Alpha Particles: Positively charged particles composed of two protons and two NEUTRONS, i.e. equivalent to HELIUM nuclei, which are emitted during disintegration of heavy ISOTOPES. Alpha rays have very strong ionizing power, but weak penetrability.Nuclear Physics: The study of the characteristics, behavior, and internal structures of the atomic nucleus and its interactions with other nuclei. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)Radioactivity: The spontaneous transformation of a nuclide into one or more different nuclides, accompanied by either the emission of particles from the nucleus, nuclear capture or ejection of orbital electrons, or fission. (McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)Actinium: 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: 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.Neutrons: Electrically neutral elementary particles found in all atomic nuclei except light hydrogen; the mass is equal to that of the proton and electron combined and they are unstable when isolated from the nucleus, undergoing beta decay. Slow, thermal, epithermal, and fast neutrons refer to the energy levels with which the neutrons are ejected from heavier nuclei during their decay.Radon: A naturally radioactive element with atomic symbol Rn, atomic number 86, and atomic weight 222. It is a member of the noble gas family found in soil, and is released during the decay of radium.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.Physics: The study of those aspects of energy and matter in terms of elementary principles and laws. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)Elements: 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.Semiconductors: Materials that have a limited and usually variable electrical conductivity. They are particularly useful for the production of solid-state electronic devices.Plastics: Polymeric materials (usually organic) of large molecular weight which can be shaped by flow. Plastic usually refers to the final product with fillers, plasticizers, pigments, and stabilizers included (versus the resin, the homogeneous polymeric starting material). (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)Astatine: Astatine. A radioactive halogen with the atomic symbol At, atomic number 85, and atomic weight 210. Its isotopes range in mass number from 200 to 219 and all have an extremely short half-life. Astatine may be of use in the treatment of hyperthyroidism.Lead Radioisotopes: Unstable isotopes of lead that decay or disintegrate emitting radiation. Pb atoms with atomic weights 194-203, 205, and 209-214 are radioactive lead isotopes.Hot Temperature: Presence of warmth or heat or a temperature notably higher than an accustomed norm.Patents as Topic: Exclusive legal rights or privileges applied to inventions, plants, etc.Bismuth: A metallic element that has the atomic symbol Bi, atomic number 83 and atomic weight 208.98.Radioisotopes: Isotopes that exhibit radioactivity and undergo radioactive decay. (From Grant & Hackh's Chemical Dictionary, 5th ed & McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)Argon: Argon. A noble gas with the atomic symbol Ar, atomic number 18, and atomic weight 39.948. It is used in fluorescent tubes and wherever an inert atmosphere is desired and nitrogen cannot be used.Spectrometry, Mass, Electrospray Ionization: A mass spectrometry technique used for analysis of nonvolatile compounds such as proteins and macromolecules. The technique involves preparing electrically charged droplets from analyte molecules dissolved in solvent. The electrically charged droplets enter a vacuum chamber where the solvent is evaporated. Evaporation of solvent reduces the droplet size, thereby increasing the coulombic repulsion within the droplet. As the charged droplets get smaller, the excess charge within them causes them to disintegrate and release analyte molecules. The volatilized analyte molecules are then analyzed by mass spectrometry.Environment: The external elements and conditions which surround, influence, and affect the life and development of an organism or population.Electron Transport: The process by which ELECTRONS are transported from a reduced substrate to molecular OXYGEN. (From Bennington, Saunders Dictionary and Encyclopedia of Laboratory Medicine and Technology, 1984, p270)Americium: Americium. A completely man-made radioactive actinide with atomic symbol Am, atomic number 95, and atomic weight 243. Its valence can range from +3 to +6. Because of its nonmagnetic ground state, it is an excellent superconductor. It is also used in bone mineral analysis and as a radiation source for radiotherapy.Electrons: Stable elementary particles having the smallest known negative charge, present in all elements; also called negatrons. Positively charged electrons are called positrons. The numbers, energies and arrangement of electrons around atomic nuclei determine the chemical identities of elements. Beams of electrons are called CATHODE RAYS.Linear Energy Transfer: Rate of energy dissipation along the path of charged particles. In radiobiology and health physics, exposure is measured in kiloelectron volts per micrometer of tissue (keV/micrometer T).Xenon: A noble gas with the atomic symbol Xe, atomic number 54, and atomic weight 131.30. It is found in the earth's atmosphere and has been used as an anesthetic.Xenon Isotopes: Stable xenon atoms that have the same atomic number as the element xenon, but differ in atomic weight. Xe-124, 126, 128-131, 134, and 136 are stable xenon isotopes.Gamma Rays: Penetrating, high-energy electromagnetic radiation emitted from atomic nuclei during NUCLEAR DECAY. The range of wavelengths of emitted radiation is between 0.1 - 100 pm which overlaps the shorter, more energetic hard X-RAYS wavelengths. The distinction between gamma rays and X-rays is based on their radiation source.Visual Perception: The selecting and organizing of visual stimuli based on the individual's past experience.Periodicals as Topic: A publication issued at stated, more or less regular, intervals.Wireless Technology: Techniques using energy such as radio frequency, infrared light, laser light, visible light, or acoustic energy to transfer information without the use of wires, over both short and long distances.Indium: A metallic element, atomic number 49, atomic weight 114.82, symbol In. It is named from its blue line in the spectrum. (From Dorland, 28th ed)Blogging: Using an INTERNET based personal journal which may consist of reflections, comments, and often hyperlinks.Resins, Plant: Flammable, amorphous, vegetable products of secretion or disintegration, usually formed in special cavities of plants. They are generally insoluble in water and soluble in alcohol, carbon tetrachloride, ether, or volatile oils. They are fusible and have a conchoidal fracture. They are the oxidation or polymerization products of the terpenes, and are mixtures of aromatic acids and esters. Most are soft and sticky, but harden after exposure to cold. (From Grant & Hackh's Chemical Dictionary, 5th ed & Dorland, 28th ed)Electronics: The study, control, and application of the conduction of ELECTRICITY through gases or vacuum, or through semiconducting or conducting materials. (McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)Professional Corporations: Legally authorized corporations owned and managed by one or more professionals (medical, dental, legal) in which the income is ascribed primarily to the professional activities of the owners or stockholders.Cadmium Compounds: Inorganic compounds that contain cadmium as an integral part of the molecule.Scattering, Radiation: The diversion of RADIATION (thermal, electromagnetic, or nuclear) from its original path as a result of interactions or collisions with atoms, molecules, or larger particles in the atmosphere or other media. (McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)Scattering, Small Angle: Scattering of a beam of electromagnetic or acoustic RADIATION, or particles, at small angles by particles or cavities whose dimensions are many times as large as the wavelength of the radiation or the de Broglie wavelength of the scattered particles. Also know as low angle scattering. (McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed) Small angle scattering (SAS) techniques, small angle neutron (SANS), X-ray (SAXS), and light (SALS, or just LS) scattering, are used to characterize objects on a nanoscale.Particle Size: Relating to the size of solids.X-Ray Diffraction: The scattering of x-rays by matter, especially crystals, with accompanying variation in intensity due to interference effects. Analysis of the crystal structure of materials is performed by passing x-rays through them and registering the diffraction image of the rays (CRYSTALLOGRAPHY, X-RAY). (From McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)Quantum Theory: The theory that the radiation and absorption of energy take place in definite quantities called quanta (E) which vary in size and are defined by the equation E=hv in which h is Planck's constant and v is the frequency of the radiation.Portraits as Topic: Graphic representations, especially of the face, of real persons, usually posed, living or dead. (From Thesaurus for Graphic Materials II, p540, 1995)History, 17th Century: Time period from 1601 through 1700 of the common era.RNA Interference: A gene silencing phenomenon whereby specific dsRNAs (RNA, DOUBLE-STRANDED) trigger the degradation of homologous mRNA (RNA, MESSENGER). The specific dsRNAs are processed into SMALL INTERFERING RNA (siRNA) which serves as a guide for cleavage of the homologous mRNA in the RNA-INDUCED SILENCING COMPLEX. DNA METHYLATION may also be triggered during this process.Protons: Stable elementary particles having the smallest known positive charge, found in the nuclei of all elements. The proton mass is less than that of a neutron. A proton is the nucleus of the light hydrogen atom, i.e., the hydrogen ion.Spectrometry, Mass, Fast Atom Bombardment: A mass spectrometric technique that is used for the analysis of a wide range of biomolecules, such as glycoalkaloids, glycoproteins, polysaccharides, and peptides. Positive and negative fast atom bombardment spectra are recorded on a mass spectrometer fitted with an atom gun with xenon as the customary beam. The mass spectra obtained contain molecular weight recognition as well as sequence information.Magnetic Resonance Spectroscopy: Spectroscopic method of measuring the magnetic moment of elementary particles such as atomic nuclei, protons or electrons. It is employed in clinical applications such as NMR Tomography (MAGNETIC RESONANCE IMAGING).

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 particle

... being an alpha particle. Such alpha particles are termed "long range alphas" since at their typical energy of 16 MeV, they are ... see alpha decay). The energy of alpha particles emitted varies, with higher energy alpha particles being emitted from larger ... Alpha particles are named after the first letter in the Greek alphabet, α. The symbol for the alpha particle is α or α2+. ... The alpha particles were detected by a zinc sulfide screen, which emits a flash of light upon an alpha particle collision. ...

*Alpha-particle spectroscopy

Energetics of alpha decay: The alpha particle, or 4He nucleus, is an especially strongly bound particle. This combined with the ... many alpha emitters is to use alpha-particle spectroscopy. For methods of gamma rays and beta particles, please see gamma ... will be divided between the alpha-particle and the heavy recoiling daughter so that the kinetic energy of the alpha particle ... This is because some of the energy of the alpha particles is lost during their movement through the layer of active material. ...

*Targeted alpha-particle therapy

... 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 ...

*Alpha particle X-ray spectrometer

... , 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 ... The energy spectrum of the scattered alpha particle shows peaks from 25% up to nearly 100% of the initial alpha particles. This ... Light elements absorb more energy of the alpha particle, while alpha particles are reflected by heavy nuclei nearly with the ...

*Helium hydride ion

Coyne, John P.; Ball, David W. (2009). "Alpha particle chemistry. On the formation of stable complexes between He2+ and other ...

*Nuclear binding energy

... alpha particles are fast helium nuclei). (Beryllium-8 also decays, very quickly, into two alpha particles.) Alpha particles are ... The most common isotope of thorium, 232Th, also undergoes alpha particle emission, and its half-life (time over which half a ... alpha particles). This spontaneous break-up is one of the forms of radioactivity exhibited by some nuclei. Nuclei heavier than ... usually as alpha particles, which consist of two protons and two neutrons ( ...

*Lunar Prospector

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 damaged during launch, ruining one of the five detecting faces. Additionally, due to ... The APS recorded alpha particle signatures of radioactive decay of radon gas and its byproduct product, polonium. These ... The neutron spectrometer was a thin cylinder colocated with the Alpha Particle Spectrometer at the end of one of the three ...

*Orders of magnitude (energy)

"alpha particle mass energy equivalent". NIST. Retrieved 4 November 2011. Calculated: 7e-4 g * 9.8 m/s2 * 1e-4 m "Conversion ... Particle Data Group. Retrieved 4 November 2011. "Conversion from eV to J". NIST. Retrieved 4 November 2011. Amsler, C.; Doser, ... "Review of Particle Physics⁎". Physics Letters B. 667: 1-6. Bibcode:2008PhLB..667....1A. doi:10.1016/j.physletb.2008.07.018. [ ...

*Radium

... 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, with builds up inside and weakens ... ISBN 978-3-527-31097-5. l'Annunziata, Michael F. (2007). "Alpha particle induced nuclear reactions". Radioactivity: ...

*Photodisintegration

The incoming gamma ray effectively knocks one or more neutrons, protons, or an alpha particle out of the nucleus. The reactions ... The other product is two alpha particles. Other isotopes have higher thresholds for photoneutron production, as high as 18.72 ... and immediately decays by emitting a subatomic particle. ...

*Marshall Holloway

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 ...

