What's the difference between isomeric and xylene?

Isomeric


Definition:

  • (a.) Having the same percentage composition; -- said of two or more different substances which contain the same ingredients in the same proportions by weight, often used with with. Specif.: (a) Polymeric; i. e., having the same elements united in the same proportion by weight, but with different molecular weights; as, acetylene and benzine are isomeric (polymeric) with each other in this sense. See Polymeric. (b) Metameric; i. e., having the same elements united in the same proportions by weight, and with the same molecular weight, but which a different structure or arrangement of the ultimate parts; as, ethyl alcohol and methyl ether are isomeric (metameric) with each other in this sense. See Metameric.

Example Sentences:

  • (1) Structure assignment of the isomeric immonium ions 5 and 6, generated via FAB from N-isobutyl glycine and N-methyl valine, can be achieved by their collision induced dissociation characteristics.
  • (2) This is interpreted to mean that the release of fructose from the central complex is faster than the isomerization of the E-NADH complex.
  • (3) The optical and oxygen binding properties of the reconstituted myoglobins containing two isomeric monoformyl-monovinylhemins were found to be different.
  • (4) Line broadening detected in several of the high-field nuclear magnetic resonance spectra was attributed to cis-trans isomerization.
  • (5) Two new isomeric delta-lactones 2 and 3 have been isolated from the marine fungus Helicascus kanaloanus (ATCC 18591).
  • (6) Two isomeric hydrolysis products of this compound with only three 3(R)-hydroxymyristic acid moieties attached to the disaccharide-1-phosphate were also identified.
  • (7) Studies on the metabolism of nicotine by rabbit liver microsomal fractions in the presence of 0.01 M sodium cyanide have led to the characterization of two isomeric cyanonicotine compounds.
  • (8) Kinetic methods are outlined for the distinction between two pathways of substrate binding, which include an isomerization either of the free enzyme or of the enzyme-substrate complex.
  • (9) In the case of H101S, a mutant protein with measurable isomerizing activity, substrate binding with novel fluorescent properties was observed, possibly the bound pyranose form of xylose under steady-state conditions.
  • (10) There were consistent isomeric preferences for the R(-) configuration of both DA analogs in stimulating adenylate cyclase (D-1 sites) and in competing for high affinity binding of 3H-spiroperidol (D-2 sites) and of 3H-ADTN (DA agonist binding sites) in striatal tissue, with lesser isomeric differences in the limbic tissue.
  • (11) Oligosaccharides 3 and 4 and oligosaccharides 5 and 6 were isolated as unresolved isomeric mixtures in fractions B3a and B4a, respectively.
  • (12) Subsequent fractionation of the original compound into its two isomeric forms resulted in the identification of the isomer primarily responsible for this convulsive activity.
  • (13) However, the 1500 K simulation produced higher energy structures, even after minimization; in addition, this highest temperature run had many cis-trans peptide isomerizations.
  • (14) From model compound data, it is shown that the expected rate for isomerism is in satisfactory agreement with the rates actually observed for protein folding.
  • (15) Re-analysis of PCP and PCP-Na samples with high PCDD contents on a high-resolution glass capillary column showed the presence of 3 hexa- and the 2 heptachlorodibenzo-p-dioxins with nearly constant isomeric ratios.
  • (16) Such a genomic structure does not appear to have been reported amongst the herpesviruses--all the genomes that do not isomerize either have repeat structures only at the termini, or if present internally, have only direct repeats.
  • (17) The isomeric N,N-dimethyl-4,5-diphenyl-1H-pyrazole-1-propanamine was completely inactive in the primary antidepressant screens.
  • (18) Correspondingly, in the case of the histidine-peptides examined only mixtures of the cyclic isomeric compounds were isolated and structurally characterized by 1H-NMR analysis.
  • (19) In contrast to the biphasic unfolding of the wild-type nuclease, the unfolding of the mutant is represented by a single-phase reaction, indicating that the biphasic unfolding for the wild-type protein is caused by cis-trans isomerization about the prolyl peptide bond in the native state.
  • (20) In order to prepare a completely light-stable rhodopsin, we have synthesized an analog, II, of 11-cis retinal in which isomerization at the C11-C12 cis-double bond is blocked by formation of a cyclohexene ring from the C10 to C13-methyl.

