Enrichment performance and salt tolerance of polyhydroxyalkanoates (PHAs) producing mixed cultures under different saline environments

The key to the resource recycling of saline wastes in form of polyhydroxyalkanoates (PHA) is to enrich mixed cultures with salt tolerance and PHA synthesis ability. However, the comparison of saline sludge from different sources and the salt tolerance mechanisms of salt-tolerant PHA producers need to be clarified. In this study, three kinds of activated sludge from different salinity environments were selected as the inoculum to enrich salt-tolerant PHA producers under aerobic dynamic feeding (ADF) mode with butyric acid dominated mixed volatile fatty acid as the substrate. The maximum PHA content (PHAm) reached 0.62 ± 0.01, 0.62 ± 0.02, and 0.55 ± 0.03 g PHA/g VSS at salinity of 0.5%, 0.8%, and 1.8%, respectively. Microbial community analysis indicated that Thauera, Paracoccus, and Prosthecobacter were dominant salt-tolerant PHA producers at low salinity, Thauera, NS9_marine, and SM1A02 were dominant salt-tolerant PHA producers at high salinity. High salinity and ADF mode had synergistic effects on selection and enrichment of salt-tolerant PHA producers. Combined correlation network with redundancy analysis indicated that trehalose synthesis genes and betaine related genes had positive correlation with PHAm, while extracellular polymeric substances (EPS) content had negative correlation with PHAm. The compatible solutes accumulation and EPS secretion were the main salt tolerance mechanisms of the PHA producers. Therefore, adding compatible solutes is an effective strategy to improve PHA synthesis in saline environment.

Effects of oxytetracycline on variation in intracellular and extracellular antibiotic resistance genes during swine manure composting

This research aimed to investigate the alterations in extracellular (eARGs) and intracellular (iARGs) antibiotic resistance genes in response to oxytetracycline (OTC), and unravel the dissemination mechanism of ARGs during composting. The findings revealed both low (L-OTC) and high contents (H-OTC) of OTC significantly enhanced absolute abundance (AA) of iARGs (p < 0.05), compared to CK (no OTC). Composting proved to be a proficient strategy for removing eARGs, while AA of eARGs was significantly enhanced in H-OTC (p < 0.05). OTC resulted in an increase in AA of mobile genetic elements (MGEs), ATP levels, antioxidant and DNA repair enzymes in bacteria in compost product. Structural equation model further demonstrated that OTC promoted bacterial DNA repair and antioxidant enzyme activities, altered bacterial community and enhanced MGEs abundance, thereby facilitating iARGs dissemination. This study highlights OTC can increase eARGs and iARGs abundance, underscoring the need for appropriate countermeasures to mitigate potential hazards.

Ecological succession and community assembly of mixed microbial culture polyhydroxyalkanoate production systems: Drivers of polyhydroxyalkanoate synthesis and Bdellovibrio predation

The production of polyhydroxyalkanoate (PHA) by mixed microbial culture (MMC) can reduce the pollution of plastics. Ecophysiological study of the microbial community assembly and succession is helpful for comprehensive understanding the MMC PHA production process. The operation mode of sequential aerobic dynamic discharge - aerobic dynamic feeding (ADD-ADF) was applied and the operation can be divided into acclimation phase and maturation phase. Deterministic process caused by selective pressure dominated the community assembly throughout the operation. In the acclimation phase, the physical selective pressure recovered the settling capacity of the system, and settling ability of the MMC was closely related to function of PHA synthesis. However, in the maturation phase, stochastic process caused sludge bulking, making the settling ability and PHA synthesis function of the MMC independent on each other. Stochastic process led to the succession of the dominant PHA-producing bacteria, for example, the predation of Paracoccus and Thauera by Bdellovibrio.

Effects of Fe/Fe-Mn oxides loaded biochar on anaerobic degradation of typical phenolic compounds in coal gasification wastewater: Performance and mechanism

In this study, two kinds of magnetic biochar (BC) were synthesized by loading Fe (FeBC) and Fe-Mn oxides (FMBC) and their effects on anaerobic phenolics degradation were investigated. Compared with BC/FMBC, FeBC addition achieved the superior phenolics biodegradation even for 3,5-xylenol. Compared with control, FeBC addition enhanced CH4 production by 100.1 % with the lag time shortened from 9.5 days to 6.6 days while it increased to 11.2 days with FMBC addition. FeBC addition activated adsorption-biodegradation and Fe (III) reduction with the improved electron transfer activity, adenosine triphosphate and cytochrome C concentrations. Abundant phenol degrading bacteria, electroactive bacteria, syntrophic partners could be enriched by FeBC addition, contributing to the enhanced benzoyl-CoA and methanogenesis pathways. However, this enhancement was inhibited by FMBC addition owing to the accumulation of reactive oxygen species. This study provided novel insights into the application of magnetic BC to enhanced anaerobic treatment of phenolic wastewater.

Size matters: Powder biochar promotes the elimination of antibiotics resistance genes and potential hosts during swine manure composting

Livestock manure faced acute environmental pollution and ecology risky caused by antibiotic resistance genes (ARGs). This study investigated the effects of biochar particle size including powder biochar (75 μm, PB), and granular biochar (2 mm, GB) on ARGs variation during the aerobic composting. The results showed that the total relative abundance (RA) of the ARGs decreased significantly in all the treatments after composting. While compared to the removal efficiency of total RA in the control (CK), PB decreased by 90.99 % and GB increased by 93.25 %, and both PB and GB removed MGEs completely. Sulfonamide antibiotic resistance genes were the main contributor of the ARGs rebounding. PB addition could hinder the rebounding of sulfonamide antibiotic resistance genes during the later stage of the composting. Co-occurrence network analysis showed that the addition of biochar (both types) increased the complexity of the microbial community the competition of inter-phylum, which was indicated by the higher number of edge and density and lower positive connection. The different ARGs removal efficiency in these two treatments might be that PB promoted the competition both inter-phylum and potential hosts-other microbes, resulted in fewer kinds and abundance of ARGs hosts, while GB increased the stability of ARGs hosts making it more resistant to environment changes. Totally, compared with the global adjustment strategy of microbial communities, more exclusive methods focusing on the controlling of ARGs hosts should be explored to decrease the ecological risk of composting products during composting process.

Enhanced anaerobic biodegradation of typical phenolic compounds in coal gasification wastewater (CGW) using biochar: Focusing on the hydrolysis-acidification process and microbial community succession

The aim of this research is to investigate the effects of biochar (BC) on treatment performance (especially hydrolysis-acidification process) and microbial community shifts during anaerobic degradation of typical phenolic compounds in coal gasification wastewater. Compared to the control group, the removal of phenol, p-cresol and 3, 5-xylenol was gradually enhanced when increasing the BC addition within the test dosage (1-5 g/L). The biodegradation of phenol and p-cresol was significantly enhanced by BC addition while limited improvement for 3, 5-xylenol. The addition of BC significantly accelerated the hydrolysis-acidification process with the hydrolytic removal of phenol improved by 69.14%, the microbial activity was enhanced by 57.01%, and the key hydrolase bamA gene was enriched by 117.27%, respectively. Compared to 1-2 g/L dose, more protein-like and humic acid-like substances were secreted with 5 g/L BC, which probably contributed to higher extracellular electron transfer efficiency. In addition, phenol degrading bacteria (Syntrophorhabdus, Dysgonomonas, Holophaga, etc.) and electroactive microorganisms (Geobacter, Syntrophorhabdus, Methanospirillum, etc.) were enriched by BC addition. The functional genes related to carboxylation, benzoylation and ring cleavage processes of benzoyl-CoA pathway were potentially activated by BC.

The Role of CT-Based Radiomics Nomogram in Differential Diagnosis of Immune Checkpoint Inhibitor-Related Pneumonitis from Radiation Pneumonitis for Patients with ESCC

PURPOSE/OBJECTIVE(S)

The combination of immunotherapy and chemoradiotherapy has widely used for patients with esophageal squamous cell carcinoma (ESCC) and induced treatment-related adverse effects, particularly immune checkpoint inhibitor-related pneumonitis (CIP) and radiation pneumonitis (RP). The aim of this study is to differentiate between CIP and RP by the CT radiomics and clinical or radiological parameters.

