Neutrons
Neutron Diffraction
Fast Neutrons
Boron Neutron Capture Therapy
Neutron Activation Analysis
Boron
Scattering, Radiation
Neutron Capture Therapy
Nuclear Fission
Activation Analysis
Boron Compounds
Relative Biological Effectiveness
Scattering, Small Angle
Deuterium Oxide
Linear Energy Transfer
Boranes
Radiotherapy, High-Energy
Californium
Nuclear Physics
Spectrometry, Gamma
Particle Accelerators
Isotopes
Cobalt Radioisotopes
Phosphoric Triester Hydrolases
X-Rays
Radiation Dosage
Water
Radiometry
Moon
Radiation Monitoring
Radioactivity
X-Ray Diffraction
Radioactive Pollutants
Dose-Response Relationship, Radiation
Radioactive Hazard Release
Gamma Rays
Deuterium
Solutions
Single-polymer dynamics in steady shear flow. (1/531)
The conformational dynamics of individual, flexible polymers in steady shear flow were directly observed by the use of video fluorescence microscopy. The probability distribution for the molecular extension was determined as a function of shear rate, gamma;, for two different polymer relaxation times, tau. In contrast to the behavior in pure elongational flow, the average polymer extension in shear flow does not display a sharp coil-stretch transition. Large, aperiodic temporal fluctuations were observed, consistent with end-over-end tumbling of the molecule. The rate of these fluctuations (relative to the relaxation rate) increased as the Weissenberg number, gamma;tau, was increased. (+info)Two concentric protein shell structure with spikes of silkworm Bombyx mori cytoplasmic polyhedrosis virus revealed by small-angle neutron scattering using the contrast variation method. (2/531)
The overall and internal structures of the silkworm Bombyx mori cytoplasmic polyhedrosis virus was investigated by small-angle neutron scattering using the contrast variation method. Data were collected in aqueous buffer solutions containing 0, 50, 75, and 100% D2O in the q range of 0.002 to 0.0774 A-1 at 5 degrees C. The radius of gyration at infinite contrast was estimated to be 336 A. The contrast matching point of the virus was determined to correspond to about 50% D2O level, evidence that the virus is composed of protein and nucleic acid. The virus was basically spherical and had a diameter of about 700 A. The main feature of its structure is the clustering of protein into two concentric shells separated by about 100 A. Most of the RNA moieties are located in the central core and between these two protein shells. However, the distance distribution function P(r) showed a minor distribution beyond a distance of r = 700 A, with a maximum particle distance of the virus of 1350 A. This is indicative of an external structure region with very low scattering density, in addition to the basic spherical structure. This external region is thought to correspond to twelve pyramidal protruding spikes shown by electron microscopic studies. (+info)Hydration-coupled dynamics in proteins studied by neutron scattering and NMR: the case of the typical EF-hand calcium-binding parvalbumin. (3/531)
The influence of hydration on the internal dynamics of a typical EF-hand calciprotein, parvalbumin, was investigated by incoherent quasi-elastic neutron scattering (IQNS) and solid-state 13C-NMR spectroscopy using the powdered protein at different hydration levels. Both approaches establish an increase in protein dynamics upon progressive hydration above a threshold that only corresponds to partial coverage of the protein surface by the water molecules. Selective motions are apparent by NMR in the 10-ns time scale at the level of the polar lysyl side chains (externally located), as well as of more internally located side chains (from Ala and Ile), whereas IQNS monitors diffusive motions of hydrogen atoms in the protein at time scales up to 20 ps. Hydration-induced dynamics at the level of the abundant lysyl residues mainly involve the ammonium extremity of the side chain, as shown by NMR. The combined results suggest that peripheral water-protein interactions influence the protein dynamics in a global manner. There is a progressive induction of mobility at increasing hydration from the periphery toward the protein interior. This study gives a microscopic view of the structural and dynamic events following the hydration of a globular protein. (+info)Effect of spatial inhomogeneity in dielectric permittivity on DNA double layer formation. (4/531)
In solutions of tetramethylammonium (TMA+) DNA (double stranded) without added low-molecular-weight salt, the counterion radial density is calculated using the cylindrical Poisson-Boltzmann equation with a distance-dependent quasimacroscopic dielectric permittivity. Comparisons with small-angle neutron scattering data indicate that any inhomogeneity in dielectric permittivity is confined to one or two solvent layers from the DNA surface. At least for TMA+, which may be too large to penetrate the grooves of DNA to any significant extent, dielectric inhomogeneity modeled in this way has no detectable effect on the radial distribution. (+info)Anisotropic motion of cholesterol in oriented DPPC bilayers studied by quasielastic neutron scattering: the liquid-ordered phase. (5/531)
Quasielastic neutron scattering (QENS) at two energy resolutions (1 and 14 microeV) was employed to study high-frequency cholesterol motion in the liquid ordered phase (lo-phase) of oriented multilayers of dipalmitoylphosphatidylcholine at three temperatures: T = 20 degrees C, T = 36 degrees C, and T = 50 degrees C. We studied two orientations of the bilayer stack with respect to the incident neutron beam. This and the two energy resolutions for each orientation allowed us to determine the cholesterol dynamics parallel to the normal of the membrane stack and in the plane of the membrane separately at two different time scales in the GHz range. We find a surprisingly high, model-independent motional anisotropy of cholesterol within the bilayer. The data analysis using explicit models of molecular motion suggests a superposition of two motions of cholesterol: an out-of-plane diffusion of the molecule parallel to the bilayer normal combined with a locally confined motion within the bilayer plane. The rather high amplitude of the out-of-plane diffusion observed at higher temperatures (T >/= 36 degrees C) strongly suggests that cholesterol can move between the opposite leaflets of the bilayer while it remains predominantly confined within its host monolayer at lower temperatures (T = 20 degrees C). The locally confined in-plane cholesterol motion is dominated by discrete, large-angle rotational jumps of the steroid body rather than a quasicontinous rotational diffusion by small angle jumps. We observe a significant increase of the rotational jump rate between T = 20 degrees C and T = 36 degrees C, whereas a further temperature increase to T = 50 degrees C leaves this rate essentially unchanged. (+info)Evolution of the internal dynamics of two globular proteins from dry powder to solution. (6/531)
Myoglobin and lysozyme picosecond internal dynamics in solution is compared to that in hydrated powders by quasielastic incoherent neutron scattering. This technique is sensitive to the motions of the nonexchangeable hydrogen atoms in a sample. Because these are homogeneously distributed throughout the protein structure, the average dynamics of the protein is described. We first propose an original data treatment to deal with the protein global motions in the case of solution samples. The validity of this treatment is checked by comparison with classical measurements of the diffusion constants. The evolution with the scattering vector of the width and relative contribution of the quasielastic component was then used to derive information on the amount of local diffusive motions and their characteristic average relaxation time. From dry powder to coverage by one water layer, the surface side chains progressively acquire the possibility to diffuse locally. On subsequent hydration, the main effect of water is to improve the rate of these diffusive motions. Motions with higher average amplitude occur in solution, about three times more than for a hydrated powder at complete coverage, with a shorter average relaxation time, approximately 4.5 ps compared to 9.4 ps for one water monolayer. (+info)Solution structure of copper ion-induced molecular aggregates of tyrosine melanin. (7/531)
Melanin, the ubiquitous biological pigment, provides photoprotection by efficient filtration of light and also by its antioxidant behavior. In solutions of synthetic melanin, both optical and antioxidant behavior are affected by the aggregation states of melanin. We have utilized small-angle x-ray and neutron scattering to determine the molecular dimensions of synthetic tyrosine melanin in its unaggregated state in D(2)O and H(2)O to study the structure of melanin aggregates formed in the presence of copper ions at various copper-to-melanin molar ratios. In the absence of copper ions, or at low copper ion concentrations, tyrosine melanin is present in solution as a sheet-like particle with a mean thickness of 12.5 A and a lateral extent of approximately 54 A. At a copper-to-melanin molar ratio of 0.6, melanin aggregates to form long, rod-like structures with a radius of 32 A. At a higher copper ion concentration, with a copper-to-melanin ratio of 1.0, these rod-like structures further aggregate, forming sheet-like structures with a mean thickness of 51 A. A change in the charge of the ionizable groups induced by the addition of copper ions is proposed to account for part of the aggregation. The data also support a model for the copper-induced aggregation of melanin driven by pi stacking assisted by peripheral Cu(2+) complexation. The relationship between our results and a previous hypothesis for reduced cellular damage from bound-to-melanin redox metal ions is also discussed. (+info)Polymer-cushioned bilayers. I. A structural study of various preparation methods using neutron reflectometry. (8/531)
This neutron reflectometry study evaluates the structures resulting from different methods of preparing polymer-cushioned lipid bilayers. Four different techniques to deposit a dimyristoylphosphatidylcholine (DMPC) bilayer onto a polyethylenimine (PEI)-coated quartz substrate were examined: 1) vesicle adsorption onto a previously dried polymer layer; 2) vesicle adsorption onto a bare substrate, followed by polymer adsorption; and 3, 4) Langmuir-Blodgett vertical deposition of a lipid monolayer spread over a polymer-containing subphase to form a polymer-supported lipid monolayer, followed by formation of the outer lipid monolayer by either 3) horizontal deposition of the lipid monolayer or 4) vesicle adsorption. We show that the initial conditions of the polymer layer are a critical factor for the successful formation of our desired structure, i.e., a continuous bilayer atop a hydrated PEI layer. Our desired structure was found for all methods investigated except the horizontal deposition. The interaction forces between these polymer-supported bilayers are investigated in a separate paper (Wong, J. Y., C. K. Park, M. Seitz, and J. Israelachvili. 1999. Biophys. J. 77:1458-1468), which indicate that the presence of the polymer cushion significantly alters the interaction potential. These polymer-supported bilayers could serve as model systems for the study of transmembrane proteins under conditions more closely mimicking real cellular membrane environments. (+info)I'm sorry for any confusion, but neutrons are not a medical term. They are a fundamental particle in physics and chemistry. Neutrons are neutral particles found in the nucleus of an atom, alongside protons. Together, they make up the atomic nucleus, while electrons orbit around it.
