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Coal dust diffusion during coal transportation and storage causes serious environmental pollution. The existing dust suppressant in previous studies was unable to achieve the expected effects owing to severe wind damage and rain erosion. Therefore, the current study synthesized and prepared an efficient and applicable dust suppressant for coal transportation and storage. Infrared spectroscopy and scanning electron microscope experiments were conducted during the synthesis to analyze the microstructure changes in the synthetic products. Moreover, viscosity was used as the evaluation index in the single-factor experiments to obtain the optimal synthesis conditions. Performance measurement results showed that the prepared dust suppressant had a strong protective effect on coal powder and could effectively resist the impact of wind damage and rain erosion. Compared with other dust suppressants, the proposed dust suppressant prepared showed more evident positive effects and longer lasting action time in the quantitative test. Moreover, the dried product could synergistically combust with coal powder, thereby possibly mitigating the tedious post-treatment process and increasing the utilization rate of resources.
Assuntos
Minas de Carvão , Carvão Mineral , Poeira , Monitoramento Ambiental , Poluição Ambiental , VentoRESUMO
Reactive oxygen species (ROS)/reactive nitrogen species (RNS) exert a "double edged" effect on the occurrence and development of ischemic stroke. We previously indicate that atmospheric pressure plasma (APP) shows a neuroprotective effect in vitro based on the ROS/RNS generations. However, the mechanism is still unknown. In this work, SH-SY5Y cells were treated with oxygen and glucose deprivation (OGD) injuries for stimulating the ischemic stroke pathological injury process. A helium APP was used for SH-SY5Y cell treatment for evaluating the neuroprotective impacts of APP preconditioning against OGD injuries with the optimized parameters. During the preconditioning, APP significantly raised the extracellular and intracellular ROS/RNS production. As a result, APP preconditioning increased SH-SY5Y cell autophagy by elevating LC3-II/LC3-I ratio and autophagosome formation. Meanwhile, APP preconditioning reduced cell apoptosis caused by OGD with the increased APP treatment time, which was abolished by pretreatment with autophagy inhibitor 3-methyladenine (3-MA). The ROS scavenger N-acetyl-L-cysteine (NAC) alone or combined with NO scavenger carboxy-PTIO abolished the APP preconditioning induced SH-SY5Y autophagy and the cytoprotection, whereas the NO scavenger alone did not. In addition, we observed the elevated phosphorylation of AMP-activated protein kinase (AMPK) and decreased phosphorylation of mammalian target of rapamycin (mTOR) in APP treated SH-SY5Y cells. This effect was attenuated by AMPK inhibitor Compound C (CC), the ROS scavenger NAC and autophagy inhibitor 3-MA. Furthermore, the cytoprotective effect of APP was preliminarily confirmed in the rats of middle cerebral artery occlusion (MCAO) model. Results showed that APP inhalation by rats during MCAO process could improve neurological functions, reduce cell apoptosis in brain tissues and decrease cerebral infarct volume. Our data suggested that ROS produced by APP preconditioning played a vital role in the neuroprotective effect of SH-SY5Y cells against OGD injuries by activating autophagy and ROS/AMPK/mTOR pathway.
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Previous studies suggest the potential efficacy of neuroprotective effects of gaseous atmospheric-pressure plasma (APP) treatment on neuronal cells. However, it remains unclear if the neuroprotective properties of the gas plasmas benefit the ischemic stroke treatment, and how to use the plasmas in the in vivo ischemic stroke models. Rats were subjected to 90 min middle cerebral artery occlusion (MCAO) to establish the ischemic stroke model and then intermittently inhaled the plasma for 2 min at 60 min MCAO. The regional cerebral blood flow (CBF) was monitored. Animal behavior scoring, magnetic resonance imaging (MRI), 2,3,5-triphenyltetrazolium chloride (TTC) staining, and hematoxylin and eosin (HE) staining were performed to evaluate the therapeutic efficacy of the gas plasma inhalation on MCAO rats. Intermittent gas plasma inhalation by rats with experimental ischemic stroke could improve neurological function, increase regional CBF, and decrease brain infarction. Further MRI tests showed that the gas plasma inhalation could limit the ischemic lesion progression, which was beneficial to improve the outcomes of the MCAO rats. Post-stroke treatment with intermittent gas plasma inhalation could reduce the ischemic lesion progression and decrease cerebral infarction volume, which might provide a new promising strategy for ischemic stroke treatment.
