Giant thermal Hall conductivity in the pseudogap phase of cuprate superconductors.

The nature of the pseudogap phase of the copper oxides ('cuprates') remains a puzzle. Although there are indications that this phase breaks various symmetries, there is no consensus on its fundamental nature1. Fermi-surface, transport and thermodynamic signatures of the pseudogap phase are reminiscent of a transition into a phase with antiferromagnetic order, but evidence for an associated long-range magnetic order is still lacking2. Here we report measurements of the thermal Hall conductivity (in the x-y plane, κxy) in the normal state of four different cuprates-La1.6-xNd0.4SrxCuO4, La1.8-xEu0.2SrxCuO4, La2-xSrxCuO4 and Bi2Sr2-xLaxCuO6+δ. We show that a large negative κxy signal is a property of the pseudogap phase, appearing at its critical hole doping, p*. It is also a property of the Mott insulator at p ≈ 0, where κxy has the largest reported magnitude of any insulator so far3. Because this negative κxy signal grows as the system becomes increasingly insulating electrically, it cannot be attributed to conventional mobile charge carriers. Nor is it due to magnons, because it exists in the absence of magnetic order. Our observation is reminiscent of the thermal Hall conductivity of insulators with spin-liquid states4-6, pointing to neutral excitations with spin chirality7 in the pseudogap phase of cuprates.

Thermodynamic signatures of quantum criticality in cuprate superconductors.

The three central phenomena of cuprate (copper oxide) superconductors are linked by a common doping level p*-at which the enigmatic pseudogap phase ends and the resistivity exhibits an anomalous linear dependence on temperature, and around which the superconducting phase forms a dome-shaped area in the phase diagram1. However, the fundamental nature of p* remains unclear, in particular regarding whether it marks a true quantum phase transition. Here we measure the specific heat C of the cuprates Eu-LSCO and Nd-LSCO at low temperature in magnetic fields large enough to suppress superconductivity, over a wide doping range2 that includes p*. As a function of doping, we find that Cel/T is strongly peaked at p* (where Cel is the electronic contribution to C) and exhibits a log(1/T) dependence as temperature T tends to zero. These are the classic thermodynamic signatures of a quantum critical point3-5, as observed in heavy-fermion6 and iron-based7 superconductors at the point where their antiferromagnetic phase comes to an end. We conclude that the pseudogap phase of cuprates ends at a quantum critical point, the associated fluctuations of which are probably involved in d-wave pairing and the anomalous scattering of charge carriers.

A spin-orbital-entangled quantum liquid on a honeycomb lattice.

The honeycomb lattice is one of the simplest lattice structures. Electrons and spins on this simple lattice, however, often form exotic phases with non-trivial excitations. Massless Dirac fermions can emerge out of itinerant electrons, as demonstrated experimentally in graphene, and a topological quantum spin liquid with exotic quasiparticles can be realized in spin-1/2 magnets, as proposed theoretically in the Kitaev model. The quantum spin liquid is a long-sought exotic state of matter, in which interacting spins remain quantum-disordered without spontaneous symmetry breaking. The Kitaev model describes one example of a quantum spin liquid, and can be solved exactly by introducing two types of Majorana fermion. Realizing a Kitaev model in the laboratory, however, remains a challenge in materials science. Mott insulators with a honeycomb lattice of spin-orbital-entangled pseudospin-1/2 moments have been proposed, including the 5d-electron systems α-Na2IrO3 (ref. 5) and α-Li2IrO3 (ref. 6) and the 4d-electron system α-RuCl3 (ref. 7). However, these candidates were found to magnetically order rather than form a liquid at sufficiently low temperatures, owing to non-Kitaev interactions. Here we report a quantum-liquid state of pseudospin-1/2 moments in the 5d-electron honeycomb compound H3LiIr2O6. This iridate does not display magnetic ordering down to 0.05 kelvin, despite an interaction energy of about 100 kelvin. We observe signatures of low-energy fermionic excitations that originate from a small number of spin defects in the nuclear-magnetic-resonance relaxation and the specific heat. We therefore conclude that H3LiIr2O6 is a quantum spin liquid. This result opens the door to finding exotic quasiparticles in a strongly spin-orbit-coupled 5d-electron transition-metal oxide.

Nonmagnetic J=0 State and Spin-Orbit Excitations in K_{2}RuCl_{6}.

