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Systematic electronic structure in the cuprate parent state from quantum many-body simulations
No full textThe quantitative description of correlated electron materials remains a modern computational challenge. We demonstrate a numerical strategy to simulate correlated materials at the fully ab initio level beyond the solution of effective low-energy models and apply it to gain a detailed microscopic understanding across a family of cuprate superconducting materials in their parent undoped states. We uncover microscopic trends in the electron correlations and reveal the link between the material composition and magnetic energy scales through a many-body picture of excitation processes involving the buffer layers. Our work illustrates a path toward a quantitative and reliable understanding of more complex states of correlated materials at the ab initio many-body level
GOALS-JWST: Hidden Star Formation and Extended PAH Emission in the Luminous Infrared Galaxy VV 114
No full textJames Webb Space Telescope (JWST) Mid-Infrared Instrument (MIRI) images of the luminous infrared (IR) galaxy VV 114 are presented. This redshift ∼0.020 merger has a western component (VV 114W) rich in optical star clusters and an eastern component (VV 114E) hosting a luminous mid-IR nucleus hidden at UV and optical wavelengths by dust lanes. With MIRI, the VV 114E nucleus resolves primarily into bright NE and SW cores separated by 630 pc. This nucleus comprises 45% of the 15 μm light of VV 114, with the NE and SW cores having IR luminosities, L_(IR)(8 − 1000 μm) ∼ 8 ± 0.8 × 10¹⁰ L_⊙ and ∼ 5 ± 0.5 × 10¹⁰ L_⊙, respectively, and IR densities, Σ_(IR) ≳ 2 ± 0.2 × 10¹³ L_⊙ kpc⁻² and ≳ 7 ± 0.7 × 10¹² L_⊙ kpc⁻², respectively—in the range of Σ_(IR) for the Orion star-forming core and the nuclei of Arp 220. The NE core, previously speculated to have an active galactic nucleus (AGN), has starburst-like mid-IR colors. In contrast, the VV 114E SW core has AGN-like colors. Approximately 40 star-forming knots with L_(IR) ∼ 0.02–5 × 10¹⁰ L_⊙ are identified, 28% of which have no optical counterpart. Finally, diffuse emission accounts for 40%–60% of the mid-IR emission. Mostly notably, filamentary polycyclic aromatic hydrocarbon (PAH) emission stochastically excited by UV and optical photons accounts for half of the 7.7 μm light of VV 114. This study illustrates the ability of JWST to detect obscured compact activity and distributed PAH emission in the most extreme starburst galaxies in the local universe
A classifier for spurious astrometric solutions in Gaia eDR3
No full textThe Gaia early Data Release 3 has delivered exquisite astrometric data for 1.47 billion sources, which is revolutionizing many fields in astronomy. For a small fraction of these sources, the astrometric solutions are poor, and the reported values and uncertainties may not apply. Before any analysis, it is important to recognize and excise these spurious results – this is commonly done by means of quality flags in the Gaia catalogue. Here, we devise a means of separating ‘good’ from ‘bad’ astrometric solutions that is an order of magnitude cleaner than any single flag: 99.3 per cent pure and 97.3 per cent complete, as validated on our test data. We devise an extensive sample of manifestly bad astrometric solutions, with parallax that is negative at ≥4.5σ; and a corresponding sample of presumably good solutions, including sources in healpix pixels on the sky that do not contain such negative parallaxes, and sources that fall on the main sequence in a colour–absolute magnitude diagram. We then train a neural network that uses 17 pertinent Gaia catalogue entries and information about nearby sources to discriminate between these two samples, captured in a single ‘astrometric fidelity’ parameter. A diverse set of verification tests shows that our approach works very cleanly, including for sources with positive parallaxes. The main limitations of our approach are in the very low signal-to-noise ratio and the crowded regime. Our astrometric fidelities for all of eDR3 can be queried via the Virtual Observatory, our code and data are public
A dense 0.1-solar-mass star in a 51-minute-orbital-period eclipsing binary
No full textOf more than a thousand known cataclysmic variables (CVs), where a white dwarf is accreting from a hydrogen-rich star, only a dozen have orbital periods below 75 minutes. One way to achieve these short periods requires the donor star to have undergone substantial nuclear evolution before interacting with the white dwarf, and it is expected that these objects will transition to helium accretion. These transitional CVs have been proposed as progenitors of helium CVs. However, no known transitional CV is expected to reach an orbital period short enough to account for most of the helium CV population, leaving the role of this evolutionary pathway unclear. Here we report observations of ZTF J1813+4251, a 51-minute-orbital-period, fully eclipsing binary system consisting of a star with a temperature comparable to that of the Sun but a density 100 times greater owing to its helium-rich composition, accreting onto a white dwarf. Phase-resolved spectra, multi-band light curves and the broadband spectral energy distribution allow us to obtain precise and robust constraints on the masses, radii and temperatures of both components. Evolutionary modelling shows that ZTF J1813+4251 is destined to become a helium CV binary, reaching an orbital period under 20 minutes, rendering ZTF J1813+4251 a previously missing link between helium CV binaries and hydrogen-rich CVs
