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  • 1
    Electronic Resource
    Electronic Resource
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 99 (1993), S. 4011-4023 
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: It is shown how exact formulas for the longitudinal and transverse dielectric correlation times and complex polarizability tensor, of a single axis rotator with two equivalent sites may be found. This is accomplished by writing the Laplace transforms of the dipole autocorrelation functions as three term recurrence relations and solving them in terms of continued fractions. The solution of these recurrence relations, in the zero frequency limit, yields the correlation times in terms of modified Bessel functions of the first kind. The previous result of Lauritzen and Zwanzig for the longitudinal relaxation time, based on an asymptotic expansion of the Sturm–Liouville equation, is regained in the limit of high potential barriers.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 105 (1996), S. 2112-2118 
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: The correlation time of the positional autocorrelation function is calculated exactly for one-dimensional translational Brownian motion of a particle in a 2–4 double-well potential in the noninertial limit. The calculations are carried out using the method of direct conversion (by averaging) of the Langevin equation for a nonlinear stochastic system to a set of differential–recurrence relations. These, in the present problem, reduce on taking the Laplace transform, to a three-term recurrence relation. Thus the correlation time Tc of the positional autocorrelation function may be formally expressed as a sum of products of infinite continued fractions which may be represented in series form as a sum of two term products of Whittaker's parabolic cylinder functions. The sum of this series may be expressed as an integral using the integral representation of the parabolic cylinder functions and subsequently the Taylor expansion of the error function, thus yielding the exact solution for Tc. This solution is in numerical agreement with that obtained by Perico et al. [J. Chem. Phys. 98, 564 (1993)] using the first passage time approach while previous asymptotic results obtained by solving the underlying Smoluchowski equation are recovered in the limit of high barrier heights. A simple empirical formula which provides a close approximation to the exact solution for all barrier heights is also given. © 1996 American Institute of Physics.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    Oxford, UK and Boston, USA : Blackwell Publishers Ltd
    The @journal of political philosophy 6 (1998), S. 0 
    ISSN: 1467-9760
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Philosophy , Political Science
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    [s.l.] : Nature Publishing Group
    Nature 167 (1951), S. 655-656 
    ISSN: 1476-4687
    Source: Nature Archives 1869 - 2009
    Topics: Biology , Chemistry and Pharmacology , Medicine , Natural Sciences in General , Physics
    Notes: [Auszug] Analyses have been carried out on the products of prolonged photolysis (up to 24 hr. for at least 90 per cent decomposition) of 200 mm. acetaldehyde at various temperatures and with /0 10~10 Nhv. cm.-'sec.-1, X = 2537-3130 A. Table 1 shows the results obtained (after removal of residual aldehyde). ...
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    [s.l.] : Nature Publishing Group
    Nature 203 (1964), S. 541-542 
    ISSN: 1476-4687
    Source: Nature Archives 1869 - 2009
    Topics: Biology , Chemistry and Pharmacology , Medicine , Natural Sciences in General , Physics
    Notes: [Auszug] To explain the correlation between internode elongation and acid invertase-level, we have postulated that the outer space and vacuolar acid invertase of young, rapidly expanding cells co-operate to maintain a constant high level of hexoso available in the cytoplasm. The regulatory role of this ...
    Type of Medium: Electronic Resource
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  • 6
    ISSN: 1433-7339
    Keywords: Key words Radiation therapy ; Xerostomia ; Phase II study
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract  One of the major side effects of radical radiation therapy for head and neck malignancies is xerostomia, or dryness of the mouth. There is no clearly effective treatment for this condition, but we have observed that patients in our practice believe that their symptoms improve significantly when using two "over-the-counter" oral comfort products – Biotene (toothpaste, mouthwash and chewing gum) and Oralbalance gel. We decided to study these agents in a formal phase II study to evaluate their usefulness in patients with postirradiation xerostomia. Twenty-eight patients with post-irradiation xerostomia were entered on the study. All had biopsy-proven carcinoma of the nasopharynx, oropharynx, oral cavity, hypopharynx or larynx, and had received primary radiotherapy with curative intent (≥50 Gy in 20 fractions) more than 4 months before study entry. More than 75% of both parotid glands were included in the primary radiation field. There was no clinical evidence of recurrent disease. Patients were provided with a 2-month supply of Biotene mouthwash, toothpaste, chewing gum and Oralbalance gel. Response was evaluated 1 and 2 months after study entry using a patient-completed visual analogue scale to assess the severity of xerostomia and its effects on quality of life. For analysis, the scored baseline was subtracted from the later scores to assess change. Patients with an increase of 10 mm from their baseline score on the visual analogue scale were classified as having responded to the treatment intervention, and those with an increase of ≥25 mm from their baseline score were classified as having experienced a major improvement in their symptoms. After 2 months of treatment, 15 patients (54%) reported an improvement in intraoral dryness and 10 of these patients (36%) reported a major improvement. Similar proportions of patients (46% some improvement, 25% major improvement) reported an improvement in their ability to eat normally. Seventeen patients (61%) reported an improvement in oral discomfort, and 12 of these (43%) had a major improvement in their symptoms. The results of this study suggest that the use of Biotene (mouthwash, toothpaste and chewing gum) and Oralbalance gel can improve many of the symptoms of radiation-induced xerostomia. A placebo effect could account for many of the observed improvements in symptoms, and in order to assess the role of these agents in the management of patients with postirradiation xerostomia a randomised phase III study is needed.
