Josephson Current in f-Wave Superconductor/f-Wave Superconductor Junctions

We study the temperature T and the phase of the Josephson critical current I（Ф） by taking into account the roughness scattering effect at inerface in an f-wave superconductor （S）/Insulator layer （I）/f-wave superconductor （S） junction. It is found that the Josephson critical currents in f-wave Sir-wave S, the barrier strength and the roughness strength at inerface always suppress the Andreev reflection. When α=β, the phase dependence of the Josephson current I（Ф） between two f-wave S is predicted to be sin Ф; particularly, when a α≠ β, the phase dependence of the Josephson current I（Ф） between two f-wave superconductors is not predicted to be sin Ф and with the barrier strength increasing, the period of the I（Ф） turns decrease.

Spin-Polarized Tunneling Spectroscopy and Shot Noise in Ferromagnet／f-WaveSuperconductor Junctions

The tunneling spectroscopy and shot noise in ferromagnet/insulator/triplet-superconductor (FM/I/triplet- SC) structures are studied by taking into account the roughness interracial barrier and exchange splitting in the FM. For the triplet-SG of Sr_2RuO_4,we consider two-dimensional f-wave order parameter symmetries having nodes within the RuO_2 plane,which reasonably describe both thermodynamic and thermal conductivity data.It is shown that the ferromagnetic exchange splitting gives rise to a decrease in the differential conductance,the average current,and the shot noise power,while the noise power-to-current ratio is increased;the interface roughness is found to lead to a decrease in the differential conductance and the average current,and an increase in the noise power-to-current ratio.

Alternation in F-wave parameters of median nerve from unaffected extremity in stroke patients with hemiplegia under dynamic state

BACKGROUND: For many years, the extremities of stroke patients are divided into affected side and unaffected side according to clinical symptoms and body signs. Moreover, previous rehabilitation function training is developed simply aiming to the dysfunction manifested by unaffected extremity. Problems of unaffected extremity are always ignored, such as left- and right- side connection dysfunction, abnormal muscular tension of unaffected side and so on. OBJECTIVE: To observe neurophysiological change characteristics of unaffected extremity of stroke patients with hemiplegia by electromyographical method. DESIGN: Case-control observation. SETTING: First Hospital, Jilin University. PARTICIPANTS: Eighty stroke patients with hemiplegia confirmed by skull CT or MRI, who firstly hospitalized in the Department of Neurology, First Hospital, Jilin University between July 2004 and March 2005, were retrieved. They were scored > 8 points in Glasgow Coma Scale and had stable vital sign. Nineteen normal persons who received healthy examination in the clinic were involved in normal control group. Following the classification criteria of Brunnstrom's Recovery Stages of Stroke (BRSS), 80 stroke patients with hemiplegia were assigned into 3 groups: BRSS Ⅰ-Ⅱ group (n =36), BRSS Ⅲ-Ⅳ group (n =23) and BRSSⅤ-Ⅵ (n =21). METHODS: F-wave parameters of median nerve of unaffected extremity were detected by electromyographical technique. The recording electrode (muscular belly of abductor pollicis brevis) and reference electrode (first finger bone) were connected with grounding electrode. Stimulating electrode was placed in the median part of wrist joint with stimulation intensity of 130% that of threshold stimulation, stimulation frequency of 2 Hz, current pulse width of 0.2 ms, time course of 5 ms and sensitivity of 2 mV. The F-wave of median nerve of affected extremity under the resting stage (static status) and that of unaffected extremity under the maximum resistant contracted state were detected in order. The amplitude and appearance percentage of F wave were recorded. MAIN OUTCOME MEASURES: Comparison of F-wave parameters of median nerve between the unaffected extremity of stroke patients with hemiplegia and the extremity of control subjects under different status. RESULTS: All the patients accomplished the detection, and all of them participated in the final analysis. ①Under dynamic status, the amplitude and appearance percentage of F wave of unaffected extremity of patients in BRSS Ⅲ-Ⅳ group were significantly higher than those in the normal control group, respectively[(0.803 9±0.157 3) mV vs. (0.406 7±0.170 3) mV; (0.856 1±0.266 8)% vs. (0.650 0±0.197 6)%, P < 0.05]. Under static status, there were no significant differences in F-wave parameters of median nerve in the unaffected extremity of patients between BRSS Ⅰ-Ⅱ group and BRSS Ⅴ-Ⅵ group (P > 0.05). ②F-wave parameters of median nerve of unaffected extremity of patients in BRSS Ⅰ-Ⅱ group and BRSS Ⅴ-Ⅵ group under dynamic statewere higher than those under static status, without significant difference (P > 0.05), while the amplitude and appearance percentage of F wave of median nerve of unaffected extremity of patients in BRSS Ⅲ-Ⅳ group under dynamic statewere significantly higher than those under static state[(0.803 9±0.157 3) mV vs. (0.391 7±0.131 6) mV; (0.856 1±0.266 8 )% vs.(0.639 1 ±0.259 4)%,P < 0.05]. ③ There was no significant difference in F wave parameters among groups under static state(P > 0.05). However, under dynamic status, the amplitude and appearance percentage of F wave parameters of median nerve of unaffected extremity of patients in BRSS Ⅲ-Ⅳ group [(0.803 9±0.157 3) mV,(0.856 1±0.266 8)%] were significantly lower than those in the other two groups [(0.395 1±0.148 8),(0.437 1±0.157 6) mV;(0.612 5±0.232 8)%,(0.657 1±0.232 5)%,P < 0.05]. CONCLUSION: With the development of disease condition and the increase of muscular tension at anesthetic side, combination motor of affected extremity is caused following movement and muscular tension enhances to non-anesthetic-side. Therefore, F-wave parameters increase under dynamic status.

