Hydrophobic polyamide nanofilms provide rapid transport for crude oil separation.

Hydrocarbon separation relies on energy-intensive distillation. Membrane technology can offer an energy-efficient alternative but requires selective differentiation of crude oil molecules with rapid liquid transport. We synthesized multiblock oligomer amines, which comprised a central amine segment with two hydrophobic oligomer blocks, and used them to fabricate hydrophobic polyamide nanofilms by interfacial polymerization from self-assembled vesicles. These polyamide nanofilms provide transport of hydrophobic liquids more than 100 times faster than that of conventional hydrophilic counterparts. In the fractionation of light crude oil, manipulation of the film thickness down to ~10 nanometers achieves permeance one order of magnitude higher than that of current state-of-the-art hydrophobic membranes while retaining comparable size- and class-based separation. This high permeance can markedly reduce plant footprint, which expands the potential for using membranes made of ultrathin nanofilms in crude oil fractionation

Solution-processable polytriazoles from spirocyclic monomers for membrane-based hydrocarbon separations

The thermal distillation of crude oil mixtures is an energy-intensive process, accounting for nearly 1% of global energy consumption. Membrane-based separations are an appealing alternative or tandem process to distillation due to intrinsic energy efficiency advantages. We developed a family of spirocyclic polytriazoles from structurally diverse monomers for membrane applications. The resulting polymers were prepared by a convenient step-growth method using copper-catalysed azide-alkyne cycloaddition, providing very fast reaction rates, high molecular weights and solubilities in common organic solvents and non-interconnected microporosity. Fractionation of whole Arabian light crude oil and atmospheric tower bottom feeds using these materials enriched the low-boiling-point components and removed trace heteroatom and metal impurities (comparable performance with the lighter feed as the commercial polyimide, Matrimid), demonstrating opportunities to reduce the energy cost of crude oil distillation with tandem membrane processes. Membrane-based molecular separation under these demanding conditions is made possible by high thermal stability and a moderate level of dynamic chain mobility, leading to transient interconnections between micropores, as revealed by the calculations of static and swollen pore structures

Direct-acting antiviral therapy significantly reduces early HCC recurrence: A multicenter u.s. cohort study.

Background: Direct-acting antiviral (DAA) therapy for hepatitis C (HCV) has a controversial impact on hepatocellular carcinoma (HCC) recurrence and tumor aggressiveness. We compared HCC recurrence patterns among DAA-treated and untreated patients who achieved HCC complete response (CR). Methods: We conducted a North American multicenter retrospective cohort study of patients with HCV-related HCC who achieved CR after resection, ablation, transarterial chemo/radioembolization or radiation therapy from 1/2013 to 12/2016. Patients who received DAA prior to CR or achieved CR via transplant or systemic therapy were excluded. Cox regression was used to examine the association between DAA therapy and time-to-recurrence from CR, with DAA therapy analyzed as a time-varying exposure. Patients were censored at death, transplant or last follow-up. Results: Of 866 HCV-HCC patients from 31 health systems, 355 (41.0%) received DAA therapy and 511 (59.0%) were untreated. DAAtreated patients were older (62.5 vs 61.4, p=0.03), more likely had BCLC 0/A HCC (87.3% vs 77.3%, p=0.001), and more likely received resection or ablation (58.0% vs 42.5%, p\u3c0.001) versus untreated patients, but a similar proportion presented within Milan Criteria (84.5% vs. 83.2%, p=0.60). Median time from HCC treatment to CR was 1.6 months, and 4.9 months from CR to DAA initiation. HCC recurred in 149 (42.0%) DAA-treated and 300 (58.7%) untreated patients-with 49 (32.9%) and 191 (63.6%) considered early recurrence (within 365 days of CR), respectively. Recurrence presented as a new intrahepatic lesion in 86 (58.1%) and 169 (57.1%) patients in each group, respectively. DAA therapy was associated with significantly reduced HCC recurrence risk (HR 0.41, 95%CI 0.32-0.52), adjusting for study site, age, sex, Child Pugh class, AFP level, initial tumor burden and HCC therapy leading to complete response. Results were similar when considering early recurrence only (HR 0.42 95%CI 0.30-0.60). In both groups, most recurrences were within Milan Criteria (91.0% vs 90.6%, p=0.84). A larger proportion of DAA-treated than untreated patients received potentially curative therapy (transplant, resection or ablation) for HCC recurrence (34.2% vs 25.7%, p=0.06). A similar proportion in both groups achieved CR or partial response to treatment of recurrence (49.6% vs 51.0%, p=0.80). Conclusion: In the largest cohort study to date, DAA therapy was associated with significantly reduced HCC recurrence, including early recurrence, after CR. HCC recurrence patterns, including tumor burden and treatment response, were similar in DAAtreated and untreated patients

