Coumarin (1,2-benzopyrone), an aromatic oxygen-containing heterocyclic compound, has various biological functions. Previous studies have demonstrated that coumarin and its derivatives exhibit ...antifungal activity against
. In this study, we investigated the exact mechanism by which coumarin works against this fungus using Annexin V-FITC/PI double staining, TUNEL assay, and DAPI staining, and found that it induced a series of apoptotic features, including phosphatidylserine (PS) externalization, DNA fragmentation, and nuclear condensation. Moreover, it also induced cytochrome
release from the mitochondria to the cytoplasm and metacaspase activation. Further study revealed that intracellular reactive oxygen species (ROS) levels were increased and mitochondrial functions, such as mitochondrial membrane potential and mitochondrial morphology, were altered after treatment with coumarin. Cytosolic and mitochondrial Ca
levels were also found to be elevated. However, pretreatment with ruthenium red (RR), a known mitochondrial Ca
channel inhibitor, attenuated coumarin-mediated DNA fragmentation and metacaspase activity, indicating that the coumarin-induced
apoptosis is associated with mitochondrial Ca
influx. Finally, coumarin was found to be low-toxic and effective in prolonging the survival of
-infected mice. This study highlights the antifungal activity and mechanism of coumarin against
and provides a potential treatment strategy for
infection.
Soil quality is essential for maintaining the sustainability of agroecosystems, especially under intensified agricultural activities and rapid land use change. The sampling and analysis of soil ...properties to assess the status of agricultural land is widely practiced at the field scale; however, the spatiotemporal variations in soil quality and its influencing factors at a large scale remain unclear. Here, we quantified spatiotemporal variations in the soil quality of agricultural land in China during 1980–2018 by using the soil quality index (SQI) area approach, and explored the drivers with a geographical detector method. The results showed that the distribution of the SQI in the two periods had a similar spatial trend, except for that in the southwest (SWC), and the SQI decreased from north to south regardless of land use type. The soil quality of woodland was comparatively good with mean SQI values of 1.55 and 1.53 in 1980 and 2018, respectively, followed by that in grassland and cropland. Soil organic carbon, total nitrogen and cation exchange capacity were the dominant soil indicators explaining the spatial heterogeneity of the SQI in all land uses; moreover, climatic factors (i.e., temperature and precipitation) showed a stronger effect on woodland. From 1980 to 2018, the SQI of grassland decreased deeply, especially in the SWC, which showed a severe decline of 12.5 %. The changes in precipitation and temperature were identified as the largest drivers of SQI temporal changes in woodland and grassland, respectively, and their interaction achieved the highest impact across all land uses. In addition, the bidirectional conversion between cropland and grassland in recent decades has aggravated the deterioration of soil quality. Therefore, quantifying spatiotemporal changes in the SQI and elucidating the role of factors influencing soil quality in agroecosystems can provide a guide for designing sustainable agriculture policies and improving environmental quality.
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•Soil quality of agricultural land in China changed greatly during 1980–2018.•Drivers affecting the spatiotemporal dynamics of the SQI were explored.•Climatic factors best explained the spatial variation in the SQI in woodland.•Precipitation and temperature interaction dominated SQI changes in all land uses.•Land use conversion aggravated the recent deterioration of the grassland SQI.
As an emerging harvester for mechanical energy, the ultrahigh and unstable voltage and low surface charge density have limited the practical applications of triboelectric nanogenerators (TENGs). ...Herein, a charge pumping technology is demonstrated for sliding‐mode TENG with voltage stabilization and enhanced current by utilizing unfixed shuttling charges to generate electricity. A voltage booster circuit and a switch circuit are incorporated to elevate charge density and reduce high output voltage, respectively. With this technology, output electricity can be doubled owing to its two conduction domains and the voltage is outputted in an approximately direct‐current form. Moreover, a reduction of 63.9% in voltage fluctuation and an elevation of 43.4% in current are achieved, and an ultrahigh charge density is obtained up to 1328 µC m−2. This sliding charge pump technology is fundamentally different from traditional ones, providing insight into enhancing the output of TENG and offering a new high‐output energy harvesting strategy.
A novel charge pumping technology for a sliding‐mode triboelectric nanogenerator (CPS‐TENG) is proposed for voltage stabilization and current boosting. The CPS‐TENG utilizes the charge shuttling between main TENG and a capacitor to generate electricity. The current from a pump TENG is rectified to inject charges into a CPS‐TENG, high enough to light ultra‐violet tubes for the visualization of fluorescent ink.
