In recent years, the problem of environmental pollution has become more and more serious, and environmental pollution has become a topic of concern. PM2.5, PM10, hazy weather, and other words about ...environmental pollution have become hot words and topics for the media and the public to talk about, and environmental pollution control is called for by the media and the public. This reflects the rapid development of economy and the obvious changes in people’s living standards, and people have higher requirements and aspirations for their lives and the environment they live in, and their awareness of environmental protection is getting stronger and stronger; however, it also reflects that the rapid development of the economy comes at the cost of damaging the environment. This paper analyzes the current situation and governance dilemma of rural environment by means of field research from dynamic portfolio evaluation theory, explains the problems and causes of environmental pollution management under the requirement of polycentric governance, and proposes countermeasures to solve the problem of environmental pollution management in county. The paper aims to analyze the current state of environmental pollution in rural areas through literature review, villagers’ field interviews, and field research and to explain the application of polycentric governance to rural environmental pollution management in county in the region.
Reactive oxygen species (ROS) play vital roles in intestinal inflammation. Therefore, eliminating ROS in the inflammatory site by antioxidant enzymes such as catalase and superoxide dismutase may ...effectively curb inflammatory bowel disease (IBD). Here, Escherichia coli Nissle 1917 (ECN), a kind of oral probiotic, was genetically engineered to overexpress catalase and superoxide dismutase (ECN-pE) for the treatment of intestinal inflammation. To improve the bioavailability of ECN-pE in the gastrointestinal tract, chitosan and sodium alginate, effective biofilms, were used to coat ECN-pE via a layer-by-layer electrostatic self-assembly strategy. In a mouse IBD model induced by different chemical drugs, chitosan/sodium alginate coating ECN-pE (ECN-pE(C/A)
) effectively relieved inflammation and repaired epithelial barriers in the colon. Unexpectedly, such engineered EcN-pE(C/A)
could also regulate the intestinal microbial communities and improve the abundance of Lachnospiraceae_NK4A136 and Odoribacter in the intestinal flora, which are important microbes to maintain intestinal homeostasis. Thus, this study lays a foundation for the development of living therapeutic proteins using probiotics to treat intestinal-related diseases.
A simple hetero-core optical fiber (MMF-NCF-MMF) surface plasmon resonance (SPR) sensing structure was proposed. The SPR spectral sensitivity, full width of half peak (FWHM), valley depth (VD), and ...figure of merit (FOM) were defined to evaluate the sensing performance comprehensively. The effect of gold film thickness on the refractive index and temperature sensing performance was studied experimentally. The optimum gold film thickness was found. The maximum sensitivities for refractive index and temperature measurement were obtained to be 2933.25 nm/RIU and −0.91973 nm/°C, respectively. The experimental results are helpful to design the SPR structure with improved sensing performance. The proposed SPR sensing structure has the advantages of simple structure, easy implementation, and good robustness, which implies a broad application prospect.
A kind of compact all-fiber-optic vector magnetic sensor is proposed and demonstrated. The sensor consists of a side-polished-fiber (SPF)-integrated with singlemode-no core-singlemode (SNS) fiber ...structure. A section of side-polished fiber breaks the axially symmetry of the composite structure. The as-fabricated sensor supports vector sensing and has a magnetic field strength sensitivity of up to -2370 pm/mT over 2-6 mT range. The physical mechanism is that the modal interference is strongly influenced by the refractive index (RI) near the side-polished surface. The advantages of the proposed sensor lie in low cost, simple structure and easy manufacture, which make it attractive in the field of magnetic field vector sensing.
Allelopathy has been demonstrated to be an environmentally friendly way to control harmful algal blooms. Allelochemicals of submerged plants have attracted extensive research due to their ...bioavailability. The dose-response of submerged plant extracts on algae growth is worth further study to improve the efficiency of bioremediation. In this study, the ultrasonic-enzymatic assistance method was utilized to extract allelochemicals from Ceratophyllum, Myriophyllum spicatum, and Vallisneria. The effects of low-dosage and high-dosage extracts on the growth of Microcystis aeruginosa were compared based on cell biomass and morphology, photosynthetic parameters, reactive oxygen species (ROS), superoxide dismutase (SOD), catalase (CAT), and malondialdehyde (MDA) levels. The results showed that the three submerged plant extracts exhibited hormetic effects at low dosages and inhibitory effects at high dosages on algal growth. Within 48 h of cultivation, the enzymatic activities of Microcystis aeruginosa fluctuated, suggesting that the extracts of the three submerged plants induced different oxidative reactions. After 120 h of cultivation with high-dosage extracts, the physiological and biochemical reactions of Microcystis aeruginosa significantly decreased, indicating the effectiveness of the allelopathy of Ceratophyllum, Myriophyllum spicatum, and Vallisneria extracts in controlling algal blooms. The phenomenon of hormesis and inhibition effect confirmed a significant dose-response relationship between the allelochemicals of submerged plant extracts and Microcystis aeruginosa, which could be attributed to the composition and content of allelochemicals. These findings highlight the importance of the relative concentration of the biological algaecide and will benefit other researchers in determining the safe dosage of plant allelochemicals when used in water.
