Radioisotope Dilution Technique
Carbon monoxide (CO). A poisonous colorless, odorless, tasteless gas. It combines with hemoglobin to form carboxyhemoglobin, which has no oxygen carrying capacity. The resultant oxygen deprivation causes headache, dizziness, decreased pulse and respiratory rates, unconsciousness, and death. (From Merck Index, 11th ed)
The production of an image obtained by cameras that detect the radioactive emissions of an injected radionuclide as it has distributed differentially throughout tissues in the body. The image obtained from a moving detector is called a scan, while the image obtained from a stationary camera device is called a scintiphotograph.
The first artificially produced element and a radioactive fission product of URANIUM. Technetium has the atomic symbol Tc, atomic number 43, and atomic weight 98.91. All technetium isotopes are radioactive. Technetium 99m (m=metastable) which is the decay product of Molybdenum 99, has a half-life of about 6 hours and is used diagnostically as a radioactive imaging agent. Technetium 99 which is a decay product of technetium 99m, has a half-life of 210,000 years.
Carbon Monoxide Poisoning
Technetium Tc 99m Sulfur Colloid
Diagnostic Techniques, Radioisotope
Radiotherapy where cytotoxic radionuclides are linked to antibodies in order to deliver toxins directly to tumor targets. Therapy with targeted radiation rather than antibody-targeted toxins (IMMUNOTOXINS) has the advantage that adjacent tumor cells, which lack the appropriate antigenic determinants, can be destroyed by radiation cross-fire. Radioimmunotherapy is sometimes called targeted radiotherapy, but this latter term can also refer to radionuclides linked to non-immune molecules (see RADIOTHERAPY).
Liquid, solid, or gaseous waste resulting from mining of radioactive ore, production of reactor fuel materials, reactor operation, processing of irradiated reactor fuels, and related operations, and from use of radioactive materials in research, industry, and medicine. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)
Serum Albumin, Radio-Iodinated
Tungsten. A metallic element with the atomic symbol W, atomic number 74, and atomic weight 183.85. It is used in many manufacturing applications, including increasing the hardness, toughness, and tensile strength of steel; manufacture of filaments for incandescent light bulbs; and in contact points for automotive and electrical apparatus.
Heterocyclic Compounds, 1-Ring
Sodium Pertechnetate Tc 99m
Accumulation of a drug or chemical substance in various organs (including those not relevant to its pharmacologic or therapeutic action). This distribution depends on the blood flow or perfusion rate of the organ, the ability of the drug to penetrate organ membranes, tissue specificity, protein binding. The distribution is usually expressed as tissue to plasma ratios.
Technetium Tc 99m Pentetate
The amount of radiation energy that is deposited in a unit mass of material, such as tissues of plants or animal. In RADIOTHERAPY, radiation dosage is expressed in gray units (Gy). In RADIOLOGIC HEALTH, the dosage is expressed by the product of absorbed dose (Gy) and quality factor (a function of linear energy transfer), and is called radiation dose equivalent in sievert units (Sv).
An imaging technique using compounds labelled with short-lived positron-emitting radionuclides (such as carbon-11, nitrogen-13, oxygen-15 and fluorine-18) to measure cell metabolism. It has been useful in study of soft tissues such as CANCER; CARDIOVASCULAR SYSTEM; and brain. SINGLE-PHOTON EMISSION-COMPUTED TOMOGRAPHY is closely related to positron emission tomography, but uses isotopes with longer half-lives and resolution is lower.
Vitamin B 12
A cobalt-containing coordination compound produced by intestinal micro-organisms and found also in soil and water. Higher plants do not concentrate vitamin B 12 from the soil and so are a poor source of the substance as compared with animal tissues. INTRINSIC FACTOR is important for the assimilation of vitamin B 12.
Sentinel Lymph Node Biopsy
Technetium Tc 99m Medronate
Evaluation Studies as Topic
A dark powdery deposit of unburned fuel residues, composed mainly of amorphous CARBON and some HYDROCARBONS, that accumulates in chimneys, automobile mufflers and other surfaces exposed to smoke. It is the product of incomplete combustion of carbon-rich organic fuels in low oxygen conditions. It is sometimes called lampblack or carbon black and is used in INK, in rubber tires, and to prepare CARBON NANOTUBES.
Sensitivity and Specificity
Molecular Sequence Data
Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories.
A metallic element of atomic number 30 and atomic weight 65.38. It is a necessary trace element in the diet, forming an essential part of many enzymes, and playing an important role in protein synthesis and in cell division. Zinc deficiency is associated with ANEMIA, short stature, HYPOGONADISM, impaired WOUND HEALING, and geophagia. It is known by the symbol Zn.
Cell surface proteins that bind somatostatin and trigger intracellular changes which influence the behavior of cells. Somatostatin is a hypothalamic hormone, a pancreatic hormone, and a central and peripheral neurotransmitter. Activated somatostatin receptors on pituitary cells inhibit the release of growth hormone; those on endocrine and gastrointestinal cells regulate the absorption and utilization of nutrients; and those on neurons mediate somatostatin's role as a neurotransmitter.
Metabolic Clearance Rate
Chromatography, High Pressure Liquid
A method of measuring the effects of a biologically active substance using an intermediate in vivo or in vitro tissue or cell model under controlled conditions. It includes virulence studies in animal fetuses in utero, mouse convulsion bioassay of insulin, quantitation of tumor-initiator systems in mouse skin, calculation of potentiating effects of a hormonal factor in an isolated strip of contracting stomach muscle, etc.
Any liquid or solid preparation made specifically for the growth, storage, or transport of microorganisms or other types of cells. The variety of media that exist allow for the culturing of specific microorganisms and cell types, such as differential media, selective media, test media, and defined media. Solid media consist of liquid media that have been solidified with an agent such as AGAR or GELATIN.
Tomography, Emission-Computed, Single-Photon
A method of computed tomography that uses radionuclides which emit a single photon of a given energy. The camera is rotated 180 or 360 degrees around the patient to capture images at multiple positions along the arc. The computer is then used to reconstruct the transaxial, sagittal, and coronal images from the 3-dimensional distribution of radionuclides in the organ. The advantages of SPECT are that it can be used to observe biochemical and physiological processes as well as size and volume of the organ. The disadvantage is that, unlike positron-emission tomography where the positron-electron annihilation results in the emission of 2 photons at 180 degrees from each other, SPECT requires physical collimation to line up the photons, which results in the loss of many available photons and hence degrades the image.
Carbon Compounds, Inorganic
The synthesis by organisms of organic chemical compounds, especially carbohydrates, from carbon dioxide using energy obtained from light rather than from the oxidation of chemical compounds. Photosynthesis comprises two separate processes: the light reactions and the dark reactions. In higher plants; GREEN ALGAE; and CYANOBACTERIA; NADPH and ATP formed by the light reactions drive the dark reactions which result in the fixation of carbon dioxide. (from Oxford Dictionary of Biochemistry and Molecular Biology, 2001)
Bone and Bones
A chemical reaction in which an electron is transferred from one molecule to another. The electron-donating molecule is the reducing agent or reductant; the electron-accepting molecule is the oxidizing agent or oxidant. Reducing and oxidizing agents function as conjugate reductant-oxidant pairs or redox pairs (Lehninger, Principles of Biochemistry, 1982, p471).
Reproducibility of Results
The statistical reproducibility of measurements (often in a clinical context), including the testing of instrumentation or techniques to obtain reproducible results. The concept includes reproducibility of physiological measurements, which may be used to develop rules to assess probability or prognosis, or response to a stimulus; reproducibility of occurrence of a condition; and reproducibility of experimental results.
The processes by which organisms use simple inorganic substances such as gaseous or dissolved carbon dioxide and inorganic nitrogen as nutrient sources. Contrasts with heterotrophic processes which make use of organic materials as the nutrient supply source. Autotrophs can be either chemoautotrophs (or chemolithotrophs), largely ARCHAEA and BACTERIA, which also use simple inorganic substances for their metabolic energy reguirements; or photoautotrophs (or photolithotrophs), such as PLANTS and CYANOBACTERIA, which derive their energy from light. Depending on environmental conditions some organisms can switch between different nutritional modes (autotrophy; HETEROTROPHY; chemotrophy; or PHOTOTROPHY) to utilize different sources to meet their nutrient and energy requirements.
Any of various animals that constitute the family Suidae and comprise stout-bodied, short-legged omnivorous mammals with thick skin, usually covered with coarse bristles, a rather long mobile snout, and small tail. Included are the genera Babyrousa, Phacochoerus (wart hogs), and Sus, the latter containing the domestic pig (see SUS SCROFA).
Nucleic Acid Hybridization
Widely used technique which exploits the ability of complementary sequences in single-stranded DNAs or RNAs to pair with each other to form a double helix. Hybridization can take place between two complimentary DNA sequences, between a single-stranded DNA and a complementary RNA, or between two RNA sequences. The technique is used to detect and isolate specific sequences, measure homology, or define other characteristics of one or both strands. (Kendrew, Encyclopedia of Molecular Biology, 1994, p503)
Heme Oxygenase (Decyclizing)
A deoxyribonucleotide polymer that is the primary genetic material of all cells. Eukaryotic and prokaryotic organisms normally contain DNA in a double-stranded state, yet several important biological processes transiently involve single-stranded regions. DNA, which consists of a polysugar-phosphate backbone possessing projections of purines (adenine and guanine) and pyrimidines (thymine and cytosine), forms a double helix that is held together by hydrogen bonds between these purines and pyrimidines (adenine to thymine and guanine to cytosine).
Magnetic Resonance Spectroscopy
Citric Acid Cycle
Tomography, X-Ray Computed
A mass of organic or inorganic solid fragmented material, or the solid fragment itself, that comes from the weathering of rock and is carried by, suspended in, or dropped by air, water, or ice. It refers also to a mass that is accumulated by any other natural agent and that forms in layers on the earth's surface, such as sand, gravel, silt, mud, fill, or loess. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed, p1689)
Magnetic Resonance Imaging
A basic element found in nearly all organized tissues. It is a member of the alkaline earth family of metals with the atomic symbol Ca, atomic number 20, and atomic weight 40. Calcium is the most abundant mineral in the body and combines with phosphorus to form calcium phosphate in the bones and teeth. It is essential for the normal functioning of nerves and muscles and plays a role in blood coagulation (as factor IV) and in many enzymatic processes.
One of the three domains of life (the others being Eukarya and ARCHAEA), also called Eubacteria. They are unicellular prokaryotic microorganisms which generally possess rigid cell walls, multiply by cell division, and exhibit three principal forms: round or coccal, rodlike or bacillary, and spiral or spirochetal. Bacteria can be classified by their response to OXYGEN: aerobic, anaerobic, or facultatively anaerobic; by the mode by which they obtain their energy: chemotrophy (via chemical reaction) or PHOTOTROPHY (via light reaction); for chemotrophs by their source of chemical energy: CHEMOLITHOTROPHY (from inorganic compounds) or chemoorganotrophy (from organic compounds); and by their source for CARBON; NITROGEN; etc.; HETEROTROPHY (from organic sources) or AUTOTROPHY (from CARBON DIOXIDE). They can also be classified by whether or not they stain (based on the structure of their CELL WALLS) with CRYSTAL VIOLET dye: gram-negative or gram-positive.
