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Purpose: We evaluated the feasibility and safety of using a new unibody outer double-branched stent-graft system to reconstruct the canine ascending aorta, aortic arch, and supra-aortic vessels. Materials and methods: The outer-branched stent-graft was a unibody design. The branched stent-graft consisted of a main stent-graft and 2 branches. The introducer system included a tri-channel catheter, 2 detachable sleeves, a front fixing device, a constraining wire, and a curved outer sheath. The branched stent-graft was loaded into the introducer system. Ten adult mongrel dogs underwent general anesthesia, and the branched stent-grafts were deployed into the canine ascending aorta, aortic arch, and supra-aortic vessels by the introducer system. All animals were followed up for 3 months. At the end of the follow-up period, computed tomographic angiography (CTA) was performed to observe the patency of the branched stent-grafts. Results: The mean operation time was 142.7±13.7 minutes. The mean fluoroscopy time was 20.73±2.22 minutes. The mean dosage of contrast agent was 95.9±8.7 mL. During the operation, the tri-channel catheters successfully paralleled the wires in the aorta. All 10 branched stent-grafts were successfully implanted into the canine ascending aorta and aortic arch. There were no symptoms of cerebral embolization and no incision infection during the follow-up period. Computed tomographic angiography and specimens showed that the branched stent-grafts and native vessels were patent, the inner surfaces of the branched stent-grafts were covered by neointima, and there was no retrograde aortic dissection in the ascending aorta. Conclusions: This animal research demonstrated that the unibody outer double-branched stent-graft system could be applied to reconstruct the canine ascending aorta, aortic arch, and supra-aortic vessels. Clinical Impact: Thoracic endovascular aortic repair has been the main treatment method for aortic aneurysms or dissections involving the descending thoracic aorta. However, the aortic arch and ascending aorta remain the last segments of the aorta without a validated and routinely used endovascular option. In this research, we designed a new unibody outer branched stent-graft system to reconstruct the distal ascending aorta, aortic arch and supra-aortic vessels. The unibody outer branched stent-graft system could be applied to treat aortic pathologies which involve the middle and distal proximal ascending aorta, aortic arch and proximal descending aorta. [ABSTRACT FROM AUTHOR]

Buried pipeline, as one of the crucial facilities of airport ground engineering, has been extensively utilized for the transportation of petroleum, natural gas, industrial wastewater, and more. However, there are significant gaps in the research on the dynamic response of buried pipelines in airports under the action of dynamic traffic loads, which severely hampers the design and engineering quality of oil transmission pipelines. This study builds a three-dimensional finite element model to simulate the action of vehicles on the pipe–soil structure with actual loads. Moreover, the current research establishes a dynamic analysis model of pipe–soil interaction to analyze the material damping and load parameters. Using the structural dynamic response equation and Rayleigh damping calculation theory, this study investigates the change law of pipe dynamic stress and influencing factors and presents the recommended values of the parameters related to the pipe–soil interaction. Results are as follows. A damping ratio of 0.05 can enhance the time lag of the dynamic response of the structure and weaken the response peak. For the Rayleigh damping parameters, the viscous damping coefficient α has almost no effect on the dynamic response of the pipe–soil structure, so it can be disregarded in the calculation. With the increase of the axial weight of the traffic load above the pavement structure, the peak value of each dynamic response quantity of the pipe–soil structure and load magnitude. The suggested value of the dynamic load coefficient of the pipe–soil structure is 1.5. Lastly, the earth pressure and dynamic load coefficients are suggested to take values for different load and axle type cases. [ABSTRACT FROM AUTHOR]

Let G be a connected graph with γ ≥ 3 for ν ∈ V(G). We define N[subk](ν) = {u|u ∈ V(G) and d(u, ν) = k}. It is proved that for each vertex ν ∈ V(G) and each independent set S ⊆ N[sub2](ν), if |N(S) ∩ N(ν)| ≥ |s|+1 then G must be a Hamiltonian graph. Several known sufficient conditions for hamiltonian graphs follow as the corollaries of the above result. It is also noted that for each vertex ν ∈ V(G) and each independent set S ⊆ N[sub2](ν), if |N(S) ∩ N(ν)| ≥ |s|+2, then G is pancyclic. [ABSTRACT FROM AUTHOR]

Background-Critical limb ischemia (CLI) is one of the most severe peripheral artery diseases. Angioplasty and bypass surgery are two major approaches for the treatment of CLI, however, it remains unclear which treatment has better benefit/risk ratio. In this paper, we performed a meta-analysis on the available clinical trials to compare these two approaches in terms of mortality, amputation-free survival, 5-year leg salvage, and freedom from surgical re-intervention. The results of this article will provide evidence based information for clinical treatment of CLI. Method-Randomized clinical trials comparing results between angioplasty and bypass surgery in CLI were identified by searching Pubmed (2000-2014) and EMBASE (2000-2014) using the search terms "angioplasty" or "bypass", "CLI" and "clinical trials". Primary outcome subjected to meta-analysis was amputation (of trial leg) free survival in 5 years. Secondary outcomes were 30-day mortality; mortality, re-interventions and leg salvage in 1, 3 and 5 years. Results-Seven clinical trials were selected for meta-analysis. No significant difference was found in the primary outcome-amputation free survival, between angioplasty and bypass surgery groups. The amputation free survival in 1, 3 and 5 years were 332/498 (66.7%), 169/346 (48.8%) and 21/60 (35%) in angioplasty group, versus 484/749 (64.6%), 250/494 (50.6%) and 46/132 (34.8%), in bypass group, respectively. The 30 days mortality rate was significantly higher in bypass treatment group [79/1304 (6.1%)] than in angioplasty group [30/918 (3.3%) [95% CI 0.55 [0.36, 0.86], P=0.008). However, there was no statistical significance in 1, 3 and 5 years mortality between these two groups. Two clinical trials showed that there was no difference in leg salvage between angioplasty and bypass surgery groups either. In addition, no difference was observed in re-vasculation between the two groups. Conclusion-Angioplasty is non-inferior to bypass surgery in regarding the amputation free survival, re-vasculation, leg amputation and overall mortality. However, angioplasty is safer, simple, and less invasive and less cost procedure. It should be considered as the first choice for feasible CLI patients.