A new spirocyclic γ-lactam, named spirostaphylotrichin X (1), and three related known spirostaphylotrichins (2–4) were isolated from the marine-derived fungus Cochliobolus lunatus SCSIO41401. Their ...structures were determined by spectroscopic analyses. Spirostaphylotrichin X (1) displayed obvious inhibitory activities against multiple influenza virus strains, with IC50 values from 1.2 to 5.5 μM. Investigation of the mechanism showed that 1 inhibited viral polymerase activity and interfered with the production of progeny viral RNA. Homogeneous time-resolved fluorescence, surface plasmon resonance assays, and a molecular docking study revealed that 1 could inhibit polymerase PB2 protein activity by binding to the highly conserved region of the cap-binding domain of PB2. These results suggest that 1 inhibits the replication of influenza A virus by interfering with the activity of PB2 protein and that 1 represents a new type of potential lead compound for the development of anti-influenza therapeutics.
Black holes entangled by radiation Liu, Yuxuan; Xian, Zhuo-Yu; Peng, Cheng ...
The journal of high energy physics,
09/2022, Volume:
2022, Issue:
9
Journal Article
Peer reviewed
Open access
A
bstract
We construct three models to describe the scenario where two eternal black holes are separated by a flat space, and can eventually be entangled by exchanging radiation. In the doubly ...holographic setup, we compute the entanglement entropy and mutual information among subsystems and obtain the dynamic phase structure of the entanglement. The formation of entanglement between these two black holes is delayed by the space which the radiation must travel through. If the black holes exchange sufficient Hawking modes, the final state is characterized by a connected entanglement wedge; otherwise, the final entanglement wedge contains two separate islands. In the former case, the entanglement wedge of the black holes forms at the time scale proportional to the size of the flat space between them. While in both cases, the unitarity of the evolution is preserved. When the sizes of the black holes are not equal, we observe a loss of entanglement between the smaller black hole and the radiation at late times. On the field theory side, we consider two Sachdev-Ye-Kitaev (SYK) clusters coupled to a Majorana chain, which resemble two black holes connected by a radiation region. We numerically compute the same entanglement measures and obtain similar phase structures as the bulk results. In general, a time delay of the entanglement between the SYK clusters is found in cases with a long Majorana chain. In particular, when the SYK clusters are different in size, similar entanglement loss between the smaller SYK cluster and the Majorana chain is observed. Finally, we investigate a chain model composed of EPR clusters with particles exchanging between neighboring clusters and reproduce the features of entanglement observed in the previous models.
Boron-doped TiO2 was supported on HZSM-5 zeolite in a sol-gel route to prepare B-TiO2(x%)/HZSM-5 composites. The composites are composed of anatase TiO2 and HZSM-5 zeolite. The crystallite size of ...anatase TiO2 decreases after loading B-TiO2 on HZSM-5 zeolite. The SEM and TEM images of the composite show the dispersion of the B-TiO2 crystals on the external surface of HZSM-5. The bandgap energies of B-TiO2(x%)/HZSM-5 composites are approximately 3.2 eV. The N2 adsorption-desorption isotherms indicate that B-TiO2 is a mesoporous material and HZSM-5 zeolite is a microporous material. The mesoporous B-TiO2 layer is loaded on the external surface of the zeolite and does not enter into the inner micropores. The XPS results indicate the unchanged chemical environments of both titanium and oxygen in the supported B-TiO2. The B-TiO2(x%)/HZSM-5 composites have higher photocatalytic activity than the unsupported B-TiO2. The optimum B-TiO2 loading content is 20% in the composite, and 55.3% of the original ofloxacin molecules were degraded on the sample after 30 min of irradiation. Photocatalytic oxidation not only causes breaking up of the ofloxacin molecules, but also leads to decomposition of the major functional groups of the ofloxacin molecules.
Multi-frequency power ultrasound was applied as an environmentally friendly technique to control the nanoparticles (LS/XG-NPs) embedded with lotus root starch/xanthan gum, with the aim of enhancing ...the stability of Pickering emulsions. The present investigation was centered on evaluating the impact of ultrasound technology on various aspects of the emulsions, encompassing their mean particle size, particle size distribution, zeta potential, microstructure, rheological characteristics, and environmental stability. The findings of this study indicate that ultrasonic treatment enhanced the adsorption of LS/XG-NP onto oil droplets surface, resulting in a reduction in their size. Additionally, ultrasonic treatment decreased the viscosity and Brownian motion rate of the emulsion stabilized by LS/XG-NP, leading to increased fluidity. Furthermore, the emulsion's thermal stability and resistance to environmental oxidation were significantly enhanced through ultrasonic treatment. The Pickering emulsions that were prepared using ultrasound demonstrated excellent resistance to acid, alkali (pH 2-8) and salt ions (50-300 mM NaCl) for a period of 30 days during storage. It was worth anticipating that ultrasound-assisted LS/XG-NPs could efficiently retard the volatilization of fishy odor components within fish oil. Taken together, the present research has evinced the efficacy of ultrasound in enhancing the stability of Pickering emulsions coated with LS/XG-NPs. These findings offer significant novel insights into the advancement of ultrasound-assisted Pickering emulsions that are stabilized with starch-based or biopolymeric materials.
