Ecotoxicology最新文献

{"title":"Correction to: Simulated herbicide drift alters native plant flowering phenology.","authors":"David Olszyk, Thomas Pfleeger, Tamotsu Shiroyama, Matthew Blakeley-Smith, E Henry Lee, M S Nash, Milton Plocher","doi":"10.1007/s10646-024-02828-x","DOIUrl":"10.1007/s10646-024-02828-x","url":null,"abstract":"","PeriodicalId":11497,"journal":{"name":"Ecotoxicology","volume":" ","pages":"167"},"PeriodicalIF":2.4,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142616663","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"In vitro and in vivo effects of commercial and environmental microplastics on Unio delicatus.","authors":"Pınar Arslan Yüce, Aysel Çağlan Günal, Belda Erkmen, Begüm Yurdakok-Dikmen, Ali Serhan Çağan, Tamer Çırak, Gökben Başaran Kankılıç, Melike Seyfe, Ayhan Filazi, Ülkü Nihan Tavşanoğlu","doi":"10.1007/s10646-024-02807-2","DOIUrl":"10.1007/s10646-024-02807-2","url":null,"abstract":"<p><p>Microplastics (MPs) are ubiquitous pollutants in freshwater environments. In this study, freshwater mussels, Unio delicatus, were exposed to both environmental MPs (e-MP) and commercial MPs (c-MP) that include green fluorescent MP (gf-MP), polyethylene (c-PE) and polystyrene (c-PS) at environmental concentrations (5 mg/L and 50 mg/L) over duration of 7 and 30 days. According to in vivo experiment results, both e-MPs and c-MPs induced significant changes in the total hemocyte counts of mussels (p < 0.05). Exposure to high concentrations of e-MPs and c-MPs for 7 days led to decreased cellular glutathione levels in the mussels, while exposure to low concentrations of e-MPs and c-PS for 7 days resulted in increased advanced oxidation protein products (AOPP). Mussels exposed to high concentrations of e-MPs for 30 days exhibited decreases in both glutathione levels and AOPP values. Although no damage was observed in tissues other than gills and digestive gland, histopathological alterations were observed in these tissues following exposure to 50 mg/L c-MPs. Additionally, MPs were observed in the intestine tissues. In vitro experiments using the MTT assay showed no significant difference in cell viability between the MP-exposed group and the control group at tested concentrations, with no observed dose-response relationship (p > 0.05). Nevertheless, certain cells exhibited signs of cell death, such as disrupted cellular structures, condensed nuclei, and loss of cellular integrity. These observations were consistent with mechanical compression, indicating that physical contact with MPs may result in cell damage or death. These findings demonstrate that environmentally relevant concentrations of MPs have toxic effects on freshwater mussels and multiple parameters provide valuable insight for the evaluation of health risks of organisms.</p>","PeriodicalId":11497,"journal":{"name":"Ecotoxicology","volume":" ","pages":"22-37"},"PeriodicalIF":2.4,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142460661","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Evaluation of the lethal and sublethal effects of fenpyroximate on Scolothrips longicornis, a non-target predator of spider mites.","authors":"Hajar Pakyari, Rostislav Zemek","doi":"10.1007/s10646-024-02818-z","DOIUrl":"10.1007/s10646-024-02818-z","url":null,"abstract":"<p><p>Understanding the lethal and sublethal impacts of pesticides on biocontrol agents is crucial for the successful implementation of integrated pest management (IPM) programs. This study investigated the sublethal effects of fenpyroximate, a broad-spectrum acaricide/insecticide, on the fitness of Scolothrips longicornis Priesner (Thysanoptera: Thripidae), a key predator of the two-spotted spider mite, in controlled laboratory environments. Adult predators were exposed to pesticide residues on leaf discs to estimate parameters of concentration-mortality response models for females and males and calculate median lethal concentration (LC₅₀) as well as sublethal concentrations (LC₁₀, LC₂₀ and LC₃₀) used in subsequent bioassays. The estimated LC₅₀ values for female and male predators were 18.32 and 15.49 µg a.i./mL, respectively. Results of sublethal concentrations experiments did not reveal any significant impact on the