Surface states of three-dimensional topological insulators exhibit the phenomenon of spin–momentum locking, whereby the orientation of an electron spin is determined by its momentum. Probing the spin ...texture of these states is of critical importance for the realization of topological insulator devices, but the main technique currently available is spin- and angle-resolved photoemission spectroscopy. Here we reveal a close link between the spin texture and a new kind of magnetoresistance, which depends on the relative orientation of the current with respect to the magnetic field as well as the crystallographic axes, and scales linearly with both the applied electric and magnetic fields. This bilinear magnetoelectric resistance can be used to map the spin texture of topological surface states by simple transport measurements. For a prototypical Bi2Se3 single layer, we can map both the in-plane and out-of-plane components of the spin texture (the latter arising from hexagonal warping). Theoretical calculations suggest that the bilinear magnetoelectric resistance originates from conversion of a non-equilibrium spin current into a charge current under application of the external magnetic field.
Summary
Background While the chronic inflammation related to autoimmune diseases is known to be associated with an increased cardiovascular risk, much less is known about cerebrovascular risks.
...Objectives The present population‐based, age‐ and sex‐matched follow‐up study was undertaken to investigate the risks of acute myocardial infarction (AMI) and ischaemic stroke in patients with dermatomyositis (DMS).
Methods In total 907 patients with DMS were enrolled and compared with a non‐DMS control group consisting of 4535 age‐ and sex‐matched, randomly sampled subjects without DMS. The AMI‐free and ischaemic stroke‐free survival curves were generated using the Kaplan–Meier method. Cox proportional hazard regression was used to estimate the DMS‐associated risks of AMI and ischaemic stroke.
Results During the 2‐year follow‐up period, 14 patients with DMS (1·5%) and 18 patients in the non‐DMS control group (0·4%) suffered AMIs. The crude hazard ratio (HR) for suffering an AMI in patients with DMS compared with subjects in the non‐DMS group was 3·96 95% confidence interval (CI) 1·97–7·96, P = 0·0001, while the adjusted HR was 3·37 (95% CI 1·67–6·80, P = 0·0007), after taking into account demographic characteristics and cardiovascular comorbidities. During the same follow‐up period, 46 patients (5·1%) and 133 subjects in the control group (2·9%) developed ischaemic strokes. The crude HR for developing an ischaemic stroke in patients with DMS compared with subjects in the non‐DMS group was 1·78 (95% CI 1·27–2·49, P = 0·0007), and the adjusted HR was 1·67 (95% CI, 1·19–2·34, P = 0·0028).
Conclusions These findings suggest that DMS is associated with an increased risk of cardiovascular and cerebrovascular events.
What’s already known about this topic?
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Connective‐tissue disorders, such as rheumatoid arthritis, Sjögren syndrome, systemic lupus erythematosus and primary vasculitis have been linked to an increased risk of cardiovascular disease.
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Data on any association between dermatomyositis and cardiovascular or cerebrovascular disease is sparse.
What does this study add?
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This population‐based, age‐ and sex‐matched longitudinal follow‐up study shows that dermatomyositis is associated with increased risks of acute myocardial infarction and ischaemic stroke.
Very few studies have explored the temporal relationship between hypertension and trigeminal neuralgia (TN). The aim of this population-based follow-up study was to investigate whether hypertension ...is associated with a higher risk of developing TN.
A total of 138,492 persons with at least 2 ambulatory visits with the principal diagnosis of hypertension in 2001 were enrolled in the hypertension group. The nonhypertension group consisted of 276,984 age- and sex-matched, randomly sampled subjects without hypertension. The 3-year TN-free survival rate and the cumulative incidence of TN were calculated using the Kaplan-Meier method. Cox proportional hazard regression was used to estimate the hazard ratio of TN.
