Objective It is known that free radicals are involved in neurodegeneration and cognitive dysfunction, as seen in Alzheimer's disease (AD) and aging. The present study examines the protective effects of aniracetam a...Objective It is known that free radicals are involved in neurodegeneration and cognitive dysfunction, as seen in Alzheimer's disease (AD) and aging. The present study examines the protective effects of aniracetam against H2O2- induced toxicity to neuron viability, mitochondria potential and hippocampal long-term potentiation (LTP). Methods Tetrazolium salt 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide (MTT) was used to detect neuronal viability. MitoTracker Red (CMX Ros), a fluorescent stain for mitochondria, was used to measure mitochondria potential. Electrophysiological technique was carried out to record hippocampual LTE Results H2O2 exposure impaired the viability of neurons, reduced mitochondria potential, and decreased LTP in the CA region of hippocampus. These deficient effects were significantly rescued by pre-treatment with aniracetam (10 ~100μmol/L). Conclusion These results indicate that aniracetam has a strong neuroprotective effect against H2O2-induced toxicity, which could partly explain the mechanism of its clinical application in neurodegenerative diseases.展开更多
In this paper,the recurrent neural network structure of a bidirectional long shortterm memory network(Bi-LSTM)with special memory cells that store information is used to characterize the deep features of the variation...In this paper,the recurrent neural network structure of a bidirectional long shortterm memory network(Bi-LSTM)with special memory cells that store information is used to characterize the deep features of the variation pattern between logging and seismic data.A mapping relationship model between high-frequency logging data and low-frequency seismic data is established via nonlinear mapping.The seismic waveform is infinitely approximated using the logging curve in the low-frequency band to obtain a nonlinear mapping model of this scale,which then stepwise approach the logging curve in the high-frequency band.Finally,a seismic-inversion method of nonlinear mapping multilevel well–seismic matching based on the Bi-LSTM network is developed.The characteristic of this method is that by applying the multilevel well–seismic matching process,the seismic data are stepwise matched to the scale range that is consistent with the logging curve.Further,the matching operator at each level can be stably obtained to effectively overcome the problems that occur in the well–seismic matching process,such as the inconsistency in the scale of two types of data,accuracy in extracting the seismic wavelet of the well-side seismic traces,and multiplicity of solutions.Model test and practical application demonstrate that this method improves the vertical resolution of inversion results,and at the same time,the boundary and the lateral characteristics of the sand body are well maintained to improve the accuracy of thin-layer sand body prediction and achieve an improved practical application effect.展开更多
A wavelength splitter with ultra-compact and simple structure is proposed and analyzed by using both plane wave expansion (PWE) method and finite difference time domain (FDTD) method. The device is based on direct...A wavelength splitter with ultra-compact and simple structure is proposed and analyzed by using both plane wave expansion (PWE) method and finite difference time domain (FDTD) method. The device is based on directional coupling between two parallel lithium niobate (LiNbO3, LN) nanowire optical waveguides. The wavelength splitter with a coupling region length of 5 um can separate 1.3 um and 1.55 um wavelengths for corresponding outputs with transmittance higher than 97%.展开更多
We analyze an h-p version Petrov-Galerkin finite element method for linear Volterra integrodifferential equations. We prove optimal a priori error bounds in the L2- and H1-norm that are explicit in the time steps,the ...We analyze an h-p version Petrov-Galerkin finite element method for linear Volterra integrodifferential equations. We prove optimal a priori error bounds in the L2- and H1-norm that are explicit in the time steps,the approximation orders and in the regularity of the exact solution. Numerical experiments confirm the theoretical results. Moreover,we observe that the numerical scheme superconverges at the nodal points of the time partition.展开更多
We present several numerical methods and establish their error estimates for the discretization of the nonlinear Dirac equation (NLDE) in the nonrelativistic limit regime, involving a small dimensionless parameter 0...We present several numerical methods and establish their error estimates for the discretization of the nonlinear Dirac equation (NLDE) in the nonrelativistic limit regime, involving a small dimensionless parameter 0 〈 ε〈〈1 which is inversely proportional to the speed of light. In this limit regime, the solution is highly oscillatory in time, i.e., there are propagating waves with wavelength O( ε^2) and O(1) in time and space, respectively. We begin with the conservative Crank-Nicolson finite difference (CNFD) method and establish rigorously its error estimate which depends explicitly on the mesh size h and time step τ- as well as the small parameter 0 〈 ε≤1 Based on the error bound, in order to obtain 'correct' numerical solutions in the nonrelativistic limit regime, i.e., 0 〈 ε≤1 , the CNFD method requests the ε-scalability: τ- = O(ε3) and h = O(√ε). Then we propose and analyze two numerical methods for the discretization of NLDE by using the Fourier spectral discretization for spatial derivatives combined with the exponential wave integrator and time- splitting technique for temporal derivatives, respectively. Rigorous error bounds for the two numerical methods show that their ε-scalability is improved to τ = O(ε2) and h = O(1) when 0 〈 ε 〈〈 1. Extensive numerical results are reported to confirm our error estimates.展开更多