To investigate the underlying molecular mechanism of threonine (Thr) regulation on the development of breast muscle in Pekin ducks, 240 male Pekin ducks at 1 d of age were fed a Thr deficiency diet ...(Thr-D), Thr sufficiency diet (Thr-S), or Thr excess diet (Thr-E) for 21 d. The results showed that Thr-D reduced body weight (BW), average weight gain (ADG), and average feed intake (ADFI), and increased the feed/gain (F/G) in Pekin ducks (P < 0.05), and Thr-E did not affect BW, ADG, ADFI, or F/G (P > 0.05), compared with Thr-S. The diameter and cross-sectional area of the breast muscle fibers in the Thr-S group were larger than those in the Thr-D group (P < 0.05). RNA sequencing revealed 1,300 differential expressed genes (DEGs) between the Thr-D and Thr-S groups, of which 625 were upregulated and 675 were downregulated by Thr-D. KEGG analysis showed that the upregulated genes were enriched in mTOR, FoxO, Wnt, fat digestion and absorption, and other signaling pathways. The downregulated genes were enriched in the MAPK signaling, glycolysis/gluconeogenesis, adipocytokine signaling, and biosynthesis of unsaturated fatty acids signaling pathways. The genes of Wnt family member 3a (Wnt3a), myogenin, myozenin 2, and insulin like growth factor 2 mRNA binding protein were upregulated, and platelet derived growth factor subunit B, PDGF receptor beta and Wnt4 were downregulated by Thr deficiency, which involving in muscle development. Our findings indicated that Thr increased breast fiber size, perhaps because Thr affected the proliferation and differentiation of satellite cells in breast muscle of ducks after hatch. Our results provide novel insights into new understanding of the molecular mechanisms underlying breast muscle development in ducks subjected to dietary Thr.
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•Grassland degradation is concentrated in the central and southern of the Tibetan Plateau.•Grassland degradation accounted for about 12.63% of the grassland area.•Human activities ...significantly influenced grassland degradation.•Topography indirectly slows down grassland degradation by limiting human activities.
The Tibetan Plateau (TP), a vital region for terrestrial ecosystem services and biodiversity, is facing severe grassland degradation influenced by multiple factors. However, it remains unclear how several influential factors interactively influence grassland degradation. Here, we used five land cover products and six vegetation indexes to quantify grassland degradation on the TP. We then applied structural equation modeling (SEM) to quantitatively assess multiple factors and interactions affecting grassland degradation. We found that grassland degradation on the TP was mainly concentrated in the central and southern regions which were under high pressure from human activities, with the area of 325,430 km2, accounting for about 12.63% of the total grassland area on the TP during 2000–2020. The factors such as overgrazing, climate change, and human activities have contributed to the grassland degradation on the TP. Moreover, we found that there is a complex and interrelated relationship between these factors and that addressing one factor alone is unlikely to solve the problem of grassland degradation. Human activities significantly (p < 0.05) influenced grassland degradation on the TP, while climate factors had a greater direct effect (0.384) compared to soil factors (0.298) and human activities (0.263). Soil factors, on the other hand, had a greater total effect (0.388) than human activities (0.263) and climate factors (0.161). The topography of the TP played an indirect role (−0.4) in slowing down the degradation of grasslands by significantly (P < 0.05) affecting human activities and climate. In order to fully understand the truth about grassland degradation and to avoid further grassland degradation, it is necessary to consider multiple influencing factors and their interactions.
Triboelectric nanogenerator (TENG) is a natural high voltage and low frequency power source by transferring ambient motion into electrical energy. To improve the output performance of the rotary ...freestanding TENG (RF-TENG) with the capacitive impedance load used in high voltage field, where the dielectric barrier discharge (DBD) microplasma as an example, an efficiently and effectively electrical analysis for the whole system is explored. Firstly, a simply experimental method with 99% reliability shows the root mean square (RMS) of open-circuit voltage in our RF-TENG is around 3500-4000V and the internal capacitance is 100–130 pF with frequency from 10 Hz to 30 Hz. Then, the experiments of DBD microplasma directly driven by the RF-TENG under different conditions have been conducted and the results fit well with the simulation in discharge current and voltage. Moreover, a 10–30 folds jumping of the discharge current and real-time power have been observed. Finally, by increasing the input frequency or decreasing gas thickness, the discharge intensity and efficiency have been enhanced, meanwhile over 10 times increase on discharge power (RMS) has been achieved. This work will not only help to understand the characteristics of the microplasma at low frequency (<50 Hz) but also benefit the further researches on the directly high voltage application of the RF-TENG.
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•To improve the output performance of the rotary freestanding TENG with the capacitive impedance load used in high voltage field, where the dielectric barrier discharge (DBD) microplasma (<50 Hz) as an example, an efficiently and effectively electrical analysis for the whole system is explored, resulting in ten times enhancement for the discharge power (RMS).•A simple, accurate and effective method based on the calibrated resistances and capacitances is applied to figure out the exact values of the OC voltage (RMS) and internal capacitance.
