Impacts of pyraclostrobin on intestinal health and the intestinal microbiota in common carp (Cyprinus carpio L.).

Pyraclostrobin (PYR) is a strobilurin fungicide that is commonly used in agriculture, and its use in agriculture may lead to an increase in its residue in the aquatic environment and may have a deleterious influence on the intestinal health of aquatic creatures. Here, common carp were chronically exposed to PYR (0, 0.5, or 5.0 µg/L) for 30 d to determine its effect on the physical and immunological barrier and intestinal microbiota in the intestine. PYR exposure caused significant histological changes; altered the mRNA expression levels of occludin, claudin-2, and zonula occludens-1 (ZO-1); induced oxidative stress in the common carp intestine; and increased the serum D-lactate and diamine oxidase (DAO) levels. Moreover, PYR significantly increased the protein expression levels of tumour necrosis factor alpha (TNF-α), interleukin 1 beta (IL-1ß), and IL-6 while decreasing the level of transforming growth factor beta (TGF-ß). Further studies revealed that PYR significantly reduced lysozyme (LZM) and acid phosphatase (ACP) activities as well as complement 3 (C3) and immunoglobulin M (IgM) levels. Furthermore, PYR decreased gut microbial diversity while increasing the abundance of pathogenic bacteria such as Aeromonas and Shewanella, causing an intestinal microbial disturbances in common carp. These results imply that PYR has a negative impact on fish intestinal health and may pose serious health risks to fish by disrupting the intestinal microbiota, physical barrier, and immunological barrier in common carp.

Developmental Neurotoxicity of Trichlorfon in Zebrafish Larvae.

Trichlorfon is an organophosphorus pesticide widely used in aquaculture and has potential neurotoxicity, but the underlying mechanism remains unclear. In the present study, zebrafish embryos were exposed to trichlorfon at concentrations (0, 0.1, 2 and 5 mg/L) used in aquaculture from 2 to 144 h post fertilization. Trichlorfon exposure reduced the survival rate, hatching rate, heartbeat and body length and increased the malformation rate of zebrafish larvae. The locomotor activity of larvae was significantly reduced. The results of molecular docking revealed that trichlorfon could bind to acetylcholinesterase (AChE). Furthermore, trichlorfon significantly inhibited AChE activity, accompanied by decreased acetylcholine, dopamine and serotonin content in larvae. The transcription patterns of genes related to acetylcholine (e.g., ache, chrna7, chata, hact and vacht), dopamine (e.g., drd4a and drd4b) and serotonin systems (e.g., tph1, tph2, tphr, serta, sertb, htrlaa and htrlab) were consistent with the changes in acetylcholine, dopamine, serotonin content and AChE activity. The genes related to the central nervous system (CNS) (e.g., a1-tubulin, mbp, syn2a, shha and gap-43) were downregulated. Our results indicate that the developmental neurotoxicity of trichlorfon might be attributed to disorders of cholinergic, dopaminergic and serotonergic signaling and the development of the CNS.

A new insight into the polar lipid composition in mature breast milk and ewe milk with comparative lipidomics analysis.

Polar lipids play essential biological functions in energy storage, both as structural components of cell membranes and as signaling molecules. In this study, a comprehensive UHPLC-QTRAP-MS-based lipidomic analysis of mature breast milk (BM) and ewe milk (EM) was conducted. Through the analysis, a total of 362 polar lipid species from 14 subclasses were characterized, including 60 phosphatidylethanolamines (PEs), 59 phosphatidylcholines (PCs), 38 phosphatidylinositols (PIs), 35 sphingomyelins (SMs), and 34 ceramides (Cers). Of these, 139 lipid molecules were screened as significantly differentially expressed polar lipids (SDPLs) between the two kinds of milk based on the following criteria: a variable importance in projection (VIP) value > 1.0, a false discovery rate-adjusted P-value < 0.0001, and a fold change (FC) of either > 2.0 or < 0.5; these included 111 upregulated and 28 downregulated SDPLs in EM compared to BM. Among these SDPLs, the content of PE (16:1_18:0) was found to be significantly higher in EM compared to BM (FC = 69.5853, P < 0.0001). Moreover, sphingolipid metabolism and glycerophospholipid metabolism were determined to be vital metabolic pathways. This was derived from the finding that PE, PC, SM, and PI were key lipid metabolites in the two kinds of milk that were related to these two metabolic pathways. This study provides new insights into the characterization of SDPLs in mammalian milk, and also provides a theoretical basis for optimizing infant formula.

