Publications by authors named "Xuewei Liu"

78 Publications

Tumor Necrosis Factor-α 308 G/A polymorphism and psoriasis risk: A pooled analysis in different populations.

Medicine (Baltimore) 2020 Nov;99(47):e22339

Department of Dermatology, Henan University of Chinese Medicine First Affiliated Hospital, Zhengzhou, Henan, China.

More and more researches have been carried out on the association between the tumor necrosis factor-α (TNF-α) 308 G/A polymorphism and psoriasis, however, controversial results have emerged in these studies. This meta-analysis was performed to quantitatively clarify the relationship between TNF-α 308 G/A polymorphism and the risk of psoriasis in different populations. Databases of PubMed, Springer Link, Ovid, Chinese Wanfang Data Bases, Chinese National Knowledge Infrastructure and Chinese Biology Medicine were investigated until June 2019. The association between the TNF-α 308 G/A polymorphism and psoriasis was evaluated by calculating the pooled odds ratio (OR) and 95% confidence intervals (CIs). A total of 26 studies including 3657 patients and 3197 controls were screened out. In the overall population, the pooled results showed a reduced psoriasis risk with the TNF-α 308 G/A polymorphism (A vs G: OR = 0.77, 95% CI = 0.67-0.89; AA+GA vs GG: OR = 0.72, 95% CI = 0.61-0.86). In the subgroup analysis stratified by geographic locations, the TNF-α 308 G/A polymorphism was significantly associated with a reduced risk of psoriasis in Germany (A vs G: OR = 0.67, 95% CI = 0.57-0.78; AA+GA vs GG: OR = 0.62, 95% CI = 0.52-0.75), as well as in China (AA+GA vs GG: OR = 0.71, 95% CI = 0.52-0.98) and Poland (A vs G: OR = 0.61, 95% CI = 0.38-0.97; AA+GA vs GG: OR = 0.59, 95% CI = 0.35-0.99). This study indicated a significantly reduced psoriasis risk associated with the TNF-α 308 G/A polymorphism in Germans, as well as in Chinese and Poles populations compared with other populations. Ethnicity and geographic locations probably play a pivotal role in the genetic association of psoriasis.
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http://dx.doi.org/10.1097/MD.0000000000022339DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7676592PMC
November 2020

Tomatidine inhibits porcine epidemic diarrhea virus replication by targeting 3CL protease.

Vet Res 2020 Nov 11;51(1):136. Epub 2020 Nov 11.

Key Laboratory of Animal Disease Diagnostics and Immunology, Ministry of Agriculture, MOE International Joint Collaborative Research Laboratory for Animal Health & Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, 210095, China.

Porcine epidemic diarrhea virus (PEDV) causes lethal diarrhea in suckling piglets, leading to severe economic losses worldwide. There is an urgent need to find new therapeutic methods to prevent and control PEDV. Not only is there a shortage of commercial anti-PEDV drugs, but available commercial vaccines fail to protect against highly virulent PEDV variants. We screened an FDA-approved library of 911 natural products and found that tomatidine, a steroidal alkaloid extracted from the skin and leaves of tomatoes, demonstrates significant inhibition of PEDV replication in Vero and IPEC-J2 cells in vitro. Molecular docking and molecular dynamics analysis predicted interactions between tomatidine and the active pocket of PEDV 3CL protease, which were confirmed by fluorescence spectroscopy and isothermal titration calorimetry (ITC). The inhibiting effect of tomatidine on 3CL protease was determined using cleavage visualization and FRET assay. Tomatidine-mediated blocking of 3CL protease activity in PEDV-infected cells was examined by western blot detection of the viral polyprotein in PEDV-infected cells. It indicates that tomatidine inhibits PEDV replication mainly by targeting 3CL protease. In addition, tomatidine also has antiviral activity against transmissible gastroenteritis virus (TGEV), porcine reproductive and respiratory syndrome virus (PRRSV), encephalo myocarditis virus (EMCV) and seneca virus A (SVA) in vitro. These results may be helpful in developing a new prophylactic and therapeutic strategy against PEDV and other swine disease infections.
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http://dx.doi.org/10.1186/s13567-020-00865-yDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7656508PMC
November 2020

PRV-encoded UL13 protein kinase acts as an antagonist of innate immunity by targeting IRF3-signaling pathways.

Vet Microbiol 2020 Nov 28;250:108860. Epub 2020 Sep 28.

Key Laboratory of Animal Diseases Diagnostic and Immunology, Ministry of Agriculture, MOE International Joint Collaborative Research Laboratory for Animal Health & Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, China; Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou, China. Electronic address:

Pseudorabies virus (PRV), a porcine alphaherpesvirus, causes neurological disorders and reproductive failure in swine. It is capable of avoiding host antiviral responses, resulting in viral latency in infected animals. The mechanisms by which many PRV proteins help the virus to evade immune surveillance are poorly understood. In this study, we found that the PRV protein kinase, UL13, inhibits the IFN-β signaling pathway by targeting interferon regulatory factor 3 (IRF3) for ubiquitination and degradation. PRV with mutant of UL13 is impaired in its ability to hinder IRF3 and interferon-β (IFN-β) activation, and has significantly less pathogenesis in mice that wild-type PRV. Our findings reveal an as yet undescribed mechanism utilized by PRV to evade host immune responses. PRV UL13 is a potential target for attenuated vaccines and antiviral drugs.
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http://dx.doi.org/10.1016/j.vetmic.2020.108860DOI Listing
November 2020

Porcine reproductive and respiratory syndrome virus Nsp4 cleaves ZAP to antagonize its antiviral activity.

Vet Microbiol 2020 Nov 29;250:108863. Epub 2020 Sep 29.

