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Background:Nuezhenide (NZD), an iridoid glycoside isolated from Ilex pubescens Hook. & Arn. var. kwangsiensis Hand.-Mazz., used as a traditional Chinese medicine for clearing Hook. & Arn. var. kwangsiensis Hand.-Mazz., used as a traditional Chinese medicine for clearing away heat and toxic materials, displays a variety of biological activities such as anti-tumor, antioxidant, and other life-protecting activities. However, a few studies involving anti-inflammatory activity and the mechanism of NZD have also been reported. In the present study, the anti-inflammatory and antioxidative effects of NZD are illustrated.Objective:This study aims to test the hypothesis that NZD suppresses LPS-induced inflammation by targeting the NF-κB pathway in RAW264.7 cells.Methods:LPS-stimulated RAW264.7 cells were employed to detect the effect of NZD on the release of cytokines by ELISA. Protein expression levels of related molecular markers were quantitated by western blot analysis. The levels of ROS, NO, and Ca2+were detected by flow cytometry. The changes in mitochondrial reactive oxygen species (ROS) and mitochondrial membrane potential (MMP) were observed and verified by fluorescence microscopy. Using immunofluorescence assay, the translocation of NF-κB/p65 from the cytoplasm into the nucleus was determined by confocal microscopy.Results:NZD exhibited anti-inflammatory activity and reduced the release of inflammatory cytokines such as nitrite, TNF-α, and IL-6. NZD suppressed the expression of the phosphorylated proteins like IKKα/β, IκBα, and p65. Besides, the flow cytometry results indicated that NZD inhibited the levels of ROS, NO, and Ca2+in LPS-stimulated RAW264.7 cells. JC-1 assay data showed that NZD reversed LPS-induced MMP loss. Furthermore, NZD suppressed LPS-induced NF-B/p65 translocation from the cytoplasm into the nucleus.Conclusions:NZD exhibits anti-inflammatory effects through the NF-κB pathway on RAW264.7 cells.

Based on the population model with an Allee effect, the corresponding delayed model is built up. According to the qualitative theory of differential equations, the model is analyzed completely to describe various intriguing dynamic properties as singular point of high order, Hopf bifurcation, etc. Next, combined impulse control theory with the ecological principles, the control models with impulse effects are proposed and the corresponding controllers are designed not only to avoid the extinction of the populations but also to prevent outbreak of the populations. The study would not only reveal the complexity dynamic behavior of ecosystems, but also provide the theory reference for the management of populations.

Atherosclerosis is a chronic inflammatory disease commonly seen in clinical practice. It can lead to thickening of vascular intima, occlusion of lumen stenosis and thrombosis, leading to angina pectoris, hypertension, myocardial infarction and other diseases, posing a serious threat to human life and health. This study provides a method for removing shield needles from graphene oxide thrombus and its preparation. The graphene oxide shield needle mainly includes flexible rotating shaft, radial flexible rod, rotating needle, adsorption main pipe and dosing main pipe, laser measuring device, high definition camera and other structures, which has the following advantages:firstly, it achieves multi-angle rotation grinding thrombosis, precise rotation grinding, avoids vascular damage and infection; secondly, thrombolytic drugs can be applied in the process of rotary grinding and small thrombus can be adsorbed to effectively avoid secondary embolization of blood vessels; thirdly, it a coating of graphene oxide on a rotating needle, which protects against bacteria and infection. This study has practical reference value for the development of thrombotherapy and the application of graphene in the medical field.

Inflammation is a complex physiological process that poses a serious threat to people’s health. However, the potential molecular mechanisms of inflammation are still not clear. Moreover, there is lack of effective anti-inflammatory drugs that meet the clinical requirement. Procyanidin A1 (PCA1) is a monomer component isolated from Procyanidin and shows various pharmacological activities. This study further demonstrated the regulatory role of PCA1 on lipopolysaccharide (LPS)-stimulated inflammatory response and oxidative stress in RAW264.7 cells. Our data showed that PCA1 dramatically attenuated the production of pro-inflammatory cytokines such as NO, iNOS, IL-6, and TNF-α in RAW264.7 cells administrated with LPS. PCA1 blocked IκB-α degradation, inhibited IKKα/β and IκBα phosphorylation, and suppressed nuclear translocation of p65 in RAW264.7 cells induced by LPS. PCA1 also suppressed the phosphorylation of JNK1/2, p38, and ERK1/2 in LPS-stimulated RAW264.7 cells. In addition, PCA1 increased the expression of HO-1, reduced the expression of Keap1, and promoted Nrf2 into the nuclear in LPS-stimulated RAW264.7 cells. Cellular thermal shift assay indicated that PCA1 bond to TLR4. Meanwhile, PCA1 inhibited the production of intracellular ROS and alleviated the depletion of mitochondrial membrane potential in vitro. Collectively, our data indicated that PCA1 exhibited a significant anti-inflammatory effect, suggesting that it is a potential agent for the treatment of inflammatory diseases.

