Transition-metal dichalcogenides (TMDs) are renowned for their rich and varied bulk properties, while their single-layer variants have become one of the most prominent examples of two-dimensional ...materials beyond graphene. Their disparate ground states largely depend on transition metal d-electron-derived electronic states, on which the vast majority of attention has been concentrated to date. Here, we focus on the chalcogen-derived states. From density-functional theory calculations together with spin- and angle-resolved photoemission, we find that these generically host a co-existence of type-I and type-II three-dimensional bulk Dirac fermions as well as ladders of topological surface states and surface resonances. We demonstrate how these naturally arise within a single p-orbital manifold as a general consequence of a trigonal crystal field, and as such can be expected across a large number of compounds. Already, we demonstrate their existence in six separate TMDs, opening routes to tune, and ultimately exploit, their topological physics.
The aim was to examine barriers to initiation and continuation of treatment among individuals with common mental disorders in the US general population.
Respondents in the National Comorbidity Survey ...Replication with common 12-month DSM-IV mood, anxiety, substance, impulse control and childhood disorders were asked about perceived need for treatment, structural barriers and attitudinal/evaluative barriers to initiation and continuation of treatment.
Low perceived need was reported by 44.8% of respondents with a disorder who did not seek treatment. Desire to handle the problem on one's own was the most common reason among respondents with perceived need both for not seeking treatment (72.6%) and for dropping out of treatment (42.2%). Attitudinal/evaluative factors were much more important than structural barriers both to initiating (97.4% v. 22.2%) and to continuing (81.9% v. 31.8%) of treatment. Reasons for not seeking treatment varied with illness severity. Low perceived need was a more common reason for not seeking treatment among individuals with mild (57.0%) than moderate (39.3%) or severe (25.9%) disorders, whereas structural and attitudinal/evaluative barriers were more common among respondents with more severe conditions.
Low perceived need and attitudinal/evaluative barriers are the major barriers to treatment seeking and staying in treatment among individuals with common mental disorders. Efforts to increase treatment seeking and reduce treatment drop-out need to take these barriers into consideration as well as to recognize that barriers differ as a function of sociodemographic and clinical characteristics.
Metallic transition-metal dichalcogenides (TMDCs) are benchmark systems for studying and controlling intertwined electronic orders in solids, with superconductivity developing from a charge-density ...wave state. The interplay between such phases is thought to play a critical role in the unconventional superconductivity of cuprates, Fe-based and heavy-fermion systems, yet even for the more moderately-correlated TMDCs, their nature and origins have proved controversial. Here, we study a prototypical example, 2H-NbSe2, by spin- and angle-resolved photoemission and first-principles theory. We find that the normal state, from which its hallmark collective phases emerge, is characterized by quasiparticles whose spin is locked to their valley pseudospin. This results from a combination of strong spin-orbit interactions and local inversion symmetry breaking, while interlayer coupling further drives a rich three-dimensional momentum dependence of the underlying Fermi-surface spin texture. These findings necessitate a re-investigation of the nature of charge order and superconducting pairing in NbSe2 and related TMDCs.
Enhanced recovery pathways have been shown to reduce length of stay without increasing readmission or complications in numerous areas of surgery. Uptake of gynecologic oncology ERAS guidelines has ...been limited. We describe the effect of ERAS guideline implementation in gynecologic oncology on length of stay, patient outcomes, and economic impact for a province-wide single-payer system.
We compared pre- and post-guideline implementation outcomes in consecutive staging and debulking patients at two centers that provide the majority of surgical gynecologic oncology care in Alberta, Canada between March 2016 and April 2017. Clinical outcomes and compliance were obtained using the ERAS Interactive Audit System. Patients were followed until 30 days after discharge. Negative binomial regression was employed to adjust for patient characteristics.
