In the absence of spin-orbit coupling, the conventional dogma of Anderson localization asserts that all states localize in two dimensions, with a glaring exception: the quantum Hall plateau transition (QHPT). In that case, the localization length diverges and interference-induced quantum-critical spatial fluctuations appear at all length scales. Normally, QHPT states occur only at isolated energies; accessing them therefore requires fine-tuning of the electron density or magnetic field. In this paper we show that QHPT states can be realized throughout an energy continuum, i.e., as an “energy stack” of critical states wherein each state in the stack exhibits QHPT phenomenology. The stacking occurs without fine-tuning at the surface of a class AIII topological phase, where it is protected by U(1) and (anomalous) chiral or time-reversal symmetries. Spectrum-wide criticality is diagnosed by comparing numerics to universal results for the longitudinal Landauer conductance and wave function multifractality at the QHPT. Results are obtained from an effective 2D surface field theory and from a bulk 3D lattice model. We demonstrate that the stacking of quantum-critical QHPT states is a robust phenomenon that occurs for AIII topological phases with both odd and even winding numbers. The latter conclusion may have important implications for the still poorly understood logarithmic conformal field theory believed to describe the QHPT.

Background & aims

More data are needed regarding the long-term impact of the histological progression of non-alcoholic fatty liver disease (NAFLD) on long-term outcomes, including end-stage liver disease (ESLD) and mortality.

Methods

We included Swedish adults with biopsy-confirmed non-cirrhotic NAFLD and ≥2 liver biopsies >6 months apart (1969-2017; n = 718). NAFLD was categorized at initial biopsy as simple steatosis, non-fibrotic steatohepatitis (NASH), or non-cirrhotic fibrosis. NAFLD progression was defined by histological changes between biopsies (i.e. incident NASH, incident fibrosis, fibrosis progression, cirrhosis). Using Cox regression, we estimated multivariable adjusted hazard ratios (aHRs) and 95% CIs for incident ESLD (i.e. hospitalization for decompensated cirrhosis, hepatocellular carcinoma or liver transplantation) and mortality, according to NAFLD progression vs. stable/regressed disease.

Results

At initial biopsy, 497 patients (69.2%) had simple steatosis, 90 (12.5%) had non-fibrotic NASH, and 131 (18.2%) had non-cirrhotic fibrosis. Over a median of 3.4 years between biopsies, 30.4% (218/718) experienced NAFLD progression, including 12.5% (62/497) with incident non-fibrotic NASH, 24.0% (141/587) with incident fibrosis, and 5.6% (40/718) with cirrhosis. Compared to stable/regressed disease, NAFLD progression was associated with significantly higher rates of developing incident ESLD (23.8 vs. 11.4/1,000 person-years [PY]; difference = 12.4/1,000 PY; aHR 1.65, 95% CI 1.17-2.32). While the highest ESLD incidence occurred with progression to cirrhosis (difference vs. stable/regressed disease = 56.3/1,000 PY), significant excess risk was also found with earlier transitions, including from simple steatosis to incident fibrosis (difference vs. stable/regressed disease = 18.9/1,000 PY). In contrast, all-cause mortality rates did not appear to differ when NAFLD progression was compared to stable/regressed disease (difference = 4.7/1,000 PY; aHR 0.99, 95% CI 0.78-1.24).

Conclusions

In a nationwide, real-world cohort of patients with paired NAFLD biopsies, histological disease progression contributed to significantly higher rates of developing incident ESLD, but did not appear to impact all-cause mortality.

Impact and implications

Currently, data are scarce regarding the long-term impact of histological progression or regression of non-alcoholic fatty liver disease (NAFLD) on subsequent risk of adverse clinical outcomes, including the development of end-stage liver disease and mortality. This is particularly important because randomized-controlled trials of NAFLD therapeutics currently focus on short-term histological endpoints as presumed surrogates for those major clinical outcomes. Thus, the results from this study can help inform the optimal design of future NAFLD therapeutic trials, while also providing the necessary evidence base for public health policies focused on preventing the development and progression of NAFLD.

