Efficient removal of particulate matter (PM) is the major goal for various air cleaning technologies due to its huge impact on human health. Here, a washable high‐efficiency triboelectric air filter ...(TAF) that can be used multiple times is presented. The TAF consists of five layers of the polytetrafluoroethylene (PTFE) and nylon fabrics. Compared with traditional electrostatic precipitator, which requires a high‐voltage power supply, the TAF can be charged by simply rubbing the PTFE and nylon fabrics against each other. The electrical properties of the TAF are evaluated through the periodic contacting–separating of the PTFE and nylon fabrics using a linear motor, and an open‐circuit voltage of 190 V is achieved. After charging, the TAF has a removal efficiency of 84.7% for PM0.5, 96.0% for PM2.5, which are 3.22 and 1.39 times as large as the uncharged one. Most importantly, after washing several times, the removal efficiency of the TAF maintains almost the same, while the commercial face mask drops to 70% of its original efficiency. Furthermore, the removal efficiency of the PM2.5 is very stable under high relative humidity. Therefore, the TAF is promising for fabricating a reusable and high‐efficiency face mask.
A multilayer triboelectric air filter consists of five layers of polytetrafluoroethylene (PTFE) and nylon fabrics. A high removal efficiency is achieved by rubbing the fabrics against each other, and the removal efficiency maintains high under high humidity, in a durability test or after several washing cycles. Moreover, a face mask made of this air filter can be used in daily life.
We study a general product of two n-dimensional tensors A and B with orders m⩾2 and k⩾1. This product satisfies the associative law, and is a generalization of the usual matrix product. Using this ...product, many concepts and known results of tensors can be simply expressed and/or proved, and a number of applications of it will be given. Using the associative law of this tensor product and some properties on the resultant of a system of homogeneous equations on n variables, we define the similarity and congruence of tensors (which are also the generalizations of the corresponding relations for matrices), and prove that similar tensors have the same characteristic polynomials, thus the same spectra. We study two special kinds of similarity: permutational similarity and diagonal similarity, and their applications in the study of the spectra of hypergraphs and nonnegative irreducible tensors. We also define the direct product of tensors (in matrix case it is also called the Kronecker product), and give its applications in the study of the spectra of two kinds of the products of hypergraphs. We also give applications of this general product in the study of nonnegative tensors, including a characterization of primitive tensors, the upper bounds of primitive degrees and the cyclic indices of some nonnegative irreducible tensors.
Water wave energy is a promising clean energy source, which is abundant but hard to scavenge economically. Triboelectric nanogenerator (TENG) networks provide an effective approach toward massive ...harvesting of water wave energy in oceans. In this work, a coupling design in TENG networks for such purposes is reported. The charge output of the rationally linked units is over 10 times of that without linkage. TENG networks of three different connecting methods are fabricated and show better performance for the ones with flexible connections. The network is based on an optimized ball-shell structured TENG unit with high responsivity to small agitations. The dynamic behavior of single and multiple TENG units is also investigated comprehensively to fully understand their performance in water. The study shows that a rational design on the linkage among the units could be an effective strategy for TENG clusters to operate collaboratively for reaching a higher performance.
Objective
To assess the efficacy of intensive acupuncture (3 times weekly for 8 weeks) versus sham acupuncture for knee osteoarthritis (OA).
Methods
In this multicenter, randomized, sham‐controlled ...trial, patients with knee OA were randomly assigned to receive electroacupuncture (EA), manual acupuncture (MA), or sham acupuncture (SA) 3 times weekly for 8 weeks. Participants, outcome assessors, and statisticians were blinded with regard to treatment group assignment. The primary outcome measure was response rate, which is the proportion of participants who simultaneously achieved minimal clinically important improvement in pain and function by week 8. The primary analysis was conducted using a Z test for proportions in the modified intent‐to‐treat population, which included all randomized participants who had ≥1 post‐baseline measurement.
