228 research outputs found

    Feasibility of inguinal hernioplasty under local anaesthesia in elderly patients.

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    BACKGROUND: The aim of this study is to evaluate the feasibility and the safety of hernioplasty under local anaesthesia in elderly patients with significant comorbidity. METHODS: A total of 218 patients underwent inguinal hernia repair with mesh between June 2009 and July 2012. Presence of comorbid conditions and complications were compared between patients younger and older than 70 years. RESULTS: Hernia repair in older patients were more likely associated with comorbid conditions than in their younger counterparts ( hypertension: 25% vs 8.16%; cardiovascular diseases: 50% vs 22%; benign prostatic hypertrophy 60% vs 30%). The most common postoperative complications in both groups were recurrence, wound infection, urinary retention. There was a slightly higher rate of complication in elderly group. CONCLUSIONS: Inguinal hernia repair with local anaesthesia is quite safe and results in a good success rate in elderly patients despite a higher rate of comorbidity typical of this kind of patient

    Non-malleable codes for space-bounded tampering

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    Non-malleable codes—introduced by Dziembowski, Pietrzak and Wichs at ICS 2010—are key-less coding schemes in which mauling attempts to an encoding of a given message, w.r.t. some class of tampering adversaries, result in a decoded value that is either identical or unrelated to the original message. Such codes are very useful for protecting arbitrary cryptographic primitives against tampering attacks against the memory. Clearly, non-malleability is hopeless if the class of tampering adversaries includes the decoding and encoding algorithm. To circumvent this obstacle, the majority of past research focused on designing non-malleable codes for various tampering classes, albeit assuming that the adversary is unable to decode. Nonetheless, in many concrete settings, this assumption is not realistic

    Peripheral blood mono-nuclear cells implantation in patients with Peripheral Arterial Disease: a pilot study for clinical and biochemical outcome of neoangiogenesis.

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    BACKGROUND: Substantial progresses in the management of peripheral arterial disease (PAD) have been made in the past two decades. Progress in the understanding of the endothelial-platelet interaction during health and disease state has resulted in better antiplatelet drugs that can prevent platelet aggregation, activation and thrombosis during angioplasty and stenting. A role in physiological and pathological angiogenesis in adults has been recently shown in bone marrow–derived circulating endothelial progenitors (BM-DCEPs) identified in the peripheral blood. These findings have paved the way for the development of therapeutic neovascularization techniques using endothelial progenitors. METHODS: This pilot study includes five patients, aged 60 to 75, with a history of claudication and recruited from September 2010 to February 2011 at the A.O.U. Federico II of Naples. PBMNCs have been implanted three times in the limb with the worst ABI value in all the patients included in the study. The clinical follow up was performed during the subsequent 12 months from the beginning of the treatment. RESULTS: In four patients there was a regression of ulcerative lesions. One patient’s condition improved after the first implantation but later did not respond to the further treatments. All patients achieved a pain relief as judged by the numeric pain scale. Pain relief remained satisfactory in three patients for one year. Pain gradually returned to the pre-treatment level in two patients. All patients referred an ameliorating in their quality of life expressed even by an improvement in claudication free walking distance. These improvements are reflected also by intra-arterial digital subtraction angiography (IADSA) that shows an improvement of arterial vascularization. CONCLUSIONS: The data from this study suggest an efficacy of BM-DCEPs implantation in terms of improvement of the vascularization and quality of life in patients affected by Peripheral Arterial Disease. Nevertheless a double-blind placebo-controlled study is needed to confirm our findings

    Quantum correlations in Newtonian space and time: arbitrarily fast communication or nonlocality

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    We investigate possible explanations of quantum correlations that satisfy the principle of continuity, which states that everything propagates gradually and continuously through space and time. In particular, following [J.D. Bancal et al, Nature Physics 2012], we show that any combination of local common causes and direct causes satisfying this principle, i.e. propagating at any finite speed, leads to signalling. This is true even if the common and direct causes are allowed to propagate at a supraluminal-but-finite speed defined in a Newtonian-like privileged universal reference frame. Consequently, either there is supraluminal communication or the conclusion that Nature is nonlocal (i.e. discontinuous) is unavoidable.Comment: It is an honor to dedicate this article to Yakir Aharonov, the master of quantum paradoxes. Version 2 contains some more references and a clarified conclusio

    Causality - Complexity - Consistency: Can Space-Time Be Based on Logic and Computation?

