Distinct biophysical and chemical mechanisms governing sucrose mineralization and soil organic carbon priming in biochar amended soils: evidence from 10 years of field studies.

While many studies have examined the role of biochar in carbon (C) accrual in short-term scale, few have explored the decadal scale influences of biochar on non-biochar C, e.g., native soil organic C (SOC) and added substrate. To address this knowledge gap, soils were collected from decade-old biochar field trials located in the United Kingdom (Cambisol) and China (Fluvisol), with each site having had three application rates (25-30, 50-60 and 75-100 Mg ha-1) of biochar plus an unamended Control, applied once in 2009. We assessed physicochemical and microbial properties associated with sucrose (representing the rhizodeposits) mineralization and the priming effect (PE) on native SOC. Here, we showed both soils amended with biochar at the middle application rate (50 Mg ha-1 biochar in Cambisol and 60 Mg ha-1 biochar in Fluvisol) resulted in greater substrate mineralization. The enhanced accessibility and availability of sucrose to microorganisms, particularly fast-growing bacterial genera like Arenimonas, Spingomonas, and Paenibacillus (r-strategists belonging to the Proteobacteria and Firmicutes phyla, respectively), can be attributed to the improved physicochemical properties of the soil, including pH, porosity, and pore connectivity, as revealed by synchrotron-based micro-CT. Random forest analysis also confirmed the contribution of the microbial diversity and physical properties such as porosity on sucrose mineralization. Biochar at the middle application rate, however, resulted in the lowest PE (0.3 and 0.4 mg of CO2-C g soil-1 in Cambisol and Fluvisol, respectively) after 53 days of incubation. This result might be associated with the fact that the biochar promoted large aggregates formation, which enclosed native SOC in soil macro-aggregates (2-0.25 mm). Our study revealed a diverging pattern between substrate mineralization and SOC priming linked to the biochar application rate. This suggests distinct mechanisms, biophysical and physicochemical, driving the mineralization of non-biochar carbon in a field where biochar was applied a decade before. Supplementary Information: The online version contains supplementary material available at 10.1007/s42773-024-00327-0.

Isolation and Characterization of a Novel Recombinant Classical Pseudorabies Virus in the Context of the Variant Strains Pandemic in China.

Pseudorabies virus (PRV) variants were discovered in immunized pigs in Northern China and have become the dominant strains since 2011, which caused huge economic losses. In this study, a classical PRV strain was successfully isolated in a PRV gE positive swine farm. The complete genome sequence was obtained using a high-throughput sequencing method and the virus was named JS-2020. The nucleotide homology analysis and phylogenetic tree based on complete genome sequences or gC gene showed that the JS-2020 strain was relatively close to the classical Ea strain in genotype II clade. However, a large number of amino acid variations occurred in the JS-2020 strain compared with the Ea strain, including multiple immunogenic and virulence-related genes. In particular, the gE protein of JS-2020 was similar to earlier Chinese PRV strains without Aspartate insertion. However, the amino acid variations analysis based on major immunogenic and virulence-related genes showed that the JS-2020 strain was not only homologous with earlier PRV strains, but also with strains isolated in recent years. Moreover, the JS-2020 strain was identified as a recombinant between the GXGG-2016 and HLJ-2013 strains. The pathogenicity analysis proved that the PRV JS-2020 strain has typical neurogenic infections and a strong pathogenicity in mice. Together, a novel recombinant classical strain was isolated and characterized in the context of the PRV variant pandemic in China. This study provided some valuable information for the study of the evolution of PRV in China.

Efficacy of a porcine reproductive and respiratory syndrome virus 1 (PRRSV-1) natural recombinant against a heterologous PRRSV-1 isolate both clustered within the subgroup of BJEU06-1-like isolates.