Neutrons are not typically discussed in the context of medical definitions unless it's in relation to nuclear medicine, radiation therapy or other specialized medical fields that involve ionizing radiation and nuclear reactions. If you have any questions related to medical terminology, I would be happy to help!
Neutron diffraction, also known as elastic neutron scattering, is not primarily a medical term, but rather a scientific technique used in various fields including physics, chemistry, and materials science. However, it can have indirect applications in the medical field, such as in the study of biological structures using neutron scattering techniques.
Neutron diffraction is a process that occurs when a beam of neutrons interacts with a material, causing the neutrons to scatter in various directions. The scattered neutrons carry information about the structure and arrangement of atoms within the material. By analyzing the patterns of scattered neutrons, researchers can determine details about the atomic and magnetic structure of materials at the molecular level.
In the context of medical research, neutron diffraction can be used to study the structures of biological molecules, such as proteins and nucleic acids, which are crucial for understanding their functions and interactions within living organisms. This information can contribute to advancements in drug design, development, and delivery, as well as a better understanding of disease mechanisms at the molecular level.
"Fast neutrons" are defined in the field of medical physics and nuclear medicine as neutrons that have high kinetic energy, typically greater than 1 MeV (mega-electron volts). These high-energy neutrons can cause ionization and damage to tissues and cells when they interact with matter, including biological tissue. They are produced in various nuclear reactions, such as those occurring in the core of a nuclear reactor or in the detonation of a nuclear weapon. In medical contexts, fast neutrons may be used in radiation therapy for cancer treatment, where they can deposit their energy directly into tumors and cause DNA damage that leads to cell death.
Boron Neutron Capture Therapy (BNCT) is a type of targeted radiation therapy used in the treatment of certain types of cancer. It involves the use of a boron-containing compound, which selectively accumulates in cancer cells. Once the compound has been taken up by the cancer cells, the patient is exposed to a beam of low-energy neutrons. When the neutrons interact with the boron-10 isotope within the compound, a nuclear reaction occurs, producing high-energy alpha particles that destroy the cancer cells.
The advantage of BNCT is that it allows for targeted delivery of radiation to cancer cells while minimizing exposure to healthy tissues. However, this type of therapy is still experimental and is only available in a limited number of medical centers worldwide. It has been studied most extensively in the treatment of brain tumors, head and neck cancers, and melanoma.
Neutron Activation Analysis (NAA) is not strictly a medical definition, but it's a technique used in the field of nuclear medicine and forensic medicine for material analysis and identification. Here's a general definition:
Neutron Activation Analysis is a non-destructive analytical method that uses nuclear reactions to identify and determine the concentration of elements within a sample. The sample is irradiated with neutrons, which induce nuclear reactions that produce radioactive isotopes of the elements present in the sample. The gamma radiation emitted by these radioisotopes is then measured and analyzed to quantify the elemental composition of the sample. This technique is particularly useful for detecting and measuring trace elements and isotopes, making it valuable in various fields such as archaeology, geology, nuclear medicine, and forensic science.
Boron is a chemical element with the symbol B and atomic number 5. It is a metalloid that is light-colored, hard, and highly resistant to corrosion. In its crystalline form, boron is nearly as hard as diamond.
In medicine, boron compounds have been studied for their potential therapeutic uses, particularly in the treatment of cancer. For example, boron neutron capture therapy (BNCT) is a type of radiation therapy that involves the use of boron-containing compounds to selectively deliver radiation to cancer cells.
Boron is also an essential micronutrient for plants and some animals, including humans. However, excessive exposure to boron can be toxic to humans and other organisms. Therefore, it is important to maintain appropriate levels of boron in the body and environment.
Radiation scattering is a physical process in which radiation particles or waves deviate from their original direction due to interaction with matter. This phenomenon can occur through various mechanisms such as:
1. Elastic Scattering: Also known as Thomson scattering or Rayleigh scattering, it occurs when the energy of the scattered particle or wave remains unchanged after the collision. In the case of electromagnetic radiation (e.g., light), this results in a change of direction without any loss of energy.
2. Inelastic Scattering: This type of scattering involves an exchange of energy between the scattered particle and the target medium, leading to a change in both direction and energy of the scattered particle or wave. An example is Compton scattering, where high-energy photons (e.g., X-rays or gamma rays) interact with charged particles (usually electrons), resulting in a decrease in photon energy and an increase in electron kinetic energy.
3. Coherent Scattering: In this process, the scattered radiation maintains its phase relationship with the incident radiation, leading to constructive and destructive interference patterns. An example is Bragg scattering, which occurs when X-rays interact with a crystal lattice, resulting in diffraction patterns that reveal information about the crystal structure.
In medical contexts, radiation scattering can have both beneficial and harmful effects. For instance, in diagnostic imaging techniques like computed tomography (CT) scans, radiation scattering contributes to image noise and reduces contrast resolution. However, in radiation therapy for cancer treatment, controlled scattering of therapeutic radiation beams can help ensure that the tumor receives a uniform dose while minimizing exposure to healthy tissues.
Neutron Capture Therapy (NCT) is a type of radiation therapy used in the treatment of cancer. It involves the use of low-energy thermal neutrons to be absorbed by atomic nuclei, which then undergo a nuclear reaction. This reaction results in the emission of high-energy particles that can destroy nearby cancer cells.
In NCT, a patient is administered with a boron-containing compound, which selectively accumulates in cancer cells. When the patient is then exposed to a beam of low-energy neutrons, the boron atoms absorb the neutrons and undergo a nuclear reaction, producing high-energy alpha particles that destroy the cancer cells.
The advantage of NCT is its ability to deliver a high dose of radiation directly to cancer cells while minimizing damage to surrounding healthy tissue. However, NCT is still an experimental treatment and is not widely available outside of clinical trials.
I'm sorry for any confusion, but "nuclear fission" is not a term typically used in medical definitions. It is a concept from nuclear physics. Nuclear fission is the process of splitting a heavy, unstable atomic nucleus (such as uranium-235 or plutonium-239) into two lighter nuclei, along with a few subatomic particles (like neutrons and photons) and a large release of energy. This process can occur naturally, but it is also used in nuclear power plants and atomic bombs.
Activation analysis is a technique used in medical and scientific research to analyze the composition of materials by measuring the radiation emitted from a sample that has been exposed to an intense source of radiation, such as a nuclear reactor or a particle accelerator. This process causes some of the atoms in the sample to become "activated," meaning they transform into unstable isotopes that emit gamma rays or other subatomic particles as they decay back to a stable state.
By measuring the energy and intensity of these emissions, researchers can identify the elements present in the sample and determine their relative abundances. Activation analysis can be used to analyze a wide range of materials, including biological tissues, environmental samples, and archaeological artifacts, and it has applications in fields such as forensics, geology, and nuclear medicine.
It is important to note that activation analysis involves handling radioactive materials and requires specialized training and equipment to ensure safety and accuracy.
Boron compounds refer to chemical substances that contain the element boron (symbol: B) combined with one or more other elements. Boron is a naturally occurring, non-metallic element found in various minerals and ores. It is relatively rare, making up only about 0.001% of the Earth's crust by weight.
Boron compounds can take many forms, including salts, acids, and complex molecules. Some common boron compounds include:
* Boric acid (H3BO3) - a weak acid used as an antiseptic, preservative, and insecticide
* Sodium borate (Na2B4O7·10H2O) - also known as borax, a mineral used in detergents, cosmetics, and enamel glazes
* Boron carbide (B4C) - an extremely hard material used in abrasives, ceramics, and nuclear reactors
* Boron nitride (BN) - a compound with properties similar to graphite, used as a lubricant and heat shield
Boron compounds have a variety of uses in medicine, including as antiseptics, anti-inflammatory agents, and drugs for the treatment of cancer. For example, boron neutron capture therapy (BNCT) is an experimental form of radiation therapy that uses boron-containing compounds to selectively target and destroy cancer cells.
It's important to note that some boron compounds can be toxic or harmful if ingested, inhaled, or otherwise exposed to the body in large quantities. Therefore, they should be handled with care and used only under the guidance of a trained medical professional.
