خيارات البحث
النتائج 1411 - 1420 من 7,214
Multiple-stressor effects of ocean acidification, warming and predation risk cues on the early ontogeny of a rocky-shore keystone gastropod
2022
Manríquez, Patricio H. | Jara, María Elisa | González, Claudio P. | Jeno, Katherine | Domenici, P. (Paolo) | Watson, Sue-Ann | Duarte, Cristian | Brokordt, Katherina
To understand how climate change stressors might affect marine organisms and support adequate projections it is important to know how multiple stressors may be modulated by the presence of other species. We evaluated the direct effects of ocean warming (OW) and ocean acidification (OA) together with non-consumptive effects (NCEs) of the predatory crab Acanthocyclus hassleri on early ontogeny fitness-related traits of the commercially important rocky-shore keystone gastropod Concholepas concholepas. We measured the response of nine traits to these stressors at either the organismal level (survival, growth, feeding rates, tenacity, metabolic rate, calcification rate) or sub-organismal level (nutritional status, ATP-supplying capacity, stress condition). C. concholepas survival was not affected by any of the stressors. Feeding rates were not affected by OW or OA; however, they were reduced in the presence of crab NCEs compared with control conditions. Horizontal tenacity was affected by the OA × NCEs interaction; in the presence of NCEs, OA reduced tenacity. The routine metabolic rate, measured by oxygen consumption, increased significantly with OW. Nutritional status assessment determined that carbohydrate content was not affected by any of the stressors. However, protein content was affected by the OA × NCEs interaction; in the absence of NCEs, OA reduced protein levels. ATP-supplying capacity, measured by citrate synthase (CS) activity, and cellular stress condition (HSP70 expression) were reduced by OA, with reduction in CS activity found particularly at the high temperature. Our results indicate C. concholepas traits are affected by OA and OW and the effects are modulated by predator risk (NCEs). We conclude that some C. concholepas traits are resilient to climate stressors (survival, growth, horizontal tenacity and nutritional status) but others are affected by OW (metabolic rate), OA (ATP-supplying capacity, stress condition), and NCEs (feeding rate). The results suggest that these negative effects can adversely affect the associated community.
اظهر المزيد [+] اقل [-]Design of a dual responsive receptor with oxochromane hydrazide moiety to monitor toxic Hg2+ and Cd2+ ions: Usage on real samples and live cells
2022
Kavitha, Venkatachalam | Ramya, Mari | Viswanathamurthi, Periasamy | Haribabu, Jebiti | Echeverria, Cesar
In this work, we report a facile receptor OMB [N′,N”’-(3-((4-oxochroman-3-yl)methylene)pentane-2,4- diylidene)bis(4-methoxybenzohydrazide)] for the simultaneous detection of toxic analytes (Hg²⁺ and Cd²⁺ ions) in environment and biological samples. The receptor OMB exhibits an excellent selectivity and sensitivity which was determined using absorption and emission spectra. The receptor OMB shows rapid detection with lowest LOD (0.62 nM for Hg²⁺ ions and 0.77 nM for Cd²⁺ ions) and LOQ (2.08 nM for Hg²⁺ ions and 2.57 nM for Cd²⁺ ions) values. In addition, the receptor OMB exhibits 1:1 binding stoichiometry towards Hg²⁺ and Cd²⁺ ions with binding constant values of 5.5 × 10⁶ M⁻¹ and 4.6 × 10⁶ M⁻¹. Moreover, the synthesized receptor OMB possess ability to detect these analytes (Hg²⁺ and Cd²⁺ ions) in realistic samples (food and water) which was recognized using photoluminescence spectroscopy technique. In addition, the receptor OMB is also utilized to detect both the analytes in live HeLa cells. Thus, the overall results indicate that the receptor OMB was more suitable to detect the toxic analytes (Hg²⁺ and Cd²⁺ ions) present in the environment.
