青藏高原人体脉搏测量及几种脉图对比分析

脉搏信息反映人体内部各器官的健康状况,利用PVDF压力传感器并垫一水囊间接接触法拾取脉搏信息,通过调理放大硬件电路对脉搏信号进行调理放大,借助虚拟仪器软件LabVIEW在PC机上架构虚拟脉搏测试系统,测试并采集了青藏高原地区大量不同人群的脉搏信息数据,给出了几种具有地域特征的脉图,并结合中医脉诊理论进行了对比分析。     

The role of GABAergic inhibition in shaping directional selectivity of bat inferior collicular neurons determined with temporally patterned pulse trains

This study examined the role of GABAergic inhibition in shaping directional selectivity of neurons in the inferior colliculus of the big brown bat, Eptesicus fuscus. When determined with temporally patterned pulse trains at different pulse repetition rates, 93 inferior colliculus neurons displayed three types of directional selectivity curves. A directionally selective curve always showed a maximum to a certain azimuthal angle (the best angle). A hemifield curve showed a maximum to a range of contralateral azimuthal angles. A non-directional curve did not show a maximum to any particular azimuthal angles. Directional selectivity curves of 42% neurons changed from hemifield or non-directional to directionally selective and the best angles of 16-21% neurons shifted toward the midline with increasing pulse repetition rate of pulse trains. Directional selectivity curves of most (74%) neurons that discharged impulses to each pulse of a pulse train also became sharper with increasing pulse repetition rate of pulse trains. Bicuculline application produced more pronounced broadening of directional selective curves of inferior colliculus neurons at higher than at lower pulse repetition rates. As a result, pulse repetition rate-dependent directional selectivity of inferior colliculus neurons was abolished. Possible mechanisms and biological significance of these findings are discussed.     

Effects of various electric fields on the fusion and in vitro development of mouse two-cell embryos

This study was undertaken to examine the effects of various electric fields such as alternating current (a.c.) voltage, fusion pulse strength, pulse duration, pulse number and electrode geometry on blastomere fusion and developmental rates of mouse two-cell embryos. The a.c. voltages (6 and 12 V/mm) did not affect the fusion and developmental rates. High fusion and developmental rates were obtained when pulse strengths of 1.0 to 2.5 kV/cm, pulse durations of 30 to 90 mu sec and pulse numbers of 1 to 6 were applied using a wire chamber. Comparison of electrode geometries showed that fusion rates were similarly high (93 to 98%) when pulse strengths of 1.0 to 2.5 kV/cm were applied, regardless of the electrode geometry. However, significantly lower developmental rates were observed in a rectangular chamber compared with those in a wire chamber, except when the pulse strength was 1.0 kV/cm. It was further observed that in a rectangular chamber, the developmental rate decreased with increasing pulse strength from 1.0 to 2.0 and 2.5 kV/cm. The results of this study indicate that by using a wire chamber, electric fields can be successfully applied across a relatively wide range of pulse strength, duration and number to provide sufficiently high fusion and subsequent developmental rates. The fusion conditions did, however, vary with chambers of different electrode geometries.     

Temporally patterned pulse trains affect duration tuning characteristics of bat inferior collicular neurons

 This study examines the effect of temporally patterned pulse trains on duration tuning characteristics of inferior collicular neurons of the big brown bat, Eptesicus fuscus, under free-field stimulation conditions. Using a 50% difference between maximal and minimal responses as a criterion, the duration tuning characteristics of inferior collicular neurons determined with pulse trains of different pulse durations are described as band-pass, long-pass, short-pass, and all-pass. Each band-pass neuron discharged maximally to a specific pulse duration that was at least 50% larger than the neuron's responses to a long- and a short-duration pulse. In contrast, each long- or short-pass neuron discharged maximally to a range of long- or short-duration pulses that were at least 50% larger than the minimal responses. The number of impulses of an all-pass neuron never differed by more than 50%. When pulse trains were delivered at different pulse repetition rates, the number of short-pass and band-pass neurons progressively increased with increasing pulse repetition rates. The slope of the duration tuning curves also became sharper when determined with pulse trains at high pulse repetition rates. Possible mechanisms underlying these findings are discussed. Accepted: 25 August 1999     

Assessment of pulse rate variability by the method of pulse frequency demodulation

Background  

Due to its easy applicability, pulse wave has been proposed as a surrogate of electrocardiogram (ECG) for the analysis of heart rate variability (HRV). However, its smoother waveform precludes accurate measurement of pulse-to-pulse interval by fiducial-point algorithms. Here we report a pulse frequency demodulation (PFDM) technique as a method for extracting instantaneous pulse rate function directly from pulse wave signal and its usefulness for assessing pulse rate variability (PRV).     