development of each stage or the survival rate of S. longicornis juveniles compared to those in the control group. However, the longevity of adult males and females was significantly lower at all sublethal concentrations than in the control. Moreover, the fecundity decreased significantly at all sublethal concentration treatments. With one exception (LC₁₀), both the adult preoviposition period and total preoviposition period increased with increasing sublethal concentrations compared to those of the control. The shortest oviposition period (9.30 days) was observed at the LC₃₀. For the life table parameters of S. longicornis females treated with sublethal concentrations, a significant decrease was found in the intrinsic rate of increase, net reproductive rate and finite rate of increase, whereas the mean generation time in the LC₁₀ treatment was lower than that in the other treatments. This underscores the imperative need to consider sublethal concentration effects of fenpyroximate in the strategic design and implementation of IPM systems.</p>","PeriodicalId":11497,"journal":{"name":"Ecotoxicology","volume":" ","pages":"11-21"},"PeriodicalIF":2.4,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142603850","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Shoal size as a key variable in fish behavioral ecotoxicology: an example using sertraline.","authors":"Asma Al Shuraiqi, Michael J Barry","doi":"10.1007/s10646-024-02826-z","DOIUrl":"10.1007/s10646-024-02826-z","url":null,"abstract":"<p><p>A significant limitation of behavioral ecotoxicology is the challenge of obtaining reproducible results due to a wide range of testing conditions. In particular, shoal size affects almost all aspects of fish behavior, but is rarely considered as a factor in ecotoxicological studies. In the present study, we compared the swimming and antipredator responses of different sized shoals of Arabian killifish (Aphaniops stoliczkanus) after exposure to environmentally realistic concentrations of the antidepressant medication sertraline. Groups of fish (1, 3 or 5 individuals) were exposed to either 5 or 50 ng/L sertraline. After 37 days, swimming behavior and responses to a predator alarm were measured. We found that the effects of group size were much stronger than the effects of sertraline on swimming. Group size was also the major factor influencing responses to the predator alarm, with single fish showing the strongest responses. Sertraline directly affected acceleration, turning speed and average distance to the arena wall. For all three parameters, there were significant interactions with shoal size, demonstrating that responses differed depending on the size of the group. We also found that effects of sertraline could still be observed 14 days after cessation of exposure. The study highlights the importance of considering social context and specifically shoal size when designing behavioral studies on chemicals. Failure to consider this may result in over- or under-estimation of risks.</p>","PeriodicalId":11497,"journal":{"name":"Ecotoxicology","volume":" ","pages":"156-166"},"PeriodicalIF":2.4,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142568135","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Distinctive toxic repercussions of polystyrene nano plastic towards aquatic non target species Nitrobacter vulgaris, Scenedesmus sp and Daphnia magna.","authors":"Sowmya Sri Nagaraja, Yerimma Gouda, Diana Miguez, Yuvashree Muralidaran, Luiz Fernando Romanholo Ferreira, Juliana Heloisa Pinê Américo-Pinheiro, Sikandar I Mulla, Prabhakar Mishra","doi":"10.1007/s10646-024-02810-7","DOIUrl":"10.1007/s10646-024-02810-7","url":null,"abstract":"<p><p>The widespread application of plastics and its eventual degradation to micro-sized or nano-sized plastics has led to several environmental concerns. Moreover, nanoplastics can easily cascade through the food chain accumulating in the aquatic organisms. Thus, our study focussed on investigating the hazardous impact of nano-sized plastics on aquatic species including Nitrobacter vulgaris, Scenedesmus sp, and Daphnia magna. Various concentrations of polystyrene nanoplastics ranging from 0.01 mg/L to 100 mg/L were tested