protons and in nuclear charge, but may differ in mass or number of neutrons.
Separation systems containing a relatively long-lived parent radionuclide which produces a short-lived daughter in its decay scheme. The daughter can be periodically extracted (milked) by means of an appropriate eluting agent.
Neon. A noble gas with the atomic symbol Ne, atomic number 10, and atomic weight 20.18. It is found in the earth's crust and atmosphere as an inert, odorless gas and is used in vacuum tubes and incandescent lamps.
Uranium. A radioactive element of the actinide series of metals. It has an atomic symbol U, atomic number 92, and atomic weight 238.03. U-235 is used as the fissionable fuel in nuclear weapons and as fuel in nuclear power reactors.
Relating to the size of solids.
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).
The relationship between the dose of administered radiation and the response of the organism or tissue to the radiation.
The result of a positive or negative response (to drugs, for example) in one cell being passed onto other cells via the GAP JUNCTIONS or the intracellular milieu.
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)
The measurement of radiation by photography, as in x-ray film and film badge, by Geiger-Mueller tube, and by SCINTILLATION COUNTING.
A technique for the treatment of neoplasms, especially gliomas and melanomas in which boron-10, an isotope, is introduced into the target cells followed by irradiation with thermal neutrons.
'Mining' in medical terminology is not a commonly used term, but it can refer to the process of extracting or excavating minerals or other resources from the earth, which can have health impacts such as respiratory diseases and hearing loss among workers in the mining industry.
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).
Connective tissue cells which secrete an extracellular matrix rich in collagen and other macromolecules.
Plasma glycoprotein member of the serpin superfamily which inhibits TRYPSIN; NEUTROPHIL ELASTASE; and other PROTEOLYTIC ENZYMES.

Loss of normal G1 checkpoint control is an early step in carcinogenesis, independent of p53 status. (1/190)

Recent studies have described a diminished radiation-induced G1 arrest in some wild-type (wt) p53 human tumor cell lines compared to normal human fibroblasts. However, the significance of this finding was unclear, particularly because tumor cell lines may have accumulated additional genetic changes after long periods in culture. Because malignant transformation of individual cells is thought to be an early step in carcinogenesis, we have used a model system of normal and transformed mouse fibroblast 10T1/2 cell clones to examine whether loss of G1 checkpoint control may be an early event in tumor development and to study the relationships between G1 arrest, radiosensitivity, and genetic alterations. Twelve transformed clones were established from type III foci induced by irradiation of normal 10T1/2 cells and were compared with six clones derived from wt 10T1/2 cells. Three of the transformed clones expressed mutant p53; two of these had the same point mutation at codon 132 (exon 5), and one had a point mutation at codon 135. The remaining transformed and normal clones had wt p53 status. The radiosensitivity of transformed clones, as measured by a clonogenic assay, was similar to that of normal clones; the three clones with mutant p53 did not differ from the others. There was no relationship between G1 arrest and radiosensitivity. Normal 10T1/2 cell clones showed a transient G1 arrest lasting approximately 9 h after 6 Gy of irradiation. This G1 arrest was either absent or markedly reduced in all of the transformed clones, regardless of p53 status. These results suggest that diminished G1 checkpoint control is an early event in the process of carcinogenesis that is associated with the malignant transformation of individual cells and is independent of p53 status.  (+info)

Targeted cytoplasmic irradiation with alpha particles induces mutations in mammalian cells. (2/190)

Ever since x-rays were shown to induce mutation in Drosophila more than 70 years ago, prevailing dogma considered the genotoxic effects of ionizing radiation, such as mutations and carcinogenesis, as being due mostly to direct damage to the nucleus. Although there was indication that alpha particle traversal through cellular cytoplasm was innocuous, the full impact remained unknown. The availability of the microbeam at the Radiological Research Accelerator Facility of Columbia University made it possible to target and irradiate the cytoplasm of individual cells in a highly localized spatial region. By using dual fluorochrome dyes (Hoechst and Nile Red) to locate nucleus and cellular cytoplasm, respectively, thereby avoiding inadvertent traversal of nuclei, we show here that cytoplasmic irradiation is mutagenic at the CD59 (S1) locus of human-hamster hybrid (AL) cells, while inflicting minimal cytotoxicity. The principal class of mutations induced are similar to those of spontaneous origin and are entirely different from those of nuclear irradiation. Furthermore, experiments with radical scavenger and inhibitor of intracellular glutathione indicated that the mutagenicity of cytoplasmic irradiation depends on generation of reactive oxygen species. These findings suggest that cytoplasm is an important target for genotoxic effects of ionizing radiation, particularly radon, the second leading cause of lung cancer in the United States. In addition, cytoplasmic traversal by alpha particles may be more dangerous than nuclear traversal, because the mutagenicity is accomplished by little or no killing of the target cells.  (+info)

Preparation of alpha-emitting 213Bi-labeled antibody constructs for clinical use. (3/190)

Preclinical evaluation of alpha particle-emitting 213Bi-labeled antibody constructs have demonstrated the specificity and potency of these agents in a variety of cancer systems. The transition of a 213Bi-radiolabeled antibody from a preclinical construct to a clinical drug represented a difficult task that involved development of reliable and validated methods to provide multiple MBq quantities of a pure, immunoreactive agent that met pharmaceutical standards to treat patients. METHODS: The methods used for the preparation of (213Bi)CHX-A-diethylenetriamine pentaacetic acid (DTPA)-HuM195, an alpha particle-emitting anti-CD33 antibody construct for therapy of myeloid leukemias, is used as a specific example. This article describes methods for reagent purification, drug labeling, radioprotection and chromatographic purification. Quality of the drug is evaluated using radiochemical incorporation and purity assays with instant thin-layer chromatography (ITLC) and high-performance liquid chromatography (HPLC), determination of cell-based antibody total immunereactivity, small animal safety, pyrogen level, sterility and radionuclidic purity. RESULTS: Sixty-seven doses were prepared. Individual doses ranged from 148 to 814 MBq. Specific activities ranged from 329 to 766 MBq/mg. The radiolabeling efficiency (median +/- SD) of CHX-A-DTPA-HuM195 with 213Bi was 81% +/- 9% (n = 67) after 9 min. The construct was purified by size-exclusion chromatography and was found to be 99% +/- 2% pure (n = 67) by either ITLC or HPLC methods. The immunoreactivity of (213Bi)CHX-A-DTPA-HuM195 was 89% +/- 9% (n = 44) and was independent of the specific activity. The formulated pharmaceutical was found to contain < or =4 +/- 1 EU/mL pyrogens (n = 66); all samples examined were sterile. An 225Ac radionuclidic impurity was present at a level of 0.04 +/- 0.03 x 10(-6)/mL (n = 10) in a product volume of 7.4 +/- 0.5 mL (n = 67). Each of the 67 doses was injected intravenously into patients without complication as part of a phase I clinical trial. CONCLUSION: These data show that 213Bi-labeled antibody constructs can be prepared and administered safely to humans at a wide range of therapeutic levels.  (+info)

