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Myristic acid-palmitic acid-tetradecanol/expanded graphite (MA-PA-TD/EG) and myristic acid-stearic acid-lauric acid/ expanded graphite (MA-SA-LA/EG) were obtained. MA-PA-TD/EG and MA-SA-LA/EG for the optimum mass ratio of 8:1 were investigated by DSC, FT-IR, TG, and SEM, and it was shown that MA-PA-TD and MA-SA-LA phase change materials were evenly distributed in expanded graphite through capillary force. Phase transition temperatures of MA-PA-TD/EG and MA-SA-LA/EG before and after cooling and heating cycles were 34.14, 34.39 °C and 30.21, 30.33 °C, respectively, and MA-PA-TD/EG and MA-SA-LA/EG had good stability. On the other hand, MA-PA-TD/EG was 67% faster than that of MA-PA-TD during solid-liquid phase change, and MA-SA-LA/EG was 63% faster than that of MA-SA-LA. Meanwhile, MA-PA-TD/EG and MA-SA-LA/EG had good thermal stability and heat storage according to thermogravimetric experiments. Therefore, MA-PA-TD/EG and MA-SA-LA/EG are suitable for practical application in buildings.

The density and viscosity of liquid 1-dodecanol and 1,12-dodecanediol were reported, which were obtained simultaneously by using a vibrating-wire viscometer. The measurements were determined at tem...

Norfloxacin nicotinate (NOR-N), an adduct of norfloxacin (NOR) and nicotinic acid, has been widely used for replacing NOR in animal husbandry and fishery industry. Nowadays, increasing evidences showed that NOR could pose toxic effects on fish and other aquatic organisms, but as its adduct, whether NOR-N could cause adverse effects on aquatic organisms is still unclear. To evaluate the toxic effects of NOR-N on the early life stage of zebrafish, we determined the changes in embryonic development (hatching rate, body length, malformation rate and mortality), antioxidant enzyme (superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (Gpx)) activities, malondialdehyde (MDA) content and gene expression levels related to antioxidant enzymes (Cu/Zn-sod, Mn-sod, CAT and Gpx) and innate immune system (tumor necrosis factor α (TNFα), interferon (IFN), Interleukin-1 beta (IL-1β), IL-8, CXCL-clc, CC-chemokine, lysozyme (Lzy) and complement factors (C3)) after embryonic exposure to NOR-N till 96 hpf. The results showed that NOR-N exposure could decreased the hatching rate and body length, and increased abnormality and mortality as concentration-dependent during embryonic development process. NOR-N induced oxidative stress in zebrafish larvae through increasing the contents of MDA and the activities of SOD, CAT and Gpx, as well as the mRNA levels of genes related to these antioxidant enzymes. Moreover, the expression of TNFα, IFN, IL-1β, IL-8, CXCL-clc, CC-chemokine, Lzy and C3 genes were significantly up-regulated after exposure to high concentration (5 and/or 25 mg/L) of NOR-N till 96 hpf, indicating that the innate immune system in zebrafish larvae was disturbed by NOR-N. Overall, our results suggested that NOR-N caused development toxicity, oxidative stress and immunotoxicity on the early life stage of zebrafish. Thus, widespread application of NOR-N might pose potential ecotoxicological risk on aquatic ecosystems.

Photodegradation of the insecticide pymetrozine (PYM) was studied on surface of wax films, and in aqueous and nonaqueous phase. The half-life of PYM on the wax surface was approximately 250 times longer than in water. Scavenging experiments, laser flash photolysis, and spectra analysis indicated the first singlet excited state of PYM (S1 *PYM) to be the most important photoinduced species initiating the photodegradation. Quantum chemistry calculations identified significant molecular torsion and changes in the structure C–C N–N of S1 *PYM, and the absolute charges of the C N atoms increased and the bond strength weakened. Free energy surface analysis, and O18 labeling experiments further confirmed that the mechanism was two-step photoinduced hydrolysis. The first step is the hydrolysis of S1 *PYM at C N upon reaction with 2–3 water molecules (one H2O molecule as the catalyst). The second step is an intramolecular hydrogen transfer coupled with the cleavage of C–N bond and formation of two cyclic products. During the interactions, water molecules experience catalytic activation by transferring protons, while there is a negligible solvent effect. Clarifying the detailed photodegradation mechanisms of PYM is beneficial for the development of green pesticides that are photostable and effective on leaf surfaces, and photolabile and detoxified in the aquatic environment.