Enantioselective Construction of Sila-bicyclo[3.2.1] Scaffolds Bearing Both Carbon- and Silicon-Stereocenters
No full textA carbon-to-silicon switch in bioactive heterocycles has become a popular strategy in drug discovery. With the prevalence of chiral bridged biycyclic skeletons in numerous pharmacophores and alkaloids, the investigation of sila-bridged bicyclic skeletons as a potent bioisostere is significant. However, because organosilicon compounds are not available in nature, expanding their diversity fully depends on the development of effective synthetic methods. An optically active bridged bicyclic silicon scaffold has been clearly unprecedented to date due to the lack of an efficient synthetic method. Our study herein represents a rapid and enantioselective assembly of sila-bicyclo[3.2.1]octanes bearing both C- and Si-stereocenters, which involves the combined Heck reaction and enantioselective desymmetrization of silacyclopentenes with aryl halides in an intramolecular fashion. The synthetic utilities of these products and the origin of asymmetric induction are further investigated by diverse stereospecific downstream transformations and DFT calculations. We believe our study is highly sought after because of the prevalence of carbon congeners in biologically active molecules
Unicorns and giraffes in the binary zoo: stripped giants with subgiant companions
No full textWe analyse two binary systems containing giant stars, V723 Mon (‘the Unicorn’) and 2M04123153+6738486 (‘the Giraffe’). Both giants orbit more massive but less luminous companions, previously proposed to be mass-gap black holes. Spectral disentangling reveals luminous companions with star-like spectra in both systems. Joint modelling of the spectra, light curves, and spectral energy distributions robustly constrains the masses, temperatures, and radii of both components: the primaries are luminous, cool giants T_(eff, giant) = 3800 and 4000 K, R_(giant) = 22.5 and 25 R⊙ with exceptionally low masses M_(giant) ≈0.4 M⊙ that likely fill their Roche lobes. The secondaries are only slightly warmer subgiants T_(eff, 2) = 5800 and 5150 K, R₂ = 8.3 and 9 R⊙ and thus are consistent with observed UV limits that would rule out main-sequence stars with similar masses (M₂ ≈2.8 and ≈1.8 M⊙. In the Unicorn, rapid rotation blurs the spectral lines of the subgiant, making it challenging to detect even at wavelengths where it dominates the total light. Both giants have surface abundances indicative of CNO processing and subsequent envelope stripping. The properties of both systems can be reproduced by binary evolution models in which a 1-2 M⊙ primary is stripped by a companion as it ascends the giant branch. The fact that the companions are also evolved implies either that the initial mass ratio was very near unity, or that the companions are temporarily inflated due to rapid accretion. The Unicorn and Giraffe offer a window into into a rarely observed phase of binary evolution preceding the formation of wide-orbit helium white dwarfs, and eventually, compact binaries containing two helium white dwarfs
Dynamo Simulations of Jupiter's Magnetic Field: The Role of Stable Stratification and a Dilute Core
No full textUnderstanding Jupiter's present-day interior structure and dynamics is key to constraining planetary accretion models. In particular, the extent of stable stratification (i.e., non-convective regions) in the planet strongly influences long-term cooling processes, and may record primordial heavy element gradients from early in a planet's formation. Because the Galileo entry probe measured a subsolar helium abundance, Jupiter interior models often invoke an outer stably stratified region due to helium rain. Additionally, Juno gravity data suggest a deeper, potentially stratified dilute core extending halfway through the planet. However, fits to Jupiter's gravitational data are non-unique, and outstanding uncertainty over the equations of state for hydrogen and helium remain. Here, we use high-resolution numerical magnetohydrodynamic simulations of Jupiter's magnetic field to place constraints on the extent of stable stratification within the planet. We find that compared to traditional interior models, an upper stably stratified layer between 0.9 and 0.95 Jupiter radii (R_J) helps to explain both Jupiter's dipolar magnetic field and zonal winds. In contrast, an extended dilute core that is entirely stably stratified (no convective layers) yields significantly worse fits to both. However, our models with extended deep stratification still generate dipolar magnetic fields if an upper stratified region is also present. Overall, we find that a planet with a dilute core i.e., strongly stably stratified is increasingly challenging to reconcile with Jupiter's magnetic field and winds. Thus if a dilute core is present, alternative modalities such as a fully convective dilute core, a complex multilayered interior structure, or double diffusive convection may be required