In the hypertension group, 121 patients developed TN during follow-up, while, in the nonhypertension group, 167 subjects developed TN. The crude hazard ratio for the hypertension group was 1.52 (95% confidence interval CI 1.20-1.92; p = 0.0005), while, after adjustment for demographic characteristics and medical comorbidities, the adjusted hazard ratio was 1.51 (95% CI 1.19-1.90; p = 0.0006).
This study shows a significantly increased risk of developing TN after hypertension. Further studies are needed to elucidate the underlying mechanism of the association between hypertension and TN.
One favorable situation for spins to enter the long-sought quantum spin liquid (QSL) state is when they sit on a kagome lattice. No consensus has been reached in theory regarding the true ground ...state of this promising platform. The experimental efforts, relying mostly on one archetypal material ZnCu_{3}(OH)_{6}Cl_{2}, have also led to diverse possibilities. Apart from subtle interactions in the Hamiltonian, there is the additional degree of complexity associated with disorder in the real material ZnCu_{3}(OH)_{6}Cl_{2} that haunts most experimental probes. Here we resort to heat transport measurement, a cleaner probe in which instead of contributing directly, the disorder only impacts the signal from the kagome spins. For ZnCu_{3}(OH)_{6}Cl_{2}, we observed no contribution by any spin excitation nor obvious field-induced change to the thermal conductivity. These results impose strong constraints on various scenarios about the ground state of this kagome compound: while certain quantum paramagnetic states other than a QSL may serve as natural candidates, a QSL state, gapless or gapped, must be dramatically modified by the disorder so that the kagome spin excitations are localized.
A sub‐population of chemoresistant cells exhibits biological properties similar to cancer stem cells (CSCs), and these cells are believed to be a main cause for tumor relapse and metastasis. In our ...study, we explored the role of SOX8 and its molecular mechanism in the regulation of the stemness properties and the epithelial mesenchymal transition (EMT) of cisplatin‐resistant tongue squamous cell carcinoma (TSCC) cells. We found that SOX8 was upregulated in cisplatin‐resistant TSCC cells, which displayed CSC‐like properties and exhibited EMT. SOX8 was also overexpressed in chemoresistant patients with TSCC and was associated with higher lymph node metastasis, advanced tumor stage and shorter overall survival. Stable knockdown of SOX8 in cisplatin‐resistant TSCC cells inhibited chemoresistance, tumorsphere formation, and EMT. The Wnt/β‐catenin pathway mediated the cancer stem‐like properties in cisplatin‐resistant TSCC cells. Further studies showed that the transfection of active β‐catenin in SOX8 stable‐knockdown cells partly rescued the SOX8 silencing‐induced repression of stem‐like features and chemoresistance. Through chromatin immunoprecipitation and luciferase assays, we observed that SOX8 bound to the promoter region of Frizzled‐7 (FZD7) and induced the FZD7‐mediated activation of the Wnt/β‐catenin pathway. In summary, SOX8 confers chemoresistance and stemness properties and mediates EMT processes in chemoresistant TSCC via the FZD7‐mediated Wnt/β‐catenin pathway.
What's new?
Tongue cancer frequently spreads to the lymph nodes, and while chemotherapy with cisplatin has improved 5‐year survival rates, all too often the cancer becomes resistant to chemotherapy and returns. Here, the authors show that tongue squamous cell carcinoma (TSCC) cells that have acquired cisplatin resistance express more SOX‐8 mRNA than their parent TSCC cells. Getting rid of SOX‐8, they showed, hampered the cells' chemoresistance as well as the epithelial to mesenchymal transition. Adding active beta‐catenin to the cells lacking SOX‐8 partially restored these properties, showing that SOX‐8 acts through the Wnt/beta‐catenin pathway.
