Charge transport characteristics of Cd_（0.95）Mn_（0.05）Te：In radiation detectors have been evaluated by combining time resolved current transient measurements with time of flight charge transient measurements.The ...Charge transport characteristics of Cd_（0.95）Mn_（0.05）Te：In radiation detectors have been evaluated by combining time resolved current transient measurements with time of flight charge transient measurements.The shapes of the measured current pulses have been interpreted with respect to a concentration of net positive space-charge, which has resulted in an electric field gradient across the detector bulk.From the recorded current pulses the charge collection efficiency of the detector was found to approach 100%.From the evolution of the charge collection efficiency with applied bias,the electron mobility-lifetime product ofμ_nτ_n =（8.5±0.4）×10^（-4） cm^2/V has been estimated.The electron transit time was determined using both transient current technique and time of flight measurements in the bias range of 100-1900 V.From the dependence of drift velocity on applied electric field the electron mobility was found to beμ_n =（718±55） cm^2/（V·s） at room temperature.展开更多
Acutely isolated mouse hippocampal CA3 pyramidal neurons were exposed to 3 mT static magnetic field,and the characteristics of transient outward K+ channel were studied using the whole-cell patch-clamp technique.The e...Acutely isolated mouse hippocampal CA3 pyramidal neurons were exposed to 3 mT static magnetic field,and the characteristics of transient outward K+ channel were studied using the whole-cell patch-clamp technique.The experiment revealed that the amplitude of transient outward potassium channel current was reduced.The maximum activated current densities of control group and exposure group were 163.62±20.68 pA/pF and 98.74±16.57 pA/pF(n=12,P<0.01) respectively.The static magnetic field exposure affected the activation and inactivation process of transient outward potassium channel current.Due to the magnetic field exposure,the half-activation voltage of the activation curves changed from 5.59±1.96 mV to 27.87±7.24 mV(n=12,P<0.05) ,and the slope factor changed from 19.43±2.11 mV to 25.87±4.22 mV(n=12,P<0.05) .The half-inactivation voltage of the inactivation curves also changed from-56.09±0.89 mV to-57.16±1.10 mV(n=12,P>0.05) and the slope factor of the inactivation curves from 8.69±0.80 mV to 10.87±1.02 mV(n=12,P<0.05) .The results show that the static magnetic field can change the characteristics of transient outward K+ channel,and affect the physiological functions of neurons.展开更多
Using the whole cell patch clamp technique, the effect of Cu^2＋on transient outward K^＋current （/to） and delayed rectifier K^＋ current （Idr） was studied in acutely isolated rat hippocampal neurons.Ito and Idr w...Using the whole cell patch clamp technique, the effect of Cu^2＋on transient outward K^＋current （/to） and delayed rectifier K^＋ current （Idr） was studied in acutely isolated rat hippocampal neurons.Ito and Idr were increased when the concentration of Cu^2＋ was lower than 2 × 10^-5 and 10^-5 tool/L, respectively, and increased ratio was decreased with increasing Cu^2＋concentration in the bath solutions. When the concentration continued to increase to 5× 10^-5 and 2 × 10^- 5 mol/L, the currents were hardly changed, while the concentration was more than 10^-4 and 5 × 10^-5 mol/L, the currents were inhibited remarkably. Cu^2＋ （10^-5 mol/L） did not affect the activation and inactivation process of Ito. The activation curve of Idr was shifted toward positive potential, but 10^-5 mol/L Cu^2＋did not affect slope factor. According to these results, it was considered that Cu^2＋at low concentration in the bath solution could promote Ito and Idr while at high concentration could inhibit them, and change of amplitude was different with different membrane voltage. Conclusion was drawn： Cu^2＋may be involved in the pathophysiologic mechanism of diseases with neuropathological components.展开更多
