[Effects of Biochar Addition on Soil Nitrogen Mineralization and Leaching Characteristics in Riparian Zone of Taihu Lake].

Nitrogen mineralization in riparian soil changes the migration and utilization efficiency of nitrogen, which is closely related to the control of water eutrophication. The differences in soil properties caused by land use alter nitrogen retention and transport capacity. Therefore, the soil of three land use types (woodland, grassland, and cultivated land) in the western riparian zone of Taihu Lake were selected for research on the dynamic changes in nitrogen mineralization amount using an incubation experiment and a leaching characteristics by soil column leaching experiment, and their environmental effects were also studied under different biochar addition conditions (0%, 1%, and 5%). The results showed that, in general, the addition of biochar inhibited nitrogen mineralization in forest land and grassland soil, whereas the effect of biochar on nitrogen mineralization in cultivated land was promoted in low concentrations but inhibited in high concentrations. Leaching experiments showed that the biochar addition reduced the loss of soil mineral nitrogen, and the reduction rate in ammonia nitrogen was 23.28%-39.79%, whereas there was little difference between the three land use types. The nitrate decreased by 17.20%-44.49%, and the reduction rate of cultivated land was smaller than that of forest land and grassland. In conclusion, the input of biochar into grassland and cultivated land can better maintain soil fertility and reduce soil nitrogen loss in riparian soil.

Gpr19 is a circadian clock-controlled orphan GPCR with a role in modulating free-running period and light resetting capacity of the circadian clock.

Gpr19 encodes an evolutionarily conserved orphan G-protein-coupled receptor (GPCR) with currently no established physiological role in vivo. We characterized Gpr19 expression in the suprachiasmatic nucleus (SCN), the locus of the master circadian clock in the brain, and determined its role in the context of the circadian rhythm regulation. We found that Gpr19 is mainly expressed in the dorsal part of the SCN, with its expression fluctuating in a circadian fashion. A conserved cAMP-responsive element in the Gpr19 promoter was able to produce circadian transcription in the SCN. Gpr19-/- mice exhibited a prolonged circadian period and a delayed initiation of daily locomotor activity. Gpr19 deficiency caused the downregulation of several genes that normally peak during the night, including Bmal1 and Gpr176. In response to light exposure at night, Gpr19-/- mice had a reduced capacity for light-induced phase-delays, but not for phase-advances. This defect was accompanied by reduced response of c-Fos expression in the dorsal region of the SCN, while apparently normal in the ventral area of the SCN, in Gpr19-/- mice. Thus, our data demonstrate that Gpr19 is an SCN-enriched orphan GPCR with a distinct role in circadian regulation and may provide a potential target option for modulating the circadian clock.

[Comparison of Available Nitrogen and Phosphorus Characteristics in the Land-Water Transition Zone of Different Watersheds and Their Environmental Significance].

In order to explore the characteristics and environmental significance of available nitrogen and phosphorus in different land-water transition zones, soil and sediment samples from three study areas, including the upstream watershed of Minjiang River (MJU), western watershed of Hongze Lake (HZW), and western watershed of Taihu Lake (THW), were collected and analyzed. The results showed that the contents of total nitrogen and phosphorus in THW were higher than those of other two study areas. The contents of nitrogen and phosphorus in sediments were higher than those in soils of HZW. The distribution trend of available nitrogen and available phosphorus was generally consistent with the distribution trend of total nitrogen and phosphorus. The proportions of available nitrogen and phosphorus in THW and HZW were much higher than those in MJU, and the proportions of available nitrogen and phosphorus in sediments were higher than those in soils. The physiochemical properties such as pH value, organic matter, and iron and aluminum oxides were related to the available nitrogen and phosphorus in the soil and sediment, but correlations between them were complex. The distribution patterns of available nitrogen and phosphorus in the soil and sediments of the land-water transition zone reflect the impacts of the natural environment and human activities, particularly those of the latter.

[Effects of Biochar Input on Changes of Available Nutrient Elements in Riparian Soils with Different Landuse Types].

