276 research outputs found

    Design and Evaluation of Tumor‐Specific Dendrimer Epigenetic Therapeutics

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    Histone deacetylase inhibitors (HDACi) are promising therapeutics for cancer. HDACi alter the epigenetic state of tumors and provide a unique approach to treat cancer. Although studies with HDACi have shown promise in some cancers, variable efficacy and off‐target effects have limited their use. To overcome some of the challenges of traditional HDACi, we sought to use a tumor‐specific dendrimer scaffold to deliver HDACi directly to cancer cells. Here we report the design and evaluation of tumor‐specific dendrimer–HDACi conjugates. The HDACi was conjugated to the dendrimer using an ester linkage through its hydroxamic acid group, inactivating the HDACi until it is released from the dendrimer. Using a cancer cell model, we demonstrate the functionality of the tumor‐specific dendrimer–HDACi conjugates. Furthermore, we demonstrate that unlike traditional HDACi, dendrimer–HDACi conjugates do not affect tumor‐associated macrophages, a recently recognized mechanism through which drug resistance emerges. We anticipate that this new class of cell‐specific epigenetic therapeutics will have tremendous potential in the treatment of cancer.Targeting tumors via epigenetics: Histone deacetylase inhibitors (HDACi) alter the epigenetic state of tumors and are promising therapeutics for cancer. Although studies with HDACi have shown promise in some cancers, variable efficacy and off‐target effects have limited their use. Here we report the design and evaluation of a tumor‐specific dendrimer–HDACi.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/111996/1/open201402141.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/111996/2/open201402141-sup-0001-misc_information.pd

    Genetic Variants For Head Size Share Genes and Pathways With Cancer

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    The size of the human head is highly heritable, but genetic drivers of its variation within the general population remain unmapped. We perform a genome-wide association study on head size (N = 80,890) and identify 67 genetic loci, of which 50 are novel. Neuroimaging studies show that 17 variants affect specific brain areas, but most have widespread effects. Gene set enrichment is observed for various cancers and the p53, Wnt, and ErbB signaling pathways. Genes harboring lead variants are enriched for macrocephaly syndrome genes (37-fold) and high-fidelity cancer genes (9-fold), which is not seen for human height variants. Head size variants are also near genes preferentially expressed in intermediate progenitor cells, neural cells linked to evolutionary brain expansion. Our results indicate that genes regulating early brain and cranial growth incline to neoplasia later in life, irrespective of height. This warrants investigation of clinical implications of the link between head size and cancer

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

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    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

    Open data from the third observing run of LIGO, Virgo, KAGRA and GEO

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    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 April of 2019 and lasting six months, O3b starting in November of 2019 and lasting five months, and O3GK starting in April of 2020 and lasting 2 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 dataset, 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.Comment: 27 pages, 3 figure

    All-sky search for long-duration gravitational-wave bursts in the third Advanced LIGO and Advanced Virgo run

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    After the detection of gravitational waves from compact binary coalescences, the search for transient gravitational-wave signals with less well-defined waveforms for which matched filtering is not well suited is one of the frontiers for gravitational-wave astronomy. Broadly classified into “short” â‰Č1  s and “long” ≳1  s duration signals, these signals are expected from a variety of astrophysical processes, including non-axisymmetric deformations in magnetars or eccentric binary black hole coalescences. In this work, we present a search for long-duration gravitational-wave transients from Advanced LIGO and Advanced Virgo’s third observing run from April 2019 to March 2020. For this search, we use minimal assumptions for the sky location, event time, waveform morphology, and duration of the source. The search covers the range of 2–500 s in duration and a frequency band of 24–2048 Hz. We find no significant triggers within this parameter space; we report sensitivity limits on the signal strength of gravitational waves characterized by the root-sum-square amplitude hrss as a function of waveform morphology. These hrss limits improve upon the results from the second observing run by an average factor of 1.8

    The population of merging compact binaries inferred using gravitational waves through GWTC-3

