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 Input:
Few studies investigated the best method for removing stains from different types of resin-based composite restorations and compared them to the more recently introduced nanocomposites. This study compared the effect of four methods for stain removal from composite resins; finishing with Sof-lex disks, using pumice and brush, bleaching with 10% carbamide peroxide and 38% hydrogen peroxide.', 'Twenty disk specimens were prepared. Specimens were immersed in a staining solution for 3weeks. The stained surfaces of five specimens from each RBC material were treated with one of the treatment procedures. Colorimetric measurements were taken using spectrophotometer prior to and after staining, and then repeated after surface treatments. Color difference values were calculated.', "One-way ANOVA indicated significant differences in color change of the three composite resin materials following staining. Filtek Z250 showed the least susceptibility to discoloration followed by Renamel, Filtek Supreme was the material most prone to discoloration. Two-way ANOVA and Tukey's Post Hoc showed that all stain removing procedures except polishing with pumice, were able to return Filtek Z250 to clinically acceptable color difference. While bleaching with 38% carbamide peroxide was not effective with Renamel. Only pumice and 10% carbamide peroxide were able to return Renamel to clinically acceptable color difference.

Ex Output:
Do the effectiveness of four methods for stain removal from direct resin-based composite restorative materials?

Ex Input:
Ductal carcinoma in situ with microinvasion (DCISM) is a rare diagnosis with a good prognosis. Although nodal metastases are uncommon, sentinel lymph node biopsy (SLNB) remains standard care. Volume of disease in invasive breast cancer is associated with SLNB positivity, and, thus we hypothesized that in a large cohort of patients with DCISM, multiple foci of microinvasion might be associated with a higher risk of positive SLNB.', 'Records from a prospective institutional database were reviewed to identify patients with DCISM who underwent SLNB between June 1997 and December 2010. Pathology reports were reviewed for number of microinvasive foci and categorized as 1 focus or 2 foci. Demographic, pathologic, treatment, and outcome data were obtained and analyzed.', 'Of 414 patients, 235 (57 %) had 1 focus of microinvasion and 179 (43 %) had 2 foci. SLNB macrometastases were found in 1.4 %, and micrometastases were found in 6.3 %; neither were significantly different between patients with 1 focus versus 2 foci (p = 1.0). Patients with positive SLNB or 2 foci of microinvasion were more likely to receive chemotherapy. At median 4.9 years (range 0-16.2 years) follow-up, 18 patients, all in the SLNB negative group, had recurred for an overall 5-year recurrence-free proportion of 95.9 %.

Ex Output:
Is extent of microinvasion in ductal carcinoma in situ associated with sentinel lymph node metastases?

Ex Input:
Computed tomography (CT) is an imaging modality involving ionizing radiation. The presence of -H2AX foci after low to moderate ionizing radiation exposure has been demonstrated; however it is unknown whether very low ionizing radiation exposure doses from CT exams can induce -H2AX formation in vivo in young children.', 'To test whether very low ionizing radiation doses from CT exams can induce lymphocytic -H2AX foci (phosphorylated histones used as a marker of DNA damage) formation in vivo in young children.', 'Parents of participating children signed a consent form. Blood samples from three children (ages 3-21months) undergoing CT exams involving very low blood ionizing radiation exposure doses (blood doses of 0.22-1.22mGy) were collected immediately before and 1h post CT exams. Isolated lymphocytes were quantified for -H2AX foci by a technician blinded to the radiation status and dose of the patients. Paired t-tests and regression analyses were performed with significance levels set at P<0.05.', 'We observed a dose-dependent increase in -H2AX foci post-CT exams (P=0.046) among the three children. Ionizing radiation exposure doses led to a linear increase of foci per cell in post-CT samples (102% between lowest and highest dose).

Ex Output:
Are -H2AX foci increased in lymphocytes in vivo in young children 1 h after very low-dose X-irradiation : a pilot study?