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In an effort to scale down electronic devices to atomic dimensions 1 , the use of transition-metal oxides may provide advantages over conventional semiconductors. Their high carrier densities and short electronic length scales are desirable for miniaturization 2 , while strong interactions that mediate exotic phase diagrams 3 open new avenues for engineering emergent properties 4 , 5 . Nevertheless, understanding how their correlated electronic states can be manipulated at the nanoscale remains challenging. Here, we use angle-resolved photoemission spectroscopy to uncover an abrupt destruction of Fermi liquid-like quasiparticles in the correlated metal LaNiO 3 when confined to a critical film thickness of two unit cells. This is accompanied by the onset of an insulating phase as measured by electrical transport. We show how this is driven by an instability to an incipient order of the underlying quantum many-body system, demonstrating the power of artificial confinement to harness control over competing phases in complex oxides with atomic-scale precision. An insulating phase abruptly emerges in LaNiO 3 when its thickness is reduced to only two unit cells.

The silver chalcogenide semimetals are known for their appealing magnetoresistive properties. It is now shown that when copper silver selenide is doped with nickel, these properties are maintained, resulting in high electron mobilities and, in turn, a significant thermoelectric effect. The electron mobility is one of the key parameters that characterize the charge-carrier transport properties of materials, as exemplified by the quantum Hall effect 1 as well as high-efficiency thermoelectric and solar energy conversions 2 , 3 . For thermoelectric applications, introduction of chemical disorder is an important strategy for reducing the phonon-mediated thermal conduction, but is usually accompanied by mobility degradation. Here, we show a multilayered semimetal β-CuAgSe overcoming such a trade-off between disorder and mobility. The polycrystalline ingot shows a giant positive magnetoresistance and Shubnikov de Haas oscillations, indicative of a high-mobility small electron pocket derived from the Ag s -electron band. Ni doping, which introduces chemical and lattice disorder, further enhances the electron mobility up to 90,000 cm 2  V −1  s −1 at 10 K, leading not only to a larger magnetoresistance but also a better thermoelectric figure of merit. This Ag-based layered semimetal with a glassy lattice is a new type of promising thermoelectric material suitable for chemical engineering.

A new class of materials termed topological insulators have been intensively investigated due to their unique Dirac surface state carrying dissipationless edge spin currents. Recently, it has been theoretically proposed that the three dimensional analogue of this type of band structure, the Weyl Semimetal phase, is materialized in pyrochlore oxides with strong spin-orbit coupling, accompanied by all-in-all-out spin ordering. Here, we report on the fabrication and magnetotransport of Eu 2 Ir 2 O 7 single crystalline thin films. We reveal that one of the two degenerate all-in-all-out domain structures, which are connected by time-reversal operation, can be selectively formed by the polarity of the cooling magnetic field. Once formed, the domain is robust against an oppositely polarised magnetic field, as evidenced by an unusual odd field dependent term in the magnetoresistance and an anomalous term in the Hall resistance. Our findings pave the way for exploring the predicted novel quantum transport phenomenon at the surfaces/interfaces or magnetic domain walls of pyrochlore iridates.

The use of accelerated beams of electrons, protons or ions has furthered the development of nearly every scientific discipline. However, high-energy muon beams of equivalent quality have not yet been delivered. Muon beams can be created through the decay of pions produced by the interaction of a proton beam with a target. Such ‘tertiary’ beams have much lower brightness than those created by accelerating electrons, protons or ions. High-brightness muon beams comparable to those produced by state-of-the-art electron, proton and ion accelerators could facilitate the study of lepton–antilepton collisions at extremely high energies and provide well characterized neutrino beams 1 – 6 . Such muon beams could be realized using ionization cooling, which has been proposed to increase muon-beam brightness 7 , 8 . Here we report the realization of ionization cooling, which was confirmed by the observation of an increased number of low-amplitude muons after passage of the muon beam through an absorber, as well as an increase in the corresponding phase-space density. The simulated performance of the ionization cooling system is consistent with the measured data, validating designs of the ionization cooling channel in which the cooling process is repeated to produce a substantial cooling effect 9 – 11 . The results presented here are an important step towards achieving the muon-beam quality required to search for phenomena at energy scales beyond the reach of the Large Hadron Collider at a facility of equivalent or reduced footprint 6 . Ionization cooling, a technique that delivers high-brightness muon beams for the study of phenomena at energy scales beyond those of the Large Hadron Collider, is demonstrated by the Muon Ionization Cooling Experiment.

