SBA-15 supported noble metal catalysts for CO oxidation have been extensively investigated. However, no reported work on the SBA-15 supported palladium catalyst for CO oxidation can be found in the literature. In this work, highly dispersed palladium nanoparticles were synthesized within the uniform channels of SBA-15 via a glow discharge plasma reduction treatment. The obtained Pd/SBA-15 catalyst shows a good activity for CO oxidation. The activity can be further improved by the hydrogen reduction thermally. The low-angle X-ray diffraction (XRD) patterns and transmission electron microscope (TEM) indicate that the ordered mesoporous structure was well maintained during the catalyst preparation and reaction processes. The wide-angle XRD patterns and TEM images show that the spherical palladium nanoparticles are highly dispersed within the SBA-15 channels and remain stable after the reaction. The diffuse reflectance infrared Fourier transformation (DRIFT) spectroscopy of adsorbed CO confirms that the structure change caused by different preparation conditions has a significant influence on the activity of the catalyst. (C) 2011 Elsevier B.V. All rights reserved.

Suppressor of cytokine signaling-1a (SOCS1a) is a member of the suppressor of cytokine signaling family, a group of related molecules that mediate the negative regulation of the JAK-STAT pathway. Here, we depleted SOCS1a using the transcription activator-like (TAL) effector nuclease (TALEN) technique to understand its physiological roles in zebrafish. Although elevated levels of JAK-STAT5 activation and erythropoiesis have been observed in socs1a-deficient zebrafish, these animals exhibited normal growth during the early stages. Socs1a-deficient zebrafish began to grow slowly with certain mortalities after 20 days postfertilization (dpf), whereas the heterozygous socs1a-deficient zebrafish exhibited enhanced somatic growth. Decreased adiposity, hepatic steatosis, and insulin resistance were observed in our socs1a-deficient adult zebrafish, which is similar to the lipodystrophy phenotypes observed in mammals. Comparative transcriptomic analyses revealed elevated levels of gluconeogenesis, lipolysis, and hypoxia-inducible response and decreased activities of lipogenesis and glycolysis in the hepatocytes of socs1a-deflicient adult zebrafish. Evident mitochondrial dysfunction has also been observed in hepatocytes from socs1a-deficient zebrafish. Taken together, our results suggest that the negative regulatory roles of SOCS1a on JAK-STAT5 signaling may be involved in the suppression of the erythropoiesis and growth hormone activities, which was also reflected in the enhanced somatic growth performance observed in the heterozygous socs1a-deficient fish. The differences in the effects caused by SOCS1a depletion on insulin sensitivity, lipid metabolism, and inflammatory responses between zebrafish and mammalian models observed here may reflect differences between the functional mechanisms of SOCS members in terrestrial mammals and aquatic teleosts.

Trin-octylphosphine oxide (TOPO) is a widely used extractant because of its high extractive ability. However, there is no systematic research on the thermodynamics of TOPO/n-dodecane in the separation of hydrochloric acid (HCl) from aqueous solution. In this study, the liquid liquid equilibrium (LLE) system (water + n-dodecane + TOPO + HCl) was investigated. Both the equimolar series and slope methods were used to determine the composition of the complex formed in the equilibrated organic phase. The form of the water molecules in the equilibrated organic phase was first investigated by the thermodynamic method. The thermodynamic model was established with the Pitzer equation for aqueous phase and both Margules and organic Pitzer equations for the organic phase. Two chemical equilibrium constants and their corresponding interaction parameters were regressed from experimental LLE data. The correlated results were in good agreement with the experimental data. Furthermore, this model can also be used to predict the organic phase composition for this system. This confirmed that the thermodynamic model chosen was suitable for the extraction system.

Previous studies showed that the endocrine disrupting chemicals (EDCs) affect reproductive physiology in teleosts. How the EDCs regulate gonadal steroidogenesis remains to be determined. The gonadal transcript changes of steroidogenic enzyme genes in adult rare minnow Gobiocypris rarus exposed to 17 alpha-ethinylestradiol (EE2) and bisphenol A (BPA) were detected in the present study. The full-length cDNAs encoding steroidogenic enzymes, including steroidogenic acute regulatory protein (StAR), cytochrome P450-mediated side-chain cleavage enzyme (CYP11A1), 3 beta-hydroxysteroid dehydrogenase (3 beta-HSD), and cytochrome P450 17 A1 (CYP17A1) were isolated and characterized by RT-PCR and RACE methods. The homology and phylogenetic analyses of the amino acid sequences confirmed that the nucleotide sequences of these steroidogenic genes were correct. The mRNA tissue distribution results indicated that StAR, cyp11a1, and cyp17a1 mRNAs were mainly expressed in the gonads and 3 beta-HSD was mainly expressed in both the gonads and the brains. The 233 dpf adult G. rams were exposed to EE2 (25 ng/L) and BPA (5, 15, and 50 mu g/L) dissolved in dimethyl sulfoxide (DMSO) or control for 7 days. The gonadal mRNA levels of StAR, cyp11a1, 3 beta-HSD, cyp17a1 and ovarian cytochrome P450 aromatase (cyp19a1a)were quantified by qRT-PCR Our data indicated that 25 ng/L EE2 had different degrees of inhibitory effects on the expression of steroidogenic genes in the gonads. BPA at different levels caused concentration-specific effects on the mRNA expression of the steroidogenic genes. The transcripts of several ovarian steroidogenic genes were more sensitive to 15 mu g/L BPA than that at other two levels. These findings suggest that EE2 could impair gonadal steroidogenesis by suppressing mRNA expression of steroidogenic genes and BPA could cause variations in gonadal steroidogenesis modulation with a potential consequence of compensation for the disturbance. (c) 2012 Elsevier B.V. All rights reserved.