Gene Expression Regulation, Bacterial
Oceans and Seas
Sensitivity of [11C]phenylephrine kinetics to monoamine oxidase activity in normal human heart. (1/5742)Phenylephrine labeled with 11C was developed as a radiotracer for imaging studies of cardiac sympathetic nerves with PET. A structural analog of norepinephrine, (-)-[11C]phenylephrine (PHEN) is transported into cardiac sympathetic nerve varicosities by the neuronal norepinephrine transporter and stored in vesicles. PHEN is also a substrate for monoamine oxidase (MAO). The goal of this study was to assess the importance of neuronal MAO activity on the kinetics of PHEN in the normal human heart. MAO metabolism of PHEN was inhibited at the tracer level by substituting deuterium atoms for the two hydrogen atoms at the alpha-carbon side chain position to yield the MAO-resistant analog D2-PHEN. METHODS: Paired PET studies of PHEN and D2-PHEN were performed in six normal volunteers. Hemodynamic and electrocardiographic responses were monitored. Blood levels of intact radiotracer and radiolabeled metabolites were measured in venous samples taken during the 60 min dynamic PET study. Myocardial retention of the tracers was regionally quantified as a retention index. Tracer efflux between 6 and 50 min after tracer injection was fit to a single exponential process to obtain a washout half-time for all left ventricular regions. RESULTS: Although initial heart uptake of the two tracers was similar, D2-PHEN cleared from the heart 2.6 times more slowly than PHEN (mean half-time 155+/-52 versus 55+/-10 min, respectively; P < 0.01). Correspondingly, heart retention of D2-PHEN at 40-60 min after tracer injection was higher than PHEN (mean retention indices 0.086+/-0.018 versus 0.066+/-0.011 mL blood/ min/mL tissue, respectively; P < 0.003). CONCLUSION: Efflux of radioactivity from normal human heart after uptake of PHEN is primarily due to metabolism of the tracer by neuronal MAO. Related mechanistic studies in the isolated rat heart indicate that vesicular storage of PHEN protects the tracer from rapid metabolism by neuronal MAO, suggesting that MAO metabolism of PHEN leaking from storage vesicles leads to the gradual loss of PHEN from the neurons. Thus, although MAO metabolism influences the rate of clearance of PHEN from the neurons, MAO metabolism is not the rate-determining step in the observed efflux rate under normal conditions. Rather, the rate at which PHEN leaks from storage vesicles is likely to be the rate-limiting step in the observed efflux rate. (+info)
Reproducibility studies with 11C-DTBZ, a monoamine vesicular transporter inhibitor in healthy human subjects. (2/5742)The reproducibility of (+/-)-alpha-[11C] dihydrotetrabenazine (DTBZ) measures in PET was studied in 10 healthy human subjects, aged 22-76 y. METHODS: The scan-to-scan variation of several measures used in PET data analysis was determined, including the radioactivity ratio (target-to-reference), plasma-input Logan total distribution volume (DV), plasma-input Logan Bmax/Kd and tissue-input Logan Bmax/Kd values. RESULTS: The radioactivity ratios, plasma-input Bmax/Kd and tissue-input Bmax/Kd all have higher reliability than plasma-input total DV values. In addition, measures using the occipital cortex as the reference region have higher reliability than the same measures using the cerebellum as the reference region. CONCLUSION: Our results show that DTBZ is a reliable PET tracer that provides reproducible in vivo measurement of striatal vesicular monoamine transporter density. In the selection of reference regions for DTBZ PET data analysis, caution must be exercised in circumstances when DTBZ binding in the occipital cortex or the cerebellum may be altered. (+info)
Influence of vesicular storage and monoamine oxidase activity on [11C]phenylephrine kinetics: studies in isolated rat heart. (3/5742)[11C]Phenylephrine (PHEN) is a radiolabeled analogue of norepinephrine that is transported into cardiac sympathetic nerve varicosities by the neuronal norepinephrine transporter and taken up into storage vesicles localized within the nerve varicosities by the vesicular monoamine transporter. PHEN is structurally related to two previously developed sympathetic nerve markers: [11C]-meta-hydroxyephedrine and [11C]epinephrine. To better characterize the neuronal handling of PHEN, particularly its sensitivity to neuronal monoamine oxidase (MAO) activity, kinetic studies in an isolated working rat heart system were performed. METHODS: Radiotracer was administered to the isolated working heart as a 10-min constant infusion followed by a 110-min washout period. Two distinctly different approaches were used to assess the sensitivity of the kinetics of PHEN to MAO activity. In the first approach, oxidation of PHEN by MAO was inhibited at the enzymatic level with the MAO inhibitor pargyline. In the second approach, the two hydrogen atoms on the a-carbon of the side chain of PHEN were replaced with deuterium atoms ([11C](-)-alpha-alpha-dideutero-phenylephrine [D2-PHEN]) to inhibit MAO activity at the tracer level. The importance of vesicular uptake on the kinetics of PHEN and D2-PHEN was assessed by inhibiting vesicular monoamine transporter-mediated storage into vesicles with reserpine. RESULTS: Under control conditions, PHEN initially accumulated into the heart at a rate of 0.72+/-0.15 mL/min/g wet. Inhibition of MAO activity with either pargyline or di-deuterium substitution did not significantly alter this rate. However, MAO inhibition did significantly slow the clearance of radioactivity from the heart during the washout phase of the study. Blocking vesicular uptake with reserpine reduced the initial uptake rates of PHEN and D2-PHEN, as well as greatly accelerated the clearance of radioactivity from the heart during washout. CONCLUSION: These studies indicate that PHEN kinetics are sensitive to neuronal MAO activity. Under normal conditions, efficient vesicular storage of PHEN serves to protect the tracer from rapid metabolism by neuronal MAO. However, it is likely that leakage of PHEN from the storage vesicles and subsequent metabolism by MAO lead to an appreciable clearance of radioactivity from the heart. (+info)
Regional patterns of myocardial sympathetic denervation in dilated cardiomyopathy: an analysis using carbon-11 hydroxyephedrine and positron emission tomography. (4/5742)OBJECTIVE: To assess presynaptic function of cardiac autonomic innervation in patients with advanced congestive heart failure using positron emission tomography (PET) and the recently developed radiolabelled catecholamine analogue carbon-11 hydroxyephedrine (HED) as a marker for neuronal catecholamine uptake function. DESIGN AND PATIENTS: 29 patients suffering from dilated cardiomyopathy with moderate to severe heart failure were compared with eight healthy controls. Perfusion scan was followed by HED dynamic PET imaging of cardiac sympathetic innervation. The scintigraphic results were compared with markers of disease severity and the degree of sympathetic dysfunction assessed by means of heart rate variability. RESULTS: In contrast to nearly normal perfusions, mean (SD) HED retention in dilated cardiomyopathy patients was abnormal in 64 (32)% of the left ventricle. Absolute myocardial HED retention was 10.7 (1.0)%/min in controls v 6.2 (1.6)%/min in dilated cardiomyopathy patients (p < 0.001). Moreover, significant regional reduction of HED retention was demonstrated in apical and inferoapical segments. HED retention was significantly correlated with New York Heart Association functional class (r = -0.55, p = 0. 002) and ejection fraction (r = 0.63, p < 0.001), but not, however, with plasma noradrenaline concentrations as well as parameters of heart rate variability. CONCLUSIONS: In this study, using PET in combination with HED in patients with dilated cardiomyopathy, not only global reduction but also regional abnormalities of cardiac sympathetic tracer uptake were demonstrated. The degree of abnormality was positively correlated to markers of severity of heart failure. The pathogenetic mechanisms leading to the regional differences of neuronal damage as well as the prognostic significance of these findings remain to be defined. (+info)
Measurement of striatal D2 dopamine receptor density and affinity with [11C]-raclopride in vivo: a test-retest analysis. (5/5742)Subacute and long-term stability of measurements of D2 dopamine receptor density (Bmax), affinity (Kd) was studied with positron emission tomography in eight healthy male volunteers. [11C]-Raclopride and the transient equilibrium method were used to measure D2 receptor characteristics. The interval between measurements (scan pairs) was 3 to 7 weeks (subacute) for four subjects and 6 to 11 months (long-term) for four subjects. A test-retest analysis of quantitative measurements of D2 receptor Bmax and Kd was compared with that done on binding potential (BP, Bmax/Kd) measures. In addition, the effect of error in defining the transient equilibrium time (tmax) in the parameter estimation procedure was explored with simulations. The subacute test-retest indicates good reproducibility of D2 receptor density, affinity, and BP ratio measurements with intraclass correlation coefficients of 0.90, 0.96, and 0.86, respectively. The variability of the measurements after 6 to 11 months was slightly higher than that seen in a subacute testing for Kd and more clearly so for binding potential and Bmax. The absolute variability in Bmax (14.5%) measurements was consistently higher than that of Kd (8.4%) or BP (7.9%) both in subacute and long-term measurements. Simulations indicated that the Bmax and Kd estimation procedure is more sensitive to error in the tmax than that for the BP. The results indicate a good overall stability of the equilibrium method with [11C]raclopride for measuring dopamine D2 receptor binding characteristics in the striatum. The BP approach is more stable than Kd and especially Bmax measurements. Error in defining the tmax in particular in the low specific radioactivity scan may be one source of greater variability in Bmax versus BP. However, a higher intraindividual variability in measurements of the D2 receptor Bmax also may include a component of continuous regulation of this parameter over time. These methodologic aspects should be considered in the design and interpretation of longitudinal studies on D2 dopamine receptor characteristics with [11C]-raclopride. (+info)
Novel, highly lipophilic antioxidants readily diffuse across the blood-brain barrier and access intracellular sites. (6/5742)In an accompanying article, an in vitro assay for permeability predicts that membrane-protective, antioxidant 2,4-diamino-pyrrolo[2, 3-d]pyrimidines should have improved blood-brain barrier (BBB) permeation over previously described lipophilic antioxidants. Using a first-pass extraction method and brain/plasma quantification, we show here that two of the pyrrolopyrimidines, one of which is markedly less permeable, readily partition into rat brain. The efficiency of extraction was dependent on serum protein binding, and in situ efflux confirms the in vitro data showing that PNU-87663 is retained in brain longer than PNU-89843. By exploiting inherent fluorescence properties of PNU-87663, its distribution within brain and within cells in culture was demonstrated using confocal scanning laser microscopy. PNU-87663 rapidly partitioned into the cell membrane and equilibrates with cytoplasmic compartments via passive diffusion. Although partitioning of PNU-87663 favors intracytoplasmic lipid storage droplets, the compound was readily exchangeable as shown by efflux of compound from cells to buffer when protein was present. The results demonstrated that pyrrolopyrimidines were well suited for quickly accessing target cells within the central nervous system as well as in other target tissues. (+info)
Absorption, metabolism, and excretion of 14C-temozolomide following oral administration to patients with advanced cancer. (7/5742)The purpose of this study is to characterize the absorption, metabolism, and excretion of carbon 14-labeled temozolomide (14C-TMZ) administered p.o. to adult patients with advanced solid malignancies. On day 1 of cycle 1, six patients received a single oral 200-mg dose of 14C-TMZ (70.2 microCi). Whole blood, plasma, urine, and feces were collected from days 1-8 and on day 14 of cycle 1. Total radioactivity was measured in all samples. TMZ, 5-(3-methyltriazen-1-yl)imidazole-4-carboxamide (MTIC), and 4-amino-5-imidazole-carboxamide (AIC) concentrations were determined in plasma, and urine and plasma samples were profiled for metabolite/degradation products. Maximum TMZ plasma concentrations were achieved between 0.33 to 2 h (mean, 1.2 h), and half-life, apparent volume of distribution, and oral clearance values averaged 1.9 h, 17 liters/m2, and 104 ml/min/m2, respectively. A first-order absorption, one-compartment linear model, which included first-order formation of MTIC from TMZ and elimination of MTIC via degradation to AIC, and a peripheral distribution compartment for AIC, adequately described the plasma TMZ, MTIC, and AIC concentrations. MTIC systemic clearance was estimated to be 5384 ml/min/m2, and the half-life was calculated to be 2.5 min. Metabolite profiles of plasma at 1 and 4 h after treatment showed that 14C-derived radioactivity was primarily associated with TMZ, and a smaller amount was attributed to AIC. Profiles of urine samples from 0-24 h revealed that 14C-TMZ-derived urinary radioactivity was primarily associated with unchanged drug (5.6%), AIC (12%), or 3-methyl-2,3-dihydro-4-oxoimidazo[5,1-d]tetrazine-8-carboxyl ic acid (2.3%). The recovered radioactive dose (39%) was principally eliminated in the urine (38%), and a small amount (0.8%) was excreted in the feces. TMZ exhibits rapid oral absorption and high systemic availability. The primary elimination pathway for TMZ is by pH-dependent degradation to MTIC and further degradation to AIC. Incomplete recovery of radioactivity may be explained by the incorporation of AIC into nucleic acids. (+info)
Genetic evidence for ATP-dependent endoplasmic reticulum-to-Golgi apparatus trafficking of ceramide for sphingomyelin synthesis in Chinese hamster ovary cells. (8/5742)LY-A strain is a Chinese hamster ovary cell mutant resistant to sphingomyelin (SM)-directed cytolysin and has a defect in de novo SM synthesis. Metabolic labeling experiments with radioactive serine, sphingosine, and choline showed that LY-A cells were defective in synthesis of SM from these precursors, but not syntheses of ceramide (Cer), glycosphingolipids, or phosphatidylcholine, indicating a specific defect in the conversion of Cer to SM in LY-A cells. In vitro experiments showed that the specific defect of SM formation in LY-A cells was not due to alterations in enzymatic activities responsible for SM synthesis or degradation. When cells were treated with brefeldin A, which causes fusion of the Golgi apparatus with the endoplasmic reticulum (ER), de novo SM synthesis in LY-A cells was restored to the wild-type level. Pulse-chase experiments with a fluorescent Cer analogue, N-(4,4-difluoro-5,7-dimethyl-4-bora-3a, 4a-diaza-s-indacene-3-pentanoyl)-D-erythro-sphingosine (C5-DMB-Cer), revealed that in wild-type cells C5-DMB-Cer was redistributed from intracellular membranes to the Golgi apparatus in an intracellular ATP-dependent manner, and that LY-A cells were defective in the energy-dependent redistribution of C5-DMB-Cer. Under ATP-depleted conditions, conversion of C5-DMB-Cer to C5-DMB-SM and of [3H]sphingosine to [3H]SM in wild-type cells decreased to the levels in LY-A cells, which were not affected by ATP depletion. ER-to-Golgi apparatus trafficking of glycosylphosphatidylinositol-anchored or membrane-spanning proteins in LY-A cells appeared to be normal. These results indicate that the predominant pathway of ER-to-Golgi apparatus trafficking of Cer for de novo SM synthesis is ATP dependent and that this pathway is almost completely impaired in LY-A cells. In addition, the specific defect of SM synthesis in LY-A cells suggests different pathways of Cer transport for glycosphingolipids versus SM synthesis. (+info)
Graphical analysis of reversible radioligand binding from time-activity measurements applied to [N-11C-methyl]-(-)-cocaine PET...
A graphical method of analysis applicable to ligands that bind reversibly to receptors or enzymes requiring the simultaneous measurement of plasma and tissue radioactivities for multiple times after the injection of a radiolabeled tracer is presented. It is shown that there is a time t after which a …
Studies of Protein Metabolism in Man with Infusions of [14C]Tyrosine | Clinical Science | Portland Press
W. P. T. James, P. J. Garlick, P. M. Sender; Studies of Protein Metabolism in Man with Infusions of [14C]Tyrosine. Clin Sci Mol Med 1 January 1974; 46 (1): 8P. doi: https://doi.org/10.1042/cs046008Pa. Download citation file:. ...
Radioactive Dating Using Carbon-14 And Other Nuclides
becomes insignificantly small to be measurable.. Carbon-14 dating is based on carbon-14 decaying to nitrogen. Carbon-14 is continually replenished in the atmosphere when neutrons in cosmic rays bombard nitrogen-14. Living organisms generally take in carbon from the atmosphere in form of carbon dioxide, in most instances, green plants absorb carbon-dioxide and pass the radiocarbon to animals along the food chain.. Carbon-14 is continually added to living organisms as long as they take in air and food. Absorption of carbon-14 stops immediately the organism dies and the amount in their tissues start to decay. The rate of decay is constant, thus, the date the organism died can be determined by measuring the amount of residual radiocarbon carbon.. Other dating methods. Potassium-argon dating- used to determine ages of rocks by measuring the ratio of radioactive argon to radioactive potassium within it.it is based on decay of solid ...
Creation Worldview Ministries: Carbon-14 Dating Technique Does Not Work!
For some reason, which I have not yet figured out, at least one person per week has been asking me about the Carbon-14 Radiometric Dating Technique. They want to know if it is accurate or if it works at all. Worse still, sometimes they want to know how evolutionists use Carbon-14 to date dinosaur fossils!. The word radiometric as used in this article refers to the supposed use of the decay of radioactive chemical isotopes to supposedly measure the amount of time that has elapsed since an event occurred or a creature lived. Radiometric Dating Technologies are presented to the public by evolutionists as utterly reliable clocks for dating earth rocks or biological materials. There are more than 80 such technologies that are claimed to work. Carbon-14 is the best known of all these methods.. Prior to looking at the many flaws in the Carbon-14 Dating Technique, it should be noted that no radiometric technique is reliable. They all start with similar flaws, but Carbon-14 has more than the rest.. Many ...