“Liver and gall syndrome” disease often caused dramatic economic losses in swamp eel (Monopterus albus) which is one of the most economically important freshwater aquaculture fish in China. Carbon tetrachloride (CCl4)-induced liver injury model has been evidenced as a useful method to screen the hepatoprotective agents to study and prevent this disease in fish. Therefore, in order to provide a better research platform for prevention and treatment liver diseases in swamp eel, we evaluated the hepatotoxicity effects of CCl4 on swamp eel based on the acute toxicity and biochemical responses of glutamate pyruvate transaminase (GPT), glutamate oxalate transaminase (GOT), lactate dehydrogenase (LDH), catalase (CAT), superoxide dismutase (SOD) and malondialdehyde (MDA), as well as mRNA expression levels of cyclooxygenase-1 (COX-1), cyclooxygenase-2 (COX-2) and 5-lipoxygenase (5-LO). The 96 h LD50 value of CCl4 in swamp eel was 2.54 g/kg. Sublethal levels of CCl4 induced time-depended liver injury in swamp eel, evidenced by the significant increases of serum GPT, GOT and LDH levels at the first 48 h injection, but restoration after 96 h injection. CCl4 led to oxidative stress, supported by the enhanced of MDA contents, and decreased of SOD and CAT activities. Moreover, CCl4 caused hepatic inflammatory reaction, evidenced by the significant changes of the transcription of COX and 5-LO genes in liver tissues. Overall, our results suggested that lipid peroxidation, antioxidant enzymes and COX and 5-LO pathways are important mechanisms involved in CCl4-induced liver injury, and could be used as the effective biomarkers of CCl4-induced liver injury model to screen the hepatoprotective agents in swamp eel.

Tonalide was extensively used as fragrances in various personal care products and recognized as emerging contaminant recently. In this study, the transient reactions of hydrophobic tonalide with hydroxyl radical ( OH), one of highly reactive oxygen species (ROSs), was firstly investigated in acetonitrile through direct observation using laser flash photolysis. Two transient intermediates were formed with the peak centered at 360 and 450 nm, and the bimolecular reaction rate constants of tonalide with OH were determined in both water and acetonitrile solutions with values of 4.04 × 109 and 1.95 × 109 M−1 s−1, respectively. Then, the photocatalytic experiments in a heterogeneous TiO2 system were carried out to study the decomposition kinetics of tonalide with OH, which was confirmed as the dominant ROSs in photocatalytic system. Five degradation products were identified with molecule weight of 260, 272 and 274. Finally, the potential risks of reaction products formed through the reactions of tonalide with OH were further investigated. It is found that the toxicity towards luminescent bacterium (Photobacterium phosphoreum) was not changed so much, and the estrogenic activity increased a little bit during the degradation of tonalide by OH.

In this work, density and viscosity of 1-hexadecanol were measured over the temperature range from (328.15 to 623.15) K and at pressures up to 10 MPa. The experimental data of density and viscosity were obtained simultaneously by using a vibrating-wire instrument operated in the forced mode of oscillation. The combined expanded uncertainties of these results, with a confidence level of 0.95, were 0.26% for density and 2.1% for viscosity. Correlations of the experimental results were presented, and comparisons were also made with various sets of data from the literature. The average absolute deviation and the maximum absolute deviation of the experimental data from the correlations are 0.07% and 0.17% for density, and 0.61% and 1.83% for viscosity, respectively.