Relative Biological Effectiveness (RBE) is a term used in radiation biology and medicine to describe the relative effectiveness of different types or energies of ionizing radiation in causing biological damage, compared to a reference radiation such as high-energy photons (X-rays or gamma rays). RBE takes into account the differences in biological impact between various types of radiation, which can be due to differences in linear energy transfer (LET), quality factor, and other factors. It is used to estimate the biological effects of mixed radiation fields, such as those encountered in radiotherapy treatments that combine different types or energies of radiation. The RBE value for a specific type of radiation is determined through experimental studies that compare its biological impact to that of the reference radiation.
Small angle scattering (SAS) in the context of medical physics refers to a technique used to study the structure of non-crystalline materials at the nanoscale. It is called "small angle" because the scattering angles are very small, typically less than a few degrees. This occurs when X-rays, neutrons, or electrons interact with a sample and are scattered in various directions. The intensity of the scattered radiation is measured as a function of the scattering angle, which provides information about the size, shape, and spatial distribution of the nanostructures within the sample. SAS can be used to study a wide range of biological and materials science samples, including proteins, polymers, colloids, and porous materials.
Deuterium oxide, also known as heavy water, is a compound consisting of two atoms of deuterium (a heavy isotope of hydrogen) and one atom of oxygen. Its chemical formula is D2O. Deuterium oxide has physical and chemical properties similar to those of regular water (H2O), but its density and boiling point are slightly higher due to the increased atomic weight. It is used in various scientific research applications, including as a tracer in biochemical and medical studies.
Linear Energy Transfer (LET) is a concept in radiation physics that describes the amount of energy that is transferred from an ionizing particle to a medium per unit length along its path. It is usually expressed in units of keV/μm (kiloelectron volts per micrometer). High-LET radiations, such as alpha particles and heavy ions, transfer more energy to the medium per unit length than low-LET radiations, such as X-rays and gamma rays. This results in a higher probability of producing dense ionizations and causing biological damage along the particle's path. Therefore, LET is an important factor in determining the relative biological effectiveness (RBE) of different types of radiation.
Boranes are a group of chemical compounds that contain only boron and hydrogen. The most well-known borane is BH3, also known as diborane. These compounds are highly reactive and have unusual structures, with the boron atoms bonded to each other in three-center, two-electron bonds. Boranes are used in research and industrial applications, including as reducing agents and catalysts. They are highly flammable and toxic, so they must be handled with care.
High-energy radiotherapy, also known as external beam radiation therapy (EBRT), is a type of cancer treatment that uses high-energy radiation beams to destroy cancer cells and shrink tumors. The radiation beams are produced by a machine called a linear accelerator (LINAC) and are directed at the tumor site from outside the body. High-energy radiotherapy can be used to treat many different types of cancer, either alone or in combination with other treatments such as surgery or chemotherapy.
The high-energy radiation beams used in this type of radiotherapy are able to penetrate deep into the body and target large areas, making it an effective treatment for cancers that have spread or are too large to be removed surgically. The dose and duration of treatment will depend on the type and stage of cancer being treated, as well as the patient's overall health.
High-energy radiotherapy works by damaging the DNA of cancer cells, which prevents them from dividing and growing. This ultimately leads to the death of the cancer cells. While radiation therapy can also damage normal cells, they are generally better able to repair themselves compared to cancer cells. Therefore, the goal of high-energy radiotherapy is to deliver a high enough dose to destroy the cancer cells while minimizing harm to surrounding healthy tissue.
It's important to note that high-energy radiotherapy requires careful planning and delivery to ensure that the radiation beams are focused on the tumor site and avoid healthy tissues as much as possible. This is typically done using imaging techniques such as CT, MRI, or PET scans to create a treatment plan that maps out the exact location and shape of the tumor. The patient will then undergo a series of treatments, usually scheduled daily over several weeks.
Californium is a synthetic actinide radioactive metallic element with the symbol Cf and atomic number 98. It was first synthesized in 1950 by Stanley G. Thompson, Kenneth Street, Jr., Albert Ghiorso, and Glenn T. Seaborg at the University of California, Berkeley. Californium is produced artificially in nuclear reactors and does not occur naturally.
Californium has several isotopes, with the most stable being californium-251, which has a half-life of 898 years. It is used in various applications, including as a power source for artificial heart pacemakers, as a neutron source for industrial radiography, and in cancer treatment.
It's important to note that due to its radioactive nature, californium must be handled with great care and precaution, and its use is regulated by governmental agencies such as the Nuclear Regulatory Commission in the United States.
I'm sorry for any confusion, but "nuclear physics" is not a term that has a medical definition. Nuclear physics is a branch of physics that deals with the properties and behavior of atomic nuclei, including their composition, structure, and reactions. It is studied in order to better understand the nature of matter and energy, and it has important applications in fields such as nuclear power, nuclear medicine, and nuclear weapons. However, it is not a term that is used in the context of medical diagnosis or treatment. If you have any questions about a medical term or concept, I would be happy to try to help!
Gamma spectrometry is a type of spectrometry used to identify and measure the energy and intensity of gamma rays emitted by radioactive materials. It utilizes a device called a gamma spectrometer, which typically consists of a scintillation detector or semiconductor detector, coupled with electronic circuitry that records and analyzes the energy of each detected gamma ray.
Gamma rays are a form of ionizing radiation, characterized by their high energy and short wavelength. When they interact with matter, such as the detector in a gamma spectrometer, they can cause the ejection of electrons from atoms or molecules, leading to the creation of charged particles that can be detected and measured.
In gamma spectrometry, the energy of each detected gamma ray is used to identify the radioactive isotope that emitted it, based on the characteristic energy levels associated with different isotopes. The intensity of the gamma rays can also be measured, providing information about the quantity or activity of the radioactive material present.
Gamma spectrometry has a wide range of applications in fields such as nuclear medicine, radiation protection, environmental monitoring, and nuclear non-proliferation.
I'm sorry for any confusion, but "Particle Accelerators" are not a medical term. Particle accelerators are large pieces of scientific equipment that use electromagnetic fields to propel charged particles to high speeds and contain them in well-defined beams. They are used for a variety of purposes, including research in particle physics, nuclear physics, and synchrotron light sources in a wide range of disciplines, such as condensed matter physics, chemistry, biology, and materials science. If you have any questions about medical terminology or concepts, I would be happy to help with those!
Isotopes are variants of a chemical element that have the same number of protons in their atomic nucleus, but a different number of neutrons. This means they have different atomic masses, but share similar chemical properties. Some isotopes are stable and do not decay naturally, while others are unstable and radioactive, undergoing radioactive decay and emitting radiation in the process. These radioisotopes are often used in medical imaging and treatment procedures.
Cobalt radioisotopes are radioactive forms of the element cobalt, which are used in various medical applications. The most commonly used cobalt radioisotope is Cobalt-60 (Co-60), which has a half-life of 5.27 years.
Co-60 emits gamma rays and beta particles, making it useful for radiation therapy to treat cancer, as well as for sterilizing medical equipment and food irradiation. In radiation therapy, Co-60 is used in teletherapy machines to deliver a focused beam of radiation to tumors, helping to destroy cancer cells while minimizing damage to surrounding healthy tissue.
It's important to note that handling and disposal of cobalt radioisotopes require strict safety measures due to their radioactive nature, as they can pose risks to human health and the environment if not managed properly.
Phosphoric triester hydrolases are a class of enzymes that catalyze the hydrolysis of phosphoric triesters into corresponding alcohols and phosphates. These enzymes play a crucial role in the detoxification of organophosphate pesticides and nerve agents, as well as in the metabolism of various endogenous compounds.
The term "phosphoric triester hydrolases" is often used interchangeably with "phosphotriesterases" or "organophosphorus hydrolases." These enzymes are characterized by their ability to cleave the P-O-C bond in phosphoric triesters, releasing a free alcohol and a diethyl phosphate moiety.
Phosphoric triester hydrolases have attracted significant interest due to their potential applications in bioremediation, biosensors, and therapeutics. However, it is important to note that the specificity and efficiency of these enzymes can vary widely depending on the structure and properties of the target compounds.
X-rays, also known as radiographs, are a type of electromagnetic radiation with higher energy and shorter wavelength than visible light. In medical imaging, X-rays are used to produce images of the body's internal structures, such as bones and organs, by passing the X-rays through the body and capturing the resulting shadows or patterns on a specialized film or digital detector.
The amount of X-ray radiation used is carefully controlled to minimize exposure and ensure patient safety. Different parts of the body absorb X-rays at different rates, allowing for contrast between soft tissues and denser structures like bone. This property makes X-rays an essential tool in diagnosing and monitoring a wide range of medical conditions, including fractures, tumors, infections, and foreign objects within the body.
Radiation dosage, in the context of medical physics, refers to the amount of radiation energy that is absorbed by a material or tissue, usually measured in units of Gray (Gy), where 1 Gy equals an absorption of 1 Joule of radiation energy per kilogram of matter. In the clinical setting, radiation dosage is used to plan and assess the amount of radiation delivered to a patient during treatments such as radiotherapy. It's important to note that the biological impact of radiation also depends on other factors, including the type and energy level of the radiation, as well as the sensitivity of the irradiated tissues or organs.