Hepatopancreas toxicity and immunotoxicity of a fungicide, pyraclostrobin, on common carp.

Pyraclostrobin (PYR), a strobilurin fungicide, has been widely used to control fungal diseases, posing potential risk to aquatic organisms. However, the toxic effects of PYR to fish remained largely unknown. In this study, common carp (Cyprinus carpio L.) was exposed to environmentally relevant levels of PYR (0, 0.5 and 5.0 µg/L) for 30 days to assess its chronic toxicity and potential toxicity mechanism. The results showed that long-term exposure to PYR induced hepatopancreas damage as evident by increased in serum transaminase activities (AST and ALT). Moreover, PYR exposure remarkably enhanced the expressions of hsp70 and hsp90, decreased the levels of antioxidant enzymes and biomarkers and promoted the reactive oxygen species (H2O2 and O2-) and MDA contents in carp hepatopancreas. PYR exposure also upregulated apoptosis-related genes (bax, apaf-1, caspase-3 and caspase-9) and reduced anti-apoptosis gene bcl-2 in fish hepatopancreas. Moreover, PYR exposure altered the expressions of inflammatory cytokines (IL-1ß, IL-6, TNF-α and TGF-ß) in the serum and hepatopancreas and the level of NF-κB p65 in the hepatopancreas. Further research indicated that PYR exposure markedly changed the levels of immune parameters (LYZ, C3, IgM, ACP and AKP) in the serum and/or hepatopancreas, indicating that chronic PYR exposure also has immunotoxicity on fish. Additionally, we found that PYR exposure upregulated p38 and jnk MAPK transcription levels, suggesting that MAPK may be play important role in PYR-induced apoptosis and inflammatory response in the hepatopancreas of common carp. In summary, PYR exposure induced oxidative stress, triggered apoptosis, inflammatory and immune response in common carp, which can help to elucidate the possible toxicity mechanism of PYR in fish.

Inhibition Effect of Ionic Liquid [Hmim]Cl on Microcystis Growth and Toxin Production.

Ionic liquids (ILs) are known as "green solvents" and widely used in industrial applications. However, little research has been conducted on cyanobacteria. This study was conducted to investigate the toxicity of ionic liquids ([Hmim]Cl) on Microcystis aeruginosa PCC7806. The EC50 (72 h) of [Hmim]Cl on the growth of Microcystis aeruginosa PCC 7806 was 10.624 ± 0.221 mg L-1. The possible mechanism of toxicity of [Hmim]Cl against M. aeruginosa PCC 7806 was evaluated by measuring cell growth, photosynthetic pigment contents, chlorophyll fluorescence transients, cell ultrastructure, and transcription of the microcystin-producing gene (mcyB). The concentrations of chlorophyll a and carotenoids were significantly reduced in treated M. aeruginosa cultures. The results of chlorophyll fluorescence transients showed that [Hmim]Cl could destruct the electron-accepting side of the photosystem II of M. aeruginosa PCC 7806. Transmission electron microscopy demonstrated cell damage including changes in the structure of the cell wall and cell membrane, thylakoid destruction, and nucleoid disassembly. The transcription of the mcyB gene was also inhibited under [Hmim]Cl stress. In summary, this study provides new insights into the toxicity of [Hmim]Cl on cyanobactreia.

Neurotoxicity of Chronic Co-Exposure of Lead and Ionic Liquid in Common Carp: Synergistic or Antagonistic?

