[Vertical Distribution Characteristics and Driving Factors of Bacterioplankton and Nitrogen Phosphorus Cycle Genes in Danjiangkou Reservoir].

Danjiangkou Reservoir is a critical water source for the South-to-North Water Diversion Project, which harbors a diverse bacterioplankton community with varying depths, and the understanding of its nitrogen and phosphorus cycle and associated driving factors remains limited. In this study, we selected five ecological sites within Danjiangkou Reservoir and conducted metagenomics analysis to investigate the vertical distribution of bacterioplankton communities in the surface, middle, and bottom layers. Furthermore, we analyzed and predicted the function of nitrogen and phosphorus cycles, along with their driving factors. Our findings revealed the dominance of Proteobacteria, Actinobacteria, and Planctomycetes in the Danjiangkou Reservoir. Significant differences were observed in the structure of bacterioplankton communities across different depths, with temperature （T）, oxidation-reduction potential （ORP）, dissolved oxygen （DO）, and Chla identified as primary factors influencing the bacterioplankton composition. Analysis of nitrogen cycle functional genes identified 39 genes, including gltB, glnA, gltD, gdhA, NRT, etc., which were involved in seven main pathways, encompassing nitrogen fixation, nitrification, denitrification, and dissimilatory nitrate reduction. Phosphorus cycle function gene analysis identified 54 genes, including pstS, ppx-gppA, glpQ, ppk1, etc., primarily participating in six main pathways, including organic P mineralization, inorganic P solubilization, and regulatory. Cluster analysis indicated that different depths were significant factors influencing the composition and abundance of nitrogen and phosphorus cycle functional genes. The composition and abundance of nitrogen and phosphorus cycle functional genes in the surface and bottom layers differed and were generally higher than those in the middle layer. Deinococcus, Hydrogenophaga, Limnohabitans, Clavibacter, and others were identified as key species involved in the nitrogen and phosphorus cycle. Additionally, we found significant correlations between nitrogen and phosphorus cycle functional genes and environmental factors such as DO, pH, T, total dissolved solids （TDS）, electrical conductivity （EC）, and Chla. Furthermore, the content of these environmental factors exhibited depth-related changes in the Danjiangkou Reservoir, resulting in a distinct vertical distribution pattern of bacterioplankton nitrogen and phosphorus cycle functional genes. Overall, this study sheds light on the composition, function, and influencing factors of bacterioplankton communities across different layers of Danjiangkou Reservoir, offering valuable insights for the ecological function and diversity protection of bacterioplankton in this crucial reservoir ecosystem.

Screening of plant growth-promoting rhizobacteria helps alleviate the joint toxicity of PVC+Cd pollution in sorghum plants.

Combined microplastic and heavy metal pollution (CM-HP) has become a popular research topic due to the ability of these pollutants to have complex interactions. Plant growth-promoting rhizobacteria (PGPR) are widely used to alleviate stress from heavy metal pollution in plants. However, the effects and mechanisms by which these bacteria interact under CM-HP have not been extensively studied. In this study, we isolated and screened PGPR from CM-HP soils and analyzed the effects of these PGPR on sorghum growth and Cd accumulation under combined PVC+Cd pollution through pot experiments. The results showed that the length and biomass of sorghum plants grown in PVC+Cd contaminated soil were significantly lower than those grown in soils contaminated with Cd alone, revealing an enhancement in toxicity when the two contaminants were mixed. Seven isolated and screened PGPR strains effectively alleviated stress due to PVC+Cd contamination, which resulted in a significant enhancement in sorghum biomass. PGPR mitigated the decrease in soil available potassium, available phosphorus and alkali-hydrolyzable nitrogen content caused by combined PVC+Cd pollution and increased the contents of these soil nutrients. Soil treatment with combined PVC+Cd pollution and PGPR inoculation can affect rhizosphere bacterial communities and change the composition of dominant populations, such as Proteobacteria, Firmicutes, and Actinobacteria. PICRUSt2 functional profile prediction revealed that combined PVC+Cd pollution and PGPR inoculation affected nitrogen fixation, nitrification, denitrification, organic phosphorus mineralization, inorganic phosphorus solubilization and the composition and abundance of genes related the N and P cycles. The Mantel test showed that functional strain abundance, the diversity index and N and P cycling-related genes were affected by test strain inoculation and were significant factors affecting sorghum growth, Cd content and accumulation. This study revealed that soil inoculation with isolated and screened PGPR can affect the soil inorganic nutrient content and bacterial community composition, thereby alleviating the stress caused by CM-HP and providing a theoretical basis and data support for the remediation of CM-HP.

Plant Growth-Promoting Bacteria Influence Microbial Community Composition and Metabolic Function to Enhance the Efficiency of Hybrid pennisetum Remediation in Cadmium-Contaminated Soil.

