Single-cell sequencing identifies inflammation-promoting fibroblast-neutrophil interaction in peri-implantitis.

AIM: To reveal the cellular composition and molecular environment of the periodontal and peri-implant inflammatory infiltrates through a single-cell sequencing technique, which may explain the pathological difference between these two diseases. A special focus was placed on the phenotypes and potential roles of neutrophils and fibroblasts in peri-implant/periodontal tissue immunity. MATERIALS AND METHODS: High-throughput single-cell transcriptomic profiling of peri-implant tissues from patients with peri-implantitis as well as periodontal tissues from patients with periodontitis and healthy donors was performed. Immunofluorescence analysis was carried out to further validate the identified cell subtypes and their involvement in peri-implantitis and periodontitis. RESULTS: Based on our single-cell resolution analysis, a quantified proportional increase of neutrophil (Neu) subtypes was shown in peri-implantitis. Among these, a predominance of Neutro_CXCR2 was revealed. We also found the involvement of inflammation-promoting fibroblasts as well as a predominance of CXCL8+ fibroblast-CXCR2+ neutrophil interaction in peri-implantitis. CONCLUSIONS: Our study indicated that the predominance of CXCL8+ fibroblast-CXCR2+ neutrophil interaction might underline the enhanced host response in peri-implantitis compared with periodontitis. This information offers a molecular basis by which fibroblast and neutrophil subtypes might be diagnostically and therapeutically targeted in peri-implantitis.

[Characteristics of Cadmium Concentration and Transport of Pueraria thornsonii in Farmland with Different Cadmium Pollution Degrees].

This study aimed to elucidate the cadmium (Cd) concentration and transport characteristics of Pueraria thornsonii in farmland with different Cd pollution degrees, so as to provide a reference basis for phytoremediation of Cd-contaminated farmland. The multi-point experiments in farmland with different Cd pollution degrees[ω(Cd) 0.32-38.08 mg·kg-1] were conducted, and the biomass (dry weight), Cd content, accumulation, concentration, and transport of Cd in P. thornsonii tissues under the main growing period were assessed. According to the results, for P. thornsonii, the tuber dry weight ranged from 5.04 to 11.98 t·hm-2, biomass ranged from 13.21 to 29.07 t·hm-2, and Cd accumulation ranged from 15.74 to 106.03 g·hm-2in the study area. The pattern of Cd uptake by P. thornsonii showed that the main vine>leaf>lateral branches>basal part of sti>tuber. The Cd content in P. thornsonii tissues considerably increased with soil Cd content (P<0.05), whereas the biomass decreased significantly (P<0.05). The Cd concentration and transport factor of aboveground parts in P. thornsonii showed a trend of initially falling, then increasing and decreasing again, whereas the Cd enrichment and transport coefficient of tubers gradually decreased. Correlation analysis revealed that the amount of Cd in the soil was a major predictor of Cd accumulation in P. thornsonii. Under light to moderate Cd contamination, the commercial portion of P. thornsonii (arrowroot)[ω(Cd) 0.03-0.22 mg·kg-1] was less than the standard limit for medicinal plants (≤ 0.30 mg·kg-1). In P. thornsonii from moderately contaminated areas, the Cd concentration and transport factor of aboveground parts were 2.43-7.97 and 3.02-9.81, respectively. This indicates that P. thornsonii is a prospective plant ideal for remediating Cd-contaminated soil because of its high capacity to transfer and enrich Cd.

Effects of electroacupuncture on rats with cognitive impairment: An iTRAQ-based proteomics analysis.

