Nitrogen doped carbon quantum dots mediated silver phosphate/bismuth vanadate Z-scheme photocatalyst for enhanced antibiotic degradation

A novel nitrogen doped carbon quantum dots (N-CQDs) mediated Ag3PO4/BiVO4 Z-scheme photocatalyst was synthesized through a solvothermal-precipitation method. The as-prepared photocatalysts were comprehensive characterized by X-ray diffraction, X-ray photo-electron spectroscopy, scanning electron microscopy, transmission electron micrograph, UV-vis diffuse reflection spectroscopy, vis photoluminescence and electron spin resonance analysis. The photocatalytic performances of as-prepared photocatalysts were used for degradation of tetracycline (TC) under visible-light illumination. Results exhibited the increased photocatalytic efficiency of BiVO4/N-CQDs/Ag3PO4-10 (Ag3PO4 with the mass ratio of BiVO4/N-CQDs/Ag3PO4 = 10%) to photodegrade TC is up to 88.9% in 30 min and 59.8% mineralization in 90 min. The degradation reaction coefficient (k) is about 6.00, 2.78 and 1.80 times higher than that of BiVO4, N-CQDs/BiVO4 and Ag3PO4/BiVO4, respectively. The excellent photocatalytic performance of the Z-scheme BiVO4/N-CQDs/Ag3PO4 was attributed to the construction of Z-scheme system, increased light harvesting capacity and improved molecular oxygen activation ability. Moreover, the photocatalytic activity of BiVO4/N-CQDs/Ag3PO4 remained 79.9% after five cycling runs, indicating the high stability and reusability of the as-prepared photocatalyst. Additionally, a possible photocatalytic mechanism of the novel Z-scheme BiVO4/N-CQDs/Ag3PO4 was proposed

Use of bacteria for improving the lignocellulose biorefinery process: importance of pre-erosion

Abstract Background Biological pretreatment is an important alternative strategy for biorefining lignocellulose and has attracted increasing attention in recent years. However, current designs for this pretreatment mainly focus on using various white rot fungi, overlooking the bacteria. To the best of our knowledge, for the first time, we evaluated the potential contribution of bacteria to lignocellulose pretreatment, with and without a physicochemical process, based on the bacterial strain Pandoraea sp. B-6 (hereafter B-6) that was isolated from erosive bamboo slips. Moreover, the mechanism of the improvement of reducing sugar yield by bacteria was elucidated via analyses of the physicochemical changes of corn stover (CS) before and after pretreatment. Results The digestibility of CS pretreated with B-6 was equivalent to that of untreated CS. The recalcitrant CS surface provided fewer mediators for contact with the extracellular enzymes of B-6. A pre-erosion strategy using a tetrahydrofuran–water co-solvent system was shown to destroy the recalcitrant CS surface. The optimal condition for pre-erosion showed a 6.5-fold increase in enzymatic digestibility compared with untreated CS. The pre-erosion of CS can expose more phenolic compounds that were chelated to oxidized Mn3+ and also provided mediators for combination with laccase, which was attributable to B-6 pretreatment. B-6 pretreatment following pre-erosion exhibited a sugar yield that was 91.2 mg/g greater than that of pre-erosion alone and 7.5-fold higher than that of untreated CS. This pre-erosion application was able to destroy the recalcitrant CS surface, thus leading to a rough and porous architecture that better facilitated the diffusion and transport of lignin derivatives. This enhanced the ability of laccase and manganese peroxidase secreted by B-6 to improve the efficiency of this biological pretreatment. Conclusion Bacteria were not found useful alone as a biological pretreatment, but they significantly improved enzymatic digestion after lignocellulose breakdown via other physicochemical methods. Nonetheless, phenyl or phenoxy radicals were used by laccase and manganese peroxidase in B-6 for lignin attack or lignin depolymerization. These particular mediators released from the recalcitrance network of lignocellulose openings are important for the efficacy of this bacterial pretreatment. Our findings thus offer a novel perspective on the effective design of biological pretreatment methods for lignocellulose

Multiple charge separation pathways in photosystem II: modeling of transient absorption kinetics.