Key Laboratory of Animal Diseases Diagnostic and Immunology, Ministry of Agriculture, MOE International Joint Collaborative Research Laboratory for Animal Health & Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, China; Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou, China. Electronic address:

Porcine reproductive and respiratory syndrome virus (PRRSV) is one of the most economically important pathogens impacting the global swine industry. PRRSV has been recognized to modulate the host immune response through a number of mechanisms. In our previous study, we found that over-expression of ZAP, a zinc finger antiviral protein of host, could suppress PRRSV replication, but how PRRSV escape the restriction of ZAP under natural conditions was still unknown. In this study, We found PRRSV infection significantly down-regulate the endogenous ZAP protein expression in Marc-145 cells. And PRRSV nonstructural protein 4 (Nsp4), a 3C-like serine proteinase, was screened to be responsible for ZAP reduction. Nsp4 could cleave ZAP, depending on its protease activity. The anti-PRRSV activity of ZAP was antagonized by Nsp4 in Marc-145 cells. In addition, we identified a unique amino acid, serine 180 of Nsp4 was required for efficient degradation of ZAP, and the mutation at residue 180 could decrease the ability of recombinant PRRSV to degrade ZAP. Those findings reveal a manner of PRRSV Nsp4 antagonizing the antiviral activity of ZAP, and shed light on a new strategy evolved by PRRSV to escape the host defense.
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http://dx.doi.org/10.1016/j.vetmic.2020.108863DOI Listing
November 2020

Analysis of Damage and Permeability Evolution for Mudstone Material under Coupled Stress-Seepage.

Materials (Basel) 2020 Aug 25;13(17). Epub 2020 Aug 25.

State Key Laboratory of Geomechanics and Geotechnical Engineering, Institute of Rock and Soil Mechanics, Chinese Academy of Sciences, Wuhan 430071, China.

Mudstone material in a deep roadway is under the coupled stress-seepage condition. To investigate the permeability change and damage development during rock excavation in roadways, a stress-seepage damage coupling model has been proposed. In this model, damage capacity expansion of mudstone material is considered as the initiation and propagation of micro-cracks and the fracture penetration. A damage variable is introduced into the proposed model based on the principle of minimum energy consumption. As a result, an elastoplastic damage constitutive equation is established. Then, the permeability evolution equation describing the micro-macro hydraulic behavior of mudstone is deduced via percolation theory, which can describe the characteristics of sudden permeability change after rock capacity expansion. Furthermore, a finite element model is established based on commercial finite element software-ABAQUS. The numerical model was firstly verified by comparison between experimental and simulation results. On the basis of it, numerical investigation of the temporal and spatial evolution law of pore pressure, damage and permeability coefficient during roadway excavation is undertaken. The numerical results indicate that with increase of construction time, pore pressure first increases and then decreases, while the damage zone and permeability coefficient increase gradually and finally nearly keep constant. The proposed coupling model and finite element method can describe damage and permeability evolution for mudstone material under coupled stress-seepage well.
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http://dx.doi.org/10.3390/ma13173755DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7504363PMC
August 2020

Improving the production of AHL lactonase AiiO-AIO6 from Ochrobactrum sp. M231 in intracellular protease-deficient Bacillus subtilis.

AMB Express 2020 Aug 5;10(1):138. Epub 2020 Aug 5.

Sino-Norwegian Fish Gastrointestinal Microbiota Joint Lab, Feed Research Institute, Chinese Academy of Agricultural Sciences, Beijing, 100081, China.

Quorum quenching (QQ) blocks bacterial cell-to-cell communication (i.e., quorum sensing), and is a promising antipathogenic strategy to control bacterial infection via inhibition of virulence factor expression and biofilm formation. QQ enzyme AiiO-AIO6 from Ochrobactrum sp. M231 has several excellent properties and shows biotherapeutic potential against important bacterial pathogens of aquatic species. AiiO-AIO6 can be secretory expressed in Bacillus subtilis via a non-classical secretion pathway. To improve AiiO-AIO6 production, four intracellular protease-deletion mutants of B. subtilis 1A751 were constructed by individually knocking out the intracellular protease-encoding genes (tepA, ymfH, yrrN and ywpE). The AiiO-AIO6 expression plasmid pWB-AIO6BS was transformed into the B. subtilis 1A751 and its four intracellular protease-deletion derivatives. Results showed that all recombinant intracellular protease-deletion derivatives (BSΔtepA, BSΔymfH, BSΔyrrN and BSΔywpE) had a positive impact on AiiO-AIO6 production. The highest amount of AiiO-AIO6 extracellular production of BSΔywpE in shake flask reached 1416.47 U/mL/OD, which was about 121% higher than that of the wild-type strain. Furthermore, LC-MS/MS analysis of the degrading products of 3-oxo-C8-HSL by purification of AiiO-AIO6 indicated that AiiO-AIO6 was an AHL-lactonase which hydrolyzes the lactone ring of AHLs. Phylogenetic analysis showed that AiiO-AIO6 was classified as a member of the α/β hydrolase family with a conserved "nucleophile-acid-histidine" catalytic triad. In summary, this study showed that intracellular proteases were responsible for the reduced yields of heterologous proteins and provided an efficient strategy to enhance the extracellular production of AHL lactonase AiiO-AIO6.
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http://dx.doi.org/10.1186/s13568-020-01075-7DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7406587PMC
August 2020

Metformin alleviates experimental colitis in mice by up-regulating TGF-β signaling.

Biotech Histochem 2021 Feb 13;96(2):146-152. Epub 2020 Jul 13.

Department of Stomatology, Beijing Bo'ai Hospital, China Rehabilitation Research Center, School of Rehabilitation, Capital Medical University , Beijing, China.

Ulcerative colitis is an inflammatory condition of the colon. Metformin, an antidiabetic drug, can suppress the inflammatory cascade. We investigated the effects of metformin on experimental colitis. Experimental colitis was induced in mice using dextran sulfate sodium. We used three groups of mice: untreated control, saline treated and metformin treated. We measured weight, disease activity index, colon length, levels of inflammatory cytokines, and we evaluated tissue histology. We found that metformin treatment decreased colon mucosal damage and preserved intestinal transit. We also found increased tissue levels of CD4+ Foxp3+ regulatory T cells (Treg), transforming growth factor-β1(TGF-β1) and pSmad2/3, and reduced expression of Th17 and IL-17. Metformin exhibited therapeutic potential for treating inflammatory conditions of the colon by targeting the immunoregulatory cytokine, TGF-β1.
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http://dx.doi.org/10.1080/10520295.2020.1776896DOI Listing
February 2021

Ophiostomatoid fungi associated with , including eight new species from northeastern China.

IMA Fungus 2020 31;11. Epub 2020 Jan 31.

