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  • Bud pollination  (2)
  • Cell & Developmental Biology  (2)
  • conductivity  (2)
  • dissociation constant  (2)
  • electrolytes  (2)
  • ionization  (2)
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Material
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Keywords
  • 1
    Electronic Resource
    Electronic Resource
    Conductivity and ion pairing of hydrogen chloride inN-methylpropionamide at 25°C (1976)
    Springer
    Journal of solution chemistry 5 (1976), S. 765-771 
    Details
    ISSN: 1572-8927
    Keywords: Association constant ; conductivity ; hydrogen chloride ; ion association ; ionic conductivity ; N-methylpropionamide ; nonaqueous solvent
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The electrical conductivity of solutions of HCl inN-methylpropionamide (NMP) has been measured at 25°C for concentrations of HCl ranging from 0.0012 to 0.07 mole-liter−1. The results, combined with other data recently reported, were analyzed by means of the conductivity equation of Pitts. Some evidence for association was found in spite of the very large relative permittivity of the solvent medium (ε=176 at 25°C). The limiting molar conductivity for HCl is 10.949 S-cm2-mole−1. The limiting ionic conductivities in NMP are estimated to be 5.548 S-cm2-mole−1 for chloride ion and 5.401 S-cm2-mole−1 for hydrogen ion.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00651486
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  • 2
    Electronic Resource
    Electronic Resource
    Dissociation constant of acetic acid in N-methylpropionamide from 5 to 55°C and related thermodynamic quantities (1972)
    Springer
    Journal of solution chemistry 1 (1972), S. 507-516 
    Details
    ISSN: 1572-8927
    Keywords: Acetic acid ; dissociation constant ; N methylpropionamide ; nonaqueous solvents ; solute-solvent interactions ; weak acids
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The dissociation constant of acetic acid in N-methylpropionamide (NMP) has been determined at 11 temperatures from 5 to 55°C by measurement of the electromotive force of cells without liquid junction containing hydrogen gas electrodes and silver-silver chloride electrodes. The pK at 25°C was found to be 7.995 (molal scale) as compared with 4.756 in water; thus, acetic acid is much weaker in NMP than in water despite the higher dielectric constant of the nonaqueous solvent (176 as compared with 78.3 at 25°C). The standard changes of enthalpy and entropy for the dissociation of acetic acid were calculated from the temperature coefficient of pK, and thermodynamic functions for the transfer dissociation process were obtained. The weakness of acetic acid in NMP is discussed in terms of electrostatic effects and solute-solvent interactions.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00651727
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  • 3
    Electronic Resource
    Electronic Resource
    Dissociation constant of protonated tris(hydroxymethyl)aminomethane in N-methylpropionamide and related thermodynamic quantities from 10 to 55°C (1973)
    Springer
    Journal of solution chemistry 2 (1973), S. 405-415 
    Details
    ISSN: 1572-8927
    Keywords: Acidic dissociation ; dissociation constant ; emf measurements ; ionization processes ; N-methylpropionamide ; solvation ; tris-(hydroxymethyl)aminomethane
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The dissociation constant of protonated tris(hydroxymethyl)aminomethane (tris·H+) in the solvent N-methylpropionamide (NMP) has been determined at intervals of 5°C from 10 to 55°C by measurement of the emf of cells without liquid junction using hydrogen and silver-silver chloride electrodes. At 25°C, pK a was found to be 8.831, as compared with 8.075 in water. The standard changes in Gibbs energy, enthalpy, and entropy for the dissociation process have been evaluated from the dissociation constant and its change with temperature. By comparison with similar data for the dissociation of tris·H+ in water, thermodynamic functions for the transfer from water to NMP have been derived. The dissociation process is isoelectric, and the solvent dielectric constant is high (ε=176 at 25°C). Consequently, electrostatic charging effects are expected to be minimal, and the change in dissociation constant depends primarily on solute-solvent interactions. The results, combined with transfer energies for HCl, tris, and tris·HCl from emf and solubility measurements, demonstrate that the decreased acidic strength of tri·H+ in NMP is attributable in large part to the fact that NMP is less effective than water in stabilizing tris and its salts.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00713253
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  • 4
    Electronic Resource
    Electronic Resource
    Activity coefficient of hydrochloric acid in aqueous solutions of sodium chloride (1977)
    Springer
    Journal of solution chemistry 6 (1977), S. 385-392 
    Details
