1,557 research outputs found

    Continuous-variable quantum authentication of physical unclonable keys

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    We propose a scheme for authentication of physical keys that are materialized by optical multiple-scattering media. The authentication relies on the optical response of the key when probed by randomly selected coherent states of light, and the use of standard wavefront-shaping techniques that direct the scattered photons coherently to a specific target mode at the output. The quadratures of the electromagnetic field of the scattered light at the target mode are analysed using a homodyne detection scheme, and the acceptance or rejection of the key is decided upon the outcomes of the measurements. The proposed scheme can be implemented with current technology and offers collision resistance and robustness against key cloning.Comment: 15 pages, 7 figure

    Infectious agents and inflammation. The role of microbiota in autoimmune arthritis

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    In higher vertebrates, mucosal sites at the border between the internal and external environments, directly interact with bacteria, viruses, and fungi. Through co-evolution, hosts developed mechanisms of tolerance or ignorance toward some infectious agents, because hosts established "gain of function" interactions with symbiotic bacteria. Indeed, some bacteria assist hosts in different functions, among which are digestion of complex carbohydrates, and absorption and supply of vitamins. There is no doubt that microbiota modulate innate and acquired immune responses starting at birth. However, variations in quality and quantity of bacterial species interfere with the equilibrium between inflammation and tolerance. In fact, correlations between gut bacteria composition and the severity of inflammation were first described for inflammatory bowel diseases and later extended to other pathologies. The genetic background, environmental factors (e.g., stress or smoking), and diet can induce strong changes in the resident bacteria which can expose the intestinal epithelium to a variety of different metabolites, many of which have unknown functions and consequences. In addition, alterations in gut permeability may allow pathogens entry, thereby triggering infection and/or chronic inflammation. In this context, a local event occurring at a mucosal site may be the triggering cause of an autoimmune reaction that eventually involves distant sites or organs. Recently, several studies attributed a pathogenic role to altered oral microbiota in rheumatoid arthritis (RA) and to gut dysbiosis in spondyloarthritis (SpA). There is also growing evidence that different drugs, such as antibiotics and immunosuppressants, can influence and be influenced by the diversity and composition of microbiota in RA and SpA patients. Hence, in complex disorders such RA and SpA, not only the genetic background, gender, and immunologic context of the individual are relevant, but also the history of infections and the structure of the microbial community at mucosal sites should be considered. Here the role of the microbiota and infections in the initiation and progression of chronic arthritis is discussed, as well as how these factors can influence a patient's response to synthetic and biologic immunosuppressive therapy

    100 km secure differential phase shift quantum key distribution with low jitter up-conversion detectors

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    We present a quantum key distribution experiment in which keys that were secure against all individual eavesdropping attacks allowed by quantum mechanics were distributed over 100 km of optical fiber. We implemented the differential phase shift quantum key distribution protocol and used low timing jitter 1.55 um single-photon detectors based on frequency up-conversion in periodically poled lithium niobate waveguides and silicon avalanche photodiodes. Based on the security analysis of the protocol against general individual attacks, we generated secure keys at a practical rate of 166 bit/s over 100 km of fiber. The use of the low jitter detectors also increased the sifted key generation rate to 2 Mbit/s over 10 km of fiber.Comment: 10 pages, 5 figure

    B cells in SLE. Different biological drugs for different pathogenic mechanisms

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    Systemic Lupus Erythematosus (SLE) is a chronic autoimmune disease characterized by a complex multi-factorial pathogenesis and a great clinical polymorphism. SLE is considered to be a B cell disease in which autoantibodies are the major players. Recently, the central role of B cells has been confirmed and it has been shown that that the relative frequency of B cells subsets is altered in SLE patients. Conventional immunosuppressive therapies such as azathioprine, cyclophosphamide or methotrexate, reduce disease activity and improves the patient's general health conditions. These treatments have possible side effects; in fact they could compromise liver function, fertility and innate and adaptive immune responses. Moreover, for unknown reasons a small group of SLE patients is refractory to immunosuppressive therapy. In these cases finding an effective treatment becomes a challenge. The progress in therapeutic antibody technology has led to the production of a wide array of humanized monoclonal antibodies, targeting specific cell types or pathways, initiating a new era in the treatment of autoimmune disorders. In contrast to general immuno-suppression, the availability of drugs interfering with specific pathogenetic pathways gives the possibility to choose therapies tailored to each disease in each patient. © 2007 Elsevier B.V. All rights reserved

