| 1. |
- Abdolahpur Monikh, Fazel, et al.
(författare)
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Parental and trophic transfer of nanoscale plastic debris in an assembled aquatic food chain as a function of particle size
- 2021
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Ingår i: Environmental Pollution. - : Springer. - 0269-7491 .- 1873-6424. ; 269
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Tidskriftsartikel (refereegranskat)abstract
- The existing limitations in analytical techniques for characterization and quantification of nanoscale plastic debris (NPD) in organisms hinder understanding of the parental and trophic transfer of NPD in organisms. Herein, we used iron oxide-doped polystyrene (PS) NPD (Fe-PS-NPD) of 270 nm and Europium (Eu)-doped PS-NPD (Eu-PS-NPD) of 640 nm to circumvent these limitations and to evaluate the influence of particle size on the trophic transfer of NPD along an algae-daphnids food chain and on the reproduction of daphnids fed with NPD-exposed algae. We used Fe and Eu as proxies for the Fe-PS-NPD and Eu-Ps-NPD, respectively. The algae cells (Pseudokirchinella subcapitata) were exposed to 4.8 × 1010 particles/L of Fe-PS-NPD or Eu-PS-NPD for 72 h. A high percentage (>60%) of the NPD was associated with algal cells. Only a small fraction (<11%) of the NPD, however, was transferred to daphnids fed for 21 days on the NPD-exposed algae. The uptake and trophic transfer of the 270 nm Fe-PS-NPD were higher than those for the 640 nm Eu-PS-NPD, indicating that smaller NPD are more likely to transfer along food chains. After exposure to Fe-PS-NPD, the time to first brood was prolonged and the number of neonates per adult significantly decreased compared to the control without any exposure and compared to daphnids exposed to the Eu-Ps-NPD. The offspring of daphnids exposed to Eu-PS-NPD through algae, showed a traceable concentration of Eu, suggesting that NPD are transferred from parents to offspring. We conclude that NPD can be transferred in food chains and caused reproductive toxicity as a function of NPD size. Studies with prolonged exposure and weathered NPD are endeavored to increase environmental realism of the impacts determined.
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| 2. |
- Chupani, Latifeh, et al.
(författare)
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Water Hardness Alters the Gene Expression Response and Copper Toxicity in Daphnia magna
- 2022
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Ingår i: Fishes. - : MDPI. - 2410-3888. ; 7:5
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Tidskriftsartikel (refereegranskat)abstract
- The influence of water hardness on copper (Cu) toxicity in Daphnia magna was studied using gene expression analysis. Exposing D. magna to Cu in water with increasing levels of hardness decreased the acute toxicity. Hardness did not affect the predicted Cu complexation. After 24 h, D. magna showed an increased level of genes related to metal homeostasis (mt) following exposure to 25 mu g Cu/L in hard water. Daphnids in soft and medium water responded to 25 mu g Cu/L by upregulation of antioxidant defense and mt genes, revealing oxidative stress as a mechanism of Cu toxicity in D. magna. D. magna exposed to 25 mu g Cu/L in soft water did not survive for 96 h. In contrast, those exposed to 25 mu g Cu/L in medium and hard water survived for 96 h with significantly higher levels of mt genes. The genes related to oxidative damage (heat shock protein and glutathione S-transferase) in these groups did not deviate from control levels, indicating the protective effect of hardness. Metallothionein genes were upregulated at 17 mu g Cu/L at both 24 h and 96 h. The expression of catalase and ferritin increased in this group in soft and hard water at 96 h. The protective effect of hardness (in the tested range) on survival was also observed at a concentration of 25 mu g/L. The results suggest metallothionein (A and B), catalase, and ferritin genes, as potential biomarkers for copper exposure in D. magna regardless of hardness.
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| 3. |
- Monikh, Fazel Abdolahpur, et al.
(författare)
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Engineered nanoselenium supplemented fish diet : toxicity comparison with ionic selenium and stability against particle dissolution, aggregation and release
- 2020
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Ingår i: Environmental Science: Nano. - : Royal Society of Chemistry. - 2051-8153 .- 2051-8161. ; 7:8, s. 2325-2336
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Tidskriftsartikel (refereegranskat)abstract
- Transformation of nutrients to their nano-form, such as selenium (Se) engineered nanonutrients (Se-ENNs), is expected to enhance the absorption of the nutrients into fish and increase the efficiency of the feed. However, dissolution, aggregation, and release of ENNs from the feed matrix may decrease the efficiency of the Se-ENNs. In this study, we provided fish feed supplemented with Se-ENNs which do not aggregate or dissolve and the particles are also not released from the feed matrix. As a proof of principle, we compared the toxicity of a diet containing Se-ENNs of two different sizes (60 nm and 120 nm) with diets containing ionic Se. The adverse effects were measured by monitoring the survival rate, acetylcholinesterase (AChE) levels and swimming behavior of zebrafish over 21 days of feeding with either the Se-ENNs or ionic Se supplemented fish diets. The number size distribution of the 60 nm Se-ENNs in the diet was similar to that in MilliQ water, while the size distribution of the 120 nm Se-ENNs in the diet was slightly wider. Ion and particle release from Se-ENNs containing diets in the exposure media was not observed, indicating the stability of the particles in the feed matrices. To determine toxicity, zebrafish (Danio rerio) were nourished using a control diet (without Se and Se-ENNs), Se (sodium selenite) containing diets (with 2.4 or 240 mg Se per kg feed) and Se-ENNs containing diets (with 2.4 or 240 mg Se-ENNs of 60 or 120 nm per kg feed) for 21 days. Both sizes of Se-ENNs were taken up in the fish, however only the 120 nm Se-ENNs were detected in the brains of fish. Zebrafish fed with Se-ENNs supplemented diets (60 and 120 nm) showed normal swimming behavior compared to the control. No significant alteration was determined in the AChE activity of the fish fed with the Se-ENNs supplemented diet. In contrast, feeding the zebrafish with a diet containing 240 mg kg(-1)Se led to lethal effects. These observations clearly depict the potential benefits of using Se-ENNs as nutrients in fish feed.
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| 4. |
- Niksirat, Hamid, et al.
(författare)
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Quantification of egg proteome changes during fertilization in sterlet Acipenser ruthenus
- 2017
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Ingår i: Biochemical and Biophysical Research Communications. - : Elsevier BV. - 0006-291X. ; 490:2, s. 189-193
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Tidskriftsartikel (refereegranskat)abstract
- Eggs of sterlet are discharged outside into ambient aquatic environment where egg activation and fertilization occur. Effects of different activation media including freshwater and clay suspension on protein abundances of egg were quantified in sterlet Acipenser ruthenus. In-gel digestion and high resolution mass spectrometry were used for label-free protein quantification in the eggs of five females. No significant (p > 0.05) difference was found between protein abundances in eggs activated with different media. However, results showed significant (p < 0.05, fold change ≥2) reduction in the abundances of nine proteins including six glycoproteins, enolase and heat shock protein in activated groups compared to freshly ovulated eggs as control. The fact that abundance of proteasome subunit alpha significantly reduced only in eggs which were activated by clay suspension suggests that activation medium can somehow intervene with protein regulation during fertilization. In conclusion, external fertilization in sturgeon egg is accompanied by huge release of proteins into the external environment that may participate in the construction of a transient microenvironment around egg for attraction and protection of spermatozoa to ensure ensuing fertilization. Data are available via ProteomeXchange with identifier PXD006232.
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