A new consistent modeling framework for the competitive adsorption of humic nanoparticles and oxyanions to metal (hydr)oxides: Multiple modes of heterogeneity, fractionation, and conformational change

HYPOTHESIS

The competitive interaction of oxyanions and humic nanoparticles (HNPs) with metal (hydr)oxide surfaces can be used to trace the ligand and charge distribution of adsorbed HNPs in relation to heterogeneity, fractionation, and conformational change.

EXPERIMENTS

Batch adsorption experiments of HNPs on goethite were performed in the absence and presence of phosphate. The size of HNPs was measured with size exclusion chromatography. The Ligand and Charge Distribution (LCD) model framework was further developed to describe the simultaneous interaction of HNPs and phosphate with goethite.

FINDINGS

Preferential adsorption decreases the mean molar mass of adsorbed HNPs, independent of the phosphate presence, showing a linear dependency on the adsorbed HNPs fraction. Phosphate ion can be used as a probe to trace the distribution of functional groups and the variation in affinity of HNPs. The spatial distribution of adsorbed HNPs is driven by the potential gradients in the electrical double layer, which changes the conformation of the adsorbed HNPs. At the particle level, the adsorption of heterogeneous HNPs has an affinity distribution, which can be explained by the variation in molar mass (kDa) and density of the functional groups (mol kg-1) of the HNPs. The presented model can simultaneously describe the competitive adsorption of HNPs and phosphate in a consistent manner.

Electric field as extracellular enzyme activator promotes conversion of lignocellulose to humic acid in composting process

To promote efficient conversion of lignocellulose to humus (HS) during composting, a novel bio-electrochemical technology was applied and explored the effect and mechanism of electrification on carbon conversion during different composting periods. The results showed that supplementary electric field played different roles during composting. In the early stage, organic matter mineralization was significantly accelerated under electric field application, that was embodied in a 29.8% increase of CO2 emission due to the enhanced metabolic activity of microorganisms. However, the electric field functioned as an extracellular enzyme activator during the later stage since the abundance of functional microorganisms related to lignocellulose degradation was increased by 1.5-2.8 fold that effectively promoted the conversion of lignocellulose to HS. The humic acid content of the compost products increased by 23.0-32.9% compared with control. This study elucidated how electric fields affect carbon conversion during composting, which provides a novel strategy for returning agricultural wastes to soil.

Combined pollution and soil microbial effect of pesticides and microplastics in greenhouse soil of suburban Tianjin, Northern China

Current-used pesticides (CUPs) and plastic films are essential materials used in greenhouse cultivation, which can lead to the residual accumulation of CUPs and microplastics (MPs) over time. The impact of CUPs and MPs on soil quality and food safety cannot be overlooked. However, the combined pollution resulting from CUPs and MPs in greenhouse soil remains poorly understood. In this study, we conducted a survey at 30 greenhouse sites in the Wuqing District of Tianjin, China, to investigate the pollution levels and characteristics of CUPs and MPs using QuEChERS combined with LC-MS/MS, and density extraction, 30% H2O2 digestion and micro-fourier transform infrared spectroscopy, respectively. Additionally, we aimed to evaluate the interactions among these two pollutants, soil physicochemical properties, and the bacterial community in the soil. CUPs were frequently detected in the examined soil samples; however, they posed no significant ecological risks due to their low levels. Furthermore, MPs, which predominantly comprised fragmented and fibrous polyethylene (PE) and polypropylene (PP) particles smaller than 1.0 mm, could potentially degrade into nanoplastics, which might subsequently enter the food chain and pose a serious threat to human health. We observed no substantial correlations between CUPs and MPs, except for a negative correlation between dimethomorph and film MPs. The soil pH and total organic carbon (TOC) exhibited interactions with both types of pollutants, whereas soil clay content (CC) only correlated with CUPs, and soil available nitrogen (AN) only correlated with MPs. The variability of soil bacterial communities among the 30 sampling sites was minimal, with the dominant genus being Bacillus. Soil pH, TOC, and CC collectively exerted a strong influence on the microbial community across all samples; however, the effects of CUPs and MPs on the soil microbial structure were marginal. These results contribute to a comprehensive understanding of the environmental stress and ecological risks associated with the combined pollution of CUPs and MPs.

Effect of microplastics on the degradation of tetracycline in a soil microbial electric field

The degradation of organic pollutants and the adsorption of organic pollutants onto microplastics (MPs) in the environment have recently been intensively studied, but the effects of biocurrents, which are widespread in various soil environments, on the environmental behavior of MPs and antibiotic pollutants have not been reported. In this study, it was found that polylactic acid (PLA) and polyvinyl chloride (PVC) MPs accelerated the mineralization of humic substances in microbial electrochemical systems (MESs). After tetracycline (TC) was introduced into the MESs, the internal resistance of the soil MESs decreased. Additionally, the presence of MPs enhanced the charge output of the soil MESs by 40% (PLA+TC) and 18% (PVC+TC) compared with a control group without MPs (424 C). The loss in MP mass decreased after TC was added, suggesting a promotion of TC degradation rather than MP degradation for charge output. MPs altered the distribution of the highest occupied molecular orbitals and lowest unoccupied molecular orbitals of TC molecules and reduced the energy barrier for the TC hydrolysis reaction. The microbial community of the plastisphere exhibited a greater ability to degrade xenobiotics than the soil microbial community, indicating that MPs were hotspots for TC degradation. This study provides the first glimpse into the influence of MPs on the degradation of TC in MESs, laying a theoretical and methodological foundation for the systematic evaluation of the potential risks of environmental pollutants in the future.

[Applications and challenges of large language models in critical care medicine]

The rapid development of big data methods and technologies has provided more and more new ideas and methods for clinical diagnosis and treatment. The emergence of large language models (LLM) has made it possible for human-computer interactive dialogues and applications in complex medical scenarios. Critical care medicine is a process of continuous dynamic targeted treatment. The huge data generated in this process needs to be integrated and optimized through models for clinical application, interaction in teaching simulation, and assistance in scientific research. Using the LLM represented by generative pre-trained transformer ChatGPT can initially realize the application in the diagnosis of severe diseases, the prediction of death risk and the management of medical records. At the same time, the time and space limitations, illusions and ethical and moral issues of ChatGPT emerged as the times require. In the future, it is undeniable that it may play a huge role in the diagnosis and treatment of critical care medicine, but the current application should be combined with more clinical knowledge reserves of critical care medicine to carefully judge its conclusions.

Mitigation effects and microbial mechanism of two ecological earthworms on the uptake of chlortetracycline and antibiotic resistance genes in lettuce

The contamination of greenhouse vegetable soils with antibiotics and antibiotic resistance genes (ARGs), caused by the application of livestock and poultry manure, is a prominent environmental problem. In this study, the effects of two ecological earthworms (endogeic Metaphire guillelmi and epigeic Eisenia fetida) on the accumulation and transfer of chlortetracycline (CTC) and ARGs in a soil-lettuce system were studied via pot experiments. The results revealed that earthworm application accelerated the removal of the CTC from the soil and lettuce roots and leaves, with the CTC content reducing by 11.7-22.8 %, 15.7-36.1 %, and 8.93-19.6 % compared with that of the control, respectively. Both earthworms significantly reduced the CTC uptake by lettuce roots from the soil (P < 0.05) but did not change the CTC transfer efficiency from the roots to leaves. The high-throughput quantitative PCR results showed that the relative abundance of ARGs in the soil and lettuce roots and leaves decreased by 22.4-27.0 %, 25.1-44.1 %, and 24.4-25.4 %, respectively, with the application of earthworms. Earthworm addition decreased the interspecific bacterial interactions and the relative abundance of mobile genetic elements (MGEs), which helped reduce the dissemination of ARGs. Furthermore, some indigenous soil antibiotic degraders (Pseudomonas, Flavobacterium, Sphingobium, and Microbacterium) were stimulated by the earthworms. The results of redundancy analysis indicated that the bacterial community composition, CTC residues, and MGEs were the main parameters affecting the distribution of ARGs, accounting for 91.1 % of the total distribution. In addition, the bacterial function prediction results showed that the addition of earthworms reduced the abundance of some pathogenic bacteria in the system. Overall, our findings imply that earthworm application can substantially reduce the accumulation and transmission risk of antibiotics and ARGs in soil-lettuce systems, providing a cost-effective soil bioremediation practice for addressing antibiotic and ARGs contamination to guarantee the safety of vegetables and human health.

