A novel heterogeneous manganese/graphitic carbon nitride (Mn3O4-CN) catalyst for activating peroxymonosulfate (PMS) was successfully assembled using alkali precipitation. The g-C3N4 improved the ...composite’s surface morphology, micro-porous structure, surface area, and particle size distribution, and an electron-rich center with Mn site was created. The Mn3O4-CN/PMS system exhibited high efficiency and stability when the solution pH varied from 3.0 to 9.0, with more than 90% of p-acetaminophen (ACT) removal in 30 min under experimental conditions. A possible reaction mechanism was proposed, primarily involving electron transfer from Mn (II) and Mn (III) to PMS along with the generation of·O2- and 1O2, and the degradation of ACT was attributed to the 1O2. Specifically, the degradation rate of phenolic compounds varied with their molecular structure in the following order: ACT > bisphenol A (BPA) > p-cresol (MP) > p-chlorophenol (CP) > phenol (Ph) > p-nitrophenol (NP). Further, the density functional theory (DFT) calculations indicated that the phenols’ degradation efficiency was related to their adsorption energy and Bader charge value. These results improved our understanding of the manganese-based PMS non-radical dominated process and provided a method for predicting the degradation performance of phenols for the first time.
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•Mn3O4-CN exhibited promoting effect on ACT degradation in the PMS activation system.•The PMS activation coordinated with the Mn valence change.•Electron transfer between ACT and high valence Mn renewed the catalyst surface.•ACT degradation was primarily attributed to 1O2.•The structure-dependence degradation of phenols in the PMS system was confirmed.
Many bridge structural components are subjected to repetitive vehicle load and temperature gradient action. The resulting cyclic tensile stresses within the structures could cause premature fatigue ...failure of concrete, dramatically impairing structural components’ durability and sustainability. Although substantial knowledge of fatigue properties on low-strength pavement concrete and high-strength structural concrete has been obtained, research on the most widely used normal-grade ordinary concrete in bridge engineering is still ongoing. Therefore, a four-point bending fatigue test of 97 C50 concrete specimens under a constant amplitude sinusoidal wave was conducted in the laboratory, the flexural fatigue behavior of plain and reinforced concrete specimens was studied, and the cyclic deformation evolution of concrete under fatigue loading was obtained. The empirical fatigue S-N equations of concrete with a failure probability p of 0.1~0.5 were derived through statistical analysis of the test results. The fatigue life of the tested specimens exhibited a two-parameter Weibull distribution. In addition to the maximum stress level Smax, the stress ratio R is also a key factor affecting the flexural fatigue life of concrete N. The semi-logarithmic and logarithmic equations were almost identical at the tested stress levels, the latter predicting longer fatigue life for Smax < 0.70. The restraining effect from steel reinforcement slightly lengthened the concrete’s fatigue cracking initiation life. The insight into concrete flexural fatigue properties from this study not only contributes to a better understanding of structural concrete, but also provides a basis for the practical evaluation of concrete or composite bridge decks.
A number of clinically validated drugs have been developed by repurposing the CUL4-DDB1-CRBN-RBX1 (CRL4CRBN) E3 ubiquitin ligase complex with molecular glue degraders to eliminate disease-driving ...proteins. Here, we present the identification of a first-in-class GSPT1-selective cereblon E3 ligase modulator, CC-90009. Biochemical, structural, and molecular characterization demonstrates that CC-90009 coopts the CRL4CRBN to selectively target GSPT1 for ubiquitination and proteasomal degradation. Depletion of GSPT1 by CC-90009 rapidly induces acute myeloid leukemia (AML) apoptosis, reducing leukemia engraftment and leukemia stem cells (LSCs) in large-scale primary patient xenografting of 35 independent AML samples, including those with adverse risk features. Using a genome-wide CRISPR-Cas9 screen for effectors of CC-90009 response, we uncovered the ILF2 and ILF3 heterodimeric complex as a novel regulator of cereblon expression. Knockout of ILF2/ILF3 decreases the production of full-length cereblon protein via modulating CRBN messenger RNA alternative splicing, leading to diminished response to CC-90009. The screen also revealed that the mTOR signaling and the integrated stress response specifically regulate the response to CC-90009 in contrast to other cereblon modulators. Hyperactivation of the mTOR pathway by inactivation of TSC1 and TSC2 protected against the growth inhibitory effect of CC-90009 by reducing CC-90009-induced binding of GSPT1 to cereblon and subsequent GSPT1 degradation. On the other hand, GSPT1 degradation promoted the activation of the GCN1/GCN2/ATF4 pathway and subsequent apoptosis in AML cells. Collectively, CC-90009 activity is mediated by multiple layers of signaling networks and pathways within AML blasts and LSCs, whose elucidation gives insight into further assessment of CC-90009s clinical utility. These trials were registered at www.clinicaltrials.gov as #NCT02848001 and #NCT04336982).
