(n.) One of the Diatomaceae, a family of minute unicellular Algae having a siliceous covering of great delicacy, each individual multiplying by spontaneous division. By some authors diatoms are called Bacillariae, but this word is not in general use.
(n.) A particle or atom endowed with the vital principle.
Example Sentences:
(1) The cytoplasmic and chloroplast ribosomes from the marine diatom Cylindrotheca fusiformis were isolated and characterized.
(2) The concentration of acetate in the interstitial water fell from about 100 microM (immediately after sedimentation of the spring diatom bloom) to a relatively constant value of about 20 microM in late summer, during which acetate utilization appeared to be balanced by production.
(3) The affinity of the diatom for glucose was greater than that shown by the bacterium, but the Km for glucose transport, 1.5x10-5M was too high to allow effective removal of glucose at in situ concentrations.
(4) We have cloned and sequenced a 5200 base restriction fragment and an overlapping 3100 base fragment of the large single copy region of the chloroplast genome of the diatom Odontella sinensis, which hybridized to several ATPase gene probes.
(5) The material consisted of 285 successive drownings, which were subject to autopsy at the Helsinki University Department of Forensic Medicine between 1978 and 1986 and for whom diatom analysis was carried out.
(6) Substituting size-fractionated silica particles for diatoms (the fossilized cell walls of unicellular algae) allowed for the purification of microgram amounts of genomic DNA, plasmid DNA, and rRNA from cell-rich sources, as exemplified for pathogenic gram-negative bacteria.
(7) In diatom and yeast spindles, elongation of the spindle in anaphase (anaphase B) may be explained by microtubule assembly at polar microtubule ends in the spindle mid-zone and sliding of the antiparallel microtubules from the opposite poles.
(8) Cells of the diatom Cyclotella meneghiniana were exposed in a closed system to 0.245 ppm 1,2,3-trichlorobenzene.
(9) Cells of the diatom Cyclotella meneghiniana were exposed in a closed system to 0.245 ppm 1,3,5-trichlorobenzene.
(10) Extracted diatom DNA separates into two bands in CsCl-Hoechst 33258 dye gradients.
(11) Quinones constituting the electron transfer systems in a marine unicellular diatom, Phaeodactylum tricornutum, were isolated and identified chromatographically.
(12) A new sulfonolipid has been isolated from a non-photosynthetic diatom, Nitzschia alba, by thin-layer and column chromatography on silicic acid, and characterized by 35S-labeling, mobility on thin-layer chromatography, infrared and NMR spectroscopy and products of hydrolysis, as a ceramide sulfonic acid (N-acyl sphingosine-1-sulfonic acid).
(13) Among eukaryotes, red algae emerged first; and, later, thraustochytrids (a Proctista group), ascomycetes (yeast), green plants (green algae and land plants), "yellow algae" (brown algae, diatoms, and chrysophyte algae), basidiomycetes (mushrooms and rusts), slime- and water molds, various protozoans, and animals emerged, approximately in that order.
(14) The spindle of the colonial diatom Fragilaria contains two distinct sets of spindle microtubules (MTs): (a) MTs comprising the central spindle, which is composed of two half-spindles interdigitated to form a region of "overlap"; (b) MTs which radiate laterally from the poles.
(15) The conformation of berchemolide was calculated by MNDO (modified neglect of diatomic overlap).
(16) Usually algal populations change from a dominance of diatoms and green algae to dominance by blue-green algae.
(17) But it seems to have stuck.” The following year, Crutzen and Eugene Stoermer – an American diatom specialist who had been using the term informally since the 1980s – jointly published an article proposing that the Anthropocene should be considered a new Earth epoch, on the grounds that “mankind will remain a major geological force for many millennia, maybe millions of years to come”.
(18) The particles are surfaces for the attachment of diatoms and hydroids.
(19) Mitotic spindles isolated from the diatom Stephanopyxis turris consist of two half-spindles of closely interdigitating microtubules that slide relative to one another in the presence of ATP, reinitiating spindle elongation (anaphase B) in vitro.
(20) We describe here a simple procedure for isolating diatom spindles which are capable of anaphase spindle elongation in vitro.
Kieselguhr
Definition:
(n.) Siliceous earth; specifically, porous infusorial earth, used as an absorbent of nitroglycerin in the manufacture of dynamite.
Example Sentences:
(1) Alumina, Kieselguhr and various grades of silica gel have been tested as supports.
(2) Mouse L-cell mitochondrial rRNA was eluted after cytoplasmic rRNA on a column of methylated albumin-kieselguhr.
(3) The method consists of trapping chlordiazepoxide in sulfuric acid in kieselguhr, eluting the impurity with ether, and quantitating by UV spectrophotometry in absolute alcohol at 312 nm.
(4) This labeled material was shown to be separable from nucleic acids, could be eluted from a methylated albumin-kieselguhr column at 0.5 m NaCl, was of high molecular weight, and had several characteristics in common with polyphosphate.
(5) This is demonstrated by fractionation, on methylated albumin-kieselguhr columns, of a mixture of nucleic acids from vegetative and induced buds, one being labeled with uridine-H(3) and the other with uridine-2-C(14).
(6) With methylated albumin-kieselguhr fractionated 3H-HeLa DNA as a source of native or single-strand DNA antigen in a modified Farr assay, an increased level of antibody to native DNA was associated with active systemic lupus erythematosus, particularly active nephritis.
(7) Tyrosyl-, histidyl-, lysyl-, and phenylalanyl-tRNA's from 3 tumors (DBAH, DBAH, and DBA), differing in growth rates and from host mammary glands and liver, were compared by means of methylated albumin kieselguhr (MAK) column and by reverse-phase-5 chromatography.
(8) Stomach and intestine contents and blood samples from guinea-pigs were cleaned up by use of a kieselguhr column followed by heptane-water partition.
(9) The resolution of triglyceride mixtures on a Kieselguhr G layer silanized with dimethyldichlorosilane and the mobile phase acetone-acetonitrile-water under different chromatographic conditions has been investigated.
(10) From the purified neurotoxin isolated by kieselguhr and cellulose chromatography we calibrated analytic columns for b4-2 analysis.
(11) Demand for kieselguhr has increased and new factories are to be established which may result in new cases of silicosis.
(12) In Sweden six cases of silicosis caused by exposure to kieselguhr have been reported to the Worker's Protection Board.
(13) DNA preparations from seven bacterial species and from the E. coli phage T4 can, after denaturation with alkali, be separated chromatographically into two distinct components (L and H) through intermittent gradient elution from methylated albumin kieselguhr columns.
(14) Minor components of RNA (detected by pulse-labelling and chromatography on methylated albumin-kieselguhr) and rapidly labelled components of DNA containing single-stranded regions are also precipitated.
(15) Chromatography on methylated albumin-kieselguhr columns failed to separate 40S RNA from 26S RNA.
(16) The method involves extraction with aqueous methanol followed by a two-stage clean-up procedure utilizing a commercial kieselguhr column and a silica gel cartridge.
(17) The bacteriophage øX-174 replicative form of DNA exists in two configurations, as judged by electron microscopy and sucrose density gradient sedimentation, and on methylated albumin-coated kieselguhr column chromatography.
(18) The only way to prepare high molecular weight rapidly labelled RNA and polysomes was to grind freeze-dried cells together with kieselguhr with a mortar and pestle.
(19) The effect of hormones on (32)P incorporation into various RNA fractions in germinating pear embryos was studied by fractionation on methylated albumin-kieselguhr columns.
(20) Control of ribosomal RNA and transfer RNA syntheses was examined by chromatographing cell extracts on methylated albumin kieselguhr columns.