Xylene


Definition:

  • (n.) Any of a group of three metameric hydrocarbons of the aromatic series, found in coal and wood tar, and so named because found in crude wood spirit. They are colorless, oily, inflammable liquids, C6H4.(CH3)2, being dimethyl benzenes, and are called respectively orthoxylene, metaxylene, and paraxylene. Called also xylol.

Example Sentences:

  • (1) Furthermore, toluene undergoes methyl-substitution in preparations of human bone marrow incubated with S-adenosyl-L-methionine to yield o-xylene, m-xylene, and p-xylene.
  • (2) We have investigated the whole-body dermal penetration of styrene, xylene, toluene, perchloroethylene, benzene, halothane, hexane, and isoflurane in rats and compared the permeability constants with available human studies on vapor penetration.
  • (3) As organic solvents, 1,1,1-trichloroethane (1,1,1-TCE), trichloroethylene, tetrachloroethylene, toluene, m-xylene and trichloro-trifluoroethane (FC-113) were used in this study.
  • (4) In experiments in vitro, neither benzene, toluene nor xylene changed the number of sister-chromatid exchanges (SCEs) or the number of chromosomal aberrations in human lymphocytes.
  • (5) The m-xylene-adapted microorganisms in the aquifer column degraded toluene, benzaldehyde, benzoate, m-toluylaldehyde, m-toluate, m-cresol, p-cresol, and p-hydroxybenzoate but were unable to metabolize benzene, naphthalene, methylcyclohexane, and 1,3-dimethylcyclohexane.
  • (6) A 27-year-old male committed suicide by ingestion of a large quantity of xylene.
  • (7) Blot and give 2 fast changes in absolute ethanol with agitation before transferring to xylene.
  • (8) Time-course experiments did not indicate any delay in the peak micronucleus response to benzene caused by either pyridine or xylene.
  • (9) Six scenarios for human exposure were examined, based primarily on measured air and water concentrations of total hydrocarbons, benzene, xylenes, and toluene.
  • (10) Perhaps alpha activation is indicative of stimulating and excitatory effects induced by m-xylene exposure, which has been noted heretofore in the absorption phase of alcohol intake.
  • (11) During the first part, the same test group was exposed to m-xylene for a period of 4 hours, whereas during the second part, the group was exposed to m-xylene in combination with other solvents.
  • (12) Finally, the sections were cleared in xylene and mounted in D.P.X.
  • (13) The 24-h excretion of the urine metabolites of m-xylene was decreased by 22-24% in mixed exposures: the excretion of methylhippuric acid was decreased (29%), but that of 2,4-dimethylphenol increased (9-35%).
  • (14) By the combined use of gas chromatography and mass spectrometry the methyl esters of hippuric acid and m-methylhippuric acid were identified in the urine of a volunteer who had been exposed to toluene and m-xylene vapours.
  • (15) The ability of the recombinant to utilize 3-chlorobenzoate, chlorobenzene, and 1,4-dichlorobenzene as well as its loss of utilization of xylenes and methylbenzoates appears to be associated with the transfer and integration of chromosomal DNA from P. alcaligenes into a Tol-like plasmid of P. putida R5-3.
  • (16) After repeated inhalation exposures the excretion of xylene metabolites in urine was consistently higher, whereas the concentrations of xylene in fat (but not the concentration of MEK) were lower than after a single treatment, conceivably due to accelerated metabolic clearance of xylene.
  • (17) Using various fixation procedures (formalin, paraformaldehyde, B-5, Zamboni and AMeX) we found that fixation in cold acetone (-20 degrees C) overnight followed by 2x15 min fixation in acetone at +4 degrees c and at room temperature, cleared in methyl benzoate and xylene (AMeX procedure) gives reproducible nuclear staining when a variety of normal and tumor tissues are treated with an anti c-myc protein antibody.
  • (18) Transfer slide to 0.5% n-butylamine in xylene for a few seconds until the section is blue, then, after 2 changes of xylene, mount in DPX.
  • (19) The effect of alimentary deficiency, ethanol intake and exposure to xylene on the coronary microvessels and heart weight were investigated in rats.
  • (20) Treatment of P. putida BG1 with nitrosoguanidine led to the isolation of a mutant strain which, when grown with fructose, oxidized both p-xylene and p-toluate to (-)-cis-1,2-dihydroxy-4-methylcyclohexa-3,5-diene-1-carboxylic acid (cis-p-toluate diol).