Foliar cadmium uptake, transfer, and redistribution in Chili: A comparison of foliar and root uptake, metabolomic, and contribution

Atmospheric deposition is an essential cadmium (Cd) pollution source in agricultural ecosystems, entering crops via roots and leaves. In this study, atmospherically deposited Cd was simulated using cadmium sulfide nanoparticles (CdS_N), and chili (Capsicum frutescens L.) was used to conduct a comparative foliar and root experiment. Root and foliar uptake significantly increased the Cd content of chili tissues as well as the subcellular Cd content. Scanning electron microscopy and high-resolution secondary ion mass spectrometry showed that Cd that entered the leaves via stomata was fixed in leaf cells, and the rest was mainly through phloem transport to the other organs. In leaf, stem, and root cell walls, Cd signal intensities were 47.4%, 72.2%, and 90.0%, respectively. Foliar Cd uptake significantly downregulated purine metabolism in leaves, whereas root Cd uptake inhibited stilbenoid, diarylheptanoid, and gingerol biosynthesis in roots. Root uptake contributed 90.4% Cd in fruits under simultaneous root and foliar uptake conditions attributed to xylem and phloem involvement in Cd translocation. Moreover, root uptake had a more significant effect on fruit metabolic pathways than foliar uptake. These findings are critical for choosing pollution control technologies and ensuring food security.

Microplastics degradation stimulated by in-situ bioelectric field in agricultural soils

Bioelectric field is a stimulated force to degrade xenobiotic pollutants in soils. However, the effect of bioelectric field on microplastics (MPs) aging is unclear. The degradation behavior of polyvinyl chloride (PVC), polyethylene (PE) and polylactic acid (PLA) was investigated in an agricultural soil microbial electrochemical system in which bioelectric field was generated in-situ by native microbes. Based on the density function theory, the energy gaps between the highest and the lowest occupied molecular orbitals of the three polymers with periodic structure were 4.20, 7.24 and 10.09 eV respectively, and further decreased under the electric field, indicating the higher hydrolysis potential of PLA. Meanwhile, the mass loss of PLA in the closed-circuit group (CC) was the highest on day 120, reaching 8.94%, which was 3.01-3.54 times of that without bioelectric field stimulation. This was mainly due to the enrichment of plastic-degrading bacteria and a robust co-occurrence network as the deterministic assembly process, e.g., the abundance of potential plastic-degrading bacteria on the surface of PLA and PVC in the CC increased by 1.92 and 1.30 times, respectively, compared to the open-circuit group. In terms of functional genes, the xenobiotic biodegradation and metabolism capacity of plasticsphere in the CC were stronger than that in soil, and determined by the bioaccessibility of soil nitrogen and carbon. Overall, this study explored the promoting effect of bioelectric field on the degradation of MPs and reveled the mechanism from quantum chemical calculations and microbial community analysis, which provides a novel perception to the in-situ degradation of MPs.

Carbon sequestration in paddy soils: Contribution and mechanisms of mineral-associated SOC formation

In this work, comparative study of paddy and upland soils were carried out to unravel mechanisms of enhanced soil organic carbon (SOC) sequestration in paddy soils using fractionation methods, ¹³C NMR and Nano-SIMS analysis, as well as organic layer thickness calculations (Core-Shell model). The results showed that although there is a strong increase in particulate SOC in paddy soils compared to that in the upland soils, the increase in mineral-associated SOC is more important, explaining 60-75% of SOC increase in the paddy soils. In the wet and dry alternate cycles of paddy soil, iron (hydr)oxides adsorb relatively small and soluble organic molecules (fulvic acid-like), promote catalytic oxidation and polymerization, thus accelerating formation of larger organic molecules. Upon reductive iron dissolution, these molecules are released and incorporated into existing less soluble organic compounds (humic acid or humin-like), which are coagulated and associated with clay minerals, becoming part of the mineral-associated SOC. The functioning of this "iron wheel" process stimulates accumulation of relatively young SOC into mineral-associated organic carbon pool, and reduces the difference in chemical structure between oxides-bound and clay-bound SOC. Further, the faster turnover of oxides and soil aggregates in paddy soil also facilities interaction between SOC and minerals. The formation of mineral-associated SOC may delay degradation of organic matter during both wet and dry period in the paddy field, therefore enhancing carbon sequestration in paddy soils.

Enhanced cadmium removal by biochar and iron oxides composite: Material interactions and pore structure

The combination of biochar (BC) and iron minerals improves their pollutant adsorption capacity. However, little is known about the reactivity of BC-iron mineral composites regarding their interaction and change in the pore structure. In this study, the mechanism of cadmium (Cd) adsorption by BC-iron oxide composites, such as BC combined with ferrihydrite (FH) or goethite (GT), was explored. The synergistic effect of the BC-FH composite significantly improved its Cd adsorption capacity. The adsorption efficiencies of BC-FH and BC-GT increased by 15.0% and 10.8%, respectively, compared with that of uncombined BC, FH, and GT. The strong Cd adsorption by BC-FH was attributed to stable interactions and stereoscopic pore filling between BC and FH. The scanning electron microscopy results showed that FH particles entered the BC pores, whereas GT particles were loaded onto the BC surface. FTIR spectroscopy showed that GT covered a larger area of the BC surface than FH. After loading FH and GT, BC porosities decreased by 9.3% and 4.1%, respectively. Quantum chemical calculations and independent gradient mode analysis showed that van der Waals interactions, H-bonds, and covalent-like interactions maintained stability between iron minerals and BC. Additionally, humic acid increased the agglomeration of iron oxides and formed larger particles, causing additional aggregates to load onto the BC surface instead of entering the BC pores. Our results provide theoretical support to reveal the interfacial behavior of BC-iron mineral composites in soil and provide a reference for field applications of these materials for pollution control and environmental remediation.

Phosphorus-Enhanced and Calcium-Retarded Transport of Ferrihydrite Colloid: Mechanism of Electrostatic Potential Changes Regulated via Adsorption Speciation

The transport of ferrihydrite colloid (FHC) through porous media is influenced by anions (e.g., PO₄^3-) and cations (e.g., Ca²⁺) in the aqueous environment. This study investigated the cotransport of FHC with P and P/Ca in saturated sand columns. The results showed that P adsorption enhanced FHC transport, whereas Ca loaded onto P-FHC retarded FHC transport. Phosphate adsorption provided a negative potential on the FHC, while Ca added to P-FHC led to electrostatic screening, compression of the electric double layer, and formation of Ca₅(PO₄)₃OH followed by heteroaggregation at pH ≥ 6.0. The monodentate and bidentate P surface complexes coexisted, and Ca mainly formed a ternary complex with bidentate P (≡(FeO)₂PO₂Ca). The unprotonation bidentate P at the Stern 1-plane had a considerable negative potential at the Van der Waals molecular surface. Extending the potential effect to the outer layer of FHC, the potential at the Stern 2-plane and zeta potential exhibited a corresponding change, resulting in a change in FHC mobility, which was validated by comparison of experimental results, DFT calculations, and CD-MUSIC models. Our results highlighted the influence of P and Ca on FHC transport and elucidated their interaction mechanisms based on quantum chemistry and colloidal chemical interface reactions.

Identification, validation and biological characterisation of novel glioblastoma tumour microenvironment subtypes: implications for precision immunotherapy

BACKGROUND

New precision medicine therapies are urgently required for glioblastoma (GBM). However, to date, efforts to subtype patients based on molecular profiles have failed to direct treatment strategies. We hypothesised that interrogation of the GBM tumour microenvironment (TME) and identification of novel TME-specific subtypes could inform new precision immunotherapy treatment strategies.

MATERIALS AND METHODS

A refined and validated microenvironment cell population (MCP) counter method was applied to >800 GBM patient tumours (GBM-MCP-counter). Specifically, partition around medoids (PAM) clustering of GBM-MCP-counter scores in the GLIOTRAIN discovery cohort identified three novel patient clusters, uniquely characterised by TME composition, functional orientation markers and immune checkpoint proteins. Validation was carried out in three independent GBM-RNA-seq datasets. Neoantigen, mutational and gene ontology analysis identified mutations and uniquely altered pathways across subtypes. The longitudinal Glioma Longitudinal AnalySiS (GLASS) cohort and three immunotherapy clinical trial cohorts [treatment with neoadjuvant/adjuvant anti-programmed cell death protein 1 (PD-1) or PSVRIPO] were further interrogated to assess subtype alterations between primary and recurrent tumours and to assess the utility of TME classifiers as immunotherapy biomarkers.

RESULTS

TME^High tumours (30%) displayed elevated lymphocyte, myeloid cell immune checkpoint, programmed cell death protein 1 (PD-1) and cytotoxic T-lymphocyte-associated protein 4 transcripts. TME^High/mesenchymal+ patients featured tertiary lymphoid structures. TME^Med (46%) tumours were enriched for endothelial cell gene expression profiles and displayed heterogeneous immune populations. TME^Low (24%) tumours were manifest as an 'immune-desert' group. TME subtype transitions upon recurrence were identified in the longitudinal GLASS cohort. Assessment of GBM immunotherapy trial datasets revealed that TME^High patients receiving neoadjuvant anti-PD-1 had significantly increased overall survival (P = 0.04). Moreover, TME^High patients treated with adjuvant anti-PD-1 or oncolytic virus (PVSRIPO) showed a trend towards improved survival.

