阿尔茨海默病(Alzheimer's disease,AD)是老年人中最常见的痴呆类型,往往伴随着很多痴呆的精神与行为症状(behavioral and psychological symptoms of dementia,BPSD)。近年来,不同类型的无创性脑刺激(noninvasive brain stimulatio...阿尔茨海默病(Alzheimer's disease,AD)是老年人中最常见的痴呆类型,往往伴随着很多痴呆的精神与行为症状(behavioral and psychological symptoms of dementia,BPSD)。近年来,不同类型的无创性脑刺激(noninvasive brain stimulation,NIBS)技术被广泛用于AD患者的治疗,先前大量的研究表明,经颅直流电刺激(transcranial direct current stimulation,tDCS)和重复经颅磁刺激(repetitive transcranial magnetic stimulation,rTMS)都能显著改善AD患者的认知功能。然而,关于NIBS对AD患者BPSD治疗的研究相对较少,结果仍然存在争议。本文就tDCS和rTMS对AD患者BPSD治疗的研究进展做综述。展开更多
To explore the influence of compound bioelectret material′s dielectric property on the cell growth,several kinds of compound bioelectret materials of collagen/chitosan were developed Their TSDC(thermally stimulated ...To explore the influence of compound bioelectret material′s dielectric property on the cell growth,several kinds of compound bioelectret materials of collagen/chitosan were developed Their TSDC(thermally stimulated depolarization current)spectra were analyzed,and the compound bioelectret collagen/chitosan whose t α and I α were 37℃ and 2×10 -9 A respectively at polarized state was selected The cell culture study showed that the compound bioelectret material could promote normal cell growth when singly negatively polarized,and could inhibit cancer cell growth when singly positively polarized It proves that the rational designation of compound bioelectret has a broad application for clinical medicine展开更多
Objective Cervical spinal cord stimulation （SCS） has been found to augment cerebral blood flow （CBF） in a number of animal models. However, the effective use of SCS is hampered by a lack of understanding of its me...Objective Cervical spinal cord stimulation （SCS） has been found to augment cerebral blood flow （CBF） in a number of animal models. However, the effective use of SCS is hampered by a lack of understanding of its mechanism（s） of action. In this paper, we focus on the sympathetic and parasympathetic effects of SCS on CBF. Method SpragueDawley rats were selected for the experimental series. The animals were divided into 5 groups to underwent SCS and laser Doppler flowmeter （LDF） recordings. Control group, the animal underwent SCS and LDF recordings without any surgery of the nerve fibers and ganglia. V 1 group, the animal underwent bilateral resection of the nasociliary and post-ganglionic parasympathetic nerve fibbers. SCG group, the animal underwent bilateral resection of supper cervical ganglion. V 1 ＋ SCG group, the animal underwent both surgeries as V1- and SCG-group animals did. Sham group, the animal underwent the carotid manipulation with blunt-tipped forceps as well as the dissection of nasociliary and post-ganglionic parasympathetic nerve fibers around the ethmoidal foramen, but without cutting any nerves. Results During the SCS, the LDF was no statistical difference between the V 1 or SCG group and the control group. Yet, the effects of SCS on CBF are completely abolished in V1＋ SCG group. Conclusions Surgical interruption of both the parasympathetic and sympathetic pathways has the contradict effect on SCS-induced CBF augmentation.展开更多
In this paper, we propose a new model of weighted small-world biological neural networks based on biophysical Hodgkin-Huxley neurons with side-restrain mechanism. Then we study excitement properties of the model under...In this paper, we propose a new model of weighted small-world biological neural networks based on biophysical Hodgkin-Huxley neurons with side-restrain mechanism. Then we study excitement properties of the model under alternating current （AC） stimulation. The study shows that the excitement properties in the networks are preferably consistent with the behavior properties of a brain nervous system under different AC stimuli, such as refractory period and the brain neural excitement response induced by different intensities of noise and coupling. The results of the study have reference worthiness for the brain nerve electrophysiology and epistemological science.展开更多
