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A synthetic Schlieren method is developed to measure the density field of a stratified fluid. A transparent sheet of background markers is attached on one side of a tank which is made of acrylic plates, and a camera is positioned on the opposite side of the tank. The markers are virtually displaced due to light refraction in the stratified fluid in the tank, in reference to those from the water tank. The governing equation is derived based on the observation that the marker displacements depend on the light refraction at the interface of media, the refractive indices of the transparent liquids and their spatial gradient. The density of the fluid is associated with the refractive index via the relationship obtained in a calibration process. We solve this governing equation, an over-determined system with only the target variable unknown, using the optimization method. We examine the present method by performing laboratory experiments for two cases of the density stratification, i.e., a linear stratification and a pycnocline. We also carry out ray tracing simulations of three characteristic density profiles (i.e., a linear stratification, a nonlinear stratification and a pycnocline). The present method is compared with the method of solving the Poisson equation in detail, emphasizing the difference between the two methods. Measurement uncertainty is discussed at last. • A synthetic Schlieren method is developed to measure the density of a stratified fluid. • The over-determined governing equations are solved by the optimization method. • The present method is verified by laboratory experiments and simulations. • The comparison with the Poisson-equation method is discussed in detail. [ABSTRACT FROM AUTHOR]

The content, composition and molecular signatures of soil organic matter (SOM) have important influences on the cycle of soil organic carbon (SOC) and the partitioning of polycyclic aromatic hydrocarbons (PAHs) in soil. Seventy-nine soil samples from farmland, forest and urban areas were collected in Shenyang, China to investigate black carbon (BC) content, SOM molecular signatures varied with land use patterns, as well as the relationship with PAHs. The content of BC in urban soils was significantly higher than that of farmland and forest. BC was a key contributor of urban SOM which accounted for 0.35 ± 0.31 of SOC in urban soil. Based on BC/SOC ratio, the main sources of BC were identified as fossil fuel combustion for urban soils, while for farmland and forest soils, it is the mixed results of fossil fuel combustion and biomass burning. All categories of PAHs in urban soils showed the highest level compared to farmland and forest soils. Pearson's correlation analysis results showed there were significant positive correlations between BC and PAHs categories in urban soils, indicating the important role of BC in the accumulation of PAHs in soil. SOM from each of the two different land use patterns can be distinguished by molecular signatures. Urban SOM had abundant molecular markers derived from condensed organic carbon inputs, which was consistent with the BC/SOC value. Farmland SOM had abundant carbon from vegetation and microorganisms, and forest SOM was rich in organic carbon from fresh plant materials. The markers enriched in urban SOM showed significant correlations with most PAHs categories, highlighting the affinity of urban SOM for PAHs at the molecular level. This study contributed to understanding the impact of land management methods on SOM molecular composition signatures and its influence on PAHs occurrence in soil, providing a theoretical basis for regional soil pollution management. [Display omitted] • Urban soils had high levels of BC and PAHs. • PAHs show significant positive correlations with BC and SOC in urban soils. • Molecular signatures of SOM vary significantly with land use in Shenyang. • SOM molecular signatures affect PAHs accumulation in soil. [ABSTRACT FROM AUTHOR]

Lead chromate pigments are commonly used yellow inorganic pigments. They can pose environmental risks as they contain toxic heavy metals lead and chromium. Low molecular weight organic acids (LMWOAs), as widespread dissolved organic matter (DOM), affect the lead and chromium release from the pigment in water. In this work, the role of LMWOAs in the photodissolution of commercial lead chromate pigment was investigated. The pigment underwent significant photodissolution under simulated sunlight exposure with LMWOAs, and subsequently released Cr(III) and Pb(II). The photodissolution process is caused by the reduction of Cr(VI) by photogenerated electrons of the lead chromate pigment. The LMWOAs promoted photodissolution of the pigment by improving the electron-hole separation. The formation of Cr(III)-contained compounds leads to a slower release of chromium than lead. The photodissolution kinetics increase with decreasing pH and increasing LMWOAs concentration. The photodissolution of lead chromate pigment was basically positively related to the total number of hydroxyl and carboxyl groups in LMWOAs. The LMWOAs with stronger affinity to lead chromate pigment, lower adiabatic ionization potential (AIP) and higher energy of the highest occupied molecular orbital (E HOMO) are favorable to Cr(VI) reduction by photogenerated electrons and pigment photodissolution. 2.39% of chromium and 10.34% of lead released from the lead chromate pigment in natural conditions during a 6-h sunlight exposure. This study revealed the photodissolution mechanism of lead chromate pigment mediated by LMWOAs with different molecular structures, which helps understand the environmental photochemical behavior of the pigment. The present results emphasize the important role of DOM in the heavy metals release from commercial inorganic pigments. [Display omitted] • LMWOAs significantly promoted the release of lead and chromium from the pigment. • Reaction kinetics followed the order: citric > tartaric > malic > oxalic > formic acid. • LMWOAs improved the separation of photogenerated electron-hole of the pigment. • Electron donating power of LMWOAs and adsorption controlled photodissolution. [ABSTRACT FROM AUTHOR]

In a synthetic Schlieren method of measuring the height of a dynamic free liquid surface, the smallest wavelength of the measured surface topography is determined by the spatial resolution of the displacement field of markers. Currently, a displacement vector is obtained for each interrogation window, including a few markers, with a cross-correlation algorithm. In this study, the measurement resolution is extended by obtaining the displacement of individual markers. This simple and rational change, however, brings technical difficulties in numerically solving the governing equation over spatially randomly distributed markers. For this, the governing equation, which associates the surface height to be measured with the virtual displacements of the markers, is solved by the finite-volume scheme for the unstructured meshes, where a marker locates at the center of each triangular mesh face. The present method is examined with the synthetic generated data, in laboratory experiments of a transparent solid carved with a sinusoidal surface, and in experiments of water ripples. The measurement uncertainty is discussed. • The finite-volume scheme is used in synthetic Schlieren to measure free surfaces. • Our method takes advantage of using marker-marker resolution in the pattern. • The present method may resolve smaller topographic structures of the surface. [ABSTRACT FROM AUTHOR]

