Transition metal (TM)‐based bimetallic spinel oxides can efficiently activate peroxymonosulfate (PMS) presumably attributed to enhanced electron transfer between TMs, but the existing model cannot ...fully explain the efficient TM redox cycling. Here, we discover a critical role of TM−O covalency in governing the intrinsic catalytic activity of Co3−xMnxO4 spinel oxides. Experimental and theoretical analysis reveals that the Co sites significantly raises the Mn valence and enlarges Mn−O covalency in octahedral configuration, thereby lowering the charge transfer energy to favor MnOh–PMS interaction. With appropriate MnIV/MnIII ratio to balance PMS adsorption and MnIV reduction, the Co1.1Mn1.9O4 exhibits remarkable catalytic activities for PMS activation and pollutant degradation, outperforming all the reported TM spinel oxides. The improved understandings on the origins of spinel oxides activity for PMS activation may inspire the development of more active and robust metal oxide catalysts.
The Mn−O covalency was enlarged by the Co sites mainly in the octahedral configuration, which results in a decreased charge transfer energy to favor Mn–PMS interaction and enhance MnIV reduction to boost PMS activation activity of Co‐Mn spinel oxides.
Dysbiosis, departure of the gut microbiome from a healthy state, has been suggested to be a powerful biomarker of disease incidence and progression
. Diagnostic applications have been proposed for ...inflammatory bowel disease diagnosis and prognosis
, colorectal cancer prescreening
and therapeutic choices in melanoma
. Noninvasive sampling could facilitate large-scale public health applications, including early diagnosis and risk assessment in metabolic
and cardiovascular diseases
. To understand the generalizability of microbiota-based diagnostic models of metabolic disease, we characterized the gut microbiota of 7,009 individuals from 14 districts within 1 province in China. Among phenotypes, host location showed the strongest associations with microbiota variations. Microbiota-based metabolic disease models developed in one location failed when used elsewhere, suggesting that such models cannot be extrapolated. Interpolated models performed much better, especially in diseases with obvious microbiota-related characteristics. Interpolation efficiency decreased as geographic scale increased, indicating a need to build localized baseline and disease models to predict metabolic risks.
Chlorine disinfection to drinking water plays an important role in preventing and controlling waterborne disease outbreaks globally. Nevertheless, little is known about why it enriches the antibiotic ...resistance genes (ARGs) in bacteria after chlorination. Here, ARGs released from killed antibiotic-resistant bacteria (ARB), and culturable chlorine-injured bacteria produced in the chlorination process as the recipient, were investigated to determine their contribution to the horizontal transfer of ARGs during disinfection treatment. We discovered Escherichia coli, Salmonella aberdeen, Pseudomonas aeruginosa and Enterococcus faecalis showed diverse resistance to sodium hypochlorite, and transferable RP4 could be released from killed sensitive donor consistently. Meanwhile, the survival of chlorine-tolerant injured bacteria with enhanced cell membrane permeabilisation and a strong oxidative stress-response demonstrated that a physiologically competent cell could be transferred by RP4 with an improved transformation frequency of up to 550 times compared with the corresponding untreated bacteria. Furthermore, the water quality factors involving chemical oxygen demand (COD
), ammonium nitrogen and metal ions (Ca
and K
) could significantly promote above transformation frequency of released RP4 into injured E. faecalis. Our findings demonstrated that the chlorination process promoted the horizontal transfer of plasmids by natural transformation, which resulted in the exchange of ARGs across bacterial genera and the emergence of new ARB, as well as the transfer of chlorine-injured opportunistic pathogen from non-ARB to ARB. Considering that the transfer elements were quite resistant to degradation through disinfection, this situation poses a potential risk to public health.
Studies of Late Quaternary geological slip-rates and the GPS decadal slip-rates along the major strike-slip faults in the northern margin of the Tibetan Plateau show that slip-rates remain relatively ...constant along the middle sections of each fault and decrease rapidly toward the ends. Our recent studies suggest that the slip rates are low (<10mm/yr) along the major strike-slip faults, i.e., Altyn-Tagh fault and Qilian-Haiyuan fault. West of 95°E, the slip rate on the Altyn-Tagh fault has been determined to be 8–12mm/yr, and gradually decreases from 95°E eastward to about 1–2mm/yr at the easternmost segment of the fault. The slip-rate of Qilian-Haiyuan fault is about 1–2mm/yr near the Halahu Lake, near the western tip of the fault, then increases to a relatively constant value of 4–5mm/yr in the Qilian area (101°E and eastward). Eastward, the fault merges into the NS trending Liupan Shan fault zone east of Haiyuan, and the slip rate drops to 1–3mm/yr, or even lower. Our present observations on the variation and distribution of slip rates along the major strike slip faults indicate that slip on the Altyn-Tagh fault is mainly dissipated through internal deformation, by thrust faulting within the Qilian Shan and shortening within the adjacent Cenozoic basins. Left-lateral strike-slip on the Qilian-Haiyuan fault might be transformed into shortening and growth of the Liupan Shan to the east, and may also contribute partially to the deformation in the western Qilian Shan. In conclusion, the distribution of slip rates from both late Quaternary geological records and the current GPS observations suggest a decrease in slip rate, a redistribution of strain, and the transformation of displacement along the major strike slip faults into crustal shortening, basin formation and mountain uplift that characterize present-day deformation of the northern margin of the Tibetan Plateau.