The chemical composition and antitumor activity of essential oil were compared for four parts of the Arisaema Amuremse Maxim. Chemical constituent of essential oil in every parts of Arisaema Amuremse Maxim was identified by GC-MS analysis systematically. Arisaema Amuremse Maxim had 114 kinds of essential oils. Tubers, petioles, leaves, and fruits were identified 53, 48, 5 and 21 species essential oil, respectively. The antiproliferative activity against Hep2, HCT-116, A549, SW480, HepG2 cell lines had been investigated by MTT assay. The essential oil of tubers, petioles, leaves and fruits all had strong antiproliferative activity. The IC 50 was 19.60μg·mL-1, 17.60μg·mL-1, 23.80μg·mL-1, and 30.23μg·mL-1, respectively. Among them, the essential oil of tubers and petioles had stronger antitumor activity. The essential oil of tubers, petioles, leaves and fruits had strong antiproliferative activity. This study was of great significance to increase the medicinal parts of Arisaema Amuremse Maxim.

OBJECTIVE To investigate inhibitory effect of semen litchi drug serum on proliferation of human hepatoma HepG2 cells and its effect on the expression of vascular endothelial growth factor (VEGF) and matrix metalloproteinase-9 (MMP-9). STUDY DESIGN An experimental study. PLACE AND DURATION OF STUDY College of Pharmacy, Guangxi University of Chinese Medicine, China, from June 2017 to January 2018. METHODOLOGY Semen litchi drug serum with concentrations of 0 mg/kg (control group), 3 g/kg (low dose group), 6 g/kg (medium dose group) and 12 g/kg (high dose group) was used to act on HepG2 cells at the logarithmic phase. Inhibitory effect of semen litchi drug serum on cell growth, expression of VEGF and MMP-9 mRNA and protein was detected. RESULTS Inhibitory effect of semen litchi drug serum on the proliferation of HepG2 cells significantly increased with the increase of drug concentration, which was dose-time dependent. Expression levels of VEGF and MMP-9 mRNA in HepG2 cells after 48 hours of treatment by semen litchi low-dose group, medium-dose group, and high-dose group were lower than those in control group (all p

BACKGROUND The aim of this study was to assess the hypoglycemic effect of Cyclocarya paliurus extract (CPE) on diabetes mellitus (DM) mice. MATERIAL AND METHODS A DM mouse model was established to test FBG, TC, and TG. The DM mice were divided into 3 groups: a DM group, a DM+CPE (0.5 g/Kg) group, and a DM+CPE (1.0 g/Kg) group. The FBG and body weight were measured. The glucose tolerance ability was determined by OGTT test. FINS was measured to calculate ISI and IRI. Serum MDA, SOD, and GSH-Px levels were detected. NIT-1 cells were cultured in vitro and divided into 4 groups: a control group, a STZ group, a STZ+CPE (80 μg/mL) group, and a STZ+CPE (160 μg/mL) group. Cell apoptosis and ROS content were assessed by flow cytometry. Cell proliferation was detected by EdU staining. RESULTS Compared with the control group, FBG, TC, and TG were significantly increased in the DM group. CPE gavage obviously reduced FBG level, increased body weight, enhanced glucose tolerance, elevated FINS level and ISI, and reduced IRI, all in a dose-dependent manner. CPE gavage reduced serum MDA content and increased SOD and GSH-Px enzyme activities in DM mice. STZ markedly enhanced ROS production, induced apoptosis, and inhibited proliferation in NIT-1 cells. CPE treatment clearly reduced ROS production and apoptosis, enhanced cell proliferation, and alleviated STZ damage to NIT-1 cells. CONCLUSIONS CPE has the effects of decreasing blood glucose and insulin resistance, and enhancing glucose tolerance in DM mice, which may be related to its effects of reducing oxidation and reduced apoptosis, and relieving STZ in pancreatic beta cell injury.

