Environmental pollution of fluoroquinolones and its relationship with nitrogen cycling mediated by microorganisms.

Fluoroquinolone antibiotics (FQs) are one of the most widely used antibiotics, which are new pollutants with 'pseudo persistence' in the environment, causing great ecological risks. FQs could change the structure and function of microbial communities and affect nitrogen cycling mediated by microorganisms. Consequently, FQs would change the composition of various types of nitrogen in the environment and exert a significant impact on the global nitrogen cycling.

Biogeochemical behavior and ecological environmental effects of fluoroquinolones.

Synthetic fluoroquinolones (FQs) are the third most commonly used antibiotics in the world and play an extremely important role in antibacterial drugs. The excessive use and discharge will alter ecological environment, with consequence on human health and global sustainable development. It is therefore of great significance for scientific use and management of FQs to systematically understand their biogeochemical behavior and eco-environmental effects.

Behavioral and ecotoxicology of sulfonamide metabolites in the aquatic environment.

Sulfonamides (SAs) are the first broad-spectrum synthetic antimicrobial agents used in human health and veterinary medicine. The majority of SAs entering human body is discharged into aquatic environment in the form of parent material or metabolites. The residues of SAs and their metabolites in the aquatic environment and the development of drug resistance can be serious threats to ecosystems and human health.

The effect of fibroblast growth factor 21 on a mouse model of bovine viral diarrhea.

Previously, we researched that bovine viral diarrhea virus (BVDV) induced a very significant increase in fibroblast growth factor 21 (FGF21) expression in mouse liver and that FGF21 was increased in the peripheral blood of BVD cattle and BVD mice. To determine the role of FGF21 in relieving clinical symptoms and inhibiting the intestinal damage caused by BVDV in BVD development in mice, BALB/c mice were intraperitoneally injected with cytopathic biotype (cp) BVDV-LS01 (isolated and identified by our group) to establish a BVD mouse model. The role of FGF21 in the BVD mouse model was investigated by injecting the mice with FGF21.

[Response of Bacteriohopanepolyols to Hypoxic Conditions in the Surface Sediments of the Yangtze Estuary and Its Adjacent Areas].

Bacteriohopanepolyols (BHPs), as a novel bacterial biomarker, show clear potential for tracking organic matter sources and environmental change. To evaluate BHPs as indicators of seasonal hypoxia in the Yangtze Estuary and its adjacent areas, the composition, distribution, and source of BHPs in surface sediments were analyzed using high-performance liquid chromatography-atmospheric pressure chemical ionization-mass spectrometry (HPLC-APCI-MS). A total of 12 BHPs were detected with a normalized TOC concentration of 3.

[Compound-specific carbon and nitrogen isotope analysis of amino sugars and their applications].

Amino sugars (AS) are one of the important biochemical components in the natural organic matter pool. Clarifying the sources and transformations of AS would facilitate our understan-ding of the microbial regulation of organic matter. As an emerging technology, compound-specific isotope analysis of amino sugars (CSIA-AS) provides more detailed dynamic information of indivi-dual AS in natural environment.

Process and mechanism of nitrogen loss in the ocean oxygen minimum zone.

There is a big imbalance between the input and output of oceanic nitrogen in global ocean nitrogen cycles, because a part of the fixed nitrogen is reduced to N or NO and then lost from the ocean. Oxygen minimum zone (OMZ) is the most important area for nitrogen loss, which could lose fixed nitrogen up to 40 to 450 Tg·a through the denitrification and anammox. A summary of the two main roles of nitrogen loss in the different OMZ sea areas reveals that heterotrophic denitrification dominates in eastern tropical Pacific, Arabian Sea, and marine sediments.

[Amino acids in marine particulate matters and sediments and their role as indicators for organic matter degradation.].

As important components of marine organic matters especially of organic nitrogen, amino acids play an important role in organic matter cycles owing to their lability. The concentration, composition, and distribution of amino acids have been widely used to indicate the degradation state of organic matters in particulates and sediments of marine. Here, the distribution, influencing factors of amino acids and their role in indicating degradation of organic matters were systematically summarized.

