Search

Background: The frozen elephant trunk(FET) technique is one of the last evolution in the treatment of complex pathologies of the aortic arch and the descending thoracic aorta.Materials and methods: Between January 2007 and March 2021, a total of 396 patients underwent total aortic arch replacements with the FET technique in our centre.The main indications were thoracic aortic aneurysm(n=104,28.2%), chronic aortic dissection(n=224,53.4%) and acute aortic dissection(n=68, 18.4%). We divided the population in two groups according the position of the distal anastomosis (zone 2 vs zone 3) and the length of the stent graft (< 150 mm vs > 150 mm): conservative group (Zone 2 anastomosis + stent length < 150mm, n. 140 pts) and aggressive group (zone 3 anastomosis + stent length > 150mm, n. 141). Results: The overall 30-day mortality rate was 13%(48/369); the risk factor analysis showed that an aggressive approach was neither a risk factor for major complication (permanent dialysis, tracheostomy, bowel malperfusion and permanent paraplegia) neither for 30-day mortality. The survival rate at 1, 5,10 and 15 years was 87.7%,75%,61.3% and 58.4% respectively. During the follow up, an aortic reintervention was performed in 122 patients (38%), 5 patients received a non-aortic cardiac surgery. Freedom from aortic reintervention at 1-,5- and 10-year was 77%,54% and 44% respectively. The freedom from aortic reintervention was higher in the ‘aggressive’ group (62.5%vs40.0% at 5 years, log-rank=0.056). An aggressive approach was not protective for aortic reintervention at follow up and for death at follow up. Conclusions: The FET technique represents a feasible and efficient option in the treatment of complex thoracic aortic pathologies. An aortic reintervention after FET is very common and the decision-making approach should consider and balance the higher risk of an aggressive approach in terms of post-operative complication versus the higher risk of a second aortic reintervention at f

Layered molybdenum disulphide (MoS2) crystals in combination with graphene create the opportunity for the development of heterostructures with tailored surface and structural properties for energy storage applications. Herein, 2D heterostructures are developed by growing MoS2 on epitaxial and self-standing nanoporous graphene (NPG) using chemical vapor deposition (CVD). The effect of substrate as well as different CVD growth parameters such as temperature, amount of sulfur and MoO3 precursors, and argon flow on the growth of MoS2 is systematically investigated. Interestingly, various structures of MoS2 such as monolayer triangular islands, spirals, standing sheets, and irregular stacked multilayered MoS2 are successfully developed. The growth mechanism is proposed using different advanced characterization techniques. The formation of a continuous wetting layer with grain boundaries over the surface prior to formation of any other structures is detected. As a proof of principle, MoS2/NPG is employed for the first time as anode material in potassium ion battery. The electrode delivers a specific capacity of 389 mAh g−1 with over 98% stability after 200 cycles. The porous structures clearly facilitate the ion transport which is beneficial for the ion battery. These encouraging results open new opportunities to develop hierarchical heterostructures of 2D-materials for next-generation energy storage technologies.

We report on a spatial mapping of the electronic and vibrational structure of three-dimensional (3D) nanoporous graphene architectures, which have a hierarchical pore structure. We demonstrate that the topology, curvature, and pores lead to local changes in the electronic and vibrational structure and in the hybridization states of the carbon atoms (sp2 vs. sp3-like). Nitrogen substitutions in pyrrolic bonding configurations also contribute to local distortions of the planar geometry of graphene. The distortions influence the electronic density of states at the Fermi level by shifting the Dirac cone apex, opening potential avenues for applications of two-dimensional graphene in 3D devices.

Erworben im Rahmen der Schweizer Nationallizenzen (http://www.nationallizenzen.ch), A promising correlation between chemical analysis and sensorial evaluation was confirmed: extra virgin olive oils with low contents of methyl and ethyl esters of fatty acids as well as straight chain wax esters were sensorially evaluated as being of high quality, whereas some with high contents were even devaluated as not being of extra virgin quality. Methanol and ethanol formed during fermentation in degrading olives are esterified, largely by transesterification with fatty acids from the triglycerides, and in this way transferred into the pressed oil. The presence of high contents of methyl and ethyl esters in degrading olives was confirmed. Wax esters from the skin of the olives are extracted at low yields, whereby the yield increases when the olives are soft and possibly degrading. High wax ester contents may, therefore, stand for mild oils, but also for deficient oils.