*Fusion power

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. There are ... Cross sections for many fusion reactions were measured (mainly in the 1970s) using particle beams. In a plasma, particle ... which releases alpha (helium) particles, but does not rely on neutron scattering for energy transfer. 1H + 11B → 3 4He Under ...

*Atomic theory

Given the very small mass of the electrons, the high momentum of the alpha particles, and the low concentration of the positive ... In 1917 Rutherford bombarded nitrogen gas with alpha particles and observed hydrogen nuclei being emitted from the gas ( ... To their astonishment, a small fraction of the alpha particles experienced heavy deflection. Rutherford concluded that the ... Rutherford, Ernest (1919). "Collisions of alpha Particles with Light Atoms. IV. An Anomalous Effect in Nitrogen". Philosophical ...

*Nuclear Power and the Environment

From there certain particles can cause ionization. The ionizing particles are alpha particles (a type of ionizing radiation ... "Radiation: Alpha Particles". US Environmental Protection Agency. EPA. Retrieved 7 November 2014. "Radiation: Beta Particles". ... beta particles (subatomic particles ejected from the nucleus of some radioactive atoms that are equivalent to electrons), gamma ... Barrens, Richard E. "Beta Particles and Ionization". Newton. DOE Office of Science. Retrieved 7 November 2014. ...

*Radioimmunotherapy

... with alpha-particle emitting radionuclides. Q J Nucl Med Mol Imaging. 2004 Dec;48(4):289-96. Burke JM, ... A set of radioimmunotherapy drugs that rely upon an alpha particle-emitting isotope (e.g., Bi-213 or, preferably, Ac-225), ...

*Geiger-Müller tube

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 ...

*William Rudolph Kanne

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 ...

*Oxygen-17

Rutherford, Ernest (1919). "Collision of alpha particles with light atoms IV. An anomalous effect in nitrogen". Philosophical ... 17O (n,alpha) → 14C. Some tritium removal facilities make a point of replacing the oxygen of the water with natural oxygen ( ...

*Isotopes of dubnium

A. Ghiorso; Nurmia, Matti; Eskola, Kari; Eskola, Pirkko (1971). "Two New Alpha-Particle Emitting Isotopes of Element 105, 261Ha ... "A new alpha-particle-emitting isotope 259Db". Eur. Phys. J. A. 10: 1. Bibcode:2001EPJA...10...21G. doi:10.1007/s100500170140. R ... They observed two alpha lines which they tentatively assigned to 261Db and 260Db. They repeated their experiment in 1970 ... These decays have been linked to an isomeric level decaying by alpha decay with a half-life of ~19 s. Further research is ...

*Epsilon radiation

Alpha particle Gamma ray ""EC Electron capture"". Archived from the original on February 15, 2005. ... Epsilon rays are a form of particle radiation and are composed of electrons. The term was coined by J. J. Thomson, but is very ...

*Kurt Diebner

His thesis was on column ionization of alpha particles. From 1931 to 1934, Diebner was Gerhard Hoffmann's teaching assistant at ...

*Uranium acid mine drainage

Radon then can emit alpha particles and gamma radiation. Three different radioactive isotopes of uranium are uranium-238, ... P., Carvalho, Fernando; M., Oliveira, João; Isabel, Faria,. "Alpha Emitting Radionuclides in Drainage from Quinta do Bispo and ... Carvalho, Fernando P.; Oliveira, João M.; Faria, Isabel (November 2009). "Alpha emitting radionuclides in drainage from Quinta ...

*Chemistry: A Volatile History

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 ...

*Van Allen radiation belt

Most of the ions are in the form of energetic protons, but a certain percentage are alpha particles and O+ oxygen ions, similar ... Most of the particles that form the belts are thought to come from solar wind and other particles by cosmic rays. By trapping ... Other nuclei, such as alpha particles, are less prevalent. The belts endanger satellites, which must have their sensitive ... Particles spiral along the magnetic lines of flux as they move "longitudinally" along those lines. As particles move toward the ...

*Alpha decay

An alpha particle can be thought of as being inside a potential barrier whose walls are 25 MeV. However, decay alpha particles ... Alpha decay or α-decay is a type of radioactive decay in which an atomic nucleus emits an alpha particle (helium nucleus) and ... Americium-241, an alpha emitter, is used in smoke detectors. The alpha particles ionize air in an open ion chamber and a small ... Alpha decay occurs in such nuclei as a means of increasing stability by reducing size. One curiosity is why alpha particles, ...

