What's the difference between hexavalent and valence?

Hexavalent


Definition:

  • (p. pr.) Having a valence of six; -- said of hexads.

Example Sentences:

  • (1) The contents of hexavalent chromium, Cr(VI), in grinding dust were undetectable.
  • (2) The mutagenic potency of the hexavalent metal was not enhanced by adding the microsomal fraction of rat hepatocytes, induced either with sodium barbital or with Aroclor 1254.
  • (3) These results suggest that SCE analysis in human lymphocytes is not a good indicator of possible mutagenic effects of exposure to hexavalent Cr.
  • (4) Both NAC and AR also stimulated other detoxifying mechanisms, such as those related to GSH S-transferase activity and to the NADPH-dependent reduction of hexavalent chromium.
  • (5) The theoretically increased lifetime carcinogenic risk from a continuous lifetime exposure to hexavalent chromium fell within the range 12-146 cancer cases per nanogram hexavalent chromium per cubic meter of air per million people exposed, depending on the potency estimate used.
  • (6) The effect of vitamin E was demonstrated only in an increase of the ratio of NCE to PCE, i.e., in a decrease of the cytotoxic but not the mutagenic effects of hexavalent chromium.
  • (7) Low-level exposure to hexavalent chromium associated with TIG stainless steel and mild steel welding do not appear to be a major hazard for human spermatogenesis.
  • (8) The reduction of hexavalent chromium (Cr(VI] by rat liver microsomes was studied.
  • (9) In order to study the difference of uptake and distribution between hexavalent (Cr6+) and trivalent (Cr3+) chromium in isolated rat hepatocytes, the cells were incubated with Cr6+ or Cr3+ (1 mM Cr) at 37 degrees C for up to 60 min.
  • (10) The development of spraying of sludges and composts will increase the quantity and efficiency of chromium in vegetals, because of various factors: the wastes of many industries: chromium plating plants, tanneries, painting and dyeing industries throw out hexavalent chromium; if the sewage sludges are purified by an irradiation treatment, it will tend to oxidize the whole chromium in hexavalent forms; at last, the presence of sewage sludges in the arable soil favours the assimilation of chromium by inhibiting that of iron (Figure 1).
  • (11) administration of high doses of hexavalent chromium to rats.
  • (12) The allergens which are responsible for about 50% of our cases are: turpentine, nickel, hexavalent chromium and mercuri-organic compounds.
  • (13) The chemical speciation of the chromium in Whetlerite was found to be: from 0.6 to 1.3% insoluble trivalent chromium; from 1.0 to 1.3% insoluble hexavalent chromium; and from 0.7 to 0.9% soluble hexavalent chromium.
  • (14) Addition of iron sulfate to cement means transformation of water-soluble hexavalent chromium into nonwater-soluble trivalent chromium.
  • (15) The distinctive sensitivity of the four Salmonella strains tested (TA1535, TA1537, TA98, and TA100) suggested that hexavalent chromium directly interacts with bacterial deoxyribonucleic acid by causing both frameshift mutations and basepair substitutions.
  • (16) Chronic exposure to low concentrations or brief exposures to high concentrations of hexavalent chromium (K2CrO4) transformed a rat liver epithelial cell line as assessed by anchorage-independent growth.
  • (17) Chromate (hexavalent chromium) salts of both high and medium water solubility were active in producing all three classes of response, whereas an insoluble chromate salt and a soluble chromic (trivalent chromium) salt were inactive.
  • (18) Some bacteria are able to reduce hexavalent chromium to trivalent chromium which is much less toxic.
  • (19) These results demonstrate that the epicutaneous application of chromate resulted in a characteristic intraepidermal distribution which may be related to the epidermal conversion of the hexavalent chromate to the immunogenic trivalent form.
  • (20) It is therefore concluded that direct interaction of hexavalent CrO3 with plasma membrane of lymphocytes results in concentration-dependent cytotoxicity and the inhibition of [3H]-TdR incorporation, but it does not induce blastogenesis.

