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In the process of sewage treatment, the sewage usually needs to be aerated, so the oxygenation efficiency is an important indicator for the aerator. The general oxygenation technique is to inject large amount of natural air into the aeration tank over long time, which has lower efficiency and leads to dramatic waste of energy. Based on the gas-liquid fusion mass transfer model and combined the oxygen enrichment mechanism by magnetization of the gas into the aerator, a novel method to improve the efficiency of wastewater oxygenation is proposed. This method is based on the fact that oxygen and nitrogen exhibit completely different magnetic characteristics in gradient magnetic fields, and then the special shaped permanent magnets can be used to build a target gradient magnetic field to increase the oxygen content as the gas is injected into the sewage by the aerator, which reaches the oxygenation enhancement effect. Through theoretical analysis and experiments, it is concluded that the efficiency of sewage oxygenation treatment is dramatically improved with the permanent magnet oxygen enrichment technique. HIGHLIGHTS A new method is introduced to improve the aerator's oxygenation effect, and the method is proven to be effective through theory and experiment.; The method uses a magnetized oxygen enrichment device installed on the aerator, which consists of permanent magnets with a triangular cross section. The permanent magnets in the device build up a high gradient non-uniform magnetic field.;

COVID-19 pandemic continues to spread throughout the world with an urgent demand for a safe and protective vaccine to effectuate herd protection and control the spread of SARS-CoV-2. Here, we report the development of a bacterial vector COVID-19 vaccine (aPA-RBD) that carries the gene for the receptor-binding domain (RBD) of the SARS-CoV-2 spike protein. Live-attenuated strains of Pseudomonas aeruginosa (aPA) were constructed which express the recombinant RBD and effectively deliver RBD protein into various antigen presenting cells through bacterial type 3 secretion system (T3SS) in vitro. In mice, two-dose of intranasal aPA-RBD vaccinations elicited the development of RBD-specific serum IgG and IgM. Importantly, the sera from the immunized mice were able to neutralize host cell infections by SARS-CoV-2 pseudovirus as well as the authentic virus variants potently. T-cell responses of immunized mice were assessed by enzyme-linked immunospot (ELISPOT) and intracellular cytokine staining (ICS) assays. aPA-RBD vaccinations can elicit RBD-specific CD4+and CD8+T cell responses. T3SS-based RBD intracellular delivery heightens the efficiency of antigen presentation and enables the aPA-RBD vaccine to elicit CD8+T cell response. Thus, aPA vector has the potential as an inexpensive, readily manufactured, and respiratory tract vaccination route vaccine platform for other pathogens

Abstract Monitoring the temporal and spatial variation of soil properties is helpful to understand the evolution of soil properties and adjust the management method in time. Soil fertility evaluation is an urgent need to understand soil fertility level and prevent soil degradation. Here, we conducted an intensive field investigation in Chinese hickory (Carya cathayensis Sarg.) plantation to clarify the spatial and temporal variation of soil properties and its influencing factors, and to evaluate the change of soil fertility. The results showed that the soil pH and soil organic carbon (SOC) significantly increased from 2008 to 2018, while available nitrogen (AN) significantly decreased from 2008 to 2018. The semi-variance revealed that except available phosphorus (AP), the spatial dependencies of soil properties increased from 2008 to 2018. An increasing south-north gradient was found for soil AN, AP, available potassium (AK) and SOC and a decreasing south-north gradient was found for soil pH. The average soil fertility in the whole area was increased from 2008 to 2018. Our findings demonstrated that the changes of the management measures were the reason for the change of soil properties from 2008 to 2018. Therefore, rational fertilization strategies and sod cultivation are recommended to maintain the long-term development of the producing forest.

BackgroundChanges in IgG glycosylation, as a novel pathological feature, are observed in various autoimmune diseases (AIDs). The glycosylation patterns of IgG play a critical role in regulating the biological function and stability of IgG involved in the pathophysiology of many AIDs. However, the intracellular regulatory mechanisms underlying the effects of disturbances in various cytokines on IgG glycosylation are poorly understood. Thus, we investigated the regulatory effects of elevated cytokines in AIDs on intracellular IgG glycosylation within B cells.MethodsFirst, we established a controlled primary culture system in vitro to differentiate human CD19+ B cells into antibody-secreting cells (ASCs). Then, the IgG concentrations in the supernatants were measured by enzyme-linked immunoassay (ELISA) under IFN-γ, TNF-α, IL-21, IL-17A, BAFF, or APRIL stimulation. Next, the glycosylation levels of IgG under different stimuli were compared via a lectin microarray. The fine carbohydrate structures of IgG were confirmed by matrix-assisted laser desorption/ionization-quadrupole ion trap-time of flight-mass spectrometry (MALDI-TOF-MS). Finally, the expression of glycosyltransferases and glycosidases in B cells under stimulation with several cytokines was detected by real-time PCR and western blotting.ResultsWe found that cytokines significantly promoted IgG production in vitro and led to considerably different IgG glycan patterns. Specifically, the results of lectin microarray showed the galactose level of IgG was increased by IFN-γ stimulation (p

