Miracle-dz/UniFAR-FTUs huggingface dataset:
Metastable ferroelectricity in optically strained SrTiO3

Driving strontium titanate ferroelectric Hidden phases are metastable collective states of matter that are typically not accessible on equilibrium phase diagrams. Nova et al. used infrared pulses to excite higher-frequency lattice modes that drive the crystal into a metastable ferroelectric phase, a phase that can persist for many hours. X. Li et al. used terahertz fields to drive the soft mode that moves the ions in the crystal into the positions they occupy in the new phase. The ferroelectric phase in this case was transient, lasting on the order of 10 picoseconds. Because these hidden phases can host exotic properties in otherwise conventional materials, the accessibility to and control of such hidden phases may broaden potential functionality and applications. Science, this issue p. 1075, p. 1079 The paraelectric strontium titanate can be optically driven into a ferroelectric hidden phase. Fluctuating orders in solids are generally considered high-temperature precursors of broken symmetry phases. However, in some cases, these fluctuations persist to zero temperature and prevent the emergence of long-range order. Strontium titanate (SrTiO3) is a quantum paraelectric in which dipolar fluctuations grow upon cooling, although a long-range ferroelectric order never sets in. Here, we show that optical excitation of lattice vibrations can induce polar order. This metastable polar phase, observed up to temperatures exceeding 290 kelvin, persists for hours after the optical pump is interrupted. Furthermore, hardening of a low-frequency vibration points to a photoinduced ferroelectric phase transition, with a spatial domain distribution suggestive of a photoflexoelectric coupling.
Doppler Shift Oscillations from a Hot Line Observed by IRIS

We present a detailed investigation of the Doppler shift oscillations in a hot loop during an M7.1 flare on 2014 October 27 observed by the Interface Region Imaging Spectrograph. The periodic oscillations are observed in the Doppler shift of Fe xxi 1354.09 Å (log T ∼ 7.05 ), and the dominant period is about 3.1 minutes. However, such 3.1 minute oscillations are not found in the line-integrated intensity of Fe xxi 1354.09 Å, AIA EUV fluxes, or microwave emissions. Solar Dynamics Observatory/AIA and Hinode/XRT imaging observations indicate that the Doppler shift oscillations locate at the hot loop-top region (≥11 MK). Moreover, the differential emission measure results show that the temperature is increasing rapidly when the Doppler shift oscillates, but the number density does not exhibit the corresponding increases nor oscillations, implying that the flare loop is likely to oscillate in an incompressible mode. All of these facts suggest that the Doppler shift oscillations at the shorter period are most likely the standing kink oscillations in a flare loop. Meanwhile, a longer period of about 10 minutes is identified in the time series of Doppler shift and line-integrated intensity, GOES SXR fluxes, and AIA EUV light curves, indicating the periodic energy release in this flare, which may be caused by a slow mode wave.
A SELF-CONSISTENT MODEL OF THE CIRCUMSTELLAR DEBRIS CREATED BY A GIANT HYPERVELOCITY IMPACT IN THE HD 172555 SYSTEM

Spectral modeling of the large infrared excess in the Spitzer IRS spectra of HD 172555 suggests that there is more than 1019 kg of submicron dust in the system. Using physical arguments and constraints from observations, we rule out the possibility of the infrared excess being created by a magma ocean planet or a circumplanetary disk or torus. We show that the infrared excess is consistent with a circumstellar debris disk or torus, located at ∼6 AU, that was created by a planetary scale hypervelocity impact. We find that radiation pressure should remove submicron dust from the debris disk in less than one year. However, the system's mid-infrared photometric flux, dominated by submicron grains, has been stable within 4% over the last 27 years, from the Infrared Astronomical Satellite (1983) to WISE (2010). Our new spectral modeling work and calculations of the radiation pressure on fine dust in HD 172555 provide a self-consistent explanation for this apparent contradiction. We also explore the unconfirmed claim that ∼1047 molecules of SiO vapor are needed to explain an emission feature at ∼8 μm in the Spitzer IRS spectrum of HD 172555. We find that unless there are ∼1048 atoms or 0.05 M⊕ of atomic Si and O vapor in the system, SiO vapor should be destroyed by photo-dissociation in less than 0.2 years. We argue that a second plausible explanation for the ∼8 μm feature can be emission from solid SiO, which naturally occurs in submicron silicate “smokes” created by quickly condensing vaporized silicate.
Serum Fibroblast Growth Factor 19 as a Biomarker in Hepatitis B Virus-Related Liver Disease

