What's the difference between isomer and radioactive?

Isomer


Definition:

  • (n.) A body or compound which is isomeric with another body or compound; a member of an isomeric series.

Example Sentences:

  • (1) An unsaturated fatty acid auxotroph of Escherichia coli was grown with a series of cis-octadecenoate isomers in which the location of the double bond varied from positions 3 to 17.
  • (2) Fluorination with [18F]acetylhypofluorite yields 6-[18F]fluoro-L-dopa with 95% radiochemical purity; fluorination of the same substrate with [18F]F2 yields a mixture of all three structural isomers in a ratio of 70:16:14 for 6-, 5-, and 2-fluoro compounds.
  • (3) The cis isomer was retained longer in liver, particularly in mitochondria, but had low retention in that portion of the endoplasmic reticulum isolated as the rough membrane fraction.
  • (4) The purity and configuration of each isomer of the free acid and N-chloroacetylated derivative were ascertained by: (a) paper chromatography in five solvent systems, (b) elemental analysis, (c) Van Slyke nitrous acid determination of alpha-carbonyl carbon, and (d) Van Slyke ninhydrin determination of alpha-carbonyl carbon, and (e) optical rotation.
  • (5) The stronger negative potentials may weaken electrostatic receptor interactions and, thereby, cause the trans(E)-isomers to be less active than cis(Z)-isomers.
  • (6) The identity of each of the three forms was determined by carboxymethylation of the free cysteines in each isomer with [3H]iodoacetic acid followed by determination of the labelled cysteines by tryptic peptide mapping.
  • (7) In contrast to the enantiomeric discrimination observed with racemic amine, the individual isomers were metabolized at approximately the same rate.
  • (8) To further assess different binding behavior of these two isomers, association rate was measured.
  • (9) None of the 3 beta- or 5 beta-isomers had any effect.
  • (10) Isomers and epimers of glucose influence insulin and cAMP in a parallel fashion as do sulfonylurea compounds (tolbutamide and glibenclamide).
  • (11) Bioaccumulation experiments were performed on the hexachlorocyclohexane isomers alpha-HCH, beta-HCH, gamma-HCH and delta-HCH, testing them simultaneously.
  • (12) Although serum total LDH activity was not altered, the LD5 isoenzyme was proportionately higher in the HCH isomers treated animals.
  • (13) Racemic verapamil and the L- and D-isomer increased cellular vincristine accumulation to the same extent.
  • (14) The hypothesis that opiate agonism requires an N substituent in the axial position does not appear to be consistent with the increased potency of beta isomers in which axial N substituents are thermodynamically more unstable.
  • (15) In the case of adducts with the diol-epoxides of benzo[c]phenanthrene, the energetically most favored structures are isomers with significant biological activity.
  • (16) Liver regeneration was stimulated in male rats with two-thirds of the liver removed by feeding a basal diet supplemented with acetaminophen (0.35-1.5%; weight basis), 2-acetamidophenol (1.0%) and acetophenetidin (1.0%) over a period of 10 days po, but was in the control range with the m-isomer, 3-acetamidophenol (1.0%), N-butyryl-p-aminophenol (1.0%), o-, m- and p-aminophenols (0.50%) and 4-acetamidothiophenol.
  • (17) However, exposure of the cells to either of the two isomers of azoxy-procarbazine led to significant DNA damage and cytotoxicity.
  • (18) 1"-Oxobufuralol (3) was reduced with a complex of (2S)-(-)-2-amino-3-methyl-1,1-diphenylbutan-1-ol and borane, yielding 2, which had a 95:5 ratio of the possible 1"R and 1"S isomers as determined by HPLC.
  • (19) As the two signals had the same intensities, it was suggested that equivalent amounts of cis and trans isomers of the alkenylmether were formed.
  • (20) The most important recent work has concerned the different anticoagulant potencies and metabolic pathways of the optical isomers of some of these drugs.

Radioactive


Definition:

Example Sentences:

  • (1) Following central retinal artery ligation, infarction of the retinal ganglion cells was reflected by a 97 per cent reduction in the radioactively labeled protein within the optic nerve.
  • (2) Because cystine in medium was converted rapidly to cysteine and cysteinyl-NAC in the presence of NAC and given that cysteine has a higher affinity for uptake by EC than cystine, we conclude that the enhanced uptake of radioactivity was in the form of cysteine and at least part of the stimulatory effect of NAC on EC glutathione was due to a formation of cysteine by a mixed disulfide reaction of NAC with cystine similar to that previously reported for Chinese hamster ovarian cells (R. D. Issels et al.
  • (3) Estimations of the degree of incorporation of 14C from the radioactive labeled carbohydrate into the glycerol and fatty acid moieties were carried out.
  • (4) Most of the radioactivity in spleen cells from these rats were associated with antigen-reactive cells which formed rosettes specifically with HO erythrocytes.
  • (5) Q In radioactive decay, different materials decay at different rates, giving different half lives.
  • (6) Blood flow was measured in leg and torso skin of conscious or anesthetized sheep by using 15-micron radioactive microspheres (Qm) and the 133Xe washout method (QXe).
  • (7) During the digestion of these radiolabeled bacteria, murine bone marrow macrophages produced low-molecular-weight substances that coeluted chromatographically with the radioactive cell wall marker.
  • (8) In oleate-labeled particles, besides phosphatidic acid the product of PLD action radioactivity was also detected in diglyceride as a result of resident phosphatidate phosphohydrolase, which hydrolyzed the phosphatidic acid.
  • (9) Control incubations revealed an inherent difference between the two substrates; gram-positive supernatants consistently contained 5% radioactivity, whereas even at 0 h, those from the gram-negative mutant released 22%.
  • (10) The remainder of the radioactivity appeared chromatographically just prior to the bisantrene peak, indicating that compounds more polar than the parent were present as transformation products.
  • (11) High radioactivities were observed in the digestive organs, mesenteric lymphnodes, liver, pancreas, urinary bladder, fat tissue, kidney and spleen after oral administration to rats.
  • (12) When labelled long-chain fatty acids or glycerol were infused into the lactating goat, there was extensive transfer of radioactivity into milk in spite of the absence of net uptake of substrate by the mammary gland.
  • (13) Treatment with trypsin gave essentially one radioactive peptide, the active site peptide, of approximately 2300 molecular weight.
  • (14) Radioactivity attained in different tissues at different times after a single intraperitoneal injection of 3H-gentamicin into male rats was determined using scintillation counting.
  • (15) The present in vitro studies show that it is found as beta-endorphin in bovine pituitary slices incubated with radioactive amino acid precursor [35S]methionine.
  • (16) Bacterial adherence to vascular sutures was evaluated in vitro using radioactively labeled Staphylococcus aureus.
  • (17) Under the same conditions, no radioactive estrogen could be identified in adrenal and placental incubations.
  • (18) Four hours after injection radioactivity was identified in the spleen, liver, and bone marrow.
  • (19) Chromatographic analysis of this radioactivity reveals that the octadecapeptide gives rise to much higher tissue levels of intact peptide and we believe that this acts as a depot and gives rise to the sustained blood concentrations and prolonged biological effects observed with this peptide.
  • (20) 25% of the incorporated radioactivity in protoplast lysates and approx.