We assessed 152 pre-ERAS and 367 post-ERAS implementation patients. Mean compliance with ERAS care elements increased from 56% to 77.0% after implementation (p < 0.0001). Median length of stay for all surgeries decreased from 4.0 days to 3.0 days post-ERAS (p < 0.0001), which translated to an adjusted LOS decrease of 31.4% (95% CI = 21.7% - 39.9%, p < 0.0001). In medium/high complexity surgery median LOS was reduced by 2.0 days (p = 0.0005). Complications prior to discharge decreased from 53.3% to 36.2% post-ERAS (p = 0.0003). There was no significant difference in readmission (p = 0.6159), complications up to 30 days (p = 0.6274), or mortality (p = 0.3618) between the cohorts. The net cost savings per patient was $956 (95%CI: $162 to $1636).
Systematic implementation of ERAS gynecologic oncology guidelines across a healthcare system improves patient outcomes and saves resources.
•Implementation of ERAS gynecologic oncology guidelines results in significant clinical improvements and cost savings.•Use of an audit system allows measurement of compliance to the individual ERAS recommendations.•ERAS teams should strive to improve compliance to guidelines as this translates into improved outcomes.
Combined with measurements made by very-long-baseline interferometry, the observations of fast TeV gamma-ray flares probe the structure and emission mechanism of blazar jets. However, only a handful ...of such flares have been detected to date, and only within the last few years have these flares been observed from lower-frequency-peaked BL Lac objects and flat-spectrum radio quasars. We report on a fast TeV gamma-ray flare from the blazar BL Lacertae observed by the Very Energetic Radiation Imaging Telescope Array System (VERITAS). with a rise time of ∼2.3 hr and a decay time of ∼36 min. The peak flux above 200 GeV is (4.2 0.6) × 10−6 photon m−2 s−1 measured with a 4-minute-binned light curve, corresponding to ∼180% of the flux that is observed from the Crab Nebula above the same energy threshold. Variability contemporaneous with the TeV gamma-ray flare was observed in GeV gamma-ray, X-ray, and optical flux, as well as in optical and radio polarization. Additionally, a possible moving emission feature with superluminal apparent velocity was identified in Very Long Baseline Array observations at 43 GHz, potentially passing the radio core of the jet around the time of the gamma-ray flare. We discuss the constraints on the size, Lorentz factor, and location of the emitting region of the flare, and the interpretations with several theoretical models that invoke relativistic plasma passing stationary shocks.
Cosmic-ray electrons and positrons (CREs) at GeV-TeV energies are a unique probe of our local Galactic neighborhood. CREs lose energy rapidly via synchrotron radiation and inverse-Compton scattering ...processes while propagating within the Galaxy, and these losses limit their propagation distance. For electrons with TeV energies, the limit is on the order of a kiloparsec. Within that distance, there are only a few known astrophysical objects capable of accelerating electrons to such high energies. It is also possible that the CREs are the products of the annihilation or decay of heavy dark matter (DM) particles. VERITAS, an array of imaging air Cherenkov telescopes in southern Arizona, is primarily utilized for gamma-ray astronomy but also simultaneously collects CREs during all observations. We describe our methods of identifying CREs in VERITAS data and present an energy spectrum, extending from 300 GeV to 5 TeV, obtained from approximately 300 hours of observations. A single power-law fit is ruled out in VERITAS data. We find that the spectrum of CREs is consistent with a broken power law, with a break energy at 710±40stat±140syst GeV.
Diagnosis of deep vein thrombosis (DVT) and pulmonary embolism (PE) is an important medical problem because of the high fatality rate from PE and the large number of cases not diagnosed before ...causing death. Over the last decade, there has been considerable research into the diagnostic process. It is widely accepted that venous ultrasound imaging is an accurate test for the diagnosis of DVT and is the imaging test of choice. For PE, computer tomographic pulmonary angiography (CTPA) is replacing ventilation perfusion lung scanning. Technology for CTPA is rapidly evolving and multi-row detector scans have quite reasonable sensitivity and specificity. Despite the accuracy of imaging tests, the post-test probability of disease is highly dependent on pretest probability. Clinical evaluation tools have developed that enable us to accurately categorize patients' risk prior to diagnostic imaging. One advantage of this characterization is an ability to exclude the diagnosis of DVT or PE if clinical probability is sufficiently low and when the D-dimer is negative. There are now a number of D-dimer assays that have well-defined specificities and sensitivities, which enable use in conjunction with clinical probability. A careful combination of clinical assessment, D-dimer and imaging enables safe PE rule out protocols without imaging, an ability to suspect false positive imaging results, and more accurate determination of true positive imaging. These integration strategies result in safer, more convenient and cost-effective care for patients.