OBJECTIVE: The study explores the effects of electroacupuncture (EA) at the governing vessel (GV) on proteomic changes in the hippocampus of rats with cognitive impairment. METHODS: Healthy male rats were randomly divided into 3 groups: sham, model and EA. Cognitive impairment was induced by left middle cerebral artery occlusion in the model and EA groups. Rats in the EA group were treated with EA at Shenting (GV24) and Baihui (GV20) for 7 d. Neurological deficit was scored using the Longa scale, the learning and memory ability was detected using the Morris water maze (MWM) test, and the proteomic profiling in the hippocampus was analyzed using protein-labeling technology based on the isobaric tag for relative and absolute quantitation (iTRAQ). The Western blot (WB) analysis was used to detect the proteins and validate the results of iTRAQ. RESULTS: Compared with the model group, the neurological deficit score was significantly reduced, and the escape latency in the MWM test was significantly shortened, while the number of platform crossings increased in the EA group. A total of 2872 proteins were identified by iTRAQ. Differentially expressed proteins (DEPs) were identified between different groups: 92 proteins were upregulated and 103 were downregulated in the model group compared with the sham group, while 142 proteins were upregulated and 126 were downregulated in the EA group compared with the model group. Most of the DEPs were involved in oxidative phosphorylation, glycolipid metabolism and synaptic transmission. Furthermore, we also verified 4 DEPs using WB technology. Although the WB results were not exactly the same as the iTRAQ results, the expression trends of the DEPs were consistent. The upregulation of heat-shock protein ß1 (Hspb1) was the highest in the EA group compared to the model group. CONCLUSION: EA can effect proteomic changes in the hippocampus of rats with cognitive impairment. Hspb1 may be involved in the molecular mechanism by which acupuncture improves cognitive impairment.

Single-Cell RNA Sequencing Identifies New Inflammation-Promoting Cell Subsets in Asian Patients With Chronic Periodontitis.

Periodontitis is a highly prevalent chronic inflammatory disease leading to periodontal tissue breakdown and subsequent tooth loss, in which excessive host immune response accounts for most of the tissue damage and disease progression. Despite of the imperative need to develop host modulation therapy, the inflammatory responses and cell population dynamics which are finely tuned by the pathological microenvironment in periodontitis remained unclear. To investigate the local microenvironment of the inflammatory response in periodontitis, 10 periodontitis patients and 10 healthy volunteers were involved in this study. Single-cell transcriptomic profilings of gingival tissues from two patients and two healthy donors were performed. Histology, immunohistochemistry, and flow cytometry analysis were performed to further validate the identified cell subtypes and their involvement in periodontitis. Based on our single-cell resolution analysis, we identified HLA-DR-expressing endothelial cells and CXCL13+ fibroblasts which are highly associated with immune regulation. We also revealed the involvement of the proinflammatory NLRP3+ macrophages in periodontitis. We further showed the increased cell-cell communication between macrophage and T/B cells in the inflammatory periodontal tissues. Our data generated an intriguing catalog of cell types and interaction networks in the human gingiva and identified new inflammation-promoting cell subtypes involved in chronic periodontitis, which will be helpful in advancing host modulation therapy.

[Effect of Organic Matter Promotion on Nitrogen-Cycling Genes and Functional Microorganisms in Acidic Red Soils].

The application of exogenous organic matter is considered the main method of increasing the organic matter content of acidic red soils. Nitrogen is an important limiting factor for soil fertility. Changes to the soil ecosystem under organic matter promotion can affect soil nitrogen cycling and related functional microorganisms; however, there have been no studies on this aspect. Acidic upland red soils, with or without long-term organic fertilizer application, were chosen as the research materials in this study. Based on metagenomic sequencing and alignment in the nitrogen-cycling gene database, the present study aimed to investigate the effect of organic matter promotion on nitrogen-cycling genes and functional microorganisms in acidic red soils, which had been amended with exogenous organic matter for 32 years. The results showed that organic matter promotion in acidic soils increased the total organic carbon and total nitrogen content, and alleviated soil acidification. Organic matter promotion increased the soil net nitrification activity and potential for ammoxidation. Organic matter promotion increased the abundance of amoA genes (encoding ammonia monooxygenase) and nar, nap, nir, nor, and nos genes (encoding denitrification reductase); decreased the abundance of hao genes (encoding hydroxylamine oxidase) and nrf genes related to the dissimilatory nitrate reduction to ammonia; increased the abundance of glnA, gdh, glsA, ansB, and nao genes related to organic nitrogen metabolism; altered the abundance of functional genes related to assimilatory nitrate reduction; and changed the community composition of nitrogen-cycling microorganisms. After organic matter promotion, alleviation of soil acidification and enhancement of total organic carbon were the most important factors that affected the abundance of nitrogen-cycling genes and the community composition of functional microorganisms. Our results comprehensively investigated the inorganic and organic nitrogen-cycling genes, and correlated the functional genes, microbial populations, and functional activities in the ammonia oxidizing process, which provided supporting data to understand the nitrogen-cycling characteristics of acidic red soils and provided ideas for acidic soil improvement.