Additional file 1: Figure S1. The effects of pretreatment conditions on the enzymatic hydrolysis of the untreated (dashed line) and pretreated RS. The experimental groups were A: 0.04 M FeCl3/0.04 M FeCl2/3 M H2O2; B: 0.03 M FeCl3/0.03 M FeCl2/2.25 M H2O2; C: 0.02 M FeCl3/0.02 M FeCl2/1.5 M H2O2; D: 0.01 M FeCl3/0.01 M FeCl2/0.75 M H2O2

H3K27me3 of Rnf19a promotes neuroinflammatory response during Japanese encephalitis virus infection

Abstract Histone methylation is an important epigenetic modification that affects various biological processes, including the inflammatory response. In this study, we found that infection with Japanese encephalitis virus (JEV) leads to an increase in H3K27me3 in BV2 microglial cell line, primary mouse microglia and mouse brain. Inhibition of H3K27me3 modification through EZH2 knockdown and treatment with EZH2 inhibitor significantly reduces the production of pro-inflammatory cytokines during JEV infection, which suggests that H3K27me3 modification plays a crucial role in the neuroinflammatory response caused by JEV infection. The chromatin immunoprecipitation-sequencing (ChIP-sequencing) assay revealed an increase in H3K27me3 modification of E3 ubiquitin ligases Rnf19a following JEV infection, which leads to downregulation of Rnf19a expression. Furthermore, the results showed that Rnf19a negatively regulates the neuroinflammatory response induced by JEV. This is achieved through the degradation of RIG-I by mediating its ubiquitination. In conclusion, our findings reveal a novel mechanism by which JEV triggers extensive neuroinflammation from an epigenetic perspective

Dissimilatory and Cytoplasmic Antimonate Reductions in a Hydrogen-Based Membrane Biofilm Reactor

A hydrogen-based membrane biofilm reactor (H2-MBfR) was operated to investigate the bioreduction of antimonate [Sb(V)] in terms of Sb(V) removal, the fate of Sb, and the pathways of reduction metabolism. The MBfR achieved up to 80% Sb(V) removal and an Sb(V) removal flux of 0.55 g/m2·day. Sb(V) was reduced to Sb(III), which mainly formed Sb2O3 precipitates in the biofilm matrix, although some Sb(III) was retained intracellularly. High Sb(V) loading caused stress that deteriorated performance that was not recovered when the high Sb(V) loading was removed. The biofilm community consisted of DSbRB (dissimilatory Sb-reduction bacteria), SbRB (Sb-resistant bacteria), and DIRB (dissimilatory iron-reducing bacteria). Dissimilatory antimonate reduction, mediated by the respiratory arsenate reductase ArrAB, was the main reduction route, but respiratory reduction coexisted with cytoplasmic Sb(V)-reduction mediated by arsenate reductase ArsC. Increasing Sb(V) loading caused stress that led to increases in the expression of arsC gene and intracellular accumulation of Sb(III). By illuminating the roles of the dissimilatory and cytoplasmic Sb(V) reduction mechanism in the biofilms of the H2-MBfR, this study reveals that the Sb(V) loading should be controlled to avoid stress that deteriorates Sb(V) reduction

Ambient particulate matter pollution and adult hospital admissions for pneumonia in urban China: A national time series analysis for 2014 through 2017.

