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Soil respiration (R s ) is a major component of the global carbon (C) cycle and is influenced by the availability of nutrients such as phosphorus (P). However, the response of R s to P addition in P-limited subtropical forest ecosystems and the underlying mechanisms remain poorly understood. To address this, we conducted a P addition experiment (50 kg P ha -1  yr -1 ) in a subtropical Chinese fir (Cunninghamia lanceolata) plantation forest. We separated R s into heterotrophic respiration (R h ), root respiration (R r ), and mycorrhizal hyphal respiration (R m ), and quantified soil properties, microbial biomass (phospholipid fatty acid, PLFA), fungal community composition (ITS), and the activity of extracellular enzymes. Phosphorus addition significantly increased R s and R h , but decreased R r and did not influence R m . Further, P addition increased fungal, bacterial, and total PLFAs, and phenol oxidase activity. Conversely, P application decreased root biomass and did not alter the relative abundance of symbiotrophic fungi. Phosphorus enrichment therefore enhances soil C emissions by promoting organic matter decomposition by heterotrophic activity, rather than via increases in root or mycorrhizal respiration. This advances our mechanistic understanding of the relationship between fertility and soil respiration in subtropical forests, with implications for predicting soil C emissions under global change., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Tree species establish mycorrhizal associations with both ectomycorrhizal (EM) and arbuscular mycorrhizal fungi (AM), which play crucial roles in facilitating plant phosphorus (P) acquisition. However, little attention has been given to the effects of EM and AM species on soil P dynamics and the underlying mechanisms in subtropical forests, where P availability is typically low. To address this knowledge gap, we selected two EM species ( Pinus massoniana - PM and Castanopsis carlesii - CC) and two AM species ( Cunninghamia lanceolata - Chinese fir, CF and Michelia macclurei - MM) in a common garden established in 2012 in subtropical China. We investigated soil properties (e.g., pH, soil organic carbon, total nitrogen, and dissolved organic nitrogen), soil P fractions, phospholipid fatty acids (PLFAs), enzyme activities, foliar manganese (Mn) concentration, and foliar nutrients and stoichiometry. Our findings revealed that soils hosting EM species had higher levels of resin P, NaHCO 3 -Pi, extractable Po, total P, and a greater percentage of extractable Po to total P compared to soils with AM species. These results indicate that EM species enhance soil P availability and organic P accumulation in contrast to AM species. Moreover, EM species exhibited higher P return to soil (indicated by higher foliar P concentrations) when compared to AM species, which partly explains higher P accumulation in soils with EM species. Additionally, resin P showed a positive correlation with acid phosphatase (ACP) activity, whereas no correlation was found with foliar Mn concentration, which serves as a proxy for the mobilization of sorbed soil P. Such findings indicate that organic P mineralization has a more substantial impact than inorganic P desorption in influencing P availability in soils hosting both EM and AM species. In summary, our study contributes to a more comprehensive understanding of the effects of mycorrhizal associations on soil P accumulation in subtropical forests and provide valuable insights into plant-soil interactions and their role in P cycling in regions with limited P availability., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Lian, Xu, Yang, Yue and Peñuelas.)

Adding industrial and agricultural wastes to farmland can increase soil available phosphorus (P) pool and boost crop production, but the process affecting soil P transformation and bioavailability is still poorly understood. We studied the effects of straw (ST), biochar (BC) and Si-modified biochar (Si-BC) amendments on the available-P content and its fraction transformation in rice-paddy soils. Our results showed that these three soil amendments significantly increased the concentrations of both microbial biomass carbon (MBC) and microbial biomass-P (MBP) during the first rice season; by contrast, the effects of ST and BC application were relatively poor on acid-phosphatase (ACP) activity, which was increased by 24 % under ST and 14 % under BC. Soil total P concentrations did not differ significantly, although the concentration and percentage of each P-fraction were altered significantly among treatments. Although all three applications increase soil available-P concentration by promoting the transformation of organic-P (Po) components to inorganic-P (Pi), there are differences in the transformation efficiency of the soil P fraction between these amendments. Redundancy analysis results also showed significant clustering of soil P-fraction transformations after ST and BC treatments. Structural equation model analysis further indicated that all amendments regulated microbial processes by changing soil pH and dissolved organic carbon (DOC), thereby promoting soil P transformation and improving P efficiency. Sodium bicarbonate-extractable Po (NaHCO 3 -Po) contributed most to soil available-P under the different amendments. Compared to ST and Si-BC, BC application improved more soil microbial status and the transformation of soil unavailable-P into available-P, therefore the application of BC in rice fields is the most beneficial method to promote phosphorus use and production sustainability in rice. These findings helped to understand the effects of using industrial and agricultural waste (e.g. straw, biochar and Si-modified biochar) on soil P-fractions and so provided a reference for sustainable resource use and green production in rice-paddy ecosystems., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023. Published by Elsevier B.V.)