Overmodulation is frequently required during the transient interval at high speed operations of IPMSMs （interior permanent magnet synchronous motors）. In this work, an overmodulation method is developed in the synch...Overmodulation is frequently required during the transient interval at high speed operations of IPMSMs （interior permanent magnet synchronous motors）. In this work, an overmodulation method is developed in the synchronous reference frame with a provision of assigning different priorities to d- and q-axes currents. During the current boosting in motoring, the d-axis current is increased by priority for a fast current response, and to minimize the overmodulation period. However in the regeneration process, the q-axis current is decreased by priority during a load reduction. Simulation and experimental results show that the proposed method, compared with the existing minimum-phase error method, is better for a fast current response, and in shortening the overmodulation period.展开更多
1.促进作物增产据试验,对某些作物采用电激处理,能加速作物的新陈代谢,明显提高其产量。用220伏交流电刺激黄瓜,可使光合作用增强1倍,生长周期明显缩短,如在结瓜期使用90伏电压,可使产量提高3倍。用220伏电压处理番茄种子,可使果实维生...1.促进作物增产据试验,对某些作物采用电激处理,能加速作物的新陈代谢,明显提高其产量。用220伏交流电刺激黄瓜,可使光合作用增强1倍,生长周期明显缩短,如在结瓜期使用90伏电压,可使产量提高3倍。用220伏电压处理番茄种子,可使果实维生素 C 含量增加7%,糖分增加1.2%,产量增加17%。展开更多
As the key protection device in the power system, the ageing characteristics of ZnO varistor can directly affect the safe operation of power system. In order to study the influence of Co2O3 content on the electrical p...As the key protection device in the power system, the ageing characteristics of ZnO varistor can directly affect the safe operation of power system. In order to study the influence of Co2O3 content on the electrical properties of ZnO varistors, thermally stimulated current (TSC) characteristics test, capacitance-voltage (C-V) characteristics test, scanning electron microscope (SEM) test, voltage-current (V-I) test were carried out on ZnO varistors before and after AC ageing tests. The results show that the mean grain size decreases while the varistor voltage increases as the Co2O3 content increases, the barrier height and the defects of ZnO varistors increase with the increase of Co2O3 content, and the barrier height decreases at a certain degree after AC ageing test. As the Co2+ ion radius is close to that of Zn2+ ion, it is easy for Co2+ ions to enter into ZnO lattice during sintering process, which is account for the increase of zinc interstitial of ZnO varistors. When the Co2O3 content exceeds a certain range, the AC degradation degree of ZnO varistors will become much more serious. From the experimental results, ZnO varistors doped with 1.0 mol% Co2 O3 exhibit a better performance.展开更多
Objective:To investigate the relationship between the temperature and the microvascular blood flow of the cerebral cortex, and the influence of electro-acupuncture (EA) on the cortical microcirculation. Methods: High ...Objective:To investigate the relationship between the temperature and the microvascular blood flow of the cerebral cortex, and the influence of electro-acupuncture (EA) on the cortical microcirculation. Methods: High temperature spots on the anterior ectosylvian and low temperature spots on the posterior suprasylvian on the cortical surface of 20 cats were identified using cortical infrared thermography (CIT); the blood flow in the microcirculation on these spots was measured with laser-Doppler flowmetry. EA was given at Zusanli (ST 36) and changes in the blood flow in the cerebral cortex microcirculation were detected. Results: 1) The mean temperatures on the high (34.83±0.24°C) and low (32.28±0.27°C) temperature spots were significantly different (P<0.001); this was indicative of a temperature difference on the cortical surface; 2) The average blood flow in the microcirculation of the high (266.8±19.2 PU) and low (140.8±9.9 PU) temperature spots was significantly different (P<0.001). 3) On the cortical high temperature spots, the mean blood flow in the microcirculation significantly increased from 266.8±86.8 PU before EA, to 422.5±47.4 PU following 5 minutes of EA (58.35%; P<0.01), and 431.8±52.8 PU 5 minutes after ceasing EA (61.84%; P<0.01). 4) On the low temperature spots, there were no significant differences in blood flow following 5 minutes of EA (146.3±11.5 PU), and 5 minutes after ceasing EA (140.5±11.6 PU), when compared with that before acupuncture (140.8±9.9 PU; P>0.9). Conclusion: The high temperature spots of the cortex are active functional regions of neurons with higher blood flow and a stronger response to EA. EA induces a significant increase in blood flow in the high temperature spots of the cortex.展开更多
