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  • 1
    Electronic Resource
    Electronic Resource
    Preparation of dealuminized mordenite (1976)
    s.l. : American Chemical Society
    Inorganic chemistry 15 (1976), S. 295-297 
    Details
    ISSN: 1520-510X
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1021/ic50156a011
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  • 2
    Electronic Resource
    Electronic Resource
    The Synthesis of Compounds for the Chemotherapy of Tuberculosis. I. Heterocyclic Thiosemicarbazide Derivatives (1951)
    s.l. : American Chemical Society
    The @journal of organic chemistry 16 (1951), S. 1121-1125 
    Details
    ISSN: 1520-6904
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1021/jo50001a015
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  • 3
    Electronic Resource
    Electronic Resource
    The Synthesis of Compounds for the Chemotherapy of Tuberculosis. VI. Hydrazine Derivatives (1956)
    s.l. : American Chemical Society
    The @journal of organic chemistry 21 (1956), S. 530-533 
    Details
    ISSN: 1520-6904
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1021/jo01111a012
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  • 4
    Electronic Resource
    Electronic Resource
    Pressure-Tight Infrared Absorption Cell for Liquids (1949)
    s.l. : American Chemical Society
    Analytical chemistry 21 (1949), S. 1474-1476 
    Details
    ISSN: 1520-6882
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1021/ac60036a011
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  • 5
    Electronic Resource
    Electronic Resource
    The Chemotherapy of Tuberculosis. III. Thiosemicarbazide Derivatives (1952)
    s.l. : American Chemical Society
    Journal of the American Chemical Society 74 (1952), S. 2106-2107 
    Details
    ISSN: 1520-5126
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1021/ja01128a509
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  • 6
    Electronic Resource
    Electronic Resource
    The Synthesis of Compounds for the Chemotherapy of Tuberculosis. II. Hydroxamic Acid Derivatives (1951)
    s.l. : American Chemical Society
    Journal of the American Chemical Society 73 (1951), S. 5455-5456 
    Details
    ISSN: 1520-5126
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1021/ja01155a519
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  • 7
    Electronic Resource
    Electronic Resource
    The uptake and metabolism of urea by Chara australis: IV. Symport with sodium—A slip model for the high and low affinity systems (1993)
    Springer
    The journal of membrane biology 136 (1993), S. 263-271 
    Details
    ISSN: 1432-1424
    Keywords: Sodium ; Urea ; Symport ; Cotransport ; Charophytes ; Slip model
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract We have previously investigated the electrogenic influx of urea in Chara, and the urea- and sodium-dependent membrane current. We have shown that there is a sodium-stimulated component of urea influx and a urea-stimulated component of sodium influx, and that these are of the same size. We conclude that the electrogenic inward transport of urea, and of its analogues acetamide and acrylamide, is by sodium symport, with a stoichiometric ratio of 1∶1. The kinetics of the fluxes and currents show two different K M values for sodium in different cells and two different kinds of kinetics for the effect of urea on membrane current, one of which fits the Michaelis-Menten equation, while the other shows a maximum and fits the difference of two Michaelis-Menten terms, suggesting a phenomenon like cis-inhibition. Similarities in kinetic characteristics between the inhibitory site and the electrically silent uptake site (System II) lead us to suggest that the same protein may be responsible for both the low-K M, electrogenic influx of urea (System I) and the high-K M, electrically silent influx by System II. We suggest a “slip” model for urea uptake in Chara.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00233665
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  • 8
    Electronic Resource
    Electronic Resource
    Bicarbonate assimilation by fresh-water charophytes and higher plants: I. Membrane transport of bicarbonate ions is not proven (1980)
    Springer
    The journal of membrane biology 57 (1980), S. 51-58 
    Details
    ISSN: 1432-1424