Difference between revisions of Lidstrom:Measuring 13C Incorporation Into Protein - CO2 Project - OpenWetWare
Use the nitrogen tree: Turn heat on high. Set pressure regulator on tank to 2-4 psi. Flow gauge should read 8 L/min for two samples. Clean capillary tips with ethanol, unscrew white plastic, move metal shaft down (may need to wipe with ethanol to allow this), insert capillary tip into glass sample vial (close to liquid but not touching), screw plastic threading back to lock the metal shaft in place. Leave heating block on. Move sample vial up hourly as liquid evaporates ...
Lidstrom:Measuring 13C Incorporation Into Protein - CO2 Project - OpenWetWare
Use the nitrogen tree: Turn heat on high. Set pressure regulator on tank to 2-4 psi. Flow gauge should read 8 L/min for two samples. Clean capillary tips with ethanol, unscrew white plastic, move metal shaft down (may need to wipe with ethanol to allow this), insert capillary tip into glass sample vial (close to liquid but not touching), screw plastic threading back to lock the metal shaft in place. Leave heating block on. Move sample vial up hourly as liquid evaporates ...
993-994 carbon-14 spike - Wikipedia
The 993-994 carbon-14 spike was a rapid increase in carbon-14 content from tree rings, and followed the 774-775 carbon-14 spike. This event is also confirmed by a sharp increase of beryllium-10 and hence considered as solar-origin.  It may have come from a massive solar storm as a series of auroral observations are known to be observed in late 992. . ...
Carbon-14 dating is useful for estimating the age of
Carbon-14 dating is useful for estimating the age of - Find single woman in the US with relations. Looking for love in all the wrong places? Now, try the right place. Want to meet eligible single woman who share your zest for life? Indeed, for those whove tried and failed to find the right man offline, rapport can provide. How to get a good woman. It is not easy for women to find a good man, and to be honest it is not easy for a man to find a good woman.
The Big C...
Imagine my surprise when the lump on the left turned out to be nothing but they found something on the right. I was told to track down my old scans from a previous doc/clinic so they could do a comparison. Was this a new something? Or something that has always been there and just disregarded. Fine. It wasnt easy tracking down my baseline scans. The clinic had been sold and changed hands a couple times, but we got them ...
Improved preparation of l-[Methyl-<sup>11</sup>C]methionine by on-line [<sup>11<...
TY - JOUR. T1 - Improved preparation of l-[Methyl-11C]methionine by on-line [11C]methylation. AU - Mizuno, Ken Ichiro. AU - Yamazaki, Shigeki. AU - Iwata, Ren. AU - Pascali, Claudio. AU - Ido, Tatsuo. PY - 1993. Y1 - 1993. N2 - On-line [11C]methylation using [11C]methyl iodide has been successfully applied to the preparation of l-[methyl-11C]-methionine (11C-Met). [11C]Methyl iodide is first trapped in a short column that contains Porapak Q and l-homocysteine thiolactone coated on inert support. The column is then charged with NaOH dissolved in a mixture of ethanol and water to cause the [11C]methylation. The present method can provide practically pure 11C-Met in radiochemical yield of over 98%. The whole procedure including the sterilization of final product has been completely automated for routine PET use.. AB - On-line [11C]methylation using [11C]methyl iodide has been successfully applied to the preparation of l-[methyl-11C]-methionine (11C-Met). [11C]Methyl iodide is first trapped in a ...
Amino Acid and Protein Metabolism in Hospitalized Patients as Measured by l-[U-14C]Tyrosine and l-[1-14C]Leucine | Clinical...
1. Plasma amino acid kinetics were determined in hospitalized patients receiving one of three intravenous solutions: isotonic amino acids, isotonic sodium chloride, or total parenteral nutrition.. 2. Whole body amino acid appearance, oxidation and incorporation into protein were estimated with two different isotopically labelled amino acids: l-[1-14C]leucine and l-[U-14C]tyrosine.. 3. A positive correlation was obtained between whole body amino acid appearance, oxidation and incorporation into protein with the two isotopically labelled amino acids.. 4. Derivation of whole body protein kinetics with l-[U-14C]tyrosine consistently gave higher values than those obtained from l-[1-14C]leucine, presumably due in part to the contribution of phenylalanine hydroxylation to plasma tyrosine appearance. However, the percentages of amino acid appearance oxidized and used for protein synthesis were similar.. 5. It can be concluded that estimates of whole body protein kinetics are qualitatively similar when ...
Test-retest repeatability of myocardial oxidative metabolism and efficiency using standalone dynamic 11C-acetate PET and...
Read Test-retest repeatability of myocardial oxidative metabolism and efficiency using standalone dynamic 11C-acetate PET and multimodality approaches in healthy controls, Journal of Nuclear Cardiology on DeepDyve, the largest online rental service for scholarly research with thousands of academic publications available at your fingertips.
Positron Emission Tomography (PET) Study With [11C]AZD2995 and [11C]AZD2184, Candidate PET Ligands for β Amyloid - Full Text...
The study is carried out in order to investigate if [11C]AZD2995, compared to [11C]AZD2184, is a more suitable PET ligand for in vivo imaging of β amyloid depositions in the human brain. In the study the two PET ligands will be examined in both healthy volunteers and patients with Alzheimers Disease ...
Hyperpolarized carbon-13 MRI - Wikipedia
Hyperpolarized carbon-13 MRI is a functional medical imaging technique for probing perfusion and metabolism using injected substrates. It is enabled by techniques for hyperpolarization of carbon-13-containing molecules using dynamic nuclear polarization and rapid dissolution to create an injectable solution. Following the injection of a hyperpolarized substrate, metabolic activity can be mapped based on enzymatic conversion of the injected molecule. In contrast with other metabolic imaging methods such as positron emission tomography, hyperpolarized carbon-13 MRI provides chemical as well as spatial information, allowing this technique to be used to probe the activity of specific metabolic pathways. This has led to new ways of imaging disease. For example, metabolic conversion of hyperpolarized pyruvate into lactate is increasingly being used to image cancerous tissues via the Warburg effect. While hyperpolarization of inorganic small molecules (like 3He and 129Xe) is generally achieved using ...
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Lecture Notes 103009b - Dating by Radioactivity Carbon Dating takes advantage of the decay of carbon-14 which has a half-life...
View Notes - Lecture_Notes_103009b from CHEM 105BLG at USC. Dating by Radioactivity Carbon Dating takes advantage of the decay of carbon-14 which has a half-life of 5730 years What percentage of C-14
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I was also a bit confused with what you meant by baseline scan. From what I understand of the IVF treatment I had, after downregging they do a scan to check your uterus lining is thin, to show your system is effectively shutdown.They can then take control of your cycle by starting the stimulating injections. Its at this point after a few days you should be producing follicles. My first scan after starting stimulating injections showed no response at all. (Cant remember exactly how many days after starting stimming, but at least 4 or 5 days I think). They then more than doubled my dose of stimming drugs (I was on Gonal F). I did start to respond, but slowly at first and there were only 8 follicles a week before EC. 3 days before EC I had responded more and had a few more follicles, but they didnt know if some would be big enough. They collected 12 eggs on EC day. I dont know if this helps, but from my experience things can change by EC day ...
How many years will it take for carbon-14 to diminish to 1, Ask an Expert
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维生素C - 维基百科，自由的百科全书
维生素C治疗坏血病是250年来医学证实的事实。坏血病是长期缺乏维生素C的最终病况，它在人体上的表现是极度疲乏、肌肉无力、皮肤肿胀疼痛、牙龈出血、口臭、皮下及肌肉中血管破裂出血、关节软弱、骨骼脆弱以致骨折、虚脱、泻痢、肺脏及肾脏衰竭而导致昏迷以致死亡。由此可见维生素C对各个主要器官都有影响。 腎上腺是人體含維生素C最高的器官。人體在緊張的時候，腎上腺分泌大量的腎上腺素到全身的肌肉中，準備好隨時動作，應付危機。腎上腺素是從酪氨酸（Tyrosine）制成多巴（Dopa），轉化成多巴胺（Dopamine），再轉化為降腎上腺素（Noradrenaline），最后制成腎上腺素。其中每一步驟都要消耗維生素C進行羥基化反應（Hydroxylation）。這是人和動物的腎上腺必須儲備大量維生素C的原因。 ...
A Phase 1 Study to Assess Mass Balance, Pharmacokinetics, and Metabolism of [14C]-Pevonedistat in Patients With Advanced Solid...
The purpose of this study is to assess the mass balance (that is, cumulative excretion of total radioactivity [TRA] in urine and feces) of pevonedistat
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QUANTULUS GCT 110 V LSC | PerkinElmer
The Quantulus GCT 6220 is a liquid scintillation counter (LSC) for ultra low-level sensitivity, in a lighter benchtop footprint to fit any lab.
Shhhh! Sleeping Ovaries! | a.k.a.mrs.x
I went in for my baseline scan today as Big Red showed up right on time on Tuesday. Normally the baseline scan I have done is for an IUI to see if the roiding from the last cycle had sufficiently quieted down. This time it was to see if my ovaries were in nice Lupron-induced…
What is Radioactivity? Read This to Find Out
Radioactivity is a process of emission of radiation and energy from unstable nuclei in order to form more stable atoms. What is radioactivity? What are its applications? Read on to find out.
Radioactivity | Bartleby
Free Essays from Bartleby | Radioactivity has been around since the 1800s. It is very popular in the medical field. It is used my many professionals to help...
68Ga-PSMA and 11C-Choline comparison using a tri-modality PET/CT-MRI (3.0 T) system with a dedicated shuttle | European Journal...
The aim of this study was to prospectively compare the detection rate of 68Ga-PSMA versus 11C-Choline in men with prostate cancer with biochemical recurrence and to demonstrate the added value of a tri-modality PET/CT-MRI system. We analysed 36 patients who underwent both 11C-Choline PET/CT and 68Ga-PSMA PET/CT scanning within a time window of 1-2 weeks. Additionally, for the 68Ga-PSMA scan, we used a PET/CT-MRI (3.0 T) system with a dedicated shuttle, acquiring MRI images of the pelvis. Both scans were positive in 18 patients (50%) and negative in 8 patients (22%). Nine patients were positive with 68Ga-PSMA alone (25%) and one with 11C-Choline only (3%). The median detected lesion per patient was 2 for 68Ga-PSMA (range 0-93) and 1 for 11C-Choline (range 0-57). Tumour to background ratios in all concordant lesions (n = 96) were higher for 68Ga-PSMA than for 11C-Choline (110.3 ± 107.8 and 27.5 ± 17.1, mean ± S.D., for each tracer, respectively P = 0.0001). The number of detected lesions per patient
Radiometric Detection | PerkinElmer
For over 65 years, PerkinElmer has been a leading provider and partner for radiometric detection solutions ranging from instruments and radiochemicals, to liquid scintillation cocktails, vials, and microplates.
Correcting for diffusion in carbon-14 dating of ground water
It has generally been recognized that molecular diffusion can be a significant process affecting the transport of carbon-14 in the subsurface when occurring either from a permeable aquifer into a confining layer or from a fracture into a rock matrix. An analytical solution that is valid for steady-state radionuclide transport through fractured rock is shown to be applicable to many multilayered aquifer systems. By plotting the ratio of the rate of diffusion to the rate of decay of carbon-14 over the length scales representative of several common hydrogeologic settings, it is demonstrated that diffusion of carbon-14 should often be not only a significant process, but a dominant one relative to decay. An age-correction formula is developed and applied to the Bangkok Basin of Thailand, where a mean carbon-14-based age of 21,000 years was adjusted to 11,000 years to account for diffusion. This formula and its graphical representation should prove useful...
AID 629721 - Displacement of [3H]-8-OH-DPAT from 5-HT1A receptor in rat hippocampus by liquid scintillation counting - PubChem
BioAssay record AID 629721 submitted by ChEMBL: Displacement of [3H]-8-OH-DPAT from 5-HT1A receptor in rat hippocampus by liquid scintillation counting.
PRESCRIBING INFORMATIONTABLOID®brand Thioguanine40-mg Scored Tablets - Drug label and information - Rx Drugs Info
Clinical studies have shown that the absorption of an oral dose of thioguanine in humans is incomplete and variable, averaging approximately 30% of the administered dose (range: 14% to 46%). Following oral administration of 35S-6-thioguanine, total plasma radioactivity reached a maximum at 8 hours and declined slowly thereafter. Parent drug represented only a very small fraction of the total plasma radioactivity at any time, being virtually undetectable throughout the period of measurements.. The oral administration of radiolabeled thioguanine revealed only trace quantities of parent drug in the urine. However, a methylated metabolite, 2-amino-6-methylthiopurine (MTG), appeared very early, rose to a maximum 6 to 8 hours after drug administration, and was still being excreted after 12 to 22 hours. Radiolabeled sulfate appeared somewhat later than MTG but was the principal metabolite after 8 hours. Thiouric acid and some unidentified products were found in the urine in small amounts. Intravenous ...
Prospective study of 11C-methionine PET for distinguishing between recurrent brain metastases and radiation necrosis:...
Several previous retrospective studies of MET-PET for BM focused on its diagnostic accuracy and provided an optimal cut-off value for diagnosis but, unfortunately, did not provide subsequent management details. Such specific details are often of critical importance to physicians caring for BM patients. The authors sought to provide information useful for physicians on how to manage such refractory situations, by investigating not only the diagnostic accuracy of MET-PET but also the long-term results of salvage management. We believe this novel viewpoint to be the core value of the present work.. This is the first report to demonstrate that MET-PET can predict the patients survival as well as providing the immediate diagnosis. This exploratory insight has, in our opinion, clinical significance and can be regarded as relevant because RN follows a self-limited course in most cases while, in contrast, LR can lead to neurological death. In fact, we observed that 9 patients diagnosed with LR on ...
Heterogeneity of ventricular function and myocardial oxidative metabolism in nonischemic dilated cardiomyopathy | JACC: Journal...
Background. Heterogeneity in regional left ventricular function has long been noted in patients with nonischemic dilated cardiomyopathy. Regional variation in wall stress has been proposed as the pathophysiologic mechanism. By correlating regional function with oxidative metabolism, one can test the hypothesis that heterogeneity in wall stress is responsible for heterogeneity in function. We hypothesized that preserved function as a result of more favorable loading conditions would be associated with regional oxidative metabolism that is equal to or lower than that in other regions. ...