Since the mid-20th century, nitrogen (N) deposition has shown an increasing trend in the Tibetan Plateau (TP), where alpine ecosystems are sensitive to elevated N deposition. However, the ...quantitative characterization of N deposition in the TP remains unclear, due in most part to the lack of in situ measurement. Using the Tibetan Observation and Research Platform network, we conducted short-term in situ measurements of major ions (NO3−, Cl−, SO42−, NH4+, Na+, K+, Ca2+, and Mg2+) wet deposition at five remote sites in the TP during 2011–2013. At Southeast Tibet Station, Nam Co Station, Qomolangma Station, Ngari Station, and Muztagh Ata Station, the NH4+–N wet deposition was 0.63, 0.68, 0.92, 0.36, and 1.25 kg N ha−1 yr−1, respectively; the NO3−–N wet deposition was 0.28, 0.24, 0.03, 0.08, and 0.30 kg N ha−1 yr−1, respectively; and the inorganic N wet deposition was 0.91, 0.92, 0.94, 0.44, and 1.55 kg N ha−1 yr−1, respectively. The inorganic N wet deposition mainly occurred in the form of NH4+–N during summer at all sites. Results of enrichment factor analysis and principal component analysis demonstrated that both NH4+–N and NO3−–N wet deposition in the TP were mainly influenced by anthropogenic activities. Backward trajectory analysis showed that the inorganic N deposition at Muztagh Ata Station was mainly transported from central Asia and the Middle East through westerlies. At Southeast Tibet Station, Nam Co Station, Qomolangma Station, and Ngari Station, the inorganic N deposition was mainly contributed by anthropogenic sources in south Asia, and was mainly transported by the Indian monsoon. Combining site-scale in situ measurements of inorganic N wet deposition in this and previous studies, the average wet deposition of atmospheric NH4+–N, NO3−–N, and inorganic N in the TP was estimated to be 1.06, 0.51, and 1.58 kg N ha−1 yr−1, respectively. The average NH4+–N : NO3−–N ratio in precipitation in the TP was approximately 2 : 1. Results from the present study suggest that earlier estimations based on chemical transport model simulations and/or limited field measurements likely overestimated substantially the regional inorganic N wet deposition in the TP. To clarify the total N deposition in the TP more clearly, it is essential to conduct long-term monitoring of both wet and dry deposition of atmospheric N in various climate zones in the TP in the future.
IMPORTANCE: The influence of menopausal hormone therapy on breast cancer remains unsettled with discordant findings from observational studies and randomized clinical trials. OBJECTIVE: To assess the ...association of prior randomized use of estrogen plus progestin or prior randomized use of estrogen alone with breast cancer incidence and mortality in the Women’s Health Initiative clinical trials. DESIGN, SETTING, AND PARTICIPANTS: Long-term follow-up of 2 placebo-controlled randomized clinical trials that involved 27 347 postmenopausal women aged 50 through 79 years with no prior breast cancer and negative baseline screening mammogram. Women were enrolled at 40 US centers from 1993 to 1998 with follow-up through December 31, 2017. INTERVENTIONS: In the trial involving 16 608 women with a uterus, 8506 were randomized to receive 0.625 mg/d of conjugated equine estrogen (CEE) plus 2.5 mg/d of medroxyprogesterone acetate (MPA) and 8102, placebo. In the trial involving 10 739 women with prior hysterectomy, 5310 were randomized to receive 0.625 mg/d of CEE alone and 5429, placebo. The CEE-plus-MPA trial was stopped in 2002 after 5.6 years’ median intervention duration, and the CEE-only trial was stopped in 2004 after 7.2 years’ median intervention duration. MAIN OUTCOMES AND MEASURES: The primary outcome was breast cancer incidence (protocol prespecified primary monitoring outcome for harm) and secondary outcomes were deaths from breast cancer and deaths after breast cancer. RESULTS: Among 27 347 postmenopausal women who were randomized in both trials (baseline mean SD age, 63.4 years 7.2 years), after more than 20 years of median cumulative follow-up, mortality information was available for more than 98%. CEE alone compared with placebo among 10 739 women with a prior hysterectomy was associated with statistically significantly lower breast cancer incidence with 238 cases (annualized rate, 0.30%) vs 296 cases (annualized rate, 0.37%; hazard ratio HR, 0.78; 95% CI, 0.65-0.93; P = .005) and was associated