    ISSN: 1572-8927
    Keywords: Activity coefficient ; electrolytes ; mixed ; Harned coefficients ; hydrochloric acid ; mixed electrolyte solutions ; sodium chloride
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Electromotive-force measurements of the cell $$Pt;H_2 \left( {g,1{\text{ }}atm} \right)|HCl\left( {{\text{m}}_A } \right),NaCl\left( {{\text{m}}_B } \right)|AgCl;Ag$$ have been made at temperatures between 5 and 45°C at values ofm A+m B of 0.1, 0.3809, 0.6729, and 0.8720 mole-kg−1. The activity coefficients of HCl in HCl/NaCl mixtures and the Harned coefficients α12 have been obtained. The change of α12 with total molality is consistent with the existence of binary interactions between H+ and Na+ ions. The linear variation of the relative partial molal heat content with the fraction of NaCl in the mixture suggests that an analog of the Harned rule exists for this thermodynamic quantity.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00645511
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  • 5
    Electronic Resource
    Electronic Resource
    Conductance of tetraalkylammonium salts in propylene carbonate at 25°C (1978)
    Springer
    Journal of solution chemistry 7 (1978), S. 631-638 
    Details
    ISSN: 1572-8927
    Keywords: Association of ions ; conductivity ; dissociation ; ionization ; ion pairing ; nonaqueous solvents ; propylene carbonate ; solute-solvent effects
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Conductance measurements of 12 quaternary ammonium salts in propylene carbonate (PC) have been made at 25°C. The cations were either tetramethylammonium, tetraethylammonium, or tetra-n-butylammonium, and the concentrations of salt varied from about 2×10−4 to 5×10−3 M. The data were analyzed by the equation of Pitts. The results showed that the benzoate, nitrobenzoate, and pentachlorophenolate salts are completely dissociated. The nitrophenolate, chlorophenolate, methylsulfonate, and nitrate salts are only slightly associated (K A from 2.5 to 6.5), while the acetate, phenylacetate, and nitrophenolate salts display somewhat more extensive association, with ionpair association constants from 17 to 45. Limiting molar conductances for the anions were derived. The factors affecting ionic mobilities in this dipolar aprotic solvent are discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00646040
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  • 6
    Electronic Resource
    Electronic Resource
    The temperature variation of the Harned coefficient in the system HCl−NaCl (1980)
    Springer
    Journal of solution chemistry 9 (1980), S. 449-454 
    Details
    ISSN: 1572-8927
    Keywords: Activity coefficient ; electrolytes ; mixed ; Harned coefficient ; hydrochloric acid ; mixed electrolyte solutions ; sodium chloride
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The Harned coefficient measures the effect of an added electrolyte on the activity coefficient of another electrolyte. It is composite, depending partly on properties of solutions containing only one electrolyte and partly on the magnitude of a coefficient characteristic of interaction between two like charged ions in the mixed electrolyte solution. From the meager data available, the latter coefficient depends little upon temperature. The consequences of assuming temperature independence are discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00647734
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  • 7
    Electronic Resource
    Electronic Resource
    Solute-solvent effects in the acidic dissociation of the ampholyte N-tris(hydroxymethyl)methylglycine (“tricine”) in 50 mass % methanol-water solvent (1974)
    Springer
    Journal of solution chemistry 3 (1974), S. 905-916 
    Details
    ISSN: 1572-8927
    Keywords: Acidic dissociation ; ampholyte dissociation ; dissociation constants ; ionization ; methanol-water solvents ; solute-solvent effects ; N-Tris(hydroxymethyl)methylglycine (“tricine”) ; zwitterions
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The pK values for the two acidic dissociation steps of the ampholyte N-tris-(hydroxymethyl)methylglycine (“tricine”) in 50 mass % methanol-water solvent have been determined by emf measurements of cells of the type Pt|H2(g, 1 atm), tricine buffer, Br−, AgBr|Ag over the range 5 to 50°C (pK 1)and 5 to 60°C (pK 2).The standard thermodynamic quantities ΔHo, ΔSo, and ΔC p o for the two dissociation processes have been derived and are compared with the corresponding values for tricine and the parent glycine in water and with those for other acids in 50 mass % methanol-water solvent. Both tricine and protonated tricine become weaker acids when methanol is added to the aqueous solvent. It appears that a strong stabilization of the zwitterion in water is responsible for this behavior. This conclusion is supported by comparing the changes in entropy and heat capacity for the dissociation of tricine with the values of these quantities for the dissociation of “model” acids of simple structure, such as ammonium ion and acetic acid.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00647944
