Using observational data and the pre-industrial simulations of 19 models from the Coupled Model Intercomparison Project Phase 5（CMIP5）, the El Ni o（EN） and La Ni a（LN） events in positive and negative Pacific Dec...Using observational data and the pre-industrial simulations of 19 models from the Coupled Model Intercomparison Project Phase 5（CMIP5）, the El Ni o（EN） and La Ni a（LN） events in positive and negative Pacific Decadal Oscillation（PDO） phases are examined. In the observational data, with EN（LN） events the positive（negative） SST anomaly in the equatorial eastern Pacific is much stronger in positive（negative） PDO phases than in negative（positive） phases. Meanwhile,the models cannot reasonably reproduce this difference. Besides, the modulation of ENSO frequency asymmetry by the PDO is explored. Results show that, in the observational data, EN is 300% more（58% less） frequent than LN in positive（negative）PDO phases, which is significant at the 99% confidence level using the Monte Carlo test. Most of the CMIP5 models exhibit results that are consistent with the observational data.展开更多
High-frequency magnetic properties, such as core loss, coercivity and amplitude permeabilityof a newly-developed nanocrystalline Fe72.5Cu1Nb2V2Si13.5B9 alloy in the wide ranges of f =20-103 kHz, Bm = 0.01~0.6 T and Bm...High-frequency magnetic properties, such as core loss, coercivity and amplitude permeabilityof a newly-developed nanocrystalline Fe72.5Cu1Nb2V2Si13.5B9 alloy in the wide ranges of f =20-103 kHz, Bm = 0.01~0.6 T and Bmf = 10~40 (T.kHz) have been measured. A largeamount of experimental data have been fitted by a computer, thus obtaining several expressionsrepresenting the influence of frequency on high-frequency magnetic properties, that are useful inpractical applications.展开更多
Objective:To investigate the effects of routine rehabilitation therapy combined with low frequency head stimulation on monoamine neurotransmitters, neuron-specific enolase (NSE), endothelin-1 (ET-1) and cerebral hemod...Objective:To investigate the effects of routine rehabilitation therapy combined with low frequency head stimulation on monoamine neurotransmitters, neuron-specific enolase (NSE), endothelin-1 (ET-1) and cerebral hemodynamics in children with cerebral palsy.Methods:From January 2017 to June 2018, 110 children with cerebral palsy were randomly divided into observation group (55 cases) and control group (55 cases). The control group received routine rehabilitation treatment, while the observation group received low-frequency head stimulation on the basis of routine rehabilitation treatment. The changes of dopamine (DA), norepinephrine (NE), serotonin (5-HT), NSE, ET-1 levels and mean blood flow velocity of anterior cerebral artery (ACA), middle cerebral artery (MCA), posterior cerebral artery (PCA) were compared in two groups.Results:Before treatment, there was no significant difference in DA, NE and 5-HT levels in two groups. After treatment, DA, NE and 5-HT levels in the observation group were (192.23±22.71) ng/mL, (98.02±11.71) ng/L, (210.07±25.03) ng/L, and in the control group. the DA, NE, 5-HT levels were (147.06±17.02) ng/mL, (83.07±11.15) ng/L, and (171.88±20.45) ng/L, respectively. The DA, NE and 5-HT levels in two groups were higher than those before treatment, and DA, NE and 5-HT levels in the observation group were higher than those in the control group. Before treatment, there was no significant difference in NSE and ET-1 levels between the two groups. After treatment, the NSE and ET-1 levels in the observation group were (7.97±2.07) μg/L and (41.01±10.07) pg/mL, and the NSE and ET-1 levels in the control group were (10.38±3.02) μg/L, (58.46±15.02) pg/mL, respectively. the NSE and ET-1 in two groups were lower than those before treatment, and the NSE and ET-1 of the observation group were lower than the control group. Before treatment, there was no significant difference in mean blood flow velocity between ACA, MCA and PCA. After treatment, the mean blood flow velocities of ACA, MCA, and PCA in the observation group were (46.88±7.72) cm/s, (59.85±10.18) cm/s, and (49.15±7.02) cm/s, respectively, which was significantly higher than before treatment and higher than that of the control group in the same period.Conclusion: Conventional rehabilitation combined with low-frequency electrical stimulation of the head can effectively increase the content of monoamine neurotransmitters in children with cerebral palsy, enhance cerebral blood circulation, and reduce brain damage.展开更多