    Microbiota and chronic inflammatory arthritis. an interwoven link

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    Background: Only recently, the scientific community gained insights on the importance of the intestinal resident flora for the host's health and disease. Gut microbiota in fact plays a crucial role in modulating innate and acquired immune responses and thus interferes with the fragile balance inflammation versus tolerance. Main body: Correlations between gut bacteria composition and the severity of inflammation have been studied in inflammatory bowel diseases. More recently similar alterations in the gut microbiota have been reported in patients with spondyloarthritis, whereas in rheumatoid arthritis an accumulating body of evidence evokes a pathogenic role for the altered oral microbiota in disease development and course. In the context of dysbiosis it is also important to remember that different environmental factors like stress, smoke and dietary components can induce strong bacterial changes and consequent exposure of the intestinal epithelium to a variety of different metabolites, many of which have an unknown function. In this perspective, and in complex disorders like autoimmune diseases, not only the genetic makeup, sex and immunologic context of the individual but also the structure of his microbial community should be taken into account. Conclusions: Here we provide a review of the role of the microbiota in the onset, severity and progression of chronic inflammatory arthritis as well as its impact on the therapeutic management of these patients. Furthermore we point-out the complex interwoven link between gut-joint-brain and immune system by reviewing the most recent data on the literature on the importance of environmental factors such as diet, smoke and stress

    Cytokine release syndrome in COVID-19 patients, a new scenario for an old concern. The fragile balance between infections and autoimmunity

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    On 7 January 2020, researchers isolated and sequenced in China from patients with severe pneumonitis a novel coronavirus, then called SARS-CoV-2, which rapidly spread worldwide, becoming a global health emergency. Typical manifestations consist of flu-like symptoms such as fever, cough, fatigue, and dyspnea. However, in about 20% of patients, the infection progresses to severe interstitial pneumonia and can induce an uncontrolled host-immune response, leading to a life-threatening condition called cytokine release syndrome (CRS). CRS represents an emergency scenario of a frequent challenge, which is the complex and interwoven link between infections and autoimmunity. Indeed, treatment of CRS involves the use of both antivirals to control the underlying infection and immunosuppressive agents to dampen the aberrant pro-inflammatory response of the host. Several trials, evaluating the safety and effectiveness of immunosuppressants commonly used in rheumatic diseases, are ongoing in patients with COVID-19 and CRS, some of which are achieving promising results. However, such a use should follow a multidisciplinary approach, be accompanied by close monitoring, be tailored to patient’s clinical and serological features, and be initiated at the right time to reach the best results. Autoimmune patients receiving immunosuppressants could be prone to SARS-CoV-2 infections; however, suspension of the ongoing therapy is contraindicated to avoid disease flares and a consequent increase in the infection risk

    Caratterizzazione della resistenza a corrosione di leghe ferrose in liquidi ionici a base imidazolo,

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    The possibility to use ionic liquids (ILs) in several industrial applications, from galvanic to electronics, to CO2 capture in combustion processes, requires a deeper understanding of the compatibility of the ILs of major interest with metallic materials that currently compose industrial plants. This work proposes the evaluation of the corrosion behavior of a carbon steel (API 5L X52) and a stainless steel (AISI 316) in presence of methyl imidazolium based ILs. The analysis focuses on the dependence of ILs corrosiveness on their chemical formulation, with particular reference to the anion composition and to the chain length of the imidazolium cation

    Multipartite entanglement verification resistant against dishonest parties

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    Future quantum information networks will likely consist of quantum and classical agents, who have the ability to communicate in a variety of ways with trusted and untrusted parties and securely delegate computational tasks to untrusted large-scale quantum computing servers. Multipartite quantum entanglement is a fundamental resource for such a network and hence it is imperative to study the possibility of verifying a multipartite entanglement source in a way that is efficient and provides strong guarantees even in the presence of multiple dishonest parties. In this work, we show how an agent of a quantum network can perform a distributed verification of a multipartite entangled source with minimal resources, which is, nevertheless, resistant against any number of dishonest parties. Moreover, we provide a tight tradeoff between the level of security and the distance between the state produced by the source and the ideal maximally entangled state. Last, by adding the resource of a trusted common random source, we can further provide security guarantees for all honest parties in the quantum network simultaneously.Comment: The statement of Theorem 2 has been revised and a new proof is given. Other results unchange
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