Apologetics Press - Evolution and Carbon-14 Dating
Both evolutionists and creationists stand in agreement that radiocarbon dating, which can be used only to date organic samples, is totally ineffective in measuring the alleged millions or billions of years of the evolutionary timetable. [In truth, even when dating things that are relatively young, carbon-14 dating is imperfect and based upon certain unprovable assumptions (see Major, 1993).] If radiocarbon dating can measure only items that are thousands of years old, why should evolutionists even consider using this dating method on anything that they already believe to be millions of years old? Creationists would like to see evolutionists apply this method to items believed to be millions of years old, because it might help convince evolutionists that coal, diamonds, fossils, etc. are not millions of years old, but only thousands of years old.. Consider that in recent years readily detectable amounts of carbon-14 in materials evolutionists suppose are millions of years old have been the ...
C CO 27 BSB (WDJ6C0) - WikiLeaks
BEGIN PGP PUBLIC KEY BLOCK----- mQQNBFUoCGgBIADFLp+QonWyK8L6SPsNrnhwgfCxCk6OUHRIHReAsgAUXegpfg0b rsoHbeI5W9s5to/MUGwULHj59M6AvT+DS5rmrThgrND8Dt0dO+XW88bmTXHsFg9K jgf1wUpTLq73iWnSBo1m1Z14BmvkROG6M7+vQneCXBFOyFZxWdUSQ15vdzjr4yPR oMZjxCIFxe+QL+pNpkXd/St2b6UxiKB9HT9CXaezXrjbRgIzCeV6a5TFfcnhncpO ve59rGK3/az7cmjd6cOFo1Iw0J63TGBxDmDTZ0H3ecQvwDnzQSbgepiqbx4VoNmH OxpInVNv3AAluIJqN7RbPeWrkohh3EQ1j+lnYGMhBktX0gAyyYSrkAEKmaP6Kk4j /ZNkniw5iqMBY+v/yKW4LCmtLfe32kYs5OdreUpSv5zWvgL9sZ+4962YNKtnaBK3 1hztlJ+xwhqalOCeUYgc0Clbkw+sgqFVnmw5lP4/fQNGxqCO7Tdy6pswmBZlOkmH XXfti6hasVCjT1MhemI7KwOmz/KzZqRlzgg5ibCzftt2GBcV3a1+i357YB5/3wXE j0vkd+SzFioqdq5Ppr+//IK3WX0jzWS3N5Lxw31q8fqfWZyKJPFbAvHlJ5ez7wKA 1iS9krDfnysv0BUHf8elizydmsrPWN944Flw1tOFjW46j4uAxSbRBp284wiFmV8N TeQjBI8Ku8NtRDleriV3djATCg2SSNsDhNxSlOnPTM5U1bmh+Ehk8eHE3hgn9lRp 2kkpwafD9pXaqNWJMpD4Amk60L3N+yUrbFWERwncrk3DpGmdzge/tl/UBldPoOeK p3shjXMdpSIqlwlB47Xdml3Cd8HkUz8r05xqJ4DutzT00ouP49W4jqjWU9bTuM48 LRhrOpjvp5uPu0aIyt4BZgpce5QGLwXONTRX+bsTyEFEN3EO6XLeLFJb2jhddj7O ...
IDVG Definition: Initial Distribution Volume of Glucose
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cobalt-60 has a half-life of 5.26 years, how much of a 500 gram sample
You have 5 grams of carbon-14; whose half-life is 5730 years. a)Write the rule of the function that gives the amount of carbon-14 remaining after x years. b)How much carbon-14 will be left after 4,000 years ...
FlashPlate HTS, Basic Microplate, 384-well, 20 Plates | PerkinElmer
FlashPlate® is a white polystyrene microplate, designed for high-volume, homogeneous radiometric assays, based upon the principle of scintillation proximity. The interior of each well is permanently coated with a thin layer of polystyrene-based scintillant which provides a platform for non-separation assays using a variety of isotopes (e.g.,3H, 125I, 14C and 33P) without the addition of liquid scintillation cocktail. FlashPlate is available in both 96-well and 384-well formats.. ...
Description: Tumor doubling time was estimated using an exponential growth model. Specifically, the pre-progression scan, and the baseline scan were used to estimate the doubling time prior to enrollment, td = log(2)∗1time/1log(tumor size) [derivation, S(t) = S(to)∗2∧[(t−to)/td] for a parameterization of exponential growth with a doubling time of td. Taking the logarithm on both sides: log(S(t))-log(S(to)) = log(2)∗(t − to)/td or td = log(2)∗(t − to)/[log(S(t))-log(S(to))] = log(2)∗1time/1log(S)], the baseline scan and first evaluation scan were used to determine the doubling time. Based on pre-planned protocol assessment, we estimated the percent of patients that experienced a slowing of tumor kinetics (a 30% increase in the length of time for tumor doubling) based on RECIST v1.1 measurements. Patients who did not get a scan on study, and patients whose pre-progression scans were missing or whose pre-progression tumor size was zero or whose tumor was decreasing prior to ...
PICO-FLUOR PLUS / 2*5 L | PerkinElmer
Pico-Fluor Plus is a NPE free Liquid Scintillation Cocktail featuring high sample load capacity for aqueous samples and buffer solutions, dompatibility with alkaline tissue solubilizers, compatibility and no background with alkaline sample material, and relatively high Counting efficiency for tritium. ...
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Handling Live Cultured Cells Keep a flask with 20 ml existing medium in 37°C CO2 incubator for 1 hour before replacing the medium. Either split the 90% confluent cells from a T25 flask to a T75 flask after 1 hour or let the cells grow in the T25 flask for 12-24 hours before split the cells to a T75 flask. Cells should be checked daily under a microscopy to verify appropriate cell morphology. ...
Leicester Research Archive: The trace detection of DNA adducts by accelerator mass spectrometry and 14C-postlabelling
Accelerator mass spectrometry (AMS) is currently the most sensitive method for trace DNA adduct detection. O6-Mehtyldeoxyguanosine (O 6-MedG) is a strongly mutagenic lesion formed by a variety of alkylating agents. For this reason this was the adduct of choice for use in this study, the aim of which was to develop a 14C-postlabelling technique, involving incorporation of radiolabel onto O6-MedG adducts after isolation, thus enabling exploitation of AMS to detect low levels of adducts without the need to administer a 14C-labelled compound. A method was developed and optimised for acetylating O6-MedG, in , 90% yields. This method was then used to acetylate the adduct with 14C-acetic anhydride, but changes required for the safe handling of radiolabelled compound altered the reaction product profile, resulting in the major derivative being 14C-di-acetyl O6-MedG, (38% yield). This pure standard was used to determine detection limits of 1.4 pmoles of adduct using HPLC and liquid scintillation counting ...
Accelerator mass spectrometry (AMS) of the inhibitory effect of six dietary constituents on nicotine-hemoglobin adduction in...
Accelerator mass spectrometry (AMS) is an ultra-sensitive method to monitor and trace the environmental exposure levels of 14C-labeled molecules in vivo. Nicotine [3-(1-methyl-2-pyrrolidinyl)-pyridine], a major alkaloid in tobacco products, has proven to be a potential genotoxic compound. Using 14C-labeled nicotine and AMS, we have investigated the inhibitory effect of curcumin, garlic squeeze, grapeseed extract, tea polyphenols, vitamin C and vitamin E, respectively, on nicotine-hemoglobin (Hb) adduction in vivo. The results demonstrated that these dietary constituents induced remarkable decrease of nicotine-Hb adducts. The inhibitory fact may afford an important clue of the chemoprevention of the potential nicotine-induced carcinogenesis. ...
5-HTT binding in recovered depressed patients and healthy volunteers: a positron emission tomography study with [11C]DASB. -...
OBJECTIVE: The serotonin transporter (5-HTT) is a key target for selective serotonin reuptake inhibitors and may be involved in the pathophysiology of major depression. It is now possible to image 5-HTT directly in the human brain, but results from studies of acutely depressed patients have been inconsistent. The purpose of this study was to determine whether abnormalities in 5-HTT might be present in recovered depressed patients. METHOD: The authors measured the binding potential of 5-HTT using [11C]DASB in conjunction with positron emission tomography (PET) in 24 medication-free, recovered depressed male patients and 20 healthy male comparison subjects. The regional estimates of binding potential were obtained using a metabolite-corrected plasma input function method followed by Logan analysis, with the cerebellum as a reference region. RESULTS: The authors found no significant difference in the binding potential of [11C]DASB between the recovered depressed patients and healthy comparison subjects in
Optimization of [ 11 C]methionine PET study: appropriate scan timing and effect of plasma amino acid concentrations on the SUV ...
[11C]methionine (MET) has been used to monitor amino acid metabolism in tumors, the pancreas, liver, and myocardium. The aim of the present study was to standardize [11C]MET positron emission tomography (PET) by optimizing the timing of initiation of the scan and applying correction to the plasma concentrations of neutral amino acids (NAAs), where necessary. Sequential whole-body MET PET/computed tomography (CT) was performed in 11 normal adults after they had fasted for at least 4 h. After whole-body CT for attenuation correction and intravenous bolus injection of MET, the subjects were scanned from the parietal to the groin. The scanning was repeated six to seven times. Decay of radioactivity during the PET scan was corrected to the time of initiation of the first scan. The standardized uptake values (SUVs) were evaluated in various organs by setting regions of interest on the tomographic images. Plasma concentrations of NAAs were examined in relation to the SUV values. The SUVs in the pancreas
TRI-CARB 5110TR 110 V Liquid Scintillation Counter - Emphor Life Analytical Science
The Tri-Carb 4910TR liquid scintillation counter provides the popular standard features needed for research applications and the versatility to expand for environmental analysis with the optional ultralow-level and alpha/beta discrimination features.. The Tri-Carb 4910TR liquid scintillation counter provides high performance and flexibility for multi-application and multi-user laboratories detecting radioactivity in life science research, environmental monitoring and/or health physics assays. Optional Packages are available for High Sensitivity Counting of low activity samples and Alpha Beta Separation for unknown or mixed samples.. Exclusive Standard Features. ...
Biosynthetis of phytoquinones. Biosynthetic origins of the nuclei and satellite methyl groups of plastoquinone, tocopherols and...
1. By using dl-[ring−14C]phenylalanine, dl-[β−14C]phenylalanine, dl-[α−14C]-tyrosine and dl-[β−14C]tyrosine it was shown that in maize shoots (Zea mays) the nucleus and one nuclear methyl group of each of the following compounds, plastoquinone, γ-tocopherol (aromatic nucleus) and α-tocopherolquinone, are formed from the nuclear carbon atoms and β-carbon atom respectively of either exogenous phenylalanine or exogenous tyrosine. With ubiquinone only the aromatic ring of the amino acid is used in the synthesis of the quinone nucleus. Chemical degradation of plastoquinone and γ-tocopherol molecules labelled from l-[U−14C]tyrosine established that a C6-C1 unit directly derived from the amino acid is involved in the synthesis of these compounds. Radioactivity from [β−14C]cinnamic acid is not incorporated into plastoquinone, tocopherols or tocopherolquinones, demonstrating that the C6-C1 unit is not formed from any of the C6-C1 phenolic acids associated with the metabolism of this ...
Why are rising CO2 levels caused by burning fossil fuels? › Ask an Expert (ABC Science)
Carbon is released into the atmosphere from a variety of sources including respiration of plants and microbes, bushfires, volcanoes, and burning fossil fuels. Some of these mechanisms have a distinct carbon isotopic signature.. There are three types of carbon isotopes - molecules of carbon with different atomic weights: carbon-12 (12C), carbon-13 (13C) and carbon-14 (14C). Carbon-12 is the most common form found in nature. Carbon-13 is about 1 per cent of the total. Carbon-14, which is produced in the upper atmosphere, accounts for an even much smaller amount. Plants take up all forms of carbon in the process of photosynthesis, but they prefer the lighter carbon-12, leaving carbon-13 behind in the atmosphere.. That enriches carbon-13 in the atmosphere compared to carbon-13 in the biosphere, which is why carbon-13 is more abundant in the atmosphere, says Fraser. But measurements of the composition of CO2 show a decline in the ratio of carbon-13 to carbon-12 in the atmosphere of about 3 per cent ...
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System for closed arterial blood sampling and pressure monitoring Conventional three-way stopcocks for arterial blood sampling are basically an open gate for microorganisms to enter.
PET: About the PET Center | Department of Radiology
The PET Facility at the University of Pittsburgh has been operational since 1992, and is administered as a research division of the Department of Radiology under the direction of Chester A Mathis, Ph.D. The PET Facility is housed in over 12,000 square feet of the 9th floor of the B-wing in Presbyterian-University Hospital, University of Pittsburgh Medical Center (UPMC) Health System. This space includes three scanner bays serviced by two control rooms, inpatient and outpatient preparation rooms, and a small wet laboratory outfitted with an array of radiation detection instrumentation for blood and radiolabeled metabolite assays. The PET Radiochemistry Laboratory is included within the PET Facility and is divided into a cold chemistry laboratory of 1000 sq. ft., a hot radiochemistry laboratory of 1000 sq. ft., and a 1200 sq. ft. cyclotron vault that houses a Siemens Eclipse HP medical cyclotron and ancillary supporting electronics and equipment. Research investigators, students, and PET Facility ...
Evaluation of brain tumors using dynamic 11C-methionine-PET
The aim of this study is to assess whether dynamic imaging of (11)C-methionine (MET) uptake on positron emission tomography (PET) is useful for the differential diagnosis of brain tumor histology. Regional MET uptake in static brain PET scans from three consecutive phases (5-15, 15-25, and 25-35 min …
Recent epidemiological research and pet experiments have proven that non-steroidal anti-inflammatory - Genomics Proteomics and...
Recent epidemiological research and pet experiments have proven that non-steroidal anti-inflammatory drugs (NSAIDs) decrease the incidence of colorectal carcinoma. the steroid receptor superfamily. PPAR- is important in both adipocyte differentiation and carcinogenesis. PPAR- is definitely one focus on for cell development modulation of NSAIDs. With this review, we record the manifestation of COX-2, LOX and PPAR- in human being prostate cancer cells aswell as the consequences of COX-2 and LOX inhibitors and PPAR- ligand. solid course=kwd-title Keywords: cyclooxygenase, lipoxygenase, peroxisome proliferator activator-receptor-, prostate tumor Introduction Prostate tumor (Personal computer) includes 32% of most malignancies in American males and is within the boost worldwide. Due to increased screening, Personal computer is generally diagnosed at a medically localized stage, rendering it amenable to the treatment. Nevertheless, it continues to be the next most common reason behind cancer loss of ...