Open Data from the Third Observing Run of LIGO, Virgo, KAGRA, and GEO

Abstract The global network of gravitational-wave observatories now includes five detectors, namely LIGO Hanford, LIGO Livingston, Virgo, KAGRA, and GEO 600. These detectors collected data during their third observing run, O3, composed of three phases: O3a starting in 2019 April and lasting six months, O3b starting in 2019 November and lasting five months, and O3GK starting in 2020 April and lasting two weeks. In this paper we describe these data and various other science products that can be freely accessed through the Gravitational Wave Open Science Center at https://gwosc.org. The main data set, consisting of the gravitational-wave strain time series that contains the astrophysical signals, is released together with supporting data useful for their analysis and documentation, tutorials, as well as analysis software packages.</jats:p

Search for Eccentric Black Hole Coalescences during the Third Observing Run of LIGO and Virgo

Abstract Despite the growing number of binary black hole coalescences confidently observed through gravitational waves so far, the astrophysical origin of these binaries remains uncertain. Orbital eccentricity is one of the clearest tracers of binary formation channels. Identifying binary eccentricity, however, remains challenging due to the limited availability of gravitational waveforms that include the effects of eccentricity. Here, we present observational results for a waveform-independent search sensitive to eccentric black hole coalescences, covering the third observing run (O3) of the LIGO and Virgo detectors. We identified no new high-significance candidates beyond those that have already been identified with searches focusing on quasi-circular binaries. We determine the sensitivity of our search to high-mass (total source-frame mass M &gt; 70 M ⊙) binaries covering eccentricities up to 0.3 at 15 Hz emitted gravitational-wave frequency, and use this to compare model predictions to search results. Assuming all detections are indeed quasi-circular, for our fiducial population model, we place a conservative upper limit for the merger rate density of high-mass binaries with eccentricities 0 &lt; e ≤ 0.3 at 16.9 Gpc−3 yr−1 at the 90% confidence level.</jats:p

Search for Eccentric Black Hole Coalescences during the Third Observing Run of LIGO and Virgo

Abstract Despite the growing number of binary black hole coalescences confidently observed through gravitational waves so far, the astrophysical origin of these binaries remains uncertain. Orbital eccentricity is one of the clearest tracers of binary formation channels. Identifying binary eccentricity, however, remains challenging due to the limited availability of gravitational waveforms that include the effects of eccentricity. Here, we present observational results for a waveform-independent search sensitive to eccentric black hole coalescences, covering the third observing run (O3) of the LIGO and Virgo detectors. We identified no new high-significance candidates beyond those that have already been identified with searches focusing on quasi-circular binaries. We determine the sensitivity of our search to high-mass (total source-frame mass M &gt; 70 M ⊙) binaries covering eccentricities up to 0.3 at 15 Hz emitted gravitational-wave frequency, and use this to compare model predictions to search results. Assuming all detections are indeed quasi-circular, for our fiducial population model, we place a conservative upper limit for the merger rate density of high-mass binaries with eccentricities 0 &lt; e ≤ 0.3 at 16.9 Gpc−3 yr−1 at the 90% confidence level.</jats:p