Coevolution of male mating signal and female preference during early lineage divergence of the Hawaiian cricket, Laupala cerasina

Sexual selection is a powerful evolutionary force shaping mate choice phenotypes, initiating phenotypic shifts resulting in (or reinforcing) population divergence and speciation when such shifts reduce mating probabilities among divergent populations. In the Hawaiian cricket genus Laupala, pulse rate of male calling song, a conspicuous mating signal, differs among species, potentially behaving as a speciation phenotype. Populations of the widespread species Laupala cerasina show variation in pulse rate. We document the degree of population differentiation in three features of calling song: pulse rate, pulse duration, and carrier frequency. All show significant population differentiation, with pulse rate showing the greatest heterogeneity. A Mantel test found no relationship between geographic distance and pulse rate divergence, indicating that a simple model of greater divergence with increasing distance cannot explain the observed pattern of differentiation. We demonstrate that female preference functions for pulse rate are unimodal, and that preference means show significant differentiation among populations. Furthermore, estimates of pulse rate preference correlate significantly with mean pulse rates across populations, indicating song and preference coevolve in a stepwise manner. This correlated divergence between signal and preference suggests that sexual selection facilitates the establishment of sexual isolation, reduced gene flow, and population differentiation, prerequisites for speciation.     

Antagonistic action of low-fluence and high-irradiance modes of response of phytochrome on germination and beta-mannanase activity in Datura ferox seeds

Seed germination is often induced by a pulse of red light perceived by phytochrome and cancelled by a subsequent pulse of far-red light. When the pulse of red light is followed by several hours of darkness, a pulse of far-red light is no longer effective and prolonged far-red is necessary to block germination. The aim was to investigate whether the red light pulse and prolonged far-red light act on the same or different processes during germination of Datura ferox seeds. Forty-five hours after the inductive red light pulse, germination could not be blocked by one pulse or six hourly pulses of far-red light, but was significantly reduced by 6 h of continuous far-red light. The pulse of red light increased embryo growth potential and the activities of beta-mannanase and beta-mannosidase extracted from the micropylar region of the endosperm. Continuous far-red light had no effect on embryo growth potential or beta-mannosidase activity, but severely reduced the activity of beta-mannanase. The effect of far-red light had the features of a high-irradiance response of phytochrome. Both germination and beta-mannanase activity were restored by a pulse of red light given after the end of the continuous far-red treatment. It is concluded that the low-fluence response and the high-irradiance response modes of phytochrome have antagonistic effects on seed germination and that the control of beta-mannanase activity is one process where this antagonism is established.     

Interaction between the effects of light pulses of different chromatic content on Hydra attenuata and H. magnipapillata

The pattern of Hydra periodic shortening-elongation behaviour can be modified by photic stimulation. The response time between the end of a pulse stimulus and the beginning of the next body shortening event is a function of: 1) the polarity of the pulse; 2) the intensity of the pulse, 3) the phase of application of the pulse during a shortening-elongation period, 4) the wavelength of the pulse, 5) the chromatic composition of the background illumination. The combined effects of pulse light stimuli of different wavelength applied either simultaneously or in immediate sequence are reported here. The results give some insight into the possible mechanism of phototransduction.     

Pulse Rate Criteria for Determining the Energy Cost of Exercise

From the pulse rate curve taken during exercise and recovery from highly qualified sportsmen performing a bicycle exercise test at a maximum workload, the work pulse sum, pulse debt, and pulse cost were calculated. Plots of these indices versus the time to exhaustion and versus the relative exercise workload were identical to the respective plots of oxygen consumption during exercise, oxygen debt, and oxygen requirement. The exercise pulse cost can serve as a criterion for quantifying physical workloads.     

Millisecond measurement of transport during and after an electroporation pulse.

