The Experts below are selected from a list of 1761 Experts worldwide ranked by ideXlab platform
Peiyuan Qian - One of the best experts on this subject based on the ideXlab platform.
-
optimization of Antifouling coatings incorporating butenolide a potent Antifouling Agent via field and laboratory tests
Progress in Organic Coatings, 2017Co-Authors: Lianguo Chen, Peiyuan QianAbstract:Rosin-based Antifouling paint with the incorporation of butenolide, a promising antifoulant, possesses the potential to deter the settlement of marine organisms on submerged surfaces. With the purpose to extend the Antifouling duration, this research investigated the respective contribution of paint ingredients, including butenolide concentrations (5%, 10% and 15%), pigment choices (TiO2, Fe2O3, Cu2O and ZnO) and binder compositions (acrylic copolymer to rosin at 1: 2.5, 1.5: 2 and 2.5: 1), to the field Antifouling performance of butenolide. A raft trial was carried out at Yung Shue 0, Hong Kong after the application of Antifouling paints on PVC panels. Biofouling dynamics on panel surfaces, such as coverage percentage and biomass accumulation, were monitored until submersion for 6 months to allow for the assessment of Antifouling efficiency. Field results showed that butenolide incorporation generally inhibited the settlement of fouling species on the coated panels as demonstrated by the decreased surface coverage and biomass weight. Coatings with 1: 2.5 paints containing 10% butenolide exhibited the best Antifouling performance with only 34% of the surface covered by fouling organisms, which mainly consisted of algae and slime. The smallest biomass increase of the fouling community was also observed for 1: 2.5 coatings. An increased proportion of rosin in binder compositions yielded better Antifouling performance following the order of 1: 2.5 > 1.5: 2 > 2.5: 1. Laboratory experiments were also conducted to examine the behavior of paint coatings in stirring artificial seawater. Butenolide addition decreased the film hardness and inhibited water uptake, but resulted in weight loss of paint coatings. Along with the gradual release of butenolide, the hardness of paint films increased gradually. Overall, a service life of 6 months, while eliminating the use of heavy metals, highlights the effectiveness of butenolide-incorporated paint formulation, especially 1: 2.5 paint, as an environmentally benign and fouling-resistant candidate for future Antifouling application.
-
linking genomic responses of gonads with reproductive impairment in marine medaka oryzias melastigma exposed chronically to the chemopreventive and Antifouling Agent 3 3 diindolylmethane dim
Aquatic Toxicology, 2017Co-Authors: Lianguo Chen, Doris W T Au, Chenyan Hu, Weipeng Zhang, B Zhou, John P Giesy, Peiyuan QianAbstract:3,3'-Diindolylmethane (DIM) has been promoted as an effective chemopreventive and Antifouling additive. However, the concurrent risks or side effects of DIM are not fully understood, especially on tissues responsive to estrogen. Therefore, this study employed marine medaka (Oryzias melastigma) as a test model to evaluate relative safety and explore mechanisms of toxic action of DIM on development and function of gonad after chronic (28days) aqueous exposure to relatively low doses (0μg/L or 8.5μg/L). Integration of comprehensive toxicogenomic analysis at the transcriptome and proteome levels with apical endpoints, such as production of eggs and swimming performance of larvae, elucidated the molecular linkage in gonad from bottom up along the reproductive adverse outcome pathway. A series of sequential changes at the transcript and protein levels were linked to lesser fecundity and viability of larvae exposed to DIM. Anomalous production of vitellogenin (VTG) and eggshell proteins in testis confirmed the estrogenic potency of DIM. In the ovary, although storage of VTG was greater, lesser expressions of cathepsin enzymes blocked cleavage and incorporation of VTG into oocytes as yolk, which acted together with lower eggshell proteins to inhibit maturation of primary oocyte and thus contributed to impairment of fecundity. Overall, this study demonstrated that exposure to DIM impaired reproductive fitness. Diverse molecular initiating changes in gonads were linked to apical endpoints that could be used in assessment of risks posed by DIM on gametogenesis. In combination with chemical stability and potent endocrine disruption, the results of this study can inform decisions about the use of DIM either as chemopreventive or Antifouling Agent.
