Neutron kill

Neutron Kill. A method of destroying objects, including enemy nuclear warheads in the atmosphere,... 

Chain reactions do not go on forever. The fog may clear and the improved visibility ends the succession of accidents. Neutron-scavenging control rods may be inserted to shut down a nuclear reactor. The chemical reactions which terminate polymer chain reactions are also an important part of the polymerization mechanism. Killing off the reactive intermediate that keeps the chain going is the essence of these termination reactions. Some unusual polymers can be formed without this termination these are called living polymers. 

Edwards et al. (1980) used a Cm-242 source to irradiate externally a thin film of blood. The energy of 4 9 MeV of the alpha particles were almost entirely absorbed by the blood. The dicentrics yield was linear from 0.11 to 4 2 Gy. From this resulted a RBE of 17.9 with respect to Co-60 gamma rays. It was, however, only 6.0 at the initial slope. To explain this RBE, which was low compared to that expected from neutron experiments, a model is presented taking into account cell killing and mitotic delay. 

Radiation therapy The use of high-energy radiation from x-rays, gamma rays, neutrons, and other sources to kill cancer cells and shrink tumors. Radiation may come from a machine outside the body (external-beam radiation therapy), or it may come from radioactive material placed in the body in the area near cancer cells (internal radiation therapy, implant radiation, or brachytherapy). Systemic radiation therapy uses a radioactive substance, such as a radiolabeled monodonal antibody, that circulates throughout the body. Also called radiotherapy, [nih]... 

The investigation into the sabotage of Pan Am Flight 103, which left 269 dead, indicated that the explosive used was Semtex H, a plasticized mixture of hexahydro-l,3,5-trinitro-s-triazine and pentaerythritol tetranitrate, and that the amount used was half the quantity that the fledgling technique of Thermal Neutron Analysis (TNA) was designed to detect. Although the placement of the explosive device was fortuitous (from the terrorists point of view) and the suitcase had not been screened by TNA, this event killed the TNA prototype program. 

The damaging effects that radioactivity can have on tissues are not all bad. To treat cancers, we want to kill cells - albeit the unhealthy, frantically replicating tumour cells, not healthy cells. If radioisotopes can be localized in tumours, they do their destructive business to good effect. Cobalt-60, made by neutron bombardment of stable cobalt-59, is a radioisotope with a half-life of 5.3 years that is used to treat cancer. 

In May 1938, Sam received the degree of Doctor of Philosophy in Chemistry. The title of his doctoral dissertation is Studies in Artificial Radioactivity. It has three sections (i) One involves fimdamental physics of iodine and neutrons, (ii) The second section concerned chemical reaction rates using radioactive iron, (iii) The third and longest section used radioactive tracers to study a fundamental problem in biology. It involved stomach-feeding radioactive phosphorus to rats, and after an elapsed period of time he killed the rats to determine which organs of the body had taken up the radioactivity. Ruben published six articles from his thesis research. 

Complexes of monoamide derivatives of dtpa with Ln + ions have been studied. Their stability constants are, as expected, less than those of dtpa itself Using [Gd(DTPA)] it has now been shown that these complexes get absorbed by the DNA of the cell they have been used to locate. If the gadolinium is subjected to thermal neutron treatment, short-range high-energy electrons are emitted that can kill the tumour cell whilst nearby healthy tissue is unaffected. ... 

The patient s body is then bombarded with neutrons that pass through tissue without harming healthy cells. They then collide with boron atoms. The boron is converted into lithium atoms, alpha particles, and gamma rays. An alpha particle is a helium atom without electrons. Gamma radiation is very high-energy radiation that can kill cells. 

Within a 3 day period in August 1945, atomic bombs were dropped on the Japanese cities of Hiroshima and Nagasaki, killing a total of 64 000 people within 1 km of the explosions as a result of blast, thermal effects, and instantaneous gamma and neutron irradiation. Since that time, a prospective epidemiological study has been conducted by a joint group of... 

Both the gray (Gy) and the rad are units of absorbed dose and reflect the amount of energy deposited into a mass of tissue (1 Gy = lOOrads). In this document, the absorbed dose is that dose received by the entire fetus (whole-body fetal dose). The referenced absorbed dose levels in this document are assumed to be from beta, gamma, or X-radiation. Neutron or proton radiation produces many of the health effects described herein at lower absorbed dose levels A fetal dose of 1 Gy (100 rads) will likely kill 50% of the embryos. The dose necessary to kill 100% of human embryos or fetuses before 18 weeks gestation is about 5Gy (500rads)... 

T. Yildrim, Q. Kill , S. Ciraci, P.M. Gehring, D.A. Neumann, P.E. Eaton T. Emrick (1999). Chem. Phys. Lett., 309, 234—240. Vibrations of the cubane molecule inelastic neutron scattering study and theory. 

Investigational pharmaceutical techniques also have been observed using ICP spectroscopic techniques. Boron neutron capture therapy is such an example, where malignant cells can be preferentially loaded with 10B and irradiated with thermal neutrons, thus killing the cancerous cells (59). This can be especially... 

A nuclear fission chain reaction in a reprocessing plant is an accident that must be carefully guarded against. Although such a critical reaction is not likely to generate sufficient energy to be mechanically destructive, it emits intense neutron and gamma radiation that can kill nearby plant personnel and may release radioactive fission products outside the plant. 

As carboranes are chemically stable and exhibit low toxicity to humans, biomedical applications of carborane systems, including cobaltacarboranes, have slowly emerged. The boron isotope °B accounts for about 20% of boron in nature, and it has the ability to capture a slow neutron and release an a-particle (equation 65). This reaction, if conducted in live tissue, will kill the immediate cell, but not its neighbors. Although early studies were done with toxic boron compounds, carboranes, with their low toxicities and high boron content, have been proven to be good substrates for boron capture neutron therapy (BCNT). Cobaltacarboranes have been employed in radioimmunodetection and radioimmunotherapy as well. ... 

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