MATERIALS/METHODS

A total of 76 ESCC patients with pneumonitis were enrolled in this retrospective study and divided into training dataset (n = 53) and validation dataset (n = 23). A total of 837 radiomics features were extracted from regions of interest (ROIs) based on the lung parenchyma window of CT images. A radiomics signature was constructed on the basis of the predictive features by the least absolute shrinkage and selection operator (LASSO). A logistic regression was applied to develop radiomics nomogram. Receiver operating characteristics (ROC) curve and area under the curve (AUC) were applied to evaluate the performance of pneumonitis etiology identification.

RESULTS

No significant difference was detected between training dataset and validation dataset. The radiomics signature which was made up of four radiomics features shown a favorable performance on differentiating between CIP and RP with the α-binormal-based and empirical AUC = 0.831 and 0.843. Patients with RP had a close relationship with location (p = 0.003) and shape of lesions (p = 0.002). The nomogram that combined with radiomics signature and clinical factors improved the classifying performance on discrimination in the training dataset (AUCαbin = 0.963 and AUCemp = 0.964). The results were verified in the validation dataset with AUC = 0.967 and 0.964.

CONCLUSION

CT-based radiomics features have potential values for differentiating between patients with CIP and RP. Addition of bilateral changes and sharp border produced superior model performance on classifying, which could be a useful method to improve related clinical decision-making.

Coupled pyrite and sulfur autotrophic denitrification for simultaneous removal of nitrogen and phosphorus from secondary effluent: feasibility, performance and mechanisms

The discharge standards of nitrogen (N) and phosphorus (P) in wastewater treatment plants (WWTPs) have become increasingly strict to reduce water eutrophication. Further reducing N and P in effluent from municipal WWTPs need to be achieved effectively and eco-friendly. In this study, a carbon independent pyrite and sulfur autotrophic denitrification (PSAD) system using pyrite and sulfur as electron donor was developed and compared with pyrite autotrophic denitrification (PAD) and sulfur autotrophic denitrification (SAD) systems through batch and continuous flow biofilter experiments. Compare to PAD and SAD, PSAD was more effective in simultaneous removal in N and P. At hydraulic retention time (HRT) 3 h, average effluent concentrations of total nitrogen (TN) and total phosphate (TP) of 1.40 ± 0.03 and 0.19 ± 0.02 mg/L were achieved when treating real secondary effluent with 20.65 ± 0.24 mg/L TN and 1.00 ± 0.24 mg/L TP. The improvement in simultaneous removal of N and P was attributed to the coupling of PAD and SAD in enhancing the transformation of sulfur and iron and enlarging the reaction zone in the pyrite and sulfur autotrophic denitrification biofilter (PSADB) system. Therefore, more biomass was accumulated and the microbial denitrification functional stability, including electrons transfer and consumption was enhanced on the surface of pyrite and sulfur particles in the PSADB system. Moreover, autotrophic denitrifiers (Thiobacillus and Ferritrophicum), sulfate-reducing bacteria (Desulfocapsa) and iron reducing bacteria (Geothrix), acting as contributors to microbial nitrogen, sulfur and iron cycle, were specially enriched. In addition, the leaching of iron ions was promoted, which facilitated the removal of phosphate in the form of Fe3(PO4)2·8H2O and Fe3PO4. PSADB has proven to be an efficient technology for simultaneous removal of N and P, which could meet increasingly stringent discharge standards effectively and eco-friendly.

[Bioinformatics analysis and prokaryotic expression of Strongyloides stercoralis serine protease inhibitor 1]

OBJECTIVE

To predict the structure and antigenic epitope of the Strongyloides stercoralis serine protease inhibitor 1 (Ss-SRPN-1) protein using bioinformatics tools, and to construct prokaryotic expression plasmids for expression of recombinant Ss-SRPN-1 protein, so as to provide the basis for unraveling the function of the Ss-SRPN-1 protein.

METHODS

The amino acid sequence of the Ss-SRPN-1 protein was downloaded from the NCBI database, and the physicochemical properties, structure and antigenic epitopes of the Ss-SRPN-1 protein were predicted using bioinformatics tools, including ExPASy, SWISS-MODEL and Protean. Primers were designed according to the nucleotide sequences of Ss-SRPN-1, and the Ss-SRPN-1 gene was amplified, cloned and sequenced with genomic DNA extracted from the infective third-stage larvae of S. stercoralis as a template. The Ss-SRPN-1 protein sequence was cloned into the pET28a (+) expression vector and transformed into Escherichia coli BL21 (DE) cells for induction of the recombinant Ss-SRPN-1 protein expression. The recombinant Ss-SRPN-1 protein was then purified and identified using Western blotting and mass spectrometry.

RESULTS

Bioinformatics analysis showed that the Ss-SRPN-1 protein, which was composed of 372 amino acids and had a molecular formula of C₁₉₄₈H₃₀₄₆N₄₈₈O₅₇₅S₁₆, was a stable hydrophilic protein, and the subcellular localization of the protein was predicted to be extracellular. The Ss-SRPN-1 protein was predicted to contain 11 dominant B-cell antigenic epitopes and 20 T-cell antigenic epitopes. The Ss-SRPN-1 gene with a length of 1 119 bp was successfully amplified, and the recombinant plasmid pET28a (+)/Ss-SRPN-1 was constructed and transformed into E. coli BL21(DE) cells. The expressed recombinant Ss-SRPN-1 protein had a molecular weight of approximately 43 kDa, and was characterized as a Ss-SRPN-1 protein.

CONCLUSIONS

The recombinant Ss-SRPN-1 protein has been expressed successfully, and this recombinant protein may be a potential vaccine candidate against strongyloidiasis.

Simultaneous passivation of heavy metals and removal of antibiotic resistance genes by calcium peroxide addition during sewage sludge composting

This research evaluated the effects of calcium peroxide (CP) at 0% (CK, w/w), 5% (T1, w/w), and 10% (T2, w/w), on heavy metals (HMs) mobility and prevalence of antibiotic resistance genes (ARGs) during sludge composting. T1 and T2 significantly reduced (p < 0.05) the mobility of Cu (29.34%, and 32.94%, respectively), Ni (24.07%, and 31.48%, respectively) and Zn (33.28%, and 54.11%, respectively) compared to CK after the composting. CP addition resulted in a decrease in mobile genetic elements (MGEs) and ARGs during composting. Together with structural equation model and random forest analysis depicted MGEs had a primary association with total ARGs variations during composting. Microbial analysis indicated CP downregulated the expression of the genes associated with two-component and type IV secretion system, thus reducing the prevalence of ARGs. This study demonstrates that application of CP is a feasible strategy to mitigate both ARGs and HMs hazards during composting.