In this work,we address the frequency estimation problem of a complex single-tone embedded in the heavy-tailed noise.With the use of the linear prediction(LP)property and l_(1)-norm minimization,a robust frequency est...In this work,we address the frequency estimation problem of a complex single-tone embedded in the heavy-tailed noise.With the use of the linear prediction(LP)property and l_(1)-norm minimization,a robust frequency estimator is developed.Since the proposed method employs the weighted l_(1)-norm on the LP errors,it can be regarded as an extension of the l_(1)-generalized weighted linear predictor.Computer simulations are conducted in the environment of α-stable noise,indicating the superiority of the proposed algorithm,in terms of its robust to outliers and nearly optimal estimation performance.展开更多
This paper is part of a research under enhancement since 2001, in which the main objective is to measure small dynamic displacements by analysis of L1 GPS carrier frequency with 1575.42 MHz—wavelength 19.05 cm, under...This paper is part of a research under enhancement since 2001, in which the main objective is to measure small dynamic displacements by analysis of L1 GPS carrier frequency with 1575.42 MHz—wavelength 19.05 cm, under an adaptive method for collecting data and filtering techniques. This method, named Phase Residual Method (PRM) is based on the frequency domain analysis of the phase residuals resulted from the L1 double difference static data processing of two satellites in almost orthogonal elevation angle. In this work it is proposed to obtain the phase residuals directly from the raw phase observable collected in a short baseline during a limited time span, in lieu of obtaining the residual data file from regular GPS processing programs. In order to improve the ability to detect millimetric displacements, two filtering techniques are introduced. The first one is the autocorrelation that reduces the phase noise with random time behavior. The other one is the running mean to separate low frequency from the high frequency phase sources. Two trials are presented to verify the proposed method and filtering techniques applied. One simulates a 2.5 millimeter vertical GPS antenna displacement and the second using the data collected during a bridge dynamic load test. The results show a good consistency to detect millimetric oscillations from L1 frequency and filtering techniques.展开更多
BACKGROUND： Electromagnetic radiation can influence dopamine （DA） synthesis in brain tissues or ceils, but electromagnetic frequencies, intensities, and radiation time can produce different effects. In addition, th...BACKGROUND： Electromagnetic radiation can influence dopamine （DA） synthesis in brain tissues or ceils, but electromagnetic frequencies, intensities, and radiation time can produce different effects. In addition, the signal pathway by which electromagnetic radiation influences DA synthesis remains controversial. OBJECTIVE： To determine tyrosine hydroxylase （TH） expression in PC12 cells and DA levels in cell culture media after different periods of low-frequency pulsed electric field （LF-PEF） stimulation, and to determine how LF-PEF signaling stimulates TH synthesis using inhibitors. DESIGN, TIME AND SETTING： A parallel, controlled, cell experiment was performed at the Laboratory of Cell Biology, School of Life Science, East China Normal University, between January and October 2006. MATERIALS： PC12 cells were purchased from the Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, China. Nerve growth factor was purchased from PeproTech, USA. The protein kinase A inhibitor, H-89, and mitogen-activated protein kinase kinase inhibitor, U0126, were purchased from Sigma, USA. METHODS： （1） Following routine culture in Dulbecco＇s modified eagle medium, primary PC12 cells were stimulated under LF-PEF （pulse frequency 50.Hz, pulse width 20 μs, peak field strength 1 V/m） for 5, 10, 15, 20, and 30 minutes. （2） Inhibitors （H-89 or U0126, 1 μmol/L） were added 30 minutes before LF-PEF stimulation for 10 minutes. MAIN OUTCOME MEASURES： （1） TH expression was determined by Western blot in PC12 cells at 0.5, 1,2, 3, and 4 days after LF-PEF stimulation. Similarly, DA was measured by high-performance liquid chromatography in media at 2, 3, 4, or 5 days after LF-PEE （2） TH expression was detected 1 day after H-89 or U0126 treatment and LF-PEE RESULTS： （1） Short-term LF-PEF stimulation （5 and 10 minutes） increased TH expression and media DA levels after short-term culture （2 days） （P 〈 0.01）, but both parameters decreased with longer culture （3 4 days） （P 〈 0.01）. Long-term LF-PEF stimulation （15, 20, or 30 minutes） decreased TH and DA synthesis, followed by a rapid increase （P 〈 0.01）. （2） H89 could completely inhibit TH expression in PC12 cells stimulated by LF-PEF for 10 minutes, while the inhibition rate of U0126 was 53.2%. CONCLUSION： Short-term LF-PEF first promotes then inhibits, while long-term LF-PEF first inhibits then promotes, TH and DA synthesis. LF-PEF stimulation regulates TH expression primarily by activating protein kinase A to regulate DA synthesis.展开更多
