Solutions of Fractional Konopelchenko-Dubrovsky and Nizhnik-Novikov-Veselov Equations Using a Generalized Fractional Subequation Method

A new generalized fractional subequation method based on the relationship of fractional coupled equations is proposed. This method is applied to the space-time fractional coupled Konopelchenko-Dubrovsky equations and Nizhnik-Novikov-Veselov equations. As a result, many exact solutions are obtained including hyperbolic function solutions, trigonometric function solutions, and rational solutions. It is observed that the proposed approach provides a simple and reliable tool for solving many other fractional coupled differential equations

Weighted endpoint estimates for commutators of multilinear fractional integral operators

summary:Let $m$ be a positive integer, $0<\alpha <mn$, $\vec {b}=(b_{1},\cdots ,b_{m})\in {\rm BMO}^m$. We give sufficient conditions on weights for the commutators of multilinear fractional integral operators \Cal {I}^{\vec {b}}_{\alpha } to satisfy a weighted endpoint inequality which extends the result in D. Cruz-Uribe, A. Fiorenza: Weighted endpoint estimates for commutators of fractional integrals, Czech. Math. J. 57 (2007), 153–160. We also give a weighted strong type inequality which improves the result in X. Chen, Q. Xue: Weighted estimates for a class of multilinear fractional type operators, J. Math. Anal. Appl., 362, (2010), 355–373

MHD turbulence formation in solar flares: 3D simulation and synthetic observations

Turbulent plasma motion is common in the universe, and invoked in solar flares to drive effective acceleration leading to high energy electrons. Unresolved mass motions are frequently detected in flares from extreme ultraviolet (EUV) observations, which are often regarded as turbulence. However, how this plasma turbulence forms during the flare is still largely a mystery. Here we successfully reproduce observed turbulence in our 3D magnetohydrodynamic simulation where the magnetic reconnection process is included. The turbulence forms as a result of an intricate non-linear interaction between the reconnection outflows and the magnetic arcades below the reconnection site, in which the shear-flow driven Kelvin-Helmholtz Instability (KHI) plays a key role for generating turbulent vortices. The turbulence is produced above high density flare loops, and then propagates to chromospheric footpoints along the magnetic field as Alfvenic perturbations. High turbulent velocities above 200 km s^-1 can be found around the termination shock, while the low atmosphere reaches turbulent velocities of 10 km s^-1 at a layer where the number density is about 10^11 cm^-3. The turbulent region with maximum non-thermal velocity coincides with the region where the observed high-energy electrons are concentrated, demonstrating the potential role of turbulence in acceleration. Synthetic views in EUV and fitted Hinode-EIS spectra show excellent agreement with observational results. An energy analysis demonstrates that more than 10% of the reconnection downflow kinetic energy can be converted to turbulent energy via KHI

An efficient background modeling approach based on vehicle detection

The existing Gaussian Mixture Model(GMM) which is widely used in vehicle detection suffers inefficiency in detecting foreground image during the model phase, because it needs quite a long time to blend the shadows in the background. In order to overcome this problem, an improved method is proposed in this paper. First of all, each frame is divided into several areas(A, B, C and D), Where area A, B, C and D are decided by the frequency and the scale of the vehicle access. For each area, different new learning rate including weight, mean and variance is applied to accelerate the elimination of shadows. At the same time, the measure of adaptive change for Gaussian distribution is taken to decrease the total number of distributions and save memory space effectively. With this method, different threshold value and different number of Gaussian distribution are adopted for different areas. The results show that the speed of learning and the accuracy of the model using our proposed algorithm surpass the traditional GMM. Probably to the 50th frame, interference with the vehicle has been eliminated basically, and the model number only 35% to 43% of the standard, the processing speed for every frame approximately has a 20% increase than the standard. The proposed algorithm has good performance in terms of elimination of shadow and processing speed for vehicle detection, it can promote the development of intelligent transportation, which is very meaningful to the other Background modeling methods. (2015) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only

