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  • 1
    Electronic Resource
    Electronic Resource
    Properties of ion exchanged planar and channel optical waveguides fabricated in Cu doped KTiOPO4 substrates (1997)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 71 (1997), S. 2737-2739 
    Details
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Planar and channel optical waveguides were fabricated in Cu doped KTiOPO4 (KTP) substrates using Rb+:K+ ion exchange process and annealing process. The effective refractive indices were measured using the m-line method and the refractive index profiles of these waveguides were calculated using the inverse WKB method. For waveguides in Cu:KTP substrates the difference of diffusion depth d and index change Δn at the z− and z+ surfaces can hardly be observed. This observation is different from KTP. Compared with undoped KTP substrates the diffusion depth d at the z− surfaces is larger, whereas the index change Δn is smaller. At the z+ surfaces both d and Δn are larger. The light induced effective index changes in Cu doped KTP channel waveguides were measured at 0.476, 0.488, 0.514, 0.6328, and 0.83 μm wavelengths. No changes were observed at the power flow of 1×108 W/m2, revealing that Cu ion does not play an important role in photorefractive effect of KTP crystals. © 1997 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.120122
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  • 2
    Electronic Resource
    Electronic Resource
    Human Carbonic Anhydrases and Carbonic Anhydrase Deficiencies (1995)
    Palo Alto, Calif. : Annual Reviews
    Annual Review of Biochemistry 64 (1995), S. 375-401 
    Details
    ISSN: 0066-4154
    Source: Annual Reviews Electronic Back Volume Collection 1932-2001ff
    Topics: Chemistry and Pharmacology , Biology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1146/annurev.bi.64.070195.002111
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  • 3
    Electronic Resource
    Electronic Resource
    Physical origin of the high reactivity of subsurface hydrogen in catalytic hydrogenation (1999)
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 111 (1999), S. 1343-1345 
    Details
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: In the catalytic hydrogenation of hydrocarbons, subsurface hydrogen is known experimentally to be much more reactive than surface hydrogen. We use density functional theory to identify low-energy pathways for the hydrogenation of methyl adsorbed on Ni(111) by surface and subsurface hydrogen. The metastability of subsurface hydrogen with respect to chemisorbed hydrogen is mainly responsible for the low activation barrier for subsurface reactions. © 1999 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.479392
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  • 4
    Electronic Resource
    Electronic Resource
    Ab initio diffusional potential energy surface for CO chemisorption on Pd{110} at high coverage: Coupled translation and rotation (1997)
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 107 (1997), S. 8103-8109 
    Details
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: The ground state potential energy surface for CO chemisorption across Pd{110} has been calculated using density functional theory with gradient corrections at monolayer coverage. The most stable site corresponds well with the experimental adsorption heat, and it is found that the strength of binding to sites is in the following order: pseudo-short-bridge〉atop〉long-bridge〉hollow. Pathways and transition states for CO surface diffusion, involving a correlation between translation and orientation, are proposed and discussed. © 1997 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.475073
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  • 5
    Electronic Resource
    Electronic Resource
    Site symmetry dependence of repulsive interactions between chemisorbed oxygen atoms on Pt{100}-(1×1) (1997)
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 106 (1997), S. 1210-1215 
    Details
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: Ab initio total energy calculations using density functional theory with the generalized gradient approximation have been performed for the chemisorption of oxygen atoms on a Pt{100}-(1×1) slab. Binding energies for the adsorption of oxygen on different high-symmetry sites are presented. The bridge site is the most stable at a coverage of 0.5 ML, followed by the fourfold hollow site. The atop site is the least stable. This finding is rationalized by analyzing the "local structures" formed upon oxygen chemisorption. The binding energies and heats of adsorption at different oxygen coverages show that pairwise repulsive interactions are considerably stronger between oxygen atoms occupying fourfold sites than those occupying bridge sites. Analysis of the partial charge densities associated with Bloch states demonstrates that the O–Pt bond is considerably more localized at the bridge site. These effects cause a sharp drop in the heats of adsorption for oxygen on hollow sites when the coverage is increased from 0.25 to 0.5 ML. Mixing between oxygen p orbitals and Pt d orbitals can be observed over the whole metal d-band energy range.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.473217
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  • 6
    Electronic Resource
    Electronic Resource
    Theoretical analysis of optimal quasi-phase matched second harmonic generation waveguide structure in LiTaO3 substrates (1999)
