We revisit the global 21 cm signal calculation incorporating a possible radio background at early times, and find that the global 21 cm signal shows a much stronger absorption feature, which could ...enhance detection prospects for future 21 cm experiments. In light of recent reports of a possible low-frequency excess radio background, we propose that detailed 21 cm calculations should include a possible early radio background.
Photocatalysis, as a potential green technology, can effectively degrade organic pollutants. The changes of the intermediate products in the photocatalytic degradation process of pollutants are ...particularly important for studying the degradation mechanism. In the present paper, ZnO porous nanorod (NR), ZnO/Ag and ZnO/Ag/Ag
2
O photocatalysts were prepared and their photocatalytic phenol degradation performance and processes were investigated. ZnO/Ag/Ag
2
O displays a significantly enhanced photocatalytic phenol degradation performance with complete degradation of phenol in only 90 min of white light illumination. Except for the direct ring-opening reaction of phenol, hydroquinone is the main intermediate product for the ZnO NRs and ZnO/Ag in the photocatalytic phenol degradation process. However, for the ZnO/Ag/Ag
2
O photocatalyst, the Ag/Ag
2
O nanoparticles (NPs) act as acceptors of the photogenerated electrons and play an important role in the phenol degradation process. Different from the ZnO NRs and ZnO/Ag, ZnO/Ag/Ag
2
O can selectively catalyze the formation of the
p
-benzoquinone intermediate due to the generation of a large amount of &z.rad;O
2
−
through the mutual conversion of Ag
0
and Ag
+
on the Ag/Ag
2
O NPs. Therefore, ZnO/Ag/Ag
2
O accelerates the oxidation and degradation of phenol to carbon dioxide and water through different intermediate processes under white light illumination.
ZnO/Ag/Ag
2
O accelerates phenol degradation through different intermediate processes under white light illumination.
In this study, we investigate the ameliorating functions of QDYD (MSP2), ARW (MSP8), DDGGK (MSP10), YPAGP (MSP13) and DPAGP (MSP18) from monkfish swim bladders on an FFA-induced NAFLD model of HepG2 ...cells. The lipid-lowering mechanisms revealed that these five oligopeptides can up-regulate the expression of phospho-AMP-activated protein kinase (
-AMPK) proteins to inhibit the expression of the sterol regulatory element binding protein-1c (SREBP-1c) proteins on increasing lipid synthesis and up-regulating the expression of the PPAP-α and CPT-1 proteins on promoting the β-oxidation of fatty acids. Moreover, QDYD (MSP2), ARW (MSP8), DDGGK (MSP10), YPAGP (MSP13) and DPAGP (MSP18) can significantly inhibit reactive oxygen species' (ROS) production, promote the activities of intracellular antioxidases (superoxide dismutase, SOD; glutathione peroxidase, GSH-PX; and catalase, CAT) and bring down the content of malondialdehyde (MDA) derived from lipid peroxidation. Further investigations revealed that the regulation of these five oligopeptides on oxidative stress was achieved through activating the nuclear factor erythroid 2-related factor 2 (Nrf2) pathway to raise the expression levels of the heme oxygenase 1 (HO-1) protein and downstream antioxidant proteases. Therefore, QDYD (MSP2), ARW (MSP8), DDGGK (MSP10), YPAGP (MSP13) and DPAGP (MSP18) could serve as candidate ingredients to develop functional products for treating NAFLD.
Promoting copper catalysts with C60Ethylene glycol, a commodity chemical used as a feedstock and antifreeze agent, is synthesized industrially from dimethyl oxalate (DMO) by hydrogenation over ...precious-metal palladium catalysts at high pressures (typically 20 bars). Copper-chromium catalysts supported on silica as an alternative have required even high pressures. Zheng et al. show the addition of fullerene (C60) onto copper-silica allows DMO hydrogenation to be performed at ambient pressures with high yield (98%) and without deactivation after 1000 hours (see the Perspective by Gravel and Doris). The use of C60 to stabilize electron-deficient copper species that enhance hydrogen adsorption could likely be applied to other hydrogenation reactions catalyzed by copper. —PDS
A
bstract
Global cosmic strings are predicted in many motivated extensions to the Standard Model of particle physics, with close connections to axion dark matter physics. Recent studies suggest that, ...although subdominant relative to Goldstone emission, gravitational wave (GW) signals from global strings can be detectable with current and planned GW detectors such as LIGO, LISA, DECIGO/BBO, ET/CE and AEDGE/AION, as well as pulsar timing arrays such as PPTA, NANOGrav and SKA. This work is an extensive, updated study on GWs from a global cosmic string network, taking into account of the most recent developments related to the subject. The main analysis is based on the analytical Velocity-dependent One-Scale (VOS) model calibrated with recent simulation results, which provides a generic protocol for such calculations with details given. We also demonstrate how the GW signal can be influenced with variations to the baseline model: this includes considering the uncertainties of model parameters and the potential deviation from the conventional VOS model prediction (i.e. the scaling behavior) as suggested by some of the recent simulation results. Furthermore, we investigated in detail the effect of a non-standard cosmology (e.g. early matter domination or kination) or new particle species on the GW signals from global strings. We demonstrate that the frequency spectrum of GW background from global cosmic strings can be used to probe the cosmic history prior to the Big Bang nucleosynthesis (BBN) (i.e. the primordial dark age) up to a temperature of
T
∼ 10
8
GeV.