The green and efficient remediation of soil cadmium (Cd) is an urgent task, and plant-microbial joint remediation has become a research hotspot due to its advantages. High-throughput sequencing and metabolomics have technical advantages in analyzing the microbiological mechanism of plant growth-promoting bacteria in improving phytoremediation of soil heavy metal pollution. In this experiment, a pot trial was conducted to investigate the effects of inoculating the plant growth-promoting bacterium Enterobacter sp. VY on the growth and Cd remediation efficiency of the energy plant Hybrid pennisetum. The test strain VY-1 was analyzed using high-throughput sequencing and metabolomics to assess its effects on microbial community composition and metabolic function. The results demonstrated that Enterobacter sp. VY-1 effectively mitigated Cd stress on Hybrid pennisetum, resulting in increased plant biomass, Cd accumulation, and translocation factor, thereby enhancing phytoremediation efficiency. Analysis of soil physical-chemical properties revealed that strain VY-1 could increase soil total nitrogen, total phosphorus, available phosphorus, and available potassium content. Principal coordinate analysis (PCoA) indicated that strain VY-1 significantly influenced bacterial community composition, with Proteobacteria, Firmicutes, Chloroflexi, among others, being the main differential taxa. Redundancy analysis (RDA) revealed that available phosphorus, available potassium, and pH were the primary factors affecting bacterial communities. Partial Least Squares Discriminant Analysis (PLS-DA) demonstrated that strain VY-1 modulated the metabolite profile of Hybrid pennisetum rhizosphere soil, with 27 differential metabolites showing significant differences, including 19 up-regulated and eight down-regulated expressions. These differentially expressed metabolites were primarily involved in metabolism and environmental information processing, encompassing pathways such as glutamine and glutamate metabolism, α-linolenic acid metabolism, pyrimidine metabolism, and purine metabolism. This study utilized 16S rRNA high-throughput sequencing and metabolomics technology to investigate the impact of the plant growth-promoting bacterium Enterobacter sp. VY-1 on the growth and Cd enrichment of Hybrid pennisetum, providing insights into the regulatory role of plant growth-promoting bacteria in microbial community structure and metabolic function, thereby improving the microbiological mechanisms of phytoremediation.

Effects of combined microplastic and cadmium pollution on sorghum growth, Cd accumulation, and rhizosphere microbial functions.

The interaction between microplastics (MPs) and cadmium (Cd) poses a threat to agricultural soil environments, and their effects on plant growth and rhizosphere microbial community functions are not yet clear. In this study, energy sorghum was used as a test plant to investigate the effects of two types of MPs, polystyrene (PS) and polyethylene (PE), at different particle sizes (13 µm, 550 µm) and concentrations (0.1%, 1% w/w), and Cd, as well as their interactions, on the growth of sorghum in a soil-cultivation pot experiment. The results showed that the combined effects of MP and Cd pollution on the dry weight and Cd accumulation rate in sorghum varied depending on the type, concentration, and particle size of the MPs, with an overall trend of increasing stress from combined pollution with increasing Cd content and accumulation. High-throughput sequencing analysis revealed that combined MP and Cd pollution increased bacterial diversity, and the most significant increase was observed in the abundance-based coverage estimator (ACE), Shannon, and Sobs indices in the 13 µm 1% PS+Cd treatment group. Metagenomic analysis based on the Kyoto Encyclopedia of Genes and Genomes (KEGG) metabolic pathways revealed that 19 groups of metabolic pathways, including microbial metabolism and methane metabolism, differed significantly under combined MP and Cd pollution. Hierarchical clustering results indicated that Cd treatment and combined MP and Cd treatment affected the abundances of sorghum rhizosphere soil nitrogen (N) and phosphorus (P) cycling genes and that the type of MP present was an important factor affecting N and P cycling genes. The results of this study provide a basis for exploring the toxic effects of combined MP and Cd pollution and for conducting soil environmental risk assessments.

[Effects of Combined Stress of High Density Polyethylene Microplastics and Chlorimuron-ethyl on Soybean Growth and Rhizosphere Bacterial Community].

