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Cerebral ischemia and reperfusion is a common pathophysiologic process, which is involved in stroke and brain trauma. Recent studies revealed that activating epidermal growth factor receptor (EGFR) ameliorates cerebral ischemia/reperfusion (I/R) injury, however, the precise mechanisms remain to be illuminated. In this study, the neurological behavior was evaluated by Longa score. The infarct volume was performed by 2, 3, 5-triphenyltetrazolium chloride (TTC) staining and the expression of p-EGFR, p-STAT3, connexin (Cx43), Bax and Bcl-2 were detected by Western blot. The neurological behavior and infarct volume were increased in rats with cerebral I/R injury. Epidermal growth factor (EGF) pretreatment significantly decreased neurological deficit and infarct volume. However, the antagonist of EGFR, AG1478 attenuated the EGF-induced reduction of neurological deficit and infarct volume. Moreover, the inhibitor of JAK2/STAT3, AG490 undermined the protective effects stimulated by activating EGFR in rats with I/R injury. In addition, EGF pretreatment increased the expression of Bcl-2 and reduced the expression of Bax and Cx43, and the effects were abolished after using AG1478 and AG490. These findings implicate that JAK2/STAT3 pathway plays the vital role in I/R injury protection from activating EGFR. And the neuroprotective effects may associate with inhibiting the Cx43 expression and the inhibition of apoptosis.

Superabsorbents, used in the removal of oils and organic solvents, play a extremely important role in environmental protection. There is an urgent demand for environment-friendly and high-performance absorbent materials with high selectivity for oils and organic solvents, and is also challenging. Herein, a facile and fluorine-free method to fabricate Polyacrylonitrile @ Polydimethylsiloxane (PAN@PDMS) coaxial nanofibrous aerogels (NFAs) was developed. The steps for synthesis included: coaxial electrospinning - freeze drying - in situ polymerization. The obtained PAN@PDMS NFAs displayed excellent absorption capacities for various oils and organic solvents (55.43–127.37 times of its weight), and efficient water-in-oil emulsions separation with high separation flux (1718 ± 45 L·m−2·h−1) and excellent separation efficiency (above 99.47 wt%). Particularly, the NFAs showed outstanding mechanical resilience (above 83% recovery after repeating 200 cycles at 80% strain) and could be reused by simply squeezing the oil/organic solvent out of it. More importantly, the PAN@PDMS NFAs showed good resistance against various chemicals such as acids and alkalis. Therefore, this study offers a facile methodology for the fabrication of NFAs that are expected to be promising candidate materials for practical oily wastewater treatment in environmental protection.

Super-hydrophobic F-TiO2@PP membranes were developed from polypropylene (PP) non-woven fabric by in situ cross-linking polymerization of trifluorofluorooctyl methacrylate (FOMA) and sol–gel-derived titanium dioxide with vinyltriethoxysilane (VTES). Due to the formation of super-hydrophobic “coral”-like synapses on the filamentous surfaces of PP non-woven fabric, F-TiO2@PP membranes showed extremely high water contact angles up to 157° and capability of rapidly absorbing oil drops. The F-TiO2@PP membranes were also able to expel water from water-in-oil emulsions with robustly high oil permeate fluxes (up to 11,000 L m−2h−1 under gravity), water removing efficiency (up to 99.7%), re-usability and long-term stability even at the presence of surfactant and salts. Such superior performance could lead to potential applications in rapid collection and efficient purification of recovered oily organic components from waste liquids or accidental oil discharges in marine or continental situations.

To engineer bone tissue, it is crucial to design scaffolds with micro- and nano-sized architecture imitating approximate hierarchical structure of native bone, and afford desirable biological properties by introducing biocompatible polymers and bioceramics into the scaffolds. Here, a novel scaffold consisting of poly-3-hydroxybutyrate-co-3-hydroxyvalerate (PHBV)/polyaspartic acid (PAA) was fabricated by electrospinning and nano-hydroxyapatite (nHA) was deposited by calcium-phosphate dipping process for bone tissue regeneration. Characterization of the prepared nanofibers revealed the formation of definite nHA crystal, porous structure of membranes, improved wettability with nHA deposition and satisfied mechanical properties. Human fetal osteoblasts were cultured on nanofibers and experienced in vitro evaluations of cell proliferation, adhesion and mineralization confirming the non-cytotoxicity and biocompatibility of scaffolds. Cells proliferation rate and ALP expression on PHBV/PAA-nHA were 36.40% and 40.14% higher than on PHBV/PAA, respectively. The utmost significance of this study is introducing bioactive PAA-nHA on polymeric nanofibers to regulate and improve specific cells adhesion, proliferation and mineralization of osteoblasts. All results indicate PHBV/PAA-nHA nanofibrous scaffolds can be applied as biomimetic platform for bone tissue repairation with appropriate physico-chemical properties, osteoinductivity and osteoconductivity.