Self-absorption in the solar transition region

Transient brightenings in the transition region of the Sun have been studied for decades and are usually related to magnetic reconnection. Recently, absorption features due to chromospheric lines have been identified in transition region emission lines raising the question of the thermal stratification during such reconnection events. We analyse data from the Interface Region Imaging Spectrograph (IRIS) in an emerging active region. Here the spectral profiles show clear self-absorption features in the transition region lines of Si\,{\sc{iv}}. While some indications existed that opacity effects might play some role in strong transition region lines, self-absorption has not been observed before. We show why previous instruments could not observe such self-absorption features, and discuss some implications of this observation for the corresponding structure of reconnection events in the atmosphere. Based on this we speculate that a range of phenomena, such as explosive events, blinkers or Ellerman bombs, are just different aspects of the same reconnection event occurring at different heights in the atmosphere.Comment: Accepted for publication in Ap

In Situ Absorption in Rat Intestinal Tract of Solid Dispersion of Annonaceous Acetogenins

Isolated from Annona squamosa L, Annonaceous acetogenins (ACGs) exhibit a broad range of biological properties yet absorbed badly due to the low solubility. Solid dispersion in polyethylene glycol 4000 (PEG 4000) has been developed to increase the solubility and oral absorption of ACGs. The formulation of ACGS-solid dispersion was optimized by a simplex lattice experiment design and carried out by a solvent-fusion method. We studied the absorption property of ACGs in rat's intestine, which showed there was a good absorption and uptake percentages with solid dispersion. The study on uptake percentage in different regions of rat's intestine attested that the duodenum had the best permeability, followed by jejunum, ileum, and colon in order with no significant differences. So the paper drew the conclusion that solid dispersion could improve the solubility and oral absorption of annonaceous acetogenins

Anti-Pseudomonas aeruginosa activity of natural antimicrobial peptides when used alone or in combination with antibiotics

The World Health Organization has recently published a list of 12 drug-resistant bacteria that posed a significant threat to human health, and Pseudomonas aeruginosa (P. aeruginosa) was among them. In China, P. aeruginosa is a common pathogen in hospital acquired pneumonia, accounting for 16.9–22.0%. It is a ubiquitous opportunistic pathogen that can infect individuals with weakened immune systems, leading to hospital-acquired acute and systemic infections. The excessive use of antibiotics has led to the development of various mechanisms in P. aeruginosa to resist conventional drugs. Thus, there is an emergence of multidrug-resistant strains, posing a major challenge to conventional antibiotics and therapeutic approaches. Antimicrobial peptides are an integral component of host defense and have been found in many living organisms. Most antimicrobial peptides are characterized by negligible host toxicity and low resistance rates, making them become promising for use as antimicrobial products. This review particularly focuses on summarizing the inhibitory activity of natural antimicrobial peptides against P. aeruginosa planktonic cells and biofilms, as well as the drug interactions when these peptides used in combination with conventional antibiotics. Moreover, the underlying mechanism of these antimicrobial peptides against P. aeruginosa strains was mainly related to destroy the membrane structure through interacting with LPS or increasing ROS levels, or targeting cellular components, leaded to cell lysis. Hopefully, this analysis will provide valuable experimental data on developing novel compounds to combat P. aeruginosa

Overexpression of lncRNA-MEG3 inhibits endometrial cell proliferation and invasion via miR-21–5p/DNMT3B/Twist

Recent studies have found that lncRNA-MEG3(MEG3) plays an important role in the development of EMs (Endometriosis), but the specific mechanism needs to be further explored. This study aimed to investigate the effect of MEG3 on the proliferation, invasion of EMs cells. The authors used RT-qPCR to detect the expression of MEG3 and miR-21–5p in EMs tissues and hESCs cells, MTT and Transwell to detect cell proliferation and invasion, western blotting assay to detect the expression of DNMT3B and Twist, MSP to detect the methylation of Twist. The present study's detection results showed that MEG3 was lowly expressed in EMs tissues and hESCs cells, and overexpression of MEG3 could down-regulate miR-21–5p and inhibit endometrial cell proliferation and invasion. In addition, overexpression of MEG3 upregulated the expression of DNMT3B and promoted the methylation of TWIST. In conclusion, the present findings suggest that MEG3 is downregulated in EMs tissues, and overexpression of MEG3 can promote the activity of DNA methyltransferase DNMT3B by downregulating miR-21–5p, thereby promoting the methylation of Twist, downregulating Twist level to inhibits hESCs cells proliferation and invasion