Key Laboratory of Forest Protection, National Forestry and Grassland Administration; Research Institute of Forest Ecology, Environment and Protection, Chinese Academy of Forestry, Beijing, 100091 China.

is a major pest that infects larch plantations over large areas of northern and northeastern China. species are closely associated with ophiostomatoid fungi that are morphologically well-adapted for dispersal by beetles. These associations result in important threat for coniferous forests worldwide. The aim of this study was to characterize the ophiostomatoid communities associated with infesting species and sympatric var. in northeastern China forests. Morphological and multilocus phylogenetic approaches (based on six markers: ITS, LSU, 60S, β-tubulin, EF-1α, and CAL gene regions) allowed identifying 14 species of four genera (, , and ). Eight species are showed to be new to science. Most strains resided in two species complexes, viz. the and the complexes, all together accounting for 76.8% of all isolates. sp. nov., sp. nov., and sp. nov. ( complex) and sp. nov. ( complex) were the four dominant species. The ophiostomatoid communities associated with larch bark beetles, and , in Europe and Asia, China and Japan, also were compared. These comparisons showed distinct, specific assemblage patterns.
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http://dx.doi.org/10.1186/s43008-019-0025-3DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7325231PMC
January 2020

Efficacy and safety outcomes in novel oral anticoagulants versus vitamin-K antagonist on post-TAVI patients: a meta-analysis.

BMC Cardiovasc Disord 2020 06 26;20(1):307. Epub 2020 Jun 26.

Department of Cardiology, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong, China.

Background: Transcatheter aortic valve implantation (TAVI) has been a favored option for the patient who suffered from symptomatic aortic stenosis. However, the efficacy and safety outcomes in novel oral anticoagulants (NOACs) versus Vitamin-K antagonist (VKA) for post-TAVI patients are still controversial. This meta-analysis aims at comparing the clinical outcome and safety of NOACs and VKA in the patients after receiving TAVI.

Method: We searched literature articles in all reachable databases, and observational study as well as randomized controlled trial would be included in order to perform a comprehensive analysis. All-cause mortality, major or life-threatening bleeding, disabling or nondisabling stroke were main pooled outcome measures. Subgroup analysis and meta-regression were adopted to explore heterogeneity. Assessment of bias was performed under the suggestion of Cochrane's Collaboration Tool.

Results: We collected 3841 non-duplicate citations from PubMed, Embase, Cochrane and ClinicalTrials.gov, and eventually 7 studies were included for this meta-analysis. As a result, VKA showed priority against NOACs in the field of anti-thromboembolism (4435 participants, RR:1.44, 95% CI: 1.05 to 1.99, I = 0%, P = 0.02).

Conclusion: With corroborative analysis of severe complications, VKA is shown to be more protective on post-TAVI patients in disabling or nondisabling stroke scenario but not in mortality or bleeding event.
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http://dx.doi.org/10.1186/s12872-020-01582-2DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7318737PMC
June 2020

Enhancing β-Carotene Production in by Perturbing Central Carbon Metabolism and Improving the NADPH Supply.

Front Bioeng Biotechnol 2020 9;8:585. Epub 2020 Jun 9.

Synthetic Biology and Key Laboratory of Systems Bioengineering (Ministry of Education), Tianjin, China.

Beta (β)-carotene (CH; a provitamin) is a particularly important carotenoid for human health. Many studies have focused on engineering as an efficient heterologous producer of β-carotene. Moreover, several strains with potential for use in the industrial production of this provitamin have already been constructed via different metabolic engineering strategies. In this study, we aimed to improve the β-carotene-producing capacity of our previously engineered strain ZF43Δ through further gene deletion and metabolic pathway manipulations. Deletion of the gene increased the resultant strain's β-carotene production and content by 5.1 and 32.5%, respectively, relative to the values of strain ZF43Δ, but decreased the biomass by 26.2%. Deletion of the operon further increased the β-carotene production titer from 122.0 to 197.4 mg/L, but the provitamin content was decreased. Subsequently, comparative transcriptomic analysis was used to explore the dynamic transcriptional responses of the strains to the blockade of the pentose phosphate pathway and inactivation of the phosphotransferase system. Lastly, based on the analyses of comparative transcriptome and reduction cofactor, several strategies to increase the NADPH supply were evaluated for enhancement of the β-carotene content. The combination of gene deletion and overexpression led to increased β-carotene production and content. The best strain, ECW4/p5C-, produced 266.4 mg/L of β-carotene in flask culture and 2,579.1 mg/L in a 5-L bioreactor. The latter value is the highest reported from production via the methylerythritol phosphate pathway in . . Although the strategies applied is routine in this study, the combinations reported were first implemented, are simple but efficient and will be helpful for the production of many other natural products, especially isoprenoids. Importantly, we demonstrated that the use of the methylerythritol phosphate pathway alone for efficient β-carotene biosynthesis could be achieved via appropriate modifications of the cell metabolic functions.
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http://dx.doi.org/10.3389/fbioe.2020.00585DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7296177PMC
June 2020

The mechanism of polystyrene microplastics to affect arsenic volatilization in arsenic-contaminated paddy soils.

J Hazard Mater 2020 11 15;398:122896. Epub 2020 May 15.

Department of Civil and Environmental Engineering, Shantou University, Shantou, 515063, China. Electronic address:

Different concentrations and sizes of polystyrene microplastics (PS-MP) were added to low (25.9) and high (56.8) mg kg As-contaminated soil to investigate the effects of PS-MP on soil As volatilization. Either S (10 μm) or S (0.1-1 μm) PS-MP was added to As-contaminated soil at 0.8%, which increased As volatilization by 13.7% and 7.4% in low As-contaminated soil; and 21.8% and 16.5% in high As-contaminated soil, respectively. The addition of PS-MP reduced the water-soluble (WS) As content, increased the non-specifically-sorbed (NSS), specifically-sorbed (SS) As content, soil catalase (CAT) and urease (UE) activities. The abundance of Proteobacteria and Firmicutes showed opposite trends to As volatilization, while the abundance of Bacteroidetes and arsM gene expression exhibited similar variability to As volatilization over the 7-week experiment. Therefore, we postulate that in As-contaminated soil, As volatilization was enhanced in the presence of PS-MP due to two possible mechanisms: 1) PS-MP affects the abundance of Proteobacteria, Firmicutes, Bacteroidetes, and arsM gene in soil; 2) PS-MP increases As volatilization via reducing soil nutrient and increasing the content of SS As. Our results highlighted the importance of investigating impacts of microplastics on the volatility of specific contaminants to implement effective environmental remediation strategies in polluted farmlands.
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http://dx.doi.org/10.1016/j.jhazmat.2020.122896DOI Listing
November 2020

Alteration in the Function and Expression of SLC and ABC Transporters in the Neurovascular Unit in Alzheimer's Disease and the Clinical Significance.