[Remediation of Cadmium Contaminated Paddy Fields Using Soil Conditioners].

Four soil conditioners, SAMMNS, CCT01, Mineral, and Tebeigai were selected for this study. The effects of the four conditioners on soil pH, bulk density, organic matter, available nutrients, texture, microaggregates, Cd available in soil, and Cd content in brown rice were investigated using field-controlled cadmium tests conducted in cadmium-contaminated paddy fields in Pingxiang. The results showed that compared to the control, soil conditioners could increase pH, bulk density, and cation exchange capacity in soil. SAMMNS and CCT01 soil conditioners increased the amount of silt and clay, but that of sand decreased, whereas the Mineral and Tebeigai soil conditioners decreased silt and clay, and sand increased. In addition to the CCT01 soil conditioner, the application of soil conditioners increased large-scale agglomerates and reduced small-scale microaggregates. The effects of soil conditioners on soil physical and chemical properties promoted the conversion of Cd from contaminated soil from high activity to low activity, which reduced available Cd content in soil (5.21%-34.78%) and Cd content in brown rice (51.39%-68.06%). Correlation analysis showed that Cd content in brown rice was significantly positively correlated with available Cd and available phosphorus in soil, whereas it was negatively correlated with pH and bulk density in soil. Considering the effects of soil and brown rice on cadmium reduction and physicochemical properties, Tebeigai soil conditioner exhibited the best repair effects, followed by SENMES and Mineral soil conditioner.

[Involvement of hippocampal miR-664-3p in electroacupuncture induced improvement of learning-memory ability of cerebral ischemia-reperfusion rats].

OBJECTIVE: To explore the effect of electroacupuncture (EA) on learning-memory ability and its correlation with miR-664-3p levels in the hippocampus in cerebral ischemia-reperfusion injury (CI/RI) rats. METHODS: A total of 27 male SD rats were randomly divided into sham operation, CI/RI model and EA groups (n＝9 in each group). The CI/RI model was established by occlusion of the middle cerebral artery (MACO) according to the modified Longa methods. EA was applied to "Baihui" (GV20) and "Shenting" (GV24) for 20 min, once a day for 7 days. The Morris water maze tests (place navigation tasks and spatial probe trials) were used to evaluate the rats' learning-memory ability. After EA intervention, the hippocampal tissue was collected to measure the mRNA and miRNA expression profiles by using high-throughput next generation sequencing. Bioinformatics analyses including Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses were performed to screen the most abundant differentially-expressed miRNAs and mRNAs, particularly the target genes of miR-664-3p. Their biological functional categories including the key biochemical metabolic pathways and signaling pathways involved in CI and EA effect in the left hippocampus tissue were analyzed. RESULTS: The average escape latency of place navigation tests was significantly longer in the CI/RI model group than in the sham operation group (P<0.01), and obviously shorter in the EA group than in the model group (P<0.01); and the times of escape-platform quadrant crossing of the spatial probe trials were considerably fewer in the CI/RI model group than in the sham operation group (P<0.05), and markedly more in the CI/RI EA group than in the model group (P<0.05). Combined analysis of miRNA and mRNA showed that the differentially-expressed target genes of miR-664-3p were significantly up-regulated after CI/RI relevant to the sham operation rats (P<0.05) and notably down-regulated in the EA group relevant to the CI/RI model group (P<0.05). The GO analysis displayed that the target genes of miR-664-3p were significantly enriched in the category of cell transportation activity, ion binding，and transmembrane transporter activity, the production of precursor metabolites and energy, transportation, signal transduction，localization, etc. KEGG analysis showed that the target genes of miR-664-3p in this study were mainly enriched in the thyroid hormone pathway, Hippo signaling pathway, MAPK signal transduction pathway，cAMP signaling pathway, neurotrophic factor signal transduction pathway, etc. CONCLUSION: EA of GV20 and GV24 can improve the learning-memory ability of CI/RI rats, which is closely related to its effect in down-regulating the levels of hippocampal target genes of miR-664-3p involving cellular transmembrane transportation，cell to environment interaction，cell-cell communication, etc.