اظهر المزيد [+] اقل [-]Comprehensive assessment of nitrous oxide emissions and mitigation potentials across European peatlands
2022
Lin, Fei | Zuo, Hongchao | Ma, Xiaohong | Ma, Lei
European natural peatlands have undergone long-term anthropogenic drainage activities that have severely decreased their functions, such as carbon sequestration. Recent rewetting has been conducted to restore the ecosystem services of peatlands and mitigate the emissions of potent greenhouse gases such as nitrous oxide (N₂O). However, the magnitudes and spatial patterns of annual N₂O fluxes and their mitigation potentials across European peatlands remain unknown. Here, we synthesized 492 annual N₂O flux data points from 77 in situ studies across European peatlands and found that the soil annual N₂O fluxes varied extensively from −1.08 to 33.40 kg N₂O–N ha⁻¹ yr⁻¹; these results were significantly and interactively (P < 0.05) affected by the peatland status, climatic regime and nutrient supply type. Drainage significantly (P < 0.05) stimulated soil N₂O emissions from natural minerotrophic rather than ombrotrophic peatlands, regardless of the climatic regime. Similarly, rewetting significantly (P < 0.05) reduced soil N₂O emissions from drained minerotrophic rather than ombrotrophic peatlands, demonstrating that the high N₂O emissions were driven by a simultaneous decline in the water table depth and increase in the soil nitrogen (N) availability. Magnitudes of the increases or decreases in N₂O emissions due to drainage or rewetting were also significantly influenced by the land-use and drainage history before rewetting and in the years following drainage/rewetting, respectively. The estimated annual mean N₂O emission total was found to be 90.42 (95% confidence interval: 64.49–122.57) Gg N₂O–N in 2020 from European peatlands. Scenario analysis showed that drained peatlands should be rewetted expeditiously; postponing rewetting would cause larger emissions from continued N₂O emissions from drained peatlands. Fully rewetting the drained peatlands used for forestry and peat extraction and partially rewetting those used for agriculture and grassland comprise a strategy for mitigating drained peatland N₂O emissions without compromising food security.
اظهر المزيد [+] اقل [-]Prevention and control of coronavirus disease 2019 (COVID-19) in public places
2022
Pan, Lijun | Wang, Jiao | Wang, Xianliang | Ji, John S. | Ye, Dan | Shen, Jin | Li, Li | Liu, Hang | Zhang, Liubo | Shi, Xiaoming | Wang, Lin
Public places favor the transmission of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) due to dense population, large personal mobility, and higher contact opportunities. In order to protect the health of general public in operating public places during COVID-19 pandemic, this study proposed general precautions and control strategies from perspective of operation management, social distancing, cleaning and disinfection, and personal protection. In addition, with regard of risk level, specific precautions and control strategies were proposed for living service places, outdoor places, and confined places. The comprehensive application of above recommendations could effectively interrupt the spread of COVID-19, and protect the health of general public in public places.This study proposed general and specific precautions and control strategies in public places during COVID-19, and suggested further improvement of pandemic response.
اظهر المزيد [+] اقل [-]Earthworm half-pipe assay: A new alternative in vivo skin corrosion test using invertebrates
2022
Kwak, Jin Il | Kim, Haemi | An, Youn-Joo
As a result of the efforts to introduce the principle of the 3Rs (replacement, reduction, and refinement) into animal testing, alternative in vitro skin corrosion test methods have been developed and standardized globally. However, alternative in vitro skin corrosion test methods have some limitations in terms of the use of humanely killed rats or commercial models and kits. The present study focused on the applicability of invertebrates as alternative in vivo skin models. Even though earthworm skin comprises the same biomolecules as human skin, the possibility of using earthworm skin as an alternative for skin testing remains unexplored. In this study, we developed a half-pipe tool for earthworm skin corrosion testing and optimized the test protocol. Subsequently, the applicability of the earthworm half-pipe assay for corrosion testing with six chemicals, including inorganic acids, organic acids, and alkalis, was investigated using stereomicroscopy and electron microscopy. It was observed that the specific concentrations for earthworm skin corrosion were lower than those for animal or in vitro tests. Therefore, the sensitivity of the earthworm half-pipe assay indicates that it could be useful as a screening tool before conducting in vivo animal tests or in vitro skin tests. This new method can contribute to research on alternative skin corrosion tests by reducing ethical issues, time, and cost while achieving effective results.