Environmental contextPhotodegradation, a natural process for removing pesticides from water, is particularly important in rice fields with their large surface area and sunlight exposure. By studying two commonly used pesticides, we show that the properties of rice field water, such as dissolved organic matter, facilitate indirect photolytic processes while reducing direct photolysis. A better understanding of the natural degradation mechanisms for pesticides will inform their safer use in agriculture. AbstractRice paddy fields (RFs) make ecologically important contributions to agricultural wetland ecosystems in south China. In recent years, the elevated use of pesticides has resulted in concerns over the water quality in RFs and their downstream aquatic environment. Photodegradation is important for the natural elimination of nonpoint source agricultural contaminants, and RF water provides an ideal environment for the photochemical removal of pesticides, owing to its large surface area and photic conditions. Therefore, in this study, the physical and photochemical properties of water collected from the irrigation area were investigated, along with the direct and indirect photodegradation of two commonly used pesticides in RFs, tricyclazole (TC) and pymetrozine (PYM). Results indicated that allochthonous-like dissolved organic matter (DOM) was abundant in the irrigation water, possibly originating from the decomposition of rice straw. Moreover, the light screen effect and the formation rate of singlet oxygen (1O2) and the triplet excited state of DOM (3DOM*) were generally increased in RF water, while the formation of HO• was marginally reduced. Evapoconcentration and photobleaching processes were found to correlate with crop leaf coverage and had a significant impact on the levels and compositions of water constituents. Finally, the photodegradation kinetics of TC and PYM further confirmed that RF water would facilitate indirect photolysis and reduce the direct photolysis of pesticides.

An understanding of the thermal performance of biological tissue under moxibustion with ash cleaning and distance adjustment (ACDA) is helpful for the optimization and standardization of moxibustion clinical treatment. This study compared surface temperature distribution of burning moxa stick with and without ash cleaning. The experimental of moxibustion treatment on in-vitro tissue and human abdomen were conducted and corresponding numerical models were developed. The effect of ACDA on thermal performance of biological tissue under moxibustion therapy were analyzed. The results show that the surface temperature of burning moxa stick with ash cleaning maintained at a higher range compared to that without ash cleaning. During moxibustion with ACDA process in in-vitro tissue experiment, the temperature increase (ΔT) at skin surface almost fluctuated in the same temperature range, and the ΔT in subcutaneous tissue (>11 mm) kept increasing. Relatively, these ΔT under moxibustion treatment without ACDA showed different trends and these values were all much smaller than those with ACDA. In addition, the position of maximum temperature of tissue under moxibustion with and without ACDA was fixed on treatment acupoint and moved away from treatment acupoint, respectively. Besides, the surface temperature of human abdomen tissue under moxibustion treatment with ACDA can be maintained at 46 °C–50 °C for a longer time compared to that under moxbustion without ACDA. In conclusion, moxibustion with ACDA can create a larger and more durable thermal effect on biological tissue. The results also suggest that ACDA may be helpful to improve moxibustion therapy efficacy in clinic treatments.

Antibiotic resistance genes (ARGs), as a newly emerging contaminant, are unique because they are disseminated through horizontal gene transfer in the environment. In the present study, a class 1 integron gene (int1) and various ARGs (sul1, sul2, sul3, qnrS, and ermB) were measured in water and sediment samples from the Pearl River (PR) to the Pearl River Estuary (PRE), where there is a distinct gradient in anthropogenic impact. The int1, sul1, and sul2 genes were detected in all samples, and their concentrations exhibited a clear trend of decline consistent with anthropogenic impact. Both the int1 and sul genes had dynamically migrated between water and sediments. The relative abundance of the int1 gene normalized to the 16S rRNA gene correlated significantly with the total concentrations of antibiotics in water and sediments. Good correlations were also observed between the abundance of int1 and each type of sul gene in the samples. However, the sul1 gene showed a much stronger relationship with int1 in different seasons, probably due to the presence of sul1 in the conserved region of class 1 integron. Our results strongly support that integrons play an important role in the dissemination of ARGs in human-impacted aquatic environments.

