RESUMEN
The practical application of room-temperature sodium-sulfur (RT Na-S) batteries was severely hindered by inhomogeneous sodium deposition and notorious sodium polysulfides (NaPSs) shuttling. Herein, novel sodium thiotellurate (Na2TeS3) interfaces are constructed both on the cathode and anode for Na-S batteries to simultaneously address the Na dendritic growth and polysulfide shuttling. On the cathode side, a heterostructural sodium sulfide/sodium telluride embedded in a carbon matrix (Na2S/Na2Te@C) was rationally designed through a facile carbothermal reaction, where the Na2TeS3interface will be in-situ chemically obtained. Such an interface provides abundant electron/ion diffusion channels and ensures rich catalytic surfaces toward Na-S redox, which could significantly improve the utilization of active material and alleviate polysulfide shuttling in the cathode. On the anode side, the inevitable formation of soluble polytellurosulfides species will migrate on Na anode surface, finally constructing a compact and smooth solid-electrolyte Na2TeS3 interphase (SEI) layer. Such electrochemical formed Na2TeS3 interface can significantly enhance ionic transport and stabilize Na deposition, thus realizing dendrite-free Na-metal plating/stripping. Benefitting from these advantages, an anode-free cell fabricated with the Na2S/Na2Te@C cathode exhibits an ultrahigh initial discharge capacity of 634 mAh g-1 at 0.1 C, which could pave a new path to design high-performance cathodes for anode-free RT Na-S batteries.
RESUMEN
Experiments were conducted to investigate the alleviating effects of ZnO quantum dots (ZnO QDs) on salt stress in Salvia miltiorrhiza by comparing them with conventional ZnO nanoparticles (ZnO NPs). The results demonstrated that compared with salt stress alone, foliar application of ZnO QDs significantly improved the biomass as well as the total chlorophyll and carotenoids contents under salt stress. ZnO QDs reduced H2O2 and MDA levels, decreased non-enzymatic antioxidant (ASA and GSH) content, and improved antioxidant enzyme (POD, SOD, CAT, PAL, and PPO) activity under salt stress. Metal elemental analysis further demonstrated that the ZnO QDs markedly increased Zn and K contents while decreasing Na content, resulting in a lower Na/K ratio compared to salt stress alone. Finally, RNA sequencing results indicated that ZnO QDs primarily regulated genes associated with stress-responsive pathways, including plant hormone signal transduction, the MAPK signaling pathway, and metabolic-related pathways, thereby alleviating the adverse effects of salt stress. In comparison, ZnO NPs did not exhibit similar effects in terms of improving plant growth, enhancing the antioxidant system, or regulating stress-responsive genes under salt stress. These findings highlight the distinct advantages of ZnO QDs and suggest their potential as a valuable tool for mitigating salt stress in plants.
Asunto(s)
Salvia miltiorrhiza , Óxido de Zinc , Especies Reactivas de Oxígeno , Óxido de Zinc/toxicidad , Antioxidantes , Peróxido de HidrógenoRESUMEN
Paraquat (PQ) is a toxic herbicide to humans. Once absorbed, it accumulates in the lungs. PQ has been well documented that the generation of reactive oxygen species (ROS) is the main mechanism of its toxicity. Oxidative damage of PQ in lungs is represented as generation of cytotoxic and fibrotic mediators, interruption of epithelial and endothelial barriers, and inflammatory cell infiltration. No effective treatment for PQ toxicity is currently available. Several studies have shown that natural compounds (NCs) have the potential to alleviate PQ-induced pulmonary toxicity, due to their antioxidant and anti-inflammatory effects. NCs function as protective agents through stimulation of nuclear factor erythroid 2-related factor 2 (Nrf2)/antioxidant response element (ARE) signaling pathways. Elevation of Nrf2 levels leads to the expression of its downstream enzymes such as SOD, CAT, and HO-1. The hypothesized role of the Nrf2/ARE signaling pathway as the protective mechanism of NCs against PQ-induced pulmonary toxicity is reviewed.