اظهر المزيد [+] اقل [-]Ambient temperature structures the gut microbiota of zebrafish to impact the response to radioactive pollution
2022
Wang, Bin | Zhang, Shu-qin | Dong, Jia-li | Li, Yuan | Jin, Yu-xiao | Xiao, Hui-wen | Wang, Hai-chao | Fan, Sai-jun | Cui, Ming
Potential nuclear accidents propel serious environmental pollution, and the resultant radionuclide release devastates severely the environment severely and threatens aquatic organism survival. Likewise, ongoing climate change coupled with the gradual increase in global surface temperatures can also adversely impact the aquatic ecosystems. In the present study, we preconditioned zebrafish (Danio rerio) at three different temperatures (18 °C, 26 °C and 34 °C) to investigate the effects of a temperature profile on their radiosensitivity (exposure to 20 Gy of gamma rays) to identify the potential biochemical mechanism responsible for influencing radiosensitivity. We found that preconditioning of zebrafish at different temperatures moulded specific gut microbiota configurations and impacted hepatic glycometabolism and sensitivity to subsequent radiation. Following antibiotic treatment to reduce gut bacteria, these observed differences in the expression of hepatic glycometabolism-related genes and radiation-induced intestinal toxicity were minimal, supporting the hypothesis that the gut bacteria reshaped by different ambient temperatures might be the key modulators of hepatic functions and radiosensitivity in zebrafish. Together, our findings provide novel insights into the connection of radiation injuries with temperature alterations in fish, and suggest that maintaining the stability of gram-positive bacteria may be efficacious to protect aquatic organisms against short or long-term radioactive contamination in the context of global climate change.
اظهر المزيد [+] اقل [-]Enhanced immobilization of cadmium and lead adsorbed on crop straw biochars by simulated aging processes
2022
Yang, Kai | Wang, Xilong | Cheng, Hefa | Tao, Shu
Aging is an important natural process affecting the physiochemical properties of biochar, while mechanistic understanding of its effect on the adsorbed heavy metals is still lacking. After adsorption of Cd²⁺ and Pb²⁺, biochars produced from wheat straw (WS) and maize straw (MS) at 300 and 500 °C (denoted as WS300, WS500, MS300, and MS500, respectively) were subjected to 60 cycles of wet–dry or freeze–thaw aging. The results showed that simulated aging treatment transformed the Cd²⁺ and Pb²⁺ adsorbed on the low-temperature biochars from the readily and potentially bioavailable fractions into the non-bioavailable one, while the fractionation of Cd²⁺ and Pb²⁺ adsorbed on WS500 and Pb²⁺ on MS500 barely changed. Spectroscopic characterization revealed that simulated aging enhanced the complexation of Cd²⁺ and precipitation of Pb²⁺ on the biochars. These findings suggest that heavy metals could be effectively immobilized on low-temperature biochars amended to contaminated soils in the long term.
اظهر المزيد [+] اقل [-]Accumulation of chromium in plants and its repercussion in animals and humans
2022
Kapoor, Riti Thapar | Bani Mfarrej, Manar Fawzi | Alam, Pravej | Rinklebe, Jörg | Ahmad, Parvaiz
The untreated effluents released from industrial operations have adverse impacts on human health, environment and socio-economic aspects. Environmental pollution due to chromium is adversely affecting our natural resources and ecosystem. Chromium is hazardous carcinogenic element released from spontaneous activities and industrial procedures. Chromium toxicity, mobility and bioavailability depend mainly on its speciation. Chromium mainly exists in two forms, first as an immobile, less soluble trivalent chromium [Cr(III)] species under reducing conditions whereas hexavalent chromium [Cr(VI)] as a mobile, toxic and bioavailable species under oxidizing conditions. Hexavalent chromium is more pernicious in comparison to trivalent form. Chromium negatively affects crop growth, total yield and grain quality. Exposure of chromium even at low concentration enhances its accretion in cells of human-beings and animals which may show detrimental health effects. Many techniques have been utilized for the elimination of chromium. The selection of the green and cost-efficient technology for treatment of industrial effluent is an arduous task. The present review highlights the problems associated with chromium pollution and need of its immediate elimination by suitable remediation strategies. Further, investigations are required to fill the gaps to overcome the problem of chromium contamination and implementation of sustainable remediation strategies with their real-time applicability on the contaminated sites.
