老年人体外大电极起搏临床应用体会

老年人体外大电极起搏临床应用体会林小冰，吕心阳，杨榕，蔡诗演关键词大电极，体外起搏我院从１９９０年开始使用ＤＭＳ７５０大电极体外起搏器，在老年危重病人抢救中取得较好的效果，现将临床应用体会报告如下。１资料和方法１．１一般情况男性１４例，女性２例，年龄...

体外大电极起搏的临床价值(附15例报告)

1993年以来我科采用美国Medical Research Laboratories简称(MRL)公司生产的心电监护～起搏器及随带的体外大电极为15例濒危患者做了体外临时心脏起搏，取得了较为满意的效果，特报告如下。

30MVA锰硅合金电炉的电极维护

介绍了大电炉自焙电极在新开炉及锰硅合金生产过程中遵循的原则和解决问题的途径。通过选择合适的电极糊、调整炉料渣型及选择适宜的供电制度等技术措施,可避免电极事故的发生,从而使生产正常进行。

Simulation of a Monolithic Integrated CMOS Preamplifier for Neural Recordings

A monolithic integrated CMOS preamplifier is presented for neural recording applications. Two AC-coupied capacitors are used to eliminate the large and random DC offsets existing in the electrode-electrolyte interface. Diode-connected nMOS transistors with a negative voltage between the gate and source are candidates for the large resistors necessary for the preamplifier. A novel analysis is given to determine the noise power spectral density. Simulation results show that the two-stage CMOS preamplifier in a closed-loop capacitive feedback configuration provides an AC in-band gain of 38.8dB,a DC gain of 0,and an input-referred noise of 277nVmax, integrated from 0. 1Hz to 1kHz. The preamplifier can eliminate the DC offset voltage and has low input-referred noise by novel circuit configuration and theoretical analysis.

等离子体平板背光源单元放电特性的研究

采用粒子网格-蒙特卡罗碰撞(P IC-M CC)方法对等离子体平板背光源单元的放电过程进行了数值模拟,获得了放电过程中各带电粒子在空间区域的分布以及各区域的形成和性质,并结合模拟结果,详细分析了等离子体平板背光源单元的放电特性。结果表明,放电单元采用大电极间距可获得正柱区放电,正柱区的形成是正离子在阴极鞘层区不断积累将电位抬高所致。通过增加电极间距以增加正柱区的长度,可以有效地改善放电特性,从而提高背光源的发光效率。

音频电疗法治疗前列腺增生症

我科自1983年起利用音频电疗法治疗前列腺增生症,取得显著的效果。在抽查的550例中年龄最小者38岁,最大者86岁。1.音频电疗方法 操作方法与治疗其它疾病时相同,但注意了以下诸项:1.1 电极 选用导电性能良好的铜片、铝片等。分大、小两种电极。大电极为(10cm×8cm),小电极为(5cm×4cm)。1.2 放置的位置 有对置法和并置法两种。对置法:用大电极,分别置于腰骶部和小腹部(耻骨联合上缘)。

Hydrogen bubble fiotation of fine minerals containing calcium

One characteristic of electro-flotation is the presence of micro bubbles that are well known for improving the flotation performance of fine particles. An electro-flotation method was studied with fine scheelite and fluorite particles sized into three different fractions. Experiments were performed in a modified Hallimond tube. We investigated the effects of gas holdup, particle size, and different mesh electrode apertures on mineral recovery. Flotation results show that two size fractions show increased flotation recovery as the gas holdup increases. For the sized scheelite and fluorite, the flotation effect is diverse for different sizes of the cathode aperture. Pictures of the bubbles taken by a high speed CCD were used to determine the hydrogen bubble size distribution generated as a function of collector, current density, and electrode size. The diameters of the hydrogen bubbles ranged from 12 to 117μm in alkaline conditions.

Design of Photoelectric Detection Circuit in Linear Measuring System

The structure,equivalent circuit,noise sources of silicon photodiode are analyzed.In order to improve the measuring linearity,we must choose the silicon photodiode with a large R d,small R s and I 0 and under an operation state of output short-circuit.We must let the operation amplifier work in the current-voltage transfer form.Also we analyzed the effects of the input noise voltage,the input noise current,the input offset voltage,the input offset current of the operation amplifier and the noises of the silicon photodiode on the combined circuit of the operation amplifier with the silicon photodiode.Considering these factors,we can design the detective circuit with high response,sensitivity,stability,linearity and SNR .

Separation and Manipulation of Rare-earth Oxide Particles by Dielectrophoresis

A challenge in chemical engineering is the separation and purification of rare-earth elements and their compounds. We report the design and manufacture of a dielectrophoresis(DEP) microchip of microelectrode arrays. This microchip device is constructed in order to use DEP to capture micro-particles of rare-earth oxides in petro-leum. Dielectrophoretic behavior of micro-particles of rare-earth oxides in oil media is explored. The dielectropho-retic effects of particles under different conditions are investigated. It is showed that the prepared microchip is suit-able for use in the investigation of dielectrophoretic responses of the rare-earth oxides in oil media. The factors such as frequency,particle size and valence of rare-earth metal are discussed. When the frequency is fixed,the transla-tion voltage decreases as particle size increases. Lower frequencies are more effective for manipulation of inorganic particles in oil media. Particles of the same rare-earth oxide with different size,as well as particles of different rare-earth oxides,are captured in different regions of the field by regulating DEP conditions. This may be a new method for separation and purification of particles of different rare-earth oxides,as well as classification of particles with different size.

