When the synthetic aperture focusing technology （SAFT） is used for the detection of the concrete, the signal-to-noise ratio （SNR） and detection depth are not satisfactory. Therefore, the application of SAFT is usu...When the synthetic aperture focusing technology （SAFT） is used for the detection of the concrete, the signal-to-noise ratio （SNR） and detection depth are not satisfactory. Therefore, the application of SAFT is usually limited. In this paper, we propose an improved SAFT technique for the detection of concrete based on the pulse compression technique used in the Radar domain. The proposed method first transmits a linear frequency modulation （LFM） signal, and then compresses the echo signal using the matched filtering method, after which a compressed signal with a narrower main lobe and higher SNR is obtained. With our improved SAFT, the compressed signals are manipulated in the imaging process and the image contrast is improved. Results show that the SNR is improved and the imaging resolution is guaranteed compared with the conventional short-pulse method. From theoretical and experimental results, we show that the proposed method can suppress noise and improve imaging contrast, and can also be used to detect multiple defects in concrete.展开更多
In vertebrates, non-lens βγ-crystallins are widely expressed in various tissues and their functions are not well known. The molecular mechanisms of trefoil factors （TFFs）, which involved in mucosal healing and tum...In vertebrates, non-lens βγ-crystallins are widely expressed in various tissues and their functions are not well known. The molecular mechanisms of trefoil factors （TFFs）, which involved in mucosal healing and tumorigenesis, have remained elusive. βγ-CAT is a novel multifunctional protein complex of non-lens βγ-crystallin and trefoil factor from frog skin secretions. Here we report that βγ-CAT could induce sustained contraction of isolated rabbit aortic rings in dosage （2-35nmol/L） and endothelium dependent manners （P〈0.01 ）. In addition, in situ immunofluorescence indicated that positive TNF-α signals were mainly detected at the endothelial cell layer of βγ-CAT （25nmol/L） treated rings. Furthermore, βγ-CAT induced primary cultured rabbit thoracic aortic endothelial cells （RAECs） rapidly to release TNF-α. After βγ-CAT （25nmol/L） treated for 10 and 30min, the levels of the endothelial cells released TNF-ct were 34.17±5.10 pg/mL and 98.01±4.67 pg/mL （P〈0.01）, respectively. In conclusion, βγ-CAT could induce sustained contraction of isolated aortic rings, and the contractile effect might be partially explained by the release of TNF-α. These findings will give new insight into understanding the functions and physiological roles of non-lens βγ-crystallins and trefoil factors.展开更多
A new type of window called combined window is designed to get higher Ratio of Mainlobe to Sidelobes (RMS) and lower Mainlobe Widening Factor (MWF). Simulation results prove that the new window can solve the contradic...A new type of window called combined window is designed to get higher Ratio of Mainlobe to Sidelobes (RMS) and lower Mainlobe Widening Factor (MWF). Simulation results prove that the new window can solve the contradiction between RMS and MWF better than classic windows.展开更多
As the core of a digital phased array radar system,a radar signal processing environment is created to measure multitarget range and velocity information. The radar echo signal is achieved by superposing target echo, ...As the core of a digital phased array radar system,a radar signal processing environment is created to measure multitarget range and velocity information. The radar echo signal is achieved by superposing target echo, noise, clutter and jamming signals linearly. Considering that these signals have many types,two typical combinations are selected to construct the multi-target echo signal and the simulated echo signal is used as the input of the signal processing environment. This environment mainly adopts pulse compression,moving target indication and detection technologies to process the echo signal.It is found that the frequency domain method is more desirable for the pulse compression effect than the time domain method,and multi-target range information can be measured from the moving target indication result after using a double delay canceller. A new moving target detecting method is proposed,which can present the positive and negative velocity accurately with the multi-target range and velocity measured simultaneously. Simulation results indicate that the potential targets are detected from the chaotic radar echo signals successfully,and their range and velocity can be figured out correctly in the built radar signal processing environment.展开更多