Measurement of Radioactivity. Total radioactivity in liquid samples [plasma, urine and bile (BDC rats only)] from all species was determined by liquid scintillation counting using a Tri-Carb 2500A liquid scintillation spectrometer (Canberra Packard, Groningen, The Netherlands). Samples were made up to 1 ml with distilled water, if necessary, and prepared for radioanalysis by the addition of Ultima Gold scintillation cocktail. Solid samples (feces) were homogenized, lyophilized, homogenized again, and combusted using the Canberra Packard System 387 (Oxidizer Tri-Carb 307 and Robot System 80). The formed 14CO2 was trapped in Carbo-Sorb and topped up with scintillation cocktail (Permafluor E+) before radioanalysis.. Metabolite Profiling. Metabolite patterns in plasma, urine, and feces from all species and in bile from BDC rats were determined using high-performance liquid chromatography (HPLC) with on-line radioactivity detection (Ramona 5; Raytest GmbH, Straubenhardt, Germany) or off-line ...
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ACETYL TRIBUTYL CITRATE (ATBC) Primary Plasticizer for PVC and PVC copolymers Chemical Nature Chemical Name :- 2-acetyl-1,2,3-Propane tri carboxylic acid Tributyl Ester Trade Name :- ATBC Molecular Formula :- C 20 H 34 O 8 Molecular Weight :- 402.5 H 2 C - CO 2 C 4 H 9 C 2 H 5 CO 2 - C - CO 2 C 4 H 9 H 2 C - CO 2 C 4 H 9 CAS Number :- 77-90-7 UN ...
C14 dating reliability - How reliable is carbon dating? Is radiocarbon dating a good method.
Radiocarbon dating involves determining the age of an ancient fossil or specimen by measuring its carbon-14 content. Willard Libby invented the carbon dating technique in the early 1950s. Carbon dating, also known as radiocarbon dating, is a scientific.
CARNITINE HCL, L-[METHYL-3H]- | PerkinElmer
Acetyl-L-carnitine HCL is a mitochondrial metabolite that facilitates the movement of fatty acids into the mitochondria for energy and is also used to generate acetyl coenzyme A. ...
Laboratorio de Analisis de Residuod de Plaguicidas LARP - Caribbean Environment Programme
Chromatography of gaese with U-ECD, NPD and FPD Chromatography of gases coupled with mass spectrometry, Liquid chromatography with Post Column derivation and fluoroescence detector, Liquid chromatography with an arrangement of diodes ,Liquid scintillation ...
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Formula: C23H22O7 MW: 410. 42 TNP NUMBER: TNP00188 MDL NUMBER: MFCD02184614 IUPAC: 2-(2-hydroxy-1-methyleneethyl)-8,9-dimethoxy-1,2-dihydrochromano[3,4-b]furano[ 2,3-h]chroman-6-one Smiles: c1(cc2c(cc1OC)OCC1C2C(c2c(O1)c1c(cc2)OC(C1)C(CO)=C)=O)OC ACCEPTORS: 7 DONORS: 1 ROTATION BONDS: 5 N+O: 7 Chiral Centers: 3 LogP: 3....
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Radioactivity: A Very Short Introduction - Claudio Tuniz - Oxford University Press
You cannot hide from radioactivity. Even the book you are holding is slightly radioactive, but there are more serious risks. Radioactivity - the breakdown of unstable atomic nuclei, releasing radiation - is a fundamental process in nature. It is a process that has been harnessed to provide wide and important applications in science, medicine, industry, and energy production.
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Although carbon-14 was previously known, the discovery of the synthesis of carbon-14 occurred at Berkeley in 1940 when Kamen ... Creager, Angela N. H. (October 2, 2013). Life Atomic: A History of Radioisotopes in Science and Medicine. University of Chicago ... By bombarding matter with particles in the cyclotron, radioactive isotopes such as carbon-14 were generated. Using carbon-14, ... "Carbon-14 discoverer who was harassed as communist". The Irish Times. September 21, 2002. Retrieved August 15, 2022. Report of ...
Some of these radioisotopes are tritium, carbon-14 and phosphorus-32. Here is a list of radioisotopes formed by the action of ... of nitrogen-14 forms carbon-14. This radioisotope can be released from the nuclear fuel cycle; this is the radioisotope ... In addition some natural radioisotopes are present. A recent paper reports the levels of long-lived radioisotopes in the ... Just because a radioisotope lands on the surface of the soil, does not mean it will enter the human food chain. After release ...
For example, one might culture plants in an environment in which the carbon dioxide contained radioactive carbon; then the ... Radioisotopes are also a method of treatment in hemopoietic forms of tumors; the success for treatment of solid tumors has been ... In nuclear medicine, radioisotopes are used for diagnosis, treatment, and research. Radioactive chemical tracers emitting gamma ... "Radioisotopes in Industry". World Nuclear Association. Martin, James (2006). Physics for Radiation Protection: A Handbook. p. ...
Tin also has four radioisotopes that occur as the result of the radioactive decay of uranium. These isotopes are tin-121, tin- ... Carbon also forms many oxides such as carbon monoxide, carbon suboxide, and carbon dioxide. Carbon forms disulfides and ... Carbon is present in the atmosphere in the form of carbon monoxide, carbon dioxide, and methane. Carbon is a key constituent of ... Carbon is most commonly used in its amorphous form. In this form, carbon is used for steelmaking, as carbon black, as a filling ...
Prices of chemical elements
Carbon in the form of diamond can be more expensive than rhodium. Per-kilogram prices of some synthetic radioisotopes range to ... Chlorine, sulfur and carbon (as coal) are cheapest by mass. Hydrogen, nitrogen, oxygen and chlorine are cheapest by volume at ... The price listing for radioisotopes is not exhaustive. 2000s commodities boom Density for 0 °C, 101.325 kPa. For individual ...
Paul Hugh Emmett
He used radioisotopes like Carbon-14 to study the mechanism of catalytic reactions. In the 1950s, Emmett's research ...
In 2017, Norilsk produced 1.798 million tons of carbon pollutants-nearly six times more than the 304,600 tons that was ... The list cites air pollution by particulates, including radioisotopes strontium-90, and caesium-137; the metals nickel, copper ... cobalt, and lead; selenium; and by gases (such as nitrogen and carbon oxides, sulfur dioxide, phenols and hydrogen sulfide). ...
Brain positron emission tomography
The radioisotopes used in clinics are normally 18F (fluoride), 11C (carbon) and 15O (oxygen). The labeled compound, called a ... 57 The positron emitting radioisotopes used are usually produced by a cyclotron, and chemicals are labeled with these ...
... s have also been measured in humans using the non-radioactive, carbon monoxide (CO) rebreathing technique for more ... Park, Junki; Puri, Sonika; Mattoo, Aditya; Modersitzki, Frank; Goldfarb, David (2012). "Radioisotope Blood Volume Measurement ... The assessment of total hemoglobin mass by carbon monoxide rebreathing". Journal of Applied Physiology. 123 (3): 645-654. doi: ...
Cosmic ray spallation
Some of the well-known naturally-occurring radioisotopes are tritium, carbon-14, and phosphorus-32. The timing of their ... In addition to the above light elements, tritium and isotopes of aluminium, carbon (carbon-14), phosphorus (phosphorus-32), ... Starrfield, Sumner (27 May 2020). "Carbon-Oxygen Classical Novae Are Galactic 7Li Producers as well as Potential Supernova Ia ...
... use of radioisotope tracers are sometimes called radioisotope feeding experiments. Radioisotopes of hydrogen, carbon, ... 99mTc is a very versatile radioisotope, and is the most commonly used radioisotope tracer in medicine. It is easy to produce in ... The commonly used radioisotopes have short half lives and so do not occur in nature in large amounts. They are produced by ... Instead it is made by neutron irradiation of the isotope 13C which occurs naturally in carbon at about the 1.1% level. 14C has ...
High levels of carbon dioxide (CO 2) may indicate a fire, and can be detected by a carbon dioxide sensor. Such sensors are ... An ionization smoke detector uses a radioisotope, typically americium-241, to ionize air; a difference due to smoke is detected ... Carbon monoxide sensors detect potentially fatal concentrations of carbon monoxide, which may build up due to faulty ... Fire without smoke can be detected by sensing carbon dioxide. Incomplete burning can be detected by sensing carbon monoxide. A ...
While cyclotron produced radioisotopes are widely used for diagnostic purposes, therapeutic uses are still largely in ... Positron and gamma emitting isotopes, such as fluorine-18, carbon-11, and technetium-99m are used for PET and SPECT imaging. ...
Labeled with the radioisotope carbon-11, it can be used for positron emission tomography. Bengt Andree; et al. (August 1998). " ...
Labeled with the radioisotope carbon-11, it can be used for positron emission tomography. Zheng LT, Hwang J, Ock J, Lee MG, Lee ...
Bioremediation of radioactive waste
Radioisotopes can be transformed directly through changes in valence state by acting as acceptors or by acting as cofactors to ... In these particular cases, a carbon source such as ethanol is added to the medium to promote the reduction of nitrate at first ... The radioisotope interact with binding sites of metabolically active cells and is used as terminal electron acceptor in the ... Several radioisotopes of strontium, for example, are recognized as analogs of calcium and incorporated within Micrococcus ...
Additionally, carbon-11 can also be made using a cyclotron; boron in the form of boric oxide is reacted with protons in a (p,n ... 3H (tritium), the radioisotope of hydrogen, is available at very high specific activities, and compounds with this isotope in ... 14C, carbon-14 can be made (as above), and it is possible to convert the target material into simple inorganic and organic ... 11C, carbon-11 is usually produced by cyclotron bombardment of 14N with protons. The resulting nuclear reaction is 14N(p,α)11C ...
Cosmic rays may also produce radioisotopes on Earth (for example, carbon-14), which in turn decay and emit ionizing radiation. ... Measurements of carbon-14, can be used to date the remains of long-dead organisms (such as wood that is thousands of years old ... As humans, plants, and animals consume food, air, and water, an inventory of radioisotopes builds up within the organism (see ... "Gas Filled Detectors" (PDF). Lecture notes for MED PHYS 4R06/6R03 - Radiation & Radioisotope Methodology. MacMaster University ...
Wallace Smith Broecker
Carbon dioxide removal#Artificial trees List of geophysicists Julie Ann Wrigley Global Institute of Sustainability - Arizona ... including oceanic mixing based on stable and radioisotope distribution. This included research on the biogeochemical cycles of ... However, his contributions stretch far beyond the "conveyor"; his work is the foundation of carbon cycle science, and his ... linking the circulation of the global ocean and made major contributions to the science of the carbon cycle and the use of ...
Radioisotopes with half-lives shorter than one million years are also produced: for example, carbon-14 by cosmic ray production ... Short-lived radioisotopes that are found in nature are continuously generated or replenished by natural processes, such as ... Uranium-236 is produced in uranium ores by neutrons from other radioisotopes. Iodine-129 is produced from tellurium-130 by ...
Angela N. H. Creager
The X-10 reactor at Oak Ridge was used to produce radioisotopes such as cobalt-60, phosphorus-32, sulfur-35, and carbon-14. As ... A History of Radioisotopes in Science and Medicine (University of Chicago Press, 2013) on the use of radioisotopes in science ... Natural radioisotopes were used as tracers to track atoms and illuminate biological processes in living creatures and ... Bud, Robert (August 2015). "Angela N. H. Creager, Life Atomic: A History of Radioisotopes in Science and Medicine". Social ...
The most common radioisotopes for medical imaging agents, carbon-11 and fluorine-18, have a half-lives of 20.4 and 109.8 ... He has contributed major advances on the entire spectrum of research from fundamental chemistry methodology with radioisotopes ... Hooker and Stephen Buchwald (MIT) developed a strategy for labeling molecules with carbon-11 using cyanide nearly ... valproic acid and 4-phenylbutyric acid measured with carbon-11 labeled analogs by PET". Nuclear Medicine and Biology. 40 (7): ...
"Radiation Safety Manual for Laboratory Users, Appendix B: The Characteristics of Common Radioisotopes" Archived 2013-10-02 at ... Carbon-12 and carbon-13 are both stable, while carbon-14 is unstable and has a half-life of 5,730 ± 40 years. Carbon-14 decays ... carbon-12 (12 C), which makes up 99% of all carbon on Earth; carbon-13 (13 C), which makes up 1%; and carbon-14 (14 C), which ... A gram of carbon containing 1 atom of carbon-14 per 1012 atoms will emit ~0.2 beta particles per second. The primary natural ...
X-10 Graphite Reactor
Subsequent shipments of radioisotopes, primarily iodine-131, phosphorus-32, carbon-14, and molybdenum-99/technetium-99m, were ... A radioisotope building, a steam plant, and other structures were added in April 1946 to support the laboratory's peacetime ... They would be the last major air-cooled plutonium-producing reactors; the UK's follow-on Magnox and AGR designs used carbon ... "Peacetime use of radioisotopes at Oak Ridge cited as Chemical Landmark". American Chemical Society. February 25, 2008. ...
Some radioisotopes occur in nature with a half-life of less than 7×107 years (carbon-14: 5,730 ± 40 years, tritium: 12.32 years ... A practical use is radiocarbon dating with carbon-14. Stable isotope Environmental isotopes "Natural Isotopes". www.soest. ...
Harold G. Richter
There he conducted radioisotope research and developed radio-release methods for tracing contaminants in stream flows. Richter ... Dodge, Marcia C.; Richter, Harold G. (1991). "Chapter 3. Properties and principles of formation of carbon monoxide". U.S. EPA. ... Dodge, Marcia C.; Richter, Harold G. (1991). "CHAPTER 3. PROPERTIES AND PRINCIPLES OF FORMATION OF CARBON MONOXIDE". U.S. EPA. ... Hansen, Richard Lee; Schuster, Jack C. (1966). Discharge Measurement Using Radioisotopes in High Head Turbines and Pumps. U.S. ...
Carbon-14, the radioisotope of carbon, is naturally developed in trace amounts in the atmosphere and it can be detected in all ... The radioisotope carbon-14 is constantly formed from nitrogen-14 (14N) in the higher atmosphere by incoming cosmic rays which ... Carbon of all types is continually used to form the molecules of the cells of organisms. Doubling of the concentration of 14C ... The radioisotope 14C thus becomes part of the biosphere so that all living organisms contain a certain amount of 14C. Nuclear ...
