Universality of one-dimensional Fermi systems, I. Response functions and critical exponents

The critical behavior of one-dimensional interacting Fermi systems is expected to display universality features, called Luttinger liquid behavior. Critical exponents and certain thermodynamic quantities are expected to be related among each others by model-independent formulas. We establish such relations, the proof of which has represented a challenging mathematical problem, for a general model of spinning fermions on a one dimensional lattice; interactions are short ranged and satisfy a positivity condition which makes the model critical at zero temperature. Proofs are reported in two papers: in the present one, we demonstrate that the zero temperature response functions in the thermodynamic limit are Borel summable and have anomalous power-law decay with multiplicative logarithmic corrections. Critical exponents are expressed in terms of convergent expansions and depend on all the model details. All results are valid for the special case of the Hubbard model.Comment: 56 pages, 2 figures. arXiv admin note: text overlap with arXiv:1106.035

Towards a cyber physical system for personalised and automatic OSA treatment

Obstructive sleep apnea (OSA) is a breathing disorder that takes place in the course of the sleep and is produced by a complete or a partial obstruction of the upper airway that manifests itself as frequent breathing stops and starts during the sleep. The real-time evaluation of whether or not a patient is undergoing OSA episode is a very important task in medicine in many scenarios, as for example for making instantaneous pressure adjustments that should take place when Automatic Positive Airway Pressure (APAP) devices are used during the treatment of OSA. In this paper the design of a possible Cyber Physical System (CPS) suited to real-time monitoring of OSA is described, and its software architecture and possible hardware sensing components are detailed. It should be emphasized here that this paper does not deal with a full CPS, rather with a software part of it under a set of assumptions on the environment. The paper also reports some preliminary experiments about the cognitive and learning capabilities of the designed CPS involving its use on a publicly available sleep apnea database

Reliability Analysis of Power Electronic Devices

The thesis deals with the reliability of Power Electronic Devices to the purpose of evaluating the phenomena which mainly dictate the limiting conditions where a power device can safely operate. Reliability analyses are conducted by means of either simulations and experimental measurements

Infinitely many solutions to the Dirichlet problem for quasilinear elliptic systems

In this paper we deal with the existence of weak solutions for some Dirichlet problem.The existence of solutions is proved by applying a critical point variational principle obtained by B. Ricceri as consequence of a more general variational principle

Double probe intraoperative neuromonitoring with a standardized method in thyroid surgery

AbstractIntroductionThe purpose of this study was to evaluate the effectiveness of intraoperative neuromonitoring (IONM) of the recurrent laryngeal nerve (RLN) and the vagus nerve (VN) with a standardized approach in thyroid surgery.MethodsRetrospective study with an experimental group with which IONM was used, both with the RLN that the VN, and a control one, each consisting of 300 total thyroidectomies. Each patient underwent a pre-and post-operative videolaryngoscopy. The number of RLNs identified and the number of transient and permanent RNL injuries for each group were assessed, and then compared with χ2 tests. In the experimental group Sensitivity, Specificity, Positive Predictability, Negative Predictability and Accuracy of IONM were evaluated, depending on the number of true positive results, false negatives, true negatives and false positives obtained by comparing the results of IONM with the post-operative videolaryngoscopies.ResultsThe results obtained for the experimental group vs. the control group were: RLNs identified 595 (99.1%) vs. 552 (92%) -P Value <0.0001; Permanent RLNs injuries 4 (1.33%) vs. 5 (1.67%) -P Value 1; transient RLNs injuries 1 (0.33%) vs. 8 (2.67%) -P Value 0.044.The IONM system, for the RLN and VN showed respectively: Sensitivity 66.7% vs. 83.3%; specificity 97.6% vs. 99.5%; Positive Predictability 22.2% vs. 62.5%; Negative Predictability 99.6% vs. 99.3%; Accuracy 97.3% vs. 99.3%.ConclusionsOur study highlights that using IONM with a standardized method in thyroid surgery, improves the ability to identify the RLN and a reduction in the incidence rate of transient RLN injuries

Intramuscular Nodular Fasciitis of the Pectoralis Major.

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Serum and supplement optimization for EU GMP-compliance in cardiospheres cell culture

Cardiac progenitor cells (CPCs) isolated as cardiospheres (CSs) and CS-derived cells (CDCs) are a promising tool for cardiac cell therapy in heart failure patients, having CDCs already been used in a phase I/II clinical trial. Culture standardization according to Good Manufacturing Practices (GMPs) is a mandatory step for clinical translation. One of the main issues raised is the use of xenogenic additives (e.g. FBS, foetal bovine serum) in cell culture media, which carries the risk of contamination with infectious viral/prion agents, and the possible induction of immunizing effects in the final recipient. In this study, B27 supplement and sera requirements to comply with European GMPs were investigated in CSs and CDCs cultures, in terms of process yield/efficiency and final cell product gene expression levels, as well as phenotype. B27- free CS cultures produced a significantly reduced yield and a 10-fold drop in c-kit expression levels versus B27+ media. Moreover, autologous human serum (aHS) and two different commercially available GMP AB HSs were compared with standard research-grade FBS. CPCs from all HSs explants had reduced growth rate, assumed a senescent-like morphology with time in culture, and/or displayed a significant shift towards the endothelial phenotype. Among three different GMP gamma-irradiated FBSs (giFBSs) tested, two provided unsatisfactory cell yields, while one performed optimally, in terms of CPCs yield/phenotype. In conclusion, the use of HSs for the isolation and expansion of CSs/CDCs has to be excluded because of altered proliferation and/or commitment, while media supplemented with B27 and the selected giFBS allows successful EU GMP-complying CPCs culture