[Single-cell transcriptome analysis reveals development atlas of mouse molar pulp cells]

Objective: Single-cell RNA sequencing (scRNA-seq) was used to analyze the developing mouse molars, in order to construct a spatiotemporal development atlas of pulp cells, and further to reveal the developmental process and regulatory mechanism of tooth development. Methods: Ten mandibular first molars from C57BL/6 mice in postnatal day (PN) 0 and 3 were respectively dissected and digested to obtain single-cell suspensions. scRNA-seq was performed on 10× Genomics platform. PN 7 mouse molar scRNA-seq data were obtained from our previous study. PN 0, 3, and 7 scRNA-seq data were integrated for following analysis. The initial quality control, mapping and single cell expression matrix construction were performed by Cell Ranger. Quality control, standardization, dimensional reduction and cluster analysis were performed by using Seurat. Monocle was used to generate the pseudotime trajectory. Scillus was used to perform gene ontology analysis. In order to detect the spatiotemporal change of different population of pulp cells, the marker genes of each cluster were demonstrated by RNAscope in situ hybridization. Results: There were twenty-six cell clusters within mouse molars, which were identified as eight different cell types, including dental pulp cells, dental follicle cells, epithelial cells, immune cells, endothelial cells, perivascular cells, glial cells and erythrocytes. We further re-clustered and analyzed dental pulp cells. Cluster 0 were mature pulp cells, which located at the upper portion of crown. The main functions of cluster 0 were osteogenesis and extracellular structure organization. Cluster 1 were apical papilla cells, which located at the apical part of roots, whose main functions were extracellular structure organization and organ development. Cluster 2 were cycling cells, which were actively proliferated, resided in the lower portion of the crown. Cluster 3 and 4 were preodontoblasts and odontoblasts, respectively. Their functions were closely related to biomineralization. The proportion of mature pulp cells increased with the development process, while the proportion of cycling cells and odontoblast lineage decreased. According to the expression pattern of marker genes of each cluster, we constructed a cell atlas of dental pulp. Pseudotime trajectory analysis found there were two development trajectories within dental pulp. They both started from SPARC related modular calcium binding 2 (Smoc2)+ dental papilla cells, then went through DNA topoisomerase Ⅱ alpha (Top2a)+ cycling cells, and finally divided into coxsackie virus and adenovirus receptor (Cxadr)+ mature pulp cells or dentin sialophosphoprotein (Dspp)+ odontoblasts two lineages. Conclusions: scRNA-seq could fully discover the intercellular heterogeneity of cells on transcriptome level, which provides a powerful tool to study the process and regulatory mechanism of organ development.

[Progress of researches on Strongyloides stercoralis co-infection with other pathogens]

Strongyloides stercoralis is an opportunistic pathogenic parasite that can cause severe strongyloidiasis and even death among immunocompromised individuals. Previous clinical studies have reported cases co-infected with S. stercoralis and other pathogens, such as parasites, viruses, bacteria and fungi. This review summarizes strongyloidiasis patients co-infected with pathogens, and analyzes the impact of co-infection on strongyloidiasis, so as to provide insights into the reduction of the morbidity and mortality of disorders associated with S. stercoralis infections.

Effect of calcium peroxide dosage on organic matter degradation, humification during sewage sludge composting and application as amendment for Cu (II)-polluted soils

In this research, it was the first time to investigate the effect of two dosages (5% (T1) and 10% (T2), w/w) of calcium peroxide (CP) on organic matter degradation, humification during sewage sludge composting. Additionally, the complexation of Cu to humic substance (HS) derived from CP-compost compared to no CP addition-compost (CK) was also studied. Results showed that compared to CK, T1 and T2 significantly enhanced organic matter degradation and promoted the formation of HS. Two-dimensional correlation Fourier transform infrared spectroscopy (2D-FTIR-COS) and Parallel factor (PARAFAC) analysis revealed that the addition of CP accelerated the synthesis of HS with high aromatization degree and molecular weight than those in CK, owing to the oxidation of small molecules to form carboxyl. The stability constant (log K_M) of Cu with CP-derived HS (log K_M = 4.22-5.13) indicated a greater complexation ability than CK-derived HS (log K_M = 4.05-4.45), due to the faster response of polysaccharides binding to Cu (II) and the higher humification degree of CP-derived HS. This study revealed the potential mechanisms of CP addition on the synthesis of HS and utilization of CP-compost product might provide an effective way to remedy Cu (II)-contaminated soils.

Biochar induced inhibitory effects on intracellular and extracellular antibiotic resistance genes in anaerobic digestion of swine manure

Distribution of intracellular (iARGs) and extracellular ARGs (eARGs) in manure anaerobic digestion (AD) process coupled with two types of biochar (BC and BP) were investigated. And the effects of biochar on the conjugation transfer of ARGs were explored by deciphering the interaction of biochar with bacterial stress responses, physiological metabolism and antibiotic resistances. Results showed that AD process could effectively remove all the detected eARGs with efficiency of 47.4-98.2%. The modified biochar (BP) with larger specific surface area (SSA) was propitious to decrease the absolute copy number of extracellular resistance genes. AD process could effectively remove iARGs by inhibiting the growth of host bacteria. The results of structural equation models (SEM) indicated that biochar put indirect influences on the fate of ARGs (λ = -0.23, P > 0.05). Analysis on oxidative stress levels, antioxidant capacity, DNA damage-induced response (SOS) response and energy generation process demonstrated that biochar induced the oxidative stress response of microorganisms and enhanced the antioxidant capacity of bacteria. The elevated antioxidant capacity negatively affected SOS response, amplified cell membrane damage and further weakened the energy generation process, resulted in the inhibition of horizontal transfer of ARGs.

New insights into the transformation of effluent organic matter during Fe(II)-assisted advanced oxidation processes: Parallel factor analysis coupled with self-organizing maps

The negative effects of effluent organic matter (EfOM) on receiving aquatic environments and advanced treatment facilities pose significant concerns. However, the effective removal of EfOM is challenging due to its chemically complex nature and its refractory characteristics. In this study, two Fe(II)-assisted oxidation processes including UV/Fe(II)/H₂O₂ and UV/Fe(II)/persulfate (UV/Fe(II)/PS) were investigated to promote EfOM reduction. Fe(II) was essential for promoting EfOM degradation. The mineralization rate of EfOM increased from 7 to 29% with 2 mM Fe(II) addition in the UV/H₂O₂ process and to 23% with 0.8 mM Fe(II) addition in the UV/PS process. A preliminary experiment was conducted to obtain the optimal molar ratio of oxidant to Fe(II) for practical applications based on different indicators. The form of Fe(III) prevalent at different pH values strongly affected Fe(II)/Fe(III) cycling, thus determining the progress of EfOM degradation. A machine learning approach consisting of parallel factor analysis coupled with self-organizing maps (PARAFAC-SOM) was employed with fluorescence spectra to visualize the degradation behavior of EfOM in the different reaction systems. Four components (i.e., two humic-like substances, one fulvic acid, and one tryptophan-like substance) were eventually identified, and their reductions reached more than 62% during the Fe(II)-assisted oxidation processes. The degradation orders for each component in the different oxidation processes were initially evaluated by SOM analysis with F_max percentage data. The degradation behavior of EfOM in the UV/Fe(II)/H₂O₂ and UV/Fe(II)/PS systems exhibited different trends based on the best matching unit map and component planes. The humic-like component was more refractory than the other three components in both oxidation processes. The microbial humic-like and high-molecular-weight fulvic acid substances showed higher reactivity with SO·₄^- than with ·OH, while the tryptophan-like substance was more reactive in the UV/Fe(II)/H₂O₂ system than in the UV/Fe(II)/PS system. The outcomes of this study provide new insights into the degradation behavior of EfOM, promoting the development of advanced wastewater treatments.

Potassium ferrate combined with ultrafiltration for treating secondary effluent: Efficient removal of antibiotic resistance genes and membrane fouling alleviation

Antibiotic resistance genes (ARGs) are considered as emerging environmental contaminants, which should be controlled by wastewater treatment plants to prevent their discharge into the environment. However, conventional treatment techniques generally fail to successfully reduce ARGs, and the release of cell-free ARGs was underestimated. In this study, potassium ferrate (Fe(VI)) pretreatment combined with ultrafiltration (UF) process was developed to remove both cell-associated and cell-free ARGs in real secondary effluent, compared to ferric chloride (Fe(III)) and poly-aluminum chloride (PACl) pretreatment processes. It was found that total ARGs especially cell-free ARGs were effectively removed by Fe(VI) oxidation. However, due to the poor settleability of the negatively charged particles formed by Fe(VI) in the secondary effluent, the removal of cell-associated ARGs was less compared to Fe(III) and PACl pretreatments. The combination of Fe(VI) and UF removed the most ARGs (3.26 - 5.01 logs) due to the efficient removal of cell-free ARGs by Fe(VI) (> 2.15 logs) and co-interception of both cell-associated ARGs and Fe(VI) formed particles of the UF. High-throughput sequencing revealed that Fe(VI) decreased the viability and relative abundances of the potential ARGs hosts. Fe(VI)-UF exhibited the best performance on humic-like fluorescent organic matters removal, as well as the least phytotoxicity in the effluent. Moreover, membrane fouling was remarkably alleviated by Fe(VI) pretreatment because (1) Fe(VI) removed macromolecules such as protein-like and polysaccharide-like substances which would block the membrane pores, (2) Fe(VI) improved the hydrophilicity of foulants and reduced the hydrophobic adsorption between foulants and membrane. In short, Fe(VI)-UF is a promising technology to efficiently remove ARGs (especially cell-free ARGs) and alleviate UF membrane fouling in wastewater reclamation.

