Objective:To investigate the clinical effect of ultra-low frequency repetitive transcranial magnetic stimulation on dysphagia in elderly patients with acute cerebral infarction and its impact on quality of life.Method...Objective:To investigate the clinical effect of ultra-low frequency repetitive transcranial magnetic stimulation on dysphagia in elderly patients with acute cerebral infarction and its impact on quality of life.Methods:60 elderly patients with dysphagia caused by acute cerebral infarction were randomly divided into rTMS group and control group,30 cases in each group.Both groups received routine drug therapy and swallowing function training.rTMS group was additionally treated by ultra-low frequency(10mHZ)repetitive transcranial magnetic stimulation for 14 days.The changes of NIHSS score andADL score and NSE serum level and Wa Tian drinking water experiment and Fujishima Ichiro dysphagia scale score and SWAL-QOL score and SF-36 score were observed between the two groups before and after treatment.The clinical effect was evaluated by Wa Tian drinking water experiment.Results:After treatment,The clinical effective rate in rTMS group was significantly higher compared with that in the control group(P<0.05),NIHSS score and serum NSE level were significantly lower compared with the control group(P<0.05),ADL score and Fujishima Ichiro dysphagia score and SWAL-QOL score and SF-36 scores were significantly higher compared with the control group(P<0.05).After treatment,SF-36 total score(or SWAL-QOL Score)was negatively correlated with NSE serum level and NIHSS score,which was positively correlated with ADL score and Fujishima Ichiro dysphagia scale score score.Conclusion:Ultra-low frequency rTMS therapy can reduce NSE level,effectively improve dysphagia in elderly patients with acute cerebral infarction and significantly improve the elderly patients'life quality.展开更多
In our daily lives,low-frequency kinetic energy primarily manifests as vibrations.However,effective harnessing of lowfrequency kinetic energy remains a formidable challenge.This paper proposes a rope-driven rotor that...In our daily lives,low-frequency kinetic energy primarily manifests as vibrations.However,effective harnessing of lowfrequency kinetic energy remains a formidable challenge.This paper proposes a rope-driven rotor that rotates around an axis and consists of an ultra-high-molecular-weight polyethylene(UHMWPE)wire wrapped around a metal shaft.The rotor can convert ultra-low frequency vibration/linear motion into rapid rotation by pressing the top at low frequencies and driving the rope for a quick release.The harvester can generate up to 36.25 m W power using a 0.1-mm-diameter UHMWPE wire as the rotor when periodically pressed down to 20 mm at a frequency of 1 Hz.A simple power generation floor is assembled,generating 28.58-m W power with a matching load at a frequency of 1.5 Hz.Moreover,the harvester can increase the charging voltage of a 0.47-F supercapacitor from 0 to 6.8 V within 10 min.In addition,the harvester can harvest energy through a light finger press motion,and the energy obtained can also support the continuous operation of multiple electronic devices concurrently.This study introduces an effective method for harvesting ultra-low frequency energy and has great prospects in the field of power generation floor and human movement energy harvesting.展开更多