Borohydrides are a class of chemical compounds that contain boron and hydrogen ions (H-). The most common borohydride is sodium borohydride (NaBH4), which is a white, solid compound often used in chemistry as a reducing agent. Borohydrides are known for their ability to donate hydride ions (H:-) in chemical reactions, making them useful for reducing various organic and inorganic compounds. Other borohydrides include lithium borohydride (LiBH4), potassium borohydride (KBH4), and calcium borohydride (Ca(BH4)2).
Medical definitions of water generally describe it as a colorless, odorless, tasteless liquid that is essential for all forms of life. It is a universal solvent, making it an excellent medium for transporting nutrients and waste products within the body. Water constitutes about 50-70% of an individual's body weight, depending on factors such as age, sex, and muscle mass.
In medical terms, water has several important functions in the human body:
1. Regulation of body temperature through perspiration and respiration.
2. Acting as a lubricant for joints and tissues.
3. Facilitating digestion by helping to break down food particles.
4. Transporting nutrients, oxygen, and waste products throughout the body.
5. Helping to maintain healthy skin and mucous membranes.
6. Assisting in the regulation of various bodily functions, such as blood pressure and heart rate.
Dehydration can occur when an individual does not consume enough water or loses too much fluid due to illness, exercise, or other factors. This can lead to a variety of symptoms, including dry mouth, fatigue, dizziness, and confusion. Severe dehydration can be life-threatening if left untreated.
Radiometry is the measurement of electromagnetic radiation, including visible light. It quantifies the amount and characteristics of radiant energy in terms of power or intensity, wavelength, direction, and polarization. In medical physics, radiometry is often used to measure therapeutic and diagnostic radiation beams used in various imaging techniques and cancer treatments such as X-rays, gamma rays, and ultraviolet or infrared light. Radiometric measurements are essential for ensuring the safe and effective use of these medical technologies.
I'm sorry for any confusion, but "Moon" is not a commonly used medical term. The moon is a natural satellite that orbits around the Earth and is not related to medical terminology or anatomy. If you have any questions about medical definitions or topics, I would be happy to help!
Radiation monitoring is the systematic and continuous measurement, assessment, and tracking of ionizing radiation levels in the environment or within the body to ensure safety and to take appropriate actions when limits are exceeded. It involves the use of specialized instruments and techniques to detect and quantify different types of radiation, such as alpha, beta, gamma, neutron, and x-rays. The data collected from radiation monitoring is used to evaluate radiation exposure, contamination levels, and potential health risks for individuals or communities. This process is crucial in various fields, including nuclear energy production, medical imaging and treatment, radiation therapy, and environmental protection.
Radioactivity is not typically considered within the realm of medical definitions, but since it does have medical applications and implications, here is a brief explanation:
Radioactivity is a natural property of certain elements (referred to as radioisotopes) that emit particles or electromagnetic waves due to changes in their atomic nuclei. This process can occur spontaneously without any external influence, leading to the emission of alpha particles, beta particles, gamma rays, or neutrons. These emissions can penetrate various materials and ionize atoms along their path, which can cause damage to living tissues.
In a medical context, radioactivity is used in both diagnostic and therapeutic settings:
1. Diagnostic applications include imaging techniques such as positron emission tomography (PET) scans and single-photon emission computed tomography (SPECT), where radioisotopes are introduced into the body to visualize organ function or detect diseases like cancer.
2. Therapeutic uses involve targeting radioisotopes directly at cancer cells, either through external beam radiation therapy or internal radiotherapy, such as brachytherapy, where a radioactive source is placed near or within the tumor.
While radioactivity has significant medical benefits, it also poses risks due to ionizing radiation exposure. Proper handling and safety measures are essential when working with radioactive materials to minimize potential harm.
X-ray diffraction (XRD) is not strictly a medical definition, but it is a technique commonly used in the field of medical research and diagnostics. XRD is a form of analytical spectroscopy that uses the phenomenon of X-ray diffraction to investigate the crystallographic structure of materials. When a beam of X-rays strikes a crystal, it is scattered in specific directions and with specific intensities that are determined by the arrangement of atoms within the crystal. By measuring these diffraction patterns, researchers can determine the crystal structures of various materials, including biological macromolecules such as proteins and viruses.
In the medical field, XRD is often used to study the structure of drugs and drug candidates, as well as to analyze the composition and structure of tissues and other biological samples. For example, XRD can be used to investigate the crystal structures of calcium phosphate minerals in bone tissue, which can provide insights into the mechanisms of bone formation and disease. Additionally, XRD is sometimes used in the development of new medical imaging techniques, such as phase-contrast X-ray imaging, which has the potential to improve the resolution and contrast of traditional X-ray images.
Radioactive pollutants are defined as any harmful radioactive substances that are discharged into the environment and pose risks to human health and the ecosystem. These pollutants can be in the form of gases, liquids, or solids and can contaminate air, water, and soil. They originate from various sources such as nuclear power plants, medical facilities, industrial operations, and military activities.
Radioactive pollutants emit ionizing radiation, which can cause damage to living cells and DNA, leading to genetic mutations, cancer, and other health problems. Exposure to high levels of radioactivity can result in acute radiation sickness, including symptoms such as nausea, vomiting, diarrhea, and fever. Long-term exposure to low levels of radiation can increase the risk of developing cancer and other diseases over time.
Radioactive pollutants can also have negative impacts on the environment, contaminating soil and water and reducing biodiversity in affected areas. They can persist in the environment for long periods, making it difficult to clean up and remediate contaminated sites. Therefore, proper management and regulation of radioactive materials are essential to prevent their release into the environment and protect public health and the environment.
A dose-response relationship in radiation refers to the correlation between the amount of radiation exposure (dose) and the biological response or adverse health effects observed in exposed individuals. As the level of radiation dose increases, the severity and frequency of the adverse health effects also tend to increase. This relationship is crucial in understanding the risks associated with various levels of radiation exposure and helps inform radiation protection standards and guidelines.
The effects of ionizing radiation can be categorized into two types: deterministic and stochastic. Deterministic effects have a threshold dose below which no effect is observed, and above this threshold, the severity of the effect increases with higher doses. Examples include radiation-induced cataracts or radiation dermatitis. Stochastic effects, on the other hand, do not have a clear threshold and are based on probability; as the dose increases, so does the likelihood of the adverse health effect occurring, such as an increased risk of cancer.
Understanding the dose-response relationship in radiation exposure is essential for setting limits on occupational and public exposure to ionizing radiation, optimizing radiation protection practices, and developing effective medical countermeasures in case of radiation emergencies.
A "Radioactive Hazard Release" is defined in medical and environmental health terms as an uncontrolled or accidental release of radioactive material into the environment, which can pose significant risks to human health and the ecosystem. This can occur due to various reasons such as nuclear accidents, improper handling or disposal of radioactive sources, or failure of radiation-generating equipment.
The released radioactive materials can contaminate air, water, and soil, leading to both external and internal exposure pathways. External exposure occurs through direct contact with the skin or by inhaling radioactive particles, while internal exposure happens when radioactive substances are ingested or inhaled and become deposited within the body.
The health effects of radioactive hazard release depend on several factors, including the type and amount of radiation released, the duration and intensity of exposure, and the sensitivity of the exposed individuals. Potential health impacts range from mild radiation sickness to severe diseases such as cancer and genetic mutations, depending on the level and length of exposure.
Prompt identification, assessment, and management of radioactive hazard releases are crucial to minimize potential health risks and protect public health.
Gamma rays are a type of ionizing radiation that is released from the nucleus of an atom during radioactive decay. They are high-energy photons, with wavelengths shorter than 0.01 nanometers and frequencies greater than 3 x 10^19 Hz. Gamma rays are electromagnetic radiation, similar to X-rays, but with higher energy levels and the ability to penetrate matter more deeply. They can cause damage to living tissue and are used in medical imaging and cancer treatment.
Deuterium is a stable and non-radioactive isotope of hydrogen. The atomic nucleus of deuterium, called a deuteron, contains one proton and one neutron, giving it an atomic weight of approximately 2.014 atomic mass units (amu). It is also known as heavy hydrogen or heavy water because its hydrogen atoms contain one neutron in addition to the usual one proton found in common hydrogen atoms.
Deuterium occurs naturally in trace amounts in water and other organic compounds, typically making up about 0.015% to 0.018% of all hydrogen atoms. It can be separated from regular hydrogen through various methods such as electrolysis or distillation, and it has many applications in scientific research, particularly in the fields of chemistry and physics.
In medical contexts, deuterium is sometimes used as a tracer to study metabolic processes in the body. By replacing hydrogen atoms in specific molecules with deuterium atoms, researchers can track the movement and transformation of those molecules within living organisms. This technique has been used to investigate various physiological processes, including drug metabolism, energy production, and lipid synthesis.