Primary challenges for current and future precision neutrino experiments using liquid argon time projection chambers (LArTPCs) include understanding detector effects and quantifying the associated systematic uncertainties. This paper presents a novel technique for assessing and propagating LArTPC detector-related systematic uncertainties. The technique makes modifications to simulation waveforms based on a parameterization of observed differences in ionization signals from the TPC between data and simulation, while remaining insensitive to the details of the detector model. The modifications are then used to quantify the systematic differences in low- and high-level reconstructed quantities. This approach could be applied to future LArTPC detectors, such as those used in SBN and DUNE.

Background Eosinophilic esophagitis (EoE) is a chronic inflammatory condition of the esophagus associated with dysphagia and esophageal fibrosis. The incidence of EoE is not precisely known, and significant heterogeneity in study design and disease definition have led to widely variable estimates. Through the ESPRESSO (Epidemiology Strengthened by histoPathology Reports in Sweden) study we performed a nationwide population-based study to estimate the incidence and temporal patterns of biopsy-verified EoE. Methods Between October 2015 and April 2017, we contacted all pathology departments in Sweden ( n  = 28) to obtain biopsy report data on EoE. To assure a high degree of completeness, we restricted the study to 2004–2015. We then calculated age-specific and age-standardized incidence rates. Results We identified 1412 incident EoE cases between 2004–2015. The overall age-standardized incidence rates of EoE in Sweden was 1.22 per 100,000 person-years. During the study period, there was a significant increase of 33% [95%CI = 31–36%] ( P  < 0.001) per year in EoE incidence, and in the last 3 years of follow-up (2013–2015) the incidence was 2.79 per 100,000 person-years. This corresponds to a lifetime risk of biopsy-verified EoE for men of 0.33% (1 in 295 men) and for women 0.12% (1 in 813 women). We observed an early peak of EoE disgnosed at age 15–19 years for both males and females, and a second peak in the late 30 s for males, and early 40 s for females. We noted a 3:1 male-to-female predominance, which did not significantly vary over time. Conclusions EoE seems to be increasing in Sweden, with an overall age-standardized incidence of EoE of 1.22 per 100,000 person-years in the last decade.

There are limited data on the familial risk of distal eosinophilic gastrointestinal diseases (EGIDs) in patients with eosinophilic esophagitis (EoE). We analyzed the risk of eosinophilic gastritis/gastroenteritis (EG/EGE) and eosinophilic colitis (EC) as forms of distal EGIDs using International Disease Classification-9/10 codes in subjects with EoE and their relatives. The Utah Population Database is a resource that links genealogy information and medical records in Utah. We identified EGIDs in probands and their first-degree (FDRs), second-degree (SDRs), and third-degree (TDRs) relatives in the Utah Population Database. Relative risk and 95% confidence intervals were estimated. All individuals with inflammatory bowel disorder were eliminated to avoid misdiagnosis with EGIDs. We included 8,455 subjects with EoE, 396 with EG/EGE, and 172 with EC. Probands with EoE were at increased risk of EG/EGE and EC. Risks of EG/EGE were increased among FDRs and SDRs of probands with EoE , even without concomitant EoE in the relatives. Increased risk of EG/EGE in FDRs and SDRs was also present for EoE probands without EG/EGE or EC. We observed no isolated familial aggregation of EG/EGE after excluding cases with comorbid EoE. EC probands without EoE were at increased risk of EG/EGE, but no evidence of familial risk of EC was observed. The relative risk of EG/EGE is significant among relatives of patients with EoE, suggesting that shared genetic factors exist among these EGIDs. EG/EGE and EC showed limited familial clustering, although sample sizes were small.

