Given an abstract, generate a keyword (a noun phrase) that best describes the focus or contribution of the paper. Such keywords can be directly from the given abstract or outside it.

[EX Q]: Abstract: Respiration in rapid-eye-movement sleep (REMS) is known to be highly variable. The purpose of this study was to investigate the source of this variability and to determine which ordering principles remained operative in REM sleep. In unrestrained, naturally sleeping cats we recorded the electroencephalogram, electrooculogram, neck electromyogram, and diaphragmatic electromyogram (EMG) and computed its moving average (MAdi). As a reference, we first examined MAdi during "tonic" REMS, since breathing is fairly regular in this state. "Control" ranges for peak amplitude (PEMG), inspiratory time (TI), duration of postinspiratory inspiratory activity, expiratory time, and the calculated inspiratory slope (PEMG/TI) were determined by overlaying individual breath traces of the time course of MAdi during tonic REMS to form a composite tracing. Next, the time course of the EMG during individual breaths in slow-wave sleep (SWS) and a complete period of consecutive breaths in REMS (both tonic and phasic) were compared with this tonic REMS composite. The number of eye movements per breath was tabulated as an index of phasic activity. The inspiratory slopes during SWS and tonic REMS were similar. However, during phasic REMS, many breaths displayed either increases (excitation) or decreases (inhibition) in slope compared with the "typical" breaths seen in tonic REMS. The occurrence of these altered slopes increased with the frequency of phasic events. TI was inversely related to the slope of the EMG, which tended to minimize changes in PEMG.(ABSTRACT TRUNCATED AT 250 WORDS)
[EX A]: Animal

[EX Q]: Abstract: Twenty-seven patients with squamous cell carcinoma of the mobile tongue and floor of the mouth were treated with external beam and interstitial radiation. Good prognostic factors were T1N0, T2N0, superficial tumors, tumor shrinkage by 75% with external beam, and no apparent tumor clinically 2 months after treatment. On the other hand, T3N0, T1-3N1, and deeply necrotic tumors had a poor prognosis. We recommend using a flexible afterloading system to implant the initial local tumor volume (not just the residual nidus) that does not exceed 45 cm3. The minimum (reference) dose was prescribed to a surface 1/2 cm beyond the most peripheral rim of radioactive sources. For acceptable local control and complication rates, our suggested minimum (reference) doses are less than or equal to 7,500 rads for T1 (or a time-dose-fractionation [TDF] of 131-140), less than or equal to 8,000 rads for T2 (TDF of 131-140), and probably less than 8,500 rads for T3 (TDF of less than or equal to 150). These guidelines should be considered preliminary.
[EX A]: Brachytherapy

[EX Q]: Abstract: Concentrations of catecholamines in vitreous fluid and urine in guinea pigs dying of cold and the effects of freezing and autolysis on these parameters were studied. The analysis was performed by high performance liquid chromatography with electrochemical detection. Noradrenaline (NA) concentration in vitreous fluid was more than 20 times higher in the cold exposed animals than in controls (44.2 +/- 9.2 versus 2.0 +/- 1.0 ng/mL). Autolysis alone caused an increase to 33.5 +/- 7.7 ng/mL, and freezing alone to 13.4 +/- 5.3 ng/mL. The highest values were in the group with exposure, freezing, and autolysis. Adrenaline (A) concentration in the vitreous fluid increased fourfold (3.9 +/- 1.5 versus 0.7 +/- 0.5 ng/mL) in cold exposure and twofold as a result of autolysis. Dopamine (DA) concentration in vitreous fluid was elevated only in the group with exposure, freezing, and autolysis. The increase of NA concentration in urine was fivefold during the whole exposure (from 19.4 +/- 6.9 to 109 +/- 57.3 ng/mL), but A was increased by twentyfold (from 10 +/- 5.1 to 213.2 +/- 168.7 ng/mL), whereas DA concentration did not change. The increase of average excretion of NA to urine was eightfold during the first 6 h of exposure, and that of A tenfold. According to the present results, elevated concentrations of catecholamines in the vitreous fluid and urine can be used as a diagnostic aid for hypothermia death. Concerning the values of noradrenaline in the vitreous, the increase as a result of autolysis must be taken in account when interpreting the results.
[EX A]:
Animal

