Coronaviruses have been closely related with mankind for thousands of years. Communityacquired human coronaviruses have long been recognized to cause common cold. However,zoonotic coronaviruses are now becoming more a...Coronaviruses have been closely related with mankind for thousands of years. Communityacquired human coronaviruses have long been recognized to cause common cold. However,zoonotic coronaviruses are now becoming more a global concern with the discovery of highly pathogenic severe acute respiratory syndrome(SARS) and Middle East respiratory syndrome(MERS) coronaviruses causing severe respiratory diseases. Infections by these emerging human coronaviruses are characterized by less robust interferon production. Treatment of patients with recombinant interferon regimen promises beneficial outcomes, suggesting that compromised interferon expression might contribute at least partially to the severity of disease. The mechanisms by which coronaviruses evade host innate antiviral response are under intense investigations. This review focuses on the fierce arms race between host innate antiviral immunity and emerging human coronaviruses. Particularly, the host pathogen recognition receptors and the signal transduction pathways to mount an effective antiviral response against SARS and MERS coronavirus infection are discussed. On the other hand, the counter-measures evolved by SARS and MERS coronaviruses to circumvent host defense are also dissected. With a better understanding of the dynamic interaction between host and coronaviruses, it is hoped that insights on the pathogenesis of newly-identified highly pathogenic human coronaviruses and new strategies in antiviral development can be derived.展开更多
The main purpose of this paper is to study the persistence of the general multispecies competition predator-pray system with Holling Ⅲ type functional response. In this system, the competition among predator species ...The main purpose of this paper is to study the persistence of the general multispecies competition predator-pray system with Holling Ⅲ type functional response. In this system, the competition among predator species and among prey species are simultaneously considered. By using the comparison theory and qualitative analysis, the sufficient conditions for uniform strong persistence are obtained.展开更多
In this study, the impulsive predator-prey dynamic systems on time scales calculus are studied. When the system has periodic solution is investigated, and three different conditions have been found, which are necessar...In this study, the impulsive predator-prey dynamic systems on time scales calculus are studied. When the system has periodic solution is investigated, and three different conditions have been found, which are necessary for the periodic solution of the predator-prey dynamic systems with Beddington-DeAngelis type functional response. For this study the main tools are time scales calculus and coincidence degree theory. Also the findings are beneficial for continuous case, discrete case and the unification of both these cases. Additionally, unification of continuous and discrete case is a good example for the modeling of the life cycle of insects.展开更多
In this paper,we consider the positive steady state solutions of a predator-prey model with Holling type Ⅱfunctional response and cross-diffusion,where two cross-diffusion rates represent the tendency of prey to keep...In this paper,we consider the positive steady state solutions of a predator-prey model with Holling type Ⅱfunctional response and cross-diffusion,where two cross-diffusion rates represent the tendency of prey to keep away from its predator and the tendency of the predator to chase its prey,respectively.Applying the fixed point index theory,some sufficient conditions for the existence of positive steady state solutions are established.Furthermore,the non-existence of positive steady state solutions is studied.展开更多
Background:This study aimed to assess how acupoint catgut-embedding therapy influences Th2-type immune response and the infiltration of CD4^(+)and CD8^(+)cells in DNCB-induced atopic dermatitis in BALB/c mice.It also ...Background:This study aimed to assess how acupoint catgut-embedding therapy influences Th2-type immune response and the infiltration of CD4^(+)and CD8^(+)cells in DNCB-induced atopic dermatitis in BALB/c mice.It also conducted an initial examination of the underlying molecular mechanisms.Methods:Seventy-two mice were randomly divided into four groups:normal control,DNCB-induced atopic dermatitis model(AD),AD with acupoint catgut-embedding treatment(ADA),and AD with sham-acupoint catgut-embedding treatment.After DNCB challenge to induce AD,the ADA group received acupoint catgut-embedding therapy treatment at Zusanli(ST 36)and Quchi(LI 11)acupoints every other week from day 8.Mice in the AD with sham-acupoint catgut-embedding treatment group underwent the same procedure as the ADA group but without catgut implantation.Severity was assessed using SCORAD on treatment days 1,10,and 20.On day 18,nine mice per group were euthanized,and the remaining on day 28.Histopathological changes were observed using hematoxylin-eosin and immunohistochemistry staining.TNF-α,IL-4,IL-6,and IL-13 levels were analyzed by ELISA,and GATA3 and STAT6 protein levels by western blot.Results:After 20 days of acupoint catgut-embedding therapy treatment,mice showed reduced dermatitis scores compared to DNCB-induced AD-like mice.Significant decreases occurred in serum IL-4,IL-6,IL-13,and TNF-αlevels.Skin analysis revealed marked reductions in CD4^(+)and CD8^(+)cell infiltration,as well as GATA3 and STAT6 protein levels.Conclusion:Acupoint catgut-embedding therapy may effectively alleviate atopic dermatitis by suppressing Th2 immune responses via the STAT6-GATA3 pathway and reducing CD4^(+)and CD8^(+)T cell infiltration in skin lesions.展开更多