In recent years, the simplified lattice Boltzmann method without evolution of distribution functions was developed, which adopts predictor-corrector steps to solve the constructed macroscopic equations. To directly solve the constructed macroscopic equations in a single step, we propose the present one-step simplified lattice Boltzmann method and apply it to simulate thermal flows under the Boussinesq approximation. The present method is derived by reconstructing the evolution equation of the lattice Boltzmann method and constructing nonequilibrium distribution functions. This method inherits the advantages of the simplified lattice Boltzmann method, such as low virtual memory cost, convenient boundary treatment, and good numerical stability at relaxation time close to 0.5. In addition, compared to the traditional artificial compressible method (ACM), the present method is more efficient in computation when a small time step is applied in the ACM to ensure numerical stability. Several numerical examples, including natural convection in a square cavity, the porous plate problem, and natural convection in a concentric annulus, are conducted to test the accuracy of the present method. The results show that this method can accurately simulate thermal flow problems and has good numerical stability.

Biochar-derived dissolved organic carbon (BDOC), as a highly activated carbonaceous fraction of biochar, significantly affects the environmental effect of biochar. This study systematically investigated the differences in the properties of BDOC produced at 300-750 °C in three atmosphere types (including N 2 and CO 2 flows and air limitation) as well as their quantitative relationship with biochar properties. The results showed that BDOC in biochar pyrolyzed in air limitation (0.19-2.88 mg/g) was more than that pyrolyzed in N 2 (0.06-1.63 mg/g) and CO 2 flows (0.07-1.74 mg/g) at 450-750 °C. The aliphaticity, humification, molecular weight, and polarity of BDOC strongly depended on the atmosphere types as well as the pyrolysis temperatures. BDOC produced in air limitation contained more humic-like substances (0.65-0.89) and less fulvic-like substances (0.11-0.35) than that produced in N 2 and CO 2 flows. The multiple linear regression of the exponential form of biochar properties (H and O contents, H/C and (O+N)/C) could be used to quantitatively predict the bulk content and organic component contents of BDOC. Additionally, self-organizing maps could effectively visualize the categories of fluorescence intensity and components of BDOC from different pyrolysis atmospheres and temperatures. This study highlights that pyrolysis atmosphere types are a crucial factor controlling the BDOC properties, and some characteristics of BDOC can be quantitatively evaluated based on the properties of biochar.

Acute lung injury (ALI) represents a frequent sepsis-induced inflammatory disorder. Mesenchymal stromal cells (MSCs) elicit anti-inflammatory effects in sepsis. This study investigated the mechanism of exosomes from adipose-derived MSCs (ADMSCs) in sepsis-induced ALI. The IL-27r -/- (WSX-1 knockout) or wild-type mouse model of sepsis was established by cecal ligation and puncture (CLP). The model mice and lipopolysaccharide (LPS)-induced macrophages were treated with ADMSC-exosomes. The content of Dil-labeled exosomes in pulmonary macrophages, macrophages CD68 + F4/80 + in whole lung tissues, and IL-27 content in macrophages were detected. The mRNA expression and protein level of IL27 subunits P28 and EBI3 in lung tissue and the levels of IL-6, TNF-α, and IL-1β were measured. The pulmonary edema, tissue injury, and pulmonary vascular leakage were measured. In vitro, macrophages internalized ADMSC-exosomes, and ADMSC-exosomes inhibited IL-27 secretion in LPS-induced macrophages. In vivo, IL-27 knockout attenuated CLP-induced ALI. ADMSC-exosomes suppressed macrophage aggregation in lung tissues and inhibited IL-27 secretion. ADMSC-exosomes decreased the contents of IL-6, TNF-α, and IL-1β, reduced pulmonary edema and pulmonary vascular leakage, and improved the survival rate of mice. Injection of recombinant IL-27 reversed the protective effect of ADMSC-exosomes on sepsis mice. Collectively, ADMSC-exosomes inhibited IL-27 secretion in macrophages and alleviated sepsis-induced ALI in mice., (© 2022. The Author(s).)