In the context of medical terminology, "solutions" refers to a homogeneous mixture of two or more substances, in which one substance (the solute) is uniformly distributed within another substance (the solvent). The solvent is typically the greater component of the solution and is capable of dissolving the solute.
Solutions can be classified based on the physical state of the solvent and solute. For instance, a solution in which both the solvent and solute are liquids is called a liquid solution or simply a solution. A solid solution is one where the solvent is a solid and the solute is either a gas, liquid, or solid. Similarly, a gas solution refers to a mixture where the solvent is a gas and the solute can be a gas, liquid, or solid.
In medical applications, solutions are often used as vehicles for administering medications, such as intravenous (IV) fluids, oral rehydration solutions, eye drops, and topical creams or ointments. The composition of these solutions is carefully controlled to ensure the appropriate concentration and delivery of the active ingredients.
Molecular models are three-dimensional representations of molecular structures that are used in the field of molecular biology and chemistry to visualize and understand the spatial arrangement of atoms and bonds within a molecule. These models can be physical or computer-generated and allow researchers to study the shape, size, and behavior of molecules, which is crucial for understanding their function and interactions with other molecules.
Physical molecular models are often made up of balls (representing atoms) connected by rods or sticks (representing bonds). These models can be constructed manually using materials such as plastic or wooden balls and rods, or they can be created using 3D printing technology.
Computer-generated molecular models, on the other hand, are created using specialized software that allows researchers to visualize and manipulate molecular structures in three dimensions. These models can be used to simulate molecular interactions, predict molecular behavior, and design new drugs or chemicals with specific properties. Overall, molecular models play a critical role in advancing our understanding of molecular structures and their functions.
Ultracold neutrons
Neutrons (album)
Neutrons (video game)
Dynamic Albedo of Neutrons
Neutron
Mud Boy and the Neutrons
Neutron temperature
Prompt neutron
Neutron flux
Neutron poison
Neutron reflector
Neutron imaging
Neutron howitzer
Neutron scattering
Neutron microscope
Neutron spectroscopy
Neutron (synthesizer)
Neutron (comics)
Virgin neutron
Neutron (disambiguation)
Neutron (Linus)
Super-Neutron
Jimmy Neutron
Neutron backscattering
Neutron scanner
Neutron probe
Neutron source
Neutron generator
Neutron emission
Neutron interferometer
Imagine the Universe!
Ultracold neutrons - Wikipedia
Neutrons find 'missing' magnetism of plutonium | ScienceDaily
Neutron Physics Group | NIST
Accelerating Neutron with Intel DPDK | PPT
Science Area: Neutron Science | ORNL
Neutron Diffraction - George Edward Bacon - Google Books
A neutron moments computer code, moment I: | NIST
How Neutrons Might Escape Into Another Universe | MIT Technology Review
Constraining neutron-star matter with microscopic and macroscopic collisions | Nature
Neutron 4 Gate
Sweden - ILL Neutrons for Society
Users - ILL Neutrons for Society
Precision experiment first to isolate, measure weak force between protons, neutrons | ORNL
subject:'\[openstack\-dev\] Stepping down from Neutron core team'
The Mystery of the Neutron Lifetime | Department of Energy
Measurement of neutron source emission rate - NPL
Directional fast-neutron detector (Patent) | DOE Patents
Comment #1 : Bug #1268611 : Bugs : neutron
rotating neutron star Archives - Universe Today
Why is'nt neutron the answer?
Software - ILL Neutrons for Society
Scientists test world's most powerful neutron research facility
In neutron stars, minority rules | Astronomy.com
Neutron 4-Audio Mixing Software | iZotope
Neutrons | DK3 | Touch and Go / Quarterstick Records
Petition · Bring Back the Adventures of Jimmy Neutron · Change.org
First Glimpse of Colliding Neutron Stars Yields Stunning Pics | Space
Gravitational Waves Probe Exotic Matter inside Neutron Stars - Scientific American
Magnetized neutron star1
- A rupture in the crust of a highly magnetized neutron star, shown here in an artist's rendering, can trigger high-energy eruptions. (nasa.gov)
Rotating neutron stars1
- Pulsars are rotating neutron stars observed to have pulses of radiation at very regular intervals that typically range from milliseconds to seconds. (nasa.gov)
Spallation Neutro5
- Using neutron measurements made on the ARCS instrument at ORNL's Spallation Neutron Source, a DOE Office of Science User Facility, Janoschek and his team determined that the fluctuations have different numbers of electrons in plutonium's outer valence shell--an observation that also explains abnormal changes in plutonium's volume in its different phases. (sciencedaily.com)
- Building on the knowledge gained at LANL, the team moved the project to ORNL to take advantage of the high neutron beam intensity produced at the lab's Spallation Neutron Source. (ornl.gov)
- From left, ORNL staff Matthew Frost and Leah Broussard work at the Magnetism Reflectometer at the Spallation Neutron Source, used for a search for mirror neutrons. (energy.gov)
- After seven years of construction, the Oak Ridge National Laboratory achieved a millisecond of neutron production at the $1.4 billion (Ђ1.12 billion) Spallation Neutron Source facility, the largest U.S. civilian science project. (pravda.ru)
- Caption: This visual representation of neutron data from ORNL's Spallation Neutron Source shows the evolution of spin waves as a function of increasing energy for the iron chalcogenide FeTe. (scienceblog.com)
Protons and neutrons10
- Dec. 19, 2018-A team of scientists has for the first time measured the elusive weak interaction between protons and neutrons in the nucleus of an atom. (ornl.gov)
- Protons and neutrons are made of smaller particles called quarks that are bound together by the strong interaction, which is one of the four known forces of nature: strong force, electromagnetism, weak force and gravity. (ornl.gov)
- The weak force also connects the axial spin and direction of motion of the nuclear particles, revealing subtle aspects of how quarks move inside protons and neutrons. (ornl.gov)
- In the few seconds after protons and neutrons formed but before they joined together into elements, there was a precise bit of timing. (energy.gov)
- At a certain point, it got cool enough that protons and neutrons almost instantaneously joined to form helium and hydrogen . (energy.gov)
- Let's start simple: In the nucleus of an atom, there are protons and neutrons, surrounded by electrons. (astronomy.com)
- As they move, the protons and neutrons can come into contact and interact with each other. (astronomy.com)
- The same principle still holds, however - because they are moving, the protons and neutrons can come into contact and interact with each other in short-range correlations, just as in an atomic nucleus. (astronomy.com)
- The Continuous Electron Beam Accelerator Facility Large Acceptance Spectrometer at Thomas Jefferson Laboratory allows researchers to study interactions between protons and neutrons in atomic nuclei. (astronomy.com)
- the total number of protons and neutrons in the nucleus of an atom. (cdc.gov)
Alamos Neutron Science Center2
- We are pursuing applications for these filters at the NCNR, the Intense Pulsed Neutron Source at Argonne National Laboratory, and the Los Alamos Neutron Science Center. (nist.gov)
- The high intensity of the SNS, along with other improvements, allowed a count rate that is nearly 100 times higher compared with previous operation at the Los Alamos Neutron Science Center. (ornl.gov)
Physics10
- The Neutron Physics group maintains and supports the nation's premier fundamental neutron physics user facilities. (nist.gov)
- In summary, the NI&D group provides measurement services, standards, and fundamental research in support of NIST's mission as it relates to neutron technology and neutron physics. (nist.gov)
- The experiments in question involve trapping ultracold neutrons in bottles at places like the Institut Laue Langevin in Grenoble, France, and the Saint Petersburg Institute of Nuclear Physics. (technologyreview.com)
- The goal of the experiment was to isolate and measure one component of this weak interaction, which manifested as gamma rays that could be counted and verified with high statistical accuracy," said David Bowman, co-author and team leader for neutron physics at ORNL. (ornl.gov)
- The NPDGamma Experiment, the first to be carried out at the Fundamental Neutron Physics Beamline at SNS, channeled cold neutrons toward a target of liquid hydrogen. (ornl.gov)
- There is a theory for the weak force between the quarks inside the proton and neutron, but the way that the strong force between the quarks translates into the force between the proton and the neutron is not fully understood," said W. Michael Snow, co-author and professor of experimental nuclear physics at Indiana University. (ornl.gov)
- Nuclear physicists first started studying the neutron lifetime because of its essential role in physics. (energy.gov)
- We combine all the things we know currently, including gravitational waves and electromagnetic waves, information from single neutron stars, and theoretical computations from nuclear physics. (scientificamerican.com)
- V. Pomjakushin , "Advanced magnetic structures: classification and determination by neutron diffraction" (Exercize) Lecture given 24.03.2010 at the ETHZ lecture course "Neutron Scattering in Condensed Matter Physics" of Prof. A.Zheludev. (psi.ch)
- The main focus of the course will be on neutron scattering and how these methods can be applied to scientific questions, focusing on examples drawn from physics. (lu.se)
Diffractometer4
- I've spent the last 10 years of my career designing and building a neutron scattering instrument called CANDOR: Chromatic Analyzer Neutron Diffractometer or Reflectometer. (bls.gov)
- We will perform neutron diffraction experiment with MnS using powder diffractometer HRPT/SINQ. (psi.ch)