Electroporation involves the application of an electric field pulse that creates transient aqueous pathways in lipid bilayer membranes. Transport through these pathways can occur by different mechanisms during and after a pulse. To determine the time scale of transport and the mechanism(s) by which it occurs, efflux of a fluorescent molecule, calcein, across erythrocyte ghost membranes was measured with a fluorescence microscope photometer with millisecond time resolution during and after electroporation pulses several milliseconds in duration. One of four outcomes was typically observed. Ghosts were: (1) partially emptied of calcein, involving efflux primarily after the pulse; (2) completely emptied of calcein, involving efflux primarily after the pulse; (3) completely emptied of calcein, involving efflux both during and after the pulse; or (4) completely emptied of calcein, involving efflux primarily during the pulse. Partial emptying, involving significant efflux during the pulse, was generally not observed. We conclude that under some conditions transport caused by electroporation occurs predominantly by electrophoresis and/or electroosmosis during a pulse, although under other conditions transport occurs in part or almost completely by diffusion within milliseconds to seconds after a pulse.     

The hour of transition into luteolysis in horses and cattle: a species comparison

Hourly blood sampling in both horses and cattle indicate that the transition between the end of preluteolysis and the beginning of luteolysis occurs within 1 h, as manifested by a change in progesterone concentrations. Each species presents a separate temporality enigma on the relationship between pulses of a prostaglandin (PG) F2α metabolite (PGFM) and the hour of the progesterone transition. In horses, relatively small pulses of PGFM occur during preluteolysis (before transition) and at transition. Oxytocin, but not estradiol, increases and decreases concomitantly with the small PGFM pulse at transition but not with previous pulses and may account for the initiation of luteolysis during the small PGFM pulse. In cattle, the last PGFM pulse of preluteolysis occurs hours before transition (e.g., 4 h), and the next pulse occurs well after transition (e.g., 9 h); unlike in horses, a PGFM pulse does not occur at transition. During the last PGFM pulse before transition, progesterone concentration decreases during the ascending portion of the PGFM pulse. Concentration then rebounds in synchrony with an LH pulse. The rebound returns progesterone to the concentration before the PGFM pulse. During luteolysis, an LH-stimulated progesterone rebound may occur after the peak of a PGFM pulse, but progesterone does not return to the concentration before the PGFM pulse. A similar LH-stimulated progesterone rebound does not occur in horses, and therefore progesterone fluctuations are more shallow in horses than in cattle.     

A large ephemeral release of nitrogen upon wetting of dry soil and corresponding root responses in the field

To assess changes in soil nutrients, root growth and mycrorrhizal infection in response to rain events, a water pulse was applied to a very dry soil. Wetting of a dry soil in the Great Basin of the Western United States led to a striking pulse of available soil nitrate in a field plot, but available phosphate was not affected. This is the first field demonstration of this phenomenon in the Great Basin as far as we are aware. This pulse was only apparent for a few days, probably due to microbial immobilization of the nitrogen. Root ammonium uptake capacity increased within one day of the water pulse, but new root growth was not apparent until 3 days after the water pulse. Thus, to capture this ephemeral release of nitrogen, enhanced uptake capacity of existing roots was probably more important than development of new roots. Mycorrhizal infection was not affected by the water pulse treatments. However, since the water pulse only affected nitrogen availability and mycorrhizae are generally most effective in facilitating acquisition of less mobile nutrients such as phosphate, mycorrhizae likely do not play an important role in taking advantage of this opportunity provided by the pulse of water.     

Kinetics of transmembrane transport of small molecules into electropermeabilized cells

The transport of propidium iodide into electropermeabilized Chinese hamster ovary cells was monitored with a photomultiplier tube during and after the electric pulse. The influence of pulse amplitude and duration on the transport kinetics was investigated with time resolutions from 200 ns to 4 ms in intervals from 400 μs to 8 s. The transport became detectable as early as 60 μs after the start of the pulse, continued for tens of seconds after the pulse, and was faster and larger for higher pulse amplitudes and/or longer pulse durations. With fixed pulse parameters, transport into confluent monolayers of cells was slower than transport into suspended cells. Different time courses of fluorescence increase were observed during and at various times after the pulse, reflecting different transport mechanisms and ongoing membrane resealing. The data were compared to theoretical predictions of the Nernst-Planck equation. After a delay of 60 μs, the time course of fluorescence during the pulse was approximately linear, supporting a mainly electrophoretic solution of the Nernst-Planck equation. The time course after the pulse agreed with diffusional solution of the Nernst-Planck equation if the membrane resealing was assumed to consist of three distinct components, with time constants in the range of tens of microseconds, hundreds of microseconds, and tens of seconds, respectively.     