Needle Electromyography, F-Wave, and H-Reflex: A Critical Reappraisal of Their Utility in the Diagnosis of Various Sensory Symptoms in the Extremities and Spine in the Setting of Normal Neurological Examination

Objective: Health care providers refer their patients to electromyography (EMG) laboratories for the evaluation of various sensory symptoms in the extremities and spine. The procedure is usually performed in conjunction with transcutaneous electrical stimulation of peripheral nerves and elicitation of the F-wave and H-reflex. The present study aimed to determine the real value of these procedures in the diagnosis of sensory symptoms in the setting of a normal neurologic examination. Method: The EMG reports and clinical histories of 100 patients, including 10 patients evaluated by other electromyographers, were reviewed. The study was focused on those with normal neurological examinations and those without histories of ongoing medical disorders and major surgeries to the extremities and spine. Results: All EMGs, F-wave, and H-reflex reports reviewed were normal, including those obtained from the second procedure performed in some patients and of those who subsequently underwent spinal surgery. Neurologic examination in all patients was normal. Conclusion: Needle EMG, F-wave and H-Reflex examinations are predictably normal in patients with non-dermatomal, non-neuropathic sensory symptoms with normal neurologic examination and without history of preexisting medical and surgical disorders. A good neurologic examination should determine the need to perform these procedures. Our findings have important diagnostic, therapeutic, prognostic, economic and legal implications.

Changes of the F-wave in the acute phase of permanent spinal cord ischaemic injury predict spinal cord function in animal models of rabbits

Objective:to explore the changes of the F-wave in the posterior tibial nerve of rabbits after different levels of lumbar spinal cord ischaemic injury and its correlation with motor function and the extent of lumbar spinal cord pathological damage.Methods:thirty New Zealand rabbits were randomly divided into 6 groups.The control group(n=5)was used to exclude the influence of anaesthesia and surgery on the F-wave.Different levels of lumbar arteries were ligated in the five experimental groups(n=5).The F-wave was recorded to observe the changes in the acute phase of spinal cord ischaemia.The correlation between the changes of the F-wave in the acute reversible phase and the motor function of the spinal cord was analysed.Motor functions were assessed after surgery and 2 d after vascular ligation.The specimens were taken 2 d after ligation for histopathologic observation.Results:the results for the control group indicated that anaesthesia and surgery did not affect the F-wave results.There was no statistically significant difference in the F-wave amplitudes and latency before and after ligation in the 1 and 2 level ligation groups.The F-wave changed immediately after ligation in the 3,4 and 5 ligation groups.The latency of the F-wave gradually extended,the amplitude of the F-wave gradually reduced.The amplitude variations of the F-wave were positively correlated with the motor function 2 d after ligation,there was a statistically significant difference.With the increase in the number of vascular ligation,the degree of destruction of the motor neurons in the anterior horn of the spinal cord in the pathological specimens increased.Conclusion:the F-waves in the posterior tibial nerve of rabbits were found to be sensitive to the lumbar spinal cord ischaemic injury and specific to predict motor function.

