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Variety-dependent responses of rice plants with differential cadmium accumulating capacity to cadmium telluride quantum dots (CdTe QDs): Cadmium uptake, antioxidative enzyme activity, and gene expression
摘要： The excess release of engineered nanomaterials into farmland poses a serious threat to food security. Although rice varieties exhibit substantial variation in cadmium accumulation, their responses to Cd-based nanoparticles are largely unknown. In this work, we investigated the accumulation of cadmium telluride quantum dots (CdTe QDs at 0.5, 1.0, 2.5, 5.0 mg-Cd/L) in two rice varieties with different Cd accumulation capacity. It was found that 5.0 mg-Cd/L of CdTe QDs had minor growth inhibition to the high-Cd-accumulating variety (T705) relative to the low-Cd-accumulating variety (X24) after 7-day exposure. The two rice varieties had comparable Cd content in roots; however, T705 exhibited higher Cd content in shoots than X24. Transmission electron and confocal laser scanning microscopic observations demonstrated that more CdTe QDs can be transported and accumulated from roots to shoots in T705. The activities and gene expression of antioxidative enzymes in leaves of T705 increased more significantly than those of X24. Our findings for the first time validated that Cd accumulation divergence exists in different rice varieties when they are exposed to Cd-based QDs, the genetic basis for which needs to be further examined.
关键词： Gene expression,Antioxidant enzyme activity,Cadmium accumulation,Rice variety,Cadmium telluride quantum dots
更新于2025-09-19 17:13:59
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Biomimetic approach to inhibition of photooxidation in organic solar cells using beta-carotene as an additive
摘要： Recent efficiency records of organic photovoltaics (OPV) highlight stability as a limiting weakness. Incorporation of stabilizers is a desirable approach for inhibiting degradation - it is inexpensive and readily up-scalable. However, to date, such additives have had limited success. We show that β-carotene (BC), an inexpensive and green, naturally-occurring antioxidant, dramatically improves OPV stability. When compared to non-stabilized reference devices, the accumulated power generation in presence of BC of PTB7:[70]PCBM devices increases by an impressive factor of 6, due to stabilization of both the burn-in and the lifetime, and by a factor of 21 for P3HT:[60]PCBM devices, owing to a longer lifetime. Using electron spin resonance and time-resolved near-IR emission spectroscopies, we probed radical and singlet oxygen concentrations. We demonstrate that singlet oxygen sensitized by [70]PCBM causes the “burn-in” of PTB7:[70]PCBM devices, and that BC effectively mitigates it. Our results provide an effective solution to the problem that currently limits widespread use of OPV.
关键词： singlet oxygen,Organic solar cells,burn-in,antioxidant,stability
更新于2025-09-19 17:13:59
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Graphene Quantum Dots Induce Autophagy and Reveal Protection Against Hydrogen Peroxide-Induced Oxidative Stress Injury
摘要： As the zero-dimension nanomaterials, graphene quantum dots (GQDs) have excellent characteristics of graphene as well as photoluminescence (PL) features that ordinary graphene does not possess for its virtue of quantum confinement effect and boundary effect, and attract lots of researchers interested in the field of biomedical applications. In this work, we found GQDs can be internalized into SGC-7901 cells, and the labeled cells exhibited bright yellow fluorescence in the form of aggregated dots. Meanwhile, GQDs effectively mitigated the injury hydrogen peroxide (H2O2)-induced in SGC-7901 cells including cytotoxicity and apoptosis. While H2O2 exposure increased ROS and decreased mitochondrial membrane potential, it could be arrested by GQDs. Furthermore, GQDs showed protective effects against the reduction of the ratio of mitochondrial apoptosis-related proteins Bcl-2/ Bax in SGC-7901 cells. Our works revealed that GQDs had the antioxidant ability against oxidative stress, which meant they had the potential to be an antioxidants. Besides, GQDs increased the level of autophagy-related protein LC3-II and induced autophagic structure observed via TEM, and subsequent the results of LC3 turnover and p62 degradation demonstrated GQDs treatment led to the activation of autophagic flux. Ultimately, GQDs were found to affect autophagy through the mTOR signaling pathway.
