In this paper, we construct an SIR epidemic model with a modified Beddington–DeAngelis type incidence rate and saturated treatment rate. We modify the incidence rateto incorporate the isolation of infected individual...In this paper, we construct an SIR epidemic model with a modified Beddington–DeAngelis type incidence rate and saturated treatment rate. We modify the incidence rateto incorporate the isolation of infected individuals after detection, and separation of somesusceptible individuals from the rest to avoid the infection, without an increase in thenumber of classes. We find that the system has a unique disease-free equilibrium (DFE)which is locally asymptotically stable when the reproduction number is less than unity.The multiple endemic equilibria may exist irrespective of the basic reproduction number.The existence of bistability is encountered. Supercritical transcritical (forward), as wellas subcritical transcritical (backward) bifurcation, may occur at R0 = 1 where contactrate, β = β∗ acts as the bifurcation parameter. Therefore, DFE need not be globallystable. The conditions for the existence of Andronov–Hopf bifurcation are deduced withmaximum treatment capacity, c = c0 as the bifurcation parameter. The impacts of isolation of confirmed infected cases and separation of some susceptible from rest are studiednumerically as well as the effect of saturation in treatment. The existence of chaoticbehavior is deduced by showing the maximum Lyapunov exponent to be positive as wellas the sensitivity to initial conditions. The computation of the Kalpan–Yorke dimensionto be fractional confirms the existence of fractal-type strange attractor. The positiveKolmogorov–Sinai entropy further strengthens the claim of the existence of chaos.展开更多
Objective： To investigate the effect of Ermiao Recipe （二妙方, EMR） with medicinal guide Angelicae Pubescentis Radix （APR） on the homing of bone marrow stem cells （BMSCs） to focal zone in osteoarthritis （OA） ...Objective： To investigate the effect of Ermiao Recipe （二妙方, EMR） with medicinal guide Angelicae Pubescentis Radix （APR） on the homing of bone marrow stem cells （BMSCs） to focal zone in osteoarthritis （OA） rats. Methods： Forty-eight Sprague-Dawley rats were randomly assigned to the sham-operated, model, EMR, and EMR plus APR groups （12 rats in each group）. The OA rat model was induced by anterior cruciate ligament transection and medial meniscus resection. All rats were injected with recombinant human granulocyta colony- stimulating factor [rhG-CSF, 30 μg/（kg.d） for continuous 7 days], and rats in the EMR and EMR plus APR groups were treated with EMR or EMR plus APR at 1.6 or 1.9 g/（kg.d） for 3 or 6 weeks, respectively. Cartilage histopathologic changes were observed by hematoxylin and eosin staining. Chondrocytes apoptosis and cartilage matrix components were tested by transferase-mediated deoxyuridine triphosphate-biotin nick end labeling assay and special staining. Interleukin-1β （IL-1 β）, tumor necrosis factor α （TNF-α）, bone morphogenetic protein 2 （BMP-2）, and transforming growth factor beta-1 （TGF-β1） in serum were detected by enzyme-linked immunosorbent assay or radioimmunoassay assay. Matrix metalloproteinase （MMP）-13, tissue inhibitors of metalloproteinase （TIMP）-1, bromodeoxyuridine （BrdU）, cluster of differentiation 34 （CD34）, and stromal cell derived factor 1 （SDF-1） were measured by immunohistochemistry assay. Results： EMR and EMR plus APR significantly inhibited articular cartilage damage and synovium inflammation in OA rats at 3 or 6 weeks of treatment, the most obvious changes in these parameters were found in the EMR plus APR group. At 6 weeks, compared with EMR treatment, EMR plus APR remarkably inhibited chondrocytes apoptosis and the release of IL-1β and TNF- a, obviously decreased MMP-13 expression, and significantly increased expressions of proteoglycan, collagen, type 11 collagen and TIMP-1, serum levels of BMP-2 and TGF- 131 as well as expressions of BrdU, CD34 and SDF-1 in cartilage articular （P〈0.01 or P〈0.05 ）. Conclusion： The medicinal guide APR improved the therapeutic effects of EMR on OA rats by promoting directional homing of BMSCs to focal zone.展开更多