Search for Gravitational-lensing Signatures in the Full Third Observing Run of the LIGO–Virgo Network

Abstract Gravitational lensing by massive objects along the line of sight to the source causes distortions to gravitational wave (GW) signals; such distortions may reveal information about fundamental physics, cosmology, and astrophysics. In this work, we have extended the search for lensing signatures to all binary black hole events from the third observing run of the LIGO-Virgo network. We search for repeated signals from strong lensing by (1) performing targeted searches for subthreshold signals, (2) calculating the degree of overlap among the intrinsic parameters and sky location of pairs of signals, (3) comparing the similarities of the spectrograms among pairs of signals, and (4) performing dual-signal Bayesian analysis that takes into account selection effects and astrophysical knowledge. We also search for distortions to the gravitational waveform caused by (1) frequency-independent phase shifts in strongly lensed images, and (2) frequency-dependent modulation of the amplitude and phase due to point masses. None of these searches yields significant evidence for lensing. Finally, we use the nondetection of GW lensing to constrain the lensing rate based on the latest merger-rate estimates and the fraction of dark matter composed of compact objects.</jats:p

Search for Gravitational-lensing Signatures in the Full Third Observing Run of the LIGO–Virgo Network

Abstract Gravitational lensing by massive objects along the line of sight to the source causes distortions to gravitational wave (GW) signals; such distortions may reveal information about fundamental physics, cosmology, and astrophysics. In this work, we have extended the search for lensing signatures to all binary black hole events from the third observing run of the LIGO-Virgo network. We search for repeated signals from strong lensing by (1) performing targeted searches for subthreshold signals, (2) calculating the degree of overlap among the intrinsic parameters and sky location of pairs of signals, (3) comparing the similarities of the spectrograms among pairs of signals, and (4) performing dual-signal Bayesian analysis that takes into account selection effects and astrophysical knowledge. We also search for distortions to the gravitational waveform caused by (1) frequency-independent phase shifts in strongly lensed images, and (2) frequency-dependent modulation of the amplitude and phase due to point masses. None of these searches yields significant evidence for lensing. Finally, we use the nondetection of GW lensing to constrain the lensing rate based on the latest merger-rate estimates and the fraction of dark matter composed of compact objects.</jats:p

Model-based Cross-correlation Search for Gravitational Waves from the Low-mass X-Ray Binary Scorpius X-1 in LIGO O3 Data

We present the results of a model-based search for continuous gravitational waves from the low-mass X-ray binary Scorpius X-1 using LIGO detector data from the third observing run of Advanced LIGO and Advanced Virgo. This is a semicoherent search that uses details of the signal model to coherently combine data separated by less than a specified coherence time, which can be adjusted to balance sensitivity with computing cost. The search covered a range of gravitational-wave frequencies from 25 to 1600 Hz, as well as ranges in orbital speed, frequency, and phase determined from observational constraints. No significant detection candidates were found, and upper limits were set as a function of frequency. The most stringent limits, between 100 and 200 Hz, correspond to an amplitude h0 of about 10−25 when marginalized isotropically over the unknown inclination angle of the neutron star's rotation axis, or less than 4 × 10−26 assuming the optimal orientation. The sensitivity of this search is now probing amplitudes predicted by models of torque balance equilibrium. For the usual conservative model assuming accretion at the surface of the neutron star, our isotropically marginalized upper limits are close to the predicted amplitude from about 70 to 100 Hz; the limits assuming that the neutron star spin is aligned with the most likely orbital angular momentum are below the conservative torque balance predictions from 40 to 200 Hz. Assuming a broader range of accretion models, our direct limits on gravitational-wave amplitude delve into the relevant parameter space over a wide range of frequencies, to 500 Hz or more