Green Approach for Simultaneous Quantitative Analysis of Fluoroquinolones in the Environment using Three-Dimensional Fluorescence Coupled with Second-Order Calibration Method.

In this study, a straightforward and quick analytical technique based on the self-weighted alternating trilinear decomposition (SWATLD) algorithm in conjunction with excitation-emission matrix (EEM) fluorescence for the simultaneous determination of the antibiotics levofloxacin (LVFX) and ciprofloxacin (CIP) in environmental waters and sediments was developed. This approach completely utilizes the "second-order advantage" and inherits the great sensitivity of classic fluorescence. It replaces or improves the conventional "physical/chemical separation" with "mathematical separation", enabling direct and quick quantification of the target analytes even in the presence of unknown interferences, greatly streamlining sample preparation procedures, consuming less solvent, and speeding up analysis time, and allows successful and environmentally friendly solution of overlapping fluorescence spectra of multiple components in complicated environmental matrices without cumbersome pretreatment steps and complex and expensive instrumentation. The limits of detection varied between 0.34 and 0.67 ng mL- 1, and the average spiking recoveries of LVFX and CIP in water and sediment ranged from 97.6 to 107.7% with relative standard deviations lower than 6.6%. The developed method shows the reliability of the technology and the ability to quickly detect trace antibiotics in lake water even in the presence of unidentified interferents.

Different effects of seasonal impoundment and land use change on microbiome in a tributary sediment of the three gorgers reservoir.

Anthropogenic activities significantly impact river ecosystem nutrient fluxes and microbial metabolism. Here, we examined the seasonal and spatial variation of sediments physicochemical parameters and the associated microbiome in the Pengxi river, a representative tributary of Three Gorges Reservoir, in response to seasonal impoundment and land use change by human activities. Results revealed that seasonal impoundment and land use change enhanced total organic carbon (TOC), total nitrogen (TN) and ammonium nitrogen (NH4+-N) concentration in the sediment, but have different effects on sediment microbiome. Sediment microbiota showed higher similarity during the seasonal high-water level (HWL) in consecutive two years. The abundant phyla Acidobacteria, Gemmatimonadetes, Cyanobacteria, Actinobacteria and Planctomycetes significantly increased as water level increased. Along the changes in bacterial taxa, we also observed changes in predicted carbon fixation functions and nitrogen-related functions, including the significantly higher levels of Calvin cycle, 4HB/3HP cycle, 3HP cycle and assimilatory nitrate reduction, while significantly lower level of denitrification. Though land use change significantly increased TOC, TN and NH4+-N concentration, its effects on spatial variation of bacterial community composition and predicted functions was not significant. The finding indicates that TGR hydrologic changes and land use change have different influences on the carbon and nitrogen fluxes and their associated microbiome in TGR sediments. A focus of future research will be on assessing on carbon and nitrogen flux balance and the associated carbon and nitrogen microbial cycling in TGR sediment.

Viral community distribution, assembly mechanism, and associated hosts in an industrial park wastewater treatment plant.

Viruses manipulate bacterial community composition and impact wastewater treatment efficiency. Some viruses pose threats to the environment and human populations through infection. Improving the efficiency of wastewater treatment and ensuring the health of the effluent and receptor pools requires an understanding of how viral communities assemble and interact with hosts in wastewater treatment plants (WWTPs). We used metagenomic analysis to study the distribution, assembly mechanism, and sensitive hosts for the viral communities in raw water, anaerobic tanks, and returned activated sludge units of a large-scale industrial park WWTP. Uroviricota (53.42% ± 0.14%) and Nucleocytoviricota (26.1% ± 0.19%) were dominant in all units. Viral community composition significantly differed between units, as measured by ß diversity (P = 0.005). Compared to raw water, the relative viral abundance decreased by 29.8% in the anaerobic tank but increased by 9.9% in the activated sludge. Viral community assembly in raw water and anaerobic tanks was predominantly driven by deterministic processes (MST <0.5) versus stochastic processes (MST >0.5) in the activated sludge, indicating that differences in diffusion limits may fundamentally alter the assembly mechanisms of viral communities between the solid and liquid-phase environments. Acidobacteria was identified as the sensitive host contributing to viral abundance, exhibiting strong interactions and a mutual dependence (degree = 59). These results demonstrate the occurrence and prevalence of viruses in WWTPs, their different assembly mechanism, and sensitive hosts. These observations require further study of the mechanisms of viral community succession, ecological function, and roles in the successive wastewater treatment units.