CONCLUSIONS

We have established a novel TME-based classification system for application in intracranial malignancies. TME subtypes represent canonical 'termini a quo' (starting points) to support an improved precision immunotherapy treatment approach.

Analysis of sucrose addition on the physicochemical properties of blueberry wine in the main fermentation

Introduction

Harvested blueberries can be processed into wine to extend their shelf life and increase their commercial value. In order to produce fruit wine, external sugar is often added prior to fermentation to increase the final alcohol content to a target of 8-12% (v/v) to meet consumer expectations.

Method

we explore the effect of 8-14% (w/w) sucrose on the physicochemical properties of blueberry wine throughout the main fermentation process. We monitor changes of alcohol content, sugar, color, phenol, acidity, anthocyanin, and odor.

Results and discussion

We notice that sucrose affects the fermentation process and physicochemical composition of the final blueberry wine by fermentation rate, fermentation color and protection of functional substances protection. Additional sucrose extends the total time of fermentation, and increases wine acidity. The color of the wine is also affected, with added sugar darkening and yellowing the final product. Interestingly, the sucrose has a protective effect on anthocyanin levels, although total anthocyanin levels are still substantially reduced following fermentation. Finally, the additional sugar increases accumulation of volatile odor components, particularly alcohols and esters, as measured by an electronic nose. We conclude that an addition of 12% sucrose produces wine with superior physicochemical properties of alcohol, anthocyanin loss and odor relative to other conditions tested and recommend this approach to commercial manufacturers.

Responses of soil microbial communities to concentration gradients of antibiotic residues in typical greenhouse vegetable soils

To explore the responses of soil microbial communities to concentration gradients of antibiotic residues in soil, 32 soil samples were collected from a typical greenhouse vegetable production base in Northern China in 2019. The total concentrations of 26 antibiotic residues in these soil samples was 83.24-4237.93 μg·kg^-1, of which metabolites of tetracyclines were 23.34-1798.80 μg·kg^-1. The total concentrations in 32 samples were clustered into three levels (L: <100 μg·kg^-1, M: 100-300 μg·kg^-1, H: >300 μg·kg^-1) to elucidate the impacts of antibiotic residues on the diversity, structure, composition, function and antibiotic resistome of soil microbial community. Results showed that higher concentration of antibiotic residues in soil was prone to decrease the diversity and shift the structure and composition of soil microbial community. Antibiotic resistome occurred in soils with antibiotic residues exceeding 300 μg·kg^-1. Interactions among soil bacteria followed the order of H > L > M, consistent with the relative abundances of mobile genetic elements. Bacteroidetes and Firmicutes were the top attributors impacting the profile of antibiotics in soil. According to weighted comprehensive pollution index of risk quotient, in 28.1 % of soil samples the residual antibiotics presented high ecological risk, whereas in the rest of soil samples the ecological risk is medium. The results will enrich the database and provide references for antibiotic contamination control in soils of the region and alike.

Fractionation of levofloxacin and ofloxacin during their transport in NOM-goethite: Batch and column studies

Adsorption and transport of levofloxacin (LEV) and ofloxacin (OFL) enantiomers in a matrix containing goethite and natural organic matter (NOM) were investigated using batch and column experiments. In batch studies, competition and enantioselectivity were observed in the adsorption of LEV and OFL. Enantioselectivity upon adsorption was investigated by comparing changes in the enantiomer fraction (EF) (the ratio of LEV to the sum of LEV and OFL remaining in the solution) after and before adsorption. At pH < 7, there was hardly any selectivity in adsorption of OFL and LEV to goethite. At pH > 7, OFL showed a stronger adsorption than LEV to goethite, and this preference remained when NOM samples of Leonardite humic acid (LHA) and Elliott Soil fulvic acid (ESFA) were added. However, when Suwannee River NOM (SRNOM) was added, the preference was reversed, and LEV was adsorbed more strongly. In single systems, the presence of different types of NOM increased adsorption of LEV and OFL, especially LEV. In column studies, preloaded NOM decreased the transport of LEV and OFL through goethite-coated sand. The EF values in the effluent increased with retention time and reached the largest values (0.59-0.72) at around 1.5 pore volume (PV), and then decreased again, reaching a stable value at 5.0-30.0 PV. Both batch and column experiments showed that, fractionation of LEV and OFL occurred during adsorption and transport in the presence of NOM-goethite complexes, which would eventually affect their environmental fate.

Retardation factors in controlling the transport of inorganic, organic, and particulate phosphorus in fluvo-aquic soil

Excessive application of fertilizers has caused a high load of phosphorus (P) in the North China Plain. The fate of P and its effects on aquatic ecosystems depend on its chemical speciation in soils. However, few studies systematically investigated the transport and retardation of different P species in the fluvo-aquic soil. In this study, the transport of inorganic P (orthophosphate, PO₄), organic P (phytic acid, PA) and particulate P (hydroxyapatite nanoparticles, nHAP) in the fluvo-aquic soil were investigated by column experiments, and their retardation from major soil components such as kaolin, CaCO₃, Al₂O₃, and goethite (GT) was also investigated by monitoring breakthrough curves and fitting transport models. The transport of P species in fluvo-aquic soil followed the order of PO₄ > PA > nHAP. A high fraction of increased clay and mineral particle-associated P (P-E) was observed for PO₄ and PA; while significant Ca-associated P (P-Ca) for nHAP. Under the experimental conditions, both CaCO₃ and GT were the most influential factors for PO₄, PA, and nHAP retention. Goethite strongly inhibited PO₄ transport due to its high PO₄ adsorption capacity, while CaCO₃ strongly inhibited PA transport due to its strong association with PA under alkaline conditions. Both CaCO₃ and GT can severely inhibit nHAP transport due to the favorable electrostatic conditions as well as the Ca²⁺ bridging effect. These results indicated that CaCO₃ played a key role in regulating the retention of organic P and particulate P in the calcareous soil, and also suggested the important role of Fe (hydr)oxides in controlling the transport of inorganic P, which could out-compete that of CaCO₃.

Key factors in the adsorption of natural organic matter to metal (hydr)oxides: Fractionation and conformational change

Adsorption of natural organic matter (NOM) to mineral surfaces is an important process determining the environmental fate and biogeochemical cycling of many elements. Natural organic matter consists of a heterogeneous mixture of soft and flexible organic molecules. Upon adsorption, size fractionation may occur, as well as changes in molecular conformation. Although very important, these phenomena have been omitted in existing adsorption models. Filling this gap, a novel framework for NOM adsorption to metal (hydr)oxides is presented. Humic acid (HA) was used as an analog for studying experimentally the NOM adsorption to goethite and its size fractionation as a function of pH, ionic strength, and surface loading. Size fractionation was evaluated for adsorption isotherms collected at pH 4 and 6, showing HA molecules of low molar mass were preferentially adsorbed. This phenomenon was incorporated into the new model. Consistent description of the HA adsorption data over the entire range of pH (3-11), ionic strength (2-100 mM), and surface loading (0.1-3 mg m^-2) indicated that the spatial distribution of HA molecules adsorbed in the interface is a trade-off between maximizing the interaction of the HA ligands with the oxide surface and minimizing the electrostatic repulsion between HA particles as a result of interfacial crowding. Our advanced consistent framework is able to quantify changes in molar mass and molecular conformation, thereby significantly contributing to an improved understanding of the competitive power of HA for interacting on oxides with other adsorbed small organic acids as well as environmentally important oxyanions, such as phosphate, arsenate, and others.

Influence of biocurrent self-generated by indigenous microorganisms on soil quality

The redox process driven by anaerobic respiration is a link between matter conversion and energy exchange in soil biogeochemistry. Microbial extracellular electron transfer forming biocurrents is a force in element cycling and community living in soil. However, the effect of indigenous microorganisms generating biocurrents on soil quality is unclear. We found that soil biocurrent showed little adverse influence on soil pH, cation exchange capacity, and available nitrogen, phosphorus and potassium and deblocked sequestered organic matter (29%). In addition, the bioelectric field derived from biocurrent obviously forced the migration of mineral elements, which was a supplement to the theory of water-salt transport, providing a new perspective on element transport. Moreover, the soil biocurrent directly regulated the availability of Ca and Fe (increase of 7-fold), indicating that electron transfer plays an important role in weathering and mineralization and thus pedogenesis. From a microbial ecology point of view, the soil bacterial richness and diversity were perfectly restored to their original state when the biocurrent stopped; including bacterial functions; although a temporary enrichment of certain species was observed. The above results provide new insights into the interactions between electron transfer and soil quality and confirm the safety of soil bioelectrochemical technology.