With the vigorous development of agriculture in China， plastic mulch film and pesticides are widely used in agricultural production. However， the accumulation of microplastics （formed by the degradation of plastic mulch film） and pesticides in soil has also caused many environmental problems. At present， the environmental biological effects of microplastics or pesticides have been reported， but there are few studies on the combined effects on crop growth and the rhizosphere soil bacterial community. Therefore， in this study， the high density polyethylene microplastics （HDPE， 500 mesh） were designed to be co-treated with sulfonylurea herbicide chlorimuron-ethyl to study their effects on soybean growth. In addition， the effects of the combined stress of HDPE and chlorimuron-ethyl on soybean rhizosphere soil bacterial community diversity， structure composition， microbial community network， and soil function were investigated using high-throughput sequencing technology， interaction network， and PICRUSt2 function analysis to clarify the combined toxicity of HDPE and chlorimuron-ethyl to soybean. The results showed that the half-life of chlorimuron-ethyl in soil was prolonged by the 1% HDPE treatment （from 11.5 d to 14.3 d）， and the combined stress of HDPE and chlorimuron-ethyl had more obvious inhibition effects on soybean growth than that of the single pollutant or control. The HiSeq 2 500 sequencing showed that the rhizosphere bacterial community of soybean was composed of 20 phyla and 312 genera under combined stress， the number of phyla and genera was significantly less than that of the control and single pollutant treatment， and the relative abundances of bacteria with potential biological control and plant growth-promoting characteristics （such as Nocardioides and Sphingomonas） were reduced. Alpha diversity analysis showed that the combined stress significantly reduced the richness and diversity of the soybean rhizosphere bacterial community， and Beta diversity analysis showed that the combined stress significantly changed the structure of the bacterial community. The dominant flora of the rhizosphere bacterial community were regulated， and the abundances of secondary functional layers such as amino acid metabolism， energy metabolism， and lipid metabolism were reduced under combined stress by the analysis of LEfSe and PICRUSt2. It was inferred from the network analysis that the combined stress of HDPE and chlorimuron-ethyl reduced the total number of connections and network density of soil bacteria， simplified the network structure， and changed the important flora species to maintain the stability of the network. The results above indicated that the combined stress of HDPE and chlorimuron-ethyl significantly affected the growth of soybean and changed the rhizosphere bacterial community structure， soil function， and network structure. Compared with that of the single pollutant treatment， the potential risk of combined stress was greater. The results of this study can provide guidance for evaluating the ecological risks of polyethylene microplastics and chlorimuron-ethyl and for the remediation of contaminated soil.

Plant growth-promoting bacteria improve the Cd phytoremediation efficiency of soils contaminated with PE-Cd complex pollution by influencing the rhizosphere microbiome of sorghum.

Composite pollution by microplastics and heavy metals poses a potential threat to the soilplant system and has received increasing attention. Plant growth-promoting bacteria (PGPB) have good application potential for the remediation of combined microplastic and heavy metal pollution, but few related studies exist. The present study employed a pot experiment to investigate the effects of inoculation with the PGPB Bacillus sp. SL-413 and Enterobacter sp. VY-1 on sorghum growth and Cd accumulation under conditions of combined cadmium (Cd) and polyethylene (PE) pollution. Cd+PE composite contamination led to a significant reduction in sorghum length and biomass due to increased toxicity. Inoculation with Bacillus sp. SL-413 and Enterobacter sp. VY-1 alleviated the stress caused by Cd+PE complex pollution, and the dry weight of sorghum increased by 25.7% to 46.1% aboveground and by 12.3% to 45.3% belowground. Bacillus sp. SL-413 and Enterobacter sp. VY-1 inoculation increased the Cd content and accumulation in sorghum and improved the phytoremediation efficiency of Cd. The inoculation treatment effectively alleviated the nutrient stress caused by the reduction in soil mineral nutrients due to Cd+PE composite pollution. The composition of the soil bacterial communities was also affected by the Cd, Cd+PE and bacterial inoculation treatments, which affected the diversity of the soil bacterial communities. Network analyses indicated that bacterial inoculation regulated the interaction of rhizospheric microorganisms and increased the stability of soil bacterial communities. The Mantel test showed that the changes in the soil bacterial community and function due to inoculation with Bacillus sp. SL-413 and Enterobacter sp. VY-1 were important factors influencing sorghum growth and Cd remediation efficiency. The results of this study will provide new evidence for the research on joint plantmicrobe remediation of heavy metal and microplastic composite pollution.

[Transcriptome Analysis of Plant Growth-promoting Bacteria Alleviating Microplastic and Heavy Metal Combined Pollution Stress in Sorghum].