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    We report on the population properties of 76 compact binary mergers detected with gravitational waves below a false alarm rate of 1 per year through GWTC-3. The catalog contains three classes of binary mergers: BBH, BNS, and NSBH mergers. We infer the BNS merger rate to be between 10 Gpc−3yr−1\rm{Gpc^{-3} yr^{-1}} and 1700 Gpc−3yr−1\rm{Gpc^{-3} yr^{-1}} and the NSBH merger rate to be between 7.8 Gpc−3 yr−1\rm{Gpc^{-3}\, yr^{-1}} and 140 Gpc−3yr−1\rm{Gpc^{-3} yr^{-1}} , assuming a constant rate density versus comoving volume and taking the union of 90% credible intervals for methods used in this work. Accounting for the BBH merger rate to evolve with redshift, we find the BBH merger rate to be between 17.9 Gpc−3 yr−1\rm{Gpc^{-3}\, yr^{-1}} and 44 Gpc−3 yr−1\rm{Gpc^{-3}\, yr^{-1}} at a fiducial redshift (z=0.2). We obtain a broad neutron star mass distribution extending from 1.2−0.2+0.1M⊙1.2^{+0.1}_{-0.2} M_\odot to 2.0−0.3+0.3M⊙2.0^{+0.3}_{-0.3} M_\odot. We can confidently identify a rapid decrease in merger rate versus component mass between neutron star-like masses and black-hole-like masses, but there is no evidence that the merger rate increases again before 10 M⊙M_\odot. We also find the BBH mass distribution has localized over- and under-densities relative to a power law distribution. While we continue to find the mass distribution of a binary's more massive component strongly decreases as a function of primary mass, we observe no evidence of a strongly suppressed merger rate above ∌60M⊙\sim 60 M_\odot. The rate of BBH mergers is observed to increase with redshift at a rate proportional to (1+z)Îș(1+z)^{\kappa} with Îș=2.9−1.8+1.7\kappa = 2.9^{+1.7}_{-1.8} for zâ‰Č1z\lesssim 1. Observed black hole spins are small, with half of spin magnitudes below χi≃0.25\chi_i \simeq 0.25. We observe evidence of negative aligned spins in the population, and an increase in spin magnitude for systems with more unequal mass ratio

    A Joint Fermi-GBM and Swift-BAT Analysis of Gravitational-wave Candidates from the Third Gravitational-wave Observing Run

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    We present Fermi Gamma-ray Burst Monitor (Fermi-GBM) and Swift Burst Alert Telescope (Swift-BAT) searches for gamma-ray/X-ray counterparts to gravitational-wave (GW) candidate events identified during the third observing run of the Advanced LIGO and Advanced Virgo detectors. Using Fermi-GBM onboard triggers and subthreshold gamma-ray burst (GRB) candidates found in the Fermi-GBM ground analyses, the Targeted Search and the Untargeted Search, we investigate whether there are any coincident GRBs associated with the GWs. We also search the Swift-BAT rate data around the GW times to determine whether a GRB counterpart is present. No counterparts are found. Using both the Fermi-GBM Targeted Search and the Swift- BAT search, we calculate flux upper limits and present joint upper limits on the gamma-ray luminosity of each GW. Given these limits, we constrain theoretical models for the emission of gamma rays from binary black hole mergers

    Search for anisotropic gravitational-wave backgrounds using data from Advanced LIGO and Advanced Virgo's first three observing runs

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    We report results from searches for anisotropic stochastic gravitational-wave backgrounds using data from the first three observing runs of the Advanced LIGO and Advanced Virgo detectors. For the first time, we include Virgo data in our analysis and run our search with a new efficient pipeline called {\tt PyStoch} on data folded over one sidereal day. We use gravitational-wave radiometry (broadband and narrow band) to produce sky maps of stochastic gravitational-wave backgrounds and to search for gravitational waves from point sources. A spherical harmonic decomposition method is employed to look for gravitational-wave emission from spatially-extended sources. Neither technique found evidence of gravitational-wave signals. Hence we derive 95\% confidence-level upper limit sky maps on the gravitational-wave energy flux from broadband point sources, ranging from Fα,Θ<(0.013−7.6)×10−8erg cm−2 s−1 Hz−1,F_{\alpha, \Theta} < {\rm (0.013 - 7.6)} \times 10^{-8} {\rm erg \, cm^{-2} \, s^{-1} \, Hz^{-1}}, and on the (normalized) gravitational-wave energy density spectrum from extended sources, ranging from Ωα,Θ<(0.57−9.3)×10−9 sr−1\Omega_{\alpha, \Theta} < {\rm (0.57 - 9.3)} \times 10^{-9} \, {\rm sr^{-1}}, depending on direction (Θ\Theta) and spectral index (α\alpha). These limits improve upon previous limits by factors of 2.9−3.52.9 - 3.5. We also set 95\% confidence level upper limits on the frequency-dependent strain amplitudes of quasimonochromatic gravitational waves coming from three interesting targets, Scorpius X-1, SN 1987A and the Galactic Center, with best upper limits range from h0<(1.7−2.1)×10−25,h_0 < {\rm (1.7-2.1)} \times 10^{-25}, a factor of ≄2.0\geq 2.0 improvement compared to previous stochastic radiometer searches.Comment: 23 Pages, 9 Figure