Aging Dis 2020 Apr 9;11(2):390-404. Epub 2020 Mar 9.

1Department of Neuropharmacology, College of Pharmacy, Qiqihar Medical University, Qiqihar, China.

The neurovascular unit (NVU) plays an important role in maintaining the function of the central nervous system (CNS). Emerging evidence has indicated that the NVU changes function and molecules at the early stage of Alzheimer's disease (AD), which initiates multiple pathways of neurodegeneration. Cell types in the NVU have become attractive targets in the interventional treatment of AD. The NVU transportation system contains a variety of proteins involved in compound transport and neurotransmission. Brain transporters can be classified as members of the solute carrier (SLC) and ATP-binding cassette (ABC) families in the NVU. Moreover, the transporters can regulate both endogenous toxins, including amyloid-beta (Aβ) and xenobiotic homeostasis, in the brains of AD patients. Genome-wide association studies (GWAS) have identified some transporter gene variants as susceptibility loci for late-onset AD. Therefore, the present study summarizes changes in blood-brain barrier (BBB) permeability in AD, identifies the location of SLC and ABC transporters in the brain and focuses on major SLC and ABC transporters that contribute to AD pathology.
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http://dx.doi.org/10.14336/AD.2019.0519DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7069460PMC
April 2020

Historic Trends and Future Prospects of Waste Generation and Recycling in China's Phosphorus Cycle.

Environ Sci Technol 2020 04 1;54(8):5131-5139. Epub 2020 Apr 1.

School of Management Science and Engineering, Nanjing University of Information Science and Technology, Nanjing 210044, PR China.

Intensified human activities have generated a large amount of phosphorus-containing waste (P waste). Unrecycled P waste is lost to the environment and causes eutrophication, while the increasing phosphate consumption risks the depletion of phosphorus resources. The management of P waste is critical to solving these problems. In this study, we quantified the historic trends of P waste generation and recycling in China. From 1900 to 2015, the annual generation of P waste increased from 1 Mt P to 12 Mt P. Crop farming was the largest P waste source in most years, while P waste from phosphate mining and phosphorus chemical production increased the fastest. The total recycled P waste increased 5-fold, but phosphorus loss increased 26-fold. In 2015, 28% of the P waste was lost on cultivated land, and 21% was lost on nonarable land. The largest phosphorus contributor to inland water changed from crop farming to aquaculture. The full recycling of P waste would have reduced phosphate consumption by more than one-third in 2015. The results of a scenario analysis showed that a healthier diet would greatly increase the generation and loss of P waste, but balanced fertilization could reduce the generation of P waste by 17% and promoting waste recycling could reduce the phosphorus loss by 35%.
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http://dx.doi.org/10.1021/acs.est.9b05120DOI Listing
April 2020

Effects of Fe-Mn-Ce oxide-modified biochar on As accumulation, morphology, and quality of rice (Oryza sativa L.).

Environ Sci Pollut Res Int 2020 May 14;27(15):18196-18207. Epub 2020 Mar 14.

Department of Civil and Environmental Engineering, Shantou University, Shantou, 515063, China.

The fluidity of arsenic (As) in soil used for rice cultivation under flooding conditions is the main reason for its high accumulation in rice, which poses a serious threat to human's health. Biochar can immobilize heavy metal (for example lead) of soil because of the strong binding of heavy metals to the inner biochar particles. We conducted a pot experiment to evaluate the effects of biochar (BC) and Fe-Mn-Ce oxide-modified biochar composites (FMCBCs) on the morphology, As accumulation, and grain quality of rice grown in As-contaminated soils. The biochar and FMCBC treatments significantly increased the dry weight of roots, stems, leaves, and rice grains grown in As-contaminated soil (P < 0.05). The As concentration in different parts of rice was significantly lower with treatment FMCBC (BC, Fe, Mn, and Ce weight ratio of 24:2:3:10) than with the BC and control (no BC) treatments. The application of FMCBC maximized the yield and quality of rice grains: rice grain yields were 61.45-68.41% higher over control and the proportion of essential amino acids in the rice grains was 31.01-44.62%. The application of FMCBCs also increased the concentration of Fe-Mn plaques, which prevent the uptake of As by rice, thereby mitigating the toxic effects of As-contaminated soil on rice. In summary, Fe-Mn-Ce oxide-modified BC composites fixed As, reducing its fluidity and the As concentration in rice. Our results show that FMCBC could play an important role in reducing As accumulation and increasing the grain yield and quality of rice, thus ensuring food safety in regions contaminated with As.
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http://dx.doi.org/10.1007/s11356-020-08355-6DOI Listing
May 2020

Influence of the application of Fe-Mn-La ternary oxide-biochar composites on the properties of arsenic-polluted paddy soil.

Environ Sci Process Impacts 2020 Apr;22(4):1045-1056

Agro-Environmental Protection Institute, Ministry of Agriculture of China, Tianjin, 300191, China.

Arsenic exists ubiquitously in the soil and has been proved to be of significant hazard to human health upon transmission through food chain. Herein, we determined the effects of Fe-Mn-La ternary oxide-biochar composites (FMLBCs) on arsenic (As) fractionation, soil enzyme activities, and microbial communities in arsenic-polluted soils. The results demonstrated that the proportion of non-swappable As fractions reduced and that of the exchangeable As fractions increased with the addition of FMLBCs. Furthermore, the addition of FMLBCs significantly increased the catalase (CAT) activity (P < 0.05), and an increase of 69.2-268% was observed when 2 wt% FMLBCs were added. Supplementation with biochar or FMLBCs increased the relative abundance of Proteobacteria and Acidobacteria and decreased the relative abundance of Firmicutes; moreover, the effect was more obvious as the addition amount of biochar or FMLBCs increased. In addition, the FMLBCs, except for FMLBC3, increased the content of available phosphorus. Moreover, amendments of FMLBCs led to an increase in the available potassium content by an average of 212%, 113%, and 62.1% in highly polluted soil. Therefore, the FMLBCs affected the physical and chemical properties of soil in different manners. The results suggested that the addition of FMLBCs changed the distribution and increased the immobilization of As in the soil; this could indirectly reduce the risk of the transport of As to rice. The amendment mechanism of FMLBCs may include changes to the physicochemical soil properties and consequently, the soil enzyme activities are affected, which can influence the microbial communities in soils.
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http://dx.doi.org/10.1039/c9em00570fDOI Listing
April 2020

Kai-Xin-San, a Chinese Herbal Decoction, Accelerates the Degradation of -Amyloid by Enhancing the Expression of Neprilysin in Rats.

