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Notes: Zusammenfassung Prontosil solubile ist für sich allein imstande, dieunbekapselte Sarcina tetragena zur Phagocytose vorzubereiten. Diese Wirkung tritt gegenüber derbekapselten Sarcina tetragena nicht auf, auch dann nicht, wenn Prontosil zu aktivem Meerschweinchenserum zugesetzt wird. Die Kapsel bildet demnach auch für die dem Prontosil oder dem Serum mit Prontosilzusatz exponierte Sarcina tetragena einen Schutz gegen die Phagocytose.

Notes: Abstract Objective: To compare the new mode of ventilatory support, which we call automatic tube compensation (ATC), with inspiratory pressure support (IPS) with respect to perception of respiratory comfort. ATC unloads the resistance of the endotracheal tube (ETT) in inspiration by increasing the airway pressure, and in expiration by decreasing the airway pressure according to the non-linear pressure-flow relationship of the ETT. Design: Prospective randomized single blind cross-over study. Setting: Laboratory of the Section of Experimental Anaesthesiology (Clinic of Anaesthesiology; University of Freiburg). Subjects: Ten healthy volunteers. Interventions: The subjects breathed spontaneously through an ETT of 7.5 mm i. d. Three different ventilatory modes, each with a PEEP of 5 cmH2O, were presented in random order using the Dräger Evita 2 ventilator with prototype software: (1) IPS (10 cmH2O, 1 s ramp), (2) inspiratory ATC (ATC-in), (3) inspiratory and expiratory ATC (ATC-in-ex). Measurements and main results: Immediately following a mode transition, the volunteers answered with a hand sign to show how they perceived the new mode compared with the preceding mode in terms of gain or loss in subjective respiratory comfort: “better”, “unchanged” or “worse”. Inspiration and expiration were investigated separately analyzing 60 mode transitions each. Flow rates were continuously measured. The transition from IPS to either type of ATC was perceived positively, i. e. as increased comfort, whereas the opposite transition from ATC to IPS was perceived negatively, i. e. as decreased comfort. The transition from ATC-in to ATC-in-ex was perceived positively whereas the opposite mode transition was perceived negatively in expiration only. Tidal volume was 1220 ± 404 ml during IPS and 1017 ± 362 ml during ATC. The inspiratory peak flow rate was 959 ± 78 ml/s during IPS and 1048 ± 197 ml/s during ATC. Conclusions: ATC provides an increase in respiratory comfort compared with IPS. The predominant cause for respiratory discomfort in the IPS mode seems to be lung over-inflation.

Notes: A study has been made of the vibrational energy flow mechanisms and time scales pertaining to the overtone stretch excitations of methyl and acetylenic CH stretches in propyne. Classical trajectories are used to interpret the experimental data for the overtone linewidths, as well as to analyze the role that individual modes play in determining energy flow. The full anharmonic potential surface for these calculations, including all modes, has been developed from spectroscopic and structural information, including the linewidth data. The principal results are: (1) The trajectory calculations show a localization transition, corresponding to a switch over from normal-mode behavior for CH3 excitations up to v≅3 to a local-mode CH excitation within the CH3 moiety for excitations of v(approximately-greater-than)6, with transition behavior for v=4,5. (2) The acetylenic CH shows local-mode behavior from v=1. Extremely long lifetimes are found for the excitations of this mode, and the trajectories indicate that the experimental width is predominantly rotational. (3) The rocking and deformation modes are dominant receiving modes in the relaxation of the methyl stretch. (4) A shorter lifetime is calculated for the v=6 vs the v=5 or v=7 overtones of the methyl C–H stretch. Experimental results are qualitatively consistent with this prediction. The origin of this shorter lifetime is a band of resonances between the stretch excitation and combinations of rocking, deformation, and pseudorotation modes. (5) CH3 internal rotation figures importantly in the relaxation of some levels (v=5, 8 of CH3) where it "closes the energy gap'' for achieving resonant energy transfer. (6) For v=8 of the methyl CH, some direct energy transfer to both C–C(Triple Bond)C stretching modes is seen. The switching on of the stretches as receiving modes is a consequence of sufficiently strong interactions between the excited H and the C–C(Triple Bond)C chain, which take place at these high vibrational energies. (7) Evidence is found for long distance "through-space'' energy transfer due to long-range dipole–dipole forces. This transfer occurs from the acetylenic to the methyl CH stretches. This result is illustrated for the v=2 excitation of the acetylenichydrogen, and constitutes a direct demonstration of intramolecular long-distance, through-space v–v energy transfer. These results demonstrate the potential importance of large amplitude modes such as rocking and deformation as initial receiving modes for vibrational energy from excited CH overtones. On the time scale probed here (∼1 ps), despite the availability of many degrees of freedom, the transfer process is dominated by specific energy transfer channels and by the specific behavior of individual modes, rather than by statistical considerations, which will certainly prevail on longer time scales.

Notes: The vibrational overtone spectra of the acetylenic and methyl C–H stretches of propyne were obtained for the v=1 to v=6 and v=1 to v=7 levels, respectively. Propyne-dl was also studied and the methyl C–H stretching overtones were measured from v=1 to the v=7 level. The C–D stretch was observed only in the fundamental and first overtone regions. Lower level overtones were obtained by standard infrared techniques, while higher absorptions (〉12 000 cm−1) were obtained by intracavity dye laser photoacoustic spectroscopy. The C–H stretches in both molecules were analyzed in terms of the local-mode model, and harmonic frequencies (ωi) and anharmonicities (Xii) were calculated. In propyne these values were (acetylenic C–H stretch) ω1=3384±5 cm−1 and X11=−50±1 cm−1 and (methyl C–H stretch) ωm =3037±5 cm−1 and Xmm =−65±2 cm−1. In propyne-dl the methyl C–H stretch parameters were ωm =3034±5 cm−1 and Xmm =−64±2 cm−1. For propyne, a hot band (ν9→ν9+vν1) accompanying the acetylenic C–H stretch was observed for v=1–6 and the anharmonic interaction constant (X19=−23±7 cm−1) was calculated. A crossover from normal- to local-mode behavior has been observed for the methyl C–H stretches in propyne and propyne-dl at the v=3 and 4 levels. Below v=3 the symmetric and antisymmetric methyl C–H stretches are designated by the usual normal-mode notation (ν2 and ν6 in propyne; ν1 and ν6 in propyne-dl), while for v≥3 the single observed band is designated as a "methyl'' C–H stretch, vνm. Peak absorption cross sections have been measured for Δv1=1–5, Δvm =3–5, Δv2=1 and 2, and the parallel component of 2ν6 in propyne, and for Δv2=1 and 2, Δv1=1 and 2, Δvm =3 and 4, and the parallel component of 2ν6 in propyne-dl. During the course of this work the spectral constants of 3,3,3-trifluoropropyne were redetermined. The harmonic frequency ω1 is 3376±6 cm−1, the anharmonicityX11 is −49±1 cm−1, and the anharmonic interaction constant X17 is −17±6 cm−1.