Porcine reproductive and respiratory syndrome virus 1 (PRRSV-1) has been prevalent in more than 20 provinces of China. However, no PRRSV-1-specific vaccine is commercially available in China. To evaluate the feasibility of using a low virulent PRRSV-1 isolate against potential outbreaks caused by virulent Chinese PRRSV-1 isolates, here we evaluated the efficacy of a low virulent PRRSV-1 HLJB1 strain isolated in 2014 as live vaccine against a virulent PRRSV-1 SD1291 strain isolated in 2022. Genome-based phylogenetic analysis showed that both HLJB1 and SD1291 were grouped within BJEU06-1-like isolates. However, they shared only 85.27% genomic similarity. Piglet inoculation and challenge study showed that HLJB1 inoculation could reduce viremia but did not significantly alleviate clinical signs and tissue lesions. Virus neutralization test indicated that HLJB1 inoculation could induce homologous neutralizing antibodies (NAbs) but no heterologous NAbs at 42 dpi. In addition, flow cytometric analyses showed that no memory T follicular helper (Tfh) cells against SD1291 and SD1291-specific IFN-γ secreting cells were induced by HLJB1 pre-inoculation. These results supported that HLJB1 inoculation only provides partial cross-protection against SD1291 infection even though they are clustered within the same PRRSV-1 subgroup, which is closely related to the failure in conferring cross-protective adaptive immune responses.

Precision Graphene Nanoribbon Heterojunctions by Chain-Growth Polymerization.

Graphene nanoribbons (GNRs) are considered promising candidates for next-generation nanoelectronics. In particular, GNR heterojunctions have received considerable attention due to their exotic topological electronic phases at the heterointerface. However, strategies for their precision synthesis remain at a nascent stage. Here, we report a novel chain-growth polymerization strategy that allows for constructing GNR heterojunction with N=9 armchair and chevron GNRs segments (9-AGNR/cGNR). The synthesis involves a controlled Suzuki-Miyaura catalyst-transfer polymerization (SCTP) between 2-(6'-bromo-4,4''-ditetradecyl-[1,1':2',1''-terphenyl]-3'-yl) boronic ester (M1) and 2-(7-bromo-9,12-diphenyl-10,11-bis(4-tetradecylphenyl)-triphenylene-2-yl) boronic ester (M2), followed by the Scholl reaction of the obtained block copolymer (poly-M1/M2) with controlled Mn (18 kDa) and narrow D (1.45). NMR and SEC analysis of poly-M1/M2 confirm the successful block copolymerization. The solution-mediated cyclodehydrogenation of poly-M1/M2 toward 9-AGNR/cGNR is unambiguously validated by FT-IR, Raman, and UV/Vis spectroscopies. Moreover, we also demonstrate the on-surface formation of pristine 9-AGNR/cGNR from the unsubstituted copolymer precursor, which is unambiguously characterized by scanning tunneling microscopy (STM).

Controls for phytolith accumulation in Moso bamboo leaves across China.

Phytoliths are amorphous silica formed gradually in plant tissue, which have great potential to mitigate climate change due to their resistance to decomposition and their ability to occlude organic carbon. The accumulation of phytoliths is regulated by multiple factors. However, the factors controlling its accumulation remain unclear. Here, we investigated phytolith content in Moso bamboo leaves of different ages collected from 110 sampling sites of their main distribution regions across China. The controls for phytolith accumulation were studied by correlation and random forest analyses. Our results showed that phytolith content is leaf age-dependent (16-month-old leaf >4-month-old leaf >3-month-old leaf). Phytolith accumulation rate in Moso bamboo leaves is significantly correlated with mean monthly temperature (MMT) and mean monthly precipitation (MMP). About 67.1 % of the variance of the phytolith accumulation rate could be explained by multiple environmental factors, mainly MMT and MMP. Therefore, we conclude that the weather is the major driver that regulates the phytolith accumulation rate. Our study provides a unique dataset for estimating phytolith production rate and the potential carbon sequestration of phytolith through climatic factors.

Enhancement of phytolith-occluded carbon accumulation of Moso bamboo response to temperatures elevation and different fertilization.

