Correlating thermal conductivity of pure hydrocarbons and aromatics via perceptron artificial neural network (PANN) method

Accurate estimation of liquid thermal conductivity is highly necessary to appropriately design equipments in different industries. Respect to this necessity, in the current investigation a feed-forward artificial neural network(ANN) model is examined to correlate the liquid thermal conductivity of normal and aromatic hydrocarbons at the temperatures range of 257–338 K and atmospheric pressure. For this purpose, 956 experimental thermal conductivities for normal and aromatic hydrocarbons are collected from different previously published literature.During the modeling stage, to discriminate different substances, critical temperature(Tc), critical pressure(Pc)and acentric factor(ω) are utilized as the network inputs besides the temperature. During the examination, effects of different transfer functions and number of neurons in hidden layer are investigated to find the optimum network architecture. Besides, statistical error analysis considering the results obtained from available correlations and group contribution methods and proposed neural network is performed to reliably check the feasibility and accuracy of the proposed method. Respect to the obtained results, it can be concluded that the proposed neural network consisted of three layers namely, input, hidden and output layers with 22 neurons in hidden layer was the optimum ANN model. Generally, the proposed model enables to correlate the thermal conductivity of normal and aromatic hydrocarbons with absolute average relative deviation percent(AARD), mean square error(MSE), and correlation coefficient(R^2) of lower than 0.2%, 1.05 × 10^(-7) and 0.9994, respectively.

Electrophysiological evaluation in 4 patients with diabetic pseudotabes

BACKGROUND： Researches on diabetic nervous system lesion are mainly focus on peripheral nerve and vegetative nerve, so there are few investigations on diabetic pseudotabes. OBJECTIVE： To investigate the electrophysiological examinations on the diagnosis of diabetic pseudotabes. DESIGN： Case study. SETTING： Department of Electrophysiology and Department of Neurology, Zhongshan Hospital Affiliated to Xiamen University. PARTICIPANTS： A total of 4 patients with type 2 diabetes mellitus, including 3 males and 1 female aged from 50 to 72 years, were selected from Department of Neurology, Zhongshan Hospital Affiliated to Xiamen University from March 2002 to February 2005. All accepted subjects met the modified diagnostic criteria of diabetes mellitus, which was set by American Diabetes Mellitus Association （ADA） in 1997. Otherwise, the subjects had typical symptoms and physical signs of spinal posterior funiculus damage. However, patients with spinal cord lesion which was caused by other factors were excluded. All accepted subjects provided the confirmed consent. METHODS： Nicolet NT electromyography （EMG）/evoked potential meter （made in the USA） was used to detect spinal cord conduction velocity （SCCV）, somatosensory evoked potential （SEP） of lower limbs, motor nerve conduction velocity （MNCV） and sensory nerve conduction velocity （SNCV） of extremities. Determining criteria： Measurements were performed based on the laboratory standards. SCCV, which was less than lower limit of normal value （T2–12： 40–55 m/s, T12–L4： 20–41 m/s, T2–L4： 36–45 m/s）, was regarded as abnormal. SEP value of lower limbs： P40, P60 and PF, which were more than standard deviation of normal value （x — ＋2.5）, were regarded as the abnormality. Normal value of P40, P60 and PF latencies （x —±s） in this study： P40, P60 and PF in males were （37.6±1.9） ms, （59.8±3.9） ms and （7.6±0.9） ms, respectively; meanwhile, those in females were （35.5±1.7） ms, （55.2±2.7） ms and （6.3±0.7） ms, respectively. MNCV and SNCV, which were less than 50 m/s in upper limbs and 40 m/s in lower limbs, were regarded as the abnormality. MAIN OUTCOME MEASURES： Electrophysiological examinations. RESULTS： All 4 patients with type 2 diabetes mellitus were involved in the final analysis. ① SCCV： Among 4 patients, SCCV of three patients was decreased in T2–12, T12–L4 and T2–L4, and that of the other one was decreased in T2–12 and T2–L4; however, SCCV in T12–L4 was normal. There was significant difference as compared with normal value （P 〈 0.01）. ② SEP of lower limbs： SEP values of lower limbs were abnormal in all 4 patients. Among them, P40, P60 and PF latencies of two patients were delayed; P40 of one patient was delayed and PF was not drained out; P40 and P60 of the last one were delayed and PF was normal. ③ MNCV and SNCV： The MNCV and SNCV were normal in one patient and abnormal in three patients. The results demonstrated that MNCV and SNCV of extremities decreased; especially, sensory nerve action potential （SNAP） of both lower extremities of one patient were not drained out. CONCLUSION： Detections of SCCV, SEP of lower limbs, MNCV and SNCV of extremities are helpful to investigate whether peripheral nerve and deep sensory passage are damaged or not and determine whether deep sensory damage is caused by peripheral nerve and spinal posterior funiculus.