-
degradation kinetics of a potent Antifouling Agent butenolide under various environmental conditions
Chemosphere, 2015Co-Authors: Lianguo Chen, Ying Xu, Wenxiong Wang, Peiyuan QianAbstract:Abstract Here, we investigated the degradation kinetics of butenolide, a promising Antifouling compound, under various environmental conditions. The active ingredient of the commercial antifoulant SeaNine 211, 4,5-dichloro-2-n-octyl-4-isothiazolin-3-one (DCOIT), was used as positive control. The results showed that the degradation rate increased with increasing temperature. Half-lives of butenolide at 4 °C, 25 °C and 40 °C were >64 d, 30.5 d and 3.9 d, respectively. Similar half-lives were recorded for DCOIT: >64 d at 4 °C, 27.9 d at 25 °C and 4.5 d at 40 °C. Exposure to sunlight accelerated the degradation of both butenolide and DCOIT. The photolysis half-lives of butenolide and DCOIT were 5.7 d and 6.8 d, respectively, compared with 9.7 d and 14.4 d for the dark control. Biodegradation led to the fastest rate of butenolide removal from natural seawater, with a half-life of 0.5 d, while no obvious degradation was observed for DCOIT after incubation for 4 d. The biodegradative ability of natural seawater for butenolide was attributed mainly to marine bacteria. During the degradation of butenolide and DCOIT, a gradual decrease in Antifouling activity was observed, as indicated by the increased settlement percentage of cypris larvae from barnacle Balanus amphitrite . Besides, increased cell growth of marine diatom Skeletonema costatum demonstrated that the toxicity of seawater decreased gradually without generation of more toxic by-products. Overall, rapid degradation of butenolide in natural seawater supported its claim as a promising candidate for commercial Antifouling industry.
-
changes in the proteome and phosphoproteome expression in the bryozoan bugula neritina larvae in response to the Antifouling Agent butenolide
Proteomics, 2010Co-Authors: Peiyuan Qian, Yung Hou Wong, Yu ZhangAbstract:Larval attachment and metamorphosis, commonly referred to as larval settlement, of marine sessile invertebrates can be triggered or blocked by chemical cues and affected by changes in overall protein expression pattern and phosphorylation dynamics. This study focuses on the effects of butenolide, an effective larval settlement inhibitor, on larval settlement at the proteome level in the bryozoan Bugula neritina. Liquid-phase IEF sample prefractionation combined with 2-DE and MALDI-TOF MS was used to identify the differentially expressed proteins. Substantial changes occurred both in protein abundance and in phosphorylation status during larval settlement and when settling larvae were challenged with butenolide. The proteins that responded to treatment were identified as structural proteins, molecular chaperones, mitochondrial peptidases and calcium-binding proteins. Compared with our earlier results, both genistein and butenolide inhibited larval settlement of B. neritina primarily by changes in protein abundance and the phosphorylation status of proteins but have different protein targets in the same species. Clearly, to design potent Antifouling compounds and to understand the mode of action of compounds, more studies on the effects of different compounds on proteome and phosphoproteome of different larval species are required.
-
comparative proteome and phosphoproteome analyses during cyprid development of the barnacle balanus amphibalanus amphitrite
Journal of Proteome Research, 2010Co-Authors: Yu Zhang, Ying Xu, Shawn M Arellano, Kang Xiao, Peiyuan QianAbstract:The barnacle Balanus amphitrite ()Amphibalanus amphitrite) is a major marine biofouling invertebrate worldwide. It has a complex life cycle during which the larva (called a nauplius) molts six times before transforming into the cyprid stage. The cyprid stage in B. amphitrite is the critical stage for the larval decision to attach and metamorphose. In this study, proteome and phosphoproteome alterations during cyprid development/aging and upon treatment with the Antifouling Agent butenolide were examined with a two-dimensional electrophoresis (2-DE) multiplexed fluorescent staining approach. Optimized protein separation strategies, including solution-phase isoelectric fractionation and narrow-pH-range 2-DE, were used in a proteomic analysis. Our results show that the differential regulation of the target proteins is highly dynamic on the levels of both protein expression and posttranslational modification. Two groups of proteins, stress-associated and energy metabolism-related proteins, are differentially expressed during cyprid development. Comparison of the control and treatment groups suggests that butenolide exerts its effects by sustaining the expression levels of these proteins. Altogether, our data suggest that proteins involved in stress regulation and energy metabolism play crucial roles in regulating larval attachment and metamorphosis of B. amphitrite.
