In order to enhance geological body boundary visual effects in images and improve interpretation accuracy using gravity and magnetic field data, we propose an improved small sub-domain filtering method to enhance grav...In order to enhance geological body boundary visual effects in images and improve interpretation accuracy using gravity and magnetic field data, we propose an improved small sub-domain filtering method to enhance gravity anomalies and gravity gradient tensors. We discuss the effect of Gaussian white noise on the improved small sub-domain filtering method, as well as analyze the effect of window size on geological body edge recognition at different extension directions. Model experiments show that the improved small sub-domain filtering method is less affected by noise, filter window size, and geological body edge direction so it can more accurately depict geological body edges than the conventional small sub-domain filtering method. It also shows that deeply buried body edges can be well delineated through increasing the filter window size. In application, the enhanced gravity anomalies and calculated gravity gradient tensors of the Hulin basin show that the improved small sub-domain filtering can recognize more horizontal fault locations than the conventional method.展开更多
[Objective] This study aimed to investigate the effects of temperature on determination of protein concentration with Coomassie Brilliant Blue method,thus proving advice and guidance for accurate determination of prot...[Objective] This study aimed to investigate the effects of temperature on determination of protein concentration with Coomassie Brilliant Blue method,thus proving advice and guidance for accurate determination of protein concentration.[Method] With Coomassie Brilliant Blue method,the concentrations of different bovine serum albumin samples were determined under different temperatures and incubation time.[Result] According to the standard curve,when the determination range of protein concentration was 0-100 mg/ml,the determined protein concentration was relatively stable after incubation at 20 ℃ for 20-30 min.Furthermore,the determination result of higher protein concentration with Coomassie Brilliant Blue method was less affected by various factors.[Conclusion] In determination of protein concentration with Coomassie Brilliant Blue method,temperature,sample concentration and incubation time were important factors affecting the accuracy of experimental results.展开更多
By the use of cross-correlation measures, the response of a symmetric Schmitt trigger (ST) driven by a random binary signal and white Gaussian noise is investigated. The results show that the information transmission...By the use of cross-correlation measures, the response of a symmetric Schmitt trigger (ST) driven by a random binary signal and white Gaussian noise is investigated. The results show that the information transmission can be enhanced when a certain amount of noise is presented, i.e., aperiodic stochastic resonance (ASR). Then, the influence of signal amplitude and the ST threshold on ASR is examined, the applicability of the ST in reducing the noise level of random signal transmission and improving the quality of output signal via ASR effect is illustrated. This research is of great interest in the field of digital communications.展开更多
Based on the anti-jamming performance of differential frequency hopping (DFH) systems in Additive White Gaussian Noise (AWGN) channel, Fountain code is introduced to the DFH systems as the outer error correcting c...Based on the anti-jamming performance of differential frequency hopping (DFH) systems in Additive White Gaussian Noise (AWGN) channel, Fountain code is introduced to the DFH systems as the outer error correcting code in this paper to investigate the improvements against partial-band jamming over AWGN channel. The performance of Fountain coded DFH is theoretically analyzed and numerically simulated. The total frequency of hopping in the simulation is 16, and results show that, on one hand, when exact jamming state information (JSI) is available, and the number of jamming frequency is n= 16, the bit error rate (BER) of 10~3 is achieved with the signal to interference ratio (SIR) approximately 7.5 dB over AWGN channel, and the performance improves about 1-1.5dB compared with the no-coded system. When the number of jamming frequency is n=2, the performance increases 15-17dB. On the other hand, when JSI is unavailable, a joint JSI estimation and decoding algorithm is proposed. The BER of 10 3 is achieved with jamming-frequency n 16, SIR=8dB and signal noise ratio (SNR) 10dB over AWGN channel. It's proved that this algorithm provides robust anti-jamming pertbrmance even without JSI. The anti-jamming performance of Fountain coded DFH systems is obviously superior to no-coded DFH systems.展开更多