Atrazine (ATR), one of the most widely used pesticides in agricultural production, are gradually concerned due to potential ecosystem and health risks. Further, the induction of ATR nephrotoxicity and detoxification response is still unknown. To evaluate ATR-induced nephrotoxicity, quails were treated with 0, 50, 250 or 500 mg/kg ATR by gavage administration for 45 days. Histopathology indicated that ATR exposure caused renal tubular epithelial cell swelling and endoplasmic reticulum degeneration, suggesting that ATR exposure causes renal impairment even renal diseases. Notably, ATR interfered cytochrome P450 system (CYP450s) homeostasis by enhancing contents or activities of CYP450s (total CYP450, Cyt b 5, AH, APND, NCR and ERND) and the expression of CYP450 isoforms (CYP1A, CYP1B, CYP2C and CYP3A). ATR triggered phase II detoxifying reaction, reflected by the elevated GSH level, GST activity and the up-regulation of GST isoforms (GSTa, GSTa3 and GSTt1) and GSH synthetase (GCLC). Moreover, ABC transporters were activated to expel ATR from the body by increasing expression of MRP1 and P-GP gene. Accompanying these alterations, the nuclear receptors (AHR , CAR and PXR) were activated by ATR in a dose-dependent manner. Analysis results of present study demonstrated that the induction of phase II detoxifying enzyme system and ABC transporters could be modulated by nuclear receptors response and CYP450s disturbance in low-dose ATR-treated quail. In conclusion, all data suggested that nuclear receptors AHR-mediated detoxification pathway was involved in ATR-induced nephrotoxicity. These results provided new evidence about the nephrotoxic effects of ATR on the response of biotransformation and detoxification system. Atrazine (ATR) and its metabolites in environment are considered key determinants. Our findings provide evidence that ATR has toxic effect of kidney via inducing the kidney injury. Phase II detoxifying reaction and ABC transporters are modulated by nuclear receptors response and CYP450s disturbance to participate in the detoxification of ATR. AHR-mediated detoxification pathway involves in atrazine-induced nephrotoxicity. Image 1 • ATR induces the renal injury in quail. • ATR triggers nuclear receptor response in the kidney. • ATR causes CYP450 imbalance and phase Ⅱ detoxification and ABC transporter reaction. • AHR-mediated detoxification pathway involves in ATR-induced nephrotoxicity. Nuclear receptor AHR-mediated xenobiotic detoxification pathway involves in nephrotoxic effects of atrazine in quail. [ABSTRACT FROM AUTHOR]

[Display omitted] • For the first time, caffeine was found to stimulate the production of Irisin in skeletal muscle. • Caffeine activates calcium signaling pathway and PGC-1α in skeletal muscle to produce Irisin. • Irisin is critical in adiposity reduction by caffeine via skeletal muscle-adipose crosstalk. With the progress of modern society, obesity has gradually emerged as a major public health challenge. In recent years, there has been growing interest in the potential of caffeine (CAF) as a nutritional tool for combating obesity. While previous studies has demonstrated CAF's ability to directly influence white adipose tissue (WAT) by promoting browning and reducing obesity, the role of muscle in obesity reduction should not be overlooked. Given that exercise is a primary component of weight loss, our study aimed to investigate whether CAF can alleviate adiposity by modulating the skeletal muscle–adipose tissue crosstalk. Our study demonstrates that CAF can alleviate obesity by enhancing the expression of PGC-1α through calcium-related signaling pathways in skeletal muscle, which subsequently induces the production of Irisin in myotubes and high fat diet (HFD)-fed mice in vitro. Irisin, in turn, circulates to WAT and promotes browning, thus providing a theoretical foundation for the use of CAF as a nutritional tool for weight control. Overall, our findings highlight the potential of CAF in modulating skeletal muscle–adipose tissue crosstalk and suggest that it may be an effective tool for reducing obesity. [ABSTRACT FROM AUTHOR]

Abstract Herein, a schematic model was established to assess the combined effect of deposited CaCO 3 and thermophilic sulfate-reducing bacteria (SRB), at high CO 2 and low O 2 dissolution levels on the corrosion behavior and growth of corrosion scale on X65 pipeline carbon steel. Field emission scanning electron microscopy, energy-dispersive spectrometry, X-ray diffraction, confocal laser scanning microscopy, open circuit potential, and electrochemical impedance spectroscopy were used to characterize the corrosion pattern of water injection pipe. The results showed that a synergistic effect exists between CaCO 3 and thermophilic SRB, both uniform and localized corrosion of CaCO 3 -coated X65 steel were promoted when inoculated with SRB. The corrosion process was comprised of three stages depending on the metabolism of SRB. Highlights • A synergistic effect exists between deposited CaCO 3 and thermophilic SRB. • Both uniform and localized corrosion were promoted when CaCO 3 and SRB coexisted. • The development of corrosion comprises three stages depending on the metabolism of SRB. • A schematic model was proposed to describe the corrosion development. • Corrosion would be further promoted with the continuous injection of SRB. [ABSTRACT FROM AUTHOR]

Future space missions are considering the use of green space propulsion, and H 2 O 2 /kerosene bipropellant is one of effective alternatives for rocket propellant. In addition, for a 100-N-class thruster of H 2 O 2 /kerosene, it is important to design the proper injector. In this study, according to different values of the geometric constant A which determines the initial swirl intensity of the injected fluid, five coaxial swirl injectors are designed to check the thruster's performance. From the test and experiment results, it is found that with an increase in A , coaxial-swirl injectors can aid in the mixing of oxidant and fuel but increase the average temperature of faceplate, thus significantly reducing the flame length. However, a large or small value of A is not conductive to improve the combustion efficiency. In addition, the pressure oscillation ( P ins ) inside of the chamber gradually becomes intense. Among all cases, Case 3 ( A = 3.0 ), exhibits optimal performance for a 100-N-class H 2 O 2 /kerosene thruster. [ABSTRACT FROM AUTHOR]

Mixed contamination of nitrate and antibiotics/antibiotic-resistant genes (ARGs) is an emerging environmental risk to farmland soil. This is the first study to explore the role of excessive anthropogenic nitrate input in the anoxic dissipation of soil antibiotic/ARGs. During the initial 10 days of incubation, the presence of soil antibiotics significantly inhibited NO 3 − dissipation, N 2 O production rate, and denitrifying genes (DNGs) abundance in soil ( p < 0.05). Between days 10 and 30, by contrast, enhanced denitrification clearly prompted the decline in antibiotic contents and ARG abundance. Significantly negative correlations were detected between DNGs and ARGs, suggesting that the higher the DNG activity, the more dramatic is the denitrification and the greater are the antibiotic dissipation and ARG abundance. This study provides crucial knowledge for understanding the mutual interaction between soil DNGs and ARGs in the enhanced anoxic denitrification condition. [ABSTRACT FROM AUTHOR]