... in contrast to other medical radioisotopes like carbon-11. Due to transport regulations for radioactive compounds, delivery is ... Israel's oxygen-18 facility had shut down due to the Gulf War, and the U.S. government had shut down its Isotopes of Carbon, ... Subsequently, a "nucleophilic synthesis" was devised with the same radioisotope. As with all radioactive 18F-labeled ... this molecule can soon be metabolized to carbon dioxide and water, after nuclear transmutation of the fluorine to oxygen ceases ...
Mars Geyser Hopper
Thus, this is an attractive mission for use of the Advanced Stirling Radioisotope Generator (ASRG) with a mass of 126 kilograms ... is a NASA design reference mission for a Discovery-class spacecraft concept that would investigate the springtime carbon ... The power technology that MGH proposed to use was the Advanced Stirling radioisotope generator (ASRG). NASA finished the ASRG ... Advanced Stirling radioisotope generator, Extraterrestrial aircraft, Hopping spacecraft). ...
Radioactivity in the life sciences
The decay of radioisotopes may limit the shelf life of a reagent, requiring its replacement and thus increasing expenses. ... For example, substituting a H-3 for a hydrogen atom or C-14 for a carbon atom does not change the conformation, structure, or ... Carbon-14 labeling is common in drug development to do ADME (absorption, distribution, metabolism and excretion) studies in ... In the case of the hydrogen isotope tritium (half-life = 12.3 years) and carbon-14 (half-life = 5,730 years), these isotopes ...
33 radioisotopes of neodymium have been detected as of 2022[update], with the most stable radioisotopes being the naturally ... Recently, the requirement for a low-carbon society has led to a significant demand for energy-saving technologies such as ... The ore, after being crushed and ground, is first treated with hot concentrated sulfuric acid, evolving carbon dioxide, ... and two radioisotopes with extremely long half-lives, 144Nd (alpha decay with a half-life (t1/2) of 2.29×1015 years) and 150Nd ...
Noble gas compound
... carbon, boron and even gold, as well as perxenic acid, several halides, and complex ions. The compound [Xe2]+[ ... clathrates of radioisotopes may provide suitable formulations for experiments requiring sources of particular types of ... and even with less electronegative elements such as nitrogen and carbon under certain circumstances. When the family of noble ...
Late Devonian extinction
Carbon in the form of plant matter would be produced on prodigious scales, and given the right conditions, could be stored and ... Detecting either of the long-lived, extra-terrestrial radioisotopes 146Sm or 244Pu in one or more end-Devonian extinction ... 5 (3). Carbon locked in Devonian coal, the earliest of Earth's coal deposits, is currently being returned to the atmosphere. ... Evidence exists of widespread anoxia in oceanic bottom waters; the rate of carbon burial shot up, and benthic organisms were ...
Nuclear thermal rocket
May 4th, 2022 Bennett, Gary (September 1990). "Safety Status of Space Radioisotope and Reactor Power Sources". Proceedings of ... and/or carbon dioxide (molecular mass 44). Nuclear thermal rockets using gaseous hydrogen propellant (molecular mass 2) ... as they are composed of materials such as carbon composites or carbides and are normally coated with zirconium hydride. Before ... thermal rocket engines Thermal rocket Fission-fragment rocket Nuclear electric rocket Nuclear pulse propulsion Radioisotope ...
Measures to mitigate global warming, such as a carbon tax or carbon emissions trading, may favor the economics of nuclear power ... The most common use of nuclear power in space is the use of radioisotope thermoelectric generators, which use radioactive decay ... low-carbon alternatives." Scientific data indicates that - assuming 2021 emissions levels - humanity only has a carbon budget ... Being a low-carbon energy source with relatively little land-use requirements, nuclear energy can have a positive environmental ...
Some early evidence for nuclear fission was the formation of a short-lived radioisotope of barium which was isolated from ... Actinides can coordinate the organic active groups or bind to carbon by the covalent bonds. The necessity of obtaining accurate ...
Isotopes of rutherfordium
There are 16 known radioisotopes from 253Rf to 270Rf (3 of which, 266Rf, 268Rf, and 270Rf are unconfirmed) and 4 isomers. The ... The reaction of californium-249 with carbon-13 was also investigated by the Ghiorso team, which indicated the formation of the ... In trying to confirm these results by using carbon-12 instead, they also observed the first alpha decays from 257Rf. The ...
Index of biochemistry articles
... carbon - carbon fixation - carboxylic acid - carcinoembryonic antigen - carrier - carrier protein - CAS registry number - ... quaternary structure radioisotope - radioisotopic labelling - Raman spectroscopy - random coil - Ras gene - Ras protein - ...
... radioisotopes are used in some radioisotope thermoelectric generators. Iridium is found in meteorites in much higher ... Hoyano, J. K.; Graham, W. A. G. (1982). "Oxidative addition of the carbon-hydrogen bonds of neopentane and cyclohexane to a ... The radioisotope iridium-192 is one of the two most important sources of energy for use in industrial γ-radiography for non- ... At least 37 radioisotopes have also been synthesized, ranging in mass number from 164 to 202. 192Ir, which falls between the ...
Parker Solar Probe
... and is made of two panels of reinforced carbon-carbon composite with a lightweight 4.5-inch-thick carbon foam core, which is ... the extreme variation in solar irradiance made for an expensive mission and required a radioisotope thermal generator for power ... An ion that enters EPI-Lo through one of the viewfinders first passes through two carbon-polyimide-aluminum foils and then ... EPI-Lo measures the spectra of electrons and ions and identifies carbon, oxygen, neon, magnesium, silicon, iron and two ...
Instead, the Cassini orbiter was powered by three GPHS-RTG radioisotope thermoelectric generators, which use heat from the ... The spacecraft passed through the plumes extending from its southern geysers, detecting water, carbon dioxide and various ... Variable Radioisotope Heater Units WAC: Wide Angle Camera XXM: Extended-Extended Mission Europlanet, data network Galileo, ... The General-Purpose Heat Source Radioisotope Thermoelectric Generator AIAA 2006-4096, 4th International Energy Conversion ...
Isotopes of boron
There are 13 radioisotopes that have been discovered, with mass numbers from 7 to 21, all with short half-lives, the longest ... while those with mass above 11 mostly become carbon. mB - Excited nuclear isomer. ( ) - Uncertainty (1σ) is given in concise ...
The radioisotope thermoelectric generator (RTG) power source has been proven in multiple spacecraft, and the extensive use of ... Titan is unique in having an abundant, complex, and diverse carbon-rich chemistry on the surface of a water-ice-dominated world ... MMRTGs convert the heat from the natural decay of a radioisotope into electricity. The rotorcraft will be able to travel ten ... Titan is a compelling astrobiology target because its surface contains abundant complex carbon-rich chemistry and because both ...
Craig used the carbon dioxide released from calcium carbonate fossils as a basis for future researches involving the carbon ... Craig developed new methods in radiocarbon dating and applied radioisotope and isotope distribution to various topics in marine ... His work laid the foundation for isotopic studies of the carbon cycle, and was fundamental to understanding carbon sequestering ... He is credited with establishing the field of carbon isotope geochemistry by characterizing carbon's stable isotopic signatures ...
There are many factors motivating further research on TEC including lower carbon emissions and ease of manufacturing. However, ... Since 1961, some unmanned spacecraft (including the Curiosity Mars rover) utilize radioisotope thermoelectric generators (RTGs ...
During combustion, carbon dioxide is released, and also nitrogen oxides, soot and other fine particulates. The carbon dioxide ... Radioisotope thermoelectric generators form a very small component of energy generation, mostly in specialized applications ... Examples of this carbon fixation occur in plants and microalgae. These fuels are made by a biomass conversion (biomass refers ... These fossil fuels are part of the carbon cycle and allow solar energy stored in the fuel to be released. The use of fossil ...
When tagged with the radioisotope carbon-11, martinostat can be used to quantify HDAC in the brain and peripheral organs using ...
A major use of systemic radioisotope therapy is in the treatment of bone metastasis from cancer. The radioisotopes travel ... Charged particles such as protons and boron, carbon, and neon ions can cause direct damage to cancer cell DNA through high-LET ... New techniques such as proton beam therapy and carbon ion radiotherapy which aim to reduce dose to healthy tissues will lower ... Targeting can also be achieved by attaching the radioisotope to another molecule or antibody to guide it to the target tissue. ...
... for carbon dioxide removal and air purification. Lithium hydroxide absorbs carbon dioxide from the air by forming lithium ... Seven radioisotopes have been characterized, the most stable being 8Li with a half-life of 838 ms and 9Li with a half-life of ... organolithium compounds function as strong bases and as reagents for the formation of carbon-carbon bonds. Organolithium ... 27 May 2020). "Carbon-Oxygen Classical Novae Are Galactic 7Li Producers as well as Potential Supernova Ia Progenitors". The ...
If a carbon-oxygen white dwarf accreted enough matter to reach the Chandrasekhar limit of about 1.44 solar masses (for a non- ... Fields, B. D.; Hochmuth, K. A.; Ellis, J. (2005). "Deep‐Ocean Crusts as Telescopes: Using Live Radioisotopes to Probe Supernova ... Standard Type Ia supernovae derive their energy from a runaway nuclear fusion of a carbon-oxygen white dwarf. The details of ... Röpke, F. K.; Hillebrandt, W. (2004). "The case against the progenitor's carbon-to-oxygen ratio as a source of peak luminosity ...
The innovative M5000 wind turbine has a compact medium speed drive train and carbon rotor blades. The patented air treatment to ... and the production of radioisotopes. Areva was a former corporate member of the Bruegel think tank. In January 2007, Areva was ... About 400 large steel forgings manufactured by Le Creusot Forge since 1965 found to have carbon-content irregularities that ...
99m Tc (OH2)3(CO)3]+, which is both water and air stable, is generated by reduction of 99m Tc O− 4 with carbon monoxide. This ... 99m Tc radioisotope generator. As the 99 Mo continuously decays to 99m Tc , the 99m Tc can be removed periodically (usually ... while the medically useful radioisotope 99m Tc O− 4 is eluted in the saline. The eluate from the column must be sterile and ...
de Hevesy, Georg (1962). Adventures in Radioisotope Research. New York: Pergamon Press. OCLC 12162216. Retrieved 20 June 2015. ... the process by which plants use light to convert carbon dioxide and water into more organic compounds. Biological processes ...
Index of chemistry articles
... carbonate Calcium oxide Californium calomel Calorimeter Canfieldite Carbohydrate carbon carbon dioxide Carbon group carbon ... radioisotope Radium Radon Radon difluoride Raman spectroscopy Raoult's law Redox Reduction Reflux Reversible reaction Rhazes ... Svante Arrhenius Syenite Sylvite synthetic radioisotope systematic element name Tabun Talc Talcum Tantalite Tantalum Tanzanite ...
Nuclear power phase-out
On the other hand measures to mitigate global warming, such as a carbon tax or carbon emissions trading, may favor the ... The main radioisotopes such as Tc-99m cannot effectively be produced without reactors. Most smoke detectors use americium-241, ... "Japan's carbon goal is based on restarting 30 nuclear reactors". 17 October 2021. "Nuclear power: When the steam clears". The ... The radioisotope most commonly used in diagnosis is technetium-99. Some 40 million procedures per year, accounting for about 80 ...
Behavior of nuclear fuel during a reactor accident
... carbon) to form two molecules of carbon monoxide. This is one of the processes which limits the working life of this type of ... Already the release of radioisotopes from fuel under different conditions has been studied. After the fuel has been used in the ... In the cases of carbon dioxide cooled graphite moderated reactors such as magnox and AGR power reactors an important corrosion ... reaction is the reaction of a molecule of carbon dioxide with graphite ( ...
Each penetrator was powered by a Radioisotope thermoelectric generator (RTG) and a battery. The expected lifetime of each ... carbon dioxide, ozone, and others, general global monitoring, pressure variations over time, and characterization of aerosols. ... carbon monoxide, aerosols, and temperature, in the middle and lower atmosphere, diagnostic of the ionosphere, global ... variations of water and carbon monoxide in space and time, and the optical depth, phase function, size distribution, and ...
The abundance of nitrogen, carbon and sulfur was three times that of the Sun, raising the possibility that they had been ... over what they perceived as an unacceptable risk to the public's safety from the plutonium in the Galileo's radioisotope ... and the probe's carbon phenolic heat shield lost more than half of its mass during the descent. At the time, this was by far ...
Carbon Radioisotopes | [email protected]
Carbon Radioisotopes * Subject Areas on Research. * A kinetic study of embryonic cell adhesion. ... Synthesis of 11C-labeled chlorpromazine directly from [11C]carbon dioxide. * Synthesis of the labeled D1 receptor antagonist ... A sensitive, specific radioisotope assay for L-glutamine-D-fructose-6-phosphate aminotransferase. ... Environmental biodegradability of [¹⁴C] single-walled carbon nanotubes by Trametes versicolor and natural microbial cultures ...
Inhibition of cholesterol biosynthesis by organosulfur compounds derived from garlic
Geoscience Research Institute | How Solid is a Radioisotope Age of a Rock?
Radioisotope ages are calculated from ratios of certain atoms. The isotopic ratios can be precisely measured, but the ... What is the basis of carbon-14 dating? What materials can be dated by carbon-14? How accurate are carbon-14 dates? What are the ... the radioisotope age of the mineral that contains the parent and daughter atoms. It is reasonable to expect that a radioisotope ... How would carbon-14 dating be affected by a global flood? What unsolved problems about carbon-14 dating are of greatest ...
Alteration of blood-brain barrier in human brain tumors: comparison of [18F]fluorodeoxyglucose, [11C]methionine and rubidium-82...
Radioisotopes in Medicine | Nuclear Medicine - World Nuclear Association
Tens of millions of nuclear medicine procedures are performed each year, and demand for radioisotopes is increasing rapidly ... the use of radioisotopes for diagnostics, radiation therapy, radiopharmaceuticals and other beneficial medical uses of nuclear ... Carbon-11, Nitrogen-13, Oxygen-15, Fluorine-18:. These are positron emitters used in PET for studying brain physiology and ... Home / Information Library / Non-power Nuclear Applications / Radioisotopes & Research / Radioisotopes in Medicine ...