Bisphenol Z (BPZ), bisphenol S (BPS), bisphenol C (BPC), and bisphenol F (BPF) had been widely used as alternatives to bisphenol A (BPA), but the toxicity data of these bisphenol analogues were very ...limited. In this study, the joint toxicity of BPZ, BPS, BPC, and BPF to zebrafish (
) was investigated. The median half lethal concentrations (LC50) of BPZ, BPS, BPC, and BPF to zebrafish for 96 h were 6.9 × 10
µM, 3.9 × 10
µM, 7.1 × 10
µM, and1.6 × 10
µM, respectively. The joint toxicity effect of BPF-BPC (7.7 × 10
-3.4 × 10
µM) and BPZ-BPC (3.4 × 10
-3.5 × 10
µM) with the same toxic ratio showed a synergistic effect, which may be attributed to enzyme inhibition or induction theory. While the toxicity effect of the other two bisphenol analogue combined groups and multi-joint pairs showed an antagonistic effect due to the competition site, other causes need to be further explored. Meanwhile, the expression levels of the estrogen receptor genes (ERα, ERβ1) and antioxidant enzyme genes (SOD, CAT, GPX) were analyzed using a quantitative real-time polymerase chain reaction in zebrafish exposure to LC
of BPZ, BPS, BPC, and BPF collected at 24, 48, 72, and 96 h. Relative expression of CAT, GPX, and ERβ1 mRNA declined significantly compared to the blank control, which might be a major cause of oxidant injury of antioxidant systems and the disruption of the endocrine systems in zebrafish.
Racial/ethnic disparities are among the top-selective underlying determinants associated with the disproportional impact of the COVID-19 pandemic on human mobility and health outcomes. This study ...jointly examined county-level racial/ethnic differences in compliance with stay-at-home orders and COVID-19 health outcomes during 2020, leveraging two-year geo-tracking data of mobile devices across ~4.4 million point-of-interests (POIs) in the contiguous United States. Through a set of structural equation modeling, this study quantified how racial/ethnic differences in following stay-at-home orders could mediate COVID-19 health outcomes, controlling for state effects, socioeconomics, demographics, occupation, and partisanship. Results showed that counties with higher Asian populations decreased most in their travel, both in terms of reducing their overall POIs’ visiting and increasing their staying home percentage. Moreover, counties with higher White populations experienced the lowest infection rate, while counties with higher African American populations presented the highest case-fatality ratio. Additionally, control variables, particularly partisanship, median household income, percentage of elders, and urbanization, significantly accounted for the county differences in human mobility and COVID-19 health outcomes. Mediation analyses further revealed that human mobility only statistically influenced infection rate but not case-fatality ratio, and such mediation effects varied substantially among racial/ethnic compositions. Last, robustness check of racial gradient at census block group level documented consistent associations but greater magnitude. Taken together, these findings suggest that US residents’ responses to COVID-19 are subject to an entrenched and consequential racial/ethnic divide.
China’s Chang’e-4 (CE-4) mission is the first human lander/rover mission on the far side of the Moon. Its probe is composed of a lander, rover, and the Queqiao relay satellite. Queqiao was ...successfully launched on May 21, 2018, and entered the halo orbit of the L2 point on June 14, becoming the first satellite connecting the Earth and the Moon’s far side. The lander carrying Yutu-2 was successfully launched on December 8, 2018, and landed in the Von Kármán crater (45.5° S, 177.6° E) at 10:26 (UTC+8) on January 3, 2019. The CE-4 probe carried nine science instruments. Four instruments are on the lander: a landing camera (LCAM), a terrain camera (TCAM), a low-frequency radio spectrometer (LFRS), and a lunar lander neutrons and dosimetry (LND) provided by Germany. Four instruments are on the rover: a panoramic camera (PCAM), a visible and near-infrared imaging spectrometer (VNIS), a lunar penetrating radar (LPR), and an advanced small analyzer for neutrals (ASAN) provided by Sweden. The instrument on the relay satellite is the Netherlands-China Low-Frequency Explorer (NCLE). The scientific objectives of the CE-4 mission include (1) performing low-frequency radio-astronomical observations; (2) investigating the geomorphology, mineral compositions and shallow subsurface structure of the landing and roving sites; and (3) detecting the Earth-Moon space environment at the lunar far side. As of February 1, 2020, CE-4 has completed 14 lunar days of scientific exploration after one year of operation. The components, fight, scientific objectives and investigation of CE-4 are introduced in this paper. We also describe the accessibility of the initial archived science data and their preliminary analysis results.
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•Hierarchical PAN/PPy/MnO2 nanofiber was prepared.•Hierarchical PAN/PPy/MnO2 nanofiber mat was used to remove Pb(II).•Adsorption capacity for Pb(II) is 251.90mg/g.•Adsorption ...performance remained up to 80% within 5 times cycles.
Hierarchical nanofiber mat (polyacrylonitrile/polypyrrole/manganese dioxide, PAN/PPy/MnO2) was prepared by electrospinning and followed by in situ polymerization of pyrrole monomer, and subsequently treated with KMnO4 solution to deposit MnO2. The obtained nanofiber mats were used as adsorbent for Pb(II) removal from aqueous solution. Fourier transform infrared (FTIR) results confirmed the presence of polypyrrole (PPy) and manganese dioxide (MnO2) layers on the surface of PAN nanofiber. The morphology and structure of the PAN/PPy/MnO2 nanofiber mat were studied by scanning electron microscopy (SEM) and transmission electron microscope (TEM). The hierarchical structures can be clearly seen from the SEM and TEM results. Thermo-gravimetric analysis (TGA) results showed that MnO2 accounts for about 9.25wt.% in the PAN/PPy/MnO2 nanofiber. Adsorption results indicated that the adsorption performance for Pb(II) increased as the initial solution pH increased. The adsorption equilibrium reached within 120min, and the process can be better described using the pseudo-second-order model. Isotherm data fitted well to the Langmuir isotherm model. Thermodynamic study revealed that the adsorption process is endothermic and spontaneous in nature. Desorption results showed that the adsorption performance can remain up to 80% after 5 times usage. The adsorption mechanism was also studied by XPS.
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