延迟整流钾通道 (IK)主要参与心肌动作电位的复极过程。其至少包含两种成分 :快速激活成分 (Ikr)和缓慢激活成分 (Iks)。目前 IK 通道的分子基础已趋阐明 ,HERG,Kv L QT1 或 min K基因突变均可抑制 IK 流 (Ikr或 Iks) ,导致心肌复极延...延迟整流钾通道 (IK)主要参与心肌动作电位的复极过程。其至少包含两种成分 :快速激活成分 (Ikr)和缓慢激活成分 (Iks)。目前 IK 通道的分子基础已趋阐明 ,HERG,Kv L QT1 或 min K基因突变均可抑制 IK 流 (Ikr或 Iks) ,导致心肌复极延长 ,最终可产生 QT延长综合征 (L QTS)展开更多
Aiming at the application of a wireless sensor network to locating miners in underground mine,we design a wireless sensor network location node system,considering the communication performance and the intrinsic safety...Aiming at the application of a wireless sensor network to locating miners in underground mine,we design a wireless sensor network location node system,considering the communication performance and the intrinsic safety. The location node system consists of a mobile node,several fixed nodes,and a sink node,all of whose circuits were designed based on CC2430. A varistor and a RC circuit were used in the reset circuit of a sensor node to guarantee the intrinsic safety by reducing discharge energy,the theoretical analysis of the discharge energy shows that the reset circuit is an intrinsic safety one. The analysis and simulation about the performance of the location node system are discussed,such as network communication delay and packet loss rate,the results show that the highest network communication delay of the system is about 0.11 seconds,and the highest packet loss rate is about 0.13,which assures the location node system has a high reliability,and can locate miners in the underground mine.展开更多
A rectangle capacity patch was adopted as the resonance unit of the Log Periodic Dipole Antenna (LPDA) so as to realize the miniaturization of this aerial in this paper. Fifteen rectangle capacity patch units of diffe...A rectangle capacity patch was adopted as the resonance unit of the Log Periodic Dipole Antenna (LPDA) so as to realize the miniaturization of this aerial in this paper. Fifteen rectangle capacity patch units of different parameters were analyzed in this paper and three design laws of size-reduction were found. Accord-ing to these design laws, a 70% miniaturization ratio LPDA was designed and fabricated. The Voltage Standing Wave Ratio (VSWR) and pattern of the fabricated LPDA were measured. The results indicate that this size-reduction method do not deteriorate performance.展开更多
This paper presents an innovative switched-mode auto gain control （AGC） circuit with internally created reset module for DC-10Mb/s burst-mode unbalanced （BMU） optical data transmission. Conventional AGC circuit is...This paper presents an innovative switched-mode auto gain control （AGC） circuit with internally created reset module for DC-10Mb/s burst-mode unbalanced （BMU） optical data transmission. Conventional AGC circuit is inappropriate for BMU data transmission because it is based on average level detection and requires considerable time to settle on a predefined gain. Therefore, we adopt a fast switched-mode AGC based on peak level detection. After the gain is adjusted, the peak level detectors need to re-detect the peak level of the input signal. Thus, we develop an internally created reset module. This AGC with reset module exhibits a fast operation and achieves an adjusted stable gain within one-bit, avoiding any bit loss up to 10Mb/s data rate. During power-up, the peak level detectors possibly hold an uncertain level resulting in the bit-errors. We propose a power-up reset circuit to solve this problem. Designed in a 0.5μm CMOS technology, the circuit achieves an optical sensitivity of better than -30dBm and a wide dynamic range of over 30dB with a power dissipation of only 30 mW from a 5V supply.展开更多
Action potentials generated in the sinoatrial node （SAN） dominate the rhythm and rate of a healthy human heart. Subsequently, these action potentials propagate to the whole heart via its conduction system. Abnormali...Action potentials generated in the sinoatrial node （SAN） dominate the rhythm and rate of a healthy human heart. Subsequently, these action potentials propagate to the whole heart via its conduction system. Abnormalities of impulse generation and/or propagation in a heart can cause arrhythmias. For example, SAN dysfunction or conduction block of the atrioventricular node can lead to serious bradycardia which is currently treated with an implanted electronic pacemaker. On the other hand, conduction damage may cause reentrant tachyarrhythmias which are primarily treated pharmacologically or by medical device-based therapies, including defibrillation and tissue ablation. However, drug therapies sometimes may not be effective or are associated with serious side effects. Device-based therapies for cardiac arrhythmias, even with well developed technology, still face inadequacies, limitations, hardware complications, and other challenges. Therefore, scientists are actively seeking other alternatives for antiarrhythmic therapy. In particular, cells and genes used for repairing cardiac conduction damage/defect have been investigated in various studies both in vitro and in vivo. Despite the complexities of the excitation and conduction systems of the heart, cell and gene-based strategies provide novel alternatives for treatment or cure of cardiac arrhythmias. This review summarizes some highlights of recent research progress in this field.展开更多