3' Paramount Ductless Enclosure, Tall - Labconco
Activated Carbon Radioisotope SDS. Safety Data Sheet for Activated Carbon Filters used in Paramount Ductless Enclosures, ... Acid Impregnated Carbon Filter SDS. Safety Data Sheet for the Acid Impregnated Carbon Filters used in FilterMate Portable ... Ammonia Impregnated Carbon Filter SDS. Safety Data Sheet for the Ammonia Impregnated Carbon Filters used in FilterMate Portable ... Formaldehyde Impregnated Carbon Filter SDS. Safety Data Sheet for the Formaldehyde Impregnated Carbon Filters used in ...
Biblio | Page 13 | Linus Pauling Institute | Oregon State University
Can Radioisotope Dating Be Trusted? | The Creation Podcast: Episode 36 | The Institute for Creation Research
Chemical Forums: Tokamak produces radioisotopes
But what reactions are missing in the Janis book, what do the neutrons produce? Oxygen, carbon and more impurities in beryllium ... Or they can produce useful radioisotopes, by 98Mo(n,g)99Mo or other. This would favour heavy water.. Marc Schaefer, aka ... Re: Tokamak produces radioisotopes « Reply #30 on: July 31, 2022, 11:34:34 AM » ... Re: Tokamak produces radioisotopes « Reply #31 on: August 06, 2022, 11:43:38 AM » ...
Browsing by Subject "Radioisotopes"
Selected radionuclides: tritium, carbon-14, krypton-85, strontium-90, iodine, caesium-137, radon, plutonium ... Utilisation des rayonnements ionisants et des radio-isotopes à des fins médicales : rapport d un comité mixte AIEA/OMS d ... Joint IAEA/WHO Expert Committee on the Medical Uses of Ionizing Radiation and Radioisotopes; World Health Organization; ... Joint IAEA/WHO Expert Committee on the Medical Uses of Ionizing Radiation and Radioisotopes; World Health Organization; ...
Treatment and Disposal of Irradiated Graphite and Other Carbonaceous Waste | CARBOWASTE Project | Fact Sheet | FP7 | CORDIS |...
During operation, the graphite and other carbonaceous materials like carbon brick, pyrocarbon and silicon carbid... ... About 250000 t of i-carbon are existing, worldwide. Acceptable solutions have not yet been established to handle this kind of ... These irradiated carbonaceous wastes are problematic due to their content of long-lived radioisotopes (e.g. Carbon14, Chlorine ... During operation, the graphite and other carbonaceous materials like carbon brick, pyrocarbon and silicon carbide coatings are ...
Carbon-14 diamonds TalkOrigins
They say Radioisotope evidence presents significant problems for the young earth position. Baumgardner and the RATE team are to ... Carbon-14 in diamonds: Refuting Talk.Origins. C S from United States wrote in:. iStockphoto I was looking at talk origins ... Diamonds, being primarily carbon and with atoms in a tightly packed crystal lattice, are quite impervious to contamination. Yet ... Since the global flood would have buried huge numbers of carbon-containing living things (which formed much of todays coal, ...
ALEC Exposed: Warming Up to Climate Change | PR Watch
... polluting industries and the politicians that serve them want to convince you that excess carbon dioxide in the atmosphere is ... the radioisotope of normal C12 carbon. Since fossil fuels derive from plant decay, they both have about 2% lower C13/C12 ratios ... Carbons the Culprit stevor, You have been misled. Claim: Its cosmic rays. This idea is refuted at sketicalscience.com on ... More detailed global carbon inventories confirm it. A. One Back of the Envelope Calculation makes it pretty definite and it is ...
New Oak Ridge centre to boost US isotope production - Physics World
Correction 23/11: An earlier version of the article suggested that SIPRC will be able to produce radioisotopes for medical ... These include lutetium-177 and carbon-14 as well as technetium-99m. Sutharshan notes that, while other US laboratories can ... "Some important isotopes come from Russia - the only other country capable of producing radioisotopes in large quantities." ... It will instead produce stable isotopes that are then used elsewhere as target material to make radioisotopes. ...
Paragenesis of Palladium-Cobalt Nanoparticle in Nitrogen-Rich Carbon Nanotubes as a Bifunctional Electrocatalyst for Hydrogen...
Paragenesis of Palladium-Cobalt Nanoparticle in Nitrogen-Rich Carbon Nanotubes as a Bifunctional Electrocatalyst for Hydrogen- ... Co-60, a commercially important radioisotope, is useful as a radioactive tracer and gamma ray source. The origin of the word ... Carbon. 6 C 12.010700000 Carbon See more Carbon products. Carbon (atomic symbol: C, atomic number: 6) is a Block P, Group 14, ... amorphous carbon, glassy carbon, and nanostructured forms such as carbon nanotubes, fullerenes, and nanofibers . Carbon is at ...
NASA Mulling Life-Hunting Mission to Saturn Moon Enceladus | Space
But the two are far from carbon copies. The school-bus-size Cassini, for example, cost $3.2 billion and features 12 onboard ... Cassini is also powered by three radioisotope thermoelectric generators (RTGs), which convert the heat of plutonium-238s ... In 2005, NASAs Saturn-orbiting Cassini spacecraft spotted geysers of water ice, salts, carbon-containing organics and other ...
Museum Library | Museum of Radiation and Radioactivity
Maximum Permissible Amounts of Radioisotopes in the Human Body and Maximum Permissible Concentrations in Air and Water NBS ... Recommendations for the Disposal of Carbon-14 Wastes NBS Handbook 53. *Protection Against Betatron-Synchrotron Radiations up to ... Contributions and Future of Radioisotopes in Medical, Industrial, and Space Applications. 1990. Tingey, Dix and Wahlquist. PNL- ...
Division of Research Safety | Illinois
Open containers, such as cell culture dishes containing radioisotopes, can be covered with carbon-impregnated paper. ... Clearly label all radioisotopes and calibration sources. Stock solutions of radioisotopes should be clearly labeled with the ... Using Radioisotopes in Animals Research with vertebrate animals must be approved by the Institutional Animal Care and Use ... A Radioisotope Use and Waste Log is available on the DRS website. The online inventory is updated automatically whenever ...
Free Positron emission tomography Essays and Papers | 123 Help Me
Bibliography 7 Appendice 1 8 CARBON 11 WHAT IS CARBON 11? 11C or more commonly known as Carbon 11 is a radioisotope of Carbon ( ... Radioisotopes and their Medical Uses. A radioisotope is an isotope that emits radiation as it has nuclear instability(Prostate ... This radioisotope decays to Boron 11 due to beta plus decay or positron emission. Conversely this change can be a result of ... However, there are much more positive uses for radioisotopes. There have been many medical advances thanks to the benefit and ...
2020-21 Brazil Winner, Grade 5-6 - Topic: Oberon | Winners - NASA RPS: Radioisotope Power Systems
This moon is composed of about 50% water ice, 30% silicates and 20% of methane, carbon and nitrogen. Its surface is covered by ... Radioisotope Power Systems (RPS) have provided the power to explore some of the deepest, darkest, and most distant destinations ... NASAs second Power to Explore Challenge inspires learning about how radioisotope power systems help us explore the extremes of ... A team of scientists and engineers sponsored by NASAs Radioisotope Power Systems Program won the American Nuclear Societys ...
Radioisotope thermoelectric generator - Wikipedia
Reaction of strontium carbonate with titanium dioxide at high temperature produces the desired strontium titanate plus carbon ... A radioisotope thermoelectric generator (RTG, RITEG), sometimes referred to as a radioisotope power system (RPS), is a type of ... Electrostatic-boosted radioisotope heat sources. A power enhancement for radioisotope heat sources based on a self- ... Multi-Mission Radioisotope Thermoelectric Generator. NASA has developed a multi-mission radioisotope thermoelectric ...
Plant & Soil Sciences | Graduate Program Finder | University of Delaware
Neocortical abnormalities of [11C]-flumazenil PET in mesial temporal lobe epilepsy<...
Two ancient human genomes reveal Polynesian ancestry among the indigenous Botocudos of Brazil - Fingerprint - Penn State
Anna Sapfo Malaspinas, Oscar Lao, Hannes Schroeder, Morten Rasmussen, Maanasa Raghavan, Ida Moltke, Paula F. Campos, Francisca Santana Sagredo, Simon Rasmussen, Vanessa F. Gonçalves, Anders Albrechtsen, Morten E. Allentoft, Philip L.F. Johnson, Mingkun Li, Silvia Reis, Danilo V. Bernardo, Michael Degiorgio, Ana T. Duggan, Murilo Bastos, Yong WangJesper Stenderup, J. Victor Moreno-Mayar, Søren Brunak, Thomas Sicheritz-Ponten, Emily Hodges, Gregory J. Hannon, Ludovic Orlando, T. Douglas Price, Jeffrey D. Jensen, Rasmus Nielsen, Jan Heinemeier, Jesper Olsen, Claudia Rodrigues-Carvalho, Marta Mirazón Lahr, Walter A. Neves, Manfred Kayser, Thomas Higham, Mark Stoneking, Sergio D.J. Pena, Eske Willerslev ...
Simultaneous Determination of Total Carbon and Carbon-14 Activity - [scite report]
Simultaneous Determination of Total Carbon and Carbon-14 Activity - Gabourel, J. D., Baker, M. J., Koch, C. W. ... It is hoped that from such a compilation the analyst will discover uses for radioisotopes in his own work, realizing that this ... Of probable interest to many is a method providing for the simultaneous determination of total carbon and carbon-14 activity in ... Of probable interest to many is a method providing for the simultaneous determination of total carbon and carbon-14 activity in ...
Rare radioisotopes at the ready The study of rare isotopes, including many in the f-block, is a key step to advancing our ... The direct carbon isotope exchange reaction on α-amino acids is highly desirable, as existing labelling methods require several ... Diastereo- and enantioselective synthesis of compounds with a trifluoromethyl- and fluoro-substituted carbon centre Methods to ... access organofluorine compounds with a trifluoromethyl- and fluoro-substituted carbon stereogenic centre are severely limited. ...
Where do deep space probes get their power?
... radioisotope power systems give life to probes, landers and rovers in places beyond the reach of the suns power. Jake Port ... Known as radioisotope power systems, these fairly simple sources of electricity and heat have been powering most of NASAs ... This is then contained within more protective layers, consisting of a graphite impact shell, a carbon fibre sleeve and an outer ... To find out more about how radioisotope thermoelectric generators are used, and how we are about to run out of the valuable ...
How radioactive is the human body? | Live Science
"Most of these radioisotopes make their way into our bodies through the food we eat, the water we drink and the air we breathe ... The biggest sources of radiation in our bodies are trace amounts of carbon 14 and potassium 40, said Mike Short, an associate ... Radioactive isotopes, like carbon 14 and a hydrogen isotope known as tritium, are the "daughter" products of heavier elements ... we take in only about 0.39 milligrams of potassium 40 and 1.8 nanograms of carbon 14 a day. The amount of radioactivity caused ...
Instructions to UK Govt for 2010 | IanPJ on Politics
Roadmap for low carbon energy system by 2050 [21 KB]. Yes. Communication on nuclear medicine and radioisotopes [20 KB]. No. ... Communication on roadmap for low-carbon economy by 2050, also with a view to determining the necessary scenarios for 2030 [19 ... Communication on public procurement with focus on how to underpin Europe 2020 priorities: innovation, low carbon investment, ... it is commercialising itself with bond issues through the ECB and is about to launch the latest carbon credits market. ...