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    The difficulty of explaining non-local correlations in a fixed causal structure sheds new light on the old debate on whether space and time are to be seen as fundamental. Refraining from assuming space-time as given a priori has a number of consequences. First, the usual definitions of randomness depend on a causal structure and turn meaningless. So motivated, we propose an intrinsic, physically motivated measure for the randomness of a string of bits: its length minus its normalized work value, a quantity we closely relate to its Kolmogorov complexity (the length of the shortest program making a universal Turing machine output this string). We test this alternative concept of randomness for the example of non-local correlations, and we end up with a reasoning that leads to similar conclusions as in, but is conceptually more direct than, the probabilistic view since only the outcomes of measurements that can actually all be carried out together are put into relation to each other. In the same context-free spirit, we connect the logical reversibility of an evolution to the second law of thermodynamics and the arrow of time. Refining this, we end up with a speculation on the emergence of a space-time structure on bit strings in terms of data-compressibility relations. Finally, we show that logical consistency, by which we replace the abandoned causality, it strictly weaker a constraint than the latter in the multi-party case.Comment: 17 pages, 16 figures, small correction

    Bell Correlations and the Common Future

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    Reichenbach's principle states that in a causal structure, correlations of classical information can stem from a common cause in the common past or a direct influence from one of the events in correlation to the other. The difficulty of explaining Bell correlations through a mechanism in that spirit can be read as questioning either the principle or even its basis: causality. In the former case, the principle can be replaced by its quantum version, accepting as a common cause an entangled state, leaving the phenomenon as mysterious as ever on the classical level (on which, after all, it occurs). If, more radically, the causal structure is questioned in principle, closed space-time curves may become possible that, as is argued in the present note, can give rise to non-local correlations if to-be-correlated pieces of classical information meet in the common future --- which they need to if the correlation is to be detected in the first place. The result is a view resembling Brassard and Raymond-Robichaud's parallel-lives variant of Hermann's and Everett's relative-state formalism, avoiding "multiple realities."Comment: 8 pages, 5 figure

    ESPRESSO: The next European exoplanet hunter

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    The acronym ESPRESSO stems for Echelle SPectrograph for Rocky Exoplanets and Stable Spectroscopic Observations; this instrument will be the next VLT high resolution spectrograph. The spectrograph will be installed at the Combined-Coud\'e Laboratory of the VLT and linked to the four 8.2 m Unit Telescopes (UT) through four optical Coud\'e trains. ESPRESSO will combine efficiency and extreme spectroscopic precision. ESPRESSO is foreseen to achieve a gain of two magnitudes with respect to its predecessor HARPS, and to improve the instrumental radial-velocity precision to reach the 10 cm/s level. It can be operated either with a single UT or with up to four UTs, enabling an additional gain in the latter mode. The incoherent combination of four telescopes and the extreme precision requirements called for many innovative design solutions while ensuring the technical heritage of the successful HARPS experience. ESPRESSO will allow to explore new frontiers in most domains of astrophysics that require precision and sensitivity. The main scientific drivers are the search and characterization of rocky exoplanets in the habitable zone of quiet, nearby G to M-dwarfs and the analysis of the variability of fundamental physical constants. The project passed the final design review in May 2013 and entered the manufacturing phase. ESPRESSO will be installed at the Paranal Observatory in 2016 and its operation is planned to start by the end of the same year.Comment: 12 pages, figures included, accepted for publication in Astron. Nach

    Pilot study on the antibacterial activity of hydrogen peroxide and silver ions in the hospital environment