Summary: The densely glycosylated spike (S) protein highly exposed on severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) surface mediates host cell entry by binding to the receptor angiotensin-converting enzyme 2 (ACE2). However, the role of glycosylation has not been fully understood. In this study, we investigated the effect of different N-glycosylation of S1 protein on its binding to ACE2. Using real-time surface plasmon resonance assay the negative effects were demonstrated by the considerable increase of binding affinities of de-N-glycosylated S1 proteins produced from three different expression systems including baculovirus-insect, Chinese hamster ovarian and two variants of human embryonic kidney 293 cells. Molecular dynamic simulations of the S1 protein-ACE2 receptor complex revealed the steric hindrance and Coulombic repulsion effects of different types of N-glycans on the S1 protein interaction with ACE2. The results should contribute to future pathological studies of SARS-CoV-2 and therapeutic development of Covid-19, particularly using recombinant S1 proteins as models.

Chinese Torreya grandis (Torreya grandis cv. Merrillii) is a unique economic tree species in China. Intensive management related to application of chemical fertilizer and herbicides caused serious soil quality degradation of Chinese Torreya grandis plantations. Totally, 120 soil samples were collected from the main disbtributed areas of Chinese Torreya grandis in Southeastern China. In this area, soil pH values varied from 3.68 to 6.78, with a median value of 4.91, implying a trend of acidification. The average concentrations of organic matter, available nitrogen, available phosphorus and available potassium were 27.52 g kg-1, 135.77 mg kg-1, 15.12 mg kg-1, and 153.43 mg kg-1, respectively. The results of spatial analysis revealed that target variables had clear spatial patterns. The soil fertility was relevantly high in most of the study area, with soil nutrient imbalances existing. The stand age had a large effect on soil properties, which were also mainly influenced by human activities. Therefore, it is necessary to change the fertilization method for a sustainable management of Torreya grandis plantation. [ABSTRACT FROM AUTHOR]

Spatial pattern information of forest biomass carbon (FBC) density in forest ecosystems plays an important role in evaluating carbon sequestration potentials and forest management. The spatial variation of FBC density in a subtropical region of southeastern China was studied using geostatistics combined with Moran's I and geographical information systems (GIS). Forest biomass carbon density values were variable, ranging from 0.12 Mg ha-1 to 182.12 Mg ha-1, with an average of 27.33 Mg ha-1. The FBC density had the strongest positive correlation with forest age, followed by forest litter and elevation. The FBC density had significant positive spatial autocorrelation revealed by global Moran's I. Clear spatial patterns were observed based on local Moran's I. High FBC density values were mainly distributed in the northwestern and southwestern parts of Zhejiang province, which were related to adopting long-term policy of forest conservation in these areas, while low FBC density values located in the middle part and southeastern coastal area of the study area due to low forest coverage and intensive management of economic forests. The Moran's I combined with geostatistical interpolation proved to be a useful tool for studying spatial variation of FBC density. [ABSTRACT FROM AUTHOR]