The effect of endosulfan, a hexachlorinated pesticide, on growth, inorganic nitrogenous nutrient uptake (NO3-, NO2- and NH4+), change in pigmentation and glycogen content on wild type and chemically mutagenised cells ...The effect of endosulfan, a hexachlorinated pesticide, on growth, inorganic nitrogenous nutrient uptake (NO3-, NO2- and NH4+), change in pigmentation and glycogen content on wild type and chemically mutagenised cells of Synechococcus cedrorum was investigated. The pattern of response to pesticide stress in wild and mutant type was the same. Growth reappeared in both after a period of initial lag in presence of endosulfan. The duration of lag increased with increasing doses of pesticide. Paradoxically, however, the rate of uptake of NO-3, NO-2 and NH+4 pigment and glycogen content progressively increased with increasing doses. The difference in the adaptation response between wild and mutant types was observed only in the concentration of pesticide that could be tolerated; with the mutant tolerating 2.5 fold more.展开更多
A class of Beddington-DeAngelis＇ type predator-prey dynamic system with prey and predator both having linear density restriction is considered. By using the qualitative methods of ODE, the existence and uniqueness of...A class of Beddington-DeAngelis＇ type predator-prey dynamic system with prey and predator both having linear density restriction is considered. By using the qualitative methods of ODE, the existence and uniqueness of positive equilibrium and its global asymptotic stability are analyzed. The direct criterions for local stability of positive equilibrium and existence of limit cycle are also established when inference parameter of predator is small.展开更多
In this paper,a discrete Lotka-Volterra predator-prey model is proposed that considers mixed functional responses of Holling types I and III.The equilibrium points of the model are obtained,and their stability is test...In this paper,a discrete Lotka-Volterra predator-prey model is proposed that considers mixed functional responses of Holling types I and III.The equilibrium points of the model are obtained,and their stability is tested.The dynamical behavior of this model is studied according to the change of the control parameters.We find that the complex dynamical behavior extends from a stable state to chaotic attractors.Finally,the analytical results are clarified by some numerical simulations.展开更多
Consider a class of Ivlev＇s type predator-prey dynamic systems with prey and predator both having linear density restricts. By using the qualitative methods of ODE, the global stability of positive equilibrium and ex...Consider a class of Ivlev＇s type predator-prey dynamic systems with prey and predator both having linear density restricts. By using the qualitative methods of ODE, the global stability of positive equilibrium and existence and uniqueness of non-small amplitude stable limit cycle are obtained. Especially under certain conditions, it shows that existence and uniqueness of non-small amplitude stable limit cycle is equivalent to the local un-stability of positive equilibrium and the local stability of positive equilibrium implies its global stability. That is to say, the global dynamic of the system is entirely determined by the local stability of the positive equilibrium.展开更多
The polarization of macrophages to the M1 or M2 phenotype has a pivotal role in inflammation and host defense;however,the underlying molecular mechanism remains unclear.Here,we show that myocyte enhancer factor 2 C(ME...The polarization of macrophages to the M1 or M2 phenotype has a pivotal role in inflammation and host defense;however,the underlying molecular mechanism remains unclear.Here,we show that myocyte enhancer factor 2 C(MEF2C)is essential for regulating M1 macrophage polarization in response to infection and inflammation.Global gene expression analysis demonstrated that MEF2C deficiency in macrophages downregulated the expression of M1 phenotypic markers and upregulated the expression of M2 phenotypic markers.MEF2C significantly promoted the expression of interleukin-12 p35 subunit(Il12a)and interleukin-12 p40 subunit(Il12b).Myeloid-specific Mef2c-knockout mice showed reduced IL-12 production and impaired Th1 responses,which led to susceptibility to Listeria monocytogenes infection and protected against DSS-induced IBD in vivo.Mechanistically,we showed that MEF2C directly activated the transcription of Il12a and Il12b.These findings reveal a new function of MEF2C in macrophage polarization and Th1 responses and identify MEF2C as a potential target for therapeutic intervention in inflammatory and autoimmune diseases.展开更多
The type 2 immune response is critical for host defense against large parasites such as helminths.On the other hand,dysregulation of the type 2 immune response may cause immunopathological conditions,including asthma,...The type 2 immune response is critical for host defense against large parasites such as helminths.On the other hand,dysregulation of the type 2 immune response may cause immunopathological conditions,including asthma,atopic dermatitis,rhinitis,and anaphylaxis.Thus,a balanced type 2 immune response must be achieved to mount effective protection against invading pathogens while avoiding immunopathology.The classical model of type 2 immunity mainly involves the differentiation of type 2 T helper(Th2)cells and the production of distinct type 2 cytokines,including interleukin-4(IL-4),IL-5,and IL-13.Group 2 innate lymphoid cells(ILC2s)were recently recognized as another important source of type 2 cytokines.Although eosinophils,mast cells,and basophils can also express type 2 cytokines and participate in type 2 immune responses to various degrees,the production of type 2 cytokines by the lymphoid lineages,Th2 cells,and ILC2s in particular is the central event during the type 2 immune response.In this review,we discuss recent advances in our understanding of how ILC2s and Th2 cells orchestrate type 2 immune responses through direct and indirect interactions.展开更多
COVID-19 is caused by SARS-CoV-2.1 As of July 16th,2020,there were 13,579,581 diagnosed cases and 584,782 deaths attributed to COVID-19 reported globally(https://coronavirus.jhu.edu/map.html).
