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.

Ex Input:
The cutaneous microcirculation vasodilates during acute 6 degrees head-down tilt (HDT, simulated microgravity) relative to upright conditions, more in the lower body than in the upper body.', 'We expected that relative magnitudes of and differences between upper and lower body cutaneous blood flow elevation would be sustained during initial acclimation to simulated microgravity.', 'We measured cutaneous microvascular blood flow with laser-Doppler flowmetry at the leg (over the distal tibia) and cheek (over the zygomatic arch) of eight healthy men before, during, and after 24 h of HDT. Results were calculated as a percentage of baseline value (100% measured during pre-tilt upright sitting).', 'Cutaneous blood flow in the cheek increased significantly to 165 +/- 37% (mean +/- SE, p < 0.05) at 9-12 h HDT, then returned to near baseline values by 24 h HDT (114 +/- 29%, NSD), despite increased local arterial pressure. Microvascular flow in the leg remained significantly elevated above baseline throughout 24 h HDT (427 +/- 85% at 3 h HDT and 215 +/- 142% at 24 h HDT, p < 0.05). During the 6-h upright sitting recovery period, cheek and leg blood flow levels returned to near pre-tilt baseline values.

Ex Output:
Does simulated microgravity increase cutaneous blood flow in the head and leg of humans?


Ex Input:
Two-dimensional speckle tracking echocardiography (2DSTE) has been used widely in research, but rarely in clinical practice because data acquisition and analysis are time-consuming. By reducing the acquisition and analysis time, 3-dimensional STE may improve clinical impact. We investigated the feasibility of 3DSTE myocardial deformation, with comparison to 2DSTE.', 'Transthoracic 3DSTE and 2DSTE were performed in 230 adults (138 men, 51 ± 14 years, and 142 hypertension, 10 heart failure and 78 normotensive subjects). The variables of LV deformation were analyzed using EchoPAC software.', 'The 3D LV longitudinal (LS) analysis was feasible in 84.9% of the study subjects, which was lower than the 2D analysis (97.2%). The success rates for circumferential strain (CS) and radial strain (RS) were similar between the 2D and 3D techniques. All magnitude of strains measured by 2DSTE and 3DSTE were significantly correlated. The magnitude of 3D LS and CS was lower, but the 3D RS is higher than that of 2DSTE (-18.5 ± 2.8 vs. -21.2 ± 3.5; 20.8 ± 4.1 vs. 21.7; and 50.0 ± 11.2 vs. 37.7 ± 12.6, respectively). Strains measured by 3DSTE exhibited stronger correlation with LV ejection fraction (EF) than that by 2DSTE. In inter- and intra-observer reproducibility for 3D LS, CS, RS and AS were acceptable. The mean time of analysis for LV volume, EF and strains was 116s by 3DSTE, which was significantly shorter than that by 2DSTE (5 min, P<0.0001).

Ex Output:
Is three-dimensional speckle strain echocardiography more accurate and efficient than 2D strain in the evaluation of left ventricular function?


Ex Input:
Cardiovascular device-centered infections are a major cause of hospital morbidity, mortality, and expense. Caused by opportunistic bacteria, this phenomenon is thought to arise because of a defect in neutrophil bacterial killing. We have shown that neutrophils that adhere to polystyrene remain viable, whereas neutrophils that adhere to the vascular biomaterials expanded polytetrafluoroethylene (ePTFE) and Dacron undergo a rapid nonapoptotic death. This study was designed to test the hypothesis that surface topography is a determinant of the nonapoptotic death response of neutrophils to biomaterials.', 'We took advantage of the ease with which a polystyrene surface can be manipulated to examine the effect of surface topography on neutrophil viability. Neutrophils were exposed to smooth or roughened polystyrene surfaces both in vivo and in vitro. Changes in cell membrane permeability and production of reactive oxygen species by individual cells were monitored with fluorescent dyes.', 'Host cells and isolated human neutrophils died rapidly after adhesion to roughened polystyrene. Neutrophils adherent to roughened surfaces produced more reactive oxygen intermediates than those adherent to smooth surfaces and were first to die. The cell death response precipitated by expanded polytetrafluoroethylene, Dacron, or the roughened surfaces was significantly reduced with treatment of the neutrophils with catalase, diphenylene iodonium, or the src kinase inhibitor PP2 before adhesion.

Ex Output:

Is neutrophil survival on biomaterials determined by surface topography?