Sulfated Cyclocarya paliurus polysaccharides exert immunomodulatory potential on macrophages via Toll-like receptor 4 mediated MAPK/NF-κB signaling pathways

The biological activity of plant polysaccharides can be enhanced by sulfated modification.In this study,the immunomodulatory effect of sulfated Cyclocarya paliurus polysaccharides(SCP3)on macrophages RAW264.7 and its potential molecular mechanism were investigated.Results showed that SCP3 at 25-100μg/m L increased viability and improved phagocytosis of RAW264.7 cells.Meanwhile,SCP3 could activate mitogen-activated protein kinase(MAPK)and nuclear factor kappa B(NF-κB)signaling pathways,which increased the phosphorylation of Erk1/2,JNK,p38 and NF-κB p65,promoting secretion of cytokines tumor necrosis factorα(TNF-α),interleukin 6(IL-6)and nitric oxide(NO)as well as the production of reactive oxygen species(ROS).In addition,Toll-like receptor 4(TLR4)receptor inhibitors were able to block the production of NO and TNF-αby SCP3-stimulated macrophages.Based on Western blot analysis and validation using specific inhibitors against MAPK and NF-κB signaling pathways,the results demonstrated that SCP3 induced macrophages activation and enhanced TNF-αand NO production via TLR4-mediated MAPK and NF-κB pathways.In summary,SCP3 has significant immunomodulatory potential.The underlying molecular mechanism was that SCP3 activates macrophages via TLR4 receptors to promote ROS production,which in turn activates the downstream MAPK/NF-κB signaling pathway and then increases the secretion levels of cytokines and NO.

UPLC-Q-TOF/MS-based metabolomics reveals modulatory effects of Mesona chinensis Benth polysaccharide in liver injury mice induced by cyclophosphamide

The main purpose of this study was to investigate the improvement effect of Mesona chinensis Benth polysaccharide(MP)on cyclophosphamide(CTX)induced liver injury in mice.To explore metabolic profile of liver tissue and feces among normal group,CTX-induced group and MP management group based on metabolomics method by using UPLC-Q-TOF/MS.The results showed that MP could alleviate liver injury and promote the production of short chain fatty acids(SCFAs),with the best dose of 200 mg/kg·body weight(bw).The principal component analysis(PCA)and orthogonal partial least squares discriminant analysis(OPLSDA)scores plots of the liver and feces samples showed a clear separation among normal,model and highdose of MP(MPH).There were 18 endogenous metabolites in liver and 29 endogenous metabolites in feces,which were mainly involved in 8 metabolic pathways:taurine and hypotaurine metabolism,phenylalanine metabolism,α-linolenic acid metabolism,tricarboxylic acid(TCA)cycle,phenylalanine,tyrosine and tryptophan biosynthesis,arachidonic acid metabolism,sphingolipid metabolism as well as tryptophan metabolism.Moreover,a common metabolite arachidonic acid was observed in liver and feces samples.These endogenous metabolites may be considered to be MP’s response to liver protection.It will help to further understand the mechanism of MP and provide a basis for further research.

Apoptosis of colon cancer CT-26 cells induced polysaccharide from Cyclocarya paliurus and its phosphorylated derivative via intrinsic mitochondrial passway

In this study,the antitumor properties and the possible molecular mechanisms of Cyclocarya paliurus polysaccharide(CP)and its phosphorylated derivative(P-CP)on CT-26 mouse colon carcinoma cells were investigated.Results found that CP had high inhibition ratio against CT-26 cells.The flow cytometry results found that CP treatment could cause the intracellular acidification,arrest the cell cycle in the S phase and increase reactive oxygen species generation.Additionally,CP treatment triggered mitochondrial membrane potential depolarization and Ca^(2+)overloading,and broke down the balance of antioxidant system,Na^(+)/K^(+)-ATPase and Ca^(2+)-ATPase.Further analysis found CP induced cell apoptosis through improving the activities of caspase-3 and caspase-9,and increasing the level of cytochrome C.Furthermore,the comparative study of antitumor effect on CT-26 cells displayed that the phosphorylation enhanced antitumor activities of polysaccharides.These results suggest CP is a potential natural therapeutic agent for colon cancer and phosphorylation represents an effective method of enhancing the antitumor activity of CP.

