Chasing the cuprates with dilatonic dyons

Magnetic field and momentum dissipation are key ingredients in describing condensed matter systems. We include them in gauge/gravity and systematically explore the bottom-up panorama of holographic IR effective field theories based on bulk Einstein-Maxwell Lagrangians plus scalars. The class of solutions here examined appear insufficient to capture the phenomenology of charge transport in the cuprates. We analyze in particular the temperature scaling of the resistivity and of the Hall angle. Keeping an open attitude, we illustrate weak and strong points of the approach.Comment: 30 pages, 2 figures, Version to appear in JHE

On ground states of interacting Composite Fermions with spin at half filling

The effects of interactions in a 2D electron system in a strong magnetic field of two degenerate Landau levels with opposite spins and at filling factors 1/2 are studied. Using the Chern-Simons gauge transformation, the system is mapped to Composite Fermions. The fluctuations of the gauge field induce an effective interaction between the Composite Fermions which can be attractive in both the particle-particle and in the particle-hole channel. As a consequence, a spin-singlet (s-wave) ground state of Composite Fermions can exist with a finite pair-breaking energy gap for particle-particle or particle-hole pairs. The competition between these two possible ground states is discussed. For long-range Coulomb interaction the particle-particle state is favored if the interaction strength is small. With increasing interaction strength there is a crossover towards the particle-hole state. If the interaction is short range, only the particle-particle state is possible.Comment: REVTEX; 12 pages, 5 figures; submitted to Phisical Review

Transport of fractional Hall quasiparticles through an antidot

Current statistics of an antidot in the fractional quantum Hall regime is studied for Laughlin's series. The chiral Luttinger liquid picture of edge states with a renormalized interaction exponent $g$ is adopted. Several peculiar features are found in the sequential tunneling regime. On one side, current displays negative differential conductance and double-peak structures when $g<1$. On the other side, universal sub-poissonian transport regimes are identified through an analysis of higher current moments. A comparison between Fano factor and skewness is proposed in order to clearly distinguish the charge of the carriers, regardless of possible non-universal interaction renormalizations. Super-poissonian statistics is obtained in the shot limit for $g<1$, and plasmonic effects due to the finite-size antidot are tracked.Comment: accepted for publication in Phys. Rev. B, references adde

Electron conductivity and second generation Composite Fermions

The relation between the conductivity tensors of Composite Fermions and electrons is extended to second generation Composite Fermions. It is shown that it crucially depends on the coupling matrix for the Chern-Simons gauge field. The results are applied to a model of interacting Composite Fermions that can explain both the anomalous plateaus in spin polarization and the corresponding maxima in the resistivity observed in recent transport experiments

Infected pancreatic necrosis: outcomes and clinical predictors of mortality. A post hoc analysis of the MANCTRA-1 international study

: The identification of high-risk patients in the early stages of infected pancreatic necrosis (IPN) is critical, because it could help the clinicians to adopt more effective management strategies. We conducted a post hoc analysis of the MANCTRA-1 international study to assess the association between clinical risk factors and mortality among adult patients with IPN. Univariable and multivariable logistic regression models were used to identify prognostic factors of mortality. We identified 247 consecutive patients with IPN hospitalised between January 2019 and December 2020. History of uncontrolled arterial hypertension (p = 0.032; 95% CI 1.135-15.882; aOR 4.245), qSOFA (p = 0.005; 95% CI 1.359-5.879; aOR 2.828), renal failure (p = 0.022; 95% CI 1.138-5.442; aOR 2.489), and haemodynamic failure (p = 0.018; 95% CI 1.184-5.978; aOR 2.661), were identified as independent predictors of mortality in IPN patients. Cholangitis (p = 0.003; 95% CI 1.598-9.930; aOR 3.983), abdominal compartment syndrome (p = 0.032; 95% CI 1.090-6.967; aOR 2.735), and gastrointestinal/intra-abdominal bleeding (p = 0.009; 95% CI 1.286-5.712; aOR 2.710) were independently associated with the risk of mortality. Upfront open surgical necrosectomy was strongly associated with the risk of mortality (p &lt; 0.001; 95% CI 1.912-7.442; aOR 3.772), whereas endoscopic drainage of pancreatic necrosis (p = 0.018; 95% CI 0.138-0.834; aOR 0.339) and enteral nutrition (p = 0.003; 95% CI 0.143-0.716; aOR 0.320) were found as protective factors. Organ failure, acute cholangitis, and upfront open surgical necrosectomy were the most significant predictors of mortality. Our study confirmed that, even in a subgroup of particularly ill patients such as those with IPN, upfront open surgery should be avoided as much as possible. Study protocol registered in ClinicalTrials.Gov (I.D. Number NCT04747990)

Thrombotic complication in Covid19 non hospitalized patients: an underestimated phenomenon?

Intro Thrombotic complications are quite frequent during SARS-CoV2 infection, especially during severe disease and in hospitalized patients. The incidence in mild disease is not clear and probably few cases have been identified. Case report We reported a case of a 60-year-old man with no previous history admitted in our unit for splenic infarct and a floating clot into the descending aorta without signs of severe disease. Discussion Several mechanisms to clarify prothrombotic state have been described and the exact prevalence of thromboembolic phenomenon is probably underestimated. There is no consensus about the treatment and the indication to prevent these complications in non-hospitalized patients. Conclusion Thrombotic events should be suspected also in fit patients with previous or actual symptoms suggestive for Covid 19 infection. Further analysis should be performed to stratify the risk in non hospitalized patients and the indication for prophylactic treatment