Procyandin A2 (PCA2) is a polyphenolic compound which is isolated from grape seeds. It has been reported that PCA2 exhibits antioxidative and anti-inflammatory effects, but its molecular mechanism is still poorly understood. This study tests the hypothesis that PCA2 suppresses lipopolysaccharide (LPS)-induced inflammation and oxidative stress through targeting the nuclear factor-κB (NF-κB), mitogen-activated protein kinase (MAPK), and NF-E2-related factor 2 (Nrf2) pathways in RAW264.7 cells. PCA2 (20, 40, 80 μM) exhibited no significant cytotoxicity in RAW264.7 cells and showed an inhibitory effect on an LPS-induced nitrite level. Pro-inflammatory cytokines like tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), prostaglandin E2 (PGE2), nitric oxide (NO), and reactive oxygen species (ROS) were suppressed by PCA2 with a concentration range of 0-80 μM. The mRNA levels of TNF-α and IL-6 were inhibited by PCA2 (80 μM). The hallmark-protein expression of the NF-κB (p-IKKα/β, p-IκBα, and p-p65) and MAPK (p-p38, p-JNK, and p-ERK) pathways were decreased by PCA2 in LPS-stimulated RAW264.7 cells. In addition, immunofluorescence results indicated that PCA2 (80 μM) promoted the translocation of NF-κB/p65 from the cytoplasm into the nucleus. PCA2 upregulated the expressions of Nrf2 and HO-1 and downregulated the expression of Keap-1. Simultaneously, PCA2 (80 μM) reversed LPS-induced Nrf2 translocation from the nucleus into the cytoplasm. Collectively, PCA2 protect cells against the damage from inflammation and oxidative injury, which suggest a potential therapeutic strategy for inflammatory and oxidative stress through targeting NF-κB, MAPK, and Nrf2 pathways in RAW264.7 cells.

Background Astrocyte elevated gene-1 (AEG-1), also known as metadherin, 3D3, and lysine-rich carcinoembryonic antigen-related cell adhesion molecule 1 (CEACAM1) coisolated, has emerged as an important oncogene that is overexpressed in a variety of cancers. Previous studies revealed that AEG-1 is also involved in multiple physiological and pathological processes, such as development, inflammation, neurodegeneration, migraine, and Huntington's disease. However, the function of AEG-1 in diabetic cardiomyopathy (DCM) has not been reported yet. Therefore, we conducted this study to characterize the potential role and mechanism of AEG-1 in DCM rats. Methods DCM was induced by injections of streptozocin (STZ) in Wistar rats. Rats were randomized to be injected with lentivirus carrying AEG-1 small interfering RNA. Haemodynamic changes of Wistar rats, assessment of cardiac weight index, and the expression of AEG-1 and KLF4 were detected and compared among these three groups. Results The expressions of AEG-1 and KLF4 in the STZ group were significantly elevated in cardiac tissues compared with the control group. Knockdown of AEG-1 significantly increased the values of left ventricular ejection fraction, ±dp/dt max , repressed autophagy, as well as upregulated the expression of KLF4. Conclusions Knockdown of AEG-1 suppresses autophagy in DCM by downregulating the expression of KLF4. This study provide first-notion evidence for the potential value of AEG-1 as a therapeutic target for the treatment of the patients with DCM.

The aim of this study was to determine the effect of Astragalus polysaccharide (APS) on the expression of vascular endothelial growth factor (VEGF) and epidermal growth factor receptor (EGFR) in mice with Lewis transplantable lung cancer. It was an experimental study carried out from June 2017 to January 2018 at the College of Pharmacy, Guangxi University of Chinese Medicine, Nanning, China. Forty male SPF-level C57BL/6J mice were selected and inoculated with Lewis lung cancer cell suspension in the right axilla of the mice to establish a lung-cancer mouse model. The mice were randomly divided into a model control group and APS groups with high, middle and low dosages, respectively, 10 in each group. After inoculation of Lewis tumor cell suspension for 2 days, mice in the model control group were injected intraperitoneally with 50 mL/kg of 0.9% sodium chloride solution, whereas, mice in the APS groups with high, middle and low dosages were intraperitoneally injected with APS at 100, 50, 25 mg/kg, respectively. The research results showed that APS can effectively inhibit the growth and metastasis of Lewis lung cancer in mice, improve immune organ function, inhibit the protein expression of VEGF and EGFR in tumor tissues, and have a concentration-effect relationships.