This study introduces a flexible, adhesive-integrated electrode array that was developed to enable non-invasive monitoring of cervical nerve activity. The device uses silver-silver chloride as the electrode material of choice and combines it with an electrode array consisting of a customized biopotential data acquisition unit and integrated graphical user interface (GUI) for visualization of real-time monitoring. Preliminary testing demonstrated this electrode design can achieve a high signal to noise ratio during cervical neural recordings. To demonstrate the capability of the surface electrodes to detect changes in cervical neuronal activity, the cold-pressor test (CPT) and a timed respiratory challenge were employed as stressors to the autonomic nervous system. This sensor system recording, a new technique, was termed Cervical Electroneurography (CEN). By applying a custom spike sorting algorithm to the electrode measurements, neural activity was classified in two ways: (1) pre-to-post CPT, and (2) during a timed respiratory challenge. Unique to this work: (1) rostral to caudal channel position-specific (cephalad to caudal) firing patterns and (2) cross challenge biotype-specific change in average CEN firing, were observed with both CPT and the timed respiratory challenge. Future work is planned to develop an ambulatory CEN recording device that could provide immediate notification of autonomic nervous system activity changes that might indicate autonomic dysregulation in healthy subjects and clinical disease states.

In particle collider experiments, elementary particle interactions with large momentum transfer produce quarks and gluons (known as partons) whose evolution is governed by the strong force, as described by the theory of quantum chromodynamics (QCD)¹. These partons subsequently emit further partons in a process that can be described as a parton shower², which culminates in the formation of detectable hadrons. Studying the pattern of the parton shower is one of the key experimental tools for testing QCD. This pattern is expected to depend on the mass of the initiating parton, through a phenomenon known as the dead-cone effect, which predicts a suppression of the gluon spectrum emitted by a heavy quark of mass m_Q and energy E, within a cone of angular size m_Q/E around the emitter³. Previously, a direct observation of the dead-cone effect in QCD had not been possible, owing to the challenge of reconstructing the cascading quarks and gluons from the experimentally accessible hadrons. We report the direct observation of the QCD dead cone by using new iterative declustering techniques^4,5 to reconstruct the parton shower of charm quarks. This result confirms a fundamental feature of QCD. Furthermore, the measurement of a dead-cone angle constitutes a direct experimental observation of the non-zero mass of the charm quark, which is a fundamental constant in the standard model of particle physics.

The production of the Λ (1520) baryonic resonance has been measured at midrapidity in inelastic pp collisions at s=7TeV and in p–Pb collisions at sNN=5.02TeV for non-single diffractive events and in multiplicity classes. The resonance is reconstructed through its hadronic decay channel Λ (1520) → pK - and the charge conjugate with the ALICE detector. The integrated yields and mean transverse momenta are calculated from the measured transverse momentum distributions in pp and p–Pb collisions. The mean transverse momenta follow mass ordering as previously observed for other hyperons in the same collision systems. A Blast-Wave function constrained by other light hadrons (π, K, KS0, p, Λ) describes the shape of the Λ (1520) transverse momentum distribution up to 3.5GeV/c in p–Pb collisions. In the framework of this model, this observation suggests that the Λ (1520) resonance participates in the same collective radial flow as other light hadrons. The ratio of the yield of Λ (1520) to the yield of the ground state particle Λ remains constant as a function of charged-particle multiplicity, suggesting that there is no net effect of the hadronic phase in p–Pb collisions on the Λ (1520) yield.

Recent pT-integrated cross-section measurements of the ground-state charm mesons and baryons, D0, D+, Ds+, Λc+, and Ξc0, are used to evaluate the charm fragmentation fractions and production cross section per unit of rapidity at midrapidity (|y|<0.5), in pp collisions at s=5.02 TeV at the LHC. The latter is dσcc¯/dy||y|<0.5=1165±44(stat)-101+134(syst) μb. These measurements were obtained for the first time in hadronic collisions at the LHC, including the charm baryon states, recently measured by ALICE at midrapidity. The charm fragmentation fractions differ significantly from the values measured in e+e- and ep collisions, providing evidence of the dependence of the parton-to-hadron fragmentation fractions on the collision system, indicating that the assumption of their universality is not supported by the measured cross sections. An increase of a factor of about 3.3 for the fragmentation fraction for the Λc+ with a significance of 5σ between the values obtained in pp collisions and those obtained in e+e- (ep) collisions is reported. The fragmentation fraction for the Ξc0 was obtained for the first time in any collision system. The measured fragmentation fractions were used to update the cc¯ cross sections per unit of rapidity at |y|<0.5 at s=2.76 and 7 TeV, which are about 40% higher than the previously published results. The data were compared with perturbative-QCD calculations and lie at the upper edge of the theoretical bands.