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  • 1970-1974  (30)
  • 1965-1969  (14)
  • Chemistry  (38)
  • Life and Medical Sciences  (5)
  • Avoidance  (1)
  • 1
    Electronic Resource
    Electronic Resource
    A controlled comparison of drug effects on escape from conditioned aversive stimulation (“anxiety”) and from continuous shock (1971)
    Springer
    Psychopharmacology 22 (1971), S. 323-332 
    Details
    ISSN: 1432-2072
    Keywords: Chlorpromazine ; Chlordiazepoxide ; Avoidance ; Anxiety ; Escape
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Squirrel monkeys were presented with two stimuli in alternation, separated by time out periods during which neither was present. One was white noise accompanied by irregularly spaced pulses of shock, the other continuous shock at a lower intensity. Following an interval of time which varied in an unpredictable sequence, the next depression of the response lever turned the stimulus off. The schedule on which termination was possible was identical for the two stimuli, and the intensity of the continuous shock was adjusted to a level that produced approximately equal frequencies of pressing, typically from 40 to 80 responses per minute. Doses of chlordiazepoxide ranging from 2.5 to 10.0 mg/kg, i.p., produced a significantly greater decrease in the rate of response in the presence of the continuous shock than in the presence of the noise. On the other hand, doses of chlorpromazine ranging from 0.25 to 1.0 mg/kg, i.p., produced no differential effect. Previous findings of selective action on behavior that terminates signals paired with shock (avoidance) may be related to differences in experimental contingencies or in the pre-drug strength of the two performances compared, rather than to the effect of chlorpromazine on an experimental analogue of human anxiety.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00406871
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  • 2
    Electronic Resource
    Electronic Resource
    Noncomplementarity in base sequences between the cohesive ends of coliphages 186 and λ and the formation of interlocked rings between the two DNA's (1967)
    New York : Wiley-Blackwell
    Biopolymers 5 (1967), S. 953-966 
    Details
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The half molecules of 186 DNA have been isolated by the Hg(II)-Cs2SO4 density gradient centrifugal ion technique. The buoyant densities of the two halves in CsCI at 25°C. are 1.713 and 1.709 g./cm.3, corresponding to GC contents of 54% and 50%, respectively. Similarly, 5-bromouracil labeled λ DNA halves were separated. The isolation of the four DNA halves made it possible to test for homology in base sequences between the cohesive ends of λ and those of 186. There was no indication of any significant homology in base sequences between the cohesive ends of the two DNA's, as indicated by the absence of a band with intermediate buoyant density in CsCI when either half of 186 DNA was annealed with either half of 5-bromouracil labeled λ DNA and then centrifuged. The lack of cohesion between the two DNA's made it possible to demonstrate unequivocally the formation of interlocked rings (catenanes) between the two DNA's. The existence of a dimeric catenane is evidenced by the formation of a species of intermediate buoyant density when 5-bromouracil labeled λ DNA is cyclized in the presence of cyclic 186 DNA of a relatively high concentration. The molecular weight of one DNA relative to the other can be calculated from the position of the dimeric catenane in a density gradient by using the method of Baldwin. The result was in complete agreement with our previous measurements from the sedimentation coefficients and by electron microscopy. The probability of dimeric catenane formation when one DNA is cyclized in the presence of another DNA is discussed. The experimental results agree with the theoretical expectation.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bip.1967.360051008
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  • 3
    Electronic Resource
    Electronic Resource
    A re-examination of the cloacal sacs and gland of the blind snake, Leptotyphlops dulcis (Reptilia: Leptotyphlopidae) (1971)
    New York, NY : Wiley-Blackwell
    Journal of Morphology 133 (1971), S. 273-280 
    Details
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The cloacal sacs of Leptotyphlops dulcis are nonglandular, posterior evaginations of the cloaca. The median cloacal gland is tubuloalveolar. Similar unpaired cloacal glands as well as paired sacs are noted in certain colubrid snakes. Terminology applied to these cloacal derivatives is discussed, and a standardization of names is provided.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jmor.1051330303
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  • 4
    Electronic Resource
    Electronic Resource
    Viscosities of moderately concentrated solutions of polyethylene in ethane, propane, and ethylene (1969)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 13 (1969), S. 117-131 