Purpose： In order to explore the clinical mechanism of Neiguan （PC 6） in the treatment of acute seizure of migraine and the relationship between Neiguan （PC 6） and cerebral blood flow. Methods： Clinically, 30 ca...Purpose： In order to explore the clinical mechanism of Neiguan （PC 6） in the treatment of acute seizure of migraine and the relationship between Neiguan （PC 6） and cerebral blood flow. Methods： Clinically, 30 cases of the patients with acute seizure of migraine （ascending phase） were selected, in TCD abnormality, and divided randomly into the treatment group and control group, 15 cases in each group. In acute seizure of migraine, Neiguan （PC 6） was punctured with electric stimulation on the healthy side of the patients in the treatment group and Xuehai （SP 10） was punctured with electric stimulation on the healthy side of the patients in the control group. TCD was determined in the patients 30 min before and after the treatment. Results and conclusion： After transdermal electric stimulation on Neiguan （PC 6）, the velocity of intracranial blood flow was obviously slowed down, indicating that transdermal electric stimulation on Neiguan （PC 6） can effectively relieve the spasm of intracranial blood vessels and also shows its relative specificity.展开更多
文摘阿尔茨海默病(Alzheimer's disease,AD)是老年人中最常见的痴呆类型,往往伴随着很多痴呆的精神与行为症状(behavioral and psychological symptoms of dementia,BPSD)。近年来,不同类型的无创性脑刺激(noninvasive brain stimulation,NIBS)技术被广泛用于AD患者的治疗,先前大量的研究表明,经颅直流电刺激(transcranial direct current stimulation,tDCS)和重复经颅磁刺激(repetitive transcranial magnetic stimulation,rTMS)都能显著改善AD患者的认知功能。然而,关于NIBS对AD患者BPSD治疗的研究相对较少,结果仍然存在争议。本文就tDCS和rTMS对AD患者BPSD治疗的研究进展做综述。
文摘To explore the influence of compound bioelectret material′s dielectric property on the cell growth,several kinds of compound bioelectret materials of collagen/chitosan were developed Their TSDC(thermally stimulated depolarization current)spectra were analyzed,and the compound bioelectret collagen/chitosan whose t α and I α were 37℃ and 2×10 -9 A respectively at polarized state was selected The cell culture study showed that the compound bioelectret material could promote normal cell growth when singly negatively polarized,and could inhibit cancer cell growth when singly positively polarized It proves that the rational designation of compound bioelectret has a broad application for clinical medicine
文摘Objective Cervical spinal cord stimulation （SCS） has been found to augment cerebral blood flow （CBF） in a number of animal models. However, the effective use of SCS is hampered by a lack of understanding of its mechanism（s） of action. In this paper, we focus on the sympathetic and parasympathetic effects of SCS on CBF. Method SpragueDawley rats were selected for the experimental series. The animals were divided into 5 groups to underwent SCS and laser Doppler flowmeter （LDF） recordings. Control group, the animal underwent SCS and LDF recordings without any surgery of the nerve fibers and ganglia. V 1 group, the animal underwent bilateral resection of the nasociliary and post-ganglionic parasympathetic nerve fibbers. SCG group, the animal underwent bilateral resection of supper cervical ganglion. V 1 ＋ SCG group, the animal underwent both surgeries as V1- and SCG-group animals did. Sham group, the animal underwent the carotid manipulation with blunt-tipped forceps as well as the dissection of nasociliary and post-ganglionic parasympathetic nerve fibers around the ethmoidal foramen, but without cutting any nerves. Results During the SCS, the LDF was no statistical difference between the V 1 or SCG group and the control group. Yet, the effects of SCS on CBF are completely abolished in V1＋ SCG group. Conclusions Surgical interruption of both the parasympathetic and sympathetic pathways has the contradict effect on SCS-induced CBF augmentation.
基金The project supported by National Natural Science Foundation of China under Grant Nos. 70571017 and 10547004 and the Key Projects of National Natural Science Foundation of China under Grant No. 70431002
文摘In this paper, we propose a new model of weighted small-world biological neural networks based on biophysical Hodgkin-Huxley neurons with side-restrain mechanism. Then we study excitement properties of the model under alternating current （AC） stimulation. The study shows that the excitement properties in the networks are preferably consistent with the behavior properties of a brain nervous system under different AC stimuli, such as refractory period and the brain neural excitement response induced by different intensities of noise and coupling. The results of the study have reference worthiness for the brain nerve electrophysiology and epistemological science.
