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.
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Question: This study investigated the isolated and combined effects of heat [temperate (22\xa0°C/30\xa0% rH) vs. hot (35\xa0°C/40\xa0% rH)] and hypoxia [sea level (FiO2 0.21) vs. moderate altitude (FiO2 0.15)] on exercise capacity and neuromuscular fatigue characteristics.', 'Eleven physically active subjects cycled to exhaustion at constant workload (66\xa0% of the power output associated with their maximal oxygen uptake in temperate conditions) in four different environmental conditions [temperate/sea level (control), hot/sea level (hot), temperate/moderate altitude (hypoxia) and hot/moderate altitude (hot\xa0+\xa0hypoxia)]. Torque and electromyography (EMG) responses following electrical stimulation of the tibial nerve (plantar-flexion; soleus) were recorded before and 5\xa0min after exercise.', 'Time to exhaustion was reduced (P\xa0<\xa00.05) in hot (-35\xa0±\xa015\xa0%) or hypoxia (-36\xa0±\xa014\xa0%) compared to control (61\xa0±\xa028\xa0min), while hot\xa0+\xa0hypoxia (-51\xa0±\xa020\xa0%) further compromised exercise capacity (P\xa0<\xa00.05). However, the effect of temperature or altitude on end-exercise core temperature (P\xa0=\xa00.089 and P\xa0=\xa00.070, respectively) and rating of perceived exertion (P\xa0>\xa00.05) did not reach significance. Maximal voluntary contraction torque, voluntary activation (twitch interpolation) and peak twitch torque decreased from pre- to post-exercise (-9\xa0±\xa01, -4\xa0±\xa01 and -6\xa0±\xa01\xa0% all trials compounded, respectively; P\xa0<\xa00.05), with no effect of the temperature or altitude. M-wave amplitude and root mean square activity were reduced (P\xa0<\xa00.05) in hot compared to temperate conditions, while normalized maximal EMG activity did not change. Altitude had no effect on any measured parameters.

Answer: Does combining heat stress and moderate hypoxia reduce cycling time to exhaustion without modifying neuromuscular fatigue characteristics?


Question: We investigated whether a computed tomography (CT)-based score could predict a large infarct (≥ 80 mL) on early diffusion-weighted magnetic resonance imaging (DWI).', 'Acute stroke patients considered for endovascular therapy within 8 hours of the onset of symptoms were included. The Alberta Stroke Program Early Computed Tomography Score (ASPECTS) was determined on noncontrast CT and computed tomography angiography source images (CTA-SI). Limited collateral flow was defined as less than 50% collateral filling on CTA-SI.', 'Fifty-six patients were analyzed. National Institutes of Health Stroke Scale score was 20 (15-24) in the large infarct group and 16 (11-20) in the small infarct group (P = .049). ASPECTS on noncontrast CT and CTA-SI was 5 (3-8) and 3 (2-6) in the large infarct group and 9 (8-10) and 8 (7-9) in the small infarct group (both P < .001), respectively. Limited collateral flow was frequent in the large infarct group than in the small infarct group (92% vs. 11%, P < .001). Multivariate analysis found that CTA-SI ASPECTS less than or equal to 5 (odds ratio [OR], 40.55; 95% confidence interval [CI], 1.10-1493.44; P = .044) and limited collateral flow (OR, 114.64; 95% CI, 1.93-6812.79; P = .023) were associated with a large infarct. Absence of ASPECTS less than or equal to 5 and limited collateral flow on CTA-SI predicted absence of a large infarct with a sensitivity of .89, specificity of 1.00, positive predictive value of 1.00, and negative predictive value of .71.

Answer: Do collateral flow and brain changes on computed tomography angiography predict infarct volume on early diffusion-weighted imaging?


Question: Hemodilution lowers the total circulatory red cell mass and blood viscosity and thereby may alter the time of passage of red cells and plasma through cerebral microvessels. This study was designed to clarify this question.', 'Adult Wistar-Kyoto rats, aged approximately 32 weeks, were divided into hemodilution and control groups. Local cerebral blood flow and microvascular red cell and plasma volumes in 14 brain structures were measured with the use of [14C]iodoantipyrine, 55Fe-labeled red cells, and [14C]inulin, respectively.', 'In the control group, the hematocrit in cerebral microvessels ranged from 0.29 to 0.45 with a mean of 0.36, which was 71% of the systemic hematocrit (0.51). The mean transit times of blood, red cells, and plasma through microvessels were 0.62 to 1.77 seconds (mean, 0.92 second), 0.44 to 1.15 seconds (mean, 0.65 second), and 0.78 to 2.5 seconds (mean, 1.25 seconds), respectively. In the hemodilution group, the mean hematocrit in microvessels was 0.28, which was 89% of the systemic hematocrit (0.32). Local cerebral blood flow was approximately 59% higher (P < .01) than that of the control animals. The rate of oxygen delivered to the brain was slightly increased (9%) after hemodilution. Blood volume in cerebral microvessels was similar to that of the control group. Mean transit time of blood was 0.62 second (68% of the control), transit time of red cells was 0.53 second (85% of the control), and transit time of plasma was 0.67 second (54% of the control).

Answer:
Does hemodilution accelerate the passage of plasma ( not red cells ) through cerebral microvessels in rats?