Magnus Nyden - One of the best experts on this subject based on the ideXlab platform.
-
Imidazole and Triazole Coordination Chemistry for Antifouling Coatings
Journal of Chemistry, 2013Co-Authors: Markus Andersson Trojer, Hans Blanck, Alireza Movahedi, Magnus NydenAbstract:Fouling of marine organisms on the hulls of ships is a severe problem for the shipping industry. Many Antifouling Agents are based on five-membered nitrogen heterocyclic compounds, in particular imidazoles and triazoles. Moreover, imidazole and triazoles are strong ligands for Cu2+ and Cu+, which are both potent Antifouling Agents. In this review, we summarize a decade of work within our groups concerning imidazole and triazole coordination chemistry for Antifouling applications with a particular focus on the very potent Antifouling Agent medetomidine. The entry starts by providing a detailed theoretical description of the azole-metal coordination chemistry. Some attention will be given to ways to functionalize polymers with azole ligands. Then, the effect of metal coordination in azole-containing polymers with respect to material properties will be discussed. Our work concerning the controlled release of Antifouling Agents, in particular medetomidine, using azole coordination chemistry will be reviewed. Finally, an outlook will be given describing the potential for tailoring the azole ligand chemistry in polymers with respect to Cu2+ adsorption and Cu2+ Cu+ reduction for Antifouling coatings without added biocides.
-
Antifouling Agent Release from Marine Coatings - Ion Pair Formation/Dissolution for Controlled Release
Progress in Organic Coatings, 2006Co-Authors: Paul Handa, Camilla Fant, Magnus NydenAbstract:In marine coatings, the ability to sustain constant release of Antifouling Agents (AFA(s)) over a long period of time has become increasingly important. One efficient approach to prevent that diffusion depletes the paint film's Antifouling activity is to adsorb the AFA strongly to a specie with low translational mobility, such as a high molecular weight polymer. Therefore, the AFA, Medetomidine, was adsorbed onto a sulfonated polystyrene-block-poly(ethylene-ran-butylene)-block-polystyrene (SDPS) generating a Medetomidine-SDPS ion pair in an organic solvent. The interaction was investigated by 1 H NMR in butanol (BuOH-d 10 ) and on solid surfaces by the quartz crystal microbalance with dissipation monitoring technique (QCM-D) in two different solvents, seawater and o-xylene. From the NMR studies in butanol (BuOH-d 10 ), a strong interaction between Medetomidine and SDPS was observed. From the QCM-D measurements, differences in affinity between Medetomidine and the SDPS was observed when changing from seawater to o-xylene. In seawater, the interaction was weak and displayed a large degree of reversibility compared to in o-xylene, where the interaction was strong and almost irreversible. Different swelling behaviour was also observed at the solid surfaces depending on the solvent used with o-xylene exhibiting the largest swelling of the polymer layer. © 2006 Elsevier B.V. All rights reserved.