[Display omitted] • Hierarchical porous iron–nitrogen-carbon electrocatalysts were successfully synthesized using conjugated microporous polytriphenylamine network with the impregnation of FeCl 3. • The Fe doping content and pyrolysis temperature can be used to tailor the structure and electrocatalytic performance of electrocatalyst. • The optimized electrocatalyst showed an enhanced ORR performance and methanol tolerance compared to Pt/C catalyst. Iron-nitrogen-carbon catalysts are promising non-precious metal-based electrocatalysts for oxygen reduction reaction (ORR) used in fuel cells. However, the rational design and fabrication of iron–nitrogen-carbon catalysts with tunable ORR activity remain challenging. Herein, iron–nitrogen-enriched carbon materials (FeNCs) were produced using the precursor of pyridyl conjugated microporous polytriphenylamine with the impregnation of FeCl 3 via two cycles of high-temperature pyrolysis with acid leaching in-between. The Fe doping content and pyrolysis temperature were varied to manipulate the state of active sites, the degree of graphitization and electrocatalytic performance. The optimized FeNCs exhibit enhanced stability, methanol tolerance and superior ORR activity in alkaline media with a higher onset potential (0.990 V vs RHE), half-wave potential (0.878 V vs RHE) and diffusion current density J L (5.95 mA cm−2) compared to commercial Pt/C catalyst (0.974 V, 0.860 V, 5.10 mA cm−2). The excellent electrocatalytic performance is ascribed to the co-existing highly active sites of Fe 4 N and Fe 3 C, the hierarchical porous structures for full action of active sites and a high surface area (1397 m2 g−1) with defect engineered graphitic and amorphous carbon for efficient electron conduction of ORR. Accordingly, the high-performance FeNCs can become an alternative low-cost catalyst to precious Pt/C catalyst for fuel cells. [ABSTRACT FROM AUTHOR]

Organic fouling caused by dissolved organic matter (DOM) is a critical challenge for membrane technologies. In this study, prediction models for the fouling of commercial polyether sulfone (PES) and regenerated cellulose (RC) ultrafiltration membranes by DOM were established based on the hydrophobicity of DOM. The organic fouling behavior of 40 natural water samples collected from Lake Taihu was investigated. The fouling propensity of water samples on ultrafiltration membranes was evaluated using the fouling index (FI). The hydrophobicity of DOM in water samples was quantified by its partition coefficient in an aqueous two-phase system (K ATPS). The FI of water samples on RC membranes was lower than that on PES membranes due to stronger repulsive Lewis acid-base interactions, which reduced DOM-membrane interactions. A significant positive correlation was found between K ATPS and FI, suggesting the important role of DOM hydrophobicity in the organic fouling of ultrafiltration membranes. FI prediction models using K ATPS as the variable were established using a training group containing 20 water samples for PES and RC membranes, respectively. The resulting models were then validated using the additional 20 water samples, which suggested good prediction power (RMSE = 1.65). The pH effect on the organic fouling can be adequately predicted by the same model with K ATPS values measured at given pH. The results suggest that K ATPS can be used as a convenient index for assessing the initial organic fouling of ultrafiltration membranes by freshwater DOM. [Display omitted] • Partition coefficient of DOM in ATPS (K ATPS) was used to scale its hydrophobicity. • K ATPS significantly correlates with the fouling index of DOM on UF membranes. • DOM hydrophobicity plays an important role in the organic fouling of UF membranes. • Prediction models were established and validated for organic fouling of UF membranes. • The pH effect on the organic fouling can be explained using these prediction models. [ABSTRACT FROM AUTHOR]

Inhomogeneous refractive index fields lead to errors in optical flow velocity measurements. Former respective studies are mostly in quasi two-dimensional flows, and attribute the measurement errors to spatial gradients in the refractive index field, while less attention has been paid to flows with three-dimensional refractive index fields which usually change in space and in time. In this study, ray tracing simulations were carried out in a three-dimensional flow, which is from a direct numerical simulation of single-phase turbulent mixing of two fluids. Given the data of the numerical simulation as reference, the ray tracing simulation is used to quantify the measurement errors of the flow velocity and flow acceleration for tracer-based velocimetry, i.e. particle tracking velocimetry in this study. The errors of both flow velocity and flow acceleration are attributed to the spatial and the spatio-temporal gradients of the refractive indices, respectively, which are closely inherited from flow characteristics. While the dominant type of error depends on the studied flow, the main measurement error for the considered turbulent mixing flow is caused by the random error. When the maximum spatial difference of the refractive indices is about 1 0 − 6 , the relative random measurement error is about 1 % in velocity and about 200 % in acceleration, respectively. When the maximum index difference is about 1 0 − 2 (water), the relative random measurement errors of velocity and acceleration are 2000 % and 1 0 5 %, respectively, for the flow considered in this study. [Display omitted] • Ray tracing simulations were carried out to quantify PTV measurement errors. • The refractive index field was obtained from the density data of a DNS dataset. • The maximum spatial difference of refractive indices ranges from 1 0 − 6 to 1 0 − 2 . • The random error is the dominant for the velocity and acceleration for the studied flows. • The velocity error is associated with spatio-temporal gradients of refractive indices. [ABSTRACT FROM AUTHOR]

Co-contaminated soils by organic pollutants (OPs), antibiotics and antibiotic resistance genes (ARGs) have been becoming an emerging problem. However, it is unclear if an interaction exists between mixed pollutants and ARG abundance. Therefore, the potential relationship between OP contents and ARG and class 1 integron-integrase gene ( intI 1) abundance was investigated from seven dairy farms in Nanjing, Eastern China. Phenanthrene, pentachlorophenol, sulfadiazine, roxithromycin, associated ARG genes, and intI 1 had the highest detection frequencies. Correlation analysis suggested a stronger positive relationship between the ARG abundance and the bioaccessible OP content than the total OP content. Additionally, the significant correlation between the bioaccessible mixed pollutant contents and ARG/ intI 1 abundance suggested a direct/indirect impact of the bioaccessible mixed pollutants on soil ARG dissemination. This study provided a preliminary understanding of the interaction between mixed pollutants and ARGs in co-contaminated soils. [ABSTRACT FROM AUTHOR]

Neonatal hypoxic ischemic encephalopathy (HIE) is a main factor of neonatal death and permanent neurologic deficit. This study sought to investigate the functional role of hsa_circ_0007706 (circ_0007706) in modulating neonatal HIE. In vitro HIE cell model was established in hBMVECs under the condition of oxygen‑glucose deprivation/reperfusion (OGD/R) treatment. qRT-PCR analysis was utilized for detecting the level of circ_0007706, microRNA-579–3p (miR-579–3p) and TNF receptor-associated factor 6 (TRAF6). RNase R treatment and Oligo (dT) 18 primers were employed to verify the features of circ_0007706, and nucleocytoplasmic separation was conducted for determining the location of circ_0007706. CCK-8 assay, EdU assay, and flow cytometry were carried out to measure cell proliferation and apoptosis, respectively. The protein expression of Bax, Bcl-2 and TRAF6 was detected using western blot. Meanwhile, the levels of the pro-inflammatory factors were determined via ELISA. SOD activity and MDA level were assessed via the respective kits. Besides, dual-luciferase reporter assay and RNA pull-down were used to identify the association between miR-579–3p and circ_0007706 or TRAF6. Circ_0007706 was elevated in HIE newborns and OGD/R cell model. Knockdown of circ_0007706 greatly alleviated OGD/R-induced injury, inflammatory response and oxidative stress. We found that miR-579–3p was a direct target of circ_0007706, and miR-579–3p inhibitor could reverse the impact of circ_0007706 knockdown on OGD/R-caused cell damage in hBMVECs. In addition, miR-579–3p directly interacted with TRAF6, and the protective effects of miR-579–3p on OGD/R-induced injury in hBMVECs were harbored by TRAF6 overexpression. Our data indicated that circ_0007706 knockdown could downregulate the expression of TRAF6 by sponging miR-579–3p in OGD/R-treated hBMVECs. This study demonstrated that circ_0007706 knockdown assuaged HIE-induced injury by decreasing TRAF6 expression via targeting miR-579–3p. • Circ_0007706 was upregulated in HIE newborns and OGD/R-induced hBMVECs. • Circ_0007706 downregulation alleviated OGD/R-induced damage in hBMVECs. • Circ_0007706 downregulation mitigated OGD/R-induced damage via targeting miR-579–3p to regulate TRAF6 expression in hBMVECs. [ABSTRACT FROM AUTHOR]