The electromagnetic radiation (EMR) signal collected by monitoring system during coal or rock dynamic disaster may be interferred easily by electromagnetic noises in mines. The noises have a direct influence on the ...The electromagnetic radiation (EMR) signal collected by monitoring system during coal or rock dynamic disaster may be interferred easily by electromagnetic noises in mines. The noises have a direct influence on the recognition and analysis of the EMR signal features during the disaster. With the aim of removing these noises, an ensemble empirical mode decomposition (EEMD) adaptive morphological filter was proposed. From the result of the simulation and the experiment, it is shown that the method can restrain the random noise and white Gaussian noise mixed with EMR signal effectively. The filter is highly useful for improving the robustness of the coal or rock dynamic disaster monitoring system.展开更多
Constant envelope orthogonal frequency division multiplexing(CE-OFDM) is a waveform that can achieve 0d B peak-to-average power ratio and avoid the signal distortion caused by the nonlinear power amplifi er. However, ...Constant envelope orthogonal frequency division multiplexing(CE-OFDM) is a waveform that can achieve 0d B peak-to-average power ratio and avoid the signal distortion caused by the nonlinear power amplifi er. However, the carrier frequency offset(CFO) in CE-OFDM systems can cause errors at phase unwrapper module. In this paper, a CFO estimation scheme is proposed for CEOFDM in satellite communication system. As the null subcarrier is inherent in the conjugate symmetric symbol structure at the transmitter, the proposed scheme uses the null subcarrier as prior information to estimate the CFO at the receiver. The ideal estimation range of normalized CFO is obtained by mathematical analysis. Simulation results show that the proposed scheme can estimate the CFO accurately under additive white Gaussian noise(AWGN) channel and multipath fading channel, especially for moderate and high signal-to-noise ratio(SNR).展开更多
In this paper, a novel detection criterion is proposed to decide whether primary user(PU) exists based on joint analysis of the variance and correlation for observation signal,considering a correlation within the obse...In this paper, a novel detection criterion is proposed to decide whether primary user(PU) exists based on joint analysis of the variance and correlation for observation signal,considering a correlation within the observed signal. Simultaneously, the corresponding detection thresholds are also designed. Simulation experiments verify the proposed method suits for the observation signal in Additive White Gaussian Noise(AWGN), Rayleigh,Rician channel and the detection performance is improved greatly.展开更多
AIM: To investigate the interrelationship between Epstein-Barr virus (EBV)-encoded proteins and cell proliferation, apoptosis and apoptosis-related proteins in gastric carcinoma, and to explore their role in gastric c...AIM: To investigate the interrelationship between Epstein-Barr virus (EBV)-encoded proteins and cell proliferation, apoptosis and apoptosis-related proteins in gastric carcinoma, and to explore their role in gastric carcinogenesis. METHODS: Tissues from 13 cases of EBV-associated gastric carcinoma (EBVaGC) and 45 cases of matched EBV-negative gastric carcinoma (EBVnGC) were collected, and then subjected to analysis for apoptotic index (AI) using the terminal deoxynucleotidyl transferase (TdT)-mediated dUTP-biotin nick end-labeling (TUNEL) assay. Nuclear cell proliferation-associated antigen ki-67 index (KI), bcl-2, and p53 expression were examined by immunohistochemistry.p53 mutation in exons 5-8 of 13 EBVaGC cases was determined by single-strand conformation polymorphism (SSCP) and DNA sequencing.RT-PCR and Southern hybridization were used to detect the expression of nuclear antigens (EBNAs) 1 and 2, latent membrane protein (IMP) 1, immediately early gene BZLF1 and early genes BARF1 and BHRF1 in 13 EBVaGC cases. RESULTS: The percentage of AI, KI and p53 overexpression was significantly lower in the EBVaGC group than in the EBVnGC group. However, bcl-2 expression did not show significant difference between the two groups. p53 gene mutations were not found in 13 EBVaGCs. Transcripts of EBNA1 were detected in all 13 EBVaGCs, while both EBNA2 and LMP1 mRNA were not detected. Six of the thirteen cases exhibited BZLF1 transcripts and two exhibited BHRF1 transcripts. BARF1 mRNA was detected in six cases. CONCLUSION: Lower AI and KI may reflect a low biological activity in EBVaGC. EBV infection is associated with p53 abnormal expression but not bcl-2 protein in EBVaGC. BZLF1,BARF1,and BHRF1 may play important roles in inhibiting cell apoptosis and tumorigenesis of EBVaGC through different pathways.展开更多