Evid Based Complement Alternat Med 2020 21;2020:3862342. Epub 2020 Feb 21.

Department of Neuropharmacology, College of Pharmacy, Qiqihar Medical University, Qiqihar 161006, China.

This study aimed to investigate the mechanisms of Kai-Xin-San (KXS, a famous Chinese herbal decoction used to treat amnesia) on the degradation of A and further elucidate the mechanism of KXS on A-induced memory dysfunction. After pretreatment with KXS (1.08 g/kg/day) for two weeks, A (2 L, 200 M) was injected into rat hippocampus to induce cognitive dysfunction. Morris water maze (MWM) test was developed to evaluate cognitive performance in rats. Hippocampal neurons were observed by histological staining using Hematoxylin-Eosin (HE) methods. Levels of exogenous A, which was injected into the hippocampus, were continually measured through a special Enzyme-linked immunoassay (ELISA) kit to observe the catabolic process of A in the brain. Similarly, A degradation in PC12 cells was also investigated using the ELISA kit. The expressions of A degeneration enzymes, including neprilysin (NEP), angiotensin-converting enzyme (ACE), and endothelin-converting enzyme (ECE), were detected by western blotting to elucidate A reduction mechanism. Our results showed that KXS prevented A-induced cognitive impairment and attenuated hippocampus neuronal damage caused by A. Moreover, KXS could accelerate A degradation in A injected rats. Furthermore, NEP, an A degradation enzyme, was increased in the hippocampus while ECE and ACE, other two A-degrading enzymes, were not changed. KXS accelerated A degradation in PC12 cells. Our findings revealed that KXS facilitated the degradation of A by increasing the expression of NEP in rat hippocampus. By reducing the A burdens, KXS protected hippocampal neurons, leading to the improvement of cognitive function in rats.
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http://dx.doi.org/10.1155/2020/3862342DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7054802PMC
February 2020

Effect of Fe-Mn-Ce modified biochar composite on microbial diversity and properties of arsenic-contaminated paddy soils.

Chemosphere 2020 Jul 17;250:126249. Epub 2020 Feb 17.

Department of Civil and Environmental Engineering, Shantou University, Shantou, 515063, China. Electronic address:

In this study, we investigated the mechanism of decrease in arsenic (As) bioavailability after addition of biochar (BC) supplemented with iron (Fe)- manganese (Mn)- cerium (Ce) oxide (FMCBC) to As-contaminated paddy soil. We explored the effects of these composites on the oxidation, reduction, microbial community, and soil enzyme activity of As-contaminated paddy soil. Results showed that FMCBCs improve soil pH, significantly improve the redox capacity of soil, and reduce bioavailable forms of As. FMCBCs can convert As from a specifically or non-specifically bound form into amorphous hydrous oxide bound- and crystalline hydrous oxide bound form. The application of FMCBCs increased soil enzyme activity (urease, catalase, alkaline phosphatase, and peroxidase), and greatly influenced the relative abundance of certain microorganisms (Proteobacteria, Acidobacteria, and Gemmatimonadetes), which improved soil enzyme heavy metal tolerance and prevented their denaturation. Thus, FMCBCs can not only change the form and distribution of As in soil but also create an environment suitable for microbial growth, consequently affecting the geochemical cycling of As in soil.
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http://dx.doi.org/10.1016/j.chemosphere.2020.126249DOI Listing
July 2020

Efficient oxidation and adsorption of As(III) and As(V) in water using a Fenton-like reagent, (ferrihydrite)-loaded biochar.

Sci Total Environ 2020 May 27;715:136957. Epub 2020 Jan 27.

The New Zealand Institute for Plant and Food Research Limited, Private Bag 4704, Christchurch 8140, New Zealand.

The by-product of the traditional Fenton reaction, colloidal arsenic-‑iron oxide, is migratable and may cause secondary environmental pollution. This paper reported a new strategy involving oxidizing and immobilizing inorganic arsenic using the Fenton reaction, and avoiding the risk of secondary contamination. Lab synthesized ferrihydrite-loaded biochar (FhBC) was developed for oxidizing and binding As(III) and As(V) in aqueous solution. Batch experiments and a series of spectrum analysis (e.g., X-ray photoelectron spectroscopy [XPS], electron paramagnetic resonance [EPR], and Fourier transform infrared spectroscopy [FTIR]) were conducted to study the oxidizing or adsorption capacity and mechanism. The maximum adsorption capacity of FhBC for As(III) and As(V) is 1.315 and 1.325 mmol/g, respectively. In addition, FhBC has an efficient oxidizing capacity within a wide pH range, which is because biochar promotes the Fenton reaction by acting as an electron donator, electron shuttler, or by providing persistent free radicals. Moreover, the adsorption mechanism was studied by FTIR spectroscopy, XPS, and X-ray diffraction (XRD). The formation of internal spherical complexes and iron oxides with a higher degree of crystallization was observed, which indicate that the products of adsorption are stable and robust in a complex environment and can exist in a highly crystallized form after adsorbing arsenic ions. Therefore, the use of FhBC as an adsorbent for arsenic represents a new strategy of using the Fenton reaction while reducing secondary contamination. These results may contribute to further mechanistic studies or extensive practical applications of FhBC.
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http://dx.doi.org/10.1016/j.scitotenv.2020.136957DOI Listing
May 2020

S100A9 regulates porcine reproductive and respiratory syndrome virus replication by interacting with the viral nucleocapsid protein.

Vet Microbiol 2019 Dec 6;239:108498. Epub 2019 Nov 6.