The effects on the growth of tomato seedlings and cadmium accumulation of earthworm mucus and a solution of amino acids matching those in earthworm mucus was studied through a hydroponic experiment. The experiment included four treatments: 5 mg Cd L−1 (CC), 5 mg Cd L−1 + 100 mL L−1 earthworm mucus (CE), 5 mg Cd L−1 + 100 mL L−1 amino acids solution (CA) and the control (CK). Results showed that, compared with CC treatment, either earthworm mucus or amino acids significantly increased tomato seedling growth and Cd accumulation but the increase was much higher in the CE treatment compared with the CA treatment. This may be due to earthworm mucus and amino acids significantly increasing the chlorophyll content, antioxidative enzyme activities, and essential microelement uptake and transport in the tomato seedlings. The much greater increase in the effect of earthworm mucus compared with amino acid treatments may be due to IAA-like substances in earthworm mucus. [Copyright &y& Elsevier]

Abstract A novel UV-shielding film created by sputtering ZnO film onto a renewable and biodegradable cellophane film is proposed. The dependence of the optical properties of the ZnO/cellophane hybrid film on the sputtering power, pressure, and film thickness was studied systematically. A high crystalline quality ZnO film with preferred [002] orientation was prepared on a cellophane substrate for the first time. Unlike conventional UV-shielding films consisting of nanostructures and synthetic polymers, ZnO/cellophane hybrid film can possess high visible light transparency and excellent UV-shielding capacity at the same time. The improved performance can be attributed to the high crystalline quality and the antireflection effect of the ZnO film. A typical hybrid film exhibits a UV-shielding ratio of 96.5% while exhibiting a transmittance of visible light of over 80%. ZnO/cellophane hybrid films can be applied in a vast range of UV-shielding applications, such as sunburn protection and short-wave radiation protection in the laboratory. Graphical abstract fx1 [ABSTRACT FROM AUTHOR]

Abstract: The effect of earthworms on humus composition and humic acid (HA) characteristics was studied in a rice–wheat rotation agroecosystem. Experimental plots in the rotation had five treatments, i.e., incorporation or mulching of maize residues with or without added earthworms and a control. Compared with the control, the application of maize residues to soil either alone or in combinations with earthworms strongly affected the humus composition and HA characteristics. In the presence of earthworms, the carbon ratio of HA to fulvic acid (FA), and the alkyl C/O-alkyl C and hydrophobic C/hydrophilic C ratios of HA were slightly higher, while the aliphatic C/aromatic C ratio of HA was slightly lower following maize residue incorporation than the same treatment without earthworms. In contrast, these ratios generally remained almost constant following maize residue mulching. Thus, earthworm activity following maize residue incorporation was more favorable for the HA formation, and was associated with a decrease in aliphaticity of HA, and an increase in its degree of humification and hydrophobicity. [Copyright &y& Elsevier]

Abstract: A 16.6-kilo-base pair (kb) sequence was amplified from the duck enteritis virus (DEV) clone-03 strain genome using ‘targeted gene walking polymerase chain reaction (PCR)’. Seven complete open reading frames (ORFs) were predicted, and designated herpes simplex virus 1 (HSV-1) homologues, unique long (UL) 25, UL26, UL26.5, UL27, UL28, UL29, and UL30. Sequence analysis revealed that the arrangement of seven genes in DEV clone-03 strain was collinear to that from HSV-1. In addition, mRNA transcription orientation was identical to the HSV-1 genes. While UL25, UL26, and UL26.5 shared the same poly A signal, the UL27 and UL28 genes overlapped by 211bp nucleotides and shared the same 3′ transcription terminus. UL26.5, an in-frame ORF of UL26, was co-terminal with UL26 at its 3′-end. We predicted that the gene arrangement in the unique long segment of the DEV clone-03 was identical to that in HSV-1, particularly in the region from UL25 to UL30 gene. Phylogenetic trees of the putative proteins encoded by these seven genes showed that UL27, UL28, and UL30 had a close evolutionary relationship with the Mardivirus, however, the other four proteins exhibited close relationships with the Simplexvirus or Varicellovirus, indicating that the DEV clone-03 should be placed into a single cluster within the subfamily Alphaherpesvirinae. [Copyright &y& Elsevier]

Earthworms naturally secrete substantial amounts of mucus (relative to their body size) from the cuticle when moving through the soil. However, how the metabolites in the epidermally derived mucus affect soil microfauna is largely unknown. The objective of this study was to determine how earthworm mucus affected the physiology of the model nematode Caenorhabditis elegans and that of two soil-dwelling bacterial-feeding nematodes: Mesorhabditis sp. and Protorhabditis sp. The traits examined included phobotaxis, reproduction, mortality, body size, feeding inhibition rate, and feeding preference. Two nematode species escaped from the earthworm mucus, whereas earthworm mucus reduced the reproduction of C. elegans and increased the mortality of C. elegans and Mesorhabditis sp. Moreover, earthworm mucus reduced the feeding rate of C. elegans and Protorhabditis sp. and changed the feeding preferences of all three species of nematodes. At 48 h, earthworm mucus increased feeding on Bacillus amyloliquefaciens JX1 for C. elegans and Protorhabditis sp. and reduced feeding on Escherichia coli OP50 for Mesorhabditis sp. These results suggest that earthworm mucus can be detrimental to bacterial-feeding nematodes and provide insights into the non-trophic interactions between earthworms and other soil biota. • Two of the three bacterial-feeding nematodes escaped from earthworm mucus. • Earthworm mucus reduced the reproduction of C. elegans. • Earthworm mucus increased the mortality of the C. elegans and Mesorhabditis sp. • Earthworm mucus inhibited the feeding rate of C. elegans and Protorhabditis sp and changed the feeding preferences of all the bacterial-feeding nematodes. [ABSTRACT FROM AUTHOR]