AIM: To investigate the interrelationship of Epstein-Barr virus (EBV) and EBV- encoded proteins with Helicobacter pylori (H pylor/~ infection and the expression of c-met and c-myc oncogene proteins in gastric carc...AIM: To investigate the interrelationship of Epstein-Barr virus (EBV) and EBV- encoded proteins with Helicobacter pylori (H pylor/~ infection and the expression of c-met and c-myc oncogene proteins in gastric carcinoma, and to explore their role in gastric carcinogenesis. METHODS: One hundred and eighty-five gastric carcinoma tissues were detected by polymerase chain reaction (PCR)-Southern blot for EBV genome and in situ hybridization (ISH) for EBV-encoded small RNA 1 (EBER1). Gastric carcinoma with positive EBER1 signals was confirmed EBV-associated gastric carcinoma (EBVaGC). The status of Hpylori infection in 185 gastric carcinomas was assessed by rapid urease test and PCR. The samples with positive PCR and urease test were defined as H pylorl infection. The expression of c-met and c-myc oncogene proteins in tissues of EBVaGC and matched EBV-negative gastric carcinoma (EBVnGC) were examined by immunohistochemistry. RT-PCR and Southern hybridization were used to detect the expression of nuclear antigens (EBNAs) 1 and 2, latent membrane protein (LMP) 1, early genes BARF1 and BHRF1 in EBVaGC cases. RESULTS: The positive rate of H pylori and EBV in 185 gastric carcinomas was 59.45% (110/185) and 7.03% (13/185) respectively. No difference was found in sex, age, pathological differentiation, clinical stages and lymph node metastasis between H pylori-positive and H pylori-negative gastric carcinomas. However, the positive rate of H pylori infection in the antrum gastric carcinomas was higher than that of cardia and body gastric carcinomas. In our series, age, pathological differentiation, clinical stages, lymph node metastasis and location of cancer were not different between EBVnGC and EBVaGC, while the positive rate of EBV in male patients was significantly higher than that of female patients. The positivity of Hpylori in EBV-associated and EBV-negative gastric carcinomas was 46.15% (6/13) and 81.40%(104/172) respectively. There was no significant correlation between EBV and H pylori infection. The c-met overexpression was significantly higher in the EBVaGC group than in the EBVnGC group. However, c-met and c-myc expression did not show significant difference between the two groups. Transcripts of EBNA1 were detected in all 13 EBVaGCs, while both EBNA2 and LMP1 mRNA were not detected. Six of the 13 cases exhibited BARF1 transcripts and 2 exhibited BHRF1 transcripts. CONCLUSION: The positivity of H pylori in EBVnGCs is higher than that of EBVaGCs, but no significant correlation is found between EBV infection and H pylori infection. H pylori-positive gastric carcinoma is predominant in antrum location, while EBVaGC has a tendency of predominance in cardia/body location. EBV infection is associated with c-met abnormal expression but not with c-myc protein in EBVaGC. c-met overexpression is not induced by LMP1. BARF1 and BHRF1 may play important roles in the tumorigenesis of EBVaGC through different pathways.展开更多
We study the global pressure of a one-dimensional polydisperse granular gases system for the first time, in which the size distribution of particles has the fractal characteristic and the inhomogeneity is described by...We study the global pressure of a one-dimensional polydisperse granular gases system for the first time, in which the size distribution of particles has the fractal characteristic and the inhomogeneity is described by a fractal dimension D. The particles are driven by Gaussian white noise and subject to inelastic mutual collisions. We define the global pressure P of the system as the impulse transferred across a surface in a unit of time, which has two contributions, one from the translational motion of particles and the other from the collisions. Explicit expression for the global pressure in the steady state is derived. By molecular dynamics simulations, we investigate how the inelasticity of collisions and the inhomogeneity of the particles influence the global pressure. The simulation results indicate that the restitution coefficient e and the fractal dimension D have significant effect on the pressure.展开更多
In the presence of Gaussian white noise,we study the properties of voltage-controlled oscillator neuronmodel and discuss the effects of the additive and multiplicative noise.It is found that the additive noise can acc...In the presence of Gaussian white noise,we study the properties of voltage-controlled oscillator neuronmodel and discuss the effects of the additive and multiplicative noise.It is found that the additive noise can accelerate andcounterwork the firing of neuron,which depends on the value of central frequency of neuron itself,while multiplicativenoise can induce the continuous change or mutation of membrane potential.展开更多