    Population of Merging Compact Binaries Inferred Using Gravitational Waves through GWTC-3

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    We report on the population properties of compact binary mergers inferred from gravitational-wave observations of these systems during the first three LIGO-Virgo observing runs. The Gravitational-Wave Transient Catalog 3 (GWTC-3) contains signals consistent with three classes of binary mergers: binary black hole, binary neutron star, and neutron star-black hole mergers. We infer the binary neutron star merger rate to be between 10 and 1700 Gpc-3 yr-1 and the neutron star-black hole merger rate to be between 7.8 and 140 Gpc-3 yr-1, assuming a constant rate density in the comoving frame and taking the union of 90% credible intervals for methods used in this work. We infer the binary black hole merger rate, allowing for evolution with redshift, to be between 17.9 and 44 Gpc-3 yr-1 at a fiducial redshift (z=0.2). The rate of binary black hole mergers is observed to increase with redshift at a rate proportional to (1+z)Îș with Îș=2.9-1.8+1.7 for zâ‰Č1. Using both binary neutron star and neutron star-black hole binaries, we obtain a broad, relatively flat neutron star mass distribution extending from 1.2-0.2+0.1 to 2.0-0.3+0.3M⊙. We confidently determine that the merger rate as a function of mass sharply declines after the expected maximum neutron star mass, but cannot yet confirm or rule out the existence of a lower mass gap between neutron stars and black holes. We also find the binary black hole mass distribution has localized over- and underdensities relative to a power-law distribution, with peaks emerging at chirp masses of 8.3-0.5+0.3 and 27.9-1.8+1.9M⊙. While we continue to find that the mass distribution of a binary's more massive component strongly decreases as a function of primary mass, we observe no evidence of a strongly suppressed merger rate above approximately 60M⊙, which would indicate the presence of a upper mass gap. Observed black hole spins are small, with half of spin magnitudes below χi≈0.25. While the majority of spins are preferentially aligned with the orbital angular momentum, we infer evidence of antialigned spins among the binary population. We observe an increase in spin magnitude for systems with more unequal-mass ratio. We also observe evidence of misalignment of spins relative to the orbital angular momentum

    Constraints on dark photon dark matter using data from LIGO's and Virgo's third observing run

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    We present a search for dark photon dark matter that could couple to gravitational-wave interferometers using data from Advanced LIGO and Virgo's third observing run. To perform this analysis, we use two methods, one based on cross-correlation of the strain channels in the two nearly aligned LIGO detectors, and one that looks for excess power in the strain channels of the LIGO and Virgo detectors. The excess power method optimizes the Fourier Transform coherence time as a function of frequency, to account for the expected signal width due to Doppler modulations. We do not find any evidence of dark photon dark matter with a mass between mA∌10−14−10−11m_{\rm A} \sim 10^{-14}-10^{-11} eV/c2c^2, which corresponds to frequencies between 10-2000 Hz, and therefore provide upper limits on the square of the minimum coupling of dark photons to baryons, i.e. U(1)BU(1)_{\rm B} dark matter. For the cross-correlation method, the best median constraint on the squared coupling is ∌1.31×10−47\sim1.31\times10^{-47} at mA∌4.2×10−13m_{\rm A}\sim4.2\times10^{-13} eV/c2c^2; for the other analysis, the best constraint is ∌2.4×10−47\sim 2.4\times 10^{-47} at mA∌5.7×10−13m_{\rm A}\sim 5.7\times 10^{-13} eV/c2c^2. These limits improve upon those obtained in direct dark matter detection experiments by a factor of ∌100\sim100 for mA∌[2−4]×10−13m_{\rm A}\sim [2-4]\times 10^{-13} eV/c2c^2, and are, in absolute terms, the most stringent constraint so far in a large mass range mA∌m_A\sim 2×10−13−8×10−122\times 10^{-13}-8\times 10^{-12} eV/c2c^2.Comment: 20 pages, 7 figure
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