Objectives A system of stearic acid (SA)-modified Bletilla striata polysaccharide (BSP) micelles was developed for the targeted delivery of docetaxel (DTX) as a model anticancer drug (DTX-SA-BSP). Methods Particle size, zeta potential and DTX release in vitro were measured in release media at different pH values. Quantitative cellular uptake, cytotoxicity assay in vitro and antitumour efficacy in vivo were also evaluated. Cell apoptosis was assessed by flow cytometry. Key findings DTX-SA-BSP copolymer micelles displayed pH-dependent properties in the respects of particle size, zeta potential and in vitro release behaviour ranging from pH 5.0 to pH 7.4. DTX-SA-BSP copolymer micelles showed higher release rate at pH 5.0 than that at pH 6.0 and 7.4. In vitro cytotoxic effect of DTX-SA-BSP copolymer micelles was higher than that of DTX injection. The results of high-performance liquid chromatography determination confirmed that DTX cellular uptake of micelles was enhanced compared with that of DTX injection. Anticancer activity in vivo further confirmed the enhanced tumour targeting and anticancer efficacy of DTX-SA-BSP copolymer micelles. Conclusions The above results show that DTX-SA-BSP copolymer micelles have pH sensitivity. SA-BSP copolymers are a promising carrier for delivering hydrophobic anticancer drugs.

Celiac disease (CD) is one of the most common human intestinal malabsorption diseases. The only effective treatment for patients with CD is to follow a gluten-free (GF) diet strictly. Nowadays, the increasing incidence of CD promotes worldwide interests for various desirable GF products. However, baking without gluten, the key ingredient for bread structure and quality, is a big challenge for all bakers and cereal researchers. Several approaches have been applied to understand and improve gluten-free bread (GFB) elaboration and further studies are still required. The main focus of this review is to discuss the approaches for GFB improvements in recent 5 years, including the use of novel alternative flours, functional ingredients, processing aids, additives, innovative techniques, and their combinations.

The aim of this study was to prepare dissolving microneedles (DMNs) patches containing tranexamic acid (TA) for the treatment of melasma. Polyvinyl alcohol (PVA) and polyvinylpyrrolidone (PVP) were preferred as matrix materials through the compatibility experiment. In the in vitro permeation study, the transdermal amount of TA was significantly promoted through dissolving microneedles with the cumulative release was 44.43 ± 6.55%. By comparison, the release of TA solution assisted with solid microneedles (SMNs) was merely 11.31 ± 2.30% (p 0.05). Pharmacokinetics study indicated the bioavailability of dissolving microneedles was more than 1.3 times compared with oral administration. In pharmacodynamics investigation, TA dissolving microneedles obviously reduced melanin deposition in the skin of melasma guinea pigs after 8 consecutive administrations. In particular, the combination of tranexamic acid and licorice extract (LIC) dissolving microneedles worked better than tranexamic acid alone. Accelerated stress conditions including high temperature, high humidity, as well as photostability were designed to prove that TA microneedles maintained good pharmaceutical stability. In conclusion, tranexamic acid dissolving microneedles showed reliable quality and remarkable effect. Moreover, the combination of tranexamic acid and licorice extract had a synergistic therapy in melasma.

Aphids are a major global wheat pest that can cause considerable loss of yield. Modeling of aphid population dynamics is an integral part of management strategies to manage or control aphid populations. In this paper, first, a wheat aphid population dynamics model was developed based on a logistic model and the Holling III functional response, which includes three factors: temperature, natural enemies and insecticide. Second, this model fitted with a cusp catastrophe model to describe how abrupt changes in the wheat aphid population were influenced by these factors. Finally, the system was validated with field data from 2016 to 2018. The bifurcation set of the cusp catastrophe model was deemed to be the quantified dynamic control threshold, so an outbreak of aphid’s population can be explained according to the variation of control variables. In short, this aphid population model was successfully validated on survey data, which can be used to guide the prevention and control of aphids.