    Type of Medium: Electronic Resource
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  • 7
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    Berkeley, Calif. : Periodicals Archive Online (PAO)
    Journal of the history of philosophy. 19:1 (1981:Jan.) 39 
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  • 8
    Electronic Resource
    Electronic Resource
    Springer
    Experimental brain research 74 (1989), S. 105-115 
    ISSN: 1432-1106
    Keywords: Somatosensory cortex ; Thalamocortical neurons ; Sensory convergence
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Ninety thalamocortical (TC) neurons were recorded extracellularly in ventrobasal thalamus of halothane-anesthetized cats. Projections of all of these neurons to specific subdivisions of somatosensory cortex were identified by their antidromic invasion following intracortical microstimulation restricted to these subdivisions. Collision-extinction tests were used to document excitatory inputs to TC neurons from afferent fibers of forelimb nerves stimulated electrically. Thirty-nine TC neurons (43% of sample) were excited from at least one forelimb nerve. Fifteen TC neurons were activated from two or more forelimb nerves. Combinations of effective nerves included ones innervating topographically different regions of forelimb. Neurons projecting to area 1–2 were least likely to be activated from more than one nerve. Seven TC neurons activated by electrical stimulation of nerve trunks were tested also with two distinct forms of mechanical somatic stimuli, i.e., hair bending and vibration, and with intradermal electrical stimuli. These tests revealed convergent inputs from hairy and glabrous skin. We conclude that there is a population of neurons, located in ventrobasal thalamus, which is capable of conveying multiple inputs to each of the subdivisions of primary somatosensory cortex. These neurons could be involved in forming properties of feature-extracting neurons of somatosensory cortex.
    Type of Medium: Electronic Resource
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  • 9
    ISSN: 1432-2137
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mathematics
    Notes: Zea mays L.) and soybean [Glycine max (L.) Merr.]. Chemical and chemical-mechanical weed management had similar corn net returns under moldboard plow ($370 and $355 ha-1, respectively) and chisel tillage ($282 and $287 ha-1). Mechanical weed management had less net returns in moldboard plow ($302 ha-1) and chisel tillage ($121 ha-1) because of 15% lesser corn densities and greater weed densities, especially in chisel tillage. In soybean, mechanical weed management in moldboard plow tillage had similar weed density (1.5 weeds m-2) lower yield (2.71 Mg ha-1), but similar net return ($107.50 ha-1) compared with chemical (1.3 weeds m-2, 2.92 Mg ha-1, and $85.60 ha-1, respectively) and chemical-management (1.0 weeds m-2, 2.78 Mg ha-1 and $99.35 ha-1, respectively). In chisel tillage, mechanical weed management had greater weed density (7.4 weeds m-2), lower yield (2.2 Mg ha-1), and lower net return (-$7.80 ha-1) compared with chemical (1.9 weeds m-2, 2.8 Mg ha-1, and $56.80 ha-1, respectively) and chemical-mechanical weed management (1.9 weeds m-2, 2.4 Mg ha-1, and $27.30 ha-1). Corn and soybean growers apparently can adopt chemical-mechanical weed management and maintain net returns. Soybean growers who use moldboard plow tillage can also adopt mechanical weed management and maintain net returns.
    Type of Medium: Electronic Resource
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  • 10
    Electronic Resource
    Electronic Resource
    Springer
    Naunyn-Schmiedeberg's archives of pharmacology 323 (1983), S. 321-327 
    ISSN: 1432-1912
    Keywords: Iprindole ; Rat anococcygeus muscle ; Noradrenergic transmission
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary 1. The effects of iprindole on the contractile responses to field stimulation and to exogenously applied agents have been studied in the rat anococygeus muscle. In addition the effects on the spontaneous overflow of 3H and that induced by field stimulation (following preloading of the tissue with [3H]-noradrenaline) are reported. 2. Iprindole (10−7−5×10−6 M) had no effect on the contractile responses to acetylcholine. 3. Iprindole at 10−7 or 10−6 M was equieffective in potentiating the contractile responses to either field stimulation or to noradrenaline. With a higher concentration of iprindole (5×10−6 M) the potentiation was greater. The responses to oxymetazoline were potentiated and inhibited by iprindole at 10−8 and 10−7 M, respectively. Iprindole at 10−6 M potentiated the responses to tyramine. 4. The effects of iprindole at 10−7 and 5×10−6 M on the responses to field stimulation and to noradrenaline were not altered by the presence of ouabain (5×10−5 M), neostigmine (10−6 M) or yohimbine (10−7 M). 5. In the presence of desipramine (10−6 M), iprindole at 10−7 M potentiated the contractile responses to field stimulation and to noradrenaline. The higher concentrations of iprindole (10−6 and 5×10−6 M) inhibited the contractile responses to field stimulation and to noradrenaline in the presence of desipramine. 6. Iprindole (10−7 M) had no effect on the relaxant responses to field stimulation. 7. Iprindole at 10−7 or 10−6 M had no effect on the spontancous overflow of 3H or that induced by field stimulation at 2Hz. Iprindole (5×10−6 M) increased the spontaneous overflow and that induced by field stimulation. This effect was not altered by the presence of desipramine (10−6 M). 8. These results suggest that iprindole has three effects on noradrenergic transmission in the rat anococcygeus muscle: an ability to potentiate the contractile responses to field stimulation and to α-adrenoceptor agonists by a postjunctional mechanism. Secondly, under certain conditions (e.g., in the absence of neuronal uptake) iprindole acts as a postjunctional α-adrenoceptor antagonist. At high concentrations (5×10−6 M) iprindole increased the spontaneous overflow of 3H and that induced by field stimulation (following preloading of the tissue with [3H]-noradrenaline) by a desipramineinsensitive mechanism.
    Type of Medium: Electronic Resource
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