Exploratory use of ultrasound to determine whether demyelination following carpal tunnel syndrome co-exists with axonal degeneration

Carpal tunnel syndrome （CTS） accompanied by secondary axonal degeneration cannot be clearly dis- criminated using the current cross-validated ultrasound severity classification system. This study aimed at exploring cut-off values of ultrasound parameters, including wrist cross-sectional area （W-CSA）, wrist perimeter （W-P）, ratio of cross-sectional area （R-CSA） and perimeter （R-P）, changes of CSA and P from wrist to one third distal forearm （△CSA＆AP） for differentiation. Seventy-three patients （13 male and 60 female） were assigned into group A （demyelination only, n = 40） and group B （demyelination with secondary axonal degeneration, n = 33） based on the outcomes of nerve conduction studies （NCS）. Receiver Operative Characteristics （ROC） curves were plotted to obtain sensitivity, specificity, and accuracy of cut- off values for all the ultrasound parameters. The overall identified cut-off values （W-CSA 12.0 mm2, W-P 16.27 mm, R-CSA 1.85, R-P 1.48, △CSA 6.98 mm2, △P 5.77 mm） had good sensitivity （77.1-88.6%）, fair specificity （40-62.2%） and fair-to-good accuracy （0.676-0.758）. There were also significant differences in demographics （age and severity gradation, P 〈 0.001）, NCS findings （wrist motor latency and conduction velocity, P 〈 0.0001; wrist motor amplitude, P 〈 0.05; distal sensory latency, P 〈 0.05; sensory amplitude, P 〈 0.001） and ultrasound measurements （W-CSA, W-P, R-CSA, R-P, △CSA＆△P, P 〈 0.05） between groups. These findings suggest that ultrasound can be potentially used to differentiate demyelinating CTS with sec- ondary axonal degeneration and provide better treatment guidance.

Pulsed electrical stimulation protects neurons in the dorsal root and anterior horn of the spinal cord after peripheral nerve injury

Most studies on peripheral nerve injury have focused on repair at the site of injury, but very few have examined the effects of repair strategies on the more proximal neuronal cell bodies. In this study, an approximately 10-mm-long nerve segment from the ischial tuberosity in the rat was transected and its proximal and distal ends were inverted and sutured. The spinal cord was subjected to pulsed electrical stimulation at T10 and L3, at a current of 6.5 m A and a stimulation frequency of 15 Hz, 15 minutes per session, twice a day for 56 days. After pulsed electrical stimulation, the number of neurons in the dorsal root ganglion and anterior horn was increased in rats with sciatic nerve injury. The number of myelinated nerve fibers was increased in the sciatic nerve. The ultrastructure of neurons in the dorsal root ganglion and spinal cord was noticeably improved. Conduction velocity of the sciatic nerve was also increased. These results show that pulsed electrical stimulation protects sensory neurons in the dorsal root ganglia as well as motor neurons in the anterior horn of the spinal cord after peripheral nerve injury, and that it promotes the regeneration of peripheral nerve fibers.

Peripheral Nerve Discharge Elicited by Manual Acupuncture at Zusanli (ST 36) Regulates Blood Pressure in Anesthetized Rats

Objective： To investigate target organ response by recording mean arterial blood pressure （MAP） fluctuation corresponding to nerve-tract discharges from the nerve innervating acupoint of Zusanli （ST 36） in the hind limb evoked by MA in anesthetized rats. Methods： Male SD rats anesthetized with chloral hydrate were randomly divided into 3 groups which were treated with manual acupuncture （MA）, injection of lidocaine followed by MA and injection of normal saline （NS） followed by MA, respectively. The right carotid artery was canulated for persistent measurement of the blood pressure and meanwhile nerve discharges from the nerve-tract were recorded for analysis with amplitude spike counts for every 5 s. Results： The results showed that there were significant nerve discharges recorded from the nerve-tract when applying MA at Zusanli （ST 36） and simultaneous decrease in the MAP, while there was no response when inserting a needle into the Zusanli （ST 36） without manipulation （P〈0.05）. Furthermore, the reduction of MAP during MA could be completely abolished after blockade of peripheral nerve discharges with an injection of lidocaine into the tissue around Zusanli （ST 36） but not with that of normal saline （NS）. Conclusion： These results indicate that MA at Zusanli （ST 36） can elicit the peripheral nerve discharges from the nerve innervating the acupoint; such kind of nerve discharges may contain acupuncture signal regulating blood pressure via somato-cardiovascular reflex.

Clinical Observation of Warm Acupuncture in Treating Diabetic Peripheral Neuropathy

Objective： To observe the clinical efficacy of warm acupuncture in the treatment of diabetic peripheral neuropathy and its effects on the conduction velocity of the tibial nerve and common fibular nerve. Methods： Fifty-two subjects were evenly randomized into two groups and treated by conventional therapy; in addition, the control group was given mecobalamin injection at 500μg, once a day for four weeks, and treatment group was given warm acupuncture, 6 times a week for 4 weeks. The clinical efficacy and the conduction velocity of the tibial nerve and common fibular nerve were observed and compared between the two groups. Results： After four-week treatments, the total effective rate was 88.5% in the treatment group and 61.5% in the control group, with a higher rate in the treatment group than in the control group （P〈0.05）; the conduction velocity of tibial nerve and common fibular nerve was higher in both groups （P〈0.05）, with higher conduction velocity in the treatment group than in the control group （P〈0.05）. Conclusion： Warm acupuncture is quite effective to treat diabetic peripheral neuropathy and to improve nerve velocity.