Human motion induced vibration has very low frequency,ranging from 2 Hz to 5 Hz.Traditional vibration isolators are not effective in low-frequency regions due to the trade-off between the low natural frequency and the...Human motion induced vibration has very low frequency,ranging from 2 Hz to 5 Hz.Traditional vibration isolators are not effective in low-frequency regions due to the trade-off between the low natural frequency and the high load capacity.In this paper,inspired by the human spine,we propose a novel bionic human spine inspired quasi-zero stiffness(QZS)vibration isolator which consists of a cascaded multi-stage negative stiffness structure.The force and stiffness characteristics are investigated first,the dynamic model is established by Newton’s second law,and the isolation performance is analyzed by the harmonic balance method(HBM).Numerical results show that the bionic isolator can obtain better low-frequency isolation performance by increasing the number of negative structure stages,and reducing the damping values and external force values can obtain better low-frequency isolation performance.In comparison with the linear structure and existing traditional QZS isolator,the bionic spine isolator has better vibration isolation performance in low-frequency regions.It paves the way for the design of bionic ultra-low-frequency isolators and shows potential in many engineering applications.展开更多
Among electromagnetic methods of short-term earthquake prediction,an approach is being actively developed based on the phenomenon of magnetic ultra-low-frequency(ULF)power depression occurring a few days before an ear...Among electromagnetic methods of short-term earthquake prediction,an approach is being actively developed based on the phenomenon of magnetic ultra-low-frequency(ULF)power depression occurring a few days before an earthquake.In particular,a nighttime geomagnetic power depression in the band 0.03-0.05 Hz was observed approximately 5 days before the catastrophic Tohoku 2011 earthquake.To verify the reliability of this method,we performed an extended analysis using data from magnetometer arrays JMA,MAGDAS,PWING,and INTERMAGNET.The selected stations included sites close to the epicenter(<300 km)and remote points(~10000 km).The band-integrated spectral power of nighttime magnetic noise decreased significantly from March 6-9,several days before the earthquake.However,such variations occur simultaneously not only at nearby stations but also at distant stations.During this event,the ULF power depression was caused by low global geomagnetic activity,as evidenced by the planetary index SME.Thus,the depression of geomagnetic ULF noise cannot be considered a reliable short-term precursor.展开更多
Complex phenomena such as prolongedly undamped ultra-low frequency oscillation(ULFO)and eigenmode re-excitation are observed in the simulations of hydroelectric power systems.Emphases are put on nonlinearities and mod...Complex phenomena such as prolongedly undamped ultra-low frequency oscillation(ULFO)and eigenmode re-excitation are observed in the simulations of hydroelectric power systems.Emphases are put on nonlinearities and mode interactions,which cannot be analyzed by traditional eigen-analysis methods.In order to investigate the mechanism of the evolvement of the nonlinear dynamic process in ULFO,this paper proposes a method to analyze the mode interactions quantificationally.First,a disturbed trajectory is decoupled into a set of time-varying components.Second,transfer matrices of eigenmodes are extracted along the trajectory.Third,consecutive sequences of eigenvalues and trajectories of components are formed by a proposed technique.Based on the decoupled components and transfer matrices,the mechanisms of mode interactions and inheritance relationships between eigenmodes are analyzed.The causes and developments of the above complex phenomena are revealed by the proposed method in a test two-machine system.Meanwhile,the accuracy of the eigenmode matching technique is verified in the New England system.展开更多