with statistically significantly lower breast cancer mortality with 30 deaths (annualized mortality rate, 0.031%) vs 46 deaths (annualized mortality rate, 0.046%; HR, 0.60; 95% CI, 0.37-0.97; P = .04). In contrast, CEE plus MPA compared with placebo among 16 608 women with a uterus was associated with statistically significantly higher breast cancer incidence with 584 cases (annualized rate, 0.45%) vs 447 cases (annualized rate, 0.36%; HR, 1.28; 95% CI, 1.13-1.45; P < .001) and no significant difference in breast cancer mortality with 71 deaths (annualized mortality rate, 0.045%) vs 53 deaths (annualized mortality rate, 0.035%; HR, 1.35; 95% CI, 0.94-1.95; P= .11). CONCLUSIONS AND RELEVANCE: In this long-term follow-up study of 2 randomized trials, prior randomized use of CEE alone, compared with placebo, among women who had a previous hysterectomy, was significantly associated with lower breast cancer incidence and lower breast cancer mortality, whereas prior randomized use of CEE plus MPA, compared with placebo, among women who had an intact uterus, was significantly associated with a higher breast cancer incidence but no significant difference in breast cancer mortality.
We report on the synthesis of a phase-pure, 2-dimensional transition metal carbide Nb4C3, produced by immersing Nb4AlC3 powders in hydrofluoric acid. The structure of this, only second MXene with ...formula M4X3, was investigated with pair distribution function analysis. The resistivity of a cold-pressed disc was 0.0046 Ω m, rendering this MXene one of the most conductive to date.
Time-domain science has undergone a revolution over the past decade, with tens of thousands of new supernovae (SNe) discovered each year. However, several observational domains, including SNe within ...days or hours of explosion and faint, red transients, are just beginning to be explored. Here we present the Young Supernova Experiment (YSE), a novel optical time-domain survey on the Pan-STARRS telescopes. Our survey is designed to obtain well-sampled griz light curves for thousands of transient events up to z 0.2. This large sample of transients with four-band light curves will lay the foundation for the Vera C. Rubin Observatory and the Nancy Grace Roman Space Telescope, providing a critical training set in similar filters and a well-calibrated low-redshift anchor of cosmologically useful SNe Ia to benefit dark energy science. As the name suggests, YSE complements and extends other ongoing time-domain surveys by discovering fast-rising SNe within a few hours to days of explosion. YSE is the only current four-band time-domain survey and is able to discover transients as faint as ∼21.5 mag in gri and ∼20.5 mag in z, depths that allow us to probe the earliest epochs of stellar explosions. YSE is currently observing approximately 750 deg2 of sky every 3 days, and we plan to increase the area to 1500 deg2 in the near future. When operating at full capacity, survey simulations show that YSE will find ∼5000 new SNe per year and at least two SNe within 3 days of explosion per month. To date, YSE has discovered or observed 8.3% of the transient candidates reported to the International Astronomical Union in 2020. We present an overview of YSE, including science goals, survey characteristics, and a summary of our transient discoveries to date.
An intriguing property of a three-dimensional (3D) topological insulator (TI) is the existence of surface states with spin-momentum locking, which offers a new frontier of exploration in spintronics. ...Here, we report the observation of a new type of Hall effect in a 3D TI Bi_{2}Se_{3} film. The Hall resistance scales linearly with both the applied electric and magnetic fields and exhibits a π/2 angle offset with respect to its longitudinal counterpart, in contrast to the usual angle offset of π/4 between the linear planar Hall effect and the anisotropic magnetoresistance. This novel nonlinear planar Hall effect originates from the conversion of a nonlinear transverse spin current to a charge current due to the concerted actions of spin-momentum locking and time-reversal symmetry breaking, which also exists in a wide class of noncentrosymmetric materials with a large span of magnitude. It provides a new way to characterize and utilize the nonlinear spin-to-charge conversion in a variety of topological quantum materials.
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