instruction:
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.
question:
Context: Transcatheter aortic valve implantation (TAVI) without predilatation has fewer procedural steps and thereby potentially fewer complications. This has been demonstrated for the antegrade transapical access; however, whether TAVI can be safely performed without predilatation using the retrograde transfemoral route is unknown.', 'We postulated that TAVI is feasible with a balloon-expandable device without predilatation using the retrograde transfemoral route.', 'Twenty-six consecutive patients with stenosis of the native aortic valve (AV) undergoing transfemoral TAVI with the Edwards SAPIEN XT prosthesis without predilatation were enrolled in this retrospective study and compared with 30 patients treated previously with predilatation.', 'The procedure was successfully performed in all 26 patients, irrespective of the AV area and the extent of AV calcification. At baseline mean AV area, mean AV gradient, and median left ventricular ejection fraction were 0.7 0.2 cm(2) , 36.0 17.3 mm Hg, and 55.0% (interquartile range [IQR], 35.0-60.0], respectively; prior to discharge these values were 1.7 0.3 (P < 0.001), 9.8 6.1 mm Hg (P < 0.001), and 57.5% (IQR, 38.7-60.0) (P = not significant). Postdilatation was required in 3 patients due to aortic regurgitation > 2; this was reduced by the procedure to < 2 in all cases. Radiation dose and amount of contrast dye were significantly reduced in comparison with the predilatation group. No periprocedural neurological adverse events occurred. Mortality at 30 days was 0%.
Answer: TAVI without predilatation using the transfemoral Edwards SAPIEN XT valve is feasible and safe. Larger studies are required to further evaluate this approach.
answer:
Is transfemoral aortic valve implantation of Edwards SAPIEN XT without predilatation feasible?

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Context: A complex network of putative molecular interactions underlies the architecture and function of cell-matrix adhesions. Most of these interactions are implicated from coimmunoprecipitation studies using expressed components, but few have been demonstrated or characterized functionally in living cells.', 'We introduce fluorescence fluctuation methods to determine, at high spatial and temporal resolution, "when" and "where" molecular complexes form and their stoichiometry in nascent adhesions (NAs). We focus on integrin-associated molecules implicated in integrin activation and in the integrin-actin linkage in NAs and show that these molecules form integrin-containing complexes hierarchically within the adhesion itself. Integrin and kindlin reside in a molecular complex as soon as adhesions are visible; talin, although also present early, associates with the integrin-kindlin complex only after NAs have formed and in response to myosin II activity. Furthermore, talin and vinculin association precedes the formation of the integrin-talin complex. Finally, -actinin enters NAs periodically and in clusters that transiently associate with integrins. The absolute number and stoichiometry of these molecules varies among the molecules studied and changes as adhesions mature.
Answer: These observations suggest a working model for NA assembly whereby transient -actinin-integrin complexes help nucleate NAs within the lamellipodium. Subsequently, integrin complexes containing kindlin, but not talin, emerge. Once NAs have formed, myosin II activity promotes talin association with the integrin-kindlin complex in a stoichiometry consistent with each talin molecule linking two integrin-kindlin complexes.
answer:
Do integrin-associated complexes form hierarchically with variable stoichiometry in nascent adhesions?

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Context: Despite VOpeak being, generally, greater while running compared to cycling, ventilation (VE) during maximal exercise is less while running compared to cycling. Differences in operating lung volumes (OLV) between maximal running and cycling could be one explanation for previously observed differences in V E and this could be due to differences in body position e.g., trunk/hip angle during exercise.', 'We asked whether OLV differed between maximal running and cycling and if this difference was due to trunk/hip angle during exercise.', 'Eighteen men performed three graded maximal exercise tests; one while running, one while cycling in the drop position (i.e., extreme hip flexion), and one while cycling upright (i.e., seated with thorax upright). Resting flow-volume characteristics were measured in each body position to be used during exercise. Tidal flow-volume loops were measured throughout the exercise.', 'V E during maximal running (148.8 18.9 L min(-1)) tended to be lower than during cycling in the drop position (158.5 24.7 L min(-1); p = 0.07) and in the upright position (158.5 23.7 L min(-1); p = 0.06). End-inspiratory and end-expiratory lung volumes (EILV, EELV) were significantly larger during drop cycling compared to running (87.1 4.1 and 35.8 6.2 vs. 83.9 6.0 and 33.0 5.7% FVC), but only EILV was larger during upright cycling compared to running (88.2 3.5% FVC). OLV and V E did not differ between cycling positions.
Answer: Since OLV are altered by exercise mode, but cycling position did not have a significant impact on OLV, we conclude that trunk/hip angle is likely not the primary factor determining OLV during maximal exercise.
answer:
Are operating lung volumes affected by exercise mode but not trunk and hip angle during maximal exercise?