Asunto(s)
Factor 2 Relacionado con NF-E2 , Paraquat , Humanos , Paraquat/toxicidad , Paraquat/metabolismo , Factor 2 Relacionado con NF-E2/genética , Factor 2 Relacionado con NF-E2/metabolismo , Factor 2 Relacionado con NF-E2/farmacología , Elementos de Respuesta Antioxidante , Pulmón , Estrés Oxidativo , Transducción de SeñalRESUMEN
Zearalenone (ZEN), a ubiquitous mycotoxin that widely occurs in grain and foodstuff may induce serious toxic effects after accumulation in vivo. Melanoidins (MLDs) have shown multiple bio-functional properties such as antioxidant, anti-bacterial and prebiotic activities. Black garlic exhibits several advantages over fresh garlic related to health improvement. In this study, the alleviative effects of black garlic MLDs on ZEN-induced toxicity and the potential mechanisms were studied using zebrafish embryonic developmental model. The results showed that MLDs restored the ZEN-induced adverse influences on zebrafish embryonic development, including delay in hatching time, morphological abnormality and the impairment of nervous development. Further studies showed that MLDs significantly inhibited the ZEN-induced production of reactive oxygen species (ROS) and enhanced the intrinsic antioxidant ability by increasing the activities of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) and catalase (CAT) and the content of glutathione (GSH). In addition, co-exposure of MLDs significantly inhibited the ZEN-stimulated cellular apoptosis in zebrafish larvae through down-regulation of pro-apoptotic genes of bax, caspase-3 and caspase-9 and up-regulation of anti-apoptotic gene bcl-2. Moreover, MLDs inhibited the in vivo accumulation of ZEN in zebrafish larvae. To sum up, MLDs attenuated the ZEN-induced zebrafish embryonic developmental toxicity through suppression of the oxidative stress and intervention on mitochondria apoptosis pathway as well as inhibiting the absorption of ZEN in zebrafish embryos/larvae. The results suggest that black garlic MLDs have potential to be used as a functional ingredient against the adverse effects of exogenous toxins.
Asunto(s)
Ajo , Zearalenona , Animales , Antioxidantes/farmacología , Zearalenona/toxicidad , Pez Cebra , Estrés Oxidativo , Glutatión , Desarrollo Embrionario , ApoptosisRESUMEN
Recombinant human metallothionein III (rh-MT-III) is a genetically engineered product produced by Escherichia coli fermentation technology. Its molecules contain abundant reducing sulfhydryl groups, which possess the ability to bind heavy metal ions. The present study was to evaluate the binding effects of rh-MT-III against copper and cadmium in vitro and to investigate the antioxidant activity of rh-MT-III using Caenorhabditis elegans in vivo. For in vitro experiments, the binding rates of copper and cadmium were 91.4% and 97.3% for rh-MT-III at a dosage of 200 µg/mL at 10 h, respectively. For in vivo assays, the oxidative stress induced by copper (CuSO4 , 10 µg/mL) and cadmium (CdCl2 , 10 µg/mL) was significantly reduced after 72 h of exposure to different doses of rh-MT-III (5-500 µg/mL), indicated by restoring locomotion behavior and growth, and reducing malondialdehyde and reactive oxygen species levels in C. elegans. Moreover, rh-MT-III decreased the deposition of lipofuscin and fat content, which could delay the progression of aging. In addition, rh-MT-III (500 µg/mL) promoted the up-regulation of Mtl-1 and Mtl-2 gene expression in C. elegans, which could enhance the resistance to oxidative stress by increasing the enzymatic activity of antioxidant defense system and scavenging free radicals. The results indicated that supplemental rh-MT-III could effectively protect C. elegans from heavy metal stress, providing an experimental basis for the future application and development of rh-MT-III.
Asunto(s)
Cadmio , Metales Pesados , Animales , Humanos , Cadmio/toxicidad , Cadmio/metabolismo , Cobre , Metalotioneína 3 , Caenorhabditis elegans , Metalotioneína/genética , Metalotioneína/metabolismo , Estrés Oxidativo , Antioxidantes/farmacología , Antioxidantes/metabolismoRESUMEN
In the present study, we explored whether magnetic iron oxide nanoparticles (MNPs-Fe3O4) can be used to alleviate the toxicity of 3-nitrophenol (3-NP) to rice (Oryza sativa L.) seedlings grown under hydroponic conditions. The results showed that 3-NP from 7 to 560 µM decreased the growth, photochemical activity of the photosystem II (PS II), and chlorophyll content of the seedlings in a concentration-dependent manner. In the presence of 3-NP, 2,000 mg L-1 MNPs-Fe3O4 were added to the growth medium as the absorbents of 3-NP and then were separated with a magnet. The emergence of MNPs-Fe3O4 effectively alleviated the negative effects of 3-NP on rice seedlings. In addition, the long-term presence of MNPs-Fe3O4 (from 100 to 2,000 mg L-1) in the growth medium enhanced the growth, production of reactive oxygen species (ROS), activities of antioxidant enzymes, photochemical activity of PS II, and chlorophyll content of the rice seedlings. These results suggest that MNPs-Fe3O4 could be used as potential additives to relieve the physiological toxicity of 3-NP to rice seedlings.