During the summer of 2011, a severe drought event occurred throughout the Zhujiang (Pearl) River Basin of South China. This decreased runoff into the river, resulting in increased salinity and reduced suspended substance. To examine the effects of this extreme drought on the distribution of nutrients and chlorophyll, we compared two surveys from 2006 and 2011. Results show that dissolved inorganic nitrogen concentration did not change from 2006 to 2011, whereas the proportions of NO2− and NH4+ to DIN in 2011 increased. PO43− concentration was lower in 2011 than in 2006, whereas there was no difference in SiO32− concentration between these years. Correlation coefficients of salinity with levels of NO3−, NO2−, NH4+, PO43− and SiO32− in 2011 were all much higher than those in 2006, suggesting greater conservation of dissolved nutrients during the extreme drought event. Furthermore, calculated amounts of regenerated nitrate and phosphorus and their proportions to observed nutrients in 2011 were much lower than in 2006, indicating that nutrient regeneration decreased during the extreme drought period. Mean concentration of chlorophyll a (Chl-a) was considerably higher in 2011 than in 2006, and a harmful algal bloom of Cochlodinium geminatum was observed in the estuary, owing to water stagnancy and lower turbidity as a consequence of drought. Therefore, the extreme drought event in 2011 changed the composition ratio of nutrients, enhanced nutrient conservative behavior, and reduced nutrient regeneration. This affected some key ecological processes in the estuary.

Wetland construction is a recommended domestic sewage treatment technique, owing to its simplicity and cost efficiency. Concentrations of 14 antibiotic resistance genes (ARGs) in an integrated surface flow constructed wetland (ICW) steadily operated over 10 years were investigated in the winter and summer. Domestic sewage was observed to be the primary source of ARGs in the ICW, and 77.8% and 59.5% removal rates of total targeted ARGs in the ICW were achieved in the winter and summer, respectively. Concentrations of five ARGs (sul1, tetA, tetC, tetE, and qnrS) in the winter and of six ARGs (sul1, sul3, tetA, tetC, tetE, and qnrS) in the summer were increased throughout the treatment process. Strong correlations were found between ARGs in water and those found in sediments, especially in the summer, indicating that ARGs may be exchanged between water and sediment. Strong positive correlations were also observed between concentrations of intI1 and several ARGs, implying that mobile genetic elements may play a key role in the dissemination of ARGs in an ICW. Our study results suggest aqueous ARGs could be effectively removed via an ICW and that ICWs can also act as reservoirs of specific ARGs.

The impact of typical pollutants upon the fish-farming was assessed by use of a battery of biomarkers in two typical marine aquaculture regions in South China. Biotransformation parameters including 7-ethoxyresorufin-O-deethylase (EROD), aminopyrine N-demethylase (APND), erythromycin N-demethylase (ERND), glutathione-S-transferase (GST) and Malondialdehyde (MDA) were measured in five cultured fish species. Pollutants such as polycyclic aromatic hydrocarbon (PAHs), organochlorinated compounds (OCs), heavy metals and antibiotics (quinolones and sulfonamides) in sediments were characterized. Higher pollutant residue levels were observed in Dapeng Cove. EROD, APND and ERND activities were lower in fish from Dapeng Cove compared with fish from Hailing Island, while it is just on the contrary for GST and MDA. ERND, APND and GST showed sensitivity corresponding to different pollutants. Small fish species seemed to exhibit more sensitive to pollutants. The study further supports usefulness of multi-biomarker approach considering multiple species to define the effects of anthropogenic inputs in marine aquaculture systems.