Pharmacokinetics and dosimetry of an alpha-particle emitter labeled antibody: 213Bi-HuM195 (anti-CD33) in patients with leukemia. (4/190)

Data from nine patients with leukemia participating in a phase I activity-escalation study of HuM195, labeled with the alpha-particle emitter 213Bi (half-life = 45.6 min), were used to estimate pharmacokinetics and dosimetry. This is the first trial using an alpha-particle emitter in humans. The linear energy transfer of alpha particles is several hundredfold greater than that of beta emissions. The range in tissue is approximately 60-90 microm. METHODS: The activity administered to patients ranged from 0.6 to 1.6 GBq. Patient imaging was initiated at the start of each injection. Thirty 1-min images followed by ten 3-min images were collected in dynamic mode; a 20% photopeak window centered at 440 keV was used. Blood samples were collected until 3 h postinjection and counted in a gamma counter. Contours around the liver and spleen were drawn on the anterior and posterior views and around a portion of the spine on the posterior views. No other organs were visualized. RESULTS: The percentage injected dose in the liver and spleen volumes increased rapidly over the first 10-15 min to a constant value for the remaining hour of imaging, yielding a very rapid uptake followed by a plateau in the antibody uptake curves. The kinetic curves were integrated to yield cumulated activity. The mean energy emitted per nuclear transition for 213Bi and its daughters, adjusted by a relative biologic effectiveness of 5 for alpha emissions, was multiplied by the cumulated activity to yield the absorbed dose equivalent. Photon dose to the total body was determined by calculating a photon-absorbed fraction. The absorbed dose equivalent to liver and spleen volumes ranged from 2.4 to 11.2 and 2.9 to 21.9 Sv, respectively. Marrow (or leukemia) mean dose ranged from 6.6 to 12.2 Sv. The total-body dose (photons only) ranged from 2.2 x 10(-4) to 5.8 x 10(-4) Gy. CONCLUSION: This study shows that patient imaging of 213Bi, an alpha-particle emitter, labeled to HuM195 is possible and may be used to derive pharmacokinetics and dosimetry. The absorbed dose ratio between marrow, liver and spleen volumes and the whole body for 213Bi-HuM195 is 1000-fold greater than that commonly observed with beta-emitting radionuclides used for radioimmunotherapy.  (+info)

Localization of tumor suppressor gene candidates by cytogenetic and short tandem repeat analyses in tumorigenic human bronchial epithelial cells. (5/190)

Radon exposure is associated with increased risk for bronchogenic carcinoma. Mutagenesis analyses have revealed that radon induces mostly multi-locus chromosome deletions. Based on these findings, it was hypothesized that deletion analysis of multiple radon-induced malignant transformants would reveal common mutations in chromosomal regions containing tumor suppressor genes responsible for malignant transformation. This hypothesis was supported by a previous study in which tumorigenic derivatives of the human papillomavirus 18-immortalized human bronchial epithelial cell line BEP2D were established following irradiation with 30 cGy of high linear energy transfer radon-simulated alpha-particles. Herein, we describe the analyses of 10 additional tumorigenic derivative cell lines resulting from the irradiation of five additional independent BEP2D populations. The new transformants have common cytogenetic changes, including the loss of chromosome (ch)Y, one of three copies of ch8, one of two copies of ch11p15-pter and one of three copies of ch14. These changes are the same as those reported previously. Analysis of PCR-amplified short tandem repeats of informative loci confirmed the loss of heterozygosity (LOH) at 12 loci spanning the length of ch8 in cell lines from four of the total of eight irradiation treatments to date and the loss of chY in all cell lines (8 of 8). LOH analysis with a total of 17 informative loci confirmed loss on ch14 in transformants from seven of eight irradiation treatments and indicated a 0.5-1.7 cM region of common involvement centered around locus D14S306. No LOH was detected at any of the informative loci on ch11. The overall results support our stated hypothesis. Further studies are currently in progress to determine whether the ch8 and ch14 regions contain genes with tumor suppressor function in bronchial epithelial cells.  (+info)

Induction of a bystander mutagenic effect of alpha particles in mammalian cells. (6/190)

Ever since the discovery of X-rays was made by Rontgen more than a hundred years ago, it has always been accepted that the deleterious effects of ionizing radiation such as mutation and carcinogenesis are attributable mainly to direct damage to DNA. Although evidence based on microdosimetric estimation in support of a bystander effect appears to be consistent, direct proof of such extranuclear/extracellular effects are limited. Using a precision charged particle microbeam, we show here that irradiation of 20% of randomly selected A(L) cells with 20 alpha particles each results in a mutant fraction that is 3-fold higher than expected, assuming no bystander modulation effect. Furthermore, analysis by multiplex PCR shows that the types of mutants induced are significantly different from those of spontaneous origin. Pretreatment of cells with the radical scavenger DMSO had no effect on the mutagenic incidence. In contrast, cells pretreated with a 40 microM dose of lindane, which inhibits cell-cell communication, significantly decreased the mutant yield. The doses of DMSO and lindane used in these experiments are nontoxic and nonmutagenic. We further examined the mutagenic yield when 5-10% of randomly selected cells were irradiated with 20 alpha particles each. Results showed, likewise, a higher mutant yield than expected assuming no bystander effects. Our studies provide clear evidence that irradiated cells can induce a bystander mutagenic response in neighboring cells not directly traversed by alpha particles and that cell-cell communication process play a critical role in mediating the bystander phenomenon.  (+info)

Factors underlying the cell growth-related bystander responses to alpha particles. (7/190)

Increases in cell proliferation are widely viewed as being of importance in carcinogenesis. We report that exposure of normal human lung fibroblasts to a low dose of alpha particles like those emitted by radon/radon progeny stimulates their proliferation in vitro, and this response also occurs when unirradiated cells are treated with supernatants from alpha-irradiated cells. We attribute the promitogenic response to superoxide dismutase- and catalase-inhibitable a particle-induced increases in the concentrations of transforming growth factor beta1 (TGF-beta1) in cell supernatants. TGF-beta1 at concentrations commensurate with those in the supernatants capably induces increases in intracellular reactive oxygen species (ROS) in unirradiated cells. Furthermore, the addition of supernatants from alpha-irradiated cells to unirradiated cells decreases cellular levels of TP53 and CDKN1A and increases CDC2 and proliferating cell nuclear antigen in the latter. Like the increased intracellular ROS bystander effect, this "decreased TP53/CDKN1A response" can be mimicked in otherwise untreated cells by the addition of low concentrations of TGF-beta1. Our results indicate that alpha particle-associated increases in cell growth correlate with intracellular increases in ROS along with decreases in TP53 and CDKN1A, and that these cellular responses are mechanistically coupled. As well, the proliferating cell nuclear antigen and CDC2 increases that occur along with the decreased TP53/CDKN1A bystander effect also would expectedly favor enhanced cell growth. Such processes may account for cell hyperplastic responses in the conducting airways of the lower respiratory track that occur after inhalation exposure to radon/ radon progeny, as well as, perhaps, other ROS-associated environmental stresses.  (+info)

