82 research outputs found
Different dynamic accumulation and toxicity of ZnO nanoparticles and ionic Zn in the soil sentinel organism Enchytraeus crypticus
There is still no consensus over the specific effects of metal-based nanoparticles when compared with the conventional metal salts. Here, the accumulation and toxicity of ZnO-NPs and ZnCl2 in Enchytraeus crypticus over time (1–14 d) were investigated using a sand-solution exposure medium and applying a toxicokinetics and toxicodynamics approach. For both Zn forms, body Zn concentration in the organisms was dependent on both the exposure concentration and exposure time, with equilibrium being reached after 7–14 days of exposure. Generally, the uptake and elimination rate constants (Ku and Ke1) were smaller for ZnO-NPs (5.74–12.6 mg kg−1d−1 and 0.17–0.39 d−1) than for ZnCl2 (8.32–40.1 mg kg−1d−1 and 0.31–2.05 d−1), suggesting that ionic Zn was more accessible for E. crypticus than nanoparticulate Zn. Based on external exposure concentrations, LC50s for ZnO-NPs and ZnCl2 decreased with time from 123 to 67 Zn mg L−1 and from 86 to 62 Zn mg L−1, reaching an almost similar ultimate value within 14 d. LC50s based on body Zn concentrations were almost constant over time (except for 1 d) for both ZnO-NPs and ZnCl2, with overall LC50body of Zn being 1720 and 1306 mg kg−1 dry body weight, respectively. Body Zn concentration, which considers all available pathways, was a good predictor of dynamic toxicity of ZnCl2, but not for ZnO-NPs. This may be attributed to the specific internal distribution and detoxification mechanisms of ZnO-NPs. The particles from ZnO-NPs dominated the accumulation (>75%) and toxicity (∼100%). Our results suggest that dynamic aspects should be taken into account when assessing and comparing NPs and metals uptake and consequent patterns of toxicity
Model-based rationalization of mixture toxicity and accumulation in Triticum aestivum upon concurrent exposure to yttrium, lanthanum, and cerium
Rare earth elements (REEs) often co-exist in the environment, but predicting their ‘cocktail effects’ is still challenging, especially for high-order mixtures with more than two components. Here, we systematically investigated the toxicity and accumulation of yttrium, lanthanum, and cerium mixtures in Triticum aestivum following a standardized bioassay. Toxic effects of mixtures were predicted using the reference model of Concentration Addition (CA), Ternary model, and Ternary-Plus model. Interactions between the REEs in binary and ternary mixtures were determined based on external and internal concentrations, and their magnitude estimated from the parameters deviated from CA. Strong antagonistic interactions were found in the ternary mixtures even though there were no significant interactions in the binary mixtures. Predictive ability increased when using the CA model, Ternary model, and Ternary-Plus model, with R2 = 0.78, 0.80, and 0.87 based on external exposure concentrations, and R2 = 0.72, 0.73, and 0.79, respectively based on internal concentrations. The bioavailability-based model WHAM-FTOX explained more than 88 % and 85 % of the toxicity of binary and ternary REE treatments, respectively. Our result showed that the Ternary-Plus model and WHAM-FTOX model are promising tools to account for the interaction of REEs in mixtures and could be used for their risk assessment
Transformation behaviors and environmental risk assessment of heavy metals during resource recovery from Sedum plumbizincicola via hydrothermal liquefaction
Environmentally sound disposal of hyperaccumulator harvests is of critical importance to industrialization of phytoremediation. Herein, transformation behaviors and environmental risk of heavy metals were comprehensively examined during subcritical hydrothermal liquefaction of Sedum plumbizincicola. It is concluded that low temperature liquefaction favored resource recovery of heavy oil and hydrochars in terms of higher energy density, improved carbon sequestration and less energy consumption. Heavy metals were mainly distributed into hydrochars and water soluble phase with less than 10% in heavy oil. All metal elements except As could be accumulated in hydrochars by extending reaction time, whereas more than 96% of As was redistributed into water soluble phase. Prolonged liquefaction time facilitated immobilization of Cd, Cr and As in hydrochars, but fast liquefaction favored Pb stabilization. Liquefaction significantly reduced environmental risk level of Cd, Zn and As, but may mobilize Pb and Mn, especially for Mn to very high risk level at 240 ºC. High temperature with long reaction time tended to inhibit leaching rate of Mn, whereas low liquefaction temperature with short reaction time prevented the leaching of Zn and As from hydrochars. Overall, these findings are essential for downstream upgrading of heavy oil and metals recovery from hydrochars.acceptedVersionPeer reviewe
Using the concept of preperitoneal membrane anatomy in total extraperitoneal prosthesis: a preliminary report