目的探讨糖尿病对大鼠心室肌细胞动作电位(AP)和瞬时外向钾电流(Ito)的影响。方法通过链脲佐菌素诱导糖尿病大鼠模型,双酶法急性分离出对照组和糖尿病组心室肌细胞,全细胞膜片钳技术分别观察心肌细胞AP和Ito电流密度变化以及Ito动力学...目的探讨糖尿病对大鼠心室肌细胞动作电位(AP)和瞬时外向钾电流(Ito)的影响。方法通过链脲佐菌素诱导糖尿病大鼠模型,双酶法急性分离出对照组和糖尿病组心室肌细胞,全细胞膜片钳技术分别观察心肌细胞AP和Ito电流密度变化以及Ito动力学改变。结果与对照组比较,糖尿病组心肌细胞AP形态明显增宽,AP复极20%、50%和90%的时程均明显延长(64.3±7.5 ms vs 29.7±9.2 ms;174.3±6.8 ms vs 98.9±4.2 ms;276.7±8.3 ms vs 173.7±7.2 ms,P均<0.01,n=12);在钳制电位为+50mV时,与对照组比较,糖尿病组心肌细胞Ito的电流密度显著降低(11.51±1.37 pA/pF vs 17.43±1.98 pA/pF,P<0.05,n=12);与对照组比较,糖尿病组心肌细胞Ito的I-V曲线明显下移;失活曲线显著左移(P<0.01,n=12);失活恢复曲线明显减慢。结论糖尿病引起了心肌细胞AP时程延长,Ito幅度降低,并使Ito的失活加快以及失活后恢复减慢。展开更多
The polarization effect introduced by electric field deformation is the most important bottleneck of CdZnTe detector in x-ray imaging. Currently, most of studies focus on electric field deformation caused by trapped c...The polarization effect introduced by electric field deformation is the most important bottleneck of CdZnTe detector in x-ray imaging. Currently, most of studies focus on electric field deformation caused by trapped carriers;the perturbation of electric field due to drifting carriers has been rarely reported. In this study, the effect of transient space-charge perturbation on carrier transport in a CdZnTe semiconductor is evaluated by using the laser-beam-induced current(LBIC) technique.Cusps appear in the current curves of CdZnTe detectors with different carrier transport performances under intense excitation, indicating the deformation of electric field. The current signals under different excitations are compared. The results suggest that with the increase of excitation, the amplitude of cusp increases and the electron transient time gradually decreases. The distortion in electric field is independent of carrier transport performance of detector. Transient space-charge perturbation is responsible for the pulse shape and affects the carrier transport process.展开更多
基金supported in part by the Cooperative Research Centre for Biomedical Imaging Development
文摘Charge transport characteristics of Cd_（0.95）Mn_（0.05）Te：In radiation detectors have been evaluated by combining time resolved current transient measurements with time of flight charge transient measurements.The shapes of the measured current pulses have been interpreted with respect to a concentration of net positive space-charge, which has resulted in an electric field gradient across the detector bulk.From the recorded current pulses the charge collection efficiency of the detector was found to approach 100%.From the evolution of the charge collection efficiency with applied bias,the electron mobility-lifetime product ofμ_nτ_n =（8.5±0.4）×10^（-4） cm^2/V has been estimated.The electron transit time was determined using both transient current technique and time of flight measurements in the bias range of 100-1900 V.From the dependence of drift velocity on applied electric field the electron mobility was found to beμ_n =（718±55） cm^2/（V·s） at room temperature.
基金Supported by National Natural Science Foundation of China(No. 60674111)
文摘Acutely isolated mouse hippocampal CA3 pyramidal neurons were exposed to 3 mT static magnetic field,and the characteristics of transient outward K+ channel were studied using the whole-cell patch-clamp technique.The experiment revealed that the amplitude of transient outward potassium channel current was reduced.The maximum activated current densities of control group and exposure group were 163.62±20.68 pA/pF and 98.74±16.57 pA/pF(n=12,P<0.01) respectively.The static magnetic field exposure affected the activation and inactivation process of transient outward potassium channel current.Due to the magnetic field exposure,the half-activation voltage of the activation curves changed from 5.59±1.96 mV to 27.87±7.24 mV(n=12,P<0.05) ,and the slope factor changed from 19.43±2.11 mV to 25.87±4.22 mV(n=12,P<0.05) .The half-inactivation voltage of the inactivation curves also changed from-56.09±0.89 mV to-57.16±1.10 mV(n=12,P>0.05) and the slope factor of the inactivation curves from 8.69±0.80 mV to 10.87±1.02 mV(n=12,P<0.05) .The results show that the static magnetic field can change the characteristics of transient outward K+ channel,and affect the physiological functions of neurons.
