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•Baicalein administered in the subacute phase ameliorated I/R induced brain injury.•Baicalein regulated M1/M2 transformation of microglia/macrophages in I/R injury.•Baicalein blocked ...the nuclear translocation of NF-κB/p65 in I/R injury.
Ischemic stroke is a cerebrovascular disease with high morbidity, high mortality, and high disability, representing a serious threat to human life and health. Clinically, the extensive injury caused by ischemic stroke results from ischemia-reperfusion (I/R) injury thrombolytic treatment. However, there are few reports on the use of medications in the subacute stage of cerebral I/R. Baicalein (5,6,7-trihydroxyflavone) is a biologically active ingredient extracted from the root of Scutellaria baicalensis Georgi. In the present study, we investigated the therapeutic effect of baicalein administered in the subacute phase of cerebral I/R injury in a rat model of ischemia induced by occlusion of the middle cerebral artery (MCA). Rats were treated daily with baicalein (200 mg/kg, i.g.) in the subacute phase (24 h after reperfusion) for 7 days. The results showed that baicalein significantly reduced neurobehavioral deficits and decreased brain infarct volume from 18.99% to 7.41%. Immunofluorescence analysis of the ischemic penumbra showed that baicalein significantly reduced expression of the M1 marker, cluster of differentiation (CD) 16 and CD86, and increased expression of the M2 marker, CD 163 and CD206, indicating that baicalein inhibited M1 transformation and promoted M2 transformation of microglia/macrophage to inhibit neuroinflammation. Moreover, baicalein suppressed NF-κB signaling by reducing IκBα phosphorylation and nuclear translocation of NF-κB/p65, which decreased the release of the pro-inflammatory factors IL-6, IL-18, and TNF-α. In addition, baicalein reduced phosphorylation of JNK, ERK and p38, which are involved modulation of microglia/macrophage M1/M2 polarization. Western blot analysis of apoptosis- and autophagy-related proteins showed that baicalein increased the Bcl-2/Bax ratio and reduced caspase-3 expression to decrease neuronal apoptosis and ameliorate neuronal loss. Baicalein also decreased the LC3-II/LC3-I ratio and promoted phosphorylation of the PI3K/Akt/mTOR signaling pathway which implied inhibition of autophagy. These observations suggest that baicalein exerts neuroprotective effects by reducing neuroinflammation, apoptosis and autophagy, and protects against cerebral I/R injury in the subacute phase in vivo.
Image reconstruction for electrical capacitance tomography (ECT) is a nonlinear problem. A generalized inverse operator is usually ill-posed (unbounded) and ill-conditioned (with a large norm). ...Therefore, the solutions for ECT are not unique and highly sensitive to the measurement noise. To improve the image quality, a new image reconstruction algorithm for ECT based on sparse representation is proposed. An unconventional basis, i.e., an extended sensitivity matrix consisting of some normalized capacitance vectors corresponding to the base permittivity elements is designed as an expansion frame. The permittivity distributions to be reconstructed can have a natural sparse representation based on the new basis and can be represented as a linear combination of the base elements. Another sparsity regularization method-the standard Landweber iteration with a threshold is also conducted for comparison. The proposed algorithm has been evaluated by both simulation (with and without noise) and experimental results for different permittivity distributions.
The North China Plain (NCP) has been suffering from groundwater storage (GWS) depletion and land subsidence for a long period. This paper collects data on GWS changes and land subsidence from in situ ...groundwater-level measurements, literature, and satellite observations to provide an overview of the evolution of the aquifer system during 1971–2015 with a focus on the sub-regional variations. It is found that the GWS showed a prolonged declining rate of −17.8 ± 0.1 mm/yr during 1971–2015, with a negative correlation to groundwater abstraction before year ~2000 and a positive correlation after ~2000. Statistical correlations between subsidence rate and the GWS anomaly (GWSA), groundwater abstraction, and annual precipitation show that the land subsidence in three sub-regions (Beijing, Tianjin, and Hebei) represents different temporal variations due to varying driver factors. Continuous drought caused intensive GWS depletion (−76.1 ± 6.5 mm/yr) and land subsidence in Beijing during 1999–2012. Negative correlations between total groundwater abstraction and land subsidence exhibited after the 1980s indicate that it may be questionable to infer subsidence from regional abstraction data. Instead, the GWSA generally provides a reliable correlation with subsidence. This study highlights the spatio-temporal variabilities of GWS depletion and land subsidence in the NCP under natural and anthropogenic impacts, and the importance of GWS changes for understanding land subsidence development.