We aimed to investigate the impact of X-rays on miR-130a and miR-25 expressions of A549 cell lines and to understand the mechanism of miR-130a and miR-25 on the regulation of invasion and metastasis of A549 cell lines...We aimed to investigate the impact of X-rays on miR-130a and miR-25 expressions of A549 cell lines and to understand the mechanism of miR-130a and miR-25 on the regulation of invasion and metastasis of A549 cell lines. Human adenocarcinoma cells of the line A549 were cultured and radiated by X-rays at the absorbed doses of 2 and 4, respectively by linear accelerator. Transwell invasion and migration assay were employed to exam the metastasis ability of A549 cells post X-rays irradiation. Both the miRNA and mRNA were extracted from A549 cells at different time points post radiation. The expressions of miR-130a and miR-25, as well as the expressions of VEGF and CCR-7 mRNAs, were detected in A549 cells with 2 and 4 Gy X-rays radiation, respectively by real time PCR. Results were statistically analyzed by SAS 8.2 software, which showed that the invasiveness of A549 cells post 2 and 4 Gy X-rays increased significantly compared with that of untreated A549 cells (the migration cell numbers are 20, 48 and 62 in Group 0, 2 and 4 Gy X-rays, respectively). Furthermore, the expressions of miR-130a and miR-25 also increased significantly at the time-points of 1, 2, 4, and 8 h post radiation, and began to decrease to the control level at 12 h post radiation. VEGF and CCR-7 mRNAs were detected to be up-regulated 18 h post radiation and remained at a high level till 72 h post radiation. The expression of VEGF mRNA has a close correlation with that of CCR-7 mRNA, and the expression of miR-130a also has a correlation with that of VEGF and CCR-7mRNAs. It is concluded that the metastasis of A549 cells in vitro could be promoted by X-rays, and miR-130a might play a role in the metastasis of A549 cells via regulating the expressions of VEGF and CCR-7 mRNAs.展开更多
文摘Objective It is known that free radicals are involved in neurodegeneration and cognitive dysfunction, as seen in Alzheimer's disease (AD) and aging. The present study examines the protective effects of aniracetam against H2O2- induced toxicity to neuron viability, mitochondria potential and hippocampal long-term potentiation (LTP). Methods Tetrazolium salt 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide (MTT) was used to detect neuronal viability. MitoTracker Red (CMX Ros), a fluorescent stain for mitochondria, was used to measure mitochondria potential. Electrophysiological technique was carried out to record hippocampual LTE Results H2O2 exposure impaired the viability of neurons, reduced mitochondria potential, and decreased LTP in the CA region of hippocampus. These deficient effects were significantly rescued by pre-treatment with aniracetam (10 ~100μmol/L). Conclusion These results indicate that aniracetam has a strong neuroprotective effect against H2O2-induced toxicity, which could partly explain the mechanism of its clinical application in neurodegenerative diseases.
基金supported by the National Major Science and Technology Special Project(No.2016ZX05026-002).
文摘In this paper,the recurrent neural network structure of a bidirectional long shortterm memory network(Bi-LSTM)with special memory cells that store information is used to characterize the deep features of the variation pattern between logging and seismic data.A mapping relationship model between high-frequency logging data and low-frequency seismic data is established via nonlinear mapping.The seismic waveform is infinitely approximated using the logging curve in the low-frequency band to obtain a nonlinear mapping model of this scale,which then stepwise approach the logging curve in the high-frequency band.Finally,a seismic-inversion method of nonlinear mapping multilevel well–seismic matching based on the Bi-LSTM network is developed.The characteristic of this method is that by applying the multilevel well–seismic matching process,the seismic data are stepwise matched to the scale range that is consistent with the logging curve.Further,the matching operator at each level can be stably obtained to effectively overcome the problems that occur in the well–seismic matching process,such as the inconsistency in the scale of two types of data,accuracy in extracting the seismic wavelet of the well-side seismic traces,and multiplicity of solutions.Model test and practical application demonstrate that this method improves the vertical resolution of inversion results,and at the same time,the boundary and the lateral characteristics of the sand body are well maintained to improve the accuracy of thin-layer sand body prediction and achieve an improved practical application effect.