Key Laboratory of Animal Diseases Diagnostic and Immunology, Ministry of Agriculture, MOE International Joint Collaborative Research Laboratory for Animal Health & Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, China; Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou, China. Electronic address:

Porcine reproductive and respiratory syndrome virus (PRRSV) has caused huge economic losses to the pig industry worldwide over the last 30 years, yet the associated viral-host interactions remain poorly understood. S100A9 is a damage-associated molecular pattern of the S100 protein family. Here, we found that PRRSV infection stimulated S100A9 expression in porcine alveolar macrophages (PAMs) and Marc-145 cells. S100A9 inhibited PRRSV replication via cellular Ca dependent manner. The viral nucleocapsid (N) protein co-localized with S100A9 in the cytoplasm, and directly interacted at amino acid 78 of S100A9 and amino acids 36-37 of N protein. Moreover, we also found that the mutant S100A9 (E78Q) protein exhibited decreased antiviral activity against PRRSV compared with the parent S100A9. Recombinant PRRSV rBB (36/37) with two mutations in amino acid 36-37 in the N protein exhibited greater replication than the parent PRRSV BB0907 in S100A9-overexpressed PAM and Marc-145 cells. Thus, S100A9 may restrict PRRSV proliferation by interacting with the viral N protein.
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http://dx.doi.org/10.1016/j.vetmic.2019.108498DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7125916PMC
December 2019

Disclosing the Mechanism of Spontaneous Aggregation and Template-Induced Misfolding of the Key Hexapeptide (PHF6) of Tau Protein Based on Molecular Dynamics Simulation.

ACS Chem Neurosci 2019 12 12;10(12):4810-4823. Epub 2019 Nov 12.

State Key Laboratory of Quality Research in Chinese Medicine, Macau Institute for Applied Research in Medicine and Health , Macau University of Science and Technology , Taipa , Macau 999078 , China.

The microtubule-associated protein tau is critical for the development and maintenance of the nervous system. Tau dysfunction is associated with a variety of neurodegenerative diseases called tauopathies, which are characterized by neurofibrillary tangles formed by abnormally aggregated tau protein. Studying the aggregation mechanism of tau protein is of great significance for elucidating the etiology of tauopathies. The hexapeptide VQIVYK (PHF6) of R3 has been shown to play a vital role in promoting tau aggregation. In this study, long-term all-atom molecular dynamics simulations in explicit solvent were performed to investigate the mechanisms of spontaneous aggregation and template-induced misfolding of PHF6, and the dimerization at the early stage of nucleation was further specifically analyzed by the Markov state model (MSM). Our results show that PHF6 can spontaneously aggregate to form multimers enriched with β-sheet structure and the β-sheets in multimers prefer to exist in a parallel way. It is observed that PHF6 monomer can be induced to form a β-sheet structure on either side of the template but in a different way. In detail, the β-sheet structure is easier to form on the left side but does not extend well, but on the right side, the monomer can form the extended β-sheet structure. Furthermore, MSM analysis shows that the formation of dimer mainly occurs in three steps. First, the separated monomers collide with each other at random orientations, and then a dimer with short β-sheet structure at the N-terminal forms; finally, β-sheets elongate to form an extended parallel β-sheet dimer. During these processes, multiple intermediate states are identified and multiple paths can form a parallel β-sheet dimer from the disordered coil structure. Moreover, the residues I308, V309, and Y310 play an essential role in the dimerization. In a word, our results uncover the aggregation and misfolding mechanism of PHF6 from the atomic level, which can provide useful theoretical guidance for rational design of effective therapeutic drugs against tauopathies.
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http://dx.doi.org/10.1021/acschemneuro.9b00488DOI Listing
December 2019

Therapeutic effect of Xanthohumol against highly pathogenic porcine reproductive and respiratory syndrome viruses.

Vet Microbiol 2019 Nov 26;238:108431. Epub 2019 Sep 26.

Key Laboratory of Animal Disease Diagnostics and Immunology, Ministry of Agriculture, MOE International Joint Collaborative Research Laboratory for Animal Health & Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, 210095, China; Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou, China. Electronic address:

The infection by porcine reproductive and respiratory syndrome virus (PRRSV) has a severe impact on the world swine industry. However, commercially available vaccines provide only incomplete protection against this disease. Thus, novel approaches to control PRRSV infection are essential for the robust and sustainable swine industry. In our previous study, Xanthohumol (Xn), a prenylated flavonoid extracted for hops (Humulus lupulus L), was screened from 386 natural products to inhibit PRRSV proliferation and alleviate oxidative stress induced by PRRSV via the Nrf2-HMOX1 axis in Marc-145 cells. In this study, we furtherly found that Xn could inhibit PRRSV different sub-genotype strains infection with a low IC value in porcine primary alveolar macrophages (PAMs). In addition, it caused decreased expression of interleukin (IL)-1β, IL-6, IL-8, and tumor necrosis factor-α in PAMs infected with PRRSV or treated with lipopolysaccharide. Animal challenge experiments showed that Xn effectively alleviated clinical signs, lung pathology, and inflammatory responses in lung tissues of pigs induced by highly pathogenic PRRSV infection. The results demonstrate that Xn is a promising therapeutic agent to combat PRRSV infections.
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http://dx.doi.org/10.1016/j.vetmic.2019.108431DOI Listing
November 2019

Computational cytometer based on magnetically modulated coherent imaging and deep learning.

Light Sci Appl 2019 2;8:91. Epub 2019 Oct 2.

1Electrical and Computer Engineering Department, University of California, Los Angeles, CA 90095 USA.

Detecting rare cells within blood has numerous applications in disease diagnostics. Existing rare cell detection techniques are typically hindered by their high cost and low throughput. Here, we present a computational cytometer based on magnetically modulated lensless speckle imaging, which introduces oscillatory motion to the magnetic-bead-conjugated rare cells of interest through a periodic magnetic force and uses lensless time-resolved holographic speckle imaging to rapidly detect the target cells in three dimensions (3D). In addition to using cell-specific antibodies to magnetically label target cells, detection specificity is further enhanced through a deep-learning-based classifier that is based on a densely connected pseudo-3D convolutional neural network (P3D CNN), which automatically detects rare cells of interest based on their spatio-temporal features under a controlled magnetic force. To demonstrate the performance of this technique, we built a high-throughput, compact and cost-effective prototype for detecting MCF7 cancer cells spiked in whole blood samples. Through serial dilution experiments, we quantified the limit of detection (LoD) as 10 cells per millilitre of whole blood, which could be further improved through multiplexing parallel imaging channels within the same instrument. This compact, cost-effective and high-throughput computational cytometer can potentially be used for rare cell detection and quantification in bodily fluids for a variety of biomedical applications.
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http://dx.doi.org/10.1038/s41377-019-0203-5DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6804677PMC
October 2019

Xanthohumol inhibits PRRSV proliferation and alleviates oxidative stress induced by PRRSV via the Nrf2-HMOX1 axis.