基金Project supported by the National Natural Science Foundation of China （No. 30470408）.
文摘Using the whole cell patch clamp technique, the effect of Cu^2＋on transient outward K^＋current （/to） and delayed rectifier K^＋ current （Idr） was studied in acutely isolated rat hippocampal neurons.Ito and Idr were increased when the concentration of Cu^2＋ was lower than 2 × 10^-5 and 10^-5 tool/L, respectively, and increased ratio was decreased with increasing Cu^2＋concentration in the bath solutions. When the concentration continued to increase to 5× 10^-5 and 2 × 10^- 5 mol/L, the currents were hardly changed, while the concentration was more than 10^-4 and 5 × 10^-5 mol/L, the currents were inhibited remarkably. Cu^2＋ （10^-5 mol/L） did not affect the activation and inactivation process of Ito. The activation curve of Idr was shifted toward positive potential, but 10^-5 mol/L Cu^2＋did not affect slope factor. According to these results, it was considered that Cu^2＋at low concentration in the bath solution could promote Ito and Idr while at high concentration could inhibit them, and change of amplitude was different with different membrane voltage. Conclusion was drawn： Cu^2＋may be involved in the pathophysiologic mechanism of diseases with neuropathological components.
文摘目的探讨糖尿病对大鼠心室肌细胞动作电位(AP)和瞬时外向钾电流(Ito)的影响。方法通过链脲佐菌素诱导糖尿病大鼠模型,双酶法急性分离出对照组和糖尿病组心室肌细胞,全细胞膜片钳技术分别观察心肌细胞AP和Ito电流密度变化以及Ito动力学改变。结果与对照组比较,糖尿病组心肌细胞AP形态明显增宽,AP复极20%、50%和90%的时程均明显延长(64.3±7.5 ms vs 29.7±9.2 ms;174.3±6.8 ms vs 98.9±4.2 ms;276.7±8.3 ms vs 173.7±7.2 ms,P均<0.01,n=12);在钳制电位为+50mV时,与对照组比较,糖尿病组心肌细胞Ito的电流密度显著降低(11.51±1.37 pA/pF vs 17.43±1.98 pA/pF,P<0.05,n=12);与对照组比较,糖尿病组心肌细胞Ito的I-V曲线明显下移;失活曲线显著左移(P<0.01,n=12);失活恢复曲线明显减慢。结论糖尿病引起了心肌细胞AP时程延长,Ito幅度降低,并使Ito的失活加快以及失活后恢复减慢。
基金Project supported by the National Natural Science Foundation of China(Grant No.61874089)the Fund of MIIT(Grant No.MJ-2017-F-05)+2 种基金the 111 Project of China(Grant No.B08040)the NPU Foundation for Fundamental Research,Chinathe Research Found of the State Key Laboratory of Solidification Processing(NWPU),China
文摘The polarization effect introduced by electric field deformation is the most important bottleneck of CdZnTe detector in x-ray imaging. Currently, most of studies focus on electric field deformation caused by trapped carriers;the perturbation of electric field due to drifting carriers has been rarely reported. In this study, the effect of transient space-charge perturbation on carrier transport in a CdZnTe semiconductor is evaluated by using the laser-beam-induced current(LBIC) technique.Cusps appear in the current curves of CdZnTe detectors with different carrier transport performances under intense excitation, indicating the deformation of electric field. The current signals under different excitations are compared. The results suggest that with the increase of excitation, the amplitude of cusp increases and the electron transient time gradually decreases. The distortion in electric field is independent of carrier transport performance of detector. Transient space-charge perturbation is responsible for the pulse shape and affects the carrier transport process.