基金supported by the National Key R&D Program of China (Grant No.2017YFA0604201)the National Natural Science Foundation of China (Grant Nos.41576019,41606027 and 41706028)the China Postdoctoral Science Foundation (Grant No.2015M571095)
文摘Using observational data and the pre-industrial simulations of 19 models from the Coupled Model Intercomparison Project Phase 5（CMIP5）, the El Ni o（EN） and La Ni a（LN） events in positive and negative Pacific Decadal Oscillation（PDO） phases are examined. In the observational data, with EN（LN） events the positive（negative） SST anomaly in the equatorial eastern Pacific is much stronger in positive（negative） PDO phases than in negative（positive） phases. Meanwhile,the models cannot reasonably reproduce this difference. Besides, the modulation of ENSO frequency asymmetry by the PDO is explored. Results show that, in the observational data, EN is 300% more（58% less） frequent than LN in positive（negative）PDO phases, which is significant at the 99% confidence level using the Monte Carlo test. Most of the CMIP5 models exhibit results that are consistent with the observational data.
文摘High-frequency magnetic properties, such as core loss, coercivity and amplitude permeabilityof a newly-developed nanocrystalline Fe72.5Cu1Nb2V2Si13.5B9 alloy in the wide ranges of f =20-103 kHz, Bm = 0.01~0.6 T and Bmf = 10~40 (T.kHz) have been measured. A largeamount of experimental data have been fitted by a computer, thus obtaining several expressionsrepresenting the influence of frequency on high-frequency magnetic properties, that are useful inpractical applications.
文摘Objective:To investigate the effects of routine rehabilitation therapy combined with low frequency head stimulation on monoamine neurotransmitters, neuron-specific enolase (NSE), endothelin-1 (ET-1) and cerebral hemodynamics in children with cerebral palsy.Methods:From January 2017 to June 2018, 110 children with cerebral palsy were randomly divided into observation group (55 cases) and control group (55 cases). The control group received routine rehabilitation treatment, while the observation group received low-frequency head stimulation on the basis of routine rehabilitation treatment. The changes of dopamine (DA), norepinephrine (NE), serotonin (5-HT), NSE, ET-1 levels and mean blood flow velocity of anterior cerebral artery (ACA), middle cerebral artery (MCA), posterior cerebral artery (PCA) were compared in two groups.Results:Before treatment, there was no significant difference in DA, NE and 5-HT levels in two groups. After treatment, DA, NE and 5-HT levels in the observation group were (192.23±22.71) ng/mL, (98.02±11.71) ng/L, (210.07±25.03) ng/L, and in the control group. the DA, NE, 5-HT levels were (147.06±17.02) ng/mL, (83.07±11.15) ng/L, and (171.88±20.45) ng/L, respectively. The DA, NE and 5-HT levels in two groups were higher than those before treatment, and DA, NE and 5-HT levels in the observation group were higher than those in the control group. Before treatment, there was no significant difference in NSE and ET-1 levels between the two groups. After treatment, the NSE and ET-1 levels in the observation group were (7.97±2.07) μg/L and (41.01±10.07) pg/mL, and the NSE and ET-1 levels in the control group were (10.38±3.02) μg/L, (58.46±15.02) pg/mL, respectively. the NSE and ET-1 in two groups were lower than those before treatment, and the NSE and ET-1 of the observation group were lower than the control group. Before treatment, there was no significant difference in mean blood flow velocity between ACA, MCA and PCA. After treatment, the mean blood flow velocities of ACA, MCA, and PCA in the observation group were (46.88±7.72) cm/s, (59.85±10.18) cm/s, and (49.15±7.02) cm/s, respectively, which was significantly higher than before treatment and higher than that of the control group in the same period.Conclusion: Conventional rehabilitation combined with low-frequency electrical stimulation of the head can effectively increase the content of monoamine neurotransmitters in children with cerebral palsy, enhance cerebral blood circulation, and reduce brain damage.