In the separation of strongly polar antioxidant compounds from natural products using high-speed counter-current chromatography that is target-guided by 2,2-diphenyl-1-picrylhydrazyl high-performance liquid chromatography experimentation, low adsorption ability is encountered due to the strong polarity of the target compounds. In this study, a strategy of novel partition coefficient value calculation was proposed for overcoming this problem. The partition coefficient value was expressed as the ratio of the antioxidant activities of the upper phase and the lower phase. This strategy was used in high-speed counter-current chromatography with a hydrophilic organic/salt-containing aqueous two-phase system for bioassay-guided separation of strongly polar antioxidant compounds from Lycium barbarum L. The antioxidant activity was determined via the radical scavenging activity method using 2,2-diphenyl-1-picrylhydrazyl radicals. A hydrophilic organic/salt-containing aqueous two-phase system of 95% EtOH - sat. (NH4)2SO4 (1:1.8, v/v) was successfully used to separate Lycium barbarum L. extract. Five fractions were collected via high-speed counter-current chromatography separation. The antioxidant activity of the third fraction was the highest. Three compounds were separated via MCI gel column chromatography and Sephadex LH-20 column chromatography from the third fraction, and their antioxidant activities were determined. The antioxidant activities of the three compounds were higher than that of the third fraction. These results demonstrate that this strategy can be used to separate strongly polar antioxidant compounds from natural products.

According to logistic model, a model is firstly proposed to describe the interaction between the strawberry population and the aphid populations. The qualitative analysis is given to reveal the dynamic behavior of the model. Based on the neutral network, the corresponding T-S fuzzy model is constructed and the controller is designed to reduce the harm caused by the aphid populations. Finally, some numerical simulations are carried out to prove the results.

Magnetic nanocomposites have been well recognized as promising candidates for enzyme immobilization, DNA extraction, targeted drug delivery, and removal of various metal ions. In this paper, dedoped Fe 3 O 4 /PPy nanocomposite has been obtained by simple ammonia-washing of the newly-formed Fe 3 O 4 nanoferrofluid/PPy derived from in situ polymerization approach. The magnetic nanocomposite is characterized with XRD, FT-IR, TEM, BET, zeta potential, and magnetometry techniques, and further tested in the role of separating Ag(I) from mixed metal-ion solutions containing Ag(I), Mg(II), Cu(II), Zn(II), As(III), and Pb(II). The adsorption of Ag(I) upon dedoped Fe 3 O 4 /PPy is an endothermic and spontaneous chemisorption process, ensuring rapid separation of Ag(I) from aqueous solution. The maximum adsorption capacity of Ag(I) upon dedoped Fe 3 O 4 /PPy is 143.3 mg g −1 . The total adsorption process preferably follows the Langmuir model and the pseudo-second order kinetics. Mg(II), Cu(II), Zn(II), and As(III) have minor effects whereas Pb(II) has a relatively remarkable effect on selective separation of Ag(I) from solutions. The magnetic nanocomposite is featured with superparamagnetism, a multicore–shell structure, a soft-base surface, excellent reusability, and a high anti-interfering ability for selective separation of Ag(I) from multiionic solutions, presenting a promising candidate for practical application in selective separation of Ag(I) from silver-containing emissions.

s Magnetic composite nanospheres carrying amino groups have attracted much interest due to their potential applications in the fields of catalysis, sensor, water purification, enzyme immobilization, DNA extraction, and drug delivery. In this paper, dedoped Fe 3 O 4 /polypyrrole (PPy) nanospheres with core–shell structure, high magnetization, superparamagnetism, and size meeting the demand of biorelated applications in vivo have been achieved by an in situ polymerization approach. The amount of the surface amino groups of Fe 3 O 4 /PPy is greatly enhanced by dedoping treatment due to liberation of the amino groups ever sheltered by the dopants, a situation that is responsible for facile conjugation of fluorescein and methotrexate (MTX) onto the magnetic composite through the EDC/NHS coupling chemistry to produce the desirable fluorescent Fe 3 O 4 /PPy/MTX targeting drug with a high MTX loading of ca. 109 μg mg −1 . The as-obtained magnetic targeting drug exhibits controlled drug release, enhanced intracellular drug retention, and specific targeting ability to HeLa cells, presenting a promising candidate for treatment of cancer cells overexpressing folate receptors.

Considering the change of the parameter related to the natural enemy population and the impact on the aphid populations in the fold catastrophe manifold, the singular system model of aphid ecosystems is proposed. Combining singular system theory with catastrophe theory, the corresponding dynamics behaviors and the existence conditions of the impasse points are given by using the qualitative analysis. The biological significance of the analytical results is also discussed. The controllers are designed to make the aphid populations stabilize the refuge level by releasing natural enemy. Some numerical simulations are carried out to prove the results.

