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.

Input: Consider 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 3\xa0weeks. 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.

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


Input: Consider Input: Vascular endothelial growth factor (VEGF) is a multifunctional cytokine that plays a role in angiogenesis and microvascular permeability. This study was conducted to determine whether common sequence variation in the VEGFA gene plays a role in the development of diabetic retinopathy (DR).', 'Five hundred fifty-four subjects with diabetes mellitus (DM) including 190 type 1 DM (T1DM) and 364 type 2 DM (T2DM) were recruited. The study group consisted of 235 participants without DR, 158 with nonproliferative DR (NPDR), 132 with proliferative DR (PDR), and 93 with clinically significant macular edema (CSME). Blinding DR was defined as severe NPDR, PDR, or CSME. Fifteen VEGFA tag single-nucleotide polymorphisms (SNPs) were genotyped in all subjects and tested for association with blinding DR.', 'Multiple tag SNPs in the VEGFA gene were associated with blinding DR. After controlling for sex, HbA1c, and duration of disease, in T1DM, the AA genotype of rs699946 (P = 0.007, odds ratio [OR], 4.1; 95% confidence interval [CI], 1.5-11.4) and the GG genotype of rs833068 (P = 0.017, OR, 3.1; 95% CI, 1.3-7.2) were most significantly associated. In T2DM, the C allele of rs3025021 (P = 0.002; OR, 3.8; 95% CI, 1.5-10.0) and the G allele of rs10434 (P = 0.002; OR, 2.6; 95% CI, 1.3-5.3) were most significantly associated with blinding DR. Haplotype analyses suggested an important role for the haplotype TCCGCG in blinding DR (P = 0.0004).

Output: Does common sequence variation in the VEGFA gene predict risk of diabetic retinopathy?


Input: Consider Input: Cardiovascular disease (CVD) is the most important cause of mortality in patients with type 2 diabetes. We aimed to determine the effect of statin therapy versus placebo on the progression of carotid intima-media thickness (IMT) in type 2 diabetic patients without manifest CVD.', 'A randomized, placebo-controlled, double-blind clinical trial was performed in 250 patients with type 2 diabetes. Patients were given either 0.4 mg cerivastatin or placebo daily. In August 2001, when cerivastatin was withdrawn from the market, 0.4 mg cerivastatin was replaced by 20 mg simvastatin without deblinding the study. The primary end point was the change of mean common carotid IMT, as measured by B-mode ultrasound, over 2 years.', 'Common carotid IMT at baseline was 0.780 mm in the placebo group and 0.763 mm in the statin group and did not change significantly after 2 years. There was no significant difference in IMT change in any carotid segment between the groups. LDL cholesterol was reduced by 25% in the statin group and increased by 8% in the placebo group (P <0.001). Cardiovascular events occurred in 12 patients in the placebo group and two patients in the statin group (P=0.006).


Output: Does two-year statin therapy alter the progression of intima-media thickness in patients with type 2 diabetes without manifest cardiovascular disease?