Climate warming is becoming an increasingly serious threat. Understanding plant stoichiometry changes under climate warming is crucial for predicting the effects of future warming on terrestrial ecosystem productivity. Nevertheless, how plant stoichiometry responds to warming when interannual rainfall variation is considered, remains poorly understood. We performed a field soil warming experiment (+5°C) using buried heating cables in subtropical areas of China from 2015 to 2018. Stoichiometric patterns of foliar C:N:P:K:Ca:Mg, non-structural carbohydrate, and stable isotope of Cunninghamia lanceolata seedlings were studied. Our results showed that soil warming decreased foliar P and K concentrations, C:Ca, P:Ca, and P:Mg ratios. However, soil warming increased foliar Ca concentration, δ 15 N value, C:P and N:P ratios. The response ratios of foliar N, C:N, and δ 15 N to soil warming were correlated with rainfall. Our findings indicate that there was non-homeostasis of N and C:N under warming conditions. Three possible reasons for this result are considered and include interannual variations in rainfall, increased loss of N, and N limitation in leaves. Piecewise structural equation models showed that stoichiometric non-homeostasis indirectly affected the growth of C. lanceolata seedlings in response to soil warming. Consequently, the growth of C. lanceolata seedlings remained unchanged under the warming treatment. Taken together, our results advance the understanding of how altered foliar stoichiometry relates to changes in plant growth in response to climate warming. Our results emphasize the importance of rainfall variations for modulating the responses of plant chemical properties to warming. This study provides a useful method for predicting the effects of climate warming on economically important timber species., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Zhang, Luo, Yang, Xie, Yang, Zhou, Li, Xiong, Chen and Yang.)

Optimal methods for incorporating soil microbial mechanisms of carbon (C) cycling into Earth system models (ESMs) are still under debate. Specifically, whether soil microbial physiology parameters and residual materials are important to soil organic C (SOC) content is still unclear. Here, we explored the effects of biotic and abiotic factors on SOC content based on a survey of soils from 16 locations along a ~4000 km forest transect in eastern China, spanning a wide range of climate, soil conditions, and microbial communities. We found that SOC was highly correlated with soil microbial biomass C (MBC) and amino sugar (AS) concentration, an index of microbial necromass. Microbial C use efficiency (CUE) was significantly related to the variations in SOC along this national-scale transect. Furthermore, the effect of climatic and edaphic factors on SOC was mainly via their regulation on microbial physiological properties (CUE and MBC). We also found that regression models on explanation of SOC variations with microbial physiological parameters and AS performed better than the models without them. Our results provide the empirical linkages among climate, microbial characteristics, and SOC content at large scale and confirm the necessity of incorporating microbial biomass and necromass pools in ESMs under global change scenarios., (© 2021 John Wiley & Sons Ltd.)