Endocrine-disrupting chemicals (EDCs) can affect normal sexual differentiation in fish. Foxl2, one forkhead transcription factor, plays an important role in ovarian differentiation in the early development of the female gonad in mammals and fish. How EDCs affect expression is little known. In this study, we isolated a cDNA from the ovary of rare minnow and examined its expression during early development stages and in different adult tissues. Then, we analyzed expression in juvenile following 3-day exposure to 17 alpha- ethinylestradiol (EE2), 4-n-nonylphenol (NP), and bisphenol A (BPA). Alignment of known Foxl2 sequences among vertebrates showed high identity in forkhead domain and C-terminal region with other vertebrate proteins. Quantitative RT-PCR analysis showed that expression was linear decrease and , the downstream target gene of , had no correlation with from 18 to 50 days post fertilization (dpf). Among different adult tissues, is mainly expressed in ovary, brain, gill, eye, and male spleen. In the 3-day exposure, the juvenile fish to EDCs, 0.1 nM EE2, and 1 nM BPA significantly up-regulated the expression of gene, while NP had no effect on expression. Altogether, these results provide basic data for further study on how mediates EDCs impact on the sexual differentiation in .

To elucidate the effects of endocrine disrupting chemicals (EDCs) on aromatase, the rare minnow ovarian and brain P450 aromatase (cyp19a1a and cyp19a1b) cDNA and their 5'-flanking regions were isolated and characterized. RT-PCR analysis revealed that the rare minnow cyp19a1a mRNA was predominantly expressed in ovary while cyp19a1b was predominantly expressed in brain. Sequences for binding sites of steroidogenic factor-1, peroxisome proliferators-activated receptor, aryl hydrocarbon receptor. CCAAT/enhancer binding protein, estrogen responsive element, glucocorticoid responsive element, and retinoic acid receptor were identified on promoter regions of cyp19a1 genes. The influence of several EDCs on the transcript abundance of cyp19a1a and cyp19a1b was investigated in rare minnow juveniles. Clofibrate did not influence the expression of either cyp19a1 genes. Exposure to 1 nM ethinylestradiol (EE2) for 3 days significantly downregulated the expression of cyp19a1a gene, however 0.1 and 1 nM EE2 significantly increased the gene expression of cyp19a1b. Exposure to 100 and 1000 nM 4-nonylphenol (NP) significantly suppressed the cyp19a1a expression, but it had no effect on the expression of cyp19a1b gene. Bisphenol A (BPA) strongly suppressed the cyp19a1b gene expression from 0.1 to 10 nM and significantly suppressed the gene expression of cyp19a1a only at 10 nM. These results indicate that EDCs may influence the expression of cyp19a1 genes through differential transcriptional modulation in rare minnow juveniles. (C) 2010 Elsevier Inc. All rights reserved.

Zona pellucida (ZP) containing proteins are glycoproteins in teleost chorion and are encoded by several gene subfamilies, mainly including ZPA, ZPB, ZPC and ZPX genes. In teleost species, ZP genes are expressed either in liver under regulation of estrogen or in ovary. In the present study, five ZP gene isoforms were isolated and characterized in Gobiocypris rarus. The putative amino acid sequences of these ZP gene isoforms contain the typical trefoil motif and a ZP domain. These five G. rarus ZP gene isoforms were named as grZPB.1, grZPB.2, grZPB.3, grZPB.4 and grZPB.5. Real-time quantitative reverse transcription PCR (RT-qPCR) analysis indicated that all these ZP mRNA isoforms were exclusively expressed in ovary. G. rams juveniles at the age of 21 days postfertilization were exposed to 17 alpha-ethinylestradiol (EE2; 0.01, 0.1 and 1 nM), 4-nonylphenol (4-NP; 10, 100 and 1000 nM) or bisphenol A (BPA; 0.1, 1 and 10 nM) for 3 days. mRNA expressions of ZPB isoforms following the exposure to xenoestrogen were detected by RT-qPCR. Data were analyzed by the 2(-Delta Delta Cq) method. The results indicate that induction by 0.1-1 nM EE2 on mRNA expression of the grZPB isoforms is weaker than for vitellogenin. 4-NP exposures at three concentrations had differential effects on the grZPBs. BPA at three concentrations weakly induced mRNA expression of the grZPB isoforms. (C) 2011 Elsevier Inc. All rights reserved.