We present a model of non-uniform granular gases in one-dimensional case, whose granularity distribution has the fractal characteristic. We have studied the nonequilibrium properties of the system by means of Monte Ca...We present a model of non-uniform granular gases in one-dimensional case, whose granularity distribution has the fractal characteristic. We have studied the nonequilibrium properties of the system by means of Monte Carlo method. When the typical relaxation time T of the Brownian process is greater than the mean collision time To, the energy evolution of the system exponentially decays, with a tendency to achieve a stable asymptotic value, and the system finally reaches a nonequilibrium steady state in which the velocity distribution strongly deviates from the Gaussian one. Three other aspects have also been studied for the steady state: the visualized change of the particle density, the entropy of the system and the correlations in the velocity of particles. And the results of simulations indicate that the system has strong spatial clustering; Furthermore, the influence of the inelasticity and inhomogeneity on dynamic behaviors have also been extensively investigated, especially the dependence of the entropy and the correlations in the velocity of particles on the restitute coefficient e and the fractal dimension D.展开更多
The phenomenon of the resonant activation (RA) of a particle over a fluctuating potential barrier with a four-value noise is investigated. It is shown that the mean first passage time (MFPT) displays six minima as...The phenomenon of the resonant activation (RA) of a particle over a fluctuating potential barrier with a four-value noise is investigated. It is shown that the mean first passage time (MFPT) displays six minima as the function of the transition rates γ1, γ2, γ3, γ4, γ5, and 76 of the four-value noise, respectively. In addition, the effect of other parameters of the system, such as the noise strength D of the additive Gaussian white noise and the parameter value a, b, c, and d of the four-value noise, on the RAs is also investigated.展开更多
The effect of small-world connection and noise on of Hodgkin-Huxley neurons are investigated in detail. Some the formation and transition of spiral wave in the networks interesting results are found in our numerical s...The effect of small-world connection and noise on of Hodgkin-Huxley neurons are investigated in detail. Some the formation and transition of spiral wave in the networks interesting results are found in our numerical studies, i) The quiescent neurons are activated to propagate electric signal to others by generating and developing spiral wave from spiral seed in small area. ii) A statistical factor is defined to describe the collective properties and phase transition induced by the topology of networks and noise, iii) Stable rotating spiral wave can be generated and keeps robust when the rewiring probability is below certain threshold, otherwise, spiral wave can not be developed from the spiral seed and spiral wave breakup occurs for a stable rotating spiral wave. iv) Gaussian white noise is introduced on the membrane of neurons to study the noise-induced phase transition on spiral wave in small-world networks of neurons. It is confirmed that Ganssian white noise plays active role in supporting and developing spiral wave in the networks of neurons, and appearance of smaller factor of synchronization indicates high possibility to induce spiral wave.展开更多
Latent membrane protein 1 (LMP1), an important protein encoded by Epstein Barr virus (EBV), has been implied to link with the pathogenesis of nasopharyngeal carcinoma (NPC). Its dual effects of increasing cell p...Latent membrane protein 1 (LMP1), an important protein encoded by Epstein Barr virus (EBV), has been implied to link with the pathogenesis of nasopharyngeal carcinoma (NPC). Its dual effects of increasing cell proliferation and inhibiting cell apoptosis have been confirmed. In this study, we showed that the expression of Survivin and CDK4 protein in CNE-LMP1, a LMP1 positive NPC epithelial cell line, is higher than in LMP1 negative NPC epithelial cell line- CNE1, and the expression is LMP1 dosage-dependent. Although it was reported that Survivin specifically expressed in cell cycle G2/M phase, our studies suggested that LMP1 could promote the expression of Survivin in G0/G1, S and G2/ M phase. It also showed that Survivin and CDK4 could be accumulated more in the nuclei triggered by LMP1. More interestingly, Survivin and CDK4 could form a protein complex in the nuclei of CNE-LMP1 rather than in that of CNE1, which demonstrated that the interaction between these two proteins could be promoted by LMPI. These results strongly suggested that the role of LMP1 in the regulation of Survivin and CDK4 may also shed some light on the mechanism research of LMP1 in NPC.展开更多
基金supported by the Scientific Research Starting Foundation of HoHai University, China (No. 2084/40801136)the Fundamental Research Funds for the Central Universities (No.2009B12514).