Valence


Definition:

  • (n.) The degree of combining power of an atom (or radical) as shown by the number of atoms of hydrogen (or of other monads, as chlorine, sodium, etc.) with which it will combine, or for which it can be substituted, or with which it can be compared; thus, an atom of hydrogen is a monad, and has a valence of one; the atoms of oxygen, nitrogen, and carbon are respectively dyads, triads, and tetrads, and have a valence respectively of two, three, and four.

Example Sentences:

  • (1) The mixed-valence-state cytochrome oxidase mixed with O2 at -24 degrees C and flash-photolysed at -60 to -100 degrees C reacts with O2 and initially forms an oxy compound (A2) similar to that formed from the fully reduced state (A1).
  • (2) Additional results, together with simulations based on a simple kinetic model, suggest that the reduced apparent valence of the low slope component of the Q-V curve results from gating charge immobilization occurring at holding potential.
  • (3) A related explanation is that the 609 nm absorbance involves a charge-transfer interaction of both iron and copper as a mixed-valence binuclear complex, Cua3, having properties of a non-blue copper.
  • (4) RBDs were significantly more impaired than LBDs or NCs on category and valence accuracy, while LBDs posed expressions with significantly more intensity than RBDs or NCs.
  • (5) The extent of adsorption was affected by the concentration and valency of cations, indicating a charge-dependent process.
  • (6) Use of that principle was demonstrated by fourth grade children who judged that telling the truth, as opposed to lying, was shown by a consistency between the affective valence of the verbal and the nonverbal communications.
  • (7) Research reported here shows that primary and transferred releasing valences are differentially affected by environmental variables.
  • (8) Furthermore, the valences of all ions in solution on both sides of the membrane are taken to be of equal absolute magnitude.
  • (9) Possible valence bond structures for 3-methylpurine residues in DNA are discussed, leading to the suggestion that ionized forms with positively charged amino groups may be the most effective blocks to template activity.
  • (10) A confirmatory factor analysis on these subscales showed that the Affective Valence, Empathic Caring, Self-Sacrifice, and Societies' Duties subscales each reflect a humanitarian concern for children and that the Instrumentality and Authoritarian Attitude subscales tap values involving a moralistic expectation of children.
  • (11) The excitatory potential, the involvement potential, and the hedonic valence of the nonerotic and erotic stimuli were also assessed.
  • (12) A monovalent form of concanavalin A (m-Con A) has been prepared to determine the importance of valence for human lymphocyte surface binding and subsequent lymphocyte stimulation as measured by blast transformation and cytotoxicity.
  • (13) As concerns the valence of the natural focus, the most important was the inundated forest in the Drnholec locality.
  • (14) Examination of the antigen dose-response curves and maximal responses obtained suggests that valency of the antigen may be important both in determining the avidity of interaction between the pCTL and the antigen-bearing structure, and in determining the extent to which localized receptor cross-linking occurs on the cell surface to result in triggering.
  • (15) Therefore, no conclusions about biological valence and tumour localisation could be drawn from the aspect of the cell picture which we observed and from the degree of pleocytosis.
  • (16) During presentation of pictures with negative valence the m. frontalis lateralis and the m. corrugator supercilii revealed enhanced EMG-reactions as compared to the repeated presentation of pictures with positive valence.
  • (17) The degree and the character of these changes depend on cation valency and the initial value of cell EM.
  • (18) Maximum adsorption at 23 degrees C occurred within 2 h. The amounts of DNA which adsorbed to sand increased with the salt concentration (0.1 to 4 M NaCl and 1 mM to 0.2 M MgCl2), salt valency (Na+ less than Mg2+ and Ca2+), and pH (5 to 9).
  • (19) The influence of valence and heavy chain on antibody activity was investigated using transfectoma-derived, class-switched IgG1 and IgM human monoclonal antibodies (MAbs) reactive with the bacterial pathogens Escherichia coli K1 and group B Streptococcus species.
  • (20) The obtained data allows to suggest that one of the possible mechanisms of 6-ONDA neurotoxic action includes the generation of superoxide, whose dismutation to hydrogen peroxide in the presence of transient valency ions gives rise to HO.

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