►Slip rates of faults are jointly determined by geological and geodetic methods. ►Boundary faults of northern Tibet slip at very low rate of less than 10mm/a. ►Sharp tapers of slip rate are found at the ends of these boundary faults. ►Slips on boundary faults are dissipated by thrust faulting and basin shortening. ►Present-day deformation of north Tibet margin is featured by this dissipation.
Background
High incidence of asymptomatic venous thromboembolism (VTE) has been observed in severe COVID‐19 patients, but the characteristics of symptomatic VTE in general COVID‐19 patients have not ...been described.
Objectives
To comprehensively explore the prevalence and reliable risk prediction for VTE in COVID‐19 patients.
Methods/Results
This retrospective study enrolled all COVID‐19 patients with a subsequent VTE in 16 centers in China from January 1 to March 31, 2020. A total of 2779 patients were confirmed with COVID‐19. In comparison to 23,434 non‐COVID‐19 medical inpatients, the odds ratios (ORs) for developing symptomatic VTE in severe and non‐severe hospitalized COVID‐19 patients were 5.94 (95% confidence interval CI 3.91–10.09) and 2.79 (95% CI 1.43–5.60), respectively. When 104 VTE cases and 208 non‐VTE cases were compared, pulmonary embolism cases had a higher rate for in‐hospital death (OR 6.74, 95% CI 2.18–20.81). VTE developed at a median of 21 days (interquartile range 13.25–31) since onset. Independent factors for VTE were advancing age, cancer, longer interval from symptom onset to admission, lower fibrinogen and higher D‐dimer on admission, and D‐dimer increment (DI) ≥1.5‐fold; of these, DI ≥1.5‐fold had the most significant association (OR 14.18, 95% CI 6.25–32.18, p = 2.23 × 10−10). A novel model consisting of three simple coagulation variables (fibrinogen and D‐dimer levels on admission, and DI ≥1.5‐fold) showed good prediction for symptomatic VTE (area under the curve 0.865, 95% CI 0.822–0.907, sensitivity 0.930, specificity 0.710).
Conclusions
There is an excess risk of VTE in hospitalized COVID‐19 patients. This novel model can aid early identification of patients who are at high risk for VTE.
•Review covers current state-of-the-art of PAA-based AOPs.•Various methods of PAA activation as well as their activation mechanisms are summarized.•PAA-based AOPs hold great promise for applications ...in contaminant degradation.•UV/PAA is the most promising technology for water disinfection among PAA-based AOPs.•Existing problems, challenges and solutions for research in PAA-based AOPs are discussed.
Peracetic acid (PAA) has attracted growing attention as an alternative oxidant and disinfectant in wastewater treatment due to the increased demand to reduce chlorine usage and control disinfection byproducts (DBPs). These applications have stimulated new investigations on PAA-based advanced oxidation processes (AOPs), which can enhance water disinfection and remove micropollutants. The purpose of this review is to conduct a comprehensive analysis of scientific information and experimental data reported in recent years on the applications of PAA-based AOPs for the removal of chemical and microbiological micropollutants from water and wastewater. Various methods of PAA activation, including the supply of external energy and metal/metal-free catalysts, as well as their activation mechanisms are discussed. Then, a review on the usage of PAA-based AOPs for contaminant degradation is given. The degradation mechanisms of organic compounds and the influence of the controlling parameters of PAA-based treatment systems are summarized and discussed. Concurrently, the application of PAA-based AOPs for water disinfection and the related mechanisms of microorganism inactivation are also reviewed. Since combining UV light with PAA is the most commonly investigated PAA-based AOP for simultaneous pathogen inactivation and micropollutant oxidation, we have also focused on PAA microbial inactivation kinetics, together with the effects of key experimental parameters on the process. Moreover, we have discussed the advantages and disadvantages of UV/PAA as an AOP against the well-known and established UV/H2O2. Finally, the knowledge gaps, challenges, and new opportunities for research in this field are discussed. This critical review will facilitate an in-depth understanding of the PAA-based AOPs for water and wastewater treatment and provide useful perspectives for future research and development for PAA-based technologies.
