Gravitational waves enable tests of general relativity in the highly dynamical and strong-field regime. Using events detected by LIGO-Virgo up to 1 October 2019, we evaluate the consistency of the ...data with predictions from the theory. We first establish that residuals from the best-fit waveform are consistent with detector noise, and that the low- and high-frequency parts of the signals are in agreement. We then consider parametrized modifications to the waveform by varying post-Newtonian and phenomenological coefficients, improving past constraints by factors of ∼2; we also find consistency with Kerr black holes when we specifically target signatures of the spin-induced quadrupole moment. Looking for gravitational-wave dispersion, we tighten constraints on Lorentz-violating coefficients by a factor of ∼2.6 and bound the mass of the graviton to m(g)≤1.76 x 10^(-23) eV/sq. c with 90% credibility. We also analyze the properties of the merger remnants by measuring ringdown frequencies and damping times, constraining fractional deviations away from the Kerr frequency to δ{\hat {f}}(220)=0.03(+0.38,-0.35) for the fundamental quadrupolar mode, and δ{\hat {f}}(221)=0.04(+0.27,-0.32) for the first overtone; additionally, we find no evidence for postmerger echoes. Finally, we determine that our data are consistent with tensorial polarizations through a template-independent method. When possible, we assess the validity of general relativity based on collections of events analyzed jointly. We find no evidence for new physics beyond general relativity, for black hole mimickers, or for any unaccounted systematics.
The goal of this work was to investigate the use of MDCK (Madin–Darby canine kidney) cells as a possible tool for assessing the membrane permeability properties of early drug discovery compounds. ...Apparent permeability (Papp) values of 55 compounds with known human absorption values were determined using MDCK cell monolayers. For comparison, Papp values of the same compounds were also determined using Caco‐2 cells, a well‐characterized in vitro model of intestinal drug absorption. Monolayers were grown on 0.4‐µm Transwell‐COL membrane culture inserts. MDCK cells were seeded at high density and cultured for 3 days, and Caco‐2 cells were cultured under standard conditions for 21 to 25 days. Compounds were tested using 100 µM donor solutions in transport medium (pH 7.4) containing 1% DMSO. The Papp values in MDCK cells correlated well with those in Caco‐2 cells (r2 = 0.79). Spearman's rank correlation coefficient for MDCK Papp and human absorption was 0.58 compared with 0.54 for Caco‐2 Papp and human absorption. These results indicate that MDCK cells may be a useful tool for rapid membrane permeability screening.
We report the observation of gravitational waves from a binary-black-hole coalescence during the first two weeks of LIGO’s and Virgo’s third observing run. The signal was recorded on April 12, 2019 ...at05∶30∶44 UTC with a network signal-to-noise ratio of 19. The binary is different from observations during the first two observing runs most notably due to its asymmetric masses: a∼30M⊙black hole merged with a ∼8M⊙black hole companion. The more massive black hole rotated with a dimensionless spin magnitude between 0.22 and 0.60 (90% probability). Asymmetric systems are predicted to emit gravitational waves with stronger contributions from higher multipoles, and indeed we find strong evidence for gravitational radiation beyond the leading quadrupolar order in the observed signal. A suite of tests performed onGW190412 indicates consistency with Einstein’s general theory of relativity. While the mass ratio of this system differs from all previous detections, we show that it is consistent with the population model of stellar binary black holes inferred from the first two observing runs.
Hemolytic uremic syndrome (HUS) is a rare disease primarily characterized by hemolytic anemia, thrombocytopenia, and acute renal failure. Endothelial damage is the hallmark of the pathogenesis of HUS ...with an infection with the Shiga toxin (Stx) producing
(STEC-HUS) as the main underlying cause in childhood. In this study, blood outgrowth endothelial cells (BOECs) were isolated from healthy donors serving as controls and patients recovered from STEC-HUS. We hypothesized that Stx is more cytotoxic for STEC-HUS BOECs compared to healthy donor control BOECs explained via a higher amount of Stx bound to the cell surface. Binding of Shiga toxin-2a (Stx2a) was investigated and the effect on cytotoxicity, protein synthesis, wound healing, and cell proliferation was studied in static conditions. Results show that BOECs are highly susceptible for Stx2a. Stx2a is able to bind to the cell surface of BOECs with cytotoxicity in a dose-dependent manner as a result. Pre-treatment with tumor necrosis factor alpha (TNF-α) results in enhanced Stx binding with 20-30% increased lactate dehydrogenase (LDH) release. Endothelial wound healing is delayed in a Stx2a-rich environment; however, this is not caused by an effect on the proliferation rate of BOECs. No significant differences were found between control BOECs and BOECs from recovered STEC-HUS patients in terms of Stx2a binding and inhibition of protein synthesis.
