Given a passage with a context and an answer, 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]: Context: To study the effect of Cleistocalyx nervosum extract (CE) on diethylnitrosamine (DEN) and phenobarbital (PB) induced oxidative stress in early stages of rat hepatocarcinogenesis.', 'Male Wistar rats were divided into 4 groups, with Group 1 as a negative control and Group 2 was a positive control receiving DEN injections once a week and PB in drinking water for 6 weeks. Two weeks before DEN initiation and PB treatment, Groups 3 and 4, were fed with 500 and 1000 mg/kg of CEs, respectively, for 8 weeks.', 'A number of GST-P-positive foci, preneoplastic lesions, in the liver were markedly increased in carcinogen administered rats, but was comparatively decreased in rats treated with 1000 mg/kg of CE. The CE reduced malondialdehyde in serum and in the livers of rats treated with DEN and PB. Moreover, CE significantly increased the activities of glutathione peroxidase and catalase in rat liver.
Answer: CE appeared to exert its chemopreventive effects by modulating antioxidant status during DEN and PB induced early stages of hepatocarcinogenesis in rats.
[EX A]: Does cleistocalyx nervosum extract ameliorate chemical-induced oxidative stress in early stages of rat hepatocarcinogenesis?

[EX Q]: Context: To chemically identify and quantify glucose degradation products in heat sterilized fluids for peritoneal dialysis.', 'Three different brands of commercial PD-fluids and one laboratory made fluid, sterilized either by heat or filtration, were investigated for the presence of aldehydes.', 'Aldehydes were identified and quantified using high performance liquid chromatography and gas chromatography.', 'The tested brands of heat sterilized PD-fluids were found to contain several different aldehydes while the sterile filtered PD-fluid contained none. The highest concentrations in commercial PD-fluids of these aldehydes were: acetaldehyde (420 microns), glyoxal (14 microns), methylglyoxal (12 microns) and formaldehyde (11 microns). Valeraldehyde was also identified but not quantified. The presence of 5-HMF (15 microns) and 2-furaldehyde (2 microns), which has been identified by others, was confirmed.
Answer: The heat sterilization of commercial PD-fluids gives rise to several aldehydes which may contribute to adverse effects of PD-fluids on patients.
[EX A]: Does heat sterilization of fluids for peritoneal dialysis give rise to aldehydes?

[EX Q]: Context: The aim of this study was to assess the effect of the implementation of evidence-based guidelines and subsequent feedback to surgeons in the management of acute pancreatitis.', 'An evidence-based Pancreatitis Proforma was developed. Data were prospectively recorded (01/06/2005-30/09/2007). Audit feedback (AFB) was performed at 9 months. A final analysis was performed comparing outcomes pre- and post-audit feedback.', '372 patients were included. Median age (range) was 57 (12-96) years. 168 (45.2%) patients were admitted pre-AFB. Post-AFB, there was a significant increase in the number of patients whose diagnosis was made within 48 hours (135/168 (80.4%) vs 189/204 (92.6%), p<0.001) and who underwent definitive treatment for mild biliary pancreatitis (33/61 (54.1%) vs 56/70 (80.0%), p=0.002). Post-AFB there was also a significant reduction in the number of computed tomography (CT) scans performed for patients with mild acute pancreatitis (23/85 (27.1%) vs 13/99 (13.1%), p=0.018). Mortality (9/168 (5.4%) vs 3/204 (1.4%), p=0.040) also decreased. On multivariate analysis, AFB was an independent factor for change in the use of CT scans (p=0.015) and management of patients with mild biliary pancreatitis (p=0.039).
Answer: For evidence-based guidelines to be effective, feedback to surgeons is necessary.
[EX A]:
Is closing the audit loop necessary to achieve compliance with evidence-based guidelines in the management of acute pancreatitis?