文摘In order to enhance geological body boundary visual effects in images and improve interpretation accuracy using gravity and magnetic field data, we propose an improved small sub-domain filtering method to enhance gravity anomalies and gravity gradient tensors. We discuss the effect of Gaussian white noise on the improved small sub-domain filtering method, as well as analyze the effect of window size on geological body edge recognition at different extension directions. Model experiments show that the improved small sub-domain filtering method is less affected by noise, filter window size, and geological body edge direction so it can more accurately depict geological body edges than the conventional small sub-domain filtering method. It also shows that deeply buried body edges can be well delineated through increasing the filter window size. In application, the enhanced gravity anomalies and calculated gravity gradient tensors of the Hulin basin show that the improved small sub-domain filtering can recognize more horizontal fault locations than the conventional method.
基金Supported by Natural Science Foundation of Jilin Province(201115221)~~
文摘[Objective] This study aimed to investigate the effects of temperature on determination of protein concentration with Coomassie Brilliant Blue method,thus proving advice and guidance for accurate determination of protein concentration.[Method] With Coomassie Brilliant Blue method,the concentrations of different bovine serum albumin samples were determined under different temperatures and incubation time.[Result] According to the standard curve,when the determination range of protein concentration was 0-100 mg/ml,the determined protein concentration was relatively stable after incubation at 20 ℃ for 20-30 min.Furthermore,the determination result of higher protein concentration with Coomassie Brilliant Blue method was less affected by various factors.[Conclusion] In determination of protein concentration with Coomassie Brilliant Blue method,temperature,sample concentration and incubation time were important factors affecting the accuracy of experimental results.
文摘By the use of cross-correlation measures, the response of a symmetric Schmitt trigger (ST) driven by a random binary signal and white Gaussian noise is investigated. The results show that the information transmission can be enhanced when a certain amount of noise is presented, i.e., aperiodic stochastic resonance (ASR). Then, the influence of signal amplitude and the ST threshold on ASR is examined, the applicability of the ST in reducing the noise level of random signal transmission and improving the quality of output signal via ASR effect is illustrated. This research is of great interest in the field of digital communications.
基金the National Natural Science Foundation of China under Grant 61371125
文摘Based on the anti-jamming performance of differential frequency hopping (DFH) systems in Additive White Gaussian Noise (AWGN) channel, Fountain code is introduced to the DFH systems as the outer error correcting code in this paper to investigate the improvements against partial-band jamming over AWGN channel. The performance of Fountain coded DFH is theoretically analyzed and numerically simulated. The total frequency of hopping in the simulation is 16, and results show that, on one hand, when exact jamming state information (JSI) is available, and the number of jamming frequency is n= 16, the bit error rate (BER) of 10~3 is achieved with the signal to interference ratio (SIR) approximately 7.5 dB over AWGN channel, and the performance improves about 1-1.5dB compared with the no-coded system. When the number of jamming frequency is n=2, the performance increases 15-17dB. On the other hand, when JSI is unavailable, a joint JSI estimation and decoding algorithm is proposed. The BER of 10 3 is achieved with jamming-frequency n 16, SIR=8dB and signal noise ratio (SNR) 10dB over AWGN channel. It's proved that this algorithm provides robust anti-jamming pertbrmance even without JSI. The anti-jamming performance of Fountain coded DFH systems is obviously superior to no-coded DFH systems.