against Nitrobacter vulgaris, Scenedesmus sp, and Daphnia magna. The minimum inhibitory concentration of polystyrene nanoplastics in Nitrobacter vulgaris was found to be 25 mg/L, and in Daphnia magna, the median lethal concentration 50 was observed to be 64.02 mg/L. Exposure of Scenedesmus sp with increasing nanoplastic concentrations showed a significant decrease in total protein (p < 0.001), and chlorophyll content (p < 0.01), whereas the lipid peroxidation increased (p < 0.001) significantly. Similarly, Nitrobacter vulgaris and Daphnia magna showed a significant decrease in catalase activity (p < 0.001) and an increase in lipid peroxidation levels (p < 0.01). Concomitant with lipid peroxidation results, decreased superoxide dismutase levels (p < 0.01) and protein concentrations (p < 0.01) were observed in Daphnia magna. Besides, the increasing concentration of polystyrene nanoplastics displayed an elevated mortality rate in Scenedesmus sp (p < 0.001) and Nitrobacter vulgaris (p < 0.01). Further, scanning electron microscopy analysis substantiated the morphological alterations in Nitrobacter vulgaris and Scenedesmus sp on exposure to polystyrene nanoplastics.</p>","PeriodicalId":11497,"journal":{"name":"Ecotoxicology","volume":" ","pages":"61-75"},"PeriodicalIF":2.4,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142388925","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Gut microbiome as biomarker for triclosan toxicity in Labeo rohita: bioconcentration, immunotoxicity and metagenomic profiling.","authors":"Angom Baleshwor Singh, Tapas Paul, S P Shukla, Saurav Kumar, Sanath Kumar, Ganesh Kumar, Kundan Kumar","doi":"10.1007/s10646-024-02817-0","DOIUrl":"10.1007/s10646-024-02817-0","url":null,"abstract":"<p><p>Triclosan (TCS) is a lipophilic, broad spectrum antimicrobial agent commonly used in personal care products with a projected continuous escalation in aquatic environments in the post COVID 19 era. There is rich documentation in the literature on the alteration of physiological responses in fish due to TCS exposure; however, studies on gut associated bacteria of fish are still scarce. This is the first attempt to determine changes in bacterial community structure due to exposure of TCS on Labeo rohita, a commercially essential freshwater species, using 16S V3-V4 region ribosomal RNA (rRNA) next-generation sequencing (NGS). Chronic exposure of TCS at environmentally realistic concentrations viz. 1/5th (T₁: 0.129 mg/L) and 1/10th (T₂: 0.065 mg/L) of LC₅₀ for 28 days resulted in the dose dependent bioconcentration of TCS in the fish gut. Prolonged exposure to TCS leads to disruption of gut bacteria evidenced by down regulation of the host immune system. Additionally, high-throughput sequencing analysis showed alternation in the abundance and diversity of microbial communities in the gut, signifying Proteobacteria and Verrucomicrobia as dominant phyla. Significant changes were also observed in the relative abundance of Chloroflexi and Gammatimonadetes phyla in TCS exposed groups. The study revealed that gut microbiome can be used as a biomarker in assessing the degree of TCS toxicity in commercially important fish species.</p>","PeriodicalId":11497,"journal":{"name":"Ecotoxicology","volume":" ","pages":"102-111"},"PeriodicalIF":2.4,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142460660","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Evaluating the influence of sulphur dioxide and nitrogen dioxide in ambient air on biochemical factors contributing to plant tolerance.","authors":"Navneet Kour, Prasenjit Adak","doi":"10.1007/s10646-024-02820-5","DOIUrl":"10.1007/s10646-024-02820-5","url":null,"abstract":"<p><p>Air pollutants, specifically, Sulphur Dioxide (SO₂) and Nitrogen Dioxide (NO₂) cause numerous biochemical changes in plants; by studying the biochemical parameters, plant resistance against these pollutants can be evaluated. The effect of air pollutants on biochemical parameters such as ascorbic acid (AA), total chlorophyll (TC), pH and the relative water content (RWC) of leaves has been investigated in the present study. The objective of the present study was to observe the relationship between biochemical parameters of plants