*1931 in the United States

January 2 - South Dakota native Ernest Lawrence invents the cyclotron, used to accelerate particles to study nuclear physics. ... December 26 - Phi Iota Alpha, the oldest existing Latino fraternity, is founded. Elizabeth Dilling begins anti-communist ...
Alpha particles are emitted mainly by the heaviest of the isotopes (e.g., all elements above bismuth (Bi-209) are radioactive, and most are alpha particle emitters. These nuclei are too big to be stable and decay by emitting an alpha particle. Very often the resulting nucleus, called a "Daughter nucleus", is also too big and unstable. It too usually emits an alpha particle. This process can happen a number of times depending upon the starting isotope and the ultimate stable isotope. The stable isotope of the alpha emitters is usually lead (the element just below Bismuth, and has 4 stable isotopes for the "Decay Chains" to stop on). For example, the most abundant isotope of uranium, U-238, it takes the emission of 5 alpha particles to get to stable lead.. Alpha particles are high speed helium atoms without electrons. Consisting of a nucleus of 2 protons and 2 neutrons, this is the largest common (naturally occurring) radiation particle. Since there are no electrons, the alpha particle is highly ...
Get an answer for Alpha radiation is a strong ionizer, but it can only penetrate through few cm of air. How then can alpha particles cause human biological damage? and find homework help for other Science questions at eNotes
1. The predictions of Rutherfords scattering formula failed to correspond with experimental data when the energy of the incoming alpha particles exceeded 32MeV. This can be explained by the fact that the predictions of the formula apply when the only force involved is the electromagnetic force and will break down if the incoming particles make contact with the nucleus. Use the fact that Rutherfords prediction ceases to be valid for alpha particles with an energy greater than 32MeV to estimate the radius r of the gold nucleus. ...
An alpha particle is made up of two protons and two neutrons. An alpha particle is common in the field of nuclear physics because it is one of the three particles emitted during radioactive decay....
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sources]. Typically, when radiation treatment is recommended for cancer patients, doctors are able to choose from several radiopharmaceuticals that use low-energy radiation particles, known as beta particles.. For years, scientists have been studying how to use "alpha particles," which are radioactive particles that contain a large amount of energy, in cancer treatments.. The challenges to using alpha particles, which are more than 7,000 times heavier than beta particles, include confining the powerful alpha particles in a designated location inside the body while preventing radiation from wandering to healthy organs and tissues.. "If you think of beta particles as slingshots or arrows, alpha particles would be similar to cannon balls," says J. David Robertson, director of research at the University of Missouri Research Reactor and professor of chemistry in the College of Arts and Science.. "Scientists have had some successes using alpha particles recently, but nothing that can battle different ...
The energy of emitted alpha particles was a mystery to early investigators because it was evident that they did not have enough energy, according to classical physics, to escape the nucleus. Once an approximate size of the nucleus was obtained by Rutherford scattering, one could calculate the height of the Coulomb barrier at the radius of the nucleus. It was evident that this energy was several times higher than the observed alpha particle energies. There was also an incredible range of half lives for the alpha particle which could not be explained by anything in classical physics.. The resolution of this dilemma came with the realization that there was a finite probability that the alpha particle could penetrate the wall by quantum mechanical tunneling. Using tunneling, Gamow was able to calculate a dependence for the half-life as a function of alpha particle energy which was in agreement with experimental observations ...
The energy of emitted alpha particles was a mystery to early investigators because it was evident that they did not have enough energy, according to classical physics, to escape the nucleus. Once an approximate size of the nucleus was obtained by Rutherford scattering, one could calculate the height of the Coulomb barrier at the radius of the nucleus. It was evident that this energy was several times higher than the observed alpha particle energies. There was also an incredible range of half lives for the alpha particle which could not be explained by anything in classical physics.. The resolution of this dilemma came with the realization that there was a finite probability that the alpha particle could penetrate the wall by quantum mechanical tunneling. Using tunneling, Gamow was able to calculate a dependence for the half-life as a function of alpha particle energy which was in agreement with experimental observations. ...
Beta-decay to, followed by alpha-particle deexcitation of, the following levels has been investigated: the 7.656-Mev and 10.1-Mev levels in c^(12), the 8.88-Mev, 9.59-Mev, and 9.85-Mev levels in O^(16), and the 5.63-Mev and 5.80-Mev levels in Ne^(20). Groups of delayed alpha particles were observed only from the first, second and fourth of these levels. The beta-unstable parent nuclei were formed through (d,p) reactions on B^(11), N^(15), and F^(19), after which the delayed alpha particles were observed for a period of time comparable to the half-life of the beta-decay process. The beta-decay branching ratio to the 9.59-Mev level in O^(16) was measured and is equal to (1.4 ± 0.2) • 10^(-5) corresponding to a log ft (9.59) = 6.5 ± 0.2. The beta-decay branching ratio to the 9.85-Mev level was found to be less than 2.7 • 10^(-7) which corresponds to a log ft (9. 85) ≥ 7.2 ± 0.2. The ratio of the decay probability for alpha-particle emission to the total decay probability for the 8.88-Mev ...
testing facility, and then broadened the net to see who else had been in contact with the alpha radiation. As of Thursday, there were 195 workers with urine samples sent away for testing, a number that Saunders called conservative.. Of those initial 19 directly affected, 14 results have come back in line with the companys prediction that they would be under the regulatory limits of alpha radiation. The highest dosage was 20.6mSv, while the low dosage was 11.5 mSv.. The maximum dose acceptable for nuclear workers is 100mSv (10,000 mrem) over a five-year period, with no more than 50mSv in any given year.. Alpha radiation cannot penetrate the skin, but may be dangerous if inhaled or exposed to an open wound. It can cause radiation poisoning and chromosome damage.. Sawyer told the CNSC that each worker that has been tested will be met with one-on-one to discuss the results and how the testing was done. He also mentioned that independent testing will be done to give the workers peace of mind, which ...
The need of a stable production of At-211 is necessary to continue research in alpha-particle targeted radionuclide therapy. Our objectives were to establish the production of Astatine-211 at Texas A&M Cyclotron Institute, optimize the production methods to reduce the generation of contaminants and maximize At-211 production, and assess the radiological safety aspects of At-211 production. The production of the alpha-particle emitting radionuclide At-211 was performed at the Texas A&M Cyclotron Institute using the K500 superconducting cyclotron following the production reaction Bi-209(α, 2n)At-211 using a thick bismuth target of 500 μm. We carried out two irradiation experiments where the initial energy of the alpha-particle beam, 80 MeV, was degraded using multiple copper and aluminum foils to 27.8 and 25.3 MeV, respectively. The end of beam time was 4 hours for both experiments. The resulting At-211 yields were 36.0 and 12.4 MBq/μA-h, respectively. Several impurities were produced using the ...
Radiation comes in two different varieties: ionizing and non-ionizing radiation. Were only concerned with ionizing radiation because its able to damage biological tissue.. Ionizing radiation comes in several different types: alpha particles, beta particles, neutron particles, x-rays and gamma rays. Theres some important differences between them that you should know.. Alpha particles are the bowling balls of radiation. Theyre big, heavy and slow moving. Because of their large size they dont penetrate very far. In fact, they cant even penetrate clothing or the thin layer of dead skin cells we all have. Alpha emitting contamination is not much of a threat, unless its swallowed or inhaled. Alpha radiation can cause significant internal damage.. Beta particles are smaller than alpha particles and penetrate further. Clothing will stop most beta particles, but they can penetrate exposed skin and cause skin damage. Theyre also very damaging if swallowed or inhaled.. Neutron particles are very ...
TY - JOUR. T1 - Alpha particle mutagenesis of human lymphoblastoid cell lines. AU - Amundson, S. A.. AU - Chen, D. J.. AU - Okinaka, R. T.. PY - 1996. Y1 - 1996. N2 - Despite being derived from the same donor, the human lymphoblastoid cell lines WTK1 and TK6 have markedly different responses to low LET radiation. We originally observed that WTK1 was more resistant to the cytotoxic effects of X-irradiation, but significantly more sensitive to mutation induction at both the TK and HPRT loci. In an effort to better understand these properties, we have examined the effects of α-particles on these cells. Relative to TK6, WTK1 has enhanced survival and mutation after both X-ray and α-particle exposure. While the HPRT locus was significantly more mutable in WTK1 as a function of α-particle versus X-ray dose, the TK locus was only slightly more sensitive to a-particle mutagenesis. In addition, the slowly growing TK mutants that constitute the majority of X-ray-induced TK mutants of TK6 were recovered ...
The idea that one alpha particle (with LET approximately 100keV/micrometers) traversing a cell nucleus would kill a cell has been a concept which has been traditionally accepted by most radiation biologists. It was, therefore, difficult to see how al
When a 7 3 Li nucleus is bombarded with protons α particles emerge.Calculate the kinetic energy of the alpha particle assuming the kinetic energy of the bombarding proton to be negligible. Given M (7 3 Li)=7.016004a.m.u. M (p)=1.007826a.m.u and M (α)=4.002603a.m.u ...
presumably must now change and take the form of the dashed curve in the figure. Staying with our example of an atom of U-238, we find that an escaping alpha particle (following the same tunnel as before) emerges to be accelerated through a voltage drop and to a final energy half again as great as before - to about 6 mev. Reference to Figure 1 (main text) suggests that we should suddenly find that the half-life of every atom of U-238 at the surface of the Earth has been reduced from 4.5 billion years to something like 1 second! On this basis, any abrupt lowering of Earth potential by a mere million volts could be expected to produce rampant radioactivity, with consequent lethal or at least strongly mutational effects on all forms of life.. But of course we are probably unjustified in assuming that Figure 1[2] is applicable to the postulated conditions; it may well be that changing Earth potentials also shift the curve of Figure 1 up or down, right or left, so that changes in half-lives are much ...
Measured alpha particle hits per unit tumour area per 1 hour for two groups of tumour sections: 4 sections with and 3 sections without application of chemothera
INDIUM: Alpha particles are emitted from certain element isotopes, and can potentially change the binary output of a semiconductor from a 0 to a 1 or from a 1 to...
Demonstration This demonstration forms a part of the discussion about the scattering experiment performed by Geiger and Marsden for Rutherford. It uses the repulsive forces between magnets to represent the forces between nuclei and alpha particles.
Calculate the charge on alpha particle. Given charge on a proton = +1.6 × 10-19 .... Ask questions, doubts, problems and we will help you.
Numerous studies have reported on cancers among Mayak Production Association (PA) nuclear workers. Other studies have reported on serious deterministic effects of large radiation doses for the same population. This study relates to deterministic effects (respiratory system dysfunction) in Mayak workers after relatively small chronic radiation doses (alpha plus gamma). Because cigarette smoke is a confounding factor, we also account for smoking effects. Here we present a new empirical mathematical model that was introduced for simultaneous assessment of radiation and cigarette-smoking-related damage to the respiratory system. The model incorporates absolute thresholds for smoking- and radiation-induced respiratory system dysfunction. As the alpha radiation dose to the lung increased from 0 to 4.36 Gy, respiratory function indices studied decreased, although remaining in the normal range. The data were consistent with the view that alpha radiation doses to the lung above a relatively small ...
Irradiation is the exposure to radiation from a source located at some distance outside the body. Irradiation from a source of alpha radiation presents a low risk because alpha radiation is easily absorbed - by air, clothing, or the layer of dead skin cells on your skin. Contamination is the exposure to radiation from a source inside your body, or on your skin or clothes. This is generally more dangerous, because cells are unprotected. ...
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Glycogen, a highly branched polymer of glucose, functioning as a blood-glucose buffer. It comprises relatively small beta particles, which may be joined as larger aggregate alpha particles. The molecular size distributions from size-exclusion chromatography of liver glycogen from non-diabetic and diabetic mice show that diabetic mice have impaired alpha particle formation in liver glycogen, with diabetic mice unable to form as many large glycogen particles as non-diabetic controls. Glycogen structure is analysed during degradation by acid hydrolysis and by glycogen phosphorylase, from the size distributions, obtained using size-exclusion chromatography, of pig-liver glycogen and phytoglycogen as functions of time and size. These experiments show that alpha particles degrade via a different mechanism to that of the smaller beta particles, indicating a different type of chemical bonding (most likely proteinaceous). This shows that diabetic mice, which have been shown to lack the larger alpha ...
A series of analytic and numerical models have been developed for the prediction and interpretation of the energy spectrum of the neutron emission from thermonuclear deuteriumtritium (DT) plasmas. The main component of the neutron emission, due to reactions between thermal fuel ions, has been modeled as well as minority components due to the presence of fast (supra-thermal) ions. In particular, the so-called alpha-particle knock-on neutron (AKN) emission has been analyzed and found to carry information on the con- finement of fast alpha particles inside the plasma. The alpha particles carry one fifth of the fusion power generated in the plasma and provide the plasma self-heating. This thesis is devoted to this central endeavor of fusion research and the possibilities for its study in todays largest magnetic confinement devices, the tokamaks.. The developed models have been used for the interpretation of experimental data taken during the first deuterium-tritium experiment (DTE1) at the Joint ...
Micromegas is a type of micro-pattern gaseous detector currently under R&D for applications in rare event search experiments. Here we report the perfor
Matter is composed of atoms or groups of atoms called molecules. The arrangement of particles in a material depends on the physical state of the substance. In a solid, particles form a compact structure that resists flow. Particles in a liquid have more energy than those in a solid. They can flow past one another, but they remain close. Particles in a gas have the most energy. They move rapidly and are separated from one another by relatively large distances. ...
Radiation can harm either the whole body (somatic damage) or eggs and sperm (genetic damage). Its effects are more pronounced in cells that reproduce rapidly, such as the stomach lining, hair follicles, bone marrow, and embryos. This is why patients undergoing radiation therapy often feel nauseous or sick to their stomach, lose hair, have bone aches, and so on, and why particular care must be taken when undergoing radiation therapy during pregnancy.. Different types of radiation have differing abilities to pass through material ([link]). A very thin barrier, such as a sheet or two of paper, or the top layer of skin cells, usually stops alpha particles. Because of this, alpha particle sources are usually not dangerous if outside the body, but are quite hazardous if ingested or inhaled (see the Chemistry in Everyday Life feature on Radon Exposure). Beta particles will pass through a hand, or a thin layer of material like paper or wood, but are stopped by a thin layer of metal. Gamma radiation is ...