Cardiogenic shock (CS) still remains a leading cause of hospital death. The adoption of percutaneous ventricular assist devices (pVADs) as treatment of CS is an option which continues to rise. Several types of pVADs have been developed by time to provide full cardiac support with few related complications and easy implantation settings. pVADs are used to support the failing heart as a bridge to recovery, decision, durable device or heart transplantation. None of these devices adopted in the clinical practice is ideal for all patients. Disadvantages may be related to the risk of limb/arm ischaemia or cerebral stroke or haemolysis. The most important choice is to identify the best device for each patient depending on haemodynamics, clinical scenario and patient anatomical/pathological issues. This chapter discusses the current pVAD options to treat CS patients.

Scopo della riflessione è, in particolare, offrire una analisi storica e sistematica dei poteri del giudice amministrativo nell’ambito del processo appalti e ciò anche al fine di saggiare il grado di effettività della tutela dei ricorrenti che il menzionato processo è in grado di fornire. Essendo, infatti, passato più di un lustro dalla sua entrata in vigore, si rende opportuna una sua “messa a punto” in ordine a questioni interpretative che la prassi applicativa, ed invero già la dottrina in sede di primo commento, non hanno mancato di evidenziare. Gli snodi problematici selezionati riguardano, in particolare, aspetti nevralgici della struttura processuale, i quali a loro volta fungono da punti di riferimento per l’inizio di una riflessione più ampia circa l’individuazione del modello processuale che si sta venendo a delineare e il suo rapporto con il processo amministrativo ordinario, investigates the issue of special jurisdiction competence on disputes about public contracts The study illustrates the doctrinal and jurisprudential debate on the limits of Administrative jurisdiction in public services and develops topics regarding the consequences in terms of greater protection of the citizen deriving from the Administrative jurisdiction.

Scaling graphene from a two-dimensional (2D) ideal structure to a three-dimensional (3D) millimeter-sized architecture without compromising its remarkable electrical, optical, and thermal properties is currently a great challenge to overcome the limitations of integrating single graphene flakes into 3D devices. Herewith, highly connected and continuous nanoporous graphene (NPG) samples, with electronic and vibrational properties very similar to those of suspended graphene layers, are presented. We pinpoint the hallmarks of 2D ideal graphene scaled in these 3D porous architectures by combining the state-of-the-art spectromicroscopy and imaging techniques. The connected and bicontinuous topology, without frayed borders and edges and with low density of crystalline defects, has been unveiled via helium ion, Raman, and transmission electron microscopies down to the atomic scale. Most importantly, nanoscanning photoemission unravels a 3D NPG structure with preserved 2D electronic density of states (Dirac cone like) throughout the porous sample. Furthermore, the high spatial resolution brings to light the interrelationship between the topology and the morphology in the wrinkled and highly bent regions, where distorted sp2 C bonds, associated with sp3-like hybridization state, induce small energy gaps. This highly connected graphene structure with a 3D skeleton overcomes the limitations of small-sized individual graphene sheets and opens a new route for a plethora of applications of the 2D graphene properties in 3D devices.

Etching with atomic hydrogen as a preparation step before the high-temperature growth process of graphene onto a thin 3C-SiC film grown on Si(111) greatly improves the structural quality of topmost graphene layers. Pit formation and island coalescence, which are typical of graphene growth by SiC graphitization, are quenched and accompanied by widening of the graphene domain sizes to hundreds of nm, and by a significant reduction in surface roughness down to a single substrate bilayer. The surface reconstructions expected for graphene and the underlying layer are shown with atomic resolution by scanning tunnelling microscopy (STM). Spectroscopic features typical of graphene are measured by core-level photoemission and Raman spectroscopy.