Recent advance of microbial mercury methylation in the environment.

Methylmercury formation is mainly driven by microbial-mediated process. The mechanism of microbial mercury methylation has become a crucial research topic for understanding methylation in the environment. Pioneering studies of microbial mercury methylation are focusing on functional strain isolation, microbial community composition characterization, and mechanism elucidation in various environments. Therefore, the functional genes of microbial mercury methylation, global isolations of Hg methylation strains, and their methylation potential were systematically analyzed, and methylators in typical environments were extensively reviewed. The main drivers (key physicochemical factors and microbiota) of microbial mercury methylation were summarized and discussed. Though significant progress on the mechanism of the Hg microbial methylation has been explored in recent decade, it is still limited in several aspects, including (1) molecular biology techniques for identifying methylators; (2) characterization methods for mercury methylation potential; and (3) complex environmental properties (environmental factors, complex communities, etc.). Accordingly, strategies for studying the Hg microbial methylation mechanism were proposed. These strategies include the following: (1) the development of new molecular biology methods to characterize methylation potential; (2) treating the environment as a micro-ecosystem and studying them from a holistic perspective to clearly understand mercury methylation; (3) a more reasonable and sensitive inhibition test needs to be considered. KEY POINTS: • Global Hg microbial methylation is phylogenetically and functionally discussed. • The main drivers of microbial methylation are compared in various condition. • Future study of Hg microbial methylation is proposed.

Green Synthesis and Antifungal Activities of Novel N-Aryl Carbamate Derivatives.

Carbamate is a key structural motif in the development of fungicidal compounds, which is still promising and robust in the discovery of green pesticides. Herein, we report the synthesis and evaluation of the fungicidal activity of 35 carbamate derivatives, among which 19 compounds were synthesized in our previous report. These derivatives were synthesized from aromatic amides in a single step, which was a green oxidation process for Hofmann rearrangement using oxone, KCl and NaOH. Their chemical structures were characterized by 1H NMR, 13C NMR and high-resolution mass spectrometry. Their antifungal activity was tested against seven plant fungal pathogens. Many of the compounds exhibited good antifungal activity in vitro (inhibitory rate > 60% at 50 µg/mL). Compound 1ag exhibited excellent broad-spectrum antifungal activities with inhibition rates close to or higher than 70% at 50 µg/mL. Notably, compound 1af demonstrated the most potent inhibition against F. graminearum, with an EC50 value of 12.50 µg/mL, while compound 1z was the most promising candidate fungicide against F. oxysporum (EC50 = 16.65 µg/mL). The structure-activity relationships are also discussed in this paper. These results suggest that the N-aryl carbamate derivatives secured by our green protocol warrant further investigation as potential lead compounds for novel antifungal agents.

Ecofriendly Protocol for ipso-Bromination of Arylboronic Acids.

We report a novel and environmentally friendly method for the ipso-bromination of arylboronic acids by exploiting the oxone/KBr system. We discovered that CuBr can catalyze the reaction and increase the yield from 63 to 97%. We believe that CuBr might catalyze the in situ generation of HOBr from oxone/KBr. The mild reaction condition permits tolerance of a diverse array of functional groups with exclusive regio- and chemoselectivity and allows low-cost large-scale reaction without explosion risk.

Correlation between obstructive sleep apnea and hypoperfusion in patients with acute cerebral infarction.