Study of Neuropathways of Acupuncture Effect on Functional Regulation and Disease Treatment

Objective： To reveal the neuropathways of acupuncture effect on regulation of autonomic functions, treatment of diseases and the relationship between treating acupoint and certain target tissue or organ. Methods： it is reviewed for the authors＇ studies of characteristics of afferent nerve response, somato-sympathetic reflex （one of the somato-autonomic reflexes） and glutamate derived central modulation, target tissue and organ responses to somatic stimulation of acupuncture or electrical shock in rats and mice. Results and Conclusion： An electrical discharge from the nerve afferent serving Zusanli （ST 36） was recorded by applying manual acupuncture or electroacupuncture to Zusanli （ST 36）. Such process could be replaced by applying electric shock directly to the afferent nerve assumingly. Somatic electrical stimulation of the afferent nerve e.g. tibia nerve can reflexively elicit an electrical discharge from autonomic efferent nerve e.g. sympathetic nerve that is defined as somato-sympathetic reflex. The reflex can be modulated by an excitatory neurotransmitter of glutamate in the central pathways. On the other hand, somatic stimulation of Zusanli （ST 36）, etc. by electroacupuncture showed that there were inhibitory modulation of somatic sensory input from target tissue of the inflammatory pain in the hind paw of the mouse and visceral sensory input from target organ of the colorectum hyperagesia in the irritable bowel syndrome （IBS） rat. Spinal GABA and NMDA receptors were proved to be involved in the former and latter processes, respectively.

Moxibustion Therapy on Diabetic Peripheral Neuropathy in Rats for the Peripheral Neuroprotection

Objective： To study the mechanism of moxibustion therapy on diabetic peripheral neuropathy for the peripheral neuroprotection. Methods： The DPN model was induced by intraperitoneal injection with streptozotocin （STZ）. The rats were given moxibustion at the acupoint Yishu （Extra） and the acupoint Zusanli （ST 36）. The treatment was carried out once a day and 15 minutes per acupoint, lasting for 56 d in total. The clinical effect of moxibustion was evaluated by detecting blood sugar, urine sugar, body weight and dietary intakes, as well as nerve conduction velocity with neuroelectrophysiological method. The structure variation of sciatic nerve was observed by HE staining and light microscopy, and the level of NGF in the sciatic nerve was determined by ELISA. Results： Compared with the model group, the plasma glucose was significantly lower in the moxibustion group （P〈0.01）, with significantly faster nerve conduction velocity （P〈0.01）, more notably changes in pathological appearance （P〈0.01） and higher level of nerve growth factor （NGF） （P〈0.01）. Conclusion： Moxibustion coUld improve the symptom and signs of peripheral neuropathy in rat models with DPN, which may relate to the increased NGF and enhanced peripheral nerve protection.

Pathogenesis and electrodiagnosis of cubital tunnel syndrome

Background Cubital tunnel syndrome is a well-recognized clinical condition and is the second most common peripheral compression neuropathy. This study was designed to investigate the causes of cubital tunnel syndrome by surgical means and to assess the clinical value of the neurophysiological diagnosis of cubital tunnel syndrome. Methods Twenty-one patients (involving a total of 22 limbs from 16 men and 5 women, aged 22 to 63, with a mean age of 49 years) with clinical symptoms and signs indicating a problem with their ulnar nerve underwent motor conduction velocity examinations at different sites along the ulnar nerve and examinations of sensory conduction velocity in the hand, before undergoing anterior transposition of the ulnar nerve.Results Electromyographic abnormalities were seen in 21 of 22 limbs [motor nerve conduction velocity (MCV) range (15.9-47.5) m/s, mean 32.7 m/s] who underwent motor conduction velocity examinations across the elbow segment of the ulnar nerve. Reduced velocity was observed in 13 of 22 limbs [MCV (15.7-59.6) m/s, mean 40.4 m/s] undergoing MCV tests in the forearms. An absent or abnormal sensory nerve action potential following stimulation was detected in the little finger of 14 of 22 limbs. The factors responsible for ulnar compression based on observations made during surgery were as follows: 15 cases involved compression by arcuate ligaments, muscle tendons, or bone hyperplasia; 2 involved fibrous adhesion; 3 involved compression by the venous plexus or a concurrent thick vein; 2 involved compression by cysts. Conclusions Factors inducing cubital tunnel syndrome include both common factors that have been reported and rare factors, involving the venous plexus, thick veins, and cysts. Tests of motor conduction velocity at different sites along the ulnar nerve should be helpful in diagnosis cubital tunnel syndrome, especially MCV tests indicating decreased velocity across the elbow segment of the ulnar nerve.