and ambient air pollutants (SO₂ and NO₂). The morphological and biochemical changes of the sampled leaves of different plants were studied. Simultaneously, ambient air quality data was collected from the central pollution control board (CPCB) online portal. Among the sampled plants, Ficus religiosa and Morus alba plant species can be recommended as tolerant for the sampling sites: Jalandhar, Amritsar, and Ludhiana. Ficus benghalensis and Ficus religiosa can be recommended as tolerant for Chandigarh sector 25 and 53 respectively. As a result, it has been observed that SO₂ has a negative effect on the relative water content and ascorbic acid content of most plant species, while NO₂ can have ambiguous effect on plants (toxic and beneficial), and no strong association has been found with biochemical parameters. The current study provides pollutant-specific information and insights into the variations caused by air pollutants. The present study will contribute in suggesting the tolerant plant species that could provide new approaches for developing urban landscapes.</p>","PeriodicalId":11497,"journal":{"name":"Ecotoxicology","volume":" ","pages":"127-142"},"PeriodicalIF":2.4,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142675455","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Investigating the toxicity of polylactic acid microplastics on the health and physiology of freshwater fish, Cirrhinus mrigala.","authors":"Eram Rashid, Syed Makhdoom Hussain, Shafaqat Ali, Pallab K Sarker, Mohammad Abul Farah","doi":"10.1007/s10646-024-02813-4","DOIUrl":"10.1007/s10646-024-02813-4","url":null,"abstract":"<p><p>The widespread presence of microplastics (MPs) in aquatic ecosystems has raised growing concerns among ecotoxicologists regarding their potential toxicity. This study explored the impacts of polylactic acid (PLA) MPs on the physiology and health of freshwater fish, Cirrhinus mrigala, by dietary exposure for 90 days. The experiment consisted of six groups: five treatment groups (0.5%, 1%, 1.5%, 2%, and 2.5% PLA-MP) and a control group (0% PLA-MP). Each group was comprised of fifteen fish, and the experiment was replicated three times. The exposure severity of PLA-MPs varied from low to high, with treatment levels ranging from 0.5% to 2.5% PLA-MPs, relative to the control group. This exposure significantly affected their growth performance. Additionally, the apparent digestibility of the SFM-based diet decreased with increasing PLA-MPs concentration. Exposure to PLA-MPs induced considerable changes in body composition, characterized by increased moisture and crude fat content and decreased ash content and crude protein. The blood profile, including MCHC, RBCs, Hb, PLT and PCV exhibited significant declines in the high treatment group (2.5% PLA-MPs), while MCH, WBCs and MCV showed notable increases. Furthermore, histopathological examination of the intestine revealed an increase in abnormalities in the intestine at 2.5% PLA-MPs level. The high treatment group (2.5% PLA-MPs) showed the lowest mineral content in the fish muscles. In summary, dietary exposure to PLA-MPs led to alterations in overall body performance across the treatment groups, ranging from low to high severity levels.</p>","PeriodicalId":11497,"journal":{"name":"Ecotoxicology","volume":" ","pages":"1210-1221"},"PeriodicalIF":2.4,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142361328","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Toxicodynamics of cadmium in the green mussel Perna viridis (Linnaeus, 1758) using bioenergetic and physiological biomarkers.","authors":"Kariyil Veettil Neethu, Neethu Xavier, Punnakkal Hari Praved, Naduvath Deepak Sankar, Punnathi Anilkumar Athira, Sivasankaran Bijoy Nandan, Kandussery Joseph Joseph, Shambanagouda Rudragouda Marigoudar, Krishna Venkatarama Sharma","doi":"10.1007/s10646-024-02814-3","DOIUrl":"10.1007/s10646-024-02814-3","url":null,"abstract":"<p><p>This study evaluated the toxicity of cadmium (Cd) on the green mussel Perna viridis, aiming to identify toxicological endpoints and investigate its responses across physiological, bioenergetic, and biochemical parameters. The 96-hour LC₅₀ value for Cd in P. viridis was 3.03 ± 0.12 mg