The accumulation of phytolith-occluded carbon (PhytOC) in Moso bamboo could be a novel long-term carbon sequestration strategy. The objective of this study was to investigate the effects of temperature change and different fertilization on PhytOC accumulation. The pot experiment was established with different fertilization (including control (CK), nitrogen fertilizers (N), silicon fertilizers (Si), and a combination of nitrogen and silicon (NSi)) under high- and low-temperature. Despite the different fertilization, the PhytOC accumulation of the high-temperature group increases by 45.3% on average compared with the low-temperature group, suggesting higher temperature is greatly beneficial to the PhytOC accumulation. Fertilization significantly increases the accumulation of PhytOC (increased by 80.7% and 48.4% on average for the low- and high-temperature group, respectively) compared with CK. However, the N treatment increased both Moso bamboo biomass and PhytOC accumulation. The difference in the accumulation of PhytOC in Si and NSi was insignificant, indicating the combination of N and Si didn't bring extra benefit to PhytOC accumulation compared to Si fertilizer alone. These results indicated the application of nitrogen fertilizer is a practical and effective method for enhancing long-term carbon sequestration for Moso bamboo. Based on our study, we conclude that global warming poses a positive effect on promoting the long-term carbon sequestration of Moso bamboo.

Discovery of Resveratrol and its Derivatives as Novel Antiviral and Anti- Phytopathogenic-Fungus Agents.

BACKGROUND: Plant diseases caused by viruses and pathogens have posed a serious threat to global agricultural production and are difficult to control. Natural products have always been a valuable source for lead discovery in medicinal and agricultural chemistry. The natural product resveratrol was found to have good antiviral activity against the tobacco mosaic virus (TMV) and fungicidal activities against 14 kinds of phytopathogenic fungi. OBJECTIVE: The aim of this work was to design, synthesize a series of derivatives of resveratrol, and evaluate their antiviral and fungicidal activities systematically. METHODS: Novel resveratrol sulfonate derivatives were prepared by a convenient synthesis method from resveratrol, alkyl sulfonyl chloride, aryl sulfonyl chloride, and heterocyclic sulfonyl chloride. Their structures were also identified by nuclear magnetic resonance (NMR) spectroscopy and high-resolution mass spectrometry (HRMS). RESULTS: Most of the targets were obtained at a high yield. Compounds I-2, I-5, I-10, II-2, and II-4, with excellent antiviral activities, showed higher anti-TMV activities than those of lead compounds and commercial ribavirin (inhibitory rates of 38, 37, and 38% at 500 µg/mL for inactivation, curative, and protection activities in vivo, respectively). In particular, compounds I-5, I-10, II-2, and II-4 displayed similar inhibitory effects as ningnanmycin (inhibitory rates of 54, 56, and 58% at 500 µg/mL for inactivation, curative, and protection activities in vivo, respectively), the best antiviral agent at present, thereby emerging as new antiviral pilot compounds. Further fungicidal activity tests showed that resveratrol derivatives also displayed broad-spectrum fungicidal activities. CONCLUSION: The anti-TMV activities of these compounds were discovered for the first time. Some of these simply structured compounds showed higher TMV inhibitory effects than ribavirin. The current study provided valuable insights into the antiviral and fungicidal activities of resveratrol derivatives, but more modification of the structure should be conducted.

Zika virus non-structural protein 4B interacts with DHCR7 to facilitate viral infection.

