Low-frequency vibration, irrespective of its duration (20 Hz, A = 0.4 mm), is shown to increase GABA level, glutamatedecarboxylase enzyme activity (EC 4.1.1.15) in the large hemispheres, cerebellum, brain stem of adult male rats (12 months). Meanwhile GABA aminotransferase activity (EC 2.6.1.19) remains, mainly, unchanged. The observed shifts are more clear under 30 min vibration than under 7h and 30 day effects. Glutaminic and aspartic acids content increases under 30 min and decreases under 7h and 30 day vibration in the given brain structures.
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Space payloads in orbit are vulnerable to small vibrations from satellite platforms, which can degrade their performance. Traditional methods typically involve installing a passive vibration isolation system between the platform and the payload. However, such systems are usually effective only for high-frequency, large-amplitude vibrations and perform poorly in isolating low-frequency vibrations and resonances below 10 Hz.
View Article and Find Full Text PDFSci Rep
January 2025
Yunnan Phosphating Group Co., Ltd, Kunming, 650600, China.
Due to the fluidity of the loose medium inside the waste dump slope, the traditional monitoring system cannot fully reflect the misalignment and slip between particles inside the medium, and it is also difficult to capture the precursor information of the slip of the loose accumulation body. To reveal the dynamic evolution process of the slope instability of the waste dump slope, the coupling test system of the slope instability of the waste dump slope was used to carry out the study of the acoustic emission characteristics of the slope instability dynamic response of the dump slope under the action of vibration, and to quantitatively analyse the staged characteristics of the acoustic emission parameter evolution of the dump slope under the action of different vibration frequencies and its instability initiation node. The results show that with the increase of vibration frequency, the damage mode of the slope model gradually changes from sliding of small particles to large-scale landslides, and presents the stage process of "vibration compaction → vibration equilibrium → dynamic instability"; Under the action of low-frequency and high-amplitude, the slope model mainly shows that the tiny particles and the basement gravel slip, which is difficult to capture with the naked eye, while under the action of high-frequency and low-amplitude, the slope surface is damaged in a large area, and the overall model is unstable; The dynamic instability of the waste dump slope is accompanied by obvious acoustic emission activities, and the changes of the characteristic parameters of acoustic emission reveal, to a certain extent, the evolution of the internal state of the slope in the process of dynamic instability of the waste dump slope and its stage characteristics; The amplitude and energy efficiency of acoustic emission in the time domain show obvious fractal characteristics in the dynamic instability of the waste dump slope.
View Article and Find Full Text PDFJ Phys Chem Lett
January 2025
School of Engineering and Materials Science, Queen Mary University of London, Mile End Road, London E1 4NS, U.K.
Int Urol Nephrol
December 2024
Department of Nursing, The First Affiliated Hospital of Soochow University, Suzhou, China.
Purpose: Evaluate if low-frequency bladder vibration (LFBV) combined with clean intermittent catheterization (CIC) alleviated urinary tract infections (UTIs) in spinal cord injury (SCI) patients with neurogenic bladder (NB).
Methods: A single-blind randomized controlled trial was conducted. Patients who developed UTIs while rehabilitating from SCI were enrolled continuously between January 2021 and March 2023 and randomly assigned to the control or the intervention group.
Sci Rep
December 2024
Department of Physics, Yunnan University, Kunming, 650500, China.
Vibrational resonance and chaos control in the canonical Chua's circuit with a smooth cubic nonlinear resistor is investigated by an analog circuit experiment and a dynamical model. By adjusting the amplitude and frequency of the high-frequency signal while keeping other parameters constant, the system exhibits a resonant peak in its response to the weak low-frequency signal. Notably, when the amplitude of the high-frequency signal exceeds the critical threshold, the system undergoes a transition from a single-scroll chaotic attractor to a double-scroll chaotic attractor, marking the emergence of vibrational resonance.
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