In mammals,mitofusin 2(MFN2)is involved in mitochondrial fusion,and suppresses the virus-induced RIG-I-like receptor(RLR)signaling pathway.However,little is known about the function of MFN2 in non-mammalian species.In...In mammals,mitofusin 2(MFN2)is involved in mitochondrial fusion,and suppresses the virus-induced RIG-I-like receptor(RLR)signaling pathway.However,little is known about the function of MFN2 in non-mammalian species.In the present study,we cloned an MFN2 ortholog(LcMFN2)in large yellow croaker(Larimichthys crocea).Phylogenetic analysis showed that MFN2 emerged after the divergence of amphioxus and vertebrates.The protein sequences of MFN2 were well conserved from fsh to mammals.LcMFN2 was expressed in all the tissues/organs examined at diferent levels,and its expression was upregulated in response to poly(I:C)stimulation.Overexpression of LcMFN2 inhibited MAVS-induced type I interferon(IFN)promoter activation and antiviral gene expression.In contrast,knockdown of endogenous LcMFN2 enhanced poly(I:C)induced production of type I IFNs.Additionally,LcMFN2 enhanced K48-linked polyubiquitination of MAVS,promoting its degradation.Also,overexpression of LcMFN2 impaired the cellular antiviral response,as evidenced by the increased expression of viral genes and more severe cytopathic efects(CPE)in cells infected with spring viremia of carp virus(SVCV).These results indicated that LcMFN2 inhibited type I IFN response by degrading MAVS,suggesting its negative regulatory role in cellular antiviral response.Therefore,our study sheds a new light on the regulatory mechanisms of the cellular antiviral response in teleosts.展开更多
Cytokinins(CKs)are one of the important classes of plant hormones essential for plant growth and devel-opment.TATA-box binding protein-associated factor 12b(TAF12b)is involved in CK signaling,but its molecular and bio...Cytokinins(CKs)are one of the important classes of plant hormones essential for plant growth and devel-opment.TATA-box binding protein-associated factor 12b(TAF12b)is involved in CK signaling,but its molecular and biochemical mechanisms are not fully understood.In this study,TAF12b of Nicotiana ben-thamiana(NbTAF12b)was found to mediate the CK response by directly interacting with type B response regulators(B-RRs),positive regulators of CK signaling,and inhibiting their transcriptional activities.As a transcriptional co-factor,TAF12b specifically facilitated the proteasomal degradation of non-phosphorylated B-RRs by recruiting the KISS ME DEADLY family of F-box proteins.Such interactions between TAF12b and B-RRs also occur in other plant species.Genetic transformation experiments showed that overexpression of NbTAF12b attenuates the CK-hypersensitive phenotype conferred by NbRR1 over-expression.Taken together,these results suggest a conserved mechanism in which TAF12b negatively regulates CK responses by promoting 26S proteasome-mediated B-RR degradation in multiple plant spe-cies,providing novel insights into the regulatory network of CK signaling in plants.展开更多
The main purpose of this paper is to explore the existence of positive periodic solutions to impulsive predator-prey systems with type IV functional responses. Sufficient criteria are obtained for the existence of str...The main purpose of this paper is to explore the existence of positive periodic solutions to impulsive predator-prey systems with type IV functional responses. Sufficient criteria are obtained for the existence of strictly positive periodic solutions. The approach is based on a continuation theorem in the coincidence degree theory as well as some prior estimates. This is also the first time that multiple positive periodic solutions are obtained using coincidence degree theory in impulsive ecological systems.展开更多
In this paper, we consider a nonautonomous multispecies competition-predator system with Holling＇s type Ⅲ functional response. The coexistence of the system, under some conditions, is obtained. Furthermore, using Ly...In this paper, we consider a nonautonomous multispecies competition-predator system with Holling＇s type Ⅲ functional response. The coexistence of the system, under some conditions, is obtained. Furthermore, using Lyapunov function, we show that the system has a strictly positive almost periodic solution which is globally asymptotically stable.展开更多
Epithelial-derived cytokines,especially type 2 alarmins(TSLP,IL-25,and IL-33),have emerged as critical mediators of type 2 inflammation.IL-33 attracts more interest for its strong association with allergic asthma,espe...Epithelial-derived cytokines,especially type 2 alarmins(TSLP,IL-25,and IL-33),have emerged as critical mediators of type 2 inflammation.IL-33 attracts more interest for its strong association with allergic asthma,especially in childhood asthma.However,the age-dependent role of IL-33 to the development of allergic asthma remains elusive.Here,using OVA-induced allergic asthma model in neonatal and adult mice,we report that IL-33 is the most important alarmin in neonatal lung both at steady state or inflammation.The deficiency of IL-33/ST2 abrogated the development of allergic asthma only in neonates,whereas in adults the effect was limited.Interestingly,the deficiency of IL-33/ST2 equally dampened the ILC2 responses in both neonatal and adult models.However,the effect of IL-33/ST2 deficiency on Th2 responses is age-dependent,which is only blocked in neonates.Furthermore,IL-33/ST2 signaling is dispensable for OVA sensitization.Following OVA challenge in adults,the deficiency of IL-33/ST2 results in compensational more TSLP,which in turn recruits and activates lung DCs and boosts Th2 responses.The enrichedγδT17 cells in IL-33/ST2 deficient neonatal lung suppress the expression of type 2 alarmins,CCL20 and GM-CSF via IL-17A,thus might confer the inhibition of allergic asthma.Finally,on the basis of IL-33 deficiency,the additive protective effects of TSLP blocking is much more pronounced than IL-25 blocking in adults.Our studies demonstrate that the role of IL-33 for ILC2 and Th2 responses varies among ages in OVA models and indicate that the factor of age should be considered for intervention of asthma.展开更多
