Given a passage, construct a question on the basis of the information present in the passage. Construct the question in such a way that (i) it is unambiguous, (ii) it is answerable from the passage, (iii) its answer is unique (iv) it answer uses text phrases from the passage. Avoid creating questions that (i) can't be answered correctly without actually understanding the passage and (ii) uses the same words or phrases given in the passage.

[EX Q]: The aim of this study was to prospectively evaluate the feasibility and potential advantages of freehand single-photon emission computed tomography (fhSPECT) compared with conventional intraoperative localization techniques for sentinel lymph node biopsy (SLNB) in oral cancer.', 'Between November 2012 and February 2014, 23 consecutive patients with clinical T1/T2 oral squamous cell carcinoma and a cN0 neck were recruited. All patients underwent SLNB followed by elective neck dissection (END). All patients received preoperative lymphoscintigraphy. To detect the SLNs intraoperatively, fhSPECT with a combination of conventional acoustic SLN localization and 3-D visual navigation was used.', 'All but one of the SLNs detected by preoperative imaging were successfully mapped intraoperatively by fhSPECT (detection rate 98%), including those in six patients with a tumour in the floor of the mouth. A histopathology analysis revealed positive SLNs in 22% of patients. No further metastases were found in LNs resected during END. SLNB correctly predicted the final LN stage in all patients (accuracy 100%). Additional radioactive LNs, which were not present on preoperative lymphoscintigraphy, were observed in three patients.
[EX A]: Does intraoperative 3-D imaging improve sentinel lymph node biopsy in oral cancer?

[EX Q]: The purpose of this research study was to identify factors that are associated with receiving care in a medical home for children with special health care needs (CSHCN) and to identify how these factors vary among different socioeconomic levels.', 'Data were obtained from the National Survey of Children with Special Health Care Needs, 2000-2002. Access to a medical home was derived using an algorithm. This survey analysis also included demographic characteristics, geographical location of household, severity of condition, and social factors. Multiple logistic regression models were constructed for socioeconomic status (SES) levels defined by federal poverty level (FPL): <133%; 133-199%; 200-299%; > or =300%.', 'Age group was significant in all but the 200-299% of FPL stratum. Severity of condition was significant in all strata. Race was significant in all but the > or =300% stratum. Maternal education was borderline significant in the lowest and highest strata. Insurance type/status was significant in all but the 133-199% of FPL stratum. Geographical location was significant in the lowest and highest strata. The language of the interview was only significant in the lowest stratum. The relationship of the respondent to the child was significant in the middle two strata. The total number of adults in the household was significant in the highest stratum, and the total number of children in the household was significant in the 200-299% of FPL stratum.
[EX A]: Do factors for accessing a medical home vary among CSHCN from different levels of socioeconomic status?

[EX Q]: Oxidative stress is associated with atrial fibrillation (AF). However, little is known about the relationship between serum markers of oxidation and electrical activity in patients with AF.', 'The purpose of this study was to investigate the possible association between serum markers of reactive oxidative metabolism and atrial remodeling in paroxysmal and persistent AF.', 'Derivatives of reactive oxidative metabolites (DROM), an index of oxidative stress, were measured in 306 consecutive patients with AF (225 paroxysmal, 81 persistent) undergoing radiofrequency (RF) catheter ablation. Filtered P-wave duration by P-wave signal-averaged ECG and levels of high-sensitivity C-reactive protein (CRP) as an inflammatory marker also were measured.', 'Patients were followed up for 1.2 +/- 0.8 years. DROM levels in patients with persistent AF were significantly higher than in patients with paroxysmal AF (341.6 +/- 85.5 Carratelli [Carr] units vs 305.0 +/- 77.7 Carr units, P <.001). DROM levels showed a tighter, positive correlation with filtered P-wave duration in persistent AF patients (r = 0.56, P <.001) than in all AF patients (r = 0.13, P <.05). DROM levels also showed a weaker but significant correlation with high-sensitivity CRP in patients with AF. Kaplan-Meier analysis revealed that the highest quartile of basal DROM levels exhibited a significantly higher AF recurrence rate after RF catheter ablation in patients with paroxysmal AF (P <.01).
[EX A]:
Are reactive oxidative metabolites associated with atrial conduction disturbance in patients with atrial fibrillation?