Entanglement of two blocks of spins in the critical Ising model

We compute the entropy of entanglement of two blocks of L spins at a distance d in the ground state of an Ising chain in an external transverse magnetic field. We numerically study the von Neumann entropy for different values of the transverse field. At the critical point we obtain analytical results for blocks of size L=1 and L=2. In the general case, the critical entropy is shown to be additive when d goes to infinity. Finally, based on simple arguments, we derive an expression for the entropy at the critical point as a function of both L and d. This formula is in excellent agreement with numerical results.Comment: published versio

Response and relapse rates after treatment with long-acting somatostatin analogs in multifocal or recurrent type-1 gastric carcinoids : a systematic review and meta-analysis

Background: Type-1 gastric neuroendocrine tumors represent a recurring disease and long-acting somatostatin analogs can inhibit both gastrin release and endocrine cell proliferation. The efficacy and timing of this treatment are still unclear. We performed a systematic review of the literature to clarify the role of somatostatin analog treatment in type-1 gastric neuroendocrine tumors. Methods: A computerized literature search was performed using relevant keywords to identify all the pertinent articles published in the last 15 years. Results: Eight studies were included in this systematic review on somatostatin analogs in type-1 gastric neuroendocrine tumors. A complete response rate ranged from 25\u2013100%. When only the six prospective studies were considered, no significant heterogeneity was observed, and the pooled cumulative complete response rate was 84.5% (confidence interval 73.8\u201392.8). Three studies evaluated the type-1 gastric neuroendocrine tumor recurrence, with a cumulative relapse rate of 30.2% (confidence interval 13.1\u201350.6) after 34 months. Conclusion: Somatostatin analogs, namely lanreotide and octreotide, have an excellent response rate, with a good safety profile in selected type-1 gastric neuroendocrine tumors, which cannot be safely managed by endoscopic follow-up or resection due to multiple or frequently recurring disease. After therapy discontinuation, the cumulative relapse rate observed after a median 34-month follow-up was relatively high (30.2%)

The cumulative effects of known susceptibility variants to predict primary biliary cirrhosis risk.

Multiple genetic variants influence the risk for development of primary biliary cirrhosis (PBC). To explore the cumulative effects of known susceptibility loci on risk, we utilized a weighted genetic risk score (wGRS) to evaluate whether genetic information can predict susceptibility. The wGRS was created using 26 known susceptibility loci and investigated in 1840 UK PBC and 5164 controls. Our data indicate that the wGRS was significantly different between PBC and controls (P=1.61E-142). Moreover, we assessed predictive performance of wGRS on disease status by calculating the area under the receiver operator characteristic curve. The area under curve for the purely genetic model was 0.72 and for gender plus genetic model was 0.82, with confidence limits substantially above random predictions. The risk of PBC using logistic regression was estimated after dividing individuals into quartiles. Individuals in the highest disclosed risk group demonstrated a substantially increased risk for PBC compared with the lowest risk group (odds ratio: 9.3, P=1.91E-084). Finally, we validated our findings in an analysis of an Italian PBC cohort. Our data suggested that the wGRS, utilizing genetic variants, was significantly associated with increased risk for PBC with consistent discriminant ability. Our study is a first step toward risk prediction for PBC

Testing a Model of Flow and Heat Transfer for U-shaped Geothermal Exchangers

Among renewable resources, geothermal energy is one of the most promising for its independence on weather conditions. However, design and installation of borehole heat exchangers on low enthalpy regions must consider numerous influencing factors. Here, we focus on the efficiency improvement in hot water production and heating and cooling of buildings of a pilot geothermal plant, which was implemented as part of a hybrid system within the frame of a research project at the University of Camerino (Italy). The aims of the geothermal plant were to study the subsoil thermal properties and monitoring the parameters of the system during operation. As an important application for the design and sizing of low enthalpy geothermal systems, we propose a mathematical model to study the heat transfer between the fluid circulating in the pipes and the underground, where the mutual influence between the soil and the exchanger is considered. We present results of these approximated solutions based on experimental measurements acquired in the actual geothermal exchangers. Laboratory and in situ tests were also carried out to investigate the underground thermal properties and thermal regime of the heterogeneous soil sedimentary succession

Open challenges in the management of autoimmune hepatitis

Autoimmune Hepatitis (AIH) is a rare autoimmune disease of the liver with many open questions as regards its aetiopathogenesis, natural history and clinical management. The classical picture of AIH is chronic hepatitis with fluctuating elevation of serum transaminases and Immunoglobulin G levels, the presence of circulating autoantibodies and typical histological features. However, atypical presentations do occur and are not well captured by current diagnostic scores, with important consequences in terms of missed diagnoses and delayed treatments. AIH is treated with corticosteroids and immunosuppressive drugs but up to 40% of patients do not achieve full biochemical response and are at risk of progressing to cirrhosis and liver failure. Moreover, standard therapies are associated by significant side-effects which may impair the quality of life of patients living with AIH. However, advances in the understanding of the underlying immunology of AIH is raising the prospect of novel therapies and optimisation of existing therapeutic approaches to reduce side-effect burdens and potentially restore immunological tolerance. In this review we outline the clinical characteristics, aetiopathogenesis and management of AIH and current challenges in the diagnosis and management of AIH and provide evidence underlying the evolution of diagnostic and clinical management protocols