Effects of phthalate esters on soil microbial community under different planting patterns in Northern China: Case study of Hebei Province

Soil microorganisms are biological factors involved in the farmland environment. The factors that shape soil microbial communities and how these are influenced by geographic location, planting pattern (open-field or greenhouse), and soil organic pollutants (phthalate esters, PAEs) remain poorly understood at large scales. Using 16 S rRNA gene and ITS sequencing, we characterized the soil microbiota in open-field and greenhouse soils in Hebei Province, China, and correlated their structure and composition to geographic location, planting pattern and PAEs. Compared with geographic location, planting pattern is more decisive for shaping soil microbes and has more significant effects on bacteria, and the effects are shaped by the number and types of core OTUs. PAEs participated in the shaping of soil microbial communities by altering the relative abundances of dominant microorganisms in the two planting patterns, and the effects of PAEs with high K_ow were more significant. PAEs have a greater impact on bacteria than fungi in both planting patterns. Bacteria in the greenhouse soil were sensitive to the 9 kinds of PAEs detected, however in the open-field samples, mainly responded to PAEs with high K_ow and rarely respond to PAEs with low K_ow. DEHP and DBP, as two monomers with the highest concentration, have significant effects on dominant genera of microorganisms under both planting patterns, with inhibiting effect on bacteria and significantly promotion on fungi. Our study clarified the factors that have a substantial impact on soil microorganisms at the provincial scale and the mechanisms involved in shaping soil microbial community structure, as well as the significant impact of PAEs on soil microbial dominant microorganisms.

Insights into behavior and mechanism of tetracycline adsorption on virgin and soil-exposed microplastics

Microplastics (MPs), as vectors of pollutants, have attracted extensive attention because of their environmental effects. However, the adsorption behavior and antibiotic mechanism of environmentally exposed MPs is limited. Here, the adsorption of tetracycline (TC) onto virgin and soil-exposed polylactic acid (PLA), polyvinyl chloride (PVC) and polyethylene (PE) MPs showed that the adsorption capacity of MPs for TC increased after soil exposure, and PLA showed the strongest increase. Soil exposure increased the time to reach equilibrium, and the adsorption rate was controlled by both intraparticle diffusion and membrane diffusion. The isothermal adsorption results of soil-exposed PE and PLA indicated that TC adsorbed on heterogeneous surfaces was affected by the physicochemical adsorption process. The equilibrium absorption capacity of MPs for TC increased by 88% (PLA), 26% (PVC) and 15% (PE) after soil exposure. Soil dissolved organic matter promoted the desorption of TC from MPs, and TC speciation changed with pH. Soil-exposed MPs have the potential to promote TC degradation in solution without the addition of biological inhibitors. Moreover, density functional theory calculations verified that PE and PVC adsorbed TC through physical interactions, while hydrogen bonds were formed on PLA with TC. These results clarified the behavior and mechanisms of TC adsorption on virgin and soil-exposed MPs, which can help in the risk assessment of concomitant pollution of MPs and antibiotics.

Prophylactic Moxibustion in Preventing Postoperative Urinary Retention of Hemorrhoidectomy: A Study Protocol for a Randomized Controlled Trial

Backgrounds

Postoperative urinary retention (POUR) is one of the most common complications after hemorrhoidectomy. The best treatment for POUR is prevention and should be involved in the whole perioperative period. Moxibustion has been used to treat urinary retention for thousands of years, and clinical studies have also proved its effects. We try to carry out a randomized, controlled, prospective study to observe whether prophylactic moxibustion could effectively reduce the incidence of POUR of hemorrhoidectomy in 24 h.

Methods

This study is a single-center, evaluator-blinded, randomized, and controlled trial. Participants who meet the inclusion and exclusion criteria in this RCT will be randomly assigned to either the treatment group (moxibustion) or the control group (tamsulosin hydrochloride) in a 1:1 ratio according to a computer-generated randomization list. Both moxibustion and tamsulosin will be used 1, 10, and 24 h after operation, respectively. The outcomes of occurrence of POUR, time to first urination, catheterization rate, urinary tract infection, length of hospitalization, and adverse effects will be recorded.

Discussion

The findings of the study will help to explore the preventive efficacy of prophylactic moxibustion against POUR of hemorrhoidectomy in 24 h.

Trial Registration

CHiCTR, CHiCTR2000039350, registered 24 October, 2020, http://www.chictr.org.cn/showproj.aspx?proj = 63204.

Uptake of atmospherically deposited cadmium by leaves of vegetables: Subcellular localization by NanoSIMS and potential risks

Atmospherically deposited cadmium (Cd) may accumulate in plants through foliar uptake; however, the foliar uptake, accumulation, and distribution processes of Cd are still under discussion. Atmospherically deposited Cd was simulated using cadmium sulfide (CdS) with various particle sizes and solubility. Water spinach (Ipomoea aquatica Forsk, WS) and pak choi (Brassica chinensis L., PC) leaves were treated with suspensions of CdS nanoparticles (CdS_N), which entered the leaves via the stomata. Cd concentrations of WS and PC leaves treated with 125 mg L^-1 CdS_N reached up to 39.8 and 11.0 mg kg^-1, respectively, which are higher than the critical leaf concentration for toxicity. Slight changes were observed in fresh biomass, photosynthetic parameters, lipid peroxidation, and mineral nutrient uptake. Exposure concentration, rather than particle size or solubility, regulated the foliar uptake and accumulation of Cd. Subcellular and the high-resolution secondary ion mass spectrometry (NanoSIMS) results revealed that Cd was majorly stored in the soluble fraction and cell walls, which is an important Cd detoxification mechanism in leaves. The potential health risks associated with consuming CdS-containing vegetables were highlighted. These findings facilitate a better understanding of the fate of atmospheric Cd in plants, which is critical in ensuring food security.

POS1368 DIVERSITY OF HEMODYNAMIC TYPES IN CONNECTIVE TISSUE DISEASE ASSOCIATED PULMONARY HYPERTENSION: MORE THAN A SUBGROUP OF PULMONARY ARTERIAL HYPERTENSION

Background

Connective tissue disease (CTD) associated pulmonary hypertension (PH) is classified as a subgroup of WHO group 1 PH, also called pulmonary arterial hypertension (PAH). However, not all CTD-PH fit the hemodynamic definition of PAH. This study investigates the diversity of hemodynamical types of CTD-PH, their different clinical characteristics and outcomes.

Objectives

This study investigates the diversity of hemodynamical types of CTD-PH, their different clinical characteristics and outcomes.

Methods

We performed a retrospective cohort study. CTD-PH patients underwent right heart catheterization (RHC) were enrolled and divided into WHO group1 PH, WHO group 2 PH and high output PH (PVR<3WU and PAWP<15mmHg) according to hemodynamic features. Patients with obvious lung diseases, left heart disease and pulmonary embolism were excluded. Baseline characteristics, inflammatory markers, autoantibodies, cardiac function status, echocardiogram parameters, hemodynamics and survival rates were compared.

Results

207 CTD-PH patients were included, including 139 in WHO group 1 PH, 36 in WHO group 2 PH and 32 in high output PH. Incidence of anti-ribonucleoprotein antibody was lower in WHO Group 2 PH. High output PH is less severe, presenting lower NT-proBNP level, better WHO functional class, lower mPAP and PVR, higher cardiac output, and less cardiac remodeling. Among patients with elevated PAWP, combine pre& post-capillary PH had higher mPAP and larger right ventricle diameter. Association of mild to moderate interstitial lung disease didn’t show significant difference in disease characteristics. Short-term survival was significantly worse in WHO group 2 PH, yet 5-year survival rates didn’t differ between groups.

Conclusion

Pre-capillary PH is not the only hemodynamic type of CTD-PH. Different types of CTD-PH present different clinical phenotypes and outcome. Carefully phenotyping PH in CTD-PH patients is important.