    Springer
    Optical and quantum electronics 31 (1999), S. 337-349 
    Details
    ISSN: 1572-817X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Electrical Engineering, Measurement and Control Technology , Physics
    Notes: Abstract Based on the QPM structure and the coupled-mode theory, the maximum SHG conversion efficiency of QPM-SHG waveguides in LiTaO3 substrates is analyzed by optimizing the mode confinement and the mode overlap factors. For TM00(ω)-to-TM00(2ω) conversion with a non-square shaped domain inversion QPM structure, the mode confinement and mode overlap factor are dependent not only on the optical field distribution for the fundamental and the SH waves in the waveguide, but also on the domain inversion shape. With the assumption that the refractive index profile of an annealed, proton exchanged LiTaO3 channel waveguide is an exponential decay function in the depth direction, and a Gaussian function in the width direction, the analytical expression of the optical field distribution for the lowest order mode can be obtained. By considering both a non-Gaussian field distribution and a non-square shaped domain inversion structure, the theoretical values for achieving the optimal QPM-SHG waveguide structure are determined.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1006988507435
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  • 7
    Electronic Resource
    Electronic Resource
    Postextubation laryngeal edema in adults Risk factor evaluation and prevention by hydrocortisone (1996)
    Springer
    Intensive care medicine 22 (1996), S. 933-936 
    Details
    ISSN: 1432-1238
    Keywords: Key words Endotracheal tube ; Complications ; Postextubation ; Stridor ; Laryngeal edema ; Corticosteroids
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Objective: To evaluate the risk factors for postextubation laryngeal stridor and its prevention by hydrocortisone in adult patients. Design: Prospective, randomized, double-blind, placebo controlled study. Setting: Medical and surgical ICU of a tertiary teaching hospital. Patients: 77 consecutive patients of both sexes, who had undergone tracheal intubation for more than 24 h and fulfilled the weaning criteria, were eligible for the study. Patients were excluded if they were less than 15 years of age, had a disease or the surgery of the throat, or had been extubated during the current hospitalization. Intervention: The control group received placebo (normal saline 3cc) and the experimental group received hydrocortisone 100 mg by intravenous infusion 60 min before extubation. Main outcome measures: Patients were observed 24 h after extubation for symptoms or signs of laryngeal edema or stridor: prolonged inspiration with accessory usage of respiratory muscles or crowing sound with inspiration or reintubation. Results: The overall incidence of postextubation stridor was 22% (17/77). Only one patient (1%), who belonged to the control group, needed reintubation. 39% of female patients and 17% of male patients developed stridor. The relative risk of females developing this complication was 2.29. 7/39 of the hydrocortisone group and 10/38 of patients in the control group developed postextubation stridor. Conclusions: Hydrocortisone did not significantly reduce the incidence of postextubation laryngeal edema or stridor. From the risk factors evaluated, we were unable to demonstrate a statistical correlation between postextubation stidor and the duration of the intubation, the patient‘s age, the internal diameter of the endotracheal tube, or the route of intubation. However, female patients were more likely to develop this complication.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s001340050189
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  • 8
    Electronic Resource
    Electronic Resource
    Postextubation laryngeal edema in adults risk factor evaluation and prevention by hydrocortisone (1996)
    Springer
    Intensive care medicine 22 (1996), S. 933-936 
    Details
    ISSN: 1432-1238
    Keywords: Endotracheal tube ; Complications ; Postextubation ; Stridor ; Laryngeal edema ; Corticosteroids
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Objective To evaluate the risk factors for postextubation laryngeal stridor and its prevention by hydrocortisone in adult patients.Design: Prospective, randomized, double-blind, placebo controlled study. Setting Medical and surgical ICU of a tertiary teaching hospital. Patients 77 consecutive patients of both sexes, who had undergone tracheal intubation for more than 24 h and fulfilled the weaning criteria, were eligible for the study. Patients were excluded if they were less than 15 years of age, had a disease or the surgery of the throat, or had been extubated during the current hospitalization. Intervention The control group received placebo (normal saline 3 cc) and the experimental group received hydrocortisone 100 mg by intravenous infusion 60 min before extubation. Main outcome measures Patients were observed 24 h after extubation for symptoms or signs of laryngeal edema or stridor: prolonged inspiration with accessory usage of respiratory muscles or crowing sound with inspiration or reintubation. Results The overall incidence of postextubation stridor was 22% (17/77). Only one patient (1%), who belonged to the control group, needed reintubation. 39% of female patients and 17% of male patients developed stridor. The relative risk of females developing this complication was 2.29. 7/39 of the hydrocortisone group and 10/38 of patients in the control group developed postextubation stridor.Conclusions: Hydrocortisone did not significantly reduce the incidence of postextubation laryngeal edema or stridor. From the risk factors evaluated, we were unable to demonstrate a statistical correlation between postextubation stidor and the duration of the intubation, the patient's age, the internal diameter of the endotracheal tube, or the route of intubation. However, female patients were more likely to develop this complication.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02044118