Previous studies have indicated that the harmful heavy metal lead (Pb) contamination in aquatic systems has caused intelligence development disorders and nervous system function abnormalities in juveniles due to the increased permeability of the blood-brain barrier. Ionic liquids (ILs) are considered "green" organic solvents that can replace traditional organic solvents. Studies have found the presence of ILs in soil and water due to chemical applications or unintentional leakage. Therefore, what would happen if Pb interacted with ILs in a body of water? Could ILs enable Pb to more easily cross the blood-brain barrier? Therefore, we examined the combined exposure of Pb and ILs in common carp at low concentration (18.3 mg L-1 of Pb(CH3COO)2•3 H2O and 11 mg L-1 of the IL 1-methyl-3-octylimidazolium chloride, 5% of their LC50) for 28 days in the present study. The result of a neurobehavioral assay showed that chronic exposure of lead at lower concentrations significantly altered fish movement and neurobehaviors, indicating that lead exposure caused neurotoxicity in the carp. Increases in the neurotransmitter dopamine levels and injuries in the fish brain accounted for neurobehavioral abnormalities induced by lead exposure. Moreover, we also found that lead could easily cross the blood-brain barrier and caused significant bioaccumulation in the brain. Particularly, our study indicated that the ionic liquid could not synergistically promote blood-brain barrier permeability and hence failed to increase the absorption of lead in the fish brain, suggesting that the combined exposure of lead and ILs was not a synergistic effect but antagonism to the neurotoxicity. The results of this study suggested that ILs could recede the Pb induced neurotoxicity in fish.

Effects of polyvinyl chloride microplastics on reproduction, oxidative stress and reproduction and detoxification-related genes in Daphnia magna.

The drastic increase of microplastics (MPs) in aquatic environment has become a serious threat to marine and freshwater ecosystems. However, little information is available regarding the potential detrimental effects of polyvinyl chloride microplastics (PVC-MPs) on aquatic organisms. This study investigated the changes of reproduction parameters, oxidative stress and the expression of reproduction and detoxification-related genes in Daphnia magna after exposed to 2 ± 1 and 50 ± 10 µm PVC-MPs. The results showed that chronic exposure to 2 ± 1 µm PVC-MPs prolonged days to the first brood, increased total number of broods per female and frequency of molting per adult, decreased offspring number at first brood and total number of offspring per female in D. magna. Moreover, 2 ± 1 µm PVC-MPs also disturbed the activities of SOD and CAT, increased GSH and MDA levels. The expression of Vtg, SOD, CAT, CYP314 and CYP360A8 genes also exhibited different response patterns depending on exposure time. Furthermore, 50 ± 10 µm PVC-MPs decreased offspring at first brood and Vtg mRNA level, increased the transcription levels and activities of SOD and CAT. These results suggest that the presence of PVC-MPs in aquatic environment may cause reproduction toxicity by disrupting the reproduction and detoxification-related genes expression and inducing oxidative stress in D. magna.

Negative impacts of microcystin-LR and glyphosate on zebrafish intestine: Linked with gut microbiota and microRNAs?

Microcystin-LR (MC-LR) and glyphosate (GLY) have been classified as a Group 2B and Group 2A carcinogens for humans, respectively, and frequently found in aquatic ecosystems. However, data on the potential hazard of MC-LR and GLY exposure to the fish gut are relatively scarce. In the current study, a subacute toxicity test of zebrafish exposed to MC-LR (35 µg L-1) and GLY (3.5 mg L-1), either alone or in combination was performed for 21 d. The results showed that MC-LR or/and GLY treatment reduced the mRNA levels of tight junction genes (claudin-5, occludin, and zonula occludens-1) and altered the levels of diamine oxidase and D-lactic, indicating increased intestinal permeability in zebrafish. Furthermore, MC-LR and/or GLY treatment remarkably increased the levels of intestinal IL-1ß and IL-8 but decreased the levels of IL-10 and TGF-ß, indicating that MC-LR and/or GLY exposure induced an inflammatory response in the fish gut. MC-LR and/or GLY exposure also activated superoxide dismutase and catalase, generally upregulated the levels of p53, bax, bcl-2, caspase-3, and caspase-9, downregulated the levels of caspase-8 and caused notable histological injury in the fish gut. Moreover, MC-LR and/or GLY exposure also significantly altered the microbial community in the zebrafish gut and the expression of miRNAs (miR-146a, miR-155, miR-16, miR-21, and miR-223). Chronic exposure to MC-LR and/or GLY can induce intestinal damage in zebrafish, and this study is the first to demonstrate an altered gut microbiome and miRNAs in the zebrafish gut after MC-LR and GLY exposure.