Background: Past research has found that fibroblast growth factor 19 (FGF19) is associated with several hepatic disorders, such as alcoholic liver disease and primary biliary cirrhosis. However, there is currently a lack of relevant studies on the relationship between FGF19 and hepatitis B virus (HBV)-related liver disease. Objectives: This study aimed to assess the role of serum FGF19 as a new biomarker for HBV-related liver disease and provide scientific data to show the clinical value of this biomarker. Methods: A retrospective study included 37 patients with chronic hepatitis B (CHB), 33 patients with HBV-related cirrhosis (HBV-cirrhosis), and 32 patients with HBV-related hepatocellular carcinoma (HBV-HCC). Furthermore, 33 normal people were randomly selected as healthy controls. The serum levels of FGF19 were measured by ELISA. Results: Serum FGF19 levels were increased sequentially in the CHB group, HBV-cirrhosis group, and HBV-HCC group. Furthermore, serum FGF19 levels positively correlated with alpha-fetoprotein, prothrombin time, international normalized ratio, total bilirubin, direct bilirubin, alanine aminotransferase, aspartate aminotransferase, gamma-glutamyl-transferase, alkaline phosphatase, total bile acid, serum markers for liver fibrosis, ascites, cirrhosis, Child-Pugh classification and model for end-stage liver disease sodium (MELD-Na) score, while negatively correlated with platelet count, prothrombin activity, and albumin. The diagnostic threshold of serum FGF19 for HBV-related HCC was 165.32 pg/mL, with a sensitivity of 81.25% and specificity of 58.57%. Conclusions: Serum FGF19 levels are positively associated with cholestasis, hepatocyte damage, and liver fibrosis but negatively correlated with liver synthetic function and liver functional reserve in HBV-related liver disease. Diverse changes in serum FGF19 may be used as a predictive marker for the progression of HBV-related liver disease. In addition, serum FGF19 has a potential role in monitoring carcinogenesis in patients with HBV-related liver disease.
Search for Supersymmetry Using Final States with One Lepton, Jets, and Missing Transverse Momentum with the ATLAS Detector in √s=TeV pp Collisions

This Letter presents the first search for supersymmetry in final states containing one isolated electron or muon, jets, and missing transverse momentum from root s = 7 TeV proton-proton collisions at the LHC. The data were recorded by the ATLAS experiment during 2010 and correspond to a total integrated luminosity of 35 pb(-1). No excess above the standard model background expectation is observed. Limits are set on the parameters of the minimal supergravity framework, extending previous limits. Within this framework, for A(0) = 0 GeV, tan beta = 3, and mu > 0 and for equal squark and gluino masses, gluino masses below 700 GeV are excluded at 95% confidence level.
Determining the fraction of reddened quasars in COSMOS with multiple selection techniques from X-ray to radio wavelengths

The sub-population of quasars reddened by intrinsic or intervening clouds of dust are known to be underrepresented in optical quasar surveys. By defining a complete parent sample of the brightest and spatially unresolved quasars in the COSMOS field, we quantify to which extent this sub-population is fundamental to our understanding of the true population of quasars. By using the available multiwavelength data of various surveys in the COSMOS field, we built a parent sample of 33 quasars brighter than $J=20$ mag, identified by reliable X-ray to radio wavelength selection techniques. Spectroscopic follow-up with the NOT/ALFOSC was carried out for four candidate quasars that had not been targeted previously to obtain a 100\% redshift completeness of the sample. The population of high $A_V$ quasars (HAQs), a specific sub-population of quasars selected from optical/near-infrared photometry, is found to contribute $21\%^{+9}_{-5}$ of the parent sample. The full population of bright spatially unresolved quasars represented by our parent sample consists of $39\%^{+9}_{-8}$ reddened quasars defined by having $A_V>0.1$, and $21\%^{+9}_{-5}$ of the sample having $E(B-V)>0.1$ assuming the extinction curve of the Small Magellanic Cloud. We show that the HAQ selection works well for selecting reddened quasars, but some are missed because their optical spectra are too blue to pass the $g-r$ color cut in the HAQ selection. This is either due to a low degree of dust reddening or anomalous spectra. We find that the fraction of quasars with contributing light from the host galaxy is most dominant at $z \lesssim 1$. At higher redshifts the population of spatially unresolved quasars selected by our parent sample is found to be representative of the full population at $J<20$ mag. This work quantifies the bias against reddened quasars in studies that are based solely on optical surveys.
UPDATED MASS SCALING RELATIONS FOR NUCLEAR STAR CLUSTERS AND A COMPARISON TO SUPERMASSIVE BLACK HOLES

