You will be given a definition of a task first, then an example. Follow the example to solve a new instance of the task.
Given an abstract, indicate which of the provided candidate titles (Option1 and Option2) best describes it (respond with the text of the title, not option1/2).

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.
Which is the apt title for the abstract? option1: Refibrillation managed by EMT-Ds option2: Maintenance of compliance in a small diameter arterial prosthesis.
Solution: Refibrillation managed by EMT-Ds
Why? The abstract is about refibrillation and it is also mentioned in the abstract that it is managed by EMT-Ds. So it is an apt title.

New input: Abstract: Human decompression sickness is presumed to result from excess inert gas in the body when ambient pressure is reduced. Although the most common symptom is pain in the skeletal joints, no direct study of nitrogen exchange in this region has been undertaken. For this study, nitrogen tagged with radioactive 13N was prepared in a linear accelerator. Nine human subjects rebreathed this gas from a closed circuit for 30 min, then completed a 40- to 100-min washout period breathing room air. The isotope 13N was monitored continuously in the subject's knee during the entire period using positron detectors. After correction for isotope decay (half-life = 9.96 min), the concentration in most knees continued to rise for at least 30 min into the washout period. Various causes of this unexpected result are discussed, the most likely of which is an extensive redistribution of gas within avascular knee tissues.
Which is the apt title for the abstract? option1: Nitrogen gas exchange in the human knee. option2: Patient and house officer attitudes on physician attire and etiquette.
Solution:
Nitrogen gas exchange in the human knee.