TASK DEFINITION: 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.
PROBLEM: Autonomic dysfunction has previously been described in primary biliary cirrhosis patients. In nonhepatic diseases, fatigue is associated with autonomic dysfunction and impaired baroreflex sensitivity. Here, we investigate the prevalence of autonomic dysfunction using highly sensitive detection modalities and its relationship with fatigue in both noncirrhotic and cirrhotic primary biliary cirrhosis patients.', 'Autonomic reflex tests were performed, using continuous blood pressure and electrocardiograph measurement in 47 primary biliary cirrhosis patients and age and sex-matched controls. Fatigue was measured using the primary biliary cirrhosis-40.', 'In all, 100% of precirrhotic and 81% of cirrhotic primary biliary cirrhosis patients exhibited autonomic dysfunction. Valsalva ratio and 30 : 15 ratio (measures of parasympathetic autonomic dysfunction) were significantly lower in primary biliary cirrhosis patients than in controls (valsalva ratio: 1.42 vs. 1.57; P=0.01, 30 : 15: 1.1 vs. 1.2; P=0.01). Blood pressure drop on standing (sympathetic autonomic dysfunction) was greater in the primary biliary cirrhosis group (31+/-22 vs. 23+/-15 mmHg; P=0.03). Valsalva phase IV size was similar between primary biliary cirrhosis patients and controls, however, time to phase IV was significantly longer (P=0.01), suggesting adrenergic failure. Increasing fatigue was associated with impaired baroreflex sensitivity and an earlier, bigger phase IV (sympathetic overactivity). No significant differences were seen, between cirrhotic and noncirrhotic patients.

SOLUTION: Does autonomic dysfunction in primary biliary cirrhosis correlate with fatigue severity?

PROBLEM: To investigate the incidence of acute kidney injury after cardiac surgery and its association with mortality in a patient population receiving ibuprofen and gentamicin perioperatively.', 'Retrospective study with Cox regression analysis to control for possible preoperative, intraoperative and postoperative confounders.', 'University hospital-based single-center study.', 'All patients who underwent coronary artery bypass grafting ± valve surgery during 2012.', 'None.', 'Acute surgery within 24 hours of coronary angiography, previous nephrectomy, preoperative sCr >2.26 mg/dL and selective cerebral perfusion during cardiopulmonary bypass were used as exclusion criteria. Acute kidney injury was defined, using the Acute Kidney Injury Network (AKIN) criteria. Six hundred eight patients were included in the study. Mean age was 68.2 ± 9.7 years, and 81% were males. Acute kidney injury was seen in 28.1% of the patients. Overall mortality at one year was 7% and 3% in the no-AKI group. At one year, mortality was 15% in patients with AKIN stage 1 and AKIN stage 2 compared to 70% in AKIN stage 3. A hazard ratio of 2.34 (95% CI: 1.21-4.51, p = 0.011) and 5.62 (95% CI: 2.42-13.06), p<0.0001) were found for AKIN stage 1 and 2/3 combined, respectively.

SOLUTION: Is acute kidney injury independently associated with higher mortality after cardiac surgery?

PROBLEM: Mass spectrometry-based proteomics experiments generate spectra that are rich in information. Often only a fraction of this information is used for peptide/protein identification, whereas a significant proportion of the peaks in a spectrum remain unexplained. In this paper we explore how a specific class of data mining techniques termed "frequent itemset mining" can be employed to discover patterns in the unassigned data, and how such patterns can help us interpret the origin of the unexpected/unexplained peaks.', 'First a model is proposed that describes the origin of the observed peaks in a mass spectrum. For this purpose we use the classical correlative database search algorithm. Peaks that support a positive identification of the spectrum are termed explained peaks. Next, frequent itemset mining techniques are introduced to infer which unexplained peaks are associated in a spectrum. The method is validated on two types of experimental proteomic data. First, peptide mass fingerprint data is analyzed to explain the unassigned peaks in a full scan mass spectrum. Interestingly, a large numbers of experimental spectra reveals several highly frequent unexplained masses, and pattern mining on these frequent masses demonstrates that subsets of these peaks frequently co-occur. Further evaluation shows that several of these co-occurring peaks indeed have a known common origin, and other patterns are promising hypothesis generators for further analysis. Second, the proposed methodology is validated on tandem mass spectrometral data using a public spectral library, where associations within the mass differences of unassigned peaks and peptide modifications are explored. The investigation of the found patterns illustrates that meaningful patterns can be discovered that can be explained by features of the employed technology and found modifications.

SOLUTION:
Does unravelling associations between unassigned mass spectrometry peak with frequent itemset mining techniques?