文摘The electromagnetic radiation (EMR) signal collected by monitoring system during coal or rock dynamic disaster may be interferred easily by electromagnetic noises in mines. The noises have a direct influence on the recognition and analysis of the EMR signal features during the disaster. With the aim of removing these noises, an ensemble empirical mode decomposition (EEMD) adaptive morphological filter was proposed. From the result of the simulation and the experiment, it is shown that the method can restrain the random noise and white Gaussian noise mixed with EMR signal effectively. The filter is highly useful for improving the robustness of the coal or rock dynamic disaster monitoring system.
基金supported by the National Natural Science Foundation of China(No.61601045,No.91438114 and No.61372111)
文摘Constant envelope orthogonal frequency division multiplexing(CE-OFDM) is a waveform that can achieve 0d B peak-to-average power ratio and avoid the signal distortion caused by the nonlinear power amplifi er. However, the carrier frequency offset(CFO) in CE-OFDM systems can cause errors at phase unwrapper module. In this paper, a CFO estimation scheme is proposed for CEOFDM in satellite communication system. As the null subcarrier is inherent in the conjugate symmetric symbol structure at the transmitter, the proposed scheme uses the null subcarrier as prior information to estimate the CFO at the receiver. The ideal estimation range of normalized CFO is obtained by mathematical analysis. Simulation results show that the proposed scheme can estimate the CFO accurately under additive white Gaussian noise(AWGN) channel and multipath fading channel, especially for moderate and high signal-to-noise ratio(SNR).
文摘In this paper, a novel detection criterion is proposed to decide whether primary user(PU) exists based on joint analysis of the variance and correlation for observation signal,considering a correlation within the observed signal. Simultaneously, the corresponding detection thresholds are also designed. Simulation experiments verify the proposed method suits for the observation signal in Additive White Gaussian Noise(AWGN), Rayleigh,Rician channel and the detection performance is improved greatly.
文摘AIM: To investigate the interrelationship between Epstein-Barr virus (EBV)-encoded proteins and cell proliferation, apoptosis and apoptosis-related proteins in gastric carcinoma, and to explore their role in gastric carcinogenesis. METHODS: Tissues from 13 cases of EBV-associated gastric carcinoma (EBVaGC) and 45 cases of matched EBV-negative gastric carcinoma (EBVnGC) were collected, and then subjected to analysis for apoptotic index (AI) using the terminal deoxynucleotidyl transferase (TdT)-mediated dUTP-biotin nick end-labeling (TUNEL) assay. Nuclear cell proliferation-associated antigen ki-67 index (KI), bcl-2, and p53 expression were examined by immunohistochemistry.p53 mutation in exons 5-8 of 13 EBVaGC cases was determined by single-strand conformation polymorphism (SSCP) and DNA sequencing.RT-PCR and Southern hybridization were used to detect the expression of nuclear antigens (EBNAs) 1 and 2, latent membrane protein (IMP) 1, immediately early gene BZLF1 and early genes BARF1 and BHRF1 in 13 EBVaGC cases. RESULTS: The percentage of AI, KI and p53 overexpression was significantly lower in the EBVaGC group than in the EBVnGC group. However, bcl-2 expression did not show significant difference between the two groups. p53 gene mutations were not found in 13 EBVaGCs. Transcripts of EBNA1 were detected in all 13 EBVaGCs, while both EBNA2 and LMP1 mRNA were not detected. Six of the thirteen cases exhibited BZLF1 transcripts and two exhibited BHRF1 transcripts. BARF1 mRNA was detected in six cases. CONCLUSION: Lower AI and KI may reflect a low biological activity in EBVaGC. EBV infection is associated with p53 abnormal expression but not bcl-2 protein in EBVaGC. BZLF1,BARF1,and BHRF1 may play important roles in inhibiting cell apoptosis and tumorigenesis of EBVaGC through different pathways.
