Significant Reduction In Amplitude Research Articles

Changes in the heartbeat-evoked potential are associated with functional seizures

BackgroundPatients with functional seizures (FS) can experience dissociation (depersonalisation) before their seizures. Depersonalisation reflects disembodiment, which may be related to changes in interoceptive processing. The heartbeat-evoked potential (HEP) is an...

Technical characterization of the single-lead electrocardiogram signal from four different smartwatches and its clinical implications

Abstract Funding Acknowledgements Type of funding sources: Public Institution(s). Main funding source(s): Department of Cardiology, University Hospital Basel, University of Basel, Switzerland Institute for Medical Engineering and Medical Informatics, School of Life Sciences, University of Applied Sciences and Arts Northwestern Switzerland, Muttenz, Switzerland Background Smartwatches with the capability of single-lead electrocardiograms (ECGs) acquisition have been established as valuable tool for the detection of atrial fibrillation (AF). For the currently available smartwatches, however, the technical specification of the acquired ECG signal is unclear. Purpose The aim of the current study was to characterize quantitatively the raw signal of the single-lead ECG of four currently available smartwatches (Apple watch series 6, Withings ScanWatch, Samsung Galaxy Watch 4, Fitbit Charge 5) and assess their clinical applicability based on their technical features. Method A bench test was performed applying a synthetic, well-characterized signal to the electrodes of the watches (Figure: (A) Apple watch series 6, (B) Withings ScanWatch, (C) Samsung Galaxy Watch 4, (D) Fitbit Charge 5). The frequency response to this input signal was acquired and Bode plots were calculated (Figure, second column: Bode diagrams show the frequency response (upper) and the phase angles (lower)). To compare the ECG characteristics of the four watches, the synthetical response to a pre-recorded surface ECG dataset was calculated based on the frequency characteristics determined above (Figure, third column: The synthetical raw signal is shown in grey, the response of the watch in blue). Results The frequency responses of all four watches shows a bandpass filter, with an additional 50/60 Hz narrow-band filter (Figure). While the recommended high-pass cut-off at 0.5 Hz was fulfilled by all devices (1), a low-pass cut-off was observed for all devices below 70Hz (instead of 150Hz) resulting in a significantly damped signal. In detail, a damping of -6dB, corresponding to a signal amplitude reduction of 50%, was observed above 70 Hz and below 0.4 Hz for all watches. A QRS complex amplitude reduction was observed for the Apple, Withings and Samsung watch. A pronounced noise filtering is visible for the Samsung and Fitbit Smartwatch. A difference for the clinically relevant characteristic fiducial points, such as the onset of the P-wave or QRS complex, cannot be observed in these examples. However, when using the tangent method to detect the end of the T-wave to calculate the QTc value, a difference between the measures can be observed for the Withings Watch. Conclusion The technical characteristics in terms of filtering characteristics of the single-lead ECG from four commercially available smartwatches differ and must be taken into consideration when attempting to use smartwatches beyond the detection of AF.

Early Impact of Proton Beam Therapy on Electrophysiological Characteristics in a Porcine Model.

Particle therapy is a noninvasive, catheter-free modality for cardiac ablation. We previously demonstrated the efficacy for creating ablation lesions in the porcine heart. Despite several earlier studies, the exact mechanism of early biophysical effects of proton and photon beam delivery on the myocardium remain incompletely resolved. Ten normal and 9 infarcted in situ porcine hearts received proton beam irradiation (40 Gy) delivered to the left ventricular myocardium with follow-up for 8 weeks. High-resolution electroanatomical mapping of the left ventricular was performed at baseline and follow-up. Bipolar voltage amplitude, conduction velocity, and connexin-43 were determined within the irradiated and nonirradiated areas. The irradiated area in normal hearts showed a significant reduction of bipolar voltage amplitude (10.1±4.9 mV versus 5.7±3.2, P<0.0001) and conduction velocity (85±26 versus 55±13 cm/s, P=0.03) beginning at 4 weeks after irradiation. In infarcted myocardium after irradiation, bipolar voltage amplitude of the infarct scar (2.0±2.9 versus 0.8±0.7 mV, P=0.008) was significantly reduced as well as the conduction velocity in the infarcted heart (43.7±15.7 versus 26.3±11.4 cm/s, P=0.02). There were no significant changes in bipolar voltage amplitude and conduction velocity in nonirradiated myocardium. Myocytolysis, capillary hyperplasia, and dilation were seen in the irradiated myocardium 8 weeks after irradiation. Active caspase-3 and reduction of connexin-43 expression began in irradiated myocardium 1 week after irradiation and decreased over 8 weeks. Irradiation of the myocardium with proton beams reduce connexin-43 expression, conduction velocity, and bipolar conducted electrogram amplitude in a large porcine model. The changes in biomarkers preceded electrophysiological changes after proton beam therapy.