[Distribution and Sources of -alkanes in Surface Seawater of Jiaozhou Bay].

Hydrocarbons emitted by human activities probably constitute the largest class of contaminants that are present in coastal areas, because of widespread use of fossil fuels for power generation and logistics, and accidental spillages. The chemical composition of hydrocarbon mixtures found in the marine environment allowed the identification of relative contributions of different natural and anthropogenic sources. Identification of these hydrocarbons, especially -alkanes, could act as tracers for the possible sources.

[Atmospheric depositions of biogenic elements and their ecological effects on marine ecosystem of Jiaozhou Bay: A review].

As a typical semi-closed bay, Jiaozhou Bay, is remarkably affected by human activities. Biogenic elements transported into the oceans by the atmospheric deposition of anthropogenic particles can lead to profound impacts on the ecosystem of Jiaozhou Bay. In this paper, the researches of atmospheric dry and wet depositions in the Jiaozhou Bay were systematically summarized from the following three aspects: study methods, variation characteristics of the fluxes and their influencing factors and the ecological effects of atmospheric deposition.

[Distribution and Environmental Significances of Radionuclides in the Sediment of the Changyi Coastal Wetland].

The radionuclides contents in the surface sediments and sediment cores were determined by gamma spectrometry method. The distribution of radionuclides and its indication to material sources, human activities and other sedimentary environmental evolution events were discussed and the sedimentation rate was estimated. The results showed that the average activity concentrations of U,Th, Ra andK in the surface sediment were (54.

[Release and supplement of carbon, nitrogen and phosphorus from jellyfish (Nemopilema nomurai) decomposition in seawater].

Abstract: Jellyfish bloom has been increasing in Chinese seas and decomposition after jellyfish bloom has great influences on marine ecological environment. We conducted the incubation of Nemopilema nomurai decomposing to evaluate its effect on carbon, nitrogen and phosphorus recycling of water column by simulated experiments. The results showed that the processes of jellyfish decomposing represented a fast release of biogenic elements, and the release of carbon, nitrogen and phosphorus reached the maximum at the beginning of jellyfish decomposing.

Spatial variation, fractionation and sedimentary records of mercury in the East China Sea.

Surface and core sediments were collected to study distributions, phases and potential environmental risk of Hg and to reconstruct anthropogenic Hg change over the past one hundred years in the East China Sea (ECS). Hg contents in surface sediments displayed a decreasing gradient from the Changjiang Estuary to the outer sea. Sequential extraction analysis showed that Hg mainly existed as residual fraction (70.

Jellyfish (Cyanea nozakii) decomposition and its potential influence on marine environments studied via simulation experiments.

A growing body of evidence suggests that the jellyfish population in Chinese seas is increasing, and decomposition of jellyfish strongly influences the marine ecosystem. This study investigated the change in water quality during Cyanea nozakii decomposition using simulation experiments. The results demonstrated that the amount of dissolved nutrients released by jellyfish was greater than the amount of particulate nutrients.

[Causes of jellyfish blooms and their influence on marine environment].

Jellyfish blooms have damaged the normal composition and function of marine ecosystem and ecological environments, which have been one of the new marine ecological disasters. In this study, we summarized the possible inducements of jellyfish blooms, and the influences of jellyfish blooms on biogenic elements, dissolved oxygen, seawater acidity and biological community were discussed emphatically. The results showed that jellyfish blooms had a close contact with its physiological structure and life history, which had favorable characteristics including simple body struc- ture, rapid growth, thriving reproduction and short generation interval to tolerate harsh environment better.

[Geochemical distribution of dissolved bismuth in the Yellow Sea and East China Sea].

Occurrence level, geochemical distribution of dissolved bismuth and its coupling relationship to eco-environment were investigated in the Yellow Sea and East China Sea to explore the source and influencing factors. The results showed that the concentration of dissolved bismuth was within the range of 0-0. 029 microg x L(-1) at the surface and 0.

