Coupling system of silver carbonate nanoparticles and bismuth oxyiodide nanosheets with enhanced photocatalytic properties

274-284In this work, silver carbonate nanoparticles and BiOI nanosheets have been prepared separately and binary Ag2CO3/BiOI composite are synthesized via a facile solvo thermal method. The as-prepared materials have been well characterized using techniques covering X-ray diffraction (XRD), energy dispersive X-ray spectroscopy (EDX), transmission electron microscopy (TEM), High-resolution transmission electron microscopy (HRTEM), ultraviolet-visible (UV-vis) diffuse reflectance spectroscopy, X-ray photoelectron spectroscopy (XPS), Photoluminescence (PL) emission spectroscopy. The photocatalytic activity of the as-synthesized materials has been evaluated for degrading various model pollutants (methyl orange, phenol and p-nitroaniline). It has been found that the incorporation of co-catalyst BiOI could promote the catalytic activity of Ag2CO3 and suppress the serious photocorrosion of Ag2CO3. Thus the Ag2CO3/BiOI composite showed excellent catalytic recycling stability. Moreover, the underlying mechanism has been investigated through radical trapping experiments. The results demonstrate that photoinduced holes are the main active species. The improvement in activity of Ag2CO3/BiOI could be attributed to the charge transfer between the heterojunction. Also, its good stability and reusability establish its promising potential for catalytic applications

Construction of magnetic BiOBr@Fe3O4 hybrid nanoparticles via a sol-gel route for photocatalysis application

663-673Development of a highly active visible-light-driven and magnetically recyclable photocatalyst is a challenge for chemical use of solar energy. In this study, Fe3O4 nanoparticles (NP), BiOBr and a superior magnetic separable BiOBr@Fe3O4 hybrid material have been synthesized via a facile chemical method. The structures, morphological, optical and physical properties of as-synthesized samples have been characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), ultraviolet-visible (UV-vis) diffuse reflectance spectroscopy, X-ray photoelectron spectroscopy (XPS), Fourier transforminfrared (FT-IR) spectroscopy, photoluminescence (PL) spectroscopy. The photocatalytic activity of the as-synthesized materials is evaluated by photocatalytic degradation of aromatic, heterocyclic organic compound such as methylene blue (MB) and 85% of MB could be removed by BiOBr@Fe3O4 hybrid within 60 min. It is found that the composite yield a significantly larger amount of hydroxyl radicals through free radical scavenging test. It is proposed that the observed synergistic effect between Fe3O4 and BiOBr is due to the charge transfer between the two oxides, improving the separation of the photogenerated charge carriers via the Z-scheme mechanism, and thus accelerating the photocatalytic degradation of MB and leading to high photocatalytic stability of BiOBr@Fe3O4 material

Role of p53 in pseudorabies virus replication, pathogenicity, and host immune responses

International audienceAbstractAs a key cellular transcription factor that plays a central role in cellular responses to a broad range of stress factors, p53 has generally been considered as a host cell restriction factor for various viral infections. However, the defined roles of p53 in pseudorabies virus (PRV) replication, pathogenesis, and host responses remain unclear. In the present study, we initially constructed a p53 overexpressing a porcine kidney epithelial cell line (PK-15) to detect the effect of p53 on PRV replication in vitro. The results show that viral glycoprotein B (gB) gene copies and the titers of virus were significantly higher in p53 overexpressing PK-15 cells than in PK-15 and p53 inhibitor treated p53 overexpressing PK-15 cells. A similar result was also found in the p53 inhibitor PFT-α-treated PK-15 cells. We then examined the effects of p53 on PRV infection in vivo by using p53-knockout (p53−/−) mice. The results show that p53 knockout not only led to significantly reduced rates of mortality but also to reduced viral replication and development of viral encephalitis in the brains of mice following intracranial inoculation. Furthermore, we examined the effect of p53 knockout on the expression of the reported host cell regulators of PRV replication in the brains of mice by using RNA sequencing. The results show that p53 knockout downregulated the interferon (IFN) regulator genes, chemokine genes, and antiviral genes after PRV infection. This finding suggests that p53 positively regulates viral replication and pathogenesis both in vitro and in vivo. These findings offer novel targets of intrinsic host cell immunity for PRV infection

Effect of acupuncture in the acute phase of intracerebral hemorrhage on the prognosis and serum BDNF: a randomized controlled trial