We investigate whether or not nuclear star clusters and supermassive black holes (SMBHs) follow a common set of mass scaling relations with their host galaxy's properties, and hence can be considered to form a single class of central massive object (CMO). We have compiled a large sample of galaxies with measured nuclear star cluster masses and host galaxy properties from the literature and fit log-linear scaling relations. We find that nuclear star cluster mass, MNC, correlates most tightly with the host galaxy's velocity dispersion: log MNC = (2.11 ± 0.31)log (σ/54) + (6.63 ± 0.09), but has a slope dramatically shallower than the relation defined by SMBHs. We find that the nuclear star cluster mass relations involving host galaxy (and spheroid) luminosity and stellar and dynamical mass, intercept with but are in general shallower than the corresponding black hole scaling relations. In particular, MNC∝M0.55 ± 0.15Gal, dyn; the nuclear cluster mass is not a constant fraction of its host galaxy or spheroid mass. We conclude that nuclear stellar clusters and SMBHs do not form a single family of CMOs.
Cavity Casimir-Polder Forces and Their Effects in Ground-State Chemical Reactivity

Here we present a fundamental study on how the ground-state chemical reactivity of a molecule can be modified in a QED scenario, i.e., when it is placed inside a cavity and there is strong coupling between the cavity field and vibrational modes within the molecule. We work with a model system for the molecule (Shin-Metiu model) in which nuclear, electronic and photonic degrees of freedom are treated on the same footing. This simplified model allows the comparison of exact quantum reaction rate calculations with predictions emerging from transition state theory based on the cavity Born-Oppenheimer approach. We demonstrate that QED effects are indeed able to significantly modify activation barriers in chemical reactions and, as a consequence, reaction rates. The critical physical parameter controlling this effect is the permanent dipole of the molecule and how this magnitude changes along the reaction coordinate. We show that the effective coupling can lead to significant single-molecule energy shifts in an experimentally available nanoparticle-on-mirror cavity. We then apply the validated theory to a realistic case (internal rotation in the 1,2-dichloroethane molecule), showing how reactions can be inhibited or catalyzed depending on the profile of the molecular dipole. Furthermore, we discuss the absence of resonance effects in this process, which can be understood through its connection to Casimir-Polder forces. Finally, we treat the case of many-molecule strong coupling, and find collective modifications of reaction rates if the molecular permanent dipole moments are oriented with respected to the cavity field. This demonstrates that collective coupling can also provide a mechanism for modifying ground-state chemical reactivity of an ensemble of molecules coupled to a cavity mode.
Pore-Level Multiphase Simulations of Realistic Distillation Membranes for Water Desalination

Membrane distillation (MD) is a thermally driven separation process that is operated below boiling point. Since the performance of MD modules is still comparatively low, current research aims to improve the understanding of the membrane structure and its underlying mechanisms at the pore level. Based on existing realistic 3D membrane geometries (up to 0.5 billion voxels with 39nm resolution) obtained from ptychographic X-ray computed tomography, the D3Q27 lattice Boltzmann (LB) method was used to investigate the interaction of the liquid and gaseous phase with the porous membrane material. In particular, the Shan and Chen multi-phase model was used to simulate multi-phase flow at the pore level. We investigated the liquid entry pressure of different membrane samples and analysed the influence of different micropillar structures on the Wenzel and Cassie–Baxter state of water droplets on rough hydrophobic surfaces. Moreover, we calculated the liquid entry pressure required for entering the membrane pores and extracted realistic water contact surfaces for different membrane samples. The influence of the micropillars and flow on the water-membrane contact surface was investigated. Finally, we determined the air–water interface within a partially saturated membrane, finding that the droplet size and distribution correlated with the porosity of the membrane.
Does Venture Capital Reputation Contribute to Pre-IPO Performance of Entrepreneurial Firms in the Chinese Context?