- High Resolution Powder Diffractometer for Thermal Neutrons. (psi.ch)
- One is the visualization method of the corrosion and its related water movement of painted steels and the analytical method of the quantitative estimation of the water movement in the painted steels, the other is the neutron engineering diffractometer for the texture evaluation and the austenite volume fraction estimation of iron and steel. (riken.jp)
ORNL2
- Using neutron scattering, researchers from the Department of Energy's Los Alamos and Oak Ridge (ORNL) national laboratories have made the first direct measurements of a unique characteristic of plutonium's fluctuating magnetism. (sciencedaily.com)
- Herb Mook was a driving force in ORNL neutron science for four decades, a prolific and pioneering experimentalist, and a leader and mentor for generations of neutron scattering scientists. (ornl.gov)
Cold neutrons1
- Moreover, materials with a high optical potential (~ 1 µeV) are used for the design of cold neutrons optical components. (wikipedia.org)
World's2
- It produces more than 2 million billion neutrons each second through an area less than half the size of a dime, providing researchers with the Western world's highest reactor-based neutron flux. (ornl.gov)
- The team's neutron scattering analysis of the materials was made possible by the high intensity of the neutron beams provided by the SNS, which is the world's most powerful pulsed neutron source. (scienceblog.com)
Properties of the neutron1
- The size of the neutron star directly depends on the behavior of matter inside the core, so this gives us a better understanding about the properties of the neutron star material," Dietrich says. (scientificamerican.com)
Ridge National Laboratory3
- Paul Langan is the associate laboratory director for neutron sciences at Oak Ridge National Laboratory. (ornl.gov)
- Through a unique neutron experiment at the Department of Energy's Oak Ridge National Laboratory, experimental physicists resolved the weak force between the particles at the atom's core, predicted in the Standard Model that describes the elementary particles and their interactions. (ornl.gov)
- Researchers at the Department of Energy's Oak Ridge National Laboratory and the University of Tennessee, using the Spallation Neutron Source's ARCS Wide Angular Range Chopper Spectrometer, performed spin-wave studies of magnetically ordered iron chalcogenides. (scienceblog.com)
Ejected from a nuclear reactor1
- These neutrons are ejected from a nuclear reactor and travel down long mirrored tubes. (bls.gov)
Diffraction3
- Antiferromagnetic (AFM) ordering of Mn spins in manganese sulfide MnS or manganese oxide MnO will be determined by powder neutron diffraction. (psi.ch)
- During the practicum we will try to reproduce the one of the neutron diffraction experiments performed during 1946-1951 for which C.G. Shull was honored with the Nobel Prize in 1994. (psi.ch)
- Determination of the magnetic structure from powder neutron diffraction. (psi.ch)
Slow neutrons1
- The total energy changes with ~60 neV/T. It was Enrico Fermi who realized first that the coherent scattering of slow neutrons would result in an effective interaction potential for neutrons traveling through matter, which would be positive for most materials. (wikipedia.org)
Modern Neutron Science2
Rate of neutron2
- We provide two main calibration services: measurement of the emission rate of neutron sources, and calibration of neutron detectors used for personnel protection. (nist.gov)
- There are two processes at work here: the rate of neutron decay and the rate at which neutrons escape from the bottle. (technologyreview.com)
National Laboratory1
- The neutron lifetime is one of the least well-known fundamental parameters in the Standard Model," said Zhaowen Tang, a physicist at DOE's Los Alamos National Laboratory (LANL). (energy.gov)
Sciences Directorate1
- As we analyze the spectra, we find that even though the nearest neighbor exchange couplings between chalcogenide and pnictide atoms are different, the next nearest neighbor exchange couplings are closely similar," said Pengcheng Dai, who has a joint appointment with ORNL's Neutron Sciences Directorate and the University of Tennessee. (scienceblog.com)
Scattering16
- Its neutron scattering stations allow scientists to better understand the structure and dynamics of matte. (ornl.gov)
- Jet planes, credit cards, drugs, compact discs, shatterproof windshields, mapping of oil deposits, environmentally friendly dry-cleaning, batteries and fuel cells all have been created or improved through neutron-scattering examinations pioneered by Nobel Laureate Clifford Shull at Oak Ridge in the 1940s and 1950s. (pravda.ru)
- Is there a nontechnical way to explain what a neutron scattering instrument does? (bls.gov)
- CANDOR, like all neutron scattering instruments, uses neutrons to analyze materials. (bls.gov)
- For example, neutron scattering was used to gain a clearer picture of the lightning-fast molecular dance occurring within the membrane that encloses each cell in our body. (bls.gov)
- Neutron scattering was also used to evaluate synthetic knee meniscus material. (bls.gov)
- Feb. 7, 2011 - Neutron scattering analysis of two families of iron-based materials suggests that the magnetic interactions thought responsible for high-temperature superconductivity may lie "two doors down": The key magnetic exchange pairings occur in a next-nearest-neighbor ordering of atoms, rather than adjacent atoms. (scienceblog.com)
- The Neutron Scattering GRS provides a unique forum for young doctoral and post-doctoral researchers to present their work, discuss new methods, cutting edge ideas, and pre-published data, as well as to build collaborative relationships with their peers. (grc.org)
- The objective of the 2023 GRS on neutron scattering is to bring together early-career neutron scientists, experimentalists and theorists from different communities of soft and condensed matter, with a wide range of scientific and technical expertise. (grc.org)
- This GRS will be held in conjunction with the "Neutron Scattering" Gordon Research Conference (GRC). (grc.org)
- All projects will apply and develop the use of neutron scattering in combination with computer simulations as well as other experimental techniques. (lu.se)
- The Swedish Neutron Scattering Society (SNSS, www.snss.se ) is an organization open to all those who are using, or interested in the use of, neutron scattering techniques in Sweden. (lu.se)
- SNSS is affiliated to the European Neutron Scattering Association (ENSA), and aims to represent the interests of the Swedish neutron community in national strategy development around neutron science. (lu.se)
- We focus on using scattering techniques to look at the structure and dynamics associated with these strong electron corrrelations, particularly neutron and X-ray methods. (lu.se)
- To measure the effects of high pressure using neutron scattering presents some difficulties, as relatively large samples are required to get a good signal-to-noise ratio, and because the pressure cells generate a lot of background scattering. (lu.se)
- We are working with collaborators at KTH (Patrik Henelius) and ESS (Pascale Deen, Malcolm Guthrie, Rasmus Toft-Petersen) to develop new uniaxial and hydrostatic pressure cells, optimized for neutron scattering at the ESS, on a project funded by VR. (lu.se)
Nucleus7
- They had chosen the simplest nucleus consisting of one neutron and one proton for the study. (ornl.gov)
- Like many other subatomic particles, the neutron doesn't last long outside of the nucleus. (energy.gov)
- Now, instead of the nucleus of an atom, picture a neutron star. (astronomy.com)
- It's still a packed system of particles constrained into a certain space, but this time the particles are mostly neutrons, with just a few protons, and the space is much larger than an atomic nucleus. (astronomy.com)
- We think that when you have a neutron-rich nucleus, the protons move faster than the neutrons, so in some sense protons carry the action on average," said team member Or Hen of MIT in a press release . (astronomy.com)
- Alpha particles are charged particles made up of 2 protons and 2 neutrons-essentially the nucleus of a helium atom. (medscape.com)
- the nucleus of a helium atom, made up of two neutrons and two protons with a charge of +2. (cdc.gov)
Dense7
- However, our knowledge about dense matter explored in the cores of neutron stars remains limited. (nature.com)
- The nuclear equation of state (EOS) describes dense matter probed in terrestrial experiments with atomic nuclei as well as in astrophysical observations of neutron stars. (nature.com)
- The nuclear EOS is governed by quantum chromodynamics (QCD), the theory of strong interactions, but direct calculations of dense matter in neutron stars based on QCD are not feasible at present. (nature.com)
- A very promising tool is the multi-messenger astrophysics analysis of neutron stars and their collisions, which provides access to dense neutron-rich matter not accessible in terrestrial experiments at present. (nature.com)
- Instead, the data came from neutron star analogs - dense atomic nuclei here on Earth. (astronomy.com)
- Neutron stars are the leftover, dense cores of larger stars that ended their lives in supernova explosions. (space.com)
- Such a star ends its life cycle in a supernova explosion, and the leftover core of the star collapses, causing protons and electrons to smoosh together at such dense rates that neutrons are formed. (howstuffworks.com)
Subatomic3
- For the first time Friday, scientists fired up a powerful new source for creating subatomic neutron particles that could boost research into new materials, superconductors and therapeutic drugs. (pravda.ru)
- It's to do with a nuclear reaction, so the subatomic particle of the neutron collides with silicon atoms in these devices, and that causes charge to be dumped into the devices, charge is the thing that makes electronics work. (thenakedscientists.com)
- Neutrons, which carry no electric charge but can act as subatomic magnets, are well suited for studying atom-scale spin characteristics. (scienceblog.com)
Reflectometer1
- The Neutron Optics and Computing group is responsible for operation of the BOA beamline and the polarized neutron reflectometer NARZISS. (psi.ch)