L^-1, with a 95% confidence interval of 2.35-3.91 mg L^-1. Chronic toxicity tests revealed a No Observable Effect Concentration (NOEC), Lowest Observable Effect Concentration (LOEC), and chronic toxicity values of 0.20, 0.37, and 0.29 mg L^-1, respectively. Cadmium accumulation in treated mussels increased 46- to 215-fold compared to the control group. Superoxide dismutase, catalase, glutathione S-transferase, and glutathione peroxidase levels in exposed mussels exhibited a significant increase compared to the control group. The redox index ratio, acetylcholinesterase activity, and lysosomal membrane stability decreased with increasing exposure concentrations. Levels of reduced and oxidized glutathione, glutathione reductase, lipid peroxidation, and metallothionein-like proteins increased in exposed mussels. Clearance rate, respiration rate, and excretion rate decreased in a dose-dependent manner. Protein, carbohydrate, and lipid levels decreased with increasing exposure concentration (p < 0.001). Mitochondrial electron transport system activity increased, while cellular energy allocation (p < 0.001) and scope for growth decreased in a dose-dependent manner (p < 0.01). The significant increase in antioxidants suggests heightened oxidative stress in mussels under Cd exposure. The physiological activities of the mussels were severely affected, ultimately leading to a reduced scope for growth. The toxicological data generated in this study contribute to the development of seawater quality criteria for the metal Cd.</p>","PeriodicalId":11497,"journal":{"name":"Ecotoxicology","volume":" ","pages":"1222-1241"},"PeriodicalIF":2.4,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142388928","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effects of aerial liming on soil chemical and biological properties in metal contaminated and inaccessible lands in Ontario (Canada).","authors":"Katheryn Klajman, Peter Beckett, Graeme Spiers, Kabwe Nkongolo","doi":"10.1007/s10646-024-02804-5","DOIUrl":"10.1007/s10646-024-02804-5","url":null,"abstract":"<p><p>The manual addition of lime to soil, in addition to tree planting and fertilization have been the dominant strategy described in restoration protocols for ecosystems damaged by acid rain and metal contamination. Investigations on aerial-limed soils in inaccessible lands are limited. The objective of this study was to assess the effects of aerial liming on soil pH, organic matter, microbial biomass, and enzymatic activities, and aboveground plant population quality in metal-contaminated lands in northern Ontario, Canada. Soil samples were collected from three sites around the City of Greater Sudbury with each pair being composed of a reclaimed (areal-limed) site and an adjacent undisturbed (unlimed) area. Soil physico-chemistry, microbial biomass (assessed by Phospholipid fatty acid analysis) and enzymatic activities were analyzed. Soil pH was higher in limed sites compared to unlimed at recently restored sites (Baby Lake and Wahnapitae) but not at the oldest reclaimed site (HWY 80 N). Organic matter was higher in limed areas compared to the unlimed reference site only at most recently reclaimed site at Baby Lake. Aboveground plant population health was visibly improved in limed sites compared to unlimed areas. Metal concentrations of iron (Fe) and arsenic (As), total microbial biomasses, gram-negative bacterial, fungal, and eukaryotic biomasses were all significantly increased in the limed soils compared to the unlimed samples. The same trend was observed for the activities of three of the enzymes tested, β-N-acetylglucosaminidase (BG), aryl sulfatase (AS), and glycine aminopeptidase (GAP). Interestingly, strong positive correlations between the levels of soil organic matter, microbial biomasses, and NAGase and ALP activities were observed. Although expensive, aerial liming is effective in restoring inaccessible sites impacted by smelting operations where other methods cannot easily be used.</p>","PeriodicalId":11497,"journal":{"name":"Ecotoxicology","volume":" ","pages":"1145-1160"},"PeriodicalIF":2.4,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142379224","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}