基金supported by the National Natural Science Foundation of China(No.61040064)
文摘A wavelength splitter with ultra-compact and simple structure is proposed and analyzed by using both plane wave expansion (PWE) method and finite difference time domain (FDTD) method. The device is based on directional coupling between two parallel lithium niobate (LiNbO3, LN) nanowire optical waveguides. The wavelength splitter with a coupling region length of 5 um can separate 1.3 um and 1.55 um wavelengths for corresponding outputs with transmittance higher than 97%.
基金supported by National Natural Science Foundation of China(Grant Nos.11226330 and 11301343)the Research Fund for the Doctoral Program of Higher Education of China(Grant No.20113127120002)+3 种基金the Research Fund for Young Teachers Program in Shanghai(GrantNo.shsf018)the Fund for E-institute of Shanghai Universities(Grant No.E03004)supported by the Natural Sciences and Engineering Research Council of Canada(Grant No.OGP0046726)Shanghai University under Leading Academic Discipline Project of Shanghai MunicipalEducation Commission(Grant No.J50101)
文摘We analyze an h-p version Petrov-Galerkin finite element method for linear Volterra integrodifferential equations. We prove optimal a priori error bounds in the L2- and H1-norm that are explicit in the time steps,the approximation orders and in the regularity of the exact solution. Numerical experiments confirm the theoretical results. Moreover,we observe that the numerical scheme superconverges at the nodal points of the time partition.
基金supported by the Ministry of Education of Singapore(Grant No.R146-000-196-112)National Natural Science Foundation of China(Grant No.91430103)
文摘We present several numerical methods and establish their error estimates for the discretization of the nonlinear Dirac equation (NLDE) in the nonrelativistic limit regime, involving a small dimensionless parameter 0 〈 ε〈〈1 which is inversely proportional to the speed of light. In this limit regime, the solution is highly oscillatory in time, i.e., there are propagating waves with wavelength O( ε^2) and O(1) in time and space, respectively. We begin with the conservative Crank-Nicolson finite difference (CNFD) method and establish rigorously its error estimate which depends explicitly on the mesh size h and time step τ- as well as the small parameter 0 〈 ε≤1 Based on the error bound, in order to obtain 'correct' numerical solutions in the nonrelativistic limit regime, i.e., 0 〈 ε≤1 , the CNFD method requests the ε-scalability: τ- = O(ε3) and h = O(√ε). Then we propose and analyze two numerical methods for the discretization of NLDE by using the Fourier spectral discretization for spatial derivatives combined with the exponential wave integrator and time- splitting technique for temporal derivatives, respectively. Rigorous error bounds for the two numerical methods show that their ε-scalability is improved to τ = O(ε2) and h = O(1) when 0 〈 ε 〈〈 1. Extensive numerical results are reported to confirm our error estimates.
基金supported by the National Natural Science Foundation of China (Grant No. 8117230)
文摘We aimed to investigate the impact of X-rays on miR-130a and miR-25 expressions of A549 cell lines and to understand the mechanism of miR-130a and miR-25 on the regulation of invasion and metastasis of A549 cell lines. Human adenocarcinoma cells of the line A549 were cultured and radiated by X-rays at the absorbed doses of 2 and 4, respectively by linear accelerator. Transwell invasion and migration assay were employed to exam the metastasis ability of A549 cells post X-rays irradiation. Both the miRNA and mRNA were extracted from A549 cells at different time points post radiation. The expressions of miR-130a and miR-25, as well as the expressions of VEGF and CCR-7 mRNAs, were detected in A549 cells with 2 and 4 Gy X-rays radiation, respectively by real time PCR. Results were statistically analyzed by SAS 8.2 software, which showed that the invasiveness of A549 cells post 2 and 4 Gy X-rays increased significantly compared with that of untreated A549 cells (the migration cell numbers are 20, 48 and 62 in Group 0, 2 and 4 Gy X-rays, respectively). Furthermore, the expressions of miR-130a and miR-25 also increased significantly at the time-points of 1, 2, 4, and 8 h post radiation, and began to decrease to the control level at 12 h post radiation. VEGF and CCR-7 mRNAs were detected to be up-regulated 18 h post radiation and remained at a high level till 72 h post radiation. The expression of VEGF mRNA has a close correlation with that of CCR-7 mRNA, and the expression of miR-130a also has a correlation with that of VEGF and CCR-7mRNAs. It is concluded that the metastasis of A549 cells in vitro could be promoted by X-rays, and miR-130a might play a role in the metastasis of A549 cells via regulating the expressions of VEGF and CCR-7 mRNAs.