Antibiotics in the offshore waters of the Bohai Sea and the Yellow Sea in China: Occurrence, distribution and ecological risks

The ocean is an important sink of land-based pollutants. Previous studies showed that serious antibiotic pollution occurred in the coastal waters, but limited studies focused on their presence in offshore waters. In this study, eleven antibiotics in three different categories were investigated in offshore waters of the Bohai Sea and the Yellow Sea in China. The results indicated that three antibiotics dehydration erythromycin, sulfamethoxazole and trimethoprim occurred throughout the offshore waters at concentrations of 0.10-16.6 ng L-1 and they decreased exponentially from the rivers to the coastal and offshore waters. The other antibiotics all presented very low detection rates (<10%) and concentrations (<0.51 ng L-1). Although the concentrations were very low, risk assessment based on the calculated risk quotients (RQs) showed that sulfamethoxazole, dehydration erythromycin and clarithromycin at most of sampling sites posed medium or low ecological risks (0.01 < RQ < 1) to some sensitive aquatic organisms, including Synechococcus leopoliensis and Pseudokirchneriella subcapitata. (C) 2012 Elsevier Ltd. All rights reserved.The ocean is an important sink of land-based pollutants. Previous studies showed that serious antibiotic pollution occurred in the coastal waters, but limited studies focused on their presence in offshore waters. In this study, eleven antibiotics in three different categories were investigated in offshore waters of the Bohai Sea and the Yellow Sea in China. The results indicated that three antibiotics dehydration erythromycin, sulfamethoxazole and trimethoprim occurred throughout the offshore waters at concentrations of 0.10-16.6 ng L-1 and they decreased exponentially from the rivers to the coastal and offshore waters. The other antibiotics all presented very low detection rates (<10%) and concentrations (<0.51 ng L-1). Although the concentrations were very low, risk assessment based on the calculated risk quotients (RQs) showed that sulfamethoxazole, dehydration erythromycin and clarithromycin at most of sampling sites posed medium or low ecological risks (0.01 < RQ < 1) to some sensitive aquatic organisms, including Synechococcus leopoliensis and Pseudokirchneriella subcapitata. (C) 2012 Elsevier Ltd. All rights reserved

Analysis of the genetic architecture of maize kernel size traits by combined linkage and association mapping

Kernel size‐related traits are the most direct traits correlating with grain yield. The genetic basis of three kernel traits of maize, kernel length (KL), kernel width (KW) and kernel thickness (KT), was investigated in an association panel and a biparental population. A total of 21 single nucleotide polymorphisms (SNPs) were detected to be most significantly (P \u3c 2.25 × 10−6) associated with these three traits in the association panel under four environments. Furthermore, 50 quantitative trait loci (QTL) controlling these traits were detected in seven environments in the intermated B73 × Mo17 (IBM) Syn10 doubled haploid (DH) population, of which eight were repetitively identified in at least three environments. Combining the two mapping populations revealed that 56 SNPs (P \u3c 1 × 10−3) fell within 18 of the QTL confidence intervals. According to the top significant SNPs, stable‐effect SNPs and the co‐localized SNPs by association analysis and linkage mapping, a total of 73 candidate genes were identified, regulating seed development. Additionally, seven miRNAs were found to situate within the linkage disequilibrium (LD) regions of the co‐localized SNPs, of which zma‐miR164e was demonstrated to cleave the mRNAs of Arabidopsis CUC1, CUC2 and NAC6 in vitro. Overexpression of zma‐miR164e resulted in the down‐regulation of these genes above and the failure of seed formation in Arabidopsis pods, with the increased branch number. These findings provide insights into the mechanism of seed development and the improvement of molecular marker‐assisted selection (MAS) for high‐yield breeding in maize

Compound astragalus and salvia miltiorrhiza extract exerts anti-fibrosis by mediating TGF-beta/smad signaling in myofibroblasts