Spin-orbit Mott insulators composed of t_{2g}^{4} transition metal ions may host excitonic magnetism due to the condensation of spin-orbital J=1 triplons. Prior experiments suggest that the 4d antiferromagnet Ca_{2}RuO_{4} embodies this notion, but a J=0 nonmagnetic state as a basis of the excitonic picture remains to be confirmed. We use Ru L_{3}-edge resonant inelastic x-ray scattering to reveal archetypal J multiplets with a J=0 ground state in the cubic compound K_{2}RuCl_{6}, which are well described within the LS-coupling scheme. This result highlights the critical role of unquenched orbital moments in 4d-electron compounds and calls for investigations of quantum criticality and excitonic magnetism on various crystal lattices.

Spin waves and spin-state transitions in a ruthenate high-temperature antiferromagnet.

Ruthenium compounds serve as a platform for fundamental concepts such as spin-triplet superconductivity1, Kitaev spin liquids2-5 and solid-state analogues of the Higgs mode in particle physics6,7. However, basic questions about the electronic structure of ruthenates remain unanswered, because several key parameters (including Hund's coupling, spin-orbit coupling and exchange interactions) are comparable in magnitude and their interplay is poorly understood, partly due to difficulties in synthesizing large single crystals for spectroscopic experiments. Here we introduce a resonant inelastic X-ray scattering (RIXS)8,9 technique capable of probing collective modes in microcrystals of 4d electron materials. We observe spin waves and spin-state transitions in the honeycomb antiferromagnet SrRu2O6 (ref. 10) and use the extracted exchange interactions and measured magnon gap to explain its high Néel temperature11-16. We expect that the RIXS method presented here will enable momentum-resolved spectroscopy of a large class of 4d transition-metal compounds.

High-Temperature Charge-Stripe Correlations in La_{1.675}Eu_{0.2}Sr_{0.125}CuO_{4}.

We use resonant inelastic x-ray scattering to investigate charge-stripe correlations in La_{1.675}Eu_{0.2}Sr_{0.125}CuO_{4}. By differentiating elastic from inelastic scattering, it is demonstrated that charge-stripe correlations precede both the structural low-temperature tetragonal phase and the transport-defined pseudogap onset. The scattering peak amplitude from charge stripes decays approximately as T^{-2} towards our detection limit. The in-plane integrated intensity, however, remains roughly temperature independent. Therefore, although the incommensurability shows a remarkably large increase at high temperature, our results are interpreted via a single scattering constituent. In fact, direct comparison to other stripe-ordered compounds (La_{1.875}Ba_{0.125}CuO_{4}, La_{1.475}Nd_{0.4}Sr_{0.125}CuO_{4}, and La_{1.875}Sr_{0.125}CuO_{4}) suggests a roughly constant integrated scattering intensity across all these compounds. Our results therefore provide a unifying picture for the charge-stripe ordering in La-based cuprates. As charge correlations in La_{1.675}Eu_{0.2}Sr_{0.125}CuO_{4} extend beyond the low-temperature tetragonal and pseudogap phase, their emergence heralds a spontaneous symmetry breaking in this compound.

Efficacy and safety of dupilumab in Japanese adults with moderate-to-severe atopic dermatitis: a subanalysis of three clinical trials.

BACKGROUND: Dupilumab, a human monoclonal antibody, blocks the shared receptor unit for interleukin-4 and interleukin-13. International phase II and III studies have evaluated the efficacy and safety of dupilumab in adults with moderate-to-severe atopic dermatitis (AD), but the effects of dupilumab in Japanese patients have not been reported. OBJECTIVES: To evaluate the efficacy and safety of dupilumab in Japanese patients with moderate-to-severe AD. METHODS: We analysed the efficacy and safety of dupilumab in the Japanese cohorts of a 16-week, phase IIb dose-finding trial (AD-1021; NCT01859988); a 16-week, phase III, placebo-controlled monotherapy trial (LIBERTY AD SOLO 1; NCT02277743) and a 52-week, phase III, placebo-controlled study of dupilumab with topical corticosteroids (LIBERTY AD CHRONOS; NCT02260986). RESULTS: Twenty-seven, 106 and 117 Japanese patients were enrolled in AD-1021, SOLO 1 and CHRONOS, respectively. Baseline disease severity was numerically higher in the Japanese cohort than in the overall study population. Generally, dupilumab significantly improved signs and symptoms of AD, including pruritus and patient quality of life, compared with placebo in the Japanese cohort, consistent with the overall study population. The combined safety profile of dupilumab in the Japanese cohort was similar to that in the total study populations; dupilumab was associated with an increased incidence of injection-site reactions and conjunctivitis compared with placebo. Dupilumab was associated with rapid reduction in thymus and activation-regulated chemokine and gradual IgE reductions. CONCLUSIONS: Dupilumab alone or with topical corticosteroids improved signs and symptoms of AD, had an acceptable safety profile, and suppressed biomarkers of type 2 inflammation compared with placebo in Japanese adult patients with moderate-to-severe AD. What's already known about this topic? Differences in atopic dermatitis (AD) pathology have been reported between Asian and Western populations, in which distinct helper T-cell activation profiles have been observed. International clinical studies in adults with moderate-to-severe AD have evaluated the efficacy and safety of dupilumab, which blocks interleukin-4 and interleukin-13, key molecules in type 2 inflammation. The effects of dupilumab in Japanese patients specifically have not yet been reported. What does this study add? Dupilumab alone or with topical corticosteroids improved signs and symptoms of AD and had an acceptable safety profile compared with placebo in Japanese patients with moderate-to-severe AD. The effects were comparable with those observed in the overall study population. Reported immunological differences in AD pathology in Asian patients may be secondary to type 2 immune activation.