Establishment of a radiation- and estrogen-induced breast cancer model. (8/190)

It is well accepted that cancer arises in a multistep fashion in which exposure to environmental carcinogens is a major etiological factor. The aim of this work was to establish an experimental breast cancer model in order to understand the mechanism of neoplastic transformation induced by high LET radiation in the presence of 17beta-estradiol (E). Immortalized human breast cells (MCF-10F) were exposed to low doses of high LET alpha particles (150 keV/microm) and subsequently cultured in the presence or absence of E for periods of up to 10 months post-irradiation. MCF-10F cells irradiated with either a single 60 cGy dose or 60/60 cGy doses of alpha particles showed gradual phenotypic changes including altered morphology, increase in cell proliferation relative to the control, anchorage-independent growth and invasive capability before becoming tumorigenic in nude mice. In alpha particle-irradiated cells and in those cells subsequently cultured in the presence of E, increased BRCA1, BRCA2 and RAD51 expression were detected by immunofluorescence staining and quantified by confocal microscopy. These studies showed that high LET radiation such as that emitted by radon progeny, in the presence of estrogen, induced a cascade of events indicative of cell transformation and tumorigenicity in human breast epithelial cells.  (+info)

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.

Actinium is a naturally occurring radioactive metallic element with the symbol Ac and atomic number 89. It was discovered in 1899 by André-Louis Debierne, a French chemist, who isolated it from uranium ore. Actinium is one of the actinides, a series of elements in the periodic table that are characterized by their radioactivity and their position in the f-block of the periodic table.

Actinium has no biological role in humans or other organisms, and exposure to its radiation can be harmful. It is not found in significant quantities in the environment, but it can be produced artificially through nuclear reactions. Actinium has a few potential medical applications, including as a component of radioactive compounds used for cancer treatment. However, its use in medicine is limited due to its radioactivity and toxicity.

Polonium is not a medical term, but a chemical element with symbol Po and atomic number 84. It is a rare and highly radioactive metal that occurs naturally in tiny traces as part of the uranium and thorium decay series. There is no known biological role for polonium, and exposure can be harmful or fatal due to its radioactivity. Medical professionals may encounter polonium in the context of radiation safety, nuclear medicine, or forensic investigations.

Radon is a colorless, odorless, radioactive gas that occurs as a result of the decay of radium in rocks and soil. It is denser than air and can accumulate in buildings, particularly in basements and lower levels without adequate ventilation. Inhalation of high concentrations of radon over time can increase the risk of developing lung cancer. Radon is measured in units of picocuries per liter (pCi/L) or becquerels per cubic meter (Bq/m3).

Radium is not a medical term per se, but it is a chemical element with symbol Ra and atomic number 88. It is a radioactive metal that decays spontaneously into radon gas, releasing alpha, beta, and gamma particles in the process. Radium has been used in medicine for various therapeutic purposes, such as in the treatment of cancer, due to its radiation properties.

In a medical context, radium is often used in the form of radium-223 dichloride (Xofigo), which is a radiopharmaceutical agent approved by the U.S. Food and Drug Administration (FDA) for the treatment of castration-resistant prostate cancer that has spread to bones. The radioactive emissions from radium-223 help slow or halt the growth of cancer cells in the bones, reducing pain and other symptoms associated with bone metastases.

It is important to note that radium should only be used under the supervision of trained medical professionals, as it can pose significant health risks if not handled properly due to its radioactive properties.

In the context of medicine, the term "elements" generally refers to the basic constituents or parts that make up a whole. These can include chemical elements, such as carbon, hydrogen, and oxygen, which are the building blocks of biological molecules like proteins, lipids, and carbohydrates.

However, "elements" can also refer more broadly to the fundamental components of a system or process. For example, in traditional humorism, one of the ancient medical systems, the four "elements" were considered to be black bile, yellow bile, phlegm, and blood, which were believed to correspond to different temperaments and bodily functions.

In modern medicine, the term is less commonly used, but it may still refer to the basic components of a biological or chemical system, such as the elements of a chemical reaction or the building blocks of a cell.

Radionuclide generators, also known as "radiogenic sources" or "generator systems," are devices that contain a parent radionuclide that decays into a daughter radionuclide. The parent nuclide has a longer half-life than the daughter nuclide and remains within the generator system, while the daughter nuclide is produced continuously through the decay process and can be extracted for use in medical imaging or therapeutic procedures.

The most common type of radionuclide generator used in nuclear medicine is the technetium-99m (^99m Tc) generator, which contains molybdenum-99 (^99 Mo) as the parent nuclide. Molybdenum-99 has a half-life of 66 hours and decays into technetium-99m, which has a half-life of only 6 hours. Technetium-99m emits gamma rays that can be detected by gamma cameras, making it useful for a wide range of diagnostic procedures such as bone scans, lung perfusion imaging, and myocardial perfusion imaging.

Radionuclide generators are typically used in hospitals and medical centers where they can provide a convenient and cost-effective way to produce small quantities of radionuclides for diagnostic or therapeutic purposes. The extracted daughter nuclide can be used immediately, reducing the need for complex shipping and handling procedures associated with other radioactive materials.

I'm sorry for any confusion, but "Neon" is not a medical term. Neon is actually a noble gas, the fourth lightest and second most abundant in the Earth's atmosphere. It is used in vacuum tubes and high-voltage indicators, and in advertising signs and neon lamps. If you have any medical terms you would like me to define, please let me know!

I'm sorry for any confusion, but "Uranium" is not a medical term. It is a chemical element with the symbol "U" and atomic number 92. Uranium is a dense, silvery-gray metal that is hard and brittle at room temperature. It's primarily used as a fuel in nuclear power plants and in the manufacture of weapons.

While uranium does not have direct medical applications, it does pose potential health risks due to its radioactivity. Exposure to high levels of radiation from uranium can lead to acute radiation sickness, anemia, and an increased risk of cancer. However, under normal circumstances, the general public is not exposed to significant amounts of uranium, so it's not a common health concern.

In the context of medical and health sciences, particle size generally refers to the diameter or dimension of particles, which can be in the form of solid particles, droplets, or aerosols. These particles may include airborne pollutants, pharmaceutical drugs, or medical devices such as nanoparticles used in drug delivery systems.

Particle size is an important factor to consider in various medical applications because it can affect the behavior and interactions of particles with biological systems. For example, smaller particle sizes can lead to greater absorption and distribution throughout the body, while larger particle sizes may be filtered out by the body's natural defense mechanisms. Therefore, understanding particle size and its implications is crucial for optimizing the safety and efficacy of medical treatments and interventions.