•SARS-CoV-2 IgM/IgG were assessed from the time of symptom onset up to 210 days.•The positive rate/average titer of IgG within 210 days were 84.3%/43.1 ± 27.0 AU/mL.•The positive rate/average titer ...of IgM within 210 days were 12.0%/4.4 ± 5.2 AU/mL.•SARS‐CoV‐2 IgG/IgM dynamic is mainly affected by age and disease severity, not sex.•IgG threshold reveals that IgG might become undetectable within 30–60 days.
To investigate the dynamic characteristics of serological antibodies against the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which is of much current significance.
The dynamic changes and prevalence of immunoglobulin M (IgM) and immunoglobulin G (IgG) antibodies against SARS-CoV-2 were assessed from the time of symptom onset up to 210 days. Antibodies were detected using a chemiluminescence immunoassay.
The average titers and IgG/IgM positivity rates reached a peak within 30 days of symptom onset and then began to decline continuously. Between 180 and 210 days following symptom onset, the titers of IgG and IgM were 43.1 ± 27.0 AU/mL and 4.4 ± 5.2 AU/mL, respectively, while the respective positivity rates were 84.3% and 12.0%. Further statistical analyses revealed that the dynamic changes and prevalence of the SARS-CoV-2 IgG/IgM antibodies were related to age and disease severity, but not to sex. The dynamic changes and the prevalence were similar for both the IgM and the IgG antibodies. Even so, there was a more rapid rate of decline for the IgM antibodies. It was found that an IgG level of 16.33 ± 3.15 AU/mL may represent a threshold value that should act as an alert, as it may indicate that the IgG level will become undetectable within the next 30–60 days.
The results provide important information concerning COVID-19 and may be of relevance for diagnosis, treatment, and vaccine development.
Magnetic exfoliated graphite (MEG) with high sorption capacity and magnetism was prepared by citric acid sol–gel method. Compared with exfoliated graphite (EG), the characteristics of MEG were ...manifested by scanning electron microscopy, energy diffraction spectroscopy, X-ray diffraction and mercury intrusion pore size distribution. The sorption capacity and rate of MEG were discussed, including the recovery ratios of oils (engine oil, crude oil, diesel oil and gasoline) and the regeneration of MEG. The results show that cobalt ferrite was deposited effectively and uniformly on/in MEG. The myrmekitic and multilevel pore structures of MEG were expanded and developed in comparison with that of EG. The maximum sorption capacity was obtained in about 2
min. The sorption capacity of MEG increased from 41.46 and 40.46
g
g
−
1 to 48.93 and 42.75
g
g
−
1, increased by 18.01% and 5.65% for engine oil and crude oil. While that was decreased from 37.26 and 31.96
g
g
−
1 to 33.18 and 30.48
g
g
−
1 for diesel oil and gasoline, decreased by 10.95% and 4.63% respectively. The average recovery ratios were 77.07%, 78.83%, 85.34% and 88.71%, and the average regeneration ratios were 76.01%, 87.12%, 86.39% and 85.31%. Finally, the experiment to remove heavy oil on surface water easily and conveniently with MEG was simulated.