Microplastics can become potential transport carriers of other environmental pollutants (such as heavy metals), so the combined pollution of microplastics and heavy metals has attracted increasing attention from researchers. To explore the mechanism of plant growth-promoting bacteria VY-1 alleviating the combined pollution stress of heavy metals and microplastics in sorghum, the effects of inoculation on biomass and accumulation of heavy metals in sorghum were analyzed using a hydroponics experiment, and the effects of inoculation on gene expression in sorghum were analyzed via transcriptomics. The results showed that the combined pollution of polyethylene (PE) and cadmium (Cd) decreased the dry weight of above-ground and underground parts by 17.04% and 10.36%, respectively, compared with that under the single Cd pollution, which showed that the combined toxicity effect of the combined pollution on plant growth was enhanced. The inoculation of plant growth-promoting bacteria VY-1 could alleviate the toxicity of Cd-PE combined pollution and increase the length of aboveground and underground parts by 33.83% and 73.21% and the dry weight by 56.64% and 33.44%, respectively. Transcriptome sequencing showed that 904 genes were up-regulated after inoculation with VY-1. Inoculation with growth-promoting bacteria VY-1 could up-regulate the expression of several genes in the auxin, abscisic acid, flavonoid synthesis, and lignin biosynthesis pathways, which promoted the response ability of sorghum under Cd-PE combined pollution stress and improved its resistance. The above results indicated that plant growth-promoting bacteria could alleviate the stress of heavy metal and microplastic combined pollution by regulating plant gene expression, which provided a reference for plant-microbial joint remediation of heavy metal and microplastic combined pollution.

[Effects of Combined Pollution of Microplastics and Cadmium on Microbial Community Structure and Function of Pennisetum hydridum Rhizosphere Soil].

The combined pollution of microplastics and heavy metals can potentially interact. This may have an important impact on the growth and development of plants and the rhizosphere microbial community and function. In this study, the effects of heavy metal cadmium combined with different types of microplastics(PE and PS), different particle sizes(13 µm and 550 µm), and different concentrations(0.1% and 1%) on Pennisetum hydridum growth were studied under pot conditions. The results showed that the effects of the combined pollution of MPs and Cd on plant dry weight and Cd accumulation varied with different types, concentrations, and particle sizes of MPs, and the combined pollution stress increased, whereas the Cd content and Cd accumulation decreased. Metagenomic analysis showed that the combined contamination of MPs and Cd could change the composition of the bacterial community and reduce bacterial diversity, among which the ACE index and Chao1 index in the 550 µm 0.1% PE+Cd treatment group were the most significant. Metagenomic analysis of microbial species function showed that the main functional groups were metabolism, amino acid transport and metabolism, energy generation and conversion, and signal transduction mechanisms. Compared with that under single Cd pollution, the addition of MPs could change the gene abundance of functional groups such as metabolism, amino acid transport and metabolism, and energy generation and conversion, and the effects of different MPs types, concentrations, and particle sizes varied. In this study, metagenomics and amplification sequencing were used to analyze the effects of the combined pollution of MPs and Cd on the bacterial community and function in P. hydridum in order to provide basic data and scientific basis for the ecotoxicological effects of the combined heavy metal pollution of MPs and its biological remediation.

Plant growth-promoting bacteria modulate gene expression and induce antioxidant tolerance to alleviate synergistic toxicity from combined microplastic and Cd pollution in sorghum.

Microplastics (MPs) can act as carriers for environmental pollutants; therefore, MPs combined with heavy metal pollution are attracting increasing attention from researchers. In this study, the potential of the plant growth-promoting bacterium Bacillus sp. SL-413 to mitigate the stress caused by exposure to both MPs and cadmium (Cd) in sorghum plants was investigated. The effects of inoculation on sorghum biomass were investigated using hydroponic experiments, and evaluation of Cd accumulation and enzyme activity changes and transcriptomics approaches were used to analyze its effect on sorghum gene expression. The results showed that combined polyethylene (PE) and Cd pollution reduced the length and the fresh and dry weights of sorghum plants and thus exerted a synergistic toxic effect. However, inoculation with the strains alleviated the stress caused by the combined pollution and significantly increased the biomass. Inoculation increased the dry weights of the aboveground and belowground parts by 11.5-44.6% and 14.9-38.4%, respectively. Plant physiological measurements indicated that inoculation reduced the reactive oxygen species (ROS) content of sorghum by 10.5-27.2% and thereby alleviated oxidative stress. Transcriptome sequencing showed that exposure to combined Cd+MP contamination induced downregulation of gene expression, particularly that of genes related to amino sugar and nucleotide sugar metabolism, starch and sucrose metabolism, and plant hormone signal transduction, in sorghum. However, inoculation with Bacillus sp. SL-413 resulted in an increase in the proportion of upregulated genes involved in signal transduction, antioxidant defense, cell wall biology, and other metabolic pathways, which included the phenylpropanoid biosynthesis, photosynthesis, flavonoid biosynthesis, and MAPK signaling pathways. The upregulation of these genes promoted the tolerance of sorghum under combined Cd+MP pollution stress and alleviated the stress induced by these conditions. This study provides the first demonstration that plant growth-promoting bacteria can alleviate the stress caused by combined pollution with MPs and Cd by regulating plant gene expression. These findings provide a reference for the combined plant-microbial remediation of MPs and Cd.

