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Previous studies have estimated ground-level concentrations of particulate matter 2.5 (PM2.5) using satellite-derived aerosol optical depth (AOD) in conjunction with meteorological and land use variables. However, the impacts of urbanization on air pollution for predicting PM2.5 are seldom considered. Nighttime light (NTL) data, acquired with the Visible Infrared Imaging Radiometer Suite (VIIRS) aboard the Suomi National Polar-orbiting Partnership (S-NPP) satellite, could be useful for predictions because they have been shown to be good indicators of the urbanization and human activity that can affect PM2.5 concentrations. This study investigated the potential of incorporating VIIRS NTL data in statistical models for PM2.5 concentration predictions. We developed a mixed-effects model to derive daily estimations of surface PM2.5 levels in the Beijing-Tianjin-Hebei region using 3 km resolution satellite AOD and VIIRS NTL data. The results showed the addition of NTL information could improve the performance of the PM2.5 prediction model. The NTL data revealed additional details for predication results in areas with low PM2.5 concentrations and greater apparent seasonal variation due to the seasonal variability of human activity. Comparison showed prediction accuracy was improved more substantially for the model using NTL directly than for the model using the vegetation-adjusted NTL urban index that included NTL. Our findings indicate that VIIRS NTL data have potential for predicting PM2.5 and that they could constitute a useful supplemental data source for estimating ground-level PM2.5 distributions. [ABSTRACT FROM AUTHOR]

In this work, the different orientation of SiNWs on Si pyramids by a two step MACE method have been fabricated. By tuning the structure of Ag catalyst film and controlling the concentration of H2O2 or the etching temperature, the tunability of the orientation of SiNWs from <111> to <100> on Si pyramids was realized. Si structures composed of Si pyramids and SiNWs exhibit better omnidirectional light-trapping ability by multiple reflections. Si structures with structural tunability and enhanced light harvesting performance will find a wide variety of significant applications in solar cells, photodetectors, and optoelectronic devices. [ABSTRACT FROM AUTHOR]

The long non-coding RNA (lncRNA) plasmacytoma variant translocation 1 (PVT1) has been identified as an oncogene in numerous diseases, and aberrant lncRNA PVT1 expression has been associated with the development of cancer. However, the underlying mechanism by which lncRNA PVT1 affects cell invasion in esophageal cancer has been not demonstrated. In the current study, the expression of lncRNA PVT1 was found to be increased in esophageal cancer specimens (n=77) by reverse transcription-quantitative polymerase chain reaction, and was correlated with tumor stage (P=0.009) and metastasis (P<0.001). In vitro, by using transwell assay, upregulation of lncRNA PVT1 promoted the invasion of TE-1 esophageal cancer cells; while downregulation of lncRNA PVT1 inhibited Eca-109 cell invasion. In addition, western blot analysis indicated that upregulation of lncRNA PVT1 may induce epithelial-to-mesenchymal transition (EMT) by regulating the expression levels of EMT markers (E-cadherin, N-cadherin and vimentin). In conclusion, lncRNA PVT1 is able to regulate the invasion of esophageal cancer cells by inducing EMT. [ABSTRACT FROM AUTHOR]

There exist scaling correlations between the edge weights and the nodes' degrees in weighted social networks. Based on the empirical findings, we study a multi-state voter model on weighted social networks where the weight is given by the product of agents' degrees raised to a power θ and there exist persistent individuals whose opinions are independent of those of their friends. We find that the fraction of each opinion will converge to a value which only relates to the degrees of initial committed agents and the scaling exponent θ. The analytical predictions are verified by numerical simulations. The model indicates that agents' degrees and scaling exponent can significantly influence the final coexistence or consensus state of opinions. We also study the influence of degree mixing characteristics on the dynamics model by numerical simulations and discuss the relation between the model and the other related opinion dynamics models on social networks with different topological structures and initial configurations. [ABSTRACT FROM AUTHOR]