Physicochemical, structural characterization, and antioxidant activities of chondroitin sulfate from Oreochromis niloticus bones

In this study,chondroitin sulfate was extracted from Oreochromis niloticus bones(OCS)and isolated to three fractions(OCS-1,OCS-2,and OCS-3).The physicochemical properties and structure characterization including monosaccharide,disaccharide compositions,molecular weight(Mw)of OCS were determined by HPAEC,HPLC-SAX,HPGPC,FT-IR spectra,and 1D/2D NMR.Moreover,their thermal properties,crystalline structure,and microstructure were also analyzed.Results showed that their Mw were between 10 kDa and 50 kDa.CS-6 was the predominant disaccharide unit in four OCS,and the CS-4/CS-6 ratios were close to CS from shark cartilage.Besides,the results of antioxidant activity showed that different fractions of OCS had a distinct DPPH radical,hydroxyl radical,and ABTS+radical scavenging activity.OCS-1 has the highest scavenging activities in DPPH and hydroxyl radical compared with other fractions,which showed a higher medicinal value.Those findings may lay some theoretical basis for the potential application development of OCS.

Hopf-flip bifurcation of high dimensional maps and application to vibro-impact systems

This paper addresses the problem of Hopf-flip bifurcation of high dimensional maps. Using the center manifold theorem, we obtain a three dimensional reduced map through the projection technique. The reduced map is further transformed into its normal form whose coefficients are determined by that of the original system. The dynamics of the map near the Hopf-flip bifurcation point is approximated by a so called “time-2τ^2 map” of a planar autonomous differential equation. It is shown that high dimensional maps may result in cycles of period two, tori T^1 （Hopf invariant circles）, tori 2T^1 and tori 2T^2 depending both on how the critical eigenvalues pass the unit circle and on the signs of resonant terms＇ coefficients. A two-degree-of-freedom vibro-impact system is given as an example to show how the procedure of this paper works. It reveals that through Hopf-flip bifurcations, periodic motions may lead directly to different types of motion, such as subharmonic motions, quasi-periodic motions, motions on high dimensional tori and even to chaotic motions depending both on change in direction of the parameter vector and on the nonlinear terms of the first three orders.

Mesona chinensis Benth polysaccharides alleviates liver injury by beneficial regulation of gut microbiota in cyclophosphamide-induced mice

There are a number of health benefits of Mesona chinensis Benth polysaccharide(MP),but little is known about its hepatoprotective effect and effect on gut microbiota composition in mice with liver damage induced by cyclophosphamide(CTX).This study indicated that MP supplementation effectively inhibited the production of serum aspartate aminotransferase(AST)and alanine aminotransferase(ALT),enhanced liver antioxidant capacity and repaired liver damage in mice caused by CTX.The release of inflammatory cytokines in liver and the concentration of lipopolysaccharide(LPS)in serum were decreased,and the level of short chain fatty acids(SCFAs)in colon was increased after MP administration.Those effects may be correlated with the regulation of the gut microbiota.Importantly,MP restrained liver inflammatory responses induced by CTX may via increasing the SCFAs-producing bacteria family Ruminococcaceae and reduced LPS-producing bacteria genus Bacteroides.In short,the prevention of CTX-induced liver injury by supplementing MP is achieved at least in part by regulating the community structure of the gut microbiota,and MP is expected to be a potential prebiotic to treat and prevent liver diseases.