Mortality after transcatheter versus surgical aortic valve replacement: an updated meta-analysis of randomised trials.

BACKGROUND: To determine whether transcatheter aortic valve implantation (TAVI) improves early (30-day) and midterm (1-year) mortality compared with surgical aortic valve replacement (SAVR), we performed an updated meta-analysis of all the currently available randomised controlled trials (RCTs). METHODS: To identify all RCTs providing both 30-day and 1­year mortality after TAVI versus SAVR, PubMed and ClinicalTrials.gov were searched up to and including July 2019. A risk difference (RD) and its 95% confidence interval were generated using data of prespecified outcomes in both the TAVI and SAVR groups. Study-specific estimates were pooled using inverse variance-weighted averages of RDs in the random-effects model. RESULTS: We identified seven eligible high-quality RCTs including a total of 7631 as-treated patients. Pooled analyses demonstrated significantly lower 30-day (RD -0.60%; p = 0.046) and 1­year all-cause mortality (RD -1.12%; p = 0.03) after TAVI than after SAVR. No funnel plot asymmetry was detected for 30-day and 1­year mortality. Meta-regression analyses indicated that RDs of 30-day and 1­year mortality between TAVI and SAVR were not modulated by mean Society of Thoracic Surgeons Predicted Risk of Mortality score. Bleeding complications at 30 days and 1 year and stage 2/3 acute kidney injury at 30 days were significantly less frequent after TAVI than after SAVR, whereas major vascular complications and new permanent pacemaker implantation at 30 days and 1 year were significantly more frequent after TAVI than after SAVR. CONCLUSION: The best evidence from the present meta-analysis of all the currently available RCTs suggests that TAVI may reduce 30-day and 1­year all-cause mortality compared with SAVR.

Novel developments in non-invasive imaging of peripheral arterial disease with CT: experience with state-of-the-art, ultra-high-resolution CT and subtraction imaging.

Despite advances, challenges remain for less invasive imaging of peripheral arterial occlusive disease (PAOD) using computed tomography (CT) angiography. The application of dual-energy imaging to PAOD has been reported to improve the diagnostic accuracy of this application; however, severe arteriosclerosis with heavy arterial wall calcification still hampers definitive lesion characterisation, especially in distal and smaller arteries. Recently an ultra-high resolution scanner has been introduced. In combination with advances in post-processing, such as subtraction techniques, these developments may overcome some of the current challenges and allow far more detailed characterisation of PAOD non-invasively. The aim of this review is to describe our current experience with ultra-high resolution CT in combination with subtraction and discuss the potential advantages of their application for peripheral angiography.

Endogenous protein and enzyme fragments induce immunoglobulin E-independent activation of mast cells via a G protein-coupled receptor, MRGPRX2.

Mast cells play a central role in inflammatory and allergic reactions by releasing inflammatory mediators through 2 main pathways, immunoglobulin E-dependent and E-independent activation. In the latter pathway, mast cells are activated by a diverse range of basic molecules (collectively known as basic secretagogues) through Mas-related G protein-coupled receptors (MRGPRs). In addition to the known basic secretagogues, here, we discovered several endogenous protein and enzyme fragments (such as chaperonin-10 fragment) that act as bioactive peptides and induce immunoglobulin E-independent mast cell activation via MRGPRX2 (previously known as MrgX2), leading to the degranulation of mast cells. We discuss the possibility that MRGPRX2 responds various as-yet-unidentified endogenous ligands that have specific characteristics, and propose that MRGPRX2 plays an important role in regulating inflammatory responses to endogenous harmful stimuli, such as protein breakdown products released from damaged or dying cells.

Three-Dimensional Fermi Surface of Overdoped La-Based Cuprates.

