What's the difference between isomer and polymer?

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.

Polymer


Definition:

  • (n.) Any one of two or more substances related to each other by polymerism; specifically, a substance produced from another substance by chemical polymerization.

Example Sentences:

  • (1) Five days later, the animals were randomly assigned to one of four treatment groups: Group 1 received intracranial implantation of controlled-release polymers containing dexamethasone; Group 2 received intraperitoneal implantation of controlled-release polymers containing dexamethasone; Group 3 received serial intraperitoneal injections of dexamethasone; and Group 4 received sham treatment.
  • (2) In spite of important differences in size, chemical composition, polymer density, and configuration, biological macromolecules indeed manifest some of the essential physical-chemical properties of gels.
  • (3) The acetonitrile extract is concentrated and analyzed by HPLC, using a new polymer-based column, and detected by UV spectroscopy at 270 nm.
  • (4) These results suggest that glomerular IgA are IgA polymers and decreased hepatic clearance of hepatic IgA polymers may be responsible for the glomerular deposition of IgA.
  • (5) A method for the introduction of side chains containing isonitrile (isocyanide, functional group) on the backbone of polysaccharides and other hydroxylic polymers was developed.
  • (6) He knows polymer notes from travels in Australia, where they were first introduced in 1988, and he wants Britain to "move with the times" too.
  • (7) Poly(ortho ester) bioerodible polymers are suitable materials for the topical administration of a wide variety of therapeutic agents; varying the nature and amounts of excipients physically incorporated into the polymer will vary the erosion rates from a few hours to many months.
  • (8) By performing countercurrent distribution in the presence of a polymer-ligand, the protein that binds the polymer-ligand can be separated from a heterogenous mixture.
  • (9) Pulse labeling of the polymer with [2-3H]adenosine was also maximal at the same time points.
  • (10) Charged polymers, known to alter cell surface characteristics, reversibly inhibit the intercellular communication required in kidney tubule induction.
  • (11) A novel type of ion exchanger was prepared by multipoint covalent binding of polystyrene chains onto the surface of porous silica followed by polymer-analogous modification of the bonded layer.
  • (12) Another 52 received a 100-g (nonfasting) glucose polymer screening test followed by a 100-g glucose polymer tolerance test.
  • (13) The important role of the exocellular polymers for the structure, size and density of flocs can be well illustrated.
  • (14) A small number of children with protracted diarrhoea, who have severe mucosal injury may not be able to handle even starch and may require diets based on short chain glucose polymers.
  • (15) Rather, assembly of sIgM into polymers and their subsequent secretion are prevented in B lymphocytes by preceding targeting of monomeric sIgM to degradation.
  • (16) The neutral polymer was devoid of type 6 activity although it was serologically active.
  • (17) The tissue reaction was more severe for polymers having a higher rate of degradation.
  • (18) Control experiments with other constructs (e.g., allopurinol riboside linked to the mannose-free polymer) confirmed that the enhancement of activity was indeed achieved by means of the mannose homing device.
  • (19) Of the tested polymers, only polyvinyl methylacetamide and dextran inhibit a decrease in the level of mitochondrial enzyme activity which develops with administration of endotoxin.
  • (20) At different degrees of DNA damage, the average length of the poly-ADP-ribose chain did not practically alter, thus suggesting the increase in the number of polymer binding sites in the histones.