Axonal Conduction Velocity: A Computer Study

This paper derives rigorous statements concerning the propagation velocity of action potentials in axons. The authors use the Green’s function approach to approximate the action potential and find a relation between conduction velocity and the impulse profile. Computer simulations are used to bolster the analysis.

Effect of cinepazide combined with mecobalamine on nerve conduction velocity, vibration perception threshold and serum indexes in patients with diabetic peripheral neuropathy

Objective:To analyze the effect of cinepazide combined with mecobalamine on nerve conduction velocity, vibration perception threshold and serum indexes in patients with diabetic peripheral neuropathy. Methods:90 patients with diabetic peripheral neuropathy treated in our hospital between March 2013 and March 2016 were selected and divided into observation group and control group (n=45) according to random number table, control group received mecobalamine treatment alone and observation group accepted the cinepazide combined with mecobalamine therapy. Differences in nerve conduction velocity, vibration perception threshold as well as serum oxidative stress indexes and nerve injury marker molecules were compared between two groups of patients 2 weeks after treatment. Results:2 weeks after treatment, median nerve, ulnar nerve and peroneal nerve sensory nerve conduction velocity (SNCV) and motor nerve conduction velocity (MNCV) levels of observation group were higher than those of control group (P<0.05) while both lower extremities vibration perception threshold (VPT) levels were lower than those of control group (P<0.05). Serum homocysteine (HCY), advanced glycosylation end products (AGEs), malondialdehyde (MDA), neuron-specific enolase (NSE), high mobility group B1 (HMGB1) and S100βcontent of observation group were lower than those of control group (P<0.05) while reduced glutathione (GSH), superoxide dismutase (SOD), myelin basic protein (MBP) and brain-derived neurotrophic factor (BDNF) content were higher than those of control group (P<0.05). Conclusions:Cinepazide combined with mecobalamine can reduce the nerve injury degree, improve nerve conduction and vibration perception and alleviate the oxidative stress degree in patients with diabetic peripheral neuropathy.

Effects of pestle needle on nerve conduction velocity and inflammatory injury in patients with diabetic peripheral neuropathy

Background:Diabetic peripheral neuropathy(DPN)is one of the most common complications of diabetes mellitus.Impaired neurological function is one of the main characteristics of DPN and is strongly associated with the inflammatory response.Our previous studies have confirmed that pestle needle can improve the nerve function of patients with DPN.But the mechanism of pestle needle treatment of DPN is still unclear.Methods:A total of 70 DPN patients who met the inclusion criteria were randomly divided into two groups.Control group(CG)(n=35)received DPN conventional treatment and the pestle needle group(PNG)(n=35)received pestle needle therapy at Zhiyang(DU09)eight array,Mingmen(DU04)eight array and Heche Road(from Mingmen(DU04)to Changqiang(DU01)),Zusanli(ST36),Sanyinjiao(SP06),Taixi(KI03)and Yongquan(KI01).Patients in the PNG group were required to take this treatment for 4 weeks,5 times a week.Examination indexes were collected before and after treatment,respectively.Nerve function was examined using the Toronto clinical scoring system and nerve conduction velocity detection.Serum inflammatory factors were measured by enzyme linked immunosorbent assay.Results:The Toronto clinical scoring system was significantly reduced in the PNG compared with the CG after treatment.The sensory nerve conduction velocity and motor nerve conduction velocity of the right peroneal and median nerves were significantly faster in the PNG than those in the CG(P<0.05).After treatment,serum interleukin-1 beta,interleukin-6 and tumor necrosis factor-alpha levels decreased in both groups,and the improvement of PNG was better than CG(P<0.05).Conclusion:The pestle needle can significantly improve the symptoms and nerve conduction velocity of DPN,and its mechanism may be related to the reduction of inflammatory factors.