With the development of low dielectric permittivity materials having an ultra-low sintering temperature,testing their dielectric properties at terahertz frequencies suitable for 6G communication systems and implementa...With the development of low dielectric permittivity materials having an ultra-low sintering temperature,testing their dielectric properties at terahertz frequencies suitable for 6G communication systems and implementation of the fabricated materials in ultra-low temperature cofired ceramics(ULTCC)were the main goals of the research.Lithium tungstate Li_(2)WO_(4)was synthesized by a solid-state reaction and used for the preparation of green tapes and test structures with cofired internal conductive layers,which are destined for substrates of microwave and submillimeter wave circuits.Sintering behavior,thermal effects,and mass changes of the green tapes during heating were studied using a hot-stage microscope,differential thermal analysis,and thermogravimetry.A single-phase composition was revealed for being undoped and doped with AlF3–CaB_(4)O_(7)ceramics.The impact of frequency,temperature,the addition of AlF3–CaB_(4)O_(7)and CuBi_(2)O_(4)dopants,and sintering temperature was the subject of in-depth characterization of dielectric properties in a terahertz region.A glass-free composition,ultra-low sintering temperature of 590–630℃,low roughness of the green tapes,dense microstructure,compatibility with Ag conductors,low and stable dielectric permittivity of 5.0–5.8 in a broad range of 0.2–2 THz,and low dielectric loss of 0.008–0.01 at 1 THz are the main advantages of the developed ULTCC substrates.展开更多
目的:探讨双背侧前额叶高频重复经颅磁刺激(repetitive transcranial magnetic stimulation,rTMS)治疗精神分裂症难治性阴性症状的疗效和安全性,并观察不良反应。方法:本研究为双盲随机对照临床试验。研究对象来源于2002年11月1日至2003...目的:探讨双背侧前额叶高频重复经颅磁刺激(repetitive transcranial magnetic stimulation,rTMS)治疗精神分裂症难治性阴性症状的疗效和安全性,并观察不良反应。方法:本研究为双盲随机对照临床试验。研究对象来源于2002年11月1日至2003年12月31日期间就诊于北京大学第六医院和北京安定医院的门诊和住院患者,符合美国精神疾病诊断与统计手册第4版(Diagnostic and Statistical Manual of Mental Disorders,Fourth Edition,DSM-IV)中精神分裂症诊断标准。23例以难治性阴性症状为主的精神分裂症患者随机分为rTMS治疗组(n=12)和对照组(n=11),分别给予10次20Hz rTMS真刺激和伪刺激治疗,治疗期间维持原有抗精神病药种类及剂量不变。采用阳性和阴性症状量表(Positive and Negative Syndrome Scale,PANSS)评估临床症状,采用治疗中需处理的不良反应症状量表(Treatment Emergent Symptom Scale,TESS)及其他检查评估不良反应。结果:23例患者均完成治疗。治疗组有效率高于对照组(34%vs.17%,P<0.05)。未观察到明显不良反应。结论:抗精神病药合并20Hz双背侧前额叶重复经颅磁刺激治疗精神分裂症难治性阴性症状有效、安全。展开更多
目的观察低频重复经颅磁刺激(repetitive transcranial magnetic stimulation,rTMS)治疗脑卒中后失眠的临床疗效。方法收集2018年12月至2019年12月武汉大学中南医院康复医学科住院的脑卒中失眠患者58例,男35例,女23例,采用随机数字法将...目的观察低频重复经颅磁刺激(repetitive transcranial magnetic stimulation,rTMS)治疗脑卒中后失眠的临床疗效。方法收集2018年12月至2019年12月武汉大学中南医院康复医学科住院的脑卒中失眠患者58例,男35例,女23例,采用随机数字法将患者分为对照组(n=28)和rTMS治疗组(n=30),两组患者均接受常规基础性治疗和康复护理,对照组患者给予口服阿普唑仑片治疗失眠,rTMS治疗组患者接受低频rTMS治疗,疗程均为1个月。比较两组患者治疗前和治疗1个月后匹兹堡睡眠质量指数量表(Pittsburgh sleep quality index,PSQI)评分、神经功能缺损评分(National Institutes of Health Stroke Scale,NIHSS)以及不良反应发生率的差异。结果两组患者治疗前PSQI和NIHSS评分比较无统计学差异(均P>0.05);治疗1个月后,两组患者PSQI和NIHSS评分均较治疗前改善(均P<0.05),且rTMS治疗组PSQI及NIHSS评分改善程度高于对照组(P<0.05)。对照组不良反应发生率高于治疗组(P<0.05)。结论低频rTMS能有效改善脑卒中后失眠患者的睡眠质量,促进患者神经功能的恢复,安全性高,值得临床推广应用。展开更多
目的探讨低频重复经颅磁刺激(repeated transcranialmagnetic stimulation,rTMS)联合法舒地尔对急性脑梗死患者神经功能的影响及机制的研究。方法选取2017年1月~2019年1月期间收治的急性脑梗死患者120例作为研究对象,随机分为4组,对照...目的探讨低频重复经颅磁刺激(repeated transcranialmagnetic stimulation,rTMS)联合法舒地尔对急性脑梗死患者神经功能的影响及机制的研究。方法选取2017年1月~2019年1月期间收治的急性脑梗死患者120例作为研究对象,随机分为4组,对照组、法舒地尔组、rTMS组、法舒地尔+rTMS组,每组30例患者,观察记录4组治疗前后美国国立卫生研究院卒中量表(National Institutes of Health Stroke Scale,NIHSS)评分、日常生活活动(Activity of Daily Living,ADL)评分、血清GAP-43、血清RhoA、血清ROCK-Ⅱ等指标的变化。结果4组患者在治疗后的ADL评分、血清GAP-43水平均高于治疗前(P<0.05);治疗后4组患者的NIHSS评分、血清RhoA及血清ROCK-Ⅱ的水平均低于治疗前(P<0.05);治疗后法舒地尔+rTMS组的ADL评分、血清GAP-43水平均高于其他三个组(P<0.05);治疗后法舒地尔+rTMS组的NIHSS评分、血清RhoA及血清ROCK-Ⅱ的水平均低于其他3个组(P<0.05);各组治疗后NIHSS评分与RhoA、ROCK-Ⅱ含量呈正相关,与GAP-43含量、ADL评分呈负相关。结论低频rTMS联合法舒地尔治疗急性脑梗死可以显著改善患者神经功能缺损,提高患者日常生活能力,促进神经轴突重塑及再生,通过上调血清GAP-43的表达、降低血清RhoA及ROCK-Ⅱ的表达水平可能是其机制之一,具有较高的临床应用价值。展开更多
基金Sichuan cadre health research project(2017-1601)Scientific research and development plan project of North Sichuan Medical(CBY13-A-QN17、CBY17-B-YB24).