文摘AIM: To investigate the interrelationship of Epstein-Barr virus (EBV) and EBV- encoded proteins with Helicobacter pylori (H pylor/~ infection and the expression of c-met and c-myc oncogene proteins in gastric carcinoma, and to explore their role in gastric carcinogenesis. METHODS: One hundred and eighty-five gastric carcinoma tissues were detected by polymerase chain reaction (PCR)-Southern blot for EBV genome and in situ hybridization (ISH) for EBV-encoded small RNA 1 (EBER1). Gastric carcinoma with positive EBER1 signals was confirmed EBV-associated gastric carcinoma (EBVaGC). The status of Hpylori infection in 185 gastric carcinomas was assessed by rapid urease test and PCR. The samples with positive PCR and urease test were defined as H pylorl infection. The expression of c-met and c-myc oncogene proteins in tissues of EBVaGC and matched EBV-negative gastric carcinoma (EBVnGC) were examined by immunohistochemistry. RT-PCR and Southern hybridization were used to detect the expression of nuclear antigens (EBNAs) 1 and 2, latent membrane protein (LMP) 1, early genes BARF1 and BHRF1 in EBVaGC cases. RESULTS: The positive rate of H pylori and EBV in 185 gastric carcinomas was 59.45% (110/185) and 7.03% (13/185) respectively. No difference was found in sex, age, pathological differentiation, clinical stages and lymph node metastasis between H pylori-positive and H pylori-negative gastric carcinomas. However, the positive rate of H pylori infection in the antrum gastric carcinomas was higher than that of cardia and body gastric carcinomas. In our series, age, pathological differentiation, clinical stages, lymph node metastasis and location of cancer were not different between EBVnGC and EBVaGC, while the positive rate of EBV in male patients was significantly higher than that of female patients. The positivity of Hpylori in EBV-associated and EBV-negative gastric carcinomas was 46.15% (6/13) and 81.40%(104/172) respectively. There was no significant correlation between EBV and H pylori infection. The c-met overexpression was significantly higher in the EBVaGC group than in the EBVnGC group. However, c-met and c-myc expression did not show significant difference between the two groups. Transcripts of EBNA1 were detected in all 13 EBVaGCs, while both EBNA2 and LMP1 mRNA were not detected. Six of the 13 cases exhibited BARF1 transcripts and 2 exhibited BHRF1 transcripts. CONCLUSION: The positivity of H pylori in EBVnGCs is higher than that of EBVaGCs, but no significant correlation is found between EBV infection and H pylori infection. H pylori-positive gastric carcinoma is predominant in antrum location, while EBVaGC has a tendency of predominance in cardia/body location. EBV infection is associated with c-met abnormal expression but not with c-myc protein in EBVaGC. c-met overexpression is not induced by LMP1. BARF1 and BHRF1 may play important roles in the tumorigenesis of EBVaGC through different pathways.
基金The project supported by National Natural Science Foundation of China under Grant Nos. 10675048 and 10604017 and Natural Science Foundation of Xianning College under Grant No. KZ0627
文摘We study the global pressure of a one-dimensional polydisperse granular gases system for the first time, in which the size distribution of particles has the fractal characteristic and the inhomogeneity is described by a fractal dimension D. The particles are driven by Gaussian white noise and subject to inelastic mutual collisions. We define the global pressure P of the system as the impulse transferred across a surface in a unit of time, which has two contributions, one from the translational motion of particles and the other from the collisions. Explicit expression for the global pressure in the steady state is derived. By molecular dynamics simulations, we investigate how the inelasticity of collisions and the inhomogeneity of the particles influence the global pressure. The simulation results indicate that the restitution coefficient e and the fractal dimension D have significant effect on the pressure.
基金National Natural Science Foundation of China under Grant No.30600122Natural Science Foundation of Guangdong Province of China under Grant No.06025073the Natural Science Foundation of South China University of Technology under Grant No.B14-E5050200
文摘In the presence of Gaussian white noise,we study the properties of voltage-controlled oscillator neuronmodel and discuss the effects of the additive and multiplicative noise.It is found that the additive noise can accelerate andcounterwork the firing of neuron,which depends on the value of central frequency of neuron itself,while multiplicativenoise can induce the continuous change or mutation of membrane potential.