Objective: To assess the outcome of valve replacement under mild hypothermia on pump-beating heart and to discuss the risk factors of cardiac valve surgery. Methods: In the period from November 1997 to May 2003, a tot...Objective: To assess the outcome of valve replacement under mild hypothermia on pump-beating heart and to discuss the risk factors of cardiac valve surgery. Methods: In the period from November 1997 to May 2003, a total of 800 cases of valve replacement were carried out in our institute. The clinical data were reviewed and the technique of mild hypothermia and pump-beating heart to replace cardiac valve was described in detail. Results: 800 patients, 308 male and 492 female, with age range from 8 to 66 years, weighing 19 to 88 kg, underwent operation. The average cardiopulmonary bypass time was (109.38± 40.64) min, the average clamping time of the vena cava was (77.87±27.99) min and the average mechanical ventilation time was (17.78±12.21) h. There were 17 patients died in the early postoperative stage with an early mortality rate of 2.13%. The causes of death were failure in the weaning of extracorporeal circulation in 2 cases, severe low output syndrome in 3 cases, ventricular fibrillation in 3 cases, obstruction of coronary ostium of mechanical prosthetic valve in 1 case, hepatic failure in 2 cases, pulmonary failure in 1 case, multiorgan failure in 4 cases, and prosthetic valve dysfunction in 1 case. Severe postopertive complications occurred in 51 cases (6.375%), which included reexploration because of excessive bleeding in 16 cases (2.0%), lavage of poststernal infection in 2 cases (0.25%), postoperative strike in 7 cases (0.875%), pulmonary failure in 5 cases (0.625%), hepatic failure in 4 cases (0.5%), multiorgan failure in 11 cases (1.375%), ventricular arrhythmia in 5 cases (0.625%) and peripheral circulation failure in 1 case (0.125%). Conclusion: Mild hypothermia and pump-beating heart result in satisfying clinical outcome in patients undergoing valve replacement. The integrated sequenced deairing procedure ensures the avoidance of air embolism during operation. Pump-beating heart technique offers a safe and practical option especially in patients with severe critical valvular disorder.展开更多
Presented was an optimum designed CMOS active pixel sensor.In this sensor,used is a PMOSFET substituting for the NMOSFET in traditional sensor as restoration transistor.Compared with traditional active pixel sensor un...Presented was an optimum designed CMOS active pixel sensor.In this sensor,used is a PMOSFET substituting for the NMOSFET in traditional sensor as restoration transistor.Compared with traditional active pixel sensor under the same condition based on 0.25μm CMOS technology,simulating results show that the new structure device has higher signal-to-noise ratio,wider output swing,wider dynamic range and faster readout speed.展开更多
In situ capping is an attractive and cost-effective method for remediation of contaminated sediments,but few studies on enhancing contaminant degradation in sediment caps have been reported,especially for chlorinated ...In situ capping is an attractive and cost-effective method for remediation of contaminated sediments,but few studies on enhancing contaminant degradation in sediment caps have been reported,especially for chlorinated benzenes.Electrically enhanced bioactive barrier is a new process for in situ remediation for reducible compounds in soil or sediments.The primary objective of this study is to determine if electrodes in sediment could create a redox gradient and provide electron acceptor/donor to stimulate degradation of chlorinated contaminant.The results demonstrate that graphite electrodes lead to sustainable evolution of hydrogen,displaying zero-order kinetics in the initial stages with different voltages.The constant rates of hydrogen evolution at 3,4,and 5 V are1.05,2.54,and 4.3 nmol·L 1·d 1,respectively.Even higher voltage can produce more hydrogen,but it could not keep long time because the over potentials on electrode surfaces prevent its function.The study shows that 4 V is more appropriate for hydrogen evolution.The measured and evaluated concentration of 1,2,3,5-tetrachlorobenzene in pore water of sediment and concentration of sulfate show that dechlorination is inhibited at higher concentration of sulfate.展开更多
The feasibility of longer spans relies on the successful implementation of new high-strength light weight materials such as carbon fiber reinforced polymer(CFRP). First, a dimensionless equilibrium equation and the co...The feasibility of longer spans relies on the successful implementation of new high-strength light weight materials such as carbon fiber reinforced polymer(CFRP). First, a dimensionless equilibrium equation and the corresponding compatibility equation are established to develop the cable force equation and cable displacement governing equation for suspension cables, respectively. Subsequently, the inextensible cable case is introduced. The formula of the Irvine parameter is considered and its physical interpretation as well as its relationship with the chord gravity stiffness is presented. The influences on the increment of cable force and displacement by λ2 and load ratio p′ are analyzed, respectively. Based on these assumptions and the analytical formulations, a 