The preparation of bio-composites based on engineering plastic is always restricted by the low thermal stability of lignocellulose. In this study, the thermal stability of lignocellulose was improved ...by boric acid modification. Then, the borated lignocellulose was characterized to analyze the mechanism of involved in the improvement of thermal stability. Furthermore, the untreated and borated lignocellulose was combined with polyamide 6 to produce bio-composites. The effects of lignocellulose content and boric acid modification on the color, thermal stability and mechanical properties of the resulting composites were compared and analyzed. Boric acid protected lignocellulose from thermal degradation, increasing the lightness of the resulting composites. However, boric acid appeared to have a negative effect on the mechanical strength of the resulting composites. In summary, this study demonstrated that bio-composites based on engineering plastic could be prepared by improving the thermal stability of lignocellulose using a boric acid treatment.
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•Bio-composites based on engineering plastic were prepared by improving the thermal stability of lignocellulose.•The thermal stability of lignocellulosic fiber was improved by boric acid modification.•The chemical structure of lignocellulose changed because of the complexation reaction between boric acid and lignocellulose.•Boric acid has a positive effect on the physical properties of the composites.
The utilization of four types of biomass particles, including hardwood (poplar), softwood (radiata pine), crop (wheat straw) and bamboo (moso bamboo), as reinforcing fillers in preparing high density ...polyethylene (HDPE) based composites was studied. To improve interfacial compatibility, maleic anhydride grafted polyethylene (MAPE) was applied as the coupling agent. The effects of the biomass species on the mechanical and water absorption properties of the resulting composites were evaluated based on chemical composition analysis. A creep-recovery test was conducted in single cantilever mode using a dynamic mechanical analyzer. Results show that the four types of biomass particles had similar chemical compositions but different composition contents. Poplar particles with high cellulose content loading in the HDPE matrix exhibited higher tensile and flexure properties and creep resistance. Fracture morphology analysis indicated a weak particle-matrix interface in wheat straw based composites. Given the high crystallinity and minimum hemicellulose content, the moso bamboo reinforced composite showed high impact strength and better water resistance.
Eighty-one samples from both shallow and deep aquifers were collected and analyzed to reveal groundwater hydrogeochemical characteristics and estimate groundwater quality suitability for irrigation ...and drinking purposes based on groundwater quality indexes models including the sodium adsorption ratio (SAR), residual sodium carbonate (RSC), solute sodium percentage (%Na), magnesium hazard (MH), permeability index (PI) and health risk model. The results from groundwater quality suitability assessment indicated that shallow groundwater in the most part of the study region was suitable for irrigation regardless of EC, RSC and MH, while groundwater from the deep aquifer was suitable for irrigation purpose in nearly all parts of the study region. 24.49% and 14.29% of the deep groundwater sampling locations presented high fluoride (F
−
) concentrations exceeded the Grade III value (1 mg/L) from Quality Standard for Groundwater of China and the maximum permissible value of 1.5 mg/L recommended by the WHO for drinking use, respectively. Non-carcinogens hazard quotient (HQ) values of NO
3
−
–N, NH
4
+
–N, NO
2
−
–N, Fe, and Mn with the exception of F
−
were all within the acceptable safety limit (HQ < 1). Efficient strategies and scientific decisions were suggested for groundwater resource protection and water quality improvements should be adopted for sustainable groundwater exploitation.