Biochar, as a new environmentally friendly material, has been used to improve soil quality and for pollution remediation. Biochar input has a significant impact on available nutrients in the soil. Based on the different land use types (forestland, grassland, cultivated land, and barren land) in the riparian zone of Taihu Lake, the effects of biochar application on the available content of nutrients in different land use types of soil were compared, and the dynamics of nutrient change was also discussed. Results show that the addition of biochar can significantly affect the available nutrient content in riparian soil, however the influential degrees for carbon, nitrogen, and phosphorus were different. After the input of biochar, dissolved organic carbon in riparian soils showed a clear downward trend, while the available nitrogen increased slightly, and the available phosphorus increased significantly. For woodland, grassland, arable land and wasteland soils, the contents of dissolved organic carbon decreased by 33.3%, 27.4%, 29.5%, and 51.4%, while the contents of available nitrogen increased by 10.8%, 18.2%, 16.4%, and 15.2%, and the contents of available phosphorus increased by 40.0%, 50.2%, 34.0%, and 43.6%, respectively. Compared with the concentrations between the control group soil (CK) and the biochar additive group soil (BC), the concentrations of dissolved organic carbon and available phosphorus exhibited large differences between the two groups regarding available nitrogen concentrations. Among the four types of riparian soils, the effects of biochar on the availability of different nutrients were different.

Spatial variations in and environmental significance of nitrogen forms in river sediments from two different watersheds in eastern China.

Nitrogen is considered an essential nutrient element limiting water productivity, and its distribution in sediments directly affects its release potential. This study aimed to analyse the spatial characteristics, distribution, and influence of nitrogen forms in two different river catchments situated in eastern China. Using sequential extraction methods, the study divided sediment nitrogen into four forms, namely, an ion-exchangeable form (IEF-N), weak acid-extractable form (WAEF-N), strong alkali-extractable form (SAEF-N), and strong oxidant-extractable form (SOEF-N). The results for the two catchments showed significant differences in the physicochemical properties as well as variations in space. The mean proportion of total transferable nitrogen (TTN) in the Anhe, Suihe, Dongtiaoxi, and Xitiaoxi rivers accounted for 50.64%, 32.87%, 34.63%, and 40.45%, respectively. The results also revealed a higher total TTN in the Hongze watershed than in the Tiaoxi watershed. The order of mean TTN in sediments from the Hongze watershed was SOEF-N > SAEF-N > IEF-N > WAEF-N, whereas that for the Tiaoxi watershed was SOEF-N > SAEF-N > WAEF-N > IEF-N. The distribution of nitrogen forms in the sediments was significantly impacted by the sediment composition and environmental factors, as shown by correlation and redundancy analysis (RDA).

Spatial distribution, source analysis, and ecological risk assessment of PBDEs in river sediment around Taihu Lake, China.

The distribution and composition of organic pollutants in sediment are affected by the source and regional environment. To understand the characteristics and risk of polybrominated diphenyl ethers (PBDEs) in the area around Taihu Lake, composite sediment samples (n = 41) were collected in rivers around Taihu Lake to explore the level, spatial distribution, and source of PBDEs. The results showed that the most abundant BDE congener in river sediment was BDE209, followed by BDE99 and BDE47, with median values of 48.7, 2.17, and 1.52 ng g-1, respectively. Concentrations of PBDEs in sediments from northern rivers were significantly higher than those from other areas, but the overall risk was at a moderate-lower level compared with research results in other references. Results of principle component analysis (PCA) and source characteristics analysis revealed that most of PBDEs in river sediments around Taihu Lake were mixture of multiple sources, which mainly originated from atmospheric deposition, industrial wastewater, and municipal sewage. TOC showed good correlations with most PBDEs, which implied that PBDE components were influenced by sediment organic matter. Meanwhile, the risk of PBDEs in river sediments in this study area is a moderate-lower level.

Prevalence of fluoroquinolone, macrolide and sulfonamide-related resistance genes in landfills from East China, mainly driven by MGEs.