Evaluation of Fe(VI)/Fe(II) combined with sludge adsorbents in secondary effluent organic matter removal

Wastewater reclamation and reuse are important methods that help to achieve an equilibrium within demand and offer, and also one of the important ways to reduce carbon emission. The existence of secondary effluent organic matter (EfOM) will bring potential threat to the environment in reuse process. Therefore, it is important to develop reclaimed water reuse technology that effectively remove EfOM. In this study, the removal of EfOM performance of ferrates enhanced by FeCl₂ (Fe(VI)/Fe(II)) combined with sludge adsorbents (SAs) was evaluated by using the continuous-flow process (FeSDF), which was composed of Fe(VI)/Fe(II), SAs, densadeg and filtration. The results showed that when the inflow rate was 1 L/h, the optimal operating conditions of FeSDF including 5 mg/L of Fe(VI), 1 mg/L of Fe(II), 1 g/L of SA and 50% of the reflux ratio. Bulk organic indicators, including chemical oxygen demand, dissolved organic carbon, ammonia, total nitrogen, total phosphorus, turbidity, and ultraviolet absorbance at 254 nm in the effluent met the water quality standard for scenic environment use (GB/T 18921-2019 in China). The addition of Fe(II) makes the coagulation process by Fe(VI) produce more Fe(III) and produce more quality of sedimentary flocs and improve the removal efficiency of EfOM. The removal of organic micro-pollutants (OMPs) was mainly due to ferrate oxidation and SA adsorption in FeSDF, and the removal of most of the OMPs was more than 90%. The total fluorescence intensity removal efficiency in FeSDF was 63.8%. Moreover, the genotoxicity of the FeSDF effluent decreased to 0.73 μg 4-nitroquiniline-N-oxide/L, and the reduction efficiency reached 97.6%. The actual efficiency of most of the indicators is greater than the expected efficiency, indicating that there is a synergistic comprehensive effect during the whole process operation of FeSDF.

Simultaneous recovery of vivianite and produce short-chain fatty acids from waste activated sludge using potassium ferrate as pre-oxidation treatment

Recovery resources from waste active sludge (WAS) is an effective way to alleviate the predicament of WAS disposal, and it is also conducive to the carbon neutralization of wastewater treatment systems. This study discussed the strategy of WAS anaerobic fermentation after pre-oxidation with potassium ferrate (K₂FeO₄, PF), which can simultaneously recover vivianite and enhance SCFAs production. The results showed that PF pre-oxidation considerably shortened the fermentation time of SCFAs to 2 days, and the main Fe-P mineral was vivianite. The optimal PF dosage of 0.06 g Fe (VI)/g TSS for pre-oxidation WAS resulted in the maximum SCFAs production and vivianite recovery rate of 3698.2 ± 118.98 mg COD/g VSS and 32.39%, respectively. The mechanism analysis showed that the oxidizing properties of PF significantly accelerated the disintegration of tight EPS, release of protein and sludge acidification efficiency. Moreover, the PF strengthened the transfer of P to the solid phase, forming the Fe-P mineral and unsaturated coordination state of phosphate group. Then the key microorganism Geobacter reduced the Fe³⁺ in Fe-P state to Fe²⁺ and combined unsaturated phosphate to form vivianite. This study provides an alternative method for resource recovery and environmentally friendly disposal of WAS and contributes to the carbon neutrality of urban water systems.

Brain functional changes in individuals with bulimia nervosa: a protocol for systematic review and meta-analysis

INTRODUCTION

Bulimia nervosa (BN) is a disorder with high health and socioeconomic burdens that typically arises in late adolescence and early adulthood. Previous neuroimaging studies have found functional brain changes in patients with BN. This study aims to review the latest neurobiological evidence from studies of individuals with BN, examine the consistency of these findings and evaluate the food addiction hypothesis of the disease.

METHODS AND ANALYSIS

A systematic search will be performed using the Cochrane Library, PubMed, Embase and Web of Science databases, covering the period from database inception to 30 November 2021. Two researchers will be responsible for study selection, quality assessment and data extraction. The anisotropic effect size version of the signed differential mapping method will be used to conduct a coordinate-based meta-analysis. Publication bias will be examined with the Egger test. The quality of studies will be evaluated using the Newcastle-Ottawa Scale.

ETHICS AND DISSEMINATION

No ethics approval is required for this is a systematic review protocol and does not require the collection of primary data. Findings will be disseminated through peer-reviewed journal or related conferences.

PROSPERO REGISTRATION NUMBER

CRD42022307233.

Rapid recovery of mixed culture polyhydroxyalkanoate production system from EPS bulking using azithromycin

The long-term stable operation of the mixed culture polyhydroxyalkanoate (PHA) enrichment stage is the guarantee for the continuous synthesis of PHA, however extracellular polymeric substances (EPS) sludge bulking occurred from time to time may cause the operation fail. In order to solve this problem, as a quencher of signal molecules and antibiotic, azithromycin (AZM) was used in the two systems with different modes to recover the sedimentation capacity of the sludge. The results showed that AZM addition resulted in the reduction of polysaccharide /protein (PS/PN) ratio in EPS and significant improvement of the sedimentation capacity of the sludge. Quorum quenching of AZM or aiiA gene maintained the sedimentation ability of the sludge in a relay mode. By adding AZM, the growth of Thauera and Flavobacterium, which caused sludge bulking, was inhibited. Paracoccus, a strong PHA producer, has been enriched to ensure that the maximum PHA synthesis of the system.

Microbial community competition rather than high-temperature predominates ARGs elimination in swine manure composting

Aerobic composting is commonly used in pig manure treatment, however, antibiotic resistance genes (ARGs) and their unclear transformation during composting process make the treated manure land using risky. The effects of enhanced thermophilic phase strategy (external heating (HTC) and thermophiles inoculation (MC)) on ARGs removal and the underlying mechanisms were investigated during swine manure composting. HTC increased the total relative abundance (RA) of ARGs by 32.38%, and MC decreased by 21.50% compared to CK by the end of the composting. Mantel test indicated that it was not temperature (P > 0.05), but environmental parameters (pH, Electric Conductivity (EC), etc.) and metabolic products (nitrogen forms) significantly affected the ARGs profile. Partial least-squares path modeling (PLS-PM) suggested that microbial community structure (bacterial abundance and diversities) was the main factor for ARGs evolution. Co-occurrence analysis revealed that HTC could promote the propagation of ARG hosts in later stage of the composting because the strong selection of thermophiles resulted in ecological niches vacancy, and MC enhanced the competition between hosts and nonhosts for ecological niches by increasing thermophiles diversities. These results suggested that competitive inhibition to potential ARGs hosts could be a helpful strategy in ARGs threaten elimination during composting.

Effects of H3PO4 modified biochar on heavy metal mobility and resistance genes removal during swine manure composting

In this research, static composting treatments of swine manure with forced ventilation were conducted to study the effects of biochar (BC) and H₃PO₄ modified biochar (BP) addition on heavy metals (HMs) stabilization, profiles of antibiotic resistance genes (ARGs), heavy metals resistance genes (MRGs) and bacterial communities during swine manure composting. After 42 days of the composting, compared to control (CK), BC and BP decreased the concentration of diethylenetriamine pentaacetic acid extractable Cu and Zn by 12.04%, 15.15% and 26.91%, 36.50%, respectively. Furthermore, BC and BP treatments reduced the total abundances of nine ARGs by 4.02% and 66.21%, and five MRGs by 53.66% and 58.81%, compared to CK in the compost product. Network analysis and square structural equation model analysis revealed that the decrease of ARGs and MRGs in BP treatment was related tothe change in bacterial community during the composting, rather than differences in co-selection pressure.