文摘Overmodulation is frequently required during the transient interval at high speed operations of IPMSMs （interior permanent magnet synchronous motors）. In this work, an overmodulation method is developed in the synchronous reference frame with a provision of assigning different priorities to d- and q-axes currents. During the current boosting in motoring, the d-axis current is increased by priority for a fast current response, and to minimize the overmodulation period. However in the regeneration process, the q-axis current is decreased by priority during a load reduction. Simulation and experimental results show that the proposed method, compared with the existing minimum-phase error method, is better for a fast current response, and in shortening the overmodulation period.
基金supported by the National Natural Science Foundation of China (Grant No. 50577021)the Doctoral Program Foundation of Institutions of Higher Education of China (Grant No. 200800790004)
文摘As the key protection device in the power system, the ageing characteristics of ZnO varistor can directly affect the safe operation of power system. In order to study the influence of Co2O3 content on the electrical properties of ZnO varistors, thermally stimulated current (TSC) characteristics test, capacitance-voltage (C-V) characteristics test, scanning electron microscope (SEM) test, voltage-current (V-I) test were carried out on ZnO varistors before and after AC ageing tests. The results show that the mean grain size decreases while the varistor voltage increases as the Co2O3 content increases, the barrier height and the defects of ZnO varistors increase with the increase of Co2O3 content, and the barrier height decreases at a certain degree after AC ageing test. As the Co2+ ion radius is close to that of Zn2+ ion, it is easy for Co2+ ions to enter into ZnO lattice during sintering process, which is account for the increase of zinc interstitial of ZnO varistors. When the Co2O3 content exceeds a certain range, the AC degradation degree of ZnO varistors will become much more serious. From the experimental results, ZnO varistors doped with 1.0 mol% Co2 O3 exhibit a better performance.
基金supported by a grant from the National Natural Science Fund of China (No. 39770925)Science Research Fund of The Ministry of Personnel for Excellent Returnees (1998)Beijing Key Laboratory Fund of The Science and Technology Commission of Beijing (951890600)
文摘Objective:To investigate the relationship between the temperature and the microvascular blood flow of the cerebral cortex, and the influence of electro-acupuncture (EA) on the cortical microcirculation. Methods: High temperature spots on the anterior ectosylvian and low temperature spots on the posterior suprasylvian on the cortical surface of 20 cats were identified using cortical infrared thermography (CIT); the blood flow in the microcirculation on these spots was measured with laser-Doppler flowmetry. EA was given at Zusanli (ST 36) and changes in the blood flow in the cerebral cortex microcirculation were detected. Results: 1) The mean temperatures on the high (34.83±0.24°C) and low (32.28±0.27°C) temperature spots were significantly different (P<0.001); this was indicative of a temperature difference on the cortical surface; 2) The average blood flow in the microcirculation of the high (266.8±19.2 PU) and low (140.8±9.9 PU) temperature spots was significantly different (P<0.001). 3) On the cortical high temperature spots, the mean blood flow in the microcirculation significantly increased from 266.8±86.8 PU before EA, to 422.5±47.4 PU following 5 minutes of EA (58.35%; P<0.01), and 431.8±52.8 PU 5 minutes after ceasing EA (61.84%; P<0.01). 4) On the low temperature spots, there were no significant differences in blood flow following 5 minutes of EA (146.3±11.5 PU), and 5 minutes after ceasing EA (140.5±11.6 PU), when compared with that before acupuncture (140.8±9.9 PU; P>0.9). Conclusion: The high temperature spots of the cortex are active functional regions of neurons with higher blood flow and a stronger response to EA. EA induces a significant increase in blood flow in the high temperature spots of the cortex.
文摘Purpose： In order to explore the clinical mechanism of Neiguan （PC 6） in the treatment of acute seizure of migraine and the relationship between Neiguan （PC 6） and cerebral blood flow. Methods： Clinically, 30 cases of the patients with acute seizure of migraine （ascending phase） were selected, in TCD abnormality, and divided randomly into the treatment group and control group, 15 cases in each group. In acute seizure of migraine, Neiguan （PC 6） was punctured with electric stimulation on the healthy side of the patients in the treatment group and Xuehai （SP 10） was punctured with electric stimulation on the healthy side of the patients in the control group. TCD was determined in the patients 30 min before and after the treatment. Results and conclusion： After transdermal electric stimulation on Neiguan （PC 6）, the velocity of intracranial blood flow was obviously slowed down, indicating that transdermal electric stimulation on Neiguan （PC 6） can effectively relieve the spasm of intracranial blood vessels and also shows its relative specificity.