by their supply chain. Supply chain Vendors sell both Low Alpha (LA) materials and packages or Ultra Low Alpha (ULA) ones. Low Alpha means that the emission rate is below 0.1 alpha/cm2/hr Ultra Low Alpha materials produce emission rates below 0.01 alpha/cm2/hr ...
The larger and more charged the radiation the more ionizations occur. Alpha particles are very highly ionizing, thus would have a larger LET than a low energy gamma. Alpha particles will cause more biological damage in a very small area ...
With the onset of the Northern Hemisphere winter, an intense surface high- pressure system develops over the East Asia continental region, centered south of Lake Baikal. The dominating characteristics of this anticyclone can be seen by noting the huge geographical area over which it lies. The anticyclone is sustained and intensified by strong radiational cooling over the frozen land mass and by consistent cold air advection from Arctic latitudes.. The occurrences of winter season cold air outbreaks cause high pressure to extend eastward over coastal waters off the China mainland. Strong winds turning anticyclonically around this eastern extension of high pressure and the associated weather is referred to as a Northeast Monsoonal Surge (NEMS). These surges produce strong, steady, northerly to northeasterly monsoon winds along the East Asian coast near Sakhalin Island, across the Sea of Japan, the Yellow Sea, the East China Sea, the Philippine Sea and into the South China Sea.. A cold surge or ...
To ionize an atom of any element requires the expenditure of a certain amount of work, dependent upon the particular element concerned. This energy may be acquired through impact with a rapidly moving electron, positive ion, or neutral atom, or through absorption of radiation. We shall be concerned with ionization by the impact of positive ions and [alpha]-particles. Suppose the colliding particle has more than sufficient energy to affect the removal of one electron, what is the net result of the collision? May it happen under certain favourable conditions that a second electron is removed, or does the ionization process invariably consist in the removal of a single electron? It was the object of this research to supply further experimental proof for the theory that more than one electron may be dislodged by single impact. Up until 1911 we had no unambiguous information as to what really happens when a high speed particle collides with a normal atom. It was not known with certainty whether one ...
Resonances in the yield of ground-state protons from alpha-particle bombardment of 31P were investigated in the energy range Eα = 1.7 − 3.3 MeV. Fourteen resonances were observed, none of which was known before. Resonance energies and strengths are presented. Angular distribution measurements lead to unique values of the resonance ... read more spin in all cases but one. The exception is the strong resonance at Eα = 3.302 MeV, which shows a deviation from forward-backward symmetry in the angular distribution, to be explained by assuming interference with some unknown broad resonance(s) with opposite parity, probably at higher energy. show less ...
Not that there is usually quite a low amount of tritium naturally, and that makes it mostly irrelevant in terms of radiation emitted as compared to other natural sources. But of course if one is working in the lab with H3 Labelled molecules, care not to ingest it is necessary, the low energy of the alpha radiation means however that there is really very little need to handle with special protection. The only danger comes from ingestion and metabolization of the tritiated material ...
Heres some more info: carcinogens are commonly radioactive. In this case, it is not the substance itself, but the gamma and alpha radiation that the substance releases (forms of high frequency light) that cause the cell damage. This makes cigarettes and alcoholic beverages particularly dangerous because of the high levels of radiation that they contain.. Beyond chemical carcinogens, there are several microbial agents that are known carcinagens. HPV (Human Paploma Virus, the virus that causes warts) and Hepititus B are examples.. There are also a multitude of carcinogens that naturally form on meat cooked at high temperatures (grilling or broiling for example).. ...
Vapor cigarettes a day received 400 rads in the bronchi of alpha radiation per year equivalent to 300 torso radiographs or nearly one day make our world cartomizerer and health experts for incorrect testing approaches and it is not an easy task. But the most important of their places. They also offer you longer easier draws. E Cigarette Cartridge Refill India It works much longer than any other alternative to traditional smoker. Fresh E-Liquid direct from manufacturer supplies the perfect prospective to tobacco habit hard. Businesses have already been using the same one to minimize tobacco complexities. You can use a variety of adapters too in addition to smoke cigarettes. In this way you would not really is inadvisable that have to watch out for the batteries one does not hit the market. You can get your own via that when Enter e cigarette liquid bulk The Cabin can easily wash E Cigarette Cartridge Refill India cartridge contains the e-liquid is a mixture of liquid nicotine and other countries. ...
With respect to the cell as a whole, radiation seems like mosquitoes attacking a circus tent, but once inside, high-energy particles or rays can wreak havoc upon individual atoms and molecules that make up our cellular structure. Alpha particles, protons, and neutrons scatter whatever is in their path, using their mass energy to separate electrons from their parent nuclei. Beta rays whiz through a thin layer of cells, knocking other electrons out of their orbits until their rather limited energy is expended. Gamma and X-rays act similarly, but with a vengeance proportional to their energies and inversely proportional to their wavelengths. [Light, which is part of the same electromagnetic spectrum as both X-rays and gamma rays, behaves similarly. Long wavelength infrared light - otherwise known as radiant heat - has very little energy compared to short wavelength ultraviolet light... which can "ultraviolate" you on the beach if you dont use sunblock ...
Synonyms for Alpha radication in Free Thesaurus. Antonyms for Alpha radication. 2 words related to alpha particle: subatomic particle, particle. What are synonyms for Alpha radication?
Looking for alpha emission? Find out information about alpha emission. Ejection of alpha particles from the atoms nucleus Explanation of alpha emission
Alpha particle: Charged particles emitted from a radioactive atom. Each charged particle consists of two protons and two neutrons. Atom: This is the smalle
When nuclear fuel, fabricated for the purpose of transmuting spent fuel is irradiated, significant amounts of He is produced from alpha particles mainly emitted when 242Cm decays into 238Pu. From irradiation experiments it is known that the presence of He in the solids alters the swelling behaviour of the material. The thesis presents the theoretical background from which nucleation models of He bubbles can be formulated. Such models are presented for He in metals, and the case of He in Mo is studied as an example. MgO, which together with Mo is suggested as a matrix material in transmutation fuel is also studied and the stability of He containing bubbles in this material is discussed.. By calculating parameters for a rate theory model derived from atomistic modelling, it is shown that He can stabilise vacancy clusters and cause cluster growth at temperatures and irradiation doses where nucleation and growth would not otherwise occur. At the initial stages of nucleation He can stabilise small ...
We form OH- molecules, which falls to the ground, carrying their negative charge with them. The He2+ alpha particles, drift to above the cloud. But we get high electric fields. So we get a chain of molecular nuclear fusion occurring, which forms a chain to the ground. Then we get the main strike, upwards, to return the e- to the positive holes.[lxiv] ...
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A thermal vias-provided cavity-down IC package structure of the invention is provided. The thermal vias-provided cavity-down IC package structure includes a substrate, a heat sink and an adhesive layer for attaching the substrate to the heat sink. The substrate is formed of multiple layers of printed circuit boards which are attached to each other, and have a cavity formed at the center thereof. A plurality of thermal vias is formed surrounding the substrate. The head sink is divided into a chip mount area and a thermal via joint area. The chip mount area is used for a chip mount pad to be disposed thereon, wherein a chip is connected to the heat sink through the chip mount pad. The thermal via area is electrically coupled to the thermal vias thereby to form an approximate short path or a short path. Thus, heat energy is transferred not only by the heat sink directly, but also from the heat sink to the substrate through the thermal vias. Furthermore, since the depth of the chip mount area is adjustable,
Before I order a barrel, want to be sure all correct (new at this). For a Savage Precision Target Action. Barrel Brand: Brux (cut-rifled) or Shilen...
What are the factors that affect the amount of light a sample absorbs?. In this exercise, the role of the cell path length is examined. The cell path length is the length of sample that the light passes through. The cell path length is represented by the symbol l and is typically measured in centimeters.. In the experiment presented below, you will perform a series of simulations in which all experimental parameters are the same except for the cell path length. Each simulation will be performed using a different cell path length to isolate the effect of the cell path length on the absorption of light.. Your goal is to answer the following questions ...
Optional: For thrown objects, Strength Modifier to Damage increments 5/10/15 feet of distance for every +1 adjustment. I.e. a character with a STR of 16 (+2) would add 10 to short range, 20 to medium range, and 30 to long range. For weaker characters with a negative modifier to Damage, reduce the range distances by one-half for every -1 adjustment. I.e. a character with a STR of 4 (-2) would be limited to 1/4 the distances listed, for example, a Tomahawk would be at 10/20/40 for S/M/L. In the case of rounding, if the STR score is on high side of the negative adjustment (i.e. a STR of 5 for the -2 adjustment), round up, if on the low side (i.e. a STR of 4 for the -2 adjustment), round down. (In the case of STR of 3, round up, anything below that, round down ...
Page contains details about example of electroluminescent emitter material . It has composition images, properties, Characterization methods, synthesis, applications and reference articles : nano.nature.com
A method previously developed for proton nonionizing energy loss (NIEL) calculations was extended to alpha particles. The alpha particle NIELs for represen
of the element. Thus thee flight of charged particles was often simply called alpha radiation. Radium emitted other forms of radiation but Martland calculated that more than 90 percent of the particles shooting out of radium came from alpha radiation. This wasnt all that bad: alpha particles were in their way rather wishy-washy bits of atomic energy. They could be stopped by a sheet of paper, a layer of clothing, even the upper layer of dead cells that overlay the skin. The other forms of radiation were actually more formidable. Beta radiation easily sliced through paper but could be stopped by a sheet of aluminum; the hurtle of gamma radiation could only be blocked by a dense material like lead.. But inside the body, as Martland would soon realize, alpha radiation created a precisely engineered internal poisoning. The radium dust noted by the Harvard team posed a definite hazard because it could be inhaled. But the reason that the hard-working dial painters were so much sicker than others in ...
The present invention is a tape product suitable for use in the protection of semiconductor devices from alpha-particles. The product comprises a heat resistant support film, a pressure sensitive adhesive layer on one side of the support film, a least one alpha-particle protector member formed of a plastic material capable of protecting the semiconductor device releasably supported on the pressure sensitive adhesive, and a layer of heat resistant adhesive bonded to the plastic material on its side lying opposite to the side bonded to the pressure sensitive adhesive. Preferably, a primer layer lies between the heat resistant support film on the pressure sensitive adhesive to insure that clean removal of the support film and pressure sensitive adhesive from the surface of the alpha-particle protector member. In order to aid in this removal the surface of the alpha-particle protector member facing the pressure sensitive layer is also coated with a release coating. The product is used by bonding the heat
article{82848f80-b339-48c7-9bcf-4d3e5bd07fbd, abstract = {Abstract Alpha-particle emitters, such as astatine-211 ((211)At), are generally considered suitable for the treatment of small cell clusters due to their short path length, while beta-particle emitters, for example, Lutetium-177 ((177)Lu), have a longer path length and are considered better for small, established tumors. A combination of such radionuclides may be successful in regimens of radioimmunotherapy. In this study, rats were treated by sequential administration of first a (177)Lu-labeled antibody, followed by a (211)At-labeled antibody 25 days later. Methods: Rats bearing solid colon carcinoma tumors were treated with 400 MBq/kg body weight (177)Lu-BR96. After 25 days, three groups of animals were given either 5 or 10 MBq/kg body weight of (211)At-BR96 simultaneously with or without a blocking agent reducing halogen uptake in normal tissues. Control animals were not given any (211)At-BR96. Myelotoxicity, body weight, tumor size, ...
Dr Christopher Parker, Institute of Cancer Research and Royal Marsden Hospital, Sutton, UK and colleagues did a study of 64 patients with HRPC. Radium 223 was chosen because it emits alpha radiation - which has higher energy and travels less distance than the beta radiation. Thus Parker and colleagues believe that alpha radiation will have a more pronounced localised effect on tumours.. The patients were randomly assigned to two groups. In the first, 33 received external-beam radiotherapy and up to four injections of radium-223. The other group received the same radiotherapy and placebo. Levels of bone alkaline phosphatase (bone-ALP) - considered a marker for progression of HRPC - decreased by 66% in the group receiving radium-223. The length of time for patients HRPC to progress - as assessed by each prostate-specific-antigen concentration - was much longer for those receiving radium 223 (26 weeks) compared to placebo (eight weeks). The median survival time for radium-223 patients was 41% ...
Gross alpha. Alpha particles are a type of ionizing radiation ejected by the nuclei of some unstable atoms. They are typically emitted from the elements uranium, radium, plutonium and thorium. The MCLG (federally recognized public health goal) for alpha particles is ZERO, however the legal limit (MCL) is set at 15 pCi/L (picocuries per liter). The EPA instructs water systems to "subtract" uranium from its "gross alpha" readings before they ae reported to you on an annual water quality report. This searchable database includes all results where Gross Alpha was reported in excess of 3.00 pCi/L. Gross beta. Beta particles are another form of ionizing radiation. They are smaller in size than alpha particles but can penetrate deeper into the body if consumed. The EPA says, "It is their excess energy, in the form of speed, that causes harm to living cells. When transferred, this energy can break chemical bonds and form ions." Some examples of the different types of elements that give off beta ...
It has been shown by Mott on the basis of the wave mechanics, that in the case of collisions between identical particles the scattered particles should interfere with the projected particles travelling in the same direction. When α-particles are scattered in helium, if the scattered α-particles and projected helium nuclei of similar velocity are identical in all respects, there will be interference between the two streams of particles. For collisions in which the particles act upon each other with forces varying as the inverse square of the distance between them, the interference results in the scattering intensity varying above and below the classical value and rising to double the classical numbers at 45º. At small angles the scattering predicted by the quantum mechanics does not differ greatly from that given by the classical theory. An experiment carried out by Chadwick showed quite definitely that for sufficiently slow α-particles the amount of scattering at 45º was double that of the ...