Preparation of Ni nanoparticles plating by electrodeposition using reverse microemulsion as template

Ni nanoparticles plating was prepared in reverse microemulsion. The deposition was carried out through the Brownian motion of water pools in the reverse microemulsion and the adsorption of water pools on the electrode surface. Effects of electrolytic parameters on the size of Ni particles were studied. The performances of hydrogen evolution and hydrogen storage of the Ni nanoparticles plating electrode were also investigated. The results indicate that the size of Ni nanoparticles decreases with the increase of Ni2+ concentration and the decrease of current density. The electrochemical activity of Ni nanoparticles plating electrode is much higher than that of bulk Ni electrode.

Threshold Current Characteristics of Intracavity-contacted Vertical-cavity Surface-emitting Laser

Threshold current characteristics of intracavity-contacted oxide-confinedvertical-cavity surface-emitting laser had been investigated in detail. Threshold currentcharacteristics not only were depended on the size of oxide-aperture, but also were also stronglyaffected by the mismatch of its lasing mode and gain peak. For the same degree detuning of the gainpeak and lasing mode at room temperature, the threshold current was approximately proportional tothe square of the oxide-aperture diameter of above 5 μm. For the same oxide-aperture device, thelarger the detuning degree of the lasing mode shifted to the shorter wavelength of the gain peak atroom temperature was, the lower the minimum threshold current was. The wavelengths of the lasingmode and gain peak were ± N X 10 nm detuning at 300 K, The temperature of the minimum thresholdcurrent was changed to be about ± N X 40 K(N real number). The calculated results were consistentwith the experimental ones.

Analysis of Electrogastrograms of Elderly Gastrectomized Subjects by Using Maximum Lyapunov Exponent

Not much data are available regarding the electrical activity in the stomachs and intestines of elderly gastrectomized patients The purpose of this study was to determine the feasibility of using a complex dynamic method to analyze the electrogastrograms （EGGs） of healthy young, healthy elderly, and gastrectomized elderly male individuals. The authors analyzed the EGGs by using the maximum Lyapunov exponent （MLE）, which is one of the indices of the chaotic characteristics of time series. Significant differences were observed between the MLEs estimated from the, EGGs of the young and elderly individuals for most of the temporal intervals. The authors＇ data indicate that the EGGs of elderly gastrectomized subjects might be distinguished from the EGGs of healthy elderly individuals on the basis of the MLE distribution.

Research on the variable speed system of large power alternating current motor

The development status of the variable speed system of large power AC(alternating current)motor drive in China is introduced.The large power AC drive fed by AC-AC converters(cycloconverters)has developed greatly,and some innovations on the theory and engineering technique have been realized.They have been applied to rolling mills,mine hoists,and so on,and remarkable economic and social benefit has been achieved.The development of AC drive fed by large power IGCT(integrated gate commutated thyristors)AC-DC-AC converter is also introduced.It has excellent performance and reliable operation,and has been used in traction.

Typical Surface Seasonal Circulation in the Indian Ocean Derived from Argos Floats

This study investigates the surface circulation in the Indian Ocean using Argos float data over the period 1979-2011.The Argos observations manifest some new phenomena.The climatological annual mean circulation shows that the surface current becomes much stronger after turning around in shore in the western Indian Ocean.In the tropical Indian Ocean,the Great Whirl(GW) to the east of Somalia develops quickly in spring(April-May) as the monsoon reverses to move northward,becoming strongest in summer(June-September) and disappearing in autumn(October-November).The west end of the Agulhas retroflection can reach 18°E,and it exhibits a seasonal variation.At approximately 90°E,the Agulhas Return Current combines with the eastward South Atlantic Current and finally joins the Antarctic Circumpolar Current.

Study on intervention mechanism of acupuncture for neuron abnormal neural coding in visual cortex area 17 of monocular deprivation rats