With a small number of elements in uniform circular arrays (UCAs), the performance of beamspace transformation (BT) based methods for 2D direction-of-arrival (DOA) estimation in the presence of mutual coupling suffers serious degradation. The performance breakdown is associated with the residual term which is introduced by the BT. To solve this problem, a novel algorithm which modifies the beamspace data is proposed in this paper. Based on the estimated azimuth angles obtained by a UCA-RARE-like method and the estimated elevation angles obtained by a new searching method, the beamspace data is iteratively revised by removing its residual component. Thus, unbiased 2D DOA estimates can be obtained depending on the revised beamspace data. Simulation results are given to verify the effectiveness of the proposed algorithm and a comparison is made with results from existed methods.

To obtain a large aperture for improving parameter estimation performance, this paper introduces a novel polarization sensitive array composed of augmented and optimally nested subarrays with differently oriented antennas, and then proposes an algorithm for direction of arrival (DOA) and Stokes parameter estimation of completely and partially polarized signals, in unknown nonuniform noise environment and without source number knowledge. The aperture of the proposed array significantly increases since the difference co-array of the optimally nested subarray can obtain the maximum degrees of freedom. There is a systematic procedure to determine the numbers of antennas in the two subarrays in order to obtain similar apertures for the two subarrays. Unfortunately, both the difference co-arrays of the optimally nested subarray and between the two subarrays have holes, which degrades performance of parameter estimation. By using oblique projection operators, the proposed algorithm first fills the holes and suppresses the nonuniform noise to obtain hole-free and noiseless difference co-arrays, and then the difference co-arrays are employed to form a block-sparsity model. Finally, based on the model, block orthogonal matching pursuit algorithm is used for parameter estimation. The Cramer-Rao bound and its existence condition are derived. Simulation results are given to demonstrate the superior performance of the proposed array and method.

Sparse circular arrays (SCAs) have many advantages, e.g., providing 360 ° azimuthal coverage and reducing mutual coupling. This paper presents a novel coprime sparse circular array (CSCA) for significantly improving underdetermined direction of arrival (DOA) estimation performance compared to the existing SCAs, e.g., nested sparse circular array (NSCA) and super nested sparse circular array (S-NSCA). The CSCA is obtained by connecting two sparse subarrays concircularly with two displacements, and the sensor positions are determined by a systematic procedure. The array geometry has closed-form expressions and the inter-sensor spacings of the two sparse subarrays are coprime. The CSCA contains all the good properties of the SCAs. Simultaneously, the CSCA has less angular dependence due to its nearly uniform sensor distribution and has much smaller mutual coupling effect by enlarging its minimum inter-sensor spacing, when compared to the NSCA and S-NSCA. Due to its merits, it can be applied to sonar, communication, and navigation, to name a few. Then an l 1 -based method is used for underdetermined DOA estimation. Theoretical analysis and simulation results show the superiority of the CSCA.

An improved free surface electrospinning for high throughput of nanofibers by utilizing micro-bubble solution system has been successfully developed in the present paper. Compared with the conventional solution system based free surface electrospinning, more jets were observed to form on the edges of the stepped pyramid shaped spinneret simultaneously and nanofibers similar in quality (diameter, diameter distribution) were produced. In addition, the effect of bubble size on the diameters of nanofibers is experimentally studied, revealing that the smaller bubble size favors the smaller diameter. This novel solution system based free surface electrospinning will benefit to the development of free surface electrospinning.