OpenStack3
- Accelerating Neutron with Intel DPDK from #vBrownBag session at OpenStack Summit Atlanta 2014. (slideshare.net)
- 1. Many OpenStack deployments use Open vSwitch plugin for Neutron. (slideshare.net)
- Created two ports manually in the newly created neutron network $ openstack port create --network demo2 port2-2 $ openstack port create --network demo2 port2-2 3. (redhat.com)
Synchrotron Radiation1
- To this end, we use a wide range of neutron facilities and synchrotron radiation facilities in Europe and around the world, soon to include the European Spallation Source at Lund. (lu.se)
Detector2
- Neutrons transported from the reactor though a vertical evacuated guide about 11 meters long are slowed down by gravity, so only those that happened to have ultracold energies can reach the detector at the top of the tube. (wikipedia.org)
- Compendium of neutron spectra and detector responses for radiation protection purposes / R. V. Griffith, J. Palfalvi, U. Madhvanath. (who.int)
20182
- From 4-5 October, 2018, the fourth international workshop on High Brilliance Neutron Sources based on a compact accelerator system was held in Unkel, Germany. (fz-juelich.de)
- Participants of the High Brilliance Neutron Source Workshop 2018 at the Rheinhotel Schulz in Unkel. (fz-juelich.de)
High neutron1
- This trend suggests that, in objects with high neutron density, the minority protons carry a disproportionally large part of the average energy," said team member Eli Piasetzky of Tel Avivi University. (astronomy.com)
Fast-neutron1
- The others are the fast neutron imaging applications. (riken.jp)
Jimmy Neutron1
- Jimmy Neutron was a show that marveled the minds of youth in the early 2000s. (change.org)
Experiment7
- Through a great combination of dynamical mean field theory and experiment, neutron spectroscopy, it demonstrates that the magnetic moment in delta-plutonium is dynamic, driven by valence fluctuations, rather than missing. (sciencedaily.com)
- So one idea is to carry out a neutron trapping experiment that lasts for a year or more, allowing the Earth to complete at least one orbit of the Sun. (technologyreview.com)
- This work combines nuclear theory, nuclear experiment and astrophysical observations, and shows how joint analyses can shed light on the properties of neutron-rich supranuclear matter over the density range probed in neutron stars. (nature.com)
- The gap between our current knowledge of the EOS stemming from nuclear theory and experiment at low densities and astrophysical observations of neutron stars at higher densities can be bridged by heavy-ion collision (HIC) experiments. (nature.com)
- Scientists analyzed the gamma rays emitted during the NPDGamma Experiment and found parity-violating asymmetry, which is a specific change in behavior in the force between a neutron and a proton. (ornl.gov)
- The scientists ran the experiment numerous times for about two decades, counting and characterizing the gamma rays and collecting data from these events based on neutron spin direction and other factors. (ornl.gov)
- To determine which pairs are more likely to form in a neutron star - and thus, which pairs have the most control over its properties - the researchers mined data from an experiment run with the CEBAF in 2004, which observed carbon, aluminum, iron, and lead atoms, each of which has a higher ratio of neutrons to protons than the last. (astronomy.com)
Radiation9
- Many neutron stars are likely undetectable because they simply do not emit enough radiation. (nasa.gov)
- In binary systems, some neutron stars can be found accreting materials from their companions, emitting electromagnetic radiation powered by the gravitational energy of the accreting material. (nasa.gov)
- In a magnetar, with its huge magnetic field, movements in the crust cause the neutron star to release a vast amount of energy in the form of electromagnetic radiation. (nasa.gov)
- We are participating in a Consultative Committee for Ionizing Radiation (CCRI) comparison of thermal neutron fluence rate measurements, characterizing four different beam qualities at the NCNR, and carrying out comparisons of NIST standard neutron sources. (nist.gov)
- By measuring the gamma radiation it is possible to determine accurately the neutron emission rate of the source. (npl.co.uk)
- A neutron bomb is a thermonuclear weapon that produces minimal blast and heat but releases large amounts of lethal radiation that can penetrate armour and is especially destructive to human tissue. (aljazeera.com)
- Most head-and-neck cancers that recur locally after prior full-dose conventional radiation therapy respond to Boron Neutron Capture Therapy (BNCT). (scienceblog.com)
- Boron neutron capture therapy (BNCT) is a form of targeted radiation treatment for cancer. (scienceblog.com)
- The neutron radiation used in the treatment is provided by VTT. (scienceblog.com)
Atoms4
- When the manipulated neutrons smashed into the target, they interacted with the protons within the liquid hydrogen's atoms, sending out gamma rays that were measured by special sensors. (ornl.gov)
- The atoms in neutron stars have been squeezed so tightly by gravity that they have broken down, the protons and electrons inside them smushing together to create neutrons, leaving objects the size of small cities that contain masses larger than the sun. (scientificamerican.com)
- Ben - ISIS can be used as a type of microscope to image the positions and dynamics of atoms, but it's also ideal for seeing how neutrons themselves interact with systems. (thenakedscientists.com)
- Cancer is subsequently irradiated with neutrons obtained from a nuclear reactor, which causes boron atoms to split within the cancerous tissue as a result from a boron neutron capture reaction. (scienceblog.com)
Ultracold2
- Ultracold neutrons (UCN) are free neutrons which can be stored in traps made from certain materials. (wikipedia.org)
- Ultracold neutrons move so slowly that it is possible to trap them using 'bottles' made of magnetic fields, ordinary matter and even gravity. (technologyreview.com)
Measurements5
- Furthermore, while the science team knew that neutron spectroscopy measurements were key to making progress on plutonium's "missing" magnetism, the analysis of previous neutron efforts by other teams taught them their sample needed to be improved in two unique ways: First, typically available plutonium predominantly consists of the isotope plutonium-239, which is highly absorbent of neutrons and would obscure the weak signal they sought. (sciencedaily.com)
- Experiments involve precision measurements of symmetries and parameters of the "weak" nuclear interaction, including measurement of the lifetime of neutrons using thermal and ultra-cold neutron improved cold neutron counting techniques, setting a limit on the time-reversal asymmetry coefficient, and radiative decay of the neutron. (nist.gov)
- International comparisons of neutron source measurements are held regularly and NPL has always demonstrated excellent agreement with other laboratories. (npl.co.uk)
- Physicists seek accurate measurements of neutron stars' masses and radii, which would help reveal their "equation of state"-the relationship between pressure and density within these stars. (scientificamerican.com)
- In a new study, an international team of researchers combined gravitational wave measurements from two neutron star collisions, as well as the light signals that arrived along with one of them (the other was dark), with estimates of neutron star masses and radii from watching rapidly spinning neutron stars called pulsars. (scientificamerican.com)
Supernova explosions1
- Interpreting high-energy, astrophysical phenomena, such as supernova explosions or neutron-star collisions, requires a robust understanding of matter at supranuclear densities. (nature.com)
Quarks3
- the strong interaction confines quarks in neutrons and protons. (ornl.gov)
- Do neutrons break down further into their constituent quarks and gluons? (scientificamerican.com)
- If, on the other hand, the neutrons break down into a soup of quarks, the core would be squishier and the whole star would sink in a bit, resulting in a smaller radius. (scientificamerican.com)
Beams3
- We collaborated on tests at the Insitut Laue Langevin (ILL) to study the effects of high flux neutron beams on spin-exchange optical pumping (SEOP). (nist.gov)
- For example, I designed neutron guide shutters, which pneumatically raise and lower shielding material to open and close several neutron beams. (bls.gov)
- Since the interactions in the high-temperature superconductors are so strong, measurement of these materials' spin waves requires beams of energetic neutrons that were unavailable to the research community at this intensity before the SNS," Abernathy said. (scienceblog.com)
Spin5
- The magnetic moment of the neutron, produced by its spin, interacts with magnetic fields. (wikipedia.org)
- We are developing and promoting the applications of efficient neutron spin filters based on laser-polarized He-3. (nist.gov)
- They measured a 30 parts per billion preference for gamma rays to be emitted antiparallel to the neutron spin when neutrons are captured by protons in liquid hydrogen. (ornl.gov)
- The apparatus was designed to control the spin direction of the slow-moving neutrons, "flipping" them from spin-up to spin-down positions as desired. (ornl.gov)
- Another thing: Neutron stars spin like nobody's watching. (howstuffworks.com)
Scientists5
- Scientists would like to have a solid number for the neutron lifetime to plug into these equations. (energy.gov)
- But scientists can't put timers on neutrons to see how fast they fall apart. (energy.gov)
- Scientists have come a step closer to understanding the inner workings of these bizarre bodies by studying the light and gravitational waves that result when two neutron stars slam into each other and become a black hole. (scientificamerican.com)
- Scientists only gained the ability to detect gravitational waves in 2015, and have spotted just a handful of events involving neutron stars so far (the others have been collisions of black holes). (scientificamerican.com)