Huangqi, the dried root of Radix Astragali, is an essential herb in Traditional Chinese Medicine and has been used to promote hematopoiesis for centuries. Astragalus polysaccharide (ASPS), the bioactive compound of Huangqi, serves a crucial role in hematopoiesis. The aim of the present study was to investigate the hematopoietic effects, in particular the thrombopoietic effects, and the molecular mechanisms of ASPS using an irradiation‑induced myelosuppressive mouse model. Colony‑forming unit assays, flow cytometric analysis of apoptosis, ELISAs, Giemsa staining and western blotting were performed to determine the hematopoietic and anti‑apoptotic effects of ASPS. The results demonstrated that ASPS enhanced the recovery of red blood cells at day 21 following treatment, as well as platelets and white blood cells at day 14. In addition, ASPS promoted colony formation in all lineages (megakaryocytes, granulocyte monocytes, erythroid cells and fibroblasts). The morphological study of the bone marrow demonstrated that tri‑lineage hematopoiesis was preserved in the ASPS‑ and thrombopoietin (TPO)‑treated groups compared with the control group. The overall cellularity (mean total cell count/area) of the ASPS‑treated group was similar to that of the TPO‑treated group. Additionally, in vitro experiments indicated that treatment with 100 µg/ml ASPS exhibited the maximum effect on colony formation. ASPS attenuated cell apoptosis in megakaryocytic cells via inhibiting the mitochondrial caspase‑3 signaling pathway. In conclusion, ASPS promoted hematopoiesis in irradiated myelosuppressive mice possibly via enhancing hematopoietic stem/progenitor cell proliferation and inhibiting megakaryocytes apoptosis.

There has been an increasing interest in studying microbial necromasses and their contribution to soil organic carbon (SOC) accumulation. However, it remains unclear how the interaction among climate, plants, and soil influence the microbial anabolism and how microbial necromass contribute to SOC formation. Here, we assessed the relative contribution of microbial residues to SOC pool across a subtropical elevation gradient (ranged from 630 to 2130 m a.s.l.) representing a subtropical ecosystem on Wuyi Mountain in China, by using amino sugars as tracers. Analysis of topsoil (0-10 cm) amino sugars and the composition of microbial community across this gradient revealed that the soil total amino sugars accounting for 12.2-25.7% of the SOC pool, decreased with increasing elevation. Moreover, the linear reduction in the bacterial-derived carbon (C) and an increase in the ratio of fungal- to bacterial-derived C with increasing elevation suggested the reduction in the contribution of bacterial-derived C to SOC pool across this elevation gradient. The divergent changes in the contribution of the microbial residues to SOC infer a potential change in SOC composition and stability. The microbial-derived SOC formation and its climatic responses are influenced by the interaction of vegetation types and soil properties, with soil amorphous Fe being the determiner of soil amino sugar accrual. Our work highlights the importance of understanding ecosystem type and mineral composition in regulating microbial-mediated SOC formation and accumulation in responses to climate change in subtropical ecosystems., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier B.V. All rights reserved.)

A crucial mechanism for the application of biochar in soil improvement is the direct release of nutrients from biochar. Low molecular weight organic acids (LMWOAs) ubiquitously exist in soil. However, the mechanism of LMWOAs-mediated release of nutrients from biochars remains little known. Ten biochars with different mineral element stoichiometric ratio were produced, and four LMWOAs [acetic (HAc), glycolic (GA), tartaric (TA), and citric acids (CA)] were employed, to enunciate the influence mechanism of LMWOAs on the release of phosphorus and potassium from biochar. The results showed that HAc suppressed the release of P from biochars, while TA and CA facilitated the release of P from biochars with high ratios of polyvalent metals to P. A new mechanism was proposed that the deprotonated HAc combined with the dissolved HPO 4 2- or H 2 PO 4 - to form a complex through hydrogen bond and cation bridging. The hydrophobic methyl group of HAc was exposed outside of the complex, which decreased the water-solubility of phosphate. Meanwhile, a high ratio of polyvalent metals to P benefited more P to combine with polyvalent metals, which decreased the water-solubility of P, but the deprotonated TA and CA are polyvalent anions that could substitute this part of P by anion exchange. Also, LMWOAs promoted the release of K from biochars with low K/(P + S) ratios, possibly due to unionized carboxyl of LMWOAs served as a hydrogen bond donor to displace K out of biochars. This study gives a deep understanding of the fate of biochar originated nutrients response to LMWOAs., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier B.V. All rights reserved.)