-
Antifouling Agent release from marine coatings ion pair formation dissolution for controlled release
Progress in Organic Coatings, 2006Co-Authors: Paul Handa, Camilla Fant, Magnus NydenAbstract:In marine coatings, the ability to sustain constant release of Antifouling Agents (AFA(s)) over a long period of time has become increasingly important. One efficient approach to prevent that diffusion depletes the paint film's Antifouling activity is to adsorb the AFA strongly to a specie with low translational mobility, such as a high molecular weight polymer. Therefore, the AFA, Medetomidine, was adsorbed onto a sulfonated polystyrene-block-poly(ethylene-ran-butylene)-block-polystyrene (SDPS) generating a Medetomidine-SDPS ion pair in an organic solvent. The interaction was investigated by 1 H NMR in butanol (BuOH-d 10 ) and on solid surfaces by the quartz crystal microbalance with dissipation monitoring technique (QCM-D) in two different solvents, seawater and o-xylene. From the NMR studies in butanol (BuOH-d 10 ), a strong interaction between Medetomidine and SDPS was observed. From the QCM-D measurements, differences in affinity between Medetomidine and the SDPS was observed when changing from seawater to o-xylene. In seawater, the interaction was weak and displayed a large degree of reversibility compared to in o-xylene, where the interaction was strong and almost irreversible. Different swelling behaviour was also observed at the solid surfaces depending on the solvent used with o-xylene exhibiting the largest swelling of the polymer layer. © 2006 Elsevier B.V. All rights reserved.
-
nmr diffusometry and ftir in the study of the interaction between Antifouling Agent and binder in marine paints
Progress in Organic Coatings, 2004Co-Authors: Liubov Shtykova, Denis Ostrovskii, Paul Handa, Krister Holmberg, Magnus NydenAbstract:Abstract The interaction between an Antifouling Agent and binder in a model marine paint system has been thoroughly studied by NMR and FTIR techniques. NMR diffusometry was used to quantify the strength of binder–Antifouling Agent interaction and FTIR spectroscopy to study the mechanism of binding. Medetomidine was the Antifouling Agent and a long-chain alkyd resin was chosen as a binder. The diffusion coefficient of medetomidine indicates a strong interaction with alkyd in xylene. The amount of adsorbed Antifouling Agent has a threshold value, which is determined by the number of available active sites on the binder. As shown by FTIR such sites are predominantly carboxyl groups, although interaction with other sites is also possible.
Francesca Cappitelli - One of the best experts on this subject based on the ideXlab platform.
-
altered expression level of escherichia coli proteins in response to treatment with the Antifouling Agent zosteric acid sodium salt
Environmental Microbiology, 2012Co-Authors: Federica Villa, William Remelli, Fabio Forlani, Alberto Vitali, Francesca CappitelliAbstract:Summary Zosteric acid sodium salt is a powerful Antifouling Agent. However, the mode of its Antifouling action has not yet been fully elucidated. Whole cell proteome of Escherichia coli was analysed to study the different protein patterns expressed by the surface-exposed planktonic cells without and with sublethal concentrations of the zosteric acid sodium salt. Proteomic analysis revealed that at least 27 proteins showed a significant (19 upregulated and 8 downregulated, P < 0.001) altered expression level in response to the antifoulant. The proteomic signatures of zosteric acid sodium salt-treated cells are characterized by stress-associated (e.g. AhpC, OsmC, SodB, GroES, IscU, DnaK), motility-related (FliC), quorum-sensing-associated (LuxS) and metabolism/biosynthesis-related (e.g. PptA, AroA, FabD, FabB, GapA) proteins. Consistent with the overexpression of LuxS enzyme, the Antifouling Agent increased autoinducer-2 (AI-2) concentration by twofold. Moreover, treated cells experienced a statistically significant but modest increase of reactive oxygen species (+ 23%), tryptophanase (1.2-fold) and indole (1.2-fold) synthesis. Overall, our data suggest that zosteric acid sodium salt acts as environmental cue leading to global stress on E. coli cells, which favours the expression of various protective proteins, the AI-2 production and the synthesis of flagella, to escape from adverse conditions.
-
Altered expression level of Escherichia coli proteins in response to treatment with the Antifouling Agent zosteric acid sodium salt
Environmental Microbiology, 2011Co-Authors: Federica Villa, William Remelli, Fabio Forlani, Alberto Vitali, Francesca CappitelliAbstract:Summary Zosteric acid sodium salt is a powerful Antifouling Agent. However, the mode of its Antifouling action has not yet been fully elucidated. Whole cell proteome of Escherichia coli was analysed to study the different protein patterns expressed by the surface-exposed planktonic cells without and with sublethal concentrations of the zosteric acid sodium salt. Proteomic analysis revealed that at least 27 proteins showed a significant (19 upregulated and 8 downregulated, P
Hideo Okamura - One of the best experts on this subject based on the ideXlab platform.