2000 m span suspension cable is utilized as an example to verify the proposed formulation and the responses of the relative increment of cable force and cable displacement under symmetrical and asymmetrical loads are studied and presented. In each case, the deflections resulting from elastic elongation or solely due to geometrical displacement are analyzed for the lower elastic modulus CFRP. Finally, in comparison with steel cables, the influences on the cable force equation and the governing displacement equation by span and rise span ratio are analyzed. Moreover, the influences on the static performance of suspension bridge by span and sag ratios are also analyzed. The substantive characteristics of the static performance of super span CFRP suspension bridges are clarified and the superiority and the characteristics of CFRP cable structure are demonstrated analytically.展开更多
基金Projects 20070411065 supported by the China Postdoctoral Science Foundation0801028B by the Jiangsu Postdoctoral Science Research Foundation
文摘Aiming at the application of a wireless sensor network to locating miners in underground mine,we design a wireless sensor network location node system,considering the communication performance and the intrinsic safety. The location node system consists of a mobile node,several fixed nodes,and a sink node,all of whose circuits were designed based on CC2430. A varistor and a RC circuit were used in the reset circuit of a sensor node to guarantee the intrinsic safety by reducing discharge energy,the theoretical analysis of the discharge energy shows that the reset circuit is an intrinsic safety one. The analysis and simulation about the performance of the location node system are discussed,such as network communication delay and packet loss rate,the results show that the highest network communication delay of the system is about 0.11 seconds,and the highest packet loss rate is about 0.13,which assures the location node system has a high reliability,and can locate miners in the underground mine.
文摘A rectangle capacity patch was adopted as the resonance unit of the Log Periodic Dipole Antenna (LPDA) so as to realize the miniaturization of this aerial in this paper. Fifteen rectangle capacity patch units of different parameters were analyzed in this paper and three design laws of size-reduction were found. Accord-ing to these design laws, a 70% miniaturization ratio LPDA was designed and fabricated. The Voltage Standing Wave Ratio (VSWR) and pattern of the fabricated LPDA were measured. The results indicate that this size-reduction method do not deteriorate performance.
基金Supported by the Natural Science Foundation of Jiangsu Province （ BK2010411 ） and the National International Cooperation Project of China-Korea （2011DFA11310）.
文摘This paper presents an innovative switched-mode auto gain control （AGC） circuit with internally created reset module for DC-10Mb/s burst-mode unbalanced （BMU） optical data transmission. Conventional AGC circuit is inappropriate for BMU data transmission because it is based on average level detection and requires considerable time to settle on a predefined gain. Therefore, we adopt a fast switched-mode AGC based on peak level detection. After the gain is adjusted, the peak level detectors need to re-detect the peak level of the input signal. Thus, we develop an internally created reset module. This AGC with reset module exhibits a fast operation and achieves an adjusted stable gain within one-bit, avoiding any bit loss up to 10Mb/s data rate. During power-up, the peak level detectors possibly hold an uncertain level resulting in the bit-errors. We propose a power-up reset circuit to solve this problem. Designed in a 0.5μm CMOS technology, the circuit achieves an optical sensitivity of better than -30dBm and a wide dynamic range of over 30dB with a power dissipation of only 30 mW from a 5V supply.
文摘Action potentials generated in the sinoatrial node （SAN） dominate the rhythm and rate of a healthy human heart. Subsequently, these action potentials propagate to the whole heart via its conduction system. Abnormalities of impulse generation and/or propagation in a heart can cause arrhythmias. For example, SAN dysfunction or conduction block of the atrioventricular node can lead to serious bradycardia which is currently treated with an implanted electronic pacemaker. On the other hand, conduction damage may cause reentrant tachyarrhythmias which are primarily treated pharmacologically or by medical device-based therapies, including defibrillation and tissue ablation. However, drug therapies sometimes may not be effective or are associated with serious side effects. Device-based therapies for cardiac arrhythmias, even with well developed technology, still face inadequacies, limitations, hardware complications, and other challenges. Therefore, scientists are actively seeking other alternatives for antiarrhythmic therapy. In particular, cells and genes used for repairing cardiac conduction damage/defect have been investigated in various studies both in vitro and in vivo. Despite the complexities of the excitation and conduction systems of the heart, cell and gene-based strategies provide novel alternatives for treatment or cure of cardiac arrhythmias. This review summarizes some highlights of recent research progress in this field.