The different effects of nitrogen-flow (NF) and air-limitation (AL) pyrolysis on the characteristics and nutrient retention of biochars (BCs) are unclear. Hence, in this study, BCs derived from bamboo, corn straw, and wheat straw were produced in AL and NF atmospheres at various temperatures (300-750 °C), and their different characteristics and nutrient retention rates were compared systematically. Nitrogen-flow pyrolysis facilitates C retention and graphitic C formation, and AL pyrolysis improves the polarity and supports the formation of oxygen-containing groups. With increasing pyrolysis temperature, C retention and graphitic C formation in BCs derived from AL pyrolysis decreases more significantly compared with BCs from NF pyrolysis. At 750 °C, the polarity and oxygen-containing groups of BCs derived from AL pyrolysis increase, whereas those from BCs derived from NF pyrolysis decrease. The observations are attributable to the AL and high-temperature-enhanced oxidization and gasification of C. An AL atmosphere with a higher pyrolysis temperature supports porosity and results in a larger specific surface area. Although pyrolysis temperature and atmosphere have negligible effects on nutrient retention, a low pyrolysis temperature facilitates the formation of water-soluble Ca, Mg, and P, and AL pyrolysis facilitates the formation of water-soluble P because the high pyrolysis temperature improves the pH and mineral stability of BCs, and air limitation facilitates the oxidation of organic P into PO 4 3- . This study provides a reference for selecting AL or NF pyrolysis based on various pyrolysis temperatures to produce BCs and applying these in C sequestration, contaminant sorption, and soil quantity improvement., (© 2020 The Authors. Journal of Environmental Quality © 2020 American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America.)

Clinical studies have shown that melatonin lowers the frequency of thrombocytopenia in patients with cancer undergoing radiotherapy or chemotherapy. Here, we investigated the mechanisms by which melatonin promotes platelet formation and survival. Our results show that melatonin exerted protective effects on serum-free induced apoptosis of CHRF megakaryocytes (MKs). Melatonin promoted the formation of MK colony forming units (CFUs) in a dose-dependent manner. Using doxorubicin-treated CHRF cells, we found that melatonin rescued G2/M cell cycle arrest and cell apoptosis induced by doxorubicin. The expression of p-AKT was increased by melatonin treatment, an effect that was abolished by melatonin receptor blocker. In addition, we demonstrated that melatonin enhanced the recovery of platelets in an irradiated mouse model. Megakaryopoiesis was largely preserved in melatonin-treated mice. We obtained the same results in vivo from bone marrow histology and CFU-MK formation assays. Melatonin may exert these protective effects by directly stimulating megakaryopoiesis and inhibiting megakaryocyte apoptosis through activation of its receptors and AKT signaling.

On 3rd to May 24, 2018, volatile organic compound (VOC) samples were collected four times a day by using stainless steel canisters at an urban site in Zhengzhou, China. The concentrations, compositions, sources, ozone (O 3 ) formation potential (OFP), and health risk assessment of VOCs were discussed based on the measurements of 103 VOC species. Results show that the average mixing ratio of VOCs was 29.11 ± 15.33 ppbv, and the dominant components comprised oxygenated VOCs (OVOCs) and alkanes, followed by halocarbons, alkenes, aromatics, and a sulfide. Various groups of VOCs had typical diurnal variation characteristics. Alkenes, alkanes, and aromatics contributed most to the OFP. Five sources identified by the positive matrix factorization model revealed solvent utilization as the largest contributor, followed by industrial production, long-lived and secondary species, vehicular emission, and biogenic emission. Solvent utilization and vehicular emission were important sources to OFP. During O 3 episode days, the mixing ratios of alkanes, alkenes, halocarbons, OVOCs, aromatics, and TVOCs decreased to varying degrees; the source contribution of solvent utilization decreased significantly while industrial production showed the opposite trend. VOC species and sources posed no non-carcinogenic risk while five species and all sources except for biogenic emission had carcinogenic risks to exposed population. Industrial emission was the largest contributor to both non-carcinogenic and carcinogenic risks. These results will help to provide some references for O 3 pollution research and prevention and control of pollution sources., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

Thrombopoietin (TPO) is a growth factor for the megakaryocytic/platelet lineage. In this study, we investigated the expression of TPO and its receptor, c-Mpl, in the human central nervous system (CNS) and their roles after a neural insult. Our results demonstrate that both TPO and c-Mpl are expressed in the neurons of the human CNS. TPO was also detected in human cerebrospinal fluid. TPO was found to be neuroprotective in hypoxic-ischemic neonatal rat brain models. In these rat models, treatment with TPO reduced brain damage and improved sensorimotor functions. In addition, TPO promoted C17.2 cell proliferation through activation of the PI3K/Akt signaling pathway. Via the Bcl-2/BAX signaling pathway, TPO exerted an antiapoptotic effect by suppressing mitochondrial membrane potentials. Taken together, our results indicate that TPO is neuroprotective in the CNS.