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.

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.

The "bystander effect" is a social psychological phenomenon in which the presence of other people discourages an individual from intervening in an emergency situation. It is also known as bystander apathy or Genovese syndrome. This effect was named after the infamous murder of Kitty Genovese in 1964, where it was reported that dozens of witnesses heard her screams for help but did not call the police or intervene.

The bystander effect is thought to occur because individuals in a group may assume that someone else will take action, or they may feel uncertain about how to respond and hesitant to get involved. Additionally, the presence of other people can dilute an individual's sense of personal responsibility for taking action. The bystander effect has been demonstrated in numerous experiments and real-world situations, and it highlights the importance of encouraging individuals to take action and intervene in emergency situations, even when others are present.

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.

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.

Boron Neutron Capture Therapy (BNCT) is a type of targeted radiation therapy used in the treatment of certain types of cancer. It involves the use of a boron-containing compound, which selectively accumulates in cancer cells. Once the compound has been taken up by the cancer cells, the patient is exposed to a beam of low-energy neutrons. When the neutrons interact with the boron-10 isotope within the compound, a nuclear reaction occurs, producing high-energy alpha particles that destroy the cancer cells.

The advantage of BNCT is that it allows for targeted delivery of radiation to cancer cells while minimizing exposure to healthy tissues. However, this type of therapy is still experimental and is only available in a limited number of medical centers worldwide. It has been studied most extensively in the treatment of brain tumors, head and neck cancers, and melanoma.

I'm sorry for any confusion, but "mining" is not a term that has a widely accepted medical definition. It is most commonly associated with the extraction of minerals from the earth in the field of geology and mining engineering. If you have any questions related to health or medicine, I would be happy to try to help answer those for you!

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.

Fibroblasts are specialized cells that play a critical role in the body's immune response and wound healing process. They are responsible for producing and maintaining the extracellular matrix (ECM), which is the non-cellular component present within all tissues and organs, providing structural support and biochemical signals for surrounding cells.

Fibroblasts produce various ECM proteins such as collagens, elastin, fibronectin, and laminins, forming a complex network of fibers that give tissues their strength and flexibility. They also help in the regulation of tissue homeostasis by controlling the turnover of ECM components through the process of remodeling.

In response to injury or infection, fibroblasts become activated and start to proliferate rapidly, migrating towards the site of damage. Here, they participate in the inflammatory response, releasing cytokines and chemokines that attract immune cells to the area. Additionally, they deposit new ECM components to help repair the damaged tissue and restore its functionality.

Dysregulation of fibroblast activity has been implicated in several pathological conditions, including fibrosis (excessive scarring), cancer (where they can contribute to tumor growth and progression), and autoimmune diseases (such as rheumatoid arthritis).

Alpha 1-antitrypsin (AAT, or α1-antiproteinase, A1AP) is a protein that is primarily produced by the liver and released into the bloodstream. It belongs to a group of proteins called serine protease inhibitors, which help regulate inflammation and protect tissues from damage caused by enzymes involved in the immune response.

Alpha 1-antitrypsin is particularly important for protecting the lungs from damage caused by neutrophil elastase, an enzyme released by white blood cells called neutrophils during inflammation. In the lungs, AAT binds to and inhibits neutrophil elastase, preventing it from degrading the extracellular matrix and damaging lung tissue.

Deficiency in alpha 1-antitrypsin can lead to chronic obstructive pulmonary disease (COPD) and liver disease. The most common cause of AAT deficiency is a genetic mutation that results in abnormal folding and accumulation of the protein within liver cells, leading to reduced levels of functional AAT in the bloodstream. This condition is called alpha 1-antitrypsin deficiency (AATD) and can be inherited in an autosomal codominant manner. Individuals with severe AATD may require augmentation therapy with intravenous infusions of purified human AAT to help prevent lung damage.