Vet Res 2019 Sep 11;50(1):61. Epub 2019 Sep 11.

Key Laboratory of Animal Disease Diagnostics and Immunology, Ministry of Agriculture, MOE International Joint Collaborative Research Laboratory for Animal Health & Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, 210095, China.

Porcine reproductive and respiratory syndrome virus (PRRSV) is a prevalent and endemic swine pathogen that causes significant economic losses in the global swine industry. Commercial vaccines provide limited protection against this virus, and no highly effective therapeutic drugs are yet available. In this study, we first screened a library of 386 natural products and found that xanthohumol (Xn), a prenylated flavonoid found in hops, displayed high anti-PRRSV activity by inhibiting PRRSV adsorption onto and internalization into cells. Transcriptome sequencing revealed that Xn treatment stimulates genes associated with the antioxidant response in the nuclear factor-erythroid 2-related factor 2 (Nrf2) signalling pathway. Xn causes increased expression of Nrf2, HMOX1, GCLC, GCLM, and NQO1 in Marc-145 cells. The action of Xn against PRRSV proliferation depends on Nrf2 in Marc-145 cells and porcine alveolar macrophages (PAMs). This finding suggests that Xn significantly inhibits PRRSV proliferation and decreases viral-induced oxidative stress by activating the Nrf2-HMOX1 pathway. This information should be helpful for developing a novel prophylactic and therapeutic strategy against PRRSV infection.
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http://dx.doi.org/10.1186/s13567-019-0679-2DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6737628PMC
September 2019

Enhanced As(III) removal from aqueous solution by Fe-Mn-La-impregnated biochar composites.

Sci Total Environ 2019 Oct 3;686:1185-1193. Epub 2019 Jun 3.

The New Zealand Institute for Plant and Food Research Limited, Private Bag 4704, Christchurch 8140, New Zealand.

A novel Fe-Mn-La-impregnated biochar composite (FMLBC) was synthesized using an impregnation method for efficient As (III) adsorption. The pseudo-second-order model (R values are 0.996, 0.996, and 0.994 for different FMLBC rate used) better fitted the kinetic adsorption of arsenic (As) on the FMLBC than the pseudo-first order model (R values are 0.978, 0.971, and 0.991 respectively). The SEM-EDS, FTIR and XPS results confirmed the addition of Fe, Mn and La into the BC structure. Compared with pristine biochar (3.73 mg g) and Fe-Mn-impregnated biochar (9.48 mg g), the As (III) adsorption capacity of Fe-Mn-La impregnated biochar (14.9 mg g) was significantly improved. The presence of NO and SO did not influence As adsorption, whereas PO influenced As removal. The mechanism of As adsorption on the FMLBC involved oxidization, electrostatic attraction, ligand exchange, and formation of an inner-sphere R-O-As complex. Among them, the electrostatic attraction and inner-sphere complexation contributed the most. The simple preparation process and high adsorption performance suggest that the FMLBC could be served as a promising adsorbent for As (III) removal from aqueous solution.
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http://dx.doi.org/10.1016/j.scitotenv.2019.05.480DOI Listing
October 2019

Combinatorial expression of different β-carotene hydroxylases and ketolases in Escherichia coli for increased astaxanthin production.

J Ind Microbiol Biotechnol 2019 Nov 11;46(11):1505-1516. Epub 2019 Jul 11.

Frontier Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering (Ministry of Education), SynBio Research Platform, Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072, People's Republic of China.

In natural produced bacteria, β-carotene hydroxylase (CrtZ) and β-carotene ketolase (CrtW) convert β-carotene into astaxanthin. To increase astaxanthin production in heterologous strain, simple and effective strategies based on the co-expression of CrtZ and CrtW were applied in E. coli. First, nine artificial operons containing crtZ and crtW genes from different sources were constructed and, respectively, introduced into E. coli ZF237T, a β-carotene producing host. Among the nine resulting strains, five accumulated detectable amounts of astaxanthin ranging from 0.49 to 8.07 mg/L. Subsequently, the protein fusion CrtZ to CrtW using optimized peptide linkers further increased the astaxanthin production. Strains expressing fusion proteins with CrtZ rather than CrtW attached to the N-terminus accumulated much more astaxanthin. The astaxanthin production of the best strain ZF237T/CrtZ-(GS)-W was 127.6% and 40.2% higher than that of strains ZF237T/crtZW and ZF237T/crtZW, respectively. The strategies depicted here also will be useful for the heterologous production of other natural products.
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http://dx.doi.org/10.1007/s10295-019-02214-1DOI Listing
November 2019

Long-term estrogen deprivation changes the response to antianxiety drugs in mice in the elevated plus maze test.

Gynecol Endocrinol 2019 Dec 13;35(12):1054-1058. Epub 2019 Jun 13.

Department of Neuropharmacology, College of Pharmacy, Qiqihar Medical University, Qiqihar, China.

Estrogen deficiency increases the incidence of female anxiety disorders; however, whether estrogen deficiency alters responses to anxiolytic drugs is unknown. We studied whether long-term estrogen deprivation (ovariectomy, OVX) changes the behavior of mice to anxiolytic drugs (buspirone, diazepam, and venlafaxine), using the elevated plus maze (EPM) test. The percentages of EPM open-arm time and EPM open-arm entries of the OVX mice decreased significantly compared to control, and sham mice 2 months after OVX. The response to buspirone increased in the OVX mice at 1 week, while OVX decreased the response to diazepam at 2 months. Moreover, we found the efficacy of diazepam was significantly decreased, compared to buspirone and venlafaxine, at 2 months. These results suggest that OVX may change responses to different anxiolytic drugs. Not all anti-anxiety drugs appear to be suitable for anxiety caused by estrogen deficiency.
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http://dx.doi.org/10.1080/09513590.2019.1617266DOI Listing
December 2019

Animal based diets and environment: Perspective from phosphorus flow quantifications of livestock and poultry raising in China.