-
Degradation of triphenylborane-pyridine Antifouling Agent in water by copper ions.
Environmental technology, 2020Co-Authors: Ai Tsuboi, Xiaojian Zhou, Hideo Okamura, Netnapit Kaewchuay, Keiichi Fukushi, Tomoaki NishidaAbstract:Triphenylborane-pyridine (TPBP) is an Antifouling compound used in Asian countries, including Japan, and its residue has not been detected in aquatic environments to date. There are limited data on its fate for environmental management. The purpose of this study was to evaluate whether TPBP is degraded by metal ions in aquatic environments. TPBP with metal ions in 20 mM sodium acetate buffer at pH 8.0 was placed at 25 degrees C in the dark for 24 h. The concentrations of TPBP and its degradation products, such as diphenylboronic acid, phenylboronic acid (MPB), phenol, benzene, biphenyl, and boron were determined. The presence of copper ions (50 mg/l), but not zinc or manganese ions, resulted in complete degradation of TPBP in 24 h. The TPBP degradation was much faster than the boron production in the initial reaction (0-1 h) with copper salts, depending on the copper salts tested. TPBP was degraded by copper ions (5 mg/l) in 24 h, producing phenol, MPB, biphenyl, and borate. Cu2+ as copper(II) chloride or copper(II) acetate led to complete degradation of TPBP, and thylenediaminetetraacetic acid disodium salt addition suppressed the TPBP degradation. Cu+ as copper(I) acetate also completely degraded TPBP, and bathocuproine addition suppressed the TPBP degradation. This suggests that copper ions existing in natural environments might degrade TPBP released from Antifouling paint into water, and this could be one of the important mechanisms to dissipate TPBP residues in aquatic environments.
-
Degradation of triphenylborane–pyridine Antifouling Agent in water by copper ions
Environmental Technology, 2013Co-Authors: Ai Tsuboi, Xiaojian Zhou, Hideo Okamura, Netnapit Kaewchuay, Keiichi Fukushi, Tomoaki NishidaAbstract:Triphenylborane–pyridine (TPBP) is an Antifouling compound used in Asian countries, including Japan, and its residue has not been detected in aquatic environments to date. There are limited data on its fate for environmental management. The purpose of this study was to evaluate whether TPBP is degraded by metal ions in aquatic environments. TPBP with metal ions in 20 mM sodium acetate buffer at pH 8.0 was placed at 25°C in the dark for 24 h. The concentrations of TPBP and its degradation products, such as diphenylboronic acid, phenylboronic acid (MPB), phenol, benzene, biphenyl, and boron were determined. The presence of copper ions (50 mg/l), but not zinc or manganese ions, resulted in complete degradation of TPBP in 24 h. The TPBP degradation was much faster than the boron production in the initial reaction (0–1 h) with copper salts, depending on the copper salts tested. TPBP was degraded by copper ions (5 mg/l) in 24 h, producing phenol, MPB, biphenyl, and borate. Cu2+ as copper(II) chloride or copper(...
-
ecotoxicity of the degradation products of triphenylborane pyridine tpbp Antifouling Agent
Chemosphere, 2009Co-Authors: Hideo Okamura, Shota Kitano, Shinji Toyota, Hiroya Harino, Kevin V ThomasAbstract:Triphenylborane pyridine (TPBP) is an alternative to organotin Antifouling compounds. This work aimed to identify the unknown Peak #1, and to evaluate the ecotoxicity of TPBP and its degradation products. Peak #1 was produced from TPBP dissolved in acetonitrile under UV-A photolysis using a high-pressure mercury lamp. The Peak #1 fraction was purified using two-step column chromatography from a TPBP-acetonitrile solution. The major compound of the fraction was identified as being biphenyl from the 1H NMR and 13C NMR spectra. The ecotoxicity of four degradation products (diphenylborane hydroxide, phenylborane dihydroxide, phenol, and biphenyl) and TPBP towards two marine planktons were assessed. The 48 h LC(50) values of the crustacean, Artemia salina, were 0.13 mg L(-1) for TPBP, 14 mg L(-1) for biphenyl, 17 mg L(-1) for phenol, and > 50 mg L(-1) for the other degradation products. The 72 h EC(50) values of the diatom, Skeletonema costatum, were 0.0022 mg L(-1) for TPBP, 1.2 mg L(-1) for biphenyl, and > 2 mg L(-1) for the other degradation products. Thus, the ecotoxicity of biphenyl and the other degradation products were not high compared to the parent compound, TPBP.