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  • 8
    Electronic Resource
    Electronic Resource
    Breakdown of self-incompatibility during pistil development in Lycopersicon peruvianum by modified bud pollination (1989)
    Springer
    Sexual plant reproduction 2 (1989), S. 38-42 
    Details
    ISSN: 1432-2145
    Keywords: Self-incompatibility ; Bud pollination ; Stigma exudate ; Genetic load
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Stylar self-incompatibility barriers in L. peruvianum can be avoided if pollen germination and growth through immature pistils is promoted under specific environmental conditions approximately 2–3 days before the initiation of anthesis. Since immature stigmas lack sufficient exudate for pollen germination, the sandwiching of a thin layer of pollen germination medium between the stigma and a mineral oil layer containing pollen allows precocious pollen germination and some compatible pollen tube growth through the style. This procedure is rapid, inexpensive, applicable in the field, and makes efficient use of pollen. Consistent though low seed yields have been obtained. A high proportion of aborted seed, seedling lethals, and aberrant seedling phenotypes in selfed progeny indicate the presence of strong post-zygotic barriers to such selfing. No evidence for a reduction in the strength of the SI response with increasing pistil age was observed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00190117
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  • 9
    Electronic Resource
    Electronic Resource
    Solanum lycopersicoides gene introgression to tomato, Lycopersicon esculentum, through the systematic avoidance and suppression of breeding barriers (1989)
    Springer
    Sexual plant reproduction 2 (1989), S. 43-52 
    Details
    ISSN: 1432-2145
    Keywords: Intergeneric hybridization ; Introgression ; Cross-incompatibility ; Bud pollination ; Sterility
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary While Lycopersicon esculentum and Solanum lycopersicoides have been successfully hybridized, attempts at further direct gene introgression have been unsuccessful due to the presence of incompatibility barriers. A systematic study of the initial hybridization and subsequent backcrosses has identified multiple barriers to introgression. These barriers are expressed as pollen tube inhibition in the upper style and lower pistil, and failures in syngamy, zygote development, and sporogenesis. Upper style cross-incompatibility barriers were successfully avoided by bud pollinations using a stigma complementation procedure to allow pollen germination on otherwise unreceptive stigmas. The inhibition of pollen tube growth was observed in the lower pistil. A combination of environmental, plant, and genetic manipulations facilitated consistent pollen tube growth to the ovule micropyles in all crosses attempted. Failures at syngamy and early zygote formation proved to be the most difficult barriers to overcome — these were particularly severe in crosses to F1 hybrid plants. Progeny were obtained in all crossing combinations attempted except in the initial hybridization with S. lycopersicoides as the pistillate parent. Although the strong pre-zygotic barriers were overcome in this cross, further progress was restricted by post-zygotic failures. The capability to overcome pre-zygotic barriers and to excise and culture very young embryos has allowed plantlet recovery from male sterile F1 plants. Partially pollen-fertile F1 plants were recovered when relatively large F1 populations were generated from different S. lycopersicoides accessions. In general, barriers to introgression diminished with increased backcrossing, though exceptions were noted. Progeny from the second backcross to L. esculentum possessed adequate fertility to set self-seed under field conditions. Although all backcross progeny were developed from only a few F1 individuals, considerable genetic variability was recovered for fruit and vegetative characteristics. Potentially useful levels of disease resistance, particularly to Botrytis cinerea, were also recovered.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00190118
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  • 10
    Electronic Resource
    Electronic Resource
    Collagen-crystal relationships in bone. II. Electron microscope study of basic calcium phosphate crystalsThis paper is based in part on work performed under contract with the United States Atomic Energy Commission at the University of Rochester, Atomic Energy Project, Rochester, New York. This paper appears as University of Rochester Atomic Energy Project report, UR-232. (1953)
    New York, NY [u.a.] : Wiley-Blackwell
    American Journal of Anatomy 93 (1953), S. 25-59 
    Details
    ISSN: 0002-9106
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/aja.1000930103
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