J Environ Manage 2019 Aug 22;244:199-207. Epub 2019 May 22.

College of Economics and Management, Nanjing Forestry University, Nanjing, 210037, PR China.

Identifying the key nodes of the phosphorus flows in animal raising system is fundamental to improve P utilization efficiency and reduce the P contamination. This study established a phosphorus flow analysis model for livestock and poultry raising, depicted P flows for major livestock and poultry under two raising modes, and further analyzed their spatial and temporal distributions. We find that around 15% of P input was transferred into the products, and in P output around 40% lost into the environment in 2015. The P flows have been increasing since 2000, and the main contributor is pigs followed by beef cattle. It should be noticed that P loss from livestock and poultry raising is huge with extensive prospect of recycling in some central provinces of China, and western region where ecological environment is fragile, has a higher P loss rate which need to change the dietary preference and adjust raising structure. As for diets, pork and eggs are better choices than milk or other kinds of meat in terms of reducing the P load, when producing per unit protein or energy. This study contributes to the understanding of P management in husbandry industry, the quantification of environmental loads of animal-based food and the identification of the potential of reducing P loss to realize sustainable utilization of P.
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http://dx.doi.org/10.1016/j.jenvman.2019.04.028DOI Listing
August 2019

pH-Induced Misfolding Mechanism of Prion Protein: Insights from Microsecond-Accelerated Molecular Dynamics Simulations.

ACS Chem Neurosci 2019 06 22;10(6):2718-2729. Epub 2019 May 22.

School of Pharmacy , Lanzhou University , Lanzhou 730000 , China.

The conformational transition of prion protein (PrP) from a native form PrP to a pathological isoform PrP is the main cause of a number of prion diseases in human and animals. Thus, understanding the molecular basis of conformational transition of PrP will be valuable for unveiling the etiology of PrP-related diseases. Here, to explore the potential misfolding mechanism of PrP under the acidic condition, which is known to promote PrP misfolding and trigger its aggregation, the conventional and accelerated molecular dynamics (MD) simulations combined with the Markov state model (MSM) analysis were performed. The conventional MD simulations reveal that, at an acidic pH, the globular domain of PrP is partially unfolded, particularly for the α2 C-terminus. Structural analysis of the key macrostates obtained by MSM indicates that the α2 C-terminus and the β2-α2 loop may serve as important sites for the pH-induced PrP misfolding. Meanwhile, the α1 may also participate in the pH-induced structural conversion by moving away from the α2-α3 subdomain. Notably, dynamical network analysis of the key metastable states indicates that the protonated H187 weakens the interactions between the α2 C-terminus, α1-β2 loop, and α2-α3 loop, leading these domains, especially the α2 C-terminus, to become unstable and to begin to misfold. Therefore, the α2 C-terminus plays a key role in the PrP misfolding process and serves as a potential site for drug targeting. Overall, our findings can deepen the understanding of the pathogenesis related to PrP and provide useful guidance for the future drug discovery.
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http://dx.doi.org/10.1021/acschemneuro.8b00582DOI Listing
June 2019

Tracing anthropogenic cadmium emissions: From sources to pollution.

Sci Total Environ 2019 Aug 19;676:87-96. Epub 2019 Apr 19.

Geological Survey of Jiangsu Province, Nanjing 210018, PR China.

Cadmium (Cd), a widely concerned heavy metal, is toxic to humans and ecosystems. In this paper, a Cd-polluted town in southeast China was selected to estimate the Cd emissions of human activities into surface water, soil and atmospheric environment. The analysis shows that the total amount of Cd emitted into the environment in 2015 was approximately 43.5 kg, and the majority of those emissions were discharged into the water, accounting for approximately 90.4% of the total Cd emissions. The remaining Cd emissions into the soil and atmosphere accounted for 9.5% and 0.1%, respectively. The industrial production (IP) is the dominant source of anthropogenic Cd emissions, which contributes to 62.1% of the total emissions. The other contributors include aquaculture (AQ), wastewater treatment (WT), living consumption (LC), crop farming (CF) and animal breeding (AB); each accounted for less than 10% of the total emissions. Pigment production is the largest source of IP emissions. According to the results of correlation analysis, the pigment enterprises are responsible for the heavy Cd pollution in local soil. By comparing the spatial position and combing with the local watercourses, the study reveals that the irrigated watercourse is the transmission channels of soil Cd pollution. This study contributes to the analysis of connecting the emission inventory, environmental media and transmission channels of the heavy metal Cd and provides policy supports for the local governments to adopt a life cycle Cd management approach.
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http://dx.doi.org/10.1016/j.scitotenv.2019.04.250DOI Listing
August 2019

Fe-Mn-Ce oxide-modified biochar composites as efficient adsorbents for removing As(III) from water: adsorption performance and mechanisms.

Environ Sci Pollut Res Int 2019 Jun 24;26(17):17373-17382. Epub 2019 Apr 24.

Agro-Environmental Protection Institute, Ministry of Agriculture and Rural Affairs, Tianjin, 300191, China.

In this study, a novel Fe-Mn-Ce oxide-modified biochar composite (FMCBC) was synthesized via pyrolysis to enhance the adsorption capacity of biochar (BC). Scanning electron microscopy-energy-dispersive X-ray spectroscopy confirmed that Fe, Mn, and Ce were successfully loaded onto the surface of the BC. A series of adsorption experiments showed that the FMCBC exhibited improved adsorption of As(III) in an aqueous environment. The adsorption process was well expressed by the pseudo-second-order kinetic model. The adsorption capacity of FMCBC reached 8.74 mg L, which was 3.27 times greater than that of BC. The pH of the solution significantly influenced the adsorption of As(III), where the amount of As(III) adsorbed by FMCBC was maximized at pH 3. A high phosphate concentration inhibited adsorption, whereas nitrate and sulfate ions promoted As(III) adsorption and increased the FMCBC adsorption capacity. Similarly, with increasing humic acid concentration, the adsorption capacity of FMCBC for As(III) decreased; however, a low concentration of humic acid promoted adsorption. X-ray photoelectron spectroscopy analysis revealed that the adsorption of As(III) by FMCBC occurred through redox and surface complexation reactions. Therefore, FMCBC has excellent potential for purifying arsenic-contaminated water.
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http://dx.doi.org/10.1007/s11356-019-04914-8DOI Listing
June 2019