-
abiotic degradation of triphenylborane pyridine tpbp Antifouling Agent in water
Chemosphere, 2007Co-Authors: Xiaojian Zhou, Hideo Okamura, Shinichi NagataAbstract:Abstract The abiotic degradation of the new Antifouling Agent, triphenylborane pyridine (TPBP), was investigated in buffer solutions having different pH values (pH 5, 7, and 9), and in artificial and natural seawater to estimate environmental fate of TPBP. The TPBP in these waters was decomposed by a seven-day hydrolysis process at 50 °C both in the dark and a photolysis process under UV-A irradiation using a high-pressure mercury lamp for periods up to 24 h. TPBP hydrolysis was significantly enhanced by acidic pH solutions. The photolysis rate of TPBP was higher in acidic pH solutions than in neutral or basic pH solutions, and was highest in natural seawater, which could have contained naturally dissolved organic matter. Two degradation products, phenol and an unknown substance (Peak #1), were observed during the hydrolysis and photolysis studies of TPBP. The concentration of these substances after a one-day photolysis treatment was higher than after a seven-day hydrolysis treatment. The degradation rate of TPBP in the five test water samples was related to the simultaneous photolysis formation of phenol and Peak #1. However, the degradation rate of TPBP was not related to the formation of the hydrolysis products. Therefore, it is suggested that photodegradation of TPBP follows a different pathway to the hydrolysis degradation of TPBP. Our results indicate the chemical and photochemical reaction of TPBP in water occurs in natural aquatic environments.
Lianguo Chen - One of the best experts on this subject based on the ideXlab platform.
-
optimization of Antifouling coatings incorporating butenolide a potent Antifouling Agent via field and laboratory tests
Progress in Organic Coatings, 2017Co-Authors: Lianguo Chen, Peiyuan QianAbstract:Rosin-based Antifouling paint with the incorporation of butenolide, a promising antifoulant, possesses the potential to deter the settlement of marine organisms on submerged surfaces. With the purpose to extend the Antifouling duration, this research investigated the respective contribution of paint ingredients, including butenolide concentrations (5%, 10% and 15%), pigment choices (TiO2, Fe2O3, Cu2O and ZnO) and binder compositions (acrylic copolymer to rosin at 1: 2.5, 1.5: 2 and 2.5: 1), to the field Antifouling performance of butenolide. A raft trial was carried out at Yung Shue 0, Hong Kong after the application of Antifouling paints on PVC panels. Biofouling dynamics on panel surfaces, such as coverage percentage and biomass accumulation, were monitored until submersion for 6 months to allow for the assessment of Antifouling efficiency. Field results showed that butenolide incorporation generally inhibited the settlement of fouling species on the coated panels as demonstrated by the decreased surface coverage and biomass weight. Coatings with 1: 2.5 paints containing 10% butenolide exhibited the best Antifouling performance with only 34% of the surface covered by fouling organisms, which mainly consisted of algae and slime. The smallest biomass increase of the fouling community was also observed for 1: 2.5 coatings. An increased proportion of rosin in binder compositions yielded better Antifouling performance following the order of 1: 2.5 > 1.5: 2 > 2.5: 1. Laboratory experiments were also conducted to examine the behavior of paint coatings in stirring artificial seawater. Butenolide addition decreased the film hardness and inhibited water uptake, but resulted in weight loss of paint coatings. Along with the gradual release of butenolide, the hardness of paint films increased gradually. Overall, a service life of 6 months, while eliminating the use of heavy metals, highlights the effectiveness of butenolide-incorporated paint formulation, especially 1: 2.5 paint, as an environmentally benign and fouling-resistant candidate for future Antifouling application.