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... while alpha particles deposit their energy in 70-100 μm long tracks. Alpha particles are more likely than other types of ... "Targeted alpha therapy using short-lived alpha-particles and the promise of nanobodies as targeting vehicle". Expert Opinion on ... Targeted alpha-particle therapy (or TAT) is an in-development method of targeted radionuclide therapy of various cancers. It ... The short path length of alpha particles in tissue, which makes them well suited to treatment of the above types of disease, is ...
... , for Spirit (MER-A) and Opportunity (MER-B) Mars Exploration Rovers. Alpha Particle X-ray ... They include alpha particles, protons, and X-rays. Alpha particles, protons, and X-rays are emitted during the radioactive ... So it is also called alpha particle X-ray spectrometer. The alpha particles are also able to eject electrons from the inner ... The energy spectrum of the scattered alpha particle shows peaks from 25% up to nearly 100% of the initial alpha particles. This ...
Khoshbin-e-Khoshnazar, M. R. (2002). "Correlated Quasiskyrmions as Alpha Particles". Eur. Phys. J. A. 14 (2): 207-209. Bibcode: ... alpha \beta }\operatorname {tr} L_{\nu }L_{\alpha }L_{\beta },} where ϵ μ ν α β {\displaystyle \epsilon ^{\mu \nu \alpha \beta ... In particle theory, the skyrmion (/ˈskɜːrmi.ɒn/) is a topologically stable field configuration of a certain class of non-linear ... "Particle-like topologies in light". Nature Communications. 12 (1): 6785. doi:10.1038/s41467-021-26171-5. ISSN 2041-1723. PMC ...
Alpha particles were emitted with characteristic energy, and she expected that this would be true of beta particles too. Hahn ... She started with alpha particles. In her experiments with collimators and metal foil, she found that scattering in a beam of ... But how could barium be formed from uranium? No larger fragments than protons or helium nuclei (alpha particles) had ever been ... Hahn equipped it with electroscopes to measure alpha and beta particles and gamma rays. It was not possible to conduct research ...
alpha particles - Helium-4 nucleus; particle of two protons and two neutronsPages displaying short descriptions of redirect ... this occurs on a daily basis in all particle collider experiments. The problem of alpha particle track was discussed at the ... Consequently Mott is assuming that the alpha particle barely notices the atoms it excites as it races through the cloud chamber ... Mott starts with a spherical wave for the alpha particle and two representative cloud chamber atoms modeled as hydrogen atoms. ...
Coyne, John P.; Ball, David W. (2009). "Alpha particle chemistry. On the formation of stable complexes between He2+ and other ...
Ernest Rutherford discovered the alpha and beta particles emitted by uranium; 1900 - Paul Villard discovered the gamma ray in ... The timeline of particle physics lists the sequence of particle physics theories and discoveries in chronological order. The ... "Fermilab , Science , Particle Physics , Key Discoveries". www.fnal.gov. Retrieved 26 August 2020. Fukuda, Y.; et al. (Super- ... "CERN experiments observe particle consistent with long-sought Higgs boson". CERN. Retrieved 22 May 2020. LHCb Collaboration (4 ...
Gamma rays from antimony-124 split beryllium-9 into two alpha particles and a neutron with an average kinetic energy of 24keV, ... The incoming gamma ray effectively knocks one or more neutrons, protons, or an alpha particle out of the nucleus. The reactions ... The other products are two alpha particles. Other isotopes have higher thresholds for photoneutron production, as high as 18.72 ... and immediately decays by emitting a subatomic particle. ...
Alpha particles are also attenuated by the window. As alpha particles have a maximum range of less than 50 mm in air, the ... For alpha particles, low energy beta particles, and low energy X-rays, the usual form is a cylindrical end-window tube. This ... It is used for the detection of gamma radiation, X-rays, and alpha and beta particles. It can also be adapted to detect ... The neutrons interact with the boron nuclei, producing alpha particles, or directly with the helium-3 nuclei producing hydrogen ...
Holloway, M. G.; Livingston, Stanley (July 1938). "Range and Specific Ionization of Alpha-Particles". Physical Review. American ... "Range and specific ionization of alpha particles". Cornell University. Retrieved September 25, 2009. ... alpha particle), and the cross section of a deuterium-tritium interaction to form 3 2He. These calculations were for evaluating ... where he wrote his Doctor of Philosophy thesis on the Range and Specific Ionization of Alpha Particles. Holloway married Wilma ...
William, E.J., studied beta particle straggling, Multiple scattering of fast electrons and alpha particles, and cloud curvature ... deuterons and alpha particles, and equilibrium charge states of ions in solids and energies of elastically scattered particles ... alpha )={\cos \theta _{1}\cos \alpha } \over {\sin \phi {\sqrt {\cos ^{2}\alpha -\cos ^{2}\theta _{1}}}-\cos \theta _{1}\cos \ ... His theory later extended to multiple scattering of alpha particles. Goudsmit and Saunderson provided a more complete treatment ...
Newton, Amos S. (1 January 1949). "The Fission of Thorium with Alpha-Particles". Physical Review. 75 (1): 17-29. Bibcode: ... Thus in the 50.5 days it takes half the 89Sr atoms to decay, emitting the same number of beta particles as there were decays, ... Fission products do not decay via alpha decay.) A few neutron-rich and short-lived initial fission products decay by ordinary ... The first beta decays are rapid and may release high energy beta particles or gamma radiation. However, as the fission products ...
... alpha particles between 2.0 and 200 MeV; heavy particles with Z values ranging from 2 to 5 with energies greater than 8 MeV; ... alpha particles between 8.4 and 35.0 MeV in two ranges (111, 112 channels); Z greater than or equal to 2 between 2.2 and 8.4 ... heavy particles with Z values ranging between 6 and 8 with energies greater than 32 MeV; and integral protons and alphas of ... solid-state particle telescope. The experiment measured particle energies from 0.1 to 10 MeV per charge in 12 bands and ...
Alpha particles leaving at millions of electronvolts. Electrons leaving at high energy. Light radiation (IR, visible, UV, X-ray ... If a particle follows the field line and enters a region of higher field strength, the particles can be reflected. Several ... Their fusion releases no neutrons, but produces energetic charged alpha (helium) particles whose energy can directly be ... and thus the reaction rate on a per-particle basis, the density of particles within that volume, and finally the confinement ...
... these are positively-charged particles emitted by certain radioactive substances such as radium). The alpha particles were ... They spotted alpha particles being deflected by angles greater than 90°. To explain this, Rutherford proposed that the positive ... Only such an intense concentration of charge could produce an electric field strong enough to deflect the alpha particles as ... Rutherford didn't think he'd run into this same problem because alpha particles are much heavier than electrons. According to ...
Alpha particles, produced by the decay of radon and polonium, leave tracks of charge on the silicon wafers when they impact the ... The Alpha Particle Spectrometer (APS) was a cube approximately 18 cm (7.1 in) colocated with the neutron spectrometer on the ... The APS recorded alpha particle signatures of radioactive decay of radon gas and its byproduct product, polonium. These ... "Alpha Particle Spectrometer results". Lunar Prospector website. NASA. Archived from the original on 2005-12-26. Retrieved 2006- ...
Although beta particles scatter much more than alpha particles, a range can still be defined; it frequently amounts to several ... For example, if the ionising particle passing through the material is a positive ion like an alpha particle or proton, it will ... The range of alpha particles in ambient air amounts to only several centimeters; this type of radiation can therefore be ... Since the mass of the proton or alpha particle is much greater than that of the electron, there will be no significant ...
