(n.) A rare element, recently discovered (1885), in a silver ore (argyrodite) at Freiberg. It is a brittle, silver-white metal, chemically intermediate between the metals and nonmetals, resembles tin, and is in general identical with the predicted ekasilicon. Symbol Ge. Atomic weight 72.3.
Example Sentences:
(1) Except for one control group, the other three groups were subdivided into six groups and administered three different kinds of germanium (inorganic germanium, organic germanium, and natural organic germanium) one month before and during dimethylhydrazine treatment, and during dimethylhydrazine treatment, respectively.
(2) Although the actual mechanism involved is not clear, the evidence of the inhibition of senile amyloidosis by organic germanium may give a light to elucidate the pathogenesis of amyloidosis.
(3) This review examines the toxicity and accumulation of germanium and silver in selected microbial species.
(4) However, if an electric field is applied across the membrane, germanium reflection elements would be preferred because of their low electric resistance (approximately 50 omega cm).
(5) In high concentrations, germanium was toxic to the limpets and killed them.
(6) The incidence of intestinal cancer in the control group (dimethylhydrazine only) was 91 percent; in groups provided with inorganic germanium one month before and during dimethylhydrazine treatment, and during dimethylhydrazine treatment only, it was 91 and 78 percent; in groups provided with organic germanium one month before and during dimethylhydrazine treatment, and during dimethylhydrazine treatment only, it was 64 and 64 percent; in groups provided with natural organic germanium one month before and during dimethylhydrazine treatment and during dimethylhydrazine treatment only, it was 50 and 45 percent.
(7) It has turned out that good adhesion of uncharged and negatively charged model membranes to germanium plates is achieved when they are coated with a monomolecular layer of aminopropylsilane.
(8) After a brief recall of toxicological data about germanium compounds, the authors relate subacute and subchronic oral toxicities of beta bis carboxyethyl-germanium sesquioxide in rats.
(9) A germanium-gallium generator producing EDTA-free Ga-68 would permit the synthesis of a broad range of Ga-68 radiopharmaceuticals and thus facilitate the widespread application of positron tomography.
(10) Selenium(Se) has been determined in skin by neutron activation analysis applying selective irradiation and cooling time, followed by measurement of the activity on a high resolution germanium lithium (Ge(Li)) detector.
(11) Non-platinum-group metal antitumor agents are represented by inorganic and organometallic compounds which contain either main-group metals such as gallium, germanium, and tin, or transition metals such as titanium, vanadium, iron, copper, and gold.
(12) Germanium can substitute for boron in carrot cell cultures.
(13) In tumor imaging studies, breast tumor masses as small as 4 mm in diameter were clearly localized on a whole body scan using 131I-labeled BLMRL-HMFG-Mc5 antibodies with a High-Purity germanium gamma camera.
(14) A high-purity germanium spectroscopy system and a beam of 120 kV constant potential x-rays were used to determine the linear attenuation coefficient from 18 to 110 keV.
(15) A data-acquisition system designed for x-ray medical imaging utilizes a segmented high-purity germanium (HPGe) detector array with 2-mm wide and 6-mm thick elements.
(16) The spectra of diagnostic x-ray beams were measured with a germanium semiconductor dectector.
(17) Electronically collimated counts were acquired from the objects rotated to 20 or 40 angular positions in front of the germanium detector to simulate a cylindrical scanning system.
(18) Germanium oxide alone did not affect the frequency of sperm-head abnormalities.
(19) The results demonstrate that, within this class of compounds, (1) potent biological activity does not require the presence of germanium in the structure; (2) in vitro cytotoxic activity does not appear to be a direct result of the inhibition of macromolecular synthesis, and (3) macrophage function can be modulated in vitro at non-cytotoxic concentrations.
(20) The presence of aluminium, beryllium, lead, potassium in the examined air don't stand on the way of determining the concentration of germanium.
Metalloid
Definition:
(n.) Formerly, the metallic base of a fixed alkali, or alkaline earth; -- applied by Sir H. Davy to sodium, potassium, and some other metallic substances whose metallic character was supposed to be not well defined.