Fowl adenovirus serotype 8b (FAdV-8b), as causative agent of inclusion body hepatitis (IBH), poses a great threat to the poultry industry. Considering the importance of innate immune response in host against viral infections, we investigated pathogenicity of a FAdV-8b strain HLJ/151129 in 1-mo-old specific pathogen-free (SPF) chickens and immune responses of host to FAdV-8b infection in this study. The results demonstrated that no obvious clinical signs were observed in infected birds. Neither mobility nor mortality was observed in both FAdV-8b infected and control chickens, as well. However, hepatic necrosis and a small amount of inflammatory cell infiltration were observed by pathological analysis. Viral load was detected in bursa of Fabricius, cecal tonsils, liver, heart, spleen, Harderian glands, and thymus. Virus shedding and viremia generated as early as 3 days postinfection (dpi) (9/10) and reached the peak at 7 dpi (10/10). In addition, the infected birds had developed FAdV-specific antibodies at 7 dpi, and the antibody titers reached the peak at 14 dpi. Furthermore, the results demonstrated that the mRNA expression levels of most of toll-like receptors ( TLRs ), most of avian β-defensins ( AvBDs ), and cytokines [interleukin ( IL )-2, IL-6 , and interferon ( IFN )-γ], were significantly upregulated in most tissues at early phases of FAdV-8b infection, especially in liver and spleen. In contrast, FAdV-8b infection results in downregulation of TLR4, TLR5 , and TLR21 expressions in some tissues of infected chickens. In addition, FAdV-8b infection upregulated myeloid differentiation factor 88 ( MyD88 ), nuclear factor-kappa B ( NF-κB ) p65, and TIR-domain-containing adapter inducing interferon-β ( TRIF ) expression in some tissues, while decreased NF-κB p65 and TRIF in spleen at both 72 hpi and 21 dpi. Taken together, these results confirmed that FAdV-8b could replicate in all investigated tissues of infected birds, and then, result in production of FAdV-specific antibody titers. Meanwhile, the FAdV-8b infection induces strong innate immune responses at early stage in chickens, which may associate with the viral pathogenesis. [ABSTRACT FROM AUTHOR]

Abstract Cadmium (Cd) and benzo [ a ]pyrene (BaP) often co-occur in the environment, and the critical body residue of organisms is used as an indicator of the toxic effects of contaminants. However, little is known about their distributions and toxicities when pollution of Cd and BaP are combined. Semi-static solution culture experiment was used to study the impacts of BaP on the subcellular distribution of the toxic metal Cd in the earthworm Eisenia fetida. We explored the mechanisms by which this organism responds to combined exposure to these pollutants by measuring the protein content of each of three subcellular fractions, as well as acetylcholinesterase (AChE) and glutathione S-transferase (GST) activities. The subcellular partitioning of Cd was heterogeneous and Cd mainly accumulated in the cytosolic fraction (Fraction C), which was previously reported to be involved in metal immobilization. In Fraction C, Cd accumulation was correlated with the external concentration to which the earthworm had been exposed; however, in the presence of BaP, Cd accumulation was inhibited and plateaued at high external Cd concentrations. A principal component analysis revealed that this decreased Cd accumulation might be caused by increases in GST activity, which likely increased the excretion of Cd. BaP was also found to stimulate protein biosynthesis and upregulate AChE and GST activities in the debris fraction (Fraction E), indicating other potential detoxification mechanisms in this fraction. Granule fraction (Fraction D) had a lower protein content, AChE and GST activities than the other subcellular fractions, supporting previous findings that Fraction D is largely inert. Graphical abstract Image 1 Highlights • Cadmium (Cd) subcellular partitioning is heterogeneous. • Benzo [ a ]pyrene (BaP) inhibits Cd accumulation. • BaP promoted the production of total protein in the cellular debris fraction. • Glutathione S-transferase (GST) is the main influencer of Cd accumulation. [ABSTRACT FROM AUTHOR]

Bio-fertilizers are thought to be overwhelmingly superior to chemical fertilizers for the improvement of soil quality and productivity. However, the comprehensive effects of bio-fertilizer on the soil ecosystem and the possibility of using multiple soil beneficial biota are still not well understood. A two-year field study was conducted to examine how crop yield, soil biochemical properties, enzyme activities, and functional diversity responded to different bio-fertilizers in the sweet potato phase of a double-cropping system (sweet potato and rapeseed). Six fertilizer treatments, including one chemical treatment (CF), two organic treatments (OM, organic manure; MC, organic manure plus chemical fertilizer) and three bio-fertilizer treatments (MCN containing nematodes, MCE containing earthworms, and MCP containing phosphate-solubilizing bacteria) were compared. The soils under CF had the lowest values for all soil parameters in comparison with the other treatments. Among the organic and bio-fertilizer treatments, OM performed better in improving soil biological properties such as soil respiration and microbial biomass, while soils under all these treatments had similar soil enzyme activities and functionality. Crop yield was positively correlated with soil nutrient levels, microbial biomass and enzyme activity, and most of the biochemical variables were highly intercorrelated. Our results indicated that organic fertilizers and bio-fertilizers were superior to chemical fertilizers and generally improved soil quality and productivity to similar levels in the field. [ABSTRACT FROM AUTHOR]

This work presents an upgraded one-dimensional (1D) nonlinear rheological system of soft ground consolidation. In the system, the boundaries are characterized by the time-dependent drainage boundary conditions at the surface and bottom of the layer. Meanwhile, the modified UH relationship and non-Newtonian index flow model are used to simulate the viscous effect of clay and the flow of excess pore-water during consolidation, respectively. Then, two numerical discretization formats of the system, namely the finite volume method (FDM) and finite difference method (FVM), are given, and corresponding calculation programs are compiled. The model solutions have been validated by degraded analytical solutions, FDM and FVM comparison solutions, and available laboratory data. Further, the consolidation behaviour under different model parameters is illustrated. The calculated results indicate that the change of interface parameters and flow mode does not influence the final foundation settlement, but both significantly affect the overall dissipation process of EPWP of soils. At last, an efficient method for determining CDB parameters is proposed and verified by available test data. [ABSTRACT FROM AUTHOR]

Considering the non-linear creep characteristics of clays, the modified unified hardening (UH) relation is employed to reflect the visco-elastic-plastic deformation of soft soils. Simultaneously, Swartzendruber's flow in the form of a continuous function is captured to describe pore water flow through pores during consolidation. Thus, an upgraded one-dimensional (1-D) non-linear rheological consolidation (NRC) system of clays has been established, and its solutions are conducted using the finite volume method (FVM). Through comparisons against the theoretical solutions and laboratory test results, the effectiveness of the numerical algorithm and applicability of the modified UH relation is verified. Then, the effects of model parameters on non-linear rheological consolidation behavior were studied. The results indicate that ignoring the time effect of secondary consolidation coefficient overestimates the overall consolidation and settlement proceeding, and considering the viscous effect of the soils led to an unanticipated increase in excess pore-water pressure (EPP) at the initial loading period. Meanwhile, the rising EPP becomes more pronounced with the increase of the initial over-consolidated parameter, flow parameter, and soil thickness or the decrease of overlying load. Additionally, FVM and finite difference method (FDM) solutions, as well as the application scope of Darcy's law in the NRC system, are discussed. [ABSTRACT FROM AUTHOR]