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•A simple synthetic way for Mn-doped g-C3N4 was developed for the first time.•Complete ACT removal was obtained in a wide pH range of 3.2–9.•The catalytic performance of the MnCN was ...unchanged after using it four times.•The activation of PMS by MnCN was proposed as a 1O2 mediated non-radical way.
Peroxymonosulfate (PMS) is an alternative to hydrogen peroxide in advanced oxidation processes. Herein, we present a simple one-pot synthetic approach for the Mn-doped graphite phase carbon nitride (g-C3N4) materials and make it as a catalyst to activate PMS for acetaminophen (ACT) degradation. Fabricated Mn-g-C3N4 composites (MnCN) were characterized by SEM, EDS, XRD, XPS, and FTIR. Results showed that Mn was uniformly dispersed in the structure of g-C3N4 mostly in the form of Mn-N coordination. The effects of pH, contents of doped Mn, catalyst dosage, and reusability of catalyst and corresponding kinetic study were conducted to determine the catalytic performance of MnCN. High reaction efficiency was obtained in a wide pH range of 3.2–9. 100% removal of ACT in 15 min under optimized conditions with initial pH 6.5, 0.8 g/L of PMS and 200 mg/L of catalyst of 0.5-MnCN. Additionally, the reaction mechanism of the PMS/MnCN system was investigated using the electron spin resonance technique, quenching studies as well as different organics with electron-donating or electron-withdrawing groups. No PMS decomposition was detected without substrates. No inhibition effect by ethanol or tert-Butyl alcohol and complete inhibition effect by benzoquinone and partly by furfuryl alcohol, as well as ESR spectrum of TEMP-1O2 were observed, suggesting that the activation of PMS proceeded in a new way, which is different from traditional sulfate radical-based advanced oxidation processes. A possible mechanism was proposed for ACT removal. PMS was first bounded to Mn-N sites to generate the superoxide anion. Then singlet oxygen produced by superoxide anion would react with ACT by replacing the electron-donating group of acylamino.
Synergistic effects of phages in combination with antibiotics have received increasing attention. In this present study, we isolated a new phage pB3074 against clinically isolated multidrug-resistant ...Acinetobacter baumannii. Phage pB3074 combined with cell wall-targeting antibiotics could produce synergistic antibacterial effect
bactericidal activities. Further research indicates that the bacteriophage dose is critical to synergistic antimicrobial effect of phage and antibiotic combination. Cefotaxime and meropenem were selected as the representative cell wall-targeting antibiotics for further synergistic antibacterial study. Results illustrated that phage pB3074 and cefotaxime or meropenem combination was very effective for the removal of mature biofilm and inhibition of biofilm formation. In a pig skin explant model, results also showed that phage pB3074 and cefotaxime or meropenem combination was very effective for the treatment of wound infection
. Subsequent studies showed that some extent recovery of drug sensitivity to cell wall-targeting antibiotics might be vital mechanism of synergistic antibacterial effect between bacteriophage pB3074 and these antibiotics. The existence of antibiotics could promote phage adsorption and proliferation, which might also be potential mechanism for synergistic antibacterial activities and have been observed in cefotaxime and meropenem application. In summary, results in the current study demonstrated that phage pB3074 has the potential to be developed as an antibacterial agent and combined application of phages and antibiotics might be a new choice for the treatment of current multidrug-resistant bacterial infections.
Combined application of phages and antibiotics cannot only effectively inhibit the appearance of phage-resistant bacteria, but also reduce the effective use concentration of antibiotics, and even make some bacteria regain sensitivity to some resistant antibiotics. Therefore, phage-antibiotic combination (PAC) could improve the antibacterial activity of individual drug, providing a new choice for clinical treatment of multidrug-resistant bacterial infections.