关键词： graphene quantum dots,apoptosis,antioxidant,oxidative stress,autophagy
更新于2025-09-16 10:30:52
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Enhanced performance of tin-based perovskite solar cells induced by an ammonium hypophosphite additive
摘要： As a promising lead-free perovskite candidate, tin-based halide perovskites such as FASnI3 have attracted extensive attention recently in photovoltaic applications. However, the relatively low e?ciency and poor long-term stability of tin-based perovskite solar cells hinder their practical applications. Here, ammonium hypophosphite is introduced into the FASnI3 perovskite precursor to suppress the oxidation of Sn2+ and assist the growth of perovskite grains, leading to improved perovskite ?lm quality and reduced defect density, and consequently, the device e?ciency and open circuit voltage are substantially improved. More importantly, the solar cells exhibit pronounced enhancement of the long-term stability. This work provides a facile approach for improving the performance of tin-based perovskite solar cells by introducing ammonium hypophosphite as an antioxidant agent in the precursor solution.
关键词： ammonium hypophosphite,tin-based perovskite,solar cells,photovoltaic performance,antioxidant
更新于2025-09-16 10:30:52
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White and red LEDs as two-phase batch for cyanobacterial pigments production
摘要： Carotenoids and phycobiliproteins have a high economic value, due to their wide range of biological and industrial applications. The implementation of strategies to increase their production, such as the application of two-phase light cultivation systems, can stimulate pigments production, increasing economic turnover. In this sense, Cyanobium sp. was grown in seven different two-phase white/red cultivation arrangements, varying the time of each light from 0 to 21 days. Biomass, photosynthetic activity, pigments profile and antioxidant capacity were measured along time. Red light increased photosynthetic activity and pigments content (ca. 1.8-fold), and the use of a two-phase cultivation system generally raised bioactivity and production of phytochemicals. Among the studied, the optimal cultivation condition was found with 10 days of white followed by 4 days of red light. The optimized growth led to a productivity of 137.4 ± 0.8 mg.L-1.d-1 of biomass, 17.0 ± 0.2 mg.L-1.d-1 of total phycobiliproteins and 4.5 ± 0.2 mg.L-1.d-1 of carotenoids
关键词： cyanobacteria,carotenoids,phycobiliproteins,antioxidant capacity,light-emitting diode
更新于2025-09-16 10:30:52
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Antioxidant Activity of Graphene Quantum Dots Prepared in Different Electrolyte Environments
摘要： Antioxidants can reduce or inhibit damage such as oxidative decay caused by elevated levels of free radicals. Therefore, pursuing antioxidants with excellent properties has attracted more and more attention. Graphene quantum dots (GQDs) are considered a promising material because of their good free radical scavenging activity, low toxicity, and excellent water solubility. However, their scavenging e?ciency, antioxidant mechanism, and e?ective control methods need to be improved. Herein, in order to further reveal the antioxidant mechanism of GQDs, the role of electrolytes in improving the antioxidant activity of GQDs is explored. In addition, 1,1-diphenyl-2-picrazine (DPPH·), hydroxyl (·OH), and superoxide (·O2) free radicals are used to evaluate the antioxidant activity of the as-prepared GQDs. Combined with transmission electron microscopy, Fourier-transform infrared spectroscopy, Raman spectroscopy, and cyclic volt–ampere characteristic curves, the e?ects of an electrolytic environment on the surface functional groups, charge transfer capability, and defect states of GQDs are obtained. The antioxidant mechanism of GQDs and how to improve their antioxidant activity are further elucidated.