Biochar is composed of carbonaceous and inorganic (ash) fractions. The structural properties of carbonaceous fractions and the composition of ash in biochar are both variable with pyrolysis temperature. However, it is unknown whether ash may play different roles in sorption of organic compounds to the carbonaceous fraction of biochars produced at different temperatures. Hence, in this study, the pristine biochars produced at 300-900°C and their corresponding deashed biochars were investigated, and the combined roles of carbonaceous fraction and ash in sorption of triclosan were compared. The results showed that the biochars produced at 300-400°C had high content of uncarbonized organic structure with dominating partition effect. The combination of uncarbonized organic structure and ash had comparable or even higher sorption coefficient (K D ) for triclosan at low concentration compared with a single uncarbonized organic structure. However, for the biochars produced at 600-900°C, which were mainly composed of carbonized or graphitized carbon structure, ash had significant effect on triclosan sorption by reducing surface adsorption and pore filling effect. The combination of carbonaceous fraction and ash decreased K D values for triclosan at any tested concentrations. In addition, the results of pH effect on sorption indicated that ash possibly decreased the electrostatic repulsion of deprotonated phenolic hydroxyl between biochars and triclosan. Accordingly, it will be more valuable to design biochars for pollutant sorption from the perspective of combined role of carbonaceous fraction and ash rather than a single role of carbonaceous fraction., (© 2020 The Authors. Journal of Environmental Quality © 2020 American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America.)

The discrete unified gas kinetic scheme (DUGKS) with a force term is a finite volume solver for the Boltzmann equation. Unlike the standard lattice Boltzmann method (LBM), DUGKS can be applied on nonuniform grids. For both the LBM and DUGKS, the boundary conditions need to be processed through the density distribution function. So researchers introduced the boundary conditions from the LBM frame into the DUGKS. However, the accuracy of these boundary conditions in the DUGKS has not been studied thoroughly. Through strict theoretical deduction, we find that the bounce-back (BB) scheme leads to a different dependence of the numerical error term in the DUGKS as compared to the LBM. The error term is influenced by the relaxation time and the body force. And it can be reduced by lowering the kinetic viscosity. Unlike the BB scheme, the nonequilibrium bounce-back scheme has the ability to implement real no-slip boundary condition. Furthermore, two slip boundary conditions incorporated with Navier's slip model are introduced from the LBM framework into the DUGKS. The tangential momentum change-based (TMAC) scheme can be used directly in the DUGKS because it generates no numerical error term in the DUGKS. For the combination of the bounce-back and specular reflection schemes (BSR), the relation between the slip length and the combination parameter should be modified in accordance with the numerical error term. Analysis shows that the TMAC scheme can simulate a wider range of slip length than the BSR scheme. Numerical simulations of the Couette flow and the Poiseuille flow confirm our theoretical analysis.