-
linking genomic responses of gonads with reproductive impairment in marine medaka oryzias melastigma exposed chronically to the chemopreventive and Antifouling Agent 3 3 diindolylmethane dim
Aquatic Toxicology, 2017Co-Authors: Lianguo Chen, Doris W T Au, Chenyan Hu, Weipeng Zhang, B Zhou, John P Giesy, Peiyuan QianAbstract:3,3'-Diindolylmethane (DIM) has been promoted as an effective chemopreventive and Antifouling additive. However, the concurrent risks or side effects of DIM are not fully understood, especially on tissues responsive to estrogen. Therefore, this study employed marine medaka (Oryzias melastigma) as a test model to evaluate relative safety and explore mechanisms of toxic action of DIM on development and function of gonad after chronic (28days) aqueous exposure to relatively low doses (0μg/L or 8.5μg/L). Integration of comprehensive toxicogenomic analysis at the transcriptome and proteome levels with apical endpoints, such as production of eggs and swimming performance of larvae, elucidated the molecular linkage in gonad from bottom up along the reproductive adverse outcome pathway. A series of sequential changes at the transcript and protein levels were linked to lesser fecundity and viability of larvae exposed to DIM. Anomalous production of vitellogenin (VTG) and eggshell proteins in testis confirmed the estrogenic potency of DIM. In the ovary, although storage of VTG was greater, lesser expressions of cathepsin enzymes blocked cleavage and incorporation of VTG into oocytes as yolk, which acted together with lower eggshell proteins to inhibit maturation of primary oocyte and thus contributed to impairment of fecundity. Overall, this study demonstrated that exposure to DIM impaired reproductive fitness. Diverse molecular initiating changes in gonads were linked to apical endpoints that could be used in assessment of risks posed by DIM on gametogenesis. In combination with chemical stability and potent endocrine disruption, the results of this study can inform decisions about the use of DIM either as chemopreventive or Antifouling Agent.
-
degradation kinetics of a potent Antifouling Agent butenolide under various environmental conditions
Chemosphere, 2015Co-Authors: Lianguo Chen, Ying Xu, Wenxiong Wang, Peiyuan QianAbstract:Abstract Here, we investigated the degradation kinetics of butenolide, a promising Antifouling compound, under various environmental conditions. The active ingredient of the commercial antifoulant SeaNine 211, 4,5-dichloro-2-n-octyl-4-isothiazolin-3-one (DCOIT), was used as positive control. The results showed that the degradation rate increased with increasing temperature. Half-lives of butenolide at 4 °C, 25 °C and 40 °C were >64 d, 30.5 d and 3.9 d, respectively. Similar half-lives were recorded for DCOIT: >64 d at 4 °C, 27.9 d at 25 °C and 4.5 d at 40 °C. Exposure to sunlight accelerated the degradation of both butenolide and DCOIT. The photolysis half-lives of butenolide and DCOIT were 5.7 d and 6.8 d, respectively, compared with 9.7 d and 14.4 d for the dark control. Biodegradation led to the fastest rate of butenolide removal from natural seawater, with a half-life of 0.5 d, while no obvious degradation was observed for DCOIT after incubation for 4 d. The biodegradative ability of natural seawater for butenolide was attributed mainly to marine bacteria. During the degradation of butenolide and DCOIT, a gradual decrease in Antifouling activity was observed, as indicated by the increased settlement percentage of cypris larvae from barnacle Balanus amphitrite . Besides, increased cell growth of marine diatom Skeletonema costatum demonstrated that the toxicity of seawater decreased gradually without generation of more toxic by-products. Overall, rapid degradation of butenolide in natural seawater supported its claim as a promising candidate for commercial Antifouling industry.