[Analysis on the specificity of the relevant points along the governor vessel in chronic gastritis based on tenderness reaction and tenderness threshold].

OBJECTIVE: To explore the specificity of the relevant points along the governor vessel in chronic gastritis through the synchronous observation of the tenderness reaction and tenderness threshold on the back along the governor vessel in the volunteers with chronic gastritis and make the comparison with healthy volunteers. METHODS: A chronic gastritis group and a healthy volunteer group were prepared, 30 cases in each one. Using synchronous comparison, the tenderness reaction at the point inferior to each of the spinous processes from T1 to L3 along the governor vessel was observed. The mechanical pressure pain threshold was determined. RESULTS: Regarding the tenderness reaction at the point inferior to each spinous process on the back along the governor vessel, the occurrence rate was different significantly between the chronic gastritis group and the healthy volunteer group (P<0.01). The tenderness threshold at the point inferior to each spinous process from T1 to L3 along the governor vessel in the chronic gastritis group was lower than the healthy volunteer group, the tenderness thresholds from T4 to T9 and T12 were different significantly between the two groups (P<0.01, P<0.05). The tenderness reaction at the point inferior to each spinous process on the back along the governor vessel presented the significant negative correlation with the tenderness threshold in the chronic gastritis group (P<0.01), and the correlation was not displayed in the healthy volunteer group (P>0.05). CONCLUSION: The point inferior to the spoinous process of T4 on the governor vessel, Shendao (GV 11, T5) and Lingtai (GV 10, T6) are the points with the high specificity in chronic gastritis, which provides the reference to clinical treatment with acupuncture and moxibustion. The occurrence rate of high tenderness reaction and the low tenderness threshold may be the important manifestation of the point specificity on the back along the governor vessel in chronic gastritis.

[Accumulation of Heavy Metals in Different Rice Varieties].

Field experiments were conducted on the heavy metal contents (Cd, Pb, Cr, inorganic As, and total Hg) of the 129 main cultivated rice varieties in southern China. We analyzed the effects of different varieties and types of rice on the absorption capacities of these heavy metals. The results showed that the Cd content in 35 brown rice of early rice was 0.35-0.60 mg·kg-1, exceeding the standard rate of 100%. The Pb content in brown rice was 0.08-0.30 mg·kg-1, exceeding the rate of 14.29%. The Cd content in 54 brown rice of medium rice was 0.03-0.45 mg·kg-1, exceeding the rate of 33.33%. The Cd content in 40 brown rice of late rice was 0.08-0.20 mg·kg-1, which did not exceed the national standard. Early, middle, and late rice all showed that the Cd content of three-line hybrid rice was higher than that of two-line hybrid rice, but the difference was not obvious. The contents of Cr and total Hg in brown rice of three-line hybrid rice in early rice were significantly higher than that of two-line hybrid rice. There was a significant positive correlation between Cd content in brown rice and Pb and total Hg content in medium rice, and there was a significant negative correlation between inorganic Cd content and inorganic As content, whereas there was no significant correlation between Cd and Cr content. In short, rice's absorption and accumulation of heavy metals is greatly affected by genetic background, species types, and heavy metal interactions.

[Nitrification Activity and Autotrophic Nitrifiers in Long-term Fertilized Acidic Upland Soils].