The presence of antibiotics including norfloxacin in the aquatic environment may cause adverse effects in non-target organisms. But the toxic mechanisms of fluoroquinolone to fish species are still not completely elucidated. Thus, it is essential to investigate the response of fish to the exposure of fluoroquinolone at molecular or cellular level for better and earlier prediction of these environmental pollutants toxicity. The sub-chronic toxic effects of norfloxacin (NOR) on swordtail fish (Xiphophoru s helleri) were investigated by measuring mRNA expression of cytochrome P450 1A (CYP1A), cytochrome P450 3A (CYP3A), glutathione S-transferase (GST) and P-glycoprotein (P-gp) and their corresponding enzyme activities (including ethoxyresorufin O-deethylase, erythromycin N-demethylase and GST. Results showed that NOR significantly affected the expression of CYP1A, CYP3A, GST and P-gp genes in swordtails. The gene expressions were more responsive to NOR exposure than their corresponding enzyme activities. Moreover, sexual differences were found in gene expression and enzyme activities of swordtails exposed to NOR. Females displayed more dramatic changes than males. The study further demonstrated that the combined biochemical and molecular parameters were considered as useful biomarkers to improve our understanding of potential ecotoxicological risks of NOR exposure to aquatic organisms.

Knowledge of the origins and dissemination of antibiotic resistance genes (ARGs) is essential for understanding modern resistomes in the environment. The mechanisms of the dissemination of ARGs can be revealed through comparative studies on the metagenomic profiling of ARGs between relatively pristine and human-impacted environments. The deep ocean bed of the South China Sea (SCS) is considered to be largely devoid of anthropogenic impacts, while the Pearl River Estuary (PRE) in south China has been highly impacted by intensive human activities. Commonly used antibiotics (sulfamethazine, norfloxacin, ofloxacin, tetracycline, and erythromycin) have been detected through chemical analysis in the PRE sediments, but not in the SCS sediments. In the relatively pristine SCS sediments, the most prevalent and abundant ARGs are those related to resistance to macrolides and polypeptides, with efflux pumps as the predominant mechanism. In the contaminated PRE sediments, the typical ARG profiles suggest a prevailing resistance to antibiotics commonly used in human health and animal farming (including sulfonamides, fluoroquinolones, and aminoglycosides), and higher diversity in both genotype and resistance mechanism than those in the SCS. In particular, antibiotic inactivation significantly contributed to the resistance to aminoglycosides, β-lactams, and macrolides observed in the PRE sediments. There was a significant correlation in the levels of abundance of ARGs and those of mobile genetic elements (including integrons and plasmids), which serve as carriers in the dissemination of ARGs in the aquatic environment. The metagenomic results from the current study support the view that ARGs naturally originate in pristine environments, while human activities accelerate the dissemination of ARGs so that microbes would be able to tolerate selective environmental stress in response to anthropogenic impacts.

Antibiotics released into the aquatic environment play an important role in the spread of antibiotic resistance. In the Pearl River Estuary (PRE) and the coastal zone, the concentrations of antibiotics decreased from the Pearl River to the estuary, suggesting that antibiotics primarily originated from river tributaries and terrigenous sources. Within the PRE area, the concentrations of antibiotics in water were higher in the west coast than the east side, reflecting the high density of anthropogenic activities and hydraulic conditions along the west riverbank. Seasonal variations were also observed for most of detected antibiotics in water. The pseudo-partitioning coefficient of norfloxacin had a good correlation with the TOC content of sediments, as did erythromycin-H2O with the pH of water. The results suggest that environmental conditions can significantly affect the distribution of antibiotics between water and sediment. (C) 2013 Elsevier Ltd. All rights reserved.

Antibiotic resistance genes (ARGs) are increasingly a focus of concern because they pose a potential health risk. The Pearl River (PR) and Pearl River Estuary (PRE) show a distinct gradient in anthropogenic impacts, in particular associated with the use of antibiotics, from the river, to the estuary, and on to the coast. In this study, two surveys were conducted in the PR and PRE areas during the winter and summer of 2011, respectively. Seven tet genes consisting of efflux pump (tetA, tetC, and tetH) and ribosomal protection proteins (tetB, tetM, tetO, and tetW) were analyzed using the polymerase chain reaction (PCR) technique. The tet genes, with the exception of tetA and tetH, were widely detected in the PR and PRE environments. The tet genes exhibited a trend of an increase in total concentration and diversity with the degree of anthropogenic impacts from the river to the coast, indicating that riverine input was the main source of ARGs in the region. Significant correlations were observed between tet genes and antibiotic concentrations, as well as among different environmental compartments (water and sediments). The distribution patterns of tet genes were similar between the potential sources of pollution and the highly-impacted sites, but were significantly different between less-impacted sites and highly-impacted ones or pollution sources. The results suggest that ARGs and antibiotics may be released from identical sources, and transported in a similar manner in estuary/coastal environments close to sources of pollution.