The alpha particle is not the most dangerous particle associated with NORM, as an external hazard. Alpha particles are ... Beta particles are electrons or positrons and can travel farther than alpha particles in air. They are in the middle of the ... Alpha particles travel short distances in air, of only 2-3 cm, and cannot penetrate through a dead layer of skin on the human ... Radium radionuclides emit alpha and beta particles as well as gamma rays. The radiation emitted from a radium 226 atom is 96% ...
It decays by either emitting an alpha particle (with a decay energy of 5.27 MeV) to become 239Np, which then quickly decays to ... The artificial element decays by ejecting alpha particles. Americium has an atomic number of 95 (the number of protons in the ... Possible parent nuclides: beta from 241Pu, electron capture from 241Cm, alpha from 245Bk. Americium-241 decays by alpha ... No alpha activity attributable to the new isomer has been detected; the alpha half-life is probably greater than 300 [years]." ...
The first hypothesis for this alpha particle accumulation was contamination by uranium, which produces alpha-decay particles; ... Plutonium is fairly stable, but undergoes alpha-decay, which explained the presence of alpha particles coming from neptunium. ... analysis of alpha-decay particles ruled this out. Seaborg then postulated that a distinct alpha-producing element was being ... Seaborg first reported alpha decay proportionate to only a fraction of the element 93 under observation. ...
1937). Disintegration of Aluminum by Polonium Alpha-Particles. Physical Review. 52(4): 266. Kanne, W. Rudolph. (15 August 1937 ... 1937). Disintegration of Aluminum by Polonium Alpha-Particles. Physical Review. 52(4): 266. Editor. (30 November 1962). 34 ...
Rutherford, Ernest (1919). "Collision of alpha particles with light atoms IV. An anomalous effect in nitrogen". Philosophical ...
"alpha particle mass energy equivalent". NIST. Retrieved 4 November 2011. Calculated: 7×10−4 g × 9.8 m/s2 × 1×10−4 m "Conversion ... Particle Data Group. Archived from the original on 17 July 2012. Retrieved 4 November 2011. "Conversion from eV to J". NIST. ... 2008). "Review of Particle Physics⁎". Physics Letters B. 667 (1): 1-6. Bibcode:2008PhLB..667....1A. doi:10.1016/j.physletb. ...
... emits mostly alpha particles, but other steps in its decay chain (the uranium or radium series) emit alpha or beta particles, ... alpha particles, beta particles, and gamma rays. More specifically, natural radium (which is mostly 226Ra) ... The alpha particles emitted by radium quickly gain two electrons to become neutral helium, which builds up inside and weakens ... ISBN 978-3-527-31097-5. l'Annunziata, Michael F. (2007). "Alpha particle induced nuclear reactions". Radioactivity: ...
His thesis was on column ionization of alpha particles. From 1931 to 1934, Diebner was Gerhard Hoffmann's teaching assistant at ...
Radon then can emit alpha particles and gamma radiation. The three different radioactive isotopes of uranium are uranium-238, ... P., Carvalho, Fernando; M., Oliveira, João; Isabel, Faria (2009). "Alpha Emitting Radionuclides in Drainage from Quinta do ... Carvalho, Fernando P.; Oliveira, João M.; Faria, Isabel (November 2009). "Alpha emitting radionuclides in drainage from Quinta ...
The channelling of protons and alpha particles into crystals. Having developed (with Jean Mory and Georges Désarmot) the " ... His research is on the physics of materials and in particular on the study of the interaction of particles with solids and the ...
Unfortunately, this was very unlikely because both alpha particles and nuclei are positively charged - the alpha particles ... Each time an alpha particle reached the screen it produced a flash. He then introduced nitrogen into the chamber and observed ... Occasionally, an alpha particle would collide with a nitrogen nucleus and get absorbed by it, knocking out a proton in the ... Rutherford fixed a source of alpha particles - each of which contains two protons - at one end of a cylindrical chamber. At the ...
Alpha-particle radiotherapy with fast-clearing radiopeptide shows efficacy in treating solid tumors in a preclinical study. ... When the tumor is very small, alpha particles are more effective than beta particles in irrigating the tumor," he said. "They ... among mice injected with the alpha-emitting particle and mice injected with the beta-emitting particle. Mice that received no ... Specifically, complete remission of cancer was achieved in 70% of mice that were injected with the alpha-emitting particle, ...
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This is due to the strong non-linearity of losses near the end of the path of alpha particles and to the different positions of ... The mean energy loss of alpha particle was estimated by Bethe Bloch formulae. The dependence of energy losses on the order of ... The energy loss of alpha particles in thin layers of various absorbers, including those composed of various materials was ... This effect can contribute to the expansion of a single Bragg peak in alpha spectrometry. ...
We studied the alpha-radiation risks in patients who received injections of Thorotrast, an X-ray contrast medium used in Europe ... Alpha-particle carcinogenesis in Thorotrast patients: epidemiology, dosimetry, pathology, and molecular analysis Y Ishikawa 1 ... Alpha-particle carcinogenesis in Thorotrast patients: epidemiology, dosimetry, pathology, and molecular analysis Y Ishikawa et ... Mutations in the tumor suppressor gene p53 in human liver cancer induced by alpha-particles. Andersson M, Jönsson M, Nielsen LL ...
Alpha particles, such as Thorium-227, are several thousand times larger than beta particles. Before now, alpha emitters have ... Clinical trial with alpha particle radiation treatment attempts to target and destroy cancer cells On July 23, Keith Grant ( ... Thorium-227 is an unstable radio-isotope that emits an alpha particle upon undergoing radioactive decay, explained Dr. Frank ... But, the higher the mass or energy of the emitted particle, the more tumor damage can be done. ...
Alpha particles, such as Thorium-227, are several thousand times larger than beta particles. Before now, alpha emitters have ... Clinical trial with alpha particle radiation treatment attempts to target and destroy cancer cells On July 23, Keith Grant ( ... Thorium-227 is an unstable radio-isotope that emits an alpha particle upon undergoing radioactive decay, explained Dr. Frank ... But, the higher the mass or energy of the emitted particle, the more tumor damage can be done. ...
a positively charged particle consisting of two protons and two neutrons, emitted in radioactive decay or nuclear fission; the ... alpha particle - UK / US noun [countable] Word forms alpha particle : singular alpha particle plural alpha particles physics ... alpha-particle scattering. Look at other dictionaries:. *. Alpha particle - Alpha particles (named after and denoted by the ... alpha particle - alfa dalelė statusas T sritis fizika atitikmenys: angl. alpha particle vok. Alpha Teilchen, n rus. альфа ...
alpha rays. Alpha particles, also known as alpha rays, consist of two protons and two neutrons bound together into a particle ... alpha rays. Alpha particles, also known as alpha rays, consist of two protons and two neutrons bound together into a particle ... Alpha particles. Products of nuclear decay that are each made up of two protons and two neutrons, which form a particle with a ... Alpha particle. A product of nuclear decay that is two protons and two neutrons, which form a particle with a structure ...
This image shows the impact of alpha particles from seven radioactive atoms in a random sample of dust from an air filter from ... Each of the marks show the damage done to CR-39 plastic by the alpha particle emitted when a single uranium, plutonium or ... Some of the particles land in the sea. Those which wash up on shorelines dry out and are known to travel miles inland even in ... The radioactive particles that created these marks on this piece of CR-39 (50mm x 25mm), the size of a microscope slide, were ...
Penetration of Protons, Alpha Particles, and Mesons U Fano Vol. 13 (1963), pp. 1-66 ... The Low-Energy Frontier of Particle Physics Joerg Jaeckel, and Andreas Ringwald ...