Soil microcosm incubation, molecular ecology techniques including denaturing gradient gel electrophoresis and Illumina MiSeq high-throughput sequencing, and bioinformatics analysis were carried out to investigate the effect of long-term fertilization with chemical fertilizers (NPK) and organic manure (OM) on soil nitrification activity and the autotrophic nitrifying communities in acidic upland soils. No fertilization soil (CK) was the control. Relationships between soil nitrification activities, autotrophic nitrifying communities, and soil characteristics were further evaluated. Long-term fertilization significantly increased the soil organic carbon and inorganic nitrogen contents. Fertilization with organic manure significantly increased soil pH and total nitrogen contents, but decreased soil C/N. Autotrophic nitrification dominated soil nitrification, and accounted for 73.60%-85.32% of total nitrification. Fertilization significantly increased soil autotrophic nitrification activity and the highest value was observed in the OM soil. During the microcosm incubation, the absolute abundances of amoA genes and the relative abundances of 16S rRNA genes of ammonia-oxidizing archaea (AOA) and ammonia-oxidizing bacteria (AOB) in the OM soil significantly increased. The relative abundances of 16S rRNA genes of the AOA greatly increased in both CK and NPK soils. These results suggested the remarkable activity of AOA in the three soils (the predominant population was Nitrososphaera,>99.30%) and implied that AOB was active in the OM soil (the predominant population was Nitrosospira,>99.99%). We also found the activity of nitrite-oxidizing bacteria (NOB) in the OM soil, and the predominant population was Nitrospira (>96.69%). Stepwise regression analysis demonstrated that soil autotrophic nitrification activity was significantly affected by soil total nitrogen content, whereas the abundances of archaeal and bacterial amoA genes were significantly affected by soil organic carbon content and soil pH, respectively. We also found significant positive correlation between the relative abundance of Nitrososphaera and soil nitrate content and a negative correlation between the relative abundance of Nitrosospira and Nitrospira with soil C/N. Overall, our results showed that long-term fertilization greatly increased soil nitrification activity and altered the autotrophic nitrifying communities in acidic upland soils. Soil autotrophic nitrification activity was significantly stimulated by soil total nitrogen content. The Nitrososphaera group played a critical role in nitrification of acidic upland soils. The increased soil pH and decreased soil C/N stimulated the growth of Nitrosospira.

[Influences of biochar and nitrogen fertilizer on soil nematode assemblage of upland red soil].

The use of biochar as soil remediation amendment has received more and more concerns, but little attention has been paid to its effect on soil fauna. Based on the field experiment in an upland red soil, we studied the influences of different application rates of biochar (0, 10, 20, 30, 40 t · hm⁻²) and nitrogen fertilizer (60, 90, 120 kg N · hm⁻²) on soil basic properties and nematode assemblages during drought and wet periods. Our results showed that the biochar amendment significantly affect soil moisture and pH regardless of drought or wet period. With the increasing of biochar application, soil pH significantly increased, while soil moisture increased first and then decreased. Soil microbial properties (microbial biomass C, microbial biomass N, microbial biomass C/N, basal respiration) were also significantly affected by the application of biochar and N fertilizer. Low doses of biochar could stimulate the microbial activity, while high doses depressed microbial activity. For example, averaged across different N application rates, biochar amendment at less than 30 t · hm⁻² could increase microbial activity in the drought and wet periods. Besides, the effects of biochar also depended on wet or drought period. When the biochar application rate higher than 30 t · hm⁻², the microbial biomass C was significantly higher in the drought period than the control, but no differences were observed in the wet period. On the contrary, microbial biomass N showed a reverse pattern. Dissolved organic matter and mineral N were affected by biochar and N fertilizer significantly in the drought period, however, in the wet period they were only affected by N fertilizer rather than biochar. There was significant interaction between biochar and N fertilizer on soil nematode abundance and nematode trophic composition independent of sampling period. Combined high doses of both biochar and N fertilization promoted soil nematode abundance. Moreover, the biochar amendment increased the proportion of fungivores especially in the drought period, suggesting the biochar was the preferred fungal energy channel in comparison to soil without biochar addition. In summary, complex patterns occurred not only due to the application rate of biochar as well as their interactions with N fertilization but also due to the drought and wet periods. It is, therefore, necessary to consider different ecological factors when evaluating the effects of biochar in future.