BackgroundIntracerebral hemorrhage (ICH) is a common cerebrovascular disease, with a high rate of disability. In the literature on Chinese traditional medicine, there is increasing evidence that acupuncture can help hematoma absorption and improve neurological deficits after cerebral hemorrhage. Brain-derived neurotrophic factor (BDNF), one of the most studied neurotrophic factors, is involved in a variety of neurological functions and plays an important role in brain injury recovery. We investigated the effect of acupuncture intervention in the acute phase of ICH on the prognosis and serum BDNF levels of several patient groups.ObjectiveTo investigate the influence of acupuncture on the prognosis and brain-derived neurotrophic factor (BDNF) levels in patients in the acute phase of ICH.MethodsFrom November 2021 to May 2022, 109 subjects were consecutively enrolled, including patients with ICH, who were randomized into the acupuncture group (AG) and sham acupuncture group (SAG), and a control group (CG). The CG received the same acupuncture intervention as the AG, and the SAG received sham acupuncture, with 14 interventions in each group. The level of consciousness of patients with ICH was assessed and serum BDNF levels were measured in all three groups before the intervention and at 3 weeks after onset, and the level of consciousness and outcomes were assessed at 12 weeks after onset.ResultsAfter the intervention, the level of consciousness of the AG improved significantly (P < 0.05); the BDNF level of only the AG increased significantly (P < 0.05); the changes in Glasgow Coma Scale (GCS) score and BDNF level were significantly greater in the AG than in the SAG (P < 0.05), especially for locomotion (P < 0.05). At 12 weeks post-onset, the AG showed better outcomes and recovery of consciousness than the SAG (P < 0.05)

Experimental and analytical analysis of polarization and water transport behaviors of hydrogen alkaline membrane fuel cell

Experimental test and analytical modeling are conducted to investigate the operating behavior of an alkaline electrolyte membrane (AEM) fuel cell fed by H2/air (or O2) and explore the effect of various operating pressures on the water transfer mechanism. According to the experimental test, the cell performance is greatly improved through increasing the operating pressure gradient from anode to cathode which leads to significant liquid water permeation through the membrane. The high frequency resistance of the A901 alkaline membrane is observed to be relatively stable as the operating pressure varies based on the electrochemical impedance spectroscopy (EIS) method. Correspondingly, based on the modeling prediction, the averaged water content in the membrane electrode assembly (MEA) does not change too much which leads to the weak variation of membrane ohmic resistance. This reveals that the performance enhancement should give the credit to better electro-chemical reaction kinetics for both the anode and cathode, also prone by the EIS results. The reversion of water back diffusion direction across the membrane is also observed through analytical solution

A Gigantic Mid-Infrared Outburst in an Embedded Class-I Young Stellar Object J064722.95+031644.6

We report the serendipitous discovery of a giant mid-infrared (MIR) outburst from a previously unknown source near a star-forming region in the constellation Monoceros. The source gradually brightened by a factor of 5 from 2014 to 2016 before an abrupt rise by a factor of more than 100 in 2017. A total amplitude increase of >500 at 4.5 microns has since faded by a factor of about 10. Prior to the outburst, it was only detected at wavelengths longer than 1.8 microns in UKIDSS, Spitzer, and Herschel with a spectral energy distribution of a Class I Young Stellar Object (YSO). It has not been detected in recent optical surveys, suggesting that it is deeply embedded. With a minimum distance of 3.5 kpc, the source has a bolometric luminosity of at least 9 $L_\odot$ in the quiescent state and 400 $L_\odot$ at the peak of the eruption. The maximum accretion rate is estimated to be at least a few $10^{-5}$ $M_\odot$ year$^{-1}$. It shares several common properties with another eruptive event, WISE~J142238.82-611553.7: exceptionally large amplitude, featureless near-infrared spectrum with the exception of H_2 lines, intermediate eruption duration, an embedded Class I YSO, and a low radiative temperature (<600-700 K) in outburst. We interpret that the radiation from the inner accretion disk and young star is obscured and reprocessed by either an inflated outer disk or thick dusty outflow on scales > 6.5 AU during the outburst.Comment: 15 pages, 7 figures, accepted to Ap

Solvent-Free Electrolyte for High-Temperature Rechargeable Lithium Metal Batteries

The formation of lithiophobic inorganic solid electrolyte interphase (SEI) on Li anode and cathode electrolyte interphase (CEI) on the cathode is beneficial for high-voltage Li metal batteries. However, in most liquid electrolytes, the decomposition of organic solvents inevitably forms organic components in the SEI and CEI. In addition, organic solvents often pose substantial safety risks due to their high volatility and flammability. Herein, an organic-solvent-free eutectic electrolyte based on low-melting alkali perfluorinated-sulfonimide salts is reported. The exclusive anion reduction on Li anode surface results in an inorganic, LiF-rich SEI with high capability to suppress Li dendrite, as evidenced by the high Li plating/stripping CE of 99.4% at 0.5 mA cm−2 and 1.0 mAh cm−2, and 200-cycle lifespan of full LiNi0.8Co0.15Al0.05O2 (2.0 mAh cm−2) || Li (20 µm) cells at 80 °C. The proposed eutectic electrolyte is promising for ultrasafe and high-energy Li metal batteries