Surface sediments can provide useful information on the recent pollution status of an estuary. One recent field survey was carried out in the Pearl River Estuary (PRE), South China in 2011. The comparisons with previous surveys demonstrated that the concentrations of Ni and Pb in the PRE declined over the last decade, but the concentration of Cu increased in the same time frame. The significant decreases in the concentrations of Ni and Pb were probably due to a reduction of anthropogenic inputs, such as industrial wastewater, into the PRE environment, and the ban imposed on leaded gasoline. Statistical analyses have consistently demonstrated that the process of the sedimentation of fine particles was the dominant factor in controlling the transport and distribution of trace metals in the PRE. The riverine trace metals generally displayed a pattern of diffusion from the northwest to the southeast in the estuary. However, the riparian industrial activities at the east bank of the inner PRE caused significant metal contamination in sediments. In general, effective pollution control measures in the PRD region have decreased the levels of some trace metals in the entire PRE over the last decade with the exception of Cu. (C) 2012 Elsevier B.V. All rights reserved.

The toxic effects of triclosan (TCS) on the swordtail fish ( Xiphophorus helleri ) were assessed based on various biomarkers including enzymatic activities of ethoxyresorufin O-deethylase (EROD), erythromycin N-demethylase (ERND) and glutathione-s-transferase (GST) and mRNA expression levels of CYP1A, CYP3A, glutathione S-transferase (GST) and P-glycoprotein (P-gp). The acute toxicity test showed the LC 50 value of 1.47 mg L −1 for TCS. The mRNA expressions of CYP1A, CYP3A, GST and P-gp showed dose–effect relationships in female swordtail fish when exposed to TCS, These mRNA expression levels were found more sensitive to TCS exposure than the enzymatic activities of EROD, ERND and GST do. In addition, the male fish displayed higher gene expression levels and more dramatic changes in enzyme activities than the females did. Our data further demonstrated that TCS was a typical inducer to Phase I and Phase II metabolism enzymes and genes, suggesting it is a potential ecotoxicological risk to aquatic ecosystems.

Organic pollutants, heavy metals and pharmaceuticals are continuously dispersed into the environment and have become a relevant environmental emerging concern. In this study, a situ assay to assess ecotoxicity of mixed pollutants was carried out in three typical sites with different priority contaminations in Guangzhou, China. Chemical analysis of organic pollutants, metals and quinolones in three exposure sites were determined by GC–ECD/MS, ICP-AES and HPLC, as well as, a combination of biomarkers including: ethoxyresorufin O-deethylase (EROD); aminopyrine N-demethylase (APND); erythromycin N-demethylase (ERND); glutathione S-transferase (GST); malondialdehyde (MDA); CYP1A; and P-glycoprotein (P-gp) mRNA expressions were evaluated in Mugilogobius abei. Results of chemical analysis in sediment samples revealed that the dominant chemicals were organic pollutants and heavy metals in Huadi River while quinolones in the pond. Bioassays indicated that differences among sites were in relation to some specific biomarkers. EROD and GST activities significantly increased after 72 h in situ exposure, but no difference was observed among the exposure sites. APND, ERND and MDA exhibited dissimilar change patterns for different priority pollutants. CYP1A and P-gp mRNA expressions were significantly induced at all exposure sites, whilst P-gp activity was typical for S2 with the highest levels of quinolones. The molecular biomarkers seemed to be more susceptible than enzyme activities. These assays confirmed the usefulness of applying a large array of various combined biomarkers at different levels, in assessing the toxic effects of mixed pollutants in a natural aquatic environment.