Glasswing-Butterfly-Inspired Multifunctional Scleral Lens and Smartphone Raman Spectrometer for Point-of-Care Tear Biomarker Analysis
No full textAugmenting contact lenses with sensing capabilities requires incorporating multiple functionalities within a diminutive device. Inspired by multifunctional biophotonic nanostructures of glasswing butterflies, a nanostructured scleral lens with enhanced optical, bactericidal, and sensing capabilities is reported. When used in conjunction with a smartphone-integrated Raman spectrometer, the feasibility of point-of-care applications is demonstrated. The bioinspired nanostructures made on parylene films are mounted on the anterior and posterior side of a scleral lens to create a nanostructured lens. Compared to unstructured parylene, nanostructured parylene minimizes glare by 4.3-fold at large viewing angles up to 80o. When mounted on a scleral lens, the nanostructures block 2.8-fold more ultraviolet (UVA) light while offering 1.1-fold improved transmission in the visible regime. Furthermore, the nanostructures exhibit potent bactericidal activity against Escherichia coli, killing 89% of tested bacteria within 4 h. The same nanostructures, when gold-coated, are used to perform rapid label-free multiplex detection of lysozyme and lactoferrin, the protein biomarkers of the chronic dry eye disease, in whole human tears using drop-coating deposition Raman spectroscopy. The detection of both proteins in whole human tear samples from different subjects using the nanostructured lens produced excellent correlation with commercial enzyme-based assays while simultaneously displaying a 1.5-fold lower standard deviation
Evidence for WW/WZ vector boson scattering in the decay channel ℓνqq produced in association with two jets in proton-proton collisions at √s = 13 TeV
No full textEvidence is reported for electroweak (EW) vector boson scattering in the decay channel ℓνqq of two weak vector bosons WV (V = W or Z), produced in association with two parton jets. The search uses a data set of proton-proton collisions at 13 TeV collected with the CMS detector during 2016–2018 with an integrated luminosity of 138 fb⁻¹. Events are selected requiring one lepton (electron or muon), moderate missing transverse momentum, two jets with a large pseudorapidity separation and a large dijet invariant mass, and a signature consistent with the hadronic decay of a W/Z boson. The cross section is computed in a fiducial phase space defined at parton level requiring all parton transverse momenta p_T > 10 GeV and at least one pair of outgoing partons with invariant mass m_(qq) > 100 GeV. The measured and expected EW WV production cross sections are 1.90⁺⁰·⁵³₋₀.₄₆ pb and 2.23⁺⁰·⁰⁸₋₀.₁₁(scale) ± 0.05(PDF) pb, respectively, where PDF is the parton distribution function. The observed EW signal strength is µ_(EW) = 0.85 ± 0.12(stat)⁺⁰·¹⁹₋₀.₁₇(syst), corresponding to a signal significance of 4.4 standard deviations with 5.1 expected, and it is measured keeping the quantum chromodynamics (QCD) associated diboson production fixed to the standard model prediction. This is the first evidence of vector boson scattering in the ℓνqq decay channel at LHC. The simultaneous measurement of the EW and QCD associated diboson production agrees with the standard model prediction
Surgical gestures as a method to quantify surgical performance and predict patient outcomes
No full textHow well a surgery is performed impacts a patient’s outcomes; however, objective quantification of performance remains an unsolved challenge. Deconstructing a procedure into discrete instrument-tissue “gestures” is a emerging way to understand surgery. To establish this paradigm in a procedure where performance is the most important factor for patient outcomes, we identify 34,323 individual gestures performed in 80 nerve-sparing robot-assisted radical prostatectomies from two international medical centers. Gestures are classified into nine distinct dissection gestures (e.g., hot cut) and four supporting gestures (e.g., retraction). Our primary outcome is to identify factors impacting a patient’s 1-year erectile function (EF) recovery after radical prostatectomy. We find that less use of hot cut and more use of peel/push are statistically associated with better chance of 1-year EF recovery. Our results also show interactions between surgeon experience and gesture types—similar gesture selection resulted in different EF recovery rates dependent on surgeon experience. To further validate this framework, two teams independently constructe distinct machine learning models using gesture sequences vs. traditional clinical features to predict 1-year EF. In both models, gesture sequences are able to better predict 1-year EF (Team 1: AUC 0.77, 95% CI 0.73–0.81; Team 2: AUC 0.68, 95% CI 0.66–0.70) than traditional clinical features (Team 1: AUC 0.69, 95% CI 0.65–0.73; Team 2: AUC 0.65, 95% CI 0.62–0.68). Our results suggest that gestures provide a granular method to objectively indicate surgical performance and outcomes. Application of this methodology to other surgeries may lead to discoveries on methods to improve surgery