Proposed is a novel optical pulse compression technique based on high-doped erbium fiber amplifier and standard single-mode fiber(SMF). We used the amplifier with the erbium ion concentration of 6.3×10-3 to ampli...Proposed is a novel optical pulse compression technique based on high-doped erbium fiber amplifier and standard single-mode fiber(SMF). We used the amplifier with the erbium ion concentration of 6.3×10-3 to amplify a hyperbolic secant pulse from a regeneratively mode-locked fiber laser. The central wavelength, pulsewidth and peak power of the pulse are 1 550 nm, 12.5 ps and 3 mW, respectively. Then the amplified pulse with peak power level corresponding to a higher-order soliton is compressed when it propagates through a 3-km-long single-mode fiber. Studied are the compressed pulses under different pump powers and fiber lengths. The results show that it can get a narrower pulse, and solve the difficulty that pulses at low power can not be compressed directly in the fiber. And the construct is compact.展开更多
AIM： To investigate the anti-tumor effect of dendritic cells （DCs） pulsed with hsp70-peptide complexes derived from human hepatocellular carcinoma （HCC） cells on human T cells. METHODS： Hsp70-peptide complexes w...AIM： To investigate the anti-tumor effect of dendritic cells （DCs） pulsed with hsp70-peptide complexes derived from human hepatocellular carcinoma （HCC） cells on human T cells. METHODS： Hsp70-peptide complexes were purified from human HCC cells with column chromatography using ADP-agarose and DEAE-Sepharose. DCs were derived from peripheral blood mononuclear cells of healthy donors in the presence of human GM-CSF and IL-4. The anti-tumor effect of DCs pulsed with hsp70-peptide complexes on human T-cell was assayed by CTL and enzyme-linked immunospot （ELISPOT） tests. RESULTS： Hsp70-peptide complexes derived from human HCC cells activated phenotypic and functional maturation of DCs. The matured DCs stimulated a high level of autologous T-cell proliferation and type Ⅰ cytokine secretion, and induced HCC-specific cytotoxic T lymphocytes （CTLs）, which specifically killed HCC cells by a MHC class Ⅰ restricted mechanism. CONCLUSION： Hsp70-peptide complexes derived from human HCC cells can serve as a potent tumor antigen source for pulsing DCs, the pulsed DCs are very effective in activating specific T-cell responses against HCC cells. 2005 The WJG Press and Elsevier Inc. All rights reserved展开更多
AIM:Portopulmonary hypertension is a serious complication of chronic liver disease.Our aim was to search into the effect of terlipressin on systolic pulmonary artery pressure among cirrhotic patients. METHODS:Twelve p...AIM:Portopulmonary hypertension is a serious complication of chronic liver disease.Our aim was to search into the effect of terlipressin on systolic pulmonary artery pressure among cirrhotic patients. METHODS:Twelve patients(6 males and 6 females)with liver cirrhosis were recruited in the study.Arterial blood gas samples were obtained in sitting position at rest.Contrast enhanced echocardiography and measurements of systolic pulmonary artery pressure were performed before and after the intravenous injection of 2 mg terlipressin. RESULTS:Of 12 patients studied,the contrast enhanced echocardiography was positive in 5,and the positive findings in contrast enhanced echocardiography were reversed to normal in two after terlipressin injection.The mean systolic pulmonary artery pressure was 25.5±3.6 mmHg before terlipressin injection,and was 22.5+2.5 mmHg after terlipressin(P=0.003).The systolic pulmonary artery pressure was above 25 mmHg in seven of these 12 patients. After the terlipressin injection,systolic pulmonary artery pressure was<25 mmHg in four of these cases(58.3% vs 25%,P=0.04). CONCLUSION:Terlipressin can decrease the systolic pulmonary artery pressure in patients with liver cirrhosis.展开更多
A nonlinear optical loop mirror constructed from step-decreasing-dispersion fiber instead of DDF is used to compress optical pulse.Numerical simulations show that the effect of the proposed method is close to that of ...A nonlinear optical loop mirror constructed from step-decreasing-dispersion fiber instead of DDF is used to compress optical pulse.Numerical simulations show that the effect of the proposed method is close to that of the method based on DDF.It not only resolves the difficulty of the making of DDF but also makes the design of the system more convenient.展开更多
This paper describes a pulse compressor implementation with DSP for small Time Bandwidth (TB) product Linear Frequency Modulation (LFM) waveform. It contains the digital generation of the LFM waveform and the dig...This paper describes a pulse compressor implementation with DSP for small Time Bandwidth (TB) product Linear Frequency Modulation (LFM) waveform. It contains the digital generation of the LFM waveform and the digital internally Hamming weighted compression filter. Two methods for suppression of time sidelobe of the digital pulse compressor are employed. First, the LFM waveform is modified by using cubic phase pre distortion for reducing the effect of Fresnel ripples in small TB product LFM waveform. Secondly, anti aliasing filter is used before A/D converter for reducing spectrum skirt level of the returned LFM waveform. The parameters of the compression filter implemented with IMSA100 DSP are programmable. The experiments show that the peak time sidelobe level of the digital pulse compressor is less than -32 dB for TB product of 20.展开更多