文摘Objective:To investigate the clinical effect of ultra-low frequency repetitive transcranial magnetic stimulation on dysphagia in elderly patients with acute cerebral infarction and its impact on quality of life.Methods:60 elderly patients with dysphagia caused by acute cerebral infarction were randomly divided into rTMS group and control group,30 cases in each group.Both groups received routine drug therapy and swallowing function training.rTMS group was additionally treated by ultra-low frequency(10mHZ)repetitive transcranial magnetic stimulation for 14 days.The changes of NIHSS score andADL score and NSE serum level and Wa Tian drinking water experiment and Fujishima Ichiro dysphagia scale score and SWAL-QOL score and SF-36 score were observed between the two groups before and after treatment.The clinical effect was evaluated by Wa Tian drinking water experiment.Results:After treatment,The clinical effective rate in rTMS group was significantly higher compared with that in the control group(P<0.05),NIHSS score and serum NSE level were significantly lower compared with the control group(P<0.05),ADL score and Fujishima Ichiro dysphagia score and SWAL-QOL score and SF-36 scores were significantly higher compared with the control group(P<0.05).After treatment,SF-36 total score(or SWAL-QOL Score)was negatively correlated with NSE serum level and NIHSS score,which was positively correlated with ADL score and Fujishima Ichiro dysphagia scale score score.Conclusion:Ultra-low frequency rTMS therapy can reduce NSE level,effectively improve dysphagia in elderly patients with acute cerebral infarction and significantly improve the elderly patients'life quality.
基金supported by the National Natural Science Foundation of China(Grant Nos.62171414,U2341210,52175554,and 52205608)the Fundamental Research Program of Shanxi Province(Grant Nos.20210302123059,and 20210302124610)+1 种基金the Hebei Province Central Guiding Local Science and Technology Development Fund Project(Grant No.236Z4901G)the National Defense Fundamental Research Project。
文摘In our daily lives,low-frequency kinetic energy primarily manifests as vibrations.However,effective harnessing of lowfrequency kinetic energy remains a formidable challenge.This paper proposes a rope-driven rotor that rotates around an axis and consists of an ultra-high-molecular-weight polyethylene(UHMWPE)wire wrapped around a metal shaft.The rotor can convert ultra-low frequency vibration/linear motion into rapid rotation by pressing the top at low frequencies and driving the rope for a quick release.The harvester can generate up to 36.25 m W power using a 0.1-mm-diameter UHMWPE wire as the rotor when periodically pressed down to 20 mm at a frequency of 1 Hz.A simple power generation floor is assembled,generating 28.58-m W power with a matching load at a frequency of 1.5 Hz.Moreover,the harvester can increase the charging voltage of a 0.47-F supercapacitor from 0 to 6.8 V within 10 min.In addition,the harvester can harvest energy through a light finger press motion,and the energy obtained can also support the continuous operation of multiple electronic devices concurrently.This study introduces an effective method for harvesting ultra-low frequency energy and has great prospects in the field of power generation floor and human movement energy harvesting.