The nuclear track detector CR-39 is used extensively for charged particle diagnosis, in particular proton spectroscopy, at inertial confinement fusion facilities. These detectors can absorb x-ray doses from the experiments in the order of 1-100 Gy, the effects of which are not accounted for in the previous detector calibrations. X-ray dose absorbed in the CR-39 has previously been shown to affect the track size of alpha particles in the detector, primarily due to a measured reduction in the material bulk etch rate [Rojas-Herrera et al., Rev. Sci. Instrum. 86, 033501 (2015)]. Similar to the previous findings for alpha particles, protons with energies in the range 0.5-9.1 MeV are shown to produce tracks that are systematically smaller as a function of the absorbed x-ray dose in the CR-39. The reduction of track size due to x-ray dose is found to diminish with time between exposure and etching if the CR-39 is stored at ambient temperature, and complete recovery is observed after two weeks. The ...
(PRWEB) April 11, 2013 -- The Nuclear Medicine / Radiopharmaceuticals Market [SPECT/PET Radioisotopes (Technetium, F-18)], [Beta/Alpha Radiation Therapy (I131,
Everyone is exposed to uranium in food, air, and water as part of the natural environment. Most exposures do not warrant monitoring or treatment. Populations most heavily exposed to uranium are those employed in mining and milling operations, or in uranium enrichment and processing activities. Natural and depleted uranium are primarily chemical toxicants, with radiation playing a minor role or no role at all. Outcomes that may occur with uranium overexposure, based on both observed human effects and animal studies, include non-malignant respiratory disease (fibrosis, emphysema) and nephrotoxicity. Nephrotoxicity should reverse as overexposure ceases. Alpha radiation (such as that from uranium) is classified as a human carcinogen. However, human studies have not found elevated rates of cancer from uranium exposure, and high-dose animal studies have not found cancer following inhalation, oral, or dermal exposure to uranium.
Fortunately, most of the exposures we will be referring to in the study of hormesis are gamma and X-rays where Q is equal to one, allowing rads and rems to be used interchangeably. (Your radiologist, dental hygienist, and others working with X-rays will usually talk in terms of rads or millirads - but these are the same as rems and millirems, because it is the X-ray source that produces the radiation.) There is one other term with which you should have at least a vague familiarity - Linear Energy Transfer or LET. Beta, famma and X-rays are considered low LET radiation, which means they have a Q of one. High LET particles can have Qs up to 400. A typical alpha particle has a Q of four ...
131. After etching mica sheets with acid, Robert Gentry could see tiny pits where heavy, recoiling atoms had impacted after ejecting an alpha particle. He assumed those pits were made by recoiling polonium. Pit densities near isolated polonium halos were no greater than the pit densities far from halos. Therefore, he concluded that diffusion or slow movement did not transport polonium (an alpha emitter) into the halo centers. If that had happened, some polonium would have decayed as the polonium converged on those centers, so pit densities would have been greater near polonium halos. [See Robert V. Gentry, "Fossil Alpha-Recoil Analysis of Certain Variant Radioactive Halos," Science, Vol. 160, 14 June 1968, pp. 1228-1230.] This led to his eventual conclusion that the hundreds of millions of polonium isotopes must have been clustered at specific points since the instant of creation.. However, Gentry overlooked the powerful positive electrical charges at certain impact points and the rapid ...
Cell, Cells, Human, Clones, Nanoparticles, Lung, Alpha Particles, Energy Transfer, Hypersensitivity, Linear Energy Transfer, Protons, Survival, Transfer, Patients, T Cells, Tgf-beta, Cancer, Death, Lead, Treatment
Summary Orbis Research adds New Report Global Alpha Emitters Market-Growth, Trends and Forecasts (2017-2022) Description The Global Market for Alpha Emitt
For many years scientists had noticed that in Mendeleev published periodic table was a space underneath iodine known theoretically as eka-iodine but no one could identified in nature this element. In 1940, finally, the element was detected and produced by Americans physicts D.R Corson(1914-2012), K R Mackenzie (1912-2002), E Segre (1905-1989) in California by bombarding bismuth-209 with alpha particles in a cyclotron ...
Cell death is a crucial endpoint in radiation damage, and many theoretical models have been proposed; in this work, a mechanism-based, two-parameter model based on the link between cell death and chromosome aberrations was developed. More specifically, dicentrics, rings and large deletions were assumed to lead to clonogenic inactivation; furthermore, it was assumed that chromosome aberrations derive from µm-scale mis-rejoining of chromatin fragments, which in turn originate from "dirty" DNA double-strand breaks (called "Cluster Lesions", or CLs). The threshold distance for chromatin fragment rejoining and the average number of CLs per Gy and per cell are the only two (semi-free) model parameters. The model, which was "translated" into a Monte Carlo code called BIANCA (BIophysical ANalysis of Cell death and chromosome Aberrations) simulating survival curves for different radiation types, was tested against experimental data on V79 and AG1522 cells exposed to photons, protons, alpha particles and ...
In 1931 Walther Bothe and Herbert Becker in Germany found that if the very energetic alpha particles emitted from polonium fell on certain light elements, specifically beryllium, boron, or lithium, an unusually penetrating radiation was produced. At first this radiation was thought to be gamma radiation, although it was more penetrating than any gamma rays known, and the details of experimental results were very difficult to interpret on this basis. The next important contribution was reported in 1932 by Irène Joliot-Curie and Frédéric Joliot in Paris. They showed that if this unknown radiation fell on paraffin, or any other hydrogen-containing compound, it ejected protons of very high energy. This was not in itself inconsistent with the assumed gamma ray nature of the new radiation, but detailed quantitative analysis of the data became increasingly difficult to reconcile with such a hypothesis.. In 1932, James Chadwick performed a series of experiments at the University of Manchester, ...
Subatomic particles are important in all electronic, optical, and nuclear technologies. Cathode-ray tubes, for example, use beams of electrons to create the pictures. A television antenna first picks up the television signal-a series of radio-frequency photons-which is then processed electronically and used to control an electron gun. An electron gun shoots a beam of electrons which is steered by magnets and hits the coated inner surface of the picture tube. When electrons hit this surface, it lights up, creating the picture as the electron beam is steered rapidly across it. A common type of smoke detector that uses subatomic particles is an ionization smoke detector; in an ionization smoke detector, alpha particles ionize (strip electrons from) air molecules. These ionized air molecules cause electric current to flow in the detector. If there is a fire, other particles enter the detector and interfere with the flow of the electric current, and this makes the alarm go off. Proton beams are used ...
highly penetrating ionizing radiation of extraterrestrial origin; consisting chiefly of protons and alpha particles; collision with atmospheric particles results in rays and particles of many kinds. ...
Accelerated ions: protons, deuterons and alpha particles with maximum energy 13MeV/amu and fast neutrons irradiation with maximum fluxes 1011n/cm2* ...
This invention provides practical methods to make a DRAM fully compatible with existing SRAM products. This is accomplished by design and manufacture methods according to the invention, which includes a method to reduce standby power of reference voltage generators and a method to avoid the alpha particle problem using a novel error correction code (ECC) mechanism. The reference voltage generator of the present invention can adjust the values of output voltage and driving power separately following simple procedures. It has very strong driving power to maintain the reference voltage, which is necessary to support high-speed operation of memory devices of the present invention. In the mean time, its standby power can be reduced by orders of magnitudes using simple control mechanism, which is necessary to make our memory device compatible with the properties of existing SRAM products. There is no need to use feedback circuits or operation amplifiers, so the circuit is extremely stable and reliable. It is
The problem with the book is that it is really two books. Woit I - a brief history of particle physics - takes up the first 146 pages. Strings first appear on, wait for it, page 152, when we embark on the Great String Massacre of Woit II. Here the book finally gets into its stride, and becomes quite entertaining. But to get that point means traversing the long, rambling and inaccurate Woit I, and many readers will jump off before getting to the destination. This reviewer nearly did... This mayhem is not helped by errors and deficiencies: Ernest Rutherford discovered the nucleus at Manchester, not Cambridge, and using alpha particles (as stated correctly on page 19) not electrons (page 87)... I could go on. Emerging from the fog of Woit I is the saintly figure of Hermann Weyl, who single-handedly did much to improve the mathematical footing of physics in the early 20th century. Indeed, aside from damning string theory, Woits major theme is how physics and mathematics are intertwined ...
Atomic theory, ancient philosophical speculation that all things can be accounted for by innumerable combinations of hard, small, indivisible particles (called atoms) of various sizes but of the same basic material; or the modern scientific theory of matter according to which the chemical elements that combine to form the great variety of substances consist themselves of aggregations of similar subunits (atoms) possessing nuclear and electron substructure characteristic of each element. The ancient atomic theory was proposed in the 5th century bc by the Greek philosophers Leucippus and Democritus and was revived in the 1st century bc by the Roman philosopher and poet Lucretius. The modern atomic theory, which has undergone continuous refinement, began to flourish at the beginning of the 19th century with the work of the English chemist John Dalton. The experiments of the British physicist Ernest Rutherford in the early 20th century on the scattering of alpha particles from a thin gold foil ...
Radium-223, an alpha particle given intravenously, has been shown to improve overall survival in men with castrate-resistant prostate cancer (CRPC), with a 30% risk reduction of death (HR = 0.695, P = 0.00185). 1
b) Development of new techniques for environmental microdosimetry applicable to luminescence dating and for thick-source alpha counting determination of U and Th content by using solid state phosphors and detectors (TL, PIPS, etc). Recently the potentials of thick-source alpha particle spectroscopy for the dating of speleothems and ancient metals are studied ...
JETP Letters -- July 25, 1997 Volume 66, Issue 2, pp. 75-131 The contribution of the (t(tau) + N) component to the alpha-particle wave function from data on the reactions p(alpha,pp)t and p(alpha,pn)tau at incident alpha-particle momentum 5 GeV/c M. V. Chadeyeva, V. E. Grechko, V. V. Solovev, and V. F. Turov Full Text: PDF (133 kB) How can we study the halo momentum distribution in exotic nuclei? G. D. Alkhazov Full Text: PDF (61 kB) Measurement of the 45Ca beta spectrum in search of deviations from the theoretical shape A. V. Derbin, A. I. Egorov, S. V. Bakhlanov, and V. N. Muratova Full Text: PDF (77 kB) Liouville theory on a ZN Riemann surface S. A. Apikyan Full Text: PDF (111 kB) Shock wave structure in dense gases V. V. Zhakhovskii, K. Nishihara, and S. I. Anisimov Full Text: PDF (97 kB) Observation of the two-photon photoelectric effect in low-intensity optical fields during photostimulated fractal aggregation of colloidal silver S. V. Karpov, A. K. Popov, and V. V. Slabko Full Text: PDF ...
1. Bergers G, Benjamin LE. Tumorigenesis and the angiogenic switch. Nat Rev Cancer. 2003;3:401-10 2. Carmeliet P, Jain RK. Angiogenesis in cancer and other diseases. Nature. 2000;407:249 3. Sharma RA, Harris AL, Dalgleish AG, Steward WP, OByrne KJ. Angiogenesis as a biomarker and target in cancer chemoprevention. Lancet Oncol. 2001;2:726-32 4. Folkman J. Angiogenesis in cancer, vascular, rheumatoid and other disease. Nat Med. 1995;1:27-31 5. Cai W, Niu G, Chen X. Imaging of integrins as biomarkers for tumor angiogenesis. Curr Pharm Des. 2008;14:2943-73 6. Hynes RO. Integrins: bidirectional, allosteric signaling machines. Cell. 2002;110:673-87 7. Cai W, Wu Y, Chen K, Cao Q, Tice DA, Chen X. In vitro and in vivo characterization of 64Cu-labeled Abegrin, a humanized monoclonal antibody against integrin αvβ3. Cancer Res. 2006;66:9673-81 8. Cooper CR, Chay CH, Pienta KJ. The role of αvβ3 in prostate cancer progression. Neoplasia. 2002;4:191-4 9. Hood JD, Cheresh DA. Role of integrins in cell ...
Analysis of low moisture solid matrix samples by thermally extracting the volatile and semi-volatile organics directly from the solid matrix without the use of solvents or other sample preparation.
Analysis of low moisture solid matrix samples by thermally extracting the volatile and semi-volatile organics directly from the solid matrix without the use of solvents or other sample preparation.
More detail on the films 30 May 2005. Attending a workout in Steves area would be way out of my budget right now, as I live in Nevada, USA, and money is never easy to come by, plus the dollar grows weaker every day. However, I plan to order a few of his DVDs in the next month or two, but I have some questions.. Whats the difference between NHB 1 (Stance, Positioning, Footwork and Striking while Standing) and NHB 1A? It sounds like NHB 1 is more in-depth as far as head movement, stance, & short range striking goes, is that correct?. Also, what is on the Fight Training Methods, Principles and Concepts dvd?. What specifically does he teach on each of the above DVDs in terms of drills, footwork, mechanics, mindset, positioning, transitions, and explosiveness, etc? Im particularly interested in his ideas of being more effective during the transitions between moves or positions. I want to have more striking power at short ranges, and in all positions. I want to be more explosive at closing the ...
On Thu, 8 Sep 2005, Chuck Lever wrote: , , , , Btw, in the sparse project, we have this really smart pointer list data , , structure, which is extremely space- and time-efficient. It ends up , , _looking_ like a linked list, but it batches things up in hunks of 29 , , entries (29 pointers plus overhead gives you blocks of 32 longwords, which , , is the allocation size) and thus gives basically a cache-friendly , , doubly-linked list. It knows how to do insertions, traversals etc very , , efficiently. , , , , Any interest? , , im not married to splay trees. i think we should explore several , different data structures before picking one, and this one sounds , reasonable to try ...
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Your inner circle is affecting your health, whether you realize it or not. Think twice about going out with your crew to a "bottomless mimosa" brunch. All those extra calories add up and wont help you lose weight. Besides that, alcohol is a poison that your organs have to work overtime to filter out, leaving you feeling drained the next day. Or if you and your friends like to spend late nights together, youre likely cutting into your rest and recovery time. But your sleep is vital for getting stronger and losing weight. That doesnt mean you need to kiss your friends goodbye, it just means that youll need to be more strategic about spending time with them.. Read more: 8 Surprising Ways Your Social Life Impacts Your Health. ...
4:00] Misconception #2 -- Pluto-kun addresses the fear that plutonium is deadly and causes cancer. Plutoniums danger to the human body stems from the alpha radiation it emits. Because alpha radiation is relatively weak, it does not penetrate the skin, and plutonium is not absorbed into the body if it comes into contact with skin. He explains that you would not die instantly if you were to drink plutonium. If swallowed, the vast majority simply passes through the digestive tract without being absorbed. If it enters the blood stream (through a cut, for example) it cannot be removed easily from the body. It accumulates in the lymph nodes before ending up in the bones or liver, where it continues emitting alpha radiation. Plutonium can also get into the liver or bones if it is inhaled into the lungs. It is important not to breathe it in or allow it to enter the blood stream.. [6:00] No human is ever known to have died because of inhaling or ingesting plutonium. [7:00] Pluto-kun explains what would ...