This study investigates venture capital (VC) reputation impact on the pre-IPO performance of the entrepreneurial firms backed by three kinds of VCs. This study employs backward stepwise regression models following prior theoretical frameworks to examine the research question. Based on a database of the top 50 VC firms ranked during 2016 to 2020 and their portfolio firms. This study shows some contingent contribution to pre-IPO firm performance. Firstly, the reputation of the Chinese government-owned VCs is negatively associated with their portfolio firm performance. Still, there is a positive relationship between foreign and local private VCs. Secondly, entrepreneurial firm performance is significantly associated with industry policy and entrepreneur’s performance than VC reputation. This study has practical implications for entrepreneurs and limited partners regarding their corporation relationships with the Chinese VCs. JEL codes: G24, G34
THE SPACE MOTION OF LEO I: THE MASS OF THE MILKY WAY'S DARK MATTER HALO

We combine our Hubble Space Telescope measurement of the proper motion of the Leo I dwarf spheroidal galaxy (presented in a companion paper) with the highest resolution numerical simulations of Galaxy-size dark matter halos in existence to constrain the mass of the Milky Way's dark matter halo (Mvir, MW). Despite Leo I's large Galactocentric space velocity (200 km s−1) and distance (261 kpc), we show that it is extremely unlikely to be unbound if Galactic satellites are associated with dark matter substructure, as 99.9% of subhalos in the simulations are bound to their host. The observed position and velocity of Leo I strongly disfavor a low-mass Milky Way: if we assume that Leo I is the least bound of the Milky Way's classical satellites, then we find that Mvir, MW > 1012 M☉ at 95% confidence for a variety of Bayesian priors on Mvir, MW. In lower mass halos, it is vanishingly rare to find subhalos at 261 kpc moving as fast as Leo I. Should an additional classical satellite be found to be less bound than Leo I, this lower limit on Mvir, MW would increase by 30%. Imposing a mass-weighted ΛCDM prior, we find a median Milky Way virial mass of Mvir, MW = 1.6 × 1012 M☉, with a 90% confidence interval of [1.0–2.4] × 1012 M☉. We also confirm a strong correlation between subhalo infall time and orbital energy in the simulations and show that proper motions can aid significantly in interpreting the infall times and orbital histories of satellites.
Spin states of iron impurities in magnesium oxide under pressure: a possible intermediate state

Ferropericlase (Mg,Fe)O is a major lower mantle mineral, and studying its properties is a fundamental step toward understanding the Earth's interior. Here, we performed a first-principles investigation on the properties of iron as an isolated impurity in magnesium oxide, which is the condition of ferropericlase under which iron-iron interactions could be neglected. The calculations were carried using the all-electron full-potential linearized augmented plane wave method within the density functional theory in the generalized gradient approximation plus the on-site Hubbard correction. We present the electronic and magnetic properties, electric and magnetic hyperfine splitting of this impurity in high and low spin states for several charge states at zero pressure, which were then extended to high pressures. For the impurity in the neutral charge state, our results indicated that there is a metastable intermediate spin state (S=1), in addition to the high (S=2) and low (S=0) spin states. Those results were discussed in the context of an intermediate spin state, experimentally identified in ferrosilicate perovskite.
Oscillations and instabilities of fast and differentially rotating relativistic stars