Codimension two bifurcation and chaos of a vibro-impact forming machine associated with 1：2 resonance case

A vibro-impact forming machine with double masses is considered. The components of the vibrating system collide with each other. Such models play an important role in the studies of dynamics of mechanical systems with impacting components. The Poincaré section associated with the state of the impact-forming system, just immediately after the impact, is chosen, and the period n single-impact motion and its disturbed map are derived analytically. A center manifold theorem technique is applied to reduce the Poincaré map to a two-dimensional map, and the normal form map associated with codimension two bifurcation of 1：2 resonance is obtained, Unfolding of the normal form map is analyzed. Dynamical behavior of the impact-forming system, near the point of codimension two bifurcation, is investigated by using qualitative analyses and numerical simulation. Near the point of codimension two bifurcation there exists not only Neimark-Sacker bifurcation associated with period one single-impact motion, but also Neimark-Sacker bifurcation of period two double-impact motion. Transition of different forms of fixed points of single-impact periodic orbits, near the bifurcation point, is demonstrated, and different routes from periodic impact motions to chaos are also discussed.

Vibro-impact dynamics near a strong resonance point

Two typical vibratory systems with impact are considered, one of which is a two-degree-of-freedom vibratory system impacting an unconstrained rigid body, the other impacting a rigid amplitude stop. Such models play an important role in the studies of dynamics of mechanical systems with repeated impacts. Two-parameter bifurcations of fixed points in the vibro-impact systems, associated with 1 ： 4 strong resonance, are analyzed by using the center manifold and normal form method for maps. The single-impact periodic motion and Poincaré map of the vibro-impact systems are derived analytically. Stability and local bifurcations of a single-impact periodic motion are analyzed by using the Poincaré map. A center manifold theorem technique is applied to reduce the Poincaré map to a two-dimensional one, and the normal form map for 1：4 resonance is obtained. Local behavior of two vibro-impact systems, near the bifurcation points for 1：4 resonance, are studied. Near the bifurcation point for 1：4 strong resonance there exist a Neimark-Sacker bifurcation of period one single-impact motion and a tangent （fold） bifurcation of period 4 four-impact motion, etc. The results from simulation show some interesting features of dynamics of the vibro-impact systems： namely, the ＂heteroclinic＂ circle formed by coinciding stable and unstable separatrices of saddles, Tin, Ton and Tout type tangent （fold） bifurcations, quasi-periodic impact orbits associated with period four four-impact and period eight eight-impact motions, etc. Different routes of period 4 four-impact motion to chaos are obtained by numerical simulation, in which the vibro-impact systems exhibit very complicated quasiperiodic impact motions.

Symbolic dynamics of Belykh-type maps

The symbolic dynamics of a Belykh-type map （a two-dimensional discon- tinuous piecewise linear map） is investigated. The admissibility condition for symbol sequences named the pruning front conjecture is proved under a hyperbolicity condition. Using this result, a symbolic dynamics model of the map is constructed according to its pruning front and primary pruned region. Moreover, the boundary of the parameter region in which the map is chaotic of a horseshoe type is given.

Galactose-modified enzymatic synthesis of poly(amino-co-ester)micelles for co-delivery miR122 and sorafenib to inhibit hepatocellular carcinoma development

Nanomaterials as drug carriers hold promise for the treatment of carcinomas,but integrating multiple functions into a single vector is difficult.In this study,we aim to develop efficie nt materials as vectors for co-delivery of microRNA-122(miR-122)and sorafenib(SRF).We successfully synthesized amphiphilic galactose-modified PEGylated poly(ami no-co-ester)(Gal-PEG-PPMS)copolymers consisted of hydrophilic Gal-PEG5 k chain segments and hydrophobic poly(ω-pentadecalactone-co-N-methyldiethyleneamine-co-sebacic acid)chain segments,which self-assembled to form cationic micelles at pH 5.2.The results showed that the micelles could encapsulate SRF and bind miR122 simultaneously,increase cellular uptake efficiency.Furthermore,the micelles showed favorable transfection efficiency in enhancing miR122 expression level,the migration and invasion ability of hepatocellular carcinoma(HCC)cells we re significantly inhibited after being tra nsfected with miR122-loaded micelles.Most importantly,the co-delivery micelles decreased cell activities of HepG2 cells,which was more effective than miR122 or SRF loaded micelles alone.Collectively,Gal-PEG-PPMS nanoparticles are promising multifunctional carriers for miR122 and SRF co-delivery system to treat HCC.