Disclosure of Interests

None declared

NOM-mineral interaction: Significance for speciation of cations and anions

In this study, the nano-scale spatial distribution of natural organic matter (NOM) on the surface of iron (hydr)oxides and its relevance to oxyanion (PO₄^3-) and metal cation (Cd²⁺ and Cu²⁺) adsorption to the assemblage of oxide (goethite) and NOM (humic acids (HA) or fulvic acids (FA)) was investigated with experiments and advanced surface complexation modeling. Both the linear additive Multi-Surface model (MSM) and the more sophisticated Natural Organic Matter-Charge Distribution (NOM-CD) model were used. The MSM model ignores the effects of NOM-mineral interaction on ion adsorption, whereas the NOM-CD model considers this effect. The results showed that with the increase of NOM loading on oxides, deviation between the MSM and NOM-CD model became bigger for PO₄^3-, but smaller for Cd²⁺ and Cu²⁺. Oxyanions bind mainly to oxides and therefore the competitive effect of NOM cannot be neglected, which explains the large difference between these two models for PO₄^3-. On the contrary, at a relatively high NOM loading, a large fraction of NOM extends further away from the surface of oxides. Thus for metal cations that bind mainly to NOM, the influence of NOM-mineral interaction on their adsorption is small and the results of the MSM and NOM-CD model are similar. In top soils, the NOM loading on oxides is often high, therefore the linear additive MSM is applicable for metal cation speciation calculations as reported in many literatures. An approach based on the NOM-CD model was proposed, which can not only calculate the macroscopic solid-solution distribution of both cations and anions, but can also provide information regarding their microscopic surface speciation.

Effect of Agricultural Organic Inputs on Nanoplastics Transport in Saturated Goethite-Coated Porous Media: Particle Size Selectivity and Role of Dissolved Organic Matter

The transport of nanoplastics (NPs) through porous media is influenced by dissolved organic matter (DOM) released from agricultural organic inputs. Here, cotransport of NPs with three types of DOM (biochar_DOM (BC_DOM), wheat straw_DOM (WS_DOM), and swine manure_DOM (SM_DOM)) was investigated in saturated goethite (GT)-coated sand columns. The results showed that codeposition of 50 nm NPs (50NPs) with DOM occurred due to the formation of a GT-DOM-50NPs complex, while DOM loaded on GT-coated sand and 400 nm NPs (400NPs) aided 400NPs transport due to electrostatic repulsion. According to the quantum chemical calculation, humic acid and cellulose played a significant role in 50NPs retardation. Owing to its high concentration, moderate humification index (HIX), and cellulose content, SM_DOM exhibited the highest retardation of 50NPs transport and promoting effect on 400NPs transport. Owing to a high HIX, the effect of BC_DOM on the mobility of 400NPs was higher than that of WS_DOM. However, high cellulose content in WS_DOM caused it to exhibit a 50NPs retardation ability that was similar to that of BC_DOM. Our results highlight the particle size selectivity and significant influence of DOM type on the transport of NPs and elucidate their quantum and colloidal chemical-interface mechanisms in a typical agricultural environment.

Effects of selected functional groups on nanoplastics transport in saturated media under diethylhexyl phthalate co-contamination conditions

The production and degradation of plastic remains can result in nanoplastics (NPs) formation. However, insufficient information regarding the environmental behaviors of NPs impedes comprehensive assessment of their significant threats. In this study, the transport behavior of unmodified NPs (PSNPs), carboxyl-modified NPs (PSNPs-COOH), and amino-modified NPs (PSNPs-NH₂) was investigated using column experiments in the presence and absence of goethite (GT) and diethylhexyl phthalate (DEHP). Quantum chemical computation was performed to reveal the transport mechanisms. The results showed that GT decreased the transport of NPs and the presence of DEHP decreased it further. Van der Waals forces and small electrostatic interactions coexisted between the PSNPs and GT and caused deposition. Ligand exchange caused greater deposition of PSNPs-COOH on GT-coated sand than that of PSNPs. Although hydrogen bonding existed between the DEHP and NPs with functional groups, an increase in the positive charge and chemical heterogeneity of the collector was the main reason for DEHP promoting the deposition of NPs. Because of low absolute negative zeta potential values, PSNPs-NH₂ was sensitive to chemical heterogeneity, and thus fully deposited (over 96.9%) in GT and GT-DEHP-coated columns. Generally, the deposition of NPs due to chemical heterogeneity was more significant than that due to the formation of chemical bonds and van der Waals, electrostatic, and hydrogen interactions. Our results highlight that the surface charge and functional groups significantly influence the transport behaviors of NPs and elucidate the fate of NPs in the terrestrial environment.

Exposure to fomesafen alters the gut microbiota and the physiology of the earthworm Pheretima guillelmi

The application of herbicide fomesafen plays a crucial role in ensuring global soybean productivity in modern agriculture, but it results in both adverse effects on soil ecosystems and phytotoxicity to succeeding crops. Soil pollution due to herbicides has raised much concern worldwide. However, there has been little investigations concerning their effects on soil fauna, especially on the gut microbial communities of earthworms. In this study, the soil endogeic earthworm Pheretima guillelmi was incubated for 20 days in natural and fomesafen-polluted soils to investigate the effects of the herbicide on gut bacterial microbiota and the earthworm's physiological indices, including energy resource (protein) and antioxidant enzyme (superoxide dismutase, SOD) of earthworms in the soil ecosystem. A significantly different and smaller microbial community was presented in the earthworm's gut compared with the cast and the surrounding soil, with exposure to fomesafen further reducing the bacterial diversity and altering the gut community composition. This was observed as significant changes in the relative abundance of the phyla Actinobacteria, Firmicutes, and Proteobacteria as well as the genera Bacillus, Microvirga, Blastococcus, Nocardioides, and Gaiella. Moreover, exposure to fomesafen reduced earthworms' energy resources and activated the antioxidant system, with both effects being significantly correlated with the gut microbial diversity. These findings unravel the fact that exposure to the herbicide fomesafen may affect non-target soil fauna via changes in their microbiota and physiological indices, thereby contributing new knowledge regarding the adverse impacts of fomesafen on the terrestrial ecosystem.

Arsenic and cadmium load in rice tissues cultivated in calcium enriched biochar amended paddy soil

Arsenic (As) and cadmium (Cd) are unnecessary metal(loids) toxic at high concentration to plants and humans, hence lessening their rice grain accumulation is crucial for food security and human healthiness. Charred eggshell (EB), corncob biochar (CB), and eggshell-corncob biochar (ECB) were produced and amended to As and Cd co-polluted paddy soil at 1% and 2% application rates to alleviate the metal(loids) contents in rice grains using pot experiments. All the amendments increased paddy yields at 1%, while EB at 2% significantly reduced the yields compared to untreated control. The resulting yield loss in 2%EB was from the combined effects of its high CaCO₃ supplementation, and the increment of rhizosphere soil pH which could insolubilize plant nutrients. The amendments were inefficient in decreasing rice grain As (As_Grain), but all the treatments significantly reduced the rice grain Cd (Cd_Grain) at both 1% (44.4-77.1%) and 2% (79.8-91.5%) application rates compared to that of control. Regression analysis for contribution weights of control factors revealed that rhizosphere soil Eh and pH were vital influential factors regulating the As_Grain, whereas porewater Cd was main factor controlling Cd_Grain accumulation. These investigations indicated that the Ca-enriched eggshell-corncob biochar even at high application rate (i.e., 2%ECB) could be a potential tactic for grain accumulation remediation of the cationic pollutant (i.e., Cd) from the paddy soil to rice grain scheme with concurrent increase in rice yields.

Competitive adsorption of Dibutyl phthalate (DBP) and Di(2-ethylhexyl) phthalate (DEHP) onto fresh and oxidized corncob biochar

Phthalates (PAEs) often exist simultaneously in contaminated soil and wastewater systems, and their adsorption to biochar might impact their behavior in the environment. So far, the competitive adsorption of PAEs to biochar has not been reported. In this study, the competitive adsorption of Dibutyl phthalate (DBP) and Di(2-ethylhexyl) phthalate (DEHP) on corncob biochar (fresh and oxidized) was investigated, and experiments of kinetics, isotherms, and thermodynamics were conducted. Langmuir and Freundlich models, pseudo-first-order and second-order kinetic models were used to simulate the experimental data. In the mono PAEs component systems, the biochar showed significantly greater adsorption capacity for DEHP (11.8-16.16 mg g^-1) than for DBP (9.86-13.2 mg g^-1). The oxidized biochar has higher adsorption capacities than the fresh one. Moreover, a fast adsorption rate for DBP was observed, which can be attributed to the smaller size and shorter carbon chains in the DBP molecule, resulting in faster diffusion into the biochar pores. In the binary PAEs component systems, competition between DEHP and DBP in their adsorption to the biochars was observed, and DEHP (11.7-15.0 mg g^-1) was preferred over DBP (3.4-7.9 mg g^-1). The stronger adsorption of DEHP can be explained by stronger hydrophobic interaction with biochar. Compared to DBP, DEHP has a high octanol-water partition coefficient (logK_ow) and low water solubility. The positive entropy (ΔS⁰) and enthalpy(ΔH⁰) values for the adsorption of both DEHP and DBP further indicated that hydrophobic interaction played an important role, even though H-bonds and π-π interactions could also be involved.