Sustainable agriculture aims to manage soil and plant health while relying less on chemical inputs. The individual effect of organic amendments or resistant crop cultivars on the suppression of root pests through modulating soil and plant performance is being well documented. However, the interactions between organic amendments and crop cultivars are less well studied. A pot experiment was conducted across two tomato cultivars of distinct resistance to root-knot nematodes (RKNs, Meloidogyne incognita ) with three amendments including inorganic fertilizer (IF), conventional compost (CC) and vermicompost (VC). All treatments were inoculated with second-stage juveniles of M. incognita to simulate the root-knot nematode disease in field condition and to focus on the comparison among different soil amendment effects. Plant growth (shoot height, shoot biomass, root biomass and root C:N ratio), root defense metabolites (phenolics) and their related genes expression, and soil properties including pH, electrical conductivity, available nutrients, 3-indoleacetic acid (IAA), microbial biomass and activity were analyzed at 14 and 30 days post inoculation (dpi). Compared with inorganic fertilizer, vermicompost significantly decreased the numbers of nematode-induced galls on susceptible (Sus) and resistant (Res) cultivar roots by 77% and 42% respectively at 14 dpi, and by 59% and 46% respectively at 30 dpi. Vermicompost also significantly increased root defense metabolite concentrations, defense related gene expression, and improved soil properties ( p < 0.05) except for mineral nitrogen. Multivariate analyses further indicated that soil properties particularly pH, root primary and secondary defense metabolites were negatively associated with root gall. Moreover, soil microbial activity, pH and IAA concentration were the main soil properties positively associated with plant defense metabolites production and biomass for both susceptible and resistant cultivars. Overall, vermicompost could significantly suppress root pests via modulating soil properties as well as plant defenses, particularly for the susceptible plant. [ABSTRACT FROM AUTHOR]

As a representative of tumor immunotherapy, tumor vaccine can inhibit tumor growth by activating tumor-specific immune response, which has the advantages of relatively low toxicity and high efficiency, and has attracted much attention in recent years. However, there are still difficulties in how to effectively deliver tumor vaccines in vivo and make them work efficiently. It is a relatively mature method to load tumor specific antigens with suitable carriers to produce tumor vaccines. Here, a generally minimalist construction method of tumor nanovaccine was developed. A high-efficiency tumor nanovaccine (NV) was prepared in one step by a biomineralization-like method, which contained ovalbumin (OVA, model antigen), unmethylated cytosine-phosphate-guanine (CpG, adjuvant) and Mn-NP (carrier and adjuvant). NV not only showed good tumor preventive effect, but also could successfully inhibited tumor development and metastasis when combined with anti-PD-L1, and induced long-term immune memory effect. However, the method of screening tumor specific antigen to construct nanovaccine is cumbersome and tumors are heterogeneous. Therefore, surgically resected tumor tissue is the best source of antigens for preparing tumor vaccines. Next, based on the strong loading ability of the carrier, we designed a personalized tumor nanovaccine (PNV) using the supernatant of tumor abrasive fluid (STAF) as antigen based on the generally minimalist tumor nanovaccine construction strategy. PNV combined with anti-PD-L1 could successfully inhibit post-surgical tumor recurrence and induce strong and durable immune memory effects. This study presents a novel, general, and minimalist strategy to construct high-efficiency personalized nanovaccine, which has a wide range of potential applications in the field of tumor treatment. [ABSTRACT FROM AUTHOR]

Microbial nitrogen (N) limitation is a common problem in terrestrial ecosystems. Pig manure, a type of solid waste, is increasingly applied to improve soil N availability in agriculture through inputs of organic matter and inorganic N. Pig manure application also introduces a lot of exogenous microorganisms, which have distinctly different N requirements and metabolic properties, into the resident soil microbial community. However, the impacts of these manure-borne microorganisms on soil N cycling have not been well determined. Here, we investigated effects of manure-borne microorganisms on the N limitation of soil microorganisms using an ecoenzymatic stoichiometry analysis. We monitored microbial communities over a 90-day period in a laboratory-controlled experiment with four treatments: (1) non-sterilized soil mixed with non-sterilized manure (S-M), (2) non-sterilized soil mixed with sterilized manure (S-sM), (3) sterilized soil mixed with non-sterilized manure (sS-M), and (4) non-sterilized soil without manure addition (S, the control). The microbial N limitations were significantly mitigated in both S-M and sS-M. By contrast, the S-sM and S showed high levels of microbial N limitation, likely stemming from differences in the microbial functional composition. We found chitin-degrading bacteria were the dominant copiotrophic manure-borne bacteria associated with N mineralization, and they may improve soil N availability. We further identified several copiotrophic manure-borne bacteria in S-M and sS-M, and their abundances had significantly negative correlation with the level of N limitation and significantly positive correlation with the stoichiometric homeostasis. As these copiotrophic taxa can maintain homeostasis through regulating enzymatic activities, our results indicate that copiotrophic taxa in pig manure contribute to the mitigation of soil microbial N limitation. Our study also highlights the invasiveness capacity of manure-borne microorganisms in soil and evaluates the biotic effects of manure application on soil N cycling. [Display omitted] • Manure application mitigates microbial nitrogen limitation in soil. • Manure application improves biomass C:N homeostasis of soil microbial communities. • Diverse copiotrophic taxa were introduced into soil through manure application. • Copiotrophic taxa could contribute to the mitigation of nitrogen limitation. [ABSTRACT FROM AUTHOR]

Organic amendments not only promote soil quality and plant performance directly but also facilitate the establishment of introduced microbial agents. A field experiment with a fully factorial design was conducted using three levels of vermicompost (without vermicompost, low dose of 15 Mg ha −1 and high dose of 30 Mg ha −1 ), with and without plant growth-promoting rhizobacteria (PGPR) to investigate their effects in a tomato – by spinach rotation system. Our results demonstrated that applying PGPR alone had no effect on soil properties and crop performance. Vermicompost enhanced the beneficial effects of PGPR on both soil and crop, with the extent of promotion depending on the dose of vermicompost and crop types. In the presence of vermicompost, PGPR significantly ( P < 0.05) reduced soil carbon and nitrogen but increased soil microbial biomass carbon and nitrogen. PGPR also significantly increased the yield of tomato and spinach under the low dose of vermicompost, but only significantly increased tomato yield under the high dose of vermicompost. There were strongly synergistic effects between vermicompost and PGPR on crop quality, with crop nitrate concentration being significantly decreased, while the vitamin C in tomato and soluble protein in spinach was significantly increased. Our results revealed the high potential of integrating vermicompost and microbial agents to substitute for regular chemical fertilization practices. [ABSTRACT FROM AUTHOR]