Recent studies support the notion that endocrine disrupting chemicals (EDCs) could affect the reproductive regulations of the neuroendocrine system. The objectives of the present study were to determine whether the weak estrogenic chemical, bisphenol A (BPA), disrupts gonadotropin-releasing hormone (GnRH) system by altering the transcription of GnRHs and GnRH receptor (GnRHR) genes in adult rare minnow Gobiocypris rarus. In the present study, the histological examination of the ovary after 35-day BPA exposure at 15 mu g/L demonstrated the perturbing effects of environmentally relevant BPA on the ovarian development in G. rams. In addition mRNA expression of ovarian P450 aromatase in both ovaries and testes were significantly down-regulated by 15 mu g/L BPA. GnRH2, GnRH3, GnRHR1A and GnRHR1B gene were identified in G. rarus. The expression patterns of GnRHs and GnRHR1s were analyzed in various tissues of G. rarus by quantitative real-time PCR. GnRHs and GnRHR1s were all predominantly expressed in the brains. Both GnRH3 and GnRHR1A were significantly upregulated in the brains of female exposed to 15 mu g/L BPA for 35 days. It would suggest a potential negative feedback in the GnRH system in response to the disturbance of down-stream of the brain-pituitary-gonadal axis. Collectively, the present findings suggest that the transcripts of some key genes in the neuroendocrine system can be used as critical biomarkers in endocrine disruption assays of teleost fish. (c) 2012 Elsevier Inc All rights reserved.

The full-length cDNAs for estrogen receptor 1 (esr1), esr2a and esr2b were isolated and characterized from the loach (Paramisgurnus dabryanus, Cobitidae, cypriniformes). P. dabryanus Esr1, Esr2a and Esr2b share high amino acids identities with their counterparts of cyprinid species. Quantitative real-time PCR (qRT-PCR) was used to analyze the tissue distribution of esr mRNAs in one-year-old P. dabryanus. The mRNA expression of esr1 in female liver was extremely higher than that in other tissues. esr2a mRNA expression in female intestine and in male muscle was higher than that in other tissues. esr2b mRNA expression was the highest in both male and female intestine. Two-month-old P. dabryanus were exposed to 17 alpha-ethinylestradiol (EE2) for 3 weeks and the changes of esr mRNA expression in brain, gonad and liver were analyzed by qRT-PCR. Results showed that EE2 at 1, 5 and 25 ng/L significantly suppressed testicular esr1 mRNA expression in male. The ovarian esr2a mRNA expression was significantly up-regulated at 1 ng/L EE2. In female brain, esr1 mRNA expression was significantly down-regulated at 5 ng/L EE2. Both in males and females, EE2 exposure increased the hepatic esr1 mRNA expression in a concentration-dependent manner. The present study suggests that different esrs in different tissues have differential responsiveness to EE2 and the hepatic esr1 is a sensitive biomarker to EE2 at environmental concentrations in P. dabryanus juveniles. So, the loach P. dabryanus, a typical demersal fish, is a promising ecological model organism to detect estrogenic chemicals in the sediment of aquatic environment by using molecular biomarkers. (C) 2012 Elsevier Inc. All rights reserved.

Pengze crucian carp (Carassius auratus var. pengze, Pcc), a triploid gynogenetic fish, was used in this study to investigate the cross-talk between EDCs and steroid receptors. The full-length cDNAs of five steroid receptors (esr1, er alpha2, esr2a, esr2b, ar) and partial cDNA of vtg B were isolated. The tissue distributions of these genes were analyzed in adult fish by qRT-PCR. Then the expression profiles of five steroid receptors (esrs and ar) and vtg B were detected in the juveniles exposed to 17alpha-ethinylestradiol (EE2, 0.1, 1 and 10ng/L) and 17alpha-methyltestosterone (MT, 50mug/L) for 4weeks. The results demonstrated that esrs, ar, and vtg B were predominantly expressed in liver of adult fish. However, among these detected genes, esr1 and er alpha2 mRNAs are sensitive biomarkers in response to EE2 at 0.1, 1, and 10ng/L for 1 and 2weeks compared to esr2a, esr2b, ar, and vtg B in the juveniles of mono-female gynogenetic fish. Totally, the subtypes of esrs show biphasic responses to EE2 exposures for 4weeks, and most of the EE2 exposures at 0.1, 1, and 10ng/L for 1, 2, 3 and 4weeks did not induce the mRNA expressions of vtg B. However, 1-, 2-, and 4-week 50mug/L MT all significantly stimulated vtg B transcripts. Further investigations are needed to elucidate the mechanism underlying the insensitivity or down-regulation of vtg B mRNA in response to EE2 in juvenile Pcc. Copyright =C2=A9 2013 Elsevier Inc. All rights reserved.