Pyrolysis of 1 g of waste chicken feathers (quills and barbs) in supercritical carbon dioxide (sc-CO2) system at 600 °C for 3 h leads to the formation of 0.25 g well-shaped carbon microspheres with diameters of 1-5 μm and 0.26 g ammonium bicarbonate ((NH4)HCO3). The products were characterized by powder X-ray diffraction (XRD), Field emission scanning electron microscopy (FE-SEM), Raman spectroscopic, FT-IR spectrum, X-ray electron spectroscopy (XPS), and N2 adsorption/desorption measurements. The obtained carbon microspheres displayed great superhydrophobicity as fabric coatings materials, with the water contact angle of up to 165.2 ± 2.5°. The strategy is simple, efficient, does not require any toxic chemicals or catalysts, and generates two valuable materials at the same time. Moreover, other nitrogen-containing materials (such as nylon and amino acids) can also be converted to carbon microspheres and (NH4)HCO3 in the sc-CO2 system. This provides a simple strategy to extract the nitrogen content from natural and man-made waste materials and generate (NH4)HCO3 as fertilizer. [ABSTRACT FROM AUTHOR]

Background/Aims: P-glycoprotein (P-gp, i.e., MDR1) is associated with the phenotype of multidrug resistance (MDR) and causes chemotherapy failure in the management of cancers. Searching for effective MDR modulators and combining them with anticancer drugs is a promising strategy against MDR. Asiatic acid (AA), a natural triterpene isolated from the plant Centella asiatica, may have an antitumor activity. The present study assessed the reversing effect of AA on MDR and possible molecular mechanisms of AA action in MDR1- overexpressing cisplatin (DDP)-resistant lung cancer cells, A549/DDP. Methods: Human lung adenocarcinoma A549/DDP cells were either exposed to different concentrations of AA or treated with DDP, and their viability was measured by the MTT assay. A Rhodamine 123 efflux assay, immunofluorescent staining, ATPase assay, reverse-transcription PCR (RT-PCR), and western blot analysis were conducted to elucidate the mechanisms of action of AA on MDR. Results: Our results showed that AA significantly enhanced the cytotoxicity of DDP toward A549/DDP cells but not its parental A549 cells. Furthermore, AA strongly inhibited P-gp expression by blocking MDR1 gene transcription and increased the intracellular accumulation of the P-gp substrate Rhodamine 123 in A549/DDP cells. Nuclear factor (NF)-kB (p65) activity, IkB degradation, and NF-kB/p65 nuclear translocation were markedly inhibited by pretreatment with AA. Additionally, AA inhibited the MAPK-ERK pathway, as indicated by decreased phosphorylation of ERK1 and -2, AKT, p38, and JNK, thus resulting in reduced activity of the Y-box binding protein 1 (YB1) via blockage of its nuclear translocation. Conclusions: AA reversed P-gp-mediated MDR by inhibition of P-gp expression. This effect was likely related to downregulation of YB1, and this effect was mediated by the NF-kB and MAPK-ERK pathways. AA may be useful as an MDR reversal agent for combination therapy in clinical trials. [ABSTRACT FROM AUTHOR]

Wearable sensors-based human activity recognition introduces many useful applications and services in health care, rehabilitation training, elderly monitoring and many other areas of human interaction. Existing works in this field mainly focus on recognizing activities by using traditional features extracted from Fourier transform (FT) or wavelet transform (WT). However, these signal processing approaches are suitable for a linear signal but not for a nonlinear signal. In this paper, we investigate the characteristics of the Hilbert-Huang transform (HHT) for dealing with activity data with properties such as nonlinearity and non-stationarity. A multi-features extraction method based on HHT is then proposed to improve the effect of activity recognition. The extracted multi-features include instantaneous amplitude (IA) and instantaneous frequency (IF) by means of empirical mode decomposition (EMD), as well as instantaneous energy density (IE) and marginal spectrum (MS) derived from Hilbert spectral analysis. Experimental studies are performed to verify the proposed approach by using the PAMAP2 dataset from the University of California, Irvine for wearable sensors-based activity recognition. Moreover, the effect of combining multi-features vs. a single-feature are investigated and discussed in the scenario of a dependent subject. The experimental results show that multi-features combination can further improve the performance measures. Finally, we test the effect of multi-features combination in the scenario of an independent subject. Our experimental results show that we achieve four performance indexes: recall, precision, F-measure, and accuracy to 0.9337, 0.9417, 0.9353, and 0.9377 respectively, which are all better than the achievements of related works. [ABSTRACT FROM AUTHOR]