Lignin nanoparticles (LNP) were obtained by an acidolysis process from corn pristine lignin. X-ray photoelectron spectroscopy (XPS) and radical scavenging activity (RSA) of the free radical ...2,2-diphenyl-1-picrylhydrazyl (DPPH) confirmed a significant enhancement in reactivity of LNP in comparison with pristine lignin. Polyurethane (PU) nanocomposites were prepared by pre-polymerization of polyethylene glycol and diisocyanates in the presence of different contents (1, 3, 5 and 7 wt%) of LNP. The effects of LNP, serving as both biobased polyol and crosslinker, on the mechanical, hydrophobicity and dielectric behavior of the resulted PU nanocomposites were investigated. Tensile test results showed an overall enhancement for mechanical performance, and the elongation at break exceeded 1000% for all studied PU nanocomposites. Meanwhile, dynamic mechanical analysis (DMA) revealed that the crosslinking densities gradually increased with LNP addition. Furthermore, LNP based PU nanocomposites showed inherent resistance towards ultraviolet radiation and frequency dependent behavior for electrical conductivity. On the other hand, LNP based PU nanocomposites revealed good thermal reprocessability due to the transcarbamoylation reaction in the presence of DBTDL catalyst.
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•Lignin nanoparticles were obtained by a facile acidolysis process from corn lignin.•LNP served as both biobased polyol and crosslinker in polyurethane nanocomposites.•The thermal decomposition temperature of the PU nanocomposites was enhanced.•PU-LNP nanocomposites have inherent resistance towards ultraviolet radiation.•PU-LNP nanocomposites show a frequency dependent behavior for electrical conductivity.
Images reconstructed by an existing image reconstruction algorithm for electrical capacitance tomography (ECT) are usually blurred or corrupted due to data noise. To recover the missing or corrupted ...pixels in the images, an approach to robustly reconstruct images based on low-rank decomposition is presented for ECT. With this approach, recovering the permittivity distribution is recast as one of recovering low-rank matrix from corrupted images. A convex optimization technique is used to obtain the correct low-rank matrix and the error matrix. Experimental results show the effectiveness of the proposed method. Furthermore, the simplified optimization method is fast and could be used for online imaging. The method can also be used in other tomographic techniques.
South-to-North Water Diversion Project Central Route (SNWDP-CR) is one of the largest human engineering projects aimed at redistributing water resources, receiving a worldwide attention. It conveys ...water from southern China to the Beijing Plain northward through a 1300-km long canal system and operated since December 2014. Before this date, water supply to Beijing was mainly provided by means of aquifer over-exploitation, causing a significant lowering of the piezometric levels and a huge land subsidence. After 3 years of SNWDP-CR activity, it results of general interest to investigate if the implemented managed aquifer recharge and the supposedly reduced aquifer exploitation have been already accompanied by a piezometric recovery and a decrease of the subsidence rates. This is evaluated for the first time in this contribution, by integrating and statistically analyzing a large dataset consisting of hydrogeologic information, piezometric records, and land subsidence measurements carried out by Persistent Scatterer Interferometry and levelling. The results show that a small (~3 m) to large (~10 m) raise of the piezometric levels has been recorded in the central portion of the north Beijing plain with a certain decrease (up to 10 mm/yr) of the subsidence rates. Conversely, piezometric drawdown and land subsidence has continued to increase in the remaining parts of the study area. Managed aquifer recharge (MAR) carried out through infiltration ponds has produced a positive feedback, but at a local scale only. Therefore, it will be necessary to wait a longer period to assess whether the SNWDP-CR will be able to mitigate the hydrogeological hazards connected to groundwater overuse or only to counterbalance in part the growing water demand of the Chinese capital.
•Effects of SNWDP operation on groundwater level (GL) and land subsidence (LS) in Beijing•An integrated application of InSAR, GIS and statistics to spatiotemporal datasets•GL was spatially variable, with a significant recovery around an artificial recharge site•LS mitigation was detected in a large area southwest of the artificial recharge zone•Delayed compaction of fine sediments was likely responsible for the ongoing LS
In this article, we introduce a framework for two-qutrit Werner states tomography with Gaussian noise. The measurement scheme is based on the symmetric, informationally complete positive ...operator-valued measure. To make the framework realistic, we impose the Gaussian noise on the measured states numbers. Through numerical simulation, we successfully reconstructed the two-qutrit Werner states in various experimental scenarios and analyzed the optimal scenario from four aspects: fidelity, purity, entanglement, and coherence.
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