高血压患者脉搏波参数与脉搏波传导速度的相关性研究

目的:探讨高血压患者脉搏波参数与脉搏波传导速度的相关性,为从脉图上辨识高血压病及脉搏波参数的拓展应用提供参考。方法:选择2012年6月至2013年6月在北京安贞医院和北京人民医院门诊和住院确诊的原发性高血压患者32例作为实验组,并招募健康成人志愿者29例作为对照组。利用中医四诊合参辅助诊疗仪与皮尺分别采集两组受试者的左侧寸口脉图信息和主动脉至桡动脉的血管长度,计算脉搏波参数及脉搏波传导速度,采用方差分析和皮尔逊简单相关的统计方法分析高血压患者不同的脉搏波参数与其脉搏波传导速度的相关性。结果:与对照组比较,实验组的PWV显著升高,有显著性差异(P0.05)。实验组H2/H1明显高于对照组(P0.05),但H4/H1、T1/T、T2/T比值均显著低于对照组(P0.05),差异均有显著性意义(P0.05)。高血压患者的H2/H1、T1/T、T2/T、H4/H1均与其PWV相关,其中H2/H1与PWV呈显著正相关(P0.05),T1/T、T2/T与PWV呈显著负相关(P0.05),H4/H1与PWV呈一般正相关(P0.05)。结论:高血压患者的脉搏波参数与脉搏波传导速度具有显著相关性,且潮波出现的幅值与脉搏波传导速度有显著正相关;脉搏波上升支和潮波的时值与脉搏波传导速度具有显著负相关,重搏波相对高度与脉搏波传导速度具有一般相关关系,因而可通过脉搏波参数的变化了解高血压患者血管弹性的状态。     

Time course of O2-pulse during various tests of aerobic power.

The purpose of this study was to test the hypothesis that oxygen pulse typically reaches a maximum before maximal oxygen consumption by observing the time course of oxygen pulse throughout exercise to maximal stress and to discern those physiologic variables which might predispose an individual to reach a peak in oxygen pulse before achieving maximal oxygen consumption. Thirty male volunteers ranging in age from 18-25 (X = 20.5) years were recruited for this study. Maximal oxygen uptake was assessed on both bicycle ergometer and treadmill. Based upon the results of the exercise tests, subjects were classified into subgroups as a consequence of whether or not a maximal oxygen pulse or a plateau in oxygen pulse was demonstrated during submaximal exercise. The results indicate that submaximal peaking or at least the achieving of plateau values of oxygen pulse does in fact occur in some but not all indivuals. It was observed that this phenomenon occurs at a relatively high percentage of maximal heart rate and maximal oxygen consumption. It appeared that individuals who demonstrate low heart rates at low-work intensities, high maximal heart rates, and a disproportionate increase in R for a given ventilation are most likely to reach a submaximal peak in oxygen pulse. Oxygen pulse during submaximal exercise appears to provide a good indication of cardiorespiratory fitness.     

Social regulation of electric signal plasticity in male Brachyhypopomus gauderio

In animal communication, the social context that elicits particular dynamic changes in the signal can provide indirect clues to signal function. Female presence should increase the expression of male signal traits relevant for mate-choice, while male presence should promote the enhancement of traits involved in male-male competition. The electric fish Brachyhypopomus gauderio produces a biphasic electric pulse for electrolocation and communication. Pulse amplitude predicts the signaler’s body size while pulse duration predicts circulating androgen levels. Males enhance pulse amplitude and duration when the numbers of males and females increase simultaneously. Here we tested the relative effects of female presence and male presence on male signal enhancement, and whether the size of the male competitor affected this enhancement. We found that male presence drives the enhancement of both pulse amplitude and second phase duration, independently of the size of the male competitor. Female presence induces the enhancement of pulse duration, but not pulse amplitude. These data suggest that males probably attend to information about a competitor’s body size coded by pulse amplitude and attend to aggressiveness coded by a competitor’s pulse duration, both potential predictors of fight outcome. Females may be primarily concerned about information on reproductive condition coded by pulse duration.     