Comparison of the effects of large-grained and nano-sized biochar, ferrihydrite, and complexes thereof on Cd and As in a contaminated soil-plant system

Cd and As are difficult to co-remediate in co-contaminated soils. In this study, remediation materials comprising large-grained and nano-sized biochar (BC), ferrihydrite (FH), and complexes thereof were added to Cd- and As-contaminated soil. The uptake of Cd and As by pak choi (Brassica chinensis L.) was then evaluated using a pot experiment and the Cd and As concentrations of the soil pore water and leaching water were measured. The Cd and As concentrations of the pore and leaching water were slightly increased with the addition of BC, and decreased with addition of FH and the biochar-ferrihydrite complex (BC-FH). However, nano-sized BC (BC_N), FH (FH_N), and BC-FH (BC-FH_N) had little influence on the decreases in Cd and As of the two monitored water types. Large-grained remediation materials, rather than nanomaterials, decreased the Cd and As concentrations of the two monitored water types. Nonetheless, nanomaterial treatments more effectively decreased the Cd and As concentrations in plants by an average of >10% relative to the large-grained treatments. The DLVO theory analysis suggested that BC_N, FH_N, and BC-FH_N, immobilized in the topsoil, adsorbed heavy metals in the rhizosphere soil. The remainder of the nano-sized materials was dispersed in the rhizosphere soil pores, shielding the uptake of Cd and As by the roots. Although the doses of nanomaterials used in this study were less than one-fortieth of those of the large-grained materials, changes in the plant rhizosphere microenvironment caused by the nanomaterials decreased the risk of toxicity transfer from the soil to the plants.

Effect of calcium and iron-enriched biochar on arsenic and cadmium accumulation from soil to rice paddy tissues

Arsenic (As) and cadmium (Cd) are nonessential toxic metal(loids) that are carcinogenic to humans. Hence, reducing the bioavailability of these metal(loids) in soils and decreasing their accumulation in rice grains is essential for agroecology, food safety, and human health. Iron (Fe)-enriched corncob biochar (FCB), Fe-enriched charred eggshell (FEB), and Fe-enriched corncob-eggshell biochar (FCEB) were prepared for soil amelioration. The amendment materials were applied at 1% and 2% application rates to observe their alleviation effects on As and Cd loads in rice paddy tissues and yield improvements using pot trials. The FCEB treatment increased paddy yields compared to those of FCB (9-12%) and FEB (3-36%); this could be because it contains more plant essential nutrients than FCB and a lower calcite content than that of FEB. In addition, FCEB significantly reduced brown rice As (As_BR, 29-60%) and Cd (Cd_BR, 57-81%) contents compared to those of the untreated control (CON). At a 2% application rate, FCEB reduced the average mobility of As (56%) and Cd (62%) in rhizosphere porewater and enhanced root Fe-plaque formation (76%) compared to those of CON. Moreover, the enhanced Fe-plaque sequestered a substantial amount of As (171.4%) and Cd (90.8%) in the 2% FCEB amendment compared to that of CON. Pearson correlation coefficients and regression analysis indicated that two key mechanisms likely control As_BR and Cd_BR accumulations. First, rhizosphere soil pH and Eh controlled As and Cd availabilities in porewaters and their speciation in the soil. Second, greater Fe-plaque formation in paddy roots grown in the amended soils provided a barrier for plant uptake of the metal(loids). These observations demonstrate that soil amendment with Fe-enriched corncob-eggshell biochar (e.g., 2% FCEB) is a prospective approach for the remediation of metal accumulation from the soil to grain system while simultaneously increasing paddy yield.

Enhanced adsorption of polystyrene nanoplastics (PSNPs) onto oxidized corncob biochar with high pyrolysis temperature

Plastic pollution has become a global threat in the natural environment, and an urgent remedial measure is needed to reduce the negative effects caused by plastic pollutants. In the current study, the effects of pyrolysis temperature (500 °C, 700 °C, and 900 °C) and aging on the adsorption of polystyrene nanoplastics (PSNPs) onto corncob biochar were systematically assessed with kinetic, isotherm, pH-dependent adsorption experiments, FTIR and XPS spectroscopy, and DLVO calculations. The oxidation was done with 5% of HNO₃/H₂SO₄ to simulate long-term oxidative aging of biochar in the environment. The results showed that the specific surface area, hydrophobicity, and aromaticity of biochar increased with pyrolysis temperature, whereas the specific surface area and amounts of oxygen-containing groups increased after oxidation. The adsorption mechanism of PSNPs onto the biochar was explored based on the correlation between biochar properties and adsorption parameters derived from adsorption isotherms. Overall, the adsorption capacity of biochar for PSNPs increased with increased pyrolysis temperature and after aging. While the increase of specific surface area was considered the major factor leading to the increase of the adsorption, the variation in surface properties also played an important role. Pore filling, hydrophobic interaction, and hydrogen bonding may all be involved in PSNPs adsorption to biochar. However, the hydrophobic interaction might be more important for the fresh biochar, whereas hydrogen bonding involving oxygen-containing groups might make a bigger contribution to PSNPs adsorption to oxidized biochar. The pH experiments revealed that PSNPs adsorption decreased in general with the increase of pH, indicating that electrostatic repulsion played a vital role in the PSNPs adsorption process. The results of this study indicate that biochar can be potentially applied to immobilize plastic particles in terrestrial ecosystems such as in soil or groundwater, and the immobilization could be enhanced via artificial oxidation or aging of biochar in the natural environment.

Combining multisurface model and Gouy-Chapman-Stern model to predict cadmium uptake by cabbage (Brassica Chinensis L.) in soils

Cadmium is an extremely toxic substance known to cause serious health problems. The uptake of Cd in plants is critically affected by dissolved Cd in soil porewater, controlled by soil physicochemical properties. Rhizo-availability of Cd is assumed, as the Cd fraction is found on the plasma membrane of surface root cells. Based on the theory of Cd transformation in soil-crop systems, we established a novel combined mechanistic model related to soil, soil solutions, and crops. The combined model comprises a multisurface model (MSMs; solid adsorbent and porewater) and the Gouy-Chapman-Stern model (GCS; porewater and root surface). The results suggested that in mildly contaminated soil samples, optimum prediction was achieved when DTPA-extractable Cd was used as input variable (R² = 0.723). Our approach was superior to single-step model calculation (MSMs: R² = 0.613; GCS: R² = 0.629) and prediction based on extractable soil Cd (R² = 0.281). Introducing DTPA extraction expanded the range of model applications at different soil pHs. Our proposed mechanism model was based on soil physicochemical properties for Cd migration from soil to cabbage. Our model showed promise in predicting Cd bioavailability in soil with a wide pH range and evaluating soil risk near the standard Cd safety level.

Removal of chlortetracycline and antibiotic resistance genes in soil by earthworms (epigeic Eisenia fetida and endogeic Metaphire guillelmi)

The impacts of two ecological earthworms on the removal of chlortetracycline (CTC, 0.5 and 15 mg kg^-1) and antibiotic resistance genes (ARGs) in soil were explored through the soil column experiments. The findings showed that earthworm could significantly accelerate the degradation of CTC and its metabolites (ECTC) in soil (P < 0.05), with epigeic Eisenia fetida promoting degradation rapidly and endogeic Metaphire guillelmi exhibiting a slightly better elimination effect. Earthworms alleviated the abundances of tetR, tetD, tetPB, tetG, tetA, sul1, TnpA, ttgB and intI1 in soil, with the total relative abundances of ARGs decreasing by 35.0-44.2% in earthworm treatments at the 28th day of cultivation. High throughput sequencing results displayed that the structure of soil bacteria community was modified apparently with earthworm added, and some possible CTC degraders, Aeromonas, Flavobacterium and Luteolibacter, were promoted by two kinds of earthworms. Redundancy analysis demonstrated that the reduction of CTC residues, Actinobacteria, Acidobacteria and Gemmatimonadetes owing to earthworm stimulation was responsible for the removal of ARGs and intI1 in soil. Additionally, intI1 declined obviously in earthworm treatments, which could weaken the risk of horizontal transmission of ARGs. Therefore, earthworm could restore the CTC-contaminated soil via enhancing the removal of CTC, its metabolites and ARGs.