Interplay between magnetic gap and quasiparticle lifetime in topological insulator ferromagnet/f-wave superconductor junctions

Using the modified Blonder-Tinkham-Klapwijk(BTK)theory,the interplay between the lifetime of quasi particles and the magnetic gap in a topological insulator-based ferromagnet/fwave superconductor(TI-based FM/f-wave SC)tunnel structure is theoretically studied.Two symmetries of f_(1) and f_(2) waves are considered for superconducting pairing states.The results indicate that reducing the finite quasi-particle lifetime will induce a transformation of energy-gap peaks into a zero-bias peak in tunneling conductance spectrum,as well as a transformation of energy-gap dips into a zero-bias dip in shot noise spectrum,ultimately resulting in the smoothing of the zero-bias conductance peak and the zero-bias shot noise dip.An increase in magnetic gap will suppress the tunnel conductance and shot noise when the conventional Andreev retroreflection dominates,but will enhance them when the specular Andreev reflection is dominant.Both specular Andreev reflection and conventional Andreev retro-reflection will be enhanced as the quasi-particle lifetime increases.When Fermi energy equals the magnetic gap,shot noise and tunneling conductance vanish across all energy ranges.These findings not only contribute to a better understanding of specular Andreev reflection in the FM/f-wave SC junction based on TIs but also provide insights for experimentally determining the f-wave pairing symmetry.

利用F-Exp方法求(3+1)维Boussinesq方程的精确解研究

利用F-Exp方法,获得(3+1)维Boussinesq方程的孤立波解,并运用Maple软件获得几种典型解的波形图。该方法还可以应用到其他非线性发展方程的求解中。

GPR绕射波与反射波分离的变分模态分解方法研究

针对传统绕射波与反射波分离方法易造成有效信号丢失的问题,本文利用二维变分模态分解(2D-VMD)进行探地雷达(GPR)数据的绕射波与反射波分离。对二维GPR数据进行2D-VMD分解后,可得到包含从低频低波数到高频高波数的各阶模态分量及各阶模态分量的F-K谱。通过分析绕射波与反射波在频率-波数域的差异,分别重构绕射波与反射波对应的模态分量,得到分离后的绕射波与反射波数据。数值模拟与实测数据处理结果表明,相比于传统方法,该方法可以有效分离绕射波与反射波,并且不损失任何有效信号。

补阳还五汤联合电针对不完全性脊髓损伤患者术后恢复的临床效果

目的观察补阳还五汤联合电针疗法在不完全性脊髓损伤患者术后恢复的临床效果。方法选择2020年12月至2023年4月在浙江中医药大学附属第二医院骨伤科治疗的符合要求的不完全性脊髓损伤患者44例,按照患者治疗意愿,分为对照组和试验组,每组22例。两组均予西医基础治疗,试验组加用补阳还五汤及电针,比较两组美国脊髓损伤协会评分(ASIA)、改良Barthel指数评分(MBI)、视觉模拟评分(VAS)、肌电图F波引出率与离散度,于术后3天及8周各评价一次。结果术后3 d,两组患者在ASIA评分、MBI评分、VAS评分、F波离散度与引出率方面比较,差异无统计学意义(P>0.05)。术后8周,两组上述指标较术后3 d均有改善,而试验组改善程度均优于对照组,差异有统计学意义(P<0.05)。结论补阳还五汤联合电针疗法可促进脊髓神经功能恢复,改善运动与感觉功能,减轻病理性疼痛,提高日常生活质量,是可在临床推广应用的多模式联合疗法。