The role of chest CT quantitative pulmonary inflammatory index in the evaluation of the course and treatment outcome of COVID-19 pneumonia.

To explore the clinical application value of chest CT quantitative pulmonary inflammation index (PII) in the evaluation of the course and treatment outcome of COVID-19 pneumonia. One hundred and eighteen patients with COVID-19 pneumonia diagnosed by RT-PCR were analyzed retrospectively. The correlation between chest CT PII, clinical symptoms and laboratory examinations during the entire hospitalization period was compared. The average age of the patients was 46.0 ± 15 (range: 1-74) years. Of the 118 patients, 62 are male (52.5%) and 56 are female (47.5%). Among them, 116 patients recovered and were discharged, 2 patients died, and the median length of hospital stay was 22 (range: 9-41) days. On admission, 76.3% of the patients presented with fever, and the laboratory studies showed a decrease in lymphocyte (LYM) count and an increase in lactate dehydrogenase (LDH) levels, C-reactive protein (CRP) levels, and erythrocyte sedimentation rate (ESR). Within the studies' chest CTs, the median number of involved lung lobes was 4 (range: 0-5) and the median number of involved lung segments was 9 (range 0-20). The left lower lobe and the right lower lobe were the most likely areas to be involved (89.0% and 83.9%), and 84.7% of the patients had inflammatory changes in both lungs. The main manifestations on chest CT were ground glass opacities (31.4%), ground glass opacities and consolidation (20.3%), ground glass opacities and reticular patterns (32.2%), mixed type (13.6%), and white lungs (1.7%); common accompanying signs included linear opacities (55.9%), air bronchograms (46.6%), thick small vessel shadows (36.4%), and pleural hypertrophy (13.6%). The chest CT at discharge showed complete absorption of lesions in 19 cases (16.1%), but not in the remaining 99 cases. Lesions remained in a median of 3 lung lobes (range: 0-5). Residual lesions remained in a median of 5 lung segments (range: 0-20). The residual lesions mainly presented as ground glass opacities (61.0%), and the main accompanying sign was linear opacities (59.3%). Based on chest CT, the median maximum PII of lungs was 30.0% (range: 0-97.5%), and the median PII after discharge in the patients excluding the two deaths was 12.5% (range: 0-53.0%). PII was significantly negatively correlated with the LYM count and significantly positively correlated with body temperature, LDH, CRP, and ESR. There was no significant correlation between the PII and the white blood cell count, but the grade of PII correlated well with the clinical classification. PII can be used to monitor the severity and the treatment outcome of COVID-19 pneumonia, provide help for clinical classification, assist in treatment plan adjustments and aid assessments for discharge.

An uncommon manifestation of COVID-19 pneumonia on CT scan with small cavities in the lungs: A case report.

RATIONALE: Chest computed tomography (CT) scans play a key role in diagnosing and managing of COVID-19 pneumonia. The typical manifestations of COVID-19 pneumonia on a chest CT scan are ground glass opacities, consolidation, nodules, and linear opacities. It can be accompanied by a "crazy-paving" pattern, air bronchograms, pleural hypertrophy, and pleural effusion. However, no literature has reported a case with cavities in the lungs. PATIENT CONCERNS: A 34-year-old male patient complained of fever, cough, fatigue, myalgia, diarrhea, headache, and dizziness for 2 weeks. This patient is living in Xiaogan, a city around Wuhan, and he had contact with a patient with COVID-19 pneumonia from Wuhan <14 days before he had fever. DIAGNOSIS: A nucleic acid test by rRT-PCR returned positive on a pharyngeal swab, confirming the diagnosis of COVID-19 pneumonia. INTERVENTIONS: Isolation antiviral treatment. OUTCOMES: After 19 days of isolation and antiviral treatment, his temperature returned to normal and the symptoms were relieved. The laboratory results also were returning to normal levels. The chest CT scan showed that the acute inflammation had subsided significantly. With 2 consecutive novel coronavirus nucleic acid tests had returned negative, the patient was discharged from the hospital and sent to a government designated hotel for quarantine observation. The unique chest CT manifestation in this case was the small cavities in both lungs during the absorption phase of this disease. These small cavities developed into consolidated nodules with clear edges and gradually shrank or disappeared. LESSONS: Although 2 consecutive nucleic acid tests returned negative in this patient, the small cavity changes in the lungs were observed, so the patient was quarantined for 14 days. However, follow-up CT after the first 14 days' quarantine showed new small cavity changes on the lungs, a further 14 days of quarantine was recommended. Therefore, in some COVID-19 cases, even if the nucleic acid tests turns negative, the disappearance of lung lesions may take a long time. The repeated chest CT scan plays an important role in the diagnosis and evaluation of the recovery of COVID-19.

