Detailed Instructions: 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.
See one example below:
Problem: Abstract: Some patients converted from ventricular fibrillation to organized rhythms by defibrillation - trained ambulance technicians(EMT - Ds) will refibrillate before hospital arrival.The authors analyzed 271 cases of ventricular fibrillation managed by EMT - Ds working without paramedic back - up.Of 111 patients initially converted to organized rhythms, 19(17 % ) refibrillated, 11(58 % ) of whom were reconverted to perfusing rhythms, including nine of 11(82 % ) who had spontaneous pulses prior to refibrillation.Among patients initially converted to organized rhythms, hospital admission rates were lower for patients who refibrillated than for patients who did not(53 % versus 76 % , P = NS), although discharge rates were virtually identical(37 % and 35 % , respectively).Scene - to - hospital transport times were not predictively associated with either the frequency of refibrillation or patient outcome.Defibrillation - trained EMTs can effectively manage refibrillation with additional shocks and are not at a significant disadvantage when paramedic back - up is not available.
Solution: Ventricular Fibrillation
Explanation: This term is directly present in the abstract and it is one of the main topic in it. So can be chosen as the medical subject heading.

Problem: Abstract: A retrospective review of the cases of fifteen patients with a three-part fracture of the proximal part of the humerus is presented. Fourteen of the fractures were treated with tension-band wiring and one, with an AO buttress plate. The patients were evaluated for pain, range of motion, strength, and function of the involved shoulder and the radiographic result at an average of fifty-four months after the injury. At follow-up, the shoulders had an average of 126 degrees of active elevation, 29 degrees of active external rotation, 81 degrees of active abduction, and internal rotation to the second lumbar vertebra. The only early complication was failure of fixation in the patient who had been treated with a buttress plate. In two patients, radiographic evidence of avascular necrosis of the humeral head later developed, and one of them required revision to a hemiarthroplasty. In conclusion, we recommend operative treatment for the healthy, active individual who has a three-part fracture of the proximal part of the humerus. We found that the best results with these difficult fractures are obtained using tension-band wiring.
Solution:
Aged