Microfluidic integrated metamaterials for active terahertz photonics

A depletion layer played by aqueous organic liquids flowing in a platform of microfluidic integrated metamaterials is experimentally used to actively modulate terahertz(THz)waves.The polar configuration of water molecules in a depletion layer gives rise to a damping of THz waves.The parallel coupling of the damping effect induced by a depletion layer with the resonant response by metamaterials leads to an excellent modulation depth approaching 90%in intensity and a great difference over 210°in phase shift.Also,a tunability of slow-light effect is displayed.Joint time-frequency analysis performed by the continuous wavelet transforms reveals the consumed energy with varying water content,indicating a smaller moment of inertia related to a shortened relaxation time of the depletion layer.This work,as part of THz aqueous photonics,diametrically highlights the availability of water in THz devices,paving an alternative way of studying THz wave–liquid interactions and developing active THz photonics.

Food-derived bioactive peptides:production,biological activities,opportunities and challenges

Bioactive peptides(BPs)are multifunctional compounds derived from proteins,which exhibit different functions and show significant pharmacological effects.In the past few decades,the study on food-derived BPs had never been interrupted,and a wide range of BPs sequences have been identified due to its wide range of health benefit and multiple bioactivities,such as antioxidant,immune activity,anti-aging,anti-inflammatory activities.The bioactivities of BPs are mainly depend on the amino acid composition,size,sequence and physicochemical properties.What's more,BPs is reasonable and feasible as functional foods and pharmaceutical preparations to promote human health for its advantages of high safety,rich source,obvious physiological effect and easy digestion and absorption.However,there are many obstacles that limit the development of BPs.This review mainly summarizes the preparation methods,biological properties and applications of food-derived BPs.The opportunities and challenges of food-derived BPs as functional products are also disscussed.This review may provide a reference for the further utilization,deep processing and commercial development of food derived BPs.

Parameter calibration and experimental verification of discrete element simulation model for Protaetia brevitarsis larvae bioconversion mixture

To improve the survival rate of larvae during material separation after biotransformation of existing residual film mixtures of Protaetia brevitarsis larvae,this paper adopts the method of combining physical test and EDEM simulation test,and selects Hertz Mindlin with JKR contact model to calibrate the discrete element simulation contact parameters of the Protaetia brevitarsis larvae and the frass mixture.First,the cylinder lifting method was used to determine the actual repose angle of the mixture of larvae and frass.The collision recovery coefficients between larvae-frass and steel,static friction coefficient,kinetic friction coefficient and the collision recovery coefficient between larvae were measured through physical tests such as the inclined plane method.The Plackett-Burman test was then used to screen out the factors that have a significant impact on the repose angle:Poisson’s ratio of frass,frass-frass rolling friction coefficient,frass JKR surface energy,frass-larvae JKR surface energy.The optimal value intervals of four significant factors were determined based on the steepest climb test,Based on the Box-Behnken response surface analysis test,the second-order regression model between the repose angle and four significant factors was determined,and variance and interaction effects were analyzed.And with the actual repose angle as the goal,the significant factors were optimized and the optimal parameter combination of the four significant factors was determined.The simulation test of material repose angle and screening was carried out with the optimal parameter combination,and compared with the physical test.It was found that the maximum relative errors of the two tests were 1.48%and 3.79%respectively,indicating that the calibrated parameter values are true and reliable,It can provide a reference for the discrete element simulation of the transportation and separation of the Protaetia brevitarsis larvae-frass mixture.