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  • 1
    Electronic Resource
    Electronic Resource
    Microwave excited electrodeless discharge tubes containing organo-sulfur and phosphorus compounds (1969)
    s.l. : American Chemical Society
    Analytical chemistry 41 (1969), S. 1851-1853 
    Details
    ISSN: 1520-6882
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1021/ac60282a043
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  • 2
    Electronic Resource
    Electronic Resource
    Ecology and behavior ofGnamptogenys horni (Formicidae: Ponerinae) (1994)
    Springer
    Insectes sociaux 41 (1994), S. 255-262 
    Details
    ISSN: 1420-9098
    Keywords: ants ; Gnamptogenys ; behavior ; polyethism ; recruitment
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary In order to examine social behavior in the little-studied ponerine ant genusGnamptogenys, detailed observations were made on captive colonies ofG. horni. Compilation of a behavioral repertory gave evidence of age-based division of labor, with old ants more likely to forage and young ants more likely to tend brood. Workers were observed to line the walls of their nests with pieces of old cocoons, a behavior referred to as wallpapering and previously known from only one other ant species. Evidence was obtained for the use of trail recruitment pheromones in foraging and in nest-moving. Examination of prey remains in natural nests indicated thatG. horni feeds principally on a wide variety of ants, but also on other arthropods.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01242296
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  • 3
    Electronic Resource
    Electronic Resource
    Division of labor inPonera pennsylvannica (Formicidae: Ponerinae) (1994)
    Springer
    Insectes sociaux 41 (1994), S. 43-61 
    Details
    ISSN: 1420-9098
    Keywords: Ant ; caste ; polyethism ; division of labor ; Ponerinae
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary We examined division of labor and colony demography in the antPonera pennsylvannica. Observation of three colonies with individually marked workers revealed a high degree of interindividual behavioral variation and a rough but consistent division of labor between brood tenders and foragers. This division was present both in colonies consisting entirely of workers produced in the previous summer and in colonies containing freshly eclosed ants. Two colonies showed typical age-based polyethism, with young ants focusing on brood care and overwintered ants on foraging. No such age basis was detected in the third colony. This difference may relate to variability in brood production schedules. Colonies showing temporal polyethism had two peaks of brood production and thus had relatively large brood populations when the first young workers eclosed, while the third colony had only one peak and little brood for the young workers to tend. Even if young ants have a lower threshold for brood care, it may have been concealed in the latter situation. Demographic data indicate that natural colonies produce one brood per year and that workers typically eclose into colonies with relatively low brood care demands. This suggests that overwintered workers do most of a colony's work and that the division of labor among overwintered ants is the more important one under natural conditions. The basis of this division is as yet unknown. These results also suggest that small colony size, univoltine brood schedule and a close association between foraging and brood care do not preclude division of labor among specialized castes, as has been suggested for another ponerine species (Traniello 1978).
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01240572
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  • 4
    Electronic Resource
    Electronic Resource
    Lack of a pharmacokinetic interaction between oral famciclovir and allopurinol in healthy volunteers (1994)
    Springer
    European journal of clinical pharmacology 46 (1994), S. 355-359 
    Details
    ISSN: 1432-1041
    Keywords: Famciclovir ; Herpes ; Allopurinol ; pharmacokinetic interaction ; xanthine oxidase
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Abstract Famciclovir has been shown to have potent and selective activity against herpesviruses. The possibility of a pharmacokinetic interaction between the anti-viral agent, famciclovir and allopurinol has been investigated in twelve healthy male volunteers following a single oral dose of famciclovir (500 mg) in the presence and absence of steady-state levels of allopurinol (300 mg). Similarly, the pharmacokinetic profiles of allopurinol and oxypurinol prior to and following a single dose of famciclovir were compared. Mean values of Cmax, AUC and terminal-phase half-life for penciclovir following administration of famciclovir alone at 3.3 μg·ml-1, 8.8 μ·h·ml-1 and 2.1 h, respectively were unchanged by co-administration of allopurinol. Similarly, mean urinary recovery and renal clearance values