Multiple autoimmune diseases often exhibit a cyclic pattern of relapse and remission, with significant periods of loss of self-tolerance being interrupted by recurrent autoimmune events. In this article, we explore a ...Multiple autoimmune diseases often exhibit a cyclic pattern of relapse and remission, with significant periods of loss of self-tolerance being interrupted by recurrent autoimmune events. In this article, we explore a specific type of terminally differentiated regulatory T cell HLA−DR+TRegcells, and their application in existing autoimmune disease models. We also conduct an in-depth study on a multiple sclerosis model. This model incorporates a Holling-II type functional response mechanism. The focus of the study is to analyze whether the equilibrium points of the system have local asymptotic stability and determine the conditions for the existence of Hopf bifurcation. Furthermore, the direction of Hopf bifurcations and the stability of its periodic solutions can be analyzed through normal form theory and center manifold theorem.展开更多
Topological insulating states in 2-dimensional(2D)materials are ideal systems to study different types of quantized response signals due to their in gap metallic states.Very recently,the quantum spin Hall effect was d...Topological insulating states in 2-dimensional(2D)materials are ideal systems to study different types of quantized response signals due to their in gap metallic states.Very recently,the quantum spin Hall effect was discovered in monolayer TalrTe Via the observation of quantized longitudinal conductance that rarely exists in other 2D topological insulators.The nontrivial Z_(2)topological charges can exist at both charge neutrality point and the van Hove singularity point with correlation-effect-induced bandgap.On the basis of this model 2D material,we studied the switch of quantized signals between longitudinal conductance and transversal Hall conductance via tuning external magnetic field.In Z_(2)topological phase of monolayer TalrTe_(4),the zero Chern number can be understood as 1-1=O from the double band inversion from spinup and spin-down channels.After applying a magnetic field perpendicular to the plane,the Zeeman split changes the band order for one branch of the band inversion from spin-up and spin-down channels,along with a sign charge of the Berry phase.Then,the net Chern number of 1-1=0 is tuned to 1+1=2 or-1-1=-2 depending on the orientation of the magnetic field.The quantized signal not only provides another effective method for the verification of topological state in monolayer TalrTe_(4)but also offers a strategy for the utilization of the new quantum topological states based on switchable quantized responses.展开更多
Objective To investigate the relationship between the expression of Th1/Th2 type cytokines and the effect of interferon-α therapy. Methods Th1/Th2 type cytokines were assayed by enzyme-linked immunosorbent assay (E...Objective To investigate the relationship between the expression of Th1/Th2 type cytokines and the effect of interferon-α therapy. Methods Th1/Th2 type cytokines were assayed by enzyme-linked immunosorbent assay (ELISA) and reverse transcription polymerase chain reaction (RT-PCR) on 23 patients with chronic hepatitis B who were treated with interferon-α.Results Levels of IFN-γ in the supernatant of peripheral blood mononuclear cells (PBMC) cultures from the patients with hepatitis B were slightly lower than those of controls (P=0.07). However, the levels of IL-4 were higher than those of controls (P=0.01). Cytokines measurements during IFN-α treatment showed a trend to decreaseing levels of IL-4 at 4, 12, and 24 weeks. Levels of IFN-γ were slightly increased following IFN-α treatment (P=0.09). In patients with a complete response to IFN-α, the levels of IFN-γ were higher at 24 weeks following IFN-α treatment than that of pre-treatment (P=0.04), and the levels of IL-4 decreased markedly at 12 and 24 weeks (P=0.02, 0.03, respectively). mRNA expression positively correlated with the level of Th1/Th2 type cytokines in the supernatant. Conclusion The expression of Th2 type cytokines is predominant in patients with chronic hepatitis B. Interferon-α therapy can modulate the balance of Th1/Th2 type cytokines, and this is related to its clinical effect. Levels of Th1/Th2 type cytokines could be a predictor of clinical response during Interferon -α treatment.展开更多
基金supported by Hong Kong Health and Medical Research Fund (13121032, 14130822 and HKM-15-M01)Hong Kong Research Grants Council (HKU1/CRF/11G, C7011-15R and T11-707/15-R)
文摘Coronaviruses have been closely related with mankind for thousands of years. Communityacquired human coronaviruses have long been recognized to cause common cold. However,zoonotic coronaviruses are now becoming more a global concern with the discovery of highly pathogenic severe acute respiratory syndrome(SARS) and Middle East respiratory syndrome(MERS) coronaviruses causing severe respiratory diseases. Infections by these emerging human coronaviruses are characterized by less robust interferon production. Treatment of patients with recombinant interferon regimen promises beneficial outcomes, suggesting that compromised interferon expression might contribute at least partially to the severity of disease. The mechanisms by which coronaviruses evade host innate antiviral response are under intense investigations. This review focuses on the fierce arms race between host innate antiviral immunity and emerging human coronaviruses. Particularly, the host pathogen recognition receptors and the signal transduction pathways to mount an effective antiviral response against SARS and MERS coronavirus infection are discussed. On the other hand, the counter-measures evolved by SARS and MERS coronaviruses to circumvent host defense are also dissected. With a better understanding of the dynamic interaction between host and coronaviruses, it is hoped that insights on the pathogenesis of newly-identified highly pathogenic human coronaviruses and new strategies in antiviral development can be derived.