基于HCOPAR雷达的中国低纬F层V型散射回波研究

基于中国子午工程在海南富克台站获取的甚高频相干散射雷达数据,对低纬度地区电离层F层的场向不均匀体特性进行了细致探究。在此过程中,识别出一种罕见的V型结构不均匀体,进一步绘制后向扇形图,结合测高仪数据分析其时频特性。将分析结果与相应时段的气辉图像进行比对,结果显示这种V型结构不均匀体是由于重力波对电离层背景电场的调制,导致其动力学状态的改变所致。

由背景噪声多阶面波反演阿拉斯加地壳三维横波速度结构

阿拉斯加由若干具有不同构造演变历史的地块构成,其南部边缘受太平洋板块向北美板块俯冲影响,整体构造运动活跃,具有很大的研究价值。本研究从美国阿拉斯加及加拿大西北部地区的310个台站共6年的背景噪声数据中提取出瑞利多阶频散曲线,最终得到研究区域地壳的三维横波速度结构。我们在阿拉斯加地下约10 km~20 km深度范围发现一广泛分布的中地壳低速层。该低速层位于阿拉斯加内陆区域,包括Seward半岛,Yukon-Koyukuk地块,Yukon-Tanana地块及阿拉斯加东南部部分区域。低速层与阿拉斯加四大地热区域中的两个(CAHSB和SEP温泉分布区)高度重合。中地壳低速层与当地地热资源的对应性一定程度上证实了我们所得速度模型的可靠性,同时对该低速层的进一步研究或许有助于阿拉斯加温泉带起源的探索。

一种有效的适合F-J方法从背景噪声资料中提取多阶频散曲线的台阵划分方法

近年发展起来的从地震背景噪声提取多阶频散曲线的F-J方法是一种台阵分析方法,对某一特定的研究区域内台阵的划分方式直接影响成像的效果.当研究区域地下结构较简单,且台站间距比较均匀时,可以使用简单的平移式移动阵列法;然而若研究区域地下结构复杂多变,尤其是台站间距疏密不均时,就需要根据具体的地域特征灵活划分台阵.本文介绍了一种适用于地下结构复杂及台站间距不均匀区域的台阵划分方法,具有一定的普适性.我们将其应用于美国阿拉斯加及加拿大西北部,验证了相比于简单的沿经纬度移动阵列,我们的分区方法确实大大提高了结果的分辨率,为后续反演研究区域三维速度结构提供了坚实的保障.

神经传导、F波及皮肤交感反应联合检测对糖尿病周围神经病变早期诊断的价值

目的采用受试者工作特征曲线(ROC)探讨神经传导检测(NCS)、F波及皮肤交感反应(SSR)联合检测对早期糖尿病周围神经病变的诊断价值。方法对78例糖尿病周围神经病(diabetic peripheral neuropathy,DPN)患者(观察组)和81例单纯糖尿病患者(对照组)进行常规神经传导检测及正中神经和胫后神经F波检测和SSR检测,对单独检测和联合检测的异常率进行比较,并采用ROC曲线分析NCS、F波及SSR联合检测的诊断效能。结果观察组NCS检查总异常率为91.36%。观察组F波总异常率为80.25%。NCS、F波及SSR的联合检验灵敏度与特异度分别为89.41%、86.33%。观察组与对照组相比,患者双侧胫后神经、腓总神经远端动作潜伏期(DML)明显延长,复合肌肉动作电位(CMAP)波幅显著降低(均P<0.05)。观察组与对照组F波检测相比,正中神经、胫后神经Fimin及Fimean延长,F波出现率降低,Fchd增加(均P<0.05)。观察组,上、下肢皮肤交感反应(SSR)起始潜伏期较对照组明显延长(均P<0.05),SSR波幅较对照组明显下降(P<0.05)。结论NCS检测是诊断DPN患者的基本手段,将其与F波及SSR联用,是早期诊断糖尿病自主神经病变的敏感手段,能明显提高亚临床型DPN患者的早期检出率。