Zika virus (ZIKV) evolves non-structural proteins to evade immune response and ensure efficient replication in the host cells. Cholesterol metabolic enzyme 7-dehydrocholesterol reductase (DHCR7) was recently reported to impact innate immune responses in ZIKV infection. However, the vital non-structural protein and mechanisms involved in DHCR7-mediated viral evasion are not well elucidated. In this study, we demonstrated that ZIKV infection facilitated DHCR7 expression. Notably, the upregulated DHCR7 in turn facilitated ZIKV infection and blocking DHCR7 suppressed ZIKV infection. Mechanically, ZIKV non-structural protein 4B (NS4B) interacted with DHCR7 to induce DHCR7 expression. Moreover, DHCR7 inhibited TANK-binding kinase 1 (TBK1) and interferon regulatory factor 3 (IRF3) phosphorylation, which resulted in the reduction of interferon-beta (IFN-ß) and interferon-stimulated genes (ISGs) productions. Therefore, we propose that ZIKV NS4B binds to DHCR7 to repress TBK1 and IRF3 activation, which in turn inhibits IFN-ß and ISGs, and thereby facilitating ZIKV evasion. This study broadens the insights on how viral non-structural proteins antagonize innate immunity to facilitate viral infection via cholesterol metabolic enzymes and intermediates.

Mechanism of LSD1 in oxygen-glucose deprivation/reoxygenation-induced pyroptosis of retinal ganglion cells via the miR-21-5p/NLRP12 axis.

BACKGROUND: Retinal ganglion cells (RGCs) are important retinal neurons that connect visual receptors to the brain, and lysine-specific demethylase 1 (LSD1) is implicated in the development of RGCs. This study expounded the mechanism of LSD1 in oxygen-glucose deprivation/reoxygenation (OGD/R)-induced pyroptosis of RGCs. METHODS: Mouse RGCs underwent OGD/R exposure, and then RGC viability was examined using the cell counting kit-8 method. The mRNA levels of Caspase 1, the protein levels of NOD-like receptor family pyrin domain-containing 3 (NLRP3), N-terminal fragment of gasdermin D (GSDMD-N), and cleaved-Caspase1, and the concentrations of interleukin (IL)-1ß and IL-18 were respectively examined. Subsequently, LSD1 expression was intervened to explore the underlying effect of LSD1 on OGD/R-induced pyroptosis of RGCs. Afterwards, the enrichments of LSD1 and histone H3 lysine 4 methylation (H3K4me) 1/2 on the microRNA (miR)-21-5p promoter were determined using chromatin-immunoprecipitation assay. And the binding interaction between miR-21-5p and NLRP12 was detected using dual-luciferase and RNA pull-down assays. Finally, the effects of miR-21-5p/NLRP12 on LSD1-mediated pyroptosis of RGCs were verified through functional rescue experiments. RESULTS: OGD/R treatment increased pyroptosis of RGCs and LSD1 expression. Silencing LSD1 declined levels of Caspase 1 mRNA, NLRP3, GSDMD-N, cleaved-Caspase1, IL-1ß, and IL-18 and limited pyroptosis of OGD/R-treated RGCs. Mechanically, LSD1 suppressed miR-21-5p expression via demethylation of H3K4me2 on the miR-21-5p promoter to hamper the binding of miR-21-5p to NLRP12, and thereby increased NLRP12 expression. Silencing miR-21-5p or overexpressing NLRP12 facilitated OGD/R-induced pyroptosis of RGCs. CONCLUSION: LSD1-mediated demethylation of H3K4me2 decreased miR-21-5p expression to increase NLRP12 expression, promoting pyroptosis of OGD/R-treated RGCs.

High Pathogenicity of a Chinese NADC34-like PRRSV on Pigs.