Objective To summarise and compare the efficacy and safety of various oral anticoagulants (dabigatran, rivaroxaban, apixaban, and vitamin K antagonists) and antiplatelet agents (acetylsalicylic acid) ...for the secondary prevention of venous thromboembolism. Design Systematic review and network meta-analysis. Data sources Literature search using Medline (1950 to present), Embase (1980 to present), and the Cochrane Register of Controlled Trials using the OVID interface. Publications from potentially relevant journals were also searched by hand. Review methods Randomised controlled trials of patients receiving anticoagulants, antiplatelet drugs, or placebo or observation for secondary prevention of venous thromboembolism. Selected outcomes were rates of recurrent venous thromboembolism and major bleeding. Two reviewers independently extracted data onto standardised forms. Results 12 articles met our inclusion criteria, with 11 999 patients evaluated for efficacy and 12 167 for safety. All treatments reduced the risk of recurrent venous thromboembolism. Compared with placebo or observation, vitamin K antagonists at a standard adjusted dose (target international normalised ratio 2.0-3.0) showed the highest risk difference (odds ratio 0.07; 95% credible interval 0.03 to 0.15) and acetylsalicylic acid showed the lowest risk difference (0.65; 0.39 to 1.03). Risk of major bleeding was higher with a standard adjusted dose of vitamin K antagonists (5.24; 1.78 to 18.25) than with placebo or observation. Fatal recurrent venous thromboembolism and fatal bleeding were rare. Detailed subgroup and individual patient level data were not available. Conclusions All oral anticoagulants and antiplatelet agents investigated in this analysis were associated with a reduced recurrence of venous thromboembolism compared with placebo or observation, although acetylsalicylic acid was associated with the lowest risk reduction. Vitamin K antagonists given at a standard adjusted dose was associated with the greatest risk reduction in recurrent venous thromboembolism, but also the greatest risk of major bleeding.
When warfarin is interrupted for surgery, low-molecular-weight heparin is often used as bridging therapy. However, this practice has never been evaluated in a large prospective study. This study was ...designed to assess the efficacy and safety of bridging therapy with low-molecular-weight heparin initiated out of hospital.
This was a prospective, multicenter, single-arm cohort study of patients at high risk of arterial embolism (prosthetic valves and atrial fibrillation with a major risk factor). Warfarin was held for 5 days preoperatively. Low-molecular-weight heparin was given 3 days preoperatively and at least 4 days postoperatively. Patients were followed up for 3 months for thromboembolism and bleeding. Eleven Canadian tertiary care academic centers participated; 224 patients were enrolled. Eight patients (3.6%; 95% CI, 1.8 to 6.9) had an episode of thromboembolism, of which 2 (0.9%; 95% CI, 0.2 to 3.2) were judged to be due to cardioembolism. Of these 8 episodes of thromboembolism, 6 occurred in patients who had warfarin deferred or withdrawn because of bleeding. There were 15 episodes of major bleeding (6.7%; 95% CI, 4.1 to 10.8): 8 occurred intraoperatively or early postoperatively before low-molecular-weight heparin was restarted, 5 occurred in the first postoperative week after low-molecular-weight heparin was restarted, and 2 occurred well after low-molecular-weight heparin was stopped. There were no deaths.
Bridging therapy with subcutaneous low-molecular-weight heparin is feasible; however, the optimal approach for the management of patients who require temporary interruption of warfarin to have invasive procedures is uncertain.
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