Purpose: To explore the relationship between obstructive sleep apnea (OSA) and hypoperfusion during ultra-early acute cerebral infarction. Patients and methods: Data were retrospectively collected from patients admitted to our hospital with acute cerebral infarction between January 2020 and January 2022, who underwent comprehensive whole-brain computed tomography perfusion imaging and angiography examinations within 6 h of onset. The F-stroke software automatically assessed and obtained relevant data (Tmax). The patients underwent an initial screening for sleep apnea. Based on their Apnea-Hypopnea Index (AHI), patients were categorized into an AHI ≤15 (n = 22) or AHI >15 (n = 25) group. The pairwise difference of the time-to-maximum of the residue function (Tmax) > 6 s volume was compared, and the correlation between AHI, mean pulse oxygen saturation (SpO2), oxygen desaturation index (ODI), percentage of time with oxygen saturation < 90% (T90%), and the Tmax >6 s volume was analyzed. Results: The Tmax >6 s volume in the AHI > 15 group was significantly larger than that in the AHI ≤ 15 group [109 (62-157) vs. 59 (21-106) mL, p = 0.013]. Spearman's correlation analysis revealed Tmax >6 s volume was significantly correlated with AHI, mean SpO2, ODI, and T90% in the AHI > 15 group, however, no significant correlations were observed in the AHI ≤ 15 group. Controlling for the site of occlusion and Multiphase CT angiography (mCTA) score, AHI (ß = 0.919, p < 0.001), mean SpO2 (ß = -0.460, p = 0.031), ODI (ß = 0.467, p = 0.032), and T90% (ß =0.478, p = 0.026) remained associated with early hypoperfusion in the AHI > 15 group. Conclusion: In patients with acute cerebral infarction and AHI > 15, AHI, mean SpO2, ODI and T90% were associated with early hypoperfusion. However, no such relationship exists among patients with AHI ≤ 15.

Formation of Sb2O3 microcrystals by Rhodotorula mucilaginosa.

Antimony (Sb) pollution seriously endangers ecological environment and human health. Microbial induced mineralization can effectively convert metal ions into more stable and less soluble crystalline minerals by extracellular polymeric substance (EPS). In this study, an efficient Sb-resistant Rhodotorula mucilaginosa (R. mucilaginosa) was screened, which can resist 41 mM Sb(III) and directly transform Sb(III) into Sb2O3 microcrystals by EPS. The removal efficiency of R. mucilaginosa for 22 mM Sb(III) reached 70% by converting Sb(III) to Sb2O3. The components of supernatants as well as the effects of supernatants and pH on Sb(III) mineralization verified that inducible and non-inducible extracellular protein/polysaccharide biomacromolecules play important roles in the morphologies and sizes control of Sb2O3 formed by R. mucilaginosa respectively. Sb2O3 microcrystals with different morphologies and sizes can be prepared by the regulation of inducible and non-inducible extracellular biomacromolecules secreted by R. mucilaginosa. This is the first time to identify that R. mucilaginosa can remove Sb(III) by transforming Sb(III) into Sb2O3 microcrystals under the control of EPS. This study contributes to our understanding for Sb(III) biomineralization mechanisms and provides strategies for the remediation of Sb-contaminated environment.

Sterile Diet Causes Gut Microbiome Collapse of Cancer Patients Post Hematopoietic Cell Transplantation, But Normal Diet Recovers Them.

Though sterile diet, post-transplantation surgery is a clinical strategy for patient care to prevent the infiltration of gut pathogens, less is known about its effects on the gut microbiome. Here, the gut microbiome dynamics of leukemia patients following a 120-day "sterile-normal" diet strategy posthematopoietic cell transplantation are examined. In contrast to the traditional idea, a sterile diet leads to the lowest gut microbiota diversity (p < 0.05) and short-chain fatty acids, promoted the proliferation of potential pathogens such as Streptococcus (up by 16.93%) and Lactobacillus (up by 40.30%), and 43.32% reduction in nodes and an 85.33% reduction in edges within the microbial interaction's network. Interestingly, a normal diet allows the gut microbiome recovery and significantly promotes the abundance of beneficial bacteria. These results indicate that a sterile diet leads to a collapse of the patient's gut microbiome and promoted the proliferation of potential pathogens. This assay is a starting point for a more sophisticated assessment of the effects of a sterile diet. The work also suggests a basic principle for the re-establishment of microbial equilibrium that supplementation of microbial taxa may be the key to the restoration of the degraded ecosystem.