Abnormality of peripheral nerve conduction velocity associated with illness course, symptoms and fasting blood glucose in patients with type 2 diabetes mellitus

BACKGROUND: It has shown that abnormality of peripheral nerve conduction velocity during onset of diabetes mellitus is not related to age and sex, but to symptoms, illness course and level of fasting blood glucose. OBJECTIVE: To measure correlation of abnormality of peripheral nerve conduction velocity with various illness courses, symptoms and levels of fasting blood glucose of patients with type 2 diabetes mellitus. DESIGN: Case analysis. SETTING: Department of Neurology, Central People's Hospital of Huizhou. PARTICIPANTS: A total of 128 patients who were diagnosed as type 2 diabetes mellitus were selected from Central People's Hospital of Huizhou from September 2001 to October 2005. There were 75 males and 53 females aged 32-83 years and the illness course ranged from 1 month to 20 years. METHODS: All 128 patients with type 2 diabetes mellitus received neuro-electrophysiological study and their clinical data were retrospectively analyzed to measure peripheral nerve conduction velocity and fasting blood glucose so as to investigate the correlation of peripheral nerve conduction velocity with clinical symptoms, illness course and levels of fasting blood glucose. MAIN OUTCOME MEASURES: Correlation of peripheral nerve conduction velocity with clinical symptoms, illness course and levels of fasting blood glucose. RESULTS: All 128 patients with type 2 diabetes mellitus were involved in the final analysis. ① Among 128 patients, 114 patients had abnormality of peripheral nerve conduction velocity; 110 patients had clinical symptoms, including 102 patients having abnormality of peripheral nerve conduction velocity; 18 patients did not have clinical symptoms, including 12 patients having abnormality of peripheral nerve conduction velocity. There were significant differences between them (χ 2=8.275, P =0.04). ② Among 128 patients, illness course of 75 patients was equal to or less than 5 years, including 27 patients having abnormality of peripheral nerve conduction velocity; illness course of 53 patients was more than 5 years, including 35 patients having abnormality of peripheral nerve conduction velocity. There were significant differences between them (χ 2=11.469, P =0.003). ③ Among 128 patients, levels of fasting blood glucose of 75 patients was equal to or lower than 11 mmol/L, including 41 patients having abnormality of peripheral nerve conduction velocity; levels of fasting blood glucose of 53 patients was higher than 11 mmol/L, including 38 patients having abnormality of peripheral nerve conduction velocity. There were significant differences between them (χ 2=4.023, P =0.134). CONCLUSION: ① Abnormality of peripheral nerve conduction velocity of patients with type 2 diabetes mellitus is related to illness courses and clinical symptoms. The longer the illness course is, the severer the abnormality of peripheral nerve conduction velocity is. Abnormality of peripheral nerve conduction velocity always occurs on patients who have clinical symptoms. ② Abnormality of peripheral nerve conduction velocity is not related to levels of fasting blood glucose.

Impacts of anisotropy coefficient and porosity on the thermal conductivity and P-wave velocity of calcarenites used as building materials of historical monuments in Morocco

It is essential to study the porosity,thermal conductivity,and P-wave velocity of calcarenites,as well as the anisotropy coefficients of the thermal conductivity and P-wave velocity,for civil engineering,and conservation and restoration of historical monuments.This study focuses on measuring the thermal conductivity using the thermal conductivity scanning(TCS)technique and measuring the P-wave ve-locity using portable equipment.This was applied for some dry and saturated calcarenite samples in the horizontal and vertical directions(parallel and perpendicular to the bedding plane,respectively).The calcarenites were selected from some historical monuments in Morocco.These physical properties were measured in the laboratory to find a reliable relationship between all of these properties.As a result of the statistical analysis of the obtained data,excellent linear relationships were observed between the porosity and both the thermal conductivity and porosity.These relationships are characterized by relatively high coefficients of determination for the horizontal and vertical samples.Based on the thermal conductivity and P-wave velocity values in these two directions,the anisotropy coefficients of these two properties were calculated.The internal structure and the pore fabric of the calcarenite samples were delineated using scanning electron microscopy(SEM),while their chemical and mineral compositions were studied using the energy dispersive X-ray analysis(EDXA)and X-ray diffraction(XRD)techniques.