AbstractObjectivesThe present study aimed at investigating the prevalence of prefrailty and frailty in South American older adults according to the setting and region. DesignA literature search combining the terms “frailty”, “South America” or a specific country name was performed on PubMed, EMBASE, Lilacs, and Scielo to retrieve articles published in English, Portuguese or Spanish on or before August 2019. ParticipantsOlder adults aged 60+ years from any setting classified as frail according to a validated scale were included in the study. MeasurementsFrailty assessment by a validated scale. ResultsOne-hundred eighteen reports (98 performed from Brazil, seven from Chile, five from Peru, four from Colombia, two from Ecuador, one from Argentina, and one from Venezuela) were included in the study. The mean prevalence of prefrailty in South America was 46.8% (50.7% in older in-patients, 47.6% in the community, and 29.8% in nursing-home residents). The mean prevalence of frailty in South America was 21.7% (55.8% in nursing-home residents, 39.1% in hospitalized older adults, and 23.0% in the community). ConclusionsPrefrailty and frailty are highly prevalent in South American older adults, with rates higher than those reported in Europe and Asia. In the community, almost one-in-two is prefrail and one-in-five is frail, while hospitalized persons and nursing-home residents are more frequently affected. These findings indicate the need for immediate attention to avoid frailty progression toward negative health outcomes. Our findings also highlight the need for specific guidelines for the management of frailty in South America.

ObjectiveEosinophils are hallmarks in allergic type 2 inflammation and are known to release cytotoxic granule proteins that contribute to inflammation. Eosinophils develop in the bone marrow from hematopoietic stem cells and once mature, have a limited lifespan in culture, making them difficult to study ex vivo . IL-33 has increasingly been shown as a key regulator of type 2 inflammation via signaling through its receptor, ST2. The present study was conducted to detail a method of eosinophil differentiation from hematopoietic stem cells and determine the response to IL-33.MethodsCD34+ and CD14+ cells were isolated from donor apheresis cones and differentiated into eosinophils or macrophage controls, respectively. Morphologic, transcriptional and protein analyses were performed to validate this method of eosinophil differentiation. The effect of IL-33 on differentiated eosinophils was assessed using qPCR, immunofluorescence, and multiplex cytokine array.ResultsCD34 differentiated eosinophils appear morphologically similar by H&E and express eosinophil peroxidase (EPX) protein as well as the conventional eosinophil transcripts EPX , CLC , and MBP . In addition, differentiated eosinophils expressed both isoforms of the IL-33 receptor, ST2L and s ST2 throughout the differentiation process. Transcript levels of both IL-33 receptors were up-regulated by treatment with IL-33 at earlier timepoints in the differentiation. These cells also expressed IL-4 and IL-13 mRNA which were up-regulated by IL-33 as well. Notably, IL-13 expression was significantly higher with IL-33 treatment compared to media control at every timepoint measured. IL-33 significantly increased cellular secretion of IL-13 protein at most timepoints throughout differentiation. IL-8, LIF, CCL1, CCL5, CCL7, and CCL8 were also significantly secreted after IL-33 stimulation.ConclusionsOur findings suggest that CD34 differentiated eosinophils are morphologically and phenotypically similar to peripheral eosinophils. The release of specific cytokines in direct response to IL-33 may contribute to the pathogenesis of type 2 inflammation and facilitates new avenues for studying eosinophils as effector cells in vitro .

Muscle power assessment entails the use of complex equipment which impacts its clinical applicability. Recently, equations to estimate lower-limb muscle power measures based on 5-repetition sit-to-stand (5STS) performance and anthropometric parameters were validated. However, their ability to discriminate physical performance status in older adults is still unknown. Moreover, the analysis of the biomechanical aspects of 5STS might represent a valid instrument to identify people with different physical statuses. Explore and examine the biomechanical aspects of 5STS performance, and compare the capacity of this measure and 5STS muscle power equations to discriminate older women with different physical function levels. Cross-sectional study. Setting: Community. Participants: Older women. Measurements: 5STS using a linear encoder, Timed “Up-andGo” (TUG), isometric handgrip strength (IHG) and walking speed (WS). Results from ANOVA analysis indicated that peak concentric muscle power was reached in the first 5STS repetition and then declined significantly (P=0.006). When participants were divided in high and low physical performance groups according to median results of TUG, IHG and WS tests, significant differences in 5STS biomechanical aspects were observed, according to independent t-test results (P<0.05). However, no differences were found for 5STS muscle power equations. Pearson's correlation analysis indicated that 5STS biomechanical aspects (P<0.05), but not 5STS muscle power equations, were significantly associated with physical performance. Findings of the present study suggest that 5STS biomechanical aspects might contribute to discriminating older women with high and low physical performance.