Previous studies showed that Compound Astragalus and Salvia miltiorrhiza Extract (CASE) has a protective effect against liver fibrosis. We hypothesized that CASE exerts the anti-fibrosis effect by mediating transforming growth factor-β (TGF-β)/Smad signaling pathway. To test this hypothesis, we induced fibrosis in rats by twice weekly injections of carbon tetrachloride (CCl) and Smad2 phosphorylation was measured by immunohistochemical method; protein expression in myofibroblasts (MFBs) induced by TGF-β1 was analyzed by western blotting and plasminogen activator inhibitor type 1 (PAI-1) transcriptional activity in MFBs was evaluated. The present study showed that, in vivo, CASE has protective effects against liver fibrosis in rats generated by CCl, and that CASE inhibits Smad2 phosphorylation at C-terminal region and expression of α-smooth muscle actin (α-SMA). Our experiment further demonstrated that, in vitro, (1) CASE inhibits TGF-β-dependent Smad2 phosphorylation at C-terminal region and Smad2 and Smad3 phosphorylation at linker region in MFBs in a dose-dependent manner; (2) CASE decreases the level of Smad 2/3/4 complex in MFBs induced by TGF-β in a dose-dependent manner; (3) CASE inhibits PAI-1 transcriptional activity in MFBs induced by TGF-β in a dose-dependent manner; and (4) CASE markedly decreases c-Jun N-terminal kinase (JNK) phosphorylation in MFBs induced by TGF-β. Our results suggest that CASE's anti-fibrosis effect in chronically injured liver was exerted by inhibiting TGF-β/Smads signal transduction

Gold-catalyzed tandem 1,3-migration/double cyclopropanation of 1-Ene-4,n-diyne esters to tetracyclodecene and tetracycloundecene derivatives

A synthetic method that relies on Au(I)-catalyzed tandem 1,3-acyloxy migration/double cyclopropanation of 1-ene-4,9-diyne and 1-ene-4,10-diyne esters to construct the respective architecturally challenging tetracyclodecene and tetracycloundecene derivatives is described. Achieved under mild reaction conditions, the transformation was shown to be robust with a wide variety of substitution patterns tolerated to give the two members of the carbocyclic family in good to excellent yields and as a single regio- and diastereomer

Determination and human health risk assessment of TFWT, OBT and carbon-14 in seafood around Qinshan Nuclear Power Plant

This work aims to evaluate the effects of the operation of Qinshan nuclear Power Plant (QNPP) on tritium (3H) and carbon-14 (14C) levels in seafood and assess the health risks caused by seafood consumption. Five kinds of seafood, including marine fish, prawn, razor clam, crabs, and seaweed, were collected from QNPP and the sea around Hangzhou Bay. The activity concentrations of tissue free water tritium (TFWT), organically bound tritium (OBT) and 14C were determined, respectively, and the annual intake and annual effective dose (AED) were calculated. The results showed that the TFWT, OBT, and 14C activity concentrations of the seafood in the surrounding area of QNPP ranged from 2.00 to 74.75 Bq/L, <1.04 to 19.68 Bq/L and 0.09 to 0.17 Bq/g·C, respectively. The TFWT, OBT, and 14C activity concentrations of the seafood in Hangzhou Bay ranged from 1.36 to 10.55 Bq/L, 1.08 to 6.78 Bq/L and 0.07 to 0.13 Bq/g·C, respectively. The differences were not statistically significant. The total AED from 3H and 14C due to the seafood consumption for the residents in the surrounding of QNPP and Hangzhou Bay were 1.96 × 10−4 and 1.61 × 10−4 mSv/year, respectively. The results showed that the operation of QNPP had no obvious effect on 3H and 14C accumulation in seafood, and the dose burden of population was low

Occurrence and risks of antibiotics in the Laizhou Bay, China: Impacts of river discharge