Pathological cardiac hypertrophy is an early and significant cardiac structural characteristic that contributes to the onset and progression of heart failure(HF).Its mainly structural feature is the abnormally enlarge...Pathological cardiac hypertrophy is an early and significant cardiac structural characteristic that contributes to the onset and progression of heart failure(HF).Its mainly structural feature is the abnormally enlarged cardiomyocyte.Effective intervention targets for abnormally enlarged cardiomyocyte remain to be identified.Previous studies have shown that the cellular shape and size can be regulated by the actin related protein 2/3(Arp2/3)complex,which is an actin-binding protein complex involved in the actin nucleation and assembly.However,the roles of the Arp2/3 complex in cardiomyocyte hypertrophy remain unknown.Here our study identifies its novel roles in the occurrence and development of cardiomyocyte hypertrophy.We found that mRNA levels of all subunits from the Arp2/3 complex are significantly upregulated(P<0.05)in the angiotensin Ⅱ(Ang Ⅱ)-induced neonatal rat primary and H9c2 cardiomyocyte hypertrophy.Further studies showed that siRNA-directed ARPC 2 silencing inhibits the reactivation of fetal genes and enlargement of cardiomyocyte area induced by Ang Ⅱ in neonatal rat primary cardiomyocytes(NRCMs)and H9c2 cells(P<0.05).In addition,the upstream activators of the Arp2/3 complex including SH3 protein interacting with Nck,90 kD(SPIN90)and Ras-related C3 botulinum toxin substrate 1(Rac1)/WASp family Verprolin-homologous protein-2(WAVE-2)are upregulated(P<0.05)in Ang Ⅱ-induced neonatal rat primary and H9c2 cardiomyocyte hypertrophy,indicating the excessive activation of the Arp2/3 complex.We further show that CK666,a specific Arp2/3 complex inhibitor,prevents the reactivation of fetal genes and the enlargement of cardiomyocyte area induced by Ang Ⅱ in NRCMs and H9c2 cells(P<0.05).Our results reveal that the Arp2/3 complex plays a crucial role in Ang Ⅱ-induced cardiomyocyte hypertrophy,which is beneficial to further studies about the molecular mechanisms by which the Arp2/3 complex regulates pathological cardiac hypertrophy.展开更多
"Kelsang Yanglha,from Xiasima Town,Yadong County,Xigaze City,Xizang."That's how Kelsang Yanglha usually introduce herself.While most people might mention only the province or city where they were born,Ke..."Kelsang Yanglha,from Xiasima Town,Yadong County,Xigaze City,Xizang."That's how Kelsang Yanglha usually introduce herself.While most people might mention only the province or city where they were born,Kelsang would always make the introduction more specific,telling others the full name of her hometown.For her,identity is more than just a provincial or city-level label-it extends down to the small town with three streets where her life story started.展开更多
文摘In this paper, we construct an SIR epidemic model with a modified Beddington–DeAngelis type incidence rate and saturated treatment rate. We modify the incidence rateto incorporate the isolation of infected individuals after detection, and separation of somesusceptible individuals from the rest to avoid the infection, without an increase in thenumber of classes. We find that the system has a unique disease-free equilibrium (DFE)which is locally asymptotically stable when the reproduction number is less than unity.The multiple endemic equilibria may exist irrespective of the basic reproduction number.The existence of bistability is encountered. Supercritical transcritical (forward), as wellas subcritical transcritical (backward) bifurcation, may occur at R0 = 1 where contactrate, β = β∗ acts as the bifurcation parameter. Therefore, DFE need not be globallystable. The conditions for the existence of Andronov–Hopf bifurcation are deduced withmaximum treatment capacity, c = c0 as the bifurcation parameter. The impacts of isolation of confirmed infected cases and separation of some susceptible from rest are studiednumerically as well as the effect of saturation in treatment. The existence of chaoticbehavior is deduced by showing the maximum Lyapunov exponent to be positive as wellas the sensitivity to initial conditions. The computation of the Kalpan–Yorke dimensionto be fractional confirms the existence of fractal-type strange attractor. The positiveKolmogorov–Sinai entropy further strengthens the claim of the existence of chaos.