(n.) Now, one of several elementary substances which in the free state are unlike metals, and whose compounds possess or produce acid, rather than basic, properties; a nonmetal; as, boron, carbon, phosphorus, nitrogen, oxygen, sulphur, chlorine, bromine, etc., are metalloids.
(a.) Having the appearance of a metal.
(a.) Having the properties of a nonmetal; nonmetallic; acid; negative.
Example Sentences:
(1) As with other elements, the interest here is the potential effect of environmental acidification on environmental behavior in ways that are relevant to human exposure to these metalloids.
(2) The effects of the well established carcinogenic metals or metalloids (As, Be, Cr, Ni), hypothetically carcinogenic but well-established cocarcinogenic metals (Cd, Pb, Co) and weak co-carcinogenic metals (Al, Cu, Fe, Zn) and the antagonism between Mg and these metals were studied on the ionic transfer through the isolated human amnion.
(3) New information about the toxic effect of some metals and metalloids and about their kinetics of absorption, distribution and excretion in experimental animals, and particularly in man, is necessary for elaborating suitable biological exposure tests.
(4) Selenium (Se) is a metalloid with chemical properties closed to those of sulfur, but they can not substitute for one another in vivo.
(5) In order to invalidate or confirm the affirmation that non antithyroid sulphide molecules alter the measure of the thyroid fixation rate of iodine 131 we undertook on the rat: on one hand a kinetic study of thyroid fixation of sodium thiosulfate labelled with sulphur 35, which showed a very low captation not exceeding 0,01% of injected radioactivity; on the other hand the study of the effects of some sulphide molecules on thyroid fixation of iodine 131 in the rat: sodium thiosulfate, association of sodium thiosulfate + metalloidal sulphur + methionine, carbutamide and dimethylsulfoxyde in various kinds of dose administration and periods.
(6) Main group metals and metalloids were surveyed for the identification of species that can either donate or accept methyl groups.
(7) Diethyl maleate, indocyanine green and sulfobromophthalein (BSP), which decreased biliary excretion of GSH, significantly diminished excretion of antimony and bismuth into bile indicating that hepatobiliary transport of these metalloids is GSH-dependent.
(8) In recent years, however, it has become clear that several metals and metalloids undergo transformations in mammalian tissues and that metabolism may have important implications in clinical pharmacology, toxicology, and environmental health.
(9) Proportionally to their biliary excretion rates, these metalloids generate increased biliary excretion of GSH probably because they are transported from liver to bile as unstable GSH complexes.
(10) The potential impact of acidic deposition on As and Se in soils cannot readily be assessed with respect to human exposure, but it would appear that the behavior of these metalloids in poorly buffered, poorly immobilizing soils, e.g., sandy soils of low metal hydrous oxide content, would be most affected.
(11) Biological monitoring of exposure to metals and metalloids involves not only determination of these elements in selected body fluids and tissues but, in some cases, also determination of a certain biochemical indicator which signalises the presence of the monitored element in the organism.
(12) Methylcobalamin (methyl-B12) has been implicated in the biomethylation of the heavy metals (mercury, tin, platinum, gold, and thallium) as well as the metalloids (arsenic, selenium, tellurium and sulfur).
(13) Details of the kinetics and mechanisms for biomethylation of arsenic are presented, with special emphasis on synergistic reactions between metal and metalloids in different oxidation states.
(14) The exchange rates for metals and metalloids between sediments, soils, water and aquatic biota are discussed in terms of normal and acidified ecosystems.
(15) The occupational history highlighted heavy exposure to inhalation of ash derived from mineral oil combustion and containing several elements, metals and metalloids, including vanadium and nickel.
(16) Available information on acid precipitation and the environmental behavior of these metalloids do, however, permit some preliminary conclusions to be drawn.
(17) Over the past 15 years, these methods have led to the establishment of causal factors in metal- and metalloid-induced toxicity.
(18) The present studies in rats aimed to determine whether antimony and bismuth, other metalloids in group Va of the periodic table, also possess similar properties.
(19) The abnormal life--potentially the death--of the cell can be restored by a metalloid--lithium--which is nearly as common as sodium in the mineral world.
(20) In this report we present details of the mechanisms for biological methylation of certain metals and metalloids with special emphasis on those elements that are widely dispersed in the biosphere.