Results
Of the 480 participants recruited in the trial, 442 were evaluated for efficacy. The response rates at week 8 were 60.3% (91 of 151), 58.6% (85 of 145), and 47.3% (69 of 146) in the EA, MA, and SA groups, respectively. The between‐group differences were 13.0% (97.5% confidence interval 97.5% CI 0.2%, 25.9%; P = 0.0234) for EA versus SA and 11.3% (97.5% CI −1.6%, 24.4%; P = 0.0507) for MA versus SA. The response rates in the EA and MA groups were both significantly higher than those in the SA group at weeks 16 and 26.
Conclusion
Among patients with knee OA, intensive EA resulted in less pain and better function at week 8, compared with SA, and these effects persisted though week 26. Intensive MA had no benefit for knee OA at week 8, although it showed benefits during follow‐up.
Making use of water wave energy at large is one of the most attractive, low‐carbon, and renewable ways to generate electric power. The emergence of triboelectric nanogenerator (TENG) provides a new ...approach for effectively harvesting such low‐frequency, irregular, and “random” energy. In this work, a TENG array consisting of spherical TENG units based on spring‐assisted multilayered structure is devised to scavenge water wave energy. The introduction of spring structure enhances the output performance of the spherical TENG by transforming low‐frequency water wave motions into high‐frequency vibrations, while the multilayered structure increases the space utilization, leading to a higher output of a spherical unit. Owing to its unique structure, the output current of one spherical TENG unit could reach 120 µA, which is two orders of magnitude larger than that of previous rolling spherical TENG, and a maximum output power up to 7.96 mW is realized as triggered by the water waves. The TENG array fabricated by integrating four units is demonstrated to successfully drive dozens of light‐emitting diodes and power an electronic thermometer. This study provides a new type of TENG device with improved performance toward large‐scale blue energy harvesting from the water waves.
Combining the advantages of spring structures and multilayered structures, a triboelectric nanogenerator (TENG) array consisting of four spherical TENGs with spring‐assisted multilayered structure for harvesting water wave energy is fabricated. Driven by the water waves, this TENG array produces a high output power of 15.97 mW, demonstrating the capacity for efficient water wave energy harvesting.
In this paper, we introduce the class of cored hypergraphs and power hypergraphs, and investigate the properties of their Laplacian H-eigenvalues. From an ordinary graph, one may generate a k-uniform ...hypergraph, called the kth power hypergraph of that graph. Power hypergraphs are cored hypergraphs, but not vice versa. Sunflowers, loose paths and loose cycles are power hypergraphs, while squids, generalized loose s-paths and loose s-cycles for 2⩽s<k2 are cored hypergraphs, but not power graphs in general. We show that the largest Laplacian H-eigenvalue of an even-uniform cored hypergraph is equal to its largest signless Laplacian H-eigenvalue. Especially, we find out these largest H-eigenvalues for even-uniform squids. Moreover, we show that the largest Laplacian H-eigenvalue of an odd-uniform squid, loose path and loose cycle is equal to the maximum degree, i.e., 2. We also compute the Laplacian H-spectra of the class of sunflowers. When k is odd, the Laplacian H-spectra of the loose cycle of size 3 and the loose path of length 3 are characterized as well.
Heat stress is a major abiotic stress for plants, which can generate a range of biochemical and genetic responses. In ‘Ponkan’ mandarin fruit, hot air treatment (HAT) accelerates the degradation of ...citric acid. However, the transcriptional regulatory mechanisms of citrate degradation in response to HAT remain to be elucidated. Here, 17 heat shock transcription factor sequences were isolated, and dual‐luciferase assays were employed to investigate whether the encoded proteins that could trans‐activate the promoters of key genes in the GABA shunt, involved in citrate metabolism. We identified four heat shock transcription factors (CitHsfA7, CitHsfA3, CitHsfA4b and CitHsfA8) that showed trans‐activation effects on CitAco3, CitIDH3 and CitGAD4, respectively. Transient expression of the CitHsfs in citrus fruits indicated that CitHsfA7 was the only factor that resulted in a significant lowering of the citric acid content, and these results were confirmed by a virus‐induced gene silencing system (VIGS). Sub‐cellar localization showed that CitHsfA7 is located in the nucleus and is capable of binding directly to a putative HSE in the CitAco3 promoter and enhance its expression. We proposed that the induction of CitHsfA7 transcript level contributes to citric acid degradation in citrus fruit, via modulation of CitAco3 in response to HAT.