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    BACKGROUND: Nosocomial environmental contamination plays an important role in the transmission of several health care-associated pathogens. Control of surfaces contamination can reduce the risk of cross-infection in hospitals. The aim of our study is to evaluate the disinfectant effectiveness of hydrogen peroxide and silver ions, against nosocomial multidrug-resistant strains, when it's used directly on surfaces. METHODS: Staphylococcus aureus ATCC 6538, Pseudomonas aeruginosa ATCC 15442 and the same multidrug-resistant clinical isolates were selected to study the effectiveness of the disinfectant used in suspension or on the clean and dirty surface. RESULTS: Regarding the suspension activity test, the hydrogen peroxide and silver ions resulted effective after 5 min for ATCC strains and after 10 min for multidrug-resistant isolates; about the surface activity test, its action resulted after 10 min for ATCC strains and after 15 min for multidrug-resistant isolates. Moreover, it was more effective when used in the absence or in presence of a low concentration of biological materials. CONCLUSIONS: In a complex environment such as hospital wards, to have a disinfectant notoriously effective but more easy and quick to use would be an useful solution to treat small surfaces occasionally contaminated by biological materials

    Retrieval of the gastric specimen following laparoscopic sleeve gastrectomy. Experience on 275 cases.

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    Severe obesity leads to a high incidence of complications and a decrease in life expectancy, especially among younger adults. Laparoscopic sleeve gastrectomy (LSG) first intended as the first step of biliopancreatic diversion with duodenal switch is gaining a per-se procedure role because of its effectiveness on weight loss and comorbidity resolution. Different techniques have been described for specimen extraction in LSG. In this article we report the technique adopted in 275 LSGs performed in our department. In the first 120 LSGs performed from 2007, the specimen was extracted through a mini laparotomy. In the following 155 cases the technique has been simplified: the grasped specimen has been withdrawn through the 15 mm trocar site. We registered in the fist group six cases of wound infection (5%), ten cases of hematoma (8.3%) and four cases of port site hernia (3.3%). In the second group only one case of hematoma (0.6%, p = 0.01) but no cases of wound infection (p = 0.01) or port site hernia, (p = 0.03) although we registered a specimen perforation during retrieval in 16 patients, were reported. The technique described in the 155 cases of the control group has shown to be more effective than the technique we used in the case group, allowing significantly lower operative time (112.9 ± 1.0 vs 74.9 ± 9.1 p < 0.001) and complications, and providing unchanged costs

    Updatable Blockchains

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    Software updates for blockchain systems become a real challenge when they impact the underlying consensus mechanism. The activation of such changes might jeopardize the integrity of the blockchain by resulting in chain splits. Moreover, the software update process should be handed over to the community and this means that the blockchain should support updates without relying on a trusted party. In this paper, we introduce the notion of updatable blockchains and show how to construct blockchains that satisfy this definition. Informally, an updatable blockchain is a secure blockchain and in addition it allows to update its protocol preserving the history of the chain. In this work, we focus only on the processes that allow securely switching from one blockchain protocol to another assuming that the blockchain protocols are correct. That is, we do not aim at providing a mechanism that allows reaching consensus on what is the code of the new blockchain protocol. We just assume that such a mechanism exists (like the one proposed in NDSS 2019 by Zhang et. al), and show how to securely go from the old protocol to the new one. The contribution of this paper can be summarized as follows. We provide the first formal definition of updatable ledgers and propose the description of two compilers. These compilers take a blockchain and turn it into an updatable blockchain. The first compiler requires the structure of the current and the updated blockchain to be very similar (only the structure of the blocks can be different) but it allows for an update process more simple, efficient. The second compiler that we propose is very generic (i.e., makes few assumptions on the similarities between the structure of the current blockchain and the update blockchain). The drawback of this compiler is that it requires the new blockchain to be resilient against a specific adversarial behaviour and requires all the honest parties to be online during the update process. However, we show how to get rid of the latest requirement (the honest parties being online during the update) in the case of proof-of-work and proof-of-stake ledgers
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