NADC34-like porcine reproductive and respiratory syndrome virus (PRRSV) has been reported to be prevalent in China since 2018 and became one of the main epidemic strains in some areas of China. Yet, the pathogenicity of NADC34-like PRRSV tested by experimental infection has seldomly been investigated. In this study, we infected pigs with JS2021NADC34 PRRSV, a Chinese NADC34-like PRRSV isolated in Jiangsu province in 2021, to study the pathogenicity of this virus strain. Pigs infected with this virus had lasting fever and reduced body weight with high morbidity and mortality. Histopathological changes, including interstitial pneumonia, lymphocyte depletion, acute hemorrhage, and infiltration of neutrophils in the lymphoid tissues, were observed with the viral proteins detected by immunohistochemistry staining using PRRSV-specific antibody. These results suggested that JS2021NADC34 PRRSV is highly pathogenic to pigs. As it is the latest emerging PRRSV strain in China, the prevalence and pathogenicity of NADC34-like PRRSV need to be further investigated. IMPORTANCE NADC34 PRRSV was initially reported in the United States in 2018. Subsequently, this virus strain spread to other countries, including Peru, South Korea, and China. The virus was first found circulating in Northeast China and then spread to more than 10 provinces in China. NADC34 PRRSV causes severe abortion of sows and high mortality of piglets, which lead to huge economic losses to the Chinese pig industry. However, the pathogenicity of NADC34 PRRSV was rarely experimentally evaluated on pigs. In this study, pigs were infected with JS2021NADC34 PRRSV, a Chinese NADC34-like PRRSV isolated in Jiangsu province in 2021. The infected pigs had lasting fever and reduced body weight with high morbidity and mortality. Interstitial pneumonia, lymphocyte depletion, acute hemorrhage, and infiltration of neutrophils were observed in the lymphoid tissues, and high virus load was proved by immunohistochemistry staining. The above results indicated that NADC34 PRRSV has high pathogenicity on pigs.

The synergy of Fe(III) and NO2- drives the anaerobic oxidation of methane.

The anaerobic oxidation of methane (AOM) driven by NO2- or Fe(III) alone was limited by slow electron delivery and ineffective enrichment of microbes. The flexible coupling between Fe(III) and NO2- potentially cooperated to accelerate AOM. One negative control was fed CH4 and NO2-, and four treatment reactors were supplemented with CH4, NO2- and ferric citrate (FC)/ferric chloride (FCH)/ chelate iron (FCI)/ferric hydroxide (FH) and were anaerobically operated for 1200 days to verify the synergy and promicrobial roles of Fe(III) and NO2- in improving AOM. The changes in gas and ion profiles were observed in the reactors, and microbial development was studied using 16S rRNA gene sequencing with the Illumina platform. The results indicated that the combined Fe(III) and NO2- treatment improved AOM, and their synergy followed the order of FC > FCI > FCH > FH. The biochemical reaction of Fe3+ with NO2- and its secondary process accelerated electron transfer to microbial cells and subsequently enhanced AOM in the reactors. The total organic carbon (TOC) content, NH4+ content, NO3- content, and pH value altered the dominant bacteria the most in the FC reactor, FCI, FCH, and FH groups, respectively. Several dominant bacterial species were enriched, whereas only two archaea were highly concentrated in the FC and FCI groups. Only bacteria were detected in the FCH group, and archaea contributed substantially to the FH group. These findings contribute to an improved understanding of the interactions among nitrogen, iron and CH4 that are paramount to accelerating the process of AOM for engineering applications.

Systemic Homologous Neutralizing Antibodies Are Inadequate for the Evaluation of Vaccine Protective Efficacy against Coinfection by High Virulent PEDV and PRRSV.

