The separation of oil and water is a worldwide challenge due to the ever-increasing amount of oily industrial wastewater and polluted oceanic waters, as well as the increasing frequency of oil spill ...accidents. As the leader of advanced fibrous materials, electrospun nanofibers combine the properties of tunable wettability, large surface area, high porosity, good connectivity, fine flexibility, and ease of scalable synthesis from various materials (polymer, ceramic, carbon, etc.), and they hold great potential for many emerging environmental applications, including the separation of oily wastewater. In this review, the recent progress in the design and fabrication of electrospun nanofibrous materials with tunable surface wettability for oil/water separation applications is summarized and highlighted. This review covers the research and development starting from the design concepts and the synthesis of nanofibrous sorbents, nanofibrous membranes, and nanofibrous aerogels for effective oil/water separation. The review concludes with a brief forecast of challenges and future directions in this rapidly expanding field.
Abstract
Desiccants play vital roles in dehumidification and atmospheric water harvesting; however, current desiccants have mediocre hygroscopicity, limited recyclability, and high energy ...consumption. Herein, we report a wood-inspired moisture pump based on electrospun nanofibrous membrane for solar-driven continuous indoor dehumidification. The developed moisture pump with multilayer wood-like cellular networks and interconnected open channels is composed of a desiccant layer and a photothermal layer. The desiccant layer exhibits an unprecedented moisture absorption capacity of 3.01 g g
−1
at 90% relative humidity (RH), fast moisture absorption and transport rates, enabling atmospheric water harvesting. The photothermal layer shows a high solar absorption of 93%, efficient solar thermal conversion, and good moisture permeability, thus promoting water evaporation. The moisture pump efficiently reduces the indoor relative humidity to a comfort level (40‒60% RH) under one-sun illumination. This work opens the way to develop new-generation, high-performance nanofibrous membrane-based desiccants for energy-efficient humidity control and atmospheric water harvesting.
Biomimetic nanofibrous scaffolds mimicking important features of the native extracellular matrix provide a promising strategy to restore functions or achieve favorable responses for tissue ...regeneration. This review provides a brief overview of current state-of-the-art research designing and using biomimetic electrospun nanofibers as scaffolds for tissue engineering. It begins with a brief introduction of electrospinning and nanofibers, with a focus on issues related to the biomimetic design aspects. The review next focuses on several typical biomimetic nanofibrous structures (e.g. aligned, aligned to random, spiral, tubular, and sheath membrane) that have great potential for tissue engineering scaffolds, and describes their fabrication, advantages, and applications in tissue engineering. The review concludes with perspectives on challenges and future directions for design, fabrication, and utilization of scaffolds based on electrospun nanofibers.
Since 2006, a rapid development has been achieved in a subject area, so called electro-spinning/netting (ESN), which comprises the conventional electrospinning process and a unique electro-netting ...process. Electro-netting overcomes the bottleneck problem of electrospinning technique and provides a versatile method for generating spider-web-like nano-nets with ultrafine fiber diameter less than 20 nm. Nano-nets, supported by the conventional electrospun nanofibers in the nano-fiber/nets (NFN) membranes, exhibit numerious attractive characteristics such as extremely small diameter, high porosity, and Steiner tree network geometry, which make NFN membranes optimal candidates for many significant applications. The progress made during the last few years in the field of ESN is highlighted in this review, with particular emphasis on results obtained in the author's research units. After a brief description of the development of the electrospinning and ESN techniques, several fundamental properties of NFN nanomaterials are addressed. Subsequently, the used polymers and the state-of-the-art strategies for the controllable fabrication of NFN membranes are highlighted in terms of the ESN process. Additionally, we highlight some potential applications associated with the remarkable features of NFN nanostructure. Our discussion is concluded with some personal perspectives on the future development in which this wonderful technique could be pursued.
Waterproof and breathable membranes (WBMs) with simultaneous environmental friendliness and high performance are highly desirable in a broad range of applications; however, creating such materials ...still remains a tough challenge. Herein, we present a facile and scalable strategy to fabricate fluorine-free, efficient, and biodegradable WBMs via step-by-step dip-coating and heat curing technology. The hyperbranched polymer (ECO) coating containing long hydrocarbon chains provided an electrospun cellulose acetate (CA) fibrous matrix with high hydrophobicity; meanwhile, the blocked isocyanate cross-linker (BIC) coating ensured the strong attachment of hydrocarbon segments on CA surfaces. The resulting membranes (TCA) exhibited integrated properties with waterproofness of 102.9 kPa, breathability of 12.3 kg m–2 d–1, and tensile strength of 16.0 MPa, which are much superior to that of previously reported fluorine-free fibrous materials. Furthermore, TCA membranes can sustain hydrophobicity after exposure to various harsh environments. More importantly, the present strategy proved to be universally applicable and effective to several other hydrophilic fibrous substrates. This work not only highlights the material design and preparation but also provides environmentally friendly and high-performance WBMs with great potential application prospects for a variety of fields.