Response of antibiotic resistance to the co-exposure of sulfamethoxazole and copper during swine manure composting

Heavy metals driven co-selection of antibiotic resistance in soil and water bodies has been widely concerned, but the response of antibiotic resistance to co-existence of antibiotics and heavy metals in composting system is still unknown. Commonly used sulfamethoxazole and copper were individually and jointly added into four reactors to explore their effects on antibiotic resistance genes (ARGs), mobile genetic elements (MGEs), heavy metal resistance genes (MRGs) and bacterial community structure. The abundance of total ARGs and MGEs were notably decreased by 68.64%-84.95% and 91.27-97.38%, respectively, after the composting. Individual addition of sulfamethoxazole, individual addition of copper, simultaneously addition of sulfamethoxazole and copper increased the abundance of ARGs and MGEs throughout the composting period. Co-exposure of sulfamethoxazole and copper elevated the total abundance of ARGs by 1.17-1.51 times by the end of the composting compared to individual addition of sulfamethoxazole or copper. Network analysis indicated that the shifts in potential host bacteria determined the ARGs variation. Additionally, MGEs and MRGs had significant effects on ARGs, revealing that horizontal gene transfer and heavy metals induced co-resistance could promote ARGs dissemination.

Effect of KH2PO4-modified biochar on immobilization of Cr, Cu, Pb, Zn and as during anaerobic digestion of swine manure

In this study, the immobilization performance and mechanisms of heavy metals (HMs) in swine manure (SM) during anaerobic digestion (AD) with biochar (BC) and KH₂PO₄-modified biochar (BP) were investigated. BC and BP addition decreased DTPA-extractable Cr, Cu, Pb and Zn amount, transformed these HMs to more stable state, and decreased the ecological risks of these HMs by 2 grades accordingly. BP exhibited a higher passivation efficiency for Cr, Cu and Pb and 5% -10% biochar dosage showed the maximum passivation effects. Characterization results showed that Cr, Cu and Pb immobilization with BP were mainly attributed to the formation of phosphate precipitation. However, both DTPA extraction and mobility of As increased with biochar addition, because the release of phosphorus in biochar had negative effect on As immobilization. BP could serve as a novel remediation agent for Cr, Cu, Pb and Zn passivation but special attention should be paid with As presence.

Effects of polyurethane foam carrier addition on anoxic/aerobic membrane bioreactor (A/O-MBR) for coal gasification wastewater (CGW) treatment: Performance and microbial community structure

Coal gasification wastewater (CGW) is a typical toxic and refractory industrial wastewater with abundant phenols contained. Two identical anoxic/aerobic membrane bioreactors (with (R2) and without (R1) polyurethane (PU) foam) were carried out in parallel to investigate the role of PU foam addition in enhancing pollutants removal in CGW. Results showed that both systems exhibited effective removal of chemical oxygen demand (>93%) and total phenols (>97%) but poor ammonia nitrogen removal (<35%) constrained by ammonia oxidation process. GC-MS analysis revealed that aromatic and other refractory intermediates were dramatically reduced in R2. Moreover, the PU addition had negligible influence on the total soluble microbial products and extracellular polymeric substances contents but significantly alleviated membrane fouling with the operating time 33% prolonged. Microbial community revealed that Flavobacterium, Holophaga, and Geobacter were enriched on PU. Influent type might be a main driver for microbial community succession.

Transcriptome profiling reveals morphogenesis-related candidate genes and pathways in the chick embryonic small intestine

1. A better understanding of intestinal development is essential for the intestinal health of poultry. Intestinal villification starts on embryo day E15 and is generally completed before hatching (E21). The development of lymphoid organs in the intestine starts during embryogenesis. However, transcriptional information on the processing of intestinal morphogenesis and immune development during chick embryogenesis is limited.2. In this work, RNA-sequencing was performed using 12 biological replicates to investigate Hy-Line brown chick embryonic small intestinal transcription at E15 and E21. Differentially expressed genes (DEGs) between E15 and E21 were identified. GO and KEGG enrichment analyses, based on the DEGs, were performed to identify key GO terms in the biological process category and key KEGG pathways. PPI networks were constructed based on the DEGs in the key pathways to screen hub genes. The embryonic small intestinal morphology and IgA distribution were observed by histological processing. The serum levels of IgA and lysozyme were measured by ELISA.3. A total of 76.38 Gb of high-quality RNA-sequencing data were generated and uploaded. A total of 2,676 DEGs, between E15 and E21, were identified. Structural development and villification of the small intestine at E15 tended to proceed via the expression of nervous system development-related genes. A combination of the histological and serological results with the transcriptome data indicated that the identified genes and pathways may be strong candidates for intestinal morphogenesis-regulation.4. The small intestine appears to have developed a relatively complete morphology and transport, metabolism, digestion and immunity functions by E21. This work provided a transcriptome profile of the chick embryonic small intestine and provided insights into the intestinal development and health of poultry.

Clinical features of patients with HER2-positive breast cancer and development of a nomogram for predicting survival

Background

Different estrogen receptor (ER) and progesterone receptor (PR) expression patterns have important biological and therapeutic implications in patients with human epidermal growth factor receptor 2 (HER2)-positive breast cancer. However, little is known about hormone receptor (HR)-positive and triple-positive subtypes, making therapy selection and survival prognosis difficult. This study investigated the clinical characteristics and nomogram-predicted survival of patients with HER2-positive breast cancer.

Materials and methods

Data on patients with HER2-positive breast cancer were retrieved from the Surveillance, Epidemiology, and End Results database. Comparisons were carried out between single HR-positive and double HR-positive/double HR-negative subtypes. A nomogram-based model of predicted outcomes was developed.

Results

This cohort study included 34 819 patients with breast cancer (34 606 women and 213 men). Single HR-positive and double HR-positive/double HR-negative subtypes showed distinct clinicopathological characteristics. Multivariable Cox regression analysis showed that patients with ER-positive/PR-negative/HER2-positive [hazard ratio (HR) = 1.24; 95% confidence interval (CI): 1.14-1.39], ER-negative/PR-positive/HER2-positive (HR = 1.56; 95% CI: 1.23-1.97), and ER-negative/PR-negative/HER2-positive (HR = 1.56; 95% CI: 1.43-1.70) subtypes had worse breast cancer-specific survival than patients with the triple-positive subtype. Thirteen clinical parameters were included as prognostic factors in the nomogram: age, sex, race, grade, histology type, bone, brain, liver, and lung metastasis, TNM (tumor–node–metastasis) staging, and molecular subtype. The C-index was 0.853 (95% CI: 0.845-0.861). Calibration plots indicated that the nomogram-predicted survival was consistent with the recorded 3-year and 5-year prognoses.

Conclusions

Significant differences in survival rates were observed between single HR-positive and double HR-positive/double HR-negative subtypes. A nomogram accurately predicted survival. Different treatment strategies may be required for HER2-positive patients with single HR-positive and double HR-positive tumors to ensure optimal treatment and benefits.

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Significant differences in survival were observed in single HR-positive and double HR-positive/double HR-negative subtypes.

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A nomogram based on molecular subtypes of HER2-positive breast cancer accurately predicted breast cancer-specific survival.

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Different treatment strategies may be required for HER2-positive breast cancer to ensure optimal treatment and benefits.