of penciclovir following famciclovir alone were 56.8% and 271·h-1, and when given with allopurinol 59.7% and 27.51·h-1, respectively. No evidence of accumulation of the inactive precursor to penciclovir, BRL 42359, was noted as a result of co-administration of the two drugs. Mean steady-state Cmax, AUC and terminal-phase half-life values for allopurinol after co-administration of allopurinol with famciclovir also appeared unchanged from values obtained after dosing of allopurinol alone, at 2.12 μg·ml-1, 5.73 μg·h·ml-1 and 1.38h, respectively. Mean Cmax and AUC values of the active metabolite of allopurinol, oxypurinol were 11.2 μg·ml-1 and 96.0 μg·h·ml-1, respectively, and these were also unaltered by co-administration of famciclovir with allopurinol, with values of 10.6 μg/ml and 89.8 μg·h/ml, respectively. In summary, no evidence of a pharmacokinetic interaction between allopurinol and famciclovir was observed when the two drugs were given concomitantly to healthy volunteers.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00194405
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  • 5
    Electronic Resource
    Electronic Resource
    Rotational state distributions from vibrational autoionization of H2 revisited (1990)
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 92 (1990), S. 1831-1838 
    Details
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: Photoelectron spectra of vibrationally autoionized (X 2Σ+g)np, v=1,2 Rydberg states of H2 were obtained by using an optical–optical double-resonance technique. The spectra were obtained by using a hemispherical electrostatic electron energy analyzer that had sufficient resolution to determine the rotational state distributions of the H+2 ions. The ionization process occurred in a magnetic and electric field-free region. All of the results are consistent with the assumptions that the photoelectrons are ejected as p waves and that spin effects are negligible. This is in sharp contrast to our earlier results obtained by using a magnetic bottle electron spectrometer, in which the ionization process occurred in a 0.5–1.0 T magnetic field [J. L. Dehmer et al., J. Chem. Phys. 90, 6243 (1989)]. It is concluded that the magnetic field can significantly modify the rotational distributions observed for vibrational autoionization. The implications of this conclusion are discussed, with particular attention to other experiments performed with the magnetic bottle spectrometer.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.458065
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  • 6
    Electronic Resource
    Electronic Resource
    Vibrational branching ratios following two-color excitation of autoionizing np Rydberg states of H2 (1988)
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 89 (1988), S. 75-84 
    Details
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: Two-color resonantly enhanced multiphoton ionization-photoelectron spectroscopy (REMPI-PES) was used to determine vibrational branching ratios following autoionization of the ungerade npσ 1Σ+u and npπ 1Πu Rydberg states of H2. In this two-step experiment, one laser used to excite the two photon transition to the E,F 1Σ+g, v'=E2, J'=1 state, and a second laser was used to access the autoionizing Rydberg states near the H+2X 2Σ+g, v+=2 ionization limit. Electrons corresponding to the formation of H+2X 2Σ+g, v+=0 and 1 were collected and energy analyzed using a magnetic bottle electron spectrometer. In agreement with the well-known propensity rule for vibrational autoionization, the vibrational branching ratios strongly favor the final ionic state that corresponds to the minimum change in vibrational quantum number. In general, the branching ratio into the v+=1 channel is 94%–96%, while that into the v+=0 channel is 4%–6%; however, two major deviations from this trend were observed for Rydberg states that are perturbed by the 3pπ 1Πu, v=9 and 4pσ 1Σ+u, v=7 states. Although these low n/high v interlopers were not observed in the present work (since their ionization efficiency is near zero), interchannel coupling apparently causes their influence to be felt by nearby Rydberg states, resulting in v+=0 branching ratios as high as 18%. A number of additional studies suggested by these initial results are discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.455463
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  • 7
    Electronic Resource
    Electronic Resource
    Photoionization dynamics of H2 C 1Πu: Vibrational and rotational branching ratios (1987)
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 87 (1987), S. 3288-3298 
    Details