[Influence of acupuncture of "Changqiang" (GV 1) on learning-memory ability and gap junction-related protein expression in the prefrontal cortex in autism rats].

OBJECTIVE: To observe the effect of acupuncture stimulation of "Changqiang" (GV 1) on learning-memory ability and gap junction-related protein expression in the prefrontal cortex in autism rats. METHODS: Forty Wistar rats were equally randomized into control, model, GV 1 and non-acupoint groups. For establishing autism model, Valproate acid (VPA) sodium (600 mg/kg) was given (i. p.) to pregnancy rats whose intimate filial generation was confirmed to be successful autism by eye-open tests, swimming test and Morris water maze swimming tasks. GV 1 or non-acupoint (the spot below the costal region, i.e., 2 cm superior to the posterior superior iliac spine and about 3 cm lateral to the spine) was punctured and stimulated for about 1 min by using a filiform needle, once daily for 30 days except the weekends. The rats' learning-memory ability was detected by Morris water maze tasks. The expression of gap junction-related proteins connexin 43 (CX 43), CX 32 and CX 36 in the frontal cortex tissue was detected by immunohistochemistry. RESULTS: After modeling, the postnatal rats' eye-open time on day 14, 15 and 16 was significantly later (P < 0.05); and the swimming ability on postnatal day 13 and 15 was obviously lower in comparison with that of the control group (P < 0.05). After acupuncture treatment, the increased escape latency and the decreased swimming velocity of the autism rats were obviously suppressed in the GV 1 group, rather than in the non-acupoint group (P < 0.05). It suggests an improvement of learning-memory ability after acupuncture stimulation of GV 1. In comparison with the control group, the expression levels of cerebral CX 43, CX 32 and CX 36 proteins (mean grey values) were considerably down-regulated in the model group (P < 0.05). While compared to the model group, their expression levels were apparently up-regulated in the GV 1 group (P < 0.05) but not in the non-acupoint group. CONCLUSION: Acupuncture intervention of GV 1 can improve the learning- memory ability in autism rats, which may be closely related to its effects in up-regulating expression levels of CX 43, CX 32 and CX 36 in the frontal cortex.

[Hydrogen sulfide removal by the combination of non-thermal plasma and biological process].

A bench scale system integrating a non-thermal plasma (NTP) unit with a biotricking filtration (BTF) unit for the treatment of gases containing hydrogen sulfide (H2S) was investigated. The additional use of the biotrickling filter to NTP reactor not only leads to the enhancement of hydrogen sulfide removal efficiency up from 83.4% to 90.1%, but also eliminates gas-phase intermediate products from NTP degradation of H2S to produce sulfate and H2O. The dynamic changes of microbial community in BTF influenced by ozone from NTP were assessed by PCR-DGGE. Results show that the microbial community was affected by ozone. After the integration, a part of microorganisms disappeared, and meanwhile some new microorganisms appeared. The microbial community structure in BTF changed from eight bands to nine bands; three bands which have the functions of desulfurization disappeared and four bands which have the functions of desulfurization appeared; five bands which have the functions of desulfurization and sulfate reduction were unchanged. The bacterial groups in the BTF unit of NTP-BTF system include Uncultured Thiobacillus sp., Acidithiobacillus thiooxidans strain dfI, Uncultured Thiobacillus sp., Uncultured Acidiphilium sp., Uncultured Xanthomonadaceae bacterium clone SBLE6C12, Uncultured 8-Proteobacterium and Paracraurococcus sp. 1PNM-27.

[Gaseous phenol removal in a bio-trickling filter].

