Based on the topological degree for 1-set-contractive fields established in [11], we discuss the 1-set-contractive perturbation and the existence of zero points for nonlinear equations with accretive mappings in Menge...Based on the topological degree for 1-set-contractive fields established in [11], we discuss the 1-set-contractive perturbation and the existence of zero points for nonlinear equations with accretive mappings in Menger PN-spaces and obtain some new results.展开更多
The EI Nino-southern oscillation （ENSO） is an interannual phenomenon involved in tropical Pacific ocean- atmosphere interactions. In this paper, we develop an asymptotic method of solving the nonlinear equation usin...The EI Nino-southern oscillation （ENSO） is an interannual phenomenon involved in tropical Pacific ocean- atmosphere interactions. In this paper, we develop an asymptotic method of solving the nonlinear equation using the ENSO model. Based on a class of the oscillator of the ENSO model, a approximate solution of the corresponding problem is studied employing the perturbation method.展开更多
Background: Routine lung function testing requires expensive equipment, or requires maximum expiratory effort. The airflow perturbation device (APD) is a light handheld device, allowing for serial measures of respirat...Background: Routine lung function testing requires expensive equipment, or requires maximum expiratory effort. The airflow perturbation device (APD) is a light handheld device, allowing for serial measures of respiratory resistance noninvasively and effortlessly. Methods: In a convenience sample of 398 patients undergoing pulmonary function testing, we compared routine spirometric indices (forced expired volume in 1 second (FEV1), peak expiratory flow (PEF)), and airways resistance (Raw-272 patients), to measures of respiratory resistance measured with the APD including inspiratory (IR), expiratory (ER) and averaged (AR) resistance. Results: Measures of lung function were significantly correlated (p 0.001). On regression analysis, between 7% - 17% of the variance (R2) for FEV1, PEF, and Raw was explained by APD measurements. Approximately 2/3 of the variance in FEV1 was explained by PEF measurements. Conclusions: APD measurements of lung function correlate with conventional measures. Future studies should be directed at exploring the use of the APD device in serial measures of lung function in patients with lung disease.展开更多
In this paper, the（2＋1）-dimensional perturbed Boussinesq equation is transformed into a series of two-dimensional（2 D） similarity reduction equations by using the approximate symmetry method. A step-by-step proce...In this paper, the（2＋1）-dimensional perturbed Boussinesq equation is transformed into a series of two-dimensional（2 D） similarity reduction equations by using the approximate symmetry method. A step-by-step procedure is used to acquire Jacobi elliptic function solutions to these similarity equations, which generate the truncated series solutions to the original perturbed Boussinesq equation. Aside from some singular area, the series solutions are convergent when the perturbation parameter is diminished.展开更多
The paper is concerned with strongly nonlinear singularly perturbed bound- ary value problems in one dimension.The problems are solved numerically by finite- difference schemes on special meshes which are dense in the...The paper is concerned with strongly nonlinear singularly perturbed bound- ary value problems in one dimension.The problems are solved numerically by finite- difference schemes on special meshes which are dense in the boundary layers.The Bakhvalov mesh and a special piecewise equidistant mesh are analyzed.For the central scheme,error estimates are derived in a discrete L^1 norm.They are of second order and decrease together with the perturbation parameterε.The fourth-order Numerov scheme and the Shishkin mesh are also tested numerically.Numerical results showε-uniform pointwise convergence on the Bakhvalov and Shishkin meshes.展开更多
The well-known insulin-like growth factor 1(IGF1)/IGF-1 receptor(IGF-1R)signaling pathway is overexpressed in many tumors,and is thus an attractive target for cancer treatment.However,results have often been disappoin...The well-known insulin-like growth factor 1(IGF1)/IGF-1 receptor(IGF-1R)signaling pathway is overexpressed in many tumors,and is thus an attractive target for cancer treatment.However,results have often been disappointing due to crosstalk with other signals.Here,we report that IGF-1R signaling stimulates the growth of hepatocellular carcinoma(HCC)cells through the translocation of IGF-1R into the ER to enhance sarco-endoplasmic reticulum calcium ATPase 2(SERCA2)activity.In response to ligand binding,IGF-1Rβis translocated into the ER byβ-arrestin2(β-arr2).Mass spectrometry analysis identified SERCA2 as a target of ER IGF-1Rβ.SERCA2 activity is heavily dependent on the increase in ER IGF-1Rβlevels.ER IGF-1Rβphosphorylates SERCA2 on Tyr^(990)to enhance its activity.Mutation of SERCA2-Tyr^(990)disrupted the interaction of ER IGF-1Rβwith SERCA2,and therefore ER IGF-1Rβfailed to promote SERCA2 activity.The enhancement of SERCA2 activity triggered Ca_(ER)^(2+)perturbation,leading to an increase in autophagy.Thapsigargin blocked the interaction between SERCA2and ER IGF-1Rβand therefore SERCA2 activity,resulting in inhibition of HCC growth.In conclusion,the translocation of IGF-1R into the ER triggers Ca_(ER)^(2+)perturbation by enhancing SERCA2 activity through phosphorylating Tyr^(990)in HCC.展开更多
A class of coupled system to oscillate of the E1 Nino/La Nino-Southern Oscillation （ENSO） mechanism is studied. Using the perturbed theory, the asymptotic expansions and asymptotic behavior of the solution for an EN...A class of coupled system to oscillate of the E1 Nino/La Nino-Southern Oscillation （ENSO） mechanism is studied. Using the perturbed theory, the asymptotic expansions and asymptotic behavior of the solution for an ENSO model are obtained.展开更多
基金Supported by the National Natural Science Foundation of China(11071108)the Natural Science Foundation of Jiangxi Province of China(2010GZS0147)
文摘Based on the topological degree for 1-set-contractive fields established in [11], we discuss the 1-set-contractive perturbation and the existence of zero points for nonlinear equations with accretive mappings in Menger PN-spaces and obtain some new results.