Poor Concordance of One-Third Anterior-Posterior Chest Diameter Measurements With Absolute Age-Specific Chest Compression Depth Targets in Pediatric Cardiac Arrest Patients.

Background Current pediatric cardiac arrest guidelines recommend depressing the chest by one-third anterior-posterior diameter (APD), which is presumed to equate to absolute age-specific chest compression depth targets (4 cm for infants and 5 cm for children). However, no clinical studies during pediatric cardiac arrest have validated this presumption. We aimed to study the concordance of measured one-third APD with absolute age-specific chest compression depth targets in a cohort of pediatric patients with cardiac arrest. Methods and Results This was a retrospective observational study from a multicenter, pediatric resuscitation quality collaborative (pediRES-Q [Pediatric Resuscitation Quality Collaborative]) from October 2015 to March 2022. In-hospital patients with cardiac arrest ≤12 years old with APD measurements recorded were included for analysis. One hundred eighty-two patients (118 infants >28 days old to <1 year old, and 64 children 1 to 12 years old) were analyzed. The mean one-third APD of infants was 3.2 cm (SD, 0.7 cm), which was significantly smaller than the 4 cm target depth (P<0.001). Seventeen percent of the infants had one-third APD measurements within the 4 cm ±10% target range. For children, the mean one-third APD was 4.3 cm (SD, 1.1 cm). Thirty-nine percent of children had one-third APD within the 5 cm ±10% range. Except for children 8 to 12 years old and overweight children, the measured mean one-third APD of the majority of the children was significantly smaller than the 5 cm depth target (P<0.05). Conclusions There was poor concordance between measured one-third APD and absolute age-specific chest compression depth targets, particularly for infants. Further study is needed to validate current pediatric chest compression depth targets and evaluate the optimal chest compression depth to improve cardiac arrest outcomes. Registration URL: https://www.clinicaltrials.gov; Unique identifier: NCT02708134.

[Effects of Microplastic High-density Polyethylene on Cotton Growth, Occurrence of Fusarium wilt, and Rhizosphere Soil Bacterial Community].

Plastic mulch, especially polyethylene mulch, is widely used in agricultural production in China, but the microplastics formed by its degradation gradually have accumulated in soil, causing a series of environmental problems. At present, there have been many reports on the environmental biological effects of microplastics in farmland soil, but studies on the effects of microplastics on crop growth, disease occurrence, and rhizosphere soil bacterial communities are still lacking. In the previous study, it was found that 1% high-density polyethylene (HDPE, 500 mesh) could increase the incidence rate of cotton Fusarium wilt (33.3%) and inhibit growth, but this phenomenon was not found after soil sterilization. It was speculated that HDPE could affect the growth and occurrence of Fusarium wilt by regulating the soil microbial community. Therefore, high-throughput sequencing technology, combined with network and FAPROTAX function analysis, were used to investigate the effects of HDPE on the bacterial community structure, interaction network, and soil function in cotton rhizosphere in order to analyze the mechanism of HDPE. NovaSeq sequencing showed that the bacterial community of HDPE-treated cotton rhizosphere soil was composed of 54 phyla and 472 genera; the number of phyla and genera was higher than that in untreated soil. The α and ß diversity and ANOSIM/Adonis analyses showed that HDPE significantly reduced the richness of the bacterial community and changed the composition of the community structure. Based on a T-test species difference analysis, HDPE significantly reduced the relative abundance of bacteria with biological control, pollutant degradation, and antifungal drug synthesis (such as Kribbella, Massiliam, Hailiangium, and Ramlibacter).The change in the bacterial community will lead to the change in soil bacterial function. Further analysis of FAPROTAX function revealed that HDPE weakened some biochemical functions of bacteria in the cotton rhizosphere soil, such as aerobic chemoheterotrophy, fermentation, and nitrate reduction. The correlation network at the genus level showed that HDPE treatment weakened the interaction between rhizosphere bacteria, reduced the number of positive correlation connections, increased the number of negative correlation connections, simplified network structure, and changed the key flora. The above results showed that HDPE could reduce the cotton growth and the occurrence of Fusarium wilt by changing the bacterial community, interaction, and functional metabolism in rhizosphere soil, which can provide guidance for evaluating the ecological risk of polyethylene microplastics and the remediation of contaminated soil.

Enhancing Mechanisms of the Plant Growth-Promoting Bacterial Strain Brevibacillus sp. SR-9 on Cadmium Enrichment in Sweet Sorghum by Metagenomic and Transcriptomic Analysis.