This paper studies the real-time monitoring of rainfall and atmosphere characteristics and college students’ physical training based on target tracking algorithm. In this paper, we use the target ...tracking algorithm, combined with the GNSS observation stations of BJFS, LHAZ, URUM, CUSV, and PIMO, to calculate the change of rainfall atmosphere characteristics of ULUM station, and then get the PWV above the ULUM station, and compare the PWV obtained by the radiosonde station with the ground-based GNSS inversion results to verify the change of rainfall atmosphere characteristics based on the target tracking algorithm. In order to solve the problem of inaccurate tracking and positioning when the background is cluttered, a target tracking algorithm based on channel reliable local rank transform is proposed. The local rank transform feature combined with lab three-channel image is used to form 16-dimensional feature channel, from which the effective feature channel is selected for fusion to enhance the expression ability of the algorithm for target features. The experimental results show that, compared with the feature channel selected by reliability coefficient, the local rank transform feature channel selected by experience has better tracking effect in specific scene and more accurate position estimation of target. At the same time, with the transformation of China from a sports power to a sports power, sports training is scientific, science and technology help sports, and the guarantee system of sports science integration is gradually improved. The state attaches great importance to the role of science and technology in the training of college athletes, and has purchased a set of Firstbeat sports monitoring system to monitor the athletes’ heart rate in real time. A scientific research group is set up to provide scientific and technological services, record the heart rate of athletes during training and competition, so as to determine the “load characteristics” of athletes, and explore the monitoring of athletes’ training with heart rate as the object, so as to improve the training quality of athletes.
Oxygen isotope records from Chinese caves characterize changes in both the Asian monsoon and global climate. Here, using our new speleothem data, we extend the Chinese record to cover the full ...uranium/thorium dating range, that is, the past 640,000 years. The record's length and temporal precision allow us to test the idea that insolation changes caused by the Earth's precession drove the terminations of each of the last seven ice ages as well as the millennia-long intervals of reduced monsoon rainfall associated with each of the terminations. On the basis of our record's timing, the terminations are separated by four or five precession cycles, supporting the idea that the '100,000-year' ice age cycle is an average of discrete numbers of precession cycles. Furthermore, the suborbital component of monsoon rainfall variability exhibits power in both the precession and obliquity bands, and is nearly in anti-phase with summer boreal insolation. These observations indicate that insolation, in part, sets the pace of the occurrence of millennial-scale events, including those associated with terminations and 'unfinished terminations'.
Macrophages play a key role in obesity-induced inflammation. Omega-3 polyunsaturated fatty acids (ω-3 PUFAs) eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) exert anti-inflammatory ...functions in both humans and animal models, but the exact cellular signals mediating the beneficial effects are not completely understood. We previously found that two nutrient sensors AMP-activated protein kinase (AMPK) and SIRT1 interact to regulate macrophage inflammation. Here we aim to determine whether ω-3 PUFAs antagonize macrophage inflammation via activation of AMPK/SIRT1 pathway. Treatment of ω-3 PUFAs suppresses lipopolysaccharide (LPS)-induced cytokine expression in macrophages. Luciferase reporter assays, electrophoretic mobility shift assays (EMSA) and Chromatin immunoprecipitation (ChIP) assays show that treatment of macrophages with ω-3 PUFAs significantly inhibits LPS-induced NF-κB signaling. Interestingly, DHA also increases expression, phosphorylation and activity of the major isoform α1AMPK, which further leads to SIRT1 over-expression. More importantly, DHA mimics the effect of SIRT1 on deacetylation of the NF-κB subunit p65, and the ability of DHA to deacetylate p65 and inhibit its signaling and downstream cytokine expression require SIRT1. In conclusion, ω-3 PUFAs negatively regulate macrophage inflammation by deacetylating NF-κB, which acts through activation of AMPK/SIRT1 pathway. Our study defines AMPK/SIRT1 as a novel cellular mediator for the anti-inflammatory effects of ω-3 PUFAs.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Crop pests seriously affect the yield and quality of crop. To timely and accurately control crop pests is particularly crucial for crop security, quality of life and a stable agricultural economy. ...Crop pest detection in field is an essential step to control the pests. The existing convolutional neural network (CNN) based pest detection methods are not satisfactory for small pest recognition and detection in field because the pests are various with different colors, shapes and poses. A three-scale CNN with attention (TSCNNA) model is constructed for crop pest detection by adding the channel attention and spatial mechanisms are introduced into CNN. TSCNNA can improve the interest of CNN for pest detection with different sizes under complicated background, and enlarge the receptive field of CNN, so as to improve the accuracy of pest detection. Experiments are carried out on the image set of common crop pests, and the precision is 93.16%, which is 5.1% and 3.7% higher than ICNN and VGG16, respectively. The results show that the proposed method can achieve both high speed and high accuracy of crop pest detection. This proposed method has certain practical significance of real-time crop pest control in the field.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
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