Landfills are one of the most important reservoirs of antibiotic resistance genes (ARGs), and ARG pollution in landfills has been well investigated. However, the various factors contributing to the widespread prevalence of ARGs in landfills have rarely been explored. Here, we quantified three classes of antibiotics, six kinds of heavy metals, eight types of ARGs, and five varieties of mobile genetic elements (MGEs) in refuse samples from 10 landfills in Zhejiang Province, China. Compared with sulfonamides and macrolides, fluoroquinolones were present at much higher concentrations in all refuse samples, reaching a concentration of 1406.85 µg/kg in the Jiaxing region. The relative abundances of qnrD, qnrS, mexF, ermA, ermB, mefA, sul1, and sul2 in most landfills were >10-4 copies per 16S rRNA, suggesting the presence of highly contaminated ARGs. No significant correlations between most target antibiotics and their corresponding ARGs were found. Variation partitioning analysis indicated that MGEs could be the determining factor in the spread of ARGs in landfills. This research not only reveals high levels of ARGs and the ubiquitous presence of antibiotics in refuse, but also provides guidance for controlling the spread of ARGs in landfills.

Aeromonas hydrophila, an Emerging Causative Agent of Freshwater-Farmed Whiteleg shrimp Litopenaeus vannamei.

Aeromonas hydrophila is a well-known bacterial pathogen associated with mass mortalities in aquaculture. Yet, few reports are available on whiteleg shrimp-pathogenic A. hydrophila. In the present study, a virulent isolate WS05 was confirmed as a causative agent of diseased freshwater-cultured whiteleg shrimp and showed a mean lethal dose (LD50) value of 4.8 × 104 CFU mL-1. It was identified phenotypically and molecularly as an A. hydrophila strain, and exhibited susceptibility to several veterinary antibiotics extensively used in aquaculture, including cotrimoxazole, doxycycline, florfenicol, neomycin, and tetracycline. In view of the strongest inhibition zone of florfenicol against isolate WS05, the synergistic effect of the combinations of florfenicol and herb extracts was further evaluated, and the result indicated that Punica granatum extract was a potential synergist of florfenicol against isolate WS05 and the fractional inhibitory concentration index (FICI) for the florfenicol-P. granatum extract was calculated as 0.31. When combined with 7.81 mg mL-1 P. granatum extract, the minimum inhibitory concentration (MIC) of florfenicol against isolate WS05 was reduced from 0.50 to 0.03 mg L-1, and its activity against isolate WS05 was also enhanced with a significant reduction of ≥3.61 log in cell density after 24 h of treatment compared with that in the single drug treatment. In addition, the protective effect was potentiated by the combination of florfenicol and P. granatum extract, with a cumulative mortality of 36.66% (p < 0.05) and 33.33% (p < 0.05) lower than that in the single treatment with florfenicol and P. granatum extract after the challenge with isolate WS05 for seven days. As far as we know, this is the first study to describe whiteleg shrimp-pathogenic A. hydrophila and suggest P. granatum extract as a potential synergist of florfenicol against the A. hydrophila pathogen.

[Spatial Distribution of Organic Phosphorus in Sediment and Its Environmental Implication in the Upper Stream of Minjiang River].

In order to explore the effect of land use pattern on phosphorus distribution and the potential release capacity of stream sediment in the upper Minjiang River, this paper presented organic phosphorus forms and their spatial distribution characteristics of sediments in the upper Minjiang River by using the IVANOFF method and discussing the effects of physicochemical properties of sediments on the distribution of organic phosphorus forms. The results show that:①nitrogen and phosphorus contents of sediments in Jianxi and Shaxi catchments are higher than those in the Futunxi catchment, probably related to the large number of farmland runoff and municipal sewage near the Jianxi and Shaxi catchments and the large forest area around the Futunxi catchment;②contents in the sediments from three catchments and TP contents in the sediments from Jianxi and Futunxi catchments showed the order of upper reaches < middle reaches < lower reaches, which may be caused by the mountainous and forested areas in the upper reaches and the intensive human activities in the middle and lower reaches;③nitrogen phosphorus in sediments of the three catchments were mainly non-active organic phosphorus, which indicated that upper reaches of the Minjiang river were generally less affected by external pollution, and the relative proportion of organic phosphorus in the sediments of different catchments was relatively large, while the change in different sections of the same river was relatively small;④physicochemical properties of sediments had a significant impact on the morphology and distribution of organic phosphorus, among which the effects of organic matter, TP, and TN were the most obvious, but the effects on sediments in different river basins were different. Therefore, to protect the water quality of the upper Minjiang River, it is necessary to strengthen the control of the living and agricultural pollution sources near the catchments.