MicroRNA-16 participates in the cell cycle alteration of HepG2 cells induced by MC-LR.

Microcystin-LR (MC-LR) is a cyclic hepatotoxin produced by cyanobacteria in freshwater, and chronic MC-LR exposure could induce human hepatitis if consumed in drinking water. In recent years, many studies have indicated that microRNAs participate in the hepatotoxicity of MC-LR. The purpose of this study was to investigate the potential function of miR-16 in the hepatocellular toxicity and cell cycle alteration induced by MC-LR in human hepatocellular carcinoma (HepG2) cells after treatment with 10 µM MC-LR. The result of flow cytometry detection showed that a low concentration of MC-LR (10 µM) failed to induce apoptosis but promoted cell cycle G1/S transition in HepG2 cells. In addition, the expression of apoptosis-related genes was suppressed after MC-LR exposure. These results confirm that MC-LR exposure at a low dose can promote the proliferation of HepG2 cells. Furthermore, we also found that microRNA-16 (miR-16) expression was suppressed in HepG2 cells following MC-LR exposure. Hence, we overexpressed miR-16 in HepG2 cells and treated them with MC-LR, and the results showed that miR-16 overexpression induced an increase in the G0/G1 phase and a decrease in the S phase cell cycle populations in HepG2 cells, suggesting that miR-16 can inhibit the cell proliferation of HepG2 cells. In conclusion, our results suggest that miR-16 may play a vital role in the cell cycle alteration of HepG2 cells after MC-LR exposure.

Aberrant Expressional Profiling of Known MicroRNAs in the Liver of Silver Carp (Hypophthalmichthys molitrix) Following Microcystin-LR Exposure Based on samllRNA Sequencing.

Microcystin-LR (MC-LR) poses a serious threat to human health due to its hepatotoxicity. However, the specific molecular mechanism of miRNAs in MC-LR-induced liver injury has not been determined. The aim of the present study was to determine whether miRNAs are regulated in MC-LR-induced liver toxicity by using high-throughput sequencing. Our research demonstrated that 53 miRNAs and 319 miRNAs were significantly changed after 24 h of treatment with MC-LR (50 and 200 µg/kg, respectively) compared with the control group. GO enrichment analysis revealed that these target genes were related to cellular, metabolic, and single-organism processes. Furthermore, KEGG pathway analysis demonstrated that the target genes of differentially expressed miRNAs in fish liver were primarily involved in the insulin signaling pathway, PPAR signaling pathway, Wnt signaling pathway, and transcriptional misregulation in cancer. Moreover, we hypothesized that 4 miRNAs (miR-16, miR-181a-3p, miR-451, and miR-223) might also participate in MC-LR-induced toxicity in multiple organs of the fish and play regulatory roles according to the qPCR analysis results. Taken together, our results may help to elucidate the biological function of miRNAs in MC-LR-induced toxicity.

Alteration in the expression of cytochrome P450s (CYP1A1, CYP2E1, and CYP3A11) in the liver of mouse induced by microcystin-LR.