G2 porcine epidemic diarrhea virus (G2 PEDV) and highly pathogenic porcine reproductive and respiratory syndrome virus 2 (HP-PRRSV2) are two of the most prevalent swine pathogens in China's swine herds, and their coinfection occurs commonly. Several PED and PRRS vaccines have been utilized in China for decades, and systemic homologous neutralizing antibodies (shnAbs) in serum are frequently used to evaluate the protective efficacy of PED and PRRS vaccines. To develop a vaccine candidate against G2 PEDV and HP-PRRSV2 coinfection, in this study, we generated a chimeric virus (rJSTZ1712-12-S) expressing S protein of G2 PEDV using an avirulent HP-PRRSV2 rJSTZ1712-12 infectious clone as the viral vector. The rJSTZ1712-12-S strain has similar replication efficacies as the parental rJSTZ1712-12 virus. In addition, animal inoculation indicated that rJSTZ1712-12-S is not pathogenic to piglets and can induce shnAbs against both G2 PEDV and HP-PRRSV2 isolates after prime-boost immunization. However, passive transfer study in neonatal piglets deprived of sow colostrum showed that rJSTZ1712-12-S-induced shnAbs may only decrease PEDV and PRRSV viremia but cannot confer sufficient protection against dual challenge of high virulent G2 PEDV XJ1904-34 strain and HP-PRRSV2 XJ17-5 isolate. Overall, this study provides the first evidence that shnAbs confer insufficient protection against PEDV and PRRSV coinfection and are inadequate for the evaluation of protective efficacy of PED and PRRS bivalent vaccine (especially for the PED vaccine). IMPORTANCE Porcine epidemic diarrhea virus (PEDV) and porcine reproductive and respiratory syndrome virus (PRRSV) coinfection occurs commonly and can synergistically reduce feed intake and pig growth. Vaccination is an effective strategy utilized for PED and PRRS control, and systemic homologous neutralizing antibodies (shnAbs) in serum are commonly used for protective efficacy evaluation of PED and PRRS vaccines. Currently, no commercial vaccine is available against PEDV and PRRSV coinfection. This study generated a chimeric vaccine candidate against the coinfection of prevalent PEDV and PRRSV in China. The chimeric strain can induce satisfied shnAbs against both PEDV and PRRSV after prime-boost inoculation in pigs. But the shnAbs cannot confer sufficient protection against PEDV and PRRSV coinfection in neonatal piglets. To the best of our knowledge, these findings provide the first evidence that shnAbs confer insufficient protection against PEDV and PRRSV coinfection and are inadequate for evaluating PED and PRRS bivalent vaccine protective efficacy.

Copper-Catalyzed Dynamic Kinetic C-P Cross-Coupling/Cyclization for the Concise Asymmetric Synthesis of Six-, Seven- and Eight-Membered P-Stereogenic Phosphorus Heterocycles.

A copper-catalyzed asymmetric aryl C-P cross-coupling/cyclization reaction was successfully developed via dynamic kinetic asymmetric transformation (DYKAT) under mild conditions. This study provides a general and simple method for the catalytic enantioselective synthesis of stable six-, seven- and eight-membered P-stereogenic phosphorus heterocycles with excellent enantioselectivities and moderate to high yields. One-pot gram-scale asymmetric synthesis of the P-stereogenic P-heterocycle from commercially available materials was also successfully accomplished with excellent enantioselectivity and high yield.

Natural phytoalexin stilbene compound resveratrol and its derivatives as anti-tobacco mosaic virus and anti-phytopathogenic fungus agents.

Plant diseases caused by plant viruses and pathogens seriously affect crop yield and quality, and it is very difficult to control them. The discovery of new leads based on natural products is an important way to innovate pesticides. Based on the resveratrol is a kind of natural phytoalexin, but it cannot be used as candidate for the development of new drug due to its poor druggability. The phenolic hydroxyl groups in the resveratrol structure are easily destroyed by oxidation, in order to improve its stability, ester formation is the most commonly used modification method in drug design. Their structures were characterized by 1H NMR, 13C NMR and HRMS. The activity against tobacco mosaic virus (TMV) of these ester derivatives has been tested for the first time. The bioassay results showed part of the target compounds exhibited good to excellent in vivo activities against TMV. The optimum compounds III-2 (inhibitory rates of 50, 53, and 59% at 500 µg/mL for inactivation, curative, and protection activities in vivo, respectively), III-4 (inhibitory rates of 57, 59, and 51% at 500 µg/mL, respectively), and II-5 (inhibitory rates of 54, 52, and 51% at 500 µg/mL, respectively) displayed higher activity than commercial plant virucide ribavirin (inhibitory rates of 38, 37, and 40% at 500 µg/mL, respectively). Compounds I-9 and I-10 also showed excellent activities. The systematic study provides strong evidence that these simple resveratrol derivatives could become potential TMV inhibitors. The novel concise structure provides another new template for antiviral studies.