- It aims at bringing together neutron young scientists from around the world to share their work, interact and exchange ideas in a friendly and stimulating environment to build a strong collaborative network. (grc.org)
Paul Scherrer1
- Talk given at the AIC Information Day on "Large Facilities for Crystallography Studies: Synchrotron and Neutron sources" October 19th, 2009 , Paul Scherrer Institut, Villigen, Switzerland. (psi.ch)
Particles called1
- It is these elusive particles called neutrons that hold hidden secrets about our mysterious 35-neutron element! (dane101.com)
Magnetic10
- This diagram of a pulsar shows the neutron star with a strong magnetic field (field lines shown in blue) and a beam of light along the magnetic axis. (nasa.gov)
- As the neutron star spins, the magnetic field spins with it, sweeping that beam through space. (nasa.gov)
- More often, though, neutron stars are found spinning wildly with extreme magnetic fields as pulsars or magnetars. (nasa.gov)
- The video below is an animation of a neutron star showing the magnetic field rotating with the star. (nasa.gov)
- In all neutron stars, the crust of the star is locked together with the magnetic field so that any change in one affects the other. (nasa.gov)
- Non-magnetic materials such as DLC are usually preferred for the use with polarized neutrons. (wikipedia.org)
- pm \mu _{N}\cdot B} where μ N {\displaystyle \mu _{N}} is the magnetic moment of the neutron and B = μ 0 ⋅ M {\displaystyle B=\mu _{0}\cdot M} the magnetic field created on the surface by the magnetization. (wikipedia.org)
- Neutrons are uniquely suited to this research as they are able to detect magnetic fluctuations. (sciencedaily.com)
- Then: Even run-of-the-mill neutron stars have magnetic fields 10 million times stronger than Earth. (howstuffworks.com)
- If a super-magnetically charged neutron star (those that have a magnetic field a quadrillion times stronger than ours) floated even 100,000 miles (160,934 kilometers) near us? (howstuffworks.com)
Nuclei5
- The reflection is caused by the coherent strong interaction of the neutron with atomic nuclei. (wikipedia.org)
- The manganese nuclei capture neutrons to form an unstable isotope of manganese ( 56 Mn) which decays with the emission of a gamma ray. (npl.co.uk)
- Corrections are made for neutrons escaping from the bath and for those captured by other nuclei in the solution and in the source mounting assembly. (npl.co.uk)
- Although atomic nuclei aren't quite as densely packed as neutron stars, they are easier to observe and can still give insight into the inner workings of some of the most extreme objects in the universe. (astronomy.com)
- These isotopes contain varying numbers of neutrons in their nuclei while sharing the same number of protons. (dane101.com)
Researchers1
- But thanks to a recent study by a team of researchers from Goethe University in Frankfurt, Germany, it may now be possible to determine the absolute maximum mass that is required for a neutron star to collapse, giving birth to a new black hole. (universetoday.com)
Physicists3
- So physicists measure the rate at which the neutrons hit the bottle walls and how quickly this drops. (technologyreview.com)
- And just long enough to confound nuclear physicists studying the lifetime of the neutron. (energy.gov)
- Some 95 percent of the mass of a neutron star is pure neutrons, but physicists wonder what happens at the very center, where the density peaks. (scientificamerican.com)
Detection3
- In addition, we are developing advanced liquid scintillation neutron spectrometry techniques for characterization of neutron fields and for detection of concealed neutron sources with low false-positive rates. (nist.gov)
- Monte-Carlo nuclear particle (MCNP) code simulations were initially used to calculate the neutron detection efficiency in the microstructured diodes as a function of geometry and pitch. (bvsalud.org)
- This results in large neutron detection areas and enhanced neutron detection efficiency when compared with planar detectors. (bvsalud.org)
IZotope2
- A slice of iZotope fan favorite, Trash, is now in Neutron 4. (izotope.com)
- Learn how to clean up a muddy mix and how to make space for your instruments with the new Unmask feature and other unmasking techniques in iZotope Neutron. (izotope.com)
Decay4
- One reason to do this is to measure how quickly the neutrons decay by beta emission. (technologyreview.com)
- That leaves open the possibility that there might be a third process at work: that some of the extra decay might be the result of neutrons jumping from our universe to another. (technologyreview.com)
- It could be revealing an unknown process in neutron decay. (energy.gov)
- Instead, they find ways to measure neutrons before and after they decay to calculate the lifetime. (energy.gov)
Plutonium2
- The team used plutonium-242 instead, an isotope that absorbs far fewer neutrons. (sciencedaily.com)
- When hit by a slow neutron-a neat trick performed in nuclear reactors-it undergoes transmutation, transforming into plutonium-242 ^8 . (dane101.com)
Experiments2
Densities2
- However, these observations mainly probe the EOS at densities \(\gtrsim 2{n}_{{\rm{sat}}}\) and still carry considerable uncertainties, reflected in the ranges for predictions of neutron-star radii. (nature.com)
- And it's likely this trend extends all the way up to objects with neutron densities as high as those found in neutron stars. (astronomy.com)
Laboratory1
- Europe has the two best neutron sources currently a 'steady-state reactor' at Grenoble, France, and the ISIS spallation source at Rutherford Laboratory near Oxford, England. (pravda.ru)
Instrumentation1
- Detailed reports were given on the technical and scientific challenges in recent months concerning the conceptual layout of potential facilities, the accelerator techniques required, neutron target development and neutron instrumentation. (fz-juelich.de)
Measurement1
- The new measurement is in general agreement with earlier studies that have looked at gravitational wave data and other ways to measure neutron star size. (scientificamerican.com)
Newly-created1
- If the core of the collapsing star is between about 1 and 3 solar masses, these newly-created neutrons can stop the collapse, leaving behind a neutron star. (nasa.gov)
Centers2
- A handful of neutron stars have been found sitting at the centers of supernova remnants quietly emitting X-rays. (nasa.gov)
- This enigma centers around an elemental quest: which element has exactly 35 neutrons ? (dane101.com)
Fundamental1
- The seminar targets exotic materials and couplings where neutron investigations of the structure and dynamics, in the bulk and at interfaces, reveal fundamental mechanisms leading to outstanding properties foreseen for immediate or future applications. (grc.org)
Sources5
- From Denmark to Japan, the UK, France and Sweden, Ken Andersen has worked at neutron sources around the world. (ornl.gov)
- It measures the number of neutrons per second emitted by sealed radionuclide neutron sources such as 241 Am-Be and 252 Cf. The sources can then be used to calibrate neutron sensitive devices such as area survey instruments and personal dosemeters. (npl.co.uk)
- RIKEN has developed accelerator-driven compact pulse neutron systems for practical use of industrial applications and infrastructure non-destructive inspection with the names of RANS (RIKEN Accelerator-driven compact neutron sources). (riken.jp)
- They were welcomed by Prof. Thomas Brückel, director at JCNS, who gave an overview of previous meetings and the significant progress which has already been made to develop compact and high brilliance neutron sources over the last few years. (fz-juelich.de)
- Trace quantities of americium are widely used in smoke detectors, and as neutron sources in neutron moisture gauges. (cdc.gov)
Atomic1
- Each element has its own unique set of properties, including its atomic number, atomic mass, and number of neutrons. (dane101.com)
Theoretical2
- Theoretical mass-radius relations for neutron-star models with different equations-of-state (black lines) and a strange-quark star (black dash-dotted). (uni-tuebingen.de)
- In this 2-day workshop, we want to invite experts in Galactic Archaeology to discuss what we can learn, both about the Milky Way and its components, from observations and theoretical models, with a focus on the heavy neutron-capture elements. (lu.se)
Thermal2
- In addition to the isolated neutron stars, we also can observe thermal surface emission from Central Compact Objects (CCOs) in supernova remnants. (uni-tuebingen.de)
- B Conformal Doping for Highly Efficient Thermal Neutron Detectors. (bvsalud.org)
Equation of st2
- Knowing the neutron star equation of state would in turn indicate what kind of matter hides inside them. (scientificamerican.com)
- The equation of state they derived predicted that a neutron star containing the mass of 1.4 suns would have a radius of about 11.75 kilometers, plus or minus .81 to .86 km. (scientificamerican.com)
Source8
- The neutron source is placed inside a large spherical bath containing almost 500 litres of manganese sulphate solution. (npl.co.uk)
- A neutron source calibration service is offered to customers from around the world many of which are themselves national standards laboratories. (npl.co.uk)
- When using a radionuclide neutron source to calibrate an instrument or a dosemeter, in addition to knowing the neutron emission rate of the source, the degree to which the source emission is not isotropic, or the same in all directions, also has to be known. (npl.co.uk)
- Planned since the 1980s, SNS is the first neutron source built in the United States in more than 30 years. (pravda.ru)
- The neutrons are generated through cosmic rays and these cosmic rays are from the galactic source. (thenakedscientists.com)
- Chris - Well, what we're able to do is that we have a neutron source and that neutron source thankfully, can mimic the spectrum of neutrons. (thenakedscientists.com)
- The progress of these activities will be discussed at the next High Brilliance Neutron Source Workshop in autumn 2019. (fz-juelich.de)
- The higher efficiency is enabled by the 10B acting as a source for conformal doping in the trenches , resulting in lower leakage current while also enabling neutron sensitivity in the microstructured diodes. (bvsalud.org)