基金Supported by the National Natural Science Foundation of China (10701020)
文摘The main purpose of this paper is to study the persistence of the general multispecies competition predator-pray system with Holling Ⅲ type functional response. In this system, the competition among predator species and among prey species are simultaneously considered. By using the comparison theory and qualitative analysis, the sufficient conditions for uniform strong persistence are obtained.
文摘In this study, the impulsive predator-prey dynamic systems on time scales calculus are studied. When the system has periodic solution is investigated, and three different conditions have been found, which are necessary for the periodic solution of the predator-prey dynamic systems with Beddington-DeAngelis type functional response. For this study the main tools are time scales calculus and coincidence degree theory. Also the findings are beneficial for continuous case, discrete case and the unification of both these cases. Additionally, unification of continuous and discrete case is a good example for the modeling of the life cycle of insects.
基金Supported by the National Natural Science Foundation of China(Grant No.11761063).
文摘In this paper,we consider the positive steady state solutions of a predator-prey model with Holling type Ⅱfunctional response and cross-diffusion,where two cross-diffusion rates represent the tendency of prey to keep away from its predator and the tendency of the predator to chase its prey,respectively.Applying the fixed point index theory,some sufficient conditions for the existence of positive steady state solutions are established.Furthermore,the non-existence of positive steady state solutions is studied.
基金supported by grants from the National Natural Science Foundation of China(Grant No.82260940)the Yunnan Provincial(Traditional Chinese Medicine)Clinical Dermatology Center,12th Five-year Key Construction Discipline of State Administration of Traditional Chinese Medicine“Dai Pharmacy”+1 种基金Open Project of Yunnan Key Laboratory of Dai and Yi Medicines(No.30971101100)Key Laboratory of Chemistry in Ethnic Medicinal Resources,State Ethnic Affairs Commission&Ministry of Education,Yunnan Minzu University.
文摘Background:This study aimed to assess how acupoint catgut-embedding therapy influences Th2-type immune response and the infiltration of CD4^(+)and CD8^(+)cells in DNCB-induced atopic dermatitis in BALB/c mice.It also conducted an initial examination of the underlying molecular mechanisms.Methods:Seventy-two mice were randomly divided into four groups:normal control,DNCB-induced atopic dermatitis model(AD),AD with acupoint catgut-embedding treatment(ADA),and AD with sham-acupoint catgut-embedding treatment.After DNCB challenge to induce AD,the ADA group received acupoint catgut-embedding therapy treatment at Zusanli(ST 36)and Quchi(LI 11)acupoints every other week from day 8.Mice in the AD with sham-acupoint catgut-embedding treatment group underwent the same procedure as the ADA group but without catgut implantation.Severity was assessed using SCORAD on treatment days 1,10,and 20.On day 18,nine mice per group were euthanized,and the remaining on day 28.Histopathological changes were observed using hematoxylin-eosin and immunohistochemistry staining.TNF-α,IL-4,IL-6,and IL-13 levels were analyzed by ELISA,and GATA3 and STAT6 protein levels by western blot.Results:After 20 days of acupoint catgut-embedding therapy treatment,mice showed reduced dermatitis scores compared to DNCB-induced AD-like mice.Significant decreases occurred in serum IL-4,IL-6,IL-13,and TNF-αlevels.Skin analysis revealed marked reductions in CD4^(+)and CD8^(+)cell infiltration,as well as GATA3 and STAT6 protein levels.Conclusion:Acupoint catgut-embedding therapy may effectively alleviate atopic dermatitis by suppressing Th2 immune responses via the STAT6-GATA3 pathway and reducing CD4^(+)and CD8^(+)T cell infiltration in skin lesions.