Manure fertilization contributes to crop production and sustainable agriculture by introducing large amounts of nutrients and exogenous microbes into soil. However, the contribution of exogenous microbes in shaping soil bacterial community and network structure after fertilization are still controversial. In this study, bacterial communities and network structure that received unsterilized (R + C) or sterilized (R + SC) manure fertilizers, as well as no fertilizer control (R), were characterized using high throughput sequencing. Results showed that the relative abundance of fertilizer-derived OTUs decreased from 10.4% to 4.6% after 90 days incubation, while the Bray-Curtis distance between the control and fertilization group (R + C and R + SC) gradually increased with the culture time. It can be supposed that manure fertilization altered soil bacterial communities by interfering the growth of indigenous bacteria rather than the colonization of fertilizer-derived bacteria. Network analysis showed that a subset of the fertilizer-derived OTUs identified as Xanthomonadales order and Promicromonospora , Constrictibacter genera acted as connectors between modules. They enhanced the interactions not only between soil-derived OTUs and fertilizer-derived OTUs, but also within indigenous bacteria, supported that the introduction of fertilizer-derived exogenous bacteria contributes large to soil bacterial network association. Moreover, fertilizer-derived OTUs presented to be positively correlated with soil pH, while majority soil-derived OTUs presented to be negatively correlated with various physicochemical variables (pH, DOC, NO 3 −, and LAP). Our study highlighted the critical role of fertilizer-derived bacteria in regulating indigenous soil microbial community and network formation after fertilization. [Display omitted] • Manure fertilization altered soil bacterial communities mainly due to the organic components input. • Fertilizer-derived bacteria colonization contributed little to soil bacterial community shift under manure fertilization. • Some fertilizer-derived OTUs enhanced the interactions within indigenous bacteria as connectors. [ABSTRACT FROM AUTHOR]

Cardiovascular comorbidities are pervasive in chronic obstructive pulmonary disease (COPD) and often result in serious adverse cardiovascular events. Tongxinluo (TXL) has been clinically verified to treat atherosclerosis (AS), improve lung function and alleviate dyspnoea. The present study aimed to explore the effect of lung microvascular barrier dysfunction on AS in COPD and the potential pulmonary protective mechanisms of TXL in COPD complicated with AS. COPD complicated with AS was induced in mice by cigarette smoke (CS) exposure and high-fat diet (HFD) feeding. The mice were treated with atorvastatin (ATO), TXL or combination therapy (ATO+TXL) for 20 weeks. Pulmonary function, lung pathology, serum lipid levels, atherosclerotic plaque area and indicators of barrier function, oxidative stress and ferroptosis in lung tissue were evaluated. In vitro, human pulmonary microvascular endothelial cells (HPMECs) were pretreated with TXL for 4 h and then incubated with cigarette smoke extract (CSE) and homocysteine (Hcy) for 36 h to induce barrier dysfunction. Then the indicators of barrier function, oxidative stress and ferroptosis were measured. The results demonstrate that CS aggravated dyslipidaemia, atherosclerotic plaque formation, pulmonary function decline, pathological injury, barrier dysfunction, oxidative stress and ferroptosis in the HFD-fed mice. However, these abnormalities were partially reversed by ATO and TXL. Similar results were observed in vitro. In conclusion, pulmonary microvascular barrier dysfunction plays an important role by which COPD affects the progression of AS, and ferroptosis may be involved. Moreover, TXL delays the progression of AS and reduces cardiovascular events by protecting the pulmonary microvascular barrier and inhibiting ferroptosis. [Display omitted] • Pulmonary microvascular barrier dysfunction is a mechanism that COPD affects AS. • TXL can be combined with ATO to treat COPD complicated with AS. • TXL could reduce oxidative stress and inhibit ferroptosis in lung tissue or HPMECs. [ABSTRACT FROM AUTHOR]

Abstract: Microcosm experiments were carried out to study the effects of bacterial-feeding nematodes and prometryne on soil bacterial communities in contaminated soil. Prometryne (5 or 10mgkg−1 dry soil, that is, P5 or P10) and bacterial-feeding nematodes (5 or 10 individuals g−1 dry soil, that is, N5 or N10), singly and in combination (P5N5, P5N10, P10N5, P10N10), were added to a nematode-free soil. An uncontaminated nematode-free soil was studied for comparison (Control). Bacterial-feeding nematode grazing boosted soil enzyme activities in contaminated soils, thus speeding up prometryne degradation. In the initial stage of the experiment, prometryne enhanced the soil enzyme activities too, but served the opposite purpose later. Denaturing gradient gel electrophoresis (DGGE) analysis indicated that prometryne contamination and nematode grazing over the incubation period exerted an obvious impact on Species richness (S), Shannon–Wiener index (H′) and Evenness (E H ) of soil bacteria, which increased initially, then decreased and increased again later. The cluster analysis of DGGE profiles showed that the similarity of soil bacterial communities in all treatments with indigenous microbes, P5, P5N5, P5N10, P10, P10N5, and P10N10 and the Control was 75%, 44%, 78% and 49% at Day 0, Day 8, Day 18 and Day 30, respectively. Compared to the Control, DGGE profiles displayed a varying characteristic bands pattern in all treatments over the incubation period with certain bands present in the treatments while not in the Control and vice versa, suggesting that bacterial-feeding nematode grazing and prometryne contamination affected soil bacterial communities evidently. Consequently, when added to contaminated soil, bacterial-feeding nematodes can contribute to restoration of contaminated sites by degrading toxic compounds like prometryne through enhanced microbial activity. [Copyright &y& Elsevier]

Abstract: Understanding the effects of aging time on the fraction distribution and bioavailability of PAH, such as phenanthrene (PHE) and pyrene (PYR), has considerable benefits for risk assessment, food security and remediation strategies for contaminated soil. The results of the present study show that the proportion of the desorbed PHE decreased from ca. 82% at day 0 to ca. 65% at day 150. In addition, non-desorbed PHE increased from ca. 18% at day 0 to ca. 31% at day 150, whereas the changes of desorbed and non-desorbed PYR showed no significant trend during this aging period. The proportion of desorbed PYR was lower than that of PHE, whereas the opposite occurred with the non-desorbed fraction. After 150d of aging, the proportion of bound residues (PHE and PYR) increased significantly with the cultivating time from ca. 0.2% to ca. 4.7% and ca. 0.1% to ca. 1.2% for PHE and PYR, respectively. In addition, the bioavailability of PAH (PHE and PYR) to earthworms was also assessed over 0–150d. The results showed that the uptake rate and bioconcentration factor (BCF) of pollutants by earthworms displayed the following biphasic character: a rapid decrease over the first 15d followed by a slow decrease over the next 135d. Moreover, the earthworm uptake rate of PHE was greater than that of PYR throughout the incubation period, indicating that PHE has a higher bioavailability than PYR. In addition, the positive correlation between the uptake rate of earthworms and PAH extractability suggested that a three-step extraction is a reliable approach to predict PHE bioavailability in soil. However, a limit was observed for PYR. [Copyright &y& Elsevier]