文摘In this work,we address the frequency estimation problem of a complex single-tone embedded in the heavy-tailed noise.With the use of the linear prediction(LP)property and l_(1)-norm minimization,a robust frequency estimator is developed.Since the proposed method employs the weighted l_(1)-norm on the LP errors,it can be regarded as an extension of the l_(1)-generalized weighted linear predictor.Computer simulations are conducted in the environment of α-stable noise,indicating the superiority of the proposed algorithm,in terms of its robust to outliers and nearly optimal estimation performance.
文摘This paper is part of a research under enhancement since 2001, in which the main objective is to measure small dynamic displacements by analysis of L1 GPS carrier frequency with 1575.42 MHz—wavelength 19.05 cm, under an adaptive method for collecting data and filtering techniques. This method, named Phase Residual Method (PRM) is based on the frequency domain analysis of the phase residuals resulted from the L1 double difference static data processing of two satellites in almost orthogonal elevation angle. In this work it is proposed to obtain the phase residuals directly from the raw phase observable collected in a short baseline during a limited time span, in lieu of obtaining the residual data file from regular GPS processing programs. In order to improve the ability to detect millimetric displacements, two filtering techniques are introduced. The first one is the autocorrelation that reduces the phase noise with random time behavior. The other one is the running mean to separate low frequency from the high frequency phase sources. Two trials are presented to verify the proposed method and filtering techniques applied. One simulates a 2.5 millimeter vertical GPS antenna displacement and the second using the data collected during a bridge dynamic load test. The results show a good consistency to detect millimetric oscillations from L1 frequency and filtering techniques.
基金the National Natural Science Foundation of China,No.50677022
文摘BACKGROUND： Electromagnetic radiation can influence dopamine （DA） synthesis in brain tissues or ceils, but electromagnetic frequencies, intensities, and radiation time can produce different effects. In addition, the signal pathway by which electromagnetic radiation influences DA synthesis remains controversial. OBJECTIVE： To determine tyrosine hydroxylase （TH） expression in PC12 cells and DA levels in cell culture media after different periods of low-frequency pulsed electric field （LF-PEF） stimulation, and to determine how LF-PEF signaling stimulates TH synthesis using inhibitors. DESIGN, TIME AND SETTING： A parallel, controlled, cell experiment was performed at the Laboratory of Cell Biology, School of Life Science, East China Normal University, between January and October 2006. MATERIALS： PC12 cells were purchased from the Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, China. Nerve growth factor was purchased from PeproTech, USA. The protein kinase A inhibitor, H-89, and mitogen-activated protein kinase kinase inhibitor, U0126, were purchased from Sigma, USA. METHODS： （1） Following routine culture in Dulbecco＇s modified eagle medium, primary PC12 cells were stimulated under LF-PEF （pulse frequency 50.Hz, pulse width 20 μs, peak field strength 1 V/m） for 5, 10, 15, 20, and 30 minutes. （2） Inhibitors （H-89 or U0126, 1 μmol/L） were added 30 minutes before LF-PEF stimulation for 10 minutes. MAIN OUTCOME MEASURES： （1） TH expression was determined by Western blot in PC12 cells at 0.5, 1,2, 3, and 4 days after LF-PEF stimulation. Similarly, DA was measured by high-performance liquid chromatography in media at 2, 3, 4, or 5 days after LF-PEE （2） TH expression was detected 1 day after H-89 or U0126 treatment and LF-PEE RESULTS： （1） Short-term LF-PEF stimulation （5 and 10 minutes） increased TH expression and media DA levels after short-term culture （2 days） （P 〈 0.01）, but both parameters decreased with longer culture （3 4 days） （P 〈 0.01）. Long-term LF-PEF stimulation （15, 20, or 30 minutes） decreased TH and DA synthesis, followed by a rapid increase （P 〈 0.01）. （2） H89 could completely inhibit TH expression in PC12 cells stimulated by LF-PEF for 10 minutes, while the inhibition rate of U0126 was 53.2%. CONCLUSION： Short-term LF-PEF first promotes then inhibits, while long-term LF-PEF first inhibits then promotes, TH and DA synthesis. LF-PEF stimulation regulates TH expression primarily by activating protein kinase A to regulate DA synthesis.