基金Project supported by the National Natural Science Foundation of China （Grant Nos. 11071205 and 11101349）, the “Strate- gic Priority Research Program-Climate Change： Carbon Budget and Relevant Issues” of the Chinese Academy of Sciences, China （Grant No. XDA01020304）, the Natural Science Foundation from the Education Bureau of Anhui Province, China （Grant No. KJ2011A135）, and the Natural Science Foundation of Jiangsu Province, China （Grant No. BK2011042）.
文摘The EI Nino-southern oscillation （ENSO） is an interannual phenomenon involved in tropical Pacific ocean- atmosphere interactions. In this paper, we develop an asymptotic method of solving the nonlinear equation using the ENSO model. Based on a class of the oscillator of the ENSO model, a approximate solution of the corresponding problem is studied employing the perturbation method.
文摘Background: Routine lung function testing requires expensive equipment, or requires maximum expiratory effort. The airflow perturbation device (APD) is a light handheld device, allowing for serial measures of respiratory resistance noninvasively and effortlessly. Methods: In a convenience sample of 398 patients undergoing pulmonary function testing, we compared routine spirometric indices (forced expired volume in 1 second (FEV1), peak expiratory flow (PEF)), and airways resistance (Raw-272 patients), to measures of respiratory resistance measured with the APD including inspiratory (IR), expiratory (ER) and averaged (AR) resistance. Results: Measures of lung function were significantly correlated (p 0.001). On regression analysis, between 7% - 17% of the variance (R2) for FEV1, PEF, and Raw was explained by APD measurements. Approximately 2/3 of the variance in FEV1 was explained by PEF measurements. Conclusions: APD measurements of lung function correlate with conventional measures. Future studies should be directed at exploring the use of the APD device in serial measures of lung function in patients with lung disease.
基金Project supported by the National Natural Science Foundation of China(Grant No.11505094)the Natural Science Foundation of Jiangsu Province,China(Grant No.BK20150984)
文摘In this paper, the（2＋1）-dimensional perturbed Boussinesq equation is transformed into a series of two-dimensional（2 D） similarity reduction equations by using the approximate symmetry method. A step-by-step procedure is used to acquire Jacobi elliptic function solutions to these similarity equations, which generate the truncated series solutions to the original perturbed Boussinesq equation. Aside from some singular area, the series solutions are convergent when the perturbation parameter is diminished.
文摘The paper is concerned with strongly nonlinear singularly perturbed bound- ary value problems in one dimension.The problems are solved numerically by finite- difference schemes on special meshes which are dense in the boundary layers.The Bakhvalov mesh and a special piecewise equidistant mesh are analyzed.For the central scheme,error estimates are derived in a discrete L^1 norm.They are of second order and decrease together with the perturbation parameterε.The fourth-order Numerov scheme and the Shishkin mesh are also tested numerically.Numerical results showε-uniform pointwise convergence on the Bakhvalov and Shishkin meshes.
基金supported by the National Natural Science Foundation of China(81973350,China)supported by the National Natural Science Foundation of China(81872884 and 82173841,China)Beijing Natural Science Foundation(7222253,China)。
文摘The well-known insulin-like growth factor 1(IGF1)/IGF-1 receptor(IGF-1R)signaling pathway is overexpressed in many tumors,and is thus an attractive target for cancer treatment.However,results have often been disappointing due to crosstalk with other signals.Here,we report that IGF-1R signaling stimulates the growth of hepatocellular carcinoma(HCC)cells through the translocation of IGF-1R into the ER to enhance sarco-endoplasmic reticulum calcium ATPase 2(SERCA2)activity.In response to ligand binding,IGF-1Rβis translocated into the ER byβ-arrestin2(β-arr2).Mass spectrometry analysis identified SERCA2 as a target of ER IGF-1Rβ.SERCA2 activity is heavily dependent on the increase in ER IGF-1Rβlevels.ER IGF-1Rβphosphorylates SERCA2 on Tyr^(990)to enhance its activity.Mutation of SERCA2-Tyr^(990)disrupted the interaction of ER IGF-1Rβwith SERCA2,and therefore ER IGF-1Rβfailed to promote SERCA2 activity.The enhancement of SERCA2 activity triggered Ca_(ER)^(2+)perturbation,leading to an increase in autophagy.Thapsigargin blocked the interaction between SERCA2and ER IGF-1Rβand therefore SERCA2 activity,resulting in inhibition of HCC growth.In conclusion,the translocation of IGF-1R into the ER triggers Ca_(ER)^(2+)perturbation by enhancing SERCA2 activity through phosphorylating Tyr^(990)in HCC.
文摘A class of coupled system to oscillate of the E1 Nino/La Nino-Southern Oscillation （ENSO） mechanism is studied. Using the perturbed theory, the asymptotic expansions and asymptotic behavior of the solution for an ENSO model are obtained.