When plutonium particles are inhaled, they lodge in the lung tissue. The alpha particles can kill lung cells, which causes ... Mode of decay: Alpha particles. Chemical properties: Solid under normal conditions, plutonium can form compounds with other ... Because it emits alpha particles, plutonium is most dangerous when inhaled. ... meaning that the blood and the kidneys will be exposed to alpha particles. Once plutonium circulates through the body, it ...
Saturation of alpha particle driven instability in Tokamak Fusion Test Reactor journal, February 1999 * Gorelenkov, N. N.; Chen ... Sensitivity of alpha-particle-driven Alfvén eigenmodes to q-profile variation in ITER scenarios journal, July 2016 * Rodrigues ... Predictive nonlinear studies of TAE-induced alpha-particle transport in the Q = 10 ITER baseline scenario journal, July 2016 * ... Alfvénic instabilities driven by fusion generated alpha particles in ITER scenarios journal, December 2005 * Vlad, G.; ...
Radionuclides (alpha-particle-emitting): All cancer sites combined. *Radionuclides (beta-particle-emitting): All cancer sites ... a mixture of tiny solid particles and liquid droplets in the air). ...
New Calculations Solve an Alpha Particle Physics Puzzle. Learn More .texture-box--image-690416 {background-image: url(https:// ... UAS measurements with surface analysis techniques created a more accurate description of the 3-D structure of aerosol particles ...
Electron microscopy shows alpha and beta glycogen particles. Diffuse deposition of amylopectin-like materials in the heart, ...
"Alpha particle scattering" experiment [Senior Secondary Physics]. The sequence was highly captivating; but the alpha particles ...
Monitoring-systems; Airborne-particles; Alpha-emitters; Worker-health; Work-environment; Workplace-monitoring; Uranium- ... Laboratory analysis of air samples indicated a wide range of potential exposures to the alpha-emitting particulate. Logarithmic ... This analysis indicates the magnitude and distributions of worker exposure to alpha-emitting airborne particulate. Additional ...
The radiation given off is alpha particles, beta particles, and gamma rays. This radiation gives a radiation dose to people ... An atom of 222Rn gives off an alpha particle (which is the size of a helium atom without electrons), transforming into an atom ... which later gives off an alpha particle of its own, transforming into an atom of radioactive lead (214Pb). The final step in ... Decay products of 222Rn, such as 218Po and 214Pb, are solids that can attach to particles in the air and be transported this ...
Alpha-Particle Emission in Ternary Fission. RADIOACTIVITY 252Cf(SF); analyzed α-accompanied fission data; deduced spherical ... On the Alpha- and Cluster-Decays of the Double Giant Dipole Resonance of Fissioning Nuclei. doi: 10.1007/BF03035951 Citations: ... Collective and Particle-States in 174Yb from the Decay of 174Lu. NUCLEAR STRUCTURE 174Lu; measured not abstracted; deduced ... Energy Spectra of Single Neutrons and Charged Particles Emitted Following the Absorption of Stopped Negative Pions in 4He. ...
The space agency also shared an image that illustrates the energy variations in proton and alpha particle counts captured by ... The histogram illustrates the energy variations in proton and alpha particle counts captured by SWIS over 2-days.… pic.twitter. ... that illustrates the energy variations in proton and alpha particle counts captured by the new payload. ... The Solar Wind Ion Spectrometer (SWIS), the second instrument in the Aditya Solar wind Particle Experiment (ASPEX) payload is ...
Alpha Particles as Radiopharmaceuticals in the Treatment of Bone Metastases February 8, 2019 ...
C and alpha-particles with energy range 0.5-10 MeV. The results from a dynamic model indicate that the temporal alpha-radiation ... MeSH Terms: Alpha Particles; Bone Remodeling/physiology*; Bone Remodeling/radiation effects*; Bone and Bones/physiology*; Bone ... Title: Radiation dose to trabecular bone marrow stem cells from (3)H, (14)C and selected alpha-emitters incorporated in a bone ... C and a set of alpha-emitters incorporated within a bone remodeling compartment (BRC). The BRC consists of a well-oxygenated ...
Trojan horse particle invariance studied with the 6Li(d, alpha)4He and 7Li(p, alpha)4He reactions. Szerzők. Pizzone R. G., ... New measurement of the 11B(p, alpha 0)8Be bare-nucleus S(E) factor via the Trojan horse method. Szerzők. Lamia L., Spitaleri C. ... Improved results on the extraction of 11B(p, alpha 0)8Be S(E)-factor via the Trojan Horse Method. Szerzők. Lamia L., Spitaleri ... Study of reaction 17O(p, alpha)14N via the Trojan Horse Method for application to 17O nucleosynthesis. Szerzők. Sergi M. L., ...
As an alpha-particle-emitting decay product of radium-226 (226Ra), 210Po is classified as a Group 1 human carcinogen [ ... A single alpha particle can induce bystander effects in a population of cells, thus the sensitivity of primary oocytes to low ... 210Po has a relatively short half-life of 138.4 days and decays to lead-206 (206Pb) by emitting an alpha particle. It is the ... 1999). Alpha particles traversing the nucleus of HeLa cells produced a track averaging 10 µm, with an average of 22 double- ...
  • To a lesser extent, this is also true of very high-energy helium nuclei produced by particle accelerators. (wikipedia.org)
  • Some science authors use doubly ionized helium nuclei (He2+ ) and alpha particles as interchangeable terms. (wikipedia.org)
  • The nomenclature is not well defined, and thus not all high-velocity helium nuclei are considered by all authors to be alpha particles. (wikipedia.org)
  • Thus, alpha particles may be loosely used as a term when referring to stellar helium nuclei reactions (for example the alpha processes), and even when they occur as components of cosmic rays. (wikipedia.org)
  • Alpha particles are commonly emitted by all of the larger radioactive nuclei such as uranium, thorium, actinium, and radium, as well as the transuranic elements. (wikipedia.org)
  • The smallest nuclei that have to date been found to be capable of alpha emission are beryllium-8 and antimony-104, not counting beta-delayed alpha emission of some lighter elements. (wikipedia.org)
  • The nuclei of these atoms are very "neutron rich" (i.e. have a lot more neutrons in their nucleus than they do protons) which makes emission of the alpha particle possible. (isu.edu)
  • Alpha Particle-- A positively charged particle ejected spontaneously from the nuclei of some radioactive elements. (cdc.gov)
  • Alpha particles are helium nuclei emitted by various elements, including radium. (medscape.com)
  • At the time being, information on the nuclear structure of SHE nuclei has been derived mainly via studying the alpha-particles emitted as the SHE nuclei decay. (lu.se)
  • For even mass nuclei such decays involve almost exclusively alpha decays from ground state (mother) to ground state (daughter). (lu.se)
  • This means that instead of identifying the superheavy nuclei indirectly via their subsequent decay (alpha particles) the nuclei will now be directly identified via the emitted X-rays. (lu.se)
  • They are generally produced in the process of alpha decay, but may also be produced in other ways. (wikipedia.org)
  • Due to the mechanism of their production in standard alpha radioactive decay, alpha particles generally have a kinetic energy of about 5 MeV, and a velocity in the vicinity of 4% of the speed of light. (wikipedia.org)
  • See discussion below for the limits of these figures in alpha decay. (wikipedia.org)
  • They are a highly ionizing form of particle radiation, and (when resulting from radioactive alpha decay) usually have low penetration depth (stopped by a few centimetres of air, or by the skin). (wikipedia.org)
  • A higher energy version of alphas than produced in alpha decay is a common product of an uncommon nuclear fission result called ternary fission. (wikipedia.org)
  • When an atom emits an alpha particle in alpha decay, the atom's mass number decreases by four due to the loss of the four nucleons in the alpha particle. (wikipedia.org)
  • Examples of this sort of nuclear transmutation by alpha decay are the decay of uranium to thorium, and that of radium to radon. (wikipedia.org)
