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.

Example Input: Abstract: A retrospective study of patients patch tested between 1968 and 1970 was undertaken and case records of 200 patients with unequivocal positive patch tests were studied for age and sex distribution. There was an overall female preponderance (61%), with 2 peaks of incidence in the 10-20 and 40-50 year age groups in females, but only 1 peak of incidence in the 40-50 year age group in males. There was a steady decline in all sensitivities after the 6th decade of life in both sexes. Nickel sensitivity was more common in females (92%), whereas dichromate sensitivity predominated in males (64%). Of the 200 patients, only 5(2.5%) were atopics, all of whom were females.
Example Output: Adolescence

Example Input: Abstract: We used the model of bilateral cervical vagotomy of adult rabbits to cause respiratory failure characterized by pulmonary edema, decreased lung compliance, and atelectasis. We documented an 18-fold increase in radiolabeled albumin leak from the vascular space into alveolar washes of vagotomy vs. sham-operated rabbits (P less than 0.01). Despite a twofold increase in percent of prelabeled saturated phosphatidylcholine secreted (P less than 0.01), the alveolar wash saturated phosphatidylcholine pool sizes were not different. The minimum surface tensions were 19.6 +/- 2.5 vs. 9.4 +/- 2.2 dyn/cm for alveolar washes from vagotomy and control rabbits, respectively (P less than 0.01). The soluble proteins from alveolar washes inhibited the surface tension lowering properties of natural surfactant, whereas those from the control rabbits did not (P less than 0.01). When vagotomy rabbits in respiratory failure were treated with 50 mg natural surfactant lipid per kilogram arterial blood gas values and compliances improved relative to control rabbits. Vagotomy results in alveolar pulmonary edema, and surfactant dysfunction despite normal surfactant pool sizes and respiratory failure. A surfactant treatment can improve the respiratory failure.
Example Output: Animal

Example Input: Abstract: Two sets of equations have been proposed to estimate the convective or sensible (WCV) and the evaporative or insensible (WEV) respiratory heat exchanges. They are applicable both at sea-level barometric pressure with air breathing (SLA) and in hypo- or hyperbaria in both air (HA) and artificial (HAA) atmospheres. The only environmental parameters required are in SLA: the temperature (TI) and the partial pressure of water vapor of the inspired air (PIH2O); in HA: TI, PIH2O, and the actual barometric pressure (PB); and in HAA: IT, PIH2O, PB, the volumetric mass (rho mix), and the specific heat (cp mix) of the breathed gas mixture. When no physiological data are available the results are expressed in energy units per liter of pulmonary ventilation (WCV/V and WEV/V) in J X dm-3 BTPS. If the ventilation value (V) is known the results are obtained in units of power (W).
Example Output:
Atmospheric Pressure