Voltage-activated adhesion is a relatively new discovery that relies on direct currents for initiation of cross-linking. Previous investigations have found that direct currents are linearly ...correlated to the migration rates of electrocuring, but this is limited by high voltages exceeding 100 V with instances of incomplete curing of voltage-activated adhesives on semiconducting substrates. Practical applications of electrocuring would benefit from lower voltages to mitigate high-voltage risks, especially with regard to potential medical applications. Alternative electrocuring strategies based on alternating current (AC), electrolyte ionic radius, and temperature are evaluated herein. Square-waveform AC electric field is hypothesized to initiate a two-sided curing progression of voltage-activated adhesive (PAMAM-g-diazirine, aka Voltaglue), where initiation occurs at the cathode terminal. Structure–activity relationships of Voltaglue as a function of AC frequency at currents of 1–3 mA are evaluated against direct currents, migration rate, storage modulus, and lap-shear adhesion on ex vivo tissue mimics. Numerous improvements in electrocuring are observed with AC stimulation vs direct current, including a 35% decrease in maximum voltage, 180% improvement in kinetic rates, and 100% increase in lap-shear adhesion at 2 mA. Li+ ion electrolytes and curing at 4 °C shifts curing kinetics by +104% and −22% respectively, with respect to the control ion (Na+ ion at 24 °C), suggesting that electrolyte migration is the rate-limiting step. Li+ ion electrolytes and curing at 50 °C improve storage modulus by 110% and 470%, respectively. Further evaluations of electrocured matrices with 19F NMR, solid-state NMR, and infrared spectroscopy provide insights into the probable cross-linking mechanisms.
Summary
Recent studies have shown that some mammalian microRNAs (miRNAs) play a role in antiviral defence. However, little is known about the role of miRNA‐323b in hepatitis B virus (HBV)‐host ...interaction. We explored whether single nucleotide polymorphism (SNP) of miRNA‐323b affects HBV replication in a Korean HBV cohort. Genotyping was performed in a total of 1439 subjects composed of 404 spontaneously recovered (SR) subjects as normal controls and 1035 chronic carriers (CC) of HBV who were further classified into 313 patients with chronic hepatitis, 305 patients with liver cirrhosis and 417 patients with hepatocellular carcinoma. To confirm the effect of SNP of miRNA‐323b on HBV replication in vitro, HepAD38 cells were transfected with miRNA‐323b wild type or miRNA‐323b SNP plasmid vectors, and HBV replication was induced for 5 days. HBV DNA was isolated and quantified using real‐time PCR. The polymorphism rs56103835C>T in the pre‐miRNA region of miRNA‐323b revealed significant minor allele frequency (0.273). rs56103835C>T SNP showed significantly affect persistence of HBV in CC group compared with SR group (OR = 1.29, P = 0.009 in a codominant model; OR = 1.29, P = 0.03 in a dominant model; and OR = 1.78, P = 0.03 in a recessive model). In vitro, the total intracellular HBV DNA content was significantly reduced by miRNA‐323b wild‐type plasmid vector transfection (P = 0.014). The polymorphism of miRNA‐323b was significantly associated with persistence of HBV by the enhancement of HBV replication (P = 0.021). Our findings provide a novel perspective on the role SNP of miRNAs in host–virus interactions in HBV infection.
Magnetic fields are applied to inductively coupled plasma (ICP) to achieve high plasma densities using electromagnets. If the magnetic fields are set up such that the magnitude of magnetic flux ...density on the substrate decreases with both radial and axial distances from the substrate's center (here after referred to as M-ICP-A), the plasma density increases by 237% compared with that for ICP although the non-uniformity of the plasma density for M-ICP-A (11.1%) is higher than that for ICP (10.9%). As the rate of decrease in the magnitude of magnetic flux density on the substrate increases both radially and axially, the non-uniformity in the plasma density increases further. The increase in the non-uniformity for M-ICP-A was confirmed to arise from the flute instability. To suppress the flute instability, we arranged the magnitude of magnetic flux density on the substrate to increase with increasing distance from the substrate center both radially and axially (here after referred to as M-ICP-V). In this configuration, plasma fluctuations were not observed, hence the plasma density non-uniformity was lowered to 8.1%, although the measured plasma density was higher than that for M-ICP-A. The oxide etch-rate non-uniformity in M-ICP-V (2.5%) was also lower than that for ICP (5.2%) or that for M-ICP-A (21.4%).
The conical spin order of multiferroic CoCr2O4 has been studied by a neutron diffraction to investigate its magnetic phase transitions at temperatures below 40 K. Magnetic order of a spiral spin ...component with an incommensurate propagation vector of (0.6,0.6,0) was observed at 26 K, while at 14.5 K, the incommensurate conical spin order showed a transition into the fixed commensurate propagation vector of (2/3,2/3,0). In addition, two satellite peaks with propagation vectors of (0.035,,0) and (,0.03,0) from the commensurate vector were observed. The widths of these peaks indicate a long-range magnetic order. This new magnetic configuration below 14.5 K may lead to a new model of multiferroic behavior differing from the well-known spin-current model for magnetic ferroelectricity.
In this paper, newly designed magnetized inductively coupled plasma ion beam etcher (M-ICP IBE) is proposed. Plasma density and electron temperature were measured with respect to the magnetic flux ...density and to the source power. In addition, ion energy distribution and ion flux, the result of which were correlated with plasma density and electron temperature characteristics, were measured. The relationship among plasma density, electron temperature, and the diameter of a screen grid hole were also studied in order to extract optimized ion beam from the grid layer. Besides, the ion beam characteristics with respect to the screen grid voltage and to the acceleration grid voltage were investigated. Meanwhile, the dry etching characteristics of SiO2 in ICP IBE and that of M-ICP IBE were investigated. It was confirmed that the beam extracted from the grid layer in M-ICP IBE showed high ion flux even at low ion energy, where ICP IBE showed much lower ion flux. As a result, the etch rate of SiO2 in M-ICP IBE was about seven times higher than that in ICP IBE.
PDF