Objective To examine whether the two vascular paracrine/autocrine factors,angiotensin Ⅱ(Ang Ⅱ)and endothelin,participate in the pathogenesis of arterial calcification.Methods Nicotine and vitamin D_3 treated rats we...Objective To examine whether the two vascular paracrine/autocrine factors,angiotensin Ⅱ(Ang Ⅱ)and endothelin,participate in the pathogenesis of arterial calcification.Methods Nicotine and vitamin D_3 treated rats were studied.Vascular calcification was confirmed by using Von Kossa staining,measurement of calcium content, ^(45)Ca^(2+)uptake assay and alkaline phosphatase(ALP)activity.The plasma and vascular Ang Ⅱ and endothelin levels were measured by using radioimmunoassay.Angiotensinngen and endothehn mRNA levels were determined by RT- PCR.Results The arterial calcium content,^(45)Ca^(2+)uptake and ALP activity were increased in calcification groups compared with control(P<0.01).Administration of the angiotensin receptor antagonist losartan,the endothelin receptor antagonist bosentan,and the angiotensin-converting enzyme inhibitor captopril reduced significantly the arterial calcium content,^(45)Ca^(2+)uptake and ALP activity.In addition,the plasma and aortic Ang Ⅱ and endothelin contents,and vascular angiotensinngen and endothelin mRNA expression were significantly up-regulated(P<0.05). Conclusions These findings suggest that functional renin-angiotensin system and endothelin pathway are involved in vascular calcification,and that activation of these systems could potentiate pathogenesis of arterial calcification.(J Geriatr Cardiol 2004;1(2):108-113.)展开更多
The previous experimental studies have demonstrated that addition of Huang Qi ([symbol: see text] Radix Astragali) to the formulated recipe Sheng Mai Yin ([symbol: see text] Decoction for Pulse-activation) exerts the ...The previous experimental studies have demonstrated that addition of Huang Qi ([symbol: see text] Radix Astragali) to the formulated recipe Sheng Mai Yin ([symbol: see text] Decoction for Pulse-activation) exerts the effects of strengthening the myodynamia, increasing the coronary flow, improving myocardial metabolism, and resisting the arrhythmia. The active component of Huang Lian ([symbol: see text] Rhizoma Coptidis) can prolong the myocardial action potential and antagonize the chloroform-, aconitine-, barium chloride-, epinephrine- or coronary ligation-induced arrhythmia by blocking the calcium channel. Ku Shen ([symbol: see text] Radix Sophorae Flavescentis) contains matrine and flavones, which act as quinidine to decrease the excitability of the myocardium, prolong the refractory period, and inhibit the ectopic cardiac rhythm. And Dan Shen ([symbol: see text] Radix Salviae Miltiorrhizae) has the action of improving the ischemic state of the myocardium by dilating the coronary vessels. In conclusion, the definite therapeutic effects of Huang Lian Sheng Mai Yin in treating ventricular, atrial and nodal arrhythmia suggests that the prescription is rational and accords with the therapeutic principle of TCM. Except discomfort in the gastric cavity and poor appetite experienced by some patients, there is no toxic or adverse reaction.展开更多
基金supported by the National Natural Science Foundation of China(No.11074273)the ministry of water resources'special funds for scientific research on public causes(No.201301061)
文摘When the synthetic aperture focusing technology （SAFT） is used for the detection of the concrete, the signal-to-noise ratio （SNR） and detection depth are not satisfactory. Therefore, the application of SAFT is usually limited. In this paper, we propose an improved SAFT technique for the detection of concrete based on the pulse compression technique used in the Radar domain. The proposed method first transmits a linear frequency modulation （LFM） signal, and then compresses the echo signal using the matched filtering method, after which a compressed signal with a narrower main lobe and higher SNR is obtained. With our improved SAFT, the compressed signals are manipulated in the imaging process and the image contrast is improved. Results show that the SNR is improved and the imaging resolution is guaranteed compared with the conventional short-pulse method. From theoretical and experimental results, we show that the proposed method can suppress noise and improve imaging contrast, and can also be used to detect multiple defects in concrete.