Chimeric HP-PRRSV2 containing an ORF2-6 consensus sequence induces antibodies with broadly neutralizing activity and confers cross protection against virulent NADC30-like isolate.

Due to the substantial genetic diversity of porcine reproductive and respiratory syndrome virus (PRRSV), commercial PRRS vaccines fail to provide sufficient cross protection. Previous studies have confirmed the existence of PRRSV broadly neutralizing antibodies (bnAbs). However, bnAbs are rarely induced by either natural infection or vaccination. In this study, we designed and synthesized a consensus sequence of PRRSV2 ORF2-6 genes (ORF2-6-CON) encoding all envelope proteins based on 30 representative Chinese PRRSV isolates. The ORF2-6-CON sequence shared > 90% nucleotide identities to all four lineages of PRRSV2 isolates in China. A chimeric virus (rJS-ORF2-6-CON) containing the ORF2-6-CON was generated using the avirulent HP-PRRSV2 JSTZ1712-12 infectious clone as a backbone. The rJS-ORF2-6-CON has similar replication efficiency as the backbone virus in vitro. Furthermore, pig inoculation and challenge studies showed that rJS-ORF2-6-CON is not pathogenic to piglets and confers better cross protection against the virulent NADC30-like isolate than a commercial HP-PRRS modified live virus (MLV) vaccine. Noticeably, the rJS-ORF2-6-CON strain could induce bnAbs while the MLV strain only induced homologous nAbs. In addition, the lineages of VDJ repertoires potentially associated with distinct nAbs were also characterized. Overall, our results demonstrate that rJS-ORF2-6-CON is a promising candidate for the development of a PRRS genetic engineered vaccine conferring cross protection.

Double effects of biochar in affecting the macropore system of paddy soils identified by high-resolution X-ray tomography.

Biochars are widely used to improve soil macropore structures. However, the size-dependent effects of biochars in affecting macropore structure still remain unclear. In this study, the modification of soil macropore structure following biochar addition was investigated by high-resolution X-ray tomography (CT) and advanced data analytical methods. Quantification of soil macropore structure (>52 µm) was based on the intact soil cores (5 cm in diameter and 7 cm in height) collected from biochar-amended paddy soil. The treatments were: (a) control (CK), (b) rice straw biochar (RSB), (c) corn straw biochar (CSB), and (d) bamboo biochar (BB). The application rate of biochar was 25 Mg ha-1 (w/w). Results revealed that the biochars affected the soil macropores through both "occupying effect" and "expansion effect". The "occupying effect" means that the biochar particles occupy the original pore space of the soil and reduce the soil porosity, while the "expansion effect" means that the biochar particles produce additional pore space in the soil matrix and increase the soil porosity. For all the biochar treatments in our study, the "occupying effect" was dominated. Therefore, the connected- and isolated porosity of biochar-treated soils were significantly lower than those of CK. The size-dependent effects of biochar in modifying soil macropores were observed. For RSB treatment, the "expansion effect" predominated at the size of <1200 µm and >1800 µm, while both the "occupying effect" and "expansion effect" were observed at the size of 1200-1800 µm. For CSB and BB treatments, the "expansion effect" predominate only at the size of 600-1200 µm; whereas both the "occupying effect" and "expansion effect" were observed at the size of <600 µm and >1800 µm. Our results indicated that the effects of biochar on soil macroporosity were dependent on the combined effects the "occupying effect" and "expansion effect". In conclusion, all the biochar types in this study have adverse effects in increasing the soil macroporosity.

Chemical constituents from Glehnia littoralis and their chemotaxonomic significance.