The identification of unknown groundwater pollution sources and the characterization of pollution plume remains a challenging problem. In this study, we addressed this problem by a linked ...simulation-optimization approach. This approach couples a contaminant transport simulation model with a Kalman filter-based method to identify groundwater pollution source and characterize plume morphology. In the proposed methodology, the concentration field library, the covariance reduction with a Kalman filter, an alpha-cut technique of fuzzy set, and a linear programming model are integrated for solving this inverse problem. The performance of this methodology is evaluated on an illustrative groundwater pollution source identification problem. The evaluation considered the random hydraulic conductivity filed, erroneous monitoring data, a prior information shortage of potential pollution sources, and an unexpected and unknown pumping well. The identified results indicate that, under these conditions, the proposed Kalman filter-based optimization model can give satisfactory estimations to pollution sources and plume morphology for domains with small and moderate heterogeneity but cannot validate the transport in the relatively high heterogeneous field.
This study conducts an in-depth study of information security strategies for multi-terminal collaboration software and proposes a cross-platform multi-terminal collaboration software model based on ...cloud computing platforms. The model includes three core components: multi-terminal collaboration software design, cross-platform cloud system, and innovative information security policy design. In the design of multi-terminal collaboration software, we emphasize the importance of seamless collaboration, optimizing user experience, and solving potential security challenges in a multi-terminal environment. The design of the cross-platform cloud system details its architecture, functionality, and integration mechanisms, emphasizing compatibility across operating systems and devices to promote interoperability and accessibility. The new information security strategy is designed to focus on the unique challenges of multi-terminal collaboration software, using advanced encryption methods, access control, and universal authentication protocols to strengthen the security of the system, with a special focus on ensuring data integrity and availability. Experimental results show that the proposed model and algorithm exhibit excellent performance and effects in practical applications. Research results show that through reasonable multi-terminal collaboration software design and effective information security strategies, the security and efficiency of cross-platform multi-terminal collaboration software can be significantly improved. This article provides strong theoretical support and technical solutions for the development of more secure and efficient cross-platform multi-terminal collaboration software.
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•Mackinawite (FeS) activation of persulfate achieved efficiently degradation with the initial pH ranging from 3.0 to 9.0.•A heterogeneous activation mechanism that surface Fe(II) ...activated PS to produce OHads and SO4−ads was proved.•OHfree and SO4−free diffusing from the surface of FeS were mainly responsible for the PCA degradation in the FeS/PS process.•S(-II) was able to regenerate Fe(II) from Fe(III) in the FeS/PS process.
Among the numerous iron-based materials for persulfate (PS) activation, mackinawite (FeS) particles have gained considerable interest as a ubiquitous natural mineral due to their high reactivity. However, the iron and sulfur co-mediated reaction mechanism of PS activation by FeS remains ambiguous. In this study, FeS was applied as a catalyst to activate PS for p-chloroaniline (PCA) degradation and mineralization over a wide initial pH range (3.0–11.0). The reaction was found to follow pseudo-first-order kinetics, with rate constants ranging from 0.0044 to 0.0144min−1. The reaction mechanism was elucidated by electron spin resonance (ESR) and quenching studies. A heterogeneous activation mechanism, in which surface Fe(II) species activated PS to produce OHads and SO4−ads, controlled by surface reaction and diffusion was proposed, whereas OHfree and SO4−free diffusing from the FeS surface were mainly responsible for PCA degradation. The sulfur-mediated cycling of iron species was investigated by comparing PS activation by zero-valent iron (ZVI) and FeS, exogenous Fe(III) addition and X-ray photoelectron spectroscopy (XPS). The results suggested that Fe(II) and S(-II) experienced independent oxidations and that S(-II) species could regenerate Fe(II) from Fe(III) at the FeS surface. Therefore, the S(-II)-promoted Fe(II)/Fe(III) cycle resulted in less PS decomposition but a higher PCA mineralization efficiency. The findings of this study elucidated the novel surface activation mechanism of PS by FeS and provided useful information for utilizing FeS to remediate contaminated water.
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