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: Angle-integrated, rotationally resolved photoelectron spectra were determined for three-photon resonant, four-photon (3+1) ionization of H2 via the C 1Πu, v'=0–4 intermediate levels using a magnetic bottle electron spectrometer. The results confirm and extend our previous angle-resolved results obtained using a hemispherical electron energy analyzer. As predicted by both Franck–Condon factors and recent ab initio Hartree–Fock level calculations, ionizing transitions in which the vibrational level of the resonant intermediate state is preserved in the ion are most probable; however, large deviations from theoretical expectations are observed for photoionization of all intermediate levels. These deviations take the form of a progressive broadening of the ionic vibrational distribution as the vibrational level of the resonant intermediate state is increased. The rotational branching ratios also exhibit systematic variations with both the vibrational level of the C 1Πu state and the vibrational level of the ion. Photoelectron signal from ionization of electronically excited atomic hydrogen produced in the photodissociation of H2 C 1Πu is also observed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.453022
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  • 8
    Electronic Resource
    Electronic Resource
    Alignment of the E,F 1Σ+g, v'E=1 state of H2 by two-photon excitation (1990)
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 92 (1990), S. 4734-4739 
    Details
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: The alignment of the E,F 1Σ+g, vE=1 state of H2 produced by two-photon excitation from the X 1Σ+g, v‘=0 ground state was investigated using two different techniques. First, in a single-color experiment, photoelectron angular distributions were measured for the two-photon resonant, three-photon ionization of H2 via the Q(0) and Q(1) transitions to the E,F 1Σ+g, v'E=1 state. The photoelectron angular distributions are consistent with an unaligned E,F 1Σ+g, vE=1, J'=1 state. Second, in a two-color experiment, the photoionization spectra of several vibrationally autoionizing (X 2Σ+g)np, v=1 Rydberg states excited from the v'E=1, J'=1 level of the E,F 1Σ+g state were measured as a function of the relative polarizations of the pump and probe beams. The polarization dependence of the relative intensities of the P(1) and Q(1) transitions was used to determine the alignment of the E,F 1Σ+g, vE=1, J'=1 state produced by the pump laser. Consistent with the angular distribution measurements, the polarization results indicate that the populations in the M'=0 and M'=±1 levels of the E,F 1Σ+g, v'E=1, J'=1 state are equal, within the experimental uncertainty of 15%.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.457691
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  • 9
    Electronic Resource
    Electronic Resource
    Two-photon spectroscopy of Rydberg states of NO (1989)
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 90 (1989), S. 5971-5981 
    Details
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: Two-photon spectroscopy of supersonically cooled NO in the region between the NO+ X 1Σ+, v+=0 and 1 ionization thresholds reveals the n=7–12 members of the ndπ−, v=1 Rydberg series. The n=5 member of the same series is observed below the two-photon ionization threshold by using two-photon resonant, three-photon ionization. The data are analyzed by using multichannel quantum defect theory to extract rotationless quantum defects and to reveal perturbation by the nf, v=1 series. Theoretical two-photon rotational line strengths are in satisfactory agreement with the observed data.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.456363
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  • 10
    Electronic Resource
    Electronic Resource
    Two-photon spectroscopy of Rydberg states of molecular oxygen (1990)
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 93 (1990), S. 3072-3084 
    Details
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: Two-photon resonant, three-photon ionization spectrum of O2X 3Σ−g, v‘=0 is presented in the energy region between the 5s–4d complex and the O+2X 2Π1/2g, v+=0 ionization threshold. The spectrum exhibits a number of new transitions to ns and nd Rydberg states with n=5-9 and v'=0 and 1 as well as transitions to the previously unobserved 5s–4d, v'=3 levels. For a given value of n and v', the observed bands split into two groups separated by approximately the O+2X 2Π1/2g−2Π3/2g spin–orbit splitting. All of the bands show at least some sharp rotational structure, although in most cases this structure is limited to a few lines. In addition, the direct two-photon ionization spectrum of O2X 3Σ−g, v‘=0 is presented in the energy region between the O+2X 2Π1/2g, v+=0 and 1 thresholds; the spectrum shows transitions to Rydberg states with n=8-12 and v'=1. These states are analogous to the v'=0 states observed below the ionization threshold, and they decay by vibrational autoionization into the v+=0 continuum. Taken together, the v'=0 and 1 Rydberg states observed here provide a significant addition to the knowledge of Rydberg series converging to the ground electronic state of O+2.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.458841
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