Application of potassium ferrate combined with poly-aluminum chloride for mitigating ultrafiltration (UF) membrane fouling in secondary effluent: Comparison of oxidant dosing strategies

Coagulation has been widely applied as a pretreatment for ultrafiltration (UF) membrane in wastewater reclamation, however, it is unable to effectively ensure the removal of organic micropollutants (OMPs) and genotoxicity. To solve this problem, oxidant ferrate (VI) (Fe^VIO₄^2-, Fe^VI) was combined with coagulant poly-aluminum chloride (PAC) as the pretreatment of UF to treat secondary effluent, and three oxidant dosing strategies (namely oxidation followed by coagulation (O-Fe^VI-PAC), simultaneous oxidation and coagulation (S-Fe^VI-PAC), and coagulation followed by oxidation (C-PAC-Fe^VI)) were compared at two oxidant doses. The results showed that C-PAC-Fe^VI pretreatment exhibited the best performance for the removal of DOC (35.9%), UV₂₅₄ (33.7%), protein (71.8%), and polysaccharide (22.1%). Molecular weight and fluorescence analysis revealed that the removed organics were mainly humic substances. Both the direct UF process and PAC pretreatment showed limited removal of OMPs and genotoxicity, however, the combined pretreatments of Fe^VI and PAC dramatically removed them. The maximum removal efficiency of the fourteen selected OMPs and genotoxicity was obtained under S-Fe^VI-PAC (59.6% on average) and C-PAC-Fe^VI (84.1%), respectively. With respect to membrane fouling control, the normalized flux reduction showed an apparent regularity of C-PAC-Fe^VI > O-Fe^VI-PAC > S-Fe^VI-PAC, however, Fe^VI dose should be carefully determined. The addition of Fe^VI delayed the transition of membrane fouling mechanism from pore blockage to cake filtration, especially in C-PAC-Fe^VI pretreatment, which was confirmed by the fluorescence characterization of hydraulic reversible and hydraulic irreversible foulants. To sum up, C-PAC-Fe^VI dosing strategy seems to have more potential in membrane fouling alleviation and effluent quality improvement.

Effect of inoculum and organic loading on mixed culture polyhydroxyalkanoate production using crude glycerol as the substrate

Two different sources of activated sludge were inoculated to select and enrich polyhydroxyalkanoate (PHA) producing culture from crude glycerol. The results showed that the sludge taken from the wastewater treatment plant with higher microbial diversity could enrich PHA producing culture with higher PHA synthesis capacity (25.93%) and specific PHA storage rate (0.27 mg COD/(mg·h)) in a short enrichment time, comparing to the sludge taken from the enriched PHA-producing culture using VFAs as the substrate. The enrichment performance under different organic loadings were investigated and similar microbial community composition, good operating stability and high PHA accumulation (SBR#1, 36.59%; SBR#2, 36.33%) was observed at 2000 mg COD/(L·d) when crude glycerol was used as the substrate. The maximum content of PHA was affected by the concentration of glycerol. Gardnerella was for the first time found to be the dominant genus in the PHA production system using crude glycerol. The research would guide the application of using crude glycerol resources for PHA production.

Coating magnetite alters the mechanisms and site energy for sulfonamide antibiotic sorption on biochar

Magnetite-coating biochar (MBC) is a promising remediator for antibiotic contamination. Accurate models describing the sorption affinity are required to better understand the role of minerals. In this study, the presence of magnetite led to the improvements of oxygen-containing groups (i.e. C˭O) and regulation of π-systems within BC. Based on Dubinin-Ashtakhov (DA) model, the differences of site energy (E_m) and sorption heterogeneity (σ_e*) led to the variances between sorption capacities of sulfonamides (SAs). The positive correlations between E_m and the oxygen content or pore volume of MBCs indicated that π-π interactions, H-bonding, and pore-filling may act as the high energy sites. Moreover, σ_e* was related to the distribution of magnetite on BC and their porosities. These results suggested that compared to BCs, the coating minerals improved the π-interaction assisted H-bonding and proton configuration of antibiotic when sorbing on MBC. The negative correlations between the E_m of different SAs with their molecular sizes and solubilities resulted from steric effects and competition with water, which further confirmed the proposed high energy sites on MBCs. This study provided the insightful information of site energy distribution and understanding of fate and transport of organic pollutants on BC when the iron minerals were embedded or coated.

Sorption mechanisms of antibiotic sulfamethazine (SMT) on magnetite-coated biochar: pH-dependence and redox transformation

Sorption of sulfonamides (SAs) on magnetite-coated biochar (MBC) is a promising approach for the remediation of antibiotic contaminants, due to its extended adsorption capacity and irreversibility. However, the actual sorption mechanisms of SAs on MBC remain unclear and the gap in knowledge hinders understanding of the fate of SAs in soils or sediments. In this study, various MBCs were prepared under different pyrolysis temperatures, with batch sorption experiments conducted using SMT as the model pollutant. Results of a two-compartment kinetic model demonstrated that aromatic components of MBCs dominated slow-sorption mechanisms, whereas the embedded magnetite further accelerated fast-sorption due to H-bonding. Modification of BC with magnetite improved the distribution coefficient (K_d) and isotherm linearity of SMT. Multi-parameter model results indicated that the pH-dependence of SMT sorption on BCs and MBCs occurred via a dominant mechanism of π-bond assisted H-bonding. Compared to pristine BCs, the change in pH-dependent sorption characteristics of SMT on MBC results from the regulation of π-bonding and proton configuration. Simultaneous transformation of SMT to sulfate ions on BCs or MBCs was also observed. The degradation of SMT occurred because of persistent free radicals (PFRs) on BCs or the inherent redox of iron minerals on MBCs. However, the small fraction of SMT transformed on BCs or MBCs was not found to result in overestimation of SMT sorption. This study presents the critical mechanisms of SMT sorption on pyrochars and provides novel understanding of the fate of SMT on carbonaceous materials during practical remediation applications.

Impacts of biochar on anaerobic digestion of swine manure: Methanogenesis and antibiotic resistance genes dissemination

This work aimed to study the effects of biochar on methanogenesis and antibiotic resistance genes (ARGs) fate during anaerobic digestion (AD) of swine manure (SM) was investigated. Under the optimal biochar dosage of 5-10%, methane yield was significantly improved by 25%, ascribing to the enhancement of direct interspecies electron transfer (DIET). Biochar addition alleviated the need of cytochrome-c as interspecies electron connection components and enriched the microbes involved in DIET. Defluviitoga, Thermovirga and Cloacibacillus were dominant with biochar addition and might participate in DIET together with Methanothrix. The abundance of parC, tetX, bla_CTX-M, bla_TEM, aac(6')-Ib-cr, ermB and tetW were significantly reduced in biochar treatments and intI1 removal increased by 15% in B-5% than the control. Structural equation models demonstrated that intI1 (λ = 0.59, P < 0.001) had the most standardized direct effects on ARGs, while biochar indirectly affected ARGs by changing intI1 (λ = 0.41, P < 0.01) and microbial structure (λ = -0.24, P < 0.05).

Evaluation of a hybrid process of magnetic ion-exchange resin treatment followed by ozonation in secondary effluent organic matter removal

The presence of effluent organic matter (EfOM) and organic micro-pollutants (OMPs) in secondary effluent is receiving increasing concern due to their potential impacts on the aquatic environment and human health. In this study, the removal characteristics of EfOM by magnetic ion-exchange resin (MIEX), ozonation, and the hybrid process of MIEX followed by ozonation (M + O) were compared by measuring the bulk organic indicators (BOIs), OMPs, bio-toxicity, and fluorescence. Furthermore, the desorption characteristics of MIEX were comprehensively studied. Ozonation could reduce the OMPs, total fluorescence (TF), genotoxicity, and oestrogenic activity more effectively than MIEX, with reductions of 80.3%, 97.8%, 98.9%, and 94.6%, respectively. The M + O process was capable of removing more EfOM than the individual MIEX or ozonation processes and could reduce the genotoxicity and oestrogenic activity to the detection limit. By implementing MIEX as a pre-treatment, the generation of ammonia-nitrogen and nitrate-nitrogen was effectively reduced in the subsequent ozonation process as MIEX adsorbed organic nitrogen and nitrite-nitrogen. The different regenerants influenced the OMP desorption performance of MIEX by changing the desorption mechanisms, and NaCl + NaOH was the best regenerant due to its high total OMP desorption efficiency. Parallel factor analysis coupled with self-organising maps further explained the differences in fluorescence desorption due to the addition of NaOH to the regenerated solution. Pearson correlation analysis indicated the potential of using spectroscopic indicators, such as ultraviolet absorbance and TF, to assess the evolution of OMPs and bio-toxicity during the M + O and MIEX desorption processes.