Thermoelectric generatorPhotosynthetically fixed carbon2022AtomsDioxideNitrogenParticulateFume hoodsContaminationTomographySubstancesCassiniNuclearOrganicEmissionsConcentrationsPlutonium-238ContainmentGraphiteGreenhousePotassiumAllocationEmphasizeDynamicsWidespreadCommerciallyRadiationNASABiologicalSpecificationsDiagnosticAtomicApplicationsSystemsImportantReduceOxygenGeneral purposLongHeatActivityMaterialsProduceMakeIncludeWorldwideRelease
- A radioisotope thermoelectric generator ( RTG , RITEG ), sometimes referred to as a radioisotope power system (RPS), is a type of nuclear battery that uses an array of thermocouples to convert the heat released by the decay of a suitable radioactive material into electricity by the Seebeck effect . (wikipedia.org)
- NASAs New Horizons spacecraft was powered all the way to Pluto and beyond by a spare radioisotope thermoelectric generator left over from the Cassini mission. (cosmosmagazine.com)
- At the heart of an radioisotope thermoelectric generator is the general purpose heat source module, which contains the plutonium-238 within a protective iridium case. (cosmosmagazine.com)
- Four pellets of plutonium-238 can be contained within each heat source module, with eight stacked inside the radioisotope thermoelectric generator to produce enough power for normal function for decades. (cosmosmagazine.com)
- You can see this all in a video by NASA, below, in the inner components of a radioisotope thermoelectric generator are on display. (cosmosmagazine.com)
- Let us tell you that the radioisotope thermoelectric generator was also included in the Apollo 13 mission to the moon, but due to failure, it broke into the atmosphere and near the Tonga Trench. (worldwidewebtimes.com)
- Explain that the radioisotope thermoelectric generator contained 3.9 kg of plutonium 238. (worldwidewebtimes.com)
Photosynthetically fixed carbon2
- Calculations of the carbon balance for the unfed colonies showed that DOC release represents ca 14% of the net daily photosynthetically fixed carbon. (int-res.com)
- Through these partnerships, resources are exchanged including photosynthetically fixed carbon for fungal-acquired nutrients. (bvsalud.org)
- A team of scientists and engineers sponsored by NASA's Radioisotope Power Systems Program won the American Nuclear Society's 2022 Best Radioisotope Power Paper award. (nasa.gov)
- The steady spontaneous transmutation of a radioactive isotope into a stable daughter isotope provides a means for determining the length of time the accumulation of daughter atoms has been maintained in association with its parent source the radioisotope age of the mineral that contains the parent and daughter atoms. (grisda.org)
- The attributes of naturally decaying atoms, known as radioisotopes, give rise to several applications across many aspects of modern day life (see also information paper on The Many Uses of Nuclear Technology ). (world-nuclear.org)
- Diamonds, being primarily carbon and with atoms in a tightly packed crystal lattice, are quite impervious to contamination. (creation.com)
- As the U.S. suffers through catastrophic tornadoes, heat waves, and other climate extremes -- no doubt just a small taste of what the climate crisis will bring in the future -- polluting industries and the politicians that serve them want to convince you that excess carbon dioxide in the atmosphere is actually a good thing. (prwatch.org)
- In 2009, the EPA made its " Finding ," that "the current and projected concentrations of the six key well-mixed greenhouse gases -- carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O), hydrofluorocarbons (HFCs), perfluorocarbons (PFCs), and sulfur hexafluoride (SF6) -- in the atmosphere threaten the public health and welfare of current and future generations. (prwatch.org)
- Keen guarantees commercial cga specifications, form carbon dioxide gas bubble formation in. (bqueennatural.com)
- Here liquid sulfur, carbon dioxide, and active alkaline mod come out of the trench. (worldwidewebtimes.com)
- Paragenesis of Palladium-Cobalt Nanoparticle in Nitrogen-Rich Carbon Nanotubes as a Bifunctional Electrocatalyst for Hydrogen-Evolution Reaction and Oxygen-Reduction Reaction. (americanelements.com)
- This moon is composed of about 50% water ice, 30% silicates and 20% of methane, carbon and nitrogen. (nasa.gov)
- ABSTRACT: Corals are known to release large amounts of particulate and dissolved organic carbon (POC and DOC) and nitrogen (PON and DON). (int-res.com)
- graphite is rich in the carbon-14 radioisotope, which undergoes beta decay into nitrogen, releasing an anti-neutrino and a beta decay electron in the process. (wordpress.com)
- Paramount Ductless Enclosures are capable of using both carbon and 99.99% efficient HEPA filters for removing gaseous and particulate contaminants. (labconco.com)
- Paper discusses the testing conducted on the Paramount Ductless Enclosure that shows carbon filter effectiveness and fume and particulate containment of particulates. (labconco.com)
- The forest sites have shown the highest total and particulate organic carbon values. (essopenarchive.org)
- Paramount Ductless Enclosures are self-contained work stations, also known as ductless fume hoods, that use carbon filters to rid the laboratory of annoying or unsafe concentrations of organic solvents, formaldehyde, acid gases, ammonia, or radioisotopes. (labconco.com)
- Vacuum pumps used in systems containing radioisotopes should be used in fume hoods with proper flow rates. (illinois.edu)
- In an attempt to defend the paradigm of millions of years, some propose that the coal samples could have been contaminated in situ by migration of Carbon14 from the atmosphere to the Coal Seam, double capture of thermal neutrons produced by fission of uranium in the surrounding rock, or by contamination with modern carbon during the testing process. (creation.com)
- Some evolutionists, realizing that they cannot appeal to contamination in situ with diamonds, attempt to dismiss this problem by simply appealing to the possibility of contamination by modern carbon during the testing process. (creation.com)
- In recent years specialists have also come from radiology, as dual PET/CT (positron emission tomography with computerized tomography) procedures have become established, increasing the role of accelerators in radioisotope production. (world-nuclear.org)
- Design and Main Outcome Measure In a between-group comparison, we used positron emission tomography and the benzodiazepine receptor ligand flumazenil labeled with carbon 11 to assess the regional brain pattern of receptor binding. (ox.ac.uk)
- Recommendations include better housekeeping practices for radioisotopes, improved hood ventilation to increase air flow, and maintenance of an inventory of hazardous substances in each laboratory. (cdc.gov)
- In 2005, NASA's Saturn-orbiting Cassini spacecraft spotted geysers of water ice, salts, carbon-containing organics and other molecules erupting from the south polar region of the 310-mile-wide (500 kilometers) Enceladus. (space.com)
- Over 40 million nuclear medicine procedures are performed each year, and demand for radioisotopes is increasing at up to 5% annually. (world-nuclear.org)
- In developed countries (a quarter of the world population) about one person in 50 uses diagnostic nuclear medicine each year, and the frequency of therapy with radioisotopes is about one-tenth of this. (world-nuclear.org)
- The most common radioisotope used in diagnosis is technetium-99 (Tc-99), with some 40 million procedures per year, accounting for about 80% of all nuclear medicine procedures and 85% of diagnostic scans in nuclear medicine worldwide. (world-nuclear.org)
- Nuclear power plants for the stars, radioisotope power systems give life to probes, landers and rovers in places beyond the reach of the sun's power. (cosmosmagazine.com)
- The biggest sources of radiation in our bodies are trace amounts of carbon 14 and potassium 40, said Mike Short, an associate professor of nuclear science and engineering at MIT. (livescience.com)
- Alternative fuels, also known as non-conventional and sophisticated fuels, are dominant sources that can be used as fuels in comparison to basic fossil fuels such as petroleum and coal, nuclear materials such as uranium and thorium, and artificial radioisotope fuels produced in nuclear reactors. (reportsanddata.com)
- As well as contributing to achieving our net-zero commitments, new nuclear will complement renewable energy to ensure that the UK has a resilient, low-cost, low-carbon electricity system for the long term. (theyworkforyou.com)
- NDB has the potential to solve the major global issue of carbon emissions in one stroke without the expensive infrastructure projects, energy transportation costs, or negative environmental impacts associated with alternate solutions such as carbon capture at fossil fuel power stations, hydroelectric plants, turbines, or nuclear power stations. (wordpress.com)
- Volcanics associated with organic material that can be dated by radioactive carbon generally have a K-Ar age much greater than that given by radiocarbon for the eruption (Stapor and Tanner 1973). (grisda.org)
- Filters used in the Paramount are sold separately and come in seven types Ammonia-Amine, Acid-Sulfur, Organic Vapor, Formaldehyde-Formalin, Radioisotope, Mixed Bed and HEPA. (labconco.com)
- Serpentinization of ultramafic rocks that are the major components of the oceanic lithosphere produces highly reductive fluids, in which transformation of inorganic carbon species to organic matter occur (e.g. (springeropen.com)
- Soil carbon is intimately related to the living part of the organic matter, as represented by the soil microbial biomass, which mediates the decomposition, mineralization, and immobilization of organic carbon available in soils under different land-use systems. (essopenarchive.org)
- They all contribute to decrease in overall carbon emissions. (reportsanddata.com)
- The data treated in RADIOISOTOPES fully indicate that Earth's crust contains concentrations of radiogenic isotopes many orders-of-magnitude greater than could have accumulated in 6000 years at present rates of radioactivity. (grisda.org)
- A type of radioisotopic power system known as radioisotope thermoelectric generators employ radioactive materials such as plutonium-238 to produce heat and make use of a principle of electrics known as the Seebeck effect to produce power. (cosmosmagazine.com)
- Safe use of RTGs requires containment of the radioisotopes long after the productive life of the unit. (wikipedia.org)
- During operation, the graphite and other carbonaceous materials like carbon brick, pyrocarbon and silicon carbide coatings are contaminated by fission products and neutron activation. (europa.eu)
- This is then contained within more protective layers, consisting of a graphite impact shell, a carbon fibre sleeve and an outer case known as the aeroshell. (cosmosmagazine.com)
- NDB takes this graphite, purifies it and uses it to create tiny carbon-14 diamonds. (wordpress.com)
- In addition to individual state laws regulating carbon, regional initiatives sprang up, such as the Regional Greenhouse Gas Initiative in ten Northeastern and Mid-Atlantic states and, later, the Western Climate Initiative, which includes U.S. states, Mexican states, and Canadian provinces throughout the western half of the continent. (prwatch.org)
- Lack of chemical isolation generally (but not always) has been expected to produce radioisotope ages that are most likely to be younger than the correct real time age, particularly when the daughter isotope is highly mobile, as is the case for the inert gas (argon) produced by the radioactive decay of potassium. (grisda.org)
- Though these isotopes make up most of our body's radiation, we take in only about 0.39 milligrams of potassium 40 and 1.8 nanograms of carbon 14 a day. (livescience.com)
- In this study, we examined mycorrhizal nutrient and host resource allocation in potato with and without AMF and PCN using radioisotope tracing, whilst determining the consequences of such allocation. (bvsalud.org)
- Effect of drought on soil microbial metabolisms driving carbon allocation and volatil. (essopenarchive.org)
- It was felt, however, that this type of review should emphasize the widespread use of radioisotopes in analysis today. (scite.ai)
- However, many questions on how the mechanisms function and shape carbon dynamics and the ocean carbon cycle remain unknown. (us-ocb.org)
- Forest-to-agriculture conversion and land-use change often lead to a loss in microbial biomass carbon (MBC) and shifts in microbial activity, directly influencing the soil carbon dynamics. (essopenarchive.org)
- There is widespread awareness of the use of radiation and radioisotopes in medicine, particularly for diagnosis (identification) and therapy (treatment) of various medical conditions. (world-nuclear.org)
- Co-60, a commercially important radioisotope, is useful as a radioactive tracer and gamma ray source. (americanelements.com)
- Shielded syringes are commercially available for manipulation of liquids containing high energy radioisotopes. (illinois.edu)
- Completely encasing the radioactive carbon-14 diamond is a layer of cheap, non-radioactive, lab-created carbon-12 diamond, which contains the energetic particles, prevents radiation leaks and acts as a super-hard protective and tamper-proof layer. (wordpress.com)
- Funding for the Ocean Carbon & Biogeochemistry Project Office is provided by the National Science Foundation (NSF) and the National Aeronautics and Space Administration (NASA). (us-ocb.org)
- To be suitable for geologic time scale calibration a radioisotope age must meet three requirements: chemical isolation, stratigraphic control, and biological control. (grisda.org)
- To be desirable as a calibration of the Phanerozoic time scale, a radioisotope age should also meet standards of biological control, i.e., it should relate to a mineral sample that is associated with the proper index fossils for the age in question. (grisda.org)
- Radioisotope ages that are younger than what would be expected on the basis of stratigraphic control and biological control are usually accounted for as evidence that chemical isolation has not been maintained. (grisda.org)
- Radioisotope ages that are older than allowable on the basis of stratigraphic or biological control are explained as due to retention of daughter isotopes from a state in which the mineral components existed previous to the association in which they are now found. (grisda.org)
- This compilation is especially relevant to present and future investigations of the biological carbon pump (BP), which transports carbon to the deep ocean and regulates atmospheric CO 2 levels. (us-ocb.org)
- Although the primary motivation for the preparation of this book is to foster development of compatible understanding of radioisotope data and the chronological specifications in the Bible, the book is a valuable resource for individuals who do not share this concern. (grisda.org)
- Diagnostic procedures using radioisotopes are now routine. (world-nuclear.org)
- Radioisotopes are an essential part of medical diagnostic procedures. (world-nuclear.org)
- Carbon (atomic symbol: C, atomic number: 6) is a Block P, Group 14, Period 2 element. (americanelements.com)
- Construction has begun on a new facility in the US that will produce a wide range of isotopes including those that can be used to make radioisotopes for medical applications. (physicsworld.com)
- An earlier version of the article suggested that SIPRC will be able to produce radioisotopes for medical applications. (physicsworld.com)
- Applications of radioisotopes in carbon dating! (allysonabrams.com)
- Cover crops and N applications improved soil enzymes for carbon and N cycling. (essopenarchive.org)
- NASA's second Power to Explore Challenge inspires learning about how radioisotope power systems help us explore the extremes of our solar system. (nasa.gov)
- Radioisotope Power Systems (RPS) have provided the power to explore some of the deepest, darkest, and most distant destinations in the solar system and beyond. (nasa.gov)
- if there is one conclusive observation to be made, it is that the 'ages' derived from radioisotope systems can really only be regarded as maximum ages given the evidence of open-system behavior, mixing, inheritance, etc. (grisda.org)
- Sterilization of medical equipment is also an important use of radioisotopes. (world-nuclear.org)
- Some important isotopes come from Russia - the only other country capable of producing radioisotopes in large quantities. (physicsworld.com)
- There are open-system processes that can reduce, as well as those that can increase a radioisotope 'age' characteristic. (grisda.org)
- How carbon monoxide, oxygen supports combustion is oxygen a chemical property? (bqueennatural.com)
- In a Stirling radioisotope system, heat must continually be removed from the General Purpose Heat Source (GPHS) modules to maintain the modules and surrounding insulation at acceptable temperatures. (1-act.com)
- In a Stirling radioisotope power system, one or more General Purpose Heat Source (GPHS) modules supply heat to a Stirling convertor (Stirling engine with an integrated linear alternator). (1-act.com)
- These irradiated carbonaceous wastes are problematic due to their content of long-lived radioisotopes (e.g. (europa.eu)
- The CARBOWASTE project aims at an integrated waste management approach for this kind of radioactive wastes which are mainly characterized as Intermediate Level Waste (ILW), due to the varying content of long-lived radioisotopes. (europa.eu)
- An alkali-metal Variable Conductance Heat Pipe (VCHP) has been designed to allow multiple stops and restarts of the Stirling convertor in an Advanced Stirling Radioisotope Generator (ASRG). (1-act.com)
- In the present work, we have developed a facile pyrolysis-based process for the co-synthesis of palladium-cobalt nanoparticles supported on carbon nanotubes (Pd-CoCNTs), which exhibit superior catalytic activity for the HER and enhanced ORR performance. (americanelements.com)
- Carbon dating is a common method used to determine the ages of fossils and other materials, but carbon14 deteriorates quite quickly. (icr.org)
- Work with hazardous materials on impervious benchtops and dedicate an area for work with radioisotopes. (illinois.edu)
- Stable isotopes that SIPRC might produce are needed as target material for such radioisotopes. (physicsworld.com)
- It will instead produce stable isotopes that are then used elsewhere as target material to make radioisotopes. (physicsworld.com)
- Most of these radioisotopes make their way into our bodies through the food we eat, the water we drink and the air we breathe," Short told Live Science. (livescience.com)
- These include lutetium-177 and carbon-14 as well as technetium-99m. (physicsworld.com)
- 1984) have recently reported an extensive study of 32 typical worldwide granulite samples that have geologic age assignments ranging from 20 to 3100 m.y., yet have samarium-neodymium (Sm-Nd) radioisotope ages that in most cases are greater than the geologic ages and range from 851 to 3744 m.y. (grisda.org)
- Over 10,000 hospitals worldwide use radioisotopes in medicine, and about 90% of the procedures are for diagnosis. (world-nuclear.org)
- About 250000 t of i-carbon are existing, worldwide. (europa.eu)
- In order to investigate several aspects of carbon and nutrient cycling in corals, release of DOC and DON by fed and unfed colonies of the zooxanthellate coral Galaxea fascicularis (Linnaeus 1767) was measured in the laboratory under controlled conditions. (int-res.com)
- We measured DOC and DON fluxes from corals using the high temperature catalytic oxidation method and DOC release as 14 C-photosynthate using a radioisotope technique. (int-res.com)
- The GPHS module is designed so that it will not release radioisotopes, even under such postulated events as a launch vehicle explosion, or reentry through the earth's atmosphere. (1-act.com)