To explore the mechanism by which the plant growth-promoting bacterium Brevibacillus sp. SR-9 improves sweet sorghum tolerance and enriches soil cadmium (Cd) under pot conditions, the effect of strain SR-9 inoculation on the microbial community of sorghum rhizosphere soil was analyzed by metagenomics. Gene expression in sweet sorghum roots was analyzed using transcriptomics. The results showed that strain SR-9 promoted the growth of sweet sorghum and improved the absorption and enrichment of Cd in the plants. Compared with the uninoculated treatment, the aboveground part and root dry weight in strain SR-9 inoculated with sorghum increased by 21.09% and 17.37%, respectively, and the accumulation of Cd increased by 135% and 53.41%, respectively. High-throughput sequencing showed that strain SR-9 inoculation altered the rhizosphere bacterial community, significantly increasing the relative abundance of Actinobacteria and Firmicutes. Metagenomic analysis showed that after inoculation with strain SR-9, the abundance of genes involved in amino acid transport metabolism, energy generation and conversion, and carbohydrate transport metabolism increased. KEGG functional classification showed that inoculation with strain SR-9 increased the abundance of genes involved in soil microbial metabolic pathways in the rhizosphere soil of sweet sorghum and the activity of soil bacteria. Transcriptome analysis identified 198 upregulated differentially expressed genes in sweet sorghum inoculated with strain SR-9, including those involved in genetic information processing, biological system, metabolism, environmental information processing, cellular process, and human disease. Most of the annotated differentially expressed genes were enriched in the metabolic category and were related to pathways such as signal transduction, carbohydrate metabolism, amino acid metabolism, and biosynthesis of other secondary metabolites. This study showed that plant growth-promoting bacteria can alter the rhizosphere bacterial community composition, increasing the activity of soil bacteria and upregulating gene expression in sweet sorghum roots. The findings enhance our understanding of the microbiological and botanical mechanisms by which plant growth-promoting bacterial inoculation improves the remediation of heavy metals by sorghum.

[High-Throughput Sequencing Combined with Metabonomics to Analyze the Effect of Heavy Metal Contamination on Farmland Soil Microbial Community and Function].

Heavy metal contamination affects microbial composition and diversity. The interaction between heavy metal contamination and soil microorganisms has been a hot topic in ecological research. Battery manufacturing has been going on for over six decades in Xinxiang City, resulting in severe soil heavy metal contamination due to battery wastewater runoff. Few studies have investigated the effect of heavy metal contamination due to long-term battery wastewater runoff on microbial diversity and metabolomics in Xinxiang City. In this study, we collected samples from three heavy metal contaminated sites in Xinxiang City and found that Cd and Pb exceeded the recommended thresholds by 34-66 fold and 1.5-2.32 fold, respectively. High-throughput sequencing showed that Bacillus, Arthrobacter, Sphingomonas, and Streptomyces were the dominant bacteria genera, while Olpidium, Plectosphaerella, and Gibellulopsis were the dominant fungi genera, indicating that heavy metal contaminated soil in Xinxiang City was rich in heavy metal tolerant bacteria and fungi due to the long-term heavy metal stress. Correlation analysis showed that total Cu, DTPA extract Cu, and water soluble Pb were significant factors in bacterial diversity, while total Cd, total Ni, total Pb, total Zn, DTPA extract Cu, and water soluble Pb were significant factors in fungal diversity. To better understand the effect of heavy metal contamination on the metabolism of soil microorganisms, we conducted non-targeted metabolomic profiling, which showed significant differences in metabolites across the samples. Pathway enrichment analysis showed that these differential metabolites were involved in pathways such as metabolism, environmental information processing, and genetic Information Processing, which may play a role in heavy metal stress mitigation and environmental adaptation.

The Seasonal Patterns, Ecological Function and Assembly Processes of Bacterioplankton Communities in the Danjiangkou Reservoir, China.

As the water source for the Middle Route Project of the South-to-North Water Diversion Project (MR-SNWD) of China, the Danjiangkou Reservoir (DJR) is in the process of ecosystem reassembly, but the composition, function, and assembly mechanisms of bacterioplankton communities are not yet clear. In this study, the composition, distribution characteristics and influencing factors of bacterioplankton communities were analyzed by high-throughput sequencing (HTS); PICRUSt2 was used to predict community function; a molecular ecological network was used to analyze bacterioplankton interactions; and the assembly process of bacterioplankton communities was estimated with a neutral model. The results indicated that the communities, function and interaction of bacterioplankton in the DJR had significant annual and seasonal variations and that the seasonal differences were greater than that the annual differences. Excessive nitrogen (N) and phosphorus (P) nutrients in the DJR are the most important factors affecting water quality in the reservoir, N and P nutrients are the main factors affecting bacterial communities. Season is the most important factor affecting bacterioplankton N and P cycle functions. Ecological network analysis indicated that the average clustering coefficient and average connectivity of the spring samples were lower than those of the autumn samples, while the number of modules for the spring samples was higher than that for the autumn samples. The neutral model explained 66.3%, 63.0%, 63.0%, and 70.9% of the bacterioplankton community variations in samples in the spring of 2018, the autumn of 2018, the spring of 2019, and the autumn of 2019, respectively. Stochastic processes dominate bacterioplankton community assembly in the DJR. This study revealed the composition, function, interaction, and assembly of bacterioplankton communities in the DJR, providing a reference for the protection of water quality and the ecological functions of DJR bacterioplankton.

