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...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.展开更多
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 supe...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.展开更多
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 th...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.展开更多
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 d...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.展开更多
Objective: Health care providers refer their patients to electromyography (E<span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdan...Objective: Health care providers refer their patients to electromyography (E<span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">MG) 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-</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">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.</span></span></span><span><span><span style="font-family:;" "=""> </span></span></span><span><span><span style="font-family:;" "=""><span style="font-family:Verdana;">Results: All EMGs, F-wave, and H-reflex reports reviewed were normal, including those obtained </span><span style="font-family:Verdana;">from the second procedure performed in some patients and of those who su</span><span style="font-family:Verdana;">bsequently underwent spinal surgery. Neurologic examination in all patients</span><span style="font-family:Verdana;"> was </span><span style="font-family:Verdana;">normal. Conclusion: Needle EMG, F-wave and H-Reflex examinations are pr</span><span style="font-family:Verdana;">edictably normal in patients with non-dermatomal, non-neuropathic sensory symptoms with normal neurologic examination and without history of pre</span></span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">existing medical and surgical disorders. A good neurologic examination sh</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">ould determine the need to perform these procedures. Our findings have important diagnostic, therapeutic, prognostic, economic and legal implications</span></span></span><span style="font-family:Verdana;">.</span>展开更多
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 sp...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.展开更多
文摘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.
基金Supported by the"333"Project Funds of Jiangsu Province of China,the National Natural Science Foundation of China under Grant No.20571029by the Program for Excellent Talents in Huangshi Institute of Technology
文摘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.
文摘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.
文摘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.
文摘Objective: Health care providers refer their patients to electromyography (E<span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">MG) 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-</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">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.</span></span></span><span><span><span style="font-family:;" "=""> </span></span></span><span><span><span style="font-family:;" "=""><span style="font-family:Verdana;">Results: All EMGs, F-wave, and H-reflex reports reviewed were normal, including those obtained </span><span style="font-family:Verdana;">from the second procedure performed in some patients and of those who su</span><span style="font-family:Verdana;">bsequently underwent spinal surgery. Neurologic examination in all patients</span><span style="font-family:Verdana;"> was </span><span style="font-family:Verdana;">normal. Conclusion: Needle EMG, F-wave and H-Reflex examinations are pr</span><span style="font-family:Verdana;">edictably normal in patients with non-dermatomal, non-neuropathic sensory symptoms with normal neurologic examination and without history of pre</span></span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">existing medical and surgical disorders. A good neurologic examination sh</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">ould determine the need to perform these procedures. Our findings have important diagnostic, therapeutic, prognostic, economic and legal implications</span></span></span><span style="font-family:Verdana;">.</span>
基金This work was supported by the funds from the Medical and Health Science and Technology Development Project of Shandong Province,China(grant nos.2015WS0375 and 2019WS125)Scientific and Technological Project of Henan Province,China(grant nos.192102310114 and 192102310110).
文摘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.