Encapsulation of active ingredients into intelligent response controlled release carriers has been recognized as a promising approach to enhance the utilization efficiency and reduce the ...environmental risks of pesticides. In this work, an intelligent redox and pectinase dual stimuli-responsive pesticide delivery system was constructed by bonding pectin with metal-organic frameworks (FeMOF nanoparticles) which were loaded with pyraclostrobin (PYR@FeMOF-pectin nanoparticles). The successful fabrication of PYR@FeMOF-pectin nanoparticles was proved by a series of physicochemical characterizations. The results indicated that the loading capacity of PYR@FeMOF-pectin nanoparticles for pyraclostrobin was approximately 20.6%. The pectin covered on the surface of PYR@FeMOF nanoparticles could protect pyraclostrobin from photolysis and improve their spreadability on rice blades effectively. Different biological stimuli associated with Magnaporthe oryzae could trigger the release of pyraclostrobin from the pesticide-loaded core-shell nanoparticles, resulting in the death of pathogens. The bioactivity survey determined that PYR@FeMOF-pectin nanoparticles had a superior fungicidal activity and a longer duration against Magnaporthe oryzae than pyraclostrobin suspension concentrate. In addition, the FeMOF-pectin nanocarriers showed no obvious phytotoxicity and could enhance the shoot length and root length of rice plants. More importantly, PYR@FeMOF-pectin nanoparticles had an 8-fold reduction in acute toxicity to zebrafish than that of pyraclostrobin suspension concentrate. Therefore, the dual-responsive FeMOF-pectin nanocarriers have great potential for realizing site-specific pesticide delivery and promoting plant growth.
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•A smart redox/pectinase dual-responsive pesticide delivery system was established.•PYR@FeMOF-pectin nanoparticles could protect pyraclostrobin from photodegradation.•PYR@FeMOF-pectin nanoparticles had a long duration against Magnaporthe oryzae.•The system would reduce the threats of pyraclostrobin to aquatic organisms.
In this letter, the problem of jamming data prediction in wireless communications is investigated. Both time and frequency domains are considered to construct the multi‐domain historical jamming data ...tensor. Besides, due to the perceiver's limited ability, false alarm data and missing detection data are considered. Two neural network prediction models are proposed to predict the jammers' future actions based on deep learning techniques. One is the multi‐variate long‐short‐term‐memory (multi‐variate LSTM) model, and the other is the 2‐D convolutional long‐short‐term‐memory model. Simulation results show that the proposed models have better prediction accuracy and robustness than the benchmark method.
Long-distance walking with heavy loads is often needed when going hiking or for field rescue, which is prone to cumulative fatigue. There is also a great need for labor-saving and biomechanical ...energy harvesting in daily life for extended security and communication needs. Here, we report a load-suspended backpack for harvesting the wasted energy of human motion based on a triboelectric nanogenerator (TENG). Two elastomers are incorporated into the backpack to decouple the synchronous movement of the load and the human body, which results in little or no extra accelerative force. With such a design, through theoretical analysis and field experiments, the backpack can realize a reduction of 28.75 % in the vertical oscillation of the load and 21.08 % in the vertical force on the wearer, respectively. Meanwhile, the mechanical-to-electric energy conversion efficiency is modeled and calculated to be 14.02 % under normal walking conditions. The designed backpack has the merits of labor-saving and shock absorption as well as electricity generation, which has the promising potential to be a power source for small-scale wearable and portable electronics, GPS systems, and other self-powered health care sensors.
Alternating current electroluminescent (ACEL) devices have the advantages of low power consumption, easy preparation, and good flexibility. However, a high‐voltage alternating current is usually ...demanded for driving devices, resulting in a strong dependence on an energy system with little wearing‐comfort and portability. Herein, a novel and feasible technology for lighting up ACEL via triboelectric nanogenerator (TENG) is proposed. The most significant innovation is the use of a capacitively driven circuit to significantly increase the output voltage of the generator, so as to get rid of the constraints of area, materials, environmental humidity, etc. Compared with direct connection of electroluminescent devices with TENG, the peak‐to‐peak voltage is 2.3 times that of the traditional method, and the transferred charges are increased to 3.4 times. This work realizes the self‐powered electroluminescent devices based on triboelectric nanogenerator with a compact composite structure, which not only is more effective but also has better flexibility and portability in the applications of soft robots, functional displays, smart skins, and wearable electronics. Besides, this capacitively driven circuit strategy is universal for those capacitive loads with demand for high voltage AC, which proposes a simple and practical approach to magnify the amplitudes of AC voltage and current from triboelectric nanogenerators.
A novel and feasible technology for lighting up ACEL via a triboelectric nanogenerator (TENG) is proposed. The most significant innovation is the use of a capacitively driven circuit to greatly increase the output voltage of generator. Compared with direct connection of electroluminescent devices with TENG, both the peak‐to‐peak voltage and the transferred charges are apparently improved.
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