Effects of Low-Intensity Aerobic Exercise on Neurophysiological and Behavioral Correlates of Cognitive Function.

Acute aerobic exercise exerts a small beneficial effect on cognition. Previous research primarily examines cognitive changes following a bout of exercise, while little is currently known about changes in cognitive performance during exercise. The primary purpose of this study was to examine the effects of low-intensity cycling on cognitive function indexed by behavioral (response accuracy; reaction time) and neurocognitive (P3 mean amplitude; P3 centroid latency) responses. Twenty-seven (Mage = 22.9 ± 3.0 years old) individuals were counterbalanced into low-intensity exercise (EX) and seated control (SC) conditions spread across two testing sessions. During each condition, participants completed a 10 min resting baseline period, 20 min of either sustained cycling or seated rest, and a 20 min recovery period. Primary outcomes were assessed at 10 min intervals (five blocks total) throughout each condition via a modified visual oddball task while electroencephalography (EEG) responses were measured. Across time blocks, both conditions exhibited faster reaction times on frequent trials but reduced accuracy to rare trials, suggesting a speed-accuracy tradeoff. There were no differences between conditions in P3 centroid latency, whereas a significant reduction in P3 amplitude was observed during the 20 min exercise period compared to the control condition. Taken together, results suggest that exercise at lower doses may have minimal influence on behavioral outcomes of cognitive performance but may impact more basic measures of brain function. Information gathered from this study may aid in the development of appropriate exercise prescriptions for populations looking to specifically target cognitive function deficits.

Peridynamics modeling of cellular elastomeric metamaterials: Application to wave isolation

We investigate how embedded geometrical imperfections can be designed to obtain significant reduction in wave amplitude and large band gap in periodic cellular metamaterials. A finite deformation peridynamics (PD) theory is developed to predict the static and dynamic responses of elastomeric metamaterials. Periodically structured cracks and volumetric geometrical imperfections, e.g., circular and elliptical holes, are embedded in elastomeric materials. Elastic wave propagation through these structured materials is studied by performing numerical simulations using PD. Two main mechanisms are exploited to enhance the energy absorption capacity compared to conventional metamaterials, viz. reflection of wave from crack surfaces and energy absorption due to local elastic instability of the cell walls. Slightly compressible neo-Hookean material model is considered, and plane strain condition is assumed. Nonlinear PD equations for quasi-static condition are solved using the Newton-Raphson method. The present model is validated against finite element solutions considering deformation of a solid elastomeric body subjected to tensile load. The model is also validated with experimental results considering rupture of a double notched elastomeric specimen assuming plane stress condition. PD predictions of nominal stress vs. strain for configurations with holes under quasi-static condition are validated against the experimental observations and numerical simulations through the finite element software ANSYS®. Newmark-beta method is employed to solve the PD equation of motion. At every time step, Newton-Raphson method is used, and convergence is established. The dynamic response obtained from the PD model is validated against finite element solutions using ANSYS® for a solid body. Various novel geometries combining cracks and holes are systematically developed guided by prediction of energy absorption capacity and band gap characteristics through numerical simulations. Wave propagation through these configurations is examined and the effects of microstructure topology on band gap and amplitude reduction are shown. Significant reduction of wave amplitude and large band gap demonstrate remarkable efficacy of the present proposal.

Deep reinforcement learning-based active flow control of vortex-induced vibration of a square cylinder

We mitigate vortex-induced vibrations of a square cylinder at a Reynolds number of 100 using deep reinforcement learning (DRL)-based active flow control (AFC). The proposed method exploits the powerful nonlinear and high-dimensional problem-solving capabilities of DRL, overcoming limitations of linear and model-based control approaches. Three positions of jet actuators including the front, the middle, and the back of the cylinder sides were tested. The DRL agent as a controller is able to optimize the velocity of the jets to minimize drag and lift coefficients and refine the control strategy. The results show that a significant reduction in vibration amplitude of 86%, 79%, and 96% is achieved for the three different positions of the jet actuators, respectively. The DRL-based AFC method is robust under various reduced velocities. This study successfully demonstrates the potential of DRL-based AFC method in mitigating flow-induced instabilities.