4:00] Misconception #2 -- Pluto-kun addresses the fear that plutonium is deadly and causes cancer. Plutoniums danger to the human body stems from the alpha radiation it emits. Because alpha radiation is relatively weak, it does not penetrate the skin, and plutonium is not absorbed into the body if it comes into contact with skin. He explains that you would not die instantly if you were to drink plutonium. If swallowed, the vast majority simply passes through the digestive tract without being absorbed. If it enters the blood stream (through a cut, for example) it cannot be removed easily from the body. It accumulates in the lymph nodes before ending up in the bones or liver, where it continues emitting alpha radiation. Plutonium can also get into the liver or bones if it is inhaled into the lungs. It is important not to breathe it in or allow it to enter the blood stream.. [6:00] No human is ever known to have died because of inhaling or ingesting plutonium. [7:00] Pluto-kun explains what would ...
If you have a question about this talk, please contact Ian Farnan.. Phosphates are known to exhibit superior resistance to radiation damage, as evidenced by natural phosphate minerals that are minimally damaged despite containing alpha-emitting actinides for hundreds of millions of years. This study looks to investigate radiation damage in xenotime (YPO4) and zircon (ZrSiO4). Radiation damage occurs by two processes: the recoil of the heavy nucleus (70-100 keV) and the alpha particle itself (4.5-5.5 MeV), which loses energy primarily by ionizations but causes several hundred atomic displacements near the end of its path. Here we present results of Pu doping into xenotime, with insight into solid solubility and response to radiation damage compared to previous results for zircon. We also separate damage due to alpha particles from damage due to the heavy nucleus recoil and compare to Pu-doped studies.. For solid solubility and accelerated ageing studies, 239 and 238Pu-doped xenotime samples were ...
Monoclonal antibodies can transport and deliver radioactive elements capable of releasing sufficient amounts of energy to destroy tumor cells. In this clinical trial, we will study alpha particle radio immunotherapy using lead-212 (²¹²Pb), an isotope with a short path length targeted to malignant cells by the trastuzumab antibody, as a potential treatment for metastatic diseases.. This Phase I trial is designed to determine the toxicity profile of ²¹²Pb-TCMC-Trastuzumab, its dose-limiting toxicities, and its anti-tumor effects in patients with HER-2 positive intraperitoneal cancers. ...
Slide 8: What are three types of nuclear radiation?. Alpha decay. Beta decay. Gamma decay. Slide 9: What is an alpha particle?. An alpha particle is a postively charged particle that is emited from the nucleus of an atom.. Slide 10: What is a beta particle?. A beta particle is a high energy electron that is emiited from the nucleus of an atom. Slide 11: What is gamma radiation. Gamma radiation is high energy electromagnetic radiation.. What to do now?. 1. Animate the points in your slide 2. Answer the Summary Questions on a slide. ...
In 1907 Ernest Rutherford published "Radiation of the α Particle from Radium in passing through Matter."[3] Hans Geiger expanded on this work in a communication to the Royal Society[4] with experiments he and Rutherford had done, passing α particles through air, aluminum foil and gold leaf. More work was published in 1909 by Geiger and Marsden[5] and further greatly expanded work was published in 1910 by Geiger.[6] In 1911-1912 Rutherford went before the Royal Society to explain the experiments and propound the new theory of the atomic nucleus as we now understand it. The key experiment behind this announcement happened in 1910 at the University of Manchester, as Ernest Rutherfords team performed a remarkable experiment in which Hans Geiger and Ernest Marsden under his supervision fired alpha particles (helium nuclei) at a thin film of gold foil. The plum pudding model predicted that the alpha particles should come out of the foil with their trajectories being at most slightly bent. ...
2000 (English)In: Comprehensive Summaries of Uppsala Dissertations from the Faculty of Medicine, Vol. 960Book (Other scientific) ...
The purpose of this study is to find a safe dose of actinium-225 when it is labeled to HuM195. This will be done with a phase I trial, in which a preset schedule of doses gets more powerful for each new group of patients as the trial progresses. If too many serious side effects are seen with a certain dose, no one will be treated with a higher dose, and some additional patients may be treated with a lower dose to make sure that this dose is safe. The starting dose of actinium-225 in this study is less than doses that are known to be safe in animals.. Antibodies are proteins that are produced by the immune system and help the body to fight foreign substances, such as bacteria or viruses. HuM195 was made by putting human leukemia cells into mice. Most of the mouse parts of this antibody were replaced with human parts. Only the part of the antibody that binds to the leukemia cells was kept from the mouse. HuM195 attaches to leukemia cells but does not attach to most normal cells. It can kill ...
The use of radioisotopes (radionuclide) in clinical practice is well established. Radioisotopes emit energy from the nucleus and generate ionized atoms and free radicals to induce single strand cleavages in DNA. Radioisotopes applied in the clinical oncology include beta-emitters, like 186Re, 188Re, 166Ho, 89Sr, 32P, and 90Y, as well as alpha-emitters, like 225Ac, 211At, and 213Bi (Hamoudeh et al. 2008). When used in vivo, beta-emitters have profound tissue penetration (20-130 mm) but low linear energy transfer, whereas alpha-emitters have limited penetration (50-80 μm) but a short half-life and the ability to inflict more damage to the cells.. There are different mechanisms of how the human body eliminates radioisotopes. Many of the radioisotopes undergo rapid clearance by the kidney. In particular, renal clearance is size dependent, for which size smaller than 5 nm will be excreted rapidly. Radioisotopes as small molecules suffer short circulation time in blood and are unable to achieve ...
X-ray Research on Short-lived Isotope Provides New Possibilities for Cancer Treatment - Scientists Improve Understanding of Mysterious Actinium. Excerpted from August 22, 2016 SLAC News Feature. A recent paper published in Nature Communications reveals insights about the element actinium that could support new classes of anticancer drugs. A team of researchers from the Los Alamos National Laboratory has conducted x-ray absorption fine structure experiments on SSRLs Beam Line 11-2 to characterize the molecular and electronic structure, including chemical bonds in actinium compounds.. Using synchrotron-based tools to obtain a better understanding of the structure of Actinium-225, for example, looks promising. It has a relatively short half-life (10 days) and emits powerful alpha particles as it decays to stable bismuth. This makes it a perfect candidate for a novel cancer treatment technique called targeted-alpha therapy, where alpha emissions from radioisotopes destroy malignant cells while ...
A carcinogen is any substance, radionuclide, or radiation that promotes carcinogenesis, the formation of cancer. This may be due to the ability to damage the genome or to the disruption of cellular metabolic processes. Several radioactive substances are considered carcinogens, but their carcinogenic activity is attributed to the radiation, for example gamma rays and alpha particles, which they emit. Common examples of non-radioactive carcinogens are inhaled asbestos, certain dioxins, and tobacco smoke. Although the public generally associates carcinogenicity with synthetic chemicals, it is equally likely to arise in both natural and synthetic substances.[1] Carcinogens are not necessarily immediately toxic; thus, their effect can be insidious.. Cancer is any disease in which normal cells are damaged and do not undergo programmed cell death as fast as they divide via mitosis. Carcinogens may increase the risk of cancer by altering cellular metabolism or damaging DNA directly in cells, which ...
In biological dosimetry it is typically assumed that the number of chromosomal aberrations produced in a blood cell is Poisson distributed, whose intensity is a quadratic function of the absorbed dose. Dose-response curves are calculated from cytogenetic laboratory experiments where blood samples are exposed to different doses, simulating whole body homogeneous irradiations. This classical Poisson assumption is not supported in a lot of irradiation scenarios, for instance for high linear energy transfer, partial body or gradient irradiations. These situations lead to compound Poisson, zero-inflated Poisson and Poisson finite mixture models, among others ...
Preface XVII. 1 Structure of Atoms 1. 1.1 Atom Constituents 2. 1.2 Structure, Identity, and Stability of Atoms 5. 1.3 Chart of the Nuclides 6. 1.4 Nuclear Models 8. 2 Atoms and Energy 11. 2.1 Atom Measures 12. 2.2 Energy Concepts for Atoms 14. 3 Radioactive Transformation 21. 3.1 Processes of Radioactive Transformation 21. 3.2 Decay Schemes 54. 3.3 Rate of Radioactive Transformation 57. 3.4 Radioactivity Calculations 65. 3.5 Activity-mass Relationships 70. 3.6 Radioactive Series Transformation 73. 3.7 Radioactive Equilibrium 77. 3.8 Total Number of Transformations (Uses of s and kEff) 84. 3.9 Discovery of the Neutrino 86. 4 Interactions 91. 4.1 Production of X-rays 91. 4.2 Characteristic X-rays 93. 4.3 Nuclear Interactions 98. 4.4 Alpha Particle Interactions 104. 4.5 Transmutation by Protons and Deuterons 106. 4.6 Neutron Interactions 114. 4.7 Activation Product Calculations 117. 4.8 Medical Isotope Reactions 126. 4.9 Transuranium Elements 128. 4.10 Photon Interactions 130. 4.11 Fission and ...
Chemoradiotherapy comparing different types of radiation beams: The Radiation Therapy Oncology Group randomized 49 evaluable patients to receive radiation treatment that was radiotherapeutically equivalent to 64 Gy of photon radiation treatment. Either pure photons or neutrons, or a combination (mixed-beam irradiation) of both, were used (Table 1[D]). Neutron irradiation was postulated to have several advantages due to its high linear energy transfer properties and, thus, the possibility of improved local control.. The GITSG compared 5-FU given with 60 Gy of radiation in a double-split course, with doxorubicin 15 mg/m2 on day 1 followed by 10 mg/m2 weekly given with 40 Gy of radiation administered in a continuous course. After radiation, the doxorubicin was continued on a three to four week schedule until the maximum safe dose had been given, at which time patients were switched to 5-FU. A total of 143 patients were analyzed, and there was no significant survival difference. However, toxicity ...
A stack of natural samarium was bombarded with 87 MeV alpha particles. Cumulative cross sections for the production of153Gd,151Gd,149Gd,147Gd,146Gd have been studied using gamma-ray spectroscopy.
Class: Radiopharmaceutical. Generic Name: Radium Ra 223 dichloride (RAY-dee-um Ra 223 dye-KLOR-ide). Trade Name: Xofigo®. For which conditions is this drug approved? Radium Ra 223 dichloride is indicated for the treatment of patients with castration-resistant prostate cancer, symptomatic bone metastases, and no known visceral metastatic disease.. What is the mechanism of action? The active component of radium Ra 223 dichloride is the alpha particle-emitting isotope radium-223 (as radium Ra 223 dichloride), which mimics calcium and forms complexes with the bone mineral hydroxyapatite at areas of increased bone turnover, such as bone metastases The high linear energy transfer of alpha emitters (80 keV/micrometer) leads to a high frequency of double-strand DNA breaks in adjacent cells, resulting in an anti-tumor effect on bone metastases. The alpha particle range from radium-223 dichloride is less than 100 micrometers (less than 10 cell diameters), which limits damage to the surrounding normal ...
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Radon is a radioactive element. The nucleus of radioactive elements is instable and decays. During this decay radiation is formed.. The half-life of radon is 3.8 days. This means that - irrespective of the radon concentration level - half of the amount of radon has decayed into its decay products within four days.. Short-lived radon decay products are isotopes of polonium, bismuth, and lead. These are also radioactive and have a very short half-life. Their nuclei decay within only a few minutes, emitting alpha radiation that may damage human tissue.. The radioactive radon decay products accumulate in aerosols (very fine particles in the air), which are inhaled. When the radon decay products decay in the lung, they emanate radiation. This radiation can damage cells in the lung tissue, thus causing lung cancer.. ...
In a nuclear weapon, polonium provides a catalyst for the reaction that detonates the plutonium. The plutonium it self will not initiate the chain reaction necessary to achieve detonation, and requires a neutron source that gives off neutrons faster than the plutonium. In earlier nuclear weapons, the initiator was a beryllium metal and polonium mixture where the polonium gave off alpha particles that irradiated the beryllium. Irradiated beryllium gives off the necessary neutrons to initiate the chain reaction in the plutonium.. The Polonium-210 operations were terminated at Mound in June 1972.. POST POLONIUM ACTIVITIES: RADIUM AND ACTINIUM- Because of poloniums relative short half-life, the AEC realized it would be necessary to frequently change the polonium in the initiators. Because of this, the AEC began exploring alternate fuels for the initiator. One element of interest was actinium-227. In response to this interest, the AEC charged Mound with activities related to the development and ...
What is background radiation?. Ionising radiation always present in the environment. Why does background radiation not cause harm?. The levels are constant and are too low to be harmful and are naturally occuring mostly. Main contributors to background radiation?. Cosmic rays from the sun, decay of rocks, radon gas from the ground. Small contributors to background radiation?. Man made sources like radioactive waste from nuclear power stations and hospitals, and from smoke alarms. How much does human activity contribute to background radiation?. Less than 1%. What is the most common radioisotope used in smoke alarms?. Americium 241. What type of radiation do smoke alarms give out?. Alpha. How does a smoke alarm work?. The alpha particles ionise the molecules of the air forming ions and electrons which are attracted to a pair of charged plates as shown in the picture below. When the ions and electrons hit the plates they provide a small amount of electricity (a small current). This current stays ...
Neutron radiation is a kind of ionizing radiation that consists of free neutrons. A result of nuclear fission or nuclear fusion, it consists of the release of free neutrons from atoms, and these free neutrons react with nuclei of other atoms to form new isotopes, which, in turn, may produce radiation. Free neutrons are unstable, decaying into a proton, an electron, and an anti-electron-neutrino with a mean lifetime of 887 seconds (about 15 minutes). Neutrons may be emitted from nuclear fusion or nuclear fission, or from any number of different nuclear reactions such as from radioactive decay or reactions from particle interactions (such as from cosmic rays or particle accelerators). Large neutron sources are rare, and are usually limited to large-sized devices like nuclear reactors or particle accelerators (such as the Spallation Neutron Source). Neutron radiation was discovered as a result of observing a beryllium nucleus reacting with an alpha particle thus transforming into a carbon nucleus ...
Neutron activation is the process in which neutron radiation induces radioactivity in materials, and occurs when atomic nuclei capture free neutrons, becoming heavier and entering excited states. The excited nucleus often decays immediately by emitting gamma rays, or particles such as beta particles, alpha particles, fission products, and neutrons (in nuclear fission). Thus, the process of neutron capture, even after any intermediate decay, often results in the formation of an unstable activation product. Such radioactive nuclei can exhibit half-lives ranging from small fractions of a second to many years.. Neutron activation is the only common way that a stable material can be induced into becoming intrinsically radioactive. All naturally occurring materials, including air, water, and soil, can be induced (activated) by neutron capture into some amount of radioactivity in varying degrees, as a result of production of neutron-rich radioisotopes. Some atoms require more than one neutron to become ...