Determination of Thermal Conductivity and Porosity of Building Stone from Ultrasonic Velocity Measurements

Ultrasonic velocity measurement, a non-destructive and easy method to apply in both field and laboratory conditions, has increasingly been conducted to determine the physical properties of rock materials. This paper presents an experimental study of the measurement of P-wave velocity, thermal conductivity and porosity of several types of sedimentary, metamorphic, and magmatic rocks. The aim of this study is to predict the rocks properties including their thermal conductivity and porosity using P-wave velocity. For this purpose, the physical properties are determined in the laboratory to obtain correlations between P-wave velocity and physical properties. Consequently, good linear relationships are found between all the determined physical properties and the P-wave velocity measurements.

Preliminary analysis for the roles of crustal low-velocity and high-conductivity body in process of strong earthquake preparation

In this paper, the roles of low velocity and high conductivity body inside the crust in the process of strong earth quake preparation are approached by using theoretical analysis method based on the comprehensive researches on the fine structure of strong seismic source in the North China. The following results are obtained. The low-velocity and high-conductivity body plays the promoting role for the action of deep-seated structure in the medium stage of earthquake preparation, except that its existence is advantageous to the stress concentrating in the overlying brittle layer during the process of earthquake preparation. And it plays the triggering role for the occurrence of strong earthquake in the later stage of earthquake preparation.

Effects of nonlinear velocity slip and temperature jump onpseudo-plastic power-law fluid over moving permeable surface in presence of magnetic field

Flow and heat transfer of a pseudo-plastic power-law fluid over a stretching permeable surface with the magnetic effect is investigated. In the boundary conditions,the nonlinear temperature jump and the velocity slip are considered. Semi-similarity equations are obtained and solved by bvp4c with MATLAB. The problem can be considered as an extension of the previous work done by Mahmoud(Mahmoud, M. A. A. Slip velocity effect on a non-Newtonian power-law fluid over a moving permeable surface with heat generation. Mathematical and Computer Modelling, 54, 1228–1237(2011)). Efforts are made to discuss the effects of the power-law number, slip velocity, and temperature jump on the dimensionless velocity and temperature distribution.

Study on the correlation between apolipoprotein A1 and apolipoprotein B and carotid-femoral pulse wave velocity

Objective:To explore the association between lipoprotein and arteriosclerosis in hospitalized and outpatient populations in western Beijing.Methods:Patients enrolled in the outpatient department and hospitalization from January 2013 to December 2017 were selected and eventually 258 cases were included in the study according to strict enrollment and exclusion criteria. The data were true and reliable. Statistically, an independent sample t-test and correlation analysis method were used, and the receiver operating characteristic curve was plotted using the predicted values of apolipoprotein A1 and apolipoprotein B for arteriosclerosis by controlling confounding factors.Results: Correlation analysis showed that there was a significant correlation between apolipoprotein B (P=0.007, correlation coefficient: -0.203) and carotid-femoral pulse wave velocity. Apolipoprotein A1 and apolipoprotein B had a strong diagnostic value for arteriosclerosis in patients without coronary heart disease. Conclusions: There is a significant negative correlation between apolipoprotein B and carotid-pulse wave velocity in the unconflicted patients in this study. Apolipoprotein A1 and apolipoprotein B have diagnostic value for arteriosclerosis.

Effect of electroacupuncture on conduction velocity of the sciatic nerve in experimental diabetic rats and its mechanisms