[Deposition and burial of organic carbon in coastal salt marsh: research progress].

Coastal salt marsh has higher potential of carbon sequestration, playing an important role in mitigating global warming, while coastal saline soil is the largest organic carbon pool in the coastal salt marsh carbon budget. To study the carbon deposition and burial in this soil is of significance for clearly understanding the carbon budget of coastal salt marsh. This paper summarized the research progress on the deposition and burial of organic carbon in coastal salt marsh from the aspects of the sources of coastal salt marsh soil organic carbon, soil organic carbon storage and deposition rate, burial mechanisms of soil organic carbon, and the relationships between the carbon sequestration in coastal salt marsh and the global climate change.

[Environmental characteristics of heavy metals in surface sediments from the Huanghe estuary].

The contents of Cu, Pb, Zn, Cr, As and Hg in surface sediment from 14 sampling sites in the Huanghe estuary during July-August, 2011 were measured to investigate environmental geochemical characteristics of heavy metals related to multiple factors. The distribution, relationship with fine fraction and TOC, and sediment quality assessment concerning heavy metals were analyzed. The results showed that average concentrations of Cu, Pb, Zn, Cr, As and Hg in the Huanghe estuary were (16.

[Weight of evidence (WOE) approach and its application in sediment quality assessment of coastal ecosystem: a review].

At present, chemical approaches are the main tools adopted to assess the contaminated sediments along China's coast. However, with the crucial progress of weight of evidence (WOE) approach in both logic and practice, this approach is getting available to be applied in the sediment quality assessment of our coastal ecosystem. By incorporating the levels of evidences such as sediment chemistry, toxicity and benthic community ecology, WOE forms an integrated approach to assess the potential adverse biological effects of environmental stressors mainly toxic substances by reconciling the information from multiple relevant lines of evidences and by weighing the data quality, study design, and other factors, being the sole means currently available to characterize the actual sediment quality and to reach an environmental decision.

[Variation characteristics and potential ecological risk assessment of heavy metals in the surface sediments of Bohai Bay].

The geochemical characteristics of eight heavy metals (Cd, Co, Cr, Cu, Ni, Pb, V and Zn) in two sediment cores from Bohai Bay, North China, were studied. Sediment samples were collected from 27 stations in spring 2008. A sequential extractions, procedure was used to gain their fractionation information.

Behaviors of dissolved antimony in the Yangtze River Estuary and its adjacent waters.

Antimony is a naturally occurring and cumulatively toxic element. With increasing concern as an inorganic contaminant, research on its environmental behavior is becoming a necessity. However, very little is known about this element.

Environmental geochemistry reflected by rare earth elements in Bohai Bay (North China) core sediments.

In Bohai Bay sediment, two cores were collected to estimate the source of sediments, and assess the environmental changes. Sequential extractions were carried out in this study. Rare earth elements (REE) were leached out from four labile fractions: Exchangeable (L1), Bound to carbonates (L2), Bound to Fe-Mn oxides (L3), Bound to organic matter (L4), and the remainder was Residual (R5).

[Marine inorganic carbon system responses to macro-DIN supply coupled with Ulva pertusa in simulated experiments].

Effects of macronutrient (NO3(-) -N and NH4(+) -N) on inorganic carbon system of water with Ulva pertusa existed were studied in laboratory simulation experiments. The results demonstrated that nutrient enrichment induced DIC, HCO3- and p(CO2) decreased while pH and CO3(2-) increased. The seawater changed from carbon source to carbon sink.

[Effects of typical organic pollutants on marine dioxide carbon system in simulated experiments].

The effects of typical organic pollutants (ethanol, acetone, ON, OP) on pH and marine carbon dioxide system were investigated in laboratory simulated experiments. The results indicated that the growth of biological carbon fixed system was promoted by ethanol and acetone of low concentration (< 0.5 mmol x L(-1)) (t = 7 d).