文摘Objective: To assess the outcome of valve replacement under mild hypothermia on pump-beating heart and to discuss the risk factors of cardiac valve surgery. Methods: In the period from November 1997 to May 2003, a total of 800 cases of valve replacement were carried out in our institute. The clinical data were reviewed and the technique of mild hypothermia and pump-beating heart to replace cardiac valve was described in detail. Results: 800 patients, 308 male and 492 female, with age range from 8 to 66 years, weighing 19 to 88 kg, underwent operation. The average cardiopulmonary bypass time was (109.38± 40.64) min, the average clamping time of the vena cava was (77.87±27.99) min and the average mechanical ventilation time was (17.78±12.21) h. There were 17 patients died in the early postoperative stage with an early mortality rate of 2.13%. The causes of death were failure in the weaning of extracorporeal circulation in 2 cases, severe low output syndrome in 3 cases, ventricular fibrillation in 3 cases, obstruction of coronary ostium of mechanical prosthetic valve in 1 case, hepatic failure in 2 cases, pulmonary failure in 1 case, multiorgan failure in 4 cases, and prosthetic valve dysfunction in 1 case. Severe postopertive complications occurred in 51 cases (6.375%), which included reexploration because of excessive bleeding in 16 cases (2.0%), lavage of poststernal infection in 2 cases (0.25%), postoperative strike in 7 cases (0.875%), pulmonary failure in 5 cases (0.625%), hepatic failure in 4 cases (0.5%), multiorgan failure in 11 cases (1.375%), ventricular arrhythmia in 5 cases (0.625%) and peripheral circulation failure in 1 case (0.125%). Conclusion: Mild hypothermia and pump-beating heart result in satisfying clinical outcome in patients undergoing valve replacement. The integrated sequenced deairing procedure ensures the avoidance of air embolism during operation. Pump-beating heart technique offers a safe and practical option especially in patients with severe critical valvular disorder.
基金Hunan Provincial Natural Science Foundation of China(05JJ30115)
文摘Presented was an optimum designed CMOS active pixel sensor.In this sensor,used is a PMOSFET substituting for the NMOSFET in traditional sensor as restoration transistor.Compared with traditional active pixel sensor under the same condition based on 0.25μm CMOS technology,simulating results show that the new structure device has higher signal-to-noise ratio,wider output swing,wider dynamic range and faster readout speed.
基金Supported by the National Natural Science Foundation of China（51108317） the Municipal Natural Science Foundation of Tianjin（12JCQNJC05400）
文摘In situ capping is an attractive and cost-effective method for remediation of contaminated sediments,but few studies on enhancing contaminant degradation in sediment caps have been reported,especially for chlorinated benzenes.Electrically enhanced bioactive barrier is a new process for in situ remediation for reducible compounds in soil or sediments.The primary objective of this study is to determine if electrodes in sediment could create a redox gradient and provide electron acceptor/donor to stimulate degradation of chlorinated contaminant.The results demonstrate that graphite electrodes lead to sustainable evolution of hydrogen,displaying zero-order kinetics in the initial stages with different voltages.The constant rates of hydrogen evolution at 3,4,and 5 V are1.05,2.54,and 4.3 nmol·L 1·d 1,respectively.Even higher voltage can produce more hydrogen,but it could not keep long time because the over potentials on electrode surfaces prevent its function.The study shows that 4 V is more appropriate for hydrogen evolution.The measured and evaluated concentration of 1,2,3,5-tetrachlorobenzene in pore water of sediment and concentration of sulfate show that dechlorination is inhibited at higher concentration of sulfate.
基金Project(2010-K2-8)supported by Science and Technology Program of the Ministry of Housing and Urban Rural Development,ChinaProject supported by the Priority Academic Program Development of Jiangsu Higher Education Institutions,China
文摘The feasibility of longer spans relies on the successful implementation of new high-strength light weight materials such as carbon fiber reinforced polymer(CFRP). First, a dimensionless equilibrium equation and the corresponding compatibility equation are established to develop the cable force equation and cable displacement governing equation for suspension cables, respectively. Subsequently, the inextensible cable case is introduced. The formula of the Irvine parameter is considered and its physical interpretation as well as its relationship with the chord gravity stiffness is presented. The influences on the increment of cable force and displacement by λ2 and load ratio p′ are analyzed, respectively. Based on these assumptions and the analytical formulations, a 2000 m span suspension cable is utilized as an example to verify the proposed formulation and the responses of the relative increment of cable force and cable displacement under symmetrical and asymmetrical loads are studied and presented. In each case, the deflections resulting from elastic elongation or solely due to geometrical displacement are analyzed for the lower elastic modulus CFRP. Finally, in comparison with steel cables, the influences on the cable force equation and the governing displacement equation by span and rise span ratio are analyzed. Moreover, the influences on the static performance of suspension bridge by span and sag ratios are also analyzed. The substantive characteristics of the static performance of super span CFRP suspension bridges are clarified and the superiority and the characteristics of CFRP cable structure are demonstrated analytically.