基金Supported by National Natural Science Foundation of China(No.81072900)
文摘Objective： To investigate the effect of Ermiao Recipe （二妙方, EMR） with medicinal guide Angelicae Pubescentis Radix （APR） on the homing of bone marrow stem cells （BMSCs） to focal zone in osteoarthritis （OA） rats. Methods： Forty-eight Sprague-Dawley rats were randomly assigned to the sham-operated, model, EMR, and EMR plus APR groups （12 rats in each group）. The OA rat model was induced by anterior cruciate ligament transection and medial meniscus resection. All rats were injected with recombinant human granulocyta colony- stimulating factor [rhG-CSF, 30 μg/（kg.d） for continuous 7 days], and rats in the EMR and EMR plus APR groups were treated with EMR or EMR plus APR at 1.6 or 1.9 g/（kg.d） for 3 or 6 weeks, respectively. Cartilage histopathologic changes were observed by hematoxylin and eosin staining. Chondrocytes apoptosis and cartilage matrix components were tested by transferase-mediated deoxyuridine triphosphate-biotin nick end labeling assay and special staining. Interleukin-1β （IL-1 β）, tumor necrosis factor α （TNF-α）, bone morphogenetic protein 2 （BMP-2）, and transforming growth factor beta-1 （TGF-β1） in serum were detected by enzyme-linked immunosorbent assay or radioimmunoassay assay. Matrix metalloproteinase （MMP）-13, tissue inhibitors of metalloproteinase （TIMP）-1, bromodeoxyuridine （BrdU）, cluster of differentiation 34 （CD34）, and stromal cell derived factor 1 （SDF-1） were measured by immunohistochemistry assay. Results： EMR and EMR plus APR significantly inhibited articular cartilage damage and synovium inflammation in OA rats at 3 or 6 weeks of treatment, the most obvious changes in these parameters were found in the EMR plus APR group. At 6 weeks, compared with EMR treatment, EMR plus APR remarkably inhibited chondrocytes apoptosis and the release of IL-1β and TNF- a, obviously decreased MMP-13 expression, and significantly increased expressions of proteoglycan, collagen, type 11 collagen and TIMP-1, serum levels of BMP-2 and TGF- 131 as well as expressions of BrdU, CD34 and SDF-1 in cartilage articular （P〈0.01 or P〈0.05 ）. Conclusion： The medicinal guide APR improved the therapeutic effects of EMR on OA rats by promoting directional homing of BMSCs to focal zone.
文摘Pathological cardiac hypertrophy is an early and significant cardiac structural characteristic that contributes to the onset and progression of heart failure(HF).Its mainly structural feature is the abnormally enlarged cardiomyocyte.Effective intervention targets for abnormally enlarged cardiomyocyte remain to be identified.Previous studies have shown that the cellular shape and size can be regulated by the actin related protein 2/3(Arp2/3)complex,which is an actin-binding protein complex involved in the actin nucleation and assembly.However,the roles of the Arp2/3 complex in cardiomyocyte hypertrophy remain unknown.Here our study identifies its novel roles in the occurrence and development of cardiomyocyte hypertrophy.We found that mRNA levels of all subunits from the Arp2/3 complex are significantly upregulated(P<0.05)in the angiotensin Ⅱ(Ang Ⅱ)-induced neonatal rat primary and H9c2 cardiomyocyte hypertrophy.Further studies showed that siRNA-directed ARPC 2 silencing inhibits the reactivation of fetal genes and enlargement of cardiomyocyte area induced by Ang Ⅱ in neonatal rat primary cardiomyocytes(NRCMs)and H9c2 cells(P<0.05).In addition,the upstream activators of the Arp2/3 complex including SH3 protein interacting with Nck,90 kD(SPIN90)and Ras-related C3 botulinum toxin substrate 1(Rac1)/WASp family Verprolin-homologous protein-2(WAVE-2)are upregulated(P<0.05)in Ang Ⅱ-induced neonatal rat primary and H9c2 cardiomyocyte hypertrophy,indicating the excessive activation of the Arp2/3 complex.We further show that CK666,a specific Arp2/3 complex inhibitor,prevents the reactivation of fetal genes and the enlargement of cardiomyocyte area induced by Ang Ⅱ in NRCMs and H9c2 cells(P<0.05).Our results reveal that the Arp2/3 complex plays a crucial role in Ang Ⅱ-induced cardiomyocyte hypertrophy,which is beneficial to further studies about the molecular mechanisms by which the Arp2/3 complex regulates pathological cardiac hypertrophy.
文摘"Kelsang Yanglha,from Xiasima Town,Yadong County,Xigaze City,Xizang."That's how Kelsang Yanglha usually introduce herself.While most people might mention only the province or city where they were born,Kelsang would always make the introduction more specific,telling others the full name of her hometown.For her,identity is more than just a provincial or city-level label-it extends down to the small town with three streets where her life story started.