Objective： To investigate the electrophysiological mechanism of acupuncture for the visual cortex plasticity during the sensitive period.Methods： Fifty 2-week-old Wistar rats were randomly divided into a blank control group, a model group, an early-stage acupuncture group, a middle-stage acupuncture group and a late-stage acupuncture group, 10 rats in each group.Monocular deprivation amblyopia models were prepared in rats except those in the blank control group by unilateral eyelid suture. After successful modeling, no treatment was applied to the rats in the model group. Rats in each acupuncture group were treated with acupuncture at bilateral Jingming（BL 1）, Cuanzhu（BL 2）, Fengchi（GB 20） and Guangming（GB 37）, started from the 3rd day, 12 th day or 21 st day after modeling separately, once a day, for a total of 9 d treatment. The neuronal discharge frequency and action potential inter-spike interval（ISI） in the rat visual cortex area 17 of each group were measured by multi-channel microelectrode array nerve signal technique.Results： The discharge number of neurons in the visual cortex of the model group was significantly lower than that in the blank control group（P〈0.05）. After treatment, the discharge numbers in the early-stage acupuncture group and the middle-stage acupuncture group were significantly higher than that in the model group（P〈0.05）. There was no significant difference in the discharge numbers between the late-stage acupuncture group and the model group（P〉0.05）. The discharge number in the middle-stage acupuncture group was lower than that in the early-stage acupuncture group（P〈0.05）, and the discharge number of the late-stage acupuncture group was lower than that in the middle-stage acupuncture group（P〈0.05）. The ISI sequences of the visual cortex neurons were mainly distributed under 0.3 s in the blank control group, under 15 s in the model group, under 1 s in the early-stage acupuncture group, under 4 s in the middle-stage acupuncture group, and under 10 s in the late-stage acupuncture group, divergent in each group.Conclusion： The neuronal coding appears abnormality in the visual cortex area 17 of monocular deprivation rats, indicating that there is a plasticity change in the visual cortex neurons during the sensitive period. Acupuncture has a significant effect on the abnormal neural coding. The therapeutic efficacy is closely related to the stage to start the treatment. Early stage treatment in the sensitive period is the key to achieving the good efficacy.

Pole-Based Approximation of the Fermi-Dirac Function

Two approaches for the efficient rational approximation of the Fermi-Dirac function are discussed： one uses the contour integral representation and conformal real〉 ping, and the other is based on a version of the multipole representation of the Fermi-Dirac function that uses only simple poles. Both representations have logarithmic computational complexity. They are of great interest for electronic structure calculations.

Large field emission current and density from robust carbon nanotube cathodes for continuous and pulsed electron sources

Highly adhesive cold cathodes with high field emission performance are fabricated by using a screen-print- ing method. The emission density of carbon nanotube （CNT） cold cathode reaches 207.0 mA cm-2 at an electric field of 4.5 Vμm-1 under continuous driving mode, and high peak current emission of 315.8 mA corresponding to 4.5 A cm 2 at the electric field of 10.3 V μm-1 under pulsed driving mode. The emission patterns of the cold cathodes are of excellent uniformity that was revealed by vivid luminescent patterns of phosphor coated transparent indium tin oxide （ITO） an- ode. The cold cathodes also exhibit highly stable emission under continuous and pulsed driving modes. The high adhe- sion of CNTs to molybdenum substrates results in robust cold cathodes and is responsible for the high field emission performance. This robust CNT emitter could meet the operating requirements of continuous and pulsed electron sources, and it provides promising applications in various vacuum- micro/nanoelectronic devices.

Differential effects of long and short train theta burst stimulation on LTP induction in rat anterior cingulate cortex slices:Multi-electrode array recordings

Objective There is substantial evidence supporting the notion that the anterior cingulate cortex （ACC） is an important limbic structure involved in multiple brain functions such as sensory perception, motor conflict monitoring, memory, emotion and cognition. It has been shown that long term potentiation （LTP） is an important synaptic model of neural plasticity in the ACC, however, little is known about the spatiotemporal properties of ACC at network level. The present study was designed to see the LTP induction effects across different layers of the ACC by using different conditioning stimuli （CS） protocols. Methods A unique multi-electrode array recording technique was used in the acutely-dissociated ACC slices of rats. Long and short train theta burst stimulation （TBS） paradigms were applied in layer V-VI as the CS and the LTP induction effects were compared across different layers of the ACC. Briefly, both long and short train TBS are composed of bursts （4 pulses at 100 Hz） with a 200 ms interval, however, the former （TBS1） was with 10 trains and the latter （TBS2） was with 5 trains. After test stimulation at layer V-VI in the ACC, network field potentials （FPs） could be simultaneously recorded across all layers of the ACC. Results The waveforms of FPs were different across different layers. Namely, positive-going waveforms were recorded in layer I and negative-going waveforms were recorded in layers V-VI, in contrast, complex waveforms were localized mainly in layers II-III. Following application of two CS protocols, the induction rate of LTP was significantly different between TBS 1 and TBS2 regardless of the spatial properties. TBS1 had more than 60% success, while TBS2 was less than 25% in induction of LTP. Moreover, both the 2 CS protocols could induce LTP in layers II-III and layers V-VI without layer-related difference. However, no LTP was inducible in layer I. Conclusion The present findings indicate that stimulation protocols may, at least in part, account for a large portion of variations among previous LTP studies, and hence highlight the importance of selecting the best LTP induction protocol when designing such experiments. Moreover, the present results demonstrate the prominent superiority of multi-electrode array recording in revealing the network properties of synaptic activities in the ACC, especially in comparing the spatiotemporal characteristics between different layers of this structure.