Using the geometry theory of differential equations, the conditions of the existence of periodic solution to a prey-predator model with impulsive effects are given. The optimal control of the model is studied by optimal control principle of impulsive differential equations. The optimal harvesting time and corresponding optimal harvesting level which make people get the maximum profit are obtained. Finally, the simulations are exerted to prove the results.

Magnetic composite microspheres present a promising candidate for applications in water treatment, enzyme immobilization, drug delivery, catalysis, and sensors. In this paper, we report on the surfactant-free synthesis of well-defined Fe 3 O 4 /PANI microspheres through an interfacial polymerization approach. The as-prepared magnetic composite spheres show good dispersion, core–shell structure, and high magnetization. Also, the Fe 3 O 4 /PANI microspheres were tested as an adsorbent to remove Cr(VI) ions from water, and were found to have a strong adsorption capacity of ca. 200 mg g −1 . The adsorption isotherm for Cr(VI) adsorption on Fe 3 O 4 /PANI microspheres follows the Langmuir isotherm model, and the adsorption process meets the pseudo-second-order kinetics. After reuse five times, the adsorption capacity of Fe 3 O 4 /PANI microspheres retains 90% of the initial value, indicating that the Fe 3 O 4 /PANI microspheres can serve as an excellent regenerable Cr(VI) adsorbent.

Based on the model of bubonic plague, the corresponding stochastic model with stochastic disturbances is given. According to the data of bubonic plague from the World Health Organization, the coefficient matrices and noise intensity of the model are obtained by subspace identification method. Finally, the simulations are carried out to prove that the subspace identification is more accurate than Bayesian maximum entropy (BME) method.

Based on Logistic model, the corresponding management model of fishery with two impulsive effects is proposed. Using the principles of optimization impulsive control and optimal theory, the controllers are designed to get the harvest moments and the corresponding levels. It not only can make the fishermen get the maximum revenue, but also can ensure the sustainable utilization of fishery. Finally, the numerical simulation are carried out to prove the results.

Using successor functions and Poincaré-Bendixson theorem of impulsive differential equations, the existence of periodical solutions to a predator-prey model with two state impulses is investigated. By stability theorem of periodic solution to impulsive differential equations, the stability conditions of periodic solutions to the system are given. Some simulations are exerted to prove the results.

In this paper, a non-smooth population model with impulsive effects is proposed by combining discontinuity and non-smoothness. According to the qualitative theory of differential equations, the global analysis of the model is discussed. Using the theory of impulsive differential equations, the existence conditions of order one periodic solution are obtained. And the impulsive controllers are designed to make the pest populations stay at the refuge level. Some simulations are carried out to prove the results.

We present an analytical solution of groundwater head response to tidal fluctuation in a coastal multilayered aquifer system consisting of an unconfined aquifer, a leaky confined aquifer and a semi-permeable layer between them. The submarine outcrop of the confined aquifer is covered by a thin silt layer. A mathematical model and the analytical solution of this model are given. The silt layer reduces the amplitude of the hydraulic head fluctuation by a constant factor, and shifts the phase by a positive constant (time lag), both of which depend on the leakances of the silt layer and the semi-permeable layer. The time lag is less than 1·5 h and 3·0 h for semi-diurnal and diurnal sea tides respectively. When the leakance of the semi-permeable layer or the silt layer assumes certain special values, the solution becomes the existing solutions derived by previous researchers. The amplitude of the hydraulic head fluctuation in the confined aquifer increases with the leakance of the silt layer and decreases with the leakance of the semi-permeable layer, whereas the phase shift of the fluctuation decreases with both of them. A hypothetical example shows that neglecting the silt layer may result in significant parameter estimation discrepancy between the amplitude attenuation and the time-lag fittings. Copyright © 2007 John Wiley & Sons, Ltd.

In this paper, the dynamical behaviors and chaos control are investigated in a discrete functional response model. It is verified that there are phenomena of the transcritical bifurcation, flip bifurcation, Hopf bifurcation types and chaos in the sense of Marotto’s definition. Specifically, a controller is designed to stabilize the chaotic orbits and enable them to be an ideal target one (i.e., an unstable fixed point of the chaotic system). Finally, numerical simulations not only show the consistency with theoretical analysis but also exhibit the complex dynamical behaviors.

Based on the fold catastrophe model for the aphid population ecosystem, the corresponding management model with impulsive effects is given by using the chemical controls like spraying pesticide. According to the principle of optimization impulsive control, the optimization moments of spraying pesticide and the corresponding level of the aphid population are obtained. The simulations are carried out to prove the results.