We present a soft x-ray angle-resolved photoemission spectroscopy study of overdoped high-temperature superconductors. In-plane and out-of-plane components of the Fermi surface are mapped by varying the photoemission angle and the incident photon energy. No k_{z} dispersion is observed along the nodal direction, whereas a significant antinodal k_{z} dispersion is identified for La-based cuprates. Based on a tight-binding parametrization, we discuss the implications for the density of states near the van Hove singularity. Our results suggest that the large electronic specific heat found in overdoped La_{2-x}Sr_{x}CuO_{4} cannot be assigned to the van Hove singularity alone. We therefore propose quantum criticality induced by a collapsing pseudogap phase as a plausible explanation for observed enhancement of electronic specific heat.

Elevated serum eosinophil cationic protein and transforming growth factor-α levels in a patient with pemphigus vegetans.

Pemphigus vegetans (PVeg) is a rare variant of pemphigus, characterized by vegetating lesions mainly with antidesmoglein 3 antibodies. However, the pathomechanisms for PVeg is still unknown. We present a patient with PVeg mainly associated with antidesmocollin (Dsc)3 antibodies, who originally developed pemphigus foliaceus. Serum levels of eosinophil cationic protein and transforming growth factor (TGF)-α increased at the onset of PVeg in this patient. Thus, TGF-α might be involved in the formation of vegetating lesions in PVeg.

Engineering a Spin-Orbital Magnetic Insulator by Tailoring Superlattices.

In 5d Ir oxides with an interplay of spin-orbit coupling and electron correlations, we have tailored a spin-orbital magnetic insulator out of a semimetal SrIrO(3) by tuning the structure through superlattices [(SrIrO(3))(m), SrTiO(3)] (m=1,2,3,4, and ∞). We observed the systematic decrease of the magnetic ordering temperature and the resistivity as a function of m. The transition from the semimetal to the insulator is found to be closely linked to the appearance of magnetism at m≃3. Long range magnetic ordering was realized even in the m=1 single layer superlattice, implying that the design and realization of novel electronic phases is feasible at the level of a single atomic layer in complex Ir oxides.

Hyperhoneycomb Iridate ß-Li2IrO3 as a platform for Kitaev magnetism.

A complex iridium oxide ß-Li(2)IrO(3) crystallizes in a hyperhoneycomb structure, a three-dimensional analogue of honeycomb lattice, and is found to be a spin-orbital Mott insulator with J(eff)=1/2 moment. Ir ions are connected to the three neighboring Ir ions via Ir-O(2)-Ir bonding planes, which very likely gives rise to bond-dependent ferromagnetic interactions between the J(eff)=1/2 moments, an essential ingredient of Kitaev model with a spin liquid ground state. Dominant ferromagnetic interaction between J(eff)=1/2 moments is indeed confirmed by the temperature dependence of magnetic susceptibility χ(T) which shows a positive Curie-Weiss temperature θ(CW)∼+40 K. A magnetic ordering with a very small entropy change, likely associated with a noncollinear arrangement of J(eff)=1/2 moments, is observed at T(c)=38 K. With the application of magnetic field to the ordered state, a large moment of more than 0.35 µ(B)/Ir is induced above 3 T, a substantially polarized J(eff)=1/2 state. We argue that the close proximity to ferromagnetism and the presence of large fluctuations evidence that the ground state of hyperhoneycomb ß-Li(2)IrO(3) is located in close proximity of a Kitaev spin liquid.

Efficacy and Safety of Lixisenatide in Japanese Patients with Type 2 Diabetes Insufficiently Controlled with Basal Insulin±Sulfonylurea: A Subanalysis of the GetGoal-L-Asia Study.

The aim of the study was to evaluate the efficacy and safety of once-daily lixisenatide 20 µg as add-on to basal insulin with or without sulfonylurea in Asian patients with type 2 diabetes mellitus. The study as a subanalysis of the 159 Japanese patients from the 24-week double-blind GetGoal-L-Asia study (NCT00866658) who received once-daily lixisenatide or placebo. The primary endpoint was change from baseline in HbA1c evaluated using analysis of covariance. Once-daily lixisenatide significantly reduced mean HbA1c [least squares mean difference vs. placebo - 1.1% (- 12 mmol/mol); p<0.0001]. Significantly more patients in the lixisenatide group reached HbA1c targets of < 7% (53 mmol/mol; 31.4 vs. 2.3% for placebo; p<0.0001) and ≤ 6.5% (48 mmol/mol; 12.9 vs. 1.2% for placebo; p=0.0028). Lixisenatide significantly reduced 2-h postprandial plasma glucose (least squares mean difference vs. placebo-8.64 mmol/l; p<0.0001), glucose excursion (least squares mean difference vs. placebo - 7.80 mmol/l; p<0.0001) and fasting plasma glucose (least squares mean difference vs. placebo - 0.96 mmol/l; p=0.0126). Body weight was reduced with lixisenatide but with no significant difference vs. placebo. Gastrointestinal adverse events were more frequent with lixisenatide (61.1 vs. 11.5% for placebo) but were generally transient and mild-to-moderate in intensity. The incidence of symptomatic hypoglycemia was 39.0 vs. 13.5% in patients receiving sulfonylureas and 32.3 vs. 22.9% in those not receiving sulfonylureas, for lixisenatide and placebo, respectively. In Japanese patients with type 2 diabetes mellitus, once-daily lixisenatide was well tolerated and led to significant and clinically relevant improvement in glycemic control, with a pronounced effect on postprandial plasma glucose.