文摘The effect of endosulfan, a hexachlorinated pesticide, on growth, inorganic nitrogenous nutrient uptake (NO3-, NO2- and NH4+), change in pigmentation and glycogen content on wild type and chemically mutagenised cells of Synechococcus cedrorum was investigated. The pattern of response to pesticide stress in wild and mutant type was the same. Growth reappeared in both after a period of initial lag in presence of endosulfan. The duration of lag increased with increasing doses of pesticide. Paradoxically, however, the rate of uptake of NO-3, NO-2 and NH+4 pigment and glycogen content progressively increased with increasing doses. The difference in the adaptation response between wild and mutant types was observed only in the concentration of pesticide that could be tolerated; with the mutant tolerating 2.5 fold more.
基金Supported by the NNSF of China( 10171044) the Foundation for University Key Teachers of the Ministry of Education of China .
文摘A class of Beddington-DeAngelis＇ type predator-prey dynamic system with prey and predator both having linear density restriction is considered. By using the qualitative methods of ODE, the existence and uniqueness of positive equilibrium and its global asymptotic stability are analyzed. The direct criterions for local stability of positive equilibrium and existence of limit cycle are also established when inference parameter of predator is small.
基金the Deanship of Scientific Research at King Khalid University for funding this work through the Big Research Group Project under grant number(R.G.P2/16/40).
文摘In this paper,a discrete Lotka-Volterra predator-prey model is proposed that considers mixed functional responses of Holling types I and III.The equilibrium points of the model are obtained,and their stability is tested.The dynamical behavior of this model is studied according to the change of the control parameters.We find that the complex dynamical behavior extends from a stable state to chaotic attractors.Finally,the analytical results are clarified by some numerical simulations.
文摘Consider a class of Ivlev＇s type predator-prey dynamic systems with prey and predator both having linear density restricts. By using the qualitative methods of ODE, the global stability of positive equilibrium and existence and uniqueness of non-small amplitude stable limit cycle are obtained. Especially under certain conditions, it shows that existence and uniqueness of non-small amplitude stable limit cycle is equivalent to the local un-stability of positive equilibrium and the local stability of positive equilibrium implies its global stability. That is to say, the global dynamic of the system is entirely determined by the local stability of the positive equilibrium.
基金This work was supported by grants from the National Key Research and Development Program of China(2016YFA0502201)awarded to Prof.Huazhang Anthe National Natural Science Foundation of China(Nos.U1801283,31870908)+3 种基金the Guangdong Provincial Science and Technology Program(No.2019B030301009)the SZU Top Ranking Project(No.86000000210)awarded to Prof.Weilin Chenthe National Natural Science Foundation of China(No.81771711)awarded to Prof.Wengang Songthe Guangdong Provincial Science and Technology Program(No.2019A1515110086)awarded to Xibao Zhao.We thank Jessica Kate Tamanini(Scientific Editor,Shenzhen University School of Medicine)for editing the manuscript.
文摘The polarization of macrophages to the M1 or M2 phenotype has a pivotal role in inflammation and host defense;however,the underlying molecular mechanism remains unclear.Here,we show that myocyte enhancer factor 2 C(MEF2C)is essential for regulating M1 macrophage polarization in response to infection and inflammation.Global gene expression analysis demonstrated that MEF2C deficiency in macrophages downregulated the expression of M1 phenotypic markers and upregulated the expression of M2 phenotypic markers.MEF2C significantly promoted the expression of interleukin-12 p35 subunit(Il12a)and interleukin-12 p40 subunit(Il12b).Myeloid-specific Mef2c-knockout mice showed reduced IL-12 production and impaired Th1 responses,which led to susceptibility to Listeria monocytogenes infection and protected against DSS-induced IBD in vivo.Mechanistically,we showed that MEF2C directly activated the transcription of Il12a and Il12b.These findings reveal a new function of MEF2C in macrophage polarization and Th1 responses and identify MEF2C as a potential target for therapeutic intervention in inflammatory and autoimmune diseases.
基金by the Division of Intramural Research of NIAID(US National Institutes of Health).
文摘The type 2 immune response is critical for host defense against large parasites such as helminths.On the other hand,dysregulation of the type 2 immune response may cause immunopathological conditions,including asthma,atopic dermatitis,rhinitis,and anaphylaxis.Thus,a balanced type 2 immune response must be achieved to mount effective protection against invading pathogens while avoiding immunopathology.The classical model of type 2 immunity mainly involves the differentiation of type 2 T helper(Th2)cells and the production of distinct type 2 cytokines,including interleukin-4(IL-4),IL-5,and IL-13.Group 2 innate lymphoid cells(ILC2s)were recently recognized as another important source of type 2 cytokines.Although eosinophils,mast cells,and basophils can also express type 2 cytokines and participate in type 2 immune responses to various degrees,the production of type 2 cytokines by the lymphoid lineages,Th2 cells,and ILC2s in particular is the central event during the type 2 immune response.In this review,we discuss recent advances in our understanding of how ILC2s and Th2 cells orchestrate type 2 immune responses through direct and indirect interactions.