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Summary Although it is generally believed thatChara and some fresh-water angiosperms transport bicarbonate ions inwards across their plasma membranes, there has been no direct demonstration of such transport in these plants. The (indirect) arguments for their transporting HCO 3 − are arguments against the inward diffusion of CO2 at the observed rates. They rest on calculations of the equilibrium concentration of CO2 or of the maximum rate at which CO2 might be produced from HCO 3 − at the pH of the medium outside the cells. SinceChara acidifies the medium over about half the cell surface during C assimilation, these calculations have been based on questionable premises. We propose a model forChara in which the acidification is attributed to active efflux of H+, and we calculate that both the equilibrium concentration of CO2 and its rate of production outside the cell can be high enough to support the observed rates of C assimilation, without postulating transport of the species HCO 3 − or H2CO3. Calculations are presented also for alternative models in which there is membrane transport of HCO 3 − . The first includes symport of H+ with HCO 3 − , again dependent on active H+ efflux. In the second, there is active electrogenic transport of HCO 3 − . In this case the low pH in the medium outside the cell is caused by the dissociation of H2CO3 produced by hydration of CO2 which leaks from the cell cytoplasm. All three models are consistent with the observations to date, but the first is more economical of postulates. It can also explain the apparent transport of HCO 3 − by fresh-water angiosperms such asEgeria.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01868985
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  • 9
    Electronic Resource
    Electronic Resource
    Amine uniport at the plasmalemma of charophyte cells II. Ratio of matter to charge transported and permeability of free base (1979)
    Springer
    The journal of membrane biology 49 (1979), S. 283-296 
    Details
    ISSN: 1432-1424
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Summary We have previously reported that inward positive current flows across the plasmalemma of voltage-clampedChara cells when ammonia or methylamine is added to the medium. This is attributed to (inward) uniport of the cation. We have measured the stoichiometric ratio of the quantity of methylamine transported to the quantity of positive charge transported. We find 0.9 mol/faraday from pH 5.7 to 8.5, as expected if the cation flux is much larger than that of free base. The ratio increases progressively above pH 9 as the concentration of free base becomes comparable with that of cation: the fluxes fit those predicted if neutral methylamine has a permeability of 1.8 × 10−5 m/sec. This is comparable with the permeability of the methylammonium ion, 6×10−6 m/sec, at low concentration and −200 mV, as previously reported. Low concentrations of NH 4 + are found to inhibit entry of CH3NH 3 + when membrane PD is constant. Half maximum inhibition is found at ∼20 μm NH 4 + , in agreement with the apparentK M for NH 4 + binding to its uniporter site. This suggests that NH 4 + and CH3NH 3 + enter by the same uniporter, competing for binding to its binding site.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01871123
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  • 10
    Electronic Resource
    Electronic Resource
    Amine uniport at the plasmalemma of charophyte cells: I. Current-voltage curves, saturation kinetics, and effects of unstirred layers (1979)
    Springer
    The journal of membrane biology 49 (1979), S. 21-55 
    Details
    ISSN: 1432-1424
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Summary In voltage-clamped cells of the algaeChara andNitella an inward current of positive charge occurs when NH 4 + or CH3NH 3 + is added to the external medium. There is a simultaneous increase in membrane conductance, agreeing with earlier evidence that the current represents the inward uniport of the amine ion. We have obtained current-voltage curves for this uniport, and show the effect on their shape caused by the unstirred layer of solution adjacent to the cell membrane. The current-voltage curves for CH3NH 3 + , which are less affected by the unstirred layer, are concave towards the current axis, show no saturation with membrane PD in the range −100 to −300 mV, and show saturation as the concentration is raised. The dependence of current on concentration follows a Michaelis-Menten relation, the parameters having the following values at −200 mV: $$\begin{gathered} V_m = up to 200 mA m^{ - 2} for both substrates \hfill \\ K_M = 3 \mu M for NH_4^ + and 200\mu M for CH_3 NH_3^ + . \hfill \\ \end{gathered} $$ BothV m andK M depend on membrane potential, approximately as exp(−Fψ/6RT) and exp(Fψ/3RT), respectively. The results suggest a transport channel with a single, selective binding site below the membrane surface and a single potential energy barrier at the center of the membrane. The rate of transport falls as the cell takes up amine, and also varies markedly from culture to culture. The significance of this transport for the biology of the charophyte plant is discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01871038
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