关键词： antioxidant,free radical scavenging,electrochemical method,GQDs
更新于2025-09-12 10:27:22
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Color Development and Phytochemical Changes in Mature Green Chili (Capsicum annuum L.) Exposed to Red and Blue Light-Emitting Diodes
摘要： Exposure of mature green ‘Takanotsume’ chili fruit to blue and red light-emitting diodes (LEDs) was investigated. The red LED accelerated the red color development of chili as indicated by higher a* and chroma values, as well as lower hue angle and total chlorophyll compared to the blue LED and darkness (control). These were linked to increases in β-carotene, free-capsanthin and total carotenoids. The carotenoid biosynthesis-related genes: lycopene-β-cyclase (Lcyb), β-carotene hydroxylase (CrtZ), and capsanthin/capsolubin synthase (Ccs) were up-regulated by the red LED after 2 days of the experiment. The blue LED was more effective in increasing the expression of the phytoene synthase (Psy) gene at day 1 of experiment. The total phenolic, vitamin C content, and antioxidant capacity were also higher in the blue LED-treated chili. Results suggest that the responses of each carotenoid-related gene to the light wavelengths and the accumulation of phytochemicals are specific characteristics of this chili cultivar.
关键词： phytochemicals,carotenoids,LEDs,carotenoid biosynthesis,mature green chili,Antioxidant
更新于2025-09-12 10:27:22
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Blue LED light irradiation enhances L-ascorbic acid content while reducing reactive oxygen species accumulation in Chinese cabbage seedlings
摘要： Chinese cabbage is one of the most representative vegetables in Southeast Asia and a main source of L-Ascorbic acid (AsA) for the human diet. In this study, we applied di?erent light qualities (red, blue and white) supported by light-emitting diode (LED) device to enhance AsA content in Chinese cabbage (Brassica rapa ssp. pekinensis) seedlings. Based on our results, blue LED light irradiation with an intensity of 125 μmol m?2s?1 increased the AsA content of ?ve-day-grown Chinese cabbage seedlings by 40% compared with white LED light irradiation. Accordingly, blue LED light irradiation induced expression of the AsA biosynthetic- and recycling-related genes. Interestingly, the reactive oxygen species (ROS) content of Chinese cabbage seedlings was decreased by blue LED light irradiation. In addition, the technology improving AsA content by blue LED light irradiation was applicable to other edible vegetable sprouts as well as to Chinese cabbage sprouts. Conclusively, our report introduces a source technology for arti?cially improving the AsA content of Chinese cabbage seedlings by applying blue LED light, which implies that application of certain types of LED light enables on-purpose cultivation of crops.
关键词： Chinese cabbage,Blue light,Ascorbic acid (AsA),Light-emitting diode (LED),Antioxidant
更新于2025-09-12 10:27:22
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Beyond DPPH: Use of Fluorescence-Enabled Inhibited Autoxidation to Predict Oxidative Cell Death Rescue
摘要： Shah et al. develop a fluorescence-enabled inhibited autoxidation (FENIX) approach that permits accurate quantitation of radical-trapping antioxidant activity in phospholipid bilayers. The methodology is far superior to existing assays (e.g., DPPH) and enables reliable prediction of the anti-ferroptotic potency of redox-active compounds. The approach is easily amenable to high-throughput screening.
关键词： anti-ferroptotic potency,high-throughput screening,radical-trapping antioxidant activity,DPPH assay,phospholipid bilayers,FENIX
更新于2025-09-12 10:27:22
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Determination of Vitamin B2 Content in Black, Green, Sage, and Rosemary Tea Infusions by Capillary Electrophoresis with Laser-Induced Fluorescence Detection
摘要： Vitamin B2, also known as ribo?avin (RF) is an essential micronutrient for human health and must be obtained from dietary sources. Plants biosynthesize ribo?avin and are important dietary sources of vitamin B2 for humans. Our present study reports sensitive detection of vitamin B2 in widely consumed tea infusions, namely black, green, sage and rosemary tea infusions, by a capillary electrophoresis method combined with laser induced ?uorescence detection. Moreover, the correlation between the vitamin B2 content of tea plants with their total phenolics (TPs) and antioxidant capacity are evaluated in this study. Whereas green teas have the highest TPs and antioxidant capacity, the highest RF content is in sage infusions. The RF content ranged between 0.34 and 10.36 μg/g for all tea samples studied. Comparing the RF content of tea samples found in this study to the RF content of known RF sources, tea infusions are proposed as important dietary sources of vitamin B2.
关键词： tea,Salvia of?cinalis,antioxidant,Rosmarinus of?cinalis,total phenolic
更新于2025-09-11 14:15:04