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.

[Q]: Context: Material loss at the taper junction of metal-on-metal total hip arthroplasties has been implicated in their early failure. The mechanisms of material loss are not fully understood; analysis of the patterns of damage at the taper can help us better understand why material loss occurs at this junction.', 'We mapped the patterns of material loss in a series of 155 metal-on-metal total hip arthroplasties received at our center by scanning the taper surface using a roundness-measuring machine. We examined these material loss maps to develop a 5-tier classification system based on visual differences between different patterns. We correlated these patterns to surgical, implant, and patient factors known to be important for head-stem taper damage.', 'We found that 63 implants had "minimal damage" at the taper (material loss <1 mm
Answer: These material loss maps allow us to suggest different mechanisms that dominate the cause of the material loss in each pattern: (1) corrosion, (2) mechanically assisted corrosion, or (3) intraoperative damage or poor size tolerances leading to toggling of trunnion in taper.
[A]: Does damage Patterns at the Head-Stem Taper Junction help Understand the Mechanisms of Material Loss?


[Q]: Context: To explore stakeholder views on cell-free DNA testing and highlight findings important for successful implementation and the provision of best practice in counseling.', 'Noninvasive tests based on the analysis of cell-free fetal DNA are now widely available in clinical practice and applications are expanding rapidly. It is essential that stakeholder views are considered in order to identify and address any ethical and social issues. We provide an overview of stakeholder viewpoints and then focus on the key issues of informed decision making, test uptake, service delivery and information sources.
Answer: Stakeholders are positive about the introduction of cell-free fetal DNA testing into clinical practice. They describe both practical and psychological benefits arising from tests that are safe and can potentially be performed earlier in pregnancy. Key concerns, which include the potential for these tests to have a negative impact on informed decision making and increased societal pressure to have testing, can be addressed through careful parent-directed counseling. As applications for these tests expand it is increasingly important to develop innovative approaches to facilitate good understanding for parents who are offered noninvasive prenatal testing.
[A]: Does stakeholder attitudes and need regarding cell-free fetal DNA testing?


[Q]: Context: Critically ill preterm and term neonates are at high risk for negative iron balance due to phlebotomy that occurs with frequent laboratory monitoring, and the high iron demand of rapid growth. Understanding the prioritization of iron between red blood cells (RBCs) and brain is important given iron's role in neurodevelopment.", 'Ten neonatal twin lamb pairs (n = 20) underwent regular phlebotomy for 11 d. Lambs were randomized to receive no iron or i.v. daily iron supplementation from 1 to 5\u2009mg/kg. Serum hemoglobin concentration and reticulocyte count were assayed, iron balance calculated, and iron content of RBCs, liver, brain, muscle, and heart measured at autopsy.', 'Among phlebotomized lambs: (i) liver iron concentration was directly related to net iron balance (r = 0.87; P < 0.001) and (ii) brain iron concentration was reduced as a function of net iron balance (r = 0.63) only after liver iron was depleted. In animals with negative iron balance, total RBC iron was maintained while brain iron concentration decreased as a percentage of the iron present in RBCs (r = -0.70; P < 0.01) and as a function of reticulocyte count (r = -0.63; P < 0.05).
Answer: Phlebotomy-induced negative iron balance limits iron availability to the developing brain.
[A]:
Is iron prioritized to red blood cells over the brain in phlebotomized anemic newborn lambs?