A heat shock transcription factor CitHsfA7 was characterized in citrus, which accelerates citric acid degradation via transcriptional regulating the aconitase gene (CitAco3) in response to heat stress. CitHsfA7 can be considered a key regulator mediating the role of heat treatment on citric acid degradation.
Dietary selenium (Se) intake within the physiological range is critical to maintain various biological functions, including antioxidant defence, redox homeostasis, growth, reproduction, immunity, and ...thyroid hormone production. Chemical forms of dietary Se are diverse, including organic Se (selenomethionine, selenocysteine, and selenium-methyl-selenocysteine) and inorganic Se (selenate and selenite). Previous studies have largely investigated and compared the health impacts of dietary Se on agricultural stock and humans, where dietary Se has shown various benefits, including enhanced growth performance, immune functions, and nutritional quality of meats, with reduced oxidative stress and inflammation, and finally enhanced thyroid health and fertility in humans. The emergence of nanoparticles presents a novel and innovative technology. Notably, Se in the form of nanoparticles (SeNPs) has lower toxicity, higher bioavailability, lower excretion in animals, and is linked to more powerful and superior biological activities (at a comparable Se dose) than traditional chemical forms of dietary Se. As a result, the development of tailored SeNPs for their use in intensive agriculture and as candidate for therapeutic drugs for human pathologies is now being actively explored. This review highlights the biological impacts of SeNPs on growth and reproductive performances, their role in modulating heat and oxidative stress and inflammation and the varying modes of synthesis of SeNPs.
Ag2O/g-C3N4 composites synthesized in this study were applied in the photocatalytic degradation of phenol under UV- and visible-light irradiation. X-ray diffraction, Fourier transform infrared ...spectroscopy, X-ray photoelectron spectroscopy, and transmission electron microscopy analysis demonstrated that Ag2O nanoparticles were well distributed on the surface of g-C3N4, and the heterostructure of Ag2O/g-C3N4 was formed. Compared with pure g-C3N4 and Ag2O, the Ag2O/g-C3N4 composite (8:1) displayed much higher photocatalytic activities in phenol degradation under UV- and visible-light irradiation. The degradation rate constant of 8:1 was 0.069 min–1 under visible light, which was almost 230 and 2.1 times more than that of pure g-C3N4 and Ag2O, respectively. Moreover, the formation of a certain amount of Ag0 on the surface of Ag2O under illumination contributed to the high stability of Ag2O/g-C3N4 photocatalysts. It was also found that photogenerated holes during the photocatalytic process played the predominant role in phenol degradation. The improved photochemical reactivities were attributed to the formation of the heterostructure between Ag2O and g-C3N4, the strong visible-light absorption, and the high separation efficiency of photoinduced electron–hole pairs resulting from the highly dispersed Ag2O particles.
Transcriptional regulatory mechanisms underlying lignin metabolism have been widely studied in model plants and woody trees, but seldom in fruits such as loquat, which undergo lignification. Here, ...twelve EjMYB genes, designed as EjMYB3-14, were isolated based on RNA-seq. Gene expression indicated that EjMYB8 and EjMYB9 were significantly induced in fruit with higher lignin content resulting from storage at low temperature (0°C), while two treatments (low temperature conditioning, LTC; heat treatment, HT) both alleviated fruit lignification and inhibited EjMYB8 and EjMYB9 expression. Dual-luciferase assays indicated that EjMYB8, but not EjMYB9, could trans-activate promoters of lignin-related genes EjPAL1, Ej4CL1 and Ej4CL5. Yeast one-hybrid assay indicated that EjMYB8 physically bind to Ej4CL1 promoter. Furthermore, the putative functions of EjMYB8 were verified using transient over-expression in both N. tabacum and loquat leaves, which increased lignin content. Moreover, combination of EjMYB8 and previously isolated EjMYB1 generated strong trans-activation effects on the Ej4CL1 promoter, indicating that EjMYB8 is a novel regulator of loquat fruit lignification.
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