PurposeTotal extraperitoneal prosthesis (TEP) is one of the most commonly used laparoscopic inguinal hernia repair procedures. This work aims to report the application of membrane anatomy to TEP and its value in intraoperative space expansion.MethodsThe clinical data of 105 patients, from January 2018 to May 2020, with inguinal hernia who were treated with TEP (58 patients in the General Department of the Second Hospital of Sanming City, Fujian Province, and 47 patients in the General Department of the Zhongshan Hospital Affiliated to Xiamen University) were retrospectively analyzed.ResultsAll surgeries were successfully completed under the guidance of the concept of preperitoneal membrane anatomy. The operation time was 27.5 ± 9.0 min, blood loss was 5.2 ± 0.8 ml, and the peritoneum was damaged in six cases. The postoperative hospital stay was 1.5 ± 0.6 days, and five cases of postoperative seroma occurred, all self-absorbed. During the follow-up period of 7–59 months, there was no case of chronic pain and recurrence.ConclusionThe membrane anatomy at the correct level is the premise of a bloodless operation to expand the space while protecting adjacent tissues and organs to avoid complications
Incidence and influencing factors of fertility concerns in breast cancer in young women: a systematic review and meta-analysis
ObjectiveThis systematic review and meta-analysis aimed to evaluate the prevalence and influencing factors of fertility concerns in breast cancer in young women.MethodsA literature search on PubMed, Embase, Web of Science, and Cochrane Library databases was conducted up to February 2023 and was analyzed (Revman 5.4 software) in this study. The papers were chosen based on inclusion standards, and two researchers independently extracted the data. The included studies’ quality was evaluated using criteria set out by the Agency for Healthcare Research and Quality. To identify significant variations among the risk factors, odds ratios (ORs) and the corresponding 95% confidence intervals (CIs) were utilized.ResultsA total of 7 studies that included 1579 breast cancer in young women were enrolled in the study. The results showed that for breast cancer in young women, the incidence of fertility concerns 53%(95%CI [0.45,0.58]). The results showed that education (2.65, 95% CI 1.65–5.63), full-time work (0.12, 95% CI 1.03–1.93), fertility intentions (7.84, 95% CI 1.50–37.4), depression level (1.25, 95% CI 1.03–1.5), and endocrine therapy (1.32, 95% CI 1.08–1.62) were risk factors for fertility concerns in young women with BC. Having a partner (0.41, 95% CI 0.33–0.5), ≥1 child (0.3, 95% CI 0.22–0.4) were identified as protective factors against fertility concerns in young women with BC.ConclusionsThe incidence of fertility concerns in breast cancer in young women is at a moderately high level. We should pay more attention to the risk factors of fertility concerns to help breast cancer in young women cope with their fertility concerns and promote their psychological well-being
Characterization of the Sesbania rostrata Phytochelatin Synthase Gene: Alternative Splicing and Function of Four Isoforms
Phytochelatins (PCs) play an important role in detoxification of heavy metals in plants. PCs are synthesized from glutathione by phytochelatin synthase (PCS), a dipeptidyltransferase. Sesbania rostrata is a tropical legume plant that can tolerate high concentrations of Cd and Zn. In this study, the S. rostrata PCS gene (SrPCS) and cDNAs were isolated and characterized. Southern blot and sequence analysis revealed that a single copy of the SrPCS gene occurs in the S. rostrata genome, and produces four different SrPCS mRNAs and proteins, SrPCS1–SrPCS4, by alternative splicing of the SrPCS pre-mRNA. The SrPCS1 and SrPCS3 proteins conferred Cd tolerance when expressed in yeast cells, whereas the SrPCS2 and SrPCS4 proteins, which lack the catalytic triad and the N-terminal domains, did not. These results suggested that SrPCS1 and SrPCS3 have potential applications in genetic engineering of plants for enhancing heavy metal tolerance and phytoremediation of contaminated soils
Application and mathematical modeling of anaerobic moving bed biofilm reactor in treating milk permeate wastewaters
Le réacteur anaérobie à biofilm sur lit mobile (anaérobie moving bed biofilm reactor, AMBBR) est une application prolongée de réacteur traditionnel à lit mobile aérobie. Cependant, aucune application d'AMBBR n'a été reportée pour traiter les effluents de laiterie. Les principales conclusions sont :1) Il a été montré que pour les faibles charges organiques, la qualité d'effluent a été principalement attribuée aux concentrations en boue libres et que c'est aux charges élevées que I' AMBBR prends tou te son importance. 2) L' AMBBR permet de traiter les eaux usées des laiteries chargées en perméat. Les résultats ont indiqué que I'AMBBR a mieux fonctionné en mésophilie qu'en psychrophilie. Il a montré des performances comprarables à d'autres technologies de digesteur. Des analyses des cinétiques ont permis d'évaluer les performances de l'AMBBR. Le coefficient de rendement de méthane, le coefficient de maintenance (entretient) des cellules et le taux d'utilisation maximum du substrat ont été déterminés pour I'AMBBR. 