Phytochemical investigation of the roots of Glehnia littoralis Fr. Schmidt. ex Miq. led to the isolation of 16 known compounds, including three ß-carboline alkaloids (1-3), four phenylpropanoids (4-7), five phenolic acids (8-12), three polyacetylenes (13-15) and one fatty acid (16). The structures of these compounds were elucidated on the basis of spectral analysis and comparison with those reported in literatures. To the best of knowledge, the report of the first ß-carboline alkaloid in the Umbelliferae family. Additionally, compounds 1-5, 9, 10 and 16 have not been reported from any species in Umbelliferae family, compounds 7, 8 and 12 were isolated from the genus Glehnia for the first time and could be of the chemotaxinomic significance and serve as valuable chemotaxonomic makers for G. littoralis. The chemotaxonomic significance of the isolated compounds was summarised.

Tracking the magnetic carriers of heavy metals in contaminated soils based on X-ray microprobe techniques and wavelet transformation.

Technogenic magnetic particles (TMPs) from industrial activities are major contamination sources of soils and dusts because they usually carry large amounts of heavy metals. The understanding of the association between TMPs and heavy metals in contaminated soils helps to trace the polluting sources and probing into the mechanism of magnetic phases enriched with heavy metals. In this study, we tracked the magnetic carries of heavy metals from different emission sources in steel industrial regions by using the synchrotron-based probe techniques and multiscale analytical methods. The µ-XRF mapping showed that TMPs contained various heavy metals, depending on their sources. The Fe K-edge µ-XANES revealed that the ferroalloy, pyrrhotite and TMPs in steel slag and coal ash were major magnetic phases in contaminated soils. Their relative content varied differently at the microscale. The multiscale analysis revealed that the heavy metals associated with magnetic phases exhibited pronounced scale dependence, depending on the size, type, and assemblage of different magnetic phases. Multiscale source apportionment revealed that the contamination sources varied differently at multiple scales. Heatmap analysis revealed that at 8-µm scale, Co, Cr, Cu and Mn were mainly derived from ferroalloy, while Ti, Zn and As from both ferroalloy and TMPs from coal ash.

Underlying Promotion Mechanism of High Concentration of Silver Nanoparticles on Anammox Process.

Silver nanoparticles (AgNPs) are largely discharged into sewers and mostly accumulated in the sediments and sludge. The toxicity of AgNPs to environmental microorganisms has attracted great attention. However, the effect of AgNPs on anaerobic ammonium-oxidizing (anammox) granules remains unknown. Here we present the underlying promotion mechanism of AgNPs on anammox granules from a morphological and molecular biology perspective. Our results demonstrate a positive effect of AgNPs on the proliferation of anammox bacteria. AgNPs resulted in a change in the three-dimensional structure of anammox granules and led to larger pore size and higher porosity. In addition, the diffusion capacity of the substrate and metal ions was enhanced. Furthermore, the expression of anammox-related enzymes, such as nitrite oxidoreductase (NirS), hydrazine dehydrogenase (Hdh), and hydrazine synthase (HZS), was upregulated. Therefore, the growth rate and the nitrogen removal performance of the anammox granules were improved. Our findings clarify the underlying mechanism of AgNPs on anammox granules and provide a promising method for the treatment of AgNPs-rich wastewater.

Modification of microcrystalline cellulose with acrylamide under microwave irradiation and its application as flocculant.

Grafting polyacrylamide (PAM) chains onto microparticles may combine the advantages of the flocculation property of the former and the fast sedimentation of the later to realize better flocculation performance. In this work, inexpensive microcrystalline cellulose (MCC) microparticles, and monomer of acrylamide (AM) were mixed, and then irradiated under microwave. The obtained material was characterized by Fourier transform infrared spectroscopy and X-ray diffraction, and the results demonstrated successful modification of MCC with AM on the particle surface. The modification procedure has been carefully investigated to obtain an optimum preparation condition. Kaolin suspension was selected as a model to evaluate the flocculation properties of the obtained AM-MCC. Our results indicate that the AM-MCC with the highest grafting ratio of 95.5% exhibits the best flocculation performance, which is even better than that of PAM, and the turbidity can be decreased to 1.4% of the naked kaolin suspension within 2.5 min. Therefore, this work provides a low cost strategy to prepare biodegradable AM-MCC, which may have promising potential application in the water treatment and other fields.