Evaluation of gastrocnemius motor evoked potentials induced by trans-spinal magnetic stimulation following tibial nerve crush in rats

Peripheral nerve injuries induce long-lasting physiological and severe functional impairment due to motor, sensory, and autonomic denervation. Preclinical models allow us to study the process of nerve damage, evaluate the capacity of the peripheral nervous system for spontaneous recovery, and test diagnostic tools to assess the damage and subsequent recovery. Methods: In this study on Sprague-Dawley rats, we: 1) compared the use of two different anesthetics (isoflurane and urethane) for the evaluation of motor evoked potentials (MEPs) induced by trans-spinal magnetic stimulation (TSMS) in gastrocnemius and brachioradialis muscles; 2) monitored the evolution of gastrocnemius MEPs by applying paired-pulse stimulation to evaluate the neuromuscular junction activity; and 3) evaluated the MEP amplitude before and after left tibialis nerve crush (up to 7 days post-injury under isoflurane anesthesia). The results showed that muscle MEPs had higher amplitudes under isoflurane anesthesia as compared with urethane anesthesia in the rats, demonstrating higher motoneuronal excitability under isoflurane anesthesia evaluated by TSMS. Following tibial nerve crush, a significant reduction in gastrocnemius MEP amplitude was observed on the injured side, mainly due to axonal damage from the initial crush. No spontaneous recovery of MEP amplitude in gastrocnemius muscles was observed up to 7 days post-crush; even a nerve section did not induce any variation in residual MEP amplitude, suggesting that the initial crush effectively severed axonal fibers. These observations were confirmed histologically by a drastic reduction in the remaining myelinated fibers in the crushed tibial nerve. These data demonstrate that TSMS can be reliably used to noninvasively evaluate peripheral nerve function in rats. This method could therefore readily be applied to evaluate nerve conductance in the clinical environment. This research was funded by the Chancellerie des Universités de Paris (Legs Poix) (SV, MB), the Fondation de France (SV), the Fondation Médisite (SV), INSERM (MB, SV, AM), Université de Versailles Saint-Quentin-en-Yvelines (SV, AM) and Ministry of Science and Technology 109-2636-B-110-001 (KZL). This is the full abstract presented at the American Physiology Summit 2023 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Torsional Vibrations in the Resonance of High-Speed Rotor Bearings Reduced by Dynamic Properties of Carbon Fiber Polymer Composites.

The present study deals with the harmful torsional resonance vibrations of textile rotor bearings, the amplitudes of which are reduced mainly by the use of high-capacity damping materials, characterized by an internal hierarchical structure and macroshape, added into the machine mechanical system. The additional materials are polymer matrix composites reinforced either by carbon nanofibers or carbon chopped microfibers and either aramid or carbon continuous fibers. The macroshape is based on a honeycomb with internal cavities. Torsional vibrations arise in mechanical systems as a result of fluctuations in the low-level pressing load of the flat belt driving the rotor-bearing pin and the changing of kinematic conditions within it, which, in the resonance area, leads to cage slip and unwanted impulsive torsional vibrations. Moreover, this occurs during high-frequency performance at around 2100 Hz, i.e., 126,000 min-1. The condition, before the redesign, was characterized by significantly reduced textile rotor-bearing life due to significant impulse torsional vibrations in the resonance area. The study showed a significant reduction in average and maximum torsional amplitudes in the resonance area by 33% and 43%, respectively. Furthermore, the paper provides visualization of the propagation of a stress wave at the microscale obtained by the explicit finite element method to show the dispersion of the wave and the fibers as one of the sources of high damping.