اظهر المزيد [+] اقل [-]Restriction of biosolids returning to land: Fate of antibiotic resistance genes in soils after long-term biosolids application
2022
Qin, Xuechao | Zhai, Limei | Khoshnevisan, Benyamin | Pan, Junting | Liu, Hongbin
Although the utilization of biosolids in agricultural lands is widely considered as an effective way to improve resource reuse, the presence of antibiotic resistance genes (ARGs) severely restricts biosolids returning to fields. A 12-year long-term experiment with different biosolids application rates (from 0 to 36 t ha⁻¹ yr⁻¹) was conducted to study the effect of biosolids application on shaping ARGs in soil. Biosolids application significantly increased ARGs abundance in the soil, except for MBS treatment (9 t ha⁻¹ yr⁻¹ biosolids application). The abundance of ARGs in soil did not increase linearly with the dose of biosolids applied, but they were significantly (P < 0.05) positively correlated. A total of 173 subtypes were detected, among them mobile genetic elements (MGEs), aminoglycoside, and multidrug resistance genes were the most dominant types. Except for MBS treatment, most of the ARGs detected were enriched in amended soils after long-term continuous biosolids application. Specifically, tetPA, sul1, mefA, and IS6100 were highly enriched in all amended soils. In addition, biosolids application increased soil nutrients and heavy metals, and changed the soil microbial community, all of which affected ARGs formation. But MGEs may be a greater factor for shaping ARGs profiles than soil properties. Overall, controlling the rate of biosolid application is the key to reducing the accumulation and horizontal transfer of ARGs in soils.
اظهر المزيد [+] اقل [-]Effective Sb(V) removal from aqueous solution using phosphogypsum-modified biochar
2022
Li, Ling | Liao, Lu | Wang, Bing | Li, Wei | Liu, Taoze | Wu, Pan | Xu, Qingya | Liu, Shirong
Antimonate is the dominant form of antimony (Sb) in Sb mine water. The treatment of high-Sb mine water essentially reduces the discharge of antimonate oxyanions ([Sb(OH)₆]⁻) in it. Biochar obtained from phosphogypsum-modified anaerobic digested distillers’ grain (PADC) can effectively adsorb antimonate from water. In this work, using batch adsorption experiments, mathematical models, and characterization methods, the mechanism of Sb(V) adsorption by PADC was studied. Compared with pristine biochar, PADC biochar showed abundant lamellar and vesicular structures with significant calcium ion loading on the surface. The kinetics data of the adsorption of Sb(V) on the PADC biochar followed the Elovich equation (R² = 0.992), indicating that heterogeneous adsorption had occurred. The results also showed that intraparticle diffusion played an important role in controlling Sb(V) adsorption by PADC biochar. The Redlich–Peterson model best fit the Sb(V) adsorption isotherm (R² = 0.997), indicating that the adsorption was a combination of the Langmuir and Freundlich models. The maximum adsorption capacity of PADC biochar for Sb(V) is 8123 mg/kg, which is more than twice that of the pristine biochar (3487 mg/kg) and is sufficient for Sb(V) treatment in most mine water. Fourier transform infrared (FTIR) spectra, X-ray photoelectron spectroscopy (XPS), X-ray diffractometry (XRD), and Transmission electron microscopy with energy dispersive X-ray spectroscopy (TEM-EDS) analyses revealed that the dominant mechanism of Sb(V) removal by PADC biochar was the formation of Ca–O–Sb complexes or amorphous surface precipitation as well as electrostatic adsorption. This work demonstrated the potential of PADC biochar in the treatment of Sb-contaminated mine water.
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