A novel coaxial electrospinning process modified from free surface electrospinning has been successfully developed to massive production of core–shell nanofibers in the present paper. A two-layer polymer system, with the lower layer consisting a core polymer solution and the upper layer consisting a sheath polymer solution, is subjected to a sufficient electrical field. As a result, multiple coaxial jets spontaneously form on the edges of the stepped pyramid-shaped spinneret. Compared with the conventional concentric spinneret based coaxial electrospinning, the possibility of clogging was avoided and an enhancement of more than 100 times over the traditionally obtained core–shell nanofibers productivity was obtained. This novel design has potential for high throughput of electrospun core–shell nanofibers.

Choices of bicycle and trip chain are important decisions in an individual's daily travel activities. Little is known about the causal relationship between the two decisions. It is interesting to ask if a decision on bicycle choice is made prior to the determination on a trip chain, or is dependent on the pre-determined chain pattern. This study aims to explore the relationship between the choices of bicycle and trip chain and capture the order of decision between them. Based on the survey data from a medium-sized Chinese city, the co-evolutionary approach with logit-modeling framework was estimated for the study purpose. Results show that there are more bicycle uses in the subsistence trip chains as compared to these non-subsistence ones. Considering the interaction between the two decisions improves the predicting accuracy of both bicycle choice and chain choice. In most cases, a trip chain is determined prior to a decision on bicycle choice, especially when the chain contains subsistence activities. For travelers who currently using a bicycle, most of them first decide the chain type and then choose a bicycle accordingly. Most of travelers who first determine the trip mode do not consider using a bicycle. We also estimate a model to predict the decision process of travelers. The order of decision is mainly impacted by the individual and household characteristics as well as the travel attributes. Findings of this study are discussed to assist the development of policies to promote cycling in urban areas.

Zeolite NaA crystals were prepared by hydrothermal synthesis under room-temperature conditions. The products were characterized by XRD, SEM, IR and particle size analysis. Some influence parameters such as crystallization time, aging time, stirring speed, different sources of silicon and aluminum on the crystalline end products were studied. The results showed that crystallization time was a crucial factor for the final products, well-shaped crystals could be obtained at the crystallization time of 72 h. While further prolonging the crystallization time more, crystals continued to grow, along with the changes of crystal size distributions. The crystals obtained with the aging time of 1, 1.5, 2 and 3 h show the mean particle sizes of 368, 356, 338 and 314 nm, with the crystal size distribution ranges of 82–435, 70–441, 54–450 and 40–476 nm, respectively. Longer aging time leads to the mean particle size of crystal decrease. Whilst, the stirring speed affects the particle size distribution only slightly. Moreover, the aluminum source has much more obviously influence on the crystal phase of final product than the silicon source does in this system.

Macrophage-derived foam cells in atherosclerotic lesions are generally thought to play a major role in the pathology of the disease. Hypoxia-inducible factor-1alpha (HIF-1alpha) was recently found to play an important role in atherosclerosis. Here we applied RNA interference to study the role of HIF-1alpha in foam cell formation in vitro. Transfection of HIF-1alpha-siRNA reduced HIF-1alpha synthesis as measured on mRNA and protein level by real-time RT-PCR, Western blot. It was found that RNA interference for HIF-1alpha with small interfering RNAs (HIF-1alpha-siRNA) inhibits foam cell formation by the human monoblastic cell line (U937) which was treated with oxidized low-density lipoprotein (ox-LDL) while the majority of atherosclerosis-related genes, such as cyclooxygenase-2 (COX-2), vascular cell adhesion molecule-1 (VCAM-1), interleukin-1beta (IL-1beta), and so on, were down-regulated, through large scale gene expression analysis using DNA microarrays. These data demonstrate that induction of HIF-1alpha by atherogenic factors may be a key step in coordinating the cellular events that result in atherosclerotic lesions.

A novel approach to needleless electrospinning of nanofibers has been developed to increase the productivity of nanofibers. Multiple jets were observed to form on the edges of the stepped pyramid-shaped spinneret simultaneously. Compared with the traditional needle based electrospinning, nanofibers produced by the stepped pyramid-shaped spinneret were finer and an enhancement of more than 100 times over the traditionally obtained nanofibers productivity was obtained. The finite element analysis of electric field revealed a strong electric field gradient around the edges of the spinneret. The effect of applied voltage on nanofiber diameter and productivity were also explored. This novel design instrument avoids the possibility of clogging and will benefit to the development of needleless electrospinning.