3) Un modèle mathématique d'AMBBR a été développé la première fois et valide.. Ce modèle pourrait aussi être utilisé pour la conduite de I' AMBBR.Anaerobic moving bed biofilm reactor (AMBBR) possess satisfying performance in wastewater treatment. However, no implementation of AMBBR in treating dairy wastewater has ever been reported. In this research, a series of experiments were conducted to evaluate the operational parameters of AMBBR. Subsequently, the performance of AMBBR in treating milk permeate wastewaters (COD up to 70 g.1-1) were studied and simulated by a mathematical model. Main conclusions are drawn as below : 1) Operational parameters had obvious impacts on AMBBR performance. AMBBR was efficient in treating milk permeate wastewaters. Results indicated that AMBBR worked better under mesophilic condition in treating high strength milk permeate wastewaters. It possessed satisfying performance which was comparative to other digester technologies; 2) Kinetic analysis is efficient in assessing the capability of AMBBR. It could be à simple and efficient measure for the assessment and prediction of AMBBR performance when mathematical modeling is not available. 3) a mathematical model of AMBBR was first developed and well validated. The AMBBR model was developed based on the ADMI (Anaerobic Digestion Model No.1) and other biofllm reactor models. The idea of model development could be referred to when carrying out modeling research on other biofilm reactors.CHAMBERY -BU Bourget (730512101) / SudocSudocFranceF
Molecular dynamics simulation of the nanofibrils formed by amyloid-based peptide amphiphiles
Time-dependent uptake and toxicity of nickel to Enchytraeus crypticus in the presence of humic acid and fulvic acid
The present study aimed to investigate the influence of different fractions of dissolved organic carbon (DOC) on the uptake and toxicity of nickel (Ni) in the soil invertebrate Enchytraeus crypticus after different exposure times. The addition of DOC as humic acid or fulvic acid significantly reduced Ni uptake by E. crypticus in the soil-solution test system. Median lethal effect concentrations were calculated based on total dissolved Ni concentrations (LC50[Ni]), free Ni ion activity (LC50{Ni2+}), and Ni body concentrations (LC50Body-Ni). The LC50[Ni] values increased with increasing DOC levels and decreased with exposure time (4, 7, and 10 d). Humic acid exerted a greater protective effect on Ni toxicity than fulvic acid, but the protective effects decreased with prolonged exposure time. The LC50{Ni2+} values also decreased with exposure time but were almost constant with variation in DOC levels, indicating that the protective effect of DOC is mainly through complexation with free Ni ions to reduce Ni bioavailability. The LC50Body-Ni value was independent of DOC concentration and exposure time, with an estimated overall value of 22.1 µg/g dry weight. The present study shows that body concentration could serve as an effective indicator for predicting Ni toxicity with variations in the exposure environment (e.g., DOC) and exposure time. Environ Toxicol Chem 2017;36:3019–3027
Inoculation of Prickly Pear Litter with Microbial Agents Promotes the Efficiency in Aerobic Composting
Prickly pear (Rosa roxburghii Tratt), a shrub mainly distributed in South China, is an economically essential plant for helping the local people out of poverty. To efficiently provide sufficient nutrients to the plant in the soil for the ecological cultivation of prickly pear, we studied the aerobic composting of a prickly pear litter with three agents, including AC (Bacillus natto, Bacillus sp., Actinomycetes sp., Saccharomyces sp., Trichoderma sp., Azotobacter sp., and Lactobacillus sp.), BC (Bacillus subtilis, Lactobacillaceae sp., Bacillus licheniformis, Saccharomyces sp., and Enterococcus faecalis), and CC (Bacillus sp., Actinomycetes sp., Lactobacillaceae sp., Saccharomyces sp., and Trichoderma sp.) and a control without microbial agents. The results show that the physicochemical and microbial traits of three resultant prickly pear composts were different after the inoculation with AC, BC, or CC. The pH values of three composts ranged from 8.0 to 8.5, and their conductivity values were between 1.6 and 1.9 mS/cm. The seed germination index of all three composts exceeded 70%. The contents of volatile solids and organic matter of the three composts both decreased significantly. The BC maximally increased the total N (18%) of the compost, whereas the CC maximally increased the total P (48%) and total K (38%) contents. Contents of available P and available K of the three composts increased significantly, and the available N content in compost after BC inoculation increased by 16%. The physicochemical features showed that three composts were non-hazardous to plants, and the microbial agents improved nutrient availability. The richness, Chao1, and Shannon index in the bacterial communities of three composts increased significantly. At the phylum level, Proteobacteria, Bacteroidetes, and Firmicutes bacterium became dominant in the three composts, whereas at the family level, Microscillaceae and A4b (phylum Chloroflexi) became the dominant groups. Abundant cellulose-degrading bacteria existed at the dominant phylum level, which promoted fiber degradation in composts. Organic matter and the available N content regulated the composting bacterium. The inoculants enhanced the efficiency of composting: agents B and C were more suitable exogenous inoculants for the composting of a prickly pear litter
- …