The performance of a bio-trickling filter (BTF) for treatment of phenol, a model pollutant, was presented. Influences of factors on phenol removal efficiency were studied. The BTF exhibited a high removal efficiency for phenol. The experimental results showed that the phenol efficiency reached 99.5% and kept 98% in the long-term run. The optimal residence time, pH value and spray density were 20.6 s, 7.0 and 1.67 m(3) x (m(2) x h)(-1), respectively. The microbial community structures in the bio-trickling filter for phenol removal were assessed by PCR-DGGE. Based on the 16S rDNA sequence data,results showed that the predominant bacteria for degradation of phenol were Polaromonas sp., Acinetobacter sp., Acidovorax sp., Veillonella parvula and Corynebacterium sp., GC-MS was used to detect component of BTF's outlet gases and pyruvic acid (CH3COCOOH) was found as one kind of intermediates of phenol degradation. Then one possible biodegradation pathway of phenol was inferred.

[Effects of biochar application on the vertical transport of NO(3-)-N in the red soil and its simulation].

Soil column experiments in laboratory were conducted to determine the effect of biochar application on the vertical transport of NO(3-)-N in red soil. Biochar was mixed thoroughly with soil at rates of 0, 5, 10, 20, 30 and 40 t · hm(-2), i. e., biochar/soil ratios of 0, 2.22%, 4.459%, 8.95%, 13.37% and 17.80%. The CXTFIT 2.0 model was used to simulate the breakthrough curve of NO(3-)-N. The results were as follows: the breakthrough curve of NO(3-)-N varied remarkably with the increase of biochar application rate under saturated condition. The peak values of relative concentration (C/Co) , leaching rate and cumulative loss of NO(3-)-N all significantly decreased with the increasing biochar application rate. There existed a certain prolongation of the breakthrough curves among all treatments. The more the biochar was applied, the more obviously the break-through curve was prolonged. According to the correlation analysis between the NO(3-)-N break-through curves and soil properties, biochar affected the bulk density, organic carbon, total porosity, CEC of red soil, which would exert an effect on the breakthrough curves. The simulation value and the actual obtained value of the breakthrough curves were positively correlated with the correlation coefficients being over 0. 850 in all breakthrough curves, which indicated the CXTFIT 2.0 model could best fit the prediction of nitrate-N transport and relative infiltration. These results could provide a scientific basis for predicting the effect of biochar on nitrate-N in underground water after biochar incorporation into field.

[Mechanism and performance of styrene oxidation by O3/H2O2].

It can produce a large number of free radicals in O3/H2O2, system, ozone and free radical coupling oxidation can improve the styrene removal efficiency. Styrene oxidation by O3/H2O2 was investigated. Ozone dosage, residence time, H2o2 volume fraction, spray density and molar ratio of O3/C8H8 on styrene removal were evaluated. The experimental results showed that styrene removal efficiency achieved 85.7%. The optimal residence time, H2O2, volume fraction, spray density and O3/C8H8 molar ratio were 20. 6 s, 10% , 1.72 m3.(m2.h)-1 and 0.46, respectively. The gas-phase degradation intermediate products were benzaldehyde(C6H5CHO) and benzoic acid (C6H5 COOH) , which were identified by means of gas chromatography-mass spectrometry(GC-MS). The degradation mechanism of styrene is presented.

[Effects of combined application of biochar and inorganic fertilizers on the available phosphorus content of upland red soil].

Aiming at the low content of available phosphorus in upland red soil of Southern China, this paper studied the effects of combined application of biochar and inorganic fertilizers on the available phosphorus and organic carbon contents and the pH of this soil. With the combined application of biochar and inorganic fertilizers, the soil physical and chemical properties improved to different degrees. As compared with the control, the soil pH and the soil organic carbon and available phosphorus contents at different growth stages of oil rape after the combined application of biochar and inorganic fertilizers all had an improvement, with the increments at bolting stage, flowering stage, and ripening stage being 16%, 24% and 26%, 23%, 34% and 38%, and 100%, 191% and 317% , respectively. The soil pH and the soil organic carbon and available phosphorus contents were increased with the increasing amount of applied biochar. Under-the application of biochar, the soil available phosphorus had a significant correlation with the soil pH and soil organic carbon content. This study could provide scientific basis to improve the phosphorus deficiency and the physical and chemical properties of upland red soil.