Phosphorus transport in different soil types and the contribution of control factors to phosphorus retardation

Iron (Fe) minerals, organic matter (OM), and pH can effectively regulate phosphorus (P) transport in the soil. However, their respective contributions in this regard are still unclear. In this study, P transport in soil columns was investigated by monitoring breakthrough curves and transport model fitting, and the contributions of Fe and total organic carbon (TOC) concentrations, as well as pH to P retention, were determined using multiple linear regression (MLR). The results showed that the rate of P transport in Fe-rich laterite soil was significantly lower (retardation factor R = 458.5) than that in the other soil types (R = 108.4-247.6). Additionally, it was observed that OM formed rate-limited adsorption sites, causing the rapid release of labile P, and owing to P release and readsorption. Even though more significant P releases were observed, chernozem soil had an obvious inhibiting effect on P transport owing to its relatively high Fe content, and the high P-Fe increment (48.9-90.4%) indicated the essential role of Fe minerals in P immobilization. Further, P was readily transported in natural or artificially modified fluvo-aquic soils with high calcium concentrations, and it was also observed that the convection-dispersion equation (CDE) and Thomas models were suitable for describing P retardation and adsorption, respectively. Furthermore, the contribution weights of Fe and TOC concentrations as well as pH to P retardation, based on MLR calculations, were approximately 1.0, -0.3, and -0.2, respectively. Our findings can support the control of eutrophication pollution caused by P leaching.

Contamination and human health risks of phthalate esters in vegetable and crop soils from the Huang-Huai-Hai region of China

The widespread presence of phthalate esters (PAEs) in a variety of agricultural inputs has led to PAE contamination in soils and farm products. The endocrine disruption and carcinogenicity of PAEs have attracted much attention. Our research investigated the characteristics of PAE pollution in the soils of vegetable fields and adjacent stable crop fields in four provinces/municipalities across a major agricultural production area in China. We found that the concentrations of PAEs in vegetable soils were not significantly higher than those in stable crop soils. The noncarcinogenic and carcinogenic risks from bis (2-ethylhexyl) phthalate (DEHP) and dibutyl phthalate (DBP) to humans were calculated to represent the risk posed by PAEs. The results showed that diet was the main route for noncarcinogenic risks from PAEs in crop soil and vegetable soils. Because of the combined effect of the population dietary structure and the concentration of PAEs in soils, the noncarcinogenic risks from PAEs in crop soils were similar to or higher than those in vegetable soils. The same pattern was also applicable to the carcinogenic risk from DEHP. Low noncarcinogenic and carcinogenic risks posed by DEHP and DBP indicated that the current level of PAEs in soils did not decrease the safety of agricultural products in the Huang-Huai-Hai region. Stable crop soil, as a non-negligibly phthalate-polluted area, is worthy of as much attention as vegetable soil. This study provides scientific support for food safety risk assessment and control of PAE pollution in the main agricultural production areas in China.

Temporal and spatial variability of antibiotics in agricultural soils from Huang-Huai-Hai Plain, northern China

The objective of this study was to investigate the temporal and spatial distribution of antibiotics in agricultural soils of Huang-Huai-Hai Plain, which is a major agricultural producing area and economically developed region in China. In this study, 105 soil samples including 13 groups of soil profile samples (0-20, 20-40 and 40-60 cm) and 23 paired surface soil samples of greenhouse and open-field were collected from four provinces/municipality in 2018. The occurrence of 20 antibiotics, including four tetracyclines (TCs), seven quinolones (QNs), six sulfonamides (SAs) and three macrolides (MLs) were measured. The concentrations of total antibiotics fell in the range of 1.62-575 μg kg^-1, with the mean value of 68.8 μg kg^-1. TCs and QNs were dominant antibiotics in soil, accounting for 99.6% of the total concentration. Regional differences of antibiotic residues in soil were found among the four regions as well as between different cropping systems. The levels of antibiotics in greenhouse soils (3.52-575 μg kg^-1) were higher than those in open-field soils (1.62-142 μg kg^-1). In soils of greenhouse of 1-6 years old, the levels of antibiotics were higher than those with longer history (7-30 years). Antibiotics were mainly distributed in the depth of 0-20 cm. The total concentrations of antibiotics/QNs followed the order of 0-20 cm > 40-60 cm > 20-40 cm, due to probably their interactions with total organic carbon and associated bacterial communities. The results in the study will provide data supports for the formulation of soil antibiotic contamination prevention and control measures.

Worenine reverses the Warburg effect and inhibits colon cancer cell growth by negatively regulating HIF-1α

Background

Some natural compounds inhibit cancer cell growth in various cancer cell lines with fewer side effects than traditional chemotherapy. Here, we explore the pharmacological effects and mechanisms of worenine (isolated from Coptis chinensis) against colorectal cancer.

Methods

The effects of worenine on colorectal cancer cell proliferation, colony formation and cell cycle distribution were measured. Glycolysis was investigated by examining glucose uptake and consumption, lactate production, and the activities and expressions of glycolysis enzymes (PFK-L, HK2 and PKM2). HIF-1α was knocked down and stimulated in vitro to investigate the underlying mechanisms.

Results

Worenine somewhat altered the glucose metabolism and glycolysis (Warburg effect) of cancer cells. Its anti-cancer effects and capability to reverse the Warburg effect were similar to those of HIF-1α siRNA and weakened by deferoxamine (an HIF-1α agonist).

Conclusion

It is suggested that worenine targets HIF-1α to inhibit colorectal cancer cell growth, proliferation, cell cycle progression and the Warburg effect.

Supplementary Information

The online version contains supplementary material available at 10.1186/s11658-021-00263-y.

Advances in the Treatment of Anal Fistula: A Mini-Review of Recent Five-Year Clinical Studies

Anal fistula, with its complicated pathogenesis, has been considered as a clinical challenge for centuries. The risk of frequent recurrence and incontinence constitutes a considerable threat in the long-term treatment of anal fistula. In this work, we narratively reviewed the scientific literature of new techniques that have been used for anal fistula treatment over the recent 5 years, objectively evaluated the pros and cons of each technique on the basis of clinical outcomes, and tried to disclose the effective strategies for anal fistula treatment. Up to date, surgery is the main method used for treating anal fistula, but there is no simple technique that can completely heal complex anal fistula. In the course of surgery treatment, the healing outcome, and the protection of anal function should be weighed comprehensively. Among the innovative techniques that have emerged in recent years, combined techniques based on drainage Seton and LIFT-plug seem to be the relatively effective therapies, but their effectiveness requires more multi-center prospective randomized controlled trials with large sample size and long-term follow-up to be validated.

Watering techniques and zero-valent iron biochar pH effects on As and Cd concentrations in rice rhizosphere soils, tissues and yield

Zero-valent iron amended biochar (ZVIB) has been proposed as a promising material in immobilizing heavy metals in paddy fields. In this study, the impacts of pH of ZVIB (pH 6.3 and pH 9.7) and watering management techniques (watering amount in the order of CON (control, 5/72)>3/72>1-3/72>3/100>1/72, with 5/72, for example, representing irrigation given to 5 cm above soil surface in 72 hr regular interval) on As and Cd bioavailability for rice and its grain yield (Yield_BR) were investigated in a pot experiment. Brown rice As (As_BR) content was irrelative to the watering treatments, while significantly decreased (>50%) with the addition of both ZVIB materials. The diminutions of brown rice Cd (Cd_BR) content as well as the Yield_BR were highly dependent on both the soil amendment materials' pH and watering amount. Among all the watering treatments, 3/72 treatment (15% less irrigation water than the CON) with ZVIB 6.3 amendment was the optimum fit for simultaneous reduction of As_BR (50%) and Cd_BR contents (19%) as well as for significant increment (12%) of the Yield_BR. Although high pH (9.7) ZVIB application could also efficiently decrease As and Cd contents in brown rice, it might risk grain yield lost if appropriate (e.g. 3/72 in our study) watering management technique was not chosen. Therefore, ZVIB would be an environmentally friendly option as an amendment material with proper selection of watering management technique to utilize As and Cd co-contaminated arable soils safely for paddy cultivation.

Hetero-aggregation of goethite and ferrihydrite nanoparticles controlled by goethite nanoparticles with elongated morphology

The dispersities of goethite nanoparticles (GTNPs) and ferrihydrite nanoparticles (FHNPs) affect the transport and retention of nanoparticle-associated contaminants. However, the effects of interaction on nanoparticle stability under varying environmental conditions have not been previously investigated. This study utilized settling experiments, a semi-empirical model, and the Derjaguin-Landau-Verwey-Overbeek (DLVO) theory to study the homo-aggregation and hetero-aggregation of GTNPs and FHNPs. The pure system of GTNPs tended to aggregate more easily than that of FHNPs, especially under the conditions of high pH (7.0-9.0), high ionic strength (IS, 10 mM), and low concentrations of humic acid (HA) (2 mg L^-1). This aggregation was attributed to the elongated morphology of GTNPs, which contributed to surface heterogeneity. The GTNPs and FHNPs mixtures rapidly coagulated, particularly under the surface-charge disequilibrium caused by an increase in negative charges or IS. Hetero-aggregation increased with increase in the GTNPs ratio, indicating that the elongated GTNPs dominated the coagulation of the Fe mineral nanoparticle mixture, which was attributed to the surface heterogeneity and high probability collisions between the GTNPs. Although DLVO neglects the influence of heterogeneity on the nanoparticle surfaces, SEM revealed that hetero-aggregation of GTNPs and FHNPs occurred. The results obtained in this study provide novel and valuable insights into the behaviors of GTNPs and FHNPs mixtures and suggest that during the gradual transformation of FHNPs to GTNPs in soil or aquatic environments, the hetero-aggregation of GTNPs and FHNPs may be enhanced, thus promoting contaminant immobilization.