Discriminative control of the vaginal vasomotor response

With use of a discriminative control procedure and operant techniques, women significantly increased their vaginal pulse amplitude (produced vaginal vasodilation) but did not significantly decrease vaginal pulse amplitude (produce vaginal vasoconstriction). Acquisition of vaginal pulse amplitude control was rapid with no significant improvement over trials or the 5 experimental days. Specificity of vaginal pulse amplitude control occurred in relation to the other vasomotor responses, including vaginal blood volume and digital pulse amplitude. Vagnial pulse amplitude changes were not related to somatic-muscular, respiratory, or heart-rate changes. Women who used oral contraceptives were better able to control vaginal pulse amplitude than women who used other forms of birth control. Although the sexual behavior of these two groups and did not differ, women in the latter group tended to be more clitorally oriented.     

High-efficiency gene electrotransfer into skeletal muscle: description and physiological applicability of a new pulse generator

Efficiency and reproducibility of gene electrotransfer depend on the electrical specifications provided by the pulse generator, such as pulse duration, pulse number, pulse frequency, pulse combination, and current intensity. Here, we describe the performances of GET42, a pulse generator specifically designed for gene electrotransfer into skeletal muscle. Expression of beta-galactosidase in the Tibialis anterior muscle of Sprague-Dawley male rats was increased 250-fold by GET42 compared to DNA injection alone. Combination of high and low current intensity pulses further increased transfection efficiency (400-fold compared to DNA injection without electrotransfer). Varying degrees of muscle necrosis were observed after gene electrotransfer. Nevertheless, muscle necrosis was dramatically reduced after optimization of cumulated pulse duration without significant reduction in transfection efficiency. Physiological applicability was illustrated by the analysis of cytochrome c promoter transactivation. In conclusion, GET42 has proven to be a reliable and efficient pulse generator for gene electrotransfer experiments, and provides a powerful mean to study in vivo the regulation of gene expression.     

Loss of material from the retrograde axonal transport system in frog sciatic nerve

Rapid axonal transport was studied in sciatic nerve preparations of the amphibian Xenopus laevis maintained in vitro at 23.0 +/- 0.2 degrees C. A pulse of [35S]methionine-labeled material was allowed to move in the anterograde direction until encountering a lesion, at which a portion of the pulse reversed directions and moved in the retrograde direction. By constricting the nerve during the course of the experiment, it was possible to prevent continuous return of label from the lesion, thus creating a retrogradely moving pulse that contained a defined quantity of radiolabel. Movement of both the anterograde and the retrograde pulse were monitored continuously for up to 24 h using a position-sensitive detector of ionizing radiation. The front and the back edge of the anterograde pulse were found to move at the rates of (mm/day) 179.9 +/- 3.9 (+/- SEM) and 149.9 +/- 5.9, respectively, and the front and the back edge of the retrograde pulse moved at the rates of 155.8 +/- 11.3 and 84.6 +/- 2.9, respectively. By comparison of the quantity of label lost to the stationary phase to the quantity of label calculated to have been present in the anterograde pulse, it was determined that 0.068 +/- 0.009 of the anterograde pulse is lost to each 3.18-mm region of nerve. Comparison of the quantity of label calculated to have been present in the retrograde pulse to that in the anterograde pulse revealed that 0.057 +/- 0.014 of the retrograde pulse is lost to each 3.18-mm region of nerve. It is concluded that protein originating in the cell body and which reverses its direction of transport at a lesion can be lost from the retrograde axonal transport system.     

Discriminative control of the vaginal vasomotor response

With use of a discriminative control procedure and operant techniques, women significantly increased their vaginal pulse amplitude (produced vaginal vasodilation) but did not significantly decrease vaginal pulse amplitude (produce vaginal vasoconstriction). Acquisition of vaginal pulse amplitude control was rapid with no significant improvement over trials or the 5 experimental days. Specificity of vaginal pulse amplitude control occurred in relation to the other vasomotor responses, including vaginal blood volume and digital pulse amplitude. Vaginal pulse amplitude changes were not related to somatic-muscular, respiratory, or heart-rate changes. Women who used oral contraceptives were better able to control vaginal pulse amplitude than women who used other forms of birth control. Although the sexual behavior of these two groups did not differ, women in the latter group tended to be more clitorally oriented.This work was supported in part by NIH grant MH 27098 awarded to C.A.S.