Since sparse representation (SR) was first introduced into robust face recognition, the argument has lasted for several years about whether sparsity can improve robust face recognition or not. Some work argued that the robust sparse representation (RSR) model has a similar recognition rate as non-sparse solution, while it needs a much higher computational cost due to the larger feature dimensionality in the pixel space. In this study, the authors reveal that the standard RSR model, which expands the dictionary with the identity matrix to reconstruct corruption or occlusion in face images, is essentially a non-sparse solution with a relatively large residual. The reason why the RSR model underperforms may be its inappropriately expanded bases rather than the sparsity itself. Thereby, this study proposes to design a dictionary with an expanded noise bases set which can precisely reconstructs any corruption or occlusion in face images in a subspace. Experimental results show that the algorithm can greatly improve recognition rates for robust face recognition. In addition, the algorithm can be simply performed in a subspace with a small feature dimensionality, thus efficient enough for real systems. This study makes us come to the conclusion that solving the approximation problem in raw pixel space is not necessary for robust face recognition, while solving in a subspace with a much smaller feature dimensionality is enough when the dictionary is well expanded. Finally, this study also confirms that the sparsity plays an important role in SR based classification. [ABSTRACT FROM AUTHOR]

Radioactive aerosols harmful to humans are often produced in nuclear accidents, and their source term characteristics (total volume and particle size distribution) and dispersion patterns have important implications for accident response and hazard assessment. However, experimental studies of radioactive aerosols cannot be directly conducted in open space due to the hazardous nature of radioactive aerosols. In this study, silver was used instead of plutonium to study the aerosol source term under different specific internal energy inputs (SIEI) to simulate a low order explosion in an accident. Results show that aerosol release fraction (ARF) and respirable release fraction (RRF) of silver increase linearly with SIEI first, then varies in a range of 8% ~ 19%, with a turning point at SIEI of 1.4 MJ/kg. Analysis suggests an increase of difference between ARF and RRF with respect to SIEI. The size distribution of silver aerosol around 10 µm is influenced by SIEI significantly, which could be possibly attributed to the interactions between silver aerosol and ambient aerosol (solid HE products or rust). Comparison between the source term of silver and plutonium suggests that silver is a good surrogate of plutonium in studying aerosol for SIEI of MJ/kg level. [ABSTRACT FROM AUTHOR]

Northern Hemisphere (NH) snow cover extent (SCE) has diminished in spring and early summer since the 1960s. Historical simulations from phase 5 of the Coupled Model Intercomparison Project (CMIP5) estimated about half as much NH SCE reduction as observed, and thus underestimated the associated climate responses. This study investigates atmospheric responses to realistic decreasing snow anomalies using multiple ensemble transient integrations of climate models forced by observed light and heavyNHsnow cover years, specifically satellite-based observations ofNHSCE and snow water equivalent from March to August in 1990 (light snow) and 1985 (heavy snow), as a proxy for the trend. The primary atmospheric responses to March-August NH snow reduction are decreased soil moisture, increased surface air temperature, general tropospheric warming in the extratropics and the Arctic, increased geopotential heights, and weakening of the midlatitude jet stream and eddy kinetic energy. The localized response is maintained by persistent increased diabatic heating due to reduced snow anomalies and resulting soilmoisture drying, and the remote atmospheric response results partly from horizontal propagation of stationary Rossby wave energy and also from a transient eddy feedback mechanism. In summer, atmospheric responses are significant in both the Arctic and the tropics and are mostly induced by contemporaneous snow forcing, but also by the summer soil moisture dry anomaly associated with early snow melting. [ABSTRACT FROM AUTHOR]