基金National Natural Science Foundation (30630014, 30570359)The grant of "Key Research Direction-KSCX2-YW-R-088" from Chinese Academy of Sciences~~
文摘In vertebrates, non-lens βγ-crystallins are widely expressed in various tissues and their functions are not well known. The molecular mechanisms of trefoil factors （TFFs）, which involved in mucosal healing and tumorigenesis, have remained elusive. βγ-CAT is a novel multifunctional protein complex of non-lens βγ-crystallin and trefoil factor from frog skin secretions. Here we report that βγ-CAT could induce sustained contraction of isolated rabbit aortic rings in dosage （2-35nmol/L） and endothelium dependent manners （P〈0.01 ）. In addition, in situ immunofluorescence indicated that positive TNF-α signals were mainly detected at the endothelial cell layer of βγ-CAT （25nmol/L） treated rings. Furthermore, βγ-CAT induced primary cultured rabbit thoracic aortic endothelial cells （RAECs） rapidly to release TNF-α. After βγ-CAT （25nmol/L） treated for 10 and 30min, the levels of the endothelial cells released TNF-ct were 34.17±5.10 pg/mL and 98.01±4.67 pg/mL （P〈0.01）, respectively. In conclusion, βγ-CAT could induce sustained contraction of isolated aortic rings, and the contractile effect might be partially explained by the release of TNF-α. These findings will give new insight into understanding the functions and physiological roles of non-lens βγ-crystallins and trefoil factors.
文摘A new type of window called combined window is designed to get higher Ratio of Mainlobe to Sidelobes (RMS) and lower Mainlobe Widening Factor (MWF). Simulation results prove that the new window can solve the contradiction between RMS and MWF better than classic windows.
基金The"13th Five-Year"Equipment Pre-Research Common Technology Fund of China(No.41411010202)the National Natural Science Foundation of China(No.61571113)the Natural Science Foundation of Jiangsu Province(No.BK20160697)
文摘As the core of a digital phased array radar system,a radar signal processing environment is created to measure multitarget range and velocity information. The radar echo signal is achieved by superposing target echo, noise, clutter and jamming signals linearly. Considering that these signals have many types,two typical combinations are selected to construct the multi-target echo signal and the simulated echo signal is used as the input of the signal processing environment. This environment mainly adopts pulse compression,moving target indication and detection technologies to process the echo signal.It is found that the frequency domain method is more desirable for the pulse compression effect than the time domain method,and multi-target range information can be measured from the moving target indication result after using a double delay canceller. A new moving target detecting method is proposed,which can present the positive and negative velocity accurately with the multi-target range and velocity measured simultaneously. Simulation results indicate that the potential targets are detected from the chaotic radar echo signals successfully,and their range and velocity can be figured out correctly in the built radar signal processing environment.
基金National Natural Science Foundation of China(60507001 60477022 06YFGPGX08500)
文摘Proposed is a novel optical pulse compression technique based on high-doped erbium fiber amplifier and standard single-mode fiber(SMF). We used the amplifier with the erbium ion concentration of 6.3×10-3 to amplify a hyperbolic secant pulse from a regeneratively mode-locked fiber laser. The central wavelength, pulsewidth and peak power of the pulse are 1 550 nm, 12.5 ps and 3 mW, respectively. Then the amplified pulse with peak power level corresponding to a higher-order soliton is compressed when it propagates through a 3-km-long single-mode fiber. Studied are the compressed pulses under different pump powers and fiber lengths. The results show that it can get a narrower pulse, and solve the difficulty that pulses at low power can not be compressed directly in the fiber. And the construct is compact.
文摘AIM： To investigate the anti-tumor effect of dendritic cells （DCs） pulsed with hsp70-peptide complexes derived from human hepatocellular carcinoma （HCC） cells on human T cells. METHODS： Hsp70-peptide complexes were purified from human HCC cells with column chromatography using ADP-agarose and DEAE-Sepharose. DCs were derived from peripheral blood mononuclear cells of healthy donors in the presence of human GM-CSF and IL-4. The anti-tumor effect of DCs pulsed with hsp70-peptide complexes on human T-cell was assayed by CTL and enzyme-linked immunospot （ELISPOT） tests. RESULTS： Hsp70-peptide complexes derived from human HCC cells activated phenotypic and functional maturation of DCs. The matured DCs stimulated a high level of autologous T-cell proliferation and type Ⅰ cytokine secretion, and induced HCC-specific cytotoxic T lymphocytes （CTLs）, which specifically killed HCC cells by a MHC class Ⅰ restricted mechanism. CONCLUSION： Hsp70-peptide complexes derived from human HCC cells can serve as a potent tumor antigen source for pulsing DCs, the pulsed DCs are very effective in activating specific T-cell responses against HCC cells. 2005 The WJG Press and Elsevier Inc. All rights reserved
文摘AIM:Portopulmonary hypertension is a serious complication of chronic liver disease.Our aim was to search into the effect of terlipressin on systolic pulmonary artery pressure among cirrhotic patients. METHODS:Twelve patients(6 males and 6 females)with liver cirrhosis were recruited in the study.Arterial blood gas samples were obtained in sitting position at rest.Contrast enhanced echocardiography and measurements of systolic pulmonary artery pressure were performed before and after the intravenous injection of 2 mg terlipressin. RESULTS:Of 12 patients studied,the contrast enhanced echocardiography was positive in 5,and the positive findings in contrast enhanced echocardiography were reversed to normal in two after terlipressin injection.The mean systolic pulmonary artery pressure was 25.5±3.6 mmHg before terlipressin injection,and was 22.5+2.5 mmHg after terlipressin(P=0.003).The systolic pulmonary artery pressure was above 25 mmHg in seven of these 12 patients. After the terlipressin injection,systolic pulmonary artery pressure was<25 mmHg in four of these cases(58.3% vs 25%,P=0.04). CONCLUSION:Terlipressin can decrease the systolic pulmonary artery pressure in patients with liver cirrhosis.