Mechanism concerning the occurrence and removal of antibiotic resistance genes in composting product with ozone post-treatment

The soil application of composting product will probably cause the spread of antibiotic resistance genes (ARGs) to environment, thereby it is crucial to remove ARGs in composting product. Ozone was adopted for the first time as a post-treatment method to remove the ARGs in composting product in this study. Ozone treatment significantly removed the total ARGs and mobile genetic elements (MGEs) once ozonation process finished. After 10-day storage stage, although the amount of total intracellular ARGs and MGEs increased, the total extracellular ARGs and MGEs decreased in the ozone-treated compost product. Correlation analysis revealed that the reduction in intracellular 16S rRNA contributed to intracellular tetQ and tetW removal, while the variations of other ARGs after ozonation related to MGEs abundance. Network analysis suggested that the reduction of potential host bacteria, as well as the decline in NH₄⁺-N and TOC after the ozonation, contributed to the intracellular ARGs removal.

Variation of heavy metal speciation, antibiotic degradation, and potential horizontal gene transfer during pig manure composting under different chlortetracycline concentration

Overuse of heavy metal and antibiotics in livestock husbandry has led to the accumulation of heavy metal resistance genes (HMRGs) and antibiotic resistance genes (ARGs) in environment. This research aims to reveal the variation of heavy metal speciation and potential horizontal gene transfer (HGT) of HMRGs and ARGs in manure composting under different initial chlortetracycline (CTC) concentrations. Treatments spiked with 20 mg/kg CTC (treatment P1), 100 mg/kg CTC (treatment P2), and the control (treatment CK) were operated. Results showed that CTC could be completely removed in the thermophilic phase of all the treatments despite of the initial concentrations. Bioavailable Cu in treatments CK, P1, and P2 declined by 14.5%, 27.1%, and 26.7% and bioavailable Zn declined by 15.3%, 29.5%, and 12.1%, respectively, after the composting, respectively. Relative abundance of HMRGs decreased by 6.49 log, 8.88 log, and 5.77 log, respectively, in treatments CK, P1, and P2. Relative abundance of ARGs decreased by 3.37 log, 4.86 log, and 3.32 log, respectively, in treatments CK, P1, and P2. Composting could effectively reduce genes pcoD, pcoA, zntA, tetQ, and tetA, which might locate on the same plasmid. CTC of 100 mg/kg promoted the co-selection of ARGs and HMRGs and increased the potential HGT of gene cusA.

Effects of lime amendment on the organic substances changes, antibiotics removal, and heavy metals speciation transformation during swine manure composting

Aerobic composting has been used for a long time for bioconversion of manure wastes, however, its application has been limited due to slow transition of organic matters and influence of heavy metals and antibiotics residues. Compost with lime addition can speed up the composting process, while its effects on the evolution of organic matters, heavy metals and antibiotics need to be further investigated. In this research, the effects of lime amendment on organic substances changes was assessed by the spectroscopic characteristics. Besides, chlortetracycline (CTC) removal and Cu, Zn chemical speciation transformation were also evaluated. Results showed that the humic acid-like substances region of fluorescence regional integration (FRI-EEM) increased from 20.5% to 40.9% and 20.6%-32.6%, respectively, in lime addition treatment and control after 15 days of composting, indicating that the addition of lime remarkably improved the transition of organic matter and accelerated the maturity process. Besides, 94.04% of CTC in the manure was removed when lime was added, higher than 86.10% in the control group. The transformation of zinc from exchangeable and reducible into oxidizable and residual fractions was improved while the transformation of copper was affected slightly. Therefore, lime is a suitable amendment material for manure composting, which can accelerate the transition of organic matters due to the regulation of composting pH, as well as eliminate harmful CTC and bioavailable heavy metal, thus promoting the further utilizing of organic substance.

Different subsets of haematopoietic cells and immune cells in bone marrow between young and older donors

Young donors are reported to be associated with better transplant outcomes than older donors in allogeneic hematopoietic stem cell transplantation (allo-HSCT), but the mechanism is still unclear. The current study compared the different subsets of haematopoietic stem cells (HSCs) and their progenitors as well as immune cells in bone marrow (BM) between young and older donors. The frequencies of HSCs, multipotent progenitors (MPPs) and myeloid progenitors, including common myeloid progenitors (CMPs) and megakaryocyte-erythroid progenitors (MEPs), were decreased, whereas those of lymphoid progenitors, including multi-potent lymphoid progenitors (MLPs) and common lymphoid progenitors (CLPs), were increased in the BM of young donors compared with in that of older donors. Lower reactive oxygen species (ROS) levels were observed in BM HSCs and six progenitor lines in young donors. Furthermore, young donors demonstrated higher frequencies of naive T cells and immune suppressor cells, such as alternative macrophages (M2) and lower frequencies of memory T cells and immune effectors, including T helper-1 and T cytotoxic-1 cells, in BM than older donors. Multivariate analysis demonstrated that donor age was independently correlated with BM HSC frequency. Although further validation is required, our results suggest that the differences in the frequency and immune differentiation potential of HSCs in BM between young donors and older donors may partly explain the different outcomes of allo-HSCT.

Use of sodium chloride to rapidly restore polyhydroxyalkanoates production from filamentous bulking without polyhydroxyalkanoates productivity impairment

Occurrence of filamentous bulking would lead to excess biomass washout to fail the polyhydroxyalkanoate (PHA) production process. A strategy using sodium chloride (NaCl) addition to enhance sludge settleability so that high PHA productivity could be retained was tested in two sequencing batch reactors (SBR #1 and #2) fed with different organic acid mixtures but at identical NaCl gradients (0, 5 and 10 g/L). Significant improved sludge settleability was observed at 10 g/L NaCl regardless of occurrence of filamentous bulking. The NaCl addition strategy suppressed the growth of principal filamentous bacterium, Meganema, and enriched the PHA producers (Paracoccus and Thauera) to reach enhanced PHA productivities of 0.244-0.298 g/L^-1 d^-1 for the present studied system.

Evaluation of enhanced coagulation combined with densadeg-ultrafiltration process in treating secondary effluent: Organic micro-pollutants removal, genotoxicity reduction, and membrane fouling alleviation

Conventional coagulation is widely used as an ultrafiltration membrane pretreatment process in wastewater reclamation, however it shows little ability to reduce organic micro-pollutants (OMPs) and genotoxicity. In this research, powdered activated carbon (PAC) and potassium ferrate were used respectively with polyaluminum chloride (PACl) to enhance coagulation. Filtration experiments of coagulation (CUF), coagulation-adsorption (CAUF) and coagulation-oxidation (COUF) pretreatment combined with densadeg-ultrafiltration processes were conducted under their optimum doses. The effluent water quality of CAUF and COUF could meet the water reuse quality standard for scenic environment use, while total phosphorus in the conventional CUF discharge was higher than the standard. The average removal efficiency of the selected fourteen OMPs was significantly improved by 1.8 times through the CAUF process compared to the CUF process (31.2%), whereas the COUF process (38.4%) showed limited improvement. Prominent reduction of genotoxicity was observed in the CAUF and COUF processes, and the effluent of the CAUF process had the least genotoxicity of 1.0 ± 0.3 μg 4-Nitroquinoline-N-oxide (4-NQO)/L. Moreover, the average transmembrane pressure increasing rate followed the order of CUF (1.5 kPa/d) > COUF (1.1 kPa/d) > CAUF (0.6 kPa/d), indicated that the enhanced coagulation process could relieve membrane fouling effectively.