基金supported by National Natural Science Foundation of China(No.31900112,21907065,31970130,and 31670831)supported by the National Key Research and Development Program of China Grant(No.2016YFA0500600).
文摘COVID-19 is caused by SARS-CoV-2.1 As of July 16th,2020,there were 13,579,581 diagnosed cases and 584,782 deaths attributed to COVID-19 reported globally(https://coronavirus.jhu.edu/map.html).
基金This work was supported by National Key Research and Development Program of China under Grant No.2022YFD2401001National Natural Science Foundation of China under Grant No.U1905204+2 种基金China Agriculture Research System of MOF and MARA under Grant No.CARS-47Fujian Science and Technology Department under Grant No.2021N5008Institute of Oceanology of Fuzhou(2021F02).
文摘In mammals,mitofusin 2(MFN2)is involved in mitochondrial fusion,and suppresses the virus-induced RIG-I-like receptor(RLR)signaling pathway.However,little is known about the function of MFN2 in non-mammalian species.In the present study,we cloned an MFN2 ortholog(LcMFN2)in large yellow croaker(Larimichthys crocea).Phylogenetic analysis showed that MFN2 emerged after the divergence of amphioxus and vertebrates.The protein sequences of MFN2 were well conserved from fsh to mammals.LcMFN2 was expressed in all the tissues/organs examined at diferent levels,and its expression was upregulated in response to poly(I:C)stimulation.Overexpression of LcMFN2 inhibited MAVS-induced type I interferon(IFN)promoter activation and antiviral gene expression.In contrast,knockdown of endogenous LcMFN2 enhanced poly(I:C)induced production of type I IFNs.Additionally,LcMFN2 enhanced K48-linked polyubiquitination of MAVS,promoting its degradation.Also,overexpression of LcMFN2 impaired the cellular antiviral response,as evidenced by the increased expression of viral genes and more severe cytopathic efects(CPE)in cells infected with spring viremia of carp virus(SVCV).These results indicated that LcMFN2 inhibited type I IFN response by degrading MAVS,suggesting its negative regulatory role in cellular antiviral response.Therefore,our study sheds a new light on the regulatory mechanisms of the cellular antiviral response in teleosts.
基金Natural Science Foundation of China(U20A2037,31972980,and 32272482)Talent Project of Zhejiang Province(2019R52033)+1 种基金Key Research and Development Program of Zhejiang Province(2019C02018)Innovation Research 2035 Pilot Plan of Southwest University(SWU-XDZD22002),China.
文摘Cytokinins(CKs)are one of the important classes of plant hormones essential for plant growth and devel-opment.TATA-box binding protein-associated factor 12b(TAF12b)is involved in CK signaling,but its molecular and biochemical mechanisms are not fully understood.In this study,TAF12b of Nicotiana ben-thamiana(NbTAF12b)was found to mediate the CK response by directly interacting with type B response regulators(B-RRs),positive regulators of CK signaling,and inhibiting their transcriptional activities.As a transcriptional co-factor,TAF12b specifically facilitated the proteasomal degradation of non-phosphorylated B-RRs by recruiting the KISS ME DEADLY family of F-box proteins.Such interactions between TAF12b and B-RRs also occur in other plant species.Genetic transformation experiments showed that overexpression of NbTAF12b attenuates the CK-hypersensitive phenotype conferred by NbRR1 over-expression.Taken together,these results suggest a conserved mechanism in which TAF12b negatively regulates CK responses by promoting 26S proteasome-mediated B-RR degradation in multiple plant spe-cies,providing novel insights into the regulatory network of CK signaling in plants.
基金National Natural Science Foundation of China(#10671069).
文摘The main purpose of this paper is to explore the existence of positive periodic solutions to impulsive predator-prey systems with type IV functional responses. Sufficient criteria are obtained for the existence of strictly positive periodic solutions. The approach is based on a continuation theorem in the coincidence degree theory as well as some prior estimates. This is also the first time that multiple positive periodic solutions are obtained using coincidence degree theory in impulsive ecological systems.
基金Project supported by the National Natural Science Foundation of China (No.10171010) the Key Project on Science and Technology of the Education Ministry of People's Republic of China (No. Key 01061).
文摘In this paper, we consider a nonautonomous multispecies competition-predator system with Holling＇s type Ⅲ functional response. The coexistence of the system, under some conditions, is obtained. Furthermore, using Lyapunov function, we show that the system has a strictly positive almost periodic solution which is globally asymptotically stable.
基金support by the Laboratory Animal Center,Huazhong University of Science and Technologysupported in part by grants from the National Natural Science Foundation of China(grant 31970865)to J.H.by the Postdoctoral Fellowship Program of CPSF under Grant Number GZC20241497 to M.W.