Abstract: The effects of bacterial-feeding nematodes on nitrification and the ammonia-oxidizing bacteria (AOB) community composition were studied in soil microcosms. Sterilized soils were inoculated with mixed soil bacteria (obtained by filtering) or with bacteria and bacterial-feeding nematodes, after which the dynamic inorganic nitrogen concentration was measured weekly. After 28 days of incubation, denaturing gradient gel electrophoresis (DGGE) based on PCR amplification of the amoA gene was used to analyze the AOB community composition. In addition, a clone library from the amoA gene fragments was established using clones randomly selected and sequenced from the two treatments. The results showed that the presence of bacterial-feeding nematodes led to significantly greater NH4 + and NO3 − contents over the entire incubation period, indicating that bacterial-feeding nematodes promoted both N mineralization and nitrification. The results of DGGE showed that the AOB community composition was significantly changed in the presence of bacterial-feeding nematodes. Furthermore, the sequencing results suggested that Nitrosospira sp. was the dominant species in the treatment without nematodes, while Nitrosomonas sp. and Nitrosospira sp. were the dominant species in the treatment with nematodes. Such changes in the AOB community may be one of explanation of the important role that nematodes play in promoting nitrification. [Copyright &y& Elsevier]

Abstract: The effect of earthworms on soil hydrolases (protease, urease, invertase, and alkaline phosphatase) and dehydrogenase activities was investigated in maize residue amended rice–wheat rotation agro-ecosystem. Experimental plots in the rotation had five treatments, i.e. incorporation or mulching of maize residues with or without added earthworms and an untreated control. The application of maize residues to soil without earthworms significantly enhanced the five soil enzyme activities compared with the control treatment during rice and wheat cultivation. The presence of earthworms further significantly enhanced protease activity in the soils with both incorporated and mulched maize residues during two cultivation seasons, but only significantly increased alkaline phosphatase activity in the soil with incorporated maize residue during the rice cultivation season. Invertase activity was significantly enhanced by the presence of earthworms in the soil with maize residue incorporation during two cultivation seasons. There were no changes in dehydrogenase activity when earthworms were present. Additionally, the five enzyme activities in earthworm casts were significant higher than those in the surrounding soil, especially dehydrogenase and invertase activities. Whatever the treatment, the values obtained for the enzyme activities in both soil and casts, except for dehydrogenase activity in earthworm casts, were significantly higher under wheat than those in rice-cultivated soil. These results indicate that the presence of earthworms strongly affected soil enzyme activities, depending on the method of organic residue application, and the enhanced enzyme activities of earthworm casts probably contributed to the surrounding soil enzyme activities. [Copyright &y& Elsevier]

Abstract: Understanding the effects of alternative farming on soil quality parameters, such as microbial communities, size, activity and soil nutrient content, is of central importance to concepts of sustainability. Combining organic amendments with chemical fertilizer is a promising approach to develop more sustainable fertilization strategies. We investigated the impacts of quantity, type and application time of organic amendments on temporal dynamics of paddy soil microbial biomass, activity, carbon fractions and nutrient status under a long-term field experiment in a rice–rice cropping system. We established treatments with seven fertilization practices characterized by different quantities and application times of green manure (GM), farmyard manure (FYM) and rice straw (RS) in combination with low amount of chemical fertilizers. We further established one treatment with only recommended amount of chemical fertilizer and an unfertilized control. At all sampling times, organic amendments with low amount of chemical fertilizer enhanced microbial biomass, activity and nutrient availability more than recommended amount of chemical fertilization only and an unfertilized control, with higher quantities of FYM resulting in stronger effects than all other organic amendments. The strongest increase of microbial biomass, activity, carbon and nutrient availability was generally found in the treatment with the most diverse resources and highest amount of organic amendments. Principle component analysis indicated that most soil variables measured were correlated to total soil organic C. Regression analysis indicated that the integrated paddy soil properties were closely related to yearly C input and rice yield. Strong temporal dynamics were demonstrated for all soil variables, indicating that we need multiple time sampling strategies to explore the overall influences of fertilization practices on paddy soil. Our results indicate that the development of effective fertilization practices, especially by manipulating the quantity and type of organic amendments, may improve long-term sustainability of paddy soil ecosystems. [Copyright &y& Elsevier]

The application of organic fertilizers affects soil aggregates, nutrient situations and bacterial communities. However, the direct and indirect effect of different resource-derived organic fertilizers on soil bacterial communities and their links to soil aggregate is poorly understood. Here, we carried out a field experiment for three years to investigate the linkages between soil aggregates and bacterial diversity in a dryland red soil. Six treatments were compared: (no fertilizer (CK), chemical fertilizer (CF), 60% chemical fertilizer + straw at 4500 kg ha−1 (RFS), 60% CF + biochar at 1500 kg ha−1 (RFB), 60% CF + pig manure at 15000 kg ha−1 (RFP), and 60% CF + vermicompost at 15000 kg ha−1 (RFV)). The application of pig manure or vermicompost (animal-derived organic fertilizer) enhanced the soil pH, the content of large macroaggregate (>2 mm), organic matter, available phosphorous and available nitrogen, while decreased the content of small macroaggregate (0.25–2 mm) and microaggregate (<0.25 mm) compared with other treatment. Relative abundances of the dominant bacterial phyla varied across chemical and organic fertilizer treatments, primarily by increasing Bacteroidetes, Gemmatimonadetes, and decreasing Chloroflexi, Acidobacteria and Planctomycetes. Organic fertilizers particularly animal-derived organic fertilizer enhanced the Richness, Shannon and Pielou indices of soil bacteria compared with chemical fertilizer treatment. The regulation of animal-derived organic fertilizers on bacterial community structure (accounting for 53.04% of the variance) was greater than that of plant-derived organic fertilizers (straw and biochar, accounting for 7.69% of the variance). The bacterial alpha diversity showed positive correlation with large macroaggregate, but a negative correlation with small macroaggregate. Further, structural equation models indicated that animal-derived organic fertilizers impacted bacterial diversity positively by regulating resource availability through soil aggregates. However, for the plant-derived organic fertilizers, bacterial diversity was negatively affected by soil aggregates alone, but this was not regulated by fertilization. In addition, animal-derived organic fertilizer also positively affected soil bacteria diversity indirectly via changing soil pH and resource availability. Overall, the different impacts of animal- and plant-derived organic fertilizers on soil bacterial community highlighting the pivotal role of soil habitat architecture and resource chemistry changed by organic fertilizers in the regulation of soil bacteria, which may influence soil quality and agricultural sustainable development. • Animal-derived organic fertilizer (AOF) decreased 0.25–2 and <0.25 mm soil aggregates. • AOF increased >2 mm soil aggregates, pH, organic matter, available P and N. • AOF affect soil bacterial community structure than plant-derived (POF). • AOF affect bacterial community mainly via changing aggregates, pH and resource availability. • Aggregates affect bacterial diversity alone under POF, but not regulated by fertilization. [ABSTRACT FROM AUTHOR]