基金The project supported by National Natural Science of China under Grant No. 10675408 and Natural Science Foundation of Xianning College under Grant No. KZ0627
文摘We present a model of non-uniform granular gases in one-dimensional case, whose granularity distribution has the fractal characteristic. We have studied the nonequilibrium properties of the system by means of Monte Carlo method. When the typical relaxation time T of the Brownian process is greater than the mean collision time To, the energy evolution of the system exponentially decays, with a tendency to achieve a stable asymptotic value, and the system finally reaches a nonequilibrium steady state in which the velocity distribution strongly deviates from the Gaussian one. Three other aspects have also been studied for the steady state: the visualized change of the particle density, the entropy of the system and the correlations in the velocity of particles. And the results of simulations indicate that the system has strong spatial clustering; Furthermore, the influence of the inelasticity and inhomogeneity on dynamic behaviors have also been extensively investigated, especially the dependence of the entropy and the correlations in the velocity of particles on the restitute coefficient e and the fractal dimension D.
基金National Natural Science Foundation of China under Grant No.10375009K.C.Wong Magna Fund in Ningbo University of ChinaNational Natural Science Foundation of China under Grant No.10647134
文摘The phenomenon of the resonant activation (RA) of a particle over a fluctuating potential barrier with a four-value noise is investigated. It is shown that the mean first passage time (MFPT) displays six minima as the function of the transition rates γ1, γ2, γ3, γ4, γ5, and 76 of the four-value noise, respectively. In addition, the effect of other parameters of the system, such as the noise strength D of the additive Gaussian white noise and the parameter value a, b, c, and d of the four-value noise, on the RAs is also investigated.
基金Supported by the Natural Nature Foundation of China under Grant Nos.10747005,10972179the Nature Foundation of Lanzhou University of Technology under Grant No.Q200706
文摘The effect of small-world connection and noise on of Hodgkin-Huxley neurons are investigated in detail. Some the formation and transition of spiral wave in the networks interesting results are found in our numerical studies, i) The quiescent neurons are activated to propagate electric signal to others by generating and developing spiral wave from spiral seed in small area. ii) A statistical factor is defined to describe the collective properties and phase transition induced by the topology of networks and noise, iii) Stable rotating spiral wave can be generated and keeps robust when the rewiring probability is below certain threshold, otherwise, spiral wave can not be developed from the spiral seed and spiral wave breakup occurs for a stable rotating spiral wave. iv) Gaussian white noise is introduced on the membrane of neurons to study the noise-induced phase transition on spiral wave in small-world networks of neurons. It is confirmed that Ganssian white noise plays active role in supporting and developing spiral wave in the networks of neurons, and appearance of smaller factor of synchronization indicates high possibility to induce spiral wave.
基金National Nature Science Foundation for Distinguished Young Scholar of China (No.39525022)National Basic Research Program(No.2004CB518703) National Nature Science Foundation of China (No.30570085).
文摘Latent membrane protein 1 (LMP1), an important protein encoded by Epstein Barr virus (EBV), has been implied to link with the pathogenesis of nasopharyngeal carcinoma (NPC). Its dual effects of increasing cell proliferation and inhibiting cell apoptosis have been confirmed. In this study, we showed that the expression of Survivin and CDK4 protein in CNE-LMP1, a LMP1 positive NPC epithelial cell line, is higher than in LMP1 negative NPC epithelial cell line- CNE1, and the expression is LMP1 dosage-dependent. Although it was reported that Survivin specifically expressed in cell cycle G2/M phase, our studies suggested that LMP1 could promote the expression of Survivin in G0/G1, S and G2/ M phase. It also showed that Survivin and CDK4 could be accumulated more in the nuclei triggered by LMP1. More interestingly, Survivin and CDK4 could form a protein complex in the nuclei of CNE-LMP1 rather than in that of CNE1, which demonstrated that the interaction between these two proteins could be promoted by LMPI. These results strongly suggested that the role of LMP1 in the regulation of Survivin and CDK4 may also shed some light on the mechanism research of LMP1 in NPC.