  • Unlike other types of decay, alpha decay as a process must have a minimum-size atomic nucleus that can support it. (wikipedia.org)
  • In contrast to beta decay, the fundamental interactions responsible for alpha decay are a balance between the electromagnetic force and nuclear force. (wikipedia.org)
  • Alpha decay results from the Coulomb repulsion between the alpha particle and the rest of the nucleus, which both have a positive electric charge, but which is kept in check by the nuclear force. (wikipedia.org)
  • Alpha decay is a radioactive process in which a particle with two neutrons and two protons is ejected from the nucleus of a radioactive atom. (isu.edu)
  • Alpha decay only occurs in very heavy elements such as uranium, thorium and radium. (isu.edu)
  • Uranium undergoes alpha decay, releasing energy in the form of kinetic energy. (managenergy.tv)
  • Its ability to undergo alpha decay, releasing energy in the form of kinetic energy, makes it an ideal candidate for use in nuclear reactors. (managenergy.tv)
  • The science behind harnessing uranium's energy lies in its ability to undergo alpha decay, releasing kinetic energy in the form of alpha particles. (managenergy.tv)
  • When uranium undergoes alpha decay, it emits high-energy alpha particles. (managenergy.tv)
  • Alpha decay occurs due to the interplay between the strong nuclear force and the electromagnetic force. (managenergy.tv)
  • The primary mechanism of uranium toxicity is direct DNA damage caused by interactions with alpha particles released during its decay. (managenergy.tv)
  • Radiation can also be produced by high energy particles that are a product of radioactive decay. (medscape.com)
  • Because it emits alpha particles, plutonium is most dangerous when inhaled. (cdc.gov)
  • Alpha particles, also called alpha rays or alpha radiation, consist of two protons and two neutrons bound together into a particle identical to a helium-4 nucleus. (wikipedia.org)
  • After an atom ejects an alpha particle, a new parent atom is formed which has two less neutrons and two less protons. (isu.edu)
  • Because alpha particles contain two protons, they have a positive charge of two. (isu.edu)
  • Further, alpha particles are very heavy and very energetic compared to other common types of radiation. (isu.edu)
  • The demand for instrumentation capable of detecting and triggering on ionizing radiation in high-rate particle physics experiments at colliding-beam and fixed-target accelerator facilities and for spacecraft-borne instrumentation in astrophysics has led to the development of new tracking technologies. (annualreviews.org)
  • The radiation given off is alpha particles, beta particles, and gamma rays. (cdc.gov)
  • The effects of radiation are radiation have concentrated on low- -particle with an energy of 2 MeV directly related to the dose received has an LET of about 180 keV/m. dose exposures, typical y of 0.1 Gy by individual cel s or organs, and All types of ionizing radiation in- (= 0.1 J/kg) and below. (who.int)
  • Once the ion gains electrons from its environment, the alpha particle becomes a normal (electrically neutral) helium atom 4 2He. (wikipedia.org)
  • Beta particles are electrons. (medscape.com)
  • 3. High detection efficiency of the K and L X-rays emitted in coincidence with the alpha particles and associated conversion electrons. (lu.se)
  • The particle is identical to the nucleus of a helium atom. (isu.edu)
  • Thus, when uranium-238 (which has a Z of 92) decays by alpha emission, thorium-234 is created (which has a Z of 90). (isu.edu)
  • As it decays, actinium-225 produces three daughter atoms, each of which also gives out alpha particles. (foxnews.com)
  • In classical physics, alpha particles do not have enough energy to escape the potential well from the strong force inside the nucleus (this well involves escaping the strong force to go up one side of the well, which is followed by the electromagnetic force causing a repulsive push-off down the other side). (wikipedia.org)
  • This is allowed by the wave nature of matter, which allows the alpha particle to spend some of its time in a region so far from the nucleus that the potential from the repulsive electromagnetic force has fully compensated for the attraction of the nuclear force. (wikipedia.org)
  • To reach the nucleus, alpha particles require substantial energy. (managenergy.tv)
  • However, the quantum tunnelling effect allows alphas to escape even though they do not have enough energy to overcome the nuclear force. (wikipedia.org)
  • Especially energetic alpha particles deriving from a nuclear process are produced in the relatively rare (one in a few hundred) nuclear fission process of ternary fission. (wikipedia.org)
  • Most plutonium in the environment is in the form of microscopic particles that are the remnants of nuclear weapons testing and nuclear reactor accidents. (cdc.gov)
  • Alpha Track-- The track of ionized atoms (pattern of ionization) left in a medium by an alpha particle that has traveled through the medium. (cdc.gov)
  • The additional alpha particles from the daughter atoms can be deadly to nearby cells. (foxnews.com)
  • However, so-called long range alpha particles from ternary fission are three times as energetic, and penetrate three times as far. (wikipedia.org)
  • The image also features abstracted particle trails and various graphics representing particle accelerator structure. (rsc.org)
  • As with beta and gamma particles/rays, the name used for the particle carries some mild connotations about its production process and energy, but these are not rigorously applied. (wikipedia.org)
  • Electron microscopy shows alpha and beta glycogen particles. (medscape.com)
  • Most HPVs belong to genera alpha (e.g., genital and wart-associated types), beta, or gamma (cutaneous types) ( 1 ). (cdc.gov)
  • Adsorption Coefficient (Koc)-- The ratio of the amount of a chemical adsorbed per unit surface area or per unit weight of organic carbon of a specific particle size in the soil or sediment to the concentration of the chemical in solution at equilibrium. (cdc.gov)
  • Uranium can have negative health effects due to its toxic properties and ability to cause DNA damage through interactions with alpha particles. (managenergy.tv)
  • Each of the daughters can release an alpha particle that can kill a cell," said Scheinberg. (foxnews.com)
  • Activity Median Aerodynamic Diameter (AMAD)-- The diameter of a unit-density sphere with the same terminal settling velocity in air as that of the aerosol particle whose activity is the median for the entire size distribution of the aerosol. (cdc.gov)
  • A high yield of alpha particles has been detected in the 6He+120Sn collision with velocities around the velocity of the scattered 6He. (usp.br)
  • Most SOA research has focused on ozone reactions with single terpenoids or with consumer products, and this paper reports the results from an investigation of SOA formation from ozone reactions with both single terpenoids and mixtures of D-limonene, alpha-pinene, and alpha-terpineol. (cdc.gov)
  • The results showed grouping of HPVXS2 as virus-like particles. (cdc.gov)
  • Levels are considered to be far exceeding the federal regulatory limit, with nearly 1,000 times the normal amount of alpha particles recorded, including. (naturalnews.com)
  • These particles possess a significant amount of potential energy, approximately 6.1 MeV. (managenergy.tv)
  • In an extended focal plane, TASISpec places pixelized silicon detectors for particles and high-resolution germanium gamma-ray detectors around it in an extremely compact way. (lu.se)
  • These characteristics allow alpha particles to interact readily with materials they encounter, including air, causing many ionizations in a very short distance. (isu.edu)
  • Ionizing radia- distribution of internal radionuclides per unit mass (the absorbed dose, tions are usual y classified as either that emit short-range -particles or expressed in units of gray, where electro magnetic or particulate. (who.int)
  • Improvements in particle confinement, for instance, may increase the burden on engineers to build more complex coils, and the tightening of financial constraints may simplify the design and worsen some aspects of transport. (cambridge.org)