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.

Context: Concomitant thyroid nodules are the most common reason for false-positive ultrasonography (US) results in primary hyperparathyroidism. The aims of this prospective clinical study were to evaluate false-positive US results according to the characteristics of concomitant thyroid nodules and to determine which characteristics of thyroid nodules are important.', 'This prospective study included 120 consecutive patients with primary hyperparathyroidism. The patients were divided into 2 groups according to preoperative US results. Group 1 consisted of 32 patients with false-positive US results and group 2 consisted of 88 patients with true-positive US results.', 'The risk for false-positive US result was increased 25-fold for patients with parathyroid adenoma weight of more than 500 mg (odds ratio [OR], 25; 95% confidence interval [CI], 8.6-74.5), 75-fold for more than 1 posteriorly located thyroid (OR, 75; 95% CI, 19.3-293.4), 358-fold for the presence of exophytic thyroid nodules (OR, 358; 95% CI, 42.3-3036), and 423-fold for the presence of posteriorly located thyroid nodules (OR, 423; 95% CI, 49-3662).
Answer: Although there was no particular characteristic of concomitant thyroid nodules that contributes to false-positive US results, the posteriorly located thyroid nodules were the strongest correlate for the false-positive US results to other features.
Do the characteristics of concomitant thyroid nodules cause false-positive ultrasonography results in primary hyperparathyroidism?

Context: Barrett esophagus (BE) is considered precursor condition of esophageal adenocarcinoma. Its incidence and prevalence are increasing in general population. Studies reported that metabolic syndrome (MS) or diabetes mellitus (DM) is related to increased risk of BE. Current study was to assess and better understand the relationship between MS /DM and BE.', "Electronic search was conducted in the database Pubmed/Medline (-December, 2015), Embase (-December, 2015), Cochrane Library (-December, 2015), and Web of Knowledge (-December, 2015). Studies included were assessed with summary odds ratios (ORs) with 95% confidence intervals (CIs) and compared exposure group with control group. The heterogeneity was examined by the funnel plot and the Egger's test. Subgroup analyses and sensitive analyses were performed for the detection of possible heterogeneity and impact on stability of analysis results.", "Twelve publications met the criteria and included 355,311 subjects were analyzed. The pooled results showed MS was closely associated with increased risk of BE (OR\u200a=\u200a1.23; 95%CI 1.03-1.47; P\u200a=\u200a0.024), and yet DM did not significantly increase the risk of BE (OR\u200a=\u200a1.07; 95%CI 0.82-1.38; P\u200a=\u200a0.627). Substantial heterogeneities were detected. No significant publication bias was detected by Egger's test (P\u200a=\u200a0.23).
Answer: Based on the results of current meta-analysis, MS is associated with increased risk of BE. Further long-term follow-up prospective study needs to verify the current results, and definite pathophysiological mechanism needs to be further investigated and clearly elucidated.
Is metabolic syndrome associated with increased risk of Barrett esophagus : A meta-analysis?

Context: To investigate the influences of bicortical anchorage on values of natural frequencies of dental implants utilizing the 3-dimensional finite element analysis.', 'Using the commercial code of Solidworks, 3-D models of a screw-shaped dental implant and a mandibular bone segment were generated. After the 3-D implant-bone complex was meshed by ABAQUS software, effects of bicortical anchorage on the buccolingual and axial first-order natural frequencies of the implant were computed.', 'Bicortical anchorage increased both the buccolingual and axial natural frequencies remarkably. As the bicortical anchorage got deeper, the frequencies correspondingly got higher.
Answer: Bicortical anchorage can increase the buccolingual and axial primary stability of dental implants.

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