A Prospective Study of Electromyographic Amplitude Changes During Intraoperative Neural Monitoring for Open Thyroidectomy

BackgroundIntraoperative nerve monitoring (IONM) of the vagus and recurrent laryngeal nerve (RLN) enables prediction of postoperative nerve function. The underlying mechanism for loss of signal (LOS) in a visually intact nerve is poorly understood. The correlation of intraoperative electromyographic amplitude changes (EMG) with surgical manoeuvres could help identify mechanisms of LOS during conventional thyroidectomy.MethodsA prospective study of consecutive patients undergoing thyroidectomy was performed with intermittent IONM using the NIM Vital nerve monitoring system. The ipsilateral vagus and RLN was stimulated, and vagus nerve signal amplitude recorded at five time points during thyroidectomy (baseline, after mobilisation of superior pole, medialisation of the thyroid lobe, before release at Ligament of Berry, end of case). RLN signal amplitude was recorded at two time points; after medialisation of the thyroid lobe (R1), and end of case (R2).ResultsA total of 100 consecutive patients undergoing thyroidectomy were studied with 126 RLN at risk. The overall rate of LOS was 4.0%. Cases without LOS demonstrated a highly significant vagus nerve median percentage amplitude drop at medialisation of the thyroid lobe (− 17.9 ± 53.1%, P < 0.001), and end of case (− 16.0 ± 47.2%, P < 0.001) compared to baseline. RLN had no significant amplitude drop at R2 compared to R1 (P = 0.207).ConclusionsA significant reduction in vagus nerve EMG amplitude at medialisation of the thyroid and the end of case compared to baseline indicates that stretch injury or traction forces during thyroid mobilisation are the most likely mechanism of RLN impairment during conventional thyroidectomy.

Sleep restriction effects on sleep spindles in adolescents and relation of these effects to subsequent daytime sleepiness and cognition.

Limiting spindle activity via sleep restriction could explain some of the negative cognitive effects of sleep loss in adolescents. The current study evaluates how sleep restriction affects sleep spindle number, incidence, amplitude, duration, and wave frequency and tests whether sleep restriction effects on spindles change across the years of adolescence. The study determines whether sleep restriction effects on daytime sleepiness, vigilance, and cognition are related to changes in sleep spindles. In each year of this 3-year longitudinal study, 77 participants, ranging in age from 10 to 16 years, each completed three different time in bed (TIB) schedules: 7, 8.5, or 10 hours in bed for 4 consecutive nights. A computer algorithm detected and analyzed sleep spindles in night four central and frontal electroencephalogram. Objective and self-reported daytime sleepiness and cognition were evaluated on the day following the 4th night. For 7 versus 10 hours TIB average all-night frontal and central spindle counts were reduced by 35% and 32%, respectively. Reducing TIB also significantly decreased spindle incidence in the first 5 hours of non-rapid eye movement sleep, produced small but significant reductions in spindle amplitude, and had little to no effect on spindle duration and spindle wave frequency. Sleep restriction effects did not change with age. The reductions in spindle count and incidence were related to daytime sleepiness on the following day but were not related to working memory. The sleep loss effects on daytime functioning in adolescents are partially mediated by reduced sleep spindles impacting daytime sleepiness.

Seismic amplitude response to internal heterogeneity of mass-transport deposits

Abstract. Compared to unfailed sediments, mass-transport deposits are often characterised by a low-amplitude response in single-channel seismic reflection images. This “acoustic transparency” amplitude signature is widely used to delineate mass-transport deposits and is conventionally interpreted as a lack of coherent internal reflectivity due to a loss of preserved internal structure caused by mass-transport processes. In this study we examine the variation in the single-channel seismic response with changing heterogeneity using synthetic 2-D elastic seismic modelling. We model the internal structure of mass-transport deposits as a two-component random medium, using the lateral correlation length (ax) as a proxy for the degree of internal deformation. The average internal reflectivity is held approximately constant with increasing deformation by fixing the two component sediment lithologies to have realistic P-wave velocity and density based on sediment core measurements from the study area. For a controlled single-source synthetic model a reduction in observed amplitude with reduced ax is consistently observed across a range of vertical correlation lengths (az). For typical autonomous underwater vehicle (AUV) sub-bottom profiler acquisition parameters, in a simulated mass-transport deposit with realistic geostatistical properties, we find that when ax≈1 m, recorded seismic amplitudes are, on average, reduced by ∼25 % relative to unfailed sediments (ax≫103 m). We also observe that deformation significantly larger than core scale (ax&gt;0.1 m) can generate a significant amplitude decrease. These synthetic modelling results should discourage interpretation of the internal structure of mass-transport deposits based on seismic amplitudes alone, as acoustically transparent mass-transport deposits may still preserve coherent, metre-scale internal structure. In addition, the minimum scale of heterogeneity required to produce a significant reduction in seismic amplitudes is likely much larger than the typical diameter of sediment cores, meaning that acoustically transparent mass-transport deposits may still appear well stratified and undeformed at core scale.