文摘Epithelial-derived cytokines,especially type 2 alarmins(TSLP,IL-25,and IL-33),have emerged as critical mediators of type 2 inflammation.IL-33 attracts more interest for its strong association with allergic asthma,especially in childhood asthma.However,the age-dependent role of IL-33 to the development of allergic asthma remains elusive.Here,using OVA-induced allergic asthma model in neonatal and adult mice,we report that IL-33 is the most important alarmin in neonatal lung both at steady state or inflammation.The deficiency of IL-33/ST2 abrogated the development of allergic asthma only in neonates,whereas in adults the effect was limited.Interestingly,the deficiency of IL-33/ST2 equally dampened the ILC2 responses in both neonatal and adult models.However,the effect of IL-33/ST2 deficiency on Th2 responses is age-dependent,which is only blocked in neonates.Furthermore,IL-33/ST2 signaling is dispensable for OVA sensitization.Following OVA challenge in adults,the deficiency of IL-33/ST2 results in compensational more TSLP,which in turn recruits and activates lung DCs and boosts Th2 responses.The enrichedγδT17 cells in IL-33/ST2 deficient neonatal lung suppress the expression of type 2 alarmins,CCL20 and GM-CSF via IL-17A,thus might confer the inhibition of allergic asthma.Finally,on the basis of IL-33 deficiency,the additive protective effects of TSLP blocking is much more pronounced than IL-25 blocking in adults.Our studies demonstrate that the role of IL-33 for ILC2 and Th2 responses varies among ages in OVA models and indicate that the factor of age should be considered for intervention of asthma.
文摘Multiple autoimmune diseases often exhibit a cyclic pattern of relapse and remission, with significant periods of loss of self-tolerance being interrupted by recurrent autoimmune events. In this article, we explore a specific type of terminally differentiated regulatory T cell HLA−DR+TRegcells, and their application in existing autoimmune disease models. We also conduct an in-depth study on a multiple sclerosis model. This model incorporates a Holling-II type functional response mechanism. The focus of the study is to analyze whether the equilibrium points of the system have local asymptotic stability and determine the conditions for the existence of Hopf bifurcation. Furthermore, the direction of Hopf bifurcations and the stability of its periodic solutions can be analyzed through normal form theory and center manifold theorem.
基金supported by the Foundation from Liaoning Province(grant no.XLYC2203080)the National Natural Science Foundation of China(grant nos.52271016 and 52188101)the National Key R&D Program of China(grant no.2021YFB3501503)。
文摘Topological insulating states in 2-dimensional(2D)materials are ideal systems to study different types of quantized response signals due to their in gap metallic states.Very recently,the quantum spin Hall effect was discovered in monolayer TalrTe Via the observation of quantized longitudinal conductance that rarely exists in other 2D topological insulators.The nontrivial Z_(2)topological charges can exist at both charge neutrality point and the van Hove singularity point with correlation-effect-induced bandgap.On the basis of this model 2D material,we studied the switch of quantized signals between longitudinal conductance and transversal Hall conductance via tuning external magnetic field.In Z_(2)topological phase of monolayer TalrTe_(4),the zero Chern number can be understood as 1-1=O from the double band inversion from spinup and spin-down channels.After applying a magnetic field perpendicular to the plane,the Zeeman split changes the band order for one branch of the band inversion from spin-up and spin-down channels,along with a sign charge of the Berry phase.Then,the net Chern number of 1-1=0 is tuned to 1+1=2 or-1-1=-2 depending on the orientation of the magnetic field.The quantized signal not only provides another effective method for the verification of topological state in monolayer TalrTe_(4)but also offers a strategy for the utilization of the new quantum topological states based on switchable quantized responses.
文摘Objective To investigate the relationship between the expression of Th1/Th2 type cytokines and the effect of interferon-α therapy. Methods Th1/Th2 type cytokines were assayed by enzyme-linked immunosorbent assay (ELISA) and reverse transcription polymerase chain reaction (RT-PCR) on 23 patients with chronic hepatitis B who were treated with interferon-α.Results Levels of IFN-γ in the supernatant of peripheral blood mononuclear cells (PBMC) cultures from the patients with hepatitis B were slightly lower than those of controls (P=0.07). However, the levels of IL-4 were higher than those of controls (P=0.01). Cytokines measurements during IFN-α treatment showed a trend to decreaseing levels of IL-4 at 4, 12, and 24 weeks. Levels of IFN-γ were slightly increased following IFN-α treatment (P=0.09). In patients with a complete response to IFN-α, the levels of IFN-γ were higher at 24 weeks following IFN-α treatment than that of pre-treatment (P=0.04), and the levels of IL-4 decreased markedly at 12 and 24 weeks (P=0.02, 0.03, respectively). mRNA expression positively correlated with the level of Th1/Th2 type cytokines in the supernatant. Conclusion The expression of Th2 type cytokines is predominant in patients with chronic hepatitis B. Interferon-α therapy can modulate the balance of Th1/Th2 type cytokines, and this is related to its clinical effect. Levels of Th1/Th2 type cytokines could be a predictor of clinical response during Interferon -α treatment.