Should paediatric chest compression depth targets consider body habitus? - A chest computed tomography imaging study.

AIM: This study explored how body habitus in the paediatric population might potentially affect the use of one-third external anterior-posterior (APD) diameter when compared to age-appropriate absolute chest compression depth targets. It also explored how body habitus could potentially affect the relationship between one-third external and internal APD (compressible space) and if body habitus indices were independent predictors of internal APD at the lower half of the sternum. METHODS: This was a secondary analysis of a retrospective study of chest computed tomography (CT) scans of infants and children (>24-hours-of-life to less-than-18-years-old) from 2005 to 2017. Patients' scan images were reviewed for internal and external APDs at the mid-point of the lower half of the sternum. Body habitus and epidemiological data were extracted from the electronic medical records. RESULTS: Chest CT scans of 193 infants and 398 children were evaluated. There was poor concordance between one-third external APD measurements and age-specific absolute chest compression depth targets, especially in infants and overweight/obese adolescents. There was a co-dependent relationship between one-third external APD and internal APD measurements. Overweight/obese children's and adolescents' internal and external APDs were significant different from the normal/underweight groups. Body-mass-index (BMI) of children and adolescents (p = 0.009), but not weight-for-length (WFL) of infants (p = 0.511), was an independent predictor of internal APD at the compression landmark. CONCLUSION: This study demonstrated correlations between external and internal APDs which were affected by BMI but not WFL (infants). Clinical studies are needed to validate current chest compression guidelines especially for infants and overweight/obese adolescents.(250 words).

[Polyamine-producing Bacteria Regulated the Community Structure of Rhizosphere Bacteria and Reduced the Absorption of Cd in Wheat].

Some functional microorganisms in the soil immobilize heavy metals by adsorption and precipitation, prevent the absorption of heavy metals by crops, and play an important role in the passivation and remediation of medium and mild heavy metal-contaminated soil. A pot experiment was conducted to study the effects of the exogenous polyamine-producing bacterium Bacillus sp. N3 on Cd uptake and the bacterial community composition and function in the rhizosphere soil. The results showed that strain N3 significantly reduced the contents of Cd (64.7%) in wheat grain and DTPA-Cd (50.1%) in rhizosphere soil and increased the pH (from 6.84 to 6.97) and polyamine content. High-throughput sequencing results showed that inoculation of strain N3 reduced the diversity of the bacterial community; however, it increased the relative abundances of ß-Proteobacteria, Bacteroidetes, and Firmicutes in wheat rhizosphere soil. Meanwhile, strain N3 also increased the relative abundances of heavy metal-immobilizing bacteria and plant growth-promoting bacteria (Bacillus, Arthrobacter, Brevundimonas, Ensifer, Pedobacter, Rhizobium, Pseudomonas, Enterobacter, and Serratia) in wheat rhizosphere soil. The PICRUSt function prediction showed that strain N3 increased the copy number of genes involved in antioxidant capacity, hormone synthesis, and sulfur metabolism in wheat rhizosphere soil. These results indicated that the polyamine-producing bacteria N3 reduced the DTPA-Cd content by increasing the pH; the polyamine contents; the abundances of bacteria with heavy metal-immobilizing or plant growth-promoting traits; and the metabolic pathway involved in antioxidant capacity, hormone synthesis, and sulfur metabolism in wheat rhizosphere soil, thus inhibiting the absorption of Cd by wheat. The results provide theoretical basis and technical support for restoring farmland with excessive heavy metals and ensuring the safe production of wheat.

Corrigendum to "Should paediatric chest compression depth targets consider body habitus? - A chest computed tomography imaging study" [Resuscitation Plus 9 (2022) 100202].

[This corrects the article DOI: 10.1016/j.resplu.2022.100202.].

Responses of rhizosphere bacterial communities, their functions and their network interactions to Cd stress under phytostabilization by Miscanthus spp.

