Stimulant continuum

The production of a stimulant continuum that often begins with lesser degrees of insomnia, nervousness, anxiety, hyperactivity, and irritability and then progresses toward more severe agitation,... 

The stimulated Raman emission exhibits a threshold and only a few vibrational lines are observed, corresponding to the lines of highest intensity in the normal Raman spectrum. For observation of the inverse Raman spectrum, both the continuum and the monochromatic stimulating radiation are supplied. There is no threshold and therefore the complete Raman active spectrum can be obtained if the continuum light source has a sufficient spectral bandwidth. 

Using as the background continuum the short-lived spontaneous fluorescence of rhodamine B or 6 G, McLaren and Stoicheff 233) developed this method further to obtain inverse Raman spectra over the range of frequency shifts 300-3500 cm" in liquids and solids in a time of 40 nsec The stimulating monochromatic radiation at 6940 A is provided by a giant-pulse ruby laser. A small part of the main laser beam is frequency-doubled in a KDP-crystal and serves to excite the rhodamine fluorescence, thus ensuring simultaneous irradiation of the sample by both beams. 

The inverse Raman effect was detected in liquids 93> soon after the discovery of the stimulated Raman effect. When a medium is irradiated simultaneously by intense monochromatic light from a giant-pulse laser and by a continuum, sharp absorption lines are observed on the anti-Stokes side of the laser line, and under special conditions also on the Stokes side 94 >. McLaren and Stoicheff 95) used the intense fluorescence from a dye solution excited by frequency-... 

Fig. 8.9. Schematic energy diagrams illustrating recombination mechanisms. The ionization continuum is shown shaded, (a) Spontaneous radiative capture, reaction (8.11) (b) stimulated radiative capture by irradiation with laser light, reaction (8.12) (c) three-body recombination in which the excess energy is removed by an extra positron, reaction (8.14).

We end our contribution to this editorial initiative of the European Academy of Science by recalling the leading role played by the European quantum chemistry community in the development of quantum mechanical (QM) solvation models. We cite, as an example, the first quantum chemistry continuum solvation code developed by Rivail s group in Nancy in 1973 [43], However, this initiative to address the solvation problem from a QM point of view was not entirely out-of-the-blue. It was, on the contrary, a response to the challenges stimulated by a limited number of scientists working in France and in Italy (Paris, Nancy, Pisa), with strong contact, in competition and also in collaboration to each others [44], More than 30 years later, the European quantum chemistry community is still at the forefront in the development of QM continuum solvation models, and we hope that the present contribution can be considered as a testimony of this activity. 

The first panel of Figure 5.12 shows the bichromatic control scenario. The sec panel shows the simplest path to the continuum, consisting of one-photon absorpt of CO]. The subsequent panels show the three-photon process to the contir (absorption of a> followed by stimulated emission and reabsorption of coj, ctc ... 

Figure 5.12 Interfering pathways from Et) to the continuum associated with the scenario in Figure 5.11. The frequency and phase of the lasers are co, and (a) Bichromatic control, (b) One-photon absorption, (c) Three-photon process in which initially unpopulated state Ej) is coupled to the continuum at energy E and interferes with one-photon absorption from state ] ,). (d) Same as in (c) but for a five-photon process. Notice that in processes depicted in (c) and (d) the phase

The spontaneous recombination rate can be enhanced by stimulating the free-bound transition by a laser (CW or pulsed) tuned to the resonance energy for a transition from the continuum to a specific, low lying n level (i.e. a CO2 laser can be used to enhance the population of the n = 11 state) [36]. 

An alternative model recognizes the importance of temporal and spatial domains [54]. Although a continuum of information transfer is appreciated, in this model the cellular response is divided into two temporal phases to illustrate the profound differences in the intracellular events which are responsible for the initial or sustained effects of hormonal stimulation. These temporal phases in turn dictate a spatial compartmentalization to the activation events which mediate the cellular response. As proposed by this alternative model, the segregation of the cellular response into two phases serves as a useful construct within which to approach the complexity underlying All stimulation of its target tissues. 

If the effective temperature of our defined system is less than the universal radiation background temperature of 2.7 K, transitions between the two levels can be observed in absorption. This is the case with interstellar formaldehyde. Alternatively absorption can be observed against the continuum radiation from a nearby bright source. Spontaneous emission will always occur provided the upper of the two levels is populated, and can be observed if the populations are different. There are, in addition, examples of the exceptional situation in which N2 > N the result of this population inversion is that stimulated emission dominates, and maser emission is observed. Interstellar OH and SiO provide diatomic examples of this unusual situation, as also does interstellar H2O we shall describe the results for OH later in this chapter. Departures from local thermodynamic equilibrium are very common, and the concept of temperature in interstellar gas clouds is not simple this is a major part of astrophysics which is, however, beyond the scope of this book. 

The presence of other adverse drug reactions, often involving akathisia or stimulation along a continuum from irritability and agitation to agitated depression and mania, as well as indifference and apathy... 

---