We study nonaxisymmetric oscillations of rapidly and differentially rotating relativistic stars in the Cowling approximation. Our equilibrium models are sequences of relativistic polytropes, where the differential rotation is described by the relativistic j-constant law. We show that a small degree of differential rotation raises the critical rotation value for which the quadrupolar f-mode becomes prone to the Chandrasekhar-Friedman-Schutz (CFS) instability, while the critical value of T/|W| at the mass-shedding limit is raised even more. For stiffer equations of state these effects are even more pronounced. When increasing differential rotation further to a high degree, the neutral point of the CFS instability first reaches a local maximum and is lowered afterwards. For stars with a rather high compactness we find that for a large degree of differential rotation the absolute value of the critical T/|W| is below the corresponding value for rigid rotation. We conclude that the onset of the CFS instability is eased for a small degree of differential rotation and for a large degree at least in stars with a higher compactness. Moreover, we were able to extract the eigenfrequencies and the eigenfunctions of r-modes for differentially rotating stars and our simulations show a good qualitative agreement with previousmore » Newtonian results. « less
Efficacy and safety of adjuvant therapy with PD‑1/PD‑L1 inhibitors in cancer

Anti-programmed cell death protein-1 (PD-1)/programmed cell death 1 ligand 1 (PD-L1) antibodies have been widely used in cancers. The present study aimed to evaluate the efficacy and safety of PD-1/PD-L1 inhibitors in human cancers. Studies were searched from Cochrane Library, PubMed and Embase databases. Randomized controlled trials (RCTs) that investigated adjuvant therapy with anti-PD-1/PD-L1 agents in solid cancers were eligible for inclusion. As the primary focus of the meta-analysis, clinical outcome measures including overall survival (OS), disease-free survival (DFS), and adverse events (AEs) were analyzed by Stata 15.0 software. A total of six RCTs (n=4,436) met the inclusion criteria. The DFS [hazard ratio (HR)=0.71; 95% confidence interval (CI): 0.63-0.78; P<0.001] and OS (HR=0.66, 95% CI: 0.46-0.86, P<0.001) of patients were significantly prolonged by adjuvant immunotherapy. Subgroup analysis indicated that significantly improved DFS was observed in patients treated with different anti-PD-1/PD-L1 drugs (nivolumab, pembrolizumab, or atezolizumab), as well as in those with different tumors (melanoma, urothelial carcinoma, esophageal or gastroesophageal junction cancer, or renal cell carcinoma), and PD-L1 status [negative (<1%) or positive (≥1%)]. However, PD-1/PD-L1 inhibitors was associated with increased ≥ grade 3 treatment-related AEs (odds ratio=1.63; 95% CI: 1.20-2.21; P=0.002). The available evidence suggests that adjuvant therapy with PD-1/PD-L1 inhibitors provided more survival benefit than placebo for patients with cancer, with increased grade 3 or higher AEs. Prospero registration no. CRD42021290654.
New insights on Stephan’s Quintet: exploring the shock in three dimensions

Aims. We study the ionized gas emission from the large scale shock region of Stephan’s Quintet (SQ). Methods. We carried out integral field unit (IFU) optical spectroscopy on three pointings in and near the SQ shock. We used Potsdam MultiAperture Spectrometer (PMAS) on the 3.5 m Calar Alto telescope to obtain measures of emission lines that provide insight into physical properties of the gas. Severe blending of Hα and [Nii]λ6548, 6583 A emission lines in many spaxels required the assumption of at least two kinematical components to extract fluxes for the individual lines. Results. The main results from our study include (a) detection of discrete emission features in the new intruder velocity range 5400–6000 km s −1 showing properties consistent with Hii regions, (b) detection of a low-velocity component spanning the range 5800−6300 km s −1 with properties resembling a solar-metallicity shocked gas and (c) detection of a high-velocity component at ≈6600 km s −1 with properties consistent with those of a low-metallicity shocked gas. Conclusions. The two shocked components are interpreted as products of a collision between NGC 7318b new intruder and a debris field in its path. This has given rise to a complex structure of ionized gas where several components with different kinematical and physical properties coexist, although part of the original interstellar medium (ISM) associated with NGC 7318b is still present and remains unaltered. Our observations suggest that the low-velocity ionized component might have existed before the new intruder collision and could be associated with the NW-LV Hi component. The high-velocity ionized component might fill the gap between the Hi complexes observed in SQ-A and NGC 7319’s tidal filament (NW-HV, Arc-N and Arc-S in Williams et al. 2002, AJ, 123, 2417).