Miscanthus has good tolerance to heavy metals (HMs) and has received increasing attention in studies of HM-contaminated soil remediation. In this study, four Miscanthus cultivars (M. lutarioriparius Xiangnadi NO4, M. sinensis Xiangmang NO1, M. lutarioriparius × M. sinensis hybrid Xiangzamang NO1, and M. floridulus Wujiemang NO1) that grow in China were studied. Their tolerance and enrichment abilities in soils containing 50 mg kg-1 cadmium (Cd) and the structure and function of their rhizosphere bacterial communities during the remediation process were analyzed. The results exhibiting a tolerance index (TI) higher than 75 in roots and the aboveground parts (TI > 60, indicating highly tolerant plants) indicated that all four Miscanthus cultivars were tolerant to high Cd concentrations. Moreover, Cd was mainly enriched in roots, the translocation ability from roots to aboveground parts was weak, and the four cultivars exhibited phytostabilization ability in Cd-contaminated soils. High-throughput sequencing (HTS) analysis showed that the Miscanthus rhizosphere bacterial community comprised 33 phyla and 446 genera, including plant growth-promoting rhizobacteria (PGPRs), such as Bacillus, Sphingomonas, and Mesorhizobium. The addition of Cd affected the Miscanthus rhizosphere bacterial community and reduced community diversity. Phylogenetic molecular ecological networks (pMENs) indicated that Cd addition reduced interactions between Miscanthus rhizosphere bacteria and thereby led to a simpler network structure, increased the number of negative-correlation links, enhanced the competition between rhizosphere bacterial species, reduced the number of key bacteria, and changed the composition of those bacteria. PICRUSt functional predictive analysis indicated that Cd stress reduced soil bacterial functions in the Miscanthus rhizosphere. The results of this study provide a basis for the remediation of Cd-contaminated soils by Miscanthus and provide a reference for the subsequent regulation of Miscanthus remediation efficiency by PGPRs or key bacteria.

[Shifts in Rhizosphere Bacterial Community Structure, Co-occurrence Network, and Function of Miscanthus Following Cadmium Exposure].

As a representative of second-generation bioenergy plants, Miscanthus has received increasing attention in the studies of heavy metal (HM)-contaminated soil remediation. Currently, few studies have examined the effects of using Miscanthus to remediate HM-contaminated soils on the composition and function of microbial communities. In this study, the Miscanthus cultivar M. saccariflorus was examined for its tolerance and enrichment abilities when grown in soils containing 100 mg ·kg-1 of cadmium (Cd). The structure, function, and co-occurrence network of their rhizosphere bacterial communities were analyzed during the remediation process. MiSeq sequencing showed that the Miscanthus rhizosphere bacterial community comprised 32 phyla and 425 genera, including plant growth-promoting rhizobacteria (PGPR), such as Sphingomonas, Bacillus, Gemmatimonas, and Streptomyces. The addition of Cd affected the Miscanthus rhizosphere bacterial community and reduced community diversity. Phylogenetic molecular ecological networks indicated that Cd addition reduced the interactions between Miscanthus rhizosphere bacteria to generate a simpler network structure, increased the number of negative-correlation links, enhanced the competition between rhizosphere bacterial species, and changed the composition of key bacteria. PICRUSt functional predictive analysis indicated that Cd stress reduced soil bacterial functions in the Miscanthus rhizosphere. The results of this study provide a reference for the subsequent regulation of efficient Miscanthus remediation by PGPRs or key bacteria.

What is the potential for over-compression using current paediatric chest compression guidelines? - A chest computed tomography study.

AIM: We explored the potential for over-compression from current paediatric chest compression depth guidelines using chest computed tomography(CT) images of a large, heterogenous, Asian population. METHODS: A retrospective review of consecutive children, less than 18-years old, with chest CT images performed between from 2005 to 2017 was done. Demographic data were extracted from the electronic medical records. Measurements for internal and external anterior-posterior diameters (APD) were taken at lower half of the sternum. Simulated chest compressions were performed to evaluate the proportion of the population with residual internal cavity dimensions less than 0 mm (RICD < 0 mm, representing definite over-compression; with chest compression depth exceeding internal APD), and RICD less than 10 mm (RICD < 10 mm, representing potential over-compression). RESULTS: 592 paediatric chest CT studies were included for the study. Simulated chest compressions of one-third external APD had the least potential for over-compression; no infants and 0.3% children had potential over-compression (RICD < 10 mm). 4 cm simulated chest compressions led to 18% (95% CI 13%-24%) of infants with potential over-compression, and this increased to 34% (95% CI 27%-41%) at 4.4 cm (upper limit of "approximately" 4 cm; 4 cm + 10%). 5 cm simulated compressions resulted in 8% (95% CI 4%-12%) of children 1 to 8-years-old with potential over-compression, and this increased to 22% (95% CI 16%-28%) at 5.5 cm (upper limit of "approximately" 5 cm, 5 cm + 10%). CONCLUSION: In settings whereby chest compression depths can be accurately measured, compressions at the current recommended chest compression of approximately 4 cm (in infants) and 5 cm (in young children) could result in potential for over-compression.