Clinical, procedural and lead outcomes associated with different pacing techniques: a network meta-analysis

BackgroundHis- Purkinje system pacing (HPSP) techniques have been proposed as alternative to biventricular pacing (BVP) and right ventricular pacing (RVP). ObjectiveTo compare data regarding clinical, procedural and lead outcomes associated with different pacing techniques. MethodsAn accurate search of online scientific libraries (from inception to May, 12,022) was performed. Thirty-three studies were included in the meta-analysis involving 4386 patients, of whom 1324 receiving RVP, 1032 patients receiving BVP, 1069 patients receiving his-bundle pacing (HBP) and 968 patients receiving left bundle branch pacing (LBBP). ResultsLBBP provided a statistically significant increase in LVEF relative to HBP (0.4473 [0.0584; 0.8361] p = 0.0242) and BVP (0.6733 [0.4734; 0.8732] p < 0.0001) in patients with cardiac resynchronization therapy indication. LBBP and HBP significantly decreased QRS duration as compared to BVP, with largest QRS narrowing obtained by LBBP (−0.4951 [−0.9077; −0.0824] p = 0.0187). As compared to LBBP, HBP was associated with a significant increase of pacing threshold (p = 0.0369) and significant reduction of R-wave amplitude over time (p = 0.027). LBBP was associated with significant reduction in RR of hospitalization for HF (HFH) as compared to both BVP (p = 0.0343) and HBP (p = 0.0476), whereas, as compared to RVP, the risk of lead issues was significantly higher with BVP (p = 0.0424) and HBP (p = 0.0298), but not for LBBP (p = 0.425). ConclusionsAs compared to other pacing techniques, LBBP significantly improved LVEF, narrowed QRS duration and reduced HFHs, with steadily lower capture thresholds and higher R-wave amplitude, and without increasing lead issues.

Evaluating the effects of rifampin in the prevention of neurogenic symptoms and cardiac arrhythmias caused by the systemic toxicity of lidocaine in rats.

Lidocaine toxicity is caused by unintended intravascular injection or overdose. Lidocaine is metabolized in the liver by the CYP3A4 isoenzyme. The objective was to investigate if the administration of rifampin could accelerate animal recovery and reduce the symptoms of lidocaine toxicity by induction of the CYP3A4. Thirty-six male rats were divided into control and treatment groups, each containing three subgroups. The treatment group received oral rifampin suspension daily for 1 week. In all rats, 2.00% lidocaine was injected intravenously. The first subgroup was monitored for neurological symptoms. In the second subgroup, data were recorded after the electrode was placed in the right hippocampus. Electrocardiograms were taken from the third subgroup. CYP3A4 was measured using an ELISA kit. Neurological recovery was seen after 22 and 15 min in the control and treatment groups, respectively. Rifampin also caused a significant reduction in amplitude and number of field action potentials compared to the control group. Numerous cardiac arrhythmias were observed in the control group. The mean level of CYP3A4 in the treatment group was significantly higher than in the control group. In conclusion, oral rifampin could increase the synthesis of CYP3A4, therefore, the animal recovery from lidocaine toxicity was accelerated.

Determination of the Plasma Delay Time in PIPS detectors for fission fragments at the LOHENGRIN spectrometer

The VElocity foR Direct particle Identification spectrometer (VERDI) is a 2E-2v fission spectrometer that allows the measurement of the total mass distribution of secondary fission fragments with a resolving power of 1-2 u. It consists of two time-of-flight (ToF) arms, with one Micro Channel Plate (MCP) detector and up to 32 Silicon PIPS (Passive Implanted Planar Silicon) detectors per arm. The MCPs provide the start timing signals and the PIPS detectors provide both the energy and the stopping ToF signals. In real conditions, the PIPS signals are affected by the formation of plasma from the interaction between the heavy ions and the detector material. The plasma contributes to a reduction in signal amplitude, resulting in a Pulse Height Defect (PHD), and introduces a signal delay, known as Plasma Delay Time (PDT). An experiment to characterize the PDT and PHD was performed at the LOHENGRIN recoil separator of the Institut Laue Langevin (ILL). Characteristic fission fragments from the 239Pu(n,f) reaction were separated based on their A/Q and E/Q ratios, allowing the measurement of a wide range of energies from 21 to 110 MeV and masses between 80 and 149 u. Six PIPS detectors were characterized to study their individual responses to the PDT and PHD effects. The signals were recorded in a digital acquisition system to completely exploit the offline analysis capabilities. Achieved combined timing and energy resolutions for fission fragments varied between 72(2) ps and 100(4) ps and 1.4% - 2% (FWHM), respectively. Preliminary PHD and PDT data are presented from the masses A=85, 95, 130 and 143. The PHD trends are strongly correlated with both the ion energy and mass. The PDT, on the other hand, shows a strong variation as a function of the ion kinetic energy but a smaller dependence on the ion mass.