Objective To investigate the mechanisms of acupuncture in accelerating regeneration of injured sciatic nerve, the effect of electroacupuncture （EA） at ＂Huantiao （环跳 GB 30）＂ and ＂Zusanli （足三里 ST 36）＂ on conduction velocity and mRNA expression of receptors of advanced glycation end products （RAGE） of the sciatic nerve were observed in experimental diabetic rats. Methods Streptozotocin was injected into the left abdomen in 30 male rats to establish diabetes mellitus （DM） models with hyperglycemia （〉16.7 mmol/L）. Thirty rats with DM were divided into a diabetes model group （group DM）, a Methycobal group （group MET） and an EA group （group EA）. Another 8 rats comparable in body weight and age were used as a normal control group （group NC）. General situation and blood sugar levels of all the rats were recorded, and the conduction velocities of the sciatic nerves were measured. RAGE mRNA expression of the sciatic nerve was detected by means of reverse transcription polymerase chain reaction（RT-PCR）16 weeks after treatment. Results After 16 weeks, the conduction velocities of the sciatic nerves were lowered in group DM, compared with those in group NC, indicating lesion of peripheral nerves. Compared with group DM, the conduction velocities of the sciatic nerves were significantly elevated in both group EA and group MET （P〈0.01 ）, and there was a significant difference between the two groups, showing superiority of EA to Methycobal （P〈0.01）. The RAGE mRNA levels of the sciatic nerves in group DM were significantly higher than those in group NC （P〈0.01）. The RAGE mRNA levels of the sciatic nerves in both group EA and group MET were remarkably lowered than those in group DM （P〈0.01）, and the decrease in group EA was more obviously than that in group MET （P〈0.01）. Conclusion EA may exert its therapeutic effects on diabetic perineuropathy （DPN） by way of regulating abnormal expression of RAGE mRNA in the sciatic nerve and alleviating its injury caused by advanced glycation end products （AGEs） accumulation and diminishing oxidative stress to enhance its conduction velocity.

梅花针组穴叩刺法联合定点旋转复位法治疗神经根型颈椎病的临床研究

目的分析梅花针组穴叩刺法联合定点旋转复位法治疗神经根型颈椎病的效果及对患者疼痛、肌电图的影响。方法选取河南省洛阳正骨医院2021年4月至2024年4月103例神经根型颈椎病患者临床资料,按治疗方案分组,其中行旋转复位法治疗的34例为复位组,行梅花针组穴叩刺法治疗的34例为叩刺组,行旋转复位联合梅花针组穴叩刺治疗的35例为联合组。对比三组治疗效果、疾病相关评分[颈椎功能障碍指数(NDI)、颈椎病临床评价量表(CASCS)、视觉模拟评分法(VAS)评分]、肌电图指标、颈椎活动度。结果治疗4周后联合组治愈率为80.00%,高于复位组52.94%、叩刺组55.88%(P<0.05);治疗4周后联合组NDI、VAS评分低于复位组、叩刺组,CASCS评分高于复位组、叩刺组(P<0.05);治疗4周后联合组正中神经、腋神经的潜伏期均低于复位组、叩刺组,运动传导速度均高于复位组、叩刺组(P<0.05);治疗4周后颈椎侧屈、前屈、后伸活动度高于复位组、叩刺组(P<0.05)。结论神经根型颈椎病经梅花针组穴叩刺联合定点旋转复位治疗可提高治愈率,纠正颈椎功能,恢复颈椎活动度,改善神经传导功能,提高神经运动传导速度。

Thermal Conductivity and Heat Transfer Coefficient of Concrete

A very simple model for predicting thermal conductivity based on its definiensis was presented. The thermal conductivity obtained using the model provided a good coincidence to the investigations performed by other authors. The heat transfer coefficient was determined by inverse analysis using the temperature measurements. From experimental results, it is noted that heat transfer coefficient increases with the increase of wind velocity and relative humidity, a prediction equation on heat transfer coefficient about wind velocity and relative humidity is given.

Estimation of ultra-stability of methane hydrate at 1 atm by thermal conductivity measurement

Thermal conductivity of methane hydrate was measured in hydrate dissociation self-preservation zone by means of the transient plane source（TPS） technique developed by Gustafsson.The sample was formed from 99.9%（volume ratio） methane gas with 280 ppm sodium dodecyl sulfate（SDS） solution under 6.6 MPa and 273.15 K.The methane hydrate sample was taken out of the cell and moved into a low temperature chamber when the conversion ratio of water was more than 90%.In order to measure the thermal conductivity,the sample was compacted into two columnar parts by compact tool at 268.15 K.The measurements are carried out in the temperature ranging from 263.15 K to 271.15 K at atmospheric pressure.Additionally,the relationship between thermal conductivity and time is also investigated at 263.15 K and 268.15 K,respectively.In 24 h,thermal conductivity increases only 5.45% at 268.15 K,but thermal conductivity increases 196.29% at 263.15 K.Methane hydrates exhibit only minimal decomposition at 1 atm and the temperature ranging from 263.15 K to 271.15 K.At 1 atm and 268.15 K,the total gas that evolved after 24 h was amounted to less than 0.71% of the originally stored gas,and this ultra-stability was maintained if the test was lasted for more than two hundreds hours before terminating.

