(n.) A mineral of a brown to black color, or, as in the variety orangite, orange-yellow. It is essentially a silicate of thorium.
Example Sentences:
Thorium
Definition:
(n.) A metallic element found in certain rare minerals, as thorite, pyrochlore, monazite, etc., and isolated as an infusible gray metallic powder which burns in the air and forms thoria; -- formerly called also thorinum. Symbol Th. Atomic weight 232.0.
Example Sentences:
(1) Plain abdominal radiography demonstrated calcification in three patients and evidence of Thorotrast (thorium dioxide) deposition in one.
(2) Electron energy-loss spectroscopic element-distribution images are acquired from cytochemical reaction products in a variety of cellular objects: (1) colloidal thorium particles in extra-cellular coat material, (2) iron-containing ferritin particles in liver parenchymal cells, (3) barium-containing reaction products in endoplasmic reticulum stacks, (4) elements present in lysosomal cerium- and barium-containing precipitates connected with acid phosphatase (AcPase) or aryl sulphatase (AS) enzyme activity.
(3) In the spectrophotometric method, a change of the absorbance of thorium-morin complex is used as a measure of diphosphonate concentration.
(4) The endo- and perilymphatic glycocalyx of the cochlear epithelia were investigated ultrastructurally in normal and hydropic cochleas using the electron-dense markers cationized ferritin and colloidal thorium.
(5) The cultures were then incubated for varying periods in a colloidal suspension of thorium dioxide, and the pinocytotic uptake of this marker was followed by electron microscopy.
(6) Such a diagnosis can be made without a history of thorium dioxide administration, which often may not be available.
(7) • Examining new technologies including thorium reactors, which cannot meltdown, and fast reactors, which can be fuelled by waste plutonium.
(8) Dose-response curves for chronic leukemia in A-bomb survivors and liver tumors in patients given Thorotrast (colloidal thorium dioxide) show large threshold effects.
(9) The contamination with the natural radioelements (potassium, radium, thorium) as well as their limited absorption by the gastrointestinal tract, their metabolism in organism, and their radiotoxicological characteristics do not create radiological threat to animals.
(10) A case of hepatoma induced by thorium dioxide (Thorotrast) is reported.
(11) The data indicate (1) that approximately 90% of injected Thorotrast is retained in the body for a prolonged period, but about 50% of radium and 10% of radon produced from thorium are eliminated from the body, (2) that the mean steady state activity ratios of 224Ra and 212Pb to 228Th for liver are 0.56 and 0.28, and 0.54 and 0.16 for spleen, 0.58 and 0.82 for lungs, respectively, and (3) that the parent 228Th is translocated to the bone.
(12) Sixty to 80% of the thorium activity in bones containing red marrow was located in the marrow.
(13) The role of thorium in the etiology of possibly two successive hematopoietic neoplasms is discussed.
(14) Summary--Thorotrast (thorium dioxide) is a contrast material which was first used for angiography about 40 years ago.
(15) A second follow-up of mortality was carried out for workers employed in a thorium-processing plant between 1915 and 1973.
(16) In 2009, the potential of LFTRs was highlighted in the Guardian's Manchester Report , and September this year saw the launch of the Weinberg Foundation , a new pressure group seeking to accelerate the development of thorium technology.
(17) The radioactive noble gas radon, a member of the natural decay chains of uranium and thorium, enters the indoor environment in regionally highly diverging amounts.
(18) Also, with the world's supply of uranium rapidly depleting, attention has refocused on thorium, which is three to four times more abundant and 200 times more energy dense.. "Given India's abundant supply of thorium it makes sense for her to develop thorium reactors," said Labour peer Baroness Worthington who is patron of the Weinberg Foundation, which promotes thorium-fuelled nuclear power.
(19) Review of three facial biopsies revealed collections of Thorotrast-laden histiocytes and free thorium dioxide within a background of chronic inflammation and dermal fibrosis.
(20) Previous cases of osteosarcoma associated with Thorotrast administration from the literature are cited, and possible causal relationships are discussed between thorium retention in bone and neoplastic transformation by chronic radiation.