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  • 9
    Electronic Resource
    Electronic Resource
    Two selective 5-HT1A receptor antagonists, WAY-100 635 and NDL-249, stimulate locomotion in rats acclimatised to their environment and alter their behaviour: a behavioural analysis (1998)
    Springer
    Psychopharmacology 139 (1998), S. 300-310 
    Details
    ISSN: 1432-2072
    Keywords: Key words Locomotion ; Rearing ; Activity ; NDL-249 ; WAY-100 635 ; 8-OH-DPAT ; 5-HT1A receptor ; Grooming ; Vacuous chewing ; Observation ; 5-HT1A receptor agonist ; 5-HT1A receptor antagonist ; DA-5-HT interaction ; SCH-23390 ; Raclopride
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The aim was to study firstly, the motor effects of a new 5-HT1A antagonist, NDL-249 [(R)-3-(N-cyclopentyl-N-propylamino)-8-fluoro-3,4-dihydro-2H-1-benzopyran-5-carboxamide hydrochloride] and of the reference 5-HT1A antagonist WAY-100 635 [N-(2-(1-(4-(2-methoxyphenyl)piperazinyl))ethyl)-N-(2-pyridinyl) cyclohexanecarboxamide trihydrochloride], in comparison to the 5-HT1A agonist (±)-8-OH-DPAT [(8-hydroxy-2-(di-N-propylamino) tetralin, hereafter 8-OH-DPAT], in rats acclimatised to the automated activity cages; secondly, to study whether the behavioural effects of NDL-249 and 8-OH-DPAT are sensitive to the 5-HT depleting effects of p-chlorophenylalanine (PCPA); thirdly, to characterise the nature of the antagonist-induced activation seen in the automatic activity cages with the aid of a behavioural observation analysis; fourthly, to examine the interaction between the 5-HT1Areceptors mediating the behavioural effects and dopamine (DA) receptors. NDL-249 was found to bind in vitro to rat hippocampal 5-HT1A receptors with high affinity and selectivity. In second messenger studies, it was devoid of agonist-like effects. In the locomotor activity studies, each antagonist significantly increased the incidence of horizontal activity, peripheral activity and rearing. 8-OH-DPAT, while significantly increasing peripheral and horizontal activities, decreased the incidence of rearing. PCPA blocked the motor effects of NDL-249 but did not affect those of 8-OH-DPAT. Observational analyses indicated that NDL-249 induced significant increases at one or more doses in sniffing, rearing and locomotion together with a significant reduction in stillness. WAY-100 635 significantly increased the incidence of rearing, intense grooming and vacuous chewing. The significant increases in sniffing, grooming and intense grooming and the significant decrease in stillness induced by the DA D1 agonist, SK&F 38393 [(±)-1-phenyl-2,3,4,5-tetrahydro-(1H)-3-benzazepine-7,8-diol hydrochloride], were not altered by concomitant pre-treatment with NDL-249. Pre-treatment of rats with either the DA D1 antagonist SCH-23390 (2,3,4,5-tetrahydro-3-methyl-5-phenyl-1H-3-benzazepin-7-ol) or the DA D2 antagonist, raclopride, blocked the reduced stillness and increased sniffing and rearing induced by NDL-249. In conclusion, 5-HT1A antagonists including the new selective antagonist, NDL-249, induce mild behavioural activation in rats, which is mediated probably indirectly via DA systems.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002130050721
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  • 10
    Electronic Resource
    Electronic Resource
    Mechanistic studies on the conjugation of methyl isocyanate with N-acetyl-cysteine in rats (1996)
    Springer
    Journal of radioanalytical and nuclear chemistry 206 (1996), S. 305-310 
    Details
    ISSN: 1588-2780
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Energy, Environment Protection, Nuclear Power Engineering
    Notes: Abstract In order to investigate the utility of selected thiols as scavengers of MIC, we first assessed the chemical stability of SMG, AMCC and SMC by measuring their rates of reaction in vitro with thiophan. The inital rates of carbamoylation of thiorphan (0.5 mM) by the above conjugates (0.5 mM) in aqueous buffer at pH 7.4 and 37°C were 2.51, 0.76 and 8.47 μmol L−1 min−1, respectively, indicating that the mercapturate AMCC was the most stable of the three MIC conjugates. In light of these results, studies were conducted to examine the effect of pretreatment withN-acetyl-l-cysteine (l-NAC; 500 mg kg−1, i.p.) on the urinary elimination of AMCC in rats dosed with MIC (15 mg kg−1, i.p.). In separate experiments, groups of rats were pretreated with eitherN-acetyl-d-cysteine (d-NAC) orN-trideuteroacetyl-l-cysteine (d3-l-NAC) in order to explore the mechanism by which MIC undergoes conjugation to AMCCin vivo. The results indicated that exogenous NAC effectively enhances the urinary excretion of MIC in the form of AMCC, and that it does so largely by direct conjugation with the isocyanate, rather thanvia biosynthesis to GSH.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02039657
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