Enhancement of the Nernst effect by stripe order in a high-T(c) superconductor.

The Nernst effect in metals is highly sensitive to two kinds of phase transition: superconductivity and density-wave order. The large, positive Nernst signal observed in hole-doped high-T(c) superconductors above their transition temperature (T(c)) has so far been attributed to fluctuating superconductivity. Here we report that in some of these materials the large Nernst signal is in fact the result of stripe order, a form of spin/charge modulation that causes a reconstruction of the Fermi surface. In La(2-x)Sr(x)CuO(4) (LSCO) doped with Nd or Eu, the onset of stripe order causes the Nernst signal to change from being small and negative to being large and positive, as revealed either by lowering the hole concentration across the quantum critical point in Nd-doped LSCO (refs 6-8) or by lowering the temperature across the ordering temperature in Eu-doped LSCO (refs 9, 10). In the second case, two separate peaks are resolved, respectively associated with the onset of stripe order at high temperature and superconductivity near T(c).

A large ovarian leiomyoma discovered incidentally in a 76-year-old woman: case report.

BACKGROUND: Ovarian leiomyoma is very rare type of ovarian tumor. This benign tumor is seen in the pediatric age group to premenopausal women. CASE: A 76-year-old woman had a huge leiomyoma (19 x 11 x 10 cm) of the right ovary. The preoperative diagnosis was difficult to distinguish from a broad ligament leiomyoma or ovarian cancer. CONCLUSIONS: Although theses tumors are benign, its extreme rarity led us to report an additional and rather unusual case of ovarian leiomyoma, and to focus some attention on this type of tumor.

Electronic structure of a quasi-freestanding MoS2 monolayer.

Several transition-metal dichalcogenides exhibit a striking crossover from indirect to direct band gap semiconductors as they are thinned down to a single monolayer. Here, we demonstrate how an electronic structure characteristic of the isolated monolayer can be created at the surface of a bulk MoS2 crystal. This is achieved by intercalating potassium in the interlayer van der Waals gap, expanding its size while simultaneously doping electrons into the conduction band. Our angle-resolved photoemission measurements reveal resulting electron pockets centered at the K̅ and K' points of the Brillouin zone, providing the first momentum-resolved measurements of how the conduction band dispersions evolve to yield an approximately direct band gap of ∼1.8 eV in quasi-freestanding monolayer MoS2. As well as validating previous theoretical proposals, this establishes a novel methodology for manipulating electronic structure in transition-metal dichalcogenides, opening a new route for the generation of large-area quasi-freestanding monolayers for future fundamental study and use in practical applications.

Premenstrual syndrome: management and pathophysiology.

Premenstrual syndrome (PMS) is triggered by hormonal events ensuing after ovulation. The symptoms can begin in the early, mid, or late luteal phase and are not associated with defined concentrations of any specific gonadal or non-gonadal hormone. Women with PMS experience affective or somatic symptoms that cause severe dysfunction in social or occupational realms. Although evidence for a hormonal abnormality has not been established, the symptoms of the premenopausal disorders are related to the production of progesterone by the ovary. The progesterone metabolites may bind to a neurosteroid-binding site on the membrane of the neurotransmitters. Thus, ovulation suppression is an area of focus for diagnostic and treatment options. Many treatment studies have focused on suppression of ovulation with gonadotropin-releasing hormone analogs (GnRHa), high doses of transdermal estrogen, and bilateral oophorectomy all have positive evidence as treatment options for prevention of PMS. However, because of these limitations and their substantial intensive care, these do not appear to be appropriate methods for conventional treatment of PMS. Serotonergic antidepressants, selective serotonin reuptake inhibitors, are well-established, highly effective, and first-line pharmacologic therapy.