Tissue selecting technique mega-window stapler combined with anal canal epithelial preservation operation for the treatment of severe prolapsed hemorrhoids: A study protocol for a randomized controlled trial

INTRODUCTION

Hemorrhoidal disease is one of the most common and frequently occurring benign anorectal disorders, presented with bleeding and prolapsed, and surgery is the main and effective method for severe prolapsed hemorrhoids. Yet, the recurrence rate after procedure for prolapse and hemorrhoids (PPH) is significantly higher. To reduce the recurrence rate and protect the anus function, we try to carry out a randomized, controlled, prospective study to compare the efficacy and recurrence rate of tissue selecting technique (TST) with mega-window stapler (TST-MS) combined with anal canal epithelial preservation operation and PPH combined with external hemorrhoidectomy and inferior internal hemorrhoid ligation operation for the treatment of severe prolapsed hemorrhoids.

METHODS

This study is a single-center, evaluator-blinded, randomized, controlled clinical trial. Participants meet the inclusion and exclusion criteria in this RCT will be randomly divided into treatment group (TST-MS combined with anal canal epithelial preservation operation group) and control group (PPH combined with external hemorrhoidectomy and inferior internal hemorrhoid ligation operation) in a 1:1 ratio according to a computer-generated randomization list. The outcomes of recurrence, anal function, intraoperative variables, and postoperative complications will be recorded at different follow-ups.

CONCLUSION

The findings of the study will help to explore the efficacy and recurrence rate of TST-MS combined with anal canal epithelial preservation operation on the treatment of severe prolapsed hemorrhoids.

TRIAL REGISTRATION

This study protocol was registered in open science framework (OSF). (Registration number: DOI 10.17605 / OSF.IO / 4JYNF).

Comparative study on the pollution status of organochlorine pesticides (OCPs) and bacterial community diversity and structure between plastic shed and open-field soils from northern China

The pollution status of organochlorine pesticides (OCPs) and microbial community in plastic shed and open-field soils may be different due to the significant variations in environmental factors between the two cultivation modes. However, the differences remain unclear. We conducted a regional-scale survey to investigate the pollution level, distribution, and sources of 20 OCPs, and to evaluate the soil physicochemical properties and bacterial community in soils from plastic shed and open-field locating the north areas of China. We found that levels of total OCPs in the plastic shed soils were significantly higher than those in the nearby open-field soils. Most of these OCPs were attributed to historical application, except for dichlorodiphenyltrichloroethanes (DDTs) due to the fresh input along with dicofol application. Soil pH (for both cultivation modes) and total organic carbon (TOC) content (only for plastic sheds) were significantly correlated with the total OCP concentrations. Additionally, microbial diversity and richness were generally lower in plastic shed soils than in nearby open-field soils for each region. The bacterial community variation among different regions might be principally determined by the soil type. Soil pH had the greatest impact on the microbial community across all plastic shed and open-field samples. These results provide a better understanding of the environmental impact and ecological risk of OCPs in soils with different cultivation modes.

Immobilization and release risk of arsenic associated with partitioning and reactivity of iron oxide minerals in paddy soils

The consumption of agricultural products grown on paddy soils contaminated with toxic element has a detrimental effect on human health. However, the processes and mechanisms of iron (Fe) mineral-associated arsenic (As) availability and As reactivity in different paddy soil profiles are not well understood. In this study, the fractions, immobilization, and release risk of As in eleven soil profiles from the Changzhutan urban agglomeration in China were investigated; these studied soils were markedly contaminated with As. Sequential extraction experiments were used to analyze fractions of As and Fe oxide minerals, and kinetic experiments were used to characterize the reactivity of Fe oxide minerals. The results showed that concentrations of total As and As fractions had a downward trend with depth, but the average proportions of As fractions only showed relatively small changes, which implied that the decrease in the total As concentrations influenced the changes in fraction concentrations along the sampling depth. Moreover, we found that easily reducible Fe (Fe_ox1) mainly controlled the reductive dissolution of the Fe oxides, which suggest that the reductive dissolution process could potentially release As during the flooded period of rice production. In addition, a high proportion of As was specifically absorbed As (As-F2) (average 20.4%) in paddy soils, higher than that in other soils. The total organic carbon (TOC) content had a positive correlation with the amount of non-specifically bound As (As-F1) (R = 0.56), which means that TOC was one factor that affected the As extractability in the As-F1. Consequently, high inputs of organic fertilizers may elevate the release of As and accelerate the diffusion of As. Graphical abstract.

Efficacy and safety of Chinese herbal compound in the treatment of functional constipation: A protocol for systematic review and meta-analysis

BACKGROUND

Functional constipation refers to constipation without organic lesions caused by dietary factors, mood depression, changes in life rules, and poor bowel habits. Clinically, constipation is mainly manifested by changes of stool texture, difficulty or lack of bowel movement, and dry stool. Sometimes, it can be accompanied by abdominal distension and abdominal discomfort. Chinese herbal compound is a prescription which is composed of 2 or more medicinal flavors and is designed for relatively certain diseases and syndromes. Clinical studies have shown that TCM compounds have a good therapeutic effect on functional constipation, but there is no evidence of evidence-based medicine. The purpose of this study is to systematically evaluate the efficacy and safety of TCM compounds in the treatment of functional constipation, and to provide evidence-based basis for the clinical application of TCM compounds in the treatment of constipation.

METHODS

A systematic search was performed on English database (PubMed, Embase, Web of Science, the Cochrane Library) and Chinese database (CNKI, Wanfang, Weipu (VIP), CBM), in addition to the manual retrieval of Baidu and Google academic for randomized controlled trials (RCTs) on the treatment of functional constipation with Chinese herbal compound. The retrieval time limit was from the establishment of the database to August 2020. Two researchers independently screened the literature, extracted the data and evaluated the quality of the included studies. A meta-analysis was performed using RevMan5.3 software.

RESULTS

In this study, the efficacy and safety of TCM herbal compounds in the treatment of functional constipation were evaluated by the overall effective rate, recovery rate, colonic transmission function, and other indicators.

CONCLUSIONS

This study will provide reliable evidence-based evidence for the clinical application of Chinese herbal compound in the treatment of functional constipation.

OSF REGISTRATION NUMBER

DOI 10.17605/OSF.IO/D5ECF.

Redox-dependent effects of phosphate on arsenic speciation in paddy soils

Evaluating speciation of arsenic (As) is essential to assess its risk in paddy soils. In this study, effects of phosphate on speciation of As in six paddy soils differing in redox status were studied over a range of pH (pH 3-9) and different background calcium (Ca) levels by batch adsorption experiments and speciation modeling. Contrasting effects of phosphate on As speciation were observed in suboxic and anoxic soils. Under suboxic conditions, phosphate inhibited Fe and As reduction probably due to stabilization of Fe-(hydr)oxides, but increased soluble As(V) concentration as a result of competitive adsorption between As(V) and phosphate. In anoxic soils, phosphate stimulated Fe and As reduction and caused increases of As(III) in soil solution under both acidic and neutral/alkaline pH. The LCD (Ligand and Charge Distribution) and NOM-CD (Natural Organic Matter-Charge Distribution) model can describe effects of pH, calcium and phosphate on As speciation in these paddy soils. The results suggest that phosphate fertilization may decrease (at low pH) or increase (at neutral/alkaline pH) As mobility in paddy soils under (sub)oxic conditions, but under anoxic conditions and in phosphorus deficient soils phosphate fertilization may strongly mobilize As by promoting microbial activities.

Prediction of the uptake of Cd by rice (Oryza sativa) in paddy soils by a multi-surface model

The uptake of Cd by crops from soils is predominantly determined by the concentration and speciation of Cd in soil solution, which is controlled by soil physicochemical properties such as soil pH, soil minerals and organic matter, etc. Water management significantly affects soil pH, and especially soil pH is driven to be neutral under continuous flooding treatment. In the present study, the multi-surface models (MSMs) were modified to determine Cd partitioning in soils for prediction of Cd uptake by rice grain, with multiple parameter or setup changes including: (1) soil pH was considered as variables to improve the accuracy of model prediction for paddy soils; (2) practical co-existing cation concentration and ionic strength were derived from electron conductivity to improve the universality of model. Our results suggested that the modified MSMs model provided a better prediction for the actual uptake by rice grain and a more consistent Cd distribution pattern in paddy soils.