Purpose: Although the bioavailability of heavy metals has been widely investigated, little information is available on the spatial correlations of heavy metals in soil-rice systems at a regional scale. A study of heavy metals in soil-rice systems at a present rice production area could provide valuable information on the safety of rice production and provide guidelines beneficial to agriculture management and strategic sustainable agriculture in China and other rapidly developing regions in the world. The overall goals of this study were to identify the characteristics of metal fractions and their bioavailability to rice plants in the paddy fields of a present rice production region. Materials and methods: In the rice harvest season (October 2006), 96 pairs of rice grain and rooted soil samples were collected from rice production area of Wenling in southeast Zhejiang province, China, which is one of the well-known electronic and electric waste (E-waste) recycling centers. Soil samples were analyzed for total heavy metal concentrations, metal fraction concentrations, and soil properties. Soil properties analyzed in this study included soil pH, electrical conductivity, organic matter, Fe oxides, and soil particle size distribution. Rice grain samples were analyzed for heavy metal concentrations. Multivariate statistical and geostatistical methods were applied to study the spatial dependence characteristics of metal fractions and their spatial correlation with uptake by rice plants in the rice production area and to identify the bioavailability of metal fractions to rice plants. Results and discussion: The paddy soils of the studied area showed Cd contamination and some paddy soils presented a potential Cu, Ni, and Zn risk. The elevated levels of Cd were predominantly in non-residual (extractable) fractions. The percentage of Cd in fractions decreased in the order of exchangeable > Fe-Mn oxide bound > residual > organic bound fraction. In contrast, soil Cu, Ni, Pb, and Zn were mainly in the residual (non-extractable) fractions. The fractions of Ni, Pb, and Zn followed the order of residual > Fe-Mn oxide bound > organic bound > exchangeable fraction; the fractions of Cu decreased in the order of residual > organic bound > Fe-Mn oxide bound fraction. The spatial distribution patterns of non-residual fractions exhibited similarities with the highest metal concentrations in the northwest area owing to the industries and E-waste recycling activities. Most metals in rice grain were the strongest spatially correlated with the exchangeable fraction, followed by the organic bound fraction, indicating that exchangeable and organic bound fractions had the highest bioavailability. Rice Cd and Zn were strong spatially correlated with exchangeable, Fe-Mn oxide, and organic bound fractions; rice Ni and Cu were strongly spatially correlated with the exchangeable and organic bound fractions, respectively. The principal component analysis results also confirmed that exchangeable, Fe-Mn oxide, and organic bound soil fractions can be considered as bioavailable fractions to rice for Cd and Zn, while exchangeable and organic fractions were more important sinks for Ni and Cu, respectively. Conclusions: Due to a comparatively high input of Cd in the paddy soils, soil Cd was predominantly associated with non-residual fractions, especially with the exchangeable fraction. The soil Cu, Ni, Pb, and Zn were largely associated with the residual fraction while little associated with the exchangeable fraction. The bioavailability of the fractions to rice varied with metal fractions. In general, the exchangeable fraction had the highest bioavailability to rice plants, followed by the organic bound fraction. The bioavailability of the fractions to rice also varied with heavy metals. The exchangeable, Fe-Mn oxide, and organic bound fractions had high bioavailability to rice for Cd and Zn; the exchangeable and organic bound fractions had highest bioavailability for Ni and Cu, respectively. [ABSTRACT FROM AUTHOR]

As a source of nutrient supplements, the deficiency or excess of micronutrients in soil is directly connected to the plant uptake and, thereby, status of micronutrients in the human population. Proper management of micronutrients requires an understanding of the variations of soil micronutrients across the fields. This study is to investigate the spatial patterns of soil available Zn and Cu in paddy rice fields. Four hundred and sixty three soil samples were taken in Hangzhou–Jiaxing–Huzhou (HJH) watershed in Zhejiang Province, China, and available Zn and Cu were analyzed using an atomic adsorption spectrometer. Geostatistical semivariograms analysis indicated that the available Zn and Cu were best fitted to a spherical model with a range of 40.5 and 210.4 km, respectively. There were moderate spatial dependences for Zn and Cu over a long distance and the dependence were attributed to soil types and anthropogenic activities. The overlay analysis of spatial patterns and soil types gave us greater understanding about how intrinsic factors affect the spatial variation of available micronutrients. Based on the above, macroscopically regionalized management of soil available micronutrients and the implications to potential risk were discussed. [ABSTRACT FROM AUTHOR]

This study explored the effects of soil acidification on degradation of Chinese hickory forest under field experimental conditions. Responses of plant nutrient absorption and non-targeted metabolomics based on LC-MS were analyzed to understand the mechanisms of Chinese hickory plant to acid resistance and susceptibility. In this field experiment, Chinese hickory plants were treated with CK (T1, control), nitrogen application (urea) (T2), and aluminum application (aluminum sulfate) (T3). Results showed that Al is the key toxic factor of acidification of soils planted with Chinese hickory. T2 and T3 treatments significantly inhibited absorption of nutrient elements (N, P, K, Ca, Mg, Cu, B and Zn) by Chinese hickory (except N in T2). The metabolomics data analysis showed that there were differences in plant metabolites between the experimental group (T2 and T3) and the control (T1), including p-coumaroyl quinic acid, chlorogenic acid, catechin, (+) germacrene A, myricetin 3-galactoside, and neoglucobrassicin. These metabolites may be the main regulators of Chinese hickory to soil acid stress or related to the effect of soil acidification on Chinese hickory resistance. KEGG metabolic pathway enrichment analysis showed that these differential metabolites were mainly enriched in four metabolic pathways: Flavonoid biosynthesis, Phenylpropanoid biosynthesis, Tyrosine metabolism, Stilbenoid, diarylheptanoid, and gingerol biosynthesis. This study provides a reference for metabolomics studies in Chinese hickory. [ABSTRACT FROM AUTHOR]