基金supported by the National Natural Science Foundation of China(No.12072221)the Natural Science Foundation of Liaoning Province of China(No.2019-KF-01-09)。
文摘Human motion induced vibration has very low frequency,ranging from 2 Hz to 5 Hz.Traditional vibration isolators are not effective in low-frequency regions due to the trade-off between the low natural frequency and the high load capacity.In this paper,inspired by the human spine,we propose a novel bionic human spine inspired quasi-zero stiffness(QZS)vibration isolator which consists of a cascaded multi-stage negative stiffness structure.The force and stiffness characteristics are investigated first,the dynamic model is established by Newton’s second law,and the isolation performance is analyzed by the harmonic balance method(HBM).Numerical results show that the bionic isolator can obtain better low-frequency isolation performance by increasing the number of negative structure stages,and reducing the damping values and external force values can obtain better low-frequency isolation performance.In comparison with the linear structure and existing traditional QZS isolator,the bionic spine isolator has better vibration isolation performance in low-frequency regions.It paves the way for the design of bionic ultra-low-frequency isolators and shows potential in many engineering applications.
基金supported by Grant 22-17-00125 from the Russian Science Foundation.
文摘Among electromagnetic methods of short-term earthquake prediction,an approach is being actively developed based on the phenomenon of magnetic ultra-low-frequency(ULF)power depression occurring a few days before an earthquake.In particular,a nighttime geomagnetic power depression in the band 0.03-0.05 Hz was observed approximately 5 days before the catastrophic Tohoku 2011 earthquake.To verify the reliability of this method,we performed an extended analysis using data from magnetometer arrays JMA,MAGDAS,PWING,and INTERMAGNET.The selected stations included sites close to the epicenter(<300 km)and remote points(~10000 km).The band-integrated spectral power of nighttime magnetic noise decreased significantly from March 6-9,several days before the earthquake.However,such variations occur simultaneously not only at nearby stations but also at distant stations.During this event,the ULF power depression was caused by low global geomagnetic activity,as evidenced by the planetary index SME.Thus,the depression of geomagnetic ULF noise cannot be considered a reliable short-term precursor.
基金supported by the Program of State Grid Corporation of China“Theoretical BasisAlgorithmand Application of Trajectory Eigenvalue Method”
文摘Complex phenomena such as prolongedly undamped ultra-low frequency oscillation(ULFO)and eigenmode re-excitation are observed in the simulations of hydroelectric power systems.Emphases are put on nonlinearities and mode interactions,which cannot be analyzed by traditional eigen-analysis methods.In order to investigate the mechanism of the evolvement of the nonlinear dynamic process in ULFO,this paper proposes a method to analyze the mode interactions quantificationally.First,a disturbed trajectory is decoupled into a set of time-varying components.Second,transfer matrices of eigenmodes are extracted along the trajectory.Third,consecutive sequences of eigenvalues and trajectories of components are formed by a proposed technique.Based on the decoupled components and transfer matrices,the mechanisms of mode interactions and inheritance relationships between eigenmodes are analyzed.The causes and developments of the above complex phenomena are revealed by the proposed method in a test two-machine system.Meanwhile,the accuracy of the eigenmode matching technique is verified in the New England system.
基金financed by the National Science Centre,Poland(No.2019/35/B/ST5/02674).
文摘With the development of low dielectric permittivity materials having an ultra-low sintering temperature,testing their dielectric properties at terahertz frequencies suitable for 6G communication systems and implementation of the fabricated materials in ultra-low temperature cofired ceramics(ULTCC)were the main goals of the research.Lithium tungstate Li_(2)WO_(4)was synthesized by a solid-state reaction and used for the preparation of green tapes and test structures with cofired internal conductive layers,which are destined for substrates of microwave and submillimeter wave circuits.Sintering behavior,thermal effects,and mass changes of the green tapes during heating were studied using a hot-stage microscope,differential thermal analysis,and thermogravimetry.A single-phase composition was revealed for being undoped and doped with AlF3–CaB_(4)O_(7)ceramics.The impact of frequency,temperature,the addition of AlF3–CaB_(4)O_(7)and CuBi_(2)O_(4)dopants,and sintering temperature was the subject of in-depth characterization of dielectric properties in a terahertz region.A glass-free composition,ultra-low sintering temperature of 590–630℃,low roughness of the green tapes,dense microstructure,compatibility with Ag conductors,low and stable dielectric permittivity of 5.0–5.8 in a broad range of 0.2–2 THz,and low dielectric loss of 0.008–0.01 at 1 THz are the main advantages of the developed ULTCC substrates.