Association between elevated plasma microRNA-223 content and severity of coronary heart disease.

Bioinformatics indicate that miR-223 regulates many genes associated with cholesterol metabolism, and it could also control high-density lipoprotein-cholesterol (HDL-C) uptake. As reported in previous study, miR-223 was found to be upregulated from human subjects with familial hypercholesterolaemia, however, it remains to be determined using a larger group of coronary heart disease (CHD) patients. Moreover, whether it correlates with severity of atherogenesis, has never been elucidated before. We aim to further explore the association between circulating miR-223 content and severity of CHD. Sample was collected from 300 CHD patients and 100 subjects with angiographic exclusion of CHD. MiR-223 content was detected using quantitative real-time PCR. Gensini score was used to evaluate the severity of coronary stenotic lesions. Expression of miR-223 was identified on basis of the quartiles of the Gensini score, and association between the miRNA and CHD was analyzed. Diagnostic potential of miR-223 of CHD was performed by ROC analysis. CHD patients had higher miR-223 level (13.23, 9.29-17.59 vs. 4.05, 3.06-6.11, p < .001), and the miRNA content significantly elevated following increasing Gensini score (p < .001). Gensini score was significantly associated with miR-223 expression (r= .7289, p < .001). The optimal cut-off value of miR-223 was with a sensitivity of 86.0% and specificity of 91.3%. The AUC of miR-223 was 0.933 (95%CI, 0.905-0.961). These preliminary results suggest that the expression of miR-223 may be associated with atherogenesis. The level of circulating miR-223 in predicting the severity of coronary atherosclerosis may have a relatively certain value.

Preparation of a novel chloromethylated polystyrene-2-mercapto-1,3,4-thiadiazole chelating resin and its adsorption properties and mechanism for separation and recovery of Hg(II) from aqueous solutions.

With an efficient methodology, a novel chloromethylated polystyrene-g-2-mercapto-1,3,4-thiadiazole chelating resin (MTR resin) was prepared via a one-step reaction. The structure of MTR resin was characterized by elements analysis, Fourier transform infrared spectroscopy, thermogravimetric analysis, and scanning electron microscopy. Meanwhile, the adsorption properties of the resin for Hg(II) were investigated by batch and column experiments. The results showed that the resin possessed much better adsorption capability for Hg(II) than for other metal ions. The statically and the dynamic saturated adsorption capacities were 343.8 mg/g and 475.1 mg/g. The adsorption kinetic and equilibrium data were well fitted to the second-order model and the Langmuir isotherm model, respectively. Desorption of mercury from the resin can be achieved using 30 mL of 2 mol/L HCl-5% thiourea solution with a desorption ratio of 92.3%. Compared with other absorbents, MTR resin was greatly conserve natural resources and reduce the cost.

One-Step Reduction and Surface Modification of Graphene Oxide by 3-Hydroxy-2-Naphthoic Acid Hydrazide and Its Polypropylene Nanocomposites.

3-Hydroxy-2-naphthoic acid hydrazide (HNH), a new reductant and modifier, was applied to reduce and modify graphene oxide (GO) in a one-step process. The obtained HNH reduced graphene oxide (HNH-rGO) was characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), Raman spectroscopy, X-ray photoelectron spectroscopic (XPS) and Fourier transform infrared spectra (FTIR). The results demonstrated that GO was successfully reduced to graphene and the surface of HNH-rGO was grafted with HNH. The interlayer space was increased from 0.751 nm to 1.921 nm, and its agglomeration was much more attenuated compared with GO. HNH-rGO/polypropylene and graphene/polypropylene composites were synthesized through melt-blending method. The viscosity was enhanced with increased addition of graphene and surface modified graphene demonstrated stronger rheological behavior improving effect than the untreated graphene.

Atomic structure and polarity compensation of BaTiO3 (1 1 1) surface.

