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Aluminum foam is expected to be one of the candidates for lightweight materials for structural components as it is lightweight and has excellent shock absorption and sound absorption properties. However, aluminum foam has low tensile and flexural strength due to its thin cell walls. Therefore, aluminum foam is used by combining with dense materials. In particular, with the recent trend toward multi-materials, research on the combination with lightweight resins is expected. In this study, we attempted to join aluminum foam fabricated by the precursor method to a thermoplastic resin polycarbonate (PCTA) plate by friction welding. It was found that the aluminum foam and PCTA plate can be joined in about 1 min by friction welding, by rotating the aluminum foam at 2000 rpm and pressing 1 mm into the PCTA plate. In addition, in the friction welding of aluminum foam and PCTA plate, it was found that the pores of the aluminum foam were maintained without being collapsed. The anchoring effect is presumably caused by the penetration of PCTA softened by the frictional heat generated by the friction welding into the pores. Furthermore, tensile tests of the joined samples showed that fracture occurred either at the joining interface or at the base material of the aluminum foam, and that the joining strength was equivalent to the tensile strength of the aluminum foam itself. [ABSTRACT FROM AUTHOR]

Background Ventricular arrhythmias (VAs) are common after a left ventricular assist device (LVAD) implantation. Further, the majority of post-LVAD ventricular tachycardias (VTs) are secondary to a preexisting cardiomyopathy substrate. Intraoperative ablation of patients with recurrent preoperative VTs may reduce post-LVAD VTs. Case summary A 59-year-old female with advanced heart failure due to non-ischaemic cardiomyopathy (LV ejection fraction = 24%) and recurrent VTs was referred for an LVAD implantation as a bridge to a heart transplant (INTERMACS Profile-5A). The previous endocardial ablation failed due to an epicardial arrhythmogenic substrate. Therefore, open-chest epicardial mapping during the LVAD implantation was indicated and three target areas of the arrhythmogenic substrate were found, which were ablated by radiofrequency applications. To minimize the cardiopulmonary bypass time, cardiopulmonary bypass was initiated after ablation, and then, an LVAD was implanted. An additional 68 min was required for mapping and ablation. All procedures were performed without any complications, and the post-operative course was uneventful. Thereafter, no VT episodes were observed without any anti-arrhythmic drugs during a 15-month follow-up with LVAD support. Discussion Intraoperative epicardial mapping and ablation during an LVAD implantation can play an important role in the management of LVAD recipients with recurrent VAs. [ABSTRACT FROM AUTHOR]

Owing to its lightweight and excellent shock-absorbing properties, aluminum foam is used in automotive parts and construction materials. If a nondestructive quality assurance method can be established, the application of aluminum foam will be further expanded. In this study, we attempted to estimate the plateau stress of aluminum foam via machine learning (deep learning) using X-ray computed tomography (CT) images of aluminum foam. The plateau stresses estimated by machine learning and those actually obtained using the compression test were almost identical. Consequently, it was shown that plateau stress can be estimated by training using the two-dimensional cross-sectional images obtained nondestructively via X-ray CT imaging. [ABSTRACT FROM AUTHOR]

Background: Abdominal aortic aneurysm (AAA) is a life-threatening cardiovascular disease characterized by dilated abdominal aorta. Immune cells have been shown to contribute to the development of AAA, and that the gut microbiota is associated with numerous diseases, including cardiovascular diseases, by regulating immune systems or metabolic pathways of the host. However, the interaction between the gut microbiota and AAA remains unknown.Methods: Apolipoprotein E-deficient male mice were fed a high-cholesterol diet and divided into three groups: the control group was maintained under normal water (control group), the oral AVNM group was maintained under drinking water supplemented with ampicillin, vancomycin, neomycin, and metronidazole, and the i.p. AVNM group was injected AVNM intraperitoneally. After 1 week of pretreatment with antibiotics, these mice were administrated Ang II via subcutaneous osmotic pumps for 4 weeks and euthanized to evaluate AAA formation.Results: Depletion of gut microbiota by oral AVNM ameliorated the incidence of AAAs (control group: 58.9% versus oral AVNM group: 28.6% versus i.p. AVNM group: 75.0%, P = 0.0005) and prevented death due to ruptured aneurysms (control group: 11% versus oral AVNM group: 0% versus i.p. AVNM group: 15%). Oral AVNM suppressed monocyte storage in the spleen, but not in other organs. Despite possessing a higher level of cholesterol, recruitment of monocytes into the suprarenal aorta was suppressed in the oral AVNM group. In AVNM drinking mice, NOD1 ligand, a kind of PRR ligands, increased the development of AAAs and accumulation of macrophages in the aortae.Conclusions: The gut microbiota plays a critical role in AAA formation. Therefore, regulation of the microbiota or the immune system can be a therapeutic approach for AAA. [ABSTRACT FROM AUTHOR]

Open in new tab Download slide OBJECTIVES The goal of this study was to evaluate the fate of the downstream aorta following total arch replacement. METHODS Between October 1999 and March 2018, a total of 740 patients underwent total arch replacement. After excluding connective tissue disease, previous descending or thoracoabdominal aortic surgery, patients without adequate preoperative images or operative mortality, late outcomes consisting of additional surgery for distal dilation and distal aortic events were evaluated in 623 survivors (240 aortic dissections, including 139 patients with acute dissection and 383 with a non-dissection aneurysm). The mean follow-up was 5.0 ± 4.0 years. RESULTS The mean preoperative maximum diameter of the descending aorta was 36.9 ± 8.0 mm. An elephant trunk was inserted in 232 patients, including 183 patients with aortic dissection. Freedom from additional surgery for distal dilation was 88.5% at 5 years and 80.2% at 10 years. Freedom from distal aortic events was 81.9% at 5 years and 70.5% at 10 years. Multivariable regression analysis demonstrated that the preoperative diameter of the descending aorta was a significant risk factor for unfavourable distal aortic events. Computed tomography evaluation demonstrated a significant increase in the descending aortic diameter over time (P  < 0.001). Positive aortic remodelling was observed in the proximal descending (P  < 0.001) to mid-descending (P  < 0.001) aorta exclusively in patients with acute aortic dissection. CONCLUSIONS The diameter of the descending aorta increased significantly after total arch replacement, particularly in the distal descending aorta. The preoperative descending aortic diameter portended a significant risk for unfavourable distal aortic events. [ABSTRACT FROM AUTHOR]

Activation of the zinc-finger transcription factor early growth response (Egr)-1, initially linked to developmental processes, is shown here to function as a master switch activated by ischemia to trigger expression of pivotal regulators of inflammation, coagulation and vascular hyperpermeability. Chemokine, adhesion receptor, procoagulant and permeability-related genes are coordinately upregulated by rapid ischemia-mediated activation of Egr-1. Deletion of the gene encoding Egr-1 strikingly diminished expression of these mediators of vascular injury in a murine model of lung ischemia/reperfusion, and enhanced animal survival and organ function. Rapid activation of Egr-1 in response to oxygen deprivation primes the vasculature for dysfunction manifest during reperfusion. These studies define a central and unifying role for Egr-1 activation in the pathogenesis of ischemic tissue damage., Author(s): Shi-Fang Yan (corresponding author) [1]; Tomoyuki Fujita [1]; Jiesheng Lu [1]; Kenji Okada [1]; Yu Shan Zou [1]; Nigel Mackman [4]; David J. Pinsky [3]; David M. Stern [1, [...]