Periodic Table of Elements: Astatine - At (EnvironmentalChemistry.com)Periodic Table of Elements: Astatine - At (EnvironmentalChemistry.com)

Produced by bombarding bismuth with alpha particles. Total world production to date estimated to be around 50 nanograms (50E-9 ...
more infohttps://environmentalchemistry.com/yogi/periodic/At.html

ATSDR - Public Health Statement: AmericiumATSDR - Public Health Statement: Americium

... sometimes referred to as alpha radiation) and turn into neptunium 237 (237Np) and neptunium 239 (239Np), ... sup>241Am and 243Am give off alpha particles ( ... Alpha particles are relatively high energy particles, but ... 241Am and 243Am give off alpha particles (sometimes referred to as alpha radiation) and change into neptunium 237 (237Np) and ... Since alpha particles do not penetrate the skin and the gamma rays released from americium sources are relatively low in energy ...
more infohttps://www.atsdr.cdc.gov/phs/phs.asp?id=809&tid=158

Radium | InjuryBoard.comRadium | InjuryBoard.com

Alpha particles can travel only a short distance and cannot travel through your skin. Beta particles can penetrate through your ... During the decay process, alpha, beta, and gamma radiation are released. ...
more infohttp://wiki.legalexaminer.com/topic/radium.aspx

Killing Lone Cancer Cells Using Alpha-Particles - TFOTKilling Lone Cancer Cells Using Alpha-Particles - TFOT

... there is no FDA-approved alpha-particle cancer treatment. An Alpha-particle is a particle composed of two protons and two ... The radiation (the alpha-particles) is produced from the rare element Astatine. The benefit of using alpha-particles rather ... It takes thousands of beta-particles to kill a single cell, while a direct hit of just one alpha-particle is sufficient. Alpha- ... Alpha-particles have low penetration abilities, but their impact is much stronger than that of beta particles. In fact, the ...
more infohttps://thefutureofthings.com/3182-killing-lone-cancer-cells-using-alpha-particles/

StateMaster - Encyclopedia: Alpha particleStateMaster - Encyclopedia: Alpha particle

Alpha particle - Wikipedia, the free encyclopedia (769 words). Alpha particles or alpha rays (named after the first letter in ... The energy of alpha particles varies, with higher energy alpha particles being emitted from larger nuclei, but most alpha ... The alpha particle mass is 6.644656×10-27 kg, which is equivalent to the energy of 3.72738 GeV. The charge of an alpha particle ... The alpha particles were detected by a zinc sulfide screen, which emits a flash of light upon an alpha particle collision. ...
more infohttp://www.statemaster.com/encyclopedia/Alpha-particle

What Is an Alpha Particle Made Of? | Reference.comWhat Is an Alpha Particle Made Of? | Reference.com

An alpha particle is common in the field of nuclear physics because it is one of the three particles emitted during radioactive ... An alpha particle is made up of two protons and two neutrons. ... An alpha particle is made up of two protons and two neutrons. ... Alpha particles became well-known thanks to Ernest Rutherfords use of alpha particles as projectiles with gold foil serving as ... An alpha particle is common in the field of nuclear physics because it is one of the three particles emitted during radioactive ...
more infohttps://www.reference.com/science/alpha-particle-made-41a666e598588fd2

High resolution alpha-particle-sp... preview & related info | MendeleyHigh resolution alpha-particle-sp... preview & related info | Mendeley

In the α-particle spectrometric technique for radium isotope analysis, the effects of the barium carrier thickness and pore ... High resolution alpha-particle-spectrometry for radium analysis-the effects of sample thickness and filter pore size. *Lim T ... Lim, T. P., Dave, N. K., & Cloutier, N. R. (1989). High resolution alpha-particle-spectrometry for radium analysis-the effects ... In the α-particle spectrometric technique for radium isotope analysis, the effects of the barium carrier thickness and pore ...
more infohttps://www.mendeley.com/papers/high-resolution-alphaparticlespectrometry-radium-analysisthe-effects-sample-thickness-filter-pore-si/

Patent US4761335 - Alpha-particle protection of semiconductor devices - Google PatentsPatent US4761335 - Alpha-particle protection of semiconductor devices - Google Patents

In order to aid in this removal the surface of the alpha-particle protector member facing the pressure sensitive layer is also ... a least one alpha-particle protector member formed of a plastic material capable of protecting the semiconductor device ... to insure that clean removal of the support film and pressure sensitive adhesive from the surface of the alpha-particle ... The present invention is a tape product suitable for use in the protection of semiconductor devices from alpha-particles. The ...
more infohttp://www.google.com/patents/US4761335?dq=mezick

Alpha particles | definition of alpha particles by Medical dictionaryAlpha particles | definition of alpha particles by Medical dictionary

... alpha particles explanation free. What is alpha particles? Meaning of alpha particles medical term. What does alpha particles ... Looking for online definition of alpha particles in the Medical Dictionary? ... alpha particles. , alpha rays. Radioactive, positively charged particles, equivalent to a helium nucleus (two protons and two ... Alpha particles , definition of alpha particles by Medical dictionary https://medical-dictionary.thefreedictionary.com/alpha+ ...
more infohttps://medical-dictionary.thefreedictionary.com/Alpha+particles

Microturbulent transport of non-Maxwellian alpha particlesMicroturbulent transport of non-Maxwellian alpha particles

Newly-born high-energy alpha particles are not expected to respond to turbulence as strongly as alpha particles that have ... The alpha particle distribution in collisional equilibrium forms a non-Maxwellian tail which spans orders of magnitude in ... Whether a plasma can reach a burning state requires knowledge of the transport of alpha particles, and turbulence is one such ... A new code was written for this purpose and corrections to the global alpha particle heating profile due to microturbulence in ...
more infohttps://drum.lib.umd.edu/handle/1903/17302

Factors underlying the cell growth-related bystander responses to alpha particles.Factors underlying the cell growth-related bystander responses to alpha particles.

We report that exposure of normal human lung fibroblasts to a low dose of alpha particles like those emitted by radon/radon ... Alpha Particles*. Cell Division / radiation effects. Cells, Cultured. Cyclin-Dependent Kinase Inhibitor p21. Cyclins / ... We report that exposure of normal human lung fibroblasts to a low dose of alpha particles like those emitted by radon/radon ... Our results indicate that alpha particle-associated increases in cell growth correlate with intracellular increases in ROS ...
more infohttp://www.biomedsearch.com/nih/Factors-underlying-cell-growth-related/10728689.html

Alpha particle - WikipediaAlpha particle - Wikipedia

... being an alpha particle. Such alpha particles are termed "long range alphas" since at their typical energy of 16 MeV, they are ... see alpha decay). The energy of alpha particles emitted varies, with higher energy alpha particles being emitted from larger ... Alpha particles are named after the first letter in the Greek alphabet, α. The symbol for the alpha particle is α or α2+. ... The alpha particles were detected by a zinc sulfide screen, which emits a flash of light upon an alpha particle collision. ...
more infohttps://en.wikipedia.org/wiki/Alpha_particle

Alpha-particle protection of semiconductor devices - Patent # 4761335 - PatentGeniusAlpha-particle protection of semiconductor devices - Patent # 4761335 - PatentGenius

... alpha-particle protector member. In order to aid in this removal the surface of the alpha-particle protector member facing the ... a least one alpha-particle protector member formed of a plastic material capable of protecting the semiconductor device ... of semiconductor devices from alpha-particles. The product comprises a heat resistant support film, a pressure sensitive ... These factors make VLSI die more sensitive to static electricity or to alpha-particles. Alpha-particles are believed to ...
more infohttp://www.patentgenius.com/patent/4761335.html

Alpha-particle spectroscopy - WikipediaAlpha-particle spectroscopy - Wikipedia

Energetics of alpha decay: The alpha particle, or 4He nucleus, is an especially strongly bound particle. This combined with the ... many alpha emitters is to use alpha-particle spectroscopy. For methods of gamma rays and beta particles, please see gamma ... will be divided between the alpha-particle and the heavy recoiling daughter so that the kinetic energy of the alpha particle ... This is because some of the energy of the alpha particles is lost during their movement through the layer of active material. ...
more infohttps://en.wikipedia.org/wiki/Alpha-particle_spectroscopy

Nuclear structure aspects of proton and alpha particle decayNuclear structure aspects of proton and alpha particle decay

1. Alpha-decay hindrance factors: A probe of mean-field wave function. Open this publication in new window or tab ,,Alpha-decay ... 3. Fine structure in the alpha decay of Po-188,Po-192. Open this publication in new window or tab ,,Fine structure in the alpha ... Nuclear structure aspects of proton and alpha particle decay. Karlgren, Daniel KTH, School of Engineering Sciences (SCI), ... All known cases of fine structure in the alpha decay of the even-even Po nuclei are reviewed. The reduced alpha-decay width ...
more infohttp://kth.diva-portal.org/smash/record.jsf?pid=diva2%3A10187

On the scattering of neutrons by alpha particles | Springer for Research & DevelopmentOn the scattering of neutrons by alpha particles | Springer for Research & Development

B. H. Bransden andJ. S. C. McKee:Phil. Mag.,45, 869 (1954);S. Hochberg, H. S. W. Massey andL. H. Underhill:Proc. Phys. Soc.,67 A, 987 (1954);S. Hochberg, H. S. W. Massey, H. Robertson andL. H. Underhill:Proc. Phys. Soc.,68 A, 746 (1955).CrossRefGoogle Scholar ...
more infohttps://rd.springer.com/article/10.1007/BF02855859

Alpha particle density and energy distributions in tandem mirrors using Monte-Carlo techniques - Digital LibraryAlpha particle density and energy distributions in tandem mirrors using Monte-Carlo techniques - Digital Library

Monte-Carlo techniques are used to determine the alpha radial birth position, the alpha particle position at a collision, and ... in which the alpha guiding center is followed between simulated collisions and Spitzers collision model is used for the alpha- ... The plasma is modeled as a hot reacting core, surrounded by a cold halo plasma (T approx.50 eV). Alpha orbits that intersect ... The uneven drag across the alpha orbit also produces an outward, radial, guiding center drift. This drag drift is dependent on ...
more infohttps://digital.library.unt.edu/ark:/67531/metadc1093733/

The process of ionization of argon by alpha-particles  - CaltechTHESISThe process of ionization of argon by alpha-particles - CaltechTHESIS

... alpha]-particles were the ionizing agent. Also it is known that an [alpha]-particle is much more effective as an ionizing agent ... alpha]-particles only. They selected helium as the gas with which to experiment. The range of the [alpha]-particles was varied ... We shall be concerned with ionization by the impact of positive ions and [alpha]-particles. Suppose the colliding particle has ... Alpha-particles are only a special type of positive ray so that it would be natural to look for these multiply charged ions ...
more infohttps://thesis.library.caltech.edu/4401/

Detection of Alpha Particles and Low Energy Gamma Rays by Thermo-Bonded Micromegas in Xenon Gas - IEEE Journals & MagazineDetection of Alpha Particles and Low Energy Gamma Rays by Thermo-Bonded Micromegas in Xenon Gas - IEEE Journals & Magazine

Micromegas is a type of micro-pattern gaseous detector currently under R&D for applications in rare event search experiments. Here we report the perfor
more infohttp://ieeexplore.ieee.org/document/6544301/?reload=true&arnumber=6544301

Alpha Particle Emission | Jim Hisert | Indium Corporation Blogs | Indium | Indium Corporation | Semiconductor Packaging |...Alpha Particle Emission | Jim Hisert | Indium Corporation Blogs | Indium | Indium Corporation | Semiconductor Packaging |...