Surfaces of perovskite-type oxides have been attracting increasing interest for their primary importance in various potential applications such as multiferroic thin films, interface electronics and catalysis. However, the (1 1 1) surface of BaTiO3, the most typical ferroelectric, is far from well understood. In this work, the atomic structure and polarity compensation of BaTiO3 (1 1 1) surface have been investigated combining aberration-corrected transmission electron microscopy and first-principle calculations. Depending on the density of oxygen vacancies, the surface shows different degrees of atomic relaxation and electronic charge transfer, which compensates the surface polarity together with the ionic charges associated with the oxygen vacancies. The atomic relaxation and charge transfer would have a direct impact on the ferroelectric and catalytic properties of low-dimensional BaTiO3.

[Degradation of dimethyl phthalate by Ti (IV)-catalyzed O3/H2O2 under acidic conditions].

The degradation efficiencies of dimethyl phthalate (DMP) by O3, O3/H2O2, Ti(IV)/O3 and Ti(IV)/O3/H2O2 were investigated under acidic conditions. The results indicated that Ti(IV)/O3/H2O2 was the best system with the highest degradation efficiency and mineralization rate of DMP, and the highest utilization rate of ozone at pH 2.8. The apparent rate constants of DMP degradation by O3, O3/H2O2, Ti(IV)/O3 and Ti(IV)/O3/H2O2 under the same conditions were 3.96 x 10(-4) s(-1), 9.54 x 10(-4) s(-1) 1.07 x 10(-3) s(-1) and 6.41 x 10(-3) s(-1), respectively. The ozone utilization rate of Ti(IV)/O3/H2O2 was improved by 6.51% compared with that of ozonation alone. The experimental results showed that the optimized concentrations of Ti(IV) and H2O2 were 1.4 mg x L(-1) and 10 mg x L(-1), respectively. According to the results of gas chromatography-mass spectrometry (GC/MS) and ion chromatography analysis, the possible reaction pathway of DMP degradation by Ti(IV)/O3/H2O2 was proposed and discussed.

[Research of urban eutrophic water repair by water/sediment biological bases].

A micro power turbine water aeration system with a water biological base and a sediment biological base was independently developed, aimed at urban water eutrophication. The results showed that the average removal rates of COD, NH+4 -N, TP by the water biological base were 82. 33% , 98. 00% and 54. 73% , respectively; The sediment reduction rate achieved by the sediment biological base could reach 20% within 5 days, and aeration in the overlying water could relieve the nutrient releasing caused by the degradation of organic matter; The effect of nutrient removal and organic matter reduction in sediment by the combined ecological restoration technology was perfect in pilot scale. The average removal rates of COD, NH+4 -N, TP were 52. 0%, 33. 6% and 23.4%, respectively, and the organic content in sediment was reduced from 38. 20% to 12.20% .

Protective effects of andrographolide analogue AL-1 on ROS-induced RIN-mß cell death by inducing ROS generation.

Oxidative stress is considered to be a major factor contributing to pathogenesis and progression of many diseases. A novel andrographolide-lipoic acid conjugate (AL-1) could protect pancreatic ß-cells from reactive oxygen species (ROS)-induced oxidative injury. However, its protective mechanism is still unclear. In this work, we used proteomics to identify AL-1-regulated proteins in ß-cells and found that 13 of the 71 proteins regulated by AL-1 were closely associated with antioxidation. These differential proteins were mainly involved in the ERK1/2 and AKT1 signaling pathways. Functional investigation demonstrated that AL-1 exerted its protective effects on H2O2-induced cell death of ß-cells by generating NADPH oxidase-dependent ROS to activate ERK1/2 and AKT1 signaling pathways. As a consequence, the expressions of antioxidant proteins including Trx1, Prx1 and Prx5, and anti-apoptotic proteins including PDCD6IP, prohibitin, galectin-1 and HSP were upregulated. AL-1 probably worked as a "vaccinum" to activate the cellular antioxidant system by inducing the generation of low concentration ROS which then reciprocally protected ß-cells from oxidative damage caused by high-level ROS from H2O2. To the best of our knowledge, this is the first comprehensive proteomic analysis illustrating a novel molecular mechanism for the protective effects of antioxidants on ß-cells from H2O2-induced cell death.