Buruli ulcer (BU) is an emerging infectious disease that causes disfiguring skin ulcers. The causative agent, Mycobacterium ulcerans, secretes toxin called mycolactone that triggers inflammation and ...immunopathology. Existing treatments are lengthy and consist of drugs developed for tuberculosis. Here, we report that a pyrazolo1,5-apyridine-3-carboxamide, TB47, is highly bactericidal against M. ulcerans both in vitro and in vivo. In the validated mouse model of BU, TB47 alone reduces M. ulcerans burden in mouse footpads by more than 2.5 log
CFU compared to the standard BU treatment regimen recommended by the WHO. We show that mutations of ubiquinol-cytochrome C reductase cytochrome subunit B confer resistance to TB47 and the dissimilarity of CydABs from different mycobacteria may account for their differences in susceptibility to TB47. TB47 is highly potent against M. ulcerans and possesses desirable pharmacological attributes and low toxicity that warrant further assessment of this agent for treatment of BU.
Vanadium‐based derivatives, featuring affordable cost and high theoretical capacity, have gathered widespread interest in the context of aqueous zinc‐ion batteries (ZIBs). However, the further ...application of vanadium‐based materials is hindered by the limited electrical conductivity and cycling lifespan. Herein, 1D chain‐like structure vanadyl ethylene glycolate (VEG, (VO(CH2O)2)), growing on the Ti3C2Tx MXene nanosheets, is synthesized via a one‐step oil‐bath heating process as cathode materials for ZIBs. Benefiting from the hybrid structure with high conductivity and abundant reactive sites, the VEG@MXene cathode exhibits a remarkable specific capacity (360.3 mAh g−1 at 0.5 A g−1), and impressive capacity retention (up to 85.2% after 3000 cycles at 10 A g−1). Mechanism analysis reveals a gradual phase transition from the original VEG on MXene to the stable Zn3V2O7(OH)2·2H2O nanoflakes accompanied by continuous zinc ion intercalation/deintercalation, offering more pathways for zinc ion transport. This work suggests that engineering conductivity‐enhanced vanadium‐based materials is a rational approach for developing promising cathode materials of ZIBs.
A structure optimized composite, vanadyl ethylene glycolate@Ti3C2Tx MXene (VEG@MXene) via a one‐step oil‐bath heating approach is proposed as the cathode material for aqueous zinc‐ion batteries. With the MXene substrate enhancing the electrical conductivity and providing abundant reactive sites, the zinc//VEG@MXene batteries can deliver remarkable electrochemical performances.
Phase-to-height mapping is one of the important processes in three dimensional phase measurement profilometry. But, in traditional phase-to-height mapping method, the measurement accuracy is affected ...by device attitude, so it needs saving a large amount of mapping equations to achieve high-quality phase-to-height mapping. In order to improve that, this paper proposes an improved phase-to-height mapping method combine with device attitude. Firstly, we get the unwrapped phase of the target. Then, using generalized regression neural network is used to reduce the offset of phase information at the same height due to the randomness of device attitude. Last, the phase-to-height mapping is completed by substituting the unwrapped phase (the difference between having detected object and no detected object) of eliminate the offset into improved phase-to-height mapping method. Experimental results show that the proposed method could achieve high-quality phase-to-height mapping with less mapping equation and less memory space. Compared with the nonlinear phase-to-height mapping method (probabilistic neural network to eliminate phase offset), its accuracy is improved by 44.30%. Compared with the nonlinear phase-to-height mapping method (radial basis function neural network to eliminate phase offset), the accuracy is improved by 39.58%.
Underwater captured images often suffer from poor visibility caused by two major degradations: scattering and absorption. In this paper, we propose a hybrid framework for underwater image ...enhancement, which unifies underwater white balance and variational contrast and saturation enhancement. In our framework, the improved underwater white balance (UWB) algorithm is integrated with histogram stretching, aiming to better compensate the attenuation difference along the propagation path and remove undesired color castings. In addition, a variational contrast and saturation enhancement (VCSE) model is developed based on the enhanced result obtained from UWB. The advantages of VCSE model lie in the improvements of contrast and saturation as well as the elimination of hazy appearance induced by scattering. Moreover, we design a fast Gaussian pyramid-based algorithm to speed up the solving of VCSE model. The improvements achieved by our method include the more effective in color correction, haze removal and detail clarification. Extensive qualitative and quantitative assessments demonstrate that the proposed approach obtains high quality outcomes, which outperforms several state-of-the-art methods. Application tests further verify the effectiveness and broad application prospects of our proposed method.
Wireless signal fingerprint positioning technology has been widely used in indoor positioning. In view of the influence of a large number of interference noise in indoor, the error of receive signal ...strength indicator is large, the more complex and chaotic indoor environment, the location accuracy deviation of the system will be very large; an algorithm based on Kalman filter is proposed to filter the velocity and direction of motion of indoor robots. The position coordinates of the robot are estimated by RSSI-based positioning method, and the indoor robot positioning model and Kalman filter model are established. Kalman filter autoregressive algorithm is used to optimize the estimated position coordinates of the robot. Mathematical reasoning and simulation results show that the probability of positioning error is 80% when Kalman filter is not used, and the location error is controlled within 1.2 m after Kalman filter, which effectively improves the location accuracy of indoor robots.
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