155 research outputs found

    PBFT vs proof-of-authority: Applying the CAP theorem to permissioned blockchain

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    Permissioned blockchains are arising as a solution to federate companies prompting accountable interactions. A variety of consensus algorithms for such blockchains have been proposed, each of which has different benefits and drawbacks. Proof-of-Authority (PoA) is a new family of Byzantine fault-tolerant (BFT) consensus algorithms largely used in practice to ensure better performance than traditional Practical Byzantine Fault Tolerance (PBFT). However, the lack of adequate analysis of PoA hinders any cautious evaluation of their effectiveness in real-world permissioned blockchains deployed over the Internet, hence on an eventually synchronous network experimenting Byzantine nodes. In this paper, we analyse two of the main PoA algorithms, named Aura and Clique, both in terms of provided guarantees and performances. First, we derive their functioning including how messages are exchanged, then we weight, by relying on the CAP theorem, consistency, availability and partition tolerance guarantees. We also report a qualitative latency analysis based on message rounds. The analysis advocates that PoA for permissioned blockchains, deployed over the Internet with Byzantine nodes, do not provide adequate consistency guarantees for scenarios where data integrity is essential. We claim that PBFT can fit better such scenarios, despite a limited loss in terms of performance

    uPAR controls vasculogenic mimicry ability expressed by drug-resistant melanoma cells.

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    Malignant melanoma is a highly aggressive skin cancer characterized by an elevated grade of tumor cell plasticity. Such plasticity allows adaptation of melanoma cells to different hostile conditions and guarantees tumor survival and disease progression, including aggressive features such as drug resistance. Indeed, almost 50% of melanoma rapidly develop resistance to the BRAF(V600E) inhibitor vemurafenib, with fast tumor dissemination, a devastating consequence for patients’ outcomes. Vasculogenic mimicry (VM), the ability of cancer cells to organize themselves in perfused vascular-like channels, might sustain tumor spread by providing vemurafenib-resistant cancer cells with supplementary ways to enter into circulation and disseminate. Thus, this research aims to determine if vemurafenib resistance goes with the acquisition of VM ability by aggressive melanoma cells, and identify a driving molecule for both vemurafenib resistance and VM. We used two independent experimental models of drug-resistant melanoma cells, the first one represented by a chronic adaptation of melanoma cells to extracellular acidosis, known to drive a particularly aggressive and vemurafenib-resistant phenotype, the second one generated with chronic vemurafenib exposure. By performing in vitro tube formation assay and evaluating the expression levels of the VM markers EphA2 and VE-cadherin by Western blotting and flow cytometer analyses, we demonstrated that vemurafenib-resistant cells obtained by both models are characterized by an increased ability to perform VM. Moreover, by exploiting the CRISPR-Cas9 technique and using the urokinase plasminogen activator receptor (uPAR) inhibitor M25, we identified uPAR as a driver of VM expressed by vemurafenib-resistant melanoma cells. Thus, uPAR targeting may be successfully leveraged as a new complementary therapy to inhibit VM in drug-resistant melanoma patients, to counteract the rapid progression and dissemination of the disease

    are drug eluting stents superior to bare metal stents in patients with unprotected non bifurcational left main disease insights from a multicentre registry

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    Aims To compare long-term clinical outcome following drug-eluting stents (DES) or bare-metal stents (BMS) implantation on lesions located at the ostium or the shaft of the left main in a large real-world population. The advent of DES decreased the risk of unprotected left main coronary artery (ULMCA) restenosis when compared with BMS, but it is unclear if this advantage continues when non-bifurcational lesions are considered. Methods and results The GISE-SICI registry is a retrospective, observational multicentre registry promoted by the Italian Society of Invasive Cardiology in which 19 high-volume participating centres enrolled 1453 consecutive patients who underwent percutaneous coronary intervention on ULMCA between January 2002 and December 2006. From the registry, a total of 479 consecutive patients with ostial and shaft lesions who underwent DES ( n = 334) or BMS ( n = 145) implantation were analysed with extensive multivariable and propensity score adjustments. At 3-year follow-up, risk-adjusted survival rates were higher in patients treated with DES than in those treated with BMS. The adjusted hazard ratio (HR) for the risk of mortality after DES implantation relative to BMS implantation was 0.37 (95% CI: 0.15–0.96, P = 0.04). The adjusted HR for the risk of cardiac mortality was 0.31 (95% CI: 0.09–1.04, P = 0.06). The adjusted 3-year rates of target lesion revascularization (TLR) were not significantly lower in the DES group than in the BMS group ( P = 0.60). Conclusion In a large population of patients with lesions located at the ostium or the shaft of the left main in a real-world setting, DES were associated with favourable clinical outcomes when compared with BMS, although there was no evidence of a significant reduction in TLR with DES vs. BMS

    The future of Cybersecurity in Italy: Strategic focus area

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    This volume has been created as a continuation of the previous one, with the aim of outlining a set of focus areas and actions that the Italian Nation research community considers essential. The book touches many aspects of cyber security, ranging from the definition of the infrastructure and controls needed to organize cyberdefence to the actions and technologies to be developed to be better protected, from the identification of the main technologies to be defended to the proposal of a set of horizontal actions for training, awareness raising, and risk management

    Overexpression of the transmembrane carbonic anhydrase isoforms IX and XII in the inflamed synovium

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    Juvenile idiopathic arthritis (JIA) is the most common form of chronic rheumatic disease affecting children worldwide, with some features similar to adult rheumatoid arthritis (RA). In the present study, we aim at investigating novel markers that will allow in the future for tailored, more personalized treatment strategies. Hence, taking notice of several reports proving the role of local acidosis as a causal link between inflammatory diseases and related pain, and the involvement of several carbonic anhydrases (CA, EC 4.2.1.1) isoforms in articular diseases, we evaluated in JIA patients the expression of these metalloenzymes. We identified that JIA patients show high levels of active CA IX and XII isoforms. Our results represent the first evidence of the identification of these enzymes as potential therapeutic targets and development of novel innovative therapies for arthritis, also considering that the two isoforms are validated antitumor target
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