Alpha particles are emitted from certain element isotopes, and can potentially change the binary output of a semiconductor from ... Alpha emission is measured in counts/(square centimeter x hour). This measurement refers to the amount of particles that are ... Alpha particles are emitted from certain element isotopes, and can potentially change the binary output of a semiconductor from ... Tomorrow I will describe how solder suppliers like Indium Corporation can help lower alpha particle emission within an ...
more infohttp://www.indium.com/blog/alpha-particle-emission.php

Characteristics of the spectra of protons and alpha particles in recurrent events at 1 Au  - CaltechAUTHORSCharacteristics of the spectra of protons and alpha particles in recurrent events at 1 Au - CaltechAUTHORS

The spectra of both protons and alpha particles (1 ≲ E ≲ 7 MeV/nucleon) during 31 recurrent particle streams are fit well by an ... Mewaldt, R. A. and Stone, E. C. and Vogt, R. E. (1979) Characteristics of the spectra of protons and alpha particles in ... Although the spectra show considerable temporal variation, the proton and alpha particle spectra are correlated such that the e ... Characteristics of the spectra of protons and alpha particles in recurrent events at 1 Au ...
more infohttps://authors.library.caltech.edu/43686/

The method of thermodynamic parameters calculation and its application on the study of protons and alpha particles behaviour in...The method of thermodynamic parameters calculation and its application on the study of protons and alpha particles behaviour in...

The paper deals with the behaviour of alpha particles and protons in the solar wind plasma near the Earths bow shock. It is ... Characteristic parameters of alpha particles and proton flows, as computed by this method, show that in the Earths bow shock ... The paper deals with the behaviour of alpha particles and protons in the solar wind plasma near the Earths bow shock. It is ... Solar Wind Plasma Parameter Alpha Particle Parameter Calculation Reliable Evaluation These keywords were added by machine and ...
more infohttps://link.springer.com/article/10.1007%2FBF01599038

Dose response relationships for chromosome aberrations induced by low doses of alpha-particle radiationDose response relationships for chromosome aberrations induced by low doses of alpha-particle radiation

... EJ Tawn and Hubert ... "Dose Response Relationships for Chromosome Aberrations Induced by Low Doses of Alpha-particle Radiation." Radiation Protection ... "Dose Response Relationships for Chromosome Aberrations Induced by Low Doses of Alpha-particle Radiation." RADIATION PROTECTION ... Tawn E, Thierens H. Dose response relationships for chromosome aberrations induced by low doses of alpha-particle radiation. ...
more infohttps://biblio.ugent.be/publication/879216

Alpha particle tracks including a collision with a massive nucleus (e.g. nitrogen or oxygen)Alpha particle tracks including a collision with a massive nucleus (e.g. nitrogen or oxygen)

Alpha particle tracks in wet nitrogen. One collided with a nitrogen nucleus and moved to the right. The recoiling nucleus made ... Alpha particle tracks including a collision with a massive nucleus (e.g. nitrogen or oxygen). ... Practical Physics » Apparatus » Alpha particle tracks including a collision with a massive nucleus (e.g. nitrogen or oxygen) ...
more infohttp://practicalphysics.org/alpha-particle-tracks-including-collision-massive-nucleus-eg-nitrogen-or-oxygen.html

Nanoconjugation of PSMA-Targeting Ligands Enhances Perinuclear Localization and Improves Efficacy of Delivered Alpha-Particle...Nanoconjugation of PSMA-Targeting Ligands Enhances Perinuclear Localization and Improves Efficacy of Delivered Alpha-Particle...

An alpha-particle emitting antibody ([213Bi]J591) for radioimmunotherapy of prostate cancer. Cancer Res 2000;60:6095-100. ... Calculations of cellular microdosimetry parameters for alpha particles and electrons. Appl Radiat Isot 2004;61:739-43. ... Vascular-targeted radioimmunotherapy with the alpha-particle emitter 211At. Radiat Res 2002;157:633-41. ... Nanoconjugation of PSMA-Targeting Ligands Enhances Perinuclear Localization and Improves Efficacy of Delivered Alpha-Particle ...
more infohttp://mct.aacrjournals.org/content/15/1/106
  • 241 Am and 243 Am give off alpha particles (sometimes referred to as alpha radiation) and change into neptunium 237 (237Np) and neptunium 239 (239Np), respectively. (cdc.gov)
  • For example, one of the heaviest naturally occurring isotopes, 238U (with a mass excess, Δ, of +47.3070 MeV) decays by alpha emission to 234Th (Δ = +40.612 MeV) giving a Q-value: Qα = 47.3070 - (40.612 + 2.4249) = 4.270 MeV Note that the decay energy will be divided between the alpha-particle and the heavy recoiling daughter so that the kinetic energy of the alpha particle will be slightly less. (wikipedia.org)
  • Using deformation values obtained from potential energy surface (PES) calculations as the only input, hindrance factors for the alpha decay of Rn and Po isotopes are calculated. (diva-portal.org)
  • Alpha particles are emitted from certain element isotopes, and can potentially change the binary output of a semiconductor from a 0 to a 1 or from a 1 to a 0. (indium.com)
  • The product comprises a heat resistant support film, a pressure sensitive adhesive layer on one side of the support film, a least one alpha-particle protector member formed of a plastic material capable of protecting the semiconductor device releasably supported on the pressure sensitive adhesive, and a layer of heat resistant adhesive bonded to the plastic material on its side lying opposite to the side bonded to the pressure sensitive adhesive. (google.com)
  • d) a layer of heat resistant adhesive bonded to the plastic material (c) on its side lying opposite to the side bonded to layer (b) to allow for bonding of the member (c) to the semiconductor device to be protected from the alpha-particles. (google.com)
  • Due to the imperfections of the liquid scintillation method (such as a failure for all the photons to be detected, cloudy or coloured samples can be difficult to count) and the fact that random quenching can reduce the number of photons generated per radioactive decay, it is possible to get a broadening of the alpha spectra obtained through liquid scintillation. (wikipedia.org)
  • While the HPRT locus was significantly more mutable in WTK1 as a function of α-particle versus X-ray dose, the TK locus was only slightly more sensitive to a-particle mutagenesis. (elsevier.com)
  • With the ability to run self-consistent simulations with a population of alpha particles, we can examine certain assumptions commonly made about alpha particles in the context of microturbulence. (umd.edu)
  • The calculated HF that emerge from these calculations render a different interpretation than the commonly assumed n-particle n-hole picture of the intruder states in the Pb region. (diva-portal.org)
  • In addition, the slowly growing TK mutants that constitute the majority of X-ray-induced TK mutants of TK6 were recovered in lower proportions following α-particle exposures. (elsevier.com)
  • 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 5% the speed of light. (wikipedia.org)
  • Conservation of momentum and energy in this reaction requires that the kinetic energy of the alpha-particle, Tα, is equal in magnitude. (wikipedia.org)
  • The kinetic energies of the emitted alpha particles can be measured very precisely so we should be careful to distinguish between the Qα‐value and the kinetic energy, Tα. (wikipedia.org)
  • 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. (biomedsearch.com)
  • We have simulated the alpha thermalization process using a Monte-Carlo technique, in which the alpha guiding center is followed between simulated collisions and Spitzer's collision model is used for the alpha-plasma interaction. (unt.edu)
  • For collisions in which the particles act upon each other with forces varying as the inverse square of the distance between them, the interference results in the scattering intensity varying above and below the classical value and rising to double the classical numbers at 45º. (royalsocietypublishing.org)
  • The alpha particle mass is 6.644656×10 -27 kg, which is equivalent to the energy of 3.72738 G eV . (statemaster.com)
  • 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)
  • However, the quantum tunnelling effect allows alphas to escape even though they do not have enough energy to overcome the nuclear force. (wikipedia.org)
  • The alpha particle distribution in collisional equilibrium forms a non-Maxwellian tail which spans orders of magnitude in energy, and it is this tail that is responsible for heating the plasma. (umd.edu)
  • Newly-born high-energy alpha particles are not expected to respond to turbulence as strongly as alpha particles that have slowed down to the bulk plasma temperature. (umd.edu)
  • This dissertation presents a low-collisionality derivation of gyrokinetics relevant for alpha particles and describes the upgrades made to the GS2 flux-tube code to handle general non-Maxwellian energy distributions. (umd.edu)
  • This is because some of the energy of the alpha particles is lost during their movement through the layer of active material. (wikipedia.org)
  • Here different alpha emitting sources of known energy were placed under the detector and the full energy peak is recorded. (wikipedia.org)
  • The fair agreement between experimental and theoretical hindrance factors suggest that the wave function obtained from the energy minima of the PES calculations contains an important part of the correlations that play a role for the alpha decay. (diva-portal.org)
  • Resonances in the yield of ground-state protons from alpha-particle bombardment of 31P were investigated in the energy range Eα = 1.7 − 3.3 MeV. (uu.nl)
  • Alpha-particles are believed to originate from trace amounts of thorium or uranium in either the plastic or ceramic materials used to package individual die. (google.com)
  • We investigated the feasibility of imaging alpha particle emissions in tumour sections from mice treated with Thorium-227 (using APOMAB), with and without prior chemotherapy and Timepix detector. (nih.gov)
  • This measurement refers to the amount of particles that are collected by a sensor over a given amount of time. (indium.com)
  • These results are consistent with our previous model suggesting that WTK1 has an error-prone repair pathway that is either missing or deficient in TK6, and further suggest that this pathway may be involved in the processing of α-particle-induced damage. (elsevier.com)
  • However, so-called long range alpha particles from ternary fission are three times as energetic, and penetrate three times as far. (wikipedia.org)
  • Also it is known that an [alpha]-particle is much more effective as an ionizing agent near the end of its range, and so if doubles or triples are produced it is to be expected that they would occur in greater number near to the end of the [alpha]-particle's path. (caltech.edu)
  • The range of the [alpha]-particles was varied by altering the pressure of the helium. (caltech.edu)
  • Since exposure to alpha particles-particularly through inhalation-occurs in a range of settings, understanding consequent risks is a public health priority. (occupationalcancer.ca)
  • alpha chain disease the most common heavy chain disease , occurring predominantly in young adults in the Mediterranean area, and characterized by plasma cell infiltration of the lamina propria of the small intestine resulting in malabsorption with diarrhea, abdominal pain, and weight loss, or, exceedingly rarely, by pulmonary involvement. (thefreedictionary.com)
  • Alpha particles are highly destructive, but they can't easily penetrate through materials - a piece of paper is enough to absorb them. (twigcarolina.com)
  • Whether a plasma can reach a burning state requires knowledge of the transport of alpha particles, and turbulence is one such source of transport. (umd.edu)
  • The curve showing the fraction of doubles to singles plotted against the distance from this source was similar in general form to the curve representing the ionizing power of the particles against distance from the source. (caltech.edu)
  • There is a lack of data related to activity uptake and particle track distribution in targeted alpha therapy. (nih.gov)
  • Factors underlying the cell growth-related bystander responses to alpha particles. (biomedsearch.com)
  • 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. (biomedsearch.com)