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: We hypothesised that short-term application of bi-level nasal continuous positive airway pressure CPAP (SiPAP) compared with conventional nasal CPAP (nCPAP) at the same mean airway pressure in infants with persistent oxygen need recovering from respiratory distress syndrome would improve CO2 removal with no change in oxygen requirement.', 'Non-blinded, randomised, observational four-period crossover study.', 'Level III NICU; low-birthweight infants requiring CPAP and oxygen while recovering from respiratory distress syndrome.', 'Infants requiring nasal CPAP for >24\u2005h prior to study enrolment, and fraction of inspired oxygen requirement (FiO2) of 0.25-0.5, were randomised to either nCPAP or SiPAP. A crossover design with four 1 h treatment periods was used such that each infant received both treatments twice. Oxygen saturations (SaO2), transcutaneous CO2 (tcCO2) and vital signs were monitored continuously. Polysomnographic recordings were analysed for apnoea, bradycardia and oxygen desaturation.', 'Twenty low-birthweight infants receiving 0.3±0.04% supplemental oxygen on CPAP of 6 cm H2O were studied at an average of 33\u2005days of age (±23\u2005days, SD). There were no differences in tcCO2 or other physiological parameters except mean blood pressure, which was lower during nCPAP (52.3±8.3 vs 54.4±9.1\u2005mm\u2005Hg; ±SD; p<0.01). No differences in short or prolonged apnoea, bradycardia or significant desaturation events were observed.
Answer: At similar mean airway pressures, SiPAP does not improve CO2 removal, oxygenation or other studied physiological parameters with the exception of mean blood pressure, which was not clinically significant.
[EX A]: Does bi-level CPAP improve gas exchange when compared with conventional CPAP for the treatment of neonates recovering from respiratory distress syndrome?

[EX Q]: Context: Heterogeneous ribonucleoprotein K (hnRNP K) regulates thymidine phosphorylase (TP) mRNA stability. The aim of the present study was to analyze hnRNP K and TP expression in nasopharyngeal carcinoma (NPC) and to evaluate the prognostic and therapeutic potential of these two markers.', "We analyzed hnRNP K and TP expression immunohistochemically in 121 clinically proven NPC cases. Statistical analyses were applied to correlate cytoplasmic hnRNP K with elevated TP expression and determine the prognostic significance of these parameters. The therapeutic implication of elevated TP expression was determined by measuring sensitivity of NPC cells to the TP-targeting drug, 5-fluoro-5'-deoxyuridine (5'-DFUR).", "There was a high correlation between cytoplasmic hnRNP K and high TP (P < 0.001). Both cytoplasmic hnRNP K and high TP were associated with poor overall survival (OS; P = 0.007 and P < 0.001, respectively) and distant metastasis-free survival (P = 0.003 and 0.001, respectively) of NPC patients. A multivariate analysis confirmed that both cytoplasmic hnRNP K and high TP are independent prognostic predictors for OS (P = 0.020 and 0.010, respectively). NPC cells expressing high TP were more sensitive to treatment with the TP-targeting drug, 5'-DFUR.
Answer: Cytoplasmic hnRNP K and high TP are associated with shorter OS and distant metastasis-free survival in NPC patients. In vitro experiments suggest that NPC tumors with high TP expression may be sensitive to 5'-DFUR treatment. Cytoplasmic hnRNP K and high TP may be potential prognostic and therapeutic markers for NPC, but additional validation studies are warranted.
[EX A]: Are heterogeneous ribonucleoprotein k and thymidine phosphorylase independent prognostic and therapeutic markers for nasopharyngeal carcinoma?

[EX Q]: Context: Although magnesium provides cerebral protection in animal stroke models, magnesium therapy has significant side effects in humans. Therefore, we sought to examine the incidence of alpha-agonist treated hypotension in our ongoing, prospective, randomized, double-blind, placebo-controlled Phase I/IIa dose escalation study of magnesium therapy in patients undergoing carotid endarterectomy.', 'Eighty patients undergoing elective carotid endarterectomy were randomly assigned to a placebo control group (n = 38) or to one of the three intravenous magnesium groups. Magnesium levels were obtained before induction, and then 15 minutes, 1 hour, 2 hours, 6 hours, 12 hours, and 24 hours after a loading dose and infusion. After surgery, a target systolic blood pressure range was chosen, and the amount and duration of phenylephrine needed to maintain that pressure was compared across treatment groups.', 'All treatment groups achieved levels significantly different from baseline at 12 and 24 hours (P < 0.01). Magnesium treatment did not significantly increase the proportion of patients requiring pressure support. For those requiring pressure support, the amount and average duration of phenylephrine required was not different between control patients and those receiving magnesium, even when the individual minimum systolic blood pressures required were subdivided on the basis of dose of magnesium administered.
Answer: There were no significant differences detected in the 1) percentage of patients requiring pressor support, 2) the duration of postoperative pressor support, or 3) the amount of phenylephrine support needed between controls and magnesium treated patients. The percentage of patients requiring pressure support depended on the minimum systolic blood pressure ordered after surgery.
[EX A]:
Are high dose magnesium infusions associated with increased pressor requirements after carotid endarterectomy?