    Details
    ISSN: 0021-8995
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: The viscosities of moderately concentrated solutions of low-density polyethylenes in ethane, propane, and ethylene have been measured at low shear rate in the temperature range of 150-250°C and in the pressure range of about 15000-30000 psi. Within the precision of the measurements, the relative viscosity is independent of pressure over the range investigated but increases as the solvent is changed from propane through ethane to ethylene. The activation energy for the relative viscosity in ethane varies from about 0.5 to 2.5 kcal/mole as the concentration changes from 5 to 15 g/dl. Effects of polymer concentration and molecular weight on solution viscosity in ethane at 150°C have been determined, and all of the data can be represented by a single straight-line plot of the logarithm of relative viscosity versus the intrinsic viscosity (in p-xylene at 105°C) times concentration. This simple relation is valid over wide ranges of polymer concentration and molecular weight and over more than two orders of magnitude of relative viscosity. The solution viscosities of the polyethylenes in the three supercritical fluid solvents used appear surprisingly low at first sight. This behavior is partly a result of the low solvent viscosities but also might mean that the polymer has an abnormally low segmental friction factor compared to that in solutions under more familiar conditions.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/app.1969.070130113
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  • 5
    Electronic Resource
    Electronic Resource
    Poly(vinyl alcohol) hydrogels. Formation by electron beam irradiation of aqueous solutions and subsequent crystallization (1973)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 17 (1973), S. 3779-3794 
    Details
    ISSN: 0021-8995
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Aqueous solutions of poly(vinyl alcohol) were submitted to varying doses of electron beam irradiation. By modification of the classical Flory-Huggins equations appropriate to the initial state of solution of the polymer, the molecular weight between crosslinks, Mc, was calculated as a function of radiation dose, initial polymer concentration, and temperature. Following crosslinking in the solution state, crystallization was induced by dehydrating the network at temperatures above 90°C. Following dehydration, the polymer network was reequilibrated with water and its tensile properties compared with identically prepared hydrogels not subjected to crystallization by dehydration. Greatly enhanced values of ultimate tensile strength and resistance to tear result from the treatment producing crystallization, compared with those of the crosslinked but not previously dehydrated gels.
    Additional Material: 11 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/app.1973.070171219
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  • 6
    Electronic Resource
    Electronic Resource
    Kinetics studies in a continuous steady state hollow fiber membrane enzyme reactor (1974)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 16 (1974), S. 1113-1122 
    Details
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Porous hollow cellulose fibers have been used to separate a nonflowing enzyme solution of alkaline phosphatase from a continuous flow of substrate. The porosity of the hollow fiber membrane allows the substrate and product to diffuse freely through the membrane while restricting the permeation of the enzyme. The resulting “immobilized” enzyme system has been shown to behave as a continuous reactor - converting p-nitrophenylphosphate to p-nitrophenol. By varying the concentrations, flow rate, etc., either diffusion or enzyme kinetics can be studied. The continual influx of product and removal of substrate at steady state allows the study of kinetics of relatively short half-life enzymes and unstable systems.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bit.260160811
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  • 7
    Electronic Resource
    Electronic Resource
    Microflotation: New low gas-flow rate foam separation technique for bacteria and algae (1966)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 8 (1966), S. 135-151 
    Details