文摘目的:探讨双背侧前额叶高频重复经颅磁刺激(repetitive transcranial magnetic stimulation,rTMS)治疗精神分裂症难治性阴性症状的疗效和安全性,并观察不良反应。方法:本研究为双盲随机对照临床试验。研究对象来源于2002年11月1日至2003年12月31日期间就诊于北京大学第六医院和北京安定医院的门诊和住院患者,符合美国精神疾病诊断与统计手册第4版(Diagnostic and Statistical Manual of Mental Disorders,Fourth Edition,DSM-IV)中精神分裂症诊断标准。23例以难治性阴性症状为主的精神分裂症患者随机分为rTMS治疗组(n=12)和对照组(n=11),分别给予10次20Hz rTMS真刺激和伪刺激治疗,治疗期间维持原有抗精神病药种类及剂量不变。采用阳性和阴性症状量表(Positive and Negative Syndrome Scale,PANSS)评估临床症状,采用治疗中需处理的不良反应症状量表(Treatment Emergent Symptom Scale,TESS)及其他检查评估不良反应。结果:23例患者均完成治疗。治疗组有效率高于对照组(34%vs.17%,P<0.05)。未观察到明显不良反应。结论:抗精神病药合并20Hz双背侧前额叶重复经颅磁刺激治疗精神分裂症难治性阴性症状有效、安全。
文摘目的观察低频重复经颅磁刺激(repetitive transcranial magnetic stimulation,rTMS)治疗脑卒中后失眠的临床疗效。方法收集2018年12月至2019年12月武汉大学中南医院康复医学科住院的脑卒中失眠患者58例,男35例,女23例,采用随机数字法将患者分为对照组(n=28)和rTMS治疗组(n=30),两组患者均接受常规基础性治疗和康复护理,对照组患者给予口服阿普唑仑片治疗失眠,rTMS治疗组患者接受低频rTMS治疗,疗程均为1个月。比较两组患者治疗前和治疗1个月后匹兹堡睡眠质量指数量表(Pittsburgh sleep quality index,PSQI)评分、神经功能缺损评分(National Institutes of Health Stroke Scale,NIHSS)以及不良反应发生率的差异。结果两组患者治疗前PSQI和NIHSS评分比较无统计学差异(均P>0.05);治疗1个月后,两组患者PSQI和NIHSS评分均较治疗前改善(均P<0.05),且rTMS治疗组PSQI及NIHSS评分改善程度高于对照组(P<0.05)。对照组不良反应发生率高于治疗组(P<0.05)。结论低频rTMS能有效改善脑卒中后失眠患者的睡眠质量,促进患者神经功能的恢复,安全性高,值得临床推广应用。
文摘目的探讨低频重复经颅磁刺激(repeated transcranialmagnetic stimulation,rTMS)联合法舒地尔对急性脑梗死患者神经功能的影响及机制的研究。方法选取2017年1月~2019年1月期间收治的急性脑梗死患者120例作为研究对象,随机分为4组,对照组、法舒地尔组、rTMS组、法舒地尔+rTMS组,每组30例患者,观察记录4组治疗前后美国国立卫生研究院卒中量表(National Institutes of Health Stroke Scale,NIHSS)评分、日常生活活动(Activity of Daily Living,ADL)评分、血清GAP-43、血清RhoA、血清ROCK-Ⅱ等指标的变化。结果4组患者在治疗后的ADL评分、血清GAP-43水平均高于治疗前(P<0.05);治疗后4组患者的NIHSS评分、血清RhoA及血清ROCK-Ⅱ的水平均低于治疗前(P<0.05);治疗后法舒地尔+rTMS组的ADL评分、血清GAP-43水平均高于其他三个组(P<0.05);治疗后法舒地尔+rTMS组的NIHSS评分、血清RhoA及血清ROCK-Ⅱ的水平均低于其他3个组(P<0.05);各组治疗后NIHSS评分与RhoA、ROCK-Ⅱ含量呈正相关,与GAP-43含量、ADL评分呈负相关。结论低频rTMS联合法舒地尔治疗急性脑梗死可以显著改善患者神经功能缺损,提高患者日常生活能力,促进神经轴突重塑及再生,通过上调血清GAP-43的表达、降低血清RhoA及ROCK-Ⅱ的表达水平可能是其机制之一,具有较高的临床应用价值。