RESUMEN
Oysters are ecological engineers, and previous studies have examined their role as competent facilitators of ecological restoration. However, the decisive role of oysters in the aquatic environment is still debatable because oyster biodeposition (OBD) may also increase the nutrients enriched in sediments. In order to better interpret this problem, we sampled sediment cores from representative oyster culture areas and uncultured areas in Shenzhen Bay. The results have shown that the TOC (total organic carbon) and TN (total nitrogen) decreased significantly (p < 0.05) at the surface sediment layer (0-20-cm deep) and the sediment layer (20-40-cm deep) of the oyster site compared with the reference site. The decreased TOC and TN were also observed at 60- to 100-cm sediment depth in the oyster site. This indicated that the OBD significantly impacted the concentration of TOC and TN in the sediment. To confirm the alleviative role of OBD, we conducted stable isotope (δ13C and δ15N) analyses, which further demonstrated the presence of heavier and less lighter forms of organic carbon and nitrogen sediment. The surface sediment layer (0-20 cm) at the oyster site showed 8% more δ13C compared with the control site (p < 0.05), reflecting the reduction in the TOC. In order to reveal the potential microbial mechanisms involved in OBD, we performed a functional analysis using the Geochip5 advanced microarray technology. Regarding carbon metabolism, we observed that genes (encoding pullulanase, glucoamylase, exoglucanase, cellobiase, and xylanase) involved in the degradation of relatively labile C-based molecules (e.g., starch, cellulose, and hemicellulose) were highly represented in an experimental area (p < 0.05). In addition, microbes in the experimental area exhibited a greater capacity for degrading recalcitrant C (e.g., lignin), which involves glyoxal oxidase (glx), manganese peroxidase (mnp), and phenol oxidase. Among the genes controlling nitrogen metabolism, the genes involved in denitrification, assimilation, ammonification, and nitrification were differentially expressed compared with the control area. These results indicated that microbial metabolic roles might have enhanced the C/N-flux speed and reduced the overall nutrient status. We concluded that OBD alleviates sediment nutrient overload under oyster farming from a microbial ecological perspective in a rapidly urbanized coastal area.
RESUMEN
A large number of studies suggest that humor is associated with mental well-being and effective as a means of coping. However, it is less well-understood which mechanisms are effective for this particular function of humor. The present study examines whether processes of change of perspective, which are often regarded as constitutive for humor, could be an effective coping-factor when facing unrequited love as a specific psychological burden. In a questionnaire study, N = 148 persons aged 18-65 years (w = 96) with actual or past experiences of unrequited love reported on their subjective burden due to this experience, their self-esteem and satisfaction with life, two scales for humor (Multidimensional Sense of Humor Scale: MSHS, and a self-constructed scale: Humorous Change of Perspective, HCOP) and a coping scale which measure change of perspective in the confrontation with goal blockages (Flexible Goal Adjustment, FGA). Results indicated that the burden of unrequited love [operationalized objectively as actuality of experience (dichotomous) or subjectively as burden experienced] and both indicators of well-being were negatively associated. Multiple regression analyses showed that humor was a significant moderator of this relationship in nearly all combinations of operationalizations of humor and indicators of well-being: Higher levels of humor are associated with better well-being even when the perceived burden was high. In addition, the study examined whether the coping effect of humor can be partly or mainly attributed to the individual's capacity to perspective change as captured by FGA. When including this scale as a covariate in the regression models, the moderation effect for MSHS did not persist; however, for HCOP the moderation effect remained unchanged: the moderator effect of humorous change of perspective proved to be independent of FGA. Taken together the results suggest that perspective-changing skills play a significant role in the coping effect of humor in dealing with psychological burdens. However, depending on which humor facet is measured, the entailed perspective change may or may not appear to go beyond what the individual's FGA can account for. This suggests that the coping effect caused by humorous change of perspective includes aspects that are also discussed for other coping resources as well as its own, humor-specific aspects. Potential avenues for future studies are discussed both with respect to the necessity for replication and extension of the present study and to the determination of other potential alleviativing effects of other facets of humor.