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Foam separation of microorganisms has been investigated with varying success by many workers, usually at high rates of gas flow. Microflotation was developed to overcome some of the disadvantages inherent in these high gas-flow-rate processes and is introduced in this paper as a new technique for the foam separation of microorganisms at low gas-flow rates. With microflotation, a stable surface phase is produced by adding an insoluble collector such as a long-chain fatty acid or amine. The formation of an insoluble surface phase eliminates the need for high foaming. Low rates of gas flow are used resulting in a more efficient separation and a less voluminous and drier surface phase upon which to collect the microorganisms. The efficiency of this technique is also improved by using flotation aids such as frothers and flocculents. Frothers are used to improve the collector properties of the surfactant and to refine further the small bubbles produced by a very fine sparger. Small concentrations of flocculents, such as alum, are used to partially agglomerate the organisms and provide sites for adsorption of collector. The work described in this paper is preliminary in nature, designed to illustrate that a low flow-rate process may be used to separate microorganisms and to stimulate further research. The applications discussed are removal of the bacterium, Escherichia coli, and alum, and two species of algae, Chlamydomonas reinhardtii and Chlorella ellipsoidea, using stearylamine without alum. The frother used was ethanol.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bit.260080112
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  • 8
    Electronic Resource
    Electronic Resource
    Kinetics of protein release from yeast sonicated in batch and flow systems at 20 kHz (1972)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 14 (1972), S. 33-42 
    Details
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The release constant, k, of brewers yeast sonicated at powers up to 200 W at 20 kHz has been shown to be independent of cell concentration up to values of 60 g made up to 100 ml. It is inversely proportional to the volume of the treatment vessel in the range 75 to 450 ml, and almost proportional to the input acoustic power from 60 to 195 acoustic watts. A flow system is described and a relationship linking protein release, flow rate, and the protein release constant, determined from batch experiments, is derived. Good agreement between the theoretical prediction of protein release and experimental results with the flow system was obtained.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bit.260140105
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  • 9
    Electronic Resource
    Electronic Resource
    Optimization of the release of undegraded material extracted from cells by ultrasound (1974)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 16 (1974), S. 659-673 
    Details
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The time course of release of intact labile material from cells by cavitating ultrasound is examined. Curves are presented which show the yield of intact subcellular components obtainable from cells as a function of sonication time for various values of the ratio of inactivation rate to release rate. The general cases where inactivation of released product is concentration dependent (chemical) and concentration independent (mechanical) are considered.For a flow system the time of attainment of equilibrium concentration of active product is analyzed as a function of flow rate, release rate, inactivation rate, and volume of chamber. Curves of optimal yields to be expected for batch and flow systems are presented. It is shown that sonochemical inactivation can be made negligible by sonication of high cell concentration suspensions.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bit.260160508
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  • 10
    Electronic Resource
    Electronic Resource
    Fluid flow through woven screens (1968)
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 14 (1968), S. 415-420 
    Details
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: A packed bed model has been adopted to develop a general correlation applicable to the flow of Newtonian fluids through all types of woven metal screens. Both of the main theoretical approaches to studying pressure drop in packed systems have been used by visualizing the screen as a collection of submerged objects with surface area to unit volume ratio a for laminar flow, and as a bundle of tubes of diameter D for turbulent flow. In the usual manner viscous and inertial energy losses are added to give an expression for the total pressure loss. Rearrangement of the general equation to the form of a friction factor yields a unique definition of the Reynolds number for screens NRe = ρu/μa2D. Procedures are described for collection of pressure drop-velocity data for the flow of nitrogen and helium through plain square, full twill, fourdrinier, plain dutch, and twilled dutch weaves. The data are used to derive a viscous resistance coefficient α = 8.61 and an inertial resistance coefficient β = 0.52. The validity of the correlation equation is tested by using additional data from the literature. The correlation successfully predicts pressure drop for a Reynolds number range of 0.1 to 1,000, void fractions from 0.35 to 0.76, screen pore diameters from 5 to 550 μ, mesh sizes from 30 to 2,400 wires/in., and surface area to unit volume ratios from 1,200 to 29,000 ft.-1.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/aic.690140315
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