Stretchable micropower sources with high energy density and stability under repeated tensile deformation are key components of flexible/wearable microelectronics. Herein, through the combination of strain engineering and modulation of the interlayer spacing, freestanding and lightweight MXene/bacterial cellulose (BC) composite papers with excellent mechanical stability and a high electrochemical performance are first designed and prepared via a facile all-solution-based paper-making process. Following a simple laser-cutting kirigami patterning process, bendable, twistable, and stretchable all-solid-state micro-supercapacitor arrays (MSCAs) are further fabricated. As expected, benefiting from the high-performance MXene/BC composite electrodes and rational sectional structural design, the resulting kirigami MSCAs exhibit a high areal capacitance of 111.5 mF cm−2, and are stable upon stretching of up to 100% elongation, and in bent or twisted states. The demonstrated combination of an all-solution-based MXene/BC composite paper-making method and an easily manipulated laser-cutting kirigami patterning technique enables the fabrication of MXene-based deformableall-solid-state planar MSCAs in a simple and efficient manner while achieving excellent areal performance metrics and high stretchability, making them promising micropower sources that are compatible with flexible/wearable microelectronics. [ABSTRACT FROM AUTHOR]

Downregulated microRNA (miR)-124 is common in numerous types of cancer, including non-small cell lung cancer (NSCLC). A previous study by the authors demonstrated that LIM-homeobox domain 2 (LHX2) was upregulated and promoted cell growth in NSCLC. However, whether LHX2 affects the migratory and invasive abilities of NSCLC cells and the association of LHX2 with miR-124 remains unclear. The present study revealed that miR-124 expression was frequently decreased in human NSCLC cells and tissues and negatively correlated with LHX2 expression, which was increased in NSCLC cells and tissues. Furthermore, the transfection of miR-124 mimic significantly inhibited endogenous expression of LHX2 mRNA and protein in A549 and H1299 cells, and miR-124 inhibitor promoted LHX2 expression. Of note, overexpression of miR-124 in A549 and H1299 cells attenuated cellular migratory and invasive abilities, and this was observed in LHX2-silenced A549 and H1299 cells. Knockdown of miR-124 augmented the migratory and invasive abilities in A549 and H1299 cells. The 3'-untranslated region of LHX2 transcript has also been identified to be a putative target of miR-124. Taken together, the results revealed that miR-124 may inhibit migration and invasion by repressing LHX2 expression in NSCLC cells. The findings of the present study suggested that overexpression of miR-124 or silencing of LHX2 may provide a therapeutic strategy for advanced NSCLC. [ABSTRACT FROM AUTHOR]

The configuration of electrode materials is of great significance to the performance of supercapacitors (SCs) because of its direct effects on specific surface area and electron transfer path. Given this, herein, a series of Co3O4 hierarchical configurations composed of porous acicular nanorods are designedly synthesized on Ni foam with in-site self-organization method depending on the addition of NH4F. In the absence of NH4F, Co3O4 nanorods self-assemble into porous urchin-like structure (PULS), while the introduction of NH4F can induce the vertical growth of Co3O4 acicular nanorods, forming porous acicular nanorod arrays (PANRAs). By simply tuning the concentration of NH4F, the Co3O4 PANRAs with different specific surface area can be obtained. As expected, Co3O4 PANRAs electrode for SCs (using 1 mmol of NH4F) exhibits high specific capacitance (1486 F g−1 at 1 A g−1) and excellent cycling stability (98.8% retention after 5000 continuous charge–discharge cycles), which are better than those of Co3O4 PULS electrode (658.2 F g−1 at 1 A g−1, 90.4%). Corresponding solid-state symmetric SC achieves a high energy density of 48.63 Wh kg−1 at power density of 600 W kg−1. Such superior performance is attributed to fast charge transfer kinetics, facile electron transport and ions diffusion rate resulting from porous array structure, indicating the importance of configuration design of electrode materials for high performance SCs. [ABSTRACT FROM AUTHOR]