Study on the Electrical Conductivity of 0.025 mol NaCl Solution at 0.25-3.75 GPa and 20-370℃

The electrical conductance of 0.025 mol NaCl solution was measured at0.25-3.75 GPa and 20-370℃. As shown by the results, the conductance increases with temper-ature, and there is a liner relation between the reciprocal of temperature and the logarithm ofthe conductance but their slopes are different at different pressures. The relations between theconductance and pressure is rather complex and there are some discontinuities: in the range of2.25-3.75 GPa, the conductance increases with the pressure; in the range of 1.25-2.0 GPa, theconductance is not related to the pressure; and at a pressure of 0.75 GPa, the conductance ishigher than that at the pressures nearby. This reflects that the NaCl solution has rather differentproperties of electronic chemistry at various pressures, and probably is an important cause forthe existence of the layers with high electrical conductance and low velocity in the Earth's crustand mantle.

Modelling of Electrical Conductivity of a Silver Plasma at Low Temperature

During the working of electrical fuses, inside the fuse element the silver ribbon first begins to melt, to vaporize and then a fuse arc appears between the two separated parts of the element. Second, the electrodes are struck and the burn-back phenomenon takes place. Usually, the silver ribbon is enclosed inside a cavity filled with silica sand. During the vaporization of the fuse element, one can consider that the volume is fixed so that the pressure increase appears to reach pressures higher than atmospheric pressure. Thus, in this paper two pressures, 1 atm and 10 atm, are considered. The electrical field inside the plasma can reach high values since the distance between the cathode surface and the anode surface varies with time. That is to say from zero cm to one cm order. So we consider various electrical fields： 102 V/m, 103 V/m, 5×103 V/m, 104 V/m at atmospheric pressure and 105 V/m at a pressure of 10 atm. This study is made in heavy species temperature range from 2,400 K to 10,000 K. To study the plasma created inside the electric fuse, we first need to determine some characteristics in order to justify some hypotheses. That is to say： are the classical approximations of the thermal plasmas physics justified？ In other words： plasma frequency, the ideality of the plasma, the Debye-Hückel approximation and the drift velocity versus thermal velocity. These characteristics and assumptions are discussed and commented on in this paper. Then, an evaluation of non-thermal equilibrium versus considered electrical fields is given. Finally, considering the high mobility of electrons, we evaluate the electrical conductivities.

Electrical Conductivity in a Non-Maxwellian Plasma with Adjustable High-Energy-Tail Distribution

In this paper, a solution to the Fokker-Planck equation is presented, which is extended to the field particles＇ high-energy-tail non-Maxwellian velocity distribution function in transport theory. Based on the correct physical concept of collision intensity, introduced by CHANG and LI, the electrical conductivities for like-particles collisions are obtained in different conditions. The modified Fokker-Planck coefficients for non-Maxwellian scattering are applied in the study. It is found that the parallel part of the collision operator plays an important role. The non-Maxwellian scattering will stimulate the transport processes in various degrees with mutative deviation parameters.

The experimental studies on electrical con-ductivities and P-wave velocities of anortho-site at high pressure and high temperature

Results of P-wave velocity (vP) and electrical conductivity measurements on anorthosite are presented from room temperature to 880 C at 1.0 GPa using ultrasonic transmission technique and impedance spectra technique respec-tively. The experiments show that the P-wave velocities in anorthosite decrease markedly above 680 C following the dehydration of hydrous minerals in the rock, and the complex impedances collected from 12 Hz to 105 Hz only indicate the grain interior conduction mechanism at 1.0 GPa, from 410 C to 750 C. Because the fluids in the rock have not formed an interconnected network, the dehydration will not pronouncedly enhance the electrical conduc-tivity and change the electrical conduction mechanism. It is concluded that the formation and evolution of the low-velocity zones and high-conductivity layers in the crust may have no correlations, and the dehydration can result in the formation of the low-velocity zones, but cannot simultaneously result in the high-conductivity layers.