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Abstract
Discovery of pulsars is one of the main goals for large radio telescopes. The Five-hundred-meter Aperture Spherical radio Telescope (FAST), that incorporates an L-band 19-beam receiver with ...a system temperature of about 20 K, is the most sensitive radio telescope utilized for discovering pulsars. We designed the
snapshot
observation mode for a FAST key science project, the Galactic Plane Pulsar Snapshot (GPPS) survey, in which every four nearby pointings can observe
a cover
of a sky patch of 0.1575 square degrees through beam-switching of the L-band 19-beam receiver. The integration time for each pointing is 300 seconds so that the GPPS observations for a cover can be made in 21 minutes. The goal of the GPPS survey is to discover pulsars within the Galactic latitude of ± 10° from the Galactic plane, and the highest priority is given to the inner Galaxy within ± 5°. Up to now, the GPPS survey has discovered 201 pulsars, including currently the faintest pulsars which cannot be detected by other telescopes, pulsars with extremely high dispersion measures (DMs) which challenge the currently widely used models for the Galactic electron density distribution, pulsars coincident with supernova remnants, 40 millisecond pulsars, 16 binary pulsars, some nulling and mode-changing pulsars and rotating radio transients (RRATs). The follow-up observations for confirmation of new pulsars have polarization-signals recorded for polarization profiles of the pulsars. Re-detection of previously known pulsars in the survey data also leads to significant improvements in parameters for 64 pulsars. The GPPS survey discoveries are published and will be updated at
http://zmtt.bao.ac.cn/GPPS/
.
Nonradical Fenton-like catalysis offers opportunities to overcome the low efficiency and secondary pollution limitations of existing advanced oxidation decontamination technologies, but realizing ...this on transition metal spinel oxide catalysts remains challenging due to insufficient understanding of their catalytic mechanisms. Here, we explore the origins of catalytic selectivity of Fe-Mn spinel oxide and identify electron delocalization of the surface metal active site as the key driver of its nonradical catalysis. Through fine-tuning the crystal geometry to trigger Fe-Mn superexchange interaction at the spinel octahedra, ZnFeMnO
with high-degree electron delocalization of the Mn-O unit was created to enable near 100% nonradical activation of peroxymonosulfate (PMS) at unprecedented utilization efficiency. The resulting surface-bound PMS* complex can efficiently oxidize electron-rich pollutants with extraordinary degradation activity, selectivity, and good environmental robustness to favor water decontamination applications. Our work provides a molecule-level understanding of the catalytic selectivity and bimetallic interactions of Fe-Mn spinel oxides, which may guide the design of low-cost spinel oxides for more selective and efficient decontamination applications.
As one kind of Burgers-type equation, the extended coupled (2+1)-dimensional Burgers system is used to describe certain wave process in oceanography, acoustics or hydrodynamics. With the Riccati ...projective equation method and symbolic computation, the variable separation solution is derived. Due to the arbitrary functions in the variable separation solutions, the fractal and chaotic structures are studied based on the gradient function (say,
U
in the text). Some excitation properties of the solutions are analyzed and figures are plotted to show the shape and the structure.
Background Chronic spontaneous urticaria (CSU) is defined by itchy hives, angioedema, or both for at least 6 weeks. Omalizumab, an anti-IgE antibody that affects mast cell and basophil function, is a ...promising new treatment option. As of now, however, the efficacy and safety of different doses of omalizumab used in clinical trials for CSU have not been systematically analyzed and summarized. Objective We sought to assess the efficacy and safety of different doses of omalizumab for the treatment of CSU in a meta-analysis of clinical trial results. Methods Suitable trials were identified by searching PubMed, Medline, Embase, and Web of Science databases and with the help of omalizumab's manufacturers. Only double-blind, randomized, placebo-controlled studies with omalizumab-treated versus placebo-treated patients with CSU were included in this analysis. Results We identified 7 randomized, placebo-controlled studies with 1312 patients with CSU. Patients treated with omalizumab (75-600 mg every 4 weeks) had significantly reduced weekly itch and weekly wheal scores compared with the placebo group. Omalizumab's effects were dose dependent, with the strongest reduction in weekly itch and weekly wheal scores observed with 300 mg. Rates of complete response were significantly higher in the omalizumab group (relative risk, 4.55; P < .00001) and dose dependent, with the highest rates in the 300-mg group. Rates of patients with adverse events were similar in the omalizumab and placebo groups. Conclusion This meta-analysis provides high-quality evidence for the efficacy and safety of omalizumab in patients with CSU and for treating these patients with 300 mg of omalizumab every 4 weeks.
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