Substrate strategy optimization for polyhydroxyalkanoates producing culture enrichment from crude glycerol

Crude glycerol is by-product produced from biodiesel industry and can be converted directly by mixed microbial culture (MMC) into polyhydroxyalkanoates (PHAs). This study investigated the effects of the reverse (SBR_A) and positive (SBR_B) glycerol gradient substrate strategy on PHA-accumulating culture enrichment and the maximum PHA accumulating stability under substrates with different glycerol and volatile fatty acid (VFA) proportion. The results showed that crude glycerol was mainly used for PHA production rather than biomass growth in SBR_A. The maximum q_PHA was 0.65 g COD/g X^-1·h^-1 under sole crude glycerol condition in SBR_A, which was 2.41 times higher than that of SBR_B. Moreover, the PHA accumulating ability of the biomass from SBR_A was more stable than SBR_B. Saccharibacteria_genera_incertae_sedis was for the first time found to be the dominant genus using crude glycerol for PHA production. This research provides an insight into enrichment strategy to effectively enrich PHA-accumulating culture from crude glycerol.

Impacts of Cu and Zn on the performance, microbial community dynamics and resistance genes variations during mesophilic and thermophilic anaerobic digestion of swine manure

In this work, fate of antibiotic resistance genes (ARGs), heavy metal resistance genes (MRGs) and intI1 were investigated during mesophilic (mAD) and thermophilic anaerobic digestion (tAD) of swine manure with presence of Cu and Zn. Results showed that metal reduced the lag phase time. Cu showed stronger inhibition than Zn on archaea community and metals inhibited the growth of acetoclastic methanogens during mAD. Although total concentration of metals increased after AD, they were transformed into stable state. The abundance of qnrS, sul1, sul2 and drfA7 increased 1.2-5.7 times after mAD, while reduced after tAD, showed that tAD was effective in ARGs removal. Structural equation model analysis suggested that intI1 had the most standardized direct effects on ARGs variation in mAD (R = 0.85, p < 0.01), while the co-occurrence of MRGs with ARGs showed significantly positive influences on ARGs variation in tAD (R = 0.82, p < 0.01).

Investigation of hydrolysis acidification process during anaerobic treatment of coal gasification wastewater (CGW): Evolution of dissolved organic matter and biotoxicity

Coal gasification wastewater (CGW) contains several types of aromatic pollutants, which impart high biotoxicity and reduce the quality of anaerobic treatment. Two types of hydrolysis acidification processes, namely microaerobic hybrid reactor (HA-1) and upflow anaerobic sludge blanket reactor (HA-2), were developed for pre-treatment before the anaerobic treatment. The changes in the dissolved organic matter and biotoxicity were investigated to comprehensively understand the degradation process. The results showed that HA-2 coupled with an anaerobic reactor achieved a 12.3% and 13.4% higher removal efficiency for chemical oxygen demand and total phenols, respectively, compared with the coupled process with HA-1. Furthermore, HA-2 could transform macromolecules into small molecules more efficiently and produce fewer intermediates. The coupled process with HA-2 preferentially removed complex aromatic substances with absorption wavelengths of 285 and 254 nm, according to the sequential orders interpreted from two-dimensional correlation spectroscopy. In addition, the results of fluorescence excitation-emission-matrix with regional integration analysis revealed that the contents of typical cyclic compounds in CGW, such as phenolic, heterocyclic, and polycyclic aromatic compounds were remarkably reduced by HA-2. In addition, HA-2 reduced the toxic unit value of CGW by 67.5% and increased the resazurin dehydrogenase activity of the sludge by 37.5% during CGW treatment, thus improving the biotoxicity removal and biodegradability. However, the coupled process with HA-2 did not significantly affect the "indirect estrogenic activity" of CGW. A Pearson correlation analysis indicated that spectral indicators, such as UV₂₅₄ and Φ_T,n, presented a high positive correlation with the reduction of acute toxicity and organics.

Electrochemical pretreatment of coal gasification wastewater with Bi-doped PbO2 electrode: Preparation of anode, efficiency and mechanism

Coal gasification wastewater (CGW) contains a large amount of toxic pollutants, which seriously affects the subsequent biochemical treatment. In order to investigate the efficiency of electrocatalytic oxidation on pretreatment of CGW, lead dioxide electrodes doped with PEG and Bi were successfully prepared. Scanning electron microscopy, energy dispersive spectroscopy and X-ray diffraction were comprehensively used to characterize the lead dioxide electrode and the electrochemical performance was also tested by linear sweep voltammetry curve, cyclic voltammetry curve and AC impedance. Biodegradability and toxicity of CGW were evaluated by dehydrogenase activity and acute toxicity, respectively. Results showed that the doping of PEG and Bi significantly improved the electrochemical performance and catalytic oxidation performance of lead dioxide electrodes. The degradation rate of phenol by Sn-Sb/PbO₂ (PEG + Bi) electrode were 1.57 times of that by pure lead dioxide electrode. The removal of TOC and total phenols were 53.2% and 82.7%, respectively at 120 min under 40 mA cm^-2 by Sn-Sb/PbO₂ (PEG + Bi) electrode. The changes of biodegradability, biological toxicity and by-products were analyzed. Furthermore, 3,5-dimethylphenol was used as characteristic pollutant to study the degradation mechanism of phenolic pollutants in electrocatalytic system. According to the intermediate products detected by GC-MS, possible degradation pathways in electrocatalytic system were proposed.

Comparison of ozonation and UV based oxidation as pre-treatment process for ultrafiltration in wastewater reuse: Simultaneous water risks reduction and membrane fouling mitigation

Wastewater reuse risk and membrane fouling are two concerns in ultrafiltration (UF) of secondary effluent (SE) for wastewater reuse. In this work, several wastewater reuse risk issues, such as dissolved effluent organic matters (dEfOM), organic micro-pollutants (OMPs) and bio-toxicity of SE, as well as membrane fouling were comprehensively investigated when ozonation, UV/H₂O₂ and UV/persulfate (UV/PS) were used as the pre-treatments for UF process. To be specific, individual UF could remove DOC and UV₂₅₄ by only 7.5% and 19.8%, respectively, however, humics were largely degraded during the pre-oxidation processes revealed by molecular weight and fluorescence analysis. UF and ozonation showed limited removal of OMPs, however, UV/H₂O₂ and UV/PS dramatically degraded all the OMPs by more than 80%. Genotoxicity were not detected after the oxidation treatment. Membrane fouling may result from the collaborative effect of organic components, such as humic and protein like substances. Fourier transform infrared spectra of the fouled membranes showed that aromatic CC group and polysaccharides group in dEfOM were largely reduced after the oxidation pre-treatments, resulting in the improved membrane flux sustaining. Increased roughness of the membranes in the combined process supported that the less organics content after the oxidation pre-treatment contributed to improve the performance of the UF process. For the excellent organics degradation in UV/PS pre-treatment process, membrane fouling of subsequent UF process showed maximum mitigation.

Effects of multiple antibiotics on greenhouse gas and ammonia emissions during swine manure composting

Antibiotics are commonly used in intensive farming, leading to multiple antibiotic residue in livestock waste. However, the effects of multiple antibiotics on the emissions of greenhouse gas and ammonia remain indistinct. This paper selects sulfamethoxazole and norfloxacin to represent two different types of antibiotics to explore their effects on gaseous emissions. Four treatments including CK (control), SMZ (spiked with 5 mg kg^-1 DW sulfamethoxazole), NOR (spiked with 5 mg kg^-1 DW norfloxacin), and SN (spiked with 5 mg kg^-1 DW sulfamethoxazole and 5 mg kg^-1 DW norfloxacin) were composted for 65 days. Coexistence of sulfamethoxazole and norfloxacin facilitated the biodegradation of organic carbon, and significantly (p < 0.05) increased the cumulative CO₂ emission by 31.9%. The cumulative CH₄ emissions were decreased by 6.19%, 23.7%, and 27.6% for SMZ, NOR, and SN, respectively. The total NH₃ volatilization in SMZ and NOR rose to 1020 and 1190 mg kg^-1 DW, respectively. The individual existence of sulfamethoxazole significantly (p < 0.05) ascended the N₂O emission rate in the first 7 days due to the increase of NO₂^--N content. In addition, coexistence of sulfamethoxazole and norfloxacin notably dropped the total greenhouse gas emission (subtracting CO₂) by 15.5%.