The presence of thirteen antibiotics categorized into four different groups (fluoroquinolones, macrolides, sulfonamides and trimethoprim) was investigated in the rivers discharging to the Laizhou Bay and the seawater of the bay, and the impacts of river discharge on the marine environment were assessed. The results revealed that the same antibiotics predominated in both the river water and the seawater. Additionally, the detected antibiotics in the river water were generally higher than those in the inner bay and in the open bay, reflecting the importance of the riverine inputs as a source of antibiotics. Risk assessment based on the calculated risk quotients (RQ) showed that enoxacin, ciprofloxacin, and sulfamethoxazole in the two aquatic environments both posed high ecological risks (RQ > 1) to the most sensitive aquatic organisms Vibrio fischeri, Microcystis aeruginosa and Synechococcus leopoliensis, respectively. (C) 2012 Elsevier Inc. All rights reserved.The presence of thirteen antibiotics categorized into four different groups (fluoroquinolones, macrolides, sulfonamides and trimethoprim) was investigated in the rivers discharging to the Laizhou Bay and the seawater of the bay, and the impacts of river discharge on the marine environment were assessed. The results revealed that the same antibiotics predominated in both the river water and the seawater. Additionally, the detected antibiotics in the river water were generally higher than those in the inner bay and in the open bay, reflecting the importance of the riverine inputs as a source of antibiotics. Risk assessment based on the calculated risk quotients (RQ) showed that enoxacin, ciprofloxacin, and sulfamethoxazole in the two aquatic environments both posed high ecological risks (RQ > 1) to the most sensitive aquatic organisms Vibrio fischeri, Microcystis aeruginosa and Synechococcus leopoliensis, respectively. (C) 2012 Elsevier Inc. All rights reserved

Syntheses and proton conductivity of mesoporous Nd₂O₃-SiO₂and NdOCl-SiO₂ composites

Two mesoporous oxide composites of Nd2O3-SiO2 and NdOCl-SiO2 were synthesized using SBA-15 as a template and neodymium nitrate or neodymium chloride as a precursor. The porous Nd2O3-SiO2 with a SBA-15-like structure has amorphous walls and the porous NdOCl-SiO2 with a replicated structure of SBA-15 has crystalline walls. These porous materials were characterized by X-ray diffraction, transmission electron microscopy and nitrogen adsorption/desorption. They exhibited significant proton conductivities in the presence of moisture at low temperatures and the highest conductivity observed was 4.55 x 10(-4) S/cm at 47 A degrees C in wet air (RH = 28.6%).</p

Levels, spatial distribution and sources of selected antibiotics in the East River (Dongjiang), South China

Eleven selected antibiotics in the East River, South China, were measured using high performance liquid chromatography-electrospray ionization tandem mass spectrometry (HPLC-EI-MS-MS). Erythromycin, roxitromycin, azithromycin, clarithromycin, sulfadimidine, sulfamethoxazole, sulfadiazine and trimethoprim were detected with frequencies of more than 75%, and average concentrations ranging from 0.9 to 67.4 ng l(-1). The other three compounds' (sulfathiazole, sulfacetamide and spiramycin) concentrations were below detection limits. In general, the concentrations of sulfonamides and trimethoprim were higher than those of macrolides. The concentrations of macrolides showed a spatial distribution pattern of delta > lower reach > middle reach (or urban area > agriculture area), while sulfonamides and trimethoprim did not have a significant spatial pattern. Principal component analysis and comparison with wastewater were further used to explore source information of the antibiotics. The results suggested that macrolides in the East River were mainly associated with domestic sewage, while sulfonamides and trimethoprim may be more related to agriculture wastewater, especially livestock industrial wastewater. It is suggested that to ensure/improve the drinking water quality in the region, a better pollution control of livestock industry in the lower and middle reaches is of critical importance.Eleven selected antibiotics in the East River, South China, were measured using high performance liquid chromatography-electrospray ionization tandem mass spectrometry (HPLC-EI-MS-MS). Erythromycin, roxitromycin, azithromycin, clarithromycin, sulfadimidine, sulfamethoxazole, sulfadiazine and trimethoprim were detected with frequencies of more than 75%, and average concentrations ranging from 0.9 to 67.4 ng l(-1). The other three compounds' (sulfathiazole, sulfacetamide and spiramycin) concentrations were below detection limits. In general, the concentrations of sulfonamides and trimethoprim were higher than those of macrolides. The concentrations of macrolides showed a spatial distribution pattern of delta > lower reach > middle reach (or urban area > agriculture area), while sulfonamides and trimethoprim did not have a significant spatial pattern. Principal component analysis and comparison with wastewater were further used to explore source information of the antibiotics. The results suggested that macrolides in the East River were mainly associated with domestic sewage, while sulfonamides and trimethoprim may be more related to agriculture wastewater, especially livestock industrial wastewater. It is suggested that to ensure/improve the drinking water quality in the region, a better pollution control of livestock industry in the lower and middle reaches is of critical importance