文摘A nonlinear optical loop mirror constructed from step-decreasing-dispersion fiber instead of DDF is used to compress optical pulse.Numerical simulations show that the effect of the proposed method is close to that of the method based on DDF.It not only resolves the difficulty of the making of DDF but also makes the design of the system more convenient.
文摘This paper describes a pulse compressor implementation with DSP for small Time Bandwidth (TB) product Linear Frequency Modulation (LFM) waveform. It contains the digital generation of the LFM waveform and the digital internally Hamming weighted compression filter. Two methods for suppression of time sidelobe of the digital pulse compressor are employed. First, the LFM waveform is modified by using cubic phase pre distortion for reducing the effect of Fresnel ripples in small TB product LFM waveform. Secondly, anti aliasing filter is used before A/D converter for reducing spectrum skirt level of the returned LFM waveform. The parameters of the compression filter implemented with IMSA100 DSP are programmable. The experiments show that the peak time sidelobe level of the digital pulse compressor is less than -32 dB for TB product of 20.
文摘Objective To examine whether the two vascular paracrine/autocrine factors,angiotensin Ⅱ(Ang Ⅱ)and endothelin,participate in the pathogenesis of arterial calcification.Methods Nicotine and vitamin D_3 treated rats were studied.Vascular calcification was confirmed by using Von Kossa staining,measurement of calcium content, ^(45)Ca^(2+)uptake assay and alkaline phosphatase(ALP)activity.The plasma and vascular Ang Ⅱ and endothelin levels were measured by using radioimmunoassay.Angiotensinngen and endothehn mRNA levels were determined by RT- PCR.Results The arterial calcium content,^(45)Ca^(2+)uptake and ALP activity were increased in calcification groups compared with control(P<0.01).Administration of the angiotensin receptor antagonist losartan,the endothelin receptor antagonist bosentan,and the angiotensin-converting enzyme inhibitor captopril reduced significantly the arterial calcium content,^(45)Ca^(2+)uptake and ALP activity.In addition,the plasma and aortic Ang Ⅱ and endothelin contents,and vascular angiotensinngen and endothelin mRNA expression were significantly up-regulated(P<0.05). Conclusions These findings suggest that functional renin-angiotensin system and endothelin pathway are involved in vascular calcification,and that activation of these systems could potentiate pathogenesis of arterial calcification.(J Geriatr Cardiol 2004;1(2):108-113.)
文摘The previous experimental studies have demonstrated that addition of Huang Qi ([symbol: see text] Radix Astragali) to the formulated recipe Sheng Mai Yin ([symbol: see text] Decoction for Pulse-activation) exerts the effects of strengthening the myodynamia, increasing the coronary flow, improving myocardial metabolism, and resisting the arrhythmia. The active component of Huang Lian ([symbol: see text] Rhizoma Coptidis) can prolong the myocardial action potential and antagonize the chloroform-, aconitine-, barium chloride-, epinephrine- or coronary ligation-induced arrhythmia by blocking the calcium channel. Ku Shen ([symbol: see text] Radix Sophorae Flavescentis) contains matrine and flavones, which act as quinidine to decrease the excitability of the myocardium, prolong the refractory period, and inhibit the ectopic cardiac rhythm. And Dan Shen ([symbol: see text] Radix Salviae Miltiorrhizae) has the action of improving the ischemic state of the myocardium by dilating the coronary vessels. In conclusion, the definite therapeutic effects of Huang Lian Sheng Mai Yin in treating ventricular, atrial and nodal arrhythmia suggests that the prescription is rational and accords with the therapeutic principle of TCM. Except discomfort in the gastric cavity and poor appetite experienced by some patients, there is no toxic or adverse reaction.