Microcystins (MCs) are cyclic heptapeptide toxins and can accumulate in the liver. Cytochrome P450s (CYPs) play an important role in the biotransformation of endogenous substances and xenobiotics in animals. It is unclear if the CYPs are affected by MCs exposure. The objective of this study was to evaluate the effects of microcystin-LR (MCLR) on cytochrome P450 isozymes (CYP1A1, CYP2E1, and CYP3A11) at mRNA level, protein content, and enzyme activity in the liver of mice the received daily, intraperitoneally, 2, 4, and 8 µg/kg body weight of MCLR for seven days. The result showed that MCLR significantly decreased ethoxyresorufin-O-deethylase (EROD) (CYP1A1) and erythromycin N-demthylase (ERND) (CYP3A11) activities and increased aniline hydroxylase (ANH) activity (CYP2E1) in the liver of mice during the period of exposure. Our findings suggest that MCLR exposure may disrupt the function of CYPs in liver, which may be partly attributed to the toxicity of MCLR in mice.

Effects of 1-octyl-3-methylimidazolium bromide on the antioxidant system of Lemna minor.

Ionic liquids have gained more attention due to their excellent properties in many different scientific fields. However, previous researches indicated that ionic liquids have adverse effects on organisms. The objective of this study was to evaluate the effects of 1-octyl-3-methylimidazolium bromide ([C(8)mim]Br) on the aquatic plant duckweed (Lemna minor) by exposure of the plant to 0.25 to 2 mg L(-1) of [C(8)mim]Br for 28 days. Exposure to [C(8)mim]Br significantly decreased the photosynthetic pigment contents at 21 and 28 days. The activities of superoxide dismutase and catalase and the total antioxidant capacity level increased at 7 days of exposure and decreased at the termination of exposure. In contrast, the H(2)O(2) content and peroxidase activity in all treatments increased during the period of exposure. Furthermore, marked increase of malondialdehyde content occurred in duckweed after 21 to 28 days of exposure. In addition, reactive oxygen species (ROS) scavenger dimethyl thiourea prevents duckweed from oxidative damage caused by [C(8)mim]Br. These results suggest that ROS might be involved in the mechanism of ionic liquid-induced toxicity in L. minor.

Acute toxicity and effects of 1-alkyl-3-methylimidazolium bromide ionic liquids on green algae.

In the present study, the acute toxicity of 1-Alkyl-3-methylimidazolium bromide ([Cnmim]Br) on the green algal Scenedesmus obliquus and Chlorella ellipsoidea was determined. The length of alkyl side chain of these imidazolium ionic liquids were C4, C6, C8, C10 and C12. The primary production of S. obliquus was also assessed after they were exposed to 0.01, 0.05, 0.10, 0.50 and 1.00 mg/L of [C10mim]Br for 96 h. The results showed that the acute toxicity of these ionic liquids was positively correlated with the alkyl chain length. Meanwhile, the concentration of the ionic liquid strongly influenced the primary production of algae. These results indicate that [Cnmim]Br with longer alkyl length have toxic effects on the green algae, and the risk to aquatic ecosystems by ionic liquid's leaking into the water body must be evaluated in the future.

Effects of the 1-alkyl-3-methylimidazolium bromide ionic liquids on the antioxidant defense system of Daphnia magna.

This study examined the antioxidant responses of Daphnia magna following exposure to different concentrations of the ionic liquid (IL) 1-octyl-3-methylimidazolium bromide and the 50% LC(50) concentrations of methylimidazolium bromide ILs with different alkyl-chain lengths. Activities of antioxidant defense enzymes (superoxide dismutase, catalase, glutathione peroxidase, and glutathione S-transferase) and levels of the antioxidant glutathione and the lipid peroxidation by-product malondialdehyde were measured using traditional methods or commercial kits. The concentration and the alkyl-chain length of ILs were found to strongly influence the antioxidant system of D. magna following IL exposure, and exposure to higher IL concentrations and to ILs with longer alkyl chains generally increased the enzyme activities and biomarker levels examined. Therefore, the present study suggests that oxidative stress is involved in the mechanism of IL-induced toxicity in D. magna.

[Optimally control urban railway noise by sound propagation path].