91例肌萎缩侧索硬化症的F波和神经传导研究

目的 探讨肌萎缩侧索硬化症(ALS)F波和神经传导改变的特点。方法 所有患者均采用常规方法测定感觉神经传导速度(SCV)、运动末端潜伏期(distal motor latency,DML)和F波,后者的测定包括潜伏期和/或传导速度及出现率。分析了DML和复合肌肉动作电位(compound muscle action potential,CMAP)波幅、F波出现率与肌力的关系。结果 在91例ALS患者中,仅有3例SCV异常;正中神经、尺神经及胫后神经DML延长者分别占16.7％、13.8％、7.1％,CMAP波幅下降者分别占50.0％、44.6％、28.6％;5.0％患者F波传导速度异常,48例患者F波出现率下降,其中19例出现率为0。肌力下降者DML、CMAP波幅及F波出现率改变明显。结论 ALS患者可出现DML延长和CMAP波幅降低,二者比较后者的改变更显著;F波传导速度相对正常而出现率下降明显;DML、CMAP波幅及F波出现率的异常与肌力明显相关(P均<0.01)。

脑卒中恢复期患者偏瘫上肢治疗后肌电F波变化

目的探究脑卒中恢复期患者偏瘫上肢在康复治疗过程中正中神经F波参数变化规律。方法选择脑卒中偏瘫患者30例,所有患者接受为期4周的常规康复治疗,分别于治疗前及治疗4周后对其上肢正中神经行F波参数检测,同时采用改良Ashworth量表评定患侧上肢的痉挛程度,采用上肢Fugl-Meyer量表评估偏瘫侧上肢运动功能。结果治疗前患侧上肢的F波波幅、出现率均低于健侧肢体和正常组,阈值高于健侧及正常组,差异有统计学意义(P<0.05)。治疗后患侧肢体F波波幅、出现率均较治疗前明显上升,阈值下降,差异有统计学意义(P<0.05)。改良Ashworth评分和F波波幅、出现率、阈值等参数有相关性(P<0.05)。结论改良Ashworth评分和F波参数存在相关性,两者可结合用于临床上肢功能障碍的评估。

192例听神经瘤术中神经电生理监测

目的探讨听神经瘤术中电生理监测技术常见问题的处理,提高面神经解剖保留率。方法 192例听神经瘤患者手术时均在面神经电生理监测下进行,采用枕下乙状窦后经内听道入路,显微外科切除肿瘤,术后对面神经功能进行评估。结果肿瘤全切1 8 3例(95.3%),面神经完整解剖保留185例(96.4%)。长期随访病例面神经功能良好率83.0%,术中F波监测结果与术后面神经功能之间有较好的一致性。结论听神经瘤术中神经电生理监测的运用可明显提高面神经的解剖保留率和功能保留优良率,术中F波监测不仅可实时反馈面神经功能状态,而且可为术后面神经功能的预测提供依据。

标准化F波潜伏期对糖尿病周围神经病的诊断价值

目的探讨标准化F波潜伏期在糖尿病周围神经病(DPN)中的诊断价值。方法采用前瞻性研究方法,收集神经传导检查正常的DPN患者48例,另选择年龄和性别匹配的健康自愿者48名为对照组。采用肌电图诱发电位仪检测两组正中神经、尺神经、胫神经及腓总神经F波最短潜伏期(FLmin)、F波平均潜伏期(FLmean)、F波潜伏最长期(FLmax),并结合臂长和腿长计算标准化FLmin、标准化FLmean、标准化FLmax。比较两组间F波潜伏期及标准化F波潜伏期的差异,采用ROC曲线分析不同F波潜伏期在DPN中的诊断价值。结果除尺神经身高标准化FLmax外,DPN组4条神经的肢长和身高标准化F波潜伏期均较对照组延长(P<0.01或P<0.05)。ROC曲线分析显示,除尺神经常规F波潜伏期及身高标准化FLmean和FLmax外,4条神经常规F波潜伏期、身高标准化F波潜伏期及肢长标准化F波潜伏期对DPN均有诊断价值,ROC曲线下面积(AUC)为0.631~0.995(P<0.05),其中正中神经、尺神经、胫神经和腓总神经的肢长标准化FLmin的诊断价值最高,其AUC分别为0.995、0.934、0.940、0.969(均P<0.01)。结论针对神经传导检查正常的DPN患者,标准化F波潜伏期优于常规F波潜伏期,其中肢长标准化F波潜伏期的诊断价值优于身高标准化F波潜伏期。标准化F波潜伏期可作为临床诊断DPN的一个参考指标。