Currently, it is still lack of systematic and in-depth knowledge regarding the co-effect of carbon-based fractions and ash in the sorption behavior of biochars. Therefore, pristine wood-derived biochars (PBCs) produced at different temperatures and their corresponding de-ashed versions (DBCs) were used to determine the roles of carbon's morphological structure and ash in sorption of aromatic compounds (toluene, m-toluidine, and m-nitrotoluene) to biochars. The results showed that biochars produced at 300-400 °C (mainly uncarbonized organic matter, UCOM) and 900 °C (turbostratic carbon, TC) may have stronger partition effect and pore filling effect with π-π interaction, respectively, and thus have greater sorption coefficients (Lg K d ) than biochars produced at 600 °C (pyrogenic amorphous carbon, PAC), which are probably dominated by surface hydrophobic effect. Meanwhile, TC had a greater Lg K d than UCOM at low adsorbate concentrations (C e ), but exhibited an opposite trend at high C e . The Lg K d values of DBCs are always greater than those of PBCs, indicating ash has an inhibitory effect on sorption of aromatic compounds to biochars. Furthermore, the role of ash in sorption behavior of PBCs would vary with solution pH. At a neutral pH, PBCs have the maximum sorption quantity for aromatic compounds due to the formed cation-π bond between cations of ash and aromatic compounds. However, the acidic pH enhanced the dissolution of cations in ash and the basic pH enhanced the hydroxylation of cations in ash. Therefore, both acidic and basic pH weakened the cation-π bond between ash and aromatic compounds and decreased the sorption of aromatic compounds on PBCs. The results suggest that de-ashed biochars with more UCOM or TC are effective sorbents for sequestration of aromatic compounds, and provide a well-designed method for improving the sorption efficiency of biochars., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Amino sugars (AS) are routinely used as microbial biomarkers to investigate the dynamics of soil carbon (C) and nitrogen (N) under different environments. However, the effect of any AS on soil C and N, or other AS, is not well-defined. In this study, acid soils from Dongbei (D) and Fujian (F) and alkaline soil from Henan (H) were selected to perform an incubation experiment under glucosamine addition for 36 days. In the present study, the dynamics of soil soluble organic C (SOC), NH 4 + -N, NO 3 - -N, soluble organic N (SON), and four AS: glucosamine (GluN), mannosamine (ManN), galactosamine (GalN), and muramic acid (MurN), were investigated. The results showed that AS was different among the three soils, but had similar dynamics in the same soil. The higher total C and inorganic N in the D and F relative to the H soil were related to the greater AS in two soils. With incubation, AS decreased in D soil and increased in F soil before 1 week, while after 1 week, the inverse dynamics were observed, which suggest that SOC or SOC combined with inorganic N may be a mechanism to adjust the dynamics of C from AS. Overall, glucosamine addition did not significantly affect AS in D, while the reverse was true for F and H soils. Glucosamine addition decreased AS at day 0 for D soil and at day 3 for F and H soils, and increased SOC. The lowered NH 4 + -N and AS in D soil, but the higher values of these, were observed in F soil after 1 week of incubation. The increase of SON in D soil with glucosamine addition might be due to the depolymerization of soil organic matter (SOM) into SON. However, the decrease of SON in F soil could be attributed to the mineralization of SON.

Episodic haze is frequently observed in Zhengzhou, China. Such haze typically contains secondary inorganic aerosols. In this paper, we explore the formation mechanisms of sulfate, nitrate, and ammonium (SNA) in Zhengzhou from January 3 to 25, 2018 based on the results of a series of online instruments and a size-segregated filter sampler. Our results document the remarkable contributions of SNA to winter haze episodes in Zhengzhou, where they account for about 50% of PM 2.5 mass concentration. SNA were mainly concentrated in droplet-mode particles, which increased remarkably with the aggravation of the haze episode. In addition, KNO 3 and NaNO 3 were formed in droplet-mode particles and coarse-mode particles respectively with increasing PM 2.5 concentration. The atmosphere during the observation period was ammonia-rich, and the aerosol was acidic under high PM 2.5 concentration. Homogeneous reactions dominated the formation of nitrate. HONO photolysis played a more important role in the origin of OH radicals when O 3 decreased during haze episode. Under high relative humidity (RH), nitrate formation was influenced by heterogeneous hydrolysis reactions of N 2 O 5 . Sulfates were mainly formed through aqueous-phase reactions, especially when the RH was higher than 60%. Under these conditions, there were amounts of liquid water content existed in aerosols. Finally, we observed enhanced conversion of SO 2 and NO 2 during snowfall periods. This effect may be attributable to the higher RH and O 3 levels despite the unfavorable effects of wet deposition and low concentrations of gaseous precursors., (Copyright © 2019. Published by Elsevier B.V.)