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The characteristics of striations in cylindrical hollow cathode discharge were investigated experimentally. The emission intensity and spectra of striations were measured, and the spatial characteristics of electron excitation temperature and relative electron density were calculated. It is shown that the emission intensity, the electron excitation temperature and the electron density appear as a periodic structure. The electrons have higher excitation temperature but lower density in the bright regions compared with the dark regions. The electron excitation temperature in the bright regions decreases from the cathode to the anode. It is also shown that the electron excitation temperature increases with increasing current.
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In the pipeline transportation process for crude oil, the most important and popular maintenance method for perforated and ruptured oil pipelines is the replacement of the damaged pipeline segment. However, this method has several disadvantages, including a complex process, large time consumption, and excessively high costs. The present study reported the preparation of a strong cross-linking hydrogel that served as a temporary blocking material during the long-distance oil pipeline partial replacement process. The prepared product was characterized by infrared spectroscopy, X-ray diffraction analysis, and scanning electron microscopy to analyze the microscopic reactions and structures. Orthogonal experiments for shear stress were performed to determine the optimal synthesis condition. The relevant experiments indicated that the proposed product can effectively isolate oil and oil gas, and a 4.5 m long hydrogel can resist the force of a 0.57 MPa overpressure. The blocked pipeline turned to a dredged state on changing the pipeline pressure. The flame resistance experiment showed that the hydrogel exhibited excellent flame resistance and could therefore ensure the safety of the hot work. On the basis of this hydrogel material, a new method for replacing the partially damaged oil pipeline was proposed.
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In this paper, we report the experimental results on the characteristics of plasma patterns with different planar electrode shapes in dielectric barrier glow discharge. The formation and the evolution of the discharge patterns at different voltages were investigated. The results show that the plasma patterns in this glow-barrier system form at the beginning of the discharge pulse. The limited size of planar electrodes and the electric field distribution are important factors for the pattern formation.
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Plasma is an ionized gas. It is typically formed at high temperature. As a result of both the development of low-temperature plasma sources and a better understanding of complex plasma phenomena over the last decade, "plasma medicine" has become a booming interdisciplinary research topic of growing importance that explores enormous opportunities at the interface of chemistry, plasma physics, and biomedical sciences with engineering. This review presents the latest development in plasma medicine in the area of the central nervous system and aims to introduce cutting-edge plasma medicine to clinical and translational medical researchers and practitioners.
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We confirm in this paper that Trichel pulse of negative corona is a common phenomenon that can occur in various gases rather than only in electronegative gases as considered in the last 70 years since G W Trichel firstly reported. Trichel pulse is exactly a mode transition between low-current Townsend and high-current normal glow regime, two pulseless stages of negative corona with different operating conditions and ion flux threshold. The rising of the pulse corresponds to the breakdown and formation of temporal glow discharge, the decay corresponds to the destroy of temporal sheath, and the interval (or repetition frequency of pulses) is determined by the re-building of the positive ion cloud to enhance significantly the local electric field for glow discharge to form again. The positive ions play a predominant role for the pulse formation and the mode transition, while the negative ions in electronegative gas are not necessary even if they affect greatly the pulsing process.
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The atmospheric pressure plasma jet (APPJ) has attracted the attention of many researchers from multiple disciplines in recent years because its emissions include multiple types of reactive nitrogen species (RNS) and reactive oxygen species (ROS). Our previous study has shown the cytoprotective effect of the APPJ against oxidative stress-induced injuries. The aim of the present study is to provide a detailed in vitro treatment protocol regarding the neuroprotective applications of helium APPJs on glucose deprivation-induced injury in SH-SY5Y cells. The SH-SY5Y human neuroblastoma-derived cell line was maintained in RPMI 1640 medium supplemented with 15% fetal calf serum. The culture medium was then changed to RPMI 1640 without glucose before APPJ treatment. After a 1 h incubation in a cell incubator, cell viability was determined using Cell Counting Kit 8. The results showed that, compared to the glucose deprivation group, cells treated with APPJ exhibited significantly increased cell viability in a dose-dependent manner, with 8 s/well observed as an optimal dose. Meanwhile, helium flow had no effect on the glucose deprivation-induced cell impairment. Our results indicated that APPJ could be potentially used as a treatment method for the diseases in the central nervous system related to glucose deprivation. This protocol could also be used as a cytoprotective application for other cells with different impairments, but the cell culture and APPJ treatment conditions should be readjusted, and the treatment dose must be relatively low.