面神经F波对周围性面神经炎的早期诊断意义

目的探讨面神经F波对于周围性面神经炎的早期诊断意义。方法应用肌电图诱发电位检查仪对53例早期(3d内)周围性面神经炎的患者分别检测健侧和患侧面神经F波。结果其中37例严重病变患者患侧面神经F波消失,健侧面神经F波存在。16例轻至中度病变患者患侧面神经F波存在,但患侧面神经F波的平均潜伏期、潜伏期最小值及潜伏期最大值和健侧相比明显延长,患侧F波出现率和健侧相比明显减少。所有53例患者的统计结果表明F波健侧与患侧的差异有高度统计学意义(P<0.0001),健侧明显高于患侧。结论面神经F波作为一种能准确评价面神经颅内段功能的简单、敏感的客观方法,为一种早期诊断周围性面神经瘫痪的客观指标,将在面神经疾病的早期诊断中发挥作用。

采用F波检测头针配合面肌训练治疗顽固性面瘫的临床研究

目的采用F波(F-wave)检测,观察头针配合面肌训练治疗顽固性面瘫的临床疗效。方法将60例顽固性面瘫患者随机分为治疗组和对照组,每组30例。治疗组采用头针配合面肌训练治疗,对照组采用常规针刺治疗。比较两组治疗前后F波潜伏期和时程。结果对照组治疗后F波平均潜伏期与同组治疗前比较,差异具有统计学意义(P<0.01)。治疗组治疗后F波平均潜伏期及平均时程与同组治疗前比较,差异均有统计学意义(P<0.01,P<0.05)。治疗组治疗后F波平均潜伏期及平均时程与对照组比较,差异均具有统计学意义(P<0.01,P<0.05)。结论头针配合面肌训练可缩短顽固性面瘫患者F波潜伏期,延长F波时程,促进运动神经纤维的修复。

脑卒中患者双上肢F波的变化及其评价肢体痉挛的可靠性

目的观察脑卒中患者双上肢正中神经F波的变化特征及其与患侧上肢肌张力的关系,探讨F波在脑卒中患者上肢痉挛评价中的应用价值。方法选取2014-7—2015-7作者医院神经内科收治的脑卒中患者40例(脑卒中组),其中男24例、女16例;选取30名健康者作为正常对照组,其中男18名,女12名。应用丹麦丹迪公司生产的Keypoint.net肌电/诱发电位仪进行F波测定,对脑卒中组患者患侧、健侧及正常对照组F波的潜伏期、出现率、传导速度、波幅及面积进行比较。对脑卒中组患侧上肢进行改良Ashworth评分(MAS),并与F波部分参数进行Spearman相关性分析。结果 (1)脑卒中组患侧、健侧与正常对照组间F波潜伏期、传导速度、波幅及面积比较差异均有统计学意义(P<0.05,P<0.01),F波出现率比较差异无统计学意义(P>0.05);(2)脑卒中组患侧F波传导速度较健侧减慢(P<0.01),波幅增高(P<0.01),面积增大(P<0.01),而F波潜伏期与出现率变化无统计学差异(P>0.05);(3)脑卒中患者患侧潜伏期较正常对照组延长(P<0.01),传导速度减慢(P<0.01),而健侧潜伏期及传导速度与正常对照组间比较差异均无统计学意义(P>0.05);(4)脑卒中患者患侧F波波幅与腕及四指MAS评分均呈正相关(r=0.906,P<0.01;r=0.685,P<0.01),F波面积与腕及四指MAS评分均呈正相关(r=0.917,P<0.01;r=0.669,P<0.01),F波传导速度与四指MAS评分呈负相关(r=-0.524,P<0.05)。结论脑卒中患者患侧上肢F波波幅及面积分别与MAS评分存在正相关,F波传导速度与四指MAS评分存在负相关,F波的传导速度、波幅及面积可作为脑卒中患者上肢痉挛程度评价客观的电生理指标。