Weak Seismic Signal Enhancement Using Curvelet Transform and Compressive Sampling

Conventional curvelet-domain denoising methods suppress random noise by thresholding the amplitude of curvelet coefficients, which makes it hard to distinguish weak seismic signals from random noise because they share the same characteristic of weak amplitude in the curvelet domain. Here we put forward an innovative weak seismic signal enhancement method taht can distinguish weak seismic signals from random noise. After compressive sampling, the curvelet coefficients of weak seismic signals show significant amplitude reduction, whereas random noise does not. We take advantage of this characteristic and design a sensitivity coefficient, the absolute ratio of curvelet coefficients before and after compressive sampling. The sensitivity coefficient can distinguish weak seismic signals from random noise in the curvelet domain better than thresholding the amplitude of curvelet coefficients. The results of synthetic and field seismic data applications both indicate that our method outperforms the conventional curvelet-domain denoising method on weak seismic signal enhancement.

Evaluation of Gastrocnemius Motor Evoked Potentials Induced by Trans-Spinal Magnetic Stimulation Following Tibial Nerve Crush in Rats.

Peripheral nerve injuries induce long-lasting physiological and severe functional impairment due to motor, sensory, and autonomic denervation. Preclinical models allow us to study the process of nerve damage, evaluate the capacity of the peripheral nervous system for spontaneous recovery, and test diagnostic tools to assess the damage and subsequent recovery. Methods: In this study on Sprague-Dawley rats, we: (1) compared the use of two different anesthetics (isoflurane and urethane) for the evaluation of motor evoked potentials (MEPs) induced by trans-spinal magnetic stimulation (TSMS) in gastrocnemius and brachioradialis muscles; (2) monitored the evolution of gastrocnemius MEPs by applying paired-pulse stimulation to evaluate the neuromuscular junction activity; and (3) evaluated the MEP amplitude before and after left tibialis nerve crush (up to 7 days post-injury under isoflurane anesthesia). The results showed that muscle MEPs had higher amplitudes under isoflurane anesthesia, as compared with urethane anesthesia in the rats, demonstrating higher motoneuronal excitability under isoflurane anesthesia evaluated by TSMS. Following tibial nerve crush, a significant reduction in gastrocnemius MEP amplitude was observed on the injured side, mainly due to axonal damage from the initial crush. No spontaneous recovery of MEP amplitude in gastrocnemius muscles was observed up to 7 days post-crush; even a nerve section did not induce any variation in residual MEP amplitude, suggesting that the initial crush effectively severed the axonal fibers. These observations were confirmed histologically by a drastic reduction in the remaining myelinated fibers in the crushed tibial nerve. These data demonstrate that TSMS can be reliably used to noninvasively evaluate peripheral nerve function in rats. This method could therefore readily be applied to evaluate nerve conductance in the clinical environment.

Influence of density change on the detection of breast liposarcoma by magneto-acousto-electrical tomography

Magneto-Acousto-Electrical Tomography (MAET) has the advantage of high spatial resolution and high image contrast and is expected to achieve early breast cancer diagnosis. At present, the density of biological tissue is usually assumed to be the density of water. The effect of density changes on the MAET signal has not been studied. Liposarcoma of the breast is a common malignant tumor. Unlike normal breast cancer which occurs in the gland, liposarcoma of the breast occurs in the fat of the breast. However, the fat density of the breast is widely distributed, which is different from that of liposarcoma. Therefore, it is very important to study the effect of density change on the MAET signals. In this paper, a finite element simulation model is established to consider the influence of density variation on the MAET signal. The simulation results show that an increase in density reduces the amplitude of the original MAET signal. The degree of reduction in signal amplitude is proportional to the increase in signal density. The simulation results are consistent with the theoretical analysis. Finally, the MAET experimental platform is built to validate the simulation results of MAET signals. The simulation and experiment results show that the change of density greatly influences the detection of breast liposarcoma based on MAET. It cannot be directly equivalent to the density of water. The results of this study indicate that MAET is expected to detect the early diagnosis of breast liposarcoma.