BACKGROUND:The effects of ambient particulate matter (PM) pollution on pneumonia in adults are inconclusive, and few scientific data on a national scale have been generated in low- or middle-income countries, despite their much higher PM concentrations. We aimed to examine the association between PM levels and hospital admissions for pneumonia in Chinese adults. METHODS AND FINDINGS:A nationwide time series study was conducted in China between 2014 and 2017. Information on daily hospital admissions for pneumonia for 2014-2017 was collected from the database of Urban Employee Basic Medical Insurance (UEBMI), which covers 282.93 million adults. Associations of PM concentrations and hospital admissions for pneumonia were estimated for each city using a quasi-Poisson regression model controlling for time trend, temperature, relative humidity, day of the week, and public holiday and then pooled by random-effects meta-analysis. Meta-regression models were used to investigate potential effect modifiers, including cities' annual-average air pollutants concentrations, temperature, relative humidity, gross domestic product (GDP) per capita, and coverage rates by the UEBMI. More than 4.2 million pneumonia admissions were identified in 184 Chinese cities during the study period. Short-term elevations in PM concentrations were associated with increased pneumonia admissions. At the national level, a 10-μg/m3 increase in 3-day moving average (lag 0-2) concentrations of PM2.5 (PM ≤2.5 μm in aerodynamic diameter) and PM10 (PM ≤10 μm in aerodynamic diameter) was associated with 0.31% (95% confidence interval [CI] 0.15%-0.46%, P < 0.001) and 0.19% (0.11%-0.30%, P < 0.001) increases in hospital admissions for pneumonia, respectively. The effects of PM10 were stronger in cities with higher temperatures (percentage increase, 0.031%; 95% CI 0.003%-0.058%; P = 0.026) and relative humidity (percentage increase, 0.011%; 95% CI 0%-0.022%; P = 0.045), as well as in the elderly (percentage increase, 0.10% [95% CI 0.02%-0.19%] for people aged 18-64 years versus 0.32% [95% CI 0.22%-0.39%] for people aged ≥75 years; P < 0.001). The main limitation of the present study was the unavailability of data on individual exposure to PM pollution. CONCLUSIONS:Our findings suggest that there are significant short-term associations between ambient PM levels and increased hospital admissions for pneumonia in Chinese adults. These findings support the rationale that further limiting PM concentrations in China may be an effective strategy to reduce pneumonia-related hospital admissions

Elucidating the Interactive Impacts of Substrate-Related Properties on Lignocellulosic Biomass Digestibility: A Sequential Analysis

A lack of insight into interactive effects among substrate-related factors holds back the determination of dominant factors in efficient sugar conversion. Herein, 13 factors defining compositional and physicochemical properties of lignocellulose pretreated by dilute acid/base and enzymes were analyzed through an innovative sequence of correlation analysis, principle component analysis, multiple linear regression, and multiscale statistical validation. Results showed that the lignin content, cellulose content, and O/C ratio principally affected enzymatic hydrolysis. The dominant role was played by the lignin content due to its major recalcitrance providing to biomass and concomitant impacts on surface lignin and porosity properties. The structural features of lignin played a less pronounced role with high lignin content that remained. Besides, the sequential analysis revealed different inhibition mechanisms for glucan and carbohydrate conversion, that is, nonproductive binding of enzymes and steric hindrance of lignin, respectively. The established weighing order of interactive factors enlightened more efficient pretreatment strategies

In Situ Lignin Bioconversion Promotes Complete Carbohydrate Conversion of Rice Straw by <i>Cupriavidus basilensis</i> B‑8

The valorization of lignocellulose encounters both opportunities and challenges as the lignocellulose is an abundant and intrinsically heterogeneous natural source. However, the successful design of an integrated process for complete carbon utilization of lignocellulose is limited. A classic base-catalyzed pretreatment strategy and a natural <i>Cupriavidus</i> strain with the capacity of lignin degradation and polyhydroxyalkanoates (PHAs) biosynthesis were selected to establish a fundamental and functional module necessary to enable a new platform for lignocellulose pretreatment and waste carbon conversion. The in situ bioconversion was first introduced to the pretreatment. Specifically, selectively cleaving insensitive C–C bonds (e.g., β-5) of lignin via a “washing” mechanism, <i>Cupriavidus basilensis</i> B-8 promoted the digestibility of the rice straw to realize almost complete carbohydrate conversion, yielding 984.2 mg g^–1 of reducing sugar when combined with alkaline pretreatment. A demonstrated concentration of PHA (482.7 mg L^–1) was obtained from the conversion of the removed lignin in ligninolytic bacteria. The integrated molecular conversion mechanisms of lignin in bacteria were further elucidated. Our work provides a novel perspective for biorefinery design