In order to control railway noise pollution in urban areas, the residential district located near the Zhegan railway in Hangzhou urban was taken for example, and some controlling measures were proposed based on the investigation in railway noise impact as well as the planning of the district, the environmental scene and the project devises. The measures included setting man-made soil slopes, noise barriers and virescence. Combining some of them could be a typical noise reduction scheme. The professional software Cadna/A was used to predict the noise reduction results of every scheme. Results show that the maximal difference of noise reduction is 19.4 dB and the noise reduction effect of the second scheme is best. However, if only railway noise influence is considered, the first scheme is best. The research results can provide reference for residential districts planning and noise control near the railway in urban areas.

[Impact of low-frequencies noise on the ability of thinking and judgment].

Three typical low frequency noise samples which were collected from some associated facilities in urban residential areas and white noise which was produced by acoustic apparatus were selected to compare the competence of brainwork index (AYP) and error rate in noisy environment with those in quiet environment, using dosage exercise method. The result indicates that AYP is lower in noisy environment and the error rate is higher than that in quiet environment, and there are significant differences between them. The changes of most testees in groups that use three different low frequency noise samples respectively are more obvious than the group that uses white noise, and the AYP difference attains significant level. It indicates that low frequency components are the main frequency elements to affect the ability of thinking and judgment. By paired samples t-test and frequency spectrums analysis, the results show that the impact degree of air condition outdoor unit noise is highest, and noise samples which have a peak frequency between 50-300 Hz have a more negative impact on the ability of thinking and judgment than other environmental noise.

The developmental toxicity of 1-methyl-3-octylimidazolium bromide on Daphnia magna.

The developmental toxicity of 1-methyl-3-octylimidazolium bromide ([C(8)mim]Br) on Daphnia magna was investigated. The 24 and 48 h LC(50) values for [C(8)mim]Br in D. magna were 1.99 and 0.95 mg/L, respectively. A series of multigenerational toxicity tests were then used to explore [C(8)mim]Br effects in D. magna. [C(8)mim]Br significantly inhibited the body lengths of the F0 and F1 1st generations. After 21 days of exposure, [C(8)mim]Br lowered the reproductive ability of the F0 and F1 1st generations. In F1 3rd generation, 21 days of [C(8)mim]Br exposure prolonged the time to bear the first egg and the time to the first brood compared with the control, but the number of first-brood offspring and the number of broods produced by these animals were reduced. After the recovery period all the reproductive parameters returned to normal in F1 1st generation except for the number of broods. The dead neonates increased with prolonged exposure and increasing concentrations, and the dead neonates of the F1 3rd generation went far beyond that of the F1 1st and F0 generations. The intrinsic rate of natural increase (r) values of the three D. magna generations significantly decreased after exposure to higher concentrations of [C(8)mim]Br compared with control groups. Collectively, these results suggest that [C(8)mim]Br exerts a toxic effect on the development of D. magna. This study also highlights the importance of systematically evaluating the potential effects of aquatic ecosystems of ionic liquids that may be released into bodies of water.

Acute effects of 1-octyl-3-methylimidazolium bromide ionic liquid on the antioxidant enzyme system of mouse liver.

The effects of acute exposure of intraperitoneal injection of aqueous 1-octyl-3-methylimidazolium bromide on the antioxidant enzymes and lipid peroxidation of the treated mouse liver were investigated in the present paper. Thirty mice were treated with 17.9 (0.5 median lethal dose, LD(50)) and 35.7 mg/kg (1 LD(50)) of the ionic liquid or saline solution by intraperitoneal injection for 10h. Significant increase in hepatosomatic index and decrease in liver protein content were found in 1 LD(50) group. No statistically significant change was observed in the activity of superoxide dismutase in both treated groups compared to the control group. In the case of catalase activity, the decrease was recorded only at dose of 1 LD(50). As for the activity of glutathione peroxidase, increase in 0.5 LD(50) group while significant decrease at dose of 1 LD(50) was noted. There was an increase in the activity of glutathione-S-transferase in these two treated groups in comparison to the control. However, no effect on the level of lipid peroxidation was found in the treated groups. These results showed that the acute exposure of aqueous ionic liquid could cause damage to mouse, leading to antioxidant responses in livers of the treated mice.