Centering prayer in the treatment of Parkinson's disease preliminary quality-of-life research

Parkinson's Disease (PD) affects nearly a million Americans, a number that will increase over the coming decades. L-DOPA has been the most effective treatment. While available medical therapies help control symptoms during the initial years following diagnosis, higher doses are required over time, increasing side effects and decreasing control of symptoms. As a result, patients suffering from PD become refractory to conventional treatments. The authors anecdotally observed a significant symptom reduction in a patient who practiced Centering Prayer (CP), taught by Hesse. As a last choice, the experience led the authors to apply teaching CP to four current patients to improve their quality of life. We studied these patients before and after practicing CP, assessing tremors by electromyography records and applying the Unified Parkinson's Disease Rating Scale (UPDRS). A control group of four PD patients with high UPDRS, who were not trained in CP, were also selected. During the active phase of PD symptoms, electromyography (EMG) testing was conducted before and 30 minutes after the CP session in the test group. EMG testing was also done on the control group during the active phase of symptoms, and the groups were compared for a reduction in EMG amplitude. All patients showed a significant reduction in EMG amplitude after the CP session. There were significant UPDRS score decrements at 30 and 45 minutes, lasting up to 60 minutes. These important clinical and EMG results were not found in the control group. With these results, our group plans to collect greater samples of PD patients for proposing CP practice as an alternative treatment for this Disease.

The relationship between round window and ear canal Cochlear microphonic.

Cochlear microphonic recorded at ear canal (CM-EC) can be a substitute for the one recorded at round window (CM-RW). Almost all clinics do not measure tone-burst evoked CM due to technical difficulty although it can provide more information than click evoked CM. Moreover, clinicians like the CM-EC more than that measured at CM-RW because CM-EC is non-invasive. There is difference between CM-RW and CM-EC, for example, CM-EC is less prominent than CM-RW, therefore, studying tone-burst evoked CM-EC and its relationship with CM-RW are highly significant and can promote the clinical application of CM-EC. Nine guinea pigs were randomly allocated into three groups, group 1 was not exposed to noise, called normal control. group 2 and group 3 were exposed to the low- (0.5-2kHz) and high-frequency band-noise (6-8kHz) at 120 dB SPL for 1h, respectively. It was difficulty to record low-frequency CM due to severe environmental interruption, in current study the recording technology of tone-burst evoked CM was optimized so that tone-burst evoked CM was measured across full speech frequency (0.5-8kHz) in the presence of normal hearing and noise induced hearing loss (NIHL). CM-RW and CM-EC were successfully recorded across speech frequency. Significant reduction in CM amplitude was observed at 0.5 and 2kHz in group 2, at 6 and 8kHz in group 3 as compared to group 1, p<.05, indicating that CM amplitude was sensitive to band-noise exposure. Significant correlation between CM-RW and CM-EC was also verified, p<.05. CM-EC is a useful objective test for evaluation of hearing function; the result of current study supports the clinical application of non-invasive CM-EC.

Research on Anti-Scour Effect of Coal Seam Water Injection Based on Electromagnetic and Microseismic Signal Monitoring

ABSTRACT The aim of this study was to examine the accuracy of electromagnetic radiation and microseismic signals in determining the anti-scour effect resulting from coal seam water injection. We established a simultaneous acquisition system of electromagnetic and microseismic full waveforms for coal rock damages under load, and an image acquisition system that captured the entire coal damage process was used. Uniaxial compression experiments of coal samples with different moisture contents were conducted, and the influence of water on the physical and mechanical properties of the coal samples and the generation of electromagnetic and microseismic signals were theoretically analyzed. The results showed that water reduced the adhesion and friction coefficient of particles in the coal body, promoted coal and rock fracture development, and weakened the generation of electromagnetic and microseismic signals. A significant positive correlation was found among stress drop, electromagnetic radiation signals, and microseismic signals, and the temporal distribution of the three variables was synchronous. As moisture content increased, the electromagnetic radiation and microseismic signal amplitude of the coal samples decreased, and the average signal of both signals exhibited an exponential downward trend. The relationship between the mean value of the signal and moisture content was obtained. To evaluate the water-injection effect of the coal samples, we also determined the theoretical percentage of the signal amplitude reduction corresponding to the increment in moisture content required by the on-site coal seam water injection and anti-erosion.