Anomalously High Conductivity of Deformed Metals at the Positive Temperatures

The description of experimentally observed phenomenon of abnormally high electrical conductivity—'superconductivity' (SC) at the room and higher temperatures is represented. The effect was observed in metallic monospirals of small radius curvature with high density and regular distribution of dislocations. Transition into state of SC has been observed experimentally in the range from –50 up to 3000°C at the density of transmitting current up to 2·109 A/cm2. The experimental data confirming the watched phenomenon are represented. The explanations of this phenomenon are being proposed in the framework of the dislocation model.

高压氧治疗脊髓损伤的临床效果及对神经电生理的影响

目的探讨高压氧治疗脊髓损伤的临床效果及对神经电生理的影响。方法选取2019年10月至2022年6月吉林大学第二医院脊柱外科收治的104例脊髓损伤患者,采用随机数字表法分为对照组和观察组,每组52例。对照组采用常规治疗,观察组在常规治疗的基础上给予高压氧治疗。比较两组治疗前后的美国脊柱损伤协会(ASIA)神经功能分级,正中神经、尺神经、胫神经、腓总神经的运动神经传导速度(MCV)、感觉神经传导速度(SCV),以及血清白介素(IL)-6、IL-10、IL-17、超敏C反应蛋白(hs-CRP)水平。结果治疗前两组ASIA神经功能分级、MCV、SCV及血清IL-6、IL-10、IL-17、hs-CRP水平比较差异均无统计学意义(P>0.05)。与治疗前相比,治疗后两组ASIA神经功能分级均明显改善,且观察组明显优于对照组,正中神经、尺神经、胫神经、腓总神经MCV及SCV均明显增高,且观察组明显高于对照组,血清IL-6、IL-10、IL-17、hs-CRP水平均明显降低,且观察组明显低于对照组,差异有统计学意义(P<0.05)。结论高压氧治疗脊髓损伤可显著改善神经功能,提高运动及感觉神经传导速度,减轻炎症反应。

依帕司他联合丁苯酞软胶囊对痛性糖尿病周围神经病变患者的影响

目的:分析依帕司他联合丁苯酞软胶囊对痛性糖尿病周围神经病变(PDPN)患者的影响。方法:选取2021年2月—2022年2月通城县人民医院收治的80例PDPN患者作为研究对象,根据掷硬币法将患者分为对照组和研究组,各40例。对照组给予依帕司他,研究组在对照组基础上给予丁苯酞软胶囊,比较两组临床疗效、不良反应、疼痛程度[视觉模拟评分法(VAS)]、正中神经、腓总神经、尺神经的感觉神经传导速度(SNCV)、运动神经传导速度(MNCV)及氧化应激指标[超氧化物歧化酶(SOD),丙二醛(MDA)]水平。结果:研究组临床总有效率高于对照组,差异有统计学意义(P<0.05);两组不良反应发生率比较,差异无统计学意义(P>0.05);治疗1个月后,两组VAS评分低于治疗前,且研究组低于对照组,差异有统计学意义(P<0.05);治疗1个月后,两组正中神经、腓总神经、尺神经的SNCV和MNCV较治疗前提高,且研究组高于对照组,差异有统计学意义(P<0.05);治疗1个月后,两组SOD和MDA水平较治疗前改善,且研究组SOD水平高于对照组,MDA水平低于对照组,差异有统计学意义(P<0.05)。结论:依帕司他与丁苯酞软胶囊联合治疗PNDN,临床疗效好,不良反应发生率较低,能显著降低疼痛程度,提高正中神经、腓总神经、尺神经SNCV和MNCV,改善SOD和MDA水平。