Ash in biochar has great influence on the characteristics of biochars. This study systematically compared the differences in physico-chemical properties between pristine biochars (PBCs) and deashed biochars (DBCs) produced at different temperatures (300-900 °C), and specifically analyzed their different advantages in environmental applications. In terms of all the PBCs and DBCs, PBC of 900 °C and the corresponding DBC have the highest degree of graphitization that is recalcitrant in environment, they are benefit for carbon sequestration. PBC of 300 °C and the corresponding DBC have the highest content of O-containing functional groups and aliphaticity that is labile in environment, they are potential carbon source for the growth of soil organisms. PBCs of 300-400 °C have the greatest releasable PO 4 3- content (0.418-0.441 mg/g), and PBCs of 700-900 °C have highest pH (9.28-9.59) and mineral elements content (11.58-12.64 mg/g), they are potential provision of P, and acid soil amendments with potential provision of mineral elements, respectively. DBCs of 300-400 °C possess less competitive cations including Ca, Mg, Al, Fe, and Zn (1.49-2.01 mg/g) and highest content of O-containing functional groups, they are good sorbents for heavy metals, meanwhile these DBCs have the lowest pH (4.49-4.70) that are potential amendments for alkaline soil. Moreover, DBCs of 900 °C have the highest surface area (SA) (351 m 2 /g), the most developed porosity, and the highest releasable NH 4 + content (0.052 mg/g), they are good sorbents for hydrophobic organic pollutants and potential provision of N. This study gives an effective guidance for selecting the suitable biochars-design (deashing or non-deashing) according to their applications in environment., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Currently, the role of amorphous carbon structure (ACS) in sorption of chlorinated hydrocarbons (CHs) to biochars remains little known. Therefore, three CHs (1,1,2,2-tetrachloroethane, 1,3,5-trichlorobenzene and γ-hexachlorocyclohexane) with different molecular properties were selected as model adsorbates to investigate the effect of ACS on sorption of CHs to biochars produced at seven different pyrolysis temperatures (300-900 °C). There were two main mechanisms for ACS controlling the sorption of CHs. First, the polar sites on ACS are hydrophilic, CHs with greater polarity could strongly compete with the water molecule for the hydrophilic sites. Second, ACS of low temperature (300-400 °C) produced biochars possessing the natural organic matter (NOM)-like structure occupied some hydrophobic sites on condensed graphitic structure (CGS) of biochars. CHs with great hydrophobicity possibly seized the hydrophobic sorption sites on CGS from the NOM-like structure. Therefore, ACS of biochar was more benefit for sorption of strong polar CHs (1,1,2,2-tetrachloroethane: π ∗  = 0.95; LogK ow  = 2.39) or strong hydrophobic CHs (1,3,5-trichlorobenzene: π ∗  = 0.70; LogK ow  = 4.19) than CHs (γ-hexachlorocyclohexane: π ∗  = 0.68; LogK ow  = 3.72) with relatively low polarity and hydrophobicity. The result reflects that the interaction between NOM and natural black carbon/biochars in soil and water environment possibly plays the similar role in controlling the environmental behavior of various polar or hydrophobic organic pollutants. Moreover, with increasing concentration of adsorbate (C e ), the first mechanism enhanced, while the second mechanism weakened. This study gives a deep insight into the roles of ACS of biochars in controlling the fate and availability of CHs with different molecular properties in environment., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

A new analytical method, pressurized capillary electrochromatography with indirect amperometric detection, has been developed for the determination of some non-electroactive organophosphorus pesticides (OPPs). When 0.1 mmol L(-1) of 3,4-dihydroxybenzylamine (DHBA) was added to the mobile phase containing 50% v/v of ACN and 50% v/v of MES buffer (10 mmol L(-1), pH 5.5), and +0.9 V (vs. Ag/AgCl) of working potential were used, maximal signal levels of analytes could be achieved. A separation voltage of +10 kV, a column pressure of 7.0 MPa and a pump flow rate of 0.05 mL min(-1) were selected as the other optimal conditions for separation of six OPPs, namely, dimethoate, methyl parathion, ethyl parathion, chlorpyrifos, chlorpyrifos-methyl, trichlorfon. The OPPs could be separated within 15 min and determined with the detection limits ranging from 0.008 to 0.2 mg/kg. Combining with a solid phase extraction procedure, mean recoveries between 78.9 and 87.2% for vegetable samples and from 81.4 to 98.6% for fruit samples were obtained.