2D hybrid halide double perovskites (HHDPs) have been demonstrated to be a promising alternative to conventional lead‐based halide perovskites as a new system of photoferroelectrics, due to their ...unique characteristics of environmental friendliness, favorable stability, and fascinating optoelectronic properties. Herein, for the first time, a 2D iodide double perovskite photoferroelectric is reported based on Ag/Sb ions, (4,4‐DFPD)4AgSbI8 (4,4‐DFPD = 4,4‐difluoropiperidinium), which possesses a high Curie temperature of 414 K (above BaTiO3), a large spontaneous polarization of 9.6 μC cm−2, ferroelectric photovoltaic effect, and photostrictive effect. Notably, to the best of the authors’ knowledge, the discovery of photostriction in HHDP photoferroelectrics is unprecedented. Moreover, (4,4‐DFPD)4AgSbI8 exhibits an impressive X‐ray responsivity, with a sensitivity as high as 704.8 μC Gyair−1 cm−2 at 100 V bias and a detection limit as low as 0.36 μGyair s−1 at 10 V bias, both of which outperform the current all HHDP photoferroelectrics. This work enriches the photoferroelectric family, and proves that Ag/Sb‐based HHDP photoferroelectrics are a promising candidate for the next‐generation optoelectronic devices.
The first silver/antimony‐based double perovskite photoferroelectric, (4,4‐difluoropiperidinium)4AgSbI8, is discovered, which exhibits ferroelectric photovoltaic effect and photostrictive effect under light radiation. Moreover, (4,4‐difluoropiperidinium)4AgSbI8 exhibits an exciting X‐ray responsivity including a sensitivity as high as 704.8 μC Gyair−1 cm−2 at 100 V bias and a detection limit as low as 0.36 μGyair s–1, both of which are the best among all HHDP photoferroelectrics.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
In the study, papain was chosen from five proteases to hydrolyze proteins of monkfish swim bladders for effectively utilizing monkfish (
) processing byproducts, and the hydrolysis conditions of ...papain were optimized as hydrolysis temperature of 65 °C, pH 7.5, enzyme dose 2.5% and time 5 h using single-factor and orthogonal experiments. Eighteen peptides were purified from the swim bladder hydrolysate of monkfish by ultrafiltration and gel permeation chromatography methods and identified as YDYD, QDYD, AGPAS, GPGPHGPSGP, GPK, HRE, GRW, ARW, GPTE, DDGGK, IGPAS, AKPAT, YPAGP, DPT, FPGPT, GPGPT, GPT and DPAGP, respectively. Among eighteen peptides, GRW and ARW showed significant DPPH· scavenging activities with EC
values of 1.053 ± 0.003 and 0.773 ± 0.003 mg/mL, respectively; YDYD, QDYD, GRW, ARW and YPAGP revealed significantly HO· scavenging activities with EC
values of 0.150 ± 0.060, 0.177 ± 0.035, 0.201 ± 0.013, 0.183 ± 0.0016 and 0.190 ± 0.010 mg/mL, respectively; YDYD, QDYD, ARW, DDGGK and YPAGP have significantly O2-· scavenging capability with EC
values of 0.126 ± 0.0005, 0.112 ± 0.0028, 0.127 ± 0.0002, 0.128 ± 0.0018 and 0.107 ± 0.0002 mg/mL, respectively; and YDYD, QDYD and YPAGP showed strong ABTS
· scavenging ability with EC
values of 3.197 ± 0.036, 2.337 ± 0.016 and 3.839 ± 0.102 mg/mL, respectively. YDYD, ARW and DDGGK displayed the remarkable ability of lipid peroxidation inhibition and Ferric-reducing antioxidant properties. Moreover, YDYD and ARW can protect Plasmid DNA and HepG2 cells against H
O
-induced oxidative stress. Furthermore, eighteen isolated peptides had high stability under temperatures ranging from 25-100 °C; YDYD, QDYD, GRW and ARW were more sensitive to alkali treatment, but DDGGK and YPAGP were more sensitive to acid treatment; and YDYD showed strong stability treated with simulated GI digestion. Therefore, the prepared antioxidant peptides, especially YDYD, QDYD, GRW, ARW, DDGGK and YPAGP from monkfish swim bladders could serve as functional components applied in health-promoting products because of their high-antioxidant functions.
Marine organisms live in harsh marine habitats, causing them to have significantly different and more diverse proteins than those of terrestrial organisms ....
A zero initial velocity of the axion field is assumed in the conventional misalignment mechanism. We propose an alternative scenario where the initial velocity is nonzero, which may arise from an ...explicit breaking of the Peccei-Quinn (PQ) symmetry in the early Universe. We demonstrate that, depending on the specifics of the initial velocity and the time order of the PQ symmetry breaking vs inflation, this new scenario can either enhance or suppress the axion relic abundance relative to the conventional prediction. As a result, new viable parameter regions for axion dark matter may open up.
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CMK, CTK, FMFMET, IJS, NUK, PNG, UM
While many ecological theories have historically invoked niche differences as the primary mechanism allowing species coexistence, we now know that coexistence in competitive communities depends on ...the balance of two opposing forces: niche differences (ND) that determine how species limit their own growth rate versus that of their competitor, and relative fitness differences (RFD) that establish competitive hierarchies among species. Several different empirical methods have been proposed for quantifying ND and RFD in order to make predictions about coexistence between pairs of species, yet it remains unclear which method(s) are appropriate for a given empirical study and whether or not those methods yield the same information. Here we compare six different empirical methods and provide a practical guide to help empiricists determine which method(s) are best for their study system. We show that there are important tradeoffs between mechanistic methods, which require detailed understanding of species’ resource use and physiology but are more